A heterophasic polypropylene resin comprising a polypropylene homopolymer matrix phase (A) and an ethylene-propylene copolymer phase (B) dispersed within the matrix, wherein the xylene soluble fraction of the heterophasic polypropylene resin is in the range 20 to less than 50 wt %; the heterophasic polypropylene resin has an MFR2 of 0.01 to 50 g/10 min; the ethylene content of the xylene soluble fraction of the heterophasic polypropylene resin is in the range of at least 20 wt % to less than 50 wt %; the heterophasic polypropylene resin has a notched charpy impact strength at −20 C of at least 25 kJ/m
2
, preferably at least 50 kJ/m
2
; and wherein the MFR
2
(Matrix)/MFR
2
(XS)≧5, preferably ≧10.
一种异相聚
丙烯树脂,包括聚
丙烯同聚物基质相(A)和分散在基质中的
乙烯-
丙烯共聚物相(B),其中异相聚
丙烯树脂的二
甲苯可溶分数在20至50重量%的范围内;异相聚
丙烯树脂的MFR2为0.01至50 g/10 min;异相聚
丙烯树脂的二
甲苯可溶分数的
乙烯含量在至少20重量%至50重量%的范围内;异相聚
丙烯树脂在-20℃下的缺口冲击强度至少为25 kJ/m2,最好至少50 kJ/m2;其中MFR2(基质)/MFR2(XS)≥5,最好≥10。