JP2009058969A - Method for producing lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a lithographic printing plate from a lithographic printing plate precursor which can be subjected to heat mode recording and simple development processing and in particular to provide a simple development processing method capable of efficiently and reliably removing a non-image area of a thermosensitive layer of a lithographic printing plate precursor provided with the thermosensitive layer containing microcapsules including a lipophilic compound, preferably a compound having a thermally reactive functional group. <P>SOLUTION: The method for producing a lithographic printing plate includes performing image recording in the lithographic printing plate precursor provided with a thermosensitive layer containing microcapsules including a lipophilic compound on a support having a hydrophilic surface, and removing a non-image area of the thermosensitive layer by rubbing the plate surface with a rubbing member in the presence of a processing solution. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for preparing a lithographic printing plate from a direct heat-sensitive lithographic printing plate precursor. More specifically, the present invention relates to a simple development processing method for producing a lithographic printing plate from a heat-sensitive lithographic printing plate precursor capable of recording an image by scanning exposure based on a digital signal.

  In general, a lithographic printing plate is composed of an oleophilic image portion that receives ink in the printing process and a hydrophilic non-image portion that receives dampening water. As such a lithographic printing plate, a PS plate in which an oleophilic photosensitive resin layer is provided on a hydrophilic support has been widely used. The plate making process in the conventional PS plate requires an operation of dissolving and removing the non-image area with a highly alkaline developing solution after exposure, and simplifies or eliminates such additional wet processing. This is one problem that has been desired to be improved with respect to the prior art. Particularly in recent years, disposal of the waste liquid discharged with wet processing has become a major concern for the entire industry due to consideration of the global environment, and the demand for improvement in this aspect has become even stronger.

  On the other hand, as another trend in this field in recent years, digitization technology that electronically processes, stores, and outputs image information using a computer has become widespread. Various new image output methods have been put into practical use. Along with this, a computer that carries a digitized image information in a high-convergence radiation such as laser light, scans and exposes the original plate with this light, and directly produces a printing plate without using a lith film. To-plate technology is drawing attention.

Among them, since solid-state lasers such as semiconductor lasers and YAG lasers have recently become available at low cost, plate-making methods using high-power density exposure using high-power lasers are promising. It has come to be. In this method, a large amount of light energy is concentrated on the exposure area during an instantaneous exposure time, and the light energy is efficiently converted into thermal energy, and the heat changes chemical changes, phase changes, forms and structures. A thermal change such as a change is caused and the change is used for image recording. That is, image information is input by light energy such as laser light, but image recording is recorded by a reaction by heat energy.
Usually, such a recording method using heat generated by high power density exposure is called heat mode recording, and changing light energy to heat energy is called photothermal conversion.

  Among such heat mode recording lithographic printing plate precursors, one promising method suitable for simple development processing is to image a hydrophilic layer in which hydrophobic thermoplastic polymer particles are dispersed in a hydrophilic binder polymer. A heat-sensitive lithographic printing plate precursor for forming a heat-sensitive layer. When heat is applied to the heat sensitive layer, the hydrophobic thermoplastic polymer particles are fused and the surface of the hydrophilic heat sensitive layer is converted into an oleophilic image area.

  For example, Patent Documents 1 to 3 disclose lithographic printing plate precursors in which a thermosensitive layer in which fine particles of a thermoplastic hydrophobic polymer are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support. In these publications, a printing press, dampening water and / or ink are supplied to the lithographic printing plate precursor plate after infrared laser exposure to form fine particles of thermoplastic hydrophobic polymer by heat. It is described that development (so-called development on a printing press) can be performed.

  However, it is difficult to sufficiently remove the heat-sensitive layer of the non-image portion containing such thermoplastic hydrophobic fine particles by on-press development with dampening water or oil-based ink. Remains and causes stains in printing.

Japanese Patent No. 2938397 JP-A-9-127683 WO99 / 10186 pamphlet

Accordingly, an object of the present invention is to provide a method for producing a lithographic printing plate from a lithographic printing plate precursor capable of heat mode recording and simple development processing.
Still another object is to efficiently and efficiently form a heat-sensitive layer in a non-image area of a lithographic printing plate precursor provided with a heat-sensitive layer containing a microcapsule containing a lipophilic compound, preferably a compound having a heat-reactive functional group. It is an object of the present invention to provide a simple development processing method that can be reliably removed.

In order to solve the above problems, the present inventor removed the heat-sensitive layer containing the microcapsules encapsulating the lipophilic compound provided on the support by rubbing the plate surface with a rubbing member in the presence of the treatment liquid. The present invention has been completed by finding out that it can be efficiently and surely implemented.
That is, the present invention is as follows.

(1) Image recording on a lithographic printing plate precursor provided with a thermosensitive layer containing a microcapsule encapsulating a lipophilic compound, preferably a compound having a heat-reactive functional group, on a support having a hydrophilic surface. A method for producing a lithographic printing plate, comprising: a step of removing a heat-sensitive layer in a non-image area by rubbing the plate surface with a rubbing member in the presence of a treatment liquid after the step.

The preferred embodiments of the present invention will be further described below.
(2) The method for producing a lithographic printing plate as described in (1) above, wherein a lithographic printing plate having an overcoat layer removable by a treatment liquid is used on the thermosensitive layer.
(3) In the above (1) or (2), the heat-sensitive layer removal of the non-image portion of the lithographic printing plate precursor on which image recording has been performed is performed by an automatic processor equipped with a rubbing member. A method for producing the described lithographic printing plate.

The lithographic printing plate precursor used in the method of the present invention contains a microcapsule containing at least a lipophilic compound, preferably a compound having a heat-reactive functional group, in a heat-sensitive layer on a hydrophilic support, and a computer or the like. Based on the digital signal of the above, a compound having a heat-reactive functional group or a radical polymerizable compound contained in the microcapsule is formed in the image recording portion of the heat sensitive layer by heat generated by image-like heating or photothermal conversion of laser light scanning. When the reaction occurs, and preferably, the microcapsule particles are melted and fused, and the heat-sensitive layer contains a hydrophilic resin, the resin becomes hydrophobic by crosslinking and water resistance.
The method for preparing a lithographic printing plate of the present invention is to efficiently and efficiently form a heat-sensitive layer in a non-image area by rubbing the lithographic printing plate precursor after heat mode image recording with a rubbing member in the presence of a treatment liquid. An excellent lithographic printing plate that can be surely removed and that can prevent stains at the time of printing and printing can be obtained by a simple development processing method.

  According to the present invention, it is possible to efficiently and surely remove the heat-sensitive layer in the non-image area of the lithographic printing plate precursor capable of heat mode recording by a simple development processing method. Can be prevented.

The method for preparing the planographic printing plate of the present invention will be described in detail below.
A lithographic printing plate precursor to which the method for preparing a lithographic printing plate of the present invention is applied comprises a microcapsule encapsulating a lipophilic compound, preferably a compound having a thermoreactive functional group, on a support having a hydrophilic surface. It has the heat-sensitive layer to contain.
As described above, the heat-sensitive layer of the lithographic printing plate precursor for use in the present invention preferably contains a microcapsule encapsulating a lipophilic compound, but as described later, in addition to the microcapsule, As needed, it is comprised including the compound which starts or accelerates | stimulates these reactions, hydrophilic resin, a photothermal conversion agent, etc., and also contains other structural components as needed.

The method for producing a lithographic printing plate according to the present invention comprises removing the heat-sensitive layer in the non-image area by rubbing the plate surface with a rubbing member in the presence of a treatment liquid after image recording is performed on the lithographic printing plate precursor. Including a process.
The removal of the heat-sensitive layer in the non-image area in the present invention can be preferably carried out by an automatic processor equipped with a processing liquid supply means and a rubbing member. Although it does not specifically limit as an automatic processor, The automatic processor which uses a rotating brush roll as a rubbing member is especially preferable.
As shown in the layout diagram of the automatic processor suitable for the development processing of the present invention in FIG. 1, the processing liquid 10 is sent to the spray pipe 5 by the circulation pump 11, showered, and the rotating brush roll 1 and the plate surface 12 (lithographic plate). The lithographic printing plate is produced by the process of removing the heat-sensitive layer in the non-image area by an automatic processor that supplies the printing plate to the printing original plate and rubs the plate surface 12 with the rotating brush roll 1.

Hereinafter, each configuration of the lithographic printing plate precursor to which the lithographic printing plate preparation method of the present invention is applied will be described.
(Support having a hydrophilic surface)
The support having a hydrophilic surface used in the present invention includes a support that is hydrophilic per se, a support that has been hydrophilized, or a support that has a hydrophilic layer on the support. including.

  The support used for the lithographic printing plate precursor of the present invention is a dimensionally stable plate-like material, for example, paper, paper laminated with plastic (for example, polyethylene, polypropylene, polystyrene, etc.), Metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene naphthalate, polyethylene, polystyrene , Polypropylene, polycarbonate, polyvinyl acetal, etc.), the above-mentioned plastic film in which a pigment is dispersed, the above-mentioned plastic film having cavities, the paper laminated or vapor-deposited with metal as described above, or the plastic film Beam and the like are included.

The support used for the lithographic printing plate precursor according to the invention is preferably a polyester film or an aluminum plate.
Among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is at most 10% by weight.
Particularly suitable aluminum in the present invention is pure aluminum. However, since completely pure aluminum is difficult to manufacture in terms of refining technology, it may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and particularly preferably 0.2 mm to 0.3 mm.

Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired.
The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.

The surface roughening by the method as described above is preferably performed in such a range that the center line surface roughness (Ha) of the surface of the aluminum plate is 0.3 to 1.0 μm.
The roughened aluminum plate is subjected to alkali etching treatment using an aqueous solution of potassium hydroxide or sodium hydroxide as necessary, and further neutralized, and then anodized to increase wear resistance as desired. Processing is performed.
As the electrolyte used for anodizing the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

The anodizing treatment conditions vary depending on the electrolyte used and cannot be specified in general, but in general, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ^2. A voltage of 1 to 100 V and an electrolysis time of 10 seconds to 5 minutes are suitable.
The amount of the anodic oxide film is preferably 1.0 to 5.0 g / m ² , and particularly preferably 1.5 to 4.0 g / m ² .
If it is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image part of the lithographic printing plate is likely to be scratched, so-called “scratch stains” where ink adheres to the scratched part during printing. It tends to occur.
After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. The hydrophilization treatment used in the present invention is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are alkali metal silicate (such as aqueous sodium silicate) methods. In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, it is disclosed in potassium fluoride zirconate disclosed in Japanese Patent Publication No. 36-22063 and US Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid is used.

When a non-conductive material such as a polyester film is used for the support of the present invention, it is preferable to provide an antistatic layer on the heat-sensitive layer side, the opposite side, or both sides of the support.
In the case where the antistatic layer is provided between the support and the hydrophilic layer described later, it contributes to improving the adhesion of the hydrophilic layer.
As the antistatic layer, a polymer layer in which metal oxide fine particles and a matting agent are dispersed can be used.

Examples of the material of the metal oxide particles used for the antistatic layer include SiO ₂ , ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , MgO, BaO, MoO ₃ , V ₂ O _5, and these A composite oxide and / or a metal oxide further containing a different atom in these metal oxides can be given. These may be used alone or in combination.
As the metal _{oxide, SiO 2, ZnO, SnO 2} , Al 2 O 3, TiO 2, In 2 O 3, MgO is preferred.
As an example containing a small amount of hetero atoms, Al or In with respect to ZnO, Sb, Nb or halogen elements with respect to SnO ₂ , and hetero atoms such as Sn with respect to In ₂ O ₃ of 30 mol% or less, preferably 10 What doped the quantity below mol% can be mentioned.
The metal oxide particles are preferably contained in the antistatic layer in the range of 10 to 90% by weight. The average particle diameter of the metal oxide particles is preferably in the range of 0.001 to 0.5 μm. The average particle diameter here is a value including not only the primary particle diameter of the metal oxide particles but also the particle diameter of the higher order structure.

The matting agent that can be used for the antistatic layer preferably includes inorganic or organic particles having an average particle size of 0.5 to 20 μm, more preferably an average particle size of 1.0 to 15 μm. .
Examples of the inorganic particles include metal oxides such as silicon oxide, aluminum oxide, titanium oxide, and zinc oxide, and metal salts such as calcium carbonate, barium sulfate, barium titanate, and strontium titanate. Examples of the organic particles include cross-linked particles of polymethyl methacrylate, polystyrene, polyolefin, and copolymers thereof.
The matting agent is preferably contained in the antistatic layer in the range of 1 to 30% by weight.

Examples of polymers that can be used for the antistatic layer include proteins such as gelatin and casein, cellulose compounds such as carboxymethylcellulose, hydroxyethylcellulose, acetylcellulose, diacetylcellulose, and triacetylcellulose, dextran, agar, sodium alginate, and starch derivatives. And synthetic polymers such as saccharides such as polyvinyl alcohol, polyvinyl acetate, polyacrylic acid ester, polymethacrylic acid ester, polystyrene, polyacrylamide, polyvinylpyrrolidone, polyester, polyvinyl chloride, polyacrylic acid and polymethacrylic acid. .
The polymer is preferably contained in the antistatic layer in the range of 10 to 90% by weight.
The thickness of the antistatic layer is preferably 0.01 to 1 μm.

  In order to make the surface of the support hydrophilic, the hydrophilic layer that can be provided on the support of the present invention includes, for example, an organic hydrophilic matrix obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer. And a layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or an inorganic thin film having a surface containing a metal oxide However, an inorganic thin film having a surface containing an inorganic hydrophilic matrix or metal oxide obtained by sol-gel conversion is preferable.

As the crosslinking reaction used for forming the organic hydrophilic matrix of the hydrophilic layer of the present invention, covalent bond formation by heat or light, or ionic bond formation by a polyvalent metal salt is possible.
The organic hydrophilic polymer used in the present invention is preferably a polymer having a functional group that can be used for a crosslinking reaction.
Preferred functional groups include, for example, —OH, —SH, —NH ₂ , —NH—, —CO—NH ₂ , —CO—NH—, —O—CO—NH—, —NH—CO—NH—, ^{-CO-OH, -CO-O -} , - CO-O -, -CS-OH, -CO-SH, -CS-SH, -SO 3 H, -SO 2 (O -), - PO 3 H 2 , —PO (O ⁻ ) ₂ , —SO ₂ —NH ₂ , —SO ₂ —NH—, —CH═CH ₂ , —CH═CH—, —CO—C (CH ₃ ) ═CH ₂ , —CO— CH = CH ₂ , —CO—CH ₂ —CO—, —CO—O—CO—, and the following functional groups may be mentioned.

  In particular, a hydroxyl group, an amino group, a carboxyl group, and an epoxy group are preferable.

  As such an organic hydrophilic polymer of the present invention, a known water-soluble binder can be used. For example, modified polyvinyl alcohol such as polyvinyl alcohol (polyvinyl acetate having a saponification degree of 60% or more), carboxy-modified polyvinyl alcohol or the like. Alcohol, starch and derivatives thereof, carboxymethylcellulose and salts thereof, cellulose derivatives such as hydroxyethylcellulose, casein, gelatin, gum arabic, polyvinylpyrrolidone, vinyl acetate-crotonic acid copolymer and salts thereof, styrene-maleic acid copolymer And its salts, polyacrylic acid and its salts, polymethacrylic acid and its salts, polyethylene glycol, polyethyleneimine, polyvinylphosphonic acid and its salts, polystyrene sulfonic acid and its salts, poly (methacryloyl) Carboxy acid) and salts thereof, polyvinyl sulfonic acid and salts thereof, poly (methacryloyloxyethyl trimethyl ammonium chloride), polyhydroxyethyl methacrylate, polyhydroxyethyl acrylate, polyacrylamide and the like. These polymers may be copolymers as long as hydrophilicity is not impaired, and may be used alone or in combination of two or more. The amount used is 20% to 99% by weight, preferably 25% to 95% by weight, more preferably 30% to 90% by weight, based on the total solid content of the hydrophilic layer.

In the present invention, the organic hydrophilic polymer can be crosslinked with a known crosslinking agent.
Known crosslinking agents include polyfunctional isocyanate compounds, polyfunctional epoxy compounds, polyfunctional amine compounds, polyol compounds, polyfunctional carboxyl compounds, aldehyde compounds, polyfunctional (meth) acrylic compounds, polyfunctional vinyl compounds, polyfunctional mercapto compounds. , Polyvalent metal salt compounds, polyalkoxysilane compounds and hydrolysates thereof, polyalkoxytitanium compounds and hydrolysates thereof, polyalkoxyaluminum compounds and hydrolysates thereof, polymethylol compounds, polyalkoxymethyl compounds, etc. It is also possible to add a known reaction catalyst to promote the reaction.
The amount used is 1% to 50% by weight, preferably 3% to 40% by weight, more preferably 5% to 35% by weight, based on the total solid content in the coating solution of the hydrophilic layer. .

  In the system capable of sol-gel conversion that can be used for forming the inorganic hydrophilic matrix of the hydrophilic layer of the present invention, the bonding group coming out of the polyvalent element forms a network structure through oxygen atoms, At the same time, the polyvalent metal also has unbonded hydroxyl groups and alkoxy groups, and is a polymer having a resinous structure in which these are mixed, and is in a sol state when there are many alkoxy groups and hydroxyl groups. As bonding proceeds, the network-like resin structure becomes stronger. In addition, when a part of the hydroxyl group is bonded to the solid fine particles, the surface of the solid fine particles is modified to change the hydrophilicity. The polyvalent binding element of the compound having a hydroxyl group or an alkoxy group that performs sol-gel conversion is aluminum, silicon, titanium, zirconium, and the like. Any of these can be used in the present invention, but the following are most preferably used. A sol-gel conversion system using siloxane bonds that can be formed will be described. Sol-gel conversion using aluminum, titanium, and zirconium can be performed by replacing silicon described below with each element.

That is, a system including a silane compound having at least one silanol group capable of sol-gel conversion is particularly preferably used.
Hereinafter, a system using sol-gel conversion will be further described. The inorganic hydrophilic matrix formed by sol-gel conversion is preferably a resin having a siloxane bond and a silanol group, and a coating liquid which is a sol system containing a silane compound having at least one silanol group is applied. During drying and aging, hydrolysis and condensation of silanol groups proceed to form a siloxane skeleton structure, and gelation proceeds.
In addition, the above organic hydrophilic polymer and crosslinking agent are added to the gel structure matrix for the purpose of improving physical performance such as film strength and flexibility, improving coatability, and adjusting hydrophilicity. It is also possible.
A siloxane resin forming a gel structure is represented by the following general formula (I), and a silane compound having at least one silanol group is obtained by hydrolysis of a silane compound represented by the following general formula (II): The partial hydrolyzate of the silane compound of the general formula (II) does not necessarily need to be a single hydrolyzate. In general, the silane compound may consist of a partially hydrolyzed oligomer, or a mixed composition of the silane compound and its oligomer. There may be.

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

Formula (II)
(R ₀ ) _n Si (Y) _4-n

In general formula (II), R ₀ represents a hydroxyl group, a hydrocarbon group or a heterocyclic group. Y represents a hydrogen atom, a halogen atom (representing a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), —OR ₁ , —OCOR ₂ or —N (R ₃ ) (R ₄ ) (R ₁ , R _2). Each represents a hydrocarbon group, R ₃ and R ₄ may be the same or different and each represents a hydrogen atom or a hydrocarbon group), and n represents 0, 1, 2, or 3.

The hydrocarbon group or heterocyclic group represented by R _{0 in} the general formula (II) is, for example, a linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted (for example, a methyl group or an ethyl group). , Propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, etc .; these groups include halogen atoms (chlorine atom, fluorine atom, bromine group) Atom), hydroxy group, thiol group, carboxy group, sulfo group, cyano group, epoxy group, -OR 'group (R' is methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, octyl group) Decyl group, propenyl group, butenyl group, hexenyl group, octenyl group, 2-hydroxyethyl group, 3-chloropropyl group, 2-cyanoethyl group, N, N-dimethylaminoethyl 1-bromoethyl group, 2- (2-methoxyethyl) oxyethyl group, 2-methoxycarbonylethyl group, 3-carboxypropyl group, benzyl group, etc.), -OCOR ″ group (R ″ represents the above R , -COOR ″ group, —COR ″ group, —N (R ′ ″) (R ′ ″) group (R ′ ″ represents a hydrogen atom or R ′ and Represents the same contents, and may be the same or different), —NHCONHR ″ group, —NHCOOR ″ group, —Si (R ″) ₃ group, —CONHR ′ ″ group, —NHCOR ″ group, etc. These substituents may be substituted in plural in the alkyl group),

C2-C12 linear or branched alkenyl group which may be substituted (for example, vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, octenyl group, decenyl group, dodecenyl group, etc. Examples of the group substituted by the group include those having the same contents as the group substituted by the alkyl group), an aralkyl group having 7 to 14 carbon atoms which may be substituted (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, etc .; examples of the group substituted by these groups include those having the same content as the group substituted by the alkyl group, and a plurality of substituted groups. You may)

C5-C10 alicyclic group which may be substituted (for example, cyclopentyl group, cyclohexyl group, 2-cyclohexylethyl group, 2-cyclopentylethyl group, norbornyl group, adamantyl group, etc.) Examples of the group include those having the same content as the substituent of the alkyl group, and may be substituted in plural, or an aryl group having 6 to 12 carbon atoms (for example, phenyl group, naphthyl group). And the substituent may be the same as the group substituted with the alkyl group, or may be substituted in plural)
Or a heterocyclic group which may be condensed, containing at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom (for example, the heterocyclic ring includes a pyran ring, a furan ring, a thiophene ring, a morpholine ring) , Pyrrole ring, thiazole ring, oxazole ring, pyridine ring, piperidine ring, pyrrolidone ring, benzothiazole ring, benzoxazole ring, quinoline ring, tetrahydrofuran ring, etc., which may contain a substituent. A group having the same content as a group substituted by an alkyl group may be mentioned, and a plurality of groups may be substituted).

Examples of the substituent of the —OR ₁ group, —OCOR ₂ group, or —N (R ₃ ) (R ₄ ) group of Y in the general formula (II) represent the following substituents.
In the —OR ₁ group, R ₁ is an optionally substituted aliphatic group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, pentyl group, octyl group, Nonyl, decyl, propenyl, butenyl, heptenyl, hexenyl, octenyl, decenyl, 2-hydroxyethyl, 2-hydroxypropyl, 2-methoxyethyl, 2- (methoxyethyloxo) ethyl Group, 1- (N, N-diethylamino) ethyl group, 2-methoxypropyl group, 2-cyanoethyl group, 3-methyloxapropyl group, 2-chloroethyl group, cyclohexyl group, cyclopentyl group, cyclooctyl group, chlorocyclohexyl group , Methoxycyclohexyl group, benzyl group, phenethyl group, dimethoxybenzyl group, methyl base Benzyl group, bromobenzyl group, etc.).

In the —OCOR ₂ group, R ₂ is an aliphatic group having the same contents as R ₁ or an aromatic group having 6 to 12 carbon atoms which may be substituted (the aromatic group is exemplified by the aryl group in R above). The same as the above).
In the —N (R ₃ ) (R ₄ ) group, R ₃ and R ₄ may be the same or different from each other, and each is a hydrogen atom or an aliphatic group having 1 to 10 carbon atoms which may be substituted ( for example, represent the like) the same contents as R ₁ -OR ₁ group of said. More preferably, the total number of carbon atoms of R ₃ and R ₄ is 16 or less.
Specific examples of the silane compound represented by the general formula (II) include the following, but are not limited thereto.

Tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetra n-propylsilane, tetra t-butoxysilane, tetra n-butoxysilane, dimethoxydiethoxysilane, methyltrichlorosilane, methyltri Bromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltrit-butoxysilane, ethyltrichlorosilane, ethyltribromosilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, Ethyltri-t-butoxysilane, n-propyltrichlorosilane, n-propyltribromosilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, -Propyltriisopropoxysilane, n-propyltri-t-butoxysilane, n-hexyltrichlorosilane, n-hexyltribromosilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-hexyltriisopropoxysilane , N-hexyltri-t-butoxysilane, n-decyltrichlorosilane, n-decyltribromosilane, n-decyltrimethoxysilane, n-decyltriethoxysilane, n-decyltriisopropoxysilane, n-decyltrit-butoxy Silane, n-octadecyltrichlorosilane, n-octadecyltribromosilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane, n-octadecyltrit-butyl Xysilane, phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxysilane, phenyltri-t-butoxysilane, dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldi Ethoxysilane, diphenyldichlorosilane, diphenyldibromosilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane,

Triethoxyhydrosilane, tribromohydrosilane, trimethoxyhydrosilane, isopropoxyhydrosilane, tri-t-butoxyhydrosilane, vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltrit- Butoxysilane, trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, trifluoropropyltriisopropoxysilane, trifluoropropyltri-t-butoxysilane, γ-glycol Sidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethyl Xysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriisopropoxysilane, γ-glycidoxypropyltri-t-butoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyl Diethoxysila, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropyltrit-butoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane Γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltrit-butoxysilane, γ-mercaptopropylmethyl Methoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-butoxysilane, β- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, and the like.

Along with the silane compound represented by the general formula (II) used for forming the inorganic hydrophilic matrix of the hydrophilic layer of the present invention, it is bonded to a resin during sol-gel conversion of Ti, Zn, Sn, Zr, Al, etc. A metal compound capable of forming a film can be used in combination.
Examples of the metal compound used include Ti (OR ₅ ) ₄ (R ₅ is methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, etc.), TiCl ₄ , Ti (CH ₃ COCHCOCH ₃ ) ₂ ( OR ₅ ) ₂ , Zn (OR ₅ ) ₂ , Zn (CH ₃ COCHCOCH ₃ ) ₂ , Sn (OR ₅ ) ₄ , Sn (CH ₃ COCHCOCH ₃ ) ₄ , Sn (OCOR ₅ ) ₄ , SnCl ₄ , Zr (OR ₅ ) ₄ , Zr (CH ₃ COCHCOCH ₃ ) ₄ , Al (OR ₅ ) ₃ , Al (
CH ₃ COCHCOCH ₃ ) _{3 and the} like.

Furthermore, in order to promote hydrolysis and polycondensation reaction of the silane compound represented by the general formula (II) and the metal compound used in combination, it is preferable to use an acidic catalyst or a basic catalyst in combination.
As the catalyst, an acid or a basic compound is used as it is or in a state in which it is dissolved in a solvent such as water or alcohol (hereinafter referred to as an acidic catalyst and a basic catalyst, respectively). The concentration at that time is not particularly limited, but when the concentration is high, the hydrolysis / polycondensation rate tends to increase. However, when a basic catalyst having a high concentration is used, a precipitate may be generated in the sol solution. Therefore, the degree of the basic catalyst is desirably 1 N (concentration in aqueous solution) or less.

  The type of acidic catalyst or basic catalyst is not particularly limited. Specifically, the acidic catalyst includes hydrogen halides such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid, Basic catalysts such as carboxylic acids such as formic acid and acetic acid, substituted carboxylic acids obtained by substituting R in the structural formula represented by RCOOH with other elements or substituents, and sulfonic acids such as benzenesulfonic acid include ammonia water and the like. Examples thereof include ammoniacal bases and amines such as ethylamine and aniline.

  For more details on the above sol-gel method, see Sakuo Sakuo, “Science of Sol-Gel Method”, Agne Jofusha (published) (1988), Satoshi Hirashima “Functional thin film by the latest sol-gel method. It is described in detail in books such as "Creation Technology" General Technology Center (published) (1992).

  In addition to the above, in the hydrophilic layer of the organic or inorganic hydrophilic matrix of the present invention, control of the degree of hydrophilicity, improvement of the physical strength of the hydrophilic layer, and dispersibility between the compositions constituting the layer It is possible to add compounds for various purposes such as improvement of coating properties, improvement of coating properties, and improvement of printability. For example, plasticizers, pigments, dyes, surfactants, hydrophilic particles and the like can be mentioned.

The hydrophilic particles are not particularly limited, but preferably include silica, alumina, titanium oxide, magnesium oxide, magnesium carbonate, calcium alginate and the like. These can be used for promoting hydrophilicity or strengthening the film. More preferably, it is silica, alumina, titanium oxide or a mixture thereof.
In the hydrophilic layer of the organic or inorganic hydrophilic matrix of the present invention, it is particularly preferable that metal oxide particles such as silica, alumina and titanium oxide are contained.

Silica has many hydroxyl groups on the surface, and the inside constitutes a siloxane bond (—Si—O—Si—).
In the present invention, silica that can be preferably used is ultrafine silica particles having a particle diameter of 1 to 100 nm dispersed in water or a polar solvent, also referred to as colloidal silica. Specifically, it is described in Toshiro Kaga and Hayashi Hayashi, “Applied Technology of High-Purity Silica”, Volume 3, CMC Co., Ltd. (1991).

Alumina that can be preferably used is an alumina hydrate (boehmite) having a colloidal size of 5 to 200 nm, an anion in water (for example, a halogen atom ion such as a fluorine ion or a chlorine ion, an acetate ion). Or the like, as a stabilizer.
Titanium oxide that can be preferably used is an anatase type or rutile type titanium oxide having an average primary particle size of 50 to 500 nm dispersed in water or a polar solvent using a dispersant as required. is there.

In the present invention, the average primary particle size of hydrophilic particles that can be preferably used is 1 to 5.
000 nm, and more preferably 10 to 1000 nm. In the hydrophilic layer of the present invention, these hydrophilic particles may be used alone or in combination of two or more. The amount used is 5% to 90% by weight, preferably 10% to 70% by weight, more preferably 20% to 60% by weight, based on the total solid content weight of the hydrophilic layer.

The hydrophilic layer of the organic or inorganic hydrophilic matrix used in the present invention is supported by dissolving or dispersing in an appropriate solvent such as water, a polar solvent such as methanol or ethanol, or a mixed solvent thereof. It is applied, dried and cured on the body.
The coating weight is 0.1-5 g / m ² , preferably 0.3-3 g / m ² , more preferably 0.5-2 g / m ² after drying. If the coating weight after drying of the hydrophilic layer is too lower than 0.1 g / m ² , it gives an unfavorable result such as a decrease in retention of hydrophilic components such as fountain solution and a decrease in film strength, and is too high. And the film becomes brittle and gives undesirable results such as a decrease in printing durability.

The inorganic thin film having a surface containing a metal oxide used for the hydrophilic layer of the present invention is not particularly limited as long as the surface of the thin film is composed of a hydrophilic metal oxide. A thin film of a metal or a metal compound.
The metal or metal compound that can be used in the hydrophilic layer of the present invention corresponds to d-block (transition) metal, f-block (lanthanoid) metal, aluminum, indium, lead, tin, silicon and alloys, and respective metals. Metal oxides, metal carbides, metal nitrides, metal borides, metal sulfides, metal halides, which are mixed (including uniform mixed films, non-uniform mixed films and laminated films) It can also be used.
In particular, the metal oxide thin film itself is particularly preferable. As the metal oxide thin film, indium oxide, tin oxide, tungsten oxide, manganese oxide, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide and the like and mixed thin films However, it can be suitably used as the hydrophilic layer of the present invention.
The thin film surface of the metal and the metal compound is substantially in a highly oxidized state in the atmosphere, and the surface is composed of a metal oxide and can be used in the present invention. In order to ensure the hydrophilicity of the hydrophilic layer, it is essential that the surface of the inorganic thin film that is the hydrophilic layer is composed of a metal oxide.
For this reason, after forming a thin film, in order to promote the oxidation of the surface, heat treatment, humidification treatment, glow discharge treatment or the like may be performed. Furthermore, a metal oxide may be laminated on the thin film surface.

For the thin film formation of the metal or metal compound used for the hydrophilic layer of the present invention, a PVD method (physical vapor deposition method) such as a vacuum vapor deposition method, a sputtering method, an ion plating method or a CVD method (chemical vapor deposition method) is appropriately used. It is done.
For example, in the vacuum evaporation method, resistance heating, high frequency induction heating, electron beam heating, or the like can be used as the heating method.
Further, as the reactive gas, oxygen or nitrogen may be introduced, or reactive vapor deposition using means such as ozone addition or ion assist may be used.

  In the case of using a sputtering method, a pure metal or a target metal compound can be used as a target material. When pure metal is used, oxygen, nitrogen, or the like is introduced as a reactive gas. As the sputtering power source, a DC power source, a pulse DC power source, or a high frequency power source can be used.

Prior to the formation of the thin film by the above method, in order to improve the adhesion to the lower layer, the substrate may be degassed by heating the substrate or the surface of the lower layer may be subjected to a vacuum glow process.
For example, in the vacuum glow process, a substrate can be processed with the generated plasma by applying a high frequency to the substrate under a pressure of about 1 to 10 mtorr to form a glow discharge.
Further, the effect can be improved by increasing the applied voltage or introducing a reactive gas such as oxygen or nitrogen.

  As for the thickness of the thin film of the metal or metal compound which has a hydrophilic surface used for the hydrophilic layer of this invention, 10 nm-3000 nm are preferable. More preferably, it is 20-1500 nm. If it is too thin, unfavorable results such as a decrease in dampening water retention and a decrease in film strength are given.

  When the hydrophilic layer is provided on the support of the present invention, the surface on the hydrophilic layer side of the support is subjected to sandblasting or the like from the viewpoint of improving the surface area of the hydrophilic layer or improving adhesion with the upper layer. Surface modification treatment such as roughening treatment or corona treatment may be performed.

The original plate for a lithographic printing plate of the present invention is provided with the heat-sensitive layer of the present invention on the hydrophilic surface of a support. If necessary, a water-soluble metal salt such as zinc borate is provided between them. An inorganic undercoat layer or an organic undercoat layer can be provided.
Various organic compounds are used as the organic subbing layer component. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, and optionally substituted phenylphosphones. Organic phosphonic acids such as acids, naphthylphosphonic acids, alkylphosphonic acids, glycerophosphonic acids, methylenediphosphonic acids and ethylenediphosphonic acids, optionally substituted phenylphosphoric acids, naphthylphosphonic acids, alkylphosphoric acids and glycerophosphoric acids Of organic phosphinic acids such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and triethanolamine Hides such as hydrochloride -Alanine, and hydrochlorides of amines having a carboxy group, may be used by mixing two or more.

This undercoat layer can be provided by the following method. That is, a method in which a solution obtained by dissolving the above organic compound in water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is applied to the hydrophilic surface of the support and dried, and water or methanol, The substrate is adsorbed by immersing the support in a solution in which the above organic compound is dissolved in an organic solvent such as ethanol or methyl ethyl ketone or a mixed solvent thereof, and then the organic undercoat layer is formed by washing and drying with water or the like. It is a method of providing.
In the former method, a solution having a concentration of 0.005 to 10% by weight of the organic compound can be applied by various methods.
In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this can be adjusted to a pH range of 1 to 12 with basic substances such as ammonia, triethylamine, potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid. The coating amount of the undercoat layer is suitably ² to 200 mg / m ² , preferably 5 to 100 mg / m ² .
From the viewpoint of preventing blocking, the support used in the present invention preferably has a maximum roughness depth (Rt) of at least 1.2 μm on the back surface of the support, and further, the back surface of the support (that is, The dynamic friction coefficient (μk) when the back surface of the lithographic printing plate precursor) of the present invention slides on the surface of the lithographic printing plate precursor of the present invention is preferably 2.6 or less.

  The thickness of the support used in the present invention is about 0.05 mm to 0.6 mm, preferably 0.1 mm to 0.4 mm, and particularly preferably 0.15 mm to 0.3 mm.

(Thermosensitive layer)
The heat-sensitive layer of the present invention contains microcapsules encapsulating a lipophilic compound, preferably a compound having a heat-reactive functional group.

  Examples of the thermally reactive functional group include an ethylenically unsaturated group that undergoes a polymerization reaction (for example, acryloyl group, methacryloyl group, vinyl group, vinyloxy group, and allyl group), an isocyanate group that undergoes an addition reaction, or a block thereof. , A functional group having an active hydrogen atom that is the reaction partner (for example, an amino group, a hydroxyl group, a carboxyl group, etc.), an epoxy group that also performs an addition reaction, an amino group that is the reaction partner, a carboxyl group or a hydroxyl group, condensation Examples thereof include a carboxyl group and a hydroxyl group or amino group for performing the reaction, and an acid anhydride and amino group or hydroxyl group for performing the ring-opening addition reaction. However, any functional group capable of performing any reaction may be used as long as a chemical bond is formed.

  The microcapsule used in the present invention preferably contains a compound having a thermoreactive functional group. This lipophilic compound has a polymerizable unsaturated group, hydroxyl group, carboxyl group, carboxylate group, acid anhydride group, amino group, epoxy group, isocyanate group, and blocked isocyanate group in the molecule. A compound can be mentioned.

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

Examples include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters thereof, unsaturated carboxylic acid amides, preferably unsaturated carboxylic acids and Examples include esters with aliphatic polyhydric alcohols and amides of unsaturated carboxylic acids with aliphatic polyvalent amines.
Further, 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, a mercapto group and the like with a monofunctional or polyfunctional isocyanate or epoxide, and a monofunctional or A dehydration condensation reaction product with a polyfunctional carboxylic acid is also preferably used.
In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, and further a halogen group or a tosyloxy group A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as monofunctional or polyfunctional alcohol, amine or thiol is also suitable.
Another preferred example is a compound obtained by replacing the unsaturated carboxylic acid with unsaturated phosphonic acid or chloromethylstyrene.

Specific examples of the polymerizable compound that is an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, tetra Methylene 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, sorbitol pentaacrylate, sorbitol hexaacrylate, tris (acryloyl) Oxyethyl) isocyanurate, polyester acrylate oligomer and the like.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 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-hydroxy Propoxy) phenyl] dimethyl methane, bis - [p- (can be given methacryloyloxy ethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.
Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

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

Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.
Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

  In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A urethane compound containing two or more polymerizable unsaturated groups in one molecule obtained by adding an unsaturated monomer having a hydroxyl group represented by the following formula (A) to a polyisocyanate compound having two or more isocyanate groups. Etc.

Formula (A)
CH ₂ ═C (R _m ) COOCH ₂ CH (R _n ) OH (where R _m and R _n represent H or CH ₃ )

  Also, urethane acrylates as described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56-17654 Urethane compounds having an ethylene oxide skeleton described in JP-A No. 62-39417 and JP-B 62-39418 can also be mentioned as preferable examples.

  Further suitable are radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238. Can be mentioned.

  Examples of other suitable ones include polyester acrylates and epoxy resins as described in JP-A-48-64183, JP-B-49-43191, and JP-A-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as epoxy acrylates reacted with (meth) acrylic acid. In addition, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-A-1-40336, vinylphosphonic acid compounds described in JP-A-2-25493, and the like are also included. It can be mentioned as a suitable thing. In some cases, compounds containing a perfluoroalkyl group described in JP-A-61-22048 are also preferably used. Further, those introduced as photocurable monomers and oligomers in Journal of Japan Adhesion Association, Vol. 20, No. 7, pages 300 to 308 (1984) can also be suitably used.

Preferable examples of the copolymer of the ethylenically unsaturated compound include an allyl methacrylate copolymer. For example, allyl methacrylate / methacrylic acid copolymer, allyl methacrylate / ethyl methacrylate copolymer, allyl methacrylate / butyl methacrylate copolymer and the like can be mentioned.
As a suitable compound having a vinyloxy group, a compound containing two or more vinyloxy groups in the molecule is preferable, a reaction between a polyhydric alcohol or polyhydric phenol and acetylene, or a polyhydric alcohol or polyhydric phenol and a halogenated compound. It can be synthesized by reaction with an alkyl vinyl ether.

  Specific examples include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,3-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, trimethylolethane trivinyl ether, hexanediol di Vinyl ether, 1,4-cyclohexanediol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, ethylene glycol diethylene vinyl ether, triethyleneglycol Rudiethylene vinyl ether, ethylene glycol dipropylene vinyl ether, triethylene glycol diethylene vinyl ether, trimethylolpropane triethylene vinyl ether, trimethylolpropane diethylene vinyl ether, pentaerythritol diethylene vinyl ether, pentaerythritol triethylene vinyl ether, pentaerythritol tetraethylene vinyl ether, 1,2- Examples thereof include di (vinyl ether methoxy) benzene and 1,2-di (vinyl ether ethoxy) benzene.

  Suitable epoxy compounds include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene diglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, bisphenols or polyphenols or hydrogenated polyglycidyl ethers. Etc.

  Suitable isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, cyclohexanephenylene diisocyanate, hexamethylene diisocyanate, cyclohexyl diisocyanate, or alcohols or amines thereof. Mention may be made of blocked compounds.

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

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

  As a method for microencapsulation, a known method can be applied. For example, as a method for producing microcapsules, a method using coacervation found in U.S. Pat. Nos. 2,800,547 and 2,800,498, British Patent 990443, U.S. Pat. No. 4, method of interfacial polymerization found in US Pat. No. 42-711, US Pat. No. 3,418,250, method of polymer precipitation shown in US Pat. No. 3,660,304, method of using isocyanate polyol wall material found in US Pat. No. 3,796,669, US Pat. No. 3,914,511 shows a method using an isocyanate wall material, and a urea-formaldehyde-based or urea-formaldehyde-resorcinol-based wall forming material found in US Pat. Nos. 4001140, 4087376, and 4089802. A method using a wall material such as melamine-formaldehyde resin and hydroxycellulose as shown in U.S. Pat. No. 4,025,445, an in situ method by monomer polymerization as shown in JP-B-36-9163 and 51-9079, and British Patent 930422. No. 3, U.S. Pat. No. 3,111,407, spray drying methods, British Patent Nos. 952807, and No. 967074, but are not limited thereto.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with 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 lipophilic compound may be introduced into the microcapsule wall.

The average particle size of the microcapsules is preferably 0.01 to 20 μm, more preferably 0.05 to 2.0 μm, and particularly preferably 0.10 to 1.0 μm. Within this range, good resolution and stability over time can be obtained.
In such a microcapsule, the capsules may be melted by heat and united, or may not be united. In short, among the microcapsule inclusions, the one that oozes out of the capsule surface or outside the microcapsule at the time of application, or the one that enters the microcapsule wall may cause a chemical reaction by heat. You may react with the added hydrophilic resin or the added low molecular weight compound. Alternatively, two or more types of microcapsules may be reacted with each other by providing functional groups that can thermally react with different functional groups.
Therefore, it is preferable for image formation that the microcapsules are fused and merged by heat, but it is not essential.

  The addition amount of the microcapsules to the heat-sensitive layer is preferably 50% by weight or more, more preferably 60 to 95% by weight in terms of solid content. Within this range, good sensitivity and printing durability can be obtained simultaneously with good developability.

When microcapsules are added to the heat-sensitive layer, a solvent that dissolves the inclusions and swells the wall material can be added to the microcapsule dispersion medium. Such a solvent promotes the diffusion of the encapsulated lipophilic compound out of the microcapsule.
Such a solvent depends on the microcapsule dispersion medium, the material of the microcapsule wall, the wall thickness, and the inclusion, 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 preferable.

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

  A solvent that does not dissolve in the microcapsule dispersion but dissolves when the solvent is mixed can also be used. The amount to be added is determined by the combination of materials, but is usually preferably 5 to 95% by weight of the coating solution, more preferably 10 to 90% by weight, and particularly preferably 15 to 85% by weight.

Since the microcapsules encapsulating the lipophilic compound are used in the heat-sensitive layer of the present invention, a compound that initiates or accelerates these reactions may be added as necessary. Examples of the compound that initiates or accelerates the reaction include compounds that generate radicals or cations by heat, such as lophine dimer, trihalomethyl compound, peroxide, azo compound, diazonium salt, or diphenyliodonium salt. And onium salts, acylphosphine, imide sulfonate and the like.
These compounds can be added in the range of 1 to 20% by weight of the heat-sensitive layer solid content. Preferably it is the range of 3 to 10 weight%. Within this range, good reaction initiation or acceleration effect can be obtained without impairing developability.

A hydrophilic resin may be added to the heat-sensitive layer of the present invention. By adding a hydrophilic resin, not only the developability is improved, but also the film strength of the thermosensitive layer itself is improved.
As the hydrophilic resin, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl, carboxymethyl and the like are preferable.

  Specific examples of hydrophilic resins 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 Salts thereof, polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, hydroxybutyl Homopolymers and copolymers of methacrylate, homopolymers and copolymers of hydroxybutyl acrylate Homopolymers of limers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide having a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight And copolymers, methacrylamide homopolymers and polymers, N-methylolacrylamide homopolymers and copolymers, and the like.

  The amount of the hydrophilic resin added to the heat-sensitive layer is preferably 5 to 40% by weight, more preferably 10 to 30% by weight of the heat-sensitive layer solids. Within this range, good developability and film strength can be obtained.

  The lithographic printing plate precursor of the present invention comprises a heat-sensitive layer or a layer adjacent thereto (hydrophilic layer, undercoat layer or overcoat layer described later) containing a photothermal conversion agent, thereby irradiating with a laser beam or the like. Image recording is possible. Moreover, when it contains in a heat sensitive layer, the photothermal conversion agent may be included in the microcapsule, and may be contained outside the microcapsule. As such a photothermal conversion agent, any substance that absorbs the wavelength of the laser light source may be used, and various pigments, dyes, and metal fine particles can be used. In particular, a light absorbing material having an absorption band in at least a part of 700 to 1200 nm is preferable.

  Examples of the pigment include black pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded pigments. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used.

  These pigments may be used without surface treatment, or may be used after surface treatment. Surface treatment methods include surface coating with a hydrophilic resin or lipophilic resin, a method of attaching a surfactant, a reactive substance (eg, silica sol, alumina sol, silane coupling agent, epoxy compound, isocyanate compound, etc.) A method of bonding to the pigment surface is conceivable. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes. Among these pigments, those that absorb infrared rays are preferable because they are suitable for use in lasers that emit infrared rays. Carbon black is preferable as the pigment that absorbs infrared rays. The particle diameter of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm.

Examples of the dye include commercially available dyes and literature (for example, “Dye Handbook” edited by the Society for Synthetic Organic Chemistry, published in 1970, “Chemical Industry”, May 1986, P. 45-51, “Near Infrared Absorbing Dye”, “90 Development and market trends of age functional pigments "Chapter 2. 2.3 (1990) CMC) or known dyes described in patents can be used.
Specifically, infrared absorbing dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, polymethine dyes, and cyanine dyes are preferable.

  Further, for example, cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, JP Methine dyes described in JP-A-58-181690, JP-A-58-194595, etc., JP-A-58-112793, JP-A-58-224793, JP-A-59-48187 Naphthoquinone dyes described in JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., and JP-A-58-112792 Squarylium dye, cyanine dye described in British Patent 434,875, dye described in US Pat. No. 4,756,993, US Pat. No. 4,973,572 And the phthalocyanine compounds described in JP-A-11-235883.

Further, near-infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used as dyes, and substituted arylbenzo (thio) pyrylium described in US Pat. No. 3,881,924. Salt, trimethine thiapyrylium salt described in JP-A No. 57-142645, JP-A Nos. 58-181051, 58-220143, 59-41363, 59-84248, 59 -84249, 59-146063, 59-146061, pyrylium compounds, cyanine dyes described in JP-A-59-216146, U.S. Pat. No. 4,283,475 The pentamethine thiopyrylium salt described in Japanese Patent Publication No. 5-13514 and No. 5-19702 , Eporin Co. Epolight III-178, Epolight III-130, Epolight III-125 and the like is also preferably used.
Among these dyes, some specific examples of water-soluble cyanine dyes that can be suitably used are shown below.

  The organic photothermal conversion agent can be added up to 30% by weight in the heat sensitive layer. Preferably it is 5-25 weight%, Most preferably, it is 7-20 weight%. Within this range, good sensitivity can be obtained.

In the heat-sensitive layer of the present invention, metal fine particles can also be used as a photothermal conversion agent. Most of the metal fine particles are photothermal convertible and self-heating, but preferable metal fine particles include Si, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr. , Mo, Ag, Au, Pt, Pd, Rh, In, Sn, W, Te, Pb, Ge, Re, and Sb, or oxide or sulfide fine particles thereof.
Among the metals constituting these metal fine particles, preferred metals are those that are likely to coalesce by heat when irradiated with light, have a melting point of about 1000 ° C. or less, and have absorption in the infrared, visible, or ultraviolet region, such as Re, Sb, Te, Au, Ag, Cu, Ge, Pb and Sn.
Particularly preferred are metal fine particles such as Ag, Au, Cu, Sb, Ge and Pb, which have a relatively low melting point and a relatively high absorbance to infrared rays, and the most preferred elements are Ag, Au and Cu. Is mentioned.

Also, for example, fine particles of low melting point metal such as Re, Sb, Te, Au, Ag, Cu, Ge, Pb, Sn, and fine particles of self-heating metal such as Ti, Cr, Fe, Co, Ni, W, Ge Or a mixture of two or more photothermal conversion substances. Ag,
It is also preferable to use a combination of a small metal piece having a particularly large light absorption when combined with another fine metal piece such as Pt and Pd.

  The particle diameter of these particles is preferably 10 μm or less, more preferably 0.003 to 5 μm, and particularly preferably 0.01 to 3 μm. Within this range, good sensitivity and resolution can be obtained.

  In the present invention, when these metal fine particles are used as a photothermal conversion agent, the amount added is preferably 10% by weight or more, more preferably 20% by weight or more, particularly preferably 30% by weight or more, based on the solid content of the heat sensitive layer. Used in High sensitivity is obtained within this range.

  The thermosensitive layer of the lithographic printing plate precursor according to the present invention may further contain a low molecular compound having a functional group capable of reacting with the lipophilic compound contained in the microcapsule and a protective group thereof. The amount of these compounds added is preferably 5% by weight to 40% by weight in the heat sensitive layer, and particularly preferably 5% by weight to 20% by weight. If the amount is less than this, the crosslinking effect is small and the printing durability is lowered. Specific examples of such compounds include the same examples as the specific examples of lipophilic compounds encapsulated in the microcapsules.

In addition to the above, various compounds may be added to the heat-sensitive layer of the present invention as necessary. For example, a dye having a large absorption in the visible light region can be used as an image colorant in order to make it easy to distinguish between an image area and a non-image area after image formation. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in No. 293247. Further, pigments such as phthalocyanine pigments, azo pigments, and titanium oxide can also be suitably used. The addition amount is preferably 0.01 to 10% by weight based on the total solid content of the heat-sensitive layer coating solution.
Furthermore, it is preferable to add a coloring or decoloring compound in the heat-sensitive layer of the present invention in order to sharpen the image area and the non-image area when exposed. For example, a leuco dye (leucomalachite green, leuco crystal violet, crystal violet lactone, etc.) and a pH-changing dye (eg ethyl violet, Victoria Poor Blue BOH, etc.) together with a thermal acid generator such as a diazo compound or diphenyliodonium salt Dyes). These dyes may be included in the microcapsule or may be contained outside the microcapsule.

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

If necessary, higher fatty acids such as behenic acid and behenic acid amide or derivatives thereof are added to prevent polymerization inhibition by oxygen, and are unevenly distributed on the surface of the heat-sensitive layer in the drying process after coating. Also good. The amount of the higher fatty acid or derivative thereof added is preferably about 0.1 to about 10% by weight based on the solid content of the heat sensitive layer.

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

  The heat-sensitive layer of the present invention is applied by preparing a coating solution by dispersing or dissolving the necessary components described above in a solvent. Solvents used here include 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, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by weight.

Moreover, although the heat sensitive layer coating amount (solid content) on the support obtained after application | coating and drying changes with uses, generally 0.4-5.0 g / m < ² > is preferable. When the coating amount is less than this range, the apparent sensitivity increases, but the film properties of the heat-sensitive layer that performs the function of image recording deteriorate. Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

  A surfactant for improving the coating property, for example, a fluorine-based surfactant described in JP-A-62-170950 can be added to the heat-sensitive layer coating solution. A preferable addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the total solid content of the heat-sensitive layer.

(Overcoat layer)
In the lithographic printing plate precursor according to the present invention, an overcoat layer can be provided on the heat-sensitive layer in order to prevent contamination and scratches by the lipophilic substance on the surface of the heat-sensitive layer. The overcoat layer used in the present invention can be easily removed with a hydrophilic printing liquid such as dampening water during printing, and contains a resin selected from hydrophilic organic polymer compounds. As the hydrophilic organic polymer compound used here, a film formed by drying has a film-forming ability. Specifically, polyvinyl acetate (however, a hydrolysis rate of 65% or more), polyacrylamine salt , Polyacrylic acid copolymer, alkali metal salt or amine salt thereof, polymethacrylic acid, alkali metal salt or amine salt thereof, polymethacrylic acid copolymer, alkali metal salt or amine salt thereof, polyacrylamide, copolymer thereof , Polyhydroxyethyl acrylate, polyvinyl pyrrolidone, copolymer thereof, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, alkali metal salt thereof, or Amine salt, poly-2-acrylamide-2-methyl -1-Propanesulfonic acid copolymer, alkali metal salt or amine salt thereof, gum arabic, fiber derivative (for example, carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose, etc.), modified product thereof, white dextrin, pullulan, enzyme Decomposed etherified dextrin and the like can be mentioned. Further, two or more kinds of these resins can be mixed and used depending on the purpose.

In addition, the hydrophilic photothermal conversion agent may be added to the overcoat layer. Furthermore, in order to ensure the uniformity of coating, a nonionic surfactant such as polyoxyethylene nonylphenyl ether or polyoxyethylene dodecyl ether can be added to the overcoat layer in the case of aqueous solution coating. . The dry coating amount of the overcoat layer is preferably 0.1 to 2.0 g / m ² . Within this range, developability is not impaired, and the surface of the heat-sensitive layer can be satisfactorily prevented from being contaminated or scratched by an oleophilic substance such as a fingerprint adhering stain.

(Image formation and plate making)
The lithographic printing plate precursor of the present invention is image-formed by heat. Specifically, direct image-like recording by a thermal recording head or the like, scanning exposure by an infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, infrared lamp exposure, or the like is used, but a semiconductor that emits infrared light having a wavelength of 700 to 1200 nm. Exposure with a solid high-power infrared laser such as a laser or YAG laser is preferred.

The lithographic printing plate precursor of the present invention on which the image has been recorded is then removed in the presence of the treatment liquid by rubbing the plate surface with a rubbing member to remove the heat-sensitive layer in the non-image area (if there is an overcoat layer, The overcoat layer is also removed at the same time.) In the non-image area, the surface of the hydrophilic support is exposed to produce a lithographic printing plate.
Examples of the rubbing member usable in the present invention include non-woven fabric, cotton cloth, cotton pad, molton, rubber blade, brush and the like.

As the treatment liquid used in the present invention, a hydrophilic treatment liquid is suitable. For example, water alone or an aqueous solution containing water as a main component is preferable, and in particular, the composition is the same as that of generally known dampening water. An aqueous solution containing an aqueous solution or a surfactant (anionic, nonionic, cationic, etc.) is preferred.
Further, the treatment liquid of the present invention may contain an organic solvent. Examples of the solvent that can be contained include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (Esso Chemical Co., Ltd.) or gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, Xylene, etc.), halogenated hydrocarbons (trichlene, etc.), and the following polar solvents.

  Examples of polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, propylene glycol mono Ethyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polypropylene glycol, tetraethylene glycol, etc.), ketones (acetone, methyl ethyl ketone, etc.), esters (ethyl acetate, methyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, Diethylene glycol acetate, diethyl alcohol Rate, etc.), others (triethyl phosphate, tricresyl phosphate and the like).

If the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. If the treatment liquid contains a solvent, it is safe and flammable. In view of the above, the concentration of the solvent is preferably less than 40% by weight.
As the surfactant used in the treatment liquid of the present invention, a nonionic surfactant can be suitably used from the viewpoint of foam suppression.
Nonionic surfactants that can be used in the treatment liquid of the present invention include polyethylene glycol type higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher Alkylamine ethylene oxide adduct, fatty acid amide ethylene oxide adduct, oil and fat ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymer, etc. , Fatty acid ester of glycerol of polyhydric alcohol type, fatty acid ester of pentaerythritol, sorbitol and Fatty acid esters of Rubitan, fatty acid ester of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines. These nonionic surfactants may be used alone or in admixture of two or more. In the present invention, ethylene oxide adduct of sorbitol and / or sorbitan fatty acid ester, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymer, polyhydric alcohol Fatty acid esters are more preferred.

In addition, from the viewpoint of stable solubility or turbidity in water, the nonionic surfactant used in the treatment liquid of the present invention is HLB (Hydrophile-Lipophile).
The (Balance) value is preferably 6 or more, and more preferably 8 or more.
Furthermore, the ratio of the nonionic surfactant contained in the treatment liquid is preferably 0.01 to 10% by weight, and more preferably 0.01 to 5% by weight. In addition, an alkaline agent (for example, sodium carbonate, triethanolamine, diethanolamine, sodium hydroxide, silicates, etc.) or an acidic agent (for example, phosphoric acid, phosphorous acid, metaphosphoric acid, pyrophosphoric acid, oxalic acid) , Malic acid, tartaric acid, boric acid, amino acids, etc.), preservatives (for example, benzoic acid and its derivatives, sodium dehydroacetate, 3-isothiazolone compounds, 2-bromo-2-nitro-1, 3-propanediol, 2 -Pyridinethiol-1-oxide sodium salt and the like) can also be used.
Although the temperature of a process liquid can be used at arbitrary temperature, Preferably it is 10 to 50 degreeC.

  The removal of the heat-sensitive layer in the non-image area in the present invention can be preferably carried out by an automatic processor equipped with a processing liquid supply means and a rubbing member. As an automatic processor, for example, an automatic processor described in JP-A-2-220061, JP-A-60-59351, which performs rubbing while conveying an original plate for lithographic printing plate after image recording, Examples thereof include an automatic processor described in US Pat. No. 5,148,746, US Pat. No. 5,568,768 and GB 2277719, which rubs the lithographic printing plate precursor after image recording set on the cylinder while rotating the cylinder. Among these, an automatic processor using a rotating brush roll as the rubbing member is particularly preferable. As an example of an automatic processor suitable for the development processing of the present invention shown in FIG. 1, a processing liquid 10 is sent to a spray pipe 5 by a circulation pump 11 and showered, and a rotating brush roll 1 and a plate surface 12 (for lithographic printing plates) are used. An example of an automatic developing processing machine that is supplied to the original plate and rubs the plate surface 12 with the rotating brush roll 1 is illustrated. In the present invention, the lithographic printing plate after the rubbing treatment can be optionally washed with water and dried.

The rotating brush roll that can be used can be selected as appropriate in consideration of the difficulty of scratching the image area and the stiffness of the support of the lithographic printing plate precursor.
As the rotating brush roll, a known one formed by planting a brush material on a plastic or metal roll can be used. For example, a metal or plastic in which brush materials are implanted in rows, as described in Japanese Patent Application Laid-Open No. 58-159533, Japanese Patent Application Laid-Open No. 3-100534, or Japanese Utility Model Publication No. 62-167253. A brush roll in which the groove mold material is radially wound around a plastic or metal roll as a core without any gap can be used. The brush material includes plastic fibers (for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 6.6, nylon 6.1).
Polyamides such as polyamides such as 0, polyacrylics such as polyacrylonitrile and poly (meth) acrylates, and polyolefins such as polypropylene and polystyrene), for example, the fiber diameter is The thing of 20-400 micrometers and the length of the hair 5-30 mm can be used conveniently. Furthermore, the outer diameter of the rotating brush roll is preferably 30 to 200 mm, and the peripheral speed at the tip of the brush rubbing the plate surface is preferably 0.1 to 5 m / sec.

  The rotating direction of the rotating brush roll used in the present invention may be the same or opposite to the conveying direction of the planographic printing plate precursor of the present invention, but the automatic processor illustrated in FIG. As described above, when two or more rotating brush rolls are used, it is preferable that at least one rotating brush roll rotates in the same direction and at least one rotating brush roll rotates in the opposite direction. This further ensures the removal of the heat sensitive layer in the non-image area. Furthermore, it is also effective to swing the rotating brush roll in the direction of the rotation axis of the brush roll.

  The present invention will be described more specifically with reference to the following examples, but the scope of the present invention is of course not limited thereto.

[Example 1]
(Creation of aluminum support)
JIS A1050 aluminum material (heat conductivity of 0.1% by weight) containing 99.5% by weight aluminum, 0.01% by weight copper, 0.03% by weight titanium, 0.3% by weight iron and 0.1% by weight silicon. 48 cal / cm · sec · ° C.) using a 0.24 mm-thick rolled plate, a 400-mesh Pamiston (made by Kyoritsu Ceramics) 20 wt% aqueous suspension and a rotating nylon brush (6,10-nylon) The surface was grained and washed thoroughly with water. This was immersed in a 15% by weight aqueous sodium hydroxide solution (containing 4.5% by weight of aluminum), etched so that the amount of aluminum dissolved was 5 g / m ² , and then washed with running water. Further, neutralize with 1 wt% nitric acid, and then in a 0.7 wt% nitric acid aqueous solution (containing 0.5 wt% aluminum), a rectangular wave with an anode voltage of 10.5 volts and a cathode voltage of 9.3 volts Using an alternating waveform voltage (current ratio r = 0.90, current waveform described in the example of JP-B-58-5796), electrolytic surface roughening treatment was performed at an anode time electricity of 160 clones / dm ^2. It was. After washing with water, it was immersed in a 10 wt% sodium hydroxide aqueous solution at 35 ° C., etched so that the amount of dissolved aluminum was 1 g / m ² , and then washed with water. Next, it was immersed in an aqueous sulfuric acid solution at 50 ° C. and 30% by weight, desmutted, and then washed with water. Further, a porous anodic oxide film formation treatment was performed using a direct current in a 20 wt% sulfuric acid aqueous solution (containing 0.8 wt% aluminum) at 35 ° C. That is, electrolysis was performed at a current density of 13 A / dm ² and the weight of the anodic oxide film was adjusted to 2.7 g / m ² by adjusting the electrolysis time.
The support was washed with water, immersed in a 0.2 wt% aqueous solution of sodium silicate at 70 ° C. for 30 seconds, washed with water and dried.

(Synthesis of microcapsule 1 encapsulating a lipophilic compound)
Takenate D-110N (manufactured by Takeda Pharmaceutical Co., Ltd., trifunctional isocyanate) 30 g, Karenz MOI (Showa Denko, 2-methacryloyloxyethyl isocyanate) 10 g, trimethylolpropane triacrylate 10 g, allyl methacrylate and butyl methacrylate as oil phase components 10 g of a polymer (molar ratio 60/40) and 0.1 g of pionine A41C (manufactured by Takemoto Yushi) were dissolved in 60 g of ethyl acetate. As an aqueous phase component, 120 g of a 4% aqueous solution of PVA205 (manufactured by Kuraray) was prepared. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm using a homogenizer. Thereafter, 40 g of water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The microcapsule solution thus obtained had a solid content concentration of 20% and an average particle size of 0.5 μm.

(Formation of heat-sensitive layer)
A coating liquid having the following composition was coated on the support and dried (90 ° C., 2 minutes) to form a heat-sensitive layer having a dry coating weight of 1 g / m ² to obtain a lithographic printing plate precursor.

(Thermosensitive layer coating solution 1)
25 g of the dispersion of the above synthesized microcapsule 1
Polyacrylic acid 0.5g
(Weight average molecular weight 25000)
Sorbitol triacrylate 1.0g
Photothermal conversion agent A (below) 0.3g
0.3 g of t-butyldiphenyliodonium sulfate
70g of water
30 g of 1-methoxy-2-propanol

(Preparation of lithographic printing plate)
The lithographic printing plate precursor thus obtained was exposed under conditions of a plate surface energy of 200 mJ / cm ² and a resolution of 2400 dpi using a Trendsetter 3244VFS manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser, and the same as in FIG. Development processing was performed using an automatic processor having two rotating brush rolls of the above mechanism. As the rotating brush roll, a brush roll having an outer diameter of 90 mm in which fibers made of polybutylene terephthalate (hair diameter: 200 μm, hair length: 17 mm) is used for the first brush roll, and the same direction as the conveying direction is used. Min. 200 revolutions (peripheral speed 0.94 m / sec at the tip of the brush), and the second brush roll was implanted with fibers made of polybutylene terephthalate (hair diameter 200 μm, hair length 17 mm) 60 mm outer diameter The brush roll was rotated 200 times per minute in the direction opposite to the conveying direction (peripheral speed of the brush tip: 0.63 m / sec). The planographic printing plate precursor was transported at a transport speed of 100 cm / min.
The treatment liquid used was the following treatment liquid 1, showered from a spray pipe with a circulation pump, and supplied to the plate surface.

(Processing liquid 1)
RHEODOL TW-O106 0.5g
(Manufactured by Kao Corporation, polyoxyethylene sorbitan monooleate,
HLB = 10.0)
EU-3 (Etch solution manufactured by Fuji Photo Film Co., Ltd.) 2.0 g
97.5g of water

(Print evaluation)
Subsequently, the obtained lithographic printing plate was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg, and printing was performed (fountain solution used: IF-102 (Fuji Photo Film Co., Ltd.) was added at 4% by volume. Water, used ink: TK Hi-Echo SOYMZ ink (manufactured by Toyo Ink Co., Ltd.) and evaluated the number of non-image area inks to be printed at the time of printing. The smudges on the areas disappeared, and a printed matter with good ink fillability on the image areas was obtained.

[Comparative Example 1]
The lithographic printing plate precursor of Example 1 was subjected to development processing in the same manner as in Example 1 except that the rotating brush roll of the automatic processor in Example 1 was removed after image exposure in the same manner as in Example 1. That is, only the treatment liquid cleaning was performed without rubbing with a rubbing member. Thereafter, the obtained lithographic printing plate was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg, and printing was carried out in the same manner as in Example 1 to evaluate the number of non-image area inks to be removed during printing. 50 sheets were required until the non-image area was clean.

[Comparative Example 2]
The lithographic printing plate precursor of Example 1 was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg without any treatment after image exposure in the same manner as in Example 1, and printing was performed in the same manner as in Example 1. As a result of evaluating the number of non-image area inks to be removed at the time of printing, 50 sheets were required until the non-image area was free of contamination.

[Example 2]

(Synthesis of microcapsule 2 encapsulating a lipophilic compound)
As oil phase components, Takenate D-110N (manufactured by Takeda Pharmaceutical Co., Ltd., trifunctional isocyanate) 40 g, diethylene glycol diglycidyl ether 20 g, and Pionein A41C (manufactured by Takemoto Yushi) were dissolved in 60 g of ethyl acetate. As an aqueous phase component, 120 g of a 4% aqueous solution of PVA205 (manufactured by Kuraray) was prepared. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm using a homogenizer. Thereafter, 40 g of water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The microcapsule liquid thus obtained had a solid content concentration of 20% and an average particle size of 0.6 μm.

(Formation of heat-sensitive layer)
A lithographic printing plate precursor was obtained by forming a heat sensitive layer in the same manner as in Example 1 except that the heat sensitive layer coating solution of Example 1 was changed to a coating solution having the following composition.

(Thermosensitive layer coating solution 2)
25 g of the dispersion of the above synthesized microcapsule 2
Polyacrylic acid 0.5g
(Weight average molecular weight 25000)
Diethylenetriamine 1.0g
Photothermal conversion agent A 0.3g
0.3 g of t-butyldiphenyliodonium sulfate
70g of water
30 g of 1-methoxy-2-propanol

  Subsequently, the obtained lithographic printing plate precursor was subjected to image exposure, development processing and printing in the same manner as in Example 1 and evaluated for the number of non-image area inks to be printed at the time of printing. Within the eyes, the non-image area was free from smudges, and a printed matter with good ink fillability in the image area was obtained.

Example 3
(Synthesis of microcapsule 3 encapsulating lipophilic compound)
As oil phase components, Takenate D-110N (Takeda Pharmaceutical Co., Ltd., trifunctional isocyanate) 40 g, Bisphenol A bis (vinyloxyethyl) ether 15 g, Photothermal conversion agent B (below) 5 g, Pionine A41C (Takemoto Yushi) 0. 1 g was dissolved in 60 g of ethyl acetate. 120 g of a 4% aqueous solution of PVA205 (manufactured by Kuraray) in which 1 g of tetraethylenepentamine was dissolved as an aqueous phase component was prepared. The oil phase component and the aqueous phase component were emulsified at 10,000 rpm using a homogenizer. Thereafter, 40 g of water was added, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours. The microcapsule liquid thus obtained had a solid content concentration of 20% and an average particle size of 0.4 μm.

(Formation of heat-sensitive layer)
A lithographic printing plate precursor was obtained by forming a heat sensitive layer in the same manner as in Example 1 except that the heat sensitive layer coating solution of Example 1 was changed to a coating solution having the following composition.

(Thermosensitive layer coating solution 3)
25 g of the dispersion of the above synthesized microcapsule 3
Diphenyliodonium trifluoromethylsulfonate 0.5g
Megafuck F-171 0.05g
(Dainippon Ink Industries, Fluorosurfactant)
100g of water

  Subsequently, the obtained lithographic printing plate precursor was subjected to image exposure, development processing and printing in the same manner as in Example 1 and evaluated for the number of non-image area inks to be printed at the time of printing. Within the eyes, the non-image area was free from smudges, and a printed matter with good ink fillability in the image area was obtained.

Example 4
A lithographic printing plate precursor was obtained in the same manner as in Example 1 except that the following overcoat layer was formed on the heat-sensitive layer.

(Formation of overcoat layer)
On the heat-sensitive layer, the following overcoat layer coating solution was applied and dried by heating (100 ° C., 2 minutes) to form an overcoat layer having a dry coating weight of 0.3 g / m ² .

(Overcoat layer coating solution)
・ 1g gum arabic
・ Emalex 710 0.025g
(Nippon Emulsion Co., Ltd., polyoxyethylene lauryl ether)
・ Water 19g

  Next, in the same manner as in Example 1, image exposure, development processing, and printing were carried out, and the number of non-image area inks to be removed at the time of printing was evaluated. As a result, there was no smudge, and a printed matter with good ink fillability in the image area was obtained.

FIG. 2 is a layout view showing a configuration of an automatic developing processor suitable for a method for producing a lithographic printing plate according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating brush roll 2 Receiving roll 3 Conveying roll 4 Conveying guide plate 5 Spray pipe 6 Pipe line 7 Filter 8 Plate feed table 9 Discharge plate 10 Processing liquid (tank)
11 Circulating pump 12 Planographic printing plate

Claims (1)

  Image recording was performed on a lithographic printing plate precursor provided with a thermosensitive layer containing microcapsules encapsulating a lipophilic compound on a support having a hydrophilic surface, and then the plate surface was rubbed with a rubbing member in the presence of a treatment liquid. A method for preparing a lithographic printing plate, comprising the step of removing the heat-sensitive layer in the non-image area by rubbing the surface.

Images