JPH11216962A - Method for making lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for making a lithographic printing plate having a photosensitive layer made of a positive type photosensitive composition for an infrared laser for a direct plate-making. SOLUTION: In the method for making a lithographic printing plate having a photosensitive layer obtained by coating a hydrophilic support with a positive type photosensitive composition for an infrared laser comprising the steps of exposing it with the laser, and developing it with an alkali developing liquid containing at least one type of non-cyclic sugar and a base; the composition preferably contains at least one type of an alkali aqueous solution soluble polymer compound having at least one of a phenolic hydroxyl group, a sulfoneamide group, and an active imide group, a solubility of the polymer compound in the alkali aqueous solution is lowered by making it compatible with alkali aqueous solution soluble polymer compound, and a compound for reducing a solubility lowering action by heating and a compound for heating by absorbing alight are contained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making method for an image recording material which can be used as an offset printing master, and more particularly to a positive photosensitive composition for an infrared laser for so-called direct plate making which can make a plate directly from a digital signal of a computer or the like. The present invention relates to a method for producing a lithographic printing plate provided with a photosensitive layer made of a material.

[0002]

2. Description of the Related Art In recent years, a positive photosensitive lithographic printing plate precursor (hereinafter, sometimes referred to as an "infrared photosensitive lithographic printing plate precursor") which can be directly drawn by an infrared laser has been known. Generally, alkaline aqueous solutions of silicates such as sodium silicate and potassium silicate are used. However, when this alkaline aqueous solution of silicate is used as a developing solution, there are the following problems. That is, the difference in solubility between the infrared laser-irradiated part and the unirradiated part is very small as compared with the difference between the exposed part and the unexposed part of the conventional photosensitive lithographic printing plate precursor, and the suitable range for development is narrow. That is the problem. In addition, such an infrared-sensitive lithographic printing plate precursor has a problem that the ink-adhering property is significantly poor, and a good printed matter is often not obtained even after printing several tens of sheets from the start of printing. Since these problems are particularly remarkable in an infrared-sensitive lithographic printing plate precursor using aluminum as a support, the thermal energy of the irradiated infrared radiation is radiated through an aluminum support having good thermal conductivity, so that sufficient decomposition is required. It is presumed that no reaction occurred.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a method of making a lithographic printing plate using a development processing method suitable for an infrared-sensitive lithographic printing plate precursor that can be directly drawn by an infrared laser.

[0004]

Means for solving the above problems are as follows. That is, <1> a step of exposing a lithographic printing plate precursor having a photosensitive layer obtained by applying a positive photosensitive composition for an infrared laser on a hydrophilic support with an infrared laser, and at least one type of non-reducing sugar; And a step of developing with an alkaline developing solution containing at least one base. <2> The method of making a lithographic printing plate according to <1>, wherein the positive photosensitive composition for an infrared laser contains the following (A) to (C). (A) at least one kind of an aqueous alkaline solution-soluble polymer compound having at least one of the following functional groups (a-1) to (a-3): (A-1) a phenolic hydroxyl group, (a-2) a sulfonamide group, and (a-3) an active imide group. And (B) a compound which, when compatible with the aqueous alkali-soluble polymer compound, reduces the solubility of the polymer compound in an aqueous alkaline solution and reduces the solubility lowering effect by heating. (C) a compound that absorbs light and generates heat. <3> (B) a compound which, when miscible with the alkali aqueous solution-soluble polymer compound, reduces the solubility of the polymer compound in the alkali aqueous solution and reduces the solubility lowering effect by heating; (2) The method of making a lithographic printing plate as described in (2) above, wherein the lithographic printing plate contains one compound having both properties instead of a compound having a function of absorbing light to generate heat.

In the present invention, when the positive photosensitive composition for an infrared laser contains the above (A) to (C), (A) an alkali aqueous solution-soluble polymer compound includes:
(B) a molecule having a group that interacts with the alkali aqueous solution-soluble polymer compound in the molecule to reduce the solubility of the polymer compound in the alkali aqueous solution by being compatible with the polymer compound, and (C) a compound that absorbs light and generates heat,
By combining (B) with the alkali aqueous solution-soluble polymer compound, the compound which reduces the solubility of the polymer compound in the alkali aqueous solution by compatibilization with the alkali aqueous solution and reduces the solubility lowering action by heating, At the time of coating film formation, (A) an alkaline aqueous solution-soluble polymer compound is uniformly dissolved to form a uniform photosensitive layer (hereinafter sometimes referred to as a “coating layer”), and the aqueous alkaline solution of the component (A) However, by subjecting this photosensitive layer to an exposure step by irradiating an infrared laser, the compound that absorbs (C) light and generates heat in the exposed portion generates heat,
The component (A) and the component (B) are separated from each other to reduce the dissolution inhibiting ability due to the interaction. In the developing step, exposure is carried out with an alkali developing solution containing at least one non-reducing sugar and at least one base. The portion is easily removed, and good image formation, that is, plate making is performed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The method for producing a lithographic printing plate according to the present invention comprises a step of exposing a lithographic printing plate precursor to an infrared laser and a step of developing the plate with an alkali developing solution.

((Lithographic printing original plate)) The lithographic printing original plate has a photosensitive layer formed by coating a positive photosensitive composition for infrared laser on a hydrophilic support, and further, if necessary. , And other layers.

(Photosensitive Layer) The photosensitive layer is formed by coating a positive photosensitive composition for infrared laser on the support. The positive photosensitive composition for an infrared laser is preferably (A) an alkali aqueous solution-soluble polymer compound,
(B) a compound in which the solubility of the polymer compound in an aqueous alkali solution is reduced by being compatible with the alkali aqueous solution-soluble polymer compound, and the solubility lowering action is reduced by heating; It contains a compound that absorbs and generates heat. In addition to the above-mentioned components, if necessary, other components such as a cyclic acid anhydride and the like are further contained. Further, in the present invention, the positive photosensitive composition for an infrared laser reduces the solubility of the polymer compound in an alkali aqueous solution by being compatible with the (B) alkali aqueous solution-soluble polymer compound, One compound having both properties (hereinafter, referred to as “(B + C) component”) is used in place of the compound whose solubility lowering effect is reduced by heating and the compound (C) which absorbs light and generates heat. ) Can be contained.

-(A) Soluble high molecular weight compound in aqueous alkali solution- The (A) high molecular weight compound soluble in aqueous alkali solution used in the present invention has the following functional group (a-1) phenolic hydroxyl group, (a-2) sulfone It is a polymer compound having at least one of an amide group and (a-3) an active imide group in a molecule, and preferably is a resin (a-1) an alkaline aqueous solution-soluble resin having a phenolic hydroxyl group (hereinafter referred to as “phenolic resin”). And a copolymer containing at least one of the functional groups (a-1) to (a-3) as a copolymer component in an amount of 10 mol% or more (hereinafter referred to as a “specific copolymer”). ) May be used.

--- (a-1) Alkaline aqueous solution-soluble polymer compound having phenolic hydroxyl group-- Examples of the polymer compound include phenol formaldehyde resin, m-cresol formaldehyde resin,
Novolak resins such as p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p-, or m- / p-mixture) mixed formaldehyde resin, and pyrogallol acetone resin. Can be mentioned.

The resin having a phenolic hydroxyl group preferably has a weight average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 10,000. Further, as described in U.S. Pat. No. 4,123,279, a condensate of phenol having a C3-8 alkyl group as a substituent and formaldehyde, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin. May be used in combination. One or more of these resins having a phenolic hydroxyl group may be used in combination.

-(A-2) Alkaline aqueous solution-soluble polymer compound having a sulfonamide group--The main monomer constituting the polymer compound (a-
2) The monomer having a sulfonamide group includes a sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom in one molecule and a low-molecular compound having at least one polymerizable unsaturated bond. Monomer. Among them, acryloyl group, allyl group,
Alternatively, a low-molecular compound having a vinyloxy group and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group is preferable. Examples of such compounds include compounds represented by the following general formulas (I) to (V).

[0013]

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Where X¹And X^TwoAre -O- or
Is -NR⁷Indicates-. R¹And R^FourIs the hydrogen source
Child or -CH_ThreeRepresents R^Two, R^Five, R⁹, R¹²,as well as
R¹⁶Has 1 to 1 carbon atoms which may have a substituent.
12 alkylene groups, cycloalkylene groups, arylene
Or an aralkylene group. R^Three, R⁷, And R ¹³
Is a hydrogen atom, a carbon which may have a substituent
Alkyl groups, cycloalkyl groups, aryls of formulas 1 to 12
And an aralkyl group. Also, R⁶And R¹⁷Is
Each of C 1 to C 12 which may have a substituent
Alkyl, cycloalkyl, aryl, or aralkyl
Represents a kill group. R⁸, R^Ten, And R¹⁴Is a hydrogen atom or
-CH_ThreeRepresents R¹¹And R^FifteenIs a single bond or
C1-C12 alkylene optionally having substituent (s)
Group, cycloalkylene group, arylene group, or aralkyl
Represents a len group. Y¹And Y^TwoIs a single bond or-
Represents CO-.

Specifically, m-aminosulfonylphenyl methacrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be suitably used.

-(A-3) Alkaline aqueous solution-soluble polymer compound having an active imide group-- The polymer compound has an active imide group represented by the following formula in the molecule. The monomer having an active imide group (a-3), which is a main monomer constituting the compound, has one or more active imide groups represented by the following formula and one or more polymerizable unsaturated bonds in one molecule. Monomers composed of low molecular weight compounds are exemplified.

[0017]

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As such a compound, specifically,
N- (p-toluenesulfonyl) methacrylamide, N
-(P-Toluenesulfonyl) acrylamide and the like can be suitably used.

--Specific copolymer-- As the (A) aqueous alkaline solution-soluble polymer compound according to the present invention, the monomer having a functional group of (a-1) to (a-3) is used as a main structural unit. (A-1) a resin having a phenolic hydroxyl group, and a polymer (a-1) to (a-
A copolymer containing at least one of 3) as a copolymer component in an amount of 10 mol% or more can be used. Hereinafter, this copolymer will be described.

The (a-1) high molecular compound having a phenolic hydroxyl group includes, for example, phenol formaldehyde resin and m-cresol formaldehyde resin. Another monomer having a lipophilic hydroxyl group can also be copolymerized, and the monomer corresponding to (a-1) as the copolymer component includes acrylamide, methacrylamide, acrylate, methacrylic, each having a phenolic hydroxyl group. It is a monomer composed of an acid ester or hydroxystyrene. As such a compound, specifically, N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide, o-hydroxyphenyl acrylate, m-
Preferably used are hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, o-hydroxyphenyl methacrylate, m-hydroxyphenyl methacrylate, p-hydroxyphenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene and the like. it can.

Similarly, the above-mentioned monomer (a-2) having a sulfonamide group or (a-3) a monomer having an active imide group can be used as a copolymer component.

The alkaline aqueous solution-soluble copolymer which can be used in the present invention preferably contains at least one of the above (a-1) to (a-3) as a copolymer component in an amount of 10 mol% or more. Those containing at least mol% are more preferred. When the amount of the copolymer component is less than 10 mol%, the interaction with the resin having a phenolic hydroxyl group becomes insufficient, and the effect of improving the development latitude, which is an advantage of using the copolymer component, becomes insufficient. In addition, the copolymer may contain other copolymer components other than the above (a-1) to (a-3).

As the other copolymer components, for example, the following monomers (1) to (12) can be used. (1) For example, 2-hydroxyethyl acrylate, 2
Acrylates and methacrylates having an aliphatic hydroxyl group such as hydroxyethyl methacrylate; (2) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl Alkyl acrylates such as acrylates; (3) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl Alkyl methacrylates such as methacrylate. (4) acrylamide, methacrylamide, N-methylolacrylamide, N-ethylacrylamide, N-
Hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-
Acrylamide or methacrylamide such as phenylacrylamide, N-nitrophenylacrylamide, and N-ethyl-N-phenylacrylamide. (5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.

(6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate. (7) Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene. (8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone. (9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene. (10) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like. (11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide. (12) acrylic acid, methacrylic acid, maleic anhydride,
Unsaturated carboxylic acids such as itaconic acid;

--- (A) Molecular Weight of Alkaline Aqueous Solution-Soluble Polymer Compound-- In the present invention, the (A) alkali-water-soluble polymer compound has a weight average molecular weight irrespective of a homopolymer or a copolymer. Those having a number average molecular weight of 2,000 or more and 500 or more are preferred. More preferably, the weight average molecular weight is 5
000 to 300,000, number average molecular weight of 800 to 250
000 and a degree of dispersion (weight average molecular weight / number average molecular weight) of 1.1 to 10.

When the resin (a-1) having a phenolic hydroxyl group constitutes a copolymer with the above-mentioned specific copolymer component, the compounding weight ratio of these components is 50:50 to 5:95.
Preferably in the range of 40:60 to 10:90.
Is more preferably within the range.

These (A) alkaline aqueous solution-soluble polymer compounds may be used alone or in combination of two or more kinds. The solid content of the photosensitive layer is 30 to 99% by weight, preferably 40 to 95% by weight. Particularly preferably 5
It is used in an amount of 0 to 90% by weight. If the amount of the alkali aqueous solution-soluble polymer compound is less than 30% by weight, the durability of the photosensitive layer deteriorates, and if it exceeds 99% by weight, it is not preferable in terms of both sensitivity and durability.

-(B) a compound which reduces the solubility of the polymer compound in an aqueous alkali solution by being compatible with the alkali aqueous solution-soluble polymer compound and reduces the solubility lowering effect by heating. The component (B) has good compatibility with the (A) aqueous alkali compound soluble in an aqueous alkali solution, can form a uniform mixed solution, and has a functional group such as a hydrogen bonding group present in the molecule. By the action, in the photosensitive layer formed by the coating solution uniformly mixed with the component (A), the solubility of the component (A) in the aqueous alkali solution is suppressed by the interaction with the polymer compound as the component (A). A compound having the function of performing In addition, this compound loses its solubility lowering effect by heating. However, when the component (B) itself is a compound that decomposes by heating, as described above, sufficient energy for decomposition can be obtained by laser output or irradiation. If it is not given by conditions such as time, the effect of suppressing the solubility is insufficiently reduced and the sensitivity may be lowered. Therefore, the thermal decomposition temperature of the component (B) is preferably 150 ° C. or higher. .

Suitable components (B) for use in the present invention include compounds that interact with component (A), such as sulfone compounds, onium salts, amide compounds, and quinonediazides. These are thermally decomposable, and when they are not decomposed, they substantially reduce the solubility of the alkaline water-soluble polymer compound. Therefore, the use of these substances in combination is preferable in that the dissolution inhibiting property of the image area in the developer can be improved.

Examples of the onium salt include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts and the like. More specifically, S.M. I. Sch
Lessinger, Photogr. Sci. En
g. , 18, 387 (1974); S. Bal e
tal, Polymer, 21, 423 (1980)
Diazonium salts described in U.S. Pat. No. 4,069,05
Nos. 5,069,056 and Re27,992, and the ammonium salts described in JP-A-4-365049, respectively. C. Necker et
al, Macromolecules, 17, 2468.
(1984), C.I. S. Wen et al, Teh,
Proc. Conf. Rad, Curing ASI
A, p478 Tokyo, Oct (1988); U.S. Pat. Nos. 4,069,055 and 4,069,056; V. Criv
ello et al, Macromolecule
s, 10 (6), 1307 (1977), Chem. &
Eng. News, Nov .; 28, p31 (198
8), EP 104,143, US Patent 33
Iodonium salts described in JP-A Nos. 9,049 and 410,201, JP-A-2-150848, and JP-A-2-296514;

J. V. Crivello et al,
Polymer J. J. 17, 73 (1985);
V. Crivello et al. J. Org. Ch
em. 43, 3055 (1978); R. Wat
t et al, J.M. Polymer Sci. , Po
lymer Chem. Ed. , 22, 1789 (19
84); V. Crivello et al, Po
lymerBull. , 14, 279 (1985),
J. V. Crivello et al, Macrom
olecules, 14 (5), 1141 (198
1). V. Crivello et al, J. Mol. P
polymer Sci. , Polymer Chem.
Ed. , 17, 2877 (1979), EP 37
Nos. 0,693, 390,214, 233,567
Nos. 297,443 and 297,442; U.S. Pat. Nos. 4,933,377; 161,811;
No. 10,201, No. 339,049, No. 4,760,
No. 013, No. 4,734,444, No. 2,833,8
No. 27, German Patent Nos. 2,904,626 and 3,60
4,580, 3,604,581, the sulfonium salt described in each specification,

J. V. Crivello et al,
Macromolecules, 10 (6), 1307
(1977); V. Crivello et a
1, J .; Polymer Sci. , Polymer
Chem. Ed. , 17, 1047 (1979); S. Wen et al, Te
h, Proc. Conf. Rad. Curing AS
IA, p. 478, Tokyo, Oct (1988).
Among them, in the present invention, diazonium salts are particularly preferred, and particularly preferred diazonium salts include those described in JP-A-5-158230.

As the counter ion of the onium salt, for example, tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5 -Dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid,
2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-
Benzenesulfonic acid, paratoluenesulfonic acid and the like can be mentioned. Of these, alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, and 2,5-dimethylbenzenesulfonic acid are preferable.

The quinonediazides include, for example,
o-quinonediazide compounds and the like. O-
A quinonediazide compound is a compound having at least one o-quinonediazide group and increasing alkali solubility by thermal decomposition. In the present invention, compounds having various structures can be used. In the present invention, the o-quinonediazide loses the ability to inhibit the dissolution of the aqueous alkali-soluble polymer compound due to thermal decomposition, and the o-quinonediazide itself is converted into an alkali-soluble substance. Help solubility.

Examples of the o-quinonediazide compound used in the present invention include those described in J. Am. "Light-Sensitive Systems" by Coser (John Wiley &
Sons. Inc. ) P. 339-352, but sulfonic acid esters or sulfonic acid amides of o-quinonediazide reacted with various aromatic polyhydroxy compounds or aromatic amino compounds are particularly preferred. Also, benzoquinone (1,2) -diazidosulfonic acid chloride or naphthoquinone- (1,2) as described in JP-B-43-28403.
Esters of diazide-5-sulfonic acid chloride with pyrogallol-acetone resin, U.S. Pat.
Benzoquinone- (1,2) -diazidesulfonic acid chloride or naphthoquinone- (1,2) -diazide- described in US Pat.
Esters of 5-sulfonic acid chloride with phenol-formaldehyde resin are also suitably used.

Further, an ester of naphthoquinone- (1,2) -diazide-4-sulfonic acid chloride with a phenol formaldehyde resin or a cresol-formaldehyde resin, naphthoquinone- (1,2) -diazide-4
Esters of sulfonic acid chloride with pyrogallol-acetone resin are likewise preferably used. Other useful o-quinonediazide compounds are reported and known in numerous patents. For example, JP-A-47-530
No. 3, JP-A-48-63802, JP-A-48-638
03, JP-A-48-96575, JP-A-49-38
No. 701, JP-A-48-13354, JP-B-41-1
1222, JP-B-45-9610, JP-B-49-1
7481, U.S. Pat. No. 2,797,213.
No. 3,454,400, No. 3,544,32
No. 3, No. 3,573,917, No. 3,674, 4
No. 95, 3,785, 825 and British Patent Nos. 1, 2
No. 27,602, No. 1,251,345, No. 1,
267,005, 1,329,888 and 1,330,932, and German Patent No. 854,890.

The content of the o-quinonediazide compound in the photosensitive layer is usually about 1 to 50% by weight, preferably 5 to 30% by weight, more preferably 10 to 30% by weight based on the total solid content in the photosensitive layer. % By weight is particularly preferred.
These may be used alone or in combination of two or more. The component (B) should be appropriately selected in consideration of the interaction with the component (A) as described above. Specifically, for example, a novolak resin alone as the component (A) is used. When used, a cyanine dye A or the like exemplified in Examples described later is suitably used.

It is preferable that the mixing ratio of the component (A) and the component (B) is usually in the range of 99/1 to 75/25. When the component (B) is less than 99/1,
Interaction with the component (A) becomes insufficient, so that the solubility of the aqueous alkali solution cannot be inhibited, and it is difficult to form a good image. When the content of the component (B) is larger than 75/25, the interaction is excessively large, and the sensitivity is remarkably lowered.

-(C) Compound that absorbs light and generates heat- In the present invention, (C) the compound that generates heat by absorbing light has a light absorption region in the infrared region of 700 nm or more, and preferably 750 to 750 nm. In the infrared region of 1200 nm, it refers to a material exhibiting light / heat conversion capability in light of this wavelength range. Specifically, various pigments or dyes that absorb light in this wavelength region and generate heat are used. Can be used. Examples of the pigment include a commercially available pigment and a color index (C.I.
I. ) Handbook, "Latest Pigment Handbook" (edited by Japan Pigment Technology Association,
1977), “Latest Pigment Application Technology” (CMC Publishing,
1986), "Printing ink technology" (CMC Publishing, 1
984) and the like.

Examples of the pigments include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and polymer-bound pigments. Can be Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelated azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments And quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like.

These pigments may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. Examples of the surface treatment include a method of surface-coating a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (for example, a silane coupling agent, an epoxy compound, or a polyisocyanate) to the pigment surface. And so on. The above surface treatment methods are described in “Properties and Applications of Metallic Soap” (Koshobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986).
Annual).

The particle size of the pigment is preferably 0.01 to 10 μm, more preferably 0.05 to 1 μm, and 0.1 to 10 μm.
1 μm is particularly preferred. The particle size of the pigment is 0.01μ
If it is less than m, it is not preferable in terms of stability of the dispersion in the coating solution of the photosensitive layer, and if it exceeds 10 μm, it is not preferred in terms of uniformity of the photosensitive layer. As a method for dispersing the pigment, a known dispersion technique used for ink production, toner production, or the like can be used. As the disperser, an ultrasonic disperser,
Sand mills, attritors, pearl mills, super mills, ball mills, impellers, dispersers, KD mills, colloid mills, dynatrons, three-roll mills, pressure kneaders and the like can be mentioned. Details are described in "Latest Pigment Application Technology" (CMC Publishing, 1986).

Examples of the dye include commercially available dyes and literatures (eg, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, Showa 45)
Known publications described in the annual publication can be used. Specific examples include azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, and cyanine dyes. In the present invention, among these pigments or dyes, those that absorb infrared light or near-infrared light are particularly preferable because they are suitable for use in lasers that emit infrared light or near-infrared light.

As such a pigment that absorbs infrared light or near infrared light, carbon black is preferably used. Dyes that absorb infrared light or near infrared light include, for example, JP-A-58-125246 and JP-A-5-125246.
9-84356, JP-A-59-202829, JP-A-60-78787, and the like, and JP-A-58-173696 and JP-A-58-181.
690, JP-A-58-194595 and the like; JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996. JP-A-60-52940,
Examples include naphthoquinone dyes described in JP-A-60-63744, squarylium dyes described in JP-A-58-112792, and cyanine dyes described in British Patent 434,875.

As the dye, US Pat. No. 5,156,9
No. 38, a near-infrared absorption sensitizer is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645 (U.S. Pat. No. 4,327,169), a trimethinethiapyrylium salt described in JP-A-58-1810.
No. 51, No. 58-220143, No. 59-41363
Nos. 59-84248, 59-84249, 59-146063, and 59-146061; pyrylium compounds described in JP-A-59-216146; cyanine dyes described in JP-A-59-216146; U.S. Pat. No. 475, pentamethine thiopyrylium salt, JP-B 5-135
No. 14, the pyrylium compound described in No. 5-19702,
Epollight III-178, Epollight III
-130, Epollight III-125 and the like are particularly preferably used.

Another particularly preferred example of the dye is a near-infrared absorbing dye described as formulas (I) and (II) in US Pat. No. 4,756,993. . These pigments or dyes are used in an amount of 0.01 to 50% by weight, preferably 0.1 to 10% by weight, particularly preferably 3.1 to 10% by weight in the case of pigments, and in the case of dyes. Particularly preferably 0.5
To 10% by weight in the photosensitive layer. If the amount of the pigment or dye is less than 0.01% by weight, the sensitivity becomes low, and if it exceeds 50% by weight, the uniformity of the photosensitive layer is lost and the durability of the photosensitive layer is deteriorated.
These dyes or pigments may be added to the same layer as other components, or another layer may be provided and added thereto.
In the case of a separate layer, it is desirable to add it to a layer adjacent to the layer containing a substance that is thermally decomposable according to the present invention and that substantially reduces the solubility of the binder when not decomposed. The dye or pigment and the binder resin are preferably in the same layer, but may be in different layers.

Component (B + C) Examples of the compound of the component (B + C) include compounds represented by the following general formula (I).

[0048]

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In the general formula (I), R₁, R_Two, R_Three,
And R_FourEach independently has a hydrogen atom and a substituent
Alkyl groups having 1 to 12 carbon atoms, alkenyl groups,
Represents a alkoxy group, a cycloalkyl group, or an aryl group;
₁And R_Two, R_ThreeAnd R_FourCombine to form a ring structure
It may be. Where R₁, R_Two, R_Three, And R _Four
Specific examples include a hydrogen atom, a methyl group, and an ethyl group.
Group, phenyl group, dodecyl group, naphthyl group, vinyl group,
Examples include an allyl group and a cyclohexyl group. Also,
When these groups have a substituent, as the substituent,
Halogen atom, carbonyl group, nitro group, nitrile group,
Sulfonyl group, carboxyl group, carboxylic acid ester,
And sulfonic acid esters. R_Five~ R_TenIs
C 1 to C 12 each independently having a substituent.
Represents a alkyl group, wherein R_Five~ R_TenAs specific
Has a methyl group, an ethyl group, a phenyl group, a dodecyl group,
Naphthyl group, vinyl group, allyl group, cyclohexyl group, etc.
Is mentioned. In addition, when these groups have a substituent,
When the substituent is a halogen atom, carbonyl
Group, nitro group, nitrile group, sulfonyl group, carboxy
Groups, carboxylic acid esters, sulfonic acid esters, etc.
I can do it.

[0050] R _11, R _12, and R ₁₃ are each independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, wherein, R ₁₂ is R _It may combine with ₁₁ or R ₁₃ to form a ring structure, and when m> 2, a plurality of R ₁₂ may combine with each other to form a ring structure. Specific examples of R ₁₁ , R ₁₂ , and R ₁₃ include a chlorine atom, a cyclohexyl group, a cyclopentyl ring in which R ₁₂ is bonded to each other, a cyclohexyl ring, and the like. When these groups have a substituent, the substituent may be a halogen atom, a carbonyl group, a nitro group,
Examples thereof include a nitrile group, a sulfonyl group, a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester. M represents an integer of 1 to 8, and preferably 1 to 3.

R ₁₄ and R ₁₅ each independently represent a hydrogen atom, a halogen atom or a carbon atom having 1 to 8 carbon atoms which may have a substituent.
R ₁₄ may be bonded to R ₁₅ to form a ring structure, and when m> 2, a plurality of R ₁₄ may be bonded to each other to form a ring structure. . R ₁₄ and R ₁₅ are specifically a chlorine atom, a cyclohexyl group, R ₁₄
Examples thereof include a cyclopentyl ring and a cyclohexyl ring formed by bonding each other. When these groups have a substituent, examples of the substituent include a halogen atom, a carbonyl group, a nitro group, a nitrile group, a sulfonyl group, a carboxyl group, a carboxylic acid ester, and a sulfonic acid ester. M represents an integer of 1 to 8, and preferably 1 to 3.

In the general formula (I), X ⁻ represents an anion. Wherein X ^- include specific examples of the anion represented by perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, triisopropyl naphthalenesulfonic acid, 5-nitro -o-
Toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-
Dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid,
3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5
-Sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, p-toluenesulfonic acid and the like. Among these, hexafluorophosphoric acid, alkylaromatic sulfonic acids such as triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid are particularly preferable.

The compound represented by the general formula (I) is a compound generally called a cyanine dye. Specifically, the following compounds are suitably used, but the present invention is not limited to these specific examples. It is not something to be done.

[0054]

Embedded image

The compound [(B + C) component] has a property of absorbing light to generate heat (that is, the characteristic of the component (C)), and has a light absorption region in an infrared region of 700 to 1200 nm. Further, it has good compatibility with an aqueous alkali-soluble polymer compound, is a basic dye, and has a group that interacts with an aqueous alkali-soluble polymer compound such as an ammonium group and an iminium group in the molecule (that is, (( B) having the properties of the component) to interact with the polymer compound to control its solubility in aqueous alkali solution;
It can be suitably used in the present invention.

In the present invention, the component (B), the component (C)
When a compound having both properties such as the cyanine dye [component (B + C)] is used instead of the component, the amount of the compound added is 99/1 with respect to the component (A).
The range of -70/30 is preferable from the viewpoint of sensitivity, and 99/30.
The range of 1 to 75/25 is more preferable.

-Other components- The positive photosensitive composition for an infrared laser according to the present invention includes:
If necessary, various additives and the like can be added as other components. For example, a cyclic acid anhydride, a phenol, or an organic acid can be used in combination for the purpose of improving sensitivity.

As the cyclic acid anhydride, any acid anhydride having a cyclic structure such as phthalic anhydride can be used. Specifically, US Pat.
Phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride described in US Pat. No. 5,128;
Tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be preferably used. The amount of the cyclic acid anhydride to be added is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight.
When the addition amount exceeds 20% by weight, the sensitivity fluctuation due to the hydrolysis of the cyclic acid anhydride becomes too large, and when the addition amount is less than 0.5% by weight, the effect is insufficient and both are not preferred.

Examples of the 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.

The organic acids are described in JP-A-60-88.
942, JP-A-2-96755, and the like, and include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphoric esters, carboxylic acids, and the like. Acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4- Examples include dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid, and the like. The ratio of the phenols and organic acids in the positive photosensitive composition for infrared laser is 0.05 to 2%.
It is preferably 0% by weight, more preferably 0.1 to 15% by weight, particularly preferably 0.1 to 10% by weight.

The positive photosensitive composition for an infrared laser according to the present invention is disclosed in JP-A-62-251740 and JP-A-3-208514 in order to increase the stability of processing under development conditions. And non-ionic surfactants such as those described in JP-A-59-121044 and JP-A-4-13149 can be added.

Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearate, and polyoxyethylene nonyl phenyl ether.

Specific examples of the amphoteric surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl- N, N-betaine type (for example, trade name "Amogen K", manufactured by Dai-ichi Kogyo Co., Ltd.) and the like. The proportion of the nonionic surfactant and amphoteric surfactant in the positive photosensitive composition for infrared laser is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight. It is.

The positive photosensitive composition for an infrared laser according to the present invention may contain a printing-out agent for obtaining a visible image immediately after heating by exposure, and a dye or pigment as an image coloring agent. it can. Representative examples of the printing-out agent include a combination of a compound (photoacid releasing agent) that releases an acid by heating upon exposure 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, JP-A-54-74728, and JP-A-60-74-128. No. 3626, 61-1
No. 43748, No. 61-151644 and No. 63-5
The combination of the trihalomethyl compound and the salt-forming organic dye described in each publication of No. 8440 can be exemplified. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear print-out images.

As the image coloring agent, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Suitable dyes including the 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 B
OS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (above,
Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI5
2015). In addition, Japanese Unexamined Patent Publication
The dyes described in JP-293247 are particularly preferred. These dyes are based on the total solid content of the photosensitive layer.
0.01 to 10% by weight, preferably 0.1 to 3% by weight, can be added to the positive photosensitive composition for infrared laser.

Further, a plasticizer may be added to the positive photosensitive composition for an infrared laser of the present invention, if necessary, 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 Oligomers and polymers are used. Further, a long-chain fatty acid ester, a long-chain fatty acid amide, or the like may be added to improve the film strength.

-Method for Producing Photosensitive Layer- The photosensitive layer to which the plate making method of the present invention can be applied can be usually produced by dissolving the above-mentioned components in a solvent and coating the solution on a suitable support. As the solvent used herein, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, toluene and the like can be mentioned. However, the present invention is not limited to this.

These solvents are used alone or as a mixture. The concentration of the above components (total solids including additives) in the solvent is preferably 1 to 50% by weight. Coating amount (solid content) on support obtained after coating and drying
Although it depends on the application, the photosensitive lithographic printing plate precursor is generally preferably 0.5 to 5.0 g / m ² .
Various methods can be used as the method of 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 characteristics of the photosensitive layer deteriorate. In the photosensitive layer according to the invention, a surfactant for improving coating properties, for example, a fluorine-based surfactant described in JP-A-62-170950 can be added. The preferred addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight of the photosensitive layer.

(Support) 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 plates (eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, Polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which the metal is laminated or vapor-deposited, and the like.

As the support of the present invention, a polyester film or an aluminum plate is preferable, and 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 trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in aluminum alloys include silicon, iron, manganese,
Copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of foreign elements in the alloy is at most 1
0% by weight or less. Aluminum which is particularly preferred in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 to 0.6 mm, preferably 0.15 to 0.4 mm, particularly preferably 0.2 to 0.4 mm.
0.3 mm.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like is performed to remove the rolling oil on the surface. The surface roughening treatment of the surface of the aluminum plate is performed by various methods, for example, a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of chemically roughening the surface. It is performed by a method of selective dissolution. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. In addition, as the electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can be used. The aluminum plate thus roughened is subjected to an alkali etching treatment and a neutralization treatment as required, and then subjected to an anodic oxidation treatment as required to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used, and generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. Can be The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte.

The anodizing treatment conditions vary depending on the electrolyte to be used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, and the solution temperature is 5 to 70%.
° C, current density 5-60 A / dm ² , voltage 1-100 V,
An electrolysis time of 10 seconds to 5 minutes is appropriate. If the amount of the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image portion of the lithographic printing plate becomes easily scratched, and the ink adheres to the scratched portion during printing. So-called “scratch dirt” easily occurs.

After the anodic oxidation treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. U.S. Pat. No. 2,711 describes hydrophilic treatment for use in the present invention.
No. 4,066, No. 3,181,461, No. 3,28
There is an alkali metal silicate (for example, sodium silicate aqueous solution) method as disclosed in U.S. Pat. Nos. 0,734 and 3,902,734. In this method, the support is immersed in an aqueous solution of sodium silicate,
Or it is electrolytically treated. Also, potassium fluoride zirconate disclosed in JP-B-36-22063 and U.S. Pat. Nos. 3,276,868 and 4,153,461.
And the method of treating with polyvinyl phosphonic acid as disclosed in JP-A No. 4,689,272.

(Other Layers) The lithographic printing plate precursor according to the present invention has a photosensitive layer provided by coating a positive photosensitive composition for an infrared laser on a hydrophilic support. In accordance therewith, an undercoat layer can be provided as the other layer therebetween. As the component of the undercoat layer, various organic compounds are used, and for example, phosphonic acids having an amino group such as carboxymethyl cellulose, dextrin, gum arabic, and 2-aminoethyl phosphonic acid, and may have a substituent. Phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, organic phosphonic acids such as methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, alkylphosphoric acid and Organic phosphoric acid such as glycerophosphoric acid, phenylphosphinic acid which may have a substituent,
Organic phosphinic acids such as naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydrochlorides of amines having a hydroxy group such as hydrochloride of triethanolamine. You may mix and use more than one kind.

This organic undercoat layer can be provided by the following method. That is, water or methanol, ethanol,
A method in which a solution in which the above organic compound is dissolved in an organic solvent such as methyl ethyl ketone or a mixed solvent thereof is applied to an aluminum plate and dried, and an organic solvent such as water or methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof is used. In this method, an aluminum plate is immersed in a solution in which the above-mentioned organic compound is dissolved to adsorb the above-mentioned compound, and then washed with water or the like and dried to form an organic undercoat layer. In the former method, a solution of the above organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. Also, in the latter method, the concentration of the solution is 0.1.
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 ° C.
And the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this can be adjusted to pH 1 to 12 with a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, or an acidic substance such as hydrochloric acid or phosphoric acid. Further, a yellow dye can be added for improving the tone reproducibility of the image recording material.

The coating amount of the organic undercoat layer is 2 to 200 m
g / m ² is appropriate, and preferably 5 to 100 mg / m ^2.
2 If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² . The lithographic printing plate precursor of the present invention includes:
If necessary, an overcoat layer may be provided on the photosensitive layer. Examples of the overcoat layer component include polyvinyl alcohol, methacrylate, acrylate, and a mat material used for a general photosensitive lithographic printing original plate.

((Infrared Laser)) The lithographic printing original plate prepared as described above is usually subjected to image exposure and development processing. The photosensitive layer according to the present invention has an advantage that a positive image can be formed by an infrared laser. Therefore, in the exposure step (imagewise exposure step), a light source having an emission wavelength of 700 nm or more in the near-infrared to infrared region is preferable as a light source of active light used for image exposure. The light source in the plate making method of the present invention is particularly preferably a solid-state laser or a semiconductor laser capable of irradiating infrared rays having an emission wavelength of 700 to 1200 nm.

((Alkali Development Processing Solution) The alkali development processing solution contains at least one non-reducing sugar and at least one base, and further contains other components as necessary.

When the infrared-sensitive lithographic printing original plate is subjected to development processing using the alkali developing solution, the surface of the photosensitive layer in the infrared-sensitive lithographic printing original plate is not deteriorated, and The meat quality can be maintained in a good state. The infrared-sensitive lithographic printing plate precursor has a narrow developing latitude and a large change in image width and the like depending on the pH of the developing solution.
Since it contains a non-reducing sugar having a buffering property for suppressing the fluctuation of the silicate, it is more advantageous than the conventional case where a developing solution containing silicate is used. Furthermore, since the non-reducing sugar is less likely to contaminate a conductivity sensor, a pH sensor, and the like for controlling the liquid activity than the silicate, the alkali developing solution is also advantageous in this respect.

(Non-Reducing Sugar) The non-reducing sugar is a saccharide having no free aldehyde group or ketone group and showing no reducibility.
Glycosides, in which a reducing group of a saccharide and a non-saccharide are bonded, and sugar alcohols obtained by hydrogenating and reducing a saccharide, are all suitable for use in the present invention. In the present invention, non-reducing sugars described in JP-A-8-305039 can be suitably used.

Examples of the trehalose-type oligosaccharide include saccharose and trehalose. Examples of the glycoside include an alkyl glycoside, a phenol glycoside, and a mustard oil glycoside. Examples of the sugar alcohol include D, L-arabit, ribit, xylit, D, L-sorbit, D, L-mannit, D, L-idit, D, L-tallit, zuricit, allozurcit and the like. . Further, maltitol obtained by hydrogenating disaccharide maltose, a reduced form (reduced starch syrup) obtained by hydrogenating oligosaccharide, and the like are preferably mentioned. Among these non-reducing sugars, trehalose-type oligosaccharides and sugar alcohols are preferable, and among them, D-sorbitol, saccharose, reduced starch syrup, and the like are preferable because they have a buffering action in an appropriate pH range and are inexpensive.

In the present invention, these non-reducing sugars may be used alone or in combination of two or more. The content of the non-reducing sugar in the alkali developing solution is preferably 0.1 to 30% by weight,
20% by weight is more preferred. When the content is less than 0.1% by weight, a sufficient buffering action cannot be obtained, and the content is 30% by weight.
If it exceeds, it will be difficult to achieve high concentration, and there will be a problem of cost increase. When the reducing sugar is used in combination with a base described below,
Because it browns, the pH gradually decreases, and the developability decreases,
Not used in the present invention.

(Base) Examples of the base include conventionally known alkali agents such as inorganic alkali agents and organic alkali agents. Examples of the inorganic alkaline agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, sodium carbonate, and potassium carbonate. , Ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium borate, potassium borate,
Ammonium borate and the like.

Examples of the organic alkali agent include monomethylamine, dimethylamine, trimethylamine,
Monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine,
Examples include triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine, pyridine and the like.

The bases may be used alone or in combination of two or more. Among these bases, sodium hydroxide and potassium hydroxide are preferred. The reason is that by adjusting the amounts of the non-reducing sugars, the pH can be adjusted in a wide pH range. Also, trisodium phosphate, tripotassium phosphate, sodium carbonate, potassium carbonate and the like are preferable since they themselves have a buffering action.

The base is a p
Preferably, 9.0 to 1 so that H becomes alkaline.
More preferably, 10.0 to 13.
2 is added to the alkali developing solution. The content of the base in the alkali developing solution is appropriately determined according to the desired pH, the type of the non-reducing sugar, the amount added, and the like.

In the present invention, as the alkali developing solution, an alkali metal salt of the non-reducing sugar can be used as a main component instead of using the non-reducing sugar in combination with the base. The alkali metal salt of the non-reducing sugar,
Mixing the non-reducing sugar with an alkali metal hydroxide, heating and dehydrating the melting point of the non-reducing sugar or higher, or
It is obtained by drying the mixed aqueous solution of the non-reducing sugar and the alkali metal hydroxide.

In the present invention, an alkaline buffer consisting of a weak acid other than the non-reducing sugar and a strong base can be used in combination with the alkali developing solution. The weak acid preferably has a dissociation constant (pKa) of 10.0 to 13.2. For example, IONISATION CONSTANTS OF issued by Pergamon Press
ORGANIC ACIDS IN AQUEOUS
It can be selected from those described in SOLUTION or the like.

Specifically, 2,2,3,3-tetrafluoropropanol-1 (pKa 12.74), trifluoroethanol (12.37), trichloroethanol (12.24) and the like Alcohols, pyridine-2-
Aldehydes such as aldehyde (12.68) and pyridine-4-aldehyde (12.05), salicylic acid (13.0) and 3-hydroxy-2-naphthoic acid (1)
2.84), catechol (12.6), gallic acid (12.4), sulfosalicylic acid (11.7), 3, 4
-Dihydroxysulfonic acid (12.2), 3,4-dihydroxybenzoic acid (11.94), 1,2,4-trihydroxybenzene (11.82), hydroquinone (11.56), pyrogallol (Id. 11.34),
o-cresol (10.33), resorsonol (11.27), p-cresol (10.27), m-
Compounds having a phenolic hydroxyl group such as cresol (10.09);

2-butanone oxime (12.45);
Acetoxime (12.42), 1,2-cycloheptanedione dioxime (12.3), 2-hydroxybenzaldehyde oxime (12.10), dimethylglyoxime (11.9), ethanediamide dioxime (11.37) and acetophenone oxime (11.37).
Oximes such as 35), adenosine (id. 12.56),
Inosine (12.5), guanine (12.3), cytosine (12.2), hypoxanthine (12.5).
1) nucleic acid-related substances such as xanthine (11.9);

In addition, diethylaminomethylphosphonic acid (12.32), 1-amino-3,3,3-trifluorobenzoic acid (12.29), isopropylidene diphosphonic acid (12.10), 1 1,1-ethylidene diphosphonic acid (11.54), 1,1-ethylidene diphosphonic acid 1-hydroxy (11.52), benzimidazole (12.86), thiobenzamide (12.86).
8), picoline thioamide (12.55), barbituric acid (12.5) and the like are preferred. Among these weak acids, sulfosalicylic acid and salicylic acid are preferred.

Examples of strong bases to be combined with these weak acids include sodium hydroxide, ammonium hydroxide,
Preferable examples include potassium hydroxide and lithium hydroxide. These strong bases may be used alone,
Two or more kinds may be used in combination. The strong base is used after adjusting the pH to a preferred range by appropriately selecting the concentration and combination.

(Other components) In the present invention, a surfactant, if necessary, may be used for the purpose of accelerating the developing property, dispersing the developing residue, and improving the ink affinity of the image area of the photosensitive lithographic printing plate precursor. Development stabilizers, organic solvents, reducing agents, organic carboxylic acids, water softeners and the like, further known preservatives, coloring agents, thickeners, defoamers and the like as other components added to the alkali developing solution. Is also good.

—Surfactant— Examples of the surfactant include a nonionic surfactant, an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and glycerin fatty acid. Partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol Fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylated castor oil, polyoxyethylene glycerin fatty acid Esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides and the like are preferably exemplified.

Examples of the anionic surfactant include fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinic acid ester salts, α-olefinsulfonic acid salts, and linear alkylbenzenesulfonic acid salts. , Branched-chain alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates, polyoxyethylenealkylsulfophenylether salts, N-methyl-N-oleyltaurine sodium salt, N-alkylsulfosuccinic acid Monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfate esters of fatty acid alkyl esters,
Alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyls Ether phosphates, polyoxyethylene alkylphenyl ether phosphates, partially saponified styrene / maleic anhydride copolymers, partially saponified olefin / maleic anhydride copolymers, formalin naphthalene sulfonate Preferable examples include condensates.

Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, polyoxyethylene alkylamine salts, and polyethylenepolyamine derivatives. Examples of the amphoteric surfactant include carboxybetaines, alkylaminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines.

Among the above surfactants, the term "polyoxyethylene" can be read as a polyoxyalkylene such as polyoxymethylene, polyoxypropylene, polyoxybutylene or the like. Is included.

In the present invention, preferred surfactants include fluorine-based surfactants having a perfluoroalkyl group in the molecule. Such fluorosurfactants include perfluoroalkyl carboxylate,
Anionic type such as perfluoroalkyl sulfonate, perfluoroalkyl phosphate, amphoteric type such as perfluoroalkyl betaine, cationic type such as perfluoroalkyltrimethylammonium salt, perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct And oligomers containing perfluoroalkyl groups and hydrophilic groups, oligomers containing perfluoroalkyl groups and lipophilic groups, oligomers containing perfluoroalkyl groups, hydrophilic groups and lipophilic groups, urethanes containing perfluoroalkyl groups and lipophilic groups, etc. Non-ionic types are included.

The surfactants may be used alone or in combination of two or more. The content of the surfactant in the alkali developing solution is usually 0.001 to 10% by weight, and 0.01 to 5% by weight.
Is preferred.

-Development stabilizer-Examples of the development stabilizer include, for example, JP-A-6-282.
Preferred examples include polyethylene glycol adducts of sugar alcohols, tetraalkylammonium salts such as tetrabutylammonium hydroxide, phosphonium salts such as tetrabutylphosphonium bromide, and iodonium salts such as diphenyliodonium chloride. Also, anionic surfactants and amphoteric surfactants described in JP-A-50-51324, water-soluble cationic polymers described in JP-A-55-95946, and JP-A-56-142528 are described. And a water-soluble amphoteric polymer electrolyte.

Further, an organic boron compound to which an alkylene glycol is added described in JP-A-59-84241, and a water-soluble polyoxyethylene / polyoxypropylene block polymerization type described in JP-A-60-111246. Surfactants, polyoxyethylene / polyoxypropylene-substituted alkylenediamine compounds described in JP-A-60-129750, JP-A-61-2155
No. 54, polyethylene glycol having a weight average molecular weight of 300 or more, a fluorinated surfactant having a cationic group described in JP-A-63-175858, an acid or alcohol described in JP-A-2-39157. To 4
Water-soluble ethylene oxide addition compounds obtained by adding at least moles of ethylene oxide, water-soluble polyalkylene compounds, and the like.

—Organic Solvent— The organic solvent preferably has a solubility in water of about 10% by weight or less, more preferably 5% by weight or less. Specific examples of the organic solvent include 1-
Phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-
1-butanol, 2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclohexanol, N
-Phenylethanolamine, N-phenyldiethanolamine and the like.

The content of the organic solvent in the alkali developing solution is about 0.1 to 5% by weight based on the total weight of the alkali developing solution. The content is closely related to the content of the surfactant in the alkali developing solution, and it is preferable that the amount of the surfactant increases as the amount of the organic solvent increases. This means that when the amount of the surfactant is reduced and the amount of the organic solvent is increased, the organic solvent is not completely dissolved,
This is because good developability cannot be expected.

-Reducing Agent- Examples of the reducing agent include an organic reducing agent and an inorganic reducing agent. These reducing agents help prevent the printing plate from being soiled. Preferred specific examples of the organic reducing agent include:
Examples thereof include phenol compounds such as thiosalicylic acid, hydroquinone, metol, methoxyquinone, resorcin and 2-methylresorcin, and amine compounds such as phenylenediamine and phenylhydrazine. Preferred specific examples of the inorganic reducing agent include sodium salts, potassium salts of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, hydrogen phosphite, dihydrophosphite, thiosulfate, and dithionite. , Ammonium salts and the like. Among these, sulfites are preferred because they have particularly excellent stain-preventing effects. The content of the reducing agent in the alkali developing solution is preferably 0.0
It is about 5 to 5% by weight.

—Organic Carboxylic Acid— Examples of the organic carboxylic acid include aliphatic carboxylic acids and aromatic carboxylic acids having 6 to 20 carbon atoms.
Specific examples of the aliphatic carboxylic acid having 6 to 20 carbon atoms include caproic acid, enantiic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, and stearic acid. Among them, alkanoic acids having 8 to 12 carbon atoms are particularly preferred. These may be unsaturated fatty acids having a double bond in the carbon chain, or may be those having a branched carbon chain.

Specific examples of the aromatic carboxylic acids having 6 to 20 carbon atoms include compounds in which a benzene ring, a naphthalene ring, an anthracene ring, or the like is substituted with a carboxyl group. -Chlorobenzoic acid, p-
Chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid Acid, a few
-Dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-naphthoic acid, 3-
Examples thereof include hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-naphthoic acid, and 2-naphthoic acid. Among these, hydroxynaphthoic acid is particularly preferred.

The aliphatic carboxylic acid and the aromatic carboxylic acid are preferably used as a sodium salt, a potassium salt, an ammonium salt or the like from the viewpoint of increasing the water solubility. The content of the organic carboxylic acid in the alkali developing solution is not particularly limited, but is usually 0.1 to 10%.
% By weight, preferably 0.5 to 4% by weight. If the content is less than 0.1% by weight, the effect of the addition is not sufficient. If the content exceeds 10% by weight, the effect corresponding thereto cannot be obtained. Dissolution in the processing solution may be hindered.

-Water softener-Examples of the water softener include polyphosphoric acid and its sodium, potassium and ammonium salts, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, Nitrilotriacetic acid,
1,2-diaminocyclohexanetetraacetic acid, 1,3-
Aminopolycarboxylic acids such as diamino-2-propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylene Examples include tetramine hexa (methylene phosphonic acid), hydroxyethylethylenediamine tri (methylene phosphonic acid), 1-hydroxyethane-1,1-diphosphonic acid, and their sodium, potassium, and ammonium salts.

The optimum content of the water softener in the alkali developing solution varies depending on the chelating power and the hardness and amount of the hard water used.
It is about 0.01 to 5% by weight, preferably 0.01 to 0.5% by weight. If the content is less than 0.01% by weight, the effect of the addition may not be sufficient, and if it exceeds 5% by weight, adverse effects on the image area such as color loss may occur.

The alkali developing solution contains water in addition to the components described above. It is advantageous from the viewpoint of transportation that the alkali developing solution in the present invention is used as a concentrated solution having a reduced water content when not used (during storage) and is diluted with water when used. In this case, the concentration of the alkali developing solution is suitably such that the components do not separate or precipitate. When not used (during storage), it is also preferable to remove the moisture by a spray-drying method or the like, or to use a solid developer mixed with a solid material.

(Development Process) In the present invention, first, the infrared-sensitive lithographic printing plate precursor is exposed by a plate setter equipped with a laser having an emission wavelength in the near infrared to infrared region. After the laser irradiation, the developing process may be performed immediately, but it is preferable to perform a heating process between the laser irradiation and the developing process. The heat treatment is preferably performed at 80 to 150 ° C. for 10 seconds to 5 minutes. This heat treatment can reduce the laser energy required for recording during the laser irradiation.

The infrared-sensitive lithographic printing plate precursor is subjected to the heat treatment as required, and then developed using the above-mentioned alkali developing solution. In the present invention, the alkali developing solution can be used for the development of an ultraviolet / visible light-sensitive lithographic printing plate precursor. A common development process (hereinafter sometimes referred to as “common development process”) can be performed on the printing original using the same alkali developing solution. For this reason, according to the present invention, development processing can be efficiently performed using the same alkali developing solution regardless of the type of the infrared-sensitive lithographic printing original plate or the ultraviolet / visible light-sensitive lithographic printing original plate.

The lithographic printing plate precursors for ultraviolet / visible light irradiation may be, for example, a mercury lamp, metal halide lamp, xenon lamp, chemical lamp, tungsten lamp, carbon arc lamp, argon Exposure processing is performed by a laser, a YAG laser, or the like.

The development process of the infrared-sensitive lithographic printing plate precursor can be suitably applied to an automatic developing machine. In this case, the plate making operation can be streamlined and standardized, which is advantageous. The automatic developing machine generally has a developing unit and a post-processing unit,
A device for transporting the infrared-sensitive lithographic printing plate precursor, each processing solution tank, a spray device, etc., while transporting the exposed infrared-sensitive lithographic printing plate precursor horizontally while pumping up the alkali developing solution, etc. Is sprayed from a spray nozzle to perform development processing and post-processing.

In the present invention, the infrared-sensitive lithographic printing plate precursor may be subjected to a developing process by spraying an alkali developing solution or the like pumped up by a pump from a spray nozzle using a developing device. Further, the developing treatment may be carried out by immersing and transporting in a developing solution tank filled with an alkaline developing solution using a guide roll in the liquid.

After the development processing, the obtained lithographic printing plate is usually post-processed using a rinse solution containing water, a surfactant, etc., a finisher or a protective gum solution mainly containing gum arabic or a starch derivative. Is applied. In the present invention,
These post-treatments can be used in various combinations,
For example, preferred examples include washing → finishing gum treatment, surfactant-containing rinsing liquid → finishing treatment, and two-stage countercurrent finishing gum treatment. In addition,
In the present invention, after the development processing, a fixed amount of a small amount of water may be supplied to the plate surface for washing, and the waste water may be reused as the diluting water for the stock solution of the alkali development processing solution. The developing process may be a continuous system in which the alkali developing solution is appropriately replenished, depending on the amount of the developing process or the operating time, or a so-called disposable process in which the alkali developing solution is treated with substantially unused alkali developing solution. The method may be used.

Unnecessary image portions (for example, film edge traces of the original film) in the lithographic printing plate obtained by the above development processing are erased. Such erasures
For example, a method in which an erasing liquid as described in JP-B-2-13293 is applied to unnecessary image portions, left as it is for a predetermined time, and then washed with water is preferable. A method of irradiating an active image guided by an optical fiber to an unnecessary image portion and then performing development processing as described in the publication can also be used.

The lithographic printing plate can be subjected to a printing step after coating with a desensitizing gum if desired. However, if a lithographic printing plate having a higher printing durability is desired, a burning treatment is performed. You. When the lithographic printing plate is subjected to a burning process, the lithographic printing plate may be burned before the burning process.
No. 8, No. 55-28062, JP-A-62-31859.
And JP-A-61-159655. As a method of the treatment, a method of applying the solution on a lithographic printing plate with a sponge or absorbent cotton impregnated with the surface conditioning solution, or immersing the printing plate in a vat filled with the surface conditioning solution is applied. Also, application by an automatic coater or the like is applied. Further, it is more preferable to make the application amount uniform with a squeegee or a squeegee roller after the application. The coating amount of the surface conditioning liquid is generally 0.03 to 0.8 g / m ^2.
(Dry weight) is appropriate.

The planographic printing plate to which the surface conditioning liquid has been applied is dried, if necessary, and then burned (for example, a burning processor sold by Fuji Photo Film Co., Ltd .: BP-1300) or the like. Is heated to a high temperature. The heating temperature and time in this case depend on the type of the component forming the image, but are 100 to 300 ° C.
For about 1 to 20 minutes. The burning-processed lithographic printing plate can be subjected to a conventional treatment such as washing with water and gumming, if necessary, but a surface preparation containing a water-soluble polymer compound or the like can be performed. When a liquid is used, so-called desensitizing treatment such as gumming can be omitted.

The lithographic printing plate obtained by the above-described processing is applied to an offset printing machine or the like and used for printing a large number of sheets.

The method of making a lithographic printing plate according to the present invention comprises:
Further, the present invention may be applied to plate making of a negative type infrared-sensitive lithographic printing plate. The negative type infrared-sensitive lithographic printing plate comprises (A)
Contains a compound that decomposes by light or heat to generate an acid, (B) a crosslinking agent that crosslinks with an acid, (C) at least one kind of alkali-soluble resin, (D) an infrared absorber, and (E) other additives. Do it. In this negative-type infrared-sensitive lithographic printing plate, energy imparted by a solid-state laser and a semiconductor laser emitting infrared light is converted into thermal energy by an infrared absorber (D), whereby (A) light or heat A compound that decomposes to generate an acid decomposes to generate an acid. The acid promotes the crosslinking reaction between the crosslinking agent (B) and the alkali-soluble resin (C), thereby forming an image.

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EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. -Synthesis of Specific Copolymer- <Synthesis Example 1 (Specific Copolymer 1)> In a 500 ml three-necked flask equipped with a stirrer, a condenser, and a dropping funnel, 31.0 g (0.36 mol) of methacrylic acid, chloroform Ethyl acid 39.1 g (0.36 mol) and acetonitrile 200
ml and the mixture was stirred while cooling in an ice-water bath.
To this mixture, 36.4 g (0.36 mol) of triethylamine was dropped by a dropping funnel over about 1 hour. After completion of the dropwise addition, the ice-water bath was removed, and the mixture was stirred at room temperature for 30 minutes.

To the reaction mixture was added 51.7 g (0.30 mol) of p-aminobenzenesulfonamide, and the mixture was stirred for 1 hour while being heated to 70 ° C. in an oil bath. After the completion of the reaction, this mixture was added to 1 liter of water while stirring the water, and the resulting mixture was stirred for 30 minutes. The mixture was filtered to remove the precipitate, which was then washed with 500 m of water.
Then, the slurry was filtered, and the obtained solid was dried to obtain a white solid of N- (p-aminosulfonylphenyl) methacrylamide (yield 46.9 g).

Next, 4.61 g of N- (p-aminosulfonylphenyl) methacrylamide was placed in a 20 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel.
192 mol), 2.94 g of ethyl methacrylate (0.0
258 mol), 0.80 g of acrylonitrile (0.01
5 mol) and 20 g of N, N-dimethylacetamide, and the mixture was stirred while being heated to 65 ° C. in a water bath. This mixture was mixed with “V-65” (manufactured by Wako Pure Chemical Industries, Ltd.).
0.15 g was added, and the mixture was stirred for 2 hours under a nitrogen stream while maintaining at 65 ° C. The reaction mixture is further charged with N-
A mixture of 4.61 g of (p-aminosulfonylphenyl) methacrylamide, 2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile, 0.15 g of N, N-dimethylacetamide and 0.15 g of "V-65" was dropped by a dropping funnel over 2 hours. It was dropped. After the addition was completed, the resulting mixture was further stirred at 65 ° C. for 2 hours. After the completion of the reaction, 40 g of methanol was added to the mixture, and the mixture was cooled.
This water was added to a liter with stirring, and after stirring the mixture for 30 minutes, the precipitate was taken out by filtration and dried to obtain 15 g of a white solid (specific copolymer 1). The weight average molecular weight (polystyrene standard) of this specific copolymer 1 measured by gel permeation chromatography was 53,000.

(Example 1) An aluminum plate (material 1050) having a thickness of 0.3 mm was washed with trichlorethylene and degreased, and then its surface was grained using a nylon brush and a 400 mesh pumice-water suspension. And washed well with water. This aluminum plate was immersed in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds to perform 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 is about 3 g /
m ² . Next, a 3 g / m ² direct current anodic oxide film was formed on the aluminum plate at a current density of 15 A / dm ² using 7% sulfuric acid as an electrolytic solution. For 30 seconds at 30 ° C., the following undercoating solution was applied, and the coating film was dried at 80 ° C. for 15 seconds to obtain a support having an undercoat layer formed thereon. The coating amount of the undercoat layer after drying was 15 mg / m ² .

—Composition of Undercoating Solution— Compound shown below (Formula 5): 0.3 g Methanol: 100 g Water・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 1g

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On the undercoat layer of the obtained support, the following photosensitive layer coating solution [a] was applied so that the coating amount was 1.8 g / m ² , and the positive type infrared-sensitive lithographic printing plate precursor [ A]
I got This was cut into a size of 1003 mm x 800 mm to prepare a large number of sheets.

—Coating solution of photosensitive layer [a] —Specific copolymer 1 ··· 0.75 g m, p-cresol novolak ··· 0.25 g (M, p ratio = 6/4, weight average molecular weight 3,500, unreacted cresol 0.5% by weight) p-toluenesulfonic acid 0.003 g tetrahydrophthalic anhydride 0.03 g Cyanine dye A (the following structure) 0.017 g Dye in which the counter ion of Victoria Pure Blue BOH is 1-naphthalenesulfonic acid anion 0.01 g g Megafac F-177 0.05 g (a fluorosurfactant manufactured by Dainippon Ink and Chemicals, Inc.) γ-butyl lactone・ ・ ・ ・ ・ ・ ・ ・ 10g Methyl ethyl keto ············ 10 g 1-methoxy-2-propanol · · · · · · 1 g

[0131]

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The obtained infrared-sensitive lithographic printing plate precursor [A]
With an output of 500 mW, a wavelength of 830 nm, and a beam diameter of 17 μm
m (1 / e ² ) using a semiconductor laser with a main scanning speed of 5
Exposure was performed at m / sec. Next, 20 liters of an alkali developing solution A (pH about 13) having the following composition was charged into a developing tank of a commercially available automatic developing machine PS-900NP (manufactured by Fuji Photo Film Co., Ltd.) having an immersion type developing tank. The temperature was kept at 30 ° C. In the second bath of PS-900NP, 8 liters of tap water and in the third bath, 8 liters of finishing gum solution diluted with FP-2W (manufactured by Fuji Photo Film Co., Ltd.): Water = 1: 1. I charged.

—Composition of Alkaline Developing Solution A— D-Sorbit 2.5 wt% sodium hydroxide 0.85 Wt% Diethylenetriaminepenta (methylenephosphonic acid) 5Na salt ··· 0.05 wt% Water ··· 96.6 wt%

Assuming that the developing replenishment control impedance value in the automatic developing machine PS-900NP is 40.5 ms / cm,
While replenishing the following development replenisher a, the exposed infrared-sensitive lithographic printing plate precursor [A] is 160 plates per day,
Development processing was performed for 3 months. When the line width of the reference fine line (8 μm) on the lithographic printing plate obtained by this development treatment was measured,
No change was observed from the start of the development processing to after three months of processing. Further, when the obtained lithographic printing plate was printed with an offset printing machine Sprint 25 (manufactured by Komori Printing Machinery Co., Ltd.), the ink deposition was good, and 1
A beautiful print without stain was obtained with 5 sheets, followed by 7
10,000 satisfactory prints were obtained.

—Composition of Development Replenisher A— D-Sorbit 5.6% by weight of potassium hydroxide 5 wt% diethylenetriaminepenta (methylenephosphonic acid) 5Na salt ··· 0.2 wt% water ··· 91.7 wt%

(Comparative Example 1) In Example 1, the following developing solution B and developing replenisher B were used in place of the alkali developing solution A and the developing replenisher A, and the impedance value was set to 56 ms / cm. Developed an exposed infrared-sensitive lithographic printing plate precursor [A] under the same conditions as in Example 1. One month after the start of the development processing, the fine line width was reduced to 6 μm, and in the second month, the image surface was eroded and started to become thin.
Further, when the obtained lithographic printing plate was printed with an offset printing machine Sprint 25 (manufactured by Komori Printing Machinery Co., Ltd.), a satisfactory printed matter was obtained with 75 sheets from the start of processing at the start of processing. 10,000 prints were obtained. However, from the planographic printing plate obtained after the three-month treatment, about 100 printings were required to obtain a satisfactory printed matter. The image was worn when 45,000 sheets were printed, and no further printing was possible.

—Composition of Developing Solution— A [SiO ₂ ] / [K ₂ O] molar ratio of 1.16, 1.4 wt% of SiO ₂ aqueous sodium silicate solution · 99.9 wt% of diethylenetriaminepenta (methylenephosphone) Acid) 5Na salt 0.1% by weight

—Composition of Developing Replenisher Solution— A [SiO ₂ ] / [K ₂ O] molar ratio of 0.98, 2.0 wt% of SiO ₂ aqueous sodium silicate solution · 99.8 wt% of diethylenetriaminepenta (methylenephosphone) Acid) 5Na salt 0.2% by weight

(Example 2) A photosensitive layer coating solution [b] having the following composition was applied to the same support as in Example 1 so that the coating amount was 1.8 g / m ² , and dried to obtain a photosensitive layer. Was formed to obtain an infrared-sensitive lithographic printing original plate [B].

—Composition of Photosensitive Layer Coating Solution [b] —Specific Copolymer 1 0.4 gm, p-cresol novolak 0.6 g (m, p ratio = 6/4, weight average molecular weight 3,500, unreacted cresol 0.5% by weight) p-toluenesulfonic acid 003 g Tetrahydrophthalic anhydride 0.03 g Cyanine dye B (structure below) 0.017 g Counter ion of ethyl violet (manufactured by Orient Chemical Industry Co., Ltd.) 1-naphthalenesulfonic acid anion dye 0.015 g Megafac F-177 0.05 g (Dainippon Ink and Chemicals, Inc. Co., Ltd., fluorinated surfactant) γ-butyl lactone ... 10 g Methyl ethyl ketone ... 10 g 1-methoxy-2-propanol ... 3 g

[0141]

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The infrared-sensitive lithographic printing plate precursor [A]
The same development processing as in Example 1 was performed except that [B] was used in place of. From the resulting lithographic printing plate, a beautiful printed matter could be obtained with only 15 sheets from the start of printing.

(Example 3) In the photosensitive layer coating solution [a] used in Example 1, as a substance which is thermally decomposable and which substantially reduces the solubility of the alkali aqueous solution-soluble polymer compound when not decomposed. Ester compound of naphthoquinone-1,2-diazide-5-sulfonyl chloride and pyrogallol-acetone resin (US Pat. No. 3,635,709)
Described in Example 1 of the specification) 0.20 g
A lithographic printing plate was obtained in the same manner as in Example 1 except that was added. From the lithographic printing plate obtained, only 15
A beautiful printed matter was obtained with one sheet.

Example 4 A positive infrared-sensitive lithographic printing plate precursor [A] was prepared in the same manner as in Example 1 except that the alkali developing solution A was replaced with an alkali developing solution C having the following composition. ] Was developed. As a result, good results were obtained as in Example 1.

—Composition of Alkali Developing Solution C— D-Sorbit 2.5 wt% Potassium Hydroxide 1.3% by weight Diethylenetriaminepenta (methylene phosphonic acid) 5Na salt 0.1% by weight Water 96.1% by weight

Further, in order to confirm whether or not the alkali developing solution of the present invention can be used in the development of an ultraviolet / visible light-sensitive lithographic printing plate precursor, a positive-type ultraviolet-sensitive lithographic printing plate precursor [C] described later is used. Was subjected to a development process using the above-mentioned alkali developing solution C.

