JPH0635179A - Positive photosensitive composition for printing plate - Google Patents

Abstract

PURPOSE:To obtain a positive photosensitive compsn. for a printing plate capable of enhancing sensitivity without exerting an unfavorable influence on other important characteristics such as development latitude by incorporating a specified additive. CONSTITUTION:This positive photosensitive compsn. for a printing plate contains a compd. represented by the formula besides an o-quinone-diazido compd. or a diazonium salt. In the formula, each of R1-R5 is H, hydroxyl, halogen, alkyl, alkoxy or alkenyl and at least one of R1-R5 is hydroxyl.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive-working photosensitive composition for a lithographic printing plate and a lithographic printing plate, which is suitable for production of proof printing for multicolor printing, and particularly contains an o-quinonediazide compound or a diazonium salt. The present invention relates to a positive-type photosensitive composition in which a specific compound is added to the photosensitive printing plate composition to increase the sensitivity. More specifically, it relates to a positive-working photosensitive composition for a printing plate, which can enhance the sensitivity without affecting development acceptability.

[0002]

2. Description of the Related Art Conventionally, in the use of lithographic printing plates, various proposals have been made as a photosensitive composition that is solubilized by actinic rays, that is, has a positive action. For example, an o-quinonediazide compound is contained on an aluminum substrate. It is known that a photosensitive composition or a photosensitive composition containing a diazonium salt is provided. The o-quinonediazide compound is the most studied positive type photosensitive compound, and is known to be decomposed by irradiation with actinic rays to generate a 5-membered carboxylic acid, which is soluble in an alkaline aqueous solution. . Examples of such o-quinonediazide compounds include, for example, U.S. Pat. Nos. 2,766,118 and 2,767,092.
, No. 2,772,972, No. 2,859,112, No. 2,907,
No. 665, No. 3,046,110, No. 3,046,111, No. 3,
No. 046,115, No. 3,046,118, No. 3,046,119, No. 3,046,120, No. 3,046,121, No. 3,046,122
No. 3,046,123, No. 3,061,430, No. 3,102,
No. 809, No. 3,106,465, No. 3,635,709, No. 3,
It is described in numerous publications, including the specification No. 647,443. By using these compounds, good positive image quality can be formed, but on the other hand, the photochemical sensitization of the o-quinonediazide compound is difficult, and the quantum yield does not essentially exceed 1. None of them showed sufficient sensitivity. Heretofore, various proposals have been made for a method of increasing the positive type photosensitivity of the o-quinonediazide system, but no satisfactory method has been obtained. For example o
When the amount of the quinonediazide compound is reduced, the sensitivity is apparently increased, but the development tolerance at the time of development (the time width allowed for obtaining the optimum development result) is narrowed accordingly, which is not practical.

A system in which an o-quinonediazide compound is combined with a binder resin having a high solubility in an alkaline aqueous solution gives the same result as described above. Further, some techniques for increasing sensitivity by adding a non-photosensitive compound (sensitizer) to a photosensitive composition containing an o-quinonediazide compound have been proposed. It does not exist and has various drawbacks at present. For example, as described in U.S. Pat.No. 3,661,582,
Certain heterocyclic compounds, such as 2-azacyclonanone-
Although the sensitivity can be improved by adding 2-one, indole, quinazoline and tetrazole, in this case as well, as in the case described above, the development tolerance was extremely narrow. Further, Japanese Patent Publication No. 46-42449 discloses that
Various additives for increasing the photosensitivity such as triphenylmethane dye, benzaldehyde-m-tolylhydrazine, halogenated hydrocarbons and azo dyes are described, but these compounds have a remarkable sensitizing effect. Does not have.

For the same purpose, JP-A-50-36203 discloses a sulfimide of o-benzoic acid, hydantoin and its derivative, and thiohydantoin and its derivative.
No. 52-80022 proposes an acid anhydride additive.
However, in these cases as well, there was a drawback that the developing tolerance at the time of development was narrowed when the addition amount was such that the increase in sensitivity was recognized. Further, JP-A-55-73045 proposes the addition of a condensation product of hydroxybenzophenone and formaldehyde for the purpose of increasing the sensitivity, but a considerable amount of addition is required for a clear increase in sensitivity. However, the reduction in development acceptability and chemical resistance was unavoidable. Further, JP-A-57-118237 and JP-A-57-1182
No. 38 describes several kinds of compounds for the purpose of increasing the sensitivity, but it has a drawback in development acceptability. On the other hand, as a positive type composition containing a diazonium salt, for example, U.S. Pat. Nos. 3,219,447, 3,211,553 and JP-B-39-
Examples thereof include those described in JP-A No. 7663 and JP-A No. 52-2519, but they cannot be put to practical use because they have low sensitivity and lack stability in image formation. US Pat. No. 3,661,58 for the purpose of increasing the sensitivity of these photosensitive compositions.
Attempts were made to add the compounds described in JP-A No. 2 and JP-A No. 52-80022, but as with the o-quinonediazide positive-working photoreceptor, it was not possible to achieve both high sensitivity and development acceptability. .

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to include specific additives to improve sensitivity without adversely affecting other important properties such as development acceptability. It is to provide a positive photosensitive composition for a plate.

[0006]

Means for Solving the Problems The present invention has the above object by incorporating a compound represented by the following general formula (I) into a positive photosensitive composition for a printing plate containing an o-quinonediazide compound or a diazonium salt. Has been achieved.

[0007]

[Chemical 2]

Here, R _{1 to} R ₅ represent a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group or an alkenyl group, and may be the same or different. However, at least one of R _{1 to} R ₅ is a hydroxyl group. The positive photosensitive composition for a printing plate of the present invention will be described in detail below. The positive photosensitive composition for a printing plate of the present invention comprises a support and a positive photosensitive composition containing an o-quinonediazide compound or a diazonium salt provided on the support, and an undercoat layer between them if necessary. In which a matte layer is provided on the photosensitive composition layer.

The support used in the present invention is a dimensionally stable plate-like material, for example, paper, paper laminated with plastic (eg polyethylene, polypropylene, polystyrene, etc.), metal plate ( For example, aluminum, zinc, copper, etc., plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate,
Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper laminated with the above metal, or vapor-deposited, or a plastic film is included. Among them, an aluminum plate, which has good dimensional stability and is relatively inexpensive, is particularly preferable.
Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and containing a slight amount of a foreign element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of foreign elements in the alloy is at most 10% by weight. Particularly suitable aluminum in the present invention is
Although it is pure aluminum, completely pure aluminum is difficult to produce due to refining technology, and thus may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and conventionally known and publicly known aluminum plates can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm. Prior to roughening the aluminum plate, if desired, a degreasing treatment for removing rolling oil on the surface is performed, for example, with a surfactant, an organic solvent, or an alkaline aqueous solution.

The surface roughening treatment of the surface of the aluminum plate is carried out by various methods, for example, a method of mechanically roughening the surface, a method of electrochemically melting and roughening the surface and a chemical surface. Is selectively dissolved. As the mechanical method, known methods such as a ball polishing method, a brush polishing method, a blast polishing method and a buff polishing method can be used. As an electrochemical graining method, there is a method of performing alternating current or direct current in a hydrochloric acid or nitric acid electrolytic solution. Further, as disclosed in JP-A-54-63902, a method of combining the two can be used. The thus roughened aluminum plate is subjected to alkali etching treatment and neutralization treatment, if necessary, and then, if desired, subjected to anodization treatment in order to enhance water retention and abrasion resistance of the surface. As the electrolyte used for the anodizing treatment of the aluminum plate, it is possible to use various electrolytes which form a porous oxide film, generally, sulfuric acid, phosphoric acid, oxalic acid,
Chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The treatment conditions for anodic oxidation vary depending on the electrolyte used and cannot be specified unconditionally, but generally the concentration of the electrolyte is from 1 to
80% by weight solution, liquid temperature 5-70 ° C, current density 5-60
A / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are suitable. The amount of anodized film is 1.0 g /
When it is less than m ² , printing durability is insufficient, or the non-image area of the lithographic printing plate is easily scratched, and so-called “scratch stain” in which ink adheres to the scratched portion during printing is likely to occur.
After being subjected to anodizing treatment, the aluminum surface is optionally subjected to hydrophilic treatment. Examples of the hydrophilic treatment used in the present invention include U.S. Patents 2,714,066 and 3,181,46.
There are alkali metal silicate (eg aqueous sodium silicate) processes such as those disclosed in Nos. 1, 3,280,734 and 3,902,734. In this method, the support is dipped or electrolyzed in an aqueous sodium silicate solution. Besides, potassium fluorozirconate disclosed in JP-B-36-22063 and US Pat.
Methods such as treatment with polyvinylphosphonic acid as disclosed in Nos. 276,868, 4,153,461 and 4,689,272 are used.

