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:
Apr. 16, 1991
Filed:
Nov. 07, 1989
Bayer Aktiengesellschaft, , DE;
Abstract
This invention relates to a process for preparing polyurethanes having liquid crystal properties comprising reacting, in proportions corresponding to an NCO/OH equivalent ratio of from about 0.9:1 to 1.1:1, an organic polyhydroxyl compound with an organic diisocyanate having at least two phenylene groups and at least one carboxylic ester group. The organic diisocyanate comprises an aliphatic diisocyanate wherein at least one of the carboxylic ester groups connects an aliphatic group to a phenylene group or an aromatic diisocyanate wherein at least one of the carboxylic acid groups connects two phenylene groups. This invention further relates to preferred diisocyanates used in the process according to this invention.