US Patent 7968638 Polyolefin composition with high filler loading capacity

Disclosed are highly filled thermoplastic olefin compositions and, in particular, thermoplastic olefin compositions that comprise propylene/alpha-olefin copolymers and a high level of organic or inorganic filler. Specifically, the description addresses a filled polymer composition comprising: (a) a first polymer component comprising propylene copolymer having a heat of fusion <about 75 J/g and a triad tacticity of from about 50% to about 99%, the first polymer component having a melt flow rate at 230° C. ≦about 800 g/10 min.; and (b) at least about 15% by weight of a filler, based on the total weight of the filled composition. Such compositions are useful as sound barriers, flame retardant compositions, roofing membranes, and the like.