Patent ID: 7342065

Claim:
A process of preparing a nanocomposite comprised of an elastomer and at least partially exfoliated, intercalated water-swellable clay, which comprises (A) forming a first blend of water-swelled clay and anionic aqueous emulsion of elastomer particles by blending: (1) an aqueous mixture comprised of water and a multilayered water-swellable clay, exclusive of an intercalant for said clay, wherein said water-swellable clay is comprised of a plurality of stacked platelets with water-expanded galleries between said platelets, wherein said galleries contain naturally occurring cationic ion exchangeable ions therein, and (2) an anionic emulsion of synthetic elastomer particles as an aqueous pre-formed elastomer emulsion having a pH in a range of from about 6 to about 11 and exclusive of a thermoplastic polymer latex, comprised of said synthetic elastomer particles prepared by aqueous free radical induced polymerization of monomers in the presence of a free radical generating polymerization initiator and non-polymerizable anionic surfactant, wherein said synthetic elastomer particles are derived from an aqueous polymerization of monomers comprised of styrene and at least one of isoprene and 1,3-butadiene monomers or at least one of isoprene and 1,3-butadiene monomers or acrylonitrile and at least one of isoprene and 1,3-butadiene monomers, or (3) an anionic emulsion of natural cis 1,4-polyisoprene elastomer particles, and (B) blending with said first blend (1) an aqueous mixture comprised of water and amine having at least two amine centers selected from a cationic polymeric quaternary amine and ethylene polyamine, and optionally (2) an aqueous mixture comprised of water and inorganic acid having a pH in a range of about 3 to about 4; wherein said free radical polymerization initiator is an anionic aqueous polymerization initiator comprised of at least one of potassium peroxydisulfate and ammonium peroxydisulfate.