EP 0399169 A3 19910123 - CHEMICAL PROCESS TO AVOID A RAINBOW EFFECT, PROVOKED BY AN OXIDE LAYER THAT IS CAUSED DURING THE POLISHING OF PIECES OF ALUMINIUM OR PIECES OF ALUMINIUM ALLOYS
Title (en)
CHEMICAL PROCESS TO AVOID A RAINBOW EFFECT, PROVOKED BY AN OXIDE LAYER THAT IS CAUSED DURING THE POLISHING OF PIECES OF ALUMINIUM OR PIECES OF ALUMINIUM ALLOYS
Publication
Application
Priority
DE 3917186 A 19890526
Abstract (en)
[origin: EP0399169A2] A description is given of a chemical process for avoiding a rainbow effect provoked by the oxide layer produced during the polishing of aluminium or aluminium-alloy parts. In the process, the parts are degreased or cleaned in a first process step and given an electrolytic alkaline polish in a second process step. The process is distinguished by the fact that, after polishing, the pieces are subjected to a further treatment in which they are first rinsed in water, then exposed to a chromic acid solution containing about 50 g/l of CrO3 at about 98 DEG C for about three minutes, and finally rinsed in a sodium hydrogensulphite solution.
IPC 1-7
IPC 8 full level
C25D 11/24 (2006.01); C25F 3/20 (2006.01)
CPC (source: EP US)
C25F 3/20 (2013.01 - EP US)
Citation (search report)
- [Y] US 2647865 A 19530804 - MANFRED FREUD HERBERT
- [Y] FR 1003126 A 19520314
- [Y] GB 606240 A 19480810 - CIE DE PROD CHIM ET ELECTRO ME
- S. WERNICK et al.: "The Surface Treatment and Finishing of Aluminium and its Alloys", Ausgabe 1, Band 5, 1987, Seiten 73-77, Finishing Publications Ltd, Teddington, Middlesex, GB
Designated contracting state (EPC)
BE DE ES FR GB IT SE
DOCDB simple family (publication)
EP 0399169 A2 19901128; EP 0399169 A3 19910123; EP 0399169 B1 19930811; DE 3917186 A1 19901129; DE 3917186 C2 19920625; DE 59002260 D1 19930916; JP H0313598 A 19910122; JP H0579759 B2 19931104; US 5009756 A 19910423
DOCDB simple family (application)
EP 90105558 A 19900323; DE 3917186 A 19890526; DE 59002260 T 19900323; JP 13554190 A 19900528; US 52758790 A 19900523