JPH04176690A - Production of support for planographic printing plate - Google Patents

Abstract

PURPOSE:To enhance the strength and corrosion resistance of a non-image part by roughening the surface of an aluminum plate by anodic oxidation so that the amount of an anodic oxidation film becomes 2g/m<2> or more and applying sealing treatment to the roughened surface to reduce the surface area of the oxidation film to 40-95%. CONSTITUTION:The surface of an aluminum plate is subjected to degreasing treatment for removing the rolling oil on the surface thereof and subsequently roughened. The treated surface is continuously subjected to anodic oxidation treatment in an electrolytic solution containing 5-20wt.% of sulfuric acid and 3-15wt.% of an aluminum ion under such a condition that temp. 25-50 deg.C and DC current density is 5-20A/dm<2>. The amount of the anodic oxidation film is pref. 2-5g/m<2>. Next, the porous oxidation film is exposed to a steam atmosphere or immersed in hot water to be subjected to sealing treatment. As the standard of sealing, a sealing rate is set to 40-95%. Thereafter, hydrophilic treatment and/or hydrophilic undercoat treatment are applied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a support for a lithographic printing plate, and particularly to a method for producing a rough aluminum plate for a lithographic printing plate.

(Prior art) - Photosensitive lithographic printing plates (so-called PS plates), in which a photosensitive composition is coated in a thin layer on aluminum, are produced using mechanical methods such as the brush grain method or pole grain method. The surface is roughened by an electrochemical method such as the electrolytic grain method or a combination of both methods to give the surface a satin finish, then etched with an aqueous solution of acid or alkali, and then anodized. After that, if desired, a hydrophilic treatment is performed, and a photosensitive layer is provided thereon.

This PS plate is usually subjected to image exposure, development, correction, and gumming processes to form a lithographic printing plate, which is then mounted on a printing machine and printed.

Among the various performances of a lithographic printing plate, the strength of the non-image area improves with the thickness of the oxide film.

However, when the amount of oxide film is increased, positive-working lithographic printing plates suffer from the following problems: (1) dyes and polymer binders in the photosensitive layer tend to remain in non-image areas after development, (2) reproducibility of highlighted areas deteriorates, etc. There was a drawback. In addition, even with negative planographic printing plates, (1) dyes and polymeric binders in the photosensitive layer are irreversibly adsorbed onto the support surface over time, causing stains; (2) poor reproducibility of halftone dots in some shadow areas; There were drawbacks such as:

Furthermore, the corrosion resistance of the non-image area against acids or alkalis is improved by sealing the oxide film.

There are several methods for sealing, but for example, as described in U.S. Pat. No. 3,181,461, an anodized aluminum support is immersed in an aqueous solution of an alkali metal silicate. Method, U.S. Patent No. 3.440.
A method of immersion treatment in an aqueous alkali metal salt solution of fluorozirconic acid as described in US Pat. No. 4,153,461 and US Pat. No. 4,689,27.
There are methods such as treatment with polyvinylphosphonic acid as described in No. 2, but PS plates manufactured by these methods do not stain non-image areas and do not cause "background stains" on printed matter. A lithographic printing plate is obtained, but on the other hand, the printing durability of the printing plate is significantly reduced compared to a case without the above-mentioned treatment.

Furthermore, Japanese Patent Application Laid-Open No. 1141/1983 describes a method of treating with water vapor, and it is said that this method does not reduce the printing durability of the printing plate. However, even with this method, if the sealing reaction progresses too much, the positive planographic printing plate will
After development with a developer containing silicate as a main component, the hydrophilicity of the non-image area decreases, and the printing durability decreases, and in negative planographic printing plates, the hydrophilicity of the non-image area decreases. There were disadvantages in that printed matter was more likely to have background stains and its printing durability was reduced.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing a lithographic printing plate support suitable for producing a lithographic printing plate with excellent strength and corrosion resistance in non-image areas. .

(Means for Solving the Problems) The present inventors have made extensive studies to achieve the above object, and as a result, have come up with the present invention. In the present invention, the surface of an aluminum plate is roughened, and the amount of anodized film is 2 g.
/ m' or more, and then sealing with hot water or steam to reduce the surface area of the oxide film to 40 ~
This is a method for producing a support for a lithographic printing plate, which is characterized in that it is reduced by 95% and then subjected to a hydrophilic treatment and/or a hydrophilic undercoating treatment.

The present invention will be explained step by step below.

(Aluminum Plate) The aluminum plate used in the present invention is a plate-shaped body of pure atubenium or an aluminum alloy whose main component is aluminum and contains a heavy amount of different atoms.

Such foreign atoms include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of these foreign atoms is generally 10% by weight or less. Aluminum suitable for the support of the present invention is pure atubenium, but since it is difficult to produce completely pure aluminum due to refining technology, it is preferable to use aluminum that does not contain foreign atoms as much as possible. As described above, the aluminum plate applied to the present invention is not limited in its composition, and can be made of conventionally known and publicly used materials (for example, JISA105
0, JIS Al100, JISA1200, JIS
A3103, JISA3003, JIS A30
05 etc.) can be used as appropriate. The thickness of the aluminum plate used in the present invention is 0.1111[11-0,
Approximately 5 mm is appropriate.

(Surface Roughening Treatment) Prior to anodizing, the surface of the aluminum plate is subjected to degreasing treatment using a surfactant or alkaline aqueous solution to remove rolling oil on the surface, if desired, and then roughened. be converted into

Surface roughening methods include a method of mechanically roughening the surface, a method of electrochemically roughening the surface, and a method of selectively dissolving the surface chemically. As a method for mechanically roughening the surface, known methods such as ball polishing, brush polishing, sandblasting, Hojung polishing, etc. can be used. Further, as an electrochemical surface roughening method, there is a method in which alternating current or direct current is used in a hydrochloric acid or nitric acid electrolyte. Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 54-63902, a method combining mechanical surface roughening and electrochemical surface roughening can also be used.

The aluminum plate thus roughened is subjected to alkali etching treatment and neutralization treatment as required.

(Anodizing Treatment) The surface treated in this manner is subsequently subjected to an anodizing treatment.

The electrolyte used for anodizing the aluminum plate may be anything as long as it forms a porous oxide film, and generally sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof, sodium hydroxide, or hydroxide is used as the electrolyte. Potassium or a mixture thereof, ammonium fluoride additive bath, etc. are used, and the electrolyte added to them and its concentration are determined as appropriate depending on the type of electrolyte.The treatment conditions for anodic oxidation vary depending on the type of electrolyte, so they cannot be generalized. Although it cannot be specified, generally the electrolyte concentration is 1-80% by weight, the liquid temperature is 5-80℃, the current density is 5-80A/dm2, and the voltage is 1-80% by weight.
A range of 1 OOV and electrolysis time of 5 seconds to 10 minutes is appropriate.

A particularly preferred anodic oxidation method in the present invention uses sulfuric acid as an electrolyte, particularly as described in British Patent No. 1,412.7.
68 or US Pat. No. 4,211,619 is preferred.

The most preferred anodic oxidation in the present invention is 5 to 20 A/20 A /
This is a method of direct current anodic oxidation at a current density of dm2.

The amount of anodized film is preferably 2-5 g/m'.

(Sealing Treatment) The sealing treatment is a treatment in which holes in a porous anodic oxide film are closed with a metal, oxide, or hydroxide. In the present invention, the pore sealing process is performed by exposing the porous oxide film to a steam atmosphere or immersing it in hot water.

When sealing with steam, pressurized or normal pressure steam is used. When using steam at normal pressure, the processing conditions are a relative humidity of 70% or higher and a steam temperature of 95°C or higher for 2 to 2 seconds.
About a minute is appropriate.

When immersing in hot water, it is preferable to add various additives having a sealing promoting effect to the hot water.

Here, the sealing rate will be used as a measure of sealing.

The sealing rate represents the rate of decrease in the surface area of the oxide film,
It is defined by the formula below.

The above surface area is QUANTASOR, which is a simple BET method.
This is a value measured using B (manufactured by Yuasa Ionics Co., Ltd.).

The aluminum plate that has been subjected to the sealing treatment as described above can be used as a support for a lithographic printing plate immediately as it is, for example, it can be used as a wipe-on support, or it can be coated with a photosensitive layer suitable for lithographic printing. However, in the present invention, it is preferable to further perform treatments such as hydrophilic treatment and application of a hydrophilic undercoat layer alone or in combination after the sealing treatment.

(Hydrophilization treatment) As the hydrophilization treatment used in the present invention, US Pat.
．． No. 714.066 and U.S. Patent No. 3.181.461
Alkali metal silicates (e.g. sodium silicate aqueous solution) as disclosed in Japanese Patent Publication No. 36-22
Potassium fluorozirconate disclosed in Publication No. 063, and U.S. Pat. Nos. 4.153.461 and 4.68
Known methods can be used, such as the method of treatment with polyvinylphosphonic acid as disclosed in No. 9.272. It is desirable to carry out such a hydrophilic treatment especially when a photosensitive layer containing a diazo resin is provided.

(Hydrophilic Undercoat Layer) A preferred hydrophilic undercoat layer used in the present invention is the one disclosed in JP-A-60-149491, which contains at least one amino group, a carboxyl group, and a salt thereof. and at least one group selected from the group consisting of a sulfo group and a salt group thereof;
A hydrophilic layer comprising a compound selected from compounds having at least one amine group and at least one hydroxyl group and salts thereof disclosed in JP-A-60-232998; A hydrophilic layer containing a phosphate as disclosed, a parent tree consisting of a polymer compound containing in its molecule at least one type of monomer unit having a sulfo group as a repeating unit as disclosed in JP-A-59-101651. Contains layers. This undercoat layer may be provided after the above-mentioned sealing treatment, or may be provided after the above-mentioned hydrophilic treatment is performed after the sealing treatment.

