JP2003112483A - Image forming method, method for making lithographic printing plate and lithographic printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a lithographic printing plate with plate wearability. SOLUTION: The lithographic printing plate making method consists of a process for cross-linking a hydrophobic polymer by imagingly heating an original lithographic printing plate having an image forming layer including the hydrophobic polymer with an o-quinodimethane structure or its precursor structure provided on a hydrophilic support and a process for removing the image forming layer belonging to a non-heating portion.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method of forming an image composed of crosslinked polymers. In particular, the present invention relates to a method for making a lithographic printing plate capable of recording an image by scanning exposure of laser light based on a digital signal.

[0002]

2. Description of the Related Art Generally, a lithographic printing plate comprises an oleophilic image portion that receives ink during the printing process and a hydrophilic non-image portion that receives fountain solution. A conventional lithographic printing plate is prepared by mask-exposing a PS plate having a lipophilic photosensitive resin layer on a hydrophilic support through a lith film, and then dissolving and removing the non-image area with a developing solution. It was normal to do. In recent years, image information is electronically processed as digital information using a computer, accumulated, and output. Therefore, in the image forming process according to the digital image information, the image formation is directly performed on the lithographic printing plate precursor without the intermediary of the lith film by the scanning exposure using the highly directional actinic radiation such as the laser beam. Is desirable. In this way, the technology of making a printing plate from digital image information without using a lith film is a computer-to-computer method.
It is called a plate (CTP). When the conventional plate-making method for a printing plate using a PS plate is attempted to be carried out by computer-to-plate (CTP) technology, there is a problem that the wavelength region of laser light and the photosensitive wavelength region of the photosensitive resin do not match.

In addition, in the conventional PS plate, a step (developing process) of dissolving and removing the non-image portion after exposure is indispensable.
Further, a post-treatment step of washing the developed printing plate with water, treating with a rinse solution containing a surfactant, or treating with a desensitizing solution containing gum arabic or a starch derivative was also required. The fact that these additional wet treatments are indispensable has been a major study subject of conventional PS plates. Even if the first half (image forming process) of the plate making process is simplified by the digital process, the effect by the simplification is insufficient in the wet process in which the latter half (developing process) is complicated. Particularly in recent years, consideration of the global environment has become a major concern of the entire industry. In consideration of the environment, it is desirable that the wet post-treatment be simplified, changed to the dry treatment, or even eliminated.

As one of the methods for eliminating the processing step, an exposed printing plate precursor is mounted on a cylinder of a printing machine, and dampening water and ink are supplied while the cylinder is rotated to supply the printing plate precursor. There is a method called on-press development that removes non-image areas. That is, after exposing the printing plate precursor,
This is a method in which it is installed in the printing machine as it is and the processing is completed during the normal printing process. Such a lithographic printing plate precursor suitable for on-press development has a photosensitive layer soluble in dampening water or an ink solvent, and is suitable for development on a printing machine placed in a bright room. It is necessary to have good light room handling.
In the conventional PS version, satisfying such requirements is
It was virtually impossible.

Japanese Patent No. 2938397 discloses a lithographic printing original plate having a hydrophilic support on which a photosensitive layer, in which fine particles of a thermoplastic hydrophobic polymer are dispersed in a hydrophilic binder polymer, is provided. According to the description of the publication, in plate-making, infrared laser exposure is carried out to form an image by coalescing (fusing) the thermoplastic hydrophobic polymer fine particles by heat, and then the plate is mounted on the plate cylinder of the printing machine and wetted. On-press development is possible by supplying water and / or ink. This lithographic printing plate precursor has a light-sensitive region in the infrared region, and thus has handleability in a bright room. However, in the image forming method in which the polymer particles as described above are fused and united by the heat generated by exposure, if the on-press development is facilitated, it is difficult to obtain the printing durability, and if the printing durability is increased, the on-press development is performed. However, there is a problem that it is difficult to achieve both of them, such as the deterioration of the printability and the difficulty of smearing during printing.

[0006]

An object of the present invention is to form a replica image composed of a crosslinked polymer.
Another object of the present invention is to produce a lithographic printing plate having printing durability. Further, it is an object of the present invention to provide a lithographic printing original plate having high sensitivity and high resolution.

[0007]

The present invention includes the following image forming method (1), lithographic printing plate making method of the following (2) to (9), lithographic printing method of the following (10), and (11) ) ~
The image forming material (14), the lithographic printing original plate (15) to (24) below and the hydrophobic polymer fine particles (25) below are provided. (1) A step of image-wise heating an image-forming material in which an image-forming layer containing a polymer having an o-quinodimethane structure or a precursor structure thereof is provided on a support to cross-link the polymer, and heating An image forming method, which comprises a step of forming a replica image made of a crosslinked polymer by removing an image forming layer of a portion which is not formed.

(2) A lithographic printing plate precursor on which an image forming layer containing a hydrophobic polymer having an o-quinodimethane structure or its precursor structure is provided on a hydrophilic support is imagewise heated to be hydrophobic. A method of making a lithographic printing plate comprising a step of crosslinking a polymer and a step of removing an image forming layer in a portion which is not heated. (3) The hydrophobic polymer has a benzocyclobutene structure.
-The plate-making method according to (2), which has a precursor structure of a quinodimethane structure. (4) The plate-making method according to (2), wherein the hydrophobic polymer further has an acidic group, and the image-forming layer in the unheated portion is removed by treating with an alkaline eluent. (5) The plate-making method according to (2), wherein the hydrophobic polymer has an o-quinodimethane structure or a precursor structure thereof in the side chain.

(6) The plate-making method according to (2), wherein the image-forming layer contains fine particles of a hydrophobic polymer and a hydrophilic polymer, and the image-forming layer in the unheated portion is removed. (7) The plate making method according to (2), wherein the image forming layer further contains a compound having a plurality of dienophile structures. (8) The plate making method according to (6), wherein the compound having a plurality of dienophile structures is a polymer. (9) The plate making method according to (2), wherein the image forming layer further contains a photothermal conversion agent, and the planographic printing plate precursor is imagewise heated by scanning with a laser beam.

(10) An image of a lithographic printing plate precursor is provided on which an image forming layer containing fine particles of a hydrophobic polymer having an o-quinodimethane structure or a precursor structure thereof and a hydrophilic polymer is provided on a hydrophilic support. Step of heating in a circular shape to crosslink the hydrophobic polymer, mounting the lithographic printing plate precursor to the printing machine and operating the printing machine, and removing the image forming layer in the unheated area by dampening water, ink, or rubbing A lithographic printing method comprising the steps of making a lithographic printing plate by this, and further supplying dampening water and an oil-based ink to perform printing with the lithographic printing plate thus made.

(11) An image forming material in which an image forming layer containing a polymer having an o-quinodimethane structure or a precursor structure thereof is provided on a support. (12) The image forming material according to (11), wherein the polymer has a benzocyclobutene structure as a precursor structure of an o-quinodimethane structure. (13) The image forming material according to (12), wherein the polymer has a side chain containing a benzocyclobutene structure. (14) The image forming material according to (13), wherein a side chain containing a benzocyclobutene structure is bonded to a hydrocarbon main chain.

(15) A lithographic printing original plate provided with an image forming layer containing a polymer having an o-quinodimethane structure or its precursor structure on a hydrophilic support. (16) The image forming layer further contains a photothermal conversion agent (1
The lithographic printing original plate as described in 5). (17) The lithographic printing original plate as described in (15), wherein the polymer has a benzocyclobutene structure as a precursor structure of an o-quinodimethane structure. (18) The lithographic printing original plate as described in (17), wherein the polymer has a side chain containing a benzocyclobutene structure. (19) The lithographic printing original plate as described in (18), wherein a side chain containing a benzocyclobutene structure is bonded to a hydrocarbon main chain.

(20) A lithographic printing original plate provided with an image forming layer containing fine particles of a hydrophobic polymer having an o-quinodimethane structure or a precursor structure thereof and a hydrophilic polymer on a hydrophilic support. (21) The image forming layer further contains a photothermal conversion agent (2
The lithographic printing original plate described in 0). (22) The lithographic printing original plate as described in (21), wherein the polymer has a benzocyclobutene structure as a precursor structure of an o-quinodimethane structure. (23) The lithographic printing plate precursor as described in (22), wherein the polymer has a side chain containing a benzocyclobutene structure. (24) The lithographic printing original plate as described in (23), wherein a side chain containing a benzocyclobutene structure is bonded to a hydrocarbon main chain. (25) Hydrophobic polymer fine particles made of a hydrophobic polymer having a side chain containing a benzocyclobutene structure bonded to a hydrocarbon main chain.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION [Polymer having o-quinodimethane structure or precursor structure thereof] The polymer has an o-quinodimethane structure or precursor structure thereof. The o-quinodimethane structure can be defined by the following formula.

[0015]

[Chemical 1]

In the above formula, R is a hydrogen atom or a monovalent group. At least one R is attached to the polymer backbone. Since the o-quinodimethane structure is highly reactive,
It is preferred to introduce the precursor structure into the polymer.
The precursor structure is a structure capable of forming an o-quinodimethane structure by some reaction. When making a planographic printing plate,
Since the hydrophobic polymer is crosslinked by heating, a precursor structure capable of forming an o-quinodimethane structure by heating is preferable. The benzocyclobutene structure is a particularly preferred precursor structure of the o-quinodimethane structure. As shown below, the benzocyclobutene structure can form an o-quinodimethane structure by heating.

[0017]

[Chemical 2]

The o-quinodimethane structures can be linked together by a dimerization reaction. Therefore, a polymer having an o-quinodimethane structure or its precursor structure is
It can be crosslinked by a dimerization reaction of the o-quinodimethane structure. In the dimerization reaction, as shown below, two o-quinodimethane structures generate a cyclooctadiene ring (b1) or a spiro bond (b2) via the intermediate (a). In addition, it is increased in quantity via the intermediate (a) (b
3) Sometimes.

[0019]

[Chemical 3]

The o-quinodimethane structures can also be linked together by the Diels-Alder reaction. That is, o
A hydrophobic polymer having a -quinodimethane structure or its precursor structure can be crosslinked by a Diels-Alder reaction between an o-quinodimethane structure and a compound having a plurality of dienophile structures. In the Diels-Alder reaction, as shown below, two o-quinodimethane structures react with a compound (c) having a plurality of dienophile structures to form two cyclohexene rings and bond (d) to form a bond. To do. The compound (c) in the following formula is a compound having two dienophile structures, and L is a divalent linking group.

[0021]

[Chemical 4]

The polymer is preferably hydrophobic.
The main chain of the hydrophobic polymer is preferably selected from hydrocarbon (polyolefin), polyester, polyamide, polyimide, polyurea, polyurethane, polyether and combinations thereof. A hydrocarbon backbone is especially preferred.

The main chain of the hydrophobic polymer may have a substituent other than the side chain containing the o-quinodimethane structure or its precursor. Examples of the substituents include a halogen atom (F, Cl, Br, I), hydroxyl, mercapto,
Carboxyl, sulfo, sulfate ester group, phosphono, phosphate ester group, cyano, aliphatic group, aromatic group, heterocyclic group, -OR, -SR, -CO-R, -NH-R,-.
N (-R) ₂ , -N ⁺ (-R) ₃ , -CO-OR,-
O-CO-R, -CO-NH-R, -NH-CO-R and -P (= O) (-O-R) ₂ are included. R above
Are respectively an aliphatic group, an aromatic group or a heterocyclic group. The carboxyl, sulfo, sulfate ester group, phosphono and phosphate ester group may have hydrogen atoms dissociated or may be in a salt state. A plurality of substituents on the main chain may combine to form an aliphatic ring or a heterocycle.
The formed ring may have a bond of a main chain and a spiro bond. The ring formed may have a substituent. Examples of the substituent include oxo (═O) in addition to the above-mentioned main chain substituent.

In the present specification, the aliphatic group means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group or a substituted alkynyl group.
The alkyl group may have a cyclic structure or a branched structure. Another aliphatic ring, aromatic ring or heterocyclic ring may be condensed with the cyclic alkyl group. The alkyl group has preferably 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, further preferably 1 to 20 carbon atoms, further preferably 1 to 15 carbon atoms. 12 is the most preferable. The alkyl part of the substituted alkyl group is the same as the alkyl group. Examples of the substituent of the substituted alkyl group include a halogen atom (F, C
l, Br, I), amino, hydroxyl, mercapto,
Carboxyl, sulfo, sulfate group, phosphono, phosphate group, cyano, aromatic group, heterocyclic group, -O-
R, -SR, -CO-R, -NH-R, -N (-R)
₂ , -N ⁺ (-R) ₃ , -CO-OR, -O-CO-
R, -CO-NH-R, -NH-CO-R and -P
(= O) (-OR) ₂ is included. The R's are each an aliphatic group, an aromatic group or a heterocyclic group. The carboxyl, sulfo, sulfate ester group, phosphono and phosphate ester group may have hydrogen atoms dissociated or may be in a salt state.

The alkenyl group may have a cyclic structure or a branched structure. Another aliphatic ring, aromatic ring or heterocycle may be condensed with the cyclic alkenyl group. The number of carbon atoms of the alkenyl group is preferably 2 to 40, more preferably 2 to 30 and 2 to 2
0 is more preferable, 2 to 15 is still more preferable, 2 to 12 is most preferable. The alkenyl part of the substituted alkenyl group is the same as the alkenyl group. The substituent of the substituted alkenyl group is the same as the substituent of the substituted alkyl group. The alkynyl group is
It may have a cyclic structure or a branched structure. Another aliphatic ring, aromatic ring or heterocyclic ring may be condensed with the cyclic alkynyl group. The number of carbon atoms in the alkynyl group is preferably 2 to 40, more preferably 2 to 30, still more preferably 2 to 20 and even more preferably 2 to 15 12 is the most preferable. The alkynyl portion of the substituted alkynyl group is the same as the alkynyl group. The substituent of the substituted alkenyl group is the same as the substituent of the substituted alkyl group.

In the present specification, the aromatic group means an aryl group or a substituted aryl group. The aryl group is preferably phenyl or naphthyl, more preferably phenyl. An aliphatic ring or a heterocyclic ring may be condensed with the aryl group. The aryl part of the substituted aryl group is the same as the aryl group. Examples of the substituent of the substituted aryl group include a halogen atom (F, Cl, B
r, I), amino, hydroxyl, mercapto, carboxyl, sulfo, sulfate group, phosphono, phosphate group, cyano, aliphatic group, aromatic group, heterocyclic group,-
OR, -SR, -CO-R, -NH-R, -N (-
R) ₂ , -N ⁺ (-R) ₃ , -CO-OR, -OC.
OR, -CO-NH-R, -NH-CO-R and-
P (= O) (-OR) ₂ is included. The R's are each an aliphatic group, an aromatic group or a heterocyclic group. The carboxyl, sulfo, sulfate ester group, phosphono and phosphate ester group may have hydrogen atoms dissociated or may be in a salt state. In the present specification, the heterocyclic group means an unsubstituted heterocyclic group or a substituted heterocyclic group. The heterocyclic group may be condensed with another heterocyclic ring, an aliphatic ring or an aromatic ring. The heterocycle is preferably a 3-membered to 7-membered ring. The hetero atom of the hetero ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. Examples of the substituent of the substituted heterocycle include, in addition to the examples of the substituent of the substituted aryl group,
Oxo (= O) is included.

The hydrophobic polymer preferably has a repeating unit containing a benzocyclobutene structure represented by the following formula (I) in the side chain.

[0028]

[Chemical 5]

In the formula (I), R ¹ is a hydrogen atom, a halogen atom (F, Cl, Br, I) or an alkyl group having 1 to 10 carbon atoms. R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and is preferably a hydrogen atom or methyl. Is most preferred.

In the formula (I), each L ¹ independently represents a single bond or a divalent linking group. The divalent linking group is -CO-, -O-, -S-, -NH-, -SO.
It is preferably selected from _2- , alkylene groups, arylene groups and combinations thereof. The alkylene group preferably has 1 to 12 carbon atoms, and 1
Is more preferably 8 to 8, and most preferably 1 to 6. The alkylene group may have a cyclic structure or a branched structure. The arylene group is preferably phenylene or naphthylene, more preferably phenylene, and most preferably p-phenylene. The arylene group may have a substituent. The substituent of the arylene group is the same as the above-described substituent of the substituted aryl group. An example of L ¹ is shown below. The left side is attached to the main chain and the right side is attached to the benzocyclobutene ring. AL is an alkylene group.

[0031] L-0: Single bond L-1: -O- L-2: -CO-O- L-3: -CO-O-AL-O- L-4: -CO-NH- L-5: -CO-NH-AL-O- L-6: -CO-NH-AL-NH-

In the formula (I), R²Is benzocyclo
A butene ring substituent, n is 0, 1, 2, 3, 4 or
Or 5. Examples of substituents on the benzocyclobutene ring
Is a halogen atom (F, Cl, Br, I), amino,
Droxyl, mercapto, carboxyl, sulfo, sulfuric acid
Ester group, phosphono, phosphate group, cyano, fat
Aliphatic group, aromatic group, heterocyclic group, -OR, -SR,-
CO-R, -NH-R, -N (-R)₂, -N⁺(-
R) ₃, -CO-OR, -O-CO-R, -CO-N
HR, -NH-CO-R and -P (= O) (-O-
R)₂Is included. R is an aliphatic group or
It is an aromatic group or a heterocyclic group. Carboxyl, sulfo,
Sulfate group, phosphono and phosphate group are
Whether the hydrogen atom is dissociated or it is in a salt state
Yes. Examples of the repeating unit represented by the formula (I) are shown below.
You

[0033]

[Chemical 6]

[0034]

[Chemical 7]

[0035]

[Chemical 8]

[0036]

[Chemical 9]

[0037]

[Chemical 10]

[0038]

[Chemical 11]

[0039]

[Chemical 12]

A homopolymer consisting only of the repeating unit represented by the formula (I) can be used as the hydrophobic polymer. Further, a copolymer containing two or more kinds of repeating units represented by the formula (I) can also be used as the hydrophobic polymer. Furthermore, a copolymer composed of the repeating unit represented by the formula (I) and another repeating unit can be used as the hydrophobic polymer. Examples of other repeating units are shown below.

[0041]

[Chemical 13]

[0042]

[Chemical 14]

[0043]

[Chemical 15]

[0044]

[Chemical 16]

[0045]

[Chemical 17]

[0046]

[Chemical 18]

[0047]

[Chemical 19]

When the image forming layer in the unheated portion is removed by treating with an alkaline eluent, the hydrophobic polymer preferably has an acidic group. The acidic group is preferably introduced as a copolymer of a hydrophobic polymer into a repeating unit containing no o-quinodimethane structure or its precursor. As the acidic group, carboxyl (in the above example, II-5, II-6, II-11, II-1
2, II-15, II-16, II-21, II-22) or carboxylic acid anhydrides (II-3, II-4, II in the above example).
-9, II-10, II-23, II-24, II-25, II-
26) is preferred.

When a repeating unit containing an o-quinodimethane structure or its precursor and a repeating unit not containing it are combined to form a copolymer, a repeating unit containing an o-quinodimethane structure or its precursor / o-quinodimethane structure or its The molar ratio of the repeating unit containing no precursor is preferably 5/95 to 99/1, more preferably 10/90 to 98/2, and more preferably 20/80 to 97/3. It is more preferable that it is, 40/60 to 96/4 is still more preferable, and 60/40 to 95/5 is most preferable. Below, the example of the copolymer which consists of the repeating unit which does not contain o-quinodimethane structure or its precursor and the repeating unit which does not contain o-quinodimethane structure or its precursor is shown. The numbers in parentheses correspond to the exemplified numbers with the above repeating unit. The ratio of repeating units is mol%
Is.

CP1: − (I-1) ₇₀ − − (II-1) ₃₀ − CP2: − (I-1) ₈₀ − − (II-3) ₂₀ − CP3: − (I-1) ₈₀ − − (II-5) ₂₀ -CP4 :-( I-3) _80- (II-7) ₂₀ -CP5 :-( I-3) _80- (II-9) ₂₀ -CP6 :-( I-3 _{) 60 - - (II-11} ) 40 - CP7: - (I-3) 70 - - (II-5) 30 - CP8: - (I-4) 70 - - (II-14) 30 - CP9: - _{(I-4) 70 - -} (II-16) 30 - CP10: - (I-4) 80 - - (II-5) 20 - CP11: - (I-5) 60 - - (II-17) 40 - CP12: - (I-5 ) 75 - - (II-19) 25 -

The CP13: - (I-5) 70 - - (II-21) 30 - CP14: - (I-5) 60 - - (II-17) 10 - - (II-5) 30 - CP15: - _{(I-5) 60 - -} (II-5) 40 - CP16: - (I-6) 70 - - (II-18) 30 - CP17: - (I-6) 70 - - (II-20) 30 - CP18: - (I-6 ) 80 - - (II-22) 20 - CP19: - (I-6) 60 - - (II-18) 20 - - (II-6) 20 - CP20: - (I −6) ₆₅ − − (II-6) ₃₅ − CP21: − (I-7) ₈₀ − − (II-23) ₂₀ − CP22: − (I-9) ₇₅ − − (II-23) ₂₅ − CP23 _{: - (I-7) 90} - - (II-25) 10 - CP24: - (I-7) 75 - - (II-5) 25 - CP25 :-( I-18) 80 - - (II-5 ) ₂₀ −

The o-quinodimethane structure and its precursor (eg, benzocyclobutene structure) may be present in the polymer backbone. Below, the example of the polymer (repeating unit) which has a benzocyclobutene structure in the main chain is shown.

[0053]

[Chemical 20]

[0054]

[Chemical 21]

[0055]

[Chemical formula 22]

The polymer can be synthesized by a polymerization reaction of a monomer (generally an ethylenically unsaturated monomer) corresponding to the above repeating unit. A radical polymerization reaction, a cationic polymerization reaction, or an anionic polymerization reaction can be adopted as a specific polymerization reaction. The o-quinodimethane structure or its precursor may be introduced after the synthesis of the backbone polymer. When the polymer is used as fine particles, the polymerization is preferably an emulsion polymerization reaction. In the emulsion polymerization reaction, fine particles can be formed simultaneously with the synthesis of the polymer. For the emulsion polymerization reaction, reaction conditions generally used for producing latex may be adopted. In order to form homogeneous fine particles, it is preferable to use a surfactant in the emulsion polymerization reaction. Any of a cationic surfactant, an anionic surfactant, a nonionic surfactant and an amphoteric surfactant can be used. The amount of the surfactant used is preferably 0.01 to 10% by mass of the total amount of the monomers. It is preferable to use a polymerization initiator (chain transfer agent) for the polymerization reaction. The amount of the polymerization initiator used is 0.
It is preferably from 05 to 10% by mass.

The polymer particles preferably have a particle size of 5 to 500 nm, and 10 to 300 nm.
It is even more preferred to have a particle size of The particle size distribution is preferably as uniform as possible. Two or more kinds of polymer particles may be mixed and used. The weight average molecular weight of the polymer is preferably from 500 to 1,000,000, more preferably from 1,000 to 500,000, even more preferably from 2,000 to 200,000, and even from 5,000 to 100,000. Is most preferred. The polymer is preferably contained in the image forming layer in an amount of 5 to 90% by mass, more preferably 30 to 80% by mass. The polymer particles are prepared by dissolving the above-mentioned polymer in an organic solvent (preferably an organic solvent that is immiscible with water), mixing this with an aqueous solution containing a dispersant to emulsify it, and then applying heat to remove the organic solvent. However, it can also be produced by solidifying into fine particles.

Microcapsules containing a polymer can also be used as the polymer particles. Microcapsules are prepared by the known coacervation method (US Pat. No. 2800).
No. 457 and No. 2800458), interfacial polymerization method (British patent 990443, US patent 32871)
No. 54, Japanese Patent Publication Nos. 38-19574, 42
-446, 42-711), polymer precipitation method (U.S. Pat. Nos. 3,418,250, 3,660,030).
4), isocyanate / polyol wall forming method (US Pat. No. 3,796,669), isocyanate wall forming method (US Pat. No. 3,914,511), urea / formaldehyde wall or urea / formaldehyde-resorcinol wall. Forming Method (US Patent 40
01140, 4087376, and 4089802.
Each specification), melamine-formaldehyde wall or hydroxycellulose wall forming method (US Pat. No. 402)
5445), in situ by monomer polymerization
Method (described in Japanese Patent Publication Nos. 36-9163 and 51-9079), spray drying method (UK Patent 930
422, U.S. Pat. No. 3,111,407) or electrolytic dispersion cooling method (UK patent 952807).
No. 967074).

The microcapsule wall has a three-dimensional crosslink and is preferably swollen by a solvent. For that purpose, it is preferable to use polyurea, polyurethane, polyester, polycarbonate, polyamide and a mixture thereof as the wall material of the microcapsule. Polyurea and polyurethane are particularly preferred. The above-mentioned hydrophobic polymer may be used for the microcapsule wall.

The average particle size of the microcapsules is 0.01
To 20 μm is preferable, 0.05 to 2.0 μm is more preferable, and 0.10 to 1.0 μm is most preferable. As for the microcapsules, the capsules may be fused by heat. That is, among the microcapsule-encapsulated materials, what oozes out on the surface of the capsule or outside the microcapsule at the time of application or penetrates into the microcapsule wall may cause a chemical reaction by heat. You may use together two or more types of microcapsules. The amount of microcapsules added to the image forming layer is 10 to 60% by mass, and more preferably 15 to 40% by mass in terms of solid content. Within this range, good on-press developability as well as good sensitivity and printing durability can be obtained.

When the microcapsules are added to the image forming layer, a solvent capable of dissolving the inclusions and swelling the wall material can be added to the microcapsule dispersion medium. Such a solvent promotes the diffusion of the encapsulated compound having the heat-reactive functional group to the outside of the microcapsules.
As the solvent, alcohol, ether, acetal, ester, ketone, polyhydric alcohol, amide, amine and fatty acid can be used. Examples of preferred solvents include methanol, ethanol, n-propanol, t-butanol, tetrahydrofuran, methyl lactate, ethyl lactate,
Included are methyl ethyl ketone, propylene glycol monomethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, γ-butyl lactone, N, N-dimethylformamide and N, N-dimethylacetamide. You may use together 2 or more types of solvents. The amount of the solvent added is preferably 5 to 95% by mass of the coating liquid, more preferably 10 to 90% by mass,
Most preferably, it is 15 to 85% by mass.

[Compound having a plurality of dienophile structures] Crosslinking can be performed only with a polymer having an o-quinodimethane structure or its precursor structure, but a compound having a plurality of dienophile structures can be used to produce Diels-
The Alder reaction can be more strongly crosslinked. That is, the printing durability of the printing plate can be further improved. Dienophile structures are generally Diel
It is synonymous with the unsaturated bond defined in the s-Alder reaction. That is, if it is an unsaturated bond that reacts with a diene to cause a Diels-Alder reaction, a carbon-carbon double bond (>
Not only C = C <) and carbon-carbon triple bond (-C≡C-), but also carbonyl group (> C = O) and nitroso group (-N =
O) and azo bonds (-N = N-) such as unsaturated bonds involving atoms other than carbon. However, a carbon-carbon double bond (> C = C <) is most preferable.

Compounds having a plurality of dienophile structures include unsaturated carboxylic acids (eg acrylic acid, methacrylic acid) and polyhydric alcohols (eg glycol, glycerol, pentaerythritol, dipentaerythritol).
By condensation of an ester or an unsaturated dicarboxylic acid (eg maleic acid) or an unsaturated dicarboxylic acid anhydride (eg maleic anhydride) with a polyamine (eg methylenediamine, phenylenediamine, di (aminophenyl) methane) The imide obtained is particularly preferable. The compound having a plurality of dienophile structures is preferably represented by the following formula (III).

(III) (Di-) _n L ²

In the formula (III), Di is a dienophile structure. In the formula (III), L ² is an n-valent organic residue, and n is 2, 3, 4, 5 or 6. L ²
Is an aliphatic group, an aromatic group, a heterocyclic group, -O-, -CO
-, - SO -, - SO 2 -, - NH -, - N <, - PO
It is preferably an n-valent organic residue selected from <and combinations thereof, and is a divalent, trivalent or tetravalent aliphatic group, a divalent, trivalent or tetravalent aromatic group, divalent or trivalent. Valent or tetravalent heterocyclic group, -O-, -CO-, -NH-,-
More preferably, it is an n-valent organic residue selected from N <and a combination thereof. The portion where L ² is bonded to the dienophile structure is preferably —O—, —CO—, —NH— or an aliphatic group (divalent, trivalent or tetravalent). Below, the example of the compound represented by Formula (III) is shown.

[0066]

[Chemical formula 23]

[0067]

[Chemical formula 24]

[0068]

[Chemical 25]

[0069]

[Chemical formula 26]

A polymer having a plurality of dienophile structures can be used as the compound having a plurality of dienophile structures. The polymer can also function as a hydrophobic polymer. The dienophile structure is preferably contained in the side chain of the polymer. The polymer main chain is preferably selected from hydrocarbons (polyolefins), polyesters, polyamides, polyimides, polyureas, polyurethanes, polyethers and combinations thereof. A hydrocarbon backbone is especially preferred.

The main chain of the polymer may have a substituent in addition to the side chain containing the dienophile structure. Examples of the substituent include halogen atom (F, Cl, Br, I), hydroxyl, mercapto, carboxyl, sulfo, sulfate ester group, phosphono, phosphate ester group, cyano, aliphatic group, aromatic group, heterocycle. Group, -OR, -SR, -CO
-R, -NH-R, -N (-R) ₂ , -N ⁺ (-
R) ₃ , -CO-OR, -O-CO-R, -CO-N
HR, -NH-CO-R and -P (= O) (-O-
R) ₂ is included. The R's are each an aliphatic group, an aromatic group or a heterocyclic group. Carboxyl, sulfo,
Sulfate group, phosphono and phosphate group are
The hydrogen atom may be dissociated or may be in a salt state. A plurality of substituents on the main chain may combine to form an aliphatic ring or a heterocycle. The formed ring may have a bond of a main chain and a spiro bond. The ring formed may have a substituent. Examples of the substituent include oxo (═O) in addition to the above-mentioned main chain substituent.

The polymer preferably has a repeating unit containing a dienophile structure represented by the following formula (IV) in the side chain.

[0073]

[Chemical 27]

In the formula (IV), Di is a dienophile structure. In the formula (IV), R ³ is a hydrogen atom, a halogen atom (F, Cl, Br, I) or an alkyl group having 1 to 10 carbon atoms. R ³ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and is preferably a hydrogen atom or methyl. Is most preferred.

In the formula (IV), L ³ is independently a single bond or a divalent linking group. The divalent linking group is -CO-, -O-, -S-, -NH-, -SO.
It is preferably selected from _2- , alkylene groups, arylene groups and combinations thereof. The alkylene group preferably has 1 to 12 carbon atoms, and 1
Is more preferably 8 to 8, and most preferably 1 to 6. The alkylene group may have a cyclic structure or a branched structure. The alkylene group may have a substituent. The substituent of the alkylene group is the same as the above-mentioned substituent of the aliphatic group. The above arylene group is
It is preferably phenylene or naphthylene, more preferably phenylene, most preferably p-phenylene. The arylene group may have a substituent. The substituent of the arylene group is the same as the substituent of the aromatic group described above. Hereinafter, examples of L ^3. The left side is attached to the main chain, and the right side is the dienophile structure (D
bind to i). AL is an alkylene group.

[0076] L30: Single bond L31: -O- L32: -CO-O- L33: -CO-O-AL- L34: -CO-O-AL-O- L35: -CO-O-AL-O-CO- L36: -CO-NH- L37: -CO-NH-AL-O- L38: -CO-NH-AL-NH-

Examples of repeating units having a dienophile structure are shown below.

[0078]

[Chemical 28]

[0079]

[Chemical 29]

[0080]

[Chemical 30]

[0081]

[Chemical 31]

[0082]

[Chemical 32]

[0083]

[Chemical 33]

[0084]

[Chemical 34]

[0085]

[Chemical 35]

[0086]

[Chemical 36]

[0087]

[Chemical 37]

A homopolymer consisting only of repeating units having a dienophile structure can be used. Also,
A copolymer containing two or more kinds of repeating units having a dienophile structure can also be used. Further, a copolymer composed of a repeating unit having a dienophile structure and another repeating unit can also be used. Examples of other repeating units are shown below.

[0089]

[Chemical 38]

[0090]

[Chemical Formula 39]

[0091]

[Chemical 40]

[0092]

[Chemical 41]

When the image-forming layer in the unheated portion is removed by treating with an alkaline eluent, the polymer preferably has an acidic group. The acidic group is preferably introduced into a repeating unit containing no dienophile structure as a copolymer of a polymer. As the acidic group, carboxyl (in the above example, V-1, V-2, V
-8) or carboxylic acid anhydride is preferred.

A repeating unit containing a dienophile structure,
When a copolymer is formed by combining a repeating unit not containing a dienophile structure, the ratio of the repeating unit containing a dienophile structure / the repeating unit not containing a dienophile structure is 5/95 to 99/1. It is preferably 10/90 to 98/2, more preferably 20/80 to 97/3. The following is an example of a copolymer composed of a repeating unit containing a dienophile structure and a repeating unit not containing a dienophile structure. The numbers in parentheses correspond to the exemplified numbers with the above repeating unit. The proportion of repeating units is mol%.

[0095] _{CP101 :-( IV-2) 80 -} (V-2) 20 - CP102 :-( IV-8) 30 - (V-4) 50 - (V-2) 20 - CP103 :-( IV- _{8) 30 - (V-4} ) 40 - (V-6) 20 - (V-2) 10 - CP104 :-( IV-10) 30 - (V-4) 50 - (V-2) 20 - CP105 _{:-( IV-14) 70 - (} V-2) 30 - CP106 :-( IV-17) 62 - (V-2) 38 - CP107 :-( IV-20) 35 - (V-8) 15 - (V-7) _50-

The polymer can be synthesized by a polymerization reaction of a monomer (generally an ethylenically unsaturated monomer) corresponding to the above repeating unit. A radical polymerization reaction, a cationic polymerization reaction, or an anionic polymerization reaction can be adopted as a specific polymerization reaction. The dienophile structure may be introduced after the synthesis of the main chain polymer. Even when the main chain is other than hydrocarbon (for example, polyurethane), it can be synthesized by a general polymerization reaction (for example, urethane polymerization reaction). The amount of the compound having a plurality of dienophile structures used may be adjusted by calculating the ratio between the number of dienophile structures and the number of o-quinodimethane structures or precursor structures thereof. The weight average molecular weight of the polymer is preferably from 500 to 1,000,000, more preferably from 1,000 to 500,000, even more preferably from 2,000 to 200,000.
Most preferably, it is from 1,000 to 100,000.

[Hydrophilic Polymer] When the hydrophobic polymer is used as the fine particles, it is preferable to use the hydrophilic polymer as a binder for the fine particles in the image forming layer. The hydrophilic group of the hydrophilic polymer is preferably a hydroxyl, carboxyl, sulfo, amino or amide bond. Carboxyl and sulfo may be in a salt state. As the hydrophilic polymer, various natural or semi-synthetic polymers or synthetic polymers can be used. As the natural or semi-synthetic polymer, a polysaccharide (eg gum arabic, starch derivative, carboxymethyl cellulose, its sodium salt, cellulose acetate, sodium alginate) or a protein (eg casein, gelatin) can be used.

Examples of synthetic polymers having hydroxyl as a hydrophilic group include polyhydroxyethyl methacrylate, polyhydroxyethyl acrylate, polyhydroxypropyl methacrylate, polyhydroxypropyl acrylate, polyhydroxybutyl methacrylate, polyhydroxybutyl acrylate, polyallyl alcohol. , Polyvinyl alcohol and poly-N-methylol acrylamide. Examples of synthetic polymers having a carboxyl as a hydrophilic group include polymaleic acid, polyacrylic acid, polymethacrylic acid and salts thereof. Examples of synthetic polymers having other hydrophilic groups (eg, amino, multiple ether bonds, hydrophilic heterocyclic groups, amide bonds, sulfo) include polyethylene glycol, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide, methacryl. Amides and 2-acrylamido-2-methylpropanesulfonic acid and salts thereof are included.

A copolymer having two or more kinds of repeating units of the hydrophilic synthetic polymer may be used. A copolymer containing a repeating unit of a hydrophilic synthetic polymer and a repeating unit of a hydrophobic synthetic polymer (eg, polyvinyl acetate, polystyrene) may be used. Examples of copolymers include vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers and vinyl alcohol-vinyl acetate copolymers (partially saponified polymers of polyvinyl acetate). When a vinyl alcohol-vinyl acetate copolymer is synthesized by partial saponification of polyvinyl acetate, the saponification degree is preferably 60% by mass or more, and 80% by mass.
It is more preferable that the above is satisfied. You may use together two or more types of hydrophilic polymers. The hydrophilic polymer is preferably contained in the image forming layer in an amount of 2 to 40% by mass.
It is more preferable that the content is from 30 to 30 mass%.

[Photothermal Conversion Agent] The image forming layer preferably contains a photothermal conversion agent. The photothermal conversion agent is a substance having a function of absorbing light, converting light energy into heat energy, and generating heat. The photothermal conversion agent can be present inside the hydrophobic polymer particles. The photothermal conversion agent may be added outside the fine particles (in the hydrophilic binder). The wavelength of light absorbed by the photothermal conversion agent (maximum absorption wavelength) is 70
It is particularly preferably 0 nm or more (infrared light). Pigments, dyes or fine metal particles capable of absorbing infrared light can be preferably used as the photothermal conversion agent.

Regarding the infrared absorbing pigment, a color index (CI) handbook, "latest pigment handbook" (edited by Japan Pigment Technology Association, published in 1977), "latest pigment application technology" (C
MC Publishing, 1986, "Printing Ink Technology" (CM
C Publishing, published in 1984). A particularly preferred infrared absorbing pigment is carbon black. When the infrared absorbing pigment is added to the hydrophobic polymer or inside the fine particles of the hydrophobic polymer, the pigment can be subjected to a hydrophobizing (lipophilicizing) treatment. As the hydrophobic treatment, there is a method of coating the surface of the pigment with a lipophilic resin. When the infrared absorbing pigment is dispersed in the hydrophilic polymer, the pigment can be subjected to a hydrophilic treatment. As the hydrophilic treatment, a method of coating the surface of the pigment with a hydrophilic resin, a method of attaching a surfactant to the surface of the pigment, or a reactive substance (eg, silica sol,
A method of binding an alumina sol, a silane coupling agent, an epoxy compound, an isocyanate compound) to the pigment surface can be adopted. The particle size of the pigment is preferably 0.01 to 1 μm, more preferably 0.01 to 0.5 μm. When the pigment is dispersed in the hydrophilic polymer, a known dispersion technique used in ink production or toner production can be applied.

Regarding the infrared absorbing dyes, edited by "Dye Handbook", Organic Synthetic Chemistry Association, published in 1970, "Chemical Industry" 19
May 1986 issue P. 45-51 "near infrared absorbing dye",
"Development of 90's functional dyes and market trends" Chapter 2 2.3
See (1990) CMC. Preferred infrared absorbing dyes are azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, and naphthoquinone dyes (JP-A-58-1127).
No. 93, No. 58-224793, No. 59-48187.
No. 59-73996, No. 60-52940, No. 60-63744), anthraquinone dye, phthalocyanine dye (JP-A-11-235883), squarylium dye (JP-A-58-112).
792), pyrylium dye (US Pat. No. 388)
1924 and 4283475, each specification, JP-A-5
7-142645, 58-181051, 58.
-220143, 59-41363, 59-8
No. 4248, No. 59-84249, No. 59-1460.
63, 59-146061, JP-B-51351
4 and 5-19702), carbonium dyes, quinoneimine dyes and methine dyes (Japanese Patent Application Laid-Open No. Sho 5).
8-173696, 58-181690, 58
No. 194595).

For infrared absorbing dyes, US Pat.
It is also described in each specification of 6993 and 5156938 and JP-A-10-268512. A commercially available infrared absorbing dye (for example, Epolite III-178, Epolite III-130, Epolite III-125, manufactured by Eporin) may be used. Methine dyes are more preferred, and cyanine dyes (UK Patent 434875, US Patent 497
No. 3572, JP-A-58-125246,
59-84356, 59-216146, 6
0-78787). The cyanine dye is defined by the following formula. Bo-Le = Bs In the above formula, Bs is a basic nucleus; Bo is an onium body of a basic nucleus; and Le is a methine chain composed of an odd number of methines. In the case of infrared absorbing dyes,
Le is preferably a methine chain composed of 7 methines.

When the infrared absorbing dye is added to the hydrophilic polymer of the image forming layer, it is preferable to use a hydrophilic dye. Examples of hydrophilic infrared absorbing dyes are shown below.

[0105]

[Chemical 42]

[0106]

[Chemical 43]

[0107]

[Chemical 44]

[0108]

[Chemical formula 45]

[0109]

[Chemical formula 46]

[0110]

[Chemical 47]

When adding the infrared absorbing dye into the fine particles of the hydrophobic polymer, it is preferable to use a relatively hydrophobic dye. Examples of hydrophobic infrared absorbing dyes are shown below.

[0112]

[Chemical 48]

[0113]

[Chemical 49]

[0114]

[Chemical 50]

[0115]

[Chemical 51]

The metal generally has a self-heating property.
Therefore, metals with absorption in the infrared, visible or ultraviolet region,
In particular, a metal having absorption in the infrared region has a light-heat conversion function. The metal forming the metal fine particles is preferably heat-sealed by light irradiation. Specifically, the melting point is 100.
It is preferably 0 ° C. or lower. As the metal constituting the metal fine particles, Si, Al, Ti, V, Cr, Mn, F
e, Co, Ni, Cu, Zn, Y, Zr, Mo, Ag,
Au, Pt, Pd, Rh, In, Sn, W, Te, P
b, Ge, Re, Sb and alloys thereof are preferred,
Re, Sb, Te, Ag, Au, Cu, Ge, Pb and Sn are more preferable, and Ag, Au, Cu, Sb and Ge are more preferable.
And Pb are more preferred, and Ag, Au and Cu are most preferred.

In the case of an alloy, a low melting point metal (eg Re, S
b, Te, Au, Ag, Cu, Ge, Pb, Sn),
Metals with high self-heating properties (eg Ti, Cr, Fe, Co,
Ni, W, Ge) can also be combined. It is also possible to use fine particles of a metal (eg, Ag, Pt, Pd) having a large light absorption and fine particles of another metal in combination. The metal fine particles are preferably dispersed in the hydrophilic polymer by subjecting the surface to hydrophilic treatment.
As the surface hydrophilic treatment, means such as surface treatment with a hydrophilic substance (eg, surfactant), surface chemical reaction with the hydrophilic substance, or formation of a hydrophilic polymer film can be adopted. A method such as providing a protective colloid hydrophilic polymer film can be used. A surface chemical reaction with a hydrophilic substance is preferred, and a surface silicate treatment is most preferred.
In the surface silicate treatment of iron fine particles, the surface can be made sufficiently hydrophilic by a method of immersing the iron fine particles in an aqueous sodium silicate (3%) solution at 70 ° C. for 30 seconds. Other metal fine particles can be subjected to surface silicate treatment in the same manner. Metal oxide particles or metal sulfide particles may be used instead of the metal particles. The particle size of the fine particles is preferably 10 μm or less, and is 0.0
It is more preferably from 03 to 5 μm, and 0.01
Most preferably from 3 to 3 μm.

[Other Optional Components of Image Forming Layer] A colorant may be added to the image forming layer for the purpose of distinguishing the image area and the non-image area after image formation. As the colorant, a dye or pigment having a large absorption in the visible region is used. Examples of colorants are Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 60.
3, Oil Black BY, Oil Black BS, Oil Black T-505 (above Orient Chemical Industry Co., Ltd.)
Made), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42)
535), ethyl violet, rhodamine B (CI1
45170B), Malachite Green (CI4200
0) and methylene blue (CI52015). Regarding the dyes used as the colorant, see JP-A-6-61.
It is described in JP-A-2-293247. Inorganic pigments such as titanium oxide can also be used as colorants. The addition amount of the colorant is preferably 0.01 to 10% by mass of the image forming layer.

The image-forming layer contains a nonionic surfactant (JP-A-62-25174) in order to enhance the stability of on-press development.
No. 0, JP-A-3-208514) or an amphoteric surfactant (JP-A-59-121044, JP-A-4-13149). Examples of nonionic surfactants include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride and polyoxyethylene nonyl phenyl ether. Examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-
Alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-
An N, N-betaine type surfactant (Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.) is included. The nonionic surfactant and amphoteric surfactant are contained in the image forming layer in an amount of 0.05 to 15% by mass.
It is preferably contained, and more preferably 0.1 to 5% by mass.

A plasticizer may be added to impart flexibility to the image forming layer. Examples of plasticizers include polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate and tetrahydrofurfuryl oleate. .

[Formation of Image-Forming Layer] The image-forming layer is prepared by dissolving, dispersing or emulsifying each component in a suitable liquid medium to prepare a coating solution, coating the solution on a support, and drying to prepare a liquid medium. Can be formed by removing. Examples of the liquid medium used in the coating liquid, 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-Butyl lactone, toluene and water are included. Two or more kinds of liquids may be mixed and used. The total solid content concentration of the coating liquid is preferably 1 to 50% by mass.

A surfactant for improving the coatability can be added to the coating liquid. Fluorine-based surfactants (described in JP-A-62-170950) are particularly preferable. The addition amount of the surfactant is preferably 0.01 to 1% by mass with respect to the solid content of the coating liquid, and is 0.05
To 0.5 mass% is more preferable. The dry coating amount of the image forming layer is preferably 0.5 to 5.0 g / m ² .

