| 摘要 |
PURPOSE:To obtain the asphalt composition having excellent mechanical strengths, low-temperature properties, processability, etc., and a high softening point by mixing a specified block copolymer mixture with asphalt in a specified ratio. CONSTITUTION:The composition comprises 3-15 pts.wt. block copolymer mixture comprising 85-40wt.% block copolymer (A) comprising at least two polymer blocks based on a monoalkenyl aromatic compound (e.g. styrene) and at least one polymer block based on a conjugated diene compound (e.g. butadiene) and 15-60wt.% block copolymer (B) comprising at least one polymer block based on a monoalkenyl aromatic compound and at least one polymer block based on a conjugated diene compound and having a peak molecular weight equivalent of 1/3-2/3 of that of component A as measured by GPC and having a total combined alkenyl aromatic compound content in components A and B of 20-40%, a vinyl bond content in the conjugated diene compound of 50% or below, a melt viscosity (under conditions G) of 0.5-10 and a softening temperature of 80-130 deg.C. |
