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. 02, 2003
Filed:
Jun. 18, 2001
Katsuhiko Machida, Chiba, JP;
Susumu Fukawa, Kanagawa, JP;
Shinji Ogawa, Kanagawa, JP;
Toshio Katoh, Saitama, JP;
Makoto Sukegawa, Kanagawa, JP;
Yoshihiro Irizato, Chiba, JP;
Mitsui Chemicals, Inc., Tokyo, JP;
Abstract
A production process of high molecular weight polysuccinimide having a weight average molecular weight of 40,000 or higher is disclosed, which comprises the following steps: 1) mixing and heating aspartic acid and an acidic catalyst to produce a liquid, low molecular weight polymer mixture, 2) separating the acidic catalyst to appropriate extent from the liquid, low molecular weight polymer mixture, thereby directly changing a polymer-containing phase from a liquid phase into a solid phase to produce a solid, low molecular weight polymer mixture, and 3) conducting solid-state polymerization on the thus-obtained solid, low molecular weight polymer mixture. This process can be practiced in a simple apparatus, and is free of problems such as formation of a highly viscous phase, excessive formation of foam, and formation of a reaction mixture into coherent mass.