Next, the positive photosensitive composition to which the compound represented by the general formula (I) is added will be described. As the positive photosensitive composition, a conventionally known photosensitive composition containing an o-quinonediazide compound or a diazonium salt can be used. These photosensitive compositions are mainly composed of an o-quinonediazide compound or diazonium salt and an alkali-soluble binder, and it is particularly preferable that the alkali-soluble binder is a phenolic resin.
The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group,
It increases alkali solubility by irradiation with actinic rays,
Compounds of various structures can be used. For example,
J. Wright-Sensitive Systems by Coser
(John Wiley & Sons. Inc.) The compounds described on pages 339 to 352 can be used, but in particular, they have been reacted with various aromatic polyhydroxy compounds or aromatic amino compounds.
-Sulfonic acid esters or sulfonic acid amides of quinonediazide are preferred. Further, benzoquinone (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,3) as described in JP-B-43-28403.
2) -diazide sulfonic acid chloride and pyrogallol-
Esters with acetone resins, the benzoquinones described in U.S. Pat.Nos. 3,046,120 and 3,188,210.
An ester of (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazido sulfonic acid chloride and a phenol-formaldehyde resin is also preferably used. Other useful o-quinonediazide compounds are reported and known in numerous patents.
For example, JP-A 47-5303, JP-A 48-63802, and JP-A
48-63803, JP-A-48-96575, JP-A-49-38701
No. 4, JP-A-48-13354, JP-B-41-11222, JP-B-SHO
45-9610, Japanese Patent Publication No. 49-17481, U.S. Pat.No. 2,797,21
No. 3, No. 3,454,400, No. 3,544,323, No. 3,57
No. 3,917, No. 3,674,495, No. 3,785,825, British Patent No. 1,227,602, No. 1,251,345, No. 1,267,00
Examples include those described in each specification such as No. 5, No. 1,329,888, No. 1,330,932, and German Patent No. 854,890.

The diazonium salt used in the present invention includes US Pat. Nos. 3,219,447 and 3,211,553,
Japanese Patent Publication No. 39-7663, Japanese Patent Publication No. 52-2519, and Japanese Patent Application No. 3-3258.
Known diazonium salts described in No. 59 and the like can be mentioned. Examples of particularly effective diazonium salts include, but are not limited to, compounds represented by the following general formulas (II), (III), (IV) and (V).

[0013]

[Chemical 3]

In the formula, R ¹ represents an alkyl group having 3 to 18 carbon atoms or a substituted alkyl group, R ² represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkoxy group, a substituted alkoxy group, A phenoxy group, a substituted phenoxy group or a halogen atom is shown. X ⁻ represents a counter anion. n is an integer of 1 to 4, m is an integer of 1 to 3,
n + m = 4. R ³ and R ⁴ each independently represent an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group. R ³ and R ⁴ are bonded to each other to form a morpholino group,
A heterocyclic group such as a piperidino group, a piperazinyl group and a pyrrolidinyl group may be formed. Y is an oxygen atom, a sulfur atom,
-NH -, - CH ₂ -, or -C (CH _{3) 2} - shows a. Z is a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkoxy group, a substituted alkoxy group, an alkylcarbonyl group, a substituted alkylcarbonyl group, an arylcarbonyl group, a substituted arylcarbonyl group, a cyano group,
Indicates a nitro group or a halogen atom. k represents an integer of 1 to 5. Q represents a divalent linking group.

The amount of the o-quinonediazide compound or diazonium salt used in the present invention is preferably 1 to 50% by weight, more preferably 5 to 30% by weight, based on the total solid content of the photosensitive composition. is there. These compounds can be used alone, but may be used as a mixture of several kinds. The alkali-soluble binder used in the present invention is preferably a phenolic hydroxy group, a carboxylic acid group, a sulfonic acid group, an imide group, a sulfonamide group, N
It is a polymer having an acidic group of pKall or less such as -sulfonylamide group, N-sulfonylurethane group and active methylene group. Suitable alkali-soluble polymers include novolac type phenol resins, specifically, phenol-formaldehyde resin, o-cresol-formaldehyde resin, m-cresol-formaldehyde resin, p-cresol-formaldehyde resin, xylenol-formaldehyde resin, or these. There are co-condensates. Further, as described in JP-A-50-125806, t-butylphenol-
A condensate of formaldehyde and phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms and formaldehyde may be used in combination. Further, homopolymers or copolymers of N-hydroxystyrene, m-isopropenylphenol, p-isopropenylphenol and the like, and polymers obtained by partially etherifying or partially esterifying these polymers can also be used. Furthermore, acrylic acid, a polymer having a carboxy group-containing monomer such as methacrylic acid as a copolymerization component, a carboxy group-containing polyvinyl acetal resin described in JP-A-61-267042, a carboxyl group described in JP-A-63-124047. A containing polyurethane resin is also preferably used. Furthermore, N- (4-sulfamoylphenyl) methacrylamide, N-phenylsulfonylmethacrylamide, a polymer containing maleimide as a copolymerization component, and an active methylene group-containing polymer described in JP-A-63-127239 can also be used. . These alkali-soluble polymers can be used alone, but may be used as a mixture of several kinds. The amount of the alkali-soluble polymer added to the photosensitive composition is preferably 5 to 99% by weight, more preferably 10 to 90% by weight, based on the total solid content of the photosensitive composition.

