JP2006085049A - Negative image forming material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative image forming material which is obtained by disposing a protective layer on a photosensitive layer and excels in sensitivity and scratch resistance, from which the protective layer is easily removed, and which can suppress adhesion to an adjacent image forming material or to protector paper (slip sheet) even during storage in piles and can form an image of excellent image quality. <P>SOLUTION: The negative image forming material is obtained by sequentially disposing on a support a photosensitive layer containing (A) a radical initiator and (B) a radical polymerizable compound and causing a curing reaction under light or heat, and a protective layer containing a water- and/or alkali-soluble polyurethane resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a negative image forming material, and more particularly to a negative image forming material that can be recorded with high sensitivity and is useful as a lithographic printing plate precursor.

Conventionally, a negative type image forming material having a recording layer that is cured by applying energy such as exposure and heating can form an image directly from digital data by, for example, scanning exposure. In addition to forming materials, it is used for various applications such as three-dimensional stereolithography, holography, color proofing, photoresists, color filters, and lithographic printing plate precursors.
As the lithographic printing plate precursor widely used as a typical one of these, a PS plate having a configuration in which an oleophilic photosensitive resin layer is provided on a hydrophilic support is widely used. After mask exposure (surface exposure) through a lithographic film, a desired printing plate was obtained by dissolving and removing non-image areas. In recent years, digitization techniques that electronically process, store, and output image information using a computer have become widespread. Various new image output methods corresponding to such digitization techniques have come into practical use. As a result, computer-to-plate (CTP) technology that scans highly directional light such as laser light according to digitized image information and directly produces a printing plate without going through a lithographic film is eagerly desired. Obtaining a lithographic printing plate precursor adapted to this is an important technical issue.

  As such a lithographic printing plate precursor capable of scanning exposure, an oleophilic photosensitive resin layer containing a photosensitive compound capable of generating active species such as radicals and bronzed acids by laser exposure on a hydrophilic support (hereinafter referred to as “lithographic printing plate precursor”) , Which is also referred to as a photosensitive layer) has been proposed and is already on the market. This lithographic printing plate precursor is laser-scanned based on digital information to generate active species, which causes physical or chemical changes in the photosensitive layer to insolubilize it, followed by development processing, thereby developing a negative lithographic printing plate Can be obtained. In particular, a photopolymerization type photosensitive layer containing a photopolymerization initiator excellent in photosensitive speed on a hydrophilic support, an ethylenically unsaturated compound capable of addition polymerization, and a binder polymer soluble in an alkali developer, and necessary Accordingly, a lithographic printing plate precursor provided with an oxygen-blocking protective layer is known (see, for example, Patent Documents 1 and 2). Such a lithographic printing plate precursor is excellent in productivity and further developed. From the advantages that it is simple and has good resolution and wearability, it has desirable printing performance.

However, in a lithographic printing plate precursor having a polymerization type photosensitive layer and a protective layer, depending on the mode of the protective layer, the sensitivity and scratch resistance may be reduced. Further, such a protective layer is removed at the time of development or by pre-washing before development. Even when the protective layer is removed by any step, the protective layer is a compound having a large film weight or a compound constituting the protective layer. Depending on the case, the concentration of the protective layer component in the developer or washing solution may occur, and there is a problem that problems such as dirt and piping are likely to occur in an image forming apparatus such as a developing device.
In addition, if the image portion of the photosensitive layer is insufficiently cured in the lithographic printing plate precursor, pre-washing as a step of removing the protective layer is performed by providing a protective layer, or not only the non-image but also the protective layer. As the development time increases compared to the case where a protective layer is not provided for removal, the image area is also damaged, and as a result, the printing durability is lowered by providing the protective layer. The current situation is that they have problems such as.
In addition, such a lithographic printing plate precursor is usually stored and transported in the state of a laminate formed by laminating a plurality of plates. At this time, the surface provided with the photosensitive layer and the back surface of the support directly In the original plate provided with the hydrophilic protective layer as described above for contact, it is difficult to peel off the support, particularly when stored under high humidity, and the workability is lowered or the adhered one is peeled off. When trying to do so, there was a problem that a part of the surface of the photosensitive layer side adhered to the support and a defect occurred in the photosensitive layer.

  When a problem occurs when the photosensitive layer is scratched, for example, when the surface of the photosensitive layer is mechanically scratched with a nail tip or a needle tip, the scratched portion remains as a film even after development processing. In such a case, although it is a non-image part, it is transferred to a printed matter as an image, and stains occur in the non-image part. In addition, if the protective layer is peeled off by scratches, the oxygen barrier property of the scratched part is lowered, the radical polymerization reaction in the exposed part is inhibited by oxygen, and the cured part of the exposed part, that is, the image part is insufficient and is removed by development. This causes a phenomenon that the printed image is lost in the image area. When a lithographic printing plate precursor that is easily scratched is used, image reproducibility is liable to be reduced, so that care is required for handling during normal printing plate conveyance, and handling is reduced. Even if care is taken at the time of conveyance, the phenomenon that a residual film appears on the plate holding portion of the plate setter, which is an exposure apparatus, cannot be suppressed, and the processing is necessary, resulting in a printing plate with poor handling properties.

In order to prevent such scratches, a protective paper (interleaf) is sandwiched when laminating the lithographic printing plate precursor so that it does not come into direct contact. However, in such a protective layer, particularly under high humidity conditions. If it is stored, it will be difficult to peel off the protective paper (interleaf), and the workability will be reduced, or when you try to peel off the bonded material, a part of the surface of the photosensitive layer will adhere to the support. There was a problem that the layer was defective.
JP 2000-347398 A JP 2003-84442 A

  The present invention has been made for the purpose of solving the above-described conventional problems, and the object of the present invention is to provide a protective layer on the photosensitive layer, which is excellent in sensitivity and scratch resistance. An object of the present invention is to provide a negative type image forming material from which a protective layer can be easily removed. A further object of the present invention is to prevent adhesion between adjacent image forming materials and between image forming materials and protective paper (interleaf) even when stored in an overlapping manner, thereby forming an image with excellent image quality. Another object of the present invention is to provide a negative type image forming material useful for a lithographic printing plate precursor.

As a result of intensive studies, the present inventor has found that the above problems can be solved by providing a protective layer containing a special resin on the surface of the recording layer, and has completed the present invention. That is, the negative image-forming material of the present invention comprises (A) a radical initiator and (B) a radical polymerizable compound on a support, a photosensitive layer that causes a curing reaction by light or heat, water and A protective layer containing a polyurethane resin soluble in alkaline water is provided in this order.
In the present invention, the polyurethane resin used for the protective layer is preferably water-soluble, and more preferably, the water-soluble polyurethane resin is a polyurethane resin having a carboxyl group in the side chain. Most preferably, the water-soluble polyurethane resin having a carboxyl group in the side chain is a water-soluble polyurethane resin in which part or all of the carboxyl groups present in the side chain are neutralized with an alkali.
The photosensitive layer preferably further contains (C) a sensitizing dye in addition to the (A) radical initiator and (B) radical polymerizable compound. When a recording layer having photosensitivity is used, it is preferable to use a dye having absorption in the infrared region as the (C) sensitizing dye.

Although the operation of the present invention is not clear, it is presumed as follows.
In the present invention, since a polyurethane resin soluble in water and / or alkaline water is used as a component of the protective layer provided on the photosensitive layer, a high-strength film is formed by the hydrogen bonding property of the main chain urethane group. It is formed. Since this film has a low dissolved oxygen amount in the film after the coating is formed and has a high oxygen barrier property from the outside, the inhibition of polymerization by oxygen of the radical polymerizable compound is effectively suppressed, and in the exposed portion of the photosensitive layer. A film having a high curing degree is formed by polymerization. For example, when used as a lithographic printing plate precursor, the formed image portion is sufficiently cured, and a printing plate having a high printing durability can be formed.
In addition, this high-strength coating film can provide a lithographic printing plate precursor having not only oxygen barrier properties but also a high physical protection function and excellent scratch resistance. For this reason, it is possible to suppress the above-described deterioration in image reproducibility and handling due to the occurrence of scratches.
In addition, this protective layer is excellent in coating properties and forms a hydrophobic film that is difficult to attract water after coating and drying, so it is less susceptible to environmental humidity, and even when stored repeatedly, the adjacent lithographic printing plate precursor Adhesion between each other and the planographic printing plate precursor and the protective paper (interleaf) can be suppressed.
Furthermore, since the polyurethane resin used in the present invention has a urethane group, which is a polar group, in the main chain, and preferably has a carboxyl group, more preferably a carboxylate group in the side chain, it has a high polarity such as water. Excellent compatibility with other media. Therefore, compared to polyvinyl alcohol resin, which is a water-soluble resin usually used for the protective layer, it has excellent water dispersibility, and when used in a lithographic printing plate precursor, development residue that becomes a problem in running suitability is generated. It also has the advantage of being difficult.

  According to the present invention, it is possible to provide a negative type image forming material that is excellent in sensitivity and scratch resistance and that can easily remove the protective layer. In addition, the negative type image forming material of the present invention can suppress adhesion between adjacent image forming materials or between the image forming material and a protective paper (interleaf) even when stored in an overlapped manner. Therefore, it is useful for a lithographic printing plate precursor.

Hereinafter, the present invention will be described in detail. The negative image-forming material of the present invention comprises (A) a radical initiator and (B) a radical polymerizable compound on a support, a photosensitive layer that causes a curing reaction by light or heat, water and / or A protective layer containing a polyurethane resin soluble in alkaline water is provided in this order. Hereinafter, the protective layer which is an important requirement of the negative type image forming material of the present invention will be described.
[Protective layer]
In the present invention, the protective layer provided on the photosensitive layer contains a polyurethane resin. The polyurethane resin soluble in water and / or alkaline water used in the present invention is not particularly limited as long as it is dissolved or dispersed in acidic to neutral to alkaline water. Especially, what is melt | dissolved or disperse | distributed with respect to neutral-alkaline water is preferable.

First, a polyurethane resin soluble in water and / or alkaline water (hereinafter referred to as a specific polyurethane resin as appropriate) that can be used in the present invention will be described.
The specific polyurethane resin used as an essential component for the heat mode-compatible negative image recording material of the present invention is at least one diisocyanate compound represented by the following general formula (2) and a diol represented by the general formula (3): A polyurethane resin having a structural unit represented by a reaction product with at least one compound as a basic skeleton.

OCN-X ⁰ -NCO (2)
HO-Y ⁰ -OH (3)
(In the formula, X ⁰ and Y ⁰ represent a divalent organic residue.)

Among the isocyanate compounds, a diisocyanate compound represented by the following general formula (4) is preferable.

OCN-L ¹ -NCO (4)

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

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

B) Diol compound As the diol compound, a polyether diol compound, a polyester diol compound, a polycarbonate diol compound and the like are widely used.
Examples of the polyether diol compound include compounds represented by the following formulas (5), (6), (7), (8) and (9), and random copolymerization of ethylene oxide and propylene oxide having a hydroxyl group at the terminal. Coalescence is mentioned.

In the formula, R ¹ represents a hydrogen atom or a methyl group, and X represents the following group.

  A, b, c, d, e, f, and g each represent an integer of 2 or more, and preferably an integer of 2 to 100.

Specific examples of the polyether diol compound represented by the formulas (5) and (6) include those shown below.
That is, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, di-1,2-propylene glycol, tri-1,2-propylene glycol, tetra-1, 2-propylene glycol, hexa-1,2-propylene glycol, di-1,3-propylene glycol, tri-1,3-propylene glycol, tetra-1,3-propylene glycol, di-1,3-butylene glycol, Tri-1,3-butylene glycol, hexa-1,3-butylene glycol, polyethylene glycol having a weight average molecular weight of 1000, polyethylene glycol having a weight average molecular weight of 1500, poly having a weight average molecular weight of 2000 Tylene glycol, polyethylene glycol with a weight average molecular weight of 3000, polyethylene glycol with a weight average molecular weight of 7500, polypropylene glycol with a weight average molecular weight of 400, polypropylene glycol with a weight average molecular weight of 700, polypropylene glycol with a weight average molecular weight of 1000, polypropylene glycol with a weight average molecular weight of 2000 , Polypropylene glycol having a weight average molecular weight of 3000, polypropylene glycol having a weight average molecular weight of 4000, and the like.

Specific examples of the polyether diol compound represented by the formula (7) include the following.
Sanyo Chemical Industries, Ltd. (trade name) PTMG650, PTMG1000, PTMG2000, PTMG3000, etc.

Specific examples of the polyether diol compound represented by the formula (8) include those shown below.
Sanyo Chemical Industries, Ltd. (trade name) New Pole PE-61, New Pole PE-62, New Pole PE-64, New Pole PE-68, New Pole PE-71, New Pole PE-74, New Pole PE-75, New Pole PE-78, New Pole PE-108, New Pole PE-128, New Pole PE-61, etc.

Specific examples of the polyether diol compound represented by the formula (9) include the following.
Sanyo Chemical Industries, Ltd. (trade name) New Pole BPE-20, New Pole BPE-20F, New Pole BPE-20NK, New Pole BPE-20T, New Pole BPE-20G, New Pole BPE-40, New Pole BPE-60, New Pole BPE-100, New Pole BPE-180, New Pole BPE-2P, New Pole BPE-23P, New Pole BPE-3P, New Pole BPE-5P, etc.

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

  Examples of the polyester diol compound include compounds represented by formulas (10) and (11).

In the formula, L ² , L ³ and L ⁴ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group, and L ⁵ represents a divalent aliphatic hydrocarbon group. Preferably, L ² , L ³ and L ⁴ each represent an alkylene group, an alkenylene group, an alkynylene group or an arylene group, and L ⁵ represents an alkylene group. In L ² , L ³ , L ⁴ , and L ⁵ , other functional groups that do not react with the isocyanate group such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group, or halogen atom are present. May be. nl and n2 are each an integer of 2 or more, preferably an integer of 2 to 100.

  As the polycarbonate diol compound, there is a compound represented by the formula (12).

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

  Specific examples of the diol compound represented by the formula (10), (11) or (12) include (Exemplary Compound G-1) to (Exemplary Compound G-18) shown below. N in the specific examples is an integer of 2 or more.

  The specific polyurethane resin (urethane binder) used when the image recording material of the present invention is used as a lithographic printing plate precursor is more preferably a polyurethane resin further having a carboxyl group. As the specific polyurethane resin suitably used, a structural unit represented by at least one diol compound of formulas (13), (14), and (15) and / or tetracarboxylic dianhydride may be used as a diol compound. Examples thereof include polyurethane resins having a structural unit derived from a ring-opened compound.

In the above formula, R ² is a hydrogen atom, a substituent (for example, a halogen atom such as a cyano group, a nitro group, —F, —Cl, —Br, —I, etc., —CONH ₂ , —COOR ³ , —OR ³ , — Each group includes NHCONHR ³ , —NHCOOR ³ , —NHCOR ³ , —OCONHR ³ (wherein R ³ represents an alkyl group having 1 to 10 carbon atoms and an aralkyl group having 7 to 15 carbon atoms). An alkyl group, an aralkyl group, an aryl group, an alkoxy group, or an aryloxy group, which may have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and an aryl group having 6 to 15 carbon atoms. Show. L ⁷ , L ⁸ and L ⁹ may be the same or different and may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy and halogeno groups are preferred). A divalent aliphatic or aromatic hydrocarbon group, preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms. . If necessary, L ⁷ , L ⁸ , and L ⁹ may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, ureido, and ether groups. A ring may be formed by 2 or 3 of R ² , L ⁷ , L ⁸ and L ⁹ .
Ar represents a trivalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms.

