JPH0369988B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for imparting a golden color to plastic surfaces.

In cases such as ornaments or watch cases,
To give a plastic surface a golden luster, generally an aluminum film is formed on the plastic base by vapor deposition or sputtering, then a yellow paint is applied on top of that, and finally a transparent protective coating is formed. Although this method is common, it has the drawback of requiring a large number of steps.

Furthermore, the use of metal oxide films such as titanium oxide as decorative films has been proposed in the past, as seen in Japanese Unexamined Patent Publication No. 54-66385, but conventionally, metal oxide films were formed on the order of microns. death,
The color tone of the metal oxide film itself (e.g. titanium oxide:
It is common to use navy blue, zirconium oxide (pale white, etc.) as the exterior color. It is also known that a golden-yellow film can be obtained using titanium oxide by adjusting the film thickness and reaction atmosphere, but the conditions for obtaining a golden-yellow film are extremely limited. Since the range is narrow, it is necessary to set strict conditions such as film thickness and reaction atmosphere, which makes manufacturing complicated and unsuitable for mass production.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plastic surface with a golden luster very easily.

To explain an example, a yellow ABS resin was used as the plastic material, and reactive sputtering of titanium was performed on the surface of the plastic in a vacuum bell gear with argon and a small amount of oxygen introduced as gases. The conditions at that time are as follows.

Reactive sputtering condition target Titanium metal ultimate vacuum 5×10 ^-5 Toor or less Oxygen partial pressure (2~8)×10 _-4 Toor Argon partial pressure 5×10 _-3 Toor High frequency input power 800W Processing time 2~3min And When a titanium oxide film of 200 to 300 angstroms was formed on the surface of the plastic under these conditions, the surface exhibited a golden luster. This is a combination of the fact that the titanium oxide film in the above film thickness range is transparent with a pale bluish tinge and has a metallic luster, and the color of the plastic material (i.e. yellow or a color close to it). It is thought to have a golden luster.

In addition, when metal nickel, metal copper, etc. are used as a sputtering target in addition to metal titanium, and a nickel oxide film or copper oxide film is formed on the above-mentioned plastic material, they can be sputtered under almost the same conditions as in the above-mentioned example. It was confirmed that a golden luster could be obtained by setting the thickness of the oxide film to 200 to 300 angstroms. Also, plastics other than ABS can be used as long as they are yellow or a color close to yellow. Further, the above processing conditions are only an example of conditions for obtaining a film thickness of 200 to 300 angstroms, and can be changed as appropriate.

According to the present invention described above, it is possible to give a golden luster to the plastic surface only by the sputtering process, and furthermore, the conditions are set such that the oxide film exhibits a transparent film thickness (i.e., the film thickness is 200 to
300 angstrom range), making manufacturing extremely easy. Furthermore, the present invention does not use the color tone of the metal oxide film itself as the exterior color, but combines the yellow or similar color of the base plastic with the bluish transparency and metallic luster of the metal oxide film. Therefore, as long as the thickness of the oxide film is within the above range, the same golden color can be imparted even if the conditions for forming the metal oxide film vary slightly. possible and suitable for mass production. Furthermore, since the film thickness is extremely thin compared to the thickness of a decorative oxide film formed by conventional sputtering, consumption of target material and processing time are reduced, which is advantageous in terms of cost.

Claims (1)

[Claims] 1. Using argon, a small amount of oxygen, and an introduced gas, one of titanium, nickel, and copper is reactively sputtered onto the surface of yellow or similar-colored plastic to form an oxide film of the metal on the plastic surface for 200 minutes. A method of imparting a golden color to plastic surfaces characterized by forming them to a thickness of ~300 angstroms.