JPH1130867A - Original plate for planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for a planographic printing plate capable of directly making the plate from digital data by recording with an IR laser, etc., without requiring wet development or special treatment such as rubbing after image exposure and in which the image forming property is not deteriorated even in the case of storing it under a high humidity condition over a long period of time. SOLUTION: A recording layer contg. a high molecular compd. having a functional group that generates sulfonic acid by heating in a side chain and an IR absorber and an overcoating layer contg. an inorg. laminar compd. are successively laminated on a substrate. The aspect ratio of the inorg. laminar compd. is >=20, preferably >=100, further preferably >=200 and the compd. is preferably mica such as fluorine-contg. synthetic mica.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor, and more particularly to a lithographic printing plate precursor that can be directly made by operating an infrared laser based on a digital signal.

[0002]

2. Description of the Related Art Conventionally, as a method of directly making a printing plate from digitized image data without passing through a lithographic film, an electrophotographic method or a method of writing with a relatively small output laser emitting blue or green light is available. A method using a sensitive photopolymer, a method using a silver salt or a composite system of a silver salt and another system, a method of generating an acid by heat mode laser exposure, and obtaining a thermosetting image by post-heating using the acid as a catalyst, etc. Are known.

Although these methods are extremely useful in streamlining the printing process, they are not always satisfactory at present. For example, in the case of using the electrophotographic method, an image forming process such as charging, exposure, and development is complicated, and the apparatus is complicated and large. Further, in the case of using the photopolymer, since a printing plate having high sensitivity is used, it is difficult to handle in a bright room. The method using a silver salt has disadvantages such as complicated processing and silver contained in the processing waste liquid. Also requires post-heating and subsequent development processing, which complicates the processing.

[0004] Further, in the production of these printing plates, after the exposure process, a wet development process for removing the recording layer provided on the surface of the support in an image-like manner or a printing plate subjected to the development process is used. A post-treatment step of washing with water, or treating with a rinse solution containing a surfactant, gum arabic, or a desensitizing solution containing a starch derivative is included.

On the other hand, in the plate making and printing industries in recent years, plate making operations have been rationalized, and a printing plate precursor that does not require the complicated wet developing process as described above and can be used for printing directly after exposure is desired. ing.

As a lithographic printing plate precursor which does not require wet development after image formation, a plate material provided with a silicone layer and a laser heat-sensitive layer below the silicone layer is disclosed in US Pat. No. 5,353,70.
No. 5, US Pat. No. 5,379,698. Although these do not require wet development, they have the disadvantage of requiring rubbing to complete the removal of the silicone layer by laser abrasion and processing with a special roller, which makes the processing complicated.

Japanese Patent Application Laid-Open No. 5-77574 discloses a method for forming a lithographic printing plate precursor which does not require a developing process by using a film obtained by sulfonating polyolefins and changing the hydrophilicity of the surface by thermal writing. And JP-A-4-125189, US Pat. No. 5,187,047, and JP-A-62-195646. In this system, the sulfone group on the surface of the printing plate is desulfonated by thermal writing to form an image, and development processing is not required. However, there is a disadvantage in that harmful gas is generated during writing.

US Pat. No. 5,102,771, US Pat. No. 5,22
No. 5,316 discloses a lithographic printing plate precursor in which a polymer having an acid-sensitive group in the side chain and a photoacid generator are combined, and a development-free system is proposed. Since the acid generated is a carboxylic acid, this lithographic printing plate precursor has only a limited hydrophilic property, and has a disadvantage that the durability of the plate material and the sharpness of a printed image are poor.

Further, Japanese Patent Laid-Open No. 7-186562 (EP65)
No. 2,483) discloses a lithographic printing plate precursor containing a polymer that generates a carboxylic acid by the action of heat and an acid, and an infrared absorbing dye. However, a lithographic printing plate using this lithographic printing plate precursor has a problem in that stains occur during printing.

[0010] Considering these problems, the present inventors have obtained:
According to a lithographic printing plate having a recording layer containing a polymer compound having a functional group capable of generating sulfonic acid in a side chain upon heating and an infrared absorber, plate making can be directly performed based on a digital signal, and after image exposure. No special processing such as wet development processing or rubbing was found to be necessary.
No. 26878. The present invention is a further improvement of the present invention, and prevents the deterioration of image formability when stored for a long time under high humidity conditions, which is a practical problem of a lithographic printing plate, and preserves when stored under severe conditions. It is intended to improve the performance.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to make a plate directly from digital data by recording using a solid-state laser or a semiconductor laser that emits infrared rays. It is an object of the present invention to provide a lithographic printing plate precursor that does not require special treatment such as rubbing and does not deteriorate in image formability even when stored for a long time under high humidity conditions.

[0012]

The object of the present invention is to provide a recording medium comprising a polymer having a functional group capable of generating sulfonic acid by heating in a side chain thereof and an infrared absorbing agent, and an inorganic layered compound. This was achieved by using a lithographic printing plate precursor in which an overcoat layer was sequentially laminated. Here, the aspect ratio of the inorganic layered compound contained in the overcoat layer is preferably 20 or more, more preferably 100 or more, and more preferably 200 or more. Further, the inorganic layered compound contained in the overcoat layer is preferably mica, and more preferably a swellable fluorine-based synthetic mica.

In the present invention, by combining a high molecular compound having a functional group capable of generating sulfonic acid on heating in a side chain with an infrared absorbing agent, a good positive heat generated by irradiation with an infrared laser can be obtained without a developing step. A mold image is obtained, and the overcoat layer containing an inorganic layered compound does not inhibit the transmission of infrared laser and can effectively prevent the transmission of moisture and oxygen, so that image forming properties, sensitivity, etc. It is characterized in that excellent storage stability under high humidity conditions can be achieved without impairing the characteristics of the recording layer.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The lithographic printing plate precursor according to the invention is provided with a recording layer formed of an image recording material on a support and an overcoat layer containing an inorganic layered compound. Next, each configuration will be described.

