Patent US3873346A successfully refreshed from Google Patents.
US3873346A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of forming self-destructing pesticidal formulations
Assignee: United States Department of the Interior
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Filing: 1973-10-11
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Granted: 1975-03-25
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Expires: 1993-10-11
Abstract
Abstract Pesticidal compositions are formulated by depositing a layer of elemental sulfur on a particulate metal core and then adhesively depositing a normally persistant pesticide such as DDT on the exterior surface of the sulfur layer. The core metal is selected from those metals and metallic couples, such as zinc or zinccopper, which degrade the pesticide under acidic conditions to form products having greatly reduced physiological activity. The sulfur layer acts to temporarily isolate the pesticide from the metallic core and to later react with air and moisture under field conditions to produce a locally acidic environment for reaction of the pesticide with the metallic core.
Inventors
- 👤 Keith H Sweeny
- 👤 James R Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:11
CPC Classifications
A; A01; A01N; A01N25/00; A01N25/32
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
86 words
A PROCESS FOR MAKING A COMPOSITE PESTICIDAL COMPOSITION HAVING SELF-DESTRUCTING PROPERTIES WHICH COMPRISES: DEPOSITING A LAYER OF AN AXID-PRODUCING MATERIAL COMPRISING ELEMENTAL SULFUR UPON A CENTRAL PARTICULATE CORE, SAID CORE COMPRISING A METALLIC REDUCTANT, SAID METALLIC REDUCTANT BEING CAPABLE OF REACTING WITH CHLORINATED ORGANIC PESTICIDES IN AN ACIDIC ENVIRONMENT TO PRODUCE RELATIVELY INNOCUOUS DEGRADATION PRODUCTS, AND ADHESIVELY DEPOSITING A PESTICIDE CHOSEN FROM THE GROUP CONSISTING OF DDT, TOXAPHENE, LINDANE, METHOXYCHLOR, DIELDRIN, KELTHANE, CHLORDANE, PERTHANE, ENDRIN, ALDRIN AND HEPTACHLOR UPON THE EXTERIOR SURFACE OF SAID SULFUR LAYER.
Claim 2
Dependent Claim
86 words
A PROCESS FOR MAKING A COMPOSITE PESTICIDAL COMPOSITION HAVING SELF-DESTRUCTING PROPERTIES WHICH COMPRISES: DEPOSITING A LAYER OF AN AXID-PRODUCING MATERIAL COMPRISING ELEMENTAL SULFUR UPON A CENTRAL PARTICULATE CORE, SAID CORE COMPRISING A METALLIC REDUCTANT, SAID METALLIC REDUCTANT BEING CAPABLE OF REACTING WITH CHLORINATED ORGANIC PESTICIDES IN AN ACIDIC ENVIRONMENT TO PRODUCE RELATIVELY INNOCUOUS DEGRADATION PRODUCTS, AND ADHESIVELY DEPOSITING A PESTICIDE CHOSEN FROM THE GROUP CONSISTING OF DDT, TOXAPHENE, LINDANE, METHOXYCHLOR, DIELDRIN, KELTHANE, CHLORDANE, PERTHANE, ENDRIN, ALDRIN AND HEPTACHLOR UPON THE EXTERIOR SURFACE OF SAID SULFUR LAYER.
Claim 3
Dependent Claim
35 words
The process of claim 1 wherein the metallic reductant making up the central core is chosen from the group consisting of metallic zinc and the metallic couples of zinc-copper, zinc-silver, aluminum-copper, iron-copper, magnesium-copper and cadmium-copper.
Claim 4
Dependent Claim
30 words
The process of claim 2 wherein the pesticide is DDT and wherein the metallic particle is chosen from the group consisting of the metallic couples of zinc-copper, aluminum-copper and iron-copper.
Claim 5
Dependent Claim
28 words
The process of claim 3 wherein the metallic couple is present in 2 to 10 fold excess over that amount stoichiometrically required to completely react with the DDT.
Claim 6
Dependent Claim
30 words
The process of claim 4 wherein the metallic central core has a diameter greater than about 5 microns and the composite particle has a diameter less than about 20 microns.
References Cited (Backward Citations)
US1911868A
Cited
US2069710A
Cited
US2165206A
Cited
US2414193A
Cited
US3295950A
Cited
US3672945A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |