JPH08158095A - Aluminum material and aluminum alloy material having linear pattern and production thereof - Google Patents

Abstract

PURPOSE: To develop an Al material excellent in designability and having a linear pattern by forming an anodic oxide film on the surface of the Al material, sealing the film, generating the longitudinal and lateral linear pattern cracks by heating and again covering the crack with an anodic oxide film. CONSTITUTION: An Al or Al alloy material is degreased and etched, and a current is applied with the material as an anode to form an anodic oxide film having >=6μm thickness on the surface. The oxide film is washed with hot water and sealed to <0.25g/dm<2> sealing degree and then heated to 150-575 deg.C to crack the sealed anodic oxide film in the longitudinal and lateral directions. The Al or Al alloy material having the cracked oxide film is again etched to form an anodic oxide film again, electrolytically colored or dyed, sealed and coated with a transparent paint or a colored paint to develop an Al or Al alloy material having a linear pattern on the surface, excellent in designability and decorativeness and having an irregular linear pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an aluminum material and an aluminum alloy material having an irregular line pattern on the surface,
And their manufacturing methods.

[0002]

2. Description of the Related Art Aluminum materials and aluminum alloy materials are widely used for building materials because they are lightweight, have excellent workability, corrosion resistance and surface treatment properties, and have appropriate strength.

FIG. 5 shows an example of a conventional aluminum material manufacturing method. In order to manufacture an aluminum material or an aluminum alloy material, first, an aluminum material or an aluminum alloy material is prepared (step 5
01), followed by pretreatment (treatment by degreasing, etching, and neutralization, or treatment by degreasing, chemical polishing or electrolytic polishing, and neutralization) (step 50).
2) Anodizing treatment is performed to form an oxide film on the surface (step 503), electrolytic coloring or dyeing (step 504), and washing with water or sealing treatment is performed (step 50).
5), a coating film is formed on the oxide film on the surface by a coating process (step 506). As a result, a coated composite film product of an aluminum material or an aluminum alloy material is obtained (step 507).

Despite the fact that aluminum is a chemically active substance, its excellent corrosion resistance is due to the protective action of the colorless and transparent oxide film purified on the surface. However, the oxide film that naturally forms in the atmosphere is 100 to 1
It is a very thin film of about 000 nm, and sufficient corrosion resistance cannot be obtained by itself. Therefore, conventionally, by forming a thick oxide film chemically or electrochemically, corrosion resistance is improved, and further wear resistance and decorativeness are improved. In the above example, the oxide film is formed by the anodizing treatment in step 503.

[0005]

However, when the thickness of the oxide film is 14 μm or more, when the sealing conditions are strong or the baking temperature of the coating is as high as 200 ° C. or more, the processing direction of extrusion or the like is increased. Since the crack 41 as shown in FIG. 4 was formed in the oxide film almost at right angles to the above, the product was considered defective. This is because the oxide film has a defect, so that the corrosion resistance is reduced and the appearance is also affected. Therefore,
In the prior art, it was necessary to pay attention to the thickness of the coating and the sealing conditions so that the coating would not crack during baking.

However, the inventors of the present invention, in the process of investigating various causes of cracking in the oxide film, can cause cracks in the oxide film to occur in the direction parallel to the processing direction. It has been found that an irregular pattern with high decorativeness can be obtained depending on the conditions for generating.

An object of the present invention is to provide a method for producing an aluminum material and an aluminum alloy material having a highly decorative and irregular line pattern.

[0008]

In order to achieve the above object, the present invention comprises a base material made of aluminum or an aluminum alloy, the base material having cracks filled with oxide on at least one of the front and back surfaces. Provided is an aluminum material or an aluminum alloy material, characterized in that the surface having the crack is covered with an oxide film.

Further, according to the present invention, a first oxide film forming step of forming an oxide film on the surface of a base material made of aluminum or an aluminum alloy, a heating step of heating to cause cracks in the oxide film, and further an oxide film. Second to form
The method for producing an aluminum material or an aluminum alloy material is provided.

The thickness of the oxide film formed in the first oxide film forming step is preferably 6 μm or more. The first oxide film forming step includes a first oxidation step of oxidizing the surface of the base material to form the oxide film, and a first sealing step of sealing the oxide film. The pore step is performed under the condition that the degree of sealing of the oxide film formed in the first oxidation step (JIS H ^8683-1979 ; based on a phosphoric acid-chromic acid solution immersion test) is 0.25 g / dm ² or less. The heat treatment process is performed at 150 ° C to 57 ° C.
It is desirable to include a step of heating at 5 ° C.

[0011]

The present inventors have found that the oxide film is irregularly cracked in the vertical and horizontal directions with respect to the processing direction due to the trade-off between the sealing condition and the heat treatment condition, as shown in FIG. It was found that a smooth line pattern 11 was obtained. It was also found that by coating the film cracking material again with a series of oxide film forming treatment steps, a coated composite film product having a pattern of film cracking traces without deterioration of corrosion resistance due to film defects can be obtained. It was Each step of the present invention will be described below. An example of the manufacturing method of the present invention is shown in FIG.

(1) First Oxide Film Forming Treatment In the present invention, first, an aluminum material or an aluminum alloy material is subjected to a first oxide film forming treatment. The first oxide film formation treatment is a treatment in which the material is pretreated to form an oxide film on the surface and seal the pores. In the example shown in FIG. 2, an aluminum material or an aluminum alloy material is prepared (step 201), pre-treated (step 202), and then anodized to form an oxide film on the surface (step 203). ), Seal (step 20)
4).

The aluminum material and aluminum alloy material used in the present invention may be any material as long as it is an aluminum and aluminum alloy material capable of forming an oxide film (preferably anodizing).

The pretreatment performed in step 202 is the same as the pretreatment for the surface treatment of general building materials. For example, the pretreatment is performed by performing degreasing, etching, and neutralization in this order, or by performing degreasing, chemical polishing or electrolytic polishing, and neutralization in this order.

As the anodizing treatment in step 203, an anodizing method used in the production of general building materials, for example, electrolytic treatment in a bath having a sulfuric acid concentration of 10% to 20% and a bath temperature of about 20 ° C. is used. A normal oxide film forming treatment method may be applied. However, since the thickness of the oxide film needs to be divided by heat treatment, it is desirable that the thickness be 6 μm or more. The thicker the oxide film, the sharper the line pattern in the subsequent regeneration treatment. This is because the thicker the oxide film, the larger the crack width of the film. Therefore, the thickness of the oxide film is more preferably 9 μm or more.

Although the sealing treatment is performed after the oxide film is formed, unlike the prior art, it is not necessary to color the surface before the sealing treatment in the present invention. As the sealing treatment, a sealing (washing with water) treatment used at the time of manufacturing a general building material, for example, 70 ° C in water
A treatment of immersing at 100 ° C. for 5 minutes or more may be performed. In addition,
The degree of sealing is preferably 0.25 g / dm ² or less. If the sealing degree exceeds this value, vertical and horizontal cracks cannot be sufficiently generated in the oxide film.

(2) Heat Treatment After an aluminum material or an aluminum alloy material (hereinafter, simply referred to as an aluminum member) having an oxide film sealed on the surface in this manner is produced, in the present invention, heat treatment is performed to form an oxide film. To crack (step 20)
5). In order to form cracks in the oxide film in the vertical and horizontal directions, as a heat treatment (step 205), the aluminum member is treated with 150
It is necessary to hold at 7 to 575 ° C for 7 minutes (preferably 10 minutes) or more.

When the heat treatment temperature is 150 ° C. to 300 ° C., the degree of sealing obtained by the sealing treatment in step 204 needs to be 0.05 g / dm ² or less.
This is because if the degree of sealing is large, sufficient cracks cannot be generated in the oxide film unless heat treatment is performed at a high temperature. However, when the heat treatment temperature is set to 300 ° C. or lower, the width of the crack is too small, so that the crack becomes unclear due to the regeneration treatment performed later, and all the film crack traces (line patterns) disappear. There is.

When the heat treatment temperature exceeds 300 ° C. (30
(0 ° C. to 575 ° C.), even if the sealing degree obtained in step 204 exceeds 0.05 g / dm ² , vertical and horizontal cracks can be generated in the oxide film. When the treatment is performed at a temperature higher than 300 ° C., the coating crack traces (line patterns) remain even after the subsequent regeneration treatment, and a coated composite film product having a clear line pattern is obtained. However, if the degree of sealing is too strong (0.03 g / dm ² or less), the film cracks become too fine and the sharpness of the pattern is slightly lost.

When the heat treatment is carried out at 300 ° C. or higher, the traces of the film cracks clearly remain even after the regeneration treatment. The higher the heat treatment temperature is, the larger the width of the film cracks due to the thermal expansion is. ) It is thought that this is because the crack reaches the fabric part. This is because it is considered that the cracks in the cloth portion are further melted during the recycling process and the line pattern is emphasized, so that the crack becomes clear.

As described above, in order to obtain a good line pattern, the higher the heat treatment temperature in step 205, the better. However, if it exceeds 575 ° C, it cannot be put to practical use. If the temperature is lower than 450 ° C, the aluminum (or aluminum alloy) will be annealed, and the material strength will decrease. On the other hand, if the temperature exceeds 530 ° C., coarsening of crystal grains and internal eutectic melting occur, resulting in deterioration of quality and easy change of material. Therefore, step 205
The heat treatment temperature in is preferably 450 to 530 ° C.

In the present invention, an aluminum material or an aluminum alloy material having a clear line pattern and a coating composite film performance satisfying the JIS H 8602 standard is referred to as a "good line pattern coating composite film product".

As the heat treatment furnace, an artificial aging treatment furnace for extruded shapes and a homogenization treatment furnace for ingots (billets) may be used. In addition, the heat treatment of step 205 is performed at 150 ° C.
When the treatment is performed at a temperature of about 200 ° C., the treatment for about 1 to 10 hours can also serve as the artificial aging treatment of the material. In addition, the heat treatment of step 205 is performed at 450 ° C.
In the case of performing the above, the solution treatment of the material is also performed by performing the treatment for about 10 minutes to 3 hours. In this case, artificial aging treatment may be performed later.

(3) Regeneration Treatment (Second Oxide Film Forming Treatment) Next, a regeneration treatment (second oxide film formation) is performed by forming an oxide film again on the surface of the aluminum member on which the crack has occurred. Process). The regeneration treatment is a treatment in which an aluminum member having an oxide film with cracks is pretreated, an oxide film is again formed on the surface, and the aluminum member is sealed. In the example shown in FIG. 2, after the aluminum member having the oxide film cracked in step 205 is pretreated (step 20
6) Anodizing treatment is performed to form an oxide film on the surface (step 207), electrolytic coloring (or dyeing) is performed (step 208), sealing is performed (step 204), and coating is performed (step 210). . As a result, a coated composite film product of an aluminum material or an aluminum alloy material having a vertical and horizontal line pattern on the surface is obtained (step 211).

Pre-processing in reproduction processing (step 20)
It is desirable to perform step 6) because the crack can be expanded by melting. The pretreatment in step 206 may be the same as the pretreatment at the time of the surface treatment of the general building material, as in step 202. However, the etching is preferably performed by immersing in a sodium hydroxide aqueous solution having a concentration of 5% to 15% at a bath temperature of 40 ° C. to 55 ° C. for 6 minutes or more. This is because the oxide film formed by the first oxide film formation treatment and the aluminum or aluminum alloy cloth portion can be melted in a total amount of 10 μm or more. As a result, the surface of the crack is melted, and as a result, the crack further spreads, so that the trace of the film crack (line pattern) can be made clear.

For the anodizing treatment (step 207) in the regenerating treatment, the same treatment as the anodizing treatment in the general aluminum building material manufacturing method can be applied.

The coloring in the coloring process (step 208) may be carried out according to the design requirement, and electrolytic coloring or dyeing is a general method, but it is not always necessary if there is no design requirement. .

Sealing process in the regenerating process (step 20)
9) may be the same as the sealing (washing) treatment in the general method for manufacturing aluminum building materials, for example, 70 ° C to 1 in water.
Immersion treatment may be performed at 00 ° C. for 5 minutes or more.

In the coating process (step 210), either transparent paint or colored paint can be used. The transparent paint is mainly applied for the purpose of improving the corrosion resistance, and it hardly changes in design. On the other hand, a colored coating generally has a high concealing property and is therefore difficult to apply to the present invention. However, as long as it is a paint called “color clear” which has a good light transmission property or a paint in which the pigment concentration in the paint is low and the pigment particle size is made small to reduce the hiding property, the coating treatment in the present invention Can be used for.

As described above, in the present invention, the formed oxide film is heat treated to form a line pattern due to cracks, and the cracks are again covered with the oxide film, so that the aluminum member can be designed. You can add a high line pattern. Therefore, according to the present invention, the product is not defective even if the oxide film is thickened, and it is possible to mass-produce an aluminum material and an aluminum alloy material having an irregular line pattern with high designability.

Also, in applying this irregular pattern,
Since no special equipment is required and the production line that has been used conventionally can be used, it has an excellent appearance and a thick oxide film at a production cost that is not much different from the conventional production cost. Therefore, it is possible to manufacture an aluminum material and an aluminum alloy material having excellent corrosion resistance, wear resistance, and decorativeness.

Since the aluminum material and aluminum alloy material of the present invention are excellent in decorativeness, they can be widely used in building materials such as window frames and doors, cooking utensils such as pots and kettles.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. Although the following examples are for aluminum materials, similar results were obtained for aluminum alloy materials.