[Overcoat layer] The overcoat layer disposed as the uppermost layer of the lithographic printing plate precursor according to the present invention comprises:
It is provided to inhibit the influence of the outside air on the compound constituting the photosensitive layer and the compound generated in the photosensitive layer by exposure to actinic rays. For this reason, it is preferable that the material has low permeability to any of oxygen, water vapor and other low molecular compounds present in the air and low molecular compounds generated in the photosensitive layer. That is, the overcoat layer inhibits the incorporation of a base that traps an acid generated during exposure in the photosensitive layer, or prevents water, a base, and an acid present in the air that inhibit a reaction that occurs in the photosensitive layer. It is preferable that a compound such as oxygen or the like can be prevented from being mixed into the photosensitive layer, and that the overcoat layer remaining in the non-image portion after exposure can be easily removed.

As described above, the characteristics of the overcoat layer suitable for a lithographic printing plate precursor include the following:
A film or a film having low gas permeability can be formed, and the adhesiveness with the recording layer is excellent.
As a result of intensive studies, the present inventors have found that an overcoat layer exhibiting excellent performance can be obtained by using an inorganic layered compound having the following physical properties together with a suitable binder.

The inorganic stratiform compound used in the present invention is represented by the general formula A (B, C) _2-5 D ₄ O ₁₀ (OH, F,
O) ₂ [where A is any of K, Na and Ca, B and C are any of FeII, FeIII, Mn, Al, Mg and V, and D is Si or Al. Mica groups such as natural mica and synthetic mica represented by the general formula 3MgO.4Si
Examples include talc, teniolite, montmorillonite, saponite, hectorite, and zirconium phosphate represented by O.H ₂ O.

In the above mica group, natural mica includes muscovite, soda mica, phlogopite, biotite and scale mica. As synthetic mica, fluorphlogopite mica KMg
₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicic mica KMg
Non-swelling mica, such as _2.5 Si ₄ O ₁₀ ) F ₂ , and Natetrasilyl mica NaMg _2.5 (Si ₄ O ₁₀ ) F ₂ ,
Na or Li teniolite (Na, Li) Mg ₂ Li
(Si ₄ O ₁₀ ) F ₂ , montmorillonite-based Na or L
i hectorite _{(Na, Li) 1/8 Mg 2} /5 Li
_{1/8 (Si 4 O 10} ) swelling mica F _2. Further, synthetic smectite is also useful.

In the present invention, among the above-mentioned inorganic layered compounds, fluorine-based swellable mica which is a synthetic inorganic layered compound is particularly useful. That is, the swelling synthetic mica, swelling viscosity minerals such as montmorillonite, saponite, hectorite, bentonite and the like are 10-1.
It has a laminated structure consisting of unit crystal lattice layers with a thickness of about 5 °, and the substitution of metal atoms in the lattice is significantly larger than other viscous minerals. As a result, the lattice layer has a shortage of positive charges, and cations such as Na ⁺ , Ca ²⁺ , and Mg ²⁺ are adsorbed between the layers to compensate for the shortage. The cations interposed between these layers are called exchangeable cations and exchange with various cations. In particular, when the cations between the layers are Li ⁺ and Na ⁺ , the bond between the layered crystal lattices is weak because the ionic radius is small, and the swells greatly with water. When shear is applied in this state, it is easily cleaved and forms a stable sol in water. Bentonite and swellable synthetic mica have a strong tendency and are useful in the present invention. In particular, swellable synthetic mica is preferably used.

The shape of the inorganic layered compound used in the present invention is preferably as thin as possible from the viewpoint of diffusion control, and the planar size does not impair the smoothness of the coated surface and the transmittance of actinic rays. The larger the better, the better. Therefore, the aspect ratio is 20 or more, preferably 100
The number is particularly preferably 200 or more. The aspect ratio is a ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projection of a particle by a micrograph. The greater the aspect ratio, the greater the effect obtained.

The average particle diameter of the inorganic layered compound used in the present invention is 0.3 to 20 μm, preferably 0.5 to 10 μm, and particularly preferably 1 to 5 μm.
The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less.
m or less. For example, among the inorganic stratiform compounds, the swellable synthetic mica which is a representative compound has a thickness of 1 to 5 mm.
0 nm, and the surface size is about 1 to 20 μm.

When the particles of the inorganic layered compound having a large aspect ratio are contained in the overcoat layer, the strength of the coating film is improved and the permeation of oxygen and moisture can be effectively prevented. Deterioration of the overcoat layer is prevented, and even when stored for a long time under high humidity conditions, the storage stability is excellent without a decrease in image formability of the lithographic printing plate precursor due to a change in humidity.

The amount of the inorganic layered compound contained in the overcoat layer is preferably from 5/1 to 1/100 by weight based on the amount of the binder used in the overcoat layer. The amount of the inorganic layered compound is 1 in the weight comparative example.
If it is less than / 100, there is no effect of adding the inorganic layered compound, and if it exceeds 5/1, the coating film may be cracked. Even when a plurality of inorganic stratiform compounds are used in combination, it is preferable that the total amount of these inorganic stratiform compounds is the above-mentioned weight ratio.

The binder used in the overcoat layer of the present invention is not particularly limited as long as it has good dispersibility of the inorganic layered compound and can form a uniform film in close contact with the photosensitive layer. Both the water-soluble polymer and the water-insoluble polymer can be appropriately selected and used. Specifically, for example, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, partially saponified polyvinyl acetate, ethylene-vinyl alcohol copolymer, water-soluble cellulose derivative, gelatin, starch derivative, Arabic Examples include water-soluble polymers such as rubber, and water-insoluble polymers such as polyvinylidene chloride, poly (meth) acrylonitrile, polysulfone, polyvinyl chloride, polyethylene, polycarbonate, polystyrene, polyamide, and cellophane. These can be used in combination of two or more as necessary. Among these, a water-soluble polymer is preferable from the viewpoint of easy removal of the overcoat layer remaining in the non-image portion and handling properties at the time of film formation,
Water-soluble acrylic resins such as polyvinyl alcohol, polyvinylpyrrolidone, and polyacrylic acid, gelatin, gum arabic, and the like are preferable. Among them, water can be used as a solvent, and easily removed by fountain solution during printing. In view of the fact, polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, gum arabic and the like are more preferable.

The polyvinyl alcohol which can be used in the overcoat layer according to the present invention is partially substituted with an ester, ether or acetal as long as it contains a substantial amount of unsubstituted vinyl alcohol units having the required water solubility. You may. Further, similarly, a part thereof may contain another copolymerization component. As a specific example of polyvinyl alcohol, 71-100% is hydrolyzed and the degree of polymerization is 300-2.
400 range. Specifically, Kuraray's PVA-105, PVA-110, PVA-117, PVA-117H, PVA-1
20, PVA-124, PVA124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, P
VA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA
-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA-420,
PVA-613, L-8 and the like. Examples of the copolymer include polyvinyl acetate chloroacetate or propionate hydrolyzed 88 to 100%, polyvinyl formal and polyvinyl acetal, and copolymers thereof.

Next, an example of a general dispersion method of the inorganic layer compound used in the overcoat layer will be described. First, 5 to 10 parts by weight of the swellable layered compound mentioned above as a preferable inorganic layered compound is added to 100 parts by weight of water, and is sufficiently blended with water, swelled, and then dispersed by a dispersing machine. Examples of the disperser used here include various mills for dispersing by applying direct mechanical force, a high-speed stirring type disperser having a large shearing force, and a disperser for applying high-intensity ultrasonic energy. Specifically, a ball mill, a sand grinder mill, a biscomil, a colloid mill, a homogenizer, a tisolver, a polytron, a homomixer, a homoblender, a Keddy mill, a jet agitator,
Examples include a capillary emulsifier, a liquid siren, an electromagnetic strain type ultrasonic generator, and an emulsifier having a Paulman whistle. 5 to 10% by weight of the inorganic stratiform compound dispersed by the above method
Are highly viscous or gel-like, and have very good storage stability. In preparing an overcoat layer coating solution using this dispersion, it is preferable to dilute with water, stir well, and then blend with a binder solution.

Known additives such as a surfactant for improving coating properties and a water-soluble plasticizer for improving physical properties of the film can be added to the overcoat layer coating solution. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. In addition, a water-soluble (meth) acrylic polymer can be added. Further, a known additive for improving the adhesion to the recording layer and the stability over time of the coating solution may be added to the coating solution. The overcoat layer coating solution thus prepared is applied on a recording layer provided on a support, and dried to form an overcoat layer. The coating solvent can be appropriately selected in relation to the binder, but when using a water-soluble polymer, it is preferable to use distilled water or purified water. The overcoat layer is coated on the recording layer by a known coating method such as a blade coating method, an air knife coating method, a gravure coating method, a roll coating method, a spray coating method, a dip coating method, and a bar coating method. The coating amount of the overcoat layer is preferably in the range of 0.5 to 10 g / cm ² , more preferably 1 to 5 g / cm ² , in terms of the coating amount after drying.

As the image recording material contained in the recording layer,
Examples include a polymer compound having a functional group capable of generating sulfonic acid on heating in a side chain (hereinafter, referred to as a sulfonic acid-generating polymer compound) and an infrared absorber. [Sulfonic acid-generating polymer compound] As the sulfonic acid-generating polymer compound used in the present invention, a polymer compound having a functional group represented by the following general formula (1), (2) or (3) in a side chain Is mentioned.

[0029]

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(Wherein L represents an organic group comprising a polyvalent non-metallic atom necessary for linking the functional group represented by the general formula (1), (2) or (3) to the polymer skeleton; R ¹ represents a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group or a cyclic imide group, R ² and R ³ represent a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group, and R ⁴ represents substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group or -SO ₂ -R ⁵
And R ⁵ represents a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group. )

Among these, the lithographic printing plate precursor containing the compound represented by the general formula (1) is disclosed in US Pat.
No. 4,906. The present inventor has found that, as described above, such a compound is decomposed by heat to generate sulfonic acid, and the present invention combines this compound with an infrared absorbent to develop a developing process. It is characterized in that a good positive-type image can be obtained by the heat generated by the irradiation of the infrared laser even without the above. The polymer compound having at least one of the functional groups represented by the general formulas (1), (2) and (3) in the present invention will be described more specifically.

When R ^{1 to} R ⁵ represent an aryl group or a substituted aryl group, the aryl group includes a carbocyclic aryl group and a heterocyclic (hetero) aryl group. As the carbocyclic aryl group, those having 6 to 19 carbon atoms such as a phenyl group, a naphthyl group, an anthracenyl group and a pyrenyl group are used. Examples of the heterocyclic aryl group include a pyridyl group, a furyl group, and other quinolyl groups, benzofuryl groups, thioxanthone groups, thioxanthone groups, and carbazole groups in which a benzene ring is condensed. Things are used. When R ^{1 to} R ⁵ represent an alkyl group or a substituted alkyl group, examples of the alkyl group include linear, branched or cyclic carbon atoms such as methyl, ethyl, isopropyl, t-butyl, and cyclohexyl. Those from 1 to 25 are used.

