JP2761901B2 - Image transfer method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image transfer method for producing a color proof and the like.

[Conventional technology]

It is well known that a color sheet for color proofing (called a color proof) is used to save labor and time of proof printing performed as a pre-process of main printing in multicolor printing.

Several proposals have been made for the creation of this color proof, such as Japanese Patent Publication No. 47-27441.
No., JP-A-47-41830, JP-A-56-501217, JP-A-Showa-5
Nos. 9-97140, 60-28649 and U.S. Pat.
And the like.

In any case, the image forming sheet usually includes a step of superimposing an image sheet on which an image is formed and an image receiving sheet for receiving the image, and pressing or heating / pressing the image receiving sheet to transfer the image. I have. In the method of producing a color proof including this step, unlike the method of forming an image by exposing the photosensitive layer transferred onto the transfer paper, the formed image is sequentially transferred one color at a time. It is important that no deviation occurs between the images.

However, for example, when passing an image sheet and an image receiving sheet superimposed between a pair of rollers for transfer, the two sheets may be displaced from each other, and warpage or wrinkles may be generated. It was difficult.

Therefore, in Japanese Patent Application Laid-Open No. 60-255497, one sheet is sandwiched between a support such as a metal plate and a cover sheet.
Means for solving the above problem by passing between a pair of rollers are disclosed.

[Problems to be solved by the invention]

However, although the prior art described in the above-mentioned publication can certainly prevent the displacement between the transferred images to some extent, the displacement between the support and the sheet may occur, and the effect is not sufficient.

Accordingly, it is a primary object of the present invention to provide an image transfer apparatus capable of preventing a transfer image from being displaced due to wrinkling of an image and an image receiving sheet or a displacement between image sheets to a practically sufficient degree. It is to provide a method.

[Means for solving the problem]

The above object is to superimpose an image sheet on which an image is formed and an image receiving sheet for receiving the image, and, on the superimposed sheet, a rubber-containing layer and a rigid support, This can be solved by transferring the image by pressing between layers of the rolls or by pressing and heating in a state in which the layer containing is placed on the image receiving sheet side and in a superposed state.

[Specific configuration of the invention]

 Hereinafter, the present invention will be described in more detail.

First, the method of the present invention will be outlined with reference to FIG.
Is formed on an image receiving sheet 2 for receiving the image, and preferably, the image receiving sheet 2 is overlapped with a support 4 having a slip stopper layer 3 containing rubber. For example, a pair of rollers for pressurizing integrally or for pressing and heating together
It passes between 5,5.

Under such an embodiment, since the slip preventing layer 3 contains rubber, no slip occurs between the image receiving sheet 2 and the image receiving sheet 2, for example, so that the image receiving sheet 2 and the support 4 are integrated as a result. That is, the image receiving sheet 2 does not warp or wrinkle due to the rigidity of the support 4. As a result, when transferring the images of each color to the image receiving sheet, it is possible to prevent the transferred images from being displaced.

Here, the slip-preventing layer 3 may be formed into a film shape and simply superposed on the support 4 or may be completely bonded (for example, by a lamination method) using an adhesive or a primer. Further, a coating solution obtained by dissolving and dispersing a rubber-containing material for forming a slip prevention layer in a solvent may be applied on a support and dried.

The thickness of the slip-stopping layer is not limited as long as it does not hinder its thermal conductivity in order to conduct heat from the support at the time of heating, but it is preferably 0.1 to 300 μm.

The support is preferably made of a material having good thermal conductivity when heating is also performed during transfer, and a metal plate is generally suitable. In some cases, a plastic plate or the like may be used. As the thickness of the support, 10 μm to 5 mm, particularly 0.1 to
1.5 mm is preferred. Further, it is desirable that the support has rigidity as much as possible, since wrinkles and warpage can be prevented.

As a means for applying pressure or applying pressure and heating to transfer, 1
A typical example is to pass the above-mentioned overlapping material between a plurality of pairs of rollers in a pair or conveyance direction. When heating is performed, one or both of the pair of rollers may be a rotoroll. Further, a press method using a flat plate or the like may be used.

The applied pressure is preferably 0.5 to 100 kg / cm ² , particularly preferably about 5 to ²⁰ kg / cm ² , and the heating temperature is preferably 70 to 150 ° C, particularly preferably 80 to 130 ° C.

Further, the support having the slip prevention layer may be complicated in the process when obtaining a multicolor image, but the image sheet may be on the side, or both the image and the image receiving sheet may be on the side. . Further, the slip preventing layer according to the present invention may be combined with a support and a cover sheet made of a PET film or the like described in the above-mentioned publication, and transfer may be performed with a superimposed image / image receiving sheet interposed therebetween.

Now, the slip prevention layer in the present invention contains rubber,
In addition, this is a layer that utilizes this as a slip prevention effect. Natural rubber can be used as the rubber, but is preferably synthetic rubber.

As this synthetic rubber, styrene-butadiene rubber,
Butadiene rubber, isoprene rubber, chloroprene rubber,
Urethane rubber, polysulfide rubber, tetrafluoroethylene / propylene rubber, acrylic rubber, epichlorohydrin rubber, ethylene vinyl acetate rubber, 1,2-polybutadiene rubber, thermoplastic elastomer (for example, styrene, olefin, urethane, polyester) , Polyamide-based, fluorine-based), ethylene / propylene copolymer, ethylene / propylene / diene copolymer, nitrile / butadiene rubber, butyl rubber, fluorine rubber, polyethylene chlorosulfone, propylene oxide rubber, ethylene / acrylic rubber, norbornene rubber , Silicone rubber, etc., and silicone rubber is particularly preferred. This may be used in combination.

In the slip stopper layer, (a) a tackifying resin such as rosin, polyterpene, phenol resin, xylene resin, epoxy resin, and petroleum carbonized resin; (b) a plasticizer such as phthalic acid ester, phosphoric acid ester, and paraffin chloride; (C) Oil and fats such as animal fats and mineral oils may be added to adjust the adhesiveness to the sheet. Further, an anti-aging agent, a stabilizer, a filler, a coloring agent and the like may be added.

As the silicone rubber suitable as the rubber contained in the slip preventing layer, a silicone rubber containing a linear organic polysiloxane having the following repeating units and a molecular weight of several thousand to several hundred thousand is preferable.

Here, n is an integer of 2 or more, and R is an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkyl group, a vinyl group,
Preferred is an aryl group in which 60% or more of R is a methyl group.

The silicone rubber useful in the present invention is obtained by a condensation reaction of such a silicone base polymer with the following silicone crosslinking agent.

(1) R-SiOR ') (1) R-SiOAc) (1) R-SiON = CR' 2) 2 wherein R is the same meaning as R described above, R 'is a methyl group, an ethyl group And Ac is an acetyl group.

These silicone rubbers are also available as commercial products,
For example, there is "YS-3085" manufactured by Toshiba Silicone Co., Ltd.

Another useful silicone rubber is a reaction between the above-mentioned base polymer and an H-type silicone oil having the following repeating unit, or a silicone base polymer in which about 3% of R is a vinyl group. And the reaction between the H-type silicone oils.

(Wherein, R has the same meaning as R above, m is an integer of 2 or more, and n is an integer of 0 or 1 or more.) To obtain a silicone rubber by such a crosslinking reaction, In addition to the components of tin, zinc, cobalt,
An organic carboxylate of a metal such as lead, calcium, manganese or the like, for example, dibutyltin laurate, tin (II) octoate, cobalt naphthenate, or a catalyst such as chloroplatinic acid is added.

In order to improve the strength of the silicone rubber, a filler may be mixed. Silicone rubber pre-filled with filler is commercially available as silicone rubber stock or silicone rubber dispersion.If it is preferable to obtain a slip-resistant layer by a silicone rubber film by coating, use an RTV or LTV silicone rubber. Is preferably used. Thus, examples include “Syl Off 23”, “SRX-257”, and “SH 237” manufactured by Toray Silicone.
There is a silicone rubber version for paper coating.

It is preferable that the silicone rubber layer further contains a silane coupling agent in order to further improve the adhesion to the support.

Examples of the silane coupling agent include the following.

