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. 28, 2003
Filed:
Jun. 13, 2002
William E. Slack, Moundsville, WV (US);
Hersel T. Kemp, II, New Martinsville, WV (US);
William E. Miller, St. Clairsville, OH (US);
Bayer Corporation, Pittsburgh, PA (US);
Abstract
This invention relates to a continuous process for the production of allophanate modified diphenylmethane diisocyanates having an NCO group content of 19 to 32% and an urethane content of less than 2 area % by GPC analysis. The process comprises (1) continuously reacting (a) diphenylmethane diisocyanate and (b) an alcohol, in the presence of (c) at least 25 ppm of an allophante catalyst, based on the combined weight of the diphenylmethane diisocyanate and the alcohol, in a reactor in an oxygen-free environment; (2) continuously treating the product exiting the reactor with a catalyst stopper at the reaction temperature; and (3) cooling the resultant product.