JP4524218B2 - Lithographic printing plate precursor and lithographic printing method using the same - Google Patents

Description

  The present invention relates to a lithographic printing plate precursor and a lithographic printing method using the same. Specifically, based on a digital signal from a computer or the like, for example, a so-called lithographic printing plate precursor capable of direct plate making, which can be directly made by scanning a laser having a wavelength of 300 to 1200 nm, and the lithographic printing plate precursor The present invention relates to a lithographic printing method for directly developing and printing on a printing machine without going through a development processing step.

In general, a lithographic printing plate comprises an oleophilic image area that receives ink during the printing process and a hydrophilic non-image area that receives dampening water. Lithographic printing utilizes the property that water and oil-based inks repel each other, so that the oleophilic image area of the lithographic printing plate is the ink receiving area, and the hydrophilic non-image area is dampened with the water receiving area (ink non-receiving area). In this method, a difference in ink adhesion is caused on the surface of the lithographic printing plate, and after ink is applied only to the image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support has been widely used. Normally, after exposing a lithographic printing plate precursor through an original image such as a lithographic film, the image recording layer in the image area remains, and the image recording layer in the non-image area is dissolved with an alkaline developer or an organic solvent. The lithographic printing plate is obtained by carrying out plate making by a method of exposing the surface of the hydrophilic support by removing it.

  In the conventional plate-making process of a lithographic printing plate precursor, a step of dissolving and removing the non-image area with a developing solution or the like corresponding to the image recording layer is necessary after exposure. One of the problems is to make the system unnecessary or simplified. In particular, in recent years, disposal of waste liquids discharged with wet processing has become a major concern for the entire industry due to consideration for the global environment, and therefore, the demand for solving the above-mentioned problems has become stronger.

On the other hand, as one of simple plate making methods, an image recording layer that can remove a non-image portion of a lithographic printing plate precursor in a normal printing process is used. A method called on-press development has been proposed in which a part is removed to obtain a lithographic printing plate.
As a specific method of on-press development, for example, a method of using a lithographic printing plate precursor having an image recording layer that can be dissolved or dispersed in dampening water, an ink solvent, or an emulsion of dampening water and ink , A method of mechanically removing the image recording layer by contact with rollers or a blanket cylinder of a printing press, cohesion of the image recording layer by penetration of dampening water, ink solvent, etc. There is a method in which after the adhesive force is weakened, the image recording layer is mechanically removed by contact with rollers or a blanket cylinder.
In the present invention, unless otherwise specified, the “development process step” means using a device other than a printing press (usually an automatic developing machine) and contacting a liquid (usually an alkaline developer). Refers to the step of removing the laser unexposed portion of the lithographic printing plate precursor and exposing the surface of the hydrophilic support. It refers to a method and a process for removing the laser unexposed portion of the lithographic printing plate precursor and exposing the surface of the hydrophilic support by contacting with a dampening solution.

On the other hand, in recent years, digitization techniques for electronically processing, storing, and outputting image information using a computer have become widespread, and various new image output methods corresponding to such digitization techniques have been put into practical use. It is becoming. Along with this, digitized image information is carried by high-convergence radiation such as laser light, and the lithographic printing plate precursor is scanned and exposed with that light, directly without using a lithographic film. Computer-to-plate (CTP) technology has been attracting attention. Therefore, obtaining a lithographic printing plate precursor adapted to such a technique is one of the important technical issues.

Among the lithographic printing plate precursors, the lithographic printing plate precursor capable of scanning exposure is an oleophilic photosensitive resin containing a photosensitive compound capable of generating active species such as radicals and Bronsted acids on a hydrophilic support by laser exposure. Tiers have been proposed and are already on the market. This lithographic printing plate precursor is laser-scanned based on digital information to generate active species, which causes physical or chemical changes in the photosensitive layer to insolubilize it, followed by development processing, thereby developing a negative lithographic printing plate Can be obtained. In particular, a photopolymerization type photosensitive layer containing a photopolymerization initiator excellent in photosensitive speed on a hydrophilic support, an ethylenically unsaturated compound capable of addition polymerization, and a binder polymer soluble in an alkali developer, and necessary A lithographic printing plate precursor provided with an oxygen-blocking protective layer in accordance with the printing plate having desirable printing performance due to advantages such as excellent productivity, simple development processing, and good resolution and inking properties. It can be.
Further, as an on-press developable lithographic printing plate, for example, in Patent Document 1, an image forming layer in which hydrophobic thermoplastic polymer particles are dispersed in a hydrophilic binder is provided on a hydrophilic support. A planographic printing plate precursor is described. In this Patent Document 1, the above lithographic printing plate precursor is exposed by an infrared laser, and the hydrophobic thermoplastic polymer particles are coalesced by heat to form an image, which is then mounted on a cylinder of a printing press and moistened. It is described that it is possible to perform on-press development with water and / or ink.
In this way, the method of forming an image by merging by simple thermal fusion of fine particles shows good on-press developability, but the image strength (adhesion with the support) is extremely weak and the printing durability is insufficient. Had the problem of being.

Further, a lithographic printing original plate including microcapsules encapsulating a polymerizable compound on a hydrophilic support has been proposed (see, for example, Patent Documents 2 to 3).
Furthermore, a lithographic printing plate precursor in which a photosensitive layer containing an infrared absorber, a radical polymerization initiator, and a polymerizable compound is provided on a support has been proposed (for example, see Patent Document 4).
As described above, the method using the polymerization reaction has a feature that the image strength is relatively good because the chemical bond density of the image portion is higher than that of the image portion formed by thermal fusion of the polymer fine particles. From a general point of view, all of on-press developability, printing durability and polymerization efficiency (sensitivity) are still insufficient and have not been put into practical use.
Japanese Patent No. 2938397 JP 2001-277740 A JP 2001-277742 A JP 2002-287334 A

Accordingly, an object of the present invention is to provide a lithographic printing plate precursor capable of recording an image by laser exposure.
Another object of the present invention is a lithographic printing method in which an image is recorded directly from digital data of a computer or the like using the lithographic printing plate precursor and is developed on-machine without performing a development processing step. Another object of the present invention is to provide a lithographic printing method capable of obtaining a large number of good printed materials with a sufficient amount of exposure energy.

The present invention is as follows.
1. A lithographic printing plate precursor having a laser-sensitive photopolymerization layer on a hydrophilic support and capable of forming an image without alkali development, wherein the side chain is represented by the following formula (3): A lithographic printing plate precursor comprising a polymer compound having a group and a polymer compound containing a (meth) acrylate unit in which at least one of the groups shown in the following group A is bonded to an ester .

In formula (3), c is an integer of 2 to 7, and n represents an integer of 1 to 100.

2. 2. The lithographic printing plate precursor as described in 1 above, wherein the polymer compound contains a group represented by the formula (3).
3. 3. The lithographic printing plate precursor as described in 1 or 2 above, wherein the polymer compound has a glass transition temperature Tg of 90 ° C. or lower.
4). 4. The lithographic printing plate precursor as described in any one of 1 to 3 above, wherein the photopolymerization layer contains microcapsules.
5. The lithographic printing plate precursor as described in any one of 1 to 4 above, wherein the photopolymerization layer further contains an infrared absorber, a polymerization initiator, and a polymerizable compound.

6). The lithographic printing plate precursor according to any one of 1 to 5 above is mounted on a printing press and imagewise laser-exposed, or after imagewise exposure with a laser and then mounted on a printing press, the lithographic printing A lithographic printing method in which printing ink and fountain solution are supplied to a plate precursor to remove a laser unexposed portion of the photopolymerized layer and print.
Although this invention is invention concerning said 1-6, hereafter, other matters are also demonstrated.

  In the present invention, by using a polymer compound having a specific ether group, ester group or amide group in the molecule as the binder polymer, the glass transition temperature (hereinafter simply referred to as Tg as appropriate) is relatively low. Is 90 ° C. or lower, so that the formed film has flexibility and low mechanical strength, so it is presumed that the film is rapidly developed. On the other hand, in the exposed area, the mobility of radicals generated during the exposure is improved and the polymerization proceeds efficiently. As a result, a cured film having a high crosslinking density can be formed in the exposed area. Formation of fountain solution penetration path due to penetration of dampening water during development and elution of other components (such as ethylenically unsaturated compounds and radical polymerization initiators) in the cured film is effectively suppressed, and the dynamics of the cured film It is assumed that the strength can be maintained.

  According to the present invention, it is possible to provide a lithographic printing plate precursor having excellent on-press developability, fine line reproducibility and printing durability, and a lithographic printing method using the same.

Hereinafter, the present invention will be described in detail.
The lithographic printing plate precursor according to the invention is premised on having a laser-sensitive photopolymerization layer on a hydrophilic support. Hereinafter, the components of the photopolymerization layer will be described.
<Photopolymerization layer>
[Binder polymer]
In the present invention, a polymer compound having at least one of an ether group, an ester group and an amide group in the molecule as a binder polymer, specifically, in the side chain, for improving the film properties and on-press developability of the photopolymerization layer (Hereinafter, referred to as a specific polymer compound as appropriate).
In the present invention, the specific polymer compound preferably has an ether group.
The ether group-containing polymer compound is preferably a polymer compound having an ether group represented by the following formula (1).

  In formula (1), R represents a hydrogen atom or a methyl group, a is 1, 3 or 5, and 1 represents an integer of 1 to 100. l is preferably an integer of 1 to 9, more preferably an integer of 1 to 8, more preferably an integer of 1 to 7, still more preferably an integer of 1 to 6, particularly preferably an integer of 1 to 4, Preferably it is 2.

The specific polymer compound of the present invention preferably has a glass transition temperature (Tg) of 90 ° C. or lower.
Here, “glass transition temperature” (Tg) is defined as “polymer chemistry” (Kyoritsu Shuppan, published in 1993) and is 2 2 when the specific volume of a polymer substance is measured as a function of temperature. It refers to the temperature corresponding to the intersection of the straight lines of the book, and adopts a value measured by a differential scanning calorimeter (DSC).
As the polymer compound of the present invention, those having a Tg of 90 ° C. or lower are preferable, and those having a Tg of less than 70 ° C. are more preferable from the viewpoint of improving on-press developability and improving polymerization efficiency by exposure. Moreover, although there is no restriction | limiting in particular in the minimum of Tg, -50 degreeC or more is preferable from a viewpoint of storage stability.
Regarding the polymer compound according to the present invention, in order to set Tg to a desired value, a functional group having a linear partial structure may be introduced into the structural unit constituting the polymer compound, or one or Such a functional group may be introduced into any one of two or more structural units depending on the purpose. For this reason, the main chain structure of the polymer compound according to the present invention is not particularly limited. Preferable examples of the main chain structure include poly (meth) acrylic resins, polyurethane resins, acetal-modified products of polyvinyl resins, etc. Among them, poly (meth) acrylic resins from the viewpoint of printing performance such as ink setting properties. Resins are preferred. Therefore, in order to reduce the Tg of the polymer compound having such a poly (meth) acrylic main chain structure to 90 ° C. or less, the polymer compound has the structural unit represented by the general formula (1) as a side chain. It is necessary to contain. In this case, a plurality of different structural units may be contained.

  The specific polymer compound of the present invention may have an ether group other than the ether group represented by the above formula (1).

The specific polymer compound of the present invention may be copolymerized with a radically polymerizable compound having a hydrophilic group in order to improve various performances such as on-press developability. Such a hydrophilic group is preferably not an alkali-soluble group, and examples thereof include an amide group, a hydroxyl group, and an onium base, and an amide group and a hydroxyl group are preferable. Specific examples of the radical polymerizable compound having a hydrophilic group include, for example, acrylamide, methacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N-vinylpyrrolidone, N-vinylacetamide, N-acryloylmorpholine, 2 -Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate are mentioned. These may be used alone or in combination of one or more. The content of these copolymer components is preferably 0 to 85 mol%, particularly preferably 5 to 70 mol%.

  The specific polymer compound of the present invention is used for the purpose of improving various performances such as image strength, and in addition to the above-mentioned radical polymerizable compound, in addition to the above-mentioned radical polymerizable compound, other radical polymerizable compounds may be used. Polymerization is also a preferred embodiment. Examples of the radical polymerizable compound that can be copolymerized with the specific polymer compound in the present invention include acrylic acid esters, methacrylic acid esters, N, N-2 substituted acrylamides, and N, N-2 substituted methacrylamides. Radical polymerizable compounds selected from styrene, styrenes, acrylonitriles, methacrylonitriles, and the like.

Specifically, for example, acrylic esters such as alkyl acrylate (the alkyl group preferably has 1 to 20 carbon atoms), (specifically, for example, methyl acrylate, ethyl acrylate, acrylic Propyl acrylate, butyl acrylate, amyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate , Pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.), aryl acrylate (for example, phenyl acrylate) Methacrylic acid esters (e.g., methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl). Methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, Glycidyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.), Ally Methacrylates (e.g. phenyl methacrylate, cresyl methacrylate, naphthyl methacrylate, etc.), styrene and styrene derivatives, e.g. alkyl styrenes (e.g. methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl) Styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, etc.), alkoxy styrene (for example, methoxy styrene, 4-methoxy-3-methyl styrene, dimethoxy styrene, etc.) Halogen styrene (e.g. chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, (N-chlorostyrene, prom styrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, etc.), acrylonitrile, methacrylo A nitrile etc. are mentioned.

Among these radically polymerizable compounds, acrylic acid esters, methacrylic acid esters, and styrenes are preferably used. These can be used alone or in combination of two or more. The content of these copolymerization components used is preferably 0 to 95 mol%, particularly preferably 20 to 90 mol%.

The specific polymer compound of the present invention is an ester group represented by the following formula (2) or the following formula (
The amide group represented by 3) may be present in the molecule.

  In the formula, b is an integer of 2 to 5, c is an integer of 2 to 7, and m and n each independently represents an integer of 1 to 100.

The specific polymer compound according to the present invention may be a homopolymer, but the radically polymerizable compounds having groups represented by different general formulas (1), (2) or (3), or the general formula (1) In the case of a copolymer of one or more radically polymerizable compounds having the group represented by (2) or (3) and one or more of the other radically polymerizable compounds described above, Any of a block copolymer, a random copolymer, and a graft copolymer may be used.

Examples of the solvent used for synthesizing such a polymer compound include ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxy. Examples include ethyl acetate, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, toluene, ethyl acetate, methyl lactate, and ethyl lactate. It is done. These solvents may be used alone or in combination of two or more.

  The specific polymer compound according to the present invention has a mass average molecular weight Mw, preferably 2,000 or more, and more preferably 5,000 to 300,000. Moreover, the specific polymer compound according to the present invention may contain an unreacted monomer. In this case, the proportion of the monomer in the polymer compound is desirably 15% by mass or less. The content of the specific polymer compound contained in the photopolymerization layer of the present invention is preferably about 5 to 95% by mass, more preferably about 10 to 85% by mass in terms of solid content. Within this range, good image area strength and image formability can be obtained.

  Specific examples of the constitutional unit of the specific polymer compound used as the binder polymer in the present invention are shown below, but are not limited thereto.

Next, each component other than the binder polymer in the photopolymerization layer used in the lithographic printing plate precursor according to the invention will be described.

[Infrared absorber]
When forming an image of the lithographic printing plate precursor according to the invention with a laser light source that emits infrared rays of 760 to 1200 nm, for example, it is preferable to contain an infrared absorber in the photopolymerization layer. The infrared absorber has a function of converting absorbed infrared rays into heat. With the heat generated at this time, a polymerization initiator (radical generator) described later is thermally decomposed to generate radicals. Examples of the infrared absorbent used in the present invention include dyes or pigments having an absorption maximum at a wavelength of 760 to 1200 nm.

As the dye used as the infrared absorber, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, etc. Is mentioned.
Examples of preferable dyes include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, 58-181690, JP-A-58-194595, etc., methine dyes, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59- No. 73996, JP-A-60-52940, JP-A-60-63744 and the like, Naphthoquinone dyes described in JP-A-58-112792, etc., British Patent 434,875 And cyanine dyes.

Also, 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, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. . Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).
Other preferable examples of the infrared absorbing dye of the present invention include specific indolenine cyanine dyes described in JP-A-2002-278057 as exemplified below.

  Particularly preferred among these dyes are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferable, and one particularly preferable example is a cyanine dye represented by the following general formula (i).

During formula (i), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below.

X a ^_- is Z _a which will be described below ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, a halogen atom.
X ² represents an oxygen atom, a nitrogen atom, or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or a carbon atom having 1 to 12 carbon atoms including a hetero atom. Indicates a hydrogen group. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se.

R ¹ and R ² in the general formula (i) each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the photopolymerization layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring. Alternatively, it is particularly preferable that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Z _a ^- represents a counter anion. However, when the cyanine dye represented by formula (i) has an anionic substituent in the structure thereof, Z _a is does not require charge neutralization ^_- is not necessary. Preferred Z _a ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, from the storage stability of the photopolymerization layer coating solution. , Hexafluorophosphate ions, and aryl sulfonate ions.

Specific examples of the cyanine dye represented by formula (i) that can be suitably used in the present invention include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. be able to.
Further, other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057 described above.

  Examples of the pigment used in the present invention include commercially available pigments and color index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technology Association, published in 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986), “Printing Ink Technology”, CMC Publishing, 1984) can be used.

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

  These pigments may be used without surface treatment or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Yokoshobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  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. Within this range, good stability of the pigment dispersion in the photopolymerization layer coating solution and good uniformity of the photopolymerization layer can be obtained.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

These infrared absorbers may be added to the same layer as other components, or may be added to another layer, but when the lithographic printing plate precursor is prepared, the photopolymerization layer It adds so that the light absorbency in the maximum absorption wavelength in the wavelength range of 760 nm-1200 nm may be in the range of 0.3-1.2 by the reflection measurement method. Preferably, it is the range of 0.4-1.1. Within this range, a uniform polymerization reaction proceeds in the depth direction of the photopolymerization layer, and good film strength of the image area and adhesion to the support can be obtained.
The absorbance of the photopolymerization layer can be adjusted by the amount of the infrared absorber added to the photopolymerization layer and the thickness of the photopolymerization layer. The absorbance can be measured by a conventional method. As a measuring method, for example, on a reflective support such as aluminum, a photopolymerization layer having a thickness appropriately determined in a range in which the coating amount after drying is necessary as a lithographic printing plate is formed, and the reflection density is determined as the optical density. And a method of measuring with a spectrophotometer by a reflection method using an integrating sphere.

(Polymerization initiator)
As a polymerization initiator used in the photopolymerization layer of the present invention, various photopolymerization initiators known in patents, literatures, etc., or a combination system of two or more photopolymerization initiators depending on the wavelength of the light source used ( Photopolymerization initiation system) can be appropriately selected and used.

In the case of using a blue semiconductor laser, Ar laser, second harmonic of an infrared semiconductor laser, or SHG-YAG laser as a light source, various photopolymerization initiators (systems) have been proposed. Certain photoreducible dyes described in the specification of 850,445, such as rose bengal, eosin, erythrosine, etc., or a combination of a dye and an initiator, such as a complex initiator system of a dye and an amine (Japanese Patent Publication No. 44) -20099), a combination system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. 45-37377), a system of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication No. 4)
7-2528, JP 54-155292), cyclic cis-α-dicarbonyl compound and dye system (JP 48-84183), cyclic triazine and merocyanine dye system (JP A). 54-151024), 3-ketocoumarin and activator systems (Japanese Patent Laid-Open Nos. 52-112681, 58-15503), biimidazole, styrene derivatives, and thiol systems (Japanese Patent Laid-Open No. 140203), organic peroxides and dyes (Japanese Patent Laid-Open Nos. 59-1504, 59-140203, 59-189340, 62-174203, Japanese Patent Publication No. 62-1641, US Pat. No. 4,766,055), a system of a dye and an active halogen compound (Japanese Patent Laid-Open Nos. 63-1718105 and 63-2) 8903, JP-A-3-264771, etc.), dye and borate compounds (JP-A-62-143044, JP-A-62-1050242, JP-A-64-13140) JP 64-13141, JP 64-13142, JP 64-13143, JP 64-13144, JP 64-17048, JP 1-222903 , JP-A-1-298348, JP-A-1-138204, etc.), a system comprising a dye having a rhodanine ring and a radical generator (JP-A-2-17943, JP-A-2-244050), titanocene, 3-ketocoumarin dye system (Japanese Patent Laid-Open No. 63-221110), titanocene and xanthene dyes, additions containing amino groups or urethane groups A combination of polymerizable ethylenically unsaturated compounds (JP-A-4-221958, JP-A-4-219756), titanocene and a specific merocyanine dye system (JP-A-6-295061), titanocene Examples thereof include a dye system having a benzopyran ring (JP-A-8-334897).

  In the photopolymerization layer (photosensitive layer or image recording layer) of the lithographic printing plate precursor according to the invention, a particularly preferred photopolymerization initiator (system) contains at least one titanocene. The titanocene compound used as a photopolymerizable initiator (system) in the present invention may be any titanocene compound that can generate an active radical when irradiated with light in the presence of a sensitizing dye described later. For example, JP 59-152396 A, JP 61-151197 A, JP 63-41483 A, JP 63-41484 A, JP 2-249 A, and JP 2 -291, JP-A-3-27393, JP-A-3-12403, and JP-A-6-41170 can be appropriately selected and used.

  More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5 , 6-pentafluorophen-1-yl (hereinafter also referred to as “T-1”), di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di- -Cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-cyclo Pentadienyl-Ti-bis-2,4-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl Di-methylcyclopentadie Ru-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclo And pentadienyl) -bis (2,6-difluoro-3- (pyr-1-yl) phenyl) titanium (hereinafter also referred to as “T-2”).

  These polymerization initiators can be further subjected to various chemical modifications for improving the characteristics of the photosensitive layer. For example, bonding with sensitizing dyes, addition polymerizable unsaturated compounds and other radical generating parts, introduction of hydrophilic sites, compatibility improvement, introduction of substituents to suppress crystal precipitation, introduction of substituents to improve adhesion A method such as polymerization can be used.

  The use method of these titanocene compounds can be arbitrarily set arbitrarily according to the performance design of the lithographic printing plate precursor as in the later-described addition polymerizable compound. For example, by using two or more kinds in combination, the compatibility with the photosensitive layer can be increased. A larger amount of the photopolymerization initiator such as the titanocene compound is usually advantageous in terms of photosensitivity, and is 0.5 to 80 parts by mass, preferably 1 to 100 parts by mass of the nonvolatile component of the photosensitive layer. Sufficient photosensitivity can be obtained by using in the range of 50 parts by mass. On the other hand, when used under a white light such as yellow, it is preferable that the amount of titanocene used is small from the viewpoint of fogging by light near 500 nm, but the amount of titanocene used in combination with a sensitizing dye is the total solid content. Sufficient photosensitivity can be obtained even if it is lowered to 6 parts by mass or less, further 1.9 parts by mass or less, and further 1.4 parts by mass or less with respect to 100 parts by mass.

