JP2002166672A - Original plate for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for a heat mode type lithographic printing plate capable of simply platemaking without necessity of developing, platemaking by directly mounting in a printer and having small scumming on a printing surface, a strong film strength of an image recording layer and excellent plate ware resistance. SOLUTION: The original plate for a lithographic printing plate comprises a hydrophilic image recording layer to become hydrophobic by a heat and containing a hydrophobic precursor having a hydrophilic graft chain on a surface and made of polymer fine particles carrying metal fine particles on a 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 for plate-making and printing without development. 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 been put into practical use. 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 lith 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 imagewise exposure of a 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 into 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 great 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 room 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 image fixation is not essential 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 into a computer-to-plate system.

[0006] As one of the preferred 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, and the solubility of the hydrophobic layer is determined. A method has been proposed in which the dispersibility is changed and the non-image area is removed by wet development as needed. For example, Japanese Patent Publication No. 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. The simple plate making technology of heat mode recording including the disclosed technology is generally insufficient in heat sensitivity, and therefore has insufficient sensitivity to heat mode scanning exposure. The hydrophobic / hydrophilic discrimination of the part, that is, the discriminability is also small, and these limits the practicality.

As a means for solving this problem, a method of scattering and removing the image layer of the irradiated portion by the action of heat by irradiating a high-power laser beam (called ablation) is also disclosed in, for example, WO98 / 40212 and WO98 / 347.
No. 96 and JP-A-6-199064. In this method, the discrimination between the irradiated area and the non-irradiated area where the heat scattering was completely performed is large, but the dirt on the device due to the scattered material, the dirt on the printing surface impairs the operation of the device and the print quality, 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 close to 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.
7, Japanese Patent No. 2938397, JP-A-9-12
No. 7683, JP-A-58-199153, US Pat.
No. 68,864, WO99 / 4974, WO99 / 1
No. 0186 proposes one direction of the discrimination improvement means. However, these disclosed technologies have insufficient discriminating properties, heat melting sensitivity is not sufficiently high, hydrophilicity is insufficient, and on-press developability is insufficient, and there is a fear of print stains. Improvement is desired.

[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, in particular, high discrimination, sufficient sensitivity, no development processing, plate making in a heat mode, printing durability during printing, 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 original plate having both plate making simplicity and image discriminating property, 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 hydrophobizing precursor. After diligent study, the inventors have found a remarkable effect by applying a kind of modification to the surface of the precursor particles. Reached. That is, the present invention is as follows.

1. An image recording layer containing a hydrophobizing precursor which becomes hydrophobic by heat is provided on a support, and the hydrophobizing precursor has a hydrophilic graft chain on its surface and a polymer carrying metal fine particles. An original plate for lithographic printing characterized by being fine particles.

2. 2. The lithographic printing plate as described in 1 above, wherein the support is a plastic film.

[0015] 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 of the present invention lies in the hydrophobizing precursor. First, the hydrophobizing precursor of the present invention has a hydrophilic graft chain on its surface. Secondly, the effect of the present invention is expressed by the fact that the particles are hydrophobic or heat-reactive polymer fine particles, and secondly, that the hydrophobizing precursor carries light-heat converting metal fine particles.

The hydrophilic graft chain is a graft group in which the terminal of the hydrophilic polymer chain is bonded to the surface of the polymer fine particles (hydrophobizing precursor), and the hydrophobic chain is image-recorded by the graft chain. The layer is firmly bonded to the hydrophilic medium (binder) to 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 strongly 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.

The hydrophobizing precursor carries fine particles of photothermal conversion metal, which effectively absorbs the imagewise irradiation light, converts it into heat energy, and transfers heat efficiently to the fine polymer particles. Therefore, heat fusion of polymer fine particles (hereinafter,
Hydrophobicization such as thermal softening, thermal melting, and hydrophobicization by forming a crosslinked structure is collectively referred to as thermal fusion or thermal fusion.) In addition, the metal fine particles themselves also cover the irradiated area by heat fusion, and the effect of hydrophobicity is further enhanced, contributing to the improvement of discrimination. Since the melting point is lower than the melting point of the constituent metal elements due to the size effect due to the small size of the metal fine particles, laser light drawing is not strong enough to cause ablation even in high illuminance and short time Thus, a hydrophobic region can be formed by heat fusion together with polymer fine particles.

In the printing original plate of the present invention, since the image recording layer is in direct contact with the fine metal particles and the hydrophobizing precursor, the heat use efficiency, that is, the sensitivity is high, and the heat-treated portion is not used. The heat-fused product of the hydrophobizing precursor forms an imagewise hydrophobic region, and realizes print quality with excellent discrimination. In addition, since the polarity is changed only by the application of heat and the ink becomes receptive and a printed screen is formed, the plate making process is simple and does not require a developing process. Furthermore, since the hydrophilic graft chains firmly fix the hydrophobic precursor particles in the non-image area and the hot-melt region in the image area to the medium of the hydrophilic binder, printing durability is also improved, An original printing plate satisfying the object of the present invention is realized.

[0019]

Embodiments of the present invention will be described below in detail. [Image Recording Layer] 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 is a hydrophilic layer containing the hydrophobizing precursor 6 in a dispersed state in a hydrophilic binder. The hydrophobizing precursor 6 absorbs light and converts light energy into heat energy. It is composed of polymer fine particles that carry the metal fine particles 5 to be converted and have hydrophilic graft chains 8 on the surface.
The hydrophilic graft chains 8 of the polymer fine particles of the hydrophobizing precursor 6 firmly bind the hydrophobizing precursor to the hydrophilic medium, thereby enhancing the film strength of the image recording layer. In addition,
In FIG. 1, it is a typical embodiment of the present invention to provide a heat insulating layer 3 for preventing heat energy from escaping and to include a photothermal conversion agent for generating more heat energy in the image recording layer 4. It is not essential for the invention.

The printing plate 11 shown on the right side of FIG. 1 is formed by irradiating a laser beam 7 shown by an arrow above the original plate 1 on the left side with metal fine particles 5 as a photothermal conversion agent and a hydrophobizing precursor carrying the same. 6 shows that the heat-fused layer 6 is heat-fused to form a heat-fused layer 15, forming a hydrophobic area on the surface of the irradiated area of the image recording layer. The heat-sealing layer 15 is formed by the hydrophilic graft chains 8 contained in the original polymer fine particles of the hydrophobizing precursor 6.
To form a strong image area in the hydrophilic medium.

FIG. 2 is a view showing a particularly preferred embodiment of a printing method using the printing original plate of the present invention. In FIG. 2, the printing plate 1 shown in the left figure and the printing plate 11 shown in the right figure.
Are the same as the contents described in FIG. The lower figure shows the printing plate 21 on a printing press. In this embodiment,
During printing, the image recording layer in the non-image area is removed using a dampening solution and / or ink, so that the hydrophilic support (aluminum substrate) (in the case of FIG. 2) in the non-image area forms an ink repellent area. are doing. Therefore, ink stains are less likely to occur,
Improves discrimination.

The image-recording layer according to the present invention contains a hydrophilic resin as a binder and a hydrophobizing precursor composed of polymer fine particles having a hydrophilic graft chain as essential components. As a further preferred embodiment, in addition to the metal fine particles described above, a light-to-heat conversion agent that is not supported on the hydrophobic precursor may be contained. It may be added or included in the hydrophobizing precursor, and is not necessarily an essential component of the image recording layer. However, photothermal conversion agents are also described in this section. The film strength of the image recording layer itself is improved because the hydrophobized precursor itself or its heat-melted hydrophobic region is surrounded by hydrophilic graft chains and is stably retained in the hydrophilic resin as a binder. As a result, the printing durability also increases. Also,
The on-press developability is also improved, which leads to an improvement in stain resistance.
Hereinafter, the components of the image recording layer will be sequentially described.

(Hydrophobic Precursor Having Hydrophilic Graft Chain According to the Present Invention) The polymer fine particles into which the hydrophilic graft chain according to the present invention has been 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, The Society of Polymer Publishing, and “New Polymer Experiment 2, Polymer Synthesis and Reaction” edited by the Society of Polymer Science , Kyoritsu Publishing 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). Of 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 viewpoints of production suitability and control of the film structure.

The synthesis and microparticulation of the graft polymer using the macromer are described in "New Polymer Experimental Science 2, Synthesis and Reaction of Polymer", edited by The Society of Polymer Science, Kyoritsu Shuppan Co., Ltd., 199.
5. "Yamashita Yuu et al., Macromonomer Chemistry and Industry", IPC 1989, Naoya Ogata et al.
98.

Specifically, (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 its mineral acid salt, carboxyl group or its salt, sulfonic acid group or its salt, phosphoric acid or its salt, 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, and acrylates such as methoxyethyl acrylate, methoxypolyethylene glycol acrylate, and polyethylene glycol acrylate. 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, the preferred range is 1000 to 50,000, and the preferred range is 1500 to 20,000.
If the molecular weight is less than 400, self-dispersing polymer fine particles cannot be formed. After synthesizing these hydrophilic macromers, one method of preparing the polymer microparticles having the hydrophilic graft chains of the present invention introduced therein is to homopolymerize the above-mentioned hydrophilic macromer in an aqueous solvent, or to be the core of the polymer microparticles. It can be obtained by copolymerization with other monomers. 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.

The hydrophobic and heat-fusible polymer fine particles constituting the core portion of the hydrophobizing precursor having a hydrophilic graft chain according to the present invention include thermoplastic polymer fine particles, thermosetting polymer fine particles, and heat-reactive polymer fine particles. It is selected from polymer fine particles having a functional group.

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
Nos. 850, 9-171249, 9-17
Suitable examples include thermoplastic fine particle polymers described in 1250 and EP931647. Specific examples include ethylene, styrene,
Examples include homopolymers or copolymers of monomers such as vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, and the like, 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), 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 evaporate the organic solvent. There is a method of removing and 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 during the polymerization, it is preferable to carry out emulsion polymerization or suspension polymerization of the monomer 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 above fine particle polymer is 0.1.
01 to 20 μm is preferable, and among them, 0.05 to 1 μm is preferable.
0 μm is more preferable, and particularly preferably 0.1 to 5.0 μm. Within this range, good resolution and stability over time can be obtained. The amount of the fine particle polymer having a reactive functional group to be added is preferably 10% by weight or more, more preferably 20% by weight or more of the solid content of the image recording layer.

(Metal fine particles) Metal fine particles are used as the photothermal conversion agent carried on the surface of the hydrophobizing precursor contained in the image recording layer having a hydrophilic surface. In order to exhibit the effects of the present invention, it is necessary that the metal fine particles as the photothermal conversion agent have a sufficient light absorbing ability to cause the above-mentioned thermal melting. The necessary light absorption capability is to have a spectral absorption region having a transmission density of 0.3 or more in the spectral wavelength region of the irradiation light. In the above description, the spectral wavelength region having a transmission density of 0.3 or more is, specifically, when the irradiation light is a single-wavelength light, a wavelength region of 100 nm width around the wavelength,
In the case of continuous spectrum light, any continuous 100n
It means a wavelength range of m width. In this case, the transmission density of the image recording layer is a value measured according to international standards ISO5-3 and ISO5-4.

Preparation of Metal Fine Particles and Preparation of Polymer Fine Particles
The loading method will be described. Conventionally, a method of preparing metal fine particles using a water-soluble polymer such as polyvinyl alcohol as a dispersant has been known.However, the present invention uses a hydrophilic graft chain of polymer fine particles having a hydrophilic graft chain on the surface as a dispersant. This is a method for preparing metal fine particles, and by such a preparation method, metal fine particles can be supported on the surface of polymer fine particles. As a method of supporting metal fine particles on the surface of polymer fine particles having a hydrophilic graft chain on the surface, a metal salt is added to a dispersion of the fine particles,
For example, a method using a mild reducing agent such as alcohol, or a method using a reducing action of a radical initiator by adding a metal salt when synthesizing the polymer fine particles by radical polymerization, etc. No.

As the metal fine particles that can be used for the metal fine particles of the present invention, any metal fine particles can be used as long as they contribute to forming a hydrophobic region near the hydrophobizing precursor by light irradiation. However, preferable fine metal particles are fine particles of a metal selected from the group 8 of the periodic table, the group 1B, the group 3, the group 4, the group 5A, and the group 6A, and the d-shell and f-shell transition metals. The metal to be formed is a simple substance or an alloy selected from Group 8 and Group 1B, and among them, fine particles of a simple substance or an alloy of Ag, Au, Cu, Pt, and Pd. It is also preferable that the material has photothermal conversion properties.

The average diameter of the fine metal particles used in the present invention is 1 to 500 nm, preferably 2 to 300 nm.
m, particularly preferably 3 to 100 nm, which corresponds to a so-called ultrafine particle size region. If the size is larger than 500 nm, the sensitivity of hydrophobization (thermosensitivity or heat mode photosensitivity) decreases, so that large heat or light energy is required. Although the particle size distribution may be wide or narrow, it is preferable that the particle size distribution is narrow, that is, so-called monodisperse particles, because the change to hydrophobicity becomes clear. The monodisperse particles in the present invention have a coefficient of variation of preferably 30% or less, more preferably 25% or less, and most preferably 20% or less.

The salt form of the metal element of the metal salt capable of forming fine metal particles may be any salt form as long as it is water-soluble, and may be a nitrate, a sulfate, a halide, a thiocyanate, a sulfite, an acetate. Selected from inorganic salts such as carboxylate represented by acetic acid, lactate and benzoate; ammine complex salts such as silver ammonium complex nitrate and copper ammonium complex nitrate; and polyhalo complex salts of silver and gold such as polychlorosilver complex ion. It is.

The amount of the metal salt is 0.001 to 5 mol, preferably 0.005 to 1 mol, per 100 g of the polymer fine particles or its raw material monomer, and the optimum ratio varies depending on the type of the metal fine particles.

