JPS63314537A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition which has the high compatibility and water soluble property, and the high hardness and rubber elasticity at the time of curing, by incorporating a polyvinyl alcohol type copolymer having a specified water soluble or water dispersible property, a specified polymerizable monomer having at least two free hydroxyl groups and a photopolymerization initiator in the titled composition. CONSTITUTION:The titled composition comprises the polyvinyl alcohol type copolymer having the water soluble or water dispersible property, and the polymerizable monomer expressed by formula I and at least two free hydroxyl groups, and the photopolymerization initiator. Said polyvinyl alcohol type copolymer is obtd. by copolymerizing a vinylester, copolymerizable nonionic monomer A and polymerizable monomer B contg. an ionic hydrophilic group, in the presence of a thionic acid, and is composed of the copolymer obtd. by saponifying the copolymer which contains 0.1-20mol.% total amount of the monomers A and B and the residual amount of vinylester, and has 50-70mol.% saponification degree of a vinylester unit, and 60-130 deg.C temp. at which thermal melt thereof begins to flow, and has mercapto group at its terminal position. Thus, the titled composition which has the high water soluble and compatibility and the high hardness and rubber elasticity at the time of curing, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a water-developable photosensitive resin composition that is heat-melt moldable.

BACKGROUND OF THE INVENTION Water-developable photosensitive resin compositions for forming printing plates, relief plates or resist patterns are known.

Generally, these photosensitive resin compositions are obtained from a mixture of water-soluble or water-dispersible polyvinyl alcohol, a polymerizable monomer, and a photoinitiator.

When irradiated with light, this composition polymerizes to form a latent image, and the areas not exposed to light are washed away with water or the like to form a developed relief before use.

This photosensitive resin composition is usually obtained by dissolving polyvinyl alcohol in water, then adding monomers, and evaporating the sample water applied onto the substrate.

This method requires a drying step to evaporate water,
It requires large-scale equipment, space, and time. Also,
The monomer component added to the photosensitive resin composition has a low molecular weight,
Many have low boiling points, and monomers scatter during drying, causing environmental pollution problems.

Furthermore, if polyvinyl alcohol with a high degree of saponification of vinyl ester units is used, the developed relief will be hard and have drawbacks such as cracking, so it is necessary to reduce the hardness. Low hardness can be imparted by lowering the degree of saponification of vinyl ester units in polyvinyl alcohol, but if the degree of saponification of vinyl ester units is lowered, water solubility becomes poor and water development becomes difficult.

On the other hand, from the viewpoint of printing, low hardness is one of the properties necessary for excellent printing performance, and this cannot be neglected. Furthermore, the elasticity of the relief is also one of the properties necessary for excellent printing performance.

Therefore, it is necessary to have three properties: low hardness, rubber elasticity, and water solubility.

(Objective of the invention) The present invention is a photosensitive resin composition that does not require a drying process, can be molded by hot melting, has high compatibility and water solubility,
Furthermore, the present invention provides a material having appropriate hardness and rubber elasticity upon curing.

(Structure of the Invention) That is, the present invention provides (a) vinyl ester, copolymerizable nonionic monomer (A) and/or
Or a copolymer obtained by copolymerizing the ionic shallow water group-containing polymerizable monomer (B), the total f of A monomer and B monomer
f1h<0.1 to 20 mol%, and the remainder is the vinyl ester (however, the amount of A monomer does not exceed 20 mol%, and the amount of B monomer does not exceed 10 mol%. ) A copolymer obtained by saponifying a copolymer, which has a degree of saponification of vinyl ester units of 50 to 70 mol%, a hot melt flow initiation temperature of 60 to 130°C, and has a mercapto group at the end. or water-dispersible polyvinyl alcohol copolymer, formula (b): % formula % (1) [In formula (1), OR.

Y: OH, OCC=CHt, OC(CPtz)pOH or -0Rs However, R1, R
3 and R4 are the same or different, and each is a hydrogen atom or a methyl group, R7 is an alkylene group having 1 to 5 carbon atoms having a hydroxyl group, R6 is an alkyl group having 1 to 5 carbon atoms having a hydroxyl group, and n is a 4 to 23 alkyl group having 1 to 5 carbon atoms. An integer, m represents 0 or 11, and p represents an integer of 1 to 5. ] and a polymerizable monomer having at least two free hydroxyl groups, and (iii) a photopolymerization initiator.

Component (A) When obtaining the polyvinyl alcohol copolymer (A) used in the photosensitive composition of the present invention, vinyl esters that can be used include vinyl formate, vinyl acetate, vinyl propionate, vinyl benzoate, etc. Vinyl acetate is preferably used.

The copolymerizable nonionic monomer (A) is not particularly limited, but vinyl monomers having 2 to 12 carbon atoms are preferred. For example, ethylene, propylene, 1-butene,
α-olefins such as isobutyne, (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylamide, N,N-dimethylacrylamide, N- Vinylpyrrolidone, allyl acetate, allyl alcohol, 2-
Examples include nonionic monomers such as methyl-3-buten-2-ol and isopropenyl acetate.

The ionic hydrophilic group-containing polymerizable monomer (B) has a vinyl group and an ionic hydrophilic group, such as an anionic group such as a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, A monomer containing a cationic group such as an amino group or an ammonium group. Examples of this monomer include (meth)acrylic acid or its salts, itaconic acid or its salts, maleic acid or its salts, fumaric acid or its salts, maleic anhydride, 2-acrylamidopropanesulfonic acid or its salts. , allylsulfonic acid or its salt, and ionic hydrophilic group-containing monomers such as (meth)acrylamidopropyltrimethylammonium chloride. Ionic monomers have a large effect on improving water solubility even when introduced in small amounts.

These radically polymerizable monomers (AXB) are nonionic monomer (A) alone, ionic monomer (B) alone, or nonionic monomer (A) and a small amount of ionic monomer. (B) may be used by copolymerizing a vinyl ester in the presence of thiol acid, but these copolymerizable monomers will affect the water solubility of the polyvinyl alcohol copolymer (A) and the It greatly affects the compatibility between the polymer and the polymerizable monomer. Among the above, preferred examples of nonionic monomers include (meth)acrylic acid esters such as methyl (meth)acrylate, N,N-dimethylacrylamide, N-vinylpyrrolidone, acetic acid 2,
Allyl alcohol, 2-methyl-3-buten-2=ol, isopropenyl acetate, and ionic hydrophilic group-containing polymerizable monomers include (meth)acrylic acid, itaconic acid, maleic anhydride, and 2-acrylamidopropanesulfonic acid. , (meth)allylsulfonic acid is used. Thiol acids include organic thiol acids having a -CO9H group. Examples include thiol acetic acid, thiol propionic acid, thiol butyric acid, thiol valeric acid, and the like. When copolymerization is carried out in the presence of thiol acid, a polyvinyl ester copolymer having a thioester group at the end of the copolymer is obtained,
This copolymer is saponified to obtain a polyvinyl alcohol polymer having a mercapto group at the end. The amount of thiol acid used is o, o i to 2 mol%, preferably 0.0
It is 5 to 1 mol%.

This terminal mercapto group improves the sensitivity of the photosensitive composition.

Moreover, among these, a copolymer containing both a nonionic monomer and an ionic monomer containing a hydrophilic group is most preferably used.

The content of the above-mentioned copolymerizable monomers in the copolymer is 0 to 2% of the nonionic monomer, depending on the balance between meltability and water solubility.
0 mol%, ionic hydrophilic group-containing monomer from 0 to 10 mol%
And it is necessary to make the total of both vehicle masses 0.1 to 20 mol%. More preferably 5 to 15 nonionic monomers
It is desirable to use 0 to 3 mol% of the ionic hydrophilic group-containing monomer. If the copolymerizable monomer content is lower than 0.1 mol%, the resulting composition will have poor meltability, and the copolymerizable monomer content will be less than 20 mol%.
If it exceeds this, the solid retention properties of the composition will be poor and it cannot be used.

The polyvinyl alcohol copolymer (A) of the present invention is a copolymer of the vinyl ester and a nonionic monomer (A) radically copolymerizable with the vinyl ester or a monomer containing an ionic hydrophilic group (B). coalescence and vinyl esters,
It is obtained by saponifying a terpolymer of a vinyl ester, a radically copolymerizable nonionic monomer (A), and an ionic hydrophilic group-containing monomer (B) by a conventional method. The properties required of the polyvinyl alcohol copolymer (a) of the present invention are: (1) appropriate melt viscosity of the resulting composition, (2) good compatibility with the polymerizable monomer, and (2) water solubility. and (2) the resulting photosensitive resin plate has good dimensional stability (solid retention property and heat resistant creep property of the composition). In order to satisfy these required performances, the hot melt flow initiation temperature of the copolymer must be 60°C to 13°C.
It is necessary that the degree of saponification of vinyl ester units is 50 to 70 mol% at 0°C. Regarding the degree of polymerization, the average degree of polymerization is 1000 or less, preferably 700 or less,
More preferably, it is 500 or less and 100 or more. Those with an average degree of polymerization exceeding 1,000 are unsuitable because their melt viscosity is too high, while those with an average degree of polymerization of less than 100 are difficult to use because of poor retention of polymerizable monomers.

The degree of saponification of the vinyl ester unit varies from 50 mol% to 7% by mole, depending on the content of monomer units capable of radical copolymerization.
If the content is 0 mol%, it has excellent compatibility with polymerizable monomers and is easy to use; if it exceeds 70 mol%, the hot melt flow initiation temperature becomes too high, making it unsuitable; if it is less than 50 mol%, the resin plate cannot be used because the dimensional stability tends to deteriorate.

In addition, the hot melt flow initiation temperature of the polyvinyl alcohol copolymer (a) as referred to in the present invention is when the water content is 3% by weight.
A flow tester equipped with a nozzle with diameter III and length III was used to test 50 kg of polyvinyl alcohol copolymer.
This figure shows the flow start temperature when melting and discharging was performed under a load of 6° C./min. Furthermore, water solubility as used in the present invention refers to a state in which the polyvinyl alcohol copolymer is completely dissolved or dispersed when dissolved in water at a concentration of 1% by weight at 25°C. . Also,
The average degree of polymerization (β) is calculated from the viscosity formula by measuring the intrinsic viscosity [η] of the polyvinyl alcohol copolymer in water at 30°C.

Component (b) The polymerizable monomer used in the present invention is a compound represented by the above formula (1) and has at least two hydroxyl groups. Therefore, even if formula (1) is satisfied, if the number of hydroxyl groups is 1 or 0, it cannot be used in the present invention. Examples of this compound include: CH3Cl12.C1l -COOCH, CIICH, O-(
CH2CH20), C1l 2CHCH20COCH
=C112C113C1i.

j
lCf12・C-C00CII, Cl1-CI+
20- (C1l, C)I20), CH,
ClClCl , 0COC=CH.

(l:83) It may also be a (meth)acrylic acid ester derivative obtained by esterifying the terminal hydroxyl group of the above compound with acrylic acid or methacrylic acid.

Other common monomers may be added to the above-mentioned special monomers.

Specific examples of other monomers having a polymerizable double bond in the molecule include methyl acrylate, ethyl acrylate, n
-propyl acrylate, β-hydroxyethyl acrylate, β-hydroxypropyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, methoxypolyethylene glycol monoacrylate, ethoxypolyethylene glycol monoacrylate,
Glycerol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, methyl acrylate, ethyl acrylate, n-propyl methacrylate, β-hydroxyethyl methacrylate,
β-hydroxypropyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, methoxypolyethylene glycol monomethacrylate, ethoxypolyethylene glycol monomethacrylate, glycerol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethanetetramethacrylate, acrylamide, N-methylol acrylamide, n-butoxymethylacrylamide, isobutoxyacrylamide, n-t-butylacrylamide, methylenebis(acrylamide), ethylenebis(acrylamide), propylenebis(acrylamide), methacrylamide, N-methylolmethacrylamide, n-
Examples include butoxymethylmethacrylamide, isobutoxymethacrylamide, n-t-butylmethacrylamide, methylenebis(methacrylamide), ethylenebis(methacrylamide), propylenebis(methacrylamide), and mixtures thereof.

A specific polymerizable monomer may be selected by considering compatibility depending on the type of polymer used. If necessary, an appropriate solvent,
For example, water or a high-boiling alcohol (eg, ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, butanediol, trimethylolpropane, tetramethylolethane, glycerol, diglycerol) may be blended.

Component (c) There are no particular restrictions on the photopolymerization initiator (c), but aromatic ketones are usually used. As the aromatic ketone, compounds having an aromatic ring and a carnanyl group in the molecule are used, and specific examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, 2-
methylanthraquinone, 9-fluorenone, benzyl,
Examples include benzyl methyl ketal, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, benzophenone, phenyl-2-thenyl ketone, p-tsumethylaminobenzophenone, p,p'-tetramethyldiaminobenzophenone, and the like.

These compounds may optionally have a substituent such as a cyano group, nitro group, methoxy group, sulfonic acid group, phosphinic acid or a salt or ester thereof. Examples of such are 2.6-Simethoxybenzoyl-diphenylphosphine oxide, 2.4.6-Dolimethylbenzoyl-diphenylphosphine oxide, 2.4.6-Dolimethylbenzoylphenylphosphine oxide. Ethyl ester of fluoric acid, sodium salt of 2,4.6-dolimethylbenzoylphenyl fluoric acid, and the like.

The blending ratio of the other essential components (a), (b) and (c) above is usually 0.01 to 10 parts by weight of the photoinitiator (c) to 100 parts by weight of the polymerizable monomer (b), and the polymer (c). b) 5
0 to 300 parts by weight, but preferably (c) is 0.0 parts by weight.
2 to 5 parts by weight, preferably 60 to 250 parts by weight of (a).

In addition to the above essential ingredients, polymerization inhibitors (e.g. 2,6-di-t-butyl-p-cresol, hydroquinone, p-methoxyphenol), dyes (e.g. rose bengal, eonne, methylene blue, malachite green), etc. may be added as necessary. May be blended.

Since the photosensitive resin composition of the present invention uses a specific polyvinyl alcohol copolymer (a), it can be processed by hot melt molding. Hot melt molding is usually carried out using an extruder. According to this method, a large-scale drying process is not required, the process is shortened, and production costs are significantly reduced. Although a small amount of water may be used as a plasticizer during hot melt molding, the amount used is significantly different from the amount used conventionally. Water may be present in the resin composition of the present invention in an amount not exceeding 10% by weight, preferably from 3 to 8% by weight. The compositions of the present invention can also be processed by conventional methods that do not involve hot melt molding.

A resin plate material is obtained by extrusion molding the photopolymerizable resin composition obtained here onto a suitable support. Supports typically include metals (e.g. aluminum, zinc, iron), plastics (e.g. polyethylene terephthalate, polystyrene, polymethyl methacrylate, nylon, cellulose acetate, polyethylene, polypropylene, polycarbonate, polyacrylonitrile, polyvinyl chloride), glass, etc. used. If necessary, the surface of these supports may be subjected to pretreatment such as etching, electrolytic oxidation, corona discharge, etc., and a thin layer such as an adhesive layer or an antihalation layer may be provided.

In order to form an image using the above-mentioned resin plate material, a conventional method may be adopted. For example, an image film (negative or positive film) is brought into close contact with the surface of the resin plate via an appropriate film or coating layer as required, and exposed.

After exposure, an image can be formed by removing the unexposed portions with a suitable developer, specifically water.

For exposure, various active light sources can be used, such as medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, and ultraviolet fluorescent lamps. In addition, tungsten lamps, white fluorescent lamps, visible light lasers, etc. may be used.

(Effects of the Invention) According to the present invention, a photosensitive resin composition that can be hot-melt molded using a specific modified polyvinyl alcohol can be obtained. By using this composition, there is no need for a drying step, no large-scale drying equipment is required, and the number of steps can be reduced.

Furthermore, environmental pollution caused by evaporation of low-boiling monomers generated during the drying process can be prevented. Since the composition of the present invention has a thiol group at the end of the polyvinyl alcohol chain, the sensitivity is greatly improved. The photosensitive resin composition of the present invention can be developed with water.

Further, in the present invention, a special polymerizable monomer is used to impart higher water solubility to the photosensitive resin composition and to impart high rubber elasticity to the cured film obtained by exposure.

The composition of the present invention can be used in various imaging materials, such as resists.

(Example) The present invention will be explained in more detail by giving examples below.

Parts and parts represent parts by weight.

