JPS62231245A - Photosensitive flexo plate - Google Patents

Abstract

PURPOSE:To improve definition by adding a fluorane compd. and/or a fluorene compd. CONSTITUTION:A fluorane compd. and/or a fluorene compd. are (is) added to a photosensitive polymer compsn. consisting of a high molecular polymer, ethylenic unsatd. monomer, and a photopolymn. initiator. Thermoplastic block polymerized rubber such as polyisoprene rubber, polybutadiene rubber, etc., or a rubber-like polymer such as hydrogenated products thereof, etc., is used as the high molecular polymer. Further, resinous polymer or leather like polymer such as copolymers of vinyl chloride with acrylonitrile, methyl methacrylate, vinyl acetate, etc., may be used also. As the ethylenic unsatd. monomer, monomers having higher functionality than two are used generally. These materials are used alone or as a mixture of >= two kinds thereof, and the amt. is usually 5-100pts.wt., pref. 5-20pts.wt. per 100pts.wt. high molecular polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a photosensitive polymer composition using a fluoran compound and/or a fluorene compound as an ultraviolet absorber.

(Prior art) Conventionally, it has been added as a high molecular weight polymer, an ethylenically unsaturated monomer agent, a thermal polymerization addition inhibitor, and an antihalation agent as disclosed in Japanese Patent Publication No. 43373/1983 and Japanese Patent Application Laid-open No. 57-1.
It is publicly known from Japanese Patent No. 57237, Japanese Patent Publication No. 58-62640, etc.

In recent years, with advances in printing technology, flexographic plates are required to have a higher level of printing surface formation precision. It is difficult to satisfy this requirement with the use of conventionally known ultraviolet absorbers, and the printing surface formation rate of 61 degrees (hereinafter referred to as resolution) for negative type (thin white lines on intaglio) is higher than that of positive type (thin lines on letterpress). ) is inferior, and improvements are desired.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide a photosensitive polymer composition with improved resolution, and the present invention uses a fluoran compound and/or a fluorene compound as an ultraviolet absorber. By using it, the resolution of both negative and positive images can be greatly improved, the exposure speed can be easily adjusted, the coloring is bright, and there is little fading or discoloration after exposure and development. Based on these findings, we have completed the present invention.

(Problems? Means for Solving) Thus, according to the present invention, in a photosensitive polymer composition comprising a high molecular weight polymer, an ethylenically unsaturated monomer, and a photopolymerization initiator, a fluoran compound and/or A photosensitive polymer composition characterized by the addition of a fluorene compound is provided.

A high molecular weight polymer constituting the photosensitive polymer composition of the present invention,
Both the ethylenically unsaturated monomer and the photopolymerization initiator can be those conventionally used, and in the present invention, neither is particularly limited. Glen rubber, polybutadiene rubber, 1,2-polybutadiene, styrene-butadiene copolymer rubber, polychlorograne rubber, ethylene-propylene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylonitrile-butadiene-imprene copolymer Rubber, chlorosulfonated polyethylene, butyl rubber, acrylic rubber 1, epichlorohydrin rubber, fluororubber, urethane rubber, polysterene-polyingrene-borysterene disclosed in Japanese Patent Publication No. 51-45574, polysterene-polybutadiene-boristyrene, etc. Rubbery polymers such as thermoplastic block polymer rubbers and hydrides thereof are exemplified.

Also, copolymers of vinyl chloride and acrylonitrile, methyl methacrylate, or vinyl acetate; copolymers of vinyl acetate and ethylene, acrylate, or methyl methacrylate; polyalkyl acrylates such as polymethyl methacrylate; 6-nylon, bellow nylon, Resin-like or leather-like polymers such as polyamides such as 12-nylon may also be mentioned.◎ As the ethylenically unsaturated monomer used in the present invention, those having difunctionality or higher are usually used. For example, Petilji (
meth)acrylate), 1,6-hexidi(meth)acrylate, neobentyl di(meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylol Examples include monomers that form a compatible mixture with the above-mentioned polymers, such as ethanetri(meth)acrylate) and N-N'-methylenebisacrylamide. These can be used alone or in combination
It is used in a mixture of at least 100% of the polymer, and is used in an amount of usually 5 to 100 parts by weight, preferably 5 to 20 parts by weight, based on 100N of the high molecular weight polymer.

Photopolymerization initiators used in the present invention include acyloin, such as benzoin and alkyl ethers of benzoin; biinal diketones, such as benzyl, diacetyl, diphenyl sulfite, eosin, thionin,
Benzophenone, thioxa 7ton derivatives, etc. are usually added in an amount of 0.001 to 10 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of the polymer. Used in quantitative parts.

In the present invention, cresol-based, phenol-based, hydroquinone-based compounds, etc. are used as thermal polymerization inhibitors, if necessary. The amount used is usually in the range of 0.01 to 1 part by weight per 100 parts by weight of the polymer.

The ultraviolet absorber used in the present invention is a fluorane compound and/or a fluorene compound, and this compound has the function of suppressing radiation caused by internal scattering during exposure and improving resolution as a result. As the fluoran compound and fluorene compound used in the present invention, compounds having a fluoran skeleton and a fluorene skeleton, respectively, and having ultraviolet absorption ability are used.

Examples of fluoran compounds include S, 6-N, N-
Diethylaminofluorane, 3-diethylamino-7-
Aminofluorane, 3-N,N-diethylamino-7-
Methylaminofluorane, spiro(xanthine-21-
styrene) -2,6-bis(diethylamino)-3-
on, 3-diethylamino-6-methyl-7-alkyl (108-16) aminofluorane, 3-diethylamino-7-cyclohexylaminofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-
Die"thylamino-6-methyl-7-xylidinofluorane, 3-diethylamino-6-methyl-7-P-puteranilinofluorane, spiro(xanthine-9,1-
Furatane) -5,6-bis(N-methylanilino)-
3-one, 2-anilino-3-methyl-6-(N-ethyl-P-)luidino)fluoran, 2-(N-phenyl-N-methylamino)-6-(N-7)-)dyl- N-
ethyl)amino-fluorane, 3-(N,N-diethylamino)-7-(NtN'-dibenzylaba))fluorane, 3-(N,N-diethylamino)-5-methyl-
7-(N,N'-dibenzylamino)fluorane, 5-
(N,N-diethylamino)-7-bis(dimethylbenzyl)aminofluorane, 5-(11-cyclohexyl-N-methylamino)-6-methyl-7-anilinofluorane, 3-diethylamino-7-N -7 Chlohexyl-N-benzylaminofluorane, 3-diethylamino-7-chloroanilinofluorane, 3-diethylamino-6-methyl-7-p-phenetidinofluorane, 3-
Diethylamino-7-(2-carbomethoxyanilino)
Fluoran, 3-diethylamino-7-chlorofluoran, 3-dinithylamino-6-methyl-7-chlorofluoran, 3-cyclohexylamino-6-chlorofluoran, 3-benzylamino-6-chlorofluoran, 3
．． 6-Sihydroxyspiro[isobenzofuran-1
(5H),? '-[9H]xanthine]-3-one aluminum salt, 5,6-simethoxyfluorane, 2,4
, 5.7-titrabromofluorescene, 2.4.5.7
-Titrapromo 12.13.14.15-Tetrachloro-46-fluorane, aluminum lake of diol, 5,6-cyhydroxy-4,5'-jodosespiro[isopencyflav-1 (3H).

Aluminum salt of 9'-(9H)xanthinetwo-3one, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-pyrrolidino-7-cyclohexylaminofluorane, 3.6-bis(diethylamino)fluorane- r
-Anilinolactam and the like.

Examples of fluorene compounds include 9-(4-dimethylamino-2-carboxyphenyl)-6,6-dimethylaminofluorene, 9-(4-dimethylamino-2-
carboxyphenyl)-3-diethylamino-6-dimethylaminofluorene, 9-(4-dimethylamino-2
-carboxyphenyl)-3-zigbutyramino-6-
Dimethylaminofluorene, 9-(4-diethylamino-2-carboxyphenyl)-3,6-dimethylaminofluorene, 9-(4-dibutylamino-2-carboxyphenyl)-3-dimethylamino-6-dimethylaminofluorene, etc. can be mentioned.

These compounds may be used alone or in combination of two or more, and are usually used in an amount of o, oooi to 0.5 parts by weight per 100 parts by weight of the high molecular weight polymer.

The photosensitive polymer composition of the present invention may have a molecular weight of 1,000 to 5, if necessary, for the purpose of adjusting moldability and hardness.
Liquid polymers, petroleum resins, polyterpene resins, polyester resins, etc. of about 100% are high molecular weight polymers.
3: 60'Mi is added in a range of 1 part or less per i part.

Other additives such as stabilizers (anti-aging agents) and thermal polymerization inhibitors may also be used as appropriate.

The photosensitive polymer composition of the present invention is prepared by mixing the high molecular weight polymer and the above-mentioned components using a mixer such as a kneader or a roll, and usually using a molding machine such as an extruder, press or calendar. It is then molded into a sheet of desired thickness. Alternatively, the composition of the present invention can be mixed with an organic solvent and cast onto a support to form a sheet. These sheets are used as photopolymer master plates for flexographic printing,
Extremely excellent exposure pattern reproducibility and relief edge sharpness can be obtained, and the original plate is extremely brightly colored, and has the characteristics of not fading or discoloring due to ultraviolet irradiation.

The present invention will be explained in more detail below with reference to Examples.

Note that the numbers of parts and amounts in Examples and Comparative Examples are based on weight.

Example 1 Polystyrene-polyisoprene-polystyrene block copolymer (FinTac 3550 manufactured by Nippon Zeon Co., Ltd.) 10
0 parts, liquid polybutadiene (Niraso PB manufactured by Nippon Soda Co., Ltd.
B-1000) 10 parts, 2,6-di-t-butyl-4-
0.3 part of methylphenol (BHT) was added to a twin-screw kneader.
The mixture was kneaded and mixed at a temperature of 130 to 170°C. In the dark, 0.6 parts of benzoin ethyl ether and 0.0017 parts of a fluoran ultraviolet absorber (Elot Pink-1 manufactured by Odugaya Chemical Co., Ltd.) were dissolved in 5 parts of butanediol diacrylate and 4 parts of butanediol dimethacrylate. and uniformly mixed at a temperature of 80 to 120° C. ◇ Similarly, a photosensitive composition was prepared according to the formulation shown in Table 1.

Each of these compositions was degassed under reduced pressure, sandwiched between two polyester sheets, and heated using a 5.2 ml spacer at 120° C. and a pressure of 100 o/cp for 3 to 10 min.
A photosensitive original plate with a thickness of 50 mm was obtained between the Greme Gres ester sheets. Similarly, a photosensitive original plate using a conventional ultraviolet absorber was prepared as a comparative example.

One side of the polyester sheet was peeled off, and a negative film with an exposure pattern for evaluation was adhered to that side. First, use the exposure machine (JK-A5-8EI manufactured by JEOL Seiki Co., Ltd.) from the long side.
The film was irradiated for 3 minutes, and then irradiated for 10 minutes from the negative film side.

After finishing the process, use a brush-type washing machine (liquid temperature: 30°C) containing trical ethane/isoglobil alcohol-10/1.
] A relief image of a dragon with a depth of 14 was formed in a development time of 7 minutes. After performing post-exposure for 5 minutes, the relief image obtained was visually inspected and photographed. 100 μ wide thin line (convex thin line), 100 μ wide white thin line!! (concave thin line), 1 inch long. 150 dots (111
The reproducibility of 4 points (expressed as 100 L/1 nch) and the sharpness of the edge of the surface of the relief image cut perpendicularly to the photosensitive plate were evaluated. Also, 20 levels of 1jk
The reproducibility of light patterns was evaluated using a gray scale and expressed as a number representing the reproducibility level.

The above results are shown in Table 2.

Table 2 The results in Table 2 show that by using a fluoran-based ultraviolet absorber, more than 15 levels of gray scale can be reproduced, and the reproducibility of convex and concave fine lines and the sharpness of edges are also remarkable. It shows that it will be improved. Furthermore, when conventional ultraviolet absorbers were used, the coloring of the photosensitive plate faded or changed due to ultraviolet irradiation, but when fluoran-based ultraviolet absorbers were used, no fading or discoloration was observed.

Example 2 A photosensitive flexographic original plate was prepared in the same manner as in Example 1 except that S-S of Example 1 was used as the polymer and the ultraviolet absorber listed in Table 3 was used, and an exposure test was conducted. . The results are also listed in Table 5.

Claims (1)

[Claims] A photosensitive polymer composition comprising a high molecular weight polymer, an ethylenically unsaturated monomer, and a photopolymerization initiator, characterized in that a fluoran compound and/or a fluorene compound is added thereto. .