US3902421A

US3902421A - Method for forming a picture image

Info

Publication number: US3902421A
Application number: US483588A
Authority: US
Inventors: Isoji Takahashi
Original assignee: Rank Xerox Ltd
Current assignee: Xerox Ltd
Priority date: 1973-06-08
Filing date: 1974-06-27
Publication date: 1975-09-02
Anticipated expiration: 1992-09-02
Also published as: JPS5063930A

Abstract

A process for forming a picture image employing a transfer material which retains a powder image and an image receiving member. The two members are brought into close contact with each other to effect transfer of the powder image by means of electrostatic force. Magnetic materials are employed in or on the back sides of the transfer member and the image receiving member creating a magnetic attractive force between the magnetic materials so as to bring the powder image surface of the transfer member into close contact with the image receiving member resulting in an effective transfer of the powder image.

Description

United States Patent n91 Takahashi 1 1 Sept. 2, 1975 [21] App1.N0.:483,588

130] Foreign Application Priority Data June 8, 1973 Japan 48-64518 156] References Cited UNiTED STATES PATENTS 3.299.809 1/1967 .iavorik ct a1. 101/426 3.306.198 2/1967 Rarcy t 101/426 3.443.515 5/1969 Smith c1. :11 101/D1G. 13

3.559.570 2/1971 Martel et a1. 101/426 X 3.561.358 2/1971 Wcigi 101/170 3.638.567 2/1972 Waikup 101/401.1 X 3.687.072 8/1972 Pym 101/170 X 3.721.553 3/1973 Giaimo. Jr.. 355/17 X 3.765.330 10/1973 Gundiach 101/426 3.801.315 4/1974 Gundiach et a1.. 96/1.4 3.849.161 11/1974 Klaenhammer 117/17.5

Primary Eraminer-E. H. Eickhoit [57] ABSTRACT A process for forming a picture image employing a transfer material which retains a powder image and an image receiving member. The two members are brought into close contact with each other to effect transfer of the powder image by means of electrostatic force. Magnetic materials are employed in or on the back sides of the transfer member and the image receiving member creating a magnetic attractive force between the magnetic materials so as to bring the powder image surface of the transfer member into close contact with the image receiving member resulting in an effective transfer of the powder image.

6 Claims, 9 Drawing Figures PATEH'I'EUSEP' 2:915

FIG.

1 111111 IIIIIIIIJIIII 11111111 11111111111 FIG.

1 METHOD FOR FORMING A PlCTURE IMAGE BACKGROUND OF THE INVENTION This invention relates to a method for forming a picture image and more particularly to a method of obtaining a transfer picture image.

Previous methods practiced in the prior art to transfer images include contact transfer processes wherein a transfer material is brought into close contact with an image receiving material for transferring a picture image to the latter. In order to obtain a picture image of sufficiently good quality employing this contact copying process, an original picture on a transfer material and a surface of an image receiving material must be brought into close and uniform contact with one another. With this view in mind achieving uniform intimate contact has been attempted between these members employing mechanical pressure, a vaccum force and electrostatic forces which are conventionally resorted to.

Mechanical pressure can be obtained with relative ease to supply uniform layer or point contact but it is not convenient for the purpose of bringing surfaces into closing uniform contact by reason of the difficulties in applying uniform pressure to a plane. Vaccum forces when applied invariably results in an increased size of the apparatus and complexity of its construction producing other noticeable and substantial disadvantages. When employing electrostatic force it is desirable that the apparatus for achieving surface contact may be made small in size and simple in construction. However, this method is in employed for a contact copying process, wherein difficulties are encountered in transferring a toner electrostatically retained on a transfer medium to an image receiving material surface forming a picture image since an electric field several to several tens of times greater than that conventionally employed for producing an electrostatic force is required in order to retain the toner for producing an electrostatic force to bring the two materials into sufficiently close contact with one another. Due to this strong electric field that is required. the toner is transferred to the image receiving material prematurely before close contact is achieved.

There is therefore, a demonstrated continuing need for improved methods of imaged transfer from an image retaining member or transfer member to an image receiving member.

it is, therefore. an object of this invention to provide a method which is devoid of the above noted deflencies.

It is a further object of this invention to provide a novel image transfer process.

Another object of this invention is to provide a novel transfer copying process which employs a transfer material employing both conductive and non-conductive surfaces in order to provide both a toner image and a means to tranfer the toner imageto an image receiving member.

It is a further obje ctof this'invention to provide a method which results in sufficiently good quality in contact copying processes by allowing an original picture image on a transfer member and a surface of an image receiving member to be brought into close and uniform contact one with the other.

These and other objects are accomplished generally speaking by providing a process for forming an image wherein a transfer member retaining a powder image thereon and an image receiving member are brought into close contact with each other for effecting transfer of the powder image by means of electrostatic force. Magnetic material is provided in or on the back sides of the transfer material and the image receiving member creating a magnetic attractive force between the magnetic materials thus bringing the powder image carrying surface of the transfer member into close contact with the image receiving member surface so that the powder image may be transferred by electrostatic attraction.

This novel transfer copying process employs a transfer material comprising a nonconductive substrate and a conductive layer provided on one surface thereof which process comprises removing the conductive layer in an imagewise pattern thereby exposing the nonconductive image areas, and powder in the resulting group portions to form an original picture image and transferring the material image to an image receiving member by electric or other suitable means to form a transferred picture image. More specifically a method for forming a picture image is provided wherein a transfer member retaining a powder image thereon and an image receiving member are brought into close contact with each other for transferring the powder image onto the image receiving member by means of electrostatic force. The method comprises uniformly dispersing magnetized material in at least either of the transferring member or the image receiving member for cooperation with another magnetic material in the other member to effect close contact of the powder image retaining surface and a transfer material so as to result in transfer of the powder image by electrostatically applied force.

The transfer member may be comprised of any suitable nonconductive material. Typical nonconductive materials include resin films, such as polyethlyene. polyvinylchloride, polystyrene. polyester, polyvinylidencchloride and paper impregnated with silicone, an alkyd phenol resin or an epoxy resin for insulation purposes. Substrates employed should desirably have a resistance of over 10 ohms/cm.

The transfer member may be comprised of any suitable conductive layer. Typical conductive layers include, resins which contain disperse conductive particles, a vapor evaporated metal film. a plated metal film membrane, a conductive resin or the like all of which are easily removable. Easily removable for the purposes of the present invention is defined as locally removably by means of a steel pen, a writing device for scribe-recording and the like. The conductive layer employed should desirably have a resistance of less than 10' ohm/cm.

Any suitable image receiving material may be employed in the process of the instant invention. Typical image receiving materials include, cooper plate, iron plate, zine eoatediron plate, and tin coated iron plate. A thinnon-magnetic material lined with a strong magnetic material may also be employed as the image receiving material.

Any suitable toner may be employed in the process of the instant invention. It is preferable that a toner with a particle size and a range of 3-30 microns be conveniently employed for use in copying. At the same time the maxium number of powder layers embedded in a groove portion of the original picture image may be expressed as (a depth ofthe groove a particle diameter of charged powder). Based on the assumption that a transfer I" eiency of 8090% is required to achieve a sufficient density which depends on developed mass and transfer efficiency not transfer efficiency alone, of a transferred image it may be concluded that a required number of powder layers in the groove portion is over 3-5. For these considerations a desirable depth of the groove may be calculated to be over l microns. Of course a groove depth depends on the color and the condition of the surface and the color of the toner.

Any suitable magnetic material may be employed in the process of the instant invention. Typical magnetic materials include strongly magnetic material powder dispersed in a resin binder including barium ferrite, cobalt ferrite, nickel ferrite among others. Any suitable resin binder may be employed in the process of the instant invention in connection with the magnetic particles described above. Typical binders include, acrylic- .20 the instant inventionwherem'an imaged receiving resin, alkyd resin, butadiene-acrylonitn'le rubber, butadiene-styrenc rubber, natural rubber, silicon rubber, ABS resin, and styrene resin.

