JPS59133356A - Manufacture of aluminum alloy for printing - Google Patents

Abstract

PURPOSE:To manufacture the titled alloy showing superior uniformity and strength and having pits provided with a dual structure by subjecting an Al alloy contg. Mg and Mn to final cold rolling to form an Al alloy plate and by subjecting the plate to electrolytic surface roughening with AC in an electrolytic soln. contg. nitric acid. CONSTITUTION:An Al alloy consisting of, by weight, 0.3-5% Mg, 0.3-2% Mn and the balance Al with impurities or further contg. 0.05-1wt% Cu is subjected to final cold rolling at 10% draft to form an Al alloy plate. The plate is subjected to electrolytic surface roughening with AC in an electrolytic soln. contg. nitric acid to pierce secondary pits having complex unevenness in the surfaces of deep and large primary pits. The resulting plate has pits provided with a dual structure and shows superior uniformity and strength. The plate can be made thin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an aluminum alloy for printing, and more specifically, it is used as a support for a 28 plate used in offset printing, and is capable of achieving excellent uniformity and a double structure in electrolytic roughening. The present invention relates to a method for producing an aluminum alloy for printing.

Generally, in offset printing, aluminum plates have been used as supports for a long time, and it is necessary to roughen the surface from the viewpoint of adhesion of the photosensitive film and water retention in non-image areas. .

Conventionally, mechanical treatment methods such as ball polishing and brushing have been used to roughen the surface. A method has been adopted in which the surface of the plate is electrochemically etched and roughened using nitric acid or an electrolytic solution mainly composed of nitric acid (hereinafter referred to as nitric acid photoelectric solution). This electrolytic surface roughening method has been rapidly developed in recent years because the resulting roughened plate has excellent plate-making suitability and printing performance, and is suitable for continuous processing of coil materials.

Conventionally, for aluminum plates for off-cent printing, JIS standards 1\1050 and A are used for mechanical roughening.
A material equivalent to 1100, A 3003 is used, and a material equivalent to A 105 (1) is generally used for electrolytic surface roughening.

When the electrolytic surface roughening treatment method is applied to these conventional aluminum plates, the electrolytically focused structure is as follows.

1) In the case of hydrochloric acid electrolyte, the pits themselves are deep and each pit is relatively large;
The pit surface is relatively smooth.

2) In the case of a nitric acid-based electrolyte, relatively small honeycomb-like irregularities are formed, but the overall depth of the pits is shallow.

Differences in the pit structure of the roughened surface as described above affect the printing performance and printing durability of the plate material. For example, ゛The material is suitable for printing newspapers, magazines, etc., where printing durability is important, and the plate material with a rough surface, such as that obtained with nitric acid-based electrolyte, is suitable for printing such as printing materials that require delicate images, catalogs, etc. Although suitable for commercial art printing, they are inferior to hydrochloric acid-based electrolytes in terms of printing durability, and are intended for printing with a relatively small number of copies, so there are some limits to the range of their respective applications.

In addition, since A105 (1'4) is made of pure aluminum, its strength is low, and when the tube is thinned or subjected to burning treatment (usually at 200 to 300 °C for 3 to 10 minutes), the plate material bends easily and is difficult to handle. was there.

Such conventional printing aluminum alloy electricity 1
lf
We have conducted repeated research in an effort to obtain an aluminum alloy face plate for offset printing plates that has both the characteristics of a face plate and a roughened plate made from a nitric acid electrolyte, has high strength, and has high strength even after burning treatment, as well as improved uniformity. As a result, the present invention was completed.

The method for producing an aluminum alloy for printing according to the present invention includes (
1) An aluminum alloy plate is produced by final cold rolling an aluminum alloy containing 0.3 to 5% by weight of N and 3 to 2% by weight of Mn (2017), with the balance consisting of aluminum and impurities at a rolling rate of 10% or more. The first invention is a method for producing an aluminum alloy for printing, which is characterized by subjecting this aluminum alloy plate to electrolytic surface roughening treatment using alternating current in a nitric acid-based electrolyte, and (2) to Mg 0.3. 5% by weight, M
An aluminum alloy containing ++0.3-2% by weight, Cu O, 05-1% by weight, and the balance consisting of aluminum and impurities is subjected to final cold rolling at a rolling rate of 10% or more to obtain an aluminum alloy plate, and this aluminum alloy This invention consists of two inventions, the second invention being a method for producing an aluminum alloy for printing, which comprises subjecting a plate to electrolytic surface roughening treatment using an alternating current in a nitric acid-based electrolyte.

