JPH02228664A - Image forming material - Google Patents

Abstract

PURPOSE:To form a photosensitive layer consisting of uniform coloring agents by forming a protective film of a polyethylene (PE) film which is subjected to an irradiation treatment of electron rays and has <=0.1mm thickness. CONSTITUTION:The photosensitive layer consisting of plural layers is formed and further, the protective film is formed on the photosensitive layer. The protective film is formed of the PE film which is subjected to an irradiation treatment of the electron rays and has <=0.1mm thickness. The image forming material is formed by sticking the photosensitive layer formed on a transparent base and the photosensitive layer formed on the protective film to each other. The transfer of images to an image acceptor, such as paper is, therefore, possible by subjecting the image forming material to image exposing, then rupturing and peeling the photosensitive layer nearest the transparent base by utilizing the difference in the tacky adhesiveness in the transfer of the exposed part and unexposed part of the photosensitive layers. The particularly uniform densities are obtd. in this way.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a material for forming an image.

More specifically, it is an image-forming material that uses the difference in adhesiveness between the exposed and unexposed areas of the photosensitive layer to form images in a single color or multi-color superimposition, and is a transfer product that is completely similar to a printed material as a 9-color proof print prepress blue. The present invention relates to high quality image forming materials that can be obtained.

(Prior Art) Conventionally, in the printing industry, it has become more and more popular to use one-proof printing or bripress proofing as a means of checking the finished color of the final printed matter before printing. It is being

Prepress proofing has the advantage of being able to predict the final printed product without using printing ink, and can be used with overlay or subprinting methods depending on the final image quality and various objectives in the plate-making and printing processes. etc. are used accordingly.

In the overlay method, there is a photosensitive layer containing colorants corresponding to each color separation mask on a transparent base film.

This film and mask are brought into close contact, exposed to light, developed, and then the respective films are superimposed and calibrated.

Nowadays, new methods that do not use a developing solution or developing gas are being considered, such as in Japanese Patent Application Laid-Open No. 63-188088, but this method requires the use of transmitted light, so it is low cost but , the delicate color balance and gradation are impaired from the beginning, and it is not possible to judge the final finish of the printed matter as a reflective object.

Unlike the overlay method, the subprint method provides a hard copy, so it has high utility value and has been used to print several copies on a single support as described in U.S. Pat. There is a method in which photopolymer photosensitive layers are laminated to sequentially form separate color images. In this example 2
It uses color toner as a coloring substance, and can be said to be an excellent prepress proof in that it faithfully reproduces the original mask, but as the photosensitive layer is laminated, the diffused reflection in non-image areas is extremely large, making it difficult to match the actual printed material. Compared to this, the gloss is significantly higher, so the texture is quite different. In addition, the cured layer after exposure to light is brittle and cracks are likely to form on the surface depending on the storage conditions. Moreover, coloring using color toners causes the color toners to scatter, which is not desirable from the viewpoint of work hygiene.

Also, 2 Japanese Patent Publication No. 59-97410, 61-1
There is also a bripress proof that can be used for both the overlay method and the subprint method as described in Japanese Patent No. 88537. The advantage of this method is that depending on the purpose of use, if you simply want to check characters, etc., you can check only with the overlay.

It is highly versatile in that if you want to obtain a hard copy for checking delicately colored parts such as patterns, you can just transfer it to the object to be transferred. However, since a developing step using an organic solvent is required, there is a drawback that the working environment is poor. Furthermore, although the resulting image can be transferred to any type of transfer object, a photosensitive transparent intermediate layer is interposed between the transfer object and the colored photosensitive layer, so that the transfer object and the colored photosensitive layer do not interact with each other. are glued together. Due to the presence of this layer, one reflected light is diffusely reflected, resulting in a finish that is quite different from the actual printed matter, and the density of the obtained transfer product tends to be lower than that of the actual printed matter. The subprint prepress blue method using a photopolymer photosensitive layer as described above has a particularly low density of black ink, and considering that many recent printed materials have had the undercolor removed using electronic platemaking technology, it is difficult to achieve a good finish. Compared to the actual print, the bristle press proof ends up lacking in density.

Therefore, using a sub-print image forming material that does not require a developing process is a useful method in terms of workability and safety. At best, the density and gloss of the resulting images are different from those of printed matter using original ink, and the finished quality is also inadequate.

(Problems to be Solved by the Present Invention) The present inventors formed a photosensitive layer containing a dye and/or pigment on a transparent support, exposed it to two images, and exposed and unexposed areas of the photosensitive layer. An image forming material that causes a difference in tackiness during transfer and transfers an image to an image receptor such as paper, is obtained by transferring the image to the image receptor by cohesive failure of the photosensitive layer between roll nibs. It was discovered that Bripress Proof is completely different from conventional prepress proofs in that it reproduces images and textures that are exactly the same as actual printed matter because there is no layer such as an adhesive layer between the printing material and the image forming material. Ta.

However, when the colorant contained in the photosensitive layer is black or the like, more active light rays required for forming one image are absorbed compared to other colors, so if you want to obtain a transfer with the required density, , it required more actinic light than other colors and took two hours longer, resulting in the loss of the characteristics of simple calibration. To prevent this.

This is a simple proofing method in which the dye or pigment concentration of the colored photosensitive layer formed on the transparent support is lowered to speed up the curing speed, but the density of the resulting prepress proof is low, so it still tends to differ from the actual printed matter. there were.

At least four types of materials, yellow, magenta, cyan, and black, are required to be used as a prepress color proof material, and the amount of active light required for image formation is particularly high for ink and black compared to other colors. 9. Since the image formation exposure amount is smaller and the transfer density is higher, since the reflection density required for transfer is not sufficient.

Image-forming materials have been desired.

In order to solve this problem, we have found a material that can form a stable image with high density by first forming a plurality of photosensitive layers. However, when forming the photosensitive layer on the protective film, the polyethylene film serving as the protective film swells due to the organic solvent of the photosensitive layer, resulting in a drawback that a uniform colorant photosensitive layer cannot be obtained.

[Structure of the invention]

(Means for Solving the Problems) The present invention contains a dye and/or pigment in at least one layer on a transparent support. A photosensitive layer consisting of multiple layers is formed, and a protective film is further placed on top of the photosensitive layer, and two images are exposed.The difference in tackiness between the exposed and unexposed areas of the photosensitive layer results in one sheet of paper being formed. In an image forming material capable of transferring an image to an image receptor such as the above, the protective film is a polyethylene film having a thickness of 0.1 mm or less and subjected to electron beam irradiation treatment.

Furthermore, two image-forming materials are formed on a transparent support and have a photosensitive layer.

The photosensitive layer formed on the protective film is created by bonding the photosensitive layers together and exposed to two images, and the difference in tackiness in the transfer of the exposed and unexposed areas of the photosensitive layer is transferred to the transparent support. The present invention relates to an image-forming material that is capable of transferring an image to an image receptor, such as a piece of paper, by breaking and peeling off the nearest photosensitive layer.

Further, the protective film is stretched after electron beam irradiation treatment, and the thickness of the protective film is from 0.02 mm to 0.1 mm.
The imaging material is in the range of mm.

The present invention uses a plurality of photosensitive layers in the image forming material, so the amount of actinic light required to form the image is much smaller than that of the past, and is equivalent to or more than that of the actual printed matter. If the material is designed so that the photosensitive layer closest to the transparent support has the lowest softening point, the softening point will be lower at the time of fracture transfer. Since the lower layer is selectively broken, the entire photosensitive layer on the other side that is in contact with the photosensitive layer is transferred. This means that the higher the color density of the other photosensitive layer, the higher the transfer density.

There are two possible ways to create this imaging material. One is to form a colored photosensitive layer with a low softening point that can be broken and peeled off on a transparent support, and then.

Another colored photosensitive layer is formed on top of that photosensitive layer.

This is an overprinting method in which the desired image forming material is obtained by laminating a protective film. The other method is to form a colored photosensitive layer with a low softening point that can be broken and peeled off on a transparent support. On the other hand, another photosensitive layer with high transfer density is formed on the protective film. Then, there is a bonding method in which a desired image forming material is obtained by laminating the photosensitive layers so that they are in contact with each other.

The present invention provides a material capable of obtaining a printing density equivalent to that of ordinary printed matter, particularly a uniform density, on an image receptor such as a piece of paper. Furthermore, the present invention provides a material that can be imagewise exposed with the same amount of actinic light as other colors without impairing high reflection density.

To achieve this purpose, as a protective film.

It uses polyethylene film treated with electron beam irradiation.

