JPS60232998A - Base for planographic plate - Google Patents

Abstract

PURPOSE:To ensure that image parts are firmly adhered to a base and non- image parts are hardly contaminated, by a construction wherein a hydrophilic layer comprising a compound having an amino group and a hydroxyl group or a salt thereof is provided on an anodic oxide film of an aluminum plate having the anodic oxide film. CONSTITUTION:A solution of a hydrophilic compound is applied to the anodic oxide film of the aluminum plate, and is dried to obtain the hydrophilic layer, thereby obtaining the base for a planographic plate. The hydrophilic compound consists of at least one selected from a compound having at least one amino group and at least one hydroxyl group and a salt thereof, and has a molecular weight of not higher than 1,000. Most preferred examples of the hydrophilic compound are triethanolamine and hydrochloride thereof. The amount of the solution applied is preferably 1-100mg/m<2> in dry weight. If the amount is less than 1mg/m<2>, non-image parts are easily contaminated, and on the other hand, if the amount is more than 100mg/m<2>, adhesion between a photosensitive layer and the base is deteriorated. Accordingly, a planographic plate using the base thus obtained has high durability in printing and the non-image parts thereof are hardly contaminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a support for a lithographic printing plate, and more particularly to a support for a lithographic printing plate comprising an anodized aluminum plate having an improved hydrophilic layer. It is something.

[Prior art]

Conventionally, there is a so-called 28 plate in which a photosensitive composition is coated in a thin layer on an aluminum plate as a lithographic printing plate, but the above aluminum plate is usually processed by a mechanical method such as a brush grain method or a pole grain method. The surface is roughened by an electrochemical method such as the electrolytic 1/in method or a combination of both methods, and the surface is made into a matte finish.Then, the surface is etched with an aqueous solution of acid or alkali, and then heated. After further anodizing, it is optionally subjected to a hydrophilic treatment to obtain a support for a lithographic printing plate, and a photosensitive layer is provided on this support to form a PS plate (lithographic printing plate).

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

However, in the above lithographic printing plate, the positive-acting P
Substances contained in the photosensitive layer irreversibly adsorb to the non-image areas of the lithographic printing plate obtained by imagewise exposure and development of the S plate, contaminating the non-image areas. There were problems in that it was difficult to identify the image area, and the plate surface was uniform in color with clear traces of correction, and if the degree of correction became severe, it became smeared and could no longer be used as a printing plate.

To improve this, conventionally, the surface of the aluminum support was anodized, as described in U.S. Patent No. 3. /l/.

4'A/, a method of immersion in alkali metal silicate, as described in US Pat. No. 3. Irt-0,ψ
2.09 method of hydrophilic cellulose containing water-soluble metal salts, as described in US Pat. No. 2.09
g, by applying a treatment such as undercoating with sodium arylsulfonate as described in Publication No. 627, to prevent the above-mentioned contamination of the non-image area and prevent the occurrence of "1 stain" on printed matter. However, on the other hand, the printing durability of printed matter is less than that of SO~・tO when the above treatment is not performed.
The shortcomings came with the new problem of decreasing the percentage.

In addition, in the case of a negative-acting PS plate, the adhesion of the image area of the lithographic printing plate obtained by image exposure and scratching to the support is reduced;
There was a problem that it could not be used for applications where a large number of sheets were to be printed.

In order to improve this problem, the conventional methods have been to apply a thin layer of trihydroxypenzole carboxylic acid on the surface of the anodized aluminum support as described in Japanese Patent Publication No. 741'10, or Kosho 4! /-1113
Treatments such as the method of providing a thin layer of mellitic acid as described in Japanese Patent Publication No. 37-1907, or the method of providing a thin layer of phosphonic acid and its derivatives as described in Japanese Patent Publication No. 31-1907. By applying this treatment, it was possible to improve the adhesion of the image area as described above, but on the other hand, a new problem occurred in that the staining of the non-image area was significantly worse than when the above treatment was not applied.

In particular, such problems became more noticeable as time passed after the PS plate was manufactured.

[Purpose of the invention]

An object of the present invention is to provide a support for a lithographic printing plate, which allows 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 stained.

[Structure of the invention]

The inventors of the present invention have made the present invention as a result of intensive studies to achieve the above object. Lithographic printing characterized in that a hydrophilic layer is provided, comprising a compound having at least one hydroxyl group (including groups, secondary amine groups, and tertiary amino groups), and at least one compound selected from that period. It is a support for the plate.

Hereinafter, the traps of the present invention will be explained in detail step by step.

The aluminum plate used in the present invention is a plate-shaped body made of pure aluminum containing aluminum as a main component or an aluminum alloy containing a trace amount of foreign atoms.

These foreign atoms include silicon, iron, manganese, copper, magnesium, chromium, zinc, hismuth, nickel, and titanium. The alloy composition has a content of at most 10% by weight or less. Aluminum suitable for the present invention is pure aluminum, but since completely pure aluminum is difficult to produce due to smelting technology, it is preferable to use aluminum that contains as few foreign atoms as possible. Furthermore, any aluminum alloy having the above-mentioned content can be said to be a material that can be applied to the present invention. As described above, the composition of the aluminum plate applied to the present invention is not specified; conventionally known and publicly used materials can be used as appropriate. The thickness of the aluminum plate used in the present invention is approximately 0.0 to 0.0 mm.
It takes about 5 minutes.

Prior to anodizing the aluminum plate, degreasing treatment, such as treatment with a surfactant or alkaline aqueous solution, and graining treatment are carried out, if desired, in order to remove rolling oil from the surface.

Graining treatment methods include a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. As a method for mechanically roughening the surface, a known method called a ball polishing method, a polishing method, a gelast polishing method, a puff polishing method, etc. can be used. Further, as an electrochemical surface roughening method, there is a method in which ii.

Furthermore, a method that combines both methods can also be used, as disclosed in Japanese Patent Application Laid-Open No. 63202/1993.

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

Sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used as an electrolyte for anodizing an aluminum plate, and the electrolyte and its concentration are appropriately determined depending on the type of electrolyte.

The treatment conditions for anodic oxidation vary depending on the electrolyte used, so it is difficult to specify them, but in general, the electrolyte concentration is
～・Za0% by weight solution, liquid temperature is j～706C1 current density 5
-AOA, /dTrL, mpressure/, 10O; Electrolysis time is suitable within the range of io seconds to SO minutes.

! The anodized film has 0. /~·'OCJ/m2 is suitable, but - is more preferably in the range of /~·6g/1rL2. On the anodic oxide film of the aluminum plate treated as described above (in water or an organic solvent such as methanol)
The support for a lithographic printing plate of the present invention can be obtained by applying a solution in which the hydrophilic compound described above is dissolved and drying to form a hydrophilic layer. The hydrophilic compound used in the present invention consists of at least one compound selected from compounds having at least /lil amino groups and at least one hydroxyl group, and salts thereof.

Such a hydrophilic compound is suitably a compound having a molecular weight of /,000 or less. As specific hydrophilic compounds, for example, 7/1 tanolamine, jetanolamine, trimethanolamine, tripropaturamine, triethanolamine, and their 1M salts, oxalates, and phosphates are useful.

Among these, triethanolamine and triethanolamine hydrochloride are most preferred.

The hydrophilic compounds as mentioned above can be prepared in a suitable solvent, such as water,
Alcohols such as methanonyl, o.

It is completely dissolved and used as a coating liquid at a concentration of 7 to 70% by weight. At this time, it is appropriate that the pH after coating is in the range of i, i3. Further, the temperature of the coating liquid is suitably in the range of lo-5o QC.

As the coating method, any method such as dip coating, spin coating, spray coating, curtain coating, etc. may be used. The coating amount is the coating amount after drying /=100 mti/m
is suitable, but more preferably j~jO■/m2
is within the range of As the above-mentioned amount of PJ becomes smaller than /immediate/rn2, the VC effect of preventing dirt in the non-image area disappears, and on the other hand, as the amount of PJ increases from /00 m9/7112, the confidentiality between the photosensitive layer and the support deteriorates. 12. Lithographic printing plates with low printing durability (-1 or less).

Before or after providing the hydrophilic layer, the anodized aluminum plate is coated as described in US Patent No. 3. iri.

It can be treated with aqueous solutions of alkali metal silicates (e.g. sodium silicate), as described in t/, No. 61.

On the support for the lithographic printing plate obtained in this way,
A photosensitive lithographic printing plate can be obtained by providing a conventionally known photosensitive layer as a photosensitive layer of a PS plate (abbreviation for Pre-8ensft1zed Plate), and a lithographic printing plate obtained by plate-making processing this plate. has excellent performance.

As the composition for the above-mentioned photosensitive layer, any composition can be used as long as its f4 resolution or swelling property with respect to a developer changes before and after exposure. The typical ones will be explained below.

