TPO BLENDS CONTAINING MULTIMODAL ELASTOMERS

摘要

Thermoplastic polyolefin blends having improved resistance to fluids such as petroleum fuels after being painted with flexible coatings such as polyurethanes paints and the like are disclosed. These blen ds include a crystalline or semi-crystalline polyolefin such as polyethylene, polypropylene, or a copolymer of ethylene and a C3 to C10 olefin, and a multimodal elastomer of sequentially polymerized ethylene-.alpha.-olefin monomers. The substantially crystalline polyolefin i s present in an amount of 30 to 98 weight percent, while the multimodal elastomer, which is substantially amorphous, is present in an amount of about 2 to 70 weight percent. The blends may contain additional polymeric components, fillers and the like. In addition to increased paint adherence, higher weld-line strength, low temperature ductility and processability can be achieved.