WO2011010582A1

WO2011010582A1 - Sheet-like structural body, method for manufacturing sheet-like structural body, and surface-emitting body using sheet-like structural body

Info

Publication number: WO2011010582A1
Application number: PCT/JP2010/061877
Authority: WO
Inventors: 恭雄當間; 邦雅檜山
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2009-07-23
Filing date: 2010-07-14
Publication date: 2011-01-27
Also published as: JPWO2011010582A1; JP2015092500A; JP5673535B2

Abstract

Provided is a sheet-like structural body, by which light extraction efficiency of a surface-emitting body is significantly improved. A flexible surface-emitting body having a high light extraction efficiency and improved durability is also provided. The sheet-like structural body is characterized in that a light extraction layer, which has a recessed/protruding structure composed of an aggregate of metal oxide fine particles, is provided on a transparent base material.

Description

Sheet-like structure, method for producing the same, and surface light emitter using the same

The present invention relates to a surface light emitter used for various displays, display devices, illumination, and the like, and a sheet-like structure that improves the light extraction efficiency of the surface light emitter. More specifically, the present invention relates to a sheet-like structure in which a light extraction layer having a concavo-convex structure made of an aggregate of metal oxide fine particles is formed, and a surface light emitter such as an organic electroluminescence element produced using the sheet-like structure.

Surface light emitters used as backlights for various displays, display boards such as signboards and emergency lights, and light sources such as lighting have attracted attention in recent years because they have many excellent features such as high brightness, high efficiency, thinness, and light weight. ing. Among such surface light emitters, organic electroluminescence elements (hereinafter referred to as organic EL elements) that emit light by using electric energy from positive and negative electrodes using an organic material emit light at a low voltage of about several volts to several tens of volts. In particular, the thin film type solid-state device is attracting attention because it saves space.

However, in the case of a surface light emitting device made of a thin film such as an organic EL device, the light emission angle determined by the refractive index of the light emitter thin film layer and the refractive index of the medium through which the emitted light passes is greater than the critical angle. Is totally reflected and confined inside, and lost as guided light. As a result, light emitted from the light emitting layer having no directivity is lost except for the light previously emitted, and the light extraction efficiency (ratio of the energy emitted outside the substrate with respect to the emitted energy) is lowered. There is a problem.

The light extraction efficiency (light emission efficiency) in the forward direction derived from multiple reflection based on classical optics can be approximated by 1 / 2n ² and is almost determined by the refractive index n of the light emitting layer. If the refractive index of the light emitting layer is about 1.7, the light emission efficiency from the organic EL part is simply about 20%. The remaining light propagates in the area direction of the light emitting layer (spray in the lateral direction) or disappears at the metal electrode facing the transparent electrode with the light emitting layer interposed therebetween (absorption in the backward direction). In other words, the organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1), and about 15% to 20% of the light generated in the light emitting layer. Only light can be extracted. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the side surface of the device.

In order to avoid such a phenomenon and improve the light extraction efficiency, there are methods such as a transparent substrate having a concavo-convex structure on the surface, a light diffusion layer containing particles that scatter light in the matrix, and a lens sheet. Proposed.

However, in the method of forming irregularities on the surface of the transparent substrate, as a means for forming irregularities, a method of providing irregularities by etching as in the case of photolithography is common, but the productivity is poor and the cost is increased. In addition, a method of forming an uneven structure imitating a microlens shape on the surface of a glass substrate by a sandblasting method, a frosting method, or the like has also been proposed, but it is difficult to produce an uneven shape with periodicity. It cannot be used for processing into a transparent resin substrate (see Patent Document 1).

In addition, a method of forming a light diffusion layer having a concavo-convex shape on a transparent resin substrate using a roll intaglio or the like, and an organic EL element produced by attaching a film having a concavo-convex shape to the substrate surface have been proposed ( (See Patent Document 1 and Patent Document 2). When a film having such a concavo-convex shape is used, it is generally necessary to use a light diffusing layer together because a sufficient effect cannot be obtained by the film alone. Moreover, it is difficult to periodically form a fine uneven shape of several hundred nm or less.

On the other hand, Patent Document 3 proposes an optical sheet in which inorganic fine particles are added to a lens sheet and a diffusion sheet is unnecessary. Although this improves the light extraction efficiency, it is not yet sufficient, and it has been difficult to produce a fine uneven shape by this method for further efficiency improvement. There are also problems such as fine particles dispersed in the resin damaging the mold, peeling of the adhesive surface between the lens sheet and the substrate, and deterioration of the amount of light due to reflection due to the difference in refractive index at the interface.

On the other hand, Patent Document 4 discloses that transparency is improved by forming a photocatalytic film made of titanium oxide fine particles on the surface of a substrate. This is to apply a film-forming aqueous solution containing titanium oxide fine particles having a peroxo group to the surface of the substrate, and then heat to provide a photocatalytic high-hardness film, and to develop photocatalytic properties by heating. Therefore, the preferable temperature range of the heat treatment is described as 250 to 550 ° C. At this time, there is a possibility that the coating made of titanium oxide fine particles formed on the surface of the substrate has an uneven shape as in the present invention, but Patent Document 4 did not describe the structure. In addition, it has not been known that an uneven shape made of an aggregate of metal oxide fine particles can be used as a light extraction layer.

JP 2008-66027 A JP 2004-45471 A JP 2009-25774 A Japanese Patent Laid-Open No. 2003-210996

In the conventional technology as described above, the light extraction efficiency is still insufficient, and further improvement has been demanded. Particularly for resin substrates, it is difficult to form fine irregularities, and it has been a challenge to achieve both improved light extraction efficiency and flexibility.

The present invention has been made in view of the above problems, and its object is to provide a sheet-like structure that can significantly improve the light extraction efficiency of a surface light emitter, and has high light extraction efficiency and improved durability. Another object of the present invention is to provide a flexible surface light emitter.

As a result of intensive studies on the above problems, the present inventors have used an uneven shape made of an aggregate of metal oxide fine particles as a light extraction layer, and a surface light emission of an organic EL or the like by using a sheet-like structure using the same. It has been found that the light extraction efficiency of the body can be greatly improved.

Although the mechanism of action for improving the light extraction efficiency in the present invention is not clear, it is surprising that the high transmittance by the nano-sized metal oxide fine particles, the effect of light scattering by the aggregate of fine particles, and the light collecting effect by the uneven structure are combined. It is inferred that the effect that should have been demonstrated.

Therefore, the present invention is achieved by the following configuration.

1. A sheet-like structure having a light extraction layer having a concavo-convex structure made of an aggregate of metal oxide fine particles on a transparent substrate.

2. 2. The sheet-like structure according to 1 above, wherein the transparent substrate is a transparent resin film.

3. 3. The sheet-like structure according to 1 or 2, wherein the uneven structure is a periodic uneven structure having an average depth of 5 nm to 300 nm and an average period of 10 nm to 300 nm.

4. 4. The sheet-like structure according to any one of 1 to 3 above, wherein the metal oxide fine particles are amorphous metal oxide fine particles having an average particle diameter of 1 nm to 30 nm.

5. 5. The metal oxide fine particles according to any one of 1 to 4 above, wherein the metal oxide fine particles are oxide fine particles composed of Group 4 or Group 5 elements or composite oxide fine particles composed of Group 4 and Group 5 elements. The sheet-like structure described.

6. 6. In the method for producing a sheet-like structure according to any one of 1 to 5, a step of applying a dispersion liquid containing metal oxide fine particles on at least one surface of a transparent substrate, and a softening point temperature of the substrate or lower A method for producing a sheet-like structure, which is produced by a step of drying with a step of forming a concavo-convex structure comprising an aggregate of the metal oxide fine particles by an external stimulus treatment.

7. 7. The method for producing a sheet-like structure according to 6, wherein the external stimulation process is a process selected from a plasma discharge process, a microwave irradiation process, and an ultraviolet irradiation process.

8. A surface light emitter using the sheet-like structure according to any one of 1 to 5 as a transparent substrate.

9. 6. A surface light emitter comprising the sheet-like structure according to any one of 1 to 5 bonded to a surface on a light emission side.

According to the present invention, it is possible to obtain a sheet-like structure having improved light extraction efficiency and barrier properties that are significantly higher than those of conventional ones. Furthermore, the surface physical property represented by the organic EL element which was improved in the physical properties of the film as well as in flexibility and excellent in durability can be obtained.

FIG. 3 shows a cross-sectional view of a sheet-like structure provided with a light extraction layer having a concavo-convex structure comprising an aggregate of metal oxide fine particles of the present invention. FIG. 1 shows a schematic cross-sectional view of an atmospheric pressure plasma processing apparatus as an example of the external stimulation processing of the present invention. It is the figure which illustrated the electrode structure of the atmospheric pressure plasma processing apparatus.

Hereinafter, the present invention will be described in detail.

The present invention is a sheet-like structure provided with a light extraction layer having a concavo-convex structure composed of an aggregate of metal oxide fine particles, and has the concavo-convex structure on at least one side of a flexible transparent resin film substrate. It is a sheet-like structure provided with a light extraction layer.

<Uneven structure>
The light extraction layer having a concavo-convex structure comprising an aggregate of metal oxide fine particles, which is a feature of the present invention, is a layer having a concavo-convex shape formed by combining a plurality of metal oxide fine particles, and has a light extraction efficiency. It is a layer formed on a transparent substrate for the purpose of improvement.

The concavo-convex structure that is effective as the light extraction layer of the present invention is characterized in that the concavo-convex structure made of an aggregate of metal oxide fine particles as shown in FIG. 1 is continuously formed. The concavo-convex structure used in the present invention is a structure in which the concavo-convex structure is periodically formed by so-called self-organization in which metal oxide fine particles are bonded to each other by an external stimulus. It is different from the uneven shape caused by the thickness.

As shown in FIG. 1, the depth of the concavo-convex structure used in the present invention is a vertical distance from the apex of the convex portion to the lowest point between the adjacent convex portions, and is a transmission electron microscope (TEM). It can be measured by observation with a laser microscope or an atomic force microscope (AFM). The average depth is obtained from the average value of the depths of 300 or more concavo-convex structures. For example, the average value when AFM measurement is performed in a field of view with a side of 80 μm can be used. Moreover, the period of the concavo-convex structure of the present invention is a distance between adjacent convex portions, and can be measured by observation with an electron microscope or a laser microscope. An average period means the average value of the distance between the convex parts in a continuous 50 or more uneven structure.

At this time, it is preferable that each cycle is in the range of 0.5 to 2 times the average cycle, and more preferably in the range of 0.75 to 1.2 times.

The average depth of the concavo-convex structure of the present invention is preferably 1 μm or less, more preferably 5 nm to 500 nm, and particularly preferably 5 nm to 300 nm. The light extraction efficiency is improved by setting the average depth to 5 nm or more, and it is preferable that the average depth is 1 μm or less because the decrease in transmittance is small. The average period of the concavo-convex structure is preferably 1 μm or less, more preferably 5 nm to 500 nm, and particularly preferably 10 nm to 300 nm.

In measuring the average depth and average period of the concavo-convex structure of the present invention, even if it is a method of measuring one location near the center of the sample, select several locations at the periphery and the center of the sample surface, and the measured values The method of taking the average value of

The light extraction layer having a concavo-convex structure made of the metal oxide of the present invention is preferably formed over the entire light emitting surface of the surface light emitter, and at least 50% of the light emitting surface has the concavo-convex structure of the present invention. A take-out layer is preferably formed.

In the present invention, the step of applying a dispersion containing metal oxide fine particles to at least one surface of the substrate, the step of drying at a temperature lower than the softening point temperature of the substrate, and the assembly of the metal oxide fine particles by an external stimulus treatment Manufactured by a process of forming an uneven structure on the body. By external stimulating treatment described later or a combination thereof, the fine particles can be fixed without damaging the base material in a low temperature process.

<Metal oxide fine particles>
The metal oxide fine particles used in the present invention are preferably fine particles of 100 nm or less, more preferably 1 nm or more and 50 nm or less, and particularly preferably 1 nm or more and 30 nm or less. When the average particle diameter is less than 1 nm, particle aggregation proceeds in the dispersion, and thus there is a possibility that a desired uneven shape cannot be obtained. On the other hand, it is preferable to set the average particle size to 100 nm or less because there is little decrease in transparency due to light scattering by the fine particles themselves, and the scattering effect by the aggregate of fine particles is increased. Here, the average particle diameter means an average value of diameters (sphere-converted particle diameters) when 200 or more particles are observed with a scanning electron microscope and each particle is converted into a sphere having the same volume.

As the metal oxide fine particles, the metal constituting the metal oxide is Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Nb, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and a rare earth metal A metal oxide that is one kind or two or more kinds of metals can be used. Specifically, for example, titanium oxide, zinc oxide, aluminum oxide (alumina), zirconium oxide, hafnium oxide, niobium oxide, tantalum oxide, Magnesium oxide, vanadium oxide, indium oxide, tin oxide, lead oxide, and double oxides composed of these oxides, lithium niobate, potassium niobate, lithium tantalate, aluminum Particles and composite particles such as hexafluorophosphate, magnesium oxide (MgAl ₂ O ₄₎ can be mentioned. Among them, oxide fine particles composed of Group 4 or Group 5 elements or composite oxide fine particles composed of Group 4 and Group 5 elements can form a highly rigid uneven shape, so that titanium oxide, zirconium oxide, hafnium oxide, oxidation Vanadium, niobium oxide, and tantalum oxide are preferable, and titanium oxide is particularly preferable.

As the titanium oxide, various oxides and peroxides such as TiO ₂ , TiO ₃ , TiO, and TiO ₃ / nH ₂ O can be used. In particular, titanium peroxide having a peroxo group is preferable. The titanium oxide may be any of amorphous type, anatase type, brookite type, and rutile type, and these may be mixed, but amorphous type titanium oxide is preferred.

As a method for producing the titanium oxide fine particles, a general method for producing titanium dioxide powder can be used.

An example of a preferable method for producing titanium oxide fine particles is shown below. However, in the present invention, the composition of fine particles and the method for producing the fine particles are not limited to this as long as the functions described above are obtained.

<Method for producing titanium oxide fine particles>
First, a titanium hydroxide is formed by reacting a tetravalent titanium compound such as titanium tetrachloride with a base such as ammonia. Next, this titanium hydroxide is peroxo-oxidized with an oxidizing agent to form ultrafine particles of amorphous titanium peroxide. This reaction is preferably carried out in an aqueous medium. Furthermore, it is also possible to transfer to anatase-type titanium peroxide by arbitrary heat treatment.

The peroxidation oxidizing agent is not particularly limited, and various types can be used as long as they can form a titanium peroxo compound, that is, titanium peroxide, but hydrogen peroxide is preferable. When hydrogen peroxide is used as the oxidizing agent, the concentration of hydrogen peroxide is not particularly limited, but is preferably 30 to 40%. It is preferred to cool the titanium hydroxide before peroxolation. The cooling temperature at that time is preferably 1 to 5 ° C.

The titanium hydroxide thus obtained is washed with pure water, cooled to around 5 ° C., and then peroxoated with hydrogen peroxide. Thereby, the aqueous dispersion containing the titanium oxide fine particle which has an amorphous peroxo group can be manufactured.

As the above-mentioned tetravalent titanium compound, various titanium compounds can be used as long as they can form titanium hydroxide also called orthotitanic acid (H ₄ TiO ₄ ) when reacted with a base. There are water-soluble inorganic acid salts of titanium such as titanium tetrachloride, titanium sulfate, titanium nitrate, and titanium phosphate. In addition, water-soluble organic acid salts of titanium such as titanium oxalate can be used. Of these various titanium compounds, titanium tetrachloride is preferred because it is particularly excellent in water solubility and no components other than titanium remain in the titanium oxide dispersion.

Further, when a tetravalent titanium compound solution is used, the concentration of the solution is not particularly limited as long as a titanium hydroxide gel can be formed, but a relatively dilute solution is preferable. Specifically, the solution concentration of the tetravalent titanium compound is preferably 5 to 0.01% by mass, and more preferably 0.9 to 0.3% by mass.

As the base to be reacted with the tetravalent titanium compound, various bases can be used as long as they can react with the tetravalent titanium compound to form titanium hydroxide, and include ammonia, caustic soda, sodium carbonate, Although caustic potash and the like can be exemplified, ammonia is most preferable.

In addition, when the above base solution is used, the concentration of the solution is not particularly limited as long as a titanium hydroxide gel can be formed, but a relatively dilute solution is preferable. Specifically, the concentration of the base solution is preferably 10 to 0.01% by mass, and more preferably 1.0 to 0.1% by mass. In particular, when ammonia water is used as the base solution, the ammonia concentration is preferably 10 to 0.01% by mass, more preferably 1.0 to 0.1% by mass.

Further, as a different production method, a method using a sol-gel method can be mentioned. This is a mixture of titanium alkoxide with a solvent such as water and alcohol, an acid or base catalyst, and the titanium alkoxide is hydrolyzed to produce a sol solution of ultrafine titanium oxide. Either before or after the hydrolysis, at least one of copper, manganese, nickel, cobalt, iron, zinc, or a compound thereof may be mixed. The titanium oxide thus obtained is an amorphous type having a peroxo group.

As the titanium alkoxide, a compound represented by the general formula: Ti (OR ′) ₄ (where R ′ is an alkyl group), or one or two alkoxide groups (OR ′) in the general formula is a carboxyl group. Alternatively, a compound substituted with a β-dicarbonyl group or a mixture thereof is preferable.

Specific examples of the titanium alkoxide include Ti (O—iso—C ₃ H ₇ ) ₄ , Ti (On—C ₄ H ₉ ) ₄ , Ti (O—CH ₂ CH (C ₂ H ₅ ) C _4. H ₉ ) ₄ , Ti (O—C ₁₇ H ₃₅ ) ₄ , Ti (O—iso—C ₃ H ₇ ) ₂ [CO (CH ₃ ) CHCOCH ₃ ] ₂ , Ti (On—C ₄ H ₉ ) ₂ [OC ₂ H ₄ N (C ₂ H ₄ OH) ₂ ] ₂ , Ti (OH) ₂ [OCH (CH ₃ ) COOH] ₂ , Ti (OCH ₂ CH (C ₂ H ₅ ) CH (OH) C ₃ H ₇ ) ₄ , Ti (On-C ₄ H ₉ ) ₂ (OCOC ₁₇ H ₃₅ ) and the like.

Examples of the compound of copper, manganese, nickel, cobalt, iron or zinc described above include Ni compound: Ni (OH) ₂ , NiCl ₂ , Co compound: Co (OH) NO ₃ , Co (OH) ₂ , CoSO ₄ , CoCl ₂ , Cu compound: Cu (OH) ₂ , Cu (NO ₃ ) ₂ , CuSO ₄ , CuCl ₂ , Cu (CH ₃ COO) ₂ , Mn compound: MnNO ₃ , MnSO ₄ , MnCl ₂ , Fe compound: Fe ( _{_{OH) 2, Fe (OH)}} 3, FeCl 3, Zn _{_{_{compounds: Zn (NO 3) 2,}}} ZnSO 4, and the like ZnCl _2.

The blending amount of copper, manganese, nickel, cobalt, iron, and zinc is preferably 1: 0.01 to 1: 0.5 in terms of the stability of the aqueous dispersion in terms of the molar ratio of titanium to the metal component. A ratio of 1: 0.03 to 1: 0.1 is more preferable.

In the present invention, it is preferable to prepare a dispersion in which the prepared metal oxide fine particles are dispersed in the presence of a surfactant or a dispersant, and form a film on a substrate in a coating process.

Examples of the coating means include known coating methods such as spray coating, dip coating, flow coating, spin coating, and die coating, and screen printing, roll screen printing, offset printing, flexographic printing, gravure printing, inkjet printing, and the like. It can also be applied using any printing method.

It is a feature of the present invention that after the coating film formation, the drying treatment is performed below the softening point of the base material so as not to damage the base material.

The thickness of the coating film is preferably 0.01 to 100 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.5 to 10 μm in terms of dry film thickness.

As the surfactant or dispersant, various organosilicon compounds can be used. As the organosilicon compound, various silane compounds and various silicone oils, silicone rubbers and silicone resins can be used, but those having an alkyl silicate structure or a polyether structure in the molecule, or having an alkyl silicate structure and a polyether structure. It is desirable to have both.

Here, the alkyl silicate structure refers to a structure in which an alkyl group is bonded to a silicon atom of a siloxane skeleton. On the other hand, the polyether structure is not limited to these, but specifically, polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide block copolymer, polyethylene polytetramethylene glycol. Examples thereof include molecular structures such as a copolymer and a polytetramethylene glycol-polypropylene oxide copolymer. Among them, the polyethylene oxide-polypropylene oxide block copolymer is more preferable from the viewpoint of controlling the wettability depending on the block degree and molecular weight.

An organic substance having both an alkyl silicate structure and a polyether structure in the molecule is particularly preferred. Specifically, polyether-modified silicone such as polyether-modified polydimethylsiloxane is suitable. This can be produced by a known method, for example, by the synthesis examples 1, 2, 3, 4 described in JP-A-4-242499, the method described in the reference example of JP-A-9-165318, etc. Can be manufactured. In particular, polyethylene oxide-polypropylene oxide block copolymer-modified polydimethylsiloxane obtained by reacting methallyl polyethylene oxide-polypropylene oxide block copolymer with dihydropolydimethylsiloxane is preferred.

Specifically, TSF4445, TSF4446 (manufactured by GE Toshiba Silicone Co., Ltd.), SH200 (manufactured by Toray Dow Corning Silicone Co., Ltd.), KP series (manufactured by Shin-Etsu Chemical Co., Ltd.), and DC3PA, ST869A, SH3746, SH3746M (Toray Dow Corning Silicone Co., Ltd.) can be used. Although these are additives for paints, they can be used as appropriate as long as they can provide these performances other than for paints.

<Transparent substrate>
The transparent substrate used in the sheet-like structure of the present invention is not particularly limited as long as it has high light transmittance. For example, a glass substrate, a resin substrate, a resin film, etc. are preferably mentioned in terms of excellent hardness as a base material and ease of film formation on the surface, but from the viewpoint of lightness and flexibility It is preferable to use a transparent resin film.

The transparent resin film that can be preferably used as the transparent substrate in the present invention is not particularly limited, and the material, shape, structure, thickness and the like can be appropriately selected from known ones. For example, polyolefins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyester resin film such as modified polyester, polyethylene (PE) resin film, polypropylene (PP) resin film, polystyrene resin film, cyclic olefin resin, etc. Resin films, vinyl resin films such as polyvinyl chloride and polyvinylidene chloride, polyether ether ketone (PEEK) resin films, polysulfone (PSF) resin films, polyether sulfone (PES) resin films, polycarbonate (PC) resin films , Polyamide resin film, polyimide resin film, acrylic resin film, triacetyl cellulose (TAC) resin film, and the like. If the resin film transmittance of 80% or more at 0 ~ 780 nm), can be preferably applied to a transparent resin film according to the present invention. Among these, from the viewpoint of transparency, heat resistance, ease of handling, strength and cost, it is preferably a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyethylene naphthalate film, a polyethersulfone film, or a polycarbonate film, and biaxially stretched. More preferred are polyethylene terephthalate films and biaxially stretched polyethylene naphthalate films.

In the present invention, the refractive index of the transparent resin film is preferably 1.50 or more, more preferably 1.60 or more and 1.80 or less. In the present invention, the refractive index of the concavo-convex structure by the metal oxide fine particles and the refractive index difference of the transparent resin film are preferably small, the refractive index difference is preferably 0.2 or less, and further 0.1 or less. Preferably there is.

In the present invention, the thickness of the transparent resin film is preferably from 50 μm to 250 μm, and more preferably from 75 μm to 200 μm.

The transparent substrate used in the present invention can be subjected to a surface treatment or an easy adhesion layer in order to ensure the wettability and adhesion of the coating solution. A conventionally well-known technique can be used about a surface treatment or an easily bonding layer. For example, the surface treatment includes surface activation treatment such as corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment.

Also, examples of the easy adhesion layer include polyester, polyamide, polyurethane, vinyl copolymer, butadiene copolymer, acrylic copolymer, vinylidene copolymer, epoxy copolymer and the like. The easy adhesion layer may be a single layer, but may be composed of two or more layers in order to improve adhesion. The resin film may contain a filler for the purpose of imparting a light scattering function, and the particle size of the filler is preferably about 0.5 to 10 μm. In addition, a barrier coat layer or a hard coat layer may be formed in advance on both surfaces or one surface of the transparent substrate.

When a barrier coat layer or a hard coat layer is provided, if the refractive index with the transparent substrate is large, the light extraction due to the interface reflection is deteriorated. Therefore, the refractive index of the barrier coat layer and the hard coat layer is the refractive index of the transparent resin film. The rate is preferably the same or slightly lower than the rate. For example, a resin containing fine particles having an average particle diameter of 1 nm or more and 400 nm or less may be used as the hard coat layer. Fine particles having a refractive index higher than that of the resin in the transparent resin have an average particle diameter of 1 to 400 nm. By dispersing, a transparent hard coat layer having a desired refractive index can be obtained.

(External stimulus processing)
As the external stimulation treatment that can be used in the present invention, any external stimulation treatment can be used as long as it is a method of forming an aggregate of metal oxide fine particles in a concavo-convex structure. In the present invention, a flexible substrate is used. It is necessary to prevent damage.

Further, it is preferable to use a method capable of locally applying energy to the light extraction layer made of fine particles formed on the substrate.

Examples of the external stimulation treatment method that can be used in the present invention include plasma discharge treatment, microwave irradiation treatment, ultraviolet irradiation treatment, electromagnetic wave irradiation treatment, pressure treatment, and heat treatment. Plasma discharge treatment, microwave irradiation treatment, and ultraviolet irradiation treatment, and more specifically, oxygen plasma treatment, microwave irradiation treatment, ultraviolet irradiation ozone treatment, or a combination of these treatments is preferably performed.

[Plasma discharge treatment]
A plasma processing apparatus that can be preferably used in the practice of the present invention will be described below, but the present invention is not limited to this. In the present invention, as the plasma processing, flame plasma processing, corona discharge processing, atmospheric pressure plasma processing, and the like are targeted. Hereinafter, atmospheric pressure plasma processing will be described as a representative of plasma processing.

The plasma treatment step according to the present invention is preferably an atmospheric pressure plasma treatment performed at or near atmospheric pressure from the viewpoint of productivity because the subsequent coating step can be performed quickly. The specific pressure is preferably from 70 kPa to 130 kPa, and most preferably atmospheric pressure without any pressure reduction or pressurization.

In order to generate plasma, it is necessary to discharge in an atmosphere of an inert gas as a carrier gas. Here, the inert gas refers to a group 18 element of the periodic table, so-called rare gas, helium, neon , Argon, krypton, xenon, radon or the like, and more preferably in a nitrogen gas atmosphere, and argon or helium is particularly preferably used. However, it is most preferable to use nitrogen gas from the viewpoint of manufacturing cost.

As a preferred embodiment of the present invention, it is preferable to contain 0.01% to 30% (volume ratio) of a reactive gas together with an inert gas, more preferably 0.1% to 20%, and most preferably 1% to It is more preferable in the practice of the present invention to contain 15% reactive gas.

A plurality of reactive gases used in the present invention can be used, but at least one of them is preferably in a plasma state in the discharge space and containing a component capable of treating the surface of the object.

As preferable examples of the reactive gas, a gas such as oxygen, carbon dioxide, nitrogen (except in the case of a nitrogen atmosphere), hydrogen, or the like may be included. Moreover, in order to positively modify the surface, it is also a preferred embodiment in the present invention to use methane, ammonia, various organometallic compounds, fluorine compounds, or the like as the reactive gas.

In the present invention, oxygen plasma treatment using oxygen gas in combination with the above-described reactive gas is most preferable from the viewpoint of reactivity. Furthermore, by using together with the amorphous metal oxide fine particles of the present invention, adhesion between particles is promoted, which is more preferable.

When plasma treatment is performed under atmospheric pressure, the starting voltage increases. To suppress this, a dielectric is sandwiched between the discharge electrode surfaces, the atmospheric gas is helium, argon, or nitrogen, and AC or high frequency is used as a power source. It is preferable to use it.

The frequency is preferably 1 kHz to 1 GHz. Power to be applied, the composition of the sample of interest, also depends surface properties such as, it is necessary to optimize the conditions, 0.1 seconds number ~ with power in the range of 0.01 ~ 10 W / cm ² Discharge treatment is performed in the range of 10 seconds. If the applied power is too high, the smoothness of the surface may be impaired and problems such as contamination of scattered substances due to discharge may occur.

An example of an atmospheric pressure plasma processing apparatus that can be used in the present invention will be described with reference to FIG.

FIG. 2 shows an example of a so-called roll-to-roll plasma processing apparatus that can be applied to a flexible film substrate transport process. In FIG. 2, the atmospheric pressure plasma processing apparatus 30 is an apparatus having an electric field applying means 40 having two power sources, a gas supplying means 50, and an electrode temperature adjusting means 60.

Organometallic compound gas and / or oxygen supplied from the gas supply means 50 between the opposing electrodes (discharge space) 32 between the roll electrode (first electrode) 35 and the plurality of rectangular tube electrodes (second electrodes) 36. A mixture G of gas and a discharge gas such as nitrogen is supplied, activated here and introduced onto the substrate F.

A discharge space (between the counter electrodes) 32 between the roll rotating electrode (first electrode) 35 and the square tube electrode (second electrode) 36 is connected to the roll rotating electrode (first electrode) 35 from the first power source 41. The first high-frequency electric field having the frequency ω1, the electric field strength V1, and the current I1 is supplied to the square tube electrode (second electrode) 36, and the second high-frequency electric field having the frequency ω2, the electric field strength V2, and the current I2 is supplied from the second power source 42. It comes to apply.

A first filter 43 is installed between the roll rotation electrode (first electrode) 35 and the first power supply 41, and the first filter 43 easily passes a current from the first power supply 41 to the first electrode. The current from the second power supply 42 is grounded so that the current from the second power supply 42 to the first power supply is difficult to pass. Further, a second filter 44 is provided between the square tube electrode (second electrode) 36 and the second power source 42, and the second filter 44 is a current from the second power source 42 to the second electrode. It is designed to make it difficult to pass the current from the first power supply 41 to the second power supply by grounding the current from the first power supply 41.

In the present invention, the roll rotating electrode 35 may be the second electrode, and the square tube electrode 36 may be the first electrode. In any case, the first power source is connected to the first electrode, and the second power source is connected to the second electrode. The first power source preferably applies a higher high-frequency electric field strength (V1> V2) than the second power source. Further, the frequency has the ability to satisfy ω1 <ω2.

The current is preferably I1 <I2. The current I1 of the first high-frequency electric field is preferably 0.3 to 20 mA / cm ² , more preferably 1.0 to 20 mA / cm ² . The current I2 of the second high frequency electric field is preferably 10 to 100 mA / cm ² , more preferably 20 to 100 mA / cm ² .

In the gas supply means 50, the reactive gas G generated by the gas generator 51 is introduced into the atmospheric pressure plasma processing vessel 31 from the air supply port 52 while controlling the flow rate.

The base material F is unwound from the original winding (not shown) and conveyed, or is conveyed from the previous process, and the air entrained by the base material by the nip roll 65 via the guide roll 64 is blocked. While being in contact with the roll rotation electrode 35, it is transferred between the roll tube electrode 36 and the square tube electrode 36, and an electric field is generated from both the roll rotation electrode (first electrode) 35 and the square tube electrode (second electrode) 36. Then, discharge plasma is generated between the counter electrodes (discharge space) 32. The substrate F is treated with a plasma state gas while being wound while being in contact with the roll rotating electrode 35. The base material F is transferred to the next process through the nip roll 66 and the guide roll 67.

The treated exhaust G ′ after the discharge treatment is discharged from the exhaust port 53.

In order to heat or cool the roll rotating electrode (first electrode) 35 and the rectangular tube electrode (second electrode) 36, the medium whose temperature is adjusted by the electrode temperature adjusting means 60 is passed through the pipe 61 by the liquid feed pump P. Send to both electrodes and adjust the temperature from inside the electrodes.

In addition, 68 and 69 are partition plates which partition the atmospheric pressure plasma processing vessel 31 and the outside world.

Each square tube electrode 36 shown in FIG. 2 has an effect of widening the discharge range (discharge area) as compared with the cylindrical electrode, and thus is preferably used in the present invention. Further, as shown in FIG. 3, it is preferable to cover the surface of the metal base 36A with a dielectric 36B to form a rectangular tube electrode 36a for discharging at atmospheric pressure.

The distance between the opposing first electrode and second electrode is the shortest distance between the surface of the dielectric and the surface of the conductive metal base of the other electrode when a dielectric is provided on one of the electrodes. In other words, when a dielectric is provided on both electrodes, it means the shortest distance between the dielectric surfaces.

The distance between the electrodes is determined in consideration of the thickness of the dielectric provided on the conductive metal matrix, the magnitude of the applied electric field strength, the purpose of using plasma, etc., but in any case, uniform discharge is performed. From the viewpoint, it is preferably 0.1 to 20 mm, particularly preferably 0.5 to 2 mm.

The atmospheric pressure plasma processing container 31 is preferably a processing container made of Pyrex (registered trademark) glass or the like, but may be made of metal as long as it can be insulated from the electrodes. For example, polyimide resin or the like may be attached to the inner surface of an aluminum or stainless steel frame, and the metal frame may be thermally sprayed to obtain insulation.

Hereinafter, a high-frequency power source applicable to the atmospheric pressure plasma processing apparatus according to the present invention will be exemplified.

As the first power source (high frequency power source) installed in the atmospheric pressure plasma discharge processing apparatus of the present invention,
Manufacturer Frequency Product name Shinko Electric 3kHz SPG3-4500
SHINKO ELECTRIC 5kHz SPG5-4500
Kasuga Electric 15kHz AGI-023
Shinko Electric 50kHz SPG50-4500
HEIDEN Research Laboratories 100kHz * PHF-6k
Pearl Industry 200kHz CF-2000-200k
Pearl Industry 400kHz CF-2000-400k
And the like, and any of them can be used.

As the second power source (high frequency power source),
Manufacturer Frequency Product name Pearl Industry 800kHz CF-2000-800k
Pearl Industry 2MHz CF-2000-2M
Pearl Industry 13.56MHz CF-5000-13M
Pearl Industry 27MHz CF-2000-27M
Pearl Industry 150MHz CF-2000-150M
And the like, and any of them can be preferably used.

Of the above power sources, * indicates a HEIDEN Laboratory impulse high-frequency power source (100 kHz in continuous mode).

Other than that, it is a high frequency power supply that can apply only continuous sine wave.

In the present invention, it is preferable to employ an electrode capable of maintaining a uniform and stable discharge state by applying such an electric field in an atmospheric pressure plasma processing apparatus.

In the present invention, the power applied between the electrodes facing each other is such that power (power density) of 1 W / cm ² or more is supplied to the second electrode (second high-frequency electric field) to excite the discharge gas to generate plasma. The target sample surface is processed.

The upper limit value of the power supplied to the second electrode is preferably 50 W / cm ² , more preferably 20 W / cm ² . The lower limit is preferably 1.2 W / cm ² . In addition, discharge area (cm < ² >) points out the area of the range which discharge occurs in an electrode.

Further, by supplying power (output density) of 1 W / cm ² or more to the first electrode (first high frequency electric field), the output density is improved while maintaining the uniformity of the second high frequency electric field. be able to. More preferably, it is 5 W / cm ² or more. Moreover, the upper limit value of the power supplied to the first electrode is preferably 50 W / cm ² .

This makes it possible to generate further uniform and high-density plasma, and to improve both the processing speed and the processing performance.

Here, the waveform of the high-frequency electric field is not particularly limited. There are a continuous sine wave continuous oscillation mode called a continuous mode, an intermittent oscillation mode called ON / OFF intermittently called a pulse mode, and either of them may be adopted, but at least the second electrode side (second The high frequency electric field is more preferably a continuous sine wave.

2 is an apparatus having an electrode temperature adjusting means 60. The atmospheric pressure plasma processing apparatus shown in FIG.

The plasma discharge treatment according to the present invention is preferably performed at a temperature as high as possible from the viewpoint of reactivity, but in the present invention, the treatment is performed below the softening point of the base material so as not to damage the base material. The temperature range of the roll rotating electrode (first electrode) is preferably 50 ° C. or higher and 100 ° C. or lower.

The plasma irradiation time can be controlled by the conveyance speed of the substrate F, and is appropriately adjusted according to the irradiation time. A preferable irradiation time is 0.1 to 100 seconds, more preferably 0.2 to 30 seconds, and most preferably 0.5 to 20 seconds. Although the effect of the present invention is easily exhibited as the irradiation is continued for a long time, it is preferable to process in a shorter time in consideration of productivity.

<Microwave irradiation treatment>
As a preferable microwave processing used in the present invention, it is preferable to use a microwave having a frequency of 0.3 GHz to 50 GHz, and 0.8 GHz and 1.5 GHz band, 2 GHz band, amateur radio, aircraft used in mobile communication. The 1.2 GHz band used for radar, 2.4 GHz band used for microwave ovens, local radio, VICS, 3 GHz band used for ship radar, etc., and 5.6 GHz used for other ETC communications are all electromagnetic waves. An electromagnetic wave or the like that falls within the category is preferable, but a microwave (frequency of 0.3 GHz to 50 GHz) is more preferable.

The most commonly used microwave is 2.45 GHz among the above-mentioned microwaves, and can be processed by using, for example, a microwave reactor manufactured by Shikoku Keiki Kogyo.

In the present invention, a substance having electromagnetic wave absorption ability is combined with the metal oxide fine particles described above, and the substance selectively absorbs microwaves, whereby a local heat treatment can be performed. This is a preferred embodiment in the invention.

The power of the microwave irradiation treatment is preferably 300 W to 800 W, more preferably 400 W to 600 W. The irradiation time can be arbitrarily selected depending on the reactivity, but preferably it can be processed within 10 minutes, more preferably within 2 minutes. Moreover, in order to reduce the damage to a base material, you may perform a microwave irradiation intermittently, In that case, it is preferable to process by the total irradiation time which has irradiated.

The substance having the ability to absorb electromagnetic waves (substance that absorbs electromagnetic waves) is more preferably fine particles having a sufficiently small particle diameter that does not cause light scattering, like the metal oxide fine particles described above. From the viewpoint of suppressing light scattering typified by Mie scattering, fine particles having an average diameter of 1 to 100 nm are preferable, and diameters of 1 nm to 50 nm are more preferable.

The above-mentioned substance having electromagnetic wave absorbing ability absorbs the irradiated electromagnetic wave and converts it into heat, so that the substance itself generates heat and becomes a heat source, so that dielectric loss or resistance loss is taken so as not to damage the substrate. It is preferable to use a material that is large and efficiently generates heat and can be locally heated.

As the material having electromagnetic wave absorbing ability, metal oxide or metal is preferable.

The metal oxide is preferably an oxide of copper, nickel, zinc, tin, or indium. In the case where a metal oxide is oxidized by irradiation with electromagnetic waves in the presence of oxygen, a metal salt, halide, or organometallic compound containing a metal atom can also be used. Metals of metal salts, metal oxides, organometallic compounds, halogen metal compounds, metal hydrides include Li, Be, B, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn Fe, Co, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y, Zr, Nb, Mo, Cd, In, Ir, Sn, Sb, Cs, Ba, La, Hf, Ta, W, Tl , Pb, Bi, Ce, Pr, Nd, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and the like. Among them, it is preferable to contain any of copper, nickel, Zn (zinc), Sn (tin), and In (indium), and they may be used in combination.

Examples of the metal having electromagnetic wave absorbing ability that can be preferably used in the present invention include platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, iridium, Aluminum, ruthenium, germanium, molybdenum, tungsten, tin oxide / antimony, indium tin oxide (ITO), fluorine doped zinc oxide, zinc, carbon, graphite, glassy carbon, silver paste and carbon paste, lithium, beryllium, sodium, magnesium , Potassium, calcium, scandium, titanium, manganese, zirconium, gallium, niobium, sodium, sodium-potassium alloy, magnesium, lithium, aluminum, magnesium / copper mixture, magnesium / Mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, can be used lithium / aluminum mixtures.

<Ultraviolet irradiation treatment>
Examples of the external stimulus treatment that can be preferably used in the present invention include an ultraviolet irradiation treatment. The ultraviolet irradiation method may be any device such as a high-pressure mercury lamp, a xenon lamp, a deuterium lamp, or an LED lamp, but preferably a device capable of irradiating light with a wavelength of ultraviolet light of about 150 to 400 nm is used. An apparatus capable of irradiating ultraviolet light of 185 to 365 nm is more preferable.

By treating in an atmosphere where oxygen is present simultaneously with ultraviolet light irradiation, ozone generated by ultraviolet light has an effect of promoting adhesion between peroxidized active fine particles, which is a more preferable embodiment. The preferable oxygen concentration is 18 to 50%, more preferably 20 to 30%.

In the irradiation treatment described above, the treatment is performed by exposing to ozone together with ultraviolet light irradiation. The treatment time is preferably 1 to 30 minutes, more preferably about 2 to 15 minutes.

<Heat treatment>
As the heat treatment, a method using an oven or a hot plate can be raised, but since a treatment at a temperature that does not deteriorate the resin base material is required, the heating temperature is preferably 110 ° C. or higher and 200 ° C. or lower. Furthermore, 110 degreeC or more and 150 degrees C or less are preferable. In addition, in the present invention, in order to form an uneven structure by an aggregate of metal oxide fine particles by heat treatment at a temperature that does not deteriorate the resin base material, a compound that promotes adhesion between the metal oxide fine particles should be used. preferable.

As a compound that promotes adhesion between metal oxide fine particles by heating, for example, a urea compound represented by the general formula [I] can be preferably used.

In the general formula [I], R ₁ and R ₆ are an alkyl group, an alkenyl group, an aryl group, a group having a polyoxyalkylene chain, and a group having a polyester chain, and R ₃ and R ₄ are a hydrogen atom or an alkyl group, respectively. Represents a group. R ₂ and R ₅ represent an alkylene group, an alkenylene group, an arylene group, a divalent group having a polyester chain, or a divalent group having a polyoxyalkylene chain, and n represents an integer of 1 or more. At least one of R ₂ and R ₅ is a divalent group having a poly (oxyalkylene) chain. When at least one of R ₂ and R ₅ has a poly (oxyalkylene) chain, either R ₁ or R ₆ is preferably a group having a polyoxyalkylene chain. One of R ₂ and R ₅ may be a simple bond.

