CN1479572A - Barriers to prevent wood pests from entering wooden structures - Google Patents

Abstract

A multi-layer wood pest barrier that has a long lifespan that lasts as long as the building or structure it is protecting. Lifetime maintenance is achieved by binding at least one pesticide in a continuous or discontinuous layer of the polymeric matrix, thereby substantially reducing the release of the pesticide from the matrix. The rate of pesticide release from the substrate can be controlled by using a carrier such as carbon black. Release of the pesticide from the barrier can be further controlled by including a layer which renders the barrier substantially non-release.

Description

Barriers to prevent wood pests from entering wooden structures

Cross-references to relevant applications

This application claims the effective filing dates of US Provisional Application Serial No. 60/251,112, filed December 3, 2000, and US Provisional Application Serial No. 60/251,141, filed December 4, 2000.

This application also claims the effective filing date of U.S. Application Serial No. 09/353,494, filed July 13, 1999, which is a continuation of U.S. Application Serial No. 09/030,690, filed February 25, 1998 and published on November 16, 1999 as US Patent No. 5,985,304.

The entire disclosures of the aforementioned Provisional and Regular Applications are incorporated herein by reference.

technical field

The present invention relates to barriers for preventing the entry of pests, such as termites and borers, into areas and/or structures to be protected, such as dwellings, buildings and wooden structures, for long-term protection of these areas and/or structures. More specifically, the present invention relates to long-lived protective barriers and methods for preventing the entry of pests into areas and/or structures to be protected, especially areas containing wood items and structures containing wood. The invention also relates to methods of making protective barriers and methods of placing them around said areas and/or structures.

Background technique

Wood in contact with concrete, such as wood in wooden building structures, and wood in contact with soil such as fence posts, utility poles, railroad crossties, and wood supports are susceptible to one or more wood pests, including but not limited to Infestation of termites, ants and other borers can damage structures. Use insecticides to protect wood from these pests.

Commercial methods currently used to control pests such as wood-boring insects include spraying insecticides, fumigation with insecticides (e.g., by sealing the entire The insecticide is placed in the soil under the foundation and the soil is treated with a long-lived insecticide on the front and back of the building to repel and/or destroy pests such as termites. These existing business methods suffer from various drawbacks.

For example, one common method involves treating the soil under the foundation of a new building pre-treated with an insecticide to prevent termite infestation. Typically, pesticides are sprayed on and into the soil before buildings are constructed. Treated soils often lose their continuity during construction due to lack of communication between pesticide applicators and construction workers. Moreover, existing soil pesticides lose their biological activity after a period of time, to the extent that the treated soil is no longer effective against termite infestation.

The use of pesticides in spraying and fumigation can damage the environment and harm the health of humans and domestic animals. In addition, the mass release of the insecticide by spraying and in the spraying device provides a short-lived rapid release that prevents the entry of pests. Due to their rapid release, insecticides must be reapplied every few days to months or year to be effective.

When pesticides are placed in soil, large amounts of pesticides are usually released into the environment. Such releases are detrimental to the pesticide applicator, to persons at or visiting the site where the pesticide was used, and to the environment.

It is also not ideal to apply the insecticide in an amount sufficient to remain effective for a long period of time. Applying large quantities of pesticides can cause ecological and health problems, as well as unpleasant odors, soil leaching and evaporation of pesticides. Even if a large amount of insecticide is applied, it will dissipate in a relatively short period of time and will need to be reapplied. Another disadvantage of applying large quantities of insecticides is that concentrations start well above the minimum required to be effective but quickly drop below the minimum required to maintain a barrier in a relatively short time compared to the building quantity. Therefore, if no additional chemicals are applied under or around the building, the presence of termite colonies in the soil can invade the building.

A common method of applying additional pesticides is to inject pesticides around building foundations by injecting the pesticide into the soil beneath the concrete foundation, wetting the soil around the building, or a combination of both. This post-construction treatment is labor intensive and not suitable for continued conservation.

Accordingly, there is a need to provide and maintain long-lasting protection of areas and structures, such as wooden structures, using methods and devices that do not have the aforementioned drawbacks.

Contents of the invention

The present invention provides a multilayer wood pest barrier that has a long lifespan that lasts as long as the building or structure it is intended to protect. Lifetime maintenance is achieved by binding at least one pesticide in a continuous or discontinuous layer of the polymeric matrix, thereby achieving substantially reduced release of the pesticide from the matrix. The rate of pesticide release from the substrate can be controlled by the use of carriers such as carbon black or gas black. The release of the pesticide from the barrier can be further controlled by including additional layers which render the barrier substantially non-release.

Additionally, the barrier may comprise layers such as fabrics, screens, sheets, and combinations thereof. The additional layer may also contain one or more pesticides that are the same or different than the pesticides in the polymeric matrix layer of the multilayer barrier. These pesticides can be released from the additional layer for enhanced short-term protection.

The barrier and/or additional layer is made of a polymer selected from thermoplastic polymers, thermosetting polymers, elastomeric polymers and copolymers thereof. Adding pesticides to polymers that can be held or released at a rate that allows them to be effective long term as poisons or repellants for insects that damage wood structures while maintaining an effective concentration in the barrier to prevent insects from penetrating over the barrier.

According to one aspect of the present invention, there is provided a polymer-carrier system in which the pesticide is bound to the carrier as a bound friable mixture. The polymer matrix formed from this mixture is fabricated into thin polymer sheets or films. The sheet containing the bonded friable mixture is then placed adjacent to the wood structure to form an impenetrable barrier for wood pests. The additional layer can provide a means for a slow and relatively constant release of volatile pesticides to create an area of the barrier in the soil surrounding the wooden structure beyond the barrier itself. Polymers include thermoplastic polymers, thermoset polymers, elastomeric polymers and their copolymers, while insecticides include the family of insecticides known as pyrethrins.

According to another aspect of the invention, an exclusion zone is created by placing an extrusion close to the wooden structure to be protected. The expelling portion comprises a polymeric delivery system comprising a carrier capable of controlling release of the insecticide. The system can maintain a stable and effective insecticide concentration in the exclusion zone for a long time.

According to a further aspect of the present invention there is provided a pellet comprising a polymer and an insecticide to create and maintain an equilibrium concentration of the insecticide for ants, termites and other wood-boring insects in the exclusion zone of the wood structure . Treat the soil by placing the pellets close to the wood structure to protect the wood structure from termites, ants and other borers. Various methods can be used to place the pellets close to the wood structure. Additionally, the pellets can be embedded in the board or even contained in the foam. In preferred embodiments, the polymers include thermoplastic polymers, thermoset polymers, elastomeric polymers, and copolymers thereof, and the insecticide is a pyrethrin.

According to a further aspect of the invention, the exclusion zone is created by injecting a hot melt polymer mixture. The controlled release device comprises one or more pyrethrins and a polymer selected from thermoplastic polymers, elastomeric polymers and copolymers thereof.

In yet another aspect of the present invention, a temperature-driven controlled delivery device is used to provide the exclusion zone.

According to another aspect of the invention, a controlled release device is used to fumigate a structure. It is desirable to place a barrier or create an area to prevent any contact between wooden structures and insects that can damage these structures. The exclusion zone is needed to protect the wooden structure for a long time.

In yet another aspect of the invention, a high density polymer containing a low volatility insecticide that provides a low release rate of insecticide is combined with a low density (soft) polymer containing a higher volatility insecticide , thus providing a reliable exclusion zone.

According to another aspect of the present invention, the multi-layered barrier prevents insects such as crawling wood-boring insects and termites from passing through the protected area or structure for a long period of time, while avoiding damage to the installer of the barrier, people who visit or are in the protected area or structure, and Harmful effects on the environment. The barrier includes an inner active layer that contains and releases the pesticide (ie the pesticide releasing layer). The barrier also includes two pesticide retaining layers that allow only a small amount of pesticide to be released out of the barrier. Sandwiching the inner active layer between two pesticide-retaining layers allows substantially no pesticide to be released from the barrier. One or more additional layers may be included between the pesticide retaining layer and the pesticide releasing layer.

According to one aspect of the invention, the barrier comprises a plurality of polymer layers bonded together to form a thin flexible film. The film can be placed around areas where protection from reptiles such as termites and other pests is desired (eg, the foundation of a residence). According to a further aspect of the invention, the barrier is prefabricated elsewhere before the barrier membrane is placed in a desired location, such as in a borehole in a residential foundation.

According to a further aspect of the invention, the multilayer barrier is in the form of a sheet or film comprising at least one layer which provides the sheet or film with puncture strength properties. In yet another aspect of the invention, the multilayer barrier includes outer protective layers that protect the barrier from ultraviolet (UV) damage during installation and subsequently when exposed to sunlight.

According to yet another aspect of the invention, the pesticide is released from the active layer in a controlled manner to help form a substantially release-free barrier. In other words, providing controlled release from the active layer can help to release only a small amount of the pesticide from the barrier.

The present invention also provides an efficient method for fabricating multilayer barriers using conventional commercially available equipment. According to one aspect of the invention, lamp black or gas black is used in the premix for producing the active layer. Lamp black imparts the desired fluidity to the prepolymer, but unlike some other types of carbon black, lamp black does not adversely affect pesticide activity. Lamp black has been found not to reduce activity or break down pesticides.

According to another aspect of the invention, to make the prepolymer, all or at least most of the carbon black is mixed with the polymer particles prior to the addition of the pesticide. This method minimizes the adverse effect of carbon black on pesticide activity.

According to a further aspect of the invention, one or more adhesive layers are used to adhere the layers of the barrier to each other. One advantage of using an adhesive layer or layers is that the active layer can be made from a polymer that does not need to be bonded to the pesticide retaining layer or additional layers. This allows the use of low melting active layer polymers. The lower operating temperature reduces the loss of pesticides during the manufacture of the active layer.

Therefore, in view of the above, it is an object of the present invention to provide a barrier or zone of insecticides to protect wooden structures.

Another object of the present invention is to provide a barrier and exclusion zone comprising a long term low volatility barrier and a high volatility short term barrier to protect adjacent soil.

Yet another object of the present invention is to maintain the barrier for a longer period of time, ie about 10 to 20 years.

Yet another object of the present invention is to maintain the exclusion zone for a longer period of time, ie about 10 to 20 years.

The present invention, together with accompanying objects and advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings. Other aspects and advantages of the present invention will become apparent to those skilled in the art after a study of the specification and the appended claims.

Description of drawings

Figure 1 illustrates a first embodiment of the invention comprising a spunbonded polymer sheet and a physically melt bonded blend of polymer and biocide wherein the blend of polymer and biocide is bonded to the polymer in point form Chip.

Figure 2 illustrates a second embodiment of the invention comprising a spunbonded polymer sheet and a physically melt bonded blend of polymer and biocide wherein the blend of polymer and biocide is bonded to the polymer in strips Chip.

Figure 3 illustrates a first way of using the embodiment of the invention shown in Figures 1 and 2 and releasing the exclusion zone created by the insecticide.

Figure 4 illustrates a second way of using the first and second embodiments of the invention to create exclusion zones.

FIG. 5 illustrates a third way of creating exclusion zones using the embodiment of the invention shown in FIGS. 1 and 2. FIG.

Figure 6 illustrates a third embodiment of the invention in the form of a cylindrical expulsion.

Figure 7 illustrates a fourth embodiment of the invention in the form of a flat belt ejector.

FIG. 8 illustrates the manner in which exclusion zones are created using the embodiment of the invention shown in FIG. 6 .

Figure 9 illustrates the manner in which exclusion zones are created using the embodiment of the invention shown in Figure 7 .

Figure 10 illustrates another embodiment of the invention in the form of pellets inserted into the ground next to a wooden structure.

Figure 11 illustrates a cross-sectional view of a pellet placed on a surface.

Figure 12 illustrates the use of foam to apply pellets to a concrete structure.

Figure 13 illustrates a cross-sectional view of a concrete foundation after application of foam.

Figure 14 illustrates pellets placed on a plate.

Figure 15 illustrates a shot-containing board applied to a concrete foundation.

Figure 16 illustrates hot melt injection.

Figure 17 illustrates the spacing of hot melt injections.

Figure 18 illustrates plug fumigating cement blocks.

Figure 19 illustrates the application of the plug for fumigated cement blocks.

Figure 20 illustrates a layered device of the present invention.

Figure 21 is a cross-sectional side showing the layers of a multilayer barrier made according to another embodiment of the present invention.

Figure 22 is a perspective view of a prefabricated barrier made from a multilayer polymeric film of the present invention.

Figure 23 is a perspective view of a prefabricated barrier made from a multilayer polymeric film of the present invention.

Figure 24 is a cross-sectional side showing the layers of a multilayer barrier made according to another embodiment of the present invention.

Figure 25 illustrates the repellency against Termites chrysotermes.

Figure 26 illustrates repellency against house termites.

Detailed ways

It has been found that when barriers, alone or in combination with repellent zones of insecticides, are maintained in the soil surrounding these structures over time, insects which can damage such wooden structures are significantly reduced or eliminated. An exclusion zone is an area containing enough chemicals to deter fauna. In the present invention, the chemical agent is a pesticide and the fauna is insects, especially borers such as termites and ants. According to one embodiment of the invention, the insecticide is retained in the barrier and/or released from a controlled release device comprising a polymer matrix system, said device will last for at least 6 years, usually 10 years or even 30 years as long as.

It has been found that by sandwiching a pesticide-releasing layer between two substantially non-releasing layers, the infestation of pests can be prevented for an extended period of time. The substantially release-free layer controls the release of the pesticide such that only a small amount of the pesticide is released therefrom. These small amounts of pesticides are sufficient to repel at least most pests, and the barrier prevents the passage of the pests. Pesticides are very slow to deplete and as a result, the barriers of the present invention can be used to prevent pests from entering protected areas and/or structures for extended periods of time, up to 10 or even 30 years. Using the layers around the pesticide releasing layer to substantially prevent the release of the pesticide allows the inner pesticide releasing layer to release the pesticide at a higher pesticide release rate than the barrier. This allows the use of materials and processing conditions that cannot be used to produce a substantially release-free active layer (ie, a pesticide-releasing layer). Release from the pesticide release layer can also be controlled by infusing the pesticide into the polymer matrix and additionally using a carrier such as carbon black (including lamp black and gas black).

As used herein, the term "controlled release device" refers to a device capable of controlled and sustained release of a bioactive chemical onto its surface and from its surface into the surrounding medium (eg, soil). The term "biologically active" as used herein refers to stimulating an organism, usually in an inverse manner, until death including arresting effects. The term "pesticide" as used herein is meant to include any biologically active chemical substance that controls, repells, reduces and/or prevents the passage of pests through barriers. "Pest" as used herein is meant to include any harmful plant, animal or microorganism, such as arthropods, arachnids, stinkbugs, insects (such as ants, termites and other wood-boring insects), and fungi. Pesticides refer in particular to insecticides, herbicides, biocides (eg bactericides, viricides, fungicides and nematicides), and other biological control agents or treatment substances. Thus, the barriers of the present invention are used against all pests that cannot tolerate their lethal and/or repellent properties. The term "pesticide-effective amount", "insecticide-effective amount" or "fungicide-effective amount" refers to a dose of an active substance sufficient to exert the desired pesticidal, insecticide or fungicide activity.

According to another aspect of the invention, the device of the invention provides a method of preventing the release of biologically active chemicals into the surrounding environment. Controlled release devices release the insecticide at a higher rate first, followed by a lower, steady rate release. Also, the initial pesticide may be different from the prolonged release pesticide. This release gradient ensures that protected areas and/or structures such as wooden objects or structures containing wood are protected over a short period of time and that after the minimum effective dose is reached, only the amount of insecticide needed to replace degradation is released of pesticides. This release gradient reduces potential environmental and health concerns and reduces disposal costs. The release rate of the device is solely a function of device construction and device composition, independent of external factors such as water.

According to another aspect of the invention, the controlled release device releases the insecticide into the soil at a desired rate to create an area containing the "minimum effective amount" of insecticide required to prevent insect infestation. As used herein, the term "minimum effective amount" is defined as the amount of insecticide required in an area to prevent insects from entering the area, the particular amount being dependent on the particular insect and the particular insecticide. When placed close to a foundation or part of a structure below ground, a zone of exclusion is created in the soil close to the device. When placed between a non-wood structure part and a connected wood structure part, a zone of exclusion is created at the interface between the non-wood structure part and the connected wood structure part.

When used commercially, the pesticides used are generally those approved by national regulatory agencies such as the U.S. Environmental Protection Agency (EPA) or other equivalent regulatory agencies to kill or remove termites, ants, and other borers agent. Presently preferred insecticides for use in the present invention are pyrethrins, which include tefluthrin, cyhalothrin, cyfluthrin and deltamethrin. However, it will be apparent to those skilled in the art that other effective insecticides such as Isopropylphos, fenvalerate, cypermethrin, permethrin and natural pyrethrins may also be used. These insecticides are available from a number of commercial sources such as Dow Chemical Company, Mobay Company, Syngenta Crop Protection, Inc., Velsicol Company and FMC Company. Combinations of insecticides, or combinations of one or more insecticides with other biologically active ingredients, such as fungicides, may also be used in accordance with the present invention.

Referring now to the drawings, a first controlled release embodiment of the present invention shown in Figure 1 utilizes a polymer-carrier device for controlled release of an insecticide to form an exclusion zone. This embodiment comprises a spunbond polymer sheet 20, and a physically melt bonded mixture of polymer and biocide (illustrated as point 21 in Figures 1 and 3-5). The spunbond polymer sheet 20 can be a woven or nonwoven textile, or it can be a polymer sheet. Such textiles are available from many manufacturers such as Reemay, Exxon Fibers and Phillips Fibers. The textile is preferably woven or nonwoven polypropylene.

The polymers in the melt-bonding mixture may comprise any number of thermoplastic polymers, thermoset polymers, elastomeric polymers or copolymers thereof. The choice of polymer depends on the desired release rate, compatibility of the polymer with the insecticide, and environmental conditions. By way of example and not intending to limit the scope of the invention, the following polymers may be used: high density polyethylene, low density polyethylene, vinyl acetate, urethane polymers, polyesters, santoprene, polysiloxane or neoprene. However, the preferred polymers are high density and low density polyethylene. In certain embodiments, chlorpyrifos is the preferred pesticide, although other pesticides described herein may also be used.

The mixture of polymer and insecticide can be placed in dots on a spunbond polymer sheet. These points should be spaced so as to keep the amount of insecticide above the minimum effective amount sufficiently in the exclusion zone. A minimum effective amount is the minimum amount of insecticide required in an area to prevent insect infestation. The diameter of point 21 in Figures 1 and 3-5 is preferably about 0.5-1.5 cm and its height is preferably about 0.5-1.5 cm. The size and shape of the dots is a matter of user preference and can be made to suit the purchaser's job needs. The dots 21 may be arranged in rows, preferably with a spacing of about 1.5-4 cm between adjacent dots. Those skilled in the art will appreciate that other shapes of dots may be used depending on the particular application. Pesticide-releasing polymer sheets are placed adjacent to or around the wood structure to create a zone of exclusion through controlled release of the pesticide.

The second controlled release embodiment of the present invention also uses a polymer-carrier delivery system for controlled release of the insecticide comprising a spunbond polymer sheet 20 and a physically melt bonded mixture of the polymer and the insecticide . As with the first embodiment, the polymer sheet 20 may be woven or non-woven polypropylene to which the physically melt-bonded mixture (shown as strip 22 in Figure 2) is bonded. Similarly, the polymers and insecticides used in the first embodiment above can also be used in the embodiments described in this section.

The mixture of polymer and insecticide in the second embodiment can be placed on a spunbonded polymer sheet by using an extruder system capable of forming a strip (as shown in Figure 2). The height of the strips 22 may be about 1 centimeter, spaced about 5-15 centimeters apart. The strips should ideally be spaced about 10 cm apart. It is desirable to configure the strips in a configuration that maintains a steady state concentration of insecticide in the exclusion zone after an initial burst of insecticide release. After the strips are applied to the polymer sheet, the sheet is placed on or near the wooden structure to protect it from insects.

Binding fillers and/or carriers may also be included in all embodiments of the invention. The inclusion of bonded fillers and/or carriers releases a larger amount of pesticide for a given release rate, or releases a lower rate of release for a given amount of pesticide. The binding carrier binds the pesticide. Binding supports for binding pesticides include carbon-based supports such as carbon black (including lamp black and gas black), activated carbon, and combinations thereof. Alumina, aluminosilicates, hydroxyapatite, and combinations thereof are believed to be useful for binding bioactive chemicals similarly to carbon.

When using a carbon-based carrier, the first step is to ensure that the carbon is dry, after which a liquid insecticide is mixed with the carbon. Use only enough carbon black (filler) to create a brittle mixture. The term "friable" refers to flowable particles that are substantially dry or non-sticky. Certain pesticides must be heated to become a liquid. The liquid biocide binds or bonds to the very large surface of the finely dispersed carbon black, cooling the mixture so it can be incorporated into the polymer. Polymers that can be used in carbon applications are polyethylene (including low and high density polyethylene), polypropylene, copolymers or blends of polyethylene and polypropylene, polybutene, epoxy polymers, polyamides , acrylate-styrene-acrylonitrile copolymer, aromatic or unsaturated polyester, polyurethane, polysiloxane or any other suitable polymer or copolymer thereof.

The carbon-insecticide mixture of the first and second embodiments (or only the insecticide if no carbon is used) is then mixed with a polymer, preferably polyurethane, in molten, powder or liquid state. This mixture is then bonded to a polymer sheet. In the first and second embodiments of the invention, the polymer and insecticide are melt bonded to the polymer sheet.

Another way to bond a mixture of polymer and pesticide to a polymer sheet is through "through-injection molding." In "through injection molding," molten material is injected from a hot nozzle through a perforated mesh into a mold. The molten material flows under pressure through the mesh and solidifies in the mold. The porous mesh allows air to escape while the molten material is being injected, but it also holds the molten material under pressure until it cools.

A different method of bonding the mixture of polymer and insecticide to the polymer sheet is to place the molten mixture of polymer and insecticide on the spunbonded polymer sheet. If the mixture is molten, it must be allowed to cool, solidify and solidify. "Molten mixture of polymer and insecticide" as used hereinafter means that the polymer is molten or already in a liquid state. Depending on its melting point, the insecticide may also be molten or contained in a slurry solution. The "molten mixture of polymer and pesticide" may also contain carbon or other additives that do not melt but flow with the molten mass of polymer/pesticide.

The first and second embodiments of the present invention should provide a rate of release sufficient to maintain an effective concentration of insecticide in the exclusion zone to kill or repel insects, but slow enough to maintain an effective concentration.

In general, preferred compositions in the first and second embodiments of the present invention comprise about 70-95 parts by weight of carrier polymer, about 0-15 parts by weight of carbon, and about 5-30 parts by weight of pesticides. Design considerations for controlled release devices vary depending on factors such as user preference and geographic conditions. In both embodiments the polymer delivery system maintains a steady state release rate for at least 6 years after the initial burst release of the insecticide to act as a barrier to insects such as ants and termites. However, the equilibrium concentration in this embodiment can be easily adjusted to suit each user's specific requirements.

The embodiments shown in Figures 1-5 may optionally comprise a biocide impermeable sheet (not shown) such as a metallised foil. A metallised foil or polymer extruded sheet is laminated to one side of a spunbond polymer sheet to induce flow of insecticide.

Yet another embodiment of the present invention is a barrier of pest impermeable sheets wherein a cohesive friable mixture of bioactive chemicals or pesticides and a carbon carrier is placed in a polymer that does not substantially release biologically active chemical substances. The phrases "substantially no release" and "only a small amount" are defined as release rates of less than 0.4 µg/cm ² /day, preferably less than 0.1 µg/cm ² /day, most preferably less than 0.05 µg/cm ² /day. This embodiment includes release rates below the detectable limit. In this embodiment, pests are prevented by "sucking" or "scratching" the polymer surface and detecting the presence of bioactive chemicals harmful to the pests. The lifetime of this barrier is much longer than that of a barrier with a higher release rate. Also, cracking or tearing of the polymer is less prone to "leakage" of bioactive chemicals. Therefore, two or more layers in this embodiment are suitable to maintain an intact barrier. Multiple layers will create a tear or hole in one layer, but pests will not get through the second or subsequent untorn layers. A protective layer, such as a fabric, may further be placed on one or both surfaces of the barrier to avoid tearing.

Once fabricated, the polymer-carrier delivery systems of the first and second embodiments are placed adjacent to structures that are desired to be protected from insect infestation. Figures 3-5 are illustrations of various application modes for the dotted or striped sheet embodiments of the present invention. The configuration of Figure 1 is shown in Figures 3-5, but it should be understood that the configuration of Figure 2 or other configurations could well be used.

In Figure 3, the polymer-carrier delivery system 1 is placed under and next to a concrete foundation 23 of a wooden structure 100 creating an exclusion zone 10 to protect the structure from termites, ants and other borers.

In FIG. 4 , the polymer-carrier delivery system 2 is placed under a structural element 24 such as a porch, patio, walkway or under a sub-foundation next to a wooden structure 101 to form an exclusion zone 10 .

In Figure 5, the polymer-carrier delivery system 3 is placed above and to the side of the concrete foundation 23 of the wooden structure 102, but below the wooden part 25 of the structure, to create a zone of exclusion.

Another embodiment of the present invention is shown in FIGS. 6 and 7 . This embodiment involves an ejection portion such as an extruded flexible cylinder 26 and an extruded flexible flat belt 27 shown in Figures 6 and 7 respectively. Various polymers can be used, which can be roughly divided into four categories. The various classes include thermoplastic polymers, thermoset polymers, elastomeric polymers and copolymers of the above three groups. As examples, certain polymers selected from four classes that may be used are: high density polyethylene, low density polyethylene, ethylene vinyl acetate (EVA), vinyl acetate, polyurethane, polyester, santoprene, silicone alkanes, neoprene and polyisoprene. In certain embodiments, the preferred insecticide is chlorpyrifos, although other insecticides as described above may also be used. Fillers can also be added.

Preferably, the diameter of the cylinder is about 5-15 mm, but preferably about 10 mm for optimum steady state release of the pesticide into the exclusion zone. The flat belt preferably has a thickness of about 1-6 mm and a width of about 5-15 mm. It should be noted, however, that the cylinder and flat belt can be designed to meet the various conditions encountered by the user.

In general, in order to maintain the equilibrium concentration of insecticide in the exclusion zone for a long time, the composition in this embodiment of the invention should contain about 70-95 parts by weight polymer, about 0-30 parts by weight carbon and about 5-30 parts by weight of pesticides. However, the composition of the ejection portion can be varied to meet the specific requirements of the user. It is estimated that the exclusion zone can be maintained for at least 6 years for the cylinder as well as for the flat belt.

The ejector can be placed in different positions to form the exclusion zone. FIG. 8 illustrates the manner in which the ejection section shown in FIG. 6 is used. One or more flexible cylinders 26 are placed between the concrete foundation 23' and the wooden part 25' of the building. The flexible cylinder 26 releases the insecticide at a controlled rate to create a zone of exclusion. An advantage of this configuration is that the flexible cylinder 26 can be placed under an already constructed building. Similarly, flexible cylinders may be placed in the ground vertically, not shown, as opposed to horizontally. Those skilled in the art will appreciate that the ejection portion can have other suitable shapes and be placed in any suitable position depending on the factors considered in the specific application.

FIG. 9 illustrates a method of using the flexible flat belt ejector shown in FIG. 7 . By placing one or more flexible flat straps 27 between or next to the concrete foundation 23" and the wooden part 25" of the building, the exclusion zone can be created. In an embodiment not shown in the figures, the flexible flat belt 27 can also be placed vertically beside the wall. Again, any suitable placement of the flat straps is contemplated to be within the scope of the present invention.

Controlled release of insecticides can also generally be achieved by using pellets of the embodiments shown in Figures 10-13. Pellets 13 comprise polymer, biocide and preferably also fillers. Various polymers can be used in this embodiment. They can include the four classes of polymers consisting of thermoplastic polymers, thermoset polymers, elastomeric polymers and copolymers thereof. The choice of polymers from these four categories depends on the design concept, and the preferred polymers are high-density polyethylene or low-density polyethylene. Additionally, the insecticide preferably includes tefluthrin, but the following insecticides may also be used: Isopropylphos, fenvalerate, cypermethrin, permethrin and other pyrethrins. For best results, a support such as carbon may also be added to the mixture.

The pellets 31 release the insecticide at a controlled rate over an extended period of time to create a zone of exclusion. The composition of the pellets required to maintain the exclusion zone in the soil is about 70-95 parts by weight polymer, about 0-30 parts by weight carbon black and about 5-30 parts by weight insecticide. The composition of the pellets is ultimately a matter of user preference.

The pellets may be of any suitable size depending on the desired application, for example 1-25 mm in diameter (or width and thickness if rectangular) and 2-20 cm or more in length. Furthermore, the size of the pellets and the concentration of the insecticide can be easily adjusted to suit the needs of a particular user. However, the exclusion zone can be maintained for at least 6 years.

In addition, the pellets 31 also have the advantage that they can be conveniently placed anywhere. A pellet of this embodiment of the invention is shown in FIG. 10 . The pellets 31 are inserted close to the wooden structure 25 . The pellets shown in Figure 10 can be placed under a concrete foundation 23'', or they can be placed directly under a wooden structure (not shown) to create an area 10 around the wooden structure 25'' to repel structure of insects. FIG. 11 illustrates a cross-sectional view of a pellet 31 embedded on a surface 40 .

The pellets are readily applicable in a wide variety of applications. FIG. 12 illustrates spraying 50 of shot onto a concrete structure surface 40 . Figure 15 illustrates placing shot 33 on a prefabricated panel 300 to treat the surface.

As shown in FIG. 13, foam 41 is used to apply pellets 32 to a surface 40, such as soil or concrete. The pellets are first added to the foam in a manner known in the art. The fine pellet-containing foam 41 is then sprayed 50 onto the surface 41 with an electric sprayer 70 as shown in FIG. 12 to form a protective layer for the surface. The pellets 32 then release the insecticide, creating a protective barrier in the soil to protect the wood from pests. For best results, foam 50 is composed of polyurethane. Silicones, polyesters or polyvinyl acetates may also be used. The size of the pellets 32 can vary depending on the thickness of the foam and the desired concentration of insecticide in the exclusion zone. The thickness of the foam applied to the surface can vary according to user preference. The exclusion zone can be maintained for at least 6 years. In addition to being used as a carrier for insecticides, the foam can also be used with treated cement and as an insulator.

As shown in Figure 14, prefabricated panels with embedded pellets 33 can also be used as an embodiment of the present invention. Such a plate 300 may be made of any type of material suitable for securing the pellets 33 . The board is preferably composed of expanded polystyrene which is a registered trademark of the Dow Chemical Company. The plate can be applied in any of a variety of ways and it can also operate as an insulating means. One mode of application is shown in FIG. 15 , where a panel 300 containing shot 33 is placed on a concrete surface 42 . The embedded pellets are regularly spaced at intervals determined by the desired amount of insecticide.

In another embodiment as shown in Figures 16 and 17, the controlled release device comprising the polymer matrix and the insecticide may be applied by thermal melting. This embodiment is designed to meet the needs of the structure already in place. As noted above, the polymer matrix may comprise any of the four classes of polymers described above. Similarly, any of the above-mentioned insecticides may be used. However, high density or low density polyethylene is preferably used or contains pyrethrins. While meeting the needs of the user, for best results the concentrations of the various substances in the hot melt application should be about 70-95 for the polymer, about 5-30 for the biocide, and about 0-30 for the filler/carrier. 30.

FIG. 16 shows injection of hot melt 50 into the ground adjacent to concrete foundation 43 with injector 400 . The concrete structure 43 supports the wooden structure 250 . Figure 17 illustrates the spacing between hot melts 50 that have been injected into the ground.

In another embodiment, FIGS. 18 and 19 illustrate fumigation of a structure 500 using an insecticide. By injecting or placing the controlled release device in or near a structure that can be fumigated, the insecticide released from the controlled release device can be vaporized, thereby fumigation of the structure. FIG. 18 illustrates the use of plug 34 to fumigate a structure 500 made from building blocks 502 . Similarly, FIG. 19 illustrates a method of applying a controlled release device by drilling a hole 700 in a cement board 900 with a drilling machine 800 . Once inserted, the plug can fumigate the structure.

Figure 20 shows another embodiment of the device of the present invention. A first polymer 200 comprising a medium or high density polymer of a low vapor pressure insecticide is combined with a second polymer 202 of low density comprising a higher volatility, ie higher vapor pressure, insecticide. Referring to the degree of crosslinking in a polymer, high, medium and low density are terms well known in the art of polymer technology. High vapor pressure is defined as a vapor pressure in excess of about 1 mPa, preferably about 10-100 mPa. Low vapor pressure is defined as less than 1 milliPascal, preferably about 0.05-0.5 milliPascal. The thickness of the first polymer 200 is preferably about 1/32-1/8 inch. The low vapor pressure insecticide is preferably permethrin or cyhalothrin. Suitable materials for the first polymer 200 are selected from polyurethane, high density polyethylene and polypropylene. The second polymer 202 is placed adjacent to the first polymer 200, preferably attached to the first polymer 200. The first polymer 200 is preferably water and radon gas impermeable. Accordingly, the first polymer 200 is preferably a sheet, which may be film or spunbond. According to the present invention, the first polymer 200 can be two subdivisions, one subdivision 204 is a permeable medium or high density polymer containing a low vapor pressure insecticide, and the other subdivision 206 is a non-insecticide. agent impermeable layer. An impermeable layer has the advantage of preventing or reducing the handling of the installer's encounter/contact with bioactive chemicals. The impermeable layer may be, for example, Mylar, Vinyl or Saranax.

The second polymer 202 is a low density polymer, preferably polyethylene-vinyl acetate copolymer, low density polyethylene or blends thereof. The higher volatility or higher vapor pressure insecticide placed in the second polymer is preferably a synthetic pyrethroid such as tefluthrin.

The second polymer 202 may be in the form of the aforementioned pellets, with the first and second polymers positioned such that the first polymer is beneath the foundation slab and the second polymer is dispersed in the soil proximate the foundation. More preferably, the second polymer 202 is in the form of a woven or nonwoven open mesh as shown. The mesh holes may be open to the touch to a size of about 1-4 inch squares, with ribs 208 having a cross-section with a width of about 1 mil to 1/8 inch. Fiber fabrics made of polyethylene, polypropylene or polyester can be used as mesh. For the sheet of first polymer 200 and the open cell grid of second polymer 202, the device formed from the combination of the first and second polymers 200, 202 is preferably placed below ground. The first polymer sheet 200 is placed adjacent to the second polymer 202 open grid, the first polymer 200 sheet is in contact with the foundation 43 or close to the foundation 43 and is located between the foundation and the second polymer 202 open grid . The mesh material can absorb and act as a reservoir for bioactive chemicals.

During operation, the first polymer 200 continues to act as a physical/chemical barrier against insect intrusion. However, due to the slow release of the first polymer 200, very little insecticide is released to create the exclusion zone for about the first year after installation. In addition, it is also impossible to provide a defect-free barrier due to penetrations such as wires and pipes and punctures or tears during construction. Therefore, the second polymer 202 is arranged so as to create a repellent zone within a few days after placement, thereby preventing the entry of insects through the imperfections of the first polymer 200 . Thus, the first polymer 200 has the following three functions: insect barrier, vapor/moisture barrier and radon gas barrier. The first polymer 200 is designed to last at least 10 years, preferably up to and exceeding 20 years. The second polymer 202 is designed to last at least 5 years, preferably up to about 10 years. When the second polymer 202 is exhausted and is no longer effective against insects, the first polymer 200 reaches a concentration of released insecticide sufficient to maintain the exclusion zone. Preferred multi-layer barrier

Another embodiment of the present invention is a multilayer barrier comprising at least three layers: a pesticide releasing layer and two pesticide retaining layers. The pesticide holding layer is located on both sides of the pesticide releasing layer. The pesticide-retaining layer (ie, the "active" layer or layer containing the pesticide active ingredient) contains at least one pesticide. The pesticide-releasing layer releases at least one pesticide. The pesticide retaining layer allows only a small amount of pesticide to be released out of the barrier. The inner active layer is sandwiched between two pesticide retaining layers such that essentially no pesticide is released from the barrier. The thickness of the barrier is generally from about 0.010 inches (10 mils) to about 0.030 inches (30 mils), preferably from about 0.014 inches (14 mils) to about 0.016 inches (16 mils). The multi-layer barrier can be formed as a sheet or film and placed in areas requiring protection from crawling insects such as termites and other pests, such as the surrounding areas of residential foundations.

The multi-layer barrier protects the area and/or structure by preventing pests, such as crawling borers and termites, from entering the protected area and/or structure, and by repelling and/or preventing pests from passing through the barrier. The multi-layer barrier protects the area and/or structure for an extended period of time while avoiding deleterious effects on the installer of the barrier, persons accessing or within the protected area and/or structure, and the environment. The release of pesticides from the barrier is minimal so that the barrier can be handled by the installer without adverse consequences. The minimal release of pesticides results in minimal impact on the environment and allows the barrier to last for a long time, often 10 or even 30 years. The multi-layer barrier can be installed under the foundation of a building prior to construction to provide the owner of a new building title with long-term protection from pests such as crawling borers and termites. In addition to keeping pests out of the protected area and/or structure, the multi-layer barrier helps prevent moisture and harmful gases, such as radon, from penetrating the protected area and/or structure.

The barrier of this embodiment of the invention may comprise one or more additional layers. Additional layers may be placed at any desired location relative to the pesticide-releasing layer and the pesticide-retaining layer, but preferably one additional layer is positioned between the pesticide-releasing layer and the pesticide-retaining layer.

