METHOD FOR PRODUCING SKIN-COVERED POLYOLEFIN RESIN FOAMED MOLDED ARTICLE

摘要

A method for producing a skin-covered polyolefin-based resin foamed molded article, including blow-molding a polyolefin parison into a skin defining a hollow space; and placing multi-layered polyolefin expanded beads in the hollow space; and heating the expanded beads placed in the hollow space to fuse-bond the expanded beads together and to fuse-bond the expanded beads to the skin, wherein the expanded beads have specific apparent density, specific average diameter, specific endothermic peaks in their DSC curve and specific melting point characteristics.

主权项

1. A method for producing a skin-covered polyolefin-based resin foamed molded article, comprising the steps of:
extruding a melt comprising a polyolefin-based resin to form a parison in a softened state; blow-molding the parison into a skin defining a hollow interior space; filling multi-layered expanded beads comprising a polyolefin-based resin in the hollow interior space; and heating the multi-layered expanded beads filled in the hollow interior space to fuse-bond the multi-layered expanded beads to each other and to fuse-bond the mufti-layered expanded beads to the skin, wherein the multi-layered expanded beads fulfill the following requirements (a) to (d) (a) the multi-layered expanded beads have an apparent density of 0.03 to 0.2 g/cm3; (b) the multi-layered expanded beads have an average diameter of 1.5 to 3.5 mm; (c) the multi-layered expanded beads, when measured by heat-flux differential scanning calorimetry in which a sample thereof is heated from 23° C. to 220° C. at a heating rate of 10° C./min, gives a DSC curve which has an endothermic peak A intrinsic to the polyolefin-based resin of the multi-layered expanded beads and at least one endothermic peak B on a high temperature side of the endothermic peak A, and in which a ratio of the heat of fusion of the endothermic peak B to the total heat of fusion of the endothermic peaks is 0.15:1 to 0.25:1; and (d) the multi-layered expanded beads have a surface layer having a melting point lower than that of a region inside the surface layer.