JPH0349096B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photosensitive polyester resin composition. Specifically, the present invention relates to a photosensitive polyester resin composition capable of forming a photosensitive layer of a printing plate having excellent photosensitivity, printing durability, and oil sensitivity. A photosensitive polyester resin having a photosensitive ethylenically unsaturated double bond adjacent to an aromatic nucleus in its molecular main chain is known as one of the typical photocrosslinkable photosensitive resins. Such resins include dicarboxylic acids such as phenylene diacrylic acid, carboxycinnamic acid, and chalcone dicarboxylic acid, and ethylene glycol,
propylene glycol, butylene glycol,
It is obtained by condensing polyhydric alcohols such as 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, glycerin, and trimethylolpropane. However, although resins obtained using polyhydric alcohols as described above have high photosensitivity, they have the disadvantage of poor printing durability. In other words, such resins tend to swell in petroleum-based hydrocarbon solvents that are commonly used as printing ink solvents, and are easily abraded by frictional forces. It is difficult to produce good printing plates. By using a glycol with a polyether chain such as tetraethylene glycol or polyethylene glycol as the polyhydric alcohol, a resin with high photosensitivity can be obtained, but on the other hand, such resin has low oil sensitivity. It has inferior disadvantages. Therefore, printing plates obtained using such resins have insufficient ink receptivity (commonly called ink transfer). The present inventors conducted extensive research to improve the printing durability and oil sensitivity of the previously known photosensitive polyester resin without reducing its excellent photosensitivity. The inventors have discovered that the use of alkylene oxide adducts of phenol is extremely effective in achieving the above improvements, and have arrived at the present invention. That is, the present invention provides (a) a unit of a dicarboxylic acid (hereinafter referred to as a photosensitive unsaturated dicarboxylic acid) having a photosensitive ethylenically unsaturated double bond adjacent to an aromatic nucleus in at least a part of the polycarboxylic acid unit; (b) at least a part of the polyhydric alcohol unit has the general formula (1) (In the formula, R ₁ and R ₂ each have 2 to 4 carbon atoms.
represents an alkylene group, R ₃ and R ₄ each represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, l and m each represent an integer of 1 or more, and l + m is an integer of 2 to 20. . ) The present invention relates to a photosensitive polyester resin composition containing a photosensitive polyester resin containing a glycol unit represented by the following as a film-forming main component. Examples of the photosensitive unsaturated dicarboxylic acid unit contained in the photosensitive polyester resin of the present invention include units represented by the following general formulas () to (). These units are derived from their respective corresponding dicarboxylic acids or their dialkyl esters such as dimethyl ester, diethyl ester; di(alkylene glycol) esters such as di(ethylene glycol) ester, di(propylene glycol) ester, etc. can do. In the above general formulas (2) to (8), R ₅ and R' ₅ are hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, and 1 to 4 carbon atoms, respectively.
4 represents an alkoxyl group, halogen atom or nitro group, R ₆ represents an alkylene group having 2 to 4 carbon atoms, n represents an integer of 1 to 4, and p represents an integer of 1 to 5.
represents an integer of 1 to 5, and q represents an integer of 1 to 5. Specific examples of particularly preferred dicarboxylic acid units include p-phenylene diacrylic acid, m-
phenylene diacrylic acid, 2,5-dimethoxy-
p-phenylene diacrylic acid, 2-nitro-p-
Phenylene diacrylic acid, p-carboxycinnamic acid, cinnamylidene malonic acid, bis(p-cinnamic acid) diethylene glycol ether, bis(p-
carboxybenzal)cyclohexanone, bis(p-carboxybenzal)cyclopentanone,
Examples include those derived from dicarboxylic acids such as p,p'-chalcone dicarboxylic acid. The polycarboxylic acid unit of the photosensitive polyester resin of the present invention can contain other polycarboxylic acid units together with the above dicarboxylic acid unit,
Such other polycarboxylic acid units include, for example, succinic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, Polyvalent carboxylic acids or anhydrides such as phthalic acid and 5-sodium sulfoisophthalic acid, or their dialkyl esters such as dimethyl ester and diethyl ester; di(alkylene glycol) such as di(ethylene glycol) ester and dipropylene glycol ester
Examples include those derived from diesters such as esters. A suitable amount of the photosensitive unsaturated dicarboxylic acid units contained in the photosensitive polyester resin of the present invention is 30 to 100 mol% of the total polyhydric carboxylic acid units, and a particularly preferred amount is 55 to 100 mol%. It is. Sufficiently high photosensitivity can be obtained within this range. Suitable examples of the glycol unit represented by the general formula (1) contained in the photosensitive polyester resin of the present invention include an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, and an ethylene oxide adduct of bisphenol F. It is derived from an adduct, a propylene oxide adduct of bisphenol F, and the like. The polyhydric alcohol unit of the photosensitive polyester resin of the present invention can contain other polyhydric alcohol units together with the unit of general formula (1), and examples of such other polyhydric alcohol units include ethylene. Glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 1,3-butylene glycol, 1,6
-hexanediol, 2,2,4-trimethylpentane-1,3-diol, 2-butene-1,4
-diol, 1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanedimethanol, cyclohexane 1,4-diol, hydrogenated bisphenol A, hydrogenated bisphenol F, 3-methylpentane-1,3,5-triol , trimethylolpropane, trimethylolethitane, pentaerythritol, glycerin, diglycerin,
Examples include those derived from dipentaerythritol, sorbitol, and the like. A suitable amount of glycol units of general formula (1) contained in the photosensitive polyester resin of the present invention is 2 to 100 mol% of the total polyhydric alcohol units, and a particularly preferred amount is 10 to 100 mol%. be. Within this range, sufficient printing durability and oil sensitivity can be obtained. The photosensitive polyester resin of the present invention has no particular limitations regarding molecular weight, but one having a weight average molecular weight of 5,000 to 120,000 is suitable. Such photosensitive polyester resins can be prepared by means known in the field of ordinary polyester synthesis, such as "Lecture on Polymerization Reactions 9, Polycondensation" published by Seisho.
Written by Ogata (Published by Kagaku Dojinsha or U.S. Patent No.
It can be easily produced by the method described in Japanese Patent No. 3622320. For example, after the polyhydric carboxylic acid component and the polyhydric alcohol component are reacted in an esterification reaction or transesterification reaction, optionally in the presence of a reaction catalyst and a polymerization inhibitor, the pressure of the reaction system is gradually reduced. It can be produced by distilling off excess polyhydric alcohol and the like. The reaction temperature is preferably 150 to 250°C, and the reduced pressure is preferably 3 mmHg or less at the end of polycondensation. The photosensitive resin composition of the present invention is generally produced by dissolving it in the photosensitive polyester resin solvent described above. Suitable solvents vary depending on the composition and molecular weight of the resin, but are typically methylene chloride,
Chlorinated solvents such as chloroform, trichloroethane, trichloroethylene, chlorobenzene, dichlorobenzene, carbon tetrachloride; Alcohol solvents such as tetrahydrofurfuryl alcohol and benzyl alcohol; Ether solvents such as tetrahydrofuran and dioxane; Glycol monomethyl ether, glycol mono Glycol monoalkyl ether solvents such as ethyl ether; ester solvents such as glycol methyl ether acetate, glycol ethyl ether acetate, and ethyl acetate;
Methyl ethyl ketone, methyl isobutyl ketone,
Cyclohexanone, 4-methyl-4-methoxy-
Examples include ketone solvents such as 2-pentanone; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and nitrobenzene; the above solvents can be used alone or in a mixture of two or more. The photosensitive polyester resin composition of the present invention may contain various components other than the above components, for example, a sensitizer, a pigment, a dye, a filler,
Contains printing durability improvers, lipophilicity improvers, binding aids, etc. As the sensitizer, any one that can be used in this field can be used, including benzophenone derivatives, benzanthrone derivatives, naphthothiazoline derivatives,
Aromatic carbonyl compounds such as quinones, aromatic nitro compounds, pyrylium salts, thiapyrylium salts, etc. can be used. Specific examples of these include Michler's ketone, diethylaminoethylbenzophenone, benzanthrone (3-methyl-1,3-diaza-1,9-benz) anthrone picramide, 2-dibenzoylmethylene-3
-Methylnaphthothiazoline, 2-benzoylmethylene-1-methylnaphthothiazoline, 1,8-dimethoxyanthraquinone, 1,2-benzanthraquinone, 5-nitroacenaphthene, 2-nitrofluorene, 2,7-dinitrofluorene, 1-
Nitronaphthalene, 1,5-dinitronaphthalene, 2,4,6-triphenylthiapyrylium perchlorate, 2,6-bis(p-ethoxyphenyl)-4-(p-n-amyloxyphenyl)- Examples include Chiapyrylium perchlorate. The photosensitive polyester resin composition of the present invention is formulated to have an appropriate viscosity so that it can be applied to commonly used coating techniques such as whirler coating, dip coating, curtain coating, roll coating, spray coating, air knife coating, The coating is applied to the support by a well-known coating method such as doctor knife coating or spinner coating. Specific examples of the support material to be coated include aluminum plates, zinc plates, stainless steel plates, and other metal plates; sheets and plates of synthetic resins such as polyethylene terephthalate, polycarbonate, and cellulose derivatives; There are various materials conventionally used as supports for printing plates, such as paper coated with melt coating or a synthetic resin solution, composite materials in which a metal layer is provided on a synthetic resin by techniques such as vacuum deposition or lamination, and other materials. After coating, the coating solution is dried and solidified by a well-known method to obtain a printing original plate having a photosensitive layer provided on the support. The photosensitive layer of this printing original plate is subjected to imagewise exposure using a negative image to harden and insolubilize the exposed areas of the photosensitive layer, and then it is developed to dissolve and remove the unexposed areas, thereby producing a corresponding image on the support. can be formed. Suitable light sources used for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, lasers, and the like. As described above, the photosensitive polyester resin composition of the present invention is extremely effective for forming a photosensitive layer of a printing plate, but the use of the composition of the present invention is not necessarily limited to the photosensitive layer of a printing plate. For example, it can also be used as a photoresist for various types of microfabrication. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. Examples 1 to 7 (1) Production of photosensitive polyester resin Each mixture having various compositions was charged into a reactor equipped with a stirring device, a nitrogen gas introduction tube, a thermometer, and a distillation tube, and heated under a nitrogen gas atmosphere. While stirring, 180
°C (220 °C in Comparative Production Example 1 and Production Example 5)
The reaction was started by heating to . After that, heating and stirring were continued for 3 hours, and after the distillation of ethanol or methanol produced by the reaction stopped, the pressure inside the reactor was gradually reduced to 1 mmHg at the same temperature.
Thereafter, excess ethylene glycol was distilled out under the above temperature and pressure for 4 hours, and after the distillation stopped, the reaction was terminated to obtain a photosensitive polyester resin. The above results are listed in Table 1. (2) Preparation of photosensitive resin composition A resin solution was prepared by dissolving each photosensitive polyester resin in dichloroethane, and a sensitizer and a phthalocyanine pigment were added to this solution to prepare a photosensitive resin composition. (3) Evaluation of photosensitive resin compositions Each photosensitive resin composition was coated on an anodized aluminum plate with a flourer after the surface was grained, and this was dried to produce a printing original plate. (a) Photosensitivity A step wedge with a height difference of 0.15 is placed in close contact with each original plate, and an output is placed 1 m away from the step wedge.
The original plate was exposed to light for 60 seconds using a 1KW metal halide lamp, and then the original plate was developed with a mixture of γ-butyrolactone and 85% phosphoric acid (98/2 volume ratio). Photosensitivity was exhibited with the highest number of insolubilized plates. (b) Printing durability and ink receptivity Each original plate was placed in close contact with the negative film of the test chart, and the output was set 1 m away from the negative film.
The above original plate was exposed for 30 seconds using a 1KW metal halide lamp, and then the original plate was developed with a mixed solution of γ-butyrolactone and 85% phosphoric acid (98/2 volume ratio) to produce a printing plate. Each printing plate was attached to a four-color lithographic printing machine, and an actual printing test using this machine was conducted using standard ink. Printing durability was indicated by the maximum number of prints at which a printed image faithful to the original image could be obtained without thickening of halftone dots or plate offset. Good or bad ink receptivity was determined by whether or not a clear image was obtained without blurring or poor ink adhesion on the printed matter. The above results are listed in Table 2.

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Claims (1)

[Scope of Claims] 1 At least a part of the polyhydric carboxylic acid unit contains a dicarboxylic acid unit having a photosensitive unsaturated double bond adjacent to an aromatic nucleus, and at least a part of the polyhydric alcohol unit has the general formula ( 1) (In the formula, R ₁ and R ₂ each represent an alkylene group having 2 to 4 carbon atoms, R ₃ and R ₄ each represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and l and m each represent 1 or more represents an integer of
l+m is an integer from 2 to 20. ) A photosensitive polyester resin composition comprising a photosensitive polyester resin containing a glycol unit represented by the following formula as a film-forming component. 2. The composition according to claim 1, wherein the dicarboxylic acid unit having a photosensitive unsaturated double bond adjacent to an aromatic nucleus is a unit represented by the following general formula. (In the above formulas (2) to (8), R ₅ and R' ₅ are hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, and 1 to 4 carbon atoms, respectively.
represents an alkoxyl group halogen atom or nitro group, R ₆ represents an alkylene group having 2 to 4 carbon atoms, n represents an integer of 1 to 4, p represents an integer of 1 to 5, and q represents an integer of 1 to 5. represents an integer. ) 3 The weight average molecular weight of the photosensitive polyester resin is
5,000 to 120,000, the composition according to claim 1 or 2. 4. The composition according to claims 1 to 3, wherein the content of dicarboxylic acid units having a photosensitive unsaturated double bond adjacent to an aromatic nucleus is 30 to 100 mol% of the total polycarboxylic acid units. thing. 5. The composition according to claims 1 to 5, wherein the content of glycol units represented by general formula (1) is 2 to 100 mol% of the total polyhydric alcohol units.