GB1035566A - Coating composition - Google Patents

Abstract

Aerosol coating compositions comprise a propellant and a coating composition comprising particles of a polytetrafluoroethylene wax of molecular weight 1000 to 150,000 dispersed in an organic solvent solution of a high molecular weight, film-forming polymer, the total polymer solids being 0.1 to 30 weight per cent of which 1 to 99 weight per cent is polytetrafluoroethylene. Specified propellants are ethane, propane, butane, trichlorofluoromethane, dichlorodifluoromethane and trichlorofluoroethane. Specified polymers are cellulose ethers and esters, vinyl resins, acrylic resins, polystyrene and natural and synthetic rubbers. Many solvents are listed and optional ingredients include fillers and pigments, thickening agents, antifoams and antiseptic agents. Example 9 describes an aerosol composition comprising polytetrafluoroethylene, nitrocellulose, zinc stearate, magnesium carbonate, castor oil, carbon tetrachloride, ethyl acetate, butyl acetate, denatured alcohol, monofluorotrichloromethane and difluorodichloromethane.ALSO:Coating compositions comprise particles of a polytetrafluoroethylene wax of molecular weight 1000 to 150,000 dispersed in an organic solvent solution of a high molecular weight polymeric material, said solution having the ability to form a film when dried at normal temperature and the total polymer solids content being 0.1 to 30% by weight of which 1 to 99 weight per cent is polytetrafluoroethylene wax. The polytetrafluoroethylene wax may be prepared by polymerizing tetrafluoroethylene in the presence of free radical initiators and telogens, many examples of which are listed, or by pyrolysing high molecular weight polytetrafluoroethylene resins. Specified high molecular weight polymers are methyl cellulose, ethyl cellulose, nitrocellulose, cellulose acetate, cellulose propionate, cellulose acetate propionate, cellulose acetate butyrate, cellulose triacetate, polyvinyl acetal, polyvinyl butyral, polyvinyl acetate, vinyl ester/acrylic ester copolymers, polystyrene, polyacrylic esters, polymethacrylic esters, polyvinyl chloride, vinyl chloride/vinyl acetate copolymers, polychloroprene, nitrile rubbers and natural rubber. Long lists of suitable solvents are given, including alcohols, ether alcohols, ethers, cyclic ethers, esters, ketones, aromatic hydrocarbons, halogenated hydrocarbons, phenols and aniline. The compositions may also comprise pigments and fillers, e.g. chrome pigments, ultramarine, iron oxide, aluminium stearate, zinc stearate, calcium carbonate, magnesium silicate, carbon black, barytes, asbestos, silica, titanium white; thickeners, e.g. Dammar gum, Elemi gum, shellac, alkyd resins, maleic modified resin, ester gum, phenolic resin, urea resin and organic titanates; antifoams, e.g. octyl alcohol; antiseptic agents, e.g. pentachlorophenol; and aerosol propellants, e.g. alkanes and haloalkanes. The compositions may be applied to articles to give lubricant, soil-resistant, parting, water- and oil-repellent and anti-corrosive coatings. Examples describe the preparation of waxes by (1) pyrolysing polytetrafluoroethylene in the presence of potassium nitrate and (2) telomerizing tetrafluoroethylene in carbon tetrachloride and dimethylformamide in the presence of azodiisobutyronitrile; and the preparation of coating compositions from polytetrafluoroethylene waxes and (1) cellulose acetate, triphenyl phosphate, acetone, ethyl acetate, ethyl lactate, nitropropane, butanol, methoxyethyl acetate and toluene; (2) nitrocellulose, Dammar gun, dibutyl phthalate, cyclohexanone, methoxyethanol, ethyl acetate, butyl acetate, amyl acetate, methanol, ethanol and benzene; (3) benzyl cellulose, Manila copal, benzene, methanol and butylene glycol; (4) polyvinyl acetate, butyl phthalate, carbon tetrachloride, ethyl acetate, butyl acetate, methanol and benzene; (5) vinyl chloride/vinyl acetate copolymer, dioctyl phthalate, carbon tetrachloride, ethyl acetate, acetone and benzene; (6) polystyrene, tricresyl phosphate, carbon tetrachloride and benzene; (7) polyvinyl butyral, nitrocellulose, tricresyl phosphate, carbon tetrachloride, ethanol, butanol, benzene and cyclohexane; (8) nitrocellulose, dibutyl phthalate, carbon black, carbon tetrachloride, ethyl acetate, n-butyl acetate and butanol; (9) nitrocellulose, zinc stearate, magnesium carbonate, castor oil, carbon tetra-chloride, ethyl acetate, butyl acetate, denatured alcohol, monofluorotrichloromethane and dichlorodifluoromethane; and (10) polystyrene, nitrile rubber, tricrosyl phosphate, carbon tetrachloride and toluene.ALSO:Articles may be coated with composition comprising particles of a polytetrafluoroethylene wax of molecular weight 1,000 to 150,000 dispersed in an organic solvent solution of a high molecular weight polymeric material, the solution having the ability to form a film when dried at normal temperatures and the total polymer solids being 0.1 to 30 weight per cent of which 1 to 99 weight per cent is polytetrafluoroethylene. The compositions may be applied to wood, metals, plastics, glass and rubber to provide lubricant and soil resistant coatings, e.g. on values, hinges, screws, sliding doors, drawers, cutting implements and cooking utensils, containers, skis, skates, ropes and wires, sieves, tents, lawn mowers, ploughs, rakes and refrigerators. The high molecular weight polymers may be cellulose esters and ethers, polyvinyl acetals, polyvinyl esters, acrylic resins, polystyrene, vinyl chloride resins and natural and synthetic rubbers. Many solvents are listed including alcohols, ether alcohols, ethers, esters, ketones, aromatic hydrocarbons, halogenated hydrocarbons, phenols and aniline. The compositions may also comprise fillers and pigments; thickeners, e.g. gums and resins; antifoams, e.g. octyl alcohol; antiseptic agents, e.g. pentachlorophenol; and aerosol propellants, e.g. alkanes and halogenated alkanes. Examples describe the application of compositions comprising (1) polytetraethylene, cellulose acetate, triphenyl phosphate, acetone, ethyl acetate, ethyl lactate, nitropropane, butanol, methoxyethyl acetate and toluene and (10) polytetrafluoroethylene, polystyrene, nitrile rubber, tricresyl phosphate, carbon tetrachloride and toluene to drawer slides; (2) polytetrafluoroethylene, nitrocellulose, Dammar gum, dibutyl phthalate, cyclohexanone, methoxyethanol, ethyl acetate, butyl acetate, amyl acetate, methanol, ethanol and benzene to skis; (3) polytetrafluoroethylene, benzyl cellulose, Manila copal, benzene, methanol and butylene glycol to wood; (4) polytetrafluoroethylene, polyvinyl acetate, butyl phthalate, carbon tetrachloride, ethyl acetate, methanol and benzene to rubber valve washers; (7) polytetrafluoroethylene, polyvinyl butyral, nitrocellulose, tricresyl phosphate, carbon tetrachloride, ethanol, butanol, benzene and cyclohexane to metals; and (9) polytetrafluoroethylene, nitro-cellulose, zinc stearate, magnesium carbonate, castor oil, carbon tetrachloride, ethyl acetate, butyl acetate, denatured alcohol, monofluorotrichloromethane and dichlorodifluoromethane to steel.