JP2009258410A - Planographic printing plate material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planographic printing plate material excellent in scratch resistance, sensitivity, development latitude and chemical resistance. <P>SOLUTION: The planographic printing plate material has a positive image forming layer on a support body, wherein the positive image forming layer contains a compound expressed by a general formula (1). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lithographic printing plate material used in a so-called computer-to-plate (hereinafter referred to as “CTP”) system, and more particularly to a positive electrode capable of forming an image by exposure with a near-infrared laser. The invention relates to a lithographic printing plate material of a mold.

  In recent years, with the digitization of plate making data, a so-called CTP system that modulates digital data directly into a laser signal and exposes a lithographic printing plate has become widespread. In recent years, the development of lasers has been remarkable. In particular, solid-state lasers and semiconductor lasers having a light emitting region from near infrared to infrared can be easily obtained with high output and small size. These lasers are very useful as an exposure light source when directly making a plate from digital data such as a computer.

  In recent years, along with the shortened delivery time of printed materials, productivity of exposure apparatuses has been improved, that is, exposure time and transport time have been shortened. Also in printing, productivity is improved by 2-sided or 4-sided printing on large plates. In the situation as described above, a large plate exposure machine may cause scratches on the plate material due to conveyance, etc., and improvements have been made from the exposure apparatus, but it is not sufficient, and improvements from the plate material are also desired. It is rare.

  On the other hand, as an infrared laser lithographic printing plate, a positive lithographic printing plate precursor having a recording layer containing (A) an aqueous alkaline solution-soluble resin having a phenolic hydroxyl group such as a cresol novolak resin and (B) an infrared absorber is known. (For example, refer to Patent Document 1). In this positive type lithographic printing original plate, the association state of the cresol novolak resin is changed by the action of heat generated by the infrared absorber in the exposed area, resulting in a difference in solubility (dissolution rate difference) from the unexposed area. Is used to develop and form an image. However, because the difference in dissolution rate is small, the development latitude is narrow, the amount of heat is reduced in the portion close to the support, and the effect of clearing the development inhibiting ability (clear sensitivity) of the recording layer in the non-image area cannot be sufficiently obtained. There was a problem.

  In order to solve such problems of insufficient sensitivity and narrow development latitude, improved techniques have been proposed from the viewpoint of improving the association state of the cresol novolac resin, that is, hydrogen bondability. For example, a lithographic printing plate material in which an amide group or a quinonediazide group is introduced into a novolak resin to improve sensitivity and development latitude has been proposed (see Patent Documents 2 and 3). However, although the sensitivity and development latitude are improved by the introduction of the above substituents, it is still insufficient, and the scratch resistance in the high-speed exposure machine in the above large plate and the chemical resistance to the plate cleaner at the time of printing are insufficient. There was a problem that there was.

Furthermore, a novolak resin having a substituent capable of forming a lone pair having a hydrogen bond has been proposed (see Patent Document 4), but this also has a sensitivity to a developing solution, a development latitude, and a large version. The scratch resistance was insufficient.
WO 97/39894 pamphlet Japanese Patent No. 3836605 Japanese Patent Laid-Open No. 11-288089 Special Table 2004-526986

  An object of the present invention is to provide a lithographic printing plate material that is excellent in scratch resistance, excellent in sensitivity and development latitude, and excellent in chemical resistance.

The above object of the present invention is achieved by the following constitution.
1. A lithographic printing plate material having a positive image forming layer on a support, wherein the positive image forming layer contains a compound represented by the following general formula (1).

[Wherein, J represents an n-valent group having no ureido group or ureylene group. n represents an integer of 2 to 4. R represents a substituent. ]
2. 2. The lithographic printing plate material according to 1, wherein J in the general formula (1) is an aliphatic group.
3. The lithographic printing plate material according to 1 or 2, wherein R in the general formula (1) is a heterocyclic group.
4). The lithographic printing plate material according to any one of 1 to 3, wherein R in the general formula (1) is a nitrogen-containing 5-membered cyclic group or a nitrogen-containing 6-membered cyclic group.
5. The lithographic printing plate material according to any one of 1 to 4, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[Wherein R ₂ represents a substituent. ]
6). The lithographic printing plate material according to any one of 1 to 4, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (3).

[Wherein, J represents a divalent group having no ureido group or ureylene group. R ₃ is an aliphatic group, alkoxycarbonyl group, aryloxycarbonyl group, aryl group, aromatic or non-aromatic 5-membered heterocyclic group, non-aromatic 6-membered heterocyclic group, pyridine residue, pyrazine residue, or The group represented by General formula (4) is represented.

In the formula, R ₄ represents an aliphatic group, an aryl group, or a heterocyclic group. W represents ═NR ₅ , an oxygen atom, or a sulfur atom. R ₅ represents a hydrogen atom or a substituent. ]
7). The lithographic printing plate material according to any one of 1 to 6, wherein the positive image forming layer contains an alkali-soluble resin.
8). The carbon number of the group represented by J in the general formula (1) is 20 or less, and the carbon number of the group represented by R is 20 or less, any one of 1 to 7 2. A lithographic printing plate material according to the item.

The following is mentioned as a more preferable aspect of this invention.
9. The lithographic printing plate material according to any one of 1 to 8, wherein the image forming layer further contains an acid-decomposable compound, an acid generator and a photothermal conversion agent.

  According to the above configuration of the present invention, a lithographic printing plate material having excellent scratch resistance, excellent sensitivity and development latitude, and excellent chemical resistance is provided.

  In the lithographic printing plate material having a positive image forming layer on a support, the present invention is characterized in that the positive image forming layer contains a compound represented by the following general formula (1).

  In the present invention, a lithographic printing plate material excellent in scratch resistance, sensitivity, development latitude and chemical resistance can be obtained by incorporating the compound represented by the general formula (1) in the image forming layer. .

Details will be described below.
(Compound represented by the general formula (1))
In the general formula (1), J represents an n-valent group having no ureido group. n represents an integer of 2 to 4. R represents a substituent.

  Examples of the n-valent group represented by J include residues such as aliphatic groups, aryl groups, and heterocyclic groups.

  As used herein, the term “aliphatic group” means an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, or an aralkyl group, each of which is substituted or unsubstituted.

  Specific examples of the residue of the aliphatic group used as the group represented by J include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, tert-butyl group, pentyl group, Hexyl, decyl, dodecyl, pentadecyl, cyclobutyl, cyclobutenyl, cyclopentyl, cyclopentenyl, cyclopentadienyl, cyclohexyl, cyclohexenyl, cyclohexadienyl, cycloheptyl, cycloheptynyl, Cycloheptadienyl group, cyclooctanyl group, cyclooctenyl group, cyclooctadienyl group, cyclooctatrienyl group, cyclononanyl group, cyclononenyl group, cyclononadienyl group, cyclononatrienyl cyclodecanyl group, cyclodecenyl group, Cyclodecadienyl group, cyclodeca Rieniru group, 1-butenyl, 2-butenyl, 1-hexenyl group, a benzyl group, 1-phenylethyl group, and residues such Isohoroniru group.

  These groups may have a substituent or a halogen atom at an arbitrary position. Specific examples of the substituent include an alkyl group, a cyano group, an alkoxy group, a hydroxy group, an amino group, a carboxyl group, a carbooxy group, An aryl group, a heterocyclic ring, an aryloxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, and an aryloxycarbonyloxy group are exemplified. A cyclic compound (such as a cyclic alkyl group) is preferred to a linear alkyl group.

  The residue of the aryl group may be a monocyclic group or a condensed ring group, and examples thereof include phenyl, naphthyl, anthracenyl, phenanthrenyl, naphthacenyl, triphenylenyl and the like.

  These rings may have various substituents at any position, and as a preferable substituent, a linear or branched alkyl group (preferably having 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, Dodecyl, etc.), an alkoxy group (preferably having 1 to 20 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, dodecyloxy, etc.), an amino group, an aliphatic acylamino group (preferably an alkyl group having 1 to 21 carbon atoms). For example, acetylamino group, heptylamino group, and the like, and aromatic acylamino groups.

  Specific examples of the heterocyclic group residue include pyrrole, indole, furan, thiophene, imidazole, pyrazole, indolizine, quinoline, carbazole, phenothiazine, indoline, thiazole, pyridine, pyridazine, thiadiazine, pyran, thiopyran, and oxadiazole. And residues such as benzoquinoline, thiadiazole, tetrazole, oxazole, coumarin, and chroman. The heterocyclic ring in these groups may be a single ring or may form a condensed ring with other rings. These rings may have various substituents at arbitrary positions, and preferred examples of the substituent include an alkyl group, an aryl group, and an alkoxy group.

  An example of J in the general formula (1) is shown below.

  In the present invention, J is preferably a group having 20 or less carbon atoms. J is preferably a residue of an alkyl group or cycloalkyl group having 3 to 20 carbon atoms, an aromatic group or heterocyclic group residue having 4 to 20 carbon atoms, and an alkyl group or cycloalkyl group having 3 to 20 carbon atoms. And more preferably a cycloalkyl group residue having 5 to 20 carbon atoms. Among these, an isophoronyl group residue is particularly preferable.

  n represents an integer of 2 to 4, preferably 2 or 3, and particularly preferably 2.

  Specific examples of the substituent represented by R include an aliphatic group, an aryl group, a heterocyclic group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a thiocarbonyl group, and the like. Further, these groups may be further substituted with other substituents.

  The aliphatic group used as the substituent represented by R preferably contains a substituent having a nitrogen atom, an oxygen atom, a sulfur atom or the like in the molecule. Specifically, N-butylaminomethyl group, (2-ethoxy) ethoxymethyl group and the like are preferable.

  The aryl group preferably has a hydrogen bonding substituent at the α-position. Specifically, 2-alkoxyphenyl group, 2-alkoxynaphthyl group, 2-fluorophenyl group, 2-fluoronaphthyl group and the like are preferable.

  The heterocyclic group is preferably located at a position adjacent to the carbon (the connecting position of the substituent represented by R) in which the hetero atom of the ring skeleton is connected to the ureido bond, particularly preferably a nitrogen-containing 5-membered ring. Group or 6-membered ring group. Specific examples of the heterocyclic group are preferably an aromatic or non-aromatic 5-membered heterocyclic group, a pyridine residue, a piperidine residue, a quinoline residue, and a quinazoline residue, and particularly preferably a hetero ring that forms a ring skeleton. A 5-membered heterocyclic group containing at least one nitrogen atom as an atom, a pyridine residue, and a piperidine residue.

  More preferably, 2-pyrrole, 2-thiophene, 2-furan, 2-imidazole, 2-thiazole, 2-oxazole, 2-pyrazole, 3-isothiazole, 2-pyridine, 2-thiazoline, 2-piperidine, quinoline. , Quinazoline and triazole residues, particularly preferably 2-pyridine, 2-quinoline and 2-thiazoline residues.

  Specific examples of the alkoxycarbonyl group include a methyloxycarbonyl group, an ethyloxycarbonyl group, and a butyloxycarbonyl group.

  Specific examples of the aryloxycarbonyl group represented by R include a phenyloxycarbonyl group.

  Specific examples of the carbamoyl group include an aminocarbonyl group, a methylaminocarbonyl group, a dimethylaminocarbonyl group, a propylaminocarbonyl group, a pentylaminocarbonyl group, a cyclohexylaminocarbonyl group, a phenylaminocarbonyl group, and a 2-pyridylaminocarbonyl group. It is done.

  Examples of the substituent represented by R include the following structures.

  As R in the general formula (1), a compound having 20 or less carbon atoms is preferably used.

  R is preferably an aryl group or a heterocyclic group, more preferably a nitrogen-containing 5-membered ring group or a 6-membered ring group, a 2-alkoxyphenyl group, a 2-fluorophenyl group, a 2-pyridine residue, a 2-quinoline residue. The group, 2-thiazoline residue, is particularly preferred.

  Next, the compound represented by the general formula (2) will be described.

In the compound represented by the general formula (2), R ₂ represents a substituent.

Examples of the substituent represented by R ₂ include those exemplified as the substituent represented by R in the general formula (1). R2 is preferably an aryl group or a heterocyclic group, more preferably a nitrogen-containing 5-membered ring group or a 6-membered ring group.

  The compound represented by the general formula (3) will be described.

In the compound represented by the general formula (3), R ₃ represents an aliphatic group, an alkoxycarbonyl group, an aryloxycarbonyl group, an aryl group, an aromatic or non-aromatic 5-membered heterocyclic group, or a non-aromatic 6-membered heterocyclic group. It represents a cyclic group, a pyridine residue, a pyrazine residue or the general formula (4).

Examples of the aliphatic group, alkoxycarbonyl group, aryloxycarbonyl group, and aryl group represented by R ₃ include the aliphatic group, alkoxycarbonyl group, and aryloxycarbonyl group represented by R in the general formula (1). And examples given as specific examples of the aryl group.

Specific examples of the aromatic or non-aromatic 5-membered heterocyclic group represented by R ₃ include pyrrole, thiophene, furan, imidazole, thiazole, oxazole, pyrazole, isothiazole, thiazoline, piperidine, triazole, pyrrolidine, and pyrazolidine. , Residues such as imidazolidine, isoxazolidine, isothiazolidine and the like.

  Specific examples of the non-aromatic 6-membered heterocyclic group represented by R3 include residues such as piperidine, piperazine, morpholine and thiomorpholine.

R ₃ is preferably a residue of pyrrole, thiophene, furan, imidazole, thiazole, oxazole, pyrazole, thiazoline, piperidine, pyrrolidine, pyrazolidine, piperidine, piperazine, pyridine, pyrazine, pyrrole, thiophene, furan, imidazole, pyrazole, Residues of thiazoline, piperidine, pyrrolidine, pyridine and pyrazine are more preferred, and residues of imidazole, pyrazole, thiazoline, pyridine and pyrazine are particularly preferred.

In the general formula (4), R ₄ represents an aliphatic group, an aryl group, or a heterocyclic group. W is ═NR ₅ , an oxygen atom, or a sulfur atom. R ₅ represents a hydrogen atom or a substituent.

Specific examples of the aliphatic group, aryl group and heterocyclic group represented by R ₄ include those of the aliphatic group, aryl group and heterocyclic group used for the substituent represented by R in the general formula (1). Examples are given.

R ₅ is preferably a hydrogen atom. W is preferably ═NH or an oxygen atom.

  Although the specific example of a compound represented by General formula (1), General formula (2), and General formula (3) below is given, this invention is not limited to these.

  The synthesis of the compound represented by the general formula (1), the general formula (2), or the general formula (3) is described in J. of American Chem. Soc. Vol. 125, 2003, 15128-15139. Page) or JP-T-2004-526986 and the like.

  Specifically, as a general synthesis method, a method of reacting an isocyanate and an amino group to obtain a urea bond can be mentioned.

  The isocyanate used as the raw material is not particularly limited as long as it is a polyisocyanate having two or more isocyanate groups in the molecule. Alkyl polyisocyanates or aromatic polyisocyanates are preferred, and alkyl diisocyanates or aromatic diisocyanates are more preferred.

  Specific examples of the alkyl polyisocyanate include 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, and 1,3-cyclopentane diisocyanate. Etc.

  An aromatic polyisocyanate is a compound in which a plurality of isocyanate groups are all directly bonded to an aromatic ring. For example, 9H-fluorene-2,7-diisocyanate, 9H-fluoren-9-one-2,7- Diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 1,3-bis (isocyanatomethyl) ) Cyclohexane, 2,2-bis (4-isocyanatophenyl) hexafluoropropane, 1,5-diisocyanatonaphthalene and the like.

  The amine used as a raw material may be a compound having an amino group and a hydrogen bondable functional group in the molecule, and an alkylamine having a hydrogen bondable functional group such as a nitrogen atom, a sulfur atom or an oxygen atom in the molecule. Or an aromatic amine is preferable.

  Specific examples of the alkylamine having a hydrogen bonding functional group include butylthiomethylamine, (2-ethoxyethoxy) methylamine, ethyl carbamate, 1-butylurea, N-butylmethylamine, ethylenediamine, hexamethylenediamine and the like. Can be mentioned. Preferably, it is a C1-C10 alkylamine.

  Specific examples of the aromatic amine having a hydrogen bonding functional group include aminopyridine, aminopyrimidine, aminopyrazolone, aminothiazole, aminooxazole, aminoimidazole, aminothiazolone, aminooxazolone, aminopyridazine, aminopyrazine, aminopyrrole, amino Examples include, but are not limited to, thiophene, aminofuran, aminoimidazolone, aminothiazolone, aminooxazolone, aminoimidazoline, aminothiazoline, aminooxazoline, aminopyrazoline, aminoisothiazoline, aminoisoxazoline.

  Preferred are aminopyridine, aminopyrimidine, aminoimidazolone, aminopyrazoline and aminothiazoline, and more preferred are aminopyridine, aminopyrimidine and aminothiazoline.

  Although the synthesis example of exemplary compound A-14 and A-12 is shown below, this invention is not limited to these.

4.3 g (45 mmol) of aminopyridine and 4.0 g (18 mmol) of isophorone diisocyanate were dissolved in 50 ml of ethyl acetate and heated to 80 degrees. After stirring for 2 hours, the mixture was allowed to cool and the precipitated solid was filtered off. The obtained solid was purified by recrystallization from methanol and water, and dried to obtain 6.5 g of the desired product. Yield 88%. Melting | fusing point is 241-242 degreeC and the measurement result of 1H-NMR is as follows.
1H-NMR (400 MHz, TMS, dimethylformamide-d6): 0.90 to 1.24 (13H, m), 1.66 (2H, m), 2.98 (2H, m), 3.89 (1H M), 6.91 (2H, dd), 7.34 (2H, dd), 7.64 (2H, q), 9.11 (2H, d)

4.6 g (45 mmol) of 2-aminothiazoline and 4.0 g (18 mmol) of isophorone diisocyanate were dissolved in 50 ml of ethyl acetate and heated to 80 degrees. After stirring for 1 hour, the mixture was allowed to cool and the precipitated solid was filtered off. The obtained solid was purified by recrystallization from methanol and water and dried to obtain 6.1 g of the desired product. Yield 80%. Melting | fusing point is 209-210 degreeC, and the measurement result of 1H-NMR is as follows.
1H-NMR (400 MHz, TMS, dimethylformamide-d6): 0.82 to 1.63 (13H, m), 1.57 (2H, m), 2.93 (2H, d), 3.15 (4H) , Dd), 4.03 (2H, dd), 9.04 (1H, s), 9.10 (1H, s), 9.79 (1H, m), 10.02 (1H, m)
In the present invention, the compound represented by the general formula (1) is contained in the image forming layer. The image forming layer preferably contains an alkali-soluble resin as described below. In this case, the image forming layer preferably contains 0.1 to 30% by mass of the compound represented by the general formula (1) with respect to the alkali-soluble resin from the viewpoint of the solubility and chemical resistance of the resin. Is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass.

(Lithographic printing plate materials)
(Support)
The support according to the present invention is a plate or film that can carry the image forming layer, and a known material used as a substrate such as a printing plate can be used.

  For example, a metal plate, a plastic film, paper treated with a polyolefin, a composite base material obtained by appropriately bonding the above materials, and the like can be given.

  The thickness of the support is not particularly limited, but 10 μm to 1 mm is easy to handle. For example, in the case of a printing plate material, 50 to 500 μm is generally easy to handle.

  Examples of the metal plate used as the support include iron, stainless steel, aluminum and the like, and an aluminum support is particularly preferable from the relationship between specific gravity and rigidity. The aluminum support is a pure aluminum plate or an aluminum alloy plate.

  Various aluminum alloys can be used, for example, alloys of aluminum and metals such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, titanium, sodium, iron, etc. An aluminum plate produced by the method can be used. In addition, a recycled aluminum plate obtained by rolling recycled aluminum ingots such as scrap materials and recycled materials that are becoming popular in recent years can also be used.

  The aluminum support preferably has a roughened surface. Prior to roughening (graining treatment), it is preferable to perform a degreasing treatment in order to remove the rolling oil on the surface. As the degreasing treatment, a degreasing treatment using a solvent such as trichlene or thinner, an emulsion degreasing treatment using an emulsion such as kesilon or triethanol, or the like is used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, dirt and oxide film that cannot be removed only by the degreasing treatment can be removed. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, smut is generated on the surface of the support. In this case, the substrate is immersed in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid, or a mixed acid thereof and desmutted. It is preferable to perform the treatment.

  Next, a roughening process is performed. Examples of the roughening method include a mechanical method and a method of etching by electrolysis. In the present invention, AC electrolytic surface roughening treatment in an electrolytic solution mainly composed of hydrochloric acid is preferable, but prior to that, mechanical surface roughening treatment and electrolytic surface roughening treatment mainly composed of nitric acid may be performed.

After the surface is roughened by the mechanical surface roughening method, it is preferable to immerse in an aqueous solution of acid or alkali in order to remove the abrasive that has digged into the surface of the support, formed aluminum scraps, and the like. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like. Examples of the base include sodium hydroxide and potassium hydroxide. Among these, it is preferable to use an aqueous alkali solution such as sodium hydroxide. The amount of aluminum dissolved on the surface is preferably 0.5 to 5 g / m ² . After the immersion treatment with an alkaline aqueous solution, it is preferable to carry out a neutralization treatment by immersion in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid or a mixed acid thereof.

The electrolytic surface-roughening treatment mainly composed of nitric acid can be generally performed by applying a voltage in the range of 1 to 50 volts, but is preferably selected from the range of 10 to 30 volts. Current density may be in the range of 10 to 200 A / dm ^2, preferably selected from the range of 20 to 100 A / dm ^2. Quantity of electricity, may be in the range of 5000 C / dm ^2, preferably selected from the range of 100~2000C / dm ^2. The temperature at which the electrochemical roughening method is performed can be in the range of 10 to 50 ° C, but is preferably selected from the range of 15 to 45 ° C. The concentration of nitric acid in the electrolytic solution is preferably 0.1 to 5% by mass. If necessary, nitrates, chlorides, amines, aldehydes, phosphoric acid, chromic acid, boric acid, acetic acid, oxalic acid, aluminum ions, and the like can be added to the electrolytic solution.

After the electrolytic surface-roughening treatment mainly composed of nitric acid, it is preferably immersed in an acid or alkali aqueous solution in order to remove aluminum scraps on the surface. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like. Examples of the base include sodium hydroxide and potassium hydroxide. Among these, it is preferable to use an alkaline aqueous solution. The amount of aluminum dissolved on the surface is preferably 0.5 to 5 g / m ² . In addition, it is preferable that after the immersion treatment with an alkaline aqueous solution, neutralization treatment is performed by immersion in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid or a mixed acid thereof.

In the AC electrolytic surface roughening treatment in an electrolytic solution mainly composed of hydrochloric acid, the hydrochloric acid concentration is 5 to 20 g / l, preferably 6 to 15 g / l. The current density is 15 to 120 A / dm ² , preferably 20 to 90 A / dm ² . The quantity of electricity was 400~2000C / dm ^2, preferably 500~1200C / dm ^2. The frequency is preferably in the range of 40 to 150 Hz. The temperature of the electrolytic solution can be in the range of 10 to 50 ° C, but is preferably selected from the range of 15 to 45 ° C. If necessary, nitrates, chlorides, amines, aldehydes, phosphoric acid, chromic acid, boric acid, acetic acid, oxalic acid, aluminum ions, and the like can be added to the electrolytic solution.

After the electrolytic surface roughening treatment is performed in the above-described electrolytic solution mainly composed of hydrochloric acid, it is preferably immersed in an aqueous solution of acid or alkali in order to remove aluminum scraps on the surface. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like. Examples of the base include sodium hydroxide and potassium hydroxide. Among these, it is preferable to use an alkaline aqueous solution. The amount of aluminum dissolved on the surface is preferably 0.5 to ² g / m ² . In addition, it is preferable that after the immersion treatment with an alkaline aqueous solution, neutralization treatment is performed by immersion in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid or a mixed acid thereof.

