US3891570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing microcapsules
Assignee: Toyo Jozo KK
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Filing: 1973-01-26
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Granted: 1975-06-24
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Expires: 1993-01-26
Abstract
Abstract Microcapsules are made by dissolving or dispersing a core substance in a solution of a wall material dissolved in a solvent having a dielectric constant of about 10 or less and poorly miscible with a polyhydric alcohol, then emulsifying in fine droplets this dispersion or solution into the polyhydric alcohol and finally removing the solvent through evaporation.
Inventors
- 👤 Mitsuru Fukushima
- 👤 Yoshihito Inaba
- 👤 Sadami Kobari
- 👤 Masataka Morishita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:57
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5089; A61K9/14; A61K9/16; A61K9/1682; A61K9/1694; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/12; B01J13/125; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2987; Y10T428/2989
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
76 words
A PROCESS FOR PREPARING MICROCAPSULES, WHICH COMPRISES PREPARING A DISPERSION OR A SOLUTON OF A CORE SUBSTANCE IN A SOLUTION OF A WALL MATERIAL DISSOLVED IN A SOLVENT HAVING A DIELECTRIC CONSTANT OF ABOUT 10 OR LESS, EMULSIFYING THE THUS PREPARED DISPERSION OR SOLUTION IN THE FORM OF FINE DROPLETS WITHIN A LIQUID VEHICLE CONSISTING ESSENTIALLY OF A POLYHYDRIC ALCOHOL WHICH IS POORLY MISCIBLE WITH SAID SOLVENT AND EVAPORATING THE SOLVENT FROM SOLUTION THROUGH SAID VEHICLE.
Claim 2
Dependent Claim
76 words
A PROCESS FOR PREPARING MICROCAPSULES, WHICH COMPRISES PREPARING A DISPERSION OR A SOLUTON OF A CORE SUBSTANCE IN A SOLUTION OF A WALL MATERIAL DISSOLVED IN A SOLVENT HAVING A DIELECTRIC CONSTANT OF ABOUT 10 OR LESS, EMULSIFYING THE THUS PREPARED DISPERSION OR SOLUTION IN THE FORM OF FINE DROPLETS WITHIN A LIQUID VEHICLE CONSISTING ESSENTIALLY OF A POLYHYDRIC ALCOHOL WHICH IS POORLY MISCIBLE WITH SAID SOLVENT AND EVAPORATING THE SOLVENT FROM SOLUTION THROUGH SAID VEHICLE.
Claim 3
Dependent Claim
38 words
A process for preparing microcapsules according to claim 1 wherein the polyhydric alcohol is ethylene glycol, propylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, hexylene glycol, pentanediol-2,4, hexanediol-2,5, heptanediol-2,4, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, or glycerine.
Claim 4
Dependent Claim
20 words
A process for preparing microcapsules according to claim 2, wherein the polyhydric alcohol is ethylene glycol, propylene glycol or glycerine.
Claim 5
Dependent Claim
51 words
A process for preparing microcapsules according to claim 1 wherein the solvent is methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, diethyl ether, methyl ethyl ether, hexane, heptane, cyclohexane, petroleum ether, benzene, nitro methane, carbon disulfide, toluene, methyl acetate, ethyl acetate, butyl acetate, amyl acetate, methyl formate, ethyl formate, or butyl formate.
Claim 6
Dependent Claim
54 words
A process for preparing microcapsules according to claim 1 wherein the wall material is ethyl cellulose, cellulose acetate, hydroxypropyl methyl cellulose phthalate, cellulose acetate dibutyl aminohydroxypropyl ether, polyvinyl butyral, polyvinyl formal, polystyrene, polyacrylic acid ester, polymethacrylic acid ester, polyvinyl acetal-diethylamino acetate, 2-methyl-5-vinyl pyridine methacrylate-methacrylic acid copolymer, polycarbonate, polyester, polypropylene, or vinyl chloride-vinyl acetate copolymer.
Claim 7
Dependent Claim
25 words
A process for preparing microcapsules according to claim 1 wherein the sizes of the fine droplets are controlled To from several microns to 1000 microns.
Claim 8
Dependent Claim
32 words
A process for preparing microcapsules according to claim 1 wherein the ratio of the amount of the wall material over the core substance is from 1/5 to 10 based on the weight.
Claim 9
Dependent Claim
23 words
A process for preparing microcapsules according to claim 1 wherein an enzyme or an aqueous enzyme solution is used as a core substance.
Claim 10
Dependent Claim
26 words
A process for preparing microcapsules according to claim 7 wherein the concentration of the wall material in the solvent is from 2.5 to 25 W/V percent.
Claim 11
Dependent Claim
30 words
A process for preparing microcapsules according to claim 9 wherein the amount of the polyhydric alcohol is from 4 to 50 times the amount of the solvent based on volume.
Claim 12
Dependent Claim
24 words
A process for preparing microcapsules according to claim 1, wherein said polyhydric alcohol has a viscosity of from 10 to 500 centipoises at 25*C.
Claim 13
Dependent Claim
24 words
A process for preparing microcapsules according to claim 11, wherein said solvent has a boiling point less than the boiling point of said vehicle.
Claim 14
Dependent Claim
24 words
A process for preparing microcapsules according to claim 1, wherein said polyhydric alcohol has a viscosity of from 15 to 200 centipoises at 25*C.
Claim 15
Dependent Claim
17 words
A process for preparing microcapsules according to claim 1, wherein said vehicle consists of said polyhydric alcohol.
Claim 16
Dependent Claim
30 words
A process for preparing microcapsules according to claim 1, wherein said solvent is entirely immiscible or miscible in amounts not more than about 15 percent by volume with said vehicle.
Claim 17
Dependent Claim
21 words
A process for preparing microcapsules according to claim 1, wherein the wall material comprises a polymeric material soluble in said solvent.
Claim 18
Dependent Claim
18 words
A process for preparing microcapsules according to claim 1, further comprising separating the microcapsules from said liquid vehicle.
References Cited (Backward Citations)
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US3664963A
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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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |