| abstract |
A method for producing a polycarbonate and the like which comprises employing a horizontal cylindrical vacuum apparatus for resin treatment having a side opening of a specific structure, feeding a polycarbonate melt to a unidirectionally rotary intermeshing type twin screw extruder under a specific condition, adding a specific agent under a specific condition and cleaning the inside of the apparatus for producing it by a specific method. The method can be used for producing a polycarbonate which is excellent with respect to hydrolyzability, the decrease in molecular weight during molding, thermal stability such as discoloration and forming property such as releasability, transferability and the like, is reduced in the deterioration due to the residence in a mold, such as discoloration, crosslinking, gel formation and the like, and is markedly reduced in the content of foreign substances. |