| abstract |
The object of the present invention is to obtain a polycarbonate having a high molecular weight, excellent in transparency and free from coloration from a dihydroxy compound and a diester of carbonic acid by transesterification. n A polycarbonate is produced by transesterification from a dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane and a diester of carbonic acid such as bisphenyl carbonate in the presence of a substance containing iron in an ammount of 50% by weight or less to contact the reactants. n Examples of the substance include silicates such as glass; polyfluoroethylene; and metals and metal alloys which contain at least one element selected from the group consisting of Ni, Cr, Mo, Al, Cu, Zn, Co, Mn and C, and iron in an ammount of 50% by weight or less. n A polycarbonate is produced by transesterification from a dihydroxy compound and a diester of carbonic acid in a reactor made of stainless steel and treated by electropolishing or acid pickling or buffed on a surface part thereof to contact the reactants. n As the transesterification catalyst, (a) a nitrogen-containing, electron-donating compound and (b) a nitrogen-containing, electron-donating compound and an alkali metal compound or an alkaline earth metal compound are preferably used. |