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:
Nov. 29, 2016
Filed:
Nov. 15, 2011
Michael Bock, Ruppertsberg, DE;
Johannes Jacobs, Antwerpen, BE;
Kai Thiele, Antwerpen, BE;
Anne-kathrin Merten, Lauchhammer, DE;
Michael Bock, Ruppertsberg, DE;
Johannes Jacobs, Antwerpen, BE;
Kai Thiele, Antwerpen, BE;
Anne-Kathrin Merten, Lauchhammer, DE;
BASF SE, Ludwigshafen, DE;
Abstract
The invention relates to a method for purifying mixtures comprising 4,4'-methylenediphenyl diisocyanate, which comprises purifying by distillation a mixture I comprising 4,4′-methylenediphenyl diisocyanate having a hydrolyzable chlorine content as specified in ASTM D4663-10 of greater than 100 ppm by means of a column K, wherein the gaseous stream comprising the mixture I is brought into contact in the column Kwith at least one liquid compound A which has the same or higher boiling point than 4,4′-methylenediphenyl diisocyanate and which has a hydrolyzable chlorine content as specified in ASTM D4663-10 of a maximum of 100 ppm, and wherein the gaseous stream O obtained at the top of the column comprises 4,4′-methylenediphenyl diisocyanate has a hydrolyzable chlorine content as specified in ASTM D4663-10 of a maximum of 100 ppm.