JP2006051736A - Original plate for lithography and lithographic printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate for lithography which enables printing without development after exposure and has extremely high sensitivity (efficiency of photothermal conversion). <P>SOLUTION: The original plate for lithography has a hydrophilic layer containing particles and a substrate, and the particle has a shell constituted of a polymer and a core constituted of a hydrophobic compound. The shell contains a photothermal conversion agent in a range of 0.9-3 pts.mass in relation to 1 pt.mass of the polymer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lithographic printing plate precursor having a hydrophilic layer containing particles and a support, wherein the particles have a shell part made of a polymer and a core part made of a hydrophobic compound. In particular, the present invention relates to a negative lithographic printing original plate that does not require development. The present invention also relates to a lithographic printing original plate capable of infrared scanning exposure based on a digital signal. Furthermore, the present invention relates to a lithographic printing method in which an image is recorded on a lithographic printing original plate and printed as it is without being subjected to development processing.

  Computer-to-plate printing plates have made significant progress in recent years, and many studies have been made. The main research subjects are rationalization of the treatment process and solution of the waste liquid treatment problem. In order to solve these problems, lithographic printing original plates that can be mounted and printed on a printing machine without performing post-exposure development processing, and lithographic printing original plates that can be exposed on a printing machine and printed as they are, have been studied. Various methods have been proposed.

  A thermosensitive lithographic printing original plate having a hydrophilic image forming layer in which thermoplastic polymer fine particles are dispersed in a matrix such as a hydrophilic resin on a substrate having a hydrophilic surface is disclosed (for example, Patent Documents 1 to 3). 3). When heat is applied to these image forming layers by infrared exposure or the like, the thermoplastic polymer fine particles melt and coalesce, and the surface of the hydrophilic image forming layer is converted into an oleophilic image portion. A method that removes the unheated part as if it had been developed by mounting the plate on the printing press and supplying dampening water and ink to the printing plate while rotating the plate cylinder (on-press development method) Therefore, it is possible to omit the conventional development processing using an automatic developing machine or the like.

  Further, it has been proposed to develop on-machine a lithographic printing material containing a microgel having a functional group that decomposes on the surface by light and / or heat energy and an infrared light absorber in the image forming layer (for example, Patent Document 4).

  However, in the above-mentioned on-press development type unprocessed lithographic printing plate, removal of unexposed portions depends on the operation start conditions of the printing press, or a removal product containing a large amount of lipophilic component is dampened with a dampening water roller or dampening. Since the water is contaminated, there are problems that cost and labor are required such that several tens to several hundreds of prints are required and a roller needs to be washed to obtain a good print.

  A heat-sensitive lithographic printing original plate having a heat-sensitive layer dispersed in a hydrophilic resin in which thermoplastic polymer fine particles are crosslinked has been proposed (see, for example, Non-Patent Document 1). In addition, a heat-sensitive lithographic printing original plate having a hydrophilic layer in which microcapsules encapsulating lipophilic components as lipophilic fine particles in a cross-linked hydrophilic binder polymer is also proposed (see, for example, Patent Documents 5 to 8). ). These heat-sensitive lithographic printing original plates do not require on-machine development by using the surface structure of the oleophilic image area formed by heat from exposure and the hydrophilic non-image area of the unexposed area as the printing surface. Lithographic printing using fountain solution can be performed without any treatment.

  However, in the heat-sensitive lithographic printing original plate having a heat-sensitive layer in which the above-mentioned thermoplastic polymer fine particles are dispersed in a crosslinked hydrophilic resin, the thermoplastic polymer fine particles are thermoplasticized or thermally melted to make the surroundings hydrophobic. Therefore, it is necessary to give high thermal energy to the sensitive material layer. In addition, in a heat-sensitive lithographic printing original plate having a hydrophilic layer in which microcapsules encapsulating lipophilic components are dispersed, it is possible in principle to proceed with hydrophobicity even with low exposure energy. However, depending on the storage conditions, the lipophilic component diffuses from the microcapsule into the hydrophilic layer and causes non-image area contamination, so the microcapsule must have a certain degree of partitioning. Since this partition wall property and the thermal response of the microcapsule fall into a trade-off, it is very difficult to achieve both sensitivity and non-image area contamination.

In order to improve sensitivity, a lithographic printing plate precursor having an image forming layer containing microcapsules and a hydrophilic support, the microcapsules having a shell made of a polymer and a core made of a polymerizable compound, There has been proposed a lithographic printing original plate in which a photothermal conversion agent is dispersed in (see, for example, Patent Document 9). In a lithographic printing original plate using microcapsules, the shell of the microcapsule in the heated area is thermally decomposed, and the polymerizable compound in the heated area is polymerized to form an image. Since the decomposition temperature of the shell polymer is higher than the polymerization temperature of the polymerizable compound, the decomposition of the shell polymer is an important factor governing image formation. Therefore, when the photothermal conversion agent is added to the shell rather than to the core of the microcapsule, heat can be efficiently generated at a place where the heat is more required (shell). If a photothermal conversion agent is added to the shell, the thermal decomposition of the shell polymer is promoted, and the sensitivity of the lithographic printing plate precursor is improved.
As a specific means for dispersing the photothermal conversion agent in the polymer, a method of chemically bonding the polymer and the photothermal conversion agent is disclosed. Further, as the lithographic printing method, an on-press development method in which development is performed with dampening water, oil-based ink, or rubbing on a printing press is disclosed.

Japanese Patent No. 2938297 JP-A-9-127683 WO99 / 10186 pamphlet JP 2000-238452 A JP-A-7-1849 JP-A-7-1850 Japanese Patent Laid-Open No. 10-6468 Japanese Patent Laid-Open No. 11-70756 JP 2004-90437 A Research Disclosure, January 1992, No. 33303

As disclosed in JP-A-2004-90437, when a photothermal conversion agent is added to the shell of the microcapsule, the thermal decomposition of the shell polymer is promoted, and the sensitivity of the lithographic printing plate precursor is improved. By this improvement, sufficient sensitivity can be obtained as a lithographic printing plate used in the on-press development method.
The inventor has tried to apply the above-described improvement to a lithographic printing original plate not subjected to development processing (no processing). As a result, it was found that although the effect of improving the sensitivity was observed, the sensitivity was lower than that of the on-press development printing plate subjected to the same improvement, and the sensitivity was insufficient for the use of the unprocessed lithographic printing plate.

  An object of the present invention is to provide a lithographic printing plate precursor that can be printed without being subjected to a development process after exposure and has a very high sensitivity (photothermal conversion efficiency).

The present invention provides the following lithographic printing plate precursors (1) to (6).
(1) A lithographic printing original plate having a hydrophilic layer containing particles and a support, wherein the particles have a shell part made of a polymer and a core part made of a hydrophobic compound, wherein the shell part is further a photothermal conversion agent Is contained in a range of 0.9 to 3 parts by mass with respect to 1 part by mass of the polymer.
(2) The particles include a hydrophobic compound and a photothermal conversion agent, the I / O value difference between the hydrophobic compound and the photothermal conversion agent is 0.2 or more, and the I / O value of the hydrophobic compound is The lithographic printing plate precursor as described in (1), which is lower than the I / O value of the photothermal conversion agent.
(3) The lithographic printing original plate as described in (1), wherein the particles are microcapsules.
(4) The lithographic printing plate precursor as described in (1), wherein the hydrophilic layer further contains a water-insoluble hydrophilic resin outside the particles.
(5) The lithographic printing plate precursor as described in (1), wherein the hydrophobic compound has a polymerizable group, and the hydrophilic layer further contains a polymerization initiator (inside or inside the particle).
(6) The lithographic printing original plate as described in (1), wherein the photothermal conversion agent is an infrared absorber.

Furthermore, the present invention provides the following lithographic printing methods (7) and (8).
(7) It has a hydrophilic layer containing particles and a support, and the particles have a shell part made of a polymer and a core part made of a hydrophobic compound, and the shell part further converts the photothermal conversion agent into 1 part by weight of the polymer. In contrast, a lithographic printing plate precursor containing 0.9 to 3 parts by mass is exposed to an image, and the exposed hydrophilic layer surface is converted to hydrophobic, and an unexposed hydrophilic layer. A lithographic printing method comprising: a step of making a lithographic printing plate having a hydrophilic region comprising a surface; and a step of printing with the lithographic printing plate made from the plate.
(8) The lithographic printing method according to (7), wherein the photothermal conversion agent is an infrared absorber, and the lithographic printing original plate is exposed in an image form by scanning exposure with an infrared laser.

As described above, as a result of the inventor's research, in the method of making a lithographic printing plate without carrying out development processing including on-press development (without processing), a method of making a lithographic printing plate by development processing, In comparison, it has been found that it is difficult to obtain the sensitivity required for a lithographic printing original plate.
In the method of making a lithographic printing plate by development processing including on-machine development, a hydrophilic region and a hydrophobic region are formed by removing unexposed portions (or exposed portions). Accordingly, the thermal energy generated by the photothermal conversion only needs to have an amount sufficient to cause a change that is relatively difficult to remove (or relatively easily removed) compared to the unexposed portion. That is, the hydrophilic region and the hydrophobic region of the lithographic printing plate are formed not by exposure processing but by development processing.
On the other hand, in a method of making a lithographic printing plate without performing development processing (without processing), a hydrophilic region is converted into a hydrophobic region only by exposure processing, that is, only energy generated by photothermal conversion. Therefore, the amount of heat energy generated by the photothermal conversion action in the lithographic printing plate is more important than in the method of making a lithographic printing plate by development processing.

As disclosed in JP-A-2004-90437, when a photothermal conversion agent is added to the shell of a microcapsule, a highly sensitive lithographic printing original plate can be obtained. However, the planographic printing original plate described in the publication is designed mainly assuming a method of developing on a printing press (on-press development method). Therefore, in order to use it in a method for making a lithographic printing plate without carrying out development processing (without processing), it is necessary to further improve the amount of heat energy generated by the photothermal conversion action.
As a result of further research by the present inventor, the lithographic printing plate disclosed in Japanese Patent Application Laid-Open No. 2004-90437 has a small amount of photothermal conversion agent added to the shell of the microcapsule, and without performing the development processing. It was found that the sensitivity was insufficient to make a lithographic printing plate (without treatment).

Japanese Unexamined Patent Application Publication No. 2004-90437 discloses a method of chemically bonding a polymer and a photothermal conversion agent as a specific means for dispersing the photothermal conversion agent in a shell polymer. According to the publication, when the shell polymer of the microcapsule is synthesized from an isocyanate, the mass ratio of the photothermal conversion agent / isocyanate in the synthesis reaction is preferably 1/100 to 80/100, and 5/100 to 50 / It is described that 100 is more preferable (paragraph number 0062 of JP-A-2004-90437). That is, it is preferable that the photothermal conversion agent is contained in the range of 0.01 to 0.8 parts by mass, and more preferably 0.05 to 0.5 parts by mass with respect to 1 part by mass of the polymer. Explains.
The inventors' research has revealed that a large amount of photothermal conversion agent can be added to the shell portion of the particles. Specifically, the photothermal conversion agent can be added in the range of 0.9 to 3 parts by mass with respect to 1 part by mass of the polymer. By adding a large amount of a photothermal conversion agent to the shell part of the particles, an extremely sensitive lithographic printing original plate can be obtained. Therefore, the lithographic printing original plate according to the present invention has very high sensitivity (photothermal conversion efficiency), and can be used particularly advantageously in a method of printing without performing development processing after exposure.

[Particles having a shell portion made of a polymer and a core portion made of a hydrophobic compound]
The particles consist of a shell part and a core part. The shell part is a partial structure having a part exposed on the particle surface, and the core part is a partial structure existing only inside the particle (no part exposed on the particle surface). The particles may have a plurality of shell portions or a plurality of core portions.
The shell part is made of a polymer, and the core part is made of a hydrophobic compound. The particles are preferably microcapsules.
The particles (shell part) preferably have a hydrophilic surface.
The mass ratio of the shell part: core part is preferably in the range of 80:20 to 10:90, more preferably in the range of 70:30 to 20:80, and most preferably in the range of 60:40 to 25:75.

  In the present invention, the shell portion further contains a photothermal conversion agent in a range of 0.9 to 3 parts by mass with respect to 1 part by mass of the polymer. More preferably, the shell part contains the photothermal conversion agent in the range of 1.0 to 2 parts by mass relative to 1 part by mass of the polymer. The photothermal conversion agent may be disposed on the surface of the shell portion (that is, the particle surface). Moreover, the photothermal conversion agent may exist in the interface of a shell part and a core part.

[Photothermal conversion agent]
The photothermal conversion agent is a substance having a function of generating heat by absorbing light and converting light energy into heat energy. The light is preferably infrared light. In other words, the photothermal conversion agent is preferably an infrared absorber.
Pigments, dyes or metal fine particles that can absorb infrared light can be preferably used as the photothermal conversion agent. When microcapsules are used as the particles, it is particularly preferable to use an infrared absorbing dye as the photothermal conversion agent.

  As for infrared absorbing dyes, “Dye Handbook” edited by the Society of Synthetic Organic Chemistry, published in 1970, “Chemical Industry”, May 1986, p. Nos. 45 to 51, “Near-infrared absorbing dyes” and “Development and market trends of functional dyes in the 1990s”, Chapter 2, Section 2.3 (1990) CMC. Preferred infrared absorbing dyes are azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes (Japanese Patent Laid-Open Nos. 58-112793, 58-224793, 59-48187, 59-73996, 60- Nos. 52940 and 60-63744), anthraquinone dyes, phthalocyanine dyes (described in JP-A-11-235883), squarylium dyes (described in JP-A-58-112792), pyrylium dyes (US Pat. No. 3,881,924). No. 4283475, JP-A 57-142645, 58-181051, 58-220143, 59-41363, 59-84248, 59-84249, 59- No. 146063, No. 59-146061, No. 5-13514, JP-described No. 5-19702), a carbonium dye, quinone imine dyes and methine dyes (JP 58-173696, the same 58-181690 Patent, JP-described Nos. 58-194595).

  Infrared absorbing dyes are also described in US Pat. Nos. 4,756,993 and 5,156,938 and JP-A-10-268512. Commercially available infrared absorbing dyes (for example, Epolite III-178, Epolite III-130, Epolite III-125, manufactured by Eporin) may be used. The infrared absorbing dye is more preferably a methine dye, a cyanine dye (British Patent 434875, US Pat. No. 4,973,572, JP-A-58-125246, 59-84356, 59-216146, 60-78787)) is particularly preferable.

The cyanine dye is defined by the following formula (I).
(I) Bo-Lo = Bs
In the formula (I), Bs is a basic nucleus. A preferable basic nucleus (Bs) is represented by the following formula.

In the above formulas, X is —C (—R) ₂ —, —NR—, —O—, —S—, —Se— or —Te—. X is preferably —C (—R) ₂ —, —NR—, —O— or —S—, and particularly preferably —C (—R) ₂ —. In the above formulas and the definition of X, R is an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group. R is preferably an alkyl group or a substituted alkyl group. When two or more R exists in a formula, they may mutually differ. The alkyl group is preferably a chain alkyl group rather than a cyclic alkyl group. The chain alkyl group may have a branch. The alkyl group preferably has 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and most preferably 1 to 20 carbon atoms. The alkyl part of the substituted alkyl group is the same as the above alkyl group. Examples of the substituent of the substituted alkyl group include an alkylthio group (eg, methylthio, ethylthio), an arylthio group (eg, phenylthio), a halogen atom (chlorine atom, bromine atom, iodine atom, fluorine atom), nitro, alkoxy group ( Examples include methoxy, ethoxy), aryl groups (eg, phenyl), aryloxy groups (eg, phenoxy), amide groups, carbamoyl, sulfo, hydroxyl, carboxyl and cyano.

  The number of carbon atoms in the aryl group is preferably 6 to 40, more preferably 6 to 30, and most preferably 6 to 20. The aryl part of the substituted aryl group is the same as the above aryl group. Examples of the substituent of the substituted aryl group include an alkyl group (eg, methyl, ethyl), an alkylthio group (eg, methylthio, ethylthio), an arylthio group (eg, phenylthio), a halogen atom (chlorine atom, bromine atom, iodine atom) , Fluorine atom), nitro, alkoxy group (eg, methoxy, ethoxy), aryl group (eg, phenyl), aryloxy group (eg, phenoxy), amide group, carbamoyl, sulfo, hydroxyl, carboxyl and cyano.

  The basic nucleus may have a substituent other than R. Examples of basic nucleus substituents include alkyl groups (eg, methyl, ethyl), alkylthio groups (eg, methylthio, ethylthio), arylthio groups (eg, phenylthio), halogen atoms (chlorine atoms, bromine atoms, iodine atoms) , Fluorine atom), nitro, alkoxy group (eg, methoxy, ethoxy), aryl group (eg, phenyl), aryloxy group (eg, phenoxy), amide group, carbamoyl, sulfo, hydroxyl, carboxyl and cyano.

  In the formula (I), Bo is an onium body having a basic nucleus. A preferable onium body (Bo) having a basic nucleus is represented by the following formula.

In the above formulas, X is —CR ₂ —, —NR—, —O—, —S—, —Se— or —Te—. X is preferably —CR ₂ —, —NR—, —O— or —S—, and particularly preferably —CR ₂ —. In the above formulas and the definition of X, R is an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group. R is preferably an alkyl group or a substituted alkyl group. When two or more R exists in a formula, they may mutually differ. The definitions and examples of the alkyl group, the substituted alkyl group, the aryl group, and the substituted aryl group are the same as those in the basic nucleus (Bs). The onium body of the basic nucleus may have a substituent other than R. The example of the substituent of the onium body of a basic nucleus is the same as the example of the substituent of a basic nucleus (Bs).

  The cyanine dye generally contains an anion as a counter ion of an onium body (cation) of a basic nucleus. However, the cyanine dye may have one anionic substituent and form an inner salt. In addition, the cyanine dye may have a plurality of anionic substituents and may further contain a cation as a charge neutralizing ion. That is, the type (cation or anion) and number of charge neutralizing ions are determined according to the type and number of dissociable groups of the cyanine dye. Anions include halide ions (eg, chlorine ions, bromine ions, fluorine ions, iodine ions), aryl sulfonate ions (eg, paratoluene sulfonate ions), alkyl sulfate ions (eg, methyl sulfate ions), sulfate ions, Perchlorate ions, tetrafluoroborate ions and acetate ions are preferred. As the cation, alkali metal ions (eg, sodium ion, potassium ion) and ammonium ions (eg, triethylammonium ion, pyridinium ion, 1-ethylpyridinium ion) are preferable.

  In the formula (I), Lo is a methine chain containing an odd number of methines. The number of methines is preferably 3, 5, 7 or 9, more preferably 5 or 7, and most preferably 7. The methine chain may have a substituent. Two or more methine chain substituents may combine to form an unsaturated aliphatic ring (eg, cyclopentene ring, cyclohexene ring, isophorone ring) or aromatic ring (eg, squarylium ring, croconium ring). When the methine chain has one substituent, the one substituent is preferably bonded to the methine at the center (meso position) of the methine chain. Examples of methine chains containing 7 methines are shown below.

In the above formulas, R ¹ and R ² are each independently a hydrogen atom, a halogen atom (chlorine atom, bromine atom, iodine atom, fluorine atom), hydroxyl, mercapto, amino, alkyl group, substituted alkyl group, aryl group , A substituted aryl group, —O—R, —S—R, —NH—R or —N (—R) ₂ , wherein R is an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group. The definitions and examples of the alkyl group, the substituted alkyl group, the aryl group, and the substituted aryl group are the same as those in the basic nucleus (Bs). As the cyanine dye, a compound obtained by arbitrarily combining the basic nucleus, the onium body of the basic nucleus and the methine chain described above can be used. However, it is preferable for the convenience of synthesis that the basic nucleus (Bs) and the onium body (Bo) of the basic nucleus have chemical structures corresponding to each other.
Two or more photothermal conversion agents may be used in combination.

Further, as a similar infrared absorbing dye, the phthalocyanine dye described in JP-A-11-235883 mentioned above is particularly preferably used.
The phthalocyanine dye is defined by the following general formula (II).

(Wherein R _{1 to} R ₈ represent an alkyl group or an alkoxyalkyl group, X _{1 to} X ₈ represent a sulfur atom or NR ₉ , and X ₁ = (one of X ₃ and X ₄ ) = (X ₅ or X ₆ ) = (one of X ₇ or X ₈ ) = a sulfur atom and X ₂ = (the other of X ₃ or X ₄ ) = (the other of X ₅ or X ₆ On the other hand, = (the other of X ₇ and X ₈ ) = NR _9. R ₉ represents a hydrogen atom or an alkyl group, M represents two hydrogen atoms, a divalent metal, a trivalent metal derivative or 4 A valent metal derivative.)

When R _{1 to} R ₈ are alkyl groups, a linear or branched alkyl group having 1 to 12 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 8 carbon atoms is particularly preferable. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, sec -Hexyl group, 2-ethylbutyl group, n-heptyl group, isoheptyl group, sec-heptyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group can be mentioned.

When R _{1 to} R ₈ are alkoxyalkyl groups, those having 2 to 6 carbon atoms are preferred. Examples include methoxyethyl group, methoxypropyl group, methoxybutyl group, ethoxyethyl group, ethoxypropyl group, ethoxybutyl group, n-propoxyethyl group, iso-propoxyethyl group, and n-propoxypropyl group.

As R ₉ being an alkyl group, a linear or branched alkyl group having 1 to 12 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 8 carbon atoms is particularly preferable. Examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, neopentyl, n-heptyl, isoheptyl, sec -A heptyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group is mentioned. Therefore, R ₉ is preferably a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, and particularly preferably a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms.

As M being a divalent metal, Cu, Zn, Fe, Co, Ni, Ru, Pb, Rh, Pd, Pt, Mn, and Sn are preferable, and as a trivalent or tetravalent metal derivative, AlCl , InCl, FeCl, MnOH, SiCl 2, SnCl 2, GeCl 2, Si (OH) 2, Sn (OH) 2, Ge (OH) 2, VO, TiO is preferred. M is particularly preferably Co, Ni, Cu, Zn, VO, or TiO.

[Microcapsule]
As described above, the particles are preferably microcapsules.
Microcapsules can be produced by a known method. It is preferable to prepare microcapsules by an interfacial polymerization method or an in situ polymerization method, and it is more preferable to manufacture microcapsules by an interfacial polymerization method because of the ease of manufacture and the ease of equipment.

  The wall material of the microcapsule is the same as the wall material used in a known microcapsule manufacturing method. Specific examples of the wall material include polyurethane resin, polyurea resin, polyamide resin, polyester resin, polycarbonate resin, aminoaldehyde resin, melamine resin, polystyrene resin, styrene-acrylate copolymer resin, gelatin, polyvinyl alcohol and the like. Two or more kinds of wall materials may be used in combination. Polyurethane / polyurea resin is particularly preferred.

  In microcapsule production using polyurethane / polyurea resin as a wall material by interfacial polymerization method, wall materials such as polyisocyanate are mixed in an oil phase containing a core material to be encapsulated, and protective colloid materials such as polyvinyl alcohol are dissolved. It is prepared by emulsifying and dispersing in a water-based medium and raising the liquid temperature to cause a polymer formation reaction at the oil droplet interface. The core substance may be an oil phase containing a hydrophobic compound or the hydrophobic compound itself. Moreover, in this invention, it is necessary to add an infrared absorber in a core substance or a wall material.

  Examples of the polyvalent isocyanate compound are m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4′-diisocyanate. 3,3′-diphenylmethane-4,4′-diisocyanate, xylene-1,4-diisocyanate, 4,4′-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene- Diisocyanates such as 1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, 4,4 ′, 4 ″ -triphenylmethane Triisocyanates such as reisocyanate, toluene-2,4,6-triisocyanate, tetraisocyanates such as 4,4′-diphenylmethane-2,2 ′, 5,5′-tetraisocyanate, hexamethylene diisocyanate and trimethylol Includes isocyanate prepolymers such as adducts with propane, adducts of 2,4-tolylene diisocyanate and trimethylol propane, adducts of xylylene diisocyanate and hexanetriol, etc. Two or more types can be used as required Those having three or more isocyanate groups in the molecule are preferred.

  An organic solvent can be added to assist dissolution of the polyvalent isocyanate compound in the core material. Specific examples of preferable organic solvents include ethyl acetate, isopropyl acetate, butyl acetate, methylene chloride, cyclohexanone, acetone, methyl ethyl ketone, and the like. Particularly preferably, ethyl acetate is used, but the organic compounds are not limited to the above compounds. Absent.

  As the protective colloid used on the dispersion medium side in the microencapsulation, various protective colloids such as gelatin, gelatin derivatives, cellulose derivatives such as polyvinyl alcohol and hydroxymethylcellulose, and casein can be used.

  Furthermore, an appropriate auxiliary agent can be added for the purpose of promoting the wall film formation reaction of polyisocyanates and controlling the physical properties of the formed polyurethane / polyurea film. Specific examples include a phenol compound, an alcohol compound, an amine compound, an amide compound, a sulfonamide compound, and the like. These may be contained in the core material or in the dispersion medium.

[Technology for incorporating photothermal conversion agent in microcapsule shell]
It is preferable that the photothermal conversion agent contained in the microcapsule is dispersed in the shell portion as in the lithographic printing plate precursor disclosed in JP-A-2004-90437. However, in the technique disclosed in Japanese Patent Application Laid-Open No. 2004-90437, where the photothermal conversion agent is chemically bonded to the microcapsule wall material (shell member), the amount of photothermal conversion necessary for the present invention is required due to the problem of synthesis. It is difficult to contain the agent in the shell part. In the method of adding a photothermal conversion agent to the oil phase in the microcapsule synthesis, when the core substance is a good solvent for the photothermal conversion agent, the photothermal conversion agent is not only contained in the shell part but also in the core part in the synthesized microcapsule. Further, the amount of photothermal conversion agent in the shell portion is less than the charged amount as a result of diffusion and dissolution, so that a desired amount of heat energy cannot be obtained during exposure.

  As a method for solving this problem, use a poor solvent or low compatibility material of the photothermal conversion agent as the core material, and add an auxiliary solvent to help dissolve the photothermal conversion agent / core material in the oil phase. A phase is preferred. That is, by using such a combination of a core material, a photothermal conversion agent, and an auxiliary solvent, in the synthesized microcapsule, the photothermal conversion agent does not diffuse and dissolve in the core material of the microcapsule, and the polyurethane / polyurea wall And microcapsules abundantly contained at the wall interface can be obtained.

Although it is difficult to clearly define the concept of poor solvent / good solvent here, it is possible to use an I / O value and an organic conceptual diagram as qualitative indicators.
The above I / O values and organic concept diagrams are: Yoshio Koda "Organic Conceptual Diagrams-Fundamentals and Applications" (Sankyo Publishing, 1984), Satoshi Fujita and Masami Akatsuka "Systematic Organic Qualitative Analysis (mixture)" (Kazama Shobo, 1974), an integer value obtained by qualitatively quantifying organicity and inorganicity, and a value obtained by dividing the value representing inorganicity by the value representing organicity. It is the graph which took the value which represents the value and the inorganic property on the orthogonal axis. In the present invention, the I / O value of 0 means that it has no inorganicity, that is, the value representing the inorganicity is 0. With this I / O value and the organic conceptual diagram, it is possible to qualitatively evaluate the compatibility between two different substances, for example, the photothermal conversion agent and the core substance.

Specifically, utilizing the high I / O value compound of the cyanine dye and phthalocyanine dye preferably used in the present invention, a low I / O value compound such as an olefin or a higher alkyl compound is used as the core material. It is mentioned as a preferable example. The difference in I / O value is preferably 0.2 or more, more preferably 0.3 or more, and most preferably 0.5 or more. As is clear from the above, the I / O value of the hydrophobic compound is photothermal. It is preferably below the I / O value of the conversion agent.
Further, a compound that easily aggregates, in other words, a self-aggregating compound, for example, a compound known as a liquid crystal compound, a compound having a hydrogen bonding group such as an OH group, and the like can be preferably used as the core substance. In particular, a method using a low I / O value compound and a liquid crystal compound that are completely encapsulated in a microcapsule is most preferably used.
As specific examples of these core substances, those described as hydrophobic compounds described later are preferably used.

  As the auxiliary solvent, a good solvent of the above-mentioned cyanine dye and phthalocyanine dye preferably used as a photothermal conversion agent is preferable, and it is necessary for the microcapsule synthesis method to be compatible with the core substance described later. Specific examples of preferable solvents include ethyl acetate, isopropyl acetate, butyl acetate, methylene chloride, cyclohexanone, acetone, methyl ethyl ketone, and the like, which are preferably used to assist the dissolution of the core material and the polyvalent isocyanate compound, and diisopropyl ether. , Ethylene glycol dimethyl ether, chloroform and the like can be used, and ethyl acetate is particularly preferably used. In addition, acetonitrile, tetrahydrofuran, ethanol, isopropyl alcohol, and the like can be used by mixing with the above solvent.

[Hydrophobic compounds]
The hydrophobic compound has a function of making the vicinity of the particle hydrophobic by being released from the particle. Two or more types of hydrophobic compounds can be used. In particular, since these hydrophobic compounds play a role as the core material of microcapsules, it is preferable in the present invention to have the property of being a poor solvent for the above-mentioned cyanine dyes and phthalocyanine dyes. Examples thereof include low I / O value compounds and liquid crystal compounds. Among them, a low polarity, low I / O value compound is particularly preferable. More preferably, the hydrophobic compound has an I / O value of 0 to 0.5.

[Low polarity, low I / O value compounds]
Specific examples of such hydrophobic compounds include alkanes and alkynes having 7 or more carbon atoms, aryls, esters having 8 or more carbon atoms, and the above-described compounds having a halogen, an alkyloxy group, or an alkyl mercapto group. The compound etc. which were provided are mentioned.

  Specific examples of the alkanes having 7 or more carbon atoms and the cyclic alkanes include n-heptane, 2-methylhexane, 3-methylhexane, methylcyclohexane, 1-heptene, 2-heptene, n-octane, 2, 2-dimethylhexane, 2-methylheptane, cyclooctane, cyclooctene, 1,2-dimethylcyclohexane, 1-octene, n-nonane, isopropylcyclohexane, 2,3-dimethylheptane, n-decane, butylcyclohexane, decalin, Examples include n-undecane, n-dodecane, bicyclohexyl, n-tridecane and the like. These structural isomers can also be used.

  Examples of the aryls include benzenes (the following general formula (I)), naphthalenes (the following general formula (II)), biphenyls (the following general formula (III)), diphenylmethanes (the following general formula (IV)) , Anthracene (the following general formula (V)), and phenanthrene (the following general formula (VI)). In particular, toluene, p-xylene, m-xylene, o-xylene, mesitylene, styrene, 4-methylstyrene, 4-tert-butylstyrene, divinylbenzene, 2,7-diisopropylnaphthalene, and diphenylmethane are preferably used.

(R _{1 to} R ₁₀ represent any one of H, an alkyl group, an aryl group, a vinyl group, a halogen (F, Cl, Br, I), an alkyloxy group, a vinyloxy group, and an alkyl mercapto group, and R ₁₁ and R ₁₂ represent H, an alkyl group, an aryl group, or a vinyl group.

  The hydrophobizing compound used in the present invention preferably further contains a polymerizable group, and as such a polymerizable group, an ethylenically unsaturated double bond is particularly preferable. A compound having at least one, preferably two or more, ethylenically unsaturated double bonds in the hydrophobized compound is preferably used. These can have chemical forms such as monomers, prepolymers, ie dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, etc.) and esters thereof, preferably unsaturated carboxylic acids. A group of compounds such as an ester of an aliphatic polyhydric alcohol compound, an unsaturated phosphonic acid, styrene, and vinyl ether can be used. In addition, unsaturated carboxylic acid esters having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group, and addition reaction product of styrene, vinyl ether with monofunctional or polyfunctional isocyanates or epoxies, and A dehydration condensation reaction product with a monofunctional or polyfunctional carboxylic acid is also preferably used. In addition, unsaturated carboxylic acid esters having an electrophilic substituent such as an isocyanate group or an epoxy group, or addition reaction products of styrene, vinyl ethers with monofunctional or polyfunctional alcohols, amines, thiols, and halogens. An unsaturated carboxylic acid ester having a group or a leaving substituent such as a tosyloxy group, or a substitution reaction product of styrene or vinyl ether with a monofunctional or polyfunctional alcohol, amine or thiol is also suitable.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, 1,3-butanediol diacrylate, propylene glycol diacrylate, and neopentyl glycol diester. Acrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, Examples include polyester acrylate oligomers.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, hexanediol dimethacrylate, penta Erythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, bis [p- (3-methacryloxy-2-hydroxypropoxy) phenyl] dimethylmethane, bis- [p- (methacryloxyethoxy) phenyl] dimethylmethane, etc. There is.

  Examples of itaconic acid esters include 1,3-butanediol diitaconate and 1,4-butanediol diitaconate. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, and pentaerythritol dicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate and pentaerythritol diisocrotonate.

  Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, JP-A-59-5241. Also preferred are those having an I / O value in the range of 0 to 0.8 selected from those having an aromatic skeleton described in JP-A-2-226149, those containing an amino group described in JP-A-1-165613, and the like. Used for. Furthermore, the ester monomers described above can also be used as a mixture.

[Liquid crystal compounds]
Specific examples of such liquid crystal compounds are described below. The melting point of such a liquid crystal compound is preferably 30 to 300 ° C, more preferably 50 to 270 ° C, further preferably 70 to 240 ° C, and most preferably 90 to 210 ° C.
The liquid crystal compound is preferably a rod-like liquid crystal compound or a discotic liquid crystal compound. The liquid crystal compound may be a polymer liquid crystal.

Examples of rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferred.
The rod-like liquid crystal compound includes a metal complex. Moreover, the liquid crystal polymer which contains a rod-shaped liquid crystalline compound in a repeating unit can also be used as a rod-shaped liquid crystalline compound. In other words, the rod-like liquid crystalline compound may be bonded to a (liquid crystal) polymer.
For rod-like liquid crystalline compounds, see Chapter 4, Chapter 7 and Chapter 11 of the Chemistry of the Quarterly Chemical Review Vol. 22 Liquid Crystal Chemistry (1994) edited by the Chemical Society of Japan, and the 142nd Committee of the Japan Society for the Promotion of Science. Described in Chapter 3.
The rod-like liquid crystalline compound preferably has a polymerizable group. The polymerizable group is preferably radically polymerizable or cationically polymerizable. Examples of the polymerizable group (Q) are shown below.

The polymerizable group is preferably an unsaturated group (Q1 to Q7) or an epoxy group (Q8), and most preferably an ethylenically unsaturated group (Q1 to Q6) or an epoxy group (Q8).
The rod-like liquid crystalline compound preferably has two polymerizable groups at both ends of the rod-like molecular structure.

A discotic liquid crystal compound is more preferable than a rod-like liquid crystal compound. That is, the liquid crystal compound preferably has many polymerizable groups. A discotic liquid crystalline compound (generally capable of introducing four or more polymerizable groups) has more polymerizable groups than a rod-shaped liquid crystalline compound (generally, the number of polymerizable groups is two or less). be able to.
Examples of the discotic liquid crystalline compound include C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physics lett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and cyclohexane derivatives described in J. Am. M. Lehn et al. Chem. Commun. 1794 (1985); Zhang et al., J. Am. Chem. Soc. 116, page 2655 (1994), and azacrown and phenylacetylene macrocycles.

A discotic liquid crystalline compound is a compound having a general molecular structure in which a linear alkyl group, an alkoxy group, or a substituted benzoyloxy group is substituted radially with respect to the mother nucleus at the center of the molecule. , Showing liquid crystallinity.
Examples of the discotic liquid crystalline compound are described in JP-A-8-50206. The discotic liquid crystalline compound having a polymerizable group is described in JP-A-8-27284.

    An example of the disk-shaped core (D) is shown below. In each of the following examples, LQ (or QL) means a combination of a divalent linking group (L) and a polymerizable group (Q).

  The divalent linking group (L) is a divalent linking group selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —CO—, —NH—, —O—, —S—, and combinations thereof. Preferably there is. The divalent linking group (L) is a divalent combination of at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO-, -NH-, -O-, and -S-. More preferably, it is a linking group. The divalent linking group (L) is most preferably a divalent linking group in which at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO- and -O- are combined. . The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The number of carbon atoms in the arylene group is preferably 6 to 10.

Examples of the divalent linking group (L) are shown below. The left side is bonded to the discotic core (D), and the right side is bonded to the polymerizable group (Q). AL represents an alkylene group or an alkenylene group, and AR represents an arylene group. The alkylene group, alkenylene group and arylene group may have a substituent (eg, an alkyl group).
L1: -AL-CO-O-AL-
L2: -AL-CO-O-AL-O-
L3: -AL-CO-O-AL-O-AL-
L4: -AL-CO-O-AL-O-CO-
L5: -CO-AR-O-AL-
L6: -CO-AR-O-AL-O-
L7: -CO-AR-O-AL-O-CO-
L8: -CO-NH-AL-
L9: -NH-AL-O-
L10: -NH-AL-O-CO-

L11: -O-AL-
L12: -O-AL-O-
L13: -O-AL-O-CO-
L14: -O-AL-O-CO-NH-AL-
L15: -O-AL-S-AL-
L16: -O-CO-AR- (O-AL) m-
L17: -O-CO-AR- (O-AL) m-O-
L18: -O-CO-AR- (O-AL) m-CO-
L19: -O-CO-AR- (O-AL) m-O-CO-
L20: -S-AL-

L21: -S-AL-O-
L22: -S-AL-O-CO-
L23: -S-AL-S-AL-
L24: -S-AR-AL-
(Ii) m: an integer from 1 to 6

The polymerizable group (Q) of the formula (I) is the same as the definition and examples of the polymerizable group (Q) described in the rod-like liquid crystal compound.
The polymerizable group is preferably an unsaturated group (Q1 to Q7) or an epoxy group (Q8), and most preferably an ethylenically unsaturated group (Q1 to Q6) or an epoxy group (Q8).
In the formula (I), n is an integer of 4 to 12. A specific number is determined according to the type of the disk-shaped core (D). In addition, although the combination of several L and Q may differ, it is preferable that it is the same.

[Hydrophilic layer]
The hydrophilic layer preferably contains a hydrophilic polymer outside the particles. The hydrophilic polymer functions as a hydrophilic binder. The hydrophilic polymer is preferably crosslinked.

  The hydrophilic polymer is preferably a sol-gel converting material composed of a metal hydroxide and a metal oxide system, and among them, the sol-gel converting system having the property of forming a polysiloxane gel structure is the most. preferable. When the hydrophilic layer on the surface of the particles having a hydrophilic surface also has a function as a binder, the binder may not be newly used. The binder acts as a dispersion medium for the constituent components of the hydrophilic layer, improving the physical strength of the layer, improving the dispersibility between the components constituting the layer, improving the coatability, improving the printability, and improving the plate making workability. The structure is suitable for various purposes such as convenience.

  As the hydrophilic polymer, there can be used an organic polymer compound having a hydroxyl group for the purpose of imparting appropriate strength and surface hydrophilicity as an image recording layer. Specifically, polyvinyl alcohol (PVA), modified PVA such as carboxy-modified PVA, starch and derivatives thereof, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, casein, gelatin, polyvinylpyrrolidone, vinyl acetate-crotonic acid Polymers, styrene-maleic acid copolymers, polyacrylic acid and salts thereof, polyacrylamides, and water-soluble acrylic copolymers containing water-soluble acrylic monomers such as acrylic acid and acrylic amide as main components Water-soluble resin is mentioned.

  Examples of water resistance agents that crosslink and cure the organic polymer compound having a hydroxyl group include initial condensates of aminoplasts such as glyoxal, melamine formaldehyde resin, urea formaldehyde resin, methylolated polyamide resin, polyamide / polyamine / epichlorohydride. Examples thereof include phosphorus adducts, polyamide epichlorohydrin resins, and modified polyamide polyimide resins. In addition, ammonium chloride, a crosslinking catalyst for a silane coupling agent, and the like can be used in combination.

  In the system capable of sol-gel conversion, the bonding group coming out of the polyvalent element forms a network structure through the oxygen atom, and the polyvalent metal also has an unbonded hydroxyl group or alkoxy group. Is a polymer that has a resinous structure, and is in a sol state when there are many alkoxy groups and hydroxyl groups before coating, and a network-like resin as ester bonding proceeds after coating. The structure becomes strong and becomes a gel state. Further, in addition to the property of changing the hydrophilicity of the resin structure, it also has a function of modifying the surface of the solid fine particles by bonding a part of the hydroxyl groups to the solid fine particles 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 a siloxane bond 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.

  Hereinafter, a system using sol-gel conversion will be further described. The hydrophilic matrix formed by sol-gel conversion is preferably a resin having a siloxane bond and a silanol group, and the image recording layer of the lithographic printing plate precursor of the present invention contains a silane compound having at least one silanol group. The coating solution, which is a sol system, is formed by the progress of hydrolysis and condensation of silanol groups to form a siloxane skeleton structure and gelation during the time after coating. The siloxane resin forming the gel structure is represented by the following general formula (I), and the silane compound having at least one silanol group is represented by the following general formula (II). In addition, the substance system contained in the image recording layer that changes from hydrophilicity to hydrophobicity does not necessarily need to be a silane compound of the general formula (II) alone, and generally consists of an oligomer in which the silane compound is partially hydrolyzed. Alternatively, it may be a mixed composition of a silane compound and its oligomer.

The siloxane-based resin of the general formula (I) is formed by sol-gel conversion from a dispersion containing at least one silane compound represented by the following general formula (II), and R ⁰¹ in the general formula (I) At least one to R ⁰³ represents a hydroxyl group and the other represents an organic residue selected from R ⁰ and Y ¹ symbols in the following general formula (II).

Formula (II)
(R ⁰ ) _n Si (Y ¹ ) _4-n
In general formula (II), R ⁰ represents a hydroxyl group, a hydrocarbon group or a heterocyclic group. Y ¹ represents a hydrogen atom, a halogen atom, —OR ¹¹ , —OCOR ¹² , or —N (R ¹³ ) (R ¹⁴ ) (R ¹¹ and R ¹² each represent a hydrocarbon group, R ¹³ , R ¹⁴ may be the same or different and each represents a hydrogen atom or a hydrocarbon group). n represents 0, 1, 2 or 3.

Examples of the hydrocarbon group or heterocyclic group represented by R ^{0 in} the general formula (II) include a linear or branched alkyl group having 1 to 12 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, etc .; as a group substituted by these groups, a halogen atom (chlorine atom, fluorine atom, bromine 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) Group, propenyl group, butenyl group, hexenyl group, octenyl group, 2-hydroxyethyl group, 3-chloropropyl group, 2-cyanoethyl group, N, N-dimethylaminoethyl group, 2 Bromoethyl group, 2- (2-methoxyethyl) oxyethyl group, 2-methoxycarbonylethyl group, 3-carboxypropyl group, a benzyl group),

—OCOR ″ group (R ″ represents the same content as R ″), —COOR ″ group, —COR ″ group, —N (R ′ ″) (R ″ ″) (R ′ '' Represents a hydrogen atom or the same content as R ′, and each may be the same or different), —NHCONHR ″ group, —NHCOOR ″ group, —Si (R ″) ₃ group, —CONHR ′ ″ Group, —NHCOR ″ group, and the like. These substituents may be substituted in plural in an alkyl group), a linear or branched alkenyl group having 2 to 12 carbon atoms (which may be substituted). For example, as a group substituted by these groups, such as a vinyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, an octenyl group, a decenyl group, and a dodecenyl group, the same content as the group substituted by the alkyl group And an optionally substituted aralkyl having 7 to 14 carbon atoms. Group (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, etc.). The group substituted by these groups is the same as the group substituted by the alkyl group. Content may be included, or multiple substitutions may be made)

  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 contents 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, a phenyl group or a naphthyl group). , The substituent includes the same content as the group substituted with the alkyl group, and may be substituted plurally), or at least one selected from a nitrogen atom, an oxygen atom, and a sulfur atom A heterocyclic group containing an atom and may be condensed (for example, the heterocyclic ring includes a pyran ring, a furan ring, a thiophene ring, a morpholine ring, a pyrrole ring, a thiazole ring, A xazole ring, a pyridine ring, a piperidine ring, a pyrrolidone ring, a benzothiazole ring, a benzoxazole ring, a quinoline ring, a tetrahydrofuran ring, etc. may contain a substituent, such as a substituent in the alkyl group, Those having the same contents may be mentioned, and a plurality of them may be substituted).

As the —OR ¹¹ group, —OCOR ¹² group or —N (R ¹³ ) (R ¹⁴ ) group of Y ^{1 in} the general formula (II), for example, the following groups are represented. In the —OR ¹¹ group, R ¹¹ is an optionally substituted aliphatic group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butoxy 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, 2- (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 A benzyl group, bromobenzyl group, and the like).

In the —OCOR ¹² group, R ¹² is an aliphatic group having the same content as R ¹¹ or an optionally substituted aromatic group having 6 to 12 carbon atoms (the aromatic group is exemplified by the aryl group in R above). The same as the above). In the —N (R ¹³ ) (R ¹⁴ ) group, R ¹³ and R ¹⁴ 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, And those having the same contents as R ¹¹ of the —OR ¹¹ group. More preferably, the total number of carbon atoms of R ¹¹ and R ¹² is 16 or less. Specific examples include, but are not limited to, the following.

  Examples of the silane compound represented by the general formula (II) where n = 0 are tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane, and triethoxy. Silane, tribromosilane, trimethoxysilane, isopropoxysilane, tri (t-butoxy) silane are included.

Examples of the silane compound represented by the general formula (II) in which n = 1 and R ⁰ is an alkyl group are methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxy Silane, methyltri (t-butoxy) silane, ethyltrichlorosilane, ethyltribromosilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri (t-butoxy) silane, propyltrichlorosilane, propyltribromo Silane, propyltrimethoxysilane, propyltriethoxysilane, propyltriisopropoxysilane, propyltri (t-butoxy) silane, hexyltrichlorosilane, hexyltribromosilane, hexyltrimethoxysilane, Hexyltriethoxysilane, hexyltriisopropoxysilane, hexyltri (t-butoxy) silane, decyltrichlorosilane, decyltribromosilane, decyltrimethoxysilane, decyltriethoxysilane, decyltriisopropoxysilane, decyltri (t-butoxy) Silane, octadecyltrichlorosilane, octadecyltribromosilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, octadecyltriisopropoxysilane, octadecyltri (t-butoxy) silane are included.

Examples of the silane compound represented by the general formula (II) in which n = 1 and R ⁰ is an aryl group are phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxy Silane, phenyltri (t-butoxy) silane is included.
Examples of the silane compound represented by the general formula (II) in which n = 1 and R ⁰ is an alkenyl group are vinyltrichlorosilane, vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxy. Silane and vinyltri (t-butoxy) silane are included.

Examples of the silane compound represented by the general formula (II) in which n = 1 and R ⁰ is a substituted alkyl group include trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoropropyltrimethoxysilane, trifluoro Propyltriethoxysilane, trifluoropropyltriisopropoxysilane, trifluoropropyltri (t-butoxy) silane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, γ-glycidyloxypropyltriisopropoxy Silane, γ-glycidyloxypropyltri (t-butoxy) silane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriisopropoxysilane, γ-methacryloyloxy Propyltri (t-butoxy) silane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltri (t-butoxy) silane, γ-mercaptopropyltri Methoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri (t-butoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- ( 3,4-epoxycyclohexyl) ethyltriethoxysilane.

  Examples of silane compounds represented by the general formula (II) where n = 2 are dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldichlorosilane, diphenyldibromosilane, diphenyldimethoxysilane, diphenyldi Ethoxysilane, phenylmethyldichlorosilane, phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, γ-glycidyloxypropylmethyldimethoxysilane, γ-glycidyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxy Silane, γ-methacryloyloxypropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldi Including Tokishishiran, .gamma.-mercaptopropyl methyl dimethoxy silane, a .gamma.-mercaptopropyl methyldiethoxysilane.

In addition to the silane compound represented by the general formula (II) used for forming the image recording layer of the present invention, a metal compound capable of forming a film by bonding to a resin during sol-gel conversion, such as Ti, Zn, Sn, Zr, Al, etc. Can be used in combination. Examples of the metal compound used include Ti (OR ″) ₄ (R ″ is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, etc.), TiCl ₄ , Zn (OR ″) ₂ , Zn ( CH ₃ COCHCOCH ₃ ) ₂ , Sn (OR ″) ₄ , Sn (CH ₃ COCHCOCH ₃ ) ₄ , Sn (OCOR ″) ₄ , SnCl ₄ , Zr (OR ″) ₄ , Zr (CH ₃ COCHCOCH ₃ ) ₄ , Al (OR ") ₃ etc. are mentioned.

  In addition, this gel structure matrix has a silane coupling group at the end of the polymer main chain for the purpose of improving physical properties such as film strength and flexibility, improving coating properties, and adjusting hydrophilicity. It is possible to add a hydrophilic polymer or a crosslinking agent.

  Examples of the hydrophilic polymer having a silane coupling group at the end of the polymer main chain include a polymer represented by the following general formula (1).

In the general formula (1), R ¹ , R ² , R ³ and R ⁴ each represent a hydrogen atom or a hydrocarbon group having 8 or less carbon atoms, m represents 0, 1 or 2, and n represents 1-8. An integer is represented, and p represents an integer of 30 to 300. Y represents —NHCOCH ₃ , —CONH ₂ , —CON (CH ₃ ) ₂ , —CONH ₃ , —OCH ₃ , —OH, —CO ₂ M or —CONHC (CH ₃ ) ₂ SO ₃ M, and M represents hydrogen. It represents one selected from the group consisting of atoms, alkali metals, alkaline earth metals and onium.

  L represents a single bond or an organic linking group. Here, the organic linking group represents a polyvalent linking group composed of a nonmetallic atom, specifically 1 to 60 carbon atoms, 0 to 10 carbon atoms. A nitrogen atom, 0 to 50 oxygen atoms, 1 to 100 hydrogen atoms, and 0 to 20 sulfur atoms. More specific examples of the linking group include the following structural units or groups formed by combining them.

  Specific examples of the hydrophilic polymer having a silane coupling group of the general formula (1) include the following polymers. In the specific examples below, p can be any value between 100 and 250.

  The hydrophilic polymer is radical polymerization using a radical polymerizable monomer represented by the following general formula (2) and a silane coupling agent having chain transfer ability in the radical polymerization represented by the following general formula (3). Can be synthesized. Since the silane coupling agent (formula 3) has chain transfer ability, it is possible to synthesize a polymer in which a silane coupling group is introduced at the end of the polymer main chain in radical polymerization.

[Solid fine particles]
The hydrophilic matrix contained in the hydrophilic layer on the printing original plate according to the present invention preferably further contains solid fine particles, and the hydrophilic polymer having the silane coupling group is chemically bonded to the surface of the solid fine particles. Preferably, they are present in a bonded form. Moreover, it is also preferable to include a form in which a hydrophilic polymer other than the above is bonded to the surface. In the present specification, the chemical bonding of a hydrophilic polymer to the surface of solid particles is also referred to as surface modification.

  The solid particles to which the hydrophilic polymer binds are preferably metal oxide fine particles, such as metal oxides such as zinc oxide, titanium dioxide, iron oxide, zirconia; anhydrous silicic acid, hydrous calcium silicate, hydrous aluminum silicate, etc. As such, silicon-containing oxides that do not absorb in the visible range (also called white carbon), clay mineral particles such as clay, talc, kaolin, and fluorite can be used.

  The average particle size of the inorganic particles is preferably 10 μm or less, more preferably 5 nm to 5 μm, still more preferably 10 nm to 5 μm. Within this range, it is possible to stably produce the photocrosslinkable particles described below, maintain good adhesion to the support, and keep particles near the surface well. Is done.

  Of these inorganic particles, silicon-containing oxides are particularly preferred from the viewpoints of hydrophilicity and film strength, and ease of surface modification with a hydrophilic polymer. Specifically, Snowtex ZL (particle size 70-100 nm silica 40% colloidal aqueous solution) manufactured by Nissan Chemical Industries, Ltd., Silicia 350 (particle size 3.5 μm) manufactured by Fuji Silysia Chemical Ltd., Nippon Aerosil Co., Ltd. AEROSIL130 (particle size: 160 nm silica) manufactured by Nippon Aerosil Co., Ltd., AEROSIL200 (particle size: 16 nm silica) manufactured by Mizusawa Chemical Co., Ltd., Mizukasil P-527U (particle size: 60 nm silica), and the like are included.

  The particle diameters of the surface-modified or non-surface-modified surface-solubilized sol-like particles used in the present invention (collectively, these may be simply referred to as silica particles) are within the above range. In the above, the film strength of the image recording layer is sufficiently maintained, and the film is exposed to a laser beam or the like to make a plate, and when printed as a printing plate, it has excellent hydrophilicity so that no printing ink adheres to the non-image area. The effect of becoming. Moreover, when adding hydrophilic sol-like particle | grains to an image recording layer, the addition amount is 5-80 mass% of the fixed material component of an image recording layer, Preferably it is 20-60 mass%.

[Surface modification with hydrophilic polymer]
Surface modification with a hydrophilic polymer can be produced by appropriately applying conventionally known methods. For example, a hydrophilic polymer having a silane coupling group at the polymer main chain terminal can be used to easily introduce the hydrophilic polymer onto the surface of the silica particles by a sol-gel reaction.

  The hydrophilic polymer that can be used is not particularly limited, but it is particularly preferable that the hydrophilic polymer contains a hydrophilic polymer containing a silane coupling group represented by the general formula (1). As the hydrophilic functional group possessed by the hydrophilic polymer, in addition to the substituents Y and LY of the general formula (1), a carboxylic acid group, a sulfonic acid group, a sulfinic acid group, a phosphonic acid group, an amino group, and salts thereof Amide group, hydroxyl group, ether group, polyoxyethylene group and the like.

  Therefore, as a method of modifying the surface with a hydrophilic polymer having a silane coupling group, in addition to the method of directly bonding the polymer represented by the general formula (1) to the solid fine particles, a silane having a polymerization initiation ability on the silica surface. A method of treating with a coupling agent and then graft polymerization reaction of a hydrophilic monomer can be mentioned, whereby surface-modified particles modified with a hydrophilic polymer can be obtained.

  Examples of the hydrophilic monomer that can be used include the following monomers. For example, (meth) acrylic acid or alkali metal salts and amine salts thereof, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol (meth) acrylamide, N-dimethylol (meth) acrylamide, allylamine or the like Hydrohalide, 3-vinylpropionic acid or its alkali metal salt and amine salt, vinylsulfonic acid or its alkali metal salt and amine salt, 2-sulfoethylene (meth) acrylate, 3-sulfopropylene (meth) acrylate or Alkali metal salts and amine salts thereof, polyoxyethylene glycol mono (meth) acrylate, 2-acrylamido-2-methylpropane sulfonic acid or alkali metal salts and amine salts thereof, acid phosphooxypolyoxy Carboxyl group, sulfonic acid group, phosphoric acid, amino group or their salts, such as ethylene glycol mono (meth) acrylate, allylamine or its hydrohalide, 2-trimethylaminoethyl (meth) acrylate or its hydrogen halide A carboxyl group, a sulfonic acid group, a phosphoric acid, an amino group or a salt thereof such as an acid salt can be used.

  Regarding the above surface modification method, specifically, Noboru Suzuki, Nobuko Yuzawa, Satoshi Endo, Hiroshi Utsuki “Color Material” 57, 429 (1984), Hiroshi Yoshioka, Masayuki Ikeno “Surface” 21, 33 ( 1983), Tsuji Hiroshi `` Surface '', 16 pages, 525 pages (1978), K. Tanaka, et al., Bull. Chem. Soc. Jpn., 53 pages, 1242 pages (1980), ML Hair, W. Hertl. J. Phys. Chem. 77, 1965 (1973), Ya. Davydov et Al., Chromatographia, 14, 13 (1981), K. Unger et al., Colloid Polym. Sci, 252 317 (1974), R. Burwell, O. Lea1, J. Chem. Soc. Chem. Commun., 342 (1974), W. Stoeber, Kolloid-Z 149, 39 (1956), K. Yoshinaga , et. al., Polym. Adv. Technol, Vol. 91 (1992), N. Tsubokawa, et al., Polym. J. 21, Vol. 475 (1989), Franz. Pat. 1368765, DAS 1163784, etc. Can be synthesized according to the methods described in the above review and references, patents and the like cited therein.

[Crosslinking between surface modified particles]
Examples of the crosslinking agent that can be used to reinforce the surface modification layer or to enhance the binding property between the surface-modified particles include hydrolyzable polymerizable compounds represented by the following general formula (II). . At this time, the metal complex of the acetylacetone derivative is used as a catalyst in order to promote hydrolysis polymerization and effectively cure the gel layer. The addition amount of the metal complex is at least a concentration at which the catalytic action of the hydrolysis polymerization reaction appears, but the preferred addition amount is 10 ⁻⁴ to 10 ⁻¹ mol / mol, more preferably 10 ⁻³ to 10 ⁻ per siloxane unit. ¹ mol / mol.

In the general formula (III), R ⁵ and R ⁶ may be the same or different and each represents an alkyl group or an aryl group, X represents Si, Al, Ti or Zr, and m represents 0-2. Represents an integer. When R ⁵ or R ⁶ represents an alkyl group, the number of carbon atoms is preferably 1 to 4. Further, the alkyl group or aryl group may have a substituent. This compound is a low molecular compound and preferably has a molecular weight of 1000 or less.

  As what contains aluminum in a hydrolyzable polymerizable compound, a trimethoxy aluminate, a triethoxy aluminate, a tripropoxy aluminate, a tetraethoxy aluminate etc. can be mentioned, for example. Examples of those containing titanium include trimethoxy titanate, tetramethoxy titanate, triethoxy titanate, tetraethoxy titanate, tetrapropoxy titanate, chlorotrimethoxy titanate, chlorotriethoxy titanate, ethyl trimethoxy titanate, methyl triethoxy titanate, ethyl Examples include triethoxy titanate, diethyl diethoxy titanate, phenyl trimethoxy titanate, and phenyl triethoxy titanate. As what contains a zirconium, the zirconate corresponding to the thing containing the said titanium can be mentioned, for example.

  Examples of the silicon containing hydrolyzable polymerizable compound include trimethoxysilane, triethoxysilane, tripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, Propyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, γ-chloropropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltri Ethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diphenyldimethoxysilane Emissions, may be mentioned diphenyl diethoxy silane.

  Among these, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxy are particularly preferable. Examples include silane, siphenyldimethoxysilane, diphenyldiethoxysilane, and the like.

  The surface-modified particles used in the present invention and the compound represented by the general formula (III) may be used alone or in combination of two or more. In addition, the compound of the general formula (III) may be partially dehydrated and condensed after hydrolysis. In order to enhance the storage stability of the image forming material in a solution state before being applied to the substrate, an active metal of an inorganic polymer in which the hydrolysis polymerizable organometallic compound represented by the general formula (III) is partially hydrolyzed It is effective to protect a hydroxyl group, for example, a silanol group (Si-OH). Protection of the silanol group can be achieved by etherifying (Si-OR) the silanol group with a higher alcohol such as t-butanol, i-propyl alcohol, where R is simply any group. It does not represent a specific group). Specifically, it can be carried out by adding the higher alcohol to an inorganic phase in which silica fine particles are dispersed. At this time, due to the properties of the inorganic phase, for example, the storage stability can be further improved by dehydrating the inorganic phase by means such as heating the inorganic phase to distill off the desorbed water.

  In the present invention, the composite of the surface-modified particles and the crosslinking agent obtained by crosslinking the surface-modified particles with the crosslinking agent represented by the general formula (III) is 2 to 90 mass with respect to the total solid content of the hydrophilic layer of the lithographic printing plate substrate. %, Preferably 5 to 80% by mass, particularly preferably 10 to 50% by mass, in the hydrophilic layer. When the content of the particles is less than 2% by mass, the water retention becomes insufficient and soiling tends to occur. If it exceeds 50% by mass, the strength of the hydrophilic layer is lowered, the printing durability is lowered, and the adhesion between the support and the hydrophilic layer is lowered.

  The organic-inorganic composite comprising the surface-modified particle-crosslinking agent in the present invention is prepared by hydrolysis polymerization, and any known method may be used, for example, “Science of Sol-Gel Method” (Agne Jofu Co., Ltd.). ) Can be used. As a preferred example, an acid (phosphoric acid, hydrochloric acid, sulfuric acid, acetic acid) is used as a catalyst in an alcohol solution, preferably a methanol or ethanol solution in which the surface-modified particles of the present invention and a crosslinking agent (for example, a compound of the general formula (III)) are dispersed. Particularly preferably, phosphoric acid, hydrochloric acid or alkali (aqueous ammonia) is added to prepare a starting solution. Next, it is stirred at 0 to 100 ° C., preferably 10 to 80 ° C. under reflux for 5 minutes to 6 hours, particularly preferably 10 minutes to 2 hours, hydrolyzed and polymerized by surface modification particles-crosslinking agent. An inorganic composite can be formed.

[catalyst]
In order to accelerate the hydrolysis and polycondensation reaction of the silane compound represented by the general formula (III) and the metal compound used in combination, an inorganic acid such as nitric acid and hydrochloric acid or a base such as ammonia can be used as a catalyst. In the present invention, a metal complex catalyst is used. Preferred metal complex catalysts are selected from metal elements selected from groups 2A, 3B, 4A and 5A of the periodic table and β-diketones, ketoesters, hydroxycarboxylic acids or esters thereof, amino alcohols, and enolic active hydrogen compounds. A metal complex composed of an oxo- or hydroxy-oxygen-containing compound.

  Among constituent metal elements, 2A group elements such as Mg, Ca, St and Ba, 3B group elements such as Al and Ga, 4A group elements such as Ti and Zr, and 5A group elements such as V, Nb and Ta are preferable. , Each forming a complex with excellent effects. Among them, complexes obtained from Zr, Al and Ti are excellent.

  In the present invention, an oxo- or hydroxy-oxygen-containing compound constituting the ligand of the metal complex is a β-diketone such as acetylacetone (2,4-pentanedione) or 2,4-heptanedione, methyl acetoacetate, Ketoesters such as ethyl acetoacetate and butylacetoacetate, hydroxycarboxylic acids and esters thereof such as lactic acid, methyl lactate, salicylic acid, ethyl salicylate, phenyl salicylate, malic acid, tartaric acid, methyl tartrate, 4-hydroxy-4-methyl-2 -Keto alcohols such as pentanone, 4-hydroxy-2-pentanone, 4-hydroxy-4-methyl-2-pentanone, 4-hydroxy-2-heptanone, monoethanolamine, N, N-dimethylethanolamine, N- Methyl-monoethanolamine, diethanolamine , Amino alcohols such as triethanolamine, methylol melamine, methylol urea, methylol acrylamide, enol active compounds such as malonic acid diethyl ester, methyl group, methylene group or carbonyl carbon of acetylacetone (2,4-pentanedione) And compounds having a group.

  A preferred ligand is an acetylacetone derivative, and the acetylacetone derivative in the present invention refers to a compound having a substituent on the methyl group, methylene group or carbonyl carbon of acetylacetone. As the substituents substituted on the methyl group of acetylacetone, all are linear or branched alkyl groups having 1 to 3 carbon atoms, acyl groups, hydroxyalkyl groups, carboxyalkyl groups, alkoxy groups, alkoxyalkyl groups, and acetylacetone As a substituent for the methylene group, a carboxyl group, each of which is a linear or branched carboxyalkyl group and a hydroxyalkyl group having 1 to 3 carbon atoms, and a substituent for the carbonyl carbon of acetylacetone is a carbon number. Is an alkyl group of 1 to 3, and in this case, a hydrogen atom is added to the carbonyl oxygen to form a hydroxyl group.

  Specific examples of preferred acetylacetone derivatives include acetylacetone, ethylcarbonylacetone, propylcarbonylacetone, i-propylcarbonylacetone, diacetylacetone, 1-acetyl-1-propionyl-acetylacetone, hydroxyethylcarbonylacetone, hydroxypropylcarbonylacetone, acetoacetic acid. , Acetopropionic acid, diacetacetic acid, 3,3-diacetpropionic acid, 4,4-diacetbutyric acid, carboxyethylcarbonylacetone, carboxypropylcarbonylacetone, diacetone alcohol. Of these, acetylacetone and diacetylacetone are particularly preferred.

  The complex of the above acetylacetone derivative and the above metal element is a mononuclear complex in which 1 to 4 molecules of the acetylacetone derivative are coordinated per metal element, and the hand capable of coordinating the metal element can coordinate the acetylacetone derivative. When the number of hands is larger than the total number of hands, ligands commonly used for ordinary complexes such as water molecules, halogen ions, nitro groups, and ammonio groups may coordinate.

Examples of preferred metal complexes include tris (acetylacetonato) aluminum complex, di (acetylacetonato) aluminum / aco complex, mono (acetylacetonato) aluminum / chloro complex, di (diacetylacetonato) aluminum complex, (diacetyl) Acetonato) aluminum / aco complex salt, tris (acetylacetonato) barium complex salt, di (acetylacetonato) titanium complex salt, tris (acetylacetonato) titanium complex salt, these are stable in aqueous coating solution and dried The catalytic effect of the sol-gel reaction is excellent, but tris (acetylacetonato) titanium complex (Ti (acac) ₃ ) is most preferable.

  Although the description of the counter salt of the metal complex described above is omitted in this specification, the type of the counter salt is arbitrary as long as it is a water-soluble salt that maintains the neutrality of the charge as the complex compound, such as nitrate, Salt forms such as halogenates, sulfates, phosphates, etc., that ensure stoichiometric neutrality are used.

  In addition to the metal complex catalyst, an acidic catalyst or a basic catalyst may be used in combination. In that case, the acid or basic compound is used as it is or in a state where 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 and polycondensation rates tend to increase. However, when a basic catalyst having a high concentration is used, a precipitate may be generated in the sol solution. Therefore, the concentration of the basic catalyst is preferably 1 N (concentration in aqueous solution) or less.

  The type of acidic catalyst or basic catalyst that may be used in combination is not particularly limited, but acidic catalysts include hydrogen halides such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, hydrogen sulfide, perchloric acid, hydrogen peroxide. Basic catalysts such as carbonic acid, 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, sulfonic acids such as benzenesulfonic acid, etc. Examples thereof include ammoniacal bases such as water, and amines such as ethylamine and aniline.

  The image recording layer produced by the sol-gel method described above is particularly preferable for the lithographic printing plate precursor according to the invention. 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 “Manufacturing Technology”, General Technology Center (published) (1992).

