摘要 |
The present invention provides a method of coating a tin article with a trivalent chromium oxide and/or hydroxide in which the tin article is contacted with a trivalent chromium protective coating composition having an acid pH of about 2.0 to 3.0 and the trivalent chromium oxide and/or hydroxide is deposited on the article by electrolysis, the electroplating composition and an article of tin coated with a protective trivalent chromium oxide and/or hydroxide. |