JPH04328553A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To obtain photosensitive composition for photosensitive lithographic printing plate having an excellent exposure visible picture property even at lowly illuminant exposure by incorporating dyestuff having a specified structure. CONSTITUTION:This photosensitive composition is incorporated a dyestuff having a structure shown in formula 1. In formula 1, R1 or R2 is hydrogen atom or alkyl group having >=2C, R3-R6 are alkyl group, alkoxyl group, aryl group, or heterocyclic group which has >=3C and may be same or different each other when at least one of R1 and R2 is hydrogen atom, and are alkyl group, alkoxyl group, aryl group or heterocyclic group which has >=2C and may be same or different each other when both of R1 and R2 are alkyl group having >=2C, and X<-> is anion of an inorganic acid or an organic acid.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition for use in a photosensitive lithographic printing plate, and more particularly to a photosensitive composition for a photosensitive lithographic printing plate containing a novel exposure-visible image agent.

0002

[Prior Art] When performing so-called "multi-sided printing" in which multiple film originals are printed one after another on a photosensitive lithographic printing plate, the exposure area and unmarked area are It is necessary that the exposed areas can be distinguished. For this reason, the photosensitive composition used in the photosensitive lithographic printing plate generally contains a printout material for forming a visible image by exposure (hereinafter referred to as "visible imageability"). The printout material consists of a compound that generates acids or free radicals when exposed to light, and a dye that changes color tone by interacting with this compound. Conventionally, compounds that generate acids or free radicals when exposed to light are Examples include halomethyl-vinyl-oxadiazole compounds described in Japanese Patent Publication No. 61-51788 and the like. Examples of dyes whose color tone changes with acids or free radicals generated by exposure to light include triphenylmethane dyes with a specific structure described in JP-A No. 55-48749 and the like.

[0003] However, conventionally known dyes cannot be said to have sufficient exposure visibility during low-intensity exposure. Nowadays, the sensitivity of photosensitive materials has become higher and lower light exposure is becoming necessary, and working efficiency is poor due to low light exposure for pasting marks, high dot ratio originals, and overlapping parts of originals during multi-sided printing. However, there are problems such as insufficient exposure. Therefore, it has been desired to develop a photosensitive lithographic printing plate that has excellent exposed visible image properties even during low-light exposure.

0004

SUMMARY OF THE INVENTION That is, an object of the present invention is to provide a photosensitive composition suitable for a photosensitive lithographic printing plate that has excellent exposure visible image properties even when exposed to low illuminance.

[0005]

[Means for Solving the Problems] In view of the above-mentioned problems, the present inventors have conducted extensive research and found that the above-mentioned object of the present invention is to provide a dye having a structure represented by the following general formula [I] (hereinafter referred to as "the present invention"). It has been found that this can be achieved by providing a photosensitive composition containing a dye.

[0006]

[Formula 2] Here, R1 and R2 are hydrogen atoms or have 2 carbon atoms.
R3 to R6 represent R1, R2 or more.
represents an alkyl group, alkoxy group, aryl group, or heterocyclic group having 3 or more carbon atoms, which may be the same or different, and both R1 and R2 have a carbon atom number. In the case of two or more alkyl groups, each represents an alkyl group, an alkoxy group, an aryl group, or a heterocyclic group having two or more carbon atoms, which may be the same or different, and X- represents an inorganic or organic acid. Represents an anion.

The present invention will be explained in detail below.

In the above general formula [I], R1 and R2 are preferably an alkyl group having 2 or more carbon atoms, particularly preferably at least one is a t-butyl group, and R3 to R6 are at least Preferably, one is a t-butyl group or an alkoxy group.

The dye of the present invention is preferably contained in the photosensitive composition in an amount of 0.01 to 30% by weight, more preferably 0.05% by weight.
Contains ~15% by weight.

Typical examples of the dyes of the present invention are shown below, but the present invention is not limited thereto.

[0011]

[Chemical formula 3]

0012

[C4]

[0013]

[C5]

[0014]

embedded image These exemplified compounds can be easily synthesized, for example, by the method described in Yutaka Hosoda, “Shin Dye Kagaku” (1963), Gihodo Co., Ltd. Next, a synthesis example will be shown.

Exemplary compound No. 200 g of phosgene liquid was added to 1230 g of synthetic diethylaniline in 1 below 15°C, 70 g of AlCl was added in two portions below 30°C, and the mixture was heated at 30°C for 3 hours, at 50°C for 12 hours, and at 70°C for 12 hours.
The mixture was heated at 80° C. for 12 hours.

