JP2008179141A - Planographic printing plate precursor and planographic printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative planographic printing plate which can be directly made from digital data such as a computer by recording in use of a solid laser or a semiconductor laser to radiate ultraviolet light, visible light, or infrared light, especially an easy-to-treat negative planographic printing plate with high sensitivity and long plate life which can be developed in an aqueous solution of pH10 or less and on a printing machine, and to provide a planographic printing method using it. <P>SOLUTION: The base of the negative planographic printing plate includes thereon a photosensitive layer containing a binder polymer including a functional group of a dipole moment at 3.8 debye or more and an acid value at 0.3 meq/g or less, a radical polymer compound, and a radical polymerization initiator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a so-called lithographic printing plate precursor capable of direct plate making using various lasers from a digital signal from a computer or the like, particularly a simple processing type lithographic printing plate precursor not requiring alkali development, and the same The present invention relates to a lithographic printing method.

  Solid lasers, semiconductor lasers, and gas lasers that emit ultraviolet light, visible light, and infrared light having a wavelength of 300 nm to 1200 nm are easily available in high output and small size. It is very useful as a recording light source when making a plate directly from digital data. Various researches have been made on recording materials sensitive to these various laser beams. As a typical example, firstly, US Pat. No. 4,708,925 (Patent Document 1) discloses a material that can be recorded with an infrared laser having a photosensitive wavelength of 760 nm or more. And the acid-catalyst-crosslinked negative recording material described in JP-A-8-276558 (Patent Document 2). Second, the radical polymerization type recording materials described in US Pat. No. 2,850,445 (Patent Document 3) and Japanese Patent Publication No. 44-20189 (Patent Document 4) as recording materials compatible with ultraviolet light or visible light laser of 300 nm to 700 nm. There are many negative recording materials. These materials have practically sufficient image forming sensitivity, but are further increased in order to extend the life of the exposure light source or increase the number of printing plates that can be produced per hour (improvement in productivity). Higher sensitivity is required.

  Usually, a binder is added to a photosensitive layer used for an image forming material, and the binder has a function of improving image strength, heat resistance of a film, and the like. For example, when the binder which has a maleimide group in a side chain is used, it is described that the heat resistance of the cured film obtained improves by the outstanding thermal stability of a maleimide group (refer patent document 5). When a polymer having an ethylenically unsaturated bond in the side chain is used, a film having a higher crosslinking density can be formed because the binder is involved in the polymerization, so that a photosensitive composition giving a cured film having a high strength can be obtained. (See Patent Document 6). When a binder having a cyclic ether group and an ethylenically unsaturated bond in the side chain is used, an image forming material that provides a cured film having good aqueous solution developability and high strength due to the high hydrophilicity of the cyclic ether group. It is described that it is obtained (see Patent Document 7). When a binder obtained by copolymerizing a monomer in which the methyl group in the methacryl group is substituted with a hetero atom is used, the amount of the radical polymerizable compound added is increased in order to improve compatibility with the radical polymerizable compound. It is described that a photopolymerizable composition can be obtained which can be increased and can provide a film having good storage stability and high film strength (see Patent Document 8). When using a binder having a lactone group or an acid anhydride group as an alkali hydrolyzable group in the side chain, the developability is improved by hydrolyzing the lactone ring during alkali development. It is described that a photopolymerizable composition that forms a cured film can be obtained (see Patent Document 9). Among the lactone group and acid anhydride group described as the alkali hydrolyzable group in Patent Document 9, several functional groups having a dipole moment of 3.8 Debye or more are included. However, these groups accidentally have only a dipole moment of 3.8 debyes or more, and Patent Document 9 discloses no technical idea regarding a functional group having a dipole moment of 3.8 debyes or more. There is no suggestion. When a polymer having a phenyl group substituted with a vinyl group in the side chain is used, the reason is not clear, but the polymerization reaction easily proceeds because the phenyl group substituted with a vinyl group exists in an aligned state in the film. It is described that a photosensitive composition having high sensitivity and no latent image regression can be obtained (see Patent Document 10). When a binder having a multipoint hydrogen bonding group is used, since there is crosslinking due to hydrogen bonding in addition to crosslinking due to radical polymerization, a polymerizable composition capable of providing a highly sensitive and high strength film can be obtained. (See Patent Document 11). Some of the functional groups having a dipole moment of 3.8 Debye or more are included in the amide group described as a multipoint hydrogen bonding group in Patent Document 11. However, these groups accidentally have only a dipole moment of 3.8 debyes or more, and Patent Document 11 discloses no technical idea regarding a functional group having a dipole moment of 3.8 debyes or more. There is no suggestion. Furthermore, in any of these patent documents, there is no description that the radical polymerization reactivity of the radical polymerizable compound is increased by these binders and that both sensitivity and printing durability are improved.

In addition, in the conventional PS plate, a step (development processing) for dissolving and removing the non-image area after exposure is indispensable, and the developed printing plate is washed with water or treated with a rinse solution containing a surfactant. In addition, a post-treatment step of treating with a desensitizing solution containing gum arabic or a starch derivative is also necessary. The point that these additional wet treatments are indispensable is a big problem for the conventional PS plate. Even if the first half (image forming process) of the plate making process is simplified by the digital processing, the effect of the simplification is insufficient in the wet process where the second half (development process) is complicated.
Particularly in recent years, consideration for the global environment has become a major concern for the entire industry. In consideration of the environment, processing with a developing solution closer to the neutral range and a small amount of waste liquid are cited as problems. Furthermore, it is desirable to simplify the wet post-treatment or change to a dry treatment.

From this point of view, one method of eliminating the processing step is to mount the exposed printing original plate on the cylinder of the printing press, and supply dampening water and ink while rotating the cylinder to remove the non-printing original plate. There is a method called on-machine development that removes the image area. That is, after the printing original is exposed, it is mounted on a printing machine as it is, and the developing process is completed in a normal printing process.
Such a lithographic printing plate precursor suitable for on-press development has an image forming layer soluble in dampening water or an ink solvent, and is suitable for development on a printing press placed in a bright room. It is necessary to have good light room handling.
In the conventional PS plate, it is practically impossible to satisfy such a requirement.

Therefore, in order to satisfy such requirements, a lithographic printing plate precursor in which an image forming layer in which thermoplastic hydrophobic polymer fine particles are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support has been proposed. (For example, refer to Patent Document 12). In making the plate, it is exposed with an infrared laser, and the thermoplastic hydrophobic polymer fine particles are coalesced (fused) with heat generated by photothermal conversion to form an image. On-press development can be performed by supplying at least one of water and ink. This lithographic printing plate precursor also has handleability in a bright room because the photosensitive region is an infrared region.
However, an image formed by coalescence (fusion) of thermoplastic hydrophobic polymer fine particles has insufficient strength and has a problem in printing durability as a printing plate.

In addition, a lithographic printing plate precursor including microcapsules encapsulating a polymerizable compound in place of the thermoplastic fine particles has been proposed (see, for example, Patent Documents 13 to 18). The original plate according to such a proposal has an advantage that the polymer image formed by the reaction of the polymerizable compound is superior in strength to the image formed by fusing fine particles.
In addition, since the polymerizable compound has high reactivity, many methods for isolating it using microcapsules have been proposed. It has been proposed to use a thermally decomposable polymer for the shell of the microcapsule.

However, in the conventional lithographic printing plate precursors described in Patent Documents 12 to 18, the sensitivity and printing durability of images formed by laser exposure are not sufficient, and further improvements are required. That is, these simple processing type lithographic printing plate precursors use a highly hydrophilic photosensitive layer in order to enable development with an aqueous solution having a pH of 10 or less or a dampening solution (usually almost neutral) on a printing press. As a result, the image portion is easily damaged by the dampening water during printing. Even when such a binder as described in Patent Documents 5 to 11 is used for such a printing plate, a lithographic printing plate precursor having sufficient processability, sensitivity, and printing durability cannot be obtained.

US Pat. No. 4,708,925 JP-A-8-276558 U.S. Pat. No. 2,850,445 Japanese Patent Publication No. 44-20189 JP 2001-337454 A JP-A-6-105353 JP 2002-12607 A JP 2002-107927 A JP 2004-317652 A JP 2001-290271 A JP 2005-300817 A Japanese Patent No. 2938397 JP 2000-2111262 A JP 2001-277740 A JP 2002-29162 A JP 2002-46361 A JP 2002-137562 A JP 2002-326470 A

  Accordingly, an object of the present invention is to provide a lithographic printing plate precursor capable of making a plate directly from digital data such as a computer by recording using a solid-state laser or semiconductor laser that emits ultraviolet light, visible light, or infrared light. An object of the present invention is to provide a high-sensitivity, high-printing simple processing type lithographic printing plate precursor which can be developed on an aqueous solution or a printing press, and a lithographic printing method using the same.

  As a result of intensive studies, the present inventors have found that a binder polymer having a functional group having a dipole moment of 3.8 Debye or more and an acid value of 0.3 meq / g or less on the support, a radical polymerizable compound, and It has been found that the above object is achieved by a lithographic printing plate precursor having a photosensitive layer containing a radical polymerization initiator and a lithographic printing method using the same.

That is, the present invention is as follows.
(1) Binder polymer having a functional group having a dipole moment of 3.8 debyes or more and an acid value of 0.3 meq / g or less on the support, a radical polymerizable compound, and a radical polymerization initiator A lithographic printing plate precursor having a photosensitive layer containing.
(2) The functional group having a dipole moment of 3.8 Debye or more is a functional group represented by the following general formula (1), (2), (3), (4) or (5) The lithographic printing plate precursor as described in (1) above.

Wherein, X and Y are each _{-C (R 5) (R 6} ) -, - C (R 5) =, - O -, - S -, - N (R
₅ )-or -N =, Z ₁ represents O or S, Z ₂ represents O or a lone pair, Z ₃
-C is _{(R 5) (R 6)} -, - C (R 5) =, - O -, - S -, - N (R 5) - or an -N =. R _{1 to} R ₆ each independently represent a substituent consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon, or any two of them may be bonded to each other. To form a ring. However, at least one of R _{1 to} R ₆ is a divalent linking group linked to a binder polymer skeleton consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon. .

(3) The lithographic printing plate precursor as described in (1) or (2), wherein the binder polymer contains more than 20 mol% of repeating units having a functional group having a dipole moment of 3.8 debyes or more. .
(4) The lithographic printing plate precursor as described in any one of (1) to (3), wherein the photosensitive layer further contains a sensitizing dye having absorption at 300 to 1200 nm.
(5) The lithographic printing plate precursor as described in any one of (1) to (4), wherein a protective layer is provided on the photosensitive layer.

