CA2147078A1 - Composite polymer devices for controlled release of semiochemicals - Google Patents
Composite polymer devices for controlled release of semiochemicalsInfo
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- CA2147078A1 CA2147078A1 CA 2147078 CA2147078A CA2147078A1 CA 2147078 A1 CA2147078 A1 CA 2147078A1 CA 2147078 CA2147078 CA 2147078 CA 2147078 A CA2147078 A CA 2147078A CA 2147078 A1 CA2147078 A1 CA 2147078A1
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- acetate
- semiochemical
- controlled release
- methyl
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Abstract
COMPOSITE POLYMER DEVICES FOR CONTROLLED
RELEASE OF SEMIOCHEMICALS
ABSTRACT OF THE DISCLOSURE
Composite polymer dispensers capable of controlled release of semiochemicals have been developed.
The dispensers make use of a solid elasomer matrix reservoir which is at least partially surrounded by release rate controlling polymer membrane. The matrix materials are polyurethanes compatible with many types of semiochemicals and additives. The release rates of semiochemicals from the dispensers can be varied over a wide range by manipulation of the reservoir conditions and by selection of the type of polymer membrane surrounding the device. The dispensers can have a variety of forms and can be produced by a simple process. The semiochemical devices produced by this method are useful for managing insect and other pests through attraction to traps, for population monitoring or for mass trapping. The devices may also be used to dispense anti-aggregation pheromones or repellents in addition to use for mating confusion or disruption.
RELEASE OF SEMIOCHEMICALS
ABSTRACT OF THE DISCLOSURE
Composite polymer dispensers capable of controlled release of semiochemicals have been developed.
The dispensers make use of a solid elasomer matrix reservoir which is at least partially surrounded by release rate controlling polymer membrane. The matrix materials are polyurethanes compatible with many types of semiochemicals and additives. The release rates of semiochemicals from the dispensers can be varied over a wide range by manipulation of the reservoir conditions and by selection of the type of polymer membrane surrounding the device. The dispensers can have a variety of forms and can be produced by a simple process. The semiochemical devices produced by this method are useful for managing insect and other pests through attraction to traps, for population monitoring or for mass trapping. The devices may also be used to dispense anti-aggregation pheromones or repellents in addition to use for mating confusion or disruption.
Description
21'17078 COMPOSITE POLYMER DEVICES FOR CONTROLLED
REL~ASE OF SEMIOCEeMICALS
FIELD OF THE INVENTION
This invention pertains to novel and versatile devices for use as semiochemical controlled release dispensers. More particularly, hydroxy-terminated polybutadiene resins, or other polyols, can be combined with semiochemicals, additives, and an isocyanate component to produce a solid phase reservoir surrounded at least partially by a release rate controlling polymer membrane.
BACKGROUND OF THE INVENTION
Semiochemicals are an extremely diverse group of chemicals that mediate interaction between organisms (Nordlund et al. 1981). Semiochemicals transmit signals to members of the same species as well as different species.
These chemicals (semiochemicals) have been identified in many organisms including bacteria, yeast, plants, insects and animals. Often semiochemicals are not emitted as a pure chemical, but rather as a blend of several compounds.
The most studied group of semiochemicals are the pheromones, which transmit chemical signals within the same species (The Merck Index, 11th ed.) and have been identified in at least 1,600 species (Mayer and McLaughlin 1990, Arn et al. 1992). Kairomones, allomones and synomones are other types of semiochemicals that are intra species signals (Nordlund et al. 1981). Allomones are compounds that serve to benefit the emitting species, while kairomones benefit the perceiving species. Synomones are chemical signals which serve to benefit both the emitting and perceiving species. It is also worth noting that the terms pheromone, allomone and kairomone are not mutually exclusive. For example, a semiochemical may be a pheromone in one species while the same chemical acts as a kairomone for predators of that species.
21~7078 Semiochemicals have the potential to modify behaviour and they have shown utility in integrated pest management in forestry, agriculture and urban industrial locations (Mitchell 1981, Ridgway et al. 1990~. Other compounds of use in integrated pest management also include synthetic chemicals that mimic the biological actions of semiochemicals, for example the ~male lures~ of terphritid fruit flies (Cunningham et al. 1990). These synthetic chemicals that mimic the actions of semiochemicals are herein considered to be included in the group known as semiochemicals.
In contrast to pesticides, semiochemicals do not work through toxic action and in general are of low toxicity to non-target species (Ridgway et al. 1992).
Pesticides tend to be broad spectrum in the organisms affected while semiochemicals are much more specific, affecting at most a few species. Semiochemicals can often replace or substantially reduce the amount of pesticide needed for pest control applications. Semiochemical use in pest management may include strategies such as population monitoring, mass trapping, barrier trapping, and mating disruption. The use of anti-aggregation pheromones, alarm pheromones, anti-feedants, oviposition deterrents, and other types of behaviour modifying chemicals are known.
Synthetic chemical methods have permitted access to many semiochemicals that occur in nature. However, widespread use of these chemicals in pest control applica~ions has been limited partly by difficulties encountered in controlled delivery of the chemicals to the environment. Semiochemical-based pest management relies to a large extent on slow release device technology for its successful implementation. For example, the use of insect pheromones to lure pests to traps used for population monitoring requires a very specific delivery rate. Too low a delivery rate may be below the threshold of perception, . ~ .
,.
,.
`_. 2:1~7078 while too high a delivery rate may confuse or repel the insect and prevent the insect from entering the trap.
Zeoli et al. (1982) have summarized controlled release technologies and have categorized the dispensers types into four groups.
1. Monolithic systems These consist of inert polymeric matrices impregnated with the semiochemical as the active ingredient (AI). Such devices are simple and they lend themselves to a number of applications. However, the release characteristics depend largely on the shape of the device, and the capacity of the polymer to hold the semiochemical, both of which may limit the longevity of the device.
Release of AI from monolithic devices tends to be logar.thmic over time. Examples of this technology are polyvinylchloride (PVC) impregnated with semiochemical (Fitzgerald et al. 1973) or silicone rubber impregnated with fragrances as in US patent 4725575 (Union Camp Co.), or silicone-urethane copolymers used as matrices for dispensing fragrances or pheromones as in US patents 4908208 and 5008115 (Dow Corning Co.), urethane matrices for dispensing pesticides as in US patent 4594380 (AT&T
Bell Laboratories) or acrylate polymers impregnated with pheromones (Smith et al. 1991 and Kim et al. 1988).
REL~ASE OF SEMIOCEeMICALS
FIELD OF THE INVENTION
This invention pertains to novel and versatile devices for use as semiochemical controlled release dispensers. More particularly, hydroxy-terminated polybutadiene resins, or other polyols, can be combined with semiochemicals, additives, and an isocyanate component to produce a solid phase reservoir surrounded at least partially by a release rate controlling polymer membrane.
BACKGROUND OF THE INVENTION
Semiochemicals are an extremely diverse group of chemicals that mediate interaction between organisms (Nordlund et al. 1981). Semiochemicals transmit signals to members of the same species as well as different species.
These chemicals (semiochemicals) have been identified in many organisms including bacteria, yeast, plants, insects and animals. Often semiochemicals are not emitted as a pure chemical, but rather as a blend of several compounds.
The most studied group of semiochemicals are the pheromones, which transmit chemical signals within the same species (The Merck Index, 11th ed.) and have been identified in at least 1,600 species (Mayer and McLaughlin 1990, Arn et al. 1992). Kairomones, allomones and synomones are other types of semiochemicals that are intra species signals (Nordlund et al. 1981). Allomones are compounds that serve to benefit the emitting species, while kairomones benefit the perceiving species. Synomones are chemical signals which serve to benefit both the emitting and perceiving species. It is also worth noting that the terms pheromone, allomone and kairomone are not mutually exclusive. For example, a semiochemical may be a pheromone in one species while the same chemical acts as a kairomone for predators of that species.
21~7078 Semiochemicals have the potential to modify behaviour and they have shown utility in integrated pest management in forestry, agriculture and urban industrial locations (Mitchell 1981, Ridgway et al. 1990~. Other compounds of use in integrated pest management also include synthetic chemicals that mimic the biological actions of semiochemicals, for example the ~male lures~ of terphritid fruit flies (Cunningham et al. 1990). These synthetic chemicals that mimic the actions of semiochemicals are herein considered to be included in the group known as semiochemicals.
In contrast to pesticides, semiochemicals do not work through toxic action and in general are of low toxicity to non-target species (Ridgway et al. 1992).
Pesticides tend to be broad spectrum in the organisms affected while semiochemicals are much more specific, affecting at most a few species. Semiochemicals can often replace or substantially reduce the amount of pesticide needed for pest control applications. Semiochemical use in pest management may include strategies such as population monitoring, mass trapping, barrier trapping, and mating disruption. The use of anti-aggregation pheromones, alarm pheromones, anti-feedants, oviposition deterrents, and other types of behaviour modifying chemicals are known.
Synthetic chemical methods have permitted access to many semiochemicals that occur in nature. However, widespread use of these chemicals in pest control applica~ions has been limited partly by difficulties encountered in controlled delivery of the chemicals to the environment. Semiochemical-based pest management relies to a large extent on slow release device technology for its successful implementation. For example, the use of insect pheromones to lure pests to traps used for population monitoring requires a very specific delivery rate. Too low a delivery rate may be below the threshold of perception, . ~ .
,.
,.
`_. 2:1~7078 while too high a delivery rate may confuse or repel the insect and prevent the insect from entering the trap.
Zeoli et al. (1982) have summarized controlled release technologies and have categorized the dispensers types into four groups.
1. Monolithic systems These consist of inert polymeric matrices impregnated with the semiochemical as the active ingredient (AI). Such devices are simple and they lend themselves to a number of applications. However, the release characteristics depend largely on the shape of the device, and the capacity of the polymer to hold the semiochemical, both of which may limit the longevity of the device.