Following the roughening treatment, an anodizing treatment is performed to form an anodized film. The anodizing method is preferably carried out using sulfuric acid or an electrolytic solution mainly composed of sulfuric acid as the electrolytic solution. The concentration of sulfuric acid is preferably 5 to 50% by mass, particularly preferably 10 to 35% by mass. The temperature is preferably 10 to 50 ° C. The treatment voltage is preferably 18V or more, and more preferably 20V or more. Current density is preferably 1~30A / dm ^2. Electrical weight is preferably 200~600C / dm ^2.

The formed anodic oxidation coating amount is preferably ² to 6 g / m ² , and preferably 3 to 5 g / m ² . The anodic oxidation coating amount is obtained by, for example, immersing an aluminum plate in a chromic phosphate solution (produced by dissolving 85% phosphoric acid solution: 35 ml, chromium oxide (IV): 20 g in 1 L of water), dissolving the oxide coating, It is calculated | required from the mass change measurement etc. before and after melt | dissolution of the coating. Micropores are generated in the anodized film, and the density of the micropores is preferably 400 to 700 / μm ^{2, and} more preferably 400 to 600 / μm ² .

  The anodized support may be sealed as necessary. These sealing treatments can be performed using known methods such as hot water treatment, boiling water treatment, water vapor treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment, and ammonium acetate treatment.

(Positive image forming layer)
The planographic printing plate material according to the present invention has a positive image forming layer on a support.

  The positive image forming layer is an image forming layer in which an exposed portion becomes a non-image portion at the time of printing and an unexposed portion becomes an image portion at the time of printing by image exposure.

  The positive type image forming layer according to the present invention preferably contains an alkali-soluble resin because the effect of the present invention is great, and it is particularly preferable that a photothermal conversion compound, an acid generator and an acid-decomposable compound are included.

(Alkali-soluble resin)
The alkali-soluble resin according to the present invention is a resin that dissolves in an aqueous potassium hydroxide solution having a pH of 13 at 25 g at 0.1 g / l or more.

  As the alkali-soluble resin, a novolak resin, an acrylic resin, or an acetal resin is preferably used from the viewpoint of ink inking property, alkali solubility, and the like.

  The alkali-soluble resin may have a single configuration, but may be a combination of two or more.

(Novolac resin)
The novolak resin is synthesized by condensing various phenols with aldehydes.

  Phenols include phenol, m-cresol, p-cresol, m- / p-mixed cresol, phenol and cresol (m-, p-, or m- / p-mixed), pyrogallol, phenol group Examples thereof include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene.

  In addition, substituted phenols such as isopropylphenol, t-butylphenol, t-amylphenol, hexylphenol, cyclohexylphenol, 3-methyl-4-chloro-6-t-butylphenol, isopropylcresol, t-butylcresol, and t-amylresole. Is mentioned. Preferably, t-butylphenol and t-butylcresol can also be used. On the other hand, examples of aldehydes include aliphatic and aromatic aldehydes such as formaldehyde, acetaldehyde, acrolein, and crotonaldehyde. Preferred is formaldehyde or acetaldehyde, and most preferred is formaldehyde.

  Among the above combinations, preferably phenol-formaldehyde, m-cresol-formaldehyde, p-cresol-formaldehyde, m- / p-mixed cresol-formaldehyde, phenol / cresol (m-, p-, o-, m- / Any of p-mixing, m- / o-mixing and o- / p-mixing.) Mixed-formaldehyde. Particularly preferred is cresol (m-, p-mixed) -formaldehyde.

  These novolak resins preferably have a weight average molecular weight of 1,000 or more and a number average molecular weight of 200 or more. More preferably, the weight average molecular weight is 1,500 to 300,000, the number average molecular weight is 300 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10. . Particularly preferably, the weight average molecular weight is 2,000 to 10,000, the number average molecular weight is 500 to 10,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 5. . By setting it as the above range, the film strength, alkali solubility, chemical solubility, interaction property with the photothermal conversion substance, etc. of the novolak resin can be appropriately adjusted, and the effects of the present invention can be easily obtained. The weight average molecular weight of the novolak resin can be adjusted in the upper layer and the lower layer. Since the upper layer is required to have chemical resistance, film strength, etc., the relatively high weight average molecular weight is preferably 2,000 to 10,000.

  In addition, a weight average molecular weight is the value of polystyrene conversion calculated | required by the gel permeation chromatography (GPC) method which uses the monodisperse polystyrene of a novolak resin as a standard.

  As a method for producing a novolak resin, for example, as described in “New Experimental Chemistry Course [19] Polymer Chemistry [I]” (1993, Maruzen Publishing), Item 300, phenol and substituted phenols (for example, xylenol) , Cresols, etc.) in a solvent using acid as a catalyst together with an aqueous formaldehyde solution to dehydrate and condense phenol, the o-position or p-position of the substituted phenol component, and formaldehyde. After dissolving the novolak resin thus obtained in an organic polar solvent, an appropriate amount of a nonpolar solvent is added and left for several hours, whereby the novolak resin solution is separated into two layers. By concentrating only the lower layer of the separated solution, a novolak resin with a concentrated molecular weight can be produced.

  Examples of the organic polar solvent used include acetone, methyl alcohol, and ethyl alcohol. Examples of the nonpolar solvent include hexane and petroleum ether. In addition to the production method described above, for example, as described in JP-T-2001-506294, a novolak resin is dissolved in a water-soluble organic polar solvent, and then water is added to form a precipitate. A novolak resin fraction can also be obtained. Further, in order to obtain a novolak resin having a low degree of dispersion, it is possible to use a method in which a novolak resin obtained by dehydration condensation of phenol derivatives is dissolved in an organic polar solvent and then applied to a silica gel for molecular weight fractionation.

  The dehydration condensation between the o-position or p-position of the phenol and the substituted phenol component and formaldehyde gives a concentration of 60 to 90% by mass, preferably 70 to 80% by mass as the total mass of the phenol and the substituted phenol component. In the solvent solution, the molar ratio of formaldehyde to the total number of moles of phenol and substituted phenol components is 0.2 to 2.0, preferably 0.4 to 1.4, particularly preferably 0.6 to 1.2. In addition, the acid catalyst has a molar ratio with respect to the total number of moles of phenol and substituted phenol components of 0.01 to 0.1, preferably 0.02 to 0.05. It can be performed by adding under temperature conditions and stirring for several hours while maintaining the temperature range. In addition, it is preferable that reaction temperature is the range of 70 to 150 degreeC, and it is more preferable that it is the range of 90 to 140 degreeC.

  A novolac resin may be used independently and may use 2 or more types together. By combining two or more kinds, it is possible to effectively use different characteristics such as film strength, alkali solubility, solubility in chemicals, and interaction with a photothermal conversion substance, which is preferable. When two or more kinds of novolak resins are used in combination in the image recording layer, it is preferable to combine those having as much difference as possible, such as weight average molecular weight and m / p ratio. For example, the difference in weight average molecular weight is preferably 1000 or more, and more preferably 2000 or more. The m / p ratio preferably has a difference of 0.2 or more, more preferably 0.3 or more.

  The addition amount of the resin having a phenolic hydroxyl group in the lithographic printing plate material of the present invention is preferably 30 to 99% by mass with respect to the solid content of the upper layer from the viewpoint of chemical resistance and printing durability. More preferably, it is 95 mass%, and it is most preferable that it is the range of 60-90 mass%.

(acrylic resin)
The acrylic resin is preferably a copolymer containing the following structural units. Other structural units that can be suitably used include, for example, acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, maleic Examples thereof include structural units introduced from known monomers such as acid imides and lactones.

  Specific examples of acrylates that can be used include methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec- or t-) butyl acrylate, amyl acrylate, 2 -Ethylhexyl acrylate, dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl Acrylate, methoxybenzyl acrylate, chlorobenzyl acrylate, 2- (p-hydroxyphenyl) ethyl acetate Rate, furfuryl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, chlorophenyl acrylate, sulfamoyl phenyl acrylate, and the like.

  Specific examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, (n- or i-) propyl methacrylate, (n-, i-, sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate, Dodecyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, methoxybenzyl methacrylate, chloro Benzyl methacrylate, 2- (p-hydroxyphenyl) ethyl methacrylate Rate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate and the like.

  Specific examples of acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, and N-tolylacrylamide. N- (p-hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl) acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-N- Examples include phenylacrylamide, N-hydroxyethyl-N-methylacrylamide, N- (p-toluenesulfonyl) acrylamide and the like.

  Specific examples of methacrylamides include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-butylmethacrylamide, N-benzylmethacrylamide, N-hydroxyethylmethacrylamide, N -Phenylmethacrylamide, N-tolylmethacrylamide, N- (p-hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N- (tolylsulfonyl) methacrylamide N, N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N- (p-toluenesulfonyl) methacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like.

  Specific examples of lactones include pantoyl lactone (meth) acrylate, α- (meth) acryloyl-γ-butyrolactone, and β- (meth) acryloyl-γ-butyrolactone.

  Specific examples of maleic imides include maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide and the like.

  Specific examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate and the like.

  Specific examples of styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, propyl styrene, cyclohexyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, dimethoxy styrene. Chlorostyrene, dichlorostyrene, bromostyrene, iodostyrene, fluorostyrene, carboxystyrene and the like.

  Specific examples of acrylonitriles include acrylonitrile and methacrylonitrile.

  Among these monomers, acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, acrylic acid, methacrylic acid, acrylonitriles, maleic imides having 20 or less carbon atoms are particularly preferably used. is there.

  The molecular weight of the copolymer using these is preferably 2000 or more in terms of weight average molecular weight (Mw), more preferably in the range of 50,000 to 100,000, and particularly preferably in the range of 10,000 to 50,000. By making it into the above range, the film strength, alkali solubility, solubility in chemicals, etc. can be adjusted, and the effects of the present invention can be easily obtained.

  The polymerization form of the acrylic resin may be any of random polymer, block polymer, graft polymer, etc., but is a block polymer capable of phase separation of hydrophilic group and hydrophobic group in that the solubility of developer can be controlled. Is preferred.

  An acrylic resin may be used independently or may be used in mixture of 2 or more types.

(Acetal resin)
The polyvinyl acetal resin can be synthesized by a method in which polyvinyl alcohol is acetalized with an aldehyde and the remaining hydroxy group is reacted with an acid anhydride.

  Examples of the aldehyde used herein include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, pentylaldehyde, hexylaldehyde, glyoxylic acid, N, N-dimethylformamide di-n-butyl acetal, bromoacetaldehyde, chloroacetaldehyde, 3-hydroxy- Examples include, but are not limited to, n-butyraldehyde, 3-methoxy-n-butyraldehyde, 3- (dimethylamino) -2,2-dimethylpropionaldehyde, cyanoacetaldehyde, and the like.

  As the acetal resin, a polyvinyl acetal resin represented by the following general formula (PVAC) is preferably used.

  In general formula (PVAC), n1 represents 5-85 mol%, n2 represents 0-60 mol%, and n1 represents 0-60 mol%.

  The structural unit (i) is a group derived from polyvinyl acetal, the structural unit (ii) is a group derived from polyvinyl alcohol, and the structural unit (iii) is a group derived from a vinyl ester.

In the structural unit (i), R ¹ represents an alkyl group which may have a substituent, a hydrogen atom, a carboxyl group, or a dimethylamino group.

Examples of the substituent include a carboxyl group, a hydroxyl group, a chloro group, a bromo group, a urethane group, a ureido group, a tertiary amino group, an alkoxy group, a cyano group, a nitro group, an amide group, and an ester group. Specific examples of R ¹ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a carboxy group, a halogen atom (—Br, —Cl, etc.) or a methyl group substituted with a cyano group, 3 -Hydroxybutyl group, 3-methoxybutyl group, phenyl group and the like can be mentioned, among which hydrogen atom, propyl group and phenyl group are particularly preferable.

  In the structural unit (ii), n2 is in the range of 0 to 60 mol%, and more preferably in the range of 10 to 45 mol%. This structural unit (ii) is excellent in affinity to water, but if the value of n2 is in the range of 0 to 60 mol%, the swelling property to water can be maintained appropriately and the printing durability can be kept good.

In the structural unit (iii), R ² represents an alkyl group having no substituent, an aliphatic hydrocarbon group having a carboxyl group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group. The hydrogen group represents 1 to 20 carbon atoms. Among these, an alkyl group having 1 to 10 carbon atoms is preferable, and a methyl group and an ethyl group are particularly preferable from the viewpoint of developability. n3 is preferably in the range of 0 to 20 mol%, more preferably in the range of 1 to 10 mol% from the viewpoint of printing durability.

  The acid content of the polyvinyl acetal resin is preferably in the range of 0.5 to 5.0 meq / g (that is, 84 to 280 in terms of mg of KOH) in terms of sensitivity and development latitude, and is preferably 1.0 to 3 More preferably, it is 0.0 meq / g.

  The molecular weight of the polyvinyl acetal resin is preferably about 5,000 to 400,000, more preferably about 20,000 to 300,000, as a weight average molecular weight measured by gel permeation chromatography. By making it into the above range, the film strength, alkali solubility, solubility in chemicals, etc. can be adjusted, and the effects of the present invention can be easily obtained.

  In addition, these polyvinyl acetal resins may be used independently or may be used in mixture of 2 or more types.

  Acetalization of polyvinyl alcohol can be carried out according to known methods, for example, US Pat. No. 4,665,124; US Pat. No. 4,940,646; US Pat. No. 5,169,898; US Pat. No. 5,700,809; US Pat. No. 5,792,823; No. 09328519 and the like.

  The planographic printing plate material according to the present invention may have a plurality of image forming layers. In this case, for example, in the case of having two layers of the lower layer and the upper layer of the image forming layer, the alkali-soluble resin used for the lower layer is preferably mainly an acrylic resin or an acetal resin in terms of alkali solubility, etc. As the alkali-soluble resin used in the ink, a novolak resin is preferable from the viewpoint of ink inking property.

(Photothermal conversion agent)
The photothermal conversion agent has a light absorption range in the infrared region of 700 nm or more, preferably 750 to 1200 nm, and expresses the light / heat conversion ability in the light of this wavelength range. Various pigments or dyes that absorb light in the region and generate heat can be used.

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

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used.

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm.

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

  The pigment is added in a proportion of 0.01 to 10% by mass, preferably 0.1 to 5% by mass, based on the total solid content constituting the photosensitive layer, from the viewpoints of sensitivity, uniformity of the photosensitive layer and durability. Can do.

(dye)
As the dye, commercially available dyes and known dyes described in the literature (for example, “Dye Handbook” edited by Organic Synthetic Chemical Society, published in 1970) can be used. Specific examples include azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes. In the present invention, among these pigments or dyes, those that absorb infrared light or near infrared light are particularly preferred because they are suitable for use in lasers that emit infrared light or near infrared light.

  Examples of dyes that absorb such infrared light or near infrared light include, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, and JP-A-60-78787. Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, etc., JP-A-58-112793, Naphthoquinone dyes described in JP-A-58-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. Examples thereof include squarylium dyes described in 58-112792 and cyanine dyes described in British Patent 434,875. Further, near-infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used as dyes, and substituted arylbenzo (thio) pyrylium described in US Pat. No. 3,881,924. Salts, trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59 -84248, 59-84249, 59-146063, 59-146061, pyrylium compounds described in JP-A-59-216146, cyanine dyes described in U.S. Pat. No. 4,283,475 Pentamethine thiopyrylium salt described in No. 5 and pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702, E olight III-178, Epolight III-130, Epolight III-125 and the like are particularly preferably used.

  Particularly preferred among these dyes are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes.

  Specific examples of the cyanine dye include paragraph numbers [0017] to [0019] of JP-A No. 2001-133969, paragraph numbers [0012] to [0038] of JP-A No. 2002-40638, and JP-A No. 2002-23360. And those described in paragraph numbers [0012] to [0023] of the Japanese Patent Publication.

  From the viewpoint of sensitivity, chemical resistance, and printing durability, the infrared absorbing dye is 0.01 to 30% by mass, preferably 0.1 to 10% by mass, particularly preferably the total solid content constituting the image forming layer. It can add in the ratio of 0.1-5 mass%.

(Acid generator)
The acid generator is a compound capable of generating an acid upon image exposure, and includes various known compounds and mixtures.

For example, diazonium, phosphonium, sulfonium and iodonium salts such as BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , ClO ₄ ⁻ , organohalogen compounds, orthoquinone-diazidosulfonyl chloride, and organometallic / organic Halogen compounds can also be used as the acid generator in the present invention. In addition, compounds that generate photosulfonic acid by photolysis, such as iminosulfonates described in JP-A-4-365048, etc., disulfone compounds described in JP-A-61-166544, JP-A-50- O-naphthoquinonediazide-4-sulfonic acid halide described in US Pat. No. 36209 (US Pat. No. 3,969,118), o-naphthoquinonediazide described in JP-A-55-62444 (UK Patent No. 2038801) or JP-B-1-11935 A compound can be mentioned. Examples of other acid generators include sulfonic acid alkyl esters such as cyclohexyl citrate, p-acetaminobenzene sulfonic acid cyclohexyl ester, p-bromobenzene sulfonic acid cyclohexyl ester, and alkyl sulfonic acid esters.

  Examples of the above-mentioned compounds forming hydrohalic acid include U.S. Pat. Nos. 3,515,552, 3,536,489 and 3,779,778, and West German Patent Publication No. 2, Examples thereof include those described in US Pat. No. 243,621, and compounds capable of generating an acid by photolysis described in, for example, West German Patent Publication No. 2,610,842 can also be used. Further, o-naphthoquinonediazide-4-sulfonic acid halogenide described in JP-A-50-36209 can be used.

  As the organic halogen compound, triazines having a halogen-substituted alkyl group and oxadiazoles having a halogen-substituted alkyl group are preferable, and s-triazines having a halogen-substituted alkyl group are particularly preferable. Specific examples of oxadiazoles having a halogen-substituted alkyl group include JP 54-74728, JP 55-24113, JP 55-77742, JP 60-3626 and JP 60-3626. And 2-halomethyl-1,3,4-oxadiazole compounds described in JP-A-60-138539.

  In the present invention, the following acid generators can also be used. For example, a polymerization initiator described in JP-A-2005-70211, a compound capable of generating radicals described in JP-A-2002-537419, JP-A-2001-175006, JP-A-2002-278057, JP-A-2003-2003 In addition to the polymerization initiator described in JP-A-5363, an onium salt described in JP-A-2003-76010 having two or more cation moieties in one molecule, N- Nitrosamine compounds, compounds that generate radicals with heat according to JP-A-2001-343742, compounds that generate acids or radicals with heat according to JP-A-2002-6482, borate compounds according to JP-A-2002-116539, JP-A-2002 Compound which generates an acid or a radical by heat described in JP-A-148790, No. 02-207293, a photo- or thermal-polymerization initiator having a polymerizable unsaturated group, JP-A No. 2002-268217, an onium salt having a divalent or higher anion as a counter ion, JP-A No. 2002-328465 Compounds such as a specific structure sulfonyl sulfone compound and a compound that generates radicals by heat described in JP-A No. 2002-341519 can be used as necessary.

  Among these, the compound represented by the following general formula (A) is preferable. This compound has particularly good safelight properties and is particularly preferable.

Formula (A) R ³¹ —C (X) ₂ — (C═O) —R ³²
In the formula, R ³¹ represents a hydrogen atom, bromine atom, chlorine atom, alkyl group, aryl group, acyl group, alkylsulfonyl group, arylsulfonyl group, iminosulfonyl group or cyano group. R ³² represents a hydrogen atom or a monovalent organic substituent. R ³¹ and R ³² may combine to form a ring. X represents a bromine atom or a chlorine atom.

Of the compounds represented by the general formula (A), those in which R ³¹ is a hydrogen atom, a bromine atom or a chlorine atom are preferably used from the viewpoint of sensitivity. The monovalent organic substituent represented by R ³² is not particularly limited as long as the compound of the general formula (A) generates a radical by light, but —R ³² is —O—R ³³ or —NR. ³⁴ -R ³³ (R ³³ represents a hydrogen atom or a monovalent organic substituent, and R ³⁴ represents a hydrogen atom or an alkyl group) is preferably used. Also in this case, in particular, those in which R ³¹ is a hydrogen atom, a bromine atom or a chlorine atom are preferably used from the viewpoint of sensitivity.

  Further, among these compounds, compounds having at least one acetyl group selected from a tribromoacetyl group, a dibromoacetyl group, a trichloroacetyl group and a dichloroacetyl group in the molecule are preferable. Further, from the viewpoint of synthesis, at least one selected from a tribromoacetoxy group, a dibromoacetoxy group, a trichloroacetoxy group and a dichloroacetoxy group, which is obtained by reacting a monovalent or polyvalent alcohol with the corresponding acid chloride. Tribromoacetylamide group, dibromoacetylamide group, trichloroacetylamide group and dichloroacetyl obtained by the reaction of a compound having an acetoxy group or a monovalent or polyvalent primary amine with the corresponding acid chloride. A compound having at least one acetylamide group selected from amide groups is particularly preferred. Further, compounds having a plurality of these acetyl groups, acetoxy groups, and acetamide groups are also preferably used. These compounds can be easily synthesized under the conditions of ordinary esterification or amidation reaction.

  The acid generator may be a polymer having a group capable of generating an acid. It is preferable to use the acid generator as a polymer type because the effects of the alkali-soluble resin and the acid generator can function with one material. For example, by adding an acid-generating group to the above-mentioned acrylic resin, two or more effects such as chemical resistance, sensitivity due to the acid generator, and development latitude of the acrylic resin can be exhibited.

  The content of these acid generators is usually 0.1 to 30% by mass, more preferably 1 to 15% by mass, based on the total solid content of the image forming layer, in terms of sensitivity, development latitude, and safelight properties. is there. One acid generator may be used, or two or more acid generators may be mixed and used.

(Acid-decomposable compound)
An acid-decomposable compound is a compound that can be decomposed by an acid generated by an acid generator by image exposure.

  Specific examples of the acid-decomposable compound include JP-A-48-89003, JP-A-512072014, JP-A-53-133429, JP-A-51-212995, JP-A-55-126236, and JP-A-56-17345. Compounds having a C—O—C bond described in the document, compounds having a Si—O—C bond described in the specifications of JP-A-60-37549 and JP-A-60-121446, Other acid-decomposable compounds described in the specifications of Kokai 60-3625 and 60-10247 are mentioned.

  Furthermore, compounds having a Si—N bond described in the specification of JP-A-62-222246, carbonate esters described in the specification of JP-A-62-251743, and JP-A-62-2 The ortho carbonate ester described in the specification of No. 209451, the ortho titanate ester described in the specification of JP-A No. 62-280842, and the specification of JP-A No. 62-280842 are described. Orthosilicate esters, acetals and ketals described in the specification of JP-A No. 2000-221676, compounds having a C—S bond described in the specification of JP-A No. 62-244038, Phenolphthalein, cresolphthalein and phenolsulfophthalein described in Kaikai 2005-91802 were protected with heat or acid-decomposable groups. Such compounds, and the like.

  Among these, compounds having at least one acetal or ketal group are preferred from the viewpoint of improving reaction efficiency with acid, that is, sensitivity and development latitude.

Also in terms of sensitivity and developability of the _{balance, - (CH 2 CH 2 O} ) n- group (n is an integer of 2 to 5) include compounds having the. Among these compounds, compounds having an ethyleneoxy group chain number n of 3 or 4 are preferred. Specific examples of the compound having the — (CH ₂ CH ₂ O) n— group include condensation production of dimethoxycyclohexane, benzaldehyde and substituted derivatives thereof and any of diethylene glycol, triethylene glycol, tetraethylene glycol and pentaethylene glycol. Things.

(Visible paint)
The image forming layer according to the present invention preferably contains a colorant as a visible image agent. Examples of the colorant include oil-soluble dyes and basic dyes including salt-forming organic dyes.

  Particularly preferred are those that change color tone by reacting with free radicals or acids. “Color tone changes” includes both a change from colorless to colored color tone and a change from colored to colorless or different colored tone. Preferred dyes are those that change color tone by forming a salt with an acid.

(Development accelerator)
The image forming layer according to the present invention may contain a compound having a low molecular weight acidic group as a development accelerator for the purpose of improving the solubility as required.

  Examples of the acidic group include acidic groups having a pKa value of 7 to 11, such as a thiol group, a phenolic hydroxyl group, a sulfonamide group, and an active methylene group. The addition amount is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass with respect to the lower layer.

(Development inhibitor)
The image forming layer according to the present invention may contain various dissolution inhibitors for the purpose of adjusting solubility. As the dissolution inhibitor, a disulfone compound or a sulfone compound as disclosed in JP-A-11-119418 is preferably used, and as a specific example, it is preferable to use 4,4′-bishydroxyphenylsulfone. The addition amount is preferably 0.05 to 20% by mass, more preferably 0.5 to 10% by mass with respect to each layer.

  In addition, a development inhibitor can be contained for the purpose of enhancing dissolution inhibiting ability. The development inhibitor according to the present invention forms an interaction with the alkali-soluble resin, substantially lowers the solubility of the alkali-soluble resin in a developing solution in an unexposed area, and There is no particular limitation as long as the interaction is weakened and can be soluble in the developer, but quaternary ammonium salts, polyethylene glycol compounds and the like are particularly preferably used.

  Although it does not specifically limit as a quaternary ammonium salt, A tetraalkyl ammonium salt, a trialkyl aryl ammonium salt, a dialkyl diaryl ammonium salt, an alkyl triaryl ammonium salt, a tetraaryl ammonium salt, a cyclic ammonium salt, and a bicyclic ammonium salt are mentioned. .

  The addition amount of the quaternary ammonium salt is preferably 0.1 to 50% by mass and more preferably 1 to 30% by mass with respect to the total solid content of the upper layer from the viewpoint of the effect of suppressing development and film forming properties. preferable.

(Sensitivity improver)
The image forming layer according to the present invention may contain cyclic acid anhydrides, phenols, and organic acids for the purpose of improving sensitivity.

  Examples of cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy-Δ4-tetrahydrophthalic anhydride described in US Pat. No. 4,115,128, Tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used.

  As phenols, bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ', 4 "-Trihydroxytriphenylmethane, 4,4 ', 3", 4 "-tetrahydroxy-3,5,3', 5'-tetramethyltriphenylmethane and the like.

  Further, examples of organic acids include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphoric esters, and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755. Specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid Acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbine An acid etc. are mentioned. The proportion of the cyclic acid anhydride, phenols and organic acids in the composition is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, particularly preferably 0.1 to 10%. % By mass.

  Also, alcohol compounds in which at least one trifluoromethyl group described in JP-A-2005-99298 is substituted at the α-position can be used. This compound has the effect of improving the solubility in an alkali developer by improving the acidity of the α-position hydroxyl group due to the electron-withdrawing effect of the trifluoromethyl group.

  In the lithographic printing plate material according to the present invention, an image forming layer is formed by applying and drying an image forming layer coating solution containing the components contained in the positive type image forming layer on a support.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this. In the examples, “parts” represents “parts by mass” unless otherwise specified.

(Production of support)
An aluminum plate (material 1050, tempered H16) having a thickness of 0.24 mm was immersed in a 5% by mass sodium hydroxide aqueous solution at 50 ° C., and was subjected to a dissolution treatment so that the dissolution amount was 2 g / m ² and washed with water. Thereafter, it was immersed in a 10% by mass nitric acid aqueous solution at 25 ° C. for 30 seconds, neutralized, and then washed with water. Next, this aluminum plate was subjected to electrolytic surface roughening treatment with an electrolytic solution containing 11 g / L of hydrochloric acid, 10 g / L of acetic acid, and 8 g / L of aluminum using a sinusoidal alternating current at a current density of 70 A / dm ^2. went.

The distance between the electrode and the sample surface at this time was 10 mm. Perform electrolytic graining treatment is divided into 12 times, and the quantity of electricity used in one treatment (at a positive polarity) as the 80C / dm ^2, treatment quantity of electricity 960C / dm ² in total (at a positive polarity). Further, a pause time of 1 second was provided between each surface roughening treatment.

After electrolytic surface roughening, the surface is immersed in a 10% by mass phosphoric acid aqueous solution maintained at 50 ° C., etched so that the amount of dissolution including the smut of the roughened surface becomes 1.2 g / m ² , and washed with water. did. Next, anodization was performed in a 20% sulfuric acid aqueous solution so that the amount of electricity was 250 C / dm ² under a constant voltage condition of 20 V, followed by washing with water. Next, after squeezing the surface water after washing with water, it was immersed in a 2% by weight No. 3 sodium silicate aqueous solution maintained at 85 ° C. for 30 seconds, washed with water, and then 0.4% by weight polyvinylphosphonic acid (PVPA). It was immersed at 65 ° C. for 30 seconds and washed with water. The surface was squeezed and immediately heat-treated at 130 ° C. for 30 seconds to obtain a support.

The average roughness of the support was 0.50 μm as measured using SE1700α (Kosaka Laboratory Ltd.). The cell diameter of the support was 40 nm when observed with an SEM at a magnification of 100,000. The applied amount of polyvinylphosphonic acid was 10 mg / m ² .

(Preparation of multi-layer planographic printing plate material sample)
On the surface-treated support, a lower layer coating solution having the following composition was coated with a wire bar so as to be 1.0 g / m ² when dried, and dried at 120 ° C. for 90 seconds. Thereafter, an upper layer coating solution having the following composition was coated with a wire bar so as to be 0.4 g / m ² when dried, and dried at 120 ° C. for 60 seconds. Further, after cutting into a size of 670 mm × 560 mm, 200 sheets of the produced lithographic printing plate material were stacked with the interleaving paper P interposed therebetween. In this state, an aging treatment was performed for 24 hours under conditions of 55 ° C. and an absolute humidity of 0.037 kg / kg to prepare a lithographic printing plate material sample.

(Interleaf P)
Bleached kraft pulp was beaten, and 0.4% by mass of rosin-based sizing agent was added to the paper stock diluted to a concentration of 4%, and aluminum sulfate was added so that pH = 5. The paper stock was coated with 5.0% by weight of a paper strength agent containing starch as a main component, and papermaking was performed to prepare 40 g / m ² of interleaf paper P having a moisture content of 5%.

(Lower layer coating solution)
Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 4,000, containing 0.5% by mass of unreacted cresol) 5.0 parts by mass Compounds represented by general formula (1) (Table 1) 5.0 parts by weight Acrylic resin 1 68.0 parts by weight Crystal violet dye (Hodogaya Chemical Co., Ltd.) 0.8 parts by weight Acid-decomposed compound A 1.0 part by weight Acid-decomposed compound B 5.0 parts by weight Acid generation Agent: TAZ-101 (manufactured by Midori Chemical Co., Ltd.) 1.0 part by mass Acid generator: TAZ-107 (manufactured by Midori Chemical Co., Ltd.) 5.0 parts by mass Infrared absorbing dye (Dye 1) 3.0 parts by mass Tetrahydrophthalic anhydride 5.0 parts by mass Fluorosurfactant; Megafac F-178K (Dainippon Ink Chemical Co., Ltd.)
0.3 part by mass Solvent: γ-butyrolactone / methyl ethyl ketone / 1-methoxy-2-propanol (1/2/1) 908.9 parts by mass (upper layer coating solution)
Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 4,000, containing 0.5% by mass of unreacted cresol) 82.0 parts by mass A compound represented by the general formula (1) (Table 1) 10.0 parts by weight Acrylic resin 1 5.0 parts by weight Infrared absorbing pigment (dye 1) 6.0 parts by weight Photoacid generator: BR1 2.0 parts by weight Fluorosurfactant; MegaFac F-178K (Dainippon Ink Chemical Co., Ltd.)
1.0 part by mass Solvent: methyl ethyl ketone / 1-methoxy-2-propanol (1/2)
903.0 parts by mass

(Evaluation)
(sensitivity)
The obtained lithographic printing plate material was used with a commercially available CTP setter (PTR-4300 manufactured by Dainippon Screen Mfg. Co., Ltd.) equipped with a semiconductor laser (near infrared laser) head, with a drum rotation speed of 1000 rpm and a laser output of 30 to 100. %, Dot image exposure (near infrared laser exposure) corresponding to 175 lines was performed at a resolution of 2400 dpi (dpi represents the number of dots per 2.54 cm).

  The exposed lithographic printing plate material was developed at 30 ° C. for 20 seconds using an automatic developing machine (manufactured by Raptor 85 Thermal GLUNZ & JENSEN) and a developer having the following composition. The obtained image was measured with ccDot (manufactured by X-rite), and the exposure energy value (%) at which the 50% halftone dot output value was obtained was used as an index of sensitivity. The smaller the value, the higher the sensitivity.

<Developer>
A Potassium Silicate ((SiO ₂ : 26% by mass, K ₂ O: 13.5% by mass) 40% aqueous solution) manufactured by Nihon Kagaku Co., Ltd. 87.8 parts Caustic potash (50% aqueous solution) 61.1 parts manufactured by Toho Chemical Co., Ltd. Trilon M Liquid (40% aqueous solution) manufactured by BASF Corporation 1.4 parts pure water 1792 parts (pH = 12.9)
(Evaluation of development latitude)
The sensitivity evaluation was performed under the conditions of 26 ° C. and 20 seconds. The difference in sensitivity (Δ%) from the condition at 30 ° C. for 20 seconds was used as an index of development latitude. The smaller the value of the sensitivity difference Δ%, the better the development latitude.

(Scratch resistance)
The obtained lithographic printing plate material was left unexposed, and the surface was made to run with a needle having a diameter of 600 μm on which a 1 g weight was placed. Next, the film was developed at 32 ° C. for 30 seconds with an automatic developing machine (Raptor 85 Thermal GLUNZ & JENSEN) charged with the developer. The surface state of the image layer was visually evaluated according to the following evaluation criteria, and used as an index of scratch resistance.
Evaluation criteria:
5: No trace of the needle is seen in the image part 4: A slight decrease in density is observed, which seems to be a trace of the needle 3: A trace of the needle with a width of less than 20 μm is seen slightly (lowest practical level)
2: Traces of needles with a width of less than 20-50 μm are visible (not practical)
1: A trace of a needle having a width of 50 or more can be seen.

(chemical resistance)
A lithographic printing plate produced by exposing and developing an image of 175 lines at an exposure amount 1.3 times the sensitivity obtained above was developed using a printing machine Lithron manufactured by Komori Corporation, and coated paper, printing ink ( Printing was performed using soybean oil ink “Naturalis 100” manufactured by Dainippon Ink & Chemicals, Inc.) and dampening water (H liquid SG-51 concentration 1.5% manufactured by Tokyo Ink Co., Ltd.). The plate surface is wiped with a plate cleaner (Ultra Plate Cleaner (Distributor: Dainichi Seika Kogyo Co., Ltd.)) every 5,000 prints, and the number of printed sheets is chemical-resistant until a 3% dot loss occurs on the printed matter. It was used as an index. Larger numbers indicate better chemical resistance. The results of the evaluation are shown in Table 3.

(Preparation of single-layer planographic printing plate material sample)
On the surface-treated support, a coating solution for a single layer having the following composition was applied with a wire bar so as to be 1.5 g / m ² when dried, and dried at 120 ° C. for 90 seconds. Then, after cutting to a size of 670 mm × 560 mm, 200 sheets of the produced lithographic printing plate material were stacked with the interleaving paper P interposed therebetween. In this state, an aging treatment was performed for 24 hours under conditions of 55 ° C. and an absolute humidity of 0.037 kg / kg to prepare a lithographic printing plate material sample.

(Single layer coating solution)
60 parts by mass of novolak resin (* 1) * 1: Cocondensation compound of phenol, m-, p-mixed cresol and formaldehyde (Mn = 500, Mw = 2500, the molar ratio of phenol to m-, P-, cresol is 20:48:32 respectively)
Compound represented by general formula (1) (described in Table 2) 10.0 parts by mass Acrylic resin 2 (* 2) 14.7 parts by mass * 2: N- (p-hydroxyphenyl) maleimide, acrylonitrile and methyl methacrylate Ternary copolymer compound (Mw = 12000, molar ratio 50:40:10)
Acrylic resin 3 (* 3) 2 parts by mass * 3: copolymer compound of p-hydroxyphenyl methacrylate and tert-butoxycarbonylated-p-hydroxyphenyl methacrylate (Mw = 30000, molar ratio 60:40)
Polyethylene glycol (PEG # 4000) 2 parts by weight Sorbitan laurate 1 part by weight Phthalic anhydride 3 parts by weight Acid-decomposable compound A 2 parts by weight Acid generator (2- (p-methoxyphenyl) -4,6-bis (trichloro) Methyl) -s-triazine) 1 part by weight Infrared absorbing pigment (Dye 1) 2 parts by weight Visible dye (OIL BLUE 613, manufactured by Orient Chemical Industries) 2 parts by weight Fluorosurfactant; Megafac F-178K (Dainippon Ink) (Made by chemical industry)
1 part by weight Solvent (the following mixture) 1000 parts by weight γ-butyrolactone 7% by weight
Methyl ethyl ketone (MEK) 30% by mass
Propylene glycol monomethyl ether (Dow Chemical PM, Dowanol PM)
50% by mass
Cyclohexanone 13% by mass
(Solvent is added in a total amount of 1000 parts by mass)
(Evaluation)
The same evaluation as described above was performed. The results are shown in Table 4.

  From Tables 3 and 4, it can be seen that the lithographic printing plate material of the present invention is excellent in scratch resistance, excellent in sensitivity and development latitude, and excellent in chemical resistance.

Claims (8)

A lithographic printing plate material having a positive image forming layer on a support, wherein the positive image forming layer contains a compound represented by the following general formula (1).

[Wherein, J represents an n-valent group having no ureido group or ureylene group. n represents an integer of 2 to 4. R represents a substituent. ] The lithographic printing plate material according to claim 1, wherein J in the general formula (1) is an aliphatic group. The lithographic printing plate material according to claim 1 or 2, wherein R in the general formula (1) is a heterocyclic group. The lithographic printing plate material according to any one of claims 1 to 3, wherein R in the general formula (1) is a nitrogen-containing 5-membered cyclic group or a nitrogen-containing 6-membered cyclic group. The lithographic printing plate material according to any one of claims 1 to 4, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[Wherein R ₂ represents a substituent. ] The lithographic printing plate material according to any one of claims 1 to 4, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (3).

[Wherein, J represents a divalent group having no ureido group or ureylene group. R ₃ is an aliphatic group, alkoxycarbonyl group, aryloxycarbonyl group, aryl group, aromatic or non-aromatic 5-membered heterocyclic group, non-aromatic 6-membered heterocyclic group, pyridine residue, pyrazine residue, or The group represented by General formula (4) is represented.

In the formula, R ₄ represents an aliphatic group, an aryl group, or a heterocyclic group. W represents ═NR ₅ , an oxygen atom, or a sulfur atom. R ₅ represents a hydrogen atom or a substituent. ] The lithographic printing plate material according to any one of claims 1 to 6, wherein the positive-type image forming layer contains an alkali-soluble resin. The number of carbon atoms of the group represented by J in the general formula (1) is 20 or less, and the number of carbon atoms of the group represented by R is 20 or less. 2. The planographic printing plate material according to item 1.