Before or after providing such an intermediate layer, the anodized aluminum plate can be treated with an aqueous solution of an alkali metal silicate as described in US Pat. No. 3,181,461. A conventionally known photosensitive layer is provided on the lithographic printing plate support thus obtained.
A photosensitive lithographic printing plate can be obtained, and the lithographic printing plate obtained by plate-making treatment has excellent performance.

As the composition for the above-mentioned photosensitive layer, any composition can be used as long as its solubility or swelling property in a developer changes before and after exposure. The typical ones will be explained below.

(A) Photosensitive layer consisting of an o-quinonediazide compound Examples of the photosensitive compound of the positive photosensitive composition include an 0-quinonediazide compound, and a representative example thereof is an 0-naphthoquinonediazide compound.

As the 0-naphthoquinone diazide compound,
An ester of 1°2-diazonaphthoquinonesulfonic acid chloride and pyrogallol-acetone resin described in Japanese Patent No. 28403 is preferred. Other suitable orthoquinonediazide compounds include U.S. Pat.
There are esters of 1,2-diazonaphthoquinone sulfonic acid chloride and phenol-formaldehyde resins described in the above specification. Other useful 0-naphthoquinone diazide compounds include those reported in numerous patents and known. For example, JP-A No. 47-5303, JP-A No. 48-83802, JP-A No. 48-6
No. 3803, No. 48-96575, No. 49-3870
No. 1, No. 48-13354, Special Publication No. 37-18015
No. 41-11222, No. 45-9610, No. 4
Publication No. 9-17481, U.S. Patent Box 2.797.213
No. 3.454.400, No. 3.544.32
No. 3, No. 3.573.917, No. 3, 674.4
No. 95, No. 3.785.825, British Patent No. 1.2
No. 27.602, No. 1.251.345, No. 1.
No. 267,005, No. 1.329.888, No. 1
．． Examples include those described in various specifications such as No. 330.932 and German Patent No. 854.890.

A particularly preferred O-naphthoquinone diazide compound in the present invention is a compound obtained by reacting a polyhydroxy compound having a molecular weight of 1.000 or less with 1,2-diazonaphthoquinone sulfonic acid chloride. Specific examples of such compounds are disclosed in JP-A-51-139402 and JP-A-58-1989.
No. 150948, No. 58-203434, No. 59-1
No. 65053, No. 60-121.445, No. 60-1
No. 34235, No. 60-163043, No. 61-11
No. 8744, No. 62-10645, No. 62-1064
No. 6, No. 62-153950, No. 62-178562
No. 64-76047, U.S. Patent Box 3.102.8
No. 09, No. 3.126.281, No. 3.130.
No. 047, No. 3, No. 148.983, No. 3.184
．． 310, 3.188.210, 4.63
Examples include those described in various publications or specifications such as No. 9.406.

When synthesizing these 0-naphthoquinone diazide compounds, 1
．． 0.2 of 2-diazonaphthoquinone sulfonic acid chloride
It is preferable to react by 1.2 equivalents, and 0.3 to 1.0 equivalents.
It is more preferable to carry out an equivalent reaction. As the 1.2-diazonaphthoquinone sulfonic acid chloride, 1.2-diazonaphthoquinone-5-sulfonic acid chloride is preferred, but 1.2-diazonaphthoquinone-4-sulfonic acid chloride can also be used.

Moreover, the obtained 0-naphthoquinone diazide compound is 1.
The result is a mixture of compounds with different positions and amounts of 2-diazonaphthoquinone sulfonic acid ester groups, but the proportion of compounds in which all hydroxyl groups have been converted to 1,2-diazonaphthoquinone sulfonic acid esters (completely The content of esterified compounds is preferably 5 mol% or more, more preferably 20 to 9 mol%.
It is 9 mol%.

In addition, as a photosensitive compound that acts positively without using an 0-naphthoquinone diazide compound, for example,
Polymeric compounds having orthonitrocarbinol ester groups as described in No. 696 can also be used in the present invention.

Furthermore, a combination system of a compound that generates an acid upon photolysis and a compound having a 1C-O-C- group or a -○-○-81 group that dissociates with an acid can also be used in the present invention.

For example, a combination of a compound that generates an acid by photolysis and an acetal or an O,N-acetal compound (JP-A-48-1999-1)
89003), a combination with an orthoester or amide acetal compound (JP-A-51-120714), a combination with a polymer having an acetal or ketal group in the main chain (JP-A-53-133429), and an enol ether compound. combination (JP-A-55-12995), N
- Combination with acylimino carbon compound (JP-A-55-1
26236), a combination with a polymer having an orthoester group in the main chain (JP-A-56-17345), a combination with a silyl ester compound (JP-A-60-10247), and a combination with a silyl ether compound (JP-A-56-10247). 1986-
No. 37549, JP-A-60-121446), etc.

The amount of these positive-acting photosensitive compounds (including the above-mentioned combinations) in the photosensitive composition of the present invention is suitably 10 to 50% by weight, more preferably 15 to 50% by weight.
It is 40% by weight.

Although the 0-quinonediazide compound alone constitutes the photosensitive layer, it is preferable to use a resin soluble in alkaline water as a binder together with this type of resin. Examples of resins soluble in alkaline water include Labolac resins having this property, such as phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m-/p-
Cresol formaldehyde resins such as mixed cresol formaldehyde resins, phenol/cresol (either m-1p-1 or m-/p-mixed) mixed formaldehyde resins, phenol-modified xylene resins, polyhydroxystyrene, polyhalogenated hydroxystyrene, 4t [Acrylic resin containing a phenolic hydroxyl group as disclosed in Japanese Patent Publication No. 51-34711, acrylic resin containing a sulfonamide group as disclosed in Japanese Patent Application Laid-Open No. 2-866, urethane resin, Various alkali-soluble polymer compounds such as the following can be contained. These alkali-soluble polymer compounds have a weight average molecular weight of 500 to 20,000 and a number average molecular weight of 200.
~60.000 is preferred.

Such alkali-soluble polymer compound accounts for 70% of the total composition.
It is used in an amount of less than % by weight.

Furthermore, as described in U.S. Pat. No. 4,123,279, phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, It is preferable to use a condensate with the above compound in combination to improve the oil sensitivity of the image.

The photosensitive composition of the present invention may contain a cyclic acid anhydride to increase sensitivity, a printing agent to obtain a visible image immediately after exposure, a dye as an image coloring agent, and other fillers. can. Examples of the cyclic acid anhydride include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and 3,6-nindooxy-△4-tetrahydrophthalic anhydride as described in U.S. Pat. No. 4,115,128. , tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride, and the like. 1 of these cyclic acid anhydrides based on the weight of the total composition.
By containing from 15% by weight, the sensitivity can be increased up to about 3 times.

Typical print-out agents that provide a visible image immediately after exposure include a combination of a photosensitive compound that releases an acid upon exposure and an organic dye that can form a salt. Specifically, JP-A-50-36209, JP-A-53-8
The combination of 0-naphthoquinonediazide-4-sulfonic acid halide and a salt-forming organic dye described in JP-A No. 128, and JP-A-53-36223 and JP-A-54-74728.
For example, combinations of a trihalomethyl compound and a salt-forming organic dye described in Japanese Patent No. 60-3626, No. 61-143748, No. 61-151644, and No. 63-58440 can be mentioned.

In addition to the above-mentioned salt-forming organic dyes, other dyes can also be used as image coloring agents. Suitable dyes include oil-soluble dyes and basic dyes, including salt-forming organic dyes. Specifically, oil yellow #101, oil yellow #130, oil pink #312, oil green BG, oil blue BO3, oil blue #6
03, Oil Black BY, Oil Black BS, Oil Black T-505 (manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (C
I42535), rhodamine B (CI45170B)
, malachite green (CI 42000), methylene blue (CI 52015), and the like.

Moreover, the dyes described in JP-A-62-293247 are particularly preferred.

The photosensitive composition in the present invention is dissolved in a solvent that dissolves each of the above components and applied onto a support. The solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
-Methoxyethyl acetate, 1-methoxy-2-propanol, 1-methoxy-2-propylacetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, dimethylacetamide, dimethylformamide, water, N-methylpyrrolidone, Examples include tetrahydrofurfuryl alcohol, acetone, diacetone alcohol, methanol, ethanol, isopropanol, diethylene glycol, and dimethyl ether, and these solvents can be used alone or in combination. The concentration (solid content) of the above components is 2 to 50% by weight.

The coating amount varies depending on the application, but for example, for photosensitive planographic printing plates, the solid content is generally 0.5 to 3.
．． 0 g/m'' is preferable.As the coating amount becomes thinner, the photosensitivity increases, but the physical properties of the photosensitive film deteriorate.

In the photosensitive composition of the present invention, a surfactant for improving coating properties, for example, a fluorine-based surfactant as described in JP-A-62-170950 can be added. . The preferred amount added is 0.01 to 1% by weight of the total photosensitive composition, more preferably 0.05 to 0.
．． It is 5% by weight.

(B) Photosensitive layer consisting of diazo resin and binder: As a negative-working photosensitive diazo compound, US Pat. No. 2.06
Diphenylamine, which is a reaction product of the diazonium salt disclosed in No. 3.631, No. 2.667, and No. 415, and an organic condensing agent containing a reactive carbonyl group such as aldol or acecool. Other useful condensed diazo compounds in which a condensation product of p-diazonium salt and formaldehyde (so-called photosensitive diazo resin) is suitably used are disclosed in Japanese Patent Publication Nos. 49-48001 and 49-4.
It is disclosed in each publication such as No. 5322 and No. 49-45323. These types of photosensitive diazo compounds are usually obtained in the form of water-soluble inorganic salts and can therefore be coated from aqueous solution. In addition, these water-soluble diazo compounds were
A substantially water-insoluble reaction product obtained by reacting with an aromatic or aliphatic compound having one or more phenolic hydroxyl groups, sulfonic acid groups, or both by the method disclosed in Publication No. 7-1167. It is also possible to use photosensitive diazo resins.