(6) The lithographic printing plate precursor as described in any one of (1) to (5), which can be developed with an aqueous solution having a pH of 10 or less.
(7) The lithographic printing plate precursor as described in any one of (1) to (5), which can be mounted on a printing machine and printed without any processing after image exposure.
(8) The lithographic printing plate precursor as described in (7) was mounted on a printing press and imagewise exposed with a laser, or imagewise exposed with a laser and then mounted on a printing press and exposed. A lithographic printing method characterized in that printing ink and fountain solution are supplied to a lithographic printing plate precursor to remove an unexposed portion of the photosensitive layer and perform printing.

  According to the present invention, a lithographic printing original plate having a high productivity capable of so-called direct plate making that can be directly made using various lasers from a digital signal of a computer or the like, particularly a simple processing type lithographic printing that does not require development with an alkaline aqueous solution. A plate precursor and a lithographic printing method using the same are obtained.

Hereinafter, the planographic printing plate precursor according to the invention will be described in detail. The lithographic printing plate precursor according to the present invention comprises a binder polymer having a functional group having a dipole moment of 3.8 debye or more and an acid value of 0.3 meq / g or less on a support, a radical polymerizable compound, and It has a photosensitive layer containing a radical polymerization initiator.
Hereinafter, the constituent components of the photosensitive layer will be described in more detail.

[Binder polymer having a functional group with a dipole moment of 3.8 Debye or more and an acid value of 0.3 meq / g or less]
The binder polymer having a functional group having a dipole moment of 3.8 Debye or more and an acid value of 0.3 meq / g or less used in the lithographic printing plate precursor according to the present invention is the main chain, side in the binder polymer. A functional group having a dipole moment of 3.8 Debye or more exists at any position of the chain, and a carboxylic acid group (—COOH), a sulfonic acid group (—SO ₃ H), or a dihydrogen phosphate group (—OPO) (OH) ₂ ), phosphoric acid monohydrogen group (-OPO (OH) (OM)), phosphonic acid dihydrogen group (-PO (OH) ₂ ), phosphonic acid monohydrogen group (-PO (OH) (OM)) [is ^{M, Na +, K +,} Li + , etc. of a metal cation, ammonium represents the ions such as tetramethylammonium] sulfate group (-OSO ₃ H) amounts the following formula an acid group consisting of (1) is satisfied It is preferable that it is a binder polymer contained in.

Here, the dipole moment used in the present invention will be described.
The dipole moment in the present invention employs a value calculated by the following method using the molecular orbital method. The dipole moment is calculated by solving the Hartree-Fock-Rothaan equation FC = SCE (F; Hartley-Fock matrix, C; AO coefficient matrix, S; overlap integral, E; energy eigenvalue matrix) In the present invention, “MOPAC” which is a semi-empirical molecular orbital calculation program is used. “MOPAC” is a method for ignoring the differential overlap of two-electron integrals, and further reducing the amount of calculations by using parameters (for example, AM1 parameters) instead of integral calculations for atoms and some typical molecular experimental values. This is a calculation method widely known in the art, and details are described in “5th edition, Experimental Chemistry Course 12: Computational Chemistry” (Maruzen), p. 48-59, edited by the Chemical Society of Japan. With reference to these descriptions, the dipole moment in this specification can be calculated.

In the present invention, any binder polymer having a functional group having a dipole moment of 3.8 debyes or more can be suitably used. However, the binder polymer having a functional group having a larger dipole moment value. More preferably, is used. Specifically, a binder polymer having a functional group having a dipole moment of 4.5 debye or more is preferable, and a binder polymer having a functional group having a dipole moment of 5.0 debye or more is particularly preferable.
The upper limit of the dipole moment of the functional group according to the present invention is preferably 10 or less, more preferably 8.5 or less, and even more preferably 7.0 or less.

  In the calculation of the dipole moment of the functional group in the present invention, a bond linked to the binder polymer from a functional group such as a hydroxyl group, an ester group or an ether group contained in the binder polymer or a functional group formed by combining them. The dipole moment of a compound formed by substituting for hydrogen was determined, and the valence was expressed as the dipole moment of the functional group. The molecular weight of the compound used for calculating the dipole moment is preferably 50 to 300, more preferably 60 to 280, and still more preferably 70 to 250. As the functional group having a dipole moment of 3.8 Debye or more, functional groups represented by the following general formulas (1) to (5) are preferable.

Wherein, X and Y are each _{-C (R 5) (R 6} ) -, - C (R 5) =, - O -, - S -, - N (R 5) - or an -N =, Z ₁ represents O or S, Z ₂ represents O or a lone pair, and Z ₃
-C is _{(R 5) (R 6)} -, - C (R 5) =, - O -, - S -, - N (R 5) - or an -N =. R _{1 to} R ₆ each independently represent a substituent consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon, or any two of them may be bonded to each other. To form a ring. However, at least one of R _{1 to} R ₆ is a divalent linking group linked to a binder polymer skeleton consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon. .

The substituents consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon represented by R _{1 to} R ₆ are —H, —F, —Cl, —Br. , -I,> C <, = C <, ≡C-, -O-, O =, -N <, -N =, ≡N, -S-, S =,> S <, ≡S≡,- P <, ≡P <,> Si <, ═Si <, ≡Si— and monovalent or divalent substituents formed by combining these. Monovalent substituents include hydrogen, alkyl groups [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, 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, tolylthiomethyl group, ethyl Aminoethyl 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, methoxy Carbonylethyl 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-tolylsulfate Moylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methyl Phosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonateoxybutyl 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.], aryl group [eg, 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 , Methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, nitrophenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, phosphonatophenyl group, etc. ], Heteroaryl groups (for example, thiophene, thiathrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, india Eel, Indazole, Purine, Quinolysin, Isoquinoline, Phthalazine, Naphthyridine, Quinazoline, Synoline, Pteridine, Carbazole, Carboline, Phenanthrin, Lysine, perimidine, phenanthrolin, phthalazine, phenazazine, phenoxazine, furazane, phenoxazine, and the like derived from a heterocycle], alkenyl group [eg, vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group 2-chloro-1-ethenyl group etc.], alkynyl group [eg ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group etc.], halogen atom [—F, —Br, —Cl, —I ], A 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-diarylcarbamoyl Oxy 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′-aryl-N-alkylureido group 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 -Aliro Aryloxycarbonyl amino 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 (-SO3H) 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, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group , a phosphono group (-PO ₃ H ₂₎ and its conjugated base group ( Lower, referred to as phosphonato group), a 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 alkyl phosphonate group), monoaryl phosphono group (—PO ₃ H (aryl)) and its conjugate A base group (hereinafter referred to as an aryl phosphonate group), a phosphonooxy group (—OPO ₃ H ₂ ) and a conjugate base group thereof (hereinafter referred to as a phosphonateoxy group), a dialkyl phosphonooxy group (—OPO ₃ ( alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkylphosphonooxy group (—OPO ₃ H ( alkyl)) and The conjugated base group (hereinafter referred to as alkyl phosphonophenyl group), monoaryl phosphonooxy group (-OPO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as aryl phosphite Hona preparative group), a cyano group A hydrogen atom, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a halogen atom, an alkoxy group, and an acyl group.

Examples of the divalent substituent, for _{example, -CX 1 X 2 -, -} CO -, - NX 1 -, - O -, - S -, - PX 1 -, - SiX 1 X 2 -, - CX 1 = _{N -, - SO 2 -,} - CS -, - SO -, - CX 1 = CX 2 -, - C≡C -, - POX 1 - (X 1 ~X 2 is a monovalent substituent described above And a substituent formed by combining them. In the case of a divalent substituent, the functional group has a cyclic structure. A divalent substituent in which the cyclic structure is a 4- to 8-membered ring is preferable. The cyclic structure may be saturated or unsaturated, and may further have a condensed ring.

For example, in the general formula (1), X = —C (R ₅ ) (R ₆ ) — (where R ₅ represents a hydrogen atom, R ₆ represents a connecting site with a binder polymer), Z ₁ ═O, Y = —C (R ₅ ) = (where R ₅ and R ₁ together represent — (CH ₂ ) ₃ —), and the functional group where R ₂ ═O is 2,3-dioxo-1 -A cyclohexyl group.

Among these functional groups, a functional group having a cyclic structure is preferable, and a functional group having a cyclic structure is particularly preferable. In the general formula (1), X = —O—, —S—, or —N (R ₅ )-, Y = -O-, -S- or -N (R ₅ )-, a functional group consisting of Z ₁ = O or S, in formula (2), X = -O-, -S- or -N (R ₅ ) —, Y = —O—, —S— or —N (R ₅ ) —, Z ₂ ═O or a functional group comprising a lone pair, X = —O— or — in the general formula (3) C (R ₅ ) (
R ₆ ) —, Y = —O— or —C (R ₅ ) (R ₆ ) —, Z ₃ = —O— or —C (R ₅ ) (R ₆ ) —.

More preferably, it has a cyclic structure and (X, Y, Z ₁ ) = (— O—, —O—, O), (—O—, —N (R ₅ ) in the general formula (1). -, O), (- O -, - C (R 5) (R 6) -, O), (- N (R 5) -, - N (R 5) -, O), (- S-, A functional group consisting of —N (R ₅ ) —, O), in the general formula (2), (X, Y, Z ₂ ) = (— O—, —O—, O), (—O—, —N ( R ₅ )-, O), (—O—, —C (R ₅ ) (R ₆ ) —, O), (—N (R ₅ ) —, —N (R ₅ ) —, O) Group, (X, Y, Z ₃ ) = (— O—, —O—, O), (—O—, —O—, —C (R ₅ ) (R ₆ ) —) in the general formula (3) Is a functional group consisting of

  The specific example of the compound which forms the functional group used for this invention below is shown. The present invention is not limited to these.

  The binder polymer used in the present invention is a polymer compound having a functional group having a dipole moment of 3.8 debyes or more and an acid value of 0.3 meq / g or less. The polymer compound is preferably a polymer compound selected from an acrylic resin, a methacrylic resin, a styrene resin, a vinyl acetal resin, a urethane resin, a urea resin, an amide resin, an ester resin, a carbonate resin, and an epoxy resin, and an acrylic resin and a urethane resin. Is more preferable. The binder polymer used in the present invention can be produced by polymerizing a polymerization component having a functional group having a dipole moment of 3.8 debyes or more.

  Specific examples of the polymerization component having a functional group having a dipole moment of 3.8 debyes or more used in the present invention are shown as repeating units. The present invention is not limited to these. In the following specific examples, U-1 to U-150 are repeating units suitable for forming acrylic resins, methacrylic resins, styrene resins, and the like, and V-1 to V-53 are urethane resins and urea resins. , A repeating unit suitable for forming an amide resin, an ester resin, a carbonate resin or the like.

  Said polymerization component may be used independently and may use 2 or more types together. Moreover, the binder polymer used for this invention can contain the polymerization component which does not have a functional group whose dipole moment is 3.8 debye or more, unless the effect of this invention is impaired.

Furthermore, the binder polymer used in the present invention can be cross-linked in order to improve the film strength of the image area.
In order to give the binder polymer crosslinkability, a crosslinkable functional group 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 functional group is a group that crosslinks the binder polymer in the process 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, As such a crosslinkable functional 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 (A)-(C) is especially preferable.

In the general formula (A), R ^{1 to} R ³ each independently represents a hydrogen atom or a monovalent organic group. R ¹ preferably includes a hydrogen atom or an alkyl group which may have a substituent. Among them, 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, a substituted group An aryl group that may have a group, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that 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 ) —, and 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 (B), R ^{4 to} R ⁸ each independently represent a hydrogen atom or a monovalent organic group. R ^{4 to} R ⁸ are preferably 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, an alkyl group which may have a substituent, An aryl group that may have a substituent, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that 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 group and an aryl group which may have a substituent are preferable.

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

In the general formula (C), R ⁹ preferably 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 ⁹ is preferably a hydrogen atom or a methyl group 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, a substituent An arylamino group that may have, an alkylsulfonyl group that may have a substituent, an arylsulfonyl group that may have a substituent, and the like, 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, as a substituent which can be introduce | transduced, the thing similar to general formula (A) is illustrated. Z represents an oxygen atom, a sulfur atom, —N (R ¹³ ) —, or an optionally substituted phenylene group. 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.

In the case of a binder polymer having crosslinkability, for example, free radicals (polymerization initiation radicals or growth radicals in the polymerization process of a polymerizable compound) are added to the crosslinkable functional group, and a polymerization chain of a polymerizable compound is formed directly between polymers. Through addition polymerization, a cross-link is formed between the polymer molecules and cured. Alternatively, atoms in the polymer (for example, hydrogen atoms on carbon atoms adjacent to the crosslinkable functional group) are extracted by free radicals to form polymer radicals that are bonded to each other, thereby causing crosslinking between polymer molecules. Forms and cures.
The content of the crosslinkable functional group in the binder polymer used in the present invention (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol per 1 g of the binder polymer. More preferably, it is 1.0-7.0 mmol, Most preferably, it is 2.0-5.5 mmol.

In addition, it is preferable that the binder polymer is hydrophilic from the viewpoint of improving developability with respect to an aqueous solution, and it is important that the binder polymer is compatible with the polymerizable compound contained in the photosensitive layer from the viewpoint of improving the film strength. That is, it is preferably lipophilic. From this point of view, in the present invention, it is also effective to contain a unit having a hydrophilic group and a unit having a lipophilic group in the binder polymer in order to further improve developability and film strength. Examples of the unit having a hydrophilic group include a hydroxy group, a carboxylate group, a hydroxyethyl group, an ethyleneoxy group, a hydroxypropyl group, a polyoxyethyl group, a polyoxypropyl group, an amino group, an aminoethyl group, and an aminopropyl group. And those having a hydrophilic group such as an ammonium group, an amide group, or a carboxymethyl group.

  Below, the specific example of the polymerization component which does not have a functional group whose dipole moment used for this invention is 3.8 debye or more is described. The present invention is not limited to these.

In the binder polymer used in the present invention, the content of the polymerization component (repeating unit) having a functional group having a dipole moment of 3.8 debye or more is preferably more than 20 mol%, more preferably more than 30 mol%. More preferred. By making it more than 20 mol%, a practically sufficient radical polymerization promoting effect can be obtained.
Specific examples of the binder polymer used in the present invention are shown below. The present invention is not limited to these.

  By using a specific binder polymer having a functional group having a dipole moment of 3.8 debye or more and an acid value of 0.3 meq / g or less, the polarity and hydrophilicity of the photosensitive layer can be improved. As a result, the radical polymerization reaction is stabilized by the polarity, the polymerization rate is increased, the sensitivity and the printing durability are improved, and the developability with an aqueous solution having a pH of 10 or less is improved by the hydrophilic property.

The binder polymer used in the present invention 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 25. More preferably, it is 10,000. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The binder polymer used in the present invention may be any of a random polymer, a block polymer, a graft polymer, etc., but is preferably a random polymer.

The binder polymer used in the present invention may be used alone or in combination of two or more. Moreover, unless the effect of this invention is impaired, it can use together with the binder polymer which does not have a functional group whose dipole moment is 3.8 debyes or more.
Content of the binder polymer used for this invention is 5-90 mass% with respect to the total solid of a photosensitive layer, It is preferable that it is 10-70 mass%, and it is 10-60 mass%. More preferred. Within this range, good image area strength and image formability can be obtained.

Next, components other than the binder polymer contained in the photosensitive layer provided on the support of the lithographic printing plate precursor according to the invention will be described in detail.
[Radically polymerizable compound]
The radically polymerizable compound (hereinafter, also simply referred to as “polymerizable compound”) used in the photosensitive layer in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and has at least a terminal ethylenically unsaturated bond. It is selected from compounds having one, preferably two or more. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. 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 a monofunctional or polyfunctional compound. A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. In addition, 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 vinyl urethane 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 (X) to a polyisocyanate compound having two or more isocyanate groups Etc.

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

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56- Urethane compounds having an ethylene oxide skeleton described in Japanese Patent No. 17654, Japanese Patent Publication No. 62-39417, and Japanese Patent Publication No. 62-39418 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 the polymerizable compound, 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.

  The polymerizable compound is used in an amount of preferably 5 to 80% by mass, more preferably 25 to 75% by mass, based on the total solid content of the photosensitive layer. Moreover, a polymeric compound may be used independently or may be used together 2 or more types. In addition, the usage of the polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging, refractive index change, surface adhesiveness, etc. The layer construction and coating method such as undercoating and overcoating can be carried out.

[Radical polymerization initiator]
The radical polymerization initiator used in the photosensitive layer of the present invention is a compound that initiates and accelerates polymerization of a compound having a polymerizable unsaturated group by generating radicals by light or thermal energy. Such a radical polymerization initiator can be appropriately selected from known radical polymerization initiators and compounds having a bond having a small bond dissociation energy.
Examples of the radical polymerization initiator include organic halogen compounds, carbonyl compounds, organic peroxides, azo compounds, azide compounds, metallocene compounds, hexaarylbiimidazole compounds, organic boron compounds, disulfone compounds, oxime ester compounds, oniums. A salt compound is mentioned.

  Specific examples of the organic halogen compound include Wakabayashi et al., “Bull Chem. Soc Japan” 42, 2924 (1969), US Pat. No. 3,905,815, Japanese Patent Publication No. 46-4605, JP 48-36281, JP 53-133428, JP 55-3070, JP 60-239736, JP 61-169835, JP 61-169837, JP 62- 58241, JP-A 62-212401, JP-A 63-70243, JP-A 63-298339, P. The compound as described in Hutt, "Journal of Heterocyclic Chemistry", 1 (No. 3) (1970) is mentioned. Of these, oxazole compounds and S-triazine compounds substituted with a trihalomethyl group are preferred.

  More preferable examples include s-triazine derivatives in which at least one mono, di, or trihalogen-substituted methyl group is bonded to the s-triazine ring, and oxadiazole derivatives in which the oxadiazole ring is bonded. Specifically, for example, 2,4,6-tris (monochloromethyl) -s-triazine, 2,4,6-tris (dichloromethyl) -s-triazine, 2,4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-bis (trichloromethyl) -s-triazine, 2-n-propyl-4,6-bis (trichloromethyl) -s-triazine, 2- (α, α, β-trichloroethyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3,4-epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- [1- (P-methoxyphenyl) -2,4-butadienyl] -4,6-bis (trichloromethyl) -s-triazine, 2-styryl-4,6-bis (trichloromethyl) -s-triazine, 2- ( -Methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (pi-propyloxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p- Tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2-phenylthio-4,6-bis ( Trichloromethyl) -s-triazine, 2-benzylthio-4,6-bis (trichloromethyl) -s-triazine, 2,4,6-tris (dibromomethyl) -s-triazine, 2,4,6-tris ( Tribromomethyl) -s-triazine, 2-methyl-4,6-bis (tribromomethyl) -s-triazine, 2-methoxy-4,6-bis (tribromomethyl) Etc. -s- triazine and the following compounds.

  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.

  As the azo compound, for example, an azo compound described in JP-A-8-108621 can be used.

  Examples of the organic peroxide include trimethylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butyl). Peroxy) cyclohexane, 2,2-bis (tert-butylperoxy) butane, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydro Peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, tert-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2, -Oxanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate , Dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, tert- Butyl peroxyoctanoate, tert-butyl peroxylaurate, tersyl carbonate, 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4 ′ − Tra- (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyl And di (t-hexylperoxydihydrogen diphthalate).

  Examples of the metallocene compound include JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, JP-A-2-4705, Various titanocene compounds described in JP-A-5-83588, such as di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, Di-cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1-yl, di- -Cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,4,5,6-penta Fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4,6-trifluoropheny -1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4 , 5,6-pentafluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyr-1-yl) phenyl) titanium, JP-A-1-304453, Examples thereof include iron-arene complexes described in JP-A-1-152109.

Examples of the hexaarylbiimidazole compound include the specifications of JP-B-6-29285, US Pat. Nos. 3,479,185, 4,311,783, and 4,622,286. And, specifically, 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) ) Bididazole, 2,2′-bis (o, o′-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-nitrophenyl) -4,4 ′ , 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4 '
, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, and the like.

  Examples of the organoboron compound include JP-A-62-143044, JP-A-62-1050242, JP-A-9-188585, JP-A-9-188686, JP-A-9-188710, JP-A 2000-. No. 131837, Japanese Patent Application Laid-Open No. 2002-107916, Japanese Patent No. 2764769, Japanese Patent Application Laid-Open No. 2002-116539, and Kunz, Martin “Rad Tech '98. Proceeding April 19-22, 1998, Chicago”, etc. Organic borate salts described in JP-A-6-157623, JP-A-6-175564, JP-A-6-175561, and organic boron oxosulfonium complexes, JP-A-6-175554 Japanese Laid-Open Patent Publication No. 6-175553 Organoboron iodonium complexes described in Japanese Patent Laid-Open No. 9-188710, organoboron phosphonium complexes described in JP-A-9-188710, JP-A-6-348011, JP-A-7-128785, JP-A-7-140589, JP Examples thereof include organoboron transition metal coordination complexes such as 7-306527 and JP-A-7-292014.

  Examples of the disulfone compound include compounds described in JP-A Nos. 61-166544 and 2003-328465.

  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. Specific examples include compounds represented by the following structural formula.

