Process for encapsulating particles with a silicone
US5130171A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1989 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Dec 21, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J13/02
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Particles of active substance are encapsulated by spraying them with a thermoplastic silicone copolymer in solution in an organic solvent or in an aqueous dispersion or emulsion and removing the solvent or water by drying with hot air. The spraying/drying process employed is, for example, the Wurster process. The copolymer employed can be made up of a succession of polydiorganosiloxane segments or blocks and of organic segments or blocks (polyesters, polyethers, polyurethanes, polystyrenes, and the like). It can also be a polydiorganosiloxane grafted with organic chains. The active substance is in the form of particles with a particle size of between 50 .mu.m and 5 mm. It may be a catalyst, a perfume, a colorant, a cosmetic product, a medication, a plant-protection product, plant seeds, and the like. The invention is especially useful for controlling the release of active substance in an aqueous medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.