JPH0229748A - Photosensitive composition and photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain a positive type photosensitive composition having the high sensitivity, and a developer which does not cause foaming at the time of developing the title plate by incorporating an o-naphthoquinone diazide compd., an alkali-soluble resin and a specified activating agent such as polyoxy propylene alkyl ether, etc., in the title composition. CONSTITUTION:The photosensitive composition is composed of 10-50wt.% of an ester compd. of o-naphthoquinone diazide sulfonic acid and a polycondensation resin of a phenols which may be substd. with methyl group, and an aldehyde or a ketone, 20-90wt.% of a phenol cresol formaldehyde copolycondensation resin and 0.1-5wt.% of the activating agent selected from the group comprising polyoxypropylene alkyl ether, polyoxypropylene alkyl phenyl ether and polyoxypropylene alkyl ester. Thus, the photosensitive composition which is suitable for especially a positive type photosensitive printing plate, is obtd.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a photosensitive composition and a photosensitive lithographic printing plate, and more specifically, a photosensitive composition particularly suitable for a positive-working photosensitive lithographic printing plate. This article relates to a photosensitive lithographic printing plate using the same.

[Prior Art] A positive planographic printing plate has an ink-receptive photosensitive layer on a wood-philic support, imagewise exposes this photosensitive layer, and then develops it, leaving an image area and forming a non-image area. part is removed to form an image. In actual printing, the oleophilicity of the image area and the oleophilicity of the non-image area are utilized.

Usually, the photosensitive layer of a positive photosensitive lithographic printing plate contains an 0-quinonediazide compound as a photosensitive component and an alkali-soluble resin as a component for increasing film strength and alkali solubility.

[Question 8 to be solved by the invention] When performing so-called multi-sided printing, in which multiple film originals are printed one after another by changing their positions on a photosensitive lithographic printing plate using such a set of T & objects, the printing takes a long time. The focus of the work was to shorten the time, in other words, to increase sensitivity.

When a photosensitive layer using an 0-quinonediazide compound is handled under a white fluorescent light, it suffers from light damage, and when it is subsequently developed, the photosensitive layer in the image area is eroded and the film is thinned, resulting in a decrease in printing durability. This often causes failures where the performance decreases. Therefore, a photosensitive lithographic printing plate having a photosensitive layer with improved resistance to light fog caused by white fluorescent light (hereinafter referred to as "safelight property") is desired.

Furthermore, the development of photosensitive lithographic printing plates using 0-quinonediazide compounds is usually carried out with an alkaline aqueous solution developer, but the developing ability of the developer is subject to fluctuations under various conditions, such as fatigue due to large-volume processing and air pollution. Deterioration due to oxidation reduces the developing ability, and the photosensitive layer in the non-image area of the printing plate may not be completely dissolved even after processing. On the other hand, due to an excessive amount of developer replenishment or a rise in bath temperature due to a rise in temperature, the developing ability may exceed the specified limit, causing the image area of the printing plate to be eroded or the halftone dots to disappear. There are cases. For this reason, photosensitive lithographic printing plates can be developed with a wide range of developability similar to that when processed with a standard developer, even with a developer with a low processing capacity or a developer with a processing capacity higher than the standard. It is desired to have tolerance. (Hereinafter, the permissible range of decrease in developing ability that can provide appropriate development results is referred to as under-developability, and the permissible range of increase in development power that provides appropriate development results is referred to as over-developability.)Means for solving the above problems For example, JP-A-59-121044 describes the addition of an amphoteric surfactant and an organoboron surfactant to improve sensitivity and development tolerance, but it is not possible to improve the above-mentioned problems. had no effect.

Furthermore, Japanese Patent Application Laid-Open No. 62-251740 and USP3
B68254 discloses that the development tolerance is improved by adding a specific nonionic surfactant, but sensitivity and safelight properties are still insufficient. Further, it has the disadvantage that the developing solution foams during the development process.

Therefore, there has been a desire for a photosensitive composition and a photosensitive lithographic printing plate that are suitable for a photosensitive lithographic printing plate that has good sensitivity and less foaming of a developer without impairing safelight properties and development tolerance.

[Means for Solving the Problems] As a result of various studies in view of the problems of the prior art as described above, the present inventors have developed an excellent photosensitivity solution that solves the above problems by using a specific compound in combination. The present invention was achieved by learning that a composition and a photosensitive lithographic printing plate can be obtained.

That is, the gist of the present invention is to provide a group consisting of (a) an 0-naphthoquinone cyacyto compound, (b) an alkali-soluble resin, and (c) a polyoxypropylene alkyl ether, a polyoxypropylene alkylphenyl ether, and a polyoxypropylene alkyl ester. and a photosensitive lithographic printing plate having this photosensitive composition on a support.

