Title:
PRODUCTION AND RECOVERY OF POLYASPARTIC ACID
Document Type and Number:
Japanese Patent JP3434608
Kind Code:
B2
Abstract:
PURPOSE: To produce and recover a polyaspartic acid having high purity in an easy manner at a low cost in a short time by forming a polyaspartic acid salt from a polysuccinimide and subsequently reacting the salt with an acid to neutralize it.
CONSTITUTION: This method comprises the following processes: (A) a polyaspartic acid salt is formed by reacting a polysuccinimide having a degree of polymerization of 10-2000 with a base to convert the imide ring to the salt of an amic acid; (B) a polyaspartic acid and a salt are formed by reacting the polyaspartic acid salt with an acid to convert the salt of the amic acid to an amide; and (C) the polyaspartic acid is separated from the salt and recovered by adding a mixed solvent of water with an organic: solvent to the mixture of the polyaspartic acid with the salt and making the salt dissolve in the mixed solvent and precipitate the polyaspartic acid or by making the polyaspartic acid dissolve in the mixed solvent and precipitate the salt by controlling the balance of hydrophilic nature/hydrophobic nature of the mixed solvent. The base used in the process A is preferably a basic amino acid or its salt.
Inventors:
Toshio Kato
Hiroaki Tamaya
Masanobu Ajioka
Akihiro Yamaguchi
Hiroaki Tamaya
Masanobu Ajioka
Akihiro Yamaguchi
Application Number:
JP3556595A
Publication Date:
August 11, 2003
Filing Date:
February 23, 1995
Export Citation:
Assignee:
Mitsui Chemicals, Inc.
International Classes:
C08G69/10; C08G73/06; (IPC1-7): C08G69/10; C08G73/06
Domestic Patent References:
| JP6298930A | ||||
| JP859821A | ||||
| JP4885687A |
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