JP2002264556A - Image forming material and original plate for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming material capable of suitably using a lithographic printing plate for scanning exposure conforming to a heat mode recording method, that is, the image forming material having a high sensitivity of an oscillation wavelength of a short-wavelength semiconductor laser and having good storage stability, exhibiting good on-press developability capable of developing with water or aqueous solution and further improving a plate wear resistance on a printing surface. SOLUTION: The image forming material comprises a polymer having at least one type of repeating units represented by formulae (I) to (III) each having specific structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel image forming material and a lithographic printing plate precursor. In addition, the present invention relates to an image forming material which can be suitably used as a lithographic printing plate precursor for scanning exposure which is particularly suitable for a CTP system excellent in workability and economy.

[0002]

2. Description of the Related Art In general, a lithographic printing plate comprises an oleophilic image area for receiving ink during a printing process and a hydrophilic non-image area for receiving fountain solution. Conventionally, as such a lithographic printing plate precursor, a PS plate in which a lipophilic photosensitive resin layer (ink receiving layer) is provided on a hydrophilic support is widely used. After exposure with a mask through a lith film, a non-image portion was dissolved and removed with a developing solution to obtain a desired printing plate.

[0003] In recent years, various new image output systems have been put into practical use corresponding to digitization technology for electronically processing image information using a computer. Along with this, computer-to-plate (CTP) technology, which scans actinic radiation having a high directivity such as laser light in accordance with digitized image information and directly manufactures a printing plate without passing through a lithographic film, has been desired. Therefore, it is an important technical problem to obtain a printing plate precursor adapted to this.

On the other hand, the plate making process in the conventional PS plate is as follows.
After the exposure, a step of dissolving and removing the non-image area by a wet process is indispensable, and this is another problem for which improvement is desired. Particularly in recent years, consideration for the global environment has become a major concern of the entire industry. The simplification of processing, dry processing, and non-processing are more important than before in terms of both environmental aspects and the streamlining of the process associated with the aforementioned digitization.
It has become highly desired.

[0005] From such a viewpoint, the following method has been proposed as one of the methods for eliminating the conventional processing steps. That is, using a photosensitive layer (image forming layer) capable of removing a non-image portion of a printing plate precursor in a normal printing process, exposing without exposure to a developing process, developing on a printing machine, There is an on-press development method for obtaining a typical printing plate. However, a major problem with the on-press development method is that the original
Since the photosensitive layer is not fixed, for example, there is a serious problem that the plate must be completely shielded from light and / or stored under constant temperature conditions until it is mounted on a printing press.

In response to the technical problems as described above, as a method of manufacturing a printing plate by scanning exposure, semiconductor lasers and YAs have recently been used.
Since high-power solid-state lasers such as G lasers have become available at low cost, methods using these lasers have been particularly promising. In the high power density exposure system using these high power lasers, various phenomena different from the photoreaction used in the conventional photosensitive material system for low to medium power density exposure can be used. Specifically, structural changes such as phase changes, morphological changes, etc. can be used in addition to chemical changes. Usually, such a recording method using high power density exposure is called heat mode recording, and the light energy absorbed by the light-sensitive material is converted into heat, and the generated heat causes
It is believed that the desired phenomenon is caused.

A great advantage of such a heat mode recording method is that fixing of an image after exposure is not essential. That is, the phenomenon used for image recording of the heat mode photosensitive material is as follows.
Fixation of the image after exposure is not essential, since exposure to light of normal intensity and under normal environmental temperatures do not occur substantially. Therefore, for example, using a photosensitive layer that is insolubilized or solubilized by heat mode exposure, and after an image exposure, an image obtained even if exposed to ambient light and then developed (removal of a non-image portion) for an arbitrary period of time, A system that does not change is possible. Therefore, according to the heat mode recording,
It is also possible to obtain a lithographic printing plate precursor that is desirable for the on-press development system described above.

[0008] As one of the preferable methods for producing a lithographic printing plate based on heat mode recording, a hydrophilic image forming layer is provided on a hydrophilic support, and the resulting image is heat mode exposed, and the solubility of the hydrophilic layer is reduced. A method has been proposed in which the dispersibility is changed and, if necessary, the unexposed portions are removed by wet development.
Further, the conventional heat mode type original plate has another serious problem that the non-image portion has poor stainability or the image portion has low strength. That is, it is necessary to improve the solubility change in the vicinity of the support in the image forming layer due to exposure, which is smaller than that in the vicinity of the surface of the image forming layer. In the heat mode type original plate, the amount of heat generated at the time of heat mode exposure is based on the light absorption of the light absorbing agent in the recording layer. Therefore, the amount of heat generated is large on the surface of the recording layer and small near the support. Therefore, the degree of change in solubility of the recording layer near the support becomes relatively small. As a result, in the heat mode negative master, the ink-receiving layer was sometimes removed during the development and / or printing steps in the exposed areas where the hydrophobic ink-receiving layer should be provided. Such removal of the image-area ink-receiving layer in the negative-type master causes a problem of poor printing durability in terms of printing performance. In particular, when a metal support having high thermal conductivity such as aluminum, which is preferable in terms of printability, is used, the above-described problem is remarkable because heat diffusion further hinders a temperature rise near the support. is there. In order to obtain a sufficient change in solubility near the substrate, an extremely large exposure energy was required, or post-treatment such as heating after exposure had to be performed.

For example, as described in Japanese Patent No. 2938397, an image is formed by thermally fusing thermoplastic hydrophobic polymer fine particles by infrared laser exposure.
There is a method in which a plate is mounted on a printing press cylinder, and the printing plate is developed with a dampening solution and / or ink. However, in such a method of simply forming an image by heat fusion, although good on-press developability is exhibited, when the heat-sensitive layer (image forming layer) is provided directly on the aluminum substrate, the generated heat is taken away by the aluminum substrate. Therefore, no reaction occurs on the interface between the substrate and the heat-sensitive layer, and the printing durability becomes insufficient. Similarly, Japanese Patent Application Laid-Open No. 9-127683 or WO 99/10
Japanese Patent Publication No. 186 also discloses that thermoplastic fine particles are heat-sealed and an image is formed by on-press development, but the printing durability similarly becomes insufficient.

In addition, Japanese Patent Application Laid-Open No. 52-113219 discloses a positive type comprising a compound which can be decomposed by light and heat (for example, a diazonium compound), material particles capable of absorbing light and converted into heat, and a binder. An image recording material is disclosed which decomposes a diazonium compound by heat to record an image.