The alkyl group or alkenyl group represented by R ₁ or R ₆ is preferably an alkyl group or alkenyl group having 1 to 30 carbon atoms, preferably an alkyl group or alkenyl group having 18 or less carbon atoms, more preferably. Is an alkyl group or alkenyl group having 8 or less carbon atoms. Also preferred as the aryl group is a phenyl group.

These groups may also be optionally substituted.

The typical substituent is not particularly limited, and may be an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, hexyl group, decyl group, dodecyl group, etc.), cycloalkyl group (for example, cyclohexane). Propyl group, cyclopentyl group, cyclohexyl group etc.), alkenyl group (eg vinyl group, 1-propenyl group, butenyl group, allyl group etc.), aryl group (eg phenyl group, naphthyl group etc.), heterocyclic group (eg , Furyl group, thienyl group, etc.), halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, hydroxyl group, carboxyl group, alkoxy group (for example, alkoxy formed by combining the aforementioned alkyl group and oxygen atom) Group), an aryloxy group (the aryl group has the same meaning as the above-mentioned aryl group) A heterocyclic oxy group (the heterocyclic ring is as defined above for the heterocyclic group), an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group (the alkoxy moiety is as defined above for the alkoxy group), aryloxycarbonyloxy Groups (the aryl moiety is as defined above for the aryl group), amino groups, alkyl and arylamino groups (the alkyl moiety and the aryl moiety are as defined above for the alkyl group and aryl group, respectively), anilino group, and acylamino group , Aminocarbonylamino group, alkoxycarbonylamino group (alkoxy moiety is as defined above for alkoxy group), aryloxycarbonylamino group (aryl moiety is as defined for aryl group as described above), sulfamoylamino group, alkyl And Ally Sulfonylamino group (the alkyl moiety and aryl moiety are as defined above for alkyl group and aryl group, respectively), sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group (alkyl moiety, aryl moiety) Are as defined above for the alkyl group and aryl group), acyl group, aryloxycarbonyl group (wherein the aryl moiety is as defined above for the aryl group), and alkoxycarbonyl group (where the alkoxy moiety is as described above). Synonymous with alkoxy group), carbamoyl group, imide group, ureido group, boronic acid group, phosphato group, sulfato group, and other known substituents.

Examples of the substituent include a carboxyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, and the like.

Moreover, a plurality of these substituents may be substituted.

Examples of the group represented by R ₁ or R ₆ and having a poly (oxyalkylene) chain include:
-(R "O) _m -R '
Wherein R ″ is an alkylene group having 2 to 4 carbon atoms, preferably a group such as ethylene or propylene. R ′ is a hydrogen atom or a group having 1 to 30 carbon atoms. An alkyl group, an alkenyl group, an aryl group having 10 or less carbon atoms, an acyl group having 22 or less carbon atoms, such as an acetyl group or a propionyl group, and a benzoyl group, etc. m represents 1. Represents an integer of ˜16, preferably 3˜10.

The alkyl group, alkenyl group, aryl group and acyl group represented by R ′ may each have a substituent, and examples of the substituent include the above-described substituents. A plurality of these may be substituted. In particular, preferred examples of the substituent include a carboxyl group, an aryloxycarbonyl group, and an alkoxycarbonyl group.

The group having a polyester chain represented by R ₁ and R ₆ is not particularly limited as long as it is a monovalent group having an ester structural unit in its skeleton. The group having a polyester chain preferably has about 1 to about 10 ester structural units. As the ester structural unit, for example, a structural unit comprising an ester of an alkanediol having 1 to 8 carbon atoms and an alkanedicarboxylic acid or benzenedicarboxylic acid (phthalic acid) having 1 to 10 carbon atoms is preferable. An ester consisting of For example, an ester structural unit composed of ethylene glycol and succinic acid can be used.

Examples of the alkylene group and alkenylene group represented by R ₂ and R ₅ include an alkylene group and alkenylene group having 1 to 30 carbon atoms, respectively. An alkylene group and alkenylene group having 1 to 18 carbon atoms are exemplified. Further, an alkylene group having 1 to 8 carbon atoms and an alkenylene group are preferable. These may have a substituent. Moreover, as an arylene group, a phenylene group is mentioned typically and you may have a substituent. Examples of these substituents include those described above.

The divalent group having a poly (oxyalkylene) chain represented by R ₂ and R ₅ is an arbitrary group containing a poly (oxyalkylene) chain, and the poly (oxyalkylene) structural unit is and the nitrogen atom of R ₁ and urea structural units, and may, if possible attached via any divalent group directly or other nitrogen atoms of R ₆ and urea structural units. Preferred examples of the divalent group include groups such as an alkylene group (having 1 to 22 carbon atoms), an arylene group (eg, a phenylene group), an imino group, and a carbonyl group.

The divalent group having a poly (oxyalkylene) chain represented by R ₂ and R ₅ is preferably, for example,
-(R "O) _m-
In the same manner as described above, R ″ is an alkylene group having 2 to 4 carbon atoms, preferably a group such as ethylene, propylene, etc. In addition, m is 0 Represents an integer of ˜16, preferably 3˜10.

The divalent group having a polyester chain represented by R ₂ and R ₅ is not limited as long as it is a divalent group having an ester structural unit in its skeleton, and one ester structural unit is present. A group having about 10 or more is preferable. The polyester structural unit may be bonded to the nitrogen atom of R ₁ and the urea structural unit, and to the nitrogen atom of R ₆ and the urea structural unit directly or through any other divalent group. The polyester structural unit is preferably a structural unit comprising an ester of an alkanediol having 1 to 8 carbon atoms and an alkanedicarboxylic acid or benzenedicarboxylic acid (phthalic acid) having 1 to 10 carbon atoms.

These divalent groups represented by R ₂ and R ₅ may be formed by linking the divalent groups listed above.

These groups represented by R ₂ and R ₅ may be different from each other.

R ₃ and R ₄ each represent a hydrogen atom or an alkyl group, and examples of the alkyl group include an alkyl group having 1 to 6 carbon atoms. Preferred is a hydrogen atom.

Further, the number of carbon atoms of each of R ₁ , R ₆ , R ₃ and R ₅ is preferably in the range of 2 to 30, more preferably 4 to 18, and most preferably 5 to 15.

For example, even when the terminal groups R ₁ and R ₆ have the same structure, these carbon numbers may be arbitrarily different.

The groups represented by R ₁ , R ₆ , and R ₃ , R ₅ are particularly limited as long as the compound represented by the general formula [I] is dissolved in the solvent of the metal oxide fine particle dispersion. Each can optionally have an independent structure. Among these, the terminal groups R ₁ and R ₆ preferably have the same structural unit, and the terminal groups R ₁ and R ₆ and the linking groups R ₂ and R ₅ more preferably have the same structural unit.

It is preferable that at least one of R _1, R ₆ is a structure having the poly (oxyalkylene) chain (or poly (alkyleneoxy) chain), further, at least one of the end groups R _1, R ₆ More preferably, at least one of R ₃ and R ₅ has a poly (oxyalkylene) chain. Most preferably, the terminal groups R ₁ and R ₆ and the linking group R ₂ or R ₅ have a poly (oxyalkylene) chain (structural unit).

In general formula [I], n represents an integer of 1 or more. Specifically, n can be 1 or more and 1000 or less, preferably 1 or more and 100 or less, and more preferably 1 or more and 50 or less. 1 or more and 10 or less are most preferable.

Next, specific representative examples of the compound represented by the general formula [I] are shown, but the present invention is not limited thereto.

These compounds can be prepared by known methods.

The content of the urea compound represented by the general formula [I] is not particularly limited, but this compound is effective even in a small amount, and is relatively small in terms of burnout at low temperatures and film properties. It is preferable to apply at. Specifically, it is preferably 100% by mass or less, more preferably 10% by mass or more and 50% by mass or less, based on the metal oxide particles. Moreover, it is preferable that it is 20 mass% or less with respect to the whole coating liquid, and it is still more preferable that it is 1 mass% or more and 10 mass% or less.

In the present invention, the sheet-like structure formed as described above can be used as a constituent member of a surface light emitter. The place where the sheet-like structure of the present invention is used may be anywhere as long as the light extraction efficiency of the surface light emitter is improved. For example, a diffusion film for a liquid crystal backlight, a transparent substrate such as an organic EL element, an organic EL or an LED It can be used as a light extraction sheet to be bonded to the emission side surface of a surface light emitting element such as a transparent substrate or a light extraction sheet.

When the sheet-like structure of the present invention is used as a transparent substrate, the surface on which the concavo-convex structure is formed may be used on either the light-emitting side or the emission side. For example, an organic EL element on the fine concavo-convex structure side In the case of forming such a thin-film light emitting layer, a resin layer such as a hard coat material can be formed on the concavo-convex structure and smoothed for use.

On the other hand, even when the sheet-like structure of the present invention is bonded to the surface on the emission side of the surface light emitting element and used as a light extraction sheet, either side of the sheet-like structure of the present invention is set to the surface light emitting element side. It can be used in close contact with oil or adhesive, or it can be used by intentionally mixing air.

Embodiments of an organic EL device which is an example of a surface light emitter of the present invention will be described in detail below, but the contents described below are representative examples of embodiments of the present invention, and the present invention exceeds the gist thereof. As long as there is no, it is not limited to these contents.

[Organic EL device]
Preferred specific examples of the layer structure of the organic EL element are shown below.

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode Here, the light emitting layer preferably contains at least two kinds of light emitting materials having different emission colors, and a single layer or a light emitting layer comprising a plurality of light emitting layers A unit may be formed. The hole transport layer also includes a hole injection layer and an electron blocking layer.

<Light emitting layer>
The light-emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light-emitting portion is the light-emitting layer even in the light-emitting layer. It may be an interface with an adjacent layer.

The structure of the light emitting layer according to the present invention is not particularly limited as long as the contained light emitting material satisfies the above requirements.

Also, there may be a plurality of layers having the same emission spectrum or emission maximum wavelength.

It is preferable to have a non-light emitting intermediate layer between each light emitting layer.

The total film thickness of the light emitting layer is preferably in the range of 1 to 100 nm, and more preferably 30 nm or less because a lower driving voltage can be obtained. Note that the total film thickness of the light emitting layer is a film thickness including the intermediate layer when a non-light emitting intermediate layer exists between the light emitting layers.

The film thickness of each light emitting layer is preferably adjusted in the range of 1 to 50 nm, more preferably in the range of 1 to 20 nm. There is no particular limitation on the relationship between the film thicknesses of the blue, green and red light emitting layers.

For the production of the light emitting layer, a light emitting material or a host compound, which will be described later, is formed by forming a film by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, an ink jet method, or the like. it can.

