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:
Dec. 15, 1998
Filed:
Aug. 01, 1996
Klaus Biskup, Leverkusen, DE;
Berthold Keggenhoff, Krefeld, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
Toluylene diisocyanate is produced by nitration of toluene toy yield dinitrotoluene, hydrogenation of the dinitrotoluene, optionally in the presence of a solvent or diluent, to yield a crude solution of toluylene diamine and reaction water, processing the crude solution of toluylene diamine and water to yield an intermediate mixture of toluylene diamine and water wherein the processing is interrupted to result in a water content of about 1-40% by weight, preferably about 2-10% by weight of the intermediate mixture, transporting this intermediate mixture from a first production facility to a second production facility, whereat the intermediate mixture of TDA and water is completed to yield dry toluylene diamine of commercial quality, and followed by phosgenation of the toluylene diamine to give toluylene diisocyanate. It is optional to additionally process the dry toluylene diamine prior to phosgenation. The invention also relates to intermediate mixtures of toluylene diamine and water which have a solidification point of at most 95.degree. C., and the use of these intermediate mixtures for producing toluylene diisocyanate. It is preferable that the use of these intermediate mixtures to produce toluylene diisocyanate is performed at a site (or location) which is different from the site of production of the intermediate mixtures of toluylene diamine and water.