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:
Dec. 24, 1996
Filed:
Apr. 05, 1995
Masahiro Harada, Hiratsuka, JP;
Yasuo Inaba, Hiratsuka, JP;
Mitsubishi Gas Chemical Co., Inc., Tokyo, JP;
Abstract
A method for producing a copolyamide, which comprises (1) heating either one dicarboxylic acid selected from the group consisting of adipic acid and a mixture containing 40 mol % or more of adipic acid to a temperature higher than the melting point of adipic acid but lower than a temperature lower by 30.degree. C. than the melting point of the resulting copolyamide, (2) dropping a diamine comprising paraxylylene diamine and metaxylylene diamine into the heated dicarboxylic acid before a conversion of the dicarboxylic acid reaches 90 mol %, (3) stopping dropping of the diamine before the conversion of the dicarboxylic acid reaches 90 mol %, and dropping metaxylylene diamine or a diamine mixture of metaxylylene diamine and paraxylylene diamine in place of the diamine until a molar ratio of the total of the diamines to the total of the dicarboxylic acids becomes 0.97 to 1.03, and (4) heating a reaction system to a temperature higher than a temperature lower by 30.degree. C. than the melting point of the finally formed copolyamide before the conversion of the dicarboxylic acid reaches 95 mol %, and elevating the temperature of the reaction system to a temperature higher than the melting point of the finally formed copolyamide upon termination of dropping the diamine.