JPH01159648A - Transfer image forming method - Google Patents

Abstract

PURPOSE:To obtain a good transfer image without generating a color slurring by obtaining a colored image, and then, laminating the colored image with a material to be transferred, followed by subjecting the colored image part of the obtd. laminate to a high frequency induction heating to transfer the colored image to the material. CONSTITUTION:The image forming material mounted a color recording layer 2 comprising a coloring agent and a photosensitive composition on a supporting body 1 is image-wisely exposed and then developed, thereby forming the colored image 2', and the colored image and the material 3 to be transferred are laminated and then the colored image 2' is heated by giving a microwave to the obtd. laminate to transfer the colored image to the material 3 to be transferred. The multicolor proofing sheet is obtd. by repeating the operation as mentioned above with 4 times, thereby laminating 4 colors on the material. Thus, the good transfer image which does not generate the color slurring can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for forming a colored transfer image used for forming a color proof or the like.

[Conventional technology]

When producing color images, whether in lithography, letterpress or gravure, halftone methods are used and require color-separated halftone dots, positive or negative plates.

In order to save the trouble and time of proof printing performed before the actual printing, color sheets for color proofing, ie, color proofs, are known in the boat fishing industry.

Regarding the layer structure and image forming method of this color proof,
Various proposals have been made. As an example of this,
There is a method disclosed in Japanese Patent No. 41830, in which a photosensitive thermal transfer sheet having a heat-fusible and colored photosensitive layer provided on a support is imagewise exposed through a color separation mask, and then developed.
It is a method of thermally transferring onto a transfer surface such as paper or metal, and can be used for both the overlay method and transfer method of color proofing methods that use photopolymers.

[Problem that the invention seeks to solve]

However, in the conventional method described above, thermal transfer is usually carried out by passing it between heated rolls, but since the temperature required for thermal transfer is quite high, the support and transfer material stretch, causing the four colors (cyan and cyan) to stretch. , magenta, yellow, black), color shift (so-called registration mark shift) occurs in the image after lamination, making it impossible to obtain a good transferred image.

Therefore, the main object of the present invention is to provide a transfer image forming method capable of obtaining a good transfer image without color shift.

c. Means for Solving Problems] The above object is to provide an image forming material having a colored recording layer having a colorant and a photosensitive composition on a support, after imagewise exposure.
In a method of developing a colored image and transferring it to a material to be transferred to form a transferred image; After obtaining the colored image, the colored image area is heated by high frequency dielectric while the colored image is superimposed on the material to be transferred. This is achieved by performing the transfer.

[For production]

According to the present invention, when the colored image area is irradiated with microwaves, a high-frequency dielectric heating effect occurs, and the polar group components in the colored image generate heat, so that only the image area becomes heated, and the support and the transfer material are substantially heated. It does not get hot, so after transferring,
Even if four colors are stacked, a transferred image without color shift can be obtained.

[Specific structure of the invention]

The present invention will be explained in further detail below.

First, the present invention will be outlined with reference to FIGS. 1 to 4.
The image forming material shown in FIG. 1 in which a colored record N2 having a colorant and a photosensitive composition is formed on a support 1 is imagewise exposed and then developed to form a colored image 2 as shown in FIG. 2' is formed and superimposed on the transfer material 3 as shown in FIG. The image is transferred onto the transfer target material 3.

This process is repeated four times, and the four colors are laminated to form a multicolor proofing sheet.

Support for the photosensitive image-forming material used in the present invention Preferably, as a transparent support, a polyester film, especially a two-wheel stretched polyethylene terephthalate film is preferable in terms of dimensional stability against water and heat, but an acetate film, a polyvinyl chloride film, etc. film, polystyrene film,
Polypropylene films may also be used. Further, these supports may be used as they are, but in order to improve the transferability of the image after image formation, they may be subjected to a release treatment with a suitable oil-repellent substance, or may be provided with an undercoat layer.

18 Examples of oily substances include silicone resins, fluororesins, and fluorosurfactants, and examples of undercoat layers include alcohol-soluble polyamides, alcohol-soluble nylons, and partial esters of copolymers of styrene and maleic anhydride. polyvinyl acetate, polyacrylate, copolymer of polymethyl methacrylate and acrylate, polyvinyl chloride, copolymer of vinyl chloride and vinyl acetate,
Examples include those having weak adhesion to the transparent support, such as polyvinyl butylade, cellulose acetate phthalate, methylcellulose, ethylcellulose, cellulose diacetate, cellulose triacetate, and polyvinyl alcohol.

The colored recording layer of the present invention is removed imagewise by imagewise exposure and subsequent development to form a colored image.

This colored recording layer may be one layer or multiple layers. That is, it is sufficient that the colorant and the photosensitive composition are contained in any layer. For example, a laminated structure is formed by appropriately combining a colored photosensitive layer having a colorant and a photosensitive composition, a colored layer having a colorant and not having a photosensitive composition, and a photosensitive layer having a photosensitive composition and not having a colorant. It can be done. However, from the viewpoint of heating the colorant, it is desirable to contain the colorant in the layer furthest from the support.

Since the coloring agent and the photosensitive composition do not have film-forming properties, a binder is used.

As the binder constituting the colored recording layer, a polymer compound that is film-forming, solvent-soluble, and soluble or swellable in a developer is used.

Specific examples of this polymer compound include acrylic acid, methacrylic acid and their alkyl esters or sulfoalkyl esters, phenol resins, polyvinyl butyral,
Polyacrylamide, cellulose derivatives such as ethyl cellulose, cellulose acetate/acetate, cellulose acetate propionate, cellulose acetate, benzyl cellulose, cellulose propionate, other polystyrene, polyvinyl chloride, chlorinated rubber, polyisobutylene, polybutadiene, polyvinyl acetate, and copolymers thereof, cellulose acetate, cellulose propionate, cellulose acetate phthalate, and the like.

Dyes and pigments are added to the colored recording layer as colorants. In particular, when used for color proofing, pigments and dyes with a tone matching the usual colors required for that purpose, such as yellow, magenta, cyan, and black, are required, but in addition, metal powders, white pigments, fluorescent pigments, etc. used. The following are some of the many pigments and dyes known in the art.
, I means color index) Victoria Pure Blue (C, I 42595') Auramine O (C, I 41000) Cathylone Brilliant Flavin (C, I Basic 13) Rhodamine 6GCP (C, I 45160) Rhodamine B (C , I 45170) Safranin 0K70:
100 (C, I 50240) Erioglaucine X
(C, 142080) Fast Black HB (C
, I 26150) 11h1201 Lionor Yellow (C, I 21090) Lionor Yellow GRO (
C, I 21090) Simsy First Yellow 8G
F (C1I 21105) Benzidine Yellow 4T-
5640 (C, r 21095) Simsy First Red 4015 (C, I 12355) Lionor Red 7B4401 (C, I 15830) First Gen Blue TGR-L (C, I 74160) Lionor Blue-SM (C, I 26150) Mitsubishi Carbon Black MA-100 Mitsubishi Carbon Black M30. M2O, M50 The colorant/binder ratio of the colored recording layer used in the present invention can be determined by a method known to those skilled in the art, taking into account the target optical density and the removability of the colored recording layer to a developer. .

For example, in the case of dye, its content is 5% to 75% by weight.
In the case of pigment, the content is suitably 5% to 90% by weight.

Further, the film thickness of the colored recording layer of the present invention has a target optical density,
It can be determined by a method known to those skilled in the art depending on the type of colorant (dye, pigment, carbon blank) used in the colored recording layer and its content, but the thickness of the colored recording layer should be determined as much as possible within the allowable range. The thinner the film, the higher the developing power and the better the image quality.

Furthermore, a photosensitive composition is added to this colored recording layer within a range that does not impair film-forming properties. As the photosensitive component that can be added, there is used one that can cause a difference in solubility or swelling property in a developer between the exposed area and the unexposed area upon irradiation with actinic rays. So-called negative-positive type resins, in which the solubility or swelling property in developing solutions decreases in areas exposed to actinic rays, include photocrosslinkable photosensitive resins such as polyvinyl alcohol esterified with cinnamic acid; Examples include diazonium salts, condensates thereof, aromatic amide compounds, and photosensitive resins using photoradical polymerization or photoionic polymerization. On the other hand, naphthoquinone diazide compounds and the like are examples of so-called positive-positive type materials in which the portions exposed to actinic rays have increased solubility or swelling in a developer.

