Mitsui Chemicals, Inc.

Katsuhiko Machida

Toshio Katoh

Shinji Ogawa

Yoshihiro Irizato

Makoto Sukegawa

Susumu Fukawa

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.

Growing community of inventors

Chiba, Japan

Katsuhiko Machida