JP2002107916A - Original plate for planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for planographic printing plate capable of direct recording from digital data with an IR laser, not requiring heating after imagewise exposure, having high sensitivity, less liable to stain due to the progress of an undesirable curing reaction of a non-image area and capable of forming an image of high image quality. SOLUTION: The original plate has a photosensitive layer capable of recording with an IR laser and containing (A) a polymerization initiator selected from borate compounds and triazine compounds, (B) a polymerization inhibitor, (C) a photothermal converting agent and (D) a compound having a polymerizable unsaturated group on the substrate. The component (B) is, e.g. a phenolic compound, quinone or an N-oxide compound and preferable to which 0.01-10 mol% of the amount of the component (A) is added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor that can be written with an infrared laser, and more particularly to a lithographic printing plate precursor having a negative recording layer with excellent printing durability.

[0002]

2. Description of the Related Art In recent years, the development of lasers has been remarkable. In particular, solid-state lasers and semiconductor lasers having a light-emitting region from the near infrared to the infrared have been increasing in output and miniaturization. Therefore, these lasers are very useful as an exposure light source when making a plate directly from digital data of a computer or the like. Using an infrared laser having an emission region in the infrared region as an exposure light source, a negative type lithographic printing plate material for an infrared laser, an infrared absorber, and a polymerization initiator that generates radicals by light or heat,
A planographic printing plate material having a photosensitive layer containing a polymerizable compound.

As such a negative type image recording material, for example, a recording material comprising an infrared absorber, an acid generator, a resol resin and a novolak resin is disclosed in US Pat.
No. 699. However, such a negative type image recording material requires a heat treatment of heating at 140 to 200 ° C. for about 50 to 120 seconds after laser exposure in order to form an image. It required extensive equipment and energy.

Japanese Patent Publication No. 7-103171 discloses a heat treatment after imagewise exposure comprising a cyanine dye having a specific structure, an iodonium salt and an addition-polymerizable compound having an ethylenically unsaturated double bond. Although a recording material that is not required is described, this image recording material has a problem that polymerization is inhibited by oxygen in the air during a polymerization reaction, resulting in a decrease in sensitivity and an insufficient strength of a formed image portion. was there. On the other hand, in order to improve sensitivity, a method of using a borate compound having a high donor property and itself having a photopolymerization initiating ability as an initiator is also conceivable, but in this case, the case of handling under a white light or a low extinction ratio is considered. When a plate setter is used, or when stored for a long period of time, an undesired curing reaction proceeds, and there is a concern that image forming properties may be degraded, for example, stains may easily occur on non-image areas.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to record directly using digital data from a computer or the like by recording using a solid-state laser and a semiconductor laser that emit infrared light. It is an object of the present invention to provide a lithographic printing plate precursor capable of forming a high-quality image, which does not require a heat treatment, has high sensitivity, and suppresses generation of stains due to an undesired progress of a curing reaction in a non-image portion.

[0006]

Means for Solving the Problems The present inventor paid attention to the constituent components of a negative type image recording material, and as a result of intensive studies, as a result of using a photon mode highly sensitive initiator and a polymerization inhibitor together, The inventors have found that it is possible to achieve both high sensitivity and suppression of an undesired curing reaction of the recording layer, and have completed the present invention. That is, the lithographic printing plate precursor according to the invention is provided on a support,
(A) a polymerization initiator selected from a borate compound and a triazine compound, (B) a polymerization inhibitor, (C) a photothermal conversion agent, and (D) a compound having a polymerizable unsaturated group, A negative type photosensitive layer recordable with an infrared laser is provided. The photosensitive layer preferably further contains (E) a binder for the purpose of improving the film properties.

It is considered that a borate compound or triazine compound used as a highly sensitive polymerization initiator in the present invention forms an image in a mixed system of photon mode and heat mode by exposure to infrared laser. Photon mode type image formation is performed with high sensitivity. For example, a small amount of laser light applied to the non-image area during laser exposure, or exposure to weak energy such as the influence of light due to handling under a white light Generates a small amount of radicals, which causes an undesired unexposed portion to undergo a curing reaction. On the other hand, in heat mode image formation,
An image is not formed unless the exposure amount exceeds a certain value. In the present invention, a borate compound or a triazine compound that forms an image in a mixed system of a photon mode and a heat mode is used as a polymerization initiator. In this case, a large amount of radicals are generated thermally (heat mode) at a certain exposure amount or more, and a large amount of radicals are generated even in the photon mode under the exposure conditions. For this reason, photon mode, by using a specific compound and a small amount of polymerization inhibitor to form an image in a mixed system of the heat mode, polymerization in the photon mode that occurs when the predetermined exposure amount is not reached can be suppressed. When the exposure amount exceeds a predetermined value, even if a small amount of the polymerization inhibitor is present, it is possible to form an image in the image area without being largely affected by the polymerization inhibitor. That is, it is possible to suppress only the image formation of the photon mode system without impairing the image formation reaction by the heat mode system, and to suppress the fog of the non-image portion without lowering the sensitivity.

In the present invention, "corresponding to the heat mode" means that recording by heat mode exposure is possible. The definition of the heat mode exposure in the present invention will be described in detail. Hans-Joachim Tim
pe, IS & Ts NIP 15: 1999 Inte
rational Conference on D
digital printing technology
ies. P. As described in 209, a photoabsorbing substance (for example, a dye) is photoexcited in a photoreceptor material, and undergoes a chemical or physical change to form a chemical or physical change from the photoexcitation of the photoabsorbing substance forming an image. It is known that there are roughly two modes in the above processes. One is that the photo-excited light-absorbing substance deactivates due to some photochemical interaction (eg, energy transfer, electron transfer) with other reactants in the photosensitive material,
As a result, a so-called photon mode in which the activated reactant causes a chemical or physical change required for the above-described image formation, and the other is that the photoexcited light absorbing substance generates heat and deactivates, and the heat is lost. This is a so-called heat mode in which a reactant causes a chemical or physical change required for image formation by utilizing the above-mentioned method. In addition, there are special modes such as ablation in which substances are explosively scattered by the energy of light locally collected and multiphoton absorption in which one molecule absorbs many photons at a time, but these modes are omitted here.

[0009] The exposure processes utilizing the above modes are called photon mode exposure and heat mode exposure. The technical difference between photon mode exposure and heat mode exposure is whether or not the energy amount of several photons to be exposed can be added to the energy amount of the target reaction.
For example, consider a case where a certain reaction occurs using n photons. In photon mode exposure, photochemical interaction is used, so that the energy of one photon cannot be added and used due to the requirement of the law of conservation of quantum energy and momentum. That is, in order to cause a certain reaction, the relationship of “energy amount of one photon ≧ energy amount of reaction” is necessary. On the other hand, in heat mode exposure, heat is generated after light excitation, and light energy is converted into heat and used, so that the amount of energy can be added. Therefore, the relationship “energy amount of n photons ≧ energy amount of reaction” is sufficient. However, this energy addition is restricted by thermal diffusion. In other words, if the next photoexcitation-deactivation process occurs and heat is generated before heat escapes from the exposed portion (reaction point) of interest by thermal diffusion, the heat is reliably accumulated and added, and the temperature rises in that portion. Leads to. However, when the next heat is generated slowly, the heat escapes and is not accumulated. In other words, in the heat mode exposure, even if the total exposure energy is the same, the result is different between the case where the high energy light is irradiated for a short time and the case where the low energy light is irradiated for a long time. It becomes advantageous for accumulation of.

