JPS59220396A - Aluminum alloy plate for base for planographic printing plate and said base - Google Patents

Abstract

PURPOSE:To provide the title aluminum alloy plate capable of being speedily provided with bits distributed in a uniformly crowded condition through a chemical etching treatment, consisting of an Al alloy containing specified amounts of Fe, Mg and Sn or the like. CONSTITUTION:The aluminum alloy plate for a base for a planographic printing plate contians (A) 0.2-1wt% of Fe, (B) 0.1-0.6wt% of Mg, (C) 0.005-0.1wt% of at least one of Sn, In, Ga and Zn, and , if required, (D) 0.1-2wt% of Cu. The alloy plate is surface-roughened by chemical etching using an acid or an alkali to obtain the base for the planographic printing plate (preferably, followed by an electrochemical sanding treatment).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support for a lithographic printing plate, particularly an aluminum alloy plate for a lithographic printing plate support.

Generally, when an aluminum plate is used as a printing plate support, its surface is usually roughened in order to improve the adhesion between the photosensitive film and the aluminum plate and to improve water retention in non-image areas. It is. This surface roughening treatment is
Mechanical graining (so-called graining) such as boulder graining and sandblast brush graining, electrochemical graining (also called electrolytic polishing), and chemical etching known as chemical graining are known.

Each of these conventional graining methods has advantages and disadvantages. Generally, mechanical graining methods have problems such as scratches, dirt, and residual abrasives. Although the electrochemical graining method can change the grain depth shape to some extent by changing the amount of electricity, it generally requires a large amount of electricity and is expensive ( It has the disadvantage of being time consuming.

On the other hand, chemical dulling grains aluminum and aluminum alloys through a chemical etching reaction using an acid or alkali etchant, so the process is simple and suitable for continuous strip treatment, especially for double-sided treatment. It is industrially advantageous for making printed plates. However, it has been difficult to manufacture high-quality printing plates using commercially available aluminum or its alloys. The surface roughness and uniform pit pattern (the diameter of the etching pits are uniform and the depth of the peaks and valleys are uniform) are required to satisfy the sufficient printing durability and stain resistance required for printing plates. ) is difficult to prepare using conventional chemical etching methods. According to experiments conducted by the present inventors, commercially available aluminum and aluminum alloy materials JIS1
050°1100 and 3003 material were chemically etched with various etchants, resulting in a practical surface roughness of 0.3 to 1.2 μR, which is preferable for printing plates.
It is difficult to obtain α (center line average roughness), and even if the equivalent roughness is obtained, the reaction rate is slow and processing takes time, or the etchant contains components harmful to the human body, making it difficult to work. Various problems have been experienced, such as problems or high etching costs making it unsuitable for practical use.

The present invention relates to an aluminum alloy plate for a lithographic printing plate support that can improve these drawbacks, and a lithographic printing plate support using the same. The aluminum alloy plate of the present invention exhibits an excellent dissolution rate when subjected to chemical etching treatment, and contains an intermetallic compound that promotes uniform pit formation. It is possible to form pits that are densely distributed.

That is, the present invention has Ftt of 0.20 to 1.0 (weight).
2nd staff, M! I 0.10-0.6%>, and E3n,
In, Cra.

and Zn in an amount of 0.005 to 0.1%, or further contains Ow in an amount of 0.1 to 2%, and the same. This is the lithographic printing plate support used.

The alloy composition based on the present invention will be explained below.

In order to increase the dissolution rate of aluminum, it is desirable first to make the local cathode area as large as possible and second to make the local anode as base as possible. For the first purpose, it is better to mix a large amount of impurities, and Fg is 0.2
0-1.0%, more preferably further Gtb 0.1-2
It is effective to add %. If Fg and Gu are increased more than this, the anode area will become smaller and the etching pit pattern will become non-uniform. Furthermore, since it is difficult to form an anodic oxide film on impurities, there are many film defects, and as a result, scumming occurs during printing. Alloys containing Fe and CjtL have a high dissolution rate in both acids and alkalis, so
An appropriate solution can be selected depending on the desired etching amount and pit pattern.

Addition of elements selected from StL, Il, Cα and Zf& makes the matrix electrochemically less noble and can increase the rate of dissolution by etching. It is used for etching of letterpress printing plates. In the case of letterpress printing, a pattern with a depth of several squares is required, but in the case of planography, the depth is at most several microns.

In other words, the pit pattern must be fine and smooth.

Fg, Cju alloy with Sn, In, etc. as mentioned above.
It was surprisingly found that when small amounts of Ga and Zn elements were added, although the dissolution rate did not change much, the pit pattern became extremely fine. Here, the amount added is 0
．． If it is more than 0.1%, the solid solubility limit is far exceeded, especially for Sn, In, and Ga, so local dissolution becomes severe and it becomes difficult to obtain uniform pits and two turns.

Minimizing the amount of molten aluminum required to obtain the desired surface roughness reduces the load on waste liquid treatment equipment, and also reduces material costs by reducing the thickness of the aluminum plate to be treated. This is extremely important.

For this purpose, even more M! It is effective to add 0.1 to 0.3% of I. Although the behavior of Mf is not clear, it is thought that because surface dissolution is suppressed and the pits advance deeper, the desired surface roughness can be obtained with a small amount of dissolution.

The lithographic printing plate support of the present invention can be produced by roughening the surface of the aluminum alloy plate of the present invention described above with acid or alkali.

When chemically etching the aluminum alloy plate of the present invention with acid or alkali, the acid used may be one or a mixed solution of two or three of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, and the like. As the alkali, sodium hydroxide, sodium carbonate, trisodium phosphate, sodium silicate, etc. are used. The concentration and temperature are determined depending on the required surface roughness over time, but usually 1 to 50q.
b concentration, about 10 seconds to 4 minutes at room temperature to 90C. If there is contamination such as rolling oil, degreasing treatment is performed prior to chemical etching. After etching, pickling is performed to remove any dirt (smut) remaining on the surface. The acids used are nitric acid and sulfuric acid, and hydrogen peroxide is added to accelerate the reaction.

Furthermore, in the present invention, electrochemical graining is carried out in which the above-mentioned surface is grained by flowing a direct current or an alternating current in an electrolytic solution of one or more mixed solutions of hydrochloric acid or its salts, nitric acid or its salts, etc. It can also be applied.

The aluminum alloy plate treated as described above can be used as a lithographic printing plate support as it is, but it can be further provided with an anodized film and used as a high quality lithographic printing plate support.

For the anodic oxidation treatment, methods conventionally used in this field can be used. Specifically, an anodic oxide film can be formed on the surface of an aluminum support by passing a direct or alternating current through aluminum in an aqueous solution of sulfuric acid, phosphoric acid, oxalic acid, or a combination of two or more of these.

The processing conditions for anodic oxidation depend on the electrolyte used.
Although it cannot be determined unambiguously because it varies in various ways, in general, the concentration of the electrolytic solution is 1 to 80% by weight, and the liquid temperature is 5 to 70% by weight.
C1 current density 0.5-60 ampere/m2, voltage 1-1
A range of 00v1 electrolysis time of 10 to 100 seconds is appropriate.

Among these anodic oxide films, especially British Patent Nos. 1 and 4
No. 12,768, the method of anodizing at high current density in sulfuric acid, and the method of electrolytic phosphoric acid oxidation described in U.S. Pat. No. 3,511,661. A method of anodizing as a liquid is preferred.

The anodized aluminum plate is further described in U.S. Pat.
No. 714,066 and No. 3,181,461, by immersion in an aqueous solution of an alkali metal silicate, such as sodium silicate, or as described in U.S. Pat. As described in No. 426, an underlayer of hydrophilic cellulose (e.g. Eva, carboxymethylcellulose nato) containing a water-soluble metal salt (e.g. zinc acetate) can also be provided.

A conventionally known photosensitive layer can be provided on the lithographic printing plate support according to the present invention to obtain a photosensitive lithographic printing plate. It has excellent performance.

The composition of the above-mentioned photosensitive layer includes the following.

