To efficiently produce polycarbonate of excellent quality without a deteriorated product in the production process of polycarbonate by polymn. condensation of a reaction mixture by providing the passage to feed the reaction mixture with a narrowed and/or widened part having a specified characteristic structure.
As for the narrowed and/or widened part in the passage to feed the reaction mixture, a reducer having 1.6 s Rmax surface roughness as the finished state on the liquid contact part 4 is used, and the reducer is to the connected to pipings at each welded part 5 on the sides to a smaller piping side 2 and a larger piping side 3. The reducer has heat resistance against ≥150°C, causes no leak in ≤40000×10-6 MPa vacuum degree and has pressure resistance against ≥1.0 MPa. The liquid contact part 4 consists of a material having corrosion resistance against the reaction mixture and against monohydroxy compds. produced by the reaction of the reaction mixture. Preferably the reducer has ≤20° apex of the narrowed and/or widened part and a smooth surface without steps.
SHIMONARI MASASHI
SAWAKI TORU
SASAKI KATSUJI
