Patent ID: 6818690
Filing Date: 2004-11-16
Classification: C08F,C08J,C08K,C08L

Abstract:
A propylene-ethylene block copolymer composition for automobile exterior parts, comprising a propylene-ethylene block copolymer having a melt flow rate (MFR) of 12 to 16 g/10 min and a nucleating agent comprising methylenebis(2,4-di-t-butylphenol) acid sodium phosphate, said nucleating agent blended with the propylene-ethylene block copolymer in an amount of 300 to 2,000 ppm when the propylene-ethylene block copolymer is granulated, and said composition having:(a) a melt flow rate (MFR) of 10 to 18 g/10 min when measured at 230Â° C. under a load of 2.16 kg (21.2N); (b) a 25Â° C. xylene insoluble having a stereoregularity index [mmmm] fraction of 98.9% or higher when measured by C13-NMR; and (c) a 25Â° C. xylene soluble wherein the xylene soluble: (c-1) is present in an amount of 22 to 28% by weight based on the propylene-ethylene block copolymer; (c-2) comprises only a single component with respect to a relaxation time T1 measured by pulse NMR; and (c-3) satisfies the following formula (1): y&lE;0.0014x3âˆ’0.0897x2âˆ’1.0593x+231.6â€ƒâ€ƒ(I) â€ƒwherein x is an ethylene content (% by weight) measured by 13C-NMR and y is the relaxation time T1 (msec) measured by pulse NMR.