When R ^{1 to} R ⁵ are a substituted aryl group, a substituted heteroaryl group or a substituted alkyl group, examples of the substituent include an alkoxy group having 1 to 10 carbon atoms such as a methoxy group and an ethoxy group, a fluorine atom, and a chlorine atom. Atom, halogen atom such as bromine atom, trifluoromethyl group, halogen-substituted alkyl group such as trichloromethyl group, methoxycarbonyl group, ethoxycarbonyl group, t-butyloxycarbonyl group, p-chlorophenyloxycarbonyl group, etc. An alkoxycarbonyl group or an aryloxycarbonyl group having 2 to 15 carbon atoms; a hydroxyl group; an acyloxy group such as an acetyloxy group, a benzoyloxy group, a p-diphenylaminobenzoyloxy group; a carbonate group such as a t-butyloxycarbonyloxy group; t-butyloxycarbonyl Ether groups such as tyloxy group and 2-pyranyloxy group; substituted and unsubstituted amino groups such as amino group, dimethylamino group, diphenylamino group, morpholino group and acetylamino group; thioether groups such as methylthio group and phenylthio group; vinyl An alkenyl group such as a group or styryl group; a nitro group; a cyano group; an acyl group such as a formyl group, an acetyl group or a benzoyl group; an aryl group such as a phenyl group or a naphthyl group; be able to. When R ^{1 to} R ⁵ are a substituted aryl group or a substituted heteroaryl group, an alkyl group such as a methyl group or an ethyl group can be used as the substituent other than the above.

When R ¹ represents a cyclic imide group, cyclic imides such as succinimide, phthalimide, cyclohexanedicarboxylic imide, norbornenedicarboxylic imide and the like having 4 to 20 carbon atoms can be used. .

Among the above, particularly preferred as R ¹ are an aryl group substituted with an electron-withdrawing group such as halogen, cyano and nitro; an alkyl group substituted with an electron-withdrawing group such as halogen, cyano and nitro; They are a secondary or tertiary branched alkyl group, a cyclic alkyl group and a cyclic imide. Of the above, particularly preferred as R ^{2 to} R ⁵ are an aryl group substituted with an electron-withdrawing group such as halogen, cyano and nitro, and an alkyl group substituted with an electron-withdrawing group such as halogen, cyano and nitro. And secondary or tertiary branched alkyl groups.

A polyvalent linking group consisting of a nonmetallic atom represented by L means 1 to 60 carbon atoms, 0 to 10 carbon atoms.
Up to nitrogen atoms, 0 to 50 oxygen atoms, 1
From 100 to 100 hydrogen atoms and 0 to 20 sulfur atoms. More specific linking groups include those constituted by combining the following structural units.

[0037]

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When the polyvalent linking group has a substituent, examples of the substituent include an alkyl group having 1 to 20 carbon atoms such as a methyl group and an ethyl group, and a carbon atom having 6 carbon atoms such as a phenyl group and a naphthyl group.
To 16 aryl groups, hydroxyl groups, carboxyl groups,
An acyloxy group having 1 to 6 carbon atoms such as a sulfonamide group, an N-sulfonylamide group, an acetoxy group, an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group, and a halogen such as chlorine and bromine. An atom, an alkoxycarbonyl group having 2 to 7 carbon atoms such as a methoxycarbonyl group, an ethoxycarbonyl group, and a cyclohexyloxycarbonyl group, a cyano group, and a carbonate group such as t-butyl carbonate can be used.

Specific examples of the monomers suitably used for synthesizing the high molecular compound having a functional group represented by the general formula (1) to (3) in the side chain according to the present invention are shown below.

[0040]

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[0041]

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[0042]

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[0043]

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In the present invention, preferably, the compounds represented by the general formulas (1) to (1)
A polymer compound obtained by radical polymerization of at least one of the monomers having a functional group represented by (3) is used. As such a polymer compound, a homopolymer using only one of the monomers having a functional group represented by the general formulas (1) to (3) may be used, but two or more kinds thereof are used. Copolymers or copolymers of these monomers with other monomers may be used. In the present invention, a polymer compound more preferably used is a copolymer obtained by radical polymerization of the above-mentioned monomer and another known monomer.

Other monomers include glycidyl methacrylate, N-methylol methacrylamide, omega-
(Trimethoxysilyl) propyl methacrylate, 2-
Monomers having crosslinking reactivity such as isocyanate ethyl acrylate are preferred. Further, as other monomers used in the copolymer, for example, acrylates,
Known monomers such as methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, and maleic imide are also included.

Specific examples of acrylic esters include:
Methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec-
Or t-) butyl acrylate, amyl acrylate,
2-ethylhexyl acrylate, dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
5-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, chlorobenzyl acrylate, hydroxybenzyl acrylate, hydroxyphenethyl acrylate, dihydroxyphenethyl acrylate, furfuryl acrylate, Examples thereof include tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyphenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate, and 2- (hydroxyphenylcarbonyloxy) ethyl acrylate.

Specific examples of the methacrylates include methyl methacrylate, ethyl methacrylate,
(N- or i-) propyl methacrylate, (n-, i
-, Sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate,
Dodecyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate,
Glycidyl methacrylate, benzyl methacrylate,
Methoxybenzyl methacrylate, chlorobenzyl methacrylate, hydroxybenzyl methacrylate, hydroxyphenethyl methacrylate, dihydroxyphenethyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, hydroxyphenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate, 2- (hydroxyphenyl Carbonyloxy) ethyl methacrylate and the like.

Specific examples of acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide, and N-benzylacrylamide.
Hydroxyethylacrylamide, N-phenylacrylamide, N-tolylacrylamide, N- (hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl)
Acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-
N-phenylacrylamide, N-hydroxyethyl-
N-methylacrylamide and the like can be mentioned.

