Global Patent Index - EP 0279146 B1

EP 0279146 B1 19920325 - PROCESS FOR ELECTROLYTICALLY COLOURING AN ANODIC OXIDE LAYER ON ALUMINIUM OR ALUMINIUM ALLOYS

Title (en)

PROCESS FOR ELECTROLYTICALLY COLOURING AN ANODIC OXIDE LAYER ON ALUMINIUM OR ALUMINIUM ALLOYS

Publication

EP 0279146 B1 19920325 (DE)

Application

EP 87810782 A 19871224

Priority

CH 14587 A 19870116

Abstract (en)

[origin: US4798656A] In processes for electrolytically dyeing anodic oxide layers on aluminum or aluminum alloys with direct or alternating current in electrolytes containing metal salts, high requirements are imposed on the uniformity of the dyeing and on the dyeing rate. The improvement of the uniformity of the dyeing and an increased dyeing rate can be achieved by pretreating the oxide layer by means of asymmetric alternating current before it is dyed. Such a process is preferably used in combination with an Sn-containing electrolyte.

IPC 1-7

C25D 11/22

IPC 8 full level

C25D 11/22 (2006.01)

CPC (source: EP US)

C25D 11/22 (2013.01 - EP US); Y10S 204/08 (2013.01 - EP US); Y10S 204/09 (2013.01 - EP US)

Citation (examination)

EP 0239944 A1 19871007 - FUJISASH CO [JP]

Designated contracting state (EPC)

BE CH DE FR GB IT LI NL

DOCDB simple family (publication)

EP 0279146 A1 19880824; EP 0279146 B1 19920325; DE 3777806 D1 19920430; US 4798656 A 19890117

DOCDB simple family (application)

EP 87810782 A 19871224; DE 3777806 T 19871224; US 14294588 A 19880112