US4557755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microencapsulated agricultural chemical and process of preparation thereof
Assignee: Kureha Corp
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Filing: 1982-07-23
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Granted: 1985-12-10
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Expires: 2002-07-23
Abstract
Abstract A microencapsulated agricultural chemical comprises an agricultural chemical as an active ingredient having a solubility of not more than 1 g in 100 ml of water at 20° C. and vapor pressure of not more than 760 mmHg at 60° C. and a microcapsule wall enclosing the agricultural chemical therein and the microcapsule wall comprises a water-soluble cationic urea resin and at least one of prepolymer composed of formaldehyde and at least one compound selected from the group consisting of urea, melamine and thiourea. The microcapsule is prepared by dispersing the agricultural chemical in an aqueous medium containing the water-soluble cationic urea resin, an anionic surfactant and at least one of the prepolymer and maintaining pH of the obtained dispersion within an acidic range to polycondense the water-soluble cationic urea resin and at least one of the prepolymers.
Inventors
- 👤 Masaaki Takahashi
- 👤 Yuji Hattori
- 👤 Yuriko Igarashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:38
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/18; A; A01; A01N; A01N25/00; A01N25/26; A01N25/28; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2989
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
A process for preparing a microencapsulated agricultural chemical, comprising dispersing an agricultural chemical having a solubility of not more than 1 g in 100 ml of water at 20° C. and a vapor pressure of not more than 760 mmHg at 60° C. in an aqueous medium consisting essentially of a water-soluble cationic urea resin, an anionic surfactant selected from the group consisting of salts of aliphatic acids, sulfate esters of higher alcohols, and salts of alkylaryl sulfonic acids and at least one prepolymer formed from formaldehyde and at least one compound selected from the group consisting of urea, melamine, and thiourea, and maintaining the pH of the obtained dispersion within an acidic range to polycondense the water-soluble cationic urea resin and said prepolymer by adding an acid catalyst.
Claim 2
Dependent Claim
129 words
A process for preparing a microencapsulated agricultural chemical, comprising dispersing an agricultural chemical having a solubility of not more than 1 g in 100 ml of water at 20° C. and a vapor pressure of not more than 760 mmHg at 60° C. in an aqueous medium consisting essentially of a water-soluble cationic urea resin, an anionic surfactant selected from the group consisting of salts of aliphatic acids, sulfate esters of higher alcohols, and salts of alkylaryl sulfonic acids and at least one prepolymer formed from formaldehyde and at least one compound selected from the group consisting of urea, melamine, and thiourea, and maintaining the pH of the obtained dispersion within an acidic range to polycondense the water-soluble cationic urea resin and said prepolymer by adding an acid catalyst.
Claim 3
Dependent Claim
12 words
The process of claim 1, wherein the prepolymer is a urea-formaldehyde prepolymer.
Claim 4
Dependent Claim
12 words
The process of claim 1, wherein the prepolymer is a melamine-formaldehyde prepolymer.
Claim 5
Dependent Claim
12 words
The process of claim 1, wherein the prepolymer is a urea-melamine-formaldehyde prepolymer.
Claim 6
Dependent Claim
12 words
The process of claim 1, wherein the prepolymer is a thio-urea-melamine-formaldehyde prepolymer.
Claim 7
Dependent Claim
17 words
The process of any one of claims 2 and 1, wherein the agricultural chemical is a pesticide.
Claim 8
Dependent Claim
17 words
The process of any one of claims 2 and 1, wherein the agricultural chemical is a fungicide.
Claim 9
Dependent Claim
16 words
The process of any one of claims 2 and 1, wherein the agricultural chemical is pheromone.
Claim 10
Dependent Claim
29 words
The process of claim 1, wherein the dispersion is maintained at pH of 2.5 to 6.0 and the temperature of 15° to 60° C. for 2 to 50 hours.
Claim 11
Dependent Claim
11 words
A microencapsulated agricultural chemical produced by the process of claim 1.
References Cited (Backward Citations)
US3074845A
Cited
DE1444414A1
Cited
US3516941A
Cited
US3607775A
Cited
DE2147237A1
Cited
US3778383A
Cited
GB1507739A
Cited
US4105823A
Cited
US4223060A
Cited
EP0046415A1
Cited
GB2094257A
Cited
US4460722A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-09 | 1989-06-10 | 1989-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-09 | 1993-06-10 | 1993-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-09 | 1997-06-10 | 1997-12-10 | $7700.00 | Window Closed / Lapsed |