JP2874828B2 - Photosensitive transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor image forming material, and more particularly to a photosensitive transfer used for obtaining a prepress color proof which can be used mainly for a proofing work indispensable in a photomechanical process. It is about a sheet.

[0002]

2. Description of the Related Art In color printing, a prepress color proof for checking the color and tone of a finished print is mainly classified into an overlay method and a surprint method depending on its form.

In the overlay method, each color separation master is printed in accordance with each color on a transparent support coated with a color sensitizer, and each color is superimposed on a white sheet for calibration (USP3136637, USP3221553, USP332668
2). This method can quickly produce a proof and can be used as a color proof by appropriately combining two or three colors. However,
Since this type also overlaps the respective transparent supports, turbidity is produced, and there is a noticeable difference in comparison to printed matter printed on a printing press or a proofing machine.

Various methods for forming a multicolor image by a surprint method have been proposed. That is, in the method using a pressure-sensitive adhesive, a colored photosensitive layer and a pressure-sensitive adhesive layer are mainly laminated on a support in this order. By peeling off, the colored photosensitive layer is transferred onto the backing paper together with the adhesive layer. Thereafter, a color separation document corresponding to the color tone of the colored photosensitive layer is exposed in close contact, developed with a dedicated developer, and dried to form a separation image. Further, the same operation is repeated for colors different from the above to form a multicolor image. (Japanese Patent Publication No. 47-27441)

[0005] Further, there have been proposed various devices which use transfer by heat without using a pressure-sensitive adhesive. For example, if a document is overlaid on a support provided with a colored photopolymer layer exhibiting adhesiveness at a certain temperature or higher and exposed in close contact, only the unexposed portions are transferred to the paper base because the exposed portions no longer exhibit adhesiveness. Things (USP3203805). Alternatively, after exposing and developing a colored polymer layer on a support, a colored image is thermally transferred to a base having a heat-sensitive adhesive (USP4304836). Alternatively, there is a method of exposing and developing a support / release layer / colored photosensitive layer to obtain a colored image, applying a heat-sensitive adhesive to the bonding surface or the image receiving surface, and performing thermal transfer (USP3721557, Tokiko 46
-15326, JP-B-49-441).

The method for forming a multicolor image using the photosensitive transfer sheet of the present invention comprises a transparent release layer strongly adhered to a transparent support, and a heat-fusible transparent layer peelable from the release layer. An intermediate layer, a photosensitive transfer sheet having a colored photosensitive layer laminated thereon, (1) after closely exposing the photosensitive material with actinic light through a negative document, developing a non-exposed portion to form an image, 2) The formed image surface is further brought into close contact with the heat-fused surface of the material to be transferred having a heat-fused layer, and after heating and pressing, the transparent support is peeled off from the intermediate layer, and the colored image is coated together with the intermediate layer. In the step (1), different color tone of the colored photosensitive layer is prepared, a negative document is selected according to each color tone, and contact exposure and development processing are performed. And forming an image, and coloring certain tones of them in step (2) After transferring the image to the material to be transferred, (3) the image surface of the photosensitive material on which the colored image having a different color tone is formed is brought into close contact with the transferred surface of the material to be transferred obtained in step (2). After heating and pressurizing, the transparent support is peeled off from the intermediate layer, and the colored image is transferred together with the intermediate layer onto the already-transferred surface of the material to be transferred. This is a method for forming a multicolor image, characterized by repeating (3).

According to this method, since the formed image is sequentially transferred one by one onto the material to be transferred, the exposure operation for four colors can be performed simultaneously, and thus the method has an advantage that the operation time can be reduced.

[0008] However, the disadvantage of this method is that the colored photosensitive layer of the photosensitive transfer sheet has a different color tone and contains a colorant having a different absorption characteristic of active light, resulting in a difference in sensitivity and a different optimum exposure amount. was there. For example, a black photosensitive transfer sheet is significantly inferior in sensitivity to photosensitive transfer sheets of other colors due to absorption characteristics of actinic rays by a black pigment, and in order to obtain an image intensity equivalent to other colors, More exposure was needed. Therefore, the advantage that the simultaneous exposure processing of four colors is possible cannot be fully utilized.

[0009]

SUMMARY OF THE INVENTION According to the present invention, in the above-mentioned multicolor image forming method, the sensitivities of the respective color photosensitive layers having different color tones and containing a colorant having a different active light absorption characteristic are made the same to improve workability. It is another object of the present invention to provide a multicolor image forming material for obtaining a more accurate prepress color proof.

[0010]

Means for Solving the Problems The present inventors have discovered that the actinic light-reflecting substance is added to the release layer to increase the reflectance, thereby increasing the photosensitive speed of the colored photosensitive layer. That is, it has been found that the sensitivity of the photosensitive layer can be controlled by reflecting the actinic rays transmitted through the colored photosensitive layer (actinic rays not used in the reaction) by the release layer and changing the reflection characteristics.

That is, a transparent active light-absorbing layer comprising an active light-absorbing agent, an antistatic agent and a film-forming polymer resin is adhered to one surface of the transparent support, and the transparent support is strongly adhered to a different surface. The photosensitive transfer sheet of the present invention, on which a transparent release layer, a heat-fusible transparent intermediate layer releasable from the release layer, and a colored photosensitive layer are laminated, (1) the photosensitive material is passed through a negative document Is exposed to actinic light, and then the unexposed area is developed to form an image. (2) The formed image surface is further brought into close contact with the heat-sealed surface of the transfer-receiving material having a heat-sealed layer. After the heating and pressurizing, the transparent support is peeled off from the intermediate layer, and the color image is transferred to the material to be transferred together with the intermediate layer. In the step (1), the color tone of the colored photosensitive layer is adjusted. Prepare different ones, according to each color tone, shade Select the document, contact exposure,
After developing, forming an image and transferring the colored image of a specific tone among them to the material to be transferred in step (2), (3) further forming a photosensitive image having a colored image of a different color from the above. After bringing both image surfaces of the material into close contact with the already-transferred surface of the material to be transferred obtained in step (2), applying heat and pressure, the transparent support is peeled off from the intermediate layer, and the colored image is transferred with the intermediate layer. In the step of transferring the material onto the already-transferred surface, the step (3) is repeated for the third and subsequent colors. In forming a multicolor image, the release layer of the photosensitive transfer sheet is It contains an actinic ray reflective substance. The gist of the present invention is as follows: (1) On one surface of a transparent support, there is provided a transparent active light-absorbing layer comprising an active light-absorbing agent, an antistatic agent and a film-forming polymer resin; A release layer is formed on a photosensitive transfer sheet in which a transparent release layer strongly adhered to a transparent support, a heat-fusible transparent intermediate layer that can be released from the release layer, and a colored photosensitive layer are laminated. A photosensitive transfer sheet characterized in that an actinic ray-reflective substance is contained in the film-forming polymer resin; A photosensitive transfer sheet characterized by being any one of a pigment, powdered aluminum, titanium oxide, zinc oxide, and barium sulfate, or a mixture thereof; (3) the active layer (360 nm) total reflectance of the release layer is 1
A photosensitive transfer sheet characterized by being at least 5%; (5) a photosensitive transfer sheet, wherein the intermediate layer is any one of polyester, ethylene-vinyl acetate copolymer, and an acrylic compound, or a mixture thereof; (6) The colored photosensitive layer has the following general formula (I) or (II) (Wherein R ₁ and R ₂ are each independently of the other
Represents a hydrogen atom or an alkyl group, Y ⁻ represents a conjugate basic ion of an acid, specifically a halogen ion such as Cl ⁻ or Br ⁻ , m represents an integer of 1 to 6, and n represents 0 or 1. Represented by a photosensitive resin and a colorant.

Hereinafter, the present invention will be described in more detail. As the transparent support used in the photosensitive transfer sheet of the present invention,
Plastic films such as polyethylene terephthalate, polypropylene, polyethylene, polyvinyl chloride, polystyrene, polycarbonate, and triacetate are suitable, and among them, a biaxially stretched polyethylene terephthalate film is preferable because of its excellent strength, heat resistance, dimensional stability, and the like. . The thickness of the support is not particularly limited, but is suitably about 50 to 150 μm.

The actinic ray-absorbing layer used in the photosensitive transfer sheet of the present invention comprises a film-forming polymer, and further contains a salicylate-based, benzophenone-based, benzotriazole-based ultraviolet absorber to prevent halation. Has been added. And from the point of handling, conductive resin,
An antistatic agent such as a conductive powder is also added. In order to prevent blocking, a pigment may be added to make the surface matte. This prevents the light passing through the peeling layer from causing halation, affecting the colored photosensitive layer and increasing the dot gain.

The release layer used in the photosensitive transfer sheet of the present invention is made of any one of urethane resin, melamine resin, fluororesin, silicone resin, polyester, polyolefin or a mixture thereof, and has a coating thickness of 1 to 10 μm.
m, more preferably 1 to 5 μm. Further, by adding a pigment to the release layer to form a mat, the peel strength between the release layer and the intermediate layer provided thereon can be stabilized. Further, a matted pattern is also formed on the intermediate layer and on the colored photosensitive layer further coated thereon, so that air can be smoothly evacuated between the original and the colored photosensitive layer when the exposure is decompressed, thereby improving the adhesion between the two. It is also possible.

Further, the anti-blocking performance and the slipperiness on the intermediate image-receiving sheet are improved, and the air between the image-receiving sheet and the intermediate layer is easily released when the image is transferred to the intermediate image-receiving sheet by heating and pressing. Adhesion can be improved. By selecting the type, the particle size, and the amount of the added pigment, it is possible to adjust the reflection characteristic of the actinic ray and control the sensitivity of the colored photosensitive layer.

Examples of the pigment used for this purpose include surface-treated mica pigments, powdered aluminum, inorganic fine particles such as titanium oxide, zinc oxide, barium sulfate, silicon dioxide, calcium carbonate, and alumina. Plastic powders such as polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polycarbonate, acrylate resin, methacrylic acid resin, polyacrylonitrile and copolymers of acrylonitrile, and fine powders such as starch and cellulose. In particular, surface-treated mica-based pigments, powdered aluminum, titanium oxide, zinc oxide, and barium sulfate are suitable for increasing the sensitivity of the colored photosensitive layer, and the active layer (360 nm) total reflectance of the release layer is suitable. 15% or more, more preferably 20% or more is desirable. The size of the pigment is 0.01 to 20 μm, more preferably 1 to 20 μm.
10 μm is suitable, and the sensitivity of the photosensitive transfer sheet of each color can be equalized by preparing a release layer corresponding to the colored photosensitive layer of each color.

The intermediate layer used in the photosensitive transfer sheet of the present invention is non-adhesive at room temperature and becomes tacky and fusible by heat without being insoluble in water and hindering hue and transparency. And the colored photosensitive layer, which can be easily peeled off from the release layer and is insolubilized by light applied thereon, has sufficient adhesiveness especially after photoinsolubilization, and also has sufficient adhesiveness with the sheet to be transferred. Is selected from substances having

For example, the following film-forming polymer substances can be mentioned. Polyacrylate and acrylate copolymer, polymethacrylate and methacrylate copolymer, polyacrylamide and acrylamide copolymer, polyvinyl acetate and vinyl acetate copolymer, polyvinyl chloride and Ethylene copolymers such as vinyl chloride copolymer, polyvinylidene chloride and vinylidene chloride copolymer, polystyrene and styrene copolymer, ethylene and vinyl acetate, ethylene and acrylate, ethylene and vinyl chloride ethylene and acrylic acid, Polyvinyl acetal resin such as polyvinyl butyral and polyvinyl formal, polyamide resin such as polyester resin, nylon and copolymerized nylon, various rubbers such as synthetic rubber and chlorinated rubber, and polyethylene such as polyethylene and polypropylene Olefins, cellulose derivatives, shellac, various waxes.

In addition, a mixture of these high-molecular substances or a mixed system with another substance such as another high-molecular substance or a plasticizer can also be used. For example, a combination with another substance that can prevent the tackiness even if it shows tackiness at room temperature, or even a substance that does not show tackiness even when heated, a tackifier, a plasticizer and the like Combinations are also conceivable, and not only a single substance, but also various combinations depending on the type of the support, etc., as necessary, and therefore, are not necessarily limited to the above substances.

For laminating the intermediate layer on the release layer provided on the support, a solution of the above-mentioned polymer substance is applied on the release layer by a usual method and dried, or the solid polymer is used as the above-mentioned polymer. The material may be melted and applied (hot melt coating), or a film made of the above polymer material may be laminated. The thickness of the intermediate layer is preferably 0.5 to 10 μm, more preferably 0.5 to 3 μm.

Used in the photosensitive transfer sheet of the present invention,
As the colored photosensitive layer which is soluble in water and insolubilized by light, a conventionally known photosensitive resin can be used, and examples of the negative type are as follows. (1) A composition comprising a photosensitive ferric salt that gives ferrous ions by light such as ferric citrate ammonium and ferric oxalate, and a hydrophilic resin such as gelatin and polyvinyl alcohol. (2) Gelatin, fish glue, gum arabic, polyvinyl alcohol, polyacrylamide, carboxymethylcellulose, hydroxymethylcellulose, and other water-soluble resins, and p-aminodiphenylamine, benzidine, dianisidine, tetrazonium salts of diamino compounds such as tolisodin, or p- A composition comprising a diazo compound obtained by condensing diazophenylamine and paraformaldehyde and a diazo resin obtained by condensing paraformaldehyde. (3) A composition comprising a diazo compound such as p-diazodiphenylamine and a diazo resin obtained by condensing paraformaldehyde. (4) 4,4'-diazidostilbenzene, 2,2'-
A composition comprising an azide compound such as sodium disulfonate and a water-soluble resin such as polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, and gelatin. (5) 4,4'-diazidostilbenzene, 4,4'-
A composition comprising an azide compound such as diazide chalcone and a cyclized rubber. (6) A composition comprising a cinnamate ester of polyvinyl alcohol, an allyl acrylate and a sensitizer such as 5-nitroacenaphthene and 1,2-benzanthraquinone. (7) A composition comprising a vinyl monomer such as acrylamide and acrylic acid, a cellulose derivative and a polyvinyl alcohol derivative, and a photopolymerization initiator. (8) A composition comprising acrylamides such as methylenebisacrylamide and N, N'-hexamethylenebismethacrylamide, an alcohol-soluble nylon, and a photopolymerization initiator. (9) A composition comprising an ethylenically unsaturated monomer such as acrylamide and acrylic acid, a photosensitive ferric salt such as ferric citrate ammonium, and a hydrophilic resin. (10) A modified polyvinyl alcohol composition obtained by adding a photosensitive group such as a stilvinylilium group, a stilbazolium group, and a stilquinolium group to polyvinyl alcohol.

Examples of the positive type include naphthoquinone-
There is a composition of a quinonediazide compound such as (1.2) -diazidesulfonic acid ester and an alkali-soluble phenol formaldehyde resin. The above photosensitive resin is a typical example, and the present invention is not limited to these.

As the colorant, pigments dispersible in water,
It can be selected from a wide range such as water or alcohol-soluble dyes, but it must have good miscibility with the above water-soluble polymer substance, photoinsolubilizer, and modified polyvinyl alcohol, and do not adversely affect photosensitivity and developability. The color tone is basically four colors of cyan, magenta, yellow, and black in the case of color proofing in photoengraving, and it is naturally desired that each color is close to that of the printing ink. The amount of the colorant to be added depends on the type and the amount of the colored photosensitive layer to be applied, but should be determined by the desired optical reflection density of the colored image after the formed image is transferred to the material to be transferred.

In the colored photosensitive layer which is insolubilized by light, in addition to the above, a stabilizer for preventing a dark reaction and a leveling agent for improving the coating property when the colored photosensitive layer is provided on the surface of the release layer. An antifoaming agent, a surfactant and the like can be added as needed. In providing the colored photosensitive layer, the above components are mainly dissolved or decomposed in water and mixed, but for the purpose of defoaming and improving coatability, a water-soluble organic solvent such as an alcohol is used as necessary. It can also be used partially as a diluent.

The thickness of the colored photosensitive layer is preferably as thin as possible from the viewpoint of resolution such as halftone reproducibility, but is preferably 0.5 to 5 μm, more preferably 1 to 3 μm in consideration of the image density by the colorant. I have. In applying the colored photosensitive layer on the release surface, there is no particular limitation as long as there is no pinhole or the like and a uniform coating film can be obtained by any conventionally known method.

