Patent ID: 7696267

Claim:
An asphalt composition comprising from 0.5 to 50 parts by weight of a hydrogenated conjugated diene copolymer (a) and 100 parts by weight of asphalt (b), wherein the hydrogenated conjugated diene copolymer (a) is obtained by hydrogenation of a non-hydrogenated conjugated diene copolymer obtained by anion living polymerization of a conjugated diene monomer and a vinyl aromatic monomer using an organic alkali metal compound as a catalyst, and wherein the hydrogenated conjugated diene copolymer (a) comprises at least two homopolymer blocks (A) comprising vinyl aromatic monomer units and at least one hydrogenated copolymer block (B) obtained by hydrogenation of a non-hydrogenated random copolymer block comprising conjugated diene monomer units and vinyl aromatic monomer units, within the hydrogenated copolymer block (B), the weight ratio of the conjugated diene monomer units/the vinyl aromatic monomer units is from 53/47 to 80/20, the homopolymer block (A) and the hydrogenated copolymer block (B) both comprise a styrene chain, the styrene chains constituting the homopolymer block (A) and the hydrogenated copolymer block (B) are atactic, and the hydrogenated conjugated diene copolymer (a) has the following characteristics (1) to (5): (1) the content of the vinyl aromatic monomer units is more than 30% and not more than 60% by weight per weight of the hydrogenated conjugated diene copolymer (a); (2) the content of the homopolymer block (A) is from 5% to 50% by weight per weight of the hydrogenated conjugated diene copolymer (a); (3) the weight average molecular weight is from 30,000 to 500,000; (4) the percentage of hydrogenation of the double bonds in the conjugated diene monomer units is from 60% to 100%; and (5) at least one peak of the loss tangent (tan δ) is present in the range of from −40° C. to less than −10° C. in a dynamic viscoelastic spectrum obtained with respect to the hydrogenated conjugated diene copolymer (a).