JPH05297573A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To provide a photosensitive planographic printing plate giving a satisfactory visible image by exposure and having satisfactory under-developability and high sensitivity. CONSTITUTION:The surface of a pretreated substrate is treated with an aq. soln. contg. nitrous acid or a nitrate and a photosensitive layer contg. An o- quinonediazido compd., an alkali-soluble binder, an s-triazine compd. which generates an acid or a free radical when irradiated with active light and an alterant which alters its color tone by interaction with the s-triazine compd. is formed on the treated surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate, and more particularly to a highly sensitive photosensitive lithographic printing plate which has good visibility and underdeveloping property upon exposure.

[0002]

BACKGROUND OF THE INVENTION In order to facilitate alignment between film originals, such as when performing so-called "multi-sided printing" in which a plurality of film originals are printed one after another at different positions on a photosensitive lithographic printing plate, the exposure area and It is necessary that the exposed parts can be distinguished. That is, a visible image is formed by exposure,
It is necessary that the so-called exposure visibility is excellent.
Further, it is required to have high sensitivity from the viewpoint of shortening the printing time, and to have excellent so-called under-developing property from the viewpoint of preventing contamination of non-image area during printing. That is, the development processing of a positive type photosensitive lithographic printing plate is usually carried out in a developing solution containing an alkaline aqueous solution, but the developing ability of the developing solution is easily affected by various conditions. In some cases, the photosensitive layer in the non-image area of the printing plate may not be completely dissolved even if it is processed, due to deterioration in developing ability due to deterioration. For this reason, it is desired that the photosensitive lithographic printing plate has a wide range of development acceptability that exhibits the same developability as in the case of processing with a standard developing solution, even with a developing solution having a lowered processing ability as described above. The permissible range of the decrease in the developing ability at which such an appropriate developing result is obtained is called underdeveloping property.

[0003]

SUMMARY OF THE INVENTION In order to impart an exposure visible image property, a photosensitive composition used for a photosensitive lithographic printing plate generally contains a printout material for forming a visible image by exposure. As the printout material, a compound that generates an acid or a free radical upon exposure to light,
It is composed of a dye that changes the color tone by interacting with it. For example, JP-A-53-36223 and JP-A-54-74728.
However, the visible image visibility of the photosensitive lithographic printing plate using such a printout material is still insufficient.

The exposure visibility is usually improved with an increase in the amount of such a compound added. On the other hand, if the amount added is too large, the sensitivity of the photosensitive lithographic printing plate may decrease. It has drawbacks such as a decrease in alkali solubility and deterioration of underdeveloping property. Particularly in recent years, since the exposure amount to the photosensitive lithographic printing plate tends to be reduced, it is necessary to add a large amount of such a compound in order to improve the visibility of exposure image, but the above-mentioned adverse effects are caused. It was a problem because it would occur.

As a means for improving underdeveloping property, a method of subjecting a support to a surface treatment is known. For example, Japanese Patent Application Laid-Open No. 2-158738 discloses a technique of treating with an aqueous solution containing one or both of nitric acid and nitrate.
Japanese Patent Laid-Open No. 2-289388 discloses a technique of treating with an aqueous solution containing nitrous acid or a nitrite, but the present situation is that sufficient underdeveloping property is not obtained yet.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a photosensitive lithographic printing plate having a good visible image property of exposure, a high sensitivity and an excellent under-developing property. To provide.

[0007]

The object of the present invention is to treat the surface of a pretreated support with an aqueous solution containing nitrous acid or a nitrite, and then add an orthoquinonediazide compound to the surface.
A photosensitive layer containing an alkali-soluble binder, an s-triazine compound that generates an acid or a free radical upon irradiation with actinic rays, and a color-changing agent that changes its color tone by interacting with the s-triazine compound. Is achieved by a photosensitive lithographic printing plate.

The present invention will be described in more detail below.

The s-triazine compound used in the present invention which forms an acid or a free radical upon irradiation with actinic rays is not particularly limited, but compounds having the structures represented by the following general formulas (I) to (IV) are available. It is preferably used.

[0010]

[Chemical 1] [In the formula, R ₁ , R ₂ and R ₆ each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxy group or a substituted alkoxy group, and R ₃ is a haloalkyl group having 1 to 3 carbon atoms. Or represents a haloalkenyl group,
R ₄ and R ₅ each represent a hydrogen atom, a halogen group, an alkyl group or a substituted alkyl group, R ₇ represents an alkyl group,
It represents a substituted alkyl group, an aryl group or a substituted aryl group. X represents O or S, m represents 1 or 2, n
Represents 0 or 1. ]

Of these, compounds having a structure represented by the general formula (II), (III) or (IV) are preferably used in the present invention.

S represented by the above general formulas (I) to (IV)
The triazine-based compound can be obtained by a known method described in, for example, JP-A No. 50-36209. Specifically, 2,4-bis (halomethyl) -6- (substituted) alkyl-s-triazine or 2,4-bis (halomethyl)-
It is obtained by condensing a 6- (substituted) aryl-s-triazine with the corresponding aromatic (heterocyclic) aldehyde.

Suitable aldehydes include p-methoxybenzaldehyde, p-ethoxybenzaldehyde and p-ethoxybenzaldehyde.
-Propoxybenzaldehyde, p-butoxybenzaldehyde, p-pentoxybenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde,
p-propylbenzaldehyde, p-butylbenzaldehyde, p-pentylbenzaldehyde, m-methoxybenzaldehyde, m-ethoxybenzaldehyde, m
-Propoxybenzaldehyde, m-butoxybenzaldehyde, m-pentoxybenzaldehyde, m-methylbenzaldehyde, m-ethylbenzaldehyde,
m-Propylbenzaldehyde, m-butylbenzaldehyde, m-pentylbenzaldehyde, m-, p-dimethoxybenzaldehyde, m-, p-diethoxybenzaldehyde, m-, p-dipropoxybenzaldehyde, m-, p-dibutoxybenzaldehyde , M-,
p-dipentoxybenzaldehyde, m-, p-dimethylbenzaldehyde, m-, p-diethylbenzaldehyde, m-, p-dipropylbenzaldehyde, m-,
p-dibutylbenzaldehyde, m-, p-dipentoxybenzaldehyde, 3,5-dimethoxybenzaldehyde, 2-thiophenaldehyde, 3-methyl-2-thiophenaldehyde, 5-bromo-2-thiophenaldehyde, 2-furylaldehyde, Examples thereof include 3- (2-furyl) acrolein.

Specific examples of s-triazine compounds preferably used in the present invention are shown below, but the present invention is not limited thereto.

[0015]

[Chemical 2]

[0016]

[Chemical 3]

[0017]

[Chemical 4]

[0018]

[Chemical 5]

[0019]

[Chemical 6]

[0020]

[Chemical 7] The s-triazine compound according to the present invention is contained in the photosensitive layer in an amount of 0.005.
It is preferable that the content is -20% by weight, more preferably 0.05-15.
It is preferably contained in a weight percentage.

In the present invention, as long as the effect of the present invention is not impaired, other trihaloalkyl as a compound which generates an acid or a free radical upon irradiation with an actinic ray in combination with the s-triazine compound according to the present invention. A compound or diazonium salt compound can be used.

In the present invention, the s-
A color-changing agent that changes the color tone of the triazine-based compound by interacting with the photolysis product of the triazine-based compound can be contained. There are two types of such discoloring agents, one that develops color and the other that discolors or discolors. As the discoloring agent that discolors or discolors, various dyes such as diphenylmethane, triphenylmethane-based thiazine, oxazine-based, xanthene-based, anthraquinone-based, iminonaphthoquinone-based, and azomethine-based dyes are effectively used.

Specific examples of these are as follows. Ie Brilliant Green,
Eosin, ethyl violet, erythrosine B, methyl green, crystal violet, basic fuchsin, phenolphthalein, 1,3-diphenyltriazine, alizarin red S, thymolphthalein, methyl violet 2B, quinaldine red, rose bengal, metanil yellow , Thymol sulfophthalein,
Xylenol blue, methyl orange, orange IV, diphenylthiocarbazone, 2,7-dichlorofluorescein, paramethyl red, congo red, benzopurpurin 4B, α-naphthyl red, Nile blue 2B,
Nile blue A, phenacetaline, methyl violet, malachite green, parafuchsin, Victoria pure blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), oil blue # 603 (manufactured by Orient Chemical Industry Co., Ltd.), oil pink # 312 (Orient Chemical Industry ( Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Chemical Co., Ltd.]
Made], Oil Red OG [Orient Chemical Industry Co., Ltd.
Made], Oil Red RR [Orient Chemical Industry Co., Ltd.
], Oil Green # 502 [manufactured by Orient Chemical Industry Co., Ltd.], Spiron Red BEH Special [manufactured by Hodogaya Chemical Industry Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, first acid violet R, Sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p-diethylaminophenyliminonaphthoquinone, 2-carbostearylamino-4-p-dihydrooxyethylamino-phenyliminonaphthoquinone, p -Methoxybenzoyl-
p'-diethylamino-o'-methylphenyliminoacetanilide, cyano-p-diethylaminophenyliminoacetanilide, 1-phenyl-3-methyl-4-
p-diethylaminophenylimino-5-pyrazolone,
1-β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone and the like.

Further, arylamines can be used as the color-changing agent that develops color. Aryl amines suitable for this purpose include so-called leuco dyes in addition to simple aryl amines such as primary and secondary aromatic amines, and examples thereof include the following.

Diphenylamine, dibenzylaniline,
Triphenylamine, diethylaniline, diphenyl-
p-phenylenediamine, p-toluidine, 4,4'-
Biphenyldiamine, o-chloroaniline, o-bromoaniline, 4-chloro-o-phenylenediamine, o-
Bromo-N, N-dimethylaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminediphenylmethane, aniline, 2,5-dichloroaniline, N
-Methyldiphenylamine, o-toluidine, p, p '
-Tetramethyldiaminodiphenylmethane, N, N-dimethyl-p-phenylenediamine, 1,2-dianilinoethylene, p, p ', p "-hexamethyltriaminotriphenylmethane, p, p'-tetramethyldiaminotriamine Phenylmethane, p, p'-tetramethyldiaminodiphenylmethylimine, p, p ', p "-triamino-
o-methyltriphenylmethane, p, p ′, p ″ -triaminotriphenylcarbinol, p, p′-tetramethylaminodiphenyl-4-anilinonaphthylmethane,
p, p ', p "-triaminotriphenylmethane, p,
p ', p "-hexapropyltriaminotriphenylmethane.

The proportion of the above color changing agent in the photosensitive layer is
It is preferably 0.01 to 10% by weight, more preferably 0.05 to 10% by weight.

The photosensitive layer constituting the photosensitive lithographic printing plate of the present invention contains an orthoquinonediazide compound, and various known compounds can be used in the present invention.
An o-naphthoquinonediazide compound is particularly preferably used.

As the o-naphthoquinonediazide compound used in the present invention, for example, an ester compound of o-naphthoquinonediazide sulfonic acid and a polycondensation resin of phenol and aldehyde or ketone is preferably used.

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

Specific examples of the polycondensation resin include phenol-formaldehyde resin, p-cresol-formaldehyde resin, m-cresol-formaldehyde resin, m- and p-mixed cresol-formaldehyde resin, resorcin-benzaldehyde resin, Examples include pyrogallol / acetone resin.

The condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol of the o-naphthoquinonediazide compound (reaction rate for one OH group) is
15 to 80% is preferable, and 20 to 60% is more preferable.
Is.

Further, as the o-naphthoquinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be used. That is, for example, known 1,2-quinonediazide compounds such as 1,2-naphthoquinonediazidesulfonic acid ester and 1,2-naphthoquinonediazidesulfonic acid amide, more specifically, J. Kosar's "Light Sensitive" Systems "(" Light-Se
"Native Systems") No. 339-352
Page (1965), "Photoresist" by John Willy & Sons (New York) and W. S. De Forest.
("Photoresist") Volume 50, (1975
1), 2-naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1-, described in McGraw-Hill, Inc. (New York).
(1,2-naphthoquinonediazide-5-sulfonyl)-
3,5-dimethylpyrazole, 1,2-naphthoquinonediazide-5-sulfonic acid-4 ″ -hydroxydiphenyl-4 ″ -azo-β-naphthol ester, N, N-di-
(1,2-naphthoxynone diazide-5-sulfonyl)
-Aniline, 2 '-(1,2-naphthoquinonediazide-
5-sulfonyloxy) -1-hydroxy-anthraquinone, 1,2-naphthoquinonediazide-5-sulfonic acid-2,4-dihydroxybenzophenone ester, 1,
2-naphthoquinonediazide-5-sulfonic acid-2,3
4-trihydroxybenzophenone ester, 1,2-
A condensate of 2 mol of naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of 4,4'-diaminobenzophenone,
Condensation product of 2 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of 4,4'-dihydroxy-1,1'-diphenylsulfone, 1 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride Condensate of 1 mol of purpurogallin, 1,2-naphthoquinonediazide-5
An example is a 1,2-quinonediazide compound such as-(N-dihydroabietyl) -sulfonamide. In addition, Japanese Examined Japanese Patent Publication Nos. 37-1953 and 37-3627.
Nos. 37-13109, 40-26126, 40-3801, 45-5604, 45-27.
No. 345, No. 51-13013, JP-A-48-965.
The 1,2-quinonediazide compounds described in Japanese Patent Nos. 75, 48-63802 and 48-63803 can also be mentioned.

Further, as the o-naphthoquinonediazide compound used in the present invention, for example, 1,2-naphthoquinonediazide-4-sulfonic acid cyclohexyl ester, 1
-(1,2-naphthoquinonediazide-4-sulfonyl)
-3,5-Dimethylpyrazole, 1,2-naphthoquinonediazide-4-sulfonic acid-4 "-hydroxydiphenyl-4" -azo-β-naphthol ester, 2'-
(1,2-naphthoquinodiazide-4-sulfonyloxy) -1-hydroxy-anthraquinone, 1,2-naphthoquinonediazide-4-sulfonic acid-2,4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-4 -Sulfonic acid-2,3,4-trihydroxybenzophenone ester, 1,2-naphthoquinonediazide-4-sulfonic acid-2,3,4 ', 4'-tetrahydroxybenzophenone ester, 1,2-naphthoquinonediazide-4 -2 mol of sulfonic acid chloride and 4,4'-
1,2-naphthoquinone-2-, a polyhydroxy compound such as a condensate of 1 mol of dihydroxy-1,1'-diphenylsulfone, a condensate of 1 mol of 1,2-naphthoquinonediazide-4-sulfonic acid chloride and 1 mol of purpurogallin Examples thereof include diazide-4-sulfonic acid ester compounds.

Further, the following o-naphthoquinonediazide sulfonic acid ester compounds of polyurethane resin may be used.

[0035]

[Chemical 8]

In the present invention, an ester compound of a vinyl polymer having a phenolic hydroxyl group and o-naphthoquinonediazide sulfonic acid can be used as the o-naphthoquinonediazide compound. The vinyl polymer having a phenolic hydroxyl group forming such an ester compound is a polymer having a unit having a phenolic hydroxyl group in its molecular structure, and preferably a phenolic hydroxyl group used as an alkali-soluble resin described below. The same thing as the vinyl polymer which has the structural unit which it has in a molecular structure is used.

As the orthoquinonediazide compound used in the present invention, the above compounds may be used alone or in combination of two or more kinds. The ratio of the orthoquinonediazide compound used in the present invention in the photosensitive layer is preferably 5 to 60% by weight, particularly preferably 5%.
~ 50% by weight.

An alkali-soluble binder is used in the photosensitive layer. As such a binder, various binders known in the art can be used.
Particularly, a novolak resin and a vinyl polymer having a structural unit having a phenolic hydroxyl group in the molecular structure are preferable.

Examples of the novolac 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, o-cresol, m-cresol. , P-cresol, 3,5-xylenol, 2,
4-xylenol, 2,5-xylenol, carvacrol, thymol, catechol, resorcin, hydroquinone, pyrogallol, phloroglucin and the like can be mentioned. The above phenol compounds may be used alone or in combination of two or more to condense with formaldehyde to obtain a resin.
Of these, preferred novolac resins are phenol,
A resin obtained by copolycondensing at least one selected from m-cresol (or o-cresol) and p-cresol with formaldehyde, for example, phenol-formaldehyde resin, m-cresol-formaldehyde resin, o- Cresol / formaldehyde resin, phenol / p-cresol / formaldehyde copolymer resin, m-cresol / p-cresol / formaldehyde copolycondensate resin, o-cresol / p-cresol / formaldehyde copolycondensate resin, phenol / m -Cresol / p-cresol / formaldehyde copolycondensate resin and phenol / o-cresol / p-cresol / formaldehyde copolycondensate resin may be mentioned. Further, among the above novolac resins, phenol / m
-Cresol / p-cresol / formaldehyde resin is preferred.

