JPS60186834A - Photosensitive resin plate material developable with water - Google Patents

Abstract

PURPOSE:To provide a high degree of image reproducibility and excellent printability by providing a cured layer consisting of the compsn. contg. a specific partially saponified polyvinyl acetate, specific vinyl monomer and specific thermosetting resin between a base material and photosensitive resin layer. CONSTITUTION:A compsn. consisting of (A) 100pts.wt. completely or partially saponified polyvinyl acetate having 40-100mol% degree of saponification, (B) 10-300pts.wt. vinyl monomer having an ethylenic unsatd. group in the molecule and (C) 0.1-80pts.wt. thermosetting resin selected from a phenolic resin, melamine resin, epoxy resin and urea resin is coated on a base material having good dimensional stability and is cured to provide an intermediate layer. A photosensitive resin layer contg. partially saponified polyvinyl acetate having 60- 99mol% degree of saponification and photopolymerizable monomer having an ethylenic unsatd. bond is coated on the intermediate layer, by which the photosensitive resin plate material developable with water is obtd.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a partially saponified polyvinyl acetate-based photosensitive resin printing plate having high image reproducibility, excellent printability, and good water developability. It is.

[Description of prior art]

Photosensitive resin plate materials for letterpress, lithographic and intaglio printing, which have a structure in which a photopolymerizable photosensitive resin layer is provided on a metal or glass substrate, have recently been put into practical use. These plate materials are made by attaching a negative or positive original film with a transparent part to a photosensitive resin layer, and then irradiating the photosensitive resin layer with actinic rays to photopolymerize the photosensitive resin layer corresponding to the transparent part of the original film. A relief image is formed on the substrate by eluting the unpolymerized portion with a suitable solvent.

In this way, photosensitive resin compositions that utilize photopolymerization reactions are used for various purposes including printing plates. Among these, partially saponified polyvinyl acetate is used as the base polymer for photosensitive resins that can be developed by eluting unpolymerized portions with neutral water.

It is in practical use that a photopolymerizable monomer is blended with this to impart photosensitivity. Several methods have been proposed for bonding this type of photosensitive resin layer to a dimensionally stable substrate made of metal or plastic.

First, a method has been proposed in which a layer consisting only of a water-soluble polymer is provided as an intermediate layer between a base material and a partially saponified polyvinyl acetate photosensitive resin layer (for example.

Special Publication No. 46-42450). In this method, since the intermediate layer is not three-dimensional at all, the water resistance of the intermediate layer is insufficient, and a problem occurs in which the relief falls off from the base material during overdevelopment.

In order to improve these drawbacks, a system has been proposed in which the intermediate layer uses a composition consisting of partially saponified polyvinyl acetate and .beta.-hydroxyethyl methacrylate (for example, U.S. Pat. No. 3,877,939).

In this case, since the intermediate layer itself undergoes thermal polymerization, a certain degree of water resistance is imparted. However, since the thermal polymerization component is monofunctional methacrylate, the density of the crosslinked structure formed by thermal polymerization is insufficient.

Unfortunately, when an excessive phenomenon occurs, the intermediate layer swells, causing a problem in which the relief peels off from the base material.

As a method to solve this problem of peeling off during over-development of the intermediate layer, the intermediate layer has a two-layer structure, with a layer made of ethylene-vinyl alcohol copolymer having good water resistance provided as the lower layer in contact with the substrate. A method has been proposed in which a layer containing partially saponified polyvinyl acetate and a component 2 such as glyoxazole that crosslinks the partially saponified polyvinyl acetate itself is provided (for example, JP-A-52-128701
). In this case too, if excessive washing is performed, the middle layer
Problems such as peeling between the two lower layers may occur.

[Purpose of the invention]

The object of the present invention is to provide a partially saponified polyvinyl acetate photosensitive resin plate that can be used in a water-based manner and has a high degree of image reproducibility and excellent printability without causing the relief to peel off from the substrate even during excessive washing. The aim is to provide materials. Another object of the present invention is to provide a photosensitive resin layer 4A useful as water-developable letterpress, intaglio, and lithographic printing plates.

[Structure of the invention]

In other words, composition 114 of the present invention is a dimensionally stable photosensitive resin layer comprising partially saponified polyvinyl acetate having a degree of saponification of 60 to 99 molar and a photopolymerizable monomer having an ethylenically unsaturated bond. In a photosensitive resin plate material coated on a base material, the following A,
Thickness 0 obtained by curing a composition containing components B and C
It is a water-developable photosensitive resin layer material provided with an intermediate layer of 5 to 100 microns.

A, 100 parts by weight of completely saponified or partially saponified polyvinyl acetate with a degree of saponification of 40 to 100 molar B9 Vinyl mono-containing an ethylenically unsaturated bond in the molecule = r 10-3
00 Executive Department C, Thermosetting resin selected from the group consisting of phenolic resin, melamine resin, epoxy resin, and urea resin 0.1~
80 parts by weight [Description of preferred embodiments] The photosensitive resin layer used in the present invention has a saponification degree of 60 to 9.
The base polymer is partially saponified polyvinyl acetate having a weight of 9 mol. It is formed from a water-developable photosensitive resin containing a photopolymerizable monomer having an ethylenically unsaturated bond.

The degree of saponification of the partially saponified polyvinyl acetate used as the base polymer must be 60 to 99 mo/I/% and alco. That is, if the degree of saponification is less than 60 molti, the solubility in neutral water will be significantly reduced. Water solubility also decreases when the degree of saponification is 100 mol. Any degree of polymerization can be used, but the average degree of polymerization is 200 to 2.
000 is preferably used. 'There are still partially saponified polyvinyl acetate reacted with ethylene oxide to introduce 0-CH2-CH2- bonds into the side chains, copolymerized small amounts of components such as allyl sulfonic acid of less than 20 moles, and unsaturated polyvinyl acetate. Saturated carboxylic acids, unsaturated aldehydes, N
- Partially saponified polyvinyl acetate, which is obtained by reacting methylol acrylamide, unsaturated epoxy, etc. with a polymer and introducing unsaturated bonds into the side chains or terminals of the polymer, also has a degree of saponification calculated from the number of hydroxyl groups remaining in the polymer. is 60-99
It is included if it falls within the range of morchi. It is also possible to use a mixture of two or more types of partially saponified polyvinyl acetate having different degrees of saponification and polymerization.

Any photopolymerizable monomer having an ethylenically unsaturated group to be blended into the base polymer and one having a certain level of compatibility with the partially saponified polyvinyl acetate of the base polymer can be used. like that.

Examples of photopolymerizable monomers include monofunctional hinyl monomers having a hydroxyl group such as β-hydroxyethyl (meth)acrylate and β-hydroxypropyl (meth)acrylate-1, and carbon-based monomers such as ethylene glycol yafropyrendaricol.
06 to C50 such as ruhinyl monomer, ethylene glycol diglycidyl ether, etc. obtained by adding 2 to 5 hydric polyhydric alcohol and (meth)acrylic acid with 2 to cao
A polyfunctional vinyl monomer having a hydroxyl group obtained by the addition of a polyvalent glycidyl ether and (meth)acrylic acid, an addition of a C5-CSO unsaturated carboxylic acid such as (meth)acrylic acid and glycidyl (meth)acrylate A polyfunctional vinyl monomer having a hydroxyl group obtained by the reaction, a polyfunctional vinyl monomer having a hydroxyl group obtained by the addition reaction of a 02-040 divalent to 5-valent polysaturated carboxylic acid such as oxalic acid and glycidyl (meth)acrylate, Polyfunctional vinyl monomers with hydroxyl groups obtained by the addition reaction of C1 to C4o primary and secondary amines such as diamine and glycidyl (meth)acrylate, (meth)acrylamide, 1-1-methylol (meth)acrylamide, dia These are acrylamides or methacrylamides such as methacrylamide, methine/bis(meth)acrylamide, and a condensate of ethylene glycol and N-methylol(meth)acrylamide.

It is also possible to add a high boiling point alcohol to aid in the compatibility between the partially saponified polyvinyl acetate of the base polymer and the photopolymerizable monomer. Such compounds include ethylene glycol, diethylene glycol, propylene gellicol, ethylene glycol, phthanediol, trimethylolpropane, trimethylolethane, tetramethylolethane, glycerin, diglycerin, and the like.

A photosensitizer may also be added to rapidly photopolymerize the photosensitive resin composition ring.

All known sensitizers can be used as such sensitizers. Examples include benzoins, benzophenones, anthraquinones, benzyls, acetophenones, and diacetyls.

1. To increase the thermal stability of photosensitive resin compositions.

All known thermal polymerization inhibitors can be used.

Examples of such stabilizers include phenols, hydroquinones, catechols, and the like.

It is also possible to add minor components such as surfactants, antifoaming agents, pigments, dyes, ultraviolet absorbers, and antifoaming agents.

'Steel as a dimensionally stable substrate for backing the photosensitive layer consisting of a thickened photopolymer composition.

Metal materials such as aluminum, copper, and zinc, plastic materials such as polyester, polyamide, polyethylene, polyglopylene, and polyvinyl chloride, paper, and woven fabric can be used. These materials are often molded into a flat plate shape and used as a base material, but they can also be molded into other shapes such as a cylindrical shape and used. Metal base materials can be used as is, but they can also be used with surface treatments such as phosphoric acid treatment, chromate treatment, etching treatment, and graining treatment, as well as zinc plating and tin plating.

It is also possible to use plated materials such as chrome plating. Furthermore, in order to enhance the rust-preventing power of the metal substrate, it is also possible to use a metal substrate whose surface is previously coated with a rust-preventing paint such as epoxy, phenol, or acrylic. In order to improve the adhesion between these anti-rust layers and the intermediate layer described below,
It is also possible to provide an adhesive layer between them. As such an adhesive layer, a mixture of completely saponified or partially saponified polyvinyl acetate, an epoxy resin, and a phenol resin can be used. In the case of plastic profiteering,
To improve adhesion between the intermediate layer and the base material.

It is also possible to use materials subjected to surface matting treatment by sandblasting or chemical etching, surface discharge treatment by corona discharge, etc. It is also possible to further provide an adhesive layer between the plastic fly and the intermediate layer to increase the adhesion between the intermediate layer and the profiteer. As such an adhesive layer, a mixture of polyester resin and diisocyanate as main components, chlorinated polypropylene, etc. are used.

In the present invention, the intermediate layer, which plays the role of adhering the photosensitive resin layer and the profit-making layer, consists of completely saponified or partially saponified polyvinyl acetate having a saponification degree of 40 to 100 mol.
It is formed by curing a resin composition consisting of a vinyl monomer having an ethylenically unsaturated group in the molecule of the component and a thermosetting resin selected from the group consisting of a phenol resin, a melamine resin, an epoxy resin, and a urea resin as component C. It is something that Each component forming the intermediate layer will be explained below.

The degree of saponification of the fully saponified or partially saponified polyvinyl acetate used as component A must be in the range of 40 to 100 molar. If the degree of saponification is less than 40 molty, the affinity with the partially saponified polyvinyl acetate having a saponification degree of 60 to 99 molty, which is the base polymer of the photosensitive layer, will be poor, and there will be insufficient space between the intermediate layer and the photosensitive layer. It is not possible to obtain sufficient adhesive strength.

For this reason, the degree of saponification of component A is 40 to 100.
It is necessary that it is within the range of 100%, preferably 6%.
It is in the range of 0 to 99 moles.

Any average jf degree of polymerization of component A can be used, but if the degree of polymerization is too low, the water resistance after photocuring tends to be insufficient, and if the degree of polymerization is too high, it will be difficult to apply for profit. Tend. therefore.

The average degree of polymerization is preferably from 400 to 4,000.

Completely saponified or partially saponified polyacid-resistant vinyl for component A can be prepared by reacting ethylene oxide on the side chain or by copolymerizing a small amount of less than 20 moles of allyl sulfonic acid, as in the case of the composition for the photosensitive layer. It also includes those with unsaturated groups introduced into the side chains or terminals. It is also possible to use a mixture of two or more types of A component. It's a size.

Component A may be the same as the partially saponified polyvinyl acetate used in the photosensitive layer to be laminated, but is not necessarily the same.

Any vinyl monomer having an ethylenically unsaturated bond in the molecule used as component B can be any one having a certain degree of compatibility with component A. Specifically, semi-functional vinyl monomers having a hydroxyl group at C2 to C4O such as β-hydroxyethyl (meth)acrylate-1-, C3 to C50 such as methoxyethylene glycol (meth)acrylate, etc.
Alkoxypolyalkylene glycol (meth)acrylate-1-, ethylene glycol, etc. c2 ~ CSO 2
-Polyfunctional vinyl monomer, ethylene glycol diglycidyl ether, which produces T2+ by the detailed reaction of pentahydric polyhydric alcohol and (meth)acrylic acid.
~A polyfunctional vinyl monomer having a hydroxyl group obtained by addition of a pentavalent polyglycidyl ether and (meth)acrylic acid,
A multifunctional vinyl monomer having a hydroxyl group obtained by the detailed reaction of a 05 to C50 unsaturated carboxylic acid such as (meth)acrylic acid and glycidyl (meth)acrylate, '5'' ac+ to C4a such as xylylene diamine 1st class irc
r, l: A polyfunctional vinyl monomer having a hydroxyl group obtained from secondary diamine and glycidyl (meth)acrylate, and (meth)acrylamide, N-methylol (
meth)acrylamide.

Examples include (meth)acrylamides such as methylenebis(meth)acrylamide and a condensate of ethylene glycol and N-methylolmethacrylamide. It is also possible to use two or more types of B components together.

The vinyl monomer of component B polymerizes with hot active light to form a crosslinked structure, which serves to impart water resistance to the adhesive layer. therefore.

If the amount of component A is 100 parts by weight or less, such effects cannot be achieved. vice versa.

If it exceeds 600 parts by weight, problems such as cracks in the adhesive layer will occur due to excessive crosslinking density.

For the above reasons, the amount of component B used must be in the range of 10 to 600 parts by weight per 100 parts by weight of component A, preferably 60 to 200 parts by weight. It is also possible to use two or more types of B components together.

In order to rapidly carry out thermal polymerization of component B, a known thermal polymerization initiator can be added. Examples of thermal polymerization initiators include peroxides such as benzoyl peroxide, nitrogen compounds such as azobisisobutyronitrile, organometallic compounds such as tetraalkyl chains, and sulfides such as dibenzyl disulfide. Examples include the following.

In order to cure component B by photopolymerization, a known photosensitizer can be added. Such sensitizers include
Benzoins, benzophenones.

Matragynones, benzyls, acetophenones.

Examples include diacetyls.

Examples of thermosetting resins selected from the group consisting of phenol resins, melamine resins, epoxy resins, and urea resins as component C include the following.

Phenol resins obtained by reacting aromatic phenols such as phenol, cresol, xylenol, dinuclear or polynuclear phenolic compounds with formaldehyde can be used. Phenol resins include a resol type obtained by reacting with an excess of formaldehyde and a novolac type obtained by reacting with an excess of phenol, both of which can be used. As the melamine resin, methylolmelamine, which is obtained by reacting melamine with polyaldehyde, and etherified melamine resin, which is further modified with butanol or ethanol, are used. Epoxy resins include those synthesized from polyhydric phenols such as bisphenol A and epichlorohydrin.

Those having a glycidyl group such as ethylene glycol diglycidyl ether can also be used. As the urea resin, methylol urea resin obtained by reacting urea and formaldehyde and alkylated methylol urea resin obtained by reacting this with methanol or the like can be used.

Component C imparts water resistance to the intermediate layer by thermosetting, and at the same time plays the role of developing adhesive strength between the base metal or glass and the intermediate layer.

Therefore, if the amount added is less than 0.1 parts by weight, the effect will not be achieved, and if it is added in excess of 80 parts by weight, the heat curing of the intermediate layer will proceed too much, and the adhesive force between the photosensitive layer and the intermediate layer will be significantly reduced. often decreases.

For these reasons, the use of C component ffJ td t A
It is necessary to range from 01 to 80 parts by weight, more preferably from 1 to 50 parts by weight, based on 100 parts by weight of the component. It is also possible to use two or more types of C components together.

In order to quickly heat-cure component C, it is also possible to use a curing agent that is compatible with each resin. Such curing agents include amines such as hexamethylenetetramine for phenolic resins.

In the case of melamine resins and urea resins, acid catalysts and alkali salts such as p-1-luenesulfonic acid.

Amines and organic acids or their anhydrides are often used in epoxy resins. of course.

Even without adding such a curing agent, sufficient effects can be obtained by selecting an appropriate curing temperature and curing time.

All known heat stabilizers can be used to improve the storage stability of the intermediate layer composition. Furthermore, surfactants, anti-illuminants.

Dyes, pigments, ultraviolet absorbers, antihalation agents, etc. can also be added.

The thickness of the intermediate layer needs to be in the range of 05 to 100 microns. When the thickness is less than 0.5 μm, adhesive strength between the photosensitive layer and the intermediate layer is often not developed.

During excessive washing, the adhesive layer itself often dissolves into the water and breaks off. Because the total thickness of the two-layer phase is determined by the printing machine when the thickness exceeds 100μ.

If the intermediate layer is made too thick, the thickness of the photosensitive layer becomes thin. Therefore, a)) the depth of the relief formed becomes shallow, and the problem that ink is supplied to areas where no relief is formed is likely to occur. For these reasons, it is essential that the thickness of the intermediate layer is between 05 and 100μ,
The preferred size is 1 to 501i.

To form an intermediate layer on a dimensionally stable tip plate, the composition for the intermediate layer is dissolved in a suitable solvent such as an alcohol/water mixed solvent.
'l'g to make a solution, roll coater, gravure coater, curtain flow coater2. After coating the base material to a predetermined thickness using a slit die coater, sprayer, etc., drying and appropriate curing are performed at an appropriate temperature. The thermal polymerization of component B is generally less likely to occur than the thermal curing of component C due to the inhibiting effect of oxygen.

In order to solve this problem, it is effective to add a thermal polymerization initiator to the intermediate layer composition. It is also possible to add a photosensitizer and then expose the entire surface to actinic rays after drying to completely polymerize component B through photopolymerization. When the intermediate layer is insufficiently cured, the intermediate layer lacks water resistance and solvent resistance, resulting in elution of the intermediate layer during excessive washing and swelling of the intermediate layer due to printing ink. vice versa,
If the curing progresses too much, the intermediate layer will become excessively crosslinked.
Adhesion to the photosensitive layer becomes insufficient. Therefore, the curing conditions must be controlled within a range where the water resistance and solvent resistance of the intermediate layer and the adhesion to the photosensitive layer are compatible.

All known methods can be used to form the photosensitive resin layer on the intermediate layer formed on the dimensionally stable base material in this manner. For example, by casting a photosensitive resin solution onto the intermediate layer,
Possible methods are to remove the solvent using a drying device, or to prepare a photosensitive sheet using a dry process and thermally laminate this sheet to the intermediate layer. It is also possible to mold the photosensitive resin composition by discharging it from a die onto the intermediate layer in a state where the photosensitive resin composition does not contain a solvent or contains a small amount of a solvent.

The photosensitive resin layer adhered to the dimensionally stable substrate by the intermediate layer of the present invention can be exposed to light using a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, or a chemical lamp after a positive or negative original film is brought into close contact with the surface of the photosensitive layer. This is carried out using an actinic ray irradiation device such as At this time, photopolymerization occurs only in the portions irradiated with actinic light through the transparent portions of the original film.

After exposure, the plate material is processed using a spray type or brush type developing device using neutral water as a developing solution, by eluting and removing unpolymerized portions into developing water. Development ends when the surface of the intermediate layer is exposed. In this way, a relief is formed which is firmly adhered to the dimensionally stable substrate in the intermediate layer.

The intermediate layer of the present invention exhibits adhesion to the photosensitive layer due to the affinity between the completely saponified or partially saponified polyvinyl acetate of component A and the photosensitive layer whose base polymer is the partially saponified polyvinyl acetate of the upper layer. Furthermore, the synergistic effect of the polymerization of the vinyl monomer as component -B and the thermosetting of the thermosetting resin as component C provides the intermediate layer with sufficient water resistance and solvent resistance. Indeed, strong adhesive force is developed between the substrate and the intermediate layer when the C component is thermally cured. As above.

By combining 6 components A, B, and C, it has superior water resistance compared to conventional intermediate layers.

An intermediate layer having both solvent resistance and adhesive properties is obtained.

The plate material combined with the dimensionally stable base material in this intermediate layer is most effective when used as a convex layer phase.
It is also possible to apply to intaglio printing materials such as lithographic printing plate materials and gravure printing plate materials.

The present invention will be explained in more detail in Examples below.

Example 1 A composition for the intermediate layer was prepared as follows.

100 parts by weight of partially saponified polyvinyl acetate with a degree of saponification of 80 molar and an average degree of polymerization of 1000 was mixed with ethanol/water = 501
It was dissolved in 250 parts by weight of a mixed solvent of 50% (weight ratio) by heating at 80°C. Next, 100 parts by weight of diethylene glycol dimethacrylate as a vinyl monomer and "National Xylene Resin"
15 parts by weight of -1 (Matsushita Electric Works (silk products)) were added and mixed thoroughly with stirring.

The intermediate layer composition thus obtained was applied using a roll coater to a thickness of 5 μm onto a 160 μm thick steel substrate whose two surfaces had been treated with lead phosphate. Then 2
Drying and heat curing were performed by passing through a 40'O audane for 2 minutes.

The following photosensitive resin composition for the photosensitive layer was prepared. First, as partially saponified polyvinyl acetate, the degree of saponification is 8.
100 parts by weight of 5 molti and average polymerization degree of 6oo were dissolved by heating in SO'C in 150 parts by weight of a mixed solvent of ethanol/water = 5o15o (weight ratio). Next, as a photopolymerizable monomer, β-hydroxyethyl methacrylate 80
parts by weight, 20 parts by weight of ethylene glycol diacrylate, and 2 parts by weight of benzoin isopropyl ether as a photosensitizer were added and thoroughly mixed with stirring.

The photosensitive layer composition thus obtained is applied to the substrate.
The thickness of the photosensitive layer after drying is 695 μm on the intermediate layer provided in the second step.
It spread like this. This was placed in an oven at 60°C for 6 hours to remove the solvent. In this way, the total thickness is 560μ
A plate material was prepared.

A test negative film (166 lines, 3 dots, 5-inch, 10-inch halftone dots, diameter 2
00μ, ro 007z independent point 1 width 50□.

(with a 70 μm fine wire portion) was vacuum-adhered and exposed to ultraviolet light from a high-pressure mercury lamp for 1 minute. This exposed plate material was developed at a pressure of 3 kg/IJ+2 using a spray type developing device containing neutral water at a water temperature of 30°C.

When developed for 2 minutes, the unpolymerized portion was eluted into the water.

A relief was obtained on the second substrate. Since the intermediate layer has good water resistance, the diameter of the independent point is 200μ.

Sufficient image reproducibility was obtained without any dropout of fine parts such as thin lines with a width of 50 μm.

A printing test was conducted using the obtained printing plate, but no swelling of the intermediate layer due to the printing ink was observed.

We were able to print 500,000 sheets without any particular problems.

Example 2 A composition for the intermediate layer was prepared as follows.

First, as two-partly saponified polyvinyl acetate, the degree of saponification is 85.
One with a molar ratio and an average degree of polymerization of 2000 was selected.

100 parts by weight of this partially saponified polyvinyl acetate was dissolved by heating at 80'a in 350 parts by weight of a mixed solvent of ethanol/water = 40/60 (weight ratio). Next, tetraethylene glycol diacrylate-1.6 was used as the vinyl monomer.
0 parts by weight and 2 parts by weight of the photosensitizer dimethylbenzyl ketal were added. Furthermore, 10 parts by weight of methyl etherified melamine resin "Super Beckamine" L105-60 (product of Inu Nippon Ink Chemical Co., Ltd.) and 1 part by weight of p-toluenesulfonic acid as a curing accelerator were added and thoroughly stirred. Mixed.

The intermediate layer composition solution thus obtained.

An epoxy anticorrosive paint was applied to a thickness of 2μ and cured on a chromium-plated steel plate substrate (thickness: 250μ) using a curtain flow coater so that the thickness after drying would be 8μ. Next, it was dried and cured by passing it through an oven at 150° for 6 minutes. Under these conditions, the melamine resin has almost completed its thermal curing due to the effect of the curing accelerator, but the vinyl monomer has almost completely thermally polymerized. Since the film lacked water resistance, the vinyl monomer was photopolymerized by exposure to ultraviolet light from a mercury lamp for 2 minutes to obtain a substrate with an intermediate layer.

A composition for a photosensitive layer was prepared as follows. No selection.

100 parts by weight of partially saponified polyvinyl acetate with a degree of saponification of 78 molt and an average degree of polymerization of 700 was mixed with ethanol/water = 5015
It was dissolved in 150 parts by weight of a mixed solvent of 0 (weight ratio) at 70°C. Next, 80 parts by weight of a detailed reaction product of propylene glycol diglycidyl ether and methacrylic acid was added as a photopolymerizable monomer.

Further, 30 parts by weight of trimethylolgloba and 6 parts by weight of dimethylbenzyl ketal as a photosensitizer.

0.1 part of hydroquinone monomethyl ether was added as a thermally stable All, and the mixture was thoroughly stirred and mixed.

The photosensitive resin solution thus obtained was cast onto the chromium-plated steel plate substrate provided with the previously obtained intermediate layer so that the total thickness after drying was 950 μm. Then 6
The solvent was removed by placing it in an oven at 0°C for 5 hours to obtain a resin layer phase.

The same negative film as in Example 1 was vacuum-adhered to the surface of the photosensitive layer of this plate material, and exposed to ultraviolet light from a chemical lamp for 5 minutes. This exposed plate material was developed using a brush type developing device containing neutral water at a temperature of 25°.After developing for 2 minutes, the unexposed areas were eluted into the water and a relief was obtained on the substrate. Since the intermediate layer had good water resistance and sufficient adhesion to the relief, it was confirmed that independent points with a diameter of 200 μm and thin lines with a width of 50 μm were sufficiently reproduced.

In addition, the results of the printing test were also good.

Example 6 A composition for an intermediate layer was prepared as follows. Gunification degree 9
100 parts by weight of partially saponified polyvinyl acetate having a molar ratio of 600 and an average degree of polymerization of 600 were added to 300 parts by weight of a mixed solvent of ethanol/water-filtrate/70 (weight ratio).

The mixture was heated and dissolved at 80°C. Next, 1.40 parts of 2-hydroxyedyl methacrylate, 2 parts by weight of azobisisobutyronitrile as a thermal polymerization initiator, and 40J of Evogishi resin Bapicor 1-826 (product of Shell Chemical Co., Ltd.)
Add No. 13 and stir and mix thoroughly.

The thus obtained intermediate layer solution was applied to a polyester film substrate (P?
After drying, the film was coated with a gravure coater so that the film Jf after drying was 1 (l) μ.

Drying and curing was accomplished by passing the film through an oven at 140'C for 5 minutes.

On this substrate, the same photosensitive layer composition as in Example 1 was cast so that the total thickness after drying (including the substrate) was 700μ, and the mixture was placed in a 60"C oven for 5 hours to dissolve. 11 were removed.

? -7) Radar plate (A was made in the same manner as in Example 1 and subjected to SR' evaluation. As a result, sufficient image reproducibility was obtained without dropping of minute parts. A printing test was conducted using the obtained printing plate, and 500,000 copies could be printed without any problem with tF+.

Example 4 A composition for an intermediate layer was prepared as follows. Saponification degree 7
0 molar ratio, 100 parts by weight of partially polymerized polyvinyl acetate with an average degree of polymerization of 1500 / - / L = / Water = 60
It was dissolved in 250 parts of a mixed solvent of 740 (weight ratio) by heating at 80°C. Next, 1 mol of globylene glycol siglycidyl ether and 2 mols of acrylic acid were used as vinyl monomers.
1,501 moles of (=J reaction product) were added.Furthermore, a butylated urea resin 'Betyamin'''G-1 was added.
800 (Dainippon Ink & Chemicals Co., Ltd. product) 2 iq
, la', R1 (Add and stir/mix thoroughly.

In this way, (1) the obtained intermediate layer composition solution is prepared;

It was coated onto a grained aluminum substrate with a thickness of 350 .mu.m so that the thickness after drying was 30 .mu.m. It was then dried and heat cured by passing it through a 180'a oven for 6 minutes.

The same photosensitive composition as in Example 2 was cast on the thus obtained upper aluminum substrate with an intermediate layer so that the total thickness after drying (including the substrate) was 580 μm.
The solvent was completely removed by placing the sample in a 0.0°C bath for 1 hour.

This layered phase was subjected to the same method as in Example 2 to obtain an Ir value of 11. As a result, it was found that there was strong adhesion between the relief and the substrate down to the smallest details, and the results of the printing test I/c0 also confirmed that there were no problems at all.

Patent R + Applicant Toshi Co., Ltd. Miko Continuation Amendment (Method) % Formula % 1. Indication of the case 1988 Patent Application No. 421 [) [No. 1 2 Name of the invention Water-developable photosensitive resin 5. Relationship with the case of the person making the amendment 1 (101?) Address: 2-2 Muromachi, Nihonbashi, Chuo-ku, Tokyo Name (
15) Toshi Co., Ltd. 5. Number of inventions increased by amendment U Insert "Description".

Claims (1)

[Claims] A photosensitive resin layer containing partially saponified polyvinyl acetate having a degree of saponification of 60 to 99 mol and a photopolymerizable monomer containing an ethylenically unsaturated bond is coated on a legally stable base material. In the photosensitive resin plate material provided, an intermediate layer having a thickness of 05 to 100/7 formed by curing a composition containing the following components A, B, and C between the base material and the photosensitive resin layer. A water-developable photosensitive resin plate material characterized by having the following characteristics: A, fully saponified or partially saponified polyvinyl acetate with a degree of oxidation of 40 to 100 molar 100 parts by weight B Vinylmore 7 having an ethylenically unsaturated group in each molecule
Heavy enemy part C, thermosetting resin selected from the group consisting of phenol resin, melamine resin, epoxy resin, and urea resin 01-8
0 parts by weight