JPH0450849A - Photosensitive resin composition for flexographic printing plate - Google Patents

Abstract

PURPOSE:To obtain the flexographic printing plate which is improved in printing resistance and can be developed with water by forming this printing plate of resin component which are specific thermoplastic elastomers, an ethylenic unsatd. compd. and/or plasticizer component, at least a part of which is carboxylate, and a gelatinizing agent which is a specific compd. CONSTITUTION:The thermoplastic elastomer of >= 10000 number average mol. wt. having >= 3C alkylene oxide bond are selected for the resin components and these resin components are nonuniformly dispersed into the photosensitive resin compsn., by which the use of a large amt. of the resin components is allowed. The carboxylate compd. is used as at least a part of the ethylenic unsatd. compd. and/or plasticizer component, by which water developability is imparted to the comps. The gelatinizing agent imparts a shape retaining property to the compsn. as this agent is formed by using at least one kind of the compds. selected from the group of benzylidene sorbitols, etc. The flexographic printing plate which is improved in the printing resistance and can be developed with water is obtd. in this way.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photosensitive resin composition for printing plates, and in particular to water-developable flexographic printing plates with improved printing durability when using water-based inks. The present invention relates to a solid photosensitive resin composition for use.

[Prior art] Chlorinated rubber, styrene-butadiene block copolymer,
Using an elastomer such as polyurethane as a carrier resin component,
A photosensitive resin composition containing an ethylenically unsaturated compound and a photopolymerization initiator is useful as a flexographic printing plate material by taking advantage of the characteristics of an elastomer.
No. 948611, No. 3024180, Special Publication No. 51-4
Many proposals have been made, such as in Publication No. 3374.

However, such photosensitive resin solid plate materials require halogenated hydrocarbon development and have problems such as health problems and environmental pollution.

On the other hand, when considering photosensitive resin printing plates that are not particularly limited to flexographic printing applications, water- or alcohol-developable solid printing plates are well known;
As shown in Japanese Patent Publication No. 6-26125, Japanese Patent Publication No. 50-32645, Japanese Patent Publication No. 57-28485, etc., printing in which the photosensitive layer is a photosensitive resin composition whose carrier resin component is mainly water- or alcohol-soluble polyamide. The plate material is widely known. However, although printing plates obtained from such water- or alcohol-developable solid printing plate materials are resistant to oil-based inks, they are not resistant to inks containing polar solvents such as aqueous or alcohol-based. It is something that we do not have. In view of the above problems, the present inventors investigated the possibility of developing a photosensitive resin solid plate material that can be developed with water and is resistant to inks containing polar solvents such as water-based or alcoholic solvents. As a result, we have developed a method in which a large amount of photocurable components, which are mainly liquid components, are gelled and solidified using a small amount of a specific resin component, and furthermore, a specific component known as an organic solvent gelling agent, to form the desired photosensitive resin solid. He discovered that it was possible to obtain plate materials (for example, JP-A-63-278053 and JP-A-63-2).
87845, etc.).

[Problems to be Solved by the Invention] The purpose of the present invention is to solve the problems of
To provide a photosensitive resin solid plate material that is particularly water-developable and provides a water-developable flexographic printing plate with particularly improved printing durability by developing and improving the technology presented in Publication No. 3-287845. It is in.

[Means for Solving the Problems] The object of the present invention is to provide a photosensitive resin composition for printing plates comprising a resin component, an ethylenically unsaturated compound, a plasticizer component, a gelling agent, and a photopolymerization initiator. , the resin component is a thermoplastic elastomer having a number average molecular weight of 10,000 or more and having an alkylene oxide bond having 3 or more carbon atoms, at least a part of the ethylenically unsaturated compound and/or the plasticizer component is a carboxylic acid salt, and gelation is achieved. This is achieved by a solid photosensitive resin composition for a flexographic printing plate, characterized in that the agent is at least one compound selected from the group of benzylidene sorbitols, benzylidene xylitols, and N-acylamino acid derivatives.

That is, the present inventors solidified or toughened a large amount of ethylenically unsaturated compound with a small amount of a specific resin, which had not been thought of as a solid plate material, and applied this to a photosensitive resin composition. It was discovered that the photosensitive resin printing plate material has excellent developability and is suitable for a wide range of inks. Improvements to this printing plate material, especially water-based ink, which is the main ink for flexographic printing, have been developed. As we further investigated the improvement of printing durability during use, we selected a thermoplastic elastomer component with a number average molecular weight of 10,000 or more that has an alkylene oxide bond with 3 or more carbon atoms as a resin component, and combined these resin components into a photosensitive resin composition. By unevenly dispersing the resin component in the photosensitive resin composition, it is possible to use a large amount of the resin component, and the printing durability of the printing plate obtained from the photosensitive resin composition of the present invention can be improved. Water developability is imparted to the photosensitive resin composition by using a carboxylate compound as at least a part of the plasticizer component, and shape retention of the photosensitive resin composition is imparted by using a specific gelling agent. The present invention was achieved by discovering that the present invention can be made into an ideal water-developable solid photosensitive resin composition for flexographic printing plates.

The thermoplastic elastomer component having a number average molecular weight of 10,000 or more and having an alkylene oxide bond having 3 or more carbon atoms and used as the main resin component in the present invention includes:
For example, thermoplastic elastomers having an alkylene oxide bond having 3 or more carbon atoms and a number average molecular weight of 10,000 or more, such as poly(1,2- and 1,3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly( Polyether ester elastomer obtained by polycondensing or copolycondensing glycol (hexamethylene oxide) or block or random copolymers thereof as at least part of the raw material components (for example, JP-A 1972-
29896, etc.), polyether ester amide elastomers (e.g., Japanese Patent Publication No. 2-371, etc.), polyether urethane elastomers (e.g., Japanese Patent Application Laid-open No. 49-1
09105, etc.), and furthermore, using a diamine obtained by cyanoethylating both ends of the diols mentioned above and then hydrogenating the diamine as at least a part of the raw diamine component (for example, JP-A-55-79437, etc.). ) Polyetheramide elastomers obtained by polycondensation or copolycondensation are used, but are not limited thereto.

The polyalkylene oxide segment, which is the soft segment of the elastomer used here, has a carbon number/oxygen number ratio of 2.5 or more and a number average molecular weight of 200 to 500.
0, preferably in the range of 300 to 3000. By satisfying this condition, the printing durability of the resulting flexographic printing plate can be improved.

In addition, epichlorohydrin rubber, which is a thermoplastic elastomer having a chlorine-substituted alkylene oxide bond and having a number average molecular weight of 10,000 or more, can also be preferably used as the resin component in the present invention, and specifically, epichlorohydrin polymer, epichlorohydrin-ethylene oxide copolymer, etc. , epichlorohydrin-propylene oxide copolymers, and/or copolymers of these with allyl or alkyl glycidyl ethers, and these epichlorohydrin rubbers are known (E., J., Vandenberg).
, J. Polymer, Sci., 47.486 (19
It can be synthesized according to the prescription of 60).
“HYDRIN” manufactured by Nippon Zeon Co., Ltd., “Zeospan” manufactured by Zeon Co., Ltd., “HE RCL” manufactured by Hercules Co., Ltd.
These elastomers can be used alone or in a mixture of two or more.Also, these elastomers can be used in combination with an elastomer containing the above-mentioned polyalkylene oxide segment as a soft segment. You may.

The effect of using these elastomers is to improve the printing durability of flexographic printing plates, which is the objective of the present invention, especially when using water-based ink, which is the main ink for flexographic printing, and from that perspective, the total amount of these elastomers used is When the amount is less than 10% by weight based on the photosensitive resin composition, the effect of improving printing durability is small, and when it exceeds 70% by weight, water developability is significantly reduced. From the viewpoint of achieving both water developability and printing durability, the amount of these elastomers used is preferably 10 to 70% by weight, more preferably 15 to 60% by weight, and still more preferably 20 to 50% by weight. .

In the present invention, the carboxylic acid component of the carboxylate salt used as at least a part of the ethylenically unsaturated compound includes all salt formers of a tertiary amine compound having one or more ethylenically unsaturated bonds. Although mono- or polyvalent carboxylic acids can be used, preferred carboxylic acid components that meet the purpose of the present invention include polyvalent carboxylic acids or acryloyl or methacryloyl derivatives of polyvalent carboxylic acids. It is a group-containing monoester. Specifically, maleic acid, fumaric acid,
Itaconic acid, mesaconic acid, adipic acid, sebacic acid, cyclohexane 1,2-dicarboxylic acid, 4-methylcyclohexane 1,2-dicarboxylic acid, isophthalic acid, 1.
2. 3. Ring-opening of 4-butanetetracarboxylic acid, 2-methacryloyloxyethyl phthalic acid, 2-acryloyloxyethyl phthalic acid, copolymers of methacrylic acid or acrylic acid, and hydroxyacrylic acid esters of maleic anhydride-modified polyenes. Examples include, but are not limited to, esters.

In addition, among the above carboxylic acid components, carboxylic acid components having one or more ethylenically unsaturated bonds can be used as a salt former of a tertiary amine compound that does not have an ethylenically unsaturated bond. etc. are used.

Further, in the present invention, the carboxylic acid component of the carboxylate salt used as at least a part of the plasticizer component is:
A tertiary amine compound having no ethylenically unsaturated bond and a salt of a carboxylic acid component having no ethylenically unsaturated bond among the above carboxylic acid components are used.

Although alkali metals such as lithium, sodium, and calcium can be used as salt-forming substances for the carboxylic acid component, amine compounds are preferably used.

The amine compound is not particularly limited, but tertiary amines are usually used, and the ethylenically unsaturated compound is prepared in the step of preparing the stock solution of the photosensitive resin composition of the present invention using a primary amine or a secondary amine as a raw material component. A method in which a tertiary amine is produced by reacting with the component acrylates or methacrylates is particularly preferably used, and in this method, usually,
A tertiary amine compound that functions as a plasticizer component and an ethylenically unsaturated compound having a tertiary amino group can be produced simultaneously.

As the tertiary amines, polyvalent amines having one or more hydroxyl groups in the molecule and having a molecular weight of 300 or more are preferably used, and specific examples include isophorone diamine, metaxylylene diamine, triethylenetetramine, diethylenetriamine, Alkyl glycidyl ether adducts, acrylate adducts, etc. from dimer acid amidoamine are preferably used, and their production methods are described in JP-A-63-16266.
This method is based on the method disclosed in No. 0 and Japanese Unexamined Patent Publication No. 01-69059.

The amount of carboxylic acid salt used is 1 for the total photosensitive resin composition.
The range is preferably 0 to 70% by weight, more preferably 20% by weight.
If it is less than 10% by weight, the water developability will be insufficient, and if it is more than 70% by weight, the shape retention of the photosensitive resin composition will be insufficient.

The gelling agent used in the present invention is at least one selected from the group of 12-hydroxystearic acid, benzylidene sorbitols, benzylidene xylitols, and N-acylamino acid derivatives, preferably xylitol or sorbitol substituted with an alkyl group. or unsubstituted benzaldehyde condensates, N-alkylamino acid alkylamides, and the like. Specifically, 1.3:2.4-dibenzylidene sorbitol, 1.
3:2,4:5,6-1 ribenzylidene sorbitol,
1.3:2.4-p-p'-ditolylidene sorbitol, 1.3:2.4-dibenzylidenexylitol, N-lauroyl-glutamic acid-α,γ-di-n
-Butyramide is a typical compound, but it is not limited to these, for example, JP-A-63-146030
N-acyl amino acid derivatives such as those shown in the above publication are widely used.

The amount of these gelling agents used is preferably in the range of 1 to 20% by weight, more preferably 2 to 10% by weight, based on the total photosensitive resin composition. The shape retention of the resin composition becomes insufficient, and if it exceeds 20% by weight, the flexibility of the photosensitive resin composition becomes insufficient.

The photosensitive resin composition of the present invention is characterized in that it contains the above-mentioned components, and the ethylenically unsaturated compound used as an essential component of the composition contains at least one ethylene in the molecule. Boiling point 10 with a double bond
It is a compound that can be photopolymerized at 0° C. or higher, and all known compounds can be used. For example, in addition to various alkyl monoacrylates and alkyl monomethacrylates, reaction products of alkylene glycol and acrylic acid and methacrylic acid, unsaturated epoxy compounds and carboxylic acids,
Mono- or polyvalent acrylates, mono- or polyvalent methacrylates, mono- or polyvalent acrylamides or methacrylamides, and mono- or polyvalent urethane acrylates or methacrylates synthesized by the reaction of unsaturated carboxylic acids and amines. Acrylates, polyene oligomers such as liquid polybutadiene, etc. are used, but are not limited to these, and are appropriately selected depending on the required characteristics of the intended molded product and in combination with the elastomer component. However, the ethylenically unsaturated compounds preferably used to obtain the water-developable flexographic printing plate material, which is the object of the present invention, have one or more hydroxyl groups in the molecule and Examples of such compounds include ethylenically unsaturated compounds having a hydroxyl equivalent in the range of 50 to 500, such as epichlorohydrin-modified bisphenol A diacrylate or epichlorohydrin-modified bisphenol A dimethacrylate as represented by the general formula below. (Hereinafter, both will be abbreviated as epichlorohydrin-modified bisphenol A di(meth)acrylate. In the following explanation, all descriptions of (meth)acrylate are abbreviated to include both acrylate and methacrylate.

), caprolactone-modified 2-hydroxyethyl (meth)
Acrylate, epichlorohydrin-modified propylene glycol di(meth)acrylate, propylene oxide-epichlorohydrin-modified (meth)acrylate, epichlorohydrin-modified butyl (meth)acrylate, epichlorohydrin-modified diethylene glycol di(meth)acrylate, epichlorohydrin-modified phenyl (meth)acrylate
acrylate, ethylene oxide modified phthalate (meth)acrylate such as β-hydroxyethyl β-acryloyloxyethyl phthalate, polycaprolactone modified (meth)acrylate, polyethylene oxide modified ethyl phthalate (meth)acrylate, polypropylene oxide modified ethyl phthalate Examples include (meth)acrylate, polypropylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate, etc., but are not limited to these, and other ethylenically unsaturated compounds having a hydroxyl group equivalent in the range of 50 to 500. can be widely used, and it is also possible to use two or more types together, and it is also possible to use them in combination with other ethylenically unsaturated compounds. In particular, among these compounds, mono(meth)acrylates are preferably used to obtain the flexographic printing plate material which is the object of the present invention.

The amount of such ethylenically unsaturated compounds having one or more hydroxyl groups in the molecule is not particularly limited, but is 5 to 100% by weight based on the total ethylenically unsaturated compounds.
Preferably it is 30 to 80% by weight.

Further, in order to obtain a flexographic printing plate material, which is the object of the present invention, urethane (meth)acrylates are mentioned as compounds preferably used as a part of the ethylenically unsaturated compound component, and in particular, those having a number average molecular weight of 1000 to 500
0 oligourethane polyvalent (meth)acrylates are preferably used, specifically, diisocyanates such as toluylene diisocyanate and isophorone diisocyanate, polyols, polyester diols, hydroxy (meth)acrylates, etc. are used as raw materials for synthesis. oligourethane di(meth)acrylates having a number average molecular weight of 1,000 to 5,000, and the use of such oligourethane (meth)acrylates improves the flexibility, which is preferable for the flexographic printing plate obtained from the composition of the present invention. It imparts rubber elasticity, polar solvent resistance, etc.

The amount of urethane (meth)acrylates used is not particularly limited, but is preferably 5 to 70% by weight, more preferably 10 to 70% by weight in the ethylenically unsaturated compound.
If the amount is less than 5% by weight, the addition effect will not appear, and if it is more than 70% by weight, the water developability of the flexographic printing plate material will be poor.

Further, as part of the ethylenically unsaturated compound component of the present invention, polybutadiene having a number average molecular weight of 500 to 3,000 or a modified product thereof with maleic anhydride and hydroxyacrylate or hydroxymethacrylate, or a modified product such as a terminal-acrylic-introduced product is used. Furthermore, polyisoprene having a number average molecular weight of 1,000 to 30,000, modified products thereof with maleic anhydride and hydroxyacrylates or hydroxymethacrylates, or modified products with acrylic terminals can be used. These polyenes are unevenly dispersed together with the resin component used in the present invention in the photosensitive resin composition, and provide preferable printing durability to the flexographic printing plate obtained from the photosensitive resin composition of the present invention. Here, the amount of nonuniform dispersion of resin components, polyene, etc. can be easily observed and quantified from the difference in the degree of staining of an SEM (scanning electron microscope) backscattered electron image of any cross section of the photocured product after staining with osmic acid. However, the amount of non-uniform dispersion in the photosensitive resin composition of the present invention can be regarded as an island component in the form of a sea-island, and it can be used as a water-developable flexographic printing plate material, which is the main objective of the present invention. The amount of non-uniform dispersion that provides excellent printing durability is preferably 20 to 70% by volume, more preferably 30 to 65% by volume.
, more preferably 40 to 60% by volume.

As the photopolymerization initiator for rapidly photopolymerizing the composition of the present invention, all conventionally known compounds can be used. Examples include benzoin alkyl ethers, benzophenones, anthraquinones, benzyls, acetophenones, and diacetyls. These photopolymerization initiators are used in an amount of 0.01 to 10% based on the total photosensitive resin composition.
Can be used within a range of parts by weight. As the plasticizer component of the photosensitive resin composition of the present invention, all conventionally known compounds such as alkylbenzenesulfonamides and alkylene glycols can be used. The use of compounds having a grade amine bond and one or more hydroxyl groups or their carboxylic acid salts as described above is effective in improving molding processability and properties of molded products as well as plasticizing effects. The addition improves the stability of the photosensitive resin composition of the present invention when it is imitated, and also improves the image of the printing plate obtained from the photosensitive resin composition of the present invention. In particular, in such amine compounds, the molecular weight is 300 to 300.
0. Furthermore, compounds of 700 to 2000 are preferably used. When using such an amine additive, it is also preferable to add an active hydrogen-containing amine to form a tertiary amine during composition preparation.

Further, in order to increase the thermal stability of the photosensitive resin composition of the present invention, all conventionally known polymerization inhibitors can be used.

Preferred polymerization inhibitors include phenols, hydroquinones, catechols, and phenothiazine. These heat stabilizers are added to the total composition at a concentration of 0.
It can be used in a range of 0.001 to 5% by weight. Other additives that can be added include dyes, pigments, surfactants, antifoaming agents, ultraviolet absorbers, and fragrances. In particular, the use of carboxylated polyoxyethylene alkyl ether or its derivatives is effective in improving the water developability of the photosensitive resin printing plate material of the present invention.

The method for producing the photosensitive resin composition of the present invention and (-,
First, a resin component such as an elastomer is added to an ethylenically unsaturated compound mixed with a liquid component such as a plasticizer, and the mixture is stirred for 7 hours.
After melting and dispersing the resin component by heating to 0 to 200°C, preferably 100 to 180°C, a photopolymerization initiator,
Other additive components are mixed and dissolved to produce a substantially solvent-free molten dispersion (dissolution) liquid. A primary or secondary amine compound as a reactive plasticizer component may be added at this stage. This solution can be cast or cast and cooled to directly obtain a molded product. The photosensitive resin composition of the present invention is characterized by being substantially a thermoreversible gel, and is a solid with practical strength at room temperature, but becomes a relatively low-viscosity liquid when heated. Therefore, an easy molding method that takes advantage of this property can be applied. The photosensitive resin composition of the present invention can be designed to be a fluid with 100 voids or less at 150°C, and further to be a fluid with 100 voids or less at 120°C.

In order to form a printing plate material using the photosensitive resin composition of the present invention, for example, a solution of the composition can be directly cast onto a support or a cover film. If necessary, dry film formation may be performed if a solvent is used, but normally it is formed without a solvent, so
Photosensitive resin sheets can be produced only by cooling, and thick objects can be easily molded. Generally, it is preferable to form a thin film layer mainly composed of water-soluble or dispersible resin on the upper surface of the photosensitive resin sheet in order to improve the adhesion with the negative film.

As a support, a metal plate made of steel, stainless steel, aluminum, copper, etc., which has an adhesive layer if necessary, a plastic sheet such as a polyester film, a synthetic rubber sheet, etc. is used, and the photosensitive layer is usually 0.1 to 10 mm thick.
formed to a thickness of

In order to form a relief image for printing using the photosensitive resin composition of the present invention, a negative or positive original film is closely adhered to the photosensitive layer prepared as described above, and a wavelength of 300 to 450 mμ is usually centered on the photosensitive layer. UV rays from a high-pressure mercury lamp, ultra-high-pressure mercury lamp, metal halide lamp, xenon lamp, chemical lamp, power-bonarch lamp, etc. are irradiated to cause curing through a photoreaction. A relief is then formed on the support by dissolving or dispersing the uncured portion in water using a spray or brush developing device.

After drying this, a flexographic printing plate can be obtained by treating it with actinic light in the atmosphere.

The photosensitive resin composition of the present invention has the characteristic that it contains a large amount of elastomer component, which could not be used as a water-developable printing plate material in the past, so it can be used as a water-developable flexographic printing plate with improved printing durability. It is.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

Note that the numbers used in the following examples are parts by weight.

Synthesis Example 1 A copolyamide comprising the following components was synthesized based on a known recipe (for example, JP-A-55-79437).

ε-caprolactam / Equimolar salt of hexamethylene diamine and adipic acid / Equimolar salt of α,ω-diaminopropylpolyoxyethylene (number average molecular weight 1000) and adipic acid = 20/20/60 Copolymerized polyamide obtained here When the terminal group of is quantified, the primary amino group is 4.0XIO-'
Mol/g.

Carboxyl group 2. lXl0-5 mol/g, and the number average molecular weight as determined by the terminal group assay was approximately 33,000.

Synthesis Example 2 A polyether ester elastomer consisting of the following components was synthesized based on a known formulation (for example, JP-A-48-29896).

Dimethyl terephthalate/dimethyl isophthalate nia 0/30 (weight ratio) and equivalent polytetramethylene glycol/1,4-butanediol = 50/40 (weight ratio) Polystyrene equivalent GPC number of the polyether ester elastomer obtained here The average molecular weight was 28,000, the glass transition temperature was -60°C, and the Shore D hardness was 40.

Synthesis Example 3 A polyether ester amide elastomer comprising the following components was synthesized based on a known formulation (for example, Japanese Patent Publication No. 2-372).

Laurolactam/Equimolar adipic acid mixture with poly(tetramethylene oxide) glycol having a number average molecular weight of 650 = 40/70 The number average molecular weight of the polyether ester amide elastomer obtained here is 1500 in terms of GPC nylon 6.6.
It is 0.

Synthesis example 4 Known formulation (E. J. Vandenberg.

Epichlorohydrin rubber having a GPC number average molecular weight of 32,000 in terms of polyethylene glycol was synthesized based on J. Poly, Sci., 47, 486 (1960).

Synthesis Example 5 1 mol of isophorone diamine and 2-
Ethylhexyl glycidyl ether 1 mole adduct (
70°C, 3 hours reaction) was synthesized.

In the following examples, this compound reacts with the acrylate component in the stock solution preparation step to create a tertiary amine bond within the molecule.
This product simultaneously provides an ethylenically unsaturated compound component and a plasticizer component having two or more components, and these products form a salt with the carboxylic acid component of the raw material component.

Example 1 25 parts of the polyetheresteramide elastomer obtained in Synthesis Example 3, 0.05 part of heat stabilizer hydroquinone, 15 parts of caprolactone-modified 2-hydroxyethyl methacrylate, 15 parts of β-hydroxyethyl β'-acryloyloxyethyl phthalate. part, urethane acrylate (
5 parts of XP2O00B (manufactured by Nippon Gosei Co., Ltd.), 10 parts of sebacic acid, and 20 parts of maleic anhydride-modified polybutadiene (M2O0O-20, manufactured by Nippon Petrochemical Co., Ltd.) were mixed, heated, and heated to 105°C. After stirring for an hour, 10 parts of the additive shown in Synthesis Example 5 was added, and after stirring at 140°C for 1 hour, 1.5 parts of benzyl dimethyl ketal was added as a photopolymerization initiator, and as other additive components. , carboxylated tetra(oxyethylene) lauryl ether 4
1 part, 5 parts of dibenzylidene sorbitol, 3 parts of N-lauroyl-L-glutamic acid-α・γ-di-n-butylamide
part was added and dissolved. The solution obtained in this way is
A photosensitive layer with a thickness of 1 μm is placed on a 100 μm thick polyester substrate on which a polyester adhesive has been applied and cured in advance.
A solid photosensitive resin printing plate material was obtained by casting and coating to a thickness of 700 μm and allowing it to stand at room temperature. On the photosensitive layer of this printing plate material, a gray scale negative film (Stou
Made by ffer, 21Steps 5ensitivi
tyGuide) and a negative film for evaluating image reproducibility (150 lines, 3%, 5%, 10% halftone dots, 200μ and 300μ diameter independent points, widths of 50 and 70μ thin lines) were vacuum-adhered and heated for 1 m using a 2KW ultra-high pressure mercury lamp. from a distance of 3
Exposure was made for a minute.

After the exposure was completed, development was performed using a brush type washing machine (liquid temperature: 30° C.) containing neutral water. Depth 1000 in 8 minutes development time
A relief image of μ was formed. As a result of evaluating this relief image, it was found that up to 13 steps remained in the gray scale area, and that the image area had almost completely reproduced 5% halftone dots, 300μ independent points, 50μ fine lines, etc. The hardness of the printing plate was 60 Shore A hardness after the post-exposure to actinic light. 500 prints using water-based ink using this printing plate.
A flexographic printing test was conducted on 00 sheets and good printed matter was obtained.

Comparative Example 1 In Example 1, a photosensitive resin printing plate material was similarly obtained by using the copolyamide obtained in Synthesis Example 1 instead of the polyetheresteramide elastomer obtained in Synthesis Example 3. In the same printing test as in Example 1, the printing plate obtained from this printing plate material showed remarkable thickening in the print area.

Comparative Example 2 In Example 1, 5 parts of dibenzylidene sorbitol,
N-lauroyl-glutamic acid-α・γ-di-n-
A photosensitive resin printing plate material was similarly obtained without using 3 parts of butylamide, but this printing plate material did not have practical shape retention as a solid printing plate material.

Comparative Example 3 A photosensitive resin printing plate material was similarly obtained in Example 1 without using 10 parts of the additive shown in Synthesis Example 5, but this printing plate material showed almost no water developability.

Example 2 3 parts of the copolyamide obtained in Synthesis Example 1 and 20 parts of the polyetherester elastomer obtained in Synthesis Example 2 were
-20 parts of hydroxyethyl β'-acryloyloxyethyl phthalate, 12 parts of sebacic acid, 0.05 part of heat stabilizer hydroquinone, 15 parts of caprolactone-modified 2-hydroxyethyl methacrylate, and liquid polybutadiene (
“8 stone polybutadiene” M2O manufactured by Nippon Petrochemicals Co., Ltd.
0O-20) was added to a mixture of 20 parts, stirred and heated at 1100C for 1 hour, then the additive component obtained in Synthesis Example 5 was added, and the mixture was further heated at 140'C.

After heating and stirring for 1 hour, 1.5 parts of benzyl dimethyl ketal as a photopolymerization initiator, 5 parts of carboxylated tetra(oxyethylene) lauryl ether as an additive,
12-hydroxystearic acid 2 as a gelling agent component
1 part, and 5 parts of dibenzylidene sorbitol were added and dissolved. The solution obtained in this way is cast onto a 100μ thick polyester substrate on which a polyester adhesive has been applied and cured in advance so that the photosensitive layer has a thickness of 1500μ, and the coating is left at room temperature. A solid photosensitive resin printing plate material was obtained.

A printing plate was obtained from this printing plate material in the same manner as in Example 1. The Shore A hardness of this printing plate was 64, making it an excellent flexographic printing plate suitable for water-based inks.

Example 3 In Example 1, epichlorohydrin rubber 1 obtained in Synthesis Example 4 was used instead of 20 parts of maleic anhydride-modified polybutadiene (M2O0O-20, manufactured by Nippon Petrochemical Co., Ltd.).
A printing plate material was obtained in the same manner using 5 parts of urethane acrylate and 10 parts of urethane acrylate. A printing plate was produced from this printing plate material in the same manner as in Example 1. This printing plate is Example 1
Compared to the printing plate obtained in the above, the suitability for printing using flexo ink was even better, and good printed matter was obtained in a 100,000-sheet printing test using water-based ink.

Example 4 In Example 1, dimer acid amide amine (Daiichi General Co., Ltd.) was used instead of 10 parts of the additive shown in Synthesis Example 5.
A printing plate material having properties similar to those of Habo was obtained using 7 parts of "Persamide" 125) manufactured by Habo.

Example 5 In Example 1, 10 parts of 4-methylhexahydrophthalic acid was used instead of 10 parts of sebacic acid to obtain a printing plate material having properties similar to Habo.

[Effects of the Invention] Since the present invention is constructed as described above, it is possible to provide a photosensitive resin composition that provides a water-developable flexographic printing plate material with excellent resistance to flexographic printing using water-based ink. .

Claims (1)

[Claims] 1. A resin component, an ethylenically unsaturated compound, a plasticizer component,
A photosensitive resin composition for printing plates comprising a gelling agent and a photopolymerization initiator, in which the resin component is a thermoplastic elastomer having an alkylene oxide bond with 3 or more carbon atoms and a number average molecular weight of 10,000 or more, and is an ethylene-based non-ethylene-based resin composition. At least a portion of the saturated compound and/or plasticizer component is a carboxylic acid salt, and the gelling agent is at least one selected from the group of 12-hydroxystearic acid, benzylidene sorbitols, benzylidene xylitols, and N-acylamino acid derivatives. A solid photosensitive resin composition for a flexographic printing plate, which is a seed compound. 2. The flexographic printing according to claim 1, wherein the carboxylic acid salt that is at least a part of the ethylenically unsaturated compound and/or the plasticizer component is a salt formed from a polyvalent carboxylic acid and a polyvalent amine. Solid photosensitive resin composition for plates. 3. The solid photosensitive resin composition for a flexographic printing plate according to claim 1, wherein at least a part of the ethylenically unsaturated compound component is urethane acrylate or methacrylate.