EP 1141449 A2 20011010 - METHOD FOR DARKENING A SUPERFICIAL LAYER WHICH CONTAINS ZINC AND WHICH IS OF A MATERIAL PIECE
Title (en)
METHOD FOR DARKENING A SUPERFICIAL LAYER WHICH CONTAINS ZINC AND WHICH IS OF A MATERIAL PIECE
Title (de)
VERFAHREN ZUM ABDUNKELN EINER OBERFLÄCHENSCHICHT EINES MATERIALSTÜCKES, DIE ZINK ENTHÄLT
Title (fr)
PROCEDE POUR RENDRE PLUS SOMBRE UNE COUCHE SUPERFICIELLE, CONTENANT DU ZINC, D'UN MORCEAU DE MATIERE
Publication
Application
Priority
- DE 19858795 A 19981218
- EP 9910036 W 19991217
Abstract (en)
[origin: US2005126921A1] The invention relates to a method for darkening a superficial layer of a workpiece which contains zinc by anodic oxidation. The workpiece is oxidized in a soaking bath containing an aqueous solution comprised of a hydroxide and of a nitrate. The anodic oxidation may be carried out in an aqueous solution containing NH.sub.4 NO.sub.3 or NaNO.sub.3, and having a pH value ranging from 8 to 14, at a dipping bath temperature (T) ranging from 15 to 45.degree. C., and with a current density (i) ranging from 3.times.10.sup.-4 to 0.5 A/cm.sup.2. The workpiece is placed in the soaking bath at the beginning of the anodic oxidation after the voltage has already been applied.
IPC 1-7
IPC 8 full level
C23C 22/60 (2006.01); C25D 11/34 (2006.01)
CPC (source: EP US)
C23C 22/60 (2013.01 - EP US); C25D 11/34 (2013.01 - EP US)
Citation (search report)
See references of WO 0037717A2
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
US 2005126921 A1 20050616; US 7311787 B2 20071225; AT E239109 T1 20030515; DE 19858795 A1 20000621; DE 19858795 C2 20010315; DE 59905366 D1 20030605; DK 1141449 T3 20030825; EP 1141449 A2 20011010; EP 1141449 B1 20030502; ES 2197702 T3 20040101; JP 2002533573 A 20021008; PT 1141449 E 20030930; US 6758956 B1 20040706; WO 0037717 A2 20000629; WO 0037717 A3 20001019
DOCDB simple family (application)
US 85287004 A 20040525; AT 99963569 T 19991217; DE 19858795 A 19981218; DE 59905366 T 19991217; DK 99963569 T 19991217; EP 9910036 W 19991217; EP 99963569 A 19991217; ES 99963569 T 19991217; JP 2000589764 A 19991217; PT 99963569 T 19991217; US 86828301 A 20010615