JPH1152556A - Production of photosensitive planograhic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a planographic printing plate which obviates the occurrence of stains at its ends by cutting the ends at the two opposite sides of an aluminum base to shapes having curvilinear surfaces of which the upper face is projected upward. SOLUTION: The sheet-like or coil-like aluminum sheet 30 is cut to a size meeting a desired printing machine by using a slitter device. At this point, the aluminum sheet 30 is so cut as to form the curvilinear surface shape which is formed by bending the upper face at the end of the aluminum sheet 30 in the direction parting from the surface of the upper part and is projected upward. The preferable range of the shear droop height X of the notched part is 30 to 100 μm and the more preferable range is 40 to 80 μm. The preferable range of the area Y of the notched part is 500 to 20,000 μm<2> and the more preferable range is 2000 to 15,000 μm<2> . The front surface and the entire surface of the curvilinear surface of the aluminum base are thereafter subjected to a surface roughening treatment, anodic oxidation treatment and treatment for hydrophilicity impartation and the upper face of the treated base is provided with a photosensitive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate, and more particularly, to a method for producing a photosensitive lithographic printing plate capable of obtaining a lithographic printing plate having no stain on its edges. is there.

[0002]

2. Description of the Related Art A photosensitive lithographic printing plate using an aluminum plate as a support is commercially available and widely used. As a method for producing such a photosensitive lithographic printing plate, generally, various surface treatments such as graining, anodic oxidation, and chemical conversion treatment are applied to a sheet-like or coil-like aluminum plate alone or in an appropriate combination, and then a photosensitive liquid is applied. , Dried and then cut to a desired size. When printing such a photosensitive lithographic printing plate using a printing plate obtained by processing such as image exposure and development, when printing on paper smaller than the size of the printing plate using a normal sheet-fed printing machine There is no problem when the part corresponding to the edge of the printing plate does not become the printing surface as in the above, but when printing continuously on roll paper using a rotary press such as newspaper printing, printing is not necessary. Since the end portion of the plate becomes the printing surface, the ink adhering to the end portion is also printed on paper and becomes stained, thereby significantly impairing the commercial value of the printed matter. As a method of preventing the end portion of the printing plate from being stained, for example, Japanese Patent Publication No. 57-46754 discloses a method in which an angle θ between an end portion of an aluminum support and an aluminum surface is 10 to 45 °. A method for cutting is disclosed, but when 10,000 or more sheets are printed, ink is accumulated at the edges and stains occur. Japanese Patent Application Laid-Open No. 9-52466 discloses a lithographic printing plate characterized in that a corner formed between a surface having a hydrophilic layer of an aluminum support and an end surface is formed of a convex curved surface. However, the entire corners were not subjected to a hydrophilic treatment, and the prevention of contamination was insufficient. Further, if the hydrophilicity is to be applied to the corners, the surface of the hydrophilic layer is cracked when such a shape is formed, and the ink is fixed to the cracked portion, thereby causing stains. In addition, Japanese Patent Publication 62-61
No. 946 discloses a method of desensitizing the end face of an aluminum support, and JP-A-63-256495 discloses a method of preliminarily hydrophilizing the end face of a printing plate of an aluminum support. Although disclosed, it is still inadequate and further improvements were desired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved method for producing a photosensitive lithographic printing plate capable of obtaining a lithographic printing plate free from stains on the edges. .

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide an aluminum support having at least two opposite ends.
After the upper surface is cut into a shape having an upwardly curved surface, the upper surface of the support and the entire surface of the curved surface are subjected to a roughening treatment, an anodic oxidation treatment, and a hydrophilic treatment, and a photosensitive layer is formed on the upper surface of the treated support. This can be achieved by a method for producing a photosensitive lithographic printing plate characterized by providing a lithographic printing plate.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail.
First, a sheet-like or coil-like aluminum plate is
Slit to the size appropriate for the desired printing press. At this time, the aluminum plate is cut so as to have an upwardly convex curved surface shape formed by bending the upper surface of the end portion away from the upper surface. Thereafter, the entire curved surface and the upper surface of the cut aluminum support are degreased and washed by various methods, grained by various methods, and then, if necessary, residues are removed, and anodizing treatment and hydrophilic treatment are performed. Further, a photosensitive solution is applied to the upper surface of the aluminum support and dried. Surprisingly, the use of the photosensitive lithographic printing plate produced by the method for producing a photosensitive lithographic printing plate according to the present invention significantly reduced stains at the edges during printing. This is because, after forming the end of the aluminum support into the above shape, the surface of the support including the entire curved surface is subjected to the anodic oxide film treatment and the hydrophilic film treatment, so that when cutting which causes the adhesion of ink and the adhesion of dirt. Of cracks on the anodic oxide film.

As the support used in the present invention, aluminum and an aluminum-coated composite support are preferable, and 0.1 to 0.5% by weight of iron and 0.03 to 0.3% by weight of silicon.
3% by weight, 0.001 to 0.03% by weight of copper, and titanium
A 1S aluminum plate containing 0.002 to 0.1% by weight is preferred.

[0007] The support is a cutting portion of the slitter device of FIG.
And it cut | disconnects using the cutting blade of FIGS. 2 and 3, and is formed in the shape which curved the edge part to convex shape as shown in FIG. FIG.
FIG. 3 is a sectional view showing a cutting portion of the slitter device. A pair of upper and lower cutting blades 10 and 20 are arranged on the left and right sides of the slitter device. These cutting blades 10 and 20 are made of round blades on a disk, and the upper cutting blades 10a and 10b are
The lower cutting blades 20a and 20b are coaxially supported on the rotating shaft 21. And the upper cutting blade 1
0a and 10b and lower cutting blades 20a and 20b are rotated in opposite directions. The aluminum sheet 30 includes upper cutting blades 10 a and 10 b and lower cutting blade 20.
a and 20b and cut into a predetermined width.

More specifically, the gap between the upper cutting blade 10a and the lower cutting blade 20a and the gap between the upper cutting blade 10b and the lower cutting blade 20b of the slitting device of FIG.
An end having a shape as shown in FIG. 4 is formed by setting the thickness to 30 to 100 μm. FIG. 2 shows the shapes of the upper cutting blade 10a and the lower cutting blade 20a of the present invention. FIG.
FIG. 3 is an enlarged view of a portion A in FIG. 2, showing a tip shape of the upper cutting blade 10a, a tip shape of the lower cutting blade 20a, and a gap between the upper cutting blade and the lower cutting blade. FIG. 4 shows the cross-sectional shape of the aluminum sheet of Example 1 in which the gap between the upper cutting blade and the lower cutting blade was cut by 50 μm using the slitter device of FIG. 1 and the cutting blade of FIG.

The shape of the notch in FIG. 4 is preferably convexly curved, and more preferably a convex curved shape having no bent portion. In the case where a bent portion is provided, ink may adhere to the bent portion and stain may occur. The preferred range of the sagging height (X) in FIG. 4 is 30 to 100 μm, and the more preferred range is 40 to 80 μm. The preferred range of the area of the notch in FIG. 4 (Y) is 500~20000μm ^2, a more preferred range is 2000~15000μm ^2. FIG.
If the sagging height (X) is less than 30 μm, dirt is generated at the end. If the sagging height (X) is larger than 100 μm, the printing durability of the image portion near the edge is reduced.
If the area (Y) of the notch in FIG. 4 is smaller than 500 μm ² , dirt is generated at the end. When the area (Y) of the notch in FIG. 4 is larger than 20000 μm ² , the printing durability of the image portion near the end is reduced.

The upper surface and the entire curved surface of the cut aluminum material are desirably surface-treated for the purpose of increasing water retention and improving adhesion to the photosensitive layer. Alkali, preferably, may be etched by immersing it in an aqueous solution of 1 to 30% by weight of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate or the like at a temperature of 20 to 80 ° C. for 5 to 250 seconds. Aluminum ions may be added to the etching bath in an amount of about one-fifth of alkali. Then, 20 to 30% by weight aqueous nitric acid or sulfuric acid
Immerse at 70 ° C. for 5 to 25 seconds to neutralize and remove smut after alkali etching. For example, as the surface roughening method, generally known brush polishing method, ball polishing method, electrolytic etching, chemical etching, liquid honing, sand blasting and the like and combinations thereof, and preferably, brush polishing method, electrolytic etching, Chemical etching and liquid honing are mentioned, of which the surface roughening method including the use of electrolytic etching is preferred. Further, as described in JP-A-54-63902, a method of performing brush polishing and then electrolytic etching is also preferable.

As the electrolytic bath used in the electrolytic etching, an aqueous solution containing an acid, an alkali or a salt thereof or an aqueous solution containing an organic solvent is used. Electrolytes containing salts are preferred. For brush polishing, it is preferable to use a pamistone-water suspension and a nylon brush, and it is preferable that the average surface roughness is 0.25 to 0.9 μm. The electrolytic solution used for the electrolytic etching treatment is an aqueous solution of hydrochloric acid or nitric acid, and the concentration is preferably used in the range of 0.01 to 3% by weight, and more preferably 0.05 to 2.5% by weight. preferable. In addition, a corrosion inhibitor (or stabilizer) such as nitrate, chloride, monoamines, diamines, aldehydes, phosphoric acid, chromic acid, boric acid, ammonium oxalate, etc., if necessary, A graining agent and the like can be added. Also, an appropriate amount (1 to 1)
0 g / liter) of aluminum ions.

The electrolytic etching process is usually performed at 10 to 60 ° C.
At the temperature of the electrolyte. If the alternating current used at this time is one in which the positive and negative polarities are alternately exchanged,
Any of a rectangular wave, a trapezoidal wave, and a sine wave can be used, and normal commercial AC single-phase and three-phase AC currents can be used. The current density is 5 to 100 A / dm ² ,
It is desirable to process for 10 to 300 seconds. The surface roughness of the aluminum alloy support in the present invention is adjusted by the quantity of electricity, and is set to 0.2 to 0.8 μm.

Further, the upper surface and the curved surface of the roughened aluminum plate are desmutted with an aqueous solution of an acid or an alkali, if necessary. The grained aluminum alloy is removed and etched (preferably 0%) of the smut adhered to the surface with 10 to 50% by weight of hot sulfuric acid (40 to 60 ° C.) or dilute alkali (such as sodium hydroxide). (In the range of 0.01 to 2.0 g / m ² )
Preferably. If the smut has been removed and etched with an alkali, it is subsequently neutralized by immersion in an acid (nitric acid or sulfuric acid) for cleaning. After removing the surface from the smut, an anodic oxide film is provided on the upper surface and the curved surface of the aluminum support. As the anodic oxidation method, a conventionally well-known method can be used, but sulfuric acid is used as the most useful electrolytic solution. Subsequently, phosphoric acid is also a useful electrolyte. Further, Japanese Patent Application Laid-Open No. 55-2840
The mixed acid of sulfuric acid and phosphoric acid disclosed in Japanese Patent Publication No. 0 is also useful.

In the sulfuric acid method, the treatment is usually performed with a direct current, but an alternating current can also be used. Sulfuric acid concentration 5-3
0% by weight, electrolytic treatment in a temperature range of 20 to 60 ° C. for 5 to 250 seconds, and an oxide film of usually 1 g / m ² or more on the surface,
Preferably, an oxide film of 1 to 10 g / m ² is provided.
The electrolyte preferably contains aluminum ions. At this time, the current density is 1 to 20 A /
dm ² is preferred. In the case of the phosphoric acid method, 5 to 50% by weight
At a temperature of 30-60 ° C. for 10-300 seconds at a current density of 1-15 A / dm ² .

Further, if necessary, US Pat.
The silicate (sodium silicate, potassium silicate) treatment described in US Pat. No. 4,066 and US Pat. No. 3,181,461 and the process described in US Pat. No. 2,946,638 are described. Potassium fluoride zirconate treatment, phosphomolybdate treatment described in U.S. Pat. No. 3,201,247, alkyl titanate treatment described in British Patent 1,108,559, German Patent No. 1,
No. 091,433, polyacrylic acid treatment, German Patent 1,134,093 and British Patent No.
1,230,447, polyvinylphosphonic acid treatment described in JP-B-44-6409, and U.S. Pat. No. 3,307,951. Phytic acid treatment, JP-A-58-1
No. 6,893 and JP-A-58-18291, the treatment with a salt of a hydrophilic organic polymer compound with a divalent metal, and the sulfonic acid described in JP-A-59-101651. Having been subjected to a hydrophilic treatment by undercoating of a water-soluble polymer having a group, JP-A-60-6435
Those colored with an acid dye described in JP-A No. 2 are particularly preferable.

As another hydrophilic treatment method, silicate electrodeposition described in US Pat. No. 3,658,662 can be mentioned. Further, after graining treatment and anodic oxidation, sealing treatment is 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.

Further, the aluminum support may be undercoated. Examples of the compound used for the undercoat include carboxymethylcellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, phenylphosphonic acid optionally having a substituent, naphthylphosphonic acid, and alkylphosphonic acid. Acids, organic phosphonic acids such as glycerophosphonic acid, methylene diphosphonic acid and ethylene diphosphonic acid, organic phosphoric acids such as phenylphosphoric acid, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid which may have a substituent, substituents Having organic groups such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydroxyl groups such as triethanolamine hydrochloride. Water-soluble polymer having hydrochloride Min, a sulfonic acid group as described in JP-A-59-101651, and JP 60-64
Acid dyes and the like described in JP-A-352 are preferably used. This undercoat layer can be provided by dissolving the above compound in water, methanol, ethanol, methyl ethyl ketone, or the like, or a mixed solvent thereof, coating the support on a support, and drying. Further, a yellow dye can be added for improving the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the undercoat layer after drying is suitably from ² to 200 mg / m ² , and preferably from 5 to 100 mg / m ² .

The photosensitive layer of the photosensitive lithographic printing plate to which the present invention can be applied includes various photosensitive layers, such as a negative photosensitive composition comprising a diazo resin and a hydrophobic resin, and a positive photosensitive composition comprising an o-quinonediazide compound and a novolak resin. -Type photosensitive composition, an addition-polymerizable unsaturated monomer, a photopolymerization initiator and a photopolymerizable composition comprising an organic polymer compound as a binder or having a -CH = CH-CO- bond in the molecule, and photocrosslinking Examples thereof include those provided with a photosensitive resin that causes a reaction. A typical negative photosensitive composition includes a composition containing a diazo resin and a binder. The diazo resin is a diazo resin represented by a condensate of an aromatic diazonium salt and a compound containing an active carbonyl group, for example, formaldehyde. As the diazo resin, for example,
an organic solvent-soluble inorganic salt of a diazo resin which is a reaction product of a condensate of p-diazodiphenylamines with an aldehyde such as formaldehyde or acetaldehyde and hexafluorophosphate or tetrafluoroborate;
Sulfonates with the condensate as described in JP-A-7-1167, for example, p-toluenesulfonic acid or a salt thereof, propylnaphthalenesulfonic acid or a salt thereof, butylnaphthalenesulfonic acid or a salt thereof, dodecylbenzenesulfone Acid or a salt thereof, 2-hydroxy-
An organic solvent-soluble diazo resin organic salt which is a reaction product with 4-methoxybenzophenone-5-sulfonic acid or a salt thereof is exemplified. In particular, a high molecular weight diazo compound containing at least 20 mol% of a hexamer or more described in JP-A-59-78340 is preferable.

Also, 3-methoxy-4-diazo-diphenylamine as disclosed in JP-A-58-27141 is condensed with 4,4'-bis-methoxy-methyl-diphenyl ether to form a mesitylene sulfonate. What is done is also suitable. Further, a copolymer containing at least one of a carboxyl group, a sulfonic acid group, a sulfinic acid group, an oxygen acid group of phosphorus, and a hydroxyl group, and a diazonium compound, preferably an aromatic diazonium compound, as structural units. Condensates are preferred. Preferred binders have an acid content of 0.1 to 3.0 m.
eq / g, preferably 0.2 to 2.0 meq / g, which is a substantially water-insoluble (ie, insoluble in a neutral or acidic aqueous solution) and film-forming organic polymer compound, Those which can be dissolved or swelled in an aqueous alkali-based developer and are photo-cured in the presence of the photosensitive diazo resin to make them insoluble or non-swellable in the developer are preferred. When the acid content is less than 0.1 meq / g, development is difficult, and when the acid content exceeds 3.0 meq / g, the image intensity during development is significantly reduced.

Particularly preferred binders are copolymers containing acrylic acid, methacrylic acid, crotonic acid or maleic acid as essential components, for example, 2-hydroxyethyl as described in JP-A-50-118802. Multi-component copolymers of acrylate or 2-hydroxyethyl methacrylate, acrylonitrile or methacrylonitrile, acrylic acid or methacrylic acid and, if necessary, other copolymerizable monomers, JP-A-53-12090
Acrylic or methacrylic acid, acrylic acid, in which the terminal is a hydroxy group and esterified with a group containing a dicarboxylic acid ester residue as described in JP-A-3
Or a multi-component copolymer of methacrylic acid and, if necessary, another copolymerizable monomer, JP-A-54-98614.
No. 4,086,098, and a monomer having an aromatic hydroxyl group at the terminal thereof (for example, N- (4-hydroxyphenyl) methacrylamide, etc.), acrylic acid or methacrylic acid, and other copolymerizable if necessary. And a multi-component copolymer comprising an alkyl acrylate, acrylonitrile or methacrylonitrile and an unsaturated carboxylic acid as described in JP-A-56-4144. In addition, acidic polyvinyl alcohol derivatives and acidic cellulose derivatives are also useful. Japanese Patent Publication No. 54-19773, in which polyvinyl acetal or polyurethane is alkali-soluble,
Nos. -94747, 60-182437 and 62-5
The binders described in Nos. 8242 and 62-123453 are also useful. Further, a polymer having a maleimide group in the side chain and capable of photoreticulation described in JP-B-5-2227 is also useful.

The content of the diazo resin and the binder in the photosensitive layer of the photosensitive lithographic printing plate is 3 to 30% by weight of the diazo resin and the binder is 97 to
70% by weight is suitable. When the content of the diazo resin is small, the sensitivity is high, but when the content is lower than 3% by weight, it is insufficient for photocuring the binder, and the photocured film swells with the developing solution during development, and the film becomes weak. Conversely, if the content of the diazo resin is more than 30% by weight, the sensitivity is lowered and practical difficulties arise. Therefore, a more preferable range is 5 to 25% by weight of the diazo resin and 95 to 75% by weight of the binder.

Examples of the photosensitive compound of the positive photosensitive composition include o-quinonediazide compounds, and representative examples thereof include o-naphthoquinonediazide compounds. o
-As a naphthoquinonediazide compound, JP-B-43-
Preferred is an ester of 1,2-diazonaphthoquinonesulfonic acid chloride and pyrogallol-acetone resin described in JP-A-28403. Other suitable orthoquinonediazide compounds include U.S. Pat.
There are esters of 1,2-diazonaphthoquinone-5-sulfonic acid chloride and phenol-formaldehyde resin described in 3,046,120 and 3,188,210. 96163, JP-A-2-96165, and JP-A-2-96661, 1,2-diazonaphthoquinone-4-
There are esters of sulfonic chloride and phenol-formaldehyde resin. Other useful o-naphthoquinonediazide compounds have been reported in numerous patents,
There are known ones. For example,
No.-5303, No.48-63802, No.48-638
No. 03, No. 48-96575, No. 49-38701
No. 48-13354, JP-B-37-18015
No. 41-11222, No. 45-9610, No. 4
No. 9-17481, U.S. Pat. No. 2,797,213,
No. 3,454,400, No. 3,544,323, No. 3,
No. 573,917, No. 3,674,495, No. 3,785,
No. 825, British Patent Nos. 1,227,602 and 1,251,
No. 345, No. 1,267,005, No. 1,329,888
No. 1,330,932, German Patent No. 854,890, and the like.

As the photosensitive compound which acts positively without using an o-naphthoquinonediazide compound, for example, a polymer compound having an orthonitrocarbinol ester group described in JP-B-56-2696 is also used in the present invention. can do. Further, a compound generating an acid by photolysis and a -COC group or-dissociated by the acid.
Combinations with compounds having a CO-Si group can also be used in the present invention.

