Improvements in or relating to the production of colour effects on or in the oxide film of anodised aluminium or aluminium alloy

摘要

593,239. Colouring aluminium and alloys. CAMPBELL, W. J. June 5, 1944, No. 13092/45. Divided out of 584,940. [Class 93] Colour effects are produced on the oxide film of an anodised aluminium or aluminium alloy article by a process in which a resist which is not completely effective is applied directly to the oxide film. In a modification a completely effective resist may be applied and then made only partially effective. Specified resists are natural or synthetic resins, waxes, animal fat, cellulose lacquers, bitumen, and oils. In examples (1) areas of anodised aluminium are coated with a cresol-formaldehyde complete resist in turpentine and dried. A benzene moistened brush is used to spread the resist which is then stored, dyed, rinsed and dried In modifications the aluminium may be dyed before applying the resist and unprotected colour removed with nitric acid, and more than one layer of colour, selectively removed by nitric acid, may be used for this dyeing; (2) as in (1) using a cresol-formaldehyde partial resist and (3) as in (1) or (2) using as resists (a) cresol-formaldehyde, turpentine, benzene, and raw linseed oil and (b) cresolformaldehyde, benzene and castor oil.