When reducing metal salts with a mild reducing agent to form fine metal particles, preferred reducing agents are alcohols, saccharides and carbohydrates, cellulose derivatives and aldehydes. Organic compounds in these categories are originally considered to have a low reducibility, but in an alkaline environment, the reductivity has a reducing power to sufficiently reduce the reducible metal salt described above. By adding an alkali agent such as caustic alkali or alkali carbonate and appropriately selecting the pH range, it is possible to obtain colloidal metal fine particles which are easily melted by heat. Preferred specific compounds include the following. That is, methanol,
Aliphatic alcohols such as ethanol, propanol and diethylene glycol; ribose, arabinose, xylose, glucose, mannose, growth, galactose, sorbose, fructose, sorbitol, mannitol and other monosaccharides and hexasaccharides; maltose, lactose, dextran, inulin, Polysaccharides such as amylose, sucrose, dextrin, and soluble starch; methylcellulose,
Cellulose derivatives such as carboxymethylcellulose, carboxyethylcellulose and hydroxymethylcellulose; aliphatic saturated aldehydes such as formaldehyde, glutaraldehyde, acetaldehyde, propionaldehyde and butyraldehyde; aliphatic dialdehydes such as glyoxal and succindialdehyde; acrolein and crotonaldehyde And unsaturated aldehydes such as propioaldehyde; aromatic aldehydes such as benzaldehyde, saltyl aldehyde, and naphthaldehyde; heterocyclic aldehydes such as furfural, glyceraldehyde, and dihydroxyacetone (including dimers). .

Of these exemplified compounds, particularly preferred are methanol, ethanol, glucose, sorbose, glycerin, amylose, sucrose, dextrin, soluble starch, formaldehyde, glutaraldehyde, acetaldehyde, glyoxal, benzaldehyde, saltyl aldehyde, carboxymethyl cellulose, and carboxymethyl cellulose. And hydroxymethyl cellulose.

The pH of the aqueous solution of the reaction system in the case of generating fine metal particles with these reducing organic compounds varies depending on the type of the organic compound, but is usually preferably 7 or more. Between. However, for sugars and cellulose derivatives, higher pH
The area is preferably 10 or more, particularly preferably 12 or more. The upper limit is a region where the pH value has no substantial meaning, that is, 14 (for example, the concentration of caustic is 5%).
May be.

The amount of the reducing organic compound to be added to the aqueous solution of the reaction system is not particularly limited as long as the saccharide is stoichiometrically larger than the metal salt. It is convenient to use 1.0 to 10 equivalents, preferably 1.01 to 5 equivalents, but the optimum range varies depending on the type of the metal compound and the reducing organic compound.

The concentration of the metal salt in the aqueous solution is 0.0001
-10 mol / L, preferably 0.0005-5 mol / L
L, more preferably at a concentration of 0.001 to 5 mol / L. The amount of the metal compound is determined so as to satisfy the above-mentioned quantitative ratio relationship with the polymer constituting the polymer fine particles.

(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, for example, a polymer compound having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl, and carboxymethyl is 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, hydroxyethyl methacrylate homopolymers and copolymers, hydroxyethyl acrylate homopolymers and copolymers, hydroxypropyl methacrylate homopolymers and copolymers, hydroxypropyl acrylate homopolymers 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 a bonding group coming out of a 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 when there are many alkoxy groups and hydroxyl groups, and the network-like resin structure becomes strong as dehydration condensation 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.
Hereinafter, a sol-gel conversion system using silicon will be described. However, a sol-gel conversion system using aluminum, titanium, and zirconium can be implemented by replacing silicon 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, whereby 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 crosslinking 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 the 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. There may be a mixture of

[0056]

Embedded image

The siloxane resin of the general formula (I) is formed by 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.),

-OCOR "group (R" represents the same contents as R '), -COOR "group, -COR" group, -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, etc.).

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 number 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, tetra-n-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.

The image recording layer according to the present invention has the general formula (II)
Ti, Zn, Sn, Zr, Al
In the case of sol-gel conversion, a metal compound capable of forming a film by binding to a resin can be used in combination. As the metal compound used, for example, Ti (OR '') ₄ , TiCl ₄ , Zn (OR '') ₂ , Zn (C
H ₃ COCHCOCH ₃ ) ₂ , Sn (OR '') ₄ , Sn (CH ₃ COCHCOCH ₃ ) ₄ , Sn (OC
OR '') 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 acidic 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, if a highly concentrated basic catalyst is used, a precipitate may be formed in the sol solution. Therefore, the concentration of the basic catalyst is desirably 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, benzenesulfonic acid and the like. 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 further details on the above-mentioned sol-gel method, see "Sol-gel method science" by Agio Shofusha Co., Ltd. (1988) by Sakuhana Sakuhana, and "Functional thin film production technology by the latest sol-gel method" by Shu Hirashima, published by the Sogo Gijutsu Center. (1992
Year).

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

(Light-to-heat conversion agent) In the present invention, since the image recording layer carries metal fine particles as a light-to-heat conversion agent on polymer fine particles having a hydrophilic graft group, it is necessary to further include a light-to-heat conversion agent. No, but may be added. It is preferable to include a photothermal conversion agent in the image recording layer, because the utilization efficiency of the light absorbed by the metal fine particles as heat energy is generally increased. The photothermal conversion agent not supported by the polymer particles used for this purpose is 700
A substance that absorbs light of nm or more is particularly preferable, and various pigments and dyes can be used.

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 pigment surface are conceivable. 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. As such a pigment that absorbs infrared rays, carbon black is preferable,
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
744, etc .; squarylium dyes described in JP-A-58-112792; cyanine dyes described in British Patent 434,875; and dyes described in U.S. Pat. No. 4,756,993. And cyanine dyes described in U.S. Pat. No. 4,973,572, dyes described in JP-A-10-268512, JP-A-11-23.
No. 5,883, phthalocyanine compounds.

As another preferred dye, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also suitably used, and a substituted dye described in US Pat. No. 3,881,924 is preferably used. Arylbenzo (thio) pyrylium salts, trimethinethiapyrylium salts described in JP-A-57-142645, JP-A-58-181051, 58-220
No. 143, No. 59-41363, No. 59-84248
No. 59-84249, No. 59-146063,
Pyrylium compounds described in JP-A-59-146061, cyanine dyes described in JP-A-59-216146, pentamethine thiopyrylium salts described in U.S. Pat. No. 4,283,475, etc. Nos. 13514, 5-19702, Epolite III-178 and Epolite I manufactured by Eporin Co.
II-130, 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.

[0077]

Embedded image

[0078]

Embedded image

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 simultaneously emulsifying these lipophilic photothermal conversion agents at the stage of forming the fine particles such as emulsion polymerization or dispersion polymerization.

[0080]

Embedded image

[0081]

Embedded image

As a specific example of the near-infrared absorbing agent when an infrared laser is used, a dye is exemplified. Preferred dyes are dyes and pigments that have the property of absorbing infrared radiation and converting it to thermal 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 cysteine 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. Among them, phthalocyanine green, phthalocyanine blue and other phthalocyanine complex salts of copper, cobalt, nickel and iron, 3,3′-ethylmesoethylnaphthia (oxa) dicarbocyanine, 3,3′-ethylnaphthia (oxa) tricarbocyanine and the like. Representative dicarbocyanine and tricarbocyanine dyes are preferred.

When a photothermal conversion agent is added to the image recording layer in addition to the metal fine particles supported on the hydrophobizing precursor, the addition amount should be up to 20% by weight of the total solids of the image recording layer. Can be. It is preferably from 0.2 to 15% by weight, particularly preferably from 0.5 to 10% by weight.

(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) and the like.
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 weight 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 in order 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 weight based on the weight of the whole composition. Also, 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 weight 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, for imparting flexibility of the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate,
Dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, and the like are used.

Further, inorganic fine particles may be added to the image recording layer of the present invention, and preferable 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 1.0 to 70% by weight, more preferably 5.0 to 50% by weight 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 support, and the exposure latitude can be advantageously increased. The heat insulating layer provided as a lower layer of the image recording layer is a layer having a low thermal conductivity and 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.

Such a 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 hydrophobic resin, a resin composed of an aqueous emulsion may 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, aggrilonitrile-butadiene-based, chloroprene-based, etc.), and polyurethane resin.

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 vinyl-crotonic acid copolymer and styrene-maleic acid copolymer.

Further, the above 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,
A methylol compound such as a methylolated polyamide resin,
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 that can be preferably applied to the present invention includes:
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. It is a molecular body and is in a sol state when there are many alkoxy groups and hydroxyl groups, and the network-like resin structure becomes strong as dehydration condensation proceeds. Further, in addition to the property of changing the degree of hydrophilicity of the resin structure, 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, thereby 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 from 2 to 95% by mass of the solid components. 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, improvement of the physical strength of the heat insulating layer, improvement of the dispersibility of the components constituting the layer, improvement of the coating property, and improvement of the hydrophilic layer 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.

[Undercoat Layer] In the present invention, before coating the thermosensitive layer, an inorganic undercoat layer such as a water-soluble metal salt such as zinc borate or an organic undercoat layer may be provided if necessary. You may be. Examples of the organic compound used in the organic undercoat layer include carboxymethyl cellulose, dextrin, gum arabic, polymers and copolymers having a sulfonic acid group in a side chain, polyacrylic acid, and amino acids such as 2-aminoethylphosphonic acid. Phosphonic acids having a group, phenylphosphonic acid which may have a substituent, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, organic phosphonic acids such as methylenediphosphonic acid and ethylenediphosphonic acid, having a substituent Organic phosphoric acids such as phenylphosphoric acid, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid, and organic phosphinic acids such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent , Amino acids such as glycine and β-alanine, and Amine hydrochloride having a hydroxyl group of the hydrochloride salt of the fine triethanolamine, although selected from yellow dyes, it may be used by mixing two or more. The undercoat layer may contain the photothermal conversion agent.

This organic undercoat layer can be provided by the following method. That is, a solution in which the above organic compound is dissolved in water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is applied to an aluminum plate and dried. A solution of the above organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used. The coating amount of the organic undercoat layer after drying is 2 to 200 mg /
m ² is preferred, and more preferably 5 to 100 mg / m ² .

[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 in order to ensure uniformity of application. . Dry coating amount of the overcoat layer, 0.1 to 2.0 g / m ² is preferred. Within this range, excellent contamination of the surface of the image recording layer with a lipophilic substance such as fingerprint adhesion can be prevented without impairing the on-press developability.

[Coating] The above-mentioned 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. Coating and drying 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 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 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 weight 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 a surfactant, an organic solvent, an alkaline aqueous solution or the like 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. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. As a chemical method, Japanese Patent Application Laid-Open No.
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. As an electrochemical surface roughening method, there is a method in which an alternating current or a direct current is used 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 preferable 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 wt% 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 preferred 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 anodic oxidation treatments, particularly, a method of anodic oxidation at 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 (1) 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, which is bonded to the support surface by an ether bond, and the R ′ group is hydrophobic. Provides a surface.

Examples of silane coupling agents include γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycoxydoxysilane. There may be mentioned, for example, propyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptotrimethoxysilane, γ-ureidopropyltriethoxysilane, N- (β-aminoethyl)-(β-aminopropyl) dimethoxysilane. In order to ensure the adhesion to the image recording layer, the plastic support may be subjected to a charging treatment by a known method before coating. When a plastic support is used as the support used in the present invention, a hydrophilic layer may be applied to make the surface hydrophilic. The hydrophilic layer contains a colloid of an oxide or hydroxide of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. A hydrophilic layer formed by applying a coating solution is preferred. Among them, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or hydroxide colloid is preferable.

[Plate Making and Printing] Next, a plate making method of the lithographic printing plate precursor will be described. As the lithographic printing plate precursor, a solid-state laser or semiconductor laser that emits infrared light having a wavelength of 760 to 1200 nm, a high-intensity flash light such as a xenon discharge lamp, or a photothermal conversion type exposure such as an 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 case of the former, infrared irradiation method,
In this method, heat is generated by light-heat conversion by irradiating a short time light of high illuminance of a xenon discharge lamp onto the original plate. 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 . If the support is transparent, it can be exposed through the support from the back side of the support. The exposure time is preferably selected so 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 in the range of 0.1 to 10 J / cm ^{2 in} the surface exposure intensity before being modulated with the print image,
More preferably, it is in the range of 0.3 to 1 J / cm ² . If the support is transparent, it can be exposed 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, after mounting on a printing press cylinder, it is also possible to expose by a laser mounted on the printing press, and then apply on a fountain solution or ink to carry out 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.

[0117]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. (Example) Synthesis Example 1 (Ag-loaded polymer fine particles A) 30 g of N-isopropylacrylamide was added to ethanol 7
0 g, 3-mercaptopropionic acid (3.8 g) was added, and the temperature was raised to 60 ° C. in a nitrogen atmosphere.
0 mg was added and reacted at 60 degrees for 6 hours. After completion of the reaction, the precipitated white solid was filtered. Further, after sufficiently washing with methanol, filtration and drying, poly (N-isopropylacrylamide) having a terminal carboxylic acid was obtained.

Next, 80 g of the poly (N-isopropylacrylamide) having a carboxylic acid terminal thus obtained was prepared.
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 reprecipitated with acetone and dried to obtain styryl-terminated poly (N-isopropylacrylamide). Was.

Next, 3 g of the styryl-terminated poly (N-isopropylacrylamide) macromonomer thus obtained and 7 g of styrene were added to 40 g of ethanol and 10 g of water.
And 2 g of initiator 2,2′-azobis [2- (2-imidazolin-2-yl) propane] was added thereto, and reacted at 60 ° C. for 48 hours under a nitrogen atmosphere. Thus, water-dispersible polymer fine particles a in which poly (N-isopropylacrylamide) was grafted on the polystyrene surface were produced. The solid concentration was 11.7% and the particle size was 0.32 μm.

Next, 386.3 g of the polymer fine particles a and 1.7 g of silver nitrate dispersed in the ethanol / water mixture were heated to reflux at 90 ° C. for 3 hours, returned to room temperature, and centrifuged (7000 rpm, 15 minutes). The polymer microparticles A carrying silver microparticles were prepared by sedimenting the polymer microparticles and removing the supernatant, adding water and redispersing. Solid content concentration 12.6%, particle size 0.38 μm
Met.

Synthesis Example 2 (Pt-Supported Polymer Fine Particles B) In place of the silver nitrate used in Synthesis Example 1, 5.2 g of chloroplatinic acid hexahydrate was added, and platinum particles were supported in the same manner as in Synthesis Example 1. Polymer fine particles B were prepared. Solid concentration 1
2.3%, particle size 0.37 μm.