Next, the transfer material used in the present invention will be described. Examples of the support include paper, plastic films, paper / plastic composite materials, glass plates, metal plates, and the like. As the substance used for the heat-sealing layer that is closely adhered and laminated on the support, a substance which is tacky at room temperature and exhibits tackiness and fusing property by heat, more specifically, an intermediate layer of a photosensitive transfer sheet And a material which can mutually fuse with the colored photosensitive layer after exposure and development when heated. Examples of those substances are selected from the same substances as those used for the intermediate layer of the photosensitive transfer sheet. In this case, the mutual adhesion between the intermediate layer and the colored photosensitive layer is mainly considered. In addition, not only a single substance but also a wide selection from a mixed system or the like is available. In applying the heat-sealing layer to the support of the image receiving sheet, a solution of the above-described polymer substance is applied to the support by a usual method and dried, or the solid polymer substance is coated. Hot melt coating (hot melt coating)
Further, a film made of the above-mentioned polymer substance may be laminated. The thickness of the heat sealing layer depends on the resin used, but is preferably 3 to 15 μm.

The transfer sheet of the present invention is first subjected to contact exposure with actinic rays through a net-decomposed film for each color obtained in the photomechanical process, as shown in FIG.
An image is formed by a development process (Step 1). By selecting the photosensitive transfer sheet of the present invention corresponding to each separation color (the film corresponding to the cyan printing plate was inverted to the photosensitive transfer sheet of the present invention colored in cyan) to have each colored image. A photosensitive transfer sheet is obtained. Here, the non-image portion of the photosensitive transfer sheet exposes the intermediate layer B-2. (The heat-fused layer E of the transfer material of the image-receiving sheet is also heat-sealed with the colored photosensitive layer (image portion) C-1 after image formation, but is not complete by itself, and the heat exposed to the non-image portion is not sufficient. Due to the mutual fusion with the fusible intermediate layer B-2, thermal transfer is more complete.)

Next, the image surface of the photosensitive transfer sheet is brought into close contact with the transfer surface (the surface having a heat-sealing layer) of the material to be transferred, and heated and pressed to form an intermediate layer (unexposed portion) of the photosensitive transfer sheet. , Non-image portion) B-2 and the heat-fused layer E of the material to be transferred mutually fuse (the photo-insolubilized portion of the colored layer, ie, the image portion also fuses with the heat-fused layer of the material to be transferred). Cannot adhere as strongly as the non-image area because one of them is not heat-fusible). Thereafter, when the support A of the photosensitive transfer sheet is peeled off together with the release layer B-1, the color separation image becomes the intermediate layer B -2 is easily and firmly transferred onto the material to be transferred (Step 2).

Further, the colored image of the second color is thermally transferred on the above-mentioned transferred image. In this case, the surface after the transfer of the first color is provided on the heat-fusible intermediate layer (the first color). Middle layer B
-2), the image can be easily and firmly transferred as in the case of the first color (step 3). From the third color onward, sequentially different colored images can be easily transferred together with the intermediate layer B-2 with the same result as the second color, and finally a multicolor image can be formed on the material to be transferred (step 4). . Here, a multicolor image very similar to the final printed matter can be obtained by selecting a color tone (basically cyan, magenta, yellow, and black) and a density close to those of the printing ink of the colored image obtained by the present invention. Can be used for color proofing similar to proofing.

As is apparent from the above description, in this method, the formed images are sequentially transferred one by one onto the material to be transferred, so that the photosensitive transfer sheet of each color such as cyan, magenta, yellow, and black is transferred. Excellent workability because exposure work can be performed at the same time. However, if the optimum exposure amount differs depending on the sensitivity difference of each color, this advantage cannot be fully utilized. The present invention makes it possible to control the sensitivity of the colored photosensitive layer by the reflection characteristics of the release layer, and the exposure work of each color can be performed simultaneously with the optimum exposure amount of each color, which contributes to the improvement in workability of the printing plate making process. There is something very big to do.

