JP3372215B2 - Photosensitive resin composition and resin plate for flexographic printing - Google Patents

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, and more specifically to a photosensitive resin composition suitable for a photosensitive resin plate for aqueous flexographic printing, and for flexographic printing using the photosensitive resin composition. Regarding resin plate.

[0002]

2. Description of the Related Art Conventionally, as a photosensitive resin composition for forming a photosensitive resin layer of a photosensitive resin plate for flexographic printing, a thermoplastic elastomer having a proper impact resilience, a photopolymerizable unsaturated monomer and a light-sensitive resin are used. A photosensitive resin composition comprising a polymerization initiator has been used. As the thermoplastic elastomer, for example, styrene-based resins such as styrene / isoprene / styrene and styrene / butadiene / styrene have been used. Since the thermoplastic elastomer is hydrophobic, it is eluted with water or an aqueous solvent. However, chlorine-based organic solvents such as chloroform, trichloroethane, trichloroethylene, and tetrachloroethylene were used exclusively. However, such a chlorine-based organic solvent is
It is not flammable, easy to handle, and highly stable,
Not only is it highly toxic to the human body and poses a sanitary problem, but it is not preferable from the viewpoint of the working environment.

[0003]

In order to solve the drawbacks of the conventional photosensitive resin composition, a water-soluble photosensitive resin composition containing polyvinyl alcohol or water-soluble nylon as a resin component has been proposed. It has a low impact resilience and is unsuitable as a printing plate material for printing thick printing materials such as corrugated cardboard and has a drawback that water-based ink cannot be used. Therefore, as a photosensitive resin composition having water developability and high impact resilience, an acid value of 30 mgKOH
/ G or more and a polymer having a carboxyl group having a glass transition temperature of 30 ° C or more, a compound having two isocyanate groups in one molecule and a compound having two hydroxyl groups in one molecule, which are obtained by reacting as essential components Resin,
The present inventors proposed a photosensitive resin composition containing a photopolymerizable unsaturated monomer and a photopolymerization initiator in JP-A-8-36263. The photosensitive resin composition has water developability and is excellent in impact resilience, but in addition to poor water resistance of the cured portion that becomes the line pattern portion of the printing plate material, low ink resistance, and further resistance to There was the problem of poor printability.

However, the above-mentioned Japanese Unexamined Patent Publication No. 8-36263.
Since the photosensitive resin composition described in JP-A No. 1993-09242 has excellent properties such as water developability and high impact resilience which are not present in conventional photosensitive resin compositions, it is necessary to modify the photosensitive resin composition described in the above-mentioned publication. Based on the idea that an excellent photosensitive resin composition can be obtained, the inventors of the present invention have conducted extensive studies,
As the resin component of the photosensitive resin composition, the acid value is 30 mgK
Polymer having a carboxyl group having a glass transition temperature of 30 ° C. or more at OH / g or more, a compound having two isocyanate groups in one molecule, a compound having two hydroxyl groups in one molecule, and one in one molecule The present invention has been completed by finding that it is preferable to use a resin obtained by reacting a photopolymerizable unsaturated monomer having a hydroxyl group.

That is, an object of the present invention is to provide a photosensitive resin composition which is water-developable and has high sensitivity.

Another object of the present invention is to provide a resin plate for flexographic printing, which is excellent in impact resilience and is also excellent in water resistance, ink resistance and printing resistance of a line pattern portion.

[0007]

Means for Solving the Problems The present invention which achieves the above object, comprises: (A) a polymer having a carboxyl group having an acid value of 30 mgKOH / g or more and a glass transition temperature of 30 ° C. or more; Obtained by reacting a compound having two isocyanate groups therein, (C) a compound having two hydroxyl groups in one molecule, and (D) a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule. The present invention relates to a photosensitive resin composition containing a resin and a photopolymerization initiator, and a resin plate for flexographic printing using the photosensitive resin composition.

The present invention will be described in detail below. The component (A) used in the photosensitive resin composition of the present invention has an acid value of 30 mg.
There is no particular limitation as long as it is a polymer having a KOH / g or more, a glass transition temperature of 30 ° C. or more, and a carboxyl group, and the production method thereof is not particularly limited, and it can be produced by any conventionally known method. For example, a method of copolymerizing a monomer having a carboxyl group and an unsaturated monomer can be used. The monomer having a carboxyl group,
Specific examples thereof include acrylic acid, methacrylic acid, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, itaconic acid, itaconic acid monoester, and cinnamic acid. The monomer having a carboxyl group,
You may use individually or in combination of 2 or more types.

The unsaturated monomer to be copolymerized with the above-mentioned monomer having a carboxyl group is a methacrylic acid ester-based monomer, an aromatic vinyl-based monomer, or other copolymerizable with these monomers. Vinyl-based monomers of By using the unsaturated monomer, the glass transition point of the component (A) becomes 30 ° C. or higher. Particularly, it is preferable to use only the methacrylic acid ester-based monomer and the aromatic vinyl-based monomer because a printing resin plate having high impact resilience can be formed when the photosensitive resin composition is exposed to light. Above all, it is preferable to use an acrylic polymer because a printing resin plate having high repulsive elasticity and high transparency can be obtained. Specific examples of the methacrylic acid ester-based monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, and n-methacrylate.
-Methacrylic acid alkyl esters such as octyl, dodecyl methacrylate, stearyl methacrylate; methacrylic acid aryl esters such as benzyl methacrylate; methacrylic acid substituent-containing alkyl esters such as glycidyl methacrylate, methacrylic acid 2-amino ester; Methacrylic acid derivatives such as methoxyethyl methacrylate and ethylene oxide adduct of methacrylic acid;
Perfluoromethyl methacrylate, perfluoroethyl methacrylate, perfluoropropyl methacrylate, perfluorobutyl methacrylate, perfluorooctyl methacrylate, 2-perfluoroethylethyl methacrylate, 2-perfluoromethyl-2-perfluoromethacrylate Oroethyl methyl, triperfluoromethyl methyl methacrylate, 2-perfluoroethyl methacrylate-
Fluorine-containing methacrylic acid esters such as 2-perfluorobutylethyl, 2-perfluorohexylethyl methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluorohexadecylethyl methacrylate; 2-hydroxyethyl methacrylate. 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, monomethacrylic acid ester of polyethylene glycol, monomethacrylic acid ester of polypropylene glycol, polycaprolactone modified product of 2-hydroxyethyl methacrylate (manufactured by Daicel Chemical Industries, Ltd .: A hydroxyl group-containing addition-polymerizable monomer such as a product name “Placcel F series”) can be used. The methacrylic acid ester-based monomers may be used alone or in combination of two or more kinds.

