JP2003295422A - Photosensitive printing plate precursor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive printing plate precursor excellent in fine pattern reproducibility in plate making and in printing. <P>SOLUTION: (1) The photosensitive printing plate precursor comprises at least a support, a photosensitive resin layer, a coating layer and a cover film, wherein the coating layer contains a light absorbent having absorption in an actinic ray region of the photosensitive resin layer and having an average molecular weight of ≥1,000. (2) In the photosensitive printing plate precursor described in the above (1), the light transmittance of the coating layer to light of 360 nm wavelength is 50-99%. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive printing original plate used for producing a relief plate for printing.

[0002]

2. Description of the Related Art Usually, a photosensitive printing original plate used for a relief plate for printing has a support layer, a photosensitive resin composition layer, a coating layer,
It consists of a cover film, and is used by removing the cover film at the time of use.

The photosensitive printing original plate from which the cover film has been removed is irradiated with an actinic ray through a negative film (or a positive film) having a transparent image area to cure the photosensitive resin layer in the exposed area, and then in the unexposed area. It is widely known that a relief plate for printing is prepared by dissolving and removing the photosensitive resin layer with an appropriate solvent.

Recently, a demand for a photosensitive printing original plate used as a relief plate for printing has been progressing toward the reproduction of finer patterns, and the line width of the blank pattern is 30 μm.
There is a demand for printing reliefs as fine as m. However, a relief printing plate material for printing using a photosensitive resin composition cannot sufficiently meet this demand, and a photosensitive printing original plate capable of reproducing a fine pattern in plate making and printing cannot be obtained.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and it is an object of the present invention to provide a photosensitive printing original plate excellent in reproducibility of a fine pattern during plate making and printing. It is what

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to solve the above-mentioned problems, and as a result, have been involved in the reproducibility in plate making and printing of a fine pattern in the coating layer of the photosensitive printing original plate. That is, the present invention was finally completed. That is, the present invention is at least a support,
A photosensitive printing original plate having a photosensitive resin layer, a coating layer and a cover film, wherein the coating layer contains a light absorber having an average molecular weight of 1,000 or more and having an absorption in an actinic ray region of the photosensitive resin layer. A photosensitive printing original plate characterized by the above.
The light transmittance of the coating layer is 50% for light with a wavelength of 360 nm.
It is the said photosensitive printing original plate which is -99%.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The coating layer characteristic of the present invention is a layer provided to prevent the adhesion of a negative to a photosensitive resin layer and is referred to as a slip coat layer, a peeling layer, an anti-adhesion layer or the like. It may be done. Examples of constituent materials include polyamide, polyvinyl alcohol and its derivatives, and cellulosic polymers. Any of these may be used alone or in combination of two or more. In addition to the above components, a general coating layer contains inorganic fine particles such as silica, organic fine particles obtained by three-dimensionally internally crosslinking polystyrene or an acrylic monomer, a surfactant, and a polyhydric alcohol, if necessary. Has been done.

The light absorber contained in the coating layer used in the present invention has a molecular weight of 1,000 or more, preferably 5,000 or more, and more preferably 10,000 or more. When the molecular weight is less than 1,000, the light absorber migrates to the photosensitive resin layer, which reduces the actinic ray absorbability of the coating layer, which is not preferable. As the light absorber having a molecular weight of 1,000 or more, a substance that is compatible with and dispersed in the coating layer constituent is preferable. For example, a fine particle light absorber having a radical-polymerizable compound such as acrylic acid ester and styrene and a benzophenone skeleton or a benzotriazole skeleton, and a radical-polymerizable ultraviolet absorber copolymerized by emulsion polymerization. Alternatively, a light absorber obtained by graft-adding a benzophenone-based or benzotriazole-based compound via an epoxy compound to polyvinyl alcohol, a cellulose-based polymer or the like. Alternatively, a benzophenone-based or benzotriazole-based light absorber which is compatible with the coating layer composition and has an active hydrogen at the molecular end and having a molecular weight of 1,000 or more via a diisocyanate may be mentioned, but is not limited thereto. Not a thing.

The actinic ray transmittance of the coating layer of the present invention is 3
50% to 99%, preferably 70 for 60 nm light
˜95%, more preferably 80-90%. Fifty
If it is less than 100%, the amount of actinic rays reaching the photosensitive resin composition layer is too small and the reproducibility of the relief is lowered, and if it exceeds 99%, the actinic rays pass by and the fine pattern cannot be reproduced, which is not preferable.

The thickness of the coating layer is 0.1 to 10 μm, preferably 0.1 to 2 μm, particularly preferably 0.1 to 1 μm. If the thickness is less than 0.1 μm, adhesion with a negative will occur, and if it exceeds 10 μm, the resolution of the relief will decrease, which is not preferable.

The photosensitive resin layer in the present invention comprises a known soluble synthetic polymer compound, a photopolymerizable unsaturated compound (hereinafter,
(Also referred to as a cross-linking agent) and a photopolymerization initiator. It may also contain additives such as plasticizers, thermal polymerization inhibitors, dyes, pigments, UV absorbers, perfumes or antioxidants.

In the present invention, known soluble synthetic polymer compounds can be used as the soluble synthetic polymer compound.
For example, polyether amide (for example, JP-A-55-79437)
Gazette, etc.), polyether ester amide (eg JP-A-58-113537 etc.), tertiary nitrogen-containing polyamide (eg JP-A-50-76055 etc.), ammonium salt type tertiary nitrogen atom-containing polyamide (eg JP-A-53-36555), addition polymers of an amide compound having one or more amide bonds and an organic diisocyanate compound (for example, JP-A-58-140737), diamines having no amide bond and organic diisocyanate compounds. Examples thereof include addition polymers (for example, JP-A-4-97154), and among them, tertiary nitrogen atom-containing polyamides and ammonium salt type tertiary nitrogen atom-containing polyamides are preferable.

Further, the photopolymerizable unsaturated compound preferably used is a ring-opening addition reaction product of polyglycidyl ether of polyhydric alcohol with methacrylic acid and acrylic acid. Pentaerythritol, pentaerythritol, trimethylolpropane, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, an ethylene oxide adduct of phthalic acid, and the like can be mentioned, and among them, trimethylolpropane is preferable.

Examples of photoinitiators include benzophenones, benzoins, acetophenones, benzyls, benzoin alkyl ethers, benzyl alkyl ketals, anthraquinones, thioxanthones and the like. Specifically, benzophenone, chlorobenzophenone, benzoin, acetophenone, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl diisopropyl ketal, anthraquinone, 2-ethyl anthraquinone Examples thereof include 2-methylanthraquinone, 2-allylanthraquinone, 2-chloroanthraquinone, thioxanthone, and 2-chlorothioxanthone.

In the present invention, the cover film is provided to protect the photosensitive resin layer during storage and handling of the original plate and is removed (peeled) before irradiation with actinic rays. As the constituent material of the cover film,
Polyamide; polyvinyl alcohol; copolymers of ethylene and vinyl acetate; amphoteric interpolymers; cellulosic polymers such as hydroxyalkyl cellulose and cellulose acetate; polybutyral; cyclic rubber and the like are suitable. Here, the amphoteric interpolymer is that described in U.S. Pat. No. 4,293,635. Even if any one of the materials is used alone, 2
You may use together 1 or more types. Also, auto-oxidizing compounds such as nitrocellulose and nitroglycerin; non-self-oxidizing polymers such as alkyl cellulose (eg, ethyl cellulose), polyacrylic acid and its alkali metal salts; polyacetals; polyimides; polycarbonates;
Polyesters; polyalkylenes such as polyethylene and polybutylene; polyphenylene ethers; polyethylene oxides; polylactones and combinations thereof can also be used. The thickness of the cover film is preferably 10 to 300 μm, particularly preferably 10 to 200 μm.

Examples of the support used in the present invention include plastic films such as polyester films, metal plates such as iron, stainless steel and aluminum, and metal vapor deposited films. The thickness of the support can be appropriately selected depending on the application. Further, if necessary, in order to improve the adhesion between the support and the photosensitive resin layer, a known adhesive conventionally used for this type of purpose may be provided on the surface.

The method for producing the photosensitive printing original plate of the present invention is not particularly limited, but generally, a photosensitive resin layer is formed on a support by coating, spray coating or the like, or a commercially available photosensitive resin is used. One of the laminates was prepared by peeling the protective film from the printing plate, and separately from this, a base film (cover film) was coated, and a coating layer was formed by spray coating or the like. Two
It is manufactured by laminating two laminated bodies using a heat press machine or the like. Lamination conditions include temperature from room temperature to
150 degreeC, Preferably it is 50-120 degreeC, and pressure is 20.
~ 200 kg weight / cm ² , preferably 50-150 kg
Weight / cm ² is recommended. The photosensitive resin of the present invention can be formed into a sheet having a desired thickness by any known method such as hot pressing, casting, melt extrusion, and solution casting.

In the photosensitive resin original plate of the present invention, a negative film or a positive film having a transparent image portion is closely contacted and superposed on the photosensitive layer, and an actinic ray is irradiated from above to carry out exposure, The part hardens and becomes insoluble.
Actinic rays are usually high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps with a wavelength of 300 to 400 nm,
A light source such as a xenon lamp or a chemical lamp can be used.

After the exposure, a suitable solvent, preferably water, especially neutral water is used as a solvent to dissolve and remove the non-exposed portion, whereby rapid development is carried out in a short time and a printing plate (relief plate) is obtained. can get. As a developing system, it is preferable to use a spray developing device, a brush developing device, or the like.

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by weight".

Example 1 55.0 parts of ε-caprolactam, N, N'-bis (γ-
Aminopropyl) piperazine adipate 40.0 parts,
7.5 parts of 1,3-bisaminomethylcyclohexane adipate and 100 parts of water were put into a reactor, and after performing sufficient nitrogen substitution, the container was sealed and gradually heated. Internal pressure is 1
From the time when the pressure reached 0 kg / cm ² , the water in the reactor was gradually distilled off, returned to normal pressure in 1 hour, and then reacted for 1.0 hour at normal pressure. The maximum polymerization temperature was 220 ° C. The polymer obtained was a transparent pale yellow polyamide having a melting point of 140 ° C. and a specific viscosity of 2.00.

50.0 parts of the obtained polyamide, 5.0 parts of N-ethyltoluenesulfonic acid amide, 0.03 part of 1,4-naphthoquinone, 50.0 parts of methanol and 1 part of water.
0 parts were mixed at 60 ° C. for 2 hours in a heating disintegrator with stirring to completely dissolve the polymer, and then 40.6 parts of an acrylic acid adduct of bisphenol A diglycidyl ester, 2.9 parts of methacrylic acid, Hydroquinone monomethyl ether 0.1 part, ammonium sulfite 0.3 part, oxalic acid 0.
1 part and 1.0 part of benzyl dimethyl ketal were added and dissolved for 30 minutes. Next, the temperature was gradually raised to distill off methanol and water, and the mixture was concentrated until the temperature inside the kettle reached 110 ° C. At this stage, a viscous photosensitive resin having fluidity was obtained.

Next, an adhesive layer of 20 μm was formed on a 250 μm polyethylene terephthalate support to give a total thickness of 270 μm.
m polyester film was prepared.

A polyester urethane adhesive was used for the adhesive layer, and the composition solution for the adhesive layer was prepared as follows. Toyobo Co., Ltd. polyester resin "Byron RV-20"
0 "80 parts by weight of toluene / methyl ethyl ketone = 80
It was dissolved in 1940 parts by weight of a mixed solvent of / 20 (weight ratio) by heating at 80 ° C. After cooling, 20 parts by weight of "Desmodur HL" of isocyanurate-type polyisocyanate manufactured by Sumitomo Bayer Urethane Co., which uses hexamethylene diisocyanate and toluene diisocyanate as isocyanurate-type polyisocyanate as raw materials, and triethylenediamine 0 as a curing catalyst 0.06 part by weight was added and stirred for 10 minutes.

The adhesive layer composition solution thus obtained was applied onto a polyethylene terephthalate film having a thickness of 250 μm so that the film thickness would be 20 μm, and then 120 ° C.
It was dried and cured for 3 minutes to obtain a support having an adhesive layer. The above-mentioned photosensitive resin set was cast on the adhesive layer of this support to form a photosensitive layer.

On the other hand, a polyester film (raw cloth is E5000 manufactured by Toyobo Co., Ltd., thickness: 125 μm, polyvinyl alcohol (Gosenol GH-23 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) / UV absorption emulsion (Shin-Nakamura Chemical Co., Ltd.) Co., Ltd. Newcoat UVA-204W: average molecular weight of about 100,000) / pure water = 4.4 parts / 3.3 parts / 92.3 parts of an aqueous solution dissolved in a bar coater # 8,
Dry at 100 ℃ for 3 minutes and the thickness after drying is 0.5μm
To form a coating layer. The light transmittance of the coating layer at a wavelength of 360 nm was 80%. This light transmittance is U-321
It was measured by a type 0 self-recording spectrophotometer (manufactured by Hitachi, Ltd.). A 125 μm-thick polyester film having this coating layer was laminated on the photosensitive layer with a laminator so that the coating layer side was in contact with the photosensitive layer, and the total thickness was 1075 μm and the photosensitive layer thickness was 68 μm.
A 0 μm sheet-shaped laminate was obtained. This laminated body was solidified into a lower plate at 30 ° C. for storage. After 24 hours 10
After heating at 3 ° C. for 3 minutes and storing for 7 days or more, a photosensitive resin original plate (raw plate) was obtained.

The reproducibility of the fine white pattern was evaluated as follows. A 125 μm polyester film was peeled off, a test negative film was vacuum-bonded, and a sample was exposed for 10 minutes using an A2 size printer (Mitsubishi Chemical Chemical Lamp) manufactured by JEOL Ltd. Then, using tap water as a developing solution and using a brush type washer (140 μmφ nylon brush, JW-A2-PD type manufactured by JEOL Ltd.) for 2 minutes at 25 ° C., a relief image could be obtained. . 70 more
After drying with warm air at 10 ° C. for 10 minutes, a relief plate was obtained by exposing for 3 minutes with a printer for A2 size manufactured by JEOL Ltd. The reproducibility of the blank pattern of the obtained photosensitive printing original plate was evaluated, and the slit width of the negative film was 30 μm.
With respect to the light-shielding pattern, the width of the relief recess was also reproduced to be 30 μm, and the result was to faithfully reproduce the pattern of the negative film. Next, using this relief plate, 30 μm
The printability of the blank pattern was evaluated. For the evaluation, a printing test was performed with a black ink ink (UV Best Cure No5 BF black ink by T & K, Inc.) using a sticker printing machine P-20 manufactured by Sanjo Kikai Seisakusho Co., Ltd. A printed product was obtained.

Comparative Example 1 A photosensitive printing original plate was obtained in the same manner as in Example 1 except that the ultraviolet absorbing emulsion in the coating layer was not added. As a result of evaluating the reproducibility of the blank pattern of the obtained photosensitive printing original plate, the width of the relief concave portion was 2 with respect to the light shielding pattern of the slit width of 30 μm.
It was 0 μm and did not reproduce the pattern of the negative film. Next, using this relief plate, the printability was evaluated in the same manner as in Example 1. In addition, the printed matter was not able to obtain a sharp printed matter due to the ink adhering to the white areas.

Comparative Example 2 Polyester film (original is E5000 manufactured by Toyobo Co., Ltd.)
At a thickness of 125 μm, polyvinyl alcohol (Gosenol GH-23 manufactured by Nippon Synthetic Chemical Industry) / UV absorber having a molecular weight of 323 (RUVA-93 manufactured by Otsuka Chemical) / pure water =
The aqueous solution added at a ratio of 4.7 parts / 0.6 parts / 95 parts was applied with a bar coater # 8 and dried at 100 ° C. for 3 minutes to form a coating layer having a thickness after drying of 0.5 μm. . The light transmittance of the coating layer at a wavelength of 360 nm was 80%. Hereinafter, a photosensitive printing original plate was obtained in the same manner as in Example 1. As a result of evaluating the reproducibility of the fine white pattern of the obtained photosensitive resin laminate, the relief recess width was 20 μm with respect to the light-shielding pattern having a slit width of 30 μm, and the pattern of the negative film was not reproduced. Next, using this relief plate, the printability was evaluated in the same manner as in Example 1. In addition, the printed matter was not able to obtain a sharp printed matter due to the ink adhering to the white areas.

[0030]

As described above, according to the photosensitive printing original plate of the present invention having such a constitution, a fine white pattern is reliefed,
Since it is possible to obtain a printing plate that can be reproduced on a printed matter and can perform high-quality printing, it is a great contribution to the industrial world.

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Claims (2)

[Claims] 1. A photosensitive printing original plate having at least a support, a photosensitive resin layer, a coating layer and a cover film, wherein the coating layer has an average molecular weight of 1, which has absorption in the actinic ray region of the photosensitive resin layer. A photosensitive printing original plate comprising at least 000 light absorbers. 2. The photosensitive printing original plate according to claim 1, wherein the light transmittance of the coating layer is 50% to 99% with respect to light having a wavelength of 360 nm.