PURPOSE: To provide the titled polymer having granular form after polymerization, having specific bulk density, ratio of average molecular weight, intrinsic viscosity, steric pentad fraction, melt flow ratio, melting point and heat of fusion, etc., and having excellent physical and mechanical properties and high processability.
CONSTITUTION: The objective polymer is prepared by the vapor-phase polymerization of propylene and has the following characteristics. The form of the polymer after polymerization, granular; bulk density, ≥0.27g/ml; ratio of weight- average molecular weight/number-average molecular weight, 10W100; intrinsic viscosity [η], 0.8W10dl/g; ratio of [mmmm] fraction in steric pentad fraction, 0.45W 0.85 determined by 13C-NMR; melt flow ratio (MFR) satisfying the formula I (MI is melt index); melting point, 154W164°C; heat of fusion, 5W22cal/g; the intrinsic viscosity of the fraction soluble in boiling heptane (HSP) and that of the fraction insoluble in boiling heptane (HIP), satisfies the formula II; the [mmmm] fraction of the fraction insoluble in boiling heptane, 0.60W0.90 determined by 13C NMR; the sum of fractions of [mmmr], [rrrm] and [rrrr], 0.07W 0.30.
NAKAE KIYOHIKO
OGAWA TADATOSHI
