JPH10114167A - Supporting member for planography block and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supporting member having excellent performance in the printing durability when used as a printing block, particularly in anti-fouling property with respect to dot-like stains by specifying the relative load length and the surface average roughness (Ra) of a specific cutting level of a load curve obtained by a stylus type surface roughness shape measuring device. SOLUTION: As a supporting member for a planography block, capable of contacting with a photosensitive layer closely and retaining water excellently, while preventing generation of dot-like stains in printing, one processes so as to have a 90% or more relative load length at a position lower than the cutting level 50% of the load curve obtained by a needle contact type surface roughness shape measuring device by 1.5μm, and a 0.3 to 0.8μm surface average roughness (Ra) is used. In the production of such a supporting member, after successively applied with mechanical roughing, a chemical etching treatment, and a death mat treatment, the surface of an aluminum plate is applied with an electrochemical roughing in an acidic electrolyte mainly containing nitric acid or hydrochloric acid. Then, chemical etching, death mat treatment, and anodic axidation treatment are applied successively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate support and a method for producing the same. The present invention relates to a lithographic printing plate support that does not locally leave a film even when it is present and that is unlikely to have dot-like stains during printing, and a method for producing the same.

[0002]

2. Description of the Related Art In the printing industry in recent years, demands for resource saving, labor saving, high speed, and the like have been further increased, and "printing plates which can be easily printed" which can meet these demands have been demanded. It is important to obtain beautiful printed matter without strict control of printing conditions, especially fountain solution and ink. One of the factors for achieving this is that it is difficult to stain, and in particular, it is difficult for spot-like stains to occur.

Conventionally, an aluminum plate has been widely used as a support for a lithographic printing plate. However, in order to improve the adhesion between the support and the photosensitive layer and to impart water retention to the non-image area, the surface of the support is required. A so-called graining treatment for roughening is performed. Specific means of the graining method include mechanical sand sandblasting, ball graining, wire graining, brushing with a nylon brush and an abrasive / water slurry, and mechanical sanding with a honing grain which sprays the abrasive / water slurry on the surface at high pressure. There is a dressing method, and there is a chemical graining method in which the surface is roughened with an etching agent composed of an alkali, an acid, or a mixture thereof. Also, British Patent No. 896,563, JP-A-53-67507, JP-A-54-14
No. 6,234, and JP-B-48-28123.
No. 3,123,204, a method of combining the mechanical graining method and the electrochemical graining method, the mechanical graining method described in JP-A-56-55261, A method is also known in which the method is combined with a chemical graining method using a saturated aqueous solution of an aluminum salt.

[0004] In order to characterize the shape of the surface subjected to various surface roughening treatments, several prior art documents have been known, for example, US Pat. No. 4,301,22.
No. 9 defines the cumulative frequency distribution of the pit diameter and the center line average roughness, U.S. Pat. No. 3,861,917 defines the depth of the rough surface, and Canadian Patent No. 955,449. The specification specifies the height and diameter of the rough peaks. Also,
German Patent Specification No. 1,813,443 specifies the height difference of the rough surface, and JP-A-55-132294 specifies the average depth (the average value of roughness using a stylus type surface roughness meter). ing.

[0005] However, in these prior arts, although various parameters are specified, both the printing durability and the resistance to contamination when used as a printing plate are satisfied, and in particular, the point of the point-like contamination resistance is reduced. None of which achieved excellent performance.

[0006]

Therefore, the above-mentioned known techniques are insufficient in terms of the difficulty of dot-like contamination, and it is an object of the present invention to find a lithographic printing plate support which can satisfy this performance. Is the purpose.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, the occurrence of dot-like stains has been reduced to an average surface roughness (Ra) of the surface of a lithographic printing plate support. In addition to the above, the present inventors have found that the influence of an extremely deep concave portion existing locally is great, and completed the present invention based on the knowledge. That is, the object of the present invention is to provide (1) a relative load length at a position 1.5 μm lower than a cutting level 50% of a load curve obtained by a stylus type surface roughness profile measuring apparatus of 90% or more, And the surface average roughness (Ra) is 0.3 to
This is achieved by a lithographic printing plate support characterized in that it is 0.8 μm. A similar object is the present invention,
(2) The surface of the aluminum plate is sequentially subjected to mechanical roughening, chemical etching, and desmutting, followed by electrochemical roughening in an acidic electrolyte mainly containing nitric acid or hydrochloric acid, Chemical etching, desmutting,
(1) The method for producing a lithographic printing plate support according to the above (1), wherein the aluminum plate is subjected to a chemical etching treatment and a desmutting treatment, followed by nitric acid. Alternatively, for a lithographic printing plate as described in (1) above, electrochemical surface roughening is performed in an acidic electrolyte mainly composed of hydrochloric acid, and then chemical etching, desmutting, and anodizing are sequentially performed. This is also achieved by a method for producing a support.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The lithographic printing plate support of the present invention will be described below in detail. The support that can be used in the present invention is preferably made of a metal or a composite (aluminum, steel, stainless steel, or the like). The aluminum plate used in the present invention is selected from a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of a different element, or a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign element in the alloy is 10% by weight or less. Aluminum suitable for the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. Thus, the aluminum plate applied to the present invention, the composition is not specified, and conventionally known and used materials, such as JIS A1050, JIS A 1100, JIS A 3103, JI
SA 3005 can be used as appropriate. The thickness of the aluminum plate used in the present invention is approximately 0.1 mm to 0.6 mm.
mm.

The graining method in the present invention is an electrochemical graining method for electrochemical graining in a hydrochloric acid or nitric acid electrolytic solution, a wire brush graining method in which an aluminum surface is scratched with a metal wire, and a polishing ball and an abrasive. A mechanical graining method such as a ball graining method for graining the aluminum surface or a brush graining method for graining the surface with a nylon brush and an abrasive can be used, and any of the above graining methods can be used alone or in combination. Can also.

According to the present invention, the cutting surface of the load curve obtained by the stylus type surface roughness profile measuring device is determined by the mechanical graining method and the electrochemical graining method.
90% relative load length 1.5 μm below 0%
As described above, and the surface average roughness (Ra) is 0.3 to 0.8 μm.
m.

Here, the load curve is obtained as follows. FIG. 1A shows the locus of vertical movement of the probe when the probe of the stylus type surface roughness measuring device is moved by a predetermined distance on the surface of the support. That is, the vertical trajectory of the probe expresses the unevenness of the surface of the support by its cross-sectional shape, and is generally called an extraction curve.
In the figure, a point represented by a symbol L corresponds to the deepest portion of the surface of the support, and a point represented by a symbol H corresponds to a top portion.
Note that the horizontal axis (X) is the moving distance of the probe (unit: μm),
The vertical axis (Z) is the height of the unevenness (unit: μm). Then, this extraction curve is cut at every point (height) on the Z axis, and the peaks present at each cut portion are integrated to obtain a load curve shown in FIG. 1B. In the figure,
The vertical axis (C) is the cutting level (unit:%) corresponding to the Z axis,
The horizontal axis (t _P ) is the ratio of the peak present at each cutting level to the integrated amount of all peaks (hereinafter referred to as relative load length:
%). For example, a point t _P (h) on the abscissa corresponding to the point C (h) on the ordinate indicates a ratio occupied by a convex portion higher than the one-dot chain line h in FIG. The vertical axis corresponds to the difference between the deepest part (L) and the top part (H) of the irregularities on the surface of the support, and the unit in this case is represented by μm.

According to the present invention, in addition to the specification of the surface average roughness (Ra), in the above-mentioned load curve, the cutting level is 50%, in other words, from the midpoint between the deepest part (C) and the top part (H) of the unevenness. The relative load length (C _F1.5 ) at 1.5 μm lower is 9
It has been found that, by using a support having a content of 0% or more, the image forming property of a lithographic printing plate, in particular, the point-like stain is hardly generated. Incidentally, the range of the surface average roughness (Ra) (0.3 to 0.8 μm) is a value which is conventionally regarded as preferable with respect to the adhesion between the photosensitive layer and the support and the water retention, but is more preferable. Is 0.4 to 0.6 μm. A support having a relative load length (C _F1.5 ) of less than 90% can be used even if the surface average roughness (Ra) satisfies the above range or the extremely deep concave portion is localized. When a photosensitive layer is coated on such a support, a small portion or a large portion of the photosensitive layer locally occurs, and after development, these portions are locally left as a film. -Like contamination occurs.

In order to satisfy the relative load length (C _F1.5 ) and the average surface roughness (Ra), graining is performed under the following conditions. For mechanical graining, see Japanese Patent Publication No. 50-
It is suitable to carry out by the method described in JP-A-40047. The approximate diameter of the brush hair is 0.20mm
Suitably, it is in the range of 1.0 mm. The rotation speed of the brush is suitably 100 to 300 rpm, and a support roll having a rubber or metal surface and having good straightness is used. The abrasive slurry liquid is sprayed on the surface of the conveyed aluminum plate by a spray or the like before passing through a brush roll. The brush roll is pressed against the aluminum plate, and the aluminum plate is subjected to a surface roughening treatment between the support roll and the brush roll under a constant pressing condition. From the viewpoint of graining with alumina, aluminum hydroxide, zirconia, pumice, and metal powder, the slurry liquid used has a specific gravity of 2 or more, and the average particle size of the abrasive is 5 to 5.
The thickness of 80 μm is important for obtaining uniform unevenness.

The electrochemical graining can be performed by electrolytic graining described in JP-B-48-28123 and British Patent 896563. Conventionally, the electrolytic graining uses a sinusoidal alternating current, but a special waveform as described in JP-A-52-58602 may be used. Also, JP-A-55-158298 and JP-A-56-158
No. 28898, JP-A-52-58602, JP-A-52-58602
-152302, JP-A-54-85802, JP-A-60-190392, JP-A-58-120531,
JP-A-63-176187, JP-A-60-14739
4, JP-A-1-5889, JP-A-1-280590
JP-A-1-118489, JP-A-1-14859
No. 2, JP-A-1-178496, JP-A-1-1883
No. 95, JP-A-1-154797, JP-A-2-235
794, JP-A-3-260100, JP-A-3-25
No. 3600, JP-A-4-72099, JP-A-4-72
098, JP-A-3-267400, JP-A-1-14
The method described in each publication of No. 1094 can also be applied. Various types of electrolytic cells have been proposed as a power source.
No. 203637, JP-A-56-123400,
JP-A-57-59770, JP-A-53-12738
JP-A-53-32821, JP-A-53-3282
No. 2, JP-A-53-32823, JP-A-55-122
896, JP-A-55-132883, JP-A-62-2
No. 128500, JP-A-1-52100, JP-A-1-52100
52098, JP-A-60-67700, JP-A-1-
230800 and power supplies described in JP-A-3-257199 can be used. However, electrolytic graining using nitric acid is the easiest to obtain the shape of the present invention. The conditions are as follows: nitric acid concentration 5 to 15 g / l, aluminum nitrate concentration 1 to 20 g / l, temperature 30 to 80 ° C., anode Electricity 100 to 700 C / dm ² , power frequency 1 to 1
20 Hz.

The grained aluminum plate is chemically etched with an acid or an alkali. When an acid is used as an etching agent, it takes time to destroy a fine structure, which is disadvantageous in industrially applying the present invention. However, it can be improved by using an alkali as an etching agent. Alkali agents suitably used in the present invention include caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide, and the like. The preferred ranges of concentration and temperature are 1 to 50, respectively. %, 20 to 100 ° C., and a condition in which the amount of Al dissolved is 5 to 20 g / m ³ . After etching, pickling is performed to remove dirt (smut) remaining on the surface. As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borofluoric acid and the like are used. Particularly, in the desmutting treatment after the electrochemical surface roughening treatment, preferably the method described in
50-90 ° C. as described in US Pat.
And a method of alkali etching described in JP-B-48-28123.

The aluminum alloy plate treated as described above can be used as a support for a lithographic printing plate, but may be subjected to further treatment such as anodic oxidation treatment and chemical conversion treatment if necessary. The anodizing treatment can be performed by a method conventionally performed in this field. Specifically, when direct current or alternating current is applied to aluminum in an aqueous solution or a non-aqueous solution by using sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, or a combination of two or more thereof, the surface of the aluminum support is An anodic oxide film can be formed on the substrate. Anodizing conditions vary depending on the electrolytic solution used and cannot be unconditionally determined, but generally the concentration of the electrolytic solution is 1 to 80.
%, Liquid temperature 5-70 ° C, current density 0.5-60 amps / dm
^{2. The} appropriate range is 1 to 100 V for voltage and 10 to 100 seconds for electrolysis time. Among these anodic oxide film treatments, in particular, the method of anodizing at a high current density in sulfuric acid used in the invention described in British Patent No. 1,412,768 and U.S. Pat. The method of anodic oxidation using phosphoric acid as an electrolytic bath described in the specification of Japanese Patent No. 511,661 is preferable.

After the anodic oxidation treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. U.S. Pat.No. 2,714,066 as the hydrophilization treatment used in the present invention,
There is an alkali metal silicate (e.g., sodium silicate aqueous solution) method as disclosed in 3,181,461, 3,280,734 and 3,902,734. In this method, the support is immersed or electrolytically treated in an aqueous solution of sodium silicate. In addition, Japanese Patent Publication No. 36-22
For example, a method of treating with potassium fluoride zirconate disclosed in JP-A-663 and polyvinylphosphonic acid as disclosed in U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689,272 is used. Further, after graining treatment and anodic oxidation, sealing treatment is also preferable. Such a sealing treatment is performed by immersion in hot water and a hot aqueous solution containing an inorganic salt or an organic salt, a steam bath, or the like.

The aluminum plate is provided with an organic undercoat layer if necessary before coating the photosensitive layer. Examples of the organic compound used in the organic undercoat layer include carboxymethyl cellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, and naphthyl. Organic phosphonic acids such as phosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, and organic acids such as phenylphosphoric acid, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid which may have a substituent. Phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acids such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydrochloride of triethanolamine and the like The hydroxy Although selected from such as hydrochloric acid salt of an amine having a group,
You may mix and use 2 or more types.

This organic undercoat layer can be provided by the following method. That is, a method in which a solution obtained by dissolving the above organic compound in water or an organic solvent such as methanol, ethanol, or methyl ethyl ketone or a mixed solvent thereof is coated on an aluminum plate and dried, and a method in which water or methanol, ethanol, methyl ethyl ketone, or the like is used. An aluminum plate is immersed in a solution in which the above organic compound is dissolved in an organic solvent or a mixed solvent thereof to adsorb the organic compound, and thereafter, washed with water or the like and dried to form an organic undercoat layer. Is the way. In the former method, a solution of the above organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 20% by weight.
-5% by weight, the immersion temperature is 20-90 ° C., preferably 25-50 ° C., and the immersion time is 0.1 second-20 minutes,
Preferably it is 2 seconds to 1 minute. The pH of the solution used for this can be adjusted with a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, or an acidic substance such as hydrochloric acid or phosphoric acid. Further, a yellow dye can be added for improving the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the organic undercoat layer after drying is suitably from ² to 200 mg / m2, preferably from 5 to 200 mg / m2.
100 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² .

A photosensitive layer made of a known photosensitive composition is provided on the thus obtained aluminum plate having a hydrophilic surface to obtain a photosensitive lithographic printing plate. As the photosensitive composition used in the photosensitive layer of the present invention, a positive composition mainly containing an o-quinonediazide compound, a diazonium salt, an alkali-soluble diazonium salt, and a monomer mainly containing an unsaturated double bond are used. Negative type photosensitive materials using a photopolymerizable compound and a photocrosslinkable compound containing a cinnamic acid or a dimethylmaleimide group are used. In addition, Tokubiko 37
Nos. 17172 and 38-6961, JP-A-56-1
No. 07246, No. 60-254142, JP-B-59-
No. 36259, No. 59-25217, JP-A-56-1
No. 46145, No. 62-194257, No. 57-14
No. 7656, No. 58-100862, No. 57-161
The electrophotographic photosensitive layer described in No. 863 and the like can also be used. Among the above photosensitive materials, examples of the photopolymerizable compound having an unsaturated double bond-containing monomer as a main component include, for example, US Pat.
Nos. 2,760,863 and 3,060,023 and JP-A-5
A composition comprising an addition-polymerizable unsaturated compound having two or more terminal ethylene groups and a photopolymerization initiator described in JP-A-9-53836 can be used. Examples of negative photosensitive materials containing a photocrosslinkable compound containing a dimethylmaleimide group include, for example, JP-A-52-988 and EP04106.
No. 54, JP-A-3-2888853 and JP-A-4-2
The photosensitive material described in each of Japanese Patent No. 5845 can be cited.

Among these, the o-naphthoquinonediazide compound used as a positive photosensitive composition includes a 1,2-diazonaphthoquinonesulfonic acid and a pyrogallol-acetone resin described in JP-B-43-28403. Esters are preferred. Other suitable orthoquinonediazide compounds include, for example, U.S. Pat.
JP-A-2-96163 and JP-A-2-96165 include esters of 1,2-diazonaphthoquinone-5-sulfonic acid and a phenol-formaldehyde resin described in JP-A Nos. 120 and 3,188,210. There is an ester of 1,2-diazonaphthoquinone-1-sulfonic acid and a phenol-formaldehyde resin described in the official gazette and JP-A-2-96661. Other useful o-naphthoquinonediazide compounds include
Examples include those known in numerous patents and the like. For example, JP-A Nos. 47-5303, 48-63802, 48
-63803, 48-96575, 49-38
Nos. 701, 48-13854, and JP-B-37-180
No. 15, No. 41-11222, No. 45-9610,
No. 49-17481, U.S. Pat.No. 2,797,213,
No. 3,453,400, No. 3,544,323, No. 3,573,917
No. 3,674,495, No. 3,785,825, UK Patent No.
Nos. 1,227,602, 1,251,345, 1,267,005,
1,329,888, 1,330,932, German Patent 854,
Examples thereof include those described in each specification such as No. 890.

Particularly preferred o-naphthoquinonediazide compounds are compounds obtained by reacting a polyhydroxy compound having a molecular weight of 1,000 or less with 1,2-diazonaphthoquinonesulfonic acid. Specific examples of such compounds are described in JP-A-51-139402 and JP-A-58-15094.
No. 8, No. 58-203434, No. 59-165053
No., No. 60-112445, No. 60-134235
No., No. 60-163443, No. 61-118744
Nos. 62-10645, 62-10646, 62-153950, 62-178562, and 6
4-76047, U.S. Patent Nos. 3,102,809 and 3,12
No. 6,281, No. 3,130,047, No. 3,148,983, No.
Nos. 3,184,310, 3,188,210, and 4,639,406, and other publications or specifications. When synthesizing these o-naphthoquinone diacid compounds, it is preferable to react 0.2 to 1.2 equivalents of 1,2-diazonaphthoquinonesulfonic acid chloride with respect to the hydroxyl group of the polyhydroxy compound,
More preferably, the reaction is carried out at 3 to 1.0 equivalent. 1,2-
Cyazonaphthoquinone sulfonic acid chloride includes 1,
2-diazonaphthoquinone-5-sulfonic acid chloride or 1,2-diazonaphthoquinone-4-sulfonic acid chloride can be used. The obtained o-naphthoquinonediazide compound is a mixture of various compounds having different positions and introduced amounts of 1,2-diazonaphthoquinonesulfonic acid ester groups.
The proportion of the diazonaphthoquinone sulfonic acid esterified compound in the mixture (the content of the completely esterified compound) is preferably 5 mol% or more, more preferably 20 to 99 mol%. is there. The amount of these positive-acting photosensitive compounds (including the combinations described above) in the photosensitive composition is suitably from 10 to 50% by weight, more preferably from 15 to 40% by weight.

Although the o-quinonediazide compound alone can form the photosensitive layer, it is preferable to use a resin soluble in alkaline water as a binder. Such resins soluble in alkaline water include novolak resins, such as phenol formaldehyde resins, o-, m- and p-cresol formaldehyde resins, m / p-mixed cresol formaldehyde resins, phenol / cresol ( o-, m-, p-, m /
Any of p- and o / m-mixtures) may be used. Further, a phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, and an acrylic resin containing a phenolic hydroxyl group as disclosed in JP-A-51-34711 can also be used. Other suitable binders include copolymers having the following (1) to (13) monomers as their constituent units and usually having a molecular weight of 10,000 to 200,000. (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, for example, N- (4
-Hydroxyphenyl) acrylamide or N- (4
-Hydroxyphenyl) methacrylamide, o-, m-
And p-hydroxystyrene, o-, m- and p-
Hydroxyphenyl acrylate or methacrylate, (2) acrylates and methacrylates having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, (3) acrylic acid, methacrylic acid, maleic anhydride , Unsaturated carboxylic acids such as metaconic acid,

(4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, acrylic acid-2 (Substituted) acrylates such as -chloroethyl, 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate, (5) methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 4-hydroxybutyl methacrylate, (Substituted) methacrylates such as glycidyl methacrylate and N-dimethylaminoethyl methacrylate; (6) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N- Hexylacrylamide, N
-Hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N
-Hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N
Acrylamides such as -phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide Or methacrylamide,

(7) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether; (8) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate; (9) styrenes such as styrene, methyl styrene and chloromethyl styrene; 1
0) vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (11) olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene;
2) N-vinyl pyrrolidone, N-vinyl carbazole,
(13) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- (4-vinylpyridine, acrylonitrile, methacrylonitrile, etc.) Acrylamides such as [1- (3-aminosulfonyl) naphthyl] acrylamide, N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacryl Methacrylamides such as amide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide, and o Aminosulfonylphenyl acrylate, m- aminosulfonylphenyl acrylate,
p-aminosulfonylphenyl acrylate, 1- (3
-Aminosulfonylphenylnaphthyl) unsaturated sulfonamides such as acrylates such as acrylate, o-aminosulfonylphenylmethacrylate, m
Unsaturated sulfonamides such as methacrylic esters such as -aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate and 1- (3-aminosulfonylphenylnaphthyl) methacrylate;

Further, a monomer copolymerizable with the above monomer may be copolymerized. In addition, a copolymer obtained by copolymerization of the above-mentioned monomers modified with, for example, glycidyl acrylate or glycidyl methacrylate is also included, but is not limited thereto. The copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the copolymer preferably has an acid value of 0.
-10 meq / g, more preferably 0.2-5.0 meq / g
g. The preferred molecular weight of the copolymer is 10,000 to 10
It is ten thousand. If necessary, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, and an epoxy resin may be added to the copolymer. Such alkali-soluble polymer compounds may be used alone or in combination of two or more, and are used in an amount of 80% by weight or less of the entire photosensitive composition. Further, U.S. Pat.
As described in US Pat. No. 3,279, the use of a condensate of phenol having a C3-8 alkyl group as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, with formaldehyde is not possible. It is preferable in order to improve the oil sensitivity. It is preferable to add a cyclic acid anhydride, a phenol, or an organic acid to the photosensitive composition of the present invention in order to increase sensitivity.

As the cyclic acid anhydride, US Pat. No. 4,115,12
No. 8, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-
Endooxy-Δ4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride,
Pyromellitic anhydride and the like can be used. As phenols, bisphenol A, p-nitrophenol, p
-Ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ',
4 "-trihydroxy-triphenylmethane, 4,
4 ', 3 ", 4"-tetrahydroxy-3,5,3',
5'-tetramethyltriphenylmethane and the like. Further, as the organic acids, JP-A-60-88942
Sulfonic acids, sulfinic acids, alkyl sulfates, and the like described in JP-A-2-96755 and JP-A-2-96755.
Examples include phosphonic acids, phosphoric esters and carboxylic acids, and specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid,
Ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 1,4 −
Cyclohexene-2,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like. The proportion of the cyclic acid anhydrides, phenols and organic acids in the photosensitive composition is from 0.05 to
It is preferably 15% by weight, more preferably 0.1 to 5% by weight.

The photosensitive composition of the present invention contains a nonionic interface as described in JP-A-62-251740 in order to increase the stability of processing under development conditions (so-called development latitude). An activator and an amphoteric surfactant such as those described in JP-A-59-121044 and JP-A-4-13149 can be added. Specific examples of nonionic surfactants include
Sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride, polyoxyethylene sorbitan monooleate,
And polyoxyethylene nonyl phenyl ether. Specific examples of the amphoteric surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N
-Tetradecyl-N, N-betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and alkyl imidazoline type (for example, trade name Levon 15, manufactured by Sanyo Chemical Co., Ltd.). The proportion of the nonionic surfactant and the amphoteric surfactant in the photosensitive composition is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

In the photosensitive composition of the present invention, a printing-out agent for obtaining a visible image immediately after exposure, and a dye or pigment as an image coloring agent can be added. Representative examples of the printing-out agent include a combination of a compound that releases an acid upon exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, JP-A-50-3620
Nos. 9 and 53-8128.
A combination of a naphthoquinonediazide-4-sulfonic acid halogenide and a salt-forming organic dye;
Nos. 54-74728, 60-3626, 6
Combinations of trihalomethyl compounds and salt-forming organic dyes described in JP-A Nos. 1-143748, 61-151644 and 63-58440 can be exemplified. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent stability over time and give clear print-out images.

As the colorant for the image, other dyes can be used in addition to the salt-forming organic dyes described above. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. 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 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) and the like. Further, Japanese Patent Application Laid-Open No.
The dyes described in JP 93247 A are particularly preferred.

The photosensitive composition is dissolved in a solvent capable of dissolving the above-mentioned components, and applied on an aluminum plate as a support.
The solvent used herein is described in JP-A-62-2517.
An organic solvent as described in JP-A-39 is used alone or as a mixture. The photosensitive composition is dissolved and dispersed at a solid content concentration of 2 to 50% by weight, and coated on a support.
Dried. The amount of the photosensitive composition layer (photosensitive layer) applied on the support varies depending on the application, but is generally preferably 0.3 to 4.0 g / m ^{2 in} terms of the weight after drying. . As the amount of coating decreases, the amount of exposure for obtaining an image may be small, but the film strength is reduced. As the coating amount increases, the exposure amount is required but the photosensitive film becomes strong. For example, when used as a printing plate, a printing plate having a high printable number (high printing durability) can be obtained. A surfactant for improving the coated surface quality, for example, a fluorine-based surfactant described in JP-A-62-170950 can be added to the photosensitive composition. A preferable addition amount is 0.001 to 1.0% by weight of the whole photosensitive composition.
And more preferably 0.005 to 0.5% by weight.

