JPS62124557A - Photosensitive composition and photosensitive lithographic plate material - Google Patents

Abstract

PURPOSE:To obtain a photosensitive composition high in photosensitivity, wide in processing allowance at the time of development, and superior in resistance to processing chemicals by using a novolak type resin containing 2 different kinds of phenols only in combination with a positive type photosensitive material composed of a compound capable of generating acid on irradiation of actinic rays and an acid-decomposable type compound. CONSTITUTION:The photosensitive resin composition contains the compound capable of generating acid on irradiation of actinic rays and a compound having at least one acid-decomposable bond, and the novolak type resin containing 2 different kinds of phenols. As the acid-decomposable compound, ones such as having an acetal or ketal group, or polymers each having an orghocarboxylic ester group on the principal chain, are used, preferably, in an amount of 5-70wt% of the total solid of the photosensitive resist-forming composition. A preferable content of the compound capable of generating acid on irradiation of actinic rays is 0.1-10wt% of the total solid weight of the photosensitive resin layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photosensitive composition and a photosensitive lithographic printing plate material containing the composition in a photosensitive layer. The present invention relates to a novel photosensitive composition having excellent development tolerance and processing chemical resistance ζ, and a photosensitive lithographic printing plate material thereof.

[Conventional technology]

When irradiated with actinic light, phosphoric acid is generated, and the generated acid causes a second reaction, that is, an acid decomposition reaction, and as a result, the exposed area becomes soluble in the developer (using the principle of 1). Various types of photosensitive compositions have been known in the past.

Examples of this include JP-A-48-89003, JP-A-51-120714, JP-A-53-13342, JP-A-55-12995, JP-A-55-126236, and JP-A-56.
-17345, 60-37549, and 60-
121446. These exhibit a photosensitivity of -1 and a height of 1.

In the above-mentioned literature, it is stated that these photosensitive compositions are preferably used by mixing with an alkali-soluble resin, etc., and that cresol-formaldehyde novolac resin h (used in Example P1) There is.

[Problem that the invention seeks to solve]

However, when a novolak resin consisting of one type of phenol and formaldehyde, such as a phenol-formaldehyde novolak resin or l-cresol formaldehyde novolak resin, is used in the above photosensitive composition, the processing chemical resistance is poor (and the resistance during development is poor). It has been found that this method has the disadvantage that the development tolerance is also narrowed.

Therefore, an object of the present invention is to provide an improved photosensitive composition having high photosensitivity and wide development latitude during development.

Another object of the present invention is to provide a photosensitive composition that has high photosensitivity and improved resistance to processing chemicals.

Still another object of the present invention is to provide a lithographic printing plate material using the above photosensitive composition.

[Means for solving problems]

In order to achieve the above object, the inventors of the present invention have developed vA! As a result of continued research, we found (a) compounds that can generate acids when irradiated with actinic rays, (b) compounds that have at least one bond that can be decomposed by acids, and (c) two different types of phenols. It has been discovered that the above object can be achieved by using a photosensitive composition doweling a novolac resin containing the above-mentioned photosensitive composition. I have found that it can be achieved.

The present invention will be explained in detail below.

In the present invention, compounds having a bond that can be decomposed by an acid include, for example) C-O-C< bond or -33j
-0-C(: A compound having a bond or a compound that grows.

; Specific compounds having a C-0-C< bond include, for example, a compound having an acetal or ketal group;
Compounds having an orthocarboxylic acid ester group and/or carboxylic acid amide acetanol group described in JP-A No. 120714, polymers having an acetal or ketal group in the main chain described in JP-A-53-133429, JP-A-55 A compound containing an enol ether group as described in JP-A No. 12995, a compound having an N-acylimino carbonate group as described in JP-A-55-126236, or a main chain as described in JP-A-58-17345. Examples include polymers having orthocarboxylic acid ester groups.

Specific compounds having a psi-0-Cq bond include, for example, JP-A-80-37549 and JP-A-60-528.
Examples thereof include compounds described in No. 45 or No. 80-121446.

Examples of specific compounds having an ester group include compounds described in JP-A-60-3625 and JP-A-6G-10247.

Among these compounds having a bond that can be decomposed by an acid, compounds having a >st-o-c6 bond are preferred.

Among them, S described in Japanese Patent Application Laid-open No. 60-121446
Particularly preferred are compounds having one i-0-C(z bond) and at least one hydrophilic group.

As for the compounds that can be decomposed by these acids, l fffi may be used alone, or two or more types may be used as a mixture.

The content of these acid-decomposable compounds is preferably 5 to 70% by weight, particularly preferably 10 to 50% by weight, based on the total solid content of the photosensitive resist forming composition.

The photosensitive resin composition of the present invention requires doweling novolac resins containing two different types of phenols.

In this case, a mixture of two types of novolak resins (the phenol components of each novolac resin are different from each other) containing only lu type phenols as phenols may be used, but preferably 2FJ! The method is to use a copolycondensate of different types of phenols and active carbonyl compounds.

These phenols include all compounds in which at least one hydrogen atom bonded to an aromatic ring is substituted with a hydroxyl group, and specifically include phenol, 0-cresol, m-cresol, p-cresol, 3-cresol, etc. , 5-xylenol, 2.4-xylenol, 2.5-xylenol, carvacrol, thymol, catechol, resorcinol, hydroquinone, pyrogallol, phloroglucin, and an alkyl group (1 to 8 carbon atoms) substituted phenol.

Active carbonyl compounds include, for example, aldehydes and ketones, and specific examples include formaldehyde, acetaldehyde, benzaldehyde, acrolein, furfural, and acetone. 'Among these novolak resins obtained from phenols and active carbonyl compounds, preferred are those obtained by copolycondensation of formaldehyde and two selected from phenol, O-cresol, m-cresol and p-cresol. It is a resin that can be used.

For example, phenol/ugly-cresol/formaldehyde copolycondensate resin, phenol/p-cresol/formaldehyde copolycondensate resin, m-cresol/p-cresol/formaldehyde copolycondensate resin, 0-cresol/p-cresol・Formaldehyde copolycondensate resin, etc.

Among these, the most preferred novolac 1m is composed of m-cresol, p-cresol and formaldehyde.
It is a cresol/p-cresol/formaldehyde copolycondensate resin, and the preferred molar ratio of m-cresol and p-cresol is the molar ratio charged at the time of synthesis: m-cresol:p-cresol=6.5:
3.5-9.9: Q, 1 area.

These novolak resins mentioned above may be used alone or in combination of two or more.

The molecular weight (polystyrene standard) of Menji Novoladzuku resin is:
Preferably number average molecular weight Mnh' 3.00 Xl 0
” ~7.50xl O', weight average molecule Ek M v
is 1, oox103 to 3.0OxlO', more preferably Mn is 5.00x10'' to 4.0OxlO3, and Mw is 3.0OxlO' to 2.00XlO'.

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

Calculation of number average molecular weight Q M n and weight average molecular weight Mw is based on Morio Tsuge, Tatsuya Miyabayashi, and Masayuki Tanaka, “Journal of the Chemical Society of Japan,” 8.
By the method described on pages 00 to 805 (1972),
The test shall be performed by leveling the peaks of the oligomer region (connecting the centers of the peaks and valleys).

In addition, in the novolak resin, as a method for confirming the quantitative ratio of different 2tl phenols used in its synthesis, pyrolysis gas chromatography (Pyrol
ysis-gaschromatography, PG
C) is used. Regarding pyrolysis gas chromatography, its principles, equipment, and experimental conditions can be found, for example, in Nippon Kagaku Complete Edition, Takushoku Shinsho New Experimental Chemistry Course, Volume 19, Polymer Chemistry (1), pp. 474-485 (published in 1978 by Maruzen). The qualitative analysis method of novolak resin by pyrolysis gas chromatography is described in Morio Takushoku, Takashi Tanaka,
“Analytical Chemistry” by Masayuki Tanaka, Vol. 18, pp. 47-52 (19
The method shall be based on the method described in 1969).

The content of these novolac resins in the photosensitive composition is preferably 30 to 95% by weight, more preferably 50 to 90ffifa%.

The photosensitive composition of the present invention must further contain a compound that generates an acid upon irradiation with actinic rays. Such compounds include many known compounds and mixtures, such as diazonium salts, phosphonium salts, sulfonium salts and iodonium BF, -1PF6°, S
Salts such as bF@-1S j F a''-1CQ04-, organohalogen compounds, orthoquinonediazide sulfonyl chloride, and organometallic/organohalogen compounds are also active light-sensitive components that form or separate acids upon irradiation with actinic light. can be used.

In principle, all organic halogen compounds known as free-radical-forming photoinitiators can be used as photosensitive compounds capable of forming hydrohalic acids. Examples of such compounds are U.S. Pat.
No. 36.489, No. 3,779,778 and German Patent Application No. 2,243,621.

Also, for example, West German Patent Publication No. 2,610,84
No. 2, JP-A-54-74728, JP-A No. 55-77742
Compounds that generate acids by photolysis as described in Japanese Patent No. 57-16323 and Japanese Patent No. 60-3626 can be used.

Furthermore, 0-naphthoquinonediazide-4-sulfonic acid halide described in JP-A-50-36209 can also be used.

In the present invention, in addition to the above-mentioned compound having a trihalomethyl group in combination with a suitable dye, O-naphthoquinonediazide-4-sulfonic acid halide or JP-A-55-6244, JP-A-59-218442, etc. When the 0-naphthoquinonediazide group compound described in 1 is used in combination, a clear visual contrast with good stability over time is created between the unexposed area and the exposed area during exposure.

The content of these compounds that can generate acids upon irradiation with actinic rays can vary widely depending on the chemical properties and the composition or physical properties of the photosensitive resin layer, but the solid content of the photosensitive resin layer about 0.1 to about t for all ffl9 of
o weight% range is appropriate, preferably 0.2 to 5f
The fl content is in the range of %.

In addition to the materials described above, dyes, pigments, plasticizers, etc. can be added to the photosensitive composition of the present invention, if necessary, and if necessary depending on the purpose of use. For example, it is possible to add a so-called sensitizer (a compound that increases the acid generation efficiency of a compound capable of generating Fuki acid).

Examples of such compounds include naphthalene, anthracene, phenanthrene, chrysene, pyrene, perylene, p-dinitrobenzene, p-nitrodiphenyl, p-
Nitroaniline, 2.4-u nitroaniline, biclamide, 2-chloro-4-nitroaniline, 2.6-dichloro-4-nitroaniline, p-nitrophenol, 9-
Anthraldehyde, benzophenone, dibenzalacetone, p,p'-tumethylaminobenzophenone, Michler's ketone, l,4-naphthoquinone, anthraquinone, 1,2-benzanthraquinone, anthrone, 1,9
-benzanthrone, 3-methyl-1°3-diaza-1
, 9-benzanthrone and the like.

Other examples include acridine dyes, melonanine dyes, styryl dyes, etc. In addition, in this case, an amine compound may be added if necessary.

Examples of the dyes include Victoria 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.), Crystal Violet, Brilliant Green, Ethyl Violet, Typical examples include methyl green, erythrone B1 basic fuchsin, malachite green, oil red, m-cresol purple, rhodamine B1 auramine, 4-p-noedylaminophenyl imino naphthoquinone, Noanor p-noedylaminophenyl acetanilide, etc. triphenylmethane, diphenylmethane, oxazine, xanthine,
Examples include iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes. Plasticizers include various low-molecular compounds such as phthalate esters, triphenyl phosphates, maleate esters, and coating properties improvers include surfactants such as fluorine surfactants and ethyl cellulose polyalkylene ether. Nonionic surfactants such as typified by

Furthermore, in order to improve the oil sensitivity, a photosensitive resin obtained by condensing a lipophilic substituted phenol formaldehyde resin and a substituted phenol formaldehyde sulfonic acid chloride can be added. It is preferable that these oil sensitizing agents be contained in an amount of 01 to 5% by weight of the total composition of the photosensitive layer.

The photosensitive composition of the present invention is dissolved in a solvent that dissolves each of the above-mentioned components, and by coating and drying it on the surface of a support, for example, a photosensitive lithographic printing plate material or a photoresist (
For example, resin letterpress materials, printed wiring boards, etc.) can be formed.

The present invention is characterized not only by the photosensitive composition itself, but also by the lithographic printing plate material obtained using the photosensitive composition.

The case where a lithographic printing plate material is obtained using the photosensitive composition of the present invention will be described below.

Examples of solvents that can be used include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate, dimethyl formamide, dimethyl sulfoxide, dioxane, acetin,
Examples include cyclohexanone, trichloroethylene, and methyl ethyl ketone. These solvents may be used alone or in combination of two or more.

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. The coating amount varies depending on the application, but for photosensitive planographic printing plate materials, the solid content is preferably 0.5 to 5.09/m''.

In the photosensitive lithographic printing plate material using the photosensitive composition of the present invention, the support may be a metal plate such as aluminum, zinc, copper, or steel, or plated or plated with chromium, zinc, copper, nickel, aluminum, iron, etc. Examples include vapor-deposited metal plates, paper, plastic films, temporary glass, paper coated with resin, paper covered with metal foil such as aluminum, and plastic films treated to make them hydrophilic. Among these, aluminum plates are preferred. When an aluminum plate is used as a support for the photosensitive lithographic printing plate I7, it is preferable that the plate be subjected to surface treatments such as graining, anodizing, and if necessary, pore sealing.

Known methods can be applied to these treatments.

Examples of methods for graining include a pirate method and an electrolytic etching method.

Examples of the IVT method include a ball polishing method, a brush polishing method, a polishing method using liquid honing, and a puff polishing method. The various methods described above can be used alone or in combination depending on the composition of the aluminum material.

Electrolytic etching is carried out in a bath containing one or a mixture of two or more inorganic acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid.

After the graining process, desmutting is performed using an alkali or acid aqueous solution as necessary to neutralize the material, followed by washing with water.

The anodic oxidation treatment is performed by using an electrolytic solution containing 18 or more types of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc., and using an aluminum plate as an anode. The amount of anodic oxide film formed is 1 to 50 ra9/
dm” is appropriate, preferably 10 to 40 m9/
dm', particularly preferably 25 to 40 m9/
d+e''.The amount of anodized film is, for example, an aluminum plate coated with a phosphoric acid chromic acid solution (85% phosphoric acid solution: 35 mL).
The oxide film is immersed in chromium oxide (V[):209 prepared by dissolving it in 1Q of water) to dissolve the oxide film, and it is determined by measuring the change in weight after the surface of the temporary 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 temporary support may be subjected to a subbing treatment using a water-soluble polymer compound or an aqueous solution of a metal salt such as fluorinated zirconate.

In addition, when contact-baking a film original onto a photosensitive lithographic printing plate material, the printing frame is generally vacuumed, but a method for improving this vacuum adhesion is also photosensitive lithographic printing using the photosensitive composition of the present invention. It can be applied to plate materials. 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-5O-125805;
Examples include a method of heat-sealing a solid powder onto the surface of a photosensitive layer, as described in Japanese Patent No. 5-12974.

A photosensitive lithographic printing plate material to which the photosensitive composition of the present invention is applied can be used in the same manner as conventionally used ones. For example, a transparent positive film is exposed to light using a light source such as an ultra-high-pressure mercury lamp, metal halide lamp, xenon lamp, or tungsten lamp, or scanned with a laser beam, and then developed with a developer, leaving only the unexposed areas on the surface of the support. , a positive-positive relief image appears.

The phenomenon liquid used in the present invention is preferably an aqueous alkaline developer, and examples of the aqueous alkaline developer include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, and sodium diphosphate. , aqueous solutions of alkali metal salts such as trisodium phosphate. The alkali metal salt is preferably used in an amount of 0.05 to 20% by weight, more preferably 0.1 to 10% by weight.

Furthermore, an anionic surfactant, an amphoteric surfactant, or an organic solvent such as alcohol can be added to the current arfL as required.

Ethylene glycol monophenyl ether, benzyl alcohol, n-propyl alcohol, etc. are useful as organic solvents. The content of the organic solvent in the current AA composition is preferably 0.5 to 15% by weight, and more preferably 1 to 5% by weight.

〔Example〕

The present invention will be explained below with reference to examples, but the present invention is not limited thereto.

Example 1 An aluminum piece with a thickness of 0.24 mm was subjected to surface roughening treatment using a rotating nylon plano using an abrasive and water suspension, washed with water, and then alkaline etched in a 5% caustic soda aqueous solution. After washing with water, it was immersed in a 20% nitric acid aqueous solution at room temperature to perform desmutting. Next, anodization treatment was performed in a sulfuric acid solution. When the amount of anodic oxide film was measured using the surface method, it was found to be 20 m9/dm.
A sealing treatment was performed by immersing it in a hot water solution at 0°C.

Subsequently, a photosensitive coating solution having the following composition was applied to the aluminum support using a spin coater and dried at 100° C. for 4 minutes to obtain a photosensitive lithographic printing plate material.

(Photosensitive coating liquid composition) Silyl ether compound of p-xylylene glycol, tetraethylene glycol and nochloromethylsilane (
The following general formula (
+)) Weight average molecule m Mw = 16.500X / Y
= 50 / 50 (molar ratio) 2.149
・Copolycondensation resin of m-cresol, p-cresol, and formaldehyde (the molar ratio of each of ffl-cresol and p-cresol is 9.1, the weight is the average molecular weight QMw =
4.200, dispersion degree Mw/Mn=4.0.

~1n: Loss average molecular weight) 5.74
9. Victoria Pure Blue B OH (manufactured by Hodogaya Chemical Co., Ltd.) 0.059.2-
Trichloromethyl-5-[β-(2-benzofuryl)vinyl)-1,3,4-oxanoazole (Japanese Patent Application Laid-Open No. 1986-
Exemplary compounds described in Publication No. 138539 (lno
0.279・Ethyl cellosolve
100mf2 coating weight after drying is approximately 21 m9
/da+'.

The above silyl ether compound and m-talesol p-
The molecular weight and dispersity of the cresol copolycondensation resin are cpc (
It was measured using gel permeation chromatography. The GPC measurement conditions are as follows.

Equipment: Model 635 manufactured by Hitachi, Separation column: Showa Denko 15hodex A 802, A303 and A304
A calibration curve was prepared using polystyrene as a standard. Three of these were connected in series, the temperature was two room temperatures, the solvent was tetrahydrofuran, the flow rate was 1, 5 mQ/min, and polystyrene was used as a standard.

A step doublet (manufactured by Eastman Kodak Company, NO.
, 2, 21 levels of gray scale with a Q degree difference of 0.15) were placed in close contact, and a 2 kW metal halide lamp (Idol Fin 2000 manufactured by Iwasaki Electric Co., Ltd.) was used as the light source.
Exposure was performed for 30 seconds under the condition of 0 mW/cm'. Next, when this sample was developed in a developer prepared by diluting DP-4 (manufactured by Fuji Photo Film Co., Ltd.) 11 times with water at 25°C for 45 seconds, the non-image areas were completely removed and a lithographic printing plate was obtained. Ta. When the sensitivity was measured on the gray scale of the step tablet, the number of solid steps (the lowest number of steps at which the photosensitive layer remained completely in the gray scale of the step tablet) was 16 steps.