Release of AI from monolithic devices tends to be logar.thmic over time. Examples of this technology are polyvinylchloride (PVC) impregnated with semiochemical (Fitzgerald et al. 1973) or silicone rubber impregnated with fragrances as in US patent 4725575 (Union Camp Co.), or silicone-urethane copolymers used as matrices for dispensing fragrances or pheromones as in US patents 4908208 and 5008115 (Dow Corning Co.), urethane matrices for dispensing pesticides as in US patent 4594380 (AT&T
Bell Laboratories) or acrylate polymers impregnated with pheromones (Smith et al. 1991 and Kim et al. 1988).
2. Laminated structures These devices have relatively good release characteristics, approaching zero order (constant) release.
However, the manufacture of these devices requires multiple processing to produce the laminate. Examples of this technology are laminated dispensers described in US patent 4639393 (Herculite Protective Fabrics), and German patent 3524180 (Montedison S.p.A.).
. . ~, . .
However, the manufacture of these devices requires multiple processing to produce the laminate. Examples of this technology are laminated dispensers described in US patent 4639393 (Herculite Protective Fabrics), and German patent 3524180 (Montedison S.p.A.).
. . ~, . .
3. Reservoir svstems without rate-controllinq membranes These can be exemplified by capillary release devices as described in US patent 4017030 (Albany International Co.). These devices have been used despite undesirable high initial losses of semiochemical (Weatherston et al. 1985) and difficulty in handling.
4. Reservoir svstems with a rate-controllinq membrane Dispensers of this type generally provide near constant release characteristics which are governed by a membrane. The membrane composition and surface area can be varied to effect changes in the release rates. Examples are described in US patents 4323556 (Montedison S.p.A.), 4445641 (Bend Research Inc.), 4979673 (I.J. Wilk), 4923119 (Shin-Etsu Chemical Co.), 4793555 (Dow Corning Corp.) and German patent 2945655 (Celamerck G.m.b.H.).
Polyurethane chemistry and polymers are well known and widely distributed in the plastics industry, - however the use of these polymers in semiochemical slow release devices has been limited to silicone-urethane copolymers. The terminology used herein to describe the reactants and the reactive process to produce a polyurethane semiochemical reservoir conforms to the customary meanings as given in "Polyurethane Handbook" ed.
G. Oertel, Hanser Publishers or "The ICI Polyurethanes Book", 2nd Edition, ed. G. Woods, ICI Polyurethanes and John Wiley & Sons. The term "polyol" refers to a molecule with at least two hydroxyl groups. Polymeric polyols usually contain other chemical functionalities and the most common types of polyols used in polyurethane manufacture are polyether polyols (hydroxy-terminated polyethers) and polyester polyols (hydroxy-terminated polyesters).
Generally, polymeric polyols are not pure compounds, but rather mixtures which are usually characterized by the l214707~
average properties of the mixture. The isocyanates described herein are molecules wnich contain at least two isocyanate groups. The term MDI refers to diphenylmethane diisocyanate (predominately 4,4l isomer) which is commonly used in industry as mixtures of pure MDI and polymeric MDI.
SUI~RY OF THE INVENTION
The invention is directed to semiochemical release devices composed of a polyurethane matrix containing an active agent and which is at least partially surrounded by a polymer membrane. The polyurethane matrix is prepared from a reactive mixture comprising a polyol and an isocyanate cross linking agent in the presence of unreactive semiochemicals and additives.
AS defined herein, the expression "semiochemical"
means and includes substances which transmit signals to members of the same species as well as different species.
These semiochemical substances include, inter alia, pure chemicals, blends of chemicals, and chemicals which mimic the biological actions of semiochemicals.
-: -The polyol may be selected from the group consisting of hydroxy-terminated polybutadiene resins, polyether polyols, polyester polyols and mixtures thereof.
The isocyanate component may be selected from the group consisting of monomeric or polymeric diphenylmethane diisocyanates, toluene diisocyanates, isophorone diisocyanate and monomeric or polymeric hexamethylene diisocyanate or mixtures thereof. Semiochemicals compatible with the reactive process may be selected from the functional groups including: alkanes, alkenes, aromatic hydrocarbons, ethers, esters, epoxides, aldehydes, ketones, lactones, nitriles, imines, tertiary amines, thioethers, sulfoxides, sulfones, disulfide compounds, thioesters, orgar.ohalides, and mixtures thereof. Semiochemicals not ~.,' . .-'. .',~; . ~, ' .` . . :
~,. . ; . . ., : ' :
ccmpatible or reactive with the matrix include the functional groups: alcohols, phenols, carboxylic acids, thiols, primary and secondary amines, and amides.
The polyurethane matrix reaction mixture may include anti-oxidants, ultraviolet light absorbers, pigments, dyes, fillers, blowing agents, plasticizers, other resin modifying agents and mixtures thereof, which protect the matrix from aging and weathering and add other desirable characteristics to the matrix.
The reaction mixture is polymerized in a device at least partially surrounded by a polymer layer selected from the group consisting of: polyvinyl chloride (PVC), PVC/vinyl copolymers, low and high density polyethylene, polyethylene/vinyl copolymers, polyvinyl acetate and copolymers, polyethylene terpthalate and copolymers, polypropylene, polyamide, polyimide, polyurethane, polyvinylidene fluoride, fluorinated ethylene proplyene polymers, polytetrafluoroethylene, silicone rubber, butyl rubber, neoprene rubber, isoprene rubber, cellulose acetate and laminated (co-extruded) membrane types (eg.
PVC/fluorinated ethylene propylene polymers, polyethylene/
vinyl acetate, polyethylene/polyethylene terpthalate and the like).
A preferred embodiment of the invention comprises casting the reactive urethane mixture in polymeric tubing and using the tubing as long cylinders, or cut into short cylinders, which serve as semiochemical dispensers.
A semiochemical controlled release dispenser comprising: (a) a polyurethane core formed from a polyol, a polymeric isocyanate and a semiochemical; and (b) a polymeric tubing surrounding a portion of the core.
The semiochemical concentration in the said ~;~
~` .
reservoir can be between about 0.001~ and 80~ by weight of the reservoir. The active ingxedient can be a synthetic behaviour-modifing semiochemical mimic chemical, or a natural or synthetically prepared semiochemical.
DRAWINGS
In the drawings, which represent specific embodiments of the invention, but which should not be regarded as restricting the spirit or scope of the invention in any way:
Figure 1 illustrates a graph which demonstrates cumulative verbenone release at 30 C from urethane lS monolithic devices compared with identical urethane cores partially surrounded by a PVC membrane.
Figure 2 illustrates a graph of average retained Z-11-hexadecenal residue per device aged in a Florida cotton field as a function over time. Figure 2 includes similarly shaped PVC monolithic devices for comparison.
Figure 3 illustrates a plot of mean release rate (mg/day/device) of verbenone from composite polymer release devices according to the invention, as a function of time.
DETAILED DESCRIPTION OF SPECIFIC
EMBODIMENTS OF THE INVENTION
The invention consists of versatile composite polymer devices used for dispensing semiochemicals.
Hydroxy-terminated polybutadiene resins and/or other polyols an be combined with additives, semiochemical(s), and an isocyanate component to produce controlled-release reservoirs. By varying the semiochemical load, the cross-linking density of the polymer matrix, the presence of various resin additives, as well as the type of membrane, ~,~ ;. ., . . . ~ ' 21470~8 a wide variety of required release characteristics can be obtained. Semiochemical dispensers, according to the invention, can be produced under very mild conditions using a simple process that is readily adapted to automated production of a variety of device forms. A qualifying limitation of the invention is that the reaction chemistry which forms the device matrix is not compatible with semiochemicals that have active hydrogen donating groups.
This invention represents a significant improvement in several aspects over semiochemical dispensers described in prior art. The process used to produce devices may be conducted at room temperature and this represents an energy saving over processes using thermal curing (Fitzgerald et al. 1973 and Czechoslovakian patent 8490), melting polymers during semiochemical loading (US patents 4908208 and 5008115) or radiation curing methods (Kim et al. 1988 and Smith et al. 1991). Moreover, sin^e expensive volatile semiochemicals may be lost during thermal processing, the current technology offers further advantages over this type of prior art.
The invention allows the formation of a semiochemical reservoir in a single step whereas many systems prepared using prior art techniques, involve formation of the reservoir or matrix first and then loading a semiochemical. The technology of the invention differs from these devîces in that the semiochemical is incorporated during the polymerization of the matrix.
The subject invention is ~n improvement over prior art monolithic polyurethane or silicone polyurethane copolymer matrices (US patents 4594380, 4908208, and 5008115 ), since the new devices of the invention comprise reservoir systems bounded, at least in part, by a rate-controlling membrane. A wide selection of rate-controlling membrane types is complemented by the ability ~,.
~`:
.
,`!~ ~ .
~' .
2:147078 to vary the semiochemical permeability characteristics of the reservoir. This combination allows the composite polymer devices better controlled release of semiochemicals than can usually be attained using monolithic devices.
Comparisons of the new devices and prior art monolithic dispensers are shown in Examples 1, 3 and 4. The membrane of the composite devices has further advantages over monolithic devices since it also serves to screen out ultraviolet light and limit exposure to oxygen, both of which may contribute to semiochemical degradation in the matrix.
Although the invention as described is not suited to the release of semiochemicals with active hydrogen donating groups, this reactivity can be used to purify relatively crude semiochemicals in situ. Impurities of this nature can be trapped by chemical reaction with the isocyanate component during curing of the matrix. This method avoids the need for additional purification of semiochemicals containing low concentrations of impurities with hydroxyl, carboxyl, sulfhydryl and amino functional groups. Example 2 demonstrates this principle.
