Aqueous polymer nanocomposite dispersion, useful e.g. in coating composition, particularly protective coating composition e.g. as varnishes, comprises polymerized product of monomers and an aqueous dispersion of silica nanoparticles

摘要

Aqueous polymer nanocomposite dispersion comprises polymerized product of monomers and an aqueous dispersion of silica nanoparticles, in an emulsion form. The monomers are added in to a reactor containing the nanoparticle dispersion. The aqueous dispersion e.g. does not contain cationic organic compound like monomers, dispersants or primers that work as a stabilizer for the dispersed silica, is stable at a pH of 2-10 and does not form aggregates, agglomerates and/or sedimentation. Aqueous polymer nanocomposite dispersion comprises polymerized product of monomers and an aqueous dispersion of silica nanoparticles, in an emulsion form. The monomers are added into a reactor containing the nanoparticles dispersion. The aqueous dispersion does not contain cationic organic compound like monomers, dispersants or primers that work as a stabilizer for the dispersed silica, is stable at a pH of 2-10, does not form aggregate, agglomerate and/or sedimentation and contains aluminum modified anionic nanoparticles of 5-50 nm in size. The polymerization is carried out in the presence of an organic primer system i.e. free of all ionic groups. Independent claims are included for: (1) a process of preparing the dispersion comprising adding the anionic silica nanoparticle dispersion in to a polymerization reactor, (semi-continuously) adding the monomers to form a reaction mixture, and polymerizing the reaction mixture in the presence of the organic primer system; and (2) a coating composition comprising the dispersion.