| 摘要 |
Process for encapsulating active principle particles by spraying a silicon thermoplastic copolymer in solution in an organic solvent or in dispersion or in aqueous emulsion and eliminating, by hot-air drying, the solvent or the water. The process for spraying/drying used is, for example, the Wurster method. The copolymer that can be used is formed by a sequence of segments or polydiorgano-siloxane blocks and segments or organic blocks including polyesters, polyethers, polyurethanes and polystyrenes. It can also be a polydiorganosiloxane grafted by organic chains. The active principle is in the form of size-graded particles comprised between 50 mu m and 5 mm. The active principle can be a catalyst, a perfume, a colouring agent, a cosmetic product, a drug, a phytosanitary product, vegetable seeds and the like. Application: in particular, for the controlled liberation of an active principle in an aqueous medium. |
