Patent · US Expired

Production of polysuccinimide

US5491213A · kind A · utility

5Cited by
8References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 28, 1994
Grant dateFeb 13, 1996
Priority date
Expiry dateJan 28, 2014

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08F8/44
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

Polysuccinimide is prepared by reacting an unsaturated C.sub.2 dicarboxylic acid or anhydride thereof, e.g., maleic acid, fumaric acid, and maleic anhydride, with a particulate ammonium salt that is thermally decomposable to liberate ammonia. The reaction is carried out at a temperature which is above the thermal decomposition temperature of the ammonium salt and for a time period which is sufficient for the acid or anhydride to react with the ammonia liberated from the ammonium salt and for polymerization to occur. The present method avoids the prior art problems of controlling ammonia losses and water removal. The product polysuccinimide can be readily hydrolyzed to polyaspartic acid or a salt thereof, if desired.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.