The present invention will be explained in detail below.

The 0-naphthoquinone cyacyto compound in the present invention is O
The compound is not particularly limited as long as it contains the structure of -naphthoquinone thiacyto and satisfies the spirit of the present invention, for example, O
Examples include ester compounds of naphthoquinone cyasitosulfonic acid, a phenol which may be substituted with a methyl group, and a polycondensation resin of an aldehyde or ketone.

Examples of phenols include monohydric phenols such as phenol, 0-cresol, m-cresol, p-cresol, 3,5-xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, pyrogallol, Examples include trihydric phenols such as phloroglucin. The aldehyde includes formaldehyde, benzaldehyde, acetaldehyde,
Examples include crotonaldehyde and furfural. Preferred among these are formaldehyde and benzaldehyde. Further, examples of the ketone include acetone, methyl ethyl ketone, and the like.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, m-cresol/formaldehyde resin, m-, p-mixed cresol/formaldehyde resin, resorcinol/benzaldehyde resin, pyrogallol/acetone resin, and the like. The weight average molecular weight Mw of the polycondensation resin is preferably 5.0x102 to 5.0x102. Ox
10', more preferably 8. OX1
02~3002~30roXtOkoru.

The condensation rate of 0-naphthoquinone cyacytosulfonic acid with respect to the OH group of the phenol of the 0-naphthoquinonediaside compound (reaction rate with respect to one OH group) is 15 to 802
is preferable, and more preferably 20 to 452.

Furthermore, as the 0-naphthoquinone cyacyto compound used in the present invention, not only resins but also the following compounds described in JP-A-58-4345 can be used. That is,
For example, known 12-naphthoquinone cyacyto compounds such as 1,2-naphthoquinone cyacytosulfonic acid ester, 1,2-naphthoquinone cyacytosulfonic acid amide, and more specifically, ``Light'' by J. Kosar Sensitive System J (”Light-3
339-35
2 pages (1965), published by John Wiley & Sons (New York) and Duplicate Nis de 4-”7 Rust (W, S.
, De Forest) “Photoresist 4 (
“Photoresist”) Volume 50 (1975)
1,2-naphthoquinone cyato-5-sulfonic acid cyclohexyl ester, l-(1,
2-naphthoquinone cyacito-5-sulfonyl)-3,5
-dimethyl and lazole, 1,2-naphthoquinone cyacyto-5-sulfonic acid-4''-hydroxydiphenyl-4''
-azo-β-naphthol ester, N,N-di(1,
2-naphthoquinonecyasito-5-sulfonyl)-aniline, 2'-(1,2-naphthoquinonediazide-5-sulfonyloxy)-1-hydroxy-anthraquinone,
1.2-naphthoquinone cyacito-5-sulfonic acid-2,
4-dihydroxybenzophenone ester, 1,2-naphthoquinone cyato-5-sulfonic acid-2,3,4-trihydroxybenzophenone ester, 2 moles of 1,2-naphthoquinone cyato-5-sulfonic acid chloride and 4°4' - condensate of 1 mol of diaminobenzophenone, 1.2
- Condensate of 2 moles of naphthoquinone cyato-5-sulfonic acid chloride and 1 mole of 4,4'-dihydroxy-1°1'-diphenylsulfone, l.

2-naphthoquinone cyacito-5-sulfonic acid chloride 1
Examples include 1,2-quinonediazide compounds such as a condensate of 1 mole of purpurogallin and 12-naphthoquinone cyacyto-5-(N-dihydroabiethyl)-sulfonamide.

Also, Special Publications No. 37-1953, No. 37-3627, No. 37-13109, No. 40-26126, No. 40-
No. 3801, No. 45-5604, No. 45-27345
12-naphthoquinone cyasito compounds described in Japanese Patent Application Laid-open No. 1986-13013, Japanese Patent Application Laid-open No. 48-96575, Japanese Patent Application Publication No. 48-63802, and Japanese Patent Application Publication No. 48-63802 can also be mentioned.

As the 0-naphthoquinone cyacyto compound of the present invention, each of the above compounds may be used alone, or two or more thereof may be used in combination.

The proportion of the 0-naphthoquinone cyacyto compound used in the present invention in the photosensitive composition is preferably 5 to 60 g/2, particularly preferably 10 to 50 g/2.

Further, the alkali-soluble resin in the present invention may be any resin that can be used mainly as a binder, but preferred examples include novolak resin, vinyl polymer resin, and combinations thereof.

Examples of the novolak resin include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin as described in JP-A-55-57841, and JP-A-55-127553. Examples include copolycondensate resins of p-substituted phenol and phenol or cresol and formaldehyde, as described in .

The molecular weight of the novolac resin is preferably a number average molecular weight (hereinafter abbreviated as rMnJ) of 3.00×10” to 7.
．． 50x 103. Weight average molecular weight (hereinafter abbreviated as "MW") is 1.00x 10' to 3.00x 10'
, more preferably Mn is s, oox 1G2 to 4.00
x 10', Mw is 100x 1G'~2.00x
10'. Note that in the measurement of molecular weight in the present invention, Mn
and Mw were carried out by the method described in Synthesis Example 1 in the Examples below.

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

The vinyl polymer resin is preferably a polymer having a unit having a phenolic hydroxyl group in its molecular structure,
More preferred are polymers containing at least one structural unit of the following general formulas (A) to (D).

General formula (A) →CR4Rs CR&→- CONR, -GA)-B OH General formula (B) -(cRn Rs CR&+COO-+A)-, B-OH General formula (c) (cR4Rs Cnb"H-0H General formula (D) OH In the formula, n48 and Rs each represent a hydrogen atom, an alkyl group or a carboxyl group, preferably a hydrogen atom,
R6 represents a hydrogen atom, a halogen atom, or an alkyl group, preferably a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R7 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably an aryl group. A represents an alkylene group that may have a substituent that connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer from 0 to 1O, and B represents a phenylene group that may have a substituent. Represents a naphthylene group which may have a group or a substituent.

The polymer of the present invention preferably has a copolymer-type structure, and examples of monomer units that can be used in combination with the structural units represented by the above general formulas (A) to (D) include ethylene, Ethylenically unsaturated olefins such as propylene, isobutylene, butadiene, and isoprene; Styrenes such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene; acrylic acid,
Acrylic acids such as methacrylic acid: unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid, and maleic anhydride; methyl diacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate , phenyl acrylate, α-
Esters of α-methylene aliphatic monocarboxylic acids such as methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, and ethyl ethacrylate: acrylic nitrile,
Nitriles such as methacrylonitrile; Amides such as acrylamide; Anilides such as niacrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide: vinyl acetate, vinyl propionate, vinyl benzoate, acetic acid Vinyl esters such as vinyl; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, β-chloroethyl vinyl ether; vinyl chloride; vinylidene chloride: vinylidene cyanide: l-methyl-1-methoxyethylene, l.

l-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene 1-methyl-
Ethylene derivatives such as 1-nitroethylene; N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolene, and N-vinylpyrrolidone; other vinyl monomers can be mentioned.

These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above monomers, aliphatic monocarboxylic acid esters and nitriles exhibit excellent performance for the purpose of the present invention and are therefore preferred.

These monomers may be bound in the polymer of the present invention in either a block or random manner.

Typical specific examples of the vinyl polymer of the present invention are listed below. In addition, in the compounds shown below, s, k, l
, ■ and n each represent mol% of the structural unit.

One + CH.

CH.

CHs H, -C÷1- (Mw-280DO, My/Mn -7,8゜m +
n -40:60) C11°CHs -+cHm CCIIt CHHh--HCHm
CH=CH2 COOCHHs (Mw -20000, My/M n -2, 1゜m
:n:l:k-30;30:36.5:3
．． 5) l4s −+CH, −CC11t −(/)−11−1→CHt
CH) “(Mw”22000. Mw/Mn −
6,9゜m + n: l -3f14 (h3G) (
d) CHs tts (d CHs CHx
CHsξ m-(cHs CC11z CH ``---1→C1
(, -Cthe-(Mw-330[)0.Irl+v/
Mn=3.1゜m:n:l-2(h35+45) (e) CHs C11
3-+CHt CC11z Chr--1→CIb
C+1 toy-tatami HCH* CHh--1→CH*-
CVCN COOH (My
-C00H(,Mw/Mn-7,9゜m:n:j!:Ni:β-21115;30+33:2)CH3 (Mw"33000.My/Mn-7゜m:
n : l -38:60+2)(f) C
H! C113-4CHt-C
CH! -Ci-----Child C11m-CH)r--+
CH* CCH
Mw-35000, Mw/Mn-3,5゜m: n
: 1-30:30:40) (Mw-40000, Mw
/Mn -3,5゜m: n: l -20:60
:20) C1 (3 Hs H5 cage (Mw=54000. Mw/Mn -8,2゜m
: n : l =20:40:40)(Mw=350
00. My/Mn-3,8゜m + n: l
-30:35:35) (k) CI(s (Mw-20000, MW/Mn”3.5°man cod 1
81) m:n-1:1) As the vinyl polymer used in the present invention, the above polymers may be used alone or in combination of two or more. Moreover, it can also be used in combination with other polymer compounds.

The novolak resin and vinyl polymer used in the present invention may be used alone or in combination. The proportion of the alkali-soluble resin in the photosensitive composition is suitably 5 to 95% by weight, preferably 20 to 90% by weight.

Next, the activator used in the present invention is at least one selected from the group consisting of polyoxypropylene alkyl ether, polyoxypropylene alkylphenyl ether, and polyoxypropylene alkyl ester, and specifically, for example, the following compounds. is suitable.

That is, examples of polyoxypropylene alkyl ether include polyoxypropylene lauryl ether, polyoxypropylene cetyl ether, polyoxypropylene alkyl ether, polyoxypropylene oleyl ether, etc., and examples of polyoxypropylene alkylphenyl ether include polyoxypropylene Octyl phenyl ether, polyoxypropylene nonylphenyl ether, polyoxypropylene oleyl ether,
Examples include polyoxypropylene octylphenyl ether, polyoxypropylene nonylphenyl ether, and polyoxypropylene alkyl esters include polyoxypropylene lauryl ester, polyoxypropylene cetyl ester, polyoxypropylene stearyl ester, and the like.

The above-mentioned activators may be used alone or in combination of two or more, and their proportion in the photosensitive composition is preferably 0.05 to 10% by weight, more preferably 0.05% to 10% by weight, based on the total composition. Selected from the range of 1 to 5 F4%.

The photosensitive composition of the present invention can be obtained from the above-mentioned components, but for example, when supplying the composition to a positive-working photosensitive lithographic printing plate, organic acids, fat-sensitizing agents, exposed visible images, etc. Imparting agents and dyes are commonly added.

The organic acid has a pKa value of 2 or more, preferably pKa
Values greater than or equal to 3 are used. In the case of an organic acid having a pKa value of less than 2, dye residue and chemical resistance tend to decrease. Note that the pKa value of the present invention is a value at 25°C.

Such an organic acid is not particularly limited as long as its pKa value satisfies the above conditions, and examples thereof include monocarboxylic acids and dicarboxylic acids.

Monocarboxylic acids include formic acid, acetic acid, propionic acid,
Aliphatic monocarboxylic acids such as acetic acid, isoacetic acid, pentanoic acid, hexane acid, heptanoic acid, and alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid.

Benzoic acid, o-, m-p-aminobenzoic acid, 0, m-,
p-hydroxybenzoic acid, o-, m-p-methoxybenzoic acid, o-, m-, p-methylbenzoic acid, 3.5-dihydroxybenzoic acid, phloroglycincarboxylic acid, gallic acid, 3.5-dimethyl Examples include aromatic monocarboxylic acids such as benzoic acid.

Dicarboxylic acids include saturated or unsaturated fats such as malonic acid, methylmalonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, superic acid, azelaic acid, sebacic acid, itaconic acid, and malic acid. Group dicarboxylic acids, tetrahydrophthalic acid, 1.1-cyclobutanedicarboxylic acid, 1.1-cyclopentanedicarboxylic acid, 1.3-cyclopentanedicarboxylic acid, l, l-
Examples include alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 1,3-cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid.

The proportion of the organic acid in the photosensitive composition is usually 0.
05 to 15% by weight is suitable, preferably o, i to 8
Weight%.

As the sensitizing agent, a resin consisting of a condensate of a substituted phenol and an aldehyde represented by the following general formula (I) and/or an 0-naphthoquinone cyacytosulfonic acid ester compound of the resin is usually used.

H (wherein R and R2 are each a hydrogen atom, an alkyl group, or a halogen atom, and R3 is an alkyl group or cycloalkyl J, ti) having a prime number of 2 or more. ) The above general formula (
In I), Ro and R2 each represent a hydrogen atom, an alkyl group (including those containing 1 to 3 carbon atoms; alkyl groups having 1 to 2 carbon atoms are particularly useful), or a halogen atom (fluorine, 11 carbon atoms). ! Chlorine and bromine are particularly preferred among chlorine, bromine, and iodine), and R1 is an alkyl group having 2 or more carbon atoms (preferably 15 or less carbon atoms, and an alkyl group having 3 to 8 carbon atoms is particularly useful. ) or cycloalkyl groups (including those containing 3 to 15 carbon atoms) are particularly useful.

) represents.

Examples of the substituted phenols include isopropylphenol, tert-butylphenol, tert-amylphenol, hexylphenol, tert-octylphenol, cyclohexylphenol, 3-methyl-4-chloro-5-tert-butylphenol, isopropylcresol, tert- butyl cresol,
tert-amyl cresol, hexyl cresol, t
These include ert-octyl cresol and cyclohexyl cresol, among which tert-octylphenol and tert-butylphenol are particularly preferred.

In addition, the above aldehydes can be condensed with substituted phenols to produce resins, such as formaldehyde,
benzaldehyde, acetaldehyde, acrolein,
Aliphatic and aromatic aldehydes such as crotonaldehyde and furfural, including those having 1 to 6 carbon atoms. Among them, formaldehyde and benzaldehyde are preferred.

Resins made of condensates of substituted phenols and aldehydes are usually synthesized by polycondensing a substituted phenol represented by the general formula (I) with an aldehyde in the presence of an acidic catalyst. The acidic catalysts used are inorganic acids and organic acids such as hydrochloric acid, oxalic acid, sulfuric acid, and phosphoric acid. 0.7 to 1.0 mol is used. As the reaction solvent, alcohols, acetone, water, tetrahydrofuran, etc. are used, and the reaction solvent is kept at a specified temperature (-5 to
120°C) for a predetermined period of time (3 to 48 hours), the mixture is heated under reduced pressure, washed with water and dehydrated, or frozen and precipitated to obtain a condensed resin as a reaction product.

In the present invention, this condensation resin is used as it is or as an 0-naphthoquinone cyacytosulfonic acid ester compound of the resin.

The ester compound is prepared by dissolving the condensed resin in a suitable solvent such as dioxane, adding 0-naphthoquinone cyacytosulfonic acid chloride, and heating and stirring to adjust the quench point of an alkali such as alkali carbonate. It is obtained by esterification by adding dropwise up to

In the esterified product, the condensation rate of 0-naphthoquinone cyatosulfonic acid chloride with respect to the hydroxyl group of the phenol (reaction rate % with respect to one hydroxyl group) is 5 to 80%.
is preferable, more preferably 20 to 70%, still more preferably 30 to 60%. The condensation rate is a value obtained by determining the content of sulfur atoms in the sulfonyl group by elemental analysis.

The amount of the fat-sensitizing agent in the photosensitive composition of the present invention is 0.0
It is preferably 5 to 15% by weight, particularly preferably 1 to 10% by weight.

The oil sensitizing agent of the present invention has a Mw, preferably 5.0×10
2 to s, ox to', more preferably 7. Ox 102~: range of 1.0 x 10. It is preferable that the Mn is in the range of 3.0 x l 2 to 2.5 x 10'', more preferably 4.0 x l O' to 2.5 x 10''.
The range is 2.0×to3.

As the exposure visible image imparting agent, a compound that generates an acid upon exposure is generally used, and as the dye, a compound that forms a salt with this acid is generally used.

As the compound that generates an acid upon exposure to light, a trihaloalkyl compound or a diazonium compound represented by the following general formula (II) or (m) is preferably used.

)1-N B (Xa is a trihaloalkyl group having 1 to 3 carbon atoms, W
is N, S, Se or p, z is O, N, SSe or P
, Y has a chromophore group and represents a group consisting of a group of nonmetallic atoms necessary to cyclize W and Z) Ar NtX-...... ■(Ar is an aryl group, (X represents a counter ion of an inorganic compound) Specifically, for example, the trihaloalkyl compound of formula II includes compounds represented by the following general formulas (1), (2), and (2).

Xa (wherein, Xa is a trihaloalkyl group having 1 to 3 carbon atoms, B is hydrogen or a methyl group, A is a substituted or unsubstituted aryl group or a heterocyclic group, and 11 is 0, l
or 2) As exemplary compounds, oxadiazole compounds having a benzofuran ring as represented by the general formula (1), JP-A-54
Examples thereof include 2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole compound described in JP-A-74728.

In addition, as compounds of general formulas ① and ②, JP-A-53-3
4-(2,4-dimethoxy-4-styryl)-6-dolichloromethyl-2-pyrone compound, 2,4-bis-(trichloromethyl)-6 described in Publication No. 6223
-p-methoxystyryl-5-triazine compound, 2.
Examples include 4-bis-(trichloromethyl)-6-p-dimethylaminostyryl-5-) riazine compound.

The diazonium salt compound is preferably a diazonium salt that generates a strong Lewis acid upon exposure to light, and a counter ion of an inorganic compound is recommended as the counter ion part.

As a specific example, the anion part of the diazonium salt is
An aromatic diazonium salt that is at least one of phosphorus ion, arsenic fluoride, antimony fluoride ion, antimony chloride ion, tin chloride ion, bismuth chloride ion, and zinc chloride ion, preferably paradiazophenylamine salt. .

The amount of the exposure visible image imparting agent contained in the total photosensitive composition is preferably 0. Old ~ ZO weight%, more preferably 0
．． 1 to 20% by weight, in particular 0.2 to 10% by weight.

On the other hand, as the dye, any generally known compound that forms a salt with an acid can be used, and examples thereof include triphenylmethane dyes, cyanine dyes, diazo dyes, styryl dyes, and the like. Specifically, Victoria Pure Blue 80, Ethyl Violet, Crystal Violet, Friliant Clean, Pesic Fuchsin, Eosin, Phenolphthalein, Xylenol Blue, Congo Red, Malachite Green, Oil Blue #603, Oil Pink #312, Cresol Red. , auramine, 4-p-diethylaminophenylimino naphthoquinone, leucomalachite green, leuco crystal violet, and the like. The amount of this dye added is preferably about 0.01 to IO% by weight, more preferably 0.05 to 8% by weight of the total photosensitive composition.

The above-mentioned photosensitive composition is a paint dissolved in various solvents, such as cellosolves such as methyl (ethyl) cellosolve and methyl (ethyl) cellosolve acetate, coating solvents such as dimethyl formamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, and trichloroethylene. It is formed by coating and drying it on a grained and anodized aluminum plate support as described below.

When using the positive-working photosensitive lithographic printing plate thus obtained, a known method is applied, in which a positive-working film is brought into close contact with the plate, exposed to light using an ultra-high pressure mercury lamp, a metal halide lamp, etc.
It is developed with an alkaline aqueous solution such as sodium metasilicate, potassium metasilicate, sodium phosphate, or sodium hydroxide, and then supplied as a printing plate. Burning treatment is also applied if necessary. The lithographic printing plates produced in this manner are used in sheet-fed and off-wheel printing presses.

In the present invention, the support on which the photosensitive layer using the above-described photosensitive composition is provided is an aluminum plate.

When an aluminum plate is used as a support, surface treatments such as graining, anodizing, and, if necessary, sealing are performed. Known methods can be applied to these treatments.

Examples of methods for grain pattern treatment include mechanical methods and electrolytic etching methods. 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. A preferred method is electrolytic etching.

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 sand grain treatment, if necessary, a desmut treatment is performed using an aqueous alkali or acid solution to neutralize the material, 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 amount of the anodic oxide film formed is suitably 1 to 50 mg/da'', preferably 1 g/dII2 at 10 to 40°C. 85χ liquid: 35I 1 sentence, chromium oxide (Vl): prepared by dissolving 20g in 1!L of water)
It is determined by measuring the weight change before and after the aluminum plate is immersed in water to dissolve the oxide film and after the film is dissolved.

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

[Examples] Hereinafter, the photosensitive composition and photosensitive lithographic printing plate of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples (synthesis of photoreceptor) Synthesis Example 1 (Synthesis of QD-2) The mixture was placed in a three-headed colben set in a pyrogalloo router bath, nitrogen gas was blown in to perform nitrogen substitution, and then 5 g of phosphorus oxychloride was added to perform a polycondensation reaction.

The reaction temperature was maintained at 20°C, and after reacting day and night, wood 1
The resulting polycondensate was gradually added to the solution under strong stirring to precipitate the resulting polycondensate.

The precipitated resin was collected by filtration and washed with water until the pH became approximately neutral (7), and the cancer residue was dried at 40'C or lower. In this way, 50 g of light brown resin was obtained.

The molecular weight of this resin was determined by gel permeation chromatography [Hitachi Model 635, column Shodex].
dex) A804, A803, A302 in series)
Mn, M was measured using a polystyrene standard at
The calculation of w was carried out by the method described in Takue et al., Journal of the Chemical Society of Japan, 1972 (April issue), p. 800, by smoothing the peaks of the oligomer region (connecting the centers of the peaks and valleys). As a result, Mn is 2.00x 10', M
w was 3.40x103.

Next, 60 g of this resin was dissolved in 720 ml of dioxane, 70 g of 1,2-naphthoquinone cyacito-5 sulfonyl chloride was added, and after dissolving, 60 g of an aqueous potassium carbonate solution (13% by weight) was added dropwise, and 40 to After carrying out the linear combination reaction at 50°C for about 1 hour, the reaction solution was poured into a large amount of diluted hydrochloric acid (salt production?! i1i1 3 m, water 3 m), and the precipitated resin was collected by filtration and dried. As a result, pyrogallol
1 of acetone resin.

2-naphthoquinone cyasito-5-sulfonic acid ester 5
6 g of yellow powder resin was obtained. As a result of analysis, the condensation rate of OH groups was 20%. When the molecular weight of the ester was measured in the same way as polyhydroxy resin, Mn was 2.30.
x 10'', Mw was 3.0:IX 10'.