For example, in the method of laminating two photosensitive layers, a photosensitive layer is formed on a transparent support and a protective film, and the photosensitive layer and the backing are laminated. When treated, the crosslinking density increases compared to an untreated film, so that it does not swell in the organic solvent contained in the photosensitive outer layer solution, and a uniform and even colored photosensitive layer can be formed on the protective film.

When the photosensitive layer is composed of a plurality of layers, it is preferable to transfer by breaking the layer closest to the transparent support.

Since the other colored photosensitive layer formed on the protective film side is completely transferred to the image receptor, the amount of dye or pigment in the first colored photosensitive layer can be increased.

Color density can be increased. Moreover, according to this method, there is no problem even if the dye or pigment is of another color.

In addition, if the film is stretched after electron beam irradiation treatment,
Since the solvent resistance can be improved and appropriate rigidity can be provided, coating is easier than using only electron beam irradiation.

Furthermore, the releasability of the protective film from the colored photosensitive layer after one image exposure is not impaired, and it is possible to prevent the formation of pinholes on the image receptor due to the residue of the protective film peeled off during transfer.

If a high-density photosensitive layer can be formed smoothly and uniformly on a protective film with these physical properties, it will be possible to form a colored photosensitive layer with a low softening point on a transparent support.

The image-forming material of the present invention can be produced by laminating the photosensitive layers with their surfaces in contact with each other.

The image forming material of the present invention is substantially composed of a transparent support, a plurality of photosensitive layers, and a protective film.

In particular, the protective film is one that has been subjected to electron beam irradiation treatment.

The equipment used for electron beam irradiation.

High energy type with an area of 5Mev or more, 0°3
A medium energy type of ~5 MevO and a low energy type of 0.3 Mev or less can both be used, and are selected depending on the thickness, material, etc. of the film to be irradiated.

This protective film is a polyethylene film, and a polyethylene film is preferable from the viewpoints of film rigidity, oxygen permeability, stretch ratio 1 surface smoothness, and peeling of the adhesive colored layer.

How to use the image forming material made in this way is as follows:
The transparent support side of this image forming material is brought into close contact with the image surface of the mask original plate, image exposure is performed from the mask side, the first mask original plate is removed, the protective film is removed, and the photosensitive layer and the transfer target are heated between nip rolls. By transferring, it is possible to obtain a transfer that is exactly the same as the printed matter.

As this transparent support, a material which is stable against heat, chemical light, etc., and which sufficiently transmits actinic light is suitable. Examples include films or sheets of cellulose acetate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate polypropylene, and the like. Particularly preferred is a polyethylene terephthalate film or sheet.

In particular, a polyethylene terephthalate film or sheet is preferred from the viewpoints of transparency, thermal stability, two-dimensional stability, and the like.

Further, the transparent support or the protective film may be subjected to conductive treatment in order to remove static electricity generated when the protective film is peeled off.

The photosensitive layer according to the present invention is 2N or.

It consists of three or more layers, and at least one layer contains a colorant. A coloring agent may be contained in all the photosensitive layers.

Examples of materials that can be applied to the photosensitive layer of the image forming material of the present invention include:

(a) A photopolymerizable compound and a colorant (sometimes no colorant is included) (b) A photopolymerizable compound, a thermoplastic resin, a colorant, etc.; Polymerization accelerators, thermal polymerization inhibitors, resin plasticizers, R-material dispersants, etc. are used in combination.

Photopolymerizable compounds include monomers and polymers.

At least one selected from prepolymers is applied.

The photopolymerizable compound is not particularly limited, but preferably one that can plasticize the thermoplastic resin at room temperature.

Typical compounds include 2-hydroxyethyl (meth)acrylate, ethylene glycol diacrylate,
Diethylene glycol diacrylate 1.6 hexanediol di(meth)acrylate trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, etc.
One type of these ethylenically unsaturated compounds may be used, or two or more types may be used as necessary.

As the thermoplastic resin (organic polymer binder), a thermoplastic, non-photopolymerizable polymer that has excellent compatibility with photopolymerizable compounds can be used. For example, polyvinyl chloride,
Poly(meth)acrylic acid ester.

Epoxy resin, polyurethane resin, cellulose derivative,
(For example, ethylcellulose, cellulose acetate.

There are synthetic rubbers such as (nitrocellulose) vinyl chloride vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, diallyl phthalate resin, butadiene-acrylonitrile copolymer, etc. Depending on the required physical properties, these thermoplastic materials can be , or two or more types may be included.

As photopolymerization initiators, we mainly use those with low absorption in the visible light region, those with good compatibility with photopolymerizable compounds, and those with photochemically intersystem cross quantum efficiency close to 1.
Preferred examples include benzophenone, benzoin ethyl ether, benzyl dimethyl ketal, azobisisobutyronitrile, 2-chlorothiozanzone, 2-methylthiozanzone, 2-ethylthiozanzone, and 2-isoprobylthiozanzone.

Examples include 4°-isopropyl-2-hydroxy-2-methylpropiophenone, and a photopolymerization accelerator may be used in combination to improve the photopolymerization initiation efficiency.

As this photopolymerization accelerator, aromatic-aliphatic tertiary amines and the like are known. For example, Michler's ketone, 4.4'
-Bisdiethylaminobenzophenone and the like. Since some promoters may cause yellowing, they are selected in consideration of promoting efficiency, yellowing, compatibility with the initiator, and the energy and wavelength range of the actinic rays to be used.

Most thermal polymerization inhibitors are aromatic derivatives. What is important in selecting a thermal polymerization inhibitor is the amount added and compatibility; the amount must be such that it does not interfere with the generation of radicals for photopolymerization, and at the same time it must suppress radicals thermally. Those commonly used so far include hydroquinone, p-methoxyphenol, t-butylcatechol, and pyrogallol. However, the present invention is not controlled by the combination of non-aromatic compounds.

The colorant applied to the photosensitive layer is an organic pigment.

Conventionally used dyes and pigments such as dyes and carbon black can be used. It is also possible to mix several dyes and pigments to obtain the required hue.

The pigment or dye added to the photosensitive layer is suitably 5 to 50% of the total solid content, more preferably 5 to 50% of the total solid content.

9-20% is preferred.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto. Example "Central part" refers to parts by weight.

Example 1 In an autoclave, hexahydrorthophthalic anhydride and allyl alcohol were combined in the presence of triethylamine for 1
After reaction at 30° C. for 5 hours and dehydration, a diallyl hydrogenated orthophthalate monomer with a conversion rate of 91% was obtained.

This diallyl hydrogenated orthophthalate monomer was polymerized at 170°C using benzoyl peroxide and dibutyltin laurate as catalysts to give a weight average molecular weight of about 15,000.
A prepolymer having a number average molecular weight of about 7,850 was obtained.

(Colored photosensitive layer formed on transparent support) A photosensitive layer solution having the following composition was prepared.

The above diallyl hydrogenated orthophthalate prepolymer 14
．． 34 parts Pentaerythritol trimethacrylate 6.14 parts Bisphenol A modified (EO) diacrylate 1.38 parts
Part 2.4.6-) Limethylbenzophenone 0, 70 parts EAB (manufactured by Hodogaya Chemical Co., Ltd.) 0.40 parts MA-7 (manufactured by Mitsubishi Kasei Corporation) 0.32 parts R-52 ( Hoechst Jahan Co., Ltd.) 0.11 parts Methyl ethyl ketone 60.0 parts Toluene 38.0 parts Methyl cellosolve 12.5 parts Isopropyl alcohol 1.3 parts 1
2μ) to a dry film thickness of 0°5μ.

[Colored photosensitive layer formed on protective film] A photosensitive layer solution having the following composition was prepared.

Diallylisophthalate prepolymer 22.0 parts (manufactured by Osaka Soda Co., Ltd.) KAYARAD-DPHA 7.0 parts (manufactured by Nippon Kayaku Co., Ltd.) Benzophenone (manufactured by Daiichi Kasei Co., Ltd.) 0.5 part EA
B (Hodogaya Chemical Co., Ltd.) 0.2 parts MA-7 (Mitsubishi Kasei Co., Ltd.) 3.0 parts R-52 (Hoechst Java Co., Ltd.) 1.0 parts Methyl ethyl ketone
40.0 parts toluene
10.0 parts xylene
10.3 parts of this photosensitive layer solution was coated onto a biaxially stretched high-density polyethylene film (thickness: 40 .mu.m) as a protective film to give a dry film thickness of 1.5 .mu.m.

The film used in this experiment was subjected to an electron beam dose equivalent to 10 Mrad (the equipment used -
Area beam type electron beam irradiation device/Curetron/Form E
BC-200-20-30 type 9th Shin High Voltage Co., Ltd.'! M was used. ) to improve the crosslinking density.

The colored photosensitive layer formed on the transparent support and the colored photosensitive layer formed on the protective film were laminated together using a laminator so as to be in contact with each other to obtain the desired image forming material.