A plurality of light emitting materials may be mixed in each light emitting layer, or a phosphorescent light emitting material and a fluorescent light emitting material may be mixed and used in the same light emitting layer.

In the present invention, the light emitting layer preferably contains a host compound and a light emitting material (also referred to as a light emitting dopant compound) and emits light from the light emitting material.

As the host compound contained in the light emitting layer of the organic EL device according to the present invention, a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in a light emitting layer.

As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of luminescent material mentioned later, and can thereby obtain arbitrary luminescent colors.

The host compound used may be a conventionally known low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). .

As the known host compound, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable. Here, the glass transition point (Tg) is a value determined by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

Specific examples of known host compounds include compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579 No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. No. 2002-302516, No. 2002-305083, No. 2002-305084, No. 2002-308837, and the like.

Next, the light emitting material will be described.

As the light-emitting material, a fluorescent compound or a phosphorescent material (also referred to as a phosphorescent compound or a phosphorescent compound) is used.

A phosphorescent material is a compound in which light emission from an excited triplet is observed. Specifically, a phosphorescent material emits phosphorescence at room temperature (25 ° C.) and has a phosphorescence quantum yield of 0.01 or more at 25 ° C. Although defined as a compound, the preferred phosphorescence quantum yield is 0.1 or more.

The phosphorescent quantum yield can be measured by the method described in Spectra II, page 398 (1992 version, Maruzen) of Experimental Chemistry Lecture 4 of the 4th edition. The phosphorescence quantum yield in a solution can be measured using various solvents. However, when a phosphorescent material is used in the present invention, the phosphorescence quantum yield (0.01 or more) is achieved in any solvent. Just do it.

There are two types of light emission of the phosphorescent material. In principle, the carrier recombination occurs on the host compound to which the carrier is transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent material. Energy transfer type to obtain light emission from the phosphorescent light emitting material, and another one is that the phosphorescent light emitting material becomes a carrier trap, and recombination of carriers occurs on the phosphorescent light emitting material, and light emission from the phosphorescent light emitting material is obtained. Although it is a trap type, in any case, the excited state energy of the phosphorescent material is required to be lower than the excited state energy of the host compound.

The phosphorescent light-emitting material can be appropriately selected from known materials used for the light-emitting layer of the organic EL element, and is preferably a complex compound containing a group 8-10 metal in the periodic table of elements. More preferably, an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

Fluorescent light emitters can also be used for the organic EL elements. Representative examples of fluorescent emitters (fluorescent dopants) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, and pyrylium dyes. Examples thereof include dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

Conventionally known dopants can also be used in the present invention. For example, International Publication No. 00/70655 pamphlet, JP-A Nos. 2002-280178, 2001-181616, 2002-280179, 2001 -181617, 2002-280180, 2001-247859, 2002-299060, 2001-313178, 2002-302671, 2001-345183, 2002 No. 324679, International Publication No. 02/15645, JP 2002-332291, 2002-50484, 2002-332292, 2002-83684, JP 2002-540572, JP 002-117978, 2002-338588, 2002-170684, 2002-352960, WO01 / 93642, JP2002-50483, 2002-1000047 No. 2002-173684, No. 2002-359082, No. 2002-17584, No. 2002-363552, No. 2002-184582, No. 2003-7469, No. 2002-525808. JP2003-7471, JP2002-525833A, JP2003-31366A, 2002-226495, 2002-234894, 2002-233506, 2002-2417. No. 1, No. 2001-319779, No. 2001-319780, No. 2002-62824, No. 2002-1000047, No. 2002-203679, No. 2002-343572, No. 2002-203678. Gazettes and the like.

In the present invention, at least one light emitting layer may contain two or more kinds of light emitting materials, and the concentration ratio of the light emitting materials in the light emitting layer may vary in the thickness direction of the light emitting layer.

《Middle layer》
A case where a non-light emitting intermediate layer (also referred to as an undoped region or the like) is provided between the light emitting layers will be described.

In the case of having a plurality of light emitting layers, the non-light emitting intermediate layer is a layer provided between the light emitting layers.

The film thickness of the non-light emitting intermediate layer is preferably in the range of 1 to 20 nm, and more preferably in the range of 3 to 10 nm to suppress interaction such as energy transfer between adjacent light emitting layers, and This is preferable because a large load is not applied to the voltage characteristics.

The material used for the non-light emitting intermediate layer may be the same as or different from the host compound of the light emitting layer, but may be the same as the host material of at least one of the adjacent light emitting layers. preferable.

The non-light-emitting intermediate layer may contain a non-light-emitting layer, a compound common to each light-emitting layer (for example, a host compound), and each common host material (where a common host material is used) Including the case where the physicochemical characteristics such as phosphorescence emission energy and glass transition point are the same, and the case where the molecular structure of the host compound is the same, etc.) The barrier is reduced, and the effect of easily maintaining the injection balance of holes and electrons even when the voltage (current) is changed can be obtained. Furthermore, by using a host material having the same physical characteristics or the same molecular structure as the host compound contained in each light-emitting layer in the undoped light-emitting layer, device fabrication, which is a major problem in conventional organic EL device fabrication, is achieved. Complexity can also be eliminated.

Since the host material is responsible for carrier transportation, a material having carrier transportation ability is preferable. Carrier mobility is used as a physical property representing carrier transport ability, but the carrier mobility of an organic material generally depends on the electric field strength. Since a material having a high electric field strength dependency easily breaks the balance between injection and transport of holes and electrons, it is preferable to use a material having a low electric field strength dependency of mobility for the intermediate layer material and the host material.

On the other hand, in order to optimally adjust the injection balance of holes and electrons, it is also preferable that the non-light emitting intermediate layer functions as a blocking layer described later, that is, a hole blocking layer and an electron blocking layer. It is done.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm, although it depends on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL elements and their forefront of industrialization” (published by NTT Corporation on November 30, 1998). There is a hole blocking (hole blocking) layer.

In a broad sense, the hole blocking layer has a function of an electron transport layer and is composed of a hole blocking material having a function of transporting electrons and having a remarkably small ability to transport holes, while transporting electrons. By blocking holes, the recombination probability of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer.

On the other hand, the electron blocking layer, in a broad sense, has a function of a hole transport layer, and is made of a material having a function of transporting holes while having a remarkably small ability to transport electrons, while transporting holes. By blocking electrons, the probability of recombination of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transporting layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

The hole transport material has either hole injection or transport or electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl; N, N′-diphenyl-N, N′— Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' Di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino -(2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

Further, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

Also, JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained.

The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. The thickness of the hole transport layer is not particularly limited, but is usually about 5 nm to 5 μm, preferably 5 to 200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

It is also possible to use a hole transport layer having a high p property doped with impurities. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

It is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be manufactured.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as electron transport materials. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Further, the distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the electron transport material, and inorganic semiconductors such as n-type-Si and n-type-SiC can be used as well as the hole injection layer and the hole transport layer. It can be used as an electron transport material.

The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. The thickness of the electron transport layer is not particularly limited, but is usually about 5 nm to 5 μm, preferably 5 to 200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

It is also possible to use an electron transport layer having a high n property doped with impurities. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be produced.

《Counter electrode》
The counter electrode is an electrode facing the transparent conductive layer. In the present invention, since the transparent conductive layer is mainly used as an anode, the following cathode can be used as the counter electrode. As the cathode, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

In addition, a transparent or semi-transparent cathode can be produced by producing a conductive transparent material on the cathode after the metal is produced with a thickness of 1 nm to 20 nm on the cathode. An element in which both the anode and the cathode are transmissive can be manufactured.

[Method for producing organic EL element]
An organic EL element can be produced by sequentially forming a transparent conductive layer, an organic electroluminescence layer, and a counter electrode on a transparent substrate.

<< Formation of transparent conductive layer >>
A transparent conductive layer can be formed on a transparent substrate using a desired electrode material. For example, when ITO (indium oxide added with tin) is used as the electrode material, the transparent conductive layer can be formed by a method such as vapor deposition or sputtering. In addition, a transparent conductive layer can be formed from a material containing metal nanowires, a conductive polymer, or a transparent conductive metal oxide by a liquid phase film forming method such as a coating method or a printing method.

From the viewpoint of improving productivity, improving electrode quality such as smoothness and uniformity, and reducing environmental impact, it is possible to form a transparent conductive layer containing metal nanowires by a liquid phase film-forming method such as a coating method or a printing method. preferable. As coating methods, roll coating method, bar coating method, dip coating method, spin coating method, casting method, die coating method, blade coating method, bar coating method, gravure coating method, curtain coating method, spray coating method, doctor coating method Etc. can be used. As the printing method, a letterpress (letter) printing method, a stencil (screen) printing method, a lithographic (offset) printing method, an intaglio (gravure) printing method, a spray printing method, an ink jet printing method, and the like can be used. In addition, as necessary, physical surface treatment such as corona discharge treatment or plasma discharge treatment can be applied to the surface of the releasable substrate as a preliminary treatment for improving the adhesion and coating properties.

<< Formation of organic electroluminescence layer >>
A layer formed between the transparent conductive layer and the cathode, consisting of all or part of the anode buffer layer, hole transport layer, light emitting layer, hole blocking layer, electron transport layer, and cathode buffer layer is called an organic electroluminescence layer. . As an example of a method for producing this organic electroluminescence layer, a method for producing an organic electroluminescence layer comprising a hole injection layer / a hole transport layer / a light emitting layer / a hole blocking layer / an electron transport layer will be described.

An organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are organic EL element materials, is formed on a transparent substrate on which a transparent conductive layer is formed.

As a method for thinning the organic compound thin film, there are a vapor deposition method and a wet process (spin coating method, casting method, ink jet method, printing method) as described above, but it is easy to obtain a uniform film and a pinhole. From the point of being difficult to form, a vacuum deposition method, a spin coating method, an ink jet method, and a printing method are particularly preferable. Further, different film forming methods may be applied for each layer. When a vapor deposition method is employed for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a degree of vacuum of 10 ⁻⁶ to 10 ⁻² Pa, and a vapor deposition rate of 0.01 to It is desirable to select appropriately within the range of 50 nm / second, substrate temperature −50 to 300 ° C., film thickness 0.1 nm to 5 μm, preferably 5 to 200 nm.

<Formation of cathode>
After forming the above organic electroluminescence layer, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 50 to 200 nm. Is provided.

A desired organic EL element is obtained by the above steps. The organic EL element is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

It is also possible to reverse the production order to produce a cathode, an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, a hole injection layer, and an anode in this order. When a DC voltage is applied to the multicolor liquid crystal display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

[Use]
The surface light emitter according to the present invention can be used as a display device, a display, and various light sources. Examples of light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, and light sources for optical sensors. Although it is not limited to this, it can be effectively used for a backlight of a liquid crystal display device combined with a color filter and a light source for illumination.

