JP2000211262A - Heat-sensitive lithographic printing original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithographic printing plate of a high printing durability and a high dimensional precision, and at the same time, supply a lithographic printing original plate by which a printed article of a clear image without greasing can be obtained, at a low cost by making a micro capsule outer shell contain an additional polymerizing functional group. SOLUTION: In this heat-sensitive lithographic printing original plate having a recording layer containing a microcapsulated lipophilic component, which is converted into an image section by heat, and a hydrophilic binder polymer, and a supporting body; an additional polymerizing functional group is provided on the wall material of the microcapsule. Then, the addition polymerizing functional group is formed by a carbon-carbon double bond, and the carbon-carbon double bond is formed of at least one kind of an acrylic group, a methacrylic group and an allyl group, and at the same time, the additional polymerizing functional group is made either one of an epoxy group and a glycidyl group. Also, the wall material of the microcapsulated lipophilic component is formed of a urea-urethane structure. In addition, as a material for the urethane-urea wall material, an isocyanate compound of three functions or more, is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct thermal lithographic printing plate precursor for offset printing which does not require development and has excellent printing durability, and a method for producing the same.

[0002]

2. Description of the Related Art With the spread of computers, various plate making methods have been proposed along with the plate material composition. From a practical point of view, a method of producing a positive or negative film from a block and baking it onto a lithographic printing plate is generally performed, but an electrophotographic plate or a silver halide photographic plate in which plate making is performed directly from the plate without passing through the film. , Or electronic typesetting, DTP
A so-called computer-to-plate (CTP) type lithographic plate that allows printing and editing of printed image information edited and produced by (Desktop Publication) directly on a plate material with a laser or thermal head without visualizing it. Lumber is coming up. In particular, CTP type plate materials can be rationalized and shortened in plate making process, and material cost can be reduced. Therefore, CTP type plate material is greatly expected in fields such as newspaper production where CTS has been completed and commercial printing where pre-press process is digitized. I have.

[0003] As such a CTP plate material, a photosensitive type, a heat-sensitive type or a plate type made with electric energy is known. Plates made of photosensitive type or plate made with electric energy are not only more expensive than conventional PS plates, but also have large and expensive manufacturing equipment. Has not been reached. In addition, they also have the problem of disposal of the developer.

Some heat-sensitive plate materials have been developed for light printing applications such as in-house printing. JP-A-63-
JP-A-64747 and JP-A-1-113290 disclose a method in which a hot-melt resin and a thermoplastic resin dispersed in a heat-sensitive layer provided on a support are melted by thermal printing, and the heated portion is changed from hydrophilic to lipophilic. Are disclosed in U.S. Pat. Nos. 4,034,183 and 4,063,949. A plate material for irradiating a hydrophilic polymer provided on a support with a laser to remove a hydrophilic group and convert it to lipophilicity is disclosed. It has been disclosed. However, these plate materials have problems that the non-image area is stained due to the reception of the ink by the hot-melt substance present on the plate surface, the printing durability is insufficient, and the degree of freedom in plate material design is low. was there.

JP-A-3-108588, JP-A-5-108588
JP-A-8575 discloses a plate material in which a heat-sensitive recording layer comprising a microencapsulated heat-fusible substance and a binder resin is provided on a support, and a heating portion is changed to lipophilic. However, in these plate materials, the image formed from the microencapsulated hot-melt material is brittle, and the printing durability is not satisfactory. On the other hand, JP-A-62-164596 and JP-A-62-164049 disclose a lithographic printing plate precursor having a recording layer comprising a blocked isocyanate together with an active hydrogen-containing binder polymer on a support having a hydrophilic surface, and A method is disclosed. However, this printing plate requires a developing step of removing a non-printed portion after printing.

Further, as one of the direct type lithographic printing materials, there is a direct drawing type lithographic printing material in which an image portion is formed on the surface of a hydrophilic layer by an external means such as ink jet or toner transfer.
Japanese Patent Application Laid-Open No. Sho 62-1587 discloses a plate material in which a microencapsulated non-reactive heat-fusible substance is applied, and a toner receiving layer is formed by heating and printing. However, a printing plate is formed only after lipophilic toner or the like is fixed to the formed toner receiving layer, and an image portion is not formed after printing. As described above, the conventional plate material for heat-sensitive lithographic printing has poor printing durability or poor oleophilicity, and thus has been limited to applications such as light printing. Further, in some plate making processes, a developing process was required.

Therefore, JP-A-07-01849, JP-A-07-01850, JP-A-10-6468, and JP-A-10-114168 disclose reactive microcapsules which convert to an image by heat. A printing plate dispersed in a crosslinked hydrophilic binder is described. These plate materials are direct plates in the thermal mode. Near-infrared laser is used as applied energy, so they can be handled in a normal room. Also, development is not required, greatly simplifying the plate making process. There are advantages that can be done. However, in the plate materials described in these, the printing durability of the image area may be low depending on the number of prints.

[0008]

As described above, the prior art has a problem in terms of plate performance, plate making equipment, plate making workability, or the cost of plate materials, plate making, and equipment, and has a problem in implementation on a commercial level. . In addition, even in a development-less direct lithographic plate using a reactive microcapsule and a hydrophilic binder polymer, the printing durability of the image portion with a large number of prints may not be sufficient, and a balance is required in plate configuration design. Is difficult.

An object of the present invention is to solve these problems of the conventional direct offset printing plate. That is, an object of the present invention is to provide a lithographic printing plate precursor that can obtain a lithographic printing plate with high printing durability and high dimensional accuracy, and that can obtain a printed image with a clear image without background contamination at a low price. . Furthermore, the present invention also provides a lithographic printing plate precursor and a plate making method which can perform plate making without using a dedicated large-scale and expensive plate making machine without a developing step requiring waste treatment such as a developer in the plate making step. Is the purpose.

[0010]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems. However, if the outer shell of the microcapsule contains an addition-polymerizable functional group, high image printing durability can be obtained. It was found that they were expressed, leading to the present invention. That is, the present invention is as follows.

The heat-sensitive lithographic printing plate precursor according to claim 1 is a heat-sensitive lithographic printing plate having a recording layer containing a microencapsulated lipophilic component converted into an image area by heat and a hydrophilic binder polymer, and a support. The printing plate precursor is characterized in that the wall material of the microcapsules has an addition-polymerizable functional group. The lithographic printing plate precursor according to claim 2 is:
The heat-sensitive lithographic printing plate precursor according to claim 1, wherein the addition-polymerizable functional group is a carbon-carbon double bond.

The heat-sensitive lithographic printing plate precursor according to claim 3 is characterized in that, in the heat-sensitive lithographic printing plate precursor according to claim 2, the carbon-carbon double bond is at least one of an acryl group, a methacryl group and an allyl group. . The heat-sensitive lithographic printing plate precursor according to claim 4 is characterized in that, in the heat-sensitive lithographic printing plate precursor according to claim 1, the addition-polymerizable functional group is either an epoxy group or a glycidyl group.

The heat-sensitive lithographic printing plate precursor according to claim 5, wherein the microencapsulated wall material of the lipophilic component has a urea-urethane structure. The heat-sensitive lithographic printing plate precursor according to claim 6 is characterized in that, in the heat-sensitive lithographic printing plate precursor according to claim 5, a tri- or more functional isocyanate compound is used as a raw material of the urethane-urea wall material.

Although the mechanism for improving the printing durability of the image according to the present invention is not clear, when the outer wall of the microcapsule has an addition-polymerizable functional group, the inclusion of the microcapsule in the image area converted to the image area by heat is increased. It is presumed that not only the outer wall material is polymerized but also a strong image portion is formed to realize high image printing durability.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The heat-sensitive lithographic printing plate precursor of the present invention can be roughly divided into a recording layer (1) and a support (2). First, the recording layer (1) will be described. The recording layer (1) is composed of a hydrophilic binder polymer (a) and a microencapsulated lipophilic component (b).

The recording layer (1) comprises a hydrophilic binder polymer (a), a microencapsulated lipophilic component (b), and other additives. The hydrophilic binder polymer (a) in the present invention is a polymer composed of carbon-carbon bonds, or oxygen, nitrogen, sulfur,
Polymers composed of carbon atoms or carbon-carbon bonds bonded by at least one of heteroatoms composed of phosphorus, that is, poly (meth) acrylate, polyoxyalkylene, polyurethane, epoxy ring-opening addition polymerization, A (meth) acrylic acid-based, poly (meth) acrylamide-based, polyester-based, polyamide-based, polyamine-based, polyvinyl-based, polysaccharide-based or composite polymer thereof is used as a basic skeleton, and a hydrophilic functional group is contained in the structure. It is a polymer containing at least one kind.

The hydrophilic functional group referred to in the present invention means a carboxyl group, a phosphoric acid group, a sulfonic acid group, an amide group, an amino group and salts thereof, a hydroxyl group and a polyoxyalkylene group. Hydrophilic functional group-containing hydrophilic binder polymer (a)
The ratio in the medium may be appropriately determined experimentally by any of the methods described below for each sample according to the type of the basic skeleton and the type of the hydrophilic functional group used. That is, the hydrophilicity of the hydrophilic binder polymer (a) of the present invention can be determined by forming a heat-sensitive lithographic printing plate precursor containing the hydrophilic binder polymer (a) on a support, and applying the method described in the Examples. Preparation and printing tests are performed to evaluate whether ink has adhered to the printing paper or the difference in reflection density between the non-image areas before and after printing (for example, reflection density meter DM400 manufactured by Dainippon Screen Mfg. Co., Ltd.). Or oil-in-water contact angle measurement using water-kerosene (for example,
Evaluate whether or not kerosene adheres to the sample with a contact angle meter manufactured by Kyowa Interface Science, Model CA-A).

In the case of evaluation by the former method, it is observed with the naked eye, and if ink stains are not recognized, it is acceptable, if it is recognized, it is not, or the reflection density difference of the non-image part before and after printing is less than 0.01. Is acceptable and 0.01 or more is not acceptable. 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.

A functional group other than the above-mentioned hydrophilic group may be bonded to the hydrophilic binder polymer (a) as long as the object of the present invention is not impaired. In particular, it is preferred from the viewpoint of image printing durability that the hydrophilic binder polymer (a) has a functional group capable of chemically bonding to a lipophilic component described later. Further, it is more preferable that the hydrophilic binder polymer (a) has a Lewis base moiety containing nitrogen, oxygen or sulfur, because it can be cured via a polyvalent metal atom or a polyvalent metal compound.

The hydrophilic binder polymer (a) of the present invention
May include one or more of the following three-dimensional crosslinked structures. That is, the hydrophilic binder polymer (a) having a functional group such as a carboxyl group, an amino group or a salt thereof, a hydroxyl group and an epoxy group utilizes these functional groups to form a vinyl group, an allyl group, a (meth) acryl group. And ethylene-polymerizable unsaturated groups such as cinnamoyl, cinnamylidene, cyanosinnamylidene, p-
An unsaturated group-containing polymer into which a ring-forming group such as a phenylenediacrylate group has been introduced can be obtained. If necessary, a monofunctional, polyfunctional monomer capable of copolymerizing with the unsaturated group, a polymerization initiator and an inorganic filler described below, and a lubricant described below are added as necessary, and dissolved in an appropriate solvent. , Prepare a dope. This is coated on a support and dried or three-dimensionally cross-linked after drying.

The hydrophilic binder polymer (a) containing an active hydrogen such as a hydroxyl group, an amino group and a carboxyl group is added to an active hydrogen-free solvent together with an isocyanate compound or a blocked polyisocyanate compound and other components described below. Is prepared, coated on a support, and reacted after drying or also as drying to form a three-dimensional crosslink.

As the copolymerization component of the hydrophilic binder polymer (a), a monomer having a glycidyl group such as glycidyl (meth) acrylate, a carboxyl group such as (meth) acrylic acid or an amino group can be used. The hydrophilic binder polymer (a) having a glycidyl group includes 1,2-ethanedicarboxylic acid as a crosslinking agent,
Α, ω-alkane or alkenedicarboxylic acid such as adipic acid, polycarboxylic acid such as 1,2,3-propanetricarboxylic acid, trimellitic acid, 1,2-ethanediamine, diethylenediamine, diethylenetriamine,
Polyamine compounds such as α, ω-bis- (3-aminopropyl) -polyethylene glycol ether, oligoalkylenes or polyalkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol and tetraethylene glycol, trimethylolpropane, glycerin, pentaerythritol Sorbitol and the like, and three-dimensional cross-linking can be performed by utilizing a ring opening reaction with these.

The hydrophilic binder polymer (a) having a carboxyl group or an amino group may be used as a crosslinking agent such as ethylene or propylene glycol diglycidyl ether, polyethylene or polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6- Three-dimensional crosslinking can be performed using an epoxy ring-opening reaction using a polyepoxy compound such as hexanediol diglycidyl ether or trimethylolpropane triglycidyl ether.

When the hydrophilic binder polymer (a) contains a polysaccharide such as a cellulose derivative, polyvinyl alcohol or a partially saponified product thereof, a glycidol homo- or copolymer, or a hydroxyl group contained in these, the above-mentioned hydroxyl group is used. A functional group capable of undergoing a crosslinking reaction is introduced, and three-dimensional crosslinking can be performed by the above-described method. Polyol having a hydroxyl group at the polymer end such as polyoxyethylene glycol or polyamine having an amino group at the polymer end and 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, etc. The hydrophilic binder polymer (a) is obtained by introducing an ethylene addition-polymerizable unsaturated group or a ring-forming group into a hydrophilic polyurethane precursor synthesized from the above-mentioned polyisocyanate, and can be three-dimensionally crosslinked by the method described above.

When the synthesized hydrophilic polyurethane precursor has an isocyanate group terminal, glycerol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-mono Methylol (meth) acrylamide, N-dimethylol (meth) acrylamide,
It reacts with a compound having active hydrogen such as (meth) acrylic acid, cinnamic acid and cinnamic alcohol to form a three-dimensional crosslink.
When the hydrophilic polyurethane precursor has a hydroxyl group or amino group terminal, the precursor is reacted with (meth) acrylic acid, glycidyl (meth) acrylate, 2-isocyanatoethyl (meth) acrylate, or the like to perform three-dimensional crosslinking.

When the hydrophilic binder polymer (a) is a polymer formed from a polybasic acid and a polyol or a polybasic acid and a polyamine, they are applied to a support and then three-dimensionally crosslinked by heating. When the hydrophilic binder polymer (a) is casein, glue, gelatin or the like, these water-soluble colloid-forming compounds may be three-dimensionally cross-linked by heating to form a network structure.

Furthermore, hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate and vinyl alcohol, homo- or copolymers synthesized from allylamine, partially saponified polyvinyl alcohol, polysaccharides such as cellulose derivatives, and glycidol homo- or copolymers A hydrophilic polymer having two or more acid anhydride groups in one molecule with a hydrophilic polymer having an amino group or an amino group to form a three-dimensionally crosslinked hydrophilic binder polymer (a). . The polybasic acid anhydride used in this reaction includes ethylene glycol-bis-anhydro-trimellitate, glycerol-tris-anhydrotrimellitate, 1,3,3a, 4,5,9b-
Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] furan-1,
Examples thereof include 3-dione, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride and the like.

When the hydrophilic binder polymer (a) is formed from a polyurethane having an isocyanate group at a terminal and an active hydrogen-containing compound such as a polyamine or a polyol, these compounds and other components described below are mixed with a solvent. After dissolving or dispersing in the support and applying it to the support to remove the solvent, curing can be carried out at a temperature at which the microcapsules are not broken to effect three-dimensional crosslinking. In this case, hydrophilicity may be imparted by introducing a hydrophilic functional group into either or both segments of polyurethane or the active hydrogen-containing compound, or a side chain. The segment and the functional group that express hydrophilicity may be appropriately selected from the above description.

The isocyanate compound used in the present invention includes 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, Bicycloheptane triisocyanate can be exemplified.

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., according to sodium acid sulfite, aromatic secondary amine, tertiary alcohol, amide, phenol, lactam,
Blocking can be performed using a heterocyclic compound, ketoxime, or the like. Among them, preferred is a low isocyanate regeneration temperature, such as diethyl malonate and ethyl acetoacetate.

An addition-polymerizable unsaturated group may be introduced into any of the above-mentioned unblocked or blocked polyisocyanates and used for strengthening crosslinking and reacting with lipophilic components. In the case where the above-mentioned three-dimensional crosslinking reaction using the ethylene addition-polymerizable unsaturated group is performed in the hydrophilic binder polymer (a) of the present invention, a known photopolymerization initiator or thermal polymerization initiator is added to the recording layer. Is preferable in terms of reaction efficiency.

The photoradical polymerization initiator used in the present invention includes benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, Michler's ketone, xanthone, thioxanthone,
Chloroxanthone, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 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-thioxanthon-9-one-mesochloride, 1
-Phenyl-1,2-propanedione-2- (O-benzoyl) oxime, thiophenol, 2-benzothiazolethiol, 2-benzoxazolethiol, 2-
Benzimidazole thiol, diphenyl sulfide,
Decylphenyl sulfide, di-n-butyl disulfide, dibenzyl sulfide, dibenzoyl disulfide, diacetyl disulfide, dibornyl disulfide dimethoxyxanthogen disulfide, tetramethylthiuram monosulfide, tetramethylthiuram tetrasulfide, benzyldimethyldithiocarbamate quinoxaline, 1, Examples thereof include 3-dioxolan and N-laurylpyridinium.

From these, those which have absorption in the wavelength region of the light source used in the manufacturing process and which dissolve or disperse in the solvent used when preparing the dope may be appropriately selected.
Usually, those that dissolve in the solvent used are preferred because of their high reaction efficiency. As the cationic photopolymerization initiator used in the present invention, aromatic diazonium salt, aromatic iodonium salt,
And aromatic sulfonium salts. When this initiator is used, an epoxy group can also be used as a cross-linking reactive species. In this case, the above-mentioned epoxy group-containing compound is a crosslinking agent or
It may be used as a hydrophilic binder polymer or an epoxy group may be introduced into the hydrophilic binder polymer.

When three-dimensionally cross-linking is carried out by a photodimerization reaction, various sensitizers generally well known in the reaction, such as 2-nitrofluorene and 5-nitroacenaphthene, can be used. In addition to the above, Katsumi Tokumaru et al., "Sensitizers", Chapter 2,
Chapter 4, Kodansha (1987), Kiyomi Kato, "Ultraviolet Curing System", published by the General Technology Center, pp. 62-147 (19)
89), Fine Chemicals, Vol. 20 No4, 1
6 (1991) can also be used.

The polymerization initiator can be used in an amount of 0.01% to 20% by weight based on the binder polymer before crosslinking. If the amount is less than 0.01% by weight, the effect of the initiator is not exhibited. If the amount is more than 20% by weight, self-absorption of the actinic ray by the initiator makes it difficult for light to reach the inside and exhibits a desired printing durability. May not be able to do so. Practically, in the range of 0.1 to 10% by weight, it is preferable to determine in accordance with the composition by the balance between the effect of the initiator and the background stain in the non-image area.

As the irradiation light source, known light sources such as a metal halide lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and a chemical lamp can be used. When heat from the irradiation light source may cause capsule destruction, it is necessary to perform irradiation while cooling.
As the thermal polymerization initiator used in the present invention, benzoyl peroxide, peroxides such as 2,2-azobisisobutylnitrile, persulfate-sodium bisulfite, azo compounds,
Known ones such as redox initiators can be used. In use, the reaction must be performed at a temperature lower than the temperature at which the microcapsules are broken. The amount of the thermal polymerization initiator used is preferably in the range of 0.01 to 10% by weight based on the components excluding the dope solvent. 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. Considering the effect and handling, preferably
0.1 to 5% by weight.

The hydrophilic binder polymer (a) of the present invention
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. The crosslinking rate, i.e. the molecular weight between crosslinks, is usually
It is set in the range of 500 to 50,000. If it is smaller than 500, it tends to be brittle, and the printing durability is impaired. Considering the balance between both printing durability and hydrophilicity, it is preferably about 800 to 30,000, and more preferably about 1,000 to 30,000.
It is preferably about 10,000.

The hydrophilic binder polymer (a) is defined as described above, and among them, (meth) acrylic acid,
Its alkali metal and amine salts, itaconic acid, its alkali metal and amine salts, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-
Monomethylol (meth) acrylamide, N-dimethylol (meth) acrylamide, allylamine and its hydrohalide salt, 3-vinylpropionic acid, its alkali metal salts and amine salts, vinylsulfonic acid, its alkali metal salts and amine salts, 2-sulfoethyl (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate, allylamine and its hydrohalic acid A homo- or copolymer synthesized using at least one hydrophilic monomer having a hydrophilic group, such as a salt, is suitable as the hydrophilic binder polymer (a) in the present invention. The number average molecular weight of the hydrophilic binder polymer before crosslinking is preferably 1,000 to 2,000,000, more preferably 5000 to 1,000,000. If the molecular weight is too low, the strength of the recording layer will be insufficient and the printing durability will decrease, which is not preferable. If the molecular weight is too high, the viscosity of the solution will increase and it will be difficult to form a film on the support (2). Not preferred.

Next, the microencapsulated lipophilic component (b) will be described. The microencapsulated lipophilic component (b) in the present invention comprises an outer shell layer having an addition-polymerizable functional group and an inclusion containing the lipophilic component. The microcapsules form an image area by destroying the form of the first capsules due to heat during printing. Destruction of the capsule shape means that the density is increased by, for example, lipophilic components being released due to expansion, compression, melting, or chemical decomposition of the capsule wall, being exposed on the outermost surface of the recording layer, or expanding the capsule wall material. In some cases, the lipophilic component decreases and is released through the outer shell layer.

The addition-polymerizable functional group in the present invention refers to a functional group that undergoes an addition polymerization reaction by either an ionic reaction or a radical reaction. For example, an acrylic group, a methacryl group, an allyl group, a functional group having a carbon-carbon double bond such as a vinyl group, an epoxy group glycidyl group, dioxane,
Examples include a functional group using a ring-opening addition polymerization reaction derived from a cyclic ether such as tetrahydrofuran. From the viewpoint of securing a sufficient degree of polymerization, the number of the addition-polymerizable functional groups is preferably 1% or more based on the repeating units of the outer wall structure of the microcapsule. The upper limit is not particularly limited, but if it is more than 200%, it may become brittle when converted to an image area. Therefore, the upper limit is more preferably 200% or less.

A method of microencapsulating a lipophilic component is described in, for example, “New Technology of Microencapsulation and Its Application Development / Application Examples”, edited by Management Development Center, Management Education Department, published by Management Development Center Publishing Division (1978). According to known methods. For example, at the interface between two liquids that do not dissolve each other, the reactant added to each liquid in advance is polycondensed to form a polymer film that is insoluble in both solvents, an interfacial polymerization method that forms a capsule film, a core material, In-situ to supply reactants only from either the inside or outside of the core material and form a polymer wall around the core material
The method can be performed by a complex coacervate method in which a hydrophilic polymer is phase-separated on the surface of a hydrophobic substance dispersed in a hydrophilic polymer solution to form a capsule membrane, a phase separation method from an organic solution system, or the like. Among them, the interfacial polymerization method and the in-situ method are preferred because relatively many core substances can be easily encapsulated.

For example, when synthesizing a urethane-urea wall by an interfacial polymerization method using a continuous layer as water and a dispersion layer as an oily component, a compound such as a polyhydroxy compound or polyamine having active hydrogen is dissolved in the continuous layer. The microcapsule dispersion can be obtained by dissolving the polyisocyanate compound and the lipophilic core substance in the mixture, and allowing the emulsification and reaction to proceed under appropriate conditions. Specific examples of the compound having active hydrogen include 1,2-ethanediamine,
Diethylenediamine, diethylenetriamine, α, ω-
Polyamine compounds such as bis- (3-aminopropyl) -polyethylene glycol ether; oligoalkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol, and tetraethylene glycol; polyethylene glycol; polyalkylene glycols such as EO / PO copolymer; Examples include polyhydroxy compounds such as methylolpropane, glycerin, pentaerythritol, and sorbitol.

As the polyisocyanate compound,
2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthalenedi isocyanate, tolidine diisocyanate, 1,6-hexamethylene diisocyanate, Examples include isophorone diisocyanate, xylylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, bicycloheptane triisocyanate, trimethylolpropane tolylene diisocyanate adduct, and polymethylene polyphenyl polyisocyanate.

In the in-situ method useful for forming a wall material by polymerizing polyurethane in the oil phase, the polyisocyanate compound and the polyhydroxy compound are dissolved in the oil phase at the same time. This solution is emulsified and dispersed in an aqueous protective colloid solution, and if necessary, the temperature is raised and reacted to form a polyurethane wall material having an addition-polymerizable functional group. Examples of the polyhydroxy compound dissolved in the oil phase include polyoxypropylene glycol, polyoxybutylene glycol, and copolymers of these with other glycols, in addition to the polyhydroxy compound.

The material forming such an outer wall may be the lipophilic component itself, or the capsule outer wall may be formed of a material different from the lipophilic component. Further, the form of the lipophilic component in the produced capsule may be different from the raw material state, for example, a gel in which the raw material state is liquid, but can be flowed by heat by printing during synthesis. State, or highly viscous, or solid,
Conversely, what was solid may become liquid during synthesis.

The method for modifying the microcapsule wall material synthesized as described above with an addition-polymerizable functional group is as follows. The addition-polymerizable functional group may be previously bonded to the outer wall raw material and then introduced by forming a wall material, or the wall material may be formed first, and then the surface may be modified by post-treatment. Further, an addition polymerizable functional group may be introduced simultaneously with the formation of the wall material. In particular, it is particularly preferable to introduce the addition-polymerizable functional group into the outer wall material in advance by a method in which the amount of the addition-polymerizable functional group introduced can be easily controlled according to the purpose.

For example, when the urea-urethane wall is formed by the interfacial polymerization method, a part or all of the above-mentioned compounds having active hydrogen, such as a polyhydroxy compound and a polyamine, or a part or all of the polyisocyanate compound, By using an addition-polymerizable functional group-containing compound, an addition-polymerizable functional group can be introduced into the outer wall of the capsule.

D The carbon-carbon double bond-containing isocyanate compound includes an isocyanate compound containing any of an acryl group, a methacryl group, and an allyl group. More specifically, (meth) acryloyloxyethyl There are (meth) acryloyloxyalkyl isocyanate such as isocyanate and (meth) acryloyloxypropyl isocyanate, (meth) acryl isocyanate, allyl isocyanate and the like. Among them, (meth) acryloyloxyalkyl isocyanate and allyl isocyanate are preferred from the viewpoint of stability and workability. Further, in addition to the above compounds, the carbon-carbon double bond-containing polyhydroxy compound and the polyisocyanate compound may be the same as the carbon-carbon double bond-containing isocyanate compound in the ratio of hydroxyl group equivalent / isocyanate group equivalent <1. Can also be exemplified. In particular, when a isocyanate compound having four or more functions such as polymethylene polyphenyl polyisocyanate is modified with a polyhydroxy compound containing a carbon-carbon double bond, a certain degree of polymerization and a certain degree of crosslinking are ensured, and a large amount of addition polymerization is performed. This is particularly preferable because a functional functional group can be introduced.

Examples of the active hydrogen-containing compound having a carbon-carbon double bond include, for example, glycerol mono (meth)
Acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Hydroxyalkyl (meth) acrylates such as 2-hydroxybutyl (meth) acrylate, oligoethylene glycol mono (meth) acrylates such as di, tri, tetra, etc., polyethylene glycol mono (meth) acrylate, pentaerythritol di or tri (meth) acrylate And adducts of diglycidyl etherified glycol compounds such as ethylene and diethylene with (meth) acrylic acid.

When synthesizing microcapsules by the in-situ method, the polyhydroxy compound and the isocyanate compound containing a carbon-carbon double bond are previously reacted in a ratio of hydroxyl group equivalent / isocyanate group equivalent> 1. Compounds obtained by the above can also be used. Specifically, hydroxyalkyl (meth) such as glycerol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate
Oligoethylene glycol mono (meth) acrylates such as acrylate, di, tri, tetra, etc., polyethylene glycol mono (meth) acrylate, oligopropylene glycol mono (meth) acrylates such as di, tri, tetra, etc., polypropylene glycol (meth) acrylate,
2-hydroxy-3-phenoxypropyl (meth) acrylate, pentaerythritol di or tri (meth)
Acrylate: Addition of an adduct of diglycidyl etherified product of a glycol compound such as ethylene, diethylene, propylene, tripropylene, neopentyl, 1,6-hexane, hydrogenated bisphenol A and (meth) acrylic acid to the above-mentioned isocyanate compound Examples of such compounds are given below.

As a method for introducing an addition-polymerizable functional group derived from a cyclic ether, a glycidyl-containing isocyanate compound obtained by reacting glycidol with the above-mentioned isocyanate compound is converted into a carbon-carbon double bond-containing isocyanate compound. Examples of the method include a method in which glycidol itself is used instead of the hydroxy compound having a carbon-carbon double bond instead. Examples of the compound having a cyclic ether and a hydroxyl group other than glycidol include hydroxyfuran, hydroxymethylfuran, hydroxyoxetane, and hydroxymethyloxetane.

When a monohydroxy or monoisocyanate compound containing a carbon-carbon double bond or a monohydroxy compound containing a cyclic ether is used, if the mechanical strength of the microcapsule wall is reduced, trifunctional or higher functional polyhydroxy compound may be used. It is preferable to use a compound or a polyisocyanate compound in combination to reinforce the strength of the shell-forming polymer and maintain it at a predetermined level. The outer shell structure is not particularly limited as long as it has the strength to hold the inclusions, but a structure excellent in abrasion resistance is preferable because shearing is repeatedly applied during printing. Polyurethane, polyurea, and poly (urethane-urea) are particularly preferable because they have excellent abrasion resistance and are relatively easy to synthesize.

The lipophilic component in the present invention includes phenyl isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and 3,3'-dimethylbiphenyl-4,4 '-Diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, bicycloheptane triisocyanate, triden diisocyanate, polymethylene -Isocyanates such as polyphenylisocyanate and polymeric-polyisocyanate; trimethylolpropane and 1,6-hexanediisocyanate 1 pair of bets or 2,4-tolylene diisocyanate such above diisocyanates 3
Isocyanate compounds such as polyisocyanates such as mol adducts, oligomers and polymers of 2-isocyanatoethyl (meth) acrylate; 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, glycidyl methacrylate, methoxytriethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate , Methoxypolyethylene glycol (meth) acrylate (PEG number average molecular weight 40
0), methoxypolyethylene glycol (meth) acrylate (number average molecular weight of PEG 1000), butoxyethyl (meth) acrylate, phenoxyethyl (meth)
Acrylate, ru (meth) acrylate, phenoxyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, diethylene glycol di (meth) acrylate, Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate (PEG number average molecular weight 40
0), polyethylene glycol di (meth) acrylate (number average molecular weight of PEG 600), polyethylene glycol di (meth) acrylate (number average molecular weight of PEG 1)
000), polypropylene glycol di (meth) acrylate (PPG number average molecular weight 400), 2,2-bis [4- (methacryloyloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloyloxy.
Diethoxy) phenyl] propane, 2,2-bis [4-
(Methacryloyloxy-polyethoxy) phenyl] propane and its acrylate, β- (meth) acryloyloxyethyl hydrogen phthalate, β-
(Meth) acryloyloxyethyl hydrogen succinate, polyethylene and 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, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (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 and its methacrylic form, glycerin mono and di (meth)
Acrylates, tris (2-acryloyloxyethyl) isocyanurate and methacrylic bodies thereof, polyfunctional (meth) acrylic monomers such as 2-isocyanatoethyl (meth) acrylate, combinations of these with monofunctional (meth) acrylates, Is a combination with the above-mentioned (meth) acrylate monomer containing a hydrophilic group; N-phenylmaleimide, N- (meth) acryloxysuccinimide, N-vinylcarbazole, divinylethylene urea, divinylpropylene urea, triallyl isocyanate Polyfunctional allyl compounds such as nurate; combinations of these with monofunctional allyl compounds; further, hydroxyl groups, carboxyl groups,
Liquid rubbers such as 1,2-polybutadiene, 1,4-polybutadiene, water-added 1,2-polybutadiene and isoprene containing reactive groups such as amino groups, vinyl groups, thiol groups, and epoxy groups at both ends of the polymer molecule; Various telechelic polymers such as urethane (meth) acrylate;
Carbon-carbon unsaturated group, hydroxyl group, carboxyl group, amino group, epoxy group-containing reactive wax; propylene glycol-diglycidyl ether, tripropylene glycol-diglycidyl ether, polypropylene glycol-diglycidyl ether, neopentyl glycol-diglycidyl Polyfunctional epoxy compounds such as ether, trimethylolpropane-triglycidyl ether and hydrogenated bisphenol A-diglycidyl ether can be used.

