JP4500613B2 - Surface brightening method - Google Patents

Description

The present invention relates to a surface brightening method for a molded product obtained by surface brightening the surface of a metal base material or a resin base material.

  There are many molded products that give a sense of quality and taste by changing the texture and color of the base material by applying surface brightening treatment such as plating to the surface of the metal base material or resin base material. is doing. For example, even in the case of aluminum alloy wheels for automobiles, in recent years, in order to improve the designability, surface glitter treatment is applied to the wheel design surface to express a heavy feeling and a magnificent metallic tone. Various surface brightening methods have been proposed.

  As such a surface brightened molded article and processing method, for example, in Patent Document 1, a black base layer is formed on the surface of a metal base material, and an aluminum alloy is formed on the base layer. There has been proposed a configuration in which a metal reflective film formed by plating is formed and a top coat layer is formed thereon. In this configuration, the metallic reflective film slightly transmits the black color of the base layer, thereby expressing a black metallic appearance. Since such an appearance can give rise to a high-class feeling, for example, in an aluminum alloy wheel, its design can be improved.

Further, for example, in Patent Document 2, the thickness of the metal reflective film is changed and the transmittance is changed between the flat part of the aluminum part (molded product) and the vertical part and the back part of the aluminum part. A proposed configuration has been proposed. In such a configuration, when the aluminum part is viewed from an oblique direction as compared to when viewed from the front, the color of the flat surface portion, the vertical surface portion, and the back portion appears to be different. The aluminum parts can be made to exhibit high design properties.
JP-A-9-290213 JP 2003-25495 A

  By the way, in the structure (patent document 1) formed by forming a metal reflection film that slightly transmits the black color of the base layer described above, the molded product has an overall black metallic appearance. Therefore, unlike the configuration (Patent Document 2) in which the film thicknesses of the flat surface portion, the vertical surface portion, and the back portion are changed, the surface glittering process in which the color tone partially changes is not performed. That is, in the former configuration (Patent Document 1), since the molded product is expressed with a single color tone as a whole, the change is scarce, it is relatively easy to get tired, and there is a limit in design.

  On the other hand, in the latter configuration (Patent Document 2), when performing sputtering for forming a metal reflective film, the standing surface portion and the back portion are hidden with a mask, or the sputtering target is opposed to the flat surface portion. It arrange | positions and it is made for this standing surface part and a back part to become thin film thickness compared with a plane part. However, in the case where sputtering is usually performed on a molded article having an uneven shape such as an aluminum alloy wheel, the film thickness of the standing surface portion and the back portion is likely to be thinner than that of the flat surface portion without being hidden by a mask or the like. In addition, such an upright part and the back part seem to change the impression even if the surrounding light is adjusted, so in an aluminum alloy wheel formed by forming a metal reflective film by sputtering normally. However, when looking from an oblique direction, the color tone appears to change. In addition, the plane portion is expressed with a single color tone as a whole, as in the former configuration (Patent Document 1). Therefore, even if the film thickness of the raised surface portion and the back portion is reduced and the transmittance is changed, the impression of the viewer cannot be greatly changed, and the effect of improving the design is not sufficiently exhibited.

The present invention proposes a surface brightening treatment method for a molded product that has been subjected to surface brightening treatment and can exhibit excellent designability in response to a further demand for improved designability.

The first surface-brightened molded product to which the method of the present invention is applied includes a colored base layer obtained by applying a colored paint of a predetermined color on the surface of a metal base material or a resin base material, and the colored base. A metal reflective film on which a pure metal or a metal alloy is formed so that the film thickness gradually decreases from the center of the base material toward the outer edge of the base material. To do.
Alternatively, as the second surface brightened molded article, on the surface of the metal base material or the resin base material, a colored base layer formed by applying a colored paint of a predetermined color, on the colored base layer, And a metal reflective film on which a pure metal or metal alloy is formed so that the film thickness gradually decreases from the outer edge of the base material toward the center of the base material.

Here, in the case of a metal reflective film in which a pure metal or a metal alloy is formed, as the film thickness decreases, the transmittance that can pass through the base of the metal reflective film increases. Therefore, the color tone of the metal appears at a portion formed with a sufficient film thickness, and a so-called gradation tone appears in which the color tone changes so that the predetermined color of the base gradually appears stronger as the film thickness becomes thinner. In the first invention, since the thickness of the metal reflective film formed on the colored base layer is gradually reduced from the base material central part toward the base material outer edge part, The portion has a strong metallic tone of the metal target, and a gradation tone is expressed in which the base color is emphasized by gradually increasing the transmittance toward the outer edge of the base material. On the other hand, in the molded product subjected to the second surface brightening treatment , conversely, since the thickness gradually decreases from the outer edge portion of the base material toward the center portion of the base material, the metal tone of the metal target is strong. A gradation tone is expressed in which the base color is gradually emphasized from the outer edge of the material toward the center of the base material.

According to such a molded product subjected to the first and second surface brightening treatments , for example, in the case of being adapted to an aluminum alloy wheel for automobiles, the substantially flat design surface extends from the wheel center to the outer edge of the wheel. Towards the part (from the outer edge of the wheel toward the center of the wheel), the color tone gradually changes and a multicolor appearance is expressed. Note that this wheel appears multicolored when viewed from any direction, regardless of the amount of ambient light. Further, the gradation of gradation expressed between the wheel center portion and the wheel outer edge portion of the vehicle wheel is visible even when the vehicle wheel is rotating while the vehicle is running. For this reason, the appearance according to the present invention is clearly expressed not only when the automobile is stopped but also during traveling. Thus, the aluminum alloy wheel for automobiles has an unprecedented appearance and can exhibit high designability, and its value is remarkably improved.

In addition, in such a 1st molded product, you may make it have the site | part in which the metal reflective film is not formed in the outer periphery of a base material, and the color of a coloring base layer may appear directly. Similarly, in the configuration of the second invention, it may have a portion where the metal reflective film is not formed at the center of the base material. As a result, the above-described gradation change range is increased. For example, when the color of the colored base layer is completely different from the metal color, the difference in color between the center of the base material and the outer edge of the base material becomes large, and the polychromaticity of the appearance is further emphasized. Could be. In addition, such a metal reflective film is preferably formed by sputtering pure aluminum or an aluminum alloy having high reflectivity. This is because the sputtering method, which is one of the physical vapor deposition methods (PVD), can properly form a structure in which the thickness of the metal reflective film gradually decreases, and a desired gradation-like appearance can be obtained relatively easily. Because it can.

Here, in the first molded article described above, the metal reflective film formed on the colored base layer has a thickness that does not transmit through the colored base layer at the center of the base material. A configuration is proposed. On the other hand, in the second molded article described above , the metal reflective film formed on the colored base layer in the configuration of the second invention transmits the colored base layer at the outer edge of the base material. A configuration with a non-performing film thickness is proposed. In such a configuration, the color of the colored base layer is not expressed at all in the central part of the base material of the first molded product and the outer edge of the base material of the second molded product , and only the metallic tone of the metal target is expressed. The Rukoto. For this reason, the gradation which permeate | transmits a colored base layer can be made more conspicuous, and the effect of this invention mentioned above increases further. Furthermore, even when it is applied to an aluminum alloy wheel for automobiles, as described above, the effect of the present invention that can exhibit high designability is further improved.

On the other hand, the present invention provides a colored base by applying a colored paint of a predetermined color on the surface of a metal base material or a resin base material as a surface brightening method for performing a surface treatment on the above-described molded product subjected to the surface brightening treatment. After performing the base layer forming step for forming the layer, the metal base material or the resin base material on which the colored base layer is formed is arranged so that the surface of the base material faces a metal target made of pure metal or metal alloy. And rotating at a predetermined speed with an axis substantially perpendicular to the surface of the base material as a center of rotation, and forming a periodic film forming portion on the base material surface that is periodically covered and sputtered by a metal target along with the rotation, The present invention relates to a method of performing a reflection film forming step in which a metal reflection film is formed .

  In this method, the portion of the base material surface covered with the metal target sequentially changes in the circumferential direction as the base material rotates, and the covered portion also makes one rotation according to the distance from the rotation center. The time covered by the hit is also different. For this reason, the periodic film formation site formed by sputtering can be formed such that the film thickness gradually increases (or decreases) according to the distance from the rotation center. In the periodic film formation site formed in this way, the metallic tone of the metal target appears strongly in the relatively thick part, and the film thickness becomes thinner in the radial direction or radial direction with respect to the rotation center. The transmittance of the colored base layer is increased, and a so-called gradation-like appearance in which the color of the colored base layer gradually appears is expressed. That is, according to this method, the metal reflection film according to the present invention described above, in which the film thickness gradually decreases from the center to the outer edge (or from the outer edge to the center) of the molded product, can be appropriately and easily performed. A film can be formed.

  Here, for example, when the surface brightening treatment method of the present invention is applied to an aluminum alloy wheel for automobiles, a rectangular parallelepiped metal target having a long side substantially equal to the wheel diameter is prepared. The metal target is disposed so as to face the wheel design surface above the wheel design surface at a position where at least the wheel center portion is not covered and the wheel outer peripheral edge portion is partially covered. Then, while rotating about the wheel center axis as a center of rotation and performing sputtering, it is possible to form on the design surface a periodic film forming portion where the film thickness gradually decreases from the outer peripheral edge of the wheel toward the center of the wheel. By forming the metal reflective film in this manner, an aluminum alloy wheel having the configuration according to the second aspect of the present invention can be appropriately obtained. That is, according to the surface brightening treatment method of the present invention, it is possible to easily and appropriately obtain a molded product (for example, an automobile wheel) that expresses a gradation-like appearance that has not been heretofore described. And this molded article can have a high designability as mentioned above.

  In the reflection film forming step described above, the sputtering can be controlled and executed so that the periodic base film forming part has a film thickness that allows the colored base layer to pass through the thickest part. In this method, the transmittance of the colored base layer can be appropriately set by determining the film thickness of the thickest part of the periodic film formation site. For example, the color base layer may have a transmittance that allows slight transmission so that the metallic tone of the thickest portion is emphasized and the gradation tone is relatively enhanced. Alternatively, by increasing the transmittance, the gradation can be relatively weakened as a whole of the periodic film forming portion, and the appearance of the color base layer can be expressed.

  On the other hand, there is also a method in which the reflective film forming process controls the sputtering so that the colored base layer does not transmit the thickest part of the base material surface within the periodic film forming part. Proposed. Here, in the above-described sputtering, the portion that is covered with the metal target for the longest time along with the rotation of the base material is formed with the thickest thickness among the periodic film forming portions. Therefore, by performing sputtering while appropriately setting the time covered by the metal target, the shape of the metal target, and the like, the film is formed to a thickness that does not allow the lower colored base layer to pass through. The periodic film formation site formed by such a method does not reveal the color of the colored base layer at the thickest part, only the metallic tone of the metal target is clearly expressed, and as the film thickness gradually decreases from this part, As described above, a gradation-like appearance in which the color of the colored base layer becomes strong can be expressed. As a result, the color difference between the thickest part and the thinnest part of the periodic film formation portion becomes large, and gradation can be emphasized. If this method is applied to the surface treatment of an aluminum alloy wheel in the same manner as described above, an automotive wheel having higher designability can be obtained as described above.

  Further, in such a surface brightening treatment method, the reflective film forming step forms a periodic film forming portion that is periodically covered and sputtered by the metal target on the surface of the base material, and is constantly applied to the metal target. There is proposed a method in which a metal deposition film is formed by always forming a film deposition site that is covered and sputtered. In such a method, as described above, the portion periodically covered by the metal target as the base material rotates and the portion always covered by the metal target regardless of the rotation are on the base material surface. The metal target and the base material are arranged so as to face each other. Then, by rotating the base material and performing sputtering, a periodic film forming portion where the film thickness gradually increases or decreases and a constant film forming portion where the film thickness is constant are formed. Here, since the time during which the constant film formation site is covered with the metal target is longer than that in the periodic film formation site, the film thickness is increased. Therefore, it consists of a constant film formation portion where the metallic tone of the metal target is emphasized and a gradation-like periodic deposition portion where the color of the colored base layer gradually increases from the metallic tone of the metal target as described above. A molded product having an appearance can be obtained appropriately and easily. In addition, it is possible to form the constant film forming portion relatively easily by arranging the metal target so as to cover the periphery of the rotation center of the base material, which is preferable. For example, it is possible to always form a film formation site around the rotation center by sputtering a rectangular metal target facing the base material along the radial direction from the center of rotation of the base material. At the same time, it is possible to form a periodic film forming portion where the film thickness gradually decreases from the center of rotation toward the outer radial direction and the color of the colored base layer becomes stronger. Here, if the center of rotation is provided in the center part of the base material, a metal reflective film whose thickness gradually decreases from the base material center part toward the base material outer edge part is applied. A molded article having a configuration can be appropriately obtained.

  Here, for example, when the above surface brightening treatment method is applied to an aluminum alloy wheel for automobiles, a rectangular parallelepiped metal target having a long side substantially equal to the wheel diameter and a short side shorter than the wheel radius. And the metal target is arranged above the wheel design surface so that the horizontal direction of the longitudinal direction and the wheel diameter coincide with each other and the wheel design surface. And while rotating around this wheel center axis as a center of rotation, by sputtering, the wheel design surface always forms a film formation site in the wheel center, and further toward the wheel outer edge from the wheel center. Periodic film formation sites where the film thickness gradually decreases are formed. Here, the wheel design surface has an appearance in which the color of the colored base layer is gradually emphasized from the central portion where the metallic tone is emphasized toward the outer edge portion. By forming the metal reflective film in this manner, an aluminum alloy wheel having the above-described configuration according to the first aspect of the present invention can be appropriately obtained. That is, according to the surface brightening treatment method of the present invention, it is possible to easily and appropriately obtain a molded product (for example, an automobile wheel) that expresses a gradation-like appearance that has not been heretofore described. And this molded article can have a high designability as mentioned above.

  In the reflective film forming step described above, sputtering can be controlled and executed so that the film forming portion always has a film thickness that allows the colored base layer to pass therethrough. In this method, the transmittance of the colored base layer can be appropriately set by always determining the film thickness of the film formation site. For example, the metallic tone may be emphasized so that the colored base layer has a slight transmittance, and the gradation tone of the periodic film forming portion may be relatively strengthened. Alternatively, by increasing the transmittance, it is possible to make the appearance of the metal reflective film as a whole with the color of the colored base layer being relatively emphasized.

  On the other hand, a method is also proposed in which the reflective film forming step controls the sputtering so that the constant film forming portion on the surface of the base material has a film thickness that does not transmit the colored base layer. Here, when sputtering is performed on the surface of the rotating base material, the film thickness of the constant film formation portion that is always covered with the metal target is usually smaller than the periodic film formation portion that is periodically covered with the metal target. It will be formed thick. Therefore, the sputtering time and the like are appropriately set so that the film thickness of this constant film formation site is a thickness that does not pass through the lower colored base layer. At the constant film formation site formed by such a method, the color of the colored base layer does not appear at all, and only the metallic tone of the metal target is clearly expressed. As a result, the color difference between the constant film formation portion and the thinnest portion of the periodic film formation portion is increased, and the gradation expressed in the periodic film formation portion can be emphasized. If this method is applied to the surface treatment of an aluminum alloy wheel in the same manner as described above, an automotive wheel having higher designability can be obtained as described above.

