JP2002154280A - Original plate for lithographic printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat mode-type original plate for lithographic printing with such advantages that an original plate can be easily made up without the necessity to perform a development process and also can be made up by directly mounting the original plate on a printing machine and is almost free from print scumming on a printed surface and shows excellent resistance to plate wear with the high coating film strength of an image recording layer. SOLUTION: This original plate for lithographic printing has a hydrophilic image recording layer which is composed of a hydrophilic integrated resin containing a hydrophobic precursor with a hydrophilic graft chain on the surface and becomes thermally hydrophobic, formed on a support. Especially the original plate has a photothermal conversion agent contained in at least either of the image recording layer, an adjacent layer or the support.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate which does not require development and has excellent printing durability. More specifically, a lithographic plate that can be made by heat-mode image recording, and that can also be image-recorded by scanning exposure based on digital signals, and that can be mounted on a printing press without development to make and print. It relates to an original plate for printing.

[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. As such a lithographic printing plate precursor, a PS plate in which a lipophilic photosensitive resin layer is provided on a hydrophilic support has been widely used.

On the other hand, with the widespread use of digitization techniques for electronically processing, storing, and outputting image information using a computer, various new image output methods corresponding to such digitization techniques have become practical. It is becoming. One of them is a computer that carries digitized image information in highly convergent radiation such as laser light, scans and exposes the original plate with this light, and directly manufactures a printing plate without passing through a lithographic film.・ To-plate technology is attracting attention. Therefore, obtaining an original plate for a printing plate adapted to this purpose is an important technical problem.

Recently, high-power solid-state lasers such as semiconductor lasers and YAG lasers have become available at low cost, and these lasers, which are easy to incorporate into digitization technology, are used as image recording means by scanning exposure. Plate making methods for manufacturing printing plates have become promising. In the conventional plate-making method, image recording is performed by giving an imagewise exposure of the photosensitive original plate at low to medium illuminance and changing the image-like physical properties of the original plate surface by a photochemical reaction. In the method using density exposure, a large amount of light energy is intensively irradiated onto an exposure area during an instantaneous exposure time, the light energy is efficiently converted to heat energy, and the heat causes chemical change, phase change, A thermal change such as a change in form or structure is caused, and the change is used for image recording. That is, image information is input by light energy such as laser light, while image recording is recorded by a reaction by heat energy. Normally, a recording method using heat generated by such high power density exposure is called heat mode recording, and changing light energy to heat energy is called photothermal conversion.

A major advantage of the plate making method using the heat mode recording means is that the plate is not exposed to light having a normal illuminance level such as indoor illumination, and that an image recorded by high illuminance exposure does not require fixing. . That is, if a heat mode photosensitive material is used for image recording, it is safe against room light before exposure, and it is not essential to fix an image after exposure. Therefore, if heat mode recording is used, it is expected that it will be possible to obtain a lithographic printing plate precursor that can be easily developed in a computer-to-plate system.

[0006] As one of the preferable methods for producing a lithographic printing plate based on heat mode recording, a hydrophobic image recording layer is provided on a hydrophilic substrate, and is subjected to heat mode exposure in the form of an image. A method has been proposed in which the dispersibility is changed and, if necessary, the non-image portion is removed by wet development. For example, JP-B-46-27919 discloses that an original plate provided with a recording layer containing a saccharide, a melamine formaldehyde resin, or the like, whose solubility is improved by heat on a hydrophilic support, is subjected to heat mode recording. A method for obtaining a printing plate is disclosed. Since the disclosed technology and the conventional plate making technology of heat mode recording disclosed generally have insufficient heat sensitivity, the sensitivity to heat mode scanning exposure is insufficient. The hydrophobic / hydrophilic discrimination of the part, that is, the discriminability is also small, and these limits the practicality.

As a means for solving the problem, a method of scattering and removing the image layer of the irradiated portion by the action of heat by irradiation of high-power laser light (called ablation) is also described in, for example, WO98 / 40212 and WO98 / 347.
No. 96 and JP-A-6-199064. Although this method certainly has a high degree of discrimination between the irradiated area and the non-irradiated area where the heat is completely scattered, dirt on the apparatus due to scattered matter, dirt on the printing surface impairs the operation and print quality of the apparatus, Often, the heat of the irradiating light does not reach the deep part of the image recording layer, and there is a phenomenon that the bottom of the image layer near the support remains without being scattered. Therefore, countermeasures are desired.

As a technique for avoiding this drawback, even if an image is formed by light irradiation in a heat mode, a simple change utilizing a change in the degree of hydrophilicity / hydrophobicity of the surface due to heat, that is, a change in polarity, without relying on ablation. As a plate making method, for example, a method is known in which a thermoplastic polymer such as a hydrophobic wax or a polymer latex is added to a hydrophilic layer, and phase separation is performed on the surface by heat to make the surface hydrophobic.
No. 7, JP-A-58-199153, US Pat.
864, WO99 / 4974, etc.
One direction of the discrimination improvement means is suggested. However, these disclosed technologies are desired to be improved due to insufficient discriminability, insufficient heat melting sensitivity, and insufficient printability due to insufficient hydrophilicity.

[0009]

[0006] Sufficient discrimination between an image portion and a non-image portion is a fundamental important characteristic directly linked to improvement of both printing quality such as print stain and inking property and printing durability. Therefore, a plate making method having both discriminability and simplicity of plate making work, especially plate making with high discrimination, sufficient sensitivity, no development processing required, and plate making in heat mode, printing durability and The development of a method with excellent meat properties is desired.

The present inventors have previously responded to the above-mentioned demands by applying heat mode light irradiation to a layer containing particles (hydrophobic precursor) that exhibits hydrophobicity by the action of heat. (Japanese Patent Application No. 2000-141481).
This method eliminates the deficiencies of the above-described method of recording by ablation, and achieves both the simplicity of plate making and the discrimination of images / non-images. In this regard, it was not always sufficient. Therefore, there is still a need for a lithographic printing plate having both plate simplicity and image recognizability, and also having excellent film strength and printing durability.

An object of the present invention is to improve the performance by solving the above-mentioned weak points of the heat mode plate making method using a hydrophobizing precursor. That is, an object of the present invention is to provide a simple plate-making process without the need for a developing process, and a plate-making process which can be directly mounted on a printing machine. To provide a heat-mode type lithographic printing original plate having high image recording layer strength and excellent printing durability.

[0012]

Means for Solving the Problems In order to solve the above problems, the present inventors have developed means for stabilizing the dispersion of precursor particles and a binder in a hydrophilic image recording layer containing a hydrophobic precursor. After diligent studies, the present inventors have found a remarkable effect by applying a kind of modification to the surface of the precursor particles. Based on this fact, they have further studied and completed the present invention. That is, the present invention is as follows.

1. A hydrophilic image recording layer which contains a hydrophobizing precursor having a hydrophilic graft chain on its surface in a hydrophilic binder resin and becomes hydrophobic by heat is provided on a support. Lithographic printing plate.

2. 2. The lithographic printing original plate as described in 1 above, wherein the photothermal conversion agent is contained in at least one of the image recording layer and the adjacent layer.

3. 3. The lithographic printing original plate as described in 1 or 2 above, wherein the photothermal conversion agent is contained in a hydrophobic precursor. 4. 4. The lithographic printing original plate as described in any one of the above items 1 to 3, wherein the support is a plastic film.

[0016] The hydrophobizing precursor is a particle dispersion in which the vicinity is rendered hydrophobic by the action of heat, such as thermal melting, thermal destruction, thermal crosslinking, and thermal decomposition. The feature of the lithographic printing plate precursor of the present invention lies in the hydrophobizing precursor, and the hydrophobizing precursor of the present invention has a hydrophilic graft chain on its surface, and is made of thermoplastic, thermo-crosslinkable or heat-curable. It is a reactive polymer fine particle. A hydrophilic graft chain is a graft group in which the ends of a hydrophilic polymer chain are bonded to the surface of a hydrophobizing precursor. The graft chains firmly bind the hydrophobized precursor particles to the hydrophilic medium (binder) of the image recording layer and maintain the mechanical strength of the image recording layer. Further, when the image recording layer is irradiated with heat-mode imagewise light, the hydrophobized precursor in the irradiated area is thermally melted to form an ink-accepting hydrophobic surface. Since the boundary portion of the region is firmly bonded to the hydrophilic medium (binder) by the graft chain, the film strength is maintained even in the image portion, and the film strength is maintained in both the image region and the non-image region. As a result, the printing durability can be improved.

In the printing original plate of the present invention, the heat-sealed material of the hydrophobizing precursor forms an imagewise hydrophobic region in the portion of the image recording layer which has been subjected to the heat, and the printing quality is excellent in discrimination. To achieve. Moreover, since the polarity is changed only by the application of heat and the ink becomes receptive and the print screen is formed, the plate-making process requires:
It is simple and does not require development processing. Further, because the hydrophilic graft chains are strongly fixed to the medium of the hydrophilic binder both of the hydrophobized precursor particles of the non-image portion and the heat-melted region of the image portion, the film strength and In addition to the improvement in printing durability, the discrimination between the image portion and the non-image portion is also high, and a printing original plate satisfying the object of the present invention is realized.

[0018]

Embodiments of the present invention will be described below in detail. [Image Recording Layer] In the present invention, image recording is performed by the action of heat having an image-like distribution. The application of heat to the image recording layer can be performed by either direct drawing using a thermal head or drawing by imagewise irradiation of light-to-heat converting light (heat mode). In the former case, the printing plate may not contain a photothermal conversion agent. In the latter case, that is, in the case of light irradiation in a heat mode, a photothermal conversion agent is contained in a printing original plate. The photothermal conversion agent can be contained in at least one of the image recording layer, the adjacent layer (for example, an overcoat layer or a heat insulating layer) or the support. A preferred embodiment is an addition to the image recording layer, which is advantageous in that the heat transfer efficiency to the hydrophobizing precursor is high, but further reduces the heat utilization effect by adding it to a heat insulating layer provided thereunder. It is also preferable to further increase. When the light-to-heat conversion agent is contained in the image recording layer, it may be contained in the hydrophilic medium of the binder, but in another embodiment, it may be contained in the hydrophobic precursor particles.

The structure and operation of the printing original plate of the present invention will be further described with reference to the schematic diagram of FIG. FIG. 1 is a schematic diagram showing the outline of the configuration of a lithographic printing plate precursor according to the present invention and the process of producing a printing plate using the lithographic printing plate. An original printing plate 1 according to the present invention shown on the left side of FIG. 1 includes a support 2, a heat insulating layer 3 provided thereon, and an image recording layer 4 coated on the heat insulating layer 3.
Consists of The image recording layer 4 includes a light-to-heat conversion agent 5 that converts the polarity of the vicinity with light-to-heat conversion, and a hydrophilic graft chain 8 on the surface.
And a hydrophilic binder layer containing a hydrophobic precursor 6 which is composed of polymer fine particles having the following formula: However, the provision of the heat insulating layer 3 and the inclusion of the photothermal conversion agent 5 in the image recording layer 4 are typical embodiments of the present invention, but are not essential components of the present invention. The photothermal conversion agent 5 of the image recording layer 4 is, for example, fine metal silver particles. In the printing plate 11 shown on the right side of FIG. 1, the hydrophobizing precursor 6 supporting the photothermal conversion agent particles 5 is thermally melted by the irradiation of the laser beam 7 shown by the arrow above the original plate 1 on the left side. This indicates that the layer becomes the deposition layer 15 and a hydrophobic region is formed on the surface of the irradiated region of the image recording layer. Thermal fusion layer 15
Have a hydrophilic graft chain 8 that the original hydrophobizing precursor 6 has and form a strong image area in a hydrophilic medium.

The image-recording layer according to the present invention contains a hydrophilic resin as a binder, and contains, as an essential constituent, a hydrophobizing precursor comprising the above-mentioned polymer fine particles having a hydrophilic graft chain. As a light-to-heat conversion agent. The light-to-heat conversion agent is not an essential component of the image recording layer since it may be added to the adjacent layer or may be contained in the support as described above. Is a photosensitive layer and is often a heat-sensitive layer, so that a photothermal conversion agent is also described in this section. Hydrophobic precursor itself or its heat-melted hydrophobic region is surrounded by hydrophilic graft chains and is stably retained in the hydrophilic resin as binder, improving the film strength of the image recording layer itself As a result, the printing durability is increased and the on-press developability is also improved. Hereinafter, the components of the image recording layer will be sequentially described.

(Hydrophobic Precursor Having a Hydrophilic Graft Chain According to the Present Invention) The polymer fine particles into which the hydrophilic graft chain according to the present invention is introduced are generally known as a method for synthesizing a graft polymer. It can be manufactured using a known method. Specifically, the synthesis of graft polymers is described in “Graft Polymerization and Its Applications” by Fumio Ide, published in 1977. , Kyoritsu Shuppan Co., Ltd. (199
5). The synthesis of the graft polymer is basically as follows. 1. polymerize the branch monomer from the backbone polymer; 2. bonding a branch polymer to the trunk polymer; It can be divided into three methods of copolymerizing a branch polymer with a trunk polymer (macromer method). Among these three methods, the hydrophilic layer of the present invention can be prepared by using any of the three methods, but the macromer method 3 is excellent particularly from the viewpoint of production suitability and control of the film structure.

Synthesis and microparticulation of a graft polymer using a macromer are described in "New Polymer Experimental Science 2, Synthesis and Reaction of Polymers", edited by The Society of Polymer Science, Kyoritsu Shuppan Co., Ltd., 199.
5. "Yamashita Yu et al., Macromonomer Chemistry and Industry", IPC 1989, supervised by Naoya Ogata et al., "Design and Future Prospects of Functional Supramolecules", CMC 19
98.

Specifically, as the hydrophilic monomer, (meth) acrylic acid or its alkali, amine salt, itaconic acid or its alkali, amine salt, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N- Monomethylol (meth) acrylamide, N-
Dimethylol (meth) acrylamide, 3-vinylpropionic acid or its alkali, amine salt, vinylsulfonic acid or its alkali, amine salt, 2-sulfoethyl (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, 2-acrylamide- Hydroxyl group such as 2-methylpropanesulfonic acid, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate, allylamine or a mineral acid salt thereof, carboxyl group or a salt thereof, sulfonic acid group or a salt thereof, phosphoric acid or a salt thereof, and amide A hydrophilic macromer can be synthesized according to a method described in a literature using at least one kind of a hydrophilic monomer having a hydrophilic group such as a group, an amino group, and an ether group.

Particularly useful among the hydrophilic macromers used in the present invention are macromers derived from monomers having a carboxyl group such as acrylic acid and methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, vinyl Sulfonic acid-based macromers derived from monomers of styrene sulfonic acid and salts thereof, amide-based macromers derived from N-vinylcarboxylic acid amide monomers such as N-vinylacetamide, N-vinylformamide, hydroxyethyl methacrylate, hydroxyethyl Macromers derived from hydroxyl-containing monomers such as acrylates and glycerol monomethacrylate; Macromers derived from Kokishi groups or ethylene oxide group-containing monomer. Further, a monomer having a polyethylene glycol chain or a polypropylene glycol chain can also be usefully used as the macromer of the present invention.

The useful molecular weight of these macromers is in the range of 400 to 100,000, and the preferred range is 1000 to 5
10,000, a particularly preferred range is from 1500 to 20,000. When the molecular weight is less than 400, self-dispersing polymer fine particles cannot be formed, and when the molecular weight is more than 100,000, the polymerizability with the copolymerizable monomer forming the main chain becomes poor. After synthesizing these hydrophilic macromers, one method of preparing the polymer microparticles into which the hydrophilic graft chains of the present invention have been introduced is to homopolymerize the above-mentioned hydrophilic macromer in an aqueous solvent or to form the core of the polymer microparticles. It can be obtained by copolymerization with another monomer. The mechanism of fine particle generation is as follows: first, the oligomer of the hydrophobic part becomes the nucleus, and the hydrophobic part of the macromer also aggregates in the core to form a fine particle nucleus having a hydrophilic macromer chain on the surface, while absorbing the hydrophobic comonomer. grow up. In the water-dispersible polymer fine particles obtained by this method, macromer chains are accumulated on the surface of the fine particles, so that various fine particles can be easily synthesized.

Next, the hydrophobic core portion will be described. Hydrophobic and heat-fusible polymer fine particles constituting the core portion of the hydrophobizing precursor composed of polymer fine particles having a hydrophilic graft chain include thermoplastic polymer fine particles, thermosetting polymer fine particles, and heat-reactive functional groups. Selected from polymer fine particles having the same.

The thermoplastic fine particle polymer suitable for the present invention is described in Research Disclosure No. 33 of January 1992.
303, JP-A-9-12387, 9-131
No. 850, No. 9-171249, No. 9-17
Suitable examples include thermoplastic fine particle polymers described in 1250 and EP931647. Specific examples include ethylene, styrene,
Examples thereof include homopolymers or copolymers of monomers such as vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, and vinyl carbazole, and mixtures thereof. Among them, polystyrene and polymethyl methacrylate are more preferable.

Examples of the thermosetting resin suitable for the present invention include resins having a phenol skeleton, urea-based resins (for example, urea derivatives such as urea or methoxymethylated urea resinified with aldehydes such as formaldehyde), and melamine. Examples include a series resin (for example, melamine or a derivative thereof resinified with an aldehyde such as formaldehyde), an alkyd resin, an unsaturated polyester resin, a polyurethane resin, and an epoxy resin.

Suitable resins having a phenol skeleton include, for example, phenol resins obtained by resinifying phenol, cresol and the like with aldehydes such as formaldehyde, hydroxystyrene resins, and phenol skeletons such as N- (p-hydroxyphenyl) methacrylamide. A methacrylamide or acrylamide resin having
Examples include methacrylate or acrylate resins having a phenol skeleton such as-(p-hydroxyphenyl) methacrylate. Among them, particularly preferred are a resin having a phenol skeleton, a melamine resin, a urea resin and an epoxy resin.

As a method for synthesizing such fine particles, these compounds are dissolved in a water-insoluble organic solvent, mixed and emulsified with an aqueous solution containing a hydrophilic macromer, and further heated to remove the organic solvent. There is a method of solidifying into fine particles. Further, when the thermosetting resin is synthesized, fine particles may be formed. However, it is not limited to these methods.

The polymer fine particles having a heat-reactive functional group used in the present invention include an ethylenically unsaturated group (for example, an acryloyl group, a methacryloyl group, a vinyl group, and an allyl group) for performing a polymerization reaction, and an isocyanate for performing an addition reaction. Group or its block, and a functional group having an active hydrogen atom as its reaction partner (eg, amino group, hydroxyl group, carboxyl group, etc.), an epoxy group which also performs an addition reaction, and an amino group, carboxyl group as its reaction partner Alternatively, a hydroxyl group, a carboxyl group and a hydroxyl group or an amino group for performing a condensation reaction, and an acid anhydride and an amino group or a hydroxyl group for performing a ring-opening addition reaction can be exemplified. However, a functional group that performs any reaction may be used as long as a chemical bond is formed.

The fine particle polymer having a thermoreactive functional group used in the image recording layer of the present invention includes an acryloyl group,
Examples thereof include a methacryloyl group, a vinyl group, an allyl group, an epoxy group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, an acid anhydride and those having a group protecting them. The introduction of these functional groups into the polymer particles is preferably carried out during polymerization,
The polymerization may be carried out by utilizing a polymer reaction.

When introduced at the time of polymerization, it is preferable to carry out emulsion polymerization or suspension polymerization of monomers having these functional groups. Specific examples of the monomer having such a functional group include allyl methacrylate, allyl acrylate, vinyl methacrylate, vinyl acrylate, glycidyl methacrylate, glycidyl acrylate, and 2-
Block isocyanate with isocyanate ethyl methacrylate or its alcohol, block isocyanate with 2-isocyanate ethyl acrylate or its alcohol, 2-aminoethyl methacrylate, 2-aminoethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, Examples include, but are not limited to, acrylic acid, methacrylic acid, maleic anhydride, bifunctional acrylate, bifunctional methacrylate, and the like. Examples of the monomer having no heat-reactive functional group copolymerizable with these monomers include, for example, styrene, alkyl acrylate, alkyl methacrylate, acrylonitrile, and vinyl acetate. The monomer is not limited to these as long as it has no monomer. As the polymer reaction used when the heat-reactive functional group is introduced after the polymerization, for example, WO96-34316
The polymer reaction described in Japanese Patent Application Laid-Open No. H10-260, can be mentioned. The coagulation temperature of the fine particle polymer having a thermoreactive functional group is preferably 70 ° C. or higher, and more preferably 100 ° C. or higher in consideration of the stability over time.

The average particle size of the fine polymer particles having a thermoplastic, thermosetting or thermoreactive core used in the present invention is preferably 0.01 to 20 μm.
The thickness is more preferably from 0.05 to 10 μm, particularly preferably from 0.1 to 5.0.
μm is optimal. Within this range, good resolution and stability over time can be obtained. The added amount of the polymer fine particles having a hydrophilic graft group is 10% of the solid content of the image recording layer.
It is preferably at least 20 mass%, more preferably at least 20 mass%.

(Binder) The binder is preferably a hydrophilic resin or a hydrophilic metal oxide having a gel-like structure formed by sol-gel conversion. As the hydrophilic resin, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl, carboxymethyl and the like are preferable.

Specific examples of the hydrophilic resin include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, 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 having a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight. Hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral , May include polyvinyl pyrrolidone, homopolymers and copolymers of acrylamide, homopolymers and polymers of methacrylamide, the N- methylol acrylamide homopolymers and copolymers, and the like.

The hydrophilic resin may be crosslinked and used as a crosslinking agent. Examples of the crosslinking agent include aldehydes such as glyoxal, melamine formaldehyde resin, urea formaldehyde resin, N-methylolurea, N-methylolmelamine, and methylolated polyamide. Methylol compounds such as resins, active vinyl compounds such as divinyl sulfone and bis (β-hydroxyethylsulfonic acid), epichlorohydrin and polyethylene glycol k-diglycidyl ether, polyamides, polyamines, epichlorohydrin adducts, and polyamide epichlorohydrin Epoxy compounds such as resins, ester compounds such as monochloroacetate and thioglycolate, polycarboxylic acids such as polyacrylic acid and methyl vinyl ether / maleic acid copolymer, boric acid, titani Sulfate, Cu, Al, S
Examples include inorganic crosslinking agents such as n, 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 image recording layer of the present invention can contain an inorganic hydrophilic binder resin formed by sol-gel conversion. A preferred sol-gel conversion binder resin is such that the bonding group coming from the polyvalent element forms a network structure via an oxygen atom, and at the same time, the polyvalent metal has an unbonded hydroxyl group or an alkoxy group. Is a resin having a resin-like structure, and is in a sol state at a stage where there are many alkoxy groups and hydroxyl groups, and the network-like resin structure becomes strong as the ether bonding proceeds. The polyvalent bonding element of the compound having a hydroxyl group or an alkoxy group that undergoes sol-gel conversion is aluminum, silicon, titanium, zirconium, or the like, and any of these can be used in the present invention. Among them, more preferred is a sol-gel conversion system using silicon, and particularly preferred is a system containing a silane compound having at least one silanol group and capable of sol-gel conversion. The sol-gel conversion system using silicon will be described below. The sol-gel conversion system using aluminum, titanium, and zirconium can be implemented by substituting silicon for each element described below with each element.

The sol-gel conversion binder resin is preferably a resin having a siloxane bond and a silanol group, and the image recording layer of the present invention is a sol-based coating solution containing a compound having at least one silanol group. In the process of coating and drying, the silanol groups are condensed and gelled, so that the siloxane skeleton structure is formed.

The image recording layer containing the sol-gel conversion binder resin may be combined with the hydrophilic resin or the cross-linking agent for the purpose of improving physical properties such as film strength and film flexibility and coating properties. It is also possible to use them together.

The siloxane resin forming a gel structure is represented by the following general formula (I), and the silane compound having at least one silanol group is represented by the following general formula (II).
The substance added to the image recording layer does not necessarily need to be a silane compound of the general formula (II) alone. May be a mixture.

[0042]

Embedded image

The siloxane resin of the general formula (I) is formed by a sol-gel conversion from a dispersion containing at least one silane compound represented by the general formula (II). Here, at least one of R ^{01 to} R ⁰⁸ in the general formula (I) represents a hydroxyl group, and the other represents an organic residue selected from the symbols R ⁰ and Y in the general formula (II).

Formula (II) (R ⁰ ) _n Si (Y) _4-n

Here, R ⁰ represents a hydroxyl group, a hydrocarbon group or a heterocyclic group. Y is a hydrogen atom, a halogen atom, -OR
¹ , —OCOR ² , or —N (R ³ ) (R ⁴ ).
R ¹ and R ² each represent a hydrocarbon group, and R ³ and R ⁴ may be the same or different and represent a hydrocarbon group or a hydrogen atom. n represents 0, 1, 2 or 3.

The hydrocarbon group or heterocyclic group represented by R ⁰ is, for example, a linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted (for example, methyl group, ethyl group, propyl group, butyl group). Group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, etc .; The group substituted by these groups includes a halogen atom (a chlorine atom, a fluorine atom, a bromine atom), a hydroxyl group , Thiol group, carboxyl group, sulfo group, cyano group, epoxy group, -OR 'group (R' is a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, a hexyl group,
Octyl, decyl, propenyl, butenyl, hexenyl, octenyl, 2-hydroxyethyl,
3-chloropropyl group, 2-cyanoethyl group, N, N-
Dimethylaminoethyl group, 2-bromoethyl group, 2-
(Showing (2-methoxyethyl) oxyethyl group, 2-methoxycarbonylethyl group, 3-carboxyethyl group, 3-carboxypropyl group, benzyl group, etc.),

A —OCOR ″ group (R ″ represents the same content as the above R ′), a —COOR ″ group, a —COR ″ group, and —N
An (R ′ ″) (R ′ ″) group (R ″ ′ represents the same content as a hydrogen atom or the aforementioned R ′ and may be the same or different), −
NHCONHR '' group, -NHCOOR '' group, -Si
(R ″) ₃ groups, —CONHR ″ groups and the like. These substituents may be substituted plurally in the alkyl group. A linear or branched alkenyl group having 2 to 12 carbon atoms which may be substituted (for example, vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, octenyl group, decenyl group, dodecenyl group, etc .; Examples of the group substituted with the group include those having the same contents as the group substituted with the alkyl group), an aralkyl group having 7 to 14 carbon atoms which may be substituted (for example, benzyl group, phenethyl group,
3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group and the like; examples of the group substituted with these groups include those having the same contents as the groups substituted with the alkyl group. Good), an alicyclic group having 5 to 10 carbon atoms which may be substituted (for example, cyclopentyl group,
A cyclohexyl group, a 2-cyclohexylethyl group, a norbornyl group, an adamantyl group, and the like; examples of the group substituted with these groups include those having the same contents as the groups substituted with the alkyl group, and a plurality of groups may be substituted. ), Carbon number 6
To 12 optionally substituted aryl groups (e.g., phenyl group, naphthyl group, examples of the substituent include those having the same contents as the groups substituted by the alkyl group, and a plurality of substituents may be substituted. ) Or a condensed heterocyclic group containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom (for example, a pyran ring, a furan ring, a thiophene ring, a morpholine ring, a pyrrole ring, Thiazole ring, oxazole ring, pyridine ring, piperidine ring,
A pyrrolidone ring, a benzothiazole ring, a benzoxazole ring, a quinoline ring, a tetrahydrofuran ring, or the like, which may contain a substituent. Examples of the substituent include those having the same contents as the group substituted with the alkyl group, and a plurality of the groups may be substituted.).

In the general formula (II), -OR ¹ group of Y, -OCO
Examples of the substituent of the R ² group or —N (R ³ ) (R ⁴ ) group include the following substituents. In the —OR ¹ group, R ¹ represents an optionally substituted aliphatic group having 1 to 10 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, a hexyl group, a pentyl group, an octyl group, Nonyl group,
Decyl group, propenyl group, butenyl group, heptenyl group,
Hexenyl group, octenyl group, decenyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2-methoxyethyl group, 2- (2-methoxyethyl) oxyethyl group, 2- (N, N-dimethylamino) ethyl group , 2-methoxypropyl, 2-cyanoethyl, 3-methyloxypropyl, 2-chloroethyl, cyclohexyl, cyclopentyl, cyclooctyl, chlorocyclohexyl, methoxycyclohexyl, benzyl, phenethyl, dimethoxybenzyl Group, methylbenzyl group, bromobenzyl group and the like).

In the —OCOR ² group, R ² is an aliphatic group having the same contents as R ¹ or an aromatic group having 6 to 12 carbon atoms which may be substituted (the aromatic group is exemplified by the above-mentioned aryl group of R) The same as those described above). Also, -N (R
³ ) In the (R ⁴ ) group, R ³ and R ⁴ may be the same or different from each other, and each may be a hydrogen atom or an aliphatic group having 1 to 10 carbon atoms which may be substituted (for example, the aforementioned —OR ¹ And those having the same contents as R ^{1 of the} group). More preferably, the sum of the carbon numbers of R ³ and R ⁴ is within 16 or less. Specific examples of the silane compound represented by the general formula (II) include the following, but are not limited thereto.

Tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetran-propylsilane, methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrichlorosilane, ethyltrimethoxysilane, ethyl Triethoxysilane, n-propyltrichlorosilane, n-propyltrimethoxysilane, n-hexyltrimethoxysilane, n-decyltrimethoxysilane, phenyltrichlorosilane, phenyltrimethoxysilane, dimethoxyditriethoxysilane, dimethyldichlorosilane, Dimethyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, triethoxyhydrosilane, trimethoxyhydrosilane, vinyl tric Rushiran, vinyltrimethoxysilane, trifluoropropyl trimethoxysilane, .gamma.
Glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxyxypropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-amino Propyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like.

In the image recording layer of the present invention, together with the silane compound of the general formula (II), a metal compound such as Ti, Zn, Sn, Zr, or Al which can be formed into a film by binding to a resin during sol-gel conversion. Can be used in combination. As the metal compound used, for _{example, Ti (OR '') 4} , TiCl 4, Zn (OR '') 2, Zn (CH 3 CO
CHCOCH ₃ ) ₂ , Sn (OR '') ₄ , Sn (CH ₃ COCHCOCH ₃ ) ₄ , Sn (OCO
_{R '') 4, SnCl 4} , Zr (OR '') 4, Zr (CH 3 COCHCOCH 3) 4, (NH 4) 2
ZrO (CO ₃ ) ₂ , Al (OR ″) ₃ , Al (CH ₃ COCHCOCH ₃ ) _{3 and the} like. Here, R ″ represents a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or the like.

Further, in order to accelerate the hydrolysis and polycondensation reaction of the compound represented by the general formula (II) and the metal compound used in combination, it is preferable to use an acid catalyst or a basic catalyst in combination. As the catalyst, an acid or basic compound used as it is or in a state of being dissolved in a solvent such as water or alcohol (hereinafter referred to as an acidic catalyst or a basic catalyst, respectively) is used. The concentration at that time is not particularly limited, but when the concentration is high, the rate of hydrolysis and polycondensation tends to increase. However, when a highly concentrated basic catalyst is used, a precipitate may be formed in the sol solution. Therefore, the concentration of the basic catalyst is preferably 1 N (concentration conversion in an aqueous solution) or less.

Specific examples of the acidic catalyst include hydrohalic acids such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid, carboxylic acids such as formic acid and acetic acid, and benzenesulfonic acid. Sulfonic acid. Specific examples of the basic catalyst include, but are not limited to, ammoniacal bases such as aqueous ammonia, and amines such as ethylamine and aniline.

The image recording layer using the sol-gel method described above is particularly preferred for the present invention. For more details on the above-mentioned sol-gel method, see "Sol-gel method science" by Agio Sakuhana, published by Agune Shofusha Co., Ltd. (1988); (1992
Year).

The amount of the hydrophilic resin added to the image recording layer is preferably from 5 to 70% by mass of the solid content of the image recording layer, and from 5 to 50% by mass.
% By mass is more preferred.

(Photothermal conversion agent) The image recording layer of the present invention and / or
Or an adjacent layer or an undercoat layer (described in many embodiments because the image recording layer is a heat-sensitive layer containing a photothermal conversion agent)
Contains a photothermal conversion agent that absorbs light and generates heat. The substance that can be used as the photothermal conversion agent is not particularly limited as long as it absorbs light and converts it into heat and emits it. Any conventionally known substance can be used. A dye capable of effectively absorbing the wavelength of light in the wavelength region from ultraviolet to near infrared and efficiently converting it to heat energy is preferably used. In a particularly preferred embodiment of the present invention, heat is generated by irradiation with a semiconductor laser beam.
A near-infrared absorber that shows an absorption maximum at 0 nm and has no or small absorption in the visible region, and metal fine particles, metal compound fine particles, or carbon fine particles that can convert light absorbed in the above region into heat without the absorption maximum. Is preferred.

As pigments, commercially available pigment and color index (CI) handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977), “Latest Pigment Application Technology” (CMC
Publishing, 1986), "Printing ink technology" (CMC Publishing, 198
4th edition) can be used.

Examples of the types of pigments include black pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bound pigments. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelated azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments And quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like.

These pigments may be used without surface treatment, or may be used after surface treatment. The method of surface treatment includes a method of surface-coating a hydrophilic resin or a lipophilic resin,
A method of attaching a surfactant, a method of bonding a reactive substance (for example, silica sol, alumina sol, a silane coupling agent, an epoxy compound, an isocyanate compound, and the like) to the surface of the pigment are considered. The above surface treatment method,
It is described in "Properties and Applications of Metal Soaps" (Koshobo), "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986). Among these pigments, those that absorb infrared rays are preferred because they are suitable for use in lasers that emit infrared rays. Carbon black is preferred as such an infrared absorbing pigment,
Carbon black whose surface is coated with a hydrophilic resin or silica sol so as to be easily dispersed in a water-soluble or hydrophilic resin and not impairing the hydrophilicity is particularly preferable. 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 the dye, commercially available dyes and literatures (for example, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, published in 1970,
"Chemical Industry", May 1986, p. 45-51 "Near-infrared absorbing dyes", "Development and market trends of functional dyes in the 1990s", Chapter 2 2.
Known dyes described in Section 3 (CMC, 1990) or patents can be used. Specifically, infrared absorbing dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, polymethine dyes, and cyanine dyes are preferred.

Further, for example, Japanese Patent Application Laid-Open No. 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
No. 744, etc .; squarylium dyes described in JP-A-58-112792, etc .; 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.

Further, US Pat.
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 medium such as a hydrophilic resin of the image recording layer is a water-soluble dye, and specific examples are shown below.

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When the photothermal conversion agent is added to the polymer fine particles or the microcapsule inclusion of the image recording layer,
Lipophilic dyes are more preferred. Specific examples include the following dyes. Examples of a method of adding the photothermal conversion agent to the inside of the polymer fine particles include a method of emulsifying these lipophilic photothermal conversion agents in the same stage at the time of forming the fine particles such as emulsion polymerization or dispersion polymerization.

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As a specific example of the near-infrared absorbing agent when using an infrared laser, a dye is mentioned as an example. Preferred dyes are dyes and pigments having a property of absorbing infrared rays and converting them into heat energy. Preferred pigments and dyes, particularly pigments, include cyanine dyes, squarylium dyes, methine dyes, naphthoquinone dyes, quinone imine dyes, quinone diimine dyes, quinone diimine dyes, pyrylium salt dyes, naphthoquinone dyes, phthalocyanine dyes, and naphtho Examples include a rosinine dye, a dithiol metal complex dye, an anthraquinone dye, an azo dye, a trisazo dye, a porphyrin pigment, a morpholine pigment, and a phthalocyanine pigment.

