Title (en)

PROCESS FOR PREPARING AN ACIDIC PASSIVATING BATH FOR ZINC, ZINC ALLOYS AN CADMIUM SURFACES, CONTAINING CHROMIUM III AND FLUORIDE

Publication

EP 0337411 A3 19900509 (DE)

Application

EP 89106447 A 19890411

Priority

DE 3812076 A 19880412

Abstract (en)

[origin: EP0337411A2] An acidic chromium(III)-containing and fluoride-containing passivating bath for surfaces of zinc, zinc alloys and cadmium is prepared by mixing 20-200 g/l of a soluble chromium(III) compound, 20 to 600 g/l of a soluble nitrate, 5 to 100 g/l of a fluoride and of a sulphate, phosphate, chloride, bromide, fluoride or iodide anion, adding hydrochloric or nitric acid to a pH of 1.8 to 2.2 and heating to above 60 DEG C or adding a catalyst, the amount of nitrate being greater than the chromium(III) concentration. It contains one or more complex(es) of the formula (1): <IMAGE> (x = 1 to 3, n = valency of A and A = nitrate, sulphate, phosphate, chloride, bromide, fluoride or iodide).

IPC 1-7

C23C 22/34

IPC 8 full level

C23C 22/34 (2006.01)

CPC (source: EP)

C23C 22/34 (2013.01); C23C 2222/10 (2013.01)

Citation (search report)

• [X] US 4705576 A 19871110 - KLOS KLAUS-PETER [DE], et al
• [YD] GB 2097024 A 19821027 - HOOKER CHEMICALS PLASTICS CORP
• [A] DE 2166737 A1 19750605 - DU PONT
• [A] US 4578122 A 19860325 - CROTTY DAVID E [US]
• [A] GB 2059445 A 19810423 - RICHARDSON CHEMICAL CO
• [AD] US 4263059 A 19810421 - GUHDE DONALD J, et al
• [AD] US 4171231 A 19791016 - BISHOP CRAIG V [US], et al

Designated contracting state (EPC)

AT BE CH DE ES FR GB GR IT LI LU NL SE

DOCDB simple family (publication)

EP 0337411 A2 19891018; EP 0337411 A3 19900509; EP 0337411 B1 19931124; AT E97700 T1 19931215; DD 280557 A5 19900711; DE 3812076 A1 19891026; DE 3812076 C2 19900913; DE 58906227 D1 19940105; YU 71689 A 19901231

DOCDB simple family (application)

EP 89106447 A 19890411; AT 89106447 T 19890411; DD 32744989 A 19890410; DE 3812076 A 19880412; DE 58906227 T 19890411; YU 71689 A 19890410