WO1992012006A1

WO1992012006A1 - Damping composite metal plate and production thereof

Info

Publication number: WO1992012006A1
Application number: PCT/JP1991/001756
Authority: WO
Inventors: Seiichi Matsuo; Takahiro Nakano; Mika Kubo
Original assignee: Nippon Paint Co., Ltd.
Priority date: 1990-12-28
Filing date: 1991-12-25
Publication date: 1992-07-23
Also published as: JPH05293924A

Abstract

A damping composite metal plate comprising metal plates and, sandwiched therebetween, an adhesive comprising a latex composition containing an ethylenically unsaturated carboxylic acid/butadiene copolymer rubber and a carboxylated olefin copolymer resin. The use of the adhesive containing the copolymer rubber component makes it possible to produce a composite metal plate excellent in adhesion and vibration damping properties.

Description

Specification

Vibration damping composite metal sheet and its manufacturing method

Technical field

The present invention relates to a vibration-damping composite metal plate and a method for producing the same. In particular, the present invention relates to a composite metal sheet used for transportation machines, building structures, electric parts, etc., having a high vibration damping ability and capable of withstanding complicated processing, and a method for producing the same.

Background art

Conventionally, a composite metal plate used to prevent noise or vibration

(Damping plate) is made by bonding two metal plates with an adhesive having vibration damping (damping) properties. In recent years, this damping steel plate has been used for oil pans and outer panels of washing machines for the purpose of reducing noise in automobile interiors and reducing noise when using a washing machine in an apartment house.

However, while the currently used vibration damping plates are very effective in terms of noise control, they have the disadvantage that they cannot be applied to parts that require complicated processing or thick plates that have large processing deformation force. Have. Therefore, it is currently used only for thin boxes such as oil pans and washing machine outer panels. Absent.

Conventionally, as the adhesive used for the damping steel sheet, a film adhesive formed by heating a resin or a liquid adhesive obtained by dissolving a resin in an organic solvent has been used. However, this film type can be formed without difficulty if it is a film of 100 or more due to the necessity of heat-melt molding.However, it is difficult to control the film thickness of a film of 50 ^ or less that is actually used. The cost is also high. On the other hand, the solvent-based liquid type has problems in working environment, air pollution, etc.

Disclosure of the invention

The present inventors have studied the problems of known adhesives for vibration damping, and found that a butadiene-based copolymer obtained by copolymerizing a carboxyl group-containing olefin copolymer emulsion (B) and an ethylenically unsaturated carboxylic acid. Damping steel sheets bonded with an adhesive mainly composed of synthetic rubber latex (A) have excellent adhesion between metal plates, so they can withstand complicated processing and can be used to produce thick vibration-damping steel sheets. I found something. In addition, it has good vibration damping properties in the range from normal temperature to high temperature, and since the adhesive is an aqueous dispersion, The present inventors have found that the harmful organic solvent is not generated even in the production process, and that it is easy to control the thickness of the adhesive before and after 50, thereby completing the present invention.

That is, the present invention provides a vibration-damping composite metal plate having an adhesive layer between metal plates, wherein the adhesive is (A) an ethylenically unsaturated carboxylic acid-butadiene copolymer rubber and (B) A vibration-damping composite metal plate, which is a latex composition containing a carboxyl group-containing copolymer resin, and a method for producing the same.

The reason why the vibration-damping steel sheet of the present invention has excellent workability is that the component (B) is disposed at the metal interface inside the adhesive layer, and the strong interfacial adhesive force causes the adhesive layer to peel off from the metal during processing deformation. It is thought to prevent. On the other hand, the component (A) is mainly located in the middle of the adhesive layer and plays a role in relieving excessive adhesive stress from concentrating on the adhesive interface by easily deforming the adhesive layer during working deformation due to its strong plasticity. it is conceivable that

Ethylenically unsaturated carboxylic acid compounded in the adhesive used in the present invention —Butadiene copolymer rubber (A) is prepared by copolymerizing ethylenically unsaturated carboxylic acid and butadiene as essential monomers. Examples of the ethylenically unsaturated carboxylic acid include maleic acid, atalylic acid, methacrylic acid and the like. In addition, other polymerizable monomers may be added as needed. Other polymerizable monomers include, for example, styrene, acrylonitrile, acrylate, methacrylate, and the like. Any of the above monomers may be used alone.