(A) H ₂ NCH ₂ CH ₂ NHCCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ (C) HS (CH ₂ ) ₃ Si (OCH ₃ ) ₃ (d) CH ₂ CHCHSi (OCOCH ₃ ) ₃ (F) CH ₂ CHCHSi (OCH ₂ CH ₃ ) ₃ (g) H ₂ NCH ₂ CH ₂ NH (CH ₂ ) ₃ Si (OCH ₃ ) ₂ (CH ₃ ) (h) Chlorsilane The image sheet according to the present invention is: It can be obtained by forming an image thereon using a colored image forming material provided with a colored image forming layer containing a photosensitive composition and a colorant on a support.

To obtain a multicolor image using the image sheet and the image receiving sheet, first, a first color image is formed on the first color image forming material, and at least the colored image is transferred to the image receiving sheet and the support is peeled off. I do. Further, after forming the second color colored image on the second color colored image forming material, while registering the second color register mark image formed thereby with the first color register image on the image receiving sheet, The second-color image is transferred onto the first-color image, and the support is peeled off to obtain a two-color image. Similarly, the colored images of the third color and the fourth color are transferred onto the image receiving sheet to obtain a multicolor image.
In some cases, the multicolor image is indirectly transferred onto another material to be transferred to obtain a multicolor image (hereinafter, referred to as an indirect transfer method).

This type of method is disclosed in JP-A-47-41830 and JP-A-59-9.
No. 7,140,60-28649 and U.S. Pat. No. 3,775,113.

Since the image of the image sheet is finally transferred to the image receiving sheet, in order to transfer the image to the image receiving sheet efficiently and to facilitate the peeling of the support after the image transfer, an appropriate repellent surface is applied to the support surface. It is preferable to perform a release treatment with an oily substance or to provide a release layer on the support.

As the oil-repellent substance, for example, a silicone resin, a fluorine resin or a fluorine-based surfactant can be used,
Examples of the release layer include, for example, alcohol-soluble polyamide, alcohol-soluble nylon, a partially esterified resin of a copolymer of styrene and maleic anhydride, and a blend of methoxymethylated nylon, polyvinyl acetate, polyacrylate, and poly (vinyl acetate). Methyl methacrylate and acrylate copolymer, polyvinyl chloride, copolymer of vinyl chloride and vinyl acetate, polyvinyl butyrate, cellulose acetate phthalate, methyl cellulose, ethyl cellulose, cellulose diacetate, cellulose triacetate, polyvinyl alcohol, butyl cellulose , Hydroxyethylcellulose, carboxymethylcellulose, cyanoethylcellulose, cellulose acetate, cellulose triacetate, cellulose acetate butyrate, hydroxypropylmethyl Cellulose phthalate, hydroxypropylmethyl cellulose hexahydrophthalate, or mixtures thereof can be used.

The thickness of the release layer is suitably in the range of 0.01 μm to 10 μm, and particularly preferably in the range of 0.1 μm to 5 μm.

As a support of the colored image-forming material for forming the image-receiving sheet used in the present invention, preferably a transparent support, a polyester film, particularly a biaxially stretched polyethylene terephthalate film is used in view of dimensional stability against water and heat. Although preferred, an acetate film, a polyvinyl chloride film, a polystyrene film, a polypropylene film, and a polyethylene film can also be used.

The colored image forming layer is to form a colored image by being removed imagewise by development following imagewise exposure.

The colored image forming layer may be a colored photosensitive layer containing both a coloring agent and a photosensitive composition, and the coloring agent layer and the photosensitive layer may be different. The order of the colorant layer, the photosensitive layer, and the colored photosensitive layer is not limited. Further, a heat-fusible layer (hereinafter, temporarily referred to as an intermediate heat-fusible layer) may be provided between the support and the colored image forming layer. The outermost layer of the colored image forming layer may be a layer that can be adhered to the image receiving sheet, or a heat fusible layer may be provided on the colored image forming layer.

Various materials have been known as the photosensitive composition, and commercially available products can be easily obtained.
The photosensitive composition used, when exposed to actinic rays, undergoes a chemical change in its molecular structure in a short time, changes its solubility in solvents, and when a certain solvent is applied. Includes all compounds such as monomers, prepolymers and polymers that dissolve and remove exposed or unexposed portions. Examples of the photosensitive composition that can be used include a photo-crosslinkable photosensitive composition represented by the esterification of polyvinyl alcohol with cinnamic acid. Resin-based, diazonium salts and condensates thereof are mixed with polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide and the like, and systems mixed with a binder such as a cyclized rubber using an aromatic azide compound as a photo-crosslinking agent, and the like. A photosensitive resin using photoradical polymerization or photoion polymerization can also be used. Further, as a so-called positive / positive type in which the solubility of an exposed portion is increased, there is a photo-soluble resin system represented by a combination of naphthoquinonediazide and a novolak resin.

Commercial products of such a photosensitive composition include "KPR", "KOR", "KMER" manufactured by Eastman Kodak Co., USA, and "AZ-340", "AZ-119", "AZ-" manufactured by Shipley, USA. 1350 "," TPR "and" Okaresist "manufactured by Tokyo Ohkasha," FPPR "manufactured by Fuji Pharmaceutical Co., Ltd., and all of them can be used.

In addition, a photo-soluble resin system containing a compound capable of generating an acid upon irradiation with actinic rays and a compound having at least one bond capable of lumping with the acid can also be used.

Quinonediazide compounds are useful as photosensitive compositions.

Specifically, 1,2-benzoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-4-
Manifonyl chloride, 1,2-naphthoquinonediazide
A compound obtained by condensing 6-sulfonyl chloride or 1,2-naphthoquinonediazide-6-sulfonyl chloride with a compound containing a hydroxyl group and / or an amino group is preferably used.

Examples of the hydroxyl group-containing compound include trihydroxybenzophenone, dihydroxyanthraquinone, bisphenol A, phenol novolak resin, resorcinol benzoaldehyde condensed resin, and pyrogallol acetone condensed resin. Examples of the amino group-containing compound include, for example, aniline, p-aminodiphenylamine, p-aminobenzophenone, 4,4'-diaminodiphenylamine, 4,4
-Diaminobenzophenone and the like.

With regard to quinonediazide compounds, including those described here, furthermore, J. KOSAR's “Light Sensitive System
m "(Wiley & Sons, New York, 1965) and Nagamatsu, Inui," Photosensitive Polymers "(Kodansha, 1977).

Dyes and pigments can be used as the coloring substance as the coloring agent used in the present invention. Especially when used for color proofing, pigments and dyes of the same color as the ordinary colors required therefor, i.e., yellow, magenta, cyan, and black, are required, but other metal powders, white pigments, fluorescent pigments, etc. used. The following examples are just a few of the many pigments and dyes known in the art. (CI means color index) Victoria Pure Blue (CI 42595) Auramine 0 (CI 41000) Katilon Priliant Flavin (CI Basic 13) Rhodamine GGCP (CI 45160) Rhodamine B (CI 45170) Safranin OK70: 100 (CI 50240) Erioglaucine X (CI 42080) First Black HB (CI 26150) No.1201 Lionol Yellow (CI 21090) Lionol Yellow GRO (CI 21090) Shimla First Yellow 8GF (CI 21105) Benzidine Yellow 4T-564D (CI 21095) Shimla Fast Red 4015 (CI 12355) Lionol Red 7B4401 (CI 15830) Fast Gen Blue TGR-L (CI 74160) Lionol Blue SM (CI 26150) Mitsubishi Carbon Black MA-100 Mitsubishi Carbon Black # 30, # 40 , # 50 Consideration of target content of optical density and removability of developer It can be determined by methods known to those skilled in the art Te. For example, the content of a dye is suitably 5% to 75% by weight, and the content of a pigment is suitably 5% to 90% by weight.

Since the photosensitive composition and the colorant have poor or poor film-forming properties, it is preferable to form a film using a binder.

As the binder, a polymer compound which is film-forming and solvent-soluble and can be dissolved or swelled in a developer is used.

Specific examples of the polymer compound for a binder suitably used for the coloring record include acrylic acid and methacrylic acid and their alkyl esters or sulfoalkyl esters, phenolic resin, polyvinyl butyral, polyacrylamide, ethyl cellulose and acetic acid / butyric acid cellulose, Cellulose derivatives such as cellulose acetate propionate, cellulose acetate, benzyl cellulose, cellulose propionate, other polystyrene, polyvinyl chloride,
Examples include chlorinated rubber, polyisobutylene, polybutadiene, polyvinyl acetate, and copolymers thereof, cellulose propionate, cellulose acetate phthalate, and the like.

In addition to the above materials, a plasticizer, a coating improver, and the like can be further added to the image forming layer, if necessary.

Examples of the plasticizer include various low molecular compounds such as phthalates, triphenyl phosphates and maleates, and examples of the coating improver include surfactants such as a fluorine-based surfactant and ethyl cellulose polyalkylene ether. Nonionic surfactants and the like can be mentioned.

On the other hand, as the above-mentioned intermediate heat-fusible layer, a layer which is transparent and non-adhesive at room temperature, but which can be heat-fused in a temperature range of 80 ° C to 160 ° C is preferable.

For this, a film-forming thermoplastic resin having a softening point of 70 ° C to 140 ° C as described below is used. For example, olefin (co) polymer, vinyl chloride (co) polymer, vinylidene chloride (co) polymer, vinyl acetate (co) polymer, (meth) acrylate (co) polymer, styrene / (meth) Acrylate copolymers, polyesters, vinyl butyral resins, chlorinated rubbers, cellulose derivatives, preferably styrene / (meth) acrylate copolymers, polyesters, etc., which are used alone or in combination, May be used by mixing other resins or plasticizers.

The thickness of the heat-fusing property is suitably in the range of 1 to 20 μm,
Particularly preferably, it is in the range of 2 to 8 μm. When the thickness of the heat-fusible layer is equal to or greater than the thickness of the colored image-forming layer, the colored image formed on the heat-fusible layer is heated, pressed, and transferred to the image receiving material surface. In this case, even the fine non-image area, that is, even the heat-fusible layer in the narrow area surrounded by the large image area can be effectively fused to the surface of the image receiving material to obtain a uniform and good transfer image. it can.

In order to produce the colored image forming material according to the present invention, the above-mentioned layer constituting material may be dissolved in an appropriate solvent and then applied to the above-mentioned release treatment or a support having an undercoat layer sequentially or simultaneously.

Examples of the solvent include water, methanol, ethanol, acetone, ethyl acetate, methyl cellosolve, ethyl cellosolve, dioxane, methyl ethyl ketone, cyclohexanone, diethylene glycol monomethyl ether, γ-butyrolactone, tetrahydrofuran, methylene chloride, ethylene chloride, dimethyl sulfoxide, and dimethylformamide. These can be used alone or in combination of two or more.

Various light sources such as an ultra-high pressure mercury lamp, a tungsten lamp, a mercury lamp, a xenon lamp, a fluorescent lamp, a CRT light source, and a laser light source are used for imagewise exposure for forming a colored image.

In the development, the developer and the like shown in the above-mentioned conventional example can be used.

As the image receiving sheet, white paper, for example, art paper, coated paper, high quality paper, synthetic paper, or the like can be used. In the above-described indirect transfer method, the obtained colored image is temporarily transferred and laminated on a temporary image receiving sheet, and then transferred again onto a transfer surface such as art paper, coated paper, or synthetic paper. As the image receiving sheet used in the indirect transfer system, a sheet provided with an image receiving layer containing a thermoplastic organic polymer on a support or a sheet provided with an image receiving layer having photosensitivity can be used.

As the support used when forming the material to be transferred, various materials can be used. For example, a polyester film, particularly a biaxially stretched polyethylene terephthalate film is preferable in view of dimensional stability against water and heat. Also, an acetate film, a polyvinyl chloride film, a polystyrene film, a polypropylene film may be used.

Example Next, an example will be described.

(Example 1) "Evaluation of photosensitive transfer material" described in Japanese Patent Application Laid-Open No. 63-2040, using substantially the same material as Example 1 described in Japanese Patent Application Laid-Open No. 63-2040.
A multicolor image was formed on art paper in the same manner as described in the column.

In this case, in this embodiment, when transferring the image of the image sheet to the image receiving sheet and when transferring the multicolor image transferred to the image receiving sheet to art paper, the surface of the aluminum plate having a thickness of 0.5 mm is coated with silicone. Rubber (manufactured by Toshiba Silicone, "TS
A guide plate coated and dried with a toluene solution of E-399 ”) to a dry film thickness of 50 μm was used.

(Comparative Example 1) As a guide plate, 100
Example 1 was repeated except that a polyethylene terephthalate film having a thickness of μm was laminated and the peripheral edge was fixed with an adhesive tape, and a supplementary test of the technique of JP-A-60-255497 was conducted.

(Example 2) A colored photosensitive layer dispersion having the following composition was coated on a biaxially stretched polyethylene terephthalate film (Tough Top COTO, manufactured by Toray Industries Co., Ltd.) with a release treatment on the surface, using a wire bar to obtain a dry film thickness. Apply to 1 μm, dry, 4
A colored image forming material was prepared.

2,3,4-Trihydroxybenzophenone-naphthoquinone-1,2-diazidesulfonic acid ester 0.616 g Phenol formaldehyde novolak resin 4.384 g (Mw: 960, Mn: 496) Atyl cellosolve 39.6 g Fluorine-based interface Activator 0.25 g (3M FC-430) <Pigment> Black: carbon black 0.99 g MA-100 (manufactured by Mitsubishi Chemical) Cyan: cyanine blue 4920 0.55 g (manufactured by Dainichi Seika) Magenta: Seika First Carmine 1483 0.68 g (manufactured by Dainichi Seika) Yellow: Seika First Yellow H-7055 0.68 g (manufactured by Dainichi Seika) The four-color image forming material obtained above is used for the color separation net positive film of each color on the polyethylene terephthalate film surface. Superimposed, 50c with 4kW metal halide lamp
Image exposure was performed for 20 seconds from a distance of m, and development was performed by immersion in the following phenomenon liquid for 30 seconds to form four colored images.

<Developer> Na ₂ CO ₃ 15 g Surfactant (Perox NBL manufactured by Kao Atlas) 50 g Distilled water 1000 g
After passing through a pair of nip rolls heated to 90 ° C. under a pressure of 5 kg / cm ² at a speed of 50 cm / min, the polyethylene terephthalate film was peeled off. Peeling was easy and a black image was transferred on the art paper.

Subsequently, the colored images were transferred in the order of cyan, magenta, and yellow, and a color proofing image composed of four colors was obtained on art paper. Only the colored image part is transferred to the art paper, that is, the non-image part is exposed,
The obtained color proofing image was very similar to the image quality of the printed matter created by the normal offset printing.

In the above, when transferring each color to art paper, 0.5mm
A guide plate in which a film of silicone rubber (ink repelling tape, “IRT-L” manufactured by Toray Industries, Inc.) was attached to the surface of a thick glass epoxy plastic plate with a laminator was used.

(Comparative example 2) Except that the guide plate in Comparative example 1 was used, it was the same as Example 2.

<Results> The registration marks of the image / image receiving sheet in each of the above examples are 4
Formed at the corner, 400mm in X direction, Y direction orthogonal to this
After the transfer, the positional deviation between the transferred images was evaluated by measuring the maximum deviation width of the register marks between the multicolor images, and the results shown in Table 1 were obtained.

In Comparative Examples 1 and 2, wrinkles were found on the image sheet after the transfer process, but in Examples 1 and 2, no wrinkles were generated.

〔The invention's effect〕

As described above, according to the present invention, the displacement of the transferred image can be sufficiently prevented.

[Brief description of the drawings]

 FIG. 1 is a schematic explanatory view of the present invention. DESCRIPTION OF SYMBOLS 1 ... Image sheet, 1a ... Image 2 ... Image receiving sheet, 3 slip prevention layers 4 ... Support, 5 ... Roller

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Manabu Watanabe 1 Sakura-cho, Hino-shi, Tokyo Inside Konica Corporation (72) Inventor Toyoyoshi Urano 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Within the research institute (72) Inventor Shinya Mayama 1000 Kamoshita-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsubishi Chemical Co., Ltd. (56) References JP-A-63-127243 (JP, A) JP-A-63-309946 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 7/00-7 / 42

Claims (1)

(57) [Claims] 1. An image sheet on which an image is formed and an image receiving sheet for receiving the image are superimposed, and a rigid support having a layer containing rubber and having rigidity is provided on the superimposed sheet. An image transfer method, wherein an image is transferred by applying pressure or applying pressure and heating between a pair of rolls in a state in which a layer containing rubber is on the image receiving sheet side and in a superposed state.