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:
Aug. 24, 1993
Filed:
Aug. 05, 1991
Richard A Markle, Columbus, OH (US);
Battelle Memorial Institute, Columbus, OH (US);
Abstract
Polyarylimidazolidines with a degree of polymerization of about one to twenty and having phenolic hydroxyl end groups and a novel three-step process for their preparation are described. In the first step of the process, an excess of hydrogen cyanide is reactive with an aryl diisocyanate. The excess hydrogen cyanide promotes polymerization and avoids the reaction of the imino hydrogen on the heterocyclic range with the diisocyanate to form cross linkage and associated gel formation. In the second step, a stoichiometric amount of diisocyanate is added to react with the excess hydrogen cyanide and one hydroxyl of a phenolic dihydroxyl end capping group. In the final third step, the dihydroxyl end capping group is added and the remaining diisocyanate reacts with one of the two phenolic hydroxyls on the end capping group.