<Example 1> 70 mm x 150 mm A6
063S (JIS name; "A" represents aluminum and "S" represents extruded profile) under the conditions shown in Table 1 (first oxide film formation). Treatment), heat treatment, and regeneration treatment (second oxide film formation treatment), and the state of the film crack after the heat treatment and the state of the film crack trace (line pattern) after the pretreatment in the regeneration process were investigated. Table 2 shows the results.

In this example, 30 aluminum materials were prepared. The sealing treatment (washing treatment) in the first oxide film forming treatment is shown in Table 1 (a-1) to (a-).
It was performed by immersing in pure water under the five conditions of 5). As a result, five kinds of test materials each having a different degree of sealing were obtained. The sealing degree of each is also shown in Table 1. The five types of test materials (six pieces each) thus obtained are shown in Table 1 (b-1) to (b), respectively.
Heat treatment was performed under the six conditions of -6). As a result, the conditions for the sealing treatment and / or the heat treatment are different from each other.
Sheets of test material were obtained. The pretreatment in the second oxide film formation treatment was performed by performing degreasing, etching, and neutralization in this order. The etching conditions are as shown in Table 1.

[0036]

[Table 1]

[0037]

[Table 2]

From the results of this example shown in Table 2, under the condition that the degree of sealing obtained is as weak as about 0.2581 g / dm ² , vertical and horizontal line patterns are not formed at any heat treatment temperature, and the sealing is prevented. It can be seen that vertical and horizontal line patterns are generated as the degree increases or the heat treatment temperature increases. When the degree of sealing is quite strong, the heat treatment temperature can cause vertical and horizontal cracks in the oxide film even in a low temperature region.

<Example 2> The thickness of the oxide film is about 15 μm.
The test material and the test material having the oxide film thinned to about 6 μm were subjected to the treatment after the sealing treatment in the same manner as in Example 1, and the shape of the cracks in the oxide film and the pattern after the pretreatment were performed. When the state of No. 2 was investigated, there was no great difference in the tendency of the relationship between the degree of sealing and the heat treatment temperature and the state of cracks. However, when the oxide film is thick, the crack width of the film becomes large,
The line pattern became clearer than in Example 1. Also,
On the contrary, when the oxide film is thin, the crack width of the film becomes smaller,
The line pattern was slightly blurred as compared with Example 1.

<Example 3> The pretreated test material obtained in Example 1 after the regeneration treatment was subjected to the anodization treatment of the regeneration treatment (second oxide film formation treatment), and further silver, bronze, When the product was colored with a stainless steel color, etc., and was applied with clear gloss by electrodeposition coating, a clear line pattern-coated composite film product was obtained.

In Example 1, the appearance of the test material which was subjected to the pore-sealing treatment at 80 ° C. for 7 minutes under hot water washing and the heat treatment at 500 ° C. for 2 hours was shown in FIG. Shown in.
In addition, the rugged material treated in the same manner as this test material is subjected to pretreatment for regeneration treatment, anodized, stained with a stain color, and subjected to clear gloss coating by electrodeposition coating. The appearance is shown in FIG.

<Example 4> 70 mm x 150 mm A1
100P (JIS name; "A" represents aluminum and "P" represents rolled material)
Under the conditions shown in Table 3, a surface treatment (first oxide film forming treatment), a heat treatment, and a regenerating treatment (second oxide film forming treatment) are added, and the state of film cracking after the heat treatment and the regenerating treatment The state of the film crack trace (line pattern) after the pretreatment was investigated. The results are shown in Table 4.

In this example, 18 aluminum materials were prepared. The conditions of the anodizing treatment in the first oxide film forming treatment are (c-1) to (c-) shown in Table 3.
Two kinds of conditions of 2) were used, and 9 sheets were performed under each condition. As a result, two types of test materials having an oxide film thickness of about 10 μm and about 20 μm were obtained. Next, the sealing treatment (washing treatment) in the first oxide film forming treatment, which was performed three times for each of the two types of test materials, is shown in Table 3 (d-1) to (d-). It was performed by immersing in pure water under the three conditions of 3). As a result, three kinds of 6 types of test materials having different sealing degrees were obtained. The sealing degree of each is also shown in Table 3. The six types of test materials (three sheets each) thus obtained were heat-treated under the three types of conditions (e-1) to (e-3) shown in Table 3, respectively. As a result, the thickness of the oxide film,
Eighteen test materials with different conditions of sealing treatment and / or heat treatment were obtained. The pretreatment in the subsequent second oxide film forming treatment was performed by performing degreasing, etching and neutralization in this order. Table 3 shows the etching conditions.
As shown in.

