Patent EA-004158-B1 (EA)
Title: Controlled release device for the preservation of wooden structure proximate soil
Inventor: VAN VORIS PETER
IPC: A01M1/20
Filed: 1998-02-20
Abstract: 1. A bound friable mixture, including: (a) at least one bioactive chemical; bound by sorption with (b) a binding carrier. 2. The bound friable mixture as recited in claim 1, wherein the binding carrier is selected from the group consisting of carbon black, activated carbon, alumina, hydroxyapatite, silicoalumina and combinations thereof. 3. The bound friable mixture as recited in claim 1, further including a pre-polymer. 4. The bound friable mixture as recited in claim 3, wherein the pre-polymer is polyethylene. 5. The bound friable mixture as recited in claim 1, wherein the bioactive chemical is in a liquid form during forming said friable mixture. 6. A controlled release device for deterring, repelling or killing pests including the bound friable mixture of claim 1 dispersed within a continuous polymeric matrix. 7. The controlled release device as recited in claim 6, wherein said bioactive chemical comprises a pesticide selected from the group consisting of pyrethroid, isofenphos, fenvalerate, water soluble bioactive chemicals, tefluthrin, permethrin, fenoxycarb, chlorpyrifos, lambdacyhalothrin, resmethrin, deltamethrin, cypermethrin, cyphenothrin, cyfluthrin, and combinations thereof. 8. The controlled release device as recited in claim 6, wherein said bioactive chemical includes at least one fungicide. 9. The controlled release device as recited in claim 8, wherein said fungicide is selected from the group consisting of tri-chloronitromethane, a mixture of methylisothiocyanate and 1,3 dichloropropane, sodium N-methyl dithiocarbomate, 2,3,5,6-tetracholoro-1,9-benzoquinone, calcium cyanamide, biphenyl, copper naphthenate, dichlorphen, fentin hydroxide and combinations thereof. 10. The controlled release device as recited in claim 6, wherein said binding carrier is carbon black. 11. The controlled release device as recited in claim 6, wherein said polymer of said polymeric matrix is hydrophobia. 12. The controlled release device as recited in claim 6, wherein the polymer of said polymeric matrix is selected from the group consisting of low density polyethylene, high density polyethylene, vinyl acetate, urethane, polyester, silicone, neoprene, isoprene and combinations thereof. 13. The controlled release device as recited in claim 12, wherein the particles of said bound friable mixture are enveloped within the polymeric matrix. 14. The controlled release device as recited in claim 11, wherein said polymeric matrix is in the form of a rod, pellet, strip or sheet. 15. The controlled release device as recited in claim 6, wherein the polymeric matrix is in the form of a sheet. 16. The controlled release device as recited in claim 15, wherein said controlled release device further includes a second sheet for retarding or preventing photo-degradation of said bioactive chemical. 17. The controlled release device as recited in claim 16, further including a third sheet containing metallized Mylar, saran, or combinations thereof. 18. The controlled release device as recited in claim 17, wherein said bioactive material comprises at least one pesticide selected from the group consisting of pyrethroid, isofenphos, fenvalerate, water soluble bioactive chemicals, tefluthrin, permethrin, fenoxycarb, chlorphyrifos, lambdacyhalothrin, resmethrin, deltamethrin, cypermethrin, cypermethrin, cyphenothrin, cyfluthrin, and combinations thereof. 19. The controlled release device as recited in claim 17, wherein said bioactive chemical is lambdacyhalothrin. 20. The controlled release device as recited in claim 19, wherein the polymeric matrix includes low density polyethylene. 21. The controlled release device as recited in claim 6, wherein said bioactive chemical includes at least one pesticide having a vapor pressure greater than about 0.1 mm Hg at 25 degree C. 22. The controlled release device as recited in claim 6, wherein said polymer of said polymeric matrix is in an amount from about 50 to about 90 parts by weight of said matrix and said bioactive chemical releases from said matrix at a rate from about 0.4 mkg/cm<2>/ day to about 40 mkg/cm<2>/ day. 23. The controlled release device as recited in claim 14, wherein the polymer is in an amount from about 50 to about 90 parts by weight of the matrix, the pesticide is in an amount from about 5 to about 30 parts by weight of the matrix and the carrier is in an amount from about 10 to about 20 parts by weight of the matrix. 24. A method of making a controlled release device useful for deterring, repelling, or killing pests, said method having the following steps: (a) forming a friable mixture including a binding carrier and at least one bioactive chemical so as to bind said bioactive chemical to said carrier; and (b) incorporating said bound particles of said carrier and said bioactive chemical into a polymer to form a polymeric matrix containing said bound particles. 