MODIFYING MATERIAL FOR BITUMEN

PURPOSE:To obtain an improving material for bitume, composed of a hydrogenated block copolymer containing a vinyl aromatic compound and a conjugated diene, a mixture thereof with a nonopolar polymer, an ethylene-alpha-olefinic copolymer, etc., and capable of providing the bitumen good in thermal stability and durability. CONSTITUTION:This improving material for bitumen is obtained by blending a hydrogenated diene-based copolymer, composed of a block such as a vinyl aromatic compound polymer block, a conjugated diene polymer block, a vinyl aromatic compound-conjugated diene random copolymer block or a vinyl aromatic compound-conjugated diene tapered block in which the content of the vinyl aromatic compound is progressively increased at (5-60)/(95-40) weight ratio of the vinyl aromatic compound/conjugated diene and having >=80% hydrogenated double bond in the conjugated diene part and 50000-600000 number- average molecular weight, a mixture thereof with a nonpolar (co)polymer, an ethylene-3-20C olefin-nonconjugated diene-based copolymer and a butyl-based rubber, etc., as principal components with other components respectively. This improving material is capable of providing the bitumen excellent in thermal stability and durability.