| abstract |
The invention relates to multi-layer thermoplastic composites, and in particular composites having fluoropolymer in the outer layer and a thermoplastic substrate layer. The fluoropolymer outer layer may either be a layer comprising a majority, and preferably 100 percent fluoropolymer, or may be a blend of a thermoplastic matrix with fluoropolymer at a level of from 5 to 60 weight percent, based on the total weight of all polymers. Especially useful thermoplastic matrices include acrylic polymers, and styrenic polymers, especially styrenic copolymers such as acrylonitrile/styrene/acrylate (ASA), acrylonitrile/butadiene/styrene (ABS) and styrene/acrylonitrile (SAN). While the fluoropolymer may be any fluoropolymer, thermoplastic fluoropolymers, such as polymers and copolymers of polyvinylidene fluoride are especially useful. The improved flame retardant composite of the invention is especially useful in cap layers over plastic substrates, such as for flame-retardant plastic decking, railings, posts, fencing, siding, roofing, and window profiles. |