To obtain a biodegradable foamed particle which yields a molded article having a good appearance both on the surface and in the cross section by using a polyester-based resin particle which has a specific amount or more of chloroform insolubles in the inner part.
This foamed particle has chloroform insolubles of 20 wt.% or more in the inner part. The foamed particle molded article made from this foamed particle has chloroform insolubles of 5 wt.% or more and has bubbles with a maximum particle diameter of 2 mm or more at a density of 0.07/cm2 or less in the cross section of the molded article. As the base resin, a polyester- based resin containing at least 60 mol% of aliphatic ester bonds in the main chain is preferable and the polyester-based resin preferably has a Vicat softening point of 50-140°C as measured according to JIS K7206. The foamed particle is preferably prepared by dispersing a base resin particle in a dispersion medium in a closed container, adding a crosslinking agent and an auxiliary to increase the chloroform insolubles as necessary, heating the same to crosslink, and foaming.
SHINOHARA MITSURU
TOKIWA TOMOO
TOKORO TOSHIO
