JP2001341448A - Original plate for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for a lithographic printing plate which exhibits good press developing properties and has high sensitivity and high plate wear and can prevent sticking between plates when they are stored by pilling up from being generated. SOLUTION: This original plate has a heat-sensitive layer including microcapsules containing a compound with a functional group being reactive by heating and a water-soluble overcoat layer on the heat-sensitive layer, and the dynamic frictional coefficient when one face is slid on another face is below 2.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a negative type lithographic printing plate precursor. More specifically, plate making by scanning exposure based on digital signals is possible, and it is possible to give printed matter with high sensitivity, high printing durability and no stain, and to print directly by attaching it to a printing machine without developing. Lithographic printing plate precursor that can be used.

[0002]

2. Description of the Related Art Numerous studies have been made on printing plates for computer-to-plate systems, which have been remarkably advanced in recent years. Among them, with the aim of further streamlining the process and solving the problem of waste liquid treatment, development-free lithographic printing plate precursors that can be mounted on a printing machine and printed without developing after exposure have been studied, and various methods have been studied. Proposed.

[0003] One of the methods for eliminating the processing step is to mount an exposed printing plate precursor on a cylinder of a printing press, and supply a dampening solution and ink while rotating the cylinder. There is a method called on-press development for removing an image portion. In other words, the printing plate precursor is mounted on a printing machine as it is after exposure, and the processing is completed in a normal printing process. A lithographic printing plate precursor suitable for such on-press development has a photosensitive layer that is soluble in fountain solution and ink solvent, and is suitable for development on a printing machine placed in a bright room. It is required to have a light room handling property.

For example, Japanese Patent No. 2938397 discloses a lithographic printing plate precursor in which a photosensitive layer in which fine particles of a thermoplastic hydrophobic polymer are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support. ing. In this publication,
In the lithographic printing plate precursor, an image is formed by exposing the thermoplastic hydrophobic polymer particles by heat by exposing the plate to an infrared laser and then mounting the plate on a printing press cylinder, and printing with a dampening solution and / or ink. It is described that the above can be developed. However, in such a method of forming an image simply by heat coalescence, although good on-press developability is exhibited, printing durability is insufficient due to low image strength. Further, when the heat-sensitive layer is provided directly on the aluminum substrate, the generated heat is taken away by the aluminum substrate, so that coalescence due to heat does not occur on the interface between the substrate and the heat-sensitive layer, resulting in insufficient printing durability.

[0005] JP-A-9-127683 and JP-A-9-9-1
23387, JP-A-9-123388, JP-A-9-
JP-A-131850 and WO99-10186 also describe that a printing plate is produced by on-press development after the thermoplastic fine particles are united by heat, but similarly the image strength is weak and the printing durability is insufficient. There is a problem.

[0006]

On the other hand, it has been proposed to provide an overcoat layer of a hydrophilic resin on the heat-sensitive layer in order to prevent contamination of the surface of the heat-sensitive layer. However, when a lithographic printing plate precursor having an overcoat layer is stacked and stored on the heat-sensitive layer containing the particle component, there is a problem that the lithographic printing plate precursor sticks on the front surface and the back surface. This phenomenon is considered to occur because the particle component and the hydrophilic resin in the heat-sensitive layer cry to the overcoat layer (migration) when stored for a long time.

Accordingly, it is an object of the present invention to provide a lithographic printing plate precursor that overcomes the disadvantages of the prior art as described above. That is, on-press developability is good, high sensitivity,
Another object of the present invention is to provide a lithographic printing plate precursor that has high printing durability and can prevent sticking between plates during stacking and storage.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, have found that the following constitution can be used to overcome the disadvantages of the prior art. That is, the present invention is as follows. (1) a heat-sensitive layer including a microcapsule containing a compound having a functional group that reacts by heat on a support;
A water-soluble overcoat layer is provided on the heat-sensitive layer, and the coefficient of dynamic friction when one surface slides on the other surface is 2.
An original plate for a lithographic printing plate, wherein the number is 5 or less. (2) The lithographic printing plate precursor as described in (1) above, wherein the water-soluble overcoat layer contains a light-to-heat conversion material. (3) The lithographic printing plate precursor as described in (1) or (2) above, wherein the water-soluble overcoat layer contains a compound having at least one of a fluorine atom and a silicon atom.

The lithographic printing plate precursor according to the present invention comprises a heat-sensitive layer on a support containing microcapsules containing a compound having a heat-reactive group and a hydrophilic polymer binder. By providing an overcoat layer made of a water-soluble polymer compound on the surface of the formed overcoat layer, by satisfying that the coefficient of dynamic friction described below is 2.5 or less, while exhibiting good on-press developability, The film strength of the image area heated by heat mode exposure or the like is improved, and the printing durability is excellent. Furthermore, it has become possible to prevent sticking between planographic printing plate precursors during long-term stacking storage caused by the water-soluble polymer compound. In addition,
The kinetic friction coefficient of the surface of the lithographic printing plate precursor or the overcoat layer in the present invention is measured by a measuring method according to standard ASTM D1894. That is, the lithographic printing plate precursor is placed such that the surface of the underlying material is in contact with the back surface of the overlying material. The back surface of the material means a surface on which the heat-sensitive layer / water-soluble overcoat layer is not provided on the support, and the front surface means a surface on which the heat-sensitive layer / overcoat layer is provided on the support. . Regarding the same coefficient of friction, 3000 sheets were stacked at 35 ° C and 75% temperature and humidity.
After standing for days, the bottom sample was measured. In the present invention, from the viewpoint of transportability, the numerical range of the dynamic friction coefficient (μk) is 2.5 or less, preferably 0.03 or more and 1.2 or less. The above dynamic friction coefficient has a releasability that retains hydrophilicity, can be easily removed at the time of printing, and prevents sticking between plates during storage, and has a microcapsule and a hydrophilic resin in the image forming layer. Could be found by intensive studies on an overcoat layer capable of exhibiting a barrier property (shielding property) capable of preventing migration.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, the heat-sensitive layer of the lithographic printing plate precursor according to the invention will be described.

[Microcapsules encapsulating a compound having a heat-reactive group] The microcapsules contained in the heat-sensitive layer of the lithographic printing plate precursor according to the present invention include a compound having a heat-reactive group. Compounds having this heat-reactive functional group include polymerizable unsaturated groups, hydroxyl groups, carboxyl groups or carboxylate groups or acid anhydrides,
Examples include compounds having at least one functional group selected from an amino group, an epoxy group, an isocyanate group or a block thereof.

As the compound having a polymerizable unsaturated group,
At least one ethylenically unsaturated bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group;
And preferably two or more compounds. Such a compound group is widely known in the industrial field, and in the present invention, these can be used without particular limitation. These are, in chemical form, monomers, prepolymers, ie dimers, trimers and oligomers, or mixtures or copolymers thereof.

Examples include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids and fatty acids. Esters with aliphatic polyhydric alcohols and amides of unsaturated carboxylic acids with aliphatic polyhydric amines. Also,
An addition reaction product of an unsaturated carboxylic acid ester or unsaturated carboxylic acid amide having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group with a monofunctional or polyfunctional isocyanate or an epoxide; A dehydration-condensation reaction product with a functional carboxylic acid is also preferably used. Further, an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group, and a monofunctional or polyfunctional alcohol,
Addition reactants with amines and thiols, and also substituted reactants with unsaturated carboxylic esters or amides having a leaving group such as a halogen group or a tosyloxy group, and monofunctional or polyfunctional alcohols, amines and thiols. It is suitable. Another preferred example is a compound in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid or chloromethylstyrene.

Specific examples of the polymerizable compound which is an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate,
3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane tris (acryloyloxypropyl) ether, trimethylolethane Triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate,
Pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate,
Examples thereof include sorbitol pentaacrylate, sorbitol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, and polyester acrylate oligomer.

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloyloxy-2 Hydroxypropoxy) phenyl]
Examples include dimethylmethane and bis- [p- (methacryloyloxyethoxy) phenyl] dimethylmethane.

Examples of the itaconic acid ester include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
Examples thereof include 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, and sorbitol tetritaconate.

The crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like can be mentioned. Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Maleic esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate,
Sorbitol tetramalate and the like can be mentioned.

Examples of other esters include, for example, JP-B-46-27926, JP-B-51-47334,
Aliphatic alcohol esters described in JP-A-57-196231, JP-A-59-5240 and JP-A-59-196231
Examples thereof include those having an aromatic skeleton described in JP-A-5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613.

Specific examples of the amide monomer of an aliphatic polyamine compound and an unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples thereof include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, and xylylenebismethacrylamide. Examples of other preferred amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

A urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group is also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups in one molecule and an unsaturated monomer having a hydroxyl group represented by the following formula (I) added to one molecule. Urethane compounds containing at least two polymerizable unsaturated groups are exemplified. Formula (I) CH ₂ ＣC (R ¹ ) COOCH ₂ CH (R ² ) OH (where R ¹ and R ² represent H or CH ₃ )

Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, and JP-B-58-4.
9860, JP-B-56-17654, JP-B-62-
Urethane compounds having an ethylene oxide skeleton described in 39417 and JP-B-62-39418 are also preferable.

Further, radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909, and JP-A-1-105238 are preferable. It can be mentioned as.

Other preferred examples include polyester acrylates and epoxy resins described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. Examples thereof include polyfunctional acrylates and methacrylates such as epoxy acrylates obtained by reacting a resin with (meth) acrylic acid. In addition, JP-B-46-43946,
Specific unsaturated compounds described in JP-B-1-40337 and JP-A-1-40336, and vinylphosphonic acid-based compounds described in JP-A-2-25493 can also be mentioned as preferable ones. In some cases, compounds containing a perfluoroalkyl group described in JP-A-61-22048 are also preferably used. In addition, Journal of the Adhesion Society of Japan, Vol. 20, No. 7, pages 300-308 (198
Those introduced as photocurable monomers and oligomers in (4 years) can also be suitably used.

