JPH09197685A - Direct plotting type lithographic original plate and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide printed matters with clear image and without scumming or tinting at printing even by plotting from an electrophotographic copying machine based on electrostatic transfer image method. SOLUTION: In a direct plotting type lithographic original plate having an image receiving layer on a water-resistant support, the image receiving layer is characterised by having a water soluble compound [P] containing at least one or more of polar group as shown in the general formula, zinc oxide and binding resin. This image receiving layer is formed by applying coating of dispersion material composed of at least zinc oxide, binding resin, the aforesaid compound [P] and dispersion medium on the water-resistant support.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a direct drawing type lithographic printing plate precursor, and more particularly to a direct drawing type lithographic printing plate precursor suitable for light printing, and a method for producing the same.

[0002]

2. Description of the Related Art At present, a direct drawing type lithographic printing original plate having an image receiving layer on a support is widely used as an office printing original plate. In order to form a plate on such a printing original plate, that is, to form an image, a method of drawing an oil-based ink by hand on the image receiving layer, or a method of printing by a typewriter, an inkjet method, or a transfer type heat-sensitive method is generally used. . In addition, a method of transferring and fixing a toner surface image formed on a photoconductor through a charging, exposing and developing process using a plain paper electrophotographic copying machine (PPC) to an image receiving layer has recently begun to be used. In any case, the printing original plate after plate making is subjected to surface treatment with a desensitizing solution (so-called etchant) to desensitize the non-image area, and then used as a printing plate for lithographic printing.

In a conventional direct drawing type lithographic printing plate precursor, a surface layer was provided on both sides of a support such as paper with a back layer and an intermediate layer interposed. The back surface layer or the intermediate layer is composed of a water-soluble resin such as PVA and starch, a water-dispersible resin such as a synthetic resin emulsion, and a pigment. The surface layer is composed of a pigment, a water-soluble resin and a waterproofing agent. Typical examples of such a lithographic printing plate precursor for direct drawing include a water-soluble resin binder such as PVA, silica, calcium carbonate, etc. for an image receiving layer as described in US Pat. No. 2,532,865. And a water resistant agent such as melamine-formaldehyde resin initial condensate.

Further, as a binder used in the image receiving layer of a direct-drawing type lithographic printing plate precursor, it has a functional group capable of generating a carboxyl group, a hydroxyl group, a thiol group, an amino group, a sulfone group or a phosphono group when decomposed. A resin which contains a functional group that is cured by heat / light and is pre-crosslinked is used (Japanese Patent Laid-Open Nos. 1-226395 and 1-269593).
No. 1-288488), and the above-mentioned functional group-containing resin is used in combination with a thermosetting / photocurable resin (JP-A-1-2665).
No. 46, No. 1-275191, No. 1-309068), and the above-mentioned functional group-containing resin and a cross-linking agent are used in combination (JP-A 1-267093, 1-271292, 1).
No. 309067), improvement of hydrophilicity of non-image area, improvement of film strength of image receiving layer, and further improvement of printing resistance have been investigated.

Further, in the image receiving layer, resin particles having a fine particle diameter of 1 μm or less containing a hydrophilic group such as a carboxyl group, a sulfo group and a phosphono group are contained together with an inorganic pigment and a binder. Kaihei 4-201387, 4-2
No. 23196), or fine resin particles containing a functional group that produces a hydrophilic group as described above by decomposition (Japanese Patent Laid-Open Nos. 4-319491 and 4-353).
No. 495, No. 5-119545, No. 5-58071
JP-A-5-69684) to improve the hydrophilicity of the non-image area.

On the other hand, zinc oxide is used in a direct-drawing type lithographic printing plate precursor in which zinc oxide is used as an inorganic pigment in the image-receiving layer and a non-image area is desensitized to form a printing plate after forming an image. As the above, zinc oxide produced by a wet method is used, and it is used in combination with zinc oxide produced by a dry method (JP-A-5-246166 and JP-A-5-254267).
Alternatively, by using zinc oxide containing a small amount of ferrocyan group (Japanese Patent Laid-Open No. 6-72058), a toner image can be sufficiently transferred to a printing original plate and printing stains can be obtained, especially when used in electrostatic transfer type plate making. It is being studied to suppress this.

[0007]

However, in the conventional printing plate thus obtained, in order to improve printing durability, the water-proofing agent is added in a large amount or a hydrophobic resin is used. When the hydrophobicity is increased, the printing durability is improved, but the hydrophilicity is lowered to cause printing stains. On the other hand, when the hydrophilicity is improved, the water resistance is deteriorated and the printing durability is deteriorated. Particularly, under a use environment at a high temperature of 30 ° C. or higher, the surface layer was dissolved in the immersion water used for offset printing, and there were drawbacks such as deterioration of printing durability and occurrence of printing stains. Further, in the case of direct drawing type lithographic printing, an oil-based ink or the like is drawn on the image-receiving layer as an image area.If the adhesion between the receiving layer of the printing original plate and the oil-based ink is not good, even if the non-image area is hydrophilic However, even if the above-mentioned printing stains do not occur, the problem that the oil-based ink in the image area is lost during printing, and as a result the printing durability is reduced, is still sufficiently solved. Not in.

Further, in recent high-resolution copy image formation by electrophotography using fine dry toner, for example, drawing by electrostatic transfer to an image receiving layer by a laser printer or the like, especially non-image after transfer is performed. It is desired that both the prevention of the background stain of the image portion and the image reproducibility of the image portion be compatible with each other so that the obtained printed matter has a clear image without the background stain.

The present invention improves the above-mentioned problems of the conventional direct-drawing type lithographic printing plate precursor. An object of the present invention is to provide a direct-drawing type lithographic printing plate precursor excellent in desensitizing property which does not generate spot stains as well as uniform background stains as an offset precursor and a method for producing the same. Another object of the present invention is to provide a direct-drawing lithographic printing plate precursor and a method for producing the same, which are capable of obtaining a printed matter having a clear image without printing stain even by drawing from an electrophotographic copying machine by an electrostatic transfer system. Is to provide.

[0010]

The above object is to provide a direct-drawing type lithographic printing plate precursor having an image-receiving layer on a water-resistant support, wherein the image-receiving layer contains at least a polar group of the following general formula (I). It has been found that this can be achieved in a direct-drawing type lithographic printing plate precursor comprising one or more water-soluble compounds (compound [P]), zinc oxide and a binder resin.

