JP2011073214A - Original printing plate for lithographic printing plate and method for manufacturing printing plate for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original printing plate for a lithographic printing plate which suppresses fog under the illumination of a mercury lamp, and in which high printing plate wear and press stability are made compatible. <P>SOLUTION: The original printing plate for the lithographic printing plate has an image recording layer comprising (A) an infrared ray absorbing agent, (B) a radical polymerization initiator, and (C) a polymerizable compound on a substrate, and can form an image by feeding at least one of a printing ink and dampening water on a printing machine after image exposure to remove a non-exposed part of the image recording layer, and is characterized in that the image recording layer furthermore comprises (D) an ultraviolet ray absorbing agent having at least one polyoxyalkylene structure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a lithographic printing plate precursor, and more particularly to a lithographic printing plate precursor containing an ultraviolet absorber having a specific partial structure in an image recording layer. More specifically, it has an image recording layer containing (A) an infrared absorber, (B) a radical polymerization initiator, (C) a polymerizable compound, and (D) an ultraviolet absorber having a specific partial structure. The present invention relates to a lithographic printing plate precursor capable of forming an image by supplying printing ink and fountain solution on a printing machine after exposure and removing an unexposed portion, which is excellent in handleability under a mercury lamp.
The present invention further relates to a lithographic printing plate precursor that achieves both high printing durability and on-press developability.

In general, a lithographic printing plate comprises an oleophilic image area that receives ink in the printing process and a hydrophilic non-image area that receives dampening water. Lithographic printing utilizes the property that water and oil-based inks repel each other, so that the oleophilic image area of the lithographic printing plate is the ink receiving area, and the hydrophilic non-image area is dampened with the water receiving area (ink non-receiving area). As described above, a difference in ink adhesion is caused on the surface of a lithographic printing plate, and after ink is applied only to an image portion, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, conventionally, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support has been widely used. Usually, after exposing the lithographic printing plate precursor through an original image such as a lithographic film, the image recording layer corresponding to the image portion remains, and the unnecessary image recording layer corresponding to the non-image portion is removed with an alkaline developer. Alternatively, the lithographic printing plate is obtained by dissolving and removing with an organic solvent-containing developer and exposing the surface of the hydrophilic support to form a non-image area.

  On the other hand, in recent years, digitization technology for electronically processing, storing, and outputting image information by a computer has become widespread, and various new image output methods corresponding to such digitization technology will be put into practical use. It is becoming. Along with this, digitized image information is carried by high-convergence radiation such as laser light, and the lithographic printing plate precursor is scanned and exposed with that light, directly without using a lithographic film. Computer-to-plate (CTP) technology has been attracting attention. Therefore, obtaining a lithographic printing plate precursor adapted to such a technology is one of the important technical issues.

Furthermore, in the conventional plate making process of a lithographic printing plate precursor, a step of dissolving and removing an unnecessary image recording layer with a developer or the like is necessary after exposure, but such additional wet processing is unnecessary. Simplification or simplification is also cited as one of the problems. In particular, in recent years, disposal of waste liquid discharged with wet processing has become a major concern for the entire industry due to consideration of the global environment, and the demand for solving the above-mentioned problems has become stronger.
On the other hand, as one simple plate making method, an image recording layer that can remove an unnecessary portion of the image recording layer in a normal printing process is used. A method called on-press development has been proposed in which unnecessary portions are removed to obtain a lithographic printing plate.
As a specific method of on-press development, for example, a method of using a lithographic printing plate precursor having an image recording layer that can be dissolved or dispersed in an fountain solution, an ink solvent, or an emulsion of a fountain solution and an ink. , Method of mechanically removing the image recording layer by contact with rollers or blankets of a printing press, cohesion of the image recording layer or adhesion between the image recording layer and the support by penetration of dampening water, ink solvent, etc. There is a method in which after the force is weakened, the image recording layer is mechanically removed by contact with rollers or a blanket.

  In the present invention, unless otherwise specified, the “development process step” means that a device other than a printing machine (usually an automatic developing machine) is used and a liquid (usually containing an alkaline developer and a surfactant). This refers to the process of removing the image recording layer of the unexposed portion of the lithographic printing plate precursor by contacting the developer and an aqueous solution containing a hydrophilic polymer, and exposing the surface of the hydrophilic support. "The surface of the hydrophilic support is removed by removing the image recording layer of the lithographic printing plate precursor by contacting a liquid (usually printing ink and / or fountain solution) with a printing machine. Refers to methods and processes for exposing

  In the above-described simplification, drying, or no processing of the plate-making operation, the image recording layer after exposure is not fixed by the development processing, and thus has photosensitivity and may cause a cover before printing. Therefore, an image recording layer and a light source that can be handled in a bright room or under a yellow light are preferably used. As such a light source, a solid-state laser such as a semiconductor laser and a YAG laser that emits infrared light having a wavelength of 760 to 1200 nm is extremely useful because a high-power and small-sized laser can be obtained at low cost.

  In a lithographic printing plate precursor using such a light source, handleability is considerably improved in a bright room or under a yellow lamp, but in the process from plate making to printing, a mercury lamp containing ultraviolet rays may be used as illumination, When the on-press development type lithographic printing plate precursor is allowed to stand for a long time under such conditions, there has been a problem that the covering is caused and the removability of the non-image area at the on-press development is lowered.

As a method for improving the above-described covering, there has been proposed a method in which an ultraviolet absorber is contained in an oxygen blocking layer provided in an upper layer of an image recording layer in an alkali development type CTP (see, for example, Patent Document 1). This method is an effective technique for a lithographic printing plate subjected to an alkali development treatment, but in an on-press development type lithographic printing plate precursor, an on-press developability resulting from the addition of an additive to the oxygen barrier layer. Decrease occurred and the effect might be insufficient.
As an example of adding an ultraviolet absorber to an image recording layer, a lithographic printing plate precursor containing an ultraviolet absorber in the wall of a microcapsule is known (see, for example, Patent Document 2). This method is effective in improving the stability of the microcapsules in the heat-fusing or polarity conversion type image forming layer, but since the ultraviolet absorber is not uniformly present in the image recording layer, radical polymerization is performed. The higher-sensitivity on-press development type lithographic printing plate used has a problem that it has little effect on mercury lamp covering and lacks practicality.

  A lithographic printing plate precursor containing a dye having an absorption maximum wavelength at 350 to 550 nm is disclosed as an example of adding a compound having absorption on the short wavelength side in the visible region to the image recording layer for the purpose of improving white light stability. (For example, see Patent Document 3). However, such a lithographic printing plate precursor is not sufficiently effective under a mercury lamp, and when used in an on-press development type lithographic printing plate that is a feature of the present invention, the dye is in the visible range. Because it has absorption, non-image areas are also colored when inspecting after exposure, making it difficult to inspect, fountain solution is colored when developed on-machine, and dye adheres to the white background of printed matter and becomes dirty There was a problem that it could not withstand practical use.

Japanese Patent No. 4279656 Japanese Patent No. 42222026 JP 2007-127947 A

  An object of the present invention is to provide a lithographic printing plate precursor which is excellent in handleability under a mercury lamp and further has both high printing durability and on-press developability.

As a result of studying various image recording layer compositions, the present inventors have found that (A) an infrared absorber, (B) a radical polymerization initiator, (C) a polymerizable compound, and (D) a polyoxyalkylene structure. The lithographic printing plate precursor having an image recording layer containing at least one UV absorber having excellent handling properties under a mercury lamp, and furthermore, an unexpected effect capable of achieving both high printing durability and on-press developability The present invention has been found.
That is, the present invention is as follows.

1. On the support, it has an image recording layer containing (A) an infrared absorber, (B) a radical polymerization initiator, and (C) a polymerizable compound, and printing ink and dampening water on the printing press after image exposure. A lithographic printing plate precursor capable of forming an image by supplying at least one of the above and removing an unexposed portion of the image recording layer, wherein the image recording layer further comprises (D) a polyoxyalkylene structure. A lithographic printing plate precursor comprising an ultraviolet absorber having one.
2. 2. The lithographic printing plate precursor as described in 1 above, wherein the polyoxyalkylene structure is represented by the following general formula (A).

Formula (A)-(CHR ₁₀₁ CHR ₁₀₂ O) _n -R ₁₀₃

In the formula, R ₁₀₁ and R ₁₀₂ each independently represent a hydrogen atom or a substituent, and R ₁₀₃ represents a hydrogen atom or a substituent. n represents an integer of 2 to 50.

3. In the polyoxyalkylene structure represented by the general formula (A), R ₁₀₁ and R ₁₀₂ each independently represent a hydrogen atom or a methyl group, and R ₁₀₃ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 2. The lithographic printing plate precursor as described in 2 above.

4). The ultraviolet absorber is at least one selected from compounds represented by the following formulas (1), (2) and (4) to (9). The lithographic printing plate precursor as described in any one of 1 to 3 above.

In the formula, R _{11 to} R ₁₈ each independently represents a hydrogen atom or a substituent. However, at least one of R _{11 to} R ₁₈ represents a group having a polyoxyalkylene structure.

_Wherein, X 21 _{to X 23} each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a heterocyclic group. However, at least one of X _{21 to} X ₂₃ represents a group represented by the following general formula (3), and at least one of X _{21 to} X ₂₃ and R _{31 to} R ₃₄ has a polyoxyalkylene structure. Represents a group having

_Wherein, R 31 _{to R 34} each independently represent a hydrogen atom or a substituent.

_Wherein, R 40 _{to R 49} each independently represent a hydrogen atom or a substituent. However, at least one of R _{40 to} R ₄₉ represents a group having a polyoxyalkylene structure. X ₄₁ represents —CO— or —COO—.

_Wherein, R 51 _{to R 55} each independently represent a hydrogen atom or a substituent. X ₅₁ represents a hydrogen atom or an alkyl group, and Y ₅₁ and Y ₅₂ each independently represent a hydrogen atom, a cyano group, —COOZ ₅₁ , —CONHZ ₅₁ , —COZ ₅₁ , —SO ₂ Z ₅₁ or —SO ₂ NHZ. ₅₁ , and Z ₅₁ represents a hydrogen atom, an alkyl group, or an aryl group. Y ₅₁ and Y ₅₂ may be connected to each other to form a ring. However, at least one of R _{51 to} R ₅₅ , Y ₅₁ and Y ₅₂ represents a group having a polyoxyalkylene structure.

In the formula, R ₆₁ and R ₆₂ each independently represent a hydrogen atom, an alkyl group, or an aryl group. R ₆₁ and R ₆₂ may be connected to each other to form a 5- or 6-membered ring. Y ₆₁ and Y ₆₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R ₆₁ , R ₆₂ , Y ₆₁ and Y ₆₂ represents a group having a polyoxyalkylene structure.

_Wherein, R 70 _{to R 79} each independently represent a hydrogen atom or a substituent. X ₇₁ and X ₇₂ each independently represent a hydrogen atom, an alkyl group or an aryl group. However, at least one of R _{70 to} R ₇₉ , X ₇₁ and X ₇₂ represents a group having a polyoxyalkylene structure.

In formula, R < ₈₁ > -R < ₈₄ > represents a hydrogen atom or a substituent each independently. L ₈₁ represents a single bond or a double bond. However, when L ₈₁ represents a double bond, R ₈₁ and R ₈₄ are not present. R ₈₂ and R ₈₃ may be bonded to each other to form a ring. X ₈₁ represents an alkyl group or an aryl group. Z ₈₁ represents an oxygen atom, a sulfur atom, —N (R ₈₅ ) — or —C (R ₈₆ ) (R ₈₇ ) —, R ₈₅ represents an alkyl group or an aryl group, and R ₈₆ and R ₈₇ each represent Independently, it represents a hydrogen atom or an alkyl group, and R ₈₆ and R ₈₇ may be bonded to each other to form a ring. Y ₈₁ and Y ₈₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R _{81 to} R ₈₄ , X ₈₁ , Y ₈₁ , Y ₈₂ and Z ₈₁ represents a group having a polyoxyalkylene structure. n represents 0 or 1.

_Wherein, R 91 _{to R 94} each independently represent a hydrogen atom or a substituent. Y ₉₁ and Y ₉₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R _{91 to} R ₉₄ , Y ₉₁ and Y ₉₂ represents a group having a polyoxyalkylene structure.

5). The lithographic printing plate precursor as described in any one of 1 to 4 above, wherein the image recording layer further contains (E) a polymer compound containing a polyoxyalkylene structure.
6). The lithographic printing plate precursor as described in any one of 1 to 5 above, wherein an oxygen blocking layer is provided on an upper layer of the image recording layer.
7). The lithographic printing plate precursor according to any one of 1 to 6 above, after exposure, without passing through a development processing step, supply at least one of printing ink and fountain solution on a printing press to remove an unexposed portion. A method for making a lithographic printing plate, comprising removing the lithographic printing plate to produce a lithographic printing plate.

  According to the present invention, it is possible to provide a lithographic printing plate precursor that is excellent in handleability under a mercury lamp and that can achieve both high printing durability and on-press developability.

[Lithographic printing plate precursor]
The lithographic printing plate precursor according to the invention has, on the support, (A) an infrared absorber, (B) a radical polymerization initiator, (C) a polymerizable compound, and (D) an ultraviolet ray having at least one polyoxyalkylene structure It has an image recording layer containing an absorbent.
The lithographic printing plate precursor according to the present invention is a radical polymerization negative lithographic printing plate precursor, and forms an image by removing at least one of the unexposed portions by supplying printing ink and dampening water on a printing machine after exposure. It can be used as an on-press development type lithographic printing plate precursor. The lithographic printing plate precursor according to the invention can also be used as a negative lithographic printing plate precursor that undergoes development processing.

(UV absorber)
In the present invention, the ultraviolet absorber represents, for example, those described in the third edition of the Practical Plastic Glossary (Plastics Age, revised on September 10, 1989), and specifically absorbs substantially in the visible region. It is a compound that absorbs ultraviolet rays and can be efficiently dispersed into thermal energy without being possessed, and is stable to light.
As the chromophore of the UV absorber preferably used in the present invention, benzotriazole compounds, triazine compounds, benzophenone compounds, salicylic acid compounds, cinnamic acid ester compounds, azole compounds, benzodithiol compounds, azo compounds, azine compounds, and the like are known. Any one of the above may be used, but it is selected from the compounds represented by the formulas (1), (2), (4) to (9) of the present invention. Is preferred.

<Polyoxyalkylene structure>
The ultraviolet absorber of the present invention is characterized by containing a polyoxyalkylene structure. Here, “alkylene” is preferably —CH ₂ CH ₂ — or — (CH ₂ ) ₃ —, and may have a substituent instead of a hydrogen atom. The polyoxyalkylene structure is preferably a structure represented by the general formula (A). When the ultraviolet absorber of the present invention has a plurality of polyoxyalkylene structures, these may be the same or different.

Formula (A)-(CHR ₁₀₁ CHR ₁₀₂ O) _n -R ₁₀₃

In the formula, R ₁₀₁ and R ₁₀₂ each independently represent a hydrogen atom or a substituent, and R ₁₀₃ represents a hydrogen atom or a substituent. n represents a number from 2 to 50. n is preferably 2 to 40.

R ₁₀₁ and R ₁₀₂ will be described in detail. R ₁₀₁ and R ₁₀₂ represent a hydrogen atom or a substituent. When R ₁₀₁ and R ₁₀₂ represent a substituent, examples of the substituent include alkyl groups having 1 to 40 carbon atoms (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, 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, benzyl group, allyl group, etc.), alkenyl group having 2 to 40 carbon atoms (vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl- 1-propenyl group, 1-cyclopentenyl group, 1-cyclohexenyl group, etc.), 2 to 4 carbon atoms Alkynyl group (ethynyl, 1-propynyl, 1-butynyl group, 1-octynyl), a halogen atom (-F, -Br, -Cl, -I), and the like. These groups may further have a substituent.

R ₁₀₁ and R ₁₀₂ preferably include a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a halogen atom (—F, —Br, —Cl, —I) and the like.
More preferred examples of R ₁₀₁ and R ₁₀₂ include a hydrogen atom and an alkyl group having 1 to 20 carbon atoms.
R ₁₀₁ and R ₁₀₂ are particularly preferably a hydrogen atom and a methyl group.

R ₁₀₃ will be described in detail. R ₁₀₃ represents a hydrogen atom or a substituent. When R ₁₀₃ represents a substituent, examples of the substituent include an alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, and an aryl having 6 to 40 carbon atoms. Group, heterocyclic group, alkylcarbonyl group, alkenylcarbonyl group, arylcarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N-arylcarbamoyl group, N, N-dialkylcarbamoyl group, N, N- Examples thereof include a diarylcarbamoyl group, an N-alkyl-N-arylcarbamoyl group, an alkylsulfo group, an arylsulfo group, a sulfo group (—SO ₃ H), and a conjugate base group thereof.

The substituent represented by R ₁₀₃ is preferably a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, a heterocyclic group, an alkylcarbonyl group, an arylcarbonyl group, a carbamoyl group, N -Alkylcarbamoyl group, N-arylcarbamoyl group, N, N-dialkylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group and the like, more preferably hydrogen atom, carbon number 1 to 40 alkyl groups, aryl groups having 6 to 40 carbon atoms, heterocyclic groups, alkylcarbonyl groups, arylcarbonyl groups, carbamoyl groups, N-alkylcarbamoyl groups, N-arylcarbamoyl groups, N, N-dialkylcarbamoyl groups N, N-diarylcarbamoyl group, N-alkyl- N-arylcarbamoyl group etc. are mentioned.
R ₁₀₃ is particularly preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.
The reason why a hydrogen atom and an alkyl group having 1 to 10 carbon atoms are particularly preferable as R ₁₀₃ is not clear in detail, but the higher the volume fraction of the polyoxyalkylene structural unit in the entire substituent, the more the effect of the present invention. Is presumably given.

  Hereinafter, although the preferable example of the polyoxyalkylene structure of this invention is given, this invention is not limited to these.

_{- (CH 2 CH 2 O)} 2 -H, - (CH 2 CH 2 O) 3 -H, - (CH 2 CH 2 O) 4 -H,
_{- (CH 2 CH 2 O)} 5 -H, - (CH 2 CH 2 O) 8 -H, - (CH 2 CH 2 O) 10 -H,
_{- (CH 2 CH 2 O)} 12 -H, - (CH 2 CH 2 O) 16 -H, - (CH 2 CH 2 O) 20 -H,
_{- (CH 2 CH 2 O)} 40 -H, - (CH 2 CH 2 O) 2 -CH 3, - (CH 2 CH 2 O) 3 -CH 3,
_{- (CH 2 CH 2 O)} 4 -CH 3, - (CH 2 CH 2 O) 5 -CH 3, - (CH 2 CH 2 O) 8 -CH 3,
_{- (CH 2 CH 2 O)} 10 -CH 3, - (CH 2 CH 2 O) 12 -CH 3, - (CH 2 CH 2 O) 16 -CH 3,
_{- (CH 2 CH 2 O)} 20 -CH 3, - (CH 2 CH 2 O) 40 -CH 3, - (CH 2 CH 2 O) 2 -C 2 H 5,
_{- (CH 2 CH 2 O)} 3 -C 2 H 5, - (CH 2 CH 2 O) 4 -C 2 H 5, - (CH 2 CH 2 O) 8 -C 2 H 5, - (CH 2 CH _{2 O) 12 -C 2 H 5} , - (CH 2 CH 2 O) 20 -C 2 H 5, - (CH 2 CH 2 O) 40 -C 2 H 5,
_{- (CH 2 CH 2 O)} 2 -C 3 H 7, - (CH 2 CH 2 O) 2 -C 4 H 9, - (CH 2 CH 2 O) 4 -C 4 H 9,
_{- (CH 2 CH 2 O)} 8 -C 4 H 9, - (CH 2 CH 2 O) 2 -C 5 H 11, - (CH 2 CH 2 O) 2 -C 6 H 13,
_{- (CH 2 CH 2 O)} 4 -C 6 H 13, - (CH 2 CH 2 O) 8 -C 6 H 13, - (CH 2 CH 2 O) 2 -C 6 H 5,
_{- (CH 2 CH 2 O)} 4 -C 6 H 5, - (CH 2 CH 2 O) 8 -C 6 H 5, - (CH 2 CH 2 O) 2 - (c-) C 6 H 11
[Wherein (c-) C ₆ H ₁₁ represents a cyclohexyl group],
_{- (CH 2 CH 2 O)} 4 - (c-) C 6 H 11,
_{- (CH 2 CH 2 O)} 8 - (c-) C 6 H 11, - (CH 2 CH 2 O) 2 -C 7 H 15,
_{- (CH 2 CH 2 O)} 2 -CH 2 C 6 H 5, - (CH 2 CH 2 O) 4 -CH 2 C 6 H 5,
_{- (CH 2 CH 2 O)} 8 -CH 2 C 6 H 5, - (CH 2 CH 2 O) 2 -C 8 H 17, - (CH 2 CH 2 O) 4 -C 8 H 17,
_{- (CH 2 CH 2 O)} 8 -C 8 H 17, - (CH 2 CH 2 O) 2 -C 9 H 19, - (CH 2 CH 2 O) 2 -C 10 H 21,
_{- (CH 2 CH 2 O)} 4 -C 10 H 21, - (CH 2 CH 2 O) 2 -C 12 H 25, - (CH 2 CH 2 O) 4 -C 12 H 25,
_{- (CH 2 CH 2 O)} 2 -C 14 H 29, - (CH 2 CH 2 O) 4 -C 14 H 29, - (CH 2 CH 2 O) 2 -C 16 H 33,
_{- (CH 2 CH 2 O)} 4 -C 16 H 33, - (CH 2 CH 2 O) 2 -C 18 H 37, - (CH 2 CH 2 O) 4 -C 18 H 37,
_{- (CH 2 CH 2 O)} 2 -C 20 H 41, - (CH 2 CH 2 O) 4 -C 20 H 41, - (CH 2 CH 2 O) 2 -C 22 H 45,
_{- (CH 2 CH 2 O)} 4 -C 22 H 45

_{- (CH 2 CH (CH 3} ) O) 2 -H _{, - (CH 2 CH (CH} 3) O) 3 -H,
_{- (CH 2 CH (CH 3} ) O) 4 -H, - (CH 2 CH (CH 3) O) 5 -H,
_{- (CH 2 CH (CH 3} ) O) 8 -H, - (CH 2 CH (CH 3) O) 10 -H,
_{- (CH 2 CH (CH 3} ) O) 12 -H, - (CH 2 CH (CH 3) O) 16 -H,
_{- (CH 2 CH (CH 3} ) O) 20 -H, - (CH 2 CH (CH 3) O) 40 -H,
_{- (CH 2 CH (CH 3} ) O) 2 -CH 3, - (CH 2 CH (CH 3) O) 3 -CH 3,
_{- (CH 2 CH (CH 3} ) O) 4 -CH 3, - (CH 2 CH (CH 3) O) 5 -CH 3,
_{- (CH 2 CH (CH 3} ) O) 8 -CH 3, - (CH 2 CH (CH 3) O) 10 -CH 3,
_{- (CH 2 CH (CH 3} ) O) 12 -CH 3, - (CH 2 CH (CH 3) O) 16 -CH 3,
_{- (CH 2 CH (CH 3} ) O) 20 -CH 3, - (CH 2 CH (CH 3) O) 40 -CH 3,
_{- (CH 2 CH (CH 3} ) O) 2 -C 2 H 5, - (CH 2 CH (CH 3) O) 3 -C 2 H 5,
_{- (CH 2 CH (CH 3} ) O) 4 -C 2 H 5, - (CH 2 CH (CH 3) O) 8 -C 2 H 5,
_{- (CH 2 CH (CH 3} ) O) 12 -C 2 H 5, - (CH 2 CH (CH 3) O) 20 -C 2 H 5,
_{- (CH 2 CH (CH 3} ) O) 40 -C 2 H 5, - (CH 2 CH (CH 3) O) 2 -C 3 H 7,
_{- (CH 2 CH (CH 3} ) O) 2 -C 4 H 9, - (CH 2 CH (CH 3) O) 4 -C 4 H 9,
_{- (CH 2 CH (CH 3} ) O) 8 -C 4 H 9, - (CH 2 CH (CH 3) O) 2 -C 5 H 11,
_{- (CH 2 CH (CH 3} ) O) 2 -C 6 H 13, - (CH 2 CH (CH 3) O) 4 -C 6 H 13,
_{- (CH 2 CH (CH 3} ) O) 8 -C 6 H 13, - (CH 2 CH (CH 3) O) 2 -C 6 H 5,
_{- (CH 2 CH (CH 3} ) O) 4 -C 6 H 5, - (CH 2 CH (CH 3) O) 8 -C 6 H 5,
_{- (CH 2 CH (CH 3} ) O) 2 - (c-) C 6 H 11, - (CH 2 CH (CH 3) O) 4 - (c-) C 6 H 11,
_{- (CH 2 CH (CH 3} ) O) 8 - (c-) C 6 H 11, - (CH 2 CH (CH 3) O) 2 -C 7 H 15,
_{- (CH 2 CH (CH 3} ) O) 2 -CH 2 C 6 H 5, - (CH 2 CH (CH 3) O) 4 -CH 2 C 6 H 5,
_{- (CH 2 CH (CH 3} ) O) 8 -CH 2 C 6 H 5,
_{- (CH 2 CH (CH 3} ) O) 2 -C 8 H 17, - (CH 2 CH (CH 3) O) 4 -C 8 H 17,
_{- (CH 2 CH (CH 3} ) O) 8 -C 8 H 17, - (CH 2 CH (CH 3) O) 2 -C 9 H 19,
_{- (CH 2 CH (CH 3} ) O) 2 -C 10 H 21, - (CH 2 CH (CH 3) O) 4 -C 10 H 21,
_{- (CH 2 CH (CH 3} ) O) 2 -C 12 H 25, - (CH 2 CH (CH 3) O) 4 -C 12 H 25,
_{- (CH 2 CH (CH 3} ) O) 2 -C 14 H 29, - (CH 2 CH (CH 3) O) 4 -C 14 H 29,
_{- (CH 2 CH (CH 3} ) O) 2 -C 16 H 33, - (CH 2 CH (CH 3) O) 4 -C 16 H 33,
_{- (CH 2 CH (CH 3} ) O) 2 -C 18 H 37, - (CH 2 CH (CH 3) O) 4 -C 18 H 37,
_{- (CH 2 CH (CH 3} ) O) 2 -C 20 H 41, - (CH 2 CH (CH 3) O) 4 -C 20 H 41,
_{- (CH 2 CH (CH 3} ) O) 2 -C 22 H 45, - (CH 2 CH (CH 3) O) 4 -C 22 H 45,

_{- (CH (CH 3) CH} 2 O) 2 -H _{, - (CH (CH 3)} CH 2 O) 3 -H,
_{- (CH (CH 3) CH} 2 O) 4 -H, - (CH (CH 3) CH 2 O) 5 -H,
_{- (CH (CH 3) CH} 2 O) 8 -H, - (CH (CH 3) CH 2 O) 10 -H,
_{- (CH (CH 3) CH} 2 O) 12 -H, - (CH (CH 3) CH 2 O) 16 -H,
_{- (CH (CH 3) CH} 2 O) 20 -H, - (CH (CH 3) CH 2 O) 40 -H,
_{- (CH (CH 3) CH} 2 O) 2 -CH 3, - (CH (CH 3) CH 2 O) 3 -CH 3,
_{- (CH (CH 3) CH} 2 O) 4 -CH 3, - (CH (CH 3) CH 2 O) 5 -CH 3,
_{- (CH (CH 3) CH} 2 O) 8 -CH 3, - (CH (CH 3) CH 2 O) 10 -CH 3,
_{- (CH (CH 3) CH} 2 O) 12 -CH 3, - (CH (CH 3) CH 2 O) 16 -CH 3,
_{- (CH (CH 3) CH} 2 O) 20 -CH 3, - (CH (CH 3) CH 2 O) 40 -CH 3,
_{- (CH (CH 3) CH} 2 O) 2 -C 2 H 5, - (CH (CH 3) CH 2 O) 3 -C 2 H 5,
_{- (CH (CH 3) CH} 2 O) 4 -C 2 H 5, - (CH (CH 3) CH 2 O) 8 -C 2 H 5,
_{- (CH (CH 3) CH} 2 O) 12 -C 2 H 5, - (CH (CH 3) CH 2 O) 20 -C 2 H 5,
_{- (CH (CH 3) CH} 2 O) 40 -C 2 H 5, - (CH (CH 3) CH 2 O) 2 -C 3 H 7,
_{- (CH (CH 3) CH} 2 O) 2 -C 4 H 9, - (CH (CH 3) CH 2 O) 4 -C 4 H 9,
_{- (CH (CH 3) CH} 2 O) 8 -C 4 H 9, - (CH (CH 3) CH 2 O) 2 -C 5 H 11,
_{- (CH (CH 3) CH} 2 O) 2 -C 6 H 13, - (CH (CH 3) CH 2 O) 4 -C 6 H 13,
_{- (CH (CH 3) CH} 2 O) 8 -C 6 H 13, - (CH (CH 3) CH 2 O) 2 -C 6 H 5,
_{- (CH (CH 3) CH} 2 O) 4 -C 6 H 5, - (CH (CH 3) CH 2 O) 8 -C 6 H 5,
_{- (CH (CH 3) CH} 2 O) 2 - (c-) C 6 H 11, - (CH (CH 3) CH 2 O) 4 - (c-) C 6 H 11,
_{- (CH (CH 3) CH} 2 O) 8 - (c-) C 6 H 11,
_{- (CH (CH 3) CH} 2 O) 2 -C 7 H 15, - (CH (CH 3) CH 2 O) 2 -CH 2 C 6 H 5,
_{- (CH (CH 3) CH} 2 O) 4 -CH 2 C 6 H 5, - (CH (CH 3) CH 2 O) 8 -CH 2 C 6 H 5,
_{- (CH (CH 3) CH} 2 O) 2 -C 8 H 17, - (CH (CH 3) CH 2 O) 4 -C 8 H 17,
_{- (CH (CH 3) CH} 2 O) 8 -C 8 H 17, - (CH (CH 3) CH 2 O) 2 -C 9 H 19,
_{- (CH (CH 3) CH} 2 O) 2 -C 10 H 21, - (CH (CH 3) CH 2 O) 4 -C 10 H 21,
_{- (CH (CH 3) CH} 2 O) 2 -C 12 H 25, - (CH (CH 3) CH 2 O) 4 -C 12 H 25,
_{- (CH (CH 3) CH} 2 O) 2 -C 14 H 29, - (CH (CH 3) CH 2 O) 4 -C 14 H 29,
_{- (CH (CH 3) CH} 2 O) 2 -C 16 H 33, - (CH (CH 3) CH 2 O) 4 -C 16 H 33,
_{- (CH (CH 3) CH} 2 O) 2 -C 18 H 37, - (CH (CH 3) CH 2 O) 4 -C 18 H 37,
_{- (CH (CH 3) CH} 2 O) 2 -C 20 H 41, - (CH (CH 3) CH 2 O) 4 -C 20 H 41,
_{- (CH (CH 3) CH} 2 O) 2 -C 22 H 45, - (CH (CH 3) CH 2 O) 4 -C 22 H 45,

_{- (CH 2 CH 2 O)} 2 -CH = CH 2, - (CH 2 CH 2 O) 4 -CH = CH 2
_{- (CH 2 CH 2 O)} 2 -CH 2 CH = CH 2, - (CH 2 CH 2 O) 4 -CH 2 CH = CH 2
_{- (CH 2 CH 2 O)} 2 - (C = O) CH 3, - (CH 2 CH 2 O) 4 - (C = O) CH 3
_{- (CH 2 CH 2 O)} 2 - (C = O) C 6 H 5, - (CH 2 CH 2 O) 4 - (C = O) C 6 H 5
_{- (CH 2 CH 2 O)} 2 - (C = O) C 6 H 4 (4-CH 3)
_{- (CH 2 CH 2 O)} 4 - (C = O) C 6 H 4 (4-CH 3)
_{- (CH 2 CH 2 O)} 2 - (C = O) C 6 H 4 (4-OCH 3)
_{- (CH 2 CH 2 O)} 4 - (C = O) C 6 H 4 (4-OCH 3)
_{- (CH 2 CH 2 O)} 2 - (C = O) C 6 H 4 (4-Cl)
_{- (CH 2 CH 2 O)} 4 - (C = O) C 6 H 4 (4-Cl)
_{- (CH 2 CH 2 O)} 2 - (C = O) CH = CH 2
_{- (CH 2 CH 2 O)} 4 - (C = O) CH = CH 2
_{- (CH 2 CH 2 O)} 2 - (C = O) C (CH 3) = CH 2
_{- (CH 2 CH 2 O)} 4 - (C = O) C (CH 3) = CH 2
_{- (CH 2 CH 2 O)} 2 - (C = O) OC 6 H 5, - (CH 2 CH 2 O) 4 - (C = O) OC 6 H 5
_{- (CH 2 CH 2 O)} 2 - (C = O) NH 2, - (CH 2 CH 2 O) 4 - (C = O) NH 2
_{- (CH 2 CH 2 O)} 2 - (C = O) NHCH 3, - (CH 2 CH 2 O) 4 - (C = O) NHCH 3
_{- (CH 2 CH 2 O)} 2 - (C = O) NHC 6 H 5, - (CH 2 CH 2 O) 4 - (C = O) NHC 6 H 5
_{- (CH 2 CH 2 O)} 2 - (C = O) N (CH 3) 2, - (CH 2 CH 2 O) 4 - (C = O) N (CH 3) 2
_{- (CH 2 CH 2 O)} 2 - (C = O) NH (CH 2) 2 O (C = O) CH = CH 2
_{- (CH 2 CH 2 O)} 4 - (C = O) NH (CH 2) 2 O (C = O) CH = CH 2
_{- (CH 2 CH 2 O)} 2 - (C = O) NH (CH 2) 2 O (C = O) C (CH 3) = CH 2
_{- (CH 2 CH 2 O)} 4 - (C = O) NH (CH 2) 2 O (C = O) C (CH 3) = CH 2
_{- (CH 2 CH 2 O)} 2 -SO 3 H _{, - (CH 2 CH 2 O} ) 2 -SO 3 Na
_{- (CH 2 CH 2 O)} 4 -SO 3 Na _{, - (CH 2 CH 2 O} ) 2 -SO 3 K
_{- (CH 2 CH 2 O)} 2 - (CH 2) 2 SO 3 Na, - (CH 2 CH 2 O) 4 - (CH 2) 2 SO 3 Na
_{- (CH 2 CH 2 O)} 2 - (CH 2) 2 SO 3 K _{, - (CH 2 CH 2 O} ) 2 - (CH 2) 3 SO 3 Na
_{- (CH 2 CH 2 O)} 4 - (CH 2) 3 SO 3 Na, - (CH 2 CH 2 O) 2 - (CH 2) 3 SO 3 K
_{- (CH 2 CH 2 O)} 2 - (CH 2) 4 SO 3 Na, - (CH 2 CH 2 O) 4 - (CH 2) 4 SO 3 Na
_{- (CH 2 CH 2 O)} 2 - (CH 2) 4 SO 3 K _{, - (CH 2 CH 2 O} ) 2 - (CH 2) 4 SO 3 NH 4
_{- (CH 2 CH 2 O)} 2 - (C = O) (CH 2) 2 CO 2 Na
_{- (CH 2 CH 2 O)} 4 - (C = O) (CH 2) 2 CO 2 Na
_{- (CH 2 CH 2 O)} 2 - (C = O) (CH 2) 2 CO 2 H
_{- (CH 2 CH 2 O)} 4 - (C = O) (CH 2) 2 CO 2 H

_{- (CH 2 CH 2 CH 2} O) 2 -H , — (CH ₂ CH ₂ CH ₂ O) ₄ —H, — (CH ₂ CH ₂ CH ₂ O) ₂ —CH <sub>3
- (CH 2 CH 2 CH 2</sub> O) 4 -CH 3, - (CH 2 CH (OH) CH 2 O) 2 -H
_{- (CH 2 CH (OH)} CH 2 O) 4 -H, - (CH 2 CH (OH) CH 2 O) 2 -CH 3
_{- (CH 2 CH (OH)} CH 2 O) 4 -CH 3, - (CH 2 CH (OCOCH 3) CH 2 O) 2 -H
_{- (CH 2 CH (OCOCH 3} ) CH 2 O) 4 -H, - (CH 2 CH (OCOCH 3) CH 2 O) 2 -CH 3
_{- (CH 2 CH (OCOCH 3} ) CH 2 O) 4 -CH 3
_{- (CH 2 CH (OCOCH 2} CH 2 CO 2 H) CH 2 O) 2 -H
_{- (CH 2 CH (OCOCH 2} CH 2 CO 2 H) CH 2 O) 4 -H
_{- (CH 2 CH (OCOCH 2} CH 2 CO 2 H) CH 2 O) 2 -CH 3
_{- (CH 2 CH (OCOCH 2} CH 2 CO 2 H) CH 2 O) 4 -CH 3
_{- (CH 2 CH 2 O)} l (CH 2 CH (CH 3) O) m ((CH (CH 3) CH 2 O) n -H
(L, m, n are integers of 0 or more and 40 or less, and l + m + n is an integer of 2 or more and 40 or less. The order of each structural unit is arbitrary.)
_{- (CH 2 CH 2 O)} l (CH 2 CH (CH 3) O) m ((CH (CH 3) CH 2 O) n -CH 3
(L, m, n are integers of 0 or more and 40 or less, and l + m + n is an integer of 2 or more and 40 or less. The order of each structural unit is arbitrary.)

The polyoxyalkylene structure moiety of the present invention may be bonded directly to the ultraviolet absorbent of the present invention or may be bonded via a divalent or higher linking group. Linking groups include 0 to 60 carbon atoms, 0 to 10 nitrogen atoms, 0 to 50 oxygen atoms, 0 to 100 hydrogen atoms, and 0 to 20 It is preferable that it has at least one atom composed of up to 1 sulfur atom and 0 to 20 phosphorus atoms.
More specifically, examples of the linking group include the following divalent groups or divalent or higher valent composite linkage groups formed by appropriately combining them. _{Wherein, R 1, R 2, R} 3 and _{R 4} represents a hydrogen atom or a substituent. When R ₁ , R ₂ , and R ₃ are substituents, groups represented by R ₁₀₁ and R ₁₀₂ in the general formula (A) can be given as preferred examples. When R ₄ is a substituent, a group represented by R ₁₀₃ in formula (A) can be given as a preferred example.

  Examples of the composite linking group include the following. These may be further combined. When the linking group is asymmetric, any of the bondable end portions may be bonded to the partial structure represented by the general formula (A) of the present invention.

  The content of the ultraviolet absorbent of the present invention in the image recording layer is preferably 0.001 to 30% by mass of the solid content of the image recording layer. More preferably, it is 0.01-10 mass%, Most preferably, it is 0.05-7 mass%. Within the range of this addition amount, the handleability under a mercury lamp, which is the effect of the present invention, is excellent, and good on-press developability can be exhibited. Although the detailed mechanism by which the compound of the present invention exhibits the above effects is not clear, having a polyalkyleneoxy structure makes it possible to achieve both uniform dispersibility in the photosensitive layer and permeability of dampening water during printing. It is estimated that The ultraviolet absorber of the present invention may be used alone or in combination of two or more.

<Compound of general formula (1)>
The compound of the general formula (1) will be described in detail.

In General Formula (1), R _{11 to} R ₁₈ each independently represent a hydrogen atom or a substituent. However, at least one of the groups represented by R _{11 to} R ₁₈ represents a group having a polyoxyalkylene structure.

