JPH062435B2 - Support for planographic printing plates - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a lithographic printing plate support, and more particularly to a lithographic printing plate support comprising an anodized aluminum plate having an improved hydrophilic layer. Is.

[Prior art]

Conventionally, a lithographic printing plate includes a so-called PS plate in which a photosensitive composition is applied in a thin layer on an aluminum plate, but the above-mentioned aluminum plate is usually a mechanical method such as a brush grain method or a ball grain method or It is subjected to a surface-roughening treatment such as an electrochemical method such as an electrolytic grain method or a method combining both methods, and after the surface is made satin-finished, it is etched with an aqueous solution of acid or alkali, and further anodized. After that, it is subjected to a hydrophilizing treatment as desired to obtain a support for a lithographic printing plate, and a photosensitive layer is provided on this support to obtain a PS plate (lithographic printing plate). This PS plate is usually subjected to image exposure, development, correction and gumming steps to obtain a lithographic printing plate, which is attached to a printing machine for printing.

However, in the above lithographic printing plate, the positive action P
Substances contained in the photosensitive layer are irreversibly adsorbed to the non-image area of the lithographic printing plate obtained by imagewise exposing and developing the S plate, and contaminate the non-image area. There is a problem that it is difficult to identify the image portion, or the correction marks are clearly left and the plate surface becomes uneven, and when the degree of the correction becomes severe, it becomes dirty and cannot be used as a printing plate.

To remedy this, it is conventional in US Pat. No. 3,860,426 to dip the anodized aluminum support surface in an alkali metal silicate as described in US Pat. No. 3,181,461. It has been proposed to apply a treatment such as a subbing method of hydrophilic cellulose containing a water-soluble metal salt as described, or a subbing method of sodium aryl sulfonate as described in British Patent No. 2098627. As a result, it is possible to prevent the above-mentioned non-image portion from being contaminated and prevent "smudge" from occurring on the printed matter, but on the other hand, the printing durability of the printed matter is 30 ~ 80
There was a drawback with the new problem of decreasing to%.

Further, in the case of a PS plate having a negative action, the image part of the planographic printing plate obtained by imagewise exposure and development has low adhesion to the support,
There was a problem that it could not be used for printing a large number of sheets.

In order to improve this, conventionally, the surface of an anodized aluminum support is subjected to a treatment such as a method of providing a thin layer of polyvinylphosphonic acid and its derivative as described in JP-B-44-35685. It has been proposed that it was possible to improve the adhesion of the image portion described above, but on the other hand, there is a new problem that the stain on the non-image portion becomes significantly worse than when the above treatment is not performed. occured. In particular, such a problem was remarkable as the PS plate was manufactured and passed with time.

[Object of the Invention]

An object of the present invention is to provide a lithographic printing plate support capable of obtaining a lithographic printing plate in which the image area is firmly adhered to the support and the non-image area is less likely to be contaminated.

[Structure of Invention]

The present inventors have accomplished the present invention as a result of extensive studies to achieve the above object. The present invention provides a carboxyl group in a hydrocarbon group on the coating of an aluminum plate having an anodic oxide coating. Group or hydroxyl group-containing molecular weight 10
A support for a lithographic printing plate, comprising a hydrophilic layer containing an organic phosphonic acid of 00 or less or a salt thereof.

Hereinafter, the present invention will be described in detail step by step.

The aluminum plate used in the present invention is a plate-shaped body containing aluminum as a main component, such as pure aluminum or an aluminum alloy containing a slight amount of foreign atoms. The different atoms include silicon, iron, manganese, copper, magnesium, chromium,
Examples include zinc, bismuth, nickel and titanium. The alloy composition has a content of at most 10% by weight. The preferred aluminum for the present invention is pure aluminum,
Since completely pure aluminum is difficult to produce due to the kneading technique, it is preferable that it contains as few foreign atoms as possible.
Further, the aluminum alloy having the above content rate can be regarded as a material applicable to the present invention. As described above, the aluminum plate applied to the present invention is not specified in its composition, and conventionally known and officially used materials can be appropriately used. The aluminum plate used in the present invention has a thickness of about 0.1 mm to 0.5 mm.

Prior to anodizing the aluminum plate, a degreasing treatment for removing rolling oil on the surface, for example, treatment with a surfactant or an alkaline aqueous solution, and a graining treatment are optionally performed.

The graining treatment method includes a method of mechanically roughening the surface, a method of electrochemically melting the surface, and a method of chemically selectively melting the surface. As a method for mechanically roughening the surface, a known method called a ball polishing method, a brush polishing method, a blast polishing method, a buff polishing method or the like can be used. Further, as an electrochemical roughening method, there is a method of performing alternating current or direct current in a hydrochloric acid or nitric acid electrolytic solution. Further, as disclosed in Japanese Patent Application Laid-Open No. 54-63902, a method in which both are combined can be used.

The aluminum plate thus roughened is subjected to alkali etching treatment and neutralization treatment, if necessary.

As the electrolyte used for the anodizing treatment of the aluminum plate, any electrolyte that forms a porous oxide film can be used, and generally, sulfuric acid, phosphoric acid, oxalic acid,
Chromic acid or a mixed acid thereof is used, and the concentration of the electrolyte is appropriately determined depending on the type of the electrolyte.

The treatment conditions for anodic oxidation cannot be unconditionally specified because they vary depending on the electrolyte used, but generally the concentration of electrolyte is 1
~ 80 wt% solution, liquid temperature 5 ~ 70 ° C, current density 5 ~ 6
It is suitable that the electrolysis time is 0 A / dm ² , the voltage is 1 to 100 V, and the electrolysis time is 10 seconds to 50 minutes.

The amount of the anodized film is preferably 0.1 to 10 g / m ² , and more preferably 1 to 6 g / m ² . By applying a solution of the following hydrophilic compound dissolved in an organic solvent such as water or methanol on the anodized film of the aluminum plate that has been subjected to the above-mentioned treatment and drying it to form a hydrophilic layer, the planographic printing plate of the present invention can be obtained. A support for printing plates is obtained.

The hydrophilic compound used in the present invention is an organic phosphonic acid having a carboxyl group or a hydroxyl group in a hydrocarbon group and a molecular weight of 1,000 or less, or a salt thereof. Here, part or all of the phosphon group and / or the carboxyl group may be in the form of a salt.

The organic phosphonic acid referred to in the present invention is And an organic phosphonic acid represented by The organic phosphinic acid represented by the general formula is included.

Among these compounds, the useful compound used in the present invention is 1-hydroxyalkane-1,1-diphosphonic acid, specifically 1-hydroxy-1,1-diphosphonic acid and 1-hydroxy-1. -Phenylmethane-1,1-
Diphosphonic acid, 1-hydroxypropane-1,1-diphosphonic acid, 1-hydroxybutane-1,1-diphosphonic acid, 1-hydroxypentane-1,1-diphosphonic acid,
1-Hydroxyhexane-1,1-diphosphonic acid and the like.

Phosphosuccinic acid is also a useful compound used in the present invention, specifically, 1-phosphono-methylsuccinic acid,
2-phosphonobutane-1,2,4-tricarboxylic acid and the like. These organic phosphonic acids include alkali metal salts (preferably sodium salt, potassium salt) ammonium salt,
And lower alkanolamine (eg triethanolamine) salts.

The hydrophilic compound as described above is a suitable solvent, for example, water,
0.001 to 10% by weight in alcohol such as methanol
Is dissolved at a concentration of to form a coating solution. At this time, it is appropriate that the pH after coating is in the range of 1 to 13. Further, the temperature of the coating solution is suitably in the range of 10 to 50 ° C.

As a coating method, any method such as dip coating, spin coating, spray coating and curtain coating may be used. The coating amount is 1 to 100 mg / m ² at a coverage after drying is preferred, more preferably from 5 to 50 mg / m ^2. As the coating amount becomes less than 1 mg / m ² , the effect of preventing stains on the non-image area disappears, while 100 mg / m ²
As the amount increases, the adhesion between the photosensitive layer and the support deteriorates, and only a lithographic printing plate having low printing durability can be obtained.