The copolymer rubber (A) is preferably obtained as a latex by emulsion polymerization in an aqueous medium in the presence of a polymerization initiator, an emulsifier and the like. In the emulsion polymerization composition, the ethylenically unsaturated carboxylic acid is preferably 2 to 20% by weight (particularly 5 to 15% by weight), and the butadiene is preferably 40 to 98% by weight, based on the total monomer weight. If the amount of the carboxylic acid is less than 2% by weight, the compatibility with the component (B) is poor, and phase separation occurs after mixing. Further, the workability cannot be satisfied due to a decrease in the adhesion between the component (B) and the interlayer after bonding. On the other hand, if the content exceeds 20% by weight, the vibration-damping properties decrease, Stress concentration cannot be alleviated, resulting in poor workability. The copolymer rubber latex (A) obtained as described above preferably has a nonvolatile content of 40 to 60% by weight.

The carboxyl group-containing olefin copolymer resin (B) to be incorporated into the adhesive used in the present invention is prepared by copolymerizing olefin and an ethylenically unsaturated carboxylic acid as essential monomers. Examples of the olefin include ethylene and propylene. Examples of the ethylenically unsaturated carboxylic acid include those exemplified for the copolymer rubber. In addition, other polymerizable monomers (for example, those exemplified in the above-mentioned copolymer rubber) may be added as necessary. Any of the above monomers may be used alone.

In the copolymer composition, those containing 10 to 25% by weight of ethylenically unsaturated carboxylic acid have good adhesive strength and are easy to emulsify.

In the preparation of the adhesive used in the present invention, the copolymer resin (B) is preferably blended in the form of an emulsion. Copolymer resin (B) Emma The preparation of lucion is carried out, for example, by preparing the above copolymer resin (B) in an aqueous medium and a base (for example, ammonia, morpholine, alkanol) in an amount sufficient for the copolymer resin (B) to form a water and oil-in-water emulsion. Or caustic soda) and stirring at 80-200¾ for 0.5-2 hours.

In the present invention, a latex adhesive obtained by mixing the above components (A) and (B) is used, and the mixing ratio is 10:90 to 90:10, preferably 70:30 to 70, in terms of resin weight ratio. It is desirable to select arbitrarily in the range of 30:70 in accordance with the balance between workability and vibration damping required by the place where the composite metal sheet is used. The resin concentration is preferably 20 to 50% by weight.

The adhesive thus obtained may be used as it is, but may also be used as epoxy resin (for example, bisphenol A type epoxy resin, novolak type epoxy resin, alkylene glycol type epoxy resin, etc.) Components that can react with carboxyl groups in the adhesive, such as melamine resin and urea resin, may be added. further Conventional fillers, dispersants, thickeners, surfactants, flame retardants, coupling agents, and the like may be added and used as long as the object of the present invention can be achieved. Furthermore, when it is desired to provide spot weldability to the composite metal sheet of the present invention, metal powder (fine powder of iron, copper, nickel, aluminum, zinc, and alloys containing these metals) or conductive powder in the adhesive is used. This can be achieved by mixing 1 to 100 parts by weight of the filler with respect to 100 parts by weight of the adhesive. Preferably, the metal powder and the conductive filler are classified, and the particle size is adjusted to 0.5 to 1.5 times the thickness of the adhesive layer, and then 1 to 10 parts by weight is added to the adhesive and stirred. Use of the adhesive as an adhesive provides good spot weldability.

The vibration-damping composite metal plate of the present invention is manufactured by bonding both metal plates with the adhesive obtained above. That is, the metal plate of the present invention has a structure having the above-mentioned adhesive layer between the metal plates. In order to obtain a stronger interfacial adhesive force, the above-mentioned olefin copolymer resin (B) layer may be further provided between the adhesive layer and the metal plate. Specific examples of such a cross-sectional structure of the metal plate of the present invention are shown in FIGS. 1 to 3 (however, these are not limited, and It is only for the purpose of more clearly explaining the structure of the present invention, and the thickness, size, shape, etc. are not shown in consideration of the structure. ). In the figure, the material of the metal plate (1) is not particularly limited, but may be, for example, iron, aluminum, copper, titanium, nickel, or an alloy containing these metals (eg, stainless steel, brass, etc.). . The thickness of the metal plate (1) is not particularly limited, but may be, for example, 0.1 to 1 Omm. The shape of the metal plate (1) is not limited to a plate shape, but may be a tubular shape or a rod shape. The thicknesses of the adhesive layer (2) and the olefin copolymer resin (B) layer (3) are also appropriately selected, and may be, for example, 30 to 300 / m and 1 to 10 ^ ra, respectively. The composite metal plate of the present invention having a T peel adhesion strength (JI SK 6854) of 10 to 30 (kg / 25 hidden), and a tensile shear bonding strength (JI SK 6850) of 180 to 240 (kg Zcra ² ), There is no deviation in 90 ° bending as defined in the examples described below.

The composite metal plate of the present invention as described above is produced, for example, by applying an adhesive to one or both metal plates, drying and applying heat and pressure. Specifically, the adhesive is applied to one or both metal plates with a usual coating machine such as a roll coater, a curtain coater, a spray coater or the like so as to have a dry film thickness of, for example, 0.5 to 0.01. After heating at 80 to 200 ° C for 1 to 10 minutes to evaporate water, set the bonded part to reach a temperature of, for example, 120 to 220 ° C using a heat press or a heat roll. To complete the bonding. Further, it is desirable to cool under pressure after heat and pressure bonding. Alternatively, for the purpose of streamlining the production, it is preferable to apply the adhesive, then dry at, for example, 120 to 220 ° C., and press-bond directly using the temperature after drying. As a more rational production method, it can be applied to a hot plate immediately after the rolling process, dried by preheating, and then immediately pressed. In this case, in order to apply the composition on a hot plate having a pressing temperature (for example, 120 to 220 ° C.) or more, it is desirable to apply a thin film of 1 to 10 ^ a plurality of times using a spray coater or the like.

Further, as an alternative to the above-mentioned production method, a dry film of an adhesive or a composite film in which one or both surfaces of a dry film of an adhesive are coated with the above-mentioned copolymer (B) is sandwiched between metal plates, and then heated and pressed. And the book The composite metal plate of the invention can be manufactured. The dried film of the adhesive is prepared by, for example, applying an adhesive on an easily peelable sheet (for example, a Teflon sheet), drying at 80 to 200 ° C. for 1 to 10 minutes, and then peeling the sheet. can get. The composite film can be obtained by applying an emulsion of the resin copolymer (B) on one or both surfaces of the dried film thus obtained, for example, by using a spray coater or the like, followed by drying. Next, the dried film or composite film is sandwiched between metal plates and heated and pressed in the same manner as above to obtain the composite metal plate of the present invention.

In any of the above manufacturing methods, one or both of the metal plates may be the same as those described above. However, a resin which has been previously coated and dried with an emulsion copolymer resin (B) emulsion is used. A coated metal plate may be used (that is, in the present invention, the “metal plate” refers to the resin-coated metal plate as well.

3 ).

Example

Hereinafter, the present invention will be described more specifically with reference to Examples.

Preparation of adhesive 60 parts by weight of butadiene, 20 parts by weight of styrene, 10 parts by weight of methyl methacrylate, and 100 parts by weight of acrylic acid 100 parts by weight, 130 parts by weight of water, and 2 parts by weight of surfactant Then, 1 part by weight of ammonium persulfate was placed in an autoclave and reacted with stirring at 4 to 6 atm at 60 ° C for 8 hours. Then, unreacted monomers were removed by an evaporator, and at the same time, the mixture was concentrated to a nonvolatile content of 50% by weight to obtain a copolymer rubber latex.

On the other hand, in an autoclave equipped with a stirrer, 30 parts by weight of ethylene-acrylic acid copolymer resin (acrylic acid content: 20% by weight, melt index: 30 O dg / min), 3 parts by weight of aqueous ammonia, 67 parts by weight of water The mixture was heated to 95 ° C. while stirring, and further heated at 95 to 98 ° C. for 1 hour. Then, the mixture was cooled to room temperature with stirring to obtain an ethylene-acrylic acid copolymer resin emulsion.

The copolymer rubber latex and copolymer resin emulsion obtained as described above were mixed at a resin weight ratio of 1: 1 to prepare an adhesive.

Manufacture of composite metal sheets (Example 1)

The adhesive thus obtained was applied to a 0.6-thick cold-rolled steel sheet so as to have a dry film pressure of 2δ ^, and kept in a drying oven at 80 ° C for 5 minutes. The water was dried. Next, the adhesive-coated surfaces were brought together, fed by a heating roll so that the temperature of the adhesive layer became 160 ° C., and the speed was adjusted to perform heat-press bonding. Table 1 shows the results of measuring the adhesiveness, vibration damping properties, and workability of the obtained composite steel sheet.

(Example 2)

The adhesive was applied on a Teflon plate so as to have a dry film thickness of 50 ^, and kept in a drying oven at 80 ° C for 5 minutes to dry the water. Next, the adhesive film was peeled off from the teflon plate, sandwiched between 0.6 mm thick cold-rolled steel sheets, fed by a heating roll so that the adhesive temperature became 160 ° C, and the heating speed was adjusted. Crimped. Table 1 shows the physical properties of the obtained composite steel sheet.

(Example 3)

In place of the cold-rolled steel sheet in Example 1, Then, a composite metal sheet was produced in the same manner as in Example 1 except that a cold rolled 0.6-roll steel sheet was used, which was coated with a solution to a dry film thickness of 1 mm and air-dried. Table 1 shows the results of various physical property tests of this composite metal sheet.

(Example 4)

Instead of using the cold-rolled steel sheet of Example 2, a 0.6-thick cold-rolled steel sheet, which was previously coated with a copolymer resin emulsion to a dry film thickness of 1 and air-dried, was used. A composite metal plate was manufactured in the same manner as in 2. Table 1 shows the results of various physical property tests of this composite metal sheet.

(Example 5)

Instead of the adhesive film of Example 2, a composite film was used in which a copolymer resin emulsion was applied to both surfaces of the adhesive film of Example 2 by a spray coater so as to have a dry film thickness of 1, and air-dried. Except for the above, a composite metal plate was manufactured in the same manner as in Example 2. Table 1 shows the results of various physical property tests of the obtained composite metal sheet.

(Example 6)

Instead of the cold-rolled steel sheet of Example 3, an aluminum sheet (Example 6) Each composite metal plate was manufactured in the same manner as in Example 3 except that a lead-plated steel plate (Example I) and a stainless steel plate (Example 8 :) were used, and the results of measuring the adhesiveness and workability were shown in the table. Shown in 1.

(Examples 9 and 10)

Example 3 was replaced by Example 3 except that the cold-rolled steel sheet having a thickness of 1.6 mm (Example 9) and 3.2 (Example 10) were used instead of the cold-rolled steel sheet having a thickness of 0.6. Each composite metal plate was manufactured in the same manner, and the results of measuring the adhesiveness and workability are shown in Table 1.

(Comparative Example 1)

Table 1 shows the results of measuring the vibration damping properties and workability of commercially available vibration-damping steel sheets for washing machines (using an organic solvent-based adhesive, with a film thickness of 50).

Test method for adhesion, vibration damping and workability

The adhesiveness was measured according to T-peel adhesive strength (JI SK6854) and tensile shear adhesive strength (JI SK68 δ0). In particular, for the latter, the test piece shown in Fig. 4 was prepared and measured to make the test piece thickness 1.6 mm.

Vibration damping is measured using a complex elasticity coefficient 7} measuring device manufactured by Brüel & Kjær. Then, the loss coefficients of the composite metal plate at 40 ° C and 80 ° C at 200 Hz were measured.

The workability was determined by performing 90 ° bending at the center of the test plate and measuring the average [(1 1 + 1 ₂ ) no 2] of the edge displacement (see Fig. 5).

Example Example Comparative Example

2 3 4 5 6 7 8 9 10 1 Removal r Peeling off? 2 18 18 18 18 30 1.8 12 I Strength ^: (kg / 25 mm) i

1Ί ·: j | Tension shearing 200 80 220, Z 220 220 220 Δ 0 ^l Λ \ (UΛ o Z Π Ό O 2 O 0 220 150 I Strength ′ (kgZcm ² )

Damping coefficient (40 '(C) | 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 u

Eve coefficient (80 ° C) | 0. \ 0 10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.06 Addition: gender (deviation, mm) I 0 0 0 0 0 0 0 0 0 0 0

From the results of the tensile shear and T-peel adhesion shown in Table 1, the vibration-damping metal plate of the present invention (Examples 1 to 5) is superior to the commercially available solvent-based adhesive (Comparative Example 1) in adhesion. I understand. As a result, as shown in Table 1, it became possible to produce thick laminated steel sheets with good workability (Example 7). Also, it can be seen that the vibration damping property is better than that of the commercially available solvent system (Comparative Example 1) in a wide temperature range of 40 to 80 ° C. Further, as shown in Table 1, the adhesive of the present invention also has excellent adhesion to aluminum plate (Example 6), zinc plated steel plate (Example Ί) and stainless steel plate (Example 8). It is also possible to create a laminated plate of different types.

The invention's effect

The vibration-damping composite metal sheet of the present invention has excellent adhesion between metal sheets, so it can withstand complicated processing and can also produce a thick vibration-damping steel sheet. In addition, it has good vibration damping properties in the range from normal temperature to high temperature, and because the adhesive is a water-dispersing system, it does not generate harmful organic solvents during the manufacturing process. Also, it is easy to control the adhesive film thickness to around 50.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows a cross-sectional view of a damping composite metal plate.

FIG. 2 shows a cross-sectional view of another embodiment of the damping composite metal plate.

FIG. 3 shows a cross-sectional view of still another embodiment of the damping composite metal plate.

FIG. 4 shows a cross-sectional view of the tensile shear adhesive strength test piece.

Fig. 5 shows that when the 90 ° bending process is performed, the deviation of the end is 1! 1 and ₂ show cross-sectional views of the test plate.

Claims

The scope of the claims

1. In a vibration-damping composite metal plate having an adhesive layer between metal plates, the adhesive is composed of (A) an ethylenically unsaturated carboxylic acid-butadiene copolymer rubber and (B) a carboxyl group-containing rubber. A vibration-damping composite metal plate, which is a latex composition containing an olefin copolymer resin.

2. The vibration-damping composite metal plate according to claim 1, having a structure further comprising the olefin copolymer resin (B) layer on one or both surfaces of the adhesive layer.

3. The method for producing a vibration-damping composite metal plate according to claim 1, wherein the adhesive is applied to one or both metal plates, dried, and then heated and pressed.

4. It is manufactured by sandwiching a dry film of the adhesive or a composite film in which one or both surfaces of the dry film of the adhesive are coated with the olefin copolymer resin (B) between metal plates and heating and pressing. A method for producing the vibration-damping composite metal sheet according to claim 1 or 2.

5. The method according to claim 3, wherein at least one of the metal plates has a bonding surface coated in advance with the olefin copolymer resin (B).

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