Method for producing resin foam, and resin foam

摘要

A method for producing resin foam including: melting a resin composition including a polyolefin resin and a thermoplastic elastomer; impregnating the molten resin composition with a material that is a gas at normal temperature and normal pressure, in a supercritical state, under a condition in which the supercritical state of the material is maintained; foaming the resin composition impregnated with the material by arranging the resin composition under a condition in which the supercritical state of the material is not maintained; and hot-pressing the foamed resin composition.

主权项

1. A method for producing non-crosslinked resin foam,
the method comprising: melting a resin composition including 100 parts by weight of a thermoplastic polyolefin resin other than an elastomer wherein the thermoplastic polyolefin resin includes a high melt tension random polypropylene having a first melt tension of 5 cN to 50 cN at 200° C., 35 parts by weight to 55 parts by weight of an amorphous thermoplastic elastomer, and a crystalline elastomer having a higher degree of crystallization than the amorphous thermoplastic elastomer, wherein the crystalline elastomer is a block copolymer of an linear low-density polyethylene and an ethylene-α-olefin copolymer other than an linear low-density polyethylene, and having a crystallization temperature of 90° C. or higher, wherein the amorphous thermoplastic elastomer is an ethylene-propylene rubber or an ethylene-α-olefin copolymer; impregnating the resin composition with a material, wherein the material is in supercritical state; foaming the resin composition impregnated with the material by arranging the resin composition under a condition in which the supercritical state of the material is not maintained; and hot-pressing the foamed resin composition.