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.

Date of Patent:
Apr. 17, 1990

Filed:

Jan. 13, 1989
Applicant:
Inventors:

Gerard Collas, Caluire, FR;

Georges Gros, Bourg La Reine, FR;

Ferenc Sagi, Lyons, FR;

Assignee:

Rhone-Poulenc Chimie, Courbevoie, FR;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
560352 ; 560347 ;
Abstract

Toluene diisocyanate (TDI) is separated and recovered from the residues of the production thereof, e.g., from the tars of phosgenation of an aromatic diamine, by extracting such residues with an extractant which comprises an inert gas, e.g., CO.sub.2, in either the liquid or supercritical state, optionally in the presence of a coextractant diluent, for example an ester, aromatic hydrocarbon or chlorinated aromatic hydrocarbon, or chlorinated aliphatic hydrocarbon.


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