The transparent support side of this image forming material was brought into close contact with the silver salt side of the original positive mask, and the UV printer HMW-201KB was used.
(manufactured by Oak Seisakusho Co., Ltd.) and applied active light at 50 mj/cm2. When this image forming material and the original positive mask were peeled off, and the protective film was further peeled off, the colored photosensitive layer coated on the protective film had completely migrated to the transparent support side, and no residue remained on the protective film side. Ta. Transferring was carried out by using a Fast Laminator 8B-700 special type (manufactured by Taisei Laminator Co., Ltd.) to bring the double-sided art paper, Shigure Art 110 kg (manufactured by Mitsubishi Paper Mills Co., Ltd.) into close contact with the image forming material from which the protective film had been peeled off. , pressure 4 kg
/cm2, a passing speed of 35 cm/min, and a roller surface temperature of 70''C. Transfer was performed using a nip between rollers.

The removability of this protective film is very good.

The coated surface of the colored photosensitive layer was uniform, and the solid density of the obtained transfer was approximately 2.1 in terms of optical reflection density, making it possible to obtain a transfer whose texture was exactly the same as that of an actual black ink print. Ta.

Example 2 An electron beam dose of 10M was applied to an unstretched low-density polyethylene film (manufactured by Tamabori Co., Ltd., N-5l-P (thickness 40μ)).
rad was given in place of the protective film of Example 1, and an image forming material was prepared by the method of Example 1.
Image exposure and transfer were performed.

As expected, the removability of the protective film was very good, and the coated surface of the colored photosensitive layer was uniform, and the optical reflection density of the transferred material was 2.1.
Met.

Comparative Example 1 Unstretched low-density polyethylene film (manufactured by Tamapoly Co., Ltd., N-5) that was not subjected to electron beam irradiation treatment as a protective film
1-P (thickness 40μ)).

An image forming material was prepared in the same manner as in Example 1.

However, when forming a colored photosensitive layer on a protective film,
The film swelled in the organic solvent and a uniform coated surface could not be obtained.

Comparative Example 2 The material of the protective film is the same as in Example 1, but the thickness is 1
An image forming material having a thickness of 59 μm was prepared, and the rest was carried out in the same manner as in Example 1 to form an image forming material.

At this time, although a uniform coated surface can be obtained on the protective film, when the protective film is peeled off, the adhesive force with the photosensitive layer 9 is too strong and the photosensitive layer adheres to the protective film, making it ineffective as a protective film. It has been found that there is a range of suitable thicknesses for use.

Comparative Example 3 The photosensitive layer of Example 1 (the photosensitive layer formed on the protective film) was formed on a transparent support to a dry film thickness of 1.5μ, and an unstretched low-density polyethylene film (N-
51-P, thickness 40 μ) was laminated and exposed to actinic light of 50 mj/cm” in the same manner as in Example 1, but stains occurred due to insufficient curing of the photosensitive layer during transfer. .

The solid density of the transcript at this time was approximately 1.3.

Comparative Example 4 When active light of 500 mj/cm was applied to the image forming material of Comparative Example 3, a stain-free transfer could be obtained.The solid density of the obtained transfer was about 1.3. Ta.

Claims (1)

[Claims] 1. A photosensitive layer consisting of multiple layers, at least one layer containing a dye and/or pigment, is formed on a transparent support, and a protective film is further provided on the photosensitive layer. , an image-forming material that can be image-exposed and transferred to an image receptor such as paper due to the difference in tackiness between the exposed and unexposed areas of the photosensitive layer, when the protective film is irradiated with an electron beam. An image-forming material characterized in that it is a treated polyethylene film having a thickness of 0.1 mm or less. 2. The image-forming material is made by laminating the photosensitive layers formed on a transparent support and the photosensitive layer on a protective film, and then imagewise exposed to light to form a photosensitive layer in the photosensitive layer. The difference in adhesion between the exposed and unexposed areas can be determined by breaking and peeling the photosensitive layer closest to the transparent support.
An imaging material according to claim 1, characterized in that it is an imaging material capable of transferring an image to an image receptor such as paper. 3. The image forming material according to claim 1 or 2, wherein the protective film is stretched after being subjected to electron beam irradiation treatment. 4. The thickness of the protective film is 0.02 mm to 0.1 mm.
The image forming material according to any one of claims 1 to 3, characterized in that it is in the range of mm.