HIGH HEAT-SEALABLE COATED POLYOLEFIN FILMS

摘要

1529584 Coated polyolefin films DAICEL Ltd 19 Dec 1975 [27 Dec 1974 6 Feb 1975] 52027/75 Heading B2E A polyolefin film is coated (i) with a composition comprising (a) a graft copolymer of vinyl chloride, vinylidene chloride, styrene, or nuclear- or alpha-substituted styrene on to a chlorinated polypropylene resin, (b) acrylonitrile-butadiene rubber and optionally (c) up to 70 wt. % chlorinated polypropylene resin, and then with (ii) a vinylidene chloride copolymer emulsion. The film is polypropylene or poly-4-methylpentene-1 and may be a biaxially-stretched crystalline material. The graft copolymer may include 2-30 wt. % the grafted monomer(s), said monomer(s) may include up to 50 wt. % other vinyl monomers, suitable ones being listed. The chlorinated copolymer may have a Cl content of 15-5i wt. % and an intrinsic viscosity of 0.3-3.0 dl/g (conditions defined). The ratio of (a) to (b) may be 95:5-5:95, preferably 75:25-25:75. The copolymer of (ii) may contain 80-95wt.% vinylidene chloride, suitable comonomers are listed (acrylic ester, alone or with vinyl chloride, being used in examples). The acrylonitrile - butadiene rubber may comprise 19-41 wt. % acrylonitrile. The coating compositions may include conventional additives. Total coating thickness may be 1-10 microns, with the ratio of (ii) to (i) being 1:20-20:1. The film may be pre-treated by corona discharge, H.F. electric field, flame or chromic acid.