Patent GB-944738-A (GB)
Title: Preparation of inorganic colloidal sols in hydrocarbon media
IPC: C09K23/00
Filed: 1961-10-11
Abstract: A process for the preparation of a colloidal dispersion of an inorganic substance in a liquid hydrocarbon comprises preparing a colloidal dispersion of said substance in water, an alcohol having 1 to 3 carbon atoms, or mixtures thereof, by reaction of solutions of reagents in said polar medium, thereafter mixing said colloidal dispersion with agitation with a liquid hydrocarbon containing a surfactant, and simultaneously or thereafter removing the polar medium from the mixture.  The dispersion in the polar medium may be formed in the presence of protective colloids, those specified being galatin, albumin, gum tragacanth, lignin sulphonates, polyvinyl alcohols, glycerol, low molecular weight mono- and diglycerides, ethylene glycol, and ethylene oxide condensates. Surfactants specified are metal aryl alkyl sulphonates, metal alkyl sulphates, hydrocarbon sulphonic acids, phosphosulphurized hydrocarbons, phosphate esters of high molecular weight alcohols, for example those prepared by reaction of phosphorus pentoxide with the oxo-alcohols, high molecular weight saturated and unsaturated fatty acids and their metal salts, high molecular weight amines, and various copolymers, for example alkyl fumarates-vinyl acetate - maleic anhydride, mixed C4-C18 methyl methacrylates-N-vinyl pyrrolidone, and mixed C9-C12 fumarates-vinyl acetate-N-vinyl pyrrolidone copolymers.  The polar medium may be removed by adding the polar dispersion to the hydrocarbon heated to a temperature sufficient to evaporate said polar medium, or by adding the hydrocarbon to the polar dispersion to form on emulsion therewith, breaking the emulsion, for example by heating or addition of hexane or heptane, and separating the polar phase.  Specific examples relate to formation of (1) calcium carbonate dispersions from calcium chloride and sodium carbonate in aqueous solution, (2) lead dispersions from methanolic lead acetate trihydrate and ammonia in methanolic solutions, and (3) mercury dispersions from mercuric oxide in acetic acid solution and aqueous ammonia.ALSO:Colloidal dispersions of inorganic substances in hydrocarbons containing a surfactant (for preparation thereof see Division C1) are used as additions for fuel oils and mineral lubricating oils. Inorganic substances exemplified are calcium carbonate, lead acetate trihydrate treated with ammonia, and mercuric oxide. Surfactants specified are metal aryl alkyl sulphonates, metal alkyl sulphates, hydrocarbon sulphonic acids, phosphosulphurized hydrocarbons, phosphate esters of oil dispersible alcohols, e.g. the oxo-alcohols, multifunctional polymers, e.g. vinyl acetate-alkyl fumarate-maleic anhydride copolymers and unsaturated ester N - vinyl - pyrrolidone copolymers, oil dispersible saturated and unsaturated fatty acids and their metal salts, and oil-dispersible amines. The inorganic substance may have been precipitated in the presence of a protective colloid, for example gelatine, albumin, gums, e.g. gum tragacanth, lignin sulphonates, polyvinyl alcohols, glycerol, low molecular weight mono- and di-glycerides, ethylene glycol and ethylene oxide condensates.