Suitable epoxy compounds include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene diglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, bisphenols or polyphenols or hydrogenated products thereof. And polyglycidyl ether.

Suitable isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, cyclohexane phenylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, cyclohexyl diisocyanate, or alcohol Alternatively, a compound blocked with an amine can be mentioned.

Suitable amine compounds include ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, propylenediamine, polyethyleneimine and the like.

Suitable compounds having a hydroxyl group include compounds having a terminal methylol group, polyhydric alcohols such as pentaerythritol, and bisphenols and polyphenols. Preferred compounds having a carboxyl group include pyromellitic acid, trimellitic acid, aromatic polycarboxylic acids such as phthalic acid,
Examples thereof include aliphatic polycarboxylic acids such as adipic acid. Preferred acid anhydrides include pyromellitic anhydride,
Benzophenone tetracarboxylic anhydride and the like.

Preferred examples of the copolymer of the ethylenically unsaturated compound include a copolymer of allyl methacrylate. For example, an allyl methacrylate / methacrylic acid copolymer, an allyl methacrylate / ethyl methacrylate copolymer, an allyl methacrylate / butyl methacrylate copolymer, and the like can be given.

As a method for microencapsulation, a known method can be applied. For example, as a method for producing microcapsules, US Pat.
U.S. Pat. No. 3,287,154, U.S. Pat. No. 3,287,154.
No. 38-19574, JP-B-42-446, JP-B-42-711, a method by precipitation of a polymer shown in U.S. Pat. Nos. 3,418,250 and 3,660,304, U.S. Pat. No. 3,796,669. U.S. Pat. No. 3,914,511, U.S. Pat. No. 4,087,376, U.S. Pat. No. 4,089,802, a method using an isocyanate polyol wall material as disclosed in U.S. Pat.
Method using resorcinol-based wall forming material, US Pat.
No. 025445, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, Japanese Patent Publication Nos. 36-9163 and 51-9079, an in situ method by monomer polymerization, and British Patent 930.
No. 422, U.S. Pat. No. 3,111,407, Spray drying method, British Patent Nos. 952807, 96707
No. 4, but not limited thereto.

The preferred microcapsule wall used in the present invention has three-dimensional crosslinks and has a property of swelling by a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. A compound having a thermoreactive functional group may be introduced into the microcapsule wall.

The average particle size of the above microcapsules is
0.01 to 20 μm is preferred, and 0.05 to
2.0 μm is more preferred, and 0.10 to 1.0 μm is particularly preferred. If the average particle size is too large, the resolution will be poor,
On the other hand, if it is too small, the stability over time deteriorates. In such microcapsules, the capsules may or may not be united by heat. The point is that, among the microcapsule inclusions, those that have oozed out of the capsule surface or the outside of the microcapsules during application, or those that have penetrated into the microcapsule wall, may cause a chemical reaction by heat. It may react with the added hydrophilic resin or the added low molecular compound. The microcapsules may be reacted with each other by providing two or more types of microcapsules with functional groups that react with each other with different functional groups. Therefore, it is preferable from the viewpoint of image formation that the microcapsules are melted and united by heat, but it is not essential.

The amount of the microcapsules added to the heat-sensitive layer is as follows:
It is preferably from 10 to 60% by weight, more preferably from 15 to 40% by weight in terms of solid content. Within this range, good sensitivity and printing durability can be obtained simultaneously with good on-press developability.

When the microcapsules are added to the heat-sensitive layer, a solvent capable of dissolving the inclusions and swelling the wall material can be added to the microcapsule dispersion medium. Such a solvent promotes the diffusion of the encapsulated compound having a thermoreactive functional group out of the microcapsules. Such a solvent depends on the microcapsule dispersion medium, the material, wall thickness, and inclusions of the microcapsule wall, but can be easily selected from many commercially available solvents. For example, in the case of water-dispersible microcapsules composed of crosslinked polyurea and polyurethane walls, alcohols,
Preferred are ethers, acetals, esters, ketones, polyhydric alcohols, amides, amines, fatty acids and the like.

Specific compounds include methanol, ethanol, tertiary butanol, n-propanol, tetrahydrofuran, methyl lactate, ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, and γ-butyl lactone. , N, N-dimethylformamide, N, N-dimethylacetamide, etc., but are not limited thereto. Two or more of these solvents may be used.

A solvent which does not dissolve in the microcapsule dispersion but can be dissolved by mixing the above-mentioned solvent can be used. The amount of addition is determined by the combination of materials. If the amount is less than the appropriate value, image formation becomes insufficient, and if the amount is too large, the stability of the dispersion is deteriorated. Normal,
An effective range of 5 to 95% by weight of the coating solution is preferable.
10 to 90% by weight, more preferably 15 to 85% by weight.

[Hydrophilic resin] A hydrophilic resin may be added to the heat-sensitive layer of the lithographic printing plate precursor according to the invention. The addition of the hydrophilic resin not only improves the on-press developability,
The film strength of the heat-sensitive layer itself also increases. 3 as hydrophilic resin
Those having no dimensional cross-linking are preferable because of good on-press developability. As the hydrophilic resin, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl, carboxymethyl and the like are preferable. As specific hydrophilic resins, gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and their Na
Salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids and salts thereof,
Polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, homopolymers of hydroxybutyl methacrylate And copolymers, homopolymers and copolymers of hydroxybutyl acrylate, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight.
Of polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide homopolymer and copolymer, methacrylamide homopolymer and polymer, N-methylol acrylamide homopolymer and copolymer, 2-acrylamide-2-methylpropanesulfonic acid And a homopolymer and a copolymer thereof, and the like.

The amount of the hydrophilic resin added to the heat-sensitive layer is 2%
-40% is preferable, and 3% -30% is more preferable.
If it is less than 2%, the film strength is low, and if it is more than 40%, on-press developability is improved, but printing durability is deteriorated.

[Compound that Initiates or Promotes the Reaction] In the heat-sensitive layer of the lithographic printing plate precursor according to the invention, microcapsules containing the compound having a heat-reactive group described above are used. A compound that initiates or accelerates the reaction may be added. Examples thereof include compounds that generate radicals or cations by heat.Onium salts containing lophine dimer, trihalomethyl compound, peroxide, azo compound, diazonium salt or diphenyliodonium salt, acylphosphine, imidosulfo Nart and the like.
These compounds are present in the heat-sensitive layer in an amount of from 1% by weight to 20% by weight.
Can be added. Preferably from 3% by weight
It is in the range of 10% by weight. If it is more than this, the on-press developability will be poor, and if it is less than this, the effect of initiating or accelerating the reaction will be weakened and the printing durability will deteriorate.

When a microcapsule containing a compound having a heat-reactive group is used, it is preferable that a compound that initiates or accelerates the reaction be contained in the microcapsule in order to promote the reaction efficiently. By including these compounds in the microcapsules, the microcapsules can be preliminarily mixed with the compound having a heat-reactive group, and when irradiated with laser, the reaction can be performed while the inclusions are diffused. Thereby, the printing durability of the lithographic printing plate precursor of the present invention can be further improved.

[Other Additives] In the present invention, various compounds other than those described above may be further added to the heat-sensitive layer, if necessary. For example, a low molecular compound having a functional group capable of reacting with the compound having a thermoreactive group contained in the microcapsule and a protective group thereof can be contained. The addition amount of these compounds is preferably 5% by weight to 40% by weight in the heat-sensitive layer, particularly 5% by weight.
-20% by weight is preferred. If the amount is less than this, the cross-linking effect is small and the printing durability becomes insufficient. Specific examples of such a compound include those similar to the specific examples of the compound having a thermoreactive group contained in the microcapsules.

A dye having a large absorption in the visible light region can be used as a colorant for an image. Specifically, Oil Yellow # 101, Oil Yellow # 10
3. Oil pink # 312, oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-50
5 (from Orient Chemical Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI4255)
5), methyl violet (CI42535), ethyl violet, rhodamine B (CI145170B),
Malachite green (CI42000), methylene blue (CI52015), etc., and JP-A-62-29324
No. 7 can be mentioned. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can be suitably used.

It is preferable to add these coloring agents since the image area and the non-image area can be easily distinguished after image formation. The addition amount is based on the total solid content of the heat-sensitive layer coating solution.
The ratio is 0.01 to 10% by weight.

In the present invention, a small amount of thermal polymerization inhibitor is used to prevent unnecessary thermal polymerization of a compound having an ethylenically unsaturated double bond which can be radically polymerized during preparation or storage of the coating solution for the thermosensitive layer. It is desirable to add an agent. Hydroquinone, as a suitable thermal polymerization inhibitor,
p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4 -Methyl-6-t-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% to about 5% by weight based on the weight of the whole composition. Further, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the heat-sensitive layer in a drying process after coating. . The amount of the higher fatty acid derivative to be added is about 0.1% of the total composition.
1% to about 10% by weight is preferred.

The heat-sensitive layer coating solution of the present invention contains a nonionic resin such as described in JP-A-62-251740 and JP-A-3-208514 in order to widen the stability of processing under development conditions. Surfactant, JP 59
An amphoteric surfactant as described in JP-A-121044 and JP-A-4-13149 can be added.
Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearic acid, and polyoxyethylene nonyl phenyl ether.

Specific examples of the amphoteric surfactant include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, and N-tetradecyl-N , N-betaine type (for example,
(Trade name: Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.). The proportion of the nonionic surfactant and the amphoteric surfactant in the coating solution for the heat-sensitive layer is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

Further, a plasticizer is added to the heat-sensitive layer coating solution according to the present invention, if necessary, to impart flexibility and the like to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.

In order to produce the lithographic printing plate precursor according to the present invention, the above-mentioned components necessary for the heat-sensitive layer coating solution are usually dissolved in a solvent and coated 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-butyllactone, toluene, water and the like, but are not limited thereto. Absent. 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.

The feeling on the support obtained after coating and drying
The coating amount (solid content) of the thermal layer varies depending on the application.
Generally speaking, 0.5 to 5.0 g of the printing plate precursor
/ M ^TwoIs preferred. Various methods for applying
Can be used, for example, a bar coater coating,
Spin coating, spray coating, curtain coating, dip coating
Cloth, air knife coating, blade coating, roll coating etc.
Can be mentioned. As the application amount decreases,
Sensitivity is high, but the function of image recording is high
The film properties of the layer are reduced.

The coating solution for the heat-sensitive layer according to the present invention may contain a surfactant for improving coating properties, for example, JP-A-62-17.
No. 0950 can be added. The preferred addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the solid content of the material of the entire thermosensitive layer.

[Overcoat Layer] In the lithographic printing plate precursor according to the present invention, a water-soluble overcoat layer is formed on the heat-sensitive layer in order to prevent contamination of the surface of the heat-sensitive layer by a lipophilic substance. The water-soluble overcoat layer used in the present invention can be easily removed at the time of printing and contains a resin selected from water-soluble organic polymer compounds. As the water-soluble organic polymer compound used here, a film formed by coating and drying has a film forming ability, and specifically,
Polyvinyl alcohol, polyvinyl acetate (having a hydrolysis rate of 65% or more), polyacrylic acid and its alkali metal salt or amine salt, polyacrylic acid copolymer and its alkali metal salt or amine salt, polymethacrylic acid and its Alkali metal salt or amine salt, polymethacrylic acid copolymer and its alkali metal salt or amine salt, polyacrylamide and its copolymer, polyhydroxyethyl acrylate, polyvinylpyrrolidone and its copolymer, polyvinyl methyl ether, polyvinyl methyl ether / Maleic anhydride copolymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid and its alkali metal salt or amine salt, poly-
2-acrylamide-2-methyl-1-propanesulfonic acid copolymer and its alkali metal salt or amine salt, gum arabic, cellulose derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof , White dextrin, pullulan, enzymatically degraded etherified dextrin and the like. Further, according to the purpose, two or more of these resins can be used in combination. Among these water-soluble resins, gum arabic is most preferred from the viewpoint of on-press developability.

[Fluorine atom-containing compound or silicon atom-containing compound] The water-soluble overcoat layer of the lithographic printing plate precursor according to the present invention contains a releasing agent for preventing sticking between the plates during stacking and storage. It is preferable to contain a fluorine atom-containing compound or a silicon atom-containing compound having the following formula. As the fluorine compound, a water-soluble or water-dispersible fluorine-based surfactant is used. Specifically, F
Substituted dodecanoic acid, F-substituted octanoic acid, F-substituted hexanoic acid, F-substituted butyric acid, ammonium salts of these carboxylic acids,
Examples include compounds having a perfluoroalkyl group and an ethyleneoxy group in the same molecule. As the silicon atom-containing compound, a water-soluble or water-dispersible silicone oil is used. Specific examples include polyether-modified silicone oil. The proportion of these compounds in the total solid content of the overcoat layer is 0.05 to 5.
It is preferably 0% by weight, more preferably 0.1% to 3% by weight. If it is less than 0.05%, it tends to stick when lithographic printing plate precursors are stacked, and scratches and scratches easily occur when the plate is rubbed with a piece of aluminum.
If the content is more than 5% by weight, the developability of the overcoat layer will deteriorate and the waste paper will increase.

The overcoat layer preferably contains a water-soluble photothermal conversion agent described below. Furthermore, in the case of aqueous solution application, a nonionic surfactant such as polyoxyethylene nonylphenyl ether and polyoxyethylene dodecyl ether can be added to the overcoat layer in order to ensure uniformity of application. . Dry coating amount of the overcoat layer, 0.1 to 2.0 g / m ² is preferred. If it is less than that, fingerprints will be stained,
If it is more than that, the on-press developability deteriorates.

[Light-to-heat conversion material] The lithographic printing plate precursor of the present invention contains a light-to-heat conversion material in the heat-sensitive layer or in a layer adjacent thereto, more preferably in the overcoat layer. Image writing can be performed by laser light irradiation or the like. The light-to-heat conversion material is not particularly limited as long as it absorbs the wavelength of the light source, such as carbon black / metal fine particles and dye, but a compound that absorbs infrared rays and converts it into heat is particularly preferable.

The photothermal conversion material is particularly preferably a substance that absorbs light of 700 nm or more, and various pigments and dyes can be used. Examples of pigments include commercially available pigments and color index (CI) handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977), “Latest Pigment Application Technology”
(CMC Publishing, 1986), "Printing ink technology" C
MC Publishing, 1984) can be used.

Examples of the kind of the pigment include a black pigment, a brown pigment, a red pigment, a violet pigment, a blue pigment, a green pigment, a fluorescent pigment, a metal powder pigment, and a polymer-bound pigment. 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 surface treatment, or may be used after surface treatment. Examples of the surface treatment include a method of surface-coating a hydrophilic resin or a lipophilic resin, a method of attaching a surfactant, and a reactive substance (eg, silica sol, alumina sol, a silane coupling agent, an epoxy compound, an isocyanate compound, etc.). A method of bonding to the surface of the pigment is conceivable. 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).
Among these pigments, 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 absorbing infrared light or near infrared light, carbon black, carbon black coated with a hydrophilic resin, and carbon black modified with silica sol are preferably used. Among these, carbon black whose surface is coated with a hydrophilic resin or silica sol is useful as a material that is easily dispersed in a water-soluble resin and does not impair hydrophilicity.

The particle size of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner 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).

As the dye, commercially available dyes and known dyes described in literatures (for example, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, published in 1970) 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. Among these 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.

Dyes which absorb infrared light or near infrared light include, for example, JP-A-58-125246 and JP-A-59-125246.
No. 84356, JP-A-60-78787, U.S. Pat. No. 4,973,572, JP-A-10-26851
No. 2, etc .;
73696, JP-A-58-181690, JP-A-5-181
Methine dyes described in JP-A-8-194595, JP-A-58-112793, JP-A-58-224793.
JP-A-59-48187, JP-A-59-7399
No. 6, JP-A-60-52940, JP-A-60-637
No. 44, etc .;
Squarylium dyes described in JP-A-8-112792, cyanine dyes described in British Patent 434,875, dyes described in U.S. Pat. No. 4,756,993, and U.S. Pat. No. 4,973,572. And the dyes described in JP-A-10-268512.

[0061]

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(Wherein R¹, R^Two, R^Three, R^Four, R^FiveAnd R⁶
Is a substituted or unsubstituted alkyl group; Z ¹And Z^TwoAlso replace
Or unsubstituted phenyl or naphthalene group; L is substituted
Or an unsubstituted methine group, wherein the substituent has 8 or less carbon atoms
An alkyl group, a halogen atom or an amino group,
The tin group is a substituent on the two methine carbons bonded to each other
Cyclohexene optionally having substituents formed by
Or a ring containing a cyclopentene ring
And the substituent is an alkyl group having 6 or less carbon atoms or halogen.
X is an anionic group; n is 1 or 2;¹,
R^Two, R^Three, R^Four, R^Five, R⁶, Z¹And Z^TwoAt least one of
One is an acidic group or an alkali metal base or an amine salt of an acidic group
It shows a substituent having a group. )

[0063]

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(Wherein R¹¹Is a substituted or unsubstituted al
Killed, substituted or unsubstituted aryl or substituted
Or an unsubstituted heterocyclic group; R¹²And R^FifteenIs a hydrogen atom or
A group which can be substituted in place of a hydrogen atom: R¹³And R¹⁴Is hydrogen field
Atom, halogen atom, substituted or unsubstituted alkoxy group
Or a substituted or unsubstituted alkyl group, provided that R¹³And R
¹⁴Are not simultaneously hydrogen atoms: R¹⁶And R¹⁷Is a replacement
Or unsubstituted alkyl group, substituted or unsubstituted aryl
Group, acyl group or sulfonyl group, or R¹⁶And R ¹⁷In non
The formation of a 5- or 6-membered metal ring is shown. )

As a dye, US Pat. No. 5,156,
No. 938 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 and pyrylium compounds described in JP-A-59-2161.
No. 46, a cyanine dye disclosed in U.S. Pat. No. 4,283,4.
No. 75, pentamethine thiopyrylium salt and the like, and pyrilium compounds disclosed in Japanese Patent Publication Nos. 5-135514 and 5-19702, Epolig manufactured by Eporin Co.
ht III-178, Epollight III-130,
Epollight III-125 and the like are particularly preferably used. Particularly preferred among these dyes are the water-soluble cyanine dyes of the above formula (I). Specific compounds are listed below.

[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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Next, the light-heat converting metal fine particles will be described. Many of the metal particles are photothermal and self-heating. Preferred metal fine particles include Si, A
1, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Y, Zr, Mo, Ag, Au, Pt, Pd, R
Simple particles or alloys of h, In, Sn, W, Te, Pb, Ge, Re, and Sb, or fine particles of oxides and sulfides thereof. Among the metals constituting these fine metal particles, preferred metals are those which have a melting point of about 1000 ° C. or less and easily absorb in the infrared, visible or ultraviolet regions, such as Re, Sb, Te, and Au. , A
g, Cu, Ge, Pb and Sn. Particularly preferred are metal fine particles having a relatively low melting point and a relatively high absorbance to heat rays, such as Ag, Au, Cu, and the like.
Among Sb, Ge and Pb, particularly preferred elements are Ag, A
u and Cu.

Further, for example, Re, Sb, Te, Au, A
g, Cu, Ge, Pb, Sn and other low melting point metal particles and self-heating metal particles such as Ti, Cr, Fe, Co, Ni, W, Ge, etc. It may be composed of a substance. Ag, P
It is preferable to use a combination of a metal-type micro-piece and a metal-type micro-piece, which have a particularly large light absorption when used as a micro-piece such as t or Pd. The effects of the present invention are more exerted by subjecting the surfaces of the above-described metal simple substance and alloy fine particles to hydrophilic treatment. Means of surface hydrophilicity is a compound that is hydrophilic and has an adsorptivity to particles, such as a surface treatment with a surfactant, or a surface treatment with a substance having a hydrophilic group that reacts with the constituent substances of the particles, A method such as providing a protective colloid hydrophilic polymer film can be used. Particularly preferred is a surface silicate treatment. For example, in the case of iron fine particles, sodium silicate (3
%) The surface can be made sufficiently hydrophilic by immersing it in an aqueous solution for 30 seconds. Other metal fine particles can be subjected to surface silicate treatment in the same manner.

The particle size of these particles is 10 μm or less, preferably 0.003 to 5 μm, and more preferably
0.01 to 3 μm. The finer the particle size, the lower the heat-sealing temperature, that is, the higher the light sensitivity in the heat mode, which is advantageous. In the present invention, when these light-to-heat conversion materials are used, the amount of addition is 1% by weight or more, preferably 2% by weight or more, particularly preferably 5% by weight, based on the total solid content of the heat-sensitive layer or overcoat layer. Used above. 1% by weight of light-to-heat conversion material
If it is less than this, the sensitivity is lowered.

[Support] In the lithographic printing plate precursor of the present invention, the hydrophilic support to which the heat-sensitive layer can be applied is a dimensionally stable plate-like material such as paper or plastic (for example, Paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate) on which polyethylene, polypropylene, polystyrene, etc. are laminated;
Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or vapor-deposited. Preferred supports include a polyester film or an aluminum plate.

As the support used in the lithographic printing plate precursor of the present invention, it is preferable to use an aluminum plate which is lightweight and has excellent surface treatment properties, workability and corrosion resistance. Aluminum materials used for this purpose include JIS 105
0 material, JIS 1100 material, JIS 1070 material, Al
-Mg-based alloy, Al-Mn-based alloy, Al-Mn-Mg-based alloy, Al-Zr-based alloy, Al-Mg-Si-based alloy and the like.

Known techniques relating to aluminum materials that can be used for the support are listed below. (1) For JIS 1050 material, the following technology is disclosed. JP-A-59-153861;
1-51395, JP-A-62-146694, JP-A-6-146694
0-215725, JP-A-60-215726, JP-A-60-215727, JP-A-60-215728, JP-A-61-272357, JP-A-58-11759, JP-A-58-42493, JP-A-58 -212254, JP-A-62-148295, JP-A-4-254545, JP-A-4-165541, JP-B-3-68939, JP-A-3-31989
234594, Tokkyo 1-47545, JP-A-62-2
No. 140894. In addition, Tokuhei 1-3591
0, Japanese Patent Publication No. 55-28874 and the like are also known.

(2) With respect to JIS 1070 material, the following technology is disclosed. JP-A-7-81264, JP-A-7-305133, JP-A-8-49034, JP-A-8-73974, JP-A-8-108657, JP-A-8-108
92679 and the like.

(3) With respect to Al-Mg based alloys, the following techniques are disclosed. JP-B-62-5080, JP-B-63-60823, JP-B-3-61753, JP-A-6
0-203496, JP-A-60-203497, JP-B-3-11635, JP-A-61-274993, JP-A-62-14973.
2-32794, JP-A-63-47347, JP-A-63-63
-47348, JP-A-63-47349, JP-A-64-
61293, JP-A-63-135294, JP-A-63-135
87288, JP 4-73392, JP 7-100
844, JP-A-62-149856, JP-B-4-733
94, JP-A-62-181191, Japanese Patent Publication No. 5-7653
0, JP-A-63-30294 and JP-B-6-37116. Further, JP-A-2-215599, JP-A-61-2
No. 01747 is also known.

(4) With respect to Al-Mn alloys, the following techniques are disclosed. JP-A-60-230951,
JP-A-1-306288 and JP-A-2-293189. In addition, Japanese Patent Publication 54-42284, Japanese Patent Publication 4-192
90, Japanese Patent Publication 4-19291, Japanese Patent Publication 4-19292,
JP-A-61-35995, JP-A-64-51992, U
S5009722, US5028276, JP-A-4-24-2
26394 and the like are also known. (5) With respect to Al-Mn-Mg based alloys, the following technology is disclosed. JP-A-62-86143, JP-A-Hei 3
-22,796, JP-B-63-60824, JP-A-Showa 60
-63346, JP-A-60-63347, EP2237
37, JP-A-1-283350, US4818300,
BR1222777 and the like are known.

(6) The following techniques are known for Al-Zr alloys. JP-B-63-15978, JP-A-61-51395, JP-A-63-143234, JP-A-63-143235 and the like are known. (7) For the Al-Mg-Si alloy, BR142
1710 and the like are known.

The following contents can be used as a method for producing an aluminum plate for a support. The aluminum alloy melt having the above-mentioned content components and alloy component ratios is subjected to a cleaning treatment and cast according to a conventional method. For the cleaning process,
In order to remove unnecessary gases such as hydrogen in the molten metal, flux treatment, degassing treatment using Ar gas, Cl gas, etc., so-called rigid media filters such as ceramic tube filters and ceramic foam filters,
Filtering using a filter material such as alumina flakes or alumina balls, filtering using a glass cloth filter or the like, or processing combining degassing and filtering is performed. These cleaning processes are performed in the molten metal.
It is desirable that the method be implemented in order to prevent defects due to foreign matter such as nonmetallic inclusions and oxides and defects due to gas dissolved in the molten metal.

With respect to the filtering of molten metal, JP-A-6-57342, JP-A-3-162530, and JP-A-5-
140659, JP-A-4-231425, JP-A-4-2
76031, JP-A-5-311261, JP-A-6-13
6466 and the like are known. Regarding degassing of molten metal,
JP-A-5-51659, JP-A-5-51660, JP-A-5-49148, and JP-A-7-40017 are known. As described above, casting is performed using the molten metal subjected to the cleaning treatment. Regarding the casting method, there are a method using a fixed mold typified by a DC casting method and a method using a driving mold typified by a continuous casting method. When the DC casting method is used, the solidification is performed at a cooling rate of 1 to 300 ° C./sec. When the temperature is less than 1 ° C./sec, a large number of coarse intermetallic compounds are formed.

The continuous casting method includes a method using a cooling roll, represented by the Hunter method and the 3C method, a Hadley method, a method using a cooling belt represented by the Al Swiss Caster II type, and a method using a cooling block. It is being done. The cooling rate when using the continuous casting method is 100 to 1000 ° C. /
Coagulated in seconds. Generally, since the cooling rate is higher than that of the DC casting method, there is a feature that the solid solubility of the alloy component in the aluminum matrix can be increased. Regarding the continuous casting method, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 3-7 / 1990.
9798, JP-A-5-201166, JP-A-5-156
414, JP-A-6-262203, JP-A-6-1229
49, JP-A-6-210406, JP-A-6-26230
8 etc. are disclosed.

When DC casting is performed, the thickness is 300 to 80.
A 0 mm ingot can be manufactured. The ingot, according to the usual method,
Facing is performed and the surface layer is 1 to 30 mm, preferably 1 to 30 mm.
10 mm is cut. Thereafter, a soaking process is performed as necessary. In the case of performing the soaking treatment, 1 to 450 ° C. to 620 ° C. is used to prevent the intermetallic compound from becoming coarse.
The heat treatment is performed for at least 48 hours. When the time is shorter than 1 hour, the effect of the soaking treatment becomes insufficient. Next, hot rolling and cold rolling are performed to obtain a rolled aluminum plate. The starting temperature of hot rolling is 350 to 500
It is in the range of ° C. Intermediate annealing treatment may be performed before, after, or during the cold rolling. The intermediate annealing conditions in this case are set to 280 ° C. to 6 ° C. using a batch annealing furnace.
00 ° C for 2 to 20 hours, desirably 350 to 500 ° C
Heating for 2 to 10 hours or using a continuous annealing furnace for 4 hours.
360 seconds or less at 00 to 600 ° C., desirably 450 to
Heat treatment at 550 ° C. for 120 seconds or less can be employed. Heating at a rate of 10 ° C./sec or higher using a continuous annealing furnace can also make the crystal structure fine.

By the above steps, a predetermined thickness of 0.1 to 0.1
The flatness of the Al plate finished to 0.5 mm may be improved by a straightening device such as a roller leveler or a tension leveler in order to improve the flatness. The flatness may be improved after the plate is cut into a sheet, but it is desirable to improve the flatness in a continuous coil state in order to improve productivity. Further, in order to process the board width to a predetermined width, a slitter line is usually passed. The end face of the plate cut by the slitter has one or both of a shear surface and a fracture surface when cut by a slitter blade.

The accuracy of the thickness of the plate is preferably within ± 10 μm, preferably within ± 6 μm over the entire length of the coil.
The thickness difference in the width direction is within 6 μm, preferably 3 μm.
Within is good. Also, the accuracy of the board width is within ± 1.0mm,
Preferably, it is within ± 0.5 mm. The surface roughness of the Al plate is easily affected by the surface roughness of the rolling roll,
Finally, the center line surface roughness (Ra) is Ra = 0.1 to
It is preferable to finish to about 1.0 μm. If Ra is too large, the original roughness of Al, that is, the rough rolling streaks transferred by the rolling rolls can be seen from above the heat-sensitive layer when the surface-roughening treatment for a lithographic printing plate and the heat-sensitive layer are applied. Is not preferable in appearance. Roughness of Ra = 0.1 μm or less is industrially undesirable because the surface of the rolling roll needs to be finished to an excessively low roughness.

Further, a thin oil film may be formed on the surface of the Al plate in order to prevent generation of scratches due to friction between the Al plates. Oil slicks may be volatile,
A non-volatile one is appropriately used. If there is too much oil,
A slip failure occurs in the production line, but if there is no oil amount, a defect occurs during transportation of the coil. Therefore, the oil amount is 3 mg / m ² or more and 100 mg / m ² or less, and a desirable upper limit is 50 mg / m ^2. m ² or less, more preferably 10
mg / m ² or less is good. Regarding cold rolling,
No. -210308 is disclosed.

In the case of performing continuous casting, for example, using a cooling roll such as a Hunter method can directly and continuously cast and roll a cast plate having a thickness of 1 to 10 mm, and has an advantage that the hot rolling step can be omitted. In addition, when a cooling roll such as the Hasley method is used, a cast plate having a plate thickness of 10 to 50 mm can be cast,
In general, a hot-rolled roll is arranged immediately after casting and continuously rolled to obtain a continuously cast rolled plate having a thickness of 1 to 10 mm. These continuous cast rolled sheets are finished to a thickness of 0.1 to 0.5 mm through the steps of cold rolling, intermediate annealing, improvement of flatness, slits, etc., as described in the case of DC casting. Can be Regarding the intermediate annealing condition and the cold rolling condition when the continuous casting method is used, refer to JP-A-6-2205.
93, JP-A-6-210308, JP-A-7-5541
1, JP-A-8-92709 and the like are disclosed.

The Al plate produced by the above method can be subjected to a surface treatment such as a surface roughening treatment, and a heat-sensitive layer can be applied to obtain a lithographic printing plate precursor. In the surface roughening treatment, mechanical surface roughening, chemical surface roughening, and electrochemical surface roughening are performed alone or in combination. Further, it is also preferable to perform an anodic oxidation treatment for securing the surface with difficulty in scratching or a treatment for increasing the hydrophilicity.

The surface treatment of the support will be described below. Prior to roughening the aluminum plate, if necessary, for example, a surfactant to remove rolling oil on the surface,
A degreasing treatment with an organic solvent or an alkaline aqueous solution may be performed. In the case of alkali, treatment such as neutralization and removal of smut may be performed with an acidic solution.

Next, in order to improve the adhesion between the support and the heat-sensitive layer and to impart water retention to the non-image area, a so-called graining treatment is performed to roughen the surface of the support. Specific means of the graining method include sand blast, ball grain, wire grain, brush grain using a nylon brush and an abrasive / water slurry,
There is a mechanical graining method using a honing grain or the like in which an abrasive / water slurry is sprayed onto the surface at a high pressure, and a chemical graining method in which the surface is roughened with an etching agent composed of an alkali, an acid, or a mixture thereof. . In addition, British Patent No. 896,563,
JP-A-3-67507, JP-A-54-146234 and JP-B-48-28123 describe the method of electrochemical graining, or JP-A-53-1232.
No. 04, JP-A-54-63902 and a combination of the mechanical graining method and the electrochemical graining method described in JP-A-56-55261. A method is also known in which a graining method is combined with a chemical graining method using a saturated aqueous solution of an aluminum salt of a mineral acid. Also, a method of bonding the granular material to the support material with an adhesive or a method having the effect thereof to roughen the surface, or a continuous band or roll having fine unevenness is pressed against the support material to remove the unevenness. A rough surface may be formed by transferring.

A plurality of such surface roughening methods may be performed in combination, and the order, the number of repetitions, and the like can be arbitrarily selected. When a plurality of surface roughening treatments are combined, a chemical treatment with an acid or alkali aqueous solution can be performed during that time to make the subsequent surface roughening treatment uniform. Specific examples of the above-mentioned acid or alkali aqueous solution include, for example, acids such as hydrofluoric acid, fluorinated zirconic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid, and alkali aqueous solutions such as sodium hydroxide, sodium silicate, and sodium carbonate. . These acid or alkali aqueous solutions can be used alone or in combination of two or more. The chemical treatment uses a 0.05 to 40% by weight aqueous solution of these acids or alkalis,
In general, the treatment is performed at a liquid temperature of 00 ° C. for 5 to 300 seconds.

Since a smut is formed on the surface of the support obtained by the above-described roughening treatment, ie, graining treatment, a treatment such as washing with water or alkali etching is appropriately performed to remove the smut. Is generally preferred. Examples of such processing include, for example,
Examples thereof include a treatment method such as an alkali etching method described in JP-A-8-28123 and a desmutting sulfate method described in JP-A-53-12739. In the case of the aluminum support used in the present invention, after performing the pretreatment as described above, usually, in order to improve abrasion resistance, chemical resistance, and water retention, an oxide film is formed on the support by anodic oxidation. Is formed.

As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte can be used as long as it forms a porous oxide film.
Phosphoric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. Since the treatment conditions of anodization vary depending on the electrolyte used, it cannot be specified unconditionally, but generally, the concentration of the electrolyte is a 1 to 80% solution, the liquid temperature is 5 to 70 ° C.,
It is appropriate that the current density is 5 to 60 A / dm ² , the voltage is 1 to 100 V, and the electrolysis time is 10 seconds to 5 minutes. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image area of the lithographic printing plate is easily damaged, and the ink adheres to the damaged area during printing. "Scratch dirt" is likely to occur.

[0099] Although such anodizing treatment is performed on a surface used for printing of the support of the lithographic printing plate, the back around the electric lines of force, on the back surface of 0.01 to 3 g / m ² anode Generally, an oxide film is formed. Further, an anodic oxidation treatment in an alkaline aqueous solution (for example, a caustic soda aqueous solution of several%) or a molten salt, or an anodic oxidation treatment for forming a non-porous anodic oxide film using, for example, an ammonium borate aqueous solution can be performed. . Before performing anodizing treatment,
A hydrated oxide film described in JP-A-148991 or JP-A-4-97896 may be formed. An acid salt solution, a hydrated oxide film forming treatment, a chemical conversion film forming treatment described in JP-A-56-144195, and the like can also be performed.

The aluminum support used in the lithographic printing plate precursor according to the present invention can be treated with an organic acid or a salt thereof after anodizing treatment, or the organic acid or a salt thereof can be used as an undercoat layer applied to a heat-sensitive layer. . Examples of the organic acid or a salt thereof include an organic carboxylic acid, an organic phosphonic acid, an organic sulfonic acid or a salt thereof, and preferably an organic carboxylic acid or a salt thereof. Examples of the organic carboxylic acids include aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, lauric acid, palmitic acid and stearic acid; unsaturated aliphatic monocarboxylic acids such as oleic acid and linoleic acid; oxalic acid, succinic acid Aliphatic dicarboxylic acids such as acid, adipic acid, and maleic acid; oxycarboxylic acids such as lactic acid, gluconic acid, malic acid, tartaric acid, and citric acid; aromatic carboxylic acids such as benzoic acid, mandelic acid, salicylic acid, and phthalic acid; , IIb, IIIb, IVa, VI
Group b and VIII metal salts and ammonium salts. Preferred among the organic carboxylate salts are formic acid,
Acetic acid, butyric acid, propionic acid, lauric acid, oleic acid,
The above-mentioned metal salts and ammonium salts of succinic acid and benzoic acid. These compounds may be used alone or in combination of two or more.

These compounds are used in water and alcohol in 0.0
It is preferably dissolved in a concentration of from 0.01 to 10% by weight, particularly from 0.01 to 1.0% by weight. The processing conditions include a temperature range of 25 to 95 ° C, preferably 50 to 95 ° C.
H is 1 to 13, preferably 2 to 10 minutes, 10 seconds to 20
The support is immersed in the support for 10 minutes, preferably 10 seconds to 3 minutes, or the treatment liquid is applied to the support.

Further, after the anodic oxidation treatment, treatment with the following compound solution or these compounds can be used as an undercoat layer applied to the heat-sensitive layer. Suitable compounds include, for example, optionally substituted phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, organic phosphonic acids such as methylenediphosphonic acid and ethylenediphosphonic acid, substituted Phenyl phosphate, naphthyl phosphate, which may have a group,
Organic phosphoric acids such as alkyl phosphoric acid and glycerophosphoric acid, organic phosphinic acids such as optionally substituted phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid, glycine, β
-Amino acids such as alanine, valine, serine, threonine, aspartic acid, glutamic acid, arginine, lysine, tryptophan, parahydroxyphenylglycine, dihydroxyethylglycine, and anthranilic acid; aminosulfonic acids such as sulfamic acid and cyclohexylsulfamic acid; 1-amino acid Methylphosphonic acid, 1-dimethylaminoethylphosphonic acid, 2-aminoethylphosphonic acid, 2-aminopropylphosphonic acid, 4-aminophenylphosphonic acid, 1-aminoethane-1,1-diphosphonic acid, 1-amino-1-phenyl Aminophosphonic acids such as methane-1,1-diphosphonic acid, 1-dimethylaminoethane-1,1-diphosphonic acid, 1-dimethylaminobutane-1,1-diphosphonic acid, and ethylenediaminetetramethylenephosphonic acid; Compounds, and the like.

Further, hydrochloric acid, sulfuric acid, nitric acid, sulfonic acid (such as methanesulfonic acid) or oxalic acid, an alkali metal,
Salts with ammonia, lower alkanolamines (such as triethanolamine), lower alkylamines (such as triethylamine) and the like can also be suitably used.

Polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine and its mineral salts, poly (meth) acrylic acid and its metal salts, polystyrenesulfonic acid and its metal salts, alkyl (meth) acrylate and 2-acrylamide Water-soluble polymers such as 2-methyl-1-propanesulfonic acid and metal salts thereof, polymers of trialkylammonium methylstyrene styrene and copolymers thereof with (meth) acrylic acid, and polyvinylphosphonic acid can also be suitably used. it can. Further, soluble starch, carboxymethylcellulose, dextrin, hydroxyethylcellulose, gum arabic, guar gum, sodium alginate, gelatin, glucose, sorbitol and the like can also be suitably used. These compounds may be used alone or in combination of two or more.

