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:
Jun. 24, 1980
Filed:
May. 10, 1977
James H Dube, Mobile, AL (US);
Ralph Miller, Pleasantville, NY (US);
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
A liquid-liquid extraction method for recovering O,O-di(lower)alkyldithiophosphoric acid of increased purity from a crude mixture in which it is contained comprises intimately contacting said mixture with an acidic aqueous solution to form two liquid phases whereby the concentration of the thiophosphoric acid in the aqueous phase is increased; separating the two phases; contacting the aqueous phase with a stable, water-immiscible, volatile, organic solvent to form two liquid phases whereby the concentration of the thiophosphoric acid in the organic solvent is increased; separating the two phases; and vaporizing the organic solvent to recover high purity O,O-di(lower)alkyl dithiophosphoric acid.