EP 0414296 B1 19930630 - PROCESS FOR OBTAINING PHOSPHATE COATINGS ON METAL SURFACES
Title (en)
PROCESS FOR OBTAINING PHOSPHATE COATINGS ON METAL SURFACES
Publication
Application
Priority
DE 3927614 A 19890822
Abstract (en)
[origin: EP0414296A1] In a process for phosphating iron and steel surfaces according to the low-zinc technology, a nitrite-free aqueous acidic phosphating solution of 30 to 65 DEG C is used which contains 0.4 to 1.7 g/l of Zn 7 to 25 g/l of P2O5 2 to 30 g/l of NO3 and in which the weight ratio of free P2O5 to total P2O5 is adjusted to a value in the range from 0.04 to 0.20. H2O2 or alkali metal perborate is added to the phosphating solution in an amount such that - in the incorporated state - its maximum peroxide concentration is 17 mg/l, preferably 8 mg/l (calculated as H2O2), or its maximum Fe(II) concentration is 60 mg/l, preferably 30 mg/l (calculated as Fe). It is particularly advantageous to control the addition of H2O2 and/or alkali metal perborate according to the electrochemical potential determined with a redox electrode. The phosphating solution may additionally contain Mn, Ni, Co, Mg and/or Ca or fluoroborate, fluorosilicate and/or fluoride. The process can be used in particular for the preparation of metal surfaces for coating. <IMAGE>
IPC 1-7
IPC 8 full level
C23C 22/13 (2006.01); C23C 22/16 (2006.01); C23C 22/18 (2006.01); C23C 22/36 (2006.01); C23C 22/77 (2006.01)
CPC (source: EP)
C23C 22/16 (2013.01); C23C 22/184 (2013.01); C23C 22/362 (2013.01); C23C 22/77 (2013.01)
Citation (examination)
- W. Rausch et al. "Die Phosphertierung von Metallen", 1974 Eugen Leuze Verlag, Saulgau/Württ, Deutschland
- W. Rausch "Fortschritte auf dem Gebiet der chemischen Oberflächenbehandlung von Metallen" Interfinish 68, Tagungsberichtsband, Hannover 5.-9. Mai 1968, 162-167.
Designated contracting state (EPC)
AT BE DE ES FR GB IT NL SE
DOCDB simple family (publication)
EP 0414296 A1 19910227; EP 0414296 B1 19930630; AT E91159 T1 19930715; BR 9004117 A 19910903; CA 2022728 A1 19910223; CA 2022728 C 20000201; DD 299662 A5 19920430; DE 3927614 A1 19910228; DE 59001884 D1 19930805; ES 2042199 T3 19931201; JP 2992619 B2 19991220; JP H0387374 A 19910412; PL 286572 A1 19920210; PT 95053 A 19910418; PT 95053 B 19970430; ZA 906673 B 19920429
DOCDB simple family (application)
EP 90202104 A 19900802; AT 90202104 T 19900802; BR 9004117 A 19900821; CA 2022728 A 19900806; DD 34356090 A 19900821; DE 3927614 A 19890822; DE 59001884 T 19900802; ES 90202104 T 19900802; JP 22094090 A 19900822; PL 28657290 A 19900821; PT 9505390 A 19900821; ZA 906673 A 19900822