JPS62148295A - Aluminum alloy base for planographic plate and production thereof - Google Patents

Abstract

PURPOSE:To obtain a minutely roughened surface and prevent contamination of an non-image part in a streak form from occurring, by setting the amounts of Fe, Si and Cu in an aluminum alloy to within respective predetermined ranges and restricting the amount of elemental Si to or below a specified value. CONSTITUTION:An aluminum alloy contains 0.05-1% of Fe, up to 0.2% of Si and up to 0.05% of Cu, the balance being A and unavoidable impurities, with the amount of elemental Si internally distributed being not more than 0.012%. If the Fe content is less than 0.05%, the effects of obtaining finer recrystallized grains and making an electrolytically roughened surface uniform and minutely roughened are slight, whereas if the Fe content is more than 1%, the electrolytically roughened surface will be nonuniform. If the Si content is more than 0.2%, the uniformity of the roughened surface is degraded, and element Si separates out to increase the possibility of contamination of non- image parts. If the Cu content exceeds 0.05%, pits 1 are enlarged in size. By restricting the amount of elemental Si to or below 0.012%, a printing plate can be obtained which hardly generates contamination of non-image parts and has extremely excellent printability.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an aluminum alloy support that is used for planographic printing after anodizing and coating with a photosensitive material. It becomes m-plane,
The present invention relates to an aluminum alloy support for use in planographic printing plates that has extremely high stain resistance in non-image areas during printing (staining and no streaks), and a method for manufacturing the same.

(Prior art) A lithographic printing plate is produced by applying a photosensitive substance to an aluminum alloy plate or the like as a support for the lithographic printing plate after surface treatment such as roughening treatment and anodizing treatment. Taoroku Hearth Fu1. 7, A1 Yuinhaku 11: υji Shit A printing plate with image areas formed by plate-making processes such as light and development,
After wrapping this around the cylindrical copper plate of a printing press, the ink is applied to the printing area in the presence of dampening water applied to the non-image area, and this ink is applied to the printing press. transcribe,
Then, lithographic printing is performed by printing on one sheet of paper.

Conventionally, such an aluminum alloy plate for lithographic printing has been used as one suitable for vapor chemical phase treatment.
After homogenizing an aluminum alloy containing 0.35 to 1% by weight of Fe (hereinafter ψ% is abbreviated as %) and 0.2% or less of Si, it is hot rolled to form a cold JE' of 40 to 80%. y
4 aluminum alloy plate (Japanese Patent Application Laid-Open No. 55-288
No. 74), Fe 0, 1-10%, Si 0.
02 to 0.15% and Cu0003% or less (Japanese Unexamined Patent Publication No. 58-221254) has been proposed, and an aluminum alloy sheet containing a predetermined amount of Fe and Si has been proposed in Japanese Patent Application Laid-open No. 58-221254. No. 42493, 59-
No. 67349.

(Problems to be Solved by the Invention) When used, a uniformly roughened surface can be formed by electrochemical 11-sided treatment. However, in these aluminum alloy plates, medium streaks (streak-like unevenness) occur during the 11-sided processing, which greatly impairs the aesthetic appearance, or t'2'! When printing Obe Ko (Satobu I'2), it was not possible to overcome the problems of ink adhering to non-image areas and staining the printed matter.

Among these: 1. :・If the hot rolling conditions are not appropriate, coarse recrystallized grains (~100 μm or more) are generated between hot rolling passes, and their outline remains even after the final cold rolling, resulting in electrolytic surface roughening treatment. This is thought to be because when the rolling direction is applied, fibrous streaks (streak-like unevenness) extending in the rolling direction appear.

Also,'? Contamination in the non-image area of . is caused by the presence of a specific intermetallic compound, which causes unhealthy areas in the anodic oxidation skin 11:ma, and because the potential difference with the A♀ matrix is different, it becomes a starting point for corrosion, causing the contamination to occur. It is something that occurs.

Therefore, it is an object of the present invention to obtain a uniform, finely roughened surface by electrochemical surface roughening treatment, to avoid the occurrence of streaks (streak-like unevenness), and to minimize stains in non-image areas during printing. By providing an aluminum alloy plate for lithographic printing plates that does not generate the above problems (means for solving the problem), the inventors of the present invention have conducted intensive research to overcome the deficiencies of the conventional aluminum alloy plates mentioned above. As a result, an aluminum alloy plate in which the concentrations of Fe, Si, and Cu in the aluminum alloy are set to 111, and the amount of 9 of S+ in the aluminum alloy is regulated to be below a certain limit, meets the requirements of item I. This discovery led us to create the present invention.

That is, in the present invention, Fe 0.05~1%, Si
0.2% or less, Cu 0.05% or less, remainder r:'dA
41+ characterized by Q and unavoidable impurities being distributed inside the Cti form Si of 0.012% or less
an aluminum alloy support for printing plates, and Fe
o, 05-1%, Si 0.2% or more, Cu 0,
05% or less, and the remainder contains unavoidable impurities, is subjected to soaking treatment If-d, A〇I++1
Cool at a uniform cooling rate of ~1〒, 1■
Or after holding at a temperature of 350 to 450'C for 30 minutes or more, hot rolling or after hot rolling, cold rolling and intermediate annealing, followed by final cold rolling with an area reduction of 50% or more. By this, the elemental Si distributed inside is reduced to 0.012%.
The present invention provides a method for producing an aluminum alloy support for a lithographic printing plate, which is characterized by the following.

First, the alloy composition used in the present invention will be explained.

In the alloy composition, Fe is O, and is in the range of '05 to 1%. Fe has the effect of making the electrolytically roughened surface uniform (T.F
e is an element that binds other elements -k in the aluminum alloy to form a eutectic compound of A-Fe system, and
E-based eutectic compounds are effective in refining recrystallized grains and forming uniformly fine electrolytic surfaces.If the content is less than 0.05%, recrystallized grains are refined and electrolytically coarsened. The uniform-fine Ml+ effect on the planarized surface is small, and - when the content exceeds 1 zoro of 7.1.

The content of Si is 0.2% or less. Si is included as a normal impurity, and if it exceeds 0.2%, the uniformity of the particles will be impaired. Since the precipitation of elemental Si, which will be described later, is likely to occur, stains in non-image areas are also likely to occur.

The reason why Cu is limited to 0.05% or less is because C is an impurity.
If u exceeds 0.05%, the four parts (pinto) produced by electrochemical roughening treatment tend to become coarse, and
This is because the stain resistance of non-image areas of the printing plate is reduced. In addition, the amount of elemental Si in the final cold-rolled plate was set to 0.0
The reason for limiting the amount to 12% or less is that the single substance 5j remains in the anodized film due to the anodizing treatment and forms film defects, which becomes the starting point for staining in non-image areas during printing. It has been discovered that by reducing the amount of Si to 0.012% to 12% or less, a printing plate that is less likely to stain in non-screen areas and has excellent printability can be obtained.

Impurities contained in the aluminum alloy constituting the lithographic printing plate support in the present invention include:

The purpose of the present invention will not be impaired if the impurities are at the same level as those contained in commercially available Al ingots.

1! There is no particular problem if p, Mn is 0.05% or less, Cr is 0.05% or less, and Zn is 0.05% or less.

In addition, when producing t4j lumps, Ti and B, which are usually used as crystal refiners, contain less than 0.05% Ti and B
Addition of 0.01% or less is effective in uniformly refining the alloy structure.The support for the upper printing plate of the present invention is produced by soaking an aluminum alloy ingot having a composition of 110. In this way, impurities are dissolved in solid solution, a portion of Fe is dissolved in solid solution, and a portion of the intermetallic compound of Fe is uniformly and finely dispersed. This scorching treatment is desirably carried out at a temperature of 500 to 620° C. for 3 hours or more. Next, Si atoms are released into the ingot by cooling it at an average cooling rate of 50°C/hour or less until it reaches a temperature of 430°C or less, or by holding it at a temperature of 350 to 450°C for 30 minutes or more. Al-Fe-
It is precipitated as a 5i-based intermetallic compound to reduce the amount of elemental Si precipitated in the subsequent process. Moreover, since this AM-Fe-3i gold metal compound acts as a nucleus for recrystallization between hot rolling passes, it has a recrystallized grain refinement effect and is extremely effective in preventing the occurrence of streaks. Thereafter, hot rolling or hot rolling followed by cold rolling and intermediate annealing are performed in a conventional manner.

