JPH10114168A - Production of improved heat sensitive direct planography block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily provide a planography printing block having a high printing durability and a high size accuracy by providing an MC layer containing a micro capsule on a supporting member and a hydrophilic ink repellent polymer layer in a block comprising a micro capsule, a hydrophilic ink repellent polymer and a supporting member. SOLUTION: A heat sensitive direct planography block without the need of development comprises a micro capsule accommodating a lipophilic component to be converted to an image part by heat, a hydrophilic ink repellent polymer and a supporting member, wherein the polymer has a functional group capable of crosslinking three-dimensionally and a functional group to be chemically bonded with the lipophilic component in the micro capsule after the breakage of the capsule, and the lipophilic component has a functional group to be chemically bonded with the hydrophilic ink repellent polymer after the breakage of the capsule. In this case, an MC layer containing the micro capsule is provided on the supporting member, and the hydrophilic ink repellent polymer layer is provided thereon. Then, the polymer layer is crosslinked three- dimensionally before drawing an image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a heat-sensitive direct lithographic original plate which requires no development and has excellent printing durability.

[0002]

2. Description of the Related Art With the spread of computers, various lithographic plate making methods have been proposed along with a plate material configuration. From the practical point of view, it is common practice to create a positive or negative film from the plate and print it on the lithographic printing plate precursor.However, an electrophotographic plate or silver halide photographic plate that makes plate directly from the plate without passing through the film , Or electronic typesetting, DTP
A so-called computer-to-plate (C) that directly prints on a plate material with a laser or a thermal head and makes a plate without visualizing the print image information edited and created by
TP) type planographic materials are coming. These are not yet widespread, but in particular, the CTP type is greatly expected in fields such as newspaper production where CTS has been completed because the plate making process can be rationalized and shortened, and material costs can be reduced.

As such a CTP plate material, there is known a plate material which is made by photosensitivity, heat sensitivity or electric energy. The photosensitive type plate material is prepared by applying a material such as an organic semiconductor, a silver salt + photosensitive resin system, and a high-sensitivity photosensitive resin, performing printing by light irradiation with an Ar laser, a semiconductor laser, and the like, and subsequently developing the plate. You. However, these plate materials require a large and expensive manufacturing apparatus, and the plate price is higher than conventional PS plates. For this reason, these plate materials and plate making processes have not yet fully satisfied the cost reduction required by the market, and have not been widely used due to the difficulty of working in a light room. In addition, they also have the problem of disposal of the developer. In addition, there is a silver halide photographic plate for light printing, but because of its low printing durability, it is used for light printing and commercial printing in a limited range.

[0004] The present inventors have considered the plate performance of the prior art,
A heat-sensitive direct lithographic original plate improved in Japanese Patent Application Laid-Open No. 7-001849 in order to solve the problems of practical use at the commercial level in terms of plate making equipment, plate making workability, or the cost of plate materials, plate making and equipment, and a plate making method thereof Offered. However,
In the present invention, there is a troublesome condition that it is necessary to study conditions for keeping the thickness of the binder polymer on the outermost surface side of the plate within a control range according to the combination of the structure of the microcapsules and the structure of the binder polymer. Further, from the viewpoint of yield and the like, further economic efficiency has been required.

[0005]

SUMMARY OF THE INVENTION The present invention maintains the features proposed by the present inventors to solve the above-mentioned problems of the conventional direct offset printing plate material, and expresses the performance of the printing plate material in the production thereof. The purpose is to increase the stability of the plate and to obtain a plate material at a low price. That is, an object of the present invention is to provide a manufacturing method capable of easily obtaining a lithographic printing plate having high printing durability and high dimensional accuracy.

[0006]

The present invention is as follows. (1) A heat-sensitive lithographic printing plate precursor comprising a microcapsule containing a lipophilic component which is converted into an image area by heat, a hydrophilic and ink-repellent polymer and a support,
The hydrophilic and ink-repellent polymer has a functional group capable of three-dimensionally cross-linking and a functional group that chemically bonds to the lipophilic component in the microcapsule after the capsule is broken, The oily component is a method for producing a heat-sensitive direct lithographic original plate having a functional group chemically bonded to the hydrophilic and ink-repellent polymer after breaking the capsule. A method for producing a heat-sensitive direct lithographic original plate, comprising providing a hydrophilic and ink-repellent polymer layer. (2) The method for producing a heat-sensitive direct lithographic original plate as described in 1 above, wherein the polymer layer is three-dimensionally crosslinked before forming an image after forming a hydrophilic and ink-repellent polymer layer. (3) The above (1) or (2), wherein the MC layer contains a binder polymer that binds the microcapsules.
Production method of heat-sensitive lithographic original plate. (4) The method for producing a heat-sensitive direct lithographic original plate as described in (3) above, wherein the binder polymer of the MC layer is a hydrophilic polymer. (5) The method for producing a heat-sensitive direct lithographic original plate as described in (3) or (4) above, wherein the binder polymer of the MC layer contains a functional group capable of three-dimensionally crosslinking. (6) The binder polymer of the MC layer has a functional group that is chemically bonded to the lipophilic component in the microcapsule of the MC layer after the capsule is broken, and the lipophilic component in the microcapsule is the binder after the capsule is broken. The above 3, wherein the polymer has a functional group that chemically bonds to the polymer.
4. A method for producing a heat-sensitive direct lithographic master according to 4 or 5.

In the present invention, an MC layer containing microcapsules containing at least a lipophilic component which is converted into an image area by heat is formed on a support, and then a hydrophilic and ink-repellent polymer layer is formed. However, by manufacturing a heat-sensitive direct lithographic original plate by the method, the thickness of the hydrophilic and ink-repellent polymer layer present on the outermost surface side of the plate of the microcapsules can be easily controlled. As a result, it is possible to efficiently and stably produce an original plate of a heat-sensitive lithographic printing material having stable sensitivity, non-image portion printing durability, and the like.

The present invention will be described in detail. In the present invention, the MC layer preferably contains a binder polymer for dispersing and fixing the microcapsules. By containing the binder polymer in the MC layer, the microcapsules are fixed and the printing durability is improved. When the binder polymer is hydrophilic, it is more preferable because the uniformity of the hydrophilic and ink-repellent polymer layer can be easily maintained.

Further, when the binder polymer of the MC layer has a functional group capable of three-dimensionally cross-linking, or when the binder polymer of the MC layer is chemically bonded to the lipophilic component in the microcapsule after the capsule is broken. On the other hand, when the lipophilic component in the microcapsule has a functional group chemically bonded to the binder polymer after the capsule is broken, the printing durability is further improved, and high printing performance is required. It is particularly preferable because it can be used in the printing field.

[0010] In the heat-sensitive direct lithographic original plate produced by the production method of the present invention, the hydrophilic and ink-repellent polymer layer repels ink to constitute a non-image portion, but has a three-dimensional crosslinked structure during printing. It is necessary to be.
By adopting a three-dimensional cross-linked structure, the hydrophilic and ink-repellent polymer layer maintains mechanical properties and adhesive strength with the MC layer without swelling with fountain solution, and exhibits high printing durability. it can. Even if the three-dimensional crosslinked structure is formed before plate making,
It may be formed simultaneously with printing or after printing. From the viewpoint of preventing scratching during handling and preventing adhesion of hot-melted components to the thermal head when printing with the thermal head, it is preferable to form a three-dimensional cross-linked structure before plate-making. Those in which the polymer layer does not have a three-dimensional crosslinked structure before can also be used as a lithographic original plate.

In the present invention, having a functional group capable of cross-linking three-dimensionally means having a functional group capable of forming a network structure by chemically bonding to a polymer main chain or side chain;
And / or has a functional group capable of forming a network structure by chemically bonding via a crosslinking agent. The hydrophilic and ink-repellent polymer having a three-dimensionally crosslinkable functional group as referred to in the present invention is a polymer composed of carbon-carbon bonds, as a side chain, a carboxyl group, an amino group, a phosphate group, a sulfonic acid group. Or a salt thereof, a hydroxyl group, an amide group,
A hydrophilic polymer containing one or more and a plurality of hydrophilic functional groups such as polyoxyethylene groups, or carbon atoms,
Any of the carbon-carbon bonds, at least one or more oxygen, nitrogen, sulfur, a polymer connected by a hetero atom consisting of phosphorus or a side chain thereof, a carboxyl group, an amino group, a phosphate group, a sulfonic acid group, or The hydrophilic polymer containing one or more kinds of hydrophilic functional groups such as a salt, a hydroxyl group, an amide group, and a polyoxyethylene group, specifically, poly (meth) acrylate-based, polyoxyalkylene-based , Polyurethane, epoxy ring-opening addition polymerization, poly (meth) acrylic acid, poly (meth) acrylamide, polyester, polyamide, polyamine, polyvinyl, polysaccharide or composites A polymer in which a crosslinkable reactive group is introduced by a method described later, or a polymer in which a part of a hydrophilic functional group is used as a crosslinkable functional group.

