Patent ID: 8623930

Claim:
A thermoplastic resin foam, prepared by mixing a thermoplastic resin composition containing a melt-type crystallization nucleating agent (B) in a crystalline thermoplastic resin (A), which foam comprises bubbles having a mean bubble diameter of less than 1 μm in the inside thereof, wherein the melt-type crystallization nucleating agent (B) is one or more of N,N′-dicyclohexyl-2,6-naphthalenedicarboxamide, trimesic acid tris(t-butylamide), trimesic acid tricyclohexylamide, trimesic acid tri(2-methylcyclohexylamide), trimesic acid tri(4-methylcyclohexylamide), 1,4-cyclohexane dicarboxylic acid dianilide, 1,4-cyclohexanoic acid dicarboxylic acid dicyclohexylamide, 1,4-cyclohexanoic acid dicarboxylic acid di(2-methylcyclohexylamide), 1,4-cyclohexanoic acid dicarboxylic acid dibenzylamide, 2,6-naphthalene dicarboxylic acid dicyclohexylamide, 1,2,3,4-butane tetracarboxylic acid tetracyclohexylamide and 1,2,3,4-butane tetracarboxylic acid tetraanilide.