| 摘要 |
1358709 Colouring anodized aluminium CEGEDUR GP 23 Nov 1971 [26 Nov 1970] 54337/71 Heading C7B Anodized Al metal or alloy is coloured e.g. bronze by A.C. electrolysis with a Ni counterelectrode in a bath containing 50 to 150 g/l NiSO 4 .7H 2 O and 45 to 60 g/l H 3 BO 3 and having a pH 3À5 to 5À2 at 20 to 35‹C and C.D. 0À7 to 1À5 A/dm<SP>2</SP> of Al surface for 5 to 20 minutes. The bath may also contain e.g. 30 g/l (NH 4 ) 2 SO 4 with H 2 SO 4 or NH 3 added to maintain the pH value. Anodizing may be effected by A. C. electrolysis in an aqueous acid solution containing 25 g/l NiSO 4 .7H 2 O, 25 g/l H 3 BO 3 and 15 g/l (NH 4 ) 2 SO 4 , or D.C. electrolysis in a 20% H 2 SO 4 solution. Prior to anodizing, the Al may be degreased and scoured. |