It can also be used as a reaction product with hexafluorophosphate or tetrafluoroborate as described in JP-A-56-I21031.

Examples of reactants with phenolic hydroxyl groups include diphenolic acids such as hydroxybenzophenone, 4,4-bis(4'-hydroxyphenyl)pentanoic acid, resorcinol, or diresorcinol, which may further contain substituents. It may have. Hydroxybenzophenone includes 2゜4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2.2'-
Dihydroxy-4,4'-dimethoxybenzophenone or 2,2',4,4'-tetrahydroxybenzophenone is included. Preferred sulfonic acids and compounds include aromatic sulfonic acids such as sulfonic acids such as benzene, toluene, xylene, naphthalene, phenol, naphthol and benzophenone, or soluble salts thereof, such as ammonium and alkali metal salts. .

Sulfonic acid group-containing compounds may generally be substituted with lower alkyl, nitro groups, halo groups, and/or another sulfonic acid group. Preferred examples of such compounds include benzenesulfonic acid, toluenesulfonic acid,
Naphthalene sulfonic acid, 2゜5-dimethylbenzenesulfonic acid, sodium benzenesulfonate, naphthalene-
2-sulfonic acid, 1-naphthol-2 (or 4)-sulfonic acid, 2゜4-dinitro-1-naphthol-7-sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, m-( Examples include sodium p'-anilinophenylazo)benzenesulfonate, alizarinsulfonic acid, o-toluidine-1m-sulfonic acid, and ethanesulfonic acid. Sulfonic esters of alcohols and their salts are also useful. Such compounds are usually readily available as anionic surfactants. Examples include ammonium salts or alkali metal salts such as lauryl sulfate, alkylaryl sulfate, p-nonylphenyl sulfate, 2-phenylethyl sulfate, isooctylphenoxyjethoxyethyl sulfate.

These substantially water-insoluble photosensitive diazo resins can be isolated as a precipitate by mixing the water-soluble photosensitive diazo resin and an aqueous solution of the aromatic or aliphatic compound, preferably in approximately equal amounts. It can be done.

Also preferred are the diazo resins described in GB 1.312.925.

In addition, diazo resins containing phosphorus oxygen acid groups, which are described in Japanese Patent Application No. 53101/1998, and Japanese Patent Application No.
Diazo resin condensed with a carboxyl group-containing aldehyde or its acetal compound described in No. 130493, and a carboxyl group-containing aromatic compound such as phenoxyacetic acid described in Japanese Patent Application No. 2-40690. Cocondensed diazo resins are also preferred.

The most preferred diazo resin is 2-methoxy-4-condensate of p-diazodiphenylamine and formaldehyde.
Hydroxy-5-benzoylbenzene sulfonate.

The appropriate content of the diazo resin in the photosensitive layer is 5 to 50% by weight. As the amount of diazo resin decreases, photosensitivity naturally increases, but stability over time decreases. The optimum amount of diazo resin is about 8-20% by weight.

On the other hand, various polymer compounds can be used as the binder, but in the present invention, hydroxy, amino,
Carboxylic acids, amides, sulfonamides, activated methylene,
Those containing groups such as thioalcohol and epoxy are desirable. Such preferred binders include those described in British Patent No. 1.
350.521, British Patent No. 1.460°978 and US Patent No. 4.1
Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as a main repeating unit as described in U.S. Pat. No. 3,751,257; Ryomid resins, phenolic resins as described in British Patent No. 1.074.392 and polyvinyl acetal resins such as polyvinyl formal resins, polyvinyl butyral resins, U.S. Pat. No. 3,66
Linear polyurethane resins, polyvinyl alcohol phthalate resins, epoxy resins condensed from bisphenol A and epichlorohydrin, polyaminostyrene and polyalkylamino (
polymers containing amino groups, such as meth)acrylates,
Included are cellulose derivatives such as cellulose acetate, cellulose alkyl ether, and cellulose acetate phthalate.

The composition of diazo resin and binder may further include a pH indicator as described in British Patent No. 1.041.463, a pH indicator as described in U.S. Pat. No. 3.236.646. Additives such as phosphoric acid and dyes can be added.

(C) Photosensitive layer consisting of an azide compound and a binder (polymer compound), for example, British Patent No. 1.235.281, British Patent No. 1.49
Specifications of No. 5.861 and JP-A-51-32331
In addition to the compositions comprising a phosphor compound and a water-soluble or alkali-soluble polymer compound described in JP-A No. 51-36128, JP-A No. 50-5102, JP-A No. 50-50-
No. 84302, No. 50-84303, No. 53-129
Included are compositions consisting of a polymer containing an azide group and a polymer compound as a binder, as described in each publication of No. 84.

(D) Other photosensitive resin layers For example, polyester compounds disclosed in JP-A-52-96696, British Patent No. 1,112, 277
No. 1.313.390, No. 1.341.00
Polyvinyl cinnamate resins described in specifications such as No. 4, No. 1.377, and No. 747, U.S. Patent No. 4.072
．． The photopolymerizable photopolymer compositions described in the specifications of No. 528 and No. 4.072.527 are included.

(E) Electrophotographic photosensitive layer The electrophotographic photosensitive layer mainly consists of a photoconductive compound and a binder, but if necessary, known pigments may be added for the purpose of improving sensitivity and obtaining a desired photosensitive wavelength range. , dyes, chemical sensitizers, other additives, etc. can be used.

The photosensitive layer can be composed of a single layer or a plurality of layers in which charge generation and charge transport functions are separated. A lithographic printing plate can be obtained by forming a toner image on a photosensitive layer by a known electrophotographic process, and using this as a resist layer, decoding non-image areas. For example, Japanese Patent Publication No. 37-17162, Japanese Patent Publication No. 38-6961, Japanese Patent Publication No. 56-107246, Japanese Patent Publication No. 60-254142,
JP 59-36259, JP 59-25217, JP 56-146145, JP 62-194257,
It is described in numerous publications including No. 57-147656, No. 58-100862, and No. 57-161863, and any of these can be suitably used.

The thickness of the photosensitive layer is preferably 0.1-30 μm1,
It can be used at 0.5-10 μm.

The amount (solid content) of the photosensitive layer provided on the support is approximately 0.1
~7 g/m', preferably 0.5-4 g/m'
' range. After the lithographic printing plate is imagewise exposed, a resin image is formed by a conventional process including development.

For example, in the case of a positive planographic printing plate having a photosensitive layer (A), after image exposure, the exposed areas are developed by developing with an alkaline aqueous solution as described in U.S. Pat. No. 4,259,434. The photosensitive layer is removed to obtain a lithographic printing plate.

In addition, in the case of a negative planographic printing plate having a photosensitive layer (B) consisting of a diazo resin and a binder, after image exposure, it is developed with a developer such as that described in U.S. Pat. No. 4,186,006. By doing so, the unexposed portions of the photosensitive layer are removed and a lithographic printing plate is obtained.

(Effects of the invention) The method of the present invention increases the amount of anodic oxide film compared to the conventional method;
There are no drawbacks associated with sealing the oxide film using hot water or steam. Furthermore, a lithographic printing plate using a support obtained according to the present invention has superior strength and corrosion resistance in non-image areas compared to those using a conventional support.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples. In addition, (%) in the examples is (weight%) unless otherwise specified.
shall be.

(Example 1) The surface of a JISA 1050 aluminum sheet was grained using a rotating nylon brush using a pumice water suspension as an abrasive. The surface roughness (center line average roughness) at this time was 0.5μ. After washing with water, it was etched by immersing it in a 10% aqueous solution of caustic soda heated to 70°C so that the amount of aluminum dissolved was 6 g/m. After washing with water, it was immersed in a 30% aqueous nitric acid solution for 1 minute. It was neutralized and thoroughly washed with water.Then, electrolytic surfaceization was carried out for 20 seconds in a 0.7% nitric acid aqueous solution using a square wave alternating waveform voltage with an anode special voltage of 13 volts and a cathode special voltage of 6 volts. After cleaning the surface by immersing it in a 50°C solution of % sulfuric acid, it was washed with water.

Furthermore, a porous anodic oxide film formation treatment was performed using direct current in a 20% sulfuric acid aqueous solution. Electrolysis was carried out at a current density of 5 A/dm2, and the electrolysis time was adjusted to adjust the weight of the anodic oxide film to 4.
A substrate of 0 g/m' was made. This substrate was treated for 10 seconds in a saturated steam chamber at 100° C. and 1 atm to produce a support (substrate ①) with a sealing rate of 60%.

A solution (A) consisting of 1 g of β-alanine, 5 g of water, and 94 g of methanol was applied to the surface of the substrate (dry weight 20 mg/m2).
' and dried at 80°C for 30 seconds. The following composition was coated onto the thus prepared substrate so that the coating weight after drying was 2.5 g/m' and dried to provide a photosensitive layer.

Photosensitive composition Ester compound of naphthoquinone-1,2-diazido-5-sulfonyl chloride and pyrogallol-acetone resin 0.75 g (U.S. Pat. No. 3.635
．． 709 Specification, Example 1) Cresol novolac resin 2.00 g Oil Blue #603 (Orient Chemicals) 0.04 g Ethylene dichloride 16 g 2-methoxyethyl acetate 12 g Photosensitive lithographic printing thus produced The plate was exposed in a vacuum printing frame through a transparent positive film for 50 seconds using a 3μW metal halide lamp from a distance of 1m, and then exposed to SlO□.
5.2 of sodium silicate with a molar ratio of /NaJ of 1.74.
It was developed with a 6% aqueous solution (pH=12.7).

