Patent GB-667649-A (GB)
Title: Foam inhibiting compositions
IPC: D06P1/52
Filed: 1950-04-17
Abstract: A foam-inhibiting composition is prepared by mixing a solid, granular to pulverulent, water-soluble carrier with a liquid mixture of a normally gelatinous to viscous hydrocarbon siloxane polymer and a liquefying diluent, the amount of the polymer not exceeding 5 per cent of the carrier and the mixture being saturated with, or being a non-solvent for, the carrier so as to maintain the latter in solid form.  Specified carriers are sodium sulphate, sodium chloride, potassium chloride, ammonium sulphate, cane sugar, dextrin, maltose, sodium acetate, sodium benzene sulphonate and water-soluble dyes or dye intermediates.  The siloxane polymer, e.g. polymeric dimethyl siloxane, may be applied to the carrier as a solution in a volatile diluent such as carbon tetrachloride, benzene, toluene, ethyl ether or ethanol, the diluent being subsequently evaporated.  Alternatively the polymer may be mixed with a water-soluble nonvolatile liquifying diluent such as a surfaceactive agent, e.g. monoesters or ethers of polyalkylene glycols, for application to the carrier.  As a further alternative a colloidal dispersion or solution of the polymer in a solution, preferably an aqueous solution, of a surface-active agent, e.g. organic sulphates, sulphonates and carboxylates which contain a high alkyl chain, may be applied to the carrier.  The carrier may be added to or formed in an aqueous dispersion of the polymer and the solid mixture separated by filtration; thus a dyestuff or dye forming component, acting as carrier, may be salted out or precipitated from an aqueous solution containing a dispersion of the polymer.  Numerous examples are given.ALSO:A foam inhibiting composition for use in aqueous systems is prepared by mixing a solid, granular to pulverulent, water-soluble carrier with a liquid mixture of a normally gelatinous to viscous hydrocarbon siloxane polymer and a liquefying diluent, the amount of the polymer not exceeding 5 per cent of the carrier and the mixture being saturated with a monsolvent for the carrier so as to maintain the latter in solid form. Specified carriers are water-soluble inorganic salts such as sodium sulphate, sodium chloride, potassium chloride or ammonium sulphate; water-soluble organic substances such as cane sugar, dextrin, maltose, sodium acetate or sodium benzene sulphonate and water-soluble dyestuffs or dyestuff intermediates.  The siloxane polymer, e.g. polymeric dimethyl siloxane may be applied to the carrier as a solution in a volatile diluent such as carbon tetrachloride, benzene, toluene, ethyl ether or ethanol, the diluent being subsequently evaporated. Alternatively, the siloxane polymer may be mixed with a water-soluble non-volatile liquifying diluent such as a surface active agent, e.g. monoesters or ethers of polyalkylene glycols, for application to the carrier.  As a further alternative a colloidal dispersion or solution of the polymer in a solution, preferably an aqueous solution, of a surface active agent, e.g. organic sulphates, sulphonates and carboxylates which contain a high alkyl chain, may be applied to the carrier.  The carrier may be added to or formed in an aqueous dispersion of the polymer and the solid mixture separated by filtration; thus a dyestuff or dye-forming component, acting as carrier, may be salted out or precipitated from an aqueous solution containing a dispersion of the polymer.  Numerous examples are given.