(Synthesis of binder) Synthesis Example 2 (corresponding to (b) above) 400 g of p-hydroxyaniline, 4 g of hydroquinone monomethyl ether, 4 grams of acetone, and 36 grams of pyridine.
0g of methacrylic acid chloride was mixed, cooled from the outside using a cryogen, and when the internal temperature had dropped to 110℃, methacrylic acid chloride 4
20g was added dropwise while stirring. Adjust the dropping temperature so that the reaction temperature is below O'C, and after the completion of the dropwise addition, stir at O~3°C for about 2 hours, then stir at 25°C for 2 hours, and then reduce the reaction solution to 1/3. Narumate'c1i! Add this to dilute hydrochloric acid (pH
The resulting precipitate was suction filtered to obtain a white solid. Dissolve this white solid in 2 parts of methanol with heating, and then add 24 parts of 5% sodium carbonate aqueous solution.
, and stirred at 40°C for 30 minutes. This dark-spot colored solution was then poured into 5% aqueous hydrochloric acid solution BfL to form a large amount of precipitate, which was filtered with suction and dried to obtain a pale pink solid. This was recrystallized from a mixed solvent of ethanol and water to obtain 450 g of colorless needle-like crystals of p-hydroxymethacrylanilide having a melting point of 155-156°C.

The obtained p-hydroxymethacrylanilide (HyP
MA) 53.2g, acrylonitrile (AN) 15.9
g, 36.5 g of methyl methacrylate (MMA), 3.5 g of ethyl acrylate (EA) and 0.82 g of α・α-azobisisobutyronitrile in 190 m of a mixed solvent of acetone:ethanol (l:2). After dissolving and purging with nitrogen gas, a polymer solution was obtained by heating at 65°C. This polymer solution was poured into 3 portions of a 5% HC droplet aqueous solution, and the resulting white precipitate was filtered and dried to obtain 70 g of a white polymer. When the molecular weight was measured, Mn was 9.5.
X 10' and Mw were 2.0xlO'.

Synthesis Example 3 (corresponding to (c) above) 53.2 g of p-hydroxymethacrylanilide (HyPMA) obtained in Synthesis Example 2, acrylonitrile (AN
) 15.9g, methyl methacrylate (MMA) 40.
0g and α・α-azobisisobutyronitrile 0.
After dissolving 82 g in 190 ml of a mixed solvent of acetone:ethanol (1:2) and purging with nitrogen gas,
Upon heating at 0.degree. C., a polymer solution was obtained. This polymer solution was poured into three portions of a 5% HCI aqueous solution, and the white precipitate formed was filtered and dried to obtain 70 g of a white polymer.

When the molecular weight was measured, Mn was: 3.2 x 103. M
w was 2.2xlO'.

Synthesis Example 4 (corresponding to (sentence) above) 40.0 g of p-hydroxystyrene, 20.0 g of acrylonitrile, 40 g of styrene, and 1. (α・α′−
Azobisisobutyronitrile with acetone; ethanol (
A polymer solution was obtained by dissolving in 600 m of a mixed solvent of 1:l), purging with nitrogen gas, and heating at 68°C for 10 hours. This was poured into 5 drops of water, and the resulting white precipitate was filtered and dried to obtain 70 g of a polymer. Mw of this polymer
was 47,000.

Synthesis Example 5 90 g of m-cresol, 56 g of p-cresol, 54 g of phenol, 85 g of a 37% aqueous formaldehyde solution, and 2.5 g of oxalic acid were placed in a three-headed colben set in an oil bath, and the temperature was raised while stirring. It foamed violently at around 90°C, and after being temporarily cooled, the temperature was raised again to bring the internal temperature to 105°C.

After reacting for about 3 hours, the temperature was further raised to 175°C, and water was distilled off.

After 2 hours, the temperature was raised to 200"C, and the pressure was reduced to 100 mmHg to distill off the residual monomer. After 10 minutes, the reaction was stopped.
The reaction product was poured into a Teflon vat and solidified. As a result of measuring the molecular weight of this resin, Mn was 1350 and Mw was 5400.

Synthesis Example 6 m-cresol of Synthesis Example 5 was mixed with 2,3-xylenol (l
Synthesis was carried out in the same manner except that the compound was changed to

As a result, Mn was 1400. Mw was 4800.

(Example, Comparative Example) After degreasing a 0.24 mm thick aluminum plate (material 1050, tempered H16) in a 5% aqueous sodium hydroxide solution at 60°C for 1 minute, 0°5 mol, 1 Electrolytic etching treatment was carried out in an aqueous hydrochloric acid solution at a temperature of 25° C., a current density of 60 A/dm, and a treatment time of 308'.

Then, in a 5% aqueous sodium hydroxide solution at 60°C,
After desmutting for 0 seconds, the temperature was 20°C and the density was 3A/dm2 in a 20% sulfuric acid solution. Processing time 1
Anodizing treatment was performed under conditions of 1 minute. Furthermore, 30°C
A hot water sealing treatment was performed using hot water for 20 seconds to produce an aluminum plate as a support for a printing plate material.

Preparation of photosensitive lithographic printing plate sample 1 A photosensitive composition coating liquid (1) having the following composition was coated on the aluminum plate prepared as above using a rotary coating machine.
．． Dry at 0°C for 4 minutes and prepare a positive photosensitive lithographic printing plate sample l.
I got it.

[Photosensitive composition coating liquid (1) composition] Novolak resin (polymer of Synthesis Example 5) 1-5 g
Vinyl polymer resin (polymer of Synthesis Example 2) 6.0g
1.2-naphthoquinone cyacito-5-sulfonic acid-2,
3,4-)-lyhydroxybenzophenone ester (Q
D-1) 2.5g activator (To-452
8) 0.2g organic acid (terephthalic acid) 0.1g sensitizing agent
0.1g (pt-octylphenol formaldehyde novolak resin (Mw
1:100) and 1,2-naphthoquinone cyato-5-sulfonyl chloride (condensation rate: 50%)) Exposure visible image imparting agent 0-
1g (2-trichloromethyl-5-(β-(2-penzofuryl)vinyl)1,3.4-oxadiazole) Dye (Victoria Pure Blue BOH manufactured by Hojogaya Chemical) 0.1g Methyl Cellosol 100g Photosensitive Preparation of photosensitive lithographic printing plate samples 2 to 8 The photosensitive composition coating liquid (1) used in the preparation of photosensitive lithographic printing plate sample 1 contains novolac resin, vinyl thread ball combination resin, 0-quinonediazide compound, and activator. Photosensitive lithographic printing plate samples 2 to 8 were obtained in the same manner as in the preparation of sample 1, except that the types and amounts added were changed as shown in Table 1.

A step tablet for sensitivity measurement (N002 manufactured by Eastman Kodak Company, 21 gray scale levels with a density difference of 0.15 each) was attached to the thus obtained photosensitive lithographic printing plate samples 1 to 8-1, and 2KW metal halide was applied. lamp(
Idol fin 2000 manufactured by Iwasaki Electric Co., Ltd.) as a light source 8
．． Exposure was performed under the condition of 0 mW/cm2.

Next, 5DR-1 (manufactured by Konica ■) was developed at 27°C for 20 seconds with a developer diluted 6 times with water, and after washing with water, the number of clear steps of the gray scale printed on the plate was 4. The exposure time was investigated.

Next, in order to examine the under-developability, the above 5DR-1
A positive-working photosensitive lithographic printing plate that had been entirely exposed to a developer solution diluted 6 times was developed at a rate of 2.0 m' per 11 developer solutions.
After exhausting the developer, the positive type photosensitive lithographic printing plate with the positive original again exposed to light was developed under the same conditions as above.
The presence or absence of stains due to poor development was examined. In addition, the state of foaming of the developer at this time was observed.

Furthermore, in order to examine the resistance to over-development,
Development was performed for 90 seconds at 30° C. using a 6-fold dilution of DR-1 developer, and the image area, including the small dots of the halftone dots, was observed for discoloration (damage). The increase in the number of solid steps was determined compared to the number of solid steps in the 27° Cl2O second development process. The smaller the increase in the number of solid stages, the better the over-development resistance.

Furthermore, in order to evaluate the safelight property, this sample was left in a bright room for 10 minutes, 20 minutes, and 30 minutes to expose it to light, and a developer (standard developer) in which 5DR-1 was diluted by 6 parts with water was used.
The sample was developed at 25°C for 40 seconds, and the degree of erosion of the image area was evaluated by comparing it with that of a sample that had not been left in a bright room. The above results are shown in Table 2.

(Hereinafter referred to as margins) As is clear from Table 2, 1. The photosensitive lithographic printing plate of the present invention maintains safelight properties and development acceptability, does not cause foaming of the developer during development processing, and has excellent sensitivity. I understand.

[Effects of the Invention] As explained in detail above, according to the present invention, the sensitivity is excellent without impairing safelight properties and development tolerance, and furthermore, no foaming occurs in the developer during development processing. It is possible to provide a positive-working photosensitive lithographic printing plate and a photosensitive composition suitable as a photosensitive layer of the positive-working photosensitive lithographic printing plate.

Claims (2)

[Claims] (1) (a) o-naphthoquinonediazide compound, (b)
A photosensitive composition comprising an alkali-soluble resin and (c) at least one activator selected from the group consisting of polyoxypropylene alkyl ether, polyoxypropylene alkylphenyl ether, and polyoxypropylene alkyl ester. . (2) on the support: (a) an o-naphthoquinonediazide compound; (b) an alkali-soluble resin; A photosensitive lithographic printing plate characterized by having a photosensitive layer made of a photosensitive composition containing at least one selected activator.