PROCESS FOR PRODUCTION OF POLYCARBONATE RESIN PELLETS

摘要

The present invention is a process for producing polycarbonate resin pellets, characterized by comprising the steps of: 1) using a polycarbonate resin having a specific powdery or granular form; 2) moving the polycarbonate resin in an inert gas atmosphere having an oxygen concentration of 3 vol% or less by allowing the polycarbonate resin to fall in the inert gas atmosphere 50 cm or more; 3) injecting a specified amount of water having an electrical conductivity of 30 µS/cm or less in a kneading zone of an extruder; 4) sucking an vent inlet so as to render the vent inlet in a pressure-reduced state and, at the same time, adjusting the water content in the resin to 10-200 ppm; 5) introducing a strand-shaped molten resin that is extruded through a die into water having an electrical conductivity of 30 µS/cm or less to thereby cool the molten resin; 6) cutting the strand at 70-130°C to produce pellets each containing 10-200 ppm of water; and 7) allowing the pellets each having a water content of 10-200 ppm thus produced to further absorb water in a wet atmosphere, thereby adjusting the water content of the pellets to a value greater than the initial water content of the pellets and equal to or lower than 1300 ppm.