■ As a positive-acting photosensitive diazo compound, Tokuko Shoφ
J-21 (ester of penzoginone-1.+2-diazide sulfonic acid chloride and polyhydroxyphenyl described in Publication No. 103 or Su7toquino7-/, J-
Most preferred are esters of diazide sulfonic acid chloride and pyrocalol-acetone resin. Other relatively suitable 0-quinonediazide compounds include U.S. Pat. /II, 21
Benzoquinone-1 described in each specification of No. 0,
Codiazide sulfonic acid chloride or naphthoquinone-1
There is one stellation of 6,2-diazide sulfonic acid chloride and phenol formaldehyde resin.

The 0-quinonediazide compound may be used alone to form the photosensitive layer, or may be used together with this type of resin using an alkaline water-soluble resin as a binder (.9 inter).

Examples of resins soluble in alkaline water include novolac resins having this property, such as phenol formaldehyde resin, cresol formaldehyde resin,
-t-tylphenol-formaldehyde resin,
These include phenol-modified xylene resin, phenol-modified xylene/mesitylene resin, etc. Other useful alkaline water-soluble resins include polyhydroxystyrene, copolymers of polyhalokenated hydroxystyrenated (meth)acrylic acid and other vinyl compounds.

Further details of the photosensitive layer consisting of an 0-quinonediazide compound and its developer can be found in US Patent No. μ, 2! This is detailed in the ψ3-hiro issue.

1 ■ A photosensitive composition comprising a diazo resin and a binder.

As a negative-acting photosensitive diazo compound, US special 'III
diphenylamine, which is a reaction product of a diazonium salt disclosed in each specification of the No.
A condensation product of p-diazonium salt and formaldehyde (so-called photosensitive diazo resin) is preferably used. Other useful fused diazo compounds are described in U.S. Pat. No. 3,672.
≠No.1, British Patent No. 1,3/2. ri 2 evening issue, same l.

It is disclosed in each specification etc. of 3/Co and 2B.

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. Moreover, these water-soluble diazo compounds are disclosed in British Patent Nos. I and 2.
to, err, with an aromatic or aliphatic compound having one or more phenolic hydroxyl groups, sulfonic acid groups, or both, and the reaction product is substantially water. It is also possible to use insoluble photosensitive diazo resins.

Also, Tokukai Akira! It can also be used as a reaction product with hexafluorophosphate or tetrafluoroborate as described in No. 6-1, No. 1031.

In addition, diazo resins described in US Pat. No. 1,3/-2, Tarr 2j are also preferred.

Such diazo resins are used together with binders. Preferred binders are organic polymers having an acid value of 10-20゛ Ot, such as copolymers containing acrylic acid, methacrylic acid, chloroacid or maleic acid as an essential polymeric component, such as U.S. Pat. No. ≠, /
co-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, acrylonitrile or fc hamethacrylonitrile, as described in No. 23,276;
A ternary or μ-element copolymer of acrylic acid or methacrylic acid and, if necessary, other copolymerizable monomers, with hydroxyl terminals as described in JP-A No. 1983/03. acrylic acid or methacrylic acid esterified with a group containing a dicarboxylic acid ester residue; a copolymer of acrylic acid or methacrylic acid and optionally 67' further copolymerizable monomers; ,
Monomers having an aromatic hydroxyl group at the end (for example, N-(F-hydroxy]1-nyl) methacrylamide) as described in JP-A No. 4/4', acrylic acid or copolymers with methacrylic acid and, if necessary, at least one other copolymerizable monomer, alkyl acrylates or methacrylates, acrylonitrile or Includes copolymers of methacrylate tolyl and unsaturated carbonic acids. Also useful are acidic polyvinyl alcohol derivatives and acidic cellulose fat conductors.

■ A composition containing a compound that forms a dimer upon irradiation with actinic rays. For example, polyvinyl cinnamate, polyhinyl cinnamoyl ethyl ether, polyethylene cinnamate acrylate and its copolymer, polyethyl cinnamate methacrylate and its copolymer, poly/nirahinyl phenyl cinnamate and its copolymer. , polyhinylbenzalacetophone and its derivatives, polyvinylcinnamylidene acetate and its derivatives, allyl acrylate prepolymer and its derivatives, derivatives of polyester resins consisting of paraphenylene diacrylic acid and polyhydric alcohol, For example, U.S. Patent No. 3,030. Examples include compounds such as those described in the specification of No.

■ So-called photopolymerizable compositions that undergo a polymerization reaction upon irradiation with actinic rays. For example, U.S. Patent No. 2,760.1163
No. 3.07, 0.023? There is a composition comprising an addition-polymerizable unsaturated compound having a terminal ethyl-1/one group of 2WA or more and a photopolymerization initiator as described in RJJ.

The compound that becomes two-component and the compound that undergoes a polymerization reaction upon irradiation with actinic rays include resins such as pa-inter,
It may contain a sensitizer, a thermal polymerization inhibitor, a dye, a plasticizer, etc.

7 The above photosensitive composition usually contains water, an organic solvent,
Alternatively, a solution of these mixtures is coated on a support according to the invention and dried to produce a photosensitive lithographic printing plate.

The four weights of the photosensitive composition generally range from about o, i to about 1
,09/@2 is suitable, and about O1j to about 3.097m
2 is more preferred.

The photosensitive lithographic printing plate thus obtained is imagewise exposed using a light source containing actinic rays such as a carbon arc lamp, xenon lamp, mercury lamp, tungsten lamp, metal halide lamp, etc., and developed to obtain a lithographic printing plate.

〔Effect of the invention〕

A lithographic printing plate using an aluminum support obtained according to the present invention has a remarkable effect that it has higher printing durability than conventional plates and at the same time, non-image areas are less likely to be stained. Conventionally, lithographic printing plates with high printing durability tend to stain in non-image areas, and conversely, lithographic printing plates with less staining in non-image areas have low printing durability, so it is possible to improve both of these properties at the same time. This was considered extremely difficult.

However, the lithographic printing plate using the aluminum support according to the present invention has excellent properties not previously available, such as high printing durability and resistance to staining of non-image areas.

〔Example〕

Below, the present invention will be explained in more detail using Examples. It should be noted that "%" in the examples indicates "% by weight" to the maximum extent specified.

Example I JIS1010 aluminum sheet? The surface was sanded with a rotating nylon 7 brush using a misu water suspension as an abrasive. At this time, the surface roughness (center line average roughness) is O0
It was jμ. After washing with water, i.

The sample was etched by immersing it in a caustic soda aqueous solution heated to 700C so that the amount of aluminum dissolved was 49/m 2 . After washing with water, it was immersed in a 30% nitric acid water bath solution for 1 minute to neutralize it, and then thoroughly washed with water.

After that, in a 0.7% nitric acid aqueous solution, using a rectangular wave alternating waveform with an anode special voltage of 13 volts and a cathode special voltage t port (
The power supply waveform described in the example of Japanese Patent Application Laid-Open No. 77702) was subjected to electrolytic surface treatment for 20 seconds, and the surface was washed by immersing it in a j+00c solution of -20 sulfuric acid, followed by washing with water.

Furthermore, the weight of the anodized film in -0% sulfuric acid aqueous solution was 3.0.
The substrate (I) was prepared by anodizing using a direct current so that the thickness of the substrate was 0.07 m, followed by washing with water and drying.

A solution (Il) having the following composition was applied to the surface of the substrate (I) thus treated and dried at 10'C for 30 seconds.

The coverage after drying was io~/m2.

In this way, a substrate (b) was created.

Further, a solution having the following composition was applied to a substrate (Il) using triethanolamine hydrochloride instead of triethanolamine, and dried at 10'C for 30 seconds.

The coverage was 10 to 2 after drying.

In this way, a substrate (ml) was prepared.

Furthermore, for comparison, carboxymethyl cellulose (molecular weight λs, ooo) or polyvinyl alcohol (molecular weight 10.00.0) was dissolved in water and coated on the substrate (■) so that the coating amount after drying was 10 da/1 r L2. A substrate (■) and a substrate (V) were respectively provided on top.

The coating weight after drying of the following composition on the substrates (T) to (V) thus prepared was 2-'! A photosensitive layer was provided so that the ratio was i'/m2.

/ The photosensitive lithographic printing plate made in this way was passed through a transparent positive film in a vacuum printing frame from a distance of 1 TrL using a JKW metal halide lamp! After θ seconds, the molar ratio of 5i02/Na2O is 1,
1.24% aqueous solution (p) of sodium silicate of 711 (=
/1.7).

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

did.

From the results in Table 1, it can be seen that the supports according to the present invention are more satisfactory in both printing durability and staining in non-image areas than those of the comparative examples.

Table 7 ○・・・Even if you squeeze out the amount of dampening water, there is no stain at all.

×: Staining occurs when the amount of dampening water is reduced.

Claims (3)

[Claims] (1) A hydrophilic layer made of a compound selected from compounds having at least one amine group and at least /@ hydroxyl groups, and salts thereof, is provided on the coating of an aluminum plate having an anodized coating. A support for lithographic printing plates. (2) The support for a lithographic printing plate according to claim 1, wherein the compound has a molecular weight of 1000 or less. (3) The amount of coverage of the hydrophilic layer is /-/001n9/y
A support for a lithographic printing plate according to claim 1, which is characterized in that: