JPH01306575A - Aluminum or aluminum alloy material having corrosion resistant laminated coating film - Google Patents

Abstract

PURPOSE:To obtain an Al material having superior corrosion, weather and heat resistances by successively forming an inorg. oxide coating film as an intermediate layer and a specified amt. of a hard coating film consisting of Si and O on an Al material. CONSTITUTION:An inorg. oxide coating film as an intermediate layer and about 15-300mg/dm<2> hard coating film consisting of Si and O are successively formed on an Al or Al alloy material. The surface of the hard coating film is composed of fine grains of about 0.005-0.05mum grain size. The intermediate layer is made of about 2-8mg/dm<2> oxide hydrate. The layer may be an inorg. oxide coating film contg. a salt of Si, Cr, Zr, Ti, Mo, V or W. An Al or Al alloy material having superior corrosion, weather and heat resistances can be obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field J] The present invention relates to aluminum or aluminum alloy materials (hereinafter referred to as aluminum materials) used in various fields such as architecture, machinery, automobiles, and electricity. .

[Prior Art and its Problems, J] Conventionally, when aluminum materials are used for automobile wheels, for example, depending on the structure of the wheel,
It is classified into three types: piece, 2 piece, or 3 piece. A one-piece type wheel is made of a wheel rim, a disk, etc. as an integral structure by casting or forging, and is usually made of Al-8i alloy.

On the other hand, in a two-piece or three-piece type wheel, the wheel and the disc are manufactured separately, and the wheel rim is formed by roll forming or drawing 9 from a wrought material manufactured by rolling or extruding an aluminum alloy. (spinning molding), made by puff polishing, and the material is JIS^5052, JIS^515 for boat fishing.
It is made of an Al-Mg alloy such as No. 4. Further, the disk is made by casting, forging, etc., and the material used is A1-Mg-3i series or Al-3i series aluminum alloy such as JIS 86 to 61.

These wheel rims and discs are connected by bolts or welding to form an integral wheel.

After forming and processing aluminum alloy wheels and their components into a predetermined shape, they are usually plated, anodized, painted, electrolytically colored, or dyed, such as white, white, etc.
It can be finished in various colors such as silver, black, and goal V.

In terms of its use, an inexpensive surface treatment method that has corrosion resistance, weather resistance, shine, and heat resistance is desired.

Conventionally, there have been many cases in which the surface has been chrome plated, that is, aluminum alloy wheels or their parts have been zincate treated and then Cu, Niv? 10～
Prime the base plate to a thickness of 50 μω, and apply 0.2 to 0.0 μm on top.
The mirror surface is obtained by plating 3μ thick Cr, but in this case there is the following good luck, α. That is, (1) The corrosion resistance and weather resistance are not good for a thick film of about 10 to 50 μl (white clouding occurs on the surface after use).
It is more expensive than anodizing and painting.

(2) When applied to a one-piece wheel, the straightening process tends to be incomplete, the adhesion between the wheel base and the plating film deteriorates, and the plating film peels off. ■When applied to 2-piece or 3-piece wheels, the film will peel off due to the heat generated when welding the rim and disc.

In addition, in order to improve the brightness and corrosion resistance of the wheel surface, after the wheel surface has been subjected to puff polishing and/or chemical Pp polishing, a clear coating is applied. Resin painting is done. In such cases, since the film is soft, scratches are easily generated on the surface, and there are problems in that the film turns yellow when heated during welding or exposed to ultraviolet rays in the atmosphere.

On the other hand, current surface treatments that improve brightness include puff polishing, chemical polishing, and anodic oxide coating, but in these cases, the coating may be damaged due to the thermal effects during welding. Cracks occur and there are problems with the appearance.

In addition, in order to eliminate film defects after anodization, improve surface smoothness, and give shine, aluminum alloys are made of materials with reduced content of impurity elements such as Fe and Si. (Japanese Patent Laid-Open No. 62-23973) has been proposed, but these materials require high purity metals, resulting in high costs.

Furthermore, in the silicate coating treatment proposed in Japanese Patent Publication No. 57-43634, etc., although the heat resistance and weather resistance are good, the silicate compound increases the baking temperature after application to 240°C or higher. However, there are also problems in that the mechanical properties of the aluminum material deteriorate and the film tends to become cloudy. Furthermore, other problems with silicate coatings such as those mentioned above include the fact that the film is brittle due to the formation of numerous pores, resulting in poor corrosion resistance and poor adhesion to the substrate. It is known that corrosion resistance during outdoor use or film adhesion in areas subject to deformation stress is poor.

[Disclosure of the Invention 1 The present invention was made at the stage of conducting research on several of the above-mentioned problems one by one. Its main feature is an aluminum material having a corrosion-resistant composite coating consisting of a hard coating of the system consisting of 81 and O.
Furthermore, (2) an aluminum material having a corrosion-resistant composite coating according to claim 1, wherein the corrosion-resistant hard coating is a hard coating exhibiting fine grains of about 0.005 to 0.05 μm; Yes, (3) The inorganic oxide film of the intermediate layer is about Z~Sag/de
An aluminum material having a corrosion-resistant composite film according to claim 1, characterized in that the film is a hydrated oxide film of n2, and (4) the inorganic oxide film of the intermediate layer is composed of Si%Cr, Zr.
, Ti, Mo, V, and W, and contains one or more of the group salts or ammonium salts consisting of -, Ti, Mo, V, and W, and the amount of the coated film is about 0.0% in terms of the above elements.
The present invention is characterized by an aluminum material having a corrosion-resistant composite film having a corrosion resistance of 0.02 to 1.5 mg/dm2.

Hereinafter, to further explain the structure of the present invention, the material of the surface layer of the aluminum material having the corrosion-resistant composite film of the present invention does not contain any alkali metal elements etc. as a main component and is simply composed of Si and VO elements. The particle size of the film is approximately 0.
S+Ozz exhibiting fine grain size of 0.005 to 0.05μ
! % hard coating. These films can be formed by various methods, examples of which are as follows.

For example, after applying a solution of an organic silica compound dispersed or dissolved in an organic solvent such as ethyl alcohol or isopropyl alcohol to the surface of an aluminum material coated with a hydrated oxide film, this solution is applied to prevent the mechanical properties of the aluminum material from deteriorating. Baking conditions such as 10% or less of before heating, for example, 20
It is sufficient to bake at 0℃ for 10 minutes.The baking conditions are based on the composition of the aluminum material (Al-Fe-8i system, AI-Mg
M, Al-3i system, A1Mn system, Al-Mg-8i system e
tc), tempered condition! ! ! Although it is not unambiguously determined by the number 1, etc., baking temperatures of about 220° C. or higher are not preferable because the mechanical properties of the aluminum material will deteriorate by more than 10%.

The organic silica fruit compound film is then baked through a baking process.
The composition is transformed into a 5i02-based hard coating.
．． Since it becomes a fine granular film with m-density of 05 μm, the corrosion resistance in the usage atmosphere is extremely excellent, and the brightness of the aluminum material is maintained for a long time. In addition, the 5in2 hard coating is
The organic silica compound solution may be applied once, or may be applied two or more times. If the amount of the above-mentioned S+OzX% hard coating is less than 15B/d+a2 (equivalent to approximately 0.5μ ring thickness), the appearance will become an interference film and rainbow colors will appear, and the smoothness will be poor, which is not desirable. amount is 30
If the amount exceeds 0.0IIg/d2 (approximately 10μ - equivalent to film thickness), the particle size of the coating will exceed 0.05μ and abnormal precipitation will occur, resulting in loss of brightness on the aluminum material surface and poor adhesion of the coating. This is undesirable as it also deteriorates and becomes more prone to cracking. Further, it is desirable for the surface of the aluminum material itself to have a center line average roughness (RaJ of about 0.2 μm or less) from the viewpoint of brightness.

Next, a hydrated oxide film as an intermediate layer on an aluminum material is usually formed by treating it with a neutral or basic solution, for example, by immersing it in boiling pure water. There are boehmite-based films, which are formed by adjusting P to 9 to 12 with various basic substances such as triethanolamine, 7-ammonia, or caustic ZORG, and treating with a pure aqueous solution.

Furthermore, when a predetermined amount of one or more oxidizing agents such as hypohalites, halides, halogenates, etc. is added to the solution for forming a hydrated oxide film, The adhesion of the subsequent secondary coating can be further improved.

The hydrated oxide film formed as described above is
The film amount is about 2 to 8 IIIg/dm 7 (equivalent to about 0.1 to 0.3 μ pupillary membrane thickness), more preferably about 5 to
6+*g/dm" is desirable.

In other words, when the amount of hydrated oxide film is less than 2 mg/dJ, the effect of improving adhesion when forming a composite film is small, and conversely, when it exceeds 8 Tag/daa2, the workability etc. of the composite film deteriorates. This results in a decrease in corrosion resistance and the like.

Furthermore, as an inorganic oxide film as an intermediate layer, depending on the final use of the aluminum material, 5i1Cr, 'Z
A method of processing with a solution containing one or more metal salts or ammonium salts of the following elements: r, Ti, Mo, V, and W can also be adopted.

One type of these metal salts or ammonium salts.

By treating the aluminum material with the solution contained above, the coating amount is 0.02 to 1.5-g/d in terms of the above elements.
+e2 (equivalent to about 0.005 to 0.3μ+6 film thickness) oxide film is formed and then treated with an organic silica compound solution to further improve the performance of the resulting corrosion-resistant composite film.

That is, the amount of the oxide film is 0.02 mg in terms of the above elements.
/dra2, the adhesion improvement effect of the composite film cannot be expected, and conversely, if the oxide film exceeds 1.5 g/dJ in terms of the above elements, the temperature at 150°C
At higher temperatures, the moisture content in the film decreases and the high temperature resistance deteriorates. The aluminum material having the corrosion-resistant composite film of the present invention formed as described above can be made into (1) a bright aluminum material having smoothness equivalent to that of chrome plating.

■ Corrosion resistance is equivalent to a normal anodic oxide film with a thickness of about 20 μm or more. ■ The film does not discolor or change in quality due to heat from welding or ultraviolet rays, and is an aluminum material with good heat resistance and weather resistance. ■Production costs can be reduced because low-purity aluminum materials can be used.

■The composite film will not peel off even when subjected to repeated stress, such as on wheel rims.

■By adding a desired pigment or colorant, such as titanium white or titanium black, to the organic silica compound solution, it is possible to create an appearance that matches the intended use of the aluminum material. can demonstrate.

Next, examples of the present invention will be described in detail.

[Example 1 Example 1 MgO, 8wt%, FeO, 2+++t%, Cu 0
．． 03wt%, S i O, 5wt%, Mn, Ti, C
An A1Mg-3i aluminum alloy containing r and Zn of 0 and 02wt% or less, the remainder A1 and unavoidable impurities, was made into a predetermined extruded material, buffed, and heated to about 98°C for 31 hours.
g sodium hypochlorite aqueous solution (concentration: 200pp
m, PH: 10.5> to form a hydrated oxide film of about 6 B/dm2 on the surface of the aluminum alloy material.

Thereafter, it was immersed in an organic silica compound paint (H5-K manufactured by Sunroof Co., Ltd., solid content concentration: 15 wL%) diluted with isopropyl alcohol, and baked at 200°C in the air for 20 minutes to dry. On the surface of the aluminum alloy extrusion material,
A 5in2 hard coating was formed with a thickness of about 50 ωg/d*2.

Example 2 M) (2.5 wt%, Fe O, 18 wt%,
Cu0.07wt%, Si0.1wt%, Mn5Ti
A wheel rim material made of an Al-Mg-based aluminum alloy containing 0.02wt% or less of Cr and Zn each, and the balance A1 and unavoidable impurities is molded into a predetermined rim, and then processed into a weak alkaline material adjusted to approximately 50°C. Am treatment was carried out in Kuroiso sodium phosphate aqueous fi (concentration: 2-L%, Nirite Clean M4 manufactured by Kyoei Yushi Co., Ltd.).Then, the aluminum material was washed with water, and No. 1 water with a concentration of 51% was added to the lath soluble fi. (
PH12.3) at a temperature of about 80°C. Approximately 0.2 + a) H/d12 by Si exchange on the surface of the aluminum material.
A silicon-based oxide film was obtained.

Thereafter, as in Example 1, an organic silica compound paint (product of Sunroof Co., Ltd., I
ts-, solid content concentration: 15wL%) to coat the aluminum alloy rim surface with a 5ho2 hard coating of about 50%.
0mg/dm2 was formed.

Example 3 Fe0.3wt%, SiO, 1wt%, Mn, Ti
An aluminum material containing 0.02III% or less of each of Cr, Cr, and Zn, and the balance being AI and unavoidable impurities was rolled to a predetermined thickness using a gloss roll. After degreasing the aluminum material with an organic solvent, the temperature is 35-40'C, PH2.7
The sample was immersed for 15 seconds in Bonderite #3751 (manufactured by Nihon Baru Ising Co., Ltd.) which had been adjusted to

A Ti-based oxide film of 0.03 B/dm2 was formed on the surface of the aluminum material by Ti exchange, and a 5iOz-based hard film was further applied in the same manner as in Example 1 to a coating amount of about 50+ og.
/dm2 was formed.

Example 4 In Example 3, instead of forming a Ti-based oxide film, the oxide film on the surface of the aluminum material was replaced with Aronone #401.
(Rohon Paint Co. product, concentration: 2.5-1%) and Aronone #45 (Nippon Paint Co. product, concentration: 0.35w
Cr-based oxide film obtained by spraying with a phosphoric acid chromate treatment solution containing (film amount C: approximately 0.5 B/d in terms of
A corrosion-resistant aluminum fin material was obtained by carrying out the same procedure except for forming +a2), and further forming about 50 mg/dm2 of an S i 02-based hard film on the surface of the aluminum material.

Example 5 In Example 31, instead of forming a Ti-based oxide film, a Zr-based oxide film was obtained by immersing the oxide film on the surface of the aluminum material in a 1% zirconium heptanide bath at a temperature of 60 to 65°C. (Coating ji: about 0.1 B/da+2 in terms of Zr) was carried out in the same manner as in step 1, and a 50 mg/Jm2 SiOz-based hard coating was formed on the surface of the aluminum material.

Example 6 In Example 3, instead of forming a Ti-based oxide film, an MO-based acid oxide film rQji was obtained by immersing the oxide film on the surface of the aluminum material in a 1% sodium molybdate bath at 60 to 65°C. :No exchange g Te0. io+g/da”
) and 5'l- were all performed in the same way, and further 5 (5 in2 of hog/dm2) was formed on the surface of the aluminum material.
A hard coating was formed.

Example 7 In Example 3, instead of forming a Ti-based oxide film, the oxide film on the surface of the aluminum material was immersed in 1% ammonium vananoate at a temperature of 60 to 65°C. Amount: 0.05 ψg/dm2 (converted to 2) was carried out in the same manner, and a Si○2 hard film of 50 mg/d+a2 was further formed on the surface of the aluminum material.

Example 8 In Example 3, instead of forming a Ti-based oxide film, a W photo-oxidation film (film) obtained by immersing the oxide film on the surface of the aluminum material in a 1% sodium tungstate bath at a temperature of 60-65° Amount: Approximately 0.05mg/dm' in terms of W)
A 5i02-based hard coating of 50 g/d 2 was further formed on the surface of the aluminum material.

Example 9 Mg4, 5mt%, FeO, 1wt%, Cu 0.
After processing an Al-Mg-based aluminum material consisting of 0.07wt%, Si0.1+ut%, Mn, T1, Cr and Zn of 0.02...L% or less, the balance A1 and unavoidable impurities into an aluminum disk material of a predetermined shape. , Rareanong solution (product of Sunrare, solution whose main component is silicate)
It was immersed in water at 80°C. After washing with water and drying, an S1-based oxide film of approximately 1.56/dm2 in terms of Si was formed on the surface of the aluminum material.

Then, the same organic silica compound paint as in Example 1 was applied and baked at 200° C. in the air for 20 molecules n'+.

This coating-baking process was repeated for 5 cycles to form a 5in2 type hard film of about 290 mg/c1 m2 on the surface of the aluminum material to form a magnetic disk user 1 base.

Example 10 In Example 1, after forming a water conservation oxide film on an aluminum plate material (plate thickness 0.2 m/m) with the same composition, the solid content concentration was 5.
% organic silica compound paint [Sunroof Co. product, ll
54, raw material 'e, (solid content 15 wt%) diluted with isofloyl alcohol] was carried out in the same manner, and 15 mg of SiO□-based hard film was applied to the surface of the aluminum material.
/da+2 was formed to obtain an aluminum plate for planographic printing.

Example 11 In Example 2, instead of forming the S1-based oxide film, the oxide film on the surface of the aluminum material was coated with 2% aronone #.
Cr-based oxide film obtained by immersion in 1000 (Nippon Paint Co., Ltd. product) solution (approximately 0.4a+g in terms of film amount 2 Cr)
/cl+++2) was formed.

Thereafter, an organic silica compound paint (product of Toshiba Silicone Co., Ltd., Silicone Bartco) XR-31, solid content concentration: 3 (ht%) diluted with isopropyl alcohol, was spray applied to the surface of the aluminum material, and
Baked at ℃ for 20 minutes. 5iO on the surface of the aluminum material
21? A S hard coating of approximately 80 B/dm2 was formed and used as an automobile wheel rim material.

Comparative Example 1 The application of organic silica compound paint and the baking process were performed 7 times in the same manner as in Example 1, and a hard Sin-based film was applied to the surface of the aluminum material at a rate of about 330 B/d.
+++' was formed.

Comparative Example 2 A Sio2 hard film was applied to the surface of the aluminum material in the same manner as in Example 1 except that an organic silica compound paint diluted to a solid content of about 2 wt% was applied.
0B/dm2 was formed.

Comparative Example 3 The same procedure as in Example 1 was carried out except that the water conservation oxidation film treatment was omitted.

Comparative Example 4 In Example 1, instead of applying an organic silica compound paint to form a SiO□ hard film, an anodized film having a thickness of about 6 μm was formed on the surface of the aluminum material.

Comparative Example 5 The same procedure as Comparative Example 4 was carried out except that the anodized film in Comparative Example 4 was made to have a pupil of about 15μ.

Comparative Example 6 In Example 1, instead of applying an organic silica compound paint to form a SiO2 hard film, a zincate treatment was performed to form a zinc-substituted film, and then a semi-gloss N
I-plated, glossy Ni-plated and 10μI11 each.
After that, Cr plating (0
, 2 μl) was generated.

Comparative Example 7 In Example 1, instead of applying an organic silica compound paint to form a SiO2 hard film,
, acrylic-melamine resin (Nippon Paint Co., Ltd. UX80-1
19) was applied to form a film.

Comparative Example 8 In Example 1, instead of applying an organic silica compound paint to form a SiO2 hard film, a sodium silicate solution was applied, which was then dried at 30°C, and then baked at 250°C. , acid treatment, and water washing to remove metal ions in the film and form micropores.

Furthermore, the surface of the aluminum material is again coated with a sodium silicate solution to fill the micropores, and then dried at 30°C.
Baked at 250°C, treated with acid, washed with water, and applied a sodium silicate compound to the surface of the aluminum material at approximately 30 mB/dω.
2 were formed.

[Characteristics 1] For each product obtained on each side above, the results of investigating the film amount, corrosion resistance, weather resistance, heat resistance, brightness, and film adhesion are shown in the table.

In addition, it is based on JIS 118681, and CA
Changes in appearance after SS test (1681+r) were investigated using rating numbers. Weather resistance is based on appearance change after atmospheric exposure test (6 months, Susono City), and heat resistance is based on heating during welding. After heating at 400° C. for 20 minutes, the surface was checked for discoloration and film cracks.

The brightness was determined by measuring the surface reflectance in accordance with JIS D5705, and the coating adhesion was determined by measuring the surface reflectance in accordance with JIS K5400.
An impact test was conducted to examine cracking and peeling of the paint film.

As shown in the table, even if a corrosion-resistant composite coating is provided,
When the film is too thick, as shown in Comparative Example 1, the appearance and heat resistance are poor, and even the adhesion is poor. Conversely, if the film is too thin, as shown in Comparative Example 2, the appearance will be poor and the corrosion resistance and weather resistance will also be poor.

On the other hand, when configured as in the present invention, the above drawbacks are not observed. In other words, as can be understood from the comparison with the table and examples, when the Si○2-based hard coating is subjected to surface treatment, not only the adhesion of the hard coating is improved, but also the corrosion resistance is further improved. It is clear from a comparison with Comparative Example 3 and Example 10 that

In addition, the aluminum material with the composite film of the present invention has superior properties in terms of appearance, corrosion resistance, weather resistance, heat resistance, etc. compared to the aluminum material with the anodized film shown in Comparative Examples 4 and 5. Furthermore, it is much superior to the Menki film shown in Comparative Example 6 and the organic coating film shown in Comparative Example 7, so it is used in architecture, machinery, transportation, electronics, electricity, and other fields. Its use as an industrial material is extremely effective.

Claims (4)

[Claims] (1) An intermediate layer consisting of an inorganic oxide film and approximately 15 to 3
An aluminum or aluminum alloy material having a corrosion-resistant composite coating consisting of a hard coating of Si and O at a concentration of 00mg/dm^2. (2) The surface of the hard coating is approximately 0.005 to 0.05 μm
An aluminum or aluminum alloy material having a corrosion-resistant composite coating according to claim 1, characterized in that it exhibits a fine grain shape. (3) Approximately 2 to 8 mg/d of inorganic oxide film in the intermediate layer
An aluminum or aluminum alloy material having a corrosion-resistant composite film according to claim 1, which is a hydrated oxide film of m^2. (4) The inorganic oxide film of the intermediate layer is Si, Cr, Zr.
, Ti, Mo, V, and W, and the amount of the oxide film is about 0 in terms of the above elements.
．． 02 to 1.5 mg/dm^2. The aluminum or aluminum-containing material having a corrosion-resistant composite coating as claimed in claim 1.