[Polymerization initiator]
A compound that initiates or accelerates the reaction of the polymerizable group can be added to the image recording layer of the present invention. Examples of such compounds include compounds that generate radicals or cations by heat, such as lophine dimers, trihalomethyl compounds, peroxides, azo compounds, diazonium salts such as diazodiphenylamine, and diphenyliodonium salts. Examples thereof include onium salts, acyl phosphines, and imide sulfonates. These compounds can be added in the range of 1% by mass to 20% by mass in the image recording layer. Preferably it is the range of 3 mass%-10 mass%. Within this range, good reaction initiation or acceleration effect can be obtained without impairing printing durability.

  The radical generator refers to a compound that initiates and accelerates polymerization of a compound having a polymerizable unsaturated group by generating radicals by energy of light, heat, or both. As the radical generator according to the present invention, a known thermal polymerization initiator or a compound having a small bond dissociation energy can be selected and used. For example, an onium salt, an s-triazine having a trihalomethyl group Compounds, organic halogen compounds such as oxazole compounds, peroxides, azo polymerization initiators, aryl azide compounds, carbonyl compounds such as benzophenones, acetophenones, thioxanthones, metallocene compounds, hexaarylbiimidazole compounds, organic boron salt compounds And disulfone compounds.

  Specifically, for example, diazonium salts described in SISchlesinger, Photogr. Sci. Eng., 18,387 (1974), TSBal etal, Polymer, 21, 423 (1980), and the like, US Pat. No. 4,069,055 4, 069,056, JP-A-3-140140, etc., ammonium salts, DCNecker etal, Macromolecules, 17, 2468 (1984), CSWen etal, Teh. Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat.Nos. 4,069,055 and 4,069,056, etc., JVCrivello etal, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov.28, p31 (1988), European Patent No. 104,143, U.S. Pat. Nos. 339,049, 410,201, JP-A-2-150848, JP-A-2-296514. JVCrivello et al, Polymer J. 17, 73 (1985), JVCrivello et al, J. Org. Chem., 43, 3055 (1978), WRWatt et al, J. Polymer Sci. , Polymer Chem. Ed., 22, 1789 (1984), JVCrivello et al, Polymer Bull., 14, 279 (1985), JVCrivello et al, Macromolecules, 14 (5), 1141 (1981), JVCrivello et al, J. Polymer Sci., Polymer Chem. Ed., 17, 2877 (1979), European Patent No. 370,693, US Pat. No. 3,902,114, European Patent Nos. 233,567 and 297,443 297,442, U.S. Patent 4,933,377, European Patent 410,201, 339,049, U.S. Patent 4,760,013, 4,734,444, No. 2,833,827, German Patent Nos. 2,904,626, 3,604,580, 3,604,581, etc., JVCrivello et al, Macromolecules, 10 (6 ), 1307 (1977), JVCrivello et al, J. Polymer Sci., Polymer Chem. Ed., 17, 1047 (1979) and the like, CSWen et al, Teh. Proc. Conf. Rad. Curing ASIA, Examples include onium salts such as arsonium salts described in p478 Tokyo, Oct (1988).

  Specific examples of the organic halogen compound include Wakabayashi et al., Bjll. Chem. Soc. Japan, 42, 2924 (1969), US Pat. No. 3,905,815, Japanese Examined Patent Publication No. 46-4605, and Japanese Unexamined Patent Publication No. 48. -36281, 55-32070, 60-239736, 61-169835, 61-169437, 62-58241, 62-212401, 63-70243, 63-298339 No., MPHutt etal, J. Heterocycl. Chem., 7 (No. 3) (1970) and the like, and particularly, an oxazole compound substituted with a trihalomethyl group and an s-triazine compound.

  Examples of the metallocene compounds include various titanocenes described in JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, JP-A-2-4705, and JP-A-5-83588. Examples of the compound and hexaarylbiimidazole compound include various compounds described in JP-B-6-29285, U.S. Pat. Nos. 3,479,185, 4,311,783, 4,622,286, Examples thereof include iron-arene complexes described in JP-A-1-304453 and 1-152109.

  Examples of the organic borate compounds include JP-A-62-143044, JP-A-62-1050242, JP-A-9-188585, JP-A-9-188686, JP-A-9-188710, and Japanese Patent No. 2764769. No. 2000-310808, Japanese Patent Application No. 2000-310808, and organic borate described in Kunz, Martin “Rad Tech. '98. Proceeding April 19-22 Chicago”, JP-A-6-157623, 6- Organoboron sulfonium complex salts or organoboron oxosulfonium complex salts described in JP-A Nos. 175564 and 6-175561, JP-A-6-175554, JP-A-6-175553, etc., JP-A-6-348011 7-128785, 7-140589, 7-3062527, 7-292014, etc. Containing transition metal coordination complexes can be given as specific examples.

  Examples of the disulfone compound include compounds described in JP-A No. 61-166544 and Japanese Patent Application No. 2001-132318.

  In the present invention, particularly preferably used radical generators include onium salts, particularly onium salts represented by the following general formulas (IV) to (VI).

In formula (IV), Ar ¹¹ and Ar ¹² each independently represent an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a group having 12 or less carbon atoms. An aryloxy group is mentioned. Z ¹¹⁻ represents an inorganic anion or an organic anion.

In the formula (V), Ar ²¹ represents an aryl group having 20 or less carbon atoms which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and 12 or less carbon atoms. Examples thereof include an alkylamino group, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, or a diarylamino group having 12 or less carbon atoms. Z ^21- represents a counter ion having the same ^meaning as Z ^11- .

In the formula (VI), R ³¹ , R ³² and R ³³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferable substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or an aryloxy group having 12 or less carbon atoms. Z ^31- represents a counter ion having the same ^meaning as Z ^11- .

In the general formulas (IV) to (VI), Z ¹¹⁻ , Z ²¹⁻ , and Z ³¹⁻ represent an inorganic anion or an organic anion, and examples of the inorganic anion include halogen ions (F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ ), perchlorate ion (ClO ₄ ⁻ ), perbromate ion (BrO ₄ ⁻ ), tetrafluoroborate ion (BF ₄ ⁻ ), SbF ₆ ⁻ , PF ₆ ^{− and the} like as organic anions Is an organic borate anion, sulfonate ion, phosphonate ion, oxyphosphonate ion, carboxylate ion, R ⁴⁰ SO ₂ ⁻ , R ⁴⁰ SO ₂ S ⁻ , R ⁴⁰ SO ₂ N—Y—R ⁴⁰ ion (here R ⁴⁰ represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, Y represents a single bond, —CO—, —SO ₂ —), and the following general formulas: A pentacoordinate silane compound ion represented by the formula (VII) It is below.

In the above, R ⁴⁰ may have a ring structure, and the alkyl group and aryl group may further have a substituent. Specific examples of the substituent that can be introduced here include an alkyl group, an alkoxy group, an alkenyl group, an alkynyl group, an amino group, a cyano group, a hydroxy group, a halogen atom, an amide group, an ester group, a carbonyl group, Carboxy group etc. are mentioned, These may have the above substituent further. Further, two or more substituents may be bonded to each other to form a ring, and the ring structure may be a heterocyclic structure containing a nitrogen atom, a sulfur atom or the like. Among these, from the viewpoint of synthesis suitability, R ⁴⁰ is preferably an aryl group.

  In the pentacoordinate silane compound ion represented by the general formula (VII), A, B, C, D, and E represent monovalent nonmetallic atoms that are independent of each other. In the formula, A, B, C, D, and E each represent a monovalent nonmetallic atom that is independent of one another, preferably each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. , An alkenyl group, an alkynyl group, an alkoxy group, a phenoxy group, an amino group, a vinyl group, an allyl group, a cyano group, or a halogen atom. These groups may further have one or more substituents. Examples of preferable substituents include halogen atoms, linear or branched alkyls having 1 to 8 carbon atoms. Group, aryl group, alkenyl group, carbonyl group, carboxy group, amide group, acetyl group, ether group, thioether group, ester group, amino group, or a combination of two or more thereof. The adjacent nonmetallic atoms among A, B, C, D, and E may be connected to each other to form a ring.

  Among these five-coordinate silane compound ions, preferred are those in which any of A, B, C, D, and E is a halogen atom, an aryl group, or an alkoxy group. A compound ion in which any one or more of A, B, C, D, and E is a fluorine atom is exemplified.

  In the present invention, specific examples of onium salts that can be suitably used include those described in paragraph numbers [0030] to [0033] of JP-A No. 2001-133696.

  The onium salt used in the present invention preferably has a maximum absorption wavelength of 400 nm or less, and more preferably 360 nm or less. By making the absorption wavelength in the ultraviolet region in this way, the lithographic printing original plate can be handled under white light.

  These onium salts can be added to the image forming layer in a proportion of 0.1 to 50%, preferably 0.5 to 30%, particularly preferably 1 to 20%, based on the total solid content of the image recording layer. Within this range, good sensitivity can be obtained without causing non-image area contamination during printing.

  These onium salts may be used alone or in combination of two or more. These onium salts may be contained in the hydrophobized precursor particles. In this case, a water-insoluble onium salt is preferable, and when it is not contained in the hydrophobized precursor particles, a water-soluble onium salt can be used.

[Application]
The hydrophilic layer according to the present invention can be usually produced by dissolving each of the above components in a solvent and coating the solution on a suitable support. The solvent used here is not particularly limited. For example, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1 -Methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, toluene , Water and the like. These solvents are used alone or in combination. The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by mass.

  In the present invention, it is preferable to use a surfactant in the image recording layer in order to improve the coated surface state. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorosurfactants. Surfactant may be used independently and may be used in combination of 2 or more type.

  The nonionic surfactant used for this invention is not specifically limited, A conventionally well-known thing can be used. For example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol Fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, Polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N N- bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid ester, trialkylamine oxide, polyethylene glycol, copolymers of polyethylene glycol and polypropylene glycol.

  The anionic surfactant used in the present invention is not particularly limited, and conventionally known anionic surfactants can be used. For example, fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinate esters, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy poly Oxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, fatty acid alkyl esters Sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alcohols Ruphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene / maleic anhydride Examples thereof include partial saponification products of polymers, partial saponification products of olefin / maleic anhydride copolymers, and naphthalene sulfonate formalin condensates.

  The cationic surfactant used in the present invention is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.

The amphoteric surfactant used in the present invention is not particularly limited, and conventionally known amphoteric surfactants can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric acid esters, and imidazolines.

  Of the above surfactants, the term “polyoxyethylene” can be read as “polyoxyalkylene” such as polyoxymethylene, polyoxypropylene, polyoxybutylene, etc. These surfactants can also be used.

  Examples of the fluorosurfactant used in the present invention include a fluorosurfactant containing a perfluoroalkyl group in the molecule. Examples of such fluorosurfactants include anionic types such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl phosphates; amphoteric types such as perfluoroalkyl betaines; Cation type such as trimethylammonium salt; perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, perfluoroalkyl Nonionic types such as an oligomer containing a group, a hydrophilic group and a lipophilic group, and a urethane containing a perfluoroalkyl group and a lipophilic group. Moreover, the fluorine-type surfactant described in each gazette of Unexamined-Japanese-Patent No. 62-170950, 62-226143, and 60-168144 is also mentioned suitably.

  Two or more surfactants can be used in combination.

  The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 5% by mass with respect to the total solid content of the image recording layer.

In general, the coating amount (solid content) on the support obtained after coating and drying is preferably 0.5 to 5.0 g / m ² . Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

The drying step after application and the post-heating (condition adjustment) step have been described above. Thickness of the hydrophilic layer of the present invention is preferably ^{0.001g / m 2 ~10g / m 2} , more preferably ^{0.01g / m 2 ~8g / m 2} . The image forming layer coating amount (solid content) obtained after coating and drying varies depending on the application, but 0.5 to 5.0 g / m ² is preferable for a general lithographic printing plate precursor. -3.0 g / m < ² > is more preferable. Within this range, the hydrophilic effect of the present invention can be satisfactorily exhibited, and the adhesion to the support is also good, so that sufficient printing durability can be obtained.

[Surface protective layer]
Since the surface of the lithographic printing original plate of the present invention is hydrophilic, it becomes hydrophobic due to the influence of the environmental atmosphere during handling before use, is affected by temperature and humidity, or is mechanically scratched or soiled. It is easy to be affected. Normally, a plate surface is coated with a leveling solution (also called a gum solution) to protect the plate during the plate making process. However, if a protective solution is applied during the production of the original plate, such a protective effect can be obtained immediately after production. And there is an advantage that workability is improved by eliminating the trouble of newly applying the surface conditioning liquid in the plate making process.

  Furthermore, in the present invention, since the exposure is usually performed in the air, the protective layer is formed of a low-molecular compound such as oxygen or a basic substance present in the air that inhibits an image forming reaction caused by exposure in the image recording layer. It is possible to provide a function of preventing the image recording layer from being mixed and preventing an image formation reaction from being hindered by exposure in the air. In this case, the properties desired for the protective layer are low permeability of low-molecular compounds such as oxygen, furthermore, good transparency of light used for exposure, and excellent adhesion with the image recording layer, And it is preferable that it can be easily removed on a printing press. Various studies have been made on protective layers having such characteristics, and are described in detail, for example, in US Pat. No. 3,458,311 and JP-A-55-49729.

  Examples of the material used for the protective layer include water-soluble polymer compounds that are relatively excellent in crystallinity. Specific examples include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid. Among these, when polyvinyl alcohol (PVA) is used as a main component, the best results are obtained for basic characteristics such as oxygen barrier properties and development removability. The polyvinyl alcohol may be partially substituted with an ester, ether or acetal as long as it contains an unsubstituted vinyl alcohol unit for providing the oxygen barrier property and water solubility necessary for the protective layer, and a part of the other You may have a copolymerization component.

  Specific examples of the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a degree of polymerization of 300 to 2400. Specifically, for example, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA- HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA-420, PVA-613, and L-8 are mentioned.

Components of protective layer (selection of PVA, use of additives, etc.), coating amount, etc. take into account fogging, adhesion, scratch resistance, ablation suppression, etc. in addition to oxygen barrier properties and removability on the printing press Are appropriately selected. In general, the higher the hydrolysis rate of PVA (that is, the higher the content of unsubstituted vinyl alcohol units in the protective layer), the higher the film thickness, the higher the oxygen barrier property, which is preferable in terms of sensitivity. . In order to prevent unnecessary polymerization reaction during production and storage, or unnecessary fogging during image exposure, image line weighting, and the like, it is preferable that the oxygen permeability is not excessively high. Accordingly, the oxygen permeability A at 25 ° C. and 1 atm is preferably 0.2 to 20 (cc / m ² · day).

  As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added.

  The thickness of the protective layer is suitably from 0.05 to 4 μm, particularly preferably from 0.1 to 2.5 μm.

[Undercoat layer]
In the planographic printing plate precursor of the invention used in the planographic printing method of the invention, an undercoat layer can be provided between the image recording layer and the support, if necessary. Since the undercoat layer functions as a heat insulating layer, heat generated by exposure with an infrared laser does not diffuse to the support and can be used efficiently, so that there is an advantage that high sensitivity can be achieved. In the present invention, since the image recording layer serves as both an image portion and a non-image portion, the image recording layer preferably has high adhesion to the support. There is an advantage that improvement in adhesion can be achieved.

  When the support is a plastic film, an acrylic, urethane, cellulose, or epoxy adhesive is applied onto the support, Japanese Patent Laid-Open Nos. 6-316183, 8-272088, and 9-179111. And undercoat coating described in JP-A-2001-199175, that is, a homopolymer or copolymer of polyvinyl alcohol or hydroxyalkyl acrylate or methacrylate, hydrolyzed tetraethyl or methyl orthosilicate, and preferably For example, a layer containing fine particles of silicon dioxide and / or titanium dioxide may be provided on the support surface.

  In the case of a metal support, it is preferable to use an organic or inorganic resin. Examples of such organic or inorganic resins include known hydrophobic polymers, hydrophilic polymers, cross-linked hydrophilic polymers, and compounds that perform sol-gel conversion such as aluminum, silicon, titanium, and zirconium having a hydroxyl group or an alkoxy group. Can be widely selected from inorganic polymers and the like. A particularly preferred undercoat layer in the present invention is an undercoat layer containing silica.

The preferred silica in the undercoat layer is anionic silicon dioxide. The colloidal silica preferably has a surface area of at least 100 m ² / g, more preferably at least 300 m ² / g.

  The surface area of colloidal silica is measured by the BET method published by S. Brunauer, P. H. Emmett and E. Teller on pages 309-312 of J. Amer. Chem. Soc. 60 (1938).

  The silica dispersion can also contain other substances such as aluminum salts, stabilizers, bactericides, and the like.

Such types of silica are commercially available under the names KIESELSOL 100, KIESELSOL 300 and KIESELSOL500 (KIESELSOL is a registered trademark of Farbenfabriken Bayer AG, Lefarksen, Germany, the numbers representing the surface area in m ² / g).

  If necessary, a hydrophilic polymer binder can be added to the primer layer containing silica. As such a hydrophilic polymer binder, the above-described substances can be used as a hydrophilic polymer binder that can be used as a hydrophilic binder in the hydrophilic layer.

  The weight ratio of the hydrophilic polymer binder to silica in the undercoat layer is preferably less than 1. The lower limit is not so important but is preferably at least 0.2. The weight ratio of the hydrophilic polymer binder to silica is more preferably 0.25 to 0.5.

The coverage of the undercoat layer is preferably greater than 10 mg / m ^{2 and} preferably less than 5000 mg / m ² . And more preferably ^{50mg / m 2 ~3000mg / m 2} .

  The coating of the above-mentioned undercoat layer composition is preferably carried out from an aqueous colloidal dispersion in the presence of a surfactant if desired.

[Other layers]
A back coat is provided on the back surface of the support as necessary. Such a back coat comprises a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. A coating layer is preferably used. Among these coating layers, silicon alkoxy compounds such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , and Si (OC ₄ H ₉ ) ₄ are available at a low price. The coating layer of the metal oxide obtained therefrom is particularly preferable because of its excellent hydrophilicity.

[Support]
The support used in the present invention is not particularly limited, but is a dimensionally stable plate-like material. For example, paper, plastic (for example, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, etc.) is laminated. Paper, metal plates (eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, Polypropylene, polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which a metal as described above is laminated or deposited. As the support of the present invention, a polyester film or an aluminum plate is preferable.

  A suitable aluminum plate used in the present invention is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of different 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 mass. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and 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 0.8 mm.

  In the present invention, it is preferable that the support surface is roughened as described below.

  In order to provide a rough surface on the surface of the support, various known means can be employed. For example, the surface of the support can be mechanically rubbed by sandblasting or brushing, the surface is shaved to form a recess, and a rough surface can be provided. Concavities and convexities can also be provided by mechanical embossing. Furthermore, a rough surface may be provided by forming convex portions on the surface by gravure printing or the like. A layer containing solid fine particles (matting agent) may be provided with a rough surface on the support surface by means such as coating or printing. The solid fine particles can be contained (internally added) in the polymer film at the stage of producing the polymer film, thereby forming irregularities on the surface of the polymer film. Furthermore, a rough surface can also be formed using solvent treatment, corona discharge treatment, plasma treatment, electron beam irradiation treatment, X-ray irradiation treatment, or the like. You may implement combining the above means. A means for forming a rough surface by sandblasting or resin printing or a means for forming irregularities by adding solid fine particles can be particularly preferably implemented.

  In particular, when an aluminum plate is used as the support, surface treatment such as roughening treatment or anodizing treatment is preferably performed. The surface treatment facilitates ensuring the adhesion between the image recording layer and the support. Prior to roughening the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like 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, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment for dissolving the surface electrochemically), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).

  As a method for the mechanical surface roughening treatment, 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. Also, a transfer method in which the uneven shape is transferred with a roll provided with unevenness in the aluminum rolling step may be used.

  Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and then anodized as desired. Is given.

  As the electrolyte used for the anodizing treatment of 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 conditions for anodizing treatment vary depending on the electrolyte used and cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. d m ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2.

[Plate making method]
Next, a plate making method of this lithographic printing plate precursor will be described. This lithographic printing plate precursor is, for example, subjected to thermal recording directly in an image-like manner with a thermal recording head or the like, or a high intensity flash light such as a solid laser or semiconductor laser that emits infrared light having a wavelength of 760 to 1200 nm, a xenon discharge lamp, Photothermal conversion type exposure such as infrared lamp exposure can also be used.

Image writing may be performed using either a surface exposure method or a scanning method. In the former case, there are an infrared irradiation method and a method in which heat is generated by light / heat conversion by irradiating the original plate with high-intensity short-time light from a xenon discharge lamp. When a surface exposure light source such as an infrared lamp is used, the preferred exposure varies depending on the illuminance, but usually the surface exposure intensity before modulation with a printing image is 0.05 to 10 J / cm ² . The range is preferably 0.1 to 1 J / cm ² . When the support is transparent, exposure can be performed through the support from the back side of the support. As for the exposure time, it is preferable to select the exposure illuminance so that the above-described exposure intensity can be obtained by irradiation of 0.01 to 1 msec, preferably 0.01 to 0.1 msec. When the irradiation time is long, it is necessary to increase the exposure intensity because of the competitive relationship between the generation rate of the thermal energy and the diffusion rate of the generated thermal energy.

In the latter case, a method is used in which a laser light source containing a large amount of infrared components is used to modulate the laser beam with an image and scan the original. Examples of the laser light source include a semiconductor laser, a helium neon laser, a helium cadmium laser, and a YAG laser. Irradiation can be performed with a laser having a laser output of 0.1 to 300 W. When a pulse laser is used, it is preferable to irradiate a laser having a peak output of 1000 W, preferably 2000 W. In this case, the exposure amount is preferably in the range of 0.05 to 10 J / cm ² , and more preferably in the range of 0.05 to 1 J / cm ² before the surface exposure intensity is modulated with the printing image. preferable. When the support is transparent, exposure can be performed through the support from the back side of the support.

  When making a lithographic printing plate, after image exposure, if necessary, it is said to be “gum drawing” in which a surface-conditioning solution containing a plate surface protecting agent (so-called gum solution) is applied to protect the non-image area. Although the process is often performed, the lithographic printing original plate produced by the method of the present invention can be easily made and printed on the machine, so there is no need for a surface-conditioning liquid treatment. Alternatively, the surface conditioning liquid treatment may be performed. The surface-adjusting liquid treatment prevents the hydrophilic surface of the lithographic printing plate from being affected by minute amounts of components in the air and decreases the hydrophilicity, and increases the hydrophilicity of the non-image area. In order to prevent the lithographic printing plate from deteriorating during this period or from when printing is interrupted to when it is restarted, finger oil, ink, etc. may be removed when handling the lithographic printing plate, such as when installing on a printing press. Various purposes such as preventing non-images from adhering and becoming ink-receptive and smearing, and preventing scratches on non-image areas and image areas when handling lithographic printing plates It is done with.

  Preferable specific examples of the water-soluble resin having film-forming properties used in the present invention include, for example, gum arabic, fiber derivatives (for example, carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose, etc.) and modified products thereof, polyvinyl alcohol And derivatives thereof, polyvinylpyrrolidone, polyacrylamide and copolymers thereof, acrylic acid copolymers, vinyl methyl ether / maleic anhydride copolymers, vinyl acetate / maleic anhydride copolymers, styrene / maleic anhydride copolymers , Roasted dextrin, oxygen-decomposed dextrin, enzyme-decomposed etherified dextrin and the like.

  3-25 mass% is suitable for content of the said water-soluble resin in the protective agent in a surface-control liquid, and a preferable range is 10-25 mass%. In the present invention, two or more of the above water-soluble resins may be used in combination.

  In addition, various surfactants may be added to the lithographic printing plate surface protective agent. Examples of the surfactant that can be used include an anionic surfactant and a nonionic surfactant. Examples of anionic surfactants include aliphatic alcohol sulfate esters, liptartaric acid, malic acid, lactic acid, repric acid, and organic sulfonic acid. As mineral acids, nitric acid, sulfuric acid, phosphoric acid, and the like are useful. You may use together at least 1 type (s) or 2 or more types, such as a mineral acid, an organic acid, or an inorganic salt.

  In addition to the above components, lower polyhydric alcohols such as glycerin, ethylene glycol, and triethylene glycol can be used as a wetting agent if necessary. The use amount of these wetting agents is suitably 0.1 to 5.0% by mass in the protective agent, and the preferred range is 0.5 to 3.0% by mass. In addition to the above, a preservative and the like can be added to the lithographic printing plate surface protective agent of the present invention. For example, benzoic acid and its derivatives, phenol, formalin, sodium dehydroacetate and the like can be added in the range of 0.005 to 2.0% by mass. An antifoaming agent can also be added to the plate surface protective agent. A preferred antifoaming agent contains an organosilicone compound, and the amount added is preferably in the range of 0.0001 to 0.1% by mass.

  In the following examples, the dry solid content ratio was determined by weighing about 1 g of the sample solution, weighing the sample after drying for 1 hour at 120 ° C., and calculating the mass ratio. The acid value was determined by weighing a predetermined amount of the sample solution and titrating with a methanol solution of potassium hydroxide having a known concentration. The particle size was measured with a Horiba Seisakusho laser particle size distribution analyzer LA-910.

[Example 1]
(Creation of aluminum support)
An aluminum plate (material 1050) having a thickness of 0.24 mm was grained on the surface using a nylon brush and 400 mesh Pamiston water suspension, and washed thoroughly with water. This plate was immersed in a 15% aqueous sodium hydroxide solution for etching, and then washed with water. Further, it was neutralized with 1% nitric acid, and then subjected to electric field roughening treatment in a 0.7% nitric acid aqueous solution using a square wave alternating waveform current with an anode electricity quantity of 160 coulomb / dm ² . After washing with water, etching was performed by immersing in a 10% aqueous sodium hydroxide solution, followed by washing with water. Next, it was desmutted by immersing it in a 30% aqueous sulfuric acid solution and then washed with water. Furthermore, anodizing treatment was performed using a direct current in a 20% aqueous sulfuric acid solution to obtain an oxide film amount of 2.7 g / m ² . Furthermore, it processed at 30 degreeC for 10 second using 0.5 weight% of sodium silicate aqueous solution, and obtained the aluminum support body.

(Formation of undercoat layer)
A coating solution having the following composition was prepared, and an undercoat layer having a thickness of 0.5 g / m ² was applied on the aluminum substrate to form an undercoat layer.

────────────────────────────────────────
Undercoat layer composition ─────────────────────────────────────────
Methanol silica (Nissan Chemical Co., Ltd. 30wt% methanol dispersion) 4g
Isopropyl alcohol 21.1g
────────────────────────────────────────

(Preparation of microcapsule solution)
As an oil phase component, 7 g of 4-tert-butylstyrene, 2 g of an adduct of trimethylolpropane and tolylene diisocyanate (Bernock D-750 manufactured by Dainippon Ink Co., Ltd.), 4 g of the following infrared absorbing dye (1), pionine 0.1 g of A-41C (Takemoto Yushi Co., Ltd. surfactant) was dissolved in a mixed solvent of 18.4 g of ethyl acetate and 2.4 g of acetonitrile. As an aqueous phase component, 37.5 g of a 4 mass% aqueous solution of PVA205 (Kuraray polyvinyl alcohol) was prepared. The oil phase component and the aqueous phase component were emulsified at 12000 rpm for 10 minutes using a homogenizer. Thereafter, 26 g of purified water was added and stirred at 65 ° C. for 3 hours. The microcapsules thus obtained were diluted with purified water to a solid content concentration of 15% by mass. The average particle size of the obtained microcapsules was 0.4 μm.

  The obtained microcapsule dispersion was centrifuged, the supernatant was removed, and the resulting solid was embedded in an epoxy resin, and a section was prepared with a microtome at room temperature without immobilization, and the TEM-EELS method was used. When measurement was performed in the range from the surface of the microcapsule to the inside with the energy corresponding to the energy loss of the elemental chlorine, it was found that the elemental chlorine was present only in the microcapsule wall. Among the microcapsule dispersion components, the compound containing chlorine atoms is only the infrared absorbing dye (1), and as a result, it was found that the infrared absorbing dye (1) is present only in the microcapsule wall. .

(Synthesis of hydrophilic polymer having a silane coupling group at the end)
A three-necked flask was charged with 25 g of acrylamide, 3.5 g of 3-mercaptopropyltrimethoxysilane, and 51.3 g of dimethylformamide and heated to 65 ° C. under a nitrogen stream, and 2,2′-azobis (2,4-dimethylvalero) Nitrile) (0.25 g) was added to initiate the reaction. After stirring for 6 hours, the mixture was returned to room temperature and poured into 1.5 L of ethyl acetate, and a solid precipitated. Thereafter, filtration was performed, and the product was sufficiently washed with ethyl acetate and dried (yield 21 g). It was confirmed by GPC (polystyrene standard) that the polymer had a mass average molecular weight of 5000.

(Preparation of sol-gel solution)
19.2 g of ethyl alcohol, 0.86 g of acetylacetone, 0.98 g of tetraethyl orthotitanate, 1.04 g of tetramethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) in purified water 8.82 g, silane coupling group at the synthesized terminal A hydrophilic polymer having a pH of 0.34 g was stirred at 60 ° C. for 2 hours and mixed. Thereafter, it was gradually cooled to room temperature to obtain a sol-gel solution.

(Formation of hydrophilic layer)
A water-based coating solution having the following composition is prepared, coated on the support with a bar coater so that the dry film mass is 3.0 g / m ² , and then dried in an oven at 80 ° C. for 10 minutes. And a hydrophilic layer was formed to obtain a lithographic printing plate.

────────────────────────────────────────
Hydrophilic layer coating composition ────────────────────────────────────────
Colloidal silica (manufactured by Nissan Chemical Co., Snowtex C, 20% H ₂ O)
0.69g
4.9 g of the sol-gel solution
Anionic surfactant (Nikko Chemicals, Nikkor OTP-100S 5% aqueous solution) 0.31 g
0.08 g of the following polymerization initiator (1)
15 g% microcapsule aqueous dispersion 5.2 g
Purified water 4.2g
────────────────────────────────────────

(Printing and evaluation)
RYOBI3200MCD is used for the printing machine, 1% by volume aqueous solution of EU-3 (manufactured by Fuji Photo Film Co., Ltd.) is used as the fountain solution, and the ink is printed using GEOS (N) ink made by Dainippon Ink Co., Ltd. did.

  When a printing plate was prepared by exposing the printing original plate, the plate surface energy at which a fine line of 16 microns was reproduced was defined as sensitivity.

  The above results are shown in Table 1.

[Example 2]
(Preparation of microcapsule solution)
As an oil phase component, 7 g of 4-tert-butylstyrene, 3 g of an adduct of trimethylolpropane and tolylene diisocyanate (Bernock D-750 manufactured by Dainippon Ink Co., Ltd.), 3 g of the following infrared absorbing dye (1), pionine 0.1 g of A-41C (Takemoto Yushi Co., Ltd. surfactant) was dissolved in a mixed solvent of 18.4 g of ethyl acetate and 2.4 g of acetonitrile. As an aqueous phase component, 37.5 g of a 4 mass% aqueous solution of PVA205 (Kuraray polyvinyl alcohol) was prepared. The oil phase component and the aqueous phase component were emulsified at 12000 rpm for 10 minutes using a homogenizer. Thereafter, 26 g of purified water was added and stirred at 65 ° C. for 3 hours. The microcapsules thus obtained were diluted with purified water to a solid content concentration of 15% by mass. The average particle size of the obtained microcapsules was 0.5 μm.

  The obtained microcapsule dispersion was taken out in the same manner as in Example 1, and the presence distribution of chlorine element from the surface to the inside of the microcapsule was measured by the TEM-EELS method. Was found to be distributed. Therefore, it was found that the infrared light absorber (1) exists only in the microcapsule wall.

  A lithographic printing plate precursor was prepared and evaluated in the same manner as in Example 1 except that the prepared microcapsule dispersion was used. The results are shown in Table 1.

[Example 3]
(Preparation of microcapsule solution)
A microcapsule dispersion was obtained in the same manner as in Example 1 except that behenyl methacrylate was used instead of 4-tert-butylstyrene as the oil phase component. The average particle size of the obtained microcapsules was 0.4 μm.

  The obtained microcapsule dispersion was taken out in the same manner as in Example 1, and the presence distribution of chlorine element from the microcapsule surface to the inside was measured by the TEM-EELS method. It was found that a large amount of chlorine element was distributed on the surface and not distributed in the core. Therefore, it was found that the infrared light absorber (1) was present only in the microcapsule wall and on the inner surface.

  A lithographic printing plate precursor was prepared and evaluated in the same manner as in Example 1 except that the prepared microcapsule dispersion was used. The results are shown in Table 1.

[Example 4]
(Preparation of microcapsule solution)
A microcapsule dispersion was obtained in the same manner as in Example 1 except that the following liquid crystal compound (1) was used instead of 4-tert-butylstyrene as the oil phase component. The average particle diameter of the obtained microcapsules was 0.6 μm.

  The obtained microcapsule dispersion was taken out in the same manner as in Example 1, and the presence distribution of chlorine element from the microcapsule surface to the inside was measured by the TEM-EELS method. It was found that a large amount of chlorine element was distributed in the core and not in the core. Therefore, it was found that the infrared light absorber (1) was present only in the microcapsule wall and on the internal interface.

  A lithographic printing plate precursor was prepared and evaluated in the same manner as in Example 1 except that the prepared microcapsule dispersion was used. The results are shown in Table 1.

[Comparative Example 1]
(Preparation of microcapsule solution)
As an oil phase component, 7 g of 4-tert-butylstyrene, 2 g of an adduct of trimethylolpropane and tolylene diisocyanate (Bernock D-750 manufactured by Dainippon Ink Co., Ltd.), Pionine A-41C (Takemoto Yushi Co., Ltd.) (Surfactant) 0.1 g was dissolved in ethyl acetate 18.4 g. As an aqueous phase component, 37.5 g of a 4 mass% aqueous solution of PVA205 (Kuraray polyvinyl alcohol) was prepared. The oil phase component and the aqueous phase component were emulsified at 12000 rpm for 10 minutes using a homogenizer. Thereafter, 26 g of purified water was added and stirred at 65 ° C. for 3 hours. The microcapsules thus obtained were diluted with purified water to a solid content concentration of 15% by mass. The average particle diameter of the obtained microcapsules was 0.3 μm.

  Solid content was taken out from the obtained microcapsule dispersion in the same manner as in Example 1, and the presence distribution of chlorine element from the microcapsule surface to the inside was measured by the TEM-EELS method. As a result, no chlorine element was detected.

(Formation of hydrophilic layer)
A water-based coating solution having the following composition is prepared, coated on the support with a bar coater so that the dry film mass is 3.0 g / m ² , and then dried in an oven at 80 ° C. for 10 minutes. And a hydrophilic layer was formed to obtain a lithographic printing plate.

────────────────────────────────────────
Hydrophilic layer coating composition ────────────────────────────────────────
Colloidal silica (Nissan Chemical Co., Ltd., Snowtex C, 20% H ₂ O) 0.69 g
4.9 g of the sol-gel solution
Anionic surfactant (Nikko Chemicals, Nikkor OTP-100S 5% aqueous solution) 0.31 g
0.08 g of the above polymerization initiator (1)
15 g% microcapsule aqueous dispersion 5.2 g
Infrared light absorbent (2) 0.33 g
Purified water 3.2g
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  A lithographic printing original plate was prepared and evaluated in the same manner as in Example 1 except that the hydrophilic layer coating solution having the above composition was used. The results are shown in Table 1.

[Comparative Example 2]
(Preparation of microcapsule solution)
As an oil phase component, 7 g of 4-tert-butylstyrene, 2 g of an adduct of trimethylolpropane and tolylene diisocyanate (Bernock D-750 manufactured by Dainippon Ink Co., Ltd.), 1 g of the following infrared absorbing dye (1), pionine 0.1 g of A-41C (Takemoto Yushi Co., Ltd. surfactant) was dissolved in a mixed solvent of 18.4 g of ethyl acetate and 2.4 g of acetonitrile. As an aqueous phase component, 37.5 g of a 4 mass% aqueous solution of PVA205 (Kuraray polyvinyl alcohol) was prepared. The oil phase component and the aqueous phase component were emulsified at 12000 rpm for 10 minutes using a homogenizer. Thereafter, 26 g of purified water was added and stirred at 65 ° C. for 3 hours. The microcapsules thus obtained were diluted with purified water to a solid content concentration of 15% by mass. The average particle size of the obtained microcapsules was 0.2 μm.

  The obtained microcapsule dispersion was taken out in the same manner as in Example 1, and the presence distribution of chlorine element from the surface of the microcapsule to the inside was measured by the TEM-EELS method. Was found to be distributed. Therefore, it was found that the infrared light absorber (1) exists only in the microcapsule wall.

  A lithographic printing original plate was prepared and evaluated in the same manner as in Comparative Example 1 except that the prepared microcapsule dispersion was used. The results are shown in Table 1.

[Comparative Example 3]
(Preparation of microcapsule solution)
Dispersion of microcapsules in the same manner as in Example 1 except that tri (acryloyloxyethyl) isocyanurate (manufactured by Toa Gosei Co., Ltd., M-315) was used instead of 4-tert-butylstyrene as the oil phase component. A liquid was obtained. The average particle size of the obtained microcapsules was 0.2 μm.

  The obtained microcapsule dispersion was taken out in the same manner as in Example 1, and the presence distribution of chlorine element from the microcapsule surface to the inside was measured by the TEM-EELS method. In both cases, the distribution of chlorine element was observed, and it was found that a large amount of chlorine element was distributed especially in the core. Therefore, it was found that in this microcapsule, a large amount of infrared light absorber was distributed in the core portion.

  A lithographic printing original plate was prepared and evaluated in the same manner as in Comparative Example 1 except that the prepared microcapsule dispersion was used. The results are shown in Table 1.

a: The photothermal conversion agent is distributed only in the shell portion and on the shell / core interface b: The photothermal conversion agent is contained outside the particles (in the hydrophilic layer) c: The photothermal conversion agent is in the shell portion and the core Included in the core and more in the core than in the shell
* 1) The photothermal conversion agent is contained in the hydrophilic matrix in a proportion equal to 2 parts by mass with respect to 1 part by mass of the shell part of the microcapsule in the hydrophilic layer.

Claims (8)

  A lithographic printing original plate having a hydrophilic layer containing particles and a support, wherein the particles have a shell portion made of a polymer and a core portion made of a hydrophobic compound, wherein the shell portion further contains a photothermal conversion agent as a polymer 1 A lithographic printing plate precursor comprising 0.9 to 3 parts by mass with respect to parts by mass.   The particles contain a hydrophobic compound and a photothermal conversion agent, the difference in I / O value between the hydrophobic compound and the photothermal conversion agent is 0.2 or more, and the I / O value of the hydrophobic compound is a photothermal conversion agent The lithographic printing plate precursor according to claim 1, wherein the lithographic printing plate precursor is lower than the I / O value of   The lithographic printing plate precursor according to claim 1, wherein the particles are microcapsules.   The lithographic printing plate precursor according to claim 1, wherein the hydrophilic layer further contains a water-insoluble hydrophilic resin outside the particles.   The lithographic printing plate precursor according to claim 1, wherein the hydrophobic compound has a polymerizable group, and the hydrophilic layer further contains a polymerization initiator.   The lithographic printing plate precursor according to claim 1, wherein the photothermal conversion agent is an infrared absorber.   It has a hydrophilic layer containing particles and a support, and the particles have a shell part made of a polymer and a core part made of a hydrophobic compound. A lithographic printing plate precursor in the range of 9 to 3 parts by mass is exposed to an image, and the exposed hydrophilic layer surface is converted to hydrophobic, and the surface is composed of an unexposed hydrophilic layer surface. A lithographic printing method comprising: a step of making a lithographic printing plate having a hydrophilic region; and a step of printing with the lithographic printing plate that has been made.   The lithographic printing method according to claim 7, wherein the photothermal conversion agent is an infrared absorber, and the lithographic printing original plate is exposed in an image form by scanning exposure with an infrared laser.