Specific examples of methacrylamides include methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, N-propyl methacrylamide, N-butyl methacrylamide, N-benzyl methacrylamide, N-hydroxyethyl methacryl Amide,
N-phenylmethacrylamide, N-tolylmethacrylamide, N- (hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N
-(Tolylsulfonyl) methacrylamide, N, N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like.

Specific examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate and the like.

Specific examples of styrenes include styrene,
Methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, propylstyrene, cyclohexylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene, methoxystyrene, dimethoxystyrene,
Chlorostyrene, dichlorostyrene, bromostyrene,
Examples thereof include iodostyrene, fluorostyrene, carboxystyrene and the like.

Of these other monomers, particularly preferably used are acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid esters of C20 or less. Acid and acrylonitrile. The proportion of the monomer having a functional group represented by any of the general formulas (1) to (3) used in the synthesis of the copolymer is preferably from 5 to 99% by weight, more preferably from 10 to 95% by weight.
It is.

Hereinafter, specific examples of the high molecular compound having the functional groups represented by the general formulas (1) to (3) in the side chain are shown.

[0054]

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[0055]

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[0056]

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[0057]

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The numbers in the formula represent the molar composition of the polymer compound.

Further, the compounds represented by the general formulas (1) to (1) used in the present invention:
The weight average molecular weight of the polymer compound having at least one of the functional groups represented by (3) is preferably 200
0 or more, more preferably in the range of 5000 to 300,000, the number average molecular weight is preferably 800 or more,
More preferably, it is in the range of 1,000 to 250,000. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1 or more, more preferably in the range of 1.1 to 10. These polymer compounds may be any of a random polymer, a block polymer, a graft polymer and the like, but are preferably a random polymer.

Examples of the solvent used for synthesizing the sulfonic acid-generating polymer compound used in the present invention include, for example, tetrahydrofuran, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol Glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, toluene,
Examples include ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, water and the like. These solvents are used alone or in combination of two or more. As the radical polymerization initiator used when synthesizing the sulfonic acid generating polymer compound used in the present invention, known compounds such as an azo initiator and a peroxide initiator can be used.

The sulfonic acid-generating polymer compound used in the present invention may be used alone or as a mixture. These sulfonic acid-generating polymer compounds are used in an amount of 50 to 90% by weight, preferably 70 to 90% by weight based on the total solids of the image recording material.
Can be used in proportions. If the amount is less than 50% by weight, the printed image becomes unclear. When the amount of addition is 9
If the amount exceeds 0% by weight, image formation by laser exposure cannot be sufficiently performed.

[Infrared absorber] The infrared absorber used in the present invention is a dye or pigment that effectively absorbs infrared rays having a wavelength of 760 nm to 1200 nm. Preferably, the dye or the pigment has an absorption maximum at a wavelength of 760 nm to 1200 nm. 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, cyanine dyes, and dyes such as metal thiolate complexes. Preferred dyes include, for example, those described in
125246, JP-A-59-84356, JP-A-5-84356
Cyanine dyes described in JP-A-9-202829 and JP-A-60-78787;
JP-A-58-181690, JP-A-58-194
No. 595, etc .;
Naphthoquinone dyes described in JP-A-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. JP-A-58-112
792 and the cyanine dyes described in British Patent No. 434,875, and the like.

The near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and the substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924 is also preferable. JP-A-57-142645 (U.S. Pat. No. 4,327,169) describes a trimethinethiapyrylium salt described in JP-A-58-181051, and JP-A-58-181051, and JP-A-58-181051.
Nos. 8-220143, 59-41363 and 59-
No. 84248, No. 59-84249, No. 59-146
Nos. 063 and 59-146061; cyanine dyes described in JP-A-59-216146; pentamethine thiopyrylium salts described in U.S. Pat. No. 4,283,475; Fairness 5-135
Nos. 14 and 5-19702 are also preferably used. Further, as another preferable example of the dye, a near-infrared absorbing dye described as formulas (I) and (II) in U.S. Pat. No. 4,756,993 can be exemplified. Examples of commercially available dyes include NK2014 and NK3555 manufactured by Nippon Kogaku Dye Co., Ltd.
NKX114, NK2545, NK3508, NK35
09, SIR128, SIR13 manufactured by Mitsui Toatsu Dye Co., Ltd.
0, SIR132, SIR103, SIR152, KI
R103, IRG022, IRG00 manufactured by Nippon Kayaku
2. Cyso by Glendal, such as IRG003
eb IR99, etc., Epollight manufactured by Epoline
tIV62B, EpollightIII 178, Epoli
ghtIII 125, EpollightIII 130, Ep
lightV72, ElightV99, Epo
lightIII 117, EpollightIII 189,
EpolightIII 57, EpolightIV62
A, Epollight IV101, Epollight III
184, Epollight III 192, Epollight
tIV67, EpollightV63 and the like. Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes.

The pigment used in the present invention includes
Commercial Pigment 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" CMC Publishing, 1984)
Can be used. The types of pigments include black pigment, yellow pigment, orange pigment, brown pigment,
Red pigment, purple pigment, blue pigment, green pigment, fluorescent pigment,
Metal powder pigments and other polymer-bound dyes can be used.
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. Preferred among these pigments is carbon black.

These pigments may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. Examples of the surface treatment include a method of surface-coating a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (for example, a silane coupling agent, an epoxy compound, or a polyisocyanate) to the pigment surface. 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). I have.

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. Pigment particle size 0.01μ
When it is less than m, the dispersion is not preferred in terms of stability in the coating solution for the photosensitive layer, and when it exceeds 10 μm, it is not preferred in terms of uniformity of the image recording layer. 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).

