JPH03259259A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To make improvement in reproducibility of dots by constituting the above printing plate of a specific ester compd., an alkaline-soluble novolak resin, a compd. which forms a halogen free group by irradiation with active rays, and a discoloring agent which changes the color tone of the decomposition product of this compd. by interacting therewith. CONSTITUTION:A photosensitive layer consisting of the photosensitive compsn. contg. at least the 1, 2-naphthoquinonediazide-4-sulfonate compd. of 2,3,4,3',4',5'- hexahydroxybenzophenone and/or 1, 2-naphthoquinonedizade-5-sulfonate compd., the alkaline-soluble novolak resin, the compd. which forms the halogen free group by irradiation with the active rays, and the discoloring agent which changes the color tone of the decomposition product of this compd. is provided on a base. The photosensitive planographic printing plate which has the excel lent reproducibility of the dots in printing and more particularly the reproducibility of the small dots, has wide development latitude in either of under-developability and over-developability and has the excellent exposing and visible image property is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive lithographic printing plate, and more particularly to a photosensitive lithographic printing plate using a novel photosensitive substance.

[Prior Art] Usually, the photosensitive layer of a positive photosensitive lithographic printing plate contains a quinonediazide compound as a photosensitive substance and an alkali-soluble resin as a component for increasing film strength and alkali solubility. . In particular, quinonediazide compounds have traditionally been used, such as cresol and
A combination of a compound having a repeating unit having an electron-donating group as a substituent, such as a novolac resin, a polycondensation resin of pyrogallol and acetone, and naphthoquinone diazide, or a poly or monohydroxy compound having no repeating unit (for example, 2. 3,4-trihydroxybenzophenone, p-cumylphenol, etc.) and naphthoquinone diazide, etc. are used.

However, in the case of photosensitive lithographic printing plates using photosensitive materials such as those mentioned above, if a low-density original film is printed during plate making, the reproducibility of halftone dots, especially small dots, is poor and the small dots disappear. As a result, there is a problem in that the reproducibility of highlighted areas becomes insufficient during printing. Furthermore, conventionally, the development of such positive photosensitive lithographic printing plates is usually carried out in a developer consisting of an aqueous alkaline solution, but the developing ability of the developer tends to fluctuate depending on various conditions. Developing ability decreases due to fatigue caused by the printing plate and deterioration due to air oxidation, 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 excessive replenishment of the developer or an increase in the bath temperature due to a rise in temperature, the developing capacity may exceed the specified limit, and the image area of the printing plate may be eroded or the halftone dots may disappear. There are cases. For this reason, photosensitive lithographic printing plates show the same developability as when processed with a standard developer, even with a developer with a lower processing capacity as described above, or with a developer with a higher processing capacity than the standard one. It is desired to have a wide range of development tolerance. (Hereinafter, the permissible range of development capacity decline that allows appropriate development results to be obtained is referred to as "under-developability," and the permissible range of development capacity increase that provides appropriate development results as "over-developability.")
That's what it means. 〉 [Problems to be Solved by the Invention] Accordingly, an object of the present invention is to provide a method that has excellent reproducibility of halftone dots during printing, particularly reproducibility of small dots, and has a wide development tolerance in both under-development and over-development. The object of the present invention is to provide a photosensitive lithographic printing plate which has high properties and excellent exposure and visible imageability.

[r! Means for Solving Problem R] In view of the above-mentioned problems, the present inventors have conducted intensive research and found that the above-mentioned object of the present invention has been achieved by applying at least (a) 2.3.
4. 1,2-naphthoquinonediazide-4-sulfonic acid ester compound and/or 1,2-naphthoquinonediazide-5-sulfonic acid ester compound of 3', 4', 5'-hexahydroxybenzophenone, (b) an alkali-soluble novolac resin, (c) a compound that generates a halogen Tl111 group upon irradiation with actinic rays, and (d)
(c) A color change agent that changes its color tone by interacting with the decomposition products of (c). .

The present invention will be explained in more detail below.

In the photosensitive lithographic printing plate of the present invention, a 1,2-naphthoquinonediazide-4-sulfonic acid ester compound of 2,3,4.3',4'5'-hexahydroxybenzophenone used as a photosensitive substance and/or or 1,2-naphthoquinonediazide-5-sulfonic acid ester compound (
Hereinafter, the ester compound of the present invention is an ester compound having a degree of esterification of 90% or more and having a structure represented by the following general formula [A].

1,2-naphthoquinone diazido-5-sulfonic acid ester of 3', 4', 5'-hexahydroxybenzophenone is preferably used.

The above ester compound of the present invention includes 2,3.4.3'4'5' -hexahydroxybenzophenone and 1,2-naphthoquinonediazide-5-sulfonyl chloride or 1,2 It can be easily synthesized by condensing -naphthoquinonediazide-4-sulfonyl chloride or a mixture thereof.

In the formula, R may be the same or different, and each represents a hydrogen atom,
Represents a 1,2-naphthoquinonediazide-4-sulfonyl group or a 1,2-naphthoquinonediazide-5-sulfonyl group (provided that -90% or more of R in formula [A] is 1,2
-naphthoquinonediazide-4-sulfonyl group and/or 1,2-naphthoquinonediazide-5-sulfonyl group).

Among the ester compounds of the present invention, 2,3.4゜2,3゜4.3', 4' represented by formula [B] used here
, 5'-hexahydroxybenzophenone is H,
31 Euler et al.'s method [J, Chem.

Soc, 109 (1916)].

Compound of formula [8] and 1,2-naphthoquinonediazide-5
For the esterification reaction with -sulfonyl chloride or 1,2-nafdoquinonediazide-4-sulfonyl chloride, a conventional method can be used.

That is, a predetermined amount of hexahydroxybenzophenone represented by formula [B] and 1,2-naphthoquinonediazide-5-
Sulfonyl chloride or 1.2=naphthoquinone diazide-4-sulfonyl chloride and a solvent such as dioxane, acetone, methyl ethyl ketone, N-methylpyrrolidone, etc. are charged into a flask, and a basic catalyst such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, Add triethylamine etc. dropwise to condense. The obtained product is purified and dried after washing with water. By the above method, the general formula [A
] can be prepared.

The above ester compound of the present invention is contained in the photosensitive layer in an amount of 5 to 70% by weight.
, preferably in an amount ranging from 10 to 50% by weight.

Further, examples of the alkali-soluble novolak resin used in the present invention include resins obtained by condensing phenols and formaldehyde in the presence of an acid catalyst. Examples of the phenols include phenol, 0-cresol,
-monocresol, p-cresol, 3.5-xylenol, 2.4-xylenol, 2.5-xylenol, carvacrol, thymol, catechol, resorcinol, hydroquinone, pyrogallol, phloroglucin, and the like. The above phenolic compounds can be used alone or in combination with formaldehyde to obtain a resin. Among these, preferred novolak resins include phenol, 0-cresol (or 0-cresol) and p-cresol.
- A resin obtained by copolycondensing at least one selected from cresol and formaldehyde, for example,
Phenol/formaldehyde resin, -cresol/
Formaldehyde resin, 0-cresol/formaldehyde resin, phenol/p-cresol/formaldehyde copolymer resin, amount-cresol/p-cresol/
Formaldehyde copolycondensate resin, 0-cresol/p
-Cresol/formaldehyde copolycondensate resin, phenol/mountain -Cresol/p-cresol/formaldehyde copolycondensate resin, phenol/0-talesol/
Examples include p-cresol/formaldehyde copolycondensate resin. Furthermore, among the above-mentioned novolac resins, phenol/m-cresol/p-cresol/formaldehyde resins are preferred.

In the present invention, the above novolac resins may be used alone or in combination of two or more.

The molecular weight of the above novolac resin (polystyrene standard) is I! average molecular weight 11MW is 2.0 x 103 to 2.0
×104, and the number average molecular weight Mn is 7.0XiQ2 to 5.
Preferably, the value is within the range of 0x103, and further,
Preferably, Mw is 3.0×103 to 6.0×103,
Mn is a value within the range of 7.7×10 2 to 1.2×10 3 . The molecular weight of the novolak resin in the present invention is measured by GPC (gel permeation chromatography).

The alkali-soluble novolac resin is contained in the photosensitive composition in an amount of 30 to 95% by weight, preferably 50 to 90% by weight.

In the present invention, halogen release 11 is achieved by irradiation with actinic light.
As compounds that generate groups, the following formulas [I] and [
A trihaloalkyl compound or a diazonium salt compound represented by II] is preferably used.

General formula [I] <In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, W represents each atom of N, S, Se SP, and C, and 2 represents O, N, S, Se Each atom of 1P is shown. Y has a chromophore group and represents a nonmetallic atomic group necessary for cyclizing W and Z. However, the ring formed by the nonmetallic atom group may have the above-mentioned Xa. ) General formula [II] Ar -N2 The following general formula [I[[], [rV] or [
V].

Specifically, as a compound represented by the general formula [1111% formula % general formula [I[1]], general formula [IV] general formula [V] a (wherein a has 1 to 3 carbon atoms) trihaloalkyl group, L is a hydrogen atom or a methyl group, - is a substituted or non-W1 substituted aryl group or an oxadiazole having a benzofuran ring such as a heterocyclic group
The following compound described in Publication No.-74728: Compound, Weight II! ? 2-trichloromethyl-5-(p-methoxystyryl)-1゜3゜4-oxadiazole compound described in JP-A No. 54-74728, or the following compound described in JP-A-60-241049: The following compound described in JP-A-55-77742: The following compound described in JP-A-60-3626: 'r'f I
JIT Showeo-177340+ public 'In description f)
The following compounds include the following compounds described in JP-A-61-143748.

Further, as the compound represented by formula [IV] or [V], specifically, 4-(2,4-dimethoxy-4-styryl)-6 described in JP-A No. 53-36223 -Dolichloromethyl-2-pyrone compound, 2,4-bis=(trichloromethyl)-6-p-methoxystyryl- described in JP-A-48-36281
Examples thereof include 6-triazine compound, 2<4>-bis-(trichloromethyl)-6-p-dimethylaminostyryl-5-t-lyazine compound, and the like.

On the other hand, 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 specific examples of such compounds, the anion moiety of the diazonium salt is at least one of phosphorus fluoride ion, arsenic fluoride ion, antimony fluoride ion, antimony chloride ion, tin chloride ion, bismuth chloride ion, and zinc chloride ion. Examples include aromatic diazonium salts, and preferably bala diazophenylamine salts.

The amount of the compound that generates halogen free radicals upon irradiation with actinic rays contained in the total photosensitive layer is 0.01 to 20% by weight.
is preferable, more preferably 0.1 to 20% by weight, particularly preferably 0.2 to 10% by weight.

The photosensitive lithographic printing plate of the present invention preferably contains a color-changing agent that changes the color tone by interacting with the photodecomposition product, together with a compound that generates halogen free radicals upon irradiation with actinic rays. . There are two types of such color changing agents: those that develop color and those that fade or change color. As the color-changing agent that causes fading or discoloration, various dyes such as diphenylmethane, triphenylmethane-based thiazine, oxazine-based, xanthine-based, anthraquinone-based, iminonaphthoquinone-based, and azomethine-based dyes are effectively used.

Specific examples of these include the following: Brilliant Green, Eosin, Ethyl Violet, Erythrosin B1 Methyl Green, Crystal Violet, Pesic Tsuksin, Phenolphthalein, 1,3-Diphenyltriazine, Alizarin Red S1 Thymolphthalein, Methyl Violet 2B,
Quinaldine Red, Rose Bengal, Methanil Yellow Thymol Sulfophthalein, Xylenol Blue Methyl Orange, Orange IV, Diphenylthiocarbazone, 2,7-Dichlorofluorescein, Paramethyl Red, Congo Red, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue-28, Nile Blue A1 Phenacetaline, Methyl Violet, Malachite Green,
Paratuxin, Victoria Pure Blue 80 mouths (manufactured by Odugaya Chemical ■), Oil Blue #603 [manufactured by Orient Chemical Industry ■], Oil Pink #312 [manufactured by Orient Chemical Industry ■], Oil Red 5B [manufactured by Orient Chemical Industry ■], Oil Blue Let #308 [manufactured by Orient Chemical Industry ■], Oil Red OG [manufactured by Orient Chemical Industry ■]
, Oil Red RR [manufactured by Orient Chemical Industry ■], Oil Green #502 [manufactured by Orient Chemical Industry ■,
Subiron Red BE Rospecial [manufactured by Hodogaya Chemical Industry ■], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, fast acid violet R1 sulforhodamine B1 auramine, 4-p-diethylaminophenyl imino naphthoquinone, 2-carboxyanilino- 4-1)-Diethylaminophenylimino naphthoquinone, 2-carbostearylamino-4-1
)-dihydroxyethylamino-phenylimino naphthoquinone, p-methoxybenzoyl-p'-diethylamine-〇'-methylphenyliminoacetanilide, cyano-p-diethylaminophenyliminoacetanilide, 1-phenyl-3-methyl-4-p- Diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone.