That is, - by performing electrolytic surface roughening treatment using alternating current in a nitric acid-based electrolyte using the aluminum alloy plate described above)
), it has a double structure in which secondary pits with complex irregularities are formed on each pit surface of a deep and large primary focus, and it has excellent uniformity. Furthermore, it has excellent mechanical properties and high strength, so it can be made thinner. It is something.

Hereinafter, regarding the method for producing an aluminum alloy for printing according to the present invention, the components and proportions of the aluminum alloy used and the electrolytic surface roughening treatment method will be explained in detail.

First, the components and component ratios of the aluminum alloy will be explained.

By performing electrolytic surface roughening treatment using alternating current in a nitric acid-based electrolyte, a deep and large primary focus and a secondary focus with complex irregularities on the bit surface, that is, a double-structured focus is formed. It is an effective element for
Contains M8:? If the amount exceeds 5% by weight, the effect of forming a double structure focus will be saturated and it will be economically wasteful, and problems such as increased edge cracking will occur in the manufacturing method of rolled plates, and furthermore, it will be required for printing plates. The bending properties also tend to deteriorate, which is not preferable. Therefore, the M8 content is 0.3 to 5 times the weight.

Mn is an effective element for improving the uniformity of bits, and if the content is less than 0.3%, the effect of improving uniformity is not sufficient, and if the content exceeds 2% by weight, If this happens, the size of the M11-based intermetallic compound increases, which tends to impair uniformity during electrolysis, which is not preferable. Therefore, the Mn content is set to 0.3 to 2% by weight. Although Mg
When the content is 2% by weight or more, the content of Mn1j is preferably 1% by weight or less.

Cu is an element that is effective for enhancing the etching effect by electrolytic surface roughening and also for adjusting the shape of the secondary focus. The effect cannot be obtained sufficiently, and 1
If the content exceeds the weight percent, the amount of etching during electrolytic etching becomes excessive, which is not preferable. Therefore, the Cu content is set to 0.05 to 1% by weight. The desirable content is 0.05 to 0.5% by weight, including corrosion resistance.

Regarding impurities, there is no problem as long as they are within the range normally contained in commercially available industrial pure aluminum, but Fe may be contained up to 7% by weight, and Sl may be 0.3% by weight.
The content may be up to % by weight, but if it exceeds these ranges, it is not preferable because it tends to cause non-uniform etching during electrolytic roughening process and unetched areas are likely to occur. In addition, the inclusion of Ti for refining the ingot structure is A I-Ti
, TiB particles, etc. tend to agglomerate, resulting in non-uniform 111 planes in electrolytic surface roughening treatment, so the TiL7) content is preferably f'1.05% by weight or less, preferably 0.02% by weight or less. Should it be less than the footrest?

A cast aluminum alloy having such components and ratios is cast by a conventional method. In this case, continuous thin plate casting may be performed from the viewpoint of energy saving and improvement of mechanical properties.

The 1:1 ingot is homogenized, hot rolled, cold rolled,
After going through steps such as intermediate annealing, it is processed into an aluminum alloy plate with a thickness of 0.1 to 0.5 Il+m.

At this time, it is necessary that the rolling ratio of the final cold rolling is 10% or more. Aluminum alloy plates for printing plates require a great deal of manual handling during the plate-making and printing processes.
Even if the absolute value of the 2nd grade is high, handling problems such as buckling occur especially when the thickness is reduced, making it difficult to put it into practical use.

In addition, in order to reliably achieve this objective such as reproducibility, it is preferable to set the rolling ratio to 20% or more.

Next, the aluminum alloy plate obtained in step 2 is subjected to an electrolytic 11-sided treatment.

However, prior to electrolytic surface roughening, the aluminum alloy plate is subjected to surface treatment to remove rolling oil from the surface and to make the aluminum alloy plate surface clean, if necessary. Generally, a treatment method is used to remove rolling oil by cleaning the surface of the aluminum alloy plate using a solvent such as trichloride or a surfactant, and the cleaning rate of the aluminum alloy plate surface is 1 to 10%.
20~ in aqueous solution such as sodium hydroxide or potassium hydroxide
? Soak for 5-300 seconds at a temperature of 0'C then 1()
A widely used method is to immerse the material in an aqueous solution of ~20% nitric acid or sulfuric acid at a temperature of 1°C to 50°C for 5 to 300 seconds to neutralize and remove smut after alkaline etching.

The electrolytic surface roughening treatment is performed after the surface cleaning of the aluminum alloy plate is completed.As the electrolytic solution used in this electrolytic Mtl single surface treatment, a conventionally known aqueous solution containing nitrate ions can be used. A particularly preferred electrolytic solution is a nitric acid solution having a concentration of 0.5 to 5 times the concentration. In this electrolytic solution, as corrosion inhibitors or stabilizers, nitrates such as ammonium nitrate and lithium nitrate, amines such as trimethylamine, noetalamine, ethylenediamine, hexamethylene diamine q, aldehydes of formaldehyde, and phosphorous are added to the electrolyte. Acid, chromic acid, and sulfosalicylic acid can be contained in an amount of 0.05 to 3% by weight.

The temperature of the IW liquid is usually 10-40'C, preferably 15-30'C.

The alternating current used when carrying out the electrolytic 11-sided treatment using this electrolytic solution is a current with a waveform obtained by alternately exchanging positive and negative polarities, and includes alternating waveform currents such as rectangular waves and trapezoidal waves. However, normal commercial alternating current, ie, sinusoidal single-phase and three-phase alternating current, is sufficient.

If necessary, the aluminum-cum alloy plate treated under the same conditions as above is desmatted by immersing it in an aqueous alkali or acid solution at a temperature of room temperature to 80°C for 1 to 50 minutes, and then desmutting in a medium temperature. After being cured, it is used as a support for printing plates. In addition, when using the aluminum alloy plate as a support for printing plates, it is said that if the rough surface of the aluminum alloy plate is further anodized using a conventional method, it will become more hydrophilic than the aluminum alloy base state, making it easier to print and improving printing durability. effective.

Next, examples of the method for producing an aluminum alloy for printing according to the present invention will be described together with comparative examples.

Example @ 1 An aluminum alloy plate was melted and cast by a conventional method so that the ingredients and proportions shown in Table 1 were obtained.
B) Surface roughening treatment was performed.

Table 1 Nos. 1 to 4 are aluminum alloys used in the method for producing an aluminum alloy plate according to the present invention.

No. 5 to No. 8 are aluminum alloys of comparative examples.

Electrolytic treatment conditions No. 1-No. 7 1.6% HNO0, 25°C 160A/d+n2X 2
0 seconds No, 83% FICI, 25°C, 60 A/dm
2X 20 seconds Table 2 shows the focus morphology, average roughness, and mechanical properties after electrolytic surface roughening.

Symbols A, B, and C indicating bit formats in Table 2 will be explained.

A: Indicates a double-structured bit in which secondary pits with complicated irregularities exist on the bit surface of primary pits.

B: As mentioned above, the surface of the conventional phase is roughened with a nitric acid electrolyte, and the surface is small and has a honeycomb shape, and the depth is generally shallow.

C: When a conventional material is roughened with a hydrochloric acid electrolyte, the individual bits are relatively large, but the pit surface itself is relatively flat.

Table 2 As is clear from Table 2, Nos. 1 to 4 according to the manufacturing method of the printing aluminum alloy according to the present invention have a double structure focused form after being made into 11-sided electrolytic layers and have uniformity. It can be seen that it has excellent strength and strength compared to Lisa et al.

Scanning electron micrograph showing electrolytic surface roughening (magnification 100)
0x) are shown in Figures 1 and 2 for No. 3 and No. 5.

As can be seen from this example, the manufacturing method of Luminara and Coating for printing according to the present invention (-) The aluminum interlayer plate has a double structure with a slanted double structure and a uniform +f Concern: 21i moderate depth is used as a printing plate - C is very suitable, so there is, and the degree is also high;
4. The manufacturing method of the aluminum alloy is based on the structure of the book, so the aluminum alloy and aluminum alloy that cannot be used in the
411 metamorphosis plate is an off-sera printing plate with compound unevenness on the pit surface of one large bit with good deep depth.
It has a double structure in which a dog bit is formed, and has the excellent effects of good uniformity, high strength, and high strength and low thickness.

[Brief explanation of the drawing]

FIGS. 1 and 2 are microscopic photographs of the surface metal structures of No. 3 and No. 5 showing the degree of phase difference due to electrolysis.

Claims (2)

[Claims] (1) Mg 0.3-5% by weight and Mn(1,3
% to 2% by weight, with the balance consisting of aluminum and impurities, is subjected to final cold rolling at a rolling ratio of 10% or more to obtain an aluminum alloy plate, and this aluminum alloy plate is heated in a nitric acid electrolyte with alternating current. 1. A method for producing an aluminum alloy for printing, characterized by subjecting it to electrolytic surface roughening treatment. (2) Mg0.3-5 weight Mn0.3-2 weight 1%,
An aluminum alloy containing CuO', 05 to 1,000% by weight and the balance consisting of aluminum and impurities is subjected to final cold rolling at a rolling rate of 10% or more to obtain an aluminum alloy plate, and this aluminum alloy plate is treated with a nitric acid-based electrolyte. 1. A method for producing an aluminum alloy for printing, which comprises performing electrolytic surface roughening treatment using an alternating current.