[0011]

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The present invention also provides a dispersion comprising at least zinc oxide, a binder resin, the compound [P] and a dispersion medium,
There is provided a method for producing the above-mentioned lithographic printing plate precursor for direct drawing, which is characterized in that an image receiving layer is formed by coating on a water resistant support. The image-receiving layer of the present invention contains the above-mentioned specific substituent-containing water-soluble compound [P] in combination with zinc oxide. As a result, especially in image formation from an electrophotographic copying machine using a dry toner or a thermal transfer copying machine, a plate-making product having no missing image and no stain on the non-image area can be obtained, and a desensitizing treatment can be performed. It is also possible to obtain a clear image without background stains on a printed matter that is offset printed after being used as a printing plate. The surface of the image receiving layer of the present invention preferably has a Bekk smoothness of 30 to 150 (sec / sec).
10 cc), more preferably 40 to 120 (seconds / 10 cc). As a result, the scattering of toner in the non-image area or the stain due to ink adhesion does not pose a practical problem, and the adhesion of toner or ink in the image area is made uniform and sufficient, and the reproducibility of fine lines / fine characters and the uniformity of solid areas are reduced. Will be good.

On the other hand, in the conventional image-receiving layer containing no compound [P], the non-image area is stained even in the above-mentioned Beck smoothness range. When observing the non-image areas of both plates with an optical microscope with a magnification of 200, the number of adhered toner particles per unit area is almost the same, but there is a large difference in the size of the adhered toner particles, which is 15 μm or more. The number of large toner particles of the present invention is remarkably reduced by about 50% or less as compared with the conventional one. As a result, the background stain is suppressed to a level that does not pose a practical problem. Furthermore, when a printing plate that has been subjected to a desensitizing treatment, which is the final purpose, is prepared and printed, the printing plate comprising the present invention has an image portion excellent in reproducibility of fine lines and fine characters and uniformity of solid portions. It is possible to provide an excellent printed matter that has little background stain due to ink adhesion and poses no problem in practical use.

The main reason for producing such excellent effects of the present invention is the effect of the shape of the image receiving layer surface of the present invention. That is, when a three-dimensional surface roughness measured by a stylus surface roughness meter and a surface photograph by SEM were examined,
Compared with the conventional image-receiving layer (which does not contain the compound [P]), the image-receiving layer of the present invention has a surface state in which unevenness is high and the intervals are close. Specifically, ISO-
The surface center average roughness SRa defined by 468 is 1.3.
The average wavelength Sλa for displaying the density of the surface roughness is in the range of up to 3.5 μm and 50 μm or less. More preferably, SRa is 1.35 to 2.5 μm and Sλa is 45 μm.
m or less. It is presumed that this suppresses the adhesion of the scattered toner to the non-image area after electrophotographic plate making and the thickening of the adhered toner during fixing.

The effects of the present invention as described above are more remarkably exhibited when the zinc oxide and the water-soluble compound [P] contained in the image receiving layer of the present invention are wet-dispersed together with the dispersion medium. It is a thing.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The image-receiving layer used in the present invention will be described below. The zinc oxide used in the present invention is, for example, “New Edition Pigment Handbook” 319 edited by Japan Pigment Technology Association.
Page, Seibundou Co., Ltd. (published in 1968), any of those marketed as zinc oxide, zinc white, wet zinc white or activated zinc white may be used. That is, zinc oxide is classified into French method (indirect method), American method (direct method) and wet method as a dry method depending on the starting material and the manufacturing method. For example, Shodo Kagaku Co., Ltd., Sakai Chemical ( Examples thereof include those commercially available from companies such as S.H., Hakusui Chemical Co., Ltd., Honjo Chemical Co., Ltd., Toho Zinc Co., Ltd., and Mitsui Kinzoku Kogyo Co., Ltd.

Among these zinc oxides, those obtained by the dry method have an average primary particle diameter of 1.0 μm or less, and those obtained by the wet method have an average primary particle diameter. Is generally 0.1 μm or less. Next, the water-soluble compound [P] containing at least one polar group represented by the general formula (I) that forms a chelate compound with zinc ions will be described. The compound [P] has at least a solubility in water of 0.5% by weight or more, more preferably 1% by weight or more, and the compound [P] may be any one as long as it satisfies the above physical properties. Good. As the compound [P], preferably, the following general formula (II) contains 1 to 3 polar groups represented by the general formula (I) in the molecule.
To (VI).

[0018]

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In the formulas (II) to (VI), R ₁ , R ₂ and
X, Y and Z each represent an organic residue which may have various substituents and may be bonded to each other to form a ring.
W is a hetero atom such as N atom, methine carbon (-CH <)
Alternatively, it represents a cyclic organic residue. R ₁ and R _{2 each} preferably represent an optionally substituted alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, an alkenyl group or an aralkyl group, and as a substituent, an alkoxy group (-OR ₃ ) or a sulfide group (- SR ₃ ), amino group

[0020]

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Examples thereof include halogen groups, cyano groups, nitro groups, hydroxyl groups, carboxyl groups, sulfonic acid groups, sulfonamide groups, amide groups and ester groups. X, Y, Z
Is preferably a alkylene, cycloalkylene, alkenylene, aralkylene, polyether, polyamine or the like having 1 to 18 carbon atoms which may be substituted, and as a substituent, an alkoxy group (-OR ₃ ) or a sulfide group (-
SR ₃ ), amino group

[0022]

[Chemical 6]

Examples thereof include halogen groups, cyano groups, nitro groups, hydroxyl groups, carboxyl groups, sulfonic acid groups, sulfonamide groups, amide groups and ester groups. R ₃ is an aliphatic group having 1 to 18 carbon atoms and is similar to R ₁ , R ₄ and R ₅ are hydrogen,
It represents an aliphatic group having 1 to 18 carbon atoms which is similar to R ₁ and an aliphatic ring which can be linked together. W is preferably an N atom, a methine carbon (-CH <), a cycloalkyl group, an aralkyl group,
Represents an aryl group.

More preferably, R ₁ and R ₂ are hydrogen and an optionally substituted alkyl group having 1 to 14 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, heptyl, hexyl, octyl, decyl, Dodecyl, hexadecyl, octadecyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-hydroxybutyl, 2
-Methoxyethyl, 2-butoxyethyl, 2-ethoxyethyl, 4-methoxybutyl, methylthioethyl, methylthiobutyl, 2-aminoethyl, N, N'-dimethylaminoethyl, piperidinomethyl, pyrrolidinoethyl,
2-chloroethyl, 2-chlorobutyl, 2-bromoethyl, 2-cyanoethyl, 4-cyanobutyl, 2-carboxyethyl, carboxymethyl, 3-carboxypropyl, 3-morpholinopropyl, 2-morpholinoethyl,
2-sulfoethyl, 2-piperidinoethyl, amidomethyl, thioethyl, imidazolidideethyl, sulfonamideethyl etc.),

An optionally substituted alkenyl group (eg 2
-Methyl-1-propenyl, 2-butenyl, 2-pentenyl, 3-methyl-2-pentenyl, 1-pentenyl,
1-hexenyl, 2-hexenyl, 4-methyl-2-hexenyl, vinyl, 2-propenyl, 3-butenyl, etc.), an optionally substituted aralkyl group (eg benzyl, phenethyl, 3-phenylpropyl, naphthylmethyl, 2 -Naphthylethyl, chlorobenzyl, bromobenzyl, methylbenzyl, ethylbenzyl, methoxybenzyl, dimethylbenzyl, dimethoxybenzyl, cyanobenzyl, nitrobenzyl, hydroxybenzyl, carboxybenzyl, dimethylaminobenzyl, naphthyl,
Adamantyl, amidobenzyl, sulfonamidobenzyl, etc.), an optionally substituted cycloalkyl group (eg, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, 4-methylcyclohexyl, 4-chlorocyclohexyl, 4-methoxycyclohexyl, 4- Cyanocyclohexyl and the like).

