JP2002002143A - Original plate for lithographic printing and its manufacturing method as well as platemaking method using the same and method for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for lithographic printing capable of printing by directly mounting the plate in a printing machine without treating after exposure and having good on-press developability, improved plate life and good anti-scumming properties. SOLUTION: The original plate for lithographic printing comprises a hydrophobic precursor on an aluminum support having an anodized film and a hydrophilic layer to become hydrophobic by a heat in such a manner that a mean pore size of micropores of the anodized film is 6 to 40 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative type lithographic printing plate precursor. More specifically, it is a lithographic printing plate precursor that can make plate by scanning exposure based on digital signals, can provide high printing durability, and can give printed products without stains. The present invention relates to a lithographic printing original plate that can be mounted and printed.

[0002]

2. Description of the Related Art Numerous studies have been made on printing plates for computer-to-plate systems, which have been remarkably advanced in recent years. Among them, with the aim of further streamlining the process and solving the problem of waste liquid treatment, development-free lithographic printing plates that can be mounted on a printing machine and printed without developing after exposure have been studied, and various methods have been studied. Proposed.

[0003] One of the methods for eliminating the processing step is to mount an exposed printing master on a cylinder of a printing press, and supply a dampening solution and ink while rotating the cylinder to thereby obtain a non-image of the printing master. There is a method called on-press development for removing a part. That is, the printing master is mounted on a printing machine as it is after exposure, and the process is completed in a normal printing process. As a lithographic printing plate suitable for the on-press development, a lithographic printing plate having a hydrophilic layer which is soluble in a fountain solution or an ink solvent and is converted to hydrophobic by heat due to infrared exposure or the like is known.

For example, Japanese Patent No. 2938397 discloses an original plate for lithographic printing wherein a hydrophilic layer in which fine particles of a thermoplastic hydrophobic polymer are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support. I have. According to this publication, the lithographic printing original plate is subjected to infrared laser exposure to form an image by heat-bonding thermoplastic hydrophobic polymer fine particles to form an image. Then, the plate is mounted on a printing press cylinder, and dampening water and / or Alternatively, it is described that on-press development can be performed with ink.

Further, Japanese Patent Application Laid-Open Nos. 9-127683 and WO99-10186 also disclose that a printing plate is prepared by on-press development after combining thermoplastic fine particles by heat.

[0006] However, the above-described method of forming an image by combining fine particles by heat has a problem that, although showing good on-press developability, printing strength is insufficient due to low image strength.

Further, Japanese Patent Application Laid-Open No. 8-48020 discloses that
A method is described in which a lipophilic thermosensitive layer is provided on a porous hydrophilic support, exposed to infrared laser, and the lipophilic thermosensitive layer is fixed to a substrate by heat. However, a lipophilic film has poor on-press developability, and there is a problem that scum of the lipophilic hydrophilic layer adheres to an ink roller or printed matter.

[0008]

As described above, a heat-sensitive lithographic printing plate having good on-press developability and high printing durability has not yet been obtained. Therefore, as a result of various studies, a hydrophilic layer composed of microcapsules containing a compound having a functional group whose outer wall is broken by heat used for image formation and reacts by the heat is provided on a hydrophilic support, and photothermal conversion is performed. By using the lithographic printing plate precursor containing the agent in the hydrophilic layer and / or the layer adjacent thereto, a lithographic printing plate precursor having good on-press developability and high printing durability can be obtained. I understand (Japanese Patent Application 2000-18)
968). However, even in this lithographic printing plate precursor, the printing durability was not sufficient because the adhesion between the aluminum support and the image was weak, and further improvement was desired. As a countermeasure, it is known to use a phosphoric acid bath anodic oxide film having a strong adhesive force, but this method has a problem in that the ink dispensing property is deteriorated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and has a good on-press developability, a higher printing durability, and a good printing resistance such as ink wiping. To provide a lithographic printing plate.

[0010]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that the above-mentioned object comprises the following support composed of a heat-reactive hydrophilic layer and an adhesion-improving support in which the pore diameter of the micropores of the anodic oxide film is adjusted. It has been found that this can be achieved by configuration. Furthermore, it has been found that such an adhesion-improving support has an effect of improving printing durability in combination with not only a heat-reactive hydrophilic layer but also a hydrophilic layer containing hydrophobic thermoplastic fine particles which are melted by heat. That is, the present invention is as follows.

1. An original plate for lithographic printing having a hydrophilic layer containing a hydrophobizing precursor and becoming hydrophobic by heat on an aluminum support having an anodized film, wherein the average pore diameter of the micropores of the anodized film is 6 to A lithographic printing original plate having a thickness of 40 nm.

2. The micropores of the anodic oxide film are subjected to an enlarging treatment or an enlarging treatment followed by a sealing treatment, so that an aluminum support having an average pore diameter of the micropores of 6 to 40 nm contains a hydrophobizing precursor and heat-treated. A lithographic printing original plate comprising a hydrophilic layer that becomes more hydrophobic.

3. Microcapsules containing (a) hydrophobic thermoplastic fine particles that melt by heat, (b) polymer fine particles having a thermoreactive functional group, and (c) a compound having a thermoreactive functional group. 3. The lithographic printing original plate as described in 1 or 2 above, which is at least one component selected from the group consisting of:

4. 4. The lithographic printing original plate as described in any one of 1 to 3 above, further comprising a water-soluble overcoat layer on the hydrophilic layer.

[0015] 5. The lithographic printing original plate as described in any one of the above items 1 to 4, further comprising an undercoat layer between the support and the hydrophilic layer.

6. The lithographic printing original plate as described in any one of 1 to 5 above, wherein at least one of the hydrophilic layer, the overcoat layer, and the undercoat layer contains a photothermal conversion agent.

[7] Microporous expansion of the anodic oxide film by immersing the support having the anodic oxide film in sulfuric acid, phosphoric acid, a mixture of both, or an alkaline aqueous solution having a pH of 11 to 13, or microporous treatment by enlarging and then sealing. (A) hydrophobic thermoplastic fine particles which melt by heat, (b) polymer fine particles having a thermoreactive functional group, and (c) thermoreactivity on an aluminum support having an average pore diameter of the pores of 6 to 40 nm. A method for producing a lithographic printing original plate, comprising providing a hydrophilic layer containing at least one component selected from microcapsules containing a compound having a functional group.

[8] The lithographic printing plate precursor according to any one of the preceding items 1 to 6, is image-exposed with a laser beam and attached to a printing machine for printing, or after being attached to the printing machine, exposed to a laser beam on a printing machine and left as it is. Plate making and printing method of a lithographic printing original plate, characterized by printing.

[0019]

Embodiments of the present invention will be described below in detail. In the present invention,% means mass% unless otherwise specified. The aluminum support used in the present invention is a dimensionally stable metal containing aluminum as a main component, and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, it is selected from an alloy plate containing aluminum as a main component and containing a trace amount of a different element, or a plastic film or paper on which aluminum (alloy) is laminated or evaporated. Further, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in JP-B-48-18327 may be used. In the following description, the above-mentioned supports made of aluminum or an aluminum alloy are collectively used as aluminum supports.

The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of the foreign element in the alloy is 10% or less. is there. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the aluminum plate applied to the present invention is not specified for its composition, and is made of a conventionally known and used material, for example, JIS A10
50, JIS A 1100, JIS A 3103, JIS A 3005, etc. can be used as appropriate.

The thickness of the aluminum support used in the present invention is about 0.1 to 0.6 mm.
This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the user's request. The aluminum support is appropriately subjected to a support surface treatment described below.

The surface of the aluminum support used in the present invention can be grained. Examples of the graining method include mechanical graining, chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, an electrochemical graining method in which the aluminum surface is electrochemically grained in a hydrochloric acid or nitric acid electrolyte, a wire brush graining method in which the aluminum surface is scratched with a metal wire, and a ball graining method in which the aluminum surface is grained with a polishing ball and an abrasive. A mechanical graining method such as a brush graining method in which the surface is grained with a nylon brush and an abrasive can be used, and these graining methods can be used alone or in combination.

Among them, a method for producing a surface roughness usefully used in the present invention is an electrochemical method of chemically graining in a hydrochloric acid or nitric acid electrolyte, and a suitable current density is 100 to 400 C / dm. It is in the range of ² . More specifically, electrolysis is performed in an electrolytic solution containing 0.1 to 50% hydrochloric acid or nitric acid at a temperature of 20 to 100 ° C., a time of 1 second to 30 minutes, and a current density of 100 to 400 C / dm ^2. Is preferred.

The aluminum support thus grained is chemically etched, if necessary, with an acid or an alkali. When an acid is used as an etching agent, it takes time to destroy a fine structure, which is disadvantageous when applied to the present invention industrially. However, it can be improved by using an alkali as an etching agent. Alkali agents suitably used in the present invention are sodium hydroxide, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide, and the like. ~ 50
%, 20 to 100 ° C., and the amount of aluminum dissolved is 5%.
It is preferable that the condition be 〜20 g / m ² .

Next, dirt (smut) remaining on the surface
Pickling is performed to remove the acid. As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borofluoric acid and the like are used. In particular, as a method for removing the smut after the electrochemical surface-roughening treatment, JP-A-53-1 is preferred.
No. 2739, a method of contacting with sulfuric acid of 15 to 65% at a temperature of 50 to 90 ° C., and a method of alkali etching described in JP-B-48-28123.

The aluminum support thus treated is further subjected to an anodizing treatment. The anodizing treatment can be performed by a method conventionally performed in this field. Specifically, a direct current or an alternating current is applied to an aluminum support in an aqueous solution or a non-aqueous solution containing one or more of sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, and the like. Thereby, an anodic oxide film can be formed on the surface of the aluminum support.

The conditions of the anodic oxidation treatment vary depending on the electrolytic solution to be used, and thus cannot be unconditionally determined. However, generally, the concentration of the electrolytic solution is 1 to 80%, the liquid temperature is 5 to 70 ° C., and the current density is The suitable range is 0.5 to 60 A / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 to 150 seconds.

In the present invention, the anodic oxide film has a thickness of 1-1.
It is preferably 0 g / m ² , and if it is less than 1 g / m ² , the plate is likely to be damaged, and a large amount of power is required to make the film thickness more than 10 g / m ² , which is economically disadvantageous. .
More preferably, it is 1.5 to 7 g / m ² . More preferably, it is ² to 5 g / m ² .

The above-mentioned anodic oxide film has fine concave portions called micropores formed uniformly on its surface. The present invention is characterized in that the average value of the pore diameters of the micropores (also referred to as the average pore diameter or simply the pore diameter) is adjusted to a certain range. The average pore diameter of the present invention is 6 to 40 nm, more preferably 6 to 20 nm.
And more preferably 9 to 20 nm. When the average pore diameter of the micropores is within these ranges, sufficient adhesion to the hydrophilic layer described later can be obtained while maintaining good ink wiping properties, and high printing durability can be obtained.

In order to adjust the pore diameter, the aluminum support having the anodic oxide film formed thereon is immersed in an aqueous solution of acid or alkali to dissolve the anodic oxide film and increase the pore diameter of the micropores (pore wide treatment). ),
Alternatively, the pore widening process and the subsequent sealing process can be performed. The average pore diameter of the present invention is a value measured for the micropores after these treatments.

The following conditions are preferable as the processing conditions for dissolving the anodic oxide film due to the above-mentioned pore width. If the amount is out of this range, the time required for dissolution becomes extremely long and the working efficiency is lowered. On the other hand, the dissolution is performed in an extremely short time, which makes practical control impossible. As a specific condition range, when treating with an acid aqueous solution, it is preferable to use an aqueous solution of sulfuric acid, phosphoric acid, or a mixture thereof, and the concentration is preferably 10 to 500 g / l, more preferably 20 to 100 g.
/ L, the temperature is preferably 10 to 90 ° C, more preferably 40 to 70 ° C, and the immersion treatment time is preferably 10 to 300 seconds, more preferably 30 to 120 seconds. On the other hand, when treating with an aqueous alkali solution, it is preferable to use an aqueous solution of sodium hydroxide, potassium hydroxide, lithium hydroxide, or a mixture thereof,
The pH of the aqueous solution is preferably 11 to 13, more preferably 11.5 to 12.5, and the temperature is preferably 10 to 90 ° C, more preferably 30 to 5 ° C.
0 ° C., the immersion time is preferably 5 to 300
Seconds, more preferably 10 to 30 seconds.

The sealing treatment applied after the pore widening treatment of the present invention includes hot water treatment, boiling water treatment, steam treatment,
A known method such as a dichromate treatment, a nitrite treatment, an ammonium acetate treatment, and an electrodeposition sealing treatment can be used.

As a method of hot water treatment, steam treatment or boiling water treatment, there are many known examples such as Japanese Patent Laid-Open Nos. 4-176690 and 5-131773. The treatment temperature is about 95 to 200 ° C., preferably 100
~ 150 ° C is good and the processing time is 5 ~ 100 ° C.
About 150 seconds, at 150 ° C., about 1 to 30 seconds is preferable.

As another sealing treatment, JP-B-36-220
It is also possible to use a fluorinated zirconic acid treatment as disclosed in JP-A-63-63, etc. Alternatively, JP-A-9-2
No. 44227, a method of treating with an aqueous solution containing a phosphate and an inorganic fluorine compound can be used. Further, a method of treating with an aqueous solution containing a sugar disclosed in JP-A-9-134002 can also be used. In addition, a method of treating with an aqueous solution containing titanium and fluorine disclosed in Japanese Patent Application Nos. 10-252078 and 10-253411 can be used.
In addition, treatment using an alkali metal silicate may be performed, and in that case, a method disclosed in US Pat. No. 3,181,461 can be used.

In the alkali metal silicate treatment, an alkali metal silicate aqueous solution having a pH of 10 to 13 at 25 ° C. which does not cause gelation of the solution and dissolution of the anodic oxide film is used. The sealing process can be performed by appropriately selecting processing conditions such as concentration, processing temperature, and processing time. Suitable alkali metal silicates include sodium silicate, potassium silicate, lithium silicate and the like. In order to adjust the pH of the alkali metal silicate aqueous solution to a high value, sodium hydroxide, potassium hydroxide, lithium hydroxide, or the like can be added.

If necessary, an alkaline earth metal salt or a Group IVB metal salt may be added to the aqueous alkali metal silicate solution. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and sulfates, hydrochlorides, phosphates, acetates, oxalates, and borates of these alkaline earth metals. And water-soluble salts such as salts. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, and the like. be able to. Alkaline earth metal salt or No.
Group IVB metal salts can be used alone or in combination of two or more. The preferred use amount range of these metal salts is 0.01 to 10%, and the more preferred range is 0.05 to 5.0%.

