GB1048914A - Modified copolymers of olefins and unsaturated carboxylic acids - Google Patents

Abstract

Copolymers comprising at least 50 mole per cent of alpha-olefine units of the formula -RCH-CH2-, wherein R is hydrogen or a C1-C8 alkyl group, and 0.1 to 25 mole per cent of a -b -ethylenically unsaturated carboxylic acid halide units having 3 to 8 carbon atoms are prepared by reacting a corresponding olefine-unsaturated acid (or anhydride) copolymer with one or more halogenating agents. The product may comprise unreacted acidic groupings. Halogenation is generally carried out in an organic solvent, e.g. carbon tetrachloride, perchloroethylene, trichloroethylene or "Freon" (Registered Trade Mark); a solvent may be absent if thionyl chloride vapour is used as halogenating agent. Other suitable agents include carbonyl chloride, phosphorus trichloride and pentachloride and the equivalent bromine and fluorine compounds, e.g. phosphorus tribromide. The initial, acidic copolymers are obtained by copolymerizing an appropriate a -olefine with a suitable acid monomer, e.g. acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, maleic acid, fumaric acid, monoesters of such dibasic acids, e.g. methyl hydrogen maleate or fumarate or ethyl hydrogen fumarate, and maleic anhydride. The acid copolymers may also be obtained by copolymerizing the olefine with an unsaturated acid derivative, e.g. an ester, and converting the derivative to the free acid form. Also, the acid monomer may be graft polymerized on to a preformed polyolefine forming, e.g., a methacrylic acid-polypropylene graft copolymer (other examples also listed). The acid copolymer or graft copolymer may optionally comprise units of other monomers, e.g. methyl methacrylate, ethyl acrylate, acrylonitrile, styrene, vinyl methyl ether, vinyl acetate, vinyl alcohol, vinyl chloride, vinylidene chloride, vinyl fluoride and chlorotrifluoroethylene. In one example, an ethylene-methacrylyl chloride copolymer (obtained by reacting the corresponding acid polymer with PCl5) is further reacted by heating with KHF2 to convert half the acid chloride groups to acid fluoride groups. In another example, a (chlorinated ethylene)-methacrylic acid copolymer is converted to the acid chloride form. The acid halide copolymers are highly adhesive and are useful in forming laminates and coatings, and may be moulded into articles such as bottles.ALSO:Bottles blown from an ethylene-methacrylyl chloride copolymer are coated with a resin solution to decrease the permeability of the bottles to gases. Coating is effected by immersing the bottles in the resin solution, e.g. vinylidene chloride-acrylonitrile copolymer in methyl ethyl ketone, draining and heating in a vacuum oven to remove excess solvent. Copper wire is extrusion coated with an ethylene-methocrylyl chloride copolymer.