Next, the compound represented by formula (I) will be described. By adding the compound represented by formula (I) to a positive photosensitive composition, the sensitivity can be improved without adversely affecting other important characteristics such as development acceptability. In R _{1 to} R ₅ of the general formula (I), the halogen atom is a chlorine atom, a bromine atom or an iodine atom, and the alkyl group is a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, s
carbon number 1 to 1 such as ec-butyl group or t-butyl group
The alkyl group of 4 is a methoxy group as an alkoxy group,
Ethoxy group, hydroxyethoxy group, propoxy group, hydroxypropoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group or t-
An alkoxy group having 1 to 4 carbon atoms such as a butoxy group is preferable. The alkenyl group is preferably a C2-C4 alkenyl group such as a vinyl group, a propenyl group, an allyl group or a butenyl group. The compound represented by the general formula (I) can be obtained, for example, by the method described in European Patent 208376, that is, by reacting cyanuric chloride with an aminophenol derivative. Specific examples of the compound represented by the general formula (I) thus obtained include 2,4,6-tris (3′-hydroxyphenyl) -amino-s-triazine and 2,4,6.
-Tris (4'-hydroxyphenyl) -amino-s-triazine, 2,4,6-tris (3'-methyl-4'-hydroxyphenyl) -amino-s-triazine, 2,4,6-tris ( 3 ', 5'-dimethyl-4'-hydroxyphenyl) -amino-s-triazine, 2,4,6-tris (3'-chloro-
4'-hydroxyphenyl) -amino-s-triazine, 2,4,6-tris (3 ', 5'-dichloro-4'-hydroxyphenyl) -amino-s-triazine, 2,4,6-tris ( 3 ', 5'-dibromo-4'-hydroxyphenyl) -amino-s-triazine, 2,4,6-tris (3'-chloro-4'
-Methylphenylphenyl) -amino-s-triazine, 2,4,6-tris (3'-bromo-4'-hydroxy-5 '
-Methylphenyl) -amino-s-triazine and the like can be mentioned, but the invention is not limited thereto. These compounds may be used alone or in combination of two or more. The compounding amount of the compound represented by the general formula (I) is
Usually 150 per 100 parts by weight of quinonediazide compound
It is not more than 5 parts by weight, preferably 5 to 100 parts by weight. If the use ratio is less than 5 parts by weight, the effect of increasing the sensitivity is not substantially obtained, and if it exceeds 150 parts by weight, the residual film rate is significantly reduced. If desired, various additives may be added to the positive photosensitive composition of the present invention. For example, carbon number 3 such as octylphenol formaldehyde resin
It is preferable to use a condensate of phenol and formaldehyde having an alkyl group of 8 to 8 as a substituent in order to improve the oil sensitivity of the image.

Further, cyclic acid anhydrides, phenols and organic acids may be used in combination for the purpose of further improving the sensitivity. Examples of cyclic acid anhydrides are phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-entoxy-Δ ⁴ -tetrahydrophthalic anhydride and tetrachlorophthalic anhydride described in U.S. Pat. No. 4,115,128. , Maleic anhydride, chloromaleic anhydride, α-phenyl maleic anhydride, succinic anhydride, pyromellitic dianhydride, etc. can be used. Examples of phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ', 4. "-
Trihydroxytriphenylmethane, 4,4 ', 3 ",
4 ″ -tetrahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane and the like. Further, as organic acids, JP-A-60-88942 and JP-A-2-9675 are available.
There are sulfonic acids, sulfinic acids, alkylsulfates, phosphonic acids, phosphoric acid esters, carboxylic acids, etc. described in Japanese Patent No. 5 and the like.
-Toluenesulfonic acid, dodecylbenzenesulfonic acid,
p-toluenesulfinic acid, ethylsulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid,
p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 1,4-cyclohexene-2,2-
Examples thereof include dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, and ascorbic acid. The proportion of the above cyclic acid anhydride, phenols and organic acids in the photosensitive composition is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

Further, the photosensitive composition of the present invention is described in JP-A-62-251740 and Japanese Patent Application No. 2-188 in order to broaden the stability of processing under developing conditions. Nonionic surfactants such as those described in JP-A-59-121044
Amphoteric surfactants such as those described in JP-A No. 2-115992 and Japanese Patent Application No. 2-115992 can be added. Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, and polyoxyethylene nonylphenyl ether. Specific examples of the amphoteric surfactant include alkyldi (aminoethyl)
Glycine, alkylpolyaminoethylglycine hydrochloride,
2-alkyl-N-carboxyethyl-N-hydroxyethyl imidazolinium betaine and N-tetradecyl-
Examples include N, N-betaine type surfactants (for example, trade name Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.) and the like. The proportion of the nonionic surfactant and the amphoteric surfactant in the photosensitive composition is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

In the photosensitive composition of the present invention, a printout agent for obtaining a visible image immediately after exposure and a dye or pigment as an image colorant can be added. Typical examples of the printout agent include a combination of a compound that releases an acid upon exposure (photoacid releasing agent) and an organic dye capable of forming a salt. Specifically, JP-A-50-36209,
Combinations of o-naphthoquinonediazide-4-sulfonic acid halogenide and salt-forming organic dyes described in JP-A-53-8128 and JP-A-53-36223 and JP-A-54-74728.
No. 60-3626, No. 61-143748, No. 61-151644 and No. 63-58440, combinations of trihalomethyl compounds and salt-forming organic dyes can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent stability over time and give a clear printout image.
As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dye. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101,
Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue #
603, oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (C
I42535), ethyl violet, rhodamine B
(CI145170B), Malachite Green (CI4
2000), methylene blue (CI52015) and the like. The dyes described in JP-A-62-293247 are particularly preferable. These dyes
It can be added to the photosensitive composition in a proportion of 0.01 to 10% by weight, preferably 0.1 to 3% by weight, based on the total solid content of the photosensitive composition. If necessary, a plasticizer is added to the photosensitive composition of the present invention in order to impart flexibility to the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid. Acid oligomers and polymers are used.

The positive photosensitive composition of the present invention is usually prepared by dissolving each of the above components in a solvent and coating the solution on a support. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethoxyacetamide,
N, N-dimethylformamide, tetramethylurea,
Examples thereof include N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyl lactone and toluene, but are not limited thereto. These solvents may be used alone or as a mixture. The concentration of the above components (total solids including additives) in the solvent is preferably 1-5.
It is 0% by weight. The coating amount (solid content) on the support obtained after coating and drying varies depending on the use, but is generally preferably 0.5 to 5.0 g / m ² for the photosensitive printing plate. Various methods can be used for coating, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the photosensitive film deteriorate. A printing plate using the positive-type photosensitive composition for a printing plate of the present invention is one in which a positive-type photosensitive composition containing an o-quinonediazide compound or a diazonium salt is provided on a support, but if necessary. An undercoat layer may be provided therebetween, and a matte layer may be provided on the photosensitive composition layer. Various organic compounds are used as the undercoat layer component, and examples thereof include phosphonic acids having an amino group such as carboxymethyl cellulose, dextrin, gum arabic, and 2-aminoethylphosphonic acid, and phenylphosphonic acid which may have a substituent. , Naphthylphosphonic acid, alkylphosphonic acid glycerophosphonic acid, organic phosphonic acid such as methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphoric acid, phenylphosphinic acid which may have a substituent, naphthylphosphinic acid, organic phosphinic acid such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and triethanolamine hydrochloride. Such as hydroxy -Alanine, and hydrochlorides of amines having a, may be used by mixing two or more.

This organic undercoat layer can be provided by the following method. That is, water or a solvent in which the above organic compound is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof is applied on an aluminum plate and dried to provide a method, and water or methanol, ethanol, methyl ethyl ketone, etc. Is a method in which an aluminum plate is immersed in a solution prepared by dissolving the above organic compound in an organic solvent or a mixed solvent thereof to adsorb the above compound, followed by washing with water or the like and drying to form an organic undercoat layer. . In the former method, a solution having a concentration of 0.005 to 10% by weight of the above organic compound can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, and the immersion temperature is 20 to 90 ° C, preferably 25 to 50%.
℃, the immersion time is 0.1 to 20 minutes, preferably 2 seconds to
1 minute. The solution used for this can be used in a pH range of 1 to 12 depending on the basic substance such as ammonia, triethylamine, potassium hydroxide or the like, or the acidic substance such as hydrochloric acid or phosphoric acid. Further, a yellow dye may be added to improve the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the organic undercoat layer is appropriately ² to 200 mg / m ² , and preferably 5 to 100 mg / m ² . The above coating amount is 2 mg
If it is less than / m ² , sufficient printing durability cannot be obtained. The same applies when the amount is larger than 200 mg / m ² . In addition, a matte layer is provided on the surface of the positive photosensitive composition layer of the present invention in order to shorten the vacuuming time during contact exposure using a vacuum baking frame and to prevent baking blur. Specifically, JP-A-50-125805, JP-B-57-6582, and JP-A-61-28986
Examples of the method include a method of providing a mat layer as described in JP-A No. 62-62337 and a method of heat-bonding a solid powder as described in JP-B-62-62337. The average diameter of the mat layer used in the present invention is preferably 100 μm or less, and more preferably 2 to 8 μm. When the average diameter is large, it is difficult to attach fine lines and the number of highlight dots is reduced, which is not preferable for tone reproduction. Average diameter is 2 μm
In the following, vacuum adhesion is insufficient and baking blur occurs. The coating amount of the mat layer is preferably from 5 to 200 mg / m ^2, more preferably from 20~150mg / m ^2. If the coating amount is larger than this range, it may cause scratches, and if it is smaller than this range, the vacuum adhesion becomes insufficient.

The positive type photosensitive printing plate prepared as described above is usually subjected to an image exposure and development process. Examples of the light source of actinic rays used for image exposure include a mercury lamp,
There are metal halides, xenon lamps, chemical lamps, carbon arcs, etc. Radiation is electron beam, X
Rays, ion beams, far infrared rays, etc. Also g line, i
Lines, Deep-UV light, high-density energy beams (laser beams) are also used. Examples of the laser beam include helium / neon laser, argon laser, krypton laser, helium / cadmium laser, and KrF excimer laser. As a developer and a replenisher for a printing plate using the positive photosensitive composition for a printing plate of the present invention, a conventionally known alkaline aqueous solution can be used.
For example, sodium silicate, potassium, sodium triphosphate, potassium, ammonium, dibasic sodium, potassium, ammonium, sodium bicarbonate, potassium bicarbonate, ammonium, sodium carbonate,
Examples thereof include inorganic alkali salts such as potassium, ammonium, sodium hydrogen carbonate, potassium carbonate, ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium. Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine,
Diisopropylamine, triisopropylamine, n-
Organic alkali agents such as butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine and pyridine are also used. These alkaline agents may be used alone or in combination of two or more. Among these alkaline agents, a particularly preferable developing solution is an aqueous silicate solution such as sodium silicate or potassium silicate. The reason is that silicon oxide SiO ₂ which is a component of silicate and alkali metal oxide M
_This is because the developing property can be controlled by the ratio and concentration of ₂ O, and for example, JP-A-54-62004 and JP-B-57-
Alkali metal silicates such as those described in 7427 are effectively used. Further, when developing using an automatic developing machine, by adding an aqueous solution (replenisher) having a higher alkaline strength than the developing solution to the developing solution, a large amount of the developing solution in the developing tank can be replaced without changing the developing solution. It is known that PS plates can be processed. Also in the present invention, this replenishment system is preferably applied.

The developer and replenisher used in the present invention may contain various kinds of surfactants as necessary for the purpose of promoting or suppressing the developability, dispersing the development residue and enhancing the ink affinity of the image portion of the printing plate. Organic solvents can be added. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Further, in the developing solution and the replenishing solution used in the present invention, if necessary, a reducing agent such as sodium salt and potassium salt of inorganic acids such as hydroquinone, resorcin, sulfurous acid, and bisulfite, further organic carboxylic acid, and defoaming agent. Agents and water softeners can also be added. The printing plate developed using the above-mentioned developing solution and replenishing solution is post-treated with washing water, a rinse solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. Various combinations of these treatments can be used for the post-treatment of the printing plate of the present invention. In recent years, in the plate making / printing industry, automatic developing machines for printing plates have been widely used in order to rationalize and standardize the plate making work. This automatic developing machine is generally composed of a developing section and a post-processing section, and is composed of a device for conveying a printing plate, each processing liquid tank and a spraying device, which conveys an exposed printing plate horizontally while pumping it up with each pump. The processing liquid is sprayed from a spray nozzle for development processing. Also,
Recently, a method has also been known in which a printing plate is dipped and conveyed by a submerged guide roll or the like in a treatment liquid tank filled with the treatment liquid for treatment. In such automatic processing, it is possible to perform processing while supplementing each processing solution with a replenishing solution according to the processing amount, operating time, and the like. Further, a so-called disposable processing method of processing with a substantially unused processing liquid can be applied. The planographic printing plate obtained by such treatment is applied to an offset printing machine or the like and used for printing a large number of sheets.