The reaction product was cooled to 65°C, and N,N
- Add 300 g of diethyl-1-naphthylamine and 360 g of toluene, and add 220 g of POCl3 to 8
Added in portions. Thereafter, the temperature was raised to 100° C. and kept warm for 50 minutes.

The reaction product was discharged into 4.2 liters of water at 50° C., the toluene was distilled by steam, and after cooling, it was filtered to obtain a resinous dye. Add this dye to 2 liters of hot water + HC
The mixture was stirred vigorously with 70 g of 70 g at 90° C. for 20 minutes, cooled, and filtered again. Mix the filtered material with 4 liters of water, add 10 liters of water, raise the temperature to 90°C, add 42 g of Victoria Blue 4R conc., mix with 1 liter of xylene, filter, and add 200 g of HCl and 650 ml of salt water to the filtrate.
was added and allowed to stand at 90°C for 4 hours, then the supernatant liquid was removed.
The remaining resinous dye was dried and exemplified compound No. 1 7
94g was obtained.

Exemplary compound No. Synthesis of 2 pure aniline 10
0 g and 206 g of pure 1-propanol were mixed, 10 g of 94% sulfuric acid was added and stirred, and the mixture was charged into an autoclave.
The temperature was raised to 205°C for an hour and kept at 205-210°C (approximately 32 atm) for 6 hours. After this, the excess 1-propanol was removed by cooling a little, neutralized with NaOH, and steam distilled to remove N.
N-di(n-propyl)aniline was obtained.

Below, exemplified compound No. Similarly to 1,
Exemplary compound no. I got 2.

The photosensitive composition of the present invention also contains a compound that generates an acid and/or a free radical upon irradiation with actinic rays.

Various known compounds can be used as compounds that generate acids and/or free radicals upon irradiation with actinic rays, including oxadiazole compounds, triazine compounds, pyrone compounds, and diazonium salts having a trihaloalkyl group. , o-naphthoquinonediazide-4-sulfonic acid chloride, etc. can be preferably used.

That is, the following general formulas [II] and [III
] Preferably, trihaloalkyl compounds or diazonium salt compounds are used.

[0023]

embedded image In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, W represents each atom of N, S, Se, P, and C, and Z
represents each atom of O, N, S, Se, and P. 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.

In the general formula [III] Ar-+N2X-,
Ar represents an aryl group, and X represents a counter ion of an inorganic compound.

Specifically, the compounds represented by the general formula [II] include compounds (1), (2), (3), (
Oxadiazole compounds having a benzofuran ring such as 7) and (9), Compound No. 1 listed in Table 1 on pages 3 to 4 of JP-A-54-74728 1~No. A compound represented by 17, or

[0026]

[Chemical formula 8]

[0027]

[Chemical Formula 9] 4-( described in JP-A-53-36223
2,4-dimethoxy-4-styryl)-6-trichloromethyl-2-pyrone compound, 2,4-bis-(trichloromethyl)-6-p-methoxy described in JP-A-48-36281 Examples include styryl-S-triazine compound, 2,4-bis-(trichloromethyl)-6-p-dimethylaminostyryl-S-triazine compound, and the like.

Furthermore, for example, Japanese Patent Publication No. 60-46700,
No. 62-44258, Japanese Patent Publication No. 1-28369, Japanese Patent Application Publication No. 58-87553, No. 60-239736, No. 6
No. 0-239473, No. 61-151644, No. 62
-24242, 62-58241, 62-17
No. 5735, No. 63-58440, No. 63-2983
Compounds described in various publications such as No. 39 can also be mentioned, and specifically, the following can be mentioned.

[0029]

[Chemical formula 10]

[0030]

[Chemical formula 11]

[0031]

[Chemical formula 12]

On the other hand, as the diazonium salt compound, a diazonium salt that generates a strong Lewis acid upon exposure to light is preferred, and as the counter ion portion, a counter ion of an inorganic compound is recommended. 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, preferably paradiazophenylamine salts.

Further, in the present invention, the following general formula [IV] can also be used as a compound that generates an acid and/or a free radical upon irradiation with actinic rays.

[0034]

[Chemical formula 13] In the formula, X is a halogen atom, -NO2, -CN, -COO
R1, -SO3R1, -SO2R2, -COR2, or a carbamoyl group, R1 represents a hydrogen atom, an alkyl group, or an aryl group, and the alkyl group and aryl group are a halogen atom, -NO2, -CN, a vinyl group, a carbamoyl group. , -COOR3, -COR3 or -SO3R3. R2 is a hydrogen atom, a halogen atom,
Represents an amino group, an alkyl group, or an aryl group, and the alkyl group or aryl group is a halogen atom, -NO2, -
CN, vinyl group, carbamoyl group, -COOR3, -C
It may be substituted with OR3 or -SO3R3. R3
represents a hydrogen atom, NH2, an alkyl group, an aryl group or an aralkyl group.

In the above general formula [IV], each halogen atom is, for example, a fluorine atom, a chlorine atom or a bromine atom, each alkyl group is, for example, a methyl group or an ethyl group, and each aryl group is, for example, a phenyl group. The base,
Examples of aralkyl groups include benzyl groups.

[0036] The compounds represented by the general formula [IV] that are preferably used in the present invention are specifically shown below, but the compounds represented by the general formula [IV] that are used in the present invention are not limited to these. It's not something you can do.

[0037]

[Chemical formula 14]

[0038]

[Chemical formula 15]

[0039]

[Chemical formula 16]

The amount of the compound that generates acid and/or free radicals upon irradiation with actinic rays in the total photosensitive layer composition is preferably 0.01 to 20% by weight, more preferably 0.01 to 20% by weight.
．． 1 to 20% by weight, particularly preferably 0.2 to 10% by weight
It is.

In the photosensitive composition of the present invention, various known photosensitive substances can be used, but o
-Naphthoquinonediazide compounds are 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 phenols and aldehydes or ketones 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 dihydric 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, and furfural. Preferred among these are formaldehyde and benzaldehyde. Further, examples of the ketone include acetone, methyl ethyl ketone, and the like.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, p-cresol/formaldehyde resin, m-cresol/formaldehyde resin, m-,p-mixed cresol/formaldehyde resin, resorcinol/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 with respect to one OH group) is:
15-80% is preferable, more preferably 20-60%
It is.

Further, as the o-naphthoquinone diazide 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-naphthoquinonediazide sulfonic acid ester and 1,2-naphthoquinonediazide sulfonic acid amide; Systems” (“Light-Se
nsitive Systems”) No. 339-352
Page (1965), John Wiley and Sons (
John Wiley & Sons (New York)
and W.S.D. Forest (W.S.D.
e Forest) “Photoresist” (“Photoresist”)
1,2-naphthoquinonediazide-5, described in ``Oresist'', Volume 50, (1975), McGraw-Hill Co., New York.
-sulfonic acid cyclohexyl ester, 1-(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-
naphthoquinonediazide-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-naphthoquinonediazide-5-sulfone 2 moles of acid chloride and 4,4'-
Condensate of 1 mole of diaminobenzophenone, 2 moles of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 4
, 1 mol of 4'-dihydroxy-1,1'-diphenylsulfone condensate, 1,2-naphthoquinonediazide-5-
Examples include 1,2-quinonediazide compounds such as a condensate of 1 mole of sulfonic acid chloride and 1 mole of purprogalin, and 1,2-naphthoquinonediazide-5-(N-dihydroabiethyl)-sulfonamide. Also, Special Publication No. 37-1953, No. 37-3627, No. 37-13
No. 109, No. 40-26126, No. 40-3801, No. 45-5604, No. 45-27345, No. 51
-13013, JP-A No. 48-96575, JP-A No. 48-
63802 and 48-63803 can also be mentioned.

Further, o-naphthoquinonediazide compounds used in the present invention include, 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-naphthoquinonediazide-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-naphthoquinone diazide
4-sulfonic acid-2,3,4',4'-tetrahydroxybenzophenone ester, 2 moles of 1,2-naphthoquinonediazide-4-sulfonic acid chloride and 1 mol of 4,4'-dihydroxy-1,1'-diphenylsulfone Examples include 1,2-naphthoquinone-2-diazide-4-sulfonic acid ester compounds of polyhydroxy compounds such as a condensate of 1 mole of 1,2-naphthoquinonediazide-4-sulfonic acid chloride and 1 mole of purpurogalin. It will be done.

Furthermore, o-naphthoquinonediazide sulfonic acid ester compounds of polyurethane resins as described below may also be used.

[0049]

[Chemical formula 17]

In the present invention, an ester compound of a vinyl polymer having a phenolic hydroxyl group and o-naphthoquinonediazide sulfonic acid can also be used as the o-naphthoquinonediazide compound. The vinyl polymer having a phenolic hydroxyl group that forms such an ester compound is a polymer having a unit having a phenolic hydroxyl group in its molecular structure, and preferably a vinyl polymer having a phenolic hydroxyl group that is used as the alkali-soluble resin described below. Polymers similar to those of vinyl polymers having structural units in their molecular structure can be used.

As the o-naphthoquinone diazide compound used in the present invention, each of the above compounds may be used alone, or two or more thereof may be used in combination. The proportion of the o-naphthoquinone diazide compound used in the present invention in the photosensitive composition is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight.

[0052] In the photosensitive composition of the present invention, an alkali-soluble resin is usually used, and various resins known in the art can be used as such resins, but in particular, novolac resins and phenolic hydroxyl groups are used. A vinyl polymer having a structural unit having this in its molecular structure is preferred.

[0053] Examples of the 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, o-cresol, m-cresol, , p-cresol, 3,5-xylenol, 2,
Examples include 4-xylenol, 2,5-xylenol, carvacrol, thymol, catechol, resorcinol, hydroquinone, pyrogallol, phloroglucin, and the like. The above-mentioned phenolic compounds can be used alone or in combination with formaldehyde to obtain a resin. Among these, preferred novolak resins are phenol,
It is a resin obtained by copolycondensing formaldehyde with at least one selected from m-cresol (or o-cresol) and p-cresol, such as phenol formaldehyde resin, m-cresol formaldehyde resin, o-cresol. Cresol/formaldehyde resin, phenol/p-cresol/formaldehyde copolymer resin, m-cresol/p-cresol/formaldehyde copolycondensate resin, o-cresol/p-cresol/formaldehyde copolycondensate resin, phenol/p-cresol/formaldehyde copolycondensate resin,
Examples include m-cresol/p-cresol/formaldehyde copolycondensate resin and phenol/o-cresol/p-cresol/formaldehyde copolycondensate resin. Furthermore, among the above novolak resins, phenol m-
Cresol/p-cresol/formaldehyde resins are preferred.

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

The molecular weight of the novolak resin (polystyrene standard) is such that the weight average molecular weight Mw is 2.0×10
3 to 2.0 x 104, number average molecular weight Mn is 7.0 x 1
It is preferable that the value is within the range of 02 to 5.0×103, and more preferably, Mw is 3.0×103 to 6.0.
×103, Mn is a value within the range of 7.7×102 to 1.2×103. The molecular weight of the novolac resin in the present invention is measured by GPC (gel permeation chromatography).

[0056] Furthermore, the vinyl polymer having a structural unit having a phenolic hydroxyl group in its molecular structure, which is preferably used in the present invention, is a polymer produced by polymerization by cleavage of a carbon-carbon double bond. Yes The following general formulas [V] to [X
] A polymer containing at least one structural unit is preferably used.

[0057]

[Chemical formula 18]

In the formula, R1 and R2 each represent a hydrogen atom, an alkyl group, or a carboxyl group, preferably a hydrogen atom. R3 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. R4 is a hydrogen atom,
It represents an alkyl group, an aryl group, or an aralkyl group, and is preferably a hydrogen atom. A represents an alkylene group that may have a substituent that connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer of 0 to 10, and B represents a phenylene group that 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 [VI] is preferred.

The vinyl polymer preferably has a copolymer-type structure, and in such a copolymer, the structural units represented by each of the general formulas [V] to [X] are Examples of monomer units that can be used in combination with at least one type include ethylenically unsaturated olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene, such as 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 - of α-methylene aliphatic monocarboxylic acids such as butyl, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, and ethyl ethacrylate. Esters, such as nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide, such as acrylanilide, p-
Anilides such as chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, etc., vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, e.g. methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, Vinyl ethers such as β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonyl Ethylene derivatives such as ethylene, 1-methyl-1-nitroethylene, such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidene, N
- Vinyl monomers such as N-vinyl compounds such as vinylpyrrolidone. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above monomers, general formulas [V] to [X
] Preferably, (meth)acrylic acids, esters of aliphatic monocarboxylic acids, and nitriles exhibit excellent overall performance. More preferred are methacrylic acid, methyl methacrylate, acrylonitrile, ethyl acrylate, and the like.