R _{11 to} R ₁₈ will be described in detail. R _{11 to} R ₁₈ each independently represents a hydrogen atom or a substituent. When R _{11 to} R ₁₈ represent a substituent other than a group having a polyoxyalkylene structure, examples of the substituent include an alkyl group having 1 to 40 carbon atoms (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, tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2- An ethylhexyl group, a 2-methylhexyl group, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-norbornyl group, a benzyl group, an allyl group, and the like, an alkenyl group having 2 to 40 carbon atoms (a vinyl group, a 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group, 1-cyclohexene Senyl group, etc.), C2-C40 alkynyl groups (ethynyl group, 1-propynyl group, 1-butynyl group, 1-octynyl group, etc.), C6-C40 aryl groups (phenyl group, 2-methylphenyl) Group, 3-methylphenyl group, 4-methylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 2-methoxyphenyl group, 4-methoxyphenyl group, 2-chlorophenyl group, 4 -Chlorophenyl group, 1-naphthyl group, 2-naphthyl group, etc.), heterocyclic group, halogen atom (-F, -Br, -Cl, -I), hydroxy group, alkoxy group, aryloxy group, mercapto group, alkylthio group , Arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N Arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy Group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino Group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group N-alkylureido group, N-arylureido group, N′-al Kill-N-alkylureido group, N′-alkyl-N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′- Aryl-N-alkylureido group, N′-aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′- Alkyl-N′-aryl-N-alkylureido 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-ary Xoxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group, alkoxycarbonyl group, aryloxycarbonyl group, N-alkylaminocarbonyl group, N, N-dialkylaminocarbonyl group, N-arylaminocarbonyl group N, N-diarylaminocarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group Alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group, alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-al Killsulfinamoyl 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 Famoyl group and its conjugate base group, N-alkylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (alkyl)) and its conjugate base group, N-arylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (aryl)) ) And its conjugate 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 ), a hydroxysilyl group (—Si (OH) ₃ ) and its conjugate base group, a phosphono group (—PO ₃ H ₂ ) and its conjugate base group, a dialkylphosphono group (—PO ₃ (alkyl) ₂ ), Diarylphosphono group (—PO ₃ (aryl) ₂ ), alkylarylphosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group , monoarylphosphono group _(-PO 3 H (aryl)) and its conjugated base group, a phosphonooxy group (-OP ₃ H ₂₎ and its conjugated base group, a dialkyl phosphono group _{(-OPO 3 (alkyl) 2)} , diaryl phosphono group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphono 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, A cyano group, a nitro group, a dialkylboryl group (—B (alkyl) ₂ ), a diarylboryl group (—B (aryl) ₂ ), an alkylarylboryl group (—B (alkyl) (aryl)), a dihydroxyboryl group (— B (OH) ₂ ) and its conjugate base group, alkylhydroxyboryl group (—B (alkyl) (OH)) And a conjugated base group thereof, an arylhydroxyboryl group (—B (aryl) (OH)) and a conjugated base group thereof.
The above groups may be further substituted, and examples of the substituent include R _{11 to} R ₁₈ described above.

Preferably, a hydrogen atom, an alkyl group, a halogen atom (—F, —Br, —Cl, —I), a hydroxy group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, a carbamoyloxy group, N— Alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, sulfo group (—SO ₃ H) and Its conjugate base group, carboxy group and its conjugate base group, alkylsulfoxy group, arylsulfoxy group, phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group, dialkylphosphonooxy group (—OPO ₃ (alkyl)) ₂ ), a diarylphosphonooxy group (-OP O ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group, monoarylphospho And a nooxy group (—OPO ₃ H (aryl)) and its conjugate base group.
More preferably, a hydrogen atom, an alkyl group, a halogen atom (—F, —Br, —Cl, —I), a hydroxy group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, a carbamoyloxy group, N -Alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group Group, sulfo group (—SO ₃ H) and its conjugated base group, carboxy group and its conjugated base group, and the like.
Particularly preferably, a hydrogen atom, an alkyl group, a halogen atom (—F, —Br, —Cl, —I), a hydroxy group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, a carbamoyloxy group, N - alkylcarbamoyl group, N- arylcarbamoyloxy group, a sulfo group (-SO 3 _H) and its conjugated base group, a carboxy group and a conjugated base group.

  Although the preferable example of a compound represented by General formula (1) below is given, this invention is not limited to these.

<Compound of general formula (2)>
The compound of the general formula (2) will be described in detail.

In the general formula (2), X _{21 to} X ₂₃ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a heterocyclic group. However, at least one of X _{21 to} X ₂₃ represents a group represented by the general formula (3), and at least one of X _{21 to} X ₂₃ and R _{31 to} R ₃₄ has a polyoxyalkylene structure. Represents a group having.

_Wherein, R 31 _{to R 34} each independently represent a hydrogen atom or a substituent.

When X _{21 to} X ₂₃ represent a group other than a group represented by the general formula (3) or a group having a polyoxyalkylene structure, examples of the substituent include an alkyl group having 1 to 40 carbon atoms ( Methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, Neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group, benzyl group, allyl group, etc.), 6 to 6 carbon atoms 40 aryl groups (phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 2-methoxyphenyl group, 4-methoxyphenyl group, 2-chlorophenyl group, 4-chlorophenyl group, 1-naphthyl group, 2-naphthyl group, etc. ), An alkoxy group having 1 to 40 carbon atoms (methoxy group, ethoxy group, propyloxy group, butyloxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, 2-propyloxy group) Group, isobutyloxy group, sec-butyloxy group, tert-butyloxy group, isopentyloxy group, neopentyloxy group, 1-methylbutyloxy group, isohexyloxy group, 2-ethylhexyloxy group, 2-methylhexyloxy group , Cyclopentyloxy group, cyclohexyl Oxy group, 1-adamantyloxy group, 2-norbornyloxy group, benzyloxy group, allyloxy group, etc.), aryloxy group having 6 to 40 carbon atoms (phenoxy group, 2-methylphenoxy group, 3-methylphenoxy group) 4-methylphenoxy group, 3,5-dimethylphenoxy group, 2,4,6-trimethylphenoxy group, 2-methoxyphenoxy group, 4-methoxyphenoxy group, 2-chlorophenoxy group, 4-chlorophenoxy group, 1 -Naphthyloxy group, 2-naphthyloxy group, etc.) or heterocyclic groups (2-pyridyl group, 4-pyridyl group, morpholinyl group) and the like.
The above groups may be further substituted, and examples of the substituent include R _{11 to} R ₁₈ described above.

  Particularly preferably, an alkyl group having 1 to 10 carbon atoms (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, 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 Benzyl group, allyl group, etc.), aryl group having 6 to 20 carbon atoms (phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3,5-dimethylphenyl group, 2,4 , 6-trimethylphenyl group, 2-methoxyphenyl group, 4-methoxyphenyl group, 2- Rorofeniru group, 4-chlorophenyl group, 1-naphthyl group, 2-naphthyl group.

The group represented by the general formula (3) will be described. _Wherein, R 31 _{to R 34} each independently represent a hydrogen atom or a substituent. When R _{31 to} R ₃₄ represent a substituent, examples of the substituent include a group having a polyoxyalkylene structure and preferred examples of the group represented by R _{11 to} R ₁₈ in the general formula (1). it can.

  Although the preferable example of a compound represented by General formula (2) below is given, this invention is not limited to these.

<Compound of general formula (4)>
The compound of the general formula (4) will be described in detail.

In General Formula (4), R _{40 to} R ₄₉ each independently represent a hydrogen atom or a substituent. However, at least one of the groups represented by R _{40 to} R ₄₉ represents a group having a polyoxyalkylene structure. When R _{40 to} R ₄₉ represent a substituent other than a group having a polyoxyalkylene structure, examples of the substituent include examples of the substituent represented by R _{11 to} R ₁₈ in the general formula (1). Can do. At least one of R ₄₀ , R ₄₁ , R ₄₅ and R ₄₆ is preferably a hydroxy group. X ₄₁ represents —CO— or —COO—.
Although the preferable example of a compound represented by General formula (4) below is given, this invention is not limited to these.

<Compound of general formula (5)>
The compound of the general formula (5) will be described in detail.

In the general formula _{(5), R} 51 ~R ₅₅ independently represents a hydrogen atom or a substituent. When R _{51 to} R ₅₅ represent a substituent other than a group having a polyoxyalkylene structure, examples of the substituent include examples of the substituent represented by R _{11 to} R ₁₈ in the general formula (1). Can do.
X ₅₁ represents a hydrogen atom or an alkyl group, and Y ₅₁ and Y ₅₂ each independently represent a hydrogen atom, a cyano group, —COOZ ₅₁ , —CONHZ ₅₁ , —COZ ₅₁ , —SO ₂ Z ₅₁ or —SO ₂ NHZ. ₅₁ , and Z ₅₁ represents a hydrogen atom, an alkyl group, or an aryl group. Y ₅₁ and Y ₅₂ may be connected to each other to form a ring.
As a preferred example when X ₅₁ represents an alkyl group and Z ₅₁ represents an alkyl group or an aryl group, the substituent represented by R _{11 to} R ₁₈ in the general formula (1) is an alkyl group. Or a preferable example when an aryl group is represented can be given.
At least one of R _{51 to} R ₅₅ , Y ₅₁ and Y ₅₂ represents a group having a polyoxyalkylene structure.
Although the preferable example of a compound represented by General formula (5) below is given, this invention is not limited to these.

<Compound of general formula (6)>
The compound of the general formula (6) will be described in detail.

In General Formula (6), R ₆₁ and R ₆₂ each independently represent a hydrogen atom, an alkyl group, or an aryl group. As a preferable example when R ₆₁ and R ₆₂ represent an alkyl group or an aryl group, a preferable example when the substituent represented by R _{11 to} R ₁₈ in the general formula (1) represents an alkyl group or an aryl group. Can be mentioned. R ₆₁ and R ₆₂ may be connected to each other to form a 5- or 6-membered ring. Y ₆₁ and Y ₆₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). At least one of R ₆₁ , R ₆₂ , Y ₆₁ and Y ₆₂ represents a group having a polyoxyalkylene structure.
Although the preferable example of a compound represented by General formula (6) below is given, this invention is not limited to these.

<Compound of general formula (7)>
The compound of the general formula (7) will be described in detail.

In the general formula _{(7), R} 70 ~R ₇₉ independently represents a hydrogen atom or a substituent. When R _{70 to} R ₇₉ represent a substituent other than a group having a polyoxyalkylene structure, examples of the substituent include examples of the substituent represented by R _{11 to} R ₁₈ in the general formula (1). Can do. X ₇₁ and X ₇₂ each independently represent a hydrogen atom, an alkyl group or an aryl group. Preferred examples of when X ₇₁ and X ₇₂ represents an alkyl group or an aryl group, a preferred example when the substituents represented by R ₁₁ to R ₁₈ of the general formula (1) represents an alkyl group or an aryl group Can be mentioned. At least one of R _{70 to} R ₇₉ , X ₇₁ and X ₇₂ represents a group having a polyoxyalkylene structure.

  Although the preferable example of a compound represented by General formula (7) below is given, this invention is not limited to these.

<Compound of general formula (8)>
The compound of the general formula (8) will be described in detail.

In general formula (8), R < ₈₁ > -R < ₈₄ > represents a hydrogen atom or a substituent each independently. When R _{81 to} R ₈₄ represent a substituent other than a group having a polyoxyalkylene structure, examples of the substituent include examples of the substituent represented by R _{11 to} R ₁₈ in the general formula (1). Can do. L ₈₁ represents a single bond or a double bond. However, when L ₈₁ represents a double bond, R ₈₁ and R ₈₄ are not present. R ₈₂ and R ₈₃ may be bonded to each other to form a ring. X ₈₁ represents an alkyl group or an aryl group, and preferred examples include preferred examples when the substituent represented by R _{11 to} R ₁₈ in the general formula (1) represents an alkyl group or an aryl group. .
Z ₈₁ represents an oxygen atom, a sulfur atom, —N (R ₈₅ ) — or —C (R ₈₆ ) (R ₈₇ ) —, R ₈₅ represents an alkyl group or an aryl group, and R ₈₆ and R ₈₇ each represent Independently, it represents a hydrogen atom or an alkyl group, and R ₈₆ and R ₈₇ may be bonded to each other to form a ring. As a preferable example when R ₈₅ , R ₈₆ and R ₈₇ represent an alkyl group or an aryl group, a substituent represented by R _{11 to} R ₁₈ in the general formula (1) represents an alkyl group or an aryl group. Preferred examples can be given.
Y ₈₁ and Y ₈₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R _{81 to} R ₈₄ , X ₈₁ , Y ₈₁ , Y ₈₂ and Z ₈₁ represents a group having a polyoxyalkylene structure. n represents 0 or 1.

  Although the preferable example of a compound represented by General formula (8) below is given, this invention is not limited to these.

<Compound of general formula (9)>
The compound of the general formula (9) will be described in detail.

In General Formula (9), R _{91 to} R ₉₄ each independently represent a hydrogen atom or a substituent. When R _{91 to} R ₉₄ represent a substituent other than a group having a polyoxyalkylene structure, examples of the substituent include examples of substituents represented by R _{11 to} R ₁₈ in the general formula (1). Can do. Y ₉₁ and Y ₉₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R _{91 to} R ₉₄ , Y ₉₁ and Y ₉₂ represents a group having a polyoxyalkylene structure.

  Although the preferable example of a compound represented by General formula (9) below is given, this invention is not limited to these.

  The ultraviolet absorbent according to the present invention is synthesized by referring to Japanese Patent No. 3422090, Japanese Patent Application Laid-Open No. 2009-96974, Japanese Patent Application Laid-Open No. 2009-96973, and methods described in these cited references.

(Image recording layer)
Next, constituent components of the image recording layer other than the ultraviolet absorbent according to the present invention will be described in detail.
The image recording layer used in the present invention forms a lithographic printing plate precursor capable of forming an image by supplying printing ink and fountain solution on a printing machine after exposure to remove an unexposed portion. And A typical embodiment of the image recording layer further includes (A) an infrared absorber, (B) a radical polymerization initiator, and (C) a polymerizable compound. A polymer compound containing an oxyalkylene structure is contained. It is also preferable to have an oxygen blocking layer above the image recording layer.
Below, each component which can be contained in an image recording layer is demonstrated one by one.

