Provided are a propylene-ethylene block copolymer having MFR of from 0.01 to 1.0 g/10 min and comprised of (A) from 85 to 97 % by weight a 25°C xylene-insoluble fraction and (B) from 3 to 15 % by weight of a 25°C xylene-soluble fraction, wherein the fraction (A) is such that its stereospecificity index measured through 13C-NMR is at least 98.0 %, its intrinsic viscosity [η] falls between 2.5 and 5.5 dl/g, and its weight-average molecular weight, Mw, measured through GPC and the content, S, of the fraction having a molecular weight of at most 104.5 therein satisfy S (wt.%) ≤ -5.3 × 10-6Mw + 7.58, and the fraction (B) is such that its ethylene unit content measured through 13C-NMR falls between 30 and 70 % by weight, and its intrinsic viscosity [η] falls between 2.5 and 9.0 dl/g; and its blow-molded articles. The copolymer has good heat resistance, high rigidity, good impact resistance and good drawdown resistance, and its blow-molded articles have well-balanced rigidity and low-temperature barrier resistance.
提供了一种
丙烯-
乙烯嵌段共聚物,其 MFR 为 0.01 至 1.0 克/10 分钟,由 (A) 重量百分比为 85% 至 97% 的 25°C 二
甲苯不溶馏分和 (B) 重量百分比为 3% 至 15% 的 25°C 二
甲苯可溶馏分组成,其中馏分 (A) 通过 13C-NMR 测量的立体特异性指数至少为 98.0%,其固有粘度 [η] 介于 2.5 和 5.5 dl/g,通过
GPC 测得的重量平均分子量 Mw 和其中分子量不超过 104.5 的馏分含量 S 满足 S (wt.%) ≤ -5.3 × 10-6Mw + 7.58,馏分 (B) 通过 13C-NMR 测得的
乙烯单位重量含量介于 30% 和 70% 之间,其固有粘度[η]介于 2.5 和 9.0 dl/g 之间;及其吹塑制品。该共聚物具有良好的耐热性、高刚性、抗冲击性和抗拉性,其吹塑制品具有均衡的刚性和低温阻隔性。