GB887750A - Telomers of tetrafluoroethylene - Google Patents

Abstract

Dispersions of fluorowaxes having molecular weights in the range 1,300 to 2,000 are prepared by polymerizing one mole of tetrafluoroethylene in the presence of from 2,5 to 3 moles of trichlorotrifluoroethane and from 0,01 to 0,10 moles of an active telogens the polymerization being conducted with an organic peroxide catalyst at a temperature within the range 75 DEG C. to 200 DEG C., either at autogenous pressure in a closed system, or at 300 to 700 p.s.i.g. in a continuous system. Active telogens are defined as organic telogens which, on reaction with tetrafluoroethylene in the presence of a free radical catalyst but in the absence of any solvent or diluent, produce low molecular weight products containing predominantly one or two molecules of tetrafluoroethylene per molecule of telogen. Examples thereof are tertiary hydrocarbons, e.g. isobutane, methylcyclopropane, and methylcyclohexane; ethers with alpha hydrogen atoms, e.g. tetrahydrofuran, diethylether, and dioxane; amines, such as trimethylamine and triethylamine; dimethyl formamide; alcohols, e.g. methanol, ethanol, isopropanol, secondary butyl alcohol, and cyclohexanol; and bivalent sulphur compounds, e.g. ethylmercaptan and dimethyl disulphide. Suitable catalysts are benzoyl, ethyl and di-tertiary butyl peroxides. Either isomer of trichlorotrifluoroethane may be used, 1, 1, 2-trichloro-1, 2, 2-trifluoroethane being preferred. In examples methylcyclohexane or dimethylformamide are used as active telogens. Example V illustrates that when greater proportions of telogen than those specified are used greasy rather than waxy products are obtained. The waxy dispersion may be used directly as it is obtained from the process of preparation or converted to a paste or aerosol formulation. The products may be used as polishes, friction reducing compositions, mould release agents, dry lubricants and soil repellants. Numerous specific applications are mentioned typical of these being coatings of golf clubs, threads, dance floors, skittle alleys, shovels, irons, playing cards, windows, and tyres; the waterproofing of paper, textiles, wood, and painted surfaces; and the lubrication of locks, fishing rods, cameras and lace-making machinery.ALSO:Dispersions of fluorowaxes having molecular weights in the range 1,300 to 2,000 are prepared by polymerizing one mole of tetrafluoroethylene in the presence of from 2,5 to 3 moles of trichlorotrifluoroethane and from 0,01 to 0,10 moles of an active telogen, the polymerization being conducted with an organic peroxide catalyst at a temperature within the range 75 DEG C. to 200 DEG C., either at autogenous pressure in a closed system, or at 300 to 700 p.s.i.g. in a continuous system. Active telogens are defined as organic telogens which, on reaction with tetrafluoroethylene in the presence of a free radical catalyst but in the absence of any solvent or diluent, produce low molecular weight products containing predominantly one or two molecules of tetrafluoroethylene per molecule of telogen. Examples thereof are tertiary hydrocarbons, e.g. isobutane, methylcyclopropane, and methylcyclohexane; ethers with alpha hydrogen atoms, e.g. tetrahydrofuran, diethylether, and dioxane; amines, such as trimethylamine and triethylamine; dimethyl formamide; alcohols, e.g. methanol, ethanol, isopropanol, secondary butyl alcohol, and cyclohexanol; and bivalent sulphur compounds, e.g. ethylmercaptan and dimethyl disulphide. Suitable catalysts are benzoyl, ethyl and di-tertiary-butyl peroxides. Either isomer of trichlorotrifluoroethane may be used, 1,1,2-trichloro -1,2,2,-trifluoroethane being preferred. In examples methylcyclohexane or dimethyl formamide are used as active telogens. Example V illustrates that when greater proportions of telogen than those specified are used greasy rather than waxy products are obtained. The waxy dispersion may be used directly as it is obtained from the process of preparation or converted to a paste or aerosol formulation. The products may be used as polishes, friction-reducing compositions, mould release agents, dry lubricants and soil repellents. Numerous specific applications are mentioned, typical of these being coatings on golf clubs, threads, dance floors, skittle alleys, shovels, irons, playing cards, windows, and tyres; the waterproofing of paper, textiles, wood, and painted surfaces; and the lubrication of locks, fishing rods, cameras and lace-making machinery.