Thermoplastic polyolefins having improved paintability properties

Abstract

Thermoplastic polyolefin compositions of a substantially crystalline polyolefin that is a homopolymer of ethylene, propylene or butylene or a copolymer of propylene and a C.sub.3 -C.sub.10 alpha-olefin; about 10% to 50% by weight of a first substantially amorphous polyolefin of a terpolymer of ethylene with a C.sub.3 -C.sub.10 alpha-olefin and a diene monomer and having a Mooney Viscosity (ML.sub.1+4, 100.degree. C.) of between about 10 and about 120; optionally, a copolymer of ethylene and a C.sub.3 -C.sub.10 alpha-olefin may be present; and about 1 to 20% by weight of a second substantially amorphous polyolefin having a number average molecular weight of between about 1,000 and 15,000 and including (a) a copolymer of ethylene with a C.sub.3 -C.sub.10 alpha-olefin; (b) a terpolymer of ethylene with a C.sub.3 -C.sub.10 alpha-olefin and a diene monomer; (c) a block copolymer that includes blocks of a C.sub.3 -C.sub.10 alpha-olefin, butadiene, isoprene, styrene or alpha-methyl styrene; or (d) the reaction product of one of (a), (b) or (c) with a compound that provides a polar functional group. Also, articles of manufacture of these compositions in the form of a molded or extruded substrate having one or more surfaces, and a coating, such as a polyurethane, present on at least a portion of one or more of the surfaces of the substrate. The coating adheres well to the substrate as evidenced by resistance to immersion in gasoline for at least about 60 minutes with a coating peel area of less than 1% after immersion in gasoline for 30 minutes.

Dependencies are inferred from the claim text.