PROPYLENE RESIN MADE SPOOL

摘要

PROBLEM TO BE SOLVED: To obtain a spool excellent in a rigidity, impact resistance and the like by composition of a propylene-ethylene block copolymer which specifies properties of a melt flow rate, a xylene-insoluble and -soluble component at ordinary temperature, respectively. SOLUTION: This spool is composed of a propylene-ethylene block copolymer wherein a melt flow rate (at 230 deg.C and 2.16 kg load) is 0.01-1000 g/10 min; a stereoregular index ratio of a xylene-insoluble component at ordinary temperature measured by 13C-NMR is not less than 98.9%; the xylene-soluble component at ordinary temperature is occupied with 3-50 wt.%; a component of T1 relaxation time measured by pulse NMR is composed of a sole relaxation component; an ethylene content measured by 13C-NMR is designated as x wt.%; and y (millisecond) of T1 relaxation time measured by pulse NMR satisfies an equation, y<=0.0014x3-0.0897x2-1.0593x+231.6. A nucleus-forming agent of 0.01-5 wt.% is preferably added to the same copolymer. The spool can wind wire automatically in a row winding state and prevent damage and disarray when transporting.