[Lighting device]
The sheet-like structure of the present invention can be applied to an organic EL element that is one of surface light emitters. As an organic EL element, a plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of blue, green, and blue, or two using the relationship of complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.

In addition, a combination of light emitting materials for obtaining a plurality of emission colors includes a combination of a plurality of phosphorescent or fluorescent materials (light emitting dopants), a light emitting material that emits fluorescent or phosphorescent light, and the light emission. Any combination of a dye material that emits light from the material as excitation light may be used, but in the white organic EL device according to the present invention, a method of combining a plurality of light-emitting dopants is preferable.

As a layer structure of the organic EL element for obtaining a plurality of emission colors, a method of having a plurality of emission dopants in one emission layer, a plurality of emission layers, and an emission wavelength of each emission layer. Examples thereof include a method in which different dopants are present, and a method in which minute pixels emitting light of different wavelengths are formed in a matrix.

In the white organic EL device according to the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like at the time of film formation, if necessary. When patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire element layer may be patterned.

The light emitting material used for the light emitting layer is not particularly limited. For example, in the case of a backlight in a liquid crystal display element, the platinum complex according to the present invention is known so as to be suitable for the wavelength range corresponding to the CF (color filter) characteristics. Any one of the light emitting materials may be selected and combined to be whitened.

Thus, in addition to the display device and the display, the white organic EL element is used as a liquid crystal display device as a kind of lamp such as various light emitting light sources and lighting devices, home lighting, interior lighting, and exposure light source. It is also useful for display devices such as backlights.

In addition, backlights such as clocks, signboard advertisements, traffic lights, light sources such as optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processing machines, light sources for optical sensors, etc. There are a wide range of uses such as household appliances.

Hereinafter, although an example is given and the present invention is explained, the present invention is not limited to this.

Example 1
<< Preparation of amorphous titanium oxide dispersion 1 >>
10 g of 50% titanium tetrachloride solution (manufactured by Sumitomo Sitix Co., Ltd.) is added to 500 ml of water, and a solution made up to 1000 ml by adding pure water is prepared. 2.5% aqueous ammonia was added dropwise thereto to adjust the pH to 6.9, and titanium hydroxide was precipitated. The precipitate is continuously washed with pure water so that the electrical conductivity in the supernatant is 0.8 mS / m or less, and when the electrical conductivity is 0.738 mS / m, the washing is terminated, and then 0.73 mass%. 430 g of a hydroxide-containing liquid having a concentration was produced.

Next, 25 g of 35% aqueous hydrogen peroxide was added while cooling this containing liquid to 1 to 5 ° C., and stirred for 16 hours to obtain 450 g of a pale yellowish brown 0.86 mass% concentration dispersion. This was designated as amorphous type titanium oxide dispersion 1.

<< Preparation of amorphous titanium oxide dispersion 2 >>
10 g of 50% titanium tetrachloride solution (manufactured by Sumitomo Sitix Co., Ltd.) is added to 500 ml of water, and a solution made up to 1000 ml by adding pure water is prepared. 2.5% aqueous ammonia was added dropwise thereto to adjust the pH to 6.9, and titanium hydroxide was precipitated. The precipitate is continuously washed with pure water so that the electrical conductivity in the supernatant is 0.8 mS / m or less, and when the electrical conductivity is 0.738 mS / m, the washing is terminated, and then 0.73 mass%. 430 g of a hydroxide-containing liquid having a concentration was produced.

Next, 25 g of 35% hydrogen peroxide solution was added to this liquid mixture at room temperature and stirred for 16 hours to obtain 450 g of a pale yellowish brown 0.86 mass% dispersion. This was designated as amorphous type titanium oxide dispersion 2.

<< Preparation of Amorphous TiO ₂ -ZrO ₂ Dispersion >>
A solution in which pure water was added to a solution obtained by completely dissolving 1.696 g of ZrCl ₂ O.8H ₂ O (oxyzircon chloride) in 20 g of a 50% titanium tetrachloride solution (manufactured by Sumitomo Sitix Co., Ltd.) was prepared to make 2000 ml. . 2.5% aqueous ammonia was added dropwise thereto to adjust the pH to 7.0, and a mixture of zirconium hydroxide and titanium hydroxide was precipitated. When this precipitate is washed with pure water by decantation washing so that the conductivity of the supernatant liquid becomes 0.8 mS / m or less, and the washing is finished when the conductivity becomes 0.702 mS / m, 0.79 mass% A concentration of 626 g of hydroxide was produced.

Next, 56 g of 35% hydrogen peroxide solution was added to the liquid mixture at room temperature and stirred for 16 hours to obtain 680 g of a yellowish brown 0.88 mass% concentration dispersion. This was used as an amorphous TiO ₂ —ZrO ₂ dispersion.

<< Preparation of coating solution 1 >>
The amorphous titanium oxide dispersion liquid 1 was used as the coating liquid 1 as it was.

<< Preparation of coating liquid 2 >>
The amorphous titanium oxide dispersion 2 was used as the coating solution 2 as it was.

<< Preparation of coating solution 3 >>
The amorphous TiO ₂ —ZrO ₂ dispersion was used as coating solution 3 as it was.

<< Preparation of coating solution 4 >>
2 mass% of Exemplified Compound 1 was added to the amorphous titanium oxide dispersion 1 and stirred to obtain a coating solution 4.

<< Preparation of coating solution 5 >>
2% by weight of Exemplified Compound 1 was added to niobium oxide sol (Viral Nb-G6000, manufactured by Taki Chemical Co., Ltd.) and stirred to obtain Coating Solution 5.

A sheet on which a light extraction layer was formed using the coating solutions 1 to 5 was prepared.

<< Production of Sheet 1 >>
The coating solution 1 was applied to one side of a 100 μm thick biaxially stretched PEN film (manufactured by Teijin DuPont; refractive index 1.75) so as to have a dry film thickness of 1 μm, and dried in an oven at 80 ° C. for 1 minute. . Thereafter, plasma treatment was performed under the following conditions to obtain a sheet-like structure having a concavo-convex structure formed by an aggregate of metal oxide fine particles on one side of the PEN film. By TEM observation of the cross section of the substantially central portion of the obtained sheet and AFM measurement of the surface of the substantially central portion with a field of view of 80 μm on one side, an aggregate of titanium oxide fine particles having an average particle size of 5 nm can be obtained. It was confirmed that uneven structures having a thickness of 50 nm were formed with an average period of 10 nm, and this was designated as sheet 1.

(Plasma treatment conditions)
Carrier gas: Nitrogen (under atmospheric pressure)
Reactive gas: Oxygen (4% by volume with respect to nitrogen)
1st power supply: HEIDEN Laboratory PHF-6k (100kHz)
Second power supply: Pearl Industrial CF-5000-13M (13.56MHz)
Applied output: 1.0 W / cm ²
Electrode temperature control: 80 ° C
Processing time: 20 seconds << Preparation of sheet 2 >>
Except for changing the coating liquid 1 to the coating liquid 2, a sheet 2 having a concavo-convex structure formed of aggregates of metal oxide fine particles on one side of the PEN film was obtained in the same manner as the production of the sheet 1. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that an uneven structure having an average depth of 400 nm was formed with an average period of 100 nm by an aggregate of titanium oxide fine particles having an average particle diameter of 35 nm.

<< Production of Sheet 3 >>
Except for changing the coating liquid 1 to the coating liquid 3, a sheet 3 having a concavo-convex structure formed of aggregates of metal oxide fine particles on one side of the PEN film was obtained in the same manner as the production of the sheet 1. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that an uneven structure having an average depth of 200 nm was formed with an average period of 200 nm by an aggregate of composite fine particles of titanium oxide and zirconium oxide having an average particle diameter of 20 nm.

<< Production of Sheet 4 >>
In the method for producing the sheet 3, the transparent resin film was changed to a biaxially stretched PET film having a thickness of 100 μm (manufactured by Teijin DuPont; refractive index: 1.65). A sheet 4 having a concavo-convex structure formed of an aggregate of metal oxide fine particles on one side was obtained. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that an uneven structure having an average depth of 250 nm was formed with an average period of 200 nm by an aggregate of composite fine particles of titanium oxide and zirconium oxide having an average particle diameter of 20 nm.

<< Production of Sheet 5 >>
The coating solution 3 was applied to one side of a 100 μm-thick biaxially stretched PEN film (manufactured by Teijin DuPont; refractive index 1.75) so as to have a dry film thickness of 1 μm, and dried in an oven at 80 ° C. for 1 minute. . Thereafter, using a microwave reactor manufactured by Shikoku Keikoku Kogyo Co., Ltd., a 2.45 GHz microwave was irradiated at an output of 600 W for 2 minutes, and a sheet 5 having a concavo-convex structure formed of aggregates of metal oxide fine particles on one side of the PEN film was formed. Obtained. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that an uneven structure having an average depth of 100 nm was formed with an average period of 150 nm by an aggregate of composite fine particles of titanium oxide and zirconium oxide having an average particle diameter of 20 nm.

<< Production of Sheet 6 >>
The coating solution 1 was applied to one side of a 100 μm thick biaxially stretched PEN film (manufactured by Teijin DuPont; refractive index 1.75) so as to have a dry film thickness of 1 μm, and dried in an oven at 80 ° C. for 1 minute. . Thereafter, using a high-pressure mercury lamp, 200 W / cm ² of ultraviolet light was irradiated for 15 minutes to obtain a sheet 6 having a concavo-convex structure formed of aggregates of metal oxide fine particles on one side of the PEN film. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that an uneven structure having an average depth of 5 nm was formed with an average period of 250 nm by an aggregate of titanium oxide fine particles having an average particle diameter of 5 nm.

<< Production of Sheet 7 >>
The coating solution 4 was applied to one side of a 100 μm thick biaxially stretched PEN film (manufactured by Teijin DuPont; refractive index 1.75) so as to have a dry film thickness of 1 μm, and dried in an oven at 80 ° C. for 1 minute. . Thereafter, the temperature of the oven was raised to 120 ° C., and a heat treatment was further performed for 5 hours to obtain a sheet 7 having a concavo-convex structure formed by an aggregate of metal oxide fine particles on one side of the PEN film. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that a concavo-convex structure having an average depth of 150 nm was formed with an average period of 30 nm by an aggregate of titanium oxide fine particles having an average particle diameter of 5 nm.

<< Production of Sheet 8 >>
The coating solution 5 was applied to one side of a 100 μm thick biaxially stretched PEN film (manufactured by Teijin DuPont; refractive index 1.75) so as to have a dry film thickness of 1 μm, and dried in an oven at 80 ° C. for 1 minute. . Thereafter, using a microwave reactor manufactured by Shikoku Keikoku Kogyo Co., Ltd., a 2.45 GHz microwave was irradiated at an output of 600 W for 2 minutes, and a sheet 8 having a concavo-convex structure formed of aggregates of metal oxide fine particles on one side of the PEN film was formed. Obtained. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that a concavo-convex structure having an average depth of 400 nm was formed with an average period of 350 nm by an aggregate of composite fine particles of niobium oxide having an average particle diameter of 20 nm.

<< Production of Sheet 9 >>
As a comparative example, a sheet 9 having a concavo-convex shape made of a resin was produced by the following method with reference to JP-A No. 2004-45471. Biaxially-stretched PET film with a thickness of 100 μm using a roll intaglio with fine concavo-convex shape formed on the surface after chromium plating on the iron core surface, # 250 liquid sand blasting treatment, and chrome plating treatment again A concavo-convex shape made of a curable acrylic resin having a refractive index of 1.54 was formed on one surface (manufactured by Teijin DuPont; refractive index 1.65). As a result of evaluation by the same method as that for the sheet 1, it was confirmed that a random uneven shape with an average depth of 1.2 μm and an interval between protrusions of 0.5 to 2.0 μm was formed.

<< Production of Sheet 10 >>
As a comparative example, a sheet 10 having a concavo-convex shape formed of a resin containing fine particles was produced by the following method. In the method for producing the sheet 9, except that the curable resin to be used is changed to a resin in which 10% by mass of titanium oxide fine particles having a particle diameter of 200 nm are dispersed in an acrylic resin having a refractive index of 1.54, Similarly, a sheet 10 was produced. As a result of evaluation by the same method as that for the sheet 1, a random uneven shape having an average depth of 1.0 μm and an interval between protrusions of 0.1 to 1.5 μm is formed, and the protrusions are partially missing. The shape was confirmed.

<< Production of Sheet 11 >>
As a comparative example, a sheet 11 on which a titanium oxide film having no uneven structure was formed by the following method. The coating solution 1 was applied to one side of a 100 μm thick biaxially stretched PEN film (manufactured by Teijin DuPont; refractive index 1.75) so as to have a dry film thickness of 1 μm, and dried in an oven at 80 ° C. for 1 minute. . Thereafter, the temperature of the oven was raised to 100 ° C., and a heat treatment was further performed for 5 hours to obtain a sheet 11. As a result of evaluation by the same method as that for the sheet 1, it was confirmed that a concavo-convex structure due to the aggregate of metal oxide fine particles was not formed, and a smooth titanium oxide layer was formed with titanium oxide fine particles having an average particle diameter of 5 nm.

<Evaluation of sheet-like structure>
The obtained sheets 1 to 11 were evaluated by the following method.

(Water vapor transmission rate)
The water vapor transmission rate was measured based on the JIS standard K7129 method (temperature 40 ° C., humidity 90% RH) using the MOCON method and PERMATRAN-W3 / 33 manufactured by MOCON. As a result, the sheets 1 to 8 were less than the measurement limit (0.01 g / m ² / day) of the Mocon method, and it was found that the moisture resistance was improved with respect to the sheets 9, 10, and 11. The results are shown in Table 1 as water vapor barrier properties.

[Light extraction efficiency]
<< Production of Organic EL Element 1 >>
ITO (Indium Tin Oxide; refractive index: 1.85) is deposited on a 100-nm thick biaxially stretched PEN film (manufactured by Teijin DuPont; refractive index 1.75) and patterned, and then the ITO conductivity is measured. The substrate provided with the layer was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes. A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water on this substrate was spin-coated at 3000 rpm for 30 seconds. After film formation by the method, the substrate was dried at a substrate surface temperature of 200 ° C. for 1 hour to provide a hole injection layer having a thickness of 30 nm.

This substrate was transferred to a glove box in accordance with JIS B 9920 under a nitrogen atmosphere, with a measured cleanliness of class 100, a dew point temperature of −80 ° C. or lower, and an oxygen concentration of 0.8 ppm. A coating solution for a hole transport layer was prepared as follows in a glove box, and applied with a spin coater under conditions of 1500 rpm and 30 seconds. This substrate was dried by heating at a substrate surface temperature of 150 ° C. for 30 minutes to provide a hole transport layer. The film thickness was 20 nm when it apply | coated and measured on the conditions with the board | substrate prepared separately.

(Coating liquid for hole transport layer)
Monochlorobenzene 100g
Poly-N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) benzidine (ADS254BE: manufactured by American Die Source)
0.5g
Subsequently, the light emitting layer coating liquid was prepared as follows, and it apply | coated on 2000 rpm and the conditions for 30 seconds with the spin coater. Furthermore, it heated at the substrate surface temperature of 120 degreeC for 30 minutes, and provided the light emitting layer. When the coating was performed under the same conditions on a separately prepared substrate and measured, the film thickness was 40 nm. Of the following light emitting layer compositions, HA showed the lowest Tg, which was 132 ° C.

(Light emitting layer coating solution)
Butyl acetate 100g
HA 1g
DA 0.11g
DB 0.002g
DC 0.002g
Subsequently, the coating liquid for electron carrying layers was prepared as follows, and it apply | coated on the conditions of 1500 rpm and 30 seconds with a spin coater. Furthermore, it heated for 30 minutes at the substrate surface temperature of 120 degreeC, and provided the electron carrying layer. The film thickness was 30 nm when it applied and measured on the conditions prepared with the board | substrate prepared separately.

(Coating liquid for electron transport layer)
2,2,3,3-tetrafluoro-1-propanol 100g
ET-A 0.75g
Next, the substrate provided up to the electron transport layer was moved to a vapor deposition machine without being exposed to the atmosphere, and the pressure was reduced to 4 × 10 ⁻⁴ Pa. Note that potassium fluoride and aluminum were each placed in a tantalum resistance heating boat and attached to a vapor deposition machine.

First, a resistance heating boat containing potassium fluoride was energized and heated to provide a 3 nm electron injection layer made of potassium fluoride on the substrate. Subsequently, a resistance heating boat containing aluminum was energized and heated, and a cathode having a thickness of 100 nm made of aluminum was provided at a deposition rate of 1 to 2 nm / second.

The surface opposite to the organic EL layer of the transparent substrate constituting the organic EL element 1 thus fabricated and the surface of the sheets 1 to 11 where the light extraction layer is not formed are the same as the transparent substrate. It was made to adhere through a matching oil having a refractive index of. Thereafter, the organic EL element 1 was caused to emit light by passing a constant current of ^2.5 mA / cm ² , and the sheets 1 to 11 were evaluated. For measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used, and the front luminance and light extraction efficiency without a sheet were set to 100, and relative values were obtained. The obtained results are shown in Table 1.

From Table 1, it can be seen that the sheet-like structure of the present invention has a high effect of improving the light extraction efficiency, and has excellent water vapor barrier properties and high durability. Moreover, it turns out that the thing which disperse | distributed the titanium oxide particle in the curable resin of the sheet | seat 10 and formed uneven | corrugated shape is inferior to the thing formed by combining the metal oxide fine particle of this invention.

Example 2
<< Production of organic EL elements 2 to 6 >>
Using the sheets 1, 3, 4, 9, and 10 prepared in Example 1 as the substrate, the ITO transparent conductive layer and the organic electrolayer were formed on the opposite surface on which the light extraction layer was formed in the same manner as the organic EL element 1 was manufactured. A luminescence layer and a cathode were formed, and organic EL elements 2 to 4 using the sheet-like structure of the present invention as a substrate and comparative organic EL elements 5 and 6 were produced.

<< Evaluation of organic EL elements >>
[External extraction quantum efficiency]
With respect to the produced organic EL element, the external extraction quantum efficiency (%) when a constant current of ^2.5 mA / cm ² was passed was measured under an inert gas atmosphere. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used. The obtained results are shown in Table 2 as relative values when the measured value of the organic EL element 1 is 100.

[Heating durability test]
The produced organic EL elements were observed visually for 24 hours after being stored in a constant temperature bath at 100 ° C. and 40% RH, and the following ranking was performed.

O: Bright spots or black spots are observed, but stable light emission is observed. Δ: Bright spots or black spots are observed, and the emission luminance is unstable. X: No light emission The results obtained are shown in Table 2.

From Table 2, it can be seen that the organic EL device having the configuration of the present invention has high external extraction quantum efficiency and excellent durability against heating.

Example 3
After sticking the sheet | seat 3 to the light-projection surface side of the organic EL element 1 of this invention produced in Example 1, it covers with a transparent barrier film (transparent resin film coat | covered with the silicon dioxide film), and a flexible surface light emitter and did. The surface light emitter according to the present invention can be used as a thin illuminating device that emits white light having a long light emission life while maintaining high light emission efficiency even with a slight bending motion.

DESCRIPTION OF SYMBOLS 30 Atmospheric pressure plasma processing apparatus 31 Atmospheric pressure plasma processing container 32 Discharge space 36 Rectangular tube electrode 40 Electric field application means 41 1st power supply 42 2nd power supply 43 1st filter 44 2nd filter 50 Gas supply means 51 Gas generator 52 Supply Air outlet 53 Air outlet 60 Electrode temperature adjusting means 64 Guide roll 65

Nip roll

68, 69 Partition plate F Substrate G 'Processing exhaust port 36a Square tube electrode 36A Metal base 36B Dielectric coating layer

Claims

A sheet-like structure characterized in that a light extraction layer having a concavo-convex structure made of an aggregate of metal oxide fine particles is provided on a transparent substrate.
The sheet-like structure according to claim 1, wherein the transparent substrate is a transparent resin film.
The sheet-like structure according to claim 1 or 2, wherein the uneven structure is a periodic uneven structure having an average depth of 5 nm to 300 nm and an average period of 10 nm to 300 nm.
4. The sheet-like structure according to claim 1, wherein the metal oxide fine particles are amorphous metal oxide fine particles having an average particle diameter of 1 nm or more and 30 nm or less.
5. The metal oxide fine particles are oxide fine particles composed of Group 4 or Group 5 elements or composite oxide fine particles composed of Group 4 and Group 5 elements. The sheet-like structure according to 1.
The method for producing a sheet-like structure according to any one of claims 1 to 5, wherein a step of applying a dispersion containing metal oxide fine particles to at least one surface of the transparent substrate, and a softening point temperature of the substrate A method for producing a sheet-like structure, which is produced by a step of drying below and a step of forming an uneven structure comprising an aggregate of the metal oxide fine particles by an external stimulus treatment.
The method for producing a sheet-like structure according to claim 6, wherein the external stimulation treatment is a treatment selected from plasma discharge treatment, microwave irradiation treatment, and ultraviolet irradiation treatment.
A surface light emitter using the sheet-like structure according to any one of claims 1 to 5 as a transparent substrate.
A surface light emitter comprising the sheet-like structure according to any one of claims 1 to 5 bonded to a surface on a light emission side.