Further, known (meth) acrylic copolymers, urethane acrylates, and diazo resins before crosslinking which are used as image components of existing PS plates can also be used. In addition, synthetic and natural resins include polyamide, polyester, acrylate, methacrylate, acrylonitrile, polyurethane, polyvinylidene chloride, polyvinyl chloride, polyfluoroethylene, polypropylene, and polyethylene. , Polystyrene, polybutadiene, natural rubber, and silicone polymers such as silicone, silicone acryl, silicone epoxy, silicone alkyd, and silicone urethane. If necessary, a plurality of types may be used.

The lipophilic component may be solid or liquid at room temperature. Examples of the polyisocyanate compound which is solid at room temperature include triden diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene diisocyanate, polymethylene-polyphenyl isocyanate, polymeric-polyisocyanate, and the like. The microcapsule inclusion may contain a polymerization initiator, a polymerization inhibitor, a coloring matter, a light-to-heat conversion material, and other types of additives in a range that does not impair the effects of the present invention, in addition to the lipophilic components described above. Good. For example, polymerization of an addition polymerizable functional group on the outer wall,
Ethylene addition polymerizable monomer contained in the lipophilic component,
A thermal polymerization initiator can be used for the purpose of accelerating the polymerization of the double bond reaction of the oligomer. The thermal polymerization initiator is 50
It is preferable that it is stable even when stored at a temperature of 60 ° C. or less.
It is more preferable that the content be stable below.

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-butylperoxylau And peroxides such as t-butylperoxyisopropyl carbonate, t-hexylperoxybenzoate, t-butylperoxybenzoate and t-butylperoxyacetate. As a method of adding the thermal polymerization initiator, the initiator may be microencapsulated together with the lipophilic substance, or the initiator itself may be microencapsulated and used in the form of a capsule-in-capsule in the microcapsule of the lipophilic component. Alternatively, it may be dispersed in the recording layer as it is. 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 the hydrophilic binder polymer.

The outer surface of the capsule is not particularly limited as long as the non-image portion does not stain when printed in a state where the microcapsules are contained in the hydrophilic layer.
It is preferably hydrophilic. The microcapsule size is 10 μm or less on average, and 5 μm on average for applications with high resolution.
m or less is preferable. If the ratio of the lipophilic component to the whole capsule is too low, the efficiency of image formation decreases, so that the average of the lipophilic component is 0.
It is preferably at least 01 μm.

In the recording layer (1) of the present invention, the hydrophilic binder polymer (a) contains a Lewis base moiety,
When the Lewis base moieties are bonded via a polyvalent metal atom or a polyvalent metal compound, image printing durability and non-image printing durability are preferably improved. In addition, when not only the hydrophilic binder polymer (a) but also the outer wall of the microcapsule contains a Lewis base portion, and the Lewis base portions are bonded to each other via a polyvalent metal atom or a polyvalent metal compound, an image is printed. It is more preferable because the printing properties and non-image printing durability are further improved.

In the present invention, the Lewis base moiety includes nitrogen,
Refers to a Lewis base structure containing oxygen or sulfur, specifically, an amide group, an amino group, a monoalkylamino group, a dialkylamino group, a trialkylamino group, an isouride group, an isothioureido group, an imidazolyl group, an imino group, an ureido group , Epiimino group, ureylene group, oxamoyl group, oxalo group, oxaloaceto group, carbazoyl group, carbazolyl group, carbamoyl group, carboxyl group, carboxylato group, carbimidoyl group, carbonohydrazide group, quinolyl group, guanidino group, sulfamoyl Group, sulfinamoyl group, sulfoamino group, semicarbazide group, semicarbazono group, thioureido group, thiocarbamoyl group, triazano group, triazeno group, hydrazino group, hydrazo group, hydrazono group, hydroxyamino group, hydroxyimi Group, nitrogen-containing heterocyclic, formamide group, formimidoyl group, 3-morpholinyl group and a morpholino group.

The total amount of the Lewis base moiety in the hydrophilic binder polymer (a) is preferably set to be 1 to 200% based on all monomer units.
-100% is more preferable. When the Lewis base portion is less than 1%, curing with a polyvalent metal atom or a polyvalent metal compound is not sufficient, which is not preferable. The polyvalent metal atom in the present invention refers to a metal atom having a valence of 2 or more, and specifically includes magnesium, aluminum, calcium, titanium, iron, cobalt, copper, strontium, zirconium, tin, lead, and the like. No. Among them, zirconium and tin are preferred polyvalent metal atoms.

The polyvalent metal compound in the present invention refers to metal salts, hydroxides and some oxides of the above-mentioned metals. Metal salts include magnesium chloride, magnesium bromide, aluminum chloride, calcium chloride, ferrous chloride, ferrous bromide, cobalt chloride, cobalt bromide, cupric chloride, cupric bromide, strontium chloride, odor Metal halides such as strontium chloride, stannous chloride, stannic chloride, nitrates such as magnesium nitrate, aluminum nitrate, calcium nitrate, ferrous nitrate, cobalt nitrate, copper nitrate, strontium nitrate, lead nitrate, magnesium sulfate, Sulfates such as aluminum sulfate, ferrous sulfate, cobalt sulfate, titanium sulfate, and copper sulfate; acetates such as calcium acetate, zirconium acetate, copper acetate, and lead acetate; zirconium ammonium carbonate, ferrocyanide, and ferricia Iron oxide is also used. Among them, zirconium acetate, stannous chloride and stannic chloride are particularly preferred. Hydroxides include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, titanium hydroxide, iron hydroxide, cobalt hydroxide, copper hydroxide, strontium hydroxide, zirconium hydroxide, tin hydroxide, lead hydroxide, etc. Is mentioned. Examples of the oxide include titanium oxide and tin oxide.

As a method for introducing a polyvalent metal into the recording layer, first, a hydrophilic binder polymer (a) and a microencapsulated lipophilic component (b) are coated on a support (2), and It may be supplied by a treatment, or may be previously bound to the hydrophilic binder polymer (a) or the microencapsulated lipophilic component (b). As a method for supplying a polyvalent metal atom or a polyvalent metal compound by post-treatment, immersion of a plate in a polyvalent metal ion solution or a polyvalent metal compound solution, spraying of a polyvalent metal ion solution or a polyvalent metal compound solution, and An application method is exemplified. The polyvalent metal ion solution can be obtained by dissolving the above polyvalent metal compound in a suitable solvent.

The recording layer (1) of the present invention contains, as components other than the hydrophilic binder polymer (a) and the microencapsulated lipophilic component (b), a sensitizer described below, Conversion materials, heat destroyers, color formers, reactive materials,
A hydrophilicity modifier, a melt absorbent, a lubricant, and other additives can be contained within a range that does not impair the object of the present invention. These additives are added during dope preparation,
There is a method in which the lipophilic component is included simultaneously with microencapsulation, or a method in which the lipophilic component is provided together with a binder resin between the support and the hydrophilic layer. The amount to be used may be determined from the viewpoint of the effect of the additive used and the printing durability of the non-image area.

A sensitizer is added for the purpose of accelerating the thermal destruction of the capsule, accelerating the reaction between the lipophilic component and a reactant having a functional group that reacts with the component, and accelerating the reaction between the lipophilic component and the hydrophilic binder polymer. You can do it. The addition makes it possible to increase the printing sensitivity, improve the printing durability, and perform high-speed plate making. Such sensitizers include, for example, self-decomposable substances such as nitrocellulose and substituted high-strain compounds such as cyclopropane and 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. 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 Functional Dyes in the 90s”, 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,
Examples thereof include a polyvinyl carbazole-2,3-dicyano-5-nitro-1,4-naphthoquinone complex.

For the purpose of accelerating the thermal destruction of the microcapsules, a substance which easily vaporizes or expands in volume when heated together with the lipophilic component can be put into the capsule together with the lipophilic component. For example, the boiling points of cyclohexane, diisopropyl ether, ethyl acetate, ethyl methyl ketone, tetrahydrofuran, t-butanol, isopropanol, 1,1,1-trichloroethane are sufficiently higher than room temperature, and hydrocarbons and halogenated at around 60 to 100 ° C. There are hydrocarbons, alcohols, ethers, esters and ketone compounds.

It is preferable to use a known heat-sensitive dye that develops color only in the printed portion in combination with a lipophilic component and visualize the printed portion, because plate inspection is easily performed. For example, 3-diethylamino-
Examples include 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 binder polymer, 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 binder polymer. Examples of such a reactive substance include a compound having a plurality of hydroxyl groups, amino groups, and carboxyl groups, for example, polyvinyl alcohol, polyamine, polyacrylic acid, and trimethylolpropane when the crosslinking reaction of the lipophilic component is urethane.

For the purpose of adjusting the hydrophilicity, a non-reactive hydrophilic polymer which does not react with the hydrophilic binder polymer and the lipophilic component to be used may be added to the recording layer as long as the printing durability is not impaired. When printing with the thermal head,
Calcium carbonate, silica, zinc oxide, titanium oxide, kaolin, calcined kaolin, hydrohalosite, alumina sol, diatomaceous earth, talc, etc. Known compounds can be added.

Further, it is also used to improve the slipperiness of the printing plate and to prevent adhesion when the printing plate is overlaid, and to form a solid at room temperature such as stearic acid, myristic acid, dilaurylthiodipropionate, stearic acid amide, zinc stearate and the like. A small amount of a lubricant can be added to the recording layer. Further, in order to improve the coating property when coating the recording layer (1) on the support (2) and to improve the dispersibility of the microcapsules in the dope, a polymer protective colloid such as an alginic acid derivative or a surfactant. Agents and the like can be used.

The support (2) used in the present invention may be selected from known materials in consideration of 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. In the field where low cost is required, a paper, synthetic paper, waterproof resin laminate or coated paper support can be used.

A composite support having an aluminum surface provided on paper or a plastic sheet by means of vapor deposition or lamination can also 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. In the case of a plastic sheet, corona discharge treatment, blast treatment and the like can be mentioned as preferred methods. In the case of aluminum, "Surface treatment of aluminum" by Sadajiro Kokubo (1975 Uchida Ritsuruho Shinsha), Yoshio Daimon "PS plate making and printing technology"
(Nippon Printing, 1976), Teruhiko Yonezawa, "PS Version Overview"
It is preferable to use a material subjected to a degreasing / surface roughening treatment, a degreasing / electropolishing / anodizing treatment, etc. by using a method described in a known document such as (publishing section of the Printing Society of 1993).

In the heat-sensitive lithographic printing plate precursor according to the invention, an adhesive layer may be provided between the recording layer (1) and the support (2) as long as the object of the invention is not impaired. The adhesive must be selected and designed according to the hydrophilic layer component and the support used. Shozaburo Yamada, “Encyclopedia of Adhesion and Adhesion,” published by Asakura Shoten (1986), Japan Adhesion Association, “Adhesion Handbook”
Acrylics described in Nippon Kogyo Shimbun (1980), etc.
Adhesives such as urethane, cellulose and epoxy can be used.

The heat-sensitive lithographic printing plate precursor according to the present invention may be provided with a thin film layer on the surface of the recording layer (1) as long as the object of the present invention is not impaired. By providing a thin film layer on the surface of the recording layer, it suppresses contamination from outside and causes contamination,
Further, by chemically trapping the residual polyvalent metal ion generating agent, the stain at the initial stage of printing can be greatly reduced. In particular, in the case where the substrate is left for a long time after the polyvalent metal treatment, it is preferable to provide the thin film layer. In practice, it is very useful to lay the thin film layer in consideration of the fact that a plate that has passed a certain time after drying is mostly provided.

As the polymer for the thin film layer, a polymer composed of a carbon atom or a carbon-carbon bond bonded by at least one of hetero atoms composed of oxygen, nitrogen, sulfur and phosphorus, ie, a poly (meth) acrylate-based polymer , Polyoxyalkylene, polyurethane, epoxy ring-opening addition polymerization, poly (meth) acrylic acid, poly (meth)
Acrylamide-based, polyester-based, polyamide-based, polyamine-based, polyvinyl-based, polysaccharide-based polymers or their composite polymers; polymers composed of carbon-carbon bonds, or heteroatoms composed of oxygen, nitrogen, sulfur, and phosphorus Polymers composed of at least one type of bonded carbon atom or carbon-carbon bond, ie, poly (meth) acrylate, polyoxyalkylene, polyurethane, epoxy ring-opening addition polymerization, poly (meth) acrylic acid , A poly (meth) acrylamide-based, polyester-based, polyamide-based, polyamine-based, polyvinyl-based, polysaccharide-based polymer or a composite polymer thereof,
A polymer containing at least one hydrophilic functional group such as a hydroxyl group, a phosphoric acid group, a sulfonic acid group, or a polyoxyethylene group in the structure; a polymer composed of carbon-carbon bonds, or a polymer composed of oxygen, nitrogen, sulfur, and phosphorus Polymers composed of carbon atoms or carbon-carbon bonds bonded by at least one of the following heteroatoms: poly (meth) acrylate, polyoxyalkylene, polyurethane, epoxy ring-opening addition polymerization, poly (meth) ) Acrylic acid-based, poly (meth) acrylamide-based, polyester-based, polyamide-based, polyamine-based, polyvinyl-based, polysaccharide-based, or composite polymers thereof, and containing nitrogen, oxygen, or sulfur in the structure. A polymer having a Lewis base moiety; and a polymer composed of carbon-carbon bonds, or oxygen, nitrogen Sulfur is bonded at least one heteroatom consisting of phosphorus carbon atoms or a carbon -
Polymer composed of carbon bonds, ie, poly (meth)
Acrylate, polyoxyalkylene, polyurethane, epoxy ring-opening addition polymerization, poly (meth) acrylic acid, poly (meth) acrylamide, polyester, polyamide, polyamine, polyvinyl, polysaccharide, etc. or Among these composite polymers, a polymer containing one or more hydrophilic functional groups such as a hydroxyl group, a phosphoric acid group, a sulfonic acid group, and a polyoxyethylene group in the structure, and further having a Lewis base moiety in the structure. No.

However, desirably, in consideration of the affinity and adhesion to the recording layer and the effect of chemically trapping the remaining polyvalent metal ion generating agent, a Lewis base moiety of the same type as the hydrophilic binder polymer (a) is used. Further, a polymer having a hydrophilic functional group such as a phosphoric acid group, a sulfonic acid group, and a polyoxyethylene group is preferable. The molecular weight of the polymer for a thin film layer is preferably from 1,000 to 1,000,000, more preferably from about 3000 to 100,000 in terms of number average molecular weight. If the molecular weight is lower than this range, the hydrophilic layer itself may be weakened. If the molecular weight is higher than this range, image formation may be hindered and the predetermined effect may not be exhibited.

The specific mode of providing the thin film layer on the heat-sensitive lithographic printing original plate is as follows. That is, as a method of providing a thin film layer on the recording layer surface, an aqueous solution or an organic solvent solution of a polymer for a thin film layer is applied to the recording layer surface with a bar coater or a blade coater, or sprayed with a spray, or a plate is applied to a hydrophilic polymer solution. There is a method of immersion. Since the recording layer immediately after the metal ion treatment may be vulnerable to sharp force, it is preferable to supply the hydrophilic polymer thin film layer polymer liquid in a non-contact manner. In the above, a spray method or a dipping method is preferable. Further, the formation of such a thin film layer is performed after the metal ion treatment step described later.

The concentration of the aqueous solution or the organic solvent solution of the polymer for a thin film layer used is 0.01% by weight to 5% by weight.
0% by weight is preferable, and the range of 0.1% by weight to 10% by weight is more preferable. If the concentration is lower than this range, the amount of the thin film material existing on the surface of the recording layer is too small, so that the protection of the surface of the recording layer or the chemical trapping of the residual polyvalent metal ion generating agent may not be performed sufficiently. On the other hand, if the concentration is higher than this range, the amount of the thin film material is too large, which may hinder image formation. In the present invention, the thickness of the thin film layer provided on the surface of the recording layer is 0.01 to 10 μm, and preferably 0.1 to 1 μm.

In order to make a thermal lithographic printing plate precursor according to the present invention, a document / image prepared and edited by an electronic typesetting machine, a DTP, a word processor, a personal computer or the like is drawn in a thermal mode using a thermal head and a laser in a thermal mode.・ Printing is completed without any development process.
The thermal mode drawing / printing in the present invention is, for example, printing that directly applies heat or printing that absorbs active light and converts it into heat.
A drawing / printing method for forming an image by heat. After printing, the degree of crosslinking in the 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 hydrophilic layer, the photopolymerization initiator and the photocationic polymerization initiator and a compound having a functional group through which the reaction proceeds,
It is necessary to use them in combination or to introduce the functional group into the lipophilic component. Examples of the initiator and the compound having a functional group include those described above, for example, “UV / EB Curing Handbook (Raw Materials)” edited by Kiyomi Kato, “Ultraviolet Curing System”, published by Sogo Gijutsu Center (1989), Kiyomi Kato. Publication Society (1985)
And the like can be used.

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

[0082]

[Embodiment 1] Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited to these embodiments. The particle size of the microcapsules was measured with a particle size distribution analyzer HORIBA LA910 (manufactured by Horiba, Ltd.). The thickness of the thin film layer is measured using a film thickness measuring instrument
It was measured by Seiko “Ketaro”. Further, the reflection density of the solid portion of the printed matter was measured by a reflection densitometer (DM400, manufactured by Dainippon Screen Mfg. Co., Ltd.).

(1) Synthesis of raw material for outer wall of microcapsules 3 g of tolylene diisocyanate / 1 mol of trimethylolpropane (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd., containing 25% by weight of ethyl acetate)
6 g of hydroxyethyl acrylate (Kanto Chemical Co., Ltd .; hereinafter abbreviated as 2-HEMA) was mixed in a 100 ml flask, the air in the flask was replaced with dry nitrogen, and the temperature was raised to 40 ° C. using an oil bath. . Solution temperature is 40
After confirming that the compound was stabilized at a temperature of 0.1 ° C., 0.1 g of di-n-butyltin dilaurate was added using a syringe, and the mixture was urethanized for 3 hours and 30 minutes to obtain Compound A. After the ethyl acetate was distilled off, 1 H-NMR measurement was carried out. As a result, it was found that Compound A was 33 mol of the isocyanate of 3 mol of tolylene diisocyanate / 1 mol of trimethylolpropane adduct.
% Was a substance that had been urethanized with 2-hydroxyethyl acrylate.

(2) Preparation of lipophilic component encapsulated in microcapsules 2.12 g of compound A synthesized in (1), 2.12 g of adduct of 3 mol of tolylene diisocyanate / 1 mol of trimethylolpropane, and a near-infrared absorbing dye (Nihon Kagaku) Yakuhin Co., Ltd.
An oil component was prepared by uniformly dissolving 0.93 g of Kayasorb IR-820B) in 21.7 g of glycidyl methacrylate. Then, propylene glycol alginate (Duckloid LF, manufactured by Kibun Food Chemifa Ltd., number average molecular weight: 2) was added to 116.4 g of purified water.
× 105) 3.6 g, polyethylene glycol (PEG
An aqueous phase was prepared in which 2.91 g of 400 (manufactured by Sanyo Chemical Co., Ltd.) was dissolved. The oily component and the aqueous phase were mixed and emulsified at 6000 rpm at room temperature using a homogenizer, and this emulsified dispersion was transferred into a water bath heated to 60 ° C. and stirred at 500 rpm for 3 hours to give an average particle size of 2 μm.
Was obtained. The obtained microcapsule reaction solution was purified by repeating washing with water three times after centrifugation. The outer shell of the synthesized microcapsule is 1H-NM
R analysis revealed that the repeating unit of polyethylene glycol, compound A and tolylene diisocyanate 3 mol /
It was confirmed that 5% of the methacryl group was bonded to the total of the repeating units of the 1-mol adduct of trimethylolpropane.

(3) Preparation of heat-sensitive lithographic printing plate Anodized aluminum plate (0.24 mm thick,
310 mm × 458 mm), 10% by weight aqueous solution of polyacrylic acid (Dulima AC10MP, manufactured by Nippon Pure Chemical Co., Ltd., number average molecular weight: 8 × 104): 80.0 parts by weight, microcapsule A aqueous dispersion (micro Capsule concentration: 6.5% by weight): 384 parts by weight, 3% by weight aqueous solution of propylene glycol alginate (Dacroid LF, manufactured by Kibun Food Chemifa Co., Ltd.): 100 parts by weight, and a dope prepared by mixing the dope with a bar coater. (Rod 2
No. 0) and air-dried overnight at room temperature to obtain a heat-sensitive lithographic printing material. Next, this plate was immersed in 1.5 liter of a 5% by weight aqueous solution of stannic chloride pentahydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) for 3 minutes, and purified water (manufactured by Wako Pure Chemical Industries, Ltd.) 1 Washed with liter for 6 minutes. Furthermore, this was treated with polyacrylic acid (Jurimer AC10P, manufactured by Nippon Pure Chemical Industries, Ltd., number average molecular weight:
After immersion in a 0.5% by weight aqueous solution (5 × 103) for 1 minute, the plate was erected vertically and air-dried at room temperature for 24 hours to prepare a heat-sensitive lithographic printing plate precursor A. The thickness of the recording layer was 2.5 μm, and the thickness of the hydrophilic polymer thin film layer was 0.2 μm.

(4) Preparation and printing of a lithographic printing plate On the heat-sensitive lithographic printing original plate A prepared in (3), a printing image is thermally printed by a printing device equipped with a 1W semiconductor laser element connected to an electronic typesetting device. The entire surface of the plate was irradiated with a chemical lamp at 6 J / cm 2. This plate is trimmed and an offset printing machine (HAMADA Printing Machine Co., Ltd., HAMADA)
611XL) and printed on high-quality paper (the used ink was GEOS-G manufactured by Dainippon Ink and Chemicals, and the dampening solution was diluted 100 times with EU-3 manufactured by Fuji Photo Film Co., Ltd.) thing). As a result, even after 50,000 copies, 5% highlight halftone dots were not applied and clear printing was possible. The reflection density (OD) of the solid image portion was 1.20. The results are shown in Table 1.

[0087]

Example 2 Example 1 (1) (2) (3) (except that the hydrophilic binder polymer of Example 1 was changed from polyacrylic acid (Dulimer AC10MP) to polyacrylamide (number average molecular weight 3 × 105). When a printing plate was prepared and printing evaluation was performed in the same procedure as in 4), it was determined that the printing
The printing was clear without any halftone dots of the% highlight.
The reflection density (OD) of the solid image portion was 1.20. The results are shown in Table 1. The thickness of the recording layer is 2.6 μ
m, the thickness of the hydrophilic polymer thin film layer was 0.2 μm.

[0088]

Example 3 (1) Synthesis of hydrophilic binder polymer In a separable flask, 248.5 parts by weight of acrylic acid,
Toluene (2,000 parts by weight) was weighed, and while stirring at room temperature, 2.49 parts by weight of azobisisobutyronitrile (hereinafter abbreviated as AIBN) was dissolved in 24.9 parts by weight of toluene and gradually added dropwise. Thereafter, the temperature was raised to 60 ° C., and the mixture was stirred for 3 hours. The produced and precipitated polymer was filtered, washed with about 2 liters of toluene, roughly dried at 80 ° C., and further dried under vacuum to a constant weight to obtain 235 parts by weight of a primary polymer. Next, 355 of distilled water was placed in the separable flask.
35.5 parts by weight of the primary polymer was dissolved in parts by weight. While flowing dry air through the flask, 2.84 parts by weight of glycidyl methacrylate and 2,6-di-t-butyl-
A liquid consisting of 0.1 parts by weight of p-cresol (hereinafter abbreviated as BHT) and 1 part by weight of triethylbenzylammonium chloride was added from a dropping funnel over 30 minutes while stirring the inside of the flask. After completion of the addition, the temperature was gradually increased, and when the mixture was stirred at 80 ° C. for 1 hour, a predetermined oxidation occurred. The contents were cooled, the polymer was isolated in acetone, and the polymer was massaged and washed with acetone. Thereafter, vacuum drying was performed at room temperature to obtain polymer B (glycidyl methacrylate introduction rate by NMR method: 2.2%). The number average molecular weight measured by GPC was 6 × 104.

(2) Preparation and printing of a lithographic printing plate Example 1 (1) (2) (3) (except that the hydrophilic binder polymer of Example 1 was changed from polyacrylic acid (Dulima AC10MP) to polymer B) When a printing plate was prepared and printing evaluation was performed in the same manner as in 4), clear printing was possible without any halftone dot of 5% even after 50,000 copies. The reflection density (OD) of the solid image portion was 1.20. The results are shown in Table 1. The thickness of the recording layer is 2.
5 μm and the thickness of the hydrophilic polymer thin film layer was 0.2 μm.

[0090]

Example 4 (1) Synthesis of Outer Wall Material of Microcapsules 3 g of tolylene diisocyanate / 1 mol of trimethylolpropane (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd., containing 25% by weight of ethyl acetate) and 20 g of glycerin Dimethacrylate (Light ester G101
P: Kyoeisha Chemical Co., Ltd. (4.5 g) was mixed in a 100 ml flask, the air in the flask was replaced with dry nitrogen, and the temperature was raised to 40 ° C. using an oil bath. After confirming that the temperature of the solution was stabilized at 40 ° C., 0.1 g of di-n-butyltin dilaurate was added using a syringe, and the mixture was urethanized for 2 hours to obtain Compound C. After ethyl acetate was distilled off, 1H-NMR measurement was carried out. As a result, Compound C was found to be 35 moles of the isocyanate of the adduct of 3 moles of tolylene diisocyanate / one mole of trimethylolpropane.
% Was a substance that had undergone a urethanation reaction with glycerin dimethacrylate.

(2) Preparation and printing of a lithographic printing plate Example 1 was repeated except that the compound A in Example 1 was replaced with the compound C.
(2) A printing plate was prepared and evaluated in the same manner as in (3) and (4). As a result, clear printing was possible without any halftone dots of 5% even after 50,000 copies. The reflection density (OD) of the solid image portion was 1.20. The results are shown in Table 1. The average particle size of the microcapsules is 3μ
m, the ratio of the methacryl group to the repeating unit of the outer wall material was 10%, the thickness of the recording layer was 3.9 μm, and the thickness of the hydrophilic polymer thin film layer was 0.2 μm.

[0092]

Example 5 (1) Synthesis of raw material for outer wall of microcapsule 67.5 g of polymethylene polyphenyl polyisocyanate (Millionate MR400, manufactured by Nippon Polyurethane Industry Co., Ltd., hereinafter abbreviated as Millionate) and 2-HEMA (Kanto Chemical Co., Ltd.) ) 13.4 g was mixed in a 200 ml flask and urethanized at room temperature for 3 hours to obtain compound D. 1H-NMR confirmed that 10% of the isocyanate in the millionate was modified by 2-HEMA. (2) Preparation and printing of a lithographic printing plate Example 1 was repeated except that Compound A of Example 1 was changed to Compound D.
(2) A printing plate was prepared and evaluated in the same manner as in (3) and (4). As a result, clear printing was possible without any halftone dots of 5% even after 50,000 copies. The reflection density (OD) of the solid image portion was 1.20. The results are shown in Table 1. The average particle size of the microcapsules is 1.9.
μm, the ratio of the methacryl group to the repeating unit of the outer wall material was 10%, the thickness of the recording layer was 2.4 μm, and the thickness of the hydrophilic polymer thin film layer was 0.2 μm.

[0093]

Comparative Example (1) Preparation of microencapsulated lipophilic component 3 mol of tolylene diisocyanate / 1 mol of trimethylolpropane (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd., containing 25% by weight of ethyl acetate) 4 .24
g, near infrared absorbing dye (Kayas manufactured by Nippon Kayaku Co., Ltd.)
orbIR-820B) was uniformly dissolved in 21.7 g of glycidyl methacrylate to prepare an oily component. Then, propylene glycol alginate (Duckloid LF, manufactured by Kibun Food Chemifa Corporation, number average molecular weight: 2 × 105) was added to 116.4 g of purified water.
3.6 g, polyethylene glycol (PEG 400,
An aqueous phase in which 2.91 g of Sanyo Kasei Co., Ltd. was dissolved was prepared. Subsequently, after mixing and emulsifying the oily component and the aqueous phase at room temperature at 6000 rpm using a homogenizer, the emulsified dispersion was transferred together with the container into a water bath heated to 60 ° C., and stirred at 500 rpm for 3 hours. Microcapsules E having an average particle size of 2 μm were obtained.

(2) Preparation and printing of a lithographic printing plate A printing plate was prepared and evaluated in the same procedure as in Examples 1 (3) and (4) except that the microcapsules A in Example 1 were replaced with the microcapsules E. Was performed and the printed matter at the time of printing 50,000 copies was analyzed. As a result, halftone dots of 5% highlight were found, and the image of the low gradation part was unclear. Also,
The reflection density (OD) of the solid image portion was 1.20. The results are shown in Table 1. The average particle size of the microcapsules was 1.9 μm, the thickness of the recording layer was 2.4 μm, and the thickness of the hydrophilic polymer thin film layer was 0.2 μm.

[0095]

[Table 1]

[0096]

According to the present invention, it is possible to provide a lithographic printing plate having high image printing durability and a lithographic printing plate precursor capable of producing the same. Since the non-image portion of the heat-sensitive lithographic printing plate precursor of the present invention is mainly formed of a hydrophilic polymer, development is unnecessary in the plate-making process of the present invention,
There is no need to work on developer management and waste liquid treatment,
Work efficiency and cost reduction can be achieved. Also,
Since the plate making apparatus can be made compact and the apparatus price can be designed low, it is very useful in industry.

Claims (6)

[Claims] 1. A heat-sensitive lithographic printing plate precursor comprising: a recording layer containing a microencapsulated lipophilic component which is converted into an image area by heat and a hydrophilic binder polymer; and a support. A heat-sensitive lithographic printing plate precursor, wherein the material has an addition-polymerizable functional group. 2. The heat-sensitive lithographic printing plate precursor according to claim 1, wherein the addition-polymerizable functional group is a carbon-carbon double bond. 3. The heat-sensitive lithographic printing plate precursor according to claim 2, wherein the carbon-carbon double bond is at least one of an acryl group, a methacryl group and an allyl group. 4. The heat-sensitive lithographic printing plate precursor according to claim 1, wherein the addition-polymerizable functional group is either an epoxy group or a glycidyl group. 5. The heat-sensitive lithographic printing plate precursor according to claim 1, wherein the wall material of the microencapsulated lipophilic component has a urea-urethane structure. 6. The heat-sensitive lithographic printing plate precursor according to claim 5, wherein a trifunctional or higher functional isocyanate compound is used as a raw material of the urethane-urea wall material.