JPH10171111A - Water-developing photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photosensitive resin compsn. having good deveroping property with water and excellent resistance against flexographic ink, printing durability and storage stability for a long time by adding a surfactant and a specified thermoplastic elastomer having resistance against flexographic ink into a photosensitive resin compsn. SOLUTION: This compsn. contains (A) a sulfonate group-contg. polyurethane which is synthesized from (a) a diol selected from sulfonate group-contg. polyamide diols and sulfonate group-contg. polyester diols, (b) dihydroxyhydrocarbons having 400 to 4000 number average mol.wt., and (c) diisocyanate, (B) a thermoplastic polymer, (C) a surfactant, (D) an ethylene type unsatd. compd. and (E) a photopolymn. initiator. The weight ratio of the component (B) to the component (A) is 10/100 to 300/100, the weight ratio of the component (C) to the sum of components (A) and (B) is 1/100 to 10/100, and the weight ratio of the component (E) to the sum of (A) and (B) is 0.1/100 to 30/100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition for a flexographic printing plate, and more particularly to a water-developable photosensitive resin for a flexographic printing plate having improved flexographic ink resistance after aging at high temperature and high humidity. It relates to a composition.

[0002]

2. Description of the Related Art Heretofore, various base polymers of a photosensitive resin composition used for a photosensitive resin plate material have been known, and particularly, a polyamide polymer is well known. In the past, alcohol-soluble copolymerized polyamides were mainly used as this polyamide-based polymer, but this one has problems in handling workability due to the use of alcohol, and requires an explosion-proof washout device. However, at present, the type that can be washed out with water or an aqueous solution is mainly used.

[0003] Polyamides of this type include:
For example, a polyamide having a sulfonic acid group (Japanese Unexamined Patent Publication No.
No. 68302, JP-A-48-72250, etc.) and polyamides having basic nitrogen or ammonium salt-type nitrogen (JP-A-50-7605, JP-A-5-7605)
0-78401, etc.), and polyamides having ethers (JP-A-48-42049, JP-A-49-49149).
43565). However, printing plates obtained from the above polyamides are inferior in flexographic ink resistance.

Various types of photosensitive resin plates for flexographic printing using a thermoplastic elastomer as a base polymer, which are positioned as a rubber elastic body in place of a rubber plate, are also known. Mainly chlorine-based solvent development type. Since such a chlorine-based solvent developing type has problems such as health hazards and environmental pollution, research has been conducted on photosensitive elastomer compositions that can be developed with water or an aqueous developing solution. Elastomer compositions (see JP-B-59-29849, JP-B-58-33884, etc.) have been proposed. However, these compositions have a problem in ink resistance and the like, and have not been industrialized yet.

On the other hand, a copolymer amide having a polyether segment introduced into a polyamide chain, for example, a polymer having an amino group or a carboxyl group at a terminal, is provided as a material having a good water washout property and giving a soft and tough relief. Copolyamide having a structural unit composed of oxyethylene and an aliphatic dicarboxylic acid or diamine (JP-B-57-18173, JP-B-57-487)
No. 1) or a polyetheresteramide comprising a lactam or nylon salt, a polyoxyalkylene glycol and a dicarboxylic acid (JP-A-58-11737).
And JP-A-60-14232).

Further, in order to further improve water washout properties, polyetheresteramides comprising a sulfonic acid group-containing polyamide, a polyoxyalkylene glycol and a dicarboxylic acid (JP-A-60-8322, JP-A-60-8322) No. 61-162524), and a polyetheresteramide comprising a polyamide having a basic nitrogen, a polyoxyalkylene glycol and a dicarboxylic acid (JP-A-59-221327;
372). However, flexographic printing plates obtained from these polyamide copolymers also have poor flexographic ink resistance.

To solve these problems, Japanese Patent Laid-Open Publication No.
No. 6456 discloses water developability, and flexibility.
As a photosensitive resin composition for flexographic printing having excellent flexographic ink resistance, a photosensitive resin composition containing a novel sulfonic acid group-containing polyurethane as a base polymer has been proposed. However, the plate of the sulfonic acid group-containing polyurethane-containing photosensitive resin composition requires a long time, a high temperature,
It has been found that when stored under humid conditions, the physical properties are reduced, and when printed, the paper is liable to be damaged. Therefore, further improvements in this technology have been desired.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photopolymer having excellent water developability and excellent flexographic ink resistance, printing durability and long-term storage stability using a sulfonic acid group-containing polyurethane as a base polymer. It is to provide a resin composition.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, have found that Japanese Patent Laid-Open No.
The present inventors have found that the object can be achieved by adding a thermoplastic elastomer having flexographic ink resistance and a surfactant to the photosensitive resin composition proposed in Japanese Patent No. 6456, and completed the present invention.

That is, the present invention relates to (A) (a) at least one diol selected from the group consisting of a sulfonic acid group-containing polyamide diol and a sulfonic acid group-containing polyester diol, and (b) a number average molecular weight of 400 to 4,0
(C) a sulfonic acid group-containing polyurethane synthesized from a dihydroxy hydrocarbon and (c) a diisocyanate;
A photosensitive resin composition comprising (B) a thermoplastic polymer, (C) a surfactant, (D) an ethylenically unsaturated compound, and (E) a photopolymerization initiator. The weight ratio of the components is 10/100 to 300/100,
The above (C) with respect to the total amount of the above components (A) and (B)
The weight ratio of the components is 0.1 / 100 to 10/100, the weight ratio of the component (D) to the total amount of the components (A) and (B) is 5/100 to 200/100, A photosensitive resin composition for a printing plate, wherein the weight ratio of the component (E) to the total amount of the component (B) is in the range of 0.1 / 100 to 30/100.

The present inventors have found that the use of the above-described photosensitive resin composition for a printing plate improves the strength and elongation properties after water swelling under high temperature and high humidity, and makes the surfactant water-developable. The present invention has been found to exert a remarkable effect on the improvement, and also exert an effect on the improvement of the compatibility between the sulfonic acid group-containing polyurethane, the thermoplastic polymer, the ethylenically unsaturated compound, and the like, and have completed the present invention. Things.

Hereinafter, the present invention will be described in detail. Component (A) in the composition of the present invention [hereinafter, referred to as component (A)]
As the sulfonic acid group-containing polyamide diol which is one of the raw material components (a), for example, a polyamide dicarboxylic acid synthesized from a polyamide-forming monomer (1) and a dicarboxylic acid or a derivative thereof (2) and a diol component (3) Examples of the above include polyamide diols synthesized from alkylene glycols having 2 to 4 carbon atoms and at least one diol selected from polyoxyalkylene glycols having a number average molecular weight of less than 400. The above (1)
It is necessary that a part or all of the dicarboxylic acid or a derivative thereof used in (2) is a dicarboxylic acid or a derivative thereof containing a sulfonic acid group in a molecule.

Examples of the polyamide-forming monomer (1) include aminocarboxylic acids having 6 or more carbon atoms, or lactams or equimolar salts of dicarboxylic acids having 6 or more carbon atoms with diamines, such as ω-aminocaproic acid, 11 -Aminocarboxylic acids such as aminoundecanoic acid and 12-aminododecanoic acid, caprolactam, laurolactam, hexamethylenediamine-adipate, hexamethylenediamine-sebacate, hexamethylenediamine-isophthalate, undecamethylenediamine- Diamine-dicarboxylates such as adipate, undecamethylenediamine-1,4-cyclohexanedicarboxylate, and undecamethylenediamine-isophthalate can be used alone or in combination.

The sulfonic acid group-containing polyester diol as another raw material component (a) includes, for example, dicarboxylic acid and its derivative (2), and a diol component of alkylene glycol having 2 to 4 carbon atoms and a number average molecular weight. A polyester diol synthesized from at least one diol (3) selected from polyoxyalkylene glycols having a molecular weight of less than 400, wherein a part or all of dicarboxylic acid and its derivative (2) are sulfonic acid groups in the molecule. And a dicarboxylic acid and a derivative thereof.

As the dicarboxylic acid derivative having a sulfonic acid group in the molecule of (2), for example, 2,5- or 3,5-dicarboxybenzenesulfonic acid and its alkali metal salt, 2,5- or 3,3 5-dicarboxymethylbenzenesulfonic acid and its alkali metal salt, 2,
5- or 3,5-dicarbomethoxybenzenesulfonic acid and its alkali metal salt, 2,5- or 3,5
-Dicarbomethoxymethylbenzenesulfonic acid and its alkali metal salt, α-sulfosuccinic acid and its alkali metal salt, α-sulfosuccinic acid dimethyl ester and its alkali metal salt, β-sulfoadipic acid and its alkali metal salt, β-sulfo And adipic acid dimethyl ester and its alkali metal salts.

The number of sulfonic acid groups contained in the dicarboxylic acid or the derivative thereof is preferably 0.05 or more per 1,000 molecular weight of the polymer, more preferably 0.1 to 2 per 1,000 molecular weight of the polymer. . When the number of sulfonic acid groups is less than 0.1 per 1,000 molecular weight of the polymer, the hydrophilicity tends to be insufficient. On the other hand, when the number of sulfonic acid groups exceeds 2 per 1,000 in the molecular weight of the polymer, the synthesis of a polymer having high physical properties tends to be difficult, which is not preferable.

The raw material component (b) of the component (A) in the composition of the present invention has a number average molecular weight of 400 to 4,000.
Are used. Here, the number average molecular weight can be determined by a hydroxyl value determination method using a mixed solvent of acetic anhydride and pyridine. Specific examples of such dihydroxy hydrocarbons include olefins, diolefins, and the like, homopolymerized or copolymerized, or copolymerized with other monomers to form a hydroxyl group at the terminal, or to form a double bond of this compound with hydroxyl. And the like. For example,
Polybutadiene diol, hydrogenated polybutadiene diol, polyisoprene diol, hydrogenated polyisoprene diol and the like. These dihydroxy hydrocarbons may be used alone or in combination of two or more.

Further, in order to favor washout with water or an aqueous solution, it is also possible to use polyethylene glycol in combination with the raw material component (b). However, it is preferable that the content is such that the resistance to flexographic ink is not impaired. Generally, polyethylene glycol can be used in a range of up to 30% by weight of the component (b).

It is also possible to use a chain extender. Examples of the chain extender include diols (such as ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, and hydroquinone diethylol ether). Can be. If the number average molecular weight of the dihydroxy hydrocarbon is less than 400, it is difficult to obtain the required elasticity and flexibility as a printing plate, and if it exceeds 4,000, the number of reaction points tends to be small, and it tends to be difficult to increase the molecular weight. The number average molecular weight of the preferred dihydroxy hydrocarbon ranges from 1,000 to 3,500.