The hot rolling temperature is suitably 450 to 200°C. When the hot rolling start temperature exceeds 450° C., recrystallized grains between hot rolling passes become coarse, 100 μm or more, and streaks are likely to occur. It is desirable that the intermediate annealing after hot rolling be carried out at 350 to 500°C for 2 to 5 hours or in a continuous annealing furnace at 400 to 550°C for 120 seconds or more.

The plate thus obtained is finally cold rolled so that the reduction in area is 50% or more. In this final cooling rolling, intermetallic compounds are dispersed and the crystal structure becomes uniform. If the area reduction rate is less than 50%, the intermetallic compound will not be sufficiently dispersed, resulting in uneven crystal formation.

The cold-rolled plate thus obtained has 0.012% or less of ri-form Si present inside, and the solution is $11.
A uniformly roughened surface is obtained by the surface treatment, and the ox printing plate is used, which does not cause streaks and has excellent stain resistance in non-image areas during printing.

Incidentally, in order to impart appropriate ductility to the final cold-rolled sheet and improve its fatigue strength, temper annealing may be performed under the following conditions in which precipitation of elemental Si does not occur. Temperature annealing is preferably carried out at 70 to 180'0 for 30 minutes or more in a 6-way patch furnace. 70℃ or higher or 3
Less than 0 minutes is not very effective, and above 180℃ rJ
Precipitation of + form Si occurs, impairing the stain resistance of non-image areas. Temperature annealing may be carried out in a continuous annealing furnace that is characterized by rapid temperature rise and short-time heating, and in this case, the
It is suitable to heat at 11'C for 120 seconds or more.

If it is less than 150'C, the effect will be insufficient, and if it exceeds 400'C, the temporary will become too soft, and it will not last longer than 8 or 120 seconds.
m+ 0ILnu l! n −n I−) /←＋＊
Species a<+llj/h・S Next, the method for surface treatment of a support for a lithographic printing plate according to the present invention will be described in detail.

The graining methods used in the present invention include an electrochemical graining method in which graining is carried out electrochemically in a hydrochloric acid or nitric acid electrolyte, a wire brush graining method in which the aluminum surface is scratched with a metal wire, and a polishing method in which the aluminum surface is polished using an abrasive. Mechanical graining methods such as the ball grain method for graining and the brush grain method for graining the surface using a nylon brush and abrasive can be used, and any of the above graining methods can be used alone or in combination. can.

Aluminum grained in this way.

Chemically etched with acid or alkali. When an acid is used as an etching agent, it takes time to destroy the fine structure, which is disadvantageous in industrial application of the present invention, but this can be improved by using an alkali as an etching agent.

The alkaline agent suitably used in the present invention is j+'
(Use sodium hydroxide, carbonate sorter, aluminate sorter, metasilicate soda, sodium phosphate, potassium hydroxide, lithium hydroxide, etc., and the preferred range of concentration and temperature is 1.
~50%, 20-100°C, and A! ; Conditions are preferred such that the amount of L dissolved is 5 to 20 g/rrI'.

After etching, pickling is performed to remove dirt (smut) remaining on the surface. The acids used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and fluoroboric acid. In particular, for smant removal treatment after electrochemical surface roughening treatment, it is preferable to
Method of contacting with 65% sulfuric acid and Special Publication No. 1973-2
This is an alkali etching method described in Japanese Patent No. 8123.

The aluminum plate treated as described above can be used as a support for a lithographic printing plate, but it is preferable to further perform treatments such as anodizing 11Q% treatment and chemical conversion treatment as necessary.

The anodic oxidation treatment can be performed by a method conventionally used in this field. Specifically, when a direct or alternating current is passed through aluminum in an aqueous or non-aqueous solution of sulfuric acid, phosphorous, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc. or a combination of two or more of these, the aluminum support becomes An anodic oxide film can be formed on the surface.

The treatment conditions for anodic oxidation vary depending on the electrolyte used, so they cannot be determined unconditionally.

Generally, the concentration of electrolyte is 1-80%, and the liquid temperature is 5-70℃.
, current density 0.5-60 ampere/d m'.

A range of heavy pressure of 1 to 10 m and electrolysis time of 10 to 100 seconds is appropriate.

Among these anodic oxide coating treatments, it is particularly used in the invention described in British Time 1:1 Specification No. 1,412,768. The method of anodizing at high current density in sulfuric acid and the phosphoric acid electrolytic bath anodized aluminum plate described in U.S. Pat. Same 3rd,
No. 181.461, by dipping in an aqueous solution of an alkali metal silicate, for example, sodium silicate, or
A subbing layer of hydrophilic cellulose (such as carboxymethylcellulose) containing a water-soluble metal salt (such as zinc acetate) may also be provided, as described in US Pat. No. 0,426.

A photosensitive layer conventionally known as a photosensitive layer of a PS plate can be provided on the support for a planographic printing plate according to the present invention to obtain a photosensitive planographic printing plate, which can be obtained by plate-making processing. Lithographic printing plates have excellent performance.

The compositions used in the photosensitive layer include the following.

(A photosensitive layer consisting of a diazo resin and a binder) A diazonium salt and an organic condensing agent containing a reactive carbonyl group such as an aldol or an acetal are disclosed in U.S. Pat. A condensation product (so-called photosensitive diazo resin) of diphenylamine-p-dianium salt, which is a reaction product with formaldehyde, is preferably used.Other useful condensed diazo compounds are described in Japanese Patent Publication No. 49-48001,
It is disclosed in the respective publications such as No. 49-45322 and No. 49-45323.

These types of photosensitive diazotized compounds are usually obtained in the form of water-soluble inorganic salts and can therefore be coated from aqueous solution. Or these water-soluble diazo compounds
A substantially water-insoluble photosensitive reaction product obtained by reacting with an aromatic or resinous compound having one or more phenolic hydroxyl groups, sulfonic acid groups, or both by the method disclosed in Publication No. 67 Polymeric diazo resins can also be used. It can also be used as a reaction product with hexafluorophosphate or tetraroborate as described in JP-A-56-121031. In addition, diazo resins described in British Patent No. 1,312,925 are also preferred.

(2) Photosensitive layer made of 0-quinonediazide compound Particularly preferred 0-quinonediazide compounds are 0-naphthoquinonediazide compounds, such as U.S. Pat.
No. 59112, No. 2907665, No. 30461
No. 10, No. 3046111, No. 3046115, No. 3046118, No. 3046119, No. 3046120, No. 3046121, No. 304
No. 6122, No. 3046123, No. 306143
No. 0, No. 3102809, No. 3106465,
It is described in numerous publications including the specifications of the same No. 3635709 and the same No. 3647443, and these can be suitably used.

■Azide compound and binder (photosensitive layer consisting of a polymer compound) For example, British Patent No. 1235281, British Patent No. 149586
A composition comprising an azide compound and a water-soluble or alkali-soluble polymer compound described in the specifications of No. 1 and JP-A-51-32331 and JP-A-51-36128.

In addition to objects, JP-A-50-5102, JP-A No. 50-84302
The present invention includes compositions comprising a polymer containing an azide group and a polymer compound as a binder, which are described in the following publications: No. 1, No. 50-84303, and No. 53-12984.

174) Other photosensitive resin layers, such as polyester compounds disclosed in JP-A-52-96696, British Patent No. 112277, British Patent No. 1313309, British Patent No. 1341004, British Patent No. FM1377747, etc. Polyvinyl cinnamate resins are described in US Pat. No. 4,072,528 and US Pat. No. 4,072,527. The amount of photosensitive layer provided on the support is about 0.1 to about 7 g/
M? , preferably in the range of 0.5 to 4 g/rn'.

After the PS plate is image exposed, a resin image is formed by processing including development using conventional methods.

