Patent ID: 8853288

Claim:
A thermoplastic resin foam, comprising a bubbles with an average bubble diameter of 10 μm or less in the inside thereof, wherein the thermoplastic resin foam is prepared by using and foaming a thermoplastic resin composition containing 0.25 to 2.5 part(s) by mass of a melt-type crystallization nucleating agent (B), with respect to 100 parts by mass of an amorphous thermoplastic resin (A), wherein the amorphous thermoplastic resin (A) is polycarbonate, and wherein the melt-type crystallization nucleating agent (B) is a compound represented by the following formula (1): R 1 —(CONHR 2 ) a Formula (1) wherein R 1 represents a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 30 carbon atoms, a saturated or unsaturated alicyclic polycarboxylic acid residue having 4 to 28 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 28 carbon atoms; R 2 represents an alkyl group having 1 to 18 carbon atom(s), an alkenyl group having 2 to 18 carbon atoms, a cycloalkyl group or a cycloalkenyl group having 3 to 12 carbon atoms, a phenyl group, a naphthyl group, or an anthryl group; and a represents an integer from 2 to 6.