These dyes or pigments are used in an amount of 0.01 to 50% by weight, preferably 0.1 to 1% by weight of the total solids of the image recording material.
0% by weight, particularly preferably 0.5 to 10% by weight for dyes, and particularly preferably 3.1 to 10% by weight for pigments. If the amount of the pigment or dye added is less than 0.01% by weight, the sensitivity becomes low,
If the amount exceeds the weight percentage, stains occur in the non-image area during printing.

[Other Components] In the present invention, the above two components are indispensable, but various compounds other than these may be added as necessary. For example, 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 # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603,
Oil Black BY, Oil Black BS, Oil Black T-505 (or more, Orient Chemical Industries, Ltd.)
Manufactured), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42
535), ethyl violet, rhodamine B (CI1
45170B), malachite green (CI4200
0), methylene blue (CI52015) and the dyes described in JP-A-62-293247. It is preferable to add these dyes because they fade after laser exposure and the image area and the non-image area are easily distinguished. The amount of addition is 0.01 to 10% by weight of the total solids of the image recording material.

The recording layer according to the present invention has a structure disclosed in Japanese Patent Application Laid-Open No. 62-2517 in order to increase stability under printing conditions.
Non-ionic surfactants described in JP-A-59-121 and JP-A-3-208514.
Further, an amphoteric surfactant as described in JP-A-0444 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 Daiichi Kogyo Co., Ltd.) and the like. The proportion of the nonionic surfactant and amphoteric surfactant in the image recording material is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

Further, a plasticizer is added to the recording layer of the present invention, if necessary, in order to impart flexibility 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, oligomers of acrylic acid or methacrylic acid And polymers.

In addition to these, epoxy compounds, vinyl ethers, phenol compounds having a hydroxymethyl group and phenol compounds having an alkoxymethyl group described in Japanese Patent Application No. 7-18120 may be added. Further, another polymer compound may be added to improve the strength of the coating film.

The lithographic printing plate precursor according to the present invention can be usually produced by dissolving the above-mentioned components in a solvent and coating the solution on a suitable support. As the solvent used herein, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, toluene,
Water and the like can be mentioned, but it is not limited thereto. 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 amount of coating (solid content) on the support obtained after coating and drying varies depending on the intended use, but generally speaking about the lithographic printing plate precursor, it is not more than 0.1%.
5~5.0g / m ² is preferred. As a method of applying, various methods can be used, for example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating,
Roll coating and the like can be mentioned.

The recording layer in the present invention may have a surfactant for improving coating properties, for example, JP-A-62-17095.
No. 0 can be added. The amount of these added is preferably from 0.01 to 1% by weight, more preferably from 0.05 to 0.5% by weight, based on the total solid content of the image recording material.

The support used in the present invention is preferably a dimensionally stable plate-like material, for example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (Eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl) Acetal, etc.), paper or plastic film on which the above-mentioned metal is laminated or vapor-deposited. As the support of the present invention, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate having good dimensional stability and relatively low cost is particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. Aluminum which is particularly preferred in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, particularly preferably 0.2 mm to 0.3 mm.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is performed to remove the rolling oil on the surface. The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. It is performed by the method of causing. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. Further, as an electrochemical surface roughening method, there is a method of performing an alternating current or a direct current in a hydrochloric acid or nitric acid electrolyte. Further, a method combining both of them can be used as disclosed in JP-A-54-63902.

As described above, the lithographic printing plate precursor of the present invention can be prepared. The lithographic printing plate precursor is image-exposed by a solid-state laser and a semiconductor laser that emit infrared light having a wavelength of 760 nm to 1200 nm.
In the present invention, printing may be performed by mounting a printing plate on a printing machine immediately after laser irradiation, but it is preferable to perform heat treatment between the laser irradiation step and the printing step. The heat treatment is preferably performed in a range of 80 ° C. to 150 ° C. for 10 seconds to 5 minutes. By this heat treatment, the laser energy required for recording at the time of laser irradiation can be reduced.

The planographic printing plate obtained by such a process is set on an offset printing machine or the like and used for printing a large number of sheets.

[0078]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples.

[Synthesis of Sulfonic Acid Generating Polymer Compound] Synthesis of Monomer (4) 200 ml of acetonitrile, 11 g of cyclohexyl alcohol and 8.8 g of pyridine were put into a 500 ml three-necked flask and stirred. While cooling with ice, 20.2 g of vinylbenzenesulfonyl chloride was added dropwise. After the dropwise addition, the mixture was stirred at room temperature for 2 hours, poured into 1 liter of water, and extracted with ethyl acetate. After drying over magnesium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by column chromatography using silica gel to obtain a monomer (4). The calculated values of the elemental analysis were as follows: C: 63.13%, H: 6.
81%, the measured values are C: 63.01%, H: 6.8.
5%.

[0080] to obtain a monomer monomer synthetic method similar other monomers using 2,2,2-trifluoroethyl alcohol instead of synthetic cyclohexyl alcohol (5) (4) (5).

[0081] obtained in Synthesis method similar monomers other using alcohol below instead of the synthetic cyclohexyl alcohol monomer (28) (4) monomer (28).

[0082]

Embedded image

Synthesis of Monomer (23) 88.8 g of N-methylstyrenesulfonamide, 109.3 g of triethylamine and dimethylaminopyridine5.
5 g and 200 ml of acetonitrile were placed in a 1-liter three-necked flask. The three-necked flask was cooled, and 119.2 g of benzenesulfonyl chloride dissolved in 200 ml of acetonitrile was added dropwise with stirring over 1 hour. After the dropwise addition, stirring was continued at room temperature for 2 hours, and then left overnight. The reaction solution was poured into 800 ml of water, and 500 ml of ethyl acetate was added.
, dried over magnesium sulfate and concentrated.
The concentrate was purified using silica gel chromatography (hexane / ethyl acetate = 3/1 (volume ratio) was used), and then recrystallized using 300 ml of isopropyl alcohol. 80. White crystals with a melting point of 58.5-60 ° C.
3 g were obtained. The absorption spectrum of this crystal (THF
(Center) was λmax of 265 nm, and ε was 2.0 × 10 ⁴ . The elemental analysis value (actual measurement value) was C: 53.2.
1%, H: 4.53%, N: 4.17%.

Synthesis of sulfonic acid-generating polymer compound (1)
Forming monomer (4) 7.18 g, and glycidyl methacrylate 0.43g and methyl ethyl ketone 15 g 100 ml
, And 0.1 g of azobisdimethylvaleronitrile was added thereto under a nitrogen stream at 65 ° C. After stirring at the same temperature for 5 hours, methyl ethyl ketone was distilled off under reduced pressure to obtain a solid. The polymer was found to have a weight average molecular weight of 188,000 by GPC (polystyrene standard).

Synthesis of sulfonic acid-generating polymer compound (2)
Forming monomer (4) 7.18 g, trimethoxy propyl methacryloyloxy 0.74g and methyl ethyl ketone 15g
Was placed in a 100 ml three-necked flask, and 0.1 g of azobisdimethylvaleronitrile was added under a nitrogen stream at 65 ° C. After stirring at the same temperature for 5 hours, methyl ethyl ketone was distilled off under reduced pressure to obtain a solid. The polymer was found to have a weight average molecular weight of 12,000 by GPC (polystyrene standard).

Sulfonic acid generating polymer compound (3),
Monomer (5) in place of 7.18 g of synthetic monomer (4) of (4)
A polymer having a weight-average molecular weight of 35,000 (GPC, polystyrene standard) was obtained in the same manner as in the method of synthesizing the sulfonic acid-generating polymer compound (1) except that 7.18 g was used [sulfonic acid-generating polymer] Polymer compound (3)]. Also, instead of 7.18 g of monomer (4), monomer (28)
A polymer having a weight average molecular weight of 23,000 (GPC, polystyrene standard) was obtained in the same manner as in the method for synthesizing the sulfonic acid-generating polymer compound (2) except that 9.32 g was used [sulfonic acid-generating polymer] Polymer compound (4)].

Sulfonic acid-generating polymer compounds 5, 7-1
0 synthetic sulfonic acid-generating polymer compounds (5), (7) to (1)
0) was also synthesized in the same manner as above. Weight average molecular weight (G
PC, polystyrene standard) are 31,000 and 1.5, respectively.
It was 10,000, 20,000, 131,000, and 41,000.

The sulfonic acid-generating polymer compound (11)
20 g of monomer (4) and 40 g of methyl ethyl ketone were put into a 200 ml three-necked flask at a synthesis temperature of 65 ° C. under a nitrogen stream.
0.25 g of azobisdimethylvaleronitrile was added.
After stirring at the same temperature for 5 hours, the solvent was distilled off under reduced pressure to obtain a solid. The polymer was found to have a weight average molecular weight of 104,000 by GPC (polystyrene standard).

(Examples 1 to 8) Al having a thickness of 0.30 mm
Trichlorethylene cleaning of minium plate (material 1050)
And degrease, then use a nylon brush and 400 mesh
Use a miston-water suspension to grain the surface and use water
Washed well. This plate is made of 25% sodium hydroxide at 45 ° C.
Etching for 9 seconds in an aqueous solution
2% HNO _ThreeFor 20 seconds and washed with water. At this time
The amount of etching of the grained surface is about 3g / m^TwoSo
Was. Next, this plate is_TwoSO_FourCurrent density as electrolyte
Degree 15A / dm^Two3g / m^TwoDC anodized film
After drying, it was washed with water and dried.

Next, in the following solution [A], eight kinds of solutions [A-1] to [A-8] were prepared by changing the kind of the sulfonic acid-generating polymer compound. Each of the solutions was applied to the above treated aluminum plate,
Dry at 2 ° C. for 2 minutes. The weight after drying was 1.2 g / m ² .

Solution [A] Sulfonic acid-generating polymer compound (Table 1) 1.0 g Infrared absorbent 0.15 g (NK-3508, manufactured by Nippon Kogaku Dyestuff Research Institute Co., Ltd.) 1-naphthalene-0.05 g Dye converted into sulfonic acid Fluorinated surfactant 0.06 g (MegaFac F-177, manufactured by Dainippon Ink and Chemicals, Inc.) Methyl ethyl ketone 20 g Methyl alcohol 7 g

[0092]

[Table 1]

[Preparation of Overcoat Layer Liquid] (1) Preparation of Mica Dispersion A synthetic mica (Somasif ME-100: trade name, manufactured by Corp Chemical Co., Ltd., aspect ratio: 100) was added to 184 g of water.
(0 or more) was added and dispersed using a homogenizer until the average particle diameter (laser scattering method) became 3 μm, to obtain a mica dispersion.

(2) Preparation of Coating Solution for Overcoat Layer 100 g of water was added to 6 g of the adjusted mica dispersion, 12 g of an 8% by weight aqueous solution of polyvinyl alcohol (PVA-124 manufactured by Kuraray Co., Ltd.) was added, and the mixture was stirred well. 10 g of a 2% by weight solution of sodium 2-ethylhexylsulfosuccinate was added,
An overcoat layer coating solution was obtained. Next, a water-soluble overcoat layer coating solution having the above composition was applied on a plate on which a photosensitive layer having the above formulation was applied, and the weight after drying was 1.0 g / m 2.
² ) and dried at 100 ° C. for 3 minutes to obtain lithographic printing plate precursors [A-1] to [A-8].