Further, Japanese Patent Application Laid-Open No. Sho 62-164049,
JP-A-6-1088 discloses a photosensitive material in which a blocked isocyanate is combined with a light-to-heat conversion substance. However, these materials have insufficient sensitivity and printing durability because they use a low molecular weight blocked isocyanate. there were. Also,
U.S. Pat. No. 5,360,836 describes a monomer compound having a blocked isocyanate structure and a polymerizable double bond. However, with a negative recording material using a blocked isocyanate compound, recording can be performed by heat using a solid-state laser or semiconductor laser (thermal mode) having an emission region from infrared to near infrared, and such recording is possible. When no test was performed, none of the samples had good sensitivity and storage stability. Further, there was no alkaline water-based developer similar to a conventional lithographic printing plate having good developability.

[0012]

SUMMARY OF THE INVENTION As described above, after image recording, heat-development can be carried out simply without post-heating, or has good on-press developability, high sensitivity, and high printing durability. At present, no photographic light-sensitive material has been obtained yet.
Therefore, an object of the present invention is an image forming material that can be suitably used for a lithographic printing plate precursor for scanning exposure adapted to a heat mode recording method, that is, high sensitivity to the oscillation wavelength of a short wavelength semiconductor laser, It has excellent storage stability and can be developed with water or an aqueous solution, or has good on-press developability that allows it to be mounted on a printing machine and printed without development, and furthermore in terms of printing durability on the printing surface It is another object of the present invention to provide an image forming material which is further improved.

[0013]

Means for Solving the Problems The present inventors have made intensive studies in order to achieve the above-mentioned object, and as a result, have found that the above-mentioned disadvantages of the prior art can be overcome by employing the following configuration. That is, the present invention is as follows. (1) An image forming material comprising a polymer having at least one kind of repeating unit having a structure represented by the following general formulas (I) to (III).

[0014]

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(In the formulas (I) to (III), R¹Is a hydrogen atom,
R represents an alkyl group or a halogen atom; ^Two~ R^FourIs alkyl
Represents a group. L represents a divalent linking group; X is an oxygen atom;
And Y represents a hydrogen atom, a metal atom,
Represents an alkyl silyl group, and Ar represents an aromatic carbocyclic group.
You. (2) On the hydrophilic support, the above-mentioned general formulas (I) to (III)
Having at least one repeating unit represented by the formula:
Having a body and an image forming layer containing a photothermal conversion material
A lithographic printing plate precursor characterized by the following: (3) On a hydrophilic support, the above-mentioned general formulas (I) to (III)
Having at least one repeating unit represented by the formula:
Form containing fine particles containing body and photothermal conversion material
A lithographic printing plate precursor comprising a layer.

A lithographic printing plate precursor using the image-forming material of the present invention can produce a high printing durability negative-working lithographic printing plate without post-heating. In the case of a mere printing plate without heat fusion of thermoplastic fine particles, the film strength was insufficient and the printing durability was insufficient.However, by using the lithographic printing plate precursor of the present invention, high printing durability was obtained. Can be produced. As described above, the image forming material of the present invention has the general formula (I)
A precursor polymer containing a polymer having at least one type of repeating unit having a structure represented by formulas (III) to (3), which causes a chemical reaction by heating to easily produce an isocyanate having high reaction activity. contains. The lithographic printing plate precursor using this image forming material is heated by heat generated by irradiation with laser exposure, and the generated isocyanate is converted into a compound having a nucleophilic group in the image forming layer or by self-hydrolysis with water. It reacts with the generated amine to form a strong film and is water resistant. Since the unexposed portions are dispersed in the hydrophilic polymer in a state where each compound is dispersed in a particle or / and solid state, the unexposed portions can be easily removed by an aqueous developer, and a heat-sensitive image can be easily formed. is there. Therefore, simple development processing such as water development and dry development, or development processing is not required. Plates can be directly mounted on a printing press for plate making and printing, and hydrophobic / hydrophilic discrimination (identification ) Can be provided, and a lithographic printing plate precursor from which a clear printed matter can be obtained with good ink depositability and printing durability can be provided. Also,
The image forming material of the present invention is a high molecular weight polymer having a reactive isocyanate group as a precursor, and can provide a lithographic printing plate precursor having improved storage stability.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an image forming material and a lithographic printing plate precursor according to the present invention will be described in detail. The image forming material of the present invention contains a polymer having at least any one of the repeating units represented by the following general formulas (I) to (III). Hereinafter, the repeating units represented by the general formulas (I) to (III), which are characteristic components of the image forming material of the present invention, will be specifically described.

[0018]

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In the formulas (I) to (III), R ₁ is a hydrogen atom,
An alkyl group having 1 to 6 carbon atoms, a halogen atom (a chlorine atom,
(Bromine atom). R ₂ represents an alkyl group having 1 to 12 carbon atoms, which may be the same or different. The alkyl group may have a cyclic structure or a branch. L is a single bond or a divalent linking group selected from a divalent aliphatic group, a divalent aromatic group, a divalent heterocyclic group and a combination thereof, , The aromatic group and the heterocyclic group may have a substituent. Also, -O
-, - S -, - CO -, - NH -, - SO 2 -, - SO
A divalent linking group may be formed by a combination with a linking group selected from-. The number of carbon atoms of the aliphatic group is preferably from 1 to 60, more preferably from 1 to 30, still more preferably from 1 to 20,
Most preferably, it is 1 to 10. The aliphatic group may be unsaturated (having a double bond or a triple bond). The aliphatic group may have a cyclic structure or a branch. The aromatic group preferably comprises a benzene ring or a naphthalene ring, more preferably a benzene ring. The heterocyclic group preferably has a 3- to 10-membered heterocyclic ring, more preferably has a 4- to 8-membered heterocyclic ring, and most preferably has a 5- or 6-membered heterocyclic ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. An aliphatic ring, an aromatic ring, or another hetero ring may be condensed or spiro-bonded to the hetero ring. Examples of the heterocycle include a pyrrolidine ring, a piperidine ring, a piperazine ring, a morpholine ring, a tetrahydrofuran ring, a tetrahydropyran ring, a tetrahydrothiophene ring, a dioxane ring, an oxazole ring, a thiazole ring, a pyridine ring, a pyrazine ring, a triazine ring, and a furan ring. , A thiophene ring and an isocyanuric ring. Examples of the substituent of the aliphatic group, the aromatic group and the heterocyclic group include a hydroxyl, a halogen atom (eg, a chlorine atom), a cyano, an amino, a substituted amino group, a heterocyclic group, an acyl group and an acyloxy group. . The substituent of the substituted amino group is preferably an alkyl group or an aryl group. The aromatic group and the heterocyclic group may have an alkyl group as a substituent.

X represents a leaving group bonded to a nitrogen atom by an oxygen atom. For example, —OR (R: an alkyl group or an aryl group having 1 to 12 carbon atoms), —O—CO—R ₅ (R ₅ : 1 to 12 carbon atoms)
12 alkyl groups and aryl groups), —O—SO ₂ —R
₅ (R: an alkyl group or an aryl group having 1 to 12 carbon atoms). Y represents a hydrogen atom, a monovalent or divalent metal atom (for example, a sodium atom, a potassium atom, a silver atom), or a trialkylsilyl group of an alkyl group having 1 to 12 carbon atoms, and Ar represents an aromatic group. Represents a benzene ring or a naphthalene ring, and more preferably a benzene ring. The heterocyclic group has 3 to 1 members
It preferably has a 0-membered heterocycle, more preferably has a 4- to 8-membered heterocycle, and most preferably has a 5- or 6-membered heterocycle. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. Ar may have a substituent.

A homopolymer composed of only a single repeating unit represented by the formulas (I) to (III) can be used in the image forming layer of the present invention, but a copolymer composed of two or more repeating units may be used. Can be used. Further, a copolymer comprising a single repeating unit represented by formulas (I) to (III) and another repeating unit can be used. Other repeating units include ethylenically unsaturated monomers (eg, acrylic acid, methacrylic acid, acrylates, methacrylates, acrylamide, methacrylamide, vinyl esters, sterene, styrene derivatives, acrylonitrile, maleic anhydride, Repeat units derived from maleimide) are preferred. Copolymers consisting of a single repeating unit represented by formulas (I) to (III) and other repeating units include compounds represented by formulas (I) to (I)
The single repeating unit represented by (III) is preferably contained in an amount of 5 to 99 mol%, more preferably 10 to 90 mol%. The weight average molecular weight of the polymer having a single repeating unit represented by formulas (I) to (III) used in the present invention is preferably from 3,000 to 200,000, more preferably from 5,000 to 100,000.

The compounds having structures represented by the general formulas (I) to (III) of the present invention can be obtained by polymerizing a monomer synthesized with reference to the following documents by a known method, or by a known method. Can be synthesized by conducting a polymer reaction with reference to the following literature. References for compounds of general formula (I): 1) Guerrke, Justu
s Liebigs Ann. Chem., 205 , 291, 1880; 2) Jones, JA
. mer.Chem.Soc, 44, 417,1922; 3 ) Jones, J.Amer.Chem.
Soc., 46 , 2526, 1922; 4) Stafford, J. Org. Chem., 63 , 10.
040,1998. References for compounds of general formula (II): Furukawa, Bull.
m. Soc. Jpn., 51 , 3599, 1978. References for compounds of general formula (III): Rigaudy, Tetrahed
ron Lett, 21 , 3367, 1980. Specific examples of preferred repeating units having the structures represented by formulas (I) to (III) are shown below, but the present invention is not limited thereto.

[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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(Image Forming Layer) The image forming layer (thermosensitive layer) which is a characteristic part of the lithographic printing plate precursor according to the invention will be described. As described above, the lithographic printing plate precursor using the image forming material of the present invention comprises, on a hydrophilic support, at least one of the repeating units having the structure represented by the general formulas (I) to (III). It has an image forming layer formed by applying a coating liquid containing a fine particle or solid dispersion of a polymer having one kind of repeating unit and a composition containing a photothermal conversion substance. Further, a stronger crosslinked film can be formed by adding a compound having a nucleophilic group to the image forming layer. . Examples of the nucleophilic group include a hydroxyl group, an amino group, a mercapto group, a carboxyl group, an active methylene group, a heterocyclic group, an active methylene group, and the like. The compound may be a monomer or a polymer, but is preferably a polymer. These compounds may form the image forming layer in a state of being dissolved with the compound of the present invention, in a state of fine particles containing either one, or in a state of both particles. Preferred examples of the repeating unit in the case of a polymer having a nucleophilic group are shown below, but the present invention is not limited thereto.

[0031]

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[0032]

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The image forming material of the present invention is formed by dissolving a polymer having at least one of the repeating units represented by the above general formulas (I) to (III) on a support to form a polymer film. Layer or an image forming layer contained in the form of fine particles or / and solid dispersion.

When the above-mentioned image forming material has an image forming layer of a polymer film, the film thickness is from 0.2 μm to 5 μm.
μm is preferred, and more preferably in the range of 0.5 μm to 2 μm. When the above-mentioned image forming material is in the form of fine particles or / and solid dispersion, the particle size is 0.01.
μm to 50 μm, more preferably 0.05 μm
-10 μm range, and most preferably 0.05 μm
The range is 2 μm. The larger the polymer particles, the lower the resolving power of the image forming material. On the other hand, if the size is too small, the hydrophilic and hydrophobic discrimination tends to decrease, and the image forming property tends to deteriorate. When the image forming material of the present invention contained in the image forming layer is in the form of fine particles or / and solid dispersion, the compounding amount is 10 to 9
A range of 9% by weight is preferable, and a range of 25 to 90% by weight is more preferable.

As the method of dispersing in the form of particles or solid, a solid dispersion method in which the above-mentioned image forming material of the present invention is added to a non-solvent and pulverized, or a method in which the image forming material of the present invention is dissolved in a solvent which is soluble, is used. An emulsification dispersion or emulsification dispersion solvent that is emulsified and dispersed in another non-solvent that is incompatible with the solvent and does not dissolve these compounds using a homomixer or the like, and volatilizes and removes the solvent component as necessary to form solid particles. Evaporation method etc. are raised. When these methods are used, a surfactant or a polymer component capable of stabilizing dispersion may be added to stabilize the particle state. When the emulsification dispersion method is used, the particles may be prepared by mixing with another organic polymer component as a particle component in addition to the image forming material of the present invention. Further, these particles may have a core-shell structure covered with another polymer as a core component,
The shell component may be three-dimensionally crosslinked. When the polymer of the image forming material is a high molecular weight polymer, the polymer may be formed into particles using a known method for producing polymer fine particles such as a dispersion polymerization method or an emulsion polymerization method.

