JPS6233692A - Substrate for lithography - Google Patents

Abstract

PURPOSE:To enhance a adhesion between a photosensitive layer and a substrate and a printing durability and to prevent contamination in a non-image portion, by providing a hydrophilic layer including a water soluble epoxy compound containing one or more epoxy group(s) on an anodized film produced on an aluminum sheet. CONSTITUTION:A water soluble epoxy compound is obtained by a method wherein an ethylene oxide or an ethylene oxide having substituent such as 2-hydroxyethyl, carboxymethyl, and sulfo is polymerized and an epichlorohydrin is reacted with the hydroxyl groups positioned at the top ends in the molecular structure of the obtained polymer. An aluminum sheet has not more than 10wt% in content of atoms other than those of aluminum and is 0.1-0.5mm in thickness. The aluminum sheet is grained to have a roughened surface and thereafter anodized to obtain thereon an anodized film ranging 1-6g/m<2> in amount. On the anodized film, the solution of the epoxy compound in an organic solvent or water is coated and dried to form a hydrophilic layer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a support for lithographic printing plates, and particularly to a support for lithographic printing plates provided with an undercoat layer that improves the adhesion between the photosensitive layer and the support. It is related to the support.

[Prior Art] Conventionally, lithographic printing plates are so-called PS plates (photosensitive lithographic printing plates) in which a photosensitive composition is coated in a thin layer on an aluminum plate.
However, the above-mentioned aluminum plate is usually subjected to surface roughening treatment such as a mechanical method such as a brush gray method or a boulderaine method, an electrochemical method such as an electrolytic method, or a method that combines both. After the surface is made into a matte finish, it is etched with an aqueous solution of acid or alkali, and then subjected to anodizing treatment, and then subjected to a hydrophilic treatment if desired to form a support for a lithographic printing plate. A photosensitive layer is provided on the plate to form a PS plate. This PS plate is usually subjected to image exposure, development, correction, and gumming processes to form a lithographic printing plate, which is attached to a printing machine and printed.

However, in the above lithographic printing plate, the positive-acting P
Substances contained in the photosensitive layer are irreversibly adsorbed 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 have been problems in which it is difficult to identify non-image areas, and traces of correction remain clearly, resulting in an uneven plate surface, and if the degree of this becomes severe, it becomes smudged, making it impossible to use it as a printing plate.

In order to improve this, conventional methods include immersing the anodized aluminum support surface in an alkali metal silicate as described in U.S. Pat. No. 3,181,461; 860.426, or British Patent No. 2.098.6.
By applying a treatment such as undercoating with sodium arylsulfonate as described in Publication No. 27, it is possible to prevent the above-mentioned contamination of the non-image area and prevent the occurrence of "stains" on printed matter. However, on the other hand, the printing durability of printed matter is 50-80% of that without the above treatment.
There was a drawback that came with a new problem: a decrease in

In addition, in the case of a negative-working PS plate, the adhesion of the image area of the lithographic printing plate obtained by image exposure and development to the support is reduced;
There was a problem in that it could not be used in applications where a large number of sheets were to be printed. In order to improve this problem, the conventional method is to provide a thin layer of trihydroxypenzole carboxylic acid on the surface of an anodized aluminum support, as described in Japanese Patent Publication No. 44-6410, or Japanese Patent Publication No. 38-1989. 89
Attempts have been made to improve the adhesion of the above-mentioned image area by applying treatments such as forming a thin layer of phosphonic acid and its derivatives as described in Publication No. 07, but on the other hand, the A new problem has arisen in that the stain in the image area is significantly worse than in the case where the above treatment is not performed.

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

In this way, it has traditionally been the case that lithographic printing plates with high printing durability are prone to staining in non-image areas, and conversely, lithographic printing plates that are hard to stain in non-image areas have low printing durability. It was believed that it would be extremely difficult to make improvements at the same time.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a lithographic printing plate that improves the adhesion between the photosensitive layer and the support, has excellent printing durability, and does not cause contamination in non-image areas (a lithographic printing plate that can be lifted up). It is to provide support.