<Positive UV-sensitive lithographic printing plate precursor [C]
> An aluminum plate having a thickness of 0.24 mm was grained with a nylon brush and a 400 mesh pumicestone-water suspension, and then thoroughly washed with water. 1
After etching by dipping in 0% sodium hydroxide at 70 ° C. for 20 seconds, the substrate was washed with running water, then neutralized with 20% HNO ₃ and washed with water. This was subjected to electrolytic surface roughening treatment in a 0.7% nitric acid aqueous solution at an electric quantity of 400 coulomb / dm ² using a sine wave alternating current under the condition of VA = 12.7V. This aluminum plate was dissolved in a 10% aqueous sodium hydroxide solution so that the amount of aluminum dissolved on the surface was 0.9 g /
I was treated to be m ^2. After washing with water, neutralizing and washing in a 20% nitric acid solution to remove smut, 18% H ₂ SO
₄ Anodizing was performed in an aqueous solution so that the amount of the oxide film was 3 g / m ² . Next, a hydrophilization treatment was performed at 35 ° C. with a 2% aqueous solution of sodium silicate. On the support obtained as described above, an undercoating solution having the following composition was dried at a weight of 10 mg / m 2.
² and dried at 90 ° C. for 1 minute to form an undercoat layer.

-Composition of Undercoat Liquid-Phenylphosphonic acid 0.06 g Sulfuric acid ...・ 0.12g methanol ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 100g

Subsequently, a photosensitive layer coating solution [c] having the following composition was prepared, and the photosensitive layer was provided on the undercoat layer of the support so that the weight after drying was 1.8 g / m ² .

-Composition of Photosensitive Layer Coating Solution [c]-Phenol-formaldehyde resin 1.9 g (content of trinuclear or higher components: 94.6% by weight, molecular weight: 12,500) Esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin (molecular weight: 2,500) ... 0.76 g Tetrahydrophthalic anhydride ... 0.2 g 4- [p-N- (p-hydroxybenzoyl) aminophenyl] -2,6-bis (trichloromethyl) -s-triazine 0.02 g Victoria Pure Blue BOH 0.03 g (made by Hodogaya Chemical Industries) Megafac F-177 0.006 g (made by Dainippon Ink and Chemicals, fluorine-based surfactant) Ethyl ketone .............. 15 g of propylene glycol monomethyl ether · · · · 15 g

A mat layer was formed by spraying a resin solution for forming a mat layer on the surface of the photosensitive layer as described below to obtain a positive type ultraviolet-sensitive lithographic printing plate precursor [C]. As a resin solution for forming a mat layer, a 12% aqueous solution in which a part of a copolymer of methyl methacrylate / ethyl acrylate / acrylic acid (charge ratio = 65: 20: 15) was prepared as a sodium salt, was subjected to rotary atomization static electricity. Atomizing head rotation speed of 25,000r with a coating machine
pm, the amount of resin solution sent is 40 ml / min, the voltage applied to the atomizing head is -90 kv, the ambient temperature during application is 25 ° C, and the relative humidity is 50%. Steam is applied to wet, and 3 seconds after moistening, the temperature is 60 ° C.
Hot air with a humidity of 10% was blown for 5 seconds to dry. The height of the mat is about 6 μm, the size is about 30 μm, and the number is 15
It was 0 pieces / mm ² . The photosensitive lithographic printing original plate [C] thus obtained was cut into a large number of 1003 mm × 800 mm, and a large number of these were cut through a manuscript film using a 3 kW metal halide lamp from a distance of 1 m. Exposure for seconds.

Next, the alkali developing solution (pH about 1) was placed in a developing tank of a commercially available automatic developing machine PS-900NP (manufactured by Fuji Photo Film Co., Ltd.) having an immersion developing tank.
3.1) was charged in 20 liters and kept at 30 ° C. P
In the second bath of S-900NP, 8 liters of tap water,
In the third bath, FP-2W (Fuji Photo Film Co., Ltd.)
8 liters of a finishing gum solution diluted with water = 1: 1. Further, the development replenishment control impedance value of the built-in automatic developing machine PS-900NP is 40.5 ms / cm.
The positive type ultraviolet-sensitive lithographic printing plate precursor [C] was subjected to development processing for 40 plates per day while replenishing the developing replenisher A used in Example 1.

At the time of image exposure, a step tablet (one step having an optical density difference of 0.15 and 15 steps) was simultaneously printed and developed. At the start of the development process, the number of remaining image steps (clear / solid step number) corresponding to the amount of light on the plate is read, and the value is defined as the sensitivity of the ultraviolet-sensitive lithographic printing plate [C]. This variation in sensitivity was investigated. as a result,
Even after 3 months, there was no change in sensitivity, and a stable image was obtained. After processing for three months, the alkali developing solution was removed from the developing tank, and no scum or sludge was found in the developing tank. When the obtained lithographic printing plate was printed by the above-mentioned offset printing machine Sprint 25 (manufactured by Komori Printing Machinery Co., Ltd.), a beautiful printed matter having excellent ink depositing property for printing and no stain was obtained. Was done.

Example 5 An overcoat solution having the following composition was coated on the photosensitive layer of the positive-working infrared-sensitive lithographic printing plate precursor [A] of Example 1 in an amount of 0.2 g / m 2 after drying. ^{2. An} infrared-sensitive lithographic printing plate precursor [A] on which an overcoat layer was formed by coating and drying so as to obtain No. 2
And [A] were obtained. The obtained photosensitive lithographic printing plate precursor [A
] And [A] were subjected to scanning exposure using a semiconductor laser emitting an infrared ray having a wavelength of about 820 to 850 nm and having an energy amount of 200 mJ / cm ² . After the exposure, a heat treatment was performed at 110 ° C. for 30 seconds using a panel heater. Next, a commercially available automatic developing machine PS having an immersion type developing tank
Into a developing tank of -900NP (manufactured by Fuji Photo Film Co., Ltd.), 20 liters of the alkali developing solution C (pH about 13.1) used in Example 4 was charged and kept at 30 ° C.
In the second bath of PS-900NP, 8 liters of tap water, and in the third bath, 8 liters of finishing gum solution diluted with FP-2W (manufactured by Fuji Photo Film Co., Ltd.): Water = 1: 1. I charged. The above-mentioned exposed and heated infrared-sensitive lithographic printing plate precursors [A] and [A] were passed through the thus-prepared automatic developing machine PS-900NP to carry out development processing. The obtained lithographic printing plate is set on an offset printing machine Sprint 25 (manufactured by Komori Press Co., Ltd.),
When printing was performed, good prints were obtained on all 16 sheets from the start of printing. The infrared-sensitive lithographic printing plate precursor had a problem in that the scratched portion of the photosensitive layer applied before development was dissolved during development and an image was lost, but this was solved by providing the overcoat layer. .

-Composition of overcoat liquid-PVA-205 ... 2.5% by weight (manufactured by Kuraray, polyvinyl alcohol) Megafac F-177 ... 0.03% by weight (fluorinated nonionic surfactant manufactured by Dainippon Ink and Chemicals, Inc.) Water・ 97.47% by weight

—Composition of Overcoat Solution— Partial Sodium Salt of Methyl Methacrylate / Ethyl Acrylate / 2-Acrylamido-2-methylpropanesulfonic Acid (70:15:15 Weight Ratio in Charge) ... 2.5% by weight Megafac F-177 0.03% by weight (Fluorine nonionic surfactant manufactured by Dainippon Ink and Chemicals, Inc.) ) Water: 97.47% by weight

[0157]

According to the present invention, the above-mentioned conventional problems can be solved, and lithographic printing using a development processing method suitable for an infrared-sensitive lithographic printing original plate which can be directly drawn by an infrared laser. A plate making method can be provided. When the infrared-sensitive lithographic printing original plate was treated with the conventional silicate developing solution, the ink-sensitivity of the lithographic printing plate was significantly inferior, but the infrared-sensitive lithographic printing original plate was treated with the alkali developing solution of the present invention. In this case, the inking property is improved to the same level as the conventional ultraviolet / visible light-sensitive lithographic printing plate precursor, and further complements the narrow allowable development range of the infrared-sensitive lithographic printing plate precursor to obtain a printing plate that is always stable. it can. Moreover, the alkali developing solution is a conventional ultraviolet /
It is also suitable for developing a visible light-sensitive lithographic printing original plate, and it is possible to perform a common developing process for an infrared-sensitive lithographic printing original plate and an ultraviolet / visible light-sensitive lithographic printing original plate at the same time. Therefore, according to the present invention, space and labor can be saved. Further, according to the present invention, even when the developing solution is used for a long time, scum and sludge hardly occur, and it is particularly suitable for processing using an automatic developing machine.

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Claims (3)

[Claims] 1. A step of exposing a lithographic printing plate precursor having a photosensitive layer obtained by applying a positive photosensitive composition for an infrared laser on a hydrophilic support with an infrared laser; And a step of developing with an alkaline developing solution containing at least one base. 2. The positive photosensitive composition for an infrared laser,
The method of making a lithographic printing plate according to claim 1, comprising the following (A) to (C). (A) at least one kind of an aqueous alkaline solution-soluble polymer compound having at least one of the following functional groups (a-1) to (a-3): (A-1) a phenolic hydroxyl group, (a-2) a sulfonamide group, and (a-3) an active imide group. And (B) a compound which, when compatible with the aqueous alkali-soluble polymer compound, reduces the solubility of the polymer compound in an aqueous alkaline solution and reduces the solubility lowering effect by heating. (C) a compound that absorbs light and generates heat. And (B) a compound which, by being compatible with the alkali aqueous solution-soluble polymer compound, reduces the solubility of the polymer compound in an alkali aqueous solution, and reduces the solubility lowering effect by heating. The method of making a lithographic printing plate according to claim 2, wherein (C) one compound having both properties is contained in place of the compound having a function of absorbing light to generate heat.