Nanocomposite of elastomer and dispersion therein of intercalated clay prepared in an aqueous medium with functional elastomer

A process of preparing a nanocomposite comprised of a functionalized diene-based elastomer and a 2:1 layered clay comprises blending:

• (A) an aqueous dispersion of a functionalized diene-based elastomer having a Tg in a range of about −120° C. to about +10° C. and a number average molecular weight in a range of about 1,000 to about 1,000,000 g/mole, wherein said elastomer is selected from copolymers of at least one of isoprene and 1,3-butadiene and copolymers of styrene or alpha methyl styrene with at least one of isoprene and 1,3-butadiene, and
• (B) a particulate 2:1 multi-layered swellable silicate clay;
• wherein:
• (1) said elastomer contains one or more functional groups selected from at least one of acid, acid-salt and acid-anhydride groups, wherein said aqueous dispersion has a pH in a range of from about 7.1 to about 14 and wherein said clay contains a non-polymeric salt of a quaternary ammonium ion in the galleries between its layers, or
• (2) said elastomer contains one or more functional groups as protonated amine modified epoxide groups, wherein said aqueous dispersion has a pH in a range of about 2.5 to about 6.9 and wherein said clay contains at least one cationically exchangeable ion in the galleries between its layers comprised of at least one of sodium, magnesium, potassium and calcium ions.