[Structure of the invention]

The present inventors have made extensive studies to achieve the above object, and as a result, have completed the present invention.

The present invention is a support for a lithographic printing plate, characterized in that a hydrophilic layer containing a water-soluble epoxy compound containing at least one epoxy group is provided on an aluminum plate having an anodized film. . A preferred epoxy compound used in the present invention is represented by the following general formula.

In the formula, R1, R2, R3 and R4 are each independently a hydrogen atom, -01-1, -C2H,OHl-CI-12c
OOM, -3○3M or -COOM (M represents a hydrogen atom or an alkali metal), and n is 1 to 50, preferably 3 to 9.

When n is larger than 50, the effect of improving the adhesive force between the photosensitive layer and the support tends to be reduced. The molecular weight of the epoxy compound used in the present invention is suitably 10.000 or less. If the molecular weight exceeds 0.000, the effect of improving the adhesive force between the photosensitive layer and the support tends to be reduced.

Preferred water-soluble epoxy compounds include the following.

CH2C11,OH 03Na CH□C0OH Directly, the water-soluble epoxy compound used in the present invention is obtained by polymerizing ethylene oxide or ethylene oxide having a substituent such as a 2-hydroxyethyl group, a carboxymethyl group, or a sulfo group according to a conventional method. This can be achieved by reacting the hydroxyl groups at both ends with epichlorohydrin.

Commercially available water-soluble epoxy compounds include Eponit 012Δ (manufactured by Nitto Kasei CI Kikusha) (see (1) above).
), etc.

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

The aluminum plate used in the present invention is 7 Jl
/ It is a plate-shaped body made of pure aluminum whose main component is minilum or an aluminum alloy containing a small amount of foreign 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 aluminum, but since it is difficult to produce completely pure aluminum due to smelting technology, it is preferable to use aluminum that contains as few foreign atoms as possible. As described above, the composition of the aluminum plate applied to the present invention is not limited; conventionally known and publicly used materials can be used as appropriate. The thickness of the aluminum plate used in the present invention is approximately 0.1
Approximately m+r+-0.5 mm is appropriate. Prior to the graining treatment, in order to remove rolling oil from the surface of the aluminum plate, a degreasing treatment using a surfactant or an alkaline aqueous solution is performed, if desired. After that, on the above aluminum plate,
Grain treatment is performed.

Grain treatment methods include a method of mechanically chewing the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. As a method for roughening the surface, known methods such as ball polishing, brush polishing, blast polishing, huff 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, a method that combines both methods can also be used, as disclosed in Japanese Patent Application Laid-Open No. 54-63902.

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

The aluminum plate thus treated is subjected to anodizing treatment. As the electrolyte used in the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used, and the electrolyte and its concentration are determined as appropriate depending on the type of electrolyte. The processing conditions for anodic oxidation vary depending on the electrolyte used, so they cannot be definitively specified, but generally the electrolyte concentration is 1 to 80% by weight, and the solution temperature is 5%.
~70℃, current density 5~60A/dm2, voltage 1~10
0■, electrolysis time range of 10 seconds to 50 minutes is appropriate.

The amount of the anodic oxide film is preferably in the range of 0.1 to 10 g, 7 m2, and more preferably in the range of 1 to 6 g, 7 m2.

By applying a solution of the epoxy compound dissolved in water or an organic solvent onto the anodized film of the aluminum plate treated as described above and drying it to form a hydrophilic layer,
A support for a lithographic printing plate of the present invention is obtained.

It is appropriate that the concentration of the epoxy compound in the coating liquid is in the range of 0.001 to 10% by weight, the temperature is in the range of 10°C to 50°C, and the pH is in the range of 1 to 13.

As a method for applying the epoxy compound coating liquid, any method such as dip coating, spin coating, spray coating, curtain coating, etc. may be used.

The coating amount after dry smoke is preferably 1 to 100 mg/m'', more preferably 5 to 50 mg/m2.

As the above-mentioned coating amount becomes less than 1 mg 7 m2, the adhesion between the photosensitive layer and the support deteriorates;
As the amount exceeds g/m2, the adhesion deteriorates, the printing durability becomes low, and only lithographic printing plates with dirty non-image areas can be obtained.

The amount of coating containing a water-soluble epoxy compound includes an auxiliary agent for uniform coating, such as a polymer containing one unit of a monomer having a sulfonic acid group as described in JP-A-59-101651, such as p - Styrene sulfonic acid copolymers, vinyl sulfonic acid copolymers, etc. may be included.

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

On the lithographic printing plate support obtained in this way,
A photosensitive lithographic printing plate can be obtained by providing a conventionally known photosensitive layer, and the 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 solubility or swelling property in a developer changes before and after exposure. The typical ones will be explained below.

(1) Photosensitive composition consisting of diazo resin and binder As a negative-acting photosensitive diazo compound, US Pat.
Diphenylamine, which is a reaction product of the diazonium salt disclosed in No. 063.631 and No. 2.667 and No. 415, and an organic condensing agent containing a reactive carbonyl group such as aldol or acecool. A condensation product of p-diazonium salt and formaldehyde (so-called photosensitive diazo resin) is preferably used. Other useful condensed diazo compounds are Japanese Patent Publication No. 49-48001, No. 4
It is disclosed in each publication such as No. 9-45322 and No. 49-45323. These types of photosensitive diazo compounds are
They are usually in the form of water-soluble inorganic salts and can therefore be applied from an aqueous solution. Further, 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 Japanese Patent Publication No. 47-1167, The reaction product, a substantially water-insoluble photosensitive diazo resin, can also be used.

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

In addition, diazo resins described in US Pat. No. 1,312,925 are also preferred.

Such diazo resins are used together with binders. Preferred binders are organic polymers having an acid value of 10 to 200, and specific examples include copolymers containing acrylic acid, methacrylic acid, crotonic acid, or maleic acid as an essential polymerization component, such as U.S. Pat. .123
．． 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, acrylonitrile or methacrylonitrile, ternary or acrylic acid or methacrylic acid and optionally further copolymerizable monomers as described in No. 276. Quaternary copolymers, acrylic acid or methacrylic acid, acrylic acid or Copolymer of methacrylic acid and, if necessary, other copolymerizable monomers, JP-A-5
A monomer having an aromatic hydroxyl group at the end as described in No. 4-98614 (for example, N-(4-hydroxyphenyl) methacrylamide), acrylic acid or methacrylic acid, and further other materials as necessary. Copolymer with at least one copolymerizable monomer, JP-A-56-4
Copolymers of alkyl acrylates or methacrylates, acrylonitrile or methacrylonitrile, and unsaturated carboxylic acids as described in No. 144 are included. Also useful are acidic polyvinyl alcohol derivatives and acidic cellulose derivatives.

(2) A composition containing a compound that causes trimerization upon irradiation with actinic light.

For example, polyvinyl cinnamate, polyvinyl cinnamoyl ethyl ether, polyethyl cinnamate acrylate and its copolymers, polyethyl cinnamate methacrylate and its copolymers, polyparavinylphenyl cinnamate and sonocopolymers, polyvinyl benzal. Acetophenone 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, such as U.S. Pat. No. 3.030.208 There are compounds such as those described in the specification of No.

(3) A so-called photopolymerizable composition that causes a polymerization reaction upon irradiation with actinic light.

For example, U.S. Pat. No. 2.760.863 and U.S. Pat.
No. 060.023 discloses a composition comprising an addition polymerizable unsaturated compound having two or more terminal ethylene groups and a photopolymerization initiator.

The compound that trimerizes and the compound that undergoes a polymerization reaction upon irradiation with actinic rays 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 onto 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/m2 is suitable, about 0.5 to about 3.0 g
/m2 is more preferable.

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

〔Effect of the invention〕

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

〔Example〕

Hereinafter, the present invention will be explained in more detail using Examples. Note that "%" in the examples indicates "% by weight" unless otherwise specified.