Moreover, arylamines can be mentioned as color-changing agents that develop color. Arylamines suitable for this purpose include not only simple arylamines such as primary and secondary aromatic amines, but also so-called leuco dyes, examples of which include the following.

Diphenylamine, dibenzylaniline, triphenylamine, diethylaniline, diphenyl-〇-phenylenediamine, p-toluidine, 4゜4'-biphenyldiamine, 0-chloroaniline, 0-bromoaniline, 4
-chloro-〇-phenylenediamine, 0-bromo-N,
N-dimethylaniline, 1.2.3-t-rephenylguanidine, naphthylamine, diaminodiphenylmethane, aniline, 2.5-dichloroaniline, N-methyldiphenylamine, 0-toluidine, p,p'-tetramethyldiaminodiphenylmethane, N,N dimethyl-p
-phenylenediamine, 1,2-dianilinoethylene,
p,p',p''-hexamethyltriaminotriphenylmethane, p,p'-tetramethyldiaminotriphenylmethane, p.

p'-tetramethyldiaminodiphenylmethylimine,
p, p', p''-triamino-0-methyltriphenylmethane, p, p', p''-triaminotriphenylcarbinol, p, p'-tetramethylaminodiphenyl-4-anilinonaphthylmethane, p ,
p', p''-triaminotriphenylmethane,
p, p', p''-hexapropyltriaminotriphenylmethane.

In the present invention, among the above-mentioned color change agents, dyes that can change color in the nine regions 1 to 5 are preferred.

The proportion of the above-mentioned color change agent in the photosensitive layer of the photosensitive lithographic printing plate is preferably 0.01 to 10% by weight, more preferably 0.02 to 5% by weight.

In addition to the above-mentioned compounds, the photosensitive lithographic printing plate of the present invention contains:
If necessary, it may contain an acid and/or an acid anhydride; All known various organic acids can be used as the I acid, but organic acids with a pKa value of 2 or more are preferred, and more preferably organic acids with a pKa value of 3.0 to 3.0.
9.0, particularly preferably 3.5 to 8.0 ms
is used. However, the pKa value used in the present invention is 2
This is the value at 5°C.

Examples of such autata include all compounds that can exhibit the above pKa value as described in Kagaku Binran Basic Edition 2 (Maruzen Q 11966, pp. 1054-1058). Examples of such compounds include benzoic acid, adipic acid, azelaic acid, isophthalic acid, p-toluic acid, q-toluic acid, and β-toluic acid.
-Ethylglutaric acid, m-oxybenzoic acid, p-oxybenzoic acid, 3,5-dimethylbenzoic acid, 3,4-dimethoxybenzoic acid, glyceric acid, glutaconic acid, glutaric acid, p-anisic acid, succinic acid, sebacin acid, β, β-diethylglutaric acid, 1,1-cyclobutanedicarboxylic acid,
1,3-cyclobutanedicarboxylic acid, 1゜1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, β, β-
Dimethylglutaric acid, α-tartaric acid, superric acid, terephthalic acid, pimelic acid, phthalic acid, fumaric acid, β-propylglutaric acid, propylmalonic acid, mandelic acid, mesotartaric acid, β-methylglutaric acid, β, β −
Methylpropylglutaric acid, methylmalonic acid, malic acid, 1.1-cyclohexanedicarboxylic acid, 1.2-cyclohexanedicarboxylic acid, 1.3-cyclohexanedicarboxylic acid, 1.4-cyclohexanedicarboxylic acid, cis-4-cyclohexene- Examples include 1,2-dicarboxylic acid, erucic acid, undecenoic acid, lauric acid, n-capric acid, pelargonic acid, and n-undecanoic acid.

Other organic acids having an enol structure such as Meldrum's acid and ascorbic acid can also be preferably used. The proportion of the organic acid in the photosensitive layer is 0.05 to 10% by weight.
is suitable, preferably 0.1 to 5% by weight.

Further, as the acid anhydride used in the present invention, all known various acid anhydrides can be used, but cyclic acid anhydrides are preferable, such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc. phthalic acid,
3.6-Nindooxy-ΔImichi Tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, glutaric anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic acid, and the like. These acid anhydrides are preferably contained in the photosensitive layer in an amount of 0.05 to 10% by weight, particularly 0.1 to 5% by weight.

The photosensitive lithographic printing plate of the present invention preferably has the following formula [
VI] containing a synthetic resin of substituted phenols and aldehydes and/or an 0-naphthoquinonediazide sulfonic acid ester compound of the resin.

General formula [v1] (In the formula, R5 and R6 each represent a hydrogen atom, an alkyl group, or a halogen atom, and R7 represents an alkyl group or a cycloalkyl group having 2 or more carbon atoms.) In the substituted phenols represented, R5 and R6 are a hydrogen atom, an alkyl group (1
It includes those containing from 3 to 3 carbon atoms. C1 -C2 alkyl groups are particularly useful. > or halogen atom (among fluorine, chlorine, bromine and iodine atoms, chlorine atom and bromine atom are particularly preferred). ], and R7 represents an alkyl group having 2 or more carbon atoms (preferably 15 or less carbon atoms; alkyl groups having 3 to 8 carbon atoms are particularly useful) or a cycloalkyl group (3 to 15 carbon atoms). Cycloalkyl groups containing 3 to 8 carbon atoms are particularly useful.

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, t
ert-amyl cresol, hexyl cresol, te
Examples thereof include rt-octyl cresol and cyclohexyl cresol, among which tert-octylphenol and tert-butylphenol are particularly preferred.

Further, examples of the aldehydes include aliphatic and aromatic aldehydes such as formaldehyde, benzaldehyde, acetaldehyde, acrolein, crotonaldehyde, and fulmethyl, including those having 1 to 6 carbon atoms. Among them, formaldehyde and benzaldehyde are preferred.

The resin obtained by condensing the substituted phenols and aldehydes comprises - a substituted phenol represented by formula [VI];
It is synthesized by polycondensation with aldehydes in the presence of an acidic catalyst. Acidic catalysts used include hydrochloric acid, oxalic acid,
Inorganic acids and organic acids such as sulfuric acid and phosphoric acid are used, and the blending ratio of substituted phenols and aldehydes is 0.7 to 1.0 parts by mole per 1 part by mole of substituted phenols. Alcohols, acetone, water, tetrahydrofuran, etc. are used as the reaction solvent.

After reaction at a specified temperature (-5 to 120°C) for a specified period of time (3 to 48 hours), it can be obtained by heating under reduced pressure, washing with water and dehydrating it, or
Alternatively, the reactant can be obtained by precipitating water.

O of the polymer resin of the above substituted phenols and aldehydes
-The naphthoquinonediazide sulfonic acid ester compound is
Esterification is carried out by dissolving the above synthetic resin in a suitable solvent such as dioxane, adding 0-naphthoquinonediazide sulfonic acid chloride, and adding dropwise an alkali such as alkali carbonate to the equivalence point while heating and stirring. You can get it.

In the esterified product, the overall ratio of 0-naphthoquinonediazide sulfonic acid chloride to the hydroxyl group of the phenol (reaction rate % 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 calculated by determining the content of sulfur atoms in the sulfonyl group by elemental analysis.

The amount of the resin obtained by condensing a substituted phenol represented by formula [VI] with an aldehyde and the 0-naphthoquinonediazide sulfonic acid ester compound of the resin in the photosensitive layer of the photosensitive lithographic printing plate of the present invention. is 0.05~15
The weight percent is preferably 1 to 10 weight percent, and the weight average molecular weight MW is preferably 5.0×102
~5.0x103, more preferably 7.0
The range is from ×102 to 3.0×103. Its number average molecular weight Mn is 3. It is preferably in the range of OX 102 to 2.5X 103, more preferably 4.0x102
It is in the range of ~2.0×103.

The above molecular weight is measured by GPC. Calculation of the number average molecular weight Mn and weight average molecular weight IMW is described in Morio Tsuge, Tatsuya Miyabayashi, and Masayuki Tanaka, "Journal of the Chemical Society of Japan," pages 800-805.
(1972), by leveling the peaks of the oligomer region (connecting the centers of the peaks and valleys of the peaks).

The photosensitive lithographic printing plate of the present invention may further contain a compound having at least one of the following structural units [C] and [0] in its molecular structure.

