POLYASPARTIC ACID DERIVATIVE SOLUBLE OR DISPERSIBLE IN WATER, ITS PRODUCTION AND ITS USE

PROBLEM TO BE SOLVED: To obtain a hair-treatment composition, etc., having high hair-setting performance and easily rinsable from the hair by using a polyaspartic acid derivative produce by reacting a polyaspartic acid with a specific amine mixture. SOLUTION: A water-soluble and/or water-dispersible polyaspartic acid derivative or its carboxylic acid salt and polycarboxylic acid salt or quaternarized product based on the unit of the formula (x+y1 +y2 +z=100; (x) is 30-100; (y1 ) is 0-70: (y2 ) is 0-50; (z) is 0-30; A is a primary or secondary non-aromatic amine; B is an amine having t-amino group; C is a group derived from the amine A by the elimination of the amine hydrogen) are used for cosmetic use, especially for the treatment of hair. The compounds of the formula wherein (x) is 30-99.9, (y1 ) is 0.1-50 and (y2 ) is 5-50 are new compounds. The compound of the formula can be produced by reacting a polyaspartic acid or a polysuccinimide with the amine A and the amine B.