Patent GB-746880-A (GB)
Title: Improvements in or relating to heteropolymeric resins
IPC: C08F36/04
Filed: 1953-12-10
Abstract: Sulphur dioxide is heteropolymerized, in the presence of an emulsifier effective in acid media, with a polymer present in a latex formed by aqueous emulsion polymerization of a conjugated diene or a substitution product thereof having at least one phenyl, furyl, alkyl, cyano, cyanate, isocyanate, thiocyanate, isothiocyanate or alkoxy group.  Dienes specified are butadiene, isoprene, piperylene; 2,3-dimethyl-, 3-furyl-, 3-methoxy-, 1,4-dicyano-, 1,4-diisothiocyano-, 1-acetoxy-, 2,3-diphenyl- and 1,4-diisooxy - cyano - butadienes; 1 - thiocyano 2,4 - pentadiene and 1,3 - dioxycyano - 2,4 - hexadiene, and mixtures thereof.  One or more monomers may be copolymerized with the diene and listed are styrene; alkyl-, p-chloro-, p-methoxy- and a -methyl-styrenes; vinyl naphthalene, acrylic and methacrylic acids, methyl and ethyl acrylates, methyl a -chloroacrylate, methyl, ethyl and butyl methacrylates, methyl ethacrylate, acrylonitrile, methacrylonitrile, methacrylamide, methyl isopropenyl and methyl vinyl ketones, methyl vinyl ether, vinylethinyl alkyl carbinols, vinyl acetate, vinyl and vinylidine chlorides, vinylfurane, -carbazole and-acetylene, vinyl pyridines and substituted vinyl pyridines such as 2-methyl-5-vinyl pyridine.  Emulsifiers specified for the preparation of the copolymers and heteropolymers are non-ionic emulsifiers, alkyl amine hydrochlorides, e.g. cetyl pyridinium chloride, and salts of alkyl aromatic sulphonic and long-chain alkyl sulphuric acids, e.g. sodium alkyl benzene sulphonate.  Fatty acid and rosin acid soaps may be used for the preparation of the copolymer but an emulsifier effective in acid medium must be added to the latex prior to the sulphur dioxide.  The heteropolymerization may take place in the dark or light and in the presence of a catalyst.  Coagulation of the heteropolymer may be effected with methanol, isopropyl alcohol, brines or polyvalent metal salts.  Heteropolymers of sulphur dioxide with copolymers of butadienes and vinyl pyridines may be further modified by reaction with quaternizing compounds such as methyl ptoluenesulphonate, butyl benzene sulphonate; methyl, diethyl and dilauryl sulphates; methyl iodide, ethyl bromide, benzyl and benzal chlorides, hexachloropentadiene and halogenated wax.  The products of quaternization have utility as fungicides, insecticides, bactericides, as paint constituents, as oil resistant rubbers and as plastics.  Catalysts used in producing the diene polymer latices include redox systems such as hydroperoxide, sugar (e.g. dextrose), potassium pyrophosphate and ferrous sulphate.  Potassium persulphate and a wide variety of diazothioethers, hydroperoxides and polyalkylene polyamines may also be used as catalysts.  The diazothioethers may be added incrementally and may also function as modifiers in which case they are desirably used with potassium or sodium ferricyanide. The polyalkylene polyamines appear to act as reductants and/or activators and may be used alone.  With a hydroperoxide, or its salt, optimum polymerization occurs at 0.1 to 10 millimoles per 100 parts of monomer.  As polymerization modifiers, alkyl mercaptans may be included, e.g. C8 to C16 compounds, in up to 20 parts per 100 of monomers in order to give a liquid polymer for subsequent reaction with the sulphur dioxide. Inorganic salts, such as potassium chloride; alcohols, such as methyl alcohol, ethylene glycol, glycerine and erythritol, and potassium hydroxide may be included in the emulsion polymerization recipe, which is preferably maintained at a pH of 8.5 to 12. Conversion is preferably carried out to completion.  Examples describe the curing with the usual ingredients of polybutadiene/sulphur dioxide heteropolymers containing titanium dioxide, zinc oxide, oil, litharge and hydrogenated rosin. Example II describes short-stopping the polymerization of butadiene with dinitrochlorobenzene and 2,2-methylene-bis-(4-methyl-6-t.-butylphenol).  The heteropolymeric reaction products are useful as constituents of paints and latex paints, as softeners for synthetic rubbers, as fillers for plastics, as rocket fuel constituents, as moulding resins and rubbers and in producing textile fibres and filaments.