[0031]

The following examples are provided to further clarify the present invention, but the present invention is not limited thereto. Note that all “parts” in Examples are parts by weight.

(Example 1) <Active ray absorption amount forming liquid> 65 parts of Saftomer STH-87 (acrylic conductive polymer: Mitsubishi Yuka Co., Ltd.) 31 parts of tesfan 322 (acrylamide copolymer: Hitachi Chemical Polymer ( Co., Ltd.) Thermolac F1 19 parts (Polyester: Soken Chemical Co., Ltd.) Dryer 900 1.9 parts (Paratoluenesulfonic acid: Hitachi Chemical Co., Ltd.) Tinuvin-109 3 parts (Benzotriazole-based UV absorber: Ciba-Geigy Co., Ltd.) SILOID 308 1.9 parts (Silica: Mizusawa Chemical Co., Ltd.) Toluene 100 parts Methyl ethyl ketone 100 parts Ethyl cellolob 48 parts

<Release Layer Forming Solution-1> 5 parts of Tesfine 322 (acrylamide copolymer: Hitachi Chemical Co., Ltd.) Dryer 900 0.6 parts (p-toluenesulfonic acid: Hitachi Chemical Co., Ltd.) Ryuron Qu-628 100 parts (vinyl chloride-vinyl propionate copolymer: Tosoh Corporation) Mizuka Seal SK-7 0.8 parts (silica: Mizusawa Chemical Co., Ltd.) Toluene 67 parts Methyl ethyl ketone 67 parts Cyclohexanone 33 parts

<Release Layer Forming Solution-2> 5 parts of Tesfine 322 (acrylamide copolymer: Hitachi Chemical Co., Ltd.) Dryer 900 0.6 parts (paratoluenesulfonic acid: Hitachi Chemical Co., Ltd.) Ryuron Qu-628 100 parts (vinyl chloride-vinyl propionate copolymer: Tosoh Corporation) IRIODIN-111 17 parts (Mica pigment: Merck Japan KK) Toluene 36 parts Methyl ethyl ketone 36 parts Cyclohexanone 18 parts

<Intermediate layer forming liquid> 91 parts of Vironal MD-1100 (polyester: Toyobo Co., Ltd.) 78 parts of Vironal MD-1400 (polyester: Toyobo Co., Ltd.) water 100 parts isopropyl alcohol 67 parts butyl cellosolve 33 parts dimethylformamide 22 parts

<Coloring photosensitive layer forming solution> Black solution SBQ-modified PVA 10% aqueous solution 100 parts (N-methylstilbazolium group 1.25 mol% introduced, average polymerization degree 1700, saponification degree 88%) Pigment dispersion liquid 4 parts ( Carbon black 20% water dispersion) Water 100 parts Isopropyl alcohol 10 parts

Using phthalocyanine blue, permanent carmine FB and permanent yellow HR instead of the above carbon black, a colored photosensitive layer solution for cyan, magenta and yellow was similarly prepared. However, pigment dispersions of yellow, cyan, magenta, and black were obtained by dispersing with the following composition using an ink mill for 3 hours. Coatings 20 parts Nonionic surfactant 1 part (mainly polyethylene glycol alkyl phenyl ether) Water 80 parts

Thickness of biaxially stretched liquid for forming active light absorbing layer
One side of a 100 μm polyethylene terephthalate film was coated with a roll coater and dried at 140 ° C. for 1 minute to form an active light absorbing layer of about 3 μm.

Next, a release layer forming solution-1 was applied on a surface different from the active light absorbing layer by a roll coater and dried at 140 ° C. for 1 minute to form a release layer of about 3 μm. The reflectance of the obtained release layer was measured (Hitachi 320 Spectrophotometer, 150
(using a device attached to a φ-integrating sphere), and showed a total reflectance of 8% (360 nm). An intermediate layer forming liquid is applied on the release layer by a roll coater, dried at 110 ° C. for 1 minute, and applied in an amount of about 1
A μm intermediate layer was formed. Further, a yellow liquid of a colored photosensitive layer forming liquid was applied thereon by a roll coater and dried to form a colored photosensitive layer having a coating amount of about 2 μm, thereby obtaining a yellow photosensitive transfer sheet. A colored photosensitive layer (coating amount: about 2 μm) was similarly formed for magenta and cyan to obtain a photosensitive transfer sheet.