Structural unit [C] +0 mouth 20 eyes 20 teeth structural unit [D] H3 +Cro2CH-0 Rei (in the formula, n represents an integer from 2 to 5000) The structural unit [C] used in the present invention and The compound having at least one kind of [D] may be any compound as long as it has one or both of the above structural units [C] and [D], but in particular, compounds having n in the range of 2 to 5000 may be used. A compound in which n is an integer and a boiling point of 240°C or higher is preferable, a compound in which n is an integer in the range of 2 to 500 and a boiling point is 280°C or higher is more preferable, and the most preferable is a compound in which n is an integer in the range of 2 to 500 and a boiling point of 280°C or higher. It is a compound within the range of 3 to 100.

Examples of such compounds include: ・Polyethylene glycol (HO → CH2CH2O sweet H
)・Polyoxyethylene alkyl ether (RO(cH
t CHt O)n H)・Polyoxyethylene alkylphenyl ether・Polyoxyethylene polystyrylphenyl ether・Polyoxyethylene-polyoxybrobylene glycol (including block polymer and random polymer)・Polyoxyethylene-polyoxy Brobylene alkyl ether (the terminal forms an alkyl ether) (however,
(including random polymer) ・Ethylene oxide derivative of alkylphenol formalin condensate ・Polyoxyethylene alkylamine ・Polyoxyethylene polyhydric alcohol fatty acid partial ester〇HO (cHzCH-0)nH CH,0(cH,CH,0)nH ・Examples include polyoxyethylene fatty acid ester (eg, RCOO(cHiCH20)nH).

Specifically, the following are preferable, for example.

Namely, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene higher alcohol ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene tetraoleate Rensorbit, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, polyethylene glycol distearate, polyoxyethylene nonylphenyl ether formaldehyde condensate, oxyethylene oxybrobylene block copolymer, polyethylene glycol, tetra Ethylene glycol, etc.

Above lI43! The proportion of the compound having at least one of the units [C] and [D] in the photosensitive layer of the photosensitive lithographic printing plate is preferably 0.1 to 20% by weight, more preferably 0.62 to 10% by weight. .

Moreover, the above-mentioned compounds may be used alone or in combination of two or more types, as long as the content is within the above-mentioned range.

In addition to the above-mentioned materials, a sensitizer, a plasticizer, a surfactant, etc. can be added to the photosensitive planographic printing plate of the present invention, if necessary.

Furthermore, by dissolving each of these components in the following solvent and further applying and drying this on the surface of a suitable support,
A photosensitive layer can be provided to form a photosensitive lithographic printing plate.

Solvents that can be used to dissolve each component of the photosensitive composition forming the photosensitive lithographic printing plate of the present invention include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate;
Examples include dimethylformamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, methyl ethyl ketone, and the like. These solvents can be used alone or in combination of two or more.

The coating method used when coating the above-mentioned photosensitive composition on the surface of the support includes conventionally known methods such as spin coating,
Wire bar coating, dip coating, air knife coating,
Roll coating, blade coating, curtain coating, etc. are possible. At this time, the coating amount varies depending on the application, but is preferably 0.5 to 5 OU/f in terms of solid content.

In the photosensitive lithographic printing plate of the present invention, the support on which the photosensitive layer is provided includes metal plates such as aluminum, zinc, steel, and copper;
Also, metal plates plated or vapor-deposited with chromium, zinc, copper, nickel, aluminum, iron, etc., paper, plastic films and glass plates, paper coated with resin, paper covered with metal foil such as aluminum, hydrophilized Examples include treated plastic films. Among these, aluminum plates are preferred. As the support for the photosensitive lithographic printing plate of the present invention, it is more preferable to use an aluminum plate that has been 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 a method using 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 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 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 anodized skin II formed is 1 to 50I1g/
df is appropriate, preferably 10 to 40!1 Mdf. The amount of anodized film can be determined, for example, by immersing an aluminum plate in a phosphoric acid chromic acid solution (85% phosphoric acid solution: 35 mN, prepared by dissolving chromium oxide (■> = 20a in IIl water) to dissolve the oxide film. However, it can be determined by measuring the weight change before and after dissolving the film on the plate.

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 using an aqueous solution of a water-soluble polymer compound or a metal salt such as fluorinated zirconate.

The photosensitive lithographic printing plate of the present invention can be developed by a conventional method. For example, ultra-high pressure mercury lamps, metal halide lamps, xenon lamps,
It is exposed to light using a light source such as a tungsten lamp, and then developed with various alkaline developers. As a result, only the unexposed portion remains on the surface of the support, forming a positive-positive relief image.

Examples of the alkaline developer include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate,
Examples include aqueous solutions of alkali metal salts such as sodium metasilicate, potassium metasilicate, sodium diphosphate, and sodium triphosphate. The concentration of alkali metal salt is 0.
1 to 10% by weight is preferred. Furthermore, an anionic surfactant, an amphoteric surfactant, and an organic solvent such as alcohol can be added to the developer as required.

[Example] (Preparation of aluminum plate) An aluminum plate with a thickness of 0.24 mm (Material 1050, refining port 16) was heated in a 5% by weight sodium hydroxide aqueous solution.
After degreasing for 1 minute at 0°C, the temperature: 25°C, current density +60A/
d, = Processing time: Electrolytic etching was performed under the conditions of 30 seconds. Next, after desmutting in a 5% by weight aqueous sodium hydroxide solution at 60°C for 10 seconds,
0wt%rli! Anodization treatment was performed in a tM solution at a temperature of 20° C., a current density of 3 A/df, and a treatment time of 1 minute.

Furthermore, hydrothermal puncture treatment was performed with hot water at 30°C for 20 seconds,
An aluminum plate as a support for lithographic printing plate material was produced.

A photosensitive composition coating solution having the following composition was applied to the aluminum plate prepared as described above using a spin coater and dried at 90° C. for 4 minutes to obtain a positive photosensitive lithographic printing plate sample No. 011.

(Photosensitive composition coating liquid composition> Novolac resin A Book 2 7.5CI
・Ester compound of the present invention N0.1 *1 1.7
g.Halogen free radical generating compound A *3 0.1
P. Victoria Pure Blue - 80 days o, o
sg (manufactured by Hodogaya Kagaku ■) - 100 g of methyl cellosolve In addition, in the above photosensitive composition coating solution composition, the ester compound of the present invention and its amount, the novolac resin, and the halogen free radical generating compound, as shown in Table 1, were added, respectively. Photosensitive lithographic printing plate samples Nos. 12 to 5 were obtained by changing the method.

A step tablet for sensitivity measurement (Eastman
A 2 KW metal halide lamp (Iwasaki Electric company idle fin 200
0) as a light source under conditions of 8.0 mW/Ct'. Next, this sample was developed for 20 seconds at 27°C with a developer (I! semi-developer) prepared by diluting 5DR-1 (manufactured by Konica ■) with water to 6@, and the non-image area was completely removed. A lithographic printing plate was obtained. The gradation was evaluated from the difference in the number of clear and solid steps after development. Furthermore, the reproducibility of the 2% halftone dots of the film with a density of 2.0 (blackened area) was visually evaluated.

Furthermore, in order to examine over-developability, the exposed sample was incubated at 27°C using a standard developer in which 5DR1 was diluted 6 times.
The film was developed for 40 seconds, and over-developability was determined based on the increase in the number of solid steps compared to standard development. The smaller the increase in the number of solid steps, the better the over-development performance.

*1; O-quinonediazide compound ester compound (esterification rate 80%) ester compound (esterification rate 100%) ester compound (esterification rate 100%) ester compound qkJ (esterification rate 100%) Book 2: Novolac resin Novolac resin A Copolycondensation resin of phenol, m-cresol, p-cresol, and formaldehyde (molar ratio of phenol, m-cresol, and p-cresol each is 2.0: 4.8: 3.2. MW
=7.500. Mw /Mn -5,8)・Novolac resin B Copolycondensation resin of wound-cresol, p-cresol, and formaldehyde (mole ratio of m-cresol and p-cresol is 6.0
: 4.0. My −5,500, Mw /Mn
-5,0) Ning 3; Halogen Ti leaving group forming compound [Effects of the invention] As explained in detail above, the present invention has excellent reproducibility of halftone dots during printing, especially reproducibility of small dots, and It is possible to provide a photosensitive lithographic printing plate which has wide development tolerance in both developability and over-developability and has excellent exposure visible image properties.

Claims (1)

[Claims] On the support, at least (a) 2,3,4,3',4'
, 1,2-naphthoquinonediazide-4-sulfonic acid ester compound and/or 1,2-naphthoquinonediazide-5-sulfonic acid ester compound of 5'-hexahydroxybenzophenone, (b) alkali-soluble novolak resin, (c ) A photosensitive composition comprising a compound that generates halogen free radicals upon irradiation with actinic radiation, and (d) a color change agent that changes its color tone by interacting with the decomposition product of (c). A photosensitive lithographic printing plate having layers.