Patent Number: 6,166,134

Title: Polypropylene resin composition with tapered triblock copolymer

Abstract: The present invention is a unique polypropylene copolymer resin composition which comprises a propylene-ethylene copolymer having a melt flow rate of at least 50 g/10 min and an impact modifier which comprises a thermoplastic elastomer of a hydrogenated triblock copolymer which has a specific structure in which a block of a tapered increment of an vinyl aromatic hydrocarbon portion is arranged after the isoprene homopolymer block. Accordingly, the present invention provides a polypropylene resin composition comprising(a) 55 to 87% by weight of a propylene-ethylene block copolymer having a melt flow rate of at least 50 g/10 minutes; and(b) 3 to 20% by weight of an impact modifier which is comprised of at least 50% by weight of a hydrogenated block copolymer having a number average molecular weight between 50,000 and 150,000 and containing 15 to 25% by weight of an vinyl aromatic hydrocarbon, obtained by hydrogenating a triblock copolymer having the structure A-B-(A/B) wherein A is a vinyl aromatic hydrocarbon homopolymer, B is an isoprene homopolymer, and (A/B) is a block of a tapered isoprene-vinyl aromatic hydrocarbon copolymer, and the balance an olefinic rubber; and(c) 10 to 25% by weight of talc.

Inventors: Modic; Michael John (Richmond, TX), Masuko; Norio (Tsukuba, JP)

Assignee: Shell Oil Company

International Classification: C08L 23/00 (20060101); C08L 23/10 (20060101); C08L 53/00 (20060101); C08L 047/00 (); C08L 053/02 ()

Expiration Date: 12/26/2013