Microcapsules comprising one or more lipophilic substances as core material and a polymer as capsule shell, which are obtainable by free-radical polymerization of an oil-in-water emulsion comprising from 30 to 100% by weight, based on the total weight of the monomers, of one or more C1-C24-alkyl esters of acrylic and/or methacrylic acid (monomer I), from 0 to 80% by weight, based on the total weight of the monomers, of a bifunctional or polyfunctional monomer (monomers II) which is insoluble or sparingly soluble in water and from 0 to 40% by weight, based on the total weight of the monomers, of other monomers (monomers III), the lipophilic substance and solid inorganic particles having a mean particle size of from 45 to 1000 nm, and a process for producing them are described. They can be used in binding building materials, textiles and gypsum plasterboard.