  Examples of the onium salt compound include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Bal et al, Polymer, 21, 423 (1980), ammonium salts described in US Pat. No. 4,069,055, JP-A-4-365049, etc., US Pat. No. 4,069 , 055, 4,069,056, phosphonium salts described in European Patent Nos. 104,143, U.S. Pat. Nos. 339,049, 410,201,580, , 604,581 specification, J. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. CuringASIA, p478 Tokyo, Oct (1988) and onium salts such as arsonium salts.

  In the present invention, these onium salts function not as acid generators but as ionic radical polymerization initiators.

The onium salts preferably used in the present invention are represented by the following general formulas (RI-I) to (RI-II).
An onium salt represented by I).

In the formula (RI-I), Ar ₁₁ represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include an alkyl group having 1 to 12 carbon atoms and a carbon number. 1-12 alkenyl group, C1-C12 alkynyl group, C1-C12 aryl group, C1-C12 alkoxy group, C1-C12 aryloxy group, halogen atom, C1-C1 12 alkylamino groups, C1-C12 dialkylamino groups, C1-C12 alkylamide groups or arylamide groups, carbonyl groups, carboxyl groups, cyano groups, sulfonyl groups, C1-C12 thioalkyl groups And a thioaryl group having 1 to 12 carbon atoms. Z ₁₁ ^- represents a monovalent anion, specifically a halogen ion, a perchlorate ion, a hexafluorophosphate ion, a tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, and sulfate ion. Of these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion and sulfinate ion are preferable from the viewpoint of stability.

In the formula (RI-II), Ar ₂₁ and Ar ₂₂ each independently represent an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include 1 to 1 carbon atoms. 12 alkyl groups, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 1 to 12 carbon atoms, Halogen atom, C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl group, cyano group, sulfonyl group, carbon Examples thereof include a thioalkyl group having 1 to 12 carbon atoms and a thioaryl group having 1 to 12 carbon atoms. Z ₂₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoint of stability and reactivity.

In the formula (RI-III), R ₃₁ , R ₃₂ and R ₃₃ are each independently an aryl group, alkyl group, alkenyl group or alkynyl having 20 or less carbon atoms, which may have 1 to 6 substituents. Represents a group. Among them, an aryl group is preferable from the viewpoint of reactivity and stability. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, Aryloxy group having 1 to 12 carbon atoms, halogen atom, alkylamino group having 1 to 12 carbon atoms, dialkylamino group having 1 to 12 carbon atoms, alkylamide group or arylamide group having 1 to 12 carbon atoms, carbonyl group, carboxyl Group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms. Z ₃₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Of these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoints of stability and reactivity. More preferred are the carboxylate ions described in JP-A No. 2001-343742, and particularly preferred are the carboxylate ions described in JP-A No. 2002-148790.

The radical polymerization initiator is not limited to the above, but particularly from the viewpoint of reactivity and stability, triazine initiators, organic halogen compounds, metallocene compounds, hexaarylbiimidazole compounds, organic boron compounds, oxime ester compounds, onium salts. Compounds are preferable, and triazine-based initiators, organic halogen compounds, metallocene compounds, hexaarylbiimidazole compounds, and onium salt compounds are more preferable.
The radical polymerization initiator is preferably added in an amount of 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, and particularly preferably 0.8 to 20% by mass with respect to the total solid content of the photosensitive layer. Can do.

  In addition, the photosensitive layer of the present invention can contain the following compounds as other additives, if necessary, depending on the application.

[Sensitizing dye]
The sensitizing dye used in the photosensitive layer of the present invention is appropriately selected depending on the use and the like, and is not particularly limited. For example, the sensitizing dye absorbs light of an infrared absorber or 360 nm to 450 nm. Examples thereof include sensitizing dyes.

<Infrared absorber>
An infrared absorber is a component used to increase sensitivity to an infrared laser. The infrared absorber has a function of converting absorbed infrared rays into heat. The infrared absorber used in the present invention is preferably a dye or pigment having an absorption maximum at a wavelength of 760 to 1200 nm.

  As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, etc. Is mentioned.

  Examples of preferable dyes include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, Methine dyes described in JP-A Nos. 58-181690 and 58-194595, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, JP-A Naphthoquinone dyes described in JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., squarylium dyes described in JP-A-58-112792, etc., British Patent No. And cyanine dyes described in the specification of 434,875.

  In addition, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also suitable. ) Pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59- No. 41363, 59-84248, 59-84249, 59-146063, 59-146061, pyranyl compounds described in JP-A-59-216146, cyanine dyes described in US It is disclosed in the pentamethine thiopyrylium salt described in Japanese Patent No. 4,283,475, and Japanese Patent Publication Nos. 5-13514 and 5-19702. Pyrylium compounds are also preferably used. Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).

  Other preferable examples of the infrared absorbing dye include specific indolenine cyanine dyes described in JP-A-2002-278057 as exemplified below.

  Particularly preferred among these dyes are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferred, and one particularly preferred example is a cyanine dye represented by the following general formula (I).

In the general formula (I), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below. Here, X ² represents an oxygen atom, a nitrogen atom, or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or 1 to 1 carbon atom containing a hetero atom. 12 hydrocarbon groups are shown. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se.

（式中、Ｘａ^-は後述するＺａ^-と同義であり、Ｒ^aは、水素原子、アルキル基、アリール
基、置換又は無置換のアミノ基、ハロゲン原子より選択される置換基を表す。）

(Wherein, Xa ^- is Za described later ^- is synonymous with, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.)

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the photosensitive layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring or It is particularly preferable that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Za ⁻ represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by formula (I) has an anionic substituent in its structure and neutralization of charge is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a hexagonal salt, in view of storage stability of the photosensitive layer coating solution. Fluorophosphate ion and aryl sulfonate ion.

  Specific examples of the cyanine dye represented by formula (I) that can be suitably used in the present invention include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. be able to.

  Further, other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057 described above.

  Examples of the pigment used in the present invention include commercially available pigments and color index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technology Association, published in 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986), “Printing Ink Technology”, CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments , Loso pigments, nitro pigments, natural materials, fluorescent pigments, inorganic pigments, carbon black and the like can be used. Among these pigments, carbon black is preferable.

  These pigments may be used without surface treatment, or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle diameter of the pigment is preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.05 to 1 μm, and particularly preferably in the range of 0.1 to 1 μm. Within this range, good stability and uniformity of the pigment dispersion in the photosensitive composition can be obtained.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

  These infrared absorbers can be added by being encapsulated in microcapsules.

As the addition amount, it is preferable to add so that the absorbance at the maximum absorption wavelength in the wavelength range of 760 nm to 1200 nm of the photosensitive layer is in the range of 0.3 to 1.3 by the reflection measurement method, more preferably, It is in the range of 0.4 to 1.2. Within this range, a uniform polymerization reaction proceeds in the depth direction of the photosensitive layer, and good film strength of the image area and adhesion to the support can be obtained.
The absorbance of the photosensitive layer can be adjusted by the amount of infrared absorber added to the photosensitive layer and the thickness of the photosensitive layer. Absorbance can be measured by a conventional method. As a measuring method, for example, on a reflective support such as aluminum, a photosensitive layer having a thickness appropriately determined in a necessary range as a lithographic printing plate precursor after drying is formed, and the reflection density is measured as an optical density. And a method of measuring with a spectrophotometer by a reflection method using an integrating sphere.

<Sensitizing dye that absorbs light of 360 nm to 450 nm>
Examples of the sensitizing dye that absorbs light of 360 nm to 450 nm include merocyanine dyes represented by the following general formula (I), benzopyrans represented by the following general formula (II), coumarins, and 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 monovalent non-metallic atomic group, and Y represents a non-nuclear group that forms a basic nucleus of a dye together with an adjacent A and an adjacent carbon atom. Represents a metal atom group, X ₁ and X ₂ each independently represent a monovalent non-metal atom group, or X ₁ and X ₂ may be bonded to each other to form an acidic nucleus of the dye.)

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

(In the formula, Ar ₃ represents an aromatic group or a heteroaromatic group which may have a substituent, and R ₁₃
Represents a monovalent nonmetallic atomic group. R ₁₃ is more preferably an aromatic group or a heteroaromatic group, and 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 monovalent non-metallic atomic group, and more preferable X ₃ and X ₄ are electron donating groups having a negative Hammett's substituent constant. .)
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 a hydrogen atom, an alkyl group (for example, a 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, 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 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, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonyl Methyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfofe 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, tolylphos Phonohexyl 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-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, phenoxycarbonylphenyl group, N-phenylcarba Moylphenyl group, nitrophenyl 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, indoazole, purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, sinoline, pteridine , Carbazole, carboline, phenanthrine, acridine, perimidine, phenanthroline, phthalazine, phenazazine, phenoxazine, furazane, phenoxazine, etc. A group derived from a terror ring), an 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, alkyl Dithio 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-dialkylcarbamoyl Xyl group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacyl Amino 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-a Rukyureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxy Carbonylamino 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, alkyl Rufiniru group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugated base group (hereinafter referred to as sulfonato group), alkoxy sulfonyl group, aryloxy sulfonyl 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, 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), di Rukiruhosufono 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 alkyl phosphonate group), monoaryl phosphono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as aryl phosphonate group) ), Phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonatoxy group), dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylaryl phosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkyl phosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group , Alkylho Fonatookishi referred to as group), monoaryl phosphonooxy group (-OPO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as aryl phosphite Hona preparative group), a cyano group, a nitro group, etc., and more Of these groups, a hydrogen atom, an alkyl group, an aryl group, a halogen atom, an alkoxy group, and an acyl group are particularly preferable.

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

Examples of nitrogen-containing heterocycles include those constituting the basic nucleus in merocyanine dyes described in, for example, LGBrooker et al., J. Am. Chem. Soc., 73, 5326-5358 (1951) and references Any of those known as 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 (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-methoxybenzo Thiazole, 6-methoxybenzothia Sol, 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'-methoxy Sithianaphtheno-7 ′, 6 ′, 4,5-thiazole, etc.), 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- Droxybenzoxazole etc.), naphthoxazoles (eg naphtho [1,2] oxazole, naphtho [2,1] oxazole etc.), selenazoles (eg 4-methylselenazole, 4-phenylselenazole etc.), Benzoselenazoles (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-chloro Norin, 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-dialkylindolenines (for example, 3,3-dimethylindolenine, 3,3,5-trimethylindolenine, 3,3 , 7, -trimethylindolenine), pyridines (for example, pyridine, 5-methylpyridine, etc.), and the like.

Examples of the sulfur-containing heterocycle include a dithiol partial structure in dyes described in JP-A-3-296759.

