Patent ID: 6482877
Filing Date: 2002-11-19
Classification: C08G,C08K

Abstract:
A process for preparing a polycarbonate resin comprising:(A) melt polycondensing a bisphenol and a carbonic acid diester in the presence of an alkaline catalyst to form a reaction product, and subsequently adding a sufficient amount of sulfur-containing acidic compound to neutralize or weaken said catalyst, thereby forming a reaction product, (B) adding to said reaction product, (i) phosphorous acid (ii) a sulfur-containing acidic compound having a pKa of less than 3, or its derivative, and (iii) an ester derived from a mono-fatty acid of 10 and 22 carbon atoms and a polyhydric alcohol, wherein, in said resin, with respect to said reaction product, the content of phosphorous acid is 0.1 to 10 ppm and the content of the ester is 50 to 1,000 ppm and wherein the sulfur-containing acidic compound is added to said reaction product in two or more increment.