In the case of treatment, these compounds are preferably dissolved in water and / or methyl alcohol at a concentration of 0.001 to 10% by weight, particularly 0.01 to 1.0% by weight. The temperature is in the range of 25 to 95 ° C., preferably 50 to 95 ° C., and the pH is 1 to 13, preferably 2 to 10, 10 seconds to 20 minutes, and preferably 10 seconds to 3 minutes.

When used as an undercoat layer for coating the heat-sensitive layer, water and / or methyl alcohol are similarly used.
It is dissolved so as to have a concentration of 1 to 10% by weight, particularly 0.01 to 1.0% by weight, and if necessary, a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, hydrochloric acid, phosphoric acid or the like. Adjust the pH with an acidic substance,
It can also be used in the range of ~ 12. Further, a yellow dye can be added for improving the tone reproducibility of the lithographic printing plate precursor. The coating amount of the organic undercoat layer after drying is 2 to
200 mg / m ² is suitable, preferably 5 to 100 mg / m ^2.
mg / m ² . If the above-mentioned coating amount is less than 2 mg / m ² , a sufficient effect for the original purpose such as prevention of stain cannot be obtained. On the other hand, if it exceeds 200 mg / m ² , the printing durability will decrease.

An intermediate layer for improving the adhesion between the support and the heat-sensitive layer may be provided. To improve adhesion,
Generally, the intermediate layer is made of a diazo resin or a phosphoric acid compound adsorbed on aluminum, for example. The thickness of the intermediate layer is arbitrary and must be such a thickness that a uniform bond-forming reaction with the upper thermosensitive layer can be performed when exposed. Normal,
The dry solid has a good coating ratio of about 1 to 100 mg / m ² ,
5-40 mg / m ² are particularly good. The usage ratio of the diazo resin in the intermediate layer is 30 to 100%, preferably 60 to 100%.

Before the above treatment and the application of the undercoat layer, the support subjected to the anodic oxidation treatment is washed with water, and then the dissolution of the anodic oxide film in a developing solution or dampening solution is suppressed, and the components of the heat-sensitive layer are removed. The following treatments can be performed for the purpose of suppressing residual film, improving the strength of the anodic oxide film, improving the hydrophilicity of the anodic oxide film, improving the adhesion to the heat-sensitive layer, and the like. One of them is a silicate treatment in which an anodized film is brought into contact with an aqueous solution of an alkali metal silicate for treatment. In this case, the concentration of the alkali metal silicate is 0.1 to 30% by weight, preferably 0.5 to 15% by weight, and the pH at 25 ° C is 10 to 13.5. , Preferably 10 to 70 ° C, more preferably 15 to 50 ° C for 0.5 to 120 seconds. The contacting method may be any method such as dipping or spraying. The alkali metal silicate aqueous solution is p
When H is lower than 10, the liquid gels, and when H is higher than 13.5, the anodic oxide film is dissolved.

The alkali metal silicate used in the present invention includes sodium silicate, potassium silicate, lithium silicate and the like. P of aqueous alkali metal silicate solution
Hydroxides used for H adjustment include sodium hydroxide, potassium hydroxide, lithium hydroxide and the like. The above-mentioned processing solution contains an alkaline earth metal salt or IVb.
A group metal salt may be blended. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate and borate. Is mentioned. Examples of Group IVb metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, and the like. The alkaline earth metal or Group IVb metal salt can be used alone or in combination of two or more. The preferred range of these metal salts is 0.01 to 10% by weight, and more preferably 0.05 to 5.0% by weight.

In addition, various sealing treatments can also be mentioned. Steam sealing, boiling water (hot water) sealing, and metal salt sealing (generally known as methods for sealing an anodic oxide film) are also available. Chromate / dichromate seal, nickel acetate seal, etc.), oil impregnated seal, synthetic resin seal, low temperature seal (by red blood salt or alkaline earth salt, etc.) can be used. , Performance as a support for a printing plate (adhesion with a heat-sensitive layer and hydrophilicity),
From the viewpoints of high-speed processing, low cost, and low pollution, steam sealing is relatively preferred. As the method, for example,
No. 176690 discloses a method for continuously or discontinuously applying pressurized or normal pressure steam to a anodic oxide film at a relative humidity of 70% or more and a steam temperature of 95 ° C. or more for about 2 to 180 seconds. And the like. As another sealing treatment method, a method of immersing or spraying the support in hot water or an aqueous alkali solution at about 80 to 100 ° C.,
Alternatively or subsequently, it can be dipped or sprayed with a nitrous acid solution. Examples of nitrites include Ia, IIa, IIb, IIIb, IVb, IVa, VIa of the periodic table.
a, VIIa, and VIII metal nitrites or ammonium salts, ie, ammonium nitrite, such as LiO ₂ , NaNO ₂ , KNO ₂ , M
g (NO ₂ ) ₂ , Ca (NO ₂ ) ₂ , Zn (NO ₃ ) ₂ , Al
(NO ₂ ) ₃ , Zr (NO ₂ ) ₄ , Sn (NO ₂ ) ₃ , Cr
(NO ₂ ) ₃ , Co (NO ₂ ) ₂ , Mn (NO ₂ ) ₂ , Ni
(NO ₂ ) _{2 and the} like are preferable, and alkali metal nitrite is particularly preferable. Two or more nitrites can be used in combination.

The processing conditions vary depending on the state of the support and the type of alkali metal, and cannot be uniquely determined.
For example, when sodium nitrite is used, the concentration is generally 0.001 to 10% by weight, more preferably 0.01 to 10% by weight.
1-2% by weight, bath temperature generally from room temperature to about 100 ° C
Before and after, more preferably at 60 to 90 ° C., and the treatment time may be generally selected from the respective ranges of 15 to 300 seconds, more preferably 10 to 180 seconds. Nitrous acid aqueous solution
H is preferably adjusted to 8.0 to 11.0, and particularly preferably adjusted to 8.5 to 9.5. To adjust the pH of the nitrous acid aqueous solution to the above range,
For example, it can be suitably prepared using an alkaline buffer or the like. Examples of the alkaline buffer include, but are not limited to, a mixed aqueous solution of sodium hydrogen carbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium hydroxide, a mixed aqueous solution of sodium carbonate and sodium hydrogen carbonate, and a mixed aqueous solution of sodium chloride and sodium hydroxide. Mixed aqueous solution,
A mixed aqueous solution of hydrochloric acid and sodium carbonate, a mixed aqueous solution of sodium tetraborate and sodium hydroxide, and the like can be suitably used. Further, as the alkaline buffer, an alkali metal salt other than sodium, for example, a potassium salt can be used.

After the silicate treatment or the sealing treatment as described above, the acidic aqueous solution treatment and the hydrophilic undercoat disclosed in JP-A-5-278362 are applied to improve the adhesion to the heat-sensitive layer. And Japanese Patent Application Laid-Open
An organic layer disclosed in JP-A-282637 or JP-A-7-314937 may be provided.

After the above-mentioned treatment or undercoating is applied to the surface of the support, a back coat is provided on the back surface of the support, if necessary. As such a back coat, a coating layer comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 is used. It is preferably used. Among these coating layers, Si (OCH ₃ ) ₄ , Si (OC
_{2 H 5) 4, Si (} OC 3 H 7) 4, Si (OC 4 H 9) is easily available and inexpensive alkoxy compounds of silicon such as _4, the coating layer of the obtained therefrom metal oxide in developing solution Excellent and particularly preferred.

The preferred characteristics of the lithographic printing plate support are 0.10 to 1.2 μm in center line average roughness. When the thickness is less than 0.10 μm, the adhesion to the heat-sensitive layer decreases,
Significant reduction in printing durability occurs. If it is larger than 1.2 μm, the stain on printing will be deteriorated. Further, the color density of the support is 0.15 to 0.5 as a reflection density value.
65, and when it is whiter than 0.15, the halation at the time of image exposure is too strong and hinders image formation.
If it is less than 0.65, the image is difficult to see in the plate inspection work after development, and the plate inspection is extremely poor.

In the lithographic printing plate precursor of the present invention, better on-press developability can be obtained by using, as a support, an aluminum substrate which has been subjected to a surface roughening treatment and then subjected to an anodic oxidation treatment. be able to. In that case, it is more preferable to use an aluminum substrate further subjected to a silicate treatment.

The printing plate is made of a hydrophilic layer insoluble in water on an aluminum substrate, a hydrophilic layer which generates heat by laser exposure and is insoluble in water, or an organic polymer for imparting heat insulation to the aluminum substrate. In addition to the heat insulating layer, a hydrophilic layer insoluble in water or a hydrophilic layer that generates heat by laser exposure and is insoluble in water may be provided. For example, a hydrophilic layer of silica fine particles and a hydrophilic resin may be provided on an aluminum substrate. Further, the above-mentioned photothermal conversion material may be introduced into the hydrophilic layer to form a heat-generating hydrophilic layer. This makes it difficult for heat to escape to the aluminum substrate, or it can be used as a hydrophilic substrate that generates heat by laser exposure. Further, when an intermediate layer made of an organic polymer is provided between the hydrophilic layer and the aluminum substrate, the escape of heat to the aluminum substrate can be further suppressed. The support is preferably non-porous from the viewpoint of on-press developability, and a support which swells with water containing 40% or more of a hydrophilic organic polymer material is difficult to be dispensed with ink. turn into.

The hydrophilic layer used in the present invention is three-dimensionally crosslinked, is a lithographic printing using water and / or ink, and is a layer that is insoluble in soaking water, and is preferably made of the following colloids. It is a colloid comprising a sol-gel conversion system of an oxide or hydroxide of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony or a transition metal. In some cases, a colloid composed of a complex of these elements may be used. These colloids have a structure in which the above elements form a network structure via an oxygen atom and also have an unbonded hydroxyl group or alkoxy group, and these are mixed. From the initial hydrolysis-condensation stage, which is rich in active alkoxy groups and hydroxyl groups, the particle size increases and becomes inactive as the reaction proceeds. Colloidal particles are generally 2 nm to 500 nm, and in the case of silica, spherical particles having a diameter of 5 nm to 100 nm are suitable in the present invention. 100 × 10n like aluminum colloid
A feather-like material such as m is also effective. Furthermore, 10n
A pearl neck-shaped colloid in which spherical particles of m to 50 nm are connected in a length of 50 to 400 nm can also be used.

The colloid may be used alone,
Furthermore, it is also possible to mix and use with a hydrophilic resin. Further, a colloidal crosslinking agent may be added to promote crosslinking. Usually, colloids are often stabilized by stabilizers. For a colloid charged with a cation, a compound having an anionic group is added as a stabilizer, and conversely, for a colloid charged with an anion, a compound having a cationic group is added as a stabilizer. For example, a silicon colloid is charged with an anion, so an amine compound is added as a stabilizer, and an aluminum colloid is charged with a cation, so a strong acid such as hydrochloric acid or acetic acid is added. When such a colloid is applied on a substrate, a transparent film is often formed at room temperature.However, gelation is incomplete only by evaporation of the colloid solvent, and by heating to a temperature at which the stabilizer can be removed, By performing strong tertiary cross-linking, it becomes a hydrophilic layer preferable in the present invention.

Without using the above-mentioned stabilizer, a hydrolysis and condensation reaction is directly carried out from a starting material (for example, di, tri and / or tetraalkoxy silane) to form an appropriate sol state and directly onto a substrate. The reaction may be completed by coating and drying. In this case, three-dimensional crosslinking can be performed at a lower temperature than when a stabilizer is included.

In addition, a colloid prepared by dispersing and stabilizing an appropriate hydrolysis-condensation reaction product in an organic solvent is also suitable for the present invention. Just by evaporating the solvent, a three-dimensionally crosslinked film is obtained. If these solvents are low boiling solvents such as methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and methyl ethyl ketone,
Drying at room temperature becomes possible. In particular, in the present invention, the colloid of a methanol or ethanol solvent is easily cured at a low temperature and is useful.

As the hydrophilic resin used together with the above colloid, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl and carboxymethyl are preferable. Specific hydrophilic resins include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and their Na salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids And salts thereof, polymethacrylic acids and salts thereof, hydroxyethyl methacrylate homopolymers and copolymers, hydroxyethyl acrylate homopolymers and copolymers, hydroxypropyl methacrylate homopolymers and copolymers,
Hydroxypropyl acrylate homopolymers and copolymers, hydroxybutyl methacrylate homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and a degree of hydrolysis of at least 60% by weight; Preferably at least 80% by weight of hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, homopolymers and copolymers of acrylamide, homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, 2-acrylamide- 2
And homopolymers and copolymers of methylpropanesulfonic acid or a salt thereof.

Particularly preferred hydrophilic resins are non-water soluble hydroxyl group-containing polymers, specifically, hydroxyethyl methacrylate homopolymers and copolymers and hydroxyethyl acrylate copolymers. These hydrophilic resins are used together with a colloid, and the addition ratio thereof is 40% of the total solid content of the hydrophilic layer when the hydrophilic resin is water-soluble.
% By weight or less, and in the case of a hydrophilic resin that is not water-soluble, preferably 20% by weight or less of the total solid content.

These hydrophilic resins can be used as they are, but a crosslinking agent for a hydrophilic resin other than colloid may be added for the purpose of increasing the printing durability during printing. Examples of such a crosslinking agent for a hydrophilic resin include initial hydrolysis and condensation products of formaldehyde, glyoxal, polyisocyanate and tetraalkoxysilane, dimethylol urea and hexamethylol melamine. In addition to the above-mentioned colloid of the oxide or hydroxide and the hydrophilic resin, a crosslinking agent which promotes the crosslinking of the colloid may be added to the hydrophilic layer of the present invention. As such a crosslinking agent, an initial hydrolysis condensate of tetraalkoxysilane, trialkoxysilylpropyl-N, N, N-trialkylammonium halide or aminopropyltrialkoxysilane is preferable. The addition ratio is 5% by weight of the total solids in the hydrophilic layer.
The following is preferred.

Further, a hydrophilic photothermal conversion material may be added to the hydrophilic layer of the present invention in order to enhance the heat sensitivity. A particularly preferred photothermal conversion material is a water-soluble infrared absorbing dye, and is a cyanine dye having a sulfonic acid group or an alkali metal base of sulfonic acid or an amine base of the formula (I). The addition ratio of these dyes is 1 to the total amount of the hydrophilic layer.
% To 20% by weight, more preferably 5% to 15% by weight.
% By weight.

The coating thickness of the three-dimensionally crosslinked hydrophilic layer of the present invention is preferably from 0.1 μm to 10 μm. More preferably, it is 0.5 μm to 5 μm. If it is too thin, the durability of the hydrophilic layer will be poor, and the printing durability during printing will be poor. On the other hand, if the thickness is too large, the resolution is reduced. Hereinafter, the intermediate layer made of an organic polymer will be described. Organic polymers that can be used for the intermediate layer include polyurethane resins, polyester resins, acrylic resins, cresol resins, resole resins,
Any commonly used organic polymer such as polyvinyl acetal resin and vinyl resin can be used without any problem. It is preferred that these are the coating weight of ^{0.1g / m 2 ~5.0g / m 2} . If it is 0.1 g / m ² or less, the heat insulating effect is small, and if it is more than 5.0 g / m ² , the printing durability of the non-image portion is deteriorated.

The lithographic printing plate precursor of the present invention can form an image by high-power laser exposure, but a writer such as a thermal head may be used. In particular, in the present invention, it is preferable to use a laser that emits light in the infrared or near-infrared region. In particular, a laser diode that emits light in the near infrared region is particularly preferable. Further, recording with an ultraviolet lamp is also possible, but in the present invention, the wavelength is 760 nm.
It is preferable to perform image exposure using a solid-state laser and a semiconductor laser that emit infrared rays of from 1200 to 1200 nm. The output of the laser is preferably 100 mW or more, and in order to shorten the exposure time, it is preferable to use a multi-beam laser device. Further, the exposure time per pixel is preferably within 20 μsec. The energy applied to the recording material is preferably from 10 to 300 mJ / cm ² .

The plate thus exposed is mounted without processing on a cylinder of a printing press.
The plate thus attached can be printed by the following procedure. (1) A method in which dampening water is supplied to the printing plate and development is performed on the machine, and then ink is further supplied to start printing. (2) A dampening solution and ink are supplied to the printing plate and developed on the machine. And (3) supplying ink to the plate and supplying dampening water, and at the same time supplying paper and starting printing. These plates are disclosed in Japanese Patent No. 2938398.
As described in the above item, after being mounted on the printing press cylinder, it is also possible to expose by a laser mounted on the printing press and then apply on-press development with dampening water and / or ink. Preferably, it can be developed with water or an aqueous solution, or can be directly mounted on a printing machine without being developed for printing.

[0128]

[Examples 1 to 6, Comparative Examples 1 to 3]

[Preparation of Support] (Preparation of Aluminum Substrate) An aluminum plate (material: JISA1050) having a thickness of 0.24 mm is grained with a nylon brush and a 400 mesh pumice water suspension, and thoroughly washed with water. did. The plate was immersed in a 15% by weight aqueous solution of sodium hydroxide for etching, and then washed with water. Further neutralize with 1% by weight nitric acid, then add 0.
Using a square wave alternating current in a 7% by weight nitric acid aqueous solution,
The electrolytic surface roughening treatment was carried out at an anode charge of 60 coulombs / dm ² . After washing with water, the film was immersed in a 10% by weight aqueous solution of sodium hydroxide for etching, and then washed with water. Next, it was immersed in a 30% by weight sulfuric acid aqueous solution to be desmutted and then washed with water.
Further, an anodic oxidation treatment was performed in a 20% by weight aqueous sulfuric acid solution using a direct current to adjust the oxide film amount to 3.0 g / m ^2, and then washed with water and dried.

[Formation of heat-sensitive layer] (Preparation of microcapsule (1) encapsulating a compound having a heat-reactive functional group) As oil phase components, 40 g of xylene diisocyanate, 10 g of trimethylolpropane diacrylate, allyl methacrylate and butyl methacrylate 10 g of a copolymer (molar ratio 7/3) of pionin A
0.1 g of 41C (manufactured by Takemoto Yushi) was dissolved in 60 g of ethyl acetate. As an aqueous phase component, 120 g of a 4% aqueous solution of PVA205 (manufactured by Kuraray) was prepared. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm using a homogenizer. Thereafter, 40 g of water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The microcapsule solution thus obtained had a solid content of 20% and an average particle size of 0.5 μm.

(Coating Solution of Thermosensitive Layer (1)) Prepared microcapsules (1) 5 g in terms of solid content Trimethylolpropane triacrylate 1 g 0.3 g of infrared absorbing water-soluble dye (I-32) described in this specification 0.3 g Water 60 g 40 g of 1-methoxy-2-propanol

The heat-sensitive layer was formed by using the above-mentioned heat-sensitive layer coating solution so as to have a dry coating amount of 1.0 g / m ² and dried (at 80 ° C. for 60 seconds in an oven).

[Formation of Overcoat Layer] Next, on the heat-sensitive layer (1), an overcoat layer coating solution (O
C-1, Example 1), (OC-2, Example 2), (OC
-3, Example 3), (OC-4, Example 4), (OC-
5, Example 5), (OC-6, Example 6), (OC-
7, Example 7), (OC-8, Comparative Example 1) was applied, and
After drying at 0 ° C. for 2 minutes, the dry coating weight is about 1.0 g / m ^2.
A lithographic printing plate precursor having an overcoat layer was prepared. In addition, a lithographic printing plate precursor without an overcoat layer was prepared, and Comparative Example 2 was used.

(Overcoat Layer Coating Solution OC-1) Arabic Gum 2.2 g Polyoxyethylene Nonylphenyl Ether 0.04 g Fluorosurfactant Surflon S-141 (manufactured by Kayasu Glass) 0.04 g Water 42 g

(Coating solution OC-2 for overcoat layer) Arabic gum 2.2 g Polyoxyethylene nonylphenyl ether 0.04 g Polyether-modified silicone oil X-22-812 (manufactured by Shin-Etsu Silicone) 0.04 g Water 42 g

(Overcoat Layer Coating Solution OC-3) Arabic gum 2.2 g Infrared absorbing water-soluble dye (I-32) described in this specification 0.4 g Fluorosurfactant Surflon S-141 (manufactured by Asahi Glass) 0 0.04 g Polyoxyethylene nonyl phenyl ether 0.04 g Water 42 g

(Overcoat Layer Coating Solution OC-4) Gum Arabic 2.2 g Infrared absorbing water-soluble dye (I-32) described in this specification 0.4 g Polyoxyethylene nonylphenyl ether 0.04 g Polyether-modified silicone oil X-22-812 (Shin-Etsu Silicone) 0.04 g Water 42 g

(Coating solution OC-5 for overcoat layer) Arabic gum 2.2 g Infrared absorbing water-soluble dye (I-32) described in this specification 0.4 g Polyoxyethylene nonylphenyl ether 0.04 g Polyether-modified silicone oil X-22-812 (made by Shin-Etsu Silicone) 0.002 g water 42 g

(Overcoat Layer Coating Solution OC-6) Polyacrylic acid 2.2 g Infrared absorbing water-soluble dye (I-32) described in this specification 0.4 g Polyoxyethylene nonylphenyl ether 0.04 g Polyether-modified silicone Oil X-22-812 (Shin-Etsu Silicone) 0.04 g Water 42 g

(Coating solution OC-7 for overcoat layer) Arabic gum 2.2 g Infrared absorbing water-soluble dye (I-32) described in this specification 0.4 g Polyoxyethylene nonylphenyl ether 0.04 g Polyether-modified silicone oil X-22-812 (made by Shin-Etsu Silicone) 0.18 g water 42 g

(Overcoat Layer Coating Solution OC-8) Arabic Gum 2.2 g Polyoxyethylene Nonylphenyl Ether 0.04 g Water 42 g

The lithographic printing plate precursor thus obtained was subjected to sensory evaluation on the degree of sticking of the front and back surfaces when 3000 sheets were stacked and stored at 35 ° C. and 75% temperature and humidity for 3 days. The coefficient of kinetic friction of the surface is, as described above, a standard A
It was measured by a measuring method according to STMD1894. This lithographic printing plate precursor was converted to a Creo Trendsetter 3244 VFS equipped with a water-cooled 40 W infrared semiconductor laser.
, Output 9 W, outer drum rotation speed 210 rpm, plate surface energy 150 mJ / cm ² , resolution 2400 dpi
After exposure under the conditions of the above, without processing, attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg Co., and after supplying fountain solution, immediately supply ink, and simultaneously supply paper to perform printing, At that time, the number of sheets until the non-surface image portion was not stained was examined (shown in Table 1 as the number of damaged sheets). The scratch and dirt generation rate was 10 pieces of aluminum plate for the lithographic printing plate precursor.
The occurrence rate of dirt when rubbing printing was performed at 0 places was examined.

[0142]

[Table 1]

As is clear from the results shown in Table 1, the lithographic printing plate precursors of Examples 1 to 7 of the present invention were prepared by adding an appropriate amount of a compound containing a fluorine atom or a silicon atom (release agent) to the overcoat layer. , The dynamic friction coefficient becomes a specified value (2.
5 or less), there is no sticking between the plates and no scratches and stains are generated. In particular, the lithographic printing plate precursors of Examples 1 to 6 have satisfactory results with a small number of waste sheets. 1 and 2 planographic printing plate precursors (dynamic friction coefficient is 2.5 or more)
Was an unsatisfactory result of sticking between the plates and fouling.

[Examples 7 to 12, Comparative Examples 4 to 6] (Method of preparing hydrophilic Ag colloid) While stirring 560 ml of an aqueous sodium citrate solution (32% by mass), an aqueous solution of ferrous sulfate (30% by mass) was stirred. 100 ml were added. After the mixture is mixed uniformly, the silver nitrate aqueous solution (10
% By mass) was added so that the addition was completed within 30 seconds. After about 10 minutes, stirring was stopped. Finished A
g In order to remove unnecessary salts in the colloid, the colloid was washed with water (ultrafiltration) using an ultrafiltration apparatus. Ultrafiltration equipment is US A
The CH2PRS type manufactured by Micon was used, and SIY30 (cutoff molecular weight 30,000) was used as a filter. Rinsing was performed until the conductivity reached about 50 μS / cm. After washing with water, the Ag concentration was adjusted to 6% by mass. The average particle size of the Ag colloid was 18 nm.

(Formation of heat-sensitive layer) An aqueous coating solution having the following composition was prepared by dispersing with a paint shaker for 10 minutes.
The aluminum support was coated with a bar coater so that the dry film mass became 3.0 g / m ² , and then dried in an oven at 80 ° C. for 10 minutes.

(Composition of Thermal Sensitive Layer (2) Coating Solution) Titanium oxide powder (manufactured by Wako Pure Chemical Industries, Ltd., rutile type, average particle size: 0.2 μm) 20 g PVA117 (manufactured by Kuraray Co., Ltd.) 5% aqueous solution 70 g colloidal silica Dispersion 20% aqueous solution 60 g Prepared aqueous silver colloid solution (6% by mass) 150 g Sol-gel preparation solution 28 g Synthesized microcapsule (1) (solid content 9.5%) 115 g Water 20 g

The sol-gel preparation used here has the following composition.

(Sol-gel preparation liquid: room temperature, aged for 2 hours) Tetraethoxysilane 15.0 g Ethanol 30.0 g 0.1 mol / L nitric acid 4.5 g

(Formation of Overcoat Layer) Next, the overcoat layer coating solution (OC-1, Example 8), (OC-2, Example 9),
(OC-3, Example 10), (OC-4, Example 1)
1), (OC-5, Example 12), (OC-6, Example 13), (OC-7, Example 14), (OC-8, Comparative Example 3) After drying for 1 minute, a heat-sensitive lithographic printing plate precursor having an overcoat layer having a dry coating weight of about 1.0 g / m ² was prepared. Also, a lithographic printing plate precursor without an overcoat layer was prepared, and Comparative Example 4 was made.

The lithographic printing plate precursors thus obtained were subjected to sensory evaluation for the degree of sticking of the front and back surfaces when 3000 sheets were stacked and stored at 35 ° C. and 75% temperature and humidity for 3 days. At the same time, the coefficient of kinetic friction of the surface was measured by a measuring method according to standard ASTM D1894, as described above. PEARLs is used as a laser beam scanning exposure system.
plate energy: 200 mJ / cm ² , resolution: 2400 dpi using ETER74 (manufactured by Presstek)
Exposure was performed under the conditions described above, and an image area thermally fused to the exposed portion surface was formed. RYOBI-3200MCD was used as a printing machine, a 1% by volume aqueous solution of EU-3 (manufactured by Fuji Photo Film Co., Ltd.) was used as a dampening solution, and GEOS (N) black was used as an ink. First, roll-up (run-in operation) was performed 10 times with dampening water, and then ink was supplied to perform printing. At that time, the number of sheets until the non-image portion was not stained was examined (shown in Table 2 as the number of damaged sheets). The occurrence rate of scratches and stains was determined by examining the occurrence rate of stains when rubbing and printing 100 parts of the lithographic printing plate precursor with aluminum pieces.

[0151]

[Table 2]

As is clear from the results in Table 2, the lithographic printing plate precursors of Examples 8 to 14 of the present invention were prepared by adding an appropriate amount of a compound containing a fluorine atom or a silicon atom (release agent) to the overcoat layer. , The dynamic friction coefficient becomes a specified value (2.
5 or less), there is no sticking between the plates and no scratches and stains are generated. In particular, the lithographic printing plate precursors of Examples 8 to 13 have satisfactory results with a small number of waste sheets, but comparative examples. The lithographic printing plate precursors of Nos. 3 and 4 (having a coefficient of kinetic friction of 2.5 or more) were unsatisfactory in sticking between plates and flaws and stains.

[0153]

According to the lithographic printing plate precursor of the present invention, the heat-sensitive layer on the support contains microcapsules containing a compound having a heat-reactive group and a hydrophilic polymer binder. By providing an overcoat layer made of a water-soluble polymer compound on the layer and satisfying that the dynamic friction coefficient described below of the surface of the formed overcoat layer is 2.5 or less, it shows good on-press developability. However, the film strength of the image area heated by heat mode exposure or the like is improved, and the printing durability is excellent. Furthermore, it has become possible to prevent sticking between planographic printing plate precursors during long-term storage caused by the water-soluble polymer compound.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AA12 AB03 AC08 AD01 BH03 BJ03 CB54 CC17 DA03 DA05 DA10 FA10 2H096 AA06 BA06 CA20 EA04 EA23 2H114 AA04 AA14 AA22 AA24 AA27 DA23 DA25 DA27 DA28 DA52 DA46 DA50 DA50 EA10 FA06 FA14 FA16

Claims (3)

[Claims] 1. A heat-sensitive layer containing a microcapsule containing a compound having a functional group that reacts by heat on a support, and a water-soluble overcoat layer on the heat-sensitive layer; A lithographic printing plate precursor characterized in that a coefficient of dynamic friction when one surface slides on another surface is 2.5 or less. 2. The lithographic printing plate precursor according to claim 1, wherein the water-soluble overcoat layer contains a light-to-heat conversion material. 3. The water-soluble overcoat layer contains a compound having at least one of a fluorine atom and a silicon atom.
The lithographic printing plate precursor described.