The physical form of the subject invention can be highly variable. For example, fillers or blowing agents may be included in the matrix formulation to produce a reservoir where a high surface area is desired. Additives may be used to absorb or reflect radiation (pigments, ultraviolet screening agents and carbon black), inhibit oxidation (antioxidants), to increase or decrease the viscosity of the matrix mix and or the release rate of the semiochemical (plasticizers). Devices may be prepared by casting the reactive matrix mixture in polymeric tubing or molds containing the polymer membrane. Layered or laminated devices may also be produced by casting the polyurethane reservoir on various barrier materials or membranes. For example a three layer laminate device might 2~L47078 consist of an aluminum foil barrier, a polyurethane layer containing the semiochemical (active ingredient AI) and a polyethylene membrane.
Hydroxy-terminated polybutadiene (poly BDTM) resins with a range of hydroxyl numbers and molecular weights are available. Those available from Atochem North America include the following poly BDT~ resins: R45M
(average molecular weight 2800 and hydroxyl value 0.73 meq/g), R45HT (average molecular weight 2800 and hydroxyl value 0.83 meq/g), R20LM (average molecular weight 1200 and hydroxyl value 1.7 meq/g), and 605 (an epoxidized hydroxyl-terminated polybutadiene with an oxirane content of 6.5% by weight and hydroxyl value of 2.7 meq/g). Poly BDTH resins alone or blended with polyether or polyester polyols are compatible with many classes of semiochemicals. Variation of the mixtures may be used to change the solubility parameter, hydrogen bonding and the extent of cross linking within the matrix by methods known in prior art. US patent 4,594,380 has indicated the use of hydroxy or carboxy-terminated copolymers of butadiene and acrylonitrile or styrene as agents to modify a poly BD~ based urethane release matrix. These materials are of high viscosity and are not easily incorporated into the matrix without considerable heating and the use of specialized mechanical mixing equipment. Of more utility are low viscosity hydroxy-terminated polyethers which may be used to modify the release matrix. Examples of low viscosity polyether polyols compatible with poly BDTM resins include polymers of proplene glycol such as PluracolT~ 220 (hydroxyl number 27), PluracolT~ 2010 (molecular weight 2000, hydroxyl number 56) both available from BASF Corporation, and AlkapolTM G-240 (molecular weight 700, hydroxyl number 240) available from Rhône-Poulenc Speciality Chemicals, Mississauga, Ontario).
Similar materials are available from several other manufacturers. The polyol component can also include materials to enhance the biodegradability of the matrix for ~''~' ' . " " .
.i .
example polycaprolactone diol or carbohydrate-based materials (cellulose esters and ethers).
The isocyanate component is generally an MDI with LupranateTM MM-103 (isocyanate con_ent 29.5% by weight available from BASF Corporation) and IsonateTM 143L (70-80% MDI and 20-30g6 polymerized MDI, available from Dow Chemical U.S.A.) as examples of suitable commercially available materials. Other isocyanates including toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate as well as other MDI blends can also be used in the process. The process generally requires no catalysis, however, catalysts known from prior art may be used with some of the slower reacting isocyanate/polyol combinations.
The general method for preparation of the polyurethane reservoir is based on the "one shot n batch protocol outlined for the reaction of poly BDT~ resins with MDI (Ryan 1971). Typical preparation of a semiochemical reservoir involves heating the polyol component and additives to 35-75 C with stirring at a vacuum of 15-100 mm to remove traces of volatile contaminants. The vessel is returned to ambient temperature and pressure and the semiochemical (0-80% w/w) is added to the mix. The mixture is stirred under vacuum until homogeneous. The isocyanate component is then added (isocyanate index 1.05) and stirring under vacuum is continued. The mixture is transferred to molds and left to polymerize. The time for polymerization can vary from a few minutes to several days and is accelerated by catalytic means or by curing at higher temperatures.
The polymeric matrix used for the reservoir is compatible with a large number of semiochemicals. The skilled practitioner will be aware that hundreds of semiochemicals are known and a complete listing herein of ~```- ' " ' ' ' ` , ' ' ~` ' '" . ' ,~' ~ ' ' ' ' , '` , ~ ,, ,~ k. .~ . ' ~
~: ` ' ' .. ...
21~7078 compounds compatible with the matrix is clearly impractical. Basically, all compatible semiochemicals as defined herein are feasible in the invention. Some examples demonstrating the range of active ingredients suited to incorporation into the composite polymer devices include: lepidopteran pheromones (E or Z-13-octadecenyl acetate, E or Z-ll-hexadecenal, E or Z-9-hexadecenal, hexadecanal, E or Z-11 hexadecenyl acetate,E or Z-9-hexadecenyl acetate, E or .Z-11-tetradecenal, E or Z-9-tetradecenal, tetradecanal, E or Z-ll-tetradecenyl acetate, E or Z-9-tetradecenyl acetate, E or Z-7-tetradecenyl acetate, E or Z-5-tetradecenyl acetate, E or Z-4-tridecenyl acetate, E or Z-9-dodecenyl acetate, E or Z-8-dodecenyl acetate, E or Z-5-dodecenyl acetate, dodecenyl acetate, 11-dodecenyl acetate, dodecyl acetate, E or Z-7-decenyl acetate, E or Z-5-decenyl acetate, E or Z-3-decenyl acetate, Z or E,Z or E 3,13-octadecadienyl acetate, Z,Z or Z,E-7,11-hexadecadienyl acetate, Z,E-9,12-tetradecadienyl acetate, E,E-4,10-dodecadienyl acetate, E,E-8,10-dodecadienyl acetate, Z-6-henicosen-11-one, 7,8-epoxy-2-methyloctadecane, Z,Z,Z-1,3,6,9-nonadecatetraene, 5,11-dimethylheptadecane, 2,5-dimethylheptadecane, 6-ethyl-2,3-dihydro-2-methyl-4H-pyran-4-one, phenylacetaldehyde, nonanal, undecanal, methy:L jasmonate), bark beetle kairomones (alpha-pinene, beta-pinene, terpinolene, limonene, 3-carene, p-cymene, myrcene, verbenene, camphene, camphor, longifolene, sabine:ne, beta-phellandrene, alpha-cubebene, allyl anisole, deca:nal, heptanal, E-2-hexenal, E-3-hexenal, hexanal), bark beetle pheromones (verbenone, 3-methyl-2-cyclohexenone, 3-methyl-3-cyclohexenone, frontalin, exo and endo-brevicomin, lineatin, multistriatin, chalcogran, 7-methyl-1,6-dioxaspiro[4.5]decane), pinocarvone, carvone, myrtenal, ipsenone, ipsdienone, 2-nona:none, grain beetle pheromones 35 (4,8-dimethyl-4(E),8(E)-decadienolide, 11-methyl-3(Z)-undecenolide, Z-3-dodecen-11-olide, Z,Z-3,6-dodecen-11-olide, Z-5-tetradecen-13-olide, Z,Z-5,8-tetradecen-13-:
~;~```'` ' 2`
-: . :
21470~8 olide), E-3-methyl-7-acetoxy-3-nonene], dermestid and tenebrionid beetle pheromones (Z-14-methyl-8-hexadecenal, 4,8-dimethyldecanal, gamma-caprolactone), curculionid beetle pheromones (pentadecanal, octadecanal, hexadecanol acetate, octadecanGl acetate, eicosanol acetate, 3,6,6-trimethylcyclohepta-2,4-dienone, chrysanthenone), apple maggot kairomones (hexyl acetate, E-2-hexenyl acetate, butyl-2-methylbutanoate, propylhexanoate, hexylpropanoate, butylhexanoate, hexylbutanoate), dipteran pheromones and synthetic attractants (Z-9-tricosene, Z-5-tricosene, Z-14-nonacosene, Z-13-nonacosene, Z-13-heptacosene, Z-9-heptacosene, 1,7-dioxaspiro[5.5]undecane, 2,8-dimethyl-1,7-dioxaspiro[5.5]undecane, 2-ethyl-7-methyl-1,6-dioxaspiro[4.5]decane, tert-butyl-4 (or 5)-chloro-2-methyl-cyclohexanecarboxylate, methyl eugenol, alpha-ionone, 4-(p-hydroxyphenyl)-2-butanone acetate), aphid pheromones (E-beta-farnasene, nepetalactone), homopteran pheromones (3-methyl-6-isopropenyl-9-decenyl acetate, Z-3-methyl-6-isopropenyl-3,9-decadienyl acetate, E or Z-3,7-dimethyl-2,7-octadecadienyl propionate, 3-methylene-7-methyl-7-octenyl propionate, 2,6-dimethyl-1,5-heptadien-3-ol acetate, Z-2,2-dimethyl-3-isopropenylcyclobutanemethanol acetate, E-6-isopropyl-3,9-dimethyl-5,8-decadienyl acetate), Japanese beetle pheromone and attractants( Z-5-(1-decenyl)dihydro-2(3H)-furanone, 2-phenethylpropionate), cockroach pheromones (3,11-dimethyl-2-nonacosanone, 8-m e t h y l e n e - 5 - (1 - m e t h y l e t h y l ) s p i r o [ 1 1 -oxabicyclo[8.1.0]undecene-2,2-oxiran]-3-one), mammal predator kairomones (2-propylthietane, 3-propyl-1,2-dithiolane, 3,3-dimethyl-1,2-dithiolane, 2,2-dimethylthietane, E or Z-2,4,5-trimethylthiazoline, 2-sec-butyl-2-thiazoline, isopentenyl methyl sulfide). It should be noted that some semiochemicals such as 2,4,5-trimethylthiazoline (with an imine functionality) or tertiary amines, although not reactive ~compatible) with the matrix, will act as catalytic agents in the polyurethane forming reaction. These materials are not ~, .... ..... . . .
k~ ' ' ' " ' :
~ :
-well suited to the batch method on a large scale, but are easily incorporated in a reaction injection moulding (RIM) process to produce devices.