Specific examples of preferred pigments and dyes include cobalt green (CI. 77335), emerald green (CI. 77410) and phthalocyanine blue.
(CI. 74100), copper phthalocyanine (CI.
74160), Ultramarine (CI. 7700)
7), navy blue (CI. 77510), cobalt purple (C.I.
I. 77360), Pariogen Red 310 (CI.7)
1155), permanent red BL (CI.711)
37), perylene red (C.I. 71140), rhodamine lake B (C.I. 45170: 2), Helio Bordeaux BL (C.I. 14830), light fast red toner R (C.I. 12455), First Scarlet VD, Resol First Scarlet G
(CI. 12315), permanent brown FG
(CI. 12480), indanthrene brilliant orange RK (CI. 59300), and red-mouthed graphite (C.I.
I. 77601), Hansa Yellow 10G (CI.1)
1710), titanium yellow (C.I.77738),
Zinc yellow (C.I. 77955), chrome yellow (C.I.
I. 77600), and various pigments used in electrostatic recording toners can also be preferably used.

In addition, malachite green oxalic acid,
Quinizarin, 2- (α-naphthyl) -5-phenyloxazole, oil pink # 312, oil green B
G, oil blue BOS, oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Co., Ltd.), basic fuchsin, m-
Cresol purple, cyano-p-diethylaminophenylacetanilide, or JP-A-62-29324
No. 7 and Japanese Patent Application No. 7-335145. Among them, copper, cobalt, such as phthalocyanine green and phthalocyanine blue,
Phthalocyanine complex salts of nickel and iron, 3,3′-ethylmesoethylnaphthothia (oxa) dicarbocyanine,
Dicarbocyanine and tricarbocyanine dyes represented by 3,3′-ethylnaphthia (oxa) tricarbocyanine and the like are preferable.

In the image recording layer of the present invention, metal fine particles can be used as a photothermal conversion agent. As the metal fine particles, any metal fine particles may be used as long as they are light-heat converting and heat-fused by light irradiation, and the metal constituting the preferable fine particles is a single metal selected from Group 8 and Group 1B, or Alloy fine particles, more preferably Ag, Au, Cu, Pt, Pd metal simple substance or alloy fine particles. The metal fine particles of the present invention can be obtained by adding an aqueous solution of the above metal salt or metal complex salt to an aqueous solution containing a dispersion stabilizer, further adding a reducing agent to form a metal colloid, and removing unnecessary salts. . Examples of the dispersion stabilizer that can be used in the present invention include carboxylic acids such as citric acid and oxalic acid and salts thereof, and polymers such as polyvinylpyrrolidone, polyvinyl alcohol, gelatin, and acrylic resins. The reducing agent that can be used in the present invention, FeSO _4, SnSO base metal salts, boron hydride compounds such as _4, formalin, dextrin, dextrose,
Rochelle salt, tartaric acid, sodium thiosulfate, hypophosphite and the like. As a method for removing salts used in the present invention, there is a method of ultrafiltration or a method of adding methanol / water or ethanol / water to a colloidal dispersion system and spontaneous sedimentation or centrifugal sedimentation to remove the supernatant. . Other known methods can be used for the production of metal fine particles. The average diameter of the metal fine particles used in the present invention is preferably 1 to 500 nm, more preferably 1 to 100 nm,
Particularly preferably, it is 1 to 50 nm. The degree of dispersion may be polydispersity, but monodispersion having a coefficient of variation of 30% or less is preferred.

Other examples of the photothermal conversion agent include fine particles of ferric oxide, ferric oxide, ferrous oxide, chromium oxide, tin-doped indium oxide, boron nitride, manganese carbonate, and other oxides of transition metal elements. Can be used. The average diameter of the metal compound fine particles used in the present invention is preferably 0.01 to 5 μm, more preferably 0.1 to 3 μm.
It is.

The amount of the light-to-heat conversion agent added to the image recording layer can be up to 30% by mass of the total solids of the image-recording layer. It is preferably from 1 to 25% by mass, particularly preferably from 2 to 20% by mass. In the case of a metal fine particle-based or metal compound-based photothermal conversion agent, the content is 5% by mass or more, preferably 10% by mass of the total solids of the image recording layer.
Above, particularly preferably 15% by mass or more. Good sensitivity is obtained within this range. These light-to-heat conversion agents can be used in combination of two or more.

(Other Constituents of Image Recording Layer) Various compounds other than those described above may be added to the image recording layer of the present invention, if necessary. For example, a polyfunctional monomer can be added to the image recording layer matrix to further improve the printing durability. Examples of the polyfunctional monomer include trimethylolpropane triacrylate propylene glycol diitaconate.

In the image recording layer of the present invention, after forming an image,
In order to make it easy to distinguish between the image area and the non-image area, a dye having a large absorption in the visible light region can be used as a colorant for the image. Specifically, Oil Yellow # 10
1, oil yellow # 103, oil pink # 312,
Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black B
S, Oil Black T-505 (all manufactured by Orient Chemical Industries, Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI)
42000), methylene blue (CI52015), etc.
And dyes described in JP-A-62-293247. Further, pigments such as phthalocyanine pigments, azo pigments, and titanium oxide can also be suitably used. The amount of addition is 0.01 to 10% by mass based on the total solid content of the coating solution for the image recording layer.

In the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor to prevent unnecessary thermal polymerization of the ethylenically unsaturated compound during preparation or storage of the coating solution for the image recording layer. . Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t
-Butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-
Methyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl-6-t-butylphenol),
N-nitroso-N-phenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to 5% by mass based on the total mass of the composition. If necessary, a higher fatty acid such as behenic acid or behenic acid amide or a derivative thereof is added to prevent polymerization inhibition by oxygen, and is unevenly distributed on the surface of the image recording layer in a drying process after coating. You may. The amount of the higher fatty acid or derivative thereof added is preferably about 0.1 to about 10% by mass of the solid content of the image recording layer.

Further, a plasticizer can be added to the image recording layer of the present invention, if necessary, to impart flexibility and the like 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.

Further, inorganic fine particles may be added to the image recording layer of the present invention. Preferred examples of the inorganic fine particles include silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate and the like. Even if they do not have light-to-heat conversion properties, they can be used for strengthening a film or enhancing interfacial adhesion by surface roughening. The content of the inorganic fine particles in the image recording layer is preferably from 1.0 to 70% by mass, more preferably from 5.0 to 50% by mass, based on the total solids of the image recording layer. The inorganic fine particles may be added as hydrophilic sol particles such as silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate or a mixture thereof.
The hydrophilic sol particles preferably have an average particle size of 10 to 50 nm, more preferably 10 to 50 nm. When the particle diameter is within this range, both the polymer fine particles and the metal fine particles of the light-to-heat conversion agent are stably dispersed in the binder resin, the film strength of the image recording layer is sufficiently maintained, and the hydrophilicity which does not easily cause printing stains is excellent. A non-image portion can be formed. Such hydrophilic sol-like particles can be easily obtained as a commercial product such as a colloidal silica dispersion.

[Heat insulation layer] The lithographic printing plate of the present invention includes:
Although the heat insulating layer is not essential, the exposure intensity can be reduced by providing the heat insulating layer between the image recording layer and the supporting body, and the exposure latitude can be advantageously increased. is there. The heat insulating layer provided as a lower layer of the image recording layer has a low thermal conductivity and has a function of suppressing heat diffusion to the support. Further, the heat insulation layer may contain a photothermal conversion agent, which generates heat by light irradiation, and is effective for improving the heat fusion sensitivity.

The heat insulating layer is made of an organic or inorganic resin. The organic or inorganic resin can be widely selected from hydrophilic or hydrophobic resins. For example, as a resin having hydrophobicity, polyethylene, polypropylene, polyester, polyamide, acrylic resin, vinyl chloride resin, pinylidene chloride resin, polyvinyl butyral resin, nitrocellulose, polyacrylate, polymethacrylate, polycarbonate, polyurethane, polystyrene, vinyl chloride resin -Vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-resin vinyl-maleic acid copolymer, vinyl chloride-acrylate copolymer, polyvinylidene chloride, vinylidene chloride-acrylonitrile copolymer And the like.

As the resin having hydrophobicity, a resin composed of an aqueous emulsion can be used. The aqueous emulsion is a hydrophobic polymer suspension aqueous solution in which particles comprising fine polymer particles and, if necessary, a protective agent for stabilizing the dispersion of the particles are dispersed in water. Specific examples of the aqueous emulsion used include vinyl polymer latex (polyacrylate, vinyl acetate,
Ethylene-vinyl acetate-based), conjugated cyanene-based polymer latex (methyl methacrylate-butadiene-based, styrene-butadiene-based, agglononitrile-butadiene-based, chloroprene-based, etc.), and polyurethane resin.

Next, examples of the hydrophilic resin include polyvinyl alcohol (PVA), modified PVA such as carboxy-modified PVA, starch and derivatives thereof, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, and alginic acid. Ammonium,
Polyacrylic acid, polyacrylate, polyethylene oxide, water-soluble urethane resin, water-soluble polyester resin, polyhydroxyethyl acrylate, polyethylene glycol diacrylate polymer, N-vinyl carboxylic acid amide polymer, casein, gelatin, polyvinyl pyrrolidone, acetic acid And water-soluble resins such as a vinyl-crotonic acid copolymer and a styrene-maleic acid copolymer.

Further, the above-mentioned hydrophilic resin is cross-linked,
It is preferable to use after curing, and as a crosslinking agent (also referred to as a water-resistant agent), aldehydes such as glyoxal, melamine formaldehyde resin, 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), epoxy compounds such as epichlorohydrin and polyethylene glycol glycidyl ether, adducts of polyamide / polyamine / epichlorohydrin, polyamide epichlorohydrin resin, and monochloroacetic acid Ester compounds such as esters and thioglycolic acid esters, polycarboxylic acids such as polyacrylic acid and methyl vinyl ether / maleic acid copolymer, boric acid, titanyl sulfate, Cu, A1, Sn, V,
An inorganic crosslinking agent such as a Cr salt, a modified polyamide-polyimide resin, and the like can be given. In addition, ammonium chloride,
A crosslinking catalyst such as a silane coupling agent and a titanate coupling agent can be used in combination.

Further, as the inorganic polymer, an inorganic matrix formed by sol-gel conversion is preferable. A system capable of sol-gel conversion preferably applicable to the present invention is:
The bonding group bonded to the polyvalent element forms a network-like structure via the oxygen atom, and at the same time, the polyvalent metal also has an unbonded hydroxyl group or an alkoxy group, and has a resin-like structure in which these are mixed. The polymer is in a sol state at a stage where there are many alkoxy groups and hydroxyl groups, and the network-like resin structure becomes strong as the ester bonding proceeds. Further, in addition to the property that the degree of hydrophilicity of the resin structure changes, it also has a function of modifying the surface of the solid fine particles by binding a part of hydroxyl groups to the solid fine particles and changing the degree of hydrophilicity. The polyvalent bonding element of the compound having a hydroxyl group or an alkoxy group that undergoes sol-gel conversion is aluminum, silicon, titanium, zirconium, or the like, and any of these can be used in the present invention. From the viewpoint of the adhesiveness to the image recording layer, a hydrophilic resin is particularly preferable among these resins.

As the light-to-heat converting substance contained in the heat insulating layer, the same substance as the light-to-heat converting agent contained in the above-mentioned image forming layer can be used.

The content of the photothermal conversion agent contained in the heat insulating layer is 2 to 95% by mass of the solid constituents. 2% by mass
Below, the calorific value is insufficient and the sensitivity is reduced, and above 95% by mass, the film strength is reduced.

In the heat insulating layer, in addition to the above-mentioned resin and light-to-heat converting agent, the physical strength of the heat insulating layer, the dispersibility of the constituents of the layer, the applicability, and the hydrophilicity of the hydrophilic layer are improved. Various objective compounds can be added for reasons such as an improvement in adhesion to the compound. These additives include, by way of example, the following:

<Inorganic Fine Particles> As the inorganic fine particles to be added to the heat insulating layer, the same inorganic fine particles as those added to the above-described image recording layer can be added, and the same effects can be obtained. The content when the inorganic fine particles are added to the heat insulating layer is also in the same range as when it is added to the image recording layer.

<Surfactant> Those described as those which can be added to the image recording layer can also be used for the heat insulating layer. The addition amount is also the same as the range described for the image recording layer.

[Overcoat layer] In the lithographic printing plate precursor of the present invention, a water-soluble overcoat layer may be provided on the image recording layer, if necessary, to prevent contamination of the surface of the image recording layer by a lipophilic substance. it can. The water-soluble overcoat layer used in the present invention can be easily removed at the time of printing and contains a resin selected from water-soluble organic polymer compounds. As the water-soluble organic polymer compound used herein, a film formed by coating and drying has a film-forming ability, specifically, polyvinyl acetate (having a hydrolysis rate of 65% or more) and polyacrylic. Acid, its alkali metal salt or amine salt, polyacrylic acid copolymer,
Alkali metal salt or amine salt, polymethacrylic acid, alkali metal salt or amine salt, polymethacrylic acid copolymer, alkali metal salt or amine salt, polyacrylamide, copolymer thereof, polyhydroxyethyl acrylate, polyvinylpyrrolidone , A copolymer thereof, polyvinyl methyl ether, a vinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamide-2-methyl-1-propanesulfonic acid, an alkali metal salt or an amine salt thereof, and poly-2-acrylamide. -2-methyl-1-propanesulfonic acid copolymer, an alkali metal salt or an amine salt thereof, gum arabic, a cellulose derivative (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.), a modified product thereof, white Dextrin, pullulan, enzymatically degraded etherified dextrin and the like can be mentioned. Further, according to the purpose, two or more of these resins can be used in combination.

The above-mentioned water-soluble photothermal conversion agent may be added to the overcoat layer. Furthermore, in the case of aqueous solution application, a nonionic surfactant such as polyoxyethylene nonylphenyl ether and polyoxyethylene dodecyl ether can be added to the overcoat layer for the purpose of ensuring uniformity of application. . Dry coating amount of the overcoat layer, 0.1 to 2.0 g / m ² is preferred. Within this range, the surface of the image recording layer can be satisfactorily prevented from being stained by a lipophilic substance such as a fingerprint stain without impairing the on-press developability.

[Coating] The above-described image recording layer, heat insulating layer and overcoat layer are prepared by mixing the respective constituent components and applying a prepared coating solution to a support by using any of the conventionally known coating methods. Apply and dry to form a coating layer. Various methods can be used as the method of coating, for example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating,
Examples include blade coating and roll coating.

In the present invention, a surfactant for improving coating properties, for example, the above-mentioned surfactant can be added to the image recording layer, the heat insulating layer and the overcoat layer of the lithographic printing original plate. . The preferred addition amount of the coating aid is
It is 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass of the total solids of each layer. Also apply,
The coating amount (solid content) of the image recording layer obtained after drying varies depending on the application, but is preferably 0.1 to 30 g / m ² , and 0.3 to 10 g for a general lithographic printing plate.
/ M ² is more preferred.

[Support] Next, the support on which the image recording layer is coated will be described. A dimensionally stable plate is used for the support. Examples of the support that can be used in the present invention include paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, nickel, stainless steel, etc.), plastic Films (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 films on which the above-mentioned metals are laminated or vapor-deposited.

Preferred supports are polyester film, aluminum, or SUS which is not easily corroded on a printing plate.
It is a steel plate, and among them, an aluminum plate which has good dimensional stability and is relatively inexpensive is preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include:
Silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by mass or less. Particularly preferred aluminum in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element.
As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the support used in the present invention is approximately 0.05 mm to
About 0.6 mm, preferably 0.1 mm to 0.4 mm,
Particularly preferably, it is 0.15 mm to 0.3 mm.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is performed to remove rolling oil on the surface. The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. It is performed by the method of causing. As a mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used. The chemical method is disclosed in
The method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in Japanese Patent No. 31187 is suitable. Further, as an electrochemical surface roughening method, there is a method of carrying out an alternating current or a 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. Among such surface roughening methods, in particular,
A surface roughening method which combines mechanical surface roughening and electrochemical surface roughening as described in JP-A-5-137933 is preferred because the adhesive force of the oil-sensitive image to the support is strong. The surface roughening by the above method is preferably performed in a range such that the center line surface roughness (Ra) of the surface of the aluminum plate is 0.3 to 1.0 μm. The roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide or sodium hydroxide as required, and further neutralized, and then anodized to enhance abrasion resistance if desired. Processing is performed.

As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes for forming a porous oxide film can be used. Generally, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. Can be 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 thus cannot be specified unconditionally.
~ 80 mass% solution, liquid temperature 5 ~ 70 ° C, current density 5 ~ 6
0 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 oxide film formed is
1.0 to 5.0 g / m ² , especially 1.5 to 4.0 g / m ²
It is preferable that The amount of anodized film is 1.0 g / m ²
If the amount is smaller, the printing durability becomes insufficient or the surface is easily scratched.

Among these anodizing treatments, in particular, a method of anodizing at a high current density in sulfuric acid described in British Patent No. 1,412,768 and US Pat. No. 3,511,661. The method of anodizing using phosphoric acid as an electrolytic bath described in above is preferable.

In the embodiment in which the heat insulating layer is provided, when the heat insulating layer is a resin having hydrophobicity, it is desirable to make the surface of the support hydrophobic. The surface of the support is hydrophobized by applying an undercoating liquid containing, for example, a silane coupling agent or, in some cases, a titanium coupling agent. The silane coupling agent is mainly represented by the general formula (R
O) ₃ SiR ′ (R and R ′ are an alkyl group or a substituted alkyl group). The RO group is hydrolyzed to form an OH group and is bonded to the support surface by an ether bond, and the R ′ group forms the ink. Provides a receptive hydrophobic surface.

Examples of the silane coupling agent include γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, and γ-glycoxide. There may be mentioned, for example, propyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptotrimethoxysilane, γ-ureidopropyltriethoxysilane, N- (β-aminoethyl)-(β-aminopropyl) dimethoxysilane. In order to ensure adhesion to the image recording layer, the plastic support may be subjected to a charging treatment by a known method before coating.

[Plate Making and Printing] Next, a method of making a lithographic printing plate precursor will be described. This lithographic printing plate precursor is subjected to image recording by either image recording by direct thermal drawing means such as a thermal head or optical image recording by heat-mode imagewise exposure. As a preferred embodiment in the case of optical recording in the heat mode, a wavelength of 760 to 120
A solid-state laser or semiconductor laser that emits 0-nm infrared light, high-intensity flash light such as a xenon discharge lamp, or light-heat conversion-type exposure such as infrared lamp exposure can be used.

The writing of an image may be performed by either a surface exposure method or a scanning method. In the former case, an infrared irradiation method,
This is a method of irradiating a short time light of high illuminance of a xenon discharge lamp onto an original plate to generate heat by light-heat conversion. When a surface exposure light source such as an infrared lamp is used, the preferable exposure amount varies depending on the illuminance, but usually, the surface exposure intensity before modulation with a print image is 0.1 to 10 J / cm ^2.
And more preferably 0.1 to 1 J / cm ² . When the support is transparent, exposure can be performed through the support from the back side of the support. The exposure time is preferably selected such that the above-mentioned exposure intensity is obtained by irradiation of 0.01 to 1 msec, preferably 0.01 to 0.1 msec.
When the irradiation time is long, it is necessary to increase the exposure intensity due to the competition between the heat energy generation rate and the generated heat energy diffusion rate.

In the latter case, a method is used in which a laser light source containing a large amount of infrared components is used to modulate a laser beam with an image and scan the original plate. Examples of the laser light source include a semiconductor laser, a helium neon laser, a helium cadmium laser, and a YAG laser. Irradiation can be performed with a laser having a laser output of 0.1 to 300 W. When a pulse laser is used, it is preferable to irradiate a laser having a peak output of 1000 W, preferably 2000 W. In this case, the exposure amount is preferably such that the surface exposure intensity before modulation with the printing image is in the range of 0.1 to 10 J / cm ² ,
More preferably, it is in the range of 0.3 to 1 J / cm ² . When the support is transparent, exposure can be performed through the support from the back side of the support.

The lithographic printing plate precursor of the present invention, which has been image-exposed, can be mounted on a printing press without any further processing, and can be printed by an ordinary procedure using ink and fountain solution. These lithographic printing original plates are disclosed in Japanese Patent No. 293839.
As described in No. 8, it is also possible that after mounting on a printing press cylinder, exposure is performed by a laser mounted on the printing press, followed by applying a fountain solution or ink to perform on-press development. These lithographic printing original plates can be used for printing after development using water or an appropriate aqueous solution as a developing solution.

[0105]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. [Synthesis Examples 1 to 6]

Synthesis Example 1 <Preparation of Polymer Fine Particle A> 100 g of polystyrene-g-t-butyl methacrylate, 0.8 g of 2-mercaptoethanol, 1.2 g of AIBN, 900 g of THF
Was put into a three-necked flask, and the temperature was raised to 60 ° C. while injecting nitrogen. After stirring for about 6 hours, water / methanol = 1
The reaction solution was put into a mixed solvent of 1/1 (v / v), and reprecipitation purification was performed. Next, 80 g of the hydroxyl-terminated t-butyl methacrylate oligomer thus obtained,
860.8 g of p-vinylbenzyl chloride, 316.5 g of potassium hydroxide, 1920 g of DMF, 1920 of water
g, tetrabutylphosphonium bromide (12.5 g) was placed in a three-necked flask, stirred at 30 ° C. for 72 hours, filtered, and the filtrate was poured into a mixed solvent of water / methanol = 1/1 (v / v) for reprecipitation. Purification was performed. Next, 50 g of the poly (t-butyl methacrylate) macromonomer thus obtained, 75 g of styrene, and AIBN 1.5
g and 500 g of ethanol were placed in a three-necked flask, and the temperature was raised to 60 ° C. while injecting nitrogen. Thereafter, after stirring for 48 hours, 20 ml of 5 N hydrochloric acid was added to prepare water-dispersible polymer fine particles A in which polyacrylic acid was grafted on the polystyrene surface. The solid content of the dispersion thus obtained was 11.5%, and the average particle size was 0.82 μm.

Synthesis Example 2 <Preparation of Polymer Fine Particles B> 240 g of polystyrene-g-polyethylene glycol methacryloyl-terminated polyethylene glycol (manufactured by NOF Corporation, Mn = 1000), styrene 500
g, AIBN 0.8 g, water 800 ml, ethanol 80
0 ml into a three-necked flask,
After stirring at 0 ° C. for 24 hours, diafiltration was performed to remove unreacted monomers and purification was performed. The dispersion of the water-dispersible polymer microparticles B grafted with polyethylene glycol thus obtained had a solid content of 13.5% and an average particle size of 0.35 μm.

Synthesis Example 3 <Preparation of Polymer Fine Particle C> Polymethyl acrylate
g-polyacrylamide 30 g of acrylamide was dissolved in 70 g of ethanol,
3.8 g of mercaptopropionic acid was added, and the temperature was raised to 60 ° C. in a nitrogen atmosphere, and 300 mg of AIBN was added.
The reaction was performed at 0 degrees for 6 hours. After completion of the reaction, the precipitated white solid was filtered. Further wash thoroughly with methanol, filter,
After drying, polyacrylamide having a terminal carboxylic acid was obtained. 20 g of polyacrylamide at the terminal carboxylic acid
Dissolved in 62.3 g of MSO, 62.4 m of hydroquinone
g and glycidyl methacrylate (6.71 g) were added, and the temperature was raised to 130 ° C. in a nitrogen atmosphere. Then, 504 mg of N, N-dimethyldodecylamine was added, and the mixture was reacted at 130 ° C. for 7 hours.
After reprecipitation with acetone, drying was performed to obtain methacryloyl-terminated polyacrylamide. Next, the thus obtained methacryloyl-terminated polyacrylamide macromonomer 3
g, 4.5 g of methyl acrylate in 100 parts of ethanol.
g, 100 g of water, and initiator 2,2′-azobis [2- (2-imidazolin-2-yl) propane] 11
A solution prepared by dissolving 0 mg in 20 g of water was placed under a nitrogen atmosphere for 75 minutes.
After dropping over about 2 hours at 75 ° C, the reaction was further continued at 75 ° C for 5.5 hours. Thus, water-dispersible polymer fine particles C in which polyacrylamide was grafted on the surface of polymethyl acrylate were prepared. The solid concentration of this dispersion is 1
2.2%, and the average particle size was 0.20 μm.

Synthesis Example 4 <Preparation of Polymer Fine Particle D> Polymethyl Methacrylate-g-Polyacrylacetamide The same procedure as in Synthesis Example 3 was repeated except that acrylacetamide was used instead of acrylamide used in Synthesis Example 3. Acetamide was obtained. Next, 3 g of the methacryloyl-terminated polyacrylacetamide macromonomer thus obtained and 4.5 g of methyl methacrylate were dissolved in 100 g of ethanol and 100 g of water,
Initiator 2,2'-azobis [2- (2-imidazoline-
2-yl) propane] in 20 g of water was dropped at 75 ° C. over about 2 hours under a nitrogen atmosphere, and further reacted at 75 ° C. for 5.5 hours. Thus, water-dispersible polymer fine particles D in which polyacrylacetamide was grafted on the surface of polymethyl methacrylate were prepared. The solid content concentration of this dispersion was 11.8%, and the average particle size was 0.23 μm.

Synthesis Example 5 <Preparation of Polymer Fine Particle E> Polymethylmethacrylate-g-PVP Methacryloyl was prepared in the same manner as in Synthesis Example 3 except that 1-vinyl-2-pyrrolidinone was used instead of acrylamide used in Synthesis Example 3. A terminal polyvinylpyrrolidone was obtained. next,
3 g of the methacryloyl-terminated polyvinylpyrrolidone macromonomer thus obtained and 4.5 g of methyl methacrylate were dissolved in 100 g of ethanol and 100 g of water,
Initiator 2,2'-azobis [2- (2-imidazoline-
2-yl) propane] in 20 g of water was dropped at 75 ° C. over about 2 hours under a nitrogen atmosphere, and further reacted at 75 ° C. for 5.5 hours. Thus, water-dispersible polymer fine particles E in which polyvinyl pyrrolidone was grafted on the surface of polymethyl methacrylate were prepared. The solid content concentration of this dispersion was 12.3%, and the average particle size was 0.55 μm.

Synthesis Example 6 <Preparation of Polymer Fine Particle F> Polystyrene-g-poly (4-vinyl-NN-butylpyridinium bromide) 20 g of 4-vinylpyridine, 1.0 g of 2-mercaptoethanol, 0.3 g of AIBN, 900 g of THF Was placed in a three-necked flask, and the temperature was raised to 60 ° C. while introducing nitrogen. Then, after stirring for about 6 hours, the reaction solution was poured into an ether solvent, and reprecipitation purification was performed to obtain a vinylpyridine oligomer having a terminal hydroxyl group. Subsequently, the oligomer was converted to n-
Quarterized by reacting with butyl bromide in DMF at 70 ° C. for 24 hours, further adding 5 times equivalent of vinylbenzyl chloride, 10 times equivalent of potassium hydroxide, and catalytic amount of tetrabutylphosphonium bromide, By reacting for 72 hours, a poly (4-vinyl-Nn-butylpyridinium bromide) macromonomer having a styryl terminal was obtained. 3 g of the macromonomer,
Dissolve 7 g of styrene in 40 g of ethanol and 10 g of water,
Initiator 2,2'-azobis [2- (2-imidazoline-
2-yl) propane] under a nitrogen atmosphere.
And reacted for 48 hours. In this way, water-dispersible polymer fine particles F in which quaternized polyvinylpyridine was grafted on the surface of polystyrene were prepared. The solid content concentration of this dispersion was 10.6%, and the average particle size was 0.24 μm.

Example 1 <Preparation of aluminum support> 0.01% by weight of copper, 0.03% by weight of titanium, 0.3% by weight of iron, and 0.1% by weight of silicon were added to 99.5% by weight of aluminum. A 0.24 mm-thick rolled sheet of JIS 105 aluminum material containing 20% by mass was prepared by mixing a 400-mesh aqueous suspension of pumicestone (manufactured by Kyoritsu Ceramics) with a 20% by mass aqueous suspension and a rotating nylon brush (6.1).
0-nylon) and the surface is grained,
Washed well with water. Next, after immersing in a 10% by mass aqueous solution of sodium hydroxide at 70 ° C. for 60 seconds for etching,
It was washed with running water. Further, it was neutralized with a 20% by mass aqueous solution of nitric acid and washed with water. The obtained aluminum plate was placed in a 1.0% by mass aqueous nitric acid solution (containing 0.5% by mass of aluminum nitrate) in an anode voltage of 12.7 volts, and the ratio of the amount of electricity at the cathode to the amount of electricity at the anode was 0.9. Electrolytic surface roughening treatment was performed using a current having a rectangular wave alternating waveform under the condition of an anode electricity of 160 clones / dm ² . The surface roughness of the obtained substrate was 0.1.
It was 6 μm (Ra indication). Following this processing, 40
It was immersed in a 1% by mass aqueous solution of sodium hydroxide at 30 ° C. for 30 seconds, etched, and washed with water. Next, at 55 ° C, 3
It was immersed in a 0% by mass aqueous sulfuric acid solution for 1 minute. In addition, 3
Anodizing treatment was performed in a 20% by mass aqueous sulfuric acid solution (containing 0.8% by mass of aluminum) at 5 ° C. using a direct current so that the mass of the anodized film became 2.5 g / dm ² .
This was washed with water and dried to prepare a support.

<Coating of Image Recording Layer> An aqueous coating solution having the following composition was prepared and coated on the aluminum support by a bar coater so that the dry film weight became 3.0 g / m ^2. Then, it was dried in an oven at 100 ° C. for 10 minutes. (Composition of image recording layer coating solution) Colloidal silica 20% aqueous solution 200 g Sol-gel preparation 49.5 g Polymer fine particles A 348 g Infrared absorbing dye (1) 5.00 g Water 397.5 g The sol-gel preparation used here It has the composition of (Sol-gel preparation solution: room temperature, aged for 2 hours) Tetraethoxysilane 15.0 g Ethanol 30.0 g 0.1 mol / L nitric acid 4.5 g

Infrared absorbing dye (1)

Embedded image

When the contact angle of water droplet on the surface of the obtained printing original plate was measured, it was found that the surface showed extended wetting and was very hydrophilic.

<Image formation> Trendsetter 3244V manufactured by Creo Corporation equipped with a water-cooled 40 W infrared semiconductor laser
At FS, output 8.5W, outer drum rotation speed 100rpm
m, plate surface energy 200 mJ / cm ² , resolution 240
Exposure was performed under the condition of 0 dpi, and an image area thermally fused to the exposed portion surface was formed. The contact angle of water droplets on the surface of the irradiation area of this printing plate was 112 degrees, which changed to a highly hydrophobic surface.
Thereafter, plate-making was performed without development processing.

<Printing> RYOBI-3200M
Using a CD, a 1% by volume aqueous solution of EU-3 (manufactured by Fuji Photo Film Co., Ltd.) was used as a dampening solution, and the ink was GEOS.
(N) Ink was used. First, a dampening solution was supplied, and then ink was supplied to start printing, and a high-quality printed matter was obtained with no print stains up to 10,000 sheets.

Examples 2 to 6 In the same manner as in Example 1 except that the polymer fine particles A of Example 1 were changed to polymer fine particles BF, original plates for planographic printing were produced. When the contact angle of water droplets on the surface of the obtained printing original plate was measured, all of them exhibited extended wetting and were very hydrophilic surfaces. Next, the results of similarly performing image formation and printing evaluation are shown in Table 1.

(Table 1) Example Hydrophobizing precursor Irradiation area contact angle Printing durability 2 B 102 ° 10,000 sheets 3 C 93 ° 10,000 sheets 4 D 96 ° 10,000 sheets 5 E 89 ° 10 6,000 pieces 6F 104 ° 10,000 pieces

Example 7 A plate material was prepared in the same manner as in Example 1 except that a heat insulating layer having the following composition was provided between the aluminum support and the image recording layer in Example 1.

<Preparation of Heat Insulating Layer> A coating solution having the following composition was prepared, and 1.0 g of the coating solution was coated on the anodized aluminum support.
/ M ² thick heat insulating layer was prepared. Butyral resin BM-S (manufactured by Sekisui Chemical Co., Ltd.) 10% MEK solution 59 g Carbon black dispersion (solid content 21%) 13.5 g MEK (methyl ethyl ketone) 62.7 g Next, imagewise irradiation by laser exposure and print evaluation Was done. As a result, it is possible to form an image with a smaller exposure energy (plate energy: 150 mJ / cm ² ) than in Example 1, and as in Example 1, up to 10,000 sheets are free from print stains and high quality. A print was obtained.

Example 8 An aqueous coating solution having the following composition was prepared, and a dry film thickness of 0.5 g / m ² was applied to the hydrophilic image recording layer of the printing plate precursor described in Example 7 with a bar coater. Was coated with an overcoat layer and dried in an oven at 100 ° C. for 1 minute.

(Composition of Overcoat Layer Coating Solution) Polyacrylic acid (average molecular weight: 20,000) 10% solution 350 g 2.5 g of the dye of formula (1) (1% by mass aqueous solution)

As compared with the seventh embodiment, an image can be formed with a lower exposure energy (plate energy: 120 mJ / cm ² ). Prints were obtained.

Example 9 A plate material was prepared in the same manner as in Example 1 except that the aluminum support of Example 1 was replaced with a 180 μm thick PET base. Next, imagewise irradiation by laser exposure and printing evaluation were performed. As a result, an image could be formed with a smaller exposure energy (plate energy: 150 mJ / cm ² ) than in Example 1, and as in Example 1, 10,000 images were formed.
No high-quality printed matter was obtained with no print stains on up to 0 sheets.

Example 10 <Coating of Image Recording Layer> A water-based coating solution having the following composition was prepared, and the weight of the dried film was 1.0 g / m 2 on a bar coater on the aluminum support prepared in Example 1. Coating was performed so as to be ² , and then dried in an oven at 100 ° C. for 2 minutes. (Image recording layer coating liquid composition) Polyacrylic acid (average molecular weight: 20,000) 10% aqueous solution 100 g Polymer fine particles A 739 g The infrared light absorbing dye (1) 5 g Water 156 g Lithographic printing plate,
Output 9 W, external drum rotation speed 105 rpm, plate surface energy 200 mJ by Creo Trendsetter 3244 VFS equipped with a water-cooled 40 W infrared semiconductor laser.
/ Cm ² and a resolution of 2400 dpi,
Without processing, Heidelberg printing machine SOR-
After mounting on a cylinder of M and supplying a dampening solution, ink was supplied, and paper was further supplied to perform printing. On-press development was possible for all printing plates without any problem, and 10,000 good prints were obtained.

[0127]

According to the present invention, a hydrophilic image recording layer which contains a hydrophobizing precursor having a hydrophilic graft chain on the surface thereof in a hydrophilic binder resin and becomes hydrophobic by heat is preferably provided on a support. The lithographic printing original plate of the present invention, in which an image is formed by light irradiation in heat mode, can be made only by the action of heat without the need for a development process, and can be directly mounted on a printing machine to make a plate. In addition to having the simplicity of being able to perform printing and the discriminating property with less printing stains on the printing surface, the film strength of the image recording layer is strong and the printing durability is excellent. The light-to-heat conversion agent may be contained in any of the constituent layers, but the effect of the present invention is particularly remarkable when it is contained in the image recording layer.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a typical lithographic printing original plate of the present invention and a plate making process using the same.

[Explanation of symbols]

 1. Original plate for lithographic printing 2. Support 3. Heat insulation layer (lower layer) 4. Image recording layer 5. Light-to-heat conversion agent 6. 6. Hydrophobizing precursor Laser light 8. 10. hydrophilic graft chains Print version 15. Hydrophobic region by heat fusion 21. Printing plate with exposed hydrophilic support substrate in non-image area

Continuation of front page (72) Inventor Sumaki Yamazaki 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. AA24 BA01 BA10 DA55 DA56 DA59 DA73 DA75 EA01 EA02

Claims (4)

[Claims] 1. A hydrophilic image-recording layer which contains a hydrophobic-forming precursor comprising polymer fine particles having a hydrophilic graft chain on its surface in a hydrophilic binder resin and becomes hydrophobic by heat is provided on a support. A lithographic printing plate characterized by being provided. 2. The lithographic printing plate according to claim 1, wherein a light-to-heat conversion agent is contained in at least one of the image recording layer and the adjacent layer. 3. The lithographic printing plate precursor according to claim 1, wherein the photothermal conversion agent is contained in a hydrophobic precursor. 4. The lithographic printing original plate as claimed in claim 1, wherein the support is a plastic film.