Before or after providing such a hydrophilic layer, the anodized aluminum plate can be treated with an aqueous solution of an alkali metal silicate (eg sodium silicate) as described in US Pat. No. 3,181,461.

On the lithographic printing plate support thus obtained,
As a photosensitive layer of a PS plate (abbreviation of Pre-Sensitized Plate), a photosensitive layer which has been conventionally known can be provided to obtain a photosensitive lithographic printing plate. , Has excellent performance.

As the composition of the above-mentioned photosensitive layer, any composition can be used as long as the solubility or swellability in a developing solution changes before and after exposure. The representative ones will be described below.

As a positive-working photosensitive diazo compound, Japanese Patent Publication No.
-Benzoquinone described in JP-A-28403-
Most preferred are the esters of 1,2-diazidosulfonic acid chloride with polyhydroxyphenyl or the esters of naphthoquinone-1,2-diazidosulfonic acid chloride with pyrogallol-acetone resin. Other relatively suitable o-quinonediazide compounds include benzoquinone-1,2-diazidesulfonic acid chloride or naphthoquinone-1,2 described in U.S. Pat. Nos. 3,046,210 and 3,188,210. There are esters of diazide sulfonic acid chloride with phenol formaldehyde resins. The o-quinonediazide compound alone constitutes the photosensitive layer, but it is used together with a resin soluble in alkaline water as a binder. As the resin soluble in alkaline water, there are novolac resins having this property, such as phenol formaldehyde resin, cresol formaldehyde resin, pt-butylphenol-formaldehyde resin, phenol-modified xylene resin, and phenol-modified xylene-mesitylene resin. Is. Other useful alkaline water-soluble resins include polyhydroxystyrene, copolymers of polyhalogenated hydroxystyrenated (meth) acrylic acid and other vinyl compounds.

Dyes include basic dyes and oil-soluble dyes. Specifically, Victoria Pure Blue BOH, Victoria Blue BR, Methyl Violet, Eisen Malachite Green (above, Hodogaya Chemical Co., Ltd.), Patent Pure Blue VX, Rhodamine B, Methylene.・ Basic dyes such as blue (manufactured by Sumitomo Chemical Co., Ltd.), Sudan Blue II, Victoria
Blue-F4R (above, BASF), Oil-Blue # 603, Oil-Blue BOS, Oil-Blue IIN (above, manufactured by Orient Chemical Industry)
Oil-soluble dyes such as

Of these dyes, basic dyes are preferable, and those whose counter anion has one sulfonic acid group such as naphthalenesulfonic acid as the only exchange group are most preferable.

1,2-naphthoquinone-as a photodegradable acid generator
In addition to (2) -4-sulfonic acid chloride, JP-A-53-3
No. 6223, trihalomethyl-2-pyrone and trihalomethyltriazine, various o-naphthoquinonediazide compounds described in JP-A-55-62444,
A 2-trihalomethyl-5-aryl-1,3,4-oxadiazole compound described in JP-A-55-77742 may be added.

Further details of the photosensitive layer comprising the o-quinonediazide compound and its developer are described in detail in US Pat. No. 4,259,434.

A photosensitive composition comprising a diazo resin and a binder.

US Patent No. 2063 as a negative-working photosensitive diazo compound.
Diphenylamine-p-diazonium salts and forms which are reaction products of diazonium salts and organic condensing agents containing a reactive carbonyl group such as aldol and acetal, which are disclosed in each of 631 and 2667415. A condensation product with an aldehyde (so-called photosensitive diazo resin) is preferably used. Other useful fused diazo compounds are U.S. Pat. No. 3,679,419, British Patent Nos. 1312925, 1312926.
Are disclosed in the respective specifications and the like. These types of photosensitive diazo compounds are usually obtained in the form of water-soluble inorganic salts and can therefore be coated from aqueous solutions. Also, these water-soluble diazo compounds are reacted with an aromatic or aliphatic compound having one or more phenolic hydroxyl groups, sulfonic acid groups or both by the method disclosed in British Patent No. 1,280,885, A substantially water-insoluble photosensitive diazo resin which is a reaction product thereof can also be used.

It can also be used as a reaction product with a hexafluorophosphate or a tetrafluoroborate as described in JP-A-56-121031.

In addition, diazo resins described in British Patent No. 1312925 are also preferable.

Such a diazo resin is used together with a binder. A preferred binder is an organic polymer having an acid value of 10 to 200, and specific examples thereof include acrylic acid,
A copolymer containing methacrylic acid, crotonic acid or maleic acid as an essential polymerization component, for example, US Pat. No. 4,123,276.
Tertiary or quaternary with 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, acrylonitrile or methacrylonitrile, acrylic acid or methacrylic acid and optionally other copolymerizable monomers as described in US Pat. Original copolymer, JP-A-53-
Acrylic acid or methacrylic acid having a hydroxy group at the terminal as described in 120903 and esterified with a group containing a dicarboxylic acid ester residue, and optionally further copolymerizable monomer Copolymer, a monomer having an aromatic hydroxyl group at the terminal as described in JP-A-54-98614 (for example, N- (4-
(Hydroxyphenyl) methacrylamide etc.), acrylic acid or methacrylic acid, and optionally a copolymer with at least one other copolymerizable monomer, as described in JP-A-56-4144. Included are copolymers of alkyl acrylates or methacrylates, acrylonitrile or methacrylonitrile, and unsaturated carboxylic acids. Further, acidic polyvinyl alcohol derivatives and acidic cellulose derivatives are also useful.

In the main chain or side chain of the polymer Composition comprising a polymer compound containing a group as a photosensitive group in the main chain or side chain of a polymer Containing a photosensitive polymer as a main component such as polyesters, polyamides, and polycarbonates containing (for example, as described in U.S. Pat. Nos. 3,030,208, 3,707,373 and 3,453,237). Compounds based on (2-properidene) malonic acid compounds such as cinnamylidene malonic acid and photosensitive polyesters derived from bifunctional glycols (for example, US Patent Nos. 2956878 and 3173787). Photosensitizers as described in each of the specifications); cinnamic acid esters of hydroxyl-containing polymers such as polyvinyl alcohol, starch, cellulose and the like (eg, US Pat. No. 2690966, Photopolymers as described in the respective specifications of Nos. 2752372, 2732301 and the like are included. In addition to these, a sensitizer, a stabilizer, a plasticizer, a pigment or a dye may be contained in these compositions.

A so-called photopolymerizable composition that causes a polymerization reaction upon irradiation with actinic rays. For example, there are compositions comprising an addition-polymerizable unsaturated compound having two or more terminal ethylene groups and a photopolymerization initiator described in U.S. Pat. Nos. 2,760,863 and 3060023.

The compound that dimerizes upon irradiation with actinic rays and the compound that undergoes a polymerization reaction may further contain a resin as a binder, a sensitizer, a thermal polymerization inhibitor, a dye, a plasticizer, and the like.

The photosensitive composition as described above is usually applied as a solution of water, an organic solvent, or a mixture thereof on the support according to the present invention and dried to prepare a photosensitive lithographic printing plate.

The coating amount of the photosensitive composition is generally about 0.1 to about 5.
0 g / m ² is suitable, with about 0.5 to about 3.0 g / m ² being more preferred.

The photosensitive lithographic printing plate thus obtained is subjected to imagewise exposure with a light source containing an actinic ray such as a carbon arc lamp, a xenon lamp, a mercury lamp, a tungsten lamp, a metal halide lamp, and the like, and developed to obtain a lithographic printing plate.

〔The invention's effect〕

The lithographic printing plate using the aluminum support obtained by the present invention gives higher printing durability than the conventional one and, at the same time, has a remarkable effect that the non-image area is less likely to be stained. Conventionally, a lithographic printing plate having high printing durability has a property that the non-image area is easily soiled, and conversely, a lithographic printing plate which is less likely to be soiled in the non-image area has a property that the printing durability is low. It was said to be extremely difficult to do.