When the light-to-heat conversion material is added to the image forming layer, the same layer as the image forming material of the present invention, a separate layer,
It may be added either inside or outside the particles. Further, the image forming layer of the lithographic printing plate precursor using the photosensitive material of the present invention may further contain a thermoplastic polymer. By adding this thermoplastic polymer, melting and fusion of the polymer occur by heat, and an improvement in the hydrophobic effect is expected. It is preferable that the thermoplastic polymer is in the form of fine particles because the melting and fusing effects can be easily achieved. In order to easily exhibit the melting and fusing effects, it is preferable to use a polymer having a glass transition temperature of 150 ° C. or lower, more preferably 120 ° C. or lower. When the glass transition temperature is 150 ° C. or higher, thermal fusion of the polymer hardly occurs, and it is difficult to form a strong image with a laser having a relatively small output. The lower limit of the glass transition temperature is not particularly limited, but is preferably about 10 ° C. or higher. If the glass transition temperature is too low, the coating liquid containing the fine particles of this polymer is applied to the substrate and dried to form a recording layer. May occur, and it may not be possible to form an image forming layer in which particles are well dispersed.

Specific examples of thermoplastic polymers suitable for use in the present invention include, for example, polyethylene, polyvinyl chloride, poly (meth) acrylate, poly (meth) acrylate, polybutyl methacrylate, and the like. Polyhydroxyethyl methacrylate, polyglycidyl methacrylate, polystyrene, styrene butadiene copolymer, styrene-maleic anhydride copolymer, poly-p
-Hydroxystyrene, poly-m-hydroxystyrene, phenolic resin, cresol resin, epoxy resin,
Examples include polyurethane, polyester, polycarbonate, polyvinylidene chloride, polyacrylonitrile, polyvinyl carbazole, and the like, or a copolymer thereof. The molecular weight of the thermoplastic polymer is between 5,000 and 1,000.
It can be selected from the range of 10,000. When the thermoplastic polymer is in the form of fine particles, the particle size is preferably 0.01 μm to 50 μm, more preferably 0.0 μm to 50 μm.
In the range of 5 μm to 10 μm, and most preferably 0.05.
The range is from μm to 2 μm. As the size of the polymer particles increases, the resolution of the thermal recording material decreases. On the other hand, when the size is too small, hydrophilic and hydrophobic discrimination tends to decrease and image forming properties tend to deteriorate. Such polymer particles are preferably present as a dispersion in an aqueous coating liquid from the viewpoint of stability, and an aqueous dispersion of such polymer particles is disclosed in US Pat.
It can be produced by the method disclosed in US Pat.

Other methods particularly suitable for preparing aqueous dispersions of thermoplastic polymers include (1) dissolving a hydrophobic thermoplastic polymer in a water-immiscible organic solvent;
(2) Dispersing the solution thus obtained in water or an aqueous medium, and (3) removing the organic solvent by evaporation. The blending amount of the hydrophobic thermoplastic polymer fine particles contained in the image forming layer,
Preferably it is in the range of 1-90% by weight, more preferably 10-8.
The range is 0% by weight. If the amount is too small,
From the viewpoint of improving the hydrophobicity in the exposed portion, the effect of adding this polymer is insufficient.On the other hand, if the blending amount of the hydrophobic thermoplastic polymer fine particles is too large, the hydrophilic layer which is the non-exposed portion is not added. As a result, ink receptivity occurs in the non-image area, and the non-image area may be stained.

According to the image forming layer containing such thermoplastic polymer fine particles, a pattern region in which an image is to be formed is directly heated or a pattern region capable of converting light to heat is contained. Exposure while being in contact with the original causes hydrophobic thermoplastic polymer fine particles to soften or melt in the image-like heating or exposure area in the image forming layer, and to solidify in the exposure area after heating is completed. The hydrophobicity in the region is improved.

(Hydrophilic polymer) A hydrophilic resin may be added to the image forming layer of a lithographic printing plate precursor using the image forming material of the present invention. The addition of the hydrophilic resin not only improves the on-press developability but also improves the film strength of the image forming layer itself. Further, the resin can be cross-linked and cured to provide a lithographic printing plate precursor that does not require development processing. In addition, by using a polymer having active hydrogen for the hydrophilic resin, it reacts with the isocyanate group released from the image forming material of the present invention, so that a stronger film can be formed. Furthermore, by arranging an acidic group capable of acid-base interaction with a polyfunctional base released from the base generator on the hydrophilic resin, cross-linking occurs due to the acid-base interaction, and a stronger film can be formed. As the hydrophilic resin, for example, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl and carboxymethyl, and hydrophilic sol-gel conversion binder resins are preferable.

Specific examples of the hydrophilic resin include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and their Na salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, and styrene-maleic acid copolymers. , Polyacrylic acids and their salts, polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers of hydroxypropyl acrylate And copolymers, hydroxybutyl methacrylate homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers , Polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols and homopolymers of hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide having a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight; Copolymers, homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide and the like can be mentioned.

The hydrophilic resin may be cross-linked to be used. Examples of the water-resistant agent to be cured include aldehydes such as glyoxal, melamine formaldehyde resin and urea formaldehyde resin, N-methylol urea and N-methylol melamine. Methylol compounds such as methylolated polyamide resins, active vinyl compounds such as divinyl sulfone and bis (β-hydroxyethyl sulfonic acid), epichlorohydrin and polyethylene glycol diglycidyl ether, polyamide / polyamine / epichlorohydrin adducts, polyamide epichlorohydride Epoxy compounds such as phosphorus resin, ester compounds such as monochloroacetic acid ester and thioglycolic acid ester, and polycarboxylic acids such as polyacrylic acid and methyl vinyl ether / maleic acid copolymer; Acid, titanyl sulfates, Cu,
Examples include inorganic crosslinking agents such as Al, Sn, V, and Cr salts, and modified polyamide polyimide resins. In addition, a crosslinking catalyst such as ammonium chloride, a silane coupling agent, and a titanate coupling agent can be used in combination.

The amount of the hydrophilic resin added to the image forming layer is preferably 5 to 70%, more preferably 5 to 40% of the solid content of the image forming layer.
Is more preferred. Within this range, good on-press developability and film strength are obtained, which is preferable.

(Light-to-Heat Conversion Material)
To improve sensitivity, it contains a photothermal conversion material that absorbs infrared rays and generates heat. As such a photothermal conversion material, 7
Any light-absorbing substance having an absorption band in at least a part of 00 to 1200 nm may be used, and various pigments, dyes and metal fine particles can be used.

Examples of pigments include commercially available pigment and color index (CI) handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977), and “Latest Pigment Application Technology” (CMC Publishing, 1986). And "printing ink technology" (CMC Publishing, 1984) can be used.

