COMPOSITION POUR MATERIAU DE STOCKAGE DE CHALEUR, ET MATERIAU DE STOCKAGE DE CHALEUR

Provided is a composition for a heat-storage material enabling the production of a heat-storage material, which shows neither phase separation nor bleeding of liquid phase even at a temperature higher than the maximum crystal transition temperature of a paraffin compound, has excellent shape retention properties, and is highly flowable in a molding process. The composition for a heat-storage material comprises 100 parts by mass of a hydrogenated diene-based copolymer and 50-4000 parts by mass of a paraffin compound, wherein said hydrogenated diene-based copolymer is obtained by hydrogenating a block copolymer, which comprises block (A) containing a structural unit (a-1) derived from a conjugated diene compound and having a vinyl bond content equal to or less than 20 mol%, and block (B) containing a structural unit (b-1) derived from a conjugated diene compound and having a vinyl bond content of 30-95 mol%, the hydrogenation rate of double bonds derived from aforesaid conjugated diene compounds being equal to or greater than 90%.