The presence of a pol~mer membrane on the dispensers is significant feature of the technology of the invention. There are a great number of polymer membrane types commercially available. With this large selection, membrane materials can range from almost impermeable to highly permeable for most semiochemicals. The membrane material may be selected from polyvinyl chloride, PVC/vinyl copolymers, low and high density polyethylene, polyethylene/vinyl copolymers, polyvinyl acetate and copolymers, polyethylene terpthalate and copolymers, polypropylene, polyamide, polyimide, polyurethane, polyvinylidene fluoride, fluorinated ethylene proplyene polymers, polytetrafluoroethylene, silicone rubber, butyl rubber, neoprene rubber, isoprene rubber, cellulose acetate and laminated (co-extruded) membrane types (eg.
polyvinylchloride/fluorinated ethylene propylene polymers, polyethylene/vinyl acetate, polyethylene/polyethylene terpthalate and the like).
The composite polymer devices exhibit a characteristic release of semiochemical over time as demonstrated in Examples 1,3 and 5. After manufacture, devices are usually stored in vapour tight containers until they are needed. During this time the semiochemical approaches equilibrium concentrations in the matrix, the surrounding membrane and the atmosphere within the storage container (based on the solubility of the semiochemical in these various media). We have noted that when these dispensers are removed from storage, they exhibit a moderate to sharp initial decline in release rate as the semiochemical evaporates from the surface of the device.
This drop in release rate takes place over several hours or weeks and depends upon environmental conditions, the ~;~,~, . . .
.' ~,."
~'' - .
~ , .
2'1~7~78 volatility of the particular semiochemical and the type of matrix and membrane combination. Once diffusion of the semiochemical from the matrix to the surface of the membrane has taken place, however, we have found that the dispensers will release at more constant levels for prolonged periods. This period of relatively higher release has not hampered the use of these devices in dispensing anti-aggregation pheromones for tree protection or predator kairomones for mammal repellent applications or sex pheromones for mating disruption applications. When dispensers are produced for monitoring traps, they may be removed from storage and "pre-aged" prior to field deployment or the traps simply set out an appropriate time earlier than the anticipated flight of the pest.
A single manufacturing method may be used to produce several different types of release devices using the disclosed method, exemplified by the casting of the urethane matrix in PVC tubing. Short pieces of tubing (0.2-3.0 cm) can be cut and distributed by aircraft or other mechanical means for ground-based semiochemical dispensers in repellent or mating disruption applications.
Similarly, short pieces of the tubing serve as single point source semiochemical emitters used as lures in insect traps. Where point source emitters are not desired, long lengths of semiochemical loaded tubing may be used. For example several meters of loaded tubing may be attached to a tree to provide semiochemical release over a large area.
Long lengths of semiochemical-loaded tubing have advantages over devices with small reservoirs in that controlled and consistent semiochemical release is possible for extended periods of time. Devices prepared according to the invention are capable of controlling the release of AI in a wide range, from minute quantities (ng/day) to hundreds of milligrams or even grams of AI per day.
~ r ~_ ~,'~ , ' ' . ' ' ~'',' " ` ~ , ~1 4 707 8 Exam~le 1 This experiment demonstrates the effect of a membrane on the release characteristics of the bark beetle anti-aggregation pheromone verbenone from a polyurethane matrix. A matrix was prepared via the basic method outlined that contained 9.86~ (w/w) verbenone and a polyurethane composed of poly BD~ R45HT and LupranateTM MM-103. The mixture is allowed to polymerize in PVC tubing (0.5 mm thick and 4.8 mm diameter) for 16 hours at room temperature in a sealed polyethylene/nylon laminate bag.
The tubing is cut into 10 cm lengths and in one group of devices, the outer PVC membrane is carefully removed. Each device core contained a calculated load of approximately 100 mg of verbenone. Four replicates of the composite polymer devices and four (unsheathed) monolithic devices were aged in a controlled environment chamber at 30 C with an air flow through the chamber at a rate of 15 cfm.
Devices were weighed at day 0, day 3 and then at weekly intervals on a balance with a precision of 0.05 mg. The average cumulative weight loss per device was plotted against time in Figure 1. Since the devices each contained approximately lOOmg of AI, each mg of verbenone released was equivalent to 1% of the calculated load. The effect of the polymer membrane was dramatic, the composite devices released verbenone relatively smoothly throughout the test period. In contrast the monolithic devices had lost approximately 70% of the AI by day 3 and over 80% of the AI
by day 10. The monolithic devices were essentially exhausted after two weeks while the composite polymer devices had released approximately 25% of the AI after eight weeks. The composite polymer devices in this experiment were clearly superior in the controlled release of verbenone to the environment. It is known from other work not disclosed herein that composite polymer devices are capable of releasing 95% or more of the calculated AI
load, which is superior to many prior art devices.
~`~ .' ,r`
... .
,, 21~7078 Example 2 This experiment demonstrates the capability of the reservoir forming reaction to purify a crude semiochemical mixture in situ during the curing process.
The main components in the pheromone of Choristoneura fumiferana are E-ll-te~radecenal together with a small percentage of the Z isomer (Silk et al. 1980). The insect response to this pheromone blend is inhibited by E-ll-tetradecenol (Sanders 1972) which is often the synthetic precursor to the aldehyde and may be present as a contaminant in some batches of pheromone. A mixture of 34.2 mg of E-ll-tetradecenal (92.5~ E isomer, 5.3% Z
isomer, free of detectable alcoholsi and 4.7 mg of E~
tetradecenol (99% pure) was prepared and a sample subjected to capillary gas chromatography (GC). Under the conditions used, the ratio of peak areas of E-11-tetradecenol to E-ll-tetradecenal was 0.1322. Another sample of the aldehyde/alcohol mixture (approximately 2.0% w/w) was polymerized with 20% w/w of dioctyladipate and poly BDTH
- R45HT and LupranateT~ MM-103 (isocyanate index 1.1). After polymerization the resulting plug was loosened from the vial walls and extracted with five volumes of hexanes overnight. A sample of the extract was diluted six fold and subjected again to GC analysis. After this analysis the ratio of peak areas of E-11-tetradecenol to E-ll-tetradecenal was now 0.0049. The results demonstrate that approximately 96~ of the original E-ll-tetradecenol had been removed during the curing process. This example also serves to demonstrate why semiochemicals with active hydrogen donating groups are not compatible with this type of polyurethane reservoir.
Exampl~ 3 This example demonstrates that the composite ~' ' :. .
polymer devices have sustained release capabilities for a lepidopteran pheromone. The new dispensers are compared with prior art monolithic devices. A polymeric core formulated from poly BDT~ R45HT, IsonateT~ 143 L, 14.5~
dioctyladipate w/w and 1.37 ~ Z-ll-hexadecenal w/w as the active ingredient AI was cast into PVC tubing 4.8 mm diameter with 0.5 mm wall thickness. Cylinders 42mm long were cut from the tubing to form the devices used in this test. Devices were tethered to cotton plants and exposed to ambient conditions in Florida during August - October 1991. Sample devices were collected at weekly intervals, sealed in nylon polyethylene laminate bags and stored at 5 C or lower until analysis. Samples consisting of three devices were repeatedly extracted with hexanes, the extracts were pooled, treated with hexadecane as an internal standard and analyzed by capillary column gas chromatography. The extracts were analyzed for AI and Z-11-Hexadecenoic acid, an expected oxidation product of the AI. The results of the residue analysis are graphed as a function over time in Figure 1. Results from similarly shaped PVC monolithic devices are included for comparison in Figure 1. The results demonstrate that the urethane cored device controls the release of AI and also affords some protection of the pheromone from oxidation. Except for an initial moderate drop in the residue weights in the first two weeks, the devices exhibit a smooth release of AI
for over 60 days under relatively high temperature field conditions. Such a device is potentially useful for mating disruption of Heliocoverpa (Heliothis) species.
ExamDle 4 In this example composite polymer lures were compared with two types of monolithic PVC lures in sticky traps. The biological assay was conducted at sites in Oregon, Washington, California and Idaho in 1991. The devices were 4 mm diameter with a wall thickness of 0.5 mm ....~
~` .
.,.
with a core composition containing poly BDTH R45HT, IsonateTM
143L, 50% w/w dioctyladipate and 0.001 % w/w of Z-6-henicosen-11-one as AI. The PVC devices were 5 mm long and the urethane cored devices were 8 mm long, with all devices containing equivalent weights (approximately 500 ng each) of AI. The results of this test are shown in Table 1.
Lure Type PVC 1 PVC 2COMPOSITE
#of sites (4 blocks/site) 27 27 27 Sum of avg # insects 414.~2 596.0068~.83 t~appedrDlock Avg # insects trappedlblock 15.37 22.07 25.40 I Standard Deviation 123.63 j23.71 24.66 I Maximum # ~apped/block 1 87.50 81.75 75.75 The results demonstrate that composite polymer devices show good biological activity and no inhibitors of the biological response were present. These devices are useful as an early warning monitoring tool for detecting Douglas-Fir tussock moth populations.
Exampl~ 5 In this example two different urethane semiochemical blends were prepared and polymerized in 5.2 x 10.0 cm bags made with an vinyl acetate/ ethylene copolymer membrane, 12 micron thick. After loading with semiochemical and polymer, the packages were heat sealed and allowed to polymerize. Packages were made to contain 5.0 g each of verbenone as the semiochemical. Sample A
packages contained 80% verbenone w/w and 20% polyurethane prepared from poly BDTH R45HT and Lupranate~ MM-103. Sample B packages contained 20% verbenone w/w and 80~ polyurethane prepared from poly BDT~ R20LM and lupranateTH MM-103. The ..`; .
.. .:
....
.,. ; , `~' '. :
.. . .
^`- 21~7078 devices were aged in a temperature controlled chamber at 24 C with a flow of air through the chamber of 15 cfm.
Release rate of semiochemical from the devices was determined by weight loss. The observed mean release of verbenone from these devices over time is shown in Figure 3. The results demonstrate that resin type and pheromone load can substantially alter the release rate characteristics of these devices. Devices such as these are useful for dispensing anti-aggregation pheromones of bark beetles.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of this invention is to be construed in accordance with the substance defined by the following claims.
-~,.`' ;.-~`
,.
Polyurethane chemistry and polymers are well known and widely distributed in the plastics industry, - however the use of these polymers in semiochemical slow release devices has been limited to silicone-urethane copolymers. The terminology used herein to describe the reactants and the reactive process to produce a polyurethane semiochemical reservoir conforms to the customary meanings as given in "Polyurethane Handbook" ed.
G. Oertel, Hanser Publishers or "The ICI Polyurethanes Book", 2nd Edition, ed. G. Woods, ICI Polyurethanes and John Wiley & Sons. The term "polyol" refers to a molecule with at least two hydroxyl groups. Polymeric polyols usually contain other chemical functionalities and the most common types of polyols used in polyurethane manufacture are polyether polyols (hydroxy-terminated polyethers) and polyester polyols (hydroxy-terminated polyesters).
Generally, polymeric polyols are not pure compounds, but rather mixtures which are usually characterized by the l214707~
average properties of the mixture. The isocyanates described herein are molecules wnich contain at least two isocyanate groups. The term MDI refers to diphenylmethane diisocyanate (predominately 4,4l isomer) which is commonly used in industry as mixtures of pure MDI and polymeric MDI.
SUI~RY OF THE INVENTION
The invention is directed to semiochemical release devices composed of a polyurethane matrix containing an active agent and which is at least partially surrounded by a polymer membrane. The polyurethane matrix is prepared from a reactive mixture comprising a polyol and an isocyanate cross linking agent in the presence of unreactive semiochemicals and additives.
AS defined herein, the expression "semiochemical"
means and includes substances which transmit signals to members of the same species as well as different species.
These semiochemical substances include, inter alia, pure chemicals, blends of chemicals, and chemicals which mimic the biological actions of semiochemicals.
-: -The polyol may be selected from the group consisting of hydroxy-terminated polybutadiene resins, polyether polyols, polyester polyols and mixtures thereof.
The isocyanate component may be selected from the group consisting of monomeric or polymeric diphenylmethane diisocyanates, toluene diisocyanates, isophorone diisocyanate and monomeric or polymeric hexamethylene diisocyanate or mixtures thereof. Semiochemicals compatible with the reactive process may be selected from the functional groups including: alkanes, alkenes, aromatic hydrocarbons, ethers, esters, epoxides, aldehydes, ketones, lactones, nitriles, imines, tertiary amines, thioethers, sulfoxides, sulfones, disulfide compounds, thioesters, orgar.ohalides, and mixtures thereof. Semiochemicals not ~.,' . .-'. .',~; . ~, ' .` . . :
~,. . ; . . ., : ' :
ccmpatible or reactive with the matrix include the functional groups: alcohols, phenols, carboxylic acids, thiols, primary and secondary amines, and amides.
The polyurethane matrix reaction mixture may include anti-oxidants, ultraviolet light absorbers, pigments, dyes, fillers, blowing agents, plasticizers, other resin modifying agents and mixtures thereof, which protect the matrix from aging and weathering and add other desirable characteristics to the matrix.
The reaction mixture is polymerized in a device at least partially surrounded by a polymer layer selected from the group consisting of: polyvinyl chloride (PVC), PVC/vinyl copolymers, low and high density polyethylene, polyethylene/vinyl copolymers, polyvinyl acetate and copolymers, polyethylene terpthalate and copolymers, polypropylene, polyamide, polyimide, polyurethane, polyvinylidene fluoride, fluorinated ethylene proplyene polymers, polytetrafluoroethylene, silicone rubber, butyl rubber, neoprene rubber, isoprene rubber, cellulose acetate and laminated (co-extruded) membrane types (eg.
PVC/fluorinated ethylene propylene polymers, polyethylene/
vinyl acetate, polyethylene/polyethylene terpthalate and the like).
A preferred embodiment of the invention comprises casting the reactive urethane mixture in polymeric tubing and using the tubing as long cylinders, or cut into short cylinders, which serve as semiochemical dispensers.
A semiochemical controlled release dispenser comprising: (a) a polyurethane core formed from a polyol, a polymeric isocyanate and a semiochemical; and (b) a polymeric tubing surrounding a portion of the core.
The semiochemical concentration in the said ~;~
~` .
reservoir can be between about 0.001~ and 80~ by weight of the reservoir. The active ingxedient can be a synthetic behaviour-modifing semiochemical mimic chemical, or a natural or synthetically prepared semiochemical.
DRAWINGS
In the drawings, which represent specific embodiments of the invention, but which should not be regarded as restricting the spirit or scope of the invention in any way:
Figure 1 illustrates a graph which demonstrates cumulative verbenone release at 30 C from urethane lS monolithic devices compared with identical urethane cores partially surrounded by a PVC membrane.
Figure 2 illustrates a graph of average retained Z-11-hexadecenal residue per device aged in a Florida cotton field as a function over time. Figure 2 includes similarly shaped PVC monolithic devices for comparison.
Figure 3 illustrates a plot of mean release rate (mg/day/device) of verbenone from composite polymer release devices according to the invention, as a function of time.
DETAILED DESCRIPTION OF SPECIFIC
EMBODIMENTS OF THE INVENTION
The invention consists of versatile composite polymer devices used for dispensing semiochemicals.
Hydroxy-terminated polybutadiene resins and/or other polyols an be combined with additives, semiochemical(s), and an isocyanate component to produce controlled-release reservoirs. By varying the semiochemical load, the cross-linking density of the polymer matrix, the presence of various resin additives, as well as the type of membrane, ~,~ ;. ., . . . ~ ' 21470~8 a wide variety of required release characteristics can be obtained. Semiochemical dispensers, according to the invention, can be produced under very mild conditions using a simple process that is readily adapted to automated production of a variety of device forms. A qualifying limitation of the invention is that the reaction chemistry which forms the device matrix is not compatible with semiochemicals that have active hydrogen donating groups.
This invention represents a significant improvement in several aspects over semiochemical dispensers described in prior art. The process used to produce devices may be conducted at room temperature and this represents an energy saving over processes using thermal curing (Fitzgerald et al. 1973 and Czechoslovakian patent 8490), melting polymers during semiochemical loading (US patents 4908208 and 5008115) or radiation curing methods (Kim et al. 1988 and Smith et al. 1991). Moreover, sin^e expensive volatile semiochemicals may be lost during thermal processing, the current technology offers further advantages over this type of prior art.
The invention allows the formation of a semiochemical reservoir in a single step whereas many systems prepared using prior art techniques, involve formation of the reservoir or matrix first and then loading a semiochemical. The technology of the invention differs from these devîces in that the semiochemical is incorporated during the polymerization of the matrix.
The subject invention is ~n improvement over prior art monolithic polyurethane or silicone polyurethane copolymer matrices (US patents 4594380, 4908208, and 5008115 ), since the new devices of the invention comprise reservoir systems bounded, at least in part, by a rate-controlling membrane. A wide selection of rate-controlling membrane types is complemented by the ability ~,.
~`:
.
,`!~ ~ .
~' .
2:147078 to vary the semiochemical permeability characteristics of the reservoir. This combination allows the composite polymer devices better controlled release of semiochemicals than can usually be attained using monolithic devices.
Comparisons of the new devices and prior art monolithic dispensers are shown in Examples 1, 3 and 4. The membrane of the composite devices has further advantages over monolithic devices since it also serves to screen out ultraviolet light and limit exposure to oxygen, both of which may contribute to semiochemical degradation in the matrix.
Although the invention as described is not suited to the release of semiochemicals with active hydrogen donating groups, this reactivity can be used to purify relatively crude semiochemicals in situ. Impurities of this nature can be trapped by chemical reaction with the isocyanate component during curing of the matrix. This method avoids the need for additional purification of semiochemicals containing low concentrations of impurities with hydroxyl, carboxyl, sulfhydryl and amino functional groups. Example 2 demonstrates this principle.
The physical form of the subject invention can be highly variable. For example, fillers or blowing agents may be included in the matrix formulation to produce a reservoir where a high surface area is desired. Additives may be used to absorb or reflect radiation (pigments, ultraviolet screening agents and carbon black), inhibit oxidation (antioxidants), to increase or decrease the viscosity of the matrix mix and or the release rate of the semiochemical (plasticizers). Devices may be prepared by casting the reactive matrix mixture in polymeric tubing or molds containing the polymer membrane. Layered or laminated devices may also be produced by casting the polyurethane reservoir on various barrier materials or membranes. For example a three layer laminate device might 2~L47078 consist of an aluminum foil barrier, a polyurethane layer containing the semiochemical (active ingredient AI) and a polyethylene membrane.
Hydroxy-terminated polybutadiene (poly BDTM) resins with a range of hydroxyl numbers and molecular weights are available. Those available from Atochem North America include the following poly BDT~ resins: R45M
(average molecular weight 2800 and hydroxyl value 0.73 meq/g), R45HT (average molecular weight 2800 and hydroxyl value 0.83 meq/g), R20LM (average molecular weight 1200 and hydroxyl value 1.7 meq/g), and 605 (an epoxidized hydroxyl-terminated polybutadiene with an oxirane content of 6.5% by weight and hydroxyl value of 2.7 meq/g). Poly BDTH resins alone or blended with polyether or polyester polyols are compatible with many classes of semiochemicals. Variation of the mixtures may be used to change the solubility parameter, hydrogen bonding and the extent of cross linking within the matrix by methods known in prior art. US patent 4,594,380 has indicated the use of hydroxy or carboxy-terminated copolymers of butadiene and acrylonitrile or styrene as agents to modify a poly BD~ based urethane release matrix. These materials are of high viscosity and are not easily incorporated into the matrix without considerable heating and the use of specialized mechanical mixing equipment. Of more utility are low viscosity hydroxy-terminated polyethers which may be used to modify the release matrix. Examples of low viscosity polyether polyols compatible with poly BDTM resins include polymers of proplene glycol such as PluracolT~ 220 (hydroxyl number 27), PluracolT~ 2010 (molecular weight 2000, hydroxyl number 56) both available from BASF Corporation, and AlkapolTM G-240 (molecular weight 700, hydroxyl number 240) available from Rhône-Poulenc Speciality Chemicals, Mississauga, Ontario).
