JP2000037967A - Manufacture of lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithographic printing plate manufacturing method not requiring special processing such as the wet development processing after heating or image exposing and free from foul properties of a printed matter. SOLUTION: A lithographic printing original plate having a layer containing a hydrophobic polymer compound in which side chains are turned to be hydrophilic by being heated on a substrate with a hydrophilic surface is heated to form an image shape and then a recording layer on a printer is removed. In the case of exposing the same to form the image shape by laser exposure, the layer containing a hydrophobic polymer also contains a photothermal conversion material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of making a lithographic printing plate, and more particularly to a method of making a lithographic printing plate which can be made directly by operating a laser or the like based on a digital signal.

[0002]

2. Description of the Related Art Conventionally, as a method of making a printing plate directly from digitized image data without passing through a lithographic film, an electrophotographic method or a method of writing with a relatively small output laser emitting blue or green light can be used. A method using a high-sensitivity photopolymer, a method using a silver salt or a composite system of a silver salt and another system, a method of generating an acid by heat mode laser exposure and obtaining a thermosetting image by post-heating using the acid as a catalyst, etc. It has been known.

Although these methods are extremely useful in streamlining the printing process, they are not always satisfactory at present. For example, in the case of using the electrophotographic method, an image forming process such as charging, exposure, and development is complicated, and the apparatus is complicated and large. Further, in the case of using the photopolymer, since a printing plate having high sensitivity is used, it is difficult to handle in a bright room. The method using a silver salt has disadvantages such as complicated processing and silver contained in the processing waste liquid. Also requires post-heating and subsequent development processing, which complicates the processing.

[0004] Further, in the production of these printing plates, after the exposure process, a wet development process for removing the recording layer provided on the surface of the support in an image-like manner or a printing plate subjected to the development process is used. A post-treatment step of washing with water, or treating with a rinse solution containing a surfactant, gum arabic, or a desensitizing solution containing a starch derivative is included. On the other hand, in the plate making and printing industries in recent years, plate making operations have been rationalized, and there has been a demand for a printing plate precursor that can be used for printing directly after exposure without the need for such a complicated wet development process. For a printing plate precursor that does not require a development treatment after image exposure, for example, US Pat. No. 5,258,263 discloses a photosensitive hydrophilic layer and a photosensitive hydrophobic layer in which curing or insolubilization is promoted in an exposed area. And a lithographic printing plate in which is laminated on a support. However, this plate is a so-called development type printing plate in which unexposed portions of the photosensitive layer are removed in the printing process, and has a drawback of contaminating fountain solution and printing ink.

[0005] Further, as a lithographic printing plate precursor which does not require wet development after image formation, a plate material provided with a silicone layer and a laser heat-sensitive layer below the silicone layer is disclosed in US Patent No. 5,35.
No. 3,705, U.S. Pat. No. 5,379,698. Although these do not require wet development, they require rubbing to complete the removal of the silicone layer by laser abrasion and treatment with a special roller, which has the disadvantage of complicating the treatment. It is possible to form a lithographic printing plate precursor that does not require a development process by using a film in which a polyolefin is sulfonated and changing the hydrophilicity of the surface by thermal writing, as disclosed in JP-A-5-77574 and JP-A-5-77574. 4-125189
No. 5,187,047, JP-A-6
No. 2,195,646. In this system, the sulfone groups on the surface of the printing plate are desulfonated by thermal writing to form an image.
It has the disadvantage of generating harmful gas during writing.

[0006] US Patent No. 5,102,771,
U.S. Pat. No. 5,225,316 discloses a lithographic printing plate precursor in which a polymer having an acid-sensitive group in the side chain and a photoacid generator are combined, and a non-developing system is proposed. Since the acid generated is a carboxylic acid, this lithographic printing plate precursor has only a limited hydrophilic property, and has a disadvantage that the durability of the plate material and the sharpness of a printed image are poor. Also,
JP-A-7-186562 (EP652,483) discloses a lithographic printing plate precursor having a recording layer containing a polymer that generates carboxylic acid by the action of heat and acid and an infrared absorbing dye. However, a lithographic printing plate using this lithographic printing plate precursor has a problem in that stains occur during printing.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to use a heat-sensitive image forming material capable of forming an image with high sensitivity by heating or heat generated by light-to-heat conversion in a recording layer. A lithographic plate that can be directly made from digital data by recording using a laser exposure method, does not require special processing such as wet development processing or rubbing after heating or image exposure, and has no stain on printed matter. An object of the present invention is to provide a printing plate making method.

[0008]

Means for Solving the Problems As a result of intensive studies, the inventors have found that the above-mentioned object can be achieved by the following means, and have completed the present invention. That is, the present invention is as follows. (1) A lithographic printing plate precursor having a layer containing a hydrophobic polymer compound whose side chain changes to hydrophilic by heat on a support whose surface is subjected to a hydrophilic treatment is heated image-wise, and then the recording layer is removed. A method for making a lithographic printing plate, comprising removing the lithographic printing plate on a printing press. (2) A lithographic printing plate precursor having a layer containing a hydrophobic polymer compound whose side chain changes to hydrophilic by heat and a photothermal conversion material on a support whose surface has been subjected to a hydrophilic treatment is image-wise formed by laser exposure. A plate making method for a lithographic printing plate, comprising, after exposure, removing an exposed portion recording layer on a printing machine.

In the prior art, even when a recording layer containing a thermosensitive polymer compound is used, if the amount of heating or the amount of laser exposure is insufficient, the surface side of the recording layer becomes hydrophilic by heat conversion and becomes wet. Although it is eluted by water, the above-mentioned reaction is insufficient at the portion on the side of the support, and as a result, a residual film of the recording layer is formed, which causes staining of the non-image portion at the time of printing. Therefore, in order to remove this residual film, further steps such as reheating of the lithographic printing original plate were required.
However, in the method of making a lithographic printing plate of the present invention, by using a support whose surface is subjected to a hydrophilic treatment, even when a residual film of the recording layer occurs, dampening water permeates into the residual film and supports the recording layer. It is considered that the residual film is easily peeled off when reaching the hydrophilic treatment layer of the body.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The support of the lithographic printing plate precursor used in the method of the present invention is not particularly limited as long as its surface has been subjected to a hydrophilic treatment. Specifically, there can be mentioned those obtained by subjecting the surface of a general-purpose support used for a lithographic printing plate precursor to a hydrophilic treatment. The hydrophilic treatment of the surface of the general-purpose support is not particularly limited, and examples thereof include silicate treatment, polyvinylphosphonic acid treatment, sol-gel treatment, and tamol treatment.

Hereinafter, the silicate treatment will be described.
In the silicate treatment, the surface of the support is subjected to a hydrophilic treatment using an aqueous solution of an alkali metal silicate. For the hydrophilization treatment with the alkali metal silicate, various conventionally known methods can be adopted, but the amount of the alkali metal silicate deposited on the aluminum support surface is reduced to Si.
The amount of atoms is 0.1 to 8 mg / m ² , preferably 0.1 to 8 mg / m ² .
5-6 mg / m ² , more preferably 0.5-4 mg / m ²
m ² . If the attached amount is less than 0.1 mg / m ^{2 in} terms of the amount of Si atoms, the contamination performance is poor and the intended purpose cannot be achieved. Further, when a developer containing no alkali metal silicate is used in the developer, it is not possible to prevent whitening of a non-image portion during development and generation of scum and sludge during development. Further, the amount of adhesion is 8 mg as the amount of Si atoms.
If it exceeds / m ² , the printing durability is poor and the intended purpose cannot be achieved.

In the present invention, the amount of the alkali metal silicate deposited on the surface of the support is determined by an X-ray fluorescence spectrometer (XRF; X-ray Fluorescence S).
spectrometer) and S
It is measured as the amount of i atoms (Simg / m ² ). A standard sample for preparing a calibration curve was prepared by applying a sodium silicate aqueous solution containing a known amount of Si atoms to a 30 mmφ on a support.
After uniformly dripping in the area of, dried. Although there is no particular limitation on the model of the X-ray fluorescence spectrometer, RIX30 manufactured by Rigaku Denki Kogyo
Using the sample No. 00, the amount of Si atoms was measured from the peak height of the Si-Kα spectrum under the following conditions.

Apparatus: RIX3000, manufactured by Rigaku Denki Kogyo Co., Ltd. X-ray tube: Rh Measurement spectrum: Si-Kα Tube voltage: 50 kV Tube current: 50 mA Slit: COARSE Spectral crystal: RX4 Detector: F-PC Analysis area: 30 mmφ Peak position (2θ): 144.75 deg. Background (2θ): 140.70 deg. , 146.85 deg. Integration time: 80 seconds / sample

In the hydrophilization treatment, the alkali metal silicate contains 0.001 to 30% by weight, preferably 0.01 to 10% by weight.
Wt.%, Particularly preferably 0.1 to 5 wt%, of an alkali metal silicate aqueous solution having a pH of 10 to 13 at 25 ° C. By immersing for 0.5 to 120 seconds, preferably for 2 to 30 seconds, processing conditions such as alkali metal silicate concentration, processing temperature, and processing time are appropriately selected so that the attached amount of Si atoms becomes the above specific amount. It can be preferably performed. In performing this hydrophilization treatment, if the pH of the aqueous solution of the alkali metal silicate is lower than 10, the solution gels, and if the pH is higher than 13.0, the anodic oxide film is dissolved.

As the alkali metal silicate used in the hydrophilic treatment of the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used. In the hydrophilization treatment of the present invention, if necessary, a hydroxide can be blended to adjust the pH of the aqueous solution of the alkali metal silicate to a high value. As the hydroxide, sodium hydroxide,
Potassium hydroxide, lithium hydroxide and the like can be mentioned. If necessary, an alkaline earth metal salt or a Group IVB metal salt may be added to the aqueous alkali metal silicate solution. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and sulfates, hydrochlorides, phosphates, acetates, oxalates, and the like of these alkaline earth metals. And water-soluble salts such as borate. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide,
Zirconium oxychloride, zirconium tetrachloride and the like can be mentioned. Alkaline earth metal salt or IVB
Group metal salts can be used alone or in combination of two or more. The preferred use amount range of these metal salts is 0.1.
01 to 10% by weight, and a more preferred range is 0.0 to 10% by weight.
5 to 5.0% by weight.

In the present invention, the support subjected to the hydrophilization treatment can be treated with an acidic aqueous solution, if necessary. Examples of the acidic aqueous solution include aqueous solutions of sulfuric acid, nitric acid, hydrochloric acid, oxalic acid, phosphoric acid, and the like. In addition, the acidic aqueous solution treatment converts the support subjected to the hydrophilization treatment to an aqueous solution having an acid concentration of 0.001 to 10% by weight, preferably 0.01 to 1% by weight, at a temperature of 15 to 70 ° C. The immersion is preferably performed at 25 to 50 ° C. for 0.5 to 120 seconds, preferably for 2 to 30 seconds. By this acidic aqueous solution treatment, adjustment can be made to reduce the amount of the alkali metal silicate attached to the support by the hydrophilic treatment.

Next, the polyvinyl phosphonic acid treatment will be described. The polyvinyl phosphonic acid treatment is a treatment in which the surface of the support is hydrophilized with an aqueous solution of polyvinyl phosphonic acid. The aqueous solution used for the polyvinyl phosphonic acid aqueous solution treatment has a concentration of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, more preferably 0.2 to 2.5% by weight, and a temperature of 10 ° C. To 70 ° C., preferably 30 to 60 ° C., and 0.5 seconds to 4
It is appropriate to carry out by immersion for 0 second, more preferably for 1 to 20 seconds.

The concentration of the aqueous solution of polyvinyl phosphonic acid is 0.
When the concentration is lower than 01% by weight, the amount of adsorption of polyvinylphosphonic acid to the anodic oxide film described below decreases, and sufficient printing durability cannot be obtained. On the other hand, when the concentration is higher than 10% by weight, the amount of adsorption of polyvinylphosphonic acid increases. It becomes too much, and the payment stain deteriorates. On the other hand, if the treatment temperature is lower than 10 ° C., the amount of polyvinyl phosphonic acid adsorbed on the anodic oxide film decreases, and sufficient printing durability cannot be obtained. On the other hand, if the processing temperature is higher than 70 ° C., the amount of adsorbed polyvinyl phosphonic acid increases. It is too much and the dirt on payment deteriorates. Furthermore, the immersion time is 0.5
If the time is shorter than 2 seconds, the amount of polyvinylphosphonic acid adsorbed on the anodic oxide film is reduced and sufficient printing durability cannot be obtained.On the other hand, if the time is longer than 40 seconds, the amount of adsorbed polyvinylphosphonic acid becomes too large and stains are removed. Will deteriorate. The pH of the aqueous polyvinyl phosphonic acid solution is preferably 1.5 or less.

Next, the sol-gel treatment will be described. The sol-gel treatment is a treatment described in JP-A-9-269593, in which a sol solution or a liquid composition is applied to the surface of a support and then air-dried or heat-dried. As a result, the inorganic polymer comprising the metal-oxygen-metal bond is gelled and simultaneously covalently bonds with the support surface. Drying is performed to evaporate the solvent, residual water and optionally the catalyst,
The step can be omitted depending on the purpose of use of the treated support. In order to increase the adhesion between the inorganic polymer portion in the liquid composition according to this method and the surface of the metal to be treated, a temperature can be positively applied. The drying step in this case is
It can be continuously carried out even after evaporation of the solvent, water and the like. The maximum temperature during drying and, optionally, subsequent heating is preferably in such a range that the functional groups implanted on the metal surface do not decompose. Accordingly, the drying temperature conditions that can be used are room temperature to 200 ° C, preferably room temperature to 150 ° C, and more preferably room temperature to 120 ° C. Drying time is generally 30 seconds to
It is 30 minutes, preferably 45 seconds to 10 minutes, more preferably 1 minute to 3 minutes. The application method of the liquid composition (organic silicone compound or its solution or sol solution) used in the present invention includes brush coating, dip coating, atomizing, spin coating, doctor blade coating, and the like.
Various types can also be used, and are determined in consideration of the shape of the support surface, the required thickness of the processed film, and the like. When the support is a metal plate, when treating the metal surface, it is preferable that the surface is a clean surface free of oils and the like, except when the support is significantly contaminated by oils and the like. Can be used as is. If necessary, the metal surface may be roughened by mechanically roughening or electrolytic deposition, electrolytic etching, or the like. In addition, those in which a natural oxide film is formed on the metal surface or those whose surface is positively oxidized by anodic oxidation, contact oxidation or the like can be suitably used. Of course, an oxide film different from the base metal may be provided on the surface by thermal spraying, coating, CVD, or the like.

The general-purpose support whose surface is subjected to the above-mentioned hydrophilization treatment is not particularly limited as long as it is a dimensionally stable plate-like material. Examples thereof include paper, plastic (eg, polyethylene, polypropylene, polystyrene, etc.). ) Laminated paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, Polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic film on which the above-mentioned metal is laminated or vapor-deposited.

As the support of the present invention, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate which has good dimensional stability and is relatively inexpensive is particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of foreign elements in the alloy is at most 10% by weight
It is as follows. Aluminum which is particularly preferred in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, particularly preferably 0.1 mm to 0.4 mm.
It is 2 mm to 0.3 mm.

The support is subjected to the above-described hydrophilization treatment. In the case of a support having a metal, particularly aluminum surface, graining treatment, sodium silicate, potassium fluorozirconate, phosphate, It is preferable that a surface treatment such as an immersion treatment in an aqueous solution or an anodizing treatment is performed. Also, as described in U.S. Pat. No. 2,714,066, an aluminum plate grained and then immersed in an aqueous solution of sodium silicate is described in U.S. Pat. No. 3,181,461. As described above, those obtained by subjecting an aluminum plate to anodizing treatment and then immersing it in an aqueous solution of an alkali metal silicate are also preferably used. The anodizing treatment is, for example, an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, or boric acid, or oxalic acid, an organic acid such as sulfamic acid, or an aqueous or non-aqueous solution of a salt thereof alone or in combination of two or more. It is carried out by flowing a current in an electrolytic solution using an aluminum plate as an anode.

As the graining method, any of mechanical, chemical and electrochemical methods is effective. Examples of the mechanical method include a ball polishing method, a blast polishing method, and a brush polishing method in which an aqueous dispersion slurry of an abrasive such as pumice is rubbed with a nylon brush, and the chemical method is disclosed in JP-A-54-31187. A method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in the official gazette is suitable, and as an electrochemical method, a method of alternating current electrolysis in an acidic electrolyte such as hydrochloric acid, nitric acid or a combination thereof is used. Is preferred. Among such surface-roughening methods, a surface-roughening method combining mechanical surface-roughening and electrochemical surface-roughening as described in JP-A-55-137993 is particularly preferred. Is preferred because of its strong adhesion to the support. The graining by the method as described above has a center line surface roughness (Ha) of 0.3 to 1.0 μm on the surface of the aluminum plate.
It is preferable that the application is performed in such a range as follows. The aluminum plate thus grained is washed with water and chemically etched as required.

The etching solution is usually selected from aqueous solutions of bases or acids which dissolve aluminum. In this case, a film different from aluminum derived from the etchant component must not be formed on the etched surface. Preferred examples of the etching agent include sodium hydroxide, potassium hydroxide, trisodium phosphate, disodium phosphate, tripotassium phosphate, and dipotassium phosphate as basic substances; and sulfuric acid and persulfuric acid as acidic substances. , Phosphoric acid, hydrochloric acid, and salts thereof. Metals having a lower ionization tendency than aluminum, such as zinc, chromium, cobalt, nickel, and copper, are not preferable because they form an unnecessary film on the etched surface. In these etching agents, the dissolution rate of the aluminum or alloy to be used is determined by the immersion time 1 at the setting of the working concentration and temperature.
Most preferably from minute per 0.3 g / m ² from being carried out so as to become 40 g / m ^2, but no problem even well below or above this.

The etching is performed by immersing the aluminum plate in the above-mentioned etching solution or by applying an etching solution to the aluminum plate.
The treatment is preferably performed so as to be in the range of 10 to 10 g / m ² . As the etching agent, it is desirable to use an aqueous solution of a base because of its high etching rate. In this case, since a smut is generated, a normal desmutting process is performed. The acid used for desmut treatment is
Nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borofluoric acid and the like are used. These etchants, use concentration, in the setting of temperature, most preferably the rate of dissolution of aluminum or alloy used is performed as consisting of immersion time 1 minute per 0.3 g / m ² to 40 g / m ² It may be higher or lower than this.

The etching is performed by immersing the aluminum plate in the above-mentioned etching solution or by applying an etching solution to the aluminum plate.
The treatment is preferably performed so as to be in the range of 10 to 10 g / m ² . As the etching agent, it is desirable to use an aqueous solution of a base because of its high etching rate. In this case, since a smut is generated, a normal desmutting process is performed. The acid used for desmut treatment is
Nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borofluoric acid and the like are used. The etched aluminum plate is optionally washed with water and anodized. The anodic oxidation can be performed by a method conventionally used in this field. Specifically, when direct current or alternating current is passed through aluminum in an aqueous solution or a non-aqueous solution of sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, or a combination of two or more thereof, aluminum An anodized film can be formed on the surface of the support.

The anodizing treatment conditions cannot be generally determined because they vary depending on the electrolytic solution to be used, but generally the concentration of the electrolytic solution is 1 to 80% by weight and the liquid temperature is 5 to 70%.
° C, current density 0.5-60 amps / dm ² , voltage 1-10
0V and an electrolysis time of 30 seconds to 50 minutes are appropriate. Among these anodizing treatments, in particular, British Patent No. 1,4
Anodizing at high current density in sulfuric acid as described in U.S. Pat.
The method of anodic oxidation using phosphoric acid as an electrolytic bath described in US Pat.

If necessary, the back of the support may be
A light coat is provided. As such a back coat
Organic polymer compounds described in JP-A-5-45885 and
Or inorganic or organic compounds described in JP-A-6-35174
Metals obtained by hydrolysis and polycondensation of metal compounds
An oxide coating layer is preferably used. these
Among the coating layers, Si (OCH_Three)_Four, Si (OC_TwoH_Five)_Four, S
i (OC_ThreeH₇) _Four, Si (OC_FourH₉)_FourSuch as silicon al
Koxy compounds are inexpensive and readily available, and gold obtained from them
A coating layer of a metal oxide is particularly preferred because of its excellent hydrophilicity.

An image recording layer containing a hydrophobic polymer compound whose side chain changes to hydrophilic by heat is formed on the support whose surface has been hydrophilized. The hydrophobic high molecular compound whose side chain changes to hydrophilic by heat contained in the image recording layer of the lithographic printing plate precursor used in the method of the present invention is not particularly limited, but is represented by the following general formulas (1) to (1). Those having at least one of the functional groups represented by any of (5) in the side chain are mentioned.

[0030]

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(Wherein L is linked to the hydrophobic polymer compound main chain)
Represents an organic group consisting of linked polyvalent nonmetallic atoms,¹Is
Represents an aryl group, an alkyl group or a cyclic imide group,
R^Two, R^ThreeRepresents an aryl group or an alkyl group;^FourIs
Aryl group, alkyl group or -SO _TwoR^FiveAnd R^Five
Represents an aryl group or an alkyl group;⁶, R⁷And R
⁸Each independently represents an aryl group or an alkyl group,
R⁶, R⁷And R⁸A ring with any two or three of
May be formed. R⁹And R^TenIs a hydrogen atom
And the other represents a hydrogen atom, an aryl group or an alkyl group.
Then R¹¹Represents an alkyl group;⁹And R¹¹Or R^TenAnd R
¹¹May form a ring. )

L is a polyvalent linking group consisting of a nonmetallic atom, and has 1 to 60 carbon atoms, 0 to 10 nitrogen atoms,
It is composed of 0 to 50 oxygen atoms, 1 to 100 hydrogen atoms, and 0 to 20 sulfur atoms. More specifically, there can be mentioned those constituted by combining the following structural units.

[0033]

Embedded image

When the polyvalent linking group has a substituent, examples of the substituent include an alkyl group having 1 to 20 carbon atoms such as methyl and ethyl, an aryl group having 6 to 16 carbon atoms such as phenyl and naphthyl, and a hydroxyl group. Carboxyl group, sulfonamide group, N-sulfonylamide group, acyloxy group having 1 to 6 carbon atoms such as acetoxy, alkoxy group having 1 to 6 carbon atoms such as methoxy and ethoxy, chlorine and bromine An alkoxycarbonyl group having 2 to 7 carbon atoms, such as a halogen atom, methoxycarbonyl, ethoxycarbonyl, and cyclohexyloxycarbonyl, a cyano group, and a carbonate group such as t-butyl carbonate can be used.

When R ^{1 to} R ⁵ represent an aryl group or a substituted aryl group, the aryl group includes a carbocyclic aryl group and a heterocyclic (hetero) aryl group. As the carbocyclic aryl group, those having 6 to 19 carbon atoms such as a phenyl group, a naphthyl group, an anthracenyl group and a pyrenyl group are used. Examples of the heterocyclic aryl group include a pyridyl group, a furyl group, and other quinolyl groups in which a benzene ring is fused, a benzofuryl group, a thioxanthone group, and a carbazole group. Things are used. When R ^{1 to} R ⁵ represent an alkyl group or a substituted alkyl group, the alkyl group may be a linear, branched or cyclic carbon atom such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a cyclohexyl group and the like. Those from 1 to 25 are used.

When R ^{1 to} R ⁵ are a substituted aryl group, a substituted heteroaryl group or a substituted alkyl group, examples of the substituent include a methoxy group, an ethoxy group and the like, an alkoxy group having 1 to 10 carbon atoms, a fluorine atom, and a chlorine atom. Atom, halogen atom such as bromine atom, trifluoromethyl group, halogen-substituted alkyl group such as trichloromethyl group, methoxycarbonyl group, ethoxycarbonyl group, t-butyloxycarbonyl group, p-chlorophenyloxycarbonyl group, etc. An alkoxycarbonyl group or an aryloxycarbonyl group having 2 to 15 carbon atoms; a hydroxyl group; an acyloxy group such as an acetyloxy group, a benzoyloxy group, a p-diphenylaminobenzoyloxy group; a carbonate group such as a t-butyloxycarbonyloxy group; t-butyloxycarbonyl Ether groups such as tyloxy group and 2-pyranyloxy group; substituted and unsubstituted amino groups such as amino group, dimethylamino group, diphenylamino group, morpholino group and acetylamino group; thioether groups such as methylthio group and phenylthio group; vinyl An alkenyl group such as a group or styryl group; a nitro group; a cyano group; an acyl group such as a formyl group, an acetyl group or a benzoyl group; an aryl group such as a phenyl group or a naphthyl group; and a heteroaryl group such as a pyridyl group. be able to. When R ^{1 to} R ⁵ are a substituted aryl group or a substituted heteroaryl group, an alkyl group such as a methyl group or an ethyl group can be used as the substituent other than the above.

When R ¹ represents a cyclic imide group, examples of the cyclic imide include those having 4 to 20 carbon atoms, such as succinimide, phthalimide, cyclohexanedicarboxylic imide, norbornenedicarboxylic imide and the like. .

Among the above, R ¹ is particularly preferably an aryl group substituted with an electron-withdrawing group such as halogen, cyano or nitro, an alkyl group substituted with an electron-withdrawing group such as halogen, cyano or nitro. They are a secondary or tertiary branched alkyl group, a cyclic alkyl group and a cyclic imide. Of the above, particularly preferred as R ^{2 to} R ⁵ are an aryl group substituted with an electron-withdrawing group such as halogen, cyano and nitro, and an alkyl group substituted with an electron-withdrawing group such as halogen, cyano and nitro. And secondary or tertiary branched alkyl groups. R ^6-
Preferred as R ¹¹ is an alkyl group or an aryl group, in the case where any two or three of R ⁶ , R ⁷ and R ⁸ form a ring, and R ⁹ and R ¹¹ or R ^{11 Ten}
And R ¹¹ form a ring. At this time, the alkyl group and the aryl group may have a substituent, and preferable substituents include a methyl group, a methoxy group, and a halogen atom.

Among the compounds having a functional group represented by the general formulas (1) to (5), those represented by the general formulas (1), (4),
A compound having a functional group represented by (5) is preferable, and among compounds having a functional group represented by general formula (1), a compound having a secondary alkyl group represented by the following general formula (6) Is preferred.

[0040]

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R ⁶ and R ⁷ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group;
R ⁶ and R ⁷ may form a ring together with the secondary carbon atom (CH) to which they are attached. When R ⁶ and R ⁷ represent a substituted or unsubstituted alkyl group, examples of the alkyl group include a linear, branched or cyclic alkyl group such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group and a cyclohexyl group. And those having 1 to 25 carbon atoms are preferably used. When R ⁶ and R ⁷ represent a substituted or unsubstituted aryl group, the aryl group includes a carbocyclic aryl group and a heterocyclic aryl group. As the carbocyclic aryl group, those having 6 to 19 carbon atoms such as a phenyl group, a naphthyl group, an anthracenyl group and a pyrenyl group are used. Examples of the heterocyclic aryl group include those having 3 to 20 carbon atoms and 1 to 5 heteroatoms such as a pyridyl group, a furyl group, a quinolyl group in which a benzene ring is fused, a benzofuryl group, a thioxanthone group, and a carbazole group. Is used.

When R ⁶ and R ⁷ are a substituted alkyl group or a substituted aryl group, examples of the substituent include an alkoxy group having 1 to 10 carbon atoms such as a methoxy group and an ethoxy group, a fluorine atom, a chlorine atom and a bromine atom. A halogen atom, a trifluoromethyl group, a halogen-substituted alkyl group such as a trichloromethyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a t-butyloxycarbonyl group, a p-chlorophenyloxycarbonyl or the like having 2 to 15 carbon atoms.
A hydroxyl group; an acyloxy group such as acetyloxy, benzoyloxy, p-diphenylaminobenzoyloxy; a carbonate group such as a t-butyloxycarbonyloxy group; a t-butyloxycarbonylmethyloxy group A substituted or unsubstituted amino group such as an amino group, a dimethylamino group, a diphenylamino group, a morpholino group, or an acetylamino group; a thioether group such as a methylthio group or a phenylthio group; a vinyl group; Alkenyl groups such as steryl group; nitro group; cyano group; acyl groups such as formyl group, acetyl group and benzoyl group; aryl groups such as phenyl group and naphthyl group; heteroaryl groups such as pyridyl group. Can . When R ⁶ and R ⁷ are substituted aryl groups, alkyl groups such as a methyl group and an ethyl group can be used as the substituent in addition to those described above.

As the above R ⁶ and R ⁷ , a substituted or unsubstituted alkyl group is preferable from the viewpoint of excellent storage stability of the light-sensitive material, and an alkoxy group, a carbonyl group,
A secondary alkyl group substituted with an electron-withdrawing group such as an alkoxycarbonyl group, a cyano group, or a halogen group, or a secondary alkyl group such as a cyclohexyl group or a norbornyl group is particularly preferable. As a physical property value, in heavy chloroform, a compound in which the chemical shift of secondary methine hydrogen in proton NMR appears in a lower magnetic field than 4.4 ppm is preferable, and a compound in which the chemical shift appears in a lower magnetic field than 4.6 ppm is more preferable. Thus, 2 substituted with an electron-withdrawing group
It is considered that the higher alkyl group is particularly preferable because the carbocation, which is considered to be generated as an intermediate during the thermal decomposition reaction, is destabilized by the electron-withdrawing group and the decomposition is suppressed. Specifically, as the structure of —CHR ⁶ R ^7, a structure represented by the following formula is particularly preferable.

[0044]

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In the general formula (6), L is the same as in the general formulas (1) to (5).

Specific examples of the monomer having a functional group represented by any one of formulas (1) to (5), which is preferably used for synthesizing the thermosensitive polymer compound in the present invention, are shown below.

[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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In the present invention, the compounds represented by general formulas (1) to (1) are preferably used.
A polymer compound obtained by radical polymerization using at least one of the monomers having a functional group represented by (5) is used. As such a polymer compound, a homopolymer using only one of the monomers having a functional group represented by the general formulas (1) to (5) may be used, but two or more kinds thereof are used. Copolymers or copolymers of these monomers with other monomers may be used. In the present invention, a polymer compound more preferably used is a copolymer obtained by radical polymerization of the above monomer and another known monomer.

Other monomers used in the copolymer include, for example, acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride Known monomers such as acid and maleic imide are also included.

Specific examples of the acrylates include:
Methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec-
Or t-) butyl acrylate, amyl acrylate,
2-ethylhexyl acrylate, dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
5-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, chlorobenzyl acrylate, hydroxybenzyl acrylate, hydroxyphenethyl acrylate, dihydroxyphenethyl acrylate, furfuryl acrylate, Examples thereof include tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyphenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate, and 2- (hydroxyphenylcarbonyloxy) ethyl acrylate.

Specific examples of the methacrylates include methyl methacrylate, ethyl methacrylate,
(N- or i-) propyl methacrylate, (n-, i
-, Sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate,
Dodecyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate,
Glycidyl methacrylate, benzyl methacrylate,
Methoxybenzyl methacrylate, chlorobenzyl methacrylate, hydroxybenzyl methacrylate, hydroxyphenethyl methacrylate, dihydroxyphenethyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, hydroxyphenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate, 2- (hydroxyphenyl Carbonyloxy) ethyl methacrylate and the like.

Specific examples of acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide,
Hydroxyethylacrylamide, N-phenylacrylamide, N-tolylacrylamide, N- (hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl)
Acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-
N-phenylacrylamide, N-hydroxyethyl-
N-methylacrylamide and the like can be mentioned.

Specific examples of methacrylamides include methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, N-propyl methacrylamide, N-butyl methacrylamide, N-benzyl methacrylamide, N-hydroxyethyl methacryl Amide,
N-phenylmethacrylamide, N-tolylmethacrylamide, N- (hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N
-(Tolylsulfonyl) methacrylamide, N, N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like.

Specific examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate and the like.

Specific examples of styrenes include styrene,
Methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, propylstyrene, cyclohexylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene, methoxystyrene, dimethoxystyrene,
Chlorostyrene, dichlorostyrene, bromostyrene,
Examples thereof include iodostyrene, fluorostyrene, carboxystyrene, and the like.

Among these other monomers, particularly preferred are acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid esters having a C20 or less. Acid and acrylonitrile. The proportion of the monomer having a functional group represented by any one of the general formulas (1) to (5) used in the synthesis of the copolymer is preferably 5 to 99% by weight, more preferably 10 to 95% by weight. It is.

Hereinafter, specific examples of the polymer compound having a functional group represented by the general formulas (1) to (5) will be shown.

[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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The numbers in the formula represent the molar composition of the polymer compound.

Further, the compounds represented by the general formulas (1) to (1)
The weight average molecular weight of the polymer compound having at least one of the functional groups represented by (5) is preferably 2000
Or more, more preferably in the range of 5000 to 300,000, the number average molecular weight is preferably 800 or more,
More preferably, it is in the range of 1,000 to 250,000. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1 or more, and more preferably in the range of 1.1 to 10. These polymer compounds may be any of a random polymer, a block polymer, a graft polymer and the like, but are preferably random polymers.

As the solvent used for synthesizing the hydrophobic polymer compound used in the present invention, tetrahydrofuran, ethylene dichloride, etc. can be used alone or in combination of two or more. As the radical polymerization initiator used for synthesizing the hydrophobic polymer compound used in the present invention, known compounds such as an azo initiator and a peroxide initiator can be used. The recording layer of the lithographic printing plate precursor used in the method of the present invention may be composed of a hydrophobic polymer compound alone, or does not impair the effects of the present invention as necessary. It may be constituted by other components within the range. In the recording layer, the hydrophobic polymer compound accounts for 50 to 90% by weight, preferably 70% by weight of the total solids of the recording layer.
It can be used in a proportion of up to 90% by weight. When the addition amount is less than 50% by weight, the printed image becomes unclear, and when the addition amount exceeds 90% by weight, image formation by laser exposure cannot be sufficiently performed.

The following compounds may be mentioned as components other than the hydrophobic polymer compound of the recording layer of the lithographic printing plate precursor used in the method of the present invention.

[Light-to-Heat Conversion Material] When the recording layer of the lithographic printing plate precursor used in the method of the present invention is to be image-formed by laser exposure, a light-to-heat conversion material is contained in addition to the above hydrophobic polymer compound. Let it. As the photothermal conversion material, any substance that can convert light into heat by absorbing light such as ultraviolet light, visible light, infrared light, and white light can be used.Examples include carbon black, carbon graphite, pigments, phthalocyanine pigments, and iron powder. , Graphite powder, iron oxide powder, lead oxide, silver oxide, chromium oxide, iron sulfide, chromium sulfide and the like.
Particularly preferred is a wavelength of 760 nm to 1200 nm.
Dyes, pigments, or metals that effectively absorb infrared rays.

As the dye, commercially available dyes and known dyes described in literatures (eg, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, published in 1970) can be used. Specific examples include azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, and dyes such as metal thiolate complexes. Preferred dyes include, for example, JP-A-58-125246.
JP-A-59-84356, JP-A-59-2028
29, JP-A-60-78787, JP-A-58-173696, and JP-A-5-173696.
Methine dyes described in JP-A-8-181690 and JP-A-58-194595;
JP-A-58-224793, JP-A-59-481
No. 87, JP-A-59-73996, JP-A-60-52
No. 940, JP-A-60-63744 and the like, naphthoquinone dyes described in JP-A-58-112792 and the like, British Patent 434
No. 875, and the like.

