JP2002067218A - Resin coated aluminum alloy member and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin coated aluminum alloy member excellent in the adhesion to a resin film and a method for manufacturing the same. SOLUTION: The resin coated aluminum alloy member is constituted by forming a resin film on an aluminum alloy for non-heat treatment molded by hot extrusion, and the surface of the aluminium alloy is oxidized and no hydrate is formed on the surface of the aluminum alloy. This resin coated aluminum alloy member can be manufactured by (A) a molding process for subjecting the aluminum alloy for non-heat treatment to hot extrusion molding at 350-530 deg.C, (B) a cooling process for cooling the surface temperature of the molded aluminum alloy to 240-340 deg.C in 900 sec in the atmosphere and (C) a resin coating process for applying a resin to the surface of the aluminum alloy to cool the coated resin to form the resin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated aluminum alloy member in which a resin film is formed on the surface of a non-heat-treated aluminum alloy formed by hot extrusion and a method for producing the same.

[0002]

2. Description of the Related Art Resin-coated aluminum alloy members in which an aluminum alloy is coated with a resin film are widely used for frames of automotive window glasses, aluminum sashes and the like. As a method of manufacturing such a resin-coated aluminum alloy member, Japanese Patent Publication No. 58-22267 and the like first extrude an aluminum alloy for non-heat treatment by hot extrusion and use the heat of this extrusion to powder the resin powder. A method of painting and forming a resin film is proposed. Normally, when left to cool to room temperature after extrusion, hydrates are formed on the surface of the aluminum alloy and the resin does not adhere at all. However, in this method, almost all hydrates are formed due to continuous powder coating after extrusion. Not done. However, in such a conventional method, the adhesion of the resin film is low, and it is difficult to control the adhesion.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin-coated aluminum alloy member having excellent adhesion of a resin film,
And a method for producing the same.

[0004]

Means for Solving the Problems In view of the above problems, as a result of intensive studies, the present inventors have found that an aluminum alloy is hot extruded, cooled under specific conditions, and then formed with a resin film on its surface. As a result, the present inventors have found that a resin-coated aluminum alloy member having excellent adhesion of a resin film can be obtained, and have reached the present invention.

That is, the resin-coated aluminum alloy member of the present invention is obtained by forming a resin coating on the surface of a non-heat-treated aluminum alloy which is hot-extruded, and the surface of the aluminum alloy is oxidized and It is characterized by not forming a sum.

[0006] In the resin-coated aluminum alloy member of the present invention, the resin coating is preferably made of a thermoplastic resin having a melting point of 200 ° C or higher. The thermoplastic resin is preferably a polyester resin or a polyamide resin or a modified resin thereof, or a polymer alloy containing the same, and more preferably polybutylene terephthalate. Such a thermoplastic resin is preferably partially thermally decomposed in the resin coating.

The method for producing a resin-coated aluminum alloy member according to the present invention is a method for producing the resin-coated aluminum alloy member according to the present invention, wherein (A) an aluminum alloy for non-heat treatment is heated at 350 to 530 ° C. (B) a cooling step of cooling the formed aluminum alloy to a surface temperature of 240 to 340 ° C. within 900 seconds in the atmosphere, and (C)
The method is characterized by including a resin coating step of applying a resin on the surface of the aluminum alloy and cooling it to form a resin coating.

In the method for producing a resin-coated aluminum alloy member of the present invention, the cooling step is preferably performed using dry air as a cooling gas. In the resin coating step, it is preferable to apply the resin in a molten state by heating.
At this time, the temperature of the resin in the molten state is preferably 230 to 330 ° C.

The resin film is preferably made of a thermoplastic resin having a melting point of 200 ° C. or higher. The thermoplastic resin is preferably a polyester resin or a polyamide resin or a modified resin thereof, or a polymer alloy containing the same, and more preferably polybutylene terephthalate. When such a thermoplastic resin is used, after the thermoplastic resin is applied on the surface of the aluminum alloy, the resin is kept in a molten state for at least 1.5 seconds and then cooled to form a resin film. , It is preferable to partially thermally decompose the thermoplastic resin in the resin film.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION [1] Resin-coated aluminum alloy member The resin-coated aluminum alloy member of the present invention is obtained by forming a resin film on the surface of a non-heat-treated aluminum alloy formed by hot extrusion. Hereinafter, each component of the resin-coated aluminum alloy member of the present invention will be described in detail.

(A) Aluminum Alloy In the resin-coated aluminum alloy member of the present invention, the surface of the aluminum alloy is oxidized and does not form a hydrate. Only a part of the aluminum alloy surface may be oxidized or the whole may be oxidized. When only a part of the surface is oxidized, the active non-oxidized part is preserved, and it is considered that this non-oxidized part interacts with the resin to improve the adhesion. When the entire surface is oxidized, the surface structure must be γ-alumina having lattice defects or a structure similar thereto. In this surface structure, some of the aluminum atoms are exposed due to lattice defects, and it is considered that these aluminum atoms function as active centers to improve adhesion. Such a resin-coated aluminum alloy member containing an aluminum alloy can be obtained by the manufacturing method of the present invention described later.

The aluminum alloy used in the present invention is not particularly limited, and JIS standards A6063, 2024, 7075 and the like can be used.

(B) Resin Coating In the resin-coated aluminum alloy member of the present invention, the resin forming the resin coating is an olefin resin, a styrene resin,
Acrylic resin, polyester resin, polyamide resin,
The modified resin may be used. Further, a polymer alloy containing any of them can also be used. Further, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ionomer, and the like, and a mixture thereof may be used.

The resin film is preferably made of a thermoplastic resin having a melting point of 200 ° C. or higher. The thermoplastic resin is preferably a polyester resin or a polyamide resin or a modified resin thereof, or a polymer alloy containing the same, and more preferably polybutylene terephthalate. Such a thermoplastic resin is preferably partially thermally decomposed in the resin coating. This thermal decomposition improves the adhesion between the aluminum alloy and the resin coating, but the carboxyl groups and the like generated by the decomposition of the resin are active sites on the surface of the aluminum alloy (the active non-oxidized portion or the exposed aluminum activity). This is considered to be due to coordination at the (center), an intermolecular force or an electric attraction acts between them, and an ionic bond or a covalent bond is formed.

The thickness of the resin film is not particularly limited, but may be, for example, about 10 to 60 μm when used in an automobile. The method for forming the resin film will be described later.

[2] Method of Manufacturing Resin-Coated Aluminum Alloy Member According to the method of manufacturing a resin-coated aluminum alloy member of the present invention, the above-described resin-coated aluminum alloy member of the present invention can be manufactured. The production method of the present invention includes (A) a molding step, (B) a cooling step, and (C) a resin coating step. The production method of the present invention is preferably applied to the production of a resin-coated aluminum alloy member in which an aluminum alloy extruded material having a length and width of 3 to 100 mm and a thickness of about 0.5 to 5 mm is coated with a resin coating having a thickness of about 2 to 150 μm. it can.

FIG. 1 is a sectional view showing an example of a resin-coated aluminum alloy member manufacturing apparatus which can be preferably used in the method for manufacturing a resin-coated aluminum alloy member of the present invention. The resin-coated aluminum alloy member manufacturing apparatus 1 shown in FIG. 1 can coat the surface of the aluminum alloy 2 with the resin 3 to manufacture the resin-coated aluminum alloy member of the present invention. Hereinafter, each step of the production method of the present invention will be described in detail with reference to FIG. 1, but the present invention is not limited thereto, and various changes can be made without changing the gist of the present invention.

(A) Forming Step First, an aluminum alloy for non-heat treatment is formed by hot extrusion. The aluminum alloy used in the present invention is as described above. For example, as shown in FIG. 1, the aluminum alloy 2 is placed between containers 41, the extrusion speed is controlled by a hydraulic plunger 43 while the temperature is adjusted by a temperature control container heater 42, and the aluminum alloy 2 can be extruded from a die 44.

The temperature at the time of extrusion may be from 350 to 530 ° C., preferably from 450 to 500 ° C. Extrusion temperature 350
If the temperature is lower than ℃, extrusion is difficult. If the temperature is higher than 530 ° C., the surface of the extruded material is not preferably melted due to partial heat generation due to processing heat.

(B) Cooling Step Next, the aluminum alloy is cooled in the air to a surface temperature of 240 to 340 ° C. within 900 seconds. More preferably, the aluminum alloy is cooled to a surface temperature of 260-340 ° C within 300 seconds. Usually, when the aluminum alloy is left in the air and cooled to around room temperature after extrusion, hydrates are formed on the surface and the resin does not adhere at all, but in the method of the present invention, the cooling conditions must be strictly set. Thereby, the formation of a hydrate can be suppressed. Further, by cooling under the above conditions, an aluminum alloy having the above-mentioned preferable active surface can be obtained. A method of cooling the surface of an aluminum alloy in an inert gas in order to make the surface of the aluminum alloy non-oxidizing is already known (Japanese Patent Application Laid-Open No. H11-147073). Thus, an aluminum alloy having an active surface can be obtained even when cooled at a lower temperature.

The cooling may be carried out simply by standing or by using a cooling gas or a refrigerant. In order to prevent the formation of hydrates and control the adhesion, it is preferable to use dry air as a cooling gas. For example, as shown in FIG. 1, the formed aluminum alloy 2 can be introduced into the chamber 52 through the space between the base plates 51 and cooled by flowing dry air in the direction of arrow A. Preferably,
Radiation thermometer 53 to measure the surface temperature of the cooled aluminum alloy
And cools while controlling the temperature and flow rate of the dry air according to the surface temperature. The temperature of the dry air may be usually from room temperature to 50 ° C.

(C) Resin coating step Subsequently, a resin is applied on the surface of the cooled aluminum alloy, and cooled to form a resin film. For example, as shown in FIG. 1, a cooled aluminum alloy 2 is immersed in a molten resin 3 heated by a thermocouple 61, passed through a temperature control heater slit 62, and cooled with water by a cooler 63 to form a resin-coated aluminum. An alloy member can be obtained.

The application of the resin may be performed in the air, and is preferably performed in dry air. If the humidity of the air is high, hydrates are easily formed on the surface of the aluminum alloy, and in addition, hydrolysis of the resin may occur, which is not preferable.

As a method of applying the resin, a general dipping method, a curtain coating method by T-die extrusion of the resin, and the like can be used. The resin may be applied in a molten state or a powder, but is preferably applied in a molten state by heating. When a powdery resin is used, it is necessary to raise the temperature of the aluminum alloy (about 400 ° C.), and the resin is likely to be deteriorated, and sufficient adhesiveness may not be obtained. Further, by applying a resin in a molten state, cost can be reduced as compared with the case of performing powder coating.

When the resin is applied in a molten state by heating, the temperature of the resin is preferably 230 to 330 ° C.
The temperature is more preferably set to 0 to 300 ° C. When the resin temperature is lower than 230 ° C., the resin viscosity is high and the application is difficult.
If the temperature exceeds 0 ° C., the resin is significantly deteriorated.

The resin forming the resin film is an olefin resin,
Styrene resin, acrylic resin, polyester resin,
It may be a polyamide resin or a modified resin thereof. Also,
Polymer alloys containing any of them can also be used.
Further, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ionomer, and the like may be used.

The resin film is preferably made of a thermoplastic resin having a melting point of 200 ° C. or higher. The thermoplastic resin is preferably a polyester resin or a polyamide resin or a modified resin thereof, or a polymer alloy containing the same, and more preferably polybutylene terephthalate. When such a thermoplastic resin is used, after the thermoplastic resin is applied on the surface of the aluminum alloy, the resin is kept in a molten state for at least 1.5 seconds and then cooled to form a resin film. , It is preferable to partially thermally decompose the thermoplastic resin in the resin film. This thermal decomposition improves the adhesion between the aluminum alloy and the resin film as described above. The molten state holding time is more preferably 1.8 seconds or more.

For example, when polybutylene terephthalate is used as the resin, by holding the molten state for 1.5 seconds or more after coating, the polybutylene terephthalate partially thermally decomposes as in the following formula (I) to form a carboxyl group. I do. The carboxyl group coordinates or forms a bond with an active site on the surface of the aluminum alloy, thereby improving the adhesion between the resin and the aluminum alloy. Although the molecular weight of the resin is reduced by the thermal decomposition, no adverse effect is usually observed due to the reduced molecular weight.

[0029]

Embedded image

The cooling after the application of the resin can be performed by air cooling or water cooling, or simply by leaving it in the air. The cooling rate is not particularly limited, but rapid cooling by water cooling is preferable.
Rapid cooling improves the crystallinity and improves the adhesion.

According to a particularly preferred embodiment of the present invention,
On the surface of the aluminum alloy cooled to a surface temperature of 260 to 340 ° C, polybutylene terephthalate heated to 240 to 300 ° C and applied in a molten state is applied. The resin is thermally decomposed as shown in the above formula (I) and cooled with water to form a resin film. As described above, in the production method of the present invention, it is very important to set the surface temperature, the resin temperature, and the molten state holding time after the application of the aluminum alloy.

[0032]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited thereto.

1. Production of Resin-Coated Aluminum Alloy Member The resin-coated aluminum alloy member of the present invention was produced using the resin-coated aluminum alloy member production apparatus 1 shown in FIG. First, 450 parts of aluminum alloy (JIS standard A6063)
Hot extrusion molding was performed at ℃ to obtain a molded product having a width of 25 mm and a thickness of 3 mm. Next, the aluminum alloy molded article was cooled in the air using dry air at 25 ° C. as a cooling gas. Subsequently, the cooled aluminum alloy molded product was immersed in molten polybutylene terephthalate (PBT, “C7000” manufactured by Teijin Limited), and PBT was applied on the surface thereof. After the application, the resin was kept in a molten state for a predetermined time and then cooled with water to form a resin film. The surface temperature of the aluminum alloy during resin application is 240 ° C, 260 ° C, 280 ° C, 300 ° C, 320 ° C or 340 ° C,
240 ℃, 260 ℃, 280 ℃, 300 ℃ or 3
The resin-coated aluminum alloy members shown in Table 1 were produced at 20 ° C., and the molten state holding time of the resin was set at 0.7 seconds, 1.0 seconds or 1.8 seconds. The cooling time was 5 to 20 seconds.

2. Cross cut tape peeling test Each of the resin-coated aluminum alloy members manufactured as described above was boiled in pure water for 3 hours, and then a cross cut tape peel test was performed to examine the adhesion between the resin film and the aluminum alloy. . Table 1 shows the results.

[0035]

[Table 1]

From Table 1, it was confirmed that when the holding time of the molten state of PBT is increased, a resin-coated aluminum alloy member having excellent adhesion can be obtained even when the surface temperature of the aluminum alloy is lowered. That is, by increasing the contact time between the molten PBT and the aluminum alloy to promote the reaction at the interface, a resin film having excellent adhesion can be formed.
When the molten state holding time is 1.8 seconds, the surface temperature of the aluminum alloy at the time of resin application is 260 to 340 ° C, and the PBT to be applied
It is understood that the temperature is preferably 240 to 300 ° C.

3. XPS Measurement PBT in the resin-coated aluminum alloy member was dissolved and removed with heptafluoroisopropyl alcohol (HFIPA), and XPS (X-ray photoelectron spectroscopy) analysis was performed. FIG. 2 shows the XPS spectrum of the PBT of the resin-coated aluminum alloy member that exhibited excellent adhesion in the above-mentioned cross cut tape peeling test.
FIG. 3 shows the XPS spectrum of T.

As shown in FIGS. 2 and 3, the PBT of the resin-coated aluminum alloy member having excellent adhesion exhibited a peak derived from the C ＝ O bond of the carboxyl group, but the resin-coated aluminum alloy member having poor adhesion was observed. Did not show PBT. This indicates that in the resin-coated aluminum alloy member exhibiting excellent adhesion, the thermal decomposition reaction of the above formula (I) occurs to form a carboxyl group, and as a result, the adhesion is improved.

