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. 04, 2011
Filed:
Jun. 07, 2006
Applicants:
Joachim Zechlin, Neuss, DE;
Bernd Pennemann, Bergisch-Gladbach, DE;
Friedhelm Steffens, Leverkusen, DE;
Wenbin Ji, League, TX (US);
Inventors:
Joachim Zechlin, Neuss, DE;
Bernd Pennemann, Bergisch-Gladbach, DE;
Friedhelm Steffens, Leverkusen, DE;
Wenbin Ji, League, TX (US);
Assignees:
Bayer MaterialScience LLC, Pittsburgh, PA (US);
Bayer MaterialScience AG, Leverkusen, DE;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C 39/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
The invention relates to a process for the production of toluene diisocyanate, in which the crude toluenediamine obtained from the hydrogenation is purified and then phosgenated. The purification step reduces the total amount of cyclic ketones to less than 0.1% by weight, based on 100% by weight of the toluenediamine.