| abstract |
PCT No. PCT/JP97/02659 Sec. 371 Date Mar. 30, 1998 Sec. 102(e) Date Mar. 30, 1998 PCT Filed Jul. 31, 1997 PCT Pub. No. WO98/04600 PCT Pub. Date Feb. 5, 1998A highly crystalline polypropylene having a degree of crystallinity of at least 50.5% calculated from the heat of melting; and a relationship between a proportion f(R)of R-lamella with respect to spherulites and a weight-average molecular weight Mw which satisfies the following Formula (II). The above-mentioned proportion f(R) of R-lamella spherulites is calculated using the following Formula (I) from the birefringence DELTA n of crystallized spherulites obtained by melting said highly crystalline polypropylene at 230 DEG C. for 5 minutes, cooling to a temperature of 132 DEG C. at a cooling rate of 20 DEG C./minute, and then maintaining said temperature for 90 minutes. Molded articles obtained using the above-mentioned highly crystalline polypropylene or a resin composition containing the above-mentioned highly crystalline polypropylene resin are superior in rigidity, heat resistance, scratch resistance, dimensional stability, and low production of odor during molding, and can be widely used in various applications. f(R)=(- DELTA n+0.0351)x100/0.0528 Formula (I) f(R)>-2.5x(log{Mw}-4)2+88.9 Formula (II). |