Specific examples include benzodithiols (eg, benzodithiol, 5-t-butylbenzodithiol, 5-methylbenzodithiol, etc.), naphthodithiols (eg, naphtho [1,2] dithiol, naphtho [2,1] Dithiols, etc.), dithiols (for example, 4,5-dimethyldithiols, 4-phenyldithiols, 4-methoxycarbonyldithiols, 4,5-dimethoxycarbonyldithiols, 4,5-ditrifluoromethyldithiols, 4, Examples include 5-dicyanodithiol, 4-methoxycarbonylmethyldithiol, 4-carboxymethyldithiol, and the like.

  As mentioned above, the description used for the description of the heterocyclic ring described above has conventionally used the name of the heterocyclic mother skeleton for convenience, but in the case of the basic skeleton partial structure of the sensitizing dye, for example, in the case of the benzothiazole skeleton , 3-substituted-2 (3H) -benzothiazolidene groups are introduced in the form of alkylidene-type substituents with one degree of unsaturation lowered.

  Of the sensitizing dyes as compounds having an absorption maximum in the wavelength range of 360 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 the general formula (V), A represents an aromatic ring group 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 monovalent nonmetallic atomic group, and A and R ₁ or R ₂ and R ₃ are bonded to each other to form an aliphatic or aromatic ring. May be good.)
The general formula (V) will be described in more detail. R ₁ , R ₂ and R ₃ are each independently a monovalent nonmetallic atomic group, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group. Represents a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a hydroxyl group, or 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, A t-butyl group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a cyclopentyl group, and a 2-norbornyl group can be exemplified. 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 excluding hydrogen is used, and preferred examples include halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups, alkoxy groups, 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, Ruthio 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-aryl Ureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl-N-aryl Ureido 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-ary Ureido 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 , Sulfonato Group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfina Moyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfur Famoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonate group), dialkyl phosphono group (—PO ₃ (alkyl)) _2), diaryl phosphono group (-PO ₃ (aryl) _2), alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )), monoalkyl Sufono group (-PO ₃ H (alkyl)) and its conjugated base group (hereinafter referred to as alkyl phosphonophenyl group), monoaryl phosphono group (-PO ₃ H (aryl)) and its conjugated base group (hereinafter, aryl Phosphonate group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonateoxy group), dialkyl phosphonooxy group (—OPO ₃ (alkyl) ₂ ), diaryl Phosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylaryl phosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkyl phosphonooxy group (—OPO ₃ H (alkyl)) and conjugation thereof A base group (hereinafter referred to as an alkylphosphonatooxy group), a monoarylphosphonooxy group (—OPO ₃ H (aryl)) and a conjugated base group thereof (hereinafter referred to as an arylphosphonatooxy group), Examples include a cyano group, a nitro group, an aryl group, a heteroaryl group, an alkenyl group, and an alkynyl 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, nitropheny Group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, phosphonatophenyl group and the like.

As the heteroaryl group, a monocyclic or polycyclic aromatic ring group containing at least one of nitrogen, oxygen and sulfur atoms is used. Examples of particularly preferred heteroaryl groups include, 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, cynoline, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanthroline, phthalazine, phenazazine, phenoxazine, furazane, phenoxazine, etc. Groups derived are exemplified by these may be further benzo-fused or may have a substituent.

Examples of alkenyl groups include vinyl, 1-propenyl, 1-butenyl, cinnamyl, 2-chloro-1-ethenyl, etc. Examples of alkynyl include ethynyl, 1- A propynyl group, a 1-butynyl group, a trimethylsilylethynyl group, etc. are mentioned. Examples of G ₁ in the acyl group (G ₁ CO—) include the above alkyl groups and aryl groups. Of these substituents, halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, N, N— Dialkylamino 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 Group, N-arylsulfamoyl 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, phosphonooxy group, A phosphonatooxy group, an aryl group, and an alkenyl group are mentioned.

  On the other hand, examples of the alkylene group in the substituted alkyl group include divalent organic residues obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. Can include linear alkylene groups having 1 to 12 carbon atoms, branched chains 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, methoxymethyl 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, 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, tolylphosphono Xyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonatooxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, allyl Group, 2-butenyl group, 2-methylallyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, and the like.

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, a fluorenyl group, and the like. 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 excluding hydrogen 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, carboxy Enyl 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, diphenylphosphonophenyl group, methylphosphine Ionophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonophenyl group, allylphenyl group, 1-propenylmethylphenyl group, 2-butenylphenyl group, 2-methylallylphenyl group, 2-methylpropenyl A phenyl group, 2-propynylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group and the like can be mentioned.

Examples of preferred alkenyl and heteroaryl groups for R ₁ , R ₂ and R ₃ include
Examples thereof include those similar to the alkenyl group and heteroaryl group described above as the substituent of the substituted alkyl group.

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

The sensitizing dye represented by the general formula (V) is obtained by a condensation reaction between an acidic nucleus having an acidic nucleus or an active methylene group as shown above and a substituted or unsubstituted aromatic ring or heterocyclic ring. It is done. Specifically, it can be synthesized with reference to the description of JP-B-59-28329.

  Preferred specific examples (D1) to (D41) of the compound represented by the general formula (V) are shown below. In addition, an isomer with a double bond connecting an acidic nucleus and a basic nucleus is not limited to either isomer.

  The sensitizing dye that absorbs light of 360 nm to 450 nm is preferably used in the range of 1.0 to 10.0% by mass in all components of the photosensitive layer. More preferably, it is the range of 1.5-5.0 mass%.

[Co-sensitizer]
The sensitivity of the photosensitive layer of the present invention can be further improved by using certain additives. Such a compound is referred to as a co-sensitizer in the present invention. These mechanisms of action are not clear, but many are thought to be based on the following chemical processes. That is, co-intensification with various intermediate active species (radicals, peroxides, oxidizing agents, reducing agents, etc.) generated in the course of the photoreaction initiated by light absorption of the polymerization initiation system and the subsequent addition polymerization reaction. It is presumed that the sensitizer reacts to generate new active radicals. The co-sensitizers are roughly classified into (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.
Ferrocene and iron arene complexes: An active radical can be reductively generated.

(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, after reacting 2-alkyl-1- [4- (alkylthio) phenyl] -2-morpholinopronone-1 and these with a hydroxyamine, N-OH was etherified. Examples include oxime ethers.
Sulfinic acid salts: An active radical can be reductively generated. Specific examples include sodium arylsulfinate.

(C) Compounds that react with radicals to convert to highly active radicals or act as chain transfer agents Compounds that react with radicals to convert to highly active radicals or act as chain transfer agents include, for example, SH, PH in the molecule , SiH, and GeH are used. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals. Specifically, 2-mercaptobenzimidazoles etc. are mentioned, for example.

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

  These cosensitizers can also be subjected to various chemical modifications for improving the characteristics of the photosensitive layer of the present invention, as in the case of the above sensitizing dyes. For example, sensitizing dyes, polymerization initiators, polymerizable compounds, bonds with other radical generating parts, introduction of hydrophilic sites, compatibility improvement, introduction of substituents to suppress crystal precipitation, substituents that improve adhesion Methods such as introduction and polymerization can be used. These co-sensitizers can be used alone or in combination of two or more. The amount used is suitably 0.05 to 100 parts by weight, preferably 1 to 80 parts by weight, and more preferably 3 to 50 parts by weight with respect to 100 parts by weight of the polymerizable compound.

[Surfactant]
In the photosensitive layer of the present invention, it is preferable to use a surfactant 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 photosensitive layer of the present invention, a hydrophilic polymer can be contained in order to improve developability and microcapsule dispersion stability.
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 , Homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, 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 photosensitive layer of the present invention, a dye having a large absorption in the visible light region can be added with 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 addition amount is preferably 0.01 to 10% by mass with respect to the total 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 use or storage.
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 coating 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 excellent in hydrophilicity, which is stably dispersed in the photosensitive layer, sufficiently retains the film strength, 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 compounds]
The photosensitive layer of the present invention may contain a low molecular weight hydrophilic compound for improving developability. As the low molecular weight hydrophilic compound, for example, as the water-soluble organic compound, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like glycols 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 Examples thereof include organic carboxylic acids such as salts thereof, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, and amino acids, and salts thereof.

[Formation of photosensitive layer]
Several modes can be used as a method for forming the photosensitive layer. One is an embodiment in which the constituent components of the photosensitive layer are dissolved and applied in a suitable solvent as described in JP-A-2002-287334, and the other is, for example, JP-A-2001-277740. As described in Japanese Patent Application Laid-Open No. 2001-277742, it is an embodiment (microcapsule type photosensitive layer) in which the constituent components of the photosensitive layer are encapsulated in microcapsules and contained in the photosensitive layer. Further, in the microcapsule type photosensitive layer, the constituent component can be contained outside the microcapsule. In the microcapsule type photosensitive layer, it is a more preferable embodiment that a hydrophobic constituent component is encapsulated in the microcapsule and a hydrophilic constituent component is contained outside the microcapsule.

  As a method for microencapsulating the above photosensitive layer constituent components, known methods can be applied. For example, as a method for producing microcapsules, a method using coacervation found in U.S. Pat. Nos. 2,800,547 and 2,800,498, U.S. Pat. No. 3,287,154, JP-B-38-19574, 42-446 by the interfacial polymerization method, US Pat. No. 3,418,250, US Pat. No. 3,660,304 by polymer precipitation method, US Pat. No. 3,796,669, isocyanate polyol A method using a wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, and a urea-formaldehyde system found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802. Or urea formaldehyde-resorcinol A method using a wall forming material, a method using a wall material such as melamine-formaldehyde resin, hydroxycellulose, etc. found in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method by monomer polymerization, spray drying method found in British Patent No. 930422, US Pat. No. 3,111,407, electrolytic dispersion cooling method seen in British Patent Nos. 952807, 967074, etc. However, it is not limited to these.

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. Further, a compound having a crosslinkable functional group such as an ethylenically unsaturated bond capable of introducing the binder polymer may be introduced into the microcapsule wall.
The average particle size of the microcapsules is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is further more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, good resolution and stability over time can be obtained.
In the present invention, it is also possible to adopt a mode in which each component of the above-described photosensitive layer, particularly preferably the above-mentioned infrared absorber is encapsulated in resin fine particles.
Such an embodiment is achieved by preparing a resin fine particle dispersion obtained by dissolving each component in a solvent and then mixing it with a polymer solution (preferably a polymer aqueous solution) and a homogenizer or the like. it can.

