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:
Sep. 19, 2006
Filed:
Oct. 16, 2003
Marcus Paul Grün, Düsseldorf, DE;
Bill Brady, Jr., Düsseldorf, DE;
Berthold Keggenhoff, Krefeld, DE;
Kai Verkerk, Hilden, DE;
Hans-peter Schal, Dormagen, DE;
Marcus Paul Grün, Düsseldorf, DE;
Bill Brady, Jr., Düsseldorf, DE;
Berthold Keggenhoff, Krefeld, DE;
Kai Verkerk, Hilden, DE;
Hans-Peter Schal, Dormagen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
Toluene diisocyanate is recovered from a crude distillation feed containing less than 2% by weight of phosgene by (a) fractionating the crude distillation feed containing less than 2% by weight of phosgene to remove the solvent and optionally the reaction residues to produce a crude toluene diisocyanate feed containing less than 20% by weight of solvent and (b) separating the crude toluene diisocyanate feed containing less than 20% by weight of solvent in a divided-wall distillation column into four product fractions P1–P4. P1 is a vapor phase low-boiler and solvent-enriched gas stream, P2 is a low-boiler and solvent-enriched product, P3 is a high boiler-enriched bottoms product containing toluene diisocyanate and P4 is a toluene diisocyanate product stream lean in low-boilers, high-boilers and reaction residues.