The present invention concerns microcapsules comprising a capsule core and a capsule wall, the capsule wall being constructed from 30% to 90% by weight of one or more C.sub.1-C.sub.24-alkyl esters of acrylic and/or methacrylic acid, acrylic acid, methacrylic acid and/or maleic acid (monomers I), 10% to 70% by weight of a mixture of divinyl and polyvinyl monomers (monomers II), the fraction of polyvinyl monomers being in the range from 2% to 90% by weight based on the monomers II, and also 0% to 30% by weight of one or more miscellaneous monomers (monomer III),all based on the total weight of the monomers, a process for their production and their use in textiles, bindered building materials and heat transfer fluids.