[Support] For use as a printing original plate, the support is preferably hydrophilic. As the hydrophilic support, a metal plate, a plastic film or paper can be used. Specifically, a surface-treated aluminum plate, a hydrophilic-treated plastic film or a water-resistant treated paper is preferable. More specifically, an anodized aluminum plate, a polyethylene terephthalate film provided with a hydrophilic layer, or a polyethylene-laminated paper is preferable.

Particularly preferred is an anodized aluminum plate. The aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of a foreign element. Examples of foreign elements contained in aluminum alloys are:
Includes silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The ratio of the foreign element is preferably 10% by mass or less. You may use the aluminum plate for commercial printing plates. The thickness of the aluminum plate is preferably 0.05 to 0.6 mm, more preferably 0.1 to 0.4 mm, and most preferably 0.15 to 0.3 mm.

The surface of the aluminum plate is preferably roughened. The roughening treatment can be performed by a mechanical method, an electrochemical method or a chemical method. As the mechanical method, a ball polishing method, a brush polishing method, a blast polishing method or a buff polishing method can be adopted. As the electrochemical method, a method of performing alternating current or direct current in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid can be adopted. An electrolytic surface-roughening method using a mixed acid (described in JP-A-54-63902) can also be used. As a chemical method, a method of immersing an aluminum plate in a saturated aqueous solution of an aluminum salt of mineral acid (described in JP-A-54-31187) is suitable. The roughening treatment is preferably performed so that the center line average roughness (Ra) of the surface of the aluminum plate is 0.2 to 1.0 μm. The roughened aluminum plate is subjected to alkali etching treatment if necessary. An aqueous solution of potassium hydroxide or sodium hydroxide is generally used as the alkaline treatment liquid. After the alkali etching treatment, it is preferable to further perform a neutralization treatment.

The anodic oxidation treatment of the aluminum plate is carried out in order to enhance the abrasion resistance of the support. As the electrolyte used for the anodizing treatment, various electrolytes forming a porous oxide film can be used. Generally, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used as the electrolyte. The anodizing treatment conditions are generally such that 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 / dm ² , voltage of 1 to 100 V, and
The electrolysis time is in the range of 10 seconds to 5 minutes. The amount of oxide film formed by anodizing treatment is 1.0 to 5.0 g /
It is preferably m ² and is 1.5 to 4.0 g / m ^2.
Is more preferable.

[Water-soluble overcoat layer] A water-soluble overcoat layer may be provided on the image-forming layer to prevent the surface of the image-forming layer from being contaminated by a lipophilic substance. The water-soluble overcoat layer is composed of a material that can be easily removed during printing. For that purpose, it is preferable to form the water-soluble overcoat layer from a water-soluble organic polymer. Examples of water-soluble organic polymers include polyvinyl alcohol, polyvinyl acetate, polyacrylic acid, alkali metal salts or amine salts thereof, polymethacrylic acid, alkali metal salts or amine salts thereof, polyacrylamide, polyhydroxyethyl acrylate, polyvinyl. Pyrrolidone, polyvinyl methyl ether, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, its alkali metal salts or amine salts, gum arabic, cellulose ether (eg, carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose), dextrin and Included are derivatives thereof (eg, white dextrin, enzyme-degraded etherified dextrin pullulan).
A copolymer having two or more kinds of repeating units of water-soluble organic polymer may be used. Examples of copolymers include vinyl alcohol-vinyl acetate copolymers (partially saponified polymers of polyvinyl acetate) and vinyl methyl ether-maleic anhydride copolymers. When a vinyl alcohol-vinyl acetate copolymer is synthesized by partial saponification of polyvinyl acetate, the saponification degree is preferably 65% by mass or more. You may use together two or more types of water-soluble organic polymers.

The above photothermal conversion agent may be added to the overcoat layer. The photothermal conversion agent added to the overcoat layer is preferably water-soluble. A nonionic surfactant (eg, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecyl ether) can be added to the coating solution for the overcoat layer. The coating amount of the overcoat layer is preferably 0.1 to 2.0 g / m ² .

[Image Forming Method] The present invention can be applied to various image forming methods. In the present invention, the step of imagewise heating the image-forming material to crosslink the polymer, and the step of removing the image-forming layer in the unheated portion,
A replica image made of a crosslinked polymer can be formed. The replica image can function as an optical filter or a resist of an integrated circuit. In addition, a three-dimensional image is formed by repeatedly forming replica images using a heat mode laser (optical 3D
Molding) is also possible. Further, the replica image can be used as a color proof. The color proof is roughly classified into a transfer method and an overlay method. The replica image formed according to the present invention can be applied to both methods. The replica image can also be used as a printing plate such as intaglio or letterpress.

The most typical uses of the present invention are plate making methods and lithographic printing methods. In plate making of the lithographic printing plate, a step of heating the lithographic printing plate precursor imagewise to crosslink the hydrophobic polymer (imagewise heating step), and a step of removing the image forming layer in the unheated portion (platemaking Process). In lithographic printing, the lithographic printing original plate is imagewise heated to crosslink the hydrophobic polymer (imagewise heating step), the lithographic printing original plate is mounted on the printing machine, the printing machine is operated, dampening water, A step of removing the image forming layer which is not heated by ink or rubbing, thereby making a lithographic printing plate (plate making step), and further supplying a fountain solution and an oil-based ink to make a lithographic printing plate. The step of printing in (printing step) is performed.

[Image-like heating step] The lithographic printing original plate is imagewise heated to form an image. Directly, the lithographic printing plate precursor can be imagewise heated by the thermal recording head. In that case, the photothermal conversion agent is unnecessary. However, since the thermal recording head generally has a low image resolution, it is desirable to use a photothermal conversion agent to convert light energy by image exposure into heat energy. Generally, the exposure device used for image exposure has higher resolution than the thermal recording head. The exposure method includes exposure through an original (original) which is analog data and scanning exposure corresponding to original data (usually digital data). For exposure through the original, a xenon discharge lamp or an infrared lamp is used as a light source. If a high-power light source such as a xenon discharge lamp is used, short-time flash exposure is possible. Scanning exposure generally uses a laser, particularly an infrared laser. Infrared wavelength is 700 to 1
It is preferably 200 nm. The infrared ray is preferably a solid high-power infrared laser (for example, a semiconductor laser or a YAG laser).

When the image forming layer containing a photothermal conversion agent is scanned and exposed with a laser, the light energy of the laser is converted into thermal energy by the photothermal conversion agent. Then, in the heated portion (image portion) of the lithographic printing original plate, the hydrophobic polymer is crosslinked and cured. When a hydrophobic polymer is used as the fine particles, the hydrophobic polymer fine particles are fused at the heating portion,
Form the hydrophobic regions attached to the hydrophilic support. On the other hand, there is no change in the hydrophobic polymer in the non-heated portion (non-image portion) of the lithographic printing original plate.

[Plate making process and printing process] The planographic printing plate precursor image-wise heated can be developed to develop a planographic printing plate. When the hydrophobic polymer is not used as fine particles (when the image forming layer is a uniform layer containing the hydrophobic polymer), by introducing an acidic group into the hydrophobic polymer, the unheated part (non-image part The hydrophobic polymer of) can be eluted. When the hydrophobic polymer is used as the fine particles, the hydrophobic polymer fine particles in the non-heated portion (non-image portion) can be removed with water or an aqueous solvent. However, even if the process of removing fine particles (development process) is not carried out, the planographic printing plate precursor that has been imagewise heated can be immediately mounted in the printing machine and printed in the usual procedure using ink and fountain solution. The plate making and printing can be continuously performed. That is, when the planographic printing original plate is mounted on a printing machine and the printing machine is operated, the image forming layer in the non-heated portion (non-image portion) can be removed by dampening water, ink, or rubbing. When a printing machine having a laser exposure device (described in Japanese Patent No. 2938398) is used, after the lithographic printing original plate is mounted on the printing machine cylinder, it is exposed by a laser installed in the printing machine,
After that, it is also possible to apply dampening water or ink and perform on-machine development (exposure to printing are continuously processed). Also,
Strength of printing plate (printing durability) by further heating the entire plate to make unreacted compounds remain in the image area
Can be further improved.

[0134]

EXAMPLES [Example 1] (Preparation of aluminum support) 99.5% or more of aluminum, Fe 0.30%, Si 0.10%, Ti
JIS A105 containing 0.02% and Cu 0.013%
The molten alloy No. 0 was subjected to a cleaning treatment and cast. For the cleaning treatment, degassing treatment was performed to remove unnecessary gas such as hydrogen in the molten metal, and ceramic tube filter treatment was performed. The casting method was a DC casting method. The solidified ingot having a plate thickness of 500 mm was chamfered by 10 mm from the surface, and homogenized at 550 ° C. for 10 hours so as not to coarsen the intermetallic compound. Then, hot rolling at 400 ° C,
After intermediate annealing at 500 ° C. for 60 seconds in a continuous annealing furnace, cold rolling was performed to obtain a rolled aluminum plate having a plate pressure of 0.30 mm. The center line average surface roughness Ra after cold rolling was controlled to 0.2 μm by controlling the roughness of the rolling roll. Then, a tension leveler was applied to improve the flatness.

Next, a surface treatment was carried out to obtain a lithographic printing plate support. First, in order to remove the rolling oil on the surface of the aluminum plate, degreasing treatment was performed with a 10 mass% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and then with a 30 mass% sulfuric acid aqueous solution.
Neutralization and smut removal treatment were carried out at 0 ° C. for 30 seconds.

Next, in order to improve the adhesion between the support and the image-forming layer and to impart water retention to the non-image area, a so-called graining treatment was carried out to roughen the surface of the support. 1
An alternating solution with a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect power supply cell while keeping an aqueous solution containing 45% by mass of nitric acid and 0.5% by mass of aluminum nitrate at 45 ° C. and flowing an aluminum web in the aqueous solution. Waveform on the anode side electricity quantity 24
Electrolytic graining was performed by applying 0 C / dm ² . Then, with a 10 mass% sodium aluminate aqueous solution at 50 ° C., 3
Etching treatment was performed for 0 seconds, neutralization with a 30 mass% sulfuric acid aqueous solution at 50 ° C. for 30 seconds, and smut removal treatment were performed.

Further, in order to improve abrasion resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. Anodized film of 2.5 g / m ² is obtained by using a 20% aqueous solution of sulfuric acid as an electrolyte at 35 ° C. and carrying out an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power supply cell while carrying the aluminum web through the electrolyte. It was created. After that, a silicate treatment was performed in order to secure hydrophilicity as a non-image portion of the printing plate. The treatment was carried out by keeping a 1.5% by mass aqueous solution of No. 3 sodium silicate at 70 ° C. so that the contact time of the aluminum web was 15 seconds, and further washing with water. The amount of Si deposited is 10
It was mg / m ² . The center line surface roughness Ra of the support produced as described above was 0.25 μm.

(Formation of Undercoat Layer) Aluminum support surface
Apply the undercoat layer coating solution of the following composition on the surface,
It was dried for 30 seconds to form an undercoat layer. Undercoat dry
Dry coating amount is 10 g / m ²Met.

[0139] ────────────────────────────────────   Undercoat layer coating composition ────────────────────────────────────   β-alanine 0.10 g   40 g of methanol   Pure water 60g ────────────────────────────────────

(Preparation of Carbon Black Dispersion) The following composition was dispersed using glass beads for 10 minutes to prepare a carbon black dispersion.

[0141] ────────────────────────────────────   Carbon black dispersion composition ────────────────────────────────────   Carbon black having a particle size of 0.2 to 0.3 μm 1.0 part by mass   Benzyl methacrylate / methacrylic acid copolymer (molar ratio: 72/29, quality Weight average molecular weight: 70,000) 1.6 parts by mass   Methyl ethyl ketone 1.6 parts by mass   1-methoxy-2-propanol 3.8 parts by mass ────────────────────────────────────

(Formation of Image Forming Layer) An image forming layer coating liquid having the following composition was prepared.

[0143] ────────────────────────────────────   Composition of coating liquid for image forming layer ────────────────────────────────────   Carbon black dispersion 2.4g   20 mass% methyl ethyl of copolymer CP2 (mass average molecular weight: 30,000) 2.2 g of ketone solution   Fluorine-based surfactant (MegaFac F-176, Dainippon Ink and Chemicals, Inc.) Made) 0.06g   Methyl ethyl ketone 15g   2-methoxy-1-propanol 12 g ────────────────────────────────────

[0144]

[Chemical 52]

The coating solution for the image forming layer was applied onto the undercoat layer of the aluminum support and dried at 70 ° C. for 5 minutes to form an image forming layer. The mass of the image forming layer after drying is
It was 2.0 g / m ² . In this way, a lithographic printing original plate was produced.

(Plate making, printing and evaluation) An image setter (Trendsetter 3244VFS, made by Creo) in which a water-cooled 40W infrared semiconductor laser is mounted on the prepared lithographic printing plate precursor.
At 9V output, 210 rpm outer drum speed,
Plate energy of 400 mJ / m ² and 2400 d
Image exposure was performed under the condition of pi resolution. Next, an alkaline developing solution having a pH of 13 (DP-4 developing solution, 1: 8 diluted solution manufactured by Fuji Photo Film Co., Ltd.) and a rinsing solution (FR-3,
When processed through an automatic processor equipped with Fuji Photo Film Co., Ltd.'s 1: 7 diluted solution, a clear negative image was obtained. The lithographic printing plate thus obtained is printed on a printing machine (Heidel SO
When printed with R-KZ), good printed matter was obtained. The number of printable sheets was 12000. Separately, the obtained lithographic printing plate was further heated on the entire surface at 160 ° C. for 1 minute.
Press the lithographic printing plate after heating (Heidel SOR-KZ)
When printed with, a good printed matter was obtained. The number of printable sheets was 23,000.

[Examples 2 to 4] A lithographic printing plate precursor was prepared in the same manner as in Example 1 except that the hydrophobic polymer added to the coating liquid for the image forming layer was changed as shown in Table 1 below. Then, it was printed and evaluated. The results are shown in Table 1.

[0148]

[Table 1]                                 Table 1 ──────────────────────────────────── Lithographic printing original plate Hydrophobic polymer (mass average molecular weight) ────────────────────────────────────   Example 1 Copolymer CP2 (30000) 12000 sheets   Example 2 Copolymer CP9 (28000) 14,000 sheets   Example 3 Copolymer CP19 (40000) 16000 sheets   Example 4 Copolymer CP25 (20,000) 13,000 sheets ────────────────────────────────────

[0149]

[Chemical 53]

[0150]

[Chemical 54]

[0151]

[Chemical 55]

Example 5 (Formation of Image Forming Layer) An image forming layer coating liquid having the following composition was prepared.

[0153] ────────────────────────────────────   Composition of coating liquid for image forming layer ────────────────────────────────────   2.4 g of the carbon black dispersion used in Example 1   20 mass% methyl ethyl of copolymer CP2 (mass average molecular weight: 30,000) 2.2 g of ketone solution   4,4'-bismaleimidodiphenylmethane 0.1 g   Fluorine-based surfactant (MegaFac F-176, Dainippon Ink and Chemicals, Inc.) Made) 0.06g   Methyl ethyl ketone 15g   2-methoxy-1-propanol 12 g ────────────────────────────────────

The coating solution for image forming layer was applied on the undercoat layer of the aluminum support formed in Example 1 and dried at 70 ° C. for 5 minutes to form an image forming layer. The mass of the image forming layer after drying was 2.0 g / m ² . In this way, a lithographic printing original plate was produced.

(Plate making, printing and evaluation) An image setter (Trendsetter 3244VFS, made by Creo) in which a water-cooling type 40W infrared semiconductor laser is mounted on the prepared planographic printing original plate.
At 9V output, 210 rpm outer drum speed,
Plate energy of 400 mJ / m ² and 2400 d
Image exposure was performed under the condition of pi resolution. Next, an alkaline developing solution having a pH of 13 (DP-4 developing solution, 1: 8 diluted solution manufactured by Fuji Photo Film Co., Ltd.) and a rinsing solution (FR-3,
When processed through an automatic processor equipped with Fuji Photo Film Co., Ltd.'s 1: 7 diluted solution, a clear negative image was obtained. The lithographic printing plate thus obtained is printed on a printing machine (Heidel SO
When printed with R-KZ), good printed matter was obtained. The number of printable sheets was 18,000.

[Examples 6 to 8] The same as Example 5 except that the hydrophobic polymer and the compound having a plurality of dienophile structures added to the coating liquid for the image forming layer were changed as shown in Table 2 below. Produce a planographic printing plate,
Printed and evaluated. The results are shown in Table 2. The weight average molecular weight of the hydrophobic polymer is the same as in Table 1.

[0157]

[Table 2]                                 Table 2 ──────────────────────────────────── Printing original plate Polymer Compound with multiple dienophile structure ──────────────────────────────────── Example 5 CP2 4,4'-bismaleimidodiphenylmethane 18000 Example 6 CP9 pentaerythritol tetraacrylate 20000 Example 7 CP19 dipentaerythritol hexaacrylate 22000 Example 8 CP25 4,4'-Bismaleimidodiphenylmethane 19000 ────────────────────────────────────

[Example 9] (Preparation of fine particle dispersion of hydrophobic polymer) Homopolymer consisting of repeating unit (I-1) (mass average molecular weight: 2)
5000) 6g, infrared absorbing dye (IR-24) 1.5
g and anionic surfactant (Bionin A-41
0.1 g of C, manufactured by Takemoto Yushi Co., Ltd.) was dissolved in a mixed solvent of 7.4 g of methyl ethyl ketone and 13.7 g of ethyl acetate. The solution is changed to polyvinyl alcohol (PVA
205, 53 g of 1.8 mass% aqueous solution of Kuraray Co., Ltd.
And mix with a homogenizer at 15,000 rpm for 10
The mixture was stirred for a minute and emulsified. After stirring at 40 ° C. for 3 hours, methyl ethyl ketone and ethyl acetate were evaporated. The solid content concentration of the obtained hydrophobic polymer fine particle dispersion was 15.4% by mass. The average particle size of the fine particles was 0.30 μm.

(Formation of Image Forming Layer) An image forming layer coating liquid having the following composition was prepared.

[0160] ────────────────────────────────────   Composition of coating liquid for image forming layer ────────────────────────────────────   25 g of water   Hydrophobic polymer particle dispersion 20g ────────────────────────────────────

The coating solution for image forming layer was applied on the undercoat layer of the aluminum support formed in Example 1 with a bar coater and dried in an oven at 60 ° C. for 120 seconds to form an image forming layer. The mass of the image forming layer after drying is 1.
It was 0 g / m ² . In this way, a lithographic printing original plate was produced.