The rubber elasticity and the flexographic ink resistance of the printing plate are achieved by using dihydroxy hydrocarbon as a soft segment. The raw material component (a) and the raw material component (b) of the component (A) in the composition of the present invention are (a) /
(B) It is preferable to carry out the reaction in a ratio of 1/20 to 2/1, and if the ratio is larger than 2/1, the obtained polymer has a high melting point, making molding difficult and / or flexibility. , It is difficult to use as a photosensitive resin plate material for a printing plate, and if it is smaller than 1/20, the obtained polymer has low strength, and it is difficult to use the polymer as a photosensitive resin plate material for a printing plate. Therefore, the preferable ratio of (a) / (b) is 1
/ 10 to 1/1.

The diisocyanate compound as the raw material component (c) of the component (A) in the composition of the present invention may be a free type or a masked one.
Examples of the free diisocyanate compound include, for example, 2,
4- or 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, naphthylene-1,5-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexyl Isocyanate,
Hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane-4,4'-diisocyanate, m- or p
-Tetramethylxylylene diisocyanate and the like.

Examples of the masked diisocyanate compound include, for example, the above-mentioned diisocyanate compounds masked with lactam, phenol, lower alcohol, etc. Among them, diisocyanate masked with caprolactam is particularly preferable. Compounds can be mentioned.
These diisocyanate compounds may be used alone or in combination of two or more.

In the present invention, the component (c) based on the total amount of the hydroxyl groups of the component (a) [polyamide diol containing a sulfonic acid group or the polyester diol containing a sulfonic acid group] and the hydroxyl group of the component [b] (dihydroxy hydrocarbon). The molar ratio of the isocyanate groups of the [diisocyanate compound] (hereinafter referred to as NCO / OH ratio) is 0.60 to
The reaction is preferably performed at a ratio of 1.30. By this reaction, low-viscosity polyamide diols and polyester diols, dihydroxy hydrocarbons and diisocyanates rapidly increase in molecular weight, are highly hydrophilic, and are required as base polymers for photosensitive resin compositions used in flexographic printing plate production. Polyurethane having high mechanical strength, high heat resistance, low permanent tensile strain and low hardness, and having excellent compatibility with ethylenically unsaturated compounds can be obtained. This NCO /
If the OH ratio is less than 0.60, it does not become a high polymer, and it is difficult to obtain a high-strength elastomer, and if it exceeds 1.30, a large amount of diisocyanate crosslinking occurs in the urethane portion,
There is a tendency that it becomes difficult to uniformly knead the desired photosensitive resin composition. Further, from the viewpoints of the mechanical properties of the polyurethane and the uniformity of the photosensitive resin composition, the NC
More preferably, the O / OH ratio is selected in the range of 0.70 to 1.10.

The urethanization reaction is usually performed at 100 to 270 ° C.
At a temperature in the range of If the temperature is less than 100 ° C., the sulfonic acid group-containing polyamide diol and the sulfonic acid group-containing polyester diol may not be easily melted,
In addition, even before melting, before the polymer becomes sufficiently high molecular weight, the melt viscosity becomes high and it becomes difficult to stir. On the other hand, when this temperature exceeds 270 ° C., the urethane bond is easily decomposed, and the polymerization is controlled. In addition to the difficulty, thermal degradation may occur. Furthermore, in order for this reaction to proceed smoothly, it is desirable to remove water in the polyamide diol or polyester diol before reacting the diisocyanate compound.

In this urethane reaction, it is also possible to use a solvent. The solvent may be any one capable of dissolving or dispersing the reaction materials such as polyamide diol and polyester diol, dihydroxy hydrocarbon, and diisocyanate compound, and not reacting with the diisocyanate compound. Pyrrolidone, dimethylsulfoxide, dimethylformamide,
Examples thereof include highly polar solvents such as dimethylacrylamide, aromatic solvents, high-boiling petroleum solvents, and mixed solvents thereof. The solvent is usually used in an amount such that the concentration of the produced polyurethane is 5 to 80% by weight.

The urethanization reaction can be easily carried out even at a temperature of 20 to 150 ° C. by using the above-mentioned solvent, and the control of the reaction becomes easy. Further, a known urethanization catalyst such as an amine catalyst or an organic metal catalyst can be used as needed. The sulfonic acid group-containing polyamide urethane and sulfonic acid group-containing polyester urethane obtained in this manner have a high degree of chain extension of a polyamide diol or polyester diol having a hydroxyl group at a terminal and a dihydroxy hydrocarbon with a diisocyanate compound. It is an elastomer having a molecular weight. When a mixture of polyamide diol and polyester diol is used, polyamide ester urethane is obtained.

In this hydrophilic polyurethane, segments derived from polyamide diol and segments derived from polyester diol have properties as hard segments, and segments derived from dihydroxy hydrocarbons have properties as soft segments. Therefore, the chain is extended with a diisocyanate compound. By doing so, it becomes a soft tough elastomer having excellent elasticity, and a flexographic printing plate obtained from a photosensitive resin composition described below using this as a base polymer has excellent mechanical properties having flexographic ink resistance. Becomes

If the molecular weight of the sulfonic acid group-containing polyurethane of the component (A) in the composition of the present invention is too small, the mechanical properties of the resulting flexographic printing plate become undesirably small. On the other hand, if the molecular weight is too large, the uniform kneading property and the water developability deteriorate, which is not preferable. Generally, a sulfonic acid group-containing polyurethane having a number average molecular weight of 5,000 to 500,000, preferably 10,000 to 200,000 is used.