  In the above-described surface brightening method, there is also proposed a method in which the reflection film forming step forms an undeposited portion that is not covered with a metal target and is not formed on the surface of the base material. In such a method, an undeposited portion that is not formed by sputtering is formed by allowing a portion of the base material surface not covered by the metal target to be present regardless of the rotation of the base material. This is the method. Therefore, the metal reflection film does not exist in this undeposited portion. By performing the surface brightening treatment in this way, a large color difference is produced between the metallic tone in the thickest part of the metal reflecting film and the color of the colored base layer directly expressed in the non-deposited part. Can be produced, and the above-described gradation can be further emphasized. For this reason, for example, when the color of the colored base layer is completely different from the metal color, an unprecedented multicolor appearance can be expressed by the metallic tone and the color of the colored base layer. . By applying this surface brightening method to an aluminum alloy wheel, the color difference between the wheel center and the wheel outer edge is large. It is possible to obtain a wheel having high design properties.

As described above , the first molded article subjected to the surface brightening treatment according to the present invention includes a colored base layer obtained by applying a colored paint of a predetermined color on the surface of a metal base material or a resin base material, and the colored base. On the layer, there is provided a metal reflective film on which a pure metal or a metal alloy is formed so that the film thickness gradually decreases from the center part of the base material toward the outer edge of the base material. . Further, the second molded article subjected to the surface brightening treatment according to the present invention includes a colored base layer obtained by applying a colored paint of a predetermined color on the surface of a metal base material or a resin base material, and the colored base layer. And a metal reflective film formed with a pure metal or metal alloy so that the film thickness gradually decreases from the outer edge of the base material toward the center of the base material. In the metal reflective film having such a configuration, the transmittance increases as the film thickness decreases, and the color of the colored base layer decreases as the film thickness decreases from the metal tone of the metal target in the thicker part. Gradation that emphasizes gradually will be expressed. Therefore, for example, when it is adapted to an automobile wheel, the design surface of the design surface gradually changes from the wheel center toward the wheel outer edge (or from the wheel outer edge toward the wheel center). It has gradation and multicolor appearance. Further, the gradation expressed on the wheel for an automobile is visible even when the automobile is rotating while the automobile is running. Thus, an automobile wheel to which such a configuration is applied has an unprecedented appearance, can exhibit high design properties, and its value is remarkably improved.

Here, in the first molded article described above, the metal reflective film formed on the colored base layer has a thickness that does not transmit through the colored base layer at the center of the base material. The configuration. Further, in the second molded article described above, the metal reflective film formed on the colored base layer has a thickness that does not transmit through the colored base layer at the outer edge of the base material. And In such a configuration, only the metallic tone by the metal target is expressed at the central portion of the base material of the first molded product and the outer peripheral edge portion of the base material of the second molded product , and the gradation can be emphasized. The effect of the present invention is further enhanced.

  On the other hand, the present invention provides a colored base by applying a colored paint of a predetermined color on the surface of a metal base material or a resin base material as a surface brightening treatment method for performing surface treatment on the above-mentioned molded product subjected to surface brightening treatment. After performing the base layer forming step for forming the layer, the metal base material or the resin base material on which the colored base layer is formed is arranged so that the surface of the base material faces a metal target made of pure metal or metal alloy. And rotating at a predetermined speed with an axis substantially perpendicular to the surface of the base material as a center of rotation, and forming a periodic film forming portion on the base material surface that is periodically covered and sputtered by a metal target along with the rotation, This is a method of performing a reflection film forming step in which a metal reflection film is formed. By such a method, it is possible to form a periodic film-forming site where the film thickness gradually increases (or decreases) according to the distance from the rotation center, and it is possible to obtain a molded product that expresses a gradation-like appearance appropriately and easily. it can. For example, if the surface brightening treatment method is applied to an automobile wheel, an automobile wheel having high designability can be obtained as in the present invention described above.

  Here, in this surface brightening treatment method, the reflective film forming step is performed so that the colored base layer does not transmit the thickest part in the periodic film forming portion on the surface of the base material. In the method of controlling and executing, only the metallic tone of the metal target is clearly expressed in the thickest part of the film thickness, and the gradation tone expressed in the part of gradually decreasing film thickness is emphasized. Can do. Therefore, the wheel which has higher designability can be obtained by applying to the wheel for motor vehicles.

  Further, in the surface brightening method described above, the reflective film forming step forms a periodic film formation portion that is periodically covered and sputtered by the metal target on the surface of the base material, and always covers the metal target. In the method in which the continuous film formation site to be sputtered is formed and the metal reflective film is formed, the periodic film formation site in which the film thickness gradually increases or decreases, and the constant film formation in which the film thickness is constant. A membrane site can be formed. Therefore, it is possible to appropriately and easily obtain a molded product expressed in an unprecedented appearance, which is composed of a constant film formation portion where the metallic tone of the metal target is emphasized and a gradation-like periodic film formation portion. For example, if the surface brightening treatment method is applied to an automobile wheel, an automobile wheel having high designability can be obtained as in the present invention described above.

  Here, in this surface brightening treatment method, the method of controlling the sputtering so that the reflective film forming step has a film thickness at which the colored base layer does not pass through the constant film forming portion on the surface of the base material. In this case, since only the metallic tone of the metal target is always clearly expressed at the film forming portion, the gradation tone expressed at the periodic film forming portion can be emphasized. Therefore, the wheel which has higher designability can be obtained by applying to the wheel for motor vehicles.

  In such a surface brightening method, in the reflective film forming step, an undeposited portion that is not covered with a metal target and is not deposited is formed on the base material surface. By providing an undeposited portion in which the color of the color is directly expressed, the difference in color from the metallic tone of the metal target can be increased, and the above-described gradation can be further emphasized. By applying this surface glitter processing method to an automobile wheel, as described above, even when the vehicle is rotating during traveling, a gradation can be expressed more clearly and a wheel that exhibits high designability can be obtained. it can.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.
In this embodiment, casting or the like is performed so as to obtain an aluminum alloy wheel 1 (1x in FIG. 4 (b), 1y in FIG. 6 (b)) having the basic surface treatment configuration shown in FIG. A surface treatment process is performed on the design surface (see design surface 2x in FIG. 4B and design surface 2y in FIG. 6B) of the wheel base material 1A of the molded aluminum alloy wheel for automobiles. Here, the aluminum alloy wheel 1 (1x in FIG. 4 (b), 1y in FIG. 6 (b)) is the molded product according to the present invention, and the wheel base material 1A is the metal base material according to the present invention.

In the aluminum alloy wheel 1 (1x in FIG. 4 (b), 1y in FIG. 6 (b)), the surface treatment steps described above will be described in accordance with the treatment order.
First, a chemical conversion treatment that forms a film (not shown) on the design surface by applying degreasing / cleaning and a predetermined treatment liquid as a pretreatment to the design surface of the wheel base material 1A that has been adjusted to a predetermined wheel shape. Apply. By this chemical conversion treatment, the wheel base material 1A is protected to enhance the corrosion resistance, and the adhesion of the powder coating applied thereon is improved. And after apply | coating a powder coating material to this pre-processed surface, it is baked and dried and the powder coating layer 3 of about 70-150 micrometers is formed. The powder coating layer 3 hides the textured surface of the wheel base material 1A from casting or forging to form a smooth surface and enhances the smooth thickness, gloss and gloss. Thereafter, a colored paint of a predetermined color is applied on the powder coating layer 3 and then baked and dried (or in an undried state), so that the colored base layer 4 serving as the base of the metal reflective film 6 has a predetermined thickness. (About 15 to 25 μm). As will be described later, the predetermined color of the colored base layer 4 is transmitted through the periodic film formation portion of the metal reflection film 6 so that the wheel 1 exhibits gradation, and directly appears at the non-film formation portion. ing. In the present embodiment example, the colored base layer 4 has a black color. Note that the periodic film formation part and the non-film formation part of the metal reflection film 6 are the main parts of the present invention, and will be described in detail later. The process of forming the colored base layer 4 that expresses the color of the aluminum alloy wheel 1 in this way is the foundation layer forming process according to the present invention.

  A clear paint is applied onto the colored base layer 4 and baked and dried to form the base coat layer 5 with a predetermined thickness (about 15 to 25 μm). By providing this clear base coat layer 5, the glossiness of the colored base layer 4 is enhanced.

Next, a reflection film forming process for forming the metal reflection film 6 according to the main part of the present invention will be described.
As described above, the wheel 1B in which the colored base layer 4 is formed on the design surface of the wheel base material 1A to form the base coat layer 5 is applied to the metal reflective film 6 on the base coat layer 5 by the sputtering apparatus 10 shown in FIG. Sputtering is performed (see FIG. 1). Here, the sputtering apparatus 10 holds the wheel 1B in the vacuum vessel 11, the metal target 12 disposed on the ceiling inside the vacuum vessel 11, and the wheel 1B. 1B is provided with a wheel arrangement member 14 that is rotated at a predetermined rotation speed by a rotation drive device 15 with the wheel center axis P as a rotation center. And this wheel arrangement | positioning member 14 is arrange | positioned so that the lower surface of the metal target 12 and the design surface 2 of the wheel 1B may face substantially parallel, Furthermore, the horizontal direction position with respect to the metal target 12 can be changed. Provided (not shown). Here, the metal target 12 is provided so as to be electrically connected to a negative electrode (not shown). On the other hand, the wheel 1 </ b> B is grounded via a wheel arrangement member 14. The wheel arrangement member 14 is provided so that the wheel 1B carried into the vacuum vessel 11 by a conveying device (not shown) is arranged at a predetermined position facing the metal target 12. When the sputtering is completed, the vacuum vessel 11 is carried out by a transfer device (not shown).

  Further, the sputtering apparatus 10 is provided with a suction port 17 connected to a vacuum pump (not shown) for bringing the inside of the vacuum vessel 11 into a vacuum state. In addition, a gas inlet 16 through which argon gas flows into the vacuum vessel 11 is provided.

  In the present embodiment example, as described above, the wheel arrangement member 14 is provided so that the horizontal position of the wheel 1B with respect to the metal target 12 can be appropriately set. In this embodiment, as Example 1, the metal target 12 is sputtered at a position where the portion covering the design surface 2 periodically changes as the wheel 1B rotates. (See FIG. 3). Moreover, as Example 2, the metal target 12 is positioned so as to include both a part where the part covering the design surface 2 periodically changes with the rotation of the wheel 1B and a part where the part covering always exists. It is set and sputtered (see FIG. 5). Hereinafter, each example will be described.

Example 1
In the sputtering apparatus 10 described above, a metal target 12 made of a rectangular parallelepiped aluminum alloy is disposed. Here, the metal target 12 is composed of a long side L in the longitudinal direction substantially equal to the outer diameter of the wheel 1B and a short side T in the width direction shorter than the radius of the wheel 1B (see FIG. 3). ).

  When the wheel 1B on which the above-described base coat layer 5 is formed is carried into the vacuum vessel 11 of the sputtering apparatus 10 as described above, the wheel 1B is gripped and fixed at a predetermined position. Here, in Example 1, as shown in FIG. 3, the rectangular parallelepiped metal target 12 and the wheel 1B are not covered by the metal target 12 without covering the central portion of the wheel 1B. It arrange | positions so that it may become a position which covers a peripheral part partially.

The inside of the vacuum vessel 11 has a degree of vacuum of about 1 × 10 ⁻³ Pa, and argon gas as a process gas flows in from the gas inlet 16 at a flow rate of about 5.1 × 10 ⁻¹ Pa · m ³ / s. At the same time, the pressure in the vacuum vessel 11 is maintained at about 1.0 Pa. In this way, after the argon gas atmosphere in a relatively low pressure state is formed, the wheel 1B held at a predetermined position by the wheel arrangement member 14 is rotated at a predetermined rotation speed, and the metal target 12 and the wheel 1B are rotated. Sputtering is performed by passing a current from the negative electrode to the metal target 12 so that a predetermined voltage is generated therebetween.

  In the sputtering of the first embodiment, with the rotation of the wheel 1B, the portion of the design surface 2 of the wheel 1B covered by the metal target 12 is sequentially changed in the wheel circumferential direction. Here, the time that the outer peripheral edge of the wheel of the design surface 2 is covered with the metal target 12 per rotation is the longest, and the time that the wheel is covered toward the center gradually decreases. As described above, the periodic film formation portion 21x according to the present invention is formed in the region of the design surface 2 of the wheel 1B that is periodically covered with the metal target 12 as the wheel rotates. In addition, in the center side area | region rather than the longitudinal direction side edge of the wheel center side of the metal target 12 of the wheel 1B, it is not covered with the metal target 12 irrespective of rotation of this wheel 1B. Thus, as shown in the conceptual diagram of FIG. 4 (A), the outer periphery of the wheel is formed on the base coat layer 5 of the wheel 1B by being periodically covered with the metal target 12 and sputtered with the rotation. A periodic film forming portion 21x having the largest film thickness at the portion and gradually decreasing in the center direction is formed. The central portion of the design surface 2 is an undeposited portion 22 where the base coat layer 5 is exposed. In this way, the metal reflective film 6x is formed.

  In the metal reflective film 6x, the film thickness formed on the outer peripheral edge of the wheel is the thickest, and the film thickness of this part is such that it does not transmit the black color of the colored base layer 4 described above at all. It is formed into a film. This film thickness is controlled by adjusting the rotation speed of the wheel 1B, the sputtering time, and the like. In Example 1, the thickness of the thickest part is controlled to be about 0.1 μm. Since the film thickness gradually decreases from the thickest part toward the center, the transmittance gradually increases, and the black color of the colored base layer 4 changes to the metal reflective film 6x. From the aluminum color, it becomes stronger gradually. And in the non-deposition site | part 22 of the wheel center part, the black system color of the coloring base layer 4 appears directly. That is, by forming the metal reflection film 6x, a gradation that gradually changes from the black system color of the non-deposition site 22 at the center of the wheel to the aluminum color of the outer peripheral edge of the wheel is expressed.

  When the metal reflective film 6x is thus formed, the current is stopped and the rotation of the wheel 1B is stopped, whereby the surface brightening process step by sputtering is completed. Then, the wheel 1B on which the metal reflection film 6x is formed is carried out of the vacuum vessel 11. Next, as shown in FIG. 1, a clear primer coating is performed on the metal reflective film 6x (the base coat layer 5 in the case where the film is not formed 22) to form a primer layer 7 of about 5 to 10 μm. . The primer layer 7 is excellent in affinity between the metal reflective film 6X and the top clear coat layer 8 coated on the primer layer 7, and a state in which the primer layer 7 is in close contact with both is formed. Further, the primer layer 7 can protect the metal reflective film 6X (and the colored base layer 4) and enhance rust prevention. Thereafter, a top clear coat is applied on the surface of the primer layer 7 and then baked and dried to form a top clear coat layer 8 having a thickness of about 20 to 30 μm. The top clear coat layer 8 protects the metal reflective film 6X (and the colored base layer 4) and improves the corrosion resistance. Furthermore, since the top clear coat layer 8 has translucency, it can exhibit high glossiness of the metal reflective film 6X and the colored base layer 4 together with the clear primer layer 7. Thus, the protective effect of the metal reflection film 6 is enhanced by forming the primer layer 7 and the top clear coat layer 8 on the metal reflection film 6. In addition, since the top clear coat layer 8 is formed on the surface of the metal reflective film 6 via the primer layer 7, the adhesion between the layers is increased as described above. For this reason, even when an impact or the like is received from the surface side, it is possible to prevent the separation between the layers and to exhibit high durability.

  In this way, in the aluminum alloy wheel 1x in which the design surface of the wheel base material 1A is surface-treated, as shown in FIG. It has a design surface 2x on which a gradation-like appearance in which the color gradually changes to the aluminum color of the portion is expressed.

(Example 2)
Even in Example 2, sputtering is performed using the metal target 12 made of the same rectangular aluminum alloy as in Example 1 (see FIG. 5). In the second embodiment, as shown in FIG. 5, the wheel 1 </ b> B carried into the vacuum vessel 11 and held by the wheel arrangement member 14, the metal target 12, the longitudinal direction of the metal target 12, and the diameter of the wheel 1 </ b> B. Are arranged so that they overlap.

In the same manner as in the first embodiment, the inside of the vacuum vessel 11 has a degree of vacuum of about 1 × 10 ⁻³ Pa, and argon gas is supplied as a process gas at a flow rate of about 5.1 × 10 ⁻¹ Pa · m ³ / s. The pressure in the vacuum vessel 11 is maintained at about 1.0 Pa, thereby forming a relatively low pressure argon gas atmosphere. Then, while rotating the wheel 1B currently hold | gripped by the wheel arrangement | positioning member 14 with a predetermined | prescribed rotational speed, sputtering is performed.

  Here, the wheel center portion corresponding to the width of the metal target 12 (the length of the short side T) of the wheel 1B is always covered by the metal target 12 regardless of the rotation. Further, in the region outside the width of the metal target 12, the portion covered by the metal target 12 is sequentially shifted in the wheel circumferential direction with rotation, and as the distance from the rotation center (wheel center axis P) increases. The time covered with the metal target 12 per rotation is shortened. Thus, by being covered with the metal target 12 and being sputtered, a constant film forming portion 23 having a substantially constant film thickness is formed at the center of the wheel as shown in FIG. On the outside of 23, there is formed a periodic film forming part 21y that is continuously formed from the film forming part 23 and whose film thickness gradually decreases in the radial direction. In this way, the metal reflection film 6y is formed. In the second embodiment, the periodic film forming portion 21y is formed up to the outer peripheral edge of the wheel, and the non-film forming portion 22 as in the first embodiment does not exist.

  In the metal reflection film 6y, the film thickness of the film forming portion 23 is always larger than that of the periodic film forming portion 21y, and the thickness of the colored base layer 4 does not transmit the black system color at all. It is formed into a film. The film thickness of the constant film forming portion 23 is controlled by adjusting the rotation speed of the wheel 1B, the sputtering time, and the like. In the second embodiment, the film thickness of the constant film forming portion 23 is controlled to be about 0.1 μm. This constant film formation portion 23 is aluminum-colored, and the periodic film formation portion 21y gradually increases in thickness toward the outer radial direction, so that the transmittance increases, and the black base of the colored base layer 4 The color is gradually increased from the aluminum color. That is, by forming the metal reflection film 6y, the aluminum color of the constant film formation portion 23 at the center of the wheel and the aluminum color of the periodic film formation portion 21y are relatively strong from the aluminum color toward the wheel radial direction. A gradation that gradually changes to the black color is expressed.

  When the surface brightening process by sputtering is completed, the primer layer 7 and the top clear coat layer 8 are sequentially formed on the metal reflective film 6y, and the wheel base material 1A is subjected to the surface treatment in the same manner as in Example 1 described above. An aluminum alloy wheel 1y is obtained. Thus, in the aluminum alloy wheel 1y having the surface treated on the design surface of the wheel base material 1A, the design surface 2y is directed outward from the aluminum color at the center as shown in FIG. Thus, it has a design surface 2y on which a gradation-like appearance in which the color gradually changes so that the black system color becomes stronger.

  As described above, the aluminum alloy wheels 1x and 1y according to the first and second embodiments have an unprecedented gradation-like appearance in which the color gradually changes between the wheel center portion and the wheel outer edge portion. Design surfaces 2x and 2y are formed (see FIGS. 4B and 6B). Furthermore, since the color tone changes concentrically from the center of the wheel toward the outer peripheral edge, even when the wheels 1x and 1y are rotating while the vehicle is running, The gradation can be visually recognized. Therefore, such aluminum alloy wheels 1x and 1y can exhibit extremely high designability, and have a large market value as an automobile wheel. Further, such a gradation-like appearance is formed relatively easily by rotating the wheel 1B on which the colored base layer 4 is formed and devising the arrangement of the metal target 12 using a general sputtering apparatus. Therefore, it has an excellent advantage that it can be achieved without complication of processing steps and cost increase. In particular, as in Examples 1 and 2, the design surfaces 2x and 2y in which the blackness is expressed by the aluminum color and the black system color used for the colored base layer 4 have a heavy and elegant atmosphere. It is also supposed to give a sense of quality.

