Patent GB-1027974-A (GB)
Title: Improvements in or relating to polymer compositions
IPC: C08J3/11
Filed: 1964-04-20
Abstract: Homogeneous, flowable polymer compositions comprise a dispersion of particles of a vinyl fluoride polymer or copolymer with a minor proportion by weight of an ethylenically unsaturated comonomer, in an organic liquid which is non-volatile at room temperature, has a boiling point of at least 225 DEG  F. and has no substantial solvent action on the polymer at room temperature but which coalesces the polymer particles at an elevated temperature, and a polymeric thickening agent which is soluble in and imparts increased viscosity to the organic liquid dissolved in such dispersion in amount of 0.1 to 10 weight per cent of the dispersing medium.  The polymer may be polyvinyl fluoride or a copolymer of vinyl fluoride with olefins, halogen substituted olefins, vinyl esters, ketones and ethers, and unsaturated acids and the esters, amides, nitriles, anhydrides and halides thereof. Specified organic liquids are dimethyl formamide, dimethyl acetamide, cyclohexanone, acetophenone, tetramethyl urea, cyclic ethylene carbonate, nitrobenzene and isophorone.  The thickening agents may be low molecular weight vinyl fluoride polymers or copolymers, e.g. with vinylidene fluoride, trifluoroethylene or difluorochloroethylene, other polyvinyl halides, polyvinyl esters, polyalkyl acrylates and methacrylates, polyacrylonitrile, polystyrene and alkyd resins.  The compositions may also contain pigments, dyes, fillers, plasticizers and stabilizers, and may be used for coating metals, wood, plastics, leather, fabrics, ceramics and cement products, and for casting films.  Examples describe coating compositions comprising polyvinyl fluoride dispersed in solutions of (1) low molecular weight polyvinyl fluoride in dimethyl formamide, (3) polyvinylidene fluoride in dimethyl formamide and (4) polymethyl methacrylate in dimethyl acetamide.ALSO:Substrates may be coated with compositions comprising a dispersion of particles of a vinyl fluoride polymer or copolymer with a minor proportion by weight of an ethylenically unsaturated comononer in an organic liquid which is nonvolatile at room temperature, has a boiling point of at least 225 DEG F. and has no substantial solvent action on the polymer at room temperature but which coalesces the polymer particles at an elevated temperature, and a polymeric thickening agent which is soluble in and imparts increased viscosity to the organic liquid dissolved in such dispersion in amount of 0. 1 to 10 weight per cent of the dispersing medium.  Specified substrates are metals, e.g. steel, aluminium, iron, tin, magnesium and nickel, ceramics, concrete, cement, plastics, leather and fabrics.  The compositions may be applied by means of a doctor knife and cured by heating.  Thicker coatings may be prepared by repeated applications.  Specified organic liquids are dimethyl formamide, dimethyl acetamide, cyclohexanone, acetophenone, tetramethyl urea, cyclic ethylene carbonate, nitrobenzene and isophorone.  Specified thickening agents are low molecular weight vinyl halide polymers, polyalkyl acrylates and methacrylates, polyacrylonitrile, polystyrene and alkyd resins.  The compositions may also comprise pigments and other conventional additives.  In examples unprimed steel panels are coated with dispersions of polyvinyl fluoride in media comprising (1) a solution of low molecular weight polyvinyl fluoride in dimethyl formamide, and (2) a solution of polymethyl methacrylate in dimethyl acetamide; and aluminium panels are coated with a dispersion of polyvinyl fluoride in (3) a solution of polyvinylidene fluoride in dimethyl formamide.