[0024]

The present invention will be described in detail below with reference to examples, but the invention is not limited thereto. Examples 1 to 3 and Comparative Examples a to e An aluminum plate (material: 1050) having a thickness of 0.3 mm was washed with trichlene and degreased, and then the surface was grained using a nylon brush and a 400-mesh Pasmy water suspension. Soaked and washed well with water. This plate was immersed in a 25% sodium hydroxide aqueous solution at 45 ° C. for 9 seconds for etching, washed with water, and further immersed in 20% nitric acid for 20 seconds and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was made to have a current density of 15% using 7% sulfuric acid as an electrolytic solution.
After a direct current anodized film of 3 g / m ² in A / dm ^2, washed with water and dried. Next, the following photosensitive liquids (see Table 1) Examples 1 to 3 and Comparative Examples a to e were applied to the aluminum plate, and dried at 100 ° C. for 2 minutes to prepare positive photosensitive printing plates 1 to 3.
3 and a to e were obtained. The applied amount after drying is 2.4
Was about 2.5 g / m ² . After exposing these positive type photosensitive printing plates from a distance of 70 cm with a 30 amp carbon arc lamp, they were automatically diluted with an 8 times dilution solution of DP-4 (trade name: Fuji Photo Film Co., Ltd.) at 25 ° C. for 40 seconds. Development (800 U: by Fuji Photo Film Co., Ltd. automatic developing machine) was performed. The appropriate exposure time at this time is 0.15 for density difference.
5 in gray scale (manufactured by Fuji Photo Film Co., Ltd.)
The point at which the step became completely clear was defined as the sensitivity of the photosensitive printing plate. In addition, it is 25 ° C with an 8 times dilution of DP-4.
In the bat development of 40 seconds, the time during which the number of solid steps of the gray scale at the time of 40 seconds development changes by two steps (hereinafter referred to as development tolerance) was determined. Table 2 shows the results of the sensitivity (exposure time) and development acceptability of these positive photosensitive printing plates.

[0025]

[Table 1] Table 1 Photosensitive solution ─────────────────────────────────── Example 1 Example 2 Implementation Example 3 ─────────────────────────────────── Naphthoquinone-1,2-diazide-5-su 0.90 0.90 0.90 Rufonic acid chloride and ester compound of pyrogallol-ace (g) ton resin Cresol-formaldehyde resin 1.70 1.70 1.70 t-Butylphenol-formaldehyde 0.05 0.05 0.05 Resin naphthoquinone-1,2-diazido-4-su 0.03 0.03 0.03 Rufonic acid chloride Oil Blue # 603 0.02 0.02 0.02 2,4,6-Tris (3'-hydroxyphenyl) 0.30 --- Amino-s-triazine 2,4,6-Tris (3'-methyl-4'-hydro-0.30- Xyphenyl) -amino-s-triazine 2,4,6-tris (3'- Lolo-4'-hydro--0.30 xyphenyl) -amino-s-triazine tetrahydrophthalic anhydride --- 2,3,4-trihydroxybenzopheno --- condensation product of formaldehyde with gallic acid --- methyl ethyl ketone 8 8 8 2-Methoxyethyl acetate 15 15 15 ─────────────────────────────────── Table 1 (continued ) Photosensitive liquid ─────────────────────────────────── Comparative example a Comparative example b Comparative example c Comparative example d Comparative Example e ─────────────────────────────────── Naphthoquinone-1,2-di 0.90 0.70 0.90 0.90 0.90 Ester compound of azido-5-sulfonic acid chloride and pyrogallol-acetone resin Cresol-forma 2.00 2.20 1.85 1. 70 1.90 Ludehydride resin t-Butylphenol-0.05 0.05 0.05 0.05 0.05 Formaldehyde resin Naphthoquinone-1,2-di 0.03 0.03 0.03 0.03 0.03 Azido-4-sulfonic acid chloride Oil blue # 603 0.02 0.02 0.02 0.02 0.02 2,4,6-Tris (3 '------ Hydroxyphenyl) -amino-s-triazine 2,4,6-tris (3' ------ methyl-4'-hydroxyphenyl) -amino-s-triazine 2 , 4,6-Tris (3 ′ − − − − − − Chloro-4′-hydroxyphenyl) -amino-s-triazine tetrahydroanhydride phthal − −0.15 − − acid 2,3,4-trihydroxy − − − 0.30 − Condensate of benzophenone and formaldehyde Gallic acid − − − − 0.10 Methyl ethyl ketone 8 8 8 8 8 2-Methoxyethyl 15 15 15 15 15 Acetate ───────────────── ── ───────────────

