| 摘要 |
The invention relates to a block copolymer composition comprising: from 100 to 20% by weight block copolymer (A) which comprises at least two polymer blocks mainly comprising a monoalkenylaromatic compound and at least one polymer block mainly comprising a conjugated diene; and from 0 to 80% by weight block copolymer (B) which comprises at least one polymer block mainly comprising a monoalkenylaromatic compound and at least one polymer block mainly comprising a conjugated diene and which has a peak molecular weight corresponding to from 1/3 to 2/3 the peak molecular weight of the block copolymer (A), wherein (1) the polymer blocks mainly comprising a monoalkenylaromatic compound have a molecular weight distribution of from 5 to 20 in terms of the ratio of the height (H) to half band width (W) of the peak in a chromatogram obtained by GPC (H/W); (2) the content of the polymer blocks mainly comprising a monoalkenylaromatic compound (BS) is from 10% by weight to less than 48% by weight; (3) the weight-average molecular weight (Mw) is from 100,000 to 500,000; and (4) the alkenylaromatic compound content (TS-BS) obtained by subtracting the content of the polymer blocks mainly comprising a monoalkenylaromatic compound (BS). from the total combined monoalkenylaromatic compound content (TS) is from 2 to 30% by weight. An asphalt composition containing the block copolymer composition of the invention is excellent in physical properties such as mechanical strength, softening point, and elongation, and in processability, and is excellent also in balance between these physical properties and processability and in storage stability.
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