[0044]

[Table 3]

[0045]

[Table 4]

As can be seen from the results of this embodiment shown in Table 4, the same results can be obtained regardless of the thickness of the oxide film formed by the first oxide film forming step of 10 μm and 20 μm. Was obtained.

When no sealing treatment is performed (the sealing degree is about 0.
3801 g / dm ² or 0.3755 g / dm ² ) was weak), it was not possible to generate vertical and horizontal line patterns by heat treatment at any temperature regardless of the thickness of the oxide film.

When the sealing treatment is performed by immersing in pure water at 80 ° C. for 7 minutes (sealing degree is about 0.158).
1 g / dm ² or 0.1382g / dm ²⁾ is even oxide film by any film thickness, it was not possible to produce a line pattern of vertical and horizontal by heat treatment 200 ° C.. However, in this case, a line pattern could be formed at a temperature of 480 ° C. or higher.

Further, when the sealing treatment is carried out by immersing in pure water at 100 ° C. for 7 minutes (sealing degree is about 0.0
Strong and 199g / dm ² or 0.0211g / dm ²⁾
It was possible to generate vertical and horizontal irregular line patterns regardless of the thickness of the oxide film and the heat treatment at any temperature. However, when the heat treatment was carried out at 200 ° C., the vertical and horizontal line patterns became unclear due to the pretreatment in the second oxide film forming step regardless of the thickness of the oxide film.

Therefore, even after the second oxide film forming step, a clear pattern remains because the sealing conditions are 80 ° C. and 7 minutes regardless of the thickness of the oxide film. The above was the case and the heat treatment temperature was higher than 200 ° C.

<Example 5> The patterned test material obtained in Example 4 (which has been pretreated in the second oxide film forming step) was subjected to anodizing treatment and shown in Table 5 by a roll coater. When each of the color clears shown was applied in a thickness of about 10 μm, a coated composite film product having a clear line pattern for each color was obtained.

[0052]

[Table 5]

[0053]

As described above, according to the present invention, it is possible to mass-produce an aluminum material and an aluminum alloy material having an oxide film having an irregular line pattern with high design and decoration.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a pattern on a surface of an aluminum material and an aluminum alloy material according to the present invention.

FIG. 2 is a flow chart showing an example of a method for producing a coated composite film product of the present invention.

FIG. 3 is an external view showing a line pattern on the surface of an aluminum material according to the present invention.

FIG. 4 is an explanatory diagram showing cracks that have occurred in an oxide film in the conventional technique.

FIG. 5 is a flow chart showing an example of a method for producing a coated composite film product according to the prior art.

[Explanation of symbols]

1 ... Vertical and horizontal line patterns due to cracks in oxide film, 41 ... Cracks in oxide film.

Claims (7)

[Claims] 1. A first oxide film forming step of forming an oxide film on a surface of a base material made of aluminum or an aluminum alloy; a heating step of heating to cause cracks in the oxide film; and further forming an oxide film. And a second oxide film forming step for producing an aluminum material or an aluminum alloy material. 2. The method for manufacturing an aluminum material or an aluminum alloy material according to claim 1, wherein the thickness of the oxide film formed in the first oxide film forming step is 6 μm or more. 3. The first oxide film forming step according to claim 1, wherein the first oxide step is a step of oxidizing the surface of the base material to form the oxide film, and the first step of sealing the oxide film. In the sealing step, the degree of sealing of the oxide film formed in the first oxidation step (JIS H ^8683-1979 ; based on a phosphoric acid-chromic acid aqueous solution immersion test) is set to 0. 0.25g
/ Dm < ² > or less, and the said heat processing process includes the process of heating at 150 degreeC-575 degreeC, The manufacturing method of the aluminum material or aluminum alloy material characterized by the above-mentioned. 4. A first oxide film forming step of forming an oxide film having a thickness of 6 μm or more on a surface of a base material made of aluminum or an aluminum alloy, and a heating step of heating to cause cracks in the oxide film. And a method for manufacturing an aluminum material or an aluminum alloy material. 5. A base material made of aluminum or an aluminum alloy, wherein the base material has a crack filled with an oxide on at least one of the front and back surfaces, and the surface having the crack is covered with an oxide film. An aluminum material or an aluminum alloy material. 6. The aluminum material or aluminum alloy material according to claim 5, wherein a part of the crack is parallel to the processing direction. 7. The aluminum material or the aluminum alloy material according to claim 6, wherein at least a part of the remaining portion of the crack is perpendicular to the processing direction.