JP2008076967A - Lithographic printing plate original plate and method for producing lithographic printing plate using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithographic printing plate original plate having high sensitivity, high productivity of a printing plate and good developability even in development with a mild aqueous solution (pH: 2-10) and capable of providing a lithographic printing plate excellent in printing durability, and a method for producing the lithographic printing plate. <P>SOLUTION: The lithographic printing plate original plate has on a support a photosensitive layer containing a polymerizable compound having a specific partial structure and a binder polymer having an acid value of ≤0.3 meq/g. The method for producing the lithographic printing plate comprises imagewise exposing the lithographic printing plate original plate with a laser beam of 360-450 nm, and rubbing the surface of the exposed lithographic printing plate original plate with a rubbing member in the presence of a developer having pH of 2-10 in an automatic processor equipped with the rubbing member to remove the unexposed area of the photosensitive layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lithographic printing plate precursor and a method for producing a lithographic printing plate using the same, and in particular, a lithographic printing plate precursor that can be developed with a mild aqueous solution (pH 2 to 10) and a lithographic printing using the same. The present invention relates to a plate manufacturing method.

In general, a lithographic printing plate has a surface composed of an oleophilic image portion and a hydrophilic non-image portion. In lithographic printing, dampening water and oil-based ink are alternately applied to the plate surface, and the hydrophilic non-image area is dampened with a dampening water receiving area (ink non-receiving area) by utilizing the property that water and oil repel each other. ), And after the ink is received only in the oleophilic image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive layer (image recording layer) is provided on a hydrophilic support has been widely used. Usually, after exposing a lithographic printing plate precursor through an original image such as a lithographic film, the image recording layer to be an image portion is left, and other unnecessary image recording layers are washed with an alkaline developer or an organic solvent. The lithographic printing plate is obtained by carrying out plate making by a method in which the surface of the hydrophilic support is exposed by dissolving and removing to form a non-image portion.

In the conventional plate making process of a lithographic printing plate precursor, a step of dissolving and removing unnecessary image recording layers with a developer or the like is necessary after exposure, but simplifies such additional wet processing. Is one of the issues. As one of simplifications, it is desired that development is possible with an aqueous solution close to neutrality or simple water.
On the other hand, in recent years, digitization technology that electronically processes, stores, and outputs image information using a computer has become widespread, and various new image output methods corresponding to such digitization technology have been put into practical use. It has come to be. Along with this, digitized image information is carried by high-convergence radiation such as laser light, and the lithographic printing plate precursor is scanned and exposed with that light, directly without using a lithographic film. Computer-to-plate technology for manufacturing is attracting attention. Accordingly, obtaining a lithographic printing plate precursor adapted to such a technique is one of the important technical issues.

From the background as described above, it is now more strongly desired than ever to adapt both the simplification of the plate making operation and the digitization.
On the other hand, for example, in Patent Document 1, in an image forming layer of a lithographic printing plate precursor having an image forming layer containing a hydrophobic precursor, a hydrophilic resin, and a photothermal conversion agent on a hydrophilic support. In addition to on-press development, it can be used for printing after being exposed to a liquid development treatment using water or a suitable aqueous solution as a developer, by containing a compound having an ethylene oxide chain. ing.
Patent Document 2 contains (i) a hydrophilic support, and (ii) a radical polymerizable ethylenically unsaturated monomer, a radical polymerization initiator and an infrared absorbing dye, and is cured by infrared laser exposure. In addition, a lithographic printing plate precursor comprising an oleophilic thermosensitive image forming layer containing 60% by mass or more of water and developable with an aqueous developer having a pH of 2.0 to 10.0 is prepared and exposed imagewise with an infrared laser. And a processing method for a lithographic printing plate precursor comprising removing an uncured region of the heat-sensitive layer with an aqueous developer.
However, in the lithographic printing plate precursor described in the above-mentioned patent document, the hydrophilicity of the image forming layer is set to be high for development with an aqueous developer, so that the water resistance of the image area is weak and a sufficient number of printed sheets cannot be obtained. In addition, since the exposure is performed with a high-energy infrared laser, the productivity of the printing plate is low.

On the other hand, as a method for increasing the productivity of a printing plate, there is a printing plate precursor called a photon mode using a laser beam in a low energy visible light to ultraviolet region.
For example, Patent Document 3 discloses a photopolymerizable composition comprising a compound having a structure represented by the following general formula (A) and a photopolymerization initiator, and a lithographic printing plate precursor using the same. Are listed.

[Wherein, X ¹ and X ² each independently represent a hetero atom or a halogen atom, R ^a and R ^b each represent ^a hydrogen atom, a halogen atom, a cyano group or an organic residue, and X ¹ , X ² , A ring may be formed by any two combinations of R ^a and R ^b . ]
Patent Document 4 discloses a photopolymerizable composition comprising a compound having a structure represented by the following general formula (B) and a photopolymerization initiator, and a lithographic printing plate precursor using the same. Are listed.

[In the formula, A represents an aryl group substituted with an alkoxy group or an alkylthio group, X represents a hetero atom or a halogen atom, and R ^a and R ^b represent ^a hydrogen atom, a halogen atom, a cyano group, an organic residue, respectively. Represents a group, and any two combinations of A, X, R ^a and R ^b may form a ring. ]

Patent Documents 3 and 4 describe development of a lithographic printing plate precursor using an alkaline aqueous solution and a solvent.
According to the lithographic printing plate precursor described in Patent Documents 3 and 4 above, a printing plate having high sensitivity and good storage stability can be obtained, but development with an aqueous developer having an acidic to weak alkaline region with a pH of 2 to 10 is not possible. Impossible. As described above, a lithographic printing plate precursor having high productivity, high printing durability, and rapid development with an acidic to weakly alkaline aqueous solution has not been obtained so far.
JP 2002-365789 A US Patent Application Publication No. 2004/0013968 JP 2001-92127 A JP 2003-171420 A

The present invention provides a lithographic printing plate having high sensitivity, high printing plate productivity, good developability even in development with a mild aqueous solution (pH 2 to 10), and excellent printing durability. An object of the present invention is to provide a lithographic printing plate precursor and a plate making method capable of performing the above.

As a result of intensive studies to achieve the above-mentioned problems, the present inventor has a polymerizable compound having a partial structure represented by the general formula (1) on the support and an acid value of 0.3 meq / g or less. The inventors have found that the above object can be achieved by using a lithographic printing plate precursor having a photosensitive layer containing a binder polymer, and have achieved the present invention.
That is, the present invention is as follows.

(1) A lithographic printing plate precursor having a photosensitive layer containing a polymerizable compound having a partial structure represented by the following general formula (1) and a binder polymer having an acid value of 0.3 meq / g or less on a support. .

In the formula, X represents a functional group linked by any one of a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom, and Y is linked by any one of an oxygen atom, a nitrogen atom, a carbon atom, and a sulfur atom. R ₁ and R ₂ each independently represent a hydrogen atom, a halogen atom, a cyano group, or an organic residue, or a ring formed by any two or more of R ₁ , R ₂ , X, and Y May be formed.

(2) The lithographic printing plate precursor as described in (1), wherein the polymerizable compound has two or more partial structures represented by the general formula (1) in the molecule.
(3) The lithographic printing plate precursor as described in (1) or (2), wherein the photosensitive layer further contains a sensitizing dye having an absorption maximum in a wavelength range of 350 to 450 nm.
(4) The lithographic printing plate precursor as described in any one of (1) to (3), wherein a protective layer is provided on the photosensitive layer.

(5) After the lithographic printing plate precursor according to any one of (1) to (4) is image-exposed with a 350 to 450 nm laser, the pH is 2 to 10 by an automatic processor equipped with a rubbing member. A method for preparing a lithographic printing plate, comprising removing a photosensitive layer in a non-exposed portion by rubbing the plate surface with a rubbing member in the presence of the developer.
(6) The method for producing a lithographic printing plate as described in (5), wherein the exposed lithographic printing plate precursor is subjected to heat treatment between image exposure and development processing.

According to the present invention, there is provided a lithographic printing plate having high sensitivity, high printing plate productivity, good developability even in development with a mild aqueous solution (pH 2 to 10), and excellent printing durability. It is possible to provide a lithographic printing plate precursor that can be used and a plate making method thereof.
In the present invention, the achievement of such an effect is considered to be based on the following operation mechanism. That is, the polymerizable compound having a partial structure represented by the general formula (1) has a characteristic that it has higher hydrophilicity than a polymerizable compound such as a normal acrylate, methacrylate, acrylamide, or methacrylamide. Thereby, the lithographic printing plate precursor having a photosensitive layer containing such a polymerizable compound is improved in developability with an aqueous solution having a pH of 2 to 10. On the other hand, since the polymerizable compound has very high radical polymerizability, it is considered that the polymerization and curing proceeds more than the ordinary polymerizable compound, and the printing durability is improved.

Hereinafter, the lithographic printing plate precursor according to the invention will be described in detail.
The lithographic printing plate precursor used in the present invention comprises, on a support, a photosensitive layer containing a polymerizable compound having a partial structure represented by the general formula (1) and a binder having an acid value of 0.3 meq / g or less. It is characterized by having.
The lithographic printing plate precursor will be described in more detail below.

(Photosensitive layer)
The photosensitive layer of the lithographic printing plate precursor according to the invention can be removed by rubbing the plate surface with a rubbing member in the presence of a developer having a pH of 2 to 10 in the non-exposed portion. 1 is a polymerizable negative photosensitive layer comprising a photosensitive compound comprising a polymerizable compound having a partial structure represented by 1) and a binder having an acid value of 0.3 meq / g or less. The photosensitive layer contains a polymerization initiator, and further contains a sensitizing dye, a colorant and other optional components as necessary.
The polymerizable negative photosensitive layer in the present invention is sensitive to light of a blue laser (350 nm to 450 nm) useful for CTP, and therefore a sensitizing dye that absorbs light in the same wavelength region is added. Such a sensitizing dye that absorbs light of 350 nm to 450 nm is in an electronically excited state with high sensitivity to the irradiation (exposure) of a blue laser, and the electron transfer, energy transfer, and the like related to the electron excited state are present in the photosensitive layer. It acts on the coexisting polymerization initiator and causes a chemical change in the polymerization initiator to generate radicals. Then, the polymerizable compound causes a polymerization reaction by the generated radical, and the exposed portion is cured to become an image portion.

In the lithographic printing plate precursor according to the invention, an intermediate layer (also referred to as an undercoat layer) may be provided for the purpose of improving the adhesion and soiling between the photosensitive layer and the support. Further, in order to perform exposure in the air, a protective layer (also referred to as an overcoat layer) may be further provided on the photosensitive layer. The protective layer prevents exposure of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that hinder the image formation reaction caused by exposure in the photosensitive layer, and enables exposure in the atmosphere. To do.
The lithographic printing plate precursor according to the invention is particularly suitable for a plate making method in which a photosensitive layer contains a sensitizing dye that absorbs light of 350 nm to 450 nm and is directly drawn with blue laser light having a wavelength of 350 nm to 450 nm. In addition, it can exhibit high image-forming properties as compared with conventional lithographic printing plate precursors.
Below, each component which comprises the photosensitive composition which forms the photosensitive layer of the lithographic printing plate precursor concerning this invention is demonstrated.

<Polymerizable compound>
The polymerizable compound used in the present invention is a polymerizable compound having a partial structure represented by the following general formula (1).

In the formula, X represents a functional group linked by any one of a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom, and Y is linked by any one of an oxygen atom, a nitrogen atom, a carbon atom, and a sulfur atom. R ₁ and R ₂ each independently represent a hydrogen atom, a halogen atom, a cyano group, or an organic residue, or a ring formed by any two or more of R ₁ , R ₂ , X, and Y May be formed.

In the present specification, the “polymerizable compound having a partial structure represented by the general formula (1)” means a polymerizable compound represented by the general formula (1), that is, R ₁ in the general formula (1), A polymerizable compound having not only a polymerizable compound in which any of the atoms or groups represented by R ₂ , X and Y is a monovalent atom or group but also a plurality of structures represented by the general formula (1), In addition, a polymerizable compound in which any of the groups represented by R ₁ , R ₂ , X and Y in the general formula (1) is a divalent or higher group is also included.

As X in the general formula (1), any functional group linked by any one of a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom can be suitably used. Such a functional group is preferably a functional group linked by an oxygen atom, a nitrogen atom, or a sulfur atom, specifically, —OR ₃ , —OCOR ₃ , —OCOOR ₃ , —OSO ₃ R ₃ , —OSO ₃ M _{, -OSO 2 NR 3 R 4,} -OCONR 3 R 4, -OSO 2 R 3, -OP (O) OR 3 OR 4, -OP (O) OR 3 R 4, -NR 3 R 4, -NR 3 _{COR 4, -NR 3 SO 2 R} 4, -NR 3 SO 3 R 4, -NR 3 SO 2 NR 4 R 5, -NR 3 COOR 4, -NR 3 CONR 4 R 5, -SR 3, -SO 2 _{NR 3 R 4, -SOR 3,} -SO 2 R 3, -SO 3 R 3, -SO 3 M (R 3 ~R 5 is a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, an alkenyl group, an alkynyl Group, heterocyclic group Represents, may form a ring with R ₃ and R _4, M is more preferably a functional group represented by represents a metal ion), among these functional groups, R ₃ to R ₅ are hydrogen, carbon C1-C6 alkyl group, C6-C12 aryl group, C1-C12 heteroaryl group, C1-C6 alkenyl group, C1-C6 alkynyl group, C1-C12 The heterocyclic group is particularly preferred.

As Y in the general formula (1), any functional group linked by any of an oxygen atom, a nitrogen atom, a sulfur atom, and a carbon atom can be suitably used. Such a functional group is preferably a functional group linked by an oxygen atom or a nitrogen atom. Specifically, —OR ₃ , —NR ₃ R ₄ (R ₃ , R ₄ are a hydrogen atom, an alkyl group, an aryl group, A functional group represented by a group, a heteroaryl group, an alkenyl group, an alkynyl group, or a heterocyclic group.
As R ₁ and R ₂ in the general formula (1), any of a hydrogen atom, a halogen atom, a cyano group, and an organic residue can be preferably used. Preferred as such a functional group are a hydrogen atom and an organic residue. Specific examples of such organic residues include alkyl groups, aryl groups, alkenyl groups, and alkynyl groups.

  Specific examples of the alkyl group include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group. Group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl Group, cyclopentyl group, 2-norbornyl group, chloromethyl group, bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxymethyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tri Ruthiomethyl group, ethylaminoethyl Group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2 -Oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl Group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfur group Moylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, Diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonatooxybutyl group, benzyl group Phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2- Methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3- Ethynyl group, and the like.

  Specific examples of the aryl group include, for example, a phenyl group, a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a mesityl group, a cumenyl group, a chlorophenyl group, a bromophenyl group, a chloromethylphenyl group, a hydroxyphenyl group, and a methoxyphenyl group. , Ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl Group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophene Examples include a nyl group and a phosphonatophenyl group.

  Specific examples of the heteroaryl group include, for example, thiophene, thiathrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine. Lysine, indoyl, indazole, purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, sinoline, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanthrolin, phthalazine, phenalazine, phenoxazine, furazane, phenoxazine, etc. And monovalent groups derived from a heteroaryl ring.

  Specific examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 1-butenyl group, a cinnamyl group, and a 2-chloro-1-ethenyl group. Specific examples of the alkynyl group include ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group and the like.

