POLYPROPYLENE RESIN COMPOSITION FOR ORIENTED FILM HAVING IMPROVED ELECTRICAL PROPERTIES

摘要

PURPOSE:To provide a polypropylene resin compsn. for oriented film having excellent electrical properties, comprising a polypropylene compsn. with specified kerosine-sol. fraction, boiling n-heptane extraction residue of kerosine insol. fraction, and melt flow index. CONSTITUTION:A polypropylene resin compsn. with a kerosine (30 deg.C)-sol. fraction =2wt%; a boiling n-heptane extraction residue of kerosine (30 deg.C)-insol. fraction =92wt%; and a melt flow index of 10-0.01g/10min, is given. When the kerosine-sol. fraction is above 2wt%, electrical properties are imferior, and modulus of elasticity and tensile break strength are insufficient. When the boiling n-heptane extraction residue is below 92wt%, electrical properties, in particular breakdown voltage, are low and unagreeable. A melt flow index (JIS K-7210) of 10-0.01g/10min is required for forming film.