Separately, a release layer forming solution-2 was applied to the opposite surface of the active light absorbing layer using a roll coater and dried at 140 ° C. for 1 minute to form a release layer of about 3 μm. When the reflectance was measured in the same manner, a total reflectance of 35% (360 nm) was obtained. An intermediate layer forming liquid was applied on the release layer by a roll coater and dried at 110 ° C. for 1 minute to form an intermediate layer having a coating amount of about 1 μm. Further, a black liquid of the colored photosensitive layer forming liquid was applied thereon by a roll coater and dried to obtain a coating amount of about 2 μm.
Was formed to obtain a black photosensitive transfer sheet.

A color separation net negative film for a black (sumi) plate is brought into close contact with the colored photosensitive surface of the thus-prepared black photosensitive transfer sheet, and a 1 Km high-pressure mercury lamp of 2 KW is applied.
Exposure for 15 seconds from the distance of
Water was removed by washing with normal temperature water jetted from a nozzle pressurized to cm ² , water was removed, and after drying with hot air at about 50 ° C., a black-colored negative-positive image was obtained. Similarly, cyan, magenta,
With respect to yellow, a negative-positive image colored cyan, magenta, and yellow was obtained by performing the same operation as above using the corresponding color separation net negative films. In each case, excellent halftone dot reproducibility equivalent to each color tone was obtained with the same exposure amount of 15 seconds.

Further, using a coated paper having a basis weight of 129.7 g / m ² as a support, a toluene / ethyl acetate solution of a copolymer of vinyl chloride and vinylidene chloride was applied to one side of the coated paper, dried and dried to a thickness of 6 μm. A transfer material was obtained by forming a fusion layer.
The image surface of the photosensitive transfer sheet for black having the positive image is superimposed on the surface of the heat-sealing layer of the material to be transferred, pressed with a roller heated to 100 ° C., and then the support of the photosensitive transfer sheet is peeled off. When peeled from between the and the intermediate layer, the colored image was easily transferred onto the transfer surface of the transfer material together with the intermediate layer. Adhesion during transfer was good. Next, the cyan, magenta, and yellow images were successively thermally transferred onto the black image transferred onto the transfer material by the same operation, thereby obtaining a multicolor image of four colors on coated paper.
This was a high precision prepress color proof very similar to the final print.

Example 2 Release Layer Forming Solution-2 of Example 1
All were performed in the same manner as in Example 1 except that the amount of the pearl pigment was changed as follows.

<Release Layer Forming Solution-2> 5 parts of Tesfine 322 (acrylamide copolymer: Hitachi Chemical Co., Ltd.) Dryer 900 0.6 parts (paratoluenesulfonic acid: Hitachi Chemical Co., Ltd.) Ryuron Qu-628 100 parts (vinyl chloride-vinyl propionate copolymer: Tosoh Corporation) IRIODIN-111 10 parts (Pearl pigment: Merck Japan K.K.) Toluene 36 parts Methyl ethyl ketone 36 parts Cyclohexanone 18 parts

When the above release layer forming liquid-2 was used for a photosensitive transfer sheet for black in the same manner as in Example 1, the total reflectance of the obtained release layer was 22% (360 nm), and the same exposure amount for 20 seconds was used. As a result, halftone dot reproducibility equivalent to each color tone was obtained. The multicolor image formed on the transfer material was a high-precision prepress color proof that closely resembled the final print.

When the above release layer forming liquid-2 was used for a photosensitive transfer sheet for black in the same manner as in Example 1, the total reflectance of the obtained release layer was 22% (360 nm), and the same exposure amount for 20 seconds was obtained. As a result, halftone dot reproducibility equivalent to each color tone was obtained. The multicolor image formed on the transfer material was a high-precision prepress color proof that closely resembled the final print.

Example 3 Release Layer Forming Solution-2 of Example 1
All were carried out in the same manner as in Example 1, except that the following pigment was changed.

<Release Layer Forming Solution-2> 5 parts of Tesfine 322 (acrylamide copolymer: Hitachi Chemical Co., Ltd.) Dryer 900 0.6 parts (paratoluenesulfonic acid: Hitachi Chemical Co., Ltd.) Ryuron Qu-628 100 parts (vinyl chloride-vinyl propionate copolymer: Tosoh Corporation) FA-55W 30 parts (titanium oxide: Furukawa Kikai Metals Co., Ltd.) Toluene 36 parts Methyl ethyl ketone 36 parts Cyclohexanone 18 parts

When the above-mentioned release layer forming liquid-2 was used for a photosensitive transfer sheet for black in the same manner as in Example 1, the total reflectance of the obtained release layer was 20% (360 nm), and the same exposure amount for 20 seconds was obtained. As a result, halftone dot reproducibility equivalent to each color tone was obtained. The multicolor image formed on the transfer material was a high-precision prepress color proof that closely resembled the final print.

Comparative Example 1 Release Layer Forming Solution-1 of Example 1
Was performed in the same manner as in Example 1 except that the photosensitive transfer sheet of all colors of black, cyan, magenta, and yellow was used. The same halftone dot reproducibility was obtained with the same exposure amount of 15 seconds. Could not.

The above results are summarized in Tables 1 and 2.
By using a photosensitive transfer sheet having the total reflectance (%) of the release layer shown in Table 2, an exposure amount (second) capable of reproducing halftone dots having the characteristics shown in Table 1 was obtained. As can be seen from Table 1, Examples 1 to 3 have an exposure amount common to black, cyan, magenta and yellow, and each color, whereas Comparative Example 1 has no exposure amount common to each color.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

According to the photosensitive transfer sheet of the present invention, the sensitivity of the colored photosensitive layer can be controlled by adding an actinic light reflective substance to the release layer and adjusting the reflection characteristics. As a result, the sensitivity of the photosensitive transfer sheet of each color can be made the same, the workability is improved, and a more stable and accurate prepress color proof can be obtained.

[Brief description of the drawings]

FIG. 1 schematically shows the method of the present invention step by step.

[Explanation of symbols]

A-1 Transparent support of photosensitive transfer sheet A-2 Active light absorbing layer of photosensitive transfer sheet B-1 Release layer of photosensitive transfer sheet B-2 Intermediate layer of photosensitive transfer sheet C-1 to C-4 Each colored image of the photosensitive transfer sheet after exposure and development D Support of transfer material E Thermally fused layer of transfer material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-144647 (JP, A) JP-A-2-308253 (JP, A) JP-A-4-358151 (JP, A) JP-A-5-358 273759 (JP, A) JP-A-61-286858 (JP, A) JP-A-4-199056 (JP, A) JP-A-61-213843 (JP, A) JP-A-63-253941 (JP, A) JP-A-1-282542 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 7/004 G03F 7/105 G03F 7/11

Claims (5)

(57) [Claims] 1. A transparent active light-absorbing layer comprising an active light-absorbing agent, an antistatic agent, and a film-forming polymer resin is laminated on one surface of a transparent support, and the other surface of the transparent support is provided. In a photosensitive transfer sheet in which a transparent release layer strongly adhered to a transparent support, a heat-fusible transparent intermediate layer releasable from the release layer and a colored photosensitive layer are sequentially laminated, A photosensitive transfer sheet comprising an actinic light-reflective substance contained in a film-forming polymer resin for forming a layer. 2. The actinic ray-reflecting substance in the release layer is selected from the group consisting of mica pigments, powdered aluminum, titanium oxide, zinc oxide and barium sulfate, each of which has been subjected to various surface treatments.
2. The photosensitive transfer sheet according to claim 1, wherein the photosensitive transfer sheet is a mixture thereof. 3. The photosensitive transfer sheet according to claim 1, wherein the release layer has a total reflectance of actinic rays (360 nm) of 15% or more. 4. The film-forming polymer resin of the release layer is any one of a urethane resin, a melamine resin, a fluororesin, a silicone resin, a polyester and a polyolefin or a mixture thereof. The photosensitive transfer sheet according to any one of the above items. 5. The photosensitive transfer sheet according to claim 1, wherein the intermediate layer is any one of polyester, ethylene-vinyl acetate copolymer, and acrylic compound, or a mixture thereof. .