| abstract |
PURPOSE: To obtain a polycarbonate resin having a stabilized degree of polymerization, low coloration and excellent heat resistance, by reacting 2,2-bia(4- hydroxyphenyl)propane purified in a specified method with phosgene. n CONSTITUTION: A solution obtaned by adding 0.5W3mol of a caustic alkali and 3W30pts.wt. water per pt.wt. caustic alkali to 1mol of 2,2-bis(4-hydroxyphenyl) propane is mixed or contacted with 0.02W2.0pts.vol., per pt.vol. of water, water- insoluble or difficulty water-soluble organic solvent (e.g., methylene chloride) and the organic solvent is separated from the mixture. To the separated water phase, the same solvent as above and a caustic alkali are added, the temperature of the solution is adjusted to about 20°C, and the polymerization is effected with agitation by blowing phosgene into the solution. n COPYRIGHT: (C)1986,JPO&Japio |