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

As for the molecular weight (polystyrene standard) of the above novolak resin, the weight average molecular weight Mw is 2.0 × 10.
^{3 to} 2.0 × 10 ⁴ and number average molecular weight Mn of 7.0 × 1
The value is preferably in the range of 0 ^{2 to} 5.0 × 10 ³ , and more preferably Mw is 3.0 × 10 ^{3 to} 6.0.
× 10 ³ and Mn are values in 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 method).

The vinyl polymer having a structural unit having a phenolic hydroxyl group, which is preferably used in the present invention, in the molecular structure is a polymer obtained by the cleavage of a carbon-carbon double bond and polymerization. Yes General formula [a] ~
A polymer containing at least one structural unit of [f] is preferably used.

[0043]

[Chemical 9] In the formula, R ₁ and R ₂ each represent a hydrogen atom, an alkyl group, or a carboxyl group, and preferably a hydrogen atom. R ₃ 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. R ₄ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and preferably a hydrogen atom. A represents an alkylene group which may have a substituent which connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer of 0 to 10, and B represents phenylene which may have a substituent. Represents a naphthylene group which may have a group or a substituent. In the present invention, among these, a copolymer containing at least one structural unit represented by the above general formula [b] is preferable.

The vinyl-based polymer preferably has a copolymer type structure, and in such a copolymer, the structural unit represented by each of the general formulas [A] to [F] can be used. Examples of the monomer unit that can be used in combination with at least one kind include ethylenically unsaturated olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene, for example, styrene, α-methylstyrene, p-methylstyrene, p -Styrenes such as chlorostyrene, acrylic acids such as acrylic acid and methacrylic acid, unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid and maleic anhydride, such as methyl acrylate, ethyl acrylate, acrylic acid n -Butyl, isobutyl acrylate, dodecyl acrylate, 2-chloroethane acrylate , Phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, ethyl ethacrylic acid and other α-methylene aliphatic monocarboxylic acid esters such as acrylonitrile, methacrylonitrile and other nitriles such as acrylamide. Amides such as acrylic anilide, p
-Chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, and other anilides, such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, and other vinyl esters, such as methyl vinyl ether, ethyl vinyl ether, and isobutyl vinyl ether. , Vinyl ethers such as β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, for example, 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxy. Carbonyl ethylene, ethylene derivatives such as 1-methyl-1-nitroethylene, such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidene,
There are vinyl monomers such as N-vinyl compounds such as N-vinylpyrrolidone. These vinyl monomers have a structure in which unsaturated double bonds are cleaved and are present in the polymer compound.

Of the above monomers, the general formulas [a] to
(Meth) acrylic acids, esters of aliphatic monocarboxylic acids, and nitriles are preferable as the ones to be used in combination with at least one structural unit represented by [f], because they show comprehensively excellent performance. More preferred are methacrylic acid, methyl methacrylate, acrylonitrile, ethyl acrylate and the like.

These monomers may be bound to the vinyl polymer in a block or random state.

The content of the structural unit represented by each of the general formulas [A] to [F] in the vinyl polymer is preferably 5 to 70 mol%, particularly preferably 10 to 40 mol%.

The above-mentioned polymers may be used alone, or may be used in combination of two or more kinds in the photosensitive composition.

Typical specific examples of the vinyl polymer used in the present invention will be given below. In the compounds exemplified below, Mw is a weight average molecular weight, Mn is a number average molecular weight,
s, k, l, o, m and n each represent mol% of the structural unit.

[0050]

[Chemical 10]

[0051]

[Chemical 11]

[0052]

[Chemical 12]

[0053]

[Chemical 13]

[0054]

[Chemical 14]

The proportion of the alkali-soluble binder in the photosensitive layer is preferably 40 to 95% by weight, more preferably 50 to 95% by weight.

In the present invention, the photosensitive layer may further contain an organic acid and an acid anhydride, if necessary.

As the organic acid used in the present invention, all known various organic acids can be used, but an organic acid having a pKa value of 2 or more is preferable, and more preferably a pKa value of 3.
It is 0 to 9.0, and particularly preferably 3.5 to 8.0 organic acid is used. However, the pKa value used in the present invention is the value at 25 ° C.