Further, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924 is also preferable. JP-A-57-142645 (U.S. Pat. No. 4,327,169) describes a trimethinethiapyrylium salt described in JP-A-58-181051, and JP-A-58-181051, and JP-A-58-181051.
Nos. 8-220143, 59-41363 and 59-
No. 84248, No. 59-84249, No. 59-146
Nos. 063 and 59-146061; cyanine dyes described in JP-A-59-216146; pentamethine thiopyrylium salts described in U.S. Pat. No. 4,283,475; Fairness 5-135
Nos. 14 and 5-19702 are also preferably used. Further, as another preferable example of the dye, a near-infrared absorbing dye described as formulas (I) and (II) in U.S. Pat. No. 4,756,993 can be exemplified. Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes.

The pigment used in the present invention includes
Commercial Pigment and Color Index (CI) Handbook,
"Latest Pigment Handbook" (edited by Japan Pigment Technical Association, 1977), "Latest Pigment Application Technology" (CMC Publishing, 1986), "Printing Ink Technology" CMC Publishing, 1984)
Can be used. The types of pigments include black pigment, yellow pigment, orange pigment, brown pigment,
Red pigment, purple pigment, blue pigment, green pigment, fluorescent pigment,
Metal powder pigments and other polymer-bound dyes can be used.
Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelated azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments And quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like. Preferred among these pigments is carbon black.

These pigments may be used without surface treatment, or may be used after surface treatment. Examples of the surface treatment include a method of surface coating a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (for example, a silane coupling agent, an epoxy compound, or a polyisocyanate) to the pigment surface. Conceivable. The above surface treatment methods are described in “Properties and Applications of Metallic Soap” (Koshobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). I have.

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. Pigment particle size 0.01μ
When it is less than m, the dispersion is not preferred in terms of stability in the coating solution for the photosensitive layer, and when it exceeds 10 μm, it is not preferred in terms of uniformity of the image recording layer. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. As the disperser, an ultrasonic disperser,
Sand mills, attritors, pearl mills, super mills, ball mills, impellers, dispersers, KD mills, colloid mills, dynatrons, three-roll mills, pressure kneaders and the like can be mentioned. Details are described in "Latest Pigment Application Technology" (CMC Publishing, 1986).

These dyes or pigments are used in an amount of 0.01 to 50% by weight, preferably 0.1 to 50% by weight based on the total solids of the image recording layer material.
It can be used in an amount of 10% by weight, particularly preferably 0.5 to 10% by weight for dyes, and particularly preferably 3.1 to 10% by weight for pigments. If the amount of the pigment or dye added is less than 0.01% by weight, the sensitivity becomes low,
If the amount exceeds the weight percentage, stains occur in the non-image area during printing. The concentration of the recording layer material when using the above-mentioned light-to-heat conversion material should be at least 0.3, preferably 0.5, more preferably 1.0 or more in terms of optical density (OD) at the exposure wavelength. However, the OD at this time is a value when the recording layer material composition is applied to a transparent support and measured by transmission. The light-to-heat conversion material may be contained in the image recording layer as described above, or may be contained in the undercoat layer of the recording layer.

[Other Components] In the present invention, the above-mentioned two components are essential, but various compounds other than these may be added as necessary. For example, a dye having a large absorption in the visible light region can be used as a colorant for an image. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603,
Oil Black BY, Oil Black BS, Oil Black T-505 (or more, Orient Chemical Industries, Ltd.)
Manufactured), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42
535), ethyl violet, rhodamine B (CI1
45170B), malachite green (CI4200
0), methylene blue (CI52015) and the dyes described in JP-A-62-293247. These dyes are preferably added because they discolor after laser exposure, and it is easy to distinguish between image areas and non-image areas. The addition amount is 0.01 to 10% by weight based on the total solids of the image recording layer material.

The recording layer according to the present invention is provided in JP-A-62-2517 in order to increase stability under printing conditions.
Non-ionic surfactants described in JP-A-59-121 and JP-A-3-208514.
Further, an amphoteric surfactant as described in JP-A-0444 and JP-A-4-13149 can be added.
Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearic acid, and polyoxyethylene nonyl phenyl ether.
Specific examples of the amphoteric surfactant include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N- Betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and the like. The proportion of the nonionic surfactant and amphoteric surfactant in the image recording layer material is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

Further, a plasticizer may be added to the recording layer of the present invention, if necessary, in order to impart flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers of acrylic acid or methacrylic acid And polymers.

In addition, epoxy compounds, vinyl ethers, phenol compounds having a hydroxymethyl group and phenol compounds having an alkoxymethyl group described in Japanese Patent Application No. 7-18120 may be added. Further, another polymer compound may be added to improve the strength of the coating film.

The lithographic printing plate precursor used in the method of the present invention can be usually produced by dissolving each of the above-mentioned components in a solvent and applying the solution on a support whose surface has been subjected to a hydrophilic treatment. As the solvent used herein, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples thereof include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyrolactone, toluene, water and the like. It is not limited to this. These solvents are used alone or as a mixture. The concentration of the above components (total solids including additives) in the solvent is preferably 1
５０50% by weight. The amount of coating (solid content) on the support obtained after coating and drying varies depending on the application, but generally speaking about a lithographic printing plate precursor, 0.5 to 5.0.
g / m ² is preferred. Various methods can be used as the method of coating, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

The recording layer of the lithographic printing plate precursor used in the method of the present invention is provided with a surfactant for improving coating properties, for example, a fluorine-based surfactant as described in JP-A-62-170950. Surfactants can be added. The amount of these additives is 0.01 to 1 in the solid content of the entire image recording layer material.
% By weight, more preferably 0.05 to 0.5%.
% By weight.

As described above, a lithographic printing plate precursor used in the method of the present invention can be prepared. The lithographic printing plate precursor is exposed imagewise with a solid-state laser or semiconductor laser that emits infrared light having a wavelength of 760 nm to 1200 nm, or is imagewise heated by a thermal (heat-sensitive) head or the like to form an image. In the present invention, it is not necessary to perform a dissolving treatment, it is possible to mount a printing plate on a printing machine immediately after laser irradiation or thermal head heating or the like and perform printing, and to perform steps such as laser irradiation or thermal head heating. It is no longer necessary to perform a reheating process during the printing process. The planographic printing plate obtained by such a process is used for printing a large number of sheets by using an offset printing machine or the like.

[0091]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. (Examples 1 to 3 and Comparative Examples 1 to 3) A 0.30 mm thick aluminum plate (material 1050) was washed with trichlorethylene and degreased, and then its surface was treated with a nylon brush and a 400 mesh pumicestone-water suspension. Was grained and washed well with water. This plate was etched by immersing it in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds, washed with water, and further immersed in 2% nitric acid for 20 seconds and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was treated with a 7% sulfuric acid
After a direct current anodized film of 3 g / m ² in A / dm ^2, washed with water and dried. Further, the treated aluminum plate was treated with an aqueous solution having a sodium silicate concentration of 3% by weight.
The substrate was treated at 0 ° C. for 10 seconds (silicate treatment) to prepare a hydrophilized substrate. The amount of sodium silicate deposited on this substrate was 2.9 mg / m ² as the atomic weight of Si.

Next, in the following solutions, three kinds of solutions were prepared by changing the kind of the heat-sensitive polymer compound as shown in Table 1. Each of the solutions was applied to the above-mentioned hydrophilized aluminum plate and dried at 80 ° C. for 3 minutes to obtain lithographic printing plate precursors [1] to [3]. Weight after drying is 1.2
g / m ² .

Solution Thermosensitive polymer compound (Table 1) 4.0 g Infrared absorber (IR-125, manufactured by Wako Pure Chemical Industries, Ltd.) 0.15 g Fluorosurfactant (Megafac F-177, Dainippon Ink & Chemicals, Inc.) Industrial Co., Ltd.) 0.06 g Methyl ethyl ketone 20 g γ-butyrolactone 10 g 1-methoxy-2-propanol 8 g

[0094]

[Table 1]

The obtained lithographic printing plate precursors [1] to [3]
2. Surface laser power: 200 mW, scanning speed: 3, using a semiconductor laser emitting infrared rays having a wavelength of 838 nm.
Exposure was performed at 0 m / s. After exposure, printing was performed by a Heidel KOR-D machine without post-heating. At this time, it was observed whether or not the non-image portion of the 5000th printed matter was stained. Comparative Examples 1 to 3 were Examples 1 to 3, respectively, except that the hydrophilization treatment by the silicate treatment was not performed.
The same was done. Table 2 shows the results.

[0096]

[Table 2]

As is evident from the results in Table 2, according to the planographic printing plate of the present invention, the non-image portions were all excellent in stains even with exposure at a low scanning energy of 3.0 m / s. A printed matter was obtained.

Example 4 The same procedure as in Example 2 was carried out except that the hydrophilic treatment by the silicate treatment was replaced by the following polyvinylphosphonic acid treatment. The substrate was washed with a 0.5% aqueous solution of polyvinylphosphonic acid adjusted to pH 1.0 by adding a trace amount of sulfuric acid at 60 ° C. for 10 seconds. As a result, similar to Example 2, there was no non-image stain at the time of printing.

Example 5 The same procedure as in Example 2 was carried out except that the hydrophilization treatment by the silicate treatment was replaced by the following sol-gel treatment. 0.24 parts by weight of phenylphosphonic acid is dissolved in a mixture of 130 parts by weight of methanol, 20 parts by weight of water, and 16 parts of 85% phosphoric acid, and this solution is mixed with 50 parts by weight of tetraethylsilicate and 3-methacryloxypropyltrimethoxy. The mixture was mixed with 48 parts by weight of silane and stirred. An exotherm was observed in about 5 minutes. After reacting for 60 minutes, the contents are transferred to another container, and methanol is added for 3 minutes.
By adding 000 parts by weight, a stockable sol solution A1 was obtained. This sol solution A1 was diluted with a methanol / ethylene glycol mixed solution (weight ratio 9/1), applied with a wheeler so that the amount of Si on the substrate was 3 mg / m ^2, and dried at 100 ° C. for 1 minute. did. As a result, similar to Example 2, there was no non-image stain at the time of printing.

Example 6 A lithographic printing plate precursor was prepared in the same manner as in Example 1 except that no infrared absorber was added. The weight after drying is 1.5 g /
m ² . The original plate was connected to an electronic typesetting machine and subjected to plate making without printing and developing with a plate making device equipped with a thermal head (TPH-293R7 manufactured by Toshiba) without printing, thereby obtaining a printing plate. This plate is trimmed to a predetermined size, and an offset printing machine (HAMADA 61, manufactured by Hamada Printing Machine Co., Ltd.) is used.
1XL, using a hard blanket) and printed on high-quality paper (the used ink was BSD offset ink, New Rubber Black Gold, with etch treatment, and the dampening solution used was a 50-fold dilution of the etchant with water) . 2
There was no background stain even after passing over 10,000 copies, and the image area could be printed clearly.

[0101]

According to the plate making method of the present invention, plate making can be performed directly by laser exposure or heating by a thermal head or the like, and no special processing such as wet development processing or rubbing after image exposure is required. Plate making is possible, and after image exposure, it can be directly mounted on a printing machine and printed. In addition, since the undegraded polymer compound is removed without remaining on the substrate surface by subjecting the substrate surface to the hydrophilic treatment, the stain property of the printed matter is significantly improved.

Claims (2)

[Claims] 1. A lithographic printing plate precursor having a layer containing a hydrophobic polymer compound whose side chain changes to hydrophilic by heat on a support whose surface has been subjected to a hydrophilic treatment, is heated image-wise, and then recorded. A method for making a lithographic printing plate, wherein the layer is removed on a printing press. 2. A lithographic printing plate precursor having a layer containing a hydrophobic polymer compound whose side chain changes to hydrophilic by heat and a light-to-heat conversion material on a support whose surface is subjected to a hydrophilic treatment is subjected to image formation by laser exposure. A method of making a lithographic printing plate, comprising exposing the exposed portion recording layer on a printing press after the exposure.