For example, a combination of a compound capable of generating an acid by photolysis with an acetal or an O, N-acetal compound (JP-A-48-90303), a combination with an orthoester or amide acetal compound (JP-A-51-120)
714), a combination with a polymer having an acetal or ketal group in the main chain (JP-A-53-133429),
Combination with enol ether compound (JP-A-55-12
No. 995), a combination with an N-acylimino carbon compound (JP-A-55-126236), a combination with a polymer having an orthoester group in the main chain (JP-A-56-1).
No. 7345), a combination with a silyl ester compound (JP-A-60-10247) and a combination with a silyl ether compound (JP-A-60-37549, JP-A-60-12).
No. 1446).

The photosensitive material used in the photosensitive composition of the present invention includes polyesters, polyamides and polycarbonates containing -CH = CH-CO- as a photosensitive group in the polymer main chain or side chain. A polymer containing such a photosensitive polymer as a main component is also suitable. For example, JP-A-55-40
Photosensitive polyesters obtained by condensation of phenylenediethyl acrylate with hydrogenated bisphenol A and triethylene glycol as described in US Pat. No. 2,956,878, as described in US Pat. Examples thereof include (2-propenylidene) malonic acid compounds such as cinnamylidenemalonic acid and photosensitive polyesters derived from bifunctional glycols.

Further, as the photosensitive substance used in the photosensitive composition of the present invention, an aromatic azide compound in which an azide group is bonded to an aromatic ring directly or via a carbonyl group or a sulfonyl group is also exemplified. For example, U.S. Pat.
Polyazide styrene, polyvinyl-p-azidobenzoate, polyvinyl-p-azidobenzal described in JP-A-096,311; and azidoarylsulfanyl chlorides described in JP-B-45-9613 and unsaturated hydrocarbons. Reaction product with polymer, and JP-B-43-21
And polymers having a sulfonyl azide or a carbonyl azide, as described in JP-A Nos. 067, 44-229, 44-22954, and 45-24915. Furthermore, as the photosensitive substance used in the photosensitive composition of the present invention, a photopolymerizable composition comprising an addition-polymerizable unsaturated compound can also be used. The present invention can also be applied to a photosensitive composition used for an electrophotographic printing plate. For example, JP-A-55-161250
And a photosensitive composition comprising an electron-donating compound, a phthalocyanine-based pigment, and a phenol resin used for a printing plate using electrophotography described in (1).

The photosensitive composition is dissolved in the above-mentioned coating solvent, and is preferably applied to an aluminum support having a hydrophilic surface in a dry coating weight of 0.3 to 5.0 g / m ² , preferably 0.5 to 5.0 g / m ^2. 3.
It is applied to a concentration of 5 g / m ² and dried to obtain a photosensitive lithographic printing plate. The solid content concentration of the photosensitive composition at the time of coating is suitably 1.0 to 50% by weight, preferably
2.0-30% by weight is suitable. As a method for applying the photosensitive composition on the support, a conventionally known method, for example, a method such as roll coating, bar coating, spray coating, curtain coating, and spin coating can be used. The applied photosensitive composition solution is 50
Drying at ~ 150 ° C is preferred. As a drying method, after preliminarily drying at a lower temperature, drying may be performed at a high temperature or directly at a high temperature.

It is preferable to provide a mat layer composed of protrusions provided independently of each other on the photosensitive layer. The purpose of the mat layer is to improve the vacuum adhesion between the negative image film and the photosensitive lithographic printing plate in contact exposure, thereby shortening the vacuuming time and preventing the collapse of minute dots during exposure due to poor adhesion. That is. As a method for applying the mat layer, a method for thermally fusing powdered solid powder described in JP-A-55-12974 and a polymer-containing water described in JP-A-58-182636 are used. And drying. Any of these methods can be used. The mat layer is desirably composed of a substance which is dissolved in an aqueous developer substantially free of an organic solvent or which can be removed thereby. A photosensitive lithographic printing plate having a photosensitive composition layer coated and dried on an aluminum plate having an upper surface and a curved surface roughened and subjected to anodizing treatment and hydrophilic treatment is subjected to an aqueous alkali developing after image exposure. By developing with a liquid, a relief image is obtained. Light sources suitable for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, ultraviolet rays, laser beams and the like.

As an aqueous alkaline solution-based developer used for developing a negative photosensitive lithographic printing plate, JP-A-51-774 can be used.
No. 01, No. 51-80228, No. 53-44202 and Nos. 55-52054, each having a pH of 8 to 13 and containing 75% by weight or more of water. Are preferred. If necessary, an organic solvent (benzyl alcohol, ethylene glycol monophenyl ether) having a solubility in water of 10% by weight or less at room temperature, an alkali agent (triethanolamine, diethanolamine, monoethanolamine, sodium phosphate, sodium carbonate), anionic surface activity Agents (aromatic sulfonate, dialkyl sulfosuccinate, alkyl naphthalene sulfonate, fatty acid salt, alkyl sulfate salt),
Nonionic surfactants (polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether,
A polyoxyethylene polyoxypropylene block polymer), a stain inhibitor (sodium sulfite, sodium salt of sulfopyrazolone) and a water softener (tetrasodium ethylenediaminetetraacetate, trisodium nitrotriacetate) can be added. However, if organic solvents are contained, toxicity during work, hygiene problems such as odor, fire,
Since there is a problem of safety such as gas explosion, a problem of workability such as generation of bubbles, a problem of pollution by waste liquid, a problem of cost, and the like, those containing substantially no organic solvent are more preferable. Examples of such an aqueous alkaline developer containing substantially no organic solvent include, for example, JP-A-59-84241, JP-A-57-192952 and JP-A-62-22633.
JP-A No. 6-264, etc., a developer composition used when developing a positive-working lithographic printing plate after image exposure to light can be used.