As such an organic acid, for example, Chemical Handbook Basic Edition II (Maruzen Co., Ltd., 1966, Nos. 1054 to 10).
The organic acids described on page 58) may include all compounds capable of exhibiting the above pKa value. Examples of such compounds include benzoic acid, adipic acid, azelaic acid, isophthalic acid, p-toluic acid, q-toluic acid, β-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, sebacic 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, dimethylmalonic acid, α-
Tartaric acid, speric 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, methylmalon Acid, malic acid, 1,1-cyclohexanedicarboxylic acid,
1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, erucic acid, undecenoic acid, lauric acid, n-capric acid , Pelargonic acid, n-undecanoic acid and the like. In addition, organic acids having an enol structure such as Meldrum's acid and ascorbic acid can also be preferably used. The ratio of the above organic acid in the photosensitive layer is 0.05.
-15% by weight is preferable, and 0.1-10 is more preferable.
% By weight.

As the acid anhydride used in the present invention, all known various acid anhydrides can be used, but cyclic acid anhydrides are preferable, and examples thereof include phthalic anhydride and tetrahydrophthalic anhydride. , Hexahydrophthalic anhydride, 3,6-endooxy-Δ ⁴ -tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, glutaric anhydride, maleic anhydride, chloromaleic anhydride, α-
Examples thereof include phenyl maleic anhydride, succinic anhydride, and pyromellitic acid. These acid anhydrides are contained in the photosensitive layer in an amount of 0.
It is preferably contained in an amount of 05 to 15% by weight, particularly 0.1
It is preferable to contain 10 to 10% by weight.

In the present invention, in the photosensitive layer, in addition to the above, a sensitizer, a plasticizer, an inorganic acid, and if necessary, JP-A-2-9676.
The surfactant described in No. 0, the oil-sensitizing agent described in JP-A-2-96164 and the like can be added.

In the present invention, the photosensitive lithographic printing plate of the present invention can be obtained by dissolving each of the above-mentioned components in a solvent, coating the surface of a suitable support and drying the solution to form a photosensitive layer. ..

Solvents that can be used when dissolving each of the above components include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate; methyl carbitol, ethyl carbitol, dimethyl carbitol, diethyl. Diethylene glycol ethers and / or esters such as carbitol and methyl carbitol acetate; dimethylformamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, methyl ethyl ketone and the like. These solvents may be used alone or in combination of two or more.

In the present invention, the coating solution for the photosensitive layer is coated on a support surface.
As a coating method used for coating the surface, a conventionally known method is used.
Method, eg spin coating, wire bar coating, dip
Coating, air knife coating, roll coating, blade coating and
And curtain coating are possible. At this time, the coating amount depends on the application
Although different, for example, the solid content is 0.5 to 5.0 g /
m ² Is preferred.

As the support used in the photosensitive lithographic printing plate of the present invention, metal plates such as aluminum, zinc, steel and copper, and chromium, zinc, copper, nickel, aluminum and iron are plated or vapor-deposited. Examples thereof include metal plates, papers, plastic films and glass plates, papers coated with resin, papers coated with a metal foil such as aluminum, and plastic films that have been hydrophilized. Among these, an aluminum plate is preferable. The support used in the present invention is subjected to surface treatment such as graining treatment, anodic oxidation treatment and, if necessary, sealing treatment.

A known method can be applied to these treatments.

Examples of the graining method include a mechanical method and an electrolytic etching method. Examples of the mechanical method include a ball polishing method, a brush polishing method, a liquid honing polishing method, and a buff polishing method. The above-mentioned various methods can be used alone or in combination depending on the composition of the aluminum material. The method by electrolytic etching is preferable.

Electrolytic etching is performed using phosphoric acid, sulfuric acid, hydrochloric acid,
It is carried out in a bath containing an inorganic acid such as nitric acid or a mixture of two or more kinds. After the graining treatment, if necessary, desmut treatment is performed with an aqueous solution of alkali or acid to neutralize and wash with water.

