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:
Apr. 05, 1994
Filed:
Dec. 30, 1992
Applicant:
Inventor:
Wolfgang Friederichs, Cologne, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528 67 ; 25218221 ; 25218222 ; 560336 ; 560352 ;
Abstract
Polyisocyanate mixtures are isolated in pure or more concentrated form from isomeric mixtures by liquid-liquid extraction using a two-phase system. The two phases are 1) a non-polar solvent phase and 2) a polar solution in which a hydrogen halide is present. In a preferred embodiment, the extraction is carried out in a countercurrent extractor.