These monomers may be bound in the vinyl polymer either in a block or random manner.

In the vinyl polymer, the general formula [
The content of the structural units represented by each of [V] to [X] is preferably 5 to 70 mol%, particularly 10 to 40 mol%.
is preferred.

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

Typical examples of vinyl polymers used in the present invention are listed below. In addition, in the compounds exemplified below, Mw is weight average molecular weight, Mn is number average molecular weight,
s, k, l, o, m and n each represent mol% of the structural unit.

[0065]

[Chemical formula 19]

[0066]

[C20]

[0067]

[C21]

[0068]

[C22]

[0069]

[C23]

The proportion of the alkali-soluble resin in the photosensitive composition of the present invention is preferably 50 to 95% by weight, more preferably 60 to 90% by weight.

The photosensitive composition of the present invention may further contain an organic acid and an acid anhydride, if necessary.

[0072] As the organic acid used in the present invention, all known various organic acids can be used, but organic acids with a pKa value of 2 or more are preferred, and more preferably those with a pKa value of 3.
0 to 9.0, particularly preferably 3.5 to 8.0. However, the pKa value used in the present invention is a value at 25°C.

Examples of such organic acids include, for example, Chemical Handbook Basic Edition II (Maruzen Co., Ltd., 1966, No. 1054-1).
Among the organic acids described on page 058), all compounds that can exhibit the above pKa value can be mentioned. 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, and p-toluic acid.
-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, 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, methyl Malonic 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. 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 suitably 0.05 to 10% by weight, 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 preferred, such as phthalic anhydride, tetrahydrophthalic anhydride, etc. , hexahydrophthalic anhydride, 3,6-endoxy-Δ4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, glutaric anhydride, maleic anhydride, chloromaleic anhydride, α-
Examples include phenylmaleic anhydride, succinic anhydride, pyromellitic acid, and the like. These acid anhydrides contain 0.0% in the photosensitive layer.
It is preferably contained in an amount of 0.05 to 10% by weight, particularly 0.1 to 5% by weight.

The photosensitive composition of the present invention may further contain a compound having at least one of the following structural units [A] and [B] in its molecular structure.

[0076]

[C24]

The compound having at least one of the above structural units [A] and [B] used in the present invention may be any compound having one or both of the above structural units [A] and [B]. However, in particular, n is 2 to 5.
A compound in which n is an integer within the range of 000 and a boiling point of 240°C or higher is preferable, and more preferably n is 2 to 50.
The compound is an integer within the range of 0 and has a boiling point of 280° C. or higher, and the most preferred is a compound where n is within the range of 3 to 100.

[0078] Examples of such compounds include:

0
079]

[C25]

[0080]

[C26] etc.

Specifically, the following are preferred. 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 Sorbit, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, polyethylene glycol distearate, polyoxyethylene nonylphenyl ether formaldehyde condensate, oxyethylene oxypropylene block copolymer, polyethylene glycol, tetraethylene glycol, etc. It is.

The proportion of the compound having at least one of the structural units [A] and [B] in the photosensitive composition is preferably 0.1 to 20% by weight, more preferably 0.1 to 20% by weight based on the total composition. .2 to 10% by weight.

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

The photosensitive composition of the present invention can be used, for example, in Japanese Patent Application No. 6
3-249394 specification, page 11, lines 4 to 15 from the bottom
It may contain an oil sensitizing agent described in the fifth line from the bottom of the page.

In addition to the above-mentioned materials, the photosensitive composition of the present invention may further contain sensitizers, plasticizers, surfactants, etc., if necessary.

The photosensitive composition of the present invention can be prepared by dissolving each of the above-mentioned components in a solvent, coating the solution on the surface of a suitable support and drying it.
By forming the photosensitive layer, a photosensitive material such as a photosensitive lithographic printing plate can be obtained.

Solvents that can be used to dissolve each component of the photosensitive composition of the present invention include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate; methyl carbitol, ethyl carbitol; , diethylene glycol ethers and/or esters such as dimethyl carbitol, diethyl carbitol, and methyl carbitol acetate; dimethyl formamide, 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.

[0088] The coating method used for coating the surface of the support with the photosensitive composition of the present invention includes conventionally known methods, such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, and blade coating. Coating, curtain coating, etc. are possible. At this time, the coating amount varies depending on the application, but is preferably 0.5 to 5.0 g/m2 in terms of solid content.

Supports on which the photosensitive layer using the photosensitive composition of the present invention is provided include metal plates such as aluminum, zinc, steel, and copper, as well as metal plates plated with chromium, zinc, copper, nickel, aluminum, iron, etc. Examples include vapor-deposited metal plates, paper, plastic films, glass plates, paper coated with resin, paper covered with metal foil such as aluminum, and hydrophilic plastic films. Among these, aluminum plates are preferred. As a support for a photosensitive lithographic printing plate using the photosensitive composition of the present invention, it is preferable to use an aluminum plate that has been subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. preferable.

[0090] Known methods can be applied to these treatments.

Examples of the graining treatment include a mechanical method and an electrolytic etching method. Examples of the mechanical method include a ball polishing method, a brush polishing method, a polishing method using liquid honing, and a buffing method. 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.

[0092] Electrolytic etching can be performed using phosphoric acid, sulfuric acid, hydrochloric acid,
It is carried out in a bath containing one or more inorganic acids such as 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.

[0093] In the anodizing process, one or two types of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc. are used as the electrolyte.
Electrolysis is carried out using a solution containing at least one species, with an aluminum plate used as an anode. The amount of anodic oxide film formed is 1 to 5
0mg/dm2 is suitable, preferably 10-40m
g/dm2. The amount of anodized film can be determined by, for example, applying an aluminum plate to a phosphoric acid chromic acid solution (85% phosphoric acid solution: 35%
chromium (VI) oxide (prepared by dissolving 20 g in 1 liter of water) to dissolve the oxide film, and measure the change in weight of the plate before and after the film is dissolved.

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition, the aluminum 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.

A photosensitive lithographic printing plate to which the photosensitive composition of the present invention is applied can be developed by a conventional method. For example, the transparent positive film is exposed to light from a light source such as an ultra-high pressure mercury lamp, metal halide lamp, xenon lamp, or 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 alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, and tribasic sodium phosphate. Examples include aqueous solutions of. The concentration of the alkali metal salt is preferably 0.1 to 10% by weight. Furthermore, an anionic surfactant, an amphoteric surfactant, and an organic solvent such as alcohol can be added to the developer as required.

[0097]

[Examples] The present invention will be explained in detail below using Examples, but the present invention is not limited to these Examples unless the gist of the invention is exceeded.

Example 1 [Preparation of aluminum plate] Thickness 0
．． 24mm aluminum plate (material 1050, tempered H1
6) at 60°C in a 5% by weight aqueous sodium hydroxide solution.
After degreasing for 1 minute, the temperature was 25°C and the current density was 60A/
Electrolytic etching treatment was performed under the conditions of dm2 and treatment time of 30 seconds. 6 in a 5% by weight aqueous sodium hydroxide solution.
After desmutting at 0°C for 10 seconds, it was desmutted in a 20% by weight sulfuric acid solution at a temperature of 20°C and a current density of 3A/dm2.
Anodization treatment was performed under conditions of a treatment time of 1 minute. Furthermore,
A hot water sealing treatment was performed for 20 seconds with hot water at 80° C. to produce an aluminum plate as a support for a lithographic printing plate.

[Coating of photosensitive composition coating liquid] A photosensitive composition coating liquid of the following composition was applied to the aluminum plate prepared as described above using a rotary coater, dried at 90°C for 4 minutes, and a positive coating was applied. A photosensitive lithographic printing plate (sample No. 1) was prepared.

[0100] The thickness of the dry coating film of this sample was 2.2 g/
It was m2.

[Photosensitive composition coating liquid composition] (1) Novolac resin (1)
6.7g (2) o-naphthoquinonediazide compound (QD-1) 1.8g

[0102]

embedded image (4) Compound of the present invention Exemplary compound No. 1
0.07g (5) Methyl cellosolve
100ml

Further, Sample No. 1 was used except that (4) the compound of the present invention in the photosensitive composition coating solution was changed as shown in Table 1. Photosensitive lithographic printing plate sample No. 1 was prepared in the same manner as in the preparation of sample No. 2 to 6 were produced respectively.

[0104] Obtained sample No. For each of Samples Nos. 1 to 6, the exposure visibility was evaluated using the following method.

