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:
Feb. 26, 1991
Filed:
Jan. 27, 1987
Applicant:
Inventors:
John L Nafziger, Lake Jackson, TX (US);
Mark J Hazelrigg, Lake Jackson, TX (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
560352 ;
Abstract
This invention is a process for removing volatile impurities from a crude isocyanate compound which is prepared in the phosgenation of a primary amine, comprising heating said crude isocyanate compound to a temperature to volatilize said volatile impurities in the presence of an acidic material containing a plurality of strong acid groups. The process permits faster, more complete removal of hydrolyzable chloride impurities than conventional processes.