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US 5,315,010 AGranted
Polyaspartic acid manufacture
AssigneeDonlar Corporation
InventorsLarry P. Koskan, Kim C. Low, Abdul R. Y. Meah, Anne M. Atencio
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Abstract
Polyaspartic acid having a weight average molecular weight of 1000 to 5000 is produced by hydrolysis of anhydropolyaspartic acid that has been produced by condensation polymerization of L-aspartic acid. Conversion in excess of 80 percent is achievable utilizing "temperature vs. time" profiles.
Claims2
A method of producing polysuccinimide, comprising the steps
- (a) introducing powdered L-aspartic acid onto an indirectly heated plate drier;
- (b) heating the introduced powdered L-aspartic acid to a temperature of at least 370.degree. F. to initiate a condensation reaction;
- (c) thereafter elevating the temperature of said L-aspartic acid to at least 440.degree. F.;
- and
- (d) maintaining the temperature at at least the 440.degree. F. until at least 80% conversion of L-aspartic acid to polysuccinimide has been achieved.
2 more elements
Dependencies are inferred from the claim text.