More preferably, X, Y and Z have 1 carbon atoms.
To 14 optionally substituted alkylene linking groups (eg,
Methylene, ethylene, propylene, butylene, 1-methylethylene, 1-methylpropylene, 2-methylbutylene, hexylene, 1-hydroxybutylene, 2-hydroxybutylene, 2-hydroxypropylene, 1-carboxybutylene, 2-carboxybutylene, etc. ), An alkenylene linking group which may be substituted (for example, 2-methyl-1
-Propenylene, 2-butenylene, 2-pentenylene,
2-hexenylene etc.), an alkenylene linking group which may be substituted (eg p-xylylene, m-xylylene, o
-Xylylene, 2,5-dimethylxylylene, 2,3
5,6-tetramethylxylylene, 2,5-di (dimethylamino) xylylene, 2,5-dimorpholinoxylylene, 2-methylxylylene, 2-ethylxylylene, naphthylene, adamantylene, 2,5- Dimethoxyxylylene, piperazino dipropylene, 2-butylxylylene, 2,5-dibutylxylylene, etc.),

An optionally substituted cycloalkylene linking group (eg, 1,4-cyclohexylene, 1,3-cyclorobutylene, cyclopropylene, 1,3-cyclopentanylene, 1,2-cyclohexylene, 1, 3-bis (methylene) cyclohexane, 1,4-bis (methylene) cyclohexane, 1,3-bis (methylene) cyclopentane, 1,2-cyclolohexylene, etc., polyethers (eg, diethylene oxide, dipropylene) Oxide, dibutylene oxide, tetraethylene oxide, etc.) and polyamines (eg, diethyleneimine, tetraethyleneimine, etc.).

The polar group-containing compound [P] represented by the general formula (I) may be itself or a salt, and the salt may be an inorganic salt (for example, a salt of lithium, sodium, potassium or the like), ammonium. Salts or salts with organic bases [eg primary amine, secondary amine or tertiary amine (as the hydrocarbon group, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group,
Heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, cyclohexyl group, cyclooctyl group, benzyl group, phenethyl group, etc. Atoms, cyano groups, alkoxy groups, amide groups and the like may be contained), anilines (eg, aniline, N-methylaniline, N, N-dimethylaniline, N-ethylaniline, N-butylaniline) , N-methyl-N-butylaniline, etc.), or a heteroatom-containing cyclic nitrogen compound (eg, pyridine, morpholine, piperazine, pyridine, etc.)].

In these salt compounds, some or all of the acidic groups in the molecule may be salts, and the salts formed may be the same or different. General formulas (II) to (VI) of the present invention
Specific examples of the compound represented by are described below. However, the scope of the present invention is not limited to these. In addition, in specific examples,

[0030]

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Represents

[0032]

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[0033]

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[0034]

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The compounds of the present invention are SYNTHESIS 81-96 (197
9), can be synthesized by addition reaction of phosphonic acid to Schiff base described in "Experimental Chemistry Course 19" (published by Maruzen 1957), dehydration condensation reaction of alcohol and orthophosphoric acid, condensation reaction of alcohol and phosphorus oxychloride, etc. . The content of the compound [P] contained in the image receiving layer of the present invention is 1.0 × 10 ⁻⁴ to 1.0 per 100 g of zinc oxide.
It is preferably x10 ^-1 mol, particularly 1.0 x 10 ^{-4 to} 5.0 x 10 ^-2 mol. This range is suitable for obtaining a printed matter composed of the image portion of a clear copy image and the non-image portion free of background stain. More preferably 2.0 × 10 ⁻⁴ to 4.
It is 0 × 10 ^-2 mol.

On the other hand, by using the water-soluble basic compound (B) together with the compound [P] of the present invention, zinc ion and -PO ₃ H ₂ or -OPO ₃ H _{2 in the} compound [P] are used.
It is also possible to more effectively carry out the effect of the present invention of forming a chelate with and adjusting the aggregation of the chelate. The water-soluble basic compound (B) used together with the compound [P] of the present invention refers to a primary to tertiary amino group, imino group, quaternary ammonium salt group, hydrazine group, nitrogen atom-containing heterocycle in the molecule. At least one basic group selected from the group
It is a compound containing a seed, and its solubility in water may be 0.5% by weight or more, preferably 1% by weight or more. The basic compound (B) is a low molecular weight compound or a molecular weight of about 5
It may be either an oligomer or a polymer in the range of 0 to 1 × 10 ⁶ (these are simply referred to as the polymer).
Preferably, the basic compound (B) is water-soluble.

Specific examples of the low molecular weight compound include Japanese Patent Laid-Open No.
4-11720, 53-109701, JP-A-1
-Lower amines (for example, diethylamine, dipropylamine, dibutylamine, triethylamine, tripropylamine, etc.) and alkanolamines (for example, monoethanolamine, diethanolamine, triethanolamine, monoethanolmethyl) described in JP-A-25994. Amines), polyamines (eg ethylenediamine, N, N'-dimethylethylenediamine, N,
N'-diethylethylenediamine, N, N-dimethylethylenediamine, etc.), JP-A-5-82084 and 5-
No. 104878, No. 5-124372, No. 5-104
As the primary to tertiary amine compounds and quaternary ammonium salt compounds containing a specific substituent described in JP-A No. 879, JP-A No. 5-155171 and the like, which contain a specific substituent,
For example, tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt, tetrabutylammonium salt, trimethylbenzylammonium salt, tributylbenzylammonium salt and the like,
As the counter anion, a halogen ion (for example, fluorine, chlorine, bromine, iodine), a hydroxide ion, a sulfonate ion,
Examples thereof include PF ₆ ⁻ and ClO ₄ ⁻ .

