Microcapsules

摘要

Microcapsule dispersion comprise alkyl esters of acrylic and/or methacrylic acid using a silicic acid dispersion with silicon dioxide particles of mean size 12 nm. The proportion of microcapsules of diameter≤4 microns is about 10%. Microcapsules including one or more lipophilic substances as core material and a polymer as the shell material, obtainable by radical polymerization of an oil-in-water emulsion comprise (wt.%): (a) one or more 1-24C alkyl esters of acrylic and/or methacrylic acid (30-100) (monomer I); (b) bi- or polyfunctional monomers (monomer II), which is insoluble or difficult to dissolve in water (0-80); (c) other monomers (0-40) (monomer III); (d) the lipophilic substance; and (e) inorganic solid particles of mean particle size 45-1000 nm. Independent claims are also included for: (1) a process for preparation of the microcapsules in which the above water-in-oil emulsion is polymerized and optionally spray dried; and (2) gypsum cardboard plates (sic) containing 5-40 wt.% of microcapsules.