US5185155A
Expired / Lapsed
US
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Encapsulating method and products containing encapsulated material
Assignee: Unilever Patent Holdings BV
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Filing: 1991-09-27
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Granted: 1993-02-09
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Expires: 2011-09-27
Abstract
Abstract An encapsulation process employs an aqueous dispersion of silica having a particle size not substantially greater than 100 nm. An emulsion is formed by high shear mixing of the silica dispersion with the material to be encapsulated and the emulsion is gelled. The process allows hydrophobic materials to be encapsulated in structures which have a high loading of the material and a good degree of imperviousness in the presence of other materials such as surfactants and mineral oils. Using the process, hydrophobic materials such as flavors, fragrances and cosmetic ingredients can be encapsulated for delayed release in a wide variety of products.
Inventors
- 👤 John M. Behan
- 👤 Jeremy N. Ness
- 👤 Keith D. Perring
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:59
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; A; A61; A61K; A61K8/00; A61K8/02; A61K8/11; A61K8/18; A61K8/19; A61K8/25; A61Q; A61Q19/00; B82; B82Y; B82Y5/00; A61K2800/00; A61K2800/40; A61K2800/41; A61K2800/412; A61K2800/413; A61Q11/00; A61Q13/00; A61Q17/00; A61Q17/04; A61Q5/00; A61Q5/02; A61Q5/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
95 words
A process for encapsulating a hydrophobic material to form capsules containing the hydrophobic material, comprising the steps of: producing an aqueous dispersion of silica the silica being in the form of particles substantially all of said particles having a particle size not greater than 100 nm; forming an emulsion of said dispersion and said hydrophobic material to be encapsulated by mixing, said dispersion and said hydrophobic material under high shear conditions; and stabilizing said emulsion containing the hydrophobic material by the addition of a gelling agent such that gelation occurs and capsules may be formed.
Claim 2
Dependent Claim
95 words
A process for encapsulating a hydrophobic material to form capsules containing the hydrophobic material, comprising the steps of: producing an aqueous dispersion of silica the silica being in the form of particles substantially all of said particles having a particle size not greater than 100 nm; forming an emulsion of said dispersion and said hydrophobic material to be encapsulated by mixing, said dispersion and said hydrophobic material under high shear conditions; and stabilizing said emulsion containing the hydrophobic material by the addition of a gelling agent such that gelation occurs and capsules may be formed.
Claim 3
Dependent Claim
37 words
A process according to claim 1 wherein the silica particles are in the form of colloidal silica or fumed silica having a side not substantially greater than 50 nm, and is preferably between 5 and 20 nm.
Claim 4
Dependent Claim
19 words
The process according to claim 1 wherein the weight ratio of encapsulated material to silica is at least 1.5:1.
Claim 5
Dependent Claim
19 words
The process according to claim 3 wherein the weight ratio of encapsulated material to silica is greater than 2:1.
Claim 6
Dependent Claim
34 words
The process according to claim 1 wherein the stabilizing step further comprises at least one of the steps of: (i) acidifying the emulsion; (ii) adding a salt; and (iii) adding a positively charged surfactant.
Claim 7
Dependent Claim
12 words
The process according to claim 1 further comprising: drying the gelled product.
Claim 8
Dependent Claim
19 words
The process according to claim 1 further comprising: adding a porosity-reducing material to the capsules to reduce their porosity.
Claim 9
Dependent Claim
24 words
The process according to claim 7 wherein a liquid-crystal-forming surfactant or starch or other polymer is the porosity-reducing material used for coating the capsules.
Claim 10
Dependent Claim
27 words
The process according to claim 1 wherein the stabilizing step further comprises the addition of a positively charged material that forms an outer coating on the capsules.
Claim 11
Dependent Claim
27 words
The process according to claim 9 wherein the positively charged material is selected from the group consisting of a positively charged polymer, a gum and a silicone.
Claim 12
Dependent Claim
31 words
The process according to any one of claims 7 to 10 wherein the material contained within the coating of the capsules forms at least 60% of the weight of the capsules.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-02-09 | 1996-08-10 | 1997-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-09 | 2000-08-10 | 2001-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-09 | 2004-08-10 | 2005-02-09 | $7700.00 | Window Closed / Lapsed |