Further, as the polymer having a molecular weight of 500 to 1 × 10 ⁶ , for example, a cationic polymer, concretely, melamine-formaldehyde resin, acetoguanamine-formaldehyde resin, benzoguanamine-formaldehyde resin, polyethyleneimine, polyethyleneiminealkyl are used. Modified product, addition product of polyethylenediimine and mono- or diepoxy compound, addition product of polyethyleneimine and mono- or diacrylate compound, polyamide polyamine, epichlorohydrin, aniline resin hydrochloride, polythiourea hydrochloride, cationized amino resin, polyvinylpyridine hydrochloride Modified salt, polyacrylamide cation modified product (Vinylamine polymer obtained by Hofmann decomposition of polyacrylamide, polyacrylamide was subjected to Mannich reaction with formalin and secondary amine Or a quaternary ammonium salt with dimethylsulfate), polyvinyl benzyl chloride with a quaternary ammonium salt with a tertiary amine, poly (N-vinyl-2-methylimidazolium methylsulfate), above. A (meth) acrylate polymer or copolymer containing a primary to tertiary amino group, a nitrogen atom-containing heterocyclic group or a quaternary ammonium salt group of these basic groups, and a (meth) acrylate copolymer Styrene-based copolymer containing the same basic group or quaternary ammonium salt group as that of the polymer, polyallylamine or alkyl modified products thereof, JP-B-45-2460
1 part or all of the amino group of the polymer containing an aliphatic amino group in the repeating unit described in JP-A-9-
Examples include polyalkylimine compounds converted to salt form or quaternized form, amine adducts of epoxy resins, amine adducts of maleated polymers, amino group-containing polyamide resins, polyamide-epoxy resins, polyamide-epichlorohydrin resins and the like. To be

When the polymer is a copolymer, it may be a random copolymer, a block copolymer such as a graft type / AB type, a star type copolymer or a copolymer having an internal crosslinked structure. Good. The specific compounds of the present invention are not limited to these, and these compounds may be used alone or in combination of two or more. The amount of these basic compounds contained in the image receiving layer is preferably 0.05 to 10 parts by weight per 100 parts by weight of zinc oxide. More preferably, it is 0.1 to 5 parts by weight. The image receiving layer of the present invention is in a dense distribution state with the specific unevenness described above and the surface wettability is adjusted, and as a result,
This range is suitable for obtaining a printed matter having a clear copy image and free of background stains.

Zinc oxide and the water-soluble compound [P] contained in the image receiving layer in the present invention are preferably wet-dispersed together with a dispersion medium. It is considered that such a wet dispersion treatment improves the surface of zinc oxide as follows.

In the wet dispersion process of zinc oxide and compound [P], the surface of zinc oxide fine particles produces zinc ions by the interfacial reaction with protons, which rapidly reacts with compound [P]. Yields a chelate compound,
Since this chelate compound is insoluble in the dispersion medium, it is rapidly precipitated and fixed on the surface of the zinc oxide particles, and the surface of the zinc oxide particles is chemically modified to a hydrophilic atmosphere. Further, the chemically modified zinc oxide particles are in a dispersed state in which the particles form a substantially homogeneous aggregate in the dispersion medium, and when formed as an image receiving layer, have an appropriate unevenness and a dense distribution. It is considered that the membrane state of

In the present invention, a mixture containing at least zinc oxide and a compound [P] having a chelating ability is previously dispersed in a dispersion medium using a wet disperser, and then the dispersion is collected by centrifugation or the like and washed thoroughly with water. After that, the desired chemically modified zinc oxide can be obtained by drying. At this time, in order to improve or adjust the dispersibility of zinc oxide, it is preferable to use a conventionally known dispersant in combination. Alternatively, without drying the solid collected as described above, or as described above, the dispersion subjected to the wet dispersion treatment is not separated and isolated, and the binder resin of the image receiving layer is further separated. It is also possible to add an additive and re-disperse it to prepare a coating dispersion for the image-receiving layer and coat it on a support.

More preferably, in the preparation of the original plate of the present invention, a method of dispersing zinc oxide, a binder resin, compound [P] and other additives together with a dispersion medium and then coating the dispersion directly on the support is mentioned. . This simplifies the manufacturing process and significantly improves the productivity. The dispersion medium in the present invention may be any solvent as long as it has a boiling point of 200 ° C. or lower, preferably 150 ° or lower, and may be used alone or in combination of two or more kinds. As the solvent, water, a water-soluble solvent,
Although not limited to any non-water-soluble solvent, when a non-water-soluble solvent is used as a main dispersion medium, it is dissolved in water or a mixed solvent of water and a water-soluble solvent to dissolve the compound [P]. It is preferable to treat with an emulsion system having a heterogeneous phase. When water is used as the main dispersion medium, the compound [P] used in the present invention has a solubility of 15% by weight or less in water when the chelate compound with zinc ion is formed. Is preferable, and more preferably, 10% by weight or less is used.

As the binder resin used for the image receiving layer of the present invention, all known binder resins can be used. Typical examples are vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-
Methacrylate copolymer, methacrylate copolymer, acrylate copolymer, vinyl acetate copolymer, polyvinyl butyral, alkyd resin, silicone resin, epoxy resin, epoxy ester resin, polyester resin, etc., and polyvinyl alcohol as a water-soluble polymer compound. , Modified polyvinyl alcohol, starch, oxidized starch, carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, polyacrylate, polyvinyl pyrrolidone, polyvinyl ether-maleic anhydride copolymer,
Examples thereof include polyamide and polyacrylamide. These resins may be used alone or in combination of two or more.

The molecular weight of the binder resin used in the image receiving layer of the present invention is preferably 10 ³ to 10 ⁶ , and more preferably 5.
× 10 ^{3 to} 5 × 10 ⁵ . The glass transition point of this resin is preferably -10 ° C to 120 ° C, more preferably 0 ° C to 90 ° C. The image receiving layer of the present invention may contain other components in addition to the above-mentioned components.

In addition to the surface-modified zinc oxide used in the present invention as other components that may be contained, examples of the inorganic pigment include kaolin clay, calcium carbonate, barium carbonate, calcium sulfate, barium sulfate, and the like. Examples thereof include magnesium carbonate, titanium oxide, silica, alumina and the like.
When zinc oxide is used in combination among these inorganic pigments, 100 parts by weight of the surface-modified zinc oxide of the present invention is used.
It can be preferably used in a proportion of 10 to 90 parts by weight. More preferably, it is 20 to 80 parts by weight. Alternatively, when another inorganic pigment is used in combination, it can be used within a range not exceeding 20 parts by weight with respect to the surface-modified zinc oxide of the present invention. Furthermore, in order to improve the desensitization of the image receiving layer,
JP-A-4-2013387, 4-223196, 4-319491, 5-58071, 4-35.
Resin particles containing a specific functional group described in JP-A-3495, JP-A-5-119545, etc. may be contained. By using these other inorganic pigments or resin particles within the above-mentioned range of use, desensitization of the non-image area (hydrophilicity) by the desensitization treatment is sufficiently performed, and the background stain of the printed matter is suppressed. The image portion is sufficiently adhered to the image receiving layer, and sufficient printing durability can be obtained without causing image defects even when the number of printed sheets increases.

The ratio of pigment / binder resin in the image receiving layer is
Generally, the binder resin is 10 to 2 with respect to 100 parts by weight of the pigment.
The proportion is 5 parts by weight, preferably 13 to 22 parts by weight. Within this range, the effects of the present invention are effectively exhibited, and at the same time, film strength is maintained during printing or high hydrophilicity is maintained during desensitization treatment. In addition, a crosslinking agent may be added to the image receiving layer in order to further improve the film strength. In particular, when a water-soluble resin is used as the binder resin, a crosslinking agent is used together to cure the film,
It is preferable to improve water resistance.

