Patent US4670250A successfully refreshed from Google Patents.
US4670250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Durable controlled release microcapsules
Assignee: Bend Research Inc
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Filing: 1983-10-21
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Granted: 1987-06-02
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Expires: 2003-10-21
Abstract
Abstract Impact-resistant microcapsules for the sustained and controlled release of biologically active ingredients through a surrounding permeable polymeric wall are disclosed wherein the ratio by weight of active ingredient to polymer is from about 4:1 to about 1:4, the polymeric walls having high tensile yield and tensile impact strengths and low nitrogen permeabilities.
Inventors
- 👤 Richard W. Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:07
CPC Classifications
A; A01; A01N; A01N25/00; A01N25/26; A01N25/28; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5031; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/12; B01J13/125
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
88 words
A controlled release microcapsule comprising a core of active ingredient and a permeable polymer surrounding said core, (a) the active ingredient being biologically active, (b) the permeable polymer being thermoplastic and soluble in a common organic solvent, having a tensile yield strength of more than 9,000 lb/in 2 , a tensile impact strength of more than 70 ft-lb/in 2 , and a nitrogen permeability of less than 10 -10 cm 3 -cm/cm 2 -sec-cmHg, and (c) having a core-to-polymer ratio from about 4:1 to about 1:4 by weight.
Claim 2
Dependent Claim
88 words
A controlled release microcapsule comprising a core of active ingredient and a permeable polymer surrounding said core, (a) the active ingredient being biologically active, (b) the permeable polymer being thermoplastic and soluble in a common organic solvent, having a tensile yield strength of more than 9,000 lb/in 2 , a tensile impact strength of more than 70 ft-lb/in 2 , and a nitrogen permeability of less than 10 -10 cm 3 -cm/cm 2 -sec-cmHg, and (c) having a core-to-polymer ratio from about 4:1 to about 1:4 by weight.
Claim 3
Dependent Claim
48 words
The microcapsule of claim 1 wherein the polymer is selected from polysulfones, polyether sulfones, polyaryl sulfones, polycarbonates, polymethylmethacrylates, poly(styrene-acrylonitriles), polystyrenes, acrylonitrilebutadiene-styrene polymers, polyacrylonitriles, polyvinyl fluorides, polyvinylidene fluorides, polyvinyl chlorides, polyvinylidene chlorides, polyethyleneterephthalates, polybutyleneterephthalates, polyamides, polyamideimides, polyimides, polyacetals, cellulose esters, polyurethanes, polyarylates, polyaryl ethers, and derivatives or copolymers thereof.
Claim 4
Dependent Claim
17 words
The microcapsule of claim 1 wherein the polymer is selected from polysulfones, polyether sulfones and polyaryl sulfones.
Claim 5
Dependent Claim
11 words
The microcapsule of claim 1 wherein the polymer is a polycarbonate.
Claim 6
Dependent Claim
11 words
The microcapsule of claim 1 wherein the polymer is a polymethylmethacrylate.
Claim 7
Dependent Claim
11 words
The microcapsule of claim 1 wherein the polymer is a poly(styrene-acrylonitrile).
Claim 8
Dependent Claim
14 words
The microcapsule of claim 1 wherein the polymer is selected from polyamides and polyamide-imides.
Claim 9
Dependent Claim
21 words
The microcapsule of claim 1 wherein the active ingredient is selected from pheromones, insecticides, herbicides, fertilizers, pharmaceuticals, deodorants, fragrances, and flavors.
Claim 10
Dependent Claim
12 words
The microcapsule of claim 1 wherein the active ingredient is a pheromone.
Claim 11
Dependent Claim
22 words
The microcapsule of claim 9 wherein the pheromone is selected from disparlure, gossyplure, virelure, muscalure, grandlure, japonilure, trimedlure, codlure and periplanone B.
Claim 12
Dependent Claim
12 words
The microcapsule of claim 1 wherein the active ingredient is an insecticide.
Claim 13
Dependent Claim
24 words
The microcapsule of claim 11 wherein the insecticide is selected from naled, dimpylate, propoxur, chlorpyrifos, malathion, methyl parathion, carbaryl, methomyl, permethrin, fenvalerate and dichlorvos.
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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) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |