JPS6314140A - Photosensitive composition and photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE:To improve plate wear by incorporating an o-quinonediazide compd., alkali soluble resin and coupler which induces a diazocoupling reaction in basic environment into a titled compsn. CONSTITUTION:The o-quinonediazide compd., the alkali soluble resin and the coupler which induces the diazocoupling reaction in the basic environment are incorporated into the above-mentioned compsn. The o-quinonediazide compd. is the ester compd. of an o-quinonediazide sulfonic acid and a polycondensation resin of phenols and aldehyde or ketone and is more particularly adequately a compd. having an o-naphthoquinone diazide sulfonyl group. The polycondensation resin is particularly preferably the resin obtd. by condensing the phenols and aldehyde or ketone in the presence of an acidic catalyst. The coupler which induces the diazocoupling reaction in the basic environment refers to the coupler with forms an azo compd. by reacting with an arom. diazo compd. in the basic environment and is exemplified by arom. oxy compd., etc., such as phenol and naphthols.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a positive-working photosensitive lithographic printing plate and a photosensitive composition suitable for the same, and more specifically, to a positive-working photosensitive lithographic printing plate and a photosensitive composition suitable for the same. The present invention relates to a positive-working photosensitive lithographic printing plate and a photosensitive composition suitable therefor.

(Prior Art) Usually, an 0-quinonediazide compound is widely used as a photosensitive component in the photosensitive layer of a positive photosensitive lithographic printing plate.

However, in the photosensitive lithographic printing plate using such an 0-quinonediazide compound, the film strength of the photosensitive layer in the image area is weaker than that of a negative photosensitive lithographic printing plate, and the photosensitive layer in the image area and the support The printing durability was poor due to the poor adhesion of the body.

Conventionally, methods for improving the printing durability of positive photosensitive lithographic printing plates using O-quinonediazide compounds include exposure,
A method of heat treatment at high temperature after development is generally used. However, during heating, the 7-mer component of the resin may volatilize from the photosensitive layer in the image area and adhere to the support in the non-image area. At this time, when printing is performed using this printing plate, there is a problem in that scumming is likely to occur.

Also, JP-A-50-96304 and JP-A-50-11022
The publication describes a technique of forming a photosensitive layer into a multilayer structure, adding a highly abrasion-resistant resin to the upper layer, and adding an adhesion improving agent to increase the strength of the image and improve stiffness. There is. However, compared to the above-mentioned high-temperature heat treatment method, the above-mentioned 2
With one technique, sufficient printing durability was not achieved.

Furthermore, in JP-A-60-192948, a layer containing an 0-naphthoquinonediazide compound and a coupling component that causes a diazo coupling reaction, and a silicone rubber layer are sequentially provided on a support to form a non-image area. This paper describes a technology for creating a negative-working photosensitive lithographic printing plate that does not require dampening water and has improved resistance to processing agents. However, when the above structure excluding the silicone rubber layer is applied to a normal positive-working photosensitive lithographic printing plate, it is difficult to develop it without using an organic solvent because of its poor alkali solubility, or even if it is possible, its development tolerance is low. is extremely bad. Furthermore, since the film strength was low, the printing durability was poor.

Furthermore, JP-A No. 60-191261 discloses that after exposing and developing a photosensitive lithographic printing plate containing an electron beam curable compound in the photosensitive layer, the printing durability is improved by irradiating it with an electron beam. The technology is described.

However, the electron beam irradiation 9A device is expensive and expensive.

Furthermore, when the electron beam curable compound is developed with an alkaline aqueous solution, the photosensitive layer in the non-image area of the printing plate is completely dissolved, especially when the developing ability is reduced due to fatigue due to large-scale processing or deterioration due to air oxidation. It may not be possible to do so. Further, in such a case, when printing is performed using the printing plate, there is a drawback that scumming occurs.

(Problems to be Solved by the Invention) Therefore, the purpose of the present invention is to provide excellent printing durability and to achieve the same developability as when processed with a standard developer even when processed with a developer with reduced processing capacity. Show. It is an object of the present invention to provide a positive-working photosensitive lithographic printing plate having excellent development tolerance and good printability without causing scumming during printing. Another object of the present invention is to provide a photosensitive composition suitable as a photosensitive layer of such a positive-working photosensitive lithographic printing plate.

(Means for Solving the Problems) The above-mentioned object of the present invention is to provide a photosensitive composition containing an O-quinonediazide compound, an alkali-soluble resin, and a coupler that causes a diazo coupling reaction in a basic environment. This is achieved by a photosensitive lithographic printing plate having a photosensitive layer comprising a photosensitive composition and a photosensitive composition on a support.

(Specific structure of the invention) The present invention will be explained in detail below.

The 0-quinonediazide compound of the present invention is an ester compound of 0-quinonediazide sulfonic acid and a polycondensation resin of phenol and aldehyde or ketone, and has at least one 0-quinonediazide sulfonyl group, preferably 0-benzoquinonediazide sulfonyl group. or an 0-naphthoquinonediazide sulfonyl group, and compounds having an 0-naphthoquinonediazide sulfonyl group are particularly preferred.

The polycondensation resin is preferably one in which phenols and aldehydes or ketones are condensed, particularly in the presence of an acidic catalyst. Examples of the phenols include phenol, 0-cresol, m-cresol, p-cresol, 3,5-xylenol, carvacrol, thymol, and p-alkyl group (1 to 8 carbon atoms) substituted phenol. Examples include dihydric phenols, catechol, resorcinol, dihydric phenols such as hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Among these, preferred are divalent and trivalent polyhydric phenols, and more preferred is pyrogallol. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Among these, formaldehyde and benzaldehyde are preferred. Furthermore, examples of the ketone include acetone, methyl edyl ketone, etc., with acetone being preferred.

When synthesizing the polycondensation resin, FMM-free or In-containing hydrochloric acid, oxalic acid, sulfuric acid, phosphoric acid, phosphorus oxychloride, etc. are used as acidic catalysts, and the blending ratio of phenols and aldehydes or ketones is as follows: The aldehyde or ketone is used in an amount of 0.7 to 1.0 mole part per mole part of the phenol. However, when aldehyde or ketone is used as the reaction solvent, the mixing ratio is not limited to the above. Examples of reaction solvents used include alcohols such as methanol and ethanol, acetone, water, and tetrahydrofuran.

After reaction at a predetermined temperature (-5 to 120°C) for a predetermined time (3 to 48 hours), heat under reduced pressure, wash with water, and dehydrate.
Alternatively, the reactant can be obtained by precipitating water.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, m-cresol/formaldehyde resin, m-, p-mixed cresol/formaldehyde resin, phenol/cresol/formaldehyde resin, phenol/benzaldehyde resin, and cresol/benzaldehyde. 61 resin, resorcinol benzaldehyde resin, resorcinol formaldehyde resin, pyrogallol formaldehyde resin, pigallol acetone resin, pyrogallol benzaldehyde resin, hydroquinone, formaldehyde resin, catechol formaldehyde resin, and the like. Of these, the preferred ones are:
They are pyrogallol formaldehyde resin, resorcinol benzaldehyde resin and pyrogallol acetone resin. Most preferred is pyrogallol acetone resin.

The molecular weight (borisdyrene standard) of the polycondensation resin is such that the weighted average molecular weight ωMW is 5.0×1Q2 to 7.0×103,
The number average molecule ffiMn is 4. OX i Q2~3.5X
The range of MW is preferably 103, more preferably MW is 7.
．． Ox 102-2.5x 103, Mn 9. OX
1Q 2-2. It is in the range of OX 103.

The molecular weight of the resin is measured by GPC (gel permeation chromatography).

The number-average molecule ffiMn and the weight-average molecule ffiMW were determined by smoothing the peaks in the oligomer region by the method described in Morio Tsuge, Tatsuya Miyabayashi, and Masayuki Tanaka, "Journal of the Chemical Society of Japan," pages 800 to 805 (1972). (Connecting the center of the peak and the center of the valley).

The 0-quinonediazide compound of the present invention can be prepared by dissolving the polycondensation resin of the phenol and aldehyde or ketone in a suitable solvent such as dioxane, adding 0-quinonediazide sulfonic acid chloride to the solution, and stirring with heating. At the same time, alkali carbonate is added dropwise to the desired point to esterify the product.

In the ester compound, the condensation rate of 0-naphthoquinonediazide sulfonic acid chloride with respect to the OH group of the phenol (reaction rate % with respect to one OH group) is 5 to 50.
%, more preferably 10 to 50%, still more preferably 10 to 40%. The condensation rate is calculated by determining the content of sulfur atoms in the sulfonyl group by elemental analysis.

The content of the O-quinonediazide compound in the photosensitive composition of the present invention is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight.

The alkali-soluble resin of the present invention includes hydroxy group-containing polymers such as polyhydroxybenzoate, polyvinylhydroxybenzal, polyhydroxystyrene, poly-p-hydroxyphenyl methacrylamide, etc.
Carboxyl group-containing polymers such as polyvinyl acrylic acid and polyvinyl methacrylic acid, polymers containing acid anhydrides such as maleic anhydride polymers, novolak resins such as phenol formaldehyde resins and cresol formaldehyde resins, and two or more of the above resins. Examples include combinations. Among these, preferred is novolak resin.

The novolak resin is obtained by polycondensing phenols and formaldehyde in the presence of an acidic catalyst, and the phenols include phenol, 0-cresol, m-
1iii such as cresol, p-cresol, xylenol, carvacrol, thymol and α-naphthol;
Examples include dihydric phenols such as i-phenol, catechol, resorcinol and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Of these,
Phenol, 0-cresol, m-cresol and p-
A copolycondensation resin of at least one selected from cresol and formaldehyde is preferred.

Specific examples of novolac resins include phenol-formaldehyde resin, m-talesol-formaldehyde resin, 0-cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate vi4 resin,
m-cresol-p-cresol-formaldehyde copolycondensate resin, 〇-cresol/p-cresol/formaldehyde copolycondensate resin, JP-A-55-57841
@ Phenol-m-cresol- described in the publication
Examples include p-talesol-formaldehyde copolycondensate resin, phenol-〇-cresol-p-cresol-formaldehyde copolycondensate resin, and the like.

In addition, examples of polycondensation resins of polyhydric phenols and formaldehyde include catechol-formaldehyde resins and hydroquinone-formaldehyde resins described in JP-A-59-86046.

Among the above novolac resins, phenol-1-cresol-〇-cresol-formaldehyde resin is preferred.

The content of the novolak resin in the photosensitive layer is preferably 30 to 95% by weight, more preferably 50 to 85% by weight, based on the total solid content of the photosensitive layer.

The molecular weight of the novolak resin is preferably Mn of 4.
Ox 1 Q2~4.5x 103, Mw is 2.0x1
03 to 1.5×104, more preferably Mn is 1, Ox
103-3. Ox 103, Mw is 6.0×103~
It is 1.5X1Q4. The molecular weight of the resin is measured in the same manner as for the 0-quinonediazide sulfonic acid ester described above.

The coupler that causes a diazo coupling reaction in a basic environment of the present invention is one that reacts with an aromatic diazo compound in a basic environment to produce an azo compound, and is a compound that produces an azo compound, such as an aromatic oxy compound such as phenol or naphthol. Examples include active methylene compounds and phenol ethers, heterocyclic compounds such as virol, pyrazolone, and pyridone, and polymers having the above-mentioned coupler residues in the main chain or side chain. Polymers are particularly preferred.

Particularly preferred examples include naphthols, phloroglucin, pyrazolones, phthalimides, indoxyls,
Examples include indacylones, acetamides, and β-ketoesters, and the most preferred are polymers of pyrazolones.

Further, as the coupler polymer, at least one monomer selected from α,β-unsaturated carboxylic acids, alkyl acrylates, alkyl methacrylates, maleic anhydride, p-hydroxyphenyl methacrylamide, etc.
A copolymer of a species and a monomer represented by the following general formula (I) is preferred.

CH2=C-A-Q (I) General formula (I>
, R represents a hydrogen atom or a methyl group, and A represents -C
It represents OO-1-〇- or -CONH-, and Q represents a coupler residue that causes the aforementioned diazo coupling reaction.

The above-mentioned copolymer can be easily obtained by copolymerization in the presence of a commonly used polymerization initiator such as 7-zopisisobutyronitrile.

The heavy average molecular weight (il MVl) of the copolymer is MW=1
．． It is in the range of 0x103 to 1.0x1Q5, preferably Mw = 1. The range is OX 103 to S, 0x104.

The coupler of the present invention contained in the photosensitive layer is:
O-gynondiazide residue contained in the photosensitive layer! ! It is preferably contained in an amount of 0.1 to 10 equivalents per i1 current, particularly preferably 0.1 to 1.0 equivalents.

The photosensitive composition of the present invention includes O of the present invention as described above.
In addition to the quinonediazide compound, the alkali-soluble 41[I, and the coupler materials that cause a diazo coupling reaction in a basic environment, the additives may also be included if necessary. Various low molecular compounds such as phthalate esters, triphenyl phosphates, maleate esters are used as plasticizers, surfactants are used as coating properties improvers,
Examples include fluorine-based surfactants, nonionic surfactants such as ethyl cellulose polyalkylene ether, and printout materials for forming visible images upon exposure. Printed materials are composed of a compound that generates an acid or a T1 leaving group when exposed to light, and an organic dye that changes its color tone by interacting with this compound. Examples of compounds that generate an acid or a M leaving group when exposed to light include: It is described in Japanese Patent Application Laid-Open No. 50-36209.

0-Naphthoquinonediazide-4-sulfonic acid halide, trihalomethyl-2-pyrone and trihalomethyl-triazine described in JP-A-53-36223, O described in JP-A-55-6244 - Ester compound of naphthoquinonediazide-4-sulfonic acid chloride and phenol or aniline having an electron-withdrawing substituent, helomethyl-oxadiazole described in JP-A-55-77742 Examples include compounds and diazonium salts.

In addition, examples of the above-mentioned d dyes include Goctoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.], Oil Blue #603 [manufactured by Orient Chemical Co., Ltd.], Patent Pure Blue [manufactured by Sumitomo Mikuni Chemical Co., Ltd.], and Crystal Violet. Tutto, brilliant green, ethyl violet, methyl green, erythrosin B, pacific tuxin, malachite green, oil red, m~cresol purple, rhodamine B1 auramine, 4-1)-diethylanophenylimino naphthoquinone, cyano-p-diethylamino Examples include triphenylmethane-based, diphenolmethane-based, oxazine-based, xanthine-based, iminonaphthoquinone-based, adimethine-based, and anthraquinone-based dyes represented by phenylacetanilide.

Moreover, a sensitizer for improving sensitivity can also be added to the photosensitive composition of the present invention. Examples of sensitizing agents include gallic Pli derivatives described in JP-A-57-118237, and five-membered cyclic acid anhydrides such as those described in JP-A-52-80022, such as phthalic anhydride. , tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, succinic anhydride, pyromellitic acid, itaconic acid, etc., and 6-membered cyclic acid anhydrides as described in JP-A-58-11932. Examples include glutaric anhydride and its derivatives. Among these, cyclic acid anhydrides are preferred, and 6-membered cyclic acid anhydrides are particularly preferred.

In the photosensitive lithographic printing plate of the present invention, the photosensitive composition of the present invention constituting the photosensitive layer may be mixed with various solvents such as methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate,
Cellosolves such as ethyl cellosolve acetate, dimethylformamide, dimethyl sulfoxide, dioxane,
It can be formed by dissolving it in acetone, cyclohexanone, trichloroethylene, methyl ethyl ketone, etc., or a mixed solvent of two or more of the above to prepare a photosensitive coating solution, and coating this on a support and drying it.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating can be used.

Supports on which a photosensitive layer using the photosensitive composition of the present invention is provided include metal plates such as aluminum, zinc, copper, uA, etc., and metals plated or vapor-deposited with chromium, zinc, copper, nickel, aluminum, iron, etc. Examples include board, paper, plastic film, paper coated with wood grain, paper covered with gold foil such as aluminum, and plastic film treated to make it hydrophilic. Among these, aluminum plates are preferred. When an aluminum plate is used as a support, it is preferably subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. Known methods can be applied to these treatments. Examples of the graining treatment include a mechanical method and an electrolytic etching method. Examples of mechanical methods include ball polishing, brush polishing, liquid honing, and puff polishing. The various methods described above can be used alone or in combination depending on the composition of the aluminum material. Preferred is electrolytic etching.

Electrolytic etching is carried out in a bath containing one or more acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid. Graining treatment! After 1'), if necessary, desmut treatment is performed using a water-soluble alkali or acid for neutralization, followed by washing with water.

The anodic oxidation treatment is performed by electrolyzing using an aluminum plate as an anode using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc. as an electrolytic solution. The formed anodic oxide film m is 1 to 50110/d
v' is appropriate, preferably 10-40 +B/d
It is i'. For anodizing, for example, an aluminum plate is immersed in phosphoric acid solution H ('J'n Pi 85% H
: 351Q, M (Vl): prepared by dissolving 20o in water) to dissolve the oxide film, and it is determined by measuring the weight change of the aluminum plate before and after the film is dissolved.

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition, the aluminum plate support may be subjected to subbing treatment with an aqueous solution of a water-soluble polymer compound or a metal salt such as fluorinated zirconate.

Generally, when contact printing a film original onto a photosensitive lithographic printing plate, the printing frame is vacuumed, but a method for improving this vacuum adhesion is also a positive photosensitive method using the photosensitive composition of the present invention. It can be applied to lithographic printing plates. Methods for improving vacuum adhesion include mechanically creating unevenness on the surface of the photosensitive layer, scattering solid powder on the surface of the photosensitive layer,
A method of providing a matte layer on the surface of a photosensitive layer as described in JP-A-50-125805, and JP-A-55
Examples include a method of heat-sealing a solid powder onto the surface of a photosensitive layer, as described in Japanese Patent No. 12974.

When the photosensitive lithographic printing plate of the present invention is used, a positive transparent film is brought into close contact with the photosensitive lithographic printing plate, and a light source for printing, such as an ultra-high pressure mercury lamp, is used.
It is exposed with a metal halide lamp or the like, developed with an alkaline developer, and used as a printing plate.

The coupling reaction between the coupler of the present invention and the O-quinonediazide compound is carried out during the development process.

Examples of alkaline developers include sodium hydroxide,
Examples include aqueous solutions of alkali metal salts such as potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, sodium diphosphate, and sodium triphosphate, and amines such as triethanolamine and jetanolamine. .

The concentration of the alkali metal salt and amines is preferably 0.1 to 10% by weight. Further, an anionic surfactant, an antifoaming agent, and an alcoholic organic solvent can be added to the developer as necessary.

(Examples) Hereinafter, the present invention will be explained using Examples, but the present invention is not limited thereto.

Example 1 After degreasing an aluminum plate with a V width of 0.24 mm in a 5% aqueous sodium hydroxide solution, 0.5 mol f! A
Temperature: 25°C, current density: 60A/dm2 in acid aqueous solution
An electrolytic etching treatment was performed under conditions of treatment time: 30 seconds. Next, a desmut treatment was performed with a 5% aqueous sodium hydroxide solution, and then an anodization treatment was performed in a sulfuric acid solution. When the anodic oxide film 8 was measured using the method described above, it was found to be 20
II1g/df. Next, the support was immersed in a hot aqueous solution at 90° C. for pore sealing treatment to obtain a support.

Subsequently, a photosensitive coating solution having the composition shown below was coated on the aluminum plate support using a spin coater and dried at 100° C. for 4 minutes to obtain a photosensitive lithographic printing plate (A).

(Photosensitive coating liquid composition) Naphthoquinone-(1,2)-diazide-(2)-5-
Esterified product of sulfonic acid sulfur O-ride and pyrogallol acetone resin (number average molecule fi1Mn of pyrogallol acetone resin = 1140, weight average molecular weight MW-1
710, condensation rate = 33 mol%) ... 1,89 Copolycondensation resin of phenol, 1-cresol, p-cresol and formaldehyde (weight ratio of phenol, m-cresol and p-cresol during synthesis) 20:48
:32)...3.1g・Polymer compound having the structure of the following formula (II) (mffi average molecule ff1Mw =
2. Ox 10')... 3.3g ・Novolak resin synthesized from p-tert-octylphenol and formaldehyde and naphthoquinone-(
Esterified product with 1,2)-diazide-(2)-5-sulfonic acid chloride (heaviest average molecular weight of the novolac resin MW=1300, condensation rate -50 mol%)
...0.082 (1 formula (n)) Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) ...0.08 (tomethyl cellosolve ...100112
The coating weight of the photosensitive lithographic printing plate (A) after drying was about 22 m (J/di').

The molecular weight of the pyrogallol acetone resin and other novolac resins was measured using GPC (gel permeation chromatography).

The GPC measurement conditions are as follows.

Equipment: Hitachi Model 635, Separation column: Showa Denko (
MShodex A 802, A303 and A
804 were connected in series, temperature: room temperature, solvent: tetrahydrofuran, flow rate: 1.5 wR/min, and a calibration curve was prepared using polystyrene as a standard.

A step tablet for sensitivity measurement (NO12 manufactured by Eastman Kodak Company) was placed on the photosensitive lithographic printing plate thus obtained.
, 21 levels of gray scale with a density difference of 0.15) and a positive film of the image pattern were brought into close contact with each other, and a 2KW metal halide lamp (idle fin 2 manufactured by Iwasaki Electric Co., Ltd.) was used.
000) as a light source and exposed for 70 seconds under the conditions of 8.0 Ill W/C 2. Next, this sample was developed with a 4% potassium metasilicate aqueous solution at 25° C. for 45 seconds, and the non-image area was completely removed to obtain a lithographic printing plate. When the sensitivity was measured using the gray scale of the step tablet, the 3172nd stage was completely developed (clear). Next, in order to examine development acceptability, we used the standard 4
% potassium metasilicate aqueous solution, and a developer whose alkaline concentration was reduced, and using the sample exposed for 70 seconds, the developing ability was determined. The developability with a developer whose developing ability has decreased (under-developability) and the developability with a developer whose developing ability has become excessive (over-developability) were investigated. In examining under-developability, the film was developed with 2.4% and 2.1% potassium metasilicate aqueous solutions at 25° C. for 45 seconds, and the solubility of the non-image area was determined. The more diluted the developer dissolves the photosensitive layer in the non-image area, the better the under-developability will be. In addition, to examine over-developability, development was performed at 25°C for 60 seconds with a 6.0% potassium metasilicate aqueous solution and at 25°C for 90 seconds with a 7.2% potassium metasilicate aqueous solution, and the number of solid stages was determined. (The lowest number of stages at which the photosensitive layer remains completely in the gray scale of the step tablet) is measured, and this is compared with the number of solid stages when standard development (4% potassium metasilicate aqueous solution, 25°C, 45 seconds) begins. I found the difference between The smaller the difference in the number of solid steps is and the closer it is to standard development, the less erosion of unexposed materials and the better the over-development performance. Good development @ tolerance means that both under-development property and over-development property are good.

In addition, in order to examine printability and printing durability, printing was carried out by applying the above lithographic printing plate to an offset printing machine (Hamaduster 9000 DX), and until the image area was damaged and printing became impossible. The printing durability was evaluated based on the number of printed matter obtained. In addition, it was determined whether background smear occurred during printing.

The evaluation results of sensitivity, development tolerance, printability, and printing durability are summarized in Table 1.

Comparative Example 1 On the aluminum plate support prepared in Example 1, a compound of formula (II) was prepared from the photosensitive coating solution of Example 1 except for the co-condensed resin of phenol, m-cresol, p-cresol, and formaldehyde. An additional 3.19 polymer compounds having the structure were coated and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (B). The coat weight after drying was approximately 22807d112.

As in Example 1, sensitivity, development tolerance, printability, and printing durability were examined. The above results are shown in Section 1 below along with other examples.

Comparative Example 2 On the aluminum plate support produced in Example 1, phenol, m-cresol and p - An additional 3.3 g of a copolycondensation resin of cresol and formaldehyde was applied and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (C). The coating weight after drying was approximately 22 mg/di''. After exposure and development in the same manner as in Example 1, sensitivity and development tolerance were examined, heat treatment was performed at 250°C for 8 minutes using a burning machine. The printability and printing durability of this lithographic printing plate were examined in the same manner as in Example 1. The above results are shown in Section 1 below along with other examples.

Comparative Example 3 On the aluminum plate support produced in Example 1, from the composition of the photosensitive coating liquid of Example 1, <It) formula! Except for the polymer compound having the +4 structure, a compound to which neopendel glycol methacrylate (described in JP-A No. 60-191261, Example 1) of the same m was added was coated and dried in the same manner, and photosensitive A lithographic printing plate (D) was obtained.

The coating weight after drying was approximately 22 mQ/dv'.

Next, using this photosensitive planographic printing plate (D), Example 1
Similarly, sensitivity and development tolerance were examined, and further, using an electron beam irradiation device, 3X10-8C was
/Cf was irradiated.

Regarding this lithographic printing plate, printing suitability and printing durability were examined in the same manner as in Example 1. The above results are shown in Section 1 below along with other examples.

In the under-discipline evaluation in Table 1, The O mark indicates that the photosensitive layer in the non-image area has been completely dissolved and removed.

Part of the Δ mark remains as above.

The x mark indicates that the same as above is hardly dissolved.

It means that.

In addition, in over-development, the numerical value means the difference in the number of solid stages from standard development.

From the results of Example 1 and Comparative Examples 1 to 3 above, the following is clear. In other words, from a comparison of Example 1 and Comparative Example 1, if no other resin is included in addition to the diazo coupler, the sensitivity will drop by one step, the under-developability will decrease, and the printability and printing durability will deteriorate. . Further, from a comparison between Example 1 and Comparative Example 2, when a novolak resin is used as the thermosetting resin and a burning treatment is performed, the printing durability is good, but scumming occurs during printing. Furthermore, from a comparison between Example 1 and Comparative Example 3, when an electron beam curable resin is used, under-developability decreases and background smear occurs during printing. Photosensitive lithographic printing plates (B) to (B) of Comparative Examples 1 to 3 other than Example 1
It can be seen that D) has a major drawback in at least one of the characteristics shown in Table 1.

According to a performance comparison of photosensitive lithographic printing plates comprehensively evaluated based on several properties shown in Table 1, the photosensitive lithographic printing plate (A) of the present invention has excellent over-developability and under-developability. , has a wide range of development tolerance, and is comprehensively excellent in sensitivity, printing durability, and suitability for printing 1i11.

(Effects of the Invention) As explained above, the photosensitive planographic printing plate of the present invention has the following features:
It has excellent printing durability and can produce a large number of good prints without causing background smudges during printing.

Furthermore, even if a developer is processed with a developer whose developing ability has decreased due to fatigue or deterioration due to air oxidation due to large-volume processing, the developing ability may exceed the specified level due to excessive replenishment or an increase in bath temperature due to rising air temperature. Even when processed with a standard developer, in either case, it shows the same developability as when processed with a standard developer, and has a wide range of development acceptability.

Claims (2)

[Claims] (1) A photosensitive composition comprising an o-quinonediazide compound, an alkali-soluble resin, and a coupler that causes a diazo coupling reaction in a basic environment. (2) Photosensitive lithographic printing characterized by having on a support a photosensitive layer comprising a photosensitive composition containing an o-quinonediazide compound, an alkali-soluble resin, and a coupler that causes a diazo coupling reaction in a basic environment. Edition.