WATER-CONTAINING OLEFINIC RESIN COMPOSITION AND PRE-EXPANDED PARTICLES COMPRISING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain the subject composition that can produce pre-expanded particles without use of a foaming agent by using polyolefin resin and hydrophilic polymer and specifying the water content of the composition to a prescribed proportion. SOLUTION: This objective composition comprises (A) a polyolefin resin, preferably polypropylene resin, (B) hydrophilic polymer particles with average particle size of or its hydrophilic domain (in the case that the dispersed particles form partially a hydrophilic domain) with particle size of <=100μm, preferably moisture-absorbing polymer or water-absorbing polymer where the water content of the polymer is 1-50 wt.%. This composition preferably contains (C) a filler, preferably talc in an amount of <=10 pts.wt. per 100 pts.wt. of the component A. The particles composed of this composition is pre-expanded by apparently 5-60 time foaming to give the objective pre-expanded particles with a closed cell proportion of 80-100% and the average foam diameter of 50-500μm.