| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject pre-foamed granules which have good foamability in molds and can express the good surface properties and antistatic properties, and the like of molded articles, by using a polyolefin-based resin containing a surfactant and a specific hydrophilic polymer as a base resin for the pre-foamed granules. SOLUTION: The pre-foamed granules of an antistatic polyolefin-based resin are obtained by preliminarily foaming 100 pts.wt. of a polyolefin-based resin which contains (A) 0.5 to 15 pts.wt. of a hydrophilic polymer (preferably a polyetherpolyesteramide, a quaternary ammonium salt group-containing copolymer or the like) and (B) 0.01 to 5 pts.wt. of a surfactant (preferably a nonionic or cationic surfactant). The pre-foamed granules are preferably obtained by dispersing the polyolefin-based resin granules together with a dispersant in an aqueous dispersing medium in a closed vessel, introducing a foaming agent into the dispersion, heating the mixture at a temperature above the softening point of the used polyolefin-based resin, and then releasing the heated mixture from one end of the closed vessel into a lower pressure atmosphere to foam the resin granules. |