Next, in order to examine the tolerance of the phenomenon, we prepared a developer solution with a diluted alkali concentration and a developer solution with a higher alkali concentration, and used the sample exposed for 30 seconds. The development properties with respect to a developing solution (under-developability) and the developability with respect to a developer with excessive developing ability (over-developability) were investigated. The above phenomenon was determined by changing the dilution rate of DP-4 and developing at 25° C. for 45 seconds, and based on the solubility of the non-image area and the erosion property of the image area.

The more diluted the photosensitive layer in the non-image areas is dissolved, the better the under-developability will be, and the less erosion in the image area with the more alkali-concentrated phenomenon liquid, the better the over-developability will be. It's going to be a good thing.

Good development tolerance means that both under-development property and over-development property are good.

Next, in order to examine processing chemical resistance, we used Ultra Plate Cleaner (A), which is used as a cleaning liquid to remove background stains that occur in non-image areas during printing.

B, C, manufactured by Chemical Co., Ltd.) was examined.

The printing plate, on which an image with density differences is formed on the gray scale steps, is immersed in Ultra Plate Cleaner stock solution at room temperature for a predetermined time, then washed with water, and compared with the image area before immersion to determine the image area. The degree of attack against treatment chemicals was determined. As a result, the printing plate showed good treatment chemical resistance, with the image area being less likely to be eroded.

Comparative Example 1 The following photosensitive coating solution was applied to the same aluminum plate support as in Example 1 and dried to obtain a positive photosensitive lithographic printing plate material.

(Photosensitive coating liquid composition) - Silyl ether compound (used in Example!)
2.149 m-cresol formaldehyde novolac resin (weight average molecular weight Mw = 4,200, degree of dispersion My/Mn = 4.0)
5.749 Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.)
0.059・2-trichloromethyl-5-[β-
(2-Benzofuryl)vinyl 3-1.3.4-oxadiazole 0.279 Ethyl cellosolve The coating weight after drying of 100 m12 was about 21 m9/dm'.

In other words, a comparative example! The positive photosensitive lithographic printing plate material prepared in Example 1 is a novolac resin (Ill-cresol/p-cresol/formaldehyde novolac resin) used as a binder in the positive photosensitive lithographic printing plate material prepared in Example 1. instead of other novolak resins (
All samples were produced in the same manner using the same formulation except that Ill-cresol formaldehyde novolac resin) was used. Therefore, the difference between the positive photosensitive lithographic printing plate material of Example 1 and the positive photosensitive lithographic printing plate material of Comparative Example 1 is that the phenol component contained in the novolak resin used as a binder contains two different types of phenol components. Include or
The difference is whether it contains only one type of phenolic component.

Next, Examples using this photosensitive lithographic printing plate material! ,
! -Similarly, sensitivity, development tolerance, and processing chemical resistance were examined. The results are shown in Table 1.

Comparative Example 2 A photosensitive lithographic printing plate material was obtained in the same manner as in Example 1, except that the following compound was used in place of the silyl ether compound in the photosensitive coating solution of Example 1.

- Ester compound of naphthoquinone-(1,2)-cyanodo-2,5-sulfonic acid chloride and pyrogallol acetone resin (ifm average molecular Q M w = 1.7
00, condensation rate 40 mol%) The coating weight after drying was approximately 21 m9/dm''.

Next, using this photosensitive lithographic printing plate material, sensitivity, development tolerance, and treatment chemical resistance were examined in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 A photosensitive lithographic printing plate material was obtained in the same manner as Comparative Example 2, except that the following compound was used instead of the m-cresol/p-cresol/formaldehyde novolak resin in the photosensitive coating solution of Comparative flI2. Ta.

・m-cresol formaldehyde novolac resin (Things used in Comparative Example 1) The coating weight after drying was approximately 21 mg/dm'.

That is, the relationship between Comparative Example 2 and Comparative Example 3 is the same as the relationship between Example 1 and Comparative Example 1.

Next, using this photosensitive lithographic printing plate material, sensitivity, development tolerance, and treatment chemical resistance were examined in the same manner as in Example 1. The results are shown in Table 1.

As mentioned above, the sensitivity performed for Example 1 and Comparative Examples 1 to 3,
Table 1 summarizes the measurement results of phenomenon tolerance and processing chemical resistance.
become that way.

From the results of the above Examples and Comparative Examples, the following is clear. In other words, from the comparison of Example 1 and Comparative Example 1, when the novolak resin used together with the acid-decomposable compound contains two different types of phenols, it has very high photosensitivity and a very wide development tolerance. It is possible to obtain a photosensitive resin composition that has high properties and is also highly resistant to processing chemicals.

However, if the novolak resin used together with the acid-decomposable compound contains only one type of phenol, the development tolerance and processing chemical resistance will be extremely poor. Furthermore, from the results of Comparative Example 2 and Comparative Example 3, it was found that orthoquinone diazide compounds, which are positive-working photosensitive materials that have been commonly used in the past, were used in place of compounds that generate acids upon irradiation with actinic rays and acid-decomposed compounds. It can be seen that when using Novolak resin, development tolerance and processing chemical resistance are hardly affected by the type of novolac resin.

Example 2 A photosensitive coating solution having the following composition was applied to the aluminum support prepared in Example 1 and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate material.

(Photosensitive coating liquid composition) - Silyl ether compound (used in Example 1)
2.149 m-cresol p-cresol formaldehyde novolac resin (used in Example 1) 5.749 Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.)
0.059 ・2-Trichloromethyl-5-[β-(2-benzofuryl)vinyl]-1,3,4-oxadiazole 0.179 ・1.2-naphthoquinone-2-diazide-4-sulfonyl chloride 0 .19・Ethyl cellosolve 100mf2 Application after drying ff
1 fl was approximately 21 m9/dm''.

That is, the positive-working photosensitive lithographic printing plate material prepared in Example 2 contains 2-trichloromethyl-5-[β, which is used as a finishing generator in the positive-working photosensitive lithographic printing plate material prepared in ρJI. -(2-benzofuryl)vinyl)
-1,3,4-oxadiazole is partially replaced with 1,2-naphthoquinone-2-diazide-4-sulfonyl chloride.

Next, using this photosensitive lithographic printing plate material, the sensitivity, development tolerance, and treatment chemical resistance were examined in the same manner as in Example 1, and results similar to those in Example 1 were obtained.

Furthermore, as a result of examining the visual contrast between exposed areas and unexposed areas after exposure, it was found that the photosensitive lithographic printing plate material used in Example 1 showed that the visible contrast almost disappeared approximately 30 minutes after exposure. Regardless, the photosensitive lithographic printing plate material obtained in Example 2 had a clear visible contrast even after about 1 hour after exposure, and it was found that the visual contrast had good stability over time.

〔Effect of the invention〕

According to the present invention, only in a positive photosensitive material consisting of a compound that generates an acid upon irradiation with actinic rays and a compound that can be decomposed by an acid, a novolak resin containing different phenols of the 2Fi class can be used to achieve high photosensitivity. It has the effect that a photosensitive composition can be obtained which has a high degree of stability, wide development tolerance during development, and excellent processing chemical resistance.

Claims (2)

[Claims] (1) Contains (a) a compound that can generate an acid when irradiated with actinic rays, (b) a compound that has at least one bond that can be decomposed by an acid, and (c) a novolac resin containing two different types of phenols. photosensitive resin composition. (2) Contains on the support (a) a compound that can generate an acid upon irradiation with actinic rays, (b) a compound that has at least one bond that can be decomposed by an acid, and (c) two different types of phenols. A photosensitive lithographic printing plate material provided with a photosensitive layer containing novolac resin as its main component.