After developing in this manner, the film was thoroughly washed with water and gummed, and then printed using a conventional procedure. At this time, ■ strength of non-image area, ■ corrosion resistance of non-image area, ■ ease of dye remaining on non-image area, ■ reproducibility of highlight area, ■ hydrophilicity after development, and ■
The printing durability was evaluated. The results are shown in Table 1.

(Example 2) Same as Example I except that the weight of the anodic oxide film was 2.0 g/m' and the treatment was performed for 6 seconds in a saturated steam chamber at 100°C and 1 atm to give a sealing rate of 40%. The same operation was repeated. The printing results are shown in Table 1.

(Example 3) Example 1 except that the anodic oxide film weight was 5.0 g/m' and the treatment was performed for 15 seconds in a saturated steam chamber at 100°C and 1 atm to achieve a sealing rate of 95%. The same operation was repeated. The printing results are shown in Table 1.

(Example 4) The same operation as in Example 1 was repeated except that instead of the β-alanine undercoat treatment, a 1-minute immersion treatment was performed in a 1% polyvinylphosphonic acid aqueous solution (60° C.). The printing results are shown in Table 1.

(Example 5) The weight of the anodic oxide film was 6.0 g/m'', 100°C, 1
The same operation as in Example 1 was repeated, except that the treatment was carried out for 10 seconds in a steam chamber saturated at atmospheric pressure to achieve a sealing rate of 60%. The printing results are shown in Table 1.

(Example 6) Example except that instead of the β-alanine undercoating treatment, a solution (B) of 1 g of phenylphosphonic acid, 5 g of water, and 94 g of methanol was applied so that the weight after drying was 20 mg/m' The same operation as 1 was repeated. The printing results are shown in Table 1.

(Comparative Example 1) The same operation as in Example 1 was repeated except that the β-alanine undercoating treatment was not performed. The printing results are shown in Table 1.

(Comparative Example 2) The weight of the anodic oxide film was 1.0 g/m'', 100°C, 1
The same operation as in Example 1 was repeated, except that the treatment was carried out for 10 seconds in a steam chamber saturated at atmospheric pressure to achieve a sealing rate of 60%. The printing results are shown in Table 1.

(Comparative Example 3) The same operation as in Example 1 was repeated except that the sealing treatment was not performed. The printing results are shown in Table 1.

(Comparative Example 4) The same operation as in Example 1 was repeated except that the sample was treated for 2 minutes in a saturated steam chamber at 100° C. and 1 atm to achieve a sealing rate of 100%.

The printing results are shown in Table 1.

(Example 7) The substrate material of Example 1 was immersed in a No. 3 sodium silicate 2.5% aqueous solution at 10° C. for 30 seconds, washed with water, and dried. The following composition was applied to the substrate thus prepared so that the coating weight after drying was 2.0.
g/m' and dried to provide a photosensitive layer.

Photosensitive composition N-(4-hydroxyphenyl)methacrylamide/2
-Hydroxyethyl methacrylate/acrylonitrile/methyl methacrylate/methacrylic acid (=15:10
:30:38 near molar ratio) copolymer (average molecular weight 600
00)・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・ 5.0g Hexafluorophosphate, a condensate of 4-diazodiphenylamine and formaldehyde Group... 0.5 g Phosphorous acid...
・・・・・・・・・・・・・・・ Old・・・・・・・・・
... 0.05 g Victoria Pure Blue BOH
(Manufactured by Sakudogaya Chemical Co., Ltd.)・・・・・・・・・・・・
......Old...0.1 g2-Methoxyethanol...100 gThe photosensitive lithographic printing plate made in this way was placed in a vacuum printing frame Inside,
3KW from a distance of 1m through a transparent negative film
After exposure for 50 seconds using a metal halide lamp, the plate was developed with a developer having the composition shown below, and gummed with an aqueous gum arabic solution to prepare a lithographic printing plate. Printing was carried out using this printing plate according to a conventional procedure.

Developer solution Sodium sulfite・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・ 5g benzyl alcohol...
・・・・・・・・・・・・・・・・・・ 30g Sodium carbonate・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・ 5g Sodium isopropylnaphthalene sulfonate・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
12g pure water・・・・・・・・・・・・・・・
・・・・・・・・・・・・ 1000g ■
Strength of non-image area, ■ Stains due to irreversible adsorption of the photosensitive composition and polymer binder to the support surface over time, ■ Reproducibility of halftone dots in shadow areas, ■ Hydrophilicity of non-image area and (2) The results of examining printing durability are shown in Table 2.

(Example 8) Same as Example 7 except that the weight of the anodic oxide film was 2.0 g/m' and the treatment was performed for 6 seconds in a saturated steam chamber at 100°C and 1 atm to achieve a sealing rate of 40%. The same operation was repeated. The printing results are shown in Table 2.

(Example 9) Same as Example 7 except that the anodic oxide film weight was 5.0 g/m' and the treatment was performed for 15 seconds in a saturated steam chamber at 100°C and 1 atm to achieve a sealing rate of 95%. The same operation was repeated. The printing results are shown in Table 2.

