POLYSULPHONES AND POLYETHER SULPHONES WITH REDUCED YELLOW INDEX AND PROCESSES FOR THEIR PREPARATION

摘要

The present invention relates to a process for preparation of polysulphones with Yellowness Index to DIN 6167 smaller than 19 and of polyether sulphones with Yellowness Index to DIN 6167 smaller than 30, characterized in that the polymerization reaction is carried out in basic, aprotic solvents, using a mechanical agitator which passes close to the wall. The present invention also relates to the polyether sulphones and polysulphones obtainable for the first time by this process, and to the use of these polymers for production of mouldings, foils, membranes and foams.