For example, the photosensitive layer consisting of a diazo resin and a binder
In the case of a PS plate having a lithographic printing plate, 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 PS plate having a photosensitive layer (1), after image exposure, the exposed portion is removed by developing with an alkaline aqueous solution to obtain a lithographic printing plate.

(Example) Hereinafter, it will be explained in more detail based on Examples.

Example 1 Aluminum alloys No. 1 to No. 1 with the composition shown in Table 1
12 is melted and cast, both sides are exposed to a thickness of 350cm and a length of 2000mm! 1 liter of ingot, and this is heated to 560°C.
Soaking treatment was carried out for 0 hours. This was hot-rolled at a temperature of ℃ to 260℃ to a plate thickness of 4.0 mm, and then further rolled to a plate thickness of 0.3 mm.
The aluminum alloy plate for a 41st edition printing plate was produced by cold rolling (area reduction=F 92 , 5%).

Next, No. 1-No. 12 aluminum alloy rolled plates and No. 13 (plate thickness 0, 30 mm J T 51050
-H18 aluminum alloy), No.

14 (plate thickness 0.30 mm JIS1100-H16 aluminum alloy) was grained with a rotating nylon brush in a Q% solution of pumice stone and water, and then the aluminum was dissolved Nf/'+f or 5 g using a caustic sorter 20% aqueous solution.
/ m2. After thoroughly washing with running water, pickling with a 25% nitric acid aqueous solution and washing with water, a substrate was prepared. The board prepared in this way was
As described in Japanese Patent No. 146234, nitric acid 1.
In an electrolytic bath containing 5% IR,'! E degree 20A/dm
AC electrolysis was carried out at a temperature of 15% sulfuric acid at 50°C.
After cleaning the surface by immersing it in an aqueous solution for 3 minutes, it was immersed in an electrolytic solution containing 20% sulfuric acid as a main component at a bath temperature of 30°C and 3 g/
An oxide film of m'' was provided.

The following photosensitive layer was provided on the sample prepared in this manner so that the dry coating rlj:It was 2.5 g/m'.

Ester compound of naphthoquinone-1,2-diazido-5-sulfonyl chloride, pyrogallol, and acetone resin (described in the Examples of US Pat. No. 3,635,709) ----0, 75g Cresol novolac resin-- --2, OOg Oil Blue #603 (manufactured by Orient Chemical Co., Ltd.) --, ---0, 04 g Ethylene dichloride ---1-16 g 2-Methoxyethyl acetate) --12 g Photosensitive lithographic plate thus obtained The printing plate was brought into close contact with the transparency and exposed for 30 seconds from a distance of 1 m using PS light (Toshiba metal halide lamp MU2000-2-OL type 3KV antigen, sold by Fuji Photo Film Co., Ltd.). After that, it was immersed in a 5% by weight aqueous sodium silicate solution for about 1 minute, developed, washed with water, and dried.

15 was created.

Sample No. 1-No. prepared in this manner.

A test was conducted to determine the uniformity of the electrolytically etched rough surface of No. 15, the occurrence of stains and streaks in the non-image area, and the results are shown in Table 1.

(Test method) (1) - Uniformity of the itE-etched rough surface The surface condition was observed with a scanning electron microscope, and the uniformity of focus was evaluated: excellent (○), good (Δ), poor (X) Represented by a mark.

(2) Status of streak occurrence Visually observe the electrolytically etched rough surface and mark O if no streaks have occurred, mark Δ if streaks have occurred in some areas, and mark X if streaks have occurred over the entire surface. Ta.

(3) Dirt in the non-image area 100,000 copies printed on the KOR offset printer
iiψKuma no Hakugen - Le Chosen Price 1 - The six excellent ones were marked with an O mark, good ones with a Δ mark, and poor ones with an X mark.

Incidentally, the simple substance S i jil was quantitatively analyzed by the analytical method described in Japanese Patent Application Laid-open No. 82642/1983.

As is clear from Table 1, the aluminum alloy plates No. 1 to No. 7 for printing obtained by the method of the present invention all had the amount of insect S+ distributed inside them being 0.012% or less, and had a rough electrolytically etched surface. It can be seen that all properties were satisfied in terms of uniformity of color, stain resistance in non-image areas during printing, and streak resistance, and were superior to the conventional JIS 1050.1100. On the other hand, in aluminum alloy plates No. 18 to 12 with comparative alloy compositions outside the composition range of aluminum alloy plates in the method of the present invention, single 5ilz is distributed inside.
Example 2 The alloy ingot of N002 in Table 1 in Example 1 was 55%
After performing soaking treatment at a temperature of 0°C for 8 hours and cooling it under various cooling conditions shown in Table 2, it was hot rolled to a plate thickness of 4.5 mm, and further cold rolled to a plate thickness of 2.0 mm. After that, it was intermediately annealed in a continuous annealing furnace at a temperature of 480° C. for 20 seconds, and then cold-rolled to a plate size of 1”7.0 and 3 mm to produce an aluminum alloy plate for printing plates.

These were subjected to surface treatment in the same manner as in Example 1, and plate making was performed under the same conditions to create Samples Nos. 15 to 24.

These samples were subjected to the same test as in Example 1 for 11""
°゛・+ty＞, &'; 812 Table 101・ , /
′, /” ,,￥ /” As is clear from Table 2, after soaking the ingot, 43
Printing plates Nos. 15 to 19 according to the present invention were cooled at an average cooling rate of 1 bar at 50° C./hour or less to a temperature of 0° C. or less, and then hot rolled, cold rolled, intermediate annealed, and cool rolled. It can be seen that when the amount of elemental Si distributed inside is 0.012% or less, the uniformity of the rough surface, the staining property of the image area, and the streaking property are impaired.

On the other hand, in comparative printing plates No. 20 to 24, in which the amount of elemental Si distributed inside exceeds 0.012%, that is, aluminum alloy plates for printing plates where the cooling conditions after soaking treatment are different, stains in non-image areas are not improved and It can be seen that streaks also occur.

Example 3 Using alloy ingots No. 2 in Table 1 in Example 1,
After soaking it at 540°C for 8 hours, holding it under the conditions shown in Table 3, hot rolling it to a thickness of 3.5 mm,
Thereafter, it was cold rolled to a thickness of 0.3 mm. This was subjected to surface treatment in the same manner as in Example 1 to prepare samples Nos. 25 to 33.

The same tests as in Example 1 were conducted on these, and as is clear from Table 3, printing plates Nos. 25 to 2 according to the present invention were kept at a temperature of 350 to 450°C for 30 minutes or more after soaking.
It can be seen that Sample No. 9 all contained 0.012% or less of elemental Si acid, and were excellent in uniformity of the rough surface, staining in non-image areas, and streak resistance.

On the other hand, in comparison printing plates Nos. 30 to 33, in which the ingot retention conditions after soaking treatment are different, the amount of elemental Si distributed inside exceeds 0.012%, indicating that stains in non-image areas are not improved. .

(Effects of the Invention) As described above, the lithographic printing plate support of the present invention has excellent rough surface uniformity, is less likely to cause stains in the non-image areas of printed matter, and can prevent the occurrence of streaks. It has remarkable effects as a lithographic printing plate that also has the following characteristics.

Claims (2)

[Claims] (1) Fe0.05-1%, Si0.2% or less, Cu0
, 0.05% or less, the balance being Al and unavoidable impurities, and the elemental Si distributed inside is 0.012% or less (wherein, % indicates weight %). body. (2) Fe0.05-1%, Si0.2% or less, Cu0
．． After soaking an aluminum alloy ingot consisting of 0.5% or less, the balance being Al and unavoidable impurities, it is cooled to a temperature of 430°C or less at an average cooling rate of 50°C/hour or less, or at a temperature of 350 to 450°C. After holding for more than 30 minutes,
By performing hot rolling or after hot rolling, cold rolling and intermediate annealing, and adding final cold rolling with an area reduction rate of 50% or more, the elemental Si distributed inside is reduced to 0.012% (or more, (% indicates weight %) or less.