The anodic oxidation treatment is carried out by using sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc. as the electrolytic solution in one kind or in two kinds.
It is carried out by electrolysis using a solution containing at least one species and using an aluminum plate as an anode. The amount of anodized film formed is 1 to 5
0 mg / dm ² is suitable, preferably 10-40 m
It is g / dm ² . The amount of the anodic oxide film is, for example, that of an aluminum plate containing a phosphoric acid chromic acid solution (phosphoric acid 85% solution: 35
ml, chromium oxide (VI): 20 g dissolved in 1 liter of water) to dissolve the oxide film, and the weight change before and after film dissolution of the plate is measured.

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

In the present invention, before providing the photosensitive layer on the surface of the support pretreated as described above, the surface is treated with an aqueous solution containing nitrite.

Examples of these nitrites include the periodic table.
Ia, IIa, IIb, IIIb, IVa, IVb, VIa, VII
a and VIII metal nitrite or ammonium salts,
That is, ammonium nitrite can be mentioned, and its metal salt
Then, for example, LiNO₂, NaNO₂ , KNO₂ ，
Mg (NO₂ )₂ , Ca (NO₂ )₂ , Zn (NO₂) ₂
 , Al (NO₂ )₃ , Zr (NO₂ )_Four , Sn (NO₂
 )_Four , Cr (NO₂)₃ , Co (NO₂ )₂ , Mn (N
O₂ )₂ , Ni (NO₂ )₂ And the like, especially
Potassium metal nitrite is preferred. Such nitrites are
Of course, two or more sets can be used together, and it can be used together with nitrous acid.
You can also do it. In the present invention, nitrite is these
Generally, 0.001 to 1.0% by weight is contained in an aqueous solution containing
It is preferable to be included.

The treatment conditions for treating the surface of the support with the above-mentioned treatment solution are: room temperature to about 100 ° C.
Immerse the pretreated support for 10 to 300 seconds, or
Alternatively, it is preferable to apply the treatment liquid to the support.

The photosensitive lithographic printing plate of the present invention can be developed by a usual method. For example, it is exposed through a transparent positive film with a light source such as an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, etc., and subsequently, developed with various alkaline developers. As a result, only the unexposed portion remains on the surface of the support, and a positive-positive relief image is formed.

Examples of the alkali developer include alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, and tribasic sodium phosphate. An aqueous solution of The concentration of the alkali metal salt is preferably 0.1 to 10% by weight. Further, an organic solvent such as an anionic surfactant, an amphoteric surfactant or alcohol can be added to the developing solution, if necessary.

[0075]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Example 1 [Production of Aluminum Plate-1] An aluminum plate having a thickness of 0.24 mm (material 1050, temper H16) was added at 5% by weight.
After degreasing treatment at 60 ° C. for 1 minute in an aqueous sodium hydroxide solution, electrolysis is performed in 1 liter of 0.5 molar hydrochloric acid aqueous solution at a temperature of 25 ° C., a current density of 60 A / dm ² , and a treatment time of 30 seconds. An etching process was performed. Then 5
After desmutting treatment at 60 ° C. for 10 seconds in a weight% sodium hydroxide aqueous solution, in a 20 weight% sulfuric acid solution,
Anodizing treatment was performed under the conditions of a temperature of 20 ° C., a current density of 3 A / dm ² , and a treatment time of 1 minute. Furthermore, with hot water of 80 ° C, 20
A hot water sealing treatment was performed for 2 seconds to prepare an aluminum plate-1 as a lithographic printing plate support.

[Production of Aluminum Plate-2] The obtained aluminum plate-1 was immersed in an aqueous solution containing 0.5% by weight of sodium nitrite at 80 ° C. for 10 seconds, washed with water and dried to form an aluminum plate-2. Obtained.

[Application of Photosensitive Composition Coating Liquid] The aluminum plate-2 prepared as described above was coated with a photosensitive composition coating liquid having the following composition using a spin coater and dried at 90 ° C. for 4 minutes. A positive photosensitive lithographic printing plate (Sample No. 1) was prepared. The dry coating film thickness of this sample was 2.2 g / m ² . Photosensitive composition coating liquid composition (1) o-naphthoquinonediazide compound (QD-1) 3.5 g (2) novolac resin NB-1 8.5 g (3) non-novolak resin (PH-1) 2.0 g (4) halomethyl- s-Triazine compound 0.12g (5) Dye (Victoria Pure Blue BOH) (Hodogaya Chemical Co., Ltd.) 0.12g (6) Surfactant (S-381) (Asahi Glass Co., Ltd.) 0.04g (7) cis-4 -Cyclohexene-1,4-dicarboxylic acid 0.30 g (8) sulfuric acid 0.03 g (9) methyl cellosolve 85 g