(A) Infrared Absorber The infrared absorber has a function of converting absorbed infrared light into heat and a function of being excited by infrared light to transfer electrons and / or energy to a radical polymerization initiator described later. The infrared absorbent preferably used in the present invention is a dye having an absorption maximum at a wavelength of 760 to 1200 nm.

As the infrared absorber, compounds described in paragraph numbers [0058] to [0087] of JP-A-2008-195018 can be used.
Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Particularly preferred examples include cyanine dyes represented by the following general formula (a).

In general formula (a), X ¹ represents a hydrogen atom, a halogen atom, —N (R ⁹ ) (R ¹⁰ ), —X ² -L ¹ or a group shown below. Here, R ⁹ and R ¹⁰ may be the same or different, and may have a substituent, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. Represents a hydrogen atom, and R ⁹ and R ¹⁰ may be bonded to each other to form a ring. Of these, a phenyl group is preferred. X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or a hydrocarbon group having 1 to 12 carbon atoms including a hetero atom. . In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. In the group shown below, Xa ^- has Za described later ^- is defined as for, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom .

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

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

  Specific examples of the cyanine dye represented by the general formula (a) that can be suitably used in the present invention include paragraph numbers [0017] to [0019] of JP-A No. 2001-133969 and JP-A No. 2002-023360. Examples thereof include those described in paragraph Nos. [0012] to [0021] of Japanese Patent Publication No. and paragraph Nos. [0012] to [0037] of JP-A No. 2002-040638.

  Moreover, these (A) infrared absorbers may use only 1 type, may use 2 or more types together, and may use infrared absorbers other than infrared absorbers, such as a pigment, together. As the pigment, compounds described in JP 2008-195018 A [0072] to [0076] are preferable.

  The content of the infrared absorber in the image recording layer in the present invention is preferably 0.1 to 10.0% by mass, more preferably 0.5 to 5.0% by mass of the total solid content of the image recording layer. .

(B) Radical polymerization initiator (B) As the radical polymerization initiator used in the present invention, (C) a compound that initiates and accelerates polymerization of a polymerizable compound is shown. As the radical polymerization initiator that can be used in the present invention, a known thermal polymerization initiator, a compound having a bond with a small bond dissociation energy, a photopolymerization initiator, and the like can be used.
Examples of the radical polymerization initiator in the present invention include (a) an organic halide, (b) a carbonyl compound, (c) an azo compound, (d) an organic peroxide, (e) a metallocene compound, and (f) an azide compound. (G) hexaarylbiimidazole compound, (h) organic borate compound, (i) disulfone compound, (j) oxime ester compound, (k) onium salt compound.

  (A) As the organic halide, compounds described in paragraph numbers [0022] to [0023] of JP-A-2008-195018 are preferable.

  (B) As the carbonyl compound, compounds described in paragraph [0024] of JP-A-2008-195018 are preferable.

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

  (D) As the organic peroxide, for example, compounds described in paragraph [0025] of JP-A-2008-195018 are preferable.

  As the (e) metallocene compound, for example, the compound described in paragraph [0026] of JP-A-2008-195018 is preferable.

(F) Examples of the azide compound include 2,6-bis (4-azidobenzylidene) -4-methylcyclohexanone.
(G) As the hexaarylbiimidazole compound, for example, a compound described in paragraph [0027] of JP-A-2008-195018 is preferable.

  (H) As the organic borate compound, for example, a compound described in paragraph [0028] of JP-A-2008-195018 is preferable.

  (I) Examples of the disulfone compound include compounds described in JP-A Nos. 61-166544 and 2002-328465.

  (J) As the oxime ester compound, for example, compounds described in paragraph numbers [0028] to [0030] of JP-A-2008-195018 are preferable.

  (K) Examples of the onium salt compounds include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Bal et al, Polymer, 21, 423 (1980), ammonium salts described in US Pat. No. 4,069,055, JP-A-4-365049, etc., US Pat. No. 4,069 , 055, 4,069,056, phosphonium salts described in European Patent Nos. 104,143, U.S. Pat. Nos. 339,049, 410,201, U.S. Patent Application Publication No. 2008 No. 0311520, iodonium salts described in JP-A-2-150848, JP-A-2-296514, JP-A-2008-195018, European Patent Nos. 370,693 and 390,214. 233,567, 297,443, 297,442, U.S. Pat.Nos. 4,933,377, 161,811 410,201, 339,049, 4,760,013, 4,734,444, 2,833,827, German Patent 2,904,626, 3 , 604, 580, and 3,604, 581, the sulfonium salts described in the respective specifications; V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), and onium salts such as azinium salts described in JP-A-2008-195018.

  Of these, more preferred are onium salts, especially iodonium salts, sulfonium salts and azinium salts. Although the specific example of these compounds is shown below, it is not limited to this.

  As an example of the iodonium salt, a diphenyl iodonium salt is preferable, and a diphenyl iodonium salt substituted with an electron donating group such as an alkyl group or an alkoxyl group is particularly preferable, and an asymmetric diphenyl iodonium salt is more preferable. Specific examples include diphenyliodonium = hexafluorophosphate, 4-methoxyphenyl-4- (2-methylpropyl) phenyliodonium = hexafluorophosphate, 4- (2-methylpropyl) phenyl-p-tolyliodonium = hexa. Fluorophosphate, 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium = tetrafluoroborate, 4-octyloxy Phenyl-2,4,6-trimethoxyphenyliodonium = 1-perfluorobutanesulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium = hexafluorophosphate, bis ( -t- butylphenyl) iodonium tetraphenylborate and the like.

  Examples of sulfonium salts include triphenylsulfonium = hexafluorophosphate, triphenylsulfonium = benzoylformate, bis (4-chlorophenyl) phenylsulfonium = benzoylformate, bis (4-chlorophenyl) -4-methylphenylsulfonium = Examples include tetrafluoroborate and tris (4-chlorophenyl) sulfonium = 3,5-bis (methoxycarbonyl) benzenesulfonate.

  Examples of azinium salts include 1-cyclohexylmethyloxypyridinium = hexafluorophosphate, 1-cyclohexyloxy-4-phenylpyridinium = hexafluorophosphate, 1-ethoxy-4-phenylpyridinium = hexafluorophosphate, 1-cyclohexyl (2-ethylhexyloxy) -4-phenylpyridinium = hexafluorophosphate, 4-chloro-1-cyclohexylmethyloxypyridinium = hexafluorophosphate, 1-ethoxy-4-cyanopyridinium = hexafluorophosphate, 3,4 -Dichloro-1- (2-ethylhexyloxy) pyridinium = hexafluorophosphate, 1-benzyloxy-4-phenylpyridinium = hexafluorophosphate, 1-phenethylo Ci-4-phenylpyridinium = hexafluorophosphate, 1- (2-ethylhexyloxy) -4-phenylpyridinium = p-toluenesulfonate, 1- (2-ethylhexyloxy) -4-phenylpyridinium = perfluorobutanesulfonate 1- (2-ethylhexyloxy) -4-phenylpyridinium bromide, 1- (2-ethylhexyloxy) -4-phenylpyridinium tetrafluoroborate.

  The radical polymerization initiator is preferably from 0.1 to 50 mass%, more preferably from 0.5 to 30 mass%, particularly preferably from 0.8 to 20 mass%, based on the total solid content constituting the image recording layer. Can be added. Within this range, good sensitivity and good stain resistance of the non-image area during printing can be obtained.

(C) Polymerizable compound The polymerizable compound (C) that can be used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and has at least one terminal ethylenically unsaturated bond. Preferably, it is selected from compounds having two or more. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and their (co) polymers.

  Specific examples include the compounds described in JP-A-2008-195018, paragraphs [0089] to [0098]. Among them, preferred are esters of aliphatic polyhydric alcohol compounds and unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and the like). Another preferred polymerizable compound is a polymerizable compound having an isocyanuric acid structure described in JP-A-2005-329708.

  Among them, tris (acryloyloxyethyl) isocyanurate, bis (acryloyloxyethyl) hydroxyethyl isocyanurate, etc. are excellent in the balance between the hydrophilicity involved in on-press developability and the polymerization ability involved in printing durability. Isocyanuric acid ethylene oxide modified acrylates are particularly preferred.

  In the present invention, the polymerizable compound (C) is preferably used in the range of 5 to 80% by mass, more preferably 15 to 75% by mass, based on the total solid content of the image recording layer.

(Other ingredients)
The image recording layer in the invention may further contain other components as required.

(E) Polymer compound
The image recording layer of the present invention may contain a polymer compound in order to impart on-press developability. In particular, a polymer having a polyoxyalkylene structure (polyoxyalkylene group) is preferable. A polymer having a polyoxyalkylene group, particularly a polymer compound having a polyoxyalkylene group in the side chain, does not have a specific shape such as a particle shape even if it is contained in the form of fine particles in the image recording layer, The image recording layer may be contained as a medium for dissolving or bonding various materials (hereinafter referred to as a binder in the present invention).
In any case, it is considered that by introducing a polyoxyalkylene group into such a polymer compound in the side chain, the compatibility with the ultraviolet absorber having a polyoxyalkylene structure is improved, and the polymer compound effectively acts as an ultraviolet absorber. .

(E-1) Polymer fine particles In the present invention, polymer fine particles can be used in order to improve the on-press developability. The polymer fine particles in the present invention are preferably at least one fine particle selected from hydrophobic thermoplastic polymer fine particles, heat-reactive polymer fine particles, microcapsules enclosing a hydrophobic compound, and crosslinked polymer fine particles (microgel).
In the present invention, the polymer fine particles preferably have a polyoxyalkylene structure from the viewpoint of compatibility with the ultraviolet absorber. In particular, the oxyalkylene group is preferably an oxyethylene group, and is preferably a polyoxyethylene group having 12 to 250 repeating units of the oxyethylene group.

  Hydrophobic thermoplastic polymer fine particles refer to Research Disclosure No. 1 of January 1992. 333003, JP-A-9-123387, JP-A-9-131850, JP-A-9-171249, JP-A-9-171250 and European Patent No. 931647, etc. It means fine particles that become hydrophobized by fusing with heat generated during the process.

  Specific examples of the hydrophobic thermoplastic polymer fine particles include ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, and acrylate having a polyoxyalkylene structure. Or a homopolymer or copolymer of monomers such as methacrylate or mixtures thereof. Among these, a homopolymer or copolymer of a monomer selected from styrene, acrylonitrile, methyl methacrylate, and an acrylate or methacrylate having a polyoxyethylene structure is preferable. The fine polymer particles can be synthesized by a known method of emulsion polymerization or suspension polymerization of the above monomers.

The heat-reactive polymer fine particles include polymer fine particles having a heat-reactive group, and these mean fine particles that form a hydrophobized region by crosslinking due to a thermal reaction and a functional group change at that time. The thermoreactive group may be any functional group that performs a reaction as long as a chemical bond is formed, but an ethylenically unsaturated group that performs a radical polymerization reaction (for example, an acryloyl group, a methacryloyl group, a vinyl group, Allyl groups, etc.), cationically polymerizable groups (eg, vinyl groups, vinyloxy groups, etc.), isocyanate groups that perform addition reactions or their block bodies, epoxy groups, vinyloxy groups, and functional groups having active hydrogen atoms that are reaction partners thereof. A group (for example, an amino group, a hydroxy group, a carboxy group, etc.), a carboxy group that performs a condensation reaction, and a hydroxy group or amino group that is a reaction partner, an acid anhydride that performs a ring-opening addition reaction, and an amino group or hydroxy that is a reaction partner A group etc. can be mentioned as a suitable thing.
Introduction of the heat-reactive group functional group and the polyoxyalkylene structure into the polymer fine particles may be performed at the time of polymerization, or may be performed using a polymer reaction after the polymerization.

  As the microcapsules used in the present invention, for example, as described in JP-A Nos. 2001-277740 and 2001-277742, all or part of the constituent components of the image recording layer are encapsulated in the microcapsules. Is. The constituent components of the image recording layer can also be contained outside the microcapsules. Furthermore, it is preferable that the image recording layer containing the microcapsule includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule.

  In this invention, the aspect containing a crosslinked resin particle, ie, a microgel, may be sufficient. This microgel can contain a part of the components of the image recording layer in and / or on the surface thereof. In particular, the microgel has a reactive microgel by having (C) a polymerizable compound on the surface thereof. From the viewpoint of image formation sensitivity and printing durability, it is particularly preferable.

  The introduction of a polyoxyalkylene structure into a microcapsule or microgel is a known method such as a method of adding polyoxyalkylene monoalkyl ether to a component of interfacial polymerization using a polyfunctional isocyanate. It can be done as an application.

  The average particle size of the polymer fine particles is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is still more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, good resolution and stability over time can be obtained.

  The content of the polymer fine particles is preferably in the range of 5 to 90% by mass of the total solid content of the image recording layer.

(E-2) Binder polymer In the image recording layer of the present invention, a binder polymer can be used as a binder for each component of the image recording layer and for improving the film strength. As the binder polymer that can be used in the present invention, conventionally known binder polymers can be used without limitation, and polymers having film properties are preferred. Of these, acrylic resins, polyvinyl acetal resins, and polyurethane resins are preferable.
It is particularly preferable that the binder polymer has a polyoxyalkylene structure as a hydrophilic group from the viewpoint of improving the on-press developability. The polyoxyalkylene group is preferably a polyoxyethylene group, and is preferably a polyoxyethylene group having 2 to 8 repeating units of the oxyethylene group. Particularly preferred is an acrylic resin obtained by copolymerizing a monomer having a polyoxyethylene structure.

  In addition, in the binder polymer of the present invention, an oleophilic group such as an alkyl group, an aryl group, an aralkyl group, or an alkenyl group can be introduced in order to control the inking property. Specifically, a lipophilic group-containing monomer such as an alkyl methacrylate may be copolymerized.

  Among them, as a binder polymer suitable for the present invention, as described in JP-A-2008-195018, a crosslinkable functional group for improving the film strength of the image portion is a main chain or a side chain, preferably a side chain. Have the following. Crosslinking is formed between the polymer molecules by the crosslinkable group, and curing is accelerated.

  The crosslinkable functional group is preferably an ethylenically unsaturated group such as a (meth) acryl group, a vinyl group or an allyl group, or an epoxy group, and these groups can be introduced into the polymer by polymer reaction or copolymerization. . For example, a reaction between an acrylic polymer or polyurethane having a carboxy group in the side chain and polyurethane and glycidyl methacrylate, or a reaction between a polymer having an epoxy group and an ethylenically unsaturated group-containing carboxylic acid such as methacrylic acid can be used.

  The content of the crosslinkable group in the binder polymer is preferably 0.1 to 10.0 mmol, more preferably 1.0 to 7.0 mmol, and most preferably 2.0 to 5.5 mmol per 1 g of the binder polymer. .

The binder polymer can further have a hydrophilic group other than the polyoxyalkylene structure. Examples of other hydrophilic groups include a hydroxy group, a carboxy group, an amino group, an ammonium group, an amide group, a sulfo group, and a phosphoric acid group. The hydrophilic group contributes to imparting on-press developability to the image recording layer. In particular, the coexistence of the crosslinkable group and the hydrophilic group makes it possible to achieve both printing durability and developability.
In order to impart a hydrophilic group to the binder polymer, a monomer having a hydrophilic group may be copolymerized.

  Specific examples (1) to (11) of the binder polymer used in the present invention are shown below, but the present invention is not limited thereto.

  The binder polymer in the present invention preferably has a mass average molar mass (Mw) of 2000 or more, more preferably 5000 or more, and still more preferably 10,000 to 300,000.

  In the present invention, if necessary, hydrophilic polymers such as polyacrylic acid and polyvinyl alcohol described in JP-A-2008-195018 can be used. Further, a lipophilic binder polymer and a hydrophilic binder polymer can be used in combination.

  The content of the binder polymer is usually 5 to 90% by mass, preferably 5 to 80% by mass, and more preferably 10 to 70% by mass with respect to the total solid content of the image recording layer.

(F) Low molecular weight hydrophilic compound The image-recording layer in the invention may contain a low molecular weight hydrophilic compound in order to improve the on-press developability without reducing the printing durability.
As the low molecular weight hydrophilic compound, for example, as the water-soluble organic compound, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like glycols and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol and tris (2-hydroxyethyl) isocyanurate, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfones such as alkylsulfonic acid, toluenesulfonic acid and benzenesulfonic acid Acids and salts thereof, organic sulfamic acids such as alkylsulfamic acid and salts thereof, organic sulfuric acids such as alkylsulfuric acid and alkylethersulfuric acid and salts thereof, phenylphosphone Organic phosphonic acids and their salts etc., tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, organic carboxylic acids and salts thereof such as amino acids, betaines, and the like.

  Among these, in the present invention, it is preferable to contain at least one selected from the group consisting of polyols, organic sulfates, organic sulfonates, and betaines.

  Specific examples of organic sulfonates include alkyl sulfonates such as sodium n-butyl sulfonate, sodium n-hexyl sulfonate, sodium 2-ethylhexyl sulfonate, sodium cyclohexyl sulfonate, and sodium n-octyl sulfonate. Sodium 5,8,11-trioxapentadecane-1-sulfonate, sodium 5,8,11-trioxaheptadecane-1-sulfonate, 13-ethyl-5,8,11-trioxaheptadecane-1; Alkyl sulfonates containing ethylene oxide chains such as sodium sulfonate, 5,8,11,14-tetraoxatetradecosane-1-sodium sulfonate; sodium benzenesulfonate, sodium p-toluenesulfonate, p-hydroxy Benzenesulfo Acid sodium, sodium p-styrenesulfonate, sodium dimethyl-5-sulfonate isophthalate, sodium 1-naphthylsulfonate, sodium 4-hydroxynaphthylsulfonate, disodium 1,5-naphthalenedisulfonate, 1,3,6 -Aryl sulfonates such as trisodium naphthalene trisulfonate, and salts of alkyl polyoxyalkylene sulfoalkyl ethers. For example, sodium n-octyl (diethyleneoxy) sulfobutyl ether, 2-ethylhexyl (diethyleneoxy) sulfobutyl ether sodium, n-decyl (diethyleneoxy) sulfobutyl ether sodium, n-dodecyl (diethyleneoxy) sulfobutyl ether sodium, n-octyl ( Diethyleneoxy) sulfobutyl ether potassium, 2-ethylhexyl (diethyleneoxy) sulfobutyl ether potassium, n-decyl (diethyleneoxy) sulfobutyl ether potassium, n-dodecyl (diethyleneoxy) sulfopropyl ether potassium, n-octyl (diethyleneoxy) sulfopropyl Sodium ether, 2-ethylhexyl (diethyleneoxy) sulfopropyl ether sodium, n-de Sodium (diethyleneoxy) sulfopropyl ether, n-dodecyl (diethyleneoxy) sulfopropyl ether sodium, 2-ethylhexyl (diethyleneoxy) sulfobutyl ether / ammonium salt, 2-ethylhexyl (diethyleneoxy) sulfobutyl ether / triethylammonium salt, 2 -Ethylhexyl (diethyleneoxy) sulfobutyl ether, pyridinium, etc. can be mentioned.

  Organic sulfates include sulfates of alkyl, alkenyl, alkynyl, aryl or heterocyclic monoethers of polyethylene oxide. The number of ethylene oxide units is preferably 1 to 4, and the salt is preferably a sodium salt, potassium salt or lithium salt.

  As the betaines, compounds having 1 to 5 carbon atoms of the hydrocarbon substituent on the nitrogen atom are preferable. Specific examples include trimethylammonium acetate, dimethylpropylammonium acetate, 3-hydroxy-4-trimethyl. Ammonioobylate, 4- (1-pyridinio) butyrate, 1-hydroxyethyl-1-imidazolioacetate, trimethylammonium methanesulfonate, dimethylpropylammonium methanesulfonate, 3-trimethylammonio-1-propanesulfonate, Examples include 3- (1-pyridinio) -1-propanesulfonate.

  The above low molecular weight hydrophilic compound improves the permeability of dampening water into the unexposed area (non-image area) of the image recording layer, while reducing the hydrophobicity and film strength of the image area. The ink acceptability and printing durability of the layer can be maintained well.

The amount of these low molecular weight hydrophilic compounds added to the image recording layer is preferably 0.5% by mass or more and 20% by mass or less of the total solid content of the image recording layer. More preferably, it is 1 mass% or more and 10 mass% or less, More preferably, it is 2 mass% or more and 8 mass% or less. In this range, good on-press developability and printing durability can be obtained.
These compounds may be used alone or in combination of two or more.

(F) Grease-sensitizing agent In the image recording layer of the present invention, a lipid-sensitizing agent such as a phosphonium compound, a nitrogen-containing low molecular weight compound, or an ammonium group-containing polymer is used in the image recording layer in order to improve the inking property. be able to. In particular, when an inorganic stratiform compound is contained in the oxygen barrier layer, these compounds function as a surface coating agent for the inorganic stratiform compound, and prevent deterioration of the inking property during printing due to the inorganic stratiform compound.

  Suitable phosphonium compounds include phosphonium compounds described in JP-A-2006-297907 and JP-A-2007-50660. Specific examples include tetrabutylphosphonium iodide, butyltriphenylphosphonium bromide, tetraphenylphosphonium bromide, 1,4-bis (triphenylphosphonio) butanedi (hexafluorophosphate), 1,7-bis (tri Phenylphosphonio) heptane sulfate, 1,9-bis (triphenylphosphonio) nonane = naphthalene-2,7-disulfonate, and the like.

  Examples of the nitrogen-containing low molecular weight compound include amine salts and quaternary ammonium salts. Also included are imidazolinium salts, benzoimidazolinium salts, pyridinium salts, and quinolinium salts. Of these, quaternary ammonium salts and pyridinium salts are preferable. Specific examples include tetramethylammonium = hexafluorophosphate, tetrabutylammonium = hexafluorophosphate, dodecyltrimethylammonium = p-toluenesulfonate, benzyltriethylammonium = hexafluorophosphate, benzyldimethyloctylammonium = hexafluorophosphate. Examples thereof include fert and benzyldimethyldodecyl ammonium = hexafluorophosphate.

  The ammonium group-containing polymer may be any polymer as long as it has an ammonium group in its structure, but a polymer containing 5 to 80 mol% of a (meth) acrylate having an ammonium group in the side chain as a copolymerization component is preferable. .

  The ammonium salt-containing polymer has a reduced specific viscosity (unit: cSt / g / ml) determined by the following measurement method, preferably in the range of 5 to 120, more preferably in the range of 10 to 110. The range of 15-100 is especially preferable.

<Measurement method of reduced specific viscosity>
Weigh 3.33 g of 30% polymer solution (1 g as solid content) into a 20 ml volumetric flask and make up with N-methylpyrrolidone. This solution is put into an Ubbelohde reduced viscosity tube (viscosity constant = 0.010 cSt / s), and the time to flow down at 30 ° C. is measured. The calculation formula (“kinematic viscosity” = “viscosity constant” × “ Time of passage (second) ") was calculated by a conventional method.

Specific examples of the ammonium group-containing polymer are shown below.
(1) 2- (trimethylammonio) ethyl methacrylate = p-toluenesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 10/90)
(2) 2- (Trimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80)
(3) 2- (Ethyldimethylammonio) ethyl methacrylate = p-toluenesulfonate / hexyl methacrylate copolymer (molar ratio 30/70)
(4) 2- (Trimethylammonio) ethyl methacrylate = hexafluorophosphate / 2-ethylhexyl methacrylate copolymer (molar ratio 20/80)
(5) 2- (Trimethylammonio) ethyl methacrylate = methyl sulfate / hexyl methacrylate copolymer (molar ratio 40/60)
(6) 2- (butyldimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80)
(7) 2- (Butyldimethylammonio) ethyl acrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80)
(8) 2- (butyldimethylammonio) ethyl methacrylate = 13-ethyl-5,8,11-trioxa-1-heptadecanesulfonate / 3,6-dioxaheptyl methacrylate copolymer (molar ratio 20/80 )
(9) 2- (butyldimethylammonio) ethyl methacrylate = hexafluorophosphate / 3,6-dioxaheptyl methacrylate / 2-hydroxy-3-methacryloyloxypropyl methacrylate copolymer (molar ratio 15/80/5 )

  The content of the sensitizer is preferably 0.01 to 30.0% by mass, more preferably 0.1 to 15.0% by mass and 1 to 5% by mass with respect to the total solid content of the image recording layer. Is more preferable.

(Other)
Further, as other components, surfactants, colorants, baking-out agents, polymerization inhibitors, higher fatty acid derivatives, plasticizers, inorganic fine particles, inorganic layered compounds, and co-sensitizers or chain transfer agents may be added. it can. Specifically, paragraph numbers [0114] to [0159] of Japanese Patent Application Laid-Open No. 2008-284817, paragraph numbers [0023] to [0027] of Japanese Patent Application Laid-Open No. 2006-091479, US Patent Application Publication No. 2008/0311520. The compounds and addition amounts described in the specification [0060] are preferred.

(G) Formation of Image Recording Layer The image recording layer in the present invention may be prepared by using the necessary components described above as described in paragraphs [0142] to [0143] of JP-A-2008-195018, for example. A coating solution is prepared by dispersing or dissolving in a coating solution, which is formed by applying the coating solution on a support by a known method such as bar coater coating and drying. The image recording layer coating amount (solid content) on the support obtained after coating and drying varies depending on the application, but is generally preferably 0.3 to 3.0 g / m ² . Within this range, good sensitivity and good film characteristics of the image recording layer can be obtained.

(Undercoat layer)
In the lithographic printing plate precursor according to the invention, an undercoat layer (sometimes referred to as an intermediate layer) is preferably provided between the image recording layer and the support. The undercoat layer enhances the adhesion between the support and the image recording layer in the exposed area, and easily peels off the image recording layer from the support in the unexposed area. Contributes to improvement. In the case of infrared laser exposure, the undercoat layer functions as a heat insulating layer, thereby preventing the heat generated by the exposure from diffusing to the support and reducing the sensitivity.

