JP2540577B2 - Manufacturing method of photosensitive resin plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a water-developable photosensitive resin plate capable of being 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 areas with water or the like to form a development relief.

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. In addition, many of the polymerizable monomer components added to the photosensitive resin composition have a low molecular weight and a low boiling point, and the monomer is scattered during drying, which causes a problem of environmental pollution.

(Object of the Invention) The present invention provides a process for producing a heat-melt-moldable photosensitive resin plate that does not require a drying step.

(Structure of Invention) That is, the present invention relates to (a) a vinyl ester, a nonionic monomer (A) and //
Alternatively, in the copolymer obtained by copolymerizing the ionic hydrophilic group-containing polymerizable monomer (B), the total amount of the A monomer and the B monomer is 0.1 to 20 mol%, and the remainder is Of the vinyl ester units obtained by saponifying the above-mentioned vinyl ester (however, the amount of the A monomer does not exceed 20 mol% and the amount of the B monomer does not exceed 10 mol%). A water-soluble or water-dispersible polyvinyl alcohol copolymer having a degree of saponification of 50 to 70 mol%, a hot melt flow initiation temperature of 60 to 130 ° C., and having a mercapto group at a terminal, (b) a polymerizable monomer and (C) A method for producing a water-developable photosensitive resin plate, which comprises applying a water-meltable and moldable water-developable photosensitive resin composition containing a photopolymerization initiator onto a substrate by melt molding. .

Component (a) 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.

The copolymerizable nonionic monomer (A) is not particularly limited, but a vinyl monomer having 2 to 12 carbon atoms is preferable. For example, α-olefins such as ethylene, propylene, 1-butene and isobutene, ethyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylates such as butyl (meth) acrylate, (meth) acrylamide, Nonionic monomers such as N, N-dimethylacrylamide, N-vinylpyrrolidone, allyl acetate, allyl alcohol, 2-methyl-3-buten-2-ol, and isopropenyl acetate can be mentioned.

The ionic hydrophilic group-containing polymerizable monomer (B) is a vinyl group and an ionic hydrophilic group such as a carboxyl group or a salt thereof,
A monomer containing an anionic group such as a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, or a cationic group such as an amino group or an ammonium group. Examples of this monomer include (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-acrylamido-2.
-Methyl propane sulfonic acid or a salt thereof, (meth) acryl sulfonic acid or a salt thereof, an ionic hydrophilic group-containing monomer such as (meth) acrylamidopropyltrimethylammonium chloride and the like. A small amount of ionic monomer has a great effect on improving water solubility.

These copolymerizable monomers (A and B) are nonionic monomer (A) alone or ionic monomer (B) alone or nonionic monomer (A) and a small amount of ionic monomer. The copolymer (B) is used in combination with a vinyl ester in the presence of thiol acid, and these copolymerizable monomers are used as the water-soluble polyvinyl alcohol-based copolymer and the copolymer. Of these, the nonionic monomer is preferably a (meth) acrylic acid ester such as methyl (meth) acrylate, N, N-dimethyl, which has a great influence on the compatibility with the polymerizable monomer. Acrylamide, N-vinylpyrrolidone, allyl acetate, allyl alcohol, 2-methyl-3-buten-2-ol, and isopropenyl acetate are (meth) acrylic as the ionic hydrophilic group-containing polymerizable monomer. , Itaconic acid, maleic anhydride, 2-acrylamido-2-methylpropane sulfonic acid, allyl sulfonic acid. Thiolic acid is
It includes an organic thiol acid having a COSH group. Examples thereof include thiol acetic acid, thiol propionic acid, thiol butyric acid, and thiol valeric acid. When the copolymerization is carried out in the presence of thiol acid, a polyvinyl ester-based copolymer having a thioester group at the terminal of the copolymer is obtained, and the polyvinyl alcohol-based copolymer having a mercapto group at the terminal is obtained by saponifying the copolymer. A coalescence is obtained. The amount of thiol acid used is 0.01 to 2 mol%, preferably 0.05 to 1 mol%.
The thiol group increases the sensitivity of the photosensitive composition.

