Patent ID: 6162887
Filing Date: 2000-12-19
Classification: C08F,C08L,Y10T

Abstract:
A highly crystalline polypropylene, characterized byhaving a degree of crystallinity of at least 50.5% calculated from the heat of fusion; and(1) having a relationship between a proportion of R-lamella f(R) with respect to spherulites and a weight-average molecular weight Mw which satisfies the following Formula (II);(2) wherein said proportion of R-lamella f(R) with respect to spherulites is calculated using the following Formula (I), in which a birefringence .DELTA.n of crystallized spherulites is obtained by melting said highly crystalline polypropylene at 230.degree. C. for 5 minutes, cooling to a temperature of 132.degree. C. at a cooling rate of 20.degree. C./minute, and then maintaining said temperature for 90 minutes;f(R)=(-.DELTA.n+0.0351).times.100/0.0528 Formula (I)f(R)>-2.5.times.(log {Mw}-4).sup.2 +88.9 Formula (II).