JPH0810328B2 - Photosensitive resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a water-developable photosensitive resin composition capable of being hot melt molded.

(Prior Art and Problems Thereof) A water-developable photosensitive resin composition for forming a printing plate, a relief plate or a resist pattern is known. Generally, these photosensitive resin compositions are obtained from a mixture of water-soluble or water-dispersible polyvinyl alcohol, a polymerizable monomer and a photopolymerization initiator.

This composition is used by irradiating light through a negative film to polymerize to form a latent image, and wash away the unexposed portion with water to form a developing film.

This photosensitive resin composition is usually obtained by dissolving polyvinyl alcohol in water, then adding a monomer, coating the substrate, and evaporating the water. This method requires a drying process for evaporation of water, and requires a large amount of equipment, space and time. Further, many of the polymerizable molmer components added to the photosensitive resin composition have a low molecular weight and a low boiling point, so that the monomer is scattered during drying, which causes a problem of environmental pollution.

(Object of the Invention) The present invention provides a hot-melt moldable photosensitive resin composition that does not require a drying step.

(Structure of the Invention) That is, the present invention provides (a) a vinyl ester, a nonionic vinyl monomer (A) capable of radical copolymerization with the vinyl ester, and an ionic hydrophilic group-containing vinyl capable of radical copolymerization with the vinyl ester. A copolymer of monomer (B)
The amount of the monomer is 0.1 to 20 mol%, the amount of the B monomer is 0 to 10 mol%, the rest is the vinyl ester and the total amount of the A monomer and the B monomer is 0.1 to 20 mol%. The saponification degree of the vinyl ester unit obtained by saponifying the copolymer is 50% is 50%.
-70 mol%, a hot melt flow starting temperature of 60 to 130 ° C, and a water-soluble or water-dispersible polyvinyl alcohol-based copolymer, (b) a radically polymerizable polymerizable monomer having an ethylenic double bond, and (C) A water-developable photosensitive resin composition containing a photopolymerization initiator and capable of being melt-molded is provided.

In obtaining the polyvinyl alcohol-based copolymer (a) used in the photosensitive composition of the present invention, the vinyl ester may be vinyl formate, vinyl acetate, vinyl propionate,
Although vinyl benzoate and the like can be used, vinyl acetate is preferably used.

Further, a nonionic vinyl monomer (A) capable of radical copolymerization with a vinyl ester (hereinafter simply referred to as “nonionic monomer”).
Is not particularly limited, but a vinyl-based monomer having 2 to 12 carbon atoms is preferable. For example ethylene, propylene,
Α-olefins such as 1-butene and isobutene, (meth)
(Meth) acrylic acid esters such as methyl acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate, (meth) allylamide, N, N-dimethylacrylamide, N-vinylpyrrolidone, allyl acetate, allyl alcohol, 2 Examples include nonionic monomers such as -methyl-3-buten-2-ol and isopropenyl acetate.

Examples of the ionic hydrophilic group-containing vinyl monomer (B) copolymerizable with the vinyl ester (hereinafter also simply referred to as “ionic hydrophilic group-containing monomer”) include a carboxyl group or a salt thereof, a sulfonic acid group or a A vinyl monomer containing an anionic group such as a salt or a phosphate group or a salt thereof, or an ionic group such as a cationic group such as an amino group or an ammonium group. For example, (meth) acrylic acid or a salt thereof, itaconic acid or a salt thereof, maleic acid or a salt thereof, fumaric acid or a salt thereof, maleic anhydride, 2-acrylamide-
2-methylpropanesulfonic acid or a salt thereof, (meth)
Examples thereof include ionic hydrophilic group-containing monomers such as allylsulfonic acid or a salt thereof and (meth) acrylamidopropyltrimethylammonium chloride. A small amount of ionic monomer has a great effect on improving water solubility.

Further, these radical copolymerizable monomers (A and B) may be the nonionic monomer (A) alone or a combination of the nonionic monomer (A) and a small amount of the ionic monomer (B). Used by copolymerizing with vinyl ester, these copolymerizable monomers greatly affect the water solubility of the polyvinyl alcohol-based copolymer and the compatibility between the polymer and the polymerizable monomer. Of these, preferred nonionic monomers are (meth) acrylic acid esters such as methyl (meth) acrylate, N, N-dimethylacrylamide, N-vinylpyrrolidone, allyl acetate, allyl alcohol, and 2-methyl. -3-Butene-2-ol and isopropenyl acetate are (meth) acrylic acid, itaconic acid, maleic anhydride, and 2-acrylamido as ionic hydrophilic group-containing monomers. 2-methylpropane sulfonic acid, (meth) allylsulfonic acid.