A contact plate containing a magnetized magnetic material may be placed on the image receiving member. A strong magnetic attraction occurs between the contact plate and the image receiving member, the transfer member being disposed there between this achieving close intimate contactbetween the transfer member and the image receiving member. Any suitable contact plate as described above may be employed in the process of the instant invention. Normally a magnetic material magnetized to holding a force of over I gm/cm or desirably gm/cm is employed in one of the following arrangements:

l. the contact plate is nonconductive in its entirety;

2. the contact plate has a multiple-layer structure with a conductive and nonconductive layers; or

3. the contact plate is conductive in its entirety.

Where the contact plate is of type 2 it suffices if either a nonconductive layer or a conductive layer comprises a magnetized material. Of course, both layers may include a magnetized material. When the contact plate is of either of type I or 2 the corona charging device applies a corona ion having the same polarity as the toner onto the back surface of the contact plate to transfer the toner image onto the grounded image receiving material. When the construction of the plate is of either of type l or 2 the nonconductive portion thereof should desirably have a surface and a volume resistance over l0 ohms. This is to preclude leaking of the charge through the nonconductive portion.

If the nonconductive portion is exccssively'thick, its electrostatic capacity contributes to diminishing the electric field which serves to transfer the toner image deposited in the portion of the transfer member onto the image receiving member thus yielding an undesirable result. Thus, it is found that the thickness of the nonconducting portion is desirably to be kept under 5 mm. When the contact plate is of

type

2 or 3 its conductive portion may be electrically floated while applying corona ion by a corona charging device on the contact plate from above to achieve relocation of the toner image on the image receiving member. In the event the construction of the Contact plate is of

type

2 or 3 furthermore. a voltage may also be applied between the conductive portion tltcreofztnd the image re- 5 stant invention will be more readily understood with reference to the following drawings of which:

FIG. I illustrates an example of an transfer material for use in the process of the instant invention.

FIG. 2a illustrates a transfer material of FIG. I with a conductive layer removed in an imagewise pattern.

FIG. 2b illustrates the member of 2a placed onto a grounded substrate with corona charging supplied.

FIG. 2c illustrates the member of 2b with toner applied.

In FIG. 2d is seen the image receiving member of FIG. 2c placed on an image receiving member containing a highly magnetic material with a contact plate placed behind the imaged transfer member.

In FIG. 3 there is illustrated another embodiment of member possesses a curvature.

In FIG. 4 still another embodiment of the instant invention is illustrated which includes a transfer member for use in the present invention comprising a support which is flexible and di-electric in nature, an exfoliating layer provided on the support. and an easily removable conductive layer provided on the exfoliating layer.

In FIG. 5 there is seen another embodiment of a transfer member comprising a support an easily removable conductive layer provided on a front surface of the support and a magnetized magnetic material layer provided on the back surface of the support.

In FIG. 6 there is seen another embodiment of the instant invention wherein a magnetic body which is provided substantially evenly onto a back surface of a supporting body of a transfer member in form of islands, stripes or a grill pattern is provided.

In FIG. 1 is shown one embodiment of a transfer member for use in the process of the instant invention.

Number 1 denotes a transfer material comprising a conductive layer IS removed in an imagewise pattern.

plastic and nonconductive substrate to having an easily removable conductive layer 3 provided thereon. The conductive layer 3 is made of a resin which contains dispersed conductive particles, as described above.

In FIG. 2a is seen the transfer member 1 of FIG. I with the conductive layer 3 removed in an imagewise pattern by means of a steelpen, a writing device for scribe-recording and the like. 4 denotes a picture image region at which the nonconductive supporting body surface is exposed by the removal of the conductive layer. Thus. the transfer member 1 is given both the ability to retain a picture image information and the ability to transmit or transfer the information. This portion from which conductivity is removed is an imagewise pattern, may be made conductive again by covering same with, for instance, a conductive ink, thus facilitating correction or modification.

In FIG. 2b, as seen. the supporting body 2 which is placed on a grounded-substrate plate 5, and corona charging is effected from the side of the conductive layer 3. In the FIG. 6 denotes a corona charger 7 a high voltage source for supplying a high voltage to the corona charger 6, and 8 a charge deposited on the nonconductive surface of an exposed portion 4 where the Here. the conductive layer 3 may be grounded simultaneously with or subsequent to the charging. In neither case is the charge retained on the conductive layer 3.

ln FIG. 2c a powder material hereinafter referred to as toner, having a charge opposite in polarity to that of the charge 8 is supplied onto the picture image region 4 having the charge 8 thereon, thereby carrying out development. The toner is deposited only in the picture image region 4 due to electrostatic force, forming an image 9. Any of conventional elcctrophotographic dry developing methods including cascade method, powder cloud method, magnetic brush method, and fur bush method may be used for the purpose of developing. Transfer member 1 having the toner image 9 formed thereon is placed onto an image receiving material 10 containing a highly magnetic materiai, in such a manner that the toner image is in contact with the image receiving, as shown particularly in FIG. 2d. Suitable materials for use as the image receiving member 10 are described above. A strong magnetic attraction occurs between the contact plate 11 and the image receiving material 10 the transfer member 1 being disposed and held between the contact plate and the image receiving material to achieve close intimate contact between the transfer member and the image receiving member 10. 7 denotes a high DC voltage source, and 12 a charge applied onto the back surface of the contact plate 11.

In FIG. 3 is illustrated still another embodiment of the instant invention wherein an image receiving member possesses a curvature. Number 10 denotes an image receiving member comprising a strong magnetic layer with curvature in the form of a cylindrical shape. A transfer material 1 carrying a charged powder image 9 on picture image portions thereof is placed onto an image receiving material 10 in such a manner that the side of the conductive layer 3 of the transfer material 1 is brought into face-to-face contact with the image receiving material 10. On the transfer member 1 furthermore there is superimposed a contact plate 11 comprising a flexible magnetized strongly magnetic material. The contact plate 11 by means of a strong magnetic attractive force causes the transfer material 1 to sit intimately over the image receiving material 10 along the curved surface thereof achieving good contact between the transfer material 1 and image receiving member 10.

ln FIG. 4 still another illustration of the transfer member for use in the present invention. A transfer member 1 comprises a support 2 which is flexible and dielectric in nature, an exfoliating layer 14 provided under support 2 and an easily removable conductive layer 3 provided on the exfoliating layer 14. This embodiment has the advantage in that a grooved picture image can be obtained without making the conductive layer 3 very thick. This embodiment illustrates a transfer member for transferring a powder image as used in the methods of this invention particularly shown in FIGS. 2-4. Materials for use in the support 2 in the conductive layer 3 are the same as hereinbefore described. The image receiving member as illustrated in theform of cylindrical shape. It shouldbe apparent-however,

that the shape equally may be columnar, spherical, wavy, orthe like. When the image receiving'mernber is a spherical, mountainlike or conical form with a radius of extremely small'curvature, however, it'isnecessary that the transfer member and the contact plate are also formed into a shape corresponding to that of the image receiving member. Materials for use as the transfer material l0 and the contact plate 11 are the same as those used in the case shown in M05. 2 except that the contact plate 11 must be of a flexible material in this embodiment.

In FIG. 5 a transfer material 1 comprising a support 2 an easily removable conductive layer 3 provided on the front surface of the support 2 and a magnetized magnetic material layer 15 provided on a back surface of the support 2 is seen. The magnetic material layer is comprised of strongly magnetic material powder dispersed in a resin binder.

In FIG. 6 is seen a magnetic body 16 which is provided substantially evenly onto a back surface of a support 2 of a transfer material I in the form of island stripes or a grill pattern. This magnetic layer 16 may be formed, for instance, by applying an ink-like solution of magnetic powder and a resin binder, which are dissolved in a solvent, by means of a gravure method. The magnetic layer 16 may be formed by any desired conventional method.

To further define the specifics of the present invention the following examples are intended to illustrate and not limit the particulars of the present system. Parts and percentages are by weight unless otherwise specified.

EXAMPLE I Styresol No. 4250. a styrenatcd alkyd resin 1 part by weight carbon black 4 parts by weight Toluene 8 parts by weight Employing a steel pen, the conductive layer of the transfer member is removed to expose a nonconductive surface in an imagewise pattern. The transfer member is placed onto a grounded conductive substrate plate in such a manner that the film support of the transfer member is superposed on the substrate plate. The conductive layer is grounded and is charged by a corona charging device to which a DC voltage of +5 kv is imposed. The charge is retained at picture image regions. namely, at the regions where the nonconductive film support surface is exposed. At the nonpieture image regions, that is, at the conductive layer, the charge is leaked out to the ground, thereby forming a charged image corresponding to the pattern of the picture image region. The conductive layer side of the transfer member is subsequently developed by a cascade developer with'negatively charged toner. Toner is deposited at the region of the charged image thus forming a toner image.' The transfer member is placed onto an image receiving inember comprising a grounded iron plate of 0 thicknessgin such a manner that the toner image urf a'ce,- t hat is, the'conductive layer side, of the transfer rnem ber is heldin face to-face contact 'withthe iron plate.) furthermore} a magnetized rubber magnet sheet of 0.8 mm thickness having a coercive force of l3g/cm is placed over the transfer member. The transfer member is sandwiched between this rubber magnet sheet. and the iron plate. This rubber magnet sheet possesses EXAMPLE ll A contact plate is employed having the same rubber magnet as described in Example I on one surface of which is adhered a 20 micron thick aluminum foil by means of an epoxy-base adhesive. A mm-thick iron plate is used as an image receiving member as in Example l onto which an iron plate is placed on the transfer material in such a manner that a toner image surface,

that is a conductive surface, of the transfer member is broughlllmolfacriil'fabcf 9 f i n. Pi

groundedto remove the charge deposited thereon. The Funhermorev tm'transf" manna Pl t e. recording material is then subjected to transfer and fixcontact plate with the aluminum surface thereof being held in face-to-face contact with the former. A DC voltage of l kv is then imposed between the aluminum layer of the contact plate and the iron plate. As a result, the toner image is successfully transferred onto the iron plate surface.

EXAMPLE [ii A triacetylcellulose film of 100 micron thickness is used as an image receiving member. This film is onto an iron plate of 10 mm thickness, on which film is placed a transfer member in the same manner as in Example l. Furthermore, a rubber magent sheet is superposed on the transfer member to bring the transfer member into close contact with the image receiving material by means of a magnetic force. Corona charging is carried out in the same manner as in Example l to obtain a good picture image of the triacetycellulose film EXAMPLE IV A triacetylcellulose film of 50 micron thickness is used as support, which film is coated with a dispersion of the following composition to form a conductive layer of micron dry thickness.

carbon black parts by weight nitrocellulose 3 parts by weight cuter oil I part by weight alcohol I50 parts by weight ethyl ether 200 parts by weight acetone IO parts by weight material is used in Example I is superposed on the transfer material, and corona charge is applied thereover. Consequently, the toner image is successfully transferred onto the steel plate and furthermore, the resultant toner image is not disturbed. This transferred toner image is fixed in the same manner as in Example 1.

EXAMPLE V Epoxy resin powder having an average particle size of 5 microns is dispersed substantially evenly over a conductive layer side surface of a transfer member carrying thereon the same picture image as in Example IV. The powder on the conductive layer surface is removed by a doctor blade, leaving the powder embedded in the grooved picture image portions only. This recording material is placed onto a grounded conductive substrate plate, to which recording material is applied from the conductive layer side thereof and a corona charge by a conventional corona charging device is imposed at a voltage of '5 -ltv. The conductive layer is then ation in the same manner as in Example lV. In the case of this Example, the resultant powder image is not disturbed.

EXAMPLE Vl The same kind of a transfer member as in Example V is subjected to removal of a conductive layer in a picture image pattern in the same manner as in Example V. After charging and developing with toner the transfer material member is placed onto a grounded image receiving member in the form of a tin-plated iron cylinder having a radius of 8cm in such a manner that the powder image surface, that is, the conductive layer surface, of the transfer member is held in face-to-face contact with the image receiving member. Furthermore. a flexible contact plate, similar to that of Exampie 1 is suspended over the transfer material in such a manner as to ensure the plate to fit intimately over the circumferential surface of said cylinder in order to achieve good contact with each other. By means of a corona charger operating at a high voltage of l0 kv. a charge is applied substantially uniformly over the contact plate. When the contact plate and the transfer member are separated from the cylinder, the powder image is successfully transferred onto the circumferential surface of the cylinder.

EXAMPLE Vll barium stesrate 80 parts by weight nitrocellulose parts by weight ethyl cellulose 30 parts by wei ht acetone 700 parts by wcighl methyl ethyl ketone I50 parts by weight methanol 200 parts b weight The scribe layer has a resistance of over IO Qhm/cm, and is thus nonconductive. For a conductive layer, a

l( dispersion solution having a composition similar to the g ming min I E; conductive layer of the transfer material of Example I toluene 100 parts by weight is applied to the scribe layer to a dry layer thickness of a roximately 3 microns. When the conductive layer Afier the conductive layer of the transfer member IS side of the transfer member is scratched in an imaged femOWd n n g P a ium ferrite p pattern employing a steel pen, the conductive layer and f in the magnetic material layer is magnetized by an the scribe layer are removed from the support and the electromagnet- Electric charging and Powder psupport surface is exposed to form a grooved picture 10 ing are then carried 0min 111: me manneras in Examimage region. As in Examples IV and V, the position of l l and subsaiuemly lhc recording material is Placed the transfer member is properly adjusted to that of an onto a shot'blasmd lo mm'thick P The image mceiving member and then a Contact plate is cording material is brought into intimate contact with perposed thereon f carrying out the t f with a the steel plate surface, followed by corona charging for good resulting piciure image empioying iechniques transfer, as a result of which a powder image is trans- Scribeci ferred onto the image receiving material to form a good image thereon. When the above process is repeated EXAMPLE Vm employing a cylindrical image receiving member, simi- A mixture of the following composition is used to effeftwely good coma obtamed and a Powder form a scribe layer to a dry thickness of 20 microns. successfully EXAMPLE xn A conductive layer having the same composition as Zinc 75 P by B in Example IV is applied onto a commercially available 120 b ht {:23 0.8 mm-thrck rubber magnet sheet. The dry thickness methyl acetate 200 parts by weight of the layer formed is approximately 25 microns. The f f gg f igg 5:: E; resulting transfer member is subjected to picture image fonning, charging powder developing and transferring 30 with good contact with a cylindrical image receiving During, drying brushing takes place as in Example VII m l f a f f transfer and a suitable layer for scribing is obtained. Onto the v Fchmques prev'ously puflmes m Example scribe layer, a mixture of 80 parts by weightofpolyvii I EXAMPLE XII nyl potassium benzenesulfonate a nd 20 p arts bywergh ,i f of silica gel,.whi ch has been dissolved n y se 'd it v F? i i FQ PF- ing a small mama-seawater, isa p piied to'formrQr h.' E 'S"=. 'F fi1"}:?P a conduetivelayer Thedry hernias: the-Carma layervwhlchw obwmfd by mhaxmg a layer is approximately 2 microns. The layer possesses y mlckness of aboin so q i and compnsmg a a resistance of approximately 10' ohm/cm. Also, both mixture of followmg composmon I prepared:

the scribe layer and the conductive layer are translucent. This facilitates easy positioning of the transfer cube black 30 Pam by Wish, member and the image receiving member when the ft 'f i Powder 8 P gy is? e I'll OCC UOSC a I transfer is carried out by the methods of Examples VI cam, on 2 E 5325 or V. Consequently a good transferred image is formed fligloil olhe 300 ans by weight e y et r 500 parts by wei ht on the image receiving member. acetone par by weight EXAMPLE IX This conductive layer possesses a resistance of ap- A transfer member rs prepared in the same manner proximately os Ohm/cm and is easily removabie by as pi excePt f 5 P by weight of 50 means of a steel pen. Using the conductive layer, fur- Rose Bengal is added to the mixture of Example VII. As then-non a good transferred image is obtained as in a result. a non-picture image portion of this Example ample x Magnetized magnetic fil is i d on h becomes pink-tinted translucent, while the picture entire f it i also possible employing i process S P f f f fp making "Possiblc to distribute the magnetic materials substantially to clearly dlstmgulsh the Picture Image FfQ The evenly over the back surface of the support in the form transfer member and the contact plate are independent r isiand' stripe gi-ili patiem This is f d to f ilmembers. It IS possible to integrally combine the transirate easy positioning of the transfer member and an ffil' material with 11 plate and the transfer material image rgceiving member when the magnetic material is liSCIf IS a magnetized material, the contact plate beopaque provided the support and the conductive layer comes unnecessary. are transparent OI translucent.

EXAMPLE X EXAMPLE XIII A transfer member is prepared by f r g a g- Onto the back surface of the support of a transfer netic material layer of the following composition on the member as shown or as described in Example VIII magsupport side of a transfer member similar to that used tie ink of th following com i i i a li d i a in Example I so that a dry thickness of a magnetic layer substantially evenly dispersed island pattern by gravure of 50 microns is provided: printing:

I parts by weight 40 parts by weight l0 parts by weight 60 parts by weight barium ferrite powder a slyrcnated alkyd resin linseed oil toluene EXAMPLE XIV A transfer member comprising a l00 micron thick polyethylene terephtalate resin film and a vaccumva or-evaporation-applied aluminum layer of approximately 1,000 A is provided on one surface of the resin film, onto which aluminum surface is formed a nonconductive picture image by resin ink of the following composition:

styrenated alkyd resin toluene l part by weight parts by weight After drying at room temperature the aluminum surface is grounded. Electric charge is applied by a corona charger to which is imposed a DC voltage of +5 kv. thereby depositing positive corona ion on said picture image. The picture image is subsequently developed by a conventional cascade developing system with negatively charged toner to form a toner image on said picture image. The transfer material is then placed onto an image receiving member of a mm thick iron plate in such a manner that the toner image surface of the transfer member is held in face-to-face contact with the iron plate. The same kind of rubber magnet as employed in Example I is furthermore superposed on the transfer member. Corona charging is effected from the rubber magnet side in the same manner as in Example I. As a result", the toner image is successfully transferred onto the iron plate which serves as an image receiving member.

. i-s MrLax Onto a resin surface of a transfer member employed in Example XlV a magnetic material layer as employed in Example X is applied which magnetic layer is then magnetized by means of an electromagnet. Employing a resin ink as in Example XlV a nonconductive picture image is formed on the aluminum surface and dried to room temperature. Charging and developing steps are carried out as in Example XIV to deposit a toner image on said picture image. The toner image surface is placed in face-to-face contact with a 10mm thick shotblasted steel plate which comprises the image receiving member resulting in satisfactorily intimate contact therebetween. A corona charging is then carried out to effect image transfer in the same manner as in Example I. Consequently, thetoner image is successfully transferred onto the steel plate serving as the image receiving mcmbcr.

EXAMPLE XVl A 1mm thick tin-plated steel sheet is having formed thereon a nonconductive picture image in the same 5 manner as in Example XIV as provided. After charging and developing, a toner image is formed onto the picture image. An image receiving member of 100 micron thick triacetylcellulose film is placed onto the steel sheet surface. Over the image receiving film a rubber magnetic sheet is placed as in Example I. The steel sheet is subsequently grounded, and corona charge is applied for image transfer from the rubber magnetic sheet side by a corona charger to which is imposed a DC voltage of 8 kv. As a result the toner image is successfullytransferred onto the image receiving member.

Although the present examples were specific in terms of conditions and materials used, any of the above listed typical materials may be substituted when suitable in the above examples with similar results. In addition to the steps used to carry out the process of the present invention, other steps may be employed, for example. the image may'be negatively charged in which case a charge powder of positive polarity is employed and similarly a corona charge is imposed by a positive voltage. Other materials may be employed for example powder for use in the method of the invention may be colorless or of any desired color. Further, the magnetized magnetic material may be well provided on both the transfer and image receiving members so that they attract each other.

Anyone skilled in the art will have other modifications occur to him based on the teachings of the present invention. These modifications are intended to be encompassed within the scope of this invention.

What is claimed is:

l. A transfer copying process comprising providing a transfer member comprising a nonconductive substrate and a conductive layer provided on-one surface thereof, removing said conductive layer in an imagewise pattern thereby exposing grooved nonconductive image areas, enbedding toner in said grooved portions to produce an original picture image and transferring the original image to an image receiving member said transferring step comprising applying an electrostatic force between said image transfer memberand-s,aid image receiving member, uniformly dispersing magneatleastpne of said tra nsferceiving member.

2. The process as defined in claim 1 wherein said transfer member comprises a nonconductive substrate and an easily removable conductive layer.

3 The process as defined in claim 2 wherein said nonconductive substrate is selected from a group con sisting of polyethylene, polyvinylchloride, polystyrene, polyester, polyvinylidenechloride, and paper impregnated with silicone.

4. The process as defined in claim 1 wherein the conductive layer of said transfermember is selected from the group consisting of conductive particles dispersed in a resin, a vapor evaporated metal film, a plated metal film membrane. and a conductive resin.

5. The process as defined in claim l wherein said image receiving member'comprises a material selected BHUZAZ] 13 14 from the group consisting of copper plate, iron plate ring member so that said transferring member is dis zinc coated iron plate. and tin plated iron plate. posed between said contact plate and said image re- 6. The process as defined in claim I wherein a mag ceiving member. netized contact plate is superposed over said transfer-

Claims

1. A transfer copying process comprising providing a transfer member comprising a nonconductive substrate and a conductive layer provided on one surface thereof, removing said conductive layer in an imagewise pattern thereby exposing grooved nonconductive image areas, enbedding toner in said grooved portions to produce an original picture image and transferring the original image to an image receiving member said transferring step comprising applying an electrostatic force between said image transfer member and said image receiving member, uniformly dispersing magnetized magnetic material in at least one of said transferring member or said image receiving member for cooperation with another magnetic material in the other member to effect close contact of a toner image retaining surface of the transfer member with the image receiving member.

3. The process as defined in claim 2 wherein said nonconductive substrate is selected from a group consisting of polyethylene, polyvinylchloride, polystyRene, polyester, polyvinylidenechloride, and paper impregnated with silicone.

4. The process as defined in claim 1 wherein the conductive layer of said transfer member is selected from the group consisting of conductive particles dispersed in a resin, a vapor evaporated metal film, a plated metal film membrane, and a conductive resin.

5. The process as defined in claim 1 wherein said image receiving member comprises a material selected from the group consisting of copper plate, iron plate, zinc coated iron plate, and tin plated iron plate.

6. The process as defined in claim 1 wherein a magnetized contact plate is superposed over said transferring member so that said transferring member is disposed between said contact plate and said image receiving member.