Phosphonium borohydride compound and process for producing polycarbonate using said compound
AssigneeNational Science Council
InventorsChun-Shan Wang, Jen-Tau Gu
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Abstract
A process for producing a polycarbonate including melt polycondensing an aromatic dihydroxy compound and a carbonic acid diester in the presence of a phosphonium borohydride catalyst(I), ##STR1## wherein R is a straight-chain or branched alkyl group, or ##STR2## wherein each of R.sub.1, R.sub.2, and R.sub.3, independently is a C.sub.1 .about.C.sub.4 alkyl group. A colorless, transparent polycarbonate having a high molecular weight is obtained by using the phosphonium borohydride compound (I) as a transesterification catalyst, which may be used alone or incorporated with boric acid or a hindered phenol antioxidant.
Claims23
A process for producing a polycarbonate comprising melt polycondensing an aromatic dihydroxy compound and a carbonic acid diester in the presence of a transesterification catalyst, said process being characterized by the employment of a phosphonium borohydride catalyst of formula (I):
- ##STR15## wherein R is a straight-chain or branched alkyl group, or ##STR16## wherein each of R.sub.1, R.sub.2, and R.sub.3, independently is a C.sub.1 .about.C.sub.4 alkyl group.
A phosphonium borohydride compound of formula (I), ##STR19## wherein R is a straight-chain or branched alkyl group, or ##STR20## wherein each of R.sub.1, R.sub.2 and R.sub.2, independently is a C.sub.1 .about.C.sub.4 alkyl group.
Dependencies are inferred from the claim text.