However, the lithographic printing plate using the aluminum support according to the present invention has high printing durability and, at the same time, has an unprecedented excellent property that the non-image area is hardly soiled.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples. In addition, "%" in the examples means "% by weight" unless otherwise specified.

Example 1 The surface of a JIS 1050 aluminum sheet was grained with a rotating nylon brush using a Pumisu water suspension as an abrasive.
The surface roughness (center line average roughness) at this time was 0.5 μm. After washing with water, immerse a 10% aqueous solution of caustic soda in a solution warmed to 70 ° C. to dissolve aluminum in an amount of 6 g / m ²
It was etched to become. After washing with water, it was immersed in a 30% aqueous nitric acid solution for 1 minute for neutralization, and then thoroughly washed with water. After that,
In a 0.7% nitric acid aqueous solution, an alternating rectangular wave having a voltage of 13 V at the anode and a voltage of 6 V at the cathode was used (JP-A-52).
Power supply waveform described in the example of Japanese Patent Publication No. 77702)
After electrolytic surface roughening for 20 seconds, the surface was washed by immersing it in a 50% solution of 20% sulfuric acid, and then washing with water.

70 g / sulfuric acid aqueous solution (Al ion concentration 7 g /
Substrate (I) was prepared after anodic oxidation treatment using direct current so that the weight of the anodic oxide coating was 3.0 g / m ^{2 in} (4), washing with water, and drying.

The surface of the substrate (I) thus treated was coated with the solution (A) having the following composition and dried at 80 ° C. for 30 seconds.

The coating amount after drying was 10 mg / m ² .

In this way, the substrate (II) was prepared.

Further, a solution (B) having the following composition was applied on the substrate (I) using trihydroxyethylidene-1,1-diphosphonic acid and dried at 80 ° C. for 30 seconds.

The coating amount was 10 mg / m ² after drying.

In this way, the substrate (III) was prepared.

Further, 1-phosphoethane-1,1,2-tricarboxylic acid was used to apply a solution (C) having the following composition onto the substrate (I) and dried at 80 ° C. for 30 seconds. The coating amount is 10 after drying.
It was mg / m ² .

In this way, the substrate (IV) was prepared.

Furthermore, for comparison, carboxymethyl cellulose (molecular weight 25000) or polyvinyl alcohol (molecular weight 10
000) is dissolved in water and the coating amount after drying is 10 mg.
The substrate (V) and the substrate (VI) were provided on the substrate (I) so as to be / m ² . Further, an aqueous solution of polyvinylphosphonic acid (molecular weight: about 10,000) was provided on the substrate (I) so that the coating amount after drying was 10 mg / m ^2, and the substrate (V
II).

Substrates (I) to (VII) thus prepared were provided with a photosensitive layer such that the coating weight of the following composition after drying was 2.5 g / m ² .

The photosensitive lithographic printing plate thus prepared was exposed in a vacuum baking frame through a transparent positive film from a distance of 1 m by a metal halide lamp of 3 kw for 50 seconds, and then a molar ratio of SiO ₂ / Na ₂ O was changed. Development was carried out with a 5.26% aqueous solution of sodium silicate (pH = 12.7) having a ratio of 1.74.

After developing in this way, the product was thoroughly washed with water, gummed, and then printed by a conventional procedure. Table 1 shows the results of examining the contamination and printing durability of the non-image area at this time.

From the results in Table 1, it can be seen that the support according to the present invention is more satisfactory in both the printing durability and the stain on the non-image area than those of the comparative examples.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-232998 (JP, A) JP-A-61-230990 (JP, A) JP-B-46-35685 (JP, B1)

Claims (2)

[Claims] 1. A hydrophilic layer containing an organic phosphonic acid having a carboxyl group or a hydroxyl group in a hydrocarbon group and having a molecular weight of 1,000 or less or a salt thereof is provided on the aluminum plate having an anodized film. A support for a lithographic printing plate. 2. The lithographic printing plate support according to claim 1, wherein the hydrophilic layer has a coverage of 1 to 100 mg to m ² .