Further, (1) and (2) in the above photosensitive composition are shown below. (1) Novolak resin (1);
A copolycondensation resin of phenol, m-cresol, p-cresol, and formaldehyde (the molar ratio of phenol, m-cresol, and p-cresol is 2.0:4.
8:3.2, Mw=6,000, Mw/Mn=5.0)

[0106]

[C28]

<Evaluation of exposure visible image quality> Obtained photosensitive lithographic printing plate sample No. A step tablet for sensitivity measurement (No. 2 manufactured by Eastman Kodak Co., 21 gray scale with a density difference of 0.15 each) was attached to each of Nos. 1 to 6, and a 2 kW metal halide lamp (idle fin manufactured by Iwasaki Electric Co., Ltd.) was attached. 2000) was used as a light source and exposed from a distance of 90 cm. The exposure time of these samples was changed to SDR-1 (
When developing for 20 seconds at 27°C with a developer solution (manufactured by Konica Co., Ltd.) diluted 6 times with water, the time required for the steps 1.0 and 3.0 of the above step tablet to be completely cleared is 2. It was marked as a point.

The visibility of exposed visible images of these samples was visually evaluated under yellow light. Also, a densitometer (Sakura Densitometer PDA-65 (Konica)
(manufactured by Co., Ltd.)) to measure the density of exposed and unexposed areas.
The absolute value ΔD of the density difference between the exposed area and the unexposed area was determined. It shows that the larger ΔD is, the better the exposure visible image quality is.

Table 2 shows the results of the above evaluation. The results shown in Table 2 show that the photosensitive composition of the present invention provides a photosensitive lithographic printing plate having better exposed visible image properties than conventional compositions.

[0110]

[Table 1]

[0111]

[C29]

[0112]

[Table 2] * Exposure visible image property (visual observation) A state where the exposure visible image property is very good (a state where exposed areas and unexposed areas can be distinguished very clearly) is ◎, and a state where there is no exposure visible image property at all ( The state in which exposed areas and unexposed areas could not be distinguished at all) was classified into 5 grades and evaluated as XX. In other words, good exposure visibility←
◎, ○, △, ×, ××→ Poor exposure visibility image quality

[0113]
Example-2 In Example-1, the compound (3) in the photosensitive composition coating liquid composition was

[0114]

[Image Omitted] Photosensitive lithographic printing plate sample No. 7~No. 12, and the compound (3)

0
115]

[Image Omitted] Photosensitive lithographic printing plate sample No. 13~No. Photosensitive lithographic printing plate sample No. 18 was prepared and the exposure visible image quality was evaluated in the same manner as in Example-1. 7 to 10 and No. The effects of the present invention were obtained for Nos. 13 to 16.

Example-3 Photosensitive lithographic printing plate sample No. prepared in Example-1. 1~
No. Half of each sample No. 6 was covered with black paper that does not transmit any light, and a halftone film with a halftone ratio of 90% was attached to the remaining half, and exposed in the same manner as in Example-1.

For each of these samples, the visibility of the boundary between the exposed visible image covered by the black paper and the halftone film in close contact was visually evaluated under a yellow light. The results are shown in Table 3. From Table 3, the effects of the present invention are clear.

[0118]

[Table 3] * Ease of seeing the boundary between the unexposed area and the exposed area. ◎ indicates that the boundary is very clearly visible, and XX indicates that the boundary is not visible at all.
The evaluation was divided into five stages. In other words, the border is clearly visible←◎,○,△,×,××→The border is not visible at all

[0119]

As described in detail above, the present invention makes it possible to provide a photosensitive composition suitable for a photosensitive lithographic printing plate that has excellent exposure visible image properties even when exposed to low-intensity light.

Claims (1)

[Claims] 1. A photosensitive composition comprising a dye having a structure represented by the following general formula [I]. [Formula 1] [Here, R1 and R2 represent a hydrogen atom or an alkyl group having 2 or more carbon atoms, and R3 to R6 are R1, R2
When at least one of 2 is a hydrogen atom, it represents an alkyl group, alkoxy group, aryl group, or heterocyclic group having 3 or more carbon atoms, which may be the same or different, and both R1 and R2 are carbon atoms. In the case of an alkyl group having two or more carbon atoms, each represents an alkyl group, an alkoxy group, an aryl group, or a heterocyclic group having two or more carbon atoms, which may be the same or different, and X- represents an inorganic acid or an organic acid. represents the anion of ]