Next, as the photosensitive composition of the negative PS plate, those having a photosensitive layer containing a photosensitive diazo compound, a photopolymerizable photosensitive layer, a photocrosslinkable photosensitive layer and the like can be mentioned.
Of these, the photocurable photosensitive copying material comprising a photosensitive diazo compound will be described in detail with reference to examples. As the photosensitive diazo compound, a diazo resin obtained by condensing an aromatic diazonium salt with an organic condensing agent having a reactive carbonyl group, particularly an aldehyde such as formaldehyde or acetaldehyde or an acetal in an acidic medium is preferably used. The most typical one is a condensate of P-diazodiphenylamine and formaldehyde. The synthesis of these diazo resins is described, for example, in U.S. Pat.No. 2,678,498,
Nos. 3,050,502, 3,311,605 and 3,277,
No. 074. Further, as the photosensitive diazo compound, a co-condensed diazo compound of an aromatic diazonium salt described in JP-B-49-48001 and a substituted aromatic compound not containing a diazonium group is preferably used, and among them, a carboxyl group or a hydroxyl group is preferred. A co-condensed diazo compound with an aromatic compound substituted with such an alkali-soluble group is preferred. Further, JP-A-4-18559, JP-A-4-190361 and JP-A-4-172353.
Also, a photosensitive diazo compound obtained by condensing an aromatic diazonium salt with a reactive carbonyl compound having an alkali-soluble group described in JP-A No. 5-2,097 is preferably used. As a counter anion of these diazonium salts, there is a diazo resin using a mineral acid such as hydrochloric acid, hydrobromic acid, sulfuric acid and phosphoric acid or an inorganic anion such as a double salt with zinc chloride, but it is substantially water-insoluble and organic. Solvent-soluble diazo resins are particularly preferred. Such preferred diazo resins are described in detail in JP-B-47-1167 and U.S. Pat. No. 3,300,309.

Further, JP-A-54-98613 and JP-A-56-98613 describe the same.
A diazo resin having a counter anion of a halogenated Lewis acid such as tetrafluoroboric acid or hexafluorophosphoric acid and a perhalic acid such as perchloric acid or periodic acid as described in JP-A-121031 is preferably used. Can be
JP-A-58-209733 and JP-A-62-1775.
A diazo resin having a long chain alkyl group-containing sulfonic acid as a counter anion described in JP-A Nos. 31 and 63-262643 is also preferably used. The photosensitive diazo compound is contained in the photosensitive layer in an amount of 5 to 50% by weight, preferably 8 to 20% by weight. The photosensitive diazo compound is preferably used in combination with a lipophilic polymer compound soluble or swellable in alkaline water as a binder. Such lipophilic polymer compounds are the same as (1) to (3) described above in connection with the positive photosensitive composition described above.
Copolymers having a molecular weight of usually 10,000 to 200,000 having a monomer represented by (13) as a structural unit can be exemplified, and copolymers having a monomer represented by (14) or (15) below as a structural unit are further exemplified. Polymerized polymer compounds can also be used. (14) maleimide, N-acryloylacrylamide, N-acetylacrylamide, N-propionylacrylamide, N- (p-chlorobenzoyl) acrylamide, N-acetylacrylamide, N-acryloylmethacrylamide, N-acetylmethacrylamide,
Unsaturated imides such as N-propionyl methacrylamide, N- (p-chlorobenzoyl) methacrylamide,
(15) N- [2- (acryloyloxy) -ethyl]
Unsaturated monomers having a crosslinkable group in the side chain such as -2,3-dimethylmaleimide, N- [6- (methacryloyloxy) -hexyl] -2,3-dimethylmaleimide and vinyl cinnamate;

Further, a monomer copolymerizable with the above monomer may be copolymerized. In addition, a copolymer obtained by copolymerization of the above-mentioned monomers modified with, for example, glycidyl acrylate or glycidyl methacrylate is also included, but is not limited thereto. The copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the copolymer preferably has an acid value of 0.
-10 meq / g, more preferably 0.2-5.0 meq / g
g. The preferred molecular weight of the copolymer is 10,000 to 10
It is ten thousand. If necessary, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, and an epoxy resin may be added to the copolymer. Novolak-type resins, phenol-modified xylene resins, polyhydroxystyrenes, polyhalogenated hydroxystyrenes, and alkali-soluble resins containing phenolic hydroxyl groups as disclosed in JP-A-51-43711 may also be used. it can. Such alkali-soluble polymer compounds can be used alone or in combination of two or more, and usually 40 to 95 in the solid content of the entire photosensitive composition.
It is contained in the range of weight%.

In the photosensitive composition, a sensitizing agent (for example, a half-ester of alcohol of a styrene-maleic anhydride copolymer described in JP-A-55-527) for improving the lipophilicity of an image is used. Compound, novolak resin, p-
A 50% fatty acid ester of hydroxystyrene). Further, a plasticizer for imparting flexibility and abrasion resistance of the coating film is added. For example, butylphthalyl,
Polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate,
Examples include dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid, and tricresyl phosphate is particularly preferred. Further, in the photosensitive composition, for example, phosphoric acid, phosphorous acid, citric acid, oxalic acid, dipicolinic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, 4-methoxy- 2-Hydroxybenzophenone-5-sulfonic acid, tartaric acid and the like are added.

In the photosensitive composition, a printing-out agent for obtaining a visible image immediately after exposure or a coloring matter such as a dye or a pigment as an image coloring agent can be added. As the dye, those which change color by reacting with free radicals or acids are preferably used. For example, Victoria Pure Blue BOH (made by Hodogaya Chemical), Oil Yellow # 1
01, oil yellow # 103, oil pink # 31
2. Oil Red, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY,
Oil Black BS, Oil Black T-505 (all manufactured by Orient Chemical Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Sangoku Chemical Co., Ltd.), Crystal Violet (CI42555), Methyl Violet (CI425)
35), ethyl violet, rhodamine B (CI14
5170B), malachite green (CI4200)
0), methylene blue (CI52015), brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4
-P-diethylaminophenyliminaphthoquinone, triphenylmethane series represented by cyano-p-diethylaminophenylacetanilide, diphenylmethane series, oxazine series, xanthene series, iminonaphthoquinone series, azomethine series or anthraquinone series dyes are colorless to colorless or An example of changing to a different colored tone is given.

On the other hand, examples of the color changing agent that changes from colorless to colored include leuco dyes and, for example, triphenylamine, diphenylamine, o-chloroaniline, 1,2,2,
3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p'-bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p,
p ', p "-tris-dimethylaminotriphenylmethane, p, p'-bis-dimethylaminodiphenylmethylimine, p, p', p" -triamino-o-methyltriphenylmethane, p, p'-bis -Dimethylaminodiphenyl-4-anilinonaphthylmethane, p, p ', p "
Primary or secondary arylamine dyes represented by -triaminotriphenylmethane. Particularly preferred are triphenylmethane-based and diphenylmethane-based dyes, more preferred are triphenylmethane-based dyes, and particularly Victoria Pure Blue BOH. The above-mentioned dye is usually about 0.5 to 10% by weight in the photosensitive composition,
More preferably, the content is about 1 to 5% by weight.

In the photosensitive composition, cyclic acid anhydrides, phenols, organic acids and higher alcohols can be added in order to enhance developability. The photosensitive composition is
The above components are dissolved in a solvent that dissolves the components and applied on an aluminum plate as a support. As the solvent used here, an organic solvent described in JP-A-62-251739 may be used alone or as a mixture. The photosensitive composition is dissolved and dispersed at a solid content concentration of 2 to 50% by weight, coated on a support and dried. The amount of the photosensitive composition layer (photosensitive layer) to be coated on the support varies depending on the application, but is generally from 0.3 to 0.3 as a weight after drying.
4.0 g / m ² is preferred. As the amount of coating decreases, the amount of exposure for obtaining an image may be small, but the film strength is reduced. As the coating amount increases, the exposure amount is required but the photosensitive film becomes strong. For example, when used as a printing plate, a printing plate having a high printable number (high printing durability) can be obtained. A surfactant for improving the coated surface quality can be added to the photosensitive composition as in the case of the positive photosensitive composition described above. In the production of a photosensitive lithographic printing plate, either the back coat layer on the back surface or the photosensitive composition layer on the front surface may be coated on the support first, or both may be coated simultaneously.

On the back surface of the support of the photosensitive lithographic printing plate (PS plate) of the present invention, a coating layer (hereinafter referred to as a coating layer) made of an organic polymer compound for preventing the photosensitive layer from being damaged when superposed. A back coat layer is provided as needed. As a main component of the back coat layer, at least one resin selected from the group consisting of a saturated copolymerized polyester resin, a phenoxy resin, a polyvinyl acetate resin and a vinylidene chloride copolymerized resin having a glass transition point of 20 ° C. or higher is used. The saturated copolymerized polyester resin is composed of a dicarboxylic acid unit and a diol unit. Examples of the dicarboxylic acid unit of the polyester used in the present invention include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, tetrabromophthalic acid and tetrachlorophthalic acid; adipic acid, azelaic acid, succinic acid, oxalic acid and suberic acid And saturated aliphatic dicarboxylic acids such as sebacic acid, malonic acid and 1,4-cyclohexanedicarboxylic acid.

The back coat layer further includes a dye or pigment for coloring, a silane coupling agent for improving adhesion to an aluminum support, a diazo resin composed of a diazonium salt, an organic phosphonic acid, an organic phosphoric acid and a cation. A suitable polymer such as a wax, a higher fatty acid, a higher fatty acid amide, a silicone compound composed of dimethylsiloxane, a modified dimethylsiloxane, a polyethylene powder and the like, which are usually used as a slipping agent, are added as appropriate. Basically, the thickness of the back coat layer may be any thickness that does not damage the photosensitive layer even without interleaving paper, and is preferably in the range of 0.01 to 8 μm. If the thickness is less than 0.01 μm, it is not possible to prevent abrasion of the photosensitive layer when the PS plates are handled in an overlapping manner. If the thickness exceeds 8 μm, during printing, the back coat layer swells due to chemicals used around the printing plate, and the thickness fluctuates,
The printing pressure may change to deteriorate the printing characteristics. Various methods can be applied to coat the back coat layer on the back surface of the aluminum support. For example, a solution in an appropriate solvent, or a method of coating and drying as an emulsified dispersion, for example, a method in which a preliminarily formed film is bonded to an aluminum support with an adhesive or heat and a melt extruder is used to form a molten film. A method of forming and bonding the mixture to a support may be mentioned, but the most preferable method for securing the above-mentioned coating amount is a method of applying a solution and drying. As the solvent used here, an organic solvent described in JP-A-62-251739 may be used alone or as a mixture.

On the surface of the photosensitive layer provided as described above, a mat layer is provided in order to shorten the evacuation time in the close contact exposure using a vacuum printing frame and to prevent printing blur. Specifically, a method of providing a mat layer as described in JP-A-50-125805, JP-B-57-6582 and JP-B-61-28986 is described in JP-B-62-62337. And a method of thermally fusing such a solid powder. The average diameter of the mat layer used in the present invention is preferably 100 μm or less,
If the average diameter is larger than this, when the PS plates are stored in layers, the contact area between the photosensitive layer and the back coat layer increases, the slipperiness is reduced, and the surfaces of both the photosensitive layer and the back coat layer are scratched. easy. The average height of the mat layer is 10μ
m or less, more preferably 2 to 8 μm.
If the average height is higher than this range, it is difficult to form a fine line, and highlight dots are reduced, which is not preferable in tone reproduction. If the average height is 2 μm or less, the vacuum adhesion is insufficient and burning is caused. The coating amount of the mat layer is preferably from 5 to 200 mg / m ^2, more preferably from 20~150mg / m ^2. If the coating amount is larger than this range, the contact area between the photosensitive layer and the back coat layer increases, causing abrasion, and if smaller than this, the vacuum adhesion becomes insufficient.

The PS plate thus obtained is passed through a transparent original image using a carbon arc lamp, a mercury lamp, a metal halide lamp,
After being exposed by an actinic ray using a xenon lamp, a tungsten lamp or the like as a light source, it is developed. As the developer and replenisher for the PS plate, conventionally known aqueous alkali solutions can be used. For example, sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, potassium And inorganic alkali agents such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine and pyridine are also used.

These alkaline agents are used alone or in combination of two or more. Among these alkali agents, a silicate aqueous solution such as sodium silicate or potassium silicate is particularly preferable as a developer for a positive PS plate. The reason is that the silicon oxide SiO
₂ and the ratio of alkali metal oxide M ₂ O (generally [Si /
This is because the developability can be controlled by the molar ratio of [M ₂ O]) and the concentration.
SiO ₂ and N as disclosed in
The molar ratio of a ₂ O is 1.0 to 1.5 (that is, [SiO ₂ ] /
An aqueous solution of sodium silicate in which the content of SiO ₂ in which [Na ₂ O] is 1.0 to 1.5) is 1 to 4% by weight, as described in JP-B-57-727, [Si
O ₂ ] / [M] is 0.5 to 0.75 (that is, [SiO ₂ ]
/ A [M ₂ O] is 1.0 to 1.5), the SiO ₂ concentration is at least 20% based on the total alkali metal gram atoms present therein and from 1 to 4 wt% An aqueous solution of an alkali metal silicate containing potassium is preferably used.

Further, when the PS plate is developed using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than the developing solution is added to the developing solution, so that the developing solution in the developing tank for a long time is added. It is known that a large number of PS plates can be processed without replacing the PS plates. This replenishment system is also preferably applied in the present invention. For example, as disclosed in JP-A-54-62004, the ratio of SiO ₂ / Na ₂ O in a developer is 1.0 to 1.5 (that is, [SiO ₂ ] / [Na ₂ O] is 1). 0.0 to 1.5), wherein an aqueous solution of sodium silicate having an SiO ₂ content of 1 to 4% by weight is used, and continuously or intermittently depending on the throughput of the positive photosensitive lithographic printing plate. When the molar ratio of SiO ₂ / Na ₂ O is 0.5 to 1.5 (that is, [SiO ₂ ] / [Na
_{How 2} O] is added aqueous sodium silicate solution of 0.5 to 1.5) to (replenisher) in the developer, and further, JP-B-57
[SiO ₂ ] /
[M] is 0.5 to 0.75 (that is, [SiO ₂ ] / [M
₂ O] is 1.0 to 1.5), and an alkali metal silicate developer having a SiO ₂ concentration of 1 to 4% by weight is used. Si
O ₂ ] / [M] is from 0.25 to 0.75 (ie [SiO
₂ ] / [M ₂ O] is from 0.5 to 1.5), and both the developer and the replenisher have at least 20% of gram atoms of total alkali metal present therein. A developing method comprising potassium is preferably used.

When an alkali metal silicate is used as such a replenisher, its molar ratio [SiO ₂ ] / [M ₂
O], the replenisher becomes more active,
Since the replenishment amount can be made small, the running cost and the amount of waste liquid are reduced, which is preferable. However, it is known that the aluminum of the support of the PS plate dissolves with the activation, and insolubles are generated in the developer. Such a developer having a high activity has a SiO ₂ / M molar ratio of 0.7 to 0.7.
1.5, an aqueous solution of an alkali metal silicate having a SiO ₂ concentration of 1.0 to 4.0% by weight, and a replenisher having a molar ratio of SiO ₂ / M ₂ O of 0.3. A system in which the concentration of SiO ₂ is 0.5 to 4.0% by weight and is an aqueous solution of an alkali metal silicate is preferably used. The developer and replenisher used for the development of the positive and negative PS plates include various interfaces as necessary for the purpose of accelerating or suppressing the developing property, dispersing the developing residue and increasing the ink affinity of the printing plate image area. Activators and organic solvents can be added.
Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and glycerin fatty acid partial esters. , Sorbitan fatty acid partial esters,
Pentaerythritol fatty acid partial esters, propylene glycol monofatty 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 oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, and trialkylamine oxides, fatty acid salts, abietic acid salts,
Hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, linear alkylbenzenesulfonates, branched alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates, polyoxy Ethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfate esters of fatty acid alkyl esters, alkyl sulfates salts,

Polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates ethylene salts, alkyl phosphate esters, polyoxyethylene alkyl ether phosphorus Acid ester salts, polyoxyethylene alkyl phenyl ether phosphate ester salts, partially saponified styrene / maleic anhydride copolymer, partially saponified olefin / maleic anhydride copolymer, naphthalene styrene formalin condensate Surfactants, such as anionic surfactants, cationic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylenepolyamine derivatives Carboxy betaines, aminocarboxylic acids, sulfobetaines, such amino acid esters, amphoteric surfactants such as imidazolines. Among the surfactants mentioned above, the term "polyoxyethylene" can be read as a polyoxyalkylene such as polyoxymethylene, polyoxypropylene, or polyoxybutylene, and these surfactants are also included.

Further preferred surfactants are fluorine-based surfactants containing a perfluoroalkyl group in the molecule. Such fluorosurfactants include perfluoroalkyl carboxylate, perfluoroalkyl sulfonate, anionic type such as perfluoroalkyl phosphate, amphoteric type such as perfluoroalkyl betaine,
Cationic and perfluoroalkylamine oxides such as perfluoroalkyltrimethylammonium salts, perfluoroalkylethylene oxide adducts, oligomers containing perfluoroalkyl and hydrophilic groups,
Non-ionic types such as oligomers containing perfluoroalkyl groups and lipophilic groups, oligomers containing perfluoroalkyl groups, hydrophilic groups and lipophilic groups, and urethanes containing perfluoroalkyl groups and lipophilic groups are included. The above surfactants can be used alone or in combination of two or more, and are added to the developer in an amount of 0.001 to 10% by weight, more preferably 0.01 to 5% by weight.

Suitable organic solvents are those having a solubility in water of about 10% by weight or less, preferably 5% by weight or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-1
-Butanol, 2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol and 4 -Methylcyclohexanol, N-phenylethanolamine, N-phenyldiethanolamine and the like. The content of the organic solvent is 0.1 to 5% by weight based on the total weight of the used liquid.
It is. The amount used is closely related to the amount used of the surfactant, and it is preferable to increase the amount of the surfactant as the amount of the organic solvent increases. This is because when the amount of the surfactant is small and the amount of the organic solvent is large, the organic solvent is not completely dissolved, and therefore, it is impossible to expect good developing property.

A reducing agent can be further added to the developer and replenisher used for the development of the PS plate. This is to prevent stains on the printing plate, and is particularly effective when developing a negative PS plate containing a photosensitive diazonium salt compound. Preferred organic reducing agents include phenolic compounds such as thiosalicylic acid, hydroquinone, metol, methoxyquinone, resorcin, and 2-methylresorcin; and amine compounds such as phenylenediamine and phenylhydrazine. Further preferred inorganic reducing agents include sodium salts, potassium salts, and ammonium salts of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, bisulfite, diphosphite, thiosulfate and dithionite. Salts and the like can be mentioned. Among these reducing agents, sulfites are particularly excellent in the stain prevention effect. These reducing agents are preferably used in a developing solution at the time of use.
It is contained in the range of 0.5 to 5% by weight.

An organic carboxylic acid can be further added to the developer and the replenisher. Preferred organic carboxylic acids are aliphatic and aromatic carboxylic acids having 6 to 20 carbon atoms. Specific examples of the aliphatic carboxylic acid include caproic acid, enantiic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are alkanoic acids having 8 to 12 carbon atoms. . In addition, unsaturated fatty acids having a double bond in the carbon chain or branched fatty acids may be used. As the aromatic carboxylic acid, a compound in which a carboxyl group is substituted on a benzene ring, a naphthalene ring, an anthracene ring, or the like, specifically, o-chlorobenzoic acid, p-chlorobenzoic acid,
o-hydroxybenzoic acid, p-hydroxybenzoic acid, o
-Aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid,
2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid,
1-hydroxy-2-naphthoic acid, 3-hydroxy-2
-Naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-
There are naphthoic acid and 2-naphthoic acid, and hydroxynaphthoic acid is particularly effective. The above aliphatic and aromatic carboxylic acids are preferably used as a sodium salt, a potassium salt or an ammonium salt in order to enhance water solubility.
The content of the organic carboxylic acid in the developer used in the present invention is not particularly limited, but if the content is less than 0.1% by weight, the effect is not sufficient, and if it is 10% by weight or more, the effect cannot be further improved. In addition, dissolution may be hindered when another additive is used in combination. Therefore, the preferred addition amount is 0.1 to 10% by weight, more preferably 0.5 to 4% by weight, based on the developer used.

The developer and the replenisher may further contain, if necessary, a conventionally known compound such as an antifoaming agent, a water softener and an organic boron compound described in Japanese Patent Publication No. 1-57895. Can be. Examples of water softeners include polyphosphoric acid and its sodium, potassium and ammonium salts, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid Aminopolycarboxylic acids such as acetic acid and 1,3-diamino-2-propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonate), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylene Phosphonic acid), triethylenetetraminehexa (methylenephosphonic acid), hydroxyethylethylenediaminetri (methylenephosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid and their sodium salts, potassium salts and ammonium salts.

The optimum value of such a water softener varies depending on its chelating power, the hardness of the hard water used and the amount of the hard water. 0.01 to 5% by weight, more preferably 0.0
It is in the range of 1-0.5% by weight. If the added amount is less than this range, the intended purpose is not sufficiently achieved, and if the added amount is more than this range, adverse effects on the image area such as color omission appear. The remaining component of the developer and replenisher is water, but may optionally contain various additives known in the art. It is advantageous from the viewpoint of transportation that the developing solution and the replenishing solution are concentrated solutions having a smaller water content than at the time of use, and are diluted with water at the time of use. The degree of concentration in this case is suitably such that each component does not cause separation or precipitation.

The PS plate thus developed is post-treated with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. These treatments can be used in various combinations for the post-treatment of the PS plate of the present invention. In recent years, in the plate making and printing industries, automatic developing machines for PS plates have been widely used in order to streamline and standardize plate making operations. The automatic developing machine generally includes a developing section and a post-processing section, and includes a device for transporting a PS plate, each processing solution tank and a spray device, and the exposed PS.
While the plate is being conveyed horizontally, each processing solution pumped up by a pump is sprayed from a spray nozzle for development processing. Recently, a method has been known in which a PS plate is immersed and transported in a processing liquid tank filled with a processing liquid by a guide roll in the liquid or the like. In such an automatic processing, the processing can be performed while replenishing each processing liquid with a replenisher according to the processing amount, the operating time, and the like.

Hereinafter, the lithographic printing plate support of the present invention will be further described with reference to Examples and Comparative Examples. (Examples 1 to 3, Comparative Examples 1 and 2) As shown in Table 1, the aluminum plate (thickness 2
(40 μm), followed by alkali etching, desmutting, electrolytic etching, alkali etching, desmutting, and anodizing. The load curve and the average surface roughness (Ra) of the thus treated aluminum plate were determined using a surface roughness profile measuring device (Surfcom 570A, manufactured by Tokyo Seimitsu). Table 1 also shows the relative load length (C _F1.5 ) and the average surface roughness (Ra) at 1.5 μm below the cut level of 50% in the above load curve.

[0056]

[Table 1]

Next, the following photosensitive composition was applied to form a photosensitive layer. (Photosensitive composition) Based on the method described in Example 1 of JP-B-61-28986, on the photosensitive layer thus coated, (methyl methacrylate / ethyl acrylate / sodium acrylate = 68/20) / 12) was electrostatically sprayed with the aqueous copolymer solution to form a mat layer.

The photosensitive lithographic printing plate thus prepared is passed through a transparent positive film in a vacuum frame.
50m from a distance of 3m by a metal halide lamp of 3kw
After exposure for 2 seconds, Si ₂ O / Na
5.26% of sodium silicate with a molar ratio of ₂ O of 1.74
The aqueous solution (pH = 12.7) was processed by passing it through an automatic developing machine, Stavlon 900D, manufactured by Fuji Photo Film Co., Ltd., in which FR-3 (1: 7) manufactured by Fuji Photo Film Co., Ltd. was charged as a rinsing liquid. These positive photosensitive lithographic printing plates were evaluated for printing. The printing machine is Heidelberg SOR
-KZ, dampening water is EU-3 manufactured by Fuji Photo Film Co., Ltd.
(1: 100) to which 10% of isopropanol was added, and DIC Trans (S) was used for the ink.

The print evaluation of dot stains was performed by visually observing the printed matter when the amount of dampening water was reduced until immediately before the occurrence of background stains as printing conditions. The following three levels (a total of four levels) were ranked in order, with "O", "△", and "X". The adhesion is
The degree to which the solid image was normally deposited when 50,000 sheets were printed by the printing machine was visually evaluated, and the case where it was not different from the start of printing was marked with “○”, and the case where it was not the same was marked with “×”. Water retention is
When the amount of dampening water was reduced as in the case of evaluation of dot stains as printing conditions, when stains were generated in the non-image part of the shadow part of the halftone dot, if the degree was light, `` ○ '', so If not, it was marked as "x". The evaluation results are also shown in Table 1.

Example 4 An aluminum plate having a thickness of 240 μm was prepared by subjecting an aluminum plate to a nitric acid concentration of 10.2 g / l, an aluminum concentration of 4.5 g / l, a liquid temperature of 50 ° C., and a quantity of electricity of the anode of 300 C / d.
The surface roughening treatment was performed under the condition of m ² . Next, alkali etching, desmutting, electrolytic etching, alkali etching, desmutting, and anodizing treatment were sequentially performed. The load curve and the average surface roughness (Ra) of the thus treated aluminum plate were determined using a surface roughness profile measuring device (Surfcom 570A, manufactured by Tokyo Seimitsu). (C _F1.5 ) of the above load curve was 96, and the average surface roughness (Ra) was 0.60 μm. When the adhesion, the water retention and the point-like stain were evaluated in the same manner as in Examples 1 to 3, the evaluation of the adhesion and the water retention was “○”, and the point-like stain was evaluated as “評 価”.

[0061]

As described above, according to the present invention,
A lithographic printing plate having excellent adhesion between the photosensitive layer and the support and excellent water retention in addition to the difficulty of dot contamination can be obtained.

[Brief description of the drawings]

FIG. 1 shows an extraction curve (FIG. 1A) and a load curve (FIG. 1).
It is a figure for explaining (b)).

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/00 503 G03F 7/00 503 7/09 501 7/09 501

Claims (3)

[Claims] 1. The relative load length at 1.5 μm lower than the cutting level of 50% of the load curve obtained by the stylus type surface roughness measuring device is 90% or more, and the surface average roughness (Ra) is not less than 90%. A lithographic printing plate support having a thickness of 0.3 to 0.8 μm. 2. The surface of an aluminum plate is mechanically roughened.
After chemical etching and desmutting are sequentially performed, electrochemical surface roughening is performed in an acidic electrolyte mainly composed of nitric acid or hydrochloric acid, and then chemical etching, desmutting and anodizing are sequentially performed. The method for producing a lithographic printing plate support according to claim 1, wherein: 3. The surface of an aluminum plate is subjected to a chemical etching treatment and a desmutting treatment in that order, followed by electrochemical surface roughening in an acidic electrolyte mainly composed of nitric acid or hydrochloric acid, followed by chemical etching, The method for producing a lithographic printing plate support according to claim 1, wherein a desmutting treatment and an anodizing treatment are sequentially performed.