[0039]

As described in detail above, the resin-coated aluminum alloy member of the present invention has excellent adhesion between the resin coating and the aluminum alloy. Such a member can be manufactured by the method for manufacturing a resin-coated aluminum alloy member of the present invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a resin-coated aluminum alloy member manufacturing apparatus that can be used in the method for manufacturing a resin-coated aluminum alloy member of the present invention.

Fig. 2 X of PBT resin in a resin-coated aluminum alloy member with excellent adhesion between the resin coating and the aluminum alloy
It is a PS spectrum.

Fig. 3 XPS of PBT resin in a resin-coated aluminum alloy member with poor adhesion between the resin film and the aluminum alloy
It is a spectrum.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Apparatus for manufacturing a resin-coated aluminum alloy member 2 ... Aluminum alloy 3 ... Resin 41 ... Container 42 ... Temperature controlled container heater 43 ... Hydraulic plunger 44 ... Dies 51 ... Base plate 52 ・ ・ ・ Chamber 53 ・ ・ ・ Radiation thermometer 61 ・ ・ ・ Thermocouple 62 ・ ・ ・ Temperature control heater slit 63 ・ ・ ・ Cooler

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masataka Kumada 4-1-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 4D075 BB18X BB22X BB57X CA13 DA23 DB07 DC13 EA17 EB35 EB39 EB53 4F100 AB10A AB31A AK01B AK41B AK42B AK46B AL05B AL06B BA02 BA07 DA11 EH17A EH171 EH462 EJ12A EJ421 EJ422 EJ501 EJ502 GB07 JA04B JB16B JL11 YY00A YY00B

Claims (11)

[Claims] 1. A resin-coated aluminum alloy member in which a resin film is formed on a surface of a non-heat-treated aluminum alloy formed by hot extrusion, wherein the surface of the aluminum alloy is oxidized and a hydrate is formed. A resin-coated aluminum alloy member characterized in that it is not provided. 2. The resin-coated aluminum alloy member according to claim 1, wherein the resin film is made of a thermoplastic resin having a melting point of 200 ° C. or more, and the thermoplastic resin is a polyester resin or a polyamide resin or a modified resin thereof.
Alternatively, a resin-coated aluminum alloy member, which is a polymer alloy containing the same. 3. The resin-coated aluminum alloy member according to claim 2, wherein said thermoplastic resin is polybutylene terephthalate. 4. The resin-coated aluminum alloy member according to claim 2, wherein the thermoplastic resin in the resin film is partially thermally decomposed. 5. An aluminum alloy for non-heat treatment of 350A.
Forming step of hot extrusion at 530 ° C., (B) in air, the formed aluminum alloy has a surface temperature of 240 seconds within 900 seconds.
And (C) a resin coating step of applying a resin on the surface of the aluminum alloy and cooling the resin to form a resin coating. . 6. The method for manufacturing a resin-coated aluminum alloy member according to claim 5, wherein the cooling step is performed using dry air as a cooling gas. 7. The method of manufacturing a resin-coated aluminum alloy member according to claim 5, wherein in the resin coating step, the resin is applied in a molten state by heating. Method. 8. The method for producing a resin-coated aluminum alloy member according to claim 7, wherein the temperature of the resin in a molten state is 230 to 330 ° C. 9. The method for producing a resin-coated aluminum alloy member according to claim 5, wherein the resin coating is made of a thermoplastic resin having a melting point of 200 ° C. or more,
A method for producing a resin-coated aluminum alloy member, wherein the thermoplastic resin is a polyester resin, a polyamide resin, a modified resin thereof, or a polymer alloy containing the same. 10. The method of manufacturing a resin-coated aluminum alloy member according to claim 9, wherein the thermoplastic resin is polybutylene terephthalate. 11. The method for producing a resin-coated aluminum alloy member according to claim 9, wherein the thermoplastic resin is melted after applying the thermoplastic resin on a surface of the aluminum alloy. A method for producing a resin-coated aluminum alloy member, wherein the thermoplastic resin in the resin film is partially thermally decomposed by holding the resin film for 1.5 seconds or more and then cooling to form the resin film.