| 摘要 |
A propylene resin composition which is a three-component material is improved in rigidity, heat resistance, and impact resistance while maintaining a satisfactory balance among these and further improved in low-temperature (about -30° C.) impact resistance. A propylene resin composition comprising: 60-95 wt % of a crystalline propylene polymer ingredient (a) comprising a propylene homopolymer ingredient or a copolymer of propylene and up to 3 wt % ethylene or an alpha-olefin having 4-20 carbon atoms; and 40-5 wt % of a propylene/ethylene copolymer ingredient (b), wherein the ingredients are polymerized using a metallocene catalyst, and the composition satisfies the following properties i) to iv): i) A melting point obtained by differential scanning calorimetry (DSC) is 156° C. or higher, ii) A proportion of the copolymer ingredient (b) determined by a temperature rising elution fractionation (TREF) fractionating at three levels of temperature of 40° C., 100° C., and 140° C., is 5-40 wt %, iii) An ethylene content of the copolymer ingredient (b) determined by a temperature rising elution fractionation (TREF) fractionating at three levels of temperature of 40° C., 100° C., and 140° C., is 30-50 wt %, and an average ethylene content in components eluting at 40-100° C. is 10 wt % or lower, and iv) The propylene/ethylene copolymer ingredient (b) comprises at least two kinds of propylene/ethylene copolymer ingredients (b-1) and (b-2), each of which differs in ethylene content, wherein an ethylene content of the ingredient (b-1) and an ethylene content of the ingredient (b-2) are 15-30 wt % and 40-55 wt %, respectively, and the ratio of the amount of ingredient (b-1) to that of ingredient (b-2), (b-1):(b-2), is in the range of from 1:99 to 40:60.
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