As the thermal polymerization initiator used in the present invention for initiating and advancing the curing reaction of the post-addition polymerizable compound, a thermal decomposition type radical generator that decomposes by heat to generate radicals is useful. Such radical generators are used in combination with the above-mentioned infrared absorbers, and when the infrared laser is irradiated, the infrared absorbers generate heat and generate radicals by the heat. Recording is possible by combining these. It becomes.
Examples of the radical generator include onium salts, triazine compounds having a trihalomethyl group, peroxides, azo polymerization initiators, azide compounds, quinonediazides, oxime ester compounds, triaryl monoalkylborate compounds, etc. Or an oxime ester compound has high sensitivity and is preferable. Below, the onium salt which can be used suitably as a polymerization initiator in this invention is demonstrated. Preferred onium salts include iodonium salts, diazonium salts, and sulfonium salts. In the present invention, these onium salts function not as acid generators but as radical polymerization initiators. The onium salt suitably used in the present invention is an onium salt represented by the following general formulas (A) to (C).

In general formula (A), Ar ¹¹ and Ar ¹² each independently represent an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a carbon atom having 12 or less carbon atoms. An aryloxy group is mentioned. Z ¹¹⁻ represents a counter ion selected from the group consisting of a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a carboxylate ion, and a sulfonate ion, preferably a perchlorate ion, Hexafluorophosphate ions, carboxylate ions, and aryl sulfonate ions.

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

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

  In the present invention, specific examples of onium salts that can be suitably used as a polymerization initiator (radical generator) include those described in JP-A-2001-133696. In the present invention, onium salts represented by general formula (A) ([OI-1] to [OI-10]) and onium salts represented by general formula (B) ([ON] which can be suitably used in the present invention are shown below. -1] to [ON-5]), and specific examples of the onium salts ([OS-1] to [OS-7]) represented by the general formula (C), are not limited thereto. .

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

Other preferable polymerization initiators include specific aromatic sulfonium salts described in Japanese Patent Application No. 2000-266797, Japanese Patent Application No. 2001-177150, Japanese Patent Application No. 2000-160323, and Japanese Patent Application No. 2000-184603.
Below, the typical compound of the other preferable polymerization initiator which can be applied to this invention is illustrated.

  Moreover, the oxime ester compound which can be used suitably as a polymerization initiator in this invention is demonstrated below. Preferred oxime ester compounds include compounds represented by the following general formula (D).

In general formula (D), X represents a carbonyl group, a sulfone group, or a sulfoxide group, and Y represents a cyclic or chain alkyl group having 1 to 12 carbon atoms, an alkenyl group, an alkynyl group, or an aryl group having 6 to 18 carbon atoms. A heterocyclic group, an aryl group is an aromatic hydrocarbon compound such as a benzene ring, naphthalene ring, anthracene ring, phenanthrene group, pyrene group, triphenylene group, and a heterocyclic ring is a nitrogen atom, sulfur atom, oxygen atom For example, pyrrole group, furan group, thiophene group, selenophene group, pyrazole group, imidazole group, triazole group, tetrazole group, oxazole group, thiazole group, indole group, benzofuran. Group, benzimidazole group, benzoxazole group, benzothiazole group, pyridine group, Spermidine group, a pyrazine group, a triazine group, a quinoline group, a carbazole group, an acridine group, a phenoxazine, and a compound such as phenothiazine. Examples of these substituents represented by Y include halogen atoms, hydroxyl groups, nitrile groups, nitro groups, carboxyl groups, aldehyde groups, alkyl groups, thiol groups, aryl groups, alkenyl groups, alkynyl groups, ether groups, ester groups, ureas. Group, amino group, amide group, sulfide group, disulfide group, sulfoxide group, sulfo group, sulfone group, hydrazine group, carbonyl group, imino group, halogen atom, hydroxyl group, nitrile group, nitro group, carboxyl group, carbonyl group, urethane Group, alkyl group, thiol group, aryl group, phosphoroso group, phospho group, carbonyl ether group and the like.

  Z in the general formula (D) is synonymous with Y or is a nitrile group, a halogen atom, a hydrogen atom, or an amino group. These Z are a halogen atom, a hydroxyl group, a nitrile group, a nitro group, a carboxyl group, an aldehyde group, an alkyl group. Group, thiol group, aryl group, alkenyl group, alkynyl group, ether group, ester group, urea group, amino group, amide group, sulfide group, disulfide group, sulfoxide group, sulfo group, sulfone group, hydrazine group, carbonyl group, Substitution is possible with imino group, halogen atom, hydroxyl group, nitrile group, nitro group, carboxyl group, carbonyl group, urethane group, alkyl group, thiol group, aryl group, phosphoro group, phospho group, carbonyl ether group and the like.

  W in the general formula (D) represents a divalent organic group, and represents a methylene group, a carbonyl group, a sulfoxide group, a sulfone group, or an imino group. The methylene group and the imino group are an alkyl group, an aryl group, an ester group, and a nitrile. It can be substituted with a group, a carbonyl ether group, a sulfo group, a sulfo ether group, an ether group or the like. n represents an integer of 0 or 1.

V in the general formula (D) is a C1-C12 cyclic or chain alkyl group, alkenyl group, alkynyl group, C6-C18 aryl group, alkoxy group or aryloxy group. Aromatic hydrocarbon compounds such as benzene ring, naphthalene ring, anthracene ring, phenanthrene group, pyrene group, triphenylene group, pyrrole group, furan group, thiophene group, selenophene group, pyrazole group, imidazole group, triazole group, tetrazole group, oxazole Group, thiazole group, indole group, benzofuran group, benzimidazole group, benzoxazole group, benzothiazole group, pyridine group, pyrimidine group, pyrazine group, triazine group, quinoline group, carbazole group, acridine group, phenoxazine, phenothiazine, etc. Heteroatom containing Aromatic compounds and the like. These V are halogen atoms, hydroxyl groups, nitrile groups, nitro groups, carboxyl groups, aldehyde groups, alkyl groups, thiol groups, aryl groups, alkenyl groups, alkynyl groups, ether groups, ester groups, urea groups, amino groups, amide groups, Sulfide group, disulfide group, sulfoxide group, sulfo group, sulfone group, hydrazine group, carbonyl group, imino group, halogen atom, hydroxyl group, nitrile group, nitro group, carboxyl group, carbonyl group, urethane group, alkyl group, thiol group, Substitution is possible with an aryl group, phosphoro group, phospho group, carbonyl ether group or the like.
V and Z may be bonded to each other to form a ring.

As the oxime ester compound represented by the general formula (D), from the viewpoint of sensitivity, X is carbonyl, Y is an aryl group or benzoyl group, Z group is an alkyl group or aryl group, W is a carbonyl group, V Is preferably an aryl group. More preferably, the aryl group of V has a thioether substituent.
Note that the structure of the N—O bond in the general formula (D) may be E-form or Z-form.

  Other oxime ester compounds that can be suitably used in the present invention include Progress in Organic Coatings, 13 (1985) 123-150; C. S Perkin II (1979) 1653-1660; Journal of Photopolymer Science and Technology (1995) 205-232; C. S Perkin II (1979) 156-162; JP-A 2000-66385; JP-A 2000-80068.

  Although the specific example of the oxime ester compound which can be used suitably for this invention is shown below, it is not limited to this.

  These polymerization initiators are from 0.1 to 50% by mass, preferably from 0.5 to 30% by mass, based on the total solid content constituting the photopolymerization layer, from the viewpoint of sensitivity and non-image area stains that occur during printing. %, Particularly preferably 1 to 20% by mass. These polymerization initiators may be used alone or in combination of two or more. Moreover, these polymerization initiators may be added to the same layer as other components, or another layer may be provided and added thereto.

[Sensitizing dye]
In the lithographic printing plate precursor according to the invention, the photopolymerization layer may contain a sensitizing dye. The sensitizing dye preferably has an absorption peak at 350 to 850 nm. Examples of such sensitizing dyes include spectral sensitizing dyes and the following dyes or pigments that absorb light from a light source and interact with a polymerization initiator.
Preferred spectral sensitizing dyes or dyes include polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thianes). Carbocyanine, oxacarbocyanine), merocyanines (eg, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), phthalocyanines (
For example, phthalocyanine, metal phthalocyanine), porphyrins (eg, tetraphenylporphyrin, central metal substituted porphyrin), chlorophylls (eg, chlorophyll, chlorophyllin, central metal substituted chlorophyll), metal complexes, anthraquinones (eg, anthraquinone), squalium (For example, squalium) and the like.

  Examples of more preferable spectral sensitizing dyes or dyes include styryl dyes described in JP-B-37-13034, cationic dyes described in JP-A-62-143044, and quinoxalinium described in JP-B-59-24147. Salts, new methylene blue compounds described in JP-A No. 64-33104, anthraquinones described in JP-A No. 64-56767, benzoxanthene dyes described in JP-A No. 2-1714, JP-A No. 2-226148 and special Acridines described in the respective publications of Kaihei 2-226149, pyrylium salts described in Japanese Patent Publication No. 40-28499, cyanines described in Japanese Patent Publication No. 46-42363, benzofuran dyes described in Japanese Unexamined Patent Publication No. 2-63053, Conjugated ketone dyes described in JP-A-2-85858 and JP-A-2-216154 57-10605 described in JP-dye. Azocinnamylidene derivatives described in JP-B-2-30321, cyanine dyes described in JP-A-1-287105, JP-A-62-31844, JP-A-62-31848, JP-A-62-143043 Xanthene dyes described in Japanese Patent Publication Nos. JP-A-59-28325, merocyanine dyes described in JP-B-61-9621, dyes described in JP-A-2-17943, JP-A-2-244050 Merocyanine dyes described in JP-A-59-28326, merocyanine dyes described in JP-A-59-89803, merocyanine dyes described in JP-A-8-129257, and JP-A-8-334897 Benzopyran dyes, and the like.

  As content of a sensitizing dye, Preferably it is 0.1-50 mass% with respect to the total solid which comprises a photopolymerization layer, More preferably, it is 0.5-30 mass%, Most preferably, it is 1-20 mass%. It is.

[Polymerizable compound]
The polymerizable compound that can be used in the photopolymerization layer of the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and has at least one ethylenically unsaturated bond, preferably two or more. It is chosen from the compound which has. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids. An ester of an acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable.
As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer, isocyanuric acid There are EO-modified triacrylate and the like.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

  Examples of other esters include, for example, aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, and JP-A-59-5241. Those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Furthermore, the ester monomers described above can also be used as a mixture.

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

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

_{CH 2 = C (R 4)} COOCH 2 CH (R 5) OH (III)
(However, R ₄ and R ₅ represent H or CH _3. )

  Further, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56-17654 Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable. Furthermore, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, JP-A-1-105238 Can obtain a photopolymerizable composition having an excellent photosensitive speed.

  Other examples include reacting polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. And polyfunctional acrylates and methacrylates such as epoxy acrylates. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid compounds described in JP-A-2-25493 are also included. be able to. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

  About these polymerizable compounds, the details of usage such as the structure, single use or combination, addition amount, etc. can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.

  From the viewpoint of sensitivity, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable. Further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrenic compound, vinyl ether type). A method of adjusting both sensitivity and strength by using a compound) is also effective.

  Further, the selection and use method of the addition polymerization compound is also an important factor for the compatibility and dispersibility with other components in the photopolymerization layer (for example, binder polymer, initiator, colorant, etc.). In some cases, the compatibility can be improved by using a low-purity compound or by using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving the adhesion of the substrate and an overcoat layer described later.

  The polymerizable compound is preferably used in the range of 5 to 80% by mass, more preferably 25 to 75% by mass with respect to the non-volatile component in the photopolymerization layer. These may be used alone or in combination of two or more. In addition, the use method of the addition polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface adhesiveness, etc. Depending on the case, a layer configuration and coating method such as undercoating and overcoating can be performed.

  In the present invention, several modes can be used as a method for causing the photopolymerization layer to contain the above-mentioned photopolymerization layer constituents and other constituents described later. One is a molecular dispersion type image recording layer in which the constituent components are dissolved and applied in an appropriate solvent as described in, for example, JP-A-2002-287334. In another embodiment, as described in, for example, JP-A Nos. 2001-277740 and 2001-277742, all or a part of the constituent components are encapsulated in microcapsules and contained in the image recording layer. It is a capsule type image recording layer. further. In the microcapsule type image recording layer, the constituent component may be contained outside the microcapsule. Here, it is preferable that the microcapsule-type image recording layer includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule. In order to obtain better on-press developability, the image recording layer is preferably a microcapsule type image recording layer.

  As a method for microencapsulating the above photopolymerization layer constituent components, known methods can be applied. For example, as a method for producing microcapsules, a method using coacervation found in U.S. Pat. Nos. 2,800,547 and 2,800,498, U.S. Pat. No. 3,287,154, JP-B-38-19574, 42-446 by the interfacial polymerization method, US Pat. No. 3,418,250, US Pat. No. 3,660,304 by polymer precipitation method, US Pat. No. 3,796,669, isocyanate polyol A method using a wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, and a urea-formaldehyde system found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802. Or urea formaldehyde-resorcinol A method using a wall forming material, a method using a wall material such as melamine-formaldehyde resin, hydroxycellulose, etc. found in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method by monomer polymerization, spray drying method found in British Patent No. 930422, US Pat. No. 3,111,407, electrolytic dispersion cooling method seen in British Patent Nos. 952807, 967074, etc. However, it is not limited to these.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. Moreover, you may introduce | transduce into the microcapsule wall the compound which has crosslinkable functional groups, such as the said ethylenically unsaturated bond which can introduce | transduce the binder polymer.

  The average particle size of the microcapsules is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is further more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, good resolution and stability over time can be obtained.

[Other additives]
In the photopolymerization layer in the present invention, components other than those described above, for example, surfactants, colorants, print-out agents, polymerization inhibitors (thermal polymerization inhibitors), higher fatty acid derivatives, plasticizers, inorganic fine particles, low molecules A hydrophilic compound or the like can be contained. Such an additive can be added to the photopolymerization layer in a molecular dispersion state, but can be encapsulated in a microcapsule together with the polymerizable compound as necessary.

<Surfactant>
In the present invention, the photopolymerization layer has an on-press developability at the start of printing, and
In order to improve the coated surface state, it is preferable to use a surfactant. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorosurfactants. Surfactant may be used independently and may be used in combination of 2 or more type.

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

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

The cationic surfactant used in the present invention is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.
The amphoteric surfactant used in the present invention is not particularly limited, and conventionally known amphoteric surfactants can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric acid esters, and imidazolines.

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

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

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 5% by mass with respect to the total solid content of the photopolymerization layer.

<Colorant>
In the present invention, 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 an image colorant. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc. And dyes described in No. 293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, etc. can be suitably used.
These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. In addition, the addition amount has a preferable ratio of 0.01-10 mass% with respect to the total solid of a photopolymerization layer.

<Bakeout agent>
In the photopolymerization layer of the present invention, a compound that is discolored by an acid or a radical can be added in order to generate a printout image. As such a compound, for example, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used.

Specific examples include brilliant green, ethyl violet, methyl green, crystal violet, basic fuchsin, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange, paramethyl red, Congo Fred, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A, Methyl Violet, Malachide Green, Parafuchsin, Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.], Oil Blue # 603 [Orient Chemical Kogyo Co., Ltd.], Oil Pink # 312 [Orient Chemical Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Gaku Kogyo Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.], Oil Red RR [Orient Chemical Co., Ltd.], Oil Green # 502 [Orient Chemical Co., Ltd.], Spiron Red BEH Special [made by Hodogaya Chemical Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p- Diethylaminophenyliminonaphthoquinone, 2-carboxystearylamino-4-pN, N-bis (hydroxyethyl) amino-phenyliminonaphthoquinone, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4- - dyes and p of diethylamino phenyl imino-5-pyrazolone, p ', p "- hexamethyl triamnotriphenylmethane (leuco crystal violet), and a leuco dye such as Pergascript Blue SRB (manufactured by Ciba-Geigy).

In addition to the above, a leuco dye known as a material for thermal paper or pressure-sensitive paper is also suitable. Specific examples include crystal violet lactone, malachite green lactone, benzoyl leucomethylene blue, 2- (N-phenyl-N-methylamino) -6- (Np-tolyl-N-ethyl) amino-fluorane, 2-anilino. -3-methyl-6- (N-ethyl-p-toluidino) fluorane, 3,6-dimethoxyfluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) ) -Fluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane, 3 -(N, N-diethylamino) -6-methyl-7-xylidinofluorane, 3- (N, N-diethylamino) -6-methyl-7-chloro Fluorane, 3- (N, N-diethylamino) -6-methoxy-7-aminofluorane, 3- (N, N-diethylamino) -7- (4-chloroanilino) fluorane, 3- (N, N-diethylamino) -7-chlorofluorane, 3- (N, N-diethylamino) -7-benzylaminofluorane, 3- (N, N-diethylamino) -7,8-benzofluorane, 3- (N, N-dibutyl) Amino) -6-methyl-7-anilinofluorane, 3- (N, N-dibutylamino) -6-methyl-7-xylidinofluorane, 3-piperidino-6-methyl-7-anilinofluorane 3-pyrrolidino-6-methyl-7-anilinofluorane, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis (1-n-butyl- -Methylindol-3-yl) phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl- 2-methylindol-3-yl) -4-phthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, and the like.

  A suitable addition amount of the dye that changes color by an acid or a radical is 0.01 to 10% by mass with respect to the total solid content of the photopolymerization layer.

<Polymerization inhibitor>
A small amount of a thermal polymerization inhibitor is preferably added to the photopolymerization layer of the present invention in order to prevent unnecessary thermal polymerization of the radical polymerizable compound during the production or storage of the photopolymerization layer.
Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4-thiobis (3-methyl-6-t-butylphenol). ), 2,2-methylenebis (4-methyl-6-tert-butylphenol), and N-nitroso-N-phenylhydroxylamine aluminum salt.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the photopolymerization layer.

<Higher fatty acid derivatives, etc.>
In order to prevent polymerization inhibition due to oxygen, a higher fatty acid derivative such as behenic acid or behenamide is added to the photopolymerization layer of the present invention, and the surface of the photopolymerization layer is dried during the coating process. It may be unevenly distributed. The amount of the higher fatty acid derivative added is preferably about 0.1 to about 10% by mass with respect to the total solid content of the photopolymerization layer.

<Plasticizer>
The photopolymerizable layer of the present invention may contain a plasticizer in order to improve on-press developability.
Examples of the plasticizer include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate; Glycol esters such as glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate Diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioct Ruazereto, aliphatic dibasic acid esters such as dibutyl maleate; polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate in.
The plasticizer content is preferably about 30% by mass or less based on the total solid content of the photopolymerization layer.

<Inorganic fine particles>
The photopolymerizable layer of the present invention may contain inorganic fine particles in order to improve the strength of the cured film in the image area and to improve the on-press developability of the non-image area.
As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate or a mixture thereof can be preferably mentioned. Even if they are not photothermally convertible, they can be used for strengthening the film, enhancing interfacial adhesion by surface roughening, and the like.
The inorganic fine particles preferably have an average particle size of 5 nm to 10 μm, and more preferably 0.5 μm to 3 μm. Within the above range, it is possible to form a non-image portion having excellent hydrophilicity, which is stably dispersed in the photopolymerization layer, sufficiently retains the film strength of the photopolymerization layer, and hardly causes stains during printing.
The inorganic fine particles as described above can be easily obtained as a commercial product such as a colloidal silica dispersion.
The content of the inorganic fine particles is preferably 40% by mass or less, and more preferably 30% by mass or less, based on the total solid content of the photopolymerization layer.

<Low molecular hydrophilic compound>
The photopolymerizable layer of the present invention may contain a hydrophilic low molecular compound for improving on-press developability. Examples of hydrophilic low-molecular compounds include water-soluble organic compounds such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and salts thereof, organic phosphonic acids such as phenylphosphonic acid and the like Examples thereof include organic carboxylic acids such as salts thereof, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid and amino acids, and salts thereof.

<Formation of photopolymerization layer>
The photopolymerization layer of the present invention is applied by preparing a coating solution by dispersing or dissolving the necessary components described above in a solvent. Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The photopolymerization layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeating a plurality of coating and drying operations.

Moreover, although the photopolymerization layer coating amount (solid content) on the support obtained after coating and drying varies depending on the application, it is generally preferably 0.3 to 3.0 g / m ² . Within this range, good sensitivity and good film properties of the image recording layer can be obtained.
Various methods can be used as the coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

<Support>
The support used for the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. Preferable supports include a polyester film and an aluminum plate. Among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

  The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is preferably 10% by mass or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element. The composition of the aluminum plate is not specified, and a publicly known material can be used as appropriate.

  The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm.

  Prior to using the aluminum plate, it is preferable to perform surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it becomes easy to improve hydrophilicity and secure adhesion between the photopolymerization layer and the support. Prior to the roughening treatment of the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like for removing rolling oil on the surface is performed as desired.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (electrochemical surface roughening treatment that dissolves the surface), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Also, a transfer method in which the uneven shape is transferred with a roll provided with unevenness in the aluminum rolling step may be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The conditions of anodizing treatment vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, an electrolyte concentration of 1 to 80% by mass solution, a liquid temperature of 5 to 70 ° C., a current density of 5 to 60 A / d m ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2. Within this range, good printing durability and good scratch resistance of the non-image area of the lithographic printing plate can be obtained.

<Sealing treatment>
As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation, and the like. If necessary, the surface of the anodized film described in JP-A-2001-253181 and JP-A-2001-322365 may be subjected to a micropore expansion process, a sealing process, and a surface immersed in an aqueous solution containing a hydrophilic compound. A hydrophilic treatment or the like can be appropriately selected and performed. Of course, the enlargement process and the sealing process are not limited to those described above, and any conventionally known method can be performed.
For example, as the sealing treatment, in addition to the vapor sealing, a single treatment with fluorinated zirconic acid, a treatment with sodium fluoride, or a vapor sealing with addition of lithium chloride is possible.

The sealing treatment used in the present invention is not particularly limited, and a conventionally known method can be used. Among them, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing with hot water are particularly preferable. Hole treatment is preferred. Each will be described below.
<Sealing treatment with an aqueous solution containing an inorganic fluorine compound>
As the inorganic fluorine compound used for the sealing treatment with an aqueous solution containing an inorganic fluorine compound, a metal fluoride is preferably exemplified.
Specifically, for example, sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, sodium fluoride zirconate, potassium fluoride zirconate, sodium fluoride titanate, potassium fluoride titanate, zircon fluoride Ammonium acid, ammonium fluoride titanate, potassium fluoride titanate, zirconate fluoride, titanate fluoride, hexafluorosilicic acid, nickel fluoride, iron fluoride, phosphor fluoride, ammonium fluoride phosphate It is done. Of these, sodium fluorinated zirconate, sodium fluorinated titanate, fluorinated zirconic acid, and fluorinated titanic acid are preferable.

  The concentration of the inorganic fluorine compound in the aqueous solution is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, from the viewpoint of sufficiently sealing the micropores of the anodized film. Further, in terms of stain resistance, it is preferably 1% by mass or less, and more preferably 0.5% by mass or less.

  It is preferable that the aqueous solution containing an inorganic fluorine compound further contains a phosphate compound. When the phosphate compound is contained, the hydrophilicity of the surface of the anodized film is improved, so that the on-press developability and stain resistance can be improved.

Suitable examples of the phosphate compound include phosphates of metals such as alkali metals and alkaline earth metals.
Specifically, for example, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, monoammonium phosphate, monopotassium phosphate, monosodium phosphate, dihydrogen phosphate Potassium, dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium hydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, hydrogen phosphate Disodium, lead phosphate, diammonium phosphate, calcium dihydrogen phosphate, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate, sodium phosphite , Tripolyphosphate Potassium, and sodium pyrophosphate. Among these, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are preferable.
The combination of the inorganic fluorine compound and the phosphate compound is not particularly limited, but the aqueous solution contains at least sodium zirconate fluoride as the inorganic fluorine compound and contains at least sodium dihydrogen phosphate as the phosphate compound. Is preferred.

