| abstract |
A process for the preparation of a dispersion of microcapsules, in which the microcapsules have a volume mean diameter d 50 of between 15 and 90 μm and a weight percentage of the shell of between 3 and 40%, with respect to the total weight of the capsules, wherein the microcapsule shell comprises at least one polyurea and the core comprises at least one lipophilic component, with the proviso that the core does not contain a fragrance, comprising the steps of: a) provision of a premix (I) comprising at least one protective colloid other than hydroxyalkyl cellulose in an aqueous solution, b) provision of a premix (II) comprising at least one polyisocyanate and at least one lipophilic component, c) the mixture of the premix (I) and the premix (II) until an emulsion (III) is formed, d) the addition of an aqueous solution (IV) containing at least one polyfunctional amine to the emulsion formed in step c) , e) the formation of a dispersion of microcapsules by heating the mixture obtained in step d) to a temperature of at least 50°C until microcapsules are formed, and f) adding hydroxyalkyl cellulose to the dispersion obtained in step e). |