| 摘要 |
Aqueous polymer dispersions comprising effect substance and having an average particle diameter of the dispersed particles of <500 nm, where the polymer particles comprise a polymer matrix constructed from at least one ethylenically unsaturated monomer as core, on the surface of which is arranged at least partially an effect substance which is soluble in the monomers which form the polymer matrix of the particles, methods for producing such polymer dispersions by miniemulsion polymerization of ethylenically unsaturated monomers, wherein a miniemulsion with an average particle size of the emulsified particles of <500 nm is prepared by emulsifying ethylenically unsaturated monomers in water in the presence of at least one effect substance and a surface-active agent, and it is polymerized in such a way in the presence of at least one free-radical polymerization initiator that initially only at most 50% of the monomers which are situated in the polymerization zone polymerize and where the effect substances migrate to the surface of the emulsified particles, and the polymerization is complete only after extensive or complete accumulation of the effect substances on the surface of the resulting polymer particles, and use of the dispersions or the powders obtainable therefrom by evaporating off water for stabilizing polymers against the effect of UV radiation, oxygen and heat, in cosmetic and pharmaceutical formulations, in paint coats, during the production of paper, leather or textiles and in formulations for animal nutrition. |
