| 摘要 |
1482390 Colouring anodized aluminium NORSK HYDRO AS 24 Nov 1975 48227/75 Heading C7B An anodized Al (alloy) article is coloured by passing A.C. between it and a counter electrode, e.g. of stainless steel tube or Cu wire, whilst immersed in an acid solution comprising a mixture of a Sn, Cu and/or Ni salt and an In salt. The salts may be sulphates, chlorides or nitrates. H 2 SO 4 and MgSO 4 as electrolyte, 3, 4-sulphophthalic or sulphosalicylic acid as complex former, and/or sulphamic, maleic, tartaric or citric acid as inhibitor may be added to the solution. The article may be D.C. anodized in a solution containing H 2 SO 4 and Al 2 (SO 4 ) 3 and rinsed in H 2 SO 4 -acidified water prior to colouring. A.C. colouring may be effected in two baths, the second being made up of Sn, Cu and/or Ni salt not used in the first bath, together with an In salt. Specification No. 1355619 is referred to. |
