PURPOSE: The titled composition, containing a granular temperature sensitive color changing material prepared by coating a granular solid solution of a nonthermoplastic resin obtained from an acid coloring substance, an acidic substance and a solvent with a hydrophilic high polymeric film, having improved stability, and mixable with all kinds of printing ink.

CONSTITUTION: A composition containing a granular temperature-sensitive color changing material prepared by forming a solid solution from a component consisting of an acid coloring substance, e.g. a phthalide substance such as 4,4-bisdimethylaminodiphenyl-p-dimethylamino-o-carboxyphenylmethane lactam capable of changing the color violet-blue, an acidic substance, preferably a triazole compound, and a solvent, e.g. cetyl alcohol, with a nonthermoplastic resin, e.g. a melamine resin, and coating the resultant granular solid solution material with a hydrophilic high polymeric film, e.g. polyvinyl alcohol.

EFFECT: Improved solvent and heat resistance, and capable of changing the color sharply in various colors at a temperature in a wide range.