Examples of the cross-linking agent include compounds that are commonly used as cross-linking agents. Specifically, "Crosslinking Agent Handbook" edited by Fuzo Yamashita and Tosuke Kaneko, published by Taiseisha (19
81), edited by The Society of Polymer Science, "Polymer Data Handbook,
The basic compounds described in "Baifukan (1986)" and the like can be used.

For example, ammonium chloride, metal ions,
Organic peroxides, organic silane compounds (for example, silanes such as vinyltrimethoxysilane, vinyltributoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane) Coupling agents, etc.), polyisocyanate compounds (for example, toluylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate, hexamethylene diisocyanate, isophorone diisocyanate, high Molecular polyisocyanate, etc.), polyol compound (for example, 1,4-butanediol, polyoxypropylene glycol, polyoxyethylene glycol, 1,1,1-trimethylolpropane, etc.), Amine compound (e.g., ethylenediamine, .gamma.-hydroxypropyl ethylenediamine, phenylenediamine, hexamethylenediamine-diamine, N
-Aminoethylpiperazine, modified aliphatic polyamines, etc.), titanate coupling compounds (e.g. tetrabutoxy titanate, tetrachloroepoxy titanate, isopropyl tristearoyl titanate etc.), aluminum coupling compounds (e.g. aluminum butyrate, aluminum acetyl acetate). , Aluminum oxide octate (aluminum tris (acetylacetate), etc.), polyepoxy group-containing compounds and epoxy resins (for example, "New epoxy resin" edited by Hiroshi Kakiuchi)
"Epoxy Resins" edited by Shokoido (1985), Kuniyuki Hashimoto, compounds listed in Nikkan Kogyo Shimbun (1969), melamine resins (for example, "Yuria Melamine Resin", edited by Ichiro Miwa and Hideo Matsunaga) Kogyo Shimbun (196
9)), poly (meth) acrylate compounds (eg, Shin Okawara, Takeo Saegusa, Toshinobu Higashi, "Oligomer" Kodansha (Published in 1976), Eizo Omori, "Functional acrylic resin""Techno System (1985
Compounds) described in the annual publication) and the like.

In the present invention, a reaction accelerator may be added, if necessary, in order to accelerate the crosslinking reaction in the image receiving layer. When the cross-linking reaction is a reaction mode of forming a chemical bond between functional groups, for example, organic acids (acetic acid, propionic acid, butyric acid, benzenesulfonic acid, p-toluenesulfonic acid), phenols (phenol, chlorophenol, nitro). Phenol, cyanophenol, bromophenol, naphthol, dichlorophenols), organometallic compounds (acetylacetonate zirconium salt, acetylacetone zirconium salt, acetylacetocobalt salt, dibutoxytin dilaurate, etc.), dithiocarbamic acid compounds (diethyldithiocarbamate salts), Tinoulam disulfide compounds (tetramethyltinouram disulfide etc.), carboxylic acid anhydrides (phthalic anhydride, maleic anhydride, succinic anhydride, butylsuccinic anhydride,
3,3 ', 4,4'-tetracarboxylic acid benzophenone dianhydride, trimellitic anhydride, etc.).
When the crosslinking reaction is a polymerizable reaction mode, a polymerization initiator (peroxide, azobis compound, etc.) may be used.

The binder resin is preferably cured by light and / or heat after applying the image receiving layer composition. In order to carry out thermosetting, for example, the drying conditions are made stricter than the drying conditions at the time of the conventional receiving layer production. For example, it is preferable to set the drying conditions to a high temperature and / or a long time, or to further heat-treat after drying the coating solvent. For example, 60 ℃
Process at -150 ° C for 5-120 minutes. When the above-mentioned reaction accelerator is used in combination, the treatment can be performed under milder conditions.

As a method of curing the specific functional group in the resin by irradiation with light, a step of irradiating with light of chemically active light may be included. The chemical actinic rays may be any of visible rays, ultraviolet rays, far ultraviolet rays, electron rays, X rays, γ rays, α rays, etc., but preferably ultraviolet rays, more preferably light rays in the wavelength range of 310 nm to 500 nm. . Generally, low-pressure, high-pressure or ultra-high-pressure mercury lamps and halogen lamps are used. Light irradiation is usually 5 cm to 5
Irradiation from a distance of 0 cm for 10 seconds to 10 minutes is sufficient.

The image receiving layer of the present invention is provided on a water resistant support. As the water-resistant support, water-resistant paper, plastic film, paper laminated with metal foil, plastic film, or the like can be used. In the present invention, an under layer is provided between the support and the image receiving layer for the purpose of improving water resistance and interlayer adhesion, and a back coat layer (back surface layer) is provided on the side of the support opposite to the image receiving layer for curling prevention. ) Can be provided. Here, the under layer is an emulsion resin such as an acrylic resin, ethylene-butadiene copolymer, methacrylic acid ester-butadiene copolymer, acrylonitrile-butadiene copolymer, ethylene-vinyl acetate copolymer; epoxy resin, polyvinyl butyral. Solvent-based resins such as polyvinyl chloride, polyvinyl acetate, etc .; composed mainly of at least one of the above-mentioned water-soluble resins, etc., but if necessary, an inorganic pigment or a water-proofing agent may be added. it can. The structure of the back coat layer is almost the same as that of the under layer.

When used as an electrophotographic plate,
In order to further reduce the background stain of the printing original plate of the present invention, the image receiving layer as the printing original plate has a volume resistivity of 10 ⁸ to 1 1.
0 ¹³ so that [Omega] cm, the image-receiving layer, the under layer and /
Alternatively, a conductive agent can be added to the back coat layer.

The conductive agent may be either an inorganic type or an organic type, and may be used alone or in combination of two or more kinds. As the inorganic type, for example, Na,
Salts of monovalent metals such as K and Li, Mg, Ca, Ba, Zn,
Examples thereof include salts or oxides of polyvalent metals such as Ti, Co, Ni, Zr, Al and Si, and ammonium salts. The organic compound may be either a low molecular weight compound or a high molecular weight compound, and examples thereof include compounds conventionally used as a conductive agent, an antistatic agent or a surfactant. For example, metal soap (for example, metal salt of organic carboxylic acid, sulfonic acid, phosphonic acid, etc.), quaternary salt compound (quaternary ammonium salt, phosphonium salt, etc.), anionic surfactant,
Nonionic surfactant, cationic surfactant, alcohol compound (for example, crystalline compound such as acetylene-1,2-diol, xylylenediol, bisphenol A)
Known materials such as the above can be used alone or in an arbitrary mixture of two or more kinds.

The amount of the conductive agent added is 3 to 40% by weight, preferably 5 to 20% by weight, based on the amount of the binder resin used in each layer. In order to prepare the direct drawing type lithographic printing plate precursor of the invention, generally, on one surface of the support, a solution containing an under layer component is applied and dried to form an under layer, and then an image receiving layer component is included. The solution may be applied and dried to form an image receiving layer, and if necessary, a solution containing a backcoat layer component may be applied and dried on the other surface to form a backcoat layer. Incidentally image receiving layer, the under layer, the coating amount of the backcoat layer are each 1 to 30 g / m ^2, in particular 6~20g / m ²
Is appropriate.