C) Diol compound containing a carboxyl group Specific examples of the diol compound having a carboxyl group represented by the formula (13), (14) or (15) include those shown below.
3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid, 2,2-bis (3-hydroxypropyl) propionic acid, Bis (hydroxymethyl) acetic acid, bis (4-hydroxyphenyl) acetic acid, 2,2-bis (hydroxymethyl) butyric acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid, tartaric acid, N, N-dihydroxyethylglycine N, N-bis (2-hydroxyethyl) -3-carboxy-propionamide and the like.

  In the present invention, preferred tetracarboxylic dianhydrides used for the synthesis of the specific polyurethane resin include those represented by the formulas (16), (17), and (18).

In the formula, L ¹⁰ is a divalent aliphatic or aromatic hydrocarbon which may have a single bond or a substituent (eg, alkyl, aralkyl, aryl, alkoxy, halogeno, ester, amide groups are preferred). Group, —CO—, —SO—, —SO ₂ —, —O— or —S—, preferably a single bond, a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, —CO—, —SO ₂ —, —O— or —S— is shown. R ⁴ and R ⁵ may be the same or different and each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, an alkoxy group or a halogeno group, preferably a hydrogen atom or an alkyl having 1 to 8 carbon atoms. Group, an aryl group having 6 to 15 carbon atoms, an alkoxy group having 1 to 8 carbon atoms or a halogeno group. Two of L ¹⁰ , R ⁴ and R ⁵ may be bonded to form a ring.

R ⁶ and R ⁷ may be the same or different and each represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or a halogeno group, preferably a hydrogen atom, an alkyl having 1 to 8 carbon atoms, or a carbon number 6-15 aryl groups are shown. Two of L ¹⁰ , R ⁶ and R ⁷ may combine to form a ring. L ¹¹ and L ¹² may be the same or different and each represents a single bond, a double bond or a divalent aliphatic hydrocarbon group, preferably a single bond, a double bond or a methylene group. A represents a mononuclear or polynuclear aromatic ring. An aromatic ring having 6 to 18 carbon atoms is preferable.

Specific examples of the compound represented by the formula (16), (17) or (18) include those shown below.
That is, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride, 2, 3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4′-sulfonyldiphthalic dianhydride, 2,2-bis (3 , 4-Dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 4,4 ′-[3,3 ′-(alkylphosphoryldiphenylene) -bis (iminocarbonyl) ] Diphthalic dianhydride,

Aromatic tetracarboxylic dianhydrides such as adducts of hydroquinone diacetate and trimetic anhydride, diacetyldiamine and trimetic anhydride; 5- (2,5-dioxotetrahydrofuryl) -3-methyl- 3-cyclohexsi-1,2-dicarboxylic acid anhydride (Dainippon Ink Chemical Co., Ltd., Epicron B-4400), 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1, Alicyclic tetracarboxylic dianhydrides such as 2,4,5-cyclohexanetetracarboxylic dianhydride and tetrahydrofuran tetracarboxylic dianhydride; 1,2,3,4-butanetetracarboxylic dianhydride, 1 Aliphatic tetracarboxylic dianhydrides such as 2,4,5-pentanetetracarboxylic dianhydride.

Examples of a method for introducing a structural unit derived from a compound obtained by ring-opening these tetracarboxylic dianhydrides with a diol compound into a polyurethane resin include the following methods.
a) A method of reacting an alcohol-terminated compound obtained by ring-opening tetracarboxylic dianhydride with a diol compound and a diisocyanate compound.
b) A method of reacting an alcohol-terminated urethane compound obtained by reacting a diisocyanate compound under an excess of a diol compound with tetracarboxylic dianhydride.

Specific examples of the diol compound used at this time include the following compounds.
That is, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 1,3-butylene glycol, 1,6-hexanediol, 2-butene- 1,4-diol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A, hydrogenated Bisphenol F, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, bisphenol F ethylene oxide adduct, bisphenol F pro Renoxide adduct, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, hydroquinone dihydroxyethyl ether, p-xylylene glycol, dihydroxyethyl sulfone, bis (2-hydroxyethyl) -2, Examples include 4-tolylene dicarbamate, 2,4-tolylene-bis (2-hydroxyethylcarbamide), bis (2-hydroxyethyl) -m-xylylenedicarbamate, and bis (2-hydroxyethyl) isophthalate.

D) Other diol compounds Furthermore, in the synthesis of the specific polyurethane resin, other diol compounds which do not have a carboxyl group and may have other substituents which do not react with isocyanate can be used in combination.
Examples of such diol compounds include those shown below.

^{HO-L 13 -O-CO-} L 14 -CO-O-L 13 -OH (19)
^{HO-L 14 -CO-O-} L 13 -OH (20)

In the formula, L ¹³ and L ¹⁴ may be the same or different, and each may be a substituent (for example, an alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, -F, -Cl, -Br, -I A divalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group, which may have a group such as a halogen atom. If necessary, L ¹³ and L ¹⁴ may have another functional group that does not react with an isocyanate group, such as a carbonyl group, an ester group, a urethane group, an amide group, or a ureido group. Note that L ¹³ and L ¹⁴ may form a ring.

  Specific examples of the compound represented by the formula (19) or (20) include (Exemplary Compound G-19) to (Exemplary Compound G-35) shown below.

  Also, diol compounds represented by the following formulas (21) and (22) can be preferably used.

In the formula, R ⁸ and R ⁹ may be the same or different and each is an alkyl group which may have a substituent, and c represents an integer of 2 or more, preferably an integer of 2 to 100.

Specific examples of the diol compound represented by the formulas (21) and (22) include those shown below.
That is, as the formula (21), ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1, Examples of the formula (22) such as 8-octanediol include the compounds shown below.

  Moreover, the diol compound shown by following formula (23) and Formula (24) can also be used conveniently.

^{HO-L 15 -NH-CO-} L 16 -CO-NH-L 15 -OH (23)
^{HO-L 16 -CO-NH-} L 15 -OH (24)

In the formula, L ¹⁵ and L ¹⁶ may be the same as or different from each other, and each may have a substituent (for example, alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, —Br, —I), A divalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group which may have a group. If necessary, L ¹⁵ and L ¹⁶ may have another functional group that does not react with an isocyanate group, for example, carbonyl, ester, urethane, amide, ureido group and the like. A ring may be formed by L ¹⁵ and L ¹⁶ .

  Specific examples of the compound represented by formula (23) or (24) include those shown below (Exemplary Compound G-36) to (Exemplary Compound G-45).

  Furthermore, diol compounds represented by the following formulas (25) and (26) can also be suitably used.

^{HO-Ar 2 - (L 17} -Ar 3) n-OH (25)
^{HO-Ar 2 -L 17 -OH (} 26)

In the formula, L ¹⁷ represents a divalent aliphatic hydrocarbon group which may have a substituent (eg, alkyl, aralkyl, aryl, alkoxy, aryloxy and halogeno groups are preferable). If necessary, L ¹⁷ may have another functional group that does not react with an isocyanate group, such as an ester, urethane, amide, or ureido group. Ar ² and Ar ³ may be the same or different and each represents a divalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms. n represents an integer of 0 to 10.

Specific examples of the diol compound represented by the above formula (25) or (26) include those shown below.
That is, catechol, resorcin, hydroquinone, 4-methylcatechol, 4-t-butylcatechol, 4-acetylcatechol, 3-methoxycatechol, 4-phenylcatechol, 4-methylresorcin, 4-ethylresorcin, 4-t-butyl Resorcin, 4-hexyl resorcin, 4-chloro resorcin, 4-benzyl resorcin, 4-acetyl resorcin, 4-carbomethoxy resorcin, 2-methyl resorcin, 5-methyl resorcin, t-butyl hydroquinone, 2,5-di- t-butylhydroquinone, 2,5-di-t-amylhydroquinone, tetramethylhydroquinone, tetrachlorohydroquinone, methylcarboaminohydroquinone, methylureidohydroquinone, methylthiohydroquinone, benzonor Runen-3,6-diol, bisphenol A,

Bisphenol S, 3,3′-dichlorobisphenol S, 4,4′-dihydroxybenzophenone, 4,4′-dihydroxybiphenyl, 4,4′-thiodiphenol, 2,2′-dihydroxydiphenylmethane, 3,4-bis (P-hydroxyphenyl) hexane, 1,4-bis (2- (p-hydroxyphenyl) propyl) benzene, bis (4-hydroxyphenyl) methylamine, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,5-dihydroxyanthraquinone, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 2-hydroxy-3,5-di-t-butylbenzyl alcohol, 4 -Hydroxy-3,5-di-t- Chill benzyl alcohol, 4-hydroxy phenethyl alcohol, 2-hydroxyethyl-4-hydroxybenzoate, 2-hydroxyethyl-4-hydroxyphenyl acetate, resorcinol mono-2-hydroxyethyl ether.
Diol compounds represented by the following formula (27), formula (28) or formula (29) can also be suitably used.

In the formula, R ¹⁰ is a hydrogen atom, a substituent (for example, cyano, nitro, halogen atom (—F, —Cl, —Br, —I), —CONH ₂ , —COOR ^ll , —OR ¹¹ , —NHCONHR ¹¹ , Each group includes —NHCOOR ^ll , —NHCOR ¹¹ , —OCONHR ¹¹ , —CONHR ¹¹ (wherein R ¹¹ represents an alkyl group having 1 to 10 carbon atoms and an aralkyl group having 7 to 15 carbon atoms). .) May be an alkyl, aralkyl, aryl, alkoxy, or aryloxy group, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 15 carbon atoms. L ¹⁸ , L ¹⁹ and L ²⁰ may be the same or different from each other and may have a single bond or a substituent (for example, alkyl, aralkyl, aryl, alkoxy and halogen groups are preferred). A divalent aliphatic or aromatic hydrocarbon group, preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms. . If necessary, L ¹⁸ , L ¹⁹ , and L ²⁰ may have other functional groups that do not react with isocyanate groups, such as carbonyl, ester, urethane, amide, ureido, and ether groups. ^{Incidentally, R 10, L 18, L} 19, may form a ring, two or three of L ^20. Ar represents a trivalent aromatic hydrocarbon group which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms. Z ₀ represents the following group.

Here, R ¹² and R ¹³ may be the same or different and each represents a hydrogen atom, sodium, potassium, an alkyl group or an aryl group, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a carbon atom 6 to 15 aryl groups are shown.

The diol compound having the phosphonic acid, phosphoric acid and / or ester group thereof represented by the formula (27), (28) or (29) is synthesized, for example, by the method shown below.
After protecting the hydroxy group of the halogen compound represented by the following general formulas (30), (31), and (32) as necessary, phosphonate esterification is performed by the Michaelis-Arbuzov reaction represented by the formula (33). If necessary, synthesis is performed by hydrolysis with hydrogen bromide or the like.

In the formula, R ¹⁴ , L ²¹ , L ²² , L ²³ and Ar are as defined in the formulas (27), (28) and (29). R ¹⁵ represents an alkyl group or an aryl group, preferably an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 15 carbon atoms. R ¹⁶ is a residue excluding X ¹ in formulas (30), (31), and (32), and X ¹ represents a halogen atom, preferably Cl, Br, or I.

  Further, synthesis is performed by a method of hydrolysis after reaction with phosphorus oxychloride represented by the formula (34).

In the formula, R ¹⁷ has the same meaning as in formula (33), and M represents a hydrogen atom, sodium or potassium.

  When the polyurethane resin of the present invention has a phosphonic acid group, a diol having a diisocyanate compound represented by the general formula (4) and a phosphonic acid ester group represented by the formula (27), (28), or (29) It may be synthesized by reacting a compound to form a polyurethane resin, followed by hydrolysis with hydrogen bromide or the like.

  Further, the amino group-containing compounds (35) and (36) shown below are reacted with the diisocyanate compound represented by the general formula (4) in the same manner as the diol compound to form a urea structure, and are incorporated into the structure of the polyurethane resin. May be.

In the formula, R ¹⁸ and R ¹⁹ may be the same or different, such as a hydrogen atom, a substituent (for example, alkoxy, halogen atom (—F, —Cl, —Br, —I), ester, carboxyl group, etc. Each group is included) may be an alkyl, aralkyl or aryl group which may have a hydrogen atom, preferably an alkyl or carbon having 1 to 8 carbon atoms which may have a carboxyl group as a substituent. 6 to 15 aryl groups are shown. L ²⁴ has a substituent (for example, each group such as alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, —Br, —I), carboxyl group, etc.). And a divalent aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic group. If necessary, L ²⁴ may have another functional group that does not react with an isocyanate group, for example, a carbonyl group, an ester group, a urethane group, an amide group, or the like. Two of R ¹⁸ , L ²⁴ and R ¹⁹ may form a ring.

Specific examples of the compounds represented by the general formulas (35) and (36) include those shown below.
That is, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, dodecamethylenediamine, propane-1,2-diamine, bis (3-aminopropyl) methylamine, 1 , 3-bis (3-aminopropyl) tetramethylsiloxane, piperazine, 2,5-dimethylpiperazine, N- (2-aminoethyl) piperazine, 4-amino-2,2-6,6-tetramethylpiperidine, N Aliphatic diamine compounds such as N, dimethylethylenediamine, lysine, L-cystine, isophoronediamine;

o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-tolylenediamine, benzidine, o-ditoluidine, o-dianisidine, 4-nitro-m-phenylenediamine, 2,5-dimethoxy-p- Such as phenylenediamine, bis- (4-aminophenyl) sulfone, 4-carboxy-o-phenylenediamine, 3-carboxy-m-phenylenediamine, 4,4′-diaminophenyl ether, 1,8-naphthalenediamine, etc. Aromatic diamine compounds;
2-aminoimidazole, 3-aminotriazole, 5-amino-1H-tetrazole, 4-aminopyrazole, 2-aminobenzimidazole, 2-amino-5-carboxytriazole, 2,4-diamino-6-methyl-S -Heterocyclic amine compounds such as triazine, 2,6-diaminopyridine, L-histidine, DL-tryptophan, adenine and the like;

Ethanolamine, N-methylethanolamine, N-ethylethanolamine, 1-amino-2-propanol, 1-amino-3-propanol, 2-aminoethoxyethanol, 2-aminothioethoxyethanol, 2-amino-2- Methyl-1-propanol, p-aminophenol, m-aminophenol, o-aminophenol, 4-methyl-2-aminophenol, 2-chloro-4-aminophenol, 4-methoxy-3-aminophenol, 4- Hydroxybenzylamine, 4-amino-1-naphthol, 4-aminosalicylic acid, 4-hydroxy-N-phenylglycine, 2-aminobenzyl alcohol, 4-aminophenethyl alcohol, 2-carboxy-5-amino-1-naphthol, Aminoal such as L-tyrosine Lumpur or aminophenol compounds.

  The specific polyurethane resin that can be used in the present invention is synthesized by adding the above-mentioned isocyanate compound and diol compound in an aprotic solvent to a known catalyst having an activity corresponding to the reactivity and heating. The molar ratio of the diisocyanate and the diol compound to be used is preferably 0.8: 1 to 1.2: 1. When an isocyanate group remains at the polymer terminal, the final treatment is performed by treatment with alcohols or amines. Thus, it is synthesized in a form in which no isocyanate group remains.

  As the specific polyurethane resin according to the present invention, those having an unsaturated bond at the polymer terminal, main chain, and side chain are also preferably used. By having an unsaturated bond, a crosslinking reaction occurs between the polymerizable compound or the polyurethane resin. As a result, the strength of the photocured product is increased, and when applied to a lithographic printing plate, a plate material having excellent printing durability is obtained. be able to. As the unsaturated bond, a carbon-carbon double bond is particularly preferable because of the ease of the crosslinking reaction.

  As a method for introducing an unsaturated group into the polymer terminal, there are the following methods. That is, when an isocyanate group remains at the polymer terminal in the process of synthesizing the polyurethane resin, an alcohol or amine having an unsaturated group may be used in the process of treating with an alcohol or amine. Specific examples of such compounds include the following.

As a method for introducing an unsaturated group into the main chain or side chain, there is a method of using a diol compound having an unsaturated group for the synthesis of a polyurethane resin. Specific examples of the diol compound having an unsaturated group include the following compounds.
A diol compound represented by formula (37) or (38). Specific examples include the following.

  Specific examples of the diol compound represented by the formula (37) include 2-butene-1,4-diol, and the diol compound represented by the formula (38) includes cis-2-butene-1,4. -Diol, trans-2-butene-1,4-diol, and the like.

  A diol compound having an unsaturated group in the side chain. Specific examples include the compounds shown below.

  The specific polyurethane resin according to the present invention preferably contains an aromatic group such as a benzene ring in the main chain and / or side chain. As a result, a protective layer having a high strength film can be provided, the oxygen barrier property and physical function of the protective layer can be increased, and a lithographic printing plate precursor having high printing durability, excellent scratch resistance and adhesion suppression can be provided. it can. The more preferable content of the aromatic group is 10 to 80% by weight, more preferably 20 to 60% by weight in the polyurethane resin.

The specific polyurethane resin according to the present invention is preferably a polyurethane resin having a carboxyl group. Thereby, developability and precipitation (debris generation) in the developer can be effectively suppressed. The content of the carboxyl group is preferably 0.4 meq / g or more, and more preferably 0.7 meq / g to 3.5 meq / g.
Such a specific polyurethane resin is preferably one in which some or all of the carboxyl groups are neutralized with a base (side chain carboxylate). Thereby, developability is further improved. As a method for introducing a carboxylate into the side chain, use the above-mentioned carboxyl group-containing diol compound neutralized with an inorganic base such as sodium hydroxide or an organic base such as tetraethylammonium hydroxide or triethylamine. The polymer can be synthesized by polymerizing the side chain carboxyl group-containing polyurethane resin and then neutralizing with these bases. Preferable examples of the base to be used include alkali metal hydrides, hydroxides or carbonates, organic ammonium compound hydroxides, organic amine compounds, and metal alkoxide compounds.

Preferred examples of alkali metal hydrides, hydroxides or carbonates include sodium hydride, calcium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, sodium carbonate, Examples include potassium hydrogen carbonate and sodium hydrogen carbonate.
Preferable examples of the hydroxide of the organic ammonium compound include tetraethylammonium hydroxide.
Preferable examples of the organic amine compound include trimethylamine, triethylamine, diethylmethylamine, tributylamine, triisobutylamine, trihexylamine, trioctylamine, N, N-dimethylcyclohexylamine, N, N-diethylcyclohexylamine, N- Methyldicyclohexylamine, N-ethyldicyclohexylamine, pyrrolidine, 1-methylpyrrolidine, 2,5-dimethylpyrrolidine, piperidine, 1-methylpiperidine, 2,2,6,6-tetramethylpiperidine, piperazine, 1,4-dimethyl Piperazine, quinuclidine, 1,4-diazabicyclo [2,2,2] -octane, hexamethylenetetramine, morpholine, 4-methylmorpholine, pyridine, picoline, 4-dimethylaminopyridine, Cytidine, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU), N, N'-dicyclohexylcarbodiimide (DCC), diisopropylethylamine, Schiff base, and the like.
Preferable examples of the metal alkoxide compound include sodium methoxide, sodium ethoxide, potassium t-butoxide and the like. These bases may be used alone or in combination of two or more.

When some or all of the carboxyl groups present in the side chain are neutralized with alkali, the carboxylate counter cation includes monovalent metal cations such as sodium cation, potassium cation and lithium cation, and tetraethyl Monovalent organic ammonium cations such as ammonium are preferred.
The ratio of the side chain carboxyl groups neutralized to form carboxylates is preferably 5% or more, more preferably 40% or more, and most preferably 80% or more of the total amount of carboxyl groups. preferable.
The molecular weight of the specific polyurethane resin resin is preferably 1,000 or more in terms of weight average molecular weight, and more preferably in the range of 10,000 to 200,000.

  Hereinafter, specific polyurethane resins (polymer compounds No. 1 to No. 31) that can be suitably used in the present invention are shown together with their partial structures, polymerization molar ratios, and weight average molecular weights (described as Mw in parentheses). However, the present invention is not limited to this. In addition, Mw written together with the partial structure shows the molecular weight of the partial structure. 1 represents that polyethylene glycol having a weight average molecular weight of 2,000 is used.

The specific polyurethane resin according to the present invention may be used alone or in combination of two or more.
In addition to the polyurethane resin, other polymer compounds can be mixed and used as long as the effects of the present invention are not impaired. For example, known materials described in detail in US Pat. No. 3,458,311 and Japanese Patent Publication No. 55-49729 can be used. A material that can be used for such a protective layer is preferably selected from natural polymers and synthetic polymers that can be dissolved in water or an aqueous alkali solution, and can form a film when coated and dried. Specifically, for natural polymers, gum arabic, water-soluble soybean polysaccharide, fiber derivatives (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.), modified products thereof, white dextrin, pullulan, enzymatically degraded etherified dextrin, etc. Synthetic polymers include polyvinyl alcohol, its butyral derivative, polyacrylic acid, its alkali metal salt or amine salt, polyacrylic acid copolymer, its alkali metal salt or amine salt, polymethacrylic acid, its alkali metal salt or amine Salt, vinyl alcohol / acrylic acid copolymer and alkali metal salt or amine salt thereof, polyacrylamide, copolymer thereof, polyhydroxyethyl acrylate, polyvinyl pyrrolidone, copolymer thereof, polyvinyl methyl ether , Vinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, alkali metal salt or amine salt thereof, poly-2-acrylamido-2-methyl-1-propane Examples thereof include sulfonic acid copolymers and alkali metal salts or amine salts thereof.

Among these, it is preferable to use polyvinyl alcohol as a main component from the viewpoint of basic characteristics such as oxygen barrier properties and development removability. Examples of such polyvinyl alcohol include unmodified polyvinyl alcohol and acid-modified polyvinyl alcohol modified with carboxylic acid or a salt thereof, sulfonate, or the like. Among them, acid-modified polyvinyl alcohol with improved hydrophilicity is preferable from the viewpoint of developability. Specifically, for example, acid-modified polyvinyl alcohol such as itaconic acid or maleic acid-modified carboxy-modified polyvinyl alcohol or sulfonic acid-modified polyvinyl alcohol Is mentioned.
Further, the polyvinyl alcohol used in 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 in order to have necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components.

Specific examples of such polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a polymerization degree in the range of 300 to 2400. Specifically, KL-504, KL-506, KL-318, KL-118, KM-618, KM-118, SK-5102, PVA-105, PVA-110, PVA-117 made by Kuraray Co., Ltd. , 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, etc., NH-made by Nippon Synthetic Chemical Industry Co., Ltd. 26, NH-20, NH-18, N-300, NM-11, NL-05, AH-26, AH-22, AH- 7, A-300, C-500, P-610, AL-06, GH-23, GH-20, GH-17, GM-14, GM-14L, GL-05, GL-03, KH-20, KH-17, KM-11, KL-05, KL-03, KP-08, KP-06, NK-05, NH-17Q, NM-11Q, EG-40, EG-30, EG-25, EG- 05, NH-18S, GH-20S, GH-17S, GL-05S, T-330, T-330S, T-330H, T-330ST, T-350, T-230, T-215, T-HS- 1, K-210, L-7514, L-5407, Z-200, Z-200H, Z-210, Z-100, Z-220, F-78, L-0301, L-0302, L-3266, CKS-50 etc., manufactured by Denki Kagaku Kogyo Co., Ltd. -24E, K-17C, K-17E, K-05, H-24, H-20, H-17, H-12, B-33, B-24T, B-24, B-20, B-17R , B-17, B-05, B-04, NP-15, NP-20H, EP-120K, EP-240, PC-100, EP-130, D-100, F-300S, D-310, F -510S, MP-10, DR-828, W-100 etc. are mentioned.
In this case, the other polymer compound forming the protective layer is preferably 90% by weight or less, and more preferably 50% by weight or less in the total polymer compound including the specific polyurethane resin.

In the composition constituting the protective layer, various additives can be used in addition to the specific polyurethane resin and other polymer compounds described above as long as the effects of the present invention are not impaired.
Specifically, for example, as an additive, glycerin, dipropylene glycol or the like can be added in an amount corresponding to several mass% with respect to the polymer compound (polyvinyl alcohol). Such an additive can impart flexibility to the protective layer.
In addition, anionic surfactants such as sodium alkyl sulfate and sodium alkyl sulfonate; amphoteric surfactants such as alkylaminocarboxylate and alkylaminodicarboxylate; nonionic surfactants such as polyoxyethylene alkylphenyl ether; Several mass% can be added with respect to a high molecular compound (polyvinyl alcohol).

  In the protective layer according to the present invention, the adhesion to the photosensitive layer is also an extremely important factor in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer (including a specific polyurethane resin and polyvinyl alcohol used together if desired) is laminated on a lipophilic polymer layer (photosensitive layer), film peeling due to insufficient adhesive force is likely to occur. In the peeled portion, defects such as defective film hardening due to inhibition of oxygen polymerization are likely to occur. On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563 disclose an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer 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 the like and laminating on a polymerization layer (photosensitive layer). Any of these known techniques for improving the adhesion to the photosensitive layer can be applied to the protective layer in the invention.

The protective layer in the present invention preferably has a coating amount of 0.5 g / m ² or more from the viewpoint of scratch resistance. Further, from the viewpoint of oxygen barrier properties, scratch resistance, and development suitability, the coating amount is more preferably 1.0 to 3.0 g / m ² , more preferably 1.2 to 2.0 g / m ^2. m ² . In the present invention, the coating amount of the protective layer represents the coating amount after drying.

The protective layer of the present invention may function not only as an oxygen barrier and scratch resistance but also as an ablation preventing layer when exposed to a high-illuminance infrared laser.
In addition to the above, the properties desired for the protective layer in the present invention are preferably such that the transmission of light used for exposure is not substantially inhibited and the adhesiveness to the photosensitive layer is excellent.

  In the present invention, the composition component of the protective layer (selection of the polyurethane resin, selection of the water-soluble polymer compound to be used in combination, type of additive and presence / absence of use), and the coating amount are the content of the polyurethane resin and the coating amount of the protective layer. If it is within the above range, it can be selected as appropriate in consideration of fogging, adhesion and scratch resistance in addition to the desired oxygen barrier property and development removability.

The protective layer in the present invention can be usually formed by dissolving the above-described components necessary for a protective layer-forming coating solution in a solvent, and applying and drying the solution on a photosensitive layer formed on a support.
As a solvent used here, water is used as a main component, but from the viewpoint of coating physical property control such as surface tension and viscosity of the coating liquid and solubility control of the lower layer, alcohols such as methanol, and glycols such as glycerin. In addition, amides such as ethanolformamide and dimethyl sulfoxide can be mixed and used, but are not limited thereto.
The concentration of the above components (total solid content including additives) in the solvent is preferably 0.01 to 50 mass%, more preferably 1 to 20 mass%.

A surfactant may be added to the protective layer coating solution according to the present invention in order to improve coatability. Specific examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene laurate, polyoxyethylene stearamide, polyoxyethylene lauryl amine, polyoxyethylene polyoxypropylene Examples include ether, glycerol monourarate, sorbitan tristearate, sorbitan monopalmitate, polyoxyethylene sorbitan trioleate, alkylallyl ether formalin condensate, naphthalenesulfonic acid terformalin condensate and the like.
A preferable addition amount is 0.01 to 5% by mass, more preferably 0.1 to 3% by mass, in the above-described components (total solid content including additives) in the solvent.

  Various methods can be used as the coating method, such as bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, roll coating, and extrusion coating. Can be mentioned.

Furthermore, it is also a preferred embodiment to add an inorganic layered compound to the protective layer according to the present invention. By adding the compound, it is possible to further improve the adhesion suppressing effect without reducing the oxygen barrier property and the adhesion to the photosensitive layer.
The inorganic layered compound that can be suitably used is a particle having a thin tabular shape, for example, a general formula A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂ [wherein A is any of K, Na, and Ca, B and C are any of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. And mica groups such as natural mica and synthetic mica, talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by the general formula 3MgO.4SiO.H ₂ O.
In the mica group, examples of natural mica include muscovite, soda mica, phlogopite, biotite and sericite. Synthetic mica includes non-swelling mica such as fluor-phlogopite mica KMg ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 Si ₄ O ₁₀ ) F ₂ , and Na tetrasilicic mica NaMg _2.5 ( Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , montmorillonite Na or Li hectorite (Na, Li) _1/8 Mg _2/5 Li Examples thereof include swelling mica such as _1/8 (Si ₄ O ₁₀ ) F ₂ . Synthetic smectite is also useful.

In the present invention, among the inorganic layered compounds, fluorine-based swellable mica, which is a synthetic inorganic layered compound, is particularly useful. That is, this swellable synthetic mica and swellable viscosity minerals such as montmorillonite, saponite, hectorite, bentonite, etc. have a laminated structure composed of unit crystal lattice layers with a thickness of about 10 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 ⁺ , since the ionic radius is small, the bond between the layered crystal lattices is weak, 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 a strong 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 does not impair the smoothness of the coated surface or the transmittance of actinic rays. The larger the 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 image-forming material in the image-forming material is not deteriorated due to changes in humidity, and the storage stability is excellent.

The amount contained in the protective layer of the inorganic layered compound is relative to the amount of the binder used in the protective layer from the viewpoint of developing the effect of adding the inorganic layered compound and suppressing the occurrence of cracks in the coating film. The mass ratio is preferably 5/1 to 1/100.
Even when a plurality of kinds of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass ratio.

  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 weight of the swellable layered compound mentioned above as a preferred inorganic layered compound is added to 100 parts by weight 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 weight 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.

(Photosensitive layer)
The photosensitive layer of the image forming material of the present invention will be described. The photosensitive layer according to the present invention contains (A) a radical initiator, (B) a radical polymerizable compound, and (C) a sensitizing dye or (D) a binder polymer, if desired, and is light, heat, or both. A curing reaction is caused by applying energy such as. That is, the photosensitive layer in the region is cured by polymerization reaction or formation of a crosslinked structure by heating and exposure, and, for example, when used for a lithographic printing plate precursor, an unnecessary image portion is formed in an alkali developer. Each compound contained in the photosensitive layer of the present invention will be described in order.

[(A) radical initiator]
The radical initiator contained in the photosensitive layer in the present invention refers to a compound that generates radicals by light and / or heat energy and initiates and accelerates the polymerization reaction of the (B) radical polymerizable compound described later.
In the present invention, preferred radical initiators include (a) aromatic ketones, (b) onium salt compounds, (c) organic peroxides, (d) thio compounds, (e) hexaarylbiimidazole compounds, f) Ketoxime ester compounds, (g) borate compounds, (h) azinium compounds, (i) metallocene compounds, (j) active ester compounds, (k) compounds having a carbon halogen bond, and the like. Specific examples of the above (a) to (k) are given below, but the present invention is not limited to these.

(A) Aromatic Ketones (a) Aromatic ketones preferred as the radical initiator used in the present invention include “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” P. Fouassier, J. et al. F. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in Rabek (1993), p77-117. For example,

Is mentioned. Among them, examples of particularly preferred (a) aromatic ketones include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, for example, the following compounds.

  Examples of the α-substituted benzoin compounds described in JP-B-47-22326 include the following compounds.

  Examples thereof include benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, for example, the following compounds.

  Examples of the benzoin ethers described in JP-B-60-26403 and JP-A-62-181345 include the following compounds.

  Examples of the α-aminobenzophenones described in JP-B-1-34242, US Pat. No. 4,318,791, and European Patent 0284561A1, such as the following compounds.

  P-Di (dimethylaminobenzoyl) benzene described in JP-A-2-211452, for example, the following compounds may be mentioned.

