JP2002144693A - Method for lithographic printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for lithographic printing capable of simply obtaining a stable printed product of high quality irrespective of a balance of an image part and a non-image part in lithographic printing using an emulsion ink. SOLUTION: The method for lithographic printing comprises the steps of image recording on a lithographic printing plate original plate having a hydrophilic layer including a crosslinking structure on a support and containing a hydrophobic prepared precursor, and then printing by using the emulsion ink containing an oily ink component, water and/or a hydrophilic component containing a polyhydric alcohol as a main component. Such a lithographic printing plate original plate has the hydrophilic layer which contains the hydrophobic prepared precursor capable of forming a hydrophobic prepared region on a surface by exposure and has a crosslinking structure as a heat sensitive layer. The hydrophilic layer preferably contains at least one type of a hydrophilic resin for forming the crosslinking structure and an inorganic hydrophilic bonding resin formed by a sol-gel transformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing method using a lithographic printing plate. More specifically, the present invention relates to a lithographic printing plate precursor capable of recording an image based on a digital signal and making a plate by a simple process. The present invention relates to a method of printing a lithographic printing plate which can form a stable printed matter by using a lithographic printing plate having an image formed thereon and a non-image portion formed of a hydrophilic layer, without using fountain solution.

[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. Such lithographic printing utilizes the property that water and oil-based ink repel each other, so that a lipophilic image area is an ink receiving area and a hydrophilic non-image area is a dampening water receiving area (an ink non-receiving area). ) Is a method of causing a difference in the adhesiveness of ink on the plate surface, depositing the ink only on the image portion, and then transferring the ink to a printing medium such as paper for printing. PS plates in which a lipophilic photosensitive resin layer is provided on a hydrophilic aluminum support that has been subjected to hydrophilic treatment are widely used. As a plate making method, usually, a lithographic printing original plate is exposed through an original image such as a lith film using a photolithography technique, and then the photosensitive layer is left in an image area, and a non-image area is developed with a developing solution. The aluminum substrate surface is exposed by dissolution and removal, and a dampening water layer is formed on the exposed hydrophilic aluminum substrate surface to prevent ink from adhering. In this method, it was necessary to supply water called a fountain solution or a liquid containing water as a main component from the printing press to the plate surface, but it was difficult to balance the supply amounts of water and ink, and printing was difficult. In such a case, it is necessary to constantly control the amount of dampening water, and in order to control the amount of dampening water properly, not only technology and experience are required, but also a large amount of dampening solution waste liquid is generated. Also, the amount of waste paper at the start of printing was large.

On the other hand, another trend in this field in recent years is that digitization techniques for electronically processing, storing, and outputting image information using a computer have become widespread. Technology,
Various new image output methods have come into practical use. Along with this, a computer / computer for manufacturing a printing plate directly without carrying a lithographic film by carrying digitized image information on highly convergent radiation such as laser light and scanning and exposing the original with this light. Attention has been focused on to-plate technology. Accordingly, obtaining a printing plate precursor suitable for this purpose has become an important technical problem. Therefore, simplification of plate making operation and elimination of dampening solution in the lithographic printing process (drying) are more strongly desired than ever in view of both the above-mentioned environmental aspect and adaptation to digitalization. It has become.

On the other hand, as a simple lithographic printing method using no dampening solution, Japanese Patent Publication No. 54-26923, Japanese Patent Publication No. 57-3060, Japanese Patent Publication No. 56-12862, and Japanese Patent Publication No. 56-23150 No., JP-B-56-3
No. 0856, Japanese Patent Publication No. 60-60051, Japanese Patent Publication No. 61-54220, Japanese Patent Publication No. 61-54222, Japanese Patent Publication No. 61-54223, Japanese Patent Publication No. 61-6
No. 16, JP-B-63-23544, JP-B-2
JP-A-25498, JP-B-3-56622, JP-B4-28098, JP-B5-1934, JP-A-2-63050, JP-A-2-6305
No. 1 is proposed. These use a lithographic printing plate that has a silicone rubber layer as the ink repellent layer in the non-image area, so even without the supply of dampening water during printing, printing can be performed without ink adhering to the non-image area. There is a feature that there is.

Further, Japanese Patent Publication No. 49-26844, Japanese Patent Publication No. 49-27124, and Japanese Patent Publication No. 49-27125
JP, JP-A-53-36307, JP-A-53-36307
No. 36308, JP-B-61-52867, JP-A-58-2114844, JP-A-53-278
03, JP-A-53-29807, JP-A-5-29807
JP-A-4-146110, JP-A-57-212274, JP-A-58-37069, JP-A-54-1
No. 06305 proposes lithographic printing using emulsion ink. These emulsion inks are emulsions of water-containing inks, and since water and ink are separated on the plate surface, water can be supplied from the ink side, and therefore, there is no need to supply dampening water from the printing press. It is a feature. However, when an emulsion ink is applied to a conventional lithographic printing plate having a non-image portion on the surface of an aluminum substrate, there has been a problem that water is lost due to excess water or ground stain is easily caused due to insufficient water. This is because the quantitative balance of ink and water supplied from emulsion ink is constant,
Since the ratio of the non-image portion to which water is supplied and the image portion to which ink is supplied greatly differs depending on the printed matter, it is considered that the width in which the ink and water on the plate surface can be balanced is small.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems when an emulsion ink is applied to lithographic printing. That is, an object of the present invention is to provide a lithographic printing method capable of easily obtaining a stable and high-quality printed matter in lithographic printing to which an emulsion ink is applied, regardless of the balance of an image portion / non-image portion. It is in.

[0007]

As a result of the study, the present inventor has found that the above problem can be solved by using a heat-sensitive layer having a hydrophobized precursor which forms a hydrophobic region upon exposure. Was completed. That is, the lithographic printing method of the present invention comprises, on a support, a lithographic printing plate precursor containing a hydrophobic precursor and having a hydrophilic layer having a crosslinked structure, after performing image recording, and then using an oil-based ink component. Printing is performed using an emulsion ink containing water and / or a hydrophilic component containing a polyhydric alcohol as a main component.

Although the function of the present invention is not clear, in the present invention, a lithographic printing plate precursor having a hydrophilic layer containing a hydrophobizing precursor as a heat-sensitive layer is used. Shows the same hydrophilicity as the surface of the aluminum support that forms the hydrophilic region of the lithographic printing plate precursor, but partially exposes the hydrophobic surface of the hydrophobizing precursor due to abrasion during printing and partially becomes hydrophilic. May drop. Even in such a case, the affinity with the hydrophilic component having a polarity lower than that of water contained in the emulsion ink is exerted, and the hydrophilic component in the emulsion ink covers the entire surface regardless of the area of the hydrophilic region. It is presumed that a uniform film can be easily formed and held, and that the ink deposition on the non-image area can be effectively prevented for a long period of time, so that a stable, high-quality printed matter can be easily obtained. .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, the emulsion ink used in the lithographic printing method of the present invention will be described.

[Emulsion ink] The emulsion ink used in the present invention is an emulsion ink obtained by adding a hydrophilic component to an oil-based ink component and emulsifying it.
ter in oil), but O / W (oil in wate)
r) It may be a type. Further, the emulsion ink used in the present invention keeps a stable emulsified state in an ink fountain of a printing press when applied to printing in a storage state in an ink can and receives a shearing force (shear) during printing. At the time when the inking system is transferred to the inking roller, the emulsification is broken and the hydrophilic component is separated and supplied onto the plate surface. On the plate surface, the hydrophilic component adheres to the non-image area to form a liquid film and prevents the oil-based ink component from adhering, while the oil-based ink component adheres to the image area. Any emulsion ink having such a function can be used in the present invention without any particular limitation. Further, in order for the emulsion ink of the present invention to exhibit the above function, it is more preferable to use a printing machine equipped with a cooling mechanism in the inking system.

The proportion of the oily ink component and the hydrophilic component in the emulsion ink of the present invention is 5 to 150 parts by weight, preferably 10 to 120 parts by weight, based on 100 parts by weight of the oily ink component. Preferably, 20 to
100 parts by weight. As the oily ink component of the emulsion ink of the present invention, vegetable oil, synthetic resin varnish or natural resin varnish, or a synthetic varnish thereof,
An ordinary oil-based ink comprising a high-boiling petroleum solvent, a pigment, and other additives (such as a friction resistance improver, an ink dryer, and a drying inhibitor) can be used. As the hydrophilic component of the emulsion ink of the present invention, water and / or polyhydric alcohols can be used. Examples of polyhydric alcohols include glycerin, diglycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, sorbitol, butanediol, pentanediol, and the like. Among them, glycerin, ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol can be preferably used. The polyhydric alcohol may be used alone, or two or more kinds may be used as a mixture, and may be used as a mixture with water. The preferred content of the polyhydric alcohol in the hydrophilic component of the present invention is 30 to 100% by weight, more preferably 50 to 100% by weight. As the hydrophilic component of the present invention, in addition to the above, it is possible to use a hydrophilic additive for the purpose of improving emulsion stability, improving flow characteristics, improving hydrophilicity, suppressing evaporation of the hydrophilic component, and the like. it can. For example, monohydric alcohols such as methanol and ethanol,
Monoethanolamine, amino alcohols such as diethanolamine, nonionic, anionic, cationic,
Betaine-based known surfactants, glycolic acid, lactic acid,
Oxycarboxylic acids such as citric acid, polyvinylpyrrolidone, polyacrylic acid, gum arabic, hydrophilic polymers such as carboxymethyl cellulose, phosphoric acid, silicic acid, nitric acid, and inorganic acids and salts such as salts thereof. Can be

[Lithographic printing plate precursor] Next, the configuration of the lithographic printing plate precursor to which the method of the present invention is applied will be described. The lithographic printing plate precursor to which the lithographic printing method of the present invention is applied contains a hydrophilic layer having a crosslinked structure as a heat-sensitive layer, containing a hydrophobic precursor capable of forming a hydrophobic region on the surface by exposure. The heat-sensitive layer consists of a hydrophilic layer with a cross-linked structure and excellent mechanical strength, and the hydrophobic precursors dispersed in the hydrophilic layer are fused together by heat during image recording to form a hydrophobic area. I do.

[Thermal Sensitive Layer] The thermosensitive layer (image recording layer) of the lithographic printing plate precursor to which the method of the present invention is applied will be described.
The heat-sensitive layer is made of at least one component selected from thermoplastic polymer fine particles, thermosetting polymer fine particles, polymer fine particles having a thermoreactive functional group, and microcapsules containing a compound having a thermoreactive functional group. As a chemical precursor.

(Hydrophobic Precursor) As a thermoplastic fine particle polymer suitable for the present invention, Research Did.
sclosure No. 33303, JP-A Nos. 9-12387, 9-131850, 9-171249, 9-171250, and EP93164.
Preferred examples include the thermoplastic fine particle polymer described in JP-A No. 7-No. Specific examples include homopolymers or copolymers of monomers such as ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, and vinyl carbazole, or mixtures thereof. Can be. Among them, polystyrene and polymethyl methacrylate are more preferable.

The thermosetting resin suitable for the present invention includes a resin having a phenol skeleton, a urea-based resin (for example, a resin obtained by converting a urea derivative such as urea or methoxymethylated urea into a resin with an aldehyde such as formaldehyde), or melamine. Examples include a system resin (for example, melamine or a derivative thereof formed into a resin with an aldehyde such as formaldehyde), an alkyd resin, an unsaturated polyester resin, a polyurethane resin, and an epoxy resin.

Examples of suitable resins having a phenol skeleton include phenol resins obtained by resinifying phenol or cresol with an aldehyde 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.

The fine particles containing a thermosetting compound used in the present invention preferably have an average particle size of 0.01 μm to 2.0 μm. 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 dispersing agent, and further heated to form fine particles while removing the organic solvent. There is a method of solidifying.
Further, when the thermosetting resin is synthesized, fine particles may be formed. However, it is not limited to these methods.

The heat-reactive functional group of the polymer fine particles having a heat-reactive functional group and the microcapsule containing the compound having a heat-reactive functional group used in the present invention may be an ethylenically unsaturated group which undergoes a polymerization reaction (for example, , An acryloyl group, a methacryloyl group, a vinyl group, an allyl group, etc.), an isocyanate group which performs an addition reaction or a block thereof, and a functional group having an active hydrogen atom as a reaction partner thereof (for example, an amino group, a hydroxyl group, a carboxyl group) Etc.), an epoxy group and an amino group, a carboxyl group or a hydroxyl group which are the same as those of the addition reaction, a carboxyl group and a hydroxyl group or an amino group which perform a condensation reaction, and an acid anhydride and an amino group which perform a ring-opening addition reaction. Or a hydroxyl group etc. can be mentioned. 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 heat-reactive functional group used in the heat-sensitive layer of the present invention includes acryloyl group, methacryloyl group, vinyl group, allyl group, epoxy group, amino group, hydroxyl group, carboxyl group, isocyanate group, and the like. Acid anhydrides and those having a group protecting them can be mentioned. The introduction of these functional groups into the polymer particles may be performed at the time of polymerization, or may be performed using a polymer reaction after polymerization.

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.

Among the above-mentioned fine particle polymers having a thermoreactive functional group, those in which the fine particle polymers unite by heat are preferable, and those whose surface is hydrophilic and which disperses in water are particularly preferable. The contact angle (water droplets in the air) of the film produced by applying only the fine particle polymer and drying at a temperature lower than the coagulation temperature is lower than the contact angle of the film produced by drying at a temperature higher than the coagulation temperature ( (Water droplets in the air). In order to make the surface of the fine particle polymer hydrophilic, a hydrophilic polymer or oligomer such as polyvinyl alcohol and polyethylene glycol, or a hydrophilic low-molecular compound may be adsorbed on the surface of the fine particle polymer. However, the present invention is not limited to this. By using such hydrophobic fine particles whose surface is hydrophilized, if they are dispersed in the hydrophilic resin of the matrix, even if they are partially exposed on the surface of the hydrophilic layer,
Since the surface of the fine particles is completely hydrophilized, an advanced non-image portion of the hydrophilic layer in which the generation of stains due to the adhesion of ink during printing is suppressed is achieved. Furthermore, by using the fine particles having excellent water dispersibility by making the surface hydrophilic, the fine particles are easily and uniformly dispersed in the aqueous coating solution during the formation of the hydrophilic layer, and have an advantage that the suitability for production is improved. .

The solidification 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 view of the stability over time. The average particle size of the fine particle polymer is preferably 0.01 to 20 μm, more preferably 0.05 to 2.0 μm, and most preferably 0.1 to 1.0 μm. Within this range, good resolution and stability over time can be obtained. The addition amount of the fine particle polymer having these reactive functional groups,
20% by weight or more of the solid content of the heat-sensitive layer is preferable, and 40% by weight
The above is more preferred.

The microcapsules used in the present invention are:
It contains a compound having a thermoreactive functional group. Compounds having this heat-reactive functional group include polymerizable unsaturated groups, hydroxyl groups, carboxyl groups or carboxylate groups or acid anhydrides, amino groups, epoxy groups,
And a compound having at least one functional group selected from an isocyanate group or a block thereof.

As the compound having a polymerizable unsaturated group,
At least one ethylenically unsaturated bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group;
And preferably two or more compounds. Such a compound group is widely known in the industrial field, and in the present invention, these can be used without particular limitation. These are, in chemical form, monomers, prepolymers, ie dimers, trimers and oligomers, or mixtures or copolymers thereof.

Examples include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids and fatty acids. Esters with aliphatic polyhydric alcohols and amides of unsaturated carboxylic acids with aliphatic polyhydric amines. Also,
An addition reaction product of an unsaturated carboxylic acid ester or unsaturated carboxylic acid amide having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group with a monofunctional or polyfunctional isocyanate or an epoxide; A dehydration-condensation reaction product with a functional carboxylic acid is also preferably used. Further, an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group, and a monofunctional or polyfunctional alcohol,
Addition reactants with amines and thiols, and also substituted reactants with unsaturated carboxylic esters or amides having a leaving group such as a halogen group or a tosyloxy group, and monofunctional or polyfunctional alcohols, amines and thiols. It is suitable. Another preferred example is a compound in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid or chloromethylstyrene.

Specific examples of the polymerizable compound which is an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate,
3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane tris (acryloyloxypropyl) ether, trimethylolethane Triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate,
Pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate,
Examples thereof include sorbitol pentaacrylate, sorbitol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, and polyester acrylate oligomer.

Examples of methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloyloxy-2 Hydroxypropoxy) phenyl]
Examples thereof include dimethylmethane and bis- [p- (methacryloyloxyethoxy) phenyl] dimethylmethane.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
Examples thereof include 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, and sorbitol tetritaconate.

As the crotonic acid ester, ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like can be mentioned. Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Maleic esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate,
Sorbitol tetramalate and the like can be mentioned.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, and JP-A-59-5240. JP-A-59-5
241 and JP-A-2-226149, and those having an amino group described in JP-A-1-165613.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples thereof include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, and xylylenebismethacrylamide. Examples of other preferred amide-based monomers include those having a cyclohexylene structure described in JP-B-54-21726.

A urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group is also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups per molecule and an unsaturated monomer having a hydroxyl group represented by the following formula (I) added to one molecule. Urethane compounds containing at least two polymerizable unsaturated groups are exemplified.

Formula (I) CH ₂ ＣC (R ¹ ) COOCH ₂ CH (R ² ) OH (where R ¹ and R ² represent H or CH ₃ )

Further, urethane acrylates described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765 and JP-B-58-4
9860, JP-B-56-17654, JP-B-62-
Urethane compounds having an ethylene oxide skeleton described in JP-A-39417 and JP-B-62-39418 are also preferable.

Further, radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909, and JP-A-1-105238 are preferable. It can be mentioned as.

Other preferred examples include polyester acrylates and epoxy resins described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. Examples thereof include polyfunctional acrylates and methacrylates such as epoxy acrylates obtained by reacting a resin with (meth) acrylic acid. In addition, JP-B-46-43946,
Specific unsaturated compounds described in JP-B-1-40337 and JP-A-1-40336, and vinylphosphonic acid-based compounds described in JP-A-2-25493 can also be mentioned as preferable ones. In some cases, compounds containing a perfluoroalkyl group described in JP-A-61-22048 are also preferably used. In addition, Journal of the Adhesion Society of Japan, Vol. 20, No. 7, pages 300-308 (198
Those introduced as photocurable monomers and oligomers in (4 years) can also be suitably used.

Preferred epoxy compounds include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene diglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, bisphenols and polyphenols or hydrogenated products thereof. And polyglycidyl ether.

Suitable isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, cyclohexane phenylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, cyclohexyl diisocyanate, or alcohols such as alcohols. Alternatively, a compound blocked with an amine can be mentioned.

Suitable amine compounds include ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, propylenediamine, polyethyleneimine and the like.

Suitable compounds having a hydroxyl group include compounds having a terminal methylol group, polyhydric alcohols such as pentaerythritol, and bisphenols and polyphenols. Preferred compounds having a carboxyl group include pyromellitic acid,
Examples include aromatic polycarboxylic acids such as trimellitic acid and phthalic acid, and aliphatic polycarboxylic acids such as adipic acid. Suitable acid anhydrides include pyromellitic anhydride, benzophenonetetracarboxylic anhydride and the like.

Preferred copolymers of the ethylenically unsaturated compound include allyl methacrylate copolymers. For example, an allyl methacrylate / methacrylic acid copolymer, an allyl methacrylate / ethyl methacrylate copolymer, an allyl methacrylate / butyl methacrylate copolymer, and the like can be given.

As a method for microencapsulation, a known method can be applied. For example, as a method for producing microcapsules, US Pat.
No. 458, U.S. Pat. No. 3,287,154, U.S. Pat.
No. 38-19574, JP-B-42-446, JP-B-42-711, a method by precipitation of a polymer shown in U.S. Pat. U.S. Pat. No. 3,914,511, U.S. Pat. No. 4,087,376, U.S. Pat.
Method using resorcinol-based wall forming material, US Pat.
No. 025445, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, Japanese Patent Publication Nos. 36-9163 and 51-9079, an in situ method by monomer polymerization, and British Patent 930.
No. 422, U.S. Pat. No. 3,111,407, Spray drying method, British Patent Nos. 952807, 96707
No. 4, but not limited thereto.

The preferred microcapsule wall used in the present invention has three-dimensional crosslinking and has a property of swelling by a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. A compound having a thermoreactive functional group may be introduced into the microcapsule wall.

The average particle size of the above microcapsules is
0.01 to 20 μm is preferred, and 0.05 to
2.0 μm is more preferred, and 0.10 to 1.0 μm is particularly preferred. Within this range, good resolution and stability over time can be obtained. In such microcapsules, the capsules may or may not be combined by heat. In short, of the microcapsule inclusions, those that oozed out of the capsule surface or outside the microcapsules during application, or those that penetrated the microcapsule wall,
A chemical reaction may be caused by heat. It may react with the added hydrophilic resin or the added low molecular compound. Alternatively, two or more types of microcapsules may be provided with functional groups that are different from each other and thermally react with each other, whereby the microcapsules may react with each other. Therefore, it is preferable from the viewpoint of image formation that the microcapsules are fused and fused by heat.
Not required.

The amount of the microcapsules added to the thermosensitive layer is
It is preferably from 10 to 60% by weight, more preferably from 15 to 40% by weight in terms of solid content. Within this range, good sensitivity and printing durability can be obtained simultaneously with good stain resistance.

When microcapsules are added to the heat-sensitive layer, a solvent in which the inclusions dissolve and the wall material swells can be added to the microcapsule dispersion medium. Such a solvent promotes diffusion of the encapsulated compound having a heat-reactive functional group out of the microcapsule. Such a solvent depends on the microcapsule dispersion medium, the material, wall thickness, and inclusions of the microcapsule wall, but can be easily selected from many commercially available solvents. For example, in the case of water-dispersible microcapsules composed of crosslinked polyurea and polyurethane walls, alcohols,
Preferred are ethers, acetals, esters, ketones, polyhydric alcohols, amides, amines, fatty acids and the like.