The photosensitive lithographic printing plate of the present invention is disclosed in
-8002, 55-115045 and 59-58
The plate-making process may be performed by the method described in each of the publications of No. 431. That is, after the development processing, it may be subjected to a desensitization treatment after washing with water, a desensitization treatment as it is, a treatment with an aqueous solution containing an acid, or a treatment with an aqueous solution containing an acid, followed by a desensitization treatment. Further, in the development process of this type of photosensitive lithographic printing plate, the alkali aqueous solution is consumed depending on the processing amount, and the alkali concentration is reduced. The performance is reduced.
The processing capacity may be restored by using a replenisher as described in JP-A-2004-2004. In this case, US Pat. No. 4,882,2
It is preferable to replenish by the method described in No. 46. The plate making process described above is disclosed in Japanese Patent Application Laid-Open No. 2-705.
It is preferably carried out using an automatic developing machine as described in JP-A Nos. 4 and 2-32357. Examples of the desensitized gum that is optionally applied in the final step of the plate making process include JP-B Nos. 62-16834, 62-25118, 63-52600, JP-A-62-2595, and JP-A-62-7595.
Those described in JP-A-11693 and JP-A-62-83194 are preferable. After the processing with the developing solution, if necessary, unnecessary portions of the image area can be erased with a commercially available negative erasing solution or rubbed with a stone stick.

The developer used for developing the positive photosensitive lithographic printing plate is preferably an alkaline aqueous solution substantially free of an organic solvent, and specifically includes sodium silicate, potassium silicate, sodium hydroxide, and hydroxide. Potassium, lithium hydroxide, sodium phosphate tribasic, sodium phosphate dibasic, ammonium phosphate tribasic, ammonium phosphate dibasic, sodium metasilicate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, aqueous ammonia Aqueous solutions such as are suitable and their concentration is 0.1.
-10% by weight, preferably 0.5-5% by weight. Among these, potassium silicate, lithium silicate, a developer containing an alkali silicate such as sodium silicate is preferable because stains during printing hardly occur,
When the composition of the alkali silicate is [SiO ₂ ] / [M] = 0.
5 to 2.5 (where [SiO ₂ ] and [M] indicate the molar concentration of SiO _{2 and} the molar concentration of the total alkali metal, respectively) and contain 0.8 to 8% by weight of SiO ₂ . Developing solution is preferably used. In addition, water-soluble sulfites such as sodium sulfite, potassium sulfite, and magnesium sulfite, resorcin, methylresorcin, hydroquinone, thiosalicylic acid, and the like can be added to the developer. The content of these compounds in the developer is preferably 0.002 to 4% by weight, and more preferably 0.01 to 1% by weight.

Further, in a developer, JP-A-50-51324 is used.
JP-A-59-84241 and JP-A-59-84241 and JP-A-59-75255, JP-A-60-111246 and JP-A-60-213943. Or at least one of the nonionic surfactants described in JP-A-55-95946 and JP-A-56-142528. Is preferably used because it can increase the wettability to the photosensitive composition and the development stability (development latitude). The addition amount of such a surfactant is preferably 0.001 to 2% by weight, and particularly preferably 0.003 to 0.5% by weight. Further, as the alkali metal of the alkali silicate, it is preferable that potassium is contained in an amount of 20 mol% or more in all the alkali metals, since the generation of insolubles in the developer is small, and more preferably 9%.
0 mol% or more, most preferably 100 mol% of potassium
Is the case.

Further, the developing solution used in the present invention may contain a small amount of an organic solvent such as an alcohol or the like and JP-A-58-190952.
Chelating agent described in Japanese Patent Publication No. 1-301
An antifoaming agent such as a metal salt or an organic silane compound described in JP-A-39 can be added. The photosensitive lithographic printing plate of the present invention is disclosed in JP-A-54-8002 and JP-A-55-8002.
Needless to say, the plate-making process may be performed by the methods described in JP-A-115045 and JP-A-59-58431. That is, after the development processing, it may be subjected to a desensitization treatment after washing with water, a desensitization treatment as it is, a treatment with an aqueous solution containing an acid, or a desensitization treatment after treating with an aqueous solution containing an acid. Furthermore, in the development process of this type of photosensitive lithographic printing plate, the alkali aqueous solution is consumed depending on the processing amount, and the alkali concentration is reduced, or the alkali concentration is reduced by air due to long-time operation of the automatic developing solution. The processing capacity is reduced.
Processing capacity may be restored using a replenisher as described in US Pat. In this case, U.S. Pat. No. 4,882,24
It is preferable to replenish by the method described in No. 6.
Further, the plate making process as described above is disclosed in Japanese Patent Application Laid-Open No. 2-7054.
And an automatic developing machine as described in JP-A-2-32357.