  Examples of the thio-substituted aromatic ketone described in JP-A-61-194062 include the following compounds.

  The acylphosphine sulfide described in JP-B-2-9597, for example, the following compounds may be mentioned.

  Examples of the acylphosphine described in JP-B-2-9596 include the following compounds.

  Further, thioxanthones described in JP-B-63-61950, coumarins described in JP-B-59-42864, and the like can also be mentioned.

(B) Onium salt compound Examples of the preferred (b) onium salt compound as the radical initiator used in the present invention include compounds represented by the following general formulas (1) to (3).

In formula (1), Ar ¹ and Ar ² each independently represent an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a carbon atom having 12 or less carbon atoms. An aryloxy group is mentioned. (Z ² ) ⁻ represents a counter ion selected from the group consisting of halogen ion, perchlorate ion, carboxylate ion, tetrafluoroborate ion, hexafluorophosphate ion, and sulfonate ion, preferably perchloric acid Ions, hexafluorophosphate ions, and aryl sulfonate ions.

In Formula (2), Ar ³ represents an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and 12 or less carbon atoms. Examples thereof include an alkylamino group, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, or a diarylamino group having 12 or less carbon atoms. (Z ³ ) ⁻ represents a counter ion having the same meaning as (Z ² ) ⁻ .

In formula (3), R ²³ , R ²⁴ and R ²⁵ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferable substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or an aryloxy group having 12 or less carbon atoms. (Z ⁴ ) ⁻ represents a counter ion having the same meaning as (Z ² ) ⁻ .

  Specific examples of onium salts that can be suitably used in the present invention include those described in paragraphs [0030] to [0033] of Japanese Patent Application No. 11-310623 previously proposed by the present applicant. And those described in paragraphs [0015] to [0046] of Japanese Patent Application No. 2000-160323, Japanese Patent Application No. 2000-266797, Japanese Patent Application No. 2001-177150, Japanese Patent Application No. 2000-160323, Specific aromatic sulfonium salt compounds described in Japanese Patent Application No. 2000-184603, Japanese Patent Application No. 2000-310808, Japanese Patent Application No. 2002-265467, and Japanese Patent Application No. 2002-366539 may be mentioned.

  The onium salt used in the present invention preferably has a maximum absorption wavelength of 400 nm or less, and more preferably 360 nm or less. By making the absorption wavelength in the ultraviolet region in this way, the lithographic printing plate precursor can be handled under white light.

(C) Organic peroxide Preferred as the radical initiator used in the present invention (c) The organic peroxide includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples include methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tertiarybutylperoxy) -3,3,5. -Trimethylcyclohexane, 1,1-bis (tertiarybutylperoxy) cyclohexane, 2,2-bis (tertiarybutylperoxy) butane, tertiarybutylhydroperoxide, cumene hydroperoxide, diisopropylbenzenehydride Loperoxide, parameter hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, ditertiary butyl peroxide, tertiary butyl Cumyl peroxide, dicumyl peroxide, bis (tertiarybutylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (tertiarybutylperoxy) hexane, 2,5-xanoyl peroxide, peroxy Succinic oxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, meta-toluoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate Nate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tertiary butyl peroxyacetate, tertiary butyl peroxypivalate, tertiary butyl peroxyneodecanoate, tarsha Tributyl peroxyoctanoate, tertiary butyl peroxy-3,5,5-trimethylhexanoate, tertiary butyl peroxylaurate, tertiary carbonate, 3,3'4,4'-tetra- (t -Butylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-hexylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (T-octylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (cumylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone Carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyldi (t-hexylperoxydihydrogen diphthalate), and the like.

  Among them, 3,3′4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3′4 4'-tetra- (t-hexylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-octylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (cumylper) Peroxyesters such as (oxycarbonyl) benzophenone, 3,3′4,4′-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, di-t-butyldiperoxyisophthalate are preferred.

(D) Thio compound The (d) thio compound preferable as the radical initiator used in the present invention includes a compound having a structure represented by the following general formula (4).

(Wherein R ²⁶ represents an alkyl group, an aryl group or a substituted aryl group, R ²⁷ represents a hydrogen atom or an alkyl group, and R ²⁶ and R ²⁷ are bonded to each other to form an oxygen, sulfur and nitrogen atom. (A group of nonmetallic atoms necessary to form a 5-membered to 7-membered ring which may contain a selected heteroatom.)
As an alkyl group in the said General formula (4), a C1-C4 thing is preferable. As the aryl group, those having 6 to 10 carbon atoms such as phenyl and naphthyl are preferable, and as the substituted aryl group, a halogen atom such as a chlorine atom and an alkyl such as a methyl group as described above. And those substituted with an alkoxy group such as a group, a methoxy group, and an ethoxy group. R ²⁷ is preferably an alkyl group having 1 to 4 carbon atoms. Specific examples of the thio compound represented by the general formula (4) include the following compounds.

(E) Hexaarylbiimidazole compounds (e) Hexaarylbiimidazole compounds preferred as the radical initiator used in the present invention include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2 , 2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-bromophenyl) -4,4 ′, 5,5′-tetra Phenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (m-methoxyphenyl) biimidazole, 2,2′-bis (o, o′-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2, 2′-bis (o-nitrophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5,5′-tetra Examples thereof include phenylbiimidazole and 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole.

(F) Ketooxime ester compound (f) The ketoxime ester compound preferable as the radical initiator used in the present invention includes 3-benzoyloxyiminobutane-2-one, 3-acetoxyiminobutane-2-one, 3 -Propionyloxyiminobutan-2-one, 2-acetoxyiminopentan-3-one, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, Examples include 3-p-toluenesulfonyloxyiminobutan-2-one and 2-ethoxycarbonyloxyimino-1-phenylpropan-1-one.

(G) Borate Compound Examples of the (g) borate compound preferable as the radical initiator used in the present invention include compounds represented by the following general formula (5).

(Wherein R ²⁸ , R ²⁹ , R ³⁰ and R ³¹ may be the same or different from each other, and each represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, A substituted or unsubstituted alkynyl group or a substituted or unsubstituted heterocyclic group, R ²⁸ , R ²⁹ , R ³⁰ and R ³¹ may be combined with each other to form a cyclic structure; (However, at least one of R ²⁸ , R ²⁹ , R ³⁰ and R ³¹ is a substituted or unsubstituted alkyl group. (Z ⁵ ) ⁺ represents an alkali metal cation or a quaternary ammonium cation.)
Examples of the alkyl group for R ^{28 to} R ³¹ include straight-chain, branched, and cyclic groups, and those having 1 to 18 carbon atoms are preferable. Specifically, methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, octyl, stearyl, cyclobutyl, cyclopentyl, cyclohexyl and the like are included. The substituted alkyl group includes an alkyl group as described above, a halogen atom (for example, —Cl, —Br, etc.), a cyano group, a nitro group, an aryl group (preferably a phenyl group), a hydroxy group, —COOR ³² (here R ³² represents a hydrogen atom, an alkyl group having 1 to 14 carbon atoms, or an aryl group), —OCOR ³³ or —OR ³⁴ (where R ³³ and R ³⁴ are alkyl groups having 1 to 14 carbon atoms, or aryl. And a group having a substituent represented by the following formula.

(Wherein R ³⁵ and R ³⁶ independently represent a hydrogen atom, an alkyl group having 1 to 14 carbon atoms, or an aryl group)
The aryl group of R ^{28 to} R ³¹ includes 1 to 3 ring aryl groups such as a phenyl group and a naphthyl group, and the substituted aryl group is a substitution of the above substituted alkyl group with the above aryl group. Those having a group or an alkyl group having 1 to 14 carbon atoms are included. Examples of the alkenyl group for R ^{28 to} R ³¹ include linear, branched and cyclic groups having 2 to 18 carbon atoms. Examples of the substituent of the substituted alkenyl group include those listed as the substituents of the substituted alkyl group. Examples of the alkynyl group of R ^{28 to} R ³¹ include straight chain or branched groups having 2 to 28 carbon atoms, and examples of the substituent of the substituted alkynyl group include those listed as the substituents of the substituted alkyl group. included. In addition, examples of the heterocyclic group of R ^{28 to} R ³¹ include a 5-membered ring or more, preferably a 5- to 7-membered heterocyclic group containing at least one of N, S, and O. May contain a condensed ring. Furthermore, you may have what was mentioned as a substituent of the above-mentioned substituted aryl group as a substituent. Specific examples of the compound represented by the general formula (5) are described in US Pat. Nos. 3,567,453 and 4,343,891, European Patents 109,772 and 109,773. Compounds and those shown below are mentioned.

(H) Azinium compounds Preferred (h) azinium salt compounds as radical initiators used in the present invention include JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, and JP-A-63-142346. Examples thereof include compounds having an N—O bond described in JP-A-63-143537 and JP-B-46-42363.

(I) Metallocene compounds (i) Metallocene compounds preferred as the radical initiator used in the present invention include those disclosed in JP-A Nos. 59-152396, 61-151197, 63-41484, and JP-A-2. No. -249, a titanocene compound described in JP-A-2-4705, and an iron-arene complex described in JP-A-1-304453 and JP-A-1-152109.

  Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3. 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- -2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) phenyl) titanium bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopentadi Enyl) bis [2,6-difluoro-3- (N-butylbialoyl-amino) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (N-butyl- (4-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3 -(N-benzyl-2,2-dimethylpentanoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (2-ethylhexyl) -4-tolyl-sulfonyl] ) Amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3-oxaheptyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2 , 6-Difluoro-3- (N- (3,6-dioxadecyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bi [2,6-difluoro-3- (trifluoromethylsulfonyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (trifluoroacetyl) phenyl] titanium,

Bis (cyclopentadienyl) bis [2,6-difluoro-3- (2-chlorobenzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (4-chloro Benzoyl) amino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (N- (3,6-dioxadecyl) -2,2-dimethylpentanoylamino) phenyl] titanium, bis (Cyclopentadienyl) bis [2,6-difluoro-3- (N- (3,7-dimethyl-7-methoxyoctyl) benzoylamino) phenyl] titanium, bis (cyclopentadienyl) bis [2,6 -Difluoro-3- (N-cyclohexylbenzoylamino) phenyl] titanium and the like.

(J) Active Ester Compound Preferred (j) active ester compounds as radical initiators used in the present invention include imide sulfonate compounds described in JP-B-62-2223, JP-B-63-14340, and JP-A-59-174831. Mention may be made of the active sulfonates described.

(K) Compound Having Carbon Halogen Bond Preferred examples of the compound (k) having a carbon halogen bond as the radical initiator used in the present invention include those represented by the following general formulas (6) to (12).

(Wherein, X ² represents a halogen atom, Y ¹ is _{^{-C (X 2) 3, -NH}} 2, -NHR 38, -NR 38, represent -OR ^38. Wherein R ³⁸ represents an alkyl group, a substituted An alkyl group, an aryl group, or a substituted aryl group, and R ³⁷ represents —C (X ² ) ₃ , an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a substituted alkenyl group.

(However, R ³⁹ is an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, a substituted aryl group, a halogen atom, an alkoxy group, a substituted alkoxyl group, a nitro group, or a cyano group, and X ³ is a halogen atom. And n is an integer of 1 to 3.)

(However, R ⁴⁰ is an aryl group or a substituted aryl group, R ⁴¹ is a group or halogen shown below, and Z ⁶ is —C (═O) —, —C (═S) — or —SO _2- , X ³ is a halogen atom, and m is 1 or 2.)

(R ⁴² and R ⁴³ are an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group or a substituted aryl group, and R ⁴⁴ is the same as R ³⁸ in the general formula (6).)

Wherein R ⁴⁵ is an optionally substituted aryl group or heterocyclic group, R ⁴⁶ is a trihaloalkyl group or trihaloalkenyl group having 1 to 3 carbon atoms, p is 1, 2 or 3.)

(Equation (10), .L ⁷ which represents a carbonylmethylene heterocyclic compound having a trihalogenomethyl group is a hydrogen atom or the ^{formula: CO- (R 47) q (} C (X 4) 3) at r substituent Q ² is a sulfur, selenium or oxygen atom, dialkylmethylene group, alkene-1,2-ylene group, 1,2-phenylene group or —N—R— group, and M ⁴ is a substituted or unsubstituted alkylene. Or an alkenylene group or a 1,2-arylene group, R ⁴⁸ is an alkyl group, an aralkyl group or an alkoxyalkyl group, and R ⁴⁷ is a carbocyclic or heterocyclic divalent aromatic group. And X ⁴ is a chlorine, bromine or iodine atom, q = 0 and r = 1, or q = 1 and r = 1 or 2.)

(Formula (11) represents a 4-halogeno-5- (halogenomethyl-phenyl) -oxazole derivative. X ⁵ is a halogen atom, t is an integer of 1 to 3, and s is an integer of 1 to 4. in and, R ⁴⁹ is a hydrogen atom or a CH _3-t X ⁵ _t group, R ⁵⁰ is s-valent optionally substituted unsaturated organic group.)

(Formula (12) represents a 2- (halogenomethyl-phenyl) -4-halogeno-oxazole derivative. X ⁶ is a halogen atom, v is an integer of 1 to 3, and u is an integer of 1 to 4. R ⁵¹ is a hydrogen atom or a CH _3-v X ⁶ _v group, and R ⁵² is an u-valent unsaturated organic group which may be substituted.)

  Specific examples of such a compound having a carbon-halogen bond include, for example, Wakabayashi et al., Bull. Chem. 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- Scan (trichloromethyl) -S- triazine. In addition, compounds described in British Patent 1388492, 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-trichloromethyl-S-triazine, etc. And compounds described in JP-A No. 53-133428, such as 2- (4-methoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxy-naphtho) 1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- [4- (2-ethoxyethyl) -naphth-1-yl] -4,6-bis-trichloro Til-S-triazine, 2- (4,7-dimethoxy-naphth-1-yl) -4,6-bis-trichloromethyl-S-triazine), 2- (acenaphtho-5-yl) -4,6- Examples include compounds described in German Patent No. 3333724, such as bis-trichloromethyl-S-triazine, and the like.

  F.F. C. J. Schaefer et al. Org. Chem. 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, etc. Can do. Furthermore, for example, the following compounds described in JP-A-62-258241 can be exemplified.

  Furthermore, for example, the following compounds described in JP-A-5-281728 can be mentioned.

  Or even more P. Hutt, E .; F. Elslager and L. M.M. The following compounds that can be easily synthesized by those skilled in the art according to the synthesis method described in “Journalof Heterocyclic Chemistry”, Volume 7 (No. 3) by Herbel, page 511 et seq. (1970) Examples of the group include the following compounds.

(L) Azo-based compound Preferred as a radical initiator used in the present invention (l) The azo-based compound includes 2,2′-azobisisobutyronitrile, 2,2′-azobispropionitrile, 1, 1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 4,4′-azobis (4-cyanovaleric acid), dimethyl 2,2′-azobisisobutyrate, 2,2′-azobis (2-methylpropionamide oxime) ), 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxy Echi ] Propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2 ′ -Azobis (N-cyclohexyl-2-methylpropionamide), 2,2'-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2'-azobis (2,4,4-trimethyl) Pentane) and the like.

  Still more preferred examples of the radical initiator in the present invention include the above-mentioned (a) aromatic ketones, (b) onium salt compounds, (c) organic peroxides, (e) hexaarylbiimidazole compounds, (i) ) Metallocene compounds, (k) compounds having a carbon halogen bond, and most preferred examples include aromatic iodonium salts, aromatic sulfonium salts, titanocene compounds, and trihalomethyls represented by general formula (6). -S-triazine compounds can be mentioned.

These radical initiators are 0.1 to 50% by mass, preferably 0.5 to 30% by mass, and particularly preferably 5 to 20% by mass with respect to the total solid content of the photosensitive layer. Can be added inside.
The radical initiator in the present invention is preferably used alone or in combination of two or more.