Examples of the solvent that can be used at this time include ethyl acetate, methyl ethyl ketone (MEK), diisopropyl ether, dichloromethane, chloroform, toluene, dichloroethane, and mixed solvents thereof.
As the polymer, polyvinyl alcohol (PVA), polyacrylic acid, sodium polyacrylate, polyacrylamide, polymethacrylic acid, sodium polymethacrylate, polymethacrylamide, polystyrene sulfonic acid, sodium polystyrene sulfonate, acrylic acid- Examples include, but are not limited to, a methyl acrylate copolymer, a methacrylic acid-methyl methacrylate copolymer, and a styrene-sodium styrene sulfonate copolymer.
A solvent is used individually or in mixture. 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 photosensitive layer coating amount (solid content) on the support obtained after coating and drying varies depending on the use, but is generally preferably 0.3 to 3.0 g / m ² . 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 has an oxygen permeability A of 1.0 ≦ A ≦ 20 (mL / m ² · day) at 25 ° C. and 1 atm.
) Is preferable. When the oxygen permeability A is extremely low at less than 1.0 (mL / m ² · day), unnecessary polymerization reaction occurs at the time of production and raw storage, and unnecessary fogging and image streaking occur during image exposure. The problem that fatness arises arises. 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 1.5 ≦ A ≦ 12 (mL / m ² · day), and further preferably 2.0 ≦ A ≦ 10.0 (m
L / m ² · day). In addition to the oxygen permeability described above, the properties desired for the protective layer further do not substantially inhibit the transmission of light used for exposure, have excellent adhesion to the photosensitive layer, and are easy in the development process after exposure. 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 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 alcohol / Water-soluble polymers such as vinyl phthalate copolymer, vinyl acetate / crotonic acid copolymer, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, polyacrylic acid, polyacrylamide, etc., may be used alone or in combination Can be used. 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 the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100 mol% and a number of polymerization repeating units 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 anti-fogging properties, 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 higher the film thickness, the higher the oxygen barrier property and the more advantageous in terms of sensitivity. The molecular weight of the polymer compound 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 another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the polymer compound to give flexibility. Also, sodium alkyl sulfate, sodium alkyl sulfonate Anionic surfactants such as: amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers are added to the polymer compound by several mass% be able to.

  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 is likely to occur, and the separated portion 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.

Further, the protective layer in the lithographic printing plate precursor according to the invention preferably contains an inorganic stratiform compound for the purpose of improving the oxygen barrier property and the photosensitive layer surface protective property. Here, the inorganic layered compound is a particle having a thin flat plate 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 Fe (II), Fe (III)
, Mn, Al, Mg, or V, and D is Si or Al. ], Mica group 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. As the synthetic mica, fluorine phlogopite KMg ₃ (AlSi ₃ O ₁₀
) F ₂ , Potassium tetrasilicon mica KMg _2.5 Si ₄ O ₁₀ ) Non-swelling mica such as F ₂ , and Na tetrasilicic mica NaMg _2.5 (Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Swelling mica such as Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , montmorillonite Na or Li hectorite (Na, Li) _1/8 Mg _{2 /} 5Li _1/8 (Si ₄ O ₁₀ ) F ₂ Is mentioned. 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 to 15 mm, 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 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 a photosensitive layer provided on a 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 for 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.
It 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 image forming 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.
Conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, an electrolyte concentration of 1 to 80% by mass solution, a liquid temperature of 5 to 70 ° C., and a current density of 5 to 60 A / 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 lithographic printing plate precursor according to the invention, it is preferable to provide an undercoat layer of a compound containing a polymerizable group on a support. When an undercoat layer is used, the photosensitive layer is provided on the undercoat layer. The undercoat layer reinforces the adhesion between the support and the photosensitive layer in the exposed area, and easily peels the photosensitive layer from the support in the unexposed area, so that developability is improved.

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. Particularly preferred compounds include compounds having a polymerizable group such as a methacryl group and an allyl group and a support-adsorbing group such as a sulfonic acid group, a phosphoric acid group, and a phosphoric acid ester group. A compound having a hydrophilicity-imparting group such as an ethylene oxide group in addition to the polymerizable group and the support-adsorbing group can also be exemplified as a suitable compound.
The coating amount (solid content) of the undercoat layer is preferably 0.1 to 100 mg / m ² ,
More preferably, it is 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 possible to obtain raw materials at low cost by using silicon alkoxy compounds 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 because it is easy to.
[Plate making process]

〔exposure〕
(1) The lithographic printing plate precursor according to the invention is used after imagewise exposure with an infrared laser. Although the infrared laser used in this case is not particularly limited, a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 760 to 1200 nm are preferable. The output of the infrared laser is preferably 100 mW or more. In order to shorten the exposure time, it is preferable to use a multi-beam laser device.
The exposure time per pixel is preferably within 20 μsec. Moreover, it is preferable that irradiation energy amount is 10-300 mJ / cm < ² >.

(2) On the other hand, as a laser light source, 405 nm semiconductor laser, Ar laser, F
A D-YAG laser or the like is used. In recent years, CTP systems equipped with a 405 nm semiconductor laser have become widespread from the viewpoint of system cost and handleability.

  The plate making method of the lithographic printing plate precursor according to the present invention is performed, for example, by a plate making method in which the above lithographic printing plate precursor is exposed using an inner drum exposure apparatus equipped with a light source having an oscillation wavelength in the range of 360 nm to 550 nm. . In the exposure apparatus, the light beam spot shape of the light beam emitted from the light source divides the light beam into an ordinary ray and an extraordinary ray in parallel with an equal amount of light, and the two beam spots are adjacent to each other so that they partially overlap. It is also possible to perform image recording by exposing the light beam spot shape after the lithographic printing plate precursor is placed on an inner drum exposure device.

The plate making process will be further described in detail.
In the present invention, the development process may be performed immediately after the exposure process, but a heat treatment process may be provided between the exposure process and the development process. 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 seconds 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 precursor to be used is easily affected by ambient light in the work environment, the plate making line is preferably shielded from light 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. In order to obtain sufficient printing durability, the overall exposure 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 ° C to 130 ° C, and still more preferably 40 ° C to 120 ° C.

[Printing method]
In the case of the above (1) and (2), the lithographic printing plate precursor of the present invention is imagewise exposed with a laser, heated on the whole surface by the above-described method, and then subjected to oil-based ink and water-based without any development processing steps. Ingredients can be supplied and printed.

  Specifically, the lithographic printing plate precursor is exposed with a laser, the entire surface of the plate is heated in an oven, and then mounted and printed on a printing machine without passing through a development processing step. Examples of the method include a method in which after mounting, exposure is performed with a laser on a printing machine, and the entire surface of the plate is heated on the printing machine, and then printing is performed without passing through a development processing step.

  For example, in an embodiment of a negative on-press development type lithographic printing plate precursor, an aqueous component and an oil-based ink are used without image-wise exposure of the lithographic printing plate precursor with a laser and then through a development processing step such as a wet development processing step. In the exposed portion, the photosensitive layer cured by exposure forms an oil-based ink receiving portion having an oleophilic surface. On the other hand, in the unexposed area, the uncured photosensitive layer is dissolved or dispersed and removed by the supplied aqueous component and / or oil-based ink, and a hydrophilic surface is exposed in the area.

As a result, the aqueous component adheres to the exposed hydrophilic surface, and the oil-based ink is deposited on the photosensitive layer in the exposed area, and printing is started. Here, water-based components or oil-based inks may be supplied to the printing plate first, but oil-based ink is first supplied in order to prevent the water-based components from being contaminated by the unexposed photosensitive layer. It is preferable to do this. As the aqueous component and the oil-based ink, a normal fountain solution and printing ink are used.
In this way, the lithographic printing plate precursor is subjected to on-press development on an offset printing machine and used as it is for printing a large number of sheets.

In the case of (1) and (2) above, in the plate making method of the lithographic printing plate precursor according to the present invention, after exposure, by an automatic processor equipped with a rubbing member, in the presence of a developer having a pH of 2 to 10, By rubbing the plate surface with a rubbing member, the photosensitive layer in the non-exposed area is removed to obtain a lithographic printing plate.
That is, after removing the photosensitive layer in the non-exposed part or after removing the photosensitive layer and the protective layer in the non-exposed part at once, it can be set in a printing machine and printed immediately.
Further, such processing in an automatic developing machine has an advantage that it is freed from dealing with development residue derived from the protective layer / photosensitive layer that occurs in the case of on-press development.

  The developer used 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 or the like, or an aqueous solution containing a water-soluble polymer compound is preferable. 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.

  Anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene 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 monoglyceride sulfates Tell 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-anhydrous Examples thereof include partially saponified products of maleic acid copolymers, partially saponified products of olefin-maleic anhydride copolymers, and naphthalene sulfonate formalin condensates. Among these, dialkyl sulfosuccinates, alkyl sulfate esters and alkyl naphthalene sulfonates are particularly preferably used.

  The cationic surfactant 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 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. Amidoethylene oxide adducts, fat and oil ethylene oxide adducts, polypropylene glycol ethylene oxide adducts, dimethylsiloxane-ethylene oxide block copolymers, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymers, and other polyhydric alcohol type glycerol Fatty acid ester, fatty acid ester of pentaerythritol, fatty acid ester of sorbitol and sorbitan Fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines.
Among these, sorbitol and / or sorbitan fatty acid ester ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymer, fatty acid of polyhydric alcohol Esters are more preferred.

From the viewpoint of stable solubility or turbidity in water, the nonionic surfactant used in the developer preferably has an HLB (Hydrophile-Lipophile Balance) value of 6 or more, preferably 8 or more. It is more preferable.
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, a nonionic surfactant is particularly suitable from the viewpoint of foam suppression.
Surfactants may be used alone or in admixture of two or more. The amount of the surfactant in the developer is preferably 0.01 to 20% by mass, more preferably 1 to 15% by mass.

Examples of the water-soluble polymer compound used in the developer include soybean polysaccharide, modified starch, gum arabic, dextrin, fiber derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, pullulan, polyvinyl alcohol and the like Derivatives, polyvinylpyrrolidone, polyacrylamide and acrylamide copolymers, vinyl methyl ether / maleic anhydride copolymers, vinyl acetate / maleic anhydride copolymers, styrene / maleic anhydride copolymers, and the like.

  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 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, it is safe and flammable. From the viewpoint, the concentration of the organic solvent is desirably less than 40% by mass.

  In addition to the above, the developer may contain preservatives, chelate compounds, antifoaming agents, organic acids, inorganic acids, inorganic salts, 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 can be used at any temperature, but is preferably 10 ° C to 50 ° C.

  The developer described above can be used as a developer and developer replenisher for the exposed negative 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, Japanese Patent Laid-Open No. 58-159533 and Japanese Patent Laid-Open No. 3-1
No. 00554 or a metal or plastic grooved material in which brush materials are implanted in rows, such as those described in Japanese Utility Model Publication No. 62-167253, without any gaps in the core plastic or metal roll. A brush roll wrapped around can be used.
Examples of brush materials include plastic fibers (for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6.6 and nylon 6.10, polyacrylics such as polyacrylonitrile and poly (meth) acrylate). , And polyolefin-based synthetic fibers such as polypropylene and polystyrene). For example, fiber diameters of 20 to 400 μm and hair lengths of 5 to 30 mm can be suitably used. .
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. It is preferable to use two or more rotating brush rolls.

  The rotation direction of the rotating brush roll may be the same or opposite to the transport direction of the lithographic printing plate precursor. However, as in the automatic processor exemplified in FIG. When a rotating brush roll is 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 photosensitive 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.

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

  In the process of making a lithographic printing plate from the lithographic printing plate precursor according to the present invention, the entire lithographic printing plate precursor 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, heating before development is preferably performed under mild conditions 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.

  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 a 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 formation, the entire surface may be exposed with an actinic ray such as ultraviolet light to accelerate the curing of the image portion. 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. In order to obtain sufficient printing durability, the overall 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 ° C to 130 ° C, and still more preferably 40 ° C to 120 ° C.

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

[Examples 1 to 4 and Comparative Example 1]
(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.

<Preparation of lithographic printing plate precursors (1) to (5)>
The following undercoat liquid was bar-coated on the support 1 prepared as described above so that the dry coating amount was 10 mg / m ² and then oven-dried at 80 ° C. for 10 seconds to form an undercoat layer.

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

A photosensitive layer coating solution 1 having the following composition was bar coated on the aluminum support provided with the undercoat layer, followed by oven drying at 70 ° C. for 60 seconds to form 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 formed on the coating layer using a bar so that the dry coating amount is 0.75 g / m ^2, and then dried at 125 ° C. for 70 seconds for protection. Layers were formed to obtain lithographic printing plate precursors (1) to (5).

(Photosensitive layer coating solution 1)
・ Binder polymers listed in Table 1 0.54 g
・ Polymerizable compound 0.40g
Isocyanuric acid EO-modified triacrylate (manufactured by Toa Gosei Co., Ltd., Aronix M-315)
・ Polymerizable compound 0.08g
Ethoxylated trimethylolpropane triacrylate (manufactured by Nippon Kayaku Co., Ltd., SR9035, EO addition mole number 15, molecular weight 1000)
・ The following sensitizing dye (1) 0.06 g
・ The following polymerization initiator (1) 0.18 g
・ The following co-sensitizer (1) 0.07 g
.Epsilon.-phthalocyanine pigment dispersion (1) 0.40 g
[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

(1) Exposure, development and printing For each of the above lithographic printing plate precursors (1) to (5), imagewise exposure was performed using a 405 nm semiconductor laser with an output of 100 mW while changing the energy density.
Thereafter, using a developer having the following composition, development processing was performed with an automatic development processor having the structure shown in FIG. 1 to prepare a lithographic printing plate (without heating). 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 transportation of the lithographic printing plate precursor was carried out at various transport speeds.

  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)
・ 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. Thereafter, within 30 seconds, the same development treatment as described above was performed to prepare a lithographic printing plate (with heating).
Next, the lithographic printing plate (without heating) and the lithographic printing plate (with heating) are attached to a printing machine SOR-M manufactured by Heidelberg, and dampening solution (EU-3 (Etchi solution manufactured by Fuji Photo Film Co., Ltd.) / Water. / Isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.) were used for printing at a printing speed of 6000 sheets per hour.

(2) Evaluation The developability, sensitivity, and printing durability of the lithographic printing plate precursor were evaluated as follows. The results are shown in Table 1.

<Developability>
Development was carried out at various conveying speeds as described above, and the cyan density of the non-image area was measured with a Macbeth densitometer. The transport speed at which the cyan density of the non-image area was equal to the cyan density of the aluminum substrate was determined and defined as developability. The evaluation of developability is represented by the relative developability defined as follows using Comparative Example 1 as a reference (1.0). A larger relative developability value indicates higher developability and better performance.
Relative developability = (target photosensitive material transport speed) / (reference photosensitive material transport speed)

<Sensitivity>
After 100 sheets were printed as described above and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were printed continuously. In the total 600th printed matter, the exposure amount with no unevenness in the ink density in the image area was measured as sensitivity. Sensitivity evaluation is represented by the relative sensitivity defined as follows using Comparative Example 1 as a reference (1.0). The larger the relative sensitivity value, the higher the sensitivity and the better the performance.
Relative sensitivity = (sensitivity of standard photosensitive material / sensitivity of target photosensitive material)

<Print durability>
As the number of printed sheets was increased, the photosensitive layer was gradually worn out and the ink acceptability was lowered, so that the ink density in the printing paper was lowered. In the printing plate exposed with the same exposure amount, the 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 evaluation of printing durability is represented by the relative printing durability defined as follows using Comparative Example 1 as a reference (1.0). The larger the relative printing durability number, the higher the printing durability.
Relative printing durability = (printing durability of target photosensitive material) / (printing durability of standard photosensitive material)

[Examples 5 to 20 and Comparative Examples 2 to 9]
<Preparation of lithographic printing plate precursors (6) to (29)>
Lithographic printing plate precursors (6) to (29) were prepared in the same manner as the lithographic printing plate precursor (1) except that the binder polymer of the photosensitive layer coating solution 1 was changed to the binder polymer described in Table 2.
The resulting lithographic printing plate precursors (6) to (29) were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Examples 21 to 30 and Comparative Examples 10 to 13]
<Preparation of lithographic printing plate precursors (30) to (43)>
Except for changing the photosensitive layer coating solution 1 to a photosensitive layer coating solution 2 having the following composition, a lithographic printing plate precursor (
Lithographic printing plate precursors (30) to (43) were prepared in the same manner as in 1).

(Photosensitive layer coating solution 2)
・ Binder polymers listed in Table 3 0.54 g
・ The following polymerizable compound (1) 0.40 g
・ Polymerizable compound 0.08g
Dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., SR399)
-0.06 g of the above sensitizing dye (1)
・ The above polymerization initiator (1) 0.18 g
・ Cosensitizer (1) 0.07g
・ 0.40 g of the above ε-phthalocyanine pigment dispersion (1)
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt / the above-mentioned 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

  The resulting lithographic printing plate precursors (30) to (43) were evaluated in the same manner as in Example 1. The results are shown in Table 3.

[Examples 31-39 and Comparative Examples 14-18]
<Preparation of lithographic printing plate precursors (44) to (57)>
Lithographic printing plate precursors (44) to (57) were prepared in the same manner as the lithographic printing plate precursor (1) except that the photosensitive layer coating solution 1 was changed to the photosensitive layer coating solution 3 having the following composition.

(Photosensitive layer coating solution 3)
・ Binder polymer listed in Table 4 0.54 g
-0.48 g of the following polymerizable compound (2)
-0.06 g of the above sensitizing dye (1)
・ The above polymerization initiator (1) 0.18 g
・ Cosensitizer (1) 0.07g
・ 0.40 g of the above ε-phthalocyanine pigment dispersion
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt / the above-mentioned 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

  The resulting lithographic printing plate precursors (44) to (57) were evaluated in the same manner as in Example 1. The results are shown in Table 4.

[Examples 40 to 47 and Comparative Examples 19 to 21]
<Preparation of lithographic printing plate precursors (58) to (68)>
Lithographic printing plate precursors (58) to (68) were produced in the same manner as the production of the lithographic printing plate precursor (1) except that the photosensitive layer coating solution 1 was changed to the photosensitive layer coating solution 4 having the following composition.

(Photosensitive layer coating solution 4)
・ The above polymerization initiator (1) 0.20 g
-Sensitizing dye (1) 0.10 g
-Binder polymer listed in Table 5 3.00 g
・ Polymerizable compound 6.20 g
Dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., SR399)
・ Royco Crystal Violet 0.20g
-0.10 g of the above fluorosurfactant (1)
・ The following microcapsule dispersion (1) 25.00 g
・ Methyl ethyl ketone 35.00g
・ 1-methoxy-2-propanol 35.00g

(Preparation of microcapsule dispersion (1))
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. The microcapsule liquid thus obtained was diluted with distilled water to a solid content concentration of 20% by mass to obtain a microcapsule dispersion (1). The average particle size of the microcapsules was 0.25 μm.

  The resulting lithographic printing plate precursors (58) to (68) were evaluated in the same manner as in Example 1. The results are shown in Table 5.

[Examples 48 to 52 and Comparative Examples 22 to 23]
<Preparation of lithographic printing plate precursors (69) to (75)>
The photosensitive layer coating solution 1 is changed to a photosensitive layer coating solution 5 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 protective layer dry coating amount is 0.2 g / m ^2. Except to change to
The lithographic printing plate precursors (69) to (75) were obtained in the same manner as the preparation of the lithographic printing plate precursor (1).

(Photosensitive layer coating solution 5)
・ Binder polymer listed in Table 6 0.54 g
・ 0.45 g of the above polymerizable compound (2)
-0.06 g of the above sensitizing dye (1)
・ The above polymerization initiator (1) 0.18 g
・ Cosensitizer (1) 0.07g
・ 0.40 g of the above ε-phthalocyanine pigment dispersion (1)
・ 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.

  The resulting lithographic printing plate precursors (69) to (75) were evaluated in the same manner as in Example 1. The results are shown in Table 6.

[Examples 53-60 and Comparative Examples 24-26]
<Preparation of lithographic printing plate precursors (76) to (86)>
(Preparation of support 2)
Using an aluminum plate according to JIS-A-1050 having a thickness of 0.3 mm, the following steps (a) to (k) were performed in this order to perform surface treatment.

(A) Mechanical surface roughening treatment While supplying a suspension of abrasive (silica sand) having a specific gravity of 1.12 and water as a polishing slurry liquid to a surface of an aluminum plate, it is mechanically rotated by a roller-like nylon brush. Roughening was performed. The average particle size of the abrasive was 8 μm, and the maximum particle size was 50 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (Φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The obtained aluminum plate was sprayed with an aqueous NaOH solution (concentration: 26 mass%, aluminum ion concentration: 6.5 mass%) at a temperature of 70 ° C. to dissolve the aluminum plate by 6 g / m ^2. did. Thereafter, washing with water was performed using well water.

(C) Desmutting treatment The desmutting treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. As the nitric acid aqueous solution used for the desmut treatment, the waste liquid of the following (d) electrochemical surface roughening treatment step was used.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a nitric acid 10.5 g / liter aqueous solution (aluminum ion 5 g / liter) at a temperature of 50 ° C. The AC power supply waveform has an electrochemical surface roughening treatment using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current with a time TP of 0.8 ms until the current value reaches a peak from zero, a DUTY ratio of 1: 1. went. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type. The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Thereafter, washing with water was performed using well water.