[0079]

[Chemical 15] NB-1 Phenol, m-cresol, p-cresol and formaldehyde copolymer compound (the molar ratio of each of phenol, m-cresol and p-cresol is 5:57:38,
(Mw = 4000)

Preparation of Sample No. 1 except that (4) the halomethyl-s-triazine compound of the photosensitive composition coating solution and the aluminum plate-2 coated with the coating solution were replaced as shown in Table 1. Similarly, a photosensitive lithographic printing plate sample No.
2 to 12 were produced respectively.

With respect to each of the obtained samples No. 1 to 12, the sensitivity, the underdeveloping property and the exposure visible image property were evaluated by the following methods.

<Evaluation of Sensitivity and Underdeveloping Property> Each of the obtained photosensitive lithographic printing plate samples No. 1 to 12 was subjected to a sensitivity measuring step tablet (No. 2, manufactured by Eastman Kodak Co., density difference of 0. 21 steps of gray scale (15 steps each) were brought into close contact with each other and exposed from a distance of 90 cm using a 4 KW metal halide lamp (VIO QUICK 4000 manufactured by Dainippon Screen Mfg. Co., Ltd.) as a light source. Next, this sample was developed for 20 seconds at 27 ° C. with a developer obtained by diluting SDR-1 (manufactured by Konica Corp.) developer 6 times with water.

The sensitivity was defined as the exposure time at which the 3.0 step of the step tablet was completely cleared.

Further, the above SDR-1 developing solution was developed with a developing solution diluted 10 times with water, a developing solution diluted 11 times and a developing solution diluted 12 times, respectively, and developed at 27 ° C. for 20 seconds. For the lithographic printing plate sample obtained by the above, the mark five red ink (Toyo Ink Co., Ltd.)
Was used to conduct a printing test, and the degree of coloration of halftone dots in the shadow portion was visually evaluated to evaluate the developability (underdeveloping property) for a developer having a reduced developing ability.

<Evaluation of Visibility of Exposure Visibility> The difference in density between exposed and unexposed portions of the sample before development which was similarly exposed under the above conditions was visually evaluated under a yellow light to evaluate the visibility of exposure. Further, measurement was performed using a densitometer (Konica Densitometer PDA-65) to obtain an absolute value ΔD of the density difference between the exposed portion and the unexposed portion. The larger the ΔD, the better the exposure visibility.

Table 2 shows the results of the above evaluations.

[0087]

[Table 1]

[0088]

[Table 2]

[0089]

[Table 3] * 1 Under-development ◎ When there is no dark spots in the shadow area,
The case in which the karami was remarkable was marked as XX and the interval was divided into 5 grades for evaluation. In other words, no larami ← ◎, ○, △, ×, × × → significant coloration * 2 Visibility of exposed light (visual) Very good visibility of exposed light (exposed part and unexposed part are very clearly distinguished) The state in which it is possible) is ⊚, and the state in which there is no visible image property of exposure (the state in which the exposed portion and the unexposed portion are completely indistinguishable) is set as XX.
That is, the exposure visibility is good ← ◎, ○, △, ×, XX → Exposure visibility is poor

From the results shown in Table 2, it can be seen that the photosensitive lithographic printing plate of the present invention has good exposure and visibility, high sensitivity and good under-developing property.

[0091]

As described above in detail, according to the present invention, it is possible to provide a photosensitive lithographic printing plate having good exposure visibility and underdeveloping property and high sensitivity.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinichi Matsubara, 1 Sakura-cho, Hino-shi, Tokyo Konica Co., Ltd. (72) Masahisa Murata 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor Mitsuru Sasaki 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd.Institute of Research (72) Naruo Tsuji 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd. In-house

Claims (1)

[Claims] 1. A surface of a pretreated support is treated with an aqueous solution containing nitrous acid or a nitrite, and then an orthoquinonediazide compound, an alkali-soluble binder, and irradiation with an actinic ray generate an acid or a free radical. A photosensitive lithographic printing plate comprising a photosensitive layer containing an s-triazine compound and a color-changing agent that changes its color tone by interacting with the s-triazine compound.