Reference Example 1 2400 parts of vinyl acetate, 9 parts of methyl acrylate, 1.7 parts of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 250 parts of methanol and 0.55 parts of thiol acetic acid were placed in a reaction vessel, and the inside was thoroughly drained. After purging with nitrogen, the outside temperature was raised to 65°C, and when the temperature inside 711 reached 60°C, 20 parts of a methanol solution containing 2 parts of 2,2°-azobisisobutyronitrile was added. Then, 60 parts of a methanol solution containing 10.3 parts of thiol acetic acid, 32 parts of methyl acrylate plus 13 parts of 2-acrylamido-2-methylpropanesulfonic acid sodium salt were added uniformly over a period of 5 hours. Polymerization rate after 5 hours is 50.5%
Met. After 5 hours, the container was cooled and the remaining vinyl acetate was sent out of the system together with methanol under reduced pressure while adding methanol to obtain a methanol solution of the polymer (concentration 65%). This copolymer contained 10.2 mol% of methyl acrylate units and 2-acrylamide-2-
It was confirmed by nuclear magnetic resonance analysis (NMR analysis) that it contained 0.4 mol% of methylpropanesulfonic acid sodium salt units and 89.4 mol% of vinyl acetate units. While stirring 100 parts of this methanol solution at 40°C,
4 parts by volume of a methanol solution of sodium hydroxide was added, mixed well, and saponified. After 30 minutes, the obtained white gel was crushed, thoroughly washed with methyl acetate/methanol-7/3 (weight ratio), and then dried to obtain polyvinyl alcohol copolymer a. The degree of saponification of the vinyl ester units of this copolymer a was analyzed by NMR and found to be 64 mol%. Further, the degree of polymerization determined by measuring the intrinsic viscosity in an aqueous solution was 320. Further, the hot melt flow start temperature (flow point) of this polyvinyl alcohol copolymer a (water content 3% by weight) was 115°C.

On the other hand, when the amount of mercapto groups contained in copolymer a was determined by a method using iodine oxidation, the presence of mercapto groups in the 0.85XIO-' equivalent/9-copolymer was confirmed.

This mercapto group is thought to exist at one end of the copolymer molecule based on the polymerization mechanism.

Reference 4 Example 2 1200 parts of vinyl acetate, 160 parts of allyl acetate, 100 parts of methanol and 0.19 parts of thiol acetic acid were charged into a reaction vessel. Next, 3 parts of 2,2°-azobisisobutyronitrile was added to initiate polymerization. 30 parts of a methanol solution containing 7 parts of thiol acetic acid was added uniformly over 5 hours. The polymerization rate after 5 hours was 45%.

Treated in the same manner as in Reference Example 1, a methanol solution of the polymer (a
65%). As a result of NMR analysis, the allyl acetate content was 10 mol%.

To 100 parts of this methanol solution, 2 parts by volume of a 2N sodium hydroxide methanol solution was added, followed by saponification and post-treatment in the same manner as in Reference Example 1 to obtain a terminal mercapto polyvinyl alcohol copolymer. When this copolymer was analyzed in the same manner as in Reference Example 1, the degree of saponification of the vinyl ester unit was 65.
8 mol %, degree of polymerization 400, flow point 107°C, and terminal mercapto group weight was 0.7XlO-' equivalent/9-copolymer.

Reference Example 3 2400 parts of vinyl acetate, 250 parts of methanol, 1.0 part of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, and 0.56 part of thiol acetic acid were charged into a reaction vessel. To this system was added 20 parts of a methanol solution containing 1.5 parts of 2°2'-azobisisobutyronitrile,
Polymerization started at 60°C. 60 parts of a methanol solution containing 11 parts of 2-acrylamido-2-methylpropanesulfonic acid sodium salt and 10.2 parts of thiol acetic acid was uniformly added over 5 hours. The polymerization rate after 5 hours was 44%. The same treatment as in Reference Example 1 was carried out to obtain a methanol solution (a degree: 65%) of the polymer.

As a result of NMR analysis, it was found that it contained 0.35 mol% of 2-acrylamido-2-methylpropanesulfonic acid sodium salt units. Methanol solution of this polymer 1
00 parts of 2N-thorium hydroxide methanol solution 1.
1 part was added and the saponification post-treatment was carried out in the same manner as in Reference Example 1 to obtain terminal mercapto polyvinyl alcohol copolymer C.

When this copolymer C was analyzed in the same manner as in Reference Example 1, the degree of saponification of the vinyl ester unit was 61 mol%, and the degree of polymerization was 34.
0, flow point 101℃, terminal mercapto group amount 0
．． It was a 9×10” 4 equivalent/9-copolymer.

Reference Example 4 In a 2Q Kolben equipped with a stirrer, a condenser, and a temperature regulator, 370 g of xylene, a bifunctional poxy compound whose main component is the structural formula (commercially available as Evolite 400E from Kyoeisha Yushi Kagaku Kogyo Co., Ltd.) 5269, and methacrylic 86 g of acid, 189 g of pure water, and 1 g of tetrabutylammonium chloride were charged, the temperature was raised while stirring, and the reflux state was maintained for 30 minutes. Thereafter, the temperature was cooled to room temperature.

The analysis results of the photopolymerizable vinyl monomer obtained were determined by NMR.
, IR confirmed that it was the polymerizable monomer (tII). Its acid value is 0.56 and viscosity is 20
It was 0 cps.

Reference Example 5 The same operation as in Reference Example 4 was performed except that xylene 4109, bifunctional engineered poxy compound 5269 mentioned in Reference Example 4, 72 g of acrylic acid, pure water 189 and 1 g of tetrabutylammonium chloride were added to prepare the polymerizable monomer. (
I[) was obtained. The acid value was 0.59 and the viscosity was 170 cps.

Reference Example 6 Xylene 3309, bifunctional poxy compound 5269 listed in Reference Example 4, acrylic acid 1449. The polymerizable monomer (IV) was obtained by carrying out the same operation as in Reference Example 4, except that tetrabutylammonium chloride 19 was charged.

Reference Example 7 In a 2e Kolben equipped with a stirrer, a condenser, and a temperature regulator, a polyethylene glycol monomethacrylate compound whose main component is a polyethylene glycol monomethacrylate compound (Blenmar PE35 from NOF Corporation)
9649 (commercially available as 0), 48 g of glycidol (manufactured by Daicel Chemical Industries, Ltd.) and dimethylbenzylamine 119, and stirred while blowing air.
The temperature was raised to 140°C and maintained for 1 hour. Thereafter, the temperature was cooled to room temperature.

The analysis results of the photopolymerizable vinyl monomer obtained were determined by NMR.
It was confirmed from S[R that it was the polymerizable monomer (■). Its acid value is 0.10 and viscosity is 150
It was cps.

Reference Example 8 Polyethylene glycol monoacrylate compound 936
The polymerizable monomer (Vl) was obtained by carrying out the same operation as in Reference Example 7, except that 148 g of glycidol and 1 g of dimethylbenzylamine were charged. Acid value is 0.12,
The viscosity was 130 cps.

Example 1 100 parts by weight of polyvinyl alcohol copolymer a (degree of saponification of vinyl ester units: 63 mol%, degree of polymerization: 320),
15 parts by weight of ethylene glycol and 10 parts by weight of pure water were placed in a Nigu and mixed for 30 minutes at a temperature of 80 to 85°C.

The polymerizable monomer ( III) Dissolved in 100 parts.

The obtained solution was added to the above mixture, kneaded at 80°C for 30 minutes, and the mixture was continuously fed at 80°C using a twin-screw extruder, defoamed, and coated with an antihalation agent. It was discharged onto a treated iron plate with a thickness of 0.21 to a thickness of 0.5 JIff. A cover film was then laminated.

A test negative film (150 lines, 3%, 5%, 10%, 20% halftone dots,
(diameter 100μ, 200μ, independent point, width 40μ, 60μ thin line part) are vacuum-adhered, and a 3Kw high-pressure mercury lamp is attached to a 70c
It was irradiated from a distance of m.

The irradiation time was 3 seconds for pre-exposure and 15 seconds for main exposure.

This exposed plate material was developed by spraying neutral water at 40° C. from a spray developing device at a pressure of 4 kg/crtt for 1 minute and 20 seconds. When the relief plate thus obtained was dried at 100°C for 2 minutes, no dropout of 3% halftone dots, independent points of 100μ in diameter, and fine lines of 40μ in width was observed. When printed using a Pandercook proofing press (manufactured by Pandercook Co., Ltd.), a paper surface with a density of 120 (measured with a Macbeth reflection densitometer) in the solid areas and good sharpness in the solid areas was obtained.

Incidentally, a photosensitive resin plate having a thickness of 2 mm was produced using a flexo press machine using a spacer having a thickness of 2+U from the discharged product of the twin screw press used to produce this plate material.

This sample was exposed to light for 5 minutes using a 3Kw high pressure mercury lamp. The hardness and elasticity of the pieces were measured by cutting them into 20R squares and stacking them to a thickness of 12aut.
It was a flexible board with a rebound resilience value of 28% (measured by JISK-6301 method at 20°C).

Examples 2 to 7 and Comparative Examples 1 to 3 Photosensitive resin plate materials were obtained in the same manner as in Example 1 using the combinations of polyvinyl alcohol copolymers and polymerizable monomers shown in Table 1, and the same experiments were conducted.

The plate-making conditions and experimental results are shown in Table-1.

For comparison, 80 parts of the following three types of polymerizable monomers and 10 parts of the polyvinyl alcohol copolymer obtained in the above reference example were used.
A similar experiment was conducted in combination with 0 parts. Table 1 shows the results.
Shown below.

*1 Polyvinyl alcohol with a degree of saponification of 60 mol% and a degree of polymerization of 300.

*, polyvinyl alcohol with a degree of saponification of 70 mol% and a degree of polymerization of 300.

*3 Polyvinyl alcohol with a degree of saponification of 64 mol% and a degree of polymerization of 320, excluding mercapto groups from Reference Example 1.

Claims (1)

[Claims] 1. (a) A vinyl ester, a copolymerizable nonionic monomer (A), and/or an ionic hydrophilic group-containing polymerizable monomer (B) in the presence of thiol acid. A copolymer obtained by polymerization, in which the total amount of A monomer and B monomer is 0.1 to 2
0 mol% and the remainder is the vinyl ester (however, the amount of A monomer does not exceed 20 mol% and the amount of B monomer does not exceed 10 mol%). A copolymer obtained by converting vinyl ester units into a copolymer having a saponification degree of 50 to 70 mol% and a hot melt flow initiation temperature of 60 to 13%.
A water-soluble or water-dispersible polyvinyl alcohol copolymer having a mercapto group at the end at 0°C, Formula (B): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In formula (I), X : ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Y: -OH, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or -OR_5 However, R_1, R_3 and R_4 are the same or Differently, each is a hydrogen atom or a methyl group, R_2 is an alkylene group having 1 to 5 carbon atoms having a hydroxyl group, R_5 is an alkyl group having 1 to 5 carbon atoms having a hydroxyl group, n is an integer of 4 to 23, m is 0 or 1 and p represent an integer of 1 to 5. ] A melt-moldable water-developable photosensitive resin composition containing a polymerizable monomer having the following and at least two free hydroxyl groups, and (c) a photopolymerization initiator. 2. The composition according to claim 1, wherein the thiol acid is thiol acetic acid. 3. The composition according to claim 1, wherein the vinyl ester is vinyl acetate. 4. The composition according to claim 1, wherein the nonionic monomer (A) is methyl acrylate. 5. The composition according to claim 1, wherein the ionic hydrophilic group-containing monomer (B) is sodium 2-acrylamido-2-methylpropanesulfonate. 6. The composition according to claim 1, wherein the degree of saponification of the vinyl ester unit of polyvinyl alcohol is 55 to 68 mol%. 7. The blending ratio of ingredients (a), (b), and (c) is (b) 1
00 parts by weight, (c) is 0.01 to 10 parts by weight, (
2. The composition according to claim 1, wherein a) is 50 to 300 parts by weight. 8. The composition according to claim 1, having a water content of 10% by weight or less. 9. A water-developable photosensitive resin plate comprising the water-developable photosensitive resin composition according to any one of claims 1 to 8 provided on a substrate. 10. A printing plate obtained using the resin plate according to claim 9. 11. A method for producing a water-developable photosensitive resin plate, which comprises applying the water-developable photosensitive resin composition according to any one of claims 1 to 8 onto a substrate by melt molding. 12. The method according to claim 11, wherein the water-developable photosensitive resin composition has a water content of 10% by weight or less. 13. A method for producing a printing plate, which comprises exposing the resin plate according to claim 9 to light through a negative film having an image, and then washing the unexposed portions with water.