JP2003285570A - Method for making lithographic printing plate and lithographic printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make up lithographic printing plate having resistance to plate wear by using an original plate of the printing plate having high sensitivity. <P>SOLUTION: The original plate of a lithographic printing plate has a support, a hydrophilic layer and an imaging layer formed in that order. The hydrophilic layer contains a hydrophilic polymer having a plurality of pieces of at least either of the structure of a diene or its precursor or the structure of a dienophile or its precursor. The imaging layer contains a chemical compound having a plurality of pieces of at least the other structure. In addition, the lithographic printing plate is manufactured through the step to heat the original plate of the lithographic printing plate in the shape of an image, and cause the polymer to chemically react with a chemical compound by the Diels-Alder reaction process to form a hydrophilic region and the step to remove the imaging layer. <P>COPYRIGHT: (C)2004,JPO

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 all the above requirements is
It was virtually impossible.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Japanese Patent No. 272 discloses a heat-sensitive lithographic printing original plate having a layer containing a polymer having a carboxyl group on a hydrophilic support. This original plate photothermally converts the light imagewise exposed in plate making, and decarboxylates the carboxyl groups by heat to form a hydrophobic region. Since the polymer having a carboxyl group in the unexposed portion remains hydrophilic, it can be developed with a fountain solution on the printing machine (no special development process is required).
However, the layer containing the polymer having a carboxyl group was merely coated on the hydrophilic support, and when printing a large number of sheets, the image part was peeled off and the printing durability was sometimes deteriorated. Further, when the amount of energy at the time of image recording is low, there is a problem of sensitivity that the change of the polymer to be hydrophobic is insufficient. An object of the present invention is to make a lithographic printing plate having printing durability using a lithographic printing original plate having high sensitivity.

[0006]

MEANS FOR SOLVING THE PROBLEMS The present invention includes a lithographic printing plate making method of the following (1), a lithographic printing method of the following (2), a lithographic printing original plate of the following (3) and (4) and the following (5). ) Provides a lithographic printing plate. (1) A support, a hydrophilic layer, and an image forming layer are provided in this order, and the hydrophilic layer has a plurality of structures of at least one of the structure of diene or its precursor and the structure of dienophile or its precursor. A lithographic printing plate precursor containing a hydrophilic polymer having an image forming layer containing at least a compound having a plurality of the other structures thereof is imagewise heated, and the polymer and the compound are reacted by a Diels-Alder reaction to obtain a hydrophobic property. A method of making a lithographic printing plate comprising a step of forming a region and a step of removing the image forming layer.

(11) The hydrophilic layer contains a hydrophilic polymer having a plurality of structures of dienophile or its precursor,
The plate-making method of a lithographic printing plate as described in (1), wherein the image forming layer contains a compound having a plurality of structures of a diene or a precursor thereof. (12) The plate-making method of a lithographic printing plate as described in (11), wherein the hydrophilic layer contains a hydrophilic polymer having a plurality of dienophile structures. (13) The method of making a lithographic printing plate according to (12), wherein the hydrophilic polymer is a copolymer containing a repeating unit having a dienophile structure and a repeating unit having a hydrophilic group. (14) The plate-making method for a lithographic printing plate as described in (1), wherein the support is made of a polymer film, and the polymer of the support and the hydrophilic polymer of the hydrophilic layer are covalently bonded. (15) The plate-making method of a lithographic printing plate as described in (14), wherein the polymer of the support is a trunk polymer and the hydrophilic polymer of the hydrophilic layer forms a graft polymer which is a branch polymer. (16) The plate-making method of a lithographic printing plate as described in (1), wherein the hydrophilic polymer has a crosslinked structure. (17) The method of making a lithographic printing plate as described in (1), wherein the structure of the diene is an o-quinodimethane structure. (18) The plate-making method for a lithographic printing plate as described in (11), wherein the image forming layer contains a compound having a plurality of diene precursor structures. (19) The plate-making method for a lithographic printing plate as described in (1), wherein the structure of the diene precursor is a benzocyclobutene ring. (20) The method of making a lithographic printing plate as described in (1), wherein the hydrophilic layer or the image forming layer further contains a photothermal conversion agent, and the lithographic printing plate precursor is imagewise heated by scanning with a laser beam.

(2) A support, a hydrophilic layer, and an image forming layer are provided in this order, and the hydrophilic layer has at least one of the structure of diene or its precursor and the structure of dienophile or its precursor. A lithographic printing plate precursor containing a hydrophilic polymer having a plurality of structures and an image forming layer containing at least a compound having a plurality of the other structures thereof is imagewise heated to react the polymer and the compound by a Diels-Alder reaction. A step of forming a hydrophobic area, a step of mounting the lithographic printing plate precursor on a printing machine and operating the printing machine, removing the image forming layer with dampening water, ink or rubbing, thereby making a lithographic printing plate A lithographic printing method further comprising the step of supplying dampening water and an oil-based ink and printing with a lithographic printing plate that has been made.

(21) The hydrophilic layer contains a hydrophilic polymer having a plurality of structures of dienophile or its precursor,
The lithographic printing method as described in (2), wherein the image forming layer contains a compound having a plurality of structures of a diene or a precursor thereof. (22) The lithographic printing method according to (21), wherein the hydrophilic layer contains a hydrophilic polymer having a plurality of dienophile structures. (23) The lithographic printing method as described in (22), wherein the hydrophilic polymer is a copolymer containing a repeating unit having a dienophile structure and a repeating unit having a hydrophilic group. (24) The lithographic printing method according to (2), wherein the support is made of a polymer film, and the polymer of the support and the hydrophilic polymer of the hydrophilic layer are covalently bonded. (25) The lithographic printing method according to (24), wherein the polymer of the support is a trunk polymer, and the hydrophilic polymer of the hydrophilic layer forms a graft polymer which is a branch polymer.

(26) The method of making a lithographic printing plate as described in (2), wherein the hydrophilic polymer has a crosslinked structure. (27) The lithographic printing method as described in (2), wherein the structure of the diene is an o-quinodimethane structure. (28) The lithographic printing method as described in (21), wherein the image forming layer contains a compound having a plurality of diene precursor structures. (29) The lithographic printing method as described in (2), wherein the structure of the diene precursor is a benzocyclobutene ring. (30) The lithographic printing method according to (2), wherein the hydrophilic layer or the image forming layer further contains a photothermal conversion agent, and the lithographic printing plate precursor is imagewise heated by scanning with a laser beam.

(3) A lithographic printing original plate having a support, a hydrophilic layer and an image forming layer in this order, wherein the hydrophilic layer has a structure of diene or its precursor and a structure of dienophile or its precursor. A lithographic printing original plate comprising a hydrophilic polymer having a plurality of structures of at least one of the above, and the image forming layer containing a compound having a plurality of at least the other structures thereof.

(31) The hydrophilic layer contains a hydrophilic polymer having a plurality of structures of dienophile or its precursor,
The lithographic printing plate precursor as described in (3), wherein the image forming layer contains a compound having a plurality of structures of a diene or a precursor thereof. (32) The lithographic printing original plate as described in (31), wherein the hydrophilic layer contains a hydrophilic polymer having a plurality of dienophile structures. (33) The lithographic printing plate precursor as described in (32), wherein the hydrophilic polymer is a copolymer containing a repeating unit having a dienophile structure and a repeating unit having a hydrophilic group. (34) The lithographic printing original plate as described in (3), wherein the support is made of a polymer film, and the polymer of the support and the hydrophilic polymer of the hydrophilic layer are covalently bonded. (35) The lithographic printing original plate as described in (34), wherein the polymer of the support is a trunk polymer and the hydrophilic polymer of the hydrophilic layer forms a graft polymer which is a branch polymer.

(36) The lithographic printing original plate as described in (1), wherein the hydrophilic polymer has a crosslinked structure. (37) The lithographic printing original plate as described in (3), wherein the diene structure is an o-quinodimethane structure. (38) The lithographic printing original plate as described in (31), wherein the image forming layer contains a compound having a plurality of diene precursor structures. (39) The lithographic printing plate precursor as described in (3), wherein the structure of the diene precursor is a benzocyclobutene ring. (4) A support, a hydrophilic layer, and an image forming layer are provided in this order, and the hydrophilic layer has a plurality of structures of at least one of the structure of diene or its precursor and the structure of dienophile or its precursor. A lithographic printing original plate comprising a hydrophilic polymer having an image forming layer, and the image forming layer containing a compound having at least a plurality of the other structures in the form of fine particles.

(5) A lithographic printing plate having a hydrophilic region and a hydrophobic region formed on a support, wherein the hydrophilic region is formed of a hydrophilic polymer and the hydrophobic region is interposed by a cyclohexene ring. A lithographic printing plate characterized by being formed from a hydrophobic polymer which has been crosslinked. (51) The lithographic printing original plate as described in (5), wherein the support is made of a polymer film, and the support polymer, the hydrophilic polymer in the hydrophilic region and the hydrophobic polymer in the hydrophobic region are covalently bonded. (52) The lithographic printing plate precursor as described in (51), wherein the support polymer is a trunk polymer, and the hydrophilic polymer in the hydrophilic region and the hydrophobic polymer in the hydrophobic region form a graft polymer which is a branch polymer. .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION [Basic Structure of Lithographic Printing Plate] The lithographic printing plate has a support, a hydrophilic layer, and an image forming layer in this order. The hydrophilic layer contains a hydrophilic polymer having a plurality of structures of at least one of the structure of diene or its precursor and the structure of dienophile or its precursor. Then, the image forming layer contains at least a compound having a plurality of the other structures. That is, when the hydrophilic polymer has a plurality of structures of diene or its precursor, the compound of the image forming layer has a plurality of structures of dienophile or its precursor. When the hydrophilic polymer has a plurality of structures of dienophile or its precursor, the compound of the image forming layer has a plurality of structures of diene or its precursor. When the hydrophilic polymer has both a structure of diene or its precursor and a structure of dienophile or its precursor, the compound of the image forming layer is composed of dienophile or its precursor and the structure of dienophile or its precursor. It suffices to have a plurality of either one. When the compound of the image-forming layer has a plurality of both the structure of diene or its precursor and the structure of dienophile or its precursor, the hydrophilic polymer is composed of dienophile or its precursor and the structure of dienophile or its precursor. It suffices to have a plurality of either one.

It is particularly preferred that the hydrophilic layer comprises a hydrophilic polymer having a plurality of structures of dienophile or its precursor, and the imaging layer comprises a compound having a plurality of structures of diene or its precursor. In the present invention, the dienophile structure and the diene structure are combined with Diels-Alder (Diels-
Alder) react. In the Diels-Alder reaction,
As shown below, a compound in which two diene structures (hereinafter, an o-quinodimethane structure of a) bond two dienophile structures (hereinafter, two vinyl groups) with a divalent linking group (L) ( It reacts with b) to form two cyclohexene rings to form a linkage (c) and thus bond.

[0017]

[Chemical 1]

[Support] As the support, paper, synthetic paper,
Polymer films, metal plates and combinations of these materials can be used (eg, polymer laminated paper, metal laminated paper or polymer film, metal vapor deposited paper or polymer film). Metal plates, composites thereof, polymer films and composites thereof are preferred.

The metal plate is preferably an 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. The different elements of the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of foreign elements in the alloy is generally 10 mass% or less. Since completely pure aluminum is difficult to produce due to refining technology, an aluminum alloy containing slightly different elements is preferable. The thickness of the aluminum plate is preferably 0.1 to 0.6 mm,
0.15 to 0.4 mm is more preferable, and 0.2 to 0.8 mm is the most preferable.

Examples of polymers constituting the polymer film include polyethylene, polypropylene, polystyrene,
Polyester (eg, polyethylene terephthalate, polyethylene naphthalate, polycarbonate), polyimide, polyamide, polyurethane, polyvinyl acetal and cellulose ester (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose) Nitrate) is included. Polyester is especially preferred. You may use together 2 or more types of polymers. You may laminate | stack and use two or more polymer films. A composite material in which a polymer film and another material are combined can also be preferably used as the support. Other materials include paper, synthetic paper and metal (eg aluminum, zinc, iron, copper) plates. Paper, synthetic paper and metal plate can be used by laminating them with a polymer film. Alternatively, a composite material in which a metal is deposited on a polymer film may be used. When the polymer film and other materials are combined, an image forming layer is provided on the polymer film side. The thickness of the polymer film support is preferably 10 μm to 5 mm, more preferably 50 to 500 μm.

In order to obtain the same effect as the graining treatment (increase in water retention amount) on the aluminum support, it is possible to form an uneven structure on the surface of the polymer film. As the roughness of the support surface obtained by the uneven structure, the center line average roughness (Ra: measured length (L) portion from the roughness curve in the direction of the center line) of the two-dimensional roughness parameter is extracted, and this The value obtained by arithmetically averaging the absolute value of the deviation between the center line and the roughness curve) is preferably 0.1 to 1 μm.
Maximum height (Ry: A value measured by extracting a reference length from the roughness curve in the direction of the average line and measuring the distance between the peak line and the valley bottom line of this extracted portion in the direction of the vertical magnification of the roughness curve)
Is preferably 1 to 10 μm. Ten-point average roughness (Rz: The standard length was extracted from the roughness curve in the direction of the average value, and the elevation of the fifth summit from the highest summit (measured in the direction of longitudinal magnification from the average line of this extracted portion ( Yp) average of absolute values and sum of average absolute values of elevations (Yv) of the lowest to fifth valley bottoms)
Is preferably 1 to 10 μm. Average interval of local peaks (S: Sampling only a reference length from the roughness curve in the direction of the average line, and finding the length of the average line corresponding to the adjacent local peaks in this sampling portion. The arithmetic mean value of the intervals) is preferably 5 to 80 μm. The maximum height (Rt: the value of the interval between two straight lines when sandwiching the extracted part between two straight lines parallel to the center line of the part extracted by the reference length from the roughness curve) is 1 to 10
It is preferably μm. The center line peak height (Rp: the value of the distance from the roughness curve to a straight line passing through the highest peak parallel to the center line of the sampled portion by extracting the portion of the measurement length (L) in the direction of the centerline), It is preferably 1 to 10 μm. The center line valley depth (Rv: the value of the distance from the roughness curve to the straight line that passes through the deepest valley bottom parallel to the center line of this extracted portion by extracting the portion of the measurement length (L) in the direction of the center line) It is preferably 1 to 10 μm.

Various means can be used to form the textured structure on the polymer film surface. For example, the polymer film surface can be mechanically rubbed (for example, by sandblasting or brushing), and the surface can be scraped to form a rough surface. In addition, unevenness can be provided by mechanical embossing. Further, by printing resin (for example, gravure printing), the convex portion can be formed on the surface. Solid particles (matting agent) may be added to the hydrophilic layer described below to provide a rough surface. Even when the solid fine particles are internally added to the polymer film, irregularities can be formed on the surface of the polymer film. Various surface treatments (eg solvent treatment, corona discharge treatment,
A rough surface can be formed even by performing plasma discharge treatment, electron beam irradiation treatment, X-ray irradiation treatment. You may implement combining the above means.

[Hydrophilic layer] The hydrophilic layer contains a hydrophilic polymer. The hydrophilic polymer has a plurality of structures of at least one of the structure of diene or its precursor and the structure of dienophile or its precursor. As described above, the hydrophilic polymer preferably has a plurality of structures of dienophile or its precursor. Since dienophile is easy to synthesize, it is preferable to introduce the structure of dienophile itself rather than the precursor structure. The dienophile structure is generally synonymous with the unsaturated bond defined in the Diels-Alder reaction. That is, if it is an unsaturated bond that reacts with a diene to cause a Diels-Alder reaction, not only a carbon-carbon double bond (> C = C <) and a carbon-carbon triple bond (-C≡C-), Carbonyl group (> C = O), nitroso group (-N = O), azo bond (-
Unsaturated bonds involving atoms other than carbon such as N = N-) are also included. However, carbon-carbon double bond (> C = C
<) Is the most preferable.

The dienophile structure is preferably contained in the side chain of the hydrophilic polymer. The main chain of the hydrophilic polymer 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 hydrophilic polymer has a hydrophilic group in addition to the side chain containing the dienophile structure. Examples of hydrophilic groups include hydroxyl, mercapto, carboxyl, sulfo, sulfate group, phosphono, a phosphoric acid ester group, ammonio, -N ⁺ H ₂ -
R, -N ⁺ H (-R) ₂ and -N ⁺ (-R) ₃ are included. The R's are each an aliphatic group, an aromatic group or a heterocyclic group. Carboxyl, sulfo, sulfate group, phosphono, phosphate group, ammonio, -N ^{+
_{H 2 -R, -N + H (}} -R) 2 and -N ⁺ (-R) ₃
May have a hydrogen atom or a proton dissociated or may be in a salt state. Also, a group containing a large number of ether bonds such as a polyoxyalkylene group (eg, polyoxyethylene) can be made to function as a hydrophilic group. Further, a divalent linking group such as an ester bond or an amide bond can be made to function as a hydrophilic group.

The main chain of the hydrophilic polymer may have a substituent in addition to the side chain containing the dienophile structure and the hydrophilic group. Examples of other substituents include halogen atoms (F, C
l, Br, I), cyano, aliphatic group, aromatic group, heterocyclic group, -OR, -SR, -CO-R, -NH-R,-.
N (-R) ₂ , -CO-O-R, -O-CO-R, -C
O-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. 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 hydrophilic polymer preferably has a repeating unit containing a dienophile structure represented by the following formula (I) in the side chain.

[0027]

[Chemical 2]

In the formula (I), Di is a dienophile structure. 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 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. An example of L ¹ is shown below. 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.

[0030] L0: Single bond L1: -O- L2: -CO-O- L3: -CO-O-AL- L4: -CO-O-AL-O- L5: -CO-O-AL-O-CO- L6: -CO-NH- L7: -CO-NH-AL-O- L8: -CO-NH-AL-NH-

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

[0032]

[Chemical 3]

[0033]

[Chemical 4]

[0034]

[Chemical 5]

[0035]

[Chemical 6]

[0036]

[Chemical 7]

[0037]

[Chemical 8]

[0038]

[Chemical 9]

[0039]

[Chemical 10]

[0040]

[Chemical 11]

The hydrophilic polymer is particularly preferably a copolymer containing a repeating unit having a dienophile structure and a repeating unit having a hydrophilic group. The hydrophilic group is as described above.

Examples of hydrophilic monomers for forming a repeating unit having a hydrophilic group include acrylic acid, methacrylic acid, itaconic acid, acrylic acid ester (eg, 2-hydroxyethyl acrylate), and methacrylic acid ester (eg. , 2-hydroxyethyl methacrylate), acrylamide, methacrylamide, N-substituted acrylamide (eg, N-methylolacrylamide, N, N-dimethylolacrylamide), N-substituted methacrylamide (eg, N-methylolmethacrylamide, N, N-dimethylol methacrylamide), allylamine, 2-vinylpropionic acid, vinylsulfonic acid, vinylstyrenesulfonic acid, 2-sulfoethylene acrylate, 2-sulfoethylene methacrylate, 3-sulfopropylene acrylate, 3-sulfo B pyrene methacrylate, polyoxyethylene monoacrylate, polyoxyethylene monomethacrylate, 2-acrylamido-2-methylpropanesulfonic acid, acidphosphoxyethyl polyoxyethylene monoacrylate and acidphosphoxyethyl polyoxyethylene monomethacrylate. Acids such as acrylic acid may form salts with cations (eg, alkali metal ions, organic substituted ammonium ions). A base such as allylamine may form a salt with an anion (eg, hydrohalide ion). The repeating unit having a hydrophilic group is particularly preferably a repeating unit derived from the following acrylic acid or methacrylic acid. The carboxyl group may have a hydrogen atom dissociated or may be in a salt state.

[0043]

[Chemical 12]

The hydrophilic polymer may contain other repeating units in addition to the repeating unit having a dienophile structure and the repeating unit having a hydrophilic group. Examples of other repeating units are shown below.

[0045]

[Chemical 13]

[0046]

[Chemical 14]

[0047]

[Chemical 15]

A repeating unit containing a dienophile structure,
When a repeating unit having a hydrophilic group and another repeating unit are combined to form a copolymer, the proportion of the repeating unit containing a dienophile structure is preferably 1 to 50 mol%, and 5 to 20 mol%. Is more preferable. It is preferable to introduce a crosslinked structure into the hydrophilic polymer or (when the support is a polymer film) covalently bond to the polymer of the support.

The crosslinked structure can be introduced into the hydrophilic polymer by using a crosslinking agent. A coupling agent can be used as the cross-linking agent. Silane coupling agents are particularly preferred. By reacting the hydrophilic group of the hydrophilic polymer with the coupling agent, a crosslinked structure can be introduced into the hydrophilic polymer. A crosslinked hydrophilic layer composed of a condensate of a hydrophilic polymer and a silane coupling agent is described in Japanese Patent No. 2592225. It is also possible to introduce an ethylenically unsaturated group (eg, vinyl, allyl, acryloyl, methacryloyl, cinnamoyl, cinnamylidene, cyanocinnamylidene, diacryloylphenyl) into the hydrophilic polymer, and crosslink by reaction of the unsaturated group. . The ethylenically unsaturated group may be introduced at the monomer stage of the hydrophilic polymer.
An isocyanate compound or its precursor (block polyisocyanate compound) can be used as a cross-linking agent to react the cross-linking agent with the hydrophilic group of the hydrophilic polymer.

It is also possible to introduce a glycidyl group into the hydrophilic polymer and carry out a ring-opening reaction of the glycidyl group using a crosslinking agent to form a crosslinked structure. Examples of the glycidyl group crosslinking agent include polyvalent carboxylic acids (eg, 1,2-ethanedicarboxylic acid, adipic acid, 1,2,3-propanetricarboxylic acid, trimellitic acid), polyamines (eg, 1,2). -Ethanediamine, diethylenediamine, diethylenetriamine, α, ω-bis (3-aminopropyl) polyethylene glycol ether) and polyhydric alcohols (eg ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, trimethylolpropane, glycerin, penta) Eristol and sorbitol) are included. Polyepoxy compounds can also be used as crosslinking agents. Examples of polyepoxy compounds include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether and triglyceride. Includes methylolpropane triglycidyl ether.

When the hydrophilic polymer is covalently bonded to the support polymer, the covalent bond introduces a crosslinked structure between the two polymers, or one polymer is a trunk polymer and the other polymer is a branch polymer. A graft copolymer may be formed. Alternatively, the hydrophilic polymer may be formed as a graft polymer, and the graft polymer and the polymer of the polymer film support may be covalently bonded (for example, by a coupling reaction). A method of forming a graft copolymer is preferable, and a method of forming a graft copolymer in which the polymer of the polymer film support is a trunk polymer and the hydrophilic polymer of the hydrophilic layer is a branch polymer is particularly preferable.

In the graft polymerization, an active species is generated in the trunk polymer, polymerization of another monomer is initiated from this active species, and a branch polymer is grafted (grafted). Graft polymerization is possible even when the trunk polymer forms a solid surface such as a polymer film (surface graft polymerization method). To generate active species in the trunk polymer, light irradiation,
There are means such as plasma irradiation and radiation irradiation (eg, γ-ray, electron beam). For light irradiation and plasma irradiation, New Polymer Experiments 10, edited by Japan Society of Polymer Science, 1994,
It is described on page 135 of Kyoritsu Shuppan Co., Ltd. Regarding light irradiation, JP-A-63-92658 and JP-A-10-2
It is also described in each publication of 96895 and 11-1194413. Regarding the radiation irradiation, it is described in Absorption Technology Handbook, February 1999, published by NTS Corporation, pages 203 and 695. For the graft polymerization method,
Other references (eg Y. Ikeda et al, Macromolecul
es vol. 19, page 1804 (1986)). Reactive functional groups (eg, trialkoxysilyl groups, isocyanate groups, amino, hydroxyl, carboxyl) may be directly attached to the trunk polymer as active species. The reactive functional group can be introduced into the trunk polymer by a coupling reaction. The hydrophilic layer is preferably formed in the range of 0.001 to 10 g / m ² , and more preferably 0.01 to 5 g / m ² .

[Image Forming Layer] The image forming layer contains a compound having a plurality of structures of at least one of the structure of diene or its precursor and the structure of dienophile or its precursor. The specific structure is determined in relation to the hydrophilic polymer of the hydrophilic layer, as described above. As described above, the compound contained in the image forming layer preferably has a plurality of structures of diene or its precursor. Since the diene is relatively unstable, it is preferable to introduce the precursor structure of the diene rather than the structure of the diene itself. The diene structure is preferably an o-quinodimethane structure. o-
The quinodimethane structure can be defined by the following formula.

[0054]

[Chemical 16]

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 compound. The precursor structure is a structure capable of forming an o-quinodimethane structure by some reaction. In the plate making of a lithographic printing plate, a hydrophilic polymer is crosslinked by heating, and therefore 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.

[0056]

[Chemical 17]

A compound having a plurality of benzocyclobutene structures as a precursor structure of an o-quinodimethane structure is particularly preferable. The compound having a plurality of benzocyclobutene structures is preferably represented by the following formula (IV).

[0058]

[Chemical 18]

In the formula (IV), R²Is benzocyclo
It is a butene ring substituent, and m 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. The substituent on the benzocyclobutene ring is a halogen atom,
Amino, aliphatic group, aromatic group, -OR, -SR,-
CO-R, -NH-R, -N (-R)₂, -CO-O-
R, -CO-NH-R and -NH-CO-R are preferred
Yes.

The aliphatic group may have a cyclic structure or a branched structure. Another aliphatic ring, aromatic ring or heterocyclic ring may be condensed with the cyclic aliphatic group. The number of carbon atoms in the aliphatic group is preferably 1 to 40, more preferably 1 to 30, still more preferably 1 to 20, still more preferably 1 to 15 Most preferably, it is from 12 to 12. The aliphatic group may have a substituent. Examples of the substituent of the aliphatic group include halogen atom (F, Cl, Br, I), amino, hydroxyl, mercapto, carboxyl, sulfo, sulfate group, phosphono, phosphate group, cyano, aromatic group, Heterocyclic group, -OR, -SR, -C
OR, -NH-R, -N (-R) ₂ , -N ⁺ (-R)
₃ , -CO-OR, -O-CO-R, -CO-NH-
R, -NH-CO-R and -P (= O) (-OR)
Includes ₂ . 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 monovalent 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.

An aliphatic ring or a heterocyclic ring may be condensed with the aromatic group. The aromatic group may have a substituent. Examples of the substituent of the aromatic group include a halogen atom (F, C
l, Br, I), amino, 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. The monovalent aromatic group is
It means an aryl group or a substituted aryl group. 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 oxo (═O) in addition to the examples of the substituent of the aromatic group.

In the formula (IV), 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, a divalent or trivalent aliphatic group,
An n-valent organic residue selected from a divalent or trivalent aromatic group, a divalent or trivalent heterocyclic group, -O-, -CO-, -NH-, -N <and combinations thereof. Is more preferable. The moiety in which L ² is bonded to the benzocyclobutene ring is preferably —O—, —CO—, —NH— or a divalent aliphatic group, more preferably —O— or —CO—. , -O- is most preferable. It is particularly preferred that L ² be bonded to the 4-membered ring carbon atom of the benzocyclobutene ring. Below, the example of the compound represented by Formula (IV) is shown.

[0063]

[Chemical 19]

[0064]

[Chemical 20]

[0065]

[Chemical 21]

[0066]

[Chemical formula 22]

[0067]

[Chemical formula 23]

[0068]

[Chemical formula 24]

[0069]

[Chemical 25]

[0070]

[Chemical formula 26]

[0071]

[Chemical 27]

[Synthesis Example 1] (Synthesis of Compound IV-1) Under a nitrogen stream, 150 ml of ethylene glycol was added dropwise to 56.1 g of potassium t-butoxide and completely dissolved. Then, in this solution,
45.3 g of 1-bromobenzocyclobutene synthesized according to the method of DeCamp et al (J. Org. Chem., 1981, 46, 3918) was added dropwise, and after completion of the addition, the temperature was raised to 80 ° C. and the mixture was stirred for 7 hours. .
After cooling to room temperature, pour into ice water and p.
H was set to 6, and the organic matter was extracted with ethyl acetate. After the solvent was distilled off, the residue was purified by silica gel column chromatography, and 20.6 g of 1- (2'-hydroxyethoxy)-
Benzocyclobutene was obtained. 6.56 g of the obtained 1- (2'-hydroxyethoxy) -benzocyclobutene,
Triethylamine 4.44 g was added to tetrahydrofuran 30
It was dissolved in ml and cooled to 0 ° C. To this solution, 3.1 g of succinic acid chloride was added dropwise. After the dropping was completed, the temperature was raised to room temperature, the mixture was stirred for 4 hours, poured into ice water, and the organic matter was extracted with ethyl acetate. After the solvent was distilled off, the residue was purified by silica gel column chromatography to obtain 6.8 g of compound IV-1.

[Synthesis Example 2] (Synthesis of Compound IV-2) In the same manner as in Synthesis Example 1, except that 3.1 g of succinic acid chloride was changed to 3.1 g of fumaric acid chloride in Synthesis Example 1, 5 .6g of compound IV-
Got 2.

[Synthesis Example 3] (Synthesis of Compound IV-3) The same procedure as in Synthesis Example 1 was repeated except that 3.1 g of succinic acid chloride was changed to 3.66 g of adipic acid chloride in Synthesis Example 1. 0.5 g of compound
IV-3 was obtained.

[Synthesis Example 4] (Synthesis of Compound IV-7) In Synthesis Example 1, 1- (2 ′)
-Hydroxyethoxy) -benzocyclobutene 6.56
g was changed to 5.41 g, succinic acid chloride 3.1 g was changed to trimesic acid chloride 2.65 g, and the amount of triethylamine was changed from 4.44 g to 3.33 g.
Similarly to the above, 5.8 g of Compound IV-7 was obtained.

Other compounds can be synthesized in the same manner as in each synthesis example. A compound having a plurality of o-quinodimethane structures or a precursor structure thereof is added to the image forming layer in an amount of 5 to 90.
It is preferably contained by mass%, more preferably 30 to 80% by mass.

[Fine Particles] Fine particles containing a plurality of compounds having an o-quinodimethane structure or a precursor structure thereof can be dispersed in the image forming layer. 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. The fine particles preferably have a particle size of 10 to 1000 nm, more preferably 50 to 500 nm. The particle size distribution is preferably as uniform as possible. Two or more kinds of fine particles may be mixed and used.

Microcapsules containing compounds having a plurality of o-quinodimethane structures or precursor structures thereof can also be used as fine particles. Microcapsules
Known coacervation method (US Pat. No. 2,800,457)
Nos. 2800458), interfacial polymerization method (British Patent 990443, US Patent 3287154, Japanese Patent Publication Nos. 38-19574, 42-44).
No. 6, No. 42-711), polymer precipitation method (U.S. Pat. Nos. 3,418,250 and 3,660,304), isocyanate / polyol wall forming method (U.S. Pat. No. 3,796,669), isocyanate Wall forming method (described in US Pat. No. 3,914,511), urea / formaldehyde wall or urea / formaldehyde-resorcinol wall forming method (US Pat. No. 400)
1140, 4087376, and 4089802), melamine-formaldehyde wall or hydroxycellulose wall forming method (US Pat. No. 4025).
No. 445), an in situ method by monomer polymerization (described in Japanese Patent Publication Nos. 36-9163 and 51-9079), and a spray drying method (UK patent 9304).
22, each specification of US Pat. No. 3,111,407),
Alternatively, it can be produced by the electrolytic dispersion cooling method (described in the respective specifications of British Patent Nos. 952807 and 967074).

The microcapsule wall has three-dimensional crosslinking and may be swollen by a solvent. As the wall material of the microcapsules, it is preferable to use polyurea, polyurethane, polyester, polycarbonate, polyamide and a mixture thereof. Polyurea and polyurethane are particularly preferred. The above hydrophobic polymer may be used for the microcapsule wall. The average particle size of the microcapsules is preferably 0.01 to 20 μm, more preferably 0.05 to 2.0 μm, and 0.10 to 1.0 μm.
m is most preferred. As for the microcapsules, the capsules may be fused by heat. That is, among the microcapsule inclusions, those that exude outside the microcapsules at the time of heating, or those that penetrate 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 in terms of solid content.
%, And more preferably 15 to 40% by weight.
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.

[Photothermal Conversion Agent] The hydrophilic layer or the image forming layer preferably contains a photothermal conversion agent. The image forming layer is
It is more preferable to include 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 is
It can be present inside the hydrophobic polymer particles. Photothermal conversion agent outside of fine particles (in hydrophilic binder)
May be added to. The wavelength of light absorbed by the photothermal conversion agent (maximum absorption wavelength) is particularly preferably 700 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.

For infrared absorbing pigments, the 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.

For 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, 4283475, JP-A-57 / 1982
-142645, 58-181051, 58-
220143, 59-41363, 59-84
No. 248, No. 59-84249, No. 59-14606.
No. 3, No. 59-146061, No. 5-13514
Nos. 5-19702), carbonium dyes, quinoneimine dyes and methine dyes (JP-A-58).
-173696, 58-181690, 58-
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 dye, L
e 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.

[0086]

[Chemical 28]

[0087]

[Chemical 29]

[0088]

[Chemical 30]

[0089]

[Chemical 31]

[0090]

[Chemical 32]

[0091]

[Chemical 33]

When the infrared absorbing dye is added to 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.

[0093]

[Chemical 34]

[0094]

[Chemical 35]

[0095]

[Chemical 36]

[0096]

[Chemical 37]

Metals generally have 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] A colorant may be added to the hydrophilic layer or 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.

In order to extend the stability of on-press development, the hydrophilic layer or the image-forming layer contains a nonionic surfactant (Japanese Patent Laid-Open Publication No.
2-251740, JP-A-3-208514) or amphoteric surfactant (JP-A-59-1210).
No. 44, each of the descriptions in JP-A-4-13149) can be added. Examples of nonionic surfactants include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride and polyoxyethylene nonyl phenyl ether. Examples of amphoteric surfactants are alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N.
-Hydroxyethyl imidazolinium betaine and N
-Tetradecyl-N, N-betaine type surfactant (Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.) is included. The nonionic surfactant and the amphoteric surfactant are contained in the image forming layer in an amount of 0.0
The content is preferably 5 to 15% by mass, and more preferably 0.1 to 5% by mass.

A plasticizer may be added to impart flexibility to the hydrophilic layer or the image forming layer. Examples of plasticizers include
Polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate,
Included are 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 may be added to the coating liquid to improve the coating property. 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 .

[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-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 the 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 diene structure and the dienophile structure undergo a Diels-Alder reaction to form a hydrophobic region. On the other hand, there is no change in the non-heated portion (non-image portion) of the lithographic printing original plate.

[Plate-making process and printing process] The lithographic printing plate precursor image-wise heated can be developed to develop a lithographic printing plate. The image forming layer is a coating layer and can be easily removed. Further, even if the treatment for removing the image forming layer (development treatment) is not carried out, the planographic printing original plate which is imagewise heated is immediately mounted on the printing machine, and printing is carried out by a usual procedure using ink and fountain solution. Only by itself, plate making and printing can be continuously performed. That is, when the lithographic printing plate precursor is mounted on a printing machine and the printing machine is operated, the image forming layer can be removed by dampening water, ink, or rubbing. A printing machine having a laser exposure device (Japanese Patent No. 29383)
No. 98), after the lithographic printing plate precursor is mounted on the cylinder of the printing machine, it is exposed by a laser mounted on the printing machine, and then fountain solution or ink is applied to develop it on the machine (exposure- It is also possible to process printing continuously). Further, it is also possible to further heat the entire surface of the printing plate thus prepared to react the unreacted diene structure and the dienophile structure remaining in the image area to further improve the strength (printing durability) of the printing plate.

[0109]

[Example 1] (Preparation of polymer film support) A biaxially stretched polyethylene terephthalate film (A4100, manufactured by Toyobo Co., Ltd.) having a film thickness of 188 µm was used as a support surface layer (also used as a support). As a glow process, a planographic magnetron sputtering device (Shibaura Eletech's CFS ・ 10 ・ EP7
0) was used and oxygen glow treatment was performed under the following conditions (initial vacuum: 9 × 10 ⁻⁶ torr, oxygen pressure: 6.8 × 10).
^-3 torr, RF glow: 1.5KW, processing time: 60
Seconds).

(Formation of hydrophilic layer) Acrylic acid was mixed with the following dienophile monomer in an amount of 10 mol% with respect to acrylic acid, and the mixture was dissolved in a mixed solvent (water / methanol = 1/1 volume ratio) to obtain 10 A mass% solution was prepared.

[0111]

[Chemical 38]

The solution was degassed by bubbling with nitrogen, and then the glow-treated polymer film support was immersed at 70 ° C. for 7 hours. The infiltrated membrane was washed with water for 8 hours to copolymerize acrylic acid and a dienophile monomer to form a graft-polymerized hydrophilic layer on the surface of the support. The contact angle of water droplets in the air of the obtained hydrophilic layer was measured by a measuring machine (CA-Z, manufactured by Kyowa Interface Science Co., Ltd.) and found to be 14 °.

(Formation of Image Forming Layer) A composition having the following formulation was applied onto the hydrophilic layer to form an image forming layer. In this way, a negative type lithographic printing original plate was produced.

[0114] ────────────────────────────────────   Composition of coating liquid for image forming layer ────────────────────────────────────   Carbon black dispersion 2.4g   Compound (IV-1) having a plurality of benzocyclobutene structures 2.5 g   Polymethyl methacrylate (mass average molecular weight: 10,000) 2.5g   Fluorine-based surfactant (MegaFac F-176, Dainippon Ink and Chemicals, Inc.) Made of) 20 mass% aqueous solution 0.05 g   Methyl ethyl ketone 24g   2-methoxy-1-propanol 24 g ────────────────────────────────────

(Plate making, printing, evaluation) The obtained negative type lithographic printing plate precursor was used at a linear velocity of 8 m / sec using a semiconductor laser (wavelength 825 nm, beam diameter: 1 / e 2 = 6 μm) as a heat mode laser. The plate surface output was adjusted to 110 mW and exposed. After exposure, printing machine (Heidel KOR-D
Machine) and printed. As a result, 9000 good prints with no stain on the non-image area were obtained. Next, this lithographic printing plate precursor was stored at 45 ° C. and a relative humidity of 75% and subjected to the same treatment, and similarly, a good printed matter having no stain on the non-image area was obtained. The number of prints obtained was 9000.

[Examples 2 to 4] A lithographic printing plate precursor was prepared in the same manner as in Example 1 except that the compound having a benzocyclobutene structure added to the coating liquid for the image forming layer was changed as shown in Table 1 below. It was produced, plate-made, and printed for evaluation. The results are shown in Table 1.

[0117]

[Table 1]                                 Table 1 ──────────────────────────────────── Lithographic printing original plate Benzocyclobutene compound ────────────────────────────────────   Example 1 (IV-1) 8000 sheets   Example 2 (IV-3) 10,000 sheets   Example 3 (IV-7) 9,000 sheets   Example 4 (IV-13) 8000 sheets ────────────────────────────────────

Example 5 (Preparation of Fine Particle Dispersion) 2 g of compound (IV-1) having plural benzocyclobutene structures, infrared absorbing dye (IR
-28) 1.5 g, polymethyl methacrylate (mass average molecular weight: 10,000) 2 g and anionic surfactant (Bionin A-41C, manufactured by Takemoto Yushi Co., Ltd.) 0.1 g, methyl ethyl ketone 7.4 g and acetic acid. 13.7 g of ethyl
Was dissolved in a mixed solvent consisting of The solution was mixed with 53 g of a 1.8 mass% aqueous solution of polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.), and the mixture was homogenized at 15000.
The mixture was stirred at rpm for 10 minutes and emulsified. 40 ° C
Stir at 3 h and evaporate methyl ethyl ketone and ethyl acetate. The solid content concentration of the obtained fine particle dispersion was 15.4 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.

[0120] ────────────────────────────────────   Composition of coating liquid for image forming layer ────────────────────────────────────   25 g of water   Fine particle dispersion 20g ────────────────────────────────────

The coating liquid for the image forming layer was applied on the hydrophilic layer formed in Example 1 by a bar coater and then heated in an oven at 60.
An image forming layer was formed by drying at 120 ° C. for 120 seconds. The mass of the image forming layer after drying was 1.0 g / m ² .
In this way, a lithographic printing original plate was produced.

(Plate making, printing, evaluation) The lithographic printing plate precursor thus prepared was subjected to the same exposure and printability evaluation as in Example 1. The results are shown in Table 2.

[Examples 6 to 8] Compounds having a plurality of benzocyclobutene structures added to the coating solution for the image forming layer were prepared by
A lithographic printing plate precursor was prepared in the same manner as in Example 5 except that the changes were made as shown in Table 2 below. The results are shown in Table 2.

[0124]

[Table 2]                                 Table 2 ──────────────────────────────────── Lithographic printing original plate Benzocyclobutene compound ────────────────────────────────────   Example 5 (IV-1) 8000 sheets   Example 6 (IV-3) 8500 sheets   Example 7 (IV-7) 7500 sheets   Example 8 (IV-8) 9000 sheets ────────────────────────────────────

Examples 9 to 12 (Production of Aluminum Support) An aluminum plate having a thickness of 200 μm was used as a support.

(Synthesis of Hydrophilic Polymer) Acrylic acid and the dienophile monomer used in Example 1 were copolymerized at a copolymerization molar ratio of 9: 1 to synthesize a copolymer having a mass average molecular weight of 30,000. 18.0 g of the copolymer was dissolved in dimethylacetamide and 5.5 g of 2-methacryloyloxyethyl isocyanate and dibutyltin dilaurate of 0.5 g were dissolved.
1 g was added and reacted for 3 hours. Next, 80 equivalent% of the carboxyl group was partially neutralized with sodium hydroxide, acetone was added to precipitate the polymer, which was thoroughly washed and purified to synthesize a hydrophilic polymer.

(Formation of Hydrophilic Layer) Hydrophilic Polymer 1.
0 g and 0.2 g of trimethyloltriazine were dissolved in 20 g of water. Next, this solution was applied onto an aluminum support using a wire bar and dried at 120 ° C. for 1 hour to obtain a crosslinked hydrophilic layer. The thickness of the hydrophilic layer is 3.5
was μm.

(Formation of image forming layer) An image forming layer was formed on the hydrophilic layer in the same manner as in Examples 1 to 4 to prepare a lithographic printing original plate.

(Plate making, printing, evaluation) The lithographic printing plate precursor thus produced was subjected to the same exposure and printability evaluation as in Example 1. The results are shown in Table 3.

[0130]

[Table 3]                                 Table 3 ──────────────────────────────────── Lithographic printing original plate Benzocyclobutene compound ────────────────────────────────────   Example 9 (IV-1) 7,000 sheets   Example 10 (IV-3) 8000 sheets   Example 11 (IV-7) 7,000 sheets   Example 12 (IV-13) 8000 sheets ────────────────────────────────────

Examples 13 to 16 (Formation of Image Forming Layer) An image forming layer was formed in the same manner as in Examples 5 to 8 on the hydrophilic layer prepared in Examples 9 to 12, and lithographic printing was performed. An original plate was made.

(Plate making, printing, evaluation) The lithographic printing plate precursor thus prepared was subjected to the same exposure and printability evaluation as in Example 1. The results are shown in Table 4.

[0133]

[Table 4]                                 Table 4 ──────────────────────────────────── Lithographic printing original plate Benzocyclobutene compound ────────────────────────────────────   Example 13 (IV-1) 7500 sheets   Example 14 (IV-3) 8000 sheets   Example 15 (IV-7) 7,000 sheets   Example 16 (IV-8) 8000 sheets ────────────────────────────────────

[0134]

According to the present invention, a lithographic printing plate having extremely high printing durability can be prepared from a lithographic printing original plate having high sensitivity. That is, since the Diels-Alder reaction adopted by the present invention is hardly affected by the reaction inhibition by oxygen in the air, the sensitivity of the original plate is not lowered by oxygen, and the hydrophobic region having a very high strength is used. Can be formed.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H025 AA01 AA12 AB03 AC01 AC08                       AD01 AD03 BH03 CC20 DA36                 2H084 AA14 AA30 AA38 AE05 CC05                 2H096 AA07 AA08 BA06 CA05 EA04                 2H114 AA04 AA22 AA23 AA24 AA27                       BA01 BA10 DA41 DA75 EA01                       EA03 EA05 EA08 GA01 GA23                       GA38

Claims (4)

[Claims] 1. A support, a hydrophilic layer, and an image forming layer are provided in this order, and the hydrophilic layer has at least one of a structure of a diene or a precursor thereof and a structure of a dienophile or a precursor thereof. Containing a plurality of hydrophilic polymers, the image forming layer, at least a lithographic printing plate precursor containing a compound having a plurality of the other structure of them, is imagewise heated to react the polymer and the compound by Diels-Alder reaction, A method of making a lithographic printing plate comprising a step of forming a hydrophobic region and a step of removing an image forming layer. 2. A support, a hydrophilic layer, and an image-forming layer are provided in this order, and the hydrophilic layer has at least one of a structure of a diene or a precursor thereof and a structure of a dienophile or a precursor thereof. Containing a plurality of hydrophilic polymers, the image-forming layer, at least a lithographic printing original plate containing a compound having a plurality of the other structure thereof, is heated in an image manner, the polymer and the compound are reacted by a Diels-Alder reaction, A step of forming a hydrophobic region, the lithographic printing plate precursor is attached to the printing machine and the printing machine is operated, dampening water, ink, or a step of removing the image forming layer by rubbing, thereby making a lithographic printing plate A lithographic printing method comprising the steps of supplying dampening water and oil-based ink and printing with a lithographic printing plate that has been made. 3. A support, a hydrophilic layer, and an image-forming layer are provided in this order, and the hydrophilic layer has at least one of a structure of a diene or a precursor thereof and a structure of a dienophile or a precursor thereof. A lithographic printing original plate comprising a hydrophilic polymer having a plurality of the above, and the image forming layer containing a compound having at least the other structure thereof. 4. A support, a hydrophilic layer, and an image-forming layer are provided in this order, and the hydrophilic layer has at least one of a structure of a diene or a precursor thereof and a structure of a dienophile or a precursor thereof. A lithographic printing original plate comprising a hydrophilic polymer having a plurality of the above, and the image forming layer containing at least a compound having a plurality of the other structures thereof in the form of fine particles.