Production of polymer particles, e.g. useful as fillers, pigments or cosmetic ingredients, comprises polymerizing monomers in a water-in-oil-in-water emulsion

摘要

Production of polymer particles comprises preparing a water-in-oil-in-water emulsion in which the oil phase contains monomers and an amphiphilic block copolymer and/or a polyalkoxylated nonionic surfactant and the external aqueous phase contains a surfactant and/or amphiphilic polymer, and polymerizing the monomers. Production of polymer particles comprises: (a) preparing a water-in-oil-in-water emulsion in which the internal aqueous phase optionally contains at least one hydrophilic active ingredient, the oil phase comprises at least one principal monomer and/or at least one crosslinking monomer and optionally at least one comonomer and/or at least one polymerization initiator and at least one amphiphilic diblock polymer having a hydrophilic block and a hydrophobic block and/or an amphiphilic triblock polymer having terminal hydrophobic blocks and/or at least one polyalkoxylated nonionic surfactant, and the external aqueous phase contains at least one surfactant and/or at least one amphiphilic polymer; and (b) polymerizing the principal monomer(s) and/or crosslinking monomer(s) and optionally the comonomer(s) and/or initiator(s). An Independent claim is also included for polymer particles produced as above, where the surface of each particle is closed and the internal pores of each particle are not interconnected.