ETHYLENE-PROPYLENE COPOLYMER, AND POLYPROPYLENE RESIN COMPOSITION COMPRISING THE SAME

摘要

Disclosed is an ethylene-propylene copolymer having the structural characteristics shown below. Also disclosed is a polypropylene resin composition comprising the copolymer and a polypropylene having a melting temperature of 160°C or higher. (1) The propylene content is 20 to 60 mol%. (2) The product of the monomer reactivity ratios is smaller than 2.5. (3) The intrinsic viscosity is larger than 1.0 dl/g. (4) The molecular weight distribution is larger than 3. (5) The glass transition temperature is lower than -40°C. (6) The amount of heat of crystallization is smaller than 5.0 J/g. (7) The amount of the copolymer dissolved at a temperature lower than 10°C is 60 wt% or more, that at a temperature not lower than 10°C and lower than 55°C is 3 wt% or more, and that at a temperature not lower than 83°C is 5 wt% or more, each relative to the total amount of the copolymer dissolved, as measured by a temperature rising elution fractionation method. (8) The ratio of the intensity of a racemic peak to that of a meso peak in a <SUP>13</SUP>C-NMR spectrum at an ethylene-propylene binding part is 0.01 to 0.7.