EP 0320952 A3 19900131 - PROCESS FOR THE ELECTROLYTIC COLOURING OF ANODICALLY OBTAINED OXIDE LAYERS ON ALUMINIUM OR ALUMINIUM ALLOYS
Title (en)
PROCESS FOR THE ELECTROLYTIC COLOURING OF ANODICALLY OBTAINED OXIDE LAYERS ON ALUMINIUM OR ALUMINIUM ALLOYS
Publication
Application
Priority
DE 3743113 A 19871218
Abstract (en)
[origin: EP0320952A2] The invention discloses a process for electrolytically colouring anodic oxide layers on aluminium or its alloys by means of alternating current in electrolytes containing metal salt. The process comprises two stages, direct current being applied in the first stage and alternating current in the second stage and a notable feature is that, instead of direct current, a modified alternating current which contains a marked cathodic component is applied in the first stage and an off-time of 10 to 60 seconds is inserted between direct current and alternating current treatment, a longer time and/or higher voltage being employed in the second stage than in the first stage.
IPC 1-7
IPC 8 full level
C25D 11/22 (2006.01)
CPC (source: EP)
C25D 11/22 (2013.01)
Citation (search report)
- [A] GB 2053972 A 19810211 - EMPRESA NACIONAL ALUMINIO
- [XP] EP 0279146 A1 19880824 - ALUSUISSE [CH]
- [X] EP 0239944 A1 19871007 - FUJISASH CO [JP]
Designated contracting state (EPC)
AT CH DE LI NL
DOCDB simple family (publication)
EP 0320952 A2 19890621; EP 0320952 A3 19900131; EP 0320952 B1 19930512; AT E89338 T1 19930515; DE 3743113 A1 19890629; DE 3743113 C2 19920507; DE 3880990 D1 19930617
DOCDB simple family (application)
EP 88121038 A 19881215; AT 88121038 T 19881215; DE 3743113 A 19871218; DE 3880990 T 19881215