Specific compounds include methanol, ethanol, tertiary butanol, n-propanol, tetrahydrofuran, methyl lactate, ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, and γ-butyl lactone. , N, N-dimethylformamide, N, N-dimethylacetamide, etc., but are not limited thereto. In addition, these solvents
Two or more kinds may be used.

A solvent which does not dissolve in the microcapsule dispersion but can be dissolved by mixing the above solvent can be used. The amount of addition is determined by the combination of materials, but if it is less than the appropriate value, image formation becomes insufficient, and if it is too large, the stability of the dispersion deteriorates. Normal,
The effective range of 5 to 95% by weight of the coating solution is preferable.
10 to 90% by weight, more preferably 15 to 85% by weight.

Since the fine particle polymer or microcapsule having a thermoreactive group is used in the heat-sensitive layer of the present invention, a compound for initiating or promoting these reactions may be added as necessary. Examples of the compound that initiates or accelerates the reaction include compounds that generate radicals or cations by heat, and include, for example, lophine dimers, trihalomethyl compounds, peroxides, azo compounds, diazonium salts, and diphenyliodonium salts. Onium salts, acylphosphines, imidosulfonates and the like. These compounds can be added in the range of 1 to 20% by weight of the solid content of the heat-sensitive layer. Preferably it is in the range of 3 to 10% by weight. Within this range, a favorable reaction initiation or reaction promoting effect can be obtained.

(Hydrophilic Layer Having Cross-Linked Structure) The heat-sensitive layer of the present invention is a hydrophilic layer having a cross-linked structure, a hydrophilic resin having a cross-linked structure, and an inorganic layer formed by sol-gel conversion. In a preferred embodiment, the ink composition contains at least one hydrophilic binder resin. First, the hydrophilic resin will be described. By adding this hydrophilic resin, there is an advantage that the affinity with the hydrophilic component in the emulsion ink is improved and the film strength of the heat-sensitive layer itself is also improved. As the hydrophilic resin,
For example, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl and carboxymethyl are preferred.

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, homopolymers and copolymers of hydroxybutyl methacrylate, homopolymers and copolymers of hydroxybutyl acrylate, 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.

When the above-mentioned hydrophilic resin is used in the heat-sensitive layer according to the present invention, the hydrophilic resin may be crosslinked and used. Examples of the crosslinking agent used to form the crosslinked structure include glyoxal, melamine formaldehyde resin, aldehydes such as urea formaldehyde resin, N-methylol urea and N-methylol melamine, methylol compounds such as methylolated polyamide resin, divinyl sulfone and bis (Β-hydroxyethylsulfonic acid), active vinyl compounds, epichlorohydrin, polyethyleneglycol-glycidyl ether, polyamide, polyamine, epichlorohydrin adducts, epoxy compounds such as polyamide epichlorohydrin resin, monochloroacetic acid ester, etc. Ester compounds such as thioglycolic acid ester, polycarboxylic acids such as polyacrylic acid and methyl vinyl ether / maleic acid copolymer, boric acid, titanyl sulfate, Cu, A , Sn, V, inorganic crosslinking agents such as Cr salts, and modified polyamide polyimide resin.
In addition, a crosslinking catalyst such as ammonium chloride, a silane coupling agent, and a titanate coupling agent can be used in combination.

Further, as a preferred embodiment of the heat-sensitive layer according to the present invention, a layer containing an inorganic hydrophilic binder resin formed by sol-gel conversion can be mentioned. A preferred sol-gel conversion binder resin is such that a bonding group derived from a polyvalent element forms a network structure, that is, a three-dimensional cross-linked structure, through an oxygen atom, and at the same time, a polyvalent metal forms an unbonded hydroxyl group. Or a polymer having a resin-like structure in which these are also mixed, and are in a sol state at a stage where there are many alkoxy groups and hydroxyl groups, and are in a network form as dehydration condensation proceeds. The resin structure becomes strong. 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, a sol-gel conversion system using silicon is more preferable, and a system containing a silane compound having at least one silanol group and capable of sol-gel conversion is particularly preferable. The sol-gel conversion system using silicon will be described below. The sol-gel conversion system using aluminum, titanium, and zirconium can be implemented by substituting silicon for each element described below with each element.

The sol-gel conversion resin is preferably a resin having a siloxane bond and a silanol group,
For the heat-sensitive layer of the present invention, a sol-based coating solution containing a compound having at least one silanol group is used, and during the coating and drying process, condensation of the silanol group proceeds to gel, forming a siloxane skeleton structure. Included by the process.

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

The siloxane resin forming a gel structure is represented by the following general formula (I), and the silane compound having at least one silanol group is represented by the following general formula (II).
In addition, the substance system added to the heat-sensitive layer is not necessarily represented by the general formula (I
It is not necessary that the silane compound of the I) alone be used.
The oligomer may be a partially condensed silane compound or a mixture of the silane compound of formula (II) and the oligomer.

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The siloxane resin of the general formula (I) is formed by a sol-gel conversion from a dispersion containing at least one silane compound represented by the general formula (II). Here, at least one of R ^{01 to} R ⁰³ in the general formula (I) represents a hydroxyl group, and the other represents an organic residue selected from the symbols R ⁰ and Y in the general formula (II).

Formula (II) (R ⁰ ) _n Si (Y) _4-n

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

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

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

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

Tetrachlorosilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, 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.

In the heat-sensitive layer of the present invention, together with the silane compound of the general formula (II), a metal compound such as Ti, Zn, Sn, Zr, or Al, which can be bonded to a resin during sol-gel conversion to form a film. Can be used together. As the metal compound used, for example, Ti (OR ″) ₄ , TiCl ₄ , Zn (O
R ″) ₂ , Zn (CH ₃ COCHCOCH ₃ ) ₂ , Sn
_{(OR '') 4, Sn} (CH 3 COCHCOCH 3) 4, S
n (OCOR ″) ₄ , SnCl ₄ , Zr (O
R ″) ₄ , Zr (CH ₃ COCHCOCH ₃ ) ₄ , (NH
₄ ) ₂ ZrO (CO ₃ ) ₂ , Al (OR ″) ₃ , Al (C
H ₃ COCHCOCH ₃ ) _{3 and the} like. Where 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 promote the hydrolysis and polycondensation reaction of the compound represented by the general formula (II) and the metal compound used in combination, it is preferable to use an acid catalyst or a basic catalyst in combination. As the catalyst, an acid or basic compound used as it is or in a state of being dissolved in a solvent such as water or alcohol (hereinafter referred to as an acidic catalyst or a basic catalyst, respectively) is used. The concentration at that time is not particularly limited, but when the concentration is high, the rate of hydrolysis and polycondensation tends to increase. However, when a highly concentrated basic catalyst is used, a precipitate may be formed in the sol solution. Therefore, the concentration of the basic catalyst is preferably 1 N (concentration conversion in an aqueous solution) or less.

Specific examples of the acidic catalyst include hydrohalic acids such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid, carboxylic acids such as formic acid and acetic acid, 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 heat-sensitive layer using the sol-gel method described above is particularly preferable as a constitution of the heat-sensitive layer according to the present invention. For further details of the above sol-gel method, see "Sol-gel Method Science" by Agaku Shofusha Co., Ltd. (1988) by Sakubana Saio, and "Hiroshi Hirashima", "Functional thin film preparation by the latest sol-gel method". Technology "published by the General Technology Center (1992).

The amount of the hydrophilic resin added to the heat-sensitive layer is preferably from 5 to 70% by weight, more preferably from 5 to 50% by weight of the solids of the heat-sensitive layer.

(Light-to-heat conversion agent) The heat-sensitive layer according to the present invention comprises:
From the viewpoint of efficient formation of the hydrophobic region, it is desirable to include a photothermal conversion agent that absorbs light and generates heat. As the photothermal conversion agent used in the present invention, a substance that absorbs light of 700 nm or more is particularly preferable, and various pigments, dyes, and metal fine particles 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 polymer-bound pigments. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelated azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments And quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like.

These pigments may be used without surface treatment, or may be used after surface treatment. The method of surface treatment includes a method of surface-coating a hydrophilic resin or a lipophilic resin,
A method of attaching a surfactant, a method of bonding a reactive substance (for example, silica sol, alumina sol, a silane coupling agent, an epoxy compound, an isocyanate compound, and the like) to the surface of the pigment are considered. The above surface treatment method,
It is described in "Properties and Applications of Metal Soaps" (Koshobo), "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986). Among these pigments, those that absorb infrared rays are preferred because they are suitable for use in lasers that emit infrared rays. Carbon black is preferred as such an infrared absorbing pigment,
Carbon black whose surface is coated with a hydrophilic resin or silica sol so as to be easily dispersed in a water-soluble or hydrophilic resin and not impairing the hydrophilicity is particularly preferable. The particle size of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm.

As the dye, commercially available dyes and literatures (eg,
For example, "Dye Handbook" edited by the Society of Synthetic Organic Chemistry, published in 1970,
"Chemical Industry", May 1986, p. 45-51 `` Near infrared absorption color
”,“ Development of functional dyes and market trends in the 1990s ”, Chapter 2, 2.
3 (CMC, 1990) or in the patent
Any known dye can be used. Specifically, azo dyes, gold
Genus complex salt azo dye, pyrazolone azo dye, anthraquinone
Dye, phthalocyanine dye, carbonium dye, quinone
Infrared light such as imine dye, polymethine dye, cyanine dye
Line absorbing dyes are preferred.

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

As a dye, US Pat. No. 5,156,
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645, JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, JP-A-59-84248, and JP-A-59-84248.
No. 84249, No. 59-146063, No. 59-14
No. 6061, pyranium compounds described in JP-A-59-216146, cyanine dyes described in US Pat. No. 4,283,475, pentamethine thiopyrylium salts described in U.S. Pat. 5-70
Preferred is a pyrylium compound disclosed in JP-A No. 2 (Kokai) No. 2; commercially available products include Eporin III- manufactured by Eporin.
178, Epolite III-130, Epolite III-12
5 and the like are also preferably used. Among these, a water-soluble dye is mentioned as a preferable photothermal conversion agent to be added to a hydrophilic matrix such as a hydrophilic resin of the thermosensitive layer. Preferred specific examples of the water-soluble dye are described below [(IR-1)
To (IR-11)], but the present invention is not limited thereto.

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As a photothermal conversion agent to be added to a lipophilic substance such as fine particles of the thermosensitive layer or inclusions in microcapsules, a lipophilic dye is more preferable. Specific examples include the following dyes ((IR-12) to (IR-18)).
The present invention is not limited to these.

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The heat-sensitive layer according to the present invention contains a light-to-heat conversion agent.
Alternatively, fine metal particles can be used. As fine metal particles
Is a metal microparticle that has a photothermal conversion property and is thermally fused by light irradiation.
Any metal fine particles may be used, but preferred fine particles
The metal constituting the child is selected from Group 8 and Group 1B
Fine particles of a simple metal or an alloy, more preferably A
g, Au, Cu, Pt, Pd alone or
Alloy fine particles. Light-to-heat converter that can be added to the heat-sensitive layer
Metal fine particles having an ability to be dispersed in an aqueous solution containing a dispersion stabilizer
An aqueous solution of the above metal salt or metal complex salt is added, and a reducing agent is further added.
Add unnecessary metal to form metal colloid, then remove unnecessary salts
Obtained by: Dispersion that can be used here
Stabilizers include carboxylic acids such as citric acid and oxalic acid
And salts thereof, polyvinylpyrrolidone, polyvinylalcohol
Polymers such as polyester, gelatin and acrylic resin
be able to. Also, as a reducing agent that can be used
Is FeSO _Four , SnSO _Four Base metal salts such as borohydride
Compound, formalin, dextrin, glucose, roche
Salt, tartaric acid, sodium thiosulfate, hypophosphite, etc.
is there. The method for removing salts used in the present invention includes:
Add methanol / water or ethanol to the outer filtration method or colloidal dispersion system.
The mixture is spontaneously settled or centrifugally settled by adding
There is a method of removing the supernatant. Used in the present invention
The average diameter of the metal fine particles is preferably 1 to 500 nm,
More preferably 1 to 100 nm, particularly preferably 1 to 50 nm
nm. The degree of dispersion may be polydisperse, but the coefficient of variation is
Monodispersion of 30% or less is preferred.

The amount of the light-to-heat converting agent added to the heat-sensitive layer can be up to 30% by weight of the total solids of the heat-sensitive layer in the organic light-to-heat converting agent. It is preferably from 1 to 25% by weight, particularly preferably from 3 to 20% by weight. In the case of a metal fine particle type photothermal conversion agent, it is used in an amount of 5% by weight or more, preferably 10% by weight or more, particularly preferably 15% by weight or more of the total solids of the heat-sensitive layer. Good sensitivity is obtained within this range.

(Other Components Usable in Thermosensitive Layer) Various compounds other than those described above may be added to the thermosensitive layer according to the present invention, if necessary. For example, a polyfunctional monomer can be added to the heat-sensitive layer matrix to further improve the printing durability. As the polyfunctional monomer, those exemplified as the monomer to be put in the microcapsule can be used. Particularly preferred monomers include trimethylolpropane triacrylate.

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

In the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor to prevent unnecessary thermal polymerization of the ethylenically unsaturated compound during preparation or storage of the coating solution for the thermosensitive 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 may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the heat-sensitive layer in a drying process after coating. Good. 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 heat-sensitive layer.

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

The heat-sensitive layer of the present invention may contain inorganic fine particles. Examples of the inorganic fine particles include silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, and calcium alginate. Even if it does not have a light-to-heat conversion property, it can be used for strengthening a film or enhancing interfacial adhesion by surface roughening. The content of the inorganic fine particles in the heat-sensitive layer is from 1.0 to 7 of the total solids of the heat-sensitive layer.
It is preferably 0% by weight, more preferably 5.0 to 50% by weight. 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-like particles are
Those having an average particle size of 5 to 50 nm are preferred, and 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 heat-sensitive layer is sufficiently maintained, and the hydrophilicity is excellent in preventing the occurrence of printing stains. An image portion can be formed.
Such hydrophilic sol-like particles can be easily obtained as a commercial product such as a colloidal silica dispersion.

(Formation of heat-sensitive layer) The heat-sensitive layer of the present invention is prepared by dissolving the necessary components described above in a solvent to prepare a coating solution.
Coated on a substrate. As a solvent to be used, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, Methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyllactone, toluene, water and the like can be mentioned alone. Alternatively, they are used as a mixture, but are not limited thereto. The solid content concentration of the coating solution is preferably 1 to 50% by weight.

The dry coating amount of the heat-sensitive layer on the substrate obtained after coating and drying varies depending on the application, but is generally preferably 0.5 to 5.0 g / m ² . As a method of applying, various methods can be used, for example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating,
Roll coating and the like can be mentioned.

The coating solution for the heat-sensitive layer according to the present invention may contain a surfactant for improving coating properties, for example, JP-A-62-17.
No. 0950 can be added. The preferable addition amount is 0.01 to 1% by weight, more preferably 0.0 to 1% by weight based on the total solid content of the thermosensitive layer.
5 to 0.5% by weight.

[Heat insulation layer] The lithographic printing plate precursor used in the present invention may be provided with a heat insulation layer having a low heat conductivity and a function of suppressing heat diffusion to the support as a lower layer of the heat-sensitive layer. . Further, the heat insulating layer may contain an infrared absorbing dye. The content of this infrared absorbing dye is
It is effective for improving the heat fusion sensitivity. Such a heat insulating layer contains 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, vinylidene chloride resin, polyvinyl butyral resin, nitrocellulose, polyacrylate, polymethacrylate, polycarbonate, polyurethane,
Polystyrene, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride-acrylate copolymer, vinylidene chloride-acrylonitrile copolymer And the like.

Examples of the hydrophobic resin that can be used for the heat insulating layer include those composed of an aqueous emulsion. 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, etc.),
Conjugated diene-based polymer latex (methyl methacrylate-butadiene-based, styrene-butadiene-based, acrylonitrile-butadiene-based, chloroprene-based, etc.) and polyurethane resin.

Specific examples of the hydrophilic resin applicable to the heat insulating layer include polyvinyl alcohol (PV)
A), modified PVA such as carboxy-modified PVA, starch and its derivatives, carboxymethylcellulose, cellulose derivatives such as hydroxyethylcellulose, ammonium alginate, polyacrylic acid, polyacrylate,
Polyethylene oxide, water-soluble urethane resin, water-soluble polyester resin, polyhydroxyethyl acrylate, polyethylene glycol diacrylate-based polymer, N-vinyl carboxylic acid amide polymer, casein,
Examples include water-soluble resins such as gelatin, polyvinylpyrrolidone, vinyl acetate-crotonic acid copolymer, and styrene-maleic acid copolymer.

The above-mentioned hydrophilic resin is preferably crosslinked and cured before use. As a crosslinking agent (also referred to as a water-resistant agent), a hydrophilic resin for forming a hydrophilic matrix of the heat-sensitive layer is used. The same crosslinking agents and crosslinking catalysts can be used.

The inorganic polymer is preferably an inorganic matrix formed by sol-gel conversion. As the sol-gel conversion resin suitable for the present invention, the same sol-gel conversion resin for forming the hydrophilic matrix of the image forming layer can be used. Among these resins, a hydrophilic resin is particularly preferable from the viewpoint of adhesiveness to the image forming layer.

As the infrared absorbing dye used in the heat insulating layer, the infrared absorbing dye described in the description of the heat sensitive layer can be used. The content of the infrared absorbing dye in the heat insulating layer is preferably from 2 to 95% by weight of the solid content. In the heat insulation layer,
Various compounds other than those described above may be added for the reasons of improving the physical strength of the heat insulating layer, improving the dispersibility of the constituent components of the layer, improving the applicability, improving the adhesiveness with the image forming layer, and the like. it can. For example, inorganic fine particles, surfactants and the like can be mentioned. Specifically, those for the image forming layer,
The same addition range can be used, and the same effect can be obtained.

[Overcoat Layer] In the lithographic printing plate precursor according to the invention, a water-soluble overcoat layer can be provided on the heat-sensitive layer, if necessary, in order to prevent contamination of the surface of the heat-sensitive layer by a lipophilic substance. 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, and specifically, polyvinyl acetate (provided that the hydrolysis rate is 65%).
% Or more), polyacrylic acid, its alkali metal salt or amine salt, polyacrylic acid copolymer, its alkali metal salt or amine salt, polymethacrylic acid, its alkali metal salt or amine salt, polymethacrylic acid copolymer Coalescence, its alkali metal salt or amine salt, polyacrylamide, its copolymer, polyhydroxyethyl acrylate, polyvinylpyrrolidone, its copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer, poly-2- Acrylamide-2-
Methyl-1-propanesulfonic acid, its alkali metal salt or amine salt, poly-2-acrylamido-2-methyl-1-propanesulfonic acid copolymer, its alkali metal salt or amine salt, gum arabic, cellulose derivative ( For example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose and the like), modified products thereof, white dextrin, pullulan, enzymatically decomposed etherified dextrin and the like can be mentioned. Further, according to the purpose, two or more of these resins can be used in combination.

The above-mentioned water-soluble photothermal conversion agent may be added to the overcoat layer. Furthermore, in the case of aqueous solution application, a nonionic surfactant such as polyoxyethylene nonylphenyl ether and polyoxyethylene dodecyl ether can be added to the overcoat layer for the purpose of ensuring uniformity of application. . Dry coating amount of the overcoat layer, 0.1 to 2.0 g / m ² is preferred. Within this range, excellent contamination of the surface of the heat-sensitive layer by lipophilic substances such as fingerprint stains can be prevented.

[Support] The lithographic printing plate precursor according to the invention can be used in various forms with respect to the support. Particularly preferred is a single configuration of a metal plate whose surface is anodized using the metal plate itself as a support. The thickness of the metal plate in that case is about 0.1 to 0.6 m
m, preferably 0.15 to 0.4 mm, particularly preferably 0.2 to 0.3 mm.

Further, the metal is made of a low-cost metal plate which can be made into a thin plate (thin layer) and reinforced in terms of strength, or a highly flexible (flexible) metal plate without using the metal as a support. May be provided with a metal plate on the surface thereof, and the surface may be anodized. A preferred metal plate having high strength and low cost or high flexibility is a metal plate such as aluminum, stainless steel, nickel, and copper.
The support metal plate and the metal plate may be bonded together, or a metal may be vacuum-deposited on a thin layer on the metal plate. The former is more economical and simpler. Less than,
In the description of the present specification, when the support is a metal, the support may be referred to as a substrate in accordance with the custom in the art, but with respect to the metal, the support and the substrate are synonymous.

In addition, it is chemically stable and flexible.
Plastics such as polyesters and cellulose esters
A heat-sensitive layer can be provided on the stick support. Ma
Support for waterproof paper, polyethylene laminated paper, impregnated paper, etc.
A metal layer may be provided on the support.

Examples of preferably used plastic and paper supports include paper laminated with polyethylene, polypropylene or polystyrene, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, and the like.
Examples include plastic films such as polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, and polyvinyl acetal; paper on which aluminum is laminated or vapor-deposited; and plastic films.

Among the above, preferred supports are polyester films, aluminum, or SUS plates which are hardly corroded on a printing plate. Among them, aluminum plates which have good dimensional stability and are relatively inexpensive are particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. 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.

When an anodized substrate is used as a support, the metal support may be roughened by a known method. The surface roughening may be performed by any of mechanical means, electrochemical means, and chemical etching means, or may be performed in combination. Roughening may improve the water retention of the anodized transition metal film provided thereon. The preferred roughened metal support is an aluminum support.

When a metal support is provided separately from the substrate, the thickness of the support used is about 0.06 to 0.6 mm, preferably 0.1 to 0.4 mm, and particularly preferably 0.1 to 0.4 mm. 3 mm, and the thickness of the thin layer of the transition metal is
About 0.001 to 0.1 mm, preferably 0.005 to
0.05 mm, particularly preferably 0.01 to 0.05 mm
It is.

[Plate making and printing] The lithographic printing plate precursor according to the present invention forms an image by heat. Specifically, direct image-like recording with a thermal recording head or the like, scanning exposure with an infrared laser, high illuminance flash exposure such as a xenon discharge lamp, infrared lamp exposure, or the like is used.
Exposure with a solid-state high-output infrared laser such as a semiconductor laser or a YAG laser that emits infrared light of 00 nm is preferable. The lithographic printing plate precursor of the present invention, which has been image-exposed, can be mounted on a printing press without further processing, and can be printed in a usual procedure using ink and dampening solution. Further, as described in Japanese Patent No. 2938398, these lithographic printing plate precursors are mounted on a printing press cylinder, then exposed by a laser mounted on the printing press, and then supplied with an emulsion ink. It is also possible to print as it is.

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. Hereinafter, “parts” means “parts by weight” unless otherwise specified. [Synthesis of polymer fine particles] (Synthesis of polymer fine particles (1)) 7.5 g of allyl methacrylate, 7.5 g of butyl methacrylate, an aqueous solution of polyoxyethylene nonylphenol (concentration: 9.84 × 10
^-3 mol ^-1 ) 200 ml was added, and the system was replaced with nitrogen gas while stirring at 250 rpm. 25 of this solution
After the temperature is raised to 10 ° C., 10 ml of an aqueous cerium (IV) ammonium salt solution (concentration: 0.984 × 10 ⁻³ mol ⁻¹ ) is added.
At this time, an ammonium nitrate aqueous solution (concentration 58.8 × 1
0 ^-3 mol ^-1 ) to adjust the pH to 1.3 to 1.4. It was then stirred for 8 hours. The solid content of the liquid thus obtained was 9.5%, and the average particle size was 0.4 μm.

(Synthesis of Polymer Fine Particle (2)) Polymerization was carried out in the same manner as in Synthesis Example (1) except that 15 g of styrene was used instead of allyl methacrylate and butyl methacrylate in the synthesis of the fine particle polymer (1). The solid content concentration of the polystyrene fine particle dispersion thus obtained was 9.0% by weight, and the average particle size was 0.3 μm.

(Preparation of Microcapsule (1)) As the oil phase component, 40 g of xylene diisocyanate, 10 g of trimethylolpropane diacrylate, a copolymer of allyl methacrylate and butyl methacrylate (molar ratio: 7 /
3) 10 g, Pionin A41C (manufactured by Takemoto Yushi) 0.1
g was dissolved in 60 g of ethyl acetate. As an aqueous phase component, P
120 g of a 4% aqueous solution of VA205 (manufactured by Kuraray) was prepared. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm using a homogenizer. Thereafter, 40 g of water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The microcapsule solution thus obtained had a solid content of 20% and an average particle size of 0.5 μm.

(Example 1) <Coating of a heat-sensitive layer on a support> A water-based heat-sensitive layer coating solution having the following composition was prepared, and the surface was treated with a corona discharge treatment of 188 μm.
m of a polyester film (Toyobo A4100) having a dry film mass of 3.0 g with a bar coater.
/ M ² and applied in an oven at 100 ° C
After drying for 10 minutes, a heat-sensitive layer was formed.

(Composition of heat-sensitive layer coating solution) ・ 200 g of a 20% aqueous solution of colloidal silica ・ 49.5 g of sol-gel preparation liquid ・ 421 g of polymer fine particles (1) ・ Photothermal conversion agent [the following infrared light absorbing dye (1)] 5.00 g 324.5 g of water

[0115]

Embedded image

The polymer fine particles (1) used herein were obtained by synthesizing the polymer fine particles, and the sol-gel preparation liquid had the following composition. (Sol-gel preparation liquid: room temperature, aging for 2 hours) ・ Tetraethoxysilane 15.0 g ・ Ethanol 30.0 g ・ 0.1 mol / L nitric acid 4.5 g

When the contact angle of water droplets on the surface of the lithographic printing plate precursor obtained as described above was measured, it was confirmed that the lithographic printing plate precursor exhibited extended wetting and was a very hydrophilic surface.

<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
When exposure was performed under the condition of 0 dpi, an image region 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 110 degrees, indicating that the surface changed to a highly hydrophobic surface. Thereafter, plate making was performed without performing development processing.

<Printing> Next, the lithographic printing plate was mounted on a printing machine (Heidelberg SOR-M) and printed with an emulsion ink having the following composition. No good printed matter was obtained on 20,000 sheets. As described above, according to the method of the present invention, the lithographic printing plate precursor is not subjected to a special developing step, without causing a large number of damaged papers, and the contamination of the non-image area due to the adhesion of the ink to the hydrophilic layer. The printing durability of the resulting lithographic printing plate is practical because at least 20,000 sheets of good printed matter are obtained without causing white spots in the image area due to poor ink deposition on the hydrophobicized area. It was confirmed that the level was good without any problem.

(Emulsion ink composition 1) [Preparation of emulsion ink] (1) Preparation of varnish Varnish A: 47 parts of maleated petroleum resin (Neopolymer 120: manufactured by Nippon Oil Co., Ltd.) 53 parts of spindle oil Gel varnish B : Rosin-modified phenolic resin (Tamanol 354: manufactured by Arakawa Chemical Industries, Ltd.) 34 parts ・ Machine oil 31 parts ・ Spindle oil 31 parts ・ Aluminum stearate 4 parts Varnish C: ・ Gilsonite 25 parts ・ Machine oil 75 parts

(2) Preparation of oil-based ink component: 14 parts of carbon black 5 parts of calcium carbonate (Shiraishi DD: manufactured by Shiraishi Industry Co., Ltd.) 27 parts of varnish A 7 parts of gel varnish B 11 parts of varnish C Oil 4 parts ・ Machine oil 6 parts ・ Spindle oil 24 parts ・ Cyanine blue 1 part

(3) Preparation of hydrophilic component:-10 parts of purified water-55 parts of propylene glycol-34 parts of glycerin-Surfactant (polyoxyethylene alkyl phenyl ether, Liponox NCE: manufactured by Lion Oil & Fat Co., Ltd.) 1 Part 100 parts by weight of the oil-based ink component described in (2) and 70 parts by weight of the hydrophilic component described in (3) were stirred and mixed to prepare a W / O emulsion ink.

(Examples 2 to 4) Using the lithographic printing plate precursor prepared in Example 1 and an emulsion ink under the same conditions as in Example 1, 20% halftone dot, 50% halftone dot, and 80% halftone dot The image was exposed, and heat-fused image areas having different area ratios were formed on the exposed portion surface. After that, the printing plate was mounted on a printing machine (Heidelberg SOR-M) without performing development processing, and printing was performed. 20,000 sheets of good printed matter were obtained without any quality failure such as entanglement.
As described above, according to the planographic printing method of the present invention, it was found that a good printed matter was obtained irrespective of the area ratio of the image area / non-image area.

(Example 5) Printing was carried out in the same manner as in Example 1 except that an emulsion ink having the following composition was used. 10,000 copies were obtained. [Preparation of Emulsion Ink] (Emulsion Ink Composition 2) (1) Preparation of Varnish A gel varnish D was obtained by heating and gelling at 200 ° C. for 1 hour with the following composition.・ Rosin-modified phenolic resin (Hitanol 270T: manufactured by Hitachi Chemical Co., Ltd.) 42 parts ・ Low viscosity linseed oil polymerization varnish (2 poise) 30 parts ・ Spindle oil 27 parts ・ Ethyl acetoaceto aluminum diisopropylate 1 part (2 ) Preparation of oil-based ink component:-Gel varnish D 66 parts-Phthalocyanine blue 20 parts-Low viscosity linseed oil polymerization varnish (2 poises) 5 parts-Polyethylene wax compound 3 parts-Cobalt dryer 1 part-Spindle oil 5 parts (3) hydrophilic Preparation of the water-soluble component: ・ 100 parts of ethylene glycol

A W / O emulsion was prepared by stirring and mixing 100 parts by weight of the oily ink component obtained in (2) Preparation of the oily ink component and 45 parts by weight of the hydrophilic component obtained in (3) Preparation of the hydrophilic component. An ink was prepared.

