US4640709A
Expired / Lapsed
US
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High concentration encapsulation by interfacial polycondensation
Assignee: Monsanto Co
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Filing: 1984-06-12
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Granted: 1987-02-03
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Expires: 2004-06-12
Abstract
Abstract This invention relates to a process for encapsulation, and particularly to the production of small or minute capsules constituted by a skin or thin wall of polymeric material e.g., polyurea, polyamide, polysulfonamide, polyester, polycarbonate, or polyurethane, which involves first providing an aqueous solution (continuous phase liquid) containing an emulsifier which is a water soluble, alkylated polyvinyl pyrrolidone polymer which will form a stable oil-in-water emulsion under the process conditions described herein. A discontinuous (immiscible or organic) phase liquid containing a water-immiscible material which is the material to be encapsulated, plus a first shell wall component; is dispersed in the aqueous liquid to form an oil-in-water emulsion. The second shell wall component is added to the oil-in-water emulsion whereupon the first shell wall component reacts with the second shell wall component to form a solid polycondensate shell wall about the material to be encapsulated. The capsules formed may be directly used as in the form of an aqueous suspension.
Inventors
- 👤 George B. Beestman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:34
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/16; A; A01; A01N; A01N25/00; A01N25/26; A01N25/28; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
124 words
A process of encapsulating water-immiscible material within a shell wall of polymeric material which comprises: (a) providing an aqueous phase containing an emulsifier which is an water-soluble alkylated polyvinyl pyrrolidone polymer which forms an oil-in-water emulsion; (b) dispersing in said aqueous phase a water-immiscible phase consisting essentially of a first shell wall component dissolved in said water-immiscible material, to form a dispersion of water-immiscible phase droplets throught the aqueous phase; (c) adding, with agitation, to said dispersion a second shell wall component whereby said second shell wall component reacts with said first shell wall component to form a polymeric shell wall about said water-immiscible material wherein the concentration of said water-immiscible material is from about 480 to about 700 grams per liter of composition.
Claim 2
Dependent Claim
124 words
A process of encapsulating water-immiscible material within a shell wall of polymeric material which comprises: (a) providing an aqueous phase containing an emulsifier which is an water-soluble alkylated polyvinyl pyrrolidone polymer which forms an oil-in-water emulsion; (b) dispersing in said aqueous phase a water-immiscible phase consisting essentially of a first shell wall component dissolved in said water-immiscible material, to form a dispersion of water-immiscible phase droplets throught the aqueous phase; (c) adding, with agitation, to said dispersion a second shell wall component whereby said second shell wall component reacts with said first shell wall component to form a polymeric shell wall about said water-immiscible material wherein the concentration of said water-immiscible material is from about 480 to about 700 grams per liter of composition.
Claim 3
Dependent Claim
27 words
A process according to claim 1 wherein said polymeric shell wall is selected from the group consisting of polyamide, polyurethane, polysulfonamide, polyurea, polyester, polycarbonate and mixtures thereof.
Claim 4
Dependent Claim
13 words
A process according to claim 1 wherein said polymeric shell wall is polyurea.
Claim 5
Dependent Claim
28 words
A process according to claim 3 wherein said first shell wall component is a polyisocyanate and wherein said second shell wall component is a difunctional or polyfunctional amine.
Claim 6
Dependent Claim
34 words
A process according to claim 3 wherein said first shell wall component is a diisocyanate and wherein said second shell wall component is a polyfunctional amine or a mixture of polyfunctional and difunctional amines.
Claim 7
Dependent Claim
47 words
A process according to claim 1 wherein said first shell wall component is a difunctional or polyfunctional reactant which is soluble in said water-immiscible material and which is capable of reacting with said second shell wall component to form a polymeric shell wall about said water-immiscible material.
Claim 8
Dependent Claim
38 words
A process according to claim 1 wherein said second shell wall component is a water soluble material which is capable of reacting with said first shell wall component to form a polymeric shell wall about said water-immiscible material.
Claim 9
Dependent Claim
70 words
A process according to claim 1 wherein the concentration of said emulsifier is from about 0.5% to about 15.0% by weight of said water-immiscible material, wherein the concentration of said first shell wall component is from about 3.5% to about 21.0% by weight of said water-immiscible material and wherein the concentration of said second shell wall component is from about 1.5% to about 9.0% by weight of said water-immiscible material.