25. The method of claim 24, wherein the step of incorporating includes forming a melt of the polymer and the bound particles of said friable mixture. 26. The method of claim 25, wherein the friable mixture includes the carrier, the bioactive chemical and a prepolymer. 27. The method as recited in claim 24, wherein the bioactive chemical is in a liquid form. 28. The method as recited in claim 27, wherein the bioactive chemical is a pesticide selected from the group consisting of pyrethroid, isofenphos, fenvalerate, water-soluble bioactive chemicals, tefluthrin, permethrin, fenoxycarb, chlorpyrifos, lambdacyhalothrin, resmethrin, deltamethrin, cypermethrin, cyphenothrin, cyfluthrin, and combinations thereof. 29. The method as recited in claim 24, wherein the bioactive chemical includes lambdacyhalothrin. 30. The method as recited in claim 25, wherein the bioactive chemical is a fungicide selected from the group consisting of tri-chloronitromethane, a mixture of methylisothiocyanate and 1,3 dichloropropane, sodium N-methyl dithiocarbomate, 2,3,5,6-tetracholoro-1,9-benzoquinone, calcium cyanamide, biphenyl, copper naphthenate, dichlorphen, fentin hydroxide, and combinations thereof. 31. The method as recited in claim 25, wherein the bioactive chemical includes a fungicide selected from the group consisting of tri-chloronitromethane, a mixture of methylisothiocyanate and 1, 3 dichloropropane, sodium N-methyl dithiocarbomate, 2,3,5,6-tetracholoro-1,9-benzoquinone, calcium cyanamide, biphenyl, copper naphthenate, dichlorphen, fentin hydroxide, and combinations thereof and further includes an insecticide selected from the group consisting of pyrethroid, isofenphos, fenvalerate, water soluble bioactive chemicals, and combinations thereof. 32. The method as recited in claim 28, wherein the pesticide is in an amount from about 5 to about 30 parts by weight of the polymeric matrix, the polymer is in an amount from about 50 to about 90 parts by weight of the polymeric matrix and the binding carrier is in an amount from about 10 to about 20 parts by weight of the polymeric matrix. 33. The method as recited in claim 27, wherein said polymer is a hydrophobia polymer. 34. The method as recited in claim 27, wherein said polymer is selected from the group consisting of low density polyethylene, high density polyethylene, vinyl acetate, urethane, polyester, silicone, neoprene, isoprene and combinations thereof. 35. The method as recited in claim 27, further including the step of forming said matrix into a rod, pellet, strip or sheet. 36. The method as recited in claim 27, wherein said bioactive chemical is a low vapor pressure pesticide, wherein said low vapor pressure pesticide is combined with a high density pre-polymer. 37. The method as recited in claim 27, wherein said pre-polymer is selected from the group consisting of high density polyethylene. 38. The method as recited in claim 27, wherein said bioactive chemical is a water-soluble fungicide. 39. The method as recited in claim 26, wherein said pre-polymer is selected from the group consisting of urethane, polyester, low density polyethylene, and combinations thereof. 40. The method as recited in claim 26, wherein said pre-polymer is a low-density polyethylene. 41. The method as recited in claim 27, further including the step of drying said binding carrier prior to mixing with said bioactive chemical. 42. A method of preventing or retarding decay and deterioration of a wooden object from wood attacking pests, including the steps of: (a) making the controlled release device as recited in claim 24 with a release rate of at least about 0.4 mkg/cm<2>/day; (b) creating a cavity in the wooden object; (c) inserting the controlled release device into the cavity and closing the cavity: and (d) permitting at least one bioactive chemical to vaporize from a surface of said controlled release device and to diffuse into the molecular wood structure of the wooden object thereby creating an exclusion zone within the wooden object having a concentration of the bioactive chemical above a minimum effective concentration preventing pest invasion into said exclusion zone. 43. A method of preventing the decay and deterioration of wooden objects in contact with soil caused by the invasion of pests including the steps of: (a) making a controlled release device as recited in claim 24; (b) placing the controlled release device proximate the wooden object, the concentration of the bioactive chemical being sufficient to provide a predetermined release rate through said polymer and sufficient to provide a minimal effective level to prevent pest intrusion for a predetermined period of time. 44. The method as recited in claim 43, wherein the controlled release device releases bioactive chemical at an initially high rate and a lower, steady state rate thereafter. 45. The method as recited in claim 43, wherein the minimal effective level is maintained throughout the whole wooden structure. 46. The method as recited in claim 43, wherein the minimal effective level is maintained in a zone of the wooden structure. 47.