Patent ID: 6051614
Filing Date: 2000-04-18
Classification: B01J,H01B

Abstract:
A method for preparing a non-aqueous liquid dispersion of particles of at least one member selected from the group consisting of a metal and a metal compound, which comprises:(a) providing an aqueous dispersion of particles of at least one member selected from the group consisting of a metal and a metal compound, said metal being at least one member selected from the group consisting of gold, silver, platinum, rhodium, palladium, ruthenium, iridium and osmium, said metal compound being at least one member selected from the group consisting of metal borides, metal sulfides, metal hydroxides and metal oxides, wherein said metal species of said metal compound is at least one member selected from the group consisting of iron, nickel, cobalt, cadmium, copper, barium, aluminum, indium, tin, titanium, tantalum, silicon and zirconium;(b) contacting said aqueous dispersion and a surfactant, said surfactant being at least one member selected from the group consisting of an alkali metal salt of a fatty acid, a higher alcohol sulfate ester, an alkali metal salt of an alkylbenzenesulfonic acid, an alkyl chain-containing primary amine salt, an alkyl chain-containing secondary amine salt, an alkyl chain-containing tertiary amine salt, an alkyl chain-containing quaternary ammonium salt, an alkyl chain-containing pyridinium salt, an ester of a polyhydric alcohol with a fatty acid, an ethylene oxide polymerization adduct, a sulfobetaine type surfactant, a betaine type surfactant, an amino acid type surfactant, a quaternary ammonium salt having at least two long alkyl chains, and an adduct of a sulfonic acid group to a diester of succinic acid with a higher alcohol, said surfactant being used in an amount of from 0.001 to 2% by weight, based on the weight of water of said aqueous dispersion,with a water-immiscible, non-aqueous liquid in the presence or absence of at least one salt selected from the group consisting of a water-soluble inorganic acid salt and a water-soluble organic acid salt exhibiting substantially no surface activity, said at least one salt being selected from the group consisting of sulfates, halides, acetates, nitrates, carbonates, citrates and tartrates of ammonium, lithium, sodium, potassium, magnesium, calcium, strontium, barium, aluminum and lanthanum, said at least one salt being used in an amount of from 0.005 to 30% by weight, based on the weight of water of said aqueous dispersion,and wherein when the contacting of said aqueous dispersion with said non-aqueous liquid is conducted in the absence of said at least one salt, said at least one salt is added after said contacting,thereby causing said particles to migrate from said aqueous dispersion into said non-aqueous liquid to obtain a two-phase system comprised of a non-aqueous dispersion phase comprising said non-aqueous liquid having said particles dispersed therein and an aqueous phase substantially free of said particles; and(c) isolating said non-aqueous dispersion phase from said two-phase mixture.