PRODUCTION OF FOAM OF THERMOPLASTIC POLYESTER RESIN COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a process for simply and stably producing a foam made from a thermoplastic polyester resin composition and having uniform and fine cells. SOLUTION: This process comprises feeding 100 pts.wt. thermoplastic polyester resin (A), 0.05-5 pts.wt. polybasic carboxylic acid (B) having at least three carboxyl groups and 0.01-3 pts.wt. compound (C) which accelerates the molecular-weight-increasing reaction when component of components A and B are melt-mixed in a vacuum into a vented extruder connected to a vacuum apparatus, melt-mixing them while evacuating the extruder through vent holes, mixing the obtained thermoplastic polyester resin composition with a blowing agent to obtain an expandable composition and extruding the expandable composition into a low-pressure region to produce a foam.