| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: invention relates to polyolefin composition which are resistant to dynamic loading and to the method of producing said composition. The composition contains A) 60 to 95 wt % propylene (co)polymer of with polydispersity index (P.I) from 4.6 to 10 and isotactic pentad content (mmmm) over 98 mol %, determined using 13C-NMR spectroscopy for a fraction which is insoluble in xylene at 25C and B) 5 to 40 wt % ethylene copolymer, containing 40 to 70 wt % propylene or C4-C10 -olefins or their combination and, optionally, small diene proportions. The composition has temperature rising elution fractionation (TREF) profile, obtained through fractionation in xylene with tapping fractions at temperature 40C, 80C and 90C, in which ethylene content Y in the fraction tapped at 90C satisfies relationship (I): Yëñ-0.8+0.035X+0.0091X2, where X is ethylene content in the fraction tapped at 40C, and both values of X and Y are expressed in weight percent, and value of intrinsic viscosity [] of the fraction which is soluble in xylene at 25C ranges from 1.8 to 4.2 dl/g. ^ EFFECT: obtaining olefin polymer with good balance of properties, more specifically with high hardness and good resistance to dynamic loading. ^ 3 cl, 3 ex, 3 tbl |