The support used in the present invention may be provided with an undercoat layer if necessary before applying the hydrophilic layer. Examples of the compound used for the undercoat layer include polyvinyl phosphonic acid, polymers and copolymers having a sulfonic acid group in a side chain, polyacrylic acid, water-soluble metal salts (eg, zinc borate), carboxymethyl cellulose, dextrin, Gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid which may have a substituent Organic phosphonic acids such as acids, phenylphosphoric acid optionally having a substituent, naphthylphosphoric acid, organic phosphoric acid such as alkylphosphoric acid and glycerophosphoric acid, phenylphosphinic acid optionally having a substituent, naphthylphosphinic acid, Organic phosphines such as alkylphosphinic acid and glycerophosphinic acid Phosphate, can be mentioned glycine or β- alanine, and hydrochlorides of amines having a hydroxyl group such as triethanolamine hydrochloride and the like. These may be used in combination of two or more.

This undercoat layer can be provided by the following method. That is, water or an organic solvent such as methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof, a solution in which the above organic compound is dissolved is coated on an aluminum plate and dried to form a water or methanol, ethanol, methyl ethyl ketone. In an organic solvent such as an organic solvent or a mixed solvent thereof, a solution in which the above organic compound is dissolved is immersed in an aluminum support to adsorb the organic compound, and then washed with water or the like and dried to form an undercoat layer. Can be by way. In the former method, 0.005 to 10
% Solutions can be applied in various ways. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used. In the latter method, the concentration of the solution is preferably 0.01 to 20%, more preferably 0.05 to 5%, and the immersion temperature is preferably 20 to 90 ° C, more preferably 25 to 50 ° C. ° C, and the immersion time is preferably 0.1 seconds to 20 minutes, more preferably 2 seconds to 1 minute. The pH of the solution used for this can be adjusted with a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, or an acidic substance such as hydrochloric acid or phosphoric acid.

The coating amount of the undercoat layer after drying is from 2 to 200
mg / m ² is appropriate, and preferably 5 to 100 mg / m ^2.
m ² . Good printing durability is obtained within this range.

The hydrophilic layer of the present invention comprises a component selected from hydrophobic thermoplastic fine particles which melt by heat, polymer fine particles having a heat-reactive functional group, and microcapsules containing a compound having a heat-reactive functional group. contains.

The hydrophobic thermoplastic fine particles used in the hydrophilic layer of the present invention are preferably thermoplastic hydrophobic polymer fine particles having a solidification temperature of 35 ° C. or higher, and more preferably 50 ° C. or higher. There is no particular upper limit on the solidification temperature of the thermoplastic hydrophobic polymer particles, but this temperature must be sufficiently lower than the decomposition point of the polymer particles. When the polymer particulates are raised above the coagulation temperature, they fuse and coalesce to form hydrophobic agglomerates in the hydrophilic layer. Therefore, these parts become insoluble in water or aqueous liquid,
It becomes ink receptive.

As specific examples of the hydrophobic polymer constituting the hydrophobic particles used in the hydrophilic layer of the present invention, for example, ethylene, styrene, vinyl chloride, methyl (meth) acrylate, ethyl (meth) acrylate, vinylidene chloride , Acrylonitrile, vinylcarbazole, and other homopolymers or copolymers of monomers or mixtures thereof. Among them, polystyrene and polymethyl methacrylate are particularly preferable.

The polymer constituting the hydrophobic thermoplastic fine particles of the present invention has a weight average molecular weight of 5,000 to 1,000,000.
00 is preferable, and the particle diameter of the hydrophobic thermoplastic fine particles is 0.0
1-50 μm is preferred, 0.05-10 μm is more preferred, and 0.05-2 μm is most preferred.

The amount of the hydrophobic thermoplastic polymer particles added to the hydrophilic layer is preferably 50% or more, more preferably 60% or more, of the solid content of the hydrophilic layer.

As the heat-reactive functional group in the polymer microparticles containing the heat-reactive functional group-containing polymer fine particles and the compound having the heat-reactive functional group of the present invention, an ethylenically unsaturated group (for example, Acryloyl group, methacryloyl group, vinyl group, allyl group, etc.),
An isocyanate group or a block thereof that performs an addition reaction and a functional group having an active hydrogen atom (eg, an amino group, a hydroxyl group, a carboxyl group, etc.) that is a reaction partner thereof, and an epoxy group that performs an addition reaction and its reaction partner. A certain amino group, carboxyl group or hydroxyl group, carboxyl group and hydroxyl group or amino group for condensation reaction, acid anhydride for ring-opening addition reaction with amino group or hydroxyl group, and diazonium which thermally decomposes to hydroxyl group And the like. However, a functional group that performs any reaction may be used as long as a chemical bond is formed.

The polymer fine particles having a thermoreactive functional group used for the hydrophilic layer of the present invention include acryloyl group, methacryloyl group, vinyl group, allyl group, epoxy group,
Examples thereof include an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, an acid anhydride and those having a group protecting them. The introduction of these functional groups into the polymer fine particles may be performed at the time of polymerization, or may be performed using a polymer reaction after polymerization.

When introduced during polymerization, it is preferable to carry out emulsion polymerization or suspension polymerization of these monomers having a thermoreactive functional group. If necessary, a monomer having no heat-reactive functional group may be added as a copolymerization component.

Specific examples of such a monomer having a functional group include allyl methacrylate, allyl acrylate, vinyl methacrylate, vinyl acrylate, glycidyl methacrylate, glycidyl acrylate,
Blocked isocyanate with isocyanate ethyl methacrylate or its alcohol, blocked isocyanate with 2-isocyanate ethyl acrylate or its alcohol, 2-aminoethyl methacrylate, 2-aminoethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylic acid Methacrylic acid, maleic anhydride, bifunctional acrylate, bifunctional methacrylate, and the like, but are not limited thereto.

The monomers having no heat-reactive functional groups copolymerizable with these monomers include, for example, styrene, alkyl acrylate, alkyl methacrylate,
Examples thereof include acrylonitrile and vinyl acetate, but are not limited thereto as long as they do not have a thermally reactive functional group.

The polymer reaction used when the heat-reactive functional group is introduced after the polymerization is, for example, WO96-34.
316 publication.

Among the above-mentioned polymer fine particles having a thermoreactive functional group, those in which the polymer fine particles are united by heat are preferable, and those whose surface is hydrophilic and which is dispersed in water are particularly preferable. The contact angle (water droplets in the air) of a film produced by applying only polymer fine particles and drying at a temperature lower than the coagulation temperature is lower than the contact angle of the film produced by drying at a temperature higher than the coagulation temperature ( (Water droplets in the air). In order to make the surface of the polymer fine particles hydrophilic, a hydrophilic polymer or oligomer such as polyvinyl alcohol or polyethylene glycol, or a hydrophilic low-molecular compound may be adsorbed on the surface of the polymer fine particles. However, the present invention is not limited to this.

The solidification temperature of these polymer particles having a thermoreactive functional group is preferably 70 ° C. or higher, and more preferably 100 ° C. or higher in view of the stability over time. The average particle size of the polymer particles is preferably 0.01 to 20 μm, more preferably 0.05 to 2.0 μm, and most preferably 0.1 to 1.0 μm. If the average particle size is too large, the resolution will be poor, and if it is too small, the stability over time will be poor.

The addition amount of the polymer fine particles having a reactive functional group is preferably at least 50%, more preferably at least 60% of the solid content of the hydrophilic layer.

The microcapsules used in the present invention are:
It contains a compound having a thermoreactive functional group. The compound having a heat-reactive functional group was selected from polymerizable unsaturated groups, hydroxyl groups, carboxyl groups or carboxylate groups or acid anhydrides, amino groups, epoxy groups, and isocyanate groups or blocks thereof. Compounds having at least one functional group can be mentioned.

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

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

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

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

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

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

Examples of other esters include, for example, JP-B-46-27926, JP-B-51-47334,
Aliphatic alcohol esters described in JP-A-57-196231, JP-A-59-5240 and JP-A-59-196231
Examples thereof include those having an aromatic skeleton described in JP-A-5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613.

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

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

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

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

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

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

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

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

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

Suitable compounds having a hydroxyl group include compounds having a terminal methylol group, polyhydric alcohols such as trimethylolpropane and pentaerythritol, bisphenols and polyphenols.

Preferred compounds having a carboxyl group include aromatic polycarboxylic acids such as pyromellitic acid, trimellitic acid and phthalic acid, and aliphatic polycarboxylic acids such as adipic acid.

Suitable compounds having a hydroxyl group or a carboxyl group include, in addition to those described above, for example,
No.-19773, No.55-34929, No.57-43
A compound known as a binder for an existing PS plate described in JP-A-890-90 can also be used.

Suitable acid anhydrides include pyromellitic anhydride, benzophenonetetracarboxylic anhydride and the like.

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

As the diazo resin, a hexafluorophosphate or an aromatic sulfonate of a diazodiphenylamine / formalin condensed resin is preferable.

As a method for microencapsulation, a known method can be applied. For example, as a method for producing microcapsules, US Pat.
U.S. Pat. No. 3,287,154, U.S. Pat. No. 3,287,154.
No. 38-19574, JP-B-42-446, JP-B-42-711, a method by precipitation of a polymer shown in U.S. Pat. Nos. 3,418,250 and 3,660,304, U.S. Pat. No. 3,796,669. U.S. Pat. No. 3,914,140, U.S. Pat. No. 4,087,376, U.S. Pat. No. 4,089,802. Urea-formaldehyde or urea-formaldehyde.
Method using resorcinol-based wall forming material, US Pat.
No. 025445, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, Japanese Patent Publication Nos. 36-9163 and 51-9079, an in situ method by monomer polymerization, and British Patent 930.
No. 422, U.S. Pat. No. 3,111,407, Spray drying method, British Patent Nos. 952807, 96707
No. 4, but not limited thereto.

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

The average particle size of the above microcapsules is
0.01 to 20 μm is preferable, and 0.05 to
2.0 μm is more preferred, and 0.10 to 1.0 μm is particularly preferred. If the average particle size is too large, the resolution will be poor,
On the other hand, if it is too small, the stability over time will be poor.

In such microcapsules, the capsules may or may not be combined by heat. In short, of the microcapsule inclusions, those that oozed out of the capsule surface or outside the microcapsules during application, or those that penetrated the microcapsule wall,
A chemical reaction may be caused by heat. It may react with the added hydrophilic resin or the added low molecular compound. The microcapsules may be reacted with each other by providing two or more types of microcapsules with functional groups that react with each other with different functional groups. Therefore, it is preferable from the viewpoint of image formation that the microcapsules are fused and fused by heat.
Not required.

The addition amount of these microcapsules to the hydrophilic layer is preferably 50% or more of the solid content of the hydrophilic layer,
The above is more preferred.

When microcapsules are added to the hydrophilic layer, a solvent in which the inclusions dissolve and the wall material swells can be added to the microcapsule dispersion medium. Such a solvent promotes the diffusion of the encapsulated compound having a thermoreactive functional group out of the microcapsules.

Such a solvent depends on the microcapsule dispersion medium, the material of the microcapsule wall, the wall thickness and the inclusions, but can be easily selected from many commercially available solvents. For example, in the case of water-dispersible microcapsules composed of crosslinked polyurea and polyurethane walls, alcohols, ethers, acetals, esters,
Ketones, polyhydric alcohols, amides, amines, fatty acids and the like are preferred.

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

A solvent which does not dissolve in the microcapsule dispersion but can be dissolved by mixing the above-mentioned solvent can be used. The amount of addition is determined by the combination of materials. If the amount is less than the appropriate value, image formation becomes insufficient, and if the amount is too large, the stability of the dispersion is deteriorated. Normal,
The effective range is 5 to 95% of the coating solution, and the preferable range is 10 to 95%.
９０90%, more preferably 15-85%.

In the case of using polymer fine particles or microcapsules having a heat-reactive group in the hydrophilic layer of the present invention, a compound which initiates or promotes these reactions may be added as necessary. Examples of the compound that initiates or promotes the reaction include a compound that generates a radical or a cation by heat,
Examples thereof include lophine dimers, trihalomethyl compounds, peroxides, azo compounds, onium salts containing diazonium salts or diphenyliodonium salts, acylphosphines, imidosulfonates, and the like.

These compounds are prepared by adding 1 to 2 solid components of the hydrophilic layer.
It can be added in the range of 0%. Preferably 3 to 1
The range is 0%. Within this range, a favorable reaction initiation or acceleration effect can be obtained without impairing the on-press developability.

A hydrophilic resin may be added to the hydrophilic layer of the present invention. The addition of the hydrophilic resin not only improves the on-press developability but also improves the film strength of the hydrophilic layer itself.

Examples of the hydrophilic resin include a hydroxyl group, a hydroxyethyl group, a hydroxypropyl group, an amino group, an aminoethyl group, an aminopropyl group, a carboxyl group, a carboxylate group, a sulfo group, a sulfonato group and a phosphate group. Those having a hydrophilic group are preferred.

Specific examples of the hydrophilic resin include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers,
Polyacrylic acids and their salts, polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers of hydroxypropyl acrylate and Copolymers, hydroxybutyl methacrylate homopolymers and copolymers, hydroxybutyl acrylate homopolymers and copolymers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and a hydrolysis degree of at least 60%, preferably at least 80% Polyvinyl acetate, polyvinyl formal, polyvinyl butyral, poly Nirupiroridon, homopolymers and copolymers of acrylamide, mention may be made of homopolymers and copolymers of methacrylamide, the N- methylol acrylamide homopolymers and copolymers, and the like.

The amount of the hydrophilic resin added to the hydrophilic layer is preferably from 5 to 40%, more preferably from 10 to 30% of the solid content of the hydrophilic layer. Within this range, good on-press developability and film strength can be obtained.

The hydrophilic layer of the present invention may further contain various compounds other than those described above, if necessary. For example, a polyfunctional monomer can be added to the hydrophilic layer in order to further improve the printing durability. As the polyfunctional monomer, those exemplified as the monomer to be put in the microcapsule can be used. Particularly preferred monomers include trimethylolpropane triacrylate.