A printing plate using the direct drawing type lithographic printing plate precursor of the present invention is prepared by forming and fixing an image on the direct drawing type lithographic printing plate precursor having the above-mentioned constitution by a known technique,
The non-image area is desensitized by surface-treating it with a desensitizing solution. Desensitization of zinc oxide has hitherto been carried out as a desensitizing treatment liquid of this type, as a ferrocyanine salt, a cyanide-containing treatment liquid containing a ferricyanide as a main component, an amminecobalt complex, phytic acid and its derivatives, and a guanidine derivative. There are known cyan-free treatment liquids containing as a main component, treatment liquids containing inorganic acids or organic acids that form chelates with zinc ions as main components, treatment liquids containing a water-soluble polymer, and the like. For example, as cyanide-containing treatment liquids, JP-B-44-9045, JP-A-46-39403, JP-A-52-76101, JP-A-57-107889, and JP-A-54-107489.
The thing described in each gazette, such as -117201, is mentioned.

As the treatment liquid containing a phytic acid compound,
JP-A Nos. 53-83807, 53-83805, 58-102102, 53-109701 and 5
Nos. 3-127003, 54-2803, 54-4
Those described in Japanese Patent No. 4901 and the like are listed. Examples of the treatment liquid containing a metal complex compound such as a cobalt complex include those described in JP-A-53-104301, JP-A-53-140103, JP-A-54-18304 and JP-B-43-28404. As the treatment liquid containing an inorganic or organic acid, Japanese Patent Publication No. 39-13702 and 40-103.
No. 08, No. 43-28408, No. 40-26124
And Japanese Patent Application Laid-Open No. 51-118501. As the guanidine compound-containing treatment liquid,
Examples thereof include those described in JP-A-56-111695.

The treatment liquid containing a water-soluble polymer is described in JP-A Nos. 52-126302 and 52-134501.
Nos. 53-49506, 53-59502, 53
-104302, JP-B-38-9665, 39-
No. 22263, No. 40-763, No. 40-2202
And Japanese Patent Application Laid-Open No. 49-36402. In any of the above desensitizing treatments,
Zinc oxide in the surface layer is ionized to zinc ions,
It is considered that these ions cause a chelation reaction with a compound forming a chelate in the desensitizing treatment liquid to form a zinc chelate, which is deposited in the surface layer to be hydrophilized.

[0060]

EXAMPLES The present invention will be described in detail with reference to examples below, but the contents of the present invention are not limited to these examples. Example 1 and Comparative Example 1 200 g of dry zinc oxide (manufactured by Shodo Kagaku Co., Ltd.), 27 g of a binder resin (A-1) having the following structure, a binder resin (A-2) 3.
A mixture of 0 g and 310 g of toluene was dispersed for 30 minutes at a rotation speed of 1 × 10 ⁴ rpm using a wet disperser Kedemi Mill KDM7-4 type (manufactured by Rigaku Kogyo Co., Ltd.), and the compound having the following structure [ P-1] 5 g, a mixed solution of 10 g of water and 25 g of methanol was added, and then the rotation speed was 5 ×.
The composition was dispersed at 10 ³ rpm for 20 minutes to obtain a composition for an image receiving layer.

[0061]

Embedded image

A support of ELP-1 type master (trade name, manufactured by Fuji Photo Film Co., Ltd.) used as an electrophotographic lithographic printing plate for light printing was used, and the above composition was placed thereon with a wire bar. And then dried at 100 ° C. for 1 minute to form an image receiving layer having a coating amount of 8 g / m ² to obtain a direct-drawing type lithographic printing original plate.

Comparative Example 1 A direct drawing type lithographic printing plate precursor was prepared in exactly the same manner as in Example 1 except that the compound [P] of the specific example (45) used in Example 1 was omitted. However,
The dispersion conditions were adjusted so that the Bekk smoothness equivalent to that of the image receiving layer of Example 1 was obtained. Using each printing plate precursor of Example and Comparative Example 1 prepared as described above, a plate was prepared by a laser printer using a dry toner as described below, and a desensitizing treatment was performed to prepare a printing plate. As a result, the results shown in Table 1 were obtained.

[0064]

[Table 1]

The evaluation items shown in Table-1 are as follows. Note 1) Smoothness of image receiving layer: The printing original plate was measured for its smoothness (second / 10 cc) using a Beck's smoothness tester (manufactured by Kumagai Riko Co., Ltd.) under the condition of an air capacity of 10 cc.

Note 2) Three-dimensional surface roughness: A printing original plate is measured by a three-dimensional roughness measuring device (SE-3FK, Kosaka Laboratory Ltd. product name) and a three-dimensional roughness analyzing device (SPA-11, (stock). The three-dimensional surface roughness was measured under the following conditions using a) manufactured by Kosaka Laboratory. Measurement condition Measurement length X axis: 2.5 mm, Y axis: 0.4 mm Axis sampling pitch: 0.05 μm With inclination correction, without cutoff Measured value Surface / center average roughness: SRa (μm) Average wavelength: Sλa (μm ) These measurements follow the standard of ISO-468, and specifically, for example, Jiro Nara "Measurement and evaluation method of surface roughness"
It is described in detail in General Technology Center Co., Ltd. (published in 1983).

Note 3) Plate making image quality A printing original plate is commercially available as AM-Straight Imaging System: Laser printer using dry toner (AMS
The copy image of the plate-making product obtained through IS ・ 1200-J Plate Setter-trade name-) was visually evaluated using a 20-fold loupe.

Note 4) Printing image quality After the printing original plate was made by the same operation as that of Note 3), a desensitizing treatment liquid (SICS, a product name of Japan AM Co., Ltd.)
Was put into the etcher section of a fully automatic printing machine (AM-2850, trade name of AM Co., Ltd.), and as a dampening solution, a solution prepared by diluting a desensitizing solution (SICS) four times with distilled water was used. The fountain solution was placed in a tray and the ink was used for offset printing, and printing was performed by passing the plate through a printing machine. Print 1
The printed image of the 0th printed matter (ground fog, solid uniformity of image area) was visually evaluated using a 20-fold loupe.

Note 5) Printing durability: Printing was performed in the same manner as in Note 4) above, and the number of prints until the background stain of the printed matter or the lack of the image could be visually determined was examined.

