JPS63305349A - Transferred image forming method - Google Patents

Abstract

PURPOSE:To obtain a good transferred image having no color slurring by forming a base of polyethylene terephthalate subjected to an annealing treatment. CONSTITUTION:The base to be used for a method of subjecting an image forming material provided with a thermally weldable resin layer and coloring recording layer having a photosensitive compsn. in this order on the base to imagewise exposing, then to developing to form a colored image and transferring this image to a material to be transferred thereby receiving the transferred image, consists of the polyethylene terephthalate subjected to the annealing treatment. The color slurring after lamination of the 4 layers arises from a large thermal shrinkage rate of the base. A polyimide film, etc., are, thereupon, conceivable as the film having the low thermal shrinkage rate but these films are insufficient in terms of transparency, ease of handling, oil resistance, etc. Whereas, the polyethylene terephthalate film subjected to the annealing treatment is good in terms of all those mentioned above and obviates the color slurring at the time of heat transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transfer image forming method for obtaining color proofing sheets and the like when color proofing is performed as a pre-printing step in multicolor printing.

[Conventional technology]

For color printing, whether lithograph, letterpress or gravure, the halftone method is used and requires color-separated halftone dots, positive or negative plates.

It is generally known to use a color proofing sheet for color proofing, that is, a color proof, in order to save the labor and time of proof printing performed prior to actual printing.

Various proposals have been made regarding the layer structure and image (transfer image) forming method of this color proof, such as JP-A-47-41830, JP-A-60-28649,
There is one published in No. 61-186955. The layer structure of this colored image-forming material is such that a heat-fusible layer and a colored recording layer having a photosensitive composition are sequentially provided on a support.

In forming a transferred image in this case, the image-forming material is imagewise exposed to actinic rays, then developed to form a colored image, and then the colored image surface is superimposed on another transfer material and pressed. Alternatively, after being subjected to pressure and heat treatment, the support is peeled off from the heat-fusible layer and the colored image is transferred together with the heat-fusible layer to a transfer material.

Known examples of the support include two-wheel stretched polyethylene terephthalate film, acetate film, polyvinyl chloride film, polystyrene film, polypropylene film, and polyethylene film.

[Problem that the invention seeks to solve]

As mentioned above, when obtaining a transferred image, it is possible to use only pressure, but from the viewpoint of transferability, it is preferable to perform both pressure and heat. This thermal transfer is usually performed at a considerably high temperature. Therefore, the heat shrinkage rate of the support in the above example is large, and therefore the support undergoes large heat shrinkage during thermal transfer, resulting in color shift (so-called registration mark shift) in the image after laminating four colors (cyan, magenta, yellow, and black). ), and a good transferred image could not be obtained.

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

[Means for Solving the Problems] The above object is to provide an image forming material having a heat-fusible resin layer and a colored recording layer having a photosensitive composition on a support in this order, after imagewise exposure, development. In this method, a colored image is formed by forming a colored image, and the colored image is transferred to a material to be transferred to receive the transferred image.

[Specific structure of the invention]

The present invention will be explained in more detail below.

The main point of the present invention is to use an annealed polyethylene terephthalate film as the support for the colored image forming material. As mentioned above, the color shift after four-color lamination, that is, the registration mark shift, is caused by the large heat shrinkage rate of the support. Therefore, polyimide films and polycarbonate films may be used as films with excellent heat resistance and low heat shrinkage.
In contrast, annealed polyethylene terephthalate film is good in all of these aspects, and does not cause color shift during thermal transfer. The annealed polyethylene terephthalate film can be obtained by applying a predetermined temperature to a two-wheel stretched polyethylene terephthalate film for a certain period of time, but it is also possible to use an annealed polyethylene terephthalate film that is already commercially available.

Such a support may be used as it is, but in order to improve the transferability of the image after image formation, it may be subjected to a release treatment with an appropriate oil-repellent material, or may be provided with an undercoat layer.

Examples of oil-repellent substances include silicone resins, fluororesins, and fluorosurfactants, and as undercoat layers,
Examples include alcohol-soluble polyamides, alcohol-soluble nylons, blends of partially esterified resins of copolymers of styrene and maleic anhydride, and methoxymethylated nylons, polyvinyl acetate, polyacrylates, polymethyl methacrylates, and co-acrylates. Adhesion to transparent supports such as polymers, polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl butylade, cellulose acetate phthalate, methylcellulose, ethylcellulose, cellulose diacetate, cellulose triacetate, and polyvinyl alcohol. Examples include weak ones.

The heat-fusible resin layer used in the present invention is transparent and non-adhesive at room temperature, but can be heat-fusible in the temperature range of 80°C to 150°C, considering that it is also used in an overlay method. Preferably.

As such resins, the following resins are described in JP-A-47-41830.

Polyolefins such as polyethylene and polypropylene.

Ethylene copolymers such as ethylene and vinyl acetate, ethylene and acrylic ester, and ethylene and acrylic acid.

PVC.

Vinyl chloride copolymers such as vinyl chloride and vinyl acetate.

Polyvinylidene chloride.

Vinylidene chloride copolymer.

polystyrene.

Styrene copolymers such as styrene and maleic anhydride.

Polyacrylic acid ester.

Acrylic ester copolymers such as acrylic ester and vinyl acetate.

Polymethacrylic acid ester.

Methacrylate ester copolymers such as methyl methacrylate and vinyl acetate, and methyl methacrylate and acrylic acid.

Polyvinyl acetate.

Vinyl acetate copolymer.

Vinyl butyral resin.

Polyamide resins such as nylon, copolymerized nylon, and N-alkoxymethylated nylon.

synthetic rubber.

Chlorinated rubber.

Polyethylene glycol.

Polyvinyl alcohol hydrozine phthalate.

Cellulose derivatives, cellulose acetate phthalate,
Cellulose acetate succinate.

Sheratsk.

wax.

Among these resins, polystyrene resins are superior in terms of transferability to transfer materials (art paper, etc.), exposure to light, scumming in non-image areas after development, and the like.

The thickness of the heat-fusible resin layer is suitably in the range of 1 to 20 microns, particularly preferably in the range of 2 to 10 microns.

The thickness of the heat-fusible resin layer is determined by the colored recording layer or
A uniform and better transferred image can be obtained by making the thickness equal to or greater than the combined thickness of the colored (recording) layer and the non-colored recording layer.

A colored recording layer is provided on the heat-fusible layer. As described later, this colored recording layer may have a two-layer structure consisting of a colored layer and a photosensitive layer, or a colored recording layer and a photosensitive layer.

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

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 polymer compounds suitably used for the colored recording include acrylic acid, methacrylic acid, alkyl esters or sulfoalkyl esters thereof, phenol resins, polyvinyl butyral, polyacrylamide, ethyl cellulose, cellulose acetate/butyrate, and propion acetate. Acid cellulose, cellulose acetate, benzyl cellulose,
Other examples include cellulose derivatives such as cellulose propionate, polystyrene, polyvinyl chloride, chlorinated rubber, polyisobutylene, polybutadiene, polyvinyl acetate, and copolymers thereof, cellulose acetate, cellulose propionate, and cellulose acetate phthalate.

Dyes and pigments are added to the colored recording layer as coloring substances. 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. Zero-order examples, also used, are some of the many pigments and dyes known in the art.
CC, I means color index) Victoria Vinia Blue (C, I 42595) Auramine 0 (C, I 41000) Rhodamine 6GCP
(C, 145160) Rhodamine B (C, I 451
70) Safranin 0K70:100 (C,I 5024
0) Elioglau:> NX (C, I 42080)
First Blank HB (C, I 26150) Arashi 1
201 Lionor Yellow (C, I 21090) Lionor Yellow GRO (C, I 21090) Shimla Fast Yellow 8GF (C, I 21105)
Benzidine Yellow 4T-5640 (C, I 2109
5) Shimla Firth Trend 4015 (C, I 1
2355) Lionor Red 7B4401 (C, 11
5830) First Gen Blue TGR-L (C, I
74160) Lionolbu/I/-SM (C,I
26150) Mitsubishi Carbon Black MA-100 Mitsubishi Carbon Black 1130.140.1150 The colorant/binder ratio of the colored recording layer used in the present invention takes into consideration the target optical density and the removability of the colored recording layer to the developer. can be determined by methods known to those skilled in the art. For example, in the case of dyes, the content ranges from 5% to 75% by weight.
%, and in the case of pigments, the appropriate content is 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 black) 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 component can also be 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. The so-called negative-positive type, in which the solubility or swelling property in the developing solution decreases in the area exposed to actinic rays, is a photocurable photosensitive resin typified by polyvinyl alcohol esterified with cinnamic acid. , diazonium salts, condensates thereof, aromatic amide compounds, etc. Furthermore, photosensitive resins using photoradical polymerization or photoionic polymerization can also be used. On the other hand, so-called positive
Examples of positive types include naphthoquinone diazide compounds.

The image forming material according to the present invention can also be constructed by providing a photosensitive layer made of a photosensitive composition on the above-mentioned colored recording layer. Note that this photosensitive layer is essential when the above-mentioned photosensitive component is not added to the colored recording layer. That is, it is necessary to form a photosensitive layer on the colorant layer.

As photosensitive compositions for forming such a photosensitive layer, various materials have been known, and commercially available products are also easily available. The photosensitive composition used undergoes a chemical change in its molecular structure in a short period of time when exposed to actinic rays, changing its solubility in solvents, and when a certain type of solvent is applied. is a monomer whose exposed part or unexposed part is dissolved and removed,
Includes all compounds such as prepolymers and polymers. Examples of photosensitive compositions that can be used include photocrosslinkable photosensitive compositions, such as those made by esterifying polyvinyl alcohol with cinnamic acid, which are so-called negative-positive type compositions in which the solubility of exposed areas decreases. There are resin systems, systems in which diazonium salts and their condensates, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, etc. are mixed, and systems in which aromatic acid compounds are used as photocrosslinking agents and are mixed with binders such as cyclized rubber. Photosensitive resins using photoradical polymerization or photoionic polymerization can also be used. Further, as a so-called positive-positive type resin that increases solubility in the exposed area, there is a photo-soluble resin system typified by a combination of naphthoquinone diazide and novolak resin.

Commercially available photosensitive compositions include "KPR'" and "KOR" manufactured by Eastman Kodak Company in the United States.

KMII! R”, “AZ-340” manufactured by Shipley, USA
, ``AZ-119°'', ``AZ-1350'' manufactured by Tokyo Ohka Co., Ltd. ``TPR'', ``Okaresist'', Fuji Yakuhin type ``FPPR'', etc., and all of these can be used.

In order to produce the image forming material of the present invention, the aforementioned heat-fusible resin layer components are dissolved in a suitable solvent, coated on the aforementioned transparent support and dried, and then the aforementioned colored recording layer components are dissolved in an appropriate solvent. A solution of a suitable solvent may be applied onto the heat-fusible resin layer.

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 way is treated with a solvent that does not dissolve the image area of the colored recording layer and the photosensitive layer but dissolves the non-image area, thereby removing the non-image area of the photosensitive layer and removing the resist. By forming an image and using a solvent that dissolves or swells the colored recording layer and does not dissolve the resist image on the photosensitive layer as a developer, the exposed portion of the colored recording layer is removed by removing the photosensitive layer. The photosensitive layer and the colored recording layer can be removed by dissolving or rubbing them off, or by treating with a solvent that does not dissolve the image area of the photosensitive layer but can dissolve and/or swell both the non-image area of the photosensitive layer and the colored recording layer. The non-image areas of the layer may be simultaneously dissolved or rubbed away to form an image.

Although the selection of solvents is important for developing the photosensitive layer and the colored recording layer, the present invention can be carried out by applying conventionally known techniques in both cases.

Next, the obtained colored image is transferred to printing paper such as synthetic paper. Specifically, since plain paper has a problem with thermal stability, synthetic paper with good thermal stability is used as the transfer material, a colored image is superimposed on it, and the paper is passed through a laminator under heat and pressure. The colored image is transferred to the synthetic paper by heating and pressure during the passage.

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

〔Example〕

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

<Example 1> A commercially available annealed polyethylene terephthalate film was used as the support.

Annealed PET; Lumirror (annealed product) 75μ-
An undercoat layer coating solution (manufactured by Toshikusha) having the following composition was coated on an annealed polyethylene terephthalate film to a dry film thickness of 7 μm to prepare a support having a heat-fusible resin layer.

Number average molecular weight 2.500 4 parts toluene
20 parts Next, four colors of positive colored recording layer dispersions having the following compositions were prepared and coated to give a dry film thickness of 1 μm.

Photosensitive resin (A) having the following structure 11 Ethyl cellosolve (EC) (Liquid preparation table) Black Diazi Magenta Ye II
-(A) 1,15 1,
15 1,15 1.15(B)
3.85 3.85 3.85
3.85 (E C”) 42
．． 8 39.6 40.6 40.6 (pigment) The obtained four-color image forming material was subjected to a color separation positive mask for each color (length between registration marks: 265 m in the vertical direction, 407 m in the horizontal direction)
) and 50c with 1/3 metal halide lamp.
After imagewise exposure from a distance of m, 5DP-1 (Sakura ps
Plate developer: A 15-fold diluted solution (manufactured by Konishiroku Photo Industry Co., Ltd.) was used to develop the plate for 30 seconds to obtain a four-color image.

The size of the obtained image sheet is shown in FIG.

The symbol T is a dragonfly.

Next, the black image was passed through a pair of nip rolls that were in close contact with image receiving paper (Peach coated paper WE-110J manufactured by Nisshinbo Co., Ltd. and heated to 110°C) to transfer the color image to the image receiving paper. Color images were transferred in the order of magenta and yellow to obtain a color proofing sheet consisting of four colors on image-receiving paper.

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

Vertical direction (265 servings) Horizontal direction (407 cranes) 50μ
Comparative Example 1> The same procedure as in Example 1 was carried out except that a commercially available polyethylene terephthalate film was used as the support.

The registration mark deviation at this time is shown below.

Vertical direction (265m) Horizontal direction (4071M) 24
0μ 290μ The obtained color proof has registration mark misalignment (
The color shift) was large, and the clarity of the transferred image was reduced.

〔Effect of the invention〕

As described above, according to the present invention, a high-quality transferred image without color shift can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the shape of the colored image forming material obtained in the example. T...Dragonfly diagram 1

Claims (1)

[Claims] (1) After imagewise exposure, an image-forming material comprising a heat-fusible resin layer and a colored recording layer having a photosensitive composition in this order on a support is developed to form a colored image, and this is coated. A method of forming a transfer image by transferring it to a transfer material, wherein the support is made of annealed polyethylene terephthalate.