These pigments can be used after being subjected to a known surface treatment, if necessary, in order to improve the dispersibility in the layer to which the pigment is added. Surface treatment methods include a method of surface-coating a hydrophilic resin or a lipophilic resin, a method of attaching a surfactant, and a reactive substance (for example, silica sol, alumina sol, a silane coupling agent or an epoxy compound,
A method of bonding an isocyanate compound) to the surface of the pigment. Pigment to be added to the hydrophilic layer is easy to disperse with the water-soluble resin, and so as not to impair the hydrophilicity,
It is desirable that the surface is coated with a hydrophilic resin or silica sol. The particle size of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Particularly preferred pigments include carbon black.

Examples of the dye include commercially available dyes and literatures (eg, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, 1975, “Kagaku Kogyo”, May 1986, “Near-Infrared Absorbing Dyes” , "Development and Market Trend of Functional Dyes in the 90's", Chapter 2, Section 2.3 (1990), CM) or patents can be used.
Specifically, azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes,
Infrared absorbing dyes such as carbonium dyes, quinone imine dyes, polymethine dyes and cyanine dyes are preferred.

Further, for example, see JP-A-58-12524.
No. 6, JP-A-59-84356, JP-A-60-787
No. 87, etc .;
173696, JP-A-58-181690, methine dyes described in JP-A-58-194595, and the like;
JP-A-58-112793, JP-A-58-22479
No. 3, JP-A-59-48187, JP-A-59-739
No. 96, JP-A-60-52940, JP-A-60-63
744, etc .; squarylium dyes described in JP-A-58-112792; cyanine dyes described in British Patent 434,875; and dyes described in U.S. Pat. No. 4,756,993. And cyanine dyes described in U.S. Pat. No. 4,973,572, dyes described in JP-A-10-268512, JP-A-11-23.
No. 5,883, phthalocyanine compounds.

As a dye, US Pat. No. 5,156,
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645, JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, JP-A-59-84248, and JP-A-59-84248.
No. 84249, No. 59-146063, No. 59-14
No. 6061, pyranium compounds described in JP-A-59-216146, cyanine dyes described in US Pat. No. 4,283,475, pentamethine thiopyrylium salts described in U.S. Pat. 5-70
No. 2, a pyrylium compound, Eporin III-178, Epolite III-130, manufactured by Eporin Co., Ltd.
Epolite III-125 and the like are also preferably used. Among these, a preferred dye to be added to a hydrophilic matrix such as a hydrophilic resin of the heat-sensitive layer is a water-soluble dye, and specific examples are shown below. However, the present invention is not limited to these.

[0050]

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[0051]

Embedded image Further, the light-to-heat conversion substance is preferable by incorporating a light-to-heat conversion agent in the hydrophobic polymer fine particles, whereby fusion between the particles is further promoted. The light-to-heat conversion substance may be used, but a lipophilic dye is more preferable. Specific examples include the following dyes.

[0052]

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[0053]

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[0054]

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The above-mentioned organic photothermal conversion agent can be added to the image forming layer up to 30% by weight. It is preferably 5 to 25% by weight, particularly preferably 7 to 20% by weight.
It is. Within this range, good sensitivity is obtained.

In the image forming layer and the like of the present invention, metal fine particles can be used as a photothermal conversion agent. Many of the metal fine particles are light-heat converting and also self-heating.
Preferred metal fine particles include Si, Al, Ti, V, and C.
r, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr,
Mo, Ag, Au, Pt, Pd, Rh, In, Sn,
A simple substance or an alloy of W, Te, Pb, Ge, Re, and Sb, or fine particles of oxides and sulfides thereof are exemplified.
Among the metals constituting these metal fine particles, preferred metals have a melting point of about 100, which is easily fused by light irradiation.
Metals having an absorption in the infrared, visible or ultraviolet region below 0 ° C., such as Re, Sb, Te, Au, Ag, Cu, G
e, Pb and Sn. Particularly preferred are metal fine particles having a relatively low melting point and a relatively high absorbance to heat rays, for example, Ag, Au, Cu, Sb, Ge.
And Pb, particularly preferred elements are Ag, Au and Cu.

Further, for example, Re, Sb, Te, Au, A
g, Cu, Ge, Pb, Sn or other low-melting metal particles and self-heating metal particles such as Ti, Cr, Fe, Co, Ni, W, Ge, etc. It may be composed of a substance. Ag, Pt, Pd
It is preferable to use a combination of a metal-type micro-piece and a metal-type micro-piece having particularly large light absorption when made into the same micro-piece.

The effects of the present invention can be further exerted by subjecting the surfaces of the above-mentioned fine particles of a simple metal and an alloy to hydrophilic treatment. Means of surface hydrophilicity is a compound that is hydrophilic and has an adsorptivity to particles, such as a surface treatment with a surfactant, or a surface treatment with a substance having a hydrophilic group that reacts with the constituent substances of the particles, A method such as providing a protective colloid hydrophilic polymer film can be used. Particularly preferred is a surface silicate treatment. For example, in the case of fine iron particles, the surface can be made sufficiently hydrophilic by a method of immersing in an aqueous solution of sodium silicate (3%) at 70 ° C. for 30 seconds. Other metal fine particles can be subjected to a surface silicate treatment in the same manner.

The size of these particles is preferably 10 μm.
m, more preferably 0.003 to 5 μm, particularly preferably 0.01 to 3 μm. Within this range, good sensitivity and resolving power can be obtained, which is preferable.

In the present invention, when these metal fine particles are used as a light-to-heat conversion agent, the amount added is preferably at least 10% by weight, more preferably at least 20% by weight, particularly preferably at least 20% by weight of the solid content of the image forming layer. Used at 30% by weight or more. High sensitivity is obtained within this range, which is preferable.

Further, in the image forming layer of the present invention, a dye having a large absorption in the visible light region is used as a coloring agent for the image so that the image area and the non-image area can be easily distinguished after the image is formed. Can be. Specifically, Oil Yellow # 1
01, oil yellow # 103, oil pink # 31
2. Oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Co., Ltd.), Victoria Pure Blue, crystal violet (CI42555), methyl Violet (CI42535), ethyl violet, rhodamine B (CI145170B), malachite green (CI
42000), methylene blue (CI52015) and the like.
And dyes described in JP-A-62-293247. Also, pigments such as phthalocyanine pigments, azo pigments, and titanium oxide can be suitably used. The addition amount is preferably from 0.01 to 10% by weight based on the total solid content of the coating solution for the image forming layer.

Further, a plasticizer can be added to the image forming layer of the present invention, if necessary, in order to impart flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.

The image-forming layer of the present invention is prepared by dissolving or dispersing the above-mentioned necessary components in a solvent to prepare a coating solution and coating. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol,
2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, Sulfolane, γ-
Examples thereof include, but are not limited to, butyl lactone, toluene, and water. These solvents are
Used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by weight.

The coating amount (solid content) of the image forming layer on the support obtained after coating and drying varies depending on the application.
Generally, 0.5 to 5.0 g / m ² is preferable. Various methods can be used as a method of applying. For example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, roll coating and the like can be mentioned.

The coating solution for the image forming layer according to the present invention includes:
Surfactants for improving coatability, for example,
Fluorosurfactants such as those described in 2-170950 can be added. The preferred amount is
It is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight of the total solids of the heat-sensitive layer.

The lithographic printing plate precursor according to the present invention is provided on the image forming layer in order to protect the hydrophilic image forming layer surface from contamination by lipophilic substances during storage and contamination (fingerprints) due to finger contact during handling. May be provided with a hydrophilic overcoat layer.

The hydrophilic overcoat layer used in the present invention can be easily removed on a printing press, and is selected from a water-soluble resin or a water-swellable resin obtained by partially crosslinking a water-soluble resin. It contains.

The water-soluble resin is selected from a water-soluble natural polymer and a synthetic polymer, and can be used to form a film when coated and dried using the water-soluble resin alone or together with a crosslinking agent. Specific examples of the water-soluble resin preferably used in the present invention include, as natural polymers, gum arabic, water-soluble soybean polysaccharide, and cellulose derivatives (eg, carboxymethyl cellulose, carboxyethyl cellulose,
Methylcellulose), its denatured forms, white dextrin, pullulan, enzymatically degraded etherified dextrin, etc.
For synthetic polymers, polyvinyl alcohol (having a hydrolysis rate of polyvinyl acetate of 65% or more), polyacrylic acid,
Its alkali metal salt or amine salt, polyacrylic acid copolymer, its alkali metal salt or amine salt, polymethacrylic acid, its alkali metal salt or amine salt,
Vinyl alcohol / acrylic acid copolymer and its alkali metal salt or amine salt, polyacrylamide, its copolymer, polyhydroxyethyl acrylate, polyvinylpyrrolidone, its copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer Polymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, alkali metal salt or amine salt thereof, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer, alkali metal salt thereof Alternatively, amine salts and the like can be mentioned. Further, according to the purpose, two or more of these resins can be used in combination. However, the invention is not limited to these examples.

In the case where at least one or more of the water-soluble resins are partially crosslinked to form an overcoat layer on the hydrophilic layer, the crosslinking is carried out by a crosslinking reaction using a reactive functional group of the water-soluble resin. . The cross-linking reaction may be covalent cross-linking or ionic cross-linking.

The crosslinking reduces the tackiness of the surface of the overcoat layer and improves the handleability of the lithographic printing plate. However, if the crosslinking proceeds too much, the overcoat layer changes to lipophilic, and the Moderate partial cross-linking is preferred because it makes removal of the layer difficult.

Examples of the compound (crosslinking agent) used in the crosslinking reaction include known polyfunctional compounds having crosslinking properties, such as polyepoxy compounds, polyamine compounds, polyisocyanate compounds, polyalkoxysilyl compounds, titanate compounds, and the like. Aldehyde compounds, polyvalent metal salt compounds,
Hydrazine and the like.

The crosslinking agents can be used alone or as a mixture of two or more. Among the crosslinking agents, a particularly preferred crosslinking agent is a water-soluble crosslinking agent, but a water-insoluble one can be used by dispersing it in water with a dispersant.

Particularly preferred combinations of a water-soluble resin and a crosslinking agent include carboxylic acid-containing water-soluble resin / polyvalent metal compound, carboxylic acid-containing water-soluble resin / water-soluble epoxy resin, and hydroxyl group-containing resin / dialdehydes. .

The preferable addition amount of the crosslinking agent is 2 to 2 of the water-soluble resin.
-10% by weight. Within this range, good water resistance can be obtained without impairing the removability of the overcoat layer on a printing press.

In addition, a nonionic surfactant can be mainly added to the overcoat layer in the case of aqueous solution application for the purpose of ensuring uniformity of application. Specific examples of such a nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride, polyoxyethylene nonyl phenyl ether, polyoxyethylene dodecyl ether, and the like. . The proportion of the nonionic surfactant in the total solid content of the overcoat layer is preferably 0.05 to 5% by weight, and more preferably 1 to 3% by weight.

When the water-soluble resin is not crosslinked, the thickness of the overcoat layer of the present invention is from 0.1 μm to 3.
0 μm is preferred, and a more preferred range is from 0.1 μm to 1.0 μm. When the water-soluble resin is partially crosslinked, the range is preferably 0.1 to 0.5 μm, and 0.1 to 0.3 μm.
μm is more preferred. Within this range, contamination of the hydrophilic layer by the lipophilic substance can be prevented without impairing the removability of the overcoat layer on the printing press.

In the lithographic printing plate precursor according to the present invention, the support on which the image forming layer can be applied is a dimensionally stable plate-like material such as paper, plastic (eg, polyethylene, polypropylene, polystyrene). Paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate) , Polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic film on which the above-mentioned metal is laminated or vapor-deposited. Preferred supports include a polyester film or an aluminum plate.

The aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of a different element. Further, a plastic is laminated on a thin film of aluminum or an aluminum alloy. The foreign elements contained in aluminum alloys include silicon, iron, manganese, copper, magnesium, chromium, zinc,
There are bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. However, as the aluminum plate applied to the present invention, an aluminum plate of a conventionally known material can be appropriately used.

The thickness of the substrate used in the present invention is 0.05 mm to 0.6 mm, preferably 0.1 mm to 0.6 mm.
0.4 mm, particularly preferably 0.15 mm to 0.3 mm
It is.

Prior to using the aluminum plate, it is preferable to perform a surface treatment such as surface roughening and anodic oxidation. The surface treatment makes it easy to improve hydrophilicity and ensure adhesion to the heat-sensitive layer.

The surface roughening treatment of the surface of the aluminum plate is performed by various methods. It is performed by a method of selective dissolution. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. As a chemical method, a method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in JP-A-54-31187 is suitable. Further, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Also, an electrolytic surface roughening method using a mixed acid as disclosed in JP-A-54-63902 can be used.

The surface roughening by the above-mentioned method is performed when the center line average roughness (Ra) of the surface of the aluminum plate is 0.2-1.
It is preferable that the coating be performed within a range of 0 μm. The roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide or sodium hydroxide as necessary, and further neutralized, and then, if necessary, anodized to enhance abrasion resistance. Processing is performed. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used, and generally, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. Anodizing treatment conditions vary depending on the electrolyte to be used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are appropriate. The amount of the formed oxide film is 1.0 to 5.0.
g / m ^2, it is particularly preferably 1.5 to 4.0 g / m ^2.

As the support used in the present invention, a substrate having the above-mentioned surface treatment and having an anodized film may be used as it is.
For further improvement of heat insulation, etc., if necessary,
A process for enlarging micropores of an anodized film, a process for sealing micropores, and a process for hydrophilizing a surface immersed in an aqueous solution containing a hydrophilic compound, which are described in JP-A-00-65219 and Japanese Patent Application No. 2000-14387, are appropriately performed. You can choose to do it. Suitable hydrophilic compounds for the above-mentioned hydrophilic treatment include polyvinylphosphonic acid, compounds having a sulfonic acid group, saccharide compounds, citric acid, alkali metal silicates, potassium zirconium fluoride, phosphates / inorganic fluorine compounds, and the like. Can be mentioned.

When a support having insufficient surface hydrophilicity such as a polyester film is used as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, described in Japanese Patent Application No. 2000-10810,
Applying a coating solution containing a colloid of an oxide or hydroxide of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. The hydrophilic layer formed is preferred. Among them, a hydrophilic layer formed by applying a coating solution containing a colloid of silicon oxide or hydroxide is preferable.

In the present invention, before the image forming layer is coated, if necessary, an inorganic undercoat layer such as a water-soluble metal salt such as zinc borate described in Japanese Patent Application No. 2000-143487 may be used. Or for example carboxymethylcellulose,
An organic undercoat layer containing dextrin, polyacrylic acid or the like can be provided. The undercoat layer may contain the photothermal conversion agent.

The lithographic printing plate precursor according to the present invention can form an image by high-power laser exposure, but a writer such as a thermal head may be used. In particular, in the present invention, it is preferable to use a laser that emits light in the infrared or near-infrared region. In particular, a laser diode that emits light in the near infrared region is particularly preferable. Further, recording by an ultraviolet lamp is also possible, but in the present invention, the wavelength is 760 nm.
It is preferable to perform image exposure using a solid-state laser and a semiconductor laser that emit infrared rays of from 1200 to 1200 nm. The output of the laser is preferably 100 mW or more, and it is preferable to use a multi-beam laser device in order to shorten the exposure time. Further, the exposure time per pixel is preferably within 20 μsec. The energy applied to the recording material is preferably from 10 to 300 mJ / cm ² .

The plate exposed in this manner is mounted on a cylinder of a printing machine without any simple development processing such as water development or dry processing, or without any processing. The plate attached without performing the developing process can be printed by the following procedure. (1) A method in which dampening water is supplied to the printing plate and development is performed on the machine, and then ink is further supplied to start printing. (2) A dampening solution and ink are supplied to the printing plate and developed on the machine. And (3) supplying ink to the plate, supplying dampening water and simultaneously supplying paper to start printing, and the like.

[0088]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, of course, are not intended to limit the scope of the present invention.

(Preparation of Aluminum Substrate) 99.5% or more of aluminum, 0.30% of Fe, and 0.10% of Si
%, 0.02% Ti, 0.013% Cu
The melt of the A1050 alloy was subjected to a cleaning treatment and cast.
In the cleaning treatment, a degassing treatment was performed to remove unnecessary gas such as hydrogen in the molten metal, and a ceramic tube filter treatment was performed. The casting was performed by DC casting. The solidified 500 mm thick ingot is ground 10 mm from the surface,
Homogenization treatment was performed at 550 ° C. for 10 hours so that the intermetallic compound was not coarsened. Next, after hot rolling at 400 ° C. and intermediate annealing in a continuous annealing furnace at 500 ° C. for 60 seconds, cold rolling was performed to obtain a rolled aluminum sheet having a sheet pressure of 0.30 mm. By controlling the roughness of the rolling roll, the center line average surface roughness Ra after cold rolling is set to 0.2 μm.
Was controlled. Then, it was subjected to a tension leveler to improve the flatness.

Next, a surface treatment for preparing a lithographic printing plate support was performed. First, in order to remove the rolling oil on the surface of the aluminum plate, a degreasing treatment was performed with a 10% aqueous sodium aluminate solution at 50 ° C. for 30 seconds, and a 30% sulfuric acid aqueous solution was neutralized at 50 ° C. for 30 seconds, and a smut removal treatment was performed.

Next, in order to improve the adhesion between the support and the image forming layer and to impart water retention to the non-image area, a so-called graining treatment was performed to roughen the surface of the support. 1
Aqueous solution containing 4% nitric acid and 0.5% aluminum nitrate
While maintaining the temperature at 5 ° C. and flowing the aluminum web into the aqueous solution, the anode-side electric quantity 240 C / d with an alternating waveform having a current density of 20 A / dm ² and a duty ratio of 1: 1 by the indirect power supply cell.
Electrolytic graining was performed by giving m ² . Then 10
Etching was performed with a 50% aqueous sodium aluminate solution at 50 ° C. for 30 seconds, and neutralization was performed with a 30% aqueous solution of sulfuric acid at 50 ° C. for 30 seconds, followed by smut removal processing.

In order to further improve abrasion resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. An anodic oxide film of 2.5 g / m ^{2 is} obtained by performing an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power supply cell while carrying an aluminum web through the electrolyte using a 20% aqueous solution of sulfuric acid at 35 ° C. as an electrolyte. It was created. Thereafter, a silicate treatment was performed to ensure hydrophilicity as a non-image portion of the printing plate. For the treatment, a 1.5% aqueous solution of sodium silicate No. 3 was maintained at 70 ° C., passed through the aluminum web so that the contact time was 15 seconds, and further washed with water. The amount of Si attached is 10mg
/ M ² . The center line surface roughness Ra of the support produced as described above was 0.25 μm.

Examples 1 to 5, Comparative Example 1 A composition having the following weight ratio was dispersed with glass beads for 10 minutes to prepare a carbon black dispersion.

(Carbon Black Dispersion) Carbon Black (particle size: 0.2 to 0.3 μm) 1.0 part by weight 1.6 parts by weight of a copolymer of benzyl methacrylate and methacrylic acid (molar ratio 72:29, weight average) Methyl ethyl ketone 1.6 parts by weight 1-methoxy-2-propanol 3.8 parts by weight

(Preparation of a negative type lithographic printing plate precursor) A negative type lithographic printing plate was prepared by applying a photosensitive solution having the following composition to the aluminum substrate obtained above and drying at 70 ° C. for 5 minutes to form an image forming layer. A printing plate precursor was obtained. The weight after drying of the image forming layer was 2.0 g / m ² .

(Coating Solution for Image Forming Layer) 2.4 g of the carbon black dispersion described above, polymer compound (compound described in Table 1, 20 wt% solution) 2.2 g Megafac F-176 (Dainippon Ink Chemical Industry Co., Ltd.) 0.06 g methyl ethyl ketone 15 g 2-methoxy-1-propanol 12 g

The obtained negative type lithographic printing plate precursor was treated with a Creo Tren equipped with a water-cooled 40 W infrared semiconductor laser.
With dsetter3244VFS, output 9W, outer drum rotation speed 21
0 rpm, plate energy 400 mJ / m ² , resolution 240
After exposure under the condition of 0 dpi, a developing solution manufactured by Fuji Photo Film Co., Ltd., DP-4 (1: 8), and a rinsing solution FR-3 (1:
When processed through an automatic processor equipped with 7), a negative image was obtained. The developing solution in this case is alkaline water (about pH 13). This lithographic printing plate is Heidel SO
Table 1 shows the results of printing with an R-KZ machine.

[0098]

[Table 1]

Examples 1 to 4 using the polymer compound of the present invention
In No. 5, good printed matter was obtained,
In Comparative Example 1, the entire photosensitive film was dissolved in the developer and no image was obtained.

Examples 6 to 10 and Comparative Example 2 (Synthesis Example of Fine Particle Dispersion) As an oil phase component, 6 g of the polymer shown in Table 2 below and an infrared absorber (IR below)
-24) 1.5 g and 0.1 g of anionic surfactant Pionin A-41C (manufactured by Takemoto Yushi) were dissolved in 7.4 g of methyl ethyl ketone and 13.7 g of ethyl acetate, and then polyvinyl alcohol (Kuraray Co., Ltd.) as an aqueous phase component was dissolved. ) PVA 205) was mixed with 53 g of a 1.8% aqueous solution and emulsified and dispersed with a homogenizer at 15000 rpm for 10 minutes.
Thereafter, while stirring at 40 ° C. for 3 hours, methyl ethyl ketone and ethyl acetate were evaporated. The solid content concentration of the obtained fine particle dispersion was 15.4% by weight. The average particle size was 0.30 μm.

[0101]

[Table 2]

[0102]

Embedded image

[0103]

Embedded image

An image forming layer coating solution containing the fine particles of the above synthesis example and having the following composition was prepared on the support obtained in the preparation of the above aluminum substrate, and then coated with a bar, followed by heating in an oven at 60 ° C. for 120 seconds. To prepare a lithographic printing plate precursor having a dry coating amount of the image forming layer of 1 g / m ² .

[Image forming coating solution] Water 25 g Fine particle dispersion (using the polymer described in Table 2) 20 g

The lithographic printing plate precursor thus obtained was combined with a water-cooled 40 W infrared semiconductor laser mounted Cr
At eo Co. Trendsetter3244VFS, output 9W, a rotational number of an external drum of 210 rpm, plate surface energy 300 mJ / m ^2, after exposure under the conditions of resolution of 2400 dpi, without development processing, it mounted produced by Heidelberg printing press SOR-M of the cylinder After supplying fountain solution, ink was supplied, and paper was further supplied to perform printing. As a result, all the lithographic printing plate precursors could be developed on-press without any problem, and printing was possible. Table 2 shows the number of printable sheets of each lithographic printing plate precursor.

[0107]

As described above, the image-forming material of the present invention contains a polymer having at least one type of repeating unit having a structure represented by the above general formulas (I) to (III), Has a blocked isocyanate structure that causes a chemical reaction to easily generate an isocyanate having a high reaction activity. The lithographic printing plate precursor using this image forming material is heated by the heat generated by the irradiation of the laser exposure, and the generated isocyanate is converted into a compound having a nucleophilic group in the image forming layer or by self-hydrolysis with water. It reacts with the generated amine to form a strong film and is water resistant. Since the unexposed portions are dispersed in the hydrophilic polymer in a state where each compound is dispersed in the form of particles or / and solid, they can be easily removed by an aqueous developer, and a heat-sensitive image can be easily formed. is there. Therefore, simple development processing such as water development and dry development, or development processing is not required. Plates can be directly mounted on a printing press for plate making and printing, and hydrophobic / hydrophilic discrimination (identification ) Can be provided, and a lithographic printing plate precursor from which a clear printed matter can be obtained with good ink depositability and printing durability can be provided. The image forming material of the present invention is a high molecular weight polymer having a reactive isocyanate group as a precursor, and can provide a lithographic printing plate precursor having improved storage stability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/004 521 G03F 7/004 521 7/033 7/033 F term (Reference) 2H025 AB03 AC08 AD01 BJ03 CB14 CB41 CB54 CC11 2H096 AA06 BA06 EA04 EA23 2H114 AA04 AA14 AA22 AA24 BA01 BA10 DA47 DA52 DA75 EA01 EA02 FA16 4J100 AB00P AB07P AH35P AM21P BA04P BA06P BA15P BA34P BA41P BA50P BA58P BA72P 76

Claims (3)

[Claims] 1. A compound represented by the following general formulas (I) to (III):
Having at least one type of repeating unit
An image-forming material comprising a polymer. Embedded image(In formulas (I) to (III), R₁Is a hydrogen atom, an alkyl group,
Represents a halogen atom, R _Two~ R_FourRepresents an alkyl group. L
Represents a divalent linking group, and X represents a devalent bond bonded to N through an oxygen atom.
Y represents a hydrogen atom, a metal atom, a trialkyl
Ar represents an aromatic carbocyclic group; ) 2. The method according to claim 1, wherein on the hydrophilic support, the compound represented by the general formula (I)
A lithographic printing plate precursor comprising: a polymer having at least one repeating unit represented by (III); and an image forming layer containing a photothermal conversion material. 3. The method according to claim 1, wherein the compound represented by the general formula (I)
A lithographic printing plate precursor comprising: fine particles containing a polymer having at least one of the repeating units represented by (III); and an image forming layer containing a photothermal conversion material.