  Further, in the above-described second embodiment, the method is such that the film formation portion 23 and the periodic film formation portion 21y are always formed on the design surface 2y. It is also possible to adopt a method in which it is formed in a part. This can be achieved by using a metal target having a long side L that is shorter than the outer diameter of the wheel.

  Further, in the above-described first embodiment, the periodic film forming portion 21x may be formed so that the thickest portion of the periodic film forming portion 21x has a thickness that transmits the black color of the colored base layer 4. good. Similarly, in Example 2, the film may be formed so that the film thickness of the film formation portion 23 is always the thickness that transmits the black color of the colored base layer 4. The transmittance of each colored base layer 4 can be appropriately set depending on the film thickness. For example, if the film thickness is slightly transmitted through the colored base layer 4, an appearance in which the black color is slightly expressed even in the portion having the strongest aluminum color. Alternatively, if the film thickness is set so as to increase the transmittance of the direct color base layer 4, the entire design surface has an appearance in which the black system color is emphasized, and a thick and elegant atmosphere can be further expressed.

  Moreover, in Example 1 and Example 2, although it is the structure which sputter | sputtered using the rectangular parallelepiped metal target 12 which consists of the long side L and the short side T, in addition to this, the long side L and the short side By changing the length of T or using metal targets of various shapes such as L-shape and T-shape, it is possible to properly form a constant film-forming site, a periodic film-forming site, and a non-film-forming site. it can. Thereby, the occupation area of each part can be changed, and the film thickness change rate of the periodic film forming part can be set in various ways.

  In the above-described embodiment, the present invention is applied to the aluminum alloy wheel 1, but the present invention can also be applied to other uses. In addition to the metal base material such as the wheel base material 1A, the resin is used. It can also be applied to base materials. For example, the present invention can be applied to various molded products that are plated, such as automobile bumpers, mobile phones, and notebook computer casings. Moreover, depending on the use to utilize, a powder coating layer may not be formed.

It is explanatory drawing which shows each surface treatment layer formed in the design surface of 1 A of wheel base materials based on the molded article surface-brilliantly processed by this invention . It is explanatory drawing showing the sputtering apparatus 10 which performs sputtering on the wheel 1B based on the molded article by which surface brightening processing was carried out by this invention . In the sputtering apparatus 10, it is explanatory drawing which represented planarly the arrangement | positioning of the wheel 1B and the metal target 12 in Example 1. FIG. It is the conceptual diagram showing the film thickness of (a) metal reflective film 6x of Example 1, and the external view showing the design surface 2x of (b) aluminum alloy wheel 1x. In the sputtering apparatus 10, it is explanatory drawing which planarly represented arrangement | positioning of the wheel 1B and the metal target 12 in Example 2. FIG. It is the conceptual diagram showing the film thickness of (a) metal reflective film 6y of Example 2, and the external view showing the design surface 2y of (b) aluminum alloy wheel 1y.

Explanation of symbols

1, 1x, 1y Aluminum alloy wheel 1A Wheel base material 2, 2x, 2y Design surface 4 Colored base layer 6, 6x, 6y Metal reflecting film 12 Metal target 21x, 21y Periodic film forming part 22 Non-film forming part 23 Constant film forming part

Claims (5)

After performing a base layer forming step of forming a colored base layer by applying a colored paint of a predetermined color on the surface of the metal base material or the resin base material,
The metal base material or resin base material on which the colored base layer is formed is disposed so that the base material surface faces a metal target made of pure metal or metal alloy, and an axis substantially orthogonal to the base material surface is the center of rotation. Rotate at a predetermined speed as
A step of forming a reflective film is formed by forming a periodic film-forming portion on the surface of the base material that is periodically covered and sputtered by a metal target with the rotation, and forming a metal reflective film. Surface brightening treatment method. The reflective film forming step forms a periodic film formation site that is periodically covered and sputtered by the metal target on the surface of the base material, and a constant film formation site that is always covered and sputtered by the metal target. 2. The surface brightening method according to claim 1 , wherein a metal reflective film is formed. According reflection film forming step, the most film thicker portion having a thickness within the period the film formation region of the base metal surface, the colored base layer to a thickness that does not transmit, characterized in that the controls performed sputtering Item 6. The surface brightening treatment method according to Item 1 . 3. The surface brightening process according to claim 2 , wherein the reflective film forming step controls the sputtering so that the colored base layer does not transmit through the constant film forming portion on the surface of the base material. Method. Reflection film forming step, the base material surface is not covered with the metal target, according to any one of claims 1 to 4, characterized in that so as to form a ungrown sites that are not deposited Surface glitter treatment method.

Images