Process for the preparation of polyaspartic acid derivatives

Abstract

Process for the preparation of polyaspartic acid derivatives of the general formula (I) 1 wherein h, i, j, and k represent the molar fraction of each repeating unit and are decimal numbers between ≧0 and <1 where the sum of h, i, j and k is 1 and at least one of the variables h or i has numerical values >0, X independently of each other, is H, alkali metal ions, alkaline earth metal ions or other metal cations, positively charged derivatives of nitrogen, R and R′, independently of one another, are aliphatic, cycloaliphatic, aromatic hydrocarbon radicals or mixtures thereof is provided. The process includes in a first stage, adjusting an aqueous mixture consisting of the basic hydrolysis products of polysuccinimide and amine compounds to pH values of ≦3; andin a second stage, carrying out the aminolysis at temperatures between 140° and 200° C.

Dependencies are inferred from the claim text.