METHOD FOR DRYING STYRENIC POLYMER

摘要

PROBLEM TO BE SOLVED: To provide a method which is a simplified process for removing the residual volatiles from an SPS powder and by which the volatiles such as an unreacted monomer can be removed at good efficiency without encountering a trouble i.e., the deposition of the powder on the equipment. SOLUTION: In removing the residual volatiles from a mainly syndiotactic styrenic polymer (SPS) by passing it through a drier, the drying is performed at a drying temperature of 20 deg.C or below (170 deg.C or below when the SPS is a styrene/p-methylstyrene copolymer containing at least 3mol% repeating p- methylstyrene units) to a liquid content (the weight of the volatiles×100/the total weight of the powder containing the volatiles) of 20wt.% or below, and is optionally continued at a temperature not higher than the melting point of the styrene polymer powder. It is also possible that the drier is a jacketed grooved one and is operated while a definite amount of an inert gas is being passed through it.