[0093] The hydrophilic layer of the present invention may contain a crosslinking agent, if necessary. Suitable crosslinking agents include low molecular weight compounds having a methylol group, such as melamine-formaldehyde resin, hydantoin-formaldehyde resin, thiourea-formaldehyde resin, and benzoguanamine-formaldehyde resin.

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

When an ethylenically unsaturated compound is used in the present invention, a small amount of a thermal polymerization inhibitor may be added in order to prevent unnecessary thermal polymerization during preparation or storage of the hydrophilic layer coating solution. desirable. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-
t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3
-Methyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl-6-t-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to 5% based on the weight of the whole composition.

Further, if necessary, a higher fatty acid such as behenic acid or behenic acid amide or a derivative thereof is added to prevent polymerization inhibition by oxygen. It may be unevenly distributed. The amount of the higher fatty acid or derivative thereof added is about 0.1 to about 10% of the solid content of the hydrophilic layer.
Is preferred.

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

The hydrophilic layer of the present invention is prepared by dissolving each of the above-mentioned necessary components in a solvent to prepare a coating solution, and is coated on the hydrophilic layer.
As the solvent used here, ethylene dichloride,
Cyclohexanone, methyl ethyl ketone, methanol,
Ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-
Methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, toluene, water and the like,
It is not limited to this. These solvents are used alone or as a mixture. The solid content concentration of the coating solution is preferably 1 to 50%.

The coating amount (solid content) of the hydrophilic layer on the support obtained after coating and drying varies depending on the application, but is generally preferably 0.5 to 5.0 g / m ² . When the coating amount is smaller than this range, the apparent sensitivity is increased, but the film characteristics of the hydrophilic layer that performs the function of image recording are reduced. Various methods can be used as a method of applying. For example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating,
Examples include blade coating and roll coating.

The hydrophilic layer coating solution according to the present invention may contain a surfactant for improving coating properties, for example, a surfactant described in
A fluorinated surfactant as described in JP 170950 can be added. A preferable addition amount is 0.01 to 1% of the total solid of the hydrophilic layer, more preferably 0.01%.
5 to 0.5%.

The lithographic printing plate precursor according to the present invention is provided on the hydrophilic layer in order to prevent the surface of the hydrophilic layer from being contaminated by a lipophilic substance during storage or handling, for example, in the form of a fingerprint.
A water-soluble overcoat layer can be provided. The water-soluble overcoat layer used in the present invention can be easily removed at the time of printing and contains a resin selected from water-soluble organic polymer compounds. As the water-soluble organic polymer compound used herein, a film formed by coating and drying has a film-forming ability, specifically, polyvinyl acetate (having a hydrolysis rate of 65% or more), acrylic acid Homopolymers or copolymers and their alkali metal salts or amine salts, methacrylic acid homopolymers or copolymers and their alkali metal salts or amine salts, acrylamide homopolymers and copolymers, polyhydroxyethyl acrylate, N- Vinylpyrrolidone homopolymer and copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer, 2-acrylamido-2-methyl-1-propanesulfonic acid homopolymer or copolymer, and alkali metal thereof Salt or amine salt, gum arabic, cellulose derivative For example, mention may be made of carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose, etc.) and modified products thereof, white dextrin, pullulan, enzymolysis etherified dextrin. Further, according to the purpose, two or more of these resins can be used in combination.

Further, the above-mentioned light-to-heat conversion agent may be added to the overcoat layer. Furthermore, in the case of aqueous solution application, a nonionic surfactant such as polyoxyethylene nonylphenyl ether and polyoxyethylene dodecyl ether can be added to the overcoat layer in order to ensure uniformity of application. .

The dry coating amount of the overcoat layer was 0.1
-2.0 g / m < ² > is preferable. Within this range, excellent contamination of the hydrophilic layer surface with lipophilic substances such as fingerprint-like stains can be prevented without impairing the on-press developability.

In the present invention, at least one of the hydrophilic layer, the overcoat layer, and the undercoat layer contains a light-to-heat conversion agent that absorbs infrared rays and generates heat in order to increase the infrared absorption efficiency and improve the sensitivity. Can be done. As such a photothermal conversion agent, a wavelength range of 700 to 12
Any light absorbing substance having an absorption band in at least a part of 00 nm may be used, and various pigments, dyes and metal fine particles can be used.

Examples of pigments include commercially available pigments and color index (CI) handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977), and “Latest Pigment Application Technology” (CMC Publishing, 1986). And "printing ink technology" (CMC Publishing, 1984) can be used.

These pigments can be used after being subjected to a known surface treatment, if necessary, in order to improve the dispersibility in the layer to which the pigment is added. Surface treatment methods include a method of surface-coating a hydrophilic resin or a lipophilic resin, a method of attaching a surfactant, and a reactive substance (for example, silica sol, alumina sol, a silane coupling agent or an epoxy compound,
A method of bonding an isocyanate compound) to the surface of the pigment. The pigment to be added to the overcoat layer or the hydrophilic layer is desirably one whose surface is coated with a hydrophilic resin or silica sol so as to be easily dispersed in a water-soluble resin and not impair the hydrophilicity. The pigment particle size is 0.01μ
m to 1 μm, preferably 0.01 μm
More preferably, it is in the range of 0.5 to 0.5 μm. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Particularly preferred pigments include carbon black.

Examples of the dye include commercially available dyes and literatures (eg, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, 1975, “Chemical Industry”, May 1986, “Near-Infrared Absorbing Dyes” Known dyes described in "Development and Market Trend of Functional Dyes in the 90's", Chapter 2, Section 2.3 (1990), or patents can be used.
Specifically, azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes,
Infrared absorbing dyes such as carbonium dyes, quinone imine dyes, polymethine dyes and cyanine dyes are preferred.

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

Further, as a dye, US Pat. No. 5,156,
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645, JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, JP-A-59-84248, and JP-A-59-84248.
No. 84249, No. 59-146063, No. 59-14
No. 6061, pyranium compounds described in JP-A-59-216146, cyanine dyes described in US Pat. No. 4,283,475, pentamethine thiopyrylium salts described in U.S. Pat. 5-70
No. 2, a pyrylium compound, Eporin III-178, Epolite III-130, manufactured by Eporin Co., Ltd.
Epolite III-125 and the like are also preferably used.

Among these, a preferred dye to be added to the overcoat layer, the hydrophilic layer binder polymer or to the undercoat layer is a water-soluble dye, and specific examples are shown below.

[0111]

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[0112]

Embedded image

The photothermal conversion agent used together with the hydrophobic thermoplastic fine particles, the polymer fine particles having a thermoreactive functional group or the microcapsules of the present invention may be the above-mentioned infrared absorbing dye, but may be a lipophilic dye. Is more preferred. Specific examples include the following cyanine dyes.

[0114]

Embedded image

In the hydrophilic layer of the present invention, fine metal particles can be used as a photothermal conversion agent. Most of the metal fine particles are light-heat converting and self-heating, but preferred metal fine particles include Si, Al, Ti, V, Cr, and M.
n, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo,
Ag, Au, Pt, Pd, Rh, In, Sn, W, T
e, Pb, Ge, Re, and Sb alone or as an alloy, or fine particles of oxides or sulfides thereof. Among the metals constituting these metal fine particles, preferred metals are those which are liable to be coalesced by heat at the time of light irradiation, and have a melting point of about 1000 ° C. or less and have absorption in the infrared, visible or ultraviolet region, for example, Re, Sb, Te, Au, A
g, Cu, Ge, Pb and Sn. Particularly preferred are metal fine particles having a relatively low melting point and a relatively high absorbance to infrared rays, for example, Ag, Au, C
Among u, Sb, Ge and Pb, the most preferred elements include Ag, Au and Cu.

Further, for example, Re, Sb, Te, Au, A
g, Cu, Ge, Pb, Sn and other low melting point metal particles and self-heating metal particles such as Ti, Cr, Fe, Co, Ni, W and Ge. It may be made of a light-to-heat conversion material. Also, Ag,
It is also preferable to use a combination of a metal-type micro-piece and a metal-type micro-piece having a particularly large light absorption when made into a micro-piece such as Pt or Pd.

The size of these particles is preferably 10 μm.
m, more preferably 0.003 to 5 μm, particularly preferably 0.01 to 3 μm. The finer the particle, the lower the coagulation temperature, that is, the higher the light sensitivity in the heat mode, which is advantageous. However, it is difficult to disperse the particles.
Above μm, the resolution of the printed matter deteriorates.

In the case of a pigment or dye based photothermal conversion agent, the addition ratio can be up to 30% in the hydrophilic layer. It is preferably from 5 to 25%, particularly preferably from 7 to 25%.
20%. When added to the overcoat layer, 1 to 70% of the solid content of the overcoat layer, preferably 2 to 5%
0%. Although good sensitivity is obtained in this range, when the photothermal conversion agent is added to the overcoat layer, the amount of the photothermal conversion agent in the hydrophilic layer and the undercoat layer is reduced, or It can be added free.

When metal fine particles are used as the light-to-heat conversion agent, the amount added is at least 10% of the solid content of the hydrophilic layer.
It is preferably used at 20% or more, particularly preferably at 30% or more. Good sensitivity is obtained within this range.

The lithographic printing plate of the present invention forms an image by heat. Specifically, direct image-like recording using a thermal recording head or the like, scanning exposure using an infrared laser, high-intensity flash exposure such as a xenon discharge lamp, or infrared lamp exposure is used. Semiconductors that emit infrared light having a wavelength of 700 to 1200 nm are used. Exposure with a solid-state high-output infrared laser such as a laser or a YAG laser is preferable.

The lithographic printing plate precursor of the present invention, which has been image-exposed, can be mounted on a printing press without any further processing, and can be printed by an ordinary procedure using ink and fountain solution. These lithographic printing original plates are disclosed in Japanese Patent No. 293839.
As described in No. 8, after being mounted on a printing press cylinder, it can be exposed by a laser mounted on the printing press, and then developed with a dampening solution and / or ink. is there. These lithographic printing original plates can be used for printing after development using water or an appropriate aqueous solution as a developing solution.

[0122]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Synthesis Example of Polymer Fine Particles Having a Thermoreactive Group 7.5 g of allyl methacrylate, 7.5 g of butyl methacrylate, 200 ml of an aqueous solution of polyoxyethylene nonylphenyl ether (concentration: 9.84 × 10 ^-3 mol ^-1 )
Is added, and the system is replaced with nitrogen gas while stirring at 250 rpm. After the solution was brought to 25 ° C., cerium (I
V) Ammonium salt aqueous solution (concentration 0.984 × 10 ⁻³ m)
all ^-1 ) 10 ml are added. At this time, an aqueous solution of ammonium nitrate (concentration: 58.8 × 10 ⁻³ mol ⁻¹ ) is added to adjust the pH to 1.3 to 1.4. It was then stirred for 8 hours. The solid content of the liquid thus obtained was 6.7%, and the average particle size was 0.4 μm.

Production Example 1 of Microcapsules As oil phase components, 40 g of xylene diisocyanate, 10 g of trimethylolpropane diacrylate, 10 g of a copolymer of allyl methacrylate and butyl methacrylate (molar ratio: 7/3), Pionin A41C (manufactured by Takemoto Yushi)
0.1 g was dissolved in 60 g of ethyl acetate. 120 g of a 4% aqueous solution of PVA205 (Kuraray) as an aqueous phase component
Produced. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm using a homogenizer. Thereafter, 40 g of water was added, and the mixture was stirred at room temperature for 30 minutes and at 40 ° C. for 3 hours to evaporate ethyl acetate. The solid content concentration of the microcapsule solution thus obtained was 30%, and the average particle size was 0.5 μm.

Production Example 2 of Microcapsules Coronate L (manufactured by Nippon Polyurethane, one-to-three ratio of trimethylolpropane and 2,4-tolylene diisocyanate)
An oil component was prepared by uniformly dissolving 1.26 g of a molar adduct, containing 25% ethyl acetate) in 7.2 g of glycidyl methacrylate. Next, propylene glycol alginate (Duckloid LF, manufactured by Kibun Food Chemifa Ltd., number average molecular weight: 2) was added to 120 g of deionized water.
× 10 ⁵ ) 2 g, polyethylene glycol (PEG 40)
0, manufactured by Sanyo Chemical Co., Ltd.) to prepare an aqueous phase. Subsequently, the oil component and the aqueous phase were mixed and emulsified at 6000 rpm at room temperature using a homogenizer, and then mixed and emulsified.
The reaction was carried out at a temperature of 3 ° C. for 3 hours to obtain microcapsules having an average particle size of 1.8 μm.

Microcapsule Production Example 3 10 g of coronate L, 8 g of ethyl alcohol, 2 g of deionized water, 5 g of polyacrylamide
30 g of a 30% aqueous solution was placed in a container and shaken at room temperature for 1 hour with a paint shaker to produce microcapsules of isocyanate having fine particle surfaces blocked. The average size of the primary dispersed particles was 1.0 μm.

Production Example 4 of Microcapsules The same as Production Example 2 of microcapsules except that 0.3 g of a light-to-heat converting agent (dye IR-24 described in the present specification) was added to the oil component of Production Example 2 of Microcapsules. To produce microcapsules.

Manufacturing Example 1 of Support A 0.3 mm thick aluminum plate of JIS A 1050
The surface was sand-grained using a No. nylon brush and 800 mesh water suspension of pamistone, and then thoroughly washed with water. The plate is placed in a 10% aqueous sodium hydroxide solution at 70 ° C.
After etching by immersing in for 60 seconds, rinse with running water,
Further, it was neutralized and washed with 20% nitric acid, and then washed with water. This was subjected to electrolytic surface roughening treatment in an aqueous 1% nitric acid solution at an anode electricity of 300 C / dm ² using a sinusoidal alternating current under the condition of Va = 12.7 V. The center line average roughness (Ra) of the surface of the aluminum plate was measured to be 0.45.
μm. Subsequently, it was immersed in a 30% sulfuric acid aqueous solution and desmutted at 55 ° C. for 2 minutes.
DC electrolysis was performed in sulfuric acid at a current density of 5 A / dm ² for 45 seconds to form an anodized film (the support up to this anodization is referred to as support (O)).

Next, a treatment for enlarging the micropores of the formed anodized film was performed. One is the support (O)
Was immersed in 50 g / l sulfuric acid at 60 ° C. for 1 minute, washed with water and dried (the obtained sulfuric acid pore wide support having an average pore diameter of 16 nm is referred to as support (A)). The other is to wash the support (O) with water and then add 0.1 M sodium carbonate and 0.1 M
Molar sodium bicarbonate containing sodium hydroxide
The pore diameter was enlarged by immersing in an aqueous solution adjusted to H = 12 at 40 ° C. for 10 seconds, followed by washing with water and drying (the obtained alkaline pore wide support having an average pore diameter of 20 nm is referred to as support (B)).

Next, each of the supports (A) and (B) was subjected to a sealing treatment in a steam chamber saturated at 100 ° C. and 1 atm for 12 seconds to produce supports (A ′) and (B ′). . Furthermore, 2.0% of sodium silicate at 70 ° C.
The substrates (A ″) and (B ″) were immersed in an aqueous solution (amount of silicon attached by fluorescent X-ray analysis was 10 mg / m ² ), washed with water and dried, respectively. The average pore diameter of the supports (A ″) and (B ″) was 9 nm and 1 respectively.
1 nm. The micropore diameter of these supports was measured with an accelerating voltage of 1 using a scanning electron microscope S-900 manufactured by Hitachi, Ltd.
The average pore diameter was determined by observing the micropore surface under the conditions of 2 kV and no deposition.

Support Production Example 2 The support having been subjected to electrolytic surface roughening in Support Production Example 1 was replaced with 3
Dipped in 0% sulfuric acid aqueous solution and desmutted at 55 ° C for 2 minutes
After that, 1.5 A / dm in 15% sulfuric acid at 33 ° C. ^TwoCurrent
DC electrolysis at a density of 120 seconds to form an anodic oxide film
(The support up to this anodization is called support (O ').
Bu).

Next, using this support (O ′), one was immersed in 50 g / l sulfuric acid at 60 ° C. for 1 minute, washed with water and dried, and further dried at 70 ° C. with 2.0 g of sodium silicate. % Aqueous solution (silicon deposition amount 10 mg / m ² )
After washing with water and drying, a support (C) having an average pore diameter of 9 nm was obtained. The other is to wash the support (O ') with water and then immerse it in an aqueous solution containing 0.1 M sodium carbonate and 0.1 M sodium bicarbonate and adjusted to pH = 12 with sodium hydroxide at 40 ° C for 10 seconds. The pore diameter was enlarged by this, washed with water and dried, and further immersed in a 2.0% aqueous solution of sodium silicate at 70 ° C. (silicon adhesion amount 10 mg / m ² ).
After washing with water and drying, a support (D) having an average pore diameter of 11 nm was obtained.

Further, 0.2 μm of polyacrylic acid (weight average molecular weight: 250,000) was placed on the support obtained as described above.
10 g of undercoating liquid consisting of 5% methanol solution
/ M was applied at ^2, a support having a 60 seconds dry to a dry coating amount of 25 mg / m ² primed with 100 ℃ (C ')
(D ') was produced respectively.

Preparation Example 1 of Comparative Support The anodized support (O ′) described in Preparation Example 2 of the support
Was further immersed in a 2.0% aqueous solution of sodium silicate at 70 ° C. (silicon adhesion amount: 10 mg / m ² ), washed with water and dried to obtain a support for comparison (i). The average pore size of this support was 4 nm.

Preparation Example 2 of Support for Comparative Example After the anodized support (O) described in Preparation Example 1 of the support was washed with water, it was added with 0.1 mol sodium carbonate and 0.1 mol sodium bicarbonate, The pore diameter was enlarged by immersing in an aqueous solution adjusted to pH = 13 with sodium oxide at 60 ° C. for 20 seconds, followed by washing with water and drying. Further, immersion treatment (amount of silicon attached: 10 mg / m ² ) with a 2.0% aqueous solution of sodium silicate at 70 ° C. was performed, followed by washing and drying to obtain a support for comparison (ii). The average pore size of this support was 42 nm.

Examples 1 to 10 and Comparative Examples 1 to 2 The hydrophilic layer coating solution 1 prepared as described below was coated on the support obtained in the above Production Example at a coating solution amount of 30 g / m ² .
After drying at 100 ° C. for 60 seconds, the dry coating amount is 1.5 g / m ^2.
Was provided. The support used in each example is shown in Table 1.

(Preparation of Hydrophilic Layer Coating Solution 1) Polyoxyethylene nonyl phenyl ether was added to 8 g of a 20% dispersion of polystyrene (Tg 100 ° C., average particle diameter 90 nm) dispersed in deionized water with a nonionic surfactant. 024 g and 15.46 g of deionized water are continuously added, and finally, 8 g of a 5% aqueous solution of polyvinyl alcohol (PVA205 manufactured by Kuraray Co., Ltd.) is added with stirring.

On this hydrophilic layer, an overcoat layer coating solution OC-1 having the following composition was applied at a coating solution amount of 20 g / m ² .
After drying at 100 ° C. for 60 seconds, a dry coating weight of 1.0 g /
A lithographic printing plate having an m ² overcoat layer was prepared.

(Overcoat Layer Coating Solution OC-1) Polyacrylic acid (weight-average molecular weight: 25,000) 1 g 20% ethanol dispersion of carbon black stabilized with a nonionic surfactant 2.5 g Methanol 26.5 g

The lithographic printing plate thus obtained was used as a trend setter 3244 VFS (manufactured by Creo Corporation, 83 W of 40 W).
The plate was mounted on a plate setter equipped with a 0 nm semiconductor laser, and exposed under the conditions of an outer drum rotation speed of 100 rpm, a plate surface energy of 200 mJ / cm ² , and a resolution of 2400 dpi. The exposed plate was directly mounted on a Harris Aurelia printing press without further processing, and was
Printing was performed using a fountain solution composed of a 0% by volume isopropyl alcohol aqueous solution and ink. The results are shown in Table 1 together with the measurement results of the average pore diameter of the support. In the evaluation of printing stains in the table, ○ is good, Δ is an acceptable level, × is not acceptable, ○ △
Indicates between good and acceptable.

[0141]

[Table 1]

From the above results, it was found that the lithographic printing plate according to the present invention is excellent in both printing durability and stain resistance in printing.

Examples 11 to 12 and Comparative Examples 3 and 4 Instead of the polystyrene fine particles used in the hydrophilic layer coating solution 1 of Examples 1 to 10 and Comparative Examples 1 and 2, polymethyl methacrylate fine particles (Tg 90 ° C., average (Particle diameter 80nm)
Was used. Except for this, lithographic printing original plates were prepared in the same manner as in Examples 1 to 10 and Comparative Examples 1 and 2. Next, exposure was performed in the same manner as in Examples 1 to 10,
Printed. The results are shown in Table 2.

[0144]

[Table 2]

The above results also show that the lithographic printing plate according to the present invention is excellent in both printing durability and resistance to staining in printing.

Examples 13 and 14 In Example 13, the support (C ′) was used, and in Example 14, (D ′) was used. Further, 0.4 g of the photothermal conversion agent (D) was added to the hydrophilic layer coating solution 1 of Example 1. Dye IR-1 described herein
The coating solution to which 1) was added was used. Otherwise, Example 1
In the same manner as in the above, a lithographic printing original plate was produced. Next, when exposure and printing were performed in the same manner as in Example 1, from 1 to 2 million good printed materials free of printing stains were obtained from both lithographic printing original plates.

Examples 15 to 24 and Comparative Examples 5 to 6 The hydrophilic layer coating solution 3 having the following composition was coated on an aluminum support shown in Table 3 so that the dry coating amount was 0.5 g / m ^2. It was applied and dried in an oven at 100 ° C. for 60 seconds to prepare a lithographic printing original plate.

