| abstract |
The present invention relates to a process for producing microparticles laden with at least one active, wherein the microparticles are formed from a thermoplastic organic, polymeric material and in the unladen state, in their interior, have at least one cavity connected via pores to the surface of the microparticles, wherein (a) a composition of unladen microparticles are impregnated with a liquid comprising the active, whereby laden microparticles are obtained, which contain in the interior cavity the liquid, and (b) subjecting the laden microparticles to thermal treatment by passing a stream of free flowing laden microparticles in a carrier gas through a heated zone at a temperature of at least 20 K, in particular at least 40 K, e.g. 20 to 250 K especially 40 to 200 K above the softening temperature of the thermoplastic organic polymeric material, where the average residence time of the laden microparticles in the heated zone is not more than 60 s, in particular not more than 30 s, especially not more than 20 s or not more than 10 s, e.g. in the range of 0.1 to 60 s, in particular in the range of 0.1 to 30 s, more particularly in the range of 0.5 to 20 s and especially in the range of 1 to 10 s. The present invention further relates to compositions of microparticles filled with at least one active, in particular with at least volatile organic active, which is obtainable by a process of the invention, and to the use thereof, especially in a product selected from perfumes, washing and cleaning compositions, cosmetic compositions, personal care compositions, hygiene articles, foods, food supplements, fragrance dispensers and fragrances. The present invention further relates to products comprising an inventive composition of microparticles filled with at least one active, in particular with at least one volatile organic active, and to the use thereof, especially for controlled release of actives of low molecular weight and specifically for controlled release of aroma chemicals. |