Further, among these, a copolymer obtained by co-polymerizing both the nonionic monomer (A) and the ionic hydrophilic group-containing monomer (B) is most preferably used.

The content of the above-mentioned copolymerizable monomer in the copolymer is determined from the balance of meltability and water solubility, from the nonionic monomer (A).
Is 0.1 to 20 mol%, the ionic hydrophilic group-containing monomer (B) is 0 to 10 mol%, and the total amount of both monomers is 0.1 to 20 mol%. More preferably, the nonionic monomer is 5
It is desirable to use -15 mol% and an ionic hydrophilic group-containing monomer of 0-3 mol%. When the content of the nonionic monomer is less than 0.1 mol%, the meltability is poor, and when it exceeds 20 mol%, the solid retention of the composition is poor and the composition cannot be used.

The polyvinyl alcohol copolymer (a) of the present invention is a vinyl ester or a copolymer of a vinyl ester with a nonionic monomer capable of radical copolymerization, and a vinyl ester or a nonionic monomer capable of radical copolymerization with a vinyl ester. It is obtained by saponifying a terpolymer with a monomer and an ionic hydrophilic group-containing monomer by a conventional method. As the performance required for the polyvinyl alcohol-based copolymer (a) of the present invention, the melt viscosity of the resulting composition is appropriate, the compatibility with the polymerizable monomer is good, and the composition is water-soluble. The dimensional stability of the resulting photosensitive resin plate (heat-creep resistance of the solid retaining property of the composition) is good, etc., but to satisfy these required performances,
The copolymer must have a hot melt flow initiation temperature of 60 ° C. to 130 ° C. and a degree of saponification of vinyl ester units of 50 to 70 mol%. 1000 or less, preferably 700 or less, more preferably 500 or less and 100
The above is desirable. Those having an average degree of polymerization of more than 1000 are unsuitable because the melt viscosity is too high.
If it is less than 0, it is difficult to use because it has poor retention of the polymerizable monomer. Further, the saponification degree of the vinyl ester unit depends on the content of the radically copolymerizable monomer unit, but a content of 50 mol% to 70 mol% has excellent compatibility with the polymerizable monomer, is easy to use, and is more preferable. Is preferably 55 to 68 mol%. If it exceeds 70 mol%, the hot melt flow starting temperature becomes too high, which is unsuitable. If it is less than 50 mol%, the dimensional stability of the resin plate tends to deteriorate, and it cannot be used.

The hot melt flow initiation temperature of the polyvinyl alcohol-based copolymer (a) referred to in the present invention has a water content of 3% by weight.
Polyvinyl alcohol copolymer of 1 mm in diameter, 1 mm in length
With a flow tester with a nozzle of mm, under a load of 50 kg,
It shows the flow starting temperature when the temperature is raised at 6 ° C./min to melt and discharge, and the term “water-soluble” as used in the present invention means that polyvinyl alcohol-based copolymers are used at a concentration of 1% by weight at 25 ° C. It refers to a polymer that shows a state of being completely dissolved or dispersed when it is dissolved in water. The average degree of polymerization ()
Is the intrinsic viscosity [η] of the polyvinyl alcohol-based copolymer measured at 30 ° C. in water and calculated from the viscosity formula.

As the polymerizable monomer having a radical-polymerizable ethylenic double bond of the component (b), various compounds having a polymerizable double bond in the molecule can be used. Specific examples thereof 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, methoxy polyethylene glycol monoacrylate, ethoxy polyethylene glycol monoacrylate, glycerol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, tetramethylolmethane Tetra acrylate, methyl methacrylate, ethyl methacrylate, 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, tetramethylolmethane Tetramethacrylate, acrylamide, N-methylolacrylamide, n-butoxymethylacrylamide, isobutoxyacrylamide, n-t-butylacrylamide, methylenebis (acrylamide), ethylenebis (acrylamide), propylenebis (acrylamide), methacrylic acid. Amide, N-methylolmethacrylamide, n-butoxymethylmethacrylamide, isobutoxymethacrylamide, n-t-butylmethacrylamide, methylenebis (methacrylamide), ethylenebis (methacrylamide), pyropyrenebis (methacrylamide) or mixtures thereof. And so on.

The specific selection of the polymerizable monomer (b) may be performed in consideration of compatibility depending on the type of polymer used. If necessary, in order to assist the compatibility between the two, an appropriate solvent such as water or a high-boiling alcohol (for example, ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, butanediol, trimethylolpropane, tetramethylolethane, glycerol). , Diglycerol) may be added.

There is no particular limitation on the type of the photopolymerization initiator (c), but an aromatic ketone is usually used. A compound having an aromatic ring and a carbonyl group in the molecule is used as the aromatic ketone, and specific examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, 2-methylanthraquinone, 9-fluorenone, benzyl, benzylmethyl ketal, acetophenone, 2,
2'-dimethoxy-2-phenylacetophenone, benzophenone, phenyl-2-thienyl ketone, p-dimethylaminobenzophenone, p, p'-tetramethyldiaminobenzophenone and the like can be mentioned. These compounds may optionally have a substituent such as cyano group, nitro group, methoxy group, sulfonic acid group, phosphinic acid or salts or esters thereof. Examples of such are 2,6-dimethoxybenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-
Examples thereof include diphenylphosphine oxide, ethyl ester of 2,4,6-trimethylbenzoyl-phenylphosphinic acid, and sodium salt of 2,4,6-trimethylbenzoyl-phenylphosphinic acid.

The mixing ratio of the above essential components (a), (b) and (c) is usually 0.01 to 10 parts by weight of the photopolymerization initiator (c) and 100 parts by weight of the polymer (a) with respect to 100 parts by weight of the polymerizable monomer (b). ~ 30
The amount is 0 parts by weight, preferably 0.02 to 5 parts by weight for (c) and 60 to 250 parts by weight for (a).

In addition to the above essential components, if necessary, a polymerization inhibitor (eg 2,6-di-t-butyl-p-cresol, hydroquinone, p-methoxyphenol), dye (eg rose bengal, eosin, methylene blue, malachite green), etc. May be blended.

Since the photosensitive resin composition of the present invention uses the specific polyvinyl alcohol (a), it can be processed by hot melt molding. The hot melt molding is usually performed in an extruder. According to this method, a large-scale drying process is not required, the process is shortened, and the production cost is significantly reduced. A small amount of water may be used as a plasticizer in the hot melt molding, but the amount used is significantly different from the conventional amount used. The compositions of the present invention can also be processed by conventional methods which do not rely on hot melt molding.

A resin plate material can be obtained by extrusion-molding the photopolymerizable resin composition obtained here onto an appropriate support. The support is usually a metal (eg aluminum, zinc,
Iron), plastic (for example, polyethylene terephthalate, polystyrene, polymethylmethacrylate, nylon, cellulose acetate, polyethylene, polypropylene, polycarbonate, polyacrylonitrile, polyvinyl chloride), glass and the like are used. If necessary, the surface of these supports may be pretreated by etching, electrolytic oxidation, corona discharge, or the like, or a thin layer such as an adhesive layer or an antihalation layer may be provided.

In order to form an image using the resin plate material, a method which is conventional per se may be adopted. For example, an image film (negative film or positive film) is brought into close contact with the surface of the resin plate material through an appropriate film or coating layer if necessary, and exposed. After exposure, an image can be formed by dissolving and removing the unexposed portion with an appropriate developing solution, specifically, water.

Various sources of actinic radiation can be used for the exposure, and examples thereof include a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a metal halide lamp, and an ultraviolet fluorescent lamp. Besides, a tungsten lamp, a white fluorescent lamp, a visible light laser, or the like may be used.

(Effects of the Invention) According to the present invention, a photosensitive resin composition that can be melt-molded using a specific modified polyvinyl alcohol is obtained.
By using this composition, a drying step is not required, a large-scale device is not required, and the number of steps is reduced. Also, environmental pollution due to the low boiling point monomer generated in the drying step can be prevented. The photosensitive resin composition of the present invention can be developed with water. The composition of the present invention can be used in various image-forming materials such as resists.

(Example) Hereinafter, the present invention will be described in more detail with reference to Examples.
However, "parts" means "parts by weight".

