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. 24, 1989
Filed:
Aug. 31, 1988
Applicant:
Inventors:
Lao-Jer Chen, Houston, TX (US);
Steven B Lowenkron, Houston, TX (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
560352 ;
Abstract
Disclosed is an extraction process wherein a crude polyisocyanate is separated into a purified fraction and residual fraction wherein the purified fraction is characterized by greatly improved color over the crude material but with little or no difference in viscosity. The residual fraction remains perfectly useful for those applications where color is not a critical requirement. Significantly, the disclosed purification is achieved with literally a 100 percent material balance. No loss in polyisocyanate is encountered.