| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preparing a block copolymer by obtaining a crumb-like block copolymer through steam stripping and subjecting it to dehydration and solvent removal, wherein dehydration and solvent removal are efficiently conducted to yield the block copolymer having a low final concentration of a residual solvent and a quality (e.g. little amount of granular structure, transparency) required for its application to a sheet, a film, or the like. SOLUTION: In the preparation method for the block copolymer, a hydrocarbon solvent solution of a block copolymer comprising a vinyl aromatic hydrocarbon and a conjugated diene is subjected to steam stripping to obtain the crumb-like block copolymer. Then, the crumb-like block copolymer is dehydrated and hot-air dried at 70-95°C to achieve a moisture content of 5-20 mass% before being extruded from a biaxial extruder equipped with a deaerating slit and a deaerating vent part having a depressurizing means. COPYRIGHT: (C)2005,JPO&NCIPI |