The barrier of this embodiment of the invention may comprise additional layers which improve the breakdown strength properties of the barrier. The additional layer can be placed at any desired location relative to the desired layers, but preferably an additional layer is placed between the pesticide releasing layer and the pesticide retaining layer. A multilayer barrier may be in the form of a thin sheet or film comprising at least one layer that provides the sheet or film with puncture strength. The thickness of the puncture strength layer is generally about 0.002 inches (2 mils) to about 0.006 inches (6 mils), preferably about 0.004 inches (4 mils).

The barrier of this embodiment of the invention may also include one or more additional protective layers to protect the barrier from environmental elements such as ultraviolet light. An additional layer of protection protects the screen from UV rays when it is installed and later when it is exposed to sunlight. Additional protective layers may be placed anywhere in relation to the other layers, but are typically located outside of the other layers of the barrier. The protective layer can be made of a heat sealable polymer to simplify heat sealing the barrier. The protective layer generally has a thickness of about 0.0005 inch (0.5 mil) to about 0.003 inch (3 mil), preferably about 0.001 inch (1 mil). The protective layer is generally about 15-30% by weight of the barrier, preferably about 22%. The areal density of the protective layer is usually about 13-78 grams material/square meter, preferably about 26 grams material/square meter.

The layers of the barrier are held together or bonded to each other to form a single multi-layer product. The layers are bonded to each other either directly or through the use of an adhesive layer. For example, a tie layer can be used to bond the puncture strength layer to the active layer (ie, the pesticide releasing layer) and the pesticide retaining layer. Similarly, a tie layer can be used to bond the puncture strength layer to the pesticide releasing layer. One advantage of using one or more tie layers to secure the layers of the barrier to each other is that the active layer can be made from a polymer that does not need to be able to bond to the pesticide retaining layer or additional layers. This allows the use of polymers in the active layer (ie the pesticide releasing layer) which has a low melting point. The lower processing temperature reduces the loss of pesticides during the manufacture of the active layer.

The pesticide-retaining layer is preferably made of a polymeric material that allows only a small amount of pesticide to pass through such that substantially no pesticide is released from the barrier. A preferred polymer is Saranex ^(R) available from Dow Chemical Company, Midland, Michigan. The pesticide-retaining layers of each layer generally have a thickness of about 0.001 inch (1 mil) to about 0.005 inch (5 mil), preferably about 0.002 inch (2 mil). The pesticide retention layer is generally about 20-40%, preferably about 25-35%, more preferably about 30% by weight of the barrier. The area density of the pesticide retaining layer is usually about 26-130 grams material/square meter, preferably about 60 grams material/square meter. In this embodiment of the invention, the pesticide retaining layer controls the release of the pesticide from the barrier, rather than the pesticide releasing layer. However, by controlling the release of pesticide from the pesticide releasing layer, the pesticide releasing layer helps to ensure that only a small amount of pesticide is released. In some cases, the release rate of the pesticide from the barrier can be below the lower limit of detection.

The pesticide releasing layer can be made of a polymer matrix and the pesticide dispersed in the polymer matrix. The polymer matrix can be a controlled release polymer matrix that can form a film. In one embodiment of the invention, the polymer matrix is made of low density polyethylene. Currently, linear low density polyethylene is preferred as the polymer matrix material because of its lower melting point than other polyethylenes. The low density polyethylene may be a metallocene catalyzed low density polyethylene. Other polymers suitable for polymer matrix materials include, but are not limited to, urethane, polyurethane, epoxy, polysiloxane, polyethylene+wax (PE+wax), aromatic polyester, pellethane, polyethylene-vinyl acetate Copolymers (EVA), polyethylene, HDPE, LDPE, vinyl acetate, polyester, santoprene, neoprene, polyisoprene, polypropylene, copolymers of polyethylene and polypropylene or Blends, polybutenes, epoxy polymers, polyamides, acrylate-styrene-acrylonitrile, unsaturated polyesters, polysiloxanes, and combinations thereof. The polymer used for the polymer matrix may be hydrophobic.

Examples of pesticides suitable for use in the pesticide release layer include, but are not limited to, pyrethroids, neonicotinoids, isofenphos, fenvalerate, pyrethrins, and combinations of such compounds. Preferred pesticides for use in the pesticide release layer include: Tefluthrin, Permethrin, Cyhalothrin, Pyrethrin, Deltamethrin, Cypermethrin, Phenothrin, Cyfluthrin, Deltamethrin , chlorpyrifos, fenoxycarb, diazinon, dichlorophen, methyl isothiocyanate, pentachlorophen, perbromethrin, chlorfenapyr, fipronil, neonicotinoids, and combinations of these compounds. Examples of suitable neonicotinoids include, but are not limited to, thiamethoxam, nitenpyram, imidacloprid, clothianidin, acetamiprid, and thiacloprid. A preferred pesticide for use in the pesticide releasing layer is cyhalothrin. Cyhalothrin is a high potential termiticide with a lethal concentration - 0.0001 μg/termite - which kills 99% of the termites tested (LC ₉₉ ), for the most important American termite species - Reticulitermes flavipes). In certain embodiments, at least one pesticide in the pesticide-releasing layer is present in an amount of at least 5% by weight of the pesticide-releasing layer. In other embodiments, at least one pesticide in the pesticide releasing layer is present in an amount of at least 10% by weight of the pesticide releasing layer.

Multi-layer barriers provide some form of termite resistance. Multilayer barriers provide lethal pesticide protection by using a pesticide such as cyhalothrin in the barrier to deliver a lethal dose of the pesticide that can then be delivered to termites that then come into momentary contact with the barrier. The multi-layer barrier also provides repellent protection against termites. Multi-layer barriers also provide physical protection against termites, as the barrier preferably has both smooth and rough outer pesticide retaining layers so that termites cannot start eating the barrier.

The pesticide-releasing layer made of a polymer matrix and the pesticide dispersed in the matrix may also include a carrier such as carbon black (including lamp black and gas black). It has been found that carbon black in the form of lamp black offers the advantages of not deactivating or decomposing the pesticide, being easy to extrude and being easy to prevent aggregation. The use of carbon black in the form of lamp black aids in the production of friable mixtures of flowable particles that are substantially dry or non-sticky and aids in the evaporation of pesticides during extrusion. The pesticide releasing layer generally has a thickness of about 0.001 inch (1 mil) to about 0.020 inch (20 mil), preferably about 0.001 inch (1 mil) to about 0.005 inch (5 mil), most preferably about 0.002 inches (2 mils) or 0.0037 inches (3.7 mils). The pesticide releasing layer is generally about 15-30%, more preferably about 22-25%, most preferably about 24%, by weight of the barrier. The area density of the pesticide releasing layer is usually about 22-115 grams material/square meter, preferably about 45 grams material/square meter.

The pesticide releasing layer should release the pesticide in a controlled manner. This controlled release helps the pesticide retaining layer release only a small amount of pesticide from the barrier to assist in forming a substantially release-free barrier. In other words, only a small amount of pesticide release from the barrier can be helped by controlling the release from the active layer (i.e., the pesticide-releasing layer).

In addition to pesticides that repel and prevent insect penetration, it is desirable to include one or more fungicides in the barrier. The fungicide may be contained in the pesticide-releasing layer containing the pesticide or in a separate fungicide-releasing layer. A separate fungicide-releasing layer may be located within the pesticide-retaining layer. One or more fungicides may be included to prevent destruction of the intact barrier by fungi.

The term "fungicide" as used herein covers compounds active against phytopathogens, which can belong to a very broad class of compounds. Examples of suitable classes of fungicidally active compounds include room temperature (25°C) solid and room temperature liquid fungicides including, but not limited to, triazole derivatives, strobilurins, carbamates (including thio and dithioamino formate), benzimidazoles (such as thiabendazole), N-trihalomethylthio compounds (such as captan), substituted benzenes, carboxylic acid amides, benzamides, phenylpyrroles, and their compounds. Suitable fungicides also include: chloropicrin, a mixture of methyl isothiocyanate and 1,3-dichloropropane, N-methyl sodium dithiocarbonate, 2,3,5,6-tetrachloro - 1,9-Benzoquinone, calcium cyanamide, biphenyl, copper naphthenate, dichlorophen, toxin, and combinations of these compounds.

The bactericidally active compound is used in the active layer of the multilayer barrier in a bactericidally effective amount. Mixtures of one or more of the aforementioned fungicidally active compounds may also be used as active ingredients in the practice of the present invention.

When the barrier of this embodiment of the invention comprises one or more puncture strength layers, the puncture strength layers are preferably made of fibrous fabric. The puncture strength layer helps prevent cracks and punctures and helps provide a barrier to tensile strength. Preferred fiber fabrics are made from woven polymers. Particularly preferred are woven polymers made from high density polyethylene. The thickness of the fibrous web is generally from about 0.002 inches (2 mils) to about 0.006 inches (6 mils), preferably about 0.004 inches (4 mils). The fibrous web layer is usually about 11-24%, preferably about 17-18%, of the weight of the barrier. The areal density of the fibrous web layer is generally about 30-95 grams material/square meter, preferably about 62 grams material/square meter.

In order to reduce the release of pesticides from the pesticide-releasing layer at the edge of the barrier, the pesticide-releasing layer can be made wider and longer than the corresponding pesticide-releasing layer, and the pesticide-retaining layer can better adhere to each other directly or through the adhesive layer. Knot.

Placing one or more additional layers (ie, layers other than the pesticide releasing layer) within the pesticide retaining layer may provide an advantage if the barrier is to be penetrated by pests. As the pesticide is released, the additional layer is impregnated with the pesticide. Thus, the additional layer provides additional physical and pesticidal protection from pests passing through the barrier.

One advantage of the multi-layer barrier of this embodiment of the invention is that the barrier prevents termites, wood-boring pests, and other pests from entering the whole or part of the wood structure. Another advantage of the barrier is that it can prevent the passage of pests for a long time, which can be as long as 10 years, or even 30 years. Yet another advantage is that when the barrier is installed, its outer surface is substantially free of pesticides. This increases the safety of the handler and installer of the barrier. A further advantage of this embodiment of the invention is that the method of manufacturing the barrier is efficient and the barrier can be produced in large quantities using conventional commercially available equipment. In addition to preventing pests from entering the protected area and/or structure, the barrier of this embodiment of the invention also prevents moisture and noxious gases from penetrating into the protected area and/or structure.

According to one aspect of the invention, the barrier comprises a plurality of polymer layers bonded together to form a thin flexible membrane. The film can be placed in areas that require protection from reptiles such as termites and other pests, such as around residential foundations.

Presently, the preferred multilayer barriers of the present invention consist of thin eight-layer polymer films. The layers are bonded together to form a flexible film. Presently preferred barrier films have a thickness of from about 0.015 inches (15 mils) to about 0016 inches (16 mils). A currently preferred barrier has a width of about 81-83 inches. A presently preferred barrier has a weight of about 327 g/m ² . The eight layers of the presently preferred membrane are shown in cross-section in FIG. 21 .

Referring now to FIG. 21 , barrier film 110 includes outer layers 112 and 114 . The outer layers 112 and 114 are made of extrusion coating grade polyolefin plastomer (trade name and model: Affinity® ^PT1450 , available from Dow Chemical Company), color concentrate (a mixture produced by Colortech Ltd. of Brampton, Ontario, Canada, Made from a blend of carbon black Vulcan ⁽ R) 9 from Cabot Corporation and LDPE), and extrusion coating grade polyethylene (Novapol ⁽ R) LC-0522-A, available from Nova Chemicals Canada Inc.). The material used to make the outer layers 112, 114 is also referred to below as "Neogenerated Resin" or "NGR". The materials used to make the outer layers 112, 114 help provide UV protection and heat sealing to the barrier. The outer layers 112, 114 have a melting point of about 110°C. The life expectancy of the outer layers 112, 114 is expected to be equal to that of moisture barriers currently used in construction, and the material is expected to last for an indeterminate amount of time when applied in the subsurface. In a preferred embodiment, the outer layers 112, 114 have a thickness of about 0.0011 inches (1.1 mils) and have a thickness of about 26 grams material per square meter.

Inside the outer layers 112,114 are pesticide retaining layers 116,118. The pesticide retaining layers 116, 118 are made of Saranex ^(R) 14, a product of the Dow Chemical Company. Saranex® ¹⁴ has a melting point above 143°C and is believed to be non-biodegradable or photodegradable. ^Saranex® 14 is a five-layer coextruded product consisting of low density polyethylene, vinylidene chloride/vinyl chloride copolymer (ie Saran), ethylene/vinyl acetate copolymer, and silica. In a preferred embodiment, the layer made of Saranex ^(R) 14 has a thickness of about 0.002 inches (2 mils) and an areal density of about 53 grams material/square meter.

Inside the pesticide holding layer 116, there is an adhesive layer 120 for bonding the pesticide holding layer 116 and the fiber fabric layer 122 together. The adhesive layer 120 is made of the same material as the pesticide holding layer. In a preferred embodiment, the adhesive layer 120 has a thickness of about 0.0011 inches (1.1 mils) and an area density of about 26 grams LDPE/square meter.

The fabric layer 122 is made of high density polyethylene, specifically Sclair ^(R) HDPE No. 99G available from Nova Chemicals. The fibrous fabric layer is preferably woven HDPE. The HDPE used to make the fiber fabric layer 122 is extruded into sheets and cut into tapes. The tape is then pre-stressed and spun into a sheet, which is encased in the barrier film 110 to provide tensile puncture strength properties. The HDPE used to make the fabric layer 12 is very similar to the resins used to make common water pipes and is expected to have a similar lifetime. In a preferred embodiment, the fibrous fabric layer 122 has a thickness of about 0.004 inches (4 mils) and an areal density of about 63 grams material per square meter.

The bonding layer 126 bonds the fabric layer 122 and the active layer 128 together. Tie layer 126 is extrusion coating grade polyethylene available from Nova Chemicals Canada, Inc., such as Novapol ⁽ R) LC-0522-A. The melting point of the adhesive layer 126 is about 165°C. In a preferred embodiment, the adhesive layer 126 has a thickness of about 0.001 inch (1 mil) and an area density of about 25 grams material/square meter.

Located between the adhesive layer 126 and the pesticide retaining layer 118 is an active layer 128 . In some embodiments of the present invention, the active layer 128 is composed of about 0.82-1% by weight of cyhalothrin industrial solution (85% by weight), about 0.85-1.05% by weight of carbon black, commercially available from General Carbon Co., Ltd. Lamp Black #6 (also known as Lamp Black Extra Fine #6), and about 20.9-23.1% by weight of low density polyethylene (LDPE) resin. In another embodiment, the active layer 128 is composed of 11.74 wt% cyhalothrin, 10.87 wt% lamp black #6, and 77.39 wt% low density polyethylene (LDPE) in an 85.2 wt% industrial solution Made of resin. Preferably, the LDPE resin is PEXU59400.00 (also known as PEXU59400), a metallocene catalyzed extrusion coating grade LDPE available from Dow Chemical Company. The choice of specific LDPE is based on its low melting point of about 80°C and its extrusion coating properties. In a preferred embodiment, the active layer 128 has a weight of about 23% of the barrier film 110, a thickness of about 0.002 inches (2 mils), and an areal density of about 45 grams material/square meter.

In the eight-layer barrier film described above, the outer layers 112 and 114 together with the tie layer 120 constitute approximately 22.2% by weight of the barrier film 110 . Together the pesticide retaining layers 116.118 comprise approximately 29.7% of the barrier film 110 by weight. The fabric layer accounts for approximately 17.8% by weight of the barrier film 110 . The tie layer 126 constitutes approximately 6.4% by weight of the barrier film 110 . The active layer 128 constitutes approximately 23.9% by weight of the barrier film 110 .

The release rate of the bioactive chemical from the adhesive layer 126 to the other layers is higher than the release rate of the bioactive chemical from the barrier film 110 to the outside of the barrier film 110 . The release rate of cyhalothrin in the preferred eight-layer embodiment was measured to be less than 0.002 μg/cm ² /day. The barrier film 110 is used to prevent wood damaging organisms from entering the structure while minimizing the concentration of cyhalothrin in the soil and other surrounding environments.

Another suitable multilayer barrier may consist of a thin six-layer polymer film, where the layers are bonded to each other to form a flexible film. In one embodiment, the six-layer polymeric film has a thickness of about 0.012 inches (12 mils), a width of about 81-83 inches, and a weight of about 263 g/ ^m2 . A cross-section of the layers of a suitable six-layer film is shown in Figure 24 and described below.

Referring now to FIG. 24 , the barrier film 210 includes outer layers 212 , 214 . The barrier film 210 is used to prevent wood damaging organisms from entering the structure while minimizing the concentration of cyhalothrin in the soil and other surrounding environments. In one embodiment, the outer layers 212, 214 are composed of extrusion coating grade polyolefin plastomer, color concentrate, and the extruded resin described above in connection with the eight-layer film and referred to as "newly grown resin" or "NGR." Made from a blend of coating grade polyethylene. The outer layers 212, 214 may have a thickness of about 0.0005 inches (0.5 mils) to about 0.003 inches (3 mils), and may have a thickness of about 13-78 grams of material per square meter.

Inside the outer layers 212,214 are pesticide retaining layers 216,216. In one embodiment, the pesticide retaining layer is made of Saranex® ¹⁴ as described above. Layers 216 and 218 may be about 0.0005 inches (0.5 mils) to about 0.003 inches (3 mils) thick and have about 26-130 grams of material per square meter.

Inside the pesticide holding layer 216 is a structural layer 222 . In one embodiment, structural layer 222 is made of HDPE as described above. Structural layer 216 may have a thickness of about 0.002 inches (2 mils) to about 0.006 inches (6 mils), and may have about 31-93 grams of material per square meter.

Between structural layer 222 and pesticide retaining layer 218 is active layer 228 . In one embodiment, the active layer 216 is made of 0.91 wt% cyhalothrin, 0.95 wt% lamp black #6, and 22 wt% LDPE resin in an 85 wt% industrial solution. The active layer 216 may have a thickness of about 0.002 inches (2 mils) to about 0.005 inches (5 mils), and may have a thickness of about 22-115 grams of material per square meter.

The release rate of cyhalothrin in the six-layer embodiment was measured to be less than 0.002 μg/cm ² /day. The barrier film 210 is used to prevent wood damaging organisms from entering the structure while minimizing the concentration of cyhalothrin in the soil and other surrounding environment.

The present invention also provides an efficient method for fabricating multilayer barriers using conventional commercially available equipment. According to one aspect of the invention, lamp black or gas black is used in the premix to make the active layer. Lamp black imparts the desired fluidity to the premix, but unlike other types of carbon black, lamp black does not adversely affect the activity of the pesticide, such as deactivation of the pesticide. Method of making barrier film

The above-mentioned multilayer barrier film can be formed by various methods. In one approach, a carrier, such as carbon black, is mixed with polymer particles to form a mixture. One or more liquid pesticides are added to the mixture while maintaining the temperature below the decomposition temperature of the pesticide, but above the melting temperature of the pesticide to form a friable premix. The premix is melt extruded to form a thin active layer. This premix is extruded with additional layers as desired to form a barrier film. The number of layers required, the type of layers selected, the sequence of layers, and the materials used to make each layer will depend on a variety of factors including, but not limited to, the end application of the barrier film, all the properties required to prevent ingress of pests, required length, type of area and/or structure to be protected, specific species of pests, production costs and capital, etc.

The active layer can be prepared by combining the pesticide or bioactive chemical with the carrier to form a friable mixture, and adding the friable mixture to the polymer matrix. The active layer can also be prepared by mixing a polymer and a carrier to form a polymer-carrier mixture, and then adding a pesticide or biologically active chemical.

The aforementioned eight-layer barrier film 110 can be formed by the following preferred methods. To produce the active layer 128, polyethylene resin and carbon black in the form of lamp black are combined and mixed. A suitable mixer is a Marion type mixer. When using a Marion type mixer, the mixer is sealed and the agitator is turned on. The polyethylene resin and carbon black were mixed until they were well mixed and the carbon aggregates were reduced in size. The polyethylene resin is preferably in pellet form and green ground to a 35 mesh powder. The bulk temperature of the mixture is preferably kept below 60°C.

Next, the cyhalothrin was gradually added in a melt spray pattern while continuing to mix the polyethylene resin-carbon black mixture. In a preferred embodiment, an 85.2% by weight solution of technical grade cyhalothrin is used. Continued mixing directs the ingredients to mix evenly. The mixture is then stored, for example, in plastic shipping drums.

Pellets are then made by injecting the mixture into an extruder/tablet press equipped with a die. In a preferred embodiment, an extruder/tablet press equipped with a 1/8 inch strand die is used and the temperature along the barrel and die length of the extruder is maintained at about 85°C. The extruder strands may need to be cooled with water prior to pelletizing. In the preferred embodiment, pellets are made about 1/8 inch long. The pellets are subsequently dried. Dry the pellets in a hot air cyclone dryer or, if more thorough drying is desired, in a forced-air oven at 60°C in a pan.

The premix pellets were extruded and laminated between two multilayer films using lamination. Specifically, the premix pellets are extruded and laminated between two multilayer films designed to protect the bioactive premix material in the final barrier film 110 . Layer 128 may be extruded using a conventional extruder, such as a single or twin screw extruder.

Prefabricate the two multilayer films used in the lamination step. The first multilayer film comprised the layers 114 and 118 described above (ie, the pesticide retention layer made of Saranex ^(R) 14 and the adjacent NGR layer). The second multilayer film comprises the layers 112, 116, 120, 126, 114, and 118 described above (i.e., an NGR layer, an adjacent pesticide retention layer made of Saranex® ¹⁴ , an adjacent NGR layer, an adjacent HDPE layer, and an adjacent LDPE layer). The layers of the second multilayer film are oriented such that the first NGR layer (ie, layer 112) is on the outer surface of the final product.

The premix pellets were diluted with crude polyethylene resin to the desired concentration of cyhalothrin and injected into an extruder for direct lamination between the first and second multilayer films to form the barrier film 110 . In a preferred embodiment, the cyhalothrin concentration of the barrier film 110 is 0.77% by weight of the barrier film 110, or 2.75 g/m ² . The barrier film 110 is then rolled into a screen and packaged for sale or sent to be painted and stitched.

Moisture in the premix, especially from the carbon black, can cause problems during production such as foaming in the active layer 128 as it exists in the extruder die. This can be solved by drying the premix in an oven set at about 54°C for about 12 hours, which has been found to substantially dry the premix so that no foaming occurs. Care must also be taken to minimize exposure of ambient moisture to the concentrate of the premix.

In addition, carbon aggregates can form a high-quality surface in the barrier film 110 . Carbon buildup is a problem because it results in a random distribution of bioactive components (eg, cyhalothrin) in the active layer 128 . This problem can be reduced by screening the carbon black component of the fibrous web layer 122 with a 100 mesh screen prior to use. Suitable carbon black distribution can also be achieved by using high energy mixers such as Henschel type mixers and twin screw extruders, or by using a controlled batch process where high carbon content is used to increase the melt viscosity of the polymer, whereby Increased shear stress in the extruder leads to carbon distribution. Lower extruder temperatures or the use of extruders with high shear mixing sections can also result in good carbon distribution. An example of an extruder screw with a shear mixing section is a screw design with grooved barrier wires in the screw. When using this screw, the polymer melt is forced to blow through a barrier line close to the extruder barrel. This imparts high shear stress to the polymer melt, thereby increasing the distribution of carbon in the mixture.

Thermal decomposition and volatilization of cyhalothrin occurs during production at temperatures above about 160°C, and the breakthrough point at which loss of cyhalothrin becomes apparent is between about 160-170°C. In order to have the operation carried out under safe conditions, it is preferred that the operating temperature is about 150°C. A better method for off-site preformation of barrier films

The current preferred use of barrier films is to protect dwellings from termites and other crawling wood-boring pests. In order to prevent insects from entering the dwelling through the soil, the barrier film of the present invention should be placed between the soil and the foundation of the dwelling in contact with and close to the soil.

It is currently preferred to manufacture the barrier membranes of the present invention that are commercially available in sheet form that are smaller than residential foundations. Therefore, a certain number of pieces need to be combined to outline the entire foundation with the barrier film. To avoid cracks between adjacent sheets, the sheets can be sealed, glued or otherwise adhered to each other.

According to another embodiment of the present invention, the barrier film is preformed or preformed off-site before it is placed in a desired location, such as in a trench in a residential foundation. Preferably, the sheets of barrier material are combined off-site to form a pre-formed barrier that will cover the entire foundation of the dwelling, which is then shipped and installed into the trenches of the foundation. Combining the pieces into the shape of the foundation off-site reduces the chance of the pieces cracking or improperly sealing together, leaving gaps.

Figure 22 shows a preformed barrier made from a multilayer polymer film. The preformed barrier may be formed by sealing sections of the barrier. Preferably, the thermoplastic sheet used to seal the sections of the barrier is the outer layer of the multilayer barrier. However, the segments of the barrier may be formed into the desired sheet using any other method, including covering segments of thermoplastic material on adjacent barrier sheets. For example, the segments may be in the form of stripes or strips of thermoplastic material. FIG. 23 shows a trench for a foundation adapted to receive the preformed barrier of FIG. 22 .

In one embodiment of the barrier loaded with 2.75 μg of cyhalothrin per square millimeter, the barrier contains sufficient cyhalothrin per square millimeter to kill at least 24,000 individuals of T. chrysotermes. Resistance to termites and other wood pests is maintained by the membrane of the barrier, even where there are holes or cracks in the membrane of the barrier. For example, in barriers having holes or cracks with a size of 2 mm or less, contact of the termites with exposed active ingredients while passing through the holes resulted in higher termite mortality.

Not every embodiment of the present invention provides every advantage described above. Moreover, other advantages of the present invention will become apparent after studying the specification.

Example

The following examples are offered by way of illustration to further illustrate various aspects of the invention. As such, these examples are for illustrative purposes only and should not be construed as limiting the scope of the invention in any way. Example 1

Experiments were performed to determine the release rate of chlorpyrifos. The insecticide loading was either 5% or 10% by weight based on the weight of the polymer. At 50°C, the release rate was determined for all devices.

Polymers evaluated included low-melt polyethylene, polyurethane, two epoxies, silicone rubber, and low-melt polyethylene with a higher wax content to reduce thermal decomposition of chlorpyrifos. Studies have shown that chlorpyrifos undergoes extreme thermal decomposition at temperatures above about 240°C; thus, the choice of polymers is limited to formulations that do not require excessive thermal processing.

Table 1 summarizes the results of these studies. Overall, the compatibility of the polymers with chlorpyrifos did not present problems with regard to the loading rates used. However, some physical integrity is lost when using polyurethane polymers, whereas other polymer systems do not show visible degradation at 50°C. The release rate ranged from 10 μg/cm ² /day for silicone rubber to 0.3 μg/cm ² /day for epoxy resin B.

Using the data provided in Table 1, it is possible to approximate an estimated product lifetime. Assuming a device with a weight of 0.5 g and a 10% loading, 50 mg of chlorpyrifos is available for release. Thus, for a polymer system with an area of 4 cm ² , the release rate is 1 μg/cm ² /day, which is sufficient to maintain the insecticide for 30 years at elevated temperatures. These calculations show that various insecticide products are available.

Table 1. Polymer formulations and release rates of selected systems using chlorpyrifos Polymer type Chlorpyrifos content (%) Release rate (μg/cm ² /day) ^a Polyurethane 5 2.1± ^1.4b Epoxy resin A 5 <0.1 polysiloxane 5 10.3±3.5 Polyurethane 10 1.0±0.3 Epoxy resin B 10 0.3±0.1 PE+wax 10 1.9±0.3 ^a Release rate measured at 50 °C ^b Excessive cracking of the material at elevated temperatures Example 2

Studies were also carried out with a polymer system similar to Example 1, but using 80% pure pyrethrins. The release rates at 40°C are listed in Table 2.

Table 2. Polymer Formulations and Release Rates of Selected Systems Using Pyrethrin I Polymer type Pyrethrin I content (%) Release rate (μg/cm ² /day) ^a Epoxy resin A 10 0.5±0.2 polysiloxane 10 21.2±5.4 Polyurethane 10 15.7±7.1 Epoxy resin B 10 0.2±0.1 ^a Release rate measured at 40 °C

Polyurethanes and polysiloxanes had the highest release rates, while polyepoxides had the lowest release rates. Significant changes in release rates are expected to require the use of suitable binding agents.

Simple calculations from the data presented in Table 2 can determine the probable lifetime of an insecticide system. As described in Example 1, there are many variables that can change the lifetime of the exclusion zone. Example 3

Controlled release devices were made and tested to determine their rate of release. All thermoplastic polymers were formulated with 10% by weight insecticide, 3 or 7% by weight carbon black for absorbing liquid insecticide, and 83-87% by weight polymer, which were injection molded into about 1/8 inch thick Flakes. Specifically, devices made from thermoplastic polymers and deltamethrin and cyhalothrin contained 3% carbon black. While the device made from the rest of the pesticide and thermoplastic polymer contained 7 percent carbon black.

Devices made from S-113 polyurethane, a thermoset polymer, were made from a polymer mixture containing 60 wt% S-113, 40 wt% castor oil, and 5 wt% TIPA catalyst. The polymer mixture constituted 90% of the total weight of the device. The insecticide, deltamethrin, made up the remaining 10% of the installation. No carbon black was used in this device. The polymer/pesticide mixture was cast into 1/8 inch thick sheets and heated at about 60°C for about 40-60 minutes to cure the cast sheets.

One inch squares were then cut from the injection molded or cast sheets and the release rate of the squares was tested. The following release rates were obtained:

table 3 insecticide polymer release rate deltamethrin S-113 Polyurethane 25.2 μg/cm ² /day Aromatic 80A 16.8 μg/cm ² /day Pellethane 2102-80A 8.8 μg/cm ² /day Pellethane 2102-55D 8.0 μg/cm ² /day Alipmtic PS-49-100 7.2 μg/cm ² /day Cypermethrin Polyurethane 3100 0.4 μg/cm ² /day Polyurethane 2200 0.7 μg/cm ² /day EVA 763 27.3 μg/cm ² /day Polyethylene MA 778-000 4.6 μg/cm ² /day Cyhalothrin Polyurethane 3100 0.4 μg/cm ² /day Polyurethane 2200 0.7 μg/cm ² /day EVA 763 27.3 μg/cm ² /day Polyethylene MA 778-000 4.6 μg/cm ² /day Tefluthrin Polyurethane 3100 6.4 μg/cm ² /day Polyurethane 2200 25.0 μg/cm ² /day EVA 763 40.4 μg/cm ² /day Polyethylene MA 778-000 27.0 μg/cm ² /day permethrin Polyurethane 3100 1.4 μg/cm ² /day Polyurethane 2200 1.3 μg//cm ² /day EVA 763 28.5 μg/cm ² /day Polyethylene MA 778-000 4.0 μg/cm ² /day Example 4

Experiments were performed to determine the effect of cyhalothrin (pyrethroid) concentration and insecticide/polymer combination on the release rate of the insecticide from the polymer. The data are summarized in Table 4.

Table 4. Release Rates for Polymer/Pyrethroid Concentration Combinations polymer Concentration of pyrethroids (% by weight) Release rate of pyrethroids (mg/cm ² /day) Polyethylene-vinyl acetate copolymer (EVA) 1 0.3 5 2.2 10 2.5 Polyurethane 1 0.9 5 4.4 10 8.3 Polyurethane/EVA(50/50) 1 2.6 5 7.2 10 9.1 Example 5

Tests were conducted to determine the effectiveness of the exclusion zone against termites. Two types of termite samples were chosen for the test: Termites cerevisiae (because it is the most common), and Termites cerevisiae (because it is the most invasive).

Assemble the test cell with a glass container. Place wood veneers in the bottom of the container. The insecticide-impregnated polymer is placed on top of the wood chips so that there are no channels or openings from above the impregnated polymer to the wood chips. A non-nutrient auger is placed on top of the impregnated polymer. The data on the auger surface was zero and the impregnated polymer was placed 5 cm below the auger surface. Termites were placed on the surface of the auger through which they marched daily towards the marked impregnated polymer.

The combinations of impregnated polymers are listed in Table 5.

Table 5 Release rate of 10% by weight pyrethroids polymer Pyrethroids Release rate (mg/cm ² /day) Polyethylene-vinyl acetate copolymer Permethrin 3.9 Polyethylene-vinyl acetate copolymer Tefluthrin 4.3 Polyethylene-vinyl acetate copolymer Tefluthrin (2% by weight of fatty acids) 3.2 polyethylene Permethrin 1.4 polyethylene Tefluthrin 2.2 polyethylene Tefluthrin (2% by weight of fatty acids) 2.0

A reference sample without pyrethroids in the polymer barrier was also used. The results are shown in Figures 25 and 26. In all comparative experiments, termites gnawed through the polymer into the wood chips. The speed through polyethylene-vinyl acetate copolymer is slower than through polyethylene. For all impregnated polymers, there was no breakthrough. Because house termites are so invasive, they get closer to the impregnated polymer than the less invasive T. japonica. In fact, polyethylene containing permethrin is scarred by the mandibles of Formosan termites, but without holes or penetration. After about 12-14 days even the Formosan termites were repelled by the released insecticide and retreated under the action of the impregnated polymer. Example 6

Experiments were performed to demonstrate the effect of incorporation of the carrier on the release rate. The active chemical substances are tefluthrin and cyhalothrin in an amount of 5% by weight, the binding carrier is carbon black in an amount of 0% by weight and 10% by weight, and the balance is high-density polyethylene (MA 778-000 ). Release rates were measured 6 weeks after manufacture, with samples swabbed weekly to remove surface build-up of released active chemical.

The results are listed in Table 6.

Table 6 Release Rates of 0 wt% and 10 wt% Carbon Black Active Chemicals Carbon black (wt%) Release rate (μg/cm ² /day) Tefluthrin 0 3.13 Tefluthrin 10 0.71 Cyhalothrin 0 1.78 Cyhalothrin 10 0.81 Cyhalothrin 20 0.61 Example 7

This example illustrates a method of making a premix that is subsequently used to make the active layer (ie, the pesticide releasing layer) of the barrier of the invention.

Low-density polyethylene (PE XU59400 or PE XU59400.00 purchased from Dow Chemical Company) was cryogenically ground into particles with a particle size of about 35 mesh. The polyethylene particles were then mixed with Lamphei carbon (Lamphei Extra Fine #6 from General Carbon) in a Marion type mixer until the carbon dispersed in the polyethylene to form a homogeneous mixture with a dry, flowable consistency. Then, operating the mixer at an average internal temperature of about 50[deg.] C., cyhalothrin from Syngenta was added to the mixture as a melt spray. The mixer was kept agitating after the cyhalothrin was applied to obtain a homogeneous mixture. The premix contained about 3.2% by weight cyhalothrin, about 4% by weight lamp black carbon, and about 92.8% by weight low density polyethylene. The prepolymer can be placed in a forced air oven at about 60-70°C to reduce its moisture content. Example 8

A homogeneous premix having about 10.0% by weight cyhalothrin and about 11.3% by weight lampblack carbon was prepared using the procedure as described in Example 7. Example 9

The procedure described in Example 8 was used to prepare a premix, except that molten cyhalothrin was applied to the lamp black carbon as a first step, and the mixture was then mixed well to form a homogeneously mixed powder. Next, the ground low density polyethylene was added and mixed further until a uniformly dispersed mixture with a dry, flowable consistency was obtained. Example 10

The procedure as described in Example 7 was used except that an Eirich-type mixer with a high-speed stirrer was used to mix the components, with about 7.9% by weight of gas black carbon (Colour Black FW200 from Degussa) and about 9.5% by weight % cyhalothrin to prepare a premix. Example 11

Premixes were prepared according to Examples 7, 8 and 9 except that the premixes were not dried. The premix is melt extruded into strands, and the strands are cut into pellets. Example 12

Using the procedure described in Example 7, a carbon black with about 7% by weight of cyhalothrin, about 5% by weight of conductive grade carbon black (Vulcan® ^XC -72R from Cabot Corporation), and the balance of low carbon black was prepared. Premix of density polyethylene ( ^Novapol® LC-0522-A available from Nova Chemicals Canada Inc.). Example 13

The premix prepared according to Example 12 was injection molded into thin discs. The molded discs are then cut into pieces using a rotary blade re-grinder. Example 14

Following the procedure of Example 7, a premix was prepared having about 6% by weight cyhalothrin and about 94% by weight low density polyethylene. The resulting premix had a viscous consistency. Example 15

A preparation having about 2% by weight of cyhalothrin (available from Zeneca), about 1% by weight of conductive grade carbon black (available from Cabot's ^Vulcan® XC-72R), and the balance of high-density polyethylene ( A homogeneous premix of Microthene ⁽ R) MA77800) available from Quantum Chemicals.

In the first step, the carbon black is dried in a forced-air oven at a temperature of about 105°C for at least 12 hours, or until a constant weight is reached. Approximately equal weights of powdered high density polyethylene were mixed with dry carbon black in a Hobart industrial dough mixer. Then, with continuous stirring, molten cyhalothrin was slowly added to the mixture in an amount approximately twice the weight of the carbon black. The mixture was then blended with sufficient additional high density polyethylene to reduce the concentration of cyhalothrin in the mixture to about 2% by weight.

The resulting mixture was then melt extruded at about 290°C and cast as a monolayer film about 0.03 inches (30 mils) thick. Example 16

According to the steps of Example 15, about 2% by weight of cyhalothrin, about 1% by weight of conductive grade carbon black (such as ^Vulcan® XC72R available from Cabot Corporation), and the remainder of high-density polyethylene (available from Tablets of Microthene ^(R) MA77800) from Quantum Chemicals. Example 17

The procedure of Example 15 was used to prepare a sheet having about 5% by weight tefluthrin, about 2.5% by weight carbon black, and the balance high density polyethylene (Microthene® ^MA77800 from Quantum Chemical Company). Example 18

The procedure of Example 15 was used to prepare a sheet with about 5% by weight tefluthrin, about 2.5% by weight carbon black, and the balance ethylene vinyl copolymer (EVA763 from Quantum Chemical Company). Example 19

The procedure of Example 15 was used to prepare a sheet having about 10% by weight tefluthrin, about 5% by weight carbon black, and the balance high density polyethylene (Microthene® ^MA77800 from Quantum Chemical Company). Example 20

The procedure of Example 15 was used to prepare a sheet with about 10% by weight tefluthrin, about 5% by weight carbon black, and the balance ethylene-vinyl acetate copolymer (EVA763 from Quantum Chemical Company). Example 21

The procedure of Example 15 was used to prepare a sheet having about 10% by weight permethrin, about 5% by weight carbon black, and the balance ethylene vinyl copolymer (EVA763 from Quantum Chemical Company). Example 22

The procedure of Example 15 was used to prepare a sheet having about 10% by weight permethrin, about 5% by weight carbon black, and the balance high density polyethylene (Microthene® ^MA78000 from Quantum Chemical Company). Example 23

The procedure of Example 15 was used to prepare cyhalothrin with about 1 wt. % cyhalothrin, about 0.73 wt. Sheets of carbon black (Special Black 6 available from Degussa Corporation), and the balance low density polyethylene ( ^Novapol® LC-0522-A available from Nova Chemicals Canada Inc.). Example 24

Tablets were prepared using the procedure of Example 23, except that cyhalothrin was used at a concentration of about 5% by weight and carbon black at a concentration of about 3.6% by weight. Example 25

Tablets were prepared essentially as described in Example 23, except that cyhalothrin was used at a concentration of about 10% by weight and carbon black at a concentration of about 7.3% by weight. Example 26

Tablets were prepared according to Examples 23, 24 and 25. The sheets were then laminated on both sides with layers of Saranex ^(R) 14 film (available from Dow Chemical Company) using heat pressing. Example 27

The procedure of Example 15 was used to prepare a gas black carbon having about 7.9% by weight (Colour Black Co., Ltd. FW200), approximately 9.5% by weight cyhalothrin, and the balance low density polyethylene (PE XU59400 or PE XU59400.00 available from Dow Chemical Company). Example 28

Sheets comprising two layers of Saranex( ^R) 14 bonded together were prepared by melt extrusion/lamination. The tie layer consisted of the component mixture described in Example 26. As a first step, the components of the adhesive layer are prepared as a powdered premix. The premix was then melt extruded directly between two layers of Saranex® ¹⁴ at about 150°C. Example 29

This example describes a method of making an eight-layer tablet. The composition of each layer of the sheet is as follows.

layer description

1 Made of black resin (Colortech No.20413-19 available from Colortech Co., Ltd.), extrusion coated

Hierarchical polyolefin plastomer ( ^Affinity® PT1450 available from Dow Chemical Company), and thick

0.001 inch (1 mil) low-density polyethylene (available from Nova Chemicals Canada

Newly generated resin (NGR) composed of ^Novapol® LC-0522-A) from Co., Ltd. (purchased from

Fabrene Co., Ltd.) layer;

2 Composed of vinylidene chloride/vinyl chloride copolymer, low density polyethylene, ethylene/vinyl acetate copolymer,

and Saranex ^® 14 (available from

Dow Chemical Company) layer;

3 the above-mentioned NGR layer;

4 Made of high-density polyethylene ( ^Sclair® HDPE No.99G available from Nova Chemicals Company),

and carbon black resin (available from Cabot Corp.

Plasbalck ^® PE1371) fiber fabric (available from Fabrene Co., Ltd.) layer;

5 Contains black resin (available from Colortech Inc.

 Low-density polyethylene (Colortech No.20413-19) (purchased from Nova Chemicals Canada Ltd.

^Novapol® LC-0522-A) connecting layer of the company;

6 is made of gas black carbon (purchased from Degussa's Color Black FW200), cyhalothrin,

and low density polyethylene (available from Dow Chemical Company) approximately 0.002 inch (2 mil) thick

The active ingredient layer composed of the company's PE XU59400 or PE XU59400.00);

7. 14 layers of the above-mentioned ^Saranex® ;

8 The above NGR layer.

An eight-layer tablet was formed by bonding a layer of NGR (layer 1) to ^Saranex® 14 (layer 2) using extrusion coating to form a composite of layers 1-2. Another layer of NGR (layer 3) was melt extruded, and the layer 1-2 composite was bonded to the fibrous fabric sheet (layer 4) to form a layer 1-2-3 composite. A layer of low density polyethylene (layer 5) was applied to the layer 1-2-3 composite by extrusion coating to form the first outer layer.

Layer 7-8 composites were prepared by applying a layer of NGR (layer 8) to a sheet of ^Saranex® 14 layer (layer 7) using extrusion coating.

The procedure of Example 10 was used to make a premix having about 7.9 wt% gas black carbon, 9.5 wt% cyhalothrin, and the balance low density polyethylene. This premix was formed into active ingredient pellets using the procedure of Example 11. The active ingredient pellets and low density polyethylene pellets (PE XU59400 or PE XU59400.00 available from Dow Chemical Company) were mixed in a ratio of about 2:1 so that the concentration of cyhalothrin in the pellet mixture reached about 6% by weight.

The pellet mixture is fed to the extruder to melt extrusion bond the first outer layer (ie, layers 112, 116, 120, 122, and 126) and the second outer layer (ie, layers 118 and 114). A multi-layer laminate was formed with an overall thickness of approximately 0.014 inches (14 mils). The concentration of cyhalothrin in the formed laminate was about 0.9% by weight. Example 30

Except that the active layer is made of about 4% by weight of gas black carbon (Colour BlackFW200 available from Degussa Company), about 4.7% cyhalothrin, and the remainder of low-density polyethylene (PE XU59400 available from Dow Chemical Company or Except for the composition of PE XU59400.00), the procedure of Example 29 was used to prepare the sheet. The concentration of cyhalothrin in the formed laminate was about 0.5% by weight. Examples 31-37

Prepared from a premix of lampblack carbon (Lampblack Extra Fine #6 from General Carbon), cyhalothrin, and low-density polyethylene (PE XU59400 or PE XU59400.00 from Dow Chemical Company) piece. Sheets were formed into laminates using essentially the procedure of Example 29, except that the final concentration of cyhalothrin in the formed laminates is listed in Table 7 below.

Table 7 Example Lamp black carbon (weight%) Cyhalothrin (weight %) Cyhalothrin in laminate (wt%) 31 4 3.5 1 32 2 1.8 0.5 33 1 0.88 0.25 34 0.5 0.44 0.12 35 0.25 0.22 0.06 36 0.125 0.11 0.03 37 0.06 0.05 0.01 Example 38

A six-layer sheet with the following composition was formed as follows:

layer description

1 Made of black resin (Colortech No.20413-19 available from Colortech Co., Ltd.), extrusion coated

Hierarchical polyolefin plastomer ( ^Affinity® PT1450 available from Dow Chemical Company), and low

Density polyethylene (available as ^Novapol® LC-0522-A from Nova Chemicals Canada Ltd.)

A layer of newly generated resin (NGR) (available from Fabrene Ltd.) composed of

2 Composed of vinylidene chloride/vinyl chloride copolymer, low density polyethylene, ethylene/vinyl acetate copolymer,

and a layer of Saranex ^® 14 (available from Dow Chemical Company) composed of silica;

3 Constructed of high density polyethylene (Sclair® ^HDPE No. 99G from Nova Chemicals)

The fiber fabric layer of ;

4 Consisting of 0.91 wt% cyhalothrin, 0.95 wt% lamps in 85 wt% industrial solution

Black #6, and the active component layer that LDPE resin of 22% by weight constitutes;

5 14 layers of the above ^Saranex® ;

6 The above NGR layer.

The six-ply sheet is primarily used in the US Forest Service (USFS) concrete slab method. The concrete slab method accelerates the formation of cast concrete foundations. To establish the test plot, remove leaves and debris to expose a 24-inch square area on one face of the foundation. A 21 inch square wooden frame made of 1 inch by 1 inch spruce strips was placed in the center of the cleaning area and a 2.2 inch deep trench was dug directly into the treated soil. Cover with PVC pipe to reduce moisture loss and prevent rain and sun from affecting the termiticide.

The results of the concrete flat field tests at the locations described below are shown in Table 8 below.

Table 8 Place termite species % of recurrence tests not passed with six layers unprocessed Florida (USFS) Reticulitermes flavipes 100 60 Arizona (USFS) Reticulitermes flavipes 100 50 Mississippi (USFS) Reticulitermes flavipes 100 100 Malacca (USFS) Globitermes sulphureus 100 30 As shown in Table 8, none of the test fields treated with six-layer sheets was penetrated by termites.

Although the invention has been described with reference to one or more specific embodiments, those skilled in the art will recognize that many modifications can be made to the invention without departing from the spirit and scope of the invention. Each of these embodiments, and modifications thereof, consistent with the spirit of the invention are to be included within the scope of the invention as defined by the following claims.

Claims (76)

1. multilayered barrier of resisting insect, it comprises:

At least one deck agricultural chemicals releasing layer, and

At least one deck keeps layer with the agricultural chemicals of the parallel placement of described agricultural chemicals releasing layer, and described agricultural chemicals releasing layer contains at least a agricultural chemicals, and described agricultural chemicals keeps layer that very a spot of agricultural chemicals release is passed through.

2. multilayered barrier according to claim 1 is characterized in that: described agricultural chemicals keeps layer to comprise Saranex ^

3. multilayered barrier according to claim 1 is characterized in that: described two-layer agricultural chemicals keeps layer to be positioned at two offsides of described agricultural chemicals releasing layer.

4. multilayered barrier according to claim 1 is characterized in that: described agricultural chemicals keeps layer to be made by polymeric material, and described polymeric material does not allow agricultural chemicals discharge from barrier basically.

5. multilayered barrier according to claim 1 is characterized in that, described agricultural chemicals releasing layer comprises:

Polymeric matrix; And

Agricultural chemicals in the matrix.

6. multilayered barrier according to claim 5 is characterized in that: described agricultural chemicals is selected from pyrethroid, newly intends nicotine, isofenphos, sumicidin, pyrethrins and their combination.

7. multilayered barrier according to claim 5 is characterized in that: described agricultural chemicals is selected from tefluthrin, permethrin, cyhalothrin, Chryson, decis, cypermethrin, cyphenothrin, cyfloxylate, decis, chlopyrifos, ABG-6215, basudin, antiphen, methyl-isorhodanate, pentachlorophenol, tralomethrin, chlorfenapyr, fluorine worm nitrile, newly intends nicotine and their combination.

8. multilayered barrier according to claim 5 is characterized in that: described agricultural chemicals is a cyhalothrin.

9. multilayered barrier according to claim 5 is characterized in that: described polymeric matrix is made by low density polyethylene (LDPE).

10. multilayered barrier according to claim 5 is characterized in that: described polyethylene is a linear low density polyethylene (LLDPE).

11. multilayered barrier according to claim 1 is characterized in that: it also comprise one deck at least be positioned at agricultural chemicals keep layer, the bactericide releasing layer in order to prevent that barrier from being damaged by fungi.

12. multilayered barrier according to claim 1 is characterized in that: it also comprise one deck at least be positioned at agricultural chemicals keep layer, usefulness is so that barrier has intensity and resistance wears the resistance of performance and wear the intensity layer.

13. multilayered barrier according to claim 12 is characterized in that: described resistance is worn the intensity layer and is made by the macromolecular fibre fabric.

14. multilayered barrier according to claim 13 is characterized in that: described resistance is worn the intensity layer and is made by polyethylene.

15. multilayered barrier according to claim 1 is characterized in that: described agricultural chemicals is to termite, moth carpented ant and to eat into wooden insect effective.

16. multilayered barrier according to claim 1 is characterized in that: described barrier be formed on zone or structure around.

17. multilayered barrier according to claim 1 is characterized in that: the rate of release of described agricultural chemicals from barrier is less than 0.4 μ g/cm ²/ day.

18. multilayered barrier according to claim 5 is characterized in that: described matrix comprises a polymer, and it also comprises a carrier to regulate the rate of release of agricultural chemicals from matrix.

19. a manufacturing is used for the method for premix of the active layer of barrier film, the active layer of this barrier film is used to prevent that moth from entering the zone or containing wood structure, and described method comprises following steps:

(a) mixed carbon black and polymer beads form mixture;

(b) in this mixture, add one or more liquid pesticidals, form frangible premix.

20. one kind is used for preventing that moth from entering the zone or containing the multilayered barrier film of wood structure, this barrier film comprises:

Ground floor, it comprises the protectiveness resin;

The second layer, it comprises the agricultural chemicals maintenance material that prevents that basically agricultural chemicals from passing through;

The 3rd layer, it comprises the protectiveness resin;

The 4th layer, it comprises to resist wears the intensity film;

Layer 5, it comprises cohesive polymers;

Layer 6, it comprises the polymeric matrix that contains carbon black and one or more agricultural chemicals;

Layer 7, it comprises agricultural chemicals and keeps material;

The 8th layer, it is made by the protectiveness resin, and wherein, agricultural chemicals is higher than the speed that agricultural chemicals discharges from the speed that layer 6 discharges into other layer from barrier film, and does not have agricultural chemicals to discharge from barrier film itself basically.

21. barrier film according to claim 20 is characterized in that: described protectiveness resin is polyolefin plastomers, colored concentrate and poly mixture.

22. barrier film according to claim 20 is characterized in that: described protectiveness resin provides ultraviolet protection to barrier.

23. barrier film according to claim 20 is characterized in that: described agricultural chemicals keeps material to prevent that basically agricultural chemicals from discharging from barrier film.

24. barrier film according to claim 20 is characterized in that: described second and the material of layer 7 be that fusing point is higher than about 143 ℃ polymer, and can biological degradation and light degradation.

25. barrier film according to claim 20 is characterized in that: described second and the material of layer 7 comprise Saranex ^14.

26. barrier film according to claim 25 is characterized in that: described Saranex ^14 are made of low density polyethylene (LDPE), vinylidene chloride/vinyl chloride copolymer, ethylene and silica.

27. barrier film according to claim 20 is characterized in that: described the 3rd layer resin is polyolefin plastomers, colored concentrate and poly mixture.

28. barrier film according to claim 20 is characterized in that: make by the high density polyethylene (HDPE) fabric for described the 4th layer.

29. barrier film according to claim 20 is characterized in that: described layer 5 comprises the low density polyethylene (LDPE) that fusing point is about 165 ℃.

30. barrier film according to claim 20 is characterized in that: the carbon black of described layer 6 is dim.

31. barrier film according to claim 20 is characterized in that: the polymeric matrix of described layer 6 comprises low density polyethylene (LDPE).

32. barrier film according to claim 20 is characterized in that: the polymeric matrix of described layer 6 comprises the low density polyethylene (LDPE) of metallocene catalysis.

33. barrier film according to claim 31 is characterized in that: the fusing point of described low density polyethylene (LDPE) is about 80 ℃.

34. barrier film according to claim 20 is characterized in that: the amount of at least a agricultural chemicals in the described layer 6 can make it can not exhaust in about 10 years.

35. barrier film according to claim 20 is characterized in that: at least a agricultural chemicals in the described layer 6 accounts at least 5% of layer 6 weight.

36. barrier film according to claim 20 is characterized in that: at least a agricultural chemicals in the described layer 6 accounts at least 10% of layer 6 weight.

37. barrier film according to claim 20 is characterized in that: at least a agricultural chemicals in the described layer 6 is a cyhalothrin.

38. according to the described barrier film of claim 37, it is characterized in that: the cyhalothrin in the described layer 6 exists with the amount of every square metre of barrier film at least about 2.75g.

39. barrier film according to claim 20 is characterized in that: at least a agricultural chemicals in the described layer 6 is the biologically active chemical substance of low volatility.

40. barrier film according to claim 20 is characterized in that: at least a agricultural chemicals in the described layer 6 is selected from pyrethroid, isofenphos, sumicidin, cypermethrin, pyrethrins, ABG-6215, chlopyrifos, basudin, methyl-isorhodanate, pentachlorophenol, tralomethrin and their combination.

41. barrier film according to claim 20 is characterized in that: at least a agricultural chemicals in the described layer 6 is selected from tefluthrin, permethrin, cyhalothrin, Chryson, decis, cypermethrin, cyphenothrin, cyfloxylate, decis, chlopyrifos, ABG-6215, basudin, antiphen, methyl-isorhodanate, pentachlorophenol, tralomethrin, chlorfenapyr, fluorine worm nitrile, newly intends nicotine and their combination.

42. barrier film according to claim 20 is characterized in that: at least a agricultural chemicals in the described layer 6 is selected from thiophene worm piperazine, Nitenpyram, Imidacloprid, thiophene worm amine, pyridine worm miaow, thiophene worm quinoline and their combination.

43. barrier film according to claim 20 is characterized in that: described layer 6 is by mixing described agricultural chemicals and carbon black, forms friable mixture, and adds this friable mixture make in described polymeric matrix.

44. barrier film according to claim 20 is characterized in that: described layer 6 comprises at least a agricultural chemicals that mixes at least a bactericide.

45. according to the described barrier film of claim 44, it is characterized in that: described bactericide is selected from trichloronitromethane, methyl-isorhodanate and 1, the mixture of 3-dichloropropane, N-methyl dithiocarbonic acids sodium, 2,3,5,6-tetrachloro-1,9-benzoquinones, nitrolim, biphenyl, copper naphthenate, antiphen, fentin hydroxide and their combination.

46. barrier film according to claim 20 is characterized in that: described polymeric matrix accounts for the about 77% of layer 6 weight, and layer 6 accounts for about 23% of barrier film weight.

47. barrier film according to claim 20 is characterized in that: described carbon black accounts for about 11% of layer 6 weight.

48. barrier film according to claim 20 is characterized in that: described polymeric matrix is hydrophobic.

49. barrier film according to claim 20 is characterized in that: the thickness of hydrophobic barrier film is about 0.010-0.030 inch.

50. one kind is used for preventing that moth from entering the zone or containing the multilayered barrier of wooden structures, this barrier film comprises:

Ground floor, it comprises the protectiveness resin, and this protectiveness resin comprises polyolefin plastomers, colored concentrate and poly mixture;

The second layer, it comprises the agricultural chemicals maintenance material that prevents that basically agricultural chemicals from passing through;

The 3rd layer, it comprises the protectiveness resin, and this protectiveness resin comprises polyolefin plastomers, colored concentrate and poly mixture;

The 4th layer, it comprises to resist wears the intensity film, and this resistance is worn the intensity film and comprised high density polyethylene (HDPE);

Layer 5, it comprises low density polyethylene (LDPE);

Layer 6, it comprises the polymeric matrix that contains carbon black and one or more agricultural chemicals;

Layer 7, it comprises agricultural chemicals and keeps material;

The 8th layer; it is made by the protectiveness resin; this protectiveness resin comprises polyolefin plastomers, colored concentrate and poly mixture; wherein; agricultural chemicals is higher than the speed that agricultural chemicals discharges from the speed that layer 6 discharges into other layer from barrier film, and does not have agricultural chemicals to discharge from barrier film itself basically.

51. according to the described barrier film of claim 50, it is characterized in that: described agricultural chemicals keeps material to comprise Saranex ^14.

52. according to the described barrier film of claim 50, it is characterized in that: described carbon black is dim.

53. a method of making barrier film, described method comprises following steps:

Mixed carbon black and polymer beads form mixture;

In this mixture, add one or more liquid pesticidals, keep the temperature of this mixture to be lower than the temperature that agricultural chemicals decomposes simultaneously, but be higher than the fusion temperature of agricultural chemicals, form frangible premix;

Premix is melt extruded, form thin active layer;

Premix is extruded with first and second protectiveness resin, multilayer film, low density polyethylene (LDPE) and fabric, formed eight layers barrier film, wherein:

Ground floor, it comprises the first protectiveness resin;

The second layer, it comprises the agricultural chemicals maintenance film that prevents that basically agricultural chemicals from passing through;

The 3rd layer, it comprises the second protectiveness resin;

The 4th layer, it comprises fabric;

Layer 5, it comprises low density polyethylene (LDPE);

Layer 6, it comprises an active layer, and this active layer contains the mixture of polymeric matrix, carbon black and one or more agricultural chemicals of layer 6;

Layer 7, it comprises agricultural chemicals and keeps film;

The 8th layer, it comprises the first protectiveness resin makes, and wherein, agricultural chemicals is higher than the speed that agricultural chemicals discharges from the speed that layer 6 discharges into other layer from barrier film, and does not have agricultural chemicals to discharge from barrier film itself basically.

54. according to the described barrier film of claim 53, it is characterized in that: described agricultural chemicals keeps film to comprise Saranex ^14.

55. according to the described barrier film of claim 53, it is characterized in that: described carbon black is dim.

56. according to the described barrier film of claim 53, it is characterized in that: described carbon black is a channel black.

57. a multilayered barrier that tackles insect, it comprises:

At least one deck comprises the agricultural chemicals releasing layer of polymeric matrix, and this matrix comprises agricultural chemicals and carrier, described matrix and the release of carrier control agricultural chemicals from matrix;

The two-layer agricultural chemicals that is positioned at two offsides of described agricultural chemicals releasing layer keeps layer, and described agricultural chemicals releasing layer contains at least a agricultural chemicals, and described agricultural chemicals keeps layer that very a spot of agricultural chemicals release is passed through.

58. according to the described multilayered barrier of claim 57, it is characterized in that: described agricultural chemicals keeps layer to comprise Saranex ^

59. according to the described multilayered barrier of claim 57, it is characterized in that: described agricultural chemicals keeps layer to be made by polymeric material, and described polymeric material does not allow agricultural chemicals discharge from barrier basically.

60. according to the described multilayered barrier of claim 57, it is characterized in that: it is about 0.001-0.005 inch that described agricultural chemicals keeps the thickness of layer.

61. according to the described multilayered barrier of claim 57, it is characterized in that: described agricultural chemicals is selected from pyrethroid, newly intends nicotine, isofenphos, sumicidin, pyrethrins and their combination.

62. according to the described multilayered barrier of claim 57, it is characterized in that: described agricultural chemicals is selected from tefluthrin, permethrin, cyhalothrin, Chryson, decis, cypermethrin, cyphenothrin, cyfloxylate, decis, chlopyrifos, ABG-6215, basudin, antiphen, methyl-isorhodanate, pentachlorophenol, tralomethrin, chlorfenapyr, fluorine worm nitrile, newly intends nicotine and their combination.

63. according to the described barrier film of claim 57, it is characterized in that: described agricultural chemicals is selected from thiophene worm piperazine, Nitenpyram, Imidacloprid, thiophene worm amine, pyridine worm miaow, thiophene worm quinoline and their combination.

64. according to the described multilayered barrier of claim 57, it is characterized in that: described agricultural chemicals is a cyhalothrin.

65. according to the described multilayered barrier of claim 57, it is characterized in that: described polymeric matrix is made by low density polyethylene (LDPE).

66. according to the described multilayered barrier of claim 65, it is characterized in that: described polyethylene is a linear low density polyethylene (LLDPE).

67. according to the described multilayered barrier of claim 57, it is characterized in that: described carrier is dim.

68. according to the described multilayered barrier of claim 57, it is characterized in that: the thickness of described agricultural chemicals releasing layer is about 0.001-0.005 inch.

69. according to the described multilayered barrier of claim 57, it is characterized in that: described agricultural chemicals releasing layer also comprises at least a bactericide, described bactericide is selected from trichloronitromethane, methyl-isorhodanate and 1, the mixture of 3-dichloropropane, N-methyl dithiocarbonic acids sodium, 2,3,5,6-tetrachloro-1,9-benzoquinones, nitrolim, biphenyl, copper naphthenate, antiphen, fentin hydroxide and their combination.

70., it is characterized in that according to the described multilayered barrier of claim 57: it also comprise one deck at least be positioned at agricultural chemicals keep layer, the bactericide releasing layer in order to prevent that barrier from being damaged by fungi.

71., it is characterized in that according to the described multilayered barrier of claim 57: it also comprise one deck at least be positioned at agricultural chemicals keep layer, usefulness is so that barrier has intensity and resistance wears the resistance of performance and wear the intensity layer.

72. according to the described multilayered barrier of claim 71, it is characterized in that: described resistance is worn the intensity layer and is made by the macromolecular fibre fabric.

73. according to the described multilayered barrier of claim 71, it is characterized in that: described resistance is worn the intensity layer and is made by the high density polyethylene (HDPE) fabric.

74. according to the described multilayered barrier of claim 57, it is characterized in that: the thickness on described barrier film is about 0.010-0.030 inch.

75. according to the described multilayered barrier of claim 57, it is characterized in that: it also comprises one deck protective layer at least, and ultraviolet light is avoided on the protection barrier film, and provides sealing to the barrier film.

76. according to the described multilayered barrier of claim 75, it is characterized in that: the layer of described protectiveness is made by the sealable polymer of heat.

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