Method for forming colorless or colored pattern having shade difference on an aluminum or aluminum alloy article
AssigneeNippon Light Metal Company, Ltd.
InventorToshihiko Sato
Life of this patent
Estimating the term…
Abstract
Colored pattern having shade difference on an aluminum or aluminum alloy article is formed by anodically oxidizing said article in a conventional manner, and applying the anodically oxidized aluminum or aluminum alloy article to a voltage 5-190 V higher than the voltage applied in the anodic oxidation at a portion corresponding to the pattern in an electrolytic bath to increase thickness of barrier layer and then coloring the thus treated article in a solution containing a metal salt.
Claims14
A method of forming a colored pattern on an aluminum or aluminum alloy article which comprises:
- A. anodically oxidizing said article at a voltage of from 10-120 volts;
- B. forming a barrier layer on those areas not to be colored by subjecting said areas to a second anodic oxidation at a voltage of from 15-200 V wherein said voltage is at least 5 volts greater than the voltage applied in Step A;
- and
- C. electrolytically coloring said article utilizing an electrolytic metal salt bath at a voltage of from 5-75 volts wherein only those areas not subjected to said second anodic oxidation are colored.
A method of forming a colored pattern on an aluminum or an aluminum alloy article which comprises:
- A. anodically oxidizing said article at a voltage of from 10-120 volts;
- B. electrolytically coloring said article utilizing an electrolytic metal salt bath at a voltage of from 5-75 volts, and
- C. forming a barrier layer on those areas wherein the amount of metal deposited by said electrolytic coloring is to be reduced by subjecting said areas to a second anodic oxidation at a voltage of from 15-200 V wherein said voltage is at least 5 volts greater than the voltage applied in Step A.
Dependencies are inferred from the claim text.