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. 26, 1994
Filed:
Apr. 29, 1992
Takao Ikariya, Tokyo, JP;
Masanori Itagaki, Tokyo, JP;
Masatsugu Mizuguchi, Tokyo, JP;
Makoto Miyazawa, Tokyo, JP;
Sachiko Yamamoto, Tokyo, JP;
NKK Corporation, Tokyo, JP;
Abstract
A method for manufacturing a purified aromatic urethane. Aromatic urethanes are synthesized from a N,N'-disubstituted urea and an organic hydroxyl compound in a reaction medium. The organic hydroxyl compound and the primary aromatic amine side product which are present in the reaction mixture is distilled off and removed from the reaction mixture leaving a distillation bottom. The N,N'-disubstituted urea is separated and removed from the distillation bottom by solvent extraction of the aromatic urethane, and the aromatic urethane in the extract phase obtained in said solvent extraction is separated and purified.