The aromatic vinyl-based monomer may be a conventionally known aromatic vinyl-based monomer and is not particularly limited, but specific examples include styrene, α-methylstyrene and o-.
Methyl styrene, m-methyl styrene, p-methyl styrene, chlorostyrene, styrene sulfonic acid and its sodium salt are mentioned. The aromatic vinyl monomers may be used alone or in combination of two or more.

In addition to the above methacrylic acid ester-based monomer and aromatic vinyl-based monomer, other vinyl-based monomers copolymerizable with a monomer having a carboxyl group can be used.
Specific examples of the other vinyl monomers include acrylic acid monomers such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate; 2-hydroxyethyl acrylate, acrylic acid 2-hydroxypropyl, 3-hydroxypropyl acrylate, monoacrylic acid ester of polyethylene glycol, monoacrylic acid ester of propylene glycol, polycaprolactone modified product of 2-hydroxyethyl acrylate (manufactured by Daicel Chemical Industries, Ltd .: trade name "Plaxel F series") and other hydroxyl group-containing addition polymerizable monomers; (meth) acrylic alcohol 4-hydroxymethylstyrene and other hydroxyl group-containing addition polymerizable monomers; maleic anhydride,
Dialkyl ester of maleic acid; Dialkyl ester of fumaric acid; Fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, vinylidene fluoride; Vinyl alkyloxysilyl group such as vinyltrimethoxysilane, vinyltriethoxysilane Vinyl monomers; maleimide derivatives such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide; nitrile group-containing vinyls such as acrylonitrile and methacrylonitrile. Amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl acetate, vinyl propionate, vinyl bivalate, and vinyl acetate Kosan, vinyl esters such as cinnamate vinyl, ethylene, alkenes such as propylene, butadiene, dienes such as isoprene; vinyl chloride, vinylidene chloride, and acrylic chloride. The other vinyl monomers may be used alone or in combination of two or more.

The component (A) has an acid value of 30 mgK.
OH / g or more, 80 mgKOH / g or more, preferably 9
0 mgKOH / g or more, more preferably 100 mgK
OH / g or more, most preferably 120 mgKOH / g or more and 300 mgKOH / g or less. In addition to the above-mentioned monomer having a carboxyl group, an acidic monomer having an acidic functional group can be used to impart the acid value. As the acidic monomer,
For example, styrene sulfonic acid, 2-acrylamido-2-
Methylpropanesulfonic acid, 2-methacrylamide-2
-Methyl propane sulfonic acid, 2-sulfoethyl methacrylate, 2-sulfoethyl acrylate, vinyl sulfonic acid, acrylic sulfonic acid, methacryl sulfonic acid and the like can be mentioned. The acidic monomers may be used alone or in combination of two or more.

The component (A) of the present invention is produced by polymerizing each of the above components by a known polymerization method such as radical polymerization, anionic polymerization or cationic polymerization. Particularly, when a methacrylic acid ester-based monomer or an aromatic vinyl-based monomer is used as the unsaturated monomer to be copolymerized with the monomer having a carboxyl group, radical polymerization or anion polymerization is preferable. The radical polymerization initiator used in the radical polymerization method is not particularly limited, and examples thereof include isobutyl peroxide, cumyl peroxyneodecanoate, diisopropyloxydicarbonate and di-n-.
Propyl peroxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, t-hexyl peroxy neodecanoate, t-butyl peroxy neodecanoate, t -Hexyl peroxypivalate, t-
Butyl peroxypivalate, 3,5,5-trimethylhexanoyl peroxide, decanoyl peroxide,
Lauroyl peroxide, cumyl peroxyoctate, succinic acid peroxide, acetyl peroxide, t
-Butyl peroxy (2-ethyl hexanate), m-
Toluoyl peroxide, benzoyl peroxide, t
-Butyl peroxyisobutyrate, 1,1-bis (t
-Butylperoxy) cyclohexane, t-butylperoxymaleic acid, t-butylperoxylaurate,
Cyclohexanone peroxide, t-butyl peroxyisopropyl carbonate, 2,5-dimethyl-2,5
-Di (benzoylperoxyhexane), t-butylperoxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n
-Butyl-4,4-bis (t-butylperoxy) valerate, di-t-butylperoxyisophthalate, methyl ethyl ketone peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexane, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, diisobutylbenzene hydroperoxide, di-t-butylperoxide, p-menthane hydro. Peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,1,3,3-tetramethylbutylhydroperoxide, cumene hydroperoxide, t-butylhydroper Organic peroxides such as oxides; hydrogen peroxide, potassium persulfate, sodium persulfate, ammonium persulfate Which inorganic peroxides; 2,2 '
-Azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2-cyclopropylpropionitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2, 2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2- (carbamoylazo) isobutyronitrile , 2-phenylazo-4-methoxy-2,4-
Dimethylvaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), 2,
2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2'-azobis (isobutyramide) dihydrate, 4,4'-azobis (4
-Cyanopentanoic acid), 2,2'-azobis (2-cyanopropanol) and other azo compounds; hydrogen peroxide-Fe
(II) salt, persulfate-sodium bisulfite, cumene hydroperoxide-Fe (II) salt, redox initiator such as benzoyl-dimethylaniline peroxide; and photosensitization such as diacetyl, dibenzyl, acetophenone An agent can be mentioned.

Examples of the polymerization mode include bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and solid phase polymerization. Further, the raw material monomer and the radical polymerization initiator may be charged all at once, or the respective components may be supplied to the polymerization container as occasion demands to carry out the polymerization. Further, a part of the solvent may be charged in the polymerization container in advance, and then the raw material monomer and the radical polymerization initiator may be supplied to the polymerization container for polymerization.

The component (A) obtained by polymerizing the above components has a glass transition temperature of 30 ° C. or higher, preferably 60 ° C.
It is preferably 180 ° C. or lower, more preferably 90 ° C. or higher, most preferably 100 ° C. or higher and 150 ° C. or lower. When the glass transition temperature is lower than 30 ° C, the hard segment portion of the resin is reduced and the impact resilience is deteriorated. The component A of the present invention can also be preferably used as an acrylic block polymer having two or more block structures of a hard component and a soft component. In this case also, the glass transition temperature has the same preferable glass transition temperature range as described above. Specifically, Tg of the block structure part derived from the soft component
It is preferable to use a block polymer having a temperature of 30 ° C. or higher in order to keep the balance between impact resilience and other physical properties.
In this case, even in the hard segment, preferably T
g is 30 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 90 ° C. or higher. The upper limit of Tg is 150 ° C
Is. The number average molecular weight of the component (A) is 1,000 to
In the range of 150,000, preferably 2,000 to 50,
000, and more preferably 10,000 to 30,000. When the number average molecular weight is less than 1,000, the water-soluble and alkali-soluble parts of the resin are reduced and the water developability is decreased, and the hard segment part of the resin is also decreased, resulting in poor impact resilience. When the number average molecular weight exceeds 150,000, the hard segment portion of the polymer becomes too large,
The impact resilience will be inferior.

The component (B) used in the present invention is not particularly limited as long as it is an isocyanate compound. Specific examples thereof include dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate and hepta. Methylene diisocyanate, 2,2
-Dimethylpentane-1,5-diisocyanate, octamethylene diisocyanate, 2,5-dimethylhexane-1,6-diisocyanate, 2,2,4-trimethylpentane-1,5-diisocyanate, nonamethylenediisocyanate, 2,2,2 4-trimethylhexane diisocyanate, decamethylene diisocyanate, isophorone diisocyanate, 1,4-phenylene diisocyanate, 4,4-diisocyanate-3,3-dimethylphenyl, diphenyldimethane-4,4'-diisocyanate, tolylene diisocyanate, 4, 4'-diphenylmethane diisocyanate, naphthalene-1,5-
Examples thereof include aliphatic, alicyclic or aromatic diisocyanate compounds such as diisocyanate, oligomers and polymers thereof, and these may be used alone or in combination of two or more kinds. Among them, hexamethylene diisocyanate is preferable because it has flexibility, impact resilience, and photocurability excellent in printing durability.

The component (C) used in the present invention is not particularly limited as long as it is a compound having two hydroxyl groups in one molecule, but it is preferable to have a hydrophilic group because the water developability is improved. Specific examples of the component (C) include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1.3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-heptanediol. , 1,6-hexanediol, trimethylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 3-methyl- 1,5-
Aliphatic diols such as pentanediol and 1,8-octanediol; cyclohexane-1,4-diol,
Alicyclic diols such as 1,4-cyclohexane glycol and hydrogenated bisphenol A; xylylene glycol,
Aromatic diols such as 1,4-dihydroxyethylbenzene and an ethylene oxide adduct of bisphenol A; diols containing a sulfur atom such as dithiodiethanol and thiodiethylene glycol; oligomers and polymers thereof. Specific examples of the oligomer and polymer include polyethylene glycol, polypropylene glycol, block polymers of polyethylene glycol and polypropylene glycol, polyether diols such as polybutylene glycol; Mitsubishi Chemical's polytail and Kuraray's both ends. Polyolefin diols such as hydroxyl group-containing hydrogenated polyisoprene and Epol manufactured by Idemitsu Petroleum; B. F. Goodrich OH
Polybutadiene diol such as group-terminated HTBN; polyester diol such as Kuraray manufactured by Kuraray; polycarbonate diol; polyurethane diol; polyorganosiloxane diol; JP-A-5-26280
Examples thereof include polyacrylic diols such as acrylic polymers having hydroxyl groups at both ends described in JP-A-8. Among them, polyether diols are preferable because they are excellent in flexibility and resilience. The component (C) may be used alone or in combination of two or more kinds.

The component (D) used in the present invention is 1
It is not particularly limited as long as it is a photopolymerizable unsaturated monomer having one hydroxyl group in the molecule, and specifically, 2-hydroxyethyl (meth) acrylate, 2-methacrylate (meth) acrylate
Hydroxypropyl, 3-hydroxypropyl (meth) acrylate, methyl 2-hydroxymethyl acrylate,
4-hydroxybutyl (meth) acrylate, mono (meth) acrylic acid ester of polyethylene glycol, mono (meth) acrylic acid ester of polypropylene glycol, polycaprolactone modified product of 2-hydroxyethyl (meth) acrylate (Daicel Chemical Industries (Trade name, "Plaxel F series" manufactured by Co., Ltd.), and hydroxyl group-containing addition polymerizable monomers such as (meth) allyl alcohol 4-hydroxymethylstyrene. Specifically, the hydroxyl group-containing unsaturated acrylic acid ester-based monomer is preferably used. The component (D) may be used alone or in combination of two or more kinds, and among them, 2-hydroxyethyl acrylate is preferable because of its excellent sensitivity. By using the photopolymerizable unsaturated monomer having one hydroxyl group in one molecule in this manner, the urethane resin of the present invention has a structural portion formed by the reaction of the components (B) and (C). A photopolymerizable double bond is introduced into. That is, the component (D) reacts with the structural portion formed by at least the component (B) and the component (C), and a photopolymerizable double bond is introduced into the structural portion to obtain a good urethane resin. .

The urethane resin of the present invention comprises the above (A) to
A resin having a structural unit obtained from each component of (D), preferably a product obtained by reacting a component (B) with a component (C) is reacted with (D), and then (A). A urethane resin obtained by reacting the components is preferable. By using this urethane resin, a photosensitive resin composition having excellent ink resistance and printing resistance can be obtained. The blending ratio of the component (B) and the component (C) is 1.1 to 10 as an equivalent ratio of the NCO group of the component (B) and the hydroxyl group of the component (C) (NCO group / hydroxyl group).
0, preferably 1.1 to 5.0, more preferably 1.2.
A range of up to 2.5 is preferred. The glass transition temperature of the compound obtained by the above reaction is 0 ° C. or lower, preferably −30 ° C. or lower, more preferably −50 ° C., and the compound is water-soluble or hydrophilic. Although a catalyst may be used in the above reaction, the catalyst includes di-n-butyltin dilaurate, stannas octoate, triethylenediamine, diethylenediamine, triethylamine, naphthenic acid metal salt, octylate metal salt such as lead octylate. And so on. Further, a solvent may be used, and examples of the solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; halogenated carbonization such as chlorobenzene, trichlene, and perkrene. Hydrogens; ethers such as tetrahydrofuran and dioxane; esters such as cellosolve acetate, ethyl acetate and butyl acetate.

The blending ratio of the component (D) to the product ((B) + (C)) is 0.25 to 1.95 mol of the component (D) per mol of the product [(B) + (C)]. The range is good. Further, the product of [(B) + (C) + (D)] is (A)
A range of 30 to 250 parts by weight of [(B) + (C) + (D)] product is preferable for 100 parts by weight of the component. The obtained urethane resin is 40 to 9 in the photosensitive resin composition of the present invention.
It can be blended in the range of 9.9% by weight.

The photosensitive resin composition of the present invention further contains a photopolymerization initiator. As the photopolymerization initiator, specifically, 1-hydroxycyclohexyl phenyl ketone,
2,2-dimethoxy-1,2-diphenylethane-1-
On, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1 -One, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,4,6-
Trimethylbenzoyldiphenylphosphine oxide,
1- [4- (2-hydroxyethoxy) phenyl] -2
-Hydroxy-2-methyl-1-propan-1-one,
2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 3,3-dimethyl-4-methoxybenzophenone, benzophenone, 1-chloro-4-propoxythioxanthone, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4-benzoyl-4′-methyldimethylsulfide, 4-dimethylaminobenzoic acid, 4-dimethyl Methyl aminobenzoate, ethyl 4-dimethylaminobenzoate,
Butyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2-isoamyl 4-dimethylaminobenzoate, 2,2-diethoxyacetophenone, benzyldimethylketal, benzyl-β-
Methoxyethyl acetal, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, methyl o-benzoylbenzoate, bis (4-dimethylaminophenyl) ketone, 4,4'-bisdiethylaminobenzophenone , 4,4′-dichlorobenzophenone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, p-dimethylaminoacetophenone, p-tert-butyltrichloroacetophenone, p -Tert-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, dibenzosuberone, α, α-dichloro-4-phenoxy Acetophenone, pentyl -4
Mention may be made of dimethylaminobenzoate and the like. The photopolymerization initiators may be used alone or in combination of two or more. The photopolymerization initiator is used in a commonly used range, but is usually used in a range of 0.1 to 10% by weight based on the photosensitive resin composition.

The photosensitive resin composition of the present invention preferably contains a photopolymerizable unsaturated monomer in order to prevent film loss and swelling during development. Examples of the photopolymerizable unsaturated monomer include acrylic acid and salts thereof; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Isopropyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth)
2-ethylhexyl acrylate, (meth) acrylic acid n
-(Meth) acrylic acid alkyl esters such as octyl, dodecyl (meth) acrylate, stearyl (meth) acrylate; aryl (meth) acrylates such as benzyl (meth) acrylate; glycidyl (meth) acrylate , (Meth) acrylic acid 2-aminoester and other (meth) acrylic acid substituent-containing alkyl esters; methoxyethyl (meth) acrylate, and (meth) acrylic acid derivatives such as ethylene oxide adducts of (meth) acrylic acid Kinds; perfluoromethyl (meth) acrylate, perfluoroethyl (meth) acrylate, (meth)
Perfluoropropyl acrylate, perfluorobutyl (meth) acrylate, perfluorooctyl (meth) acrylate, 2-perfluoromethylmethyl (meth) acrylate, 2-perfluoromethyl (meth) acrylate
2-perfluoroethylmethyl, triphafluoromethylmethyl (meth) acrylate, (meth) acrylic acid 2-
Trifluoromethylethyl, dimethafluoromethylmethyl (meth) acrylate, 2-perfluoroethylethyl (meth) acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth) acrylate, (meth)
2-perfluoromethyl-2-perfluoroethylethyl acrylate, 2-perfluoroethyl-2-perfluorobutylethyl ((meth) acrylate, 2-perfluorohexylethyl (meth) acrylate, (meth) acryl Acid-containing (meth) acrylic acid esters such as 2-perfluorodecylethyl acid and 2-perfluorohexadecylethyl (meth) acrylate; silicon-containing (meth) acryl such as γ- (methacryloyloxypropyl) trimethoxysilane Acid ester monomers; maleic anhydride, maleic acid, maleic acid salts, monoalkyl and dialkyl esters of maleic acid; fumaric acid, monoalkyl and dialkyl esters of fumaric acid; styrene, itaconic acid, itaconic acid Monoalkyl ester and Alkyl ester; 2-hydroxyethyl (meth) acrylate, (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl, 2-hydroxymethyl acrylate methyl,
(Meth) acrylic acid tetramethylene glycol, mono (meth) acrylic acid ester of polyethylene glycol,
Polypropylene glycol mono (meth) acrylic acid ester, 2-hydroxyethyl (meth) acrylate modified with polycaprolactone (manufactured by Daicel Chemical Industries, Ltd.,
Product name "Plaxel F series") and other hydroxyl group-containing addition-polymerizable monomers; styrene, α-methylstyrene, o-
Aromatic vinyl monomers such as methylstyrene, m-methylstyrene, p-methylstyrene, chlorostyrene, styrene sulfonic acid and sodium salt thereof; maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, octylmaleimide. , Dodecyl maleimide, stearyl maleimide, phenyl maleimide, cyclohexyl maleimide and other maleimide derivatives; acrylonitrile, methacrylonitrile and other nitrile group-containing vinyl monomers; acrylamide,
Methacrylamide, methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide, 1,6-hexamethylenebis (meth) acrylamide, diethylenetriaminetris (meth) acrylamide, N- (hydroxymethyl) (meth) acrylamide, N, N ' Amide group-containing vinyl monomers such as bis (β-hydroxyethyl) (meth) acrylamide; phenoxy polyethylene glycol (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, Triethylene glycol di (meth) acrylate, diallyl itaconic acid, glycerol di (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate,
Pentaerythritol tri (meth) acrylate, Glycerol polypropylene glycol tri (meth) acrylate, 1,3-Propylene glycol di (meth) acrylic acid, 1,4-Cyclohexanediol di (meth) acrylic acid, Tri (meth) acrylic Acids 1,2,4-butanetriol, glycerol polypropylene glycol tri (meth) acrylate, 1,4-benzenediol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, di (meth) acrylic tetramethylene glycol 1,5-pentanediol di (meth) acrylic acid, 1,6-hexanediol di (meth) acrylic acid,
Examples thereof include divinyl adipate, divinyl phthalate, acrylated or methacrylated urethane, and the like. The photopolymerizable unsaturated monomer may be used alone or in combination of two or more kinds. Of these, water-soluble monomers and crosslinkable monomers are preferable. Examples of the water-soluble monomer include (meth) acrylic acid and salts thereof, mono (meth) acrylic acid ester of polyethylene glycol,
Examples thereof include methyl 2-hydroxymethyl acrylate, ethyl 2-hydroxymethyl acrylate, butyl 2-hydroxymethyl acrylate, maleic acid and salts thereof. Further, the crosslinkable monomer is not particularly limited as long as it is a monomer having two or more double bonds in one molecule. The photopolymerizable unsaturated monomer may be blended in the range of 0 to 50% by weight with respect to the photosensitive resin composition.

Further, the photosensitive resin composition of the present invention and, if necessary, a dye, a pigment, a polymerization inhibitor, an antioxidant, a photodeterioration inhibitor, etc. may be added to improve the performance thereof.

The photosensitive resin composition of the present invention is further dissolved in an organic solvent according to a known method by adding various additive components used as desired, and after being directly formed into a film or plate, the solvent is removed. Or, after mixing the photosensitive resin composition of the present invention with a roll mixer, it is used in a method of forming a photosensitive resin layer for flexographic relief production by molding into a film or plate shape by hot pressing. It In order to prevent desensitizing action and adhesion due to oxygen in the atmosphere on the surface of the photosensitive resin layer for flexographic relief production,
Water-soluble or alcohol consisting of polyvinyl alcohol, cellulose derivative, polyamides or polyimides
It is preferable to apply a soluble resin in a thickness of 1 to 50 μm to form a film.

The photosensitive resin layer obtained as described above is pressure-bonded to a resin film or sheet of polyethylene terephthalate (hereinafter referred to as PET), polyethylene, polypropylene or the like, a metal plate of iron, aluminum, copper or the like, if necessary. After pre-exposure according to the above, image exposure is performed by selectively irradiating with actinic light through a negative mask, and the unexposed area is washed out with a developer and dried to form a relief plate for flexographic printing with rubber elasticity. Manufactured. For the image exposure, a light source such as an ultra-high pressure mercury lamp or a chemical lamp is used.
The irradiation is performed for about 20 minutes. After the exposure, a developing treatment is carried out. As a developing solution to be used, hydroxides, carbonates, bicarbonates, phosphates, pyrophosphates, benzylamine and butylamine of water, alkali metals such as lithium, sodium and potassium are used. Such as primary amines, dimethylamine, dibenzylamine, diethanolamine and other secondary amines, trimethylamine, triethylamine, triethanolamine and other tertiary amines, morpholine, piperazine, pyridine and other cyclic amines, ethylenediamine, hexamethylene Polyamines such as diamines, tetraethylammonium hydroxide, trimethylbenzylammonium hydroxide, ammonium hydroxides such as trimethylphenylbenzylammonium hydroxide, trimethylsulfonium hydroxide, diethyl Methyl sulfonium hydroxide, sulfonium hydroxide such as dimethyl benzyl sulfonium hydroxide, dilute aqueous solutions of such other choline. The unexposed portion is removed by the developing treatment, and only the exposed pattern remains. As a developing method using a developing solution, a conventional method such as brush developing or spray developing is used.

The photosensitive resin layer of the resin plate for flexographic printing using the photosensitive resin composition of the present invention has excellent water developability and excellent impact resilience. The sensitivity of the resin layer is that light in the wavelength range of 300 to 400 nm is 20
When irradiated at 00 mJ / cm2, the sensitivity indicated by the number of curing stages of a Kodak 21-step tablet is preferably 9 or more. Preferably 11 or more, more preferably 13 or more,
Most preferably, it is 14 or more. Further, the impact resilience measured by a JIS impact resilience tester, which the resin layers of the flexographic printing resin plate should preferably have, is preferably 30% or more, more preferably 32% or more, further preferably 34% or more, and further more preferably 40% or more. % Or more, and most preferably 45% or more.

[0027]

EXAMPLES The present invention will be specifically described below based on Examples and Comparative Examples, but the present invention is not limited thereto.
The number average molecular weights in Examples and Comparative Examples are values obtained from a calibration curve using standard polystyrene using gel permeation chromatography (GPC).

Production Example 1 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
Part by weight was charged, the temperature was raised to 75 ° C., and 2.5 parts by weight of a 20 wt% methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected while blowing nitrogen gas therein. Next, a previously prepared monomer mixture consisting of 5.1 parts by weight of acrylic acid, 54.8 parts by weight of methyl methacrylate, and 40.1 parts by weight of ethyl acrylate was added dropwise over 2 hours. The temperature inside the kettle during the dropping was maintained at the reflux temperature of methyl ethyl ketone. After maintaining the same temperature for 2 hours after the completion of dropping, 5 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected and the reaction was terminated by stirring for 2 hours. After cooling, an acrylic polymer (polymer A) having a number average molecular weight of 49,000, an acid value of 39 mgKOH / g and a glass transition temperature of 38 ° C. was obtained.

Production Example 2 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
A weight part was charged, the temperature was raised to 75 ° C., and 6.25 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected while blowing nitrogen gas. Then prepared acrylic acid 11.5
By weight, a monomer mixture consisting of 62.4 parts by weight of methyl methacrylate and 26.1 parts by weight of ethyl acrylate was added dropwise over 2 hours. The temperature inside the kettle during the dropping was maintained at the reflux temperature of methyl ethyl ketone. After maintaining the same temperature for 2 hours after the completion of the dropping, 20 of azobis-2-methylbutyronitrile was used.
5 parts by weight of a wt% methyl ethyl ketone solution was injected and stirred for 2 hours to complete the reaction. After cooling, an acrylic polymer (polymer B) having a number average molecular weight of 18,000, an acid value of 90 mgKOH / g and a glass transition temperature of 63 ° C. was obtained.

Production Example 3 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
1 part by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected while blowing nitrogen gas into the mixture. Next, a previously prepared monomer mixture consisting of 13.5 parts by weight of acrylic acid, 83.8 parts by weight of methyl methacrylate and 2.7 parts by weight of ethyl acrylate was added dropwise over 2 hours. The temperature inside the kettle during the dropping was maintained at the reflux temperature of methyl ethyl ketone. After maintaining the same temperature for 2 hours after the completion of dropping, 20% by weight of azobis-2-methylbutyronitrile
5 parts by weight of a methyl ethyl ketone solution was injected and stirred for 2 hours to complete the reaction. After cooling, the number average molecular weight is 2
An acrylic polymer (polymer C) having an acid value of 5,000, an acid value of 105 mgKOH / g, and a glass transition temperature of 100 ° C. was obtained.

Production Example 4 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
1 part by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected while blowing nitrogen gas into the mixture. Next, a previously prepared monomer mixture consisting of 11.5 parts by weight of acrylic acid, 62.4 parts by weight of methyl methacrylate, and 26.1 parts by weight of ethyl acrylate was added dropwise over 2 hours. The temperature inside the kettle during the dropping was maintained at the reflux temperature of methyl ethyl ketone. After maintaining the same temperature for 2 hours after the completion of dropping, 5 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected and the reaction was terminated by stirring for 2 hours. After cooling, an acrylic polymer (Polymer D) having a number average molecular weight of 120,000, an acid value of 92 mgKOH / g and a glass transition temperature of 61 ° C. was obtained.

Production Example 5 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
Parts by weight, 88.6 parts by weight of methyl methacrylate, and 19.4 parts by weight of acrylic acid were charged, and the temperature was raised to 75 ° C. Then, 50 parts by weight of a solution of pentaerythritol tetrakisthioglycolate 1 part by weight, azobis-2-methylbutyronitrile 0.3 part by weight, methyl ethyl ketone 6 parts by weight, which is a previously prepared initiator solution, was injected, The reaction started. The temperature inside the kettle during the reaction was kept at the reflux temperature of methyl ethyl ketone. After 50 minutes and 70 minutes after the start of the reaction, 25% by weight of the initiator solution was added, and when the conversion of the monomer was confirmed to be 70% or more, 62.6 parts by weight of ethyl methacrylate and acrylic acid of 9. 4 parts by weight and 66 parts by weight of methyl ethyl ketone were added dropwise over 2 hours. After maintaining the same temperature for 2 hours after the completion of dropping, azobis-2-
0.2 parts by weight of methyl butyronitrile was added and stirring was continued for 2 hours. Then, it is cooled and the number average molecular weight is 20,000.
0, acid value 125 mgKOH / g, glass transition temperature of hard component is 95 ° C, glass transition temperature of soft component is 30 ° C
Thus, an acrylic polymer (polymer E) having a hard component / soft component = 6/4 was obtained.

Comparative Production Example 1 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
A weight part was charged, the temperature was raised to 75 ° C., and 6.25 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected while blowing nitrogen gas. Next, a previously prepared monomer mixture consisting of 5.1 parts by weight of acrylic acid, 38.9 parts by weight of methyl methacrylate and 56 parts by weight of ethyl acrylate was added dropwise over 2 hours. The temperature inside the kettle during the dropping was maintained at the reflux temperature of methyl ethyl ketone. After maintaining the same temperature for 2 hours after the completion of dropping, 20% by weight of azobis-2-methylbutyronitrile
5 parts by weight of a methyl ethyl ketone solution was injected and stirred for 2 hours to complete the reaction. After cooling, the number average molecular weight is 2
An acrylic polymer (polymer F) having an acid value of 30,000, an acid value of 39 mgKOH / g and a glass transition temperature of 18 ° C. was obtained.

Comparative Production Example 2 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
A weight part was charged, the temperature was raised to 75 ° C., and 6.25 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected while blowing nitrogen gas. Next, a previously prepared monomer mixture consisting of 2.6 parts by weight of acrylic acid, 71.3 parts by weight of methyl methacrylate and 26.1 parts by weight of ethyl acrylate was added dropwise over 2 hours. The temperature inside the kettle during the dropping was maintained at the reflux temperature of methyl ethyl ketone. After maintaining the same temperature for 2 hours after the completion of dropping, 5 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected and the reaction was terminated by stirring for 2 hours. Then, the mixture was cooled to obtain an acrylic polymer (polymer G) having a number average molecular weight of 18,000, an acid value of 19 mgKOH / g and a glass transition temperature of 63 ° C.

Comparative Production Example 3 Methyl ethyl ketone 100 was placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser, a dropping funnel and a nitrogen gas introducing tube.
Then, 60 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected while blowing nitrogen gas into the mixture. Next, a previously prepared monomer mixture consisting of 11.5 parts by weight of acrylic acid, 62.4 parts by weight of methyl methacrylate, and 26.1 parts by weight of ethyl acrylate was added dropwise over 2 hours. The temperature inside the kettle during the dropping was maintained at the reflux temperature of methyl ethyl ketone. After maintaining the same temperature for 2 hours after the completion of dropping, 5 parts by weight of a 20% by weight methyl ethyl ketone solution of azobis-2-methylbutyronitrile was injected and the reaction was terminated by stirring for 2 hours. After cooling, the number average molecular weight is 800, the acid value is 90 mgKOH / g, the glass transition temperature is 17
An acrylic polymer (polymer H) having a temperature of 0 ° C. was obtained.

Synthesis Example 1 120 parts by weight of methyl ethyl ketone and Pluronic L61 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) which is an ethylene oxide propylene oxide copolymer are placed in a four-necked flask equipped with a stirrer, an air inlet tube, a thermometer and a reflux condenser. 10
0 part by weight and 20 parts by weight of Niprolan 980 (trade name, manufactured by Nippon Urethane Industry Co., Ltd.), which is a polycarbonate diol, were charged, the temperature was raised to 60 ° C., and the mixture was stirred and dissolved. Then 4
After cooling to 0 ° C, 14.1 parts by weight of hexamethylene diisocyanate and dilauric acid di-
0.05 parts by weight of n-butyltin was added, and the mixture was stirred for 30 minutes, heated to 75 ° C., and stirred for 2.5 hours to carry out a reaction. Then, 7.1 parts by weight of 2-hydroxyethyl acrylate and 0.05 parts by weight of methylhydroquinone were added, and 2
The reaction was carried out by stirring for a time and then cooled to 40 ° C. to obtain a polymer A.

Synthesis Example 2 100 parts by weight of methyl ethyl ketone and Pluronic L61 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), which is an ethylene oxide propylene oxide copolymer, were placed in a four-necked flask equipped with a stirrer, an air inlet tube, a thermometer and a reflux condenser. 60
Parts by weight, Nipporan 9 which is a polycarbonate diol
15 parts by weight of 80 (trade name, manufactured by Nippon Urethane Industry Co., Ltd.) and 25 parts by weight of P-2010 (trade name, manufactured by Kuraray Co., Ltd.), which is a polyester polyol, were mixed and stirred at 40 ° C. for 30 minutes. Next, while blowing in air, 13.4 parts by weight of hexamethylene diisocyanate and dilauric acid di-
0.05 parts by weight of n-butyltin was added, and the mixture was stirred for 30 minutes, heated to 75 ° C., and stirred for 2.5 hours to carry out a reaction. Next, 3.6 parts by weight of hexamethylene diisocyanate, 7.1 parts by weight of 2-hydroxyethyl acrylate,
Polymer B was added by adding 0.05 parts by weight of methylhydroquinone, stirring for 2 hours to carry out a reaction, and then cooling to 40 ° C.
Got

Synthesis Example 3 In Synthesis Example 1, hexamethylene diisocyanate 1 was used.
Polymer C was obtained by performing the same reaction as in Synthesis Example 1 except that 21 parts by weight of methylene-bis- (4-phenylisocyanate) was used instead of 4.1 parts by weight.

Comparative Synthesis Example 1 In Synthesis Example 1, hexamethylene diisocyanate 1 was used.
Using 0.1 part by weight, the reaction was carried out by stirring for 2.5 hours, and then 2-hydroxyethyl acrylate was not added.
It cooled to 0 degreeC and obtained the polymer D.

Comparative Synthesis Example 2 In a four-necked flask equipped with a stirrer, an air introduction tube, a thermometer and a reflux condenser, 50 parts by weight of methyl ethyl ketone, 14.2 parts by weight of hexamethylene diisocyanate, and 2-hydroxyethyl acrylate. 15.6 parts by weight, di-n-butyltin dilaurate 0.02 parts by weight, and methylhydroquinone 0.03 parts by weight were added, stirred for 30 minutes, heated to 75 ° C., and stirred for 2.5 hours to react. After performing,
To obtain Polymer E.

Example 1 The polymer A8 obtained in Synthesis Example 1 was placed in a 4-necked flask equipped with a stirrer, an air introduction tube, a thermometer and a reflux condenser.
5.7 parts by weight and 200 parts by weight of the polymer A obtained in Production Example 1 were charged and stirred and mixed at 40 ° C. for 30 minutes while blowing air, then heated to 75 ° C. and stirred for 3 hours to carry out the reaction. It was After the reaction, IR which is urethane acrylate
R213 (trade name, manufactured by Daicel UCB) 20
Parts by weight, 2,2-dimethoxy-1,2-diphenylethan-1-one 2 parts by weight and methylhydroquinone 0.05
A photosensitive resin solution was obtained by adding parts by weight and stirring and mixing. Then, this solution was desolvated under reduced pressure with a twin-screw extruder,
PET film extruded to a thickness of 1.6 mm and provided with an adhesive layer, and PE coated with polyvinyl alcohol
A photosensitive resin plate was obtained by laminating with a T film.

The above photosensitive resin plate was replaced with a chemical lamp FL.
Using a -40BL (Chemical Lamp, manufactured by Toshiba Corporation), an actinic ray that hardens by 0.6 mm is irradiated from the PET film side provided with the adhesive layer, then the PET film on the opposite side is peeled off, and the negative film is vacuum-bonded. Exposure was carried out by irradiation for 10 minutes. After exposure, development was performed at 30 ° C. using a 2.38 wt% tetramethylammonium hydroxide aqueous solution, followed by drying at 60 ° C. for 15 minutes, and further post-exposure using a chemical lamp for 5 minutes for flexographic printing. The resin plate for use was obtained, and the plate making characteristics and the physical properties after curing were examined. Further, the obtained plate-making product was printed on hard paper as a resin plate for flexographic printing (water-based ink used: DF-040 red, DF-2
Both 60 black and DF-140 ultramarine blue were manufactured by Sakata Ink Co., Ltd., and the ink resistance and printing resistance were examined. The evaluation results are shown in Table 1.

Example 2 In Example 1, the polymer A17 obtained in Synthesis Example 1 was used.
1.4 parts by weight and the polymer B211.
A resin plate for flexographic printing was prepared using the photosensitive resin plate obtained by the same operation as in Example 1 except that 4 parts by weight was used, and the evaluation results thereof are shown in Table 1.

Example 3 In Example 1, the polymer A25 obtained in Synthesis Example 1 was used.
7.1 parts by weight and the polymer C206.
A resin plate for flexographic printing obtained by using the photosensitive resin plate obtained by the same operation as in Example 1 except that 2 parts by weight was used, and the evaluation results thereof are shown in Table 1.

Example 4 Polymer B21 obtained in Synthesis Example 2 in Example 1
0.7 parts by weight and the polymer C206.
A resin plate for flexographic printing obtained by using the photosensitive resin plate obtained by the same operation as in Example 1 except that 2 parts by weight was used, and the evaluation results thereof are shown in Table 1.

Example 5 In Example 1, the polymer C26 obtained in Synthesis Example 3 was used.
A resin plate for flexographic printing obtained by using the photosensitive resin plate obtained by the same operation as in Example 1 except that 4 parts by weight and 206.2 parts by weight of the polymer C obtained in Production Example 3 were used. It was produced, and the evaluation results thereof are shown in Table 1.

Example 6 In Example 1, the polymer A17 obtained in Synthesis Example 1 was used.
1.4 parts by weight and the polymer D206.
A resin plate for flexographic printing obtained by using the photosensitive resin plate obtained by the same operation as in Example 1 except that 2 parts by weight was used, and the evaluation results thereof are shown in Table 1.

Example 7 In Example 1, the polymer A25 obtained in Synthesis Example 1 was used.
7.1 parts by weight and the polymer E193.
A resin plate for flexographic printing obtained by using the photosensitive resin plate obtained by the same operation as in Example 1 except that 4 parts by weight was used, and the evaluation results thereof are shown in Table 1.

Comparative Example 1 A photosensitive material obtained by the same procedure as in Example 1 except that 211.4 parts by weight of the polymer F obtained in Comparative Production Example 1 was used in place of the polymer A in Example 1. A resin plate for flexographic printing obtained by using a flexible resin plate was prepared, and the evaluation results thereof are shown in Table 1.

Comparative Example 2 A photosensitive material obtained by the same procedure as in Example 1 except that 211.4 parts by weight of the polymer G obtained in Comparative Production Example 2 was used in place of the polymer A in Example 1. A resin plate for flexographic printing obtained by using a flexible resin plate was prepared, and the evaluation results thereof are shown in Table 1.

Comparative Example 3 A photosensitive material obtained in the same manner as in Example 1 except that 259.7 parts by weight of the polymer H obtained in Comparative Production Example 3 was used in place of the polymer A in Example 1. A resin plate for flexographic printing obtained by using a flexible resin plate was prepared, and the evaluation results thereof are shown in Table 1.

Comparative Example 4 In Example 1, the polymer D obtained in Comparative Synthesis Example 1 was used.
250.1 parts by weight and the polymer C2 obtained in Production Example 3
A resin plate for flexographic printing obtained by using the photosensitive resin plate obtained by the same operation as in Example 1 except that 06.2 parts by weight was used, and the evaluation results thereof are shown in Table 1. .

Comparative Example 5 Polymer E obtained in Comparative Synthesis Example 2 in Example 1
79.9 parts by weight and polymer C20 obtained in Production Example 3
Example 1 was used except that 6.2 parts by weight was used and 50 parts by weight of IRR213 (trade name, manufactured by Daicel UCB), which is a urethane acrylate to be charged after the reaction, was replaced with 50 parts by weight.
A resin plate for flexographic printing obtained by using the photosensitive resin plate obtained by the same operation as in 1. was prepared, and the evaluation results thereof are shown in Table 1.

Comparative Example 6 To the photosensitive resin solution obtained in Comparative Example 4, 7.1 parts by weight of 2-hydroxyethyl acrylate was further added, and the mixture was used in the same manner as in Example 1 for flexographic printing resin. A plate was made. The evaluation results are shown in Table 1. The produced flexographic printing resin plate did not have sufficient performance because 2-hydroxyethyl acrylate did not react.

[0055]

[Table 1] In the table, the sensitivity is indicated by the number of curing steps of a 21-step tablet manufactured by Kodak Co., Ltd., and the impact resilience is measured by using a JIS impact resilience tester (Kamijima Seisakusho)
The ink resistance is represented by the number of printed copies in which a printing failure due to expansion occurs, and ◎ indicates 500,000 or more, ○
Is 100,000 to less than 500,000, △ is 50,000 to less than 100,000, ×
Is less than 50,000, and the printing resistance is represented by the number of prints in which a print failure occurs due to abrasion and abrasion, ◎ is 500,000 or more, ◯ is 200,000 to less than 500,000, △ is 50,000 to less than 200,000, × Is less than 50,000. Further, in the comprehensive evaluation, ⊚ is evaluated as being particularly practical, ◯ is practical, Δ is usable but practically problematic, and x is practically unusable.

As is clear from Table 1 above, the photosensitive resin composition of the present invention has high sensitivity, high impact resilience, and excellent ink resistance and printing durability. In particular, when hexamethylene diisocyanate is used as a compound having two isocyanate groups in one molecule, Examples 1 to 4, 6,
As shown in 7, the impact resilience is high, and by using a polyether diol as a compound having two hydroxyl groups in one molecule, flexibility and impact resilience are increased. Further, it can be seen that the sensitivity is improved by using 2-hydroxyethyl acrylate as the photopolymerizable unsaturated monomer having one hydroxyl group in one molecule.

[0057]

The photosensitive resin composition of the present invention can be easily developed with water or a dilute alkaline aqueous solution and has high sensitivity.
The printing plate material thus produced has high impact resilience, excellent ink resistance and printing durability, and is excellent as a thick printing plate material such as cardboard.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI // C08G 18/67 C08G 18/67 (72) Inventor Koji Kahara 5-8 Nishimitabicho Suita City Osaka Prefecture Stock Company In Japan Catalyst (72) Inventor Nobuhiro Kobayashi 5-8 Nishimitabicho Suita City, Osaka Prefecture Stock Company Japan Catalyst (72) Inventor Masatoshi Yoshida 5-8 Nishimitabi Town Suita City, Osaka Prefecture Japan In a catalyst (56) Reference JP-A-8-54734 (JP, A) JP-A-9-265187 (JP, A) JP-A-8-36263 (JP, A) JP-A-8-292570 (JP, A) ) JP-A-9-5992 (JP, A) JP-A-6-345835 (JP, A) JP-A-5-27435 (JP, A) JP-A-7-278492 (JP, A) JP-A-50- 6403 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (11)

(57) [Claims] 1. A polymer having a carboxyl group having an acid value of 30 mgKOH / g or more and a glass transition temperature of 30 ° C. or more, (B) a compound having two isocyanate groups in one molecule, and (C). A urethane resin obtained by reacting a compound having two hydroxyl groups in one molecule and (D) a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule, and a photopolymerization initiator are contained. A characteristic photosensitive resin composition. 2. A polymer having a carboxyl group having an acid value of 30 mgKOH / g or more and a glass transition temperature of 30 ° C. or more, (B) a compound having two isocyanate groups in one molecule, and (C). Urethane resin obtained by reacting a compound having two hydroxyl groups in one molecule and (D) a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule, and a photopolymerizable unsaturated monomer, A photosensitive resin composition comprising a photopolymerization initiator. 3. A polymer having a carboxyl group having an acid value of 30 mgKOH / g or more and a glass transition temperature of 30 ° C. or more, (B) a compound having two isocyanate groups in one molecule, and (C). Containing a compound having two hydroxyl groups in one molecule and (D) a urethane resin having a structural unit composed of each component of a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule, and a photopolymerization initiator A photosensitive resin composition comprising: 4. A urethane resin is a component (B), a component (C),
The photosensitive resin composition according to any one of claims 1 to 3, which is a resin obtained by reacting the component (D) and the component (A) in this order. 5. The photosensitive resin composition according to any one of claims 1 to 4, wherein the component (A) is an acrylic polymer. 6. The photosensitive resin composition according to any one of claims 1 to 4, wherein the component (B) is hexamethylene diisocyanate. 7. The photosensitive resin composition according to any one of claims 1 to 5, wherein the component (C) is a polyether diol. 8. The component (D) is a hydroxyl group-containing unsaturated acrylate monomer.
5. The photosensitive resin composition according to any one of items 4 to 4. 9. The photosensitive resin composition according to claim 8, wherein the unsaturated acrylic acid ester-based monomer having a hydroxyl group is 2-hydroxyethyl acrylate. 10. A resin plate for flexographic printing, which comprises the photosensitive resin composition according to any one of claims 1 to 9. 11. A photosensitive resin layer according to JIS K6301-11.
The resin plate for flexographic printing according to claim 10, which has a rebound resilience of 30% or more.