Synthesis Example 3 (Ag-carrying polymer fine particles C) 30 g of 1-vinyl-2-pyrrolidinone was added to ethanol 70
g, 3-mercaptopropionic acid (3.8 g) was added, and the temperature was raised to 60 ° C. in a nitrogen atmosphere.
mg was added and reacted at 60 degrees for 6 hours. After the reaction,
The precipitated white solid was filtered. Further, after sufficiently washing with methanol, filtration and drying, polyvinylpyrrolidone having a terminal carboxylic acid was obtained. 20 g of polyvinylpyrrolidone having a terminal carboxylic acid was dissolved in 62.3 g of DMSO, and 62.4 mg of hydroquinone and glycidyl methacrylate 67 were dissolved.
1 g, and heated to 130 ° C. in a nitrogen atmosphere.
504 mg of dimethyldodecylamine was added and reacted at 130 ° C. for 7 hours. After reprecipitation with acetone, drying was performed to obtain methacryloyl-terminated polyvinylpyrrolidone.

Next, 3 g of the methacryloyl-terminated polyvinyl herolidone macromonomer thus obtained and 4.5 g of methyl methacrylate were dissolved in 100 g of ethanol and 100 g of water, and the initiator 2,2'-azobis [2-
(2-imidazolin-2-yl) propane] 110 mg
Is dissolved in 20 g of water at 75 ° C. in a nitrogen atmosphere at about 2 ° C.
After dropping over time, the reaction was further performed at 75 degrees for 5.5 hours. Thus, water-dispersible polymer fine particles b in which polyvinyl pyrrolidone was grafted on the surface of polymethyl methacrylate were prepared. The solid content of this dispersion is 12.
It was 9% and the average particle size was 0.55 μm.

Next, 350.4 g of polymer fine particles b and 1.7 g of silver nitrate dispersed in the ethanol / water mixture were heated to reflux at 90 ° C. for 3 hours, then returned to room temperature, and centrifuged (7000 rpm, 15 minutes). The polymer fine particles C carrying silver fine particles were prepared by sedimenting the polymer fine particles, removing the supernatant, adding water and redispersing. Solids concentration 12.6%, particle size 0.59μm
Met.

Synthesis Example 4 (Au / Pt-supported polymer fine particle D) Instead of silver nitrate used in Synthesis Example 3, 1.4 chloroauric acid was used.
g and 3.1 g of chloroplatinic acid hexahydrate, and polymer fine particles D carrying gold / platinum fine particles were prepared in the same manner as in Synthesis Example 3. The solid concentration was 11.5% and the particle size was 0.60 μm.

Synthesis Example 5 (Ag carrying polymer fine particles E) Styrene 31.2 g, styryl-terminated poly (N-isopropylacrylamide) macromonomer 50.0 g prepared in Synthesis Example 1, AIBN 1.0 g, silver nitrate 1.0 g were mixed with 150 ml of water. Was dissolved in a mixed solvent of 350 ml of ethanol and reacted at 60 ° C. for 24 hours under a nitrogen stream. Next, the mixture was purified by ultrafiltration to obtain a polymer fine particle dispersion E carrying silver fine particles having a solid content of 12.2% and a particle size of 0.55 μm.

Example 1 <Preparation of aluminum support> In 99.5% by mass of aluminum, 0.01% by mass of copper, 0.03% by mass of titanium, 0.3% by mass of iron, and 0.1% by mass of silicon were used. 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. Furthermore, 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. The electrolytic surface roughening treatment was performed using a current having a rectangular wave alternating waveform under the condition of an anode charge 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 then 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 anodic oxide 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 mass became 3.0 g / m ^2. Then, it was dried in an oven at 80 ° C. for 10 minutes. (Image recording layer coating solution composition) Colloidal silica 20% aqueous solution 200 g Sol-gel preparation liquid 49.5 g Ag-supporting polymer fine particles A 317 g Infrared absorbing dye (1) 5.00 g Water 428.5 g Having the following composition: (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

[0129]

Embedded image

When the contact angle of water droplets on the surface of the obtained printing original plate was measured, it was found that the surface exhibited 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 which was thermally fused was formed on the surface of the exposed portion. 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
A CD was used, 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 without printing stains up to 10,000 sheets.

Examples 2 to 5 In the same manner as in Example 1, lithographic printing original plates were prepared except that polymer fine particles A of Example 1 were changed to polymer fine particles BE. 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 2B 108 ° 10,000 sheets 3C 101 ° 10,000 sheets 4D 99 ° 10,000 sheets 5E 103 ° 10,000 sheets

Example 6 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, an image can be formed with less 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 printing stains and high quality. A printed matter was obtained.

Example 7 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

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

Example 8 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 PET base having a thickness of 180 μm. 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.
No high-quality printed matter was obtained with no print stains on up to 0 sheets.

Example 9 <Coating of Image Recording Layer> An aqueous coating solution having the following composition was prepared, and the dry film mass was 2.0 g / m 2 on a bar coater on the aluminum support prepared in Example 1. ^The coating was performed so as to be ² , and then dried in an oven at 80 ° C. for 10 minutes. (Image recording layer coating liquid composition) Colloidal silica 20% aqueous solution 225 g Sol-gel preparation liquid 49.5 g Ag-loaded polymer fine particles A 317 g Water 408.5 g The same sol-gel preparation liquid as used in Example 1 was used. The lithographic printing plate thus obtained was output at 11 W, an external drum rotation speed of 105 rpm and a plate surface energy of 250 mJ by a Creo Trendsetter 3244 VFS equipped with a water-cooled 40 W infrared semiconductor laser.
/ Cm ² , and exposure at a resolution of 2400 dpi, an image can be formed without adding an IR dye to the image recording layer. A printed matter was obtained.

Example 10 <Coating of Image Recording Layer> An aqueous coating solution having the following composition was prepared, and the weight of the dried film was 1.0 g / m 2 on a aluminum support prepared in Example 1 using a bar coater. Coating was performed so as to be ² , and then dried in an oven at 60 ° C. for 2 minutes. (Composition of image recording layer coating solution) 10% aqueous solution of polyacrylic acid (average molecular weight: 20,000) 100 g Polymer fine particles A 674 g Infrared light absorbing dye (1) 5 g Water 221 g The lithographic plate obtained on the press thus obtained Print version,
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 after exposure
Without processing, Heidelberg printing machine SOR-
After mounting on a cylinder of M and supplying fountain solution, ink was supplied, and further paper was supplied to perform printing. On-press development was possible for all printing plates without any problem, and high-quality printed matter was obtained without printing stains on 20,000 sheets.

Example 11 <Coating of Image Recording Layer> A water-based coating solution having the following composition was prepared, and a dry film having a dry film mass of 1.0 g / m 2 was coated on the aluminum support prepared in Example 1 with a bar coater. Coating was performed so as to be ² , and then dried in an oven at 60 ° C. for 2 minutes. (Image recording layer coating solution composition) Polymer fine particle A 754 g Infrared light absorbing dye (1) 5 g Water 241 g The on-press developable lithographic printing plate thus obtained was
Output 9 W, outer 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 after exposure
Without processing, Heidelberg printing machine SOR-
After mounting on a cylinder of M and supplying fountain solution, ink was supplied, and further paper was supplied to perform printing. This printing plate could be developed on-press without any problem, and high-quality printed matter was obtained without printing stains on 20,000 sheets.

Example 12 A lithographic printing plate capable of on-press development was prepared in the same manner as in Example 11 except that the infrared absorbing dye (1) was removed from the coating solution for the image forming layer used in Example 11, and the plate surface energy was used. 250m
Exposure was carried out in the same manner except that J / cm ² was changed, and printing was performed without processing. This printing plate could be developed on-press without any problem, and high-quality printed matter was obtained without printing stains on 20,000 sheets.

[0144]

According to the present invention, a hydrophilic image recording layer which contains a metal fine particle and contains a hydrophobizing precursor composed of a polymer fine particle having a hydrophilic graft chain on its surface and becomes hydrophobic by heat is provided on a support. The lithographic printing original plate of the present invention, which is provided and on which an image is formed by light irradiation in heat mode, is capable of plate making only by the action of heat without the need for development processing, and is directly mounted on a printing machine to make plate making. In addition to having both the simplicity that printing can be performed and the discriminating property with less printing smear on the printing surface, the film strength of the image recording layer is strong and the printing durability is excellent.

[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.

FIG. 2 is a schematic diagram showing a plate making and printing process using a printing original plate of the present invention in which an image recording layer in a non-image area is removed by a dampening solution or ink.

[Explanation of symbols]

 1. Original plate for lithographic printing 2. Support 3. Heat insulation layer (lower layer) 4. Image recording layer 5. 5. Metal fine particles (light-to-heat conversion agent) 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 in non-image area

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Sumaki Yamazaki 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Fujisha Shin Film Co., Ltd. F-term (reference) 2H025 AA12 AB03 AC08 AD01 BD21 BH03 CC11 CC20 DA18 2H096 AA06 BA01 BA16 EA04 EA23 2H114 AA04 AA14 AA22 AA24 BA01 BA10 DA04 DA55 DA59 DA73 DA75 EA01 EA02 FA16

Claims (2)

[Claims] An image recording layer containing a hydrophobizing precursor which becomes hydrophobic by heat is provided on a support, wherein the hydrophobizing precursor has a hydrophilic graft chain on the surface and a metal An original plate for lithographic printing, characterized by being polymer fine particles carrying fine particles. 2. The lithographic printing plate according to claim 1, wherein the support is a plastic film.