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. 11, 1991
Filed:
May. 26, 1987
Applicant:
Inventors:
Mosum E Tsui, Silver Spring, MD (US);
Martin B Sherwin, Potomac, MD (US);
Assignee:
W. R. Grace & Co.-Conn., New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ; C07C / ;
U.S. Cl.
CPC ...
562512 ; 562592 ; 562594 ;
Abstract
A process for forming thioglycolic acid by contacting in a reaction zone at elevated pressure of at least 250 psig a mixture of monochloroacetic acid and dichloroacetic acid with a molar excess of an alkali metal hydrosulfide to form the alkali metal salt of thioglycolic acid, acidifying said salt and removing the free thioglycolic acid. A preferred process further requires separating any formed thiodiglycolic acid from the resultant liquid phase materials and recycling said acid to the reaction zone.