(Examples 6 to 11) Printing evaluation was carried out in the same manner as in Example 1 except that the hydrophilic component of the emulsion ink of Composition 2 used in Example 5 was changed to the composition shown in Table 1 below. As a result, in each case, 20,000 good printed matters were obtained without stains in the non-image area and no omission in the image area. From the results of Examples 5 to 11, it can be seen that according to the lithographic printing method of the present invention, even if the composition of the emulsion ink is changed, good effects can be obtained.

[0127]

[Table 1]

(Example 12) A lithographic printing plate precursor was produced in the same manner as in Example 1 except that the polymer fine particles (1) were changed to the polymer fine particles (2) in the composition of the heat-sensitive layer coating solution of Example 1. 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, image formation and printing evaluation were similarly performed. The contact angle of water droplets on the surface of the irradiation area of the printing plate was 105 degrees, indicating that the surface changed to a highly hydrophobic surface. When printing evaluation was performed in the same manner as in Example 1,
In each case, 20,000 good prints were obtained without stains in the non-image area and no missing in the image area.

(Example 13) A lithographic printing plate precursor was prepared in the same manner as in Example 1 except that the polymer fine particles (1) were changed to the microcapsules (1) in the composition of the heat-sensitive layer coating solution of Example 1. 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, image formation and printing evaluation were similarly performed. The water droplet contact angle on the surface of the irradiation area of this printing plate was 97 degrees, indicating that the surface changed to a highly hydrophobic surface. When the printing was evaluated in the same manner as in Example 1, 20,000 sheets of good printed matter were obtained without any stains in the non-image area and no missing in the image area. Examples 12 and 13 show that according to the lithographic printing method of the present invention, good effects can be obtained even when the type of the hydrophobizing precursor contained in the heat-sensitive layer is changed.

(Example 14) <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 0.3% by mass of silicon were added. A 0.24 mm-thick rolled sheet of JISA105 aluminum material containing 0.1% by mass was coated with a 400-mesh aqueous suspension of 20% by mass of pamistone (manufactured by Kyoritsu Ceramics) and a rotating nylon brush (6.1).
0-nylon) and the surface is grained,
Washed well with water. Next, after immersing in a 10% by mass aqueous solution of sodium hydroxide at 70 ° C. for 60 seconds for etching,
It was washed with running water. Further, it was neutralized with a 20% by mass aqueous solution of nitric acid and washed with water. The obtained aluminum plate was placed in a 1.0% by mass aqueous nitric acid solution (containing 0.5% by mass of aluminum nitrate) at an anode voltage of 12.7 volts, the ratio of the amount of electricity at the cathode to the amount of electricity at the anode was 0.9, and Electrolytic surface roughening treatment was performed using a current having a rectangular wave alternating waveform under the condition of a quantity of electricity of 160 clones / dm ² . The surface roughness of the obtained substrate is 0.6
μm (Ra display). Following this treatment, 40 ° C
Was immersed in a 1% by mass aqueous sodium hydroxide solution for 30 seconds, etched, and then washed with water. Next, at 55 ° C., 30
It was immersed in a 1% by weight aqueous sulfuric acid solution for 1 minute. In addition, 35
20% by weight sulfuric acid aqueous solution at 0.8 ° C (aluminum 0.8% by weight)
), The anodic oxide film mass was 2.
Anodizing treatment was performed so as to be 5 g / dm ² . This was washed with water and dried to prepare a support. Next, a lithographic printing plate precursor was prepared in the same manner as in Example 1, except that the support of Example 1 was changed to the aluminum support, and image formation,
Printing evaluation was performed. As a result, as in the case of Example 1, 20,000 good printed materials without stains in the non-image area and without missing in the image area were obtained. In the lithographic printing method of the present invention, the same good results were obtained when an aluminum support was used as the support, as in the case where a polyester film support was used.

(Example 15) A heat insulating layer having the following composition was provided between the aluminum support and the heat-sensitive layer of Example 14, and an overcoat layer was provided on the heat-sensitive layer of Example 14.
A lithographic printing plate was produced in the same manner as in Example 14.

<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. (Insulation layer coating liquid composition)-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

<Preparation of Overcoat Layer> A coating solution having the following composition was prepared, and a 0.5 g / m ² thick overcoat layer was prepared on the heat-sensitive layer. (Composition of coating solution for overcoat layer) 350 g of a 10% solution of polyacrylic acid (average molecular weight 20,000) 2.5 g of the dye of the formula (1) (1% by mass aqueous solution) Then, image formation was performed in the same manner as in Example 1. And printing evaluation. As a result, 20,000 good prints were obtained without stains in the non-image area and no missing in the image area. As described above, it was found that the lithographic printing method of the present invention can provide a good effect which is not changed even when the heat insulating layer and the overcoat layer are present.

Comparative Example 1 Aqualess Echo Ink LZ (Toyo Ink Mfg. Co., Ltd.), a lithographic printing ink requiring no dampening solution
The print evaluation was performed in the same manner as in Example 1 except that the above was used as the printing ink. As a result, the non-image area was stained, and a good printed matter could not be obtained. As described above, when printing is performed with an oil-based ink without using the emulsion ink, the hydrophilic layer cannot sufficiently repel the ink, the non-image portion is stained, and a good printed matter can be obtained. Did not.

(Comparative Example 2) A normal PS plate having a non-image portion on the aluminum surface (V, manufactured by Fuji Photo Film Co., Ltd.)
S) was subjected to image exposure, and a lithographic printing plate obtained by carrying out genuine development processing was printed using an emulsion ink (composition 1) in the same manner as in Example 1.
A non-uniform water film was not formed due to insufficient affinity for hydrophilic components other than water in the emulsion ink on the surface thereof. Occurred, and good prints could not be obtained.

[0136]

According to the planographic printing method of the present invention, stable and high-quality printed matter can be easily obtained in planographic printing using emulsion ink, regardless of the balance between the image area and the non-image area. This has the effect.

Continued on the front page F-term (reference) 2H025 AA12 AB03 AC08 AD01 BH03 CB51 CB54 CC20 FA10 2H084 AA14 AA38 AE05 CC06 2H096 AA06 BA06 EA04 EA23 2H113 AA03 BA06 BC00 BC01 BC02 DA03 DA04 DA25 DA27 DA42 DA46 DA46 DA46 DA48 DA57 DA60 DA62 DA63 DA68 FA44 2H114 AA05 AA24 BA01 BA10 DA03 DA04 DA25 DA27 DA34 DA38 DA42 DA43 DA44 DA46 DA48 DA49 DA50 DA51 DA52 DA53 DA55 DA56 DA59 DA60 DA61 DA74 DA75 EA01 EA02 EA03 EA05 EA08

Claims (1)

[Claims] An image recording method is performed on a lithographic printing plate precursor comprising a support and a hydrophilic layer having a crosslinked structure and containing a hydrophobic precursor, and then an oil-based ink component and water and / or water. A lithographic printing method, wherein printing is performed using an emulsion ink containing a hydrophilic component containing a polyhydric alcohol as a main component.