US5130171A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for encapsulating particles with a silicone
Assignee: Rhone Poulenc Sante SA
•
Filing: 1989-12-21
•
Granted: 1992-07-14
•
Expires: 2009-12-21
Abstract
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.
Inventors
- 👤 Christian Prud'Homme
- 👤 Hugues Porte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:58
CPC Classifications
A; A01; A01C; A01C1/00; A01C1/06; A01N; A01N25/00; A01N25/26; A61; A61K; A61K9/00; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1652; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5031; B; B01; B01J; B01J13/00; B01J13/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
A process for encapsulating particles of an active substance having a particle size of between 50 μm and 5 mm, which comprises film-coating each particle with a thermoplastic linear silicone polymer, by spraying onto each particle said thermoplastic linear silicone copolymer in a solution of an organic solvent or in an aqueous emulsion or disperson, and evaporating said solvent and/or water to form an encapsulated particle having a zero order of release, said thermoplastic linear silicone copolymer softens when heated, is soluble in volatile organic solvents and/or emulsifiable or dispersible in water and is a linear multiblock copolymer, a block copolymer or a graft copolymer, whose substantially linear main polymer chain consists either of an alternation of polydiorganosiloxane segments or blocks and of organic segments or blocks, or of a polydiorganosiloxane chain onto which organic chains are grafted.
Claim 2
Dependent Claim
138 words
A process for encapsulating particles of an active substance having a particle size of between 50 μm and 5 mm, which comprises film-coating each particle with a thermoplastic linear silicone polymer, by spraying onto each particle said thermoplastic linear silicone copolymer in a solution of an organic solvent or in an aqueous emulsion or disperson, and evaporating said solvent and/or water to form an encapsulated particle having a zero order of release, said thermoplastic linear silicone copolymer softens when heated, is soluble in volatile organic solvents and/or emulsifiable or dispersible in water and is a linear multiblock copolymer, a block copolymer or a graft copolymer, whose substantially linear main polymer chain consists either of an alternation of polydiorganosiloxane segments or blocks and of organic segments or blocks, or of a polydiorganosiloxane chain onto which organic chains are grafted.
Claim 3
Dependent Claim
34 words
Process according to claim 1, wherein the segments, blocks or grafts of the thermoplastic linear silicone copolymer are selected from the group consisting of polyurethanes, polyarylenes, polystyrenes, polyesters, polyethers, polycarbonates, polyamides, polyimides and polyimides/amides.
Claim 4
Dependent Claim
21 words
Process according to claim 2, wherein the weight content of the organic segments, blocks or grafts is between 5 and 60%.
Claim 5
Dependent Claim
22 words
Process according to claim 1, wherein the thermoplastic silicone copolymer has a glass transition temperature or a melting temperature above 40° C.
Claim 6
Dependent Claim
18 words
Process according to claim 1, wherein the said active substance is an alimentary, plant-protection or medicinal active substance.
Claim 7
Dependent Claim
19 words
Process according to claim 5, wherein the said active substance is an antiinflammatory agent, hormone, antibacterial or antitumoral agent.
Claim 8
Dependent Claim
16 words
Process according to claim 1, wherein the said active substance is a plant seed or embryo.
References Cited (Backward Citations)
US3141792A
Cited
US3247066A
Cited
US3832252A
Cited
US4230686A
Cited
US3943063A
Cited
US3911183A
Cited
US3921636A
Cited
US4851216A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-14 | 1996-01-13 | 1996-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-14 | 2000-01-13 | 2000-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-14 | 2004-01-13 | 2004-07-14 | $7700.00 | Window Closed / Lapsed |