As shown in Table 1, the image-receiving layers of the respective original plates provided on the same support had almost the same Beck's smoothness. Further, when examining the surface roughness of each of the original plates of Example 1 and Comparative Example 1 having different image receiving layers, the central average roughness SRa representing the size of the surface unevenness and the average wavelength S serving as a guide for the interval of the unevenness are shown.
From the respective numerical values of λa, there is not much difference in SRa between the original plate of the present invention having the same Beck smoothness and the original plate of Comparative Example 1, but there is a large difference in Sλa, and the present invention forms unevenness more densely. Was. On the other hand, compounds having chelating ability [P]
In Comparative Example 1 in which no particles were present, the coarse particles were sparsely and unevenly distributed in the surface state. Next, the original plate was actually made, and the surface was desensitized to obtain a printing plate, which was offset-printed.The results were compared and examined. Only the original plate of the present invention showed good plate-making image quality and printing image quality. It was That is, the plate-making product of the present invention obtained by dry toner transfer from a laser printer has no thin lines or missing fine characters,
The solid part is also uniform, no unevenness in toner transfer is observed,
In addition, the non-image area and the background fog caused by the toner scattering were slight, and there was no problem in practical use.

On the other hand, the plate-making product of Comparative Example 1 which did not use the compound [P] had remarkable unevenness in the image area and a large amount of background fog in the non-image area. There wasn't. Next, the original plate is actually made into a printing plate by desensitizing the surface, and offset printing is performed.
When the results were compared and examined, only the original plate of the present invention had good plate-making image quality and print image quality. That is,
The plate-making product of the present invention obtained by dry toner transfer from a laser printer has no thin lines or fine characters, the solid part is uniform, no unevenness in toner transfer is observed, and the non-image part is also a toner. The ground fog caused by the scattering was small and it was good without any practical problems.

On the other hand, in the plate-making product of Comparative Example 1 in which the compound [P] was not used, the unevenness in the image area and the background fog in the non-image area were remarkably low and did not reach a practical level. Next, the plate was desensitized to form a printing plate, and the performance of the plate was evaluated.The printing plate of the present invention showed only fine lines, missing fine characters, and non-uniform solid images. In addition, 3,000 or more good prints having a problem that the ink stains on the non-image area did not practically occur were provided. On the other hand, in Comparative Example 1, the background stain of the non-image portion is generated from the printing,
Even after printing 3000 sheets, it did not change.

From these results, it is considered that there is a close relationship between the characteristics of the image receiving layer due to the zinc oxide particles provided and the image performance in plate making / printing. That is, it seems that only the image receiving layer of the present invention has a relatively uniform particle size distribution and a dense surface irregularity.

Although the Beck's smoothness is almost the same, as can be seen from the three-dimensional surface roughness, the original plate of the present invention is
The unevenness is formed in a dense state. Further, when the non-image area of the non-image area after plate making was observed with an optical microscope with a magnification of 200, the number of scattered toner areas of the background area was 1 mm (1 mm). ² ) The same number as 15 per toner, but when the number of toner particles having a size of 15 μm or more is examined and found, the number of toners of the present invention is as small as 0 to 1,
In each comparative example, the number was 4-5, which was extremely large.

From these facts, when the original plate of the present invention was made into a plate, it was possible to suppress the adhesion of scattered toner to the non-image and to prevent the toner particles from becoming thick even in fixing with a heating roller, and as a result, it was visually observed. It is thought that it had a great influence on the bad dirt of the time. Further, the difference in the background stain between Example 1 and each comparative example in the printed matter corresponds to the size of the scattered toner on the plate-making product, and small scattered toner of 15 μm or less is hydrophilized during the desensitizing treatment, but is coarse. The particle toner remains, causing ink stains. Furthermore, the surface of the hydrophobic zinc oxide has been modified to be hydrophilic, so the wettability of the zinc oxide particle surface with the desensitizing treatment liquid is extremely good. It is considered that even in the desensitizing treatment in which the treatment is carried out and a rapid treatment is carried out, it is easily and sufficiently hydrophilized. As described above, only the printing original plate of the present invention can provide a good printed matter.

Example 2 Dry zinc oxide (SAZEX-2000: Sakai Chemical Industry Co., Ltd.) 100
g, a dispersant (Caribbon L-400: trade name manufactured by Sanyo Kasei Co., Ltd.) 1 g, a compound [P-2] 5 g having the following structure, and a compound (B-1) 2 g having the following structure are dissolved and p is added with aqueous ammonia.
A mixture of 150 g of an aqueous solution adjusted to H4.0 was dispersed with 20 g of glass beads having a diameter of 0.7 to 1 mm using a Dynomill disperser at a rotation speed of 3 × 10 ³ rpm for 30 minutes, and then the glass beads were filtered off. To this dispersion, 15 g (as solid content) of an acrylate emulsion [AE932, trade name of Japan Synthetic Rubber Co., Ltd.] was added as a binder resin, and further dispersed with a homogenizer at 1 × 10 ³ rpm for 1 minute to obtain an image. A receiving layer composition was prepared.

[0077]

Embedded image

Using the support used in Example 1, the above composition was coated thereon with a wire bar, and the temperature was adjusted to 80 ° C.
After drying for 1 minute, an image receiving layer having a coating amount of 10 g / m ² and a Beck smoothness of 55 (sec / 10 cc) was provided.

This printing original plate was prepared in the same manner as in Example 1.
Plate-making, desensitizing treatment was performed to obtain a printing plate, and offset printing was performed. The obtained printed matter had a clear image quality with no stains on the non-image areas, as in Example 1, and had a good printing durability of 3000 sheets or more. In addition, the plate-making image obtained by making a plate using a thermal transfer printer (Write Movell, a product name of Kanto Electronics Co., Ltd.) has a small amount of ink transfer from the ink ribbon to the non-image area, which is a practical problem. It was not enough. In addition, the SICS
A desensitizing treatment was performed with the treatment liquid of No. 1 to prepare a printing plate, and offset printing was performed. The obtained printed matter had a slight non-image stain, which was not a problem in practical use, and the image portion was free of fine lines and fine characters. 100 such good prints
Zero or more sheets were obtained.

Example 3 100 g of wet zinc oxide (AZO), a dispersant (Demol E)
P, 1.5 g (trade name, manufactured by Kao Corporation) (as solid content), 6.4 g of the compound [P-3] having the following structure was dissolved, and a mixture of 150 g of an aqueous solution adjusted to pH 3.0 with aqueous ammonia was used. Rotation speed 6 × 10 ³ rpm using a Dynomill disperser with 150 g of 0.7-1 mm glass beads
After 15 minutes of dispersion, the glass beads were filtered off.

Compound [P-3] N [(CH ₂ ) ₃ N (CH ₂ PO ₃ H ₂ ) ₂ ] ₃ This dispersion was collected by a centrifuge to collect precipitates, washed thoroughly with water, and then subjected to reduced pressure. After drying, 90 g of a solid powder was obtained. A mixture of 100 g of the above treated zinc oxide, 1.2 g of demole EP (as solid content) and 150 g of water, having a diameter of 0.7 to 1 mm
With 150 g of the glass beads of No. 3 in a Dynomill disperser at a rotation speed of 3 × 10 ³ rpm for 30 minutes, the glass beads were filtered off, and the dispersion was used as a binder resin.
Acrylate emulsion [Cevian-A46488,
Daicel Chemical Industries Ltd.] 15 g (as solid content)
Was added and stirred with a stirrer at 1 × 10 ³ rpm for 1 minute,
The resulting dispersion was for an image receiving layer.

This was coated on a support similar to that used in Example 1 using a wire bar and dried at 100 ° C. for 1 minute to give a coating amount of 9 g / m ² and a Beck smoothness of 50 (sec / 10 c).
The image receiving layer of c) was formed. This printing original plate was made into a plate in the same manner as in Example 1 and subjected to a desensitizing treatment to form a printing plate, which was offset printed. The obtained printed matter had a clear image quality with no stains on the non-image areas, as in Example 1, and had a good printing durability of 3000 sheets or more.

Example 4 100 g of wet zinc oxide (AZO, manufactured by Shodo Kagaku Co., Ltd.),
A mixture of 1 g of sodium metaphosphate and 120 g of water was used together with 200 g of glass beads having a particle size of 0.7 to 1 mm with a wet disperser (Dynomill, manufactured by Shinmaru Enterprise Co., Ltd.) at a rotation speed of 5 × 10 ³ rpm to 30 g. After dispersing for a minute, the glass beads were filtered off. This dispersion
After adjusting the pH to 4.0 with a 0.1 N hydrochloric acid aqueous solution, 3.0 g of the compound (P-4) having the following structure was added, and the rotation speed was 1 × 10 ³ r with a homogenizer disperser (manufactured by Nippon Seiki Co., Ltd.). .
After dispersing at pm for 1 minute, the pH of this dispersion was immediately neutralized to 7.0 with a 10% aqueous sodium hydroxide solution.

[0084]

Embedded image

The dispersion was centrifuged with a centrifuge to precipitate zinc oxide particles, the precipitate was taken out by decantation, washed thoroughly with water, and the granules were dried under reduced pressure to obtain 95 g of a white powder. It was The content of the compound [P] in 100 parts by weight of zinc oxide obtained from the result of measuring the Zn / P ratio of this powder by fluorescent X-ray analysis was 5.3 × 10 ⁻³ mol. Which indicates that the reaction proceeded almost quantitatively.

<Preparation of printing original plate> 100 g of the zinc oxide treated above, 0.8 g of sodium metaphosphate and 150 of water.
g mixture of glass beads 17 similar to those used above.
Rotation speed of 5 ×
The dispersion was carried out at 10 ³ rpm for 20 minutes. After separating the glass beads by filtration, 15 g (as solid content) of acrylic emulsion (Nipol LX857, manufactured by Nippon Zeon Co., Ltd.) as a binder resin was added to the dispersion, and the mixture was homogenized at 1 × 10 ³ rpm.
And dispersed for 1 minute to obtain a composition for an image receiving layer. Using the same support as used in Example 1, the above composition was coated thereon with a wire bar and dried at 100 ° C. for 1 minute to form an image receiving layer having a coating amount of 10 g / m ^2. A lithographic printing plate precursor for direct drawing was obtained. This printing original plate was subjected to plate making and desensitization treatment in the same manner as in Example 1 to obtain a printing plate, and offset printing was performed. The obtained printed matter had a clear image quality with no stain in the non-image area as in Example 1, and had a good printing durability of 3000 sheets or more.

Example 5 100 g of the surface-treated zinc oxide used in Example 4, 14 g of a binder resin (A-3) having the following structure, 1.5 g of an acrylic acid resin particle dispersion having the following contents (as solid content), and A mixture of 230 g of toluene was dispersed with a homogenizer disperser at a rotation speed of 1 × 10 ⁴ rpm for 20 minutes.

[0088]

Embedded image

Acrylic acid resin particle dispersion 8 g of acrylic acid, AA-6 [trade name of Toa Gosei Kagaku KK: macromonomer of methyl methacrylate] 2 g, ethylene glycol dimethacrylate 2 g, methyl 3-mercaptopropionate 0.1 g And a mixed solution of 55 g of methyl ethyl ketone were heated to a temperature of 60 ° C. under a nitrogen stream. Add 2,2'-azobis (isovaleronitrile)
0.2 g was added and the reaction was carried out for 3 hours.
g was added and reacted for 4 hours. The obtained dispersion had a reaction rate of 95% and had an average particle size of dispersed resin particles of 0.20 μm and good monodispersibility (particle size measurement: CAPA-50.
0 (product name manufactured by HORIBA, Ltd.).

This dispersion was coated on a ELP-I paper support with a wire bar and dried at a temperature of 100 ° C. for 1 minute to obtain an image with a coating amount of 12 g / m ² and a Beck smoothness of 65 (sec / 10 cc). The receiving layer was formed. This printing original plate was made into a plate in the same manner as in Example 1 and subjected to a desensitizing treatment to form a printing plate, which was offset printed. The obtained printed matter had a clear image quality with no stain on the non-image area as in Example 1.
The printing durability was as good as 3000 sheets or more.

Examples 6 to 17 In place of the compound [P] used in Example 1, 7.0 × 10 ⁻⁴ mol of each compound [P] shown in the following Table II was used, respectively. A lithographic printing plate precursor for direct drawing was prepared in the same manner as in 1. The Bekk smoothness of the surface of each original plate is 45 to
The range was 60 (seconds / 10 cc).

[0092]

[Table 2]

[0093]

EFFECT OF THE INVENTION By using the direct drawing type lithographic printing original plate of the present invention, the offset original plate has excellent desensitizing property which does not cause spot stains as well as uniform stains on the entire surface, Further, a printed matter having a clear image free from printing stains can be obtained by drawing from an electrophotographic copying machine using an electrostatic transfer method.

Claims (4)

[Claims] 1. A direct-drawing type lithographic printing plate precursor having an image-receiving layer on a water-resistant support, wherein the image-receiving layer contains at least one polar group of the following general formula (I). A direct-drawing lithographic printing plate precursor comprising (Compound [P]), zinc oxide and a binder resin. Embedded image 2. The lithographic printing plate precursor for direct plate-making according to claim 1, wherein the compound [P] is contained in an amount of 1 × 10 ⁻⁴ to 1 × 10 ⁻¹ mol per 100 g of zinc oxide. 3. The compound [P] contains 1 to 3 polar groups represented by the general formula (I), and the compound represented by the following general formula (II) to
The direct-drawing lithographic printing plate precursor as claimed in claim 1 or 2, which is at least one selected from water-soluble compounds represented by (VI). Embedded image In the formulas (II) to (VI), R ₁ , R ₂ , X, Y and Z each may have various substituents and may be bonded to each other to form a ring. Represents W represents a hetero atom such as N atom, methine carbon (—CH <) or a cyclic organic residue. 4. Zinc oxide, a binder resin, the compound [P]
4. A direct drawing type lithographic printing plate according to any one of claims 1 to 3, wherein a dispersion comprising at least a dispersion medium and a dispersion medium is coated on a water resistant support to form an image receiving layer. Original plate manufacturing method.