PURPOSE: To obtain a high molecular weight aromatic polycarbonate free from a halogen by preparing a partially crystalline oligomeric initial condensate by the interfacial method with the use of an organic solvent immiscible with water and containing no halogen and then, subjecting the initial condensate in the state of a melt or a solid to the final condensation.
CONSTITUTION: In preparing an aromatic polycarbonate free from a halogen by a two-stage method, in the first stage by using an interfacial method with the use of an organic solvent immiscible with water and free from a halogen, an aqueous solution containing bisphenol A and NaOH is mixed with toluene and phosgene is introduced thereinto under vigorous stirring to obtain a partially crystalline initial condensate and then, the formed precipitate is separated and washed and subsequently in the second stage this product in the state of a melt or a solid is subjected to the final condensation under heating to obtain a desired high molecular weight polymer.
URURITSUHI GURIGO
DEIITAA FURAITAAKU
KURAUSU BURUFU
GERUTO FUENGURAA