Similar materials are available from several other manufacturers. The polyol component can also include materials to enhance the biodegradability of the matrix for ~''~' ' . " " .
.i .
example polycaprolactone diol or carbohydrate-based materials (cellulose esters and ethers).
The isocyanate component is generally an MDI with LupranateTM MM-103 (isocyanate con_ent 29.5% by weight available from BASF Corporation) and IsonateTM 143L (70-80% MDI and 20-30g6 polymerized MDI, available from Dow Chemical U.S.A.) as examples of suitable commercially available materials. Other isocyanates including toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate as well as other MDI blends can also be used in the process. The process generally requires no catalysis, however, catalysts known from prior art may be used with some of the slower reacting isocyanate/polyol combinations.
The general method for preparation of the polyurethane reservoir is based on the "one shot n batch protocol outlined for the reaction of poly BDT~ resins with MDI (Ryan 1971). Typical preparation of a semiochemical reservoir involves heating the polyol component and additives to 35-75 C with stirring at a vacuum of 15-100 mm to remove traces of volatile contaminants. The vessel is returned to ambient temperature and pressure and the semiochemical (0-80% w/w) is added to the mix. The mixture is stirred under vacuum until homogeneous. The isocyanate component is then added (isocyanate index 1.05) and stirring under vacuum is continued. The mixture is transferred to molds and left to polymerize. The time for polymerization can vary from a few minutes to several days and is accelerated by catalytic means or by curing at higher temperatures.
The polymeric matrix used for the reservoir is compatible with a large number of semiochemicals. The skilled practitioner will be aware that hundreds of semiochemicals are known and a complete listing herein of ~```- ' " ' ' ' ` , ' ' ~` ' '" . ' ,~' ~ ' ' ' ' , '` , ~ ,, ,~ k. .~ . ' ~
~: ` ' ' .. ...
21~7078 compounds compatible with the matrix is clearly impractical. Basically, all compatible semiochemicals as defined herein are feasible in the invention. Some examples demonstrating the range of active ingredients suited to incorporation into the composite polymer devices include: lepidopteran pheromones (E or Z-13-octadecenyl acetate, E or Z-ll-hexadecenal, E or Z-9-hexadecenal, hexadecanal, E or Z-11 hexadecenyl acetate,E or Z-9-hexadecenyl acetate, E or .Z-11-tetradecenal, E or Z-9-tetradecenal, tetradecanal, E or Z-ll-tetradecenyl acetate, E or Z-9-tetradecenyl acetate, E or Z-7-tetradecenyl acetate, E or Z-5-tetradecenyl acetate, E or Z-4-tridecenyl acetate, E or Z-9-dodecenyl acetate, E or Z-8-dodecenyl acetate, E or Z-5-dodecenyl acetate, dodecenyl acetate, 11-dodecenyl acetate, dodecyl acetate, E or Z-7-decenyl acetate, E or Z-5-decenyl acetate, E or Z-3-decenyl acetate, Z or E,Z or E 3,13-octadecadienyl acetate, Z,Z or Z,E-7,11-hexadecadienyl acetate, Z,E-9,12-tetradecadienyl acetate, E,E-4,10-dodecadienyl acetate, E,E-8,10-dodecadienyl acetate, Z-6-henicosen-11-one, 7,8-epoxy-2-methyloctadecane, Z,Z,Z-1,3,6,9-nonadecatetraene, 5,11-dimethylheptadecane, 2,5-dimethylheptadecane, 6-ethyl-2,3-dihydro-2-methyl-4H-pyran-4-one, phenylacetaldehyde, nonanal, undecanal, methy:L jasmonate), bark beetle kairomones (alpha-pinene, beta-pinene, terpinolene, limonene, 3-carene, p-cymene, myrcene, verbenene, camphene, camphor, longifolene, sabine:ne, beta-phellandrene, alpha-cubebene, allyl anisole, deca:nal, heptanal, E-2-hexenal, E-3-hexenal, hexanal), bark beetle pheromones (verbenone, 3-methyl-2-cyclohexenone, 3-methyl-3-cyclohexenone, frontalin, exo and endo-brevicomin, lineatin, multistriatin, chalcogran, 7-methyl-1,6-dioxaspiro[4.5]decane), pinocarvone, carvone, myrtenal, ipsenone, ipsdienone, 2-nona:none, grain beetle pheromones 35 (4,8-dimethyl-4(E),8(E)-decadienolide, 11-methyl-3(Z)-undecenolide, Z-3-dodecen-11-olide, Z,Z-3,6-dodecen-11-olide, Z-5-tetradecen-13-olide, Z,Z-5,8-tetradecen-13-:
~;~```'` ' 2`
-: . :
21470~8 olide), E-3-methyl-7-acetoxy-3-nonene], dermestid and tenebrionid beetle pheromones (Z-14-methyl-8-hexadecenal, 4,8-dimethyldecanal, gamma-caprolactone), curculionid beetle pheromones (pentadecanal, octadecanal, hexadecanol acetate, octadecanGl acetate, eicosanol acetate, 3,6,6-trimethylcyclohepta-2,4-dienone, chrysanthenone), apple maggot kairomones (hexyl acetate, E-2-hexenyl acetate, butyl-2-methylbutanoate, propylhexanoate, hexylpropanoate, butylhexanoate, hexylbutanoate), dipteran pheromones and synthetic attractants (Z-9-tricosene, Z-5-tricosene, Z-14-nonacosene, Z-13-nonacosene, Z-13-heptacosene, Z-9-heptacosene, 1,7-dioxaspiro[5.5]undecane, 2,8-dimethyl-1,7-dioxaspiro[5.5]undecane, 2-ethyl-7-methyl-1,6-dioxaspiro[4.5]decane, tert-butyl-4 (or 5)-chloro-2-methyl-cyclohexanecarboxylate, methyl eugenol, alpha-ionone, 4-(p-hydroxyphenyl)-2-butanone acetate), aphid pheromones (E-beta-farnasene, nepetalactone), homopteran pheromones (3-methyl-6-isopropenyl-9-decenyl acetate, Z-3-methyl-6-isopropenyl-3,9-decadienyl acetate, E or Z-3,7-dimethyl-2,7-octadecadienyl propionate, 3-methylene-7-methyl-7-octenyl propionate, 2,6-dimethyl-1,5-heptadien-3-ol acetate, Z-2,2-dimethyl-3-isopropenylcyclobutanemethanol acetate, E-6-isopropyl-3,9-dimethyl-5,8-decadienyl acetate), Japanese beetle pheromone and attractants( Z-5-(1-decenyl)dihydro-2(3H)-furanone, 2-phenethylpropionate), cockroach pheromones (3,11-dimethyl-2-nonacosanone, 8-m e t h y l e n e - 5 - (1 - m e t h y l e t h y l ) s p i r o [ 1 1 -oxabicyclo[8.1.0]undecene-2,2-oxiran]-3-one), mammal predator kairomones (2-propylthietane, 3-propyl-1,2-dithiolane, 3,3-dimethyl-1,2-dithiolane, 2,2-dimethylthietane, E or Z-2,4,5-trimethylthiazoline, 2-sec-butyl-2-thiazoline, isopentenyl methyl sulfide). It should be noted that some semiochemicals such as 2,4,5-trimethylthiazoline (with an imine functionality) or tertiary amines, although not reactive ~compatible) with the matrix, will act as catalytic agents in the polyurethane forming reaction. These materials are not ~, .... ..... . . .
k~ ' ' ' " ' :
~ :
-well suited to the batch method on a large scale, but are easily incorporated in a reaction injection moulding (RIM) process to produce devices.
The presence of a pol~mer membrane on the dispensers is significant feature of the technology of the invention. There are a great number of polymer membrane types commercially available. With this large selection, membrane materials can range from almost impermeable to highly permeable for most semiochemicals. The membrane material may be selected from polyvinyl chloride, PVC/vinyl copolymers, low and high density polyethylene, polyethylene/vinyl copolymers, polyvinyl acetate and copolymers, polyethylene terpthalate and copolymers, polypropylene, polyamide, polyimide, polyurethane, polyvinylidene fluoride, fluorinated ethylene proplyene polymers, polytetrafluoroethylene, silicone rubber, butyl rubber, neoprene rubber, isoprene rubber, cellulose acetate and laminated (co-extruded) membrane types (eg.
polyvinylchloride/fluorinated ethylene propylene polymers, polyethylene/vinyl acetate, polyethylene/polyethylene terpthalate and the like).
The composite polymer devices exhibit a characteristic release of semiochemical over time as demonstrated in Examples 1,3 and 5. After manufacture, devices are usually stored in vapour tight containers until they are needed. During this time the semiochemical approaches equilibrium concentrations in the matrix, the surrounding membrane and the atmosphere within the storage container (based on the solubility of the semiochemical in these various media). We have noted that when these dispensers are removed from storage, they exhibit a moderate to sharp initial decline in release rate as the semiochemical evaporates from the surface of the device.
This drop in release rate takes place over several hours or weeks and depends upon environmental conditions, the ~;~,~, . . .
.' ~,."
~'' - .
~ , .
2'1~7~78 volatility of the particular semiochemical and the type of matrix and membrane combination. Once diffusion of the semiochemical from the matrix to the surface of the membrane has taken place, however, we have found that the dispensers will release at more constant levels for prolonged periods. This period of relatively higher release has not hampered the use of these devices in dispensing anti-aggregation pheromones for tree protection or predator kairomones for mammal repellent applications or sex pheromones for mating disruption applications. When dispensers are produced for monitoring traps, they may be removed from storage and "pre-aged" prior to field deployment or the traps simply set out an appropriate time earlier than the anticipated flight of the pest.
A single manufacturing method may be used to produce several different types of release devices using the disclosed method, exemplified by the casting of the urethane matrix in PVC tubing. Short pieces of tubing (0.2-3.0 cm) can be cut and distributed by aircraft or other mechanical means for ground-based semiochemical dispensers in repellent or mating disruption applications.
Similarly, short pieces of the tubing serve as single point source semiochemical emitters used as lures in insect traps. Where point source emitters are not desired, long lengths of semiochemical loaded tubing may be used. For example several meters of loaded tubing may be attached to a tree to provide semiochemical release over a large area.
Long lengths of semiochemical-loaded tubing have advantages over devices with small reservoirs in that controlled and consistent semiochemical release is possible for extended periods of time. Devices prepared according to the invention are capable of controlling the release of AI in a wide range, from minute quantities (ng/day) to hundreds of milligrams or even grams of AI per day.
~ r ~_ ~,'~ , ' ' . ' ' ~'',' " ` ~ , ~1 4 707 8 Exam~le 1 This experiment demonstrates the effect of a membrane on the release characteristics of the bark beetle anti-aggregation pheromone verbenone from a polyurethane matrix. A matrix was prepared via the basic method outlined that contained 9.86~ (w/w) verbenone and a polyurethane composed of poly BD~ R45HT and LupranateTM MM-103. The mixture is allowed to polymerize in PVC tubing (0.5 mm thick and 4.8 mm diameter) for 16 hours at room temperature in a sealed polyethylene/nylon laminate bag.
The tubing is cut into 10 cm lengths and in one group of devices, the outer PVC membrane is carefully removed. Each device core contained a calculated load of approximately 100 mg of verbenone. Four replicates of the composite polymer devices and four (unsheathed) monolithic devices were aged in a controlled environment chamber at 30 C with an air flow through the chamber at a rate of 15 cfm.
Devices were weighed at day 0, day 3 and then at weekly intervals on a balance with a precision of 0.05 mg. The average cumulative weight loss per device was plotted against time in Figure 1. Since the devices each contained approximately lOOmg of AI, each mg of verbenone released was equivalent to 1% of the calculated load. The effect of the polymer membrane was dramatic, the composite devices released verbenone relatively smoothly throughout the test period. In contrast the monolithic devices had lost approximately 70% of the AI by day 3 and over 80% of the AI
by day 10. The monolithic devices were essentially exhausted after two weeks while the composite polymer devices had released approximately 25% of the AI after eight weeks. The composite polymer devices in this experiment were clearly superior in the controlled release of verbenone to the environment. It is known from other work not disclosed herein that composite polymer devices are capable of releasing 95% or more of the calculated AI
load, which is superior to many prior art devices.
~`~ .' ,r`
... .
,, 21~7078 Example 2 This experiment demonstrates the capability of the reservoir forming reaction to purify a crude semiochemical mixture in situ during the curing process.
The main components in the pheromone of Choristoneura fumiferana are E-ll-te~radecenal together with a small percentage of the Z isomer (Silk et al. 1980). The insect response to this pheromone blend is inhibited by E-ll-tetradecenol (Sanders 1972) which is often the synthetic precursor to the aldehyde and may be present as a contaminant in some batches of pheromone. A mixture of 34.2 mg of E-ll-tetradecenal (92.5~ E isomer, 5.3% Z
isomer, free of detectable alcoholsi and 4.7 mg of E~
tetradecenol (99% pure) was prepared and a sample subjected to capillary gas chromatography (GC). Under the conditions used, the ratio of peak areas of E-11-tetradecenol to E-ll-tetradecenal was 0.1322. Another sample of the aldehyde/alcohol mixture (approximately 2.0% w/w) was polymerized with 20% w/w of dioctyladipate and poly BDTH
- R45HT and LupranateT~ MM-103 (isocyanate index 1.1). After polymerization the resulting plug was loosened from the vial walls and extracted with five volumes of hexanes overnight. A sample of the extract was diluted six fold and subjected again to GC analysis. After this analysis the ratio of peak areas of E-11-tetradecenol to E-ll-tetradecenal was now 0.0049. The results demonstrate that approximately 96~ of the original E-ll-tetradecenol had been removed during the curing process. This example also serves to demonstrate why semiochemicals with active hydrogen donating groups are not compatible with this type of polyurethane reservoir.
Exampl~ 3 This example demonstrates that the composite ~' ' :. .
polymer devices have sustained release capabilities for a lepidopteran pheromone. The new dispensers are compared with prior art monolithic devices. A polymeric core formulated from poly BDT~ R45HT, IsonateT~ 143 L, 14.5~
dioctyladipate w/w and 1.37 ~ Z-ll-hexadecenal w/w as the active ingredient AI was cast into PVC tubing 4.8 mm diameter with 0.5 mm wall thickness. Cylinders 42mm long were cut from the tubing to form the devices used in this test. Devices were tethered to cotton plants and exposed to ambient conditions in Florida during August - October 1991. Sample devices were collected at weekly intervals, sealed in nylon polyethylene laminate bags and stored at 5 C or lower until analysis. Samples consisting of three devices were repeatedly extracted with hexanes, the extracts were pooled, treated with hexadecane as an internal standard and analyzed by capillary column gas chromatography. The extracts were analyzed for AI and Z-11-Hexadecenoic acid, an expected oxidation product of the AI. The results of the residue analysis are graphed as a function over time in Figure 1. Results from similarly shaped PVC monolithic devices are included for comparison in Figure 1. The results demonstrate that the urethane cored device controls the release of AI and also affords some protection of the pheromone from oxidation. Except for an initial moderate drop in the residue weights in the first two weeks, the devices exhibit a smooth release of AI
for over 60 days under relatively high temperature field conditions. Such a device is potentially useful for mating disruption of Heliocoverpa (Heliothis) species.
ExamDle 4 In this example composite polymer lures were compared with two types of monolithic PVC lures in sticky traps. The biological assay was conducted at sites in Oregon, Washington, California and Idaho in 1991. The devices were 4 mm diameter with a wall thickness of 0.5 mm ....~
~` .
.,.
with a core composition containing poly BDTH R45HT, IsonateTM
143L, 50% w/w dioctyladipate and 0.001 % w/w of Z-6-henicosen-11-one as AI. The PVC devices were 5 mm long and the urethane cored devices were 8 mm long, with all devices containing equivalent weights (approximately 500 ng each) of AI. The results of this test are shown in Table 1.
Lure Type PVC 1 PVC 2COMPOSITE
#of sites (4 blocks/site) 27 27 27 Sum of avg # insects 414.~2 596.0068~.83 t~appedrDlock Avg # insects trappedlblock 15.37 22.07 25.40 I Standard Deviation 123.63 j23.71 24.66 I Maximum # ~apped/block 1 87.50 81.75 75.75 The results demonstrate that composite polymer devices show good biological activity and no inhibitors of the biological response were present. These devices are useful as an early warning monitoring tool for detecting Douglas-Fir tussock moth populations.
Exampl~ 5 In this example two different urethane semiochemical blends were prepared and polymerized in 5.2 x 10.0 cm bags made with an vinyl acetate/ ethylene copolymer membrane, 12 micron thick. After loading with semiochemical and polymer, the packages were heat sealed and allowed to polymerize. Packages were made to contain 5.0 g each of verbenone as the semiochemical. Sample A
packages contained 80% verbenone w/w and 20% polyurethane prepared from poly BDTH R45HT and Lupranate~ MM-103. Sample B packages contained 20% verbenone w/w and 80~ polyurethane prepared from poly BDT~ R20LM and lupranateTH MM-103. The ..`; .
.. .:
....
.,. ; , `~' '. :
.. . .
^`- 21~7078 devices were aged in a temperature controlled chamber at 24 C with a flow of air through the chamber of 15 cfm.
Release rate of semiochemical from the devices was determined by weight loss. The observed mean release of verbenone from these devices over time is shown in Figure 3. The results demonstrate that resin type and pheromone load can substantially alter the release rate characteristics of these devices. Devices such as these are useful for dispensing anti-aggregation pheromones of bark beetles.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of this invention is to be construed in accordance with the substance defined by the following claims.
-~,.`' ;.-~`
,.
Claims (16)
1. A semiochemical controlled release dispenser comprising:
(a) a polyurethane reservoir formed from a reaction mixture of a polyol, an isocyanate and as an active ingredient an unreactive semiochemical; and (b) a polymeric membrane that covers at least a part of the reservoir.
(a) a polyurethane reservoir formed from a reaction mixture of a polyol, an isocyanate and as an active ingredient an unreactive semiochemical; and (b) a polymeric membrane that covers at least a part of the reservoir.
2. A semiochemical controlled release dispenser according to claim 1 wherein the reservoir is in the form of a cylinder and the membrane is in the form of a tube covering at least a portion of the cylinder.