  Specific examples of the heterocyclic group include monovalent groups derived from the following heterocyclic rings. That is, thiazoles (for example, thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4,5-di (p -Methoxyphenylthiazole), 4- (2-thienyl) thiazole, etc.), benzothiazoles (eg, benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole 4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 4-phenylbenzothiazole, 5-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole, 6 -Methoxybenzothiazole, 5 -Iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, 5-hydroxybenzothiazole , 6-hydroxybenzothiazole, 6-dimethylaminobenzothiazole, 5-ethoxycarbonylbenzothiazole, etc.), naphthothiazoles (for example, naphtho [1,2] thiazole, naphtho [2,1] thiazole, 5-methoxynaphtho [ 2,1] thiazole, 5-ethoxynaphtho [2,1] thiazole, 8-methoxynaphtho [1,2] thiazole, 7-methoxynaphtho [1,2] thiazole, etc.), thianaphtheno-7 ′, 6 ′, 4 , 5-thiazoles (eg 4′-methoxythiathia Naphtheno-7 ′, 6 ′, 4,5-thiazole and the like), oxazoles (for example, 4-methyloxazole, 5-methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4, 5-dimethyloxazole, 5-phenyloxazole, etc.), benzoxazoles (benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole 4,6-dimethylbenzoxazole, 6-methoxybenzoxazole, 5-methoxybenzoxazole, 4-ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole, 5-hydroxybenzoxazole, 6-hydride Loxybenzoxazole), naphthoxazoles (for example, naphtho [1,2] oxazole, naphtho [2,1] oxazole, etc.), selenazoles (for example, 4-methylselenazole, 4-phenylselenazole, etc.), benzo Selenazoles (eg, benzoselenazole, 5-chlorobenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.), naphthoselenazoles (eg, naphtho [1,2 Selenazole, naphtho [2,1] selenazole etc.), thiazolines (eg thiazoline, 4-methylthiazoline etc.), quinolines (eg quinoline, 3-methylquinoline, 5-methylquinoline, 7-methylquinoline, 8 -Methylquinoline, 6-chloroquinoline, 8-chloroquinoline , 6-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline, etc.), isoquinolines (eg, isoquinoline, 3,4-dihydroisoquinoline, etc.), benzimidazoles (eg, 1,3- Diethylbenzimidazole, 1-ethyl-3-phenylbenzimidazole, etc.), 3,3-dialkylindolenins (for example, 3,3-dimethylindolenine, 3,3,5-trimethylindolenine, 3,3, 7, -trimethylindolenine, etc.), pyridines (eg, pyridine, 5-methylpyridine, etc.), benzodithiols (eg, benzodithiol, 5-t-butylbenzodithiol, 5-methylbenzodithiol, etc.), naphthodithiol (For example, naphtho [1,2] dithiol, naphtho [2,1] dithiol, etc.) Dithiols (for example, 4,5-dimethyldithiols, 4-phenyldithiols, 4-methoxycarbonyldithiols, 4,5-dimethoxycarbonylbenzodithiols, 4,5-ditrifluoromethyldithiols, 4,5- Dicyanodithiol, 4-methoxycarbonylmethyldithiol, 4-carboxymethyldithiol, etc.).

  Specific examples of metal ions include sodium ions, potassium ions, lithium ions, magnesium ions, calcium ions, iron ions, aluminum ions, cobalt ions, nickel ions, zinc ions, copper ions, silver ions, and the like. it can.

  The polymerizable compound used in the present invention can be suitably used as long as it is a polymerizable compound having a partial structure represented by the general formula (1), but the moiety represented by the general formula (1) A polymerizable compound having two or more structures is more preferable. Examples of the polymerizable compound include polymerizable compounds represented by the following general formulas (2) to (5).

_Wherein, X 1, _{X 2} has the same meaning as X in formula _(1), Y 1, _{Y 2} has the same meaning as the general formula _{(1) Y, R 11 ~R} 14 is formula (1 ) has the same meaning as _{R 1,} Z 1, _{Z 2} is an organic residue of valence _n, Z 3, _{Z 4} is an organic residue of a + b value, n represents an integer of 2 to 10, a and b represent an integer of 1 or more and 10 or less. Alternatively, any two or more of X ₁ , X ₂ , Y ₁ , Y ₂ , R _{11 to} R ₁₄ , and Z _{1 to} Z ₄ may form a ring. X ₁ and X ₂ in formula (4) and Y ₁ and Y ₂ in formula (5) are different from each other.

The organic residue represented by Z _{1 to} Z ₄ is composed of at least one atom selected from carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus, silicon, boron, and halogen. Specifically, for example, Z ₁ and Z ₃ may include an oxygen, nitrogen, sulfur, phosphorus, silicon, boron, or halogen atom connected by any atom of oxygen, nitrogen, sulfur, and carbon. Examples thereof include the above aliphatic groups, oxygen, nitrogen, sulfur, phosphorus, silicon, boron, divalent or higher aromatic groups that may contain halogen atoms, and divalent or higher heterocyclic groups. Z ₂ and Z ₄ are a divalent or higher valent aliphatic group that may contain oxygen, nitrogen, sulfur, phosphorus, silicon, boron, or halogen atoms connected by any atom of oxygen, nitrogen, sulfur, and phosphorus. Oxygen, nitrogen, sulfur, phosphorus, silicon, boron, a divalent or higher-valent aromatic group that may contain a halogen atom, a divalent or higher-valent heterocyclic group, and the like.

  Specific examples of the polymerizable compound having a partial structure represented by the general formula (1) used in the present invention are shown below. The present invention is not limited to these.

  The photosensitive layer of the lithographic printing plate precursor according to the invention may contain another polymerizable compound in addition to the polymerizable compound having the partial structure represented by the general formula (1). Such a polymerizable compound is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is selected from compounds having at least one, preferably two or more terminal ethylenically unsaturated bonds. Such a compound group is widely known in the industrial field, and can be used without particular limitation as long as the effects of the present invention are not impaired. These have chemical forms such as monomers, prepolymers, ie dimers, trimers and oligomers, or copolymers thereof and mixtures thereof. Examples of monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids. An ester of an acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, isocyanuric acid ethylene oxide (EO) Examples include modified triacrylates and polyester acrylate oligomers.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, JP-A-59- Those having an aromatic skeleton described in JP-A No. 5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.
Furthermore, the ester monomers described above can also be used as a mixture.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

  Further, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable. Specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinylurethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula (A) to a polyisocyanate compound having two or more isocyanate groups Etc.

_{CH 2 = C (R 4)} COOCH 2 CH (R 5) OH (A)
(However, R ₄ and R ₅ represent H or CH _3. )

JP-A-51-37193, JP-B-2-32293, JP-B-2-16
Urethane acrylates such as those described in JP-B No. 765, and ethylene oxides described in JP-B 58-49860, JP-B 56-17654, JP-B 62-39417, and JP-B 62-39418 Urethane compounds having a system skeleton are also suitable. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the case, it is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and JP-A-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. In addition, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid-based compounds described in JP-A-2-25493 are also included. Can be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

About these polymerizable compounds, the details of usage such as the structure, single use or combination, addition amount, etc. can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of sensitivity, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image portion, that is, the cured film, those having three or more functionalities are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrene compound, vinyl ether type). A method of adjusting both sensitivity and strength by using a compound) is also effective.
In addition, the compatibility and dispersibility with other components in the photosensitive layer (for example, binder polymer, polymerization initiator, colorant, etc.), the selection and use method of the polymerizable compound is an important factor. In some cases, the compatibility can be improved by using a low-purity compound or by using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving adhesion to a support or a protective layer described later.
In addition, as for the method of using the polymerizable compound, an appropriate structure, blending and addition amount can be arbitrarily selected from the viewpoints of polymerization inhibition with respect to oxygen, resolution, antifogging property, refractive index change, surface tackiness, and the like.

The polymerizable compound having a partial structure represented by the general formula (1) according to the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, based on the total polymerizable compound contained in the photosensitive layer. More preferably.
The total amount of the polymerizable compound is preferably 5 to 80% by mass, more preferably 25 to 75% by mass, based on the total solid content of the photosensitive layer.

<Binder polymer having an acid value of 0.3 meq / g or less>
The binder polymer (hereinafter also simply referred to as a binder) used in the photosensitive layer of the present invention has an acid value (the acid content per gram of polymer expressed in terms of the number of chemical equivalents) of 0.3 meq / g or less. The binder preferably does not substantially contain an acid group such as a carboxyl group, a sulfone group, or a phosphoric acid group. The acid value of the binder is preferably 0.1 meq / g or less. If the acid value exceeds 0.3 meq / g, problems such as deterioration in developability (generation of residual film) and reduction in printing durability due to increase in hydrophilicity may occur.

Moreover, it is preferable that the binder used for this invention is substantially insoluble with respect to water and aqueous solution of pH 10 or more. The solubility of the binder in water and an aqueous solution having a pH of 10 or more (polymer concentration at saturation dissolution) is preferably 1.0% by mass or less. The solubility measurement temperature is 25 ° C., which is a normal temperature during plate-making development.
By using such a binder, it is possible to improve the printing durability by improving the film strength, water resistance and inking property of the photosensitive layer while maintaining good developability with respect to an aqueous developer.

As the binder, as long as the performance of the lithographic printing plate precursor according to the present invention is not impaired, a conventionally known one can be used without limitation as long as the acid value is satisfied, and a linear organic polymer having a film property is preferable.
Examples of such binders include polymers selected from acrylic resins, methacrylic resins, styrene resins, polyvinyl acetal resins, polyurethane resins, polyamide resins, epoxy resins, and polyester resins. Especially, vinyl copolymers, such as an acrylic resin, a methacryl resin, and a styrene resin, are preferable.

  Such a vinyl copolymer can be obtained by using a known vinyl monomer and adjusting the type and amount ratio of the monomer so as to have the above properties (acid value, solubility, etc.). Examples of vinyl monomers include (meth) acrylic acid esters, crotonic acid esters, vinyl esters, maleic acid diesters, fumaric acid diesters, itaconic acid diesters, (meth) acrylamides, vinyl ethers, Styrenes and (meth) acrylonitrile are preferred. Specific examples of such compounds include the following compounds.

 Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, acetoxyethyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate , Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, diethylene glycol monomethyl ether (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, diethylene glycol monophenyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, tri Ethylene glycol monoethyl ether (meth) acrylate, dipropylene glycol monomethyl ether (meth) acrylate, polyethylene glycol monomethyl ether (meth) acrylate, polypropylene glycol monomethyl ether (meth) acrylate, monomethyl copolymer of ethylene glycol and propylene glycol Ether (meth) acrylate, N, N-di Chill aminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate.

Examples of the crotonic acid esters include butyl crotonic acid and hexyl crotonic acid. Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl methoxyacetate, vinyl benzoate and the like.
Examples of maleic acid diesters include dimethyl maleate, diethyl maleate, and dibutyl maleate. Examples of the fumaric acid diesters include dimethyl fumarate, diethyl fumarate, dibutyl fumarate and the like. Examples of the itaconic acid diesters include dimethyl itaconate, diethyl itaconate, and dibutyl itaconate.

Examples of (meth) acrylamides include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, Nn butylacryl (meth) amide, N-tert. Butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N -Phenyl (meth) acrylamide, N-benzyl (meth) acrylamide, (meth) acryloylmorpholine, etc. are mentioned.
Examples of vinyl ethers include methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, and methoxyethyl vinyl ether.

Styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropyl styrene, butyl styrene, hydroxy styrene, methoxy styrene, butoxy styrene, acetoxy styrene, chloro styrene, dichloro styrene, bromo styrene, chloromethyl styrene, Examples include methyl vinylbenzoate and α-methylstyrene.
In addition, vinyl pyridine, vinyl pyrrolidone, vinyl carbazole, (meth) acrylonitrile and the like can also be used.
A vinyl monomer having a urethane group or a urea group can also be used. Examples of such a compound include the following compounds.

In order to form an image with a developer having a pH of 2 to 10 using a binder having an acid value of 0.3 meq / g or less, a vinyl monomer having a non-acidic hydrophilic group is used as a component of the binder. It is preferable to use some.
Examples of hydrophilic groups include hydroxy groups, carboxylate groups, hydroxyethyl groups, ethyleneoxy groups, hydroxypropyl groups, amino groups, aminoethyl groups, aminopropyl groups, ammonium groups, amide groups, carboxymethyl groups, and the like. Polyether groups (diethylene oxide, triethylene oxide, polyethylene oxide, dipropylene oxide, tripropylene oxide, polypropylene oxide, ditetramethylene oxide, tritetramethylene oxide, polytetramethylene oxide, combinations thereof, etc.) It is preferable to use a vinyl monomer having such a hydrophilic group.
More specifically, R of the ester residue (—COOR) of (meth) acrylic acid ester is —CH ₂ CH ₂ O— unit, —CH ₂ CH (CH ₃ ) O— unit or —CH ₂ CH _2. Copolymers containing at least one kind such as (meth) acrylic acid esters containing NH units, hydroxyl group-containing (meth) acrylic acid esters, (meth) acrylamides and the like are particularly preferred. Moreover, 5-70 mol% is preferable, as for the ratio of the vinyl monomer which has a hydrophilic group in the binder of this invention, 10-60 mol% is more preferable, and 15-50 mol% is especially preferable. If the ratio of the vinyl monomer having a hydrophilic group is less than 5 mol%, the developability may be lowered, and if it exceeds 70 mol%, the printing durability may be lowered.

  A polyurethane resin can also be preferably used as the binder for the photosensitive layer. The polyurethane resin is obtained by a polyaddition reaction between a known diisocyanate compound and a diol compound. The type and amount ratio of the diisocyanate compound and the diol compound are appropriately adjusted so as to have the above-mentioned characteristics (acid value, solubility, etc.). Can be obtained.

1) Diisocyanate compound Examples of the diisocyanate compound include the following. Preferred is a diisocyanate compound represented by the following general formula (6).

OCN-L ¹ -NCO (6)

In General Formula (6), L ¹ represents a divalent aliphatic or aromatic hydrocarbon group which may have a substituent. If necessary, L ¹ may have another functional group that does not react with an isocyanate group, such as an ester, urethane, amide, or ureido group.

Specific examples of the diisocyanate compound represented by the general formula (6) include those shown below.
That is, 2,4-tolylene diisocyanate, dimer of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate Aromatic diisocyanate compounds such as 1,5-naphthylene diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate;
Aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate and the like;
Alicyclic diisocyanate compounds such as isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate, 1,3- (isocyanatomethyl) cyclohexane;
And a diisocyanate compound which is a reaction product of a diol and a diisocyanate such as an adduct of 1 mol of 1,3-butylene glycol and 2 mol of tolylene diisocyanate.

2) Examples of the diol compound diol compound include a polyether diol compound, a polyester diol compound, and a polycarbonate diol compound.

  Examples of the polyether diol compound include compounds represented by the following formulas (7), (8), (9), (10) and (11), and random copolymerization of ethylene oxide and propylene oxide having a hydroxyl group at the terminal. Coalescence is mentioned.

In formulas (7) to (11), R ¹⁴ represents a hydrogen atom or a methyl group, and X ¹ represents the following group. Moreover, a, b, c, d, e, f, and g each represent an integer of 2 or more, and preferably an integer of 2 to 100.

Specific examples of the polyether diol compound represented by the above formulas (7) and (8) include the following.
That is, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, di-1,2-propylene glycol, tri-1,2-propylene glycol, tetra-1, 2-propylene glycol, hexa-1,2-propylene glycol, di-1,3-propylene glycol, tri-1,3-propylene glycol, tetra-1,3-propylene glycol, di-1,3-butylene glycol, Tri-1,3-butylene glycol, hexa-1,3-butylene glycol, polyethylene glycol having a weight average molecular weight of 1000, polyethylene glycol having a weight average molecular weight of 1500, poly having a weight average molecular weight of 2000 Tylene glycol, polyethylene glycol with a weight average molecular weight of 3000, polyethylene glycol with a weight average molecular weight of 7500, polypropylene glycol with a weight average molecular weight of 400, polypropylene glycol with a weight average molecular weight of 700, polypropylene glycol with a weight average molecular weight of 1000, polypropylene glycol with a weight average molecular weight of 2000 , Polypropylene glycol having a weight average molecular weight of 3000, polypropylene glycol having a weight average molecular weight of 4000, and the like.

Specific examples of the polyether diol compound represented by the formula (9) include those shown below.
That is, Sanyo Chemical Industries, Ltd. (trade name) PTMG650, PTMG1000, PTMG2000, PTMG3000, and the like.

Specific examples of the polyether diol compound represented by the formula (10) include those shown below.
That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole PE-61, New Pole PE-62, New Pole PE-64, New Pole PE-68, New Pole PE-71, New Pole PE-74, New Pole PE-75, New Pole PE-78, New Pole PE-108, New Pole PE-128, New Pole PE-61, and the like.

Specific examples of the polyether diol compound represented by the formula (11) include those shown below.
That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole BPE-20, New Pole BPE-20F, New Pole BPE-20NK, New Pole BPE-20T, New Pole BPE-20G, New Pole BPE-40, New Pole BPE-60, New Pole BPE-100, New Pole BPE-180, New Pole BPE-2P, New Pole BPE-23P, New Pole BPE-3P, New Pole BPE-5P, and the like.

Specific examples of the random copolymer of ethylene oxide and propylene oxide having a hydroxyl group at the terminal include the following.
That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole 50HB-100, New Pole 50HB-260, New Pole 50HB-400, New Pole 50HB-660, New Pole 50HB-2000, New Pole 50HB-5100, etc. It is.

  Examples of the polyester diol compound include compounds represented by formulas (12) and (13).

In formulas (12) and (13), L ² , L ³ and L ⁴ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group, and L ⁵ represents a divalent aliphatic carbonization. Represents a hydrogen group. Preferably, L ^{2 to} L ⁴ each represent an alkylene group, an alkenylene group, an alkynylene group, or an arylene group, and L ⁵ represents an alkylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ^{2 to} L ⁵ . n1 and n2 are each an integer of 2 or more, preferably an integer of 2 to 100.
As the polycarbonate diol compound, there is a compound represented by the formula (14).

In the formula (14), L ⁶ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group. Preferably, L ⁶ represents an alkylene group, an alkenylene group, an alkynylene group or an arylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ⁶ . n3 is an integer of 2 or more, and preferably represents an integer of 2 to 100.

  Specific examples of the diol compound represented by the above formula (12), (13) or (14) include (Exemplary Compound No. 1) to (Exemplary Compound No. 18) shown below. N in the specific examples represents an integer of 2 or more.

  Moreover, in the synthesis | combination of a polyurethane resin, the diol compound which has a substituent which does not react with an isocyanate group other than the said diol compound can also be used together. Examples of such diol compounds include those shown below.

^{HO-L 7 -O-CO-} L 8 -CO-O-L 7 -OH (15)
^{HO-L 8 -CO-O-} L 7 -OH (16)

In the formulas (15) and (16), L ⁷ and L ⁸ may be the same or different, and each may have a substituent (for example, an alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, —F, — And a divalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group, which may have a halogen atom such as Cl, -Br, and -I. If necessary, L ⁷ and L ⁸ may have another functional group that does not react with an isocyanate group, such as a carbonyl group, an ester group, a urethane group, an amide group, or a ureido group. Note that L ⁷ and L ⁸ may form a ring.

Further, the binder can be provided with a crosslinking property in order to improve the film strength of the image area.
In order to impart crosslinkability to the binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization or may be introduced by a polymer reaction.

Here, the crosslinkable group is a group that crosslinks the binder in the course of radical polymerization reaction that occurs in the photosensitive layer when the lithographic printing plate precursor is exposed. Although it will not specifically limit if it is a group of such a function, For example, an ethylenically unsaturated bond group, an amino group, an epoxy group etc. are mentioned as a functional group which can be addition-polymerized. Moreover, the functional group which can become a radical by light irradiation may be sufficient, and as such a crosslinkable group, a thiol group, a halogen group, an onium salt structure etc. are mentioned, for example. Especially, an ethylenically unsaturated bond group is preferable and the functional group represented by the following general formula (1)-(3) is especially preferable.

In the general formula (1), R ^{1 to} R ³ each independently represents a hydrogen atom or a monovalent organic group, and R ¹ is preferably a hydrogen atom or an alkyl which may have a substituent. A hydrogen atom or a methyl group is preferable because of high radical reactivity. R ² and R ³ are each independently a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an optionally substituted alkyl group, or a substituted group. An aryl group which may have a group, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, and a substituent An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

X represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, wherein R ¹² represents a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include an alkyl group which may have a substituent. R ¹² is preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group because of high radical reactivity.

  Here, examples of the substituent that can be introduced include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, an alkylamino group, an arylamino group, a carboxyl group, an alkoxycarbonyl group, A sulfo group, a nitro group, a cyano group, an amide group, an alkylsulfonyl group, an arylsulfonyl group and the like can be mentioned.

In the general formula (2), R ^{4 to} R ⁸ each independently represents a hydrogen atom or a monovalent organic group, and R ^{4 to} R ⁸ are preferably a hydrogen atom, a halogen atom, an amino group, or a dialkyl. Amino group, carboxyl group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, alkyl group which may have a substituent, aryl group which may have a substituent, alkoxy which may have a substituent A group, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, Examples include an arylsulfonyl group which may have a substituent. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group which may have a substituent, and an aryl which may have a substituent The ru group is preferred.

Examples of the substituent that can be introduced are the same as those in the general formula (1). Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —. R ¹² has the same meaning as R ¹² in general formula (1), and preferred examples are also the same.

In the general formula (3), R ⁹ represents a hydrogen atom or a monovalent organic group, and preferably includes a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom A methyl group is preferable because of high radical reactivity. R ¹⁰ and R ¹¹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or an alkyl group which may have a substituent. An aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, An arylamino group which may have, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, etc. are mentioned, among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

Here, examples of the substituent that can be introduced are the same as those in the general formula (1). Further, Z is an oxygen atom, a sulfur atom, -N (R ¹³⁾ -, or a phenylene group which may have a substituent. Examples of R ¹³ include an alkyl group which may have a substituent. Among them, a methyl group, an ethyl group, and an isopropyl group are preferable because of high radical reactivity.

  Among these, a vinyl copolymer having a crosslinkable group in the side chain and a polyurethane resin having a crosslinkable group in the side chain are more preferable.

In the binder having crosslinkability, for example, free radicals (polymerization initiating radicals or growth radicals in the polymerization process of the polymerizable compound) are added to the crosslinkable functional group, and the binder is directly or via a polymerization chain of the polymerizable compound. Then, addition polymerization is performed, and a crosslink is formed between the binder molecules to be cured. Alternatively, atoms in the binder (for example, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are extracted by free radicals to form polymer radicals that are bonded to each other, thereby causing cross-linking between the binder molecules. Forms and cures.
The content of the crosslinkable group in the binder (content of unsaturated double bond capable of radical polymerization by iodometric titration) is preferably 0.1 to 10.0 mmol, more preferably 1.0 to 7 per gram of binder. 0.0 mmol, most preferably 2.0-5.5 mmol.
The glass transition temperature (Tg) of the binder according to the present invention is preferably 0 to 150 ° C, more preferably 20 to 120 ° C, and particularly preferably 30 to 100 ° C. When the glass transition temperature is less than 0 ° C., the printing durability may be deteriorated, and when the glass transition temperature exceeds 150 ° C., the developability may be deteriorated.

The binder preferably has a mass average molecular weight of 5,000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1,000 or more is preferable.
More preferably, it is ˜250,000. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The binder may be any of random polymer, block polymer, graft polymer and the like.
A binder may be used independently or may mix and use 2 or more types.
The content of the binder is preferably from 5 to 75 mass%, more preferably from 10 to 60 mass%, more preferably from 20 to 50 mass%, based on the total solid content of the photosensitive layer, from the viewpoints of good image area strength and image formability. % Is particularly preferred.

<Polymerization initiator>
As a polymerization initiator used in the photosensitive layer of the present invention, a trihalomethyl compound, a carbonyl compound, an organic peroxide, an azo compound, an azide compound, a metallocene compound, a hexaarylbiimidazole compound, an organic boron compound, a disulfone compound, Examples include oxime ester compounds and onium salt compounds. Among these, at least one selected from the group consisting of a hexaarylbiimidazole compound, an onium salt compound, a trihalomethyl compound, and a metallocene compound is preferable, and a hexaarylbiimidazole compound is particularly preferable.

  Examples of the hexaarylbiimidazole compound include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4 ′, 5. 5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p-dichlorophenyl)- 4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2,2 '-Bis (o, o'-dichlorophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4 ', 5,5'- Tet Phenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-trifluorophenyl) -4,4' , 5,5'-tetraphenylbiimidazole and the like.

  The trihalomethyl compound is preferably trihalomethyl-s-triazine, 2,4,6-tris (trichloromethyl) -s-triazine, 2-methoxy-4,6-bis (trichloromethyl) -s-triazine, 2- Trimethyl compounds described in JP-A-58-29803 such as amino-4,6-bis (trichloromethyl) -s-triazine, 2- (P-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine and the like. Examples thereof include s-triazine derivatives having a halogen-substituted methyl group.

  Examples of the onium salt compound include onium salts represented by the following general formula (III).

In general formula (III), R ¹¹ , R ¹² and R ¹³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, and 12 carbon atoms.
And an alkoxy group having 12 or less carbon atoms or an aryloxy group having 12 or less carbon atoms.
Z ⁻ represents a counter ion selected from the group consisting of halogen ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, carboxylate ion, and sulfonate ion, preferably perchlorate ion, hexa Fluorophosphate ions, carboxylate ions, and aryl sulfonate ions.

As the titanocene compound, for example, known compounds described in JP-A Nos. 59-152396 and 61-151197 can be appropriately selected and used.
Specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5, 6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2, 4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4-difluoro Phen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2, 3, 5, 6 Tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis [2,6-difluoro-3- ( Pyr-1-yl) phenyl] titanium and the like.

  Examples of the carbonyl compound include benzophenone, Michler ketone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophenone and other benzophenone derivatives, 2,2-dimethoxy- 2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1-methylethyl- (p-isopropylphenyl) ketone, 1- Hydroxy-1- (p-dodecylphenyl) ketone, 2-methyl- (4 ′-(methylthio) phenyl) -2-morpholino-1-propanone, 1,1,1-trichloromethyl- (p-butylphenyl) Acetophenone derivatives such as ketones, thioxanthone derivatives such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, p- Examples thereof include benzoic acid ester derivatives such as ethyl dimethylaminobenzoate and ethyl p-diethylaminobenzoate.

  Examples of the oxime ester compound include JCS Perkin II (1979) 1653-1660), JCSPerkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, and JP-A 2000-66385. And compounds described in JP 2000-80068 A.

In the present invention, the polymerization initiator is suitably used alone or in combination of two or more.
The amount of the polymerization initiator used in the photosensitive layer in the present invention is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, and still more preferably 1. It is 0 mass%-10 mass%.

<Sensitizing dye>
The photosensitive layer of the present invention can contain a sensitizing dye corresponding to the wavelength of the exposure light source.
First, a sensitizing dye having a maximum absorption in the wavelength region of 350 to 450 nm will be described. Examples of such a sensitizing dye include merocyanine dyes represented by the following general formula (I), benzopyrans and coumarins represented by the following general formula (II), and fragrances represented by the following general formula (III). And anthracenes represented by the following general formula (IV).

(In the formula, A represents an S atom or NR ₆ , R ₆ represents a hydrogen atom or a monovalent nonmetallic atomic group, Y represents a basic nucleus of the dye in combination with the adjacent A and the adjacent carbon atom. X ₁ and X ₂ each independently represents a hydrogen atom or a monovalent nonmetallic atomic group, and X ₁ and X ₂ are bonded to each other to form an acidic nucleus of the dye. May be.)

(In the formula, = Z represents a carbonyl group, a thiocarbonyl group, an imino group or an alkylidene group represented by the partial structural formula (1 ′), and X ₁ and X ₂ have the same meanings as in the general formula (I). R _{7 to} R ₁₂ each independently represents a hydrogen atom or a monovalent nonmetallic atomic group.)

(In the formula, Ar ₃ represents an aromatic group or a heteroaromatic group which may have a substituent,
R ₁₃ represents a hydrogen atom or a monovalent nonmetallic atomic group. Preferred R ₁₃ is an aromatic group or a heteroaromatic group. Ar ₃ and R ₁₃ may be bonded to each other to form a ring. )

(In the formula, X ₃ , X ₄ and R _{14 to} R ₂₁ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and preferred X ₃ and X ₄ are electron donors having a negative Hammett's substituent constant. Sex group.)

Preferred examples of the monovalent nonmetallic atomic group represented by X ₁ to X ₄ and R ₆ to R ₂₁ in the general formulas (I) to (IV) include an alkyl group (for example, a methyl group, an ethyl group, Propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s- Butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group, 2-norbornyl group, chloromethyl group, bromomethyl group 2-chloroethyl group, trifluoromethyl group, methoxymethyl group, methoxyethoxyethyl group, Ryloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N -Phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl Group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- Sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N- Methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolyl Phosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonatooxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group Cinnamyl group, Ryl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, etc.), aryl group (for example, phenyl group) , Biphenyl group, naphthyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group , Benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxyca Bonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, phosphonatophenyl group, etc.), heteroaryl group (for example, thiophene, thiathrene, furan) , Pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indoyl, indazole, purine, quinolidine, isoquinoline, phthalazine, naphthyridine , Quinazoline, Cinoline, Pteridine, Carbazole, Carboline, Phenanthrin, Acridine, Perimidine, Phenanthroline, Phthalazine, Phenalzazine, Phenoxazine , Furazane, phenoxazine, etc.), alkenyl group (for example, vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group, etc.), alkynyl group (for example, ethynyl group, 1- Propynyl group, 1-butynyl group, trimethylsilylethynyl group, etc.), halogen atom (-F, -Br, -Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio Group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, Carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino Group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl -N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl-N-arylureido group, N ', N'-dialkyl- N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-a -N-alkylureido group, N'-aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N '-Alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino Group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, Aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo Group (—SO ₃ H) and its conjugate base group (hereinafter referred to as sulfonate group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group Group, N-arylsulfamo Le group, N, N- diaryl sulfamoyl group, N- alkyl -N- arylsulfamoyl group, a phosphono group (-PO ₃ H ₂₎ and its conjugated base group (hereinafter referred to as phosphonato group), dialkyl Phono group (—PO ₃ (alkyl) ₂ ), diaryl phosphono group (—PO ₃ (aryl) ₂ ), alkylaryl phosphono group (—PO ₃ (alkyl) (aryl)), monoalkyl phosphono group (— PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkyl phosphonate group), monoaryl phosphono group (—PO ₃ H (ary)) and its conjugate base group (hereinafter referred to as aryl phosphonate group) referred), phosphonooxy group (-OPO ₃ H ₂₎ and its conjugated base group (hereinafter referred to as phosphonophenyl group), Jiarukiruho Fonookishi group _{(-OPO 3 (alkyl) 2)} , diaryl phosphonooxy group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphonooxy group _{(-OPO 3 (alkyl) (aryl} )), monoalkyl phosphonooxy oxy Group (—OPO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonatooxy group), monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group (hereinafter, An arylphosphonatooxy group), a cyano group, a nitro group, and the like. In general formulas (I) to (IV), X ₁ to X ₄ and R ₆ to R ₂₁ are particularly preferably a hydrogen atom, an alkyl group, an aryl group, a halogen atom, an alkoxy group, or an acyl group.

  Examples of the basic nucleus of the dye formed by Y in the general formula (I) together with the adjacent A and adjacent carbon atom include a 5, 6 or 7-membered nitrogen-containing or sulfur-containing heterocyclic ring, A 5- or 6-membered heterocyclic ring is preferable.

Examples of nitrogen-containing heterocycles include L.I. G. Brooker et al. , J .; Am. Chem. Soc. 73, 5326-5358 (1951) and those known to constitute basic nuclei in the merocyanine dyes described in References can be suitably used. Specific examples include thiazoles (for example, thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4,5- Di (p-methoxyphenylthiazole), 4- (2-thienyl) thiazole, etc.), benzothiazoles (for example, benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 7- Chlorobenzothiazole, 4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 4-phenylbenzothiazole, 5-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzo Cheer , 6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-di Oxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 6-dimethylaminobenzothiazole, 5-ethoxycarbonylbenzothiazole, etc.), naphthothiazoles (for example, naphtho [1,2] thiazole, naphtho [2 , 1] thiazole, 5-methoxynaphtho [2,1] thiazole, 5-ethoxynaphtho [2,1] thiazole, 8-methoxynaphtho [1,2] thiazole, 7-methoxynaphtho [1,2] thiazole, etc.) , Chianafuteno 7 ′, 6 ′, 4,5-thiazole (for example, 4′-methoxythianaphtheno-7 ′, 6 ′, 4,5-thiazole, etc.), oxazole (for example, 4-methyloxazole, 5-methyloxazole) 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5-phenyloxazole, etc.), benzoxazoles (benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole) , 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 6-methoxybenzoxazole, 5-methoxybenzoxazole, 4-ethoxybenzoxazole, 5-chloro Benzoki Sol, 6-methoxybenzoxazole, 5-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.), naphthoxazoles (eg, naphtho [1,2] oxazole, naphtho [2,1] oxazole, etc.), selenazoles (eg, , 4-methylselenazole, 4-phenylselenazole, etc.), benzoselenazoles (for example, benzoselenazole, 5-chlorobenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole, tetrahydrobenzoselena) Sol etc.), naphthoselenazoles (eg naphtho [1,2] selenazole, naphtho [2,1] selenazole etc.), thiazolines (eg thiazoline, 4-methylthiazoline etc.), quinolines (eg quinoline, 3-methylquino , 5-methylquinoline, 7-methylquinoline, 8-methylquinoline, 6-chloroquinoline, 8-chloroquinoline, 6-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline, etc.), isoquinoline (Eg, isoquinoline, 3,4-dihydroisoquinoline, etc.), benzimidazoles (eg, 1,3-diethylbenzimidazole, 1-ethyl-3-phenylbenzimidazole, etc.), 3,3-dialkylindolenines (For example, 3,3-dimethylindolenine, 3,3,5, -trimethylindolenine, 3,3,7, -trimethylindolenine, etc.), pyridines (for example, pyridine, 5-methylpyridine, etc.) and the like. Can be mentioned.

