Title (en)

PHOSPHATING METHOD

Publication

EP 0478028 A3 19920415 (DE)

Application

EP 91202119 A 19910820

Priority

DE 4029956 A 19900921

Abstract (en)

[origin: EP0478028A2] In the phosphating of metal surfaces composed at least partially of aluminium by means of zinc-, phosphate- and fluoride-containing phosphating solutions, titanium, which is absorbed by the phosphating solution and interferes with the layer formation, is precipitated by adding SiO-containing compounds and the required concentration of free fluoride is reestablished after the precipitate has been removed. <??>Particularly suitable SiO-containing compounds are alkali-metal metasilicate, orthosilicate and/or disilicate, preferably in an amount of 0.05 to 1 g/l of phosphating solution, or silicon dioxide, preferably in an amount of 0.5 to 10 g/l of phosphating solution (calculated in all cases as Si).

IPC 1-7

C23C 22/86; C23C 22/36

IPC 8 full level

C23C 22/36 (2006.01); C23C 22/86 (2006.01)

CPC (source: EP US)

C23C 22/362 (2013.01 - EP US); C23C 22/86 (2013.01 - EP US)

Citation (search report)

• [A] DE 1521677 B1 19700430 - AMCHEM PROD
• [A] US 3519494 A 19700707 - ENGESSER RUDOLF, et al
• [A] EP 0131298 A2 19850116 - AMCHEM PROD [US]
• [A] FR 2313461 A1 19761231 - PARKER STE CONTINENTALE [FR]
• [A] US 2909455 A 19591020 - NEWHARD JR NELSON J, et al

Designated contracting state (EPC)

BE DE ES FR GB IT

DOCDB simple family (publication)

EP 0478028 A2 19920401; EP 0478028 A3 19920415; EP 0478028 B1 19950301; DE 4029956 A1 19920326; DE 59104766 D1 19950406; JP H04246178 A 19920902; US 5135583 A 19920804

DOCDB simple family (application)

EP 91202119 A 19910820; DE 4029956 A 19900921; DE 59104766 T 19910820; JP 25309291 A 19910904; US 74919191 A 19910823