  The concentration of the phosphate compound in the aqueous solution is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of improving on-press developability and stain resistance. Further, in terms of solubility, it is preferably 20% by mass or less, and more preferably 5% by mass or less.

The ratio of each compound in the aqueous solution is not particularly limited, but the mass ratio of the inorganic fluorine compound and the phosphate compound is preferably 1/200 to 10/1, and preferably 1/30 to 2/1. Is more preferable.
The temperature of the aqueous solution is preferably 20 ° C. or higher, more preferably 40 ° C. or higher, preferably 100 ° C. or lower, more preferably 80 ° C. or lower.
The aqueous solution preferably has a pH of 1 or more, more preferably has a pH of 2 or more, preferably has a pH of 11 or less, and more preferably has a pH of 5 or less.
The method for sealing with an aqueous solution containing an inorganic fluorine compound is not particularly limited, and examples thereof include a dipping method and a spray method. These may be used alone or in combination, or may be used in combination of two or more.
Of these, the dipping method is preferred. When processing using the immersion method, the processing time is preferably 1 second or longer, more preferably 3 seconds or longer, and preferably 100 seconds or shorter, and 20 seconds or shorter. More preferred.

<Sealing treatment with water vapor>
Examples of the sealing treatment with water vapor include a method in which pressurized or normal pressure water vapor is brought into contact with the anodized film continuously or discontinuously.
The temperature of the water vapor is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and preferably 105 ° C. or lower.
The water vapor pressure is preferably in the range (1.008 × 10 ^{5 to} 1.043 × 10 ⁵ Pa) from (atmospheric pressure−50 mmAq) to (atmospheric pressure + 300 mmAq).
Further, the time for which the water vapor is contacted is preferably 1 second or longer, more preferably 3 seconds or longer, 100 seconds or shorter, more preferably 20 seconds or shorter.

<Sealing treatment with hot water>
Examples of the sealing treatment with water vapor include a method in which an aluminum plate on which an anodized film is formed is immersed in hot water.
The hot water may contain an inorganic salt (for example, phosphate) or an organic salt.
The temperature of the hot water is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and preferably 100 ° C. or lower.
In addition, the time for immersion in hot water is preferably 1 second or longer, more preferably 3 seconds or longer, 100 seconds or shorter, more preferably 20 seconds or shorter.

<Hydrophilic treatment>
The hydrophilization treatment is described in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There are such alkali metal silicate methods. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, And a method of treating with polyvinylphosphonic acid as described in each specification of No.272.

  When using a support with insufficient surface hydrophilicity such as a polyester film as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metal described in JP-A-2001-199175 A hydrophilic layer obtained by coating a coating solution containing a colloid of oxide or hydroxide of the above, or organic hydrophilicity obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer described in JP-A-2002-79772 A hydrophilic layer having a hydrophilic matrix, a hydrophilic layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or metal oxide A hydrophilic layer made of an inorganic thin film having a surface is preferred.Among these, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or hydroxide colloid is preferable.

  Moreover, when using a polyester film etc. as a support body of this invention, it is preferable to provide an antistatic layer in the hydrophilic layer side of a support body, the opposite side, or both sides. In the case where the antistatic layer is provided between the support and the hydrophilic layer, it also contributes to improving the adhesion with the hydrophilic layer. As the antistatic layer, a polymer layer in which metal oxide fine particles or a matting agent are dispersed as described in JP-A-2002-79772 can be used.

  The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the photopolymerization layer, good printing durability and good stain resistance can be obtained.

<Back coat layer>
After the surface treatment is performed on the support or after the undercoat layer is formed, a back coat can be provided on the back surface of the support, if necessary.
Examples of the back coat include hydrolysis and polycondensation of organic polymer compounds described in JP-A-5-45885, organometallic compounds or inorganic metal compounds described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this manner is preferred. Among them, Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si
It is preferable to use a silicon alkoxy compound such as (OC ₄ H9) ₄ because the raw material is inexpensive and easily available.

<Undercoat layer>
In the lithographic printing plate precursor according to the invention, an undercoat layer can be provided between the photopolymerizable layer and the support, if necessary. Since the undercoat layer functions as a heat insulating layer, heat generated by exposure with an infrared laser does not diffuse to the support and can be used efficiently, so that there is an advantage that high sensitivity can be achieved. In the unexposed area, the photopolymerizable layer is easily peeled off from the support, so that the on-press developability is improved.
As the undercoat layer, specifically, a silane coupling agent having an ethylenic double bond reactive group capable of addition polymerization described in JP-A-10-282679, an ethylenic double bond reaction Preferable examples include a phosphorus compound having a group.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 3 to 30 mg / m ^2.

<Protective layer>
In the lithographic printing plate precursor according to the present invention, if necessary, a protective layer is provided on the photopolymerization layer in order to prevent generation of scratches in the photopolymerization layer, to block oxygen, and to prevent ablation at the time of high-illuminance laser exposure. Can do.
In the present invention, the exposure is usually carried out in the atmosphere, but the protective layer is a light of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that inhibit the image forming reaction caused by the exposure in the photopolymerization layer. It prevents mixing into the polymerized layer and prevents inhibition of image formation reaction due to exposure in the atmosphere. Therefore, the property desired for the protective layer is that the permeability of low molecular compounds such as oxygen is low,
Furthermore, it is preferable that the light used for the exposure has good transparency, has excellent adhesion to the photopolymerization layer, and can be easily removed in an on-press development process after exposure. Various studies have been made on protective layers having such characteristics, and are described in detail, for example, in US Pat. No. 3,458,311 and JP-A-55-49729.

Examples of the material used for the protective layer include water-soluble polymer compounds that are relatively excellent in crystallinity. Specific examples include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid. Among these, when polyvinyl alcohol (PVA) is used as a main component, the best results are obtained for basic characteristics such as oxygen barrier properties and development removability. The polyvinyl alcohol may be partially substituted with an ester, ether or acetal as long as it contains an unsubstituted vinyl alcohol unit for providing the oxygen barrier property and water solubility necessary for the protective layer, and a part of the other You may have a copolymerization component.
Specific examples of the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a degree of polymerization of 300 to 2400. Specifically, for example, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA- HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA-420, PVA-613, and L-8 are mentioned.

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

As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added.
The thickness of the protective layer is suitably from 0.05 to 4 μm, particularly preferably from 0.1 to 2.5 μm.

  In addition, adhesion to the image area, scratch resistance, and the like are extremely important in handling the lithographic printing plate precursor. That is, when a protective layer that is hydrophilic because it contains a water-soluble polymer compound is laminated on a photopolymerizable layer that is oleophilic, the protective layer easily peels off due to insufficient adhesion, and polymerization is inhibited by oxygen at the peeled portion. It may cause defects such as poor film hardening due to.

On the other hand, various proposals have been made to improve the adhesion between the photopolymerizable layer and the protective layer. For example, JP-A-49-70702 and British Patent Application No. 1303578 disclose an acrylic emulsion, a water-insoluble vinylpyrrolidone-vinyl acetate copolymer, etc. in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and laminating on a photopolymerization layer. Any of these known techniques can be used in the present invention. The method for applying the protective layer is described in detail, for example, in US Pat. No. 3,458,311 and JP-A-55-49729.
Furthermore, other functions can be imparted to the protective layer. For example, by adding a colorant (for example, a water-soluble dye) that is excellent in the transparency of infrared rays used for exposure and that can efficiently absorb light of other wavelengths, safe light is not caused. Suitability can be improved.

[exposure]
As a light source for exposing the lithographic printing plate precursor according to the invention, a known light source can be used without limitation. The desirable wavelength of the light source is 300 nm to 1200 nm. Specifically, it is preferable to use various lasers as the light source, and among these, a semiconductor laser that emits infrared light with a wavelength of 760 nm to 1200 nm is preferably used.
The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like.
In addition, as other exposure light rays for the lithographic printing plate precursor according to the present invention, ultrahigh pressure, high pressure, medium pressure, low pressure mercury lamps, chemical lamps, carbon arc lamps, xenon lamps, metal halide lamps, various visible and ultraviolet laser lamps Fluorescent lamps, tungsten lamps, sunlight, etc. can also be used.

[printing]
The lithographic printing method using the lithographic printing plate precursor according to the present invention is not particularly limited. For example, the lithographic printing plate precursor according to the present invention is imagewise exposed with a laser such as an infrared laser and then undergoes any development processing step. A method of printing by supplying oil-based ink and water-based component without any problem.
Specifically, after a lithographic printing plate precursor is exposed with a laser, it is mounted on a printing machine without passing through a development process, and after printing the lithographic printing plate precursor on a printing machine, a laser is used on the printing machine. And a method of printing without passing through a development processing step.

After the lithographic printing plate precursor is exposed imagewise with a laser, the aqueous component and the oil-based ink are supplied and printed without going through a development process such as a wet development process. The image recording layer cured by the above process forms an oil-based ink receiving portion having an oleophilic surface. On the other hand, in the unexposed area, the uncured image recording layer is dissolved or dispersed and removed by the supplied aqueous component and / or oil-based ink, and a hydrophilic surface is exposed in that area. As a result, the aqueous component adheres to the exposed hydrophilic surface, and the oil-based ink is deposited on the image recording layer in the exposed area, and printing is started. Here, the water-based component or oil-based ink may be first supplied to the plate surface, but the oil-based ink is first used in order to prevent the water-based component from being contaminated by the image recording layer in the unexposed area. It is preferable to supply. As the aqueous component and oil-based ink, dampening water and printing ink for ordinary lithographic printing are used.
In this way, the lithographic printing plate precursor is subjected to on-press development on an offset printing machine and used as it is for printing a large number of sheets.

  Further, after the lithographic printing plate precursor of the present invention is imagewise exposed with a laser, a development treatment may be performed using a non-alkaline aqueous solution having a pH of 10 or less as a developer. As the non-alkaline aqueous solution that can be used here, for example, water alone or an aqueous solution containing water as a main component (containing 60% by mass or more of water) is preferable. The aqueous solution containing an aqueous solution or a surfactant (anionic, nonionic, cationic, etc.) is preferred. The pH of the developer is preferably from 2 to 10, more preferably from 3 to 9, and even more preferably from 5 to 9. .

The non-alkali aqueous solution that can be used as the developer may contain an organic acid, an inorganic acid, an inorganic salt, or the like.
Examples of organic acids include citric acid, acetic acid, succinic acid, malonic acid, salicylic acid, caprylic acid, tartaric acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic acid, xylenesulfonic acid, phytic acid, and organic phosphonic acid. . The organic acid can also be used in the form of its alkali metal salt or ammonium salt. The content in the developer is preferably 0.01 to 5% by mass.

  Examples of inorganic acids and inorganic salts include phosphoric acid, metaphosphoric acid, primary ammonium phosphate, secondary ammonium phosphate, primary sodium phosphate, secondary sodium phosphate, primary potassium phosphate, secondary potassium phosphate, Examples include sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium sulfite, ammonium sulfite, sodium hydrogen sulfate, nickel sulfate and the like. The content in the developer is preferably 0.01 to 5% by mass.

  Examples of the anionic surfactant that can be used in the developer used in the present invention include fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinic acid salts, linear alkylbenzenesulfonic acid salts, Branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium, N-alkyl sulfosuccinic acid monoamides Sodium salts, petroleum sulfonates, sulfated castor oil, sulfated beef tallow oil, fatty acid alkyl ester sulfate esters, alkyl sulfate esters, polyoxyethylene alkyl ether sulfates Ester salt, fatty acid monoglyceride sulfate ester, polyoxyethylene alkylphenyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkylphenyl ether phosphate Examples thereof include ester salts, partially saponified products of styrene-maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, and naphthalene sulfonate formalin condensates. Among these, dialkyl sulfosuccinates, alkyl sulfate esters and alkyl naphthalene sulfonates are particularly preferably used.

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

Nonionic surfactants that can be used in the developer used in the present invention include polyethylene glycol type higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide Adducts, higher alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, fat and oil ethylene oxide adducts, polypropylene glycol ethylene oxide adducts, dimethylsiloxane-ethylene oxide block copolymers, dimethylsiloxane- (propylene oxide-ethylene oxide) Block copolymer, fatty acid ester of polyhydric alcohol glycerol, fatty acid ester of pentaerythritol, Bitoru and fatty acid esters of sorbitan, fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines.
These surfactants may be used alone or in combination of two or more. In the present invention, ethylene oxide adduct of sorbitol and / or sorbitan fatty acid ester, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide-ethylene oxide) block copolymer, polyhydric alcohol Fatty acid esters are more preferred.

Further, from the viewpoint of stable solubility or turbidity in water, the nonionic surfactant used in the developer of the present invention is HLB (Hydrophile-Lipophile).
The (Balance) value is preferably 6 or more, and more preferably 8 or more.
Furthermore, the ratio of the surfactant contained in the developer is preferably 0.01 to 10% by mass, and more preferably 0.01 to 5% by mass.
Acetylene glycol-based and acetylene alcohol-based oxyethylene adducts, fluorine-based and silicon-based surfactants can also be used in the same manner.
As the surfactant used in the developer of the present invention, a nonionic surfactant is particularly suitable from the viewpoint of foam suppression.

The developer used in the present invention may contain an organic solvent. Examples of the organic solvent that can be contained here include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (produced by Esso Chemical Co., Ltd.) or gasoline, kerosene, etc.), aromatic hydrocarbons, and the like. (Toluene, xylene, etc.), halogenated hydrocarbons (methylene dichloride, ethylene dichloride, trichlene, monochlorobenzene, etc.) and the following polar solvents.
Examples of polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, propylene glycol mono Ethyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polypropylene glycol, tetraethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, ethylene glycol monophenyl ether, methylphenyl carbinol, n-amyl alcohol, methyl amyl Alcoa Etc.), ketones (acetone, methyl ethyl ketone, ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), esters (ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, methyl lactate, butyl lactate, ethylene glycol monobutyl) Acetate, propylene glycol monomethyl ether acetate, diethylene glycol acetate, diethyl phthalate, butyl levulinate, etc.) and others (triethyl phosphate, tricresyl phosphate, N-phenylethanolamine, N-phenyldiethanolamine, etc.).

  When the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. When the developer contains an organic solvent, the concentration of the solvent is preferably less than 40% by mass from the viewpoint of safety and flammability.

  In the developer used in the present invention, as a water-soluble polymer compound, soybean polysaccharide, modified starch, gum arabic, dextrin, fiber derivative (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, Pullulan, polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone, polyacrylamide and acrylamide copolymer, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride copolymer, etc. Can be contained.

  A well-known thing can be used for the said soybean polysaccharide, for example, there exists a brand name Soya Five (made by Fuji Oil Co., Ltd.) as a commercial item, and the thing of various grades can be used. What can be preferably used is one in which the viscosity of a 10% by mass aqueous solution is in the range of 10 to 100 mPa / sec.

As the modified starch, known ones can be used, and starch such as corn, potato, tapioca, rice and wheat is decomposed with acid or enzyme in the range of 5 to 30 glucose residues per molecule, and further in an alkali. It can be made by a method of adding oxypropylene or the like.
Two or more water-soluble polymer compounds can be used in combination. The content of the water-soluble polymer compound in the developer is preferably from 0.1 to 20% by mass, and more preferably from 0.5 to 10% by mass.

  In addition to the above, the developer used in the present invention may contain a preservative, a chelate compound, an antifoaming agent and the like.

  Preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzisothiazolin-3-one, benztriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, pyridine, Derivatives such as quinoline and guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives, nitrobromoalcohol-based 2-bromo-2-nitropropane-1,3diol, 1,1-dibromo-1-nitro-2-ethanol, 1,1-dibromo-1-nitro-2-propanol and the like can be preferably used.

  Examples of the chelate compound include ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, potassium salt thereof, sodium salt thereof, hydroxyethylethylenediaminetriacetic acid Nitrilotriacetic acid, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri (methylenephosphonic acid), potassium salt, sodium salt And organic phosphonic acids and phosphonoalkanetricarboxylic acids. Organic amine salts are also effective in place of the sodium and potassium salts of the chelating agents.

  As the antifoaming agent, a general silicon-based self-emulsifying type, emulsifying type, or nonionic surfactant having a HLB of 5 or less can be used. Silicon antifoaming agents are preferred. Among them, emulsification dispersion type and solubilization can be used.

The development processing with a non-alkaline aqueous solution in the present invention can be preferably carried out by an automatic processor equipped with a developer supply means and a rubbing member. As an automatic processor, for example, an automatic processor described in JP-A-2-220061 and JP-A-60-59351, which performs rubbing while conveying a lithographic printing original plate after image recording, Automatic processing machine for rubbing the lithographic printing plate after image recording set on the cylinder described in the specifications of Japanese Patent No. 5148746, US Pat. No. 5,568,768 and British Patent No. 2297719 while rotating the cylinder Etc. Among these, an automatic processor using a rotating brush roll as the rubbing member is particularly preferable. In the present invention, the lithographic printing plate after the rubbing treatment can be optionally washed with water, dried and desensitized.
Although the temperature of the developer can be used at any temperature, it is preferably 10 ° C to 50 ° C.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. Examples 1-6, 1-14, 2-1 , 2-2, 2-4, 2-7 and 2-9 are reference examples.
1. Preparation of lithographic printing plate precursor (1) Preparation of support <Support A>
In order to remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution. The aluminum surface was grained using three bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed thoroughly with water. This plate was etched by being immersed in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds, washed with water, further immersed in 20% nitric acid at 60 ° C. for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave alternating current. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. The amount of electricity in the nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode.
Then, water washing by spraying was performed.

Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. After the plate form a direct current anodized film of 2.5 g / m ² at a current density of 15A / dm ² 15% sulfuric acid (containing 0.5 mass% aluminum ion) as the electrolytic solution, washed with water, dried support A. The centerline average roughness (Ra) of this substrate was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

<Support B>: FZP treated substrate The support provided up to the anodic oxide film in the same manner as the support A described above has a pH of 3.7 containing 0.1% by mass of sodium zirconate fluoride and 1% by mass of sodium dihydrogen phosphate. Was immersed in a solution heated to 75 ° C. for 10 seconds to perform sealing treatment. Thereafter, the support B was obtained by washing with water and drying.

<Support C>: FZP pore wide treatment The support provided up to the anodic oxide film as in the above support A was treated with a 1% by weight aqueous solution of sodium hydroxide at 60 ° C. for 10 seconds to treat the pores of the anodic oxide film. Enlargement processing was performed. By this treatment, the pore diameter of the anodized film was expanded to 20 nm.
After performing the pore-wide treatment, it was immersed in a solution heated to 75 ° C. at pH 3.7 containing 0.1% sodium zirconate fluoride and 1% sodium dihydrogen phosphate for 10 seconds to perform sealing treatment. Thereafter, the support C was obtained by washing with water and drying.
About the said support bodies B and C, it processed for 10 second at 30 degreeC with the 2.5 mass% sodium silicate aqueous solution. When the center line average roughness (Ra) of these substrates was measured using a needle having a diameter of 2 μm, all of them were 0.51 μm.

(2) Formation of undercoat layer The following undercoat liquid (1) was applied to a dry coating amount of 10 mg / m ² to prepare a support used in the following experiments.
Undercoat liquid (1)
・ Undercoat compound (1) 0.017g
・ Methanol 9.00g
・ Water 1.00g

(3) Formation of photopolymerization layer (Example 1-1)
After the photopolymerization layer coating liquid (1) having the following composition is bar-coated on the support B, 100 ° C,
Oven drying was performed for 60 seconds to form a photopolymerization layer having a dry coating amount of 1.0 g / m ² to obtain a lithographic printing plate precursor.

The photopolymerization layer coating solution (1) was obtained by mixing and stirring the following photosensitive solution (1) and microcapsule solution (1) immediately before coating.
Photosensitive solution (1)
・ Specific polymer compound (Exemplary Compound (2)) 0.162g
・ The following polymerization initiator (1) 0.100 g
・ The following infrared absorber (1) 0.020g
・ Polymerizable monomer, Aronix M-215 (manufactured by Toa Gosei Co., Ltd.) 0.385 g
・ 0.044 g of the following fluorosurfactant (1)
・ MEK 1.091g
・ MFG 8.609g
Microcapsule liquid (1)
・ Microcapsule synthesized as follows (1) 2.640g
・ Water 2.425g

[Synthesis of Specific Polymer Compound (Exemplary Compound 2) described in Synthesis Example 1 and Example 1-1]
In a 1000 ml three-necked flask equipped with a condenser and a stirrer, 250 g of 1-methoxy-2-propanol was placed and heated to 75 ° C. Under a nitrogen stream, 124 g of methyl methacrylate, 90 g of Blemmer PME200 (trade name: manufactured by NOF Corporation) and 1.79 g of V-601 (trade name: manufactured by Wako Pure Chemical Industries) were dissolved in 250 g of 1-methoxy-2-propanol. The solution was added dropwise over 2.5 hours.
The mixture was further reacted at 75 ° C. for 2 hours. Next, the reaction solution was poured into water to precipitate a copolymer. This was collected by filtration, washed and dried to obtain Exemplified Compound (2). The weight average molecular weight measured by gel permeation chromatography (GPC) using polystyrene as a standard substance was 120,000. Moreover, it was 35 degreeC as a result of measuring Tg with a differential scanning calorimeter (DSC).
In the same manner as in Synthesis Example 1, the polymer compounds used in the following Examples were synthesized. Tables 1, 2, and 4 show the weight average molecular weight and Tg.

Synthesis of Microcapsule (1) As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemicals, Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd.) SR444) 3.15 g, 0.35 g of the following infrared absorber (2), 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane (ODB manufactured by Yamamoto Kasei), and Pionein A -41C (manufactured by Takemoto Yushi Co., Ltd.) 0.1 g was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 3 hours. The microcapsule solution thus obtained was diluted with distilled water so that the solid content concentration was 15% by mass. The average particle size was 0.2 μm.

(Comparative Example 1-1)
A lithographic printing plate precursor was obtained by forming a photopolymerization layer in the same manner as in Example 1-1 except that the specific polymer compound was changed to polystyrene (weight average molecular weight 100,000, Tg 100 ° C.).

(Examples 1-2 to 1-7)
A lithographic printing plate precursor was obtained by forming a photopolymerization layer in the same manner as in Example 1-1, except that the support and the specific polymer compound were changed as shown in Table 1 below.

(Example 1-8)
A photopolymerization layer coating solution (2) having the following composition was bar-coated on the support A, followed by oven drying at 100 ° C. for 60 seconds to form a photopolymerization layer having a dry coating amount of 1.0 g / m ^2. A lithographic printing plate precursor was obtained.

Photopolymerization layer coating solution (2)
・ The following infrared absorber (2) 0.05g
・ 0.20g of the above polymerization initiator (1)
・ Specific polymer compound (Exemplary Compound (6)) 0.50 g
・ Polymerizable monomer, Aronix M-215 (manufactured by Toa Gosei Co., Ltd.) 1.00g
・ Victoria Pure Blue Naphthalenesulfonate 0.02g
・ 0.10g of the above fluorosurfactant (1)
・ Methyl ethyl ketone 18.0g

(Examples 1-9 to 1-14)
A lithographic printing plate precursor was obtained by forming a photopolymerization layer in the same manner as in Example 1-8, except that the support and the specific polymer compound were changed as shown in Table 2 below.

(Comparative Example 1-2)
A lithographic printing plate precursor was obtained by forming a photopolymerization layer in the same manner as in Example 1-9, except that the specific polymer compound was changed to a polymer having the following structure (weight average molecular weight 200,000, Tg 90 ° C.).

2. Exposure and Printing Each lithographic printing plate precursor obtained in the above examples and comparative examples was exposed with a water-cooled 40 W infrared semiconductor laser-mounted Creo Trendsetter 3244VX under conditions of an output of 9 W, an outer drum rotating speed of 210 rpm, and a resolution of 2400 dpi. . The exposure image includes a thin line chart. The obtained exposed original plate was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg without developing. Dampening water (EU-3 (etch solution manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (Dainippon Ink & Chemicals, Inc.) After supplying dampening water and ink, 100 sheets were printed at a printing speed of 6000 sheets per hour.
When the on-press development of the unexposed portion of the photopolymerization layer was completed on the printing press and the number of printing paper required until the ink was not transferred to the printing paper was measured as on-press developability, Even when the planographic printing plate precursor was used, a printed matter having no stain on the non-image area was obtained within 100 sheets.

3. Evaluation In general, in the case of a negative lithographic printing plate precursor, when the exposure amount is small, the degree of curing of the photopolymerization layer (photosensitive layer) decreases, and when the amount of exposure is large, the degree of curing increases. If the photopolymerization layer has a too low degree of curing, the printing durability of the lithographic printing plate will be low, and the reproducibility of small dots and fine lines will be poor. On the other hand, when the degree of cure of the image recording layer is high, the printing durability is high, and the reproducibility of small dots and fine lines is good.
In the Examples, as shown below, the negative lithographic printing plate precursor obtained above was evaluated for printing durability and fine line reproducibility under the same exposure amount conditions described above, thereby improving the sensitivity of the lithographic printing plate precursor. It was used as an index. That is, it can be said that the sensitivity of the lithographic printing plate precursor is higher as the number of printed sheets in printing durability is higher and the fine line width in fine line reproducibility is narrower.

(1) Fine line reproducibility As described above, after 100 sheets were printed and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were continuously printed. A fine line chart of the 600th printed material (10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 60, 80, 100, and 200 μm wide thin line chart) with a 25X magnifier The fine line reproducibility was evaluated based on the fine line width that was observed and reproduced with ink without interruption.

(2) Printing durability As described above, after printing was performed in the evaluation of fine line reproducibility, printing was further continued. As the number of printed sheets was increased, the photopolymerization layer was gradually worn out and the ink receptivity was lowered, so that the ink density in the printing paper was lowered. Printing durability was evaluated by the number of printed sheets when the ink density (reflection density) was reduced by 0.1 from the start of printing.
The evaluation results are shown in Table 3 together with the on-press developability results.

(Examples 1-15 to 1-17)
A lithographic printing plate precursor was obtained by forming a photopolymerization layer in the same manner as in Example 1-1, except that the support and the specific polymer compound were changed as shown in Table 4 below.

After applying the photopolymerization layer coating liquid (3) having the following composition onto the support described in Table 4, it was 100
Oven-dried at 60 ° C. for 60 seconds to form a photopolymerization layer having a dry coating amount of 1.0 g / m ^2. A protective layer coating liquid (1) having the following composition is formed on this with a dry coating amount of 0.5 g / m. ² and dried at 120 ° C. for 1 minute to obtain a lithographic printing plate precursor.

Photopolymerization layer coating solution (3)
・ The following polymerization initiator (2) 0.2 g
・ The following sensitizing dye (1) 0.5 g
Specific polymer compound (described in Table 4) 6.0 g
・ Polymerizable monomer, isocyanuric acid EO-modified triacrylate 12.4 g
(M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
-Thermal polymerization inhibitor, N-nitrosophenylhydroxylamine aluminum salt 0.1 g
・ Tetraethylammonium chloride 0.1g
・ Fluorine-based surfactant (1) 0.1g
・ Methyl ethyl ketone 70.0g

Protective layer coating solution (1)
Polyvinyl alcohol (saponification degree 95 mol%, polymerization degree 800) 40 g
・ Polyvinylpyrrolidone (molecular weight 50,000) 5g
・ Poly (vinyl pyrrolidone / vinyl acetate (1/1)) molecular weight of 75 g
・ 950g of water

(Comparative Example 1-3)
A lithographic printing plate precursor was obtained by forming a photopolymerizable layer in the same manner as in Example 1-15, except that the specific polymer compound was changed to poly t-butyl methacrylate (weight average molecular weight 120,000, Tg 120 ° C.). .

(Examples 1-18 to 1-20)
Except for changing the photopolymerization layer coating solution (3) to a photopolymerization layer coating solution (4) having the following composition,
A lithographic printing plate precursor was obtained in the same manner as the preparation of the lithographic printing plate precursors 15 to 17.

Photopolymerization layer coating solution (4)
・ The following polymerization initiator (3) 0.2 g
・ Specific polymer compounds (described in Table 4) 3.0 g
・ Polymerizable monomer, isocyanuric acid EO-modified triacrylate 6.2 g
(M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
-Thermal polymerization inhibitor, N-nitrosophenylhydroxylamine aluminum salt 0.1 g
・ Fluorine-based surfactant (1) 0.1g
・ Microcapsule (1) (in terms of solid content) 10.0 g
・ Methyl ethyl ketone 35.0g
・ 35.0 g of 1-methoxy-2-propanol
・ Water 10.0g

(Comparative Example 1-4)
A lithographic printing plate precursor was obtained by forming a photopolymerization layer in the same manner as in Example 1-18, except that the specific polymer compound was changed to poly t-butyl methacrylate (weight average molecular weight 120,000, Tg 120 ° C.). .

Exposure Method The lithographic printing plate precursor was exposed with a 375 nm or 405 nm semiconductor laser under the conditions of an output of 2 mW, an outer drum with a peripheral length of 900 mm, a drum rotation speed of 800 rpm, and a resolution of 2400 dpi. One pixel drawing time is as shown in Table 5.

Printing method The lithographic printing plate precursor is attached to a cylinder of SOR-M manufactured by Heidelberg without developing the exposed exposed original plate, and dampening water (EU-3 (Etch solution manufactured by Fuji Photo Film Co., Ltd.) ) / Water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.), and after supplying dampening water and ink, every hour 100 sheets were printed at a printing speed of 6000 sheets. Removal of the unexposed portion of the photopolymerized layer on the printing machine was completed, and a printed matter free from ink stains in the non-image portion was obtained.

Evaluation of lithographic printing plate precursor The fine line reproducibility, on-press developability, and printing durability were evaluated in the same manner as in Examples 1-1 to 1-14.
<Sensitivity>
After 100 sheets were printed and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were continuously printed. In the total 600th printed matter, the exposure amount with no unevenness in the ink density in the image area was measured as sensitivity.

<Safety of white light>
An unexposed lithographic printing plate precursor was placed under a white fluorescent lamp and placed under conditions where the light amount of 400 lux was obtained on the surface of the lithographic printing plate precursor, and exposure was performed. The lithographic printing plate precursor exposed to the white light is attached to the cylinder of the SOR-M printing machine manufactured by Heidelberg, without going through the development process, and after printing 100 sheets, ink smear occurs. The exposure time was measured under no white fluorescent lamp. The longer this time, the better the white light safety.

  The results are shown in Table 5.

(Examples 1-21 to 1-25)
A photopolymerization layer coating solution (5) having the following composition was bar-coated on the support A, followed by oven drying at 100 ° C. for 60 seconds to form a photopolymerization layer having a dry coating amount of 1.0 g / m ^2. A lithographic printing plate precursor was obtained. Subsequently, the protective layer coating solution (1) is bar-coated on the photopolymerization layer, 120 ° C.,
A lithographic printing plate precursor was obtained by oven drying in 60 seconds to form a protective layer having a dry coating amount of 0.15 g / m ² .
The photopolymerization layer coating solution (5) was obtained in the same manner as the photopolymerization layer coating solution (1) except that the specific polymer compound used was changed to that shown in Table 6 below.

(Comparative Example 1-5)
A lithographic printing plate precursor was obtained by forming a photopolymerizable layer and a protective layer in the same manner as in Example 1-21, except that the specific polymer compound was changed to the polymer used in Comparative Example 1-2.

Evaluation of planographic printing plate precursor The fine line reproducibility, on-press developability and printing durability were evaluated in the same manner as in Examples 1-1 to 1-14. Table 7 shows the evaluation results.

1. Preparation of lithographic printing plate precursor (1) Preparation of support <Support A>
In order to remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution. The aluminum surface was grained using three bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed thoroughly with water. This plate is 45 ° C
Etching was performed by immersing in 25% aqueous sodium hydroxide solution for 9 seconds, washing with water, further immersing in 20% nitric acid at 60 ° C. for 20 seconds, and washing with water. The etching amount of the grained surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. In the AC power supply waveform, the time TP until the current value reaches the peak from zero is 0.
An electrochemical roughening treatment was performed using a trapezoidal rectangular wave alternating current of 8 msec, a duty ratio of 1: 1, and a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. The amount of electricity in the nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode.
Then, water washing by spraying was performed.

Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. After the plate form a direct current anodized film of 2.5 g / m ² at a current density of 15A / dm ² 15% sulfuric acid (containing 0.5 mass% aluminum ion) as the electrolytic solution, washed with water, dried support A.

<Support B>: FZP pore wide treatment As in the case of Support A, the support provided up to the anodized film was treated with a 1% by weight aqueous solution of sodium hydroxide at 60 ° C. for 10 seconds to enlarge the pores of the anodized film. Processed. By this treatment, the pore diameter of the anodized film was expanded to 20 nm. After performing the pore-wide treatment, it was immersed in a solution heated to 75 ° C. at pH 3.7 containing 0.1% sodium zirconate fluoride and 1% sodium dihydrogen phosphate for 10 seconds to perform sealing treatment. Thereafter, the support B was obtained by washing with water and drying.

<Support C>: Vapor-sealed substrate The support provided up to the anodic oxide film in the same manner as the support A was exposed to a saturated steam atmosphere for 10 seconds to perform a sealing treatment. Thereafter, the support C was obtained by washing with water and drying.
About said support body A, B, and C, it processed at 30 degreeC for 10 second with the 2.5 mass% sodium silicate aqueous solution. When the center line average roughness (Ra) of these substrates was measured using a needle having a diameter of 2 μm, all of them were 0.51 μm.

(2) Formation of undercoat layer The following undercoat liquid (1) was applied to a dry coating amount of 10 mg / m ² to prepare a support used in the following experiments.
Undercoat liquid (1)
・ Undercoat compound (1) 0.017g
・ Methanol 9.00g
・ Water 1.00g

(3) Formation of photopolymerization layer (Example 2-1)
After the photopolymerization layer coating liquid (1) having the following composition is bar-coated on the support B, 100 ° C,
Oven drying was performed for 60 seconds to form a photopolymerization layer having a dry coating amount of 1.0 g / m ² to obtain a lithographic printing plate precursor.

The photopolymerization layer coating solution (1) was obtained by mixing and stirring the following photosensitive solution (1) and microcapsule solution (1) immediately before coating.
Photosensitive solution (1)
・ Specific polymer compound (Exemplary Compound (2)) 0.162g
・ Polymerization initiator (1) 0.100g
・ Infrared absorber (1) 0.020g
・ Polymerizable monomer, Aronix M-215 (manufactured by Toa Gosei Co., Ltd.) 0.385 g
・ Fluorosurfactant (1) 0.044g
・ MEK 1.091g
・ MFG 8.609g
Microcapsule liquid (1)
・ Microcapsule synthesized as follows (1) 2.640g
・ Water 2.425g

[Synthesis of Specific Polymer Compound (Exemplary Compound 22) described in Synthesis Example 1 and Example 2-1]
In a 1000 ml three-necked flask equipped with a condenser and a stirrer, 92 g of 1-methoxy-2-propanol was placed and heated to 75 ° C. A solution in which 50 g of benzyl methacrylate, 29.1 g of Plaxel F (Daicel Chemical Industries, Ltd.) and 0.5 g of V-601 (trade name: Wako Pure Chemical Industries, Ltd.) 0.5 g were dissolved in 92 g of 1-methoxy-2-propanol under a nitrogen stream. Was dropped over a period of two and a half hours.
The mixture was further reacted at 75 ° C. for 2 hours. Next, the reaction solution was poured into water to precipitate a copolymer. This was collected by filtration, washed and dried to obtain Exemplified Compound (22). The weight average molecular weight measured by gel permeation chromatography (GPC) using polystyrene as a standard substance was 140,000. Moreover, it was 50 degreeC as a result of measuring Tg with a differential scanning calorimeter (DSC).
In the same manner as in Synthesis Example 1, the polymer compounds used in the following Examples were synthesized. The weight average molecular weight and Tg are shown in Table 8, Table 9, and Table 11.

Synthesis of microcapsule (1) As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd.) SR444) 3.15 g, infrared absorber (2) 0.35 g, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane (ODB manufactured by Yamamoto Kasei), and Pionine A-41C (Takemoto Yushi Co., Ltd.) 0.1 g was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 3 hours. The microcapsule solution thus obtained was diluted with distilled water so that the solid content concentration was 15% by mass. The average particle size was 0.2 μm.

(Comparative Example 2-1)
A lithographic printing plate is prepared by forming a photopolymerization layer in the same manner as in Example 2-1, except that the support is changed to support A and the specific polymer compound is changed to polystyrene (weight average molecular weight 100,000, Tg 100 ° C.). I got the original version.

(Examples 2-2 to 2-3)
A lithographic printing plate precursor was obtained by forming a photopolymerization layer in the same manner as in Example 2-1, except that the support and the specific polymer compound were changed as shown in Table 8 below.

(Example 2-4)
On the support B, a photopolymerization layer coating solution having the following composition was bar-coated, and then oven-dried at 100 ° C. for 60 seconds to form a photopolymerization layer having a dry coating amount of 1.0 g / m ^2. An original plate for printing was obtained.

Photopolymerization layer coating solution (2)
・ Infrared absorber (2) 0.05g
・ Polymerization initiator (1) 0.20g
・ Specific polymer compound (Exemplary Compound (23)) 0.50 g
・ Polymerizable monomer, Aronix M-215 (manufactured by Toa Gosei Co., Ltd.) 1.00g
・ Victoria Pure Blue Naphthalenesulfonate 0.02g
・ Fluorosurfactant (1) 0.10g
・ Methyl ethyl ketone 18.0g

(Examples 2-5 to 2-6)
A lithographic printing plate precursor was obtained by forming a photopolymerizable layer in the same manner as in Example 2-1, except that the support and the specific polymer compound were changed as shown in Table 9 below.

(Comparative Example 2-2)
A photopolymerization layer was formed in the same manner as in Example 2-4 except that the support was changed to the support B and the specific polymer compound was changed to a polymer having the following structure (weight average molecular weight 200,000, Tg 90 ° C.). A lithographic printing plate precursor was obtained.

2. Exposure and Printing Each lithographic printing plate precursor obtained in the above examples and comparative examples was exposed with a water-cooled 40 W infrared semiconductor laser-mounted Creo Trendsetter 3244VX under conditions of an output of 9 W, an outer drum rotating speed of 210 rpm, and a resolution of 2400 dpi. . The exposure image includes a thin line chart. The obtained exposed original plate was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg without developing. Dampening water (EU-3 (etch solution manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (Dainippon Ink & Chemicals, Inc.) After supplying dampening water and ink, 100 sheets were printed at a printing speed of 6000 sheets per hour.
When the on-press development of the unexposed portion of the photopolymerization layer was completed on the printing press and the number of printing paper required until the ink was not transferred to the printing paper was measured as on-press developability, Even when the planographic printing plate precursor was used, a printed matter having no stain on the non-image area was obtained within 100 sheets.

3. Evaluation In general, in the case of a negative lithographic printing plate precursor, when the exposure amount is small, the degree of curing of the photopolymerization layer (photosensitive layer) decreases, and when the amount of exposure is large, the degree of curing increases. If the photopolymerization layer has a too low degree of curing, the printing durability of the lithographic printing plate will be low, and the reproducibility of small dots and fine lines will be poor. On the other hand, when the degree of cure of the image recording layer is high, the printing durability is high, and the reproducibility of small dots and fine lines is good.
In the Examples, as shown below, the negative lithographic printing plate precursor obtained above was evaluated for printing durability and fine line reproducibility under the same exposure amount conditions described above, thereby improving the sensitivity of the lithographic printing plate precursor. It was used as an index. That is, it can be said that the sensitivity of the lithographic printing plate precursor is higher as the number of printed sheets in printing durability is higher and the fine line width in fine line reproducibility is narrower.

(1) Fine line reproducibility As described above, after 100 sheets were printed and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were continuously printed. A fine line chart of the 600th printed material (10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 60, 80, 100, and 200 μm wide thin line chart) with a 25X magnifier The fine line reproducibility was evaluated based on the fine line width that was observed and reproduced with ink without interruption.

(2) Printing durability As described above, after printing was performed in the evaluation of fine line reproducibility, printing was further continued. As the number of printed sheets was increased, the photopolymerization layer was gradually worn out and the ink receptivity was lowered, so that the ink density in the printing paper was lowered. Printing durability was evaluated by the number of printed sheets when the ink density (reflection density) was reduced by 0.1 from the start of printing.
The evaluation results are shown in Table 10 together with the on-press developability results.

(Examples 2-7 to 8)
A lithographic printing plate precursor was obtained by forming a photopolymerizable layer in the same manner as in Example 2-1, except that the support and the specific polymer compound were changed as shown in Table 11 below.

After applying the photopolymerization layer coating liquid (3) having the following composition onto the support described in Table 11, it was oven dried at 100 ° C. for 60 seconds to form a photopolymerization layer having a dry coating amount of 1.0 g / m ^2. Then, a protective layer coating solution (1) having the following composition was applied thereon so that the dry coating amount was 0.5 g / m ² and dried at 120 ° C. for 1 minute to obtain a lithographic printing plate precursor .

Image forming layer coating solution (3)
-Polymerization initiator (2) 0.2g
・ Sensitizing dye (1) 0.5g
Specific polymer compound (described in Table 11) 6.0 g
・ Polymerizable monomer, isocyanuric acid EO-modified triacrylate 12.4 g
(M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
-Thermal polymerization inhibitor, N-nitrosophenylhydroxylamine aluminum salt 0.1 g
・ Tetraethylammonium chloride 0.1g
・ Fluorine-based surfactant (1) 0.1g
・ Methyl ethyl ketone 70.0g

Protective layer coating solution (1)
Polyvinyl alcohol (saponification degree 95 mol%, polymerization degree 800) 40 g
・ Polyvinylpyrrolidone (molecular weight 50,000) 5g
・ Poly (vinyl pyrrolidone / vinyl acetate (1/1)) molecular weight of 75 g
・ 950g of water

(Comparative Example 2-3)
A photopolymerization layer was formed in the same manner as in Example 2-7, except that the support was changed to support A and the specific polymer compound was changed to poly t-butyl methacrylate (weight average molecular weight 120,000, Tg 120 ° C.). A lithographic printing plate precursor was obtained.

(Examples 2-9 to 2-10)
Except for changing the photopolymerization layer coating solution (3) to a photopolymerization layer coating solution (4) having the following composition,
A lithographic printing plate precursor was obtained in the same manner as the preparation of the lithographic printing plate precursors 7-8.

Image forming layer coating solution (4)
-Polymerization initiator (3) 0.2g
Specific polymer compound (described in Table 11) 3.0 g
・ Polymerizable monomer, isocyanuric acid EO-modified triacrylate 6.2 g
(M-315 manufactured by Toa Gosei Co., Ltd.)
・ Royco Crystal Violet 3.0g
-Thermal polymerization inhibitor, N-nitrosophenylhydroxylamine aluminum salt 0.1 g
・ Fluorine-based surfactant (1) 0.1g
・ Microcapsule (1) (in terms of solid content) 10.0 g
・ Methyl ethyl ketone 35.0g
・ 35.0 g of 1-methoxy-2-propanol
・ Water 10.0g

(Comparative Example 2-4)
A photopolymerization layer was formed in the same manner as in Example 2-9 except that the support was changed to support A and the specific polymer compound was changed to poly t-butyl methacrylate (weight average molecular weight 120,000, Tg 120 ° C.). A lithographic printing plate precursor was obtained.

Exposure Method The lithographic printing plate precursor was exposed with a 375 nm or 405 nm semiconductor laser under the conditions of an output of 2 mW, an outer drum with a peripheral length of 900 mm, a drum rotation speed of 800 rpm, and a resolution of 2400 dpi. One pixel drawing time is as shown in Table 12.

Printing method The lithographic printing plate precursors were each mounted on a cylinder of SOR-M manufactured by Heidelberg without developing the exposed exposed master plate, and dampened with water (EU-3 (Etch solution manufactured by Fuji Photo Film Co., Ltd.). ) / Water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.), and after supplying dampening water and ink, every hour 100 sheets were printed at a printing speed of 6000 sheets. Removal of the unexposed portion of the photopolymerized layer on the printing machine was completed, and a printed matter free from ink stains in the non-image portion was obtained.

Evaluation of planographic printing plate precursor The fine line reproducibility, on-press developability and printing durability were evaluated in the same manner as in Examples 2-1 to 2-6.
<Sensitivity>
After 100 sheets were printed and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were continuously printed. In the total 600th printed matter, the exposure amount with no unevenness in the ink density in the image area was measured as sensitivity.

<Safety of white light>
An unexposed lithographic printing plate precursor was placed under a white fluorescent lamp and placed under conditions where the light amount of 400 lux was obtained on the surface of the lithographic printing plate precursor, and exposure was performed. The lithographic printing plate precursor exposed to the white light is attached to the cylinder of the SOR-M printing machine manufactured by Heidelberg, without going through the development process, and after printing 100 sheets, ink smear occurs. The exposure time was measured under no white fluorescent lamp. The longer this time, the better the white light safety.

  The results are shown in Table 12.

Claims (6)

A lithographic printing plate precursor having a laser-sensitive photopolymerization layer on a hydrophilic support and capable of forming an image without alkali development, wherein the side chain is represented by the following formula (3): A lithographic printing plate precursor comprising a polymer compound having a group and a polymer compound containing a (meth) acrylate unit in which at least one of the groups shown in the following group A is bonded to an ester .

In formula (3), c is an integer of 2 to 7, and n represents an integer of 1 to 100.

The lithographic printing plate precursor as claimed in claim 1, wherein the polymer compound contains a group represented by the formula (3). The lithographic printing plate precursor as claimed in claim 1 or 2, wherein the polymer compound has a glass transition temperature Tg of 90 ° C or lower. The lithographic printing plate precursor according to any one of claims 1 to 3 , wherein the photopolymerizable layer contains microcapsules. The lithographic printing plate precursor as claimed in any one of claims 1 to 4 , wherein the photopolymerization layer further contains an infrared absorber, a polymerization initiator, and a polymerizable compound. The lithographic printing plate precursor according to any one of claims 1 to 5 is mounted on a printing press and imagewise laser exposed, or after imagewise exposure with a laser and then mounted on a printing press, the lithographic plate A lithographic printing method in which printing ink and fountain solution are supplied to a printing plate precursor to remove a laser unexposed portion of the photopolymerized layer and print.