The obtained lithographic printing plate precursors [A-1] to
[A-8] was converted to YA emitting infrared light having a wavelength of 1064 nm.
Exposure was performed with a G laser. After the exposure, the film was heated at 110 ° C. for 1 minute, and then printed by a Heidel KOR-D machine. On this occasion,
It was observed whether or not stains had occurred on the non-image portion of the printed matter. Table 2 shows the results. In each case, good prints without stains on the non-image areas were obtained. Next, the master [A-1]
Using [A-8] stored at 45 ° C. and a relative humidity of 75% for 3 days, plate-making and printing were performed under the same conditions as described above, and the same evaluation was performed. Table 2 shows the results. In each case, good prints without stains on the non-image areas were obtained.

[0096]

[Table 2]

Comparative Examples 1 to 8 In Examples 1 to 8,
Except that the overcoat layer was not provided, the lithographic printing plate precursors [A'-1] to [A'-] were prepared in the same manner as in Examples 1 to 8.
8] was prepared. Exposure, heating, and printing were performed on the original plate in the same manner as in Examples 1 to 8. As a result, good prints were obtained with no stain on the non-image area. Next, the masters [A'-1] to [A'-8] were placed at 45 ° C and a relative humidity of 75%.
The plate making and printing were performed under the same conditions as above using the one stored for 3 days under the above conditions, and evaluated similarly. Table 3 shows the results. In each case, stains were observed in the non-image areas, and clear images could not be obtained.

[0098]

[Table 3]

(Examples 9 to 12) In the following solution [B], the type of the sulfonic acid-generating polymer compound was changed to
Various types of solutions [B-1] to [B-4] were prepared. Each of the solutions was applied to the undercoated aluminum plate used in Examples 1 to 8, dried at 100 ° C. for 2 minutes, and further heated at 100 ° C. for 10 minutes to form a photosensitive layer. The weight after drying was 1.7 g / m ² .

Solution [B] Sulfonic acid generating polymer compound (Table 4) 0.6 g Phthalic anhydride 0.005 g Orthochlorophenol 0.001 g Infrared absorbent NK-2268 0.15 g )) Novolak resin obtained from cresol and formaldehyde 1.2 g (meta: para ratio = 8: 2, weight average molecular weight 5800) Resol resin obtained from bisphenol A and formaldehyde 1.0 g (weight average molecular weight 1600) Victoria Pure Blue BOH counter ion 1-naphthalene-0.03 g Sulfonic acid dye Fluorosurfactant 0.06 g (MegaFac F-177, manufactured by Dainippon Ink and Chemicals, Inc.) Methyl ethyl ketone 20 g Methyl alcohol 7 g

[0101]

[Table 4]

Next, an overcoat layer was applied on the plate on which the photosensitive layer having the above formulation was applied in the same manner as in Examples 1 to 8, and the lithographic printing plate precursors [B-1] to [B- 4] was obtained. The resulting lithographic printing plate precursors [B-1] to [B-4]
Was stored for 3 days under a high-temperature and high-humidity condition at a temperature of 45 ° C. and a humidity of 75%, and then exposed to a semiconductor laser emitting infrared light having a wavelength of 830 nm. After the exposure, the plate was heated at 110 ° C. for 1 minute, and the plate was treated with gum GU-7 (1: 1) manufactured by Fuji Photo Film Co., Ltd. without passing through a developing machine.
Printing was performed with an RD machine. At this time, it was observed whether or not stains occurred on the non-image portion of the printed matter. Table 5 shows the results. In each case, good prints without stains on the non-image areas were obtained.

[0103]

[Table 5]

(Comparative Examples 9 to 12) In Examples 9 to 12, except that the overcoat layer was not provided.
In the same manner as in Example 12, the lithographic printing plate precursor [B'-1] ~
[B'-4] was prepared. Examples 1 to 3
Exposure, heating and printing were performed in the same manner as in No. 8, and good prints were obtained with no stain on the non-image area. next,
The masters [B'-1] to [B'-4] were used at 45 ° C and a relative humidity of 7
Plate making and printing were carried out under the same conditions as described above using those stored for 3 days under the condition of 5%, and evaluation was performed in the same manner. Table 6 shows the results. In each case, the non-image area was stained, the image area was uneven, and a clear image was not obtained.

[0105]

[Table 6]

[0106]

According to the present invention, plate making can be directly performed by an infrared laser, no special processing such as wet development processing or rubbing after image exposure is required, the printed image is clear, and high humidity conditions can be attained. It is possible to provide a lithographic printing plate precursor in which image formability does not deteriorate even when stored for a long period of time.

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI G03F 7/004 506 G03F 7/004 506 7/039 501 7/039 501

Claims (6)

[Claims] 1. A recording layer comprising a polymer compound having a functional group capable of generating sulfonic acid by heating in a side chain thereof and an infrared absorbent, and an overcoat layer containing an inorganic layered compound on a support, A lithographic printing plate precursor characterized by being sequentially laminated. 2. The lithographic printing plate precursor according to claim 1, wherein the inorganic layered compound contained in the overcoat layer has an aspect ratio of 20 or more. 3. The lithographic printing plate precursor according to claim 1, wherein the inorganic layered compound contained in the overcoat layer has an aspect ratio of 100 or more. 4. The lithographic printing plate precursor according to claim 1, wherein the inorganic layered compound contained in the overcoat layer has an aspect ratio of 200 or more. 5. The lithographic printing plate precursor as claimed in claim 1, wherein the inorganic layered compound contained in the overcoat layer is mica. 6. The lithographic printing plate precursor according to claim 1, wherein the inorganic layered compound contained in the overcoat layer is a swellable fluorine-based synthetic mica.