JPS6028664B2 - Aluminum-based metal member having a coating layer of fluorine-containing copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum metal member having a specific coating layer made of a fluoroolefin/cyclohexyl vinyl ether copolymer.

The present applicant discovered that a new parent fluorine-containing copolymer that has high rigidity and is soluble in solvents can be obtained by copolymerizing fluoroolefin and cyclohexyl vinyl ether (hereinafter abbreviated as CHVE). Showa 52-92
The application is currently being filed as No. 59 (Special Publication No. 55-144083). The fluoroolefin/CHVE copolymer has a high rigidity and is soluble in solvents such as mineral spirits and ethyl acetate.When applied as a coating agent, it is easy to apply and can be used as a transparent, hard coating. It has the advantage that it can be easily formed into a film, and is also used as a material for various moldings. Furthermore, fluoroolefin C
HVE-based copolymers are easily crosslinked in the presence of oxygen by heating at 170 oo or more or by the action of specular radiation containing ultraviolet rays with a wavelength of 2,800 A or less, improving mechanical strength at high temperatures and improving solvent resistance. (Tokubuta 52-92215 (Japanese Patent Laid-Open No. 54-2689)
No.), Japanese Patent Application No. 52-112128 (Japanese Unexamined Patent Publication No. 54-462)
86) etc.). According to the research of the present inventors, fluoroolefin/CHVE-based copolymers can easily form a coating layer on the surface of various substrates, and the formed coating strength is extremely excellent as a protective layer on the surface of the substrate. It was discovered that there is. That is, in addition to the above-mentioned features, a smooth coating film with good gloss can be obtained, and the weather resistance is significantly superior to that of the conventional acrylic resin coating film. In addition, it is not only possible to form a coating film with excellent transparency, but also has excellent compatibility with various pigments, colorants, etc., so it is useful as a colored protective layer for a wide range of purposes.
The inventors of the present invention have repeatedly studied various applications that take advantage of the above-mentioned excellent features of the coating film, and have found that it is useful for, for example, color aluminum plates, bright aluminum coatings, and the like.

That is, the present invention has a coating layer of a fluorine-containing copolymer, characterized in that a coating layer made of a fluoroolefin/CHVE copolymer and having a thickness of 500 microns or less is formed on the surface of an aluminum metal member. The present invention provides a new aluminum-based metal member. The aluminum-based component of the present invention has excellent corrosion resistance because it has a protective coating layer made of a specific copolymer. In addition, since the corrosion-resistant coating layer has very good weather resistance, it can be used as an exterior building material and maintain its beauty for a long period of time by taking advantage of its photo-selective coating and free coloring. Of course,
The adhesion of the paint film is not impaired either. In the present invention, as the fluoroolefin/CHVE copolymer, a fluoroolefin is preferably used, preferably a barhaloolefin, particularly preferably tetrafluoroethylene or chlorotrifluoroethylene, and the mole of fluoroolefin/CHVE is Those having a ratio of 30/70 to 70/30 and an intrinsic viscosity of 0.1 to 2 m/d' measured at 30 qo in tetrahydrofuran are preferably employed.

Further, it is also possible to employ a compound containing a unit that fills other coweights together with the fluoroolefin and CHVE unit. Examples of such coweights include olefins such as ethylene, propylene, and isoptylene, vinyl halides such as vinyl chloride and vinylidene chloride, unsaturated carboxylic acid esters such as methyl methacrylate, vinyl acetate, and vinyl n-butyrate. carboxylic acid pinyls such as ethyl vinyl ether, n-
Examples include alkyl vinyl ethers such as butyl vinyl ether, fluorovinyl ethers, and the like. Particularly suitable are alkyl vinyl ethers in which the alkyl group has 1 to 8 carbon atoms. The content of the coweight may be appropriately selected depending on its type or purpose, but it is usually 40 mol% or less, particularly about 5 to 35 mol%. In the present invention, there is no particular reason to limit the aluminum-based metal member used as the base material, and a wide range of materials may be used, including those made of pure aluminum, those containing manganese, magnesium, etc., and those made of various aluminum-based alloys. can be adopted across the board.

In forming the specific coating layer, the aluminum-based metal member may be surface-treated as appropriate. Examples include surface cleaning treatment, surface roughening treatment, etching treatment, chromate treatment, and others. A plate-shaped body is usually suitable for the aluminum-based metal member, and the thickness of the plate-shaped body in this case is as follows:
Although not particularly limited, it is usually 0.2 to 2. From a practical point of view, it is preferable to use something that is about the same size as a proboscis. Thus, the coating layer of the specific copolymer of the present invention is formed to have a thickness of 500 microns or less.

If the thickness is too large, it is disadvantageous for widespread commercial use, and if the thickness is too small, it is undesirable from the viewpoint of coating film strength and protection. The preferred thickness of the coating layer is about 5 to 100 microns. There are no particular limitations on the method of forming the coating layer, such as applying a solution or powder of a specific copolymer to the surface of the base material, or spraying and then heating to disperse a solvent, dispersed soot, or fuse the powder. For example, methods such as applying a solution and drying the solution are preferably adopted from the viewpoint of smoothness of the formed coating film.

Of course, it is also possible to form a film of a specific copolymer in advance and apply the film to the surface of the base material by means of lamination pressure bonding, adhesive lamination, or the like. In the present invention, it is also possible to include appropriate pigments, stabilizers, lubricants, fillers, and other appropriate additives in the specific coating layer within a range that does not impair the properties of the specific coating layer.

With such additives, it is possible to improve color tone, thermal stability, abrasion resistance, non-stick properties, surface hardness, etc.
In particular, the coating layer can be colored freely by adding pigments.
It is suitable for use as an exterior building material that takes advantage of the beautiful beauty of the material of the present invention. The specific coating layer of the present invention is preferably crosslinked.

For example, Tsubaki Gan Sho 52-92215 specification, Tokuiso Sho 52
170-350°C, preferably 190-350°C in the presence of oxygen, as described in Japanese Patent No. 1112128, etc.
By heating at a temperature of about 100 qo for 1 to 200 cm, preferably for about 5 to 120 minutes, or using a light source that generates short wavelength ultraviolet rays such as a carbon arc lamp, a hydrogen discharge tube, or a low-pressure mercury lamp. Wavelength 280 in the presence of oxygen
The specific coating layer can be crosslinked by applying specular radiation containing ultraviolet rays of 0A or less. The aluminum-based member having the specific coating layer of the present invention can be processed into a corrugated plate, etc., and can be subjected to various other secondary processing and used in various applications and fields.

Examples include exterior aluminum materials in the housing-related field such as colored aluminum plates and aluminum sashes, automobile parts such as aluminum wheels and aluminum bumpers, and reflectors. Next, examples of the present invention will be described in more detail, but it goes without saying that the present invention is not limited by such explanation.

The method for testing the performance of an aluminum-based metal member having a specific coating layer according to the present invention will be described below.

1 Adhesion Durability 1-1 Goban Boiling Test Draw 11 vertical and 11 horizontal lines reaching the substrate on the test piece at 1 willow intervals to create 100 gobans.

After boiling this in water for 2 hours and removing the water,
A cellophane adhesive tape was attached on top of the tape, and it was peeled off in one motion directly upward, and its adhesion was evaluated based on the number of stitches remaining/100.

For example, 100/100 indicates that no peeling is observed and good adhesion is achieved. (According to the method according to JIS-K5400) 1-2 Drawn Eriksen test specimen with spiral diameter IQ, 1 rotation phase difference 2.
The hardness of helix 2 on the 5th side is drawn using a drawing tester at a constant speed of 1 rotation for 1 second, and then using an Eriksen tester, the test piece is pushed out with the drawn part outward so that it has a height of 5 willows, and the coating film is The degree of peeling was visually determined.

2 Weather Resistance Using a Sunshine Weatherometer device manufactured by Suga Test Instruments ■, after a certain period of irradiation test, measure the 60 degree specular light selectivity specified in JIS-K5400, and calculate the gloss retention rate with respect to the gloss level before the test. Calculated.

This gloss retention rate and appearance observation were used as evaluation criteria.
3 Surface glossiness Measured using the 60 degree specular gloss measurement method specified in JIS-K Oni 00.

4 Salt water mist test A painted board (with a cross cut that extends over the base material) was placed vertically into a salt water spray tester maintained at 35 ± 1°C.
Leave it at 5-30o and add 5% saline solution to 1-2'/80.
After 100 field hours, rusting and other abnormalities on the painted surface were visually determined.

(According to JIS-Z2371) The intrinsic viscosity of the copolymer was measured in tetrahydrofuran at 30:00. Example 1 A CTFE/CHVE copolymer containing chlorotrifluoroethylene (hereinafter abbreviated as CTFE) and CHVE in a molar ratio of 51/49 and an intrinsic viscosity of 0.60 was used to produce a copolymer with the composition shown below. A white paint composition was prepared.

Copolymer 21 parts by weight Ti0
2 9 Solvent (methyl isobutyl ketone/xylene = 75/25 (parts by weight)) 70 Apply using a film applicator to a 0.8-thick aluminum plate that has been previously chromate-treated, and evaporate the solvent at 14,000 yen. After that, it was baked at 210℃ for 20 minutes to a thickness of 20℃.
A white coated aluminum plate with excellent gloss was obtained.

As shown in Table 1, the coating layer showed sufficient adhesion durability as a result of the drawing Eriksen and rice boiling tests.
Moreover, as a result of the salt spray test, no abnormality was observed after 100 beats.

Further, in an accelerated weathering test using a Sunshine Weatherometer, there was no change in the coating surface even after 400 calm hours, and the gloss retention rate was 95%. Example 2 Same as Example 1 except that the copolymer was a CTFE/CHVE/ethyl vinyl ether (containing molar ratio: 51/15/34) terpolymer (intrinsic viscosity 0.6). According to the construction conditions, a white coated aluminum plate with a thickness of 20 mm was obtained.

The test results are shown in Table 1.

Example 3 The copolymer shown in Example 1 was mixed with methyl isobutyl ketone 7.
It was dissolved in a mixed solvent consisting of 5 parts by weight of xylene and 25 parts by weight to prepare a 25% by weight solution.

A transparent coated aluminum plate having a thickness of 20 cm was prepared using this solution in the same manner as in Example 1. Table 2 shows the results of various tests on this coated plate.

Example 4 A transparent coated aluminum plate having a thickness of 20 µm was prepared under the same construction conditions as in Example 3 except that the copolymer was the same as in Example 2.

Table 2 shows the results of various tests on this coated plate. Table I Table 2

Claims (1)

[Scope of Claims] 1. A coating of a fluorine-containing copolymer, characterized in that a coating layer of a fluoroolefin/cyclohexyl vinyl ether copolymer with a thickness of 500 microns or less is formed on the surface of an aluminum metal member. An aluminum-based metal member with layers. 2. The aluminum-based metal member according to claim 1, wherein the fluoroolefin is tetrafluoroethylene. 3. The aluminum-based metal member according to claim 1, wherein the fluoroolefin is chlorotrifluoroethylene. 4 The molar ratio of fluoroolefin/cyclohexyl vinyl ether is 30/70 to 70/30, and the intrinsic viscosity measured at 30°C in tetrahydrofuran is 0.1.
The aluminum-based metal member according to claim 1, 2, or 3, which uses a fluorine-containing copolymer having a fluorine-containing copolymer having a fluorine content of 2 g/dl. 5 The molar ratio of fluoroolefin/cyclohexyl vinyl ether is 30/70 to 70/30, and the third component is 5 to 40 mol% of alkyl vinyl ether whose alkyl group has 1 to 8 carbon atoms based on the total monomers. Contains
The aluminum system according to claim 1, 2, or 3, which uses a fluorine-containing copolymer having an intrinsic viscosity of 0.1 to 2 g/dl as measured in tetrahydrofuran at 30°C. metal parts. 6. The aluminum-based metal member according to claim 1, wherein the coating layer is crosslinked by being heated to 170° C. or higher in the presence of oxygen. 7. The aluminum-based metal member according to claim 1, wherein the coating layer is crosslinked by the action of radiation including low wavelength ultraviolet rays having a wavelength of 280 nm or less in the presence of oxygen.