Specific examples of the compound used for the undercoat layer include silane coupling agents having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, and JP-A-2- Examples thereof include phosphorus compounds having an ethylenic double bond reactive group described in Japanese Patent No. 304441. More preferable is a polymer resin having an adsorptive group, a hydrophilic group, and a crosslinkable group that can be adsorbed on the surface of the support, as described in JP-A Nos. 2005-125749 and 2006-188038. It is done. The polymer resin is preferably a copolymer of a monomer having an adsorptive group, a monomer having a hydrophilic group, and a monomer having a crosslinkable group. More specifically, a phenolic hydroxyl group, a carboxyl _{group, -PO 3 H 2, -OPO 3} H 2, -CONHSO 2 -, - SO 2 NHSO 2 -, - having an adsorptive group such as COCH 2 COCH ₃ Examples thereof include a polymer resin that is a copolymer of a monomer, a monomer having a hydrophilic sulfo group, and a monomer having a polymerizable crosslinkable group such as a methacryl group or an allyl group. This polymer resin may have a crosslinkable group introduced by salt formation between a polar substituent of the polymer resin, a substituent having a counter charge and a compound having an ethylenically unsaturated bond, Other monomers, preferably hydrophilic monomers, may be further copolymerized.

The content of unsaturated double bonds in the polymer resin for the undercoat layer is preferably 0.1 to 10.0 mmol, and most preferably 2.0 to 5.5 mmol, per 1 g of the polymer resin.
The polymer resin for the undercoat layer preferably has a mass average molar mass of 5000 or more, more preferably 10,000 to 300,000.

  The undercoat layer of the present invention comprises, in addition to the above undercoat compound, a chelating agent, a secondary or tertiary amine, a polymerization inhibitor, an amino group, or a functional group having a polymerization inhibiting ability, in order to prevent contamination over time. Compounds having a group that interacts with the surface of an aluminum support (for example, 1,4-diazabicyclo [2,2,2] octane (DABCO), 2,3,5,6-tetrahydroxy-p-quinone, chloranil , Sulfophthalic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminediacetic acid, hydroxyethyliminodiacetic acid, and the like.

The undercoat layer is applied by a known method. The coating amount (solid content) of the undercoat layer is preferably from 0.1 to 100 mg / m ² , and more preferably from ¹ to 30 mg / m ² .

(Support)
As the support used in the lithographic printing plate precursor according to the invention, a known support is used. Of these, an aluminum plate that has been roughened and anodized by a known method is preferred.
In addition, the above aluminum plate is optionally subjected to micropore enlargement treatment or sealing treatment of an anodized film described in JP-A Nos. 2001-253181 and 2001-322365, and US Pat. 714,066, 3,181,461, 3,280,734 and 3,902,734, or alkali metal silicates as described in U.S. Pat. Surface hydrophilization treatment with polyvinylphosphonic acid or the like as described in each specification of 3,276,868, 4,153,461 and 4,689,272 is appropriately performed and performed. be able to.
The support preferably has a center line average roughness of 0.10 to 1.2 μm.

  If necessary, the support of the present invention includes an organic polymer compound described in JP-A-5-45885 and a silicon alkoxy compound described in JP-A-5-45885 on the back surface. A backcoat layer can be provided.

(Oxygen barrier layer)
In the lithographic printing plate precursor according to the invention, an oxygen blocking layer (overcoat layer) is preferably provided on the image recording layer. In addition to the function of suppressing the image formation inhibition reaction by blocking oxygen, the oxygen blocking layer has a function of preventing scratches in the image recording layer and preventing ablation during high-illuminance laser exposure.

  The oxygen barrier layer having such characteristics is described in, for example, US Pat. No. 3,458,311 and JP-B-55-49729. As the low oxygen permeability polymer used for the oxygen blocking layer, any one of a water-soluble polymer and a water-insoluble polymer can be appropriately selected and used. Specific examples include polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, water-soluble cellulose derivatives, poly (meth) acrylonitrile, and the like.

In order to enhance oxygen barrier properties, the oxygen barrier layer preferably contains an inorganic layered compound such as natural mica and synthetic mica as described in JP-A-2005-119273.
Further, the oxygen barrier layer may contain known additives such as a plasticizer for imparting flexibility, a surfactant for improving coating properties, and inorganic fine particles for controlling surface slipperiness. Further, the oil-sensitizing agent described in the description of the image recording layer can be contained in the oxygen blocking layer.

The oxygen barrier layer is applied by a known method. The coating amount of the oxygen blocking layer, the coating amount after drying is preferably in the range of 0.01 to 10 g / ^{m 2,} more preferably in the range of 0.02 to 3 g / ^{m 2,} most preferably 0 The range is 0.02 to 1 g / m ² .

[Plate making method]
The plate making of the lithographic printing plate precursor according to the invention is preferably carried out by an on-press development method. The on-press development method includes an image exposure process for a lithographic printing plate precursor, a printing process in which an oil-based ink and an aqueous component are supplied and printed without performing any development process on the exposed lithographic printing plate precursor. And the unexposed portion of the lithographic printing plate precursor is removed during the printing process. Imagewise exposure may be performed on the printing machine after the lithographic printing plate precursor is mounted on the printing machine, or may be separately performed with a plate setter or the like. In the latter case, the exposed lithographic printing plate precursor is mounted on a printing machine without undergoing a development process. Thereafter, by using the printing machine and supplying the oil-based ink and the aqueous component and printing as it is, an on-press development process, that is, an image recording layer in an unexposed area is removed at an early stage of printing, Accordingly, the surface of the hydrophilic support is exposed to form a non-image part. As the oil-based ink and the aqueous component, ordinary lithographic printing ink and fountain solution are used.
This will be described in more detail below.

In the present invention, the light source used for image exposure is preferably a laser. Although the laser used for this invention is not specifically limited, The solid laser and semiconductor laser etc. which irradiate infrared rays with a wavelength of 760-1200 nm are mentioned suitably.
Regarding the infrared laser, the output is preferably 100 mW or more, the exposure time per pixel is preferably within 20 microseconds, and the irradiation energy amount is preferably 10 to 300 mJ / cm ² . In the laser, it is preferable to use a multi-beam laser device in order to shorten the exposure time.

  The exposed lithographic printing plate precursor is mounted on a plate cylinder of a printing press. In the case of a printing press equipped with a laser exposure device, image exposure is performed after a lithographic printing plate precursor is mounted on a plate cylinder of the printing press.

  When printing is performed by supplying dampening water and printing ink to the lithographic printing plate precursor exposed imagewise, the image recording layer cured by exposure has a printing ink acceptance having an oleophilic surface in the exposed portion of the image recording layer. Forming part. On the other hand, in the unexposed area, the uncured image recording layer is removed by dissolution or dispersion by the supplied dampening water and / or printing ink, and a hydrophilic surface is exposed in that area. As a result, the fountain solution adheres to the exposed hydrophilic surface, and the printing ink is deposited on the image recording layer in the exposed area and printing is started.

Here, dampening water or printing ink may be supplied to the printing plate first, but printing is first performed in order to prevent the dampening water from being contaminated by the removed image recording layer components. It is preferable to supply ink.
In this way, the lithographic printing plate precursor according to the invention is developed on the machine on an offset printing machine and used as it is for printing a large number of sheets.

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

[Examples 1 to 20 and Comparative Examples 51 to 61]

1. Production of lithographic printing plate precursors (1) to (20) of the present invention and comparative lithographic printing plate precursors (51) to (59) (1) Production of support Aluminum plate (material JIS A 1050) having a thickness of 0.3 mm In order to remove the rolling oil on the surface of), after degreasing at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution, three bundled nylon brushes having a bristle diameter of 0.3 mm and a median diameter of 25 μm The pumice-water suspension (specific gravity 1.1 g / cm ³ ) was used to grain the aluminum surface and washed thoroughly with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in 20 mass% nitric acid at 60 ° C for 20 seconds, and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² .

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

Subsequently, nitric acid electrolysis was performed with an aqueous solution of 0.5% by mass of hydrochloric acid (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. under the condition of an electric quantity of 50 C / dm ² when the aluminum plate was the anode. In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying.
Next, the plate was provided with a direct current anodic oxide film having a current density of 15 A / dm ² and a current density of 15 g / m ² using 15% by mass sulfuric acid (containing 0.5% by mass of aluminum ions) as an electrolytic solution, followed by washing with water. It dried and produced the support body (1).
Thereafter, in order to ensure the hydrophilicity of the non-image area, the support (1) was subjected to a silicate treatment at 60 ° C. for 10 seconds using an aqueous 2.5 mass% No. 3 sodium silicate solution, and then washed with water for support. Body (2) was obtained. The adhesion amount of Si was 10 mg / m ² . The centerline average roughness (Ra) of this substrate was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

(2) Formation of undercoat layer Next, the following undercoat layer coating solution (1) is applied onto the support (2) so that the dry coating amount is 20 mg / m ² , and used in the following experiments. A support having a layer was prepared.

<Coating liquid for undercoat layer (1)>
-Undercoat layer compound (1) having the following structure: 0.18 g
・ Hydroxyethyliminodiacetic acid 0.10g
・ Methanol 55.24g
・ Water 6.15g

(3) Formation of image recording layer The image recording layer coating solution (1) having the following composition was bar-coated on the undercoat layer formed as described above, and then oven-dried at 100 ° C for 60 seconds to obtain a dry coating amount. An image recording layer of 1.0 g / m ² was formed.
The image recording layer coating solution (1) was obtained by mixing and stirring the following photosensitive solution (1) and microgel solution (1) immediately before coating.

<Photosensitive solution (1)>
・ The present invention and comparative ultraviolet absorbers 0.030 g of the types described in Table (1)
-Binder polymer (1) [the following structure] 0.240 g
Infrared absorber (1) [the following structure] 0.030 g
-Radical polymerization initiator (1) [the following structure] 0.162 g
Polymerizable compound tris (acryloyloxyethyl) isocyanurate (NK ester A-9300, manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.192 g
・ Low molecular weight hydrophilic compound Tris (2-hydroxyethyl) isocyanurate 0.062g
・ Low molecular weight hydrophilic compound (1) [the following structure] 0.050 g
-Sensitizing agent Phosphonium compound (1) [the following structure] 0.055 g
・ Sensitizer Benzyl-dimethyl-octylammonium ・ PF ₆ salt 0.018g
-Sensitizer Ammonium group-containing polymer [the following structure, reduced specific viscosity 44 cSt / g / ml] 0.030 g
・ Fluorosurfactant (1) [The following structure] 0.008g
・ 2-butanone 1.091g
・ 1-methoxy-2-propanol 8.609g

<Microgel solution (1)>
・ Microgel (1) 2.640 g
・ Distilled water 2.425g

  Binder polymer (1), infrared absorber (1), radical polymerization initiator (1), phosphonium compound (1), low molecular weight hydrophilic compound (1), ammonium group-containing polymer, and fluorosurfactant The structure of (1) is as shown below.

  Comparative compounds (UV absorbers outside the present invention) are shown below.

-Synthesis of microgel (1)-
As an oil phase component, trimethylolpropane and xylene diisocyanate adduct (Mitsui Chemical Polyurethane Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., SR444) 3.15 g, And 0.1 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12,000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 50 ° C. for 3 hours. The microgel solution thus obtained was diluted with distilled water to a solid content concentration of 15% by mass, and this was designated as the microgel (1). When the average particle size of the microgel was measured by a light scattering method, the average particle size was 0.2 μm.

(4) Formation of Oxygen Barrier Layer Further, an oxygen barrier layer coating solution (1) having the following composition was further bar-coated on the image recording layer, followed by oven drying at 120 ° C. for 60 seconds, and a dry coating amount of 0.15 g / An oxygen blocking layer of m ² was formed to obtain lithographic printing plate precursors (1) to (20) and comparative lithographic printing plate precursors (51) to (59) for comparison.

<Coating liquid for oxygen barrier layer (1)>
・ Inorganic layered compound dispersion (1) 1.5 g
-Polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd. CKS50, sulfonic acid modification,
Saponification degree 99 mol% or more, polymerization degree 300) 6% by mass aqueous solution 0.55 g
・ Polyvinyl alcohol (PVA-405 manufactured by Kuraray Co., Ltd.)
Degree of saponification 81.5 mol%, degree of polymerization 500) 6% by weight aqueous solution 0.03 g
・ Nippon Emulsion Co., Ltd. surfactant (Emalex 710) 1% by weight aqueous solution 0.86g
・ Ion-exchanged water 6.0g

(Preparation of inorganic layered compound dispersion (1))
6.4 g of synthetic mica Somasif ME-100 (manufactured by Coop Chemical Co., Ltd.) was added to 193.6 g of ion-exchanged water, and dispersed using an homogenizer until the average particle size (laser scattering method) became 3 μm. The aspect ratio of the obtained dispersed particles was 100 or more.

2. Preparation of comparative lithographic printing plate precursors (60) and (61) The comparative lithographic printing plate precursor (60) is exactly the same as the lithographic printing plate precursor (1) except that no ultraviolet absorber was added to the image recording layer. It was made as follows.
In the comparative planographic printing plate precursor (61), an ultraviolet absorber was added to the oxygen blocking layer instead of the image recording layer. That is, it was prepared in the same manner as the lithographic printing plate precursor (60) for comparison except that the oxygen blocking layer coating solution (2) obtained by adding 0.03 g of the ultraviolet absorber I-1 to the oxygen blocking layer coating solution (1) was used. .

  [Examples 31-39 and Comparative Examples 71-80]

3. Production of lithographic printing plate precursors (31) to (39) and comparative lithographic printing plate precursors (71) to (80) of the present invention The following image recording layer coating solution (2) is applied to the above support having an undercoat layer. And then dried in an oven at 70 ° C. for 60 seconds to produce an image recording layer having a dry coating amount of 0.6 g / m ² , and the planographic printing plate precursors (31) to (39) of the present invention and comparative examples Lithographic printing plate precursors (71) to (79) were obtained. [For Examples 31-39 and Comparative Examples 71-79]
A comparative lithographic printing plate precursor (80) was prepared in exactly the same manner as the lithographic printing plate precursor (31) except that no ultraviolet absorber was added to the image recording layer. [For Comparative Example 80].

<Image recording layer coating solution (2)>
・ The present invention and comparative UV absorbers 0.2 g of the types described in Table (2)
-Polymer fine particle aqueous dispersion (1) 20.0 g
・ Infrared absorber (2) [the following structure] 0.2 g
・ Radical polymerization initiator Irgacure 250 (Ciba Specialty Chemicals) 0.5g
-Polymerizable compound SR-399 (manufactured by Sartomer) 1.55 g
・ Mercapto-3-triazole 0.2g
・ Byk336 (byk chimie) 0.4g
・ KlucelM (Hercules) 4.8g
・ ELVACITE 4026 (manufactured by Ineos Acrylica) 2.5g
・ N-propanol 55.0g
・ 2-butanone 17.0g

In addition, the compounds described by trade names in the above composition are as follows.
Irgacure 250: (4-methoxyphenyl) [4- (2-methylpropyl) phenyl] iodonium = hexafluorophosphate (75% by mass propylene carbonate solution)
SR-399: dipentaerythritol pentaacrylate
Byk 336: modified dimethylpolysiloxane copolymer (25% by mass xylene / methoxypropyl acetate solution)
・ Klucel M: Hydroxypropyl cellulose (2% by mass aqueous solution)
ELVACITE 4026: Hyperbranched polymethyl methacrylate (10% by mass 2-butanone solution)

(Production of polymer fine particle aqueous dispersion (1))
A 1000 ml four-necked flask was equipped with a stirrer, thermometer, dropping funnel, nitrogen inlet tube, reflux condenser, and nitrogen gas was introduced to perform deoxygenation, while polyethylene glycol methyl ether methacrylate (average of PEGMA ethylene glycol) The repeating unit was 50) 10 g, distilled water 200 g and n-propanol 200 g were added and heated until the internal temperature reached 70 ° C. Next, a premixed mixture of 10 g of styrene (St), 80 g of acrylonitrile (AN) and 0.8 g of 2,2′-azobisisobutyronitrile was added dropwise over 1 hour. After completion of the dropwise addition, the reaction was continued for 5 hours, and then 0.4 g of 2,2′-azobisisobutyronitrile was added to raise the internal temperature to 80 ° C. Subsequently, 0.5 g of 2,2′-azobisisobutyronitrile was added over 6 hours. Polymerization progressed 98% or more at the stage of reaction for a total of 20 hours, and a polymer fine particle aqueous dispersion (1) having a mass ratio of PEGMA / St / AN = 10/10/80 was obtained. The particle size distribution of the polymer fine particles had a maximum value at a particle size of 150 nm.

  Here, the particle size distribution is obtained by taking an electron micrograph of polymer fine particles, measuring a total of 5000 fine particle sizes on the photograph, and a logarithmic scale between 0 and the maximum value of the obtained particle size measurement values. And the frequency of appearance of each particle size was plotted and obtained. For non-spherical particles, the particle size of spherical particles having the same particle area as that on the photograph was used as the particle size.

4). Evaluation of Planographic Printing Plate Precursors The present invention and comparative lithographic printing plate precursors were evaluated by the following methods, and the results are summarized in Tables 1 and 2.

(1) On-machine developability The obtained lithographic printing plate precursor was subjected to an external drum rotation speed of 1000 rpm, a laser output of 70%, and a resolution of 2400 dpi on a Fujifilm Co., Ltd. Luxel PLASETTER T-6000III equipped with an infrared semiconductor laser. Exposed. The exposure image included a solid image and a 50% halftone dot chart of a 20 μm dot FM screen.
The obtained exposed original plate was attached to a plate cylinder of a printing machine LITHRONE 26 manufactured by Komori Corporation without developing. Equality-2 (manufactured by FUJIFILM Corporation) / tap water = 2/98 (volume ratio) dampening water and Values-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.) After dampening water and ink were supplied by the standard automatic printing start method of LITHRONE 26 and developed on the machine, 100 sheets were printed on Tokuhishi Art (76.5 kg) paper at a printing speed of 10,000 sheets per hour.
The number of print sheets required until the on-press development on the printing press of the unexposed portion of the image recording layer was completed and the ink was not transferred to the non-image portion was measured as on-press developability.
Further, as an evaluation of mercury lamp resistance, the on-press developability was measured in the same manner after leaving the exposed lithographic printing plate for 1 hour using a 5700K high-pressure mercury lamp and adjusting the illuminance to 500 lux.
The results are shown in Table 1.

(2) Printing durability After the above-described evaluation of on-press developability, the printing was further continued. As the number of printed sheets was increased, the image recording layer was gradually worn out, so that the ink density on the printed material decreased. Printing durability was evaluated using the number of printed copies when the value measured by the Gretag densitometer for the 50% halftone dot area ratio of the FM screen in the printed material was 5% lower than the measured value for the 100th printed sheet. .

From Table 1 and Table 2, the following can be understood. It can be seen that in the comparative example (60) containing no ultraviolet absorber, the on-press developability is significantly deteriorated by storage under a mercury lamp. Further, in Comparative Example (61) containing an ultraviolet absorber in the oxygen blocking layer, the on-machine developability is poor even immediately after exposure (normal conditions), and is further deteriorated when stored under a mercury lamp. A comparative lithographic printing plate precursor containing an ultraviolet absorber other than the present invention in the image recording layer shows a certain improvement effect when stored under a mercury lamp, but the degree of improvement is not sufficient, and it is not sufficient immediately after exposure. A decrease in top developability is observed. In contrast, the lithographic printing plate precursor according to the present invention has an unexpected effect that the on-press developability hardly deteriorates even if it is left under exposure to a mercury lamp as well as immediately after exposure, and is easy to handle at the printing site. An excellent lithographic printing plate precursor that is greatly improved can be obtained.
From the above, the effects of the present invention are clear.

[Example 40 and Comparative Example 81]

5). Preparation of lithographic printing plate precursors (40) and (81) A lithographic printing plate except that the image recording layer coating solution (2) in the lithographic printing plate precursor (31) is replaced by the following image recording layer coating solution (3) A lithographic printing plate precursor (40) was produced in the same manner as the original plate (31).
Lithographic printing for comparison in the same manner as the lithographic printing plate precursor (71) except that the image recording layer coating solution (2) in the lithographic printing plate precursor (71) is replaced with the following image recording layer coating solution (3). A plate precursor (81) was produced.

<Image recording layer coating solution (3)>
The image recording layer coating solution (2) except that 72 g of the following polymer fine particle aqueous dispersion (2) was added instead of 20.0 g of the polymer fine particle aqueous dispersion (1) used in the image recording layer coating solution (2). Similarly, an image recording layer coating solution (3) was prepared.

Preparation of Polymer Fine Particle Aqueous Dispersion (2) To a 200 ml three-necked flask equipped with a mechanical stirrer, 85 g of water, 0.3 g of sodium dodecyl sulfate (SDS), 4.5 g of acrylonitrile and 0.5 g of styrene were added and completely dissolved. Next, after the inside of the system was purged with nitrogen, a nitrogen flow (flow rate: 10 ml / min) was performed. Next, after heating up to 70 degreeC, potassium persulfate aqueous solution (0.27g of potassium persulfate, 10g of water) was dripped over 2 hours, stirring at the rotational speed of 300 rpm. After completion of dropping, the mixture was stirred at 70 ° C. for 3 hours, then heated to 80 ° C. and stirred for 2 hours. An aqueous polymer fine particle dispersion (2) having a mass ratio of St / AN = 10/90 was obtained. The particle size distribution of the polymer fine particles had a maximum value at a particle size of 125 nm. The solid content was 5.5% by mass.

6). Evaluation of lithographic printing plate precursors (40) and (81) Evaluation of the lithographic printing plate precursor (40) and the comparative lithographic printing plate precursor (81) was performed according to the evaluation method of the lithographic printing plate precursor described above (Example 40 and Comparative Example 81). The results are shown in Table 3. Table 3 also shows the results of Example 31 and Comparative Example 71.

  From Table 3, by including a polyoxyalkylene structure in the polymer contained in the image recording layer, there is no difference in on-press developability (normal) and on-press developability (under mercury lamp conditions), and mercury lamp resistance is good. It turns out that it has become.

Claims (7)

  On the support, it has an image recording layer containing (A) an infrared absorber, (B) a radical polymerization initiator, and (C) a polymerizable compound, and printing ink and dampening water on the printing press after image exposure. A lithographic printing plate precursor capable of forming an image by supplying at least one of the above and removing an unexposed portion of the image recording layer, wherein the image recording layer further comprises (D) a polyoxyalkylene structure. A lithographic printing plate precursor comprising an ultraviolet absorber having at least one. The lithographic printing plate precursor as claimed in claim 1, wherein the polyoxyalkylene structure is represented by the following general formula (A).
Formula (A)-(CHR ₁₀₁ CHR ₁₀₂ O) _n -R ₁₀₃
In the formula, R ₁₀₁ and R ₁₀₂ each independently represent a hydrogen atom or a substituent, and R ₁₀₃ represents a hydrogen atom or a substituent. n represents an integer of 2 to 50. In the polyoxyalkylene structure represented by the general formula (A), R ₁₀₁ and R ₁₀₂ each independently represent a hydrogen atom or a methyl group, and R ₁₀₃ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The lithographic printing plate precursor as claimed in claim 2, wherein: The ultraviolet absorber is at least one selected from compounds represented by the following formulas (1), (2), and (4) to (9). The lithographic printing plate precursor according to any one of claims 1 to 3.

In the formula, R _{11 to} R ₁₈ each independently represents a hydrogen atom or a substituent. However, at least one of R _{11 to} R ₁₈ represents a group having a polyoxyalkylene structure.

_Wherein, X 21 _{to X 23} each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a heterocyclic group. However, at least one of X _{21 to} X ₂₃ represents a group represented by the following general formula (3), and at least one of X _{21 to} X ₂₃ and R _{31 to} R ₃₄ has a polyoxyalkylene structure. Represents a group having

_Wherein, R 31 _{to R 34} each independently represent a hydrogen atom or a substituent.

_Wherein, R 40 _{to R 49} each independently represent a hydrogen atom or a substituent. However, at least one of R _{40 to} R ₄₉ represents a group having a polyoxyalkylene structure. X ₄₁ represents —CO— or —COO—.

_Wherein, R 51 _{to R 55} each independently represent a hydrogen atom or a substituent. X ₅₁ represents a hydrogen atom or an alkyl group, and Y ₅₁ and Y ₅₂ each independently represent a hydrogen atom, a cyano group, —COOZ ₅₁ , —CONHZ ₅₁ , —COZ ₅₁ , —SO ₂ Z ₅₁ or —SO ₂ NHZ. ₅₁ , and Z ₅₁ represents a hydrogen atom, an alkyl group, or an aryl group. Y ₅₁ and Y ₅₂ may be connected to each other to form a ring. However, at least one of R _{51 to} R ₅₅ , Y ₅₁ and Y ₅₂ represents a group having a polyoxyalkylene structure.

In the formula, R ₆₁ and R ₆₂ each independently represent a hydrogen atom, an alkyl group, or an aryl group. R ₆₁ and R ₆₂ may be connected to each other to form a 5- or 6-membered ring. Y ₆₁ and Y ₆₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R ₆₁ , R ₆₂ , Y ₆₁ and Y ₆₂ represents a group having a polyoxyalkylene structure.

_Wherein, R 70 _{to R 79} each independently represent a hydrogen atom or a substituent. X ₇₁ and X ₇₂ each independently represent a hydrogen atom, an alkyl group or an aryl group. However, at least one of R _{70 to} R ₇₉ , X ₇₁ and X ₇₂ represents a group having a polyoxyalkylene structure.

In formula, R < ₈₁ > -R < ₈₄ > represents a hydrogen atom or a substituent each independently. L ₈₁ represents a single bond or a double bond. However, when L ₈₁ represents a double bond, R ₈₁ and R ₈₄ are not present. R ₈₂ and R ₈₃ may be bonded to each other to form a ring. X ₈₁ represents an alkyl group or an aryl group. Z ₈₁ represents an oxygen atom, a sulfur atom, —N (R ₈₅ ) — or —C (R ₈₆ ) (R ₈₇ ) —, R ₈₅ represents an alkyl group or an aryl group, and R ₈₆ and R ₈₇ each represent Independently, it represents a hydrogen atom or an alkyl group, and R ₈₆ and R ₈₇ may be bonded to each other to form a ring. Y ₈₁ and Y ₈₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R _{81 to} R ₈₄ , X ₈₁ , Y ₈₁ , Y ₈₂ and Z ₈₁ represents a group having a polyoxyalkylene structure. n represents 0 or 1.

_Wherein, R 91 _{to R 94} each independently represent a hydrogen atom or a substituent. Y ₉₁ and Y ₉₂ are synonymous with Y ₅₁ and Y ₅₂ in the general formula (5). However, at least one of R _{91 to} R ₉₄ , Y ₉₁ and Y ₉₂ represents a group having a polyoxyalkylene structure.   The lithographic printing plate precursor as claimed in any one of claims 1 to 4, wherein the image recording layer further comprises (E) a polymer compound containing a polyoxyalkylene structure.   The lithographic printing plate precursor as claimed in any one of claims 1 to 5, further comprising an oxygen barrier layer on the image recording layer.   The lithographic printing plate precursor according to any one of claims 1 to 6 is supplied with at least one of printing ink and fountain solution on a printing press without passing through a development processing step after exposure, and an unexposed portion. A process for making a lithographic printing plate characterized in that the lithographic printing plate is prepared by removing