This invention relates to a polypropylene bumper cover composition, particularly to a polypropylene bumper cover composition with improved contraction rate, painting properties, and molding properties. This composition includes 55 to 70 wt % of a polypropylene resin, 28 to 45 wt % of an ethylene-propylene rubber component, 2 to 5 wt % of an inorganic filler, 1 to 2.5 wt % of high density polyethylene, and 2.5 to 7 wt % of oxidation inhibitor, lubricant and carbon black. The ethylene-propylene rubber component may include two ethylene-propylene rubbers having different Mooney viscosities. The inorganic filler can be talc or fine talc.
The present invention relates to a polyolefin-based composite resin composition having excellent dimensional stability due to low mold shrinkage, low linear thermal expansion coefficient and low heat sag as well as having excellent mechanical strength, impact resistance, heat resistance, injection molding plasticity and surface smoothness of a product. The composition includes: 30-80% by weight of a crystalline ethylene-propylene copolymer; 5-40% by weight of an ethylene-.alpha.-olefin copolymer; 5-40% by weight of an inorganic fortifier; and additives.
The present invention relates to polypropylene compositions for forming articles through extrusion. These parts are particularly useful in automotive body side moldings applications. In one embodiment, the invention is directed to an extruded resin material comprising (a) a skin layer of polypropylene polymer and (b) a core layer composition comprising a polypropylene polymer with an impact modifier and an inorganic filler. The core composition preferably comprises about 25-30 percent by weight of the impact modifiers. The impact modifier is preferably a copolymer of ethylene and a higher alpha olefin. The inorganic filler is present in an amount of about ten percent by weight.
An air bag cover for a passenger of an automobile, obtained by molding a thermoplastic elastomer composition which comprises an olefin-based resin (A) and an ethylene-.alpha.-olefin-based copolymer rubber (B), and provides a 2 mm thick molded body composed of the composition having a linear thermal expansion coefficient at a temperature of -40 to 120.degree. C. of 13.5.times.10.sup.-5 mm/m.degree.C. or less, a fracture elongation at weld part of 50% or more, and an Izod impact strength at a temperature of -50.degree. C. or more of 35 kg.multidot.cm/cm or more, or revealing Non Break. According to the present invention, there can be provided an air bag cover for a passenger side seat of an automobile, which does not cause building up or separation from surrounding parts when installed and set into a dash board of the automobile, and has excellent safety in spreading.
