Patent GB-562644-A (GB)
Title: New and improved moulding powders
IPC: C08K3/06
Filed: 1942-10-09
Abstract: Moulding powders yielding mouldings with high resistance to oils and solvents comprise essentially an interpolymer of an acrylic type compound and a 1.3-diene mixed with 1-10 per cent of its weight of elemental sulphur The interpolymer is formed from 1-8.5 per cent by weight of the 1.3.diene and 99-91.5 per cent of the acrylic compound. The 1.3.diene may be 1.3-butadiene, its mono-methyl derivatives, its chlorine substituted derivatives or their mono-methyl derivatives. The term acrylic type compound signifies acrylic acid, methacrylic acid and their derivatives such as methyl acrylate, methyl methacrylate, butyl methacrylate, stearylacrylate, methyl alpha-chloroacrylate, acrylic nitrile, methacrylic nitrile, acrylamide, methacrylamide, acrolein and alpha - chloroacrylonitrile. In example 1, 83.5 parts of methyl methacrylate and 4.4 parts of butadiene are dispersed in water with the aid of a mixture of dispersing agents containing respectively sodium cetyl sulphate and oleyl acetate.  The mixture is heated to about 50 DEG  C. with agitation in a closed vessel for 48 hours.  An antioxidant mixture of phenyl-alpha - naphthylamine and diphenylamine is added after release of any residual pressure, unreacted monomers are distilled off in steam and the polymer coagulated by addition of an electrolyte, e.g. aluminium sulphate solution.  The resulting powder is filtered, washed, dried and compounded by milling at 110 DEG  C. with mercaptobenzthiazole, stearic acid, zinc dibutyl dithiocarbamate, zinc oxide and sulphur.  The compounded stock may be moulded at 150 DEG  C. and 1000 pounds pressure.  The translucent cured product is still thermoplastic, swells in alcohol or benzene but does not disintegrate.  Other examples are given of moulding products prepared from the same monomers and other compounding ingredients mentioned are butoxyethyl phthalate, hexamethylene ammonium hexamethylene dithiocarbamate, piperidinium pentamethylene dithiocarbamate, ethyl thiuram disulphide, and zinc oxide. Example 4 describes the preparation of a moulding from an interpolymer prepared from 56 parts of acrylonitrile, 36 parts of methyl methacrylate and 8 parts of butadiene.  The polymeric material of the moulding powder is prepared by usual methods which may involve the use of catalysts, e.g. peroxides, persulphates, percarbonates and perborates, emulsifying agents such as sodium oleate, alkali metal salts of sulphonated hydrocarbons or of sulphated long-chain alcohols and protective colloids such as polyvinyl alcohol or alkali metal polymethacrylates. When the moulding powder contains a curing accelerator as well as sulphur, the total proportion of the two ingredients should not exceed 10 per cent.  Inert fillers such as carbon black, clay, calcium carbonate, and bentonite may be added to the moulding powder. Curing takes place at elevated temperature and pressure and may last for 2-20 minutes.  The powders may be used for a wide variety of articles, e.g. sheets, foils, fibres, wrapping and insulating material, handles, panels, rods and articles for ornamental costume jewellery.  Specifications 478,593 and 514,912 are referred to.ALSO:Moulding powders yielding mouldings with high resistance to oils and solvents comprise essentially an interpolymer of an acrylic type compound and a 1.3-diene mixed with 1-10 per cent of its weight of elemental sulphur.  The interpolymer is formed from 1-8.5 per cent by weight of the 1.3.diene and 99-91.5 per cent of the acrylic compound.  The 1.3.diene may be 1.3-butadiene, its mono-methyl derivatives, its chlorine substituted derivatives or the mono-methyl derivatives.  The term acrylic type compound signifies acrylic acid, methacrylic acid and their derivatives such as methyl acrylate, methyl methacrylate, butyl methacrylate, stearylacrylate, methyl alpha-chloroacrylate, acrylic nitrile, methacrylic nitrile, acrylamide, methacrylamide, acrolein and alpha-chloroacrylonitrile. In example 1, 83.5 parts of methyl methacrylate and 4.4 parts of butadiene are dispersed in water with the aid of a mixture of dispersing agents containing respectively sodium cetyl sulphate and oleyl acetate.  The mixture is heated to about 50 DEG  C. with agitation in a closed vessel for 48 hours.  An antioxidant mixture of phenylalpha-naphthylamine and diphenylamine is added after release of any residual pressure, unreacted monomers are distilled off in steam and the polymer coagulated by addition of an electrolyte, e.g. aluminium sulphate solution.  The resulting powder is filtered, washed, dried and compounded by milling at 110 DEG  C. with mercaptobenzthiazole, stearic acid, zinc dibutyl dithiocarbamate, zinc oxide and sulphur.  The compounded stock may be moulded at 150 DEG  C. and 1000 pounds pressure.  The translucent cured product is still thermoplastic, swells in alcohol or benzene but does not disintegrate.  Other examples are given of moulding products prepared from the same monomers and other compounding ingredients mentioned are butoxyethyl phthalate, hexamethylene ammonium hexamethylene dithiocarbamate, piperidinium pentamethylene dithiocarbamate, ethyl thiuram disulphide, and zinc oxide. Example 4 describes the preparation of a moulding from an interpolymer prepared from 56 parts of acrylonitrile, 36 parts of methyl methacrylate and 8 parts of butadiene.  The polymeric material of the moulding powder is prepared by usual methods which may involve the use of catalysts, e.g. peroxides, persulphates, percarbamates and perborates, emulsifying agents such as sodium oleate, alkali metal salts of sulphonated hydrocarbons or of sulphated long-chain alcohols and protective colloids such as polyvinyl alcohol or alkali metal polymethacrylates. When the moulding powder contains a curing accelerator as well as sulphur, the total proportion of the two ingredients should not exceed 10 per cent.  Inert fillers such as carbon black, clay, calcium carbonate, and bentonite may be added to the moulding powder. Curing takes place at elevated temperature and pressure may last for 2-20 minutes.  The powders may be used for a wide variety of articles, e.g. sheets, foils, fibres, wrapping and insulating material, handles, panels, rods and articles for ornamental costume jewellery.  Specifications 478,593 and 514,912 are referred to.