Of course, in the photon mode exposure, a similar phenomenon may occur due to the influence of the diffusion of the subsequent reactive species, but basically, such a phenomenon does not occur. That is, in terms of the characteristics of the photosensitive material, in the photon mode, the intrinsic sensitivity of the photosensitive material (the energy required for the reaction required for image formation) is compared with the exposure power density (w / cm ² ) (= energy density per unit time) Amount) is constant, but in the heat mode, the intrinsic sensitivity of the photosensitive material increases with respect to the exposure power density. Therefore, when the exposure time is fixed so that the productivity required for practical use as an image recording material can be maintained, the photon mode exposure usually has a high sensitivity of about 0.1 mJ / cm ² when comparing the modes. Reaction can be achieved at any low exposure, although
The problem of low-exposure fog in unexposed areas is likely to occur. On the other hand, in the heat mode exposure, a reaction does not occur unless the exposure amount exceeds a certain value, and about 50 mJ / cm ² is usually required in view of the thermal stability of the photosensitive material. Is avoided. In fact, in heat mode exposure, the exposure power density on the plate surface of the photosensitive material is 500
0 w / cm ² or more, preferably 10,000
w / cm ² or more is required. However, although not described in detail here, when a high power density laser of 5.0 × 10 ⁵ / cm ² or more is used, ablation occurs, which is not preferable because of problems such as soiling the light source.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [(A) Polymerization initiator selected from borate-based compound and triazine-based compound (hereinafter, appropriately referred to as a specific polymerization initiator)] A borate-based compound suitable as the specific polymerization initiator of the present invention is represented by the following general formula: The compound represented by (I) is mentioned.

[0012]

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In the formula, R ¹ , R ² , R ³ and R ⁴ each independently represent an organic group. However, at least one of R ¹ , R ² , R ³ and R ⁴ is an alkyl group. Z ^{n +} is n
Represents a cation having a valence, and n represents an integer of 1 to 6.

Hereinafter, the general formula (I) will be described in detail. Examples of R ¹ , R ² , R ³ and R ⁴ include an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkenyl group, a substituted alkenyl group, an alkynyl group and a substituted alkynyl group, and a heterocyclic group. . However,
At least one of R ¹ , R ² , R ³ and R ⁴ is a substituted or unsubstituted alkyl group.

The alkyl group has 1 to 2 carbon atoms.
0, straight-chain, branched or cyclic alkyl groups, specific examples of which include methyl, ethyl, propyl, butyl, pentyl, hexyl,
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,
Examples thereof include a cyclohexyl group, a cyclopentyl group, and a 2-norbornyl group. Among them, 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.

The substituted alkyl group is constituted by a bond between a substituent and an alkylene group. As the substituent, a monovalent nonmetallic atomic group other than hydrogen is used, and a preferable example is a halogen atom (-F,- Br, -Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino Group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-
Arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-ary Rucarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N ′
An alkylureido group, an N ′, N′-dialkylureido group, an N′-arylureido group, an N ′, N′-diarylureido group, an N′-alkyl-N′-arylureido group, an N-alkylureido group; N-arylureido group, N'-alkyl-N-alkylureido group, N '
-Alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N
-Alkylureido group, N'-aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N'-alkyl-N '-Aryl-N-alkylureido groups, N'-alkyl-N'-aryl-N-
Arylureido group, alkoxycarbonylamino group,
Aryloxycarbonylamino group, N-alkyl-N-
Alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group,
Carboxyl group and its conjugate base group (hereinafter, referred to as carboxylate), alkoxycarbonyl group,

Aryloxycarbonyl, carbamoyl, N-alkylcarbamoyl, N, N-dialkylcarbamoyl, N-arylcarbamoyl, N, N
A diarylcarbamoyl group, an N-alkyl-N-arylcarbamoyl group, an alkylsulfinyl 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 and ), Alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group , N-alkyl-N-arylsulfinamoyl, sulfamoyl, N-alkylsulfamoyl, N, N-dialkylsulfamoyl, N-arylsulfamoyl, N, N-diarylsulfamoyl Group, N-alkyl-N-aryls Famoiru group, N- acylsulfamoyl group and a conjugate base group, N- alkylsulfonylsulfamoyl group _{(-SO 2 NHSO 2 (alkyl)} ) and its conjugated base group, N- aryl sulfonylsulfamoyl group (- SO ₂ NHSO ₂ (allyl)) and its conjugate base group, N-alkylsulfonylcarbamoyl group (—CO
NHSO ₂ (alkyl) and its conjugate base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (ally
l)) and its conjugate base group, alkoxysilyl group (—S
i (O alkyl) ₃ ), an aryloxysilyl group (-Si
(O allyl) ₃ ), a hydroxysilyl group (—Si (O
H) ₃ ) and its conjugate base group, phosphono group (—PO
₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonate group), dialkylphosphono group (—PO ₃ (alkyl) ₂ ),
Diarylphosphono group (-PO3 (aryl) 2), alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )), monoalkyl phosphono group (-PO ₃ H (alkyl)) and its conjugated base group ( hereinafter referred to as alkylphosphonato group), monoarylphosphono group (-PO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as aryl phosphite Hona preparative group), phosphonooxy group (-OPO ₃ H ₂₎ and a conjugated base group thereof (hereinafter referred to as phosphonatooxy group), dialkylphosphono group (-OPO ₃ (alkyl) _2), diaryl phosphono group (-OPO ₃ (aryl) _2), alkylaryl phosphono group ( -OPO ₃ (alkyl) (ary
l)), a monoalkylphosphonooxy group (—OPO ₃ H
(Alkyl)) and its conjugated base group (hereinafter referred to as alkylphosphonato group), monoarylphosphono group (-OPO ₃ H (aryl)) and its conjugated base group (hereinafter, the aryl phosphite Hona preparative group ), A cyano group,
Examples include a nitro group, an aryl group, an alkenyl group, and an alkynyl group.

In these substituents, specific examples of the alkyl group include the aforementioned alkyl groups, and specific examples of the aryl group include phenyl, biphenyl, naphthyl, tolyl, xylyl, mesityl and the like. , Cumenyl group, fluorophenyl 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, ethoxycarbonylphenyl group, phenoxycarbonylphenyl group, N-phenylca Ba carbamoylphenyl group, a phenyl group, nitrophenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group,
Examples include a phosphonatophenyl group. Examples of the alkenyl group include vinyl, 1-propenyl, 1-butenyl, cinnamyl, 2-chloro-
Examples thereof include a 1-ethenyl group, and examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 1-butynyl group,
Examples include a trimethylsilylethynyl group and a phenylethynyl group.

As the above-mentioned acyl group (R ⁴ CO—),
R ^{4 includes a} hydrogen atom and the above-mentioned alkyl, aryl, alkenyl and alkynyl groups.

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

Specific examples of preferred substituted alkyl groups include chloromethyl, bromomethyl, 2-chloroethyl, trifluoromethyl, methoxymethyl, methoxyethoxyethyl, allyloxymethyl, phenoxymethyl, 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, methoxy Carbonylethyl group, methoxycarbonylmethyl group, methoxycarbonylbutyl group, ethoxycarbonylmethyl group,
Butoxycarbonylmethyl group,

Allyloxycarbonylmethyl, benzyloxycarbonylmethyl, methoxycarbonylphenylmethyl, trichloromethylcarbonylmethyl,
Allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- ( Sulfophenyl) carbamoylmethyl group, sulfopropyl 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 , Le phosphono hexyl group, tolyl phosphate Hona preparative hexyl, phosphono propyl group, phosphate Hona preparative oxy butyl group, benzyl group, phenethyl group, alpha-
Methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group,
Examples thereof include a 1-propenylmethyl group, a 2-butenyl group, a 2-methylallyl group, a 2-methylpropenylmethyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, and the following groups.

[0023]

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Examples of the aryl group include a group in which one to three benzene rings form a condensed ring, and a group in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Group, naphthyl group, anthryl group, phenanthryl group, indenyl group, acenabutenyl group,
Examples thereof include a fluorenyl group and the like, and among these, a phenyl group and a naphthyl group are more preferable.

The substituted aryl group is a group in which a substituent is bonded to an aryl group, and those having a monovalent nonmetallic atomic group other than hydrogen as a substituent on a ring-forming carbon atom of the aforementioned aryl group are used. Can be Preferred examples of the substituent include the aforementioned alkyl group, substituted alkyl group, and those described above as the substituent for the substituted alkyl group.

Preferred specific examples of these substituted aryl groups are biphenyl, tolyl, xylyl, mesityl, cumenyl, chlorophenyl, bromophenyl, fluorophenyl, chloromethylphenyl,
Trifluoromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group,
Methylthiophenyl group, tolylthiophenyl group, phenylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, acetyloxyphenyl group, benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxy Phenyl group, acetylaminophenyl group, N-methylbenzoylaminophenyl group, carboxyphenyl 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, sulfa Moylphenyl group, N-ethylsulfamoylphenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, Phosphonophenyl, phosphonatophenyl, diethylphosphonophenyl, diphenylphosphonophenyl, methylphosphonophenyl, methylphosphonatophenyl, tolylphosphonophenyl, tolylphosphonatophenyl, allyl, 1 -Propenylmethyl group, 2 Butenyl, 2-methyl-allyl phenyl group, 2-methyl propenyl phenyl group, 2-propynyl phenyl group, 2-butynyl phenyl group, and a 3-butynylphenyl group.

Examples of the alkenyl group include the same alkenyl groups as those described above for the substituent that can be introduced. A substituted alkenyl group is a substituent in which a substituent replaces and bonds to a hydrogen atom of an alkenyl group.As the substituent, the substituent in the above-mentioned substituted alkyl group is used, while the alkenyl group uses the above-mentioned alkenyl group be able to. Preferred examples of the substituted alkenyl group include those represented by the following structures.

[0028]

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Examples of the alkynyl group include the same alkynyl groups as those described above for the substituent that can be introduced. A substituted alkynyl group is a substituent in which a hydrogen atom of an alkynyl group is replaced and bonded,
As the substituent, the substituent in the above-mentioned substituted alkyl group is used, while the alkynyl group can be the above-mentioned alkynyl group.

A heterocyclic group is a monovalent group obtained by removing one hydrogen on a heterocyclic ring and one hydrogen is further removed from the monovalent group, and the substituent in the above-mentioned substituted alkyl group is bonded. The resulting monovalent group (substituted heterocyclic group). Preferred examples of the hetero ring include those represented by the following structures.

[0031]

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[0032]

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[0033]

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Next, R¹And R^Two, R^TwoAnd R^ThreeAre connected to each other
An example in which a ring is formed by the following method is shown. R ¹And R^Two, R^TwoAnd R^ThreeBut
As the aliphatic ring formed by bonding to each other, a 5-membered ring, 6
And 7-membered and 8-membered aliphatic rings.
And more preferably a 5- or 6-membered aliphatic ring.
Can be These are furthermore the charcoal that makes them up
May have a substituent on the elemental atom,
The substituent on the above-mentioned substituted alkyl group may be mentioned
it can. In addition, part of the ring-constituting carbon is a hetero atom (eg,
For example, oxygen, sulfur, nitrogen, etc.)
May be. Further, a part of the aliphatic ring is an aromatic ring.
May be partially formed.

Examples of the n-valent cation Z ^{n +} include alkali metal ion, quaternary ammonium, pyridinium, quinolinium, diazonium, monophorinium, tetrazolium, acridinium, phosphonium,
Sulfonium, oxosulfonium, sulfur, oxygen, carbon halogenium, Cu, Ag, Hg, Pd, Fe, Co,
Sn, Mo, Cr, Ni, As, Se and the like.
More preferred is quaternary ammonium.

Preferred specific examples of the compound represented by formula (I) [(I-1) to (I-101)] are shown below, but the present invention is not limited thereto. In addition,
In the following compounds, the exemplary compound represented by (I-38) is
Compound (I-34), tetramethylammonium methyl-
Tris (trimethylsilylmethyl) -porate and tetramethylammonium dimethylbis (trimethylsilylmethyl) porate and tetramethylammoniumdimethylbis (trimethylsilylmethyl) porate:
It is a 10: 1 mixture.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

[Table 6]

[0043]

[Table 7]

Of the above borate compounds, compounds containing at least one phenyl group substituted by fluorine at the m-position are more preferred.

The triazine compound suitable as the specific polymerization initiator of the present invention is a compound represented by the general formula (II).

[0046]

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In the formula (II), X ² represents a halogen atom.
Y ² is -CX ² , -NH ₂ , -NHR ³² -NR ³² or-
Representing the OR ^32. Here, R ³² represents an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group. R ³¹ is-
CX ^{2 represents} an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group or a substituted alkenyl group.

Specific examples of triazine compounds represented by the general formula (II) include, for example, Wakabayashi et al., Bull.
em. Soc. Japan, 42, 2924 (1969), for example, 2-phenyl 4,6-bis (trichloromethyl) -S-triazine, 2- (p-chlorophenyl) -4,6-bis ( Trichloromethyl) -S-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S -Triazine, 2- (2 ', 4'-dichlorophenyl) -4,6
-Bis (trichloromethyl) -S-triazine, 2,
4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-bis (trichloromethyl)-
S-triazine, 2-n-nonyl-4,6-bis (trichloromethyl) -S-triazine, 2- (α, α, β-
Trichloroethyl) -4,6-bis (trichloromethyl) -S-triazine and the like.

Other compounds described in British Patent 1,388,492, for example, 2-styryl-4,6-
Bis (trichloromethyl) -S-triazine, 2- (p
-Methylstyryl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl)
-4,6-bis (trichloromethyl) -S-triazine, 2- (p-methoxystyryl) -4-amino-6
JP-A-53-1 such as trichloromethyl-S-triazine
No. 33428, for example, 2- (4-methoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy-naphth-1-yl) -4 , 6-Bis-trichloromethyl-S-
Triazine, 2- [4- (2-ethoxyethyl) -naphth-1-yl] -4,6-bis-trichloromethyl-S
-Triazine, 2- (4,7-dimethoxy-naphtho-1
-Yl) -4,6-bis-trichloromethyl-S-triazine), 2- (acenaphth-5-yl) -4,6-bis-trichloromethyl-S-triazine and the like, German Patent 3,337,024. Compounds described in the above specification, for example,
The following exemplified compounds (T-1) to (T-8) can be exemplified.

[0050]

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[0051]

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Also, J. Org. Ch. By FC Schaefer et al.
em. 29, 1527 (1964), for example, 2-methyl-4,6-bis (tribromomethyl) -S
-Triazine, 2,4,6-tris (tribromomethyl) -S-triazine, 2,4,6-tris (dibromomethyl) -S-triazine, 2-amino-4-methyl-
6-Tribromomethyl-S-triazine, 2-methoxy-4-methyl-6-trichloromethyl-S-triazine and the like can be mentioned. Further, JP-A-65-2824
Compounds described in No. 1, for example, Exemplified Compound (T-9) to
(T-14) and the like.

[0053]

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Further, compounds described in JP-A-5-281728, for example, exemplified compounds (T-15) to (T-2)
2) and the like.

[0055]

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[(B) Polymerization Inhibitor] In the present invention, the polymerization inhibitor means that the compound reacts with a radical to stabilize the generated radical and prevent the polymerization from being carried out, or the radical polymerization is carried out. It refers to a compound that has the function of greatly suppressing the reaction rate and making the reaction extremely slow. Examples of the polymerization inhibitor that can be used in the present invention include known phenolic compounds, quinones, N-oxide compounds, amine compounds, sulfide group-containing compounds, nitro group-containing compounds, and F-type compounds.
Examples include transition metal compounds such as eCl ₃ and CuCl ₂ .

Preferred polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl and p-
Cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t
-Butylphenol), 2,2'-methylenebis (4-
Methyl-6-t-butylphenol), cerium N-nitrosophenylhydroxyamine, and the like. Other examples of the polymerization-inhibited compound include the following. Transition metal and typical metal compounds having the above-described compounds as ligands can also be suitably used. Examples of suitable polymerization inhibitors that can be used in the present invention are shown below, but the present invention is not limited thereto. Examples of the phenolic polymerization inhibitor include the following exemplified compounds (P-1) to (P-24).

[0058]

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[0059]

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[0060]

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[0061]

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Examples of the amine polymerization inhibitor include the following exemplified compounds (N-1) to (N-7).

[0063]

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Examples of the sulfur polymerization inhibitor include the following exemplified compounds (S-1) to (S-5).

[0065]

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Examples of the phosphite polymerization inhibitor include the following exemplified compounds (R-1) to (R-5).

[0067]

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Further, the following compounds can also be used as suitable polymerization inhibitors.

[0069]

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The preferable addition amount of the polymerization inhibitor is 0.01% with respect to the molar amount of the specific polymerization initiator (A).
-10%, preferably 0.01% -8%
%, And most preferably in the range of 0.05% to 5%. When the addition amount is less than 0.01%, the curing reaction inhibition curing in the non-image area is not sufficiently obtained, and when the addition amount is more than 10%, the curing reaction of the photosensitive layer is suppressed even in the image area, resulting in image formation. The properties and sensitivity tend to decrease, which is not preferred.

[(C) Photothermal Conversion Agent] In the present invention, the photothermal conversion agent contained in the photosensitive layer is not particularly limited as long as it has a photothermal conversion function of generating heat by irradiation with an infrared laser. So-called infrared absorbers can be used. The photothermal conversion agent used in the present invention is
An infrared absorbing dye or pigment having an absorption maximum at a wavelength of 760 nm to 1200 nm is preferable.

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

Preferred dyes include, for example, those described in
Cyanine dyes described in JP-A-8-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787 and the like, and JP-A-58-1736.
No. 96, JP-A-58-181690, JP-A-58-1
No. 94595, etc., methine dyes described in
8-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996,
Naphthoquinone dyes described in JP-A-60-52940 and JP-A-60-63744;
Squarylium dyes described in No. 12792, etc.,
Cyanine dyes described in British Patent 434,875 and the like can be mentioned.

Further, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also preferable. Pyrylium salt, JP-A-57-142645
No. (U.S. Pat. No. 4,327,169), trimethinethiapyrylium salts described in JP-A-58-181051, 58-220143, 59-41363, and 59.
Nos. -84248, 59-84249, 59-14
Nos. 6063 and 59-146061, pyranyl compounds, cyanine dyes described in JP-A-59-216146, pentamethine thiopyrylium salts described in U.S. Pat. No. 4,283,475, and the like. Fairness 5-13
Pyrylium compounds disclosed in JP-A-514 and JP-A-5-19702 are also preferably used.

Further, as another preferred example of the dye, US Pat. No. 4,756,993 discloses a compound represented by the formula (I):
Near-infrared absorbing dyes described as (II) can be mentioned.

Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Further, a cyanine dye is preferable, and a cyanine dye represented by the following general formula (I) is most preferable.

[0077]

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In the general formula (I), X ¹ is a halogen atom,
Or an X ² -L ^1. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of storage stability of a photosensitive layer coating liquid, R ¹ and R ² are preferably a hydrocarbon group having two or more carbon atoms, further, R ¹ and R ²
And particularly preferably combine with each other to form a 5- or 6-membered ring.

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. Preferred examples of the substituent include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, and an alkoxy group having 12 or less carbon atoms. 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 represent 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,
Examples include a carboxyl group and a sulfo group. R ⁵ , R ⁶ , R
⁷ and R ⁸ may be the same or different,
It represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the viewpoint of availability of raw materials, a hydrogen atom is preferable. Z ^1- represents a counter anion. However, when any of R ^{1 to} R ⁸ is substituted with a sulfo group, Z ¹⁻ is not necessary. Preferred Z ¹⁻ is, from the storage stability of the photosensitive layer coating solution, a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion,
And sulfonate ions, particularly preferably perchlorate ion, hexafluorophosphate ion and arylsulfonate ion.

In the present invention, specific examples of the cyanine dye represented by the general formula (I) which can be suitably used include paragraph [0] of Japanese Patent Application No. 11-310623.
017] to [0019].

As the pigment used as a photothermal conversion agent in the present invention, commercially available pigments and Color Index (CI) Handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, published in 1977), “Latest Pigment Application Technology ”(CMC
Publishing, 1986) and "Printing Ink Technology", CMC Publishing, 1984).

The pigments include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment,
Blue pigment, green pigment, fluorescent pigment, metal powder pigment, etc.
Polymer-bound dyes. Specifically, insoluble azo pigments, azo lake pigments, condensation azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments,
Perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dyed lake pigments,
Azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like can be used.
Preferred among these pigments is carbon black.

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

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

As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner 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. For details, refer to “Latest Pigment Application Technology” (CMC Publishing, 1
986).

These light-to-heat converting agents may be added to the same layer as other components, or may be added to a separate layer provided. However, when a negative type image forming material is prepared, It is preferable that the optical density of the photosensitive layer at the absorption maximum in the wavelength range of 760 nm to 1200 nm is between 0.1 and 3.0. Outside of this range, sensitivity tends to decrease. Since the optical density is determined by the amount of the infrared absorbing agent added and the thickness of the recording layer, a predetermined optical density can be obtained by controlling both conditions. The optical density of the recording layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a coating layer after drying is formed to a recording layer having a thickness appropriately determined in a range necessary for a lithographic printing plate, and a transmission type optical densitometer is used. Examples include a method of measuring, a method of forming a recording layer on a reflective support such as aluminum, and measuring a reflection density.

[(D) Compound having a polymerizable unsaturated group] The compound having a polymerizable unsaturated group used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond. And is preferably selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated bonds. Such compounds are widely known in the industrial field, and they can be used in the present invention without any particular limitation. These are, for example, monomers, prepolymers, ie dimers,
Includes those having chemical forms such as trimers and oligomers, or mixtures thereof, and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters and amides thereof, and are preferred. As the ester, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. Further, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group, an addition reaction product of an amide with a monofunctional or polyfunctional isocyanate, an epoxy,
A dehydration condensation product with a monofunctional or polyfunctional carboxylic acid is also preferably used.

Further, unsaturated carboxylic esters, amides and monofunctional or polyfunctional alcohols having an electrophilic substituent such as an isocyanato group and an epoxy group,
Amines, addition products with thiols, halogen groups,
Substitution products of unsaturated carboxylic acid esters and amides having a leaving substituent such as a tosyloxy group and the like with monofunctional or polyfunctional alcohols, amines and thiols are also suitable. As another example, it is also possible to use a group of compounds in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene, vinyl ether or the like.

Specific examples of the ester monomer of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3.
-Butanediol diacrylate, 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, SO Bito one Le pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloxy-2-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
There are 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.

The crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like. Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, and JP-A-57-196231, and JP-A-59-5240 and JP-A-59-5240. 59-524
1, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Further, the above-mentioned ester monomers can be used as a mixture.

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

A urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group is also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups per molecule and a hydroxyl-containing vinyl monomer represented by the following general formula (2) added to one molecule. Examples include vinyl urethane compounds containing two or more polymerizable vinyl groups.

[0097]

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In the general formula (2), R and R ′ represent H or CH ₃ . Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and
Urethane compounds having an ethylene oxide skeleton described in JP-A-8-49860, JP-B-56-17654, JP-B-62-39417, and JP-B-62-39418 are also suitable.

Further, by using 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. Can obtain a photosensitive composition having an extremely high photosensitive speed.

As another example, see JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
No. 490, polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in each publication. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Further, the Journal of the Adhesion Society of Japan, vol. 20, no. 7, pages 300 to 308 (1
984) as photocurable monomers and oligomers.

Regarding these addition-polymerizable compounds, what kind of structure is used, whether they are used alone or in combination,
Details of the method of use, such as the amount of addition, can be arbitrarily set in accordance with the final performance design of the light-sensitive material. For example, it is selected from the following viewpoints. From the viewpoint of the photosensitive speed, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or more functional structure is preferable. In order to increase the strength of the image area, that is, the cured film, those having three or more functional groups are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylates, methacrylates, styrene compounds, vinyl ethers) It is also effective to adjust both the photosensitivity and the intensity by using the compound (1) in combination. A compound having a large molecular weight or a compound having a high hydrophobicity is excellent in photosensitive speed and film strength, but may not be preferable in terms of developing speed and precipitation in a developing solution.

Further, compatibility with other components (eg, binder polymer, initiator, colorant, etc.) in the photosensitive composition,
The selection and use of the addition polymerization compound is also an important factor for the dispersibility. For example, the use of a low-purity compound or the combination of two or more compounds may improve the compatibility. When a lithographic printing plate precursor is used, a specific structure may be selected for the purpose of improving the adhesion of a support, an overcoat layer, and the like described below. Regarding the compounding ratio of the addition polymerizable compound in the photosensitive composition, the larger the proportion, the more advantageous in sensitivity. However, if the proportion is too large, undesired phase separation may occur or the production of the photosensitive composition due to the stickiness may occur. Process problems (for example, improper production due to transfer of photosensitive material components or adhesion)
In the case of a lithographic printing plate precursor, problems such as precipitation from a developer may occur. From these viewpoints, a preferable compounding ratio is often 5 to 80 with respect to all components of the composition.
% By weight, preferably 25 to 75% by weight. These may be used alone or in combination of two or more. In addition, the method of using the addition polymerizable compound can be arbitrarily selected from the viewpoints of the degree of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface tackiness, etc. Depending on the case, a layer structure and a coating method such as undercoating and overcoating may be performed.

[(E) Binder] In the lithographic printing plate precursor according to the invention, it is preferable to further use a binder polymer in the photosensitive layer. As the binder used here, a water-insoluble and aqueous alkaline solution-soluble linear organic high molecular polymer is preferable. As such a "linear organic high molecular polymer", any known polymer can be selected and used, but water or a weak alkali which enables water development or weak alkaline water development is preferable. A water-soluble or swellable linear organic high molecular polymer is selected. The linear organic high molecular polymer is selected and used not only as a film forming agent of the composition but also as a water, weakly alkaline water or organic solvent developing agent. For example, when a water-soluble organic high molecular polymer is used, water development becomes possible. Examples of such a linear organic high molecular polymer include an addition polymer having a carboxylic acid group in a side chain, for example, Japanese Patent Application Laid-Open No.
44615, JP-B-54-34327, JP-B-58
-12577, JP-B-54-25957, JP-A-5
4-92723, JP-A-59-53836, JP-A-59-71048, that is,
Examples include methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, and partially esterified maleic acid copolymer. Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful.

In particular, among these, [benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer and [allyl (meth) acrylate / (meth) acrylic acid / Other addition-polymerizable vinyl monomers as needed) copolymer,
It is suitable because it has an excellent balance of film strength, sensitivity and developability.

Further, Japanese Patent Publication No. 7-12004, Japanese Patent Publication
JP-A-120041, JP-B-7-120042, JP-B-8-12424, JP-A-63-287944, JP-A-63-287947, JP-A-1-271174,
The urethane-based binder polymer containing an acid group described in Japanese Patent Application No. 10-116232 is very excellent in strength, and is advantageous in terms of printing durability and low exposure suitability.
Further, a binder having an amide group described in JP-A-11-171907 is suitable because it has excellent developability and film strength.

Further, as the water-soluble linear organic polymer, polyvinyl pyrrolidone, polyethylene oxide and the like are useful. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These linear organic high molecular polymers can be incorporated in any amount into the entire composition. However, if it exceeds 90% by weight, no favorable result is obtained in view of the strength of the formed image and the like. Preferably 30 to 85
% By weight. The weight ratio of the photopolymerizable compound having an ethylenically unsaturated double bond and the linear organic high molecular weight polymer is preferably in the range of 1/9 to 7/3.

The binder polymer of the present invention is substantially insoluble in water and soluble in an aqueous alkali solution. For this reason, an organic solvent which is not environmentally unfavorable is not used or the amount used is extremely small as a developer.
The acid value (acid content per gram of polymer expressed by chemical equivalent number) and molecular weight of such a binder polymer are appropriately selected from the viewpoint of image strength and developability. The preferred acid value is 0.4 to 3.0 meq / g, and the preferred molecular weight is in the range of 3,000 to 500,000, more preferably the acid value is in the range of 0.6 to 2.0, and the molecular weight is in the range of 10,000 to 300,000. It is.

[(F) Other Components] To the photosensitive composition of the present invention, other components suitable for its use, production method and the like can be appropriately added. Hereinafter, preferred additives will be exemplified. (F-1) Co-sensitizer The sensitivity can be further improved by using a certain additive (hereinafter referred to as a co-sensitizer). Although their mechanism of action is not clear, most are thought to be based on the following chemical processes. That is, a co-sensitizer reacts with a photoreaction initiated by a thermal polymerization initiator and various intermediate active species (radicals, cations) generated during the subsequent addition polymerization reaction to generate a new active radical. It is estimated that These are largely (a) those that can be reduced to form active radicals, (b) those that can be oxidized to form active radicals, and (c) those that react with less active radicals and are more active radicals. Or acting as a chain transfer agent, but there is often no myth as to which of these compounds each belongs to.

(A) Compound that generates an active radical upon being reduced Compound having a carbon-halogen bond: It is considered that the carbon-halogen bond is reductively cleaved to generate an active radical. Specifically, for example, trihalomethyl-s-triazines, trihalomethyloxadiazoles and the like can be suitably used. Compound having a 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 an oxygen-oxygen bond: It is considered that an oxygen-oxygen bond is reductively cleaved to generate an active radical. Specifically, for example, organic peroxides and the like are preferably used. Onium compound: It is considered that a carbon-hetero bond or an oxygen-nitrogen bond is cleaved reductively to generate an active radical. Specifically, for example, diaryliodonium salts, triarylsulfonium salts, N-alkoxypyridinium (azinium) salts and the like are preferably used. Ferrocene, iron arene complexes: can generate active radicals reductively.

(B) Compound which is oxidized to generate an active radical Alkyl ate 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 CX 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. Specifically, for example, ethanolamines, N-
Examples include phenylglycine, N-trimethylsilylmethylaniline and the like. Sulfur- and tin-containing compounds: Compounds in which the nitrogen atom of the above-mentioned amines is replaced with a sulfur atom or a tin atom can generate an active radical by the same action. Compounds having an SS bond are also known to be sensitized by SS cleavage.

Α-Substituted methylcarbonyl compound: An active radical can be generated by the cleavage of carbonyl-α carbon bond by oxidation. In addition, those obtained by converting carbonyl to oxime ether also show the same action. In particular,
2-alkyl-1- [4- (alkylthio) phenyl]
-2-morpholinopronones-1 and oxime ethers obtained by reacting these with hydroxyamines and then etherifying N-OH. Sulfinates: Active radicals can be generated reductively. Specific examples include sodium arylsulfin and the like.

(C) Compounds that react with radicals to convert them into highly active radicals or act as chain transfer agents: For example, compounds having SH, PH, SiH, and GeH in the molecule are used. These can generate a radical by donating hydrogen to a low-activity radical species, or can generate a radical by being oxidized and then deprotonated. Specific examples include 2-mercaptobenzimidazoles.

Many more specific examples of these co-sensitizers are described in, for example, JP-A-9-236913 as additives for the purpose of improving sensitivity. Can also be applied.

(F-2) Colorant, etc. Further, a dye or pigment may be added for the purpose of coloring the photosensitive layer. As a result, it is possible to improve the so-called plate inspection, such as the visibility of the printing plate after plate making and the suitability for an image density measuring device. As many colorants, pigments are particularly preferable because many dyes lower the sensitivity of the photopolymerizable photosensitive layer. Specific examples include phthalocyanine pigments, azo pigments, carbon black, pigments such as titanium oxide, ethyl violet,
There are dyes such as crystal violet, azo dyes, anthraquinone dyes and cyanine dyes. Dyes and pigments are added in an amount of about 0.5% to about 5% by weight of the total composition.
Is preferred.

(F-3) Other Additives The photosensitive layer according to the present invention may further comprise an inorganic filler, other plasticizers, and an ink deposit on the surface of the photosensitive layer in order to improve the physical properties of the cured film. Known additives such as a sensitizer that can be improved may be added.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin and the like. A binder was used. In this case, it can be added in an amount of 10% by weight or less based on the total weight of the compound having an ethylenically unsaturated double bond and the binder.

Further, a UV initiator, a ripening crosslinking agent, etc. can be added to enhance the effect of heating and exposure after development for the purpose of improving the film strength (printing durability) described later. In addition, it is possible to provide an additive and an intermediate layer for improving the adhesion between the photosensitive layer and the support and for improving the development and removability of the unexposed photosensitive layer. For example, a compound having a diazonium structure or a phosphone compound, such as a compound having a relatively strong interaction with the substrate or an undercoat, the adhesion is improved,
The printing durability can be increased, while the addition or undercoating of a hydrophilic polymer such as polyacrylic acid or polysulfonic acid improves the developability of the non-image area and improves the stain resistance.

Next, other layers optionally provided in the lithographic printing plate precursor according to the invention will be described. [Protective layer] The lithographic printing plate precursor according to the invention is usually subjected to exposure in the air.
It is preferable to provide a protective layer. The protective layer prevents low-molecular compounds such as oxygen and basic substances present in the atmosphere that inhibit the image forming reaction caused by exposure in the photosensitive layer from being mixed into the photosensitive layer, and enables exposure in the atmosphere. I do. Therefore, the desired properties of such a protective layer is that the permeability of low molecular compounds such as oxygen is low, and further, the transparency of light used for exposure is good, and the adhesion with the photosensitive layer is excellent. In addition, it is desirable that it can be easily removed in a developing step after exposure.

Such a device for the protective layer has been conventionally devised, which is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used, and specifically, polyvinyl alcohol, polyvinylpyrrolidone, acidic celluloses, gelatin, gum arabic, and polystyrene. Although water-soluble polymers such as acrylic acid are known, use of polyvinyl alcohol as a 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, or an acetal as long as it contains an unsubstituted vinyl alcohol unit for obtaining necessary oxygen barrier properties and water solubility. Similarly, a part thereof may have another copolymer component.

Specific examples of polyvinyl alcohol include 7
1-100% hydrolyzed, molecular weight 300-240
A range of 0 can be given. Specifically, Kuraray's PVA-105, PVA-110, PVA
A-117, PVA-117H, PVA-120, PV
A-124, PVA-124H, PVA-CS, PVA
-CST, PVA-HC, PVA-203, PVA-2
04, PVA-205, PVA-210, PVA-21
7, PVA-220, PVA-224, PVA-217
EE, PVA-217E, PVA-220E, PVA-
224E, PVA-405, PVA-420, PVA-
613 and L-8.

The components of the protective layer (selection of PVA, use of additives), the amount of coating, etc. are selected in consideration of fogging properties, adhesion, and scratch resistance in addition to oxygen blocking properties and development removability. Generally, the higher the hydrolysis rate of the PVA used (the higher the content of unsubstituted vinyl alcohol units in the protective layer) and the thicker the film thickness, the higher the oxygen barrier property, which is advantageous in terms of sensitivity. However, when the oxygen-barrier property is extremely increased, there arises a problem that an unnecessary polymerization reaction occurs during production or raw storage, and unnecessary fogging and thickening of an image occur during image exposure. Further, the adhesion to the image area and the scratch resistance are also extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on a lipophilic polymer layer, film peeling due to insufficient adhesive force tends to occur, and the peeled portion causes defects such as poor film curing due to inhibition of oxygen polymerization.

On the other hand, various proposals have been made to improve the adhesiveness between these two layers. For example, US Patent No. 2
No. 92,501 and U.S. Pat. No. 44,563, an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer or the like is mixed in a hydrophilic polymer mainly composed of polyvinyl alcohol in an amount of 20 to 60% by weight. It is described that sufficient adhesiveness can be obtained by laminating on a polymer layer. Any of these known techniques can be applied to the protective layer in the present invention. Regarding the method of applying such a protective layer,
For example, U.S. Pat. No. 3,458,311;
No. 49729.

Further, other functions can be imparted to the protective layer. For example, it excels in the transmission of light of the wavelength used for exposure,
Addition of a coloring agent (such as a water-soluble dye) that can efficiently absorb light having a wavelength that does not contribute to image formation can further enhance the suitability for safelight without lowering the sensitivity.

[Support] The support used in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, plastic (for example,
Paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate) laminated with polyethylene, polypropylene, polystyrene, etc. Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.). These are single component sheets such as resin films and metal plates,
The laminate may be a laminate of two or more materials, for example, such as the above-described metal-laminated or vapor-deposited paper or plastic film, or a laminated sheet of different types of plastic films.

As the support, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate which has good dimensional stability and is relatively inexpensive is particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of foreign elements in the alloy is at most 10% by weight
It is as follows. Aluminum which is particularly preferred in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate,
About 0.1 to 0.6 mm, preferably 0.15 to
It is 0.4 mm, particularly preferably 0.2 to 0.3 mm.

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

The anodizing treatment conditions vary depending on the electrolyte to be used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight solution, the liquid temperature is 5 to 70.degree.
Current density 5 to 60 A / dm ^2, voltage 1 to 100 V, which is an electrolyzing time of 10 seconds to 5 minutes. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide coating is less than 1.0 g / m ² , the printing durability is insufficient, and the non-image area of the lithographic printing plate is easily damaged, and the ink adheres to the damaged area during printing. "Scratch dirt" is likely to occur. Although such anodizing treatment is performed on a surface used for printing of the support of lithographic printing plates, the back around the electric lines of force, 0.01 to 3 g / m ² on the back surface
Is generally formed.

The hydrophilizing treatment of the support surface is performed after the anodic oxidation treatment, and a conventionally known treatment method is used. As such a hydrophilic treatment,
U.S. Pat. Nos. 2,714,066 and 3,181,4
No. 61, No. 3,280,734 and No. 3,902,7
No. 34 discloses an alkali metal silicate (for example, an aqueous solution of sodium silicate). In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, Japanese Patent Publication No. 36-22
No. 063, and potassium fluoride zirconate disclosed in U.S. Pat. Nos. 3,276,868 and 4,15.
For example, a method of treating with polyvinyl phosphonic acid as disclosed in Japanese Patent Nos. 3,461 and 4,689,272 is used.

On the back surface of the support, a back coat is provided if necessary. Examples of such a back coat include a coating comprising a metal oxide obtained by hydrolyzing and polycondensing an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. Layers are preferably used. Among these coating layers, Si (OCH ₃ ) ₄ , Si (OC
_{2 H 5) 4, Si (} OC 3 H 7) 4, Si (OC
Alkoxy compounds of silicon such as ₄ H ₉ ) ₄ are inexpensive and readily available, and a coating layer of a metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

[Exposure] As described above, the planographic printing plate precursor of the invention can be prepared. This lithographic printing plate precursor is image-exposed by a solid-state laser and a semiconductor laser that emit infrared light having a wavelength of 760 nm to 1200 nm. Scanning exposure for image formation can be performed using a known device. As the exposure apparatus, an apparatus such as an inner drum system, an outer drum system, and a flat head system can be selected and used. In the lithographic printing plate precursor according to the present invention, the polymerization reaction of undesired unexposed portions due to low-energy exposure is suppressed by a combination of a high-sensitivity specific polymerization initiator and a polymerization inhibitor. It is also suitable for an exposure process and the like, and when applied to such a process, the effect is remarkable.

In the present invention, the developing treatment may be performed immediately after the laser irradiation, but it is preferable to perform the heating treatment between the laser exposure step and the developing step. The heat treatment is preferably performed in a range of 80 ° C. to 150 ° C. for 10 seconds to 5 minutes. By this heat treatment, the laser energy required for recording at the time of laser irradiation can be reduced.

[Development] The lithographic printing plate precursor according to the invention is usually subjected to image exposure, and then the unexposed portions of the photosensitive layer are removed with a developing solution to form a lithographic printing plate. Preferred developers for use in making the lithographic printing plate precursor according to the invention include those described in JP-B-57-7427, such as sodium silicate, potassium silicate,
Sodium hydroxide, potassium hydroxide, lithium hydroxide,
Inorganic alkaline agents such as tribasic sodium phosphate, dibasic sodium phosphate, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, aqueous ammonia, and monoethanolamine or diethanolamine An aqueous solution of a suitable organic alkali agent is suitable. When the concentration of such an alkaline solution is 0.1
-10% by weight, preferably 0.5-5% by weight.

Further, such an alkaline aqueous solution includes:
If necessary, a small amount of a surfactant or an organic solvent such as benzyl alcohol, 2-phenoxyethanol or 2-butoxyethanol can be contained. For example, those described in U.S. Pat. Nos. 3,375,171 and 3,615,480 can be mentioned. Further, Japanese Unexamined Patent Publication No.
No. 0-26601, No. 58-54341, Tokubo Sho56
The developing solutions described in JP-A-39464 and JP-A-56-42860 are also excellent. The composition used in the photosensitive layer of the present invention can be made soluble in neutral water or weakly alkaline water by using a highly water-soluble composition, but a lithographic printing plate having such a configuration can be used. The original plate can be loaded on a printing machine, exposed and developed on the machine, and then printed as it is.

The lithographic printing plate obtained as described above can be subjected to a printing step after coating with a desensitizing gum if desired. Is subjected to a burning process. When burning a lithographic printing plate, before burning,
No. 2518, No. 55-28062, JP-A-62-3
It is preferable to treat with a surface-regulating liquid as described in JP-A Nos. 1859 and 61-159655. As a method, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied on a lithographic printing plate, or a method in which the printing plate is immersed in a vat filled with the surface conditioning solution and applied, Application by an automatic coater or the like is applied. Further, it is more preferable to make the amount of the coating uniform with a squeegee or a squeegee roller after the coating.

The burn-processed lithographic printing plate can be subjected to a conventional treatment such as washing with water or gumming if necessary. When a liquid is used, a so-called desensitizing treatment such as gumming can be omitted. The lithographic printing plate obtained by such a process is set on an offset printing machine or the like and used for printing a large number of sheets.

[0136]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Examples 1 to 12) [Preparation of Substrate] An aluminum plate (material 1050) having a thickness of 0.3 mm was washed with trichlorethylene and degreased, and then a nylon brush and an aqueous suspension of 400 mesh pamistone were used. This grained surface was etched, washed with water, and further immersed in 20% nitric acid for 20 seconds, and washed with water. At this time, the etching amount of the grained surface is about 3 g / m.
^{Was 2} . Next, this plate was provided with a DC electrode oxide film of 3 g / m ² at a current density of 15 A / dm ² using 7% sulfuric acid as an electrolyte, washed with water and dried to prepare a substrate (A). The substrate (A) is treated with a 2% by weight aqueous solution of sodium silicate at 25 ° C. for 15 minutes.
Secondly, the substrate was washed with water to prepare a substrate (B).

[Formation of Intermediate Layer] Next, S
A liquid composition (sol solution) of Method G was prepared. <Sol solution composition>-130 g of methanol-20 g of water-16 g of 85 wt% phosphoric acid-50 g of tetraethoxysilane-60 g of 3-methacryloxypropyltrimethoxysilane The above compounds were mixed and stirred. An exotherm was observed in about 5 minutes. After reacting for 60 minutes, the content was transferred to another container, and 3000 g of methanol was added to obtain a sol solution. This sol solution was diluted with methanol / ethylene glycol = 9/1 (weight ratio) so that the amount of Si on the substrate [A] prepared as described above was 3 mg / m ^2. It was applied and dried at 100 ° C. for 1 minute to obtain a substrate [C].

[Formation of Photosensitive Layer] One of the substrates [A] to [C] prepared as described above was used as a support, and the surface thereof was coated with a photosensitive layer coating solution 1 or a photosensitive layer coating solution 2 having the following composition.
Was applied and dried at 115 ° C. for 1 minute to form a photosensitive layer of 1.4 g / m ² , thereby obtaining planographic printing plate precursors of Examples 1 to 12. (Photosensitive layer coating liquid 1)-Allyl methacrylate / methacrylic acid (38/17) Mw = 120,000 1.5 g-Pentaerythritol tetraacrylate 1.0 g-Infrared absorbent DX-1 (structure below) 0.1 g-Polymerization Initiator (compound described in Table 8) 0.15 g Polymerization inhibitor (compound described in Table 8) 0.02 g Fluorinated nonionic surfactant (MegaFac F-177P, Dainippon Ink and Chemicals, Inc.) 0.02 g ・ Dye in which the counter anion of Victoria Pure Blue BOH is changed to 1-naphthalene sulfonic acid anion 0.04 g ・ Methyl ethyl ketone 10 g ・ Methanol 7 g ・ 2-Methoxy-1-propanol 10 g

(Photosensitive Layer Coating Solution 2) Glycerin dimethacrylate hexamethylene diisocyanate urethane prepolymer 1.5 g Polyurethane resin (83/17), a condensate of the following diisocyanate and diol: 2.0 g [4,4'-diphenylmethane Diisocyanate (MDI) / hexamethylene diisocyanate (HDMI) / polypropylene glycol (weight average molecular weight 1000 PPG1000) / 2,2-bis (hydroxymethyl) propionic acid (DMPA): copolymerization molar ratio (MDI / HMDI / PPG1000 / DMPA = 40/10/15/35] ・ Infrared absorber DX-2 (structure below) 0.1 g ・ Polymerization initiator (compounds shown in Table 8) 0.15 g ・ Polymerization inhibitor (compounds shown in Table 8) ) 0.02g Nonionic surfactant (Megafac F-177P, manufactured by Dainippon Ink and Chemicals, Inc.) 0.02 g. Dye in which the counter anion of Victoria Pure Blue BOH is changed to 1-naphthalene sulfonic acid anion 0.04 g. Cyclohexanone 10 g. 17 g of 2-methoxy-1-propanol

[0141]

Embedded image

[0142]

[Table 8]

[Exposure / Development] The resulting lithographic printing plate precursor was exposed using a Creo Trendsetter 3244 exposure machine, and then a DN3C developer or a DP-4 developer and a rinser manufactured by Fuji Photo Film Co., Ltd. Liquid FR-3 (1:
7) An automatic processor (Fuji Photo Film Co., Ltd.)
(PS: 900 VR).
The developer used is shown in Table 8 above.

[Evaluation of Lithographic Printing Plate Precursor] (1. Sensitivity) The minimum exposure energy required to form an image in the exposed area and to enable ink deposition was measured and defined as sensitivity. It is determined that the smaller the value, the higher the sensitivity. (2. Remaining color in non-image area) After exposure and development, the obtained lithographic printing plate was used as a printing machine with R201 manufactured by Roland Co., Ltd.
, And visually checked whether or not a residual color due to the adhesion of the ink to the non-image portion occurred at the 100th sheet from the start of printing. Those for which ink has been adhered to the non-image areas are determined to have residual colors. The above evaluation results are also shown in Table 8 above. From the results shown in Table 8, the planographic printing plate precursor of the invention was excellent in recording sensitivity, and no undesired residual color in the non-image portion due to undesired curing of the unexposed portion was not observed.

Comparative Example 1 A lithographic printing plate precursor was obtained in the same manner as in Comparative Example 1 except that the polymerization inhibitor (P-1) was not added to the photosensitive layer coating solution 1 of Example 1. The same evaluation as in Example 1 was performed, and the results are shown in Table 8 above.
As is clear from Table 8, the recording sensitivity was equivalent to that of Example 1, but the residual color occurred in the non-image area.

Comparative Example 2 A lithographic printing plate precursor was obtained in the same manner as in Comparative Example 2 except that the polymerization inhibitor (P-3) was not added to the photosensitive layer coating solution 2 of Example 7. The same evaluation as in Example 1 was performed, and the results are shown in Table 8 above.
As is clear from Table 8, the recording sensitivity was equivalent to that of Example 7, but the residual color occurred in the non-image area.

Comparative Example 3 A lithographic printing plate precursor was obtained in the same manner as in Comparative Example 3 except that the polymerization inhibitor (N-1) was not added to the photosensitive layer coating solution 1 of Example 5. The same evaluation as in Example 1 was performed, and the results are shown in Table 8 above.
As is clear from Table 8, the recording sensitivity was equivalent to that of Example 5, but a residual color occurred in the non-image portion.

Comparative Example 4 Photosensitive Layer Coating Solution 2 of Example 12
A lithographic printing plate precursor was obtained in the same manner as in Comparative Example 4 except that no polymerization inhibitor (N-7) was added. The same evaluation as in Example 1 was performed, and the results are shown in Table 8 above. As is clear from Table 8, the recording sensitivity was equivalent to that of Example 1, but the residual color occurred in the non-image area.

(Comparative Example 5) Instead of the polymerization initiator (T-15) in the photosensitive layer coating solution 1 of Example 1, a polymerization initiator (AB-1) having the following structure, which is a general-purpose thermal polymerization initiator, was used. A lithographic printing plate precursor was obtained in the same manner except that the addition was performed, and Comparative Example 5 was obtained. The same evaluation as in Example 1 was performed.
It was also described in. As is clear from Table 8, when a general thermal polymerization initiator outside the scope of the present invention was used, it was found that the recording sensitivity was inferior to that of Example 1.

[0150]

Embedded image

(Examples 13 to 24, Comparative Examples 6 to 10) Polyvinyl alcohol (degree of saponification: 9) was formed on the photosensitive layers of the lithographic printing plate precursors obtained in Examples 1 to 12 and Comparative Examples 1 to 5.
8 mol%, polymerization degree: 550) was applied so that the coating amount after drying was 2 g / m ² and dried at 100 ° C. for 1 minute to form a protective layer on the photosensitive layer. Example 13
24. The lithographic printing plate precursors of Comparative Examples 6 to 10 were obtained. The obtained lithographic printing plate precursor was exposed and developed under the same conditions as in Examples 1 to 12 to produce a lithographic printing plate, and the sensitivity and the residual color of the non-image area were similarly evaluated. The results are shown in Table 8 above.

From the results in Table 8, it can be seen that even when a protective layer was provided on the photosensitive layer, Examples 1 to 12 having no protective layer were used.
The same tendency as in Comparative Examples 1 to 5 was observed, and the lithographic printing plate precursor according to the invention was excellent in sensitivity, and no residual color in the non-image portion due to undesired curing of the unexposed portion was not observed. In each of the comparative examples in which the inhibitor was not used in combination, a residual color was generated in the non-image area, and the comparative example using the general-purpose thermal polymerization initiator was inferior in sensitivity.

[0153]

The negative planographic printing plate precursor of the present invention is writable by an infrared laser, has excellent recording sensitivity, and is less likely to cause stains due to an undesired curing reaction in non-image areas. This has the effect of being excellent in image reproducibility.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03F 7/029 G03F 7/029 7/031 7/031 F term (Reference) 2H025 AA00 AA01 AA12 AB03 AC08 AD01 BC31 BC51 CA28 CA50 CC01 CC20 FA03 FA17 2H096 AA00 AA07 AA08 BA05 BA16 BA20 EA04 GA08 2H114 AA04 AA23 AA24 BA01 BA10 DA21 EA01 EA03

Claims (1)

[Claims] 1. A polymerization initiator selected from (A) a borate compound and a triazine compound on a support,
A heat comprising (B) a polymerization inhibitor, (C) a photothermal conversion agent, and (D) a compound having a polymerizable unsaturated group, and comprising a photosensitive layer recordable with an infrared laser. Mode-compatible negative type lithographic printing plate precursor.