Patent ID: 8618205

Claim:
A thermal storage medium composition which comprises 100 parts by mass of a hydrogenated diene copolymer and 50 to 4000 parts by mass of a linear paraffin compound having 12 to 50 carbon atoms, the hydrogenated diene copolymer being a conjugated diene copolymer that is obtained by hydrogenating a block copolymer which includes a polymer block (A) that contains structural units (a-1) derived from a first conjugated diene compound and has a vinyl bond content of not more than 20 mol %, and a polymer block (B) that contains structural units (b-1) derived from a second conjugated diene compound and has a vinyl bond content of 30 to 95 mol %, the hydrogenation ratio with respect to the double bonds derived from the conjugated diene compounds being not less than 90%.