Reference Example 1 2800 parts of vinyl acetate, 6500 parts of methanol and 10.5 parts of methyl acrylate were placed in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser. The reaction container was placed in a constant temperature oven, the system was replaced with nitrogen while stirring, and then the internal temperature was raised to 60 ° C. Polymerization was initiated by adding 285 parts of a methanol solution containing 5.7 parts of 2,2′-azobisisobutyronitrile to this system. 900 parts of a methanol solution containing 180 parts of methyl acrylate during a polymerization time of 5 hours is adjusted so that the monomer ratio of methyl acrylate and vinyl acetate in the polymerization system becomes constant according to the measured value of the solid content concentration of the polymerization system. Was added dropwise. The solid content concentration in the system when the polymerization was stopped was 17.8%. After heating while introducing methanol vapor to remove unreacted vinyl acetate monomer, a 65% methanol solution of the copolymer was obtained. This copolymer contains 10 mol% methyl acrylate units
It was confirmed by nuclear magnetic resonance (NMR) analysis that it contained 90 mol% of vinyl acetate units. While stirring 100 parts of a methanol solution of this copolymer at 40 ° C., 4.0 parts by weight of a 2N sodium hydroxide methanol solution was added thereto and mixed well to carry out saponification. After 30 minutes, the white gel obtained was crushed with a crusher and methyl acetate / methanol = 7/3 (weight ratio)
After sufficiently washing with, and dried, a polyvinyl alcohol-based copolymer a was obtained. The degree of saponification of the vinyl ester unit of this copolymer was 63.8 mol% by NMR analysis. The degree of polymerization determined by measuring the intrinsic viscosity in an aqueous solution was 350.

Further, the temperature at which the hot melt flow of the polyvinyl alcohol-based copolymer a started was also determined by the flow start temperature in the flow tester (hereinafter referred to as the flow point), and it was 120 ° C.

Reference Example 2 2420 parts of vinyl acetate, 5100 parts of methanol, 9.1 parts of methyl acrylate and 1.7 parts of sodium salt of 2-acrylamido-2-methylpropanesulfonic acid were charged into a reaction vessel. In this system 2,2'-azobisisobutyronitrile 5.0
250 parts of a methanol solution containing 1 part was added and polymerization was initiated at 60 ° C. During the polymerization time of 5 hours, 720 parts of a methanol solution containing 128 parts of methyl acrylate and 13 parts of sodium salt of 2-acrylamido-2-methylpropanesulfonic acid was added dropwise according to the measured solid content of the polymerization system. When the polymerization was stopped, the solid content concentration in the system was 16%. After the unreacted vinyl acetate monomer was removed in the same manner as in Reference Example 1, 65% of the copolymer was removed.
% Methanol solution was obtained. As a result of NMR analysis, it was found that this copolymer contained 10 mol% of methyl acrylate units, 0.4% of 2-acrylamido-2-methylpropanesulfonic acid sodium salt units, and 89.6 mol% of vinyl acetate units.

While stirring 100 parts of a methanol solution of this copolymer at 40 ° C., 4.2 parts by volume of a 2N sodium hydroxide methanol solution was added and well mixed to saponify. The white gel obtained after 30 minutes was pulverized with a pulverizer, thoroughly washed with methyl acetate / methanol = 7/3 (weight ratio), and then dried to obtain a polyvinyl alcohol-based copolymer b. The saponification degree of the vinyl ester unit of this copolymer B was 61.0 mol% by NMR analysis. The degree of polymerization determined by measuring the intrinsic viscosity in an aqueous solution was 320.

Further, the flow point of this copolymer b was 115 ° C.

Reference Example 3 Vinyl acetate 1125 parts, allyl acetate 150 parts, methanol 157
After 0 part was placed in a reaction vessel and the inside was sufficiently replaced with nitrogen, when the internal temperature was heated to 60 ° C., 19.5 parts of 2,2′-azobisisobutyronitrile was added to initiate polymerization. After 5 hours, when the solid content concentration reached 31%, the mixture was cooled to terminate the polymerization.
Post-treatment was carried out in the same manner as in Reference Example 1 to obtain a methanol solution of vinyl acetate-allyl acetate copolymer (concentration of solid content: 65%). NM
As a result of R analysis, the allyl acetate content was 10.2 mol%.

2.0 parts by volume of a methanol solution of 2N-sodium hydroxide was added to 100 parts of this methanol solution, and saponification was carried out in the same manner as in Reference Example 1 to obtain a polyvinyl alcohol copolymer c. This copolymer c has a degree of saponification of vinyl ester units of 6
It had a 6.8 mol%, a flow point of 105 ° C. and a degree of polymerization of 450.

Example 1 100 parts by weight of polyvinyl alcohol copolymer a (saponification degree of vinyl ester unit: 63.8, polymerization degree: 350), ethylene glycol: 15 parts by weight, pure water: 10 parts by weight were put in a kneader and the temperature was adjusted.
Mix for 30 minutes at 80-85 ° C.

0.1 part of p-methoxyphenol, 0.4 part of 2,6-di-t-butyl-p-cresol and 3 parts of 2,2'-dimethoxy-2-phenylacetophenone were dissolved in a polymerizable monomer mixture (I) shown below. : Monomer mixture (I) Trimethylolpropane trimethacrylate 20 parts Epoxy ester 70PA ¹⁾ 20 parts N-vinylpyrrolidone 20 parts 1) Formula commercially available from Kyoeisha Yushi The epoxy ester obtained by adding the obtained solution to the above mixture, kneading at 80 ° C. for 30 minutes, and continuously feeding the mixture at 80 ° C. using a twin-screw extruder,
0.2m thick, mixed, defoamed and coated with antihalation agent
It was discharged to a thickness of 0.5 mm on a treated iron plate of m. Then, the cover film was laminated.

Negative film for test (150 lines 3%, 5%, 10%, 20% halftone dot, diameter 1
00μ, 200μ independent points, width 40μ, 60μ thin line part) was vacuum-contacted and irradiated from a distance of 3cm high pressure mercury lamp 70cm. The irradiation time was 3 seconds for pre-exposure and 25 seconds for main exposure. The exposed plate material was pressed and neutral water of 40 ° C was applied from the spray developing device.
Development was carried out by spraying at 4 kg / cm ² for 1 minute and 30 seconds. The unexposed portion, that is, the uncured portion was eluted in water to obtain a relief. When the relief plate thus obtained was dried at 100 ° C. for 2 minutes, 3% halftone dot, diameter 100 μ, single point,
No loss of 40 μm wide wire was observed.

Examples 2 to 5 and Comparative Examples 1 to 2 By combining the polyvinyl alcohol copolymers shown in Table 1 with the polymerizable monomers shown below, photosensitive resin plate materials were obtained in the same manner as in Example 1 and similar experiments were conducted. I went. Table 1 shows the plate making conditions and the experimental results.

Monomer (II) N-butoxymethylacrylamide 40 parts Kayarad R604 ²⁾ 20 parts 2) Formula sold by Nippon Kayaku Co., Ltd. Having a drug.

Monomer (III) NK Ester A-400 ³⁾ 50 parts 〃 M-40G ⁴⁾ 10 parts 3) Commercially available formula CH ₂ ═CH—COO— (CH ₂ CH ₂ O) ₉ —CO—CH = A compound having CH ₂ .

4) Commercial formula from Shin Nakamura Chemical A compound having the formula:

Monomer (IV) 2-hydroxyethyl methacrylate 60 parts For comparison, other than the polyvinyl alcohol copolymer of the present invention, that is, a normal unmodified polyvinyl alcohol k having a saponification degree of 60% and a polymerization degree of 300 and a normal unmodified state of a saponification degree of 70% and a polymerization degree of 300. The same experiment was performed using polyvinyl alcohol 1 under the conditions shown in Table 1. The results are shown in Table 1.

Claims (6)

[Claims] 1. A vinyl ester and a nonionic vinyl monomer (A) capable of radical copolymerization with the vinyl ester.
And a copolymer of an ionic hydrophilic group-containing vinyl monomer (B) capable of radical copolymerization with the vinyl ester, wherein the amount of the A monomer is 0.1 to 20 mol% and the amount of the B monomer is 0 to 10 Mol%,
The saponification degree of the vinyl ester unit obtained by saponifying a copolymer in which the remainder is the vinyl ester and the total amount of the A monomer and the B monomer is 0.1 to 20 mol% is 50 to 70 mol. %, A water-soluble or water-dispersible polyvinyl alcohol copolymer having a hot melt flow initiation temperature of 60 to 130 ° C., (b) a radically polymerizable polymerizable monomer having an ethylenic double bond, and (c) A melt-developable water-developable photosensitive resin composition containing a photopolymerization initiator. 2. The composition according to claim 1, wherein the vinyl ester is vinyl acetate. 3. The composition according to claim 1, wherein the nonionic vinyl monomer (A) is an alkyl acrylate ester. 4. The composition according to claim 1, wherein the vinyl monomer (B) containing an ionic hydrophilic group is sodium 2-acrylamido-2-methylpropanesulfonate. 5. A method according to claim 1, wherein the degree of saponification of the vinyl ester unit of polyvinyl alcohol is 55 to 68 mol%.
The composition according to the item. 6. A mixing ratio of components (a), (b) and (c) to 0.01 to 10 parts by weight of (c) with respect to 100 parts by weight of (b),
The composition according to claim 1, wherein (a) is 50 to 300 parts by weight.