JP3276422B2 - Method for producing aluminum support for lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aluminum support for a lithographic printing plate, and more particularly to a method for producing an aluminum support for a lithographic printing plate characterized by a brush graining step.

[0002]

2. Description of the Related Art A lithographic printing method is a printing method that utilizes the fact that water and oil are not essentially mixed. The lithographic printing plate used in the lithographic printing plate receives water and is oily. A region that repels ink (hereinafter, this region is referred to as a “non-image portion”) and a region that repels water and receives oil-based ink (hereinafter, this region is referred to as “image portion”) are formed. The aluminum support used in the lithographic printing plate has excellent hydrophilicity and water retention because its surface is used to carry the non-image area, and furthermore, close contact with the photosensitive layer provided thereon Various contradictory performances such as excellent performance are required. When the hydrophilicity of the support is low, the ink adheres to the non-image area at the time of printing, and so-called background stain occurs. If the water retention of the support is low,
Unless the dampening solution is increased during printing, the clogging of the shadow portion occurs. Therefore, the so-called water width becomes narrow.

In order to obtain an aluminum support having good performance, it is customary to grain the surface of an aluminum plate to give fine irregularities. Examples of the graining include mechanical graining methods such as ball graining, brush graining, wire graining, and blast graining, and electrolytic roughening in which an aluminum plate is electrolytically etched in an electrolytic solution containing hydrochloric acid and / or nitric acid. And a composite surface roughening method combining a mechanical surface roughening method and an electrolytic surface roughening method described in US Pat. No. 4,476,006. Among these graining methods, the graining method by brush graining and the brush graining and electrolytic graining method are excellent in terms of excellent performance as a lithographic printing plate support and excellent mass productivity. The combined graining method is advantageous,
The brush used in the brush graining process, even if multiple brushes are used, use a certain type of hair material, hair diameter (diameter), and hair cross-sectional shape. Was customary.

However, aluminum supports grained by brush graining using one type of brush or aluminum grained by a multi-graining method combining such brush graining and electrolytic graining methods. The support still has insufficient hydrophilicity, water retention and adhesion. That is, in order to improve the hydrophilicity to a desirable extent, it is necessary to make the roughness of the rough surface shallow and smooth to some extent, but this will reduce the water retention of the support and deteriorate the adhesion to the photosensitive layer. Conversely, when the roughness of the rough surface is deepened, the water retention, that is, the water width is increased, and the adhesion to the photosensitive layer is further improved, but background contamination occurs. In recent years, in the lithographic printing industry, high speed and automation are rapidly progressing, and in the current situation where skilled workers are in short supply, lithographic printing plates that are easy to print even for unskilled people and have higher quality and stable than now That is, a lithographic printing plate having a wide water width and less stains has been long-awaited.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high water retention property so that even if the dampening water is reduced, the shadow portion is not crushed, the stain is hardly generated, and the adhesion to the photosensitive layer is improved. An object of the present invention is to provide a support for a photosensitive lithographic printing plate.

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 surface of an aluminum plate has been formed using at least two types of brushes having different hair diameters.
The present inventors have found that the above object can be achieved by a novel mechanical surface roughening method for roughening, and have accomplished the present invention. The present invention is a method for producing an aluminum support for a lithographic printing plate, comprising a brush graining step of roughening the surface of an aluminum plate with at least two types of brushes having different hair diameters. However, the bra
Except when the disc is a disc brush.

Hereinafter, the method for producing the aluminum support for a lithographic printing plate of the present invention will be described in detail. 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 is:
The composition is not specified, and those of conventionally known and publicly used materials, for example, JIS A 1050, JIS A 1100, JIS
A3103, JIS A3005, etc. can be used as appropriate.
The thickness of the aluminum plate used in the present invention is approximately 0.
It is about 1 mm to 0.6 mm.

First, prior to brush graining an aluminum plate, if necessary, a degreasing treatment for removing rolling oil on the surface, for example, a degreasing treatment with a surfactant, an organic solvent or an alkaline aqueous solution is performed. However, the degreasing treatment may be omitted. Subsequently, brush graining is performed using at least two types of brushes having different bristle diameters while supplying the polishing slurry liquid to the aluminum plate surface. The brush used first in the brush graining is called a first brush, and the brush used last is called a second brush. At the time of the grain, as shown in FIG. 1, roll brushes 2 and 4 sandwiching the aluminum plate 1,
Two support rolls 5, 6 and 7, 8 are arranged respectively. The two support rolls 5, 6 and 7, 8 are arranged such that the shortest distance between their outer surfaces is smaller than the outer diameter of each of the brushes 2 and 4, and the aluminum plate 1 is applied by the brushes 2 and 4. The aluminum plate is conveyed at a constant speed while being pressed and pushed between the two support rolls 5, 6, 7 and 8, and the polishing brush 3 is supplied onto the aluminum plate to rotate the roll brush. It is preferable that the surface be polished.

[0008] The brush used in the present invention has a roll-shaped base portion made of nylon, polypropylene, animal hair, or
A brush material such as a steel wire implanted with a uniform bristle length and a flocking distribution, a brush hair bundle implanted with a small hole in the base, and a channel roll type are preferably used. Among them, a preferable material is nylon, and a preferable hair length after flocking is 10 to 200 mm. The density of flocking when implanting into brush rolls is 1 cm ²
It is preferably 30 to 1000 pieces, more preferably 5 pieces per piece.
The number is 0 to 300. The preferred brush diameter of the brush is 0.57 mm to 1.20 mm, more preferably 0.5 mm for the first brush.
64mm or more and 1.00mm or less, the second brush is 0.10mm
Not less than 0.34 mm, more preferably not less than 0.20 mm and 0.30 mm
It is as follows. If the former is less than 0.57 mm, water retention sufficient to prevent the shadow portion from being crushed when the dampening solution is reduced during printing cannot be obtained. The role of the latter, a thin brush having a bristle diameter of 0.34 mm or less, is to smooth the sharp convex portion of the grain formed by a thick brush having a bristle diameter of 0.57 mm or more, and to prevent the occurrence of background dirt. If the bristle diameter is larger than 0.34 mm, a sufficient stain preventing effect cannot be obtained.

The number of the first brushes used in the present invention may be one or more, but is preferably one or more and ten or less, and more preferably one or more and six or less. The number of the second brushes may be one or more, but is preferably one or more and three or less, and more preferably one or two. In an integrated manufacturing system in which each processing step of the support is performed continuously, it is necessary to perform each processing step in a short time as much as possible. It is desirable to increase the number of brushes. The rotation of the brush roll is then arbitrarily selected, preferably between 200 rpm and 2000 rpm. A support roll having a rubber or metal surface and having a good straightness is used. As shown in FIG. 1, it is preferable that the rotation direction of the brush roll is performed in the forward direction in the transport direction of the aluminum plate. However, when the number of brush rolls is large, some of the brush rolls may be reversed.

A feature of the present invention is that a support having both hydrophilicity, water retention and adhesion can be obtained by roughening with the above-mentioned thick brush and treating with a fine brush. Therefore, the effect of the present invention is that the shadow portion is not crushed when the amount of dampening water is small, so that the water width is wide, the background is hardly stained, and the adhesion to the photosensitive layer is not deteriorated. Moreover, in the present invention, although the mechanism is not clear, the effect of reducing the dot gain at the time of printing was also observed. The polishing slurry liquid used in the present invention is silica sand,
It is preferable that an abrasive having an average particle size of 15 to 35 μ such as alumina powder, volcanic ash, carborundum, and sand is dispersed in water in a range of preferably 10 to 70% by weight.
The support obtained by the method of the present invention is preferably treated so that the center line average roughness (Ra) becomes 0.5 to 1.0 µ (10 µR of stylus).

After brush-graining the aluminum plate as described above, it is preferable that the surface of the aluminum plate is chemically etched. This chemical etching treatment has a function of removing abrasives, aluminum debris, and the like that have cut into the surface of the aluminum plate that has been subjected to the brush graining treatment, and makes the subsequent electrochemical roughening more uniform. Moreover, it can be achieved effectively. Details of such a chemical etching method are described in U.S. Pat. No. 3,834,998. More specifically, it is a method of immersing in a solution capable of dissolving aluminum, more specifically, in an aqueous solution of an acid or a base. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like. Examples of the base include sodium hydroxide, potassium hydroxide, sodium tertiary phosphate, potassium tertiary phosphate, and aluminate. Sodium silicate, sodium metasilicate, sodium carbonate and the like. Among these, it is particularly preferable to use the latter aqueous solution of a base since the etching rate is high. Chemical etching is performed using a 0.05 to 40% by weight aqueous solution of these acids or alkalis.
Generally, the treatment is performed at a liquid temperature of 100C to 100C for 5 to 300 seconds. When the chemical etching is performed using an aqueous solution of a base, a smut is generally formed on the surface of aluminum. In this case, phosphoric acid, nitric acid, sulfuric acid, chromic acid or two or more of these acids are used. It is preferable to perform a so-called desmut treatment, which is a treatment with a mixed acid containing an acid.

Subsequently, if desired, the aluminum surface is electrochemically roughened. As an electrochemical surface roughening method, there is a method of performing alternating current or direct current in a hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used. Hydrochloric acid or nitric acid concentration is 0.01 ~
It is preferably used in the range of 3% by weight, and is preferably 0.05 to 2.
More preferably, it is 5% by weight. In addition, if necessary, a corrosion inhibitor (or stabilizer) such as nitrate, chloride, monoamines, diamines, aldehydes, phosphoric acid, chromic acid, boric acid, and aluminum oxalate may be added to the electrolyte.
A graining agent and the like can be added. The electrolyte may contain an appropriate amount (1 to 10 g / l) of aluminum ions. The temperature of the electrolyte is usually 10 to 60
Processed at ° C. As the alternating current used at this time, any of a rectangular wave, a trapezoidal wave, and a sine wave can be used as long as the positive and negative polarities are alternately exchanged. Phase alternating current can be used.
The current density is 5 to 100 A / dm ² and 10 to 300 A / dm ² .
It is desirable to process for seconds. The smut adhered to the surface of the aluminum plate thus roughened can be removed with 10 to 50% hot sulfuric acid (40 to 60 ° C.) or dilute alkali (such as sodium hydroxide) as necessary. Is preferred. When removed with an alkali, it is subsequently neutralized by immersion in an acid (nitric acid or sulfuric acid) for cleaning.

Further, if desired, anodizing treatment is performed to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte can be used as long as it forms a porous oxide film. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. Anodizing treatment conditions vary depending on the electrolyte used, and thus cannot be specified unconditionally. In general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C., and the current density is 1 to 60 A / d.
It is appropriate that m ² , voltage is 1 to 100 V, and electrolysis time is 10 seconds to 5 minutes. In the sulfuric acid method, the treatment is usually performed with a direct current, but an alternating current can also be used. The concentration of sulfuric acid is used at 5-30%, and 5% at a temperature range of 20-60 ° C.
Electrolyzed for ~ 250 seconds. This electrolyte preferably contains aluminum ions. Further, the current density at this time is preferably 1 to 20 A / dm ² . In the case of the phosphoric acid method, the treatment is performed at a concentration of 5 to 50%, a temperature of 30 to 60 ° C., and a current density of 1 to 15 A / dm ² for 10 to 300 seconds. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. If the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image area of the lithographic printing plate is easily scratched, and the ink adheres to the scratched area during printing. "Scratch dirt" easily occurs.

After the anodic oxidation treatment, the aluminum surface is subjected to a hydrophilic treatment as required. 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 5% by weight, and the immersion temperature is 20 to 90 ° C, preferably 25%.
To 50 ° C., and the immersion time is 0.1 seconds to 20 minutes, preferably 2 seconds to 1 minute. The pH of the solution used for this is adjusted with basic substances such as ammonia, triethylamine and potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid.
It can be used in a pH range of 1 to 12. 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 2
-200 mg / m ² is suitable, preferably 5-100 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 .

On the back side of the support of a photosensitive lithographic printing plate (PS plate) using the support obtained according to the present invention, a coating comprising an organic polymer compound for preventing the photosensitive layer from being damaged when it is overlaid. Layer (hereinafter, this coating layer is referred to as 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 acetal 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. The thickness of the back coat layer is basically sufficient as long as it does not damage the photosensitive layer even without interleaf paper, and is preferably in the range of 0.01 to 8 μm. If the thickness is less than 0.01 μm, scratches on the photosensitive layer cannot be prevented when the PS plates are handled in a stack. If the thickness exceeds 8 μm, during printing, the back coat layer swells due to chemicals used around the printing plate, causing the thickness to fluctuate, changing the printing pressure and deteriorating 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 a suitable solvent,
Or a method of applying and drying an emulsified dispersion liquid, for example, a method of bonding a pre-formed film to an aluminum support with an adhesive or heat and a method of forming a molten film with a melt extruder and bonding the support to the support. Among them, the most preferable method for securing the above-mentioned coating amount is a method of coating and drying the solution. As the solvent used here, an organic solvent described in JP-A-62-251739 may be used alone or as a mixture.

A photosensitive lithographic printing plate is obtained by providing a photosensitive layer of a known photosensitive composition on the thus obtained aluminum plate having a hydrophilic surface. As the photosensitive composition, o-quinonediazide compound as a main component, a positive type, diazonium salt, alkali-soluble diazonium salt, a photopolymerizable compound containing an unsaturated double bond-containing monomer as a main component, and cinnamic acid and dimethyl Negative type photosensitizers such as photocrosslinkable compounds containing a maleimide group are used. Japanese Patent Publication No. 37-17172, 38-6
No. 961, JP-A-56-107246, and JP-A-60-25
No. 4142, JP-B-59-36259, and 59-25
No. 217, JP-A-56-146145, JP-A-62-19
No. 4257, No. 57-147656, No. 58-100
Also, the electrophotographic photosensitive layer described in JP-A Nos. 862 and 57-161863 and the like can be used. Examples of the photopolymerizable compound having the unsaturated double bond-containing monomer as a main component in the above photosensitive material include, for example, U.S. Pat. Nos. 2,760,863 and 3,060,02
A composition comprising an addition-polymerizable unsaturated compound having two or more terminal ethylene groups and a photopolymerization initiator described in JP-A-59-53836 and JP-A-59-53836 can be used. Examples of negative photosensitive materials containing a photocrosslinkable compound containing a dimethylmaleimide group include, for example, JP-A-52-9852
8, EP 0410654, JP-A-3-2888
No. 53 and JP-A-4-25845.

Among these, the o-naphthoquinonediazide compound used as the 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.

A particularly preferred o-naphthoquinonediazide compound is a compound 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 (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 structural 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, for example, modified with glycidyl acrylate, glycidyl methacrylate or the like 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 to 10 meq / g, more preferably 0.2 to 5.0 meq / g. The preferred molecular weight of the copolymer is 10,000 to 100,000. 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 can be used alone or in combination of two or more, and 80% by weight of the total photosensitive composition.
The following addition amount is used. Further, U.S. Pat.
As described in the specification of JP-A No. 9, the combined use of a condensate of a phenol having a C3-8 alkyl group as a substituent and a formaldehyde, such as a t-butylphenol formaldehyde resin and an octylphenol formaldehyde resin, is difficult to obtain. 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-
Endoxy-Δ ⁴ -tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. Examples of phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone,
4 ', 4 "-trihydroxy-triphenylmethane,
4,4 ', 3 ", 4" -tetrahydroxy-3,5
3 ', 5'-tetramethyltriphenylmethane and the like. Further, as the organic acids, JP-A-60-88
942, JP-A-2-96755, and the like, and include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphoric esters, and carboxylic acids. 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,
Examples thereof include 1,4-cyclohexene-2,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, and ascorbic acid. The proportion of the cyclic acid anhydrides, phenols and organic acids in the photosensitive composition is 0.
It is preferably from 0.5 to 15% by weight, more preferably from 0.1 to 5% by weight.
% 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 alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N
-Tetradecyl-N, N-betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and alkylimidazoline 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 0.5 to 15% by weight.
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 temporal stability and give clear print-out images.

