EP 1017878 A1 20000712 - CHROMATE TREATMENT OR POSTPASSIVATION WITH STABILISED SOLUTIONS BASED ON Cr (III)/(VI)
Title (en)
CHROMATE TREATMENT OR POSTPASSIVATION WITH STABILISED SOLUTIONS BASED ON Cr (III)/(VI)
Title (de)
CHROMATIERUNG ODER NACHPASSIVIERUNG MIT STABILISIERTEN Cr(III)/Cr(VI)-HALTIGEN LÖSUNGEN
Title (fr)
CHROMATATION OU POSTPASSIVATION AVEC DES SOLUTIONS STABILISEES A BASE DE Cr(III)/Cr(VI)
Publication
Application
Priority
- DE 19740248 A 19970912
- EP 9805630 W 19980905
Abstract (en)
[origin: DE19740248A1] An aqueous chromating or post-passivating solution, which contains trivalent and hexavalent chromium and acetate ions, has a pH of 3.9-5.0 and contains 0.1-10 g/l acetate ions. An aqueous chromating or post-passivating solution has a pH of 3.9-5.0, a total chromium content of 0.1-10 g/l, a Cr(III):Cr(VI) ratio of 1:1-4 and an acetate ion content of 0.1-10 g/l. Independent claims are also included for (i) an aqueous concentrate which, on dilution by a factor of 50-2000 with water, gives the above solution; and (ii) a chromating or post-passivating treatment, in which the metal surfaces are contacted for 1-120 secs. with the above solution at 20-60 deg C. Preferred Feature: The solution additionally contains one or more of up to 0.5 g/l fluoride ions, up to 1.0 g/l zirconium and/or titanium compounds, up to 0.5 g/l phosphate ions, up to 0.5 g/l nickel(II) ions and up to 0.5 g/l iron(III) ions.
IPC 1-7
IPC 8 full level
C23C 22/30 (2006.01); C23C 22/33 (2006.01); C23C 22/37 (2006.01); C23C 22/38 (2006.01); C23C 22/83 (2006.01)
CPC (source: EP)
C23C 22/30 (2013.01); C23C 22/33 (2013.01); C23C 22/37 (2013.01); C23C 22/38 (2013.01); C23C 22/83 (2013.01)
Citation (search report)
See references of WO 9914398A1
Designated contracting state (EPC)
BE DE ES FR GB IT SE
DOCDB simple family (publication)
DE 19740248 A1 19990318; CA 2303101 A1 19990325; EP 1017878 A1 20000712; WO 9914398 A1 19990325; ZA 988356 B 19990312
DOCDB simple family (application)
DE 19740248 A 19970912; CA 2303101 A 19980905; EP 9805630 W 19980905; EP 98951353 A 19980905; ZA 988356 A 19980911