In the case where the photosensitive lithographic printing plate of the present invention is subjected to image exposure, development, washing or rinsing, and then unnecessary image portions are erased, it is described in JP-B-2-1293. It is preferable to use such an erasing liquid. Examples of the desensitized gum which is applied as required in the final step of the plate making process include JP-B-62-16834, JP-B-62-25118, JP-B-63-52600 and JP-A-6-52600.
Nos. 2-7595, 62-11693 and 62-83
What is described in each gazette of No. 194 is preferable. Furthermore, when the photosensitive lithographic printing plate of the present invention is subjected to image exposure, development, washing or rinsing, erasing if desired, and burning after washing with water, before burning, Japanese Patent Publication No. 61-2518 is used. And JP-A-55-28062, JP-A-62-31859, and JP-A-61-159655.

Synthesis Example 1 4-diazodiphenylamine sulfate (purity 99.5%) 2
9.4 g at 25 ° C. were slowly added to 70 ml of 96% sulfuric acid and stirred for 20 minutes. 3.26 g of paraformaldehyde (purity: 92%) was gradually added over about 10 minutes, and the mixture was stirred at 30 ° C. for 4 hours to allow a condensation reaction to proceed. The condensation molar ratio between the diazo compound and formaldehyde is 1: 1. While stirring the reaction product,
The mixture was poured into 2 liters of ice water and treated with a cold concentrated aqueous solution in which 130 g of sodium chloride was dissolved. The precipitate is filtered off with suction.
The recovered, partially dried solid is dissolved in 1 liter of water, filtered, cooled with ice and washed with potassium hexafluorophosphate 2
The solution was treated with an aqueous solution in which 3 g was dissolved. The precipitate was collected by filtration and air-dried to obtain 30.3 g of the high molecular weight diazo compound (1).
I got The obtained diazo compound (1) was coupled with 1-phenyl-3-methyl-5-pyrazolone in methyl cellosolve to obtain a dye. The weight average molecular weight of the dye (using a low angle light scattering photometer) is 16,500.
Which corresponded to about 45-mers. The molecular weight distribution of this dye was measured by gel permeation chromatography (GPC).
0 mol% was contained.

[0036]

Next, the present invention will be described by way of examples. Example 1 99.5% by weight aluminum containing 0.01% by weight of copper, 0.03% by weight of titanium, 0.3% by weight of iron and 0.1% by weight of silicon, 0.3 mm in thickness , 800mm wide coiled JI
The gap between the upper cutting blade and the lower cutting blade (D) is 50 μm using the slitter device of FIG. 1 and the cutting blade of FIG.
And the amount of engagement between the upper and lower cutting blades (S)
Was set to 300 μm, and slits were continuously formed in a shape such that the cutting sag height was 60 μm as shown in FIG. The area (Y) of the cutout of the cut plate is 400
It was 0 μm ² . The upper surface and the entire curved surface of the cut aluminum support were roughened, anodized, and hydrophilized as described below. First, the upper surface and the entire curved surface of the aluminum support were sanded using a 400-mesh 20% by weight aqueous suspension of Pamistone (manufactured by Kyoritsu Ceramics) and a rotating nylon brush (6,10-nylon). After sharpening, it was washed well with water. This is 15
Weight of sodium hydroxide solution (containing 4.5% by weight of aluminum) to dissolve 5 g / m ^{2 of} aluminum.
And then washed with running water. Further, the mixture was neutralized with 1% by weight of nitric acid, and then, in an aqueous solution of 0.7% by weight of nitric acid (containing 0.5% by weight of aluminum), the voltage at the time of anode was set at 10%.
Using a rectangular wave alternating waveform voltage of 5 volts and a cathode voltage of 9.3 volts (current ratio r = 0.90, current waveform described in Examples of Japanese Patent Publication No. 58-5796), 160 coulombs / dm ² The electrolytic surface roughening treatment was performed with the amount of electricity at the time of anode. After washing with water, the substrate was immersed in a 10% by weight aqueous solution of sodium hydroxide at 35 ° C., etched so that the amount of aluminum dissolved was 1 g / m ² , and then washed with water. Next, at 50 ° C. 30% by weight
Immersed in an aqueous sulfuric acid solution, desmutted, and washed with water.

Further, a porous anodic oxide film was formed on the upper surface and the entire curved surface of the aluminum support using a direct current in a 20% by weight aqueous sulfuric acid solution (containing 0.8% by weight of aluminum) at 35 ° C. . That is, the current density 13
The electrolysis was performed at A / dm ² , and the anodic oxide film weight was adjusted to 1.2 g / m ² by adjusting the electrolysis time. To prepare a negative photosensitive lithographic printing plate using a diazo resin and a binder, the support was washed with water, immersed in a 3% by weight aqueous solution of sodium silicate at 70 ° C. for 30 seconds, washed with water and dried. The aluminum support obtained as described above is Macbeth RD92
The reflection density measured with a 0 reflection densitometer was 0.30, and the center line average roughness was 0.58 μm. Next, a methyl methacrylate / ethyl acrylate / 2-acrylamide-2-methylpropane sodium sulfonate copolymer (average molecular weight: about 60,000) (molar ratio: 50/30/20) was added to the support.
A 1.0% by weight aqueous solution was applied by a roll coater so that the applied amount after drying was 0.05 g / m ² . Further, the following photosensitive solution-1 was applied using a bar coater,
For 45 seconds. The dry coating amount was 2.0 g / m ² .