Example 1 JIS1050 aluminum sheet with pamice water uPf
Using liquid A as an abrasive, the surface was sanded with a rotating nylon brush. At this time, the surface roughness (center line average roughness) is 0.
．． It was 5μ. After washing with water, add 10% caustic soda aqueous solution to
It was immersed in a solution heated to 0°C and etched so that the amount of dissolved aluminum surface was 6 g/m''. After washing with water, it was immersed in a 30% nitric acid aqueous solution for 1 minute to neutralize it, and then thoroughly washed with water. did.

After that, in a 0.7% nitric acid aqueous solution, using a square wave alternating waveform with an anode voltage of 13 volts and a cathode voltage of 6 volts (
Power supply waveform described in the example of JP-A-51-77702) Electrolytic surface treatment was carried out for 20 seconds, the surface was washed by immersion in a 20% sulfuric acid solution at 50°C, and then washed with water.

Furthermore, the weight of the anodic oxide film was 3.0 in a 20% sulfuric acid aqueous solution.
(2.5% silicic acid) after anodizing using direct current to give a concentration of 2.5% silicic acid (after washing with water and drying).
After immersion at 0° C. for 30 seconds, washing with water, and drying, a substrate (I) was prepared.

A solution (1) having the following composition was applied to the surface of the substrate (1) thus treated and dried at 80° C. for 30 seconds.

The coverage after drying was 20 mg/m'.

In this way, 4.1(II) was created.

In addition, instead of the water-soluble epoxy compound, carboxymethyl cellulose (molecules! 25,000), 1t polyvinyl alcohol (molecules ff 110,000), or polyvinylpyrrolidone (molecules ff 125,000) were dissolved in water, and the coating amount after drying was 1Qmg/m2 on the substrate (1), and the substrate (III),
(IV) and (V) were created.

A photosensitive layer was provided on the substrates (I) to (V) thus prepared by applying the following composition so that the coating weight after drying was 2.5 g/m2.

Photosensitive solution The photosensitive lithographic printing plate thus prepared was exposed to light for 2 seconds from a distance of 1 m using a 2KW metal halide lamp through a transparent negative film in a vacuum printing frame, and then developed with a developer having the following composition. Then, it was gummed with an aqueous gum arabic solution to prepare a lithographic printing plate.

5 g of liquid sodium carbonate was printed using the lithographic printing plate prepared in this way according to a conventional procedure. Table 1 shows the results of examining the staining of the non-image area and printing durability at this time.

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.

Procedural amendment written by the Commissioner of the Patent Office, Michibe Uga 1, Indication of the case Patent application No. 172722 of 1985
No. 2, Title of the invention Support for lithographic printing plates 3, Relationship to the amended case Applicant name (520) Fuji Photo Film Co., Ltd. 4, Agent address 3-3-1 Marunouchi, Chiyoda-ku, Tokyo Phone Number: 211-8741 Name (5995) Patent Attorney Minoru Nakamura 5,
Date of amendment order Vol. 6, subject of amendment Corrected as "10■/r/J" in the detailed explanation of the invention in the specification.

Claims (4)

[Claims] (1) A support for a lithographic printing plate, comprising an aluminum plate having an anodized film, and a hydrophilic layer containing a water-soluble epoxy compound containing at least one epoxy group provided on the film. (2) The support for a lithographic printing plate according to claim (1), wherein the epoxy compound is a compound represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1, R_2, R_3 and R_4 each independently represent a hydrogen atom, -OH, -C_2H_4OH, -CH
_2COOM, -SO_3M or -COOM (M represents a hydrogen atom or an alkali metal), n is 1 to 5
Indicates an integer of 0. (3) The support for a lithographic printing plate according to claim (1), wherein the epoxy compound has a molecular weight of 10,000 or less. (4) The support for a lithographic printing plate according to claim (1), wherein the coating amount of the hydrophilic layer is 1 to 100 mg/m^2.