JPS61186109A - Aluminum and aluminum alloy sheet for building member - Google Patents

Abstract

PURPOSE:To simplify an etching stage by reducing the directional properties of the surface roughness of a titled sheet and to improve the productivity of the sheet, by forming the rough surface of sheet wherein the crests of specific height exist in number not less than those of required numbers with the aid of a surface-roughened roll. CONSTITUTION:An aluminum or aluminum alloy sheet for building member is rolled by a surface-roughened roll, so that the height of its highest surface- crest is >=2mum within a measuring length of 25.4mm and the number of crests, having each >=1.27mum height, are >=25 within the measuring length of 25.4mm, in the parallel or perpendicular direction to the rolling direction at least. Here, it is preferable that the maximum height of crest is 16mum and the maximum number of crests are about 150. By rolling the sheet in such manner, etching at the stage prior to an anodized aluminum working can be simplified because the directional properties of the surface roughness of sheet can be sufficiently made small.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to aluminum and aluminum alloy plates used for members of exteriors, interiors, interiors, etc. of buildings.

[Prior art and its problems] Most of the aluminum alloy plates produced are DC plates with a so-called dull finish (DC), and the remaining part is a DC plate with a mirror-like surface, that is, a bright finish. It was produced as a BC board with a finished surface (BC).

These DC plates and BC plates are usually subjected to etching and alumite treatment after rolling and are used as building materials.

By the way, the special properties required for this kind of aluminum and aluminum alloy plates for building materials include (i) excellent etching properties, and (ii) no directionality. Regarding improvement of etching properties (i), as will be described later, there is already an invention by the present inventors (referred to as a prior invention), and the applicant has previously filed a patent application for the content of the invention (referred to as a prior invention). (No. 193430, 1973).

On the other hand, direction (ii) refers to the conventionally frequently used DC
The plate has a directional surface roughness after rolling, and even after a relatively long period of time (about 10 minutes) etching, the directionality of the surface roughness is not sufficiently removed and the surface roughness is not completely removed. ^
-! Loj-old also means that it is recognized as the direction of the candy mu button divination 4bi tread day μ. In this way, when a product has a certain direction, (a) it is difficult to match the colors between multiple boards, and (
b) Problems such as difficulty in mixed vertical and horizontal arrangement occur. or,
As mentioned above, when the etching period becomes longer, other problems arise, such as lower productivity and severe deterioration of the chemical.

In addition, as a means to supplement the directionality removal by etching, the chemical composition and manufacturing method of aluminum and aluminum alloy materials have been investigated, but sufficient results have not been obtained.

[Background of the Invention] By the way, the present inventors have already used rolling rolls with roughened surfaces when rolling aluminum and aluminum alloy plates to improve the surface of the aluminum and aluminum alloy plates compared to conventional DC plates. We have discovered scales that improve the etching properties of aluminum and aluminum alloy plates by roughening the surface (the above-mentioned prior invention).

Subsequently, as a result of further research, by roughening the surface of aluminum and aluminum alloy plates using a roughening roll, it was possible to improve the etching properties and reduce the directionality of the surface roughness. and obtained the knowledge that aluminum and aluminum alloy plates produced by such a roughening roll method are suitable as building materials.

[Structure of the invention] The present invention has been made based on the above-mentioned findings.

That is, the aluminum and aluminum alloy plates for building members according to the present invention are rolled with rolls having roughened surfaces, and have a roughness of 25.4++ at least in the direction parallel or perpendicular to the rolling direction.
The maximum roughness Rmax within the measurement length of un (1 inch), that is, the highest peak Mo within the measurement length of 25.4 mm (
(see drawing) is 2 μm or more, and 25. above.
The number of peaks M with a height of 1.27 μm (50 microinches) or more within a measurement length of 4 mm (hereinafter simply referred to as the number of peaks M).
It is characterized in that the surface roughness is adjusted by the above-mentioned rolling rolls so that the number of particles is 25 or more.

Here, it is preferable to set the maximum roughness Rmax and the number of ridges M as large as possible, but if Rmax and the number of ridges M are excessively increased, the adjustment of the roll surface and the transfer ability during rolling. Since this may actually lead to a decrease in productivity due to the limitations of , it is appropriate to set RmaX to about 16 μm and the number of peaks M to about 150 as the upper limit of the sound variation.

In addition, the above aluminum and aluminum alloy plates include:
After rolling with a roughening roll, an alumite treatment is usually performed. In that case, in the present invention, the surface of the aluminum and aluminum alloy plate is roughened during rolling, and the directionality of the surface roughness is thereby sufficiently reduced, so that etching is not necessarily required in the process before the alumite treatment. However, in order to further reduce the unevenness, it is preferable to perform an etching process for a relatively short period of time before the alumite treatment.

[Example] Below, as an example, 7-?
I+/; 2h/, snoring (snoring field, 9 nm)
11. Table 1 shows the results of investigating the relationship between the height Rmax, the number of peaks M, and the directionality of surface roughness.

Inventive materials No. 1 to No. 9 in Table 1 were made such that R max and the number of ridges M in the direction parallel or perpendicular to the rolling direction were within the setting range of the present invention (R max ≧ 2 μm, number of ridges M ≧ 25). The rough surface shape was rolled and transferred using a roughening roll. Comparative material No. 2 was similarly rolled with a roughening roll, but Rmax and the number of peaks M were slightly smaller than the lower limit of the present invention. Furthermore, comparative material No.
1 and No. 3 were rolled with conventional DC rolls, and their n max and number of peaks M are considerably smaller than the lower limit of the present invention.

Test pieces were prepared from each invention material and comparative material, and each test piece was
% NaOH aqueous solution (liquid temperature: 60°C), invention material No. 1-
No. 9 and comparative material No. 1. The test piece taken from No. 2 was etched for 30 seconds, and the test piece taken from comparative material No. 3 was etched for 7 minutes, and then each test piece was etched with sulfuric acid alumite. For each test piece after alumite, the presence or absence of directionality in surface roughness was visually determined based on the evaluation criteria shown in Table 2.

As is clear from Table 1, in the invention materials, the directionality of surface roughness is generally reduced.

On the other hand, although comparative material No. 2 was rolled with a roughening roll, the directionality of the surface roughness could not be removed because Rmax and the number of peaks M were insufficient. Also, conventional DC
Comparative materials No. J and No. 3, which correspond to the plates, both have directionality, and in particular, the directionality of comparative material No. 3 has not been improved even though the etching time was lengthened. Further, when Rmax and the number of peaks M are excessively large, as in invention material No. 4, although directionality can be eliminated, sufficient mass productivity cannot be achieved.

Note that the above-mentioned tendency was the same not only for aluminum sheets but also for aluminum alloy sheets.

[Effects of the Invention] As explained above, in the present invention, the surfaces of aluminum and aluminum alloy plates for building members are roughened to some extent using a roughening roll, so that the surfaces of aluminum and aluminum alloy plates are roughened to some extent. It is possible to reduce the directionality of roughness, making it easier to color match products, and allowing for mixed vertical and horizontal placement. In addition, in the present invention, since the surface roughness of aluminum and aluminum alloy plates can be reduced in directionality using a roughening roll, the etching process can be omitted, and when etching is performed, the etching time can be reduced. It can significantly shorten the time and improve productivity.

[Brief explanation of drawings]

The drawings are diagrams schematically showing the surface properties of aluminum and aluminum alloy plates for building members. M...Mountain. Patent Applicant: Kobe Steel Oriyoshi Co., Ltd. Patent Attorney: Aohaku Ao and 2 others (1) Normal etching conditions (soaking time = 7 minutes) (2) See Table 2

Claims (1)

[Claims] (1) Rolled with a roll with a roughened surface, at least in a direction parallel or perpendicular to the rolling direction, 25.
The maximum roughness within the measurement length of 4mm is 2μm or more, and the height within the measurement length of 25.4mm is 1.27μm.
An aluminum or aluminum alloy plate for building materials, characterized in that the surface roughness is adjusted by the above-mentioned rolling roll so that the number of ridges of m or more is 25 or more.