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).
0 to 20 mol%, ionic hydrophilic group-containing monomer (B) 0
.About.10 mol%, and the sum of both monomers must be 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%. 0.1 mol% of copolymerizable monomer
When it is lower than the above range, 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-based copolymer (a) of the present invention is a copolymer of the vinyl ester and the vinyl ester with a radical copolymerizable nonionic monomer (A) or an ionic hydrophilic group-containing monomer (B). And a terpolymer of a vinyl ester, a nonionic monomer (A) capable of radical copolymerization with a vinyl ester, and an ionic hydrophilic group-containing monomer (B) are obtained by saponification by a conventional method. As the performance required for the polyvinyl alcohol-based copolymer (a) of the present invention, the melt viscosity of the obtained composition is appropriate, the compatibility with the polymerizable monomer is good,
Water-solubility and dimensional stability of the resulting photosensitive resin plate (heat retention and creep resistance of the solid retention of the composition) are good, and the like. It is necessary that the temperature at which the polymer starts to melt and flow is from 60 ° C to 130 ° C and the degree of saponification of vinyl ester units is from 50 to 70 mol%.
The following, preferably 700 or less, more preferably 500 or less 10
It is preferably 0 or more. 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 100, it has a poor ability to retain the polymerizable monomer and is difficult to use. The degree of saponification of vinyl ester units depends on the content of radically copolymerizable monomer units, but is 50 mol%.
To 70 mol% is excellent in compatibility with the polymerizable monomer and easy to use, and if it exceeds 70 mol%, the hot melt flow initiation temperature becomes too high, which is unsuitable. If it is less than 50 mol%, the dimensional stability of the resin plate tends to be poor 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 start temperature when the temperature is raised at 6 ° C./min to melt and develop, and the water solubility referred to in the present invention means that a polyvinyl alcohol-based solvent is used at a concentration of 1% by weight at 25 ° C. When the copolymer is dissolved in water, it means that it is completely dissolved or dispersed. 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.

Component (b) As the polymerizable monomer having a polymerizable ethylenic double bond, 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 tetraacrylate, metal methacrylate, ethyl methacrylate, n-propyl methacrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, polyethylene glycol dimethacrylate, Polypropylene glycol dimethacrylate, methoxy polyethylene glycol monomethacrylate, ethoxy polyethylene glycol monomethacrylate, glycerol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate,
Acrylamide, N-methylolacrylamide, N-
Butoxymethyl acrylamide, isobutoxy acrylamide, Nt-butyl acrylamide, methylene bis (acrylamide), ethylene bis (acrylamide), propylene bis (acrylamide), methacrylamide, N-methylol methacrylamide, N-butoxymethyl methacrylamide, itobutoxy Methacrylamide, Nt-butyl methacrylamide, methylene bis (methacrylamide), ethylene bis (methacrylamide), propylene bis (methacrylamide), or mixtures thereof can be mentioned.

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.

Component (c) There are no particular restrictions on the type of photopolymerization initiator (c), but aromatic ketones are 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 include 2,6-dimethoxybenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl ester of 2,4,6-trimethylbenzoyl-phenylphosphinic acid, Examples include sodium salt of 2,4,6-trimethylbenzoyl-phenylphosphinic acid.

Others The blending 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 polymerizable monomer (b) and the polymer (a). 50-30
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. Water may be present in the composition in a range not exceeding 10% by weight, preferably 3-8% by weight. 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 is obtained by extrusion-molding the photopolymerizable resin composition obtained here on 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.

(Effect of the Invention) According to the present invention, a photosensitive resin composition that can be hot 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. Since the composition of the present invention has a mercapto group at the end of the polyvinyl alcohol chain, the sensitivity is improved. 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 Vinyl acetate 2400 parts, methyl acrylate 9 parts, 2-acrylamido 2-methylpropanesulfonic acid sodium salt
1.7 parts of methanol, 250 parts of methanol and 0.55 parts of thiolacetic acid were placed in a reaction vessel, and the inside was thoroughly replaced with nitrogen, and then the external temperature was adjusted to 65
When the internal temperature reached 60 ° C, 20 parts of a methanol solution containing 2 parts of 2,2'-azobisisobutyronitrile was added. Next, 60 parts of a methanol solution containing 10.3 parts of thiolacetic acid, 132 parts of methyl acrylate and 2-acrylamido-2-methylpropanesulfonic acid sodium salt 13
Parts were added uniformly over 5 hours. The polymerization rate after 5 hours was 50.5%. After 5 hours, the container was cooled, and vinyl acetate remaining under reduced pressure was added while adding methanol to obtain a methanol solution of the polymer (concentration: 65%). According to the magnetic resonance analysis (NMR analysis), this copolymer contains 10.2 mol% of methyl acrylate units, 0.4 mol% of 2-acrylamido-2-methylpropanesulfonic acid sodium salt units and 89.4 mol% of vinyl acetate units. confirmed. While stirring 100 parts of this methanol solution at 40 ° C., 4 parts by volume of a 2N sodium hydroxide methanol solution was added and mixed well to carry out saponification. After 30 minutes, the white gel obtained was pulverized, thoroughly washed with methyl acetate / methanol = 7/3 (weight ratio), and then dried to obtain a polyvinyl alcohol copolymer a. The saponification degree of the vinyl ester unit of this copolymer a was found to be 64 mol% by NMR analysis.
The degree of polymerization determined by measuring the intrinsic viscosity in an aqueous solution is 32.
It was 0.

Furthermore, the temperature at which the polyvinyl alcohol-based copolymer a (water content 3% by weight) starts to melt and flow (flow point)
Was 115 ° C.

On the other hand, when the amount of mercapto groups contained in the copolymer a was determined by a method using iodine oxidation, it was 0.85 × 10 ⁻⁴ equivalent / g−
The presence of mercapto groups in the copolymer was confirmed. It is considered that this mercapto group exists at one end of the copolymer molecule due to the polymerization mechanism.

Reference Example 2 Vinyl acetate 1200 parts, allyl acetate 160 parts, methanol 100
Parts and 0.19 parts of thiolacetic acid were charged into a reaction vessel.
Then, 3 parts of 2,2'-azobisisobutyronitrile was added to initiate polymerization. 30 parts of a methanol solution containing 7 parts of thiolacetic acid was added uniformly over 5 hours. The polymerization rate after 5 hours was 45%. The same treatment as in Reference Example 1 was carried out to obtain a methanol solution of the polymer (concentration: 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 b. When this copolymer was analyzed in the same manner as in Reference Example 1, the degree of saponification of vinyl ester units was 65.8 mol%, the degree of polymerization was 400, the flow point was 107 ° C., and the amount of terminal mercapto groups was 0.7 × 10 ⁻⁴ equivalent / g-copolymer. It was a polymer.

Reference Example 3 Vinyl acetate 2400 parts, methanol 250 parts, 2-acrylamido-2-methylpropanesulfonic acid sodium salt 1.
0 parts and 0.56 parts of thiolacetic acid were charged into the reaction vessel. To this system was added 20 parts of a methanol solution containing 1.5 parts of 2,2'-azobisisobutyronitrile, and polymerization was initiated 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 thiolacetic acid was added uniformly 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 of the polymer (concentration: 65%).

As a result of NMR analysis, it was found that 0.35 mol% of 2-acrylamido-2-methylpropanesulfonic acid sodium salt unit was contained.

To 100 parts of a methanol solution of this polymer was added 11 parts of a 2N-sodium hydroxide methanol solution, and the mixture was subjected to post-saponification treatment in the same manner as in Reference Example 1 to obtain a 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 vinyl ester units was 61 mol%, the degree of polymerization was 340, the flow point was 101 ° C., and the amount of terminal mercapto groups was 0.9 × 10 ⁻⁴ equivalent / g It was a polymer.

Example 1 100 parts by weight of polyvinyl alcohol copolymer a (saponification degree of vinyl ester unit: 64 mol%, polymerization degree: 320), ethylene glycol: 15 parts by weight, pure water: 10 parts by weight were put in a kneader,
Mix for 30 minutes at a temperature of 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 Epoxy ester shown in is added to the above mixture, kneaded at 80 ℃ for 30 minutes, the mixture is continuously fed at 80 ℃ using a twin-screw extruder, mixed, defoamed, and antihalation Thickness of agent applied
A 0.5 mm thick film was obtained on a 0.2 mm treated iron plate. Then
The cover film was laminated.

Negative film for testing (150 line%, 5%, 10%, 20% halftone dot, diameter 100) on the photosensitive surface of this photosensitive resin plate material.
μ, 200μ independent points, width 40μ, 60μ thin line part) were vacuum-contacted, and a 3kw high-pressure mercury lamp was irradiated from a distance of 70cm. The irradiation time was 3 seconds for pre-exposure and 15 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. The relief plate thus obtained is heated at 100 ° C for 2
When dried for 3 minutes, 3% halftone dot, diameter 100μ, single point, width 4
No dropout of the 0μ thin line was observed.

Examples 2 to 5 and Comparative Examples 1 to 2 By combining the polyvinyl alcohol copolymers shown in Table 1 with the following polymerization monomers, photosensitive resin plate materials were obtained in the same manner as in Example 1 and the same experiment was 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.

For comparison, those other than the polyvinyl alcohol copolymer of the present invention, that is, ordinary unmodified polyvinyl alcohol k having a saponification degree of 60% and a degree of polymerization of 300, a saponification degree of 70%, a degree of polymerization of
The same experiment was conducted under the conditions shown in Table 1 by using 300 ordinary unmodified polyvinyl alcohol 1 and polyvinyl alcohol m having a saponification degree of 64 mol% and a polymerization degree of 320 excluding the mercapto group from Reference Example 1. . The results are shown in Table 1.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 63-122702 (JP, A) JP 58-72138 (JP, A) JP 60-122937 (JP, A) JP 61- 217036 (JP, A) Japanese Patent Publication 8-10328 (JP, B2) Japanese Patent Publication 8-10330 (JP, B2)

Claims (8)

(57) [Claims] 1. A copolymerization of a vinyl ester, a copolymerizable nonionic monomer (A) and / or an ionic hydrophilic group-containing polymerizable monomer (B) in the presence of thiol acid. In the resulting copolymer, the total amount of A monomer and B monomer is 0.1.
˜20 mol%, the balance being the vinyl ester (provided that the amount of A monomer does not exceed 20 mol%, the amount of B monomer does not exceed 10 mol%). A water-soluble or water-dispersible polyvinyl alcohol copolymer having a degree of saponification of vinyl ester units obtained by saponification of 50 to 70 mol%, a hot melt flow initiation temperature of 60 to 130 ° C., and a terminal mercapto group. Combined, a water-developable photosensitive resin composition containing (b) a polymerizable monomer and (c) a photopolymerization initiator, which is heat-melt moldable, and applied on a substrate by melt molding. Manufacturing method of light-sensitive resin plate. 2. The thiol acid is thiolacetic acid.
The manufacturing method described. 3. The method according to claim 1, wherein the vinyl ester is vinyl acetate. 4. The method according to claim 1, wherein the nonionic monomer (A) is methyl acrylate. 5. The method according to claim 1, wherein the ionic hydrophilic group-containing monomer (B) is sodium 2-acrylamido-2-methylpropanesulfonate. 6. The method according to claim 1, wherein the degree of saponification of the vinyl ester unit of polyvinyl alcohol is 55 to 68 mol%. 7. A compounding ratio of components (a), (b) and (c) is 0.01 to 10 parts by weight with respect to 100 parts by weight of (b).
The method according to claim 1, wherein (a) is 50 to 300 parts by weight. 8. The method according to claim 1, wherein the water-developable photosensitive resin composition has a water content of 10% by weight or less.