Polypropylene or polymethylpentene film coated with graft undercoat mixture and vinylidene chloride copolymer top coating

Claim 1

A polypropylene or poly-4-methylpentene-1 film coated with I. an undercoating consisting essentially of a mixture of a. a graft polymer of chlorinated polypropylene, as the backbone polymer, having grafted thereto from 2 to 30 percent by weight, based on the weight of the graft polymer, of either a chlorinated vinyl monomer or a styrene monomer, wherein said chlorinated polypropylene has a chlorine content of from 15 to 55 percent by weight and has an intrinsic viscosity of from 0.3 to 3.0 dl/g, wherein intrinsic viscosity is determined by measuring the viscosity of a solution of 0.2 to 0.5 percent by weight of said chlorinated polypropylene in decalin at 135° C., wherein said chlorinated vinyl monomer contains from 50 to 100 percent by weight of vinyl chloride, vinylidene chloride, or mixtures thereof, and the balance is a vinyl monomer or a mixture of vinyl monomers copolymerizable with vinyl chloride or vinylidene chloride, wherein said styrene monomer contains 50 to 100 percent by weight of styrene, or nucleus-substituted styrene, or α-hydrogen substituted styrene, or mixtures thereof, and the balance is a vinyl monomer or a mixture of vinyl monomers copolymerizable with said styrene monomer, b. acrylonitrile-butadiene rubber; wherein the weight ratio of a/b is from 95/5 to 5/95, and c. zero to 70 percent by weight of said chlorinated polypropylene, and, Ii. a top coating consisting essentially of a vinylidene chloride copolymer containing from 80 to 95 weight percent of vinylidene chloride monomer units.