首页>
外国专利>
A method for electrodepositing copper or copper alloy foil with chromium-zinc ion to impart discoloration resistance to the foil and a basic electrolyte solution for electrodepositing a discoloration preventing film on copper or copper alloy foil.
A method for electrodepositing copper or copper alloy foil with chromium-zinc ion to impart discoloration resistance to the foil and a basic electrolyte solution for electrodepositing a discoloration preventing film on copper or copper alloy foil.
The present invention relates to techniques for enhancing discoloration and oxidation resistance of copper and copper-based alloy materials. A chromium-zinc film is electrolytically applied to the copper or copper-based alloy surface using the caustic electrolyte solution 16. The coated material is then washed with an aqueous solution 32 containing phosphates of alkali or alkaline earth metals or borates of alkali or alkaline earth metals. The pH of the cleaning liquid is maintained at about 5 to about 12, preferably about 7 to about 10.
展开▼