■ Photosensitive layer consisting of diazo resin and binder U.S. Pat.
Publication No. 49-45323, British Patent Nos. 1 and 3
Diazo resins described in British Patent No. 12,925 and British Patent No. 1,023,589 are preferred;
978, U.S. Patent No. 4,123,276, U.S. Patent No. 3,751,257, U.S. Patent No. 3,660,097
Preferred are the binders described in each specification of No. 1 and Japanese Patent Application Laid-open No. 54-98614.

(2) Photosensitive layer consisting of an 0-quinonediazide compound A particularly preferred O-quinonediazide compound is an 0-naphthoquinonediazide compound, for example, U.S. Pat. No. 2,766,1
No. 18, No. 2.767,092, No. 2,772,
No. 972, No. 2,859,112, No. 2,907
, No. 665, No. 3,046,110, No. 3,04
No. 6,111, No. 3,046,115, No. 3,0
No. 46,118, No. 3,046,119, No. 3,
046,12.0, 3,046,121, 3,046,122, 3,046,123, 3,061,430, 3,102,809 issue,
It is described in numerous publications including the specifications of the same No. 3,106,465, the same No. 3,635,709, and the same No. 3,647,443, and these are preferably used. Can be done.

■ A: Photosensitive layer consisting of a compound and a polymer compound, for example, British Patent No. 1,235,281, British Patent No. 1.4
Specifications of No. 95,861 and JP-A No. 51-32331
In addition to the compositions comprising an azide compound and a water-soluble or alkali-soluble polymer compound described in JP-A No. 50-5102 and JP-A-51-36128, etc.
No. 0-84302.

Included are compositions comprising a polymer containing an azide group and a polymer compound as a binder, which are described in JP-A No. 50-84303 and JP-A No. 53-12984.

■Other photosensitive resin layers For example, polyester compounds disclosed in JP-A No. 52-96696, British Patent No. 1.112,277,
Polyvinyl cinnamate resins described in U.S. Patent No. 1,313,390, U.S. Patent No. 1.341,004, U.S. Pat.
The photopolymerizable photopolymer compositions described in the specifications of No. 27 and No. 4,072,528 are included.

The amount of photosensitive layer provided on the support is approximately 0.1 to 711
7 m'', preferably O in the range of 0°5 to 41 I/1n2 After imagewise exposing the photosensitive lithographic printing plate, a resin image is formed by processing including development by a conventional method. For example, in the case of a lithographic printing plate having the photosensitive layer made of a diazo resin and a binder, after image exposure, the unexposed portions of the photosensitive layer are removed by development to obtain a lithographic printing plate. In the case of a lithographic printing plate having
After the image exposure, the exposed portion is removed by developing with an alkaline aqueous solution to obtain a lithographic printing plate.

Hereinafter, the effects of the alloy plate for planographic printing plate supports according to the present invention will be explained in detail based on the following examples.

Example 1 The following 8sI aluminum alloy plate was manufactured, and 10% Na
A chemical dulling treatment was performed in OH at 60C for 1 minute, and the surface roughness and pit pattern were observed using a scanning electron microscope (SEM).

As shown in Table 2, alloys A1 to A5 containing Fe and My as main components all had rough surfaces with a surface roughness of R6 or higher and uniform pit diameters with opening diameters of 2 to 8 μm. Comparative Example 1, in which Mg was not added, had the same amount of molten aluminum as A4, but the surface roughness was only 0.34 μfia.

In Comparative Example 2, which had a small amount of Fg, the amount dissolved was small, and therefore the surface roughness was small. In Comparative Example 3, a surface roughness comparable to that of A4 was obtained, but the surface was uneven and rough with coarse pits scattered there.

Example 2 Sample of Yuruya 1 in Example 1 and Comparative Example 1 and Comparative Example 3
An oxide film of 397 m2 was applied to the sample in an electrolytic solution containing 20% sulfuric acid as a main component at a bath temperature of 30C. Then JIS
60C1 by soaking in No. 3 sodium silicate 2.5% aqueous solution.
The sample was treated for 1 minute, thoroughly washed with water, and then dried.

