| 摘要 |
Microcapsules which are composed of a core and of a shell of a polymer, the core containing at least one oil which can be emulsified in water, and which are obtainable by polymerization of oil-soluble monomer mixtures which contain (a) 1-100% by weight of acrylic anhydride, methacryic anhydride, itaconic anhydride, citraconic anhydride, dimethylmaleic anhydride, 4-vinylbenzoic anhydride, mixed carboxylic anhydrides, mixtures of the said anhydrides and/or more than 40% by weight of maleic anhydride, (b) 0-99% by weight of at least one monoethylenically unsaturated monomer which is different from the monomers of group (a), (c) 0-80% by weight of crosslinking monomers which have at least two monoethylenically unsaturated non-conjugated double bonds in the molecule, and (d) 0-20% by weight of water-soluble monoethylenically unsaturated monomers in the oil phase of a stable oil-in-water emulsion in the presence of polymerization initiators which form free radicals, where the temperature of the polymerizing reaction mixture may be continuously or periodically increased during the polymerization, a process for producing the microcapsules by polymerization of the abovementioned monomer mixtures in the oil phase of a stable oil-in-water emulsion in the presence of polymerization initiators which form free radicals, where the temperature of the polymerizing reaction mixture may be continuously or periodically increased during the polymerization, and the use of the microcapsules for the controlled release of the core material of the microcapsules as active substance by destruction of their shell, in particular by the action of bases.
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