The hydrophilic and ink-repellent polymer used in the present invention includes a hydroxyl group on the side chain of the segment,
Carboxyl group or its alkali metal, alkaline earth metal, amine salt, amino group or its hydrogen halide salt, sulfonic acid group or its alkali metal, alkaline earth metal, amine salt, amide group, or any combination thereof And those having a polyoxyethylene group superposed on a part of the hydrophilic functional group and the main chain segment are preferred because of high hydrophilicity.
The ratio of the hydrophilic functional groups in the hydrophilic and ink-repellent polymer is determined experimentally by the method described below for each sample, depending on the type of the main chain segment and the type of the hydrophilic functional group used. You can find it as appropriate. That is, the hydrophilicity of the hydrophilic and ink-repellent polymer of the present invention is determined by providing a hydrophilic and ink-repellent polymer layer on a support, crosslinking the ink, and performing a printing test described in Examples. Or the difference in reflection density of the paper in the non-image area before and after printing (e.g., measured with a reflection densitometer DM400 manufactured by Dainippon Screen Mfg. Co., Ltd.) or in water using water-kerosene The evaluation is made based on whether or not kerosene adheres to the sample by an oil droplet method contact angle measuring method (for example, a contact angle meter manufactured by Kyowa Interface Science, model CA-A). In the case of evaluation using the former method, it is observed with the naked eye, it is acceptable if no ink stains are found, it is not possible if it is found, or the difference between the paper reflection density of the non-image part after printing and the paper reflection density before printing. Is 0.0
A value of 2 or less is acceptable, and a value of more than 0.02 is invalid. When evaluated by the latter method, for a printing plate using a low-viscosity ink such as newspaper printing, the contact angle of the sample is about 150.
It is necessary that the angle be larger than 160 degrees, and more preferably 160 degrees or more. For a printing plate using a high viscosity ink which is used after kneading before printing, it is necessary to be larger than about 135 degrees.

Next, specific examples of the three-dimensionally crosslinkable hydrophilic and ink-repellent polymer of the present invention will be described. (Meth) acrylic acid or its alkali metal, amine salt, itaconic acid or its alkali metal, amine salt, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol (meth) acrylamide, N-
Dimethylol (meth) acrylamide, 3-vinylpropionic acid or its alkali metal, amine salt, vinylsulfonic acid or its alkali metal, amine salt, 2
-Sulfoethyl (meth) acrylate or its alkali metal, amine salt, polyoxyethylene glycol mono (meth) acrylate, 2-acrylamido-2-methylpropanesulfonic acid or its alkali metal, amine salt, acid phosphooxypolyoxyethylene glycol mono It has a hydrophilic group such as a hydroxyl group such as (meth) acrylate, allylamine or a hydrohalide thereof, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, phosphoric acid or a salt thereof, an amide group, an amino group and an ether group. A hydrophilic homo or copolymer is synthesized using at least one of the hydrophilic monomers.

Next, when these hydrophilic polymers contain functional groups such as a hydroxyl group, a carboxyl group, an amino group or a salt thereof, and an epoxy group, these functional groups are used to form a vinyl group, an allyl group, An unsaturated group-containing polymer having an ethylene addition polymerizable unsaturated group such as a (meth) acrylic group or a ring-forming group such as a cinnamoyl group, a cinnamylidene group, a cyanosinnamylidene group, or a p-phenylenediacrylate group is obtained. To this, if necessary, a monofunctional, polyfunctional monomer capable of copolymerizing with the unsaturated group, a polymerization initiator described below and other components described below are added, and water, ethanol, isopropanol, alcohols such as n-butanol,
Ketones such as acetone and methyl ethyl ketone, ethers such as diethylene glycol diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and diethylene glycol, esters such as ethyl acetate and butyl acetate, aromatic hydrocarbons such as toluene and xylene, and fats such as n-hexane and decalin The dope is dissolved or dispersed in an aromatic hydrocarbon, dimethylformamide, dimethylsulfoxide, acetonitrile or a mixed solvent thereof to adjust the dope. This is provided on the MC layer and three-dimensionally crosslinked after drying or also as drying.

When the hydrophilic and ink-repellent polymer contains an active hydrogen such as a hydroxyl group, an amino group, a carboxyl group or a sulfonic acid group, the polymer may be used together with an isocyanate compound or a blocked polyisocyanate compound and other components described below in the above solvent. To the dope to prepare a dope
It is applied on the layer and reacted after drying or also as drying to form a three-dimensional crosslink. When an active hydrogen compound is used as the solvent in this case, it is necessary to control the reaction with the isocyanate compound by controlling the temperature and concentration.

A monomer having a glycidyl group such as glycidyl (meth) acrylate and a carboxyl group such as (meth) acrylic acid can be used in combination as a copolymer component of the hydrophilic and ink-repellent polymer. When it has a glycidyl group, a polycarboxylic acid such as α, ω-alkane or alkenedicarboxylic acid such as 1,2-ethanedicarboxylic acid or adipic acid, 1,2,3-propanetricarboxylic acid, trimellitic acid or the like is used as a crosslinking agent. , 1,2-ethanediamine, diethylenediamine, diethylenetriamine, polyamine compounds such as α, ω-bis- (3-aminopropyl) -polyethylene glycol ether, oligoalkylenes such as ethylene glycol, propylene glycol, diethylene glycol and tetraethylene glycol; Using a polyhydroxy compound such as polyalkylene glycol, trimethylolpropane, glycerin, pentaerythritol, and sorbitol, three-dimensional crosslinking can be performed by utilizing a ring opening reaction with these.

When the compound has a carboxyl group, an amino group, or a hydroxyl group, ethylene or propylene glycol diglycidyl ether, polyethylene or polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether,
Using a polyepoxy compound such as 1,6-hexanediol diglycidyl ether or trimethylolpropane triglycidyl ether, three-dimensional cross-linking can be performed using an epoxy ring-opening reaction or the like.

When a polysaccharide such as a cellulose derivative, polyvinyl alcohol or a partially saponified product thereof, glycidol homo or copolymer or a base thereof is used, the above-mentioned functional group capable of undergoing a crosslinking reaction is introduced by utilizing the hydroxyl group contained therein. However, a three-dimensional crosslinked structure can be provided by the method described above. A polyol or polyamine containing a hydroxyl group or an amino group at the polymer terminal, such as polyoxyethylene glycol, and 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,6-hexamethylene diisocyanate, and isophorone diisocyanate described below. The hydrophilic polyurethane precursor synthesized from the above polyisocyanate and a polymer obtained by introducing an ethylene addition polymerizable unsaturated group or a ring-forming group can be three-dimensionally crosslinked by the method described above.

The synthesized hydrophilic polyurethane precursor is
When it has an isocyanate group terminal, glycerol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-monomethylol (meth) acrylamide, N-dimethylol (meth) acrylyl Compounds having active hydrogen such as amide, (meth) acrylic acid, cinnamic acid and cinnamic alcohol, or (meth) acrylic acid, glycidyl (meth) acrylate, 2-isocyanate when they have a hydroxyl group or amino group terminal React with ethyl (meth) acrylate.

After the application of the polybasic acid and the polyol or the polybasic acid and the polyamine, three-dimensional cross-linking is performed by heating, or hydrophilicity and ink repellency are obtained by heating using a water-soluble colloid-forming compound such as casein, glue or gelatin. The polymer layer may be three-dimensionally crosslinked to form a network structure. further,
Hydroxyl- and amino-group-containing hydrophilic polymers such as homo- or copolymers synthesized from hydroxyl-containing monomers such as 2-hydroxyethyl (meth) acrylate and vinyl alcohol and allylamine, polysaccharides such as partially saponified polyvinyl alcohol and cellulose derivatives, and glycidol homo or copolymers There is also a method of forming a network structure by three-dimensionally cross-linking a hydrophilic and ink-repellent polymer layer by using a reaction with a polybasic acid anhydride having two or more acid anhydride groups in one molecule.

Examples of polybasic acid anhydrides include ethylene glycol-bis-anhydrotrimellitate, glycerol-tris-anhydrotrimellitate, 1,3,3a,
4,5,9b hexahydro-5- (tetrahydro-
2,5-dioxo-3-furanyl) -naphtho [1,2-
C] furan-1,3-dione, 3,3 ′, 4,4′-diphenylsulfonetetracaric dianhydride, 1,2,3
Examples thereof include 4-butanetetracarboxylic dianhydride.

An active hydrogen-containing compound such as a polyamine or a polyol having an isocyanate group at the end and an active hydrogen-containing compound such as a polyamine or a polyol and other components described below are dissolved or dispersed in a solvent and coated on a support to remove the solvent. Can be cured at a temperature that does not destroy it to form a three-dimensional crosslink. In this case, hydrophilicity may be imparted by introducing a hydrophilic functional group into either or both segments and side chains of the polyurethane or the active hydrogen-containing compound. The segment and the functional group that express hydrophilicity may be appropriately selected from the above description.

Examples of polyisocyanate compounds that can be used as raw materials for polyurethane and polyurethane precursor include 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 3,3'-dimethylbiphenyl-4,4 ' −
Examples thereof include diisocyanate, triphenylmethane triisocyanate, and bicycloheptane triisocyanate.

At the time of handling before and after the coating step, it is sometimes preferable to block (mask) the isocyanate group by a known method in order to prevent the isocyanate group from changing. For example, Keiji Iwata, "Plastic Materials Course Polyurethane Resin", Nikkan Kogyo Shimbun (1974), pp. 51-52, Keiji Iwata, "Polyurethane Resin Handbook", Nikkan Kogyo Shimbun (198)
7), pages 98, 419, 423, 499, etc., sodium acid sulfite, aromatic secondary amine, tertiary alcohol, amide, phenol, lactam, heterocyclic compound, ketoxime and the like can be used. Preferably, the isocyanate regeneration temperature is low and hydrophilic, and examples thereof include sodium acid sulfite.

An addition-polymerizable unsaturated group may be introduced into any of the above-mentioned unblocked or blocked polyisocyanates and used for strengthening crosslinking or reacting with lipophilic components. The hydrophilic and ink-repellent polymer layer of the present invention and M
The binder polymer of the C layer may contain various other components described later as necessary. The degree of the degree of cross-linking, such as the average molecular weight between cross-links, varies depending on the type of segment used, the type and amount of the associative functional group, and the like, but may be determined according to the required printing durability. Usually, the average molecular weight between crosslinks is 500 to
It is set in the range of 50,000. If it is shorter than 500, it tends to be brittle, and if it is longer than 50,000, it may be unfavorable because it swells with fountain solution and printing durability is impaired. Printing durability,
800 to 30,000, even 1000 to balance hydrophilicity
About 10,000 is practical. The hydrophilic and ink repellent polymer layer of the present invention and the binder polymer of the MC layer,
The following monofunctional monomers and polyfunctional monomers may be used in combination.

Specifically, Shinzo Yamashita and Tosuke Kaneko, "Crosslinking Agent Handbook", Taiseisha Publishing Co., Ltd. (1981), and Kiyomi Kato, "Ultraviolet Curing System", published by General Technology Center (198).
9), edited by Kiyomi Kato, "UV / EB Curing Handbook (raw material)", Polymer Publishing Association (1985), supervised by Kiyoshi Akamatsu, "Practical technology of new photosensitive resin", CMC, pp. 102-14.
5, (1987), etc., N, N′-methylenebisacrylamide, (meth) acryloylmorpholine, vinylpyridine, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N
-Dimethylaminopropyl (meth) acrylamide,
N, N-dimethylaminoethyl (meth) acrylate,
N, N-diethylaminoethyl (meth) acrylate,
N, N-dimethylaminoneopentyl (meth) acrylate, N-vinyl-2-pyrrolidone, diacetone acrylamide, N-methylol (meth) acrylamide,
P-styrenesulfonic acid and its salt, methoxytriethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate (PEG number average molecular weight 400), methoxypolyethylene glycol (meth) acrylate ( Number average molecular weight of PEG 100
0), butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, dimethyloltricyclodecanedi (meth) acrylate , Polyethylene glycol di (meth) acrylate (PEG number average molecular weight 4
00), polyethylene glycol di (meth) acrylate (PEG number average molecular weight 600), polyethylene glycol di (meth) acrylate (PEG number average molecular weight 1000), polypropylene glycol di (meth) acrylate (PPG number average molecular weight 400), 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane Or its acrylate, β- (meth) acryloyloxyethyl hydrogen phthalate, β- (meth) acryloyloxyethylhadogen succinate, polyethylene or polypropylene glycol mono (meth) acrylate, 3-chloro-2 -Hydroxypropyl (meth)
Acrylate, 1,3-butylene glycol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, Isobornyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate,
Stearyl (meth) acrylate, isodecyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Tetrafurfuryl (meth) acrylate, benzyl (meth) acrylate, mono (2-acryloyloxyethyl) acid phosphate or its methacrylic body, glycerin mono or di (meth) acrylate, tris (2-acryloxyethyl) isocyanurate or its Examples include methacrylic bodies, N-phenylmaleimide, N- (meth) acryloxysuccinimide, N-vinylcarbazole, divinylethyleneurea, divinylpropyleneurea and the like. The hydrophilic and ink-repellent polymer of the present invention needs to have a functional group that chemically bonds to the lipophilic component in the microcapsule. High printing durability is obtained by the chemical bonding of the two. In order to improve the printing durability, the chemical bond preferably has a three-dimensional crosslinked structure. In order to react the lipophilic component in the microcapsule with the hydrophilic and ink-repellent polymer, the reactive group of the hydrophilic and ink-repellent polymer is adjusted to the reactive functional group of the lipophilic component described below. What is necessary is just to introduce | transduce into a copolymerization monomer, or after polymer synthesis. A reaction having a high reaction rate is preferable, and examples thereof include an addition polymerization reaction of an unsaturated group, a urethane reaction, which is a reaction between an isocyanate group and active hydrogen, a urea reaction, and a reaction between an amino group and an epoxy group. In addition, a ring-opening addition reaction such as a carboxyl group, a reaction between a hydroxyl group and an epoxy group, a Michael addition reaction between an amino group and a (meth) acryloyl group, a reaction between an acid anhydride group and a hydroxyl group, an amino group or an imino group, or an unsaturated group An addition reaction of thiol with thiol can also be used.

In the present invention, a functional group for three-dimensionally cross-linking the hydrophilic and ink-repellent polymer, a lipophilic component in the microcapsule, and a hydrophilic and ink-repellent polymer are reacted. The functional groups may have the same structure. In this case, the degree of reactivity may be controlled according to the concentration of the crosslinking agent or the reaction time. When a three-dimensional crosslinking reaction of a hydrophilic and ink-repellent polymer is performed using an ethylene addition-polymerizable unsaturated group, a photopolymerization initiator such as a known photoradical polymerization initiator or a photocationic polymerization initiator or a thermal polymerization initiator is used. It is preferable to use an agent in terms of reaction efficiency.

Examples of the photoradical polymerization initiator include benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, Michler's ketone, xanthone, thioxanthone, chloroxanthone, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-
1-one, benzyl, 2,2-dimethyl-2-hydroxyacetophenone, (2-acryloyloxyethyl)
(4-benzoylbenzyl) dimethylammonium bromide, (4-benzoylbenzyl) trimethylammonium chloride, 2- (3-dimethylamino-2-hydroxypropoxy) -3,4-dimethyl-9H-thioxanthone-9-one mesochloride , 1-phenyl-1,2-propanedione-2- (O-benzoyl) oxime, thiophenol, 2-benzothiazole thiol, 2-benzoxazole thiol, 2-benzimidazole thiol, diphenyl sulfide, decyl phenyl sulfide, -N-butyl disulfide, dibenzyl sulfide, dibenzoyl disulfide, diacetyl disulfide, dibornyl disulfide dimethoxyxanthogen disulfide, tetramethylthiuram monosulfide, tetramethylthiuram Torasurufido, benzyl dimethyl dithiocarbamate quinoxaline, 1,3-dioxolane, N- lauryl pyridinium and the like. From these, those which have absorption in the wavelength region of the light source used in the production process and which are dissolved or dispersed in the solvent used when preparing the dope of the hydrophilic and ink-repellent polymer layer may be appropriately selected. Usually, those that dissolve in the solvent used are preferred because of their high reaction efficiency.

Examples of the cationic photopolymerization initiator include aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts. When this initiator is used, an epoxy group can also be used as a cross-linking reactive species. The epoxy group-containing compound may be used as a crosslinking agent or a hydrophilic and ink-repellent polymer, or an epoxy group may be introduced into the hydrophilic and ink-repellent polymer. When three-dimensionally cross-linking is performed by a photodimerization reaction of a functional group contained in a hydrophilic and ink-repellent polymer, various sensitizations commonly known in the reaction, such as 2-nitrofluorene and 5-nitroacenaphthene, are used. Agents can also be used.

In addition to the above, "Sensitizer" by Katsumi Tokumaru et al.,
Chapters 2 and 4, Kodansha (1987), Kiyomi Kato, "Ultraviolet Curing System", published by General Technology Center, page 62-14.
7 (1989), Fine Chemicals, Vol. 20 N
o4, p. 16 (1991) can also be used. The addition amount of the photopolymerization initiator and the sensitizer for the photodimerization reaction is 0. 0 to the active ingredient excluding the solvent in the dope for forming the hydrophilic and ink-repellent polymer layer.
It can be used in the range of 01 to 20% by weight. 0.01% by weight
If the amount is less than the above, the effect of the photopolymerization initiator or the sensitizer of the photodimerization reaction will not be exhibited. In some cases, the light may not reach the inside, and the desired printing durability may not be exhibited. Practically, it is preferable to determine the content in the range of 0.1 to 10% by weight according to the composition in consideration of the balance between the effect as an initiator and the background stain in the non-image area.

As the irradiation light source, a known light source can be used for the type of actinic ray, and it is adjusted to the wavelength characteristics of a photopolymerization initiator, a sensitizer for a photodimerization reaction, or a sensitizer for the polymerization initiator used in combination. Just choose. Specific examples include chemical lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps,
There are germicidal lamps, metal halide lamps and so on. When there is a risk of capsule destruction due to heat from the irradiation light source, it is necessary to irradiate while cooling.

Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylpropionamidine) dihydrochloride,
2'-azobis [2- (2-imidazolin-2-yl)
Propane] dihydrochloride, benzoyl peroxide,
Known compounds such as persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, azo compounds such as persulfate-sodium bisulfite, peroxides and redox initiators can be used. When used, the microcapsules must be reacted at a lower temperature than the temperature at which the microcapsules are destroyed or the decomposition temperature of the thermal polymerization initiator used as a thermal polymerization initiator for the lipophilic component, which will be described later, is lower. Therefore,
It is necessary to mix and apply the dope of the hydrophilic and ink-repellent polymer layer at a lower temperature than the photopolymerization method. The amount of the thermal polymerization initiator to be used is 0.01 to
A range of 10% by weight is good. If the amount is less than 0.01% by weight, the curing time becomes too long. If the amount is more than 10% by weight, gelation may occur due to decomposition of the thermal polymerization initiator generated during dope preparation. In consideration of the effect and handleability, the content is preferably 0.1 to 5% by weight.

The lipophilic component in the microcapsule of the present invention has a functional group that reacts with the hydrophilic and ink-repellent polymer. When the lipophilic component released outside the capsule by thermal printing reacts with the hydrophilic and ink-repellent polymer to form a chemical bond, an image portion having high printing durability can be formed. In order to further improve the printing durability, it is preferable that the image portion has a crosslinked structure.

The reaction between the hydrophilic and ink-repellent polymer and the lipophilic component is carried out at a high reaction rate, for example, a reaction between a hydrophilic and ink-repellent polymer having a hydroxyl group or a carboxyl group or an amino group and a lipophilic component having an isocyanate group. Urethane reaction or urea reaction with oily components,
Reaction of hydrophilic and ink repellent polymer having hydroxyl group, carboxyl group or amino group with lipophilic component having epoxy group, or addition polymerization reaction of ethylene addition polymerizable double bond, Michael addition of unsaturated group and amino group Reaction is preferred. A ring-opening addition reaction between a hydrophilic and ink-repellent polymer having an acid anhydride group and a lipophilic component having a hydroxyl group, an amino group or an imino group or an addition reaction between an unsaturated group and a thiol may be used. In order to improve the printing durability, the chemical bond formed by these reactions preferably has a three-dimensional crosslinked structure.

The lipophilic component of the present invention includes, for example, styrene, divinylbenzene, N, N'-diethylaminoethyl (meth) acrylate, N, N'-dimethylaminoneopentyl (meth) acrylate, butoxyethyl (meth) acrylate Phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyethylene glycol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, diethylene glycol di (meth) acrylate, tetra Ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate (PEG number average molecular weight 400), polypropylene glycol di (meth) acrylate (PPG number-average molecular weight 4
00), 3-chloro-2-hydroxypropyl (meth)
Acrylate, 1,3-butylene glycol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, Isobornyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-
Butyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, isodecyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrafurfuryl (meth) acrylate, benzyl (meth) acrylate, Glycidyl (meth) acrylate, Tris (2
(Acryloxyethyl) isocyanurate or a methacrylic body thereof, (meth) acrylic monomers such as 2-isocyanatoethyl (meth) acrylate; propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neo Epoxide compounds such as pentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether; phenyl isocyanate;
4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 1,5-naphthalenediisocyanate, 1,6-hexamethylene Diisocyanate, isophorone diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, bicycloheptane triisocyanate, polymethylene polyphenyl isocyanate, polymeric polyisocyanate, 3,
Isocyanates such as 3'-dichlorobiphenyl-4,4'-diisocyanate; trimethylolpropane and 1,
Polyisocyanates such as 6-hexane diisocyanate, 2,4-tolylene diisocyanate or 1,3-mol adducts with the above diisocyanates such as 2,6-tolylene diisocyanate, oligomers or polymers of 2-isocyanatoethyl (meth) acrylate, etc. Isocyanate compounds and the like can be used. In addition, existing PS
Known prior to crosslinking used as an image component of the plate,
(Meth) acrylic copolymers and urethane acrylates,
Diazo resins can also be used. Further, some isocyanate groups in the polyisocyanate compound and 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerol mono- or di (meth) acrylate, (meth) acrylic acid, β −
Hydroxyl group such as (meth) acryloyloxyethyl hydrogen succinate, an adduct with an active hydrogen-containing monofunctional or polyfunctional (meth) acrylate compound such as a carboxyl group, 2-isocyanatoethyl (meth) acrylate,
Some glycidyl groups in the polyfunctional glycidyl compound and 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerol mono- or di (meth) acrylate, (meth) acrylic acid, β- ( Adducts with monofunctional or polyfunctional (meth) acrylate compounds containing active hydrogen such as hydroxyl group and carboxyl group such as (meth) acryloyloxyethyl hydrogen succinate, and some acid anhydride groups in the above-mentioned polybasic acid anhydrides And 2-hydroxyethyl (meth) acrylate, 2
-Adducts with hydroxyl-containing monofunctional or polyfunctional (meth) acrylate compounds such as hydroxypropyl (meth) acrylate, glycerol mono- or di (meth) acrylate.

Among these, when a compound containing an isocyanate group is used, when water is used as a dispersion medium at the time of microencapsulation, the reactivity with water is high, and therefore, for example, paraffin wax, carnauba wax, etc. Mineral oils such as waxes, castor oil and linseed oil; oils such as dimethyl silicone; ketones such as diethyl ketone, phenylethyl ketone, diphenyl ketone and methyl ethyl ketone; ethers such as diisopropyl ether and diethyl ether; esters such as ethyl acetate and butyl acetate. , Aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as n-hexane and decalin, halogenated hydrocarbons such as methylene chloride and chloroform, and diluents with water-insoluble compounds such as mixed solvents thereof. It may be necessary to control the reaction by Runado.

Further, as in the case of producing microcapsules having a urethane / urea wall by using an isocyanate group-containing compound as an inclusion, a reactive compound added to an oil component for forming a wall and a reactive group in the inclusion. In the case of having similar reactivity, or when the inclusions and the wall forming material are the same, the reaction is controlled by the concentration of the reaction couple added to the dispersion medium side during microencapsulation, and the wall thickness etc. is controlled You may need to.

When a lipophilic component and a hydrophilic and ink-repellent polymer are chemically reacted by utilizing a double bond reaction of an ethylene addition polymerizable monomer or oligomer contained in the lipophilic component, or as described above, When the lipophilic component itself undergoes a crosslinking reaction to improve printing durability, the following thermal polymerization initiator can be used. The thermal polymerization initiator is preferably stable even when stored at 50 ° C. or lower, and more preferably stable at 60 ° C. or lower.

For example, methyl ethyl ketone peroxide, cyclohexanone peroxide, n-butyl 4,4-bis (t-butylperoxy) valerate,
1,1-bis (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) butane, cumene hydroperoxide, p-menthane hydroperoxide, di-t-butyl peroxide, t -Butylcumyl peroxide, dicumyl peroxide,
t-butyl peroxy laurate, t-butyl peroxy isopropyl carbonate, t-hexyl peroxy benzoate, t-butyl peroxy benzoate, t
-Butyl peroxyacetate, 2,2′-azobis (2,4,4-trimethylpentane), 1,1-azobis (cyclohexane-1-carbonitrile), 2,2 ′
-Azobisisobutyronitrile, 2,2'-azobis
Peroxides such as [2-methyl-N- (2-hydroxyethyl) -propionamide] and azo compounds.

As a method for adding the thermal polymerization initiator, the polymer may be microencapsulated and used in the form of a capsule-in-capsule in the microcapsule of the lipophilic component. It may be directly dispersed in the binder polymer of the layer. The curing of the lipophilic component can utilize not only a polymerization reaction but also a reaction at the time of chemical bonding between the lipophilic component and a hydrophilic and ink-repellent polymer or a binder polymer of the MC layer.

The amount of the thermal polymerization initiator to be used is 0.01 to 0.01 with respect to the components excluding the solvent of the dope for forming the hydrophilic and ink-repellent polymer layer and the dope for the binder polymer of the MC layer.
A range of 10% by weight is good. If the amount is less than 0.01% by weight, the curing time becomes too long. If the amount is more than 10% by weight, gelation may occur due to decomposition of the thermal polymerization initiator generated during dope preparation. In consideration of the effect and handleability, the content is preferably 0.1 to 5% by weight. When added in the form of capsule-in-capsule in microcapsules,
The amount of the thermal polymerization initiator is usually used in the range of 0.01 to 10% by weight based on the total weight of the capsule-in-capsule.

In the present invention, a photopolymerization initiator such as a photoradical polymerization initiator or a photocationic polymerization initiator can be used for the purpose of increasing the reactivity of the lipophilic component in the image area formed after thermal printing. The initiator causes the reaction of the photoreactive functional group contained in the lipophilic component to proceed by irradiation with actinic light.
Irradiation with actinic light prior to thermal printing does not break the microcapsules, so that no image area is formed, and the above-mentioned object cannot be achieved. Irradiation with actinic rays after thermal printing can increase the reactivity of the lipophilic component in the image area, and can significantly improve the printing durability of the image area.

Examples of the photo-radical polymerization initiator include the following known compounds. Benzophenone, xanthone, thioxanthone, 2-chlorothioxanthone, 2
-Ethylanthraquinone, acetophenone, trichloroacetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-propiophenone, benzoin alkyl ether, 2,2-diethoxyacetophenone, 2,2 -Dimethoxy-2-phenylacetophenone, benzyl, 1-phenyl-1,
2-propanedione-2- (O-benzoyl) oxime, thiophenol, 2-benzothiazolethiol,
2-benzoxazole thiol, 2-benzimidazole thiol, diphenyl sulfide, decyl phenyl sulfide, di-n-butyl disulfide, dibenzyl sulfide, dibenzoyl disulfide, diacetyl disulfide, dibornyl disulfide, dimethoxyxanthogen disulfide, tetramethylthiuram mono Sulfide, tetramethylthiuram tetrasulfide, benzyldimethyldithiocarbamate, quinoxaline, 1,
3-dioxolan, N-laurylpyridinium, (2-
(Acryloyloxyethyl) (4-benzoylbenzyl) dimethylammonium bromide, (4-benzoylbenzyl) trimethylammonium chloride, 2- (3-dimethylamino-2-hydroxypropoxy) -3,4-dimethyl-9H-thioxanthone-9 -On mesochloride.

Further, examples of the cationic photopolymerization initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts and the like. In addition to the above, many known polymerization initiators can be used. These are, for example, Katsumi Tokumaru et al., "Sensitizers", published by Kodansha (1987), and Kiyomi Kato, "Ultraviolet curing system", published by General Technology Center (1989). Etc.,
Fine Chemical, Vol. 20 No. 4, 16 (19
91).

The addition amount of the photopolymerization initiator can be used in the range of 0.01 to 20% by weight based on the components after drying of the coating film formed on the support. If less than 0.01% by weight, photopolymerization
If the effect of the initiator is not exerted, and if the content is more than 20% by weight, there are cases where the light reaches the inside due to self-absorption of the actinic ray by the initiator and the desired printing durability cannot be exhibited. Is not preferred. Practically, it is preferable to determine the content in the range of 0.1 to 10% by weight according to the composition in consideration of the balance between the effect as an initiator and the background stain in the non-image area.

The photopolymerization initiator may be contained in the same microcapsule as the lipophilic component, or may be dispersed in the hydrophilic and ink-repellent polymer layer or the binder polymer of the MC layer. For the reaction, it is preferable to include the lipophilic component in the same microcapsule. If the storage stability of the lipophilic component is reduced by inclusion, a known phenolic heat stabilizer such as 2,6-di-t-butylparacresol or paramethoxyphenol may be used in combination or a lipophilic component. The microcapsules enclosing the components can be once wrapped in microcapsules smaller than the microcapsules, mixed with the lipophilic components during microcapsulation of the lipophilic components, and used in the form of capsule-in-capsules.

If the hydrophilic and ink-repellent polymer layer and the binder polymer in the MC layer are subjected to a three-dimensional crosslinking reaction by photopolymerization, and a photoreaction after thermal printing in microcapsules containing an lipophilic component. When coexisting for the photopolymerization initiator, the excitation wavelength of the former photopolymerization initiator and the excitation wavelength of the latter photopolymerization initiator are different, and further, the emission wavelength used by the irradiation light source is also different,
During the photocrosslinking reaction of the binder polymer of the hydrophilic and ink-repellent polymer layer or the MC layer, the lipophilic component must be prevented from curing in the microcapsules. To use different wavelengths, light sources having different emission wavelength distributions may be used, or different wavelengths may be extracted by a combination of bandpass filters.

The encapsulation of the lipophilic component is performed according to a known method described in, for example, “New Technology of Microencapsulation and Its Application Development / Application Examples”, edited by the Business Development Center, Business Development Center, published by the Business Development Center Publishing Company (1978). For example, at the interface between two liquids that do not dissolve in each other, reactants added to each liquid in advance by polycondensation or polyaddition, and an unnecessary polymer film is formed in both solvents to form an interface for forming a capsule film. A polymerization method, an in-situ method in which a reactant is supplied from only one of the inside and the outside of the core material and a polymer wall is formed around the core material, and the surface of a hydrophobic material dispersed in a hydrophilic polymer solution is And a complex coacervate method in which a hydrophilic polymer is phase-separated to form a capsule membrane, a phase separation method from an organic solution system, or the like. Among them, interfacial polymerization, in-s
The itu method is preferable because relatively many core substances can be easily encapsulated. It may be encapsulated in a material different from the lipophilic component.

The encapsulation referred to in the present invention is to finely powder a polyisocyanate compound which is solid at room temperature, and to block the surface of the fine powder with the blocking agent or the like so that it cannot react with surrounding active hydrogen at room temperature. And a method of pulverizing a solid polyisocyanate compound at room temperature and reacting the surface with water, a polyfunctional alcohol, or a polyfunctional amine to form a wall. In any case, it is necessary that the lipophilic component in the capsule is released outside the capsule due to the heat at the time of printing, and the form of the first capsule is destroyed. For example, by expansion, compression, melting, and chemical decomposition of the capsule wall,
In some cases, the lipophilic component is released, or the wall material of the capsule expands, the density decreases, and the lipophilic component is released through the wall material layer.

The surface of the capsule shell is not particularly limited, but is preferably a material that is easily dispersed in the dispersion medium and does not dissolve. Microcapsule size is 10 μm or less on average, and 5 μm on average for high resolution applications
The following is preferred. If the ratio of the lipophilic component to the whole capsule is too low, the image forming efficiency is reduced.
It is preferably 1 μm or more.

In the present invention, as other components, promotion of thermal destruction of capsules, promotion of reaction between a lipophilic component and a reactant having a functional group which reacts with the component, a hydrophilic and ink repellent polymer with a lipophilic component, A sensitizer can be further added for the purpose of accelerating the reaction of the MC layer with the binder polymer. By the addition, printing sensitivity can be increased, printing durability can be improved, and high-speed plate making can be performed. Such sensitizers include, for example, autooxidants such as nitrocellulose, substituted cyclopropanes, and high strain compounds such as cubane.

A polymerization reaction catalyst for a lipophilic component can also be used as a sensitizer. For example, if the reaction of the lipophilic component is a reaction of an isocyanate group, a urethanization catalyst such as dibutyltin dilaurate, stannic chloride, or an amine compound, or a ring opening reaction of an epoxy group such as a quaternary ammonium salt. A ring catalyst can be exemplified. The sensitizer may be added at the time of preparing the dope of the MC layer, may be included simultaneously with microencapsulation of the lipophilic component, or may be provided together with a binder resin between the support and the MC layer. There is a method of mixing with the ink repellent polymer layer. The amount to be used may be determined from the viewpoint of the effect of the sensitizer used, the non-image quality of the non-image area, and the printing durability.

In the case of laser printing, a light-to-heat conversion material having an absorption band in the emission wavelength region of the laser to be used can be further used. Examples of such substances include, for example, Ken Matsuoka, "JOEM Handbook 2, Absorption Spectrum of Soy for Diode Lasers," Bunshin Publishing (1990), CMC Editing Department, "Development and Market Trend of 90s Functional Dyes", CMC ( 1990) Polymethine dyes (cyanine dyes), phthalocyanine dyes, dithiol metal complex dyes, naphthoquinones, anthraquinone dyes, triphenylmethane dyes, aminium, diimmonium dyes, azo dyes described in Chapter 2, 2.3 There are dyes, pigments and dyes such as system disperse dyes, indoaniline metal complex dyes, and intermolecular CT dyes.

Specifically, N- [4- [5- (4-dimethylamino-2-methylphenyl) -2,4-pentadienylidene] -3-methyl-2,5-cyclohexadiene-1 -Ylidene] -N, N-dimethylammonium acetate, N- [4- [5- (4-dimethylaminophenyl) -3-phenyl-2-penten-4-yn-1-
[Ylidene] -2,5-cyclohexadiene-1-ylidene] -N, N-dimethylammonium perchlorate, N, N-bis (4-dibutylaminophenyl) -N
-[4- [N, N-bis (4-dibutylaminophenyl) amino] phenyl] -aminium hexafluoroantimonate, 5-amino-2,3-dicyano-8-
(4-ethoxyphenylamino) -1,4-naphthoquinone, N'-cyano-N- (4-diethylamino-2-methylphenyl) -1,4-naphthoquinonediimine, 4,
11-diamino-2- (3-methoxybutyl) -1-oxo-3-thioxopyrrolo [3,4-b] anthracene-5,10-dione, 5,16 (5H, 16H) -diaza-2-butylamino -10,11-Dithiazinaphtho [2,3-a: 2′3′-c] -naphthalene-1,4-
Dione, bis (dichlorobenzene-1,2-dithiol) nickel (2: 1) tetrabutylammonium, tetrachlorophthalocyanine aluminum chloride,
Polyvinylcarbazole-2,3-dicyano-5-nitro-1,4-naphthoquinone complex, N, N-diethyl-N
-[4- [1,5,5-tris (4-diethylaminophenyl) -2,4-pentadienylidene] -2,5-cyclohexadiene-1-ylidene] ammonium perchlorate. For the purpose of accelerating the thermal destruction of the microcapsules, a substance which tends to evaporate or expand when heated with the lipophilic component can be placed in the capsule together with the lipophilic component. For example, hydrocarbons such as cyclohexane, diisopropyl ether, ethyl acetate, ethyl methyl ketone, tetrahydrofuran, t-butanol, isopropanol, 1,1,1-trichloroethane, whose boiling point is sufficiently higher than room temperature and hydrocarbons around 60 to 100 ° C., Halogenated hydrocarbons, alcohols, ethers, esters and ketone compounds.

It is preferable to use a known thermosensitive dye which develops color only in the printed portion in combination with a lipophilic component to visualize the printed portion, because plate inspection is easily performed. For example, 3-diethylamino-
There is a combination of 6-methyl-7-anilinofluoran with a leuco dye such as bisphenol A and a ground developer. Shin Okawara et al. “Dye Handbook” published by Kodansha (1
986) and the like.

In addition to the hydrophilic and ink-repellent polymer and the binder polymer of the MC layer, a reactive substance having a functional group that reacts with the lipophilic component can be used to increase the degree of crosslinking of the lipophilic component. The amount of addition is determined so as not to cause background fouling according to the degree of ink repellency and hydrophilicity of the hydrophilic and ink repellent polymer layer. Examples of such a reactive substance include, for example, a compound having a plurality of hydroxyl groups, amino groups, and carboxyl groups, such as polyvinyl alcohol, polyamine, polyacrylic acid, and trimethylolpropane when the crosslinking reaction of the lipophilic component is urethane.

The MC used for the purpose of adjusting hydrophilicity
Non-reactive hydrophilic polymer that does not react with the binder polymer, lipophilic component and hydrophilic and ink-repellent polymer of the layer is added to the hydrophilic and ink-repellent polymer layer and the binder polymer of the MC layer as long as the printing durability is not impaired. May be. When printing with a thermal head, calcium carbonate, silica, zinc oxide, titanium oxide, kaolin, calcined kaolin, hydrohaloisite, as an absorbent of the melt for the purpose of preventing the melt generated by heating from adhering to the thermal head Known compounds such as alumina sol, diatomaceous earth, and talc can be added.

Further, it is also used to improve the slipperiness of the plate and to prevent the plate from sticking when the plates are overlapped. A small amount of a lubricant can be added to the hydrophilic and ink-repellent polymer layer.
The binder polymer of the MC layer used in the present invention may be any substance as long as it is a polymer material having a molecular weight of 500 or more, preferably 1,000 or more. However, when using a hydrophilic compound as exemplified as the hydrophilic and ink-repellent polymer layer forming material, so-called repelling hardly occurs when the hydrophilic and ink-repellent polymer layer is formed, This is preferable because the ink-repellent polymer layer can be easily and uniformly provided. Also, M
When the binder polymer of the C layer is three-dimensionally crosslinked by the method exemplified for the hydrophilic and ink-repellent polymer layer forming material, the MC layer does not swell at the time of printing, and especially printing durability is required. It is preferred when providing a plate for use in the printing field.

Further, when the binder polymer of the MC layer has a reactive group capable of reacting with the lipophilic functional group encapsulated in the microcapsule, it is preferable for obtaining a plate having high printing durability in the image area. Specifically, functional groups as exemplified as the hydrophilic and ink-repellent polymer layer forming material can be used. As described above, as the composition of the binder polymer of the MC layer, a substance having performance similar to that of the hydrophilic and ink-repellent polymer layer forming material is preferably used. Need not be the composition of In other words, the hydrophilic and ink-repellent polymer layer forming material must be a three-dimensionally crosslinked ink-repellent polymer that exhibits non-image performance during printing and has high printing durability, It is not necessary that the binder polymer of the MC layer retain its performance, but rather it is an essential requirement that the polymer be a polymer that disperses the microcapsules well and firmly anchors the microcapsules.

Further, as the binder polymer of the MC layer, a protective colloid agent or the like at the time of preparing microcapsules can be used. Regarding the protective colloid agent, known substances described in, for example, "Microcapsules and Their Functions and Applications" edited by Tamotsu Kondo et al. And water-soluble alginic acid or derivatives thereof.

In the MC layer, the initiators, reaction catalysts, cross-linking agents and other additives exemplified for the hydrophilic and ink-repellent polymer layer can be appropriately used. The support used in the present invention may be selected from known materials in consideration of the performance and cost required in the printing field. When high dimensional accuracy such as multicolor printing is required, and when used in a printing machine whose mounting method to the plate cylinder is completed according to the metal support, a metal support made of aluminum, steel, or the like is preferable. In the case where high printing durability is required without multicolor printing, a plastic support such as polyester can be used, and in the field where low cost is required, paper, synthetic paper, waterproof resin laminate or coated paper support can be used. The support itself may be subjected to a surface treatment in order to improve the adhesiveness to a material that comes into contact with the support. Examples of such a surface treatment include various polishing treatments and anodizing treatments for aluminum sheets, and corona discharge treatments and blast treatments for plastic sheets.

The above materials are used as a base material if necessary, such as printing durability,
A support provided with an adhesive layer thereon can be used. Generally, when high printing durability is required, an adhesive layer is provided. The adhesive must be selected and designed according to the MC layer component and the base material used. Acrylics, urethanes, celluloses, epoxies, etc., described in “Encyclopedia of Adhesion and Adhesion”, Asakura Shoten, published by Asakura Shoten (1986), edited by the Adhesion Association of Japan, published by Nihon Kogyo Shimbun (1980), etc. A support provided with an adhesive on a substrate can be used. Furthermore, a lithographic printing plate support proposed by the present inventors in Japanese Patent Application No. 07-334866 can be exemplified.

The heat-sensitive direct lithographic original plate of the present invention can be produced by the following method. The dispersion liquid of the MC layer is well dispersed with a solvent selected according to the above-mentioned components using a stirring motor, a paint shaker, a ball mill, an ultrasonic homogenizer, a sand grinder, etc., and a doctor blade method, a bar coating method, a roll coating method, a spray coating method Provided on a support by a curtain coating method, a dip coating method, etc., dried if necessary, and crosslinked the binder polymer as necessary,
Furthermore, a solution or dispersion of a hydrophilic and ink-repellent polymer is provided in a manner similar to the MC layer described above,
Dry and, if necessary, a hydrophilic and ink-repellent polymer or M
The binder polymer of the layer C is crosslinked to obtain a heat-sensitive direct planographic printing plate precursor. When a component containing an ethylene addition-polymerizable unsaturated group is used, if necessary for storage stability, the known heat stabilizer is added to the MC layer component or the hydrophilic and ink-repellent polymer layer component in a dope of 0.01%. You may add in the range of -5%.

Water, alcohols such as ethanol, isopropanol and n-butanol are used as dope solvents for the MC layer component and the hydrophilic and ink-repellent polymer layer component.
Ketones such as acetone and methyl ethyl ketone, ethers such as diethylene glycol diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and diethylene glycol, esters such as ethyl acetate and butyl acetate, aromatic hydrocarbons such as toluene and xylene, and fats such as n-hexane and decalin An aromatic hydrocarbon, dimethylformamide, dimethylsulfoxide, acetonitrile, or a mixed solvent thereof can be used.

The thickness of the MC layer may be arbitrarily set between several μm and 100 μm. Usually, a thickness of 1 to 10 μm is preferable from the relationship between performance and cost. If it is necessary to enhance the surface smoothness, calendering may be performed after coating and drying or after the three-dimensional crosslinking reaction of the binder polymer in the MC layer. In particular, if a high degree of smoothness is required, it is preferable to carry out after coating and drying.

The concentration of the microcapsules in the dope of the MC layer is not particularly limited, but it is usually used in the range of 0.5% by weight to 70% by weight, more preferably 1% by weight, from the viewpoint of handleability. % To 50% by weight. The coating thickness of the hydrophilic and ink-repellent polymer layer can be arbitrarily set depending on the dope concentration so that the thickness from the outer surface of the microcapsules to the outermost surface of the plate after drying falls within a thickness of 0.005 μm to 5 μm. Is preferred. Normally, the concentration of the dope is 0.1.
It is used in the range of 0.5 to 30% by weight. 0.05% by weight
If the ratio is less than the above range, repelling may occur when applied on the MC layer, resulting in non-uniformity. On the other hand, when the concentration is higher than 30% by weight, the viscosity becomes too high and handling becomes difficult. The thickness of the coating containing the solvent of the dope before drying is not particularly limited, but is usually in the range of 0.5 to 500 μm.

The thickness from the outer surface of the microcapsule to the outermost surface of the plate is preferably set to be between 0.005 μm and 5 μm according to the printing field and the material used. When the same material is used, as the thickness from the outer surface of the microcapsule to the outermost surface of the plate increases, the printing durability increases, but the sensitivity decreases. Therefore, in the printing field where high sensitivity is required and printing durability is not so important, the thickness from the outer surface of the microcapsule to the outermost surface of the plate is set to be thin. However, when the thickness of the polymer layer is less than 0.005 μm, the printing durability of the non-image area is unpreferably too low. Also, 5
If the thickness is larger than μm, the sensitivity is lowered, which is not preferable. Further, it is more preferably used in a thickness of 0.01 to 2 μm, and particularly preferably in a range of 0.05 to 1 μm.

The thickness from the outer surface of the microcapsule to the outermost surface of the plate can be measured by a method appropriately selected from known thickness measuring methods depending on the thickness. That is,
When the thickness is small, a method of preparing an ultrathin section and measuring it with a transmission electron microscope or a method of preparing a cross section and measuring with a scanning electron microscope can be used. When the thickness of the layer is large, it can be measured with a contact-type film thickness meter. The thickness can also be measured by a method of specifying the thickness using a calibration curve by using a fluorescent X-ray analysis method or an X-ray photoelectron spectroscopy method. Further, when the hydrophilic and ink-repellent polymer does not flow into the MC layer, the thickness can be calculated from the applied weight of the polymer layer.

In order to make a thermal lithographic original plate according to the present invention, it is only necessary to draw and print a document / image produced and edited by an electronic typesetting machine, a DTP, a word processor, a personal computer or the like using a thermal head and a laser in a thermal mode. The development process is completed without any processing. After printing, the degree of crosslinking in the image area or non-image area can be increased by heating (post curing) at a temperature at which the capsule is not destroyed or by irradiating the entire surface of the plate with actinic rays. If you do the latter,
In the binder polymer of the hydrophilic and ink-repellent polymer layer or the MC layer, the photopolymerization initiator or the photocationic polymerization initiator and the compound having a functional group which proceeds by the reaction are used in combination or the lipophilic component has the functional group. It is necessary to introduce a group. The initiator and the compound having a functional group are described above. For example, "UV / EB curing handbook (raw material)" edited by Kiyomi Kato, "Ultraviolet Curing System", published by Sogo Gijutsu Center (1989); Publication Society (1985)
And the like can be used.

The printing plate obtained as described above can be set on a commercial offset printing press and printed by a usual method. When printing, if necessary, the printing plate can be subjected to a normal etching treatment before printing.

[0071]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described by way of examples.
Explain physically. In addition, especially in the text, the part is described.
Parts are by weight unless otherwise noted. <Production Example 1 of hydrophilic polymer [P-1]> Acrylic acid 3
6.0 g, previously dried with molecular sieves
A mixed solution of 150 g of N, N-dimethylformamide
Bubble dry nitrogen and heat to 60 ° C with stirring
Was. To this solution was added 2,4-azobis (dimethylvaleronite
Ril) (hereinafter abbreviated as ADVN).
And reacted for 2 hours. Continue to dry nitrogen to dry air
2,6-di-t-butylparacresol (hereinafter referred to as
Below, it is abbreviated as BHT. ) Add 0.40g and reach 80 ℃
The temperature was raised and stirring was continued for 4 hours. Then, while continuing to stir
After allowing to cool to 60 ° C, 2-methacryloyloxyethyl
9. Luisocyanate (hereinafter abbreviated as MOI)
0 g and 0.1 g of dibutyltin dilaurate are added for 3 hours
Reacted. After stirring for about 3 hours, use infrared spectroscopy
The characteristic absorption of isocyanate groups
The reaction proceeded. Then carboxy with sodium hydroxide
Partially neutralized 80 equivalents of
Is precipitated, washed well and purified to obtain a hydrophilic polymer [P
-1] (introduction rate of unsaturated group measured by NMR method is 8.2
Equivalent%. Number average molecular weight by GPC: 7.5 × 10^Four,
(Water-kerosene oil-in-water contact angle: 160 degrees or more)
Obtained. <Production example 2 of hydrophilic polymer [P-2]> Acrylic acid 3
A mixed solution of 6.0 g and 150 g of toluene was dried under nitrogen.
The temperature was raised to 60 ° C. with stirring and stirring. This solution
Was added and reacted for 2 hours. Obtained
The polymer precipitate is collected by filtration and washed repeatedly.
-18 g was dissolved in 100 g of purified water.
Partially neutralizes 80 equivalents of carboxyl groups with lithium and hydrophilic
Polymer [P-3] (number average molecular weight by GPC:
6.5 × 10^Four, Water-kerosene oil-in-water contact angle:
160 °). <Production Example 3 of hydrophilic polymer [P-3]> Separaburg
300g of acetone in Lasco, 2-sulfoethylmethac
Charge 21g of acrylic acid and 15.8g of acrylic acid, and add nitrogen
In an atmosphere, heated to 45 ° C and stirred,
0.52 g of AIBN dissolved in the ton in about 30 minutes
It was dropped. After stirring for 6 hours, the polymer produced
Filtration and acetone washing were repeated several times.
It was confirmed that there was almost no residue. Vacuum the polymer
It was dried to obtain a primary polymer (number average molecule by GPC method)
Amount: 16.4 × 10 ^Four. In polymer determined by elemental analysis
Is approximately 33/67 in the above order.
In mole ratio. ).

Next, 10.8 g of the primary polymer was weighed into a separable flask already charged with 133 g of toluene and 0.012 g of BHT, and heated to 90 ° C. while stirring in a stream of dry air. 1.6 g of MOI and 0.03 g of dibutyltin dilaurate were gradually dropped therein. After stirring for about 9 hours, the reaction proceeded until the characteristic absorption of isocyanate groups in infrared spectroscopy was almost negligible. The dispersed polymer was filtered, washed several times with acetone, and dried under vacuum (the introduction ratio of unsaturated groups measured by NMR method was 5.6 equivalent%). The obtained polymer was dissolved in water, and 60 equivalent% of a carboxyl group and a sulfonic acid group was partially neutralized with potassium hydroxide to obtain a hydrophilic polymer [P-3].
(Number average molecular weight before potassium chloride by GPC: 17.
3 × 10 ⁴ , water-kerosene oil-in-water contact angle: 16
0 degrees or more). <Production example 1 of microcapsule containing lipophilic component>
[M-1]> 3,3′-dimethylbiphenyl-4,4 ′
10 g of diisocyanate and 0.5 g of near-infrared absorbing dye (Kayasorb CY-10 manufactured by Nippon Kayaku Co., Ltd.) are dissolved and mixed in 20 g of toluene and 200 g of acetone, and then dried. In this, approximately the same amount of water / ethanol (5.5 / 2.
(Weight ratio 5%) and the alumina ball were added, and the mixture was shaken with a paint shaker for 1 hour to prepare a lipophilic component [M-1] which was pulverized and microencapsulated. The average size of the primary dispersed particles was 3.0 μm. <Production Example 2 of microcapsule containing lipophilic component>
[M-2]> 1.26 g of tolylene diisocyanate 3 mol / trimethylol propane 1 mol adduct (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd., containing 25% by weight of ethyl acetate), near-infrared absorbing dye (Nihon Kagaku) 0.3 g of Kaysorb IR-820B (Yakuhin Co., Ltd.) was uniformly dissolved in 7.2 g of glycidyl methacrylate to prepare an oily component. Next, propylene glycol alginate (Duckloid LF,
2 g of Kibun Food Chemifa Co., Ltd., 0.86 of polyethylene glycol (PEG 400, manufactured by Sanyo Chemical Co., Ltd.)
g was mixed to prepare an aqueous phase. Subsequently, the oily component and the aqueous phase were mixed and emulsified at 6000 rpm at room temperature using a homogenizer, and then reacted at 60 ° C. for 3 hours to obtain microcapsules [M-2] having an average particle size of 1.8 μm. <Production Example 3 of microcapsule containing lipophilic component>
[M-3]> 3,3′-dimethylbiphenyl-4,4 ′
Dissolving 13.2 g of diisocyanate, 5.9 g of 2-hydroxyethyl acrylate and 0.05 g of dibutyltin dilaurate as a catalyst in 80 g of ethyl acetate,
After stirring for 15 minutes, the mixture was reacted at 70 ° C. for 2 hours to synthesize a compound having an acryloyl group and an isocyanate group in the same molecule, and dried under vacuum. The obtained solid is pulverized in a mortar, and the same amount of a water / ethanol (5.5 / 2.5 weight ratio) solution and an alumina ball as the solid are added thereto, and shaken with a paint shaker for 3 hours. Then, a lipophilic component [M-3] which was pulverized and microencapsulated was prepared. The average particle size of the primary dispersion particles was 1.6 μm. <Preparation conditions of support> A polyallylamine (PAA- manufactured by Nitto Boseki Co., Ltd.) was coated on the surface of a PET coated with a urethane-based adhesive.
A mixed solution of 10 parts of 10C, 10 wt% aqueous solution), 0.8 parts of polyethylene glycol diglycidyl ether (n = 9), and 8 parts of acetone was applied to an average thickness of 1 μm, dried at 50 ° C. without curing.

[0073]

Example 1 A dope having the following composition, which had been well dispersed in advance with a paint shaker at room temperature for 30 minutes and then defoamed, was applied on a support on which the above-mentioned polyallylamine-based anchor layer was applied. Hydrophilic polymer: [P-1] (15% solid content): 6.0 parts Microcapsules: [M-1] (20% solid content): 6.0 parts 2,2-dimethoxy-2-phenylacetophenone: 0.1 part Water: 8.0 parts Next, it was air-dried for 30 minutes, dried at 30 ° C. for 3 hours with a drier, and then calendered. Next, an aqueous solution in which 3% by weight of a hydrophilic polymer [P-1] and 0.1% by weight of (2-acryloyloxyethyl) (4-benzoylbenzyl) dimethylammonium bromide were dissolved as a hydrophilic and ink-repellent polymer was prepared. 15 blade coater gap
μm, air-dry for 30 minutes, 30 ℃
Dried for 3 hours. Observation of the cross section of the plate with a scanning electron microscope revealed that the polymer thickness from the outer surface of the microcapsule to the outermost surface of the plate was 0.5 μm on average at 10 points. Then, a chemical lamp (λmax. 365 nm,
The entire surface was irradiated with ultraviolet light at a UV intensity of 5 mW / cm ² ) to obtain a master.

This original was connected to an electronic forme, and a 1W
The printed image was thermally printed by a printing device equipped with a semiconductor laser element, and reacted at 55 ° C. for 30 minutes to obtain a printing plate. This plate was trimmed to a predetermined size, mounted on an offset printing machine (HAMADA 611XL, manufactured by Hamada Printing Machine Co., Ltd., using a hard blanket) and printed on high quality paper (the used ink was BSD offset ink new rubber).
Ink Gold, with etch treatment, and the dampening solution used was an etch solution diluted 50-fold with water. ). Even after 20,000 copies, no stain was obtained, and a stable printed matter was obtained.

[0075]

Example 2 An original plate was prepared in the same manner as in Example 1, except that the hydrophilic and ink-repellent polymer applied on the MC layer was [P-3] and the concentration of the polymer was 5% by weight.
When the cross section of the plate was observed with a scanning electron microscope, the polymer thickness from the outer surface of the microcapsules to the outermost surface of the plate was 0.8 μm on average at 10 points. The original plate was evaluated in the same manner as in Example 1. As a result, a stable printed matter was obtained without any background stain even after 30,000 copies had passed.

[0076]

Example 3 The microcapsules [M-2] and the hydrophilic and ink-repellent polymer coated on the MC layer were [P-
3] An original plate was prepared in the same manner as in Example 1 except that the gap of the blade coater was 10 μm, the concentration of the polymer was 1% by weight, and the entire surface was not exposed by a calendering process or a chemical lamp. The thickness of the hydrophilic and ink-repellent polymer layer determined from the coating weight was 0.1 μm. This original plate was connected to an electronic typesetting device, and the printed image was thermally printed by a printing device equipped with a 1W semiconductor laser element. Then, the entire surface of the plate was irradiated with a high-pressure mercury lamp for 1 minute without going through a development process.
A printing plate was obtained. When this plate was trimmed and printed in the same manner as in Example 1, a stable printed matter was obtained even after passing 20,000 copies.

[0077]

Example 4 Microcapsules [M-3] and hydrophilic and ink-repellent polymers to be coated on the MC layer were [P-
3] A master was prepared in the same manner as in Example 1 except that the gap of the blade coater was 40 μm, the concentration of the polymer was 5% by weight, and the entire surface was not exposed by a chemical lamp. When the cross section of the plate was observed with a scanning electron microscope, the polymer thickness from the outer surface of the microcapsule to the outermost surface of the plate was 2.0 μm on average at 10 points. Thermal head (TPH-2 manufactured by Toshiba) connected to an electronic typesetting machine
93R7) to print a print image with a printing device (plate making device) mounted thereon, and thereafter, a chemical lamp (λmax. 365n)
m, UV intensity; 5 mW / cm ² ), and the entire surface was irradiated with ultraviolet rays to perform plate making without development. This plate was trimmed to a predetermined size, mounted on an offset printing machine (HAMADA 611XL, using a hard blanket, manufactured by Hamada Printing Machinery Co., Ltd.) and printed on high quality paper (the used ink was BSD offset ink New Rubber Black Gold, etch treatment) There was used a dampening solution obtained by diluting the etchant with water 50 times.) However, a stable printed matter was obtained even after passing 30,000 parts.

[0078]

Example 5 A synthetic dope of microcapsule [M-2] was applied on the same support as in Example 1 to prepare an MC layer. Next, a hydrophilic and ink-repellent polymer layer was provided in the same manner as in Example 3 except that the gap of the blade coater was changed to 25 μm, and an original plate was produced in the same manner as in Example 3. When the cross section of the plate was observed with a scanning electron microscope, the polymer thickness from the outer surface of the microcapsule to the outermost surface of the plate was 0.2 μm on average at 10 points. Further, when plate making and printing were performed in the same manner as in Example 3, a stable printed matter was obtained even after 10,000 copies.

[0079]

Example 6 The gap of the blade coater was 5 μm, and the concentration of the hydrophilic and ink-repellent polymer [P-3] was 0.2.
An original plate was prepared in the same manner as in Example 3, except that the amount was changed to% by weight. The thickness of the hydrophilic and ink-repellent polymer layer determined from the coating weight was 0.01 μm. When the original plate was subjected to plate making and printing in the same manner as in Example 3, a stable printed matter was obtained even after 3,000 copies.

[0080]

Example 7 The gap of the blade coater was 50 μm,
When the concentration of the hydrophilic and ink-repellent polymer [P-3] is 10
An original plate was prepared in the same manner as in Example 3, except that the amount was changed to% by weight. The thickness of the hydrophilic and ink-repellent polymer layer determined from the coating weight was 5.5 μm. Example 3
When plate-making printing was performed in the same manner as described above, non-image portions could be printed stably, but the density of the image portions was insufficient for a while after printing.

[0081]

Example 8 The gap of the blade coater was 5 μm, and the concentration of the hydrophilic and ink-repellent polymer [P-3] was 0.0.
An original plate was prepared in the same manner as in Example 3 except that the amount was 8% by weight. The thickness of the hydrophilic and ink-repellent polymer layer determined from the coating weight was 0.003 μm. When this original plate was subjected to plate making and printing in the same manner as in Example 3, stable printed matter was obtained up to about 100 parts.

[0082]

Example 9 Microcapsules M-2 were washed five times with purified water using a centrifugal separator, and then washed with MC as in Example 1.
Layers were made. Next, a hydrophilic and ink-repellent polymer layer was provided in the same manner as in Example 5 to obtain an original plate. When the cross section of the plate was observed with a scanning electron microscope, the polymer thickness from the outer surface of the microcapsule to the outermost surface of the plate was 0.1 μm on average at 10 points. Example 3
Plate making and printing were performed in the same manner as in Example 1. As a result, a stable printed matter of about 6,000 parts was obtained.

[0083]

Comparative Example 1 A dope having the following composition, which had been well dispersed in advance with a paint shaker at room temperature for 30 minutes and then defoamed, was coated on the same support as in Example 1 using a blade coater. Hydrophilic polymer: [P-1] (15% solid content): 8.0 parts Microcapsules: [M-1] (20% solid content): 6.0 parts 2,2-dimethoxy-2-phenylacetophenone: 0.3 part Partially saponified PVA: 0.1 part Surfactant (Nonipol 85 manufactured by Sanyo Chemical Co., Ltd.) 0.2 part Calcium carbonate: 0.8 part Water: 8.0 parts Then, air-dry for 1 minute, and vacuum It was dried in a dryer at 35 ° C. for 3 hours, and then calendered. The average thickness of the polymer from the outer surface of the microcapsule to the outermost surface of the plate determined by section observation using a transmission electron microscope was 0.2 μm on average at 10 points. After that, the chemical lamp (λ
max. The entire surface was irradiated with ultraviolet light at 365 nm, UV intensity; 5 mW / cm ² ) to obtain a master.

This original was connected to an electronic typesetting device, and 1W
The printed image was thermally printed by a printing device equipped with a semiconductor laser element, and reacted at 55 ° C. for 30 minutes to obtain a printing plate. This plate was trimmed to a predetermined size, mounted on an offset printing machine (HAMADA 611XL, manufactured by Hamada Printing Machine Co., Ltd., using a hard blanket) and printed on high quality paper (the used ink was BSD offset ink new rubber).
Ink Gold, with etch treatment, the dampening solution used was a 50-fold dilution of the etchant with water).
Although 10,000 copies were obtained, a great deal of effort was required to study the drying conditions and the composition of the dispersion medium in order to control the thickness of the binder polymer present on the plate surface side of the microcapsules.

[0085]

Comparative Example 2 An original plate was prepared in the same manner as in Example 3 except that the hydrophilic and ink-repellent polymer applied on the MC layer was changed to [P-2]. The thickness of the hydrophilic and ink-repellent polymer layer determined from the coating weight was 0.1 μm. When the original plate was subjected to plate making and printing in the same manner as in Example 3, background stains occurred in the non-image portion from around 1,000 copies.

[0086]

Comparative Example 3 The microcapsules [M-
Instead of using [1], the same amount of wax having an average particle diameter of 1.0 μm having no reactive group is added, the gap of the blade coater is 40 μm, and the concentration of hydrophilic and ink-repellent polymer [P-3] is 1 wt. %, And the same dope composition was prepared, except that it was changed to%, and applied in the same manner as in Example 4 to prepare an original plate. The thickness of the hydrophilic and ink-repellent polymer layer determined from the coating weight was 0.4 μm. This original plate was made and printed in the same manner as in Example 4. As a result, the image portion of the printed material started to be blurred from around 600 copies.

[0087]

According to the production method of the present invention, since the thickness of the hydrophilic and ink-repellent polymer layer present on the outermost surface of the microcapsule can be easily controlled, a non-image portion can be formed stably. A heat-sensitive direct lithographic printing plate having high printing durability and high dimensional accuracy can be easily obtained, which is very useful in industry.

Claims (6)

[Claims] 1. A heat-sensitive lithographic printing plate precursor comprising a microcapsule containing a lipophilic component which is converted into an image area by heat, a hydrophilic and ink-repellent polymer and a support, wherein said hydrophilic and ink-repellent plate is used. The functional polymer has a functional group capable of three-dimensionally cross-linking and a functional group that chemically bonds to the lipophilic component in the microcapsule after the capsule is broken, and the lipophilic component in the microcapsule is In the method for producing a heat-sensitive direct lithographic original plate having a functional group chemically bonded to the hydrophilic and ink-repellent polymer after breaking, an MC layer containing at least the microcapsules is provided on a support, and then the hydrophilic layer is formed. A method for producing a heat-sensitive direct lithographic original plate, comprising providing an ink-repellent polymer layer. 2. The method according to claim 1, wherein after forming the hydrophilic and ink-repellent polymer layer, the polymer layer is three-dimensionally cross-linked before image drawing. 3. The method according to claim 1, wherein the MC layer contains a binder polymer that binds the microcapsules.
Or the method for producing a heat-sensitive lithographic original plate according to item 2. 4. The method according to claim 3, wherein the binder polymer of the MC layer is a hydrophilic polymer. 5. The method for producing a heat-sensitive direct lithographic original plate according to claim 3, wherein the binder polymer of the MC layer contains a functional group capable of three-dimensionally crosslinking. 6. The binder polymer of the MC layer has a functional group that chemically bonds to the lipophilic component in the microcapsules of the MC layer after the capsule is broken, and the lipophilic component in the microcapsule is used after the capsule is broken. The method for producing a heat-sensitive direct lithographic original plate according to claim 3, which has a functional group chemically bonded to the binder polymer.