| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing prefoamed particles, in which blocking is effectively prevented in prefoaming foamable thermoplastic resin particles comprising a thermoplastic resin having a relatively low glass transition temperature, from 40°C to 90°C, and which gives prefoamed particles of high uniformity. SOLUTION: The process for producing prefoamed particles comprises thermally foaming the thermoplastic resin particles under a reduced pressure in a range from 0.0074 MPa to less than 0.101 MPa by using a heating medium comprising a water vapor having a temperature adjusted to a range from 40°C to below 100°C corresponding to the reduced pressure. COPYRIGHT: (C)2003,JPO |