(E) Alkaline etching treatment An aluminum plate was sprayed with an aqueous solution of caustic soda concentration of 26% by mass and aluminum ion concentration of 6.5% by mass at 32 ° C., and produced by (d) electrochemical roughening treatment in the previous stage. The smut component mainly composed of aluminum hydroxide was removed, and the edge portion of the generated pit was dissolved to smooth the edge portion. Thereafter, washing with water was performed using well water. The etching amount was 3.5 g / m ² .

(F) Desmut treatment Desmut treatment by spraying was performed with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (including 4.5% by weight of aluminum ions), and then washed with water using well water. As the nitric acid aqueous solution used for the desmut treatment, the waste liquid from the electrochemical surface roughening treatment step (d) was used.

(G) Electrochemical surface roughening treatment An electrochemical surface roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 7.5 g / liter aqueous solution (containing 5 g / liter of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform was a rectangular wave, and an electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type. The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. Thereafter, washing with water was performed using well water.

(H) Alkaline etching treatment An aluminum plate was sprayed with an aqueous solution of caustic soda concentration of 26% by mass and aluminum ion concentration of 6.5% by mass at 32 ° C. to dissolve the aluminum plate by 0.10 g / m ² , g) The smut component mainly composed of aluminum hydroxide generated by the electrochemical surface roughening treatment was removed, and the edge portion of the generated pit was dissolved to smooth the edge portion. Thereafter, washing with water was performed using well water.

(I) Desmut treatment A desmut treatment by spraying was performed with a 25% by mass aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by mass of aluminum ions), and then water washing by spraying was performed using well water.

(J) Anodizing treatment As the electrolytic solution, sulfuric acid was used. The electrolytic solution had a sulfuric acid concentration of 170 g / liter (containing 0.5% by mass of aluminum ions) and a temperature of 43 ° C. Thereafter, washing with water was performed using well water. The current density was about 30 A / dm2. The final oxide film amount was 2.7 g / m ² .

(K) Alkali metal silicate treatment The alkali metal silicate treatment (silicate treatment) was performed by immersing the aluminum plate in a treatment layer of a 1 mass% aqueous solution of sodium silicate No. 3 at a temperature of 30 ° C. for 10 seconds. . Then, the aluminum support body was produced by performing the water washing by the spray using well water. The amount of silicate deposited was 3.6 mg / m2.

(Formation of undercoat layer)
On the obtained support, a methanol solution of a copolymer (mass average molecular weight 35000) represented by the following polymer compound (1) is applied with a wire bar, and dried at 80 ° C. for 60 seconds to form an undercoat layer. did. The coating amount was 0.01 g / m2.

(Formation of photosensitive layer)
A photosensitive layer coating solution 6 having the following composition is bar-coated on the aluminum support having the above-mentioned undercoat layer and then oven-dried at 70 ° C. for 60 seconds to form a photosensitive layer having a dry coating amount of 1.0 g / m ^2. Thus, lithographic printing plate precursors (76) to (86) were prepared.

(Photosensitive layer coating solution 6)
・ Binder polymer listed in Table 7 0.50 g
・ Polymerizable compound 1.18 g
Isocyanuric acid EO-modified triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester M-315)
・ The following polymerization initiator (2) 0.20 g
・ The following infrared absorber (1) 0.05 g
・ The following fluorosurfactant (2) 0.05g
・ 1-Methoxy-2-propanol 18.00g

(1) Exposure and printing Each of the above lithographic printing plate precursors was exposed with a Trendsetter 3244VX manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser under the conditions of an output of 9 W, an outer drum rotational speed of 210 rpm, and a resolution of 2400 dpi. The obtained exposed lithographic printing plate precursor was mounted on a cylinder of a printing machine SOR-M manufactured by Heidelberg without developing. Dampening solution (EU-3 (Etch solution manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (Dainippon Ink and Chemicals, Inc.) Printing) was performed at a printing speed of 6000 sheets per hour.

(2) Evaluation <Developability>
The number of print sheets required until the on-press development on the printing press of the unexposed portion of the photosensitive layer was completed and no ink was transferred to the print paper was measured as on-press developability. The results were relative evaluated based on the following formula with Comparative Example 24 as a reference (1.0). The larger the numerical value of the relative developability, the higher the developability and the better the performance.
Relative developability = (Number of on-machine developments of the reference photosensitive material) / (Number of on-machine developments of the target photosensitive material)

<Sensitivity>
After 100 sheets were printed as described above and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were printed continuously. In the total 600th printed matter, the exposure amount with no unevenness in the ink density in the image area was measured as sensitivity. The sensitivity evaluation is expressed as a relative sensitivity defined as follows using the comparative example 24 as a reference (1.0). The larger the relative sensitivity value, the higher the sensitivity and the better the performance.
Relative sensitivity = (sensitivity of standard photosensitive material) / (sensitivity of target photosensitive material)

<Print durability>
As the number of printed sheets was increased, the photosensitive layer was gradually worn out and the ink acceptability was lowered, so that the ink density in the printing paper was lowered. In the printing plate exposed with the same exposure amount, the 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 evaluation of printing durability is represented by the relative printing durability defined as follows using Comparative Example 24 as a reference (1.0). The larger the relative printing durability number, the higher the printing durability.
Relative printing durability = (printing durability of target photosensitive material) / (printing durability of standard photosensitive material)

[Examples 61-68 and Comparative Examples 27-29]
<Preparation of lithographic printing plate precursors (87) to (97)>
On the aluminum support having the same undercoat layer as the lithographic printing plate precursor (76), a coating solution obtained by mixing and stirring the photosensitive layer coating solution 7 and the microcapsule solution 2 having the following composition just before coating is applied to the bar. Then, it was oven dried at 100 ° C. for 60 seconds to form a photosensitive layer having a dry coating amount of 1.1 g / m ² .

(Photosensitive layer coating solution 7)
-0.162 g of binder polymer described in Table 8
・ The above polymerization initiator (2) 0.160 g
・ The following polymerization initiator (3) 0.180 g
・ The following infrared absorber (2) 0.020 g
・ Polymerizable compound 0.385 g
Aronix M-215 (manufactured by Toa Gosei Co., Ltd.)
・ 0.044 g of the above fluorosurfactant (2)
・ Methyl ethyl ketone 1.091g
-1-methoxy-2-propanol 8.210 g

(Microcapsule solution 2)
-Microcapsule dispersion (2) synthesized as follows: 2.640 g
・ Water 2.425g

(Preparation of microcapsule dispersion (2))
As an oil phase component, trimethylolpropane and xylene diisocyanate adduct (manufactured by Mitsui Takeda Chemical Co., Ltd., Takenate D-110N, 75% by mass ethyl acetate solution) 10 g, Aronix SR-399 (manufactured by Toagosei Co., Ltd.) 6.00 g and 0.12 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 16.67 g of ethyl acetate. PVA-205 as an aqueous phase component
37.5 g of a 4% by weight aqueous solution of 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 2 hours. The microcapsule liquid thus obtained was diluted with distilled water so that the solid content concentration was 15% by mass to obtain a microcapsule dispersion (2). The average particle size of the microcapsules was 0.2 μm.

After the protective layer coating solution 3 having the following composition was applied onto the photosensitive layer with a bar, it was oven dried at 125 ° C. for 75 seconds to form a protective layer having a dry coating amount of 0.15 g / m ² to form a planographic printing plate precursor ( 87) ~
(97) was obtained.

(Protective layer coating solution 3)
・ Polyvinyl alcohol (6% by mass aqueous solution) 2.24 g
Kuraray PVA105, degree of saponification 98.5 mol%, degree of polymerization 500)
・ Polyvinylpyrrolidone (K30) 0.0053g
-1% by weight aqueous solution of surfactant (Emalex 710 manufactured by Kao Corporation) 2.15 g
Scale-like synthetic mica (3.4% by mass aqueous dispersion) 3.75 g
(MEB3L manufactured by UNICOO Co., Ltd., average particle diameter of 1 to 5 μmΦ)
・ Distilled water 10.60g

  The lithographic printing plate precursors (87) to (97) thus obtained were evaluated in the same manner as in Example 53. The results are shown in Table 8.

As is clear from the above results, the planographic printing plate precursor of the present invention has high developability, high image formation sensitivity, and high printing durability. This is considered to be an effect of the specific binder polymer according to the present invention. The specific binder polymers used in the above examples all have an acid value of 0.3 meq / g or less.

It is explanatory drawing which shows the structure of an automatic developing processor.

Explanation of symbols

61 Rotating brush roll 62 Receiving roll 63 Conveying roll 64 Conveying guide plate 65 Spray pipe 66 Pipe line 67 Filter 68 Feeding plate 69 Discharging plate 70 Developer tank 71 Circulating pump 72 Plate

Claims (8)

  On the support, a binder polymer having a functional group having a dipole moment of 3.8 Debye or more and an acid value of 0.3 meq / g or less, a radical polymerizable compound, and a radical polymerization initiator are contained. A lithographic printing plate precursor having a photosensitive layer. The functional group having a dipole moment of 3.8 Debye or more is a functional group represented by the following general formula (1), (2), (3), (4) or (5) The lithographic printing plate precursor as claimed in claim 1.

Wherein, X and Y are each _{-C (R 5) (R 6} ) -, - C (R 5) =, - O -, - S -, - N (R
₅ )-or -N =, Z ₁ represents O or S, Z ₂ represents O or a lone pair, Z ₃
-C is _{(R 5) (R 6)} -, - C (R 5) =, - O -, - S -, - N (R 5) - or an -N =. R _{1 to} R ₆ each independently represent a substituent consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon, or any two of them may be bonded to each other. To form a ring. However, at least one of R _{1 to} R ₆ is a divalent linking group linked to a binder polymer skeleton consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon. .   The lithographic printing plate precursor as claimed in claim 1 or 2, wherein the binder polymer contains more than 20 mol% of repeating units having a functional group having a dipole moment of 3.8 debye or more.   The lithographic printing plate precursor as claimed in any one of claims 1 to 3, wherein the photosensitive layer further contains a sensitizing dye having absorption at 300 to 1200 nm.   The lithographic printing plate precursor as claimed in any one of claims 1 to 4, further comprising a protective layer on the photosensitive layer.   The lithographic printing plate precursor as claimed in any one of claims 1 to 5, which can be developed with an aqueous solution having a pH of 10 or less.   6. The lithographic printing plate precursor as claimed in claim 1, wherein the lithographic printing plate precursor can be mounted on a printing press and printed without any processing after image exposure.   The lithographic printing plate precursor according to claim 7 is mounted on a printing press and imagewise exposed with a laser or imagewise exposed with a laser and then mounted on a printing press and exposed. A lithographic printing method, wherein printing ink and fountain solution are supplied to an original plate to remove an unexposed portion of the photosensitive layer and print.

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