Photosensitive solution-1 Diazo resin of Synthesis Example 1 0.50 g Binder-1 5.00 g Stylite HS-2 (manufactured by Daido Kogyo Co., Ltd.) 0.10 g Victoria Pureable-BOH 0.15 g Tricresyl phosphate 0 .50 g dipicolinic acid 0.20 g FC-430 (surfactant manufactured by 3M) 0.05 g solvent 1-methoxy-2-propanol 25.00 g methyl lactate 12.00 g methanol 30.00 g methyl ethyl ketone 30.00 g water 3.00 g

Binder-1 is 2-hydroxyethyl methacrylate / acrylonitrile / methyl methacrylate / methacrylic acid copolymer (weight ratio 50/20/26 /
4. A water-insoluble, alkali-water-soluble film-forming polymer having an average molecular weight of 75,000 and an acid content of 0.4 meq / g). Stylite HS-2 (manufactured by Daido Kogyo Co., Ltd.) is a polymer compound having higher oil sensitivity than a binder, and styrene / mono-4-methyl-2-pentyl maleate = 50/50 (molar ratio). )), And had an average molecular weight of about 100,000.

One week later, the cut sheet-shaped photosensitive lithographic printing plate was image-exposed and DN-3C (alkaline aqueous solution manufactured by Fuji Photo Film Co., Ltd.) using 800H (an automatic developing machine manufactured by Fuji Photo Film Co., Ltd.). (Development solution) was developed with a solution diluted 1: 1 with water, and immediately a solution prepared by diluting FN-2 (a gum solution manufactured by Fuji Photo Film Co., Ltd.) 1: 1 with water was applied and dried. The printing plate was printed 100,000 the following day on a rotary offset press using newspaper ink of Sakata Ink Co., Ltd. and Toyo Alky dampening water of Toyo Ink Co., Ltd.
20,000 sheets were printed at a speed of sheets / hour. No stain occurred on the printing paper surface corresponding to the edge of the printing plate.

Examples 2 to 7 In the same manner as in Example 1, a coiled aluminum support having a thickness of 0.3 mm and a width of 800 mm was formed to a width of 796 mm by using the slitter apparatus of FIG. 1 and the cutting blade of FIG. And changing the gap (D) between the upper cutting blade and the lower cutting blade between 30 and 100 μm,
By changing the biting amount (S) between 200 and 800 μm, the cutting sag height as shown in FIG.
m and slits were continuously formed. Table 1
The numbers and conditions of the examples are shown in the middle, and the sag height (X) and the area of the notch (Y) at the curved portions of these plates are shown. Thereafter, as in Example 1, the upper surface of the support and the entire curved surface were subjected to surface roughening, anodizing treatment and hydrophilic treatment. Further, a photosensitive layer was applied, and plate making and printing were performed in the same manner as in Example 1. In any case, no stain was generated on the printing paper surface corresponding to the edge.

[0042]

Table 1 Example 2 3 4 5 6 7 Clearance between blades (D) μm 30 70 100 50 50 50 Biting amount (S) μm 300 300 300 200 500 800 Dropping height (X) μm 30 70 100 60 60 60 Notch area (Y) μm ² 600 8000 18000 3000 5000 6000 Anodic oxide film amount g / m ² 1.2 1.2 1.2 1.2 1.2 1.2

Comparative Example 1 An aluminum support was slit continuously with the gap between the conventional upper cutting blade and lower cutting blade and the bite amount (0 μm and 300 μm) set. The end shape was almost right angle. Thereafter, a roughening treatment, an anodic oxidation treatment, and a hydrophilic treatment were performed in the same manner as in Example 1, and the photosensitive layer was coated, exposed, developed, and printed in the same manner as in Example 1. Dark linear stains occurred on the printing paper surface corresponding to the edge of the printing plate of Comparative Example 1.

[0044]

As is clear from the above embodiments, in the printing plate manufactured by the method for manufacturing a photosensitive lithographic printing plate of the present invention, no stain is generated on the printing paper surface corresponding to the edge.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cutting unit of a slitter device.

FIG. 2 shows a sectional view of a slitter device cutting section.

FIG. 3 is an enlarged view of a portion A in FIG. 2;

FIG. 4 shows an end shape of the first embodiment.

[Explanation of symbols]

 10a, 10b Upper cutting blade 11 Rotating shaft 20 (20a, 20b) Lower cutting blade 21 Rotating shaft 30 Aluminum sheet

Claims (1)

[Claims] After cutting at least two opposite ends of an aluminum support into a shape having a curved surface whose upper surface is convex upward, a roughening treatment is performed on the upper surface of the support and the entire surface of the curved surface, A method for producing a photosensitive lithographic printing plate, comprising performing an anodizing treatment and a hydrophilizing treatment and providing a photosensitive layer on an upper surface of the treated support.