POLYPROPYLENE COMPOSITION

• Main Authors: MORI, KINYA, KOJIMA, OSAMU, SHIMOMURA, YOZO
• Format: Patent
• Language: English; French
• Published: 12.05.1992
• Edition: 5
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

A polypropylene composition capable of producing molded products having superior stiffness, impact resistance, transparency, resistance to whitening on impact on bending and luster is provided, which composition has (i) a styrene-ethylene?butylene-styrene block copolymer or a styrene-ethylene-propylene block copolymer each in 5 to 30% by weight based on the weight of the composition, blended with a highly crystalline propylene homopolymer (A) having a relationship between its isotactic pentad ratio (P) and melt flow rate (MFR) represented by an expression of 1.00 ? P ? 0.015 log MFR + 0.955; (ii) a styrene-ethylene?butylene-styrene block copolymer or a styrene-ethylene?propylene block copolymer each in 5 to 30% by weight based on the weight of the composition and an ethylene-propylene copolymer rubber or a polyethylene each in 15% by weight based thereon, blended with the above (A), the blending proportion of (A) being 60% by weight or more based on the weight of the composition; or (iii) a styrene-ethylene?butylene-styrene block copolymer or a styrene-ethylene?propylene block copolymer, each in 5 to 30% by weight based on the weight of the composition, an ethylene-propylene rubber and polyethylene each in 15% by weight or less based thereon, blended with the above (A), the blending proportion of (A) being 60% by weight or more based thereon.