As the colorant for the image, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. 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 from 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. In the photosensitive composition,
A surfactant for improving the coating surface quality, for example, a fluorine-based surfactant described in JP-A-62-170950 can be added. A preferable addition amount is 0.001 to 1.0% by weight of the whole photosensitive composition,
More preferably, it is 0.005 to 0.5% by weight.

Next, examples of the photosensitive composition of the negative PS plate include those having a photosensitive layer containing a photosensitive diazo compound, a photopolymerizable photosensitive layer, and a photocrosslinkable photosensitive layer.
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 and A co-condensed diazo compound with an aromatic compound substituted with an alkali-soluble group such as a hydroxyl 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.

Furthermore, 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-mentioned monomer may be copolymerized. In addition, a copolymer obtained by copolymerization of the above-mentioned monomers, for example, modified with glycidyl acrylate, glycidyl methacrylate or the like 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 to 10 meq / g, more preferably 0.2 to 5.0 meq / g. The preferred molecular weight of the copolymer is 10,000 to 100,000. 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% by weight in the solid content of the entire photosensitive composition.
In the range of

In the photosensitive composition, a sensitizing agent (for example, a half ester of a styrene-maleic anhydride copolymer with an alcohol 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, and a dye 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 dye is usually contained in the photosensitive composition in an amount of about 0.5 to 10% by weight, more preferably 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 coating amount of the layer of the photosensitive composition (photosensitive layer) applied on the support varies depending on the application, but is generally 0.3 to 0.4 in terms of the weight after drying.
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 stronger, for example, when used as a printing plate,
A printing plate with 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 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 ratio of silicon oxide SiO _{2 as} a component of silicate to alkali metal oxide M ₂ O (generally [SiO ₂ ] / [M ₂
O]] and the concentration can be adjusted. For example, JP-A-54-6200
No. 4, as disclosed in Japanese Unexamined Patent Application Publication No. 4 (Kokai) No. 4, the molar ratio of SiO ₂ / Na ₂ O is 1.0 to 1.5 (that is, [SiO ₂ ] / [Na ₂ O] is 1.0 to 1.5).
And an aqueous solution of sodium silicate having a content of SiO ₂ of 1 to 4% by weight, or [SiO ₂ ] / [M] of 0.5 as described in JP-B-57-7427. 0.75 (i.e., [SiO _2] / [M ₂ O] is 1.0 to 1.5) a total alkali concentration of SiO ₂ is from 1 to 4% by weight, and present therein At least 20% based on gram atoms of metal
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, whereby 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 molar ratio of SiO ₂ / Na ₂ O in the developer is 1.0 to 1.5 (that is, [SiO ₂ ] /
[Na ₂ O] is 1.0 to 1.5), and the content of SiO ₂ is 1 to
An aqueous solution of 4% by weight of sodium silicate is used, and the molar ratio of SiO ₂ / Na ₂ O is continuously or intermittently 0.5 to 1.5 depending on the throughput of the positive photosensitive lithographic printing plate. (Ie [Si
A method of adding an aqueous solution of sodium silicate (replenisher) in which O ₂ ] / [Na ₂ O] is 0.5 to 1.5) to the developer;
[SiO ₂ ] /
[M] is 0.5 to 0.75 (that is, [SiO ₂ ] / [M ₂ O] is 1.
0 to 1.5), wherein an alkali metal silicate developer having a SiO ₂ concentration of 1 to 4% by weight is used, and [SiO ₂ ] / [M Is 0.25
00.75 (ie, [SiO ₂ ] / [M ₂ O] is 0.5-1.5), and both the developer and the replenisher are grams of total alkali metal present therein. A development method comprising at least 20% potassium based on atoms is preferably used.

When an alkali metal silicate is used as such a replenisher, the replenisher becomes highly active by reducing the molar ratio [SiO ₂ ] / [M ₂ O], and the replenishment amount can be reduced. This is preferable because the running cost and the amount of waste liquid are reduced. 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 as the highly active developer, the molar ratio of SiO ₂ / M ₂ O is a 0.7 to 1.5, S
Concentration of iO ₂ is an aqueous solution of 1.0 to 4.0 wt% of an alkali metal silicate, also replenisher a molar ratio of SiO ₂ / M ₂ O is 0.3 to 1.0 , the concentration of SiO ₂ is 0.5-4.0 wt%
A system which 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 may have various surface active properties as required for the purpose of accelerating or suppressing the developing property, dispersing the developing residue, and enhancing the ink affinity of the printing plate image area. Agents 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, polyoxyethylene alkylamines, triethanolamine fatty acid esters, and trialkylamine oxides, fatty acid salts, abietic acid salts,
Hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, straight-chain alkylbenzenesulfonates, branched-chain alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates, polyoxy Ethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyltaurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfate salts 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 forms 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. The above-mentioned surfactants can be used alone or in combination of two or more, and 0.001 to 10% by weight in a developer.
More preferably, it is added in the range of 0.01 to 5% by weight.

Suitable organic solvents are those having a solubility in water of about 10% by weight or less, and preferably those having a solubility in water of 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 solution. 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, methol, methoxyquinone, resorcin, and 2-methylresorcin; and amine compounds such as phenylenediamine and phenylhydrazine. More 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 added to the developing solution at the time of use at a concentration of 0.0.
It is contained in the range of 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. . Further, unsaturated fatty acids having a double bond in the carbon chain or branched fatty acids may be used. The aromatic carboxylic acid is 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 amount is 0.1 to 10% by weight, more preferably 0.1 to 10% by weight, based on the amount of the developing solution used.
5 to 4% by weight.

The developing solution 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 the chelating power thereof, the hardness of the hard water used and the amount of the hard water. 0.01 to 5% by weight, more preferably 0.01 to 5% by weight
It is in the range of 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 larger than this range, an adverse effect on an image portion such as color omission appears. 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 when used, and are diluted with water when used. 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 starch derivatives. 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 submerged guide roll or the like for processing. 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.

Example 1 A JIS A 1050 aluminum plate having a thickness of 0.24 mm was brush-grayed by a rotating nylon brush shown below while supplying a suspension of water with pumistone having an average particle size of about 21 μm to the aluminum surface. Was processed. The first brush has a hair length of 1.
00mm, hair diameter 0.95mm, flock density 70 / cm ² ,
The second brush has a bristle length of 80 mm, a bristle diameter of 0.295 mm, and a flock density of 6
The number was 70 lines / cm ² . The rotation of each of the brush rolls was 250 rpm. After brush brushing and washing well with water, 25% in 10% sodium hydroxide at 60 ° C.
Etch for 2 seconds, then rinse with running water and then 20%
Washed neutralized with nitric acid and washed with water. V _A = 12.7V
The electrolytic surface roughening treatment was carried out in a 1% aqueous nitric acid solution using a sinusoidal alternating current under the conditions of (1) and ( ^{2) at} an anode charge of 160 coulomb / dm ² . The surface roughness was measured and found to be 0.79 μm ( _Ra display). Subsequently, 1%
After dipping in sodium hydroxide aqueous solution at 40 ° C for 30 seconds, 3
After immersion in a 0% sulfuric acid aqueous solution and desmutting at 60 ° C. for 40 seconds, a current density of 2 A /
The substrate was prepared by anodizing with direct current so that the weight of the oxide film was 1.6 g / m ² at dm ² .

An undercoat liquid having the following composition was applied to the surface of the substrate thus treated, and dried at 80 ° C. for 30 seconds. The coating amount after drying was 30 mg / m ² . Undercoat solution Aminoethylphosphonic acid 0.10 g Phenylphosphonic acid 0.15 g β-alanine 0.10 g Methanol 40 g Pure water 60 g A substrate was thus prepared. Next, the following photosensitive liquid was applied on this substrate, and dried at 110 ° C. for 1 minute to obtain a positive photosensitive lithographic printing plate. The coating amount after drying was 1.7 g / m ² .

[Photosensitive solution] Esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin (described in Example 1 of US Pat. No. 3,635,709) 0.45 g Cresol-formaldehyde novolak resin (meta-para ratio; 6: 4, weight average molecular weight 3,000, number average molecular weight 1,100, containing 0.7% of unreacted cresol) 1.1 g m-cresol-formaldehyde novolak resin (weight average molecular weight) 1,700, number average molecular weight 600, containing 1% of unreacted cresol) 0.3 g poly [N- (P-aminosulfonylphenyl) acrylamide-co-normal butyl acrylate-co-diethylene glycol monomethyl ether methacrylate] (It is described in Japanese Patent Application No. 3-311241, and the molar ratio of each monomer is 40:40:20, weight average molecular weight 40,000, number average molecular weight 20,000) 0.2 g

P-N-octylphenol-formaldehyde resin (described in US Pat. No. 4,123,279) 0.02 g naphthoquinone-1,2-diazide-4-sulfonic acid chloride 0.01 g tetrahydrophthalic anhydride 1 g Benzoic acid 0.02 g 4- [p-N, N-bis (ethoxycarbonylmethyl) aminophenyl] -2,6-bis (trichloromethyl) -S-triazine 0.01 g 4- [PN- (P -Hydroxybenzoyl) aminophenyl] -2,6-bis (trichloromethyl) -S-triazine 0.02 g 2-trichloromethyl-5- (4-hydroxystyryl) -1,3,4-oxadiazole 0.01 g Dye in which the counter anion of Victoria Pure Blue BOH is 1-naphthalenesulfonic acid 0.02 g

Modiper F-200 (fluorinated surfactant manufactured by NOF Corporation, 30% by weight mixed solvent solution of methyl ethyl ketone and methyl isobutyl ketone) 0.06 g Megafac F177 (fluorinated manufactured by Dainippon Ink and Chemicals, Inc.) Surfactant, 20% by weight methyl isobutyl ketone solution) 0.02 g methyl ethyl ketone 15 g 1-methoxy-2-propanol 10 g

Based on the method described in Example 1 of JP-B-61-28986, the photosensitive layer coated in this manner was treated with (methyl methacrylate / ethyl acrylate / sodium acrylate = 68/20 / A mat layer was formed by electrostatic spraying of the aqueous copolymer solution of 12).
The photosensitive lithographic printing plate thus produced is exposed through a transparent positive film through a transparent positive film for 50 seconds from a distance of 1 m using a 3 kw metal halide lamp, and then SiO ₂ / Na _{2 is} used as a developing solution. O molar ratio is 1.74
A 5.26% aqueous solution of sodium silicate (pH = 12.7)
As a rinse liquid, FR-3 manufactured by Fuji Photo Film Co., Ltd.
(1: 7) and processed through an automatic processor Stabilon 900D manufactured by Fuji Photo Film Co., Ltd. After leaving this lithographic printing plate for one day, printing evaluation was performed. The printing machine used was KOR-D manufactured by Heidelberg, the dampening solution used was EU-3 (1: 100) manufactured by Fuji Photo Film Co., Ltd., and the ink used was Mark Five New Black manufactured by Toyo Ink Co., Ltd.

A fountain solution is squeezed on a printing machine to visually observe how the ink in the non-image area is stained. A: excellent B: good
C: Somewhat poor D: Bad. Regarding the clogging of the shadow area, 8
It was determined whether 0% of the halftone dots were open. The degree of clogging is indicated by the following display. A: Fully open B: Almost open
C: Slightly clogged D: Crushed Note that both dirt and shadow areas, that is, favorable printed matter are obtained at B or higher. As a result, the lithographic printing plate using the support produced by the production method of the present invention was less likely to cause background soiling, and did not cause shadow blockage even when the amount of fountain solution was reduced. Good printed matter was obtained even after printing 100,000 sheets. The results are summarized in Table 1. Examples 2 to 6 Three types of first brushes having a thick hair diameter (hair diameter 0.95 mm, 0.
72 mm and 0.57 mm) and two types of thin second brushes (hair diameters of 0.295 mm and 0.21 mm) were used for brush graining in combinations shown in Table 1, respectively. First
Each of the brushes has a bristle length of 100 mm and a flocking density of 70, 120 and 200 / cm ² , respectively. The second brush has a bristle length of 80 mm and a flocking density of 670, respectively.
And 1000 lines / cm ² . Others are Example 1.
The same treatment was performed. Table 1 shows the results. Comparative Examples 1 to 5 Processing was performed in the same manner as in Example 1 except that brush graining was performed using brushes having different hair diameters. Table 1 shows the combinations of the brushes and the results.

[0059]

[Table 1] Table 1 ブ ラ シ Combinations of brushes Surface roughness Ground pollution Shad The first brush of the 部 part The second brush Ra (μ) ── Hair diameter (mm) 0.95 0.72 0.57 0.295 0.21 実 施 Example 1 * * 0.79 BA 2 * * 0.78 BA 3 * * 0.74 BA 4 * * 0.71 BA 5 * * 0.69 A A 6 * * 0.63 A A ──────────────── ────────────────── Comparative Example 1 * 0.82 DA 2 * 0.76 CA 3 * 0.70 CA 4 * 0.43 AC 5 * 0.35 AD ───────────────────────────── *: Indicates the brush used.

In Table 1, for the surface roughness Ra, _a surface roughness meter Surfcom 300B (Tokyo Seimitsu Co., Ltd .;
It is a value measured with a stylus (10 μR). Examples 7 to 9 and Comparative Examples 6 and 7 Brush graining was performed using two or more first brushes or second brushes. Others were processed similarly to Example 1. Table 2 shows the combinations of the brushes and the results.

[0061]

[Table 2] As shown in Tables 1 and 2, the lithographic printing plates using the supports shown in Examples 1 to 9 of the present invention were less susceptible to background soiling than those of Comparative Examples 1 to 7 , and clogging of the shadow portion was generated. No good performance was exhibited.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a specific example of the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Aluminum plate, 2 ... 1st brush roll, 3 ... Polishing slurry liquid supply device 4 ... 2nd brush roll, 5, 6, 7, 8 ... Support roll

Continuation of the front page (56) References JP-A-5-85079 (JP, A) JP-A-48-33911 (JP, A) JP-A-62-27192 (JP, A) U.S. Pat. No. 2,637,929 (US, A)

Claims (2)

(57) [Claims] 1. While supplying a polishing slurry solution containing an abrasive having an average particle size of 15 to 35 μm to the surface of an aluminum plate, each of the flocking densities is 30 to 1000 fibers / cm ^2.
And the first brush having a hair diameter of 0.57 mm or more and a hair diameter of
At least two types including the second brush of 0.34 mm or less
Brush and the final step of the brush graining process
Using the second brush as the brush, 200-2000r
center line flat of aluminum support at brush rotation speed of pm
Roughen the surface so that the average roughness (Ra) is 0.5 to 1.0 μm.
Water retention and hydrophilicity including brush graining process
An improved method of producing an aluminum support for a lithographic printing plate (except when said brush is a disk brush). 2. The method for producing an aluminum support for a lithographic printing plate according to claim 1, further comprising a step of electrolytic surface roughening and a step of anodizing after said brush graining step.