Melt transesterification process for the production of polycarbonates
申请人:Instituto Guido Donegani
公开号:US05221761A1
公开(公告)日:1993-06-22
A melt transesterification process for the production of polycarbonates, wherein at least one bis(aryl)carbonate is reacted with at least one dihydric phenol in the melted state, in the presence of a transesterification catalyst comprising at least one heterocyclic borate salt of the formula: M.sup.+ B(R).sub.n (A).sup.-.sub.4-n (I) where M.sup.+ is an alkali metal, tetra-alkylammonium, tetra-arylammonium, tetra-alkylphosphonium and tetra-arylphosphonium ion; R is H, alkyl, aryl or aralkyl; n is an integer from 0-3; and A is an aromatic or aliphatic heterocyclic ring.