Examples of the sulfur-containing heterocycle include a dithiol partial structure in dyes described in JP-A-3-296759.
Specific examples include benzodithiols (for example, benzodithiol, 5-t-butylbenzodithiol, 5-methylbenzodithiol, etc.), naphthodithiols (for example, naphtho [1,2] dithiol, naphtho [2,1] Dithiol etc.), dithiols (for example, 4,5-dimethyldithiols, 4-phenyldithiols, 4-methoxycarbonyldithiols, 4,5-dimethoxycarbonylbenzodithiols, 4,5-ditrifluoromethyldithiol, 4 , 5-dicyanodithiol, 4-methoxycarbonylmethyldithiol, 4-carboxymethyldithiol and the like.

  As mentioned above, for the sake of convenience, the description used in the description of the heterocyclic ring has conventionally used the name of the heterocyclic mother skeleton, but when forming the basic skeleton partial structure of the sensitizing dye, for example, in the case of the benzothiazole skeleton It is introduced in the form of an alkylidene-type substituent with one degree of unsaturation, such as a 3-substituted-2 (3H) -benzothiazolidene group.

  Of the sensitizing dyes having an absorption maximum in the wavelength range of 350 nm to 450 nm, a dye more preferable from the viewpoint of high sensitivity is a dye represented by the following general formula (V).

(In General Formula (V), A represents an aromatic ring group which may have a substituent or a heterocyclic group which may have a substituent, and X represents an oxygen atom, a sulfur atom or N—R ₃ . R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom or a monovalent nonmetallic atomic group, and A and R ₁ or R ₂ and R ₃ are bonded to each other to form an aliphatic group or An aromatic ring may be formed.)

The general formula (V) will be described in more detail. R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, substituted or unsubstituted An aryl group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a hydroxyl group, and a halogen atom.

Preferable examples of R ₁ , R ₂ and R ₃ will be specifically described. Examples of preferable alkyl groups include linear, branched, and cyclic alkyl groups having 1 to 20 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, Butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s-butyl, Examples thereof include t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group and 2-norbornyl group. Of these, linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 3 to 12 carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are more preferable.

As the substituent of the substituted alkyl group, a monovalent nonmetallic atomic group is used, and preferred examples include a halogen atom (—F, —Br, —Cl, —I), a hydroxyl group, an alkoxy group, an aryloxy group, Mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N- Alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl -N-arylcarbamoyloxy group, alkylsulfoxy group, aryls Hoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ', N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl- N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl- N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylurei group Group, N′-alkyl-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N -Alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-arylN-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group, alkoxy Carbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkyl A sulfinyl group, Arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group (hereinafter referred to as sulfonate group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkyls Rufinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkyl Sulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group (-PO ₃ H ₂₎ and its conjugated base group (hereinafter referred to as phosphonato group , Dialkyl phosphono group _{(-PO 3 (alkyl) 2)} , diaryl phosphono group _{(-PO 3 (aryl) 2)} , alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )), monoalkyl phosphono Group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonate group), monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as arylphosphine group). A phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as a phosphonatooxy group), a dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), a diarylphosphine Fonookishi group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphonooxy group (-OPO ₃ (alkyl (Aryl)), monoalkyl phosphonooxy group (-OPO ₃ H (alkyl)) and its conjugated base group (hereinafter referred to as alkyl phosphonophenyl group), monoaryl phosphonooxy group (-OPO ₃ H (aryl )) And conjugated base groups thereof (hereinafter referred to as arylphosphonatooxy groups), cyano groups, nitro groups, aryl groups, heteroaryl groups, alkenyl groups, and alkynyl groups.

  Among these substituents, more preferred are halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, N, N-dialkyls. Amino group, acyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group N-arylsulfamoy Group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonate group, dialkyl phosphono group, diaryl phosphono group, monoalkyl phosphono group, alkyl phosphonate group, monoaryl phosphono group, aryl phosphonate group Group, phosphonooxy group, phosphonatooxy group, aryl group, and alkenyl group.

  Specific examples of the alkyl group in these substituents include the above-described alkyl groups, and specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a mesityl group, and a cumenyl group. , Chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylamino Phenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group Cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl phenyl group, phosphonophenyl phenyl group and the like.

  On the other hand, examples of the alkylene group in the substituted alkyl group include a divalent organic residue obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. Preferred examples include linear alkylene groups having 1 to 12 carbon atoms, branched alkylene groups having 3 to 12 carbon atoms, and cyclic alkylene groups having 5 to 10 carbon atoms.

Specific examples of preferred substituted alkyl groups as R ₁ , R ₂ and R ₃ obtained by combining the above substituents with an alkylene group include chloromethyl, bromomethyl, 2-chloroethyl, trifluoromethyl, methoxy Methyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N -Cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycal Bonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl- N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonate Til group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p -Methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, etc. Can be mentioned.

Preferred aromatic heterocyclic groups as R ₁ , R ₂ and R ₃ include groups derived from monocyclic or polycyclic aromatic rings containing at least one of nitrogen, oxygen and sulfur atoms, and particularly Examples of preferred aromatic heterocycles include, for example, thiophene, thiathrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, Indolizine, indoyl, indazole, purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanthroline, phthalazine, phenazazine, phenoxadi , Furazane, phenoxazine, and the like, and these may be further benzo-fused or may have a substituent.

Examples of preferable alkenyl groups as R ₁ , R ₂ and R ₃ include vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group and the like, and alkynyl Examples of the group include ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group and the like. Examples of G ₁ in the acyl group (G ₁ CO—) include hydrogen and the above alkyl groups and aryl groups.

Specific examples of preferred aryl groups as R ₁ , R ₂ and R ₃ include those in which 1 to 3 benzene rings form a condensed ring, and those in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable. .

Specific examples of preferred substituted aryl groups as R ₁ , R _2, and R ₃ include those having a monovalent non-metallic atomic group as a substituent on the ring-forming carbon atom of the aforementioned aryl group. Examples of preferred substituents include the alkyl groups, substituted alkyl groups, and those previously shown as substituents in the substituted alkyl group. Preferred examples of such a substituted aryl group include a biphenyl group, a tolyl group, a xylyl group, a mesityl group, a cumenyl group, a chlorophenyl group, a bromophenyl group, a fluorophenyl group, a chloromethylphenyl group, and a trifluoromethylphenyl group. Hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group, methylthiophenyl group, tolylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, acetyloxyphenyl group, Benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group, acetylaminophenyl group, N-methylbenzoylaminophenyl group, carbo Cyphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-methylcarbamoylphenyl group, N, N-dipropylcarbamoylphenyl group, N- (methoxyphenyl) carbamoylphenyl group N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, phosphonophenyl group, phosphonatophenyl group, diethylphosphonophenyl group, diphenylphosphono Enyl group, methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonatophenyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallylphenyl group, 2- Examples thereof include a methylpropenylphenyl group, a 2-propynylphenyl group, a 2-butynylphenyl group, and a 3-butynylphenyl group.

Next, A in the general formula (V) will be described. A represents an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent, and an aromatic ring which may have a substituent or a heterocyclic ring which may have a substituent Specific examples thereof include those similar to those described as the aryl group and the aromatic heterocyclic group in R ₁ , R ₂ and R ₃ in the general formula (V).

  The sensitizing dye represented by the general formula (V) of the present invention is a condensation of an acidic nucleus having an acidic nucleus or an active methylene group as shown above with a substituted or unsubstituted aromatic ring or heterocyclic ring. Although obtained by reaction, these can be synthesized with reference to Japanese Examined Patent Publication No. 59-28329.

  Preferred specific examples (D1) to (D75) of the compound represented by formula (V) are shown below. In addition, the isomer by the double bond connecting the acidic nucleus and the basic nucleus is not limited to any isomer.

Details of usage, such as which of these sensitizing dyes to use, whether to use alone or in combination of two or more, and the amount to be added, are appropriately set according to the performance design of the final lithographic printing plate precursor it can.
For example, the compatibility in the composition constituting the photosensitive layer can be increased by using two or more sensitizing dyes in combination. In selecting the sensitizing dye, in addition to the photosensitivity, the molar extinction coefficient at the emission wavelength of the light source used is an important factor. By using a dye having a large molar extinction coefficient, the amount of the dye added can be made relatively small, which is economical and advantageous from the viewpoint of film physical properties of the photosensitive layer when used in a lithographic printing plate precursor. is there. Since the photosensitivity and resolution of the photosensitive layer and the physical properties of the exposure film are greatly affected by the absorbance at the light source wavelength, the addition amount of the sensitizing dye is appropriately selected in consideration of these.

However, for example, for the purpose of curing a thick film having a thickness of 5 μm or more, the degree of curing may be increased by lower absorbance. When used as a lithographic printing plate precursor used in a relatively thin film thickness, the addition amount of the sensitizing dye is such that the absorbance of the photosensitive layer of the present invention is in the range of 0.1 to 1.5, preferably from 0.25. It is preferable to set so as to be in the range of 1. Usually, the addition amount of the sensitizing dye is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and most preferably 0.2 to 100 parts by mass with respect to 100 parts by mass of the total solid content of the photosensitive layer. The range is 10 parts by mass.

<Co-sensitizer>
In the present invention, a co-sensitizer can be used. The co-sensitizer is an additive that can further improve the sensitivity of the photosensitive layer when added to the photosensitive layer. The mechanism of action is not clear, but many are thought to be based on the following chemical process. That is, a photoreaction initiated by light absorption of the above-described photopolymerization initiation system, and various intermediate active species (radicals, peroxides, oxidizing agents, reducing agents, etc.) generated in the course of the subsequent addition polymerization reaction, It is presumed that the co-sensitizer reacts to generate a new active radical. The co-sensitizers are broadly (a) those that can be reduced to generate active radicals, (b) those that can be oxidized to generate active radicals, and (c) more active by reacting with less active radicals. However, there are many cases where there is no general rule as to which individual compounds belong to them.

(A) Compound that is reduced to produce an active radical Compound having a carbon-halogen bond: It is considered that an active radical is generated by reductive cleavage of the carbon-halogen bond. Specifically, for example, trihalomethyl-s-triazines and trihalomethyloxadiazoles can be preferably used.
Compound having nitrogen-nitrogen bond: It is considered that the nitrogen-nitrogen bond is reductively cleaved to generate an active radical. Specifically, hexaarylbiimidazoles and the like are preferably used.
Compound having oxygen-oxygen bond: It is considered that the oxygen-oxygen bond is reductively cleaved to generate an active radical. Specifically, for example, organic peroxides are preferably used.
Onium compounds: It is considered that carbon-hetero bonds and oxygen-nitrogen bonds are reductively cleaved to generate active radicals. Specifically, for example, diaryliodonium salts, triarylsulfonium salts, N-alkoxypyridinium (azinium) salts and the like are preferably used.

(B) Compound which is oxidized to generate an active radical Alkylate complex: It is considered that a carbon-hetero bond is oxidatively cleaved to generate an active radical. Specifically, for example, triarylalkyl borates are preferably used.
Alkylamine compound: It is considered that the C—X bond on carbon adjacent to nitrogen is cleaved by oxidation to generate an active radical. X is preferably a hydrogen atom, a carboxyl group, a trimethylsilyl group, a benzyl group or the like. Specific examples include ethanolamines, N-phenylglycines, N-trimethylsilylmethylanilines, and the like.
Sulfur-containing and tin-containing compounds: Compounds in which the nitrogen atoms of the above-described amines are replaced with sulfur atoms and tin atoms can generate active radicals by the same action. Further, a compound having an SS bond is also known to be sensitized by SS cleavage.
α-Substituted methylcarbonyl compound: An active radical can be generated by oxidative cleavage of the carbonyl-α carbon bond. Moreover, what converted carbonyl into the oxime ether also shows the same effect | action. Specifically, 2-alkyl-1- [4- (alkylthio) phenyl] -2-morpholinopropanone-1 and these and hydroxyamines were reacted, and then N-OH was etherified. Examples include oxime ethers and N-OH esterified oxime esters.
Sulfinic acid salts: An active radical can be reductively generated. Specific examples include sodium arylsulfinate.

(C) A compound that reacts with a radical to be converted into a highly active radical or acts as a chain transfer agent.
As a compound that reacts with a radical to convert to a highly active radical or acts as a chain transfer agent, for example, a compound group having SH, PH, SiH, and GeH in the molecule is used. These can generate hydrogen by donating hydrogen to a low-activity radical species to generate radicals, or after being oxidized and deprotonated. Specifically, 2-mercaptobenzimidazoles etc. are mentioned, for example.

More specific examples of these co-sensitizers include compounds described as additives for the purpose of improving sensitivity in JP-A-9-236913.
Some examples are shown below, but the present invention is not limited thereto.

  These co-sensitizers can also be subjected to various chemical modifications for improving the characteristics of the photosensitive layer of the lithographic printing plate precursor. For example, bonding with sensitizing dyes, polymerization initiators, polymerizable compounds and other radical generating parts, introduction of hydrophilic sites, compatibility improvement, introduction of substituents to suppress crystal precipitation, introduction of substituents to improve adhesion A method such as polymerization can be used. These co-sensitizers can be used alone or in combination of two or more. The amount used is preferably in the range of 0.05 to 100 parts by weight, more preferably 1 to 80 parts by weight, and even more preferably 3 to 50 parts by weight with respect to 100 parts by weight of the polymerizable compound.

<Microcapsule>
In the present invention, as a method for incorporating the above-mentioned photosensitive layer constituents and other constituents described later into the photosensitive layer, for example, as described in JP-A Nos. 2001-277740 and 2001-277742, the constituents are described. Part or all of the components can be encapsulated in microcapsules and added to the photosensitive layer. In that case, each component can be contained in any ratio in and out of the microcapsule.

As a method for microencapsulating the photosensitive layer constituent components, known methods can be applied. For example, as a method for producing a microcapsule, a method using coacervation as described in US Pat. Nos. 2,800,047 and 2,800,498, US Pat. No. 3,287,715 is disclosed.
Method of interfacial polymerization found in each specification of No. 4, Japanese Patent Publication Nos. 38-19574 and 42-446, and precipitation of polymers found in US Pat. Nos. 3,418,250 and 3,660,304 A method using an isocyanate polyol wall material found in US Pat. No. 3,796,669, a method using an isocyanate wall material found in US Pat. No. 3,914,511, US Pat. Nos. 4,001,140, 4,087,376, US Pat. No. 4,089,802, a method using a urea-formaldehyde-based or urea-formaldehyde-resorcinol-based wall forming material, a wall material such as melamine-formaldehyde resin, hydroxycellulose, etc. as shown in US Pat. No. 4,025,445. Method used, JP-B 36-916 No. 51-9079, in-situ method by monomer polymerization, British Patent No. 930422, US Pat. No. 3,111,407 Spray Drying Method, British Patent Nos. However, the present invention is not limited thereto.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with 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. Moreover, you may introduce | transduce into the microcapsule wall the compound which has crosslinkable functional groups, such as an ethylenically unsaturated bond which can be introduce | transduced into said water-insoluble polymer.

  The average particle size of the microcapsules is preferably 0.01 to 3.0 μm, more preferably 0.05 to 2.0 μm, and particularly preferably 0.10 to 1.0 μm. Within this range, good resolution and stability over time can be obtained.

<Other photosensitive layer components>
The photosensitive layer of the present invention can further contain various additives as required. These will be described below.

<Surfactant>
In the present invention, it is preferable to use a surfactant in the photosensitive layer in order to promote developability and improve the coated surface state. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorosurfactants.

  The nonionic surfactant used for this invention is not specifically limited, A conventionally well-known thing can be used. For example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol Fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, Polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N N- bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid ester, trialkylamine oxide, polyethylene glycol, copolymers of polyethylene glycol and polypropylene glycol.

The anionic surfactant used in the present invention is not particularly limited, and conventionally known anionic surfactants can be used. For example, fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinate esters, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy poly Oxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, fatty acid alkyl esters Sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alcohol Ruphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene / maleic anhydride Examples thereof include partial saponification products of polymers, partial saponification products of olefin / maleic anhydride copolymers, and naphthalene sulfonate formalin condensates.

The cationic surfactant used in the present invention is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.
The amphoteric surfactant used in the present invention is not particularly limited, and conventionally known amphoteric surfactants can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric acid esters, and imidazolines.

  Of the above surfactants, the term “polyoxyethylene” can be read as “polyoxyalkylene” such as polyoxymethylene, polyoxypropylene, polyoxybutylene, etc. These surfactants can also be used.

  More preferable surfactants include fluorine-based surfactants containing a perfluoroalkyl group in the molecule. Examples of such fluorosurfactants include anionic types such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl phosphates; amphoteric types such as perfluoroalkyl betaines; Cation type such as trimethylammonium salt; perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, perfluoroalkyl Nonionic types such as an oligomer containing a group, a hydrophilic group and a lipophilic group, and a urethane containing a perfluoroalkyl group and a lipophilic group. Also preferred are the fluorosurfactants described in JP-A-62-170950, JP-A-62-226143 and JP-A-60-168144.

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 7% by mass with respect to the total solid content of the photosensitive layer.

<Hydrophilic polymer>
In the present invention, a hydrophilic polymer can be contained in order to improve the developability and the dispersion stability of the microcapsules.
Examples of the hydrophilic polymer include hydroxy group, carboxyl group, carboxylate group, hydroxyethyl group, polyoxyethyl group, hydroxypropyl group, polyoxypropyl group, amino group, aminoethyl group, aminopropyl group, ammonium group, Preferred are those having a hydrophilic group such as an amide group, carboxymethyl group, sulfonic acid group, and phosphoric acid group.

Specific examples include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids and their salts, 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 Polymers and copolymers, homopolymers and copolymers of hydroxybutyl acrylate Polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide homopolymers and copolymers having a hydrolysis degree of 60 mol% or more, preferably 80 mol% or more , Methacrylamide homopolymers and polymers, N-methylolacrylamide homopolymers and copolymers, polyvinylpyrrolidone, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, etc. Is mentioned.

The hydrophilic polymer preferably has a mass average molecular weight of 5000 or more, more preferably 10,000 to 300,000. The hydrophilic polymer may be any of a random polymer, a block polymer, a graft polymer, and the like.
The content of the hydrophilic polymer in the photosensitive layer is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total solid content of the photosensitive layer.

<Colorant>
In the present invention, a dye having a large absorption in the visible light region can be used as an image colorant. 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 (orientated chemistry) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc. And dyes described in Japanese Patent No. 293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, etc. can be suitably used.

  These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. The amount added is preferably 0.01 to 10% by mass with respect to the total solid content of the photosensitive layer.

<Bakeout agent>
In the photosensitive layer of the present invention, a compound that changes color by an acid or a radical can be added in order to form a printout image. As such a compound, for example, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used.

  Specific examples include brilliant green, ethyl violet, methyl green, crystal violet, basic fuchsin, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange, paramethyl red, Congo Fred, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A, Methyl Violet, Malachide Green, Parafuchsin, Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.], Oil Blue # 603 [Orient Chemical Kogyo Co., Ltd.], Oil Pink # 312 [Orient Chemical Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Gaku Kogyo Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.], Oil Red RR [Orient Chemical Co., Ltd.], Oil Green # 502 [Orient Chemical Co., Ltd.], Spiron Red BEH Special [made by Hodogaya Chemical Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p- Diethylaminophenyliminonaphthoquinone, 2-carboxystearylamino-4-pN, N-bis (hydroxyethyl) amino-phenyliminonaphthoquinone, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4- - dyes and p of diethylamino phenyl imino-5-pyrazolone, p ', p "- hexamethyl triamnotriphenylmethane (leuco crystal violet), and a leuco dye such as Pergascript Blue SRB (manufactured by Ciba-Geigy).

  In addition to the above, a leuco dye known as a material for thermal paper or pressure-sensitive paper is also suitable. Specific examples include crystal violet lactone, malachite green lactone, benzoylleucomethylene blue, 2- (N-phenyl-N-methylamino) -6- (Np-tolyl-N-ethyl) amino-fluorane, 2-anilino. -3-methyl-6- (N-ethyl-p-toluidino) fluorane, 3,6-dimethoxyfluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) ) -Fluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane, 3 -(N, N-diethylamino) -6-methyl-7-xylidinofluorane, 3- (N, N-diethylamino) -6-methyl-7-chloro Fluorane, 3- (N, N-diethylamino) -6-methoxy-7-aminofluorane, 3- (N, N-diethylamino) -7- (4-chloroanilino) fluorane, 3- (N, N-diethylamino) -7-chlorofluorane, 3- (N, N-diethylamino) -7-benzylaminofluorane, 3- (N, N-diethylamino) -7,8-benzofluorane, 3- (N, N-dibutyl) Amino) -6-methyl-7-anilinofluorane, 3- (N, N-dibutylamino) -6-methyl-7-xylidinofluorane, 3-piperidino-6-methyl-7-anilinofluorane 3-pyrrolidino-6-methyl-7-anilinofluorane, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis (1-n-butyl- -Methylindol-3-yl) phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl- 2-methylindol-3-yl) -4-zaphthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, and the like.

  A suitable addition amount of the dye that changes color by acid or radical is 0.01 to 15% by mass relative to the solid content of the photosensitive layer.

<Polymerization inhibitor>
It is preferable to add a small amount of a thermal polymerization inhibitor to the photosensitive layer of the present invention in order to prevent unnecessary thermal polymerization of the radical polymerizable compound during the production or storage of the photosensitive layer.
Examples of the thermal polymerization inhibitor include hydroquinone, 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-tert-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt are preferred.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the photosensitive layer.

<Higher fatty acid derivatives>
In order to prevent polymerization inhibition by oxygen, a higher fatty acid derivative such as behenic acid or behenamide is added to the photosensitive layer of the present invention so that it is unevenly distributed on the surface of the photosensitive layer during the drying process after coating. May be. The amount of the higher fatty acid derivative added is preferably from about 0.1 to about 10% by mass based on the total solid content of the photosensitive layer.

<Plasticizer>
The photosensitive layer of the present invention may contain a plasticizer. Examples of the plasticizer include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate; Glycol esters such as glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate Diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioct Ruazereto, aliphatic dibasic acid esters such as dibutyl maleate; polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate in. The plasticizer content is preferably about 30% by mass or less based on the total solid content of the photosensitive layer.

<Inorganic fine particles>
The photosensitive layer of the present invention may contain inorganic fine particles in order to improve the strength of the cured film in the image area. As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate, or a mixture thereof is preferably exemplified. Even if they are not photothermally convertible, they can be used for strengthening the film, enhancing interfacial adhesion by surface roughening, and the like. The inorganic fine particles preferably have an average particle size of 5 nm to 10 μm, and more preferably 0.5 to 3 μm. Within the above range, it is possible to form a non-image portion having excellent hydrophilicity, which is stably dispersed in the photosensitive layer, sufficiently retains the film strength of the photosensitive layer, and hardly causes stains during printing.
The inorganic fine particles as described above can be easily obtained as a commercial product such as a colloidal silica dispersion.
The content of the inorganic fine particles is preferably 20% by mass or less, and more preferably 10% by mass or less, based on the total solid content of the photosensitive layer.

<Low molecular hydrophilic compound>
The photosensitive layer of the present invention can contain a hydrophilic low molecular weight compound for improving developability. Examples of the hydrophilic low-molecular compound include water-soluble organic compounds such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and salts thereof, organic phosphonic acids such as phenylphosphonic acid and the like Organic carboxylic acids such as salts, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, amino acids and their salts, and organic quaternary amines such as tetraethylamine hydrochloride Salt, and the like.

<Formation of photosensitive layer>
The photosensitive layer of the present invention is formed by preparing or applying a coating solution by dispersing or dissolving the necessary components described above in a solvent. Solvents used here include 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 Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The photosensitive layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeatedly applying and drying a plurality of times.

The coating, the photosensitive layer coating amount on the support obtained after drying (solid content) may be varied according to the intended purpose, generally 0.3 to 3.0 g / m ² is preferred. Within this range, good sensitivity and good film properties of the photosensitive layer can be obtained.
Various methods can be used as the coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

(Protective layer)
In the lithographic printing plate precursor according to the invention, a protective layer (oxygen blocking layer) is preferably provided on the photosensitive layer in order to block diffusion and penetration of oxygen that hinders the polymerization reaction during exposure. The protective layer used in the present invention preferably has an oxygen permeability A at 25 ° C. and 1 atm of 1.0 ≦ A ≦ 20 (mL / m ² · day). If the oxygen permeability A is less than 1.0 (mL / m ² · day), an unnecessary polymerization reaction may occur during production and raw storage, and unnecessary fogging and image lines may occur during image exposure. This causes the problem of fatness. Conversely, when the oxygen permeability A exceeds 20 (mL / m ² · day) and is too high, the sensitivity is lowered. The oxygen permeability A is more preferably in the range of 1.5 ≦ A ≦ 12 (mL / m ² · day), more preferably 2.0 ≦ A ≦ 10.0 (mL / m ² · day). In addition to the oxygen permeability described above, the properties desired for the protective layer further do not substantially impede the transmission of light used for exposure, have excellent adhesion to the photosensitive layer, and are easy in the development process after exposure. It is desirable that it can be removed. The device concerning such a protective layer has been conventionally made, and is described in detail in US Pat. No. 3,458,311 and JP-B-55-49729.

  As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, vinyl alcohol / vinyl phthalate copolymer, vinyl acetate / vinyl are used. Examples include water-soluble polymers such as alcohol / vinyl phthalate copolymer, vinyl acetate / crotonic acid copolymer, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, polyacrylic acid, and polyacrylamide. Or they can be mixed. Of these, the use of polyvinyl alcohol as the main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability.

  The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. Specific examples of polyvinyl alcohol include those that are hydrolyzed by 71 to 100 mol% and have a polymerization repeating unit in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-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, and these can be used alone or in combination. In a preferred embodiment, the content of polyvinyl alcohol in the protective layer is 20 to 95% by mass, and more preferably 30 to 90% by mass.

  Moreover, well-known modified polyvinyl alcohol can also be used preferably. For example, various hydrophilic modification sites such as anion modification sites modified with anions such as carboxyl groups and sulfo groups, cation modification sites modified with cations such as amino groups and ammonium groups, silanol modification sites, and thiol modification sites are randomly selected. Polyvinyl alcohol having various degrees of polymerization, the anion-modified site, the cation-modified site, the silanol-modified site, the thiol-modified site, the alkoxyl-modified site, the sulfide-modified site, and the ester modification of vinyl alcohol and various organic acids. Examples thereof include polyvinyl alcohol having various polymerization degrees having various modified sites such as a site, an ester-modified site of the anion-modified site and alcohols, an epoxy-modified site, and the like.

  As a component used by mixing with polyvinyl alcohol, polyvinyl pyrrolidone or a modified product thereof is preferable from the viewpoint of oxygen barrier properties and development removability, and the content in the protective layer is 3.5 to 80% by mass, preferably 10 to 60%. It is 15 mass%, More preferably, it is 15-30 mass%.

  Components of the protective layer (selection of PVA, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of the PVA used (the higher the content of the unsubstituted vinyl alcohol unit in the protective layer), the thicker the film thickness, the higher the oxygen barrier property, which is advantageous in terms of sensitivity. The molecular weight of the (co) polymer such as polyvinyl alcohol (PVA) can be in the range of 2000 to 10 million, preferably in the range of 20,000 to 3 million.

  As other additives to the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility, and sodium alkyl sulfate, alkyl Anionic surfactants such as sodium sulfonate; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to (co) polymers Several mass% can be added.

  In addition, adhesion to the image area and scratch resistance are extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on an oleophilic photosensitive layer, film peeling due to insufficient adhesion tends to occur, and the peeled part causes defects such as poor film hardening due to inhibition of oxygen polymerization. On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, in U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563, an acrylic emulsion or a water-insoluble vinyl pyrrolidone-vinyl acetate copolymer is contained in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and laminating on a photosensitive layer. Any of these known techniques can be applied to the protective layer in the present invention. Such a coating method for the protective layer is described in detail in, for example, US Pat. No. 3,458,311 and Japanese Patent Publication No. 55-49729.

Furthermore, the protective layer in the lithographic printing plate precursor according to the invention preferably contains an inorganic stratiform compound for the purpose of improving oxygen barrier properties and photosensitive layer surface protection.
Here, the inorganic layered compound is a particle having a thin plate-like shape. For example, the following general formula A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂
[However, A is any of K, Na, and Ca, B and C are any of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. And mica groups such as natural mica and synthetic mica, talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by the formula 3MgO.4SiO.H ₂ O.

In the mica group, natural mica includes muscovite, soda mica, phlogopite, biotite, and sericite. Synthetic mica includes non-swellable mica such as fluorine phlogopite mica ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 Si ₄ O ₁₀ ) F ₂ , and Na tetrasilicic 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 Li hectorite _{(Na, Li) 1/8 Mg 2} /5 Li Examples thereof include swelling mica such as _1/8 (Si ₄ O ₁₀ ) F ₂ . Synthetic smectite is also useful.

In the present invention, among the inorganic layered compounds, fluorine-based swellable mica, which is a synthetic inorganic layered compound, is particularly useful. That is, this swellable synthetic mica and swellable viscosity minerals such as montmorillonite, saponite, hectorite, bentonite, etc. have a laminated structure composed of unit crystal lattice layers with a thickness of about 10-15A, Atomic substitution is significantly greater than other viscous minerals. As a result, the lattice layer is deficient in positive charges, and cations such as Na ⁺ , Ca ²⁺ and Mg ²⁺ are adsorbed between the layers in order to compensate for this. The cations present between these layers are called exchangeable cations and exchange with various cations. In particular, when the cation between the layers is Li ⁺ or Na ⁺ , the bond between the layered crystal lattices is weak because the ionic radius is small, and the layer swells greatly with water. If shear is applied in this state, it will easily cleave and form a stable sol in water. Bentonite and swellable synthetic mica have this tendency and are useful in the present invention, and swellable synthetic mica is particularly preferably used.

  As the shape of the inorganic layered compound used in the present invention, from the viewpoint of diffusion control, the smaller the thickness, the better. The plane size is as long as it does not hinder the smoothness of the coated surface or the transmittance of actinic rays. Larger is better. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  As for the particle diameter of the inorganic stratiform compound used in the present invention, the average major axis is 0.3 to 20 μm, preferably 0.5 to 10 μm, 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. For example, among inorganic layered compounds, the size of the swellable synthetic mica that is a representative compound is about 1 to 50 nm in thickness and about 1 to 20 μm in surface size.

  When the inorganic layered compound particles having such a large aspect ratio are contained in the protective layer, the coating film strength is improved, and the permeation of oxygen and moisture can be effectively prevented. Deterioration is prevented, and even when stored for a long time under high-humidity conditions, the storage stability of the planographic printing plate precursor does not deteriorate due to changes in humidity, and the storage stability is excellent.

  It is preferable that content of the inorganic stratiform compound in a protective layer is 5/1-1/100 by mass ratio with respect to the quantity of the binder used for a protective layer. Even when a plurality of types of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass ratio.

