JPH062434B2 - 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 an electrolytic method. It was subjected to a surface-roughening treatment such as an electro-chemical method such as the grain method or a method combining both methods, the surface was made satin-finished, then etched with an aqueous solution of acid or alkali, and further anodized. After that, if desired, a hydrophilic treatment is applied to obtain a lithographic printing plate support, and a photosensitive layer is provided on the support to obtain a PS 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. A method of providing a hydrophilic cellulose subbing layer containing an aqueous metal salt, as described, or GB2098627.
There is proposed a method of providing an undercoat layer of sodium arylsulfonate as described in Japanese Patent Laid-Open Publication No. 2003-242242, which prevents the above-mentioned non-image area from being contaminated and prevents the printed matter from being "dirted". However, the printing durability of the printed matter is 3 when the above treatment is not applied.
There was a drawback with the new problem of reduction to 0-80%.

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, a method of providing a thin layer of trihydroxybenzolcarboxylic acid as described in JP-B-44-6410 on the surface of an anodized aluminum support, or JP-B-41-14337. A method of providing a thin layer of meritic acid as described in JP-B No. 38-8907, or a method of providing a thin layer of phosphonic acid and its derivative as described in JP-B-38-8907 has been proposed. As a result, although the above-mentioned adhesion of the image area could be improved, on the other hand, there was a new problem that the stain on the non-image area was significantly deteriorated as compared with the case where the above treatment was not performed. In particular, such a problem became remarkable as the time from the production of the PS plate to the use thereof became longer.

[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]

As a result of intensive studies to achieve the above-mentioned object, the inventors of the present invention have achieved the present invention. The present invention provides at least one amino group on an aluminum plate having an anodized film. A hydrophilic layer containing a group and at least one selected from the group consisting of an inorganic acid salt and an organic acid salt of a compound having at least one group selected from a carboxyl group and a sulfo group. It is a support for a lithographic printing plate.

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 aluminum suitable for the present invention is pure aluminum, but completely pure aluminum is difficult to produce due to the kneading technique, and therefore it is preferable that it contains no foreign atoms as much 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 surface-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
0A / dm ^2, is suitably selected from the range of the voltage 1~100V electrolysis time of 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 (1) at least 1
Amino groups (including primary amino groups, secondary amino groups and tertiary amino groups), (2) at least one group selected from the group consisting of a carboxyl group and a sulfo group, and further if necessary. (3) Inorganic acid salts and organic acid salts of compounds having a hydrophilic group other than the above (1) and (2) are included. The inorganic acid salt is preferably a hydrochloride or a phosphate, and the organic acid salt is preferably an oxalate or a formate.

The compound having at least one amino group and a carboxyl group and / or a sulfo group has a molecular weight of 10
Compounds of not more than 00 are suitable, and specifically, amino acids such as aminoacetic acid, lysine, threonine, serine, aspartic acid, parahydroxyphenylglycine, dihydroxyethylglycine, anthranilic acid, tryptophan, and arginine; sulfamic acid, cyclohexylsulfamic acid. And the like, such as aliphatic amino sulfonic acids, and the like, and hydrochlorides, oxalates, phosphates, and formates of these compounds are preferably used. Among them, lysine / hydrochloride, lysine / formate and arginine / hydrochloride are particularly preferable.

The above-mentioned hydrophilic compounds can be used alone or in combination of two or more kinds, and further, a compound having an amino group and a hydroxyl group as described in JP-A-60-202998 (for example, tri compound). It can also be used in combination with (ethanolamine, hydrochloride, etc.).

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 becomes less, while 100 mg / m ²
As the amount increases, the adhesion between the photosensitive layer and the support deteriorates, making it impossible to obtain a lithographic printing plate having low printing durability.

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 esters of 1,2-diazidosulfonic acid chloride with polyhydroxyphenyl or esters of naphthoquinone-1,2-diazidosulfonic acid chloride with pyrogal-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, 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
Oil-soluble dyes such as Blue F4R (above manufactured by BASF), Oil-Blue # 603, Oil Blue BOS, Oil Blue IIN (above manufactured by Orient Chemical Industry) are listed. To be

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.

As the photolytic acid generator, 1,2-naphthoquinone azide- (2) -4-sulfonic acid chloride and 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.

As a negative-working photosensitive diazo compound, US Pat.
Nos. 6,363,1 and 2,667,415, and a diphenylamine-p-diazonium salt and a form which are reaction products of a diazonium salt and an organic condensing agent containing a reactive carbonyl group such as aldol and acetal. A condensation product with an aldehyde (so-called photosensitive diazo resin) is preferably used. Other useful fused diazo compounds are disclosed in U.S. Pat. No. 3,679,419, British Patent Nos. 1312925 and 1312926, and the like. These types of photosensitive diazo compounds are
It is usually obtained in the form of water-soluble inorganic salts and can therefore be applied from aqueous solutions. Also, these aqueous 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. 1280885, It is also possible to use a substantially water-insoluble photosensitive diazo resin which is a reaction product.

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,
Copolymers containing methacrylic acid, crotonic acid or maleic acid as essential polymerization components, for example US Pat. No. 4,123.
2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate as described in No. 276,
Tertiary or quaternary copolymers with acrylonitrile or methacrylonitrile, acrylic acid or methacrylic acid and optionally other copolymerizable monomers, such as those described in JP-A-53-120903. Is a hydroxy group and is esterified with a group containing a dicarboxylic acid ester residue, a copolymer of acrylic acid or methacrylic acid, acrylic acid or methacrylic acid, and optionally other copolymerizable monomer. , A monomer having an aromatic hydroxyl group at the terminal (such as N- (4-hydroxyphenyl) methacrylamide) as described in JP-A-54-98614, acrylic acid or methacrylic acid, and further necessary. A copolymer with at least one of the other copolymerizable monomers according to JP-A-56-
Included are copolymers of alkyl acrylates or methacrylates, acrylonitrile or methacrylonitrile, and unsaturated carboxylic acids, as described in US Pat. Acid polyvinyl alcohol derivative,
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 difunctional glycols (for example, US Pat. Nos. 2,956,878 and 3,173).
Photosensitive polymers as described in US Pat. No. 787); cinnamic acid esters of hydroxyl-containing polymers such as polyvinyl alcohol, starch, cellulose and the like (eg US Pat. No. 2,690,966). , Ibid. 275
2372, No. 2732301, etc., and photosensitive polymers as described in the respective specifications) and the like. 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.

[Effect of the present invention]

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. At this time, the surface roughness (center line average roughness) is 0.
It was 5μ. After washing with water, add 70% of 10% caustic soda solution.
It was dipped in a solution warmed to 0 ° C. and etched so that the amount of aluminum dissolved was 6 g / m ² . 30% after washing with water
It was immersed in a nitric acid aqueous solution for 1 minute for neutralization, and then thoroughly washed with water. After that, in a 0.7% aqueous nitric acid solution, an alternating voltage of 13 V for the anode and a voltage of 6 V for the cathode was used (see the power supply waveform described in the embodiment of JP-A-52-77702). ) Electrolytic surface roughening is performed for 20 seconds, and 50% of 20% sulfuric acid is used.
The surface was washed by immersing it in a solution at ℃ and then washed with water.

70 g / sulfuric acid aqueous solution (Al ion concentration 7 g /
), The anodized film is anodized with a direct current to a weight of 3.0 g / m ² , washed with water, dried, and then the substrate
Prepared (I).

The solution of the following composition on the surface of the substrate (I) treated in this way
(A) was applied 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.

A solution having the following composition was applied to the substrate (I) using lysine / formate 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, a solution having the following composition was applied to the substrate (I) using arginine / hydrochloride, and dried at 80 ° C. for 30 seconds. The coating amount was 10 mg / m ² after drying.

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

For comparison, carboxymethyl cellulose (molecular weight 25,000) or polyvinyl alcohol (molecular weight 100)
00) is dissolved in water and the coating amount after drying is 10 mg.
/ M ² on the substrate (I) so that the substrate (V),
A substrate (VI) is provided.

Substrates (I) to (VI) thus prepared were provided with a photosensitive layer so that the coating weight of the dry V 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 with a metal halide lamp of 3 kw for 50 seconds, and then a mole of Sio ₂ / Na ₂ O was added. 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.

Example 4 As in Example 1, except that lysine in solution (A)
Substrate (VII) was prepared using the same amount of sulfamic acid / hydrochloride instead of hydrochloride.

Using this substrate (VII), a photosensitive lithographic printing plate was manufactured in the same manner as in Example 1, and the contamination of the non-image area and the printing durability were examined in the same manner as in Example 1.

The printing durability was 150,000 sheets, and the stains on the non-image area were at a level of ◯, indicating good performance.

Claims (3)

[Claims] 1. An inorganic acid salt and an organic acid salt of a compound having at least one amino group and at least one group selected from a carboxyl group and a sulfo group on the aluminum plate having an anodized film. A support for a lithographic printing plate comprising a hydrophilic layer comprising at least one selected from the group consisting of: 2. The lithographic printing plate support according to claim 1, wherein the compound has a molecular weight of 1,000 or less. 3. The lithographic printing plate support according to claim 1, wherein the hydrophilic layer has a coverage of 1 to 100 mg / m ² .