| abstract |
A highly crystalline polypropylene having a degree ofncrystallinity of at least 50.5% calculated from the heat ofnmelting; and a relationship between a proportion f(R)of R-lamellanwith respect to spherulites and a weight-averagenmolecular weight Mw which satisfies the following Formula (II).nThe above-mentioned proportion f(R) of R-lamella spherulites isncalculated using the following Formula (I) from thenbirefringence Δn of crystallized spherulites obtained by meltingnsaid highly crystalline polypropylene at 230°C for 5 minutes,ncooling to a temperature of 132°C at a cooling rate ofn20°C/minute, and then maintaining said temperature for 90nminutes. Molded articles obtained using the above-mentionednhighly crystalline polypropylene or a resin compositionncontaining the above-mentioned highly crystalline polypropylenenresin are superior in rigidity, heat resistance, scratchnresistance, dimensional stability, and low production of odornduring molding, and can be widely used in various applications.n f(R) = ( - Δn + 0.0351) X 100/0.0528 f(R) > - 2.5 X (log{Mw} -4) 2 + 88.9 |