Sample (6), CB
), ((P).The following solution CI was applied to each sample prepared in this way so that the coating weight after drying was 2.09/rIL.
A lithographic printing plate was prepared by setting it so that it became 2.

The photosensitive lithographic printing plate thus obtained was exposed for 70 seconds from a distance of 1 m using a 3KW metal halide lamp, and after immersed in the following developer for 1 minute at room temperature, the surface was lightly rubbed with absorbent cotton to remove the unexposed areas. , the printed version (g), @
, got 0.

[Developer composition]

Sodium sulfite 3g Benzyl alcohol 30.9 Triethanolamine 20g Monoethanolamine 5g Water
1,000 copies were then printed according to a conventional procedure, and the results shown in Table 3 were obtained.

Table 3 Example 3 The samples in Table 2 were electrochemically treated in a 7i7t nitric acid aqueous solution with an electrical quantity of 100 coulombs/cL m2 using the special alternating waveform described in Japanese Patent Application Laid-Open No. 53-67507. was subjected to etching treatment.

Subsequently, it was immersed in a 30% H2SO4 aqueous solution.
After desmutting for 1 minute with C, it was 3J9/m 2 at a bath temperature of 30 tll' in an electrolytic solution containing 20% sulfuric acid as the main component.
An oxide film was provided. Next, it was immersed in a 2.5% aqueous solution of JISB sodium silicate, treated with 60C for 11 minutes, thoroughly washed with water, and then dried.

The surface roughness and bit/e-turn of the support thus obtained were observed using a scanning electron microscope (SEM), and the aperture diameter was collected, and the section prepared using a microtome was observed using SEM to determine the bit depth. It was measured.

The results are shown in Table 4. Sample A6,7゜8,9
．． 10 and Comparative Examples 4, 5.6 are samples A1.2.3.4.5 of Example 19 Table 2 and Comparative Examples 1, 2.3 prepared by the above method.

Table 4 Electrochemical etching treatment performance example 1. Table 2 A2 was subjected to anodizing treatment and hydrophilic treatment according to the method described in Example 2 to obtain a support sample (T).
It was created. Similarly, Table 4 A7 and Comparative Example 5 were used as sample 0. (Let it be q.

Supports thus obtained (G), (B),
In (G), the dry coating amount of the photosensitive layer of Example 2 was 2. ON
/yx2 and set it at 5.

The photosensitive lithographic printing plate thus obtained was exposed for 70 seconds from a distance of 1 m using a 3KW metal halide 2 pump, immersed in the developer shown in Example 2 for 1 minute at room temperature, and then lightly rubbed on the surface with absorbent cotton to remove the unexposed areas. are removed and each lithographic printing plate (
8) (b) Obtained 0.

Next, printing was carried out according to a conventional procedure, and the results shown in Table 4 were obtained.

Table 5 Procedural Amendment June 7, 1982 Patent Application No. 93999 2, Title of Invention Aluminum Alloy Plate for Planographic Printing Island Support and Planographic Printing Support f.3, Person Making Amendment Case and Relationship, patent applicant name (520) Fuji Photo Film Co., Ltd. (and 1 others)
name) 5

Claims (4)

[Claims] (1) Fg is 0.20-1.0 (weight)%, M is 0.20% to 1.0% (weight).
10 to 0.6%, and Sn, In, GW, I, and Zn (contains 0.005 to 0.1% of one of each, or further contains 0.1 to 2% of Cju. An aluminum alloy plate for a lithographic printing plate support, characterized by: (2) Fg is 0.20-1.0 (weight)%, My is 0.20-1.0% (by weight).
10-0.6%, and Sn, In, Cra, and Z
Contains 0.005 to 0.1% of at least one of n,
A lithographic printing plate support comprising an aluminum alloy plate further containing 0.1 to 2% of O and having a surface roughened with acid or alkali. (3) The support for a lithographic printing plate according to claim (2), wherein the surface of the aluminum alloy plate is further electrochemically roughened. (4) The support for a lithographic printing plate according to claim (2) or (3), wherein the roughened surface is anodized.