Patent ID: 8324399

Claim:
A heat resistance improver comprising: a heat resistance improving component which has a benzotriazole skeleton having an electron attractive group and a reactive aliphatic hydroxyl group, wherein the heat resistance improving component is a compound represented by the following General Formula (2): where X 2 represents a hydrogen atom, a halogen atom, —NO 2 , —CN, —CF 3 or an alkyloxycarbonyl group; R 3 represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, —CHO or —CH═N—R 4 , where R 4 represents an alkyl group, an aryl group, an alkenyl group or an aralkyl group each of which may have a substituent; and n is an integer of 1 to 8; with the proviso that when X 2 is a hydrogen atom or halogen atom, then R 3 is —CHO or —CH═N—R 4 .