The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 15, 2002
Filed:
Aug. 03, 2000
Henkel Kommanditgesellschaft auf Aktien, Duesseldorf, DE;
Abstract
A process for treating phosphatising bath overflow and/or wash water after phosphatising, phosphatising being performed using an acid, aqueous phosphatising solution which contains from 3 to 50 g/l of phosphate ions, calculated as PO , from 0.2 to 3 g/l of zinc ions, optionally further metal ions and accelerator, characterised in that the accelerator is an organic molecule or molecular ion having a molecular weight of at least 80 g/mol, and that the phosphatising bath overflow and/or the wash water is subjected to ultrafiltration. The permeate from ultrafiltration is preferably separated further by means of nanofiltration or reverse osmosis. The permeate from the second separation may be recycled as wash water; the retentate may be recycled to the phosphatising bath.