Monsanto Company

Other

Mark E Jason

Dennis J Kalota

Liou-Liang Horng

Edward J Griffith

Chung Y Shen

Gregory C Alexander

There is disclosed a process for microencapsulation of materials by means of complex coacervation employeing gelatin and polyaspartic acid. Material to be encapsulated is emulsified in an aqueous solution of gelatin. Polyaspartic acid or a salt thereof is employed to provide a counter ion to the gelatin which, when induced to precipitate from solution by cooling and/or pH change forms a wall around the material. The wall is hardened by crosslinking to form a stable microcapsule containing the material.

Microencapsulation process by coacervation

There is disclosed a process for preparing polyaspartic acid by thermal condensation of L-aspartic acid in a novel catalyst which shortens the reaction time and increases the molecular weight of the polymer. The novel catalyst is a catalytically effective methylenephosphonic acid. Typical catalysts are 1-hydroxyethylidene-1,1-diphosphonic acid and aminotris(methylenephosphonic acid). The methylenephosphonic acid is blended with the amino acid in a molar ratio of amino acid to catalyst in the range of from about 1:1 to 40:1.

Preparation of anhydropolyamino acids

There is disclosed an improved process for preparing 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylic acid and 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylic acid wherein the unreacted starting acids are recovered in more desirable crystal habit. The acids are precipitated in salt form by lowering the pH of the reaction product to a range of from 4 to below 6 stepwise. The pH is lowered to above 6 in the first step and then relatively rapidly reduced to the desired level in the second step.

Chemical process

There is disclosed herein improved processes for the preparation of mixtures of alkali metal salts of 1-hydroxy-3-oxa-1,2,4,5-pentane tetracarboxylate and alkali metal salts of 3,6-dioxa-1,2,4,5,7,8-octane hexacarboxylate wherein by-product calcium carbonate produced by the process of making such mixtures is employed in a recycle pattern to prepare additional amounts of mixtures of said compounds.

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Chesterfield, MO, United States of America

Mark E Jason