Patent US4497793A successfully refreshed from Google Patents.
US4497793A
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US
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Microencapsulated naturally occuring pyrethrins
Assignee: Arkema Inc
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Filing: 1983-02-25
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Granted: 1985-02-05
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Expires: 2003-02-25
Abstract
Abstract A process for microencapsulating naturally-occurring pyrethrins with a polyamide-polyurea shell by interfacial condensation which includes slowly adding an amine reactant to an aqueous emulsion containing the pyrethrin, an isocyanate, and an acyl halide with the requirement that at least one of said isocyanate or said acyl halide is polyfunctional, to provide free flowing capsules having a polyamide-polyurea wall encapsulating the natural pyrethrin.
Inventors
- 👤 Joseph Simkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:17
CPC Classifications
A; A01; A01N; A01N25/00; A01N25/26; A01N25/28; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/16; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
126 words
A process for microencapsulating naturally-occurring pyrethrins with a polyamide-polyurea shell by interfacial condensation of complementary, organic, di- or polyfunctional polycondensate-forming intermediates reacting to form a polyamide-polyurea condensate, comprising (a) forming a suspension in an aqueous emulsion of (i) the naturally-occurring pyrethrin to be microencapsulated; (ii) at least one isocyanate; and (iii) at least one acyl halide; with at least one of said isocyanate or said acyl halide being polyfunctional; and then (b) adding to the aqueous emulsion of (a), with agitation under reaction conditions, at least one amine at such a rate as to maintain the concentration of unreacted amine below 1000 parts per million of total weight of (a) and (b), to provide substantially non-agglomerated, free-flowing microcapsules of said pyrethrin having a shell of polyamide-polyurea.
Claim 2
Dependent Claim
126 words
A process for microencapsulating naturally-occurring pyrethrins with a polyamide-polyurea shell by interfacial condensation of complementary, organic, di- or polyfunctional polycondensate-forming intermediates reacting to form a polyamide-polyurea condensate, comprising (a) forming a suspension in an aqueous emulsion of (i) the naturally-occurring pyrethrin to be microencapsulated; (ii) at least one isocyanate; and (iii) at least one acyl halide; with at least one of said isocyanate or said acyl halide being polyfunctional; and then (b) adding to the aqueous emulsion of (a), with agitation under reaction conditions, at least one amine at such a rate as to maintain the concentration of unreacted amine below 1000 parts per million of total weight of (a) and (b), to provide substantially non-agglomerated, free-flowing microcapsules of said pyrethrin having a shell of polyamide-polyurea.
Claim 3
Dependent Claim
22 words
The process as defined in claim 1 wherein in (a) (i) said pyrethrin has been admixed with at least one synthetic pyrethrin.
Claim 4
Dependent Claim
61 words
The process as defined in claim 2 wherein in (a) (iii) said acyl halide is selected from the group of acyl halides consisting essentially of sebacoyl chloride; ethylene-bis-chloroformate; phosgen; azelaoyl chloride; adipoyl chloride; terephthaloyl chloride; dodecanedioic acid chloride; dimer acid chloride; 1,3-benzene disulfonyl chloride; trimesoyl chloride; 1,2,4,5-benzene tetra-acid chloride; 1,3,5-benzene trisulfonyl chloride; trimer acid chloride; citric acid chloride; and 1,3,5-benzene tris-chloroformate.
Claim 5
Dependent Claim
50 words
The process as defined in claim 3 wherein in (b) said amine is selected from the group of amines consisting essentially of ethylene diamine; phenylene diamine; toluene diamine; hexamethylene diamine; diethylene triamine; triethylene tetramine; piperidine; 1,3,5-benzenetriamine trihydrochloride; 2,4,6-triaminotoluene trihydrochloride; tetraethylene pentamine; pentaethylene hexamine; polyethylene amine; 1,3,6-triamino-naphthalene; 3,4,5-triamino-1,2,4-triazole; melamine; and 1,4,5,8-tetraaminoanthraquinone.
Claim 6
Dependent Claim
55 words
The process as defined in claim 1 wherein in (a) (ii) said isocyanate is selected from the group of isocyanates consisting essentially of para-phenylene diisocyanate; meta-phenylene diisocyanate; naphthalene-1,5-diisocyanate; tetrachloro-m-phenylene diisocyanate; 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 4,4-diphenyl-diisocyanate; dichloro diphenyl methane diisocyanate; bibenzyl diisocyanate; bitolylene diisocyanate; diphenyl ester diisocyanate; dimethyldiphenyl diisocyanate; polymethylene polyphenyl isocyanate; triphenylmethane-4,4,4'-triisocyanate; and isopropylbenzene alpha-diisocyanate.
Claim 7
Dependent Claim
16 words
The process of claim 1 wherein said amine is maintained below a concentration of 400 ppm.
Claim 8
Dependent Claim
16 words
A persistent, naturally-occurring pyrethrin insecticide which has been microencapsulated according to the process of claim 1.
Claim 9
Dependent Claim
11 words
The insecticide of claim 7 wherein said pyrethrin has been synergized.
Claim 10
Dependent Claim
17 words
The insecticide of claim 7 wherein said pyrethrin has been admixed with at least one synthetic pyrethrin.
Claim 11
Dependent Claim
11 words
The insecticide of claim 9 wherein said pyrethrin has been synergized.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |