Patent GB-730765-A (GB)
Title: Improvements in or relating to rubber compositions
IPC: C08K3/36
Filed: 1953-10-05
Abstract: Rubber and silica compositions are obtained by first milling silica into a synthetic rubber or a mixture with natural rubber which contains no substantial concentration of polar ingredients, and then milling polar ingredients into the pretreated rubber. The silica is preferably that obtained by burning ethyl silicate or silicon tetrachloride in an atmosphere of oxygen, or by precipitating a metal silicate in aqueous medium with an acid. The synthetic rubber may be a polymer of butadiene-1,3,2-chlorobutadiene, or isoprene, or a copolymer of such a monomer with styrene, methyl methacrylate, acrylonitrile or methyl chloracrylate.  Amongst the polar ingredients which may be used are the usual vulcanization accelerators.  Polar accelerator activators which may be used include ethylene glycol, diethylene glycol, triethylene glycol and glycerine, ethylene diamine, monoethanol amine, triethanolamine, stearic acid, oleic acid, zinc oxide and lead oxide.  Softeners such as mineral oil, coumarone-indene resins, methyl acetyl ricinoleate, benzyl ricinoleate, castor oil, dibutyl tartrate and dioetyl phthalate; and antioxidants such as phenyl beta naphthylamine, diphenyl-p-phenylene diamine, and diorthotolylethylene diamine may also be present.  The products may be vulcanized.ALSO:Rubber and silica compositions are obtained by first milling silica into a natural or synthetic rubber or a mixture thereof which contains no substantial concentration of polar ingredients, and then milling polar ingredients into the pretreated rubber. The silica is preferably that obtained by burning ethyl silicate or silicon tetrachloride in an atmosphere of oxygen, or by precipitating a metal silicate in aqueous medium with an acid. The synthetic rubber may be a polymer of butadiene-1, 3, 2-chlorobutadiene, or isoprene or a copolymer of such a monomer with styrene, methyl metahcrylate, acrylonitrile or methyl chloracrylate. Preferred accelerators may be diorthotolyl guanidine, biphenyl guanidine, triphenyl guanidine, tetramethyl thiuram disulphide, tetramethyl thiuram monosulphide, tetrabutyl thiuram monosulphide, tetraethyl thiuram disulphide, tetramethyl thiuram tetrasulphide, dipentamethylene thiuram tetrasulphide, zinc dimethyl dithiocarbamate, zinc diethyl dithiocarbamate, copper diethyl dithiocarbamate, zinc dibutyl dithiocarbamate, zinc dibenzyl dithiocarbamate, selenium diethyl dithiocarbamate, benzothiazyl disulphide, 2- mercaptobenzothiazole, or its cupric salt, cyclohexyl - 2 - benzothiazyl sulphenamide, butyraldehyde-aniline heptaldehyde-aniline or zinc butyl xanthate.  Accelerator activators which may be used include ethylene glycol, diethylene glycol, triethylene glycol and glycerine; ethylene diamine, monoethanol amine, triethanolamine, stearic acid, oleic acid, zinc oxide and lead oxide.  Softeners such as mineral oil, coumarone-indene resins, methyl acetyl ricinoleate, benzyl ricinoleate, castor oil, dibutyl tartrate and dioctyl phthalate; and antioxidants such as phenyl beta naphthylamine, diphenyl-p-phenylene diamine, and diorthotolylethylene diamine.