In order to produce the above-mentioned image-forming material, the above-mentioned material for forming the colored recording layer may be dissolved in a suitable solvent and applied onto the above-mentioned support.

As a solvent, water, methanol, ethanol, acetone, ethyl acetate, methyl cellosolve, ethyl cellosolve,
dioxane, methyl ethyl ketone, cyclohexanone,
Diethylene glycol monomethyl ether, γ-butyrolactone, tetrahydrofuran, methylene chloride,
Examples include ethylene chloride, dimethyl sulfoxide, dimethyl formamide, etc., and these can be used alone or in combination of two or more.

The image forming material according to the present invention produced in this manner is first imagewise exposed to actinic light.

Various light sources are used for imagewise exposure, 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.

The image-forming material imagewise exposed in this manner forms an image with a developer that does not dissolve the image area of the colored recording layer but can dissolve or swell the non-image area.

Next, the obtained colored image is superimposed on a transfer material, such as white printing paper such as art paper, coated paper, high-quality paper, synthetic paper, etc., and microwaves are applied to the transparent support using a high-frequency coil to form the colored image. The area is heated to transfer the colored image.

When creating a multicolor color proof, a colored image can also be formed on plain paper by repeating the above exposure, development, and transfer steps for the required number of colors.

〔Example〕

Examples will be given below, but the present invention is not limited thereto.

<Example 1> A colored photosensitive layer dispersion having the following composition was applied to the polypropylene surface of a support obtained by dry laminating a 25 μm thick polypropylene film on a 50 μm thick polyethylene terephthalate film using a wire bar to form a dry film. The coating was applied to a thickness of 1 μm and dried to produce four colored image forming materials.

Photosensitive resin (A) having the following structure 〇18O□H Ethyl cellosolve (EC) (1!Liquid surface) Black Cyan Magenta Yellow (A) 1.15
1.15 1.15 1.15 (B)
3.85 3.85
3.85 3.85 (EC)
42.8 39.6 40.
6 40.6 (Pigment) The obtained four-color image forming material was color-separated into a positive mask for each color (length between registration marks: 265 dragons in the vertical direction, 407 cranes in the horizontal direction).
50cm with 3KW metal halide lamp
After imagewise exposure from a distance of , the image was developed by immersing it in a 15-fold diluted solution of 5DP-1 (Sakura PS plate developer: manufactured by Konishiroku Photo Industry Co., Ltd.) for 30 seconds to obtain a four-color image.

(Image Transfer Process) Next, the previously obtained four-color images were laminated on art paper. First, the art paper and black color image are brought into close contact,
The color image was transferred onto art paper by microwave heating using a high frequency welder (trade name FDW-323 manufactured by Fuji Denpa Koki ■).

Subsequently, color images were transferred in the order of cyan, magenta, and yellow to obtain a color proofing sheet consisting of four colors on art paper.

The obtained color proof was good with no missing images and little color shift. The values of register mark deviation after four-color lamination are shown below.

Vertical direction (265 weight) Horizontal direction (407 mm) 20
Comparative Example 1 The image sheet obtained in Example 1 was used to transfer four color images onto art paper using a pair of nip rolls.

First, a black color image was brought into close contact with art paper and passed between a pair of nip rolls heated to 80° C. to transfer the color image onto the art paper. Subsequently, color images were transferred in the order of cyan, magenta, and yellow.

The results are shown in the table below.

Transferability Color shift in vertical direction (265 fins) Horizontal direction (407 dragons) Image loss 150 μm 200 μm The obtained color proofing sheet had image loss and large color shift.

[Effects of the Invention] As described above, according to the present invention, a good transferred image without color shift can be obtained.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views showing the method of the present invention in the order of steps.

Claims (1)

[Claims] (1) After imagewise exposure, an image forming material having a colored recording layer containing a colorant and a photosensitive composition on a support is developed to form a colored image, and this is transferred to a transfer material. In a method for forming an image: After obtaining a colored image, the colored image portion is transferred by high-frequency dielectric heating while the colored image is superimposed on a material to be transferred.