  Next, an example of a general dispersion method of the inorganic stratiform compound used for the protective layer will be described. First, 5 to 10 parts by mass of the swellable layered compound mentioned above as a preferred inorganic layered compound is added to 100 parts by mass of water, and the mixture is thoroughly swelled and swollen, and then dispersed by a disperser. Examples of the disperser used here include various mills that disperse mechanically by applying a direct force, a high-speed stirring disperser having a large shearing force, and a disperser that provides high-intensity ultrasonic energy. Specifically, ball mill, sand grinder mill, visco mill, colloid mill, homogenizer, tisol bar, polytron, homomixer, homo blender, ketdy mill, jet agitator, capillary emulsifier, liquid siren, electrostrictive ultrasonic generator, An emulsifying device having a Paulman whistle can be used. A dispersion of 5 to 10% by mass of the inorganic stratiform compound dispersed by the above method is highly viscous or gelled and has very good storage stability. When preparing a protective layer coating solution using this dispersion, it is preferably prepared by diluting with water and stirring sufficiently, and then blending with a binder solution.

  In addition to the inorganic layered compound, known additives such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the film can be added to the protective layer coating solution. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. A water-soluble (meth) acrylic polymer can also be added. Furthermore, known additives for improving the adhesion to the photosensitive layer and the temporal stability of the coating solution may be added to the coating solution.

  The protective layer coating solution thus prepared is applied onto the photosensitive layer provided on the support and dried to form a protective layer. The coating solvent can be appropriately selected in relation to the binder, but when a water-soluble polymer is used, it is preferable to use distilled water or purified water. The method for applying the protective layer is not particularly limited, and a known method such as the method described in US Pat. No. 3,458,311 or Japanese Patent Publication No. 55-49729 can be applied. . Specific examples of the protective layer include blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, and bar coating.

The coating amount of the protective layer is preferably in the range of 0.05 to 10 g / m ^{2 in} terms of the coating amount after drying. When the inorganic layered compound is contained, 0.1 to 0.5 g / The range of m ² is more preferable, and when the inorganic layered compound is not contained, the range of 0.5 to 5 g / m ² is more preferable.

(Support)
The support used in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like hydrophilic support. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, 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 deposited. Preferable supports include a polyester film and an aluminum plate. Among these, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

  The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of different elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is preferably 10% by mass or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element. The composition of the aluminum plate is not specified, and a publicly known material can be used as appropriate.

  The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm, and even more preferably from 0.2 to 0.3 mm.

  Prior to using the aluminum plate, it is preferable to perform a surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it becomes easy to improve hydrophilicity and secure adhesion between the photosensitive layer and the support. Prior to roughening the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like for removing rolling oil on the surface is performed as desired.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment for dissolving the surface electrochemically), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric 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 electrolyte.
The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be specified in general. d m ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2. Within this range, good printing durability and good scratch resistance of the non-image area of the lithographic printing plate can be obtained.

  As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation and the like. If necessary, it contains a micropore enlargement treatment, a micropore sealing treatment, and a hydrophilic compound described in Japanese Patent Application Laid-Open Nos. 2001-253181 and 2001-322365. A surface hydrophilization treatment immersed in an aqueous solution can be selected as appropriate. Of course, these enlargement processing and sealing processing are not limited to those described above, and any conventionally known method can be performed.

Sealing treatment includes vapor sealing, single treatment with zirconic fluoride, treatment with an aqueous solution containing an inorganic fluorine compound such as treatment with sodium fluoride, vapor sealing with addition of lithium chloride, sealing with hot water. Hole processing is also possible.
Of these, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing treatment with hot water are preferable.

  The hydrophilization treatment is described in the specifications of US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There are such alkali metal silicate methods. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, And a method of treating with polyvinylphosphonic acid as described in the specification of No. 272.

  When using a support with insufficient surface hydrophilicity such as a polyester film as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony, and a transition metal described in JP-A-2001-199175 A hydrophilic layer formed by coating a coating solution containing a colloid of oxide or hydroxide, or organic hydrophilicity obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer described in JP-A-2002-79772 A hydrophilic layer having a hydrophilic matrix, a hydrophilic layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or a metal oxide A hydrophilic layer made of an inorganic thin film having a surface is preferred. Arbitrariness. Among these, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or a hydroxide colloid is preferable.

  Moreover, when using a polyester film etc. as a support body of this invention, it is preferable to provide an antistatic layer in the hydrophilic layer side of a support body, the opposite side, or both sides. In the case where the antistatic layer is provided between the support and the hydrophilic layer, it also contributes to improving the adhesion with the hydrophilic layer. As the antistatic layer, a polymer layer in which metal oxide fine particles or a matting agent are dispersed as described in JP-A-2002-79772 can be used.

The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the photosensitive layer, good printing durability and good stain resistance can be obtained.
The color density of the support is preferably 0.15 to 0.65 as the reflection density value. Within this range, good image formability by preventing halation during image exposure and good plate inspection after development can be obtained.

(Undercoat layer)
In the planographic printing plate precursor of the invention used in the planographic printing method of the invention, an undercoat layer can be provided between the photosensitive layer and the support, if necessary. Since the undercoat layer functions as a heat insulating layer, heat generated by exposure with an infrared laser does not diffuse to the support and can be used efficiently, so that there is an advantage that high sensitivity can be achieved. In the unexposed area, the on-press developability is improved because the photosensitive layer is easily peeled off from the support.
As the undercoat layer, specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, JP-A-2-304441. The phosphorus compound etc. which have the ethylenic double bond reactive group of description are mentioned suitably.
The most preferable undercoat layer includes a polymer resin obtained by copolymerization of a monomer having an adsorptive group / a monomer having a hydrophilic group / a monomer having a crosslinkable group.

An essential component of the polymer undercoat is an adsorptive group on the surface of the hydrophilic support. The presence or absence of adsorptivity on the surface of the hydrophilic support can be determined, for example, by the following method.
A coating night is prepared by dissolving the test compound in a readily soluble solvent, and the coating night is coated and dried on the support so that the coating amount after drying is 30 mg / m ² . Next, the support coated with the test compound is sufficiently washed with a readily soluble solvent, and then the residual amount of the test compound that has not been removed by washing is measured to calculate the adsorbed amount of the support. Here, the measurement of the remaining amount may be performed by directly quantifying the amount of the remaining compound or by quantifying the amount of the test compound dissolved in the cleaning liquid. The compound can be quantified by, for example, fluorescent X-ray measurement, reflection spectral absorbance measurement, liquid chromatography measurement and the like. The compound having support adsorptivity is a compound that remains at 1 mg / m ² or more even after the above-described washing treatment.

The adsorptive group on the surface of the hydrophilic support is a substance (for example, metal, metal oxide) or a functional group (for example, hydroxyl group) existing on the surface of the hydrophilic support and a chemical bond (for example, ionic bond, hydrogen bond). , Coordination bond, bond by intermolecular force). The adsorptive group is preferably an acid group or a cationic group.
The acid group preferably has an acid dissociation constant (pKa) of 7 or less. Examples of the acid group include a phenolic hydroxyl group, a carboxyl _{group, -SO 3 H, -OSO 3 H} , -PO 3 H 2, -OPO 3 H 2, -CONHSO 2 -, - SO 2 NHSO 2 - and -COCH ₂ COCH ₃ is included. Particularly preferred are phosphoric acid groups (—OPO ₃ H ₂ , —PO ₃ H ₂ ). These acid groups may be metal salts.
The cationic group is preferably an onium group. Examples of the onium group include an ammonium group, a phosphonium group, an arsonium group, a stibonium group, an oxonium group, a sulfonium group, a selenonium group, a stannonium group, and an iodonium group. An ammonium group, a phosphonium group and a sulfonium group are preferred, an ammonium group and a phosphonium group are more preferred, and an ammonium group is most preferred.

  Particularly preferred examples of the monomer having an adsorptive group include compounds represented by the following formula (VII) or (VIII).

In the formulas (VII) and (VIII), R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms. R ¹ , R ² and R ³ are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. More preferred is a hydrogen atom or a methyl group. R ² and R ³ are particularly preferably a hydrogen atom.
In the formula (VII), X is an oxygen atom (—O—) or imino (—NH—). X is more preferably an oxygen atom. In the formulas (VII) and (VIII), L is a divalent linking group. L is a divalent aliphatic group (alkylene group, substituted alkylene group, alkenylene group, substituted alkenylene group, alkynylene group, substituted alkynylene group), divalent aromatic group (arylene group, substituted arylene group) or divalent A heterocyclic group, or an oxygen atom (—O—), a sulfur atom (—S—), an imino (—NH—), a substituted imino (—NR—, R is an aliphatic group, an aromatic group; Or a combination with a heterocyclic group) or carbonyl (—CO—).

The aliphatic group may have a cyclic structure or a branched structure. The number of carbon atoms in the aliphatic group is preferably 1 to 20, more preferably 1 to 15, and most preferably 1 to 10. The aliphatic group is preferably a saturated aliphatic group rather than an unsaturated aliphatic group. The aliphatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aromatic group, and a heterocyclic group.
The number of carbon atoms in the aromatic group is preferably 6 to 20, more preferably 6 to 15, and most preferably 6 to 10. The aromatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aliphatic group, an aromatic group, and a heterocyclic group.
The heterocyclic group preferably has a 5-membered or 6-membered ring as the heterocycle. The heterocycle may be condensed with another heterocycle, aliphatic ring or aromatic ring. The heterocyclic group may have a substituent. Examples of substituents include halogen atoms, hydroxyl groups, oxo groups (═O), thioxo groups (═S), imino groups (═NH), substituted imino groups (═N—R, R is an aliphatic group, aromatic Group or heterocyclic group), aliphatic group, aromatic group and heterocyclic group.
L is preferably a divalent linking group containing a plurality of polyoxyalkylene structures. The polyoxyalkylene structure is more preferably a polyoxyethylene structure. In other words, L preferably contains — (OCH ₂ CH ₂ ) _n — (n is an integer of 2 or more).
In the formulas (VII) and (VIII), Z is a functional group adsorbed on the hydrophilic support surface. In formula (VIII), Y is a carbon atom or a nitrogen atom. When Y is a nitrogen atom and L is connected to Y to form a quaternary pyridinium group, Z is not essential because it exhibits adsorptivity itself. The adsorptive functional group is as described above.
Examples of typical monomers represented by formula (VII) or (VIII) are shown below.

  Examples of the hydrophilic group of the undercoat polymer resin that can be used in the present invention include a hydroxy group, a carboxyl group, a carboxylate group, a hydroxyethyl group, a polyoxyethyl group, a hydroxypropyl group, a polyoxypropyl group, and an amino group. Preferred examples include a group, an aminoethyl group, an aminopropyl group, an ammonium group, an amide group, a carboxymethyl group, a sulfonic acid group, and a phosphoric acid group. A monomer having these hydrophilic group and polymerizable group is used as a copolymerization component of the polymer resin.

  The undercoat polymer resin used in the present invention preferably has a crosslinkable group. The crosslinkable group can improve the adhesion with the image area. In order to impart crosslinkability to the polymer resin for the undercoat, a crosslinkable functional group such as an ethylenically unsaturated bond is introduced into the side chain of the polymer or has a counter charge with the polar substituent of the polymer resin. It can be introduced by forming a salt structure with a compound having a substituent and an ethylenically unsaturated bond.

  Examples of polymers having an ethylenically unsaturated bond in the side chain of the molecule are polymers of esters or amides of acrylic acid or methacrylic acid where the ester or amide residue (R of -COOR or -CONHR) is Mention may be made of polymers having an ethylenically unsaturated bond.

Examples of the residue (the R) having an ethylenically unsaturated _{bond, - (CH 2) n CR} 1 = CR 2 R 3, - (CH 2 O) n CH 2 CR 1 = CR 2 R 3, - _{(CH 2 CH 2 O) n} CH 2 CR 1 = CR 2 R 3, - (CH 2) n NH-CO-O-CH 2 CR 1 = CR 2 R 3, - (CH 2) n -O-CO -CR ₁ = _CR 2 _{R 3,} and _{- (CH 2 CH 2 O)} 2 -X ( _wherein, R 1 to R ₃
Represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkoxy group or an aryloxy group, and R ₁ and R ₂ or R ₃ may be bonded to each other to form a ring. Good. n represents an integer of 1 to 10. X represents a dicyclopentadienyl residue. ).
Specific examples of the ester residue include —CH ₂ CH═CH ₂ (described in JP-B-7-21633), —CH ₂ CH ₂ O—CH ₂ CH═CH ₂ , —CH ₂ C. _{(CH 3) = CH 2,} -CH 2 CH = CH-C 6 H 5, -CH 2 CH 2 OCOCH = CH-C 6 H 5, -CH 2 CH 2 NHCOO-CH 2 CH = CH 2, and - CH ₂ CH ₂ O—X (wherein X represents a dicyclopentadienyl residue).
Specific examples of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ O—Y (wherein Y represents a cyclohexene residue), —CH ₂ CH ₂ OCO—CH═CH _2. Is mentioned.
As the monomer having a crosslinkable group of the polymer resin for undercoating, an ester or amide of acrylic acid or methacrylic acid having the crosslinkable group is preferable.

  The content of the crosslinkable group in the polymer resin for undercoat (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol, more preferably 1 g per 1 g of the polymer resin. Is 1.0 to 7.0 mmol, most preferably 2.0 to 5.5 mmol. Within this range, both good sensitivity and dirtiness and good storage stability can be obtained.

The undercoat polymer resin preferably has a mass average molecular weight of 5000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1000 or more, preferably 2000 to 250,000. It is more preferable that The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The undercoat polymer resin may be a random polymer, a block polymer, a graft polymer, or the like, but is preferably a random polymer.

  As the undercoat polymer resin of the present invention, a known resin having a hydrophilic group can also be used. Specific examples of such resins include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl 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, hydroxybutyl Homopolymers and copolymers of methacrylates, homopolymers of hydroxybutyl acrylate Copolymers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide homopolymers having a hydrolysis degree of 60 mol% or more, preferably 80 mol% or more. Polymers and copolymers, homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, polyvinylpyrrolidone, alcohol-soluble nylon, 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin A polyether etc. are mentioned.

The undercoat polymer resin may be used alone or in combination of two or more.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / ^{m 2,} and more preferably 1 to 30 mg / ^{m 2.}

(Back coat layer)
After the surface treatment is performed on the support or after the undercoat layer is formed, a back coat can be provided on the back surface of the support, if necessary.
Examples of the back coat include hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885, an organometallic compound or an inorganic metal compound described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this way is preferred. Among them, it is inexpensive to use a silicon alkoxy compound such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) _4. It is preferable in terms of easy availability.

[Plate making method]
After the lithographic printing plate precursor in the present invention is image-exposed with a light source of 350 nm to 450 nm, the plate surface is rubbed with a rubbing member in the presence of a developer having a pH of 2 to 10 by an automatic developing machine. The photosensitive layer can be removed to form an image on the surface of the aluminum plate support. When the planographic printing plate precursor has a protective layer, the protective layer is also removed at the same time.
That is, after removing the photosensitive layer of the non-exposed portion, it can be set on a printing machine and printed immediately.
In addition, such processing in an automatic developing machine has an advantage of being freed from dealing with development residue derived from a protective layer / photosensitive layer that occurs in the case of on-press development.

  The developer used in the present invention is an aqueous solution having a pH of 2 to 10. For example, water alone or an aqueous solution containing water as a main component (containing 60% by mass or more of water) is preferable, and in particular, an aqueous solution having the same composition as a generally known fountain solution, a surfactant (anionic, nonionic, An aqueous solution containing a cationic system and the like, and an aqueous solution containing a water-soluble polymer compound are preferred. In particular, an aqueous solution containing both a surfactant and a water-soluble polymer compound is preferable. The pH of the developer is more preferably 3-8, still more preferably 4-7.

  Examples of the anionic surfactant used in the developer include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid salts, linear alkyl benzene sulfonic acid salts, branched alkyl benzene sulfonic acid salts, Alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium, N-alkyl sulfosuccinic acid monoamide disodium salts, petroleum sulfonates , Sulfated castor oil, sulfated beef tallow oil, fatty acid alkyl ester sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid compounds Glyceryl sulfate ester salt, polyoxyethylene alkylphenyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkylphenyl ether phosphate ester salt, styrene -Partial saponifications of maleic anhydride copolymer, partial saponifications of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensate and the like. Among these, dialkyl sulfosuccinates, alkyl sulfate esters and alkyl naphthalene sulfonates are particularly preferably used.

  The cationic surfactant used in the developer is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.

Nonionic surfactants used in the developer include polyethylene glycol type higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher alkylamine ethylene. Oxide adduct, fatty acid amide ethylene oxide adduct, fat and oil ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymer, etc. Alcohol-type glycerol fatty acid ester, pentaerythritol fatty acid ester, sorbitol and sorbita Fatty acid esters of fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines.
In the present invention, ethylene oxide adduct of sorbitol and / or sorbitan fatty acid ester, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymer, polyhydric alcohol Fatty acid esters are more preferred.

Further, from the viewpoint of stable solubility or turbidity in water, the nonionic surfactant used in the developer of the present invention is HLB (Hydrophile-Lipophile).
The (Balance) value is preferably 6 or more, and more preferably 8 or more.
Further, acetylene glycol-based and acetylene alcohol-based oxyethylene adducts, fluorine-based and silicone-based surfactants can also be used in the same manner.
As the surfactant used in the developer of the present invention, a nonionic surfactant is particularly suitable from the viewpoint of foam suppression.
The surfactants may be used alone or in combination of two or more. The content of the surfactant in the developer is preferably from 0.01 to 10% by mass, and more preferably from 0.01 to 5% by mass.

  Examples of the water-soluble polymer compound used in the developer of the present invention include soybean polysaccharide, modified starch, gum arabic, dextrin, fibrin derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, pullulan. , Polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone, polyacrylamide and acrylamide copolymer, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride copolymer, etc. It is done.

  A well-known thing can be used for the said soybean polysaccharide, for example, there exists a brand name Soya Five (made by Fuji Oil Co., Ltd.) as a commercial item, and the thing of various grades can be used. What can be preferably used is one in which the viscosity of a 10% by mass aqueous solution is in the range of 10 to 100 mPa / sec.

  As the modified starch, known ones can be used, and starch such as corn, potato, tapioca, rice and wheat is decomposed with acid or enzyme in the range of 5 to 30 glucose residues per molecule, and further in an alkali. It can be made by a method of adding oxypropylene or the like.

  Two or more water-soluble polymer compounds can be used in combination. The content of the water-soluble polymer compound in the developer is preferably from 0.1 to 20% by mass, and more preferably from 0.5 to 10% by mass.

  Further, the developer of the present invention may contain an organic solvent. Examples of the organic solvent that can be contained include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (manufactured by Esso Chemical Co., Ltd.) or gasoline, kerosene, etc.), and aromatic hydrocarbons (toluene). , Xylene, etc.), halogenated hydrocarbons (methylene dichloride, ethylene dichloride, tricrene, monochlorobenzene, etc.) and polar solvents.

Polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether , Propylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polypropylene glycol, tetraethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, ethylene glycol monophenyl ether, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol, etc.) , (Acetone, methyl ethyl ketone, ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), esters (ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, methyl lactate, butyl lactate, ethylene glycol monobutyl acetate, propylene Glycol monomethyl ether acetate, diethylene glycol acetate, diethyl phthalate, butyl levulinate, etc.) and others (triethyl phosphate, tricresyl phosphate, N-phenylethanolamine, N-phenyldiethanolamine, etc.).

  If the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. If the developer contains an organic solvent, safety, ignition, From the viewpoint of property, the concentration of the solvent is preferably less than 40% by mass.

  In addition to the above, the developer of the present invention may contain a preservative, a chelate compound, an antifoaming agent, an organic acid, an inorganic acid, an inorganic salt, and the like.

  Preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzisothiazolin-3-one, benztriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, pyridine, Derivatives such as quinoline and guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives, nitrobromoalcohol-based 2-bromo-2-nitropropane-1,3diol, 1,1-dibromo-1-nitro-2-ethanol, 1,1-dibromo-1-nitro-2-propanol and the like can be preferably used.

  Examples of chelate compounds include ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, potassium salt thereof, sodium salt thereof, and hydroxyethylethylenediaminetriacetic acid. Nitrilotriacetic acid, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri (methylenephosphonic acid), potassium salt, sodium salt And organic phosphonic acids and phosphonoalkanetricarboxylic acids. Organic amine salts are also effective in place of the sodium and potassium salts of the chelating agents.

As the antifoaming agent, a general silicone-based self-emulsifying type, emulsifying type, nonionic surfactant having a HLB of 5 or less can be used. Silicone defoamers are preferred.
Among them, emulsification dispersion type and solubilization can be used.

  Examples of organic acids include citric acid, acetic acid, succinic acid, malonic acid, salicylic acid, caprylic acid, tartaric acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic acid, xylenesulfonic acid, phytic acid, and organic phosphonic acid. . The organic acid can also be used in the form of its alkali metal salt or ammonium salt.

  Examples of inorganic acids and inorganic salts include phosphoric acid, metaphosphoric acid, primary ammonium phosphate, secondary ammonium phosphate, primary sodium phosphate, secondary sodium phosphate, primary potassium phosphate, secondary potassium phosphate, Examples include sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium sulfite, ammonium sulfite, sodium hydrogen sulfate, nickel sulfate and the like.

  The developer described above can be used as a developer and developer replenisher for the exposed lithographic printing plate precursor, and is preferably applied to an automatic processor described later. When developing using an automatic processor, the developing solution becomes fatigued according to the amount of processing, so the processing capability may be restored using a replenisher or a fresh developer. This replenishing method is also preferably applied to the lithographic printing plate making method of the present invention.

  The development treatment with an aqueous solution having a pH of 2 to 10 in the present invention can be preferably carried out by an automatic processor equipped with a developer supply means and a rubbing member. As an automatic processor, for example, an automatic processor described in JP-A-2-220061 and JP-A-60-59351, which performs a rubbing process while transporting a lithographic printing plate precursor after image recording, or a cylinder Examples thereof include an automatic processor described in US Pat. Nos. 5,148,746, 5,568,768 and British Patent 2,297,719, which rub the lithographic printing plate precursor after image recording set thereon while rotating a cylinder. Among these, an automatic processor using a rotating brush roll as the rubbing member is particularly preferable.

The rotating brush roll that can be preferably used in the present invention can be appropriately selected in consideration of the difficulty of scratching the image area and the stiffness of the support of the lithographic printing plate precursor. As the rotating brush roll, a known one formed by planting a brush material on a plastic or metal roll can be used. For example, as described in Japanese Patent Application Laid-Open No. 58-159533, Japanese Patent Application Laid-Open No. 3-100554, or Japanese Utility Model Publication No. 62-167253, metal or plastic in which brush materials are implanted in rows. A brush roll in which the groove mold material is radially wound around a plastic or metal roll as a core without any gap can be used.
The brush material includes plastic fibers (for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6.6 and nylon 6.10, polyacrylonitrile, poly (meth) acrylate, etc. Acrylic and polyolefin synthetic fibers such as polypropylene and polystyrene) can be used. For example, the fiber has a hair diameter of 20 to 400 μm and a hair length of 5 to 30 mm. Can be used.
Furthermore, the outer diameter of the rotating brush roll is preferably 30 to 200 mm, and the peripheral speed at the tip of the brush rubbing the plate surface is preferably 0.1 to 5 m / sec.
Moreover, it is preferable to use two or more rotating brush rolls.

  The rotating direction of the rotating brush roll used in the present invention may be the same or opposite to the conveying direction of the planographic printing plate precursor of the present invention. Thus, when two or more rotating brush rolls are used, it is preferable that at least one rotating brush roll rotates in the same direction and at least one rotating brush roll rotates in the opposite direction. This further ensures the removal of the heat sensitive layer in the non-image area. Furthermore, it is also effective to swing the rotating brush roll in the direction of the rotation axis of the brush roll.

  Although the temperature of the developer can be used at any temperature, it is preferably 10 ° C to 50 ° C.

In the present invention, the lithographic printing plate after the rubbing treatment can be optionally washed with water, dried and desensitized. In the desensitizing treatment, a known desensitizing solution can be used.

  In addition, as the plate-making process of the lithographic printing plate from the lithographic printing plate precursor according to the present invention, the entire surface may be heated before exposure, during exposure, and between exposure and development, if necessary. By such heating, the image forming reaction in the photosensitive layer is promoted, and advantages such as improvement in sensitivity and printing durability and stabilization of sensitivity may occur. Further, for the purpose of improving the image strength and printing durability, it is also effective to subject the developed image to full post heating or full exposure. Usually, the heating before development is preferably performed under a mild condition of 150 ° C. or less. If the temperature is too high, problems such as covering up to the non-image area occur. Very strong conditions are used for heating after development. Usually, it is the range of 200-500 degreeC. If the temperature is low, sufficient image strengthening action cannot be obtained. If the temperature is too high, problems such as deterioration of the support and thermal decomposition of the image area occur.

The plate making process will be further described in detail.
In the present invention, as described above, the development treatment may be performed immediately after the exposure step, but a heat treatment step may be provided between the exposure step and the development step. This heat treatment has the effect of improving the printing durability and further improving the uniformity of the image curing degree within the plate surface, and the conditions can be appropriately set within the range where these effects are present. Examples of the heating means include a conventional convection oven, an IR irradiation device, an IR laser, a microwave device, a Wisconsin oven, and the like. Specifically, it can be carried out by holding the plate surface temperature in the range of 70 to 150 ° C. for 1 second to 5 minutes. Preferably, the temperature is 80 ° C to 140 ° C for 5 to 1 minute, more preferably 90 ° C to 130 ° C for 10 to 30 seconds. This range is preferable in that the above effect can be obtained efficiently and there is no adverse effect such as deformation of the printing plate due to heat.

In the present invention, a development processing step is performed after the above-described exposure step and preferably the heat treatment step, to obtain a lithographic printing plate. The plate setter used in the exposure process, the heat treatment means used in the heat treatment, and the developing device used in the development process are preferably connected to each other and automatically continuously processed. Specifically, it is a plate making line in which a plate setter and a developing device are coupled by a conveying means such as a conveyor. A heat treatment means may be inserted between the plate setter and the developing device, and the heating means and the developing device may be integrated.
When the printing plate to be used is easily affected by ambient light in the work environment, it is preferable that the plate making line is shielded by a filter or a cover.

After the image is formed as described above, the entire surface may be exposed with an actinic ray such as ultraviolet light to accelerate the curing of the image area. Examples of the light source for the entire surface exposure include a carbon arc lamp, a mercury lamp, a gallium lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, and various laser lights. Further, in order to obtain a sufficient printing durability, the total exposure amount is preferably at least 10 mJ / cm ² or more, more preferably 100 mJ / cm ² or more.
Heating may be performed simultaneously with the entire surface exposure, and further improvement in printing durability is recognized by heating. Examples of the heating device include a conventional convection oven, an IR irradiation device, an IR laser, a microwave device, a Wisconsin oven, and the like. At this time, the plate surface temperature is preferably 30 ° C to 150 ° C, more preferably 35 to 130 ° C, and still more preferably 40 to 120 ° C.

Prior to the above development processing, the lithographic printing plate precursor is exposed through a transparent original image having a line image, a halftone dot image or the like, or imagewise exposed by laser beam scanning or the like using digital data.
A desirable wavelength of the light source is 350 nm to 450 nm, and specifically, an InGaN semiconductor laser is suitable. The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like.

Other exposure light beams that can be used in the present invention include ultra-high pressure, high pressure, medium pressure, and low pressure mercury lamps, chemical lamps, carbon arc lamps, xenon lamps, metal halide lamps, various visible and ultraviolet laser lamps, fluorescent lamps. A lamp, a tungsten lamp, sunlight, etc. are also mentioned.
As available laser light sources of 350 nm to 450 nm, the following can be used.
As a gas laser, an Ar ion laser (364 nm, 351 nm, 10 mW to 1 W), a Kr ion laser (356 nm, 351 nm, 10 mW to 1 W), a He—Cd laser (441 nm, 325 nm, 1 mW to 100 mW), and a solid laser as Nd: YAG (YVO ₄ ) and SHG crystal × 2 combinations (355 nm, 5 mW to 1 W), Cr: LiSAF and SHG crystal combination (430 nm, 10 mW), as a semiconductor laser system, KNbO ₃ ring resonator (430 nm, 30 mW), Combination of waveguide type wavelength conversion element and AlGaAs / InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), combination of waveguide type wavelength conversion element and AlGaInP, AlGaAs semiconductor (300 nm to 350 nm, 5 mW to 100 mW) ), AlGaInN (350 nm to 450 nm, 5 mW to 30 mW), and N ₂ laser (337 nm, pulse 0.1 to 10 mJ) and XeF (351 nm, pulse 10 to 250 mJ) as a pulse laser. In particular, an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 400 to 410 nm, 5 to 30 mW) is preferable in terms of wavelength characteristics and cost.

As the lithographic printing plate exposure apparatus of the scanning exposure system, there are an internal drum system, an external drum system, and a flat bed system as an exposure mechanism, and a light source that can continuously oscillate among the above light sources can be preferably used. . Practically, the following exposure apparatus is particularly preferable in terms of the relationship between the photosensitive material sensitivity and the plate making time.
・ Single beam to triple beam exposure equipment that uses one or more gas lasers or solid-state laser light sources so that it becomes a semiconductor laser with a total output of 20 mW or more with an internal drum system. ・ A total output of 20 mW or more with a flat bed system. Multi-beam (1 to 10) exposure equipment that uses one or more semiconductor lasers, gas lasers, or solid-state lasers • Use one or more semiconductor lasers, gas lasers, or solid-state lasers to achieve a total output of 20 mW or more with the external drum system Multi-beam (1 to 9) exposure apparatus ・ Multi-beam (10 or more) exposure apparatus using one or more semiconductor lasers or solid-state lasers so that the total output is 20 mW or more by the external drum system.

In the laser direct-drawing lithographic printing plate as described above, the photosensitive material sensitivity X (J / cm ²⁾ is generally used.
), Exposure area S (cm ² ) of photosensitive material, power q (W) of one laser light source, number of lasers n
The equation (eq1) is established between the total exposure time t (s).

  X · S = n · q · t (eq 1)

i) In the case of the internal drum (single beam) system, the laser rotation speed f (radians / s), the sub-scanning length Lx (cm) of the photosensitive material, the resolution Z (dots / cm), and the total exposure time t (s) In general, equation (eq 2) holds.

  f · Z · t = Lx (eq 2)

ii) External drum (multi-beam) system Drum rotation speed F (radians / s), photosensitive material sub-scanning length Lx (cm), resolution Z (dots / cm), total exposure time t (s), number of beams In general, formula (eq 3) is established during (n).

  F.Z.n.t = Lx (eq 3)

iii) Flat head (multi-beam) system Polygon mirror rotation speed H (radians / s), photosensitive material sub-scanning length Lx (cm), resolution Z (dots / cm), total exposure time t (s), Equation (eq 4) is generally established between the number of beams (n).

  F.Z.n.t = Lx (eq 4)

Resolution (2560 dpi) required for the actual printing plate, plate size (A1 / B1, sub-scan length 42 inch), exposure conditions of about 20 sheets / hour and photosensitive characteristics of the planographic printing plate precursor of the present invention (photosensitive wavelength, By substituting (sensitivity: about 0.1 mJ / cm ² ) into the above formula, it is understood that a combination with a multi-beam exposure method using a laser having a total output of 20 mW or more is particularly preferable in the planographic printing plate precursor of the present invention. it can. Further, by combining operability, cost, etc., a combination with an external drum type semiconductor laser multi-beam (10 or more) exposure apparatus is most preferable.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

[Examples 1 to 10 and Comparative Examples 1 to 5]
[Preparation of Support 1]
In order to remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution, and then the hair diameter was 0.3 mm. The aluminum surface was grained using three bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed thoroughly with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in a 20 mass% nitric acid aqueous solution at 60 ° C for 20 seconds, and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power supply waveform is electrochemical roughening treatment using a trapezoidal rectangular wave AC with a time TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave AC. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. The amount of electricity in nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode. Then, water washing by spraying was performed.

Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode. In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. The plate was provided with a DC anodized film of 2.5 g / m ² at a current density of 15 A / dm ² using a 15 mass% sulfuric acid aqueous solution (containing 0.5 mass% of aluminum ions) as an electrolyte, then washed with water and dried. .
The center line average roughness (Ra) of the support thus obtained was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.
Further, the following undercoat liquid (1) was bar-coated and then oven-dried at 80 ° C. for 10 seconds to apply a dry coating amount of 10 mg / m ² to prepare a support having an undercoat layer.

<Undercoat liquid (1)>
・ Undercoat compound (1) below 0.017 g
・ Methanol 9.00 g
・ Water 1.00g

[Preparation of lithographic printing plate precursor (1)]
A photosensitive layer coating solution (1) having the following composition was bar coated on the support provided with the undercoat layer, followed by oven drying at 70 ° C. for 60 seconds, and a photosensitive layer having a dry coating amount of 1.1 g / m ² . A protective layer coating solution (1) having the following composition is applied on the substrate using a bar so that the dry coating amount is 0.75 g / m ^2, and then dried at 125 ° C. for 70 seconds. Thus, a lithographic printing plate precursor (1) was obtained.

<Photosensitive layer coating solution (1)>
-0.54g of the following binder polymer (1)
-Polymerizable compound (1) described in Table 1 0.48 g
・ The following sensitizing dye (1) 0.06 g
・ The following polymerization initiator (1) 0.18 g
・ The following co-sensitizer (1) 0.07 g
・ 0.40 g of ε-phthalocyanine pigment dispersion
[Pigment: 15 parts by mass, allyl methacrylate / methacrylic acid (80/20) copolymer as a dispersant: 10 parts by mass, cyclohexanone /
Methoxypropyl acetate / 1-methoxy-2-propanol = 15
Part by mass / 20 parts by mass / 40 parts by mass]
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt, the following fluorosurfactant (1) 0.001 g
・ Polyoxyethylene-polyoxypropylene condensate 0.04g
(Asahi Denka Kogyo Co., Ltd., Pluronic L44)
・ Tetraethylamine hydrochloride 0.01g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

<Protective layer coating solution (1)>
Polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 500) 40g
・ Polyvinylpyrrolidone (molecular weight 50,000) 5g
・ Poly (vinyl pyrrolidone / vinyl acetate (1/1)) (molecular weight 70,000) 0.5g
・ Surfactant (Emalex 710, manufactured by Nippon Emulsion Co., Ltd.) 0.5g
・ 950g of water

[Preparation of lithographic printing plate precursors (2) to (15)]
Lithographic printing plate precursors (2) to (15) were prepared in the same manner as the lithographic printing plate precursor (1) except that the polymerizable compound in the photosensitive layer coating solution (1) was changed to the polymerizable compounds shown in Table 1. .

(1) Exposure, development and printing For each of the above lithographic printing plate precursors (1) to (15), imagewise exposure was performed using a 405 nm semiconductor laser with an output of 100 mW while changing the energy density.

Thereafter, using the developer (1) having the following composition, development processing was performed by an automatic development processor having the structure shown in FIG. 1 to prepare an unheated lithographic printing plate. The pH of the developer was 4.6. The automatic processor is an automatic processor having two rotating brush rolls. As the rotating brush roll, the first brush roll and the polybutylene terephthalate fiber (hair diameter 200 μm, hair length 17 mm). Using a brush roll with an outer diameter of 90 mm implanted with 200 mm / min in the same direction as the conveying direction (peripheral speed 0.94 m / sec at the tip of the brush), the second brush roll is made of polybutylene terephthalate Using a brush roll having an outer diameter of 60 mm in which fibers (hair diameter: 200 μm, hair length: 17 mm) were planted, it was rotated 200 times per minute in the direction opposite to the conveying direction (peripheral speed of the brush tip: 0.63 m / sec). .
The developer was showered from the spray pipe with a circulation pump and supplied to the plate surface. The tank capacity of the developer was 10 liters.

Developer (1)
・ Water 100.00g
・ Benzyl alcohol 1.00g
・ Polyoxyethylene naphthyl ether 1.00g
(Average number of oxyethylene n = 13)
・ Dioctylsulfosuccinate sodium salt 0.50 g
・ Arabic gum 1.00g
・ Ethylene glycol 0.50g
・ Primary ammonium phosphate 0.05g
・ Citric acid 0.05g
・ Ethylenediaminetetraacetate tetrasodium salt 0.05g

On the other hand, the lithographic printing plate precursor was placed in an oven within 30 seconds after laser exposure, and the entire surface of the lithographic printing plate precursor was heated by blowing hot air, and held at 110 ° C. for 15 seconds. Then, within 30 seconds, the same development treatment as described above was performed to prepare a heated lithographic printing plate.
Next, the developed unheated lithographic printing plate and the heated lithographic printing plate are attached to a printing machine SOR-M manufactured by Heidelberg, and dampening water (EU-3 (Etchi solution manufactured by Fuji Photo Film Co., Ltd.) / Water / Using isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.), printing was performed at a printing speed of 6000 sheets per hour.

(2) Evaluation Each lithographic printing plate precursor was evaluated for developability, running suitability, sensitivity, and printing durability as follows. The results are shown in Table 1.

<Developability>
Under the above development conditions, the transport speed required to completely remove the non-image portion of the lithographic printing plate precursor was determined, and the developability was evaluated. The faster the conveyance speed, the higher the developability.
<Running aptitude>
Under the above development conditions, the area (m ² ) of the lithographic printing plate precursor that can be developed without replenishing the developer was determined, and running suitability was evaluated. The larger the area, the better the running suitability.

<Sensitivity>
After 100 sheets were printed under the above-mentioned printing conditions and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were continuously printed. With respect to the 600th printed matter in total, the exposure amount with no unevenness in the ink density in the image area was determined and evaluated as sensitivity.
<Print durability>
As described above, when the number of printed sheets is increased, the photosensitive layer is gradually worn out and the ink acceptability is lowered, so that the ink density in the printing paper is lowered. Printing durability was evaluated by the number of printed sheets when the ink density (reflection density) was reduced by 0.1 from the start of printing.

  The structures of the polymerizable compounds (1) to (10) according to the present invention in Table 1 and the polymerizable compounds (11) to (15) other than the present invention are shown below.

[Examples 11 to 15 and Comparative Examples 6 to 10]
[Preparation of lithographic printing plate precursors (16) to (25)]
The lithographic printing plate precursors (16) to (25) are prepared in the same manner as in the production of the lithographic printing plate precursor (1) except that the dry coating amount of the protective layer coating solution (1) is changed to 0.3 g / m ^2. Got.
The obtained lithographic printing plate precursors (16) to (25) were subjected to the same exposure, development and printing treatment as in Example 1 to evaluate developability, running suitability, sensitivity and printing durability. The results are shown in Table 2.

[Examples 16 to 18 and Comparative Examples 11 to 13]
[Preparation of lithographic printing plate precursor (26)]
A lithographic printing plate precursor (26) was obtained in the same manner as in the production of the lithographic printing plate precursor (1) except that the photosensitive layer coating solution (1) was changed to a photosensitive layer coating solution (2) having the following composition. The photosensitive layer of the resulting lithographic printing plate precursor (26) had a dry coating amount of 1.2 g / m ² .

<Photosensitive layer coating solution (2)>
・ The above polymerization initiator (1) 0.20 g
-Sensitizing dye (1) 0.10 g
・ Binder (1) 3.00g
-Polymerizable compound (7) described in Table 1 6.20 g
・ Royco Crystal Violet 0.20g
・ 0.10 g of the above-mentioned fluorosurfactant (1)
・ The following microcapsule liquid (3) 25.00 g
・ Methyl ethyl ketone 35.00g
・ 1-methoxy-2-propanol 35.00g

(Preparation of microcapsule solution (3))
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, isocyanuric acid EO-modified diacrylate (Toa Gosei Co., Ltd. Aronix M-215) 4 .15 g and 0.1 g of Piionin A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 3 hours. A microcapsule liquid (3) was obtained by diluting the microcapsule liquid thus obtained with distilled water so that the solid concentration was 20% by mass. The average particle size of the microcapsules was 0.25 μm.

[Preparation of planographic printing plate precursors (27) to (31)]
The lithographic printing plate precursor (27) was prepared in the same manner as the lithographic printing plate precursor (26) except that the polymerizable compound (7) in the photosensitive layer coating solution (2) was changed to the polymerizable compounds shown in Table 3. ) To (31) were obtained.
The lithographic printing plate precursors (26) to (31) were subjected to the same exposure, development and printing processes as in Example 1, and evaluated for developability, running suitability, sensitivity and printing durability. The results are shown in Table 3.

  The structures of the polymerizable compounds (16) to (17) according to the present invention in Table 3 and the polymerizable compound (18) other than the present invention are shown below.

[Examples 19 to 21 and Comparative Examples 14 to 16]
[Preparation of lithographic printing plate precursor (32)]
The photosensitive layer coating solution (1) is changed to a photosensitive layer coating solution (3) having the following composition, the protective layer coating solution (1) is changed to a protective layer coating solution (2) having the following composition, and the dry coating amount is A lithographic printing plate precursor (32) was obtained in the same manner as in the production of the lithographic printing plate precursor (1) except that the coating was applied using a bar so as to be 0.2 g / m ² . The photosensitive layer of the resulting lithographic printing plate precursor (32) had a dry coating amount of 1.1 g / m ² .

<Photosensitive layer coating solution (3)>
・ Binder polymer (1) 0.54g
-Polymerizable compound (5) described in Table 1 0.45 g
-0.06 g of the above sensitizing dye (1)
・ The above polymerization initiator (1) 0.18 g
・ Cosensitizer (1) 0.07g
・ 0.40 g dispersion of the above ε-phthalocyanine pigment
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt-Fluorosurfactant (1) 0.001 g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

<Protective layer coating solution (2)>
・ The following mica dispersion (1): 13.00 g
Polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 500) 1.30 g
-Sodium 2-ethylhexyl sulfosuccinate 0.20 g
・ Poly (vinyl pyrrolidone / vinyl acetate = 1/1) (molecular weight 70,000) 0.05g
・ Surfactant (Emalex 710, manufactured by Nippon Emulsion Co., Ltd.) 0.05g
・ Water 133.00g

(Preparation of mica dispersion (1))
To 368 g of water, 32 g of synthetic mica (“Somasif ME-100”: manufactured by Corp Chemical Co., aspect ratio: 1000 or more) was added, and dispersed using an homogenizer until the average particle size (laser scattering method) became 0.5 μm. A mica dispersion (1) was obtained.

[Preparation of lithographic printing plate precursors (33) to (37)]
The lithographic printing plate precursor (33) was prepared in the same manner as in the production of the lithographic printing plate precursor (32) except that the polymerizable compound (5) in the photosensitive layer coating solution (3) was changed to the polymerizable compounds shown in Table 4. To (37) were obtained.
The lithographic printing plate precursors (32) to (37) were subjected to the same exposure, development and printing processes as in Example 1, and evaluated for developability, running suitability, sensitivity and printing durability. The results are shown in Table 4.

  The structures of the polymerizable compounds (19) to (20) according to the present invention in Table 4 and the polymerizable compound (21) other than the present invention are shown below.

[Examples 22 to 24 and Comparative Examples 17 to 19]
[Preparation of lithographic printing plate precursor (38)]
A photosensitive layer coating solution (4) having the following composition was bar-coated on the following support 3 and then oven-dried at 70 ° C. for 60 seconds to form a photosensitive layer having a dry coating amount of 1.1 g / m ^2. The protective layer coating liquid (2) was applied on the top using a bar so that the dry coating amount was 0.3 g / m ^2, and then dried at 125 ° C. for 70 seconds to obtain a planographic printing plate precursor (38 )

[Preparation of Support 3]
An aluminum plate having a thickness of 0.3 mm was etched by being immersed in a 10% by mass aqueous sodium hydroxide solution at 60 ° C. for 25 seconds, washed with running water, neutralized with a 20% by mass nitric acid aqueous solution, and then washed with water. This was subjected to an electrolytic surface roughening treatment in a 1% by mass nitric acid aqueous solution using a sinusoidal alternating waveform current at an anode time electricity of 300 coulomb / dm ² . Subsequently, after being immersed in a 1% by mass aqueous sodium hydroxide solution at 40 ° C. for 5 seconds, immersed in a 30% by mass sulfuric acid aqueous solution and desmutted at 60 ° C. for 40 seconds, a current density of 2 A in a 20% by mass sulfuric acid aqueous solution was obtained. Anodization was performed for 2 minutes so that the thickness of the anodized film was 2.7 g / m ² under the conditions of / dm ² . The centerline average roughness (Ra) of the surface was measured and found to be 0.3 μm.
After applying the following undercoat liquid (2) to the thus treated aluminum plate with a bar, it was oven dried at 80 ° C. for 20 seconds to apply a dry coating amount of 10 mg / m ² to prepare a support. did.

<Undercoat liquid (2)>
・ 100g of the following sol solution
・ Methanol 900g

Sol solution
・ Hosmer PE (Unichemical Co., Ltd.) 5g
・ Methanol 45g
・ Water 10g
・ 85% phosphoric acid 5g
・ Tetraethoxysilane 20g
・ 3-Methacryloxypropyltrimethoxysilane 15g

<Photosensitive layer coating solution (4)>
・ Binder polymer (1) 0.54g
・ 0.48 g of the above polymerizable compound (1)
-0.06 g of the above sensitizing dye (1)
・ The above polymerization initiator (1) 0.18 g
・ Cosensitizer (1) 0.07g
・ 0.40 g dispersion of the above ε-phthalocyanine pigment
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt-Fluorosurfactant (1) 0.001 g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

[Production of lithographic printing plate precursors (39) to (43)]
The lithographic printing plate precursor (39) was prepared in the same manner as the lithographic printing plate precursor (38) except that the polymerizable compound (1) in the photosensitive layer coating solution (4) was changed to the polymerizable compounds shown in Table 5. ) To (43) were obtained.
The lithographic printing plate precursors (38) to (43) were subjected to the same exposure, development and printing treatment as in Example 1 to evaluate developability, running suitability, sensitivity and printing durability. The results are shown in Table 5.

As is clear from the above results, a lithographic printing plate precursor using a polymerizable compound having a partial structure represented by the general formula (1) of the present invention for the photosensitive layer is used for such a polymerizable compound in the photosensitive layer. It is superior in developability, sensitivity, running suitability and printing durability as compared with a lithographic printing plate precursor of a comparative example which is not used.

Structure of automatic processor

Explanation of symbols

1: Rotating brush roll 2: Receiving roll 3: Transport roll 4: Transport guide plate 5: Spray pipe 6: Pipe line 7: Filter 8: Plate feed table 9: Discharge plate 10: Developer tank 11: Circulation pump 12: Plate

Claims (6)

A lithographic printing plate precursor having a photosensitive layer containing a polymerizable compound having a partial structure represented by the following general formula (1) and a binder polymer having an acid value of 0.3 meq / g or less on a support.
In the formula, X represents a functional group linked by any one of a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom, and Y is linked by any one of an oxygen atom, a nitrogen atom, a carbon atom, and a sulfur atom. R ₁ and R ₂ each independently represent a hydrogen atom, a halogen atom, a cyano group, or an organic residue, or a ring formed by any two or more of R ₁ , R ₂ , X, and Y May be formed.   The lithographic printing plate precursor as claimed in claim 1, wherein the polymerizable compound has two or more partial structures represented by the general formula (1) in the molecule.   The lithographic printing plate precursor as claimed in claim 1 or 2, wherein the photosensitive layer further contains a sensitizing dye having an absorption maximum in a wavelength region of 350 to 450 nm.   The lithographic printing plate precursor as claimed in any one of claims 1 to 3, further comprising a protective layer on the photosensitive layer.   After the lithographic printing plate precursor according to any one of claims 1 to 4 is image-exposed with a laser of 350 to 450 nm, the presence of a developer having a pH of 2 to 10 by an automatic processor equipped with a rubbing member A method for preparing a lithographic printing plate, comprising: removing a photosensitive layer in a non-exposed portion by rubbing the plate surface with a rubbing member.   6. The method for producing a lithographic printing plate according to claim 5, wherein the exposed lithographic printing plate precursor is subjected to a heat treatment between image exposure and development processing.