(Hydrophilic Layer Coating Solution 3) Polymer Fine Particles Having a Thermoreactive Group in Synthesis Example 5 g in terms of solid content Polyhydroxyethyl acrylate (weight average molecular weight: 25,000) 0.5 g Light-to-heat converting agent (described in this specification) IR-11) 0.3 g water 100 g

The lithographic printing plate thus obtained, which can be developed on the press, is exposed by a trend setter 3244 VFS under the conditions of an output of 9 W, an outer drum rotation speed of 210 rpm, a plate surface energy of 100 mJ / cm ² , and a resolution of 2400 dpi. Without processing, the printer was mounted on a cylinder of a printing machine SOR-M manufactured by Heidelberg Co., and supplied with dampening water, ink was supplied, and paper was further supplied to perform printing. On-press development was possible for all printing plates without any problems, and printing was possible. Table 3 shows the print results obtained for each printing plate.
It described in.

[0150]

[Table 3]

From the above results, it was found that the lithographic printing plate precursor of the present invention had good on-press developability and good printing stains and printing durability.

Examples 25 to 34 and Comparative Examples 7 to 8 Using the following hydrophilic layer coating solution 4 containing the microcapsules obtained in Production Example 1 of microcapsules, lithographic printing was performed using a combination of supports shown in Table 4. A master plate was created. Drying of the hydrophilic layer was performed in an oven at 100 ° C. for 60 seconds, and the dry coating amount was 0.7 g / m ² .

(Hydrophilic Layer Coating Solution 4) Microcapsules of Production Example 5 5 g in terms of solids trimethylolpropane triacrylate 3 g Infrared absorbing dye (IR-11 described in this specification) 0.3 g Water 60 g 1-methoxy-2 -Propanol 40 g The lithographic printing plate thus prepared was applied to a Fuji Photo Film Co., Ltd. equipped with a multi-channel laser head.
Luxel T-9000CTP, output 250mW per beam, external drum rotation speed 800rpm
m and a resolution of 2400 dpi. Printing was performed in the same manner as in Example 1, and the printing results are shown in Table 4.

[0154]

[Table 4]

Examples 35 to 40 A hydrophilic layer was provided by a combination of a support and a hydrophilic layer coating solution shown in Table 5, and an overcoat layer coating solution OC-2 was applied thereon to prepare a lithographic printing original plate. did. The hydrophilic layer coating solution is thoroughly stirred in advance with a paint shaker at room temperature for 30 minutes.
It was applied using a blade coater and then dried. The dry coating thickness of the hydrophilic layer is shown in Table 5. The dry coating amount of the overcoat layer was about 0.6 g / m ² .

(Hydrophilic Layer Coating Solution 5) 10% aqueous solution of hydrophilic resin (1) 20.0 g Microcapsules of Production Example 2 (in dispersion) 80.0 g 3% aqueous solution of alginic acid ester 300 g

Here, the hydrophilic resin (1) has a polyacrylic acid (julymer AC10MP, manufactured by Nippon Pure Chemical Co., Ltd.) number average molecular weight of 80,000, and the alginate ester is propylene glycol alginate (Kibun Food Chemifa Co., Ltd.). Dacroid LF).

(Hydrophilic Layer Coating Solution 6) 15% aqueous solution of hydrophilic resin (2) 12 g Microcapsules of Production Example 3 (in dispersion) 6 g Calcium carbonate 1 g Water 19 g

Here, the hydrophilic resin (2) is a copolymer of 2-hydroxyethyl methacrylate / acrylamide / acrylic acid (weight ratio 1/4/4) and has a number average molecular weight of 1
100,000.

(Hydrophilic layer coating liquid 7) 10% aqueous solution of hydrophilic resin (1) 20.0 g Microcapsules of Production Example 4 (in dispersion) 80.0 g 3% aqueous solution of alginic acid ester 300 g

(Coating solution OC-2 for overcoat layer) Polyacrylic acid (weight average molecular weight 25,000) 1 g Light-to-heat converting agent (dye IR-11 described in this specification) 0.2 g Polyoxyethylene nonylphenyl ether 0 .25g Water 19g

The lithographic printing plate prepared as described above was
Exposure and printing were performed in the same manner as in Example 7. Table 5 shows the results.

[0163]

[Table 5]

Example 17 A solution composed of 115 g of a 0.15% aqueous solution of gum arabic and 48 g of methanol was applied on a support (B ″) at 180 rpm using a rotary coating machine (whiler).
After drying at 100 ° C. for 1 minute, an undercoat layer was provided. in addition,
A lithographic printing original plate was prepared using the hydrophilic layer coating solution 5 and the overcoat layer coating solution (OC-2). Next, when exposure and printing were performed in the same manner as in Example 7, 15.0
00 good prints were obtained.

[0165]

According to the present invention, an on-press development type lithographic printing plate precursor that can be mounted on a printing press as it is after exposure and has good on-press developability, and is free from contamination during printing. A planographic printing plate having good printing durability can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/11 G03F 7/11

Claims (8)

[Claims] 1. A lithographic printing plate comprising an aluminum support having an anodized film and a hydrophilic layer containing a hydrophobizing precursor and becoming hydrophobic by heat, wherein the average of the micropores of the anodized film is obtained. A lithographic printing plate having a pore diameter of 6 to 40 nm. 2. The micropores of the anodic oxide film are subjected to an enlarging treatment or an enlarging treatment followed by a sealing treatment,
An original plate for lithographic printing, comprising a hydrophilic layer containing a hydrophobizing precursor and becoming hydrophobic by heat on an aluminum support having an average pore diameter of micropores of 6 to 40 nm. 3. The hydrophobic precursor is melted by heat, (a) hydrophobic thermoplastic fine particles, (b) polymer fine particles having a thermoreactive functional group, and (c) compound having a thermoreactive functional group. 3. The lithographic printing plate according to claim 1, wherein the lithographic printing plate is at least one component selected from microcapsules containing 4. The lithographic printing plate according to claim 1, further comprising a water-soluble overcoat layer on the hydrophilic layer. 5. The lithographic printing plate according to claim 1, further comprising an undercoat layer between the support and the hydrophilic layer. 6. The lithographic printing plate according to claim 1, wherein at least one of the hydrophilic layer, the overcoat layer and the undercoat layer contains a photothermal conversion agent. 7. A support having an anodized film,
Phosphoric acid, a mixture of both, or a micropore enlargement treatment of the anodic oxide film immersed in an alkaline aqueous solution having a pH of 11 to 13, or an enlargement treatment followed by a sealing treatment to make the average pore diameter of the micropores 6 to 40 nm. From microcapsules containing (a) hydrophobic thermoplastic fine particles that melt by heat, (b) polymer fine particles having a thermoreactive functional group, and (c) a compound having a thermoreactive functional group on an aluminum support. A method for producing a lithographic printing original plate, comprising providing a hydrophilic layer containing at least one selected component. 8. The lithographic printing plate according to any one of claims 1 to 6, wherein the lithographic printing plate is image-exposed with a laser beam and mounted on a printing machine as it is, or printed on a printing machine after being mounted on the printing machine. A method for making and printing a lithographic printing original plate, wherein the plate is exposed by a laser beam and printed as it is.