Claim 10
Dependent Claim
46 words
A process according to claim 8 wherein the concentration of said water-immiscible material is from about 480 grams to about 600 grams per liter of composition and wherein the concentration of said emulsifier is from about 2.0% to about 4.0% by weight of said water-immiscible material.
Claim 11
Dependent Claim
33 words
A process according to claim 1 wherein the average particle size of the microcapsules produced by said process is in the range of from about 1 micron to about 50 microns in diameter.
Claim 12
Dependent Claim
188 words
A composition consisting essentially of microcapsules suspended in an aqueous liquid said microcapsules being comprised of a water-immiscible material contained within an encapsulating wall of polymeric material wherein: (a) the concentration of said water-immiscible material is from about 480 grams to about 700 grams per liter of composition; (b) wherein said encapsulating wall of polymeric material is the reaction product of a first shell wall component which is a difunctional or polyfunctional reactant that is soluble in said water-immiscible material and a second shell wall component which is water soluble and which is a difunctional or polyfunctional reactant and wherein the concentration of said first shell wall component is from about 3.5% to about 21.0% relative to the weight of said water-immiscible material and wherein the concentration of said second shell wall component is from about 1.5% to about 9.0% relative to the weight of said water-immiscible material; and (c) wherein said water contains from about 0.5% to about 15% of an emulsifier relative to the weight of said water-immiscible material, said emulsifier being an water-soluble alkylated polyvinyl pyrrolidone polymer which is capable of forming an oil-in-water emulsion.
Claim 13
Dependent Claim
188 words
A composition consisting essentially of microcapsules suspended in an aqueous liquid said microcapsules being comprised of a water-immiscible material contained within an encapsulating wall of polymeric material wherein: (a) the concentration of said water-immiscible material is from about 480 grams to about 700 grams per liter of composition; (b) wherein said encapsulating wall of polymeric material is the reaction product of a first shell wall component which is a difunctional or polyfunctional reactant that is soluble in said water-immiscible material and a second shell wall component which is water soluble and which is a difunctional or polyfunctional reactant and wherein the concentration of said first shell wall component is from about 3.5% to about 21.0% relative to the weight of said water-immiscible material and wherein the concentration of said second shell wall component is from about 1.5% to about 9.0% relative to the weight of said water-immiscible material; and (c) wherein said water contains from about 0.5% to about 15% of an emulsifier relative to the weight of said water-immiscible material, said emulsifier being an water-soluble alkylated polyvinyl pyrrolidone polymer which is capable of forming an oil-in-water emulsion.
Claim 14
Dependent Claim
14 words
A composition as described in claim 11 wherein said polymeric shell wall is polyurea.
Claim 15
Dependent Claim
97 words
A composition as described in claim 11 wherein the concentration of said water-immiscible material is from about 480 grams to about 600 grams per liter of composition, wherein the concentration of said first shell wall component is from about 5.0% to about 14.0% relative to the weight of said water-immiscible material, wherein the concentration of said second shell wall component is from about 2.0% to about 6.0% relative to the weight of said water-immiscible material, and wherein the concentration of said emulsifier is from about 2.0% to about 6.0% relative to the weight of said water-immiscible material.
Claim 16
Dependent Claim
65 words
A composition as described in claim 13 wherein the concentration of said first shell wall component is about 7.0% relative to the weight of said water-immiscible material, wherein the concentration of said second shell wall component is about 3.0% relative to the weight of said water-immiscible material and wherein the concentration of said emulsifier is about 2% relative to the weight of said water-immiscible material.
Claim 17
Dependent Claim
22 words
A composition as described in claim 11 wherein said water-immiscible material is an herbicide, insecticide, plant growth regulant or an herbicidal antidote.
Claim 18
Dependent Claim
23 words
A composition as described in claim 15 wherein said herbicide is selected from the group consisting of alachlor, butachlor, acetochlor, triallate and diallate.
Claim 19
Dependent Claim
30 words
A composition as described in claim 11 wherein the average particle size of the microcapsules is in the range of from about 1 micron to about 50 microns in diameter.
Claim 20
Dependent Claim
31 words
A composition as identified in claim 11 wherein said aqueous liquid additionally contains from about 0.01% to about 10% of a formulation adjuvant based on the weight of the total composition.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-02-02 | 1990-08-04 | 1991-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-02 | 1994-08-04 | 1995-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-02 | 1998-08-04 | 1999-02-03 | $7700.00 | Window Closed / Lapsed |