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:
Mar. 20, 1984
Filed:
Dec. 20, 1982
Akira Miyamoto, Kanagawa, JP;
Senzo Shimizu, Kanagawa, JP;
Masahiro Harada, Kanagawa, JP;
Tamotu Ajiro, Kanagawa, JP;
Hideki Hara, Kanagawa, JP;
Mitsubishi Gas Chemical Co., Ltd., Tokyo, JP;
Abstract
A process for preparing a polyamide is provided. The polyamide is prepared by causing a dicarboxylic acid and a diamine to polycondensate directly under an atmosphere of an inert gas at atmospheric pressure. The polycondensation reaction is mainly carried out in two diamine component-adding steps, one step comprising adding part of the diamine to the molten dicarboxylic acid until the molar ratio of the diamine to the dicarboxylic acid is brought to within the range of from 0.900 to 0.990 while raising continuously the temperature of the reaction mixture to a temperature not exceeding about 5.degree. C. above the melting point of the object polyamide and the other step comprising adding the remainder of the diamine to the reaction mixture maintained at a temperature higher than about 10.degree. C., but not exceeding about 35.degree. C. above the melting point of the object polyamide until the overall molar ratio of the diamine to the dicarboxylic acid is brought to within the range of from 0.995 to 1.005.