GB878561A - Aqueous polymer dispersions - Google Patents

Abstract

Aqueous dispersions of a gelatinous polymeric reaction product derived from an unsaturated aliphatic compound obtained using a catalyst consisting of a mixture of a compound of a heavy metal selected from Group IVa, Va, VIa, VIIa, or VIII of the Periodic Table and an organo-metallic compound of a metal selected from Group I, II, IIIb, or IVb of the Periodic Table, are made by incorporating in the polymeric reaction product an organic acid capable of forming a water-soluble soap, and converting the acid into a water-soluble soap and agitating the composition with water. The organic acid is generally added directly to the polymer suspended in the medium in which it is prepared and the organic acid functions as a metallic catalyst residue remover. The medium in which the polymerization is effected is generally an aliphatic or mononuclear aromatic hydrocarbon. The catalyst used in the polymerization may be adsorbed on cryolite, or silica, or carbon black. The organic acid may be oleic acid, linoleic acid, linolenic acid, capric, lauric, palmitic or stearic acid, or rosin acids such as dehydroabietic acid, 7, 8-dihydroabietic acid, tetrahydroabietic acid, dextropimaric acid, or dihydrodextropimaric acid. The acid is converted into a water-soluble soap by the addition of bases such as the hydroxides of ammonium and the alkali metals. The polymeric material may be obtained by the polymerization of butadiene, isoprene, propylene, butene-1, ethylene, and mixtures thereof. In Example (1), liquid butadiene is polymerized in heptane in the presence of aluminium triisobutyl and titanium tetrachloride, and an aqueous dispersion formed by adding oleic acid to the polymerizate followed by sodium hydroxide, and then water; in Example (2), polyisoprene made by the same process as polybutadiene in Example (1), but using benzene as the polymerization medium is formed into an aqueous dispersion by adding to the medium, with stirring, lauric acid, sodium hydroxide, and water; whilst in Example (3) a copolymer of ethylene and propylene is made by polymerizing a mixture of the monomers in petroleum ether in the presence of vanadium tetrachloride and aluminium triisobutyl, and an aqueous dispersion formed by adding to the medium, with vigorous stirring, lauric acid, sodium hydroxide, and water. The polymeric materials may be isolated from the aqueous dispersions by conventional synthetic rubber latex techniques.