PROPYLENE/ETHYLENE BLOCK COPOLYMER COMPOSITION EXCELLENT IN WEATHER RESISTANCE AND MOLDING PREPARED BY MOLDING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a block copolymer composition balanced between rigidity and impact resistance and being excellent in weather resistance by compounding a propylene/ethylene block copolymer with at least one compound selected from a weathering agent and a colorant. SOLUTION: This composition is prepared by compounding 100 pts.wt. (A) propylene/ ethylene block copolymer with 0.005-5 pts.wt. (B) weathering agent such as a hindered amide light stabilizer or a benzophenone ultraviolet absorber and a colorant and 0.001-1 pt.wt. dispersant such as a fatty acid metal salt. Component A has a melt flow rate of 0.01-1,000 g/10 min (as measured at 230 deg.C under a load of 2.16 kg) and a stereoregularity index fraction of at least 98.9% (a measured on a fraction insoluble in xylene at ordinary temperature by 13C-NMR spectroscopy). Further, it is one which has a content of a fraction soluble in xylene at ordinary temperature of 3-50 wt.%, in which the component having a T1 relaxation time as measured by pulsed NMR spectroscopy comprises a single relaxation component, and which satisfies the relationships [wherein y (millisecond) is the T1 relaxation time as measured by pulsed NMR spectroscopy and x (wt.%) is the ethylene content as determined by 13C-NMR spectroscopy].