(Plate making, printing and evaluation) An image setter (Trendsetter 3244VFS, made by Creo) in which a water-cooled 40 W infrared semiconductor laser is mounted on the prepared planographic printing plate.
At 9V output, 210 rpm outer drum speed,
Plate energy of 300 mJ / m ² and 2400 d
Image exposure was performed under the condition of pi resolution. Next, it was attached to a cylinder of a printing machine (Heidel SOR-KZ) without development processing, dampening water was supplied, ink was supplied, and paper was further supplied to perform printing. was gotten. The number of printable sheets was 11,000.

[Examples 10 to 12] A lithographic printing original plate was prepared in the same manner as in Example 9 except that the hydrophobic polymer used in the hydrophobic fine particles was changed as shown in Table 3 below. Printed and evaluated. The results are shown in Table 3.

[0164]

[Table 3]                                 Table 3 ──────────────────────────────────── Lithographic printing original plate Hydrophobic polymer (mass average molecular weight) ────────────────────────────────────   Example 9 11000 homopolymer of I-1 (25000)   Example 10 Copolymer CP1 (45000) 13,000 sheets   Example 11 1-5 homopolymer of I-5 (35000) 15,000 sheets   Example 12 Copolymer CP17 (40000) 12,000 sheets ────────────────────────────────────

[Example 13] (Preparation of fine particle dispersion of hydrophobic polymer) Homopolymer consisting of repeating unit (I-1) (mass average molecular weight: 2)
5000) 6 g, 4,4'-bismaleimidodiphenylmethane 1.2 g, infrared absorbing dye (IR-24) 1.5
g and anionic surfactant (Bionin A-41
0.1 g of C, manufactured by Takemoto Yushi Co., Ltd.) was dissolved in a mixed solvent of 7.4 g of methyl ethyl ketone and 13.7 g of ethyl acetate. The solution is changed to polyvinyl alcohol (PVA
205, 53 g of 1.8 mass% aqueous solution of Kuraray Co., Ltd.
And mix with a homogenizer at 15,000 rpm for 10
The mixture was stirred for a minute and emulsified. After stirring at 40 ° C. for 3 hours, methyl ethyl ketone and ethyl acetate were evaporated. The solid content concentration of the obtained hydrophobic polymer fine particle dispersion was 15.4% by mass. The average particle size of the fine particles was 0.30 μm.

(Formation of Image Forming Layer) An image forming layer coating liquid having the following composition was prepared.

[0167] ────────────────────────────────────   Composition of coating liquid for image forming layer ────────────────────────────────────   25 g of water   Hydrophobic polymer particle dispersion 20g ────────────────────────────────────

The coating solution for the image forming layer was applied on the undercoat layer of the aluminum support formed in Example 1 with a bar coater and dried in an oven at 60 ° C. for 120 seconds to form an image forming layer. The mass of the image forming layer after drying is 1.
It was 0 g / m ² . In this way, a lithographic printing original plate was produced.

(Plate making, printing and evaluation) An image setter (Trendsetter 3244VFS, made by Creo) in which a water-cooled 40 W infrared semiconductor laser is mounted on the prepared lithographic printing original plate.
At 9V output, 210 rpm outer drum speed,
Plate energy of 300 mJ / m ² and 2400 d
Image exposure was performed under the condition of pi resolution. Next, it was attached to a cylinder of a printing machine (Heidel SOR-KZ) without development processing, dampening water was supplied, ink was supplied, and paper was further supplied to perform printing. was gotten. The number of printable sheets was 20,000.

[Examples 14 to 16] Except that the hydrophobic polymer used in the hydrophobic fine particles and the compound having a plurality of dienophile structures were changed as shown in Table 4 below,
A lithographic printing plate precursor was prepared in the same manner as in Example 13, prepared, printed and evaluated. The results are shown in Table 4. The weight average molecular weight of the hydrophobic polymer is the same as in Table 3.

[0171]

[Table 4]                                 Table 4 ──────────────────────────────────── Printing original plate Polymer Compound with multiple dienophile structure ──────────────────────────────────── Example 13 I-1 4,4'-bismaleimidodiphenylmethane 20000 Example 14 CP1 Pentaerythritol tetraacrylate 21000 Example 15 I-5 Dipentaerythritol hexaacrylate 19000 Example 16 CP17 4,4'-Bismaleimidodiphenylmethane 23000 ────────────────────────────────────

[0172]

[Chemical 56]

[0173]

[Chemical 57]

Example 17 (Formation of Image Forming Layer) An image forming layer coating liquid having the following composition was prepared.

[0175] ────────────────────────────────────   Composition of coating liquid for image forming layer ────────────────────────────────────   Photothermal conversion dye (IR-25) 0.45g   Copolymer CP2 (molecular weight 30000) 2.5 g   Copolymer CP101 (Molecular weight 50000) 2.5 g   Fluorine-based surfactant (MegaFac F-176, Dainippon Ink and Chemicals, Inc.) Made) 0.05 g   Methyl ethyl ketone 24g   2-methoxy-1-propanol 24 g ────────────────────────────────────

[0176]

[Chemical 58]

The coating solution for image forming layer was applied on the undercoat layer of the aluminum support formed in Example 1 and dried at 70 ° C. for 5 minutes to form an image forming layer. The mass of the image forming layer after drying was 1.2 g / m ² . In this way, a lithographic printing original plate was produced.

(Plate making, printing and evaluation) The produced lithographic printing plate precursor was subjected to image exposure, development treatment and printing in the same manner as in Example 1, and evaluated by printing. As a result, good printed matter was obtained. The number of printable sheets was 23,000.

[Examples 18 to 21] A lithographic plate was prepared in the same manner as in Example 17 except that the benzocyclobutene polymer (CP2) and the dienophile polymer (CP101) used in Example 17 were changed as shown in Table 5 below. A printing original plate was manufactured, made into a plate, printed and evaluated. The results are shown in Table 5.

[0180]

[Table 5]                                 Table 5 ──────────────────────────────────── Printing original plate Benzocyclobutene polymer Dienophile polymer ──────────────────────────────────── Example 17 CP2 (molecular weight 30,000) CP101 (molecular weight 50,000) 23000 Example 18 CP9 (molecular weight 28,000) CP102 (molecular weight 70,000) 22000 Example 19 CP2 (molecular weight 30,000) CP104 (molecular weight 30,000) 20000 Example 20 CP17 (molecular weight 40,000) CP101 (molecular weight 50,000) 18,000 Example 21 CP1 (molecular weight 35,000) CP106 (molecular weight 37,000) 20000 ────────────────────────────────────

[0181]

[Chemical 59]

[0182]

[Chemical 60]

[0183]

[Chemical formula 61]

[0184]

According to the present invention, a lithographic printing plate having extremely high printing durability can be produced. That is, since the crosslinking reaction adopted in the present invention is hardly affected by the reaction inhibition by oxygen in the air, it is possible to form a crosslinking structure having an extremely high strength.

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) C08F 20/36 G03F 7/00 503 G03F 7/00 503 7/038 501 7/038 501 B41M 5/26 SF term ( (Reference) 2H025 AA12 AB03 AD01 BC52 BD40 CB08 CB41 CC11 2H096 AA06 AA25 BA06 2H111 HA01 HA14 HA22 HA35 2H114 AA04 AA22 AA23 AA24 BA01 BA10 DA56 DA60 DA61 EA01 EA02 P01P01P04P04P04P04P04P04P04P04P04P04P04P04P08P04P04P08P04P08P04P04P04P08P04P04P08P04P04P08P04P04P08P04P04P04P04P04P04P04P08P04P04P08P04P04P04P04P04P04P08P04P04P08P04P04P04P08P04P08P04P04P04P04P04P04P04P04P08P04P04P08P04P04P08P0408

Claims (6)

[Claims] 1. A step of image-wise heating an image-forming material in which an image-forming layer containing a polymer having an o-quinodimethane structure or a precursor structure thereof is provided on a support to cross-link the polymer, An image forming method comprising a step of removing a part of the image forming layer which is not heated and forming a replica image made of a crosslinked polymer. 2. A lithographic printing plate precursor on which an image forming layer containing a hydrophobic polymer having an o-quinodimethane structure or its precursor structure is provided on a hydrophilic support is imagewise heated to give a hydrophobic polymer. A method of making a lithographic printing plate comprising a step of cross-linking the image forming layer and a step of removing the image forming layer in the unheated portion. 3. A lithographic printing original plate having an image-forming layer on which a hydrophilic support is provided with an image forming layer containing fine particles of a hydrophobic polymer having an o-quinodimethane structure or a precursor structure thereof and a hydrophilic polymer. Step of cross-linking the hydrophobic polymer by heating to, the lithographic printing plate precursor is attached to the printing machine and the printing machine is operated, and the image forming layer in the unheated portion is removed by dampening water, ink, or rubbing. A lithographic printing method comprising the steps of making a lithographic printing plate thereby, and further supplying dampening water and an oil-based ink to perform printing with the lithographic printing plate made. 4. An image forming material comprising an image forming layer comprising a polymer having an o-quinodimethane structure or a precursor structure thereof on a support. 5. A lithographic printing original plate provided with an image forming layer containing a polymer having an o-quinodimethane structure or a precursor structure thereof on a hydrophilic support. 6. A lithographic printing original plate comprising a hydrophilic support and an image forming layer containing fine particles of a hydrophobic polymer having an o-quinodimethane structure or a precursor structure thereof and a hydrophilic polymer provided on the hydrophilic support.