Polymeric aminophosphonocarboxylic acids, alkali metal salts thereof, and the use thereof

摘要

The invention relates to polymeric aminophosphonocarboxylic acids of the formula <IMAGE> having degrees of polymerisation a and b of between 3 and 200, and to a process for the preparation thereof, in which polyacrylonitriles having a degree of polymerisation of from 6 to 1,500 are reacted with phosphorous acid at temperatures of 80-160 DEG C. The novel substances are used as dispersants, corrosion inhibitors and heat stabilisers.