[Table 2] Table 2 Performance evaluation table ───────────────────────── Sensitivity (exposure time) Development tolerance ───────── ───────────────── Example 1 55 (seconds) 7 minutes Example 2 50 7 minutes Example 3 55 7 minutes Comparative Example a 120 8 minutes Comparative Example b 90 3 minutes Comparative Example c 80 4 minutes Comparative Example d 85 5 minutes Comparative Example e 75 4 minutes ──────────────────────────

As can be seen from Table 2, in Examples 1 to 3 to which the compound of the general formula (I) of the present invention is added, the sensitivity is obviously increased (appropriate exposure time is short) as compared with Comparative Example a, and The development acceptability is slightly inferior to that of Comparative Example a, but is not a problem in practical use. On the other hand, in Comparative Example b in which the amount of the o-quinonediazide compound was decreased, the sensitivity was increased, but the development acceptability was greatly decreased. In addition, the sensitivity of any of the conventionally known additives increases, but the development acceptability also narrows. When printing tests were performed on Examples 1 to 3 and Comparative Example a containing no additive, other performances were satisfactory and good results were obtained.

Example 4 Ester compound of 0.85 g of naphthoquinone-1,2-diazide-5-sulfonic acid chloride and m-cresol-formaldehyde resin 1.85 g of cresol-formaldehyde resin 2,4,6-tris (4 ') -Hydroxyphenyl) -amino-s-to 0.25g lyazine Victoria Pure Blue BOH 0.01g crystal violet 0.01g 2- (p-methoxystyryl) -4,6-bis (trichloromethe 0.03g tyl) -S-triazine ethylene dichloride 16 g 2-methoxyethyl acetate 12 g The photosensitive coating solution having the above composition is electrochemically roughened,
And applied to an anodized aluminum plate. The film weight after drying at this time was 2.3 g / m ² . The thus obtained photosensitive plate was examined for optimum exposure time and development tolerance in the same manner as in the examples. As a result, the optimum exposure time was 60 seconds and the development tolerance was 7 minutes. When the printing plate obtained as described above was printed using an offset printing machine, a large number of prints with good images were obtained. Examples 5 and 6 and Comparative Example f The aluminum plate used in Example 1 was coated with the following photosensitive solution (Table 3).
See Examples 5 and 6 and Comparative Example f, applied 100
After drying at 5 ° C for 5 minutes, positive photosensitive printing plates 5 and 6 and Comparative Example f were obtained. The coating amount after drying is 2.3 to 2.4 g / m
^{Was 2} . The sensitivity (exposure time) and the development acceptability of these positive-type photosensitive printing plates were measured in the same manner as in Example 1. The results are shown in Table 4. It can be seen from Table 4 that the photosensitive printing plates of the present invention (Examples 5 and 6) show an improvement in sensitivity as compared with Comparative Example f, and the development acceptability is within a range not causing a problem in practical use. I understand.

[Table 3]

[0028]

[Chemical 4]

[0029]

[Table 4] Table 4 Performance evaluation table ────────────────────────────── Sensitivity (exposure time) Development tolerance ─── ─────────────────────────── Example 4 55 seconds 7 minutes Example 5 55 seconds 7 minutes Comparative Example f 70 seconds 8 minutes ── ────────────────────────────

Claims (1)

[Claims] 1. A positive photosensitive composition for a printing plate, which comprises an o-quinonediazide compound or a diazonium salt,
A positive photosensitive composition for a printing plate, comprising a compound represented by the following general formula (I). [Chemical 1] Here, R _{1 to} R ₅ are hydrogen atom, hydroxyl group, halogen atom,
It represents an alkyl group, an alkoxy group or an alkenyl group, and may be the same or different. However, R ₁ ~
At least one of R ₅ is a hydroxyl group.