Storage of phosphonium phenolate catalysts and their use as interesterification catalysts

摘要

A process for preparing a melt transesterification catalyst is disclosed. The process entails (i) obtaining a phenol adduct of phosphonium phenolatein the form of crystalline solid and (ii) storing the solid phenol adductin a closed container at relative humidity of 30 to 70 % and at temperature of -30 to 50° C. The thus prepared catalyst is suitable in the production of polycarbonate in the melt transesterification process.