3. A semiochemical controlled release dispenser comprising:
(a) a polyurethane reservoir formed from a reaction mixture of (i) a polyol selected from the group consisting of hydroxy-terminated polybutadiene, hydroxy-terminated polyether and hydroxy-terminated polyester;
(ii) an isocyanate component selected from the group consisting of monomeric or polymeric diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and polymeric hexamethylene diisocyanate;
(iii) an active ingredient comprising an unreactive semiochemical selected from the functional groups consisting of alkanes, alkenes, aromatic hydrocarbons, ethers, esters, epoxides, aldehydes, ketones, lactones, nitriles, imines, tertiary amines, thioethers, sulfoxides, sulfones, disulfide compounds, thioesters, organohalides, and mixtures thereof; and (b) a surrounding polymeric membrane covering at least a portion of the polyurethane reservoir, said membrane being selected from the group consisting of polyvinylchloride, polyvinylchloride/vinyl copolymers, low and high density polyethylene, polyethylene/vinyl copolymers, polyvinyl acetate and copolymers, polyethylene terpthalate and copolymers, polypropylene, polyamide, polyimide, polyurethane, polyvinylidene fluoride, fluorinated ethylene propylene polymers, polytetrafluoroethylene, silicone rubber, butyl rubber, neoprene rubber, isoprene rubber, cellulose acetate, laminated and (co-extruded) membranes, polyvinylchloride/
fluorinated ethylene propylene polymers, polyethylene/
vinyl acetate and polyethylene/polyethylene terpthalate.
(a) a polyurethane reservoir formed from a reaction mixture of (i) a polyol selected from the group consisting of hydroxy-terminated polybutadiene, hydroxy-terminated polyether and hydroxy-terminated polyester;
(ii) an isocyanate component selected from the group consisting of monomeric or polymeric diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and polymeric hexamethylene diisocyanate;
(iii) an active ingredient comprising an unreactive semiochemical selected from the functional groups consisting of alkanes, alkenes, aromatic hydrocarbons, ethers, esters, epoxides, aldehydes, ketones, lactones, nitriles, imines, tertiary amines, thioethers, sulfoxides, sulfones, disulfide compounds, thioesters, organohalides, and mixtures thereof; and (b) a surrounding polymeric membrane covering at least a portion of the polyurethane reservoir, said membrane being selected from the group consisting of polyvinylchloride, polyvinylchloride/vinyl copolymers, low and high density polyethylene, polyethylene/vinyl copolymers, polyvinyl acetate and copolymers, polyethylene terpthalate and copolymers, polypropylene, polyamide, polyimide, polyurethane, polyvinylidene fluoride, fluorinated ethylene propylene polymers, polytetrafluoroethylene, silicone rubber, butyl rubber, neoprene rubber, isoprene rubber, cellulose acetate, laminated and (co-extruded) membranes, polyvinylchloride/
fluorinated ethylene propylene polymers, polyethylene/
vinyl acetate and polyethylene/polyethylene terpthalate.
4. A semiochemical controlled release dispenser according to claim 3 wherein the reservoir forming mixture includes substances selected from the group consisting of anti-oxidants, ultraviolet light absorbers, pigments, dyes, fillers, blowing agents, and plasticizers.
5. A semiochemical controlled release dispenser according to claim 3 wherein the semiochemical concentration in the said reservoir is between about 0.001%
and 80% by weight of the reservoir.
and 80% by weight of the reservoir.
6. A semiochemical controlled release dispenser according to claim 3 wherein the reservoir is in the form of a cylinder and the membrane is in the form of a tube covering at least a portion of the cylinder.
7. A semiochemical controlled release dispenser comprising:
(a) a cylindrical polyurethane core formed from a polyol, a diisocyanate, and as an active ingredient at least one unreactive semiochemical; and (b) an active ingredient release rate controlling membrane comprised of polymeric tubing enclosing at least a portion of the core.
(a) a cylindrical polyurethane core formed from a polyol, a diisocyanate, and as an active ingredient at least one unreactive semiochemical; and (b) an active ingredient release rate controlling membrane comprised of polymeric tubing enclosing at least a portion of the core.
8. A controlled release dispenser according to claim 1 wherein the active ingredient is a synthetic behaviour-modifing semiochemical mimic chemical.
9. A controlled release dispenser according to claim 3 wherein the active ingredient is a synthetic behavoir-modifying semiochemical mimic chemical.
10. A controlled release dispenser according to claim 5 wherein the active ingedient is a synthetic behavior-modifying semiochemical mimic chemical.
11. A controlled release dispenser according to claim 7 wherein the active ingredient is a synthetic behavoir-modifying semiochemical mimic chemical.
12. A controlled release dispenser according to claim 1 wherein the active ingredient is a natural or synthetically prepared semiochemical.
13. A controlled release dispenser according to claim 3 wherein the active ingredient is a natural or synthetically prepared semiochemical.
14. A controlled release dispenser according to claim wherein the active ingredient is a natural or synthetically prepared semiochemical.
15. A controlled release dispenser according to claim 7 wherein the active ingredient is a natural or synthetically prepared semiochemical.
16. A semiochemical controlled release dispenser according to claim 3 wherein the semiochemical is selected from the group consisting of: E or Z-13-octadecenyl acetate, E or Z-11-hexadecenal, E or Z-9-hexadecenal, hexadecanal, E or Z-11 hexadecenyl acetate,E or Z-9-hexadecenyl acetate, E or Z-11-tetradecenal, E or Z-9-tetradecenal, tetradecanal, E or Z-11-tetradecenyl acetate, E or Z-9-tetradecenyl acetate, E or Z-7-tetradecenyl acetate, E or Z-5-tetradecenyl acetate, E or Z-4-tridecenyl acetate, E or Z-9-dodecenyl acetate, E or Z-8-dodecenyl acetate, E or Z-5-dodecenyl acetate, dodecenyl acetate, 11-dodecenyl acetate, dodecyl acetate, E or Z-7-decenyl acetate, E or Z-5-decenyl acetate, E or Z-3-decenyl acetate, Z or E,Z or E 3,13-octadecadienyl acetate, Z,Z or Z,E-7,11-hexadecadienyl acetate, Z,E-9,12-tetradecadienyl acetate, E,E-4,10-dodecadienyl acetate, E,E-8,10-dodecadienyl acetate, Z-6-henicosen-11-one, 7,8-epoxy-2-methyloctadecane, Z,Z,Z-1,3,6,9-nonadecatetraene, 5,11-dimethylheptadecane, 2,5-dimethylheptadecane, 6-ethyl-2,3-dihydro-2-methyl-4H-pyran-4-one, phenylacetaldehyde, nonanal, undecanal, methyl jasmonate, alpha-pinene, beta-pinene, terpinolene, limonene, 3-carene, p-cymene, myrcene, verbenene, camphene, camphor, longifolene, sabinene, beta-phellandrene, alpha-cubebene, allyl anisole, decanal, heptanal, E-2-hexenal, E-3-hexenal, hexanal, verbenone, 3-methyl-2-cyclohexenone, 3-methyl-3-cyclohexenone, frontalin, exo and endo-brevicomin, lineatin, multistriatin, chalcogran, 7-methyl-1,6-dioxaspiro[4.5]decane, pinocarvone, carvone, myrtenal, ipsenone, ipsdienone, 2-nonanone, 4,8-dimethyl-4(E),8(E)-decadienolide, 11-methyl-3(Z)-undecenolide, Z-3-dodecen-11-olide, Z,Z-3,6-dodecen-11-olide, Z-5-tetradecen-13-olide, Z,Z-5,8-tetradecen-13-olide, E-3-methyl-7-acetoxy-3-nonene, Z-14-methyl-8-hexadecenal, 4,8-dimethyldecanal, gamma-caprolactone, pentadecanal, octadecanal, hexadecanol acetate, octadecanol acetate, eicosanol acetate, 3,6,6-trimethylcyclohepta-2,4-dienone, chrysanthenone, hexyl acetate, E-2-hexenyl acetate, butyl-2-methylbutanoate, propylhexanoate, hexylpropanoate, butylhexanoate, hexylbutanoate, Z-9-tricosenel Z-5-tricosene, Z-14-nonacosene, Z-13-nonacosene, Z-13-heptacosene, Z-9-heptacosene, 1,7-dioxaspiro[5.5]undecane, 2,8-dimethyl-1,7-dioxaspiro[5.5]undecane, 2-ethyl-7-methyl-1,6-dioxaspiro[4.5]decane, tert-butyl-4 (or 5)-chloro-2-methyl-cyclohexanecarboxylate, methyl eugenol, alpha-ionone, 4-(p-hydroxyphenyl)-2-butanone acetate, E-beta-farnasene, nepetalactone, 3-methyl-6-isopropenyl-9-decenyl acetate, Z-3-methyl-6-isopropenyl-3,9-decadienyl acetate, E or Z-3,7-dimethyl-2,7-octadecadienyl propionate, 3-methylene-7-methyl-7-octenyl propionate, 2,6-dimethyl-1,5-heptadien-3 - o l a c e t a t e , Z - 2 , 2 - d i m e t h y l - 3 -isopropenylcyclobutanemethanol acetate, E-6-isopropyl-3,9-dimethyl-5,8-decadienyl acetate, Z-5-(1-decenyl)dihydro-2(3H)-furanone, 2-phenethylpropionate, 3,11-dimethyl-2-nonacosanone, 8-methylene-5-(1-methylethyl)spiro[11-oxabicyclo[8.1.0]undecene-2,2-oxiran]-3-one, 2-propylthietane, 3-propyl-1,2-dithiolane, 3,3-dimethyl-1,2-dithiolane, 2,2-dimethylthietane, E or Z-2,4,5-trimethylthiazoline, 2-sec-butyl-2-thiazoline and isopentenyl methyl sulfide.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US24202194A | 1994-05-05 | 1994-05-05 | |
| US08/242,021 | 1994-05-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2147078A1 true CA2147078A1 (en) | 1995-11-06 |
Family
ID=22913156
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2147078 Abandoned CA2147078A1 (en) | 1994-05-05 | 1995-04-13 | Composite polymer devices for controlled release of semiochemicals |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2147078A1 (en) |
-
1995
- 1995-04-13 CA CA 2147078 patent/CA2147078A1/en not_active Abandoned
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