GB732817A - Weighted ion exchange resin granulars and method of making same - Google Patents

Abstract

Weighted resin granules are obtained by treating a finely-divided solid having an absolute density of at least 2.5 and a particle size of not greater than 80 mesh, and which is water-wettable and insoluble in and chemically inert to vinyl aromatic compounds and their polymers, with a hydrophobing agent, and admixing 5 to 53 parts by volume with 47 to 97 parts of a major proportion by weight of at least one mono-alkenyl aromatic hydrocarbon having a vinyl or isopropenyl radical attached to the aromatic nucleus, e.g. styrene, a -methyl styrene, ar-vinyl toluene, ar-vinyl xylene or ar-ethylvinyl benzene, and a minor proportion of divinyl benzene, agitating the mixture with a larger volume of non-solvent liquid which has a viscosity of 20-250 centipoises at 80 DEG C., e.g. glycerine, polyethylene glycols or aqueous solutions thereof, or water or aqueous salt solution thickened with agents such as methyl cellulose or sodium or potassium salts of carboxymethyl celluiose to form droplets and heating to cause polymerization and solidification. Catalysts such as dibenzoyl or dilauroyl peroxide may be used. The solids mentioned are sand, powdered silica, powdered glass, powdered iron, nickel, chromium or molybdenum, monazite sand, zirconium oxide and zirconium silicate, treated with dodecylamine, n - octadecylamine, dimethyl dichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, ethyltriethoxysilane, dimethylsiloxane, methylphenylsiloxane. The granules are then sulphonated to form cation exchange resins or chloromethylated and reacted with ammonia or amines to form anion-exchange resins. Examples describe the preparation of granules of a styrene, ar-ethyl vinylbenzene, and divinylbenzene copolymer weighted with zircon sand, which are then sulphonated or animated.