In order to enhance the stability of the sulfonic acid group-containing polyurethane, various stabilizers such as a heat aging inhibitor and an antioxidant can be used. These stabilizers are added at any stage of the initial stage, middle stage and final stage of polymerization. And may be added after polymerization. Examples of the heat stabilizer include N, N'-hexamethylene-bis (3,5-di-t-butyl-4-hydroxycinnamic acid amide) and 4,4'-bis (2,6-
Various hindered phenols such as di-t-butylphenol) and 2,2′-methylenebis (4-ethyl-6-t-butylphenol), N, N′-bis (β-naphthyl) -p-phenylenediamine, N , N'-diphenyl-p-phenylenediamine, aromatic amines such as poly (2,2,4-trimethyl-1,2-dihydroquinoline), copper salts such as copper chloride and copper iodide, dilauryl thiodipro Examples thereof include a sulfur compound such as a pionate and a phosphorus compound.

These stabilizers act as thermal polymerization inhibitors or retarders in the photosensitive resin composition, and also serve as storage stabilizers. Component (B) in the composition of the present invention
The thermoplastic polymer [hereinafter referred to as “component (B)”] needs to have flexographic ink resistance. For example, styrene-butadiene block copolymer, styrene-isoprene block copolymer, styrene-ethylene / butylene block copolymer, propylene- Ethylene / propylene block copolymer, polyurethane thermoplastic elastomer, polyester thermoplastic elastomer, polyamide thermoplastic elastomer, vinyl chloride thermoplastic elastomer, isoprene rubber, butadiene rubber, styrene / butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, Acrylic rubber, epichlorohydrin rubber and the like can be used, and two or more of these can be used in combination.

If the molecular weight of these thermoplastic polymers is too small, the effect of suppressing deterioration in physical properties is reduced, and if the molecular weight is too large, uniform kneading properties and water developability deteriorate. Therefore, it is preferable to select an appropriate molecular weight. In general, a thermoplastic polymer having a number average molecular weight of 10,000 to 1,000,000, preferably 20,000 to 500,000 can be selected. When the weight ratio of the component (B) is less than 10/100 with respect to the component (A),
The effect of suppressing a decrease in physical properties is reduced, which is not preferable. On the other hand, if it exceeds 300/100, the water developability is undesirably reduced.

The surfactant (C) used in the present invention (hereinafter referred to as “component (C)”) includes an anionic surfactant,
Nonionic surfactants, cationic surfactants, and amphoteric surfactants can be used. For example, higher fatty acid salts, higher alcohol sulfates, higher alkyl ether sulfates, sulfated oils, sulfated fatty acid esters, sulfated olefins, alkylbenzene sulfonates, alkylnaphthalene sulfonates, paraffin sulfonates, α
-Olefin sulfonate, phenyl ether sulfonate, sulfosuccinate, higher alcohol phosphate ester salt, alkylphenol, higher alcohol, polyalkylene glycol, alkylolamide, fatty acid ester, alkylamine ethylene oxide adduct, alkyldiamine ethylene oxide Adducts, alkylamide ethylene oxide adducts, alkylamine oxides, higher alkylamine salts, higher alkylamine / ethylene oxide adducts, imidazoline-type cationic surfactants, alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, ethylene oxide addition types Ammonium salts, amino acid type amphoteric surfactants, betaine type amphoteric surfactants and the like can be used. Among these, nonionic surfactants and anionic surfactants are preferred, and anionic surfactants are particularly preferred, from the viewpoints of compatibility and water developing effect. The amount of these surfactants to be added is appropriately determined depending on the water developability, compatibility, swelling of the ink solvent, and the like.
If the amount is too small, the water developability will be poor, and if it is too large, the performance will be poor in terms of compatibility and solvent swellability. Generally, 0.1 to the total amount of the components (A) and (B).
/ 100 to 10/100, preferably 0.2 / 100 to
The component (C) is added at a ratio of 5/100.

(D) used in the photosensitive resin composition of the present invention
As the ethylenically unsaturated compound (hereinafter, referred to as component (D)), various known ethylenically unsaturated monomers and ethylenically unsaturated prepolymers can be used. Specific examples of the ethylenically unsaturated monomers include unsaturated carboxylic acids such as acrylic acid and methacrylic acid and esters thereof, for example, alkyl-, cycloalkyl-, halogenated alkyl-, alkoxyalkyl-, hydroxyalkyl-,
Aminoalkyl-, tetrahydrofurfuryl-, allyl-, glycidyl-, benzyl-, phenoxy-acrylate or methacrylate, alkylene glycol diacrylate or methacrylate, trimethylolpropane triacrylate or methacrylate, glycerin triacrylate or methacrylate, pentaerythritol tetraacrylate or Methacrylates and the like, acrylamide, methacrylamide and derivatives thereof, for example, N-substituted or N, N
'-Substituted acrylamide or methacrylamide, diacetone acrylamide or methacrylamide, N, N
'-Alkylenebisacrylamide or methacrylamide and the like, allyl compounds such as allyl alcohol, allyl isocyanate and the like, maleic acid, fumaric acid and esters thereof such as alkyl, alkyl halide, alkoxyalkyl mono- and diesters and the like, and others Vinyl compounds such as styrene, vinyl toluene,
Examples thereof include divinylbenzene, N-vinylcarbazole, and N-vinylpyrrolidone.

On the other hand, as the ethylenically unsaturated prepolymer, an ethylenically unsaturated compound having a reactive group such as a carboxyl group, a hydroxyl group or an isocyanate group on a polyester, polyurethane, polyether, epoxy resin, acrylic resin or the like is used. What introduces an ethylenically unsaturated group is used. In the photosensitive resin composition of the present invention, the ethylenically unsaturated compound of the component (D) may be used alone or in combination of two or more.

The weight ratio of the component (D) to the total amount of the components (A) and (B) is from 5/100 to 200/1.
00 is selected in the range. If the weight ratio is less than 5/100, curing by actinic light may be insufficient.
If it exceeds 00/100, the resulting composition tends to have insufficient shape retention at room temperature, which is not preferable. As the photopolymerization initiator (hereinafter referred to as "component (E)") in the photosensitive resin composition of the present invention, various known compounds can be used, and various organic carbonyl compounds, particularly aromatic carbonyl compounds, are preferred. is there.

Specific examples of such compounds include compounds represented by the following general formulas (1) to (3) or derivatives thereof. (1) Benzoin represented by the following general formula (1) and derivatives thereof, specifically, benzoin ethyl ether, benzoin-n-propyl ether, benzoin isopropyl ether, benzoin isobutyl ether and the like.

[0037]

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(Wherein R ¹ is a hydrogen atom or an alkyl group such as methyl, ethyl, isopropyl and isobutyl). (2) Phenyl ketones represented by the following general formula:
2,2 dimethoxy-2-phenylacetophenone and the like.

[0039]

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(Wherein R ² , R ³ , R ⁴ and R ⁵ are each a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a phenyl group, an alkylthio group, a morpholino group, etc. (3) Benzophenone represented by the following general formula and derivatives thereof, such as methyl-O-benzoylbenzoate.

[0041]

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(Wherein R ⁶ and R ⁷ are a hydrogen atom, an alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an alkylthio group, an amino group, etc., which may be the same or These photopolymerization initiators may be used alone or in combination of two or more.

When the weight ratio of the component (E) to the total amount of the components (A) and (B) is less than 0.1 / 100, the photocurability of the entire composition becomes insufficient, and / 1
If it exceeds 00, light transmission is hindered and photo-curing of only the surface is unpreferable, so it is selected in this range. Also,
In order to prevent a dark reaction during storage, a known polymerization inhibitor or polymerization retarder can be added to the photosensitive resin composition of the present invention as desired.

The photosensitive resin composition of the present invention may contain, if necessary, organic and inorganic fillers, dyes, pigments, etc. in addition to the above-mentioned components. In order to improve the flexibility of the printing plate and the printing plate, a suitable plasticizer which is uniformly compatible with the components (A), (B), (C), (D) and (E) and has a plasticizing effect is obtained. An agent can also be compounded.

The photosensitive resin plate material of the present invention usually has a thickness of 0.1 mm.
It has a photosensitive resin layer of 1 to 10 mm. In order to prepare this photosensitive resin plate material, for example, after dissolving each component constituting the photosensitive resin composition in water or an organic solvent and sufficiently mixing to obtain a homogeneous solution, A method in which a photosensitive layer having a thickness of 0.1 to 10 mm is formed on the support by uniformly flowing the solution on the support to a constant thickness, and removing the solvent by evaporation. A method of forming a photosensitive layer by heating and pressurizing a solvent obtained by distilling off the solvent of the product by press molding or the like on a support can also be used. Further, a photosensitive layer is formed by press-molding a mixture of the components constituting the photosensitive resin composition in a kneader, a Banbury mixer or the like on a support, or by other methods such as cast molding and extrusion molding. A method of forming a layer or the like can also be used.

Further, the photosensitive layer formed into a sheet can be directly formed on a support and adhered simultaneously with the formation.
The photosensitive layer formed into a sheet may be adhered to a support using an adhesive, and a sheet having only the photosensitive layer may be used as a plate material. When such a support is not used, for example, a printing plate can be prepared by the method disclosed in Japanese Patent Publication No. 45-23615. When preparing a plate material having a photosensitive layer provided on a support, it is also advantageous to provide an antihalation layer between the support and the photosensitive layer in addition to the adhesive layer. As such a support, for example, a plastic sheet such as polyethylene terephthalate, polypropylene, cellulose triacetate, or polycarbonate, a synthetic rubber sheet, a metal sheet, a synthetic paper, or a composite material thereof can be used.

The shape of the photosensitive resin plate material is not particularly limited, and it may be formed into a sheet shape or a sleeve shape, or may be used, or a photosensitive layer may be formed on the surface of a sleeve-shaped support. . In this case, the photosensitive layer has a thickness of 0.1 to
It is formed in a range of 10.0 mm. As an active light source used for exposure, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, a xenon lamp, or the like is used.

As the developer for the uncured resin, for example, water, an aqueous alkali solution, an aqueous surfactant solution or the like is used.

[0049]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples. The water developability measuring method, the photosensitive resin relief printing plate manufacturing method, the swelling ratio measuring method, and the tensile strength and elongation measuring method used in this example are as follows. Water developability measurement method: The photosensitive resin composition obtained in each example was sandwiched between a 100 μm-thick polyester film and a 100 μm-thick polyester film to which an adhesive was previously applied, and was 2.0 mm thick Was hot-pressed using the spacer. In this way, a thickness of 10
A photosensitive resin plate material having a 2.0 mm photosensitive resin layer on a 0 μm polyester film is prepared.

Next, a commercially available flat developing machine (JOW A3-) equipped with a 200 μm diameter nylon brush
P-type: manufactured by JEOL Ltd.)
-6 (washout agent for APR: manufactured by Asahi Kasei) is dissolved at 2% by weight, and the time required to develop a 1 mm thick film with a developing solution at 40 ° C .: T (minute) is determined. Here, it is assumed that the water development speed = T (min / mm).

A method for producing a photosensitive resin relief printing plate: A negative film composed of characters and patterns is adhered to the photosensitive resin plate material obtained by the water developability measurement method, and a wavelength of 370 nm is first applied from the polyester film side with an ultraviolet fluorescent lamp. Exposure at 1000
mj / cm ² , then exposure from the negative film side 6000
After irradiation with mj / cm ² , the negative film is removed. Next, after developing for T minutes in the same apparatus and under the same conditions as in the above-described water developability measuring method, the unexposed portions are removed, followed by drying and post-exposure to prepare a photosensitive resin relief plate.

Swelling ratio measurement method: The photosensitive resin composition obtained in each of the examples was sandwiched between two polyester films having a thickness of 100 μm, and hot pressed using a spacer for adjusting the thickness. A photosensitive resin plate material having a thickness of 1 mm sandwiched between polyester films having a thickness of 100 μm is prepared. Next, the resin plate material was exposed to light with an exposure amount of 3 using an ultraviolet fluorescent lamp.
After irradiating 600 mj / cm ² , the polyester film is peeled off from both sides of the plate to obtain a photosensitive resin cured plate for performance measurement.

The obtained hardened plate material is 50 mm long × 10 m wide.
A sample of m is prepared and used as a test piece for measuring a swelling ratio. The swelling ratio of the hardened plate material in water and isopropyl alcohol (IPA) is measured by the following method. The weight W _w1 of the test piece before _immersion is measured. Next, the test piece is immersed in water at 20 ° C. for 24 hours, taken out, and after removing water drops on the surface, the weight W _{w2 of the} test piece is measured. The water swelling ratio = X _W (%) is obtained by calculation as follows.

[0054] Using IPA instead of water by the above method, IPA swelling ratio = X _I (%) is obtained.

Tensile strength and elongation measuring method: The photosensitive resin cured printing plate obtained by the above-mentioned swelling ratio measuring method was used and the measuring portion was 30 mm in length.
X A 3 mm wide sample is prepared and used as a test piece for measuring tensile strength and elongation. Tensile strength and elongation are measured using a tensile tester (AUTOGRAP
HAG-A type: manufactured by Shimadzu Corporation) at 20 ° C. and 500 mm / min. Tensile breaking strength = TS _B (kg
/ Cm ² ) and tensile elongation at break = E _B (%).

A sample of 30 mm long × 3 mm wide is used for 50 samples.
It is stored for 7 days in an atmosphere of 80 ° C. and 80% humidity, taken out, and used as a test piece for measuring tensile strength and elongation. The tensile strength and elongation were measured using the same apparatus and conditions as described above, and the tensile breaking strength after humid aging =
TS _W (kg / cm ² ) and tensile elongation at break = E _W (%) are obtained.

[0057]

Example 1 First, a method for producing a sulfonic acid group-containing polyurethane which is one of the main components of the photosensitive resin composition will be described.
Next, a method for producing the photosensitive resin composition will be described. (1) Synthesis of polyester diol containing sulfonic acid group 1,0 equipped with a stirrer, a nitrogen inlet and an outlet pipe.
In a 00 ml separable flask, 296 g of sodium sulfoisophthalate dimethyl ester, 310 g of ethylene glycol, N, N'-hexamethylenebis (3,5-
Di-t-butyl-4-hydrocinnamamide) [IRGA
NOX1098: Ciba-Geigy], 0.43 g and zinc acetate 0.43 g, and 200
After reacting at 5 ° C. for 5 hours, unreacted ethylene glycol was distilled off under reduced pressure to obtain a pale yellow sulfonic acid group-containing polyester diol having a hydroxyl group at a terminal. Its number average molecular weight was 492 as measured by hydroxyl value.

(2) Synthesis of Sulfonic Acid Group-Containing Polyurethane 3,0 equipped with a stirrer, a nitrogen inlet and an outlet pipe.
In a 00 ml separable flask, 39.9 g of the sulfonic acid group-containing polyester diol obtained in the above step (1), 377.7 g of polyisoprene diol having a number average molecular weight of 2,439 and hydroxyl groups at both terminals [manufactured by Idemitsu Petrochemical], octyl After charging 1.4 g of diphenylamine hydride [NOCRACAD: manufactured by Ouchi Shinko Chemical Co., Ltd.], 1000 g of dimethylacetamide and 1000 g of 2-chlorotoluene were added thereto to prepare 1
A homogeneous solution was obtained at 10 ° C.

Next, 0.11 g of dibutyltin dilaurate
And 0.44 g of stannaus octoate, and 43.1 g of xylylene diisocyanate was added dropwise while adding 13.1 g of xylylene diisocyanate.
After reacting at 10 ° C. for 3 hours, dimethylacetamide and 2-chlorotoluene were distilled off under reduced pressure to obtain a uniform and transparent sulfonic acid group-containing polyurethane. (3) Preparation of photosensitive resin composition The sulfonic acid group-containing polyurethane 4 obtained in the above step (2)
9.5 g of styrene-isoprene block copolymer [Califlix TR1107: Shell Chemical Co., Ltd.] in a nitrogen atmosphere at 150 ° C. using a pressure kneader at 20 g.
｛(B) component / (A) component (weight ratio) = 40.4 / 10
0%, sodium laurylbenzenesulfonate 2g
｛(C) component / (A) + (B) component (weight ratio) = 2.9
/ 100}, polybutadiene diacrylate [BAC-
45: Osaka Organic Chemicals] 5 g, aliphatic diacrylate [C-2000: Sartomer] 1 g, dioctyl fumarate 2 g or more (component (D) / component (A) + component (B) (weight ratio) = 11.5) / 100}, 2g of 2,2-dimethoxyphenylacetophenone {(E) component / (A) + (B)
Component (weight ratio) = 2.9 / 100 °, 10 g of maleated modified polybutadiene [ME-1000-80: manufactured by Nippon Petrochemical], N-ethyltoluenesulfonamide 7.5
g, 0.1 g of 2,2-di-t-butyl-p-cresol
And a uniform transparent photosensitive resin composition was obtained.

Next, using the obtained photosensitive resin composition,
A photosensitive resin relief printing plate with good plate reproducibility was created by the photosensitive resin relief printing plate manufacturing method, and when printed on paper using a water-based ink with a flexo rotary press, sharp prints with no swelling due to the ink and little image thickening were obtained. was gotten. The main component of this ink solvent is water: isopropyl alcohol = 8:
2 mixed components. In addition, this photosensitive resin letterpress is 25 ° C.
-After storage at 80% for 30 days, there was no chipping of the photosensitive resin relief image portion even after printing.

Similarly, the water development rate was measured by the water developability measuring method, the water swelling rate and the IPA swelling rate were measured by the swelling rate measuring method, the tensile elongation was measured by the tensile elongation measuring method, and the tensile elongation after humid aging was measured. Strong elongation was obtained and the results are shown in Table 1.

[0062]

Comparative Example 1 In step (3) of Example 1, a composition excluding the styrene / isoprene block copolymer and sodium laurylbenzenesulfonate was kneaded to similarly obtain a photosensitive resin composition. Next, using the obtained photosensitive resin composition, a photosensitive resin relief printing plate having good plate reproducibility was prepared by a photosensitive resin relief printing plate manufacturing method, and printed using a flexo rotary press in the same manner as in Example 1 to obtain an ink. A sharp print with no swelling and little image thickening was obtained. When this photosensitive resin letterpress was stored at 25 ° C. and 80% for 30 days and printed, the printed matter had good ink transfer and ink transferability. However, when 10,000 copies were printed, the photosensitive resin letterpress image area was printed. Could not be printed due to missing part.

Similarly, the water development rate was measured by a water developability measuring method, the water swelling rate and IPA swelling rate were measured by a swelling rate measuring method, the tensile elongation was measured by a tensile elongation measuring method, and the tensile elongation after humid aging was measured. Strong elongation was obtained and the results are shown in Table 1. As can be seen from this, it was presumed that the mechanical properties after the lapse of time under the humid condition were small, and were therefore lacking.

[0064]

Comparative Example 2 A composition excluding sodium laurylbenzenesulfonate in step (3) of Example 1 was kneaded to similarly obtain a photosensitive resin composition. Next, using the obtained photosensitive resin composition, a photosensitive resin relief printing plate was prepared by a photosensitive resin relief printing plate manufacturing method.
It took twice. Further, chipping was observed around the highlight portion, and a plate having good plate reproducibility was not obtained.

Similarly, the water development rate was measured by the water developability measuring method, the water swelling ratio and the IPA swelling ratio were measured by the swelling ratio measuring method, the tensile elongation was measured by the tensile elongation measuring method, and the tensile elongation after humid aging was measured. Strong elongation was obtained and the results are shown in Table 1.

[0066]

Example 2 In step (3) of Example 1, kneading was carried out using sodium lauryl sulfate instead of sodium lauryl benzene sulfonate to obtain a uniform transparent photosensitive resin composition. Next, using the obtained photosensitive resin composition, a photosensitive resin relief printing plate having good plate reproducibility was prepared by a photosensitive resin relief printing plate manufacturing method, and printed using a flexo rotary press in the same manner as in Example 1 to obtain an ink. A sharp print with no swelling and little image thickening was obtained. Also, this photosensitive resin relief printing plate is 25
After storage at 80 ° C. for 30 days, there was no chipping of the photosensitive resin relief image portion even after printing for 20,000 copies.

Similarly, the water development rate was measured by the water developability measuring method, the water swelling rate and the IPA swelling rate were measured by the swelling rate measuring method, the tensile elongation was measured by the tensile elongation measuring method, and the tensile elongation after humid aging was measured. Strong elongation was obtained and the results are shown in Table 1.

[0068]

Example 3 In step (3) of Example 1, kneading was carried out using sodium α-olefin sulfonate instead of sodium laurylbenzenesulfonate to obtain a homogeneous and transparent photosensitive resin composition. Next, using the obtained photosensitive resin composition, a photosensitive resin relief printing plate having good plate reproducibility was prepared by a photosensitive resin relief printing plate manufacturing method, and printed using a flexo rotary press in the same manner as in Example 1 to obtain an ink. A sharp print with no swelling and little image thickening was obtained. Also, after storing this photosensitive resin relief plate at 25 ° C. and 80% for 30 days, there was no chipping of the photosensitive resin relief image portion even after printing 20,000 copies.

Similarly, the water development rate was measured by the water developability measuring method, the water swelling rate and the IPA swelling rate were measured by the swelling rate measuring method, the tensile elongation was measured by the tensile elongation measuring method, and the tensile elongation after humid aging was measured. Strong elongation was obtained and the results are shown in Table 1.

[0070]

Example 4 In step (3) of Example 1, the content of sodium laurylbenzenesulfonate was reduced to half and kneaded to obtain a homogeneous and transparent photosensitive resin composition. Next, using the obtained photosensitive resin composition, a photosensitive resin relief printing plate having good plate reproducibility was prepared by a photosensitive resin relief printing plate manufacturing method, and printed using a flexo rotary press in the same manner as in Example 1 to obtain an ink. A sharp print with no swelling and little image thickening was obtained. Also, this photosensitive resin letterpress was used at 25 ° C and 80% for 30 days.
After storage for one day, there was no chipping in the photosensitive resin relief image portion even when printing was good and 20,000 copies were printed.

Similarly, the water development rate was measured by the water developability measuring method, the water swelling rate and the IPA swelling rate were measured by the swelling rate measuring method, the tensile elongation was measured by the tensile elongation measuring method, and the tensile elongation after humid aging was measured. Strong elongation was obtained and the results are shown in Table 1.

[0072]

Example 5 29.5 g of the sulfonic acid group-containing polyurethane obtained in step (2) of Example 1 was heated at 150 ° C. in a nitrogen atmosphere.
Using a pressure kneader, 20 g of a styrene-isoprene block copolymer [Califlix TR1107: manufactured by Shell Chemical Co., Ltd.] and 20 g of a thermoplastic polyurethane resin [Elastollan ET680: Takeda Birdish Urethane]
｛Or more (B) component / (A) component (weight ratio) = 136/1
00｝, 2 g of sodium laurylbenzenesulfonate,
｛(C) component / (A) + (B) component (weight ratio) = 2.9
/ 100} methacrylate-modified polybutadiene [MM-
1000-80: Nippon Petrochemical] 10 g, polybutadiene diacrylate [BAC-45: Osaka Organic Chemical]
3 g, phenoxyethyl methacrylate 3.6 g, dioctyl fumarate 2.7 g, lauryl maleimide 2.5
g ｛or more (D) component / (A) + (B) component (weight ratio) =
31.4 / 100%, 1.8 g of 2,2′-dimethoxyphenylacetophenone {weight ratio of (E) component / (A) + (B) = 2.6 / 100}, polystyrene oligomer [picola stick A5: Rika Hercules 3 g of liquid polybutadiene [B-2000: manufactured by Nippon Petrochemical].
5 g, 2,2-di-t-butyl-p-cresol 0.1
g and kneaded to obtain a uniform and transparent photosensitive resin composition.

Next, using the obtained photosensitive resin composition,
A photosensitive resin relief plate having good plate reproducibility was prepared by the photosensitive resin relief printing plate manufacturing method, and printing was performed by a flexographic rotary press in the same manner as in Example 1. As a result, a sharp printed matter without swelling due to ink and having a small image thickness was obtained. Was. Also, after storing this photosensitive resin relief plate at 25 ° C. and 80% for 30 days, there was no chipping of the photosensitive resin relief image portion even after printing 20,000 copies.

Similarly, the water development rate was measured by the water developability measuring method, the water swelling rate and the IPA swelling rate were measured by the swelling rate measuring method, the tensile elongation was measured by the tensile elongation measuring method, and the tensile elongation after humid aging was measured. Strong elongation was obtained and the results are shown in Table 1.

[0075]

[Table 1]

[0076]

Since the photosensitive resin composition of the present invention contains a thermoplastic elastomer and a surfactant, it does not chip even when printed after being stored for a long time at a high temperature and high humidity. It has excellent water developability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/035 G03F 7/035

Claims (2)

[Claims] (A) (a) at least one diol selected from the group consisting of a sulfonic acid group-containing polyamide diol and a sulfonic acid group-containing polyester diol,
(B) a dihydroxy hydrocarbon having a number average molecular weight of 400 to 4,000, and (c) a sulfonic acid group-containing polyurethane synthesized from diisocyanate, (B) a thermoplastic polymer, (C) a surfactant, (D A) a photosensitive resin composition containing an ethylenically unsaturated compound and (E) a photopolymerization initiator, wherein the weight ratio of the component (B) to the component (A) is 10/100 to 300/100; ) And (B)
The weight ratio of the component (C) to the total amount of the components is 0.1.
The weight ratio of the component (D) to the total amount of the components (A) and (B) is from 5/100 to 100/100.
200/100, and the weight ratio of the component (E) to the total amount of the components (A) and (B) is 0.1 / 100 to 30.
The photosensitive resin composition for a printing plate, wherein the ratio is in the range of / 100. 2. The photosensitive resin composition for a printing plate according to claim 1, wherein the surfactant (C) is an anionic surfactant.