(Example 10) Example 7 except that the anodic oxide film weight was 6.0 g/m' and the sealing rate was 60% by processing for 10 seconds in a saturated steam chamber at 100° C. and 1 atm. The same operation was repeated. The printing results are shown in Table 2.

(Above Comparative Example 5) Example 7 except that the anodic oxide film weight was 1.0 g/m'' and the sealing rate was 60% by processing for 10 seconds in a saturated steam chamber at 100°C and 1 atm. The same operations as above were repeated.The printing results are shown in Table 2.

- (Comparative Example 6) The same operations as in Example 7 were repeated except that the sealing treatment was not performed. The printing results are shown in Table 2.

(Comparative Example 7) The same operation as in Example 7 was repeated except that the sample was treated for 2 minutes in a saturated steam chamber at 100° C. and 1 atm to achieve a sealing rate of 100%.

The printing results are shown in Table 2.

The printing performance evaluation method shown in Tables 1 and 2 is as follows.

"Strength of non-image area": The non-image area of a developed and gummed lithographic printing plate was measured using a scratch strength tester manufactured by Shinto Kagaku Co., Ltd., to a value of 100 to 40.
The scratching load was measured using a diamond needle with a load of 0 g applied, and evaluation was made based on the following criteria.

A: No damage even with 200g.

B: No scratches occur at 100g, but scratches occur at 200g.

C: Scratches occur at 100g.

"Corrosion resistance of non-image area": A lithographic printing plate was immersed in a commercially available plate cleaner, and the non-image area was rubbed 500 times with a rubber blanket of a printing machine, and the degree of wear was visually determined according to the following criteria.

A: No wear at all.

B: It has started to wear out to some extent.

C: Oxide film disappeared.

"Easiness of dye remaining on non-image areas": Reflection optical density at 600 nm light of the non-image area of the lithographic printing plate after development and reflection optical density at 600 nm light of the support surface before coating the photosensitive layer. The difference (ΔD) was measured and evaluated based on the following criteria.

A: △D≦0.005 B: 0.005<△D≦0.01 C: 0.01<△D≦0.02 D: 0.02<△D≦0.03 E: 0.03< △D≦0.04 F: 0.04 <△D ``Reproducibility of highlight areas'': A FOGRA value chart was printed under the same exposure conditions, developed, and printed with a gummed lithographic printing plate.
Evaluation was made according to the following criteria based on the value of the minimum width of a thin line that could be reproduced without skipping on printed matter.

A: Value ≦10μ B: Value 12μ≦≦15μ C: Value 20μ≦ “Hydrophilicity after development”: Measure the contact angle (water droplets in oil) of the non-image area after development and evaluate according to the following criteria. did.

A: 10 degrees or less B: 20 degrees to 40 degrees C: 60 degrees or more "stains in non-image areas": The photosensitive lithographic printing plate was stored at 45 degrees Celsius and 75% relative humidity for 3 days before plate making. The degree of staining of the non-image area of the printed matter when printed using the lithographic printing plate obtained was evaluated according to the following criteria.

A: No stains at all.

B: There is some dirt.

C: Very dirty.

"Reproducibility of halftone dots in some shadows": The smallest width fine line that can be reproduced without being crushed on printed matter by printing FOGRA's value chart on a lithographic printing plate that has been printed under the same exposure conditions, developed, and gummed. The evaluation was made according to the following criteria.

A: Value ≦lOμ B: Value 12≦≦15μ C: Value 20μ≦ “Press durability” in Table 1: Relative evaluation table when the printing durability of the lithographic printing plate of Example 1 is taken as 100% 2 "Press life": Relative evaluation procedure amendment 3, 1.14 when the printing life of the lithographic printing plate of Example 7 is taken as 100% 1998, month, day 1, case description 1990 patent application No. 306415 2, Title of the invention Method for producing support for lithographic printing plate 3
, Relationship to the case of the person making the amendment Applicant name (520> Fuji Photo Film Co., Ltd. 4,
Agent 5, Date of amendment order Initiator 6, Subject of amendment Column 7 of detailed explanation of the invention in the specification, Contents of amendment (1) “JrSAIQ50” on page 31, line 11 of the specification
is corrected to rJIs A1050j.

(2) "β-alanine 1g" on page 32, line 11 of the same book is corrected to ~ββ-alanine 1gg-.

(3) “Phenylphosphophone 1” in the same book, page 35, lines 5-6.
121g'' - Corrected to 0.1g of phenylphosphonic acid.

Claims (2)

[Claims] (1) After roughening the surface of the aluminum plate and anodizing it so that the amount of the anodic oxide film is 2 g/m^2 or more, the pores are sealed with hot water or steam to reduce the surface area of the oxide film to 40~ A method for producing a support for a lithographic printing plate, which comprises reducing the support by 95% and then subjecting it to a hydrophilic treatment and/or a hydrophilic undercoating treatment. (2) The method for producing a support for a lithographic printing plate according to claim (1), wherein the amount of the oxide film is 2 to 5 g/m^2.