[(B) Radical polymerizable compound]
As the radically polymerizable compound contained in the photosensitive layer in the invention, a conventionally known polymerizable compound described below, that is, a compound having an ethylenically unsaturated bond capable of addition polymerization can be used.
Examples of conventionally known addition-polymerizable compounds having an ethylenically unsaturated bond include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and aliphatic polyvalent acids. Examples thereof include esters with polyhydric alcohol compounds, amides of the above unsaturated carboxylic acids and aliphatic polyvalent amine compounds, and the like.

Specific examples of the ester monomer of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include the following.
Acrylic esters include ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylol Methylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetra Acrylate, dipentaerythritol diacrylate, Dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

  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- (acryloxyethoxy) phenyl] dimethylmethane. 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. Furthermore, the mixture of the above-mentioned ester monomer can also be mentioned.

  Specific examples of an amide monomer of an aliphatic polyvalent amine compound and an unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexa. Examples include methylene bis-methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, and xylylene bismethacrylamide.

Other examples include vinyls containing a hydroxyl group represented by the following general formula (A) in a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708. Examples thereof include a vinylurethane compound containing two or more polymerizable vinyl groups in one molecule to which a monomer is added.
_{CH 2 = C (R) COOCH} 2 CH (R ') OH (A)
(However, R and R ′ represent H or CH _3. )

  Further, urethane acrylates as described in JP-A-51-37193, JP-A-48-64183, JP-B-49-43191, JP-B-52-30490 are disclosed. Polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid can be used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984) as photocurable monomers and oligomers can also be used.

  Further, as another preferred example of the polymerizable compound, it has two or more phenyl groups substituted with vinyl groups in the molecule represented by the following general formulas described on pages 13 to 14 of JP-A-2001-290271. A polyfunctional styrene crosslinking agent is mentioned. When such a polyfunctional styrene crosslinking agent is used, crosslinking can be effectively carried out by recombination of styryl radicals generated by radicals generated from the radical initiator, and higher sensitivity can be realized.

In the above general formula, Z ² represents a linking group, and R ²¹ , R ²² and R ²³ are a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, An aryl group, an alkoxy group, an aryloxy group, and the like, and these groups may be substituted with an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, a hydroxy group, or the like. R ²⁴ represents a substitutable group or atom. m ² represents an integer of 0 to 4, and k ² represents an integer of 2 or more.

Here, as the linking group represented by Z ² , —O—, —S—, an alkylene group, an alkenylene group, an arylene group, —N (R ⁵ ) —, —C═ (O) —O—, — Examples include C (R ⁶ ) ═N—, —C═ (O) —, a sulfonyl group, a heterocyclic group, and the like, and a linking group formed by combining two or more of these. Here, R ⁵ and R ⁶ represent a hydrogen atom, an alkyl group, an aryl group, or the like. These linking groups may further have a substituent such as an alkyl group, an aryl group, or a halogen atom.

When the linking group represented by Z ² includes a heterocyclic group, the heterocyclic group includes a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, a tetrazole ring, an isoxazole ring, an oxazole ring, an oxadiazole ring, Isothiazole ring, thiazole ring, thiadiazole ring, thiatriazole ring, indole ring, indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring , Pyrimidine ring, pyrazine ring, triazine ring, quinoline ring, quinoxaline ring and other nitrogen-containing heterocycles, furan ring, thiophene ring and the like, and these may further have a substituent as described above.

Particularly preferred polyfunctional styrene crosslinking agents represented by the above general formula are those in which R ²¹ and R ²² are hydrogen atoms, and R ²³ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (methyl group, ethyl group, etc. And a compound in which m is 2 to 10 is preferable. Although the specific example [(C-1)-(C-11)] of the polyfunctional styrene crosslinking agent represented with the said general formula is shown below, it is not limited to these.

  In the present invention, these monomers can be used in a chemical form such as a prepolymer, that is, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof.

  Among the polymerizable compounds described above, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds and amides of unsaturated carboxylic acids and aliphatic polyvalent amine compounds are preferred, and unsaturated carboxylic acids and aliphatic polyhydric compounds are preferred. Esters with a monohydric alcohol compound are most preferred from the viewpoints of developability and printing durability when applied to the photosensitive layer of the image forming material.

  The amount of the polymerizable compound used is preferably 5 to 90% by mass, more preferably, based on the total solid content of the photosensitive layer, from the viewpoint of film formability, printing durability and storage stability. It is 10-80 mass%, More preferably, it is 20-75 mass%.

[(C) Sensitizing dye]
The photosensitive layer according to the present invention preferably further contains a sensitizing dye from the viewpoint of improving sensitivity. The sensitizing dye is used for the purpose of improving the exposure sensitivity according to the absorption wavelength. For this reason, a dye suitable for the exposure wavelength may be selected according to the image forming mechanism. As the sensitizing dye, (1) those having absorption in the 350 nm to 450 nm region, (2) those having absorption in the infrared region, and the like are appropriately used. By exposure at a wavelength that can be absorbed by the sensitizing dye, the radical generation reaction of the above-described (A) radical initiator and the polymerization reaction of the (B) radical polymerizable compound thereby are promoted.

(1) Sensitizing dye having absorption in the region of 350 to 450 nm Examples of such a sensitizing dye include compounds represented by the following general formulas (XIV) to (XVIII).

(In the formula (XIV), A ¹ represents a sulfur atom or NR ⁵⁰ , R ⁵⁰ represents an alkyl group or an aryl group, and L ² represents the basic nucleus of the dye in combination with the adjacent A ¹ and the adjacent carbon atom. Represents a nonmetallic atomic group to be formed, R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁵¹ and R ⁵² are bonded to each other to form an acidic nucleus of the dye. W represents an oxygen atom or a sulfur atom.)

  Preferred specific examples of the compound represented by the general formula (XIV) are shown below.

(In the formula (XV), Ar ¹ and Ar ² each independently represent an aryl group, and are linked via a bond with —L ³ —, where L ³ represents —O— or —S—. W is synonymous with that shown in the general formula (XIV).)

  Preferable examples of the compound represented by the general formula (XV) include the following.

(In the formula (XVI), A ² represents a sulfur atom or NR ⁵⁹ , L ⁴ represents a nonmetallic atomic group that forms a basic nucleus of the dye in combination with adjacent A ² and a carbon atom, R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ and R ⁵⁸ each independently represent a monovalent nonmetallic atomic group, and R ⁵⁹ represents an alkyl group or an aryl group.)

  Preferable examples of the compound represented by the general formula (XVI) include the following.

(In the formula (XVII), A ³ and A ⁴ each independently represent —S— or —NR ⁶³ — or —NR ⁶⁴ —, and R ⁶³ and R ⁶⁴ each independently represents a substituted or unsubstituted alkyl group, substituted Alternatively, it represents an unsubstituted aryl group, and L ⁵ and L ⁶ each independently represents a nonmetallic atomic group that forms a basic nucleus of a dye in combination with adjacent A ³ , A ⁴ and adjacent carbon atoms. , R ⁶¹ and R ⁶² are each independently a monovalent non-metallic atomic group or can be bonded to each other to form an aliphatic or aromatic ring.

  Preferable examples of the compound represented by the general formula (XVII) include the following.

(In the formula (XVIII), R ⁶⁶ represents an aromatic ring or a hetero ring which may have a substituent, and A ⁵ represents an oxygen atom, a sulfur atom or —NR ⁶⁷ —. R ⁶⁴ , R ⁶⁵ and R ⁶⁷ each independently represents a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ may be bonded to each other to form an aliphatic or aromatic ring. it can.)

  Preferable specific examples of the compound represented by the general formula (XVIII) include those shown below.

  These sensitizing dyes can be subjected to various chemical modifications for improving the characteristics of the photosensitive layer. For example, by combining a sensitizing dye and an addition polymerizable compound structure (for example, an acryloyl group or a methacryloyl group) by a method such as a covalent bond, an ionic bond, or a hydrogen bond, the exposure film can be increased in strength or exposed. Unnecessary precipitation suppression of the dye from the subsequent film can be performed.

Furthermore, for the purpose of enhancing the processability of the photosensitive layer to an (alkaline) aqueous developer, the hydrophilic portion (carboxyl group and its ester, sulfonic acid group and its ester, ethylene oxide) is used for these sensitizing dyes. It is effective to introduce an acid group or polar group). In particular, ester-type hydrophilic groups have a relatively hydrophobic structure in the photosensitive layer, so that they have excellent compatibility. In the developer, acid groups are generated by hydrolysis and hydrophilicity is increased. Has characteristics.
In addition, for example, a substituent can be appropriately introduced into the sensitizing dye in order to improve compatibility in the photosensitive layer and suppress crystallization. For example, in certain types of photosensitive systems, unsaturated bonds such as aryl groups and allyl groups may be very effective in improving compatibility. By introducing an obstacle, crystal precipitation can be remarkably suppressed.
Moreover, the adhesiveness to inorganic substances, such as a metal and a metal oxide, can be improved by introduce | transducing a phosphonic acid group, an epoxy group, a trialkoxysilyl group, etc. with respect to a sensitizing dye. In addition, a method such as polymerization of a sensitizing dye can be used depending on the purpose.

Details of the usage such as which structure of these sensitizing dyes are used, whether they are used alone or in combination of two or more, and how much is added, can be appropriately set according to the performance design of the final photosensitive material. . For example, the compatibility with the photosensitive composition layer can be enhanced by using two or more sensitizing dyes in combination. In selecting the sensitizing dye, in addition to the photosensitivity, the molar extinction coefficient at the emission wavelength of the light source used is an important factor. By using a dye having a large molar extinction coefficient, the amount of the dye added can be made relatively small, which is economical and advantageous from the viewpoint of film physical properties of the photosensitive layer when used for a lithographic printing plate precursor. It is. The photosensitivity of the photosensitive layer, the resolution, and the physical properties of the exposed film are greatly affected by the absorbance at the light source wavelength. Therefore, the addition amount of the sensitizing dye is appropriately selected in consideration of these factors. For example, the sensitivity decreases in a low region where the absorbance is 0.1 or less. Also, the resolution becomes low due to the influence of halation.

  However, for the purpose of curing a thick film of, for example, 5 μm or more, there are cases where such a low absorbance can be increased instead. Further, in a region where the absorbance is as high as 3 or more, most of the light is absorbed on the surface of the photosensitive layer, and the internal curing is inhibited. For example, when used as a printing plate, the film strength, the substrate adhesion Will be insufficient. When used as a lithographic printing plate used in a relatively thin film thickness, (1) the addition amount of the sensitizing dye having absorption in the region of 350 to 450 nm is such that the absorbance of the photosensitive layer is 0.1 to 1.5. Is preferably set to be in the range of 0.25 to 1. When used as a lithographic printing plate precursor, this is usually 0.05-30 parts by weight, preferably 0.1-20 parts by weight, more preferably 0.2-0.2 parts by weight per 100 parts by weight of the photosensitive layer component. The range is 10 parts by mass.

(2) Sensitizing dye having absorption in the infrared region In the present invention, as a sensitizing dye having absorption in the infrared region (specifically, a wavelength of about 680 nm to 1200 nm), infrared light is absorbed and thermal energy is absorbed. It is preferable to contain an infrared absorbing agent that converts it into the following. Examples of such an infrared absorber include a known spectral sensitizing dye, or a dye or pigment that absorbs light and interacts with a photo radical initiator. By using such (2) sensitizing dye, the photosensitive layer of the present invention has infrared sensitivity.

<Spectral sensitizing dye or dye>
Spectral sensitizing dyes or dyes preferred as infrared absorbers used in the present invention are polynuclear aromatics (for example, pyrene, perylene, triphenylene), xanthenes (for example, fluorescein, eosin, erythrosine, rhodamine B, rose bengal). ), Cyanines (eg, thiacarbocyanine, oxacarbocyanine), merocyanines (eg, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin) , Acriflavine), phthalocyanines (eg, phthalocyanine, metal phthalocyanine), porphyrins (eg, tetraphenylporphyrin, central metal-substituted porphyrin), chlorophylls (eg, chlorophyll) Le, chlorophyllin, center metal-substituted chlorophyll), metal complexes (for example, the following compound), anthraquinones (e.g., anthraquinone), squaryliums (e.g., squarylium), and the like.

More preferable spectral sensitizing dyes or dyes include compounds described in the following publications.
The pyrylium salts described in Japanese Patent Publication No. 40-28499, for example, the following compounds may be mentioned.

  Examples of the cyanines described in JP-B No. 46-42363 include the following compounds.

  Examples of the benzofuran dye described in JP-A-2-63053 include the following compounds.

  Examples of the conjugated ketone dyes disclosed in JP-A-2-85858 and JP-A-2-216154 include the following compounds.

  Examples thereof include dyes described in JP-A 57-10605 and azocinnamylidene derivatives described in JP-B-2-30321, such as the following compounds.

  Examples of the cyanine dyes described in JP-A-1-287105 include the following compounds.

  Examples of the xanthene dyes described in JP-A Nos. 62-31844, 62-31848, and 62-143043 include the following compounds.

  Aminostyryl ketone described in JP-B-59-28325, for example, the following compounds may be mentioned.

  Further, in particular, the following infrared absorbing dyes or pigments are also preferably used as the sensitizing dye. Preferred examples of the dye include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, and the like. Examples include cyanine dyes described in Japanese Patent No. 434,875.

  In addition, as cyanine dyes that can be suitably used in the present invention, paragraph numbers [0017] to [0019] of JP-A No. 2001-133969, paragraph numbers [0012] to [0038] of JP-A No. 2002-40638, Those described in paragraph numbers [0012] to [0023] of JP-A-2002-23360 can be mentioned. Specific examples include those exemplified below.

  Further, as a sensitizing dye, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and further described in US Pat. No. 3,881,924. Substituted arylbenzo (thio) pyrylium salts, trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, and JP-A-58 -22043, 59-41363, 59-84248, 59-84249, 59-146063, 59-146061, and pyrium compounds described in JP-A-59-216146. The cyanine dyes described above, the pentamethine thiopyrylium salt described in US Pat. No. 4,283,475, and the like, and Japanese Patent Publication Nos. 5-13514 and 5-19702 Pyrylium compounds described in distribution is also preferably used.

  In addition, near infrared absorbing dyes described as formulas (I) and (II) in US Pat. No. 4,756,993 and phthalocyanine dyes described in EP 916513A2 are also preferable dyes. Can do.

  Furthermore, the anionic infrared absorber described in Japanese Patent Application No. 10-79912 can also be suitably used. An anionic infrared absorbing agent refers to an anionic infrared absorbing agent having an anionic structure without a cationic structure in the mother nucleus of a dye that substantially absorbs infrared rays. For example, (b) anionic metal complex, (b) anionic carbon black, (c) anionic phthalocyanine, and (d) a compound represented by the following general formula (i). The counter cation of these anionic infrared absorbers is a monovalent cation containing a proton or a polyvalent cation.

  Here, (a) an anionic metal complex refers to an anion formed by the central metal of the complex part that substantially absorbs light and the entire ligand.

  (B) Examples of the anionic carbon black include carbon black to which anionic groups such as sulfonic acid, carboxylic acid, and phosphonic acid groups are bonded as substituents. In order to introduce these groups into carbon black, as described in Carbon Black Handbook 3rd Edition (Edited by Carbon Black Association, April 5, 1995, published by Carbon Black Association), page 12, What is necessary is just to take means, such as oxidizing carbon black.

  (C) Anionic phthalocyanine refers to a phthalocyanine skeleton having the anion group previously mentioned in the description of (b) as a substituent bonded to form an anion as a whole.

Next, (d) the compound represented by the general formula (i) will be described in detail. In the general formula (i), G ⁹ represents an anionic substituent, and G ¹⁰ represents a neutral substituent. (X ¹⁰ ) ⁺ represents a 1 to m-valent cation containing a proton, and m represents an integer of 1 to 6. M ⁵ represents a conjugated chain, and this conjugated chain M ⁵ may have a substituent or a ring structure. The conjugated chain M ⁵ can be represented by the following formula.

In the formula, R ⁸⁰ , R ⁸¹ and R ⁸² are each independently a hydrogen atom, halogen atom, cyano group, alkyl group, aryl group, alkenyl group, alkynyl group, carbonyl group, thio group, sulfonyl group, sulfinyl group, oxy A group and an amino group, which may be linked to each other to form a ring structure. n represents an integer of 1 to 8.

  Of the anionic infrared absorbers represented by the general formula (i), those of the following IRA-1 to IRA-5 are preferably used.

  Moreover, the cationic infrared absorber shown to the following IRC-1-IRC-44 can also be used preferably.

In the structural formula, T ⁻ represents a monovalent counter anion, preferably a halogen anion (F—, Cl—, Br—, I—), a Lewis acid anion (BF ₄ —, PF ₆ —, SbCl _6). -, ClO ₄ -), alkyl sulfonate anion, an arylsulfonate anion.

  The alkyl of the alkyl sulfonic acid means a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, a butyl group. , Pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s-butyl, t- A butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group, and 2-norbornyl group 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.

  The aryl of the aryl sulfonic acid includes one consisting of one benzene ring, two or three benzene rings forming a condensed ring, and benzene ring and five-membered unsaturated ring forming a condensed ring. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group, and among these, a phenyl group and a naphthyl group are more preferable.

  Moreover, the nonionic infrared absorber shown to the following IRN-1-IRN-9 can also be used preferably.

  Among the exemplified compounds, IRA-1 is a particularly preferred anionic infrared absorber, and IRC-7, IRC-30, IRC-40, and IRC-42 are nonionic infrared absorbers as cationic infrared absorbers. As IRN-9.

<Pigment>
Examples of infrared absorbing pigments used in the present invention include commercially available pigments and color index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, published in 1977), “Latest Pigment Application Technology” (CMC). Publication, 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 , Quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like. 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” (Yokoshobo), “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 μm to 10 μm, preferably in the range of 0.05 μm to 1 μm, from the viewpoint of the stability of the dispersion in the photosensitive layer coating solution and the uniformity of the photosensitive layer. More preferably, the thickness is preferably in the range of 0.1 μm to 1 μm.

  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).

The sensitizing dye added to accelerate the polymerization reaction (curing reaction) may be directly added together with other components in the photosensitive layer. However, another layer adjacent to the sensitizing dye may be provided to the photosensitive layer. Even if it is added, the same effect can be obtained.
In particular, when the photosensitive layer in the present invention is used as a material for a negative photosensitive layer of a lithographic printing plate precursor described later, it may be added to the same layer as the photosensitive layer, or another layer is provided and added thereto. However, when a negative lithographic printing plate precursor is prepared, the optical density at the absorption maximum in the wavelength range of 300 nm to 1200 nm of the photosensitive layer is between 0.1 and 3.0. It is preferable from the viewpoint of sensitivity. Since the optical density is determined by the addition amount of the sensitizing dye and the thickness of the photosensitive layer, the predetermined optical density can be obtained by controlling both conditions. The optical density of the photosensitive layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a photosensitive layer having a thickness appropriately determined in a range where the coating amount after drying is necessary as a lithographic printing plate is formed, and a transmission type optical densitometer is used. Examples thereof include a method of measuring, a method of forming a photosensitive layer on a reflective support such as aluminum, and measuring a reflection density.
The addition amount of the sensitizing dye having absorption in the infrared region to the photosensitive layer is preferably about 0.5 to 20% by mass, and more preferably 2 to 10% by mass.

[(D) Binder polymer]
A binder polymer is preferably used for improving the film properties of the photosensitive layer and other purposes.
From the viewpoint of sensitivity, the binder polymer is preferably a compound having an ethylenically unsaturated bond represented by the following general formulas (a) to (c) in the side chain. Among these, from the viewpoint of sensitivity and storage stability, a compound having an ethylenically unsaturated bond represented by the following general formula (1) is most preferable.

In the general formulas (a) to (c), R ^{1 to} R ¹¹ each independently represents a monovalent organic group. X and Y each independently represent an oxygen atom, a sulfur atom, or —N—R ¹² . Z represents an oxygen atom, a sulfur atom, —N—R ¹² or a phenylene group. R ¹² represents a hydrogen atom or a monovalent organic group.

In the general formula (a), R ^{1 to} R ³ each independently represents a monovalent organic group, and R ¹ is preferably a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom and a methyl group are preferable because of high radical reactivity. R ² and R ³ are each independently a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an optionally substituted alkyl group, or a substituted group. An aryl group 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 may be mentioned. 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 —NR ¹² —, and R ¹² represents a hydrogen atom or a monovalent organic group. Here, examples of R ¹² include an alkyl group which may have a substituent. Among them, a hydrogen atom, a methyl group, an ethyl group, and an isopropyl group are preferable 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 represents a monovalent organic group, and R ^{4 to} R ⁸ are, for example, a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, Carboxyl group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, alkyl group which may have a substituent, aryl group which may have a substituent, alkoxy group which may have a substituent, substituted An aryloxy group which may have a group, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, a substituent Examples thereof include an arylsulfonyl group which may have 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. Here, as a substituent which can be introduce | transduced, what was mentioned in general formula (a) is illustrated.
Y represents an oxygen atom, a sulfur atom, or —N—R ¹² . Examples of R ¹² include the same as those in the general formula (1).

In the general formula (c), R ^{9 to} R ¹¹ each independently represents a monovalent organic group, and R ⁹ is preferably a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom and a methyl group are preferable because of high radical reactivity. R ¹⁰ and R ¹¹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or an alkyl group which may have a substituent. An aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, a substituent An arylamino group which may have, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like are mentioned. 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 because of high radical reactivity. Here, examples of the substituent that can be introduced include those listed in the general formula (a).
Z represents an oxygen atom, a sulfur atom, —NR ¹² —, or a phenylene group which may have a substituent. Examples of R ¹² include an alkyl group which may have a substituent. Among them, a hydrogen atom, a methyl group, an ethyl group, and an isopropyl group are preferable because of high radical reactivity.

  In addition, as the binder polymer in the present invention, those having a carboxyl group in the side chain are preferable from the viewpoint of excellent development removability of the non-image area, and among them, excellent developability and adhesion to the protective layer of the present invention. Therefore, a side chain carboxyl group-containing polymer represented by the following general formula (d) is preferable. Hereinafter, the side chain carboxyl group-containing polymer will be described in detail.

In General Formula (d), R ¹ represents a hydrogen atom or a methyl group, and R ² includes two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And represents a linking group having 2 to 82 atoms. A represents an oxygen atom or —NR ³ —, and R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. n represents an integer of 1 to 5.
First, R ¹ in the general formula (d) represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable.

The linking group represented by R ² in the general formula (d) includes two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. Is from 2 to 82, preferably from 2 to 50, and more preferably from 2 to 30. The number of atoms shown here refers to the number of atoms including the substituent when the linking group has a substituent.
More specifically, the number of atoms constituting the main skeleton of the linking group represented by R ² is preferably 1-30, more preferably 3-25, and 4-20. More preferred is 5-10. The “main skeleton of the linking group” in the present invention refers to an atom or an atomic group used only for linking A and the terminal COOH in the general formula (d), and particularly when there are a plurality of linking paths. Refers to an atom or atomic group that constitutes a path with the least number of atoms used. Therefore, when a linking group has a ring structure, the number of atoms to be included differs depending on the linking site (for example, o-, m-, p-, etc.).

More specifically, examples of the linking group represented by R ² in the general formula (d) include alkylene, substituted alkylene, arylene, substituted arylene, and the like, and these divalent groups include a plurality of amide bonds or ester bonds. You may have the structure connected.
Examples of the linking group having a chain structure include ethylene and propylene. A structure in which these alkylenes are linked via an ester bond can also be exemplified as a preferable example.

Among these, the linking group represented by R ² in the general formula (d) is preferably an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure having 3 to 30 carbon atoms. More specifically, a compound having an aliphatic cyclic structure such as cyclopropane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, dicyclohexyl, tercyclohexyl, norbornane and the like, which may be substituted by one or more arbitrary substituents And (n + 1) valent hydrocarbon groups by removing (n + 1) hydrogen atoms on an arbitrary carbon atom constituting. R ² preferably has 3 to 30 carbon atoms including a substituent.

One or more arbitrary carbon atoms of the compound constituting the aliphatic cyclic structure may be replaced with a heteroatom selected from a nitrogen atom, an oxygen atom, or a sulfur atom. In terms of printing durability, R ² is a condensed polycyclic aliphatic hydrocarbon, a bridged cyclic aliphatic hydrocarbon, a spiro aliphatic hydrocarbon, an aliphatic hydrocarbon ring assembly (a plurality of rings are connected by a bond or a linking group). And (n + 1) valent hydrocarbon group having an aliphatic cyclic structure which may have a substituent having 5 to 30 carbon atoms and containing two or more rings. preferable. Also in this case, the carbon number includes the carbon atom of the substituent.

Most preferably, the linking group represented by R ² is one having 5 to 10 atoms constituting the main skeleton of the linking group, and is structurally a chain structure having an ester bond in the structure. And those having a cyclic structure as described above are preferred.

Examples of the substituent that can be introduced into the linking group represented by R ² include monovalent nonmetallic atomic groups other than hydrogen, such as halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups. Group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N- Diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy , Arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-aryl Ureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N ′ -Alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N ' -Aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N'-al Kill-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base 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 An arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugated base 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, N-acylsulfamoyl group and its conjugate base group, N- alkylsulfonylsulfamoyl group (-SO ₂ NHSO ₂ alkyl)) and its conjugated base group, N- aryl sulfonylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and its conjugate Base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl group (—Si (Oaryl) ₃ ), hydroxysilyl Group (—Si (OH) ₃ ) and its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (— PO ₃ (aryl) _2), alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )) , Monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group, monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) And its conjugate base group, dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) ( aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group, monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group, cyano group, nitro group, group, ₍₂ -B (alkyl)) dialkyl boryl group, Jiariruboriru group (-B (aryl) _2), alkyl aryl boryl -B (alkyl) (aryl)) , dihydroxy boryl group (-B (OH) ₂₎ and its conjugated base group, an alkyl hydroxy boryl group (-B (alkyl) (OH) ) and its conjugated base group, an aryl hydroxy boryl And the group (—B (aryl) (OH)) and its conjugate base group, aryl group, alkenyl group and alkynyl group.

  Although depending on the design of the photosensitive layer, a substituent having a hydrogen atom capable of hydrogen bonding, particularly a substituent having an acid dissociation constant (pKa) smaller than that of carboxylic acid tends to lower the printing durability. Therefore, it is not preferable. On the other hand, hydrophobic substituents such as halogen atoms, hydrocarbon groups (alkyl groups, aryl groups, alkenyl groups, alkynyl groups), alkoxy groups, aryloxy groups and the like are more preferable because they tend to improve printing durability. When the cyclic structure is a monocyclic aliphatic hydrocarbon having 6 or less members such as cyclopentane or cyclohexane, it preferably has such a hydrophobic substituent. If possible, these substituents may be bonded to each other or with a substituted hydrocarbon group to form a ring, and the substituent may be further substituted.

R ³ in the case where A in the general formula (d) is NR ³ — represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ³ include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.
Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, isobutyl group, sec-butyl group, 1 carbon number such as tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group Up to 10 linear, branched or cyclic alkyl groups.
Specific examples of the aryl group include carbon having one heteroatom selected from the group consisting of an aryl group having 1 to 10 carbon atoms such as a phenyl group, a naphthyl group, and an indenyl group, a nitrogen atom, an oxygen atom, and a sulfur atom. Examples include heteroaryl groups of 1 to 10, such as furyl, thienyl, pyrrolyl, pyridyl, and quinolyl groups.
Specific examples of the alkenyl group include those having 1 to 10 carbon atoms such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group, 1-cyclohexenyl group and the like. A linear, branched, or cyclic alkenyl group is mentioned.
Specific examples of the alkynyl group include alkynyl groups having 1 to 10 carbon atoms such as ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group. The substituent that R ³ may have is the same as those exemplified as the substituent that R ² can introduce. However, the carbon number of R < ³ > is 1-10 including the carbon number of a substituent.

A in the general formula (d) is preferably an oxygen atom or —NH— because synthesis is easy.
Further, n in the general formula (d) represents an integer of 1 to 5, and is preferably 1 in terms of printing durability.

  Furthermore, as the binder polymer of the present invention, those having an amide group in the side chain are preferred from the viewpoint of excellent developability, storage stability, and adhesiveness to the protective layer. A polymer having an amide group represented by e) is more preferable.

In general formula (e), Z represents —CO— or —SO ₂ —, and R represents a hydrogen atom or a monovalent organic group. Z is particularly preferably —CO—, and R is preferably a hydrogen atom, an alkyl group which may have a substituent, an aryl group, an alicyclic group, or a heterocyclic group.

  Moreover, a linear organic polymer can also be used as a binder polymer in this invention. As such a “linear organic polymer”, a known one can be arbitrarily used. Preferably, a linear organic polymer that is soluble or swellable in water or weak alkaline water is selected in order to enable water development or weak alkaline water development. The linear organic polymer is selected and used not only as a film-forming agent for the photosensitive layer but also according to its use as water, weak alkaline water or an organic solvent developer. For example, when a water-soluble organic polymer is used, water development becomes possible. Examples of such linear organic polymers include radical polymers having a carboxylic acid group in the side chain, such as JP-A-59-44615, JP-B-54-34327, JP-B-58-12777, and JP-B-54-25957. Disclosed in JP-A-54-92723, JP-A-59-53836, and JP-A-59-71048, that is, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer. Examples thereof include a polymer, a crotonic acid copolymer, a maleic acid copolymer, and a 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 a polymer having a hydroxyl group are useful.

  Among these, in particular, (meth) acrylic resins having a benzyl group or an allyl group and a carboxyl group in the side chain, and Japanese Patent Application Laid-Open Nos. 2000-187322, 2002-62648, 2001-253217, and Japanese Patent Application Alkali-soluble resins having a double bond in the side chain described in JP-A-2002-287920, JP-A-2002-62648 and the like are excellent in balance of film strength, sensitivity, and developability, and are preferable.

  In addition, Japanese Patent Publication No. 7-2004, Japanese Patent Publication No. 7-120041, Japanese Patent Publication No. 7-120042, Japanese Patent Publication No. 8-12424, Japanese Patent Laid-Open No. 63-287944, Japanese Patent Laid-Open No. 63-287947, Japanese Patent Laid-Open No. Urethane-based binder polymers containing acid groups described in Japanese Patent No. 271741 and Japanese Patent Application No. 10-116232 are very excellent in strength, and are advantageous in terms of printing durability and suitability for low exposure.

  In addition, polyvinyl pyrrolidone, polyethylene oxide, and the like are useful as the water-soluble linear organic polymer. 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.

  The glass transition point (Tg) of such a binder polymer is preferably in the range of 60 to 300 ° C, more preferably 80 to 250 ° C, and most preferably 90 to 200 ° C, from the viewpoint of storage stability and sensitivity.

The weight average molecular weight of the binder polymer used in the present invention is preferably 5000 or more, more preferably in the range of 10,000 to 300,000, and the number average molecular weight is preferably 1000 or more, more preferably 2000. It is in the range of ~ 250,000. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1 or more, and more preferably 1.1 to 10.
These binder polymers may be random polymers, block polymers, graft polymers or the like, but are preferably random polymers.

The binder polymer used in the present invention can be synthesized by a conventionally known method. Solvents used in the synthesis include, for example, tetrahydrofuran, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 1-methoxy. Examples include 2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, and water. These solvents are used alone or in combination of two or more.
As the radical polymerization initiator used for synthesizing the polymer used in the present invention, known compounds such as azo initiators and peroxide initiators can be used.

  The binder polymer used in the present invention may be used alone or in combination. The amount of these binder polymers added to the photosensitive layer in the present invention is 20 to 95% by mass, preferably 30 to 90% by mass, based on the total solid content. When the addition amount is less than 20% by mass, the effect of improving the strength of the image portion cannot be sufficiently obtained when an image is formed. If the amount added exceeds 95% by mass, no image is formed. Moreover, it is preferable that the content ratio of the (B) radically polymerizable compound and the binder polymer is in the range of 1/9 to 7/3 by mass ratio.

[Other ingredients]
As long as the effects of the present invention are not impaired, known additives can be used in combination for various purposes in the photosensitive layer according to the present invention.
In the photosensitive layer of the present invention, a dye having a large absorption in the visible light region can be used as an image colorant. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in No. 293247. In addition, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can also 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 added amount is 0.01 to 10% by mass with respect to the total solid content of the photosensitive layer coating solution.

In the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the radical polymerizable compound during preparation or storage of the photosensitive layer coating solution. Suitable thermal polymerization inhibitors 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 and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the entire composition.
If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition due to oxygen, and it may be unevenly distributed on the surface of the photosensitive layer in the course of drying after coating. . The amount of the higher fatty acid derivative added is preferably about 0.1% by mass to about 10% by mass of the total composition.

<Method for producing image forming material>
The image forming material of the present invention is characterized by having the above-described photosensitive layer and protective layer in this order on a support. Hereinafter, the image forming material of the present invention will be described in detail with reference to a planographic printing plate precursor which is a preferred embodiment.
The lithographic printing plate precursor as the image forming material of the present invention can be produced by preparing the photosensitive layer coating solution by dissolving the constituent components of the photosensitive layer in a solvent and coating the solution on a suitable support. .

  Solvents used in the photosensitive layer coating solution include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2- Examples include propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, toluene, water, etc. However, the present invention is not limited to this. These solvents are used alone or in combination. The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by mass.

In addition, the coating amount (solid content) of the photosensitive layer on the support obtained after coating and drying varies depending on the use, but the lithographic printing plate precursor is generally 0.5% from the viewpoint of sensitivity and film properties. -5.0 g / m < ² > is preferable.
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

  In addition, the photosensitive layer coating solution has a nonionic interface as described in JP-A Nos. 62-251740 and 3-208514 in order to increase the processing stability of the photosensitive layer with respect to development conditions. Activators, amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149, and fluorine-based surfactants as described in JP-A-62-170950 are added. can do.

  Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like.

  Specific examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N, N- Examples include betaine type (for example, trade name Amorgen K, manufactured by Dai-ichi Kogyo Co., Ltd.).

  The proportion of each surfactant in the photosensitive layer coating solution is preferably 0.05 to 15% by mass, more preferably 0.1 to 5% by mass.

  Furthermore, in the photosensitive layer coating solution according to the present invention, a plasticizer is added as needed to impart flexibility of the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.

(Support)
The support of the lithographic printing plate precursor is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, paper laminated with plastic (for example, polyethylene, polypropylene, polystyrene, etc.), metal plate (For example, aluminum, zinc, copper, etc.), plastic film (for example, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl Acetal, etc.). These may be a single component sheet such as a resin film or a metal plate, or may be a laminate of two or more materials. For example, a paper or plastic film on which a metal as described above is laminated or vapor-deposited. And laminated sheets of different plastic films.

As the support, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of different elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. 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 at most 10% by mass. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used.
The aluminum plate has a thickness of about 0.1 to 0.6 mm, preferably 0.15 to 0.4 mm, and particularly preferably 0.2 to 0.3 mm.

Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution 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, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, 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. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.

  The roughened aluminum plate can be subjected to an anodizing treatment for enhancing the water retention and wear resistance of the surface through an alkali etching treatment and a neutralization treatment, if desired. As an electrolyte used for anodizing treatment of an aluminum plate, various electrolytes that form a porous oxide film can be used. In general, 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 electrolyte.

The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. However, in general, the electrolyte concentration is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. dm ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are suitable.
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, or the non-image part of the lithographic printing plate is easily scratched, so that the ink adheres to the scratched part during printing. “Scratches and dirt” are likely to occur.
Such anodizing treatment is applied to the surface used for printing the support of the lithographic printing plate, but an anodized film of 0.01 to 3 g / m ² is also formed on the back surface due to the back of the lines of electric force. It is common to form.

The hydrophilic treatment of the support surface is performed after the anodizing treatment, and conventionally known treatment methods are used. Such hydrophilization treatment is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are various alkali metal silicate methods (for example, sodium silicate aqueous solution). In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, disclosed in Japanese Patent Publication No. 36-22063 is potassium fluoride zirconate and U.S. Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid as described above is used.
Among these, a particularly preferred hydrophilic treatment in the present invention is a silicate treatment. The silicate treatment will be described below.

The anodized film of the aluminum plate subjected to the treatment as described above has an alkali metal silicate content of 0.1 to 30% by mass, preferably 0.5 to 10% by mass, and a pH at 25 ° C. of 10 to 13. It is immersed in a certain aqueous solution for 0.5 to 120 seconds at 15 to 80 ° C. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution will gel, and if it is higher than 13.0, the oxide film will be dissolved. Examples of the alkali metal silicate used in the present invention include sodium silicate, potassium silicate, and lithium silicate. Examples of the hydroxide used to increase the pH of the alkali metal silicate aqueous solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend alkaline-earth metal salt or Group IVB metal salt with said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Can be mentioned. Examples of Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, and zirconium tetrachloride. Can do. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. A preferable range of these metal salts is 0.01 to 10% by mass, and a more preferable range is 0.05 to 5.0% by mass.
Since the hydrophilicity on the surface of the aluminum plate is further improved by the silicate treatment, the ink hardly adheres to the non-image area during printing, and the stain performance is improved.

(Back coat layer)
A back coat is provided on the back surface of the support as necessary. As such a backcoat, a coating comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 A layer is preferably used.
Among these coating layers, silicon alkoxy compounds such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , and Si (OC ₄ H ₉ ) ₄ are available at a low price. The coating layer of the metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

(Middle layer)
In the lithographic printing plate precursor according to the invention, an intermediate layer may be provided for the purpose of improving the adhesion and soiling between the photosensitive layer and the support. Specific examples of such an intermediate layer include JP-B-50-7481, JP-A-54-72104, JP-A-59-101651, JP-A-60-149491, JP-A-60-232998, JP-A-3-56177, JP-A-4-282737, JP-A-5-16558, JP-A-5-246171, JP-A-7-159983, JP-A-7-314937, JP-A-8-202025, Special Kaihei 8-320551, JP 9-34104, JP 9-236911, JP 9-269593, JP 10-69092, JP 10-115931, JP 10-161317, JP 10-260536, JP-A-10-282682, JP-A-11-84684, Japanese Patent Application No. 8-225335, Japanese Patent Application No. 8-270098, Japanese Patent Application No. 9-195863, Japanese Patent Application No. 9-195864, Japanese Patent Application No. 9-89646, Japanese Patent Application No. 9-106068, Japanese Patent Application No. 9-183834, Japanese Patent Application No. 9-264411, Japanese Patent Application No. 9 -127232, Japanese Patent Application No. 9-245419, Japanese Patent Application No. 10-127602, Japanese Patent Application No. 10-170202, Japanese Patent Application No. 11-36377, Japanese Patent Application No. 11-165661, Japanese Patent Application No. 11-284091 No., Japanese Patent Application No. 2000-14697, and the like.

(Exposure, development and printing)
Since the lithographic printing plate precursor according to the invention has the photosensitive layer in the invention described above, exposure with an infrared laser, exposure with an ultraviolet lamp, and thermal recording with a thermal head are possible. In the present invention, image exposure is preferably performed by a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 760 nm to 1200 nm.

After exposure with an infrared laser, the lithographic printing plate precursor is preferably developed with water or an alkaline aqueous solution.
When an alkaline aqueous solution is used as the developer and replenisher, a conventionally known alkaline aqueous solution can be used. For example, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, Examples include inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used.
These alkali agents are used alone or in combination of two or more.

  Further, when developing using an automatic developing machine, the developer in the developing tank for a long time is added to the developer by adding an aqueous solution (replenisher) that is the same as the developer or higher in alkali strength than the developer. It is known that a large amount of a lithographic printing plate precursor can be processed without replacing the plate. This replenishment method is also preferably applied in the present invention.

  Various surfactants, organic solvents, and the like can be added to the developer and replenisher as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving the ink affinity of the image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Preferred organic solvents include benzyl alcohol. Further, addition of polyethylene glycol or a derivative thereof, or polypropylene glycol or a derivative thereof is also preferable. In addition, non-reducing sugars such as arabit, sorbit and mannitol can be added.

  Further, as necessary, the developer and replenisher may include hydroquinone, resorcin, sulfurous acid or sodium salt of potassium bisulfite, and other inorganic salt-based reducing agents, as well as organic carboxylic acids, antifoaming agents, and water softeners. It can also be added.

  The printing plate developed using the developer and replenisher described above is post-treated with a desensitizing solution containing washing water, a rinsing solution containing a surfactant and the like, gum arabic and starch derivatives. As the post-treatment of the lithographic printing plate precursor according to the invention, these treatments can be used in various combinations.

In recent years, automatic developing machines for printing plate materials have been widely used in the plate making and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for conveying a printing plate material, processing liquid tanks and a spray device. Each processing liquid pumped up is sprayed from a spray nozzle for development processing. In addition, recently, a method is also known in which a printing plate material is immersed and conveyed in a processing liquid tank filled with a processing liquid by a submerged guide roll or the like. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like. In addition, the electrical conductivity can be detected by a sensor and replenished automatically.
In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.

The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if it is desired to obtain a lithographic printing plate with a higher printing durability, a burning treatment is performed. Is given.
In the case of burning a lithographic printing plate, before burning, an adjustment as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, JP-A-61-159655 is used. It is preferable to treat with a surface liquid.

As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a method in which the printing plate is immersed and applied in a vat filled with the surface-adjusting liquid, Application by an automatic coater is applied. Further, it is more preferable to make the coating amount uniform with a squeegee or a squeegee roller after coating.
In general, the amount of surface-adjusting solution applied is suitably 0.03 to 0.8 g / m ² (dry mass).
The lithographic printing plate coated with the surface-adjusting liquid is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor BP-1300 sold by Fuji Photo Film Co., Ltd.). . The heating temperature and time in this case are preferably in the range of 180 to 300 ° C. and in the range of 1 to 20 minutes, although depending on the type of components forming the image.

  The burned lithographic printing plate can be subjected to conventional treatments such as washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound or the like is used. In such a case, a so-called desensitizing treatment such as gumming can be omitted.

  The lithographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets.

  As described above, the lithographic printing plate precursor most suitable as the application of the image forming material of the present invention has been described in detail, but the present invention is not limited to this, and three-dimensional stereolithography, holography, color proof, photoresist and It is also applied to color filters.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not restrict | limited to these.
<Synthesis example>
(Synthesis of polyurethane resin No. 4)
In a 500 mL three-necked flask, 4.5 g of 1,4-butanediol, 6.7 g of 2,2-bis (hydroxymethyl) propionic acid, and 90 g of tetrahydrofuran were added and heated to 50 ° C. to dissolve. To this, 25.8 g of 4,4-diphenylmethane diisocyanate and 0.2 g of dibutyltin dilaurate were added and heated to reflux for 8 hours. Thereafter, 100 ml of methanol was added, and 51 ml of 1.0 M aqueous sodium hydroxide solution was added dropwise while cooling in an ice bath. After completion of the dropwise addition, the organic solvent was distilled off to remove polyurethane resin No. An aqueous solution of 4 was obtained.

[Examples 1 to 8, Comparative Examples 1 and 2]
Hereinafter, the effect of the present invention will be confirmed with reference to an example in which the negative image forming material of the present invention is applied to a lithographic printing plate precursor.
(Production of support)
A molten metal of JIS A1050 alloy containing 99.5% or more of aluminum and Fe 0.30%, Si 0.10%, Ti 0.02%, and Cu 0.013% was subjected to a cleaning treatment and cast. As the cleaning process, a degassing process for removing unnecessary gas such as hydrogen in the molten metal and a ceramic tube filter process were performed. The casting method was a DC casting method. The solidified 500 mm thick ingot was chamfered 10 mm from the surface and homogenized at 550 ° C. for 10 hours so as not to coarsen the intermetallic compound.
Next, after hot rolling at 400 ° C. and intermediate annealing at 500 ° C. for 60 seconds in a continuous annealing furnace, cold rolling was performed to obtain an aluminum rolled plate having a plate pressure of 0.30 mm. By controlling the roughness of the rolling roll, the centerline average surface roughness Ra after cold rolling was controlled to 0.2 μm. Then, it applied to the tension leveler in order to improve planarity.

Next, the surface treatment for making a lithographic printing plate support was performed.
First, in order to remove the rolling oil on the surface of the aluminum plate, degreasing treatment was carried out with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds and smut removal treatment.
Next, in order to improve the adhesion between the support and the recording layer and to provide water retention to the non-image area, a so-called graining treatment was performed to roughen the surface of the support. While maintaining an aqueous solution containing 1% nitric acid and 0.5% aluminum nitrate at 45 ° C. and flowing an aluminum web through the aqueous solution, an alternating waveform with a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect power supply cell Then, electrolytic graining was performed by giving an anode side electric quantity of 240 C / dm ² . Thereafter, etching treatment was performed with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal treatment were performed with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds.

Furthermore, in order to improve wear resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. An anodized film of 2.5 g / m ² by using a 20% sulfuric acid aqueous solution as an electrolyte at 35 ° C. and carrying out an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power feeding cell while carrying an aluminum web into the electrolyte. It was created.

(Formation of photosensitive layer)
A photosensitive layer coating solution 1 having the following composition was prepared, applied to the aluminum support obtained as described above using a wire bar, and dried at 115 ° C. for 45 seconds in a hot air drying apparatus to form a recording layer. Formed. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² .

<Recording layer coating solution 1>
-Component (A): radical initiator “S-1” 0.20 g
-Component (B): polymerizable compound “M-1” 1.00 g
-(C) component: Infrared absorber “IR-1” 0.08 g
-(D) component: Binder polymer "B-1" 1.00g
・ Ethyl violet chloride 0.04g
・ Fluorine surfactant 0.02g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 8.0g
1-methoxy-2-propanol 8.0g

  Here, structural formulas such as radical polymerization initiators, polymerizable compounds, infrared absorbers, binder polymers and the like used in the photosensitive layer coating solutions of Examples and Comparative Examples of the present invention are shown.

Next, the following protective layer coating solution 1 is applied to the surface of the photosensitive layer using a slide hopper, and dried at 120 ° C. for 75 seconds with a hot air dryer to form a protective layer to obtain a lithographic printing plate precursor. It was. In addition, the film weight of the protective layer after application | coating and drying was 2.0-2.2 g / m < ² >.
<Protective layer coating solution 1>
・ High molecular compound (compound described in Table 2) 2.5 g
・ Nonionic surfactant 0.05g
(EMAREX NP-10 manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 96.9g
In Table 2 below, the polymer compound No. 1-No. 18 is an exemplary compound of the specific polyurethane resin according to the present invention. In Comparative Example 1, P-1 is described as a comparative polymer compound: polyvinyl alcohol PVA105 (Kuraray Co., Ltd.). ))).

(1) Sensitivity evaluation The obtained lithographic printing plate precursor was set at a log E of 0.00 with a resolution of 175 lpi, an external drum rotation speed of 150 rpm, and an output of 0 to 8 W, using a Trend setter 3244VX manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser. The exposure was changed by 15 steps.
After the exposure, the protective layer was removed by washing with tap water, and then developed at 30 ° C. for 12 seconds using an automatic developing machine LP-1310HII manufactured by Fuji Photo Film Co., Ltd. The developer used was a 1: 4 water-diluted water of DV-2 manufactured by FUJIFILM Corporation, and the 1: 1 water-diluted solution of FP-2W manufactured by FUJIFILM Corporation was used as the finisher.
The amount of energy required for recording was calculated based on the line width and laser output of the image obtained by the exposure and development, the loss in the optical system, and the scanning speed. The smaller the value, the higher the sensitivity.

(2) Evaluation of scratch resistance The scratch resistance of the lithographic printing plate precursor coated with the photosensitive layer and the protective layer was evaluated. As a device, a scratching tester HEIDON-14 manufactured by HEIDON was used, a 0.4 mmR diamond needle was used as a scratching needle, and the surface of the recording layer was scratched at a speed of 400 mm / min while changing the load on the needle. The original plate after scratching was subjected to the development process described above, and the magnitude of the load in which the remaining film was visually observed was evaluated. As the load is larger, a scratched film is less likely to occur and the scratch resistance is better. The results are also shown in Table 2.

  From the results shown in Table 2, the lithographic printing plate precursor of the present invention can be recorded with high sensitivity and is more resistant than the lithographic printing plate precursor of Comparative Example 1 provided with a protective layer using polyvinyl alcohol as a main component. It can be seen that the scratch resistance is extremely excellent.

[Examples 9 to 16, Comparative Examples 3 and 4]
(Formation of recording layer)
A recording layer coating solution 2 having the following composition was prepared, applied to the same aluminum support obtained in the above manner using Example 1 using a wire bar, and dried at 115 ° C. for 45 seconds using a hot air dryer. Thus, a recording layer was formed. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² .

<Recording layer coating solution 2>
-(A) component: 0.25g of radical initiator "S-1"
Component (B): polymerizable compound “M-1” 1.20 g
-(C) component: Infrared absorber “IR-1” 0.08 g
-(D) component: Binder polymer "B-1" 1.00g
・ Ethyl violet chloride 0.04g
・ Fluorine surfactant 0.02g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 8.0g
1-methoxy-2-propanol 8.0g

Next, the following protective layer coating solution 2 was applied to the surface of the photosensitive layer using a slide hopper, dried at 120 ° C. for 75 seconds with a hot air dryer to provide a protective layer, and a lithographic printing plate precursor was obtained. . In addition, the film weight of the protective layer after application | coating and drying was 2.0-2.2 g / m < ² >.
<Protective layer coating solution 2>
Specific polymer compound (compound described in Table 3) 2.0 g
・ Other polymer compounds 0.5g
・ Nonionic surfactant 0.04g
(EMAREX NP-10 manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 96.9g
In Table 3 below, polymer compound no. 1-No. 15 is an exemplary compound of the specific polyurethane resin according to the present invention, and P-1 is the same compound used in Comparative Example 1, and is described as P-2. Is a comparative polymer compound: polyvinylpyrrolidone K30 (manufactured by Tokyo Chemical Industry Co., Ltd.).

The sensitivity evaluation was performed on the obtained lithographic printing plate precursor in the same manner as in Example 1. The results are shown in Table 3 below.
(2) Evaluation of developability The obtained negative lithographic printing plate precursor was output by a Creo Trendsetter 3244VFS equipped with a water-cooled 40 W infrared semiconductor laser, output 9 W, outer drum rotation speed 210 rpm, plate energy 100 mJ / cm ^2. The exposure was performed under the condition of a resolution of 2400 dpi.
(Development processing)
After the exposure, the film was developed using an automatic processor Stablon 900N manufactured by Fuji Photo Film Co., Ltd. As the developer, a 1: 4 water diluted solution of DV-2 manufactured by Fuji Photo Film Co., Ltd. was used for both the feed solution and the replenisher solution. The temperature of the developing bath was 30 ° C. As the finisher, a 1: 1 water dilution (pH = 10.8) of FN-6 manufactured by Fuji Photo Film Co., Ltd. was used. Here, development was carried out while changing the conveyance speed of the automatic developing machine, and the developer immersion time necessary for removing the non-image area of the printing plate was measured. It shows that it is excellent in developability, so that a numerical value is small. The results are shown in Table 3.

  As is apparent from Table 3, the lithographic printing plate precursor provided with a protective layer containing the specific polyurethane resin according to the present invention and another water-soluble polymer compound can be recorded with high sensitivity and developability, in particular, It can be seen that the developability is excellent when stored under high temperature / high humidity conditions.

[Examples 17 to 28, Comparative Examples 5 to 7]
<Undercoat>
The following undercoat liquid was applied to the same aluminum support as in Example 1 with a wire bar, and dried at 90 ° C. for 30 seconds using a hot air dryer. The coating amount after drying was 10 mg / m ² .

<Undercoat liquid>
A copolymer of ethyl acrylate and 2-acrylamido-2-methyl-1-propane sulfonic acid sodium salt in a molar ratio of 75:15 0.1 g
・ 2-aminoethylphosphonic acid 0.1g
・ Methanol 50g
・ Ion exchange water 50g

(Formation of recording layer)
A recording layer coating solution 3 having the following composition was prepared, applied to the aluminum support obtained as described above using a wire bar, and dried at 115 ° C. for 45 seconds with a hot air drying apparatus to form a recording layer. Formed. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² .

<Recording layer coating solution 3>
-Component (A): radical initiator “S-1” 0.30 g
-Component (B): polymerizable compound “M-1” 1.00 g
-(C) component: Infrared absorber “IR-1” 0.08 g
-(D) component: Binder polymer (compound of Table 4) 1.20g
・ Ethyl violet chloride 0.04g
・ Fluorine surfactant 0.02g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 8.0g
1-methoxy-2-propanol 8.0g

Next, the following protective layer coating solution 3 was applied to the surface of the photosensitive layer using a slide hopper, dried at 120 ° C. for 75 seconds with a hot air dryer to provide a protective layer, and a lithographic printing plate precursor was obtained. . The film weight of the protective layer after coating and drying was 1.3 to 1.6 g / m ² .
<Protective layer coating solution 3>
Specific polymer compound (compound described in Table 4) 2.0 g
・ Nonionic surfactant 0.03g
(EMAREX NP-10 manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 96.9g
In Table 4 below, polymer compound No. 4-No. What is described as 24 is an exemplary compound of the specific polyurethane resin according to the present invention, and P-1 is the same polymer compound used in Comparative Example 1.

(1) Evaluation of printing durability The obtained negative type lithographic printing plate precursor was output by a Creo Trendsetter 3244VFS equipped with a water-cooled 40 W infrared semiconductor laser, output 9 W, outer drum rotation speed 210 rpm, plate surface energy 100 mJ / cm. ^2. Exposure was performed under conditions of a resolution of 2400 dpi.
(Development processing)
After the exposure, the film was developed using an automatic processor Stablon 900N manufactured by Fuji Photo Film Co., Ltd. As the developer, a 1: 4 water diluted solution of DV-2 manufactured by Fuji Photo Film Co., Ltd. was used for both the feed solution and the replenisher solution. The temperature of the developing bath was 30 ° C. As the finisher, a 1: 1 water dilution (pH = 10.8) of FN-6 manufactured by Fuji Photo Film Co., Ltd. was used.
[Evaluation of printing durability]
The lithographic printing plate obtained by exposure and development in the same manner as in Example 1 was printed using a GEOS-G (N) ink manufactured by Dainippon Ink Co., Ltd. with a R201 printer manufactured by Roland. The printed matter in the solid image area was observed, and the image began to fade. Printing durability was examined by the number of sheets. The larger the number, the better the printing durability. The results are also shown in Table 4. Further, the developability was evaluated by the same method as in Example 9. The results are also shown in Table 4 below.

  As is apparent from Table 4, the lithographic printing plate precursor provided with the protective layer containing the specific polyurethane resin according to the present invention is similar to the case where the specific polyurethane resin and other water-soluble polymer compound are used in combination. It can be seen that recording is possible with sensitivity, and that developability, in particular, developability when stored under high temperature / high humidity conditions is excellent.

[Examples 30 to 37, Comparative Examples 8 and 9]
(Formation of recording layer)
A recording layer coating solution 4 having the following composition was prepared, applied to the same aluminum support as in Example 10 using a wire bar, and dried at 115 ° C. for 45 seconds with a hot air dryer to form a recording layer. . The coating amount after drying was in the range of 1.5 to 1.7 g / m ² .

<Recording layer coating solution 4>
-(A) component: 0.25g of radical initiator "S-1"
Component (B): polymerizable compound “M-2” 1.20 g
-(C) component: Infrared absorber “IR-1” 0.09 g
-(D) component: Binder polymer "B-4" 1.00g
・ Ethyl violet chloride 0.04g
・ Fluorine surfactant 0.02g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 8.0g
1-methoxy-2-propanol 8.0g

Furthermore, the following protective layer coating solution 4 was applied using a slide hopper and dried at 120 ° C. for 75 seconds with a hot air dryer to obtain a lithographic printing plate precursor. The film weight of the protective layer after coating and drying was 2.0 to 2.2 g / m ² .
<Protective layer coating solution 4>
Specific polymer compound (compound described in Table 5) 2.5 g
・ Nonionic surfactant 0.04g
(EMAREX NP-10 manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 96.9g
In Table 5 below, polymer compound No. 1-No. 27 is an exemplary compound of the specific polyurethane resin according to the present invention, and P-1 is the same polymer compound used in Comparative Example 1.

(1) Evaluation of printing durability Printing durability was evaluated in the same manner as in Example 19. The results are also shown in Table 5.
(2) Evaluation of adhesion The obtained lithographic printing plates are stacked so that the surface having the photosensitive layer and the back surface of the support are in contact with each other, and a load of 500 kg / m ² is applied, and the temperature is 30 ° C. and 75% RH. It was left in the environment for 10 days.
Then, the adhesion state of the sensitive material surface and the back surface was confirmed. The adhesion state at that time was subjected to sensory evaluation in five stages from 1 to 5 where adhesion was difficult to peel off to 5 that could be peeled without adhesion problems, and the results are also shown in Table 4. Evaluation result 3 is a practical lower limit level, and 2 or less is a practically impossible level.
(3) Evaluation of development residue An unexposed lithographic printing plate precursor using a G & J automatic developing machine IP85HD, the line speed (conveyance speed) of 1.5 m / min for a total of 1000 m ² minutes without operating the heating part The development processing was performed. In the development process, the same developer as in the example was used. Thereafter, the stain on the developer tank was visually observed. The sensory evaluation is performed in five stages from 1 to 5 ranging from 1 where the level of soiling is significant to 5 where no level of soiling is observed. 2 or less is impractical and 3 is the practical lower limit level. The evaluation results are shown in Table 5.

  As is apparent from Table 5, the planographic printing plate precursors of the examples provided with the protective layer containing the specific polyurethane resin according to the present invention have excellent printing durability and are adjacent to the protective layer surface even when stored repeatedly. It can be seen that there is no problem of adhesion to the support, excellent handling properties, and development debris is suppressed.

[Examples 38 to 44, Comparative Examples 10 to 14]
(Formation of recording layer)
A recording layer coating solution 5 having the following composition was prepared, applied to the same aluminum support as that used in Example 10 using a wire bar, and dried at 115 ° C. for 45 seconds with a hot air dryer to record. A layer was formed. The coating amount after drying was in the range of 1.5 to 1.7 g / m ² .

<Recording layer coating solution 5>
-Component (A): radical initiator (compound described in Table 6) 0.30 g
-Component (B): polymerizable compound “M-3” 1.00 g
-Component (C): infrared absorber (compound described in Table 5) 0.08 g
-(D) component: Binder polymer "B-1" 1.00g
・ Ethyl violet chloride 0.04g
・ Fluorine surfactant 0.02g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 8.0g
1-methoxy-2-propanol 8.0g

Next, the following protective layer coating solution 5 is applied to the surface of the photosensitive layer using a slide hopper, dried at 120 ° C. for 75 seconds with a hot air dryer to provide a protective layer, and a lithographic printing plate precursor is obtained. It was. In addition, the film weight of the protective layer after application | coating and drying was 1.8-2.0 g / m < ² >.
<Protective layer coating solution 5>
Specific polymer compound (compound described in Table 6) 2.5 g
・ Nonionic surfactant 0.04g
(EMAREX NP-10 manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 96.9g
In Table 6 below, polymer compound No. 8 and no. 11 is an exemplary compound of the specific polyurethane resin according to the present invention, and P-1 is the same polymer compound used in Comparative Example 1.

  As is apparent from Table 6, the planographic printing plate precursors of the examples provided with the protective layer containing the specific polyurethane resin according to the present invention can be recorded with high sensitivity and have excellent scratch resistance. .

[Examples 45 to 52, Comparative Example 14]
The same support as in Example 1 was used, except that the recording layer coating solution 1 in which 0.10 g of the following compound J-1 was added thereto was used instead of the recording layer coating solution 1 used in Example 1. A recording layer was provided in the same manner as in Example 1.
Next, the following protective layer coating solution 6 was applied to the surface of the recording layer using a slide hopper, and dried at 120 ° C. for 75 seconds with a hot air dryer to provide a protective layer, whereby a lithographic printing plate precursor was obtained. . In addition, the film weight of the protective layer after application | coating and drying was 1.8-2.0 g / m < ² >.

-Preparation of mica dispersion liquid 16 g of synthetic mica ("Somasif ME-100" manufactured by Co-op Chemical Co., aspect ratio: 1000 or more) was added to 184 g of water, and the average particle size (laser scattering method) was adjusted to 3 µm using a homogenizer. To obtain a mica dispersion.
<Protective layer coating solution 6>
Specific polymer compound (compound described in Table 7) 88.0 g
・ Mica dispersion (6g or not added)
・ Nonionic surfactant 2.00g
(EMAREX NP-10 manufactured by Nippon Emulsion Co., Ltd.)
・ Ion exchange water 190.0g
In Table 7 below, polymer compound No. 1-No. 27 is an exemplary compound of the specific polyurethane resin according to the present invention, and P-1 is the same polymer compound used in Comparative Example 1. In Table 7, “with” mica dispersion is an example using 6 g of mica dispersion added to the protective layer coating liquid 6, and “without” means protection without adding mica dispersion. This is an example using the layer coating solution 6.

  The resulting lithographic printing plate precursor was evaluated for sensitivity and scratch resistance in the same manner as in Example 1, and in the same manner as in Example 30, adhesiveness was evaluated. The results are also shown in Table 7.

  From Table 7, it can be seen that the planographic printing plate precursor of the present invention can form an image with high sensitivity and is excellent in scratch resistance and adhesiveness. Further, by comparing Example 45 and Example 51, Example 46 and Example 52, etc., it can be seen that by adding mica to the protective layer, the adhesion suppressing effect is further improved while maintaining high sensitivity. .

Claims (6)

  On the support, (A) a radical initiator and (B) a radical polymerizable compound, a photosensitive layer that causes a curing reaction by light or heat, and a polyurethane resin that is soluble in water and / or alkaline water A negative image forming material comprising a protective layer and a protective layer in this order.   The negative image forming material according to claim 1, wherein the polyurethane resin is water-soluble.   The negative image forming material according to claim 2, wherein the water-soluble polyurethane resin is a polyurethane resin having a carboxyl group in a side chain.   4. The negative image forming material according to claim 3, wherein the water-soluble polyurethane resin is a water-soluble polyurethane resin in which a part or all of the carboxyl groups present in the side chain are neutralized with an alkali.   The negative image-forming material according to claim 1, further comprising (C) a sensitizing dye in the photosensitive layer.   6. The negative image forming material according to claim 5, wherein the (C) sensitizing dye is a dye having absorption in the infrared region.