摘要 |
1. Process for the preparation of homogeneous aqueous solutions of saponified or partially saponified acrylonitrile polymers and copolymers by treating aqueous dispersions of the polymers or copolymers, respectively, with aqueous alkalis at elevated temperature, characterised in that the dispersion is added with continuous stirring to an aqueous alkali metal hydroxide solution which has been heated to 70 to 85 degrees C, and, after the addition is complete, the mixture is heated to a temperature of over 91 to 110 degrees C, while stirring, until the calculated amount of ammonia has been split off. |