WO2007019148A2 - Urethane foam compositions for pest control - Google Patents

Abstract

A curable polyurethane foaming composition contains a microencapsulated pesticide and flexible foams prepared therefrom. The composition is a mixture that reacts to form a polyurethane flexible foam and at least one microencapsulated pesticide. The composition is suitable for applicaiton to various substrates. Suitable components that react to form a polyurethane flexible foam include polyisocyanate material, an active hydrogen-containing material and a blowing agent. A curable, two-part polyurethane flexible foam forming composition adapted to cure under ambient conditions includes a polyisocyanate, a polyol, a blowing agent, and a microencapsulated pesticide.

Description

URETHANE FOAM COMPOSITIONS FOR PEST CONTROL

Field of the Invention

[0001] The field of the invention relates to polyurethane flexible foam forming compositions, methods for treating substrates with the compositions and methods for using such compositions to control pests.

Background

[0002] Termites invade houses in their search for cellulosic foodstuffs. The damage to US properties is put at about $1 billion per annum. Various methods have been used to protect buildings from being infested with termites, and many more methods used to rid the buildings of termites once infested.

[0003] The market has historically been dominated by pre-construction intensive spray application of long residual pesticides on to a foundation soil surface prior to the laying of the concrete slab over a plastic sheet such as a Damp-Proof Membrane-DPM, vapor barrier, vapor retarder or the like. Such pesticides as organo-phosphates-eg chlorpyrifos, pyrethroids (e.g. cypermethrin and lambda cyhalothrin) have been employed. More recently, products such as imidacloprid and fϊpronil have been employed. Other, more environmentally acceptable, methods of termite-proofing a dwelling place have also been developed such as establishing physical barriers to termite entry (e.g. stainless steel mesh underlays, thick paints, composite materials). These have usually not contained pesticides.

[0004] Baiting is another method to control termites. Bait stations are installed underground around the perimeter of the house, for example, every 10 to 20 feet and 2 feet out from the house. This method takes considerable time to eliminate a colony of up to one year. It relies upon individual termites feeding on the bait which contains a non-repellant termiticide (e.g. hexaflumuron, sulfluramid), and returning to the colony to pass the poison on to other members, killing a portion of the exposed colony. However, termites that are not attracted to the bait may seek out wood in the building to feed on.

[0005] Other technologies include the use as a barrier of manufactured plastic films or composite film sheets that incorporate a termiticide (e.g. lambda cyhalothrin). Drawbacks with this concept include long (and therefore costly) installation times and difficulty with sealing effectively what are termed "ground penetrations". These ground penetrations arise as a result of having to install piping (for water, heating, waste disposal) underground that rise up through the hardcore base of the building sub-structure and come into the building. Sealing these penetrations against termite entry is a key component of such systems and requires the careful installation of shaped polymer articles of the same composition. When carried out carefully by expert installation engineers, the whole barrier is extremely effective in preventing termite access to a house though the concrete sub-floor slab. However, unless sufficient care is taken, gaps or openings in joints would be inevitable, allowing for points of termite passage. This process is obviously time consuming and therefore expensive.

[0006] In addition, methods are reported that involve application of settable or curable barrier materials to building components such as spraying a mixture of a quick setting liquid monomer and a pesticide (e.g. lambda cyhalothrin), which forms a bonded polyurethane coating upon curing. One such method may be practiced as a two part system utilizing monomers and catalytic curing agents, and a one part system utilizing masked isocyanates. However, the retention and stability of the pesticide in the formed coating, the resistance and residual effectiveness of the barrier to pest attack, and the exposure of workers, residents and occupants to pest control substances are not always completely satisfactory.

[0007] Accordingly, there exists a need for an easily installed pest resistant foam or barrier that offers similar benefits of low environmental impact with long residual effectiveness against fungi, insects and representatives of the order acarina including termites, wood-boring ants, wood-boring insects and spiders.

Summary of the Invention

[0008] The present invention is directed to a curable polyurethane flexible foam forming composition containing a microencapsulated pesticide, flexible foams prepared therefrom, and methods of making the same.

[0009] In one aspect, the curable polyurethane flexible foam forming composition of the invention is a mixture of one or more components that react to form a polyurethane flexible foam and at least one microencapsulated pesticide, which composition is suitable for application to various substrates. Suitable components that react to form a polyurethane flexible foam include at least one polyisocyanate material, at least one active hydrogen- containing material and at least one blowing agent.

[0010] More specifically, in one embodiment, the present invention provides a curable, two- part polyurethane flexible foam forming composition adapted to cure under ambient conditions comprising a mixture of (A) at least one polyisocyanate, (B) at least one polyol, (C) at least one blowing agent and (D) at least one microencapsulated pesticide.

[001 1] The foam forming compositions of the invention containing microencapsulated pesticides are usually significantly lower in their acute toxicities to non-targets (e.g. humans) than are non-encapsulated pesticide products thereby allowing easier safe handling of the compositions and incorporation of pesticides without significant operator health concerns. Moreover, the controlled release characteristics of such foam forming compositions containing microencapsulated pesticides allow for greater flexibility in overall product design and polymer selection to achieve the desired pesticide release characteristics.

[0012] In accordance with the invention, the microencapsulated pesticides can be premixed with the polyisocyanate or with the polyol component or they can be added separately to the reaction mixture as it is being applied to a target substrate.

[0013] The inventive foaming composition may also contain polymerization catalysts, antimicrobial agents, non-encapsulated pesticides, or other additives such as rheology control agents, plasticizers, thickeners, surfactants, pigments, fillers, dispersants, freeze-thaw stabilizers, flame retardants and coalescents.

[0014] The compositions of the invention are particularly suitable for use in a method for reducing or preventing pest attack or pest infiltration of substrates or loci that are susceptible or vulnerable to such attack or infiltration, which method comprises (I) providing a reaction mixture of at least one microencapsulated pesticide and one or more components that react to form a polyurethane flexible foam (such as at least one polyisocyanate, at least one polyol and at least one blowing agent), (II) applying the mixture to the susceptible substrate or locus; and (III) foaming the mixture under ambient conditions to form a polyurethane flexible foam on the substrate or in the locus. In one embodiment, a coating of the foam is formed on a target substrate such as a construction material (e.g., concrete), a plastic vapor barrier or a utility penetration such as a pipe or conduit. In another embodiment, a foam is formed in a pest susceptible locus such as a wall void or bath trap.

[0015] The flexible foaming compositions of the invention can be applied to target substrates and loci by professionals or non-professionals by spraying, painting, rolling, or brushing, before, during, or after construction and may be formulated to provide flexible foams having effectiveness against fungi, wood destroying microorganisms, insects and representatives of the order acarina, including, for example, arthropods such as termites, wood-boring ants, wood-boring insects and spiders.

Definitions

[0016] In the ensuing detailed description, certain terms as well as certain terminology (generally known by those skilled in the art) will be utilized for purposes of conciseness, and for otherwise elucidating the features and advantages of the present invention. Such terms are either defined as follows or are otherwise intended to mean the following.

[0017] The term "ambient temperature" shall be understood to mean a temperature of from about 0 degrees Celsius to about 50 degrees Celsius; or particularly from about 15 degrees Celsius to about 32 degrees Celsius; or more particularly from about 20 degrees Celsius to about 25 degrees Celsius.

[0018] The term "curing under ambient conditions" shall be understood to mean a foam curing reaction that takes place at ambient temperatures without the addition of external heat. As the curing reaction itself is exothermic, it will be understood that the temperature of the reaction mixture per se may temporarily exceed ambient temperatures during curing due to the exothermic nature of the chemical reaction occasioned by the formation of the urethane foam.

[0019] The term "high-solids" shall be understood to mean foaming systems with a solids content exceeding 85 wt %.

[0020] The term "microencapsulated insecticide" is understood to refer to small solid particles or liquid droplets of a compound which has a lethal effect on insects of a type to be controlled (namely that the application of an appropriate amount of such compound results in death of a substantial portion of the insects being treated) coated with a thin film of a polymer coating or shell material. In general, the term microencapsulated insecticide is used to describe particles with diameters between 0.05 and 1000 μm. In one embodiment, suitable microencapsulated insecticides have and average particle size of from about 1 to 50 μm.

[0021] As used herein, the term "monomer" means a polymerizable molecule that forms a basic repeating unit in a polymer chain. "Oligomer" refers to a polyfunctional polymerized compound whose backbone is formed from 2 to 10 monomers. "Prepolymer" refers to a polyfunctional polymerized compound whose backbone is formed from more than 10 monomers, but has a viscosity or can be made to have a viscosity at ambient temperatures that is suitable for foaming.

[0022] The term "pest" includes fungi and other wood decaying microorganisms, insects and representatives of the order acarina, including arthropods such as termites, ants, other wood boring insects and spiders. Specific species of such pests are defined in more detail below.

[0023] The term "pesticide product" refers to the combination of active and inert constituents associated with a microencapsulated pesticide that is used alone or in combination with one or more non-encapsulated pesticides.

[0024] The expression "polyurethane foam" or "foam" as used herein refers to cellular products as obtained by reacting polyisocyanates with isocyanate-reactive hydrogen containing compounds, using foaming agents, and in particular includes cellular products obtained with water as reactive foaming agent (involving a reaction of water with isocyanate groups yielding urea linkages and carbon dioxide and producing polyurea-urethane foams) and/or with highly volatile organic substances as non-reactive foaming (blowing) agents, and with active hydrogen-containing materials such as polyols as isocyanate-reactive compounds.

[0025] As used herein, the term "flexible" in the context of the present application is defined as is customary in the art and refers to polyurethane foams that show a relatively high resilience. In particular, the term "flexible" as used herein in reference to polyurethane foams of the invention, refers to a foam having a percent recovery of at least 50%, specifically at least 70% and more specifically 80% in at least one of the three dimensional directions.

[0026] In accordance with the invention, the percent recovery of suitable foams is measured according to the following protocol: Test equipment

• Foam of prescribed dimension: 50mm x 50mm x 25mm slab of foam cut form a larger slab to exclude external surfaces from the casting process.

• Stevens QTS 25 Penetrometer

• Penetration probe: 5mm diameter 20mm length plastic probe

Programme

[0027] Programme sets penetration rate to be 30mm/min with a trigger value of Ig and a target depth of 10mm. This results in a stepped programme whereby the loading on the probe is increased to ensure a penetration depth of 10mm up to a maximum loading of 25Kg (applied to the probe). On completion of the penetration, or on reaching a maximum load of 25Kg, the probe is retracted at the same rate. The depth of the resultant depression is measured after 5 minutes. The recovery height is then the difference between the penetration depth (usually 10mm) and the depth of the remaining depression, as measured above. The result is calculated as the % recovery of the maximum penetration depth (usually 10mm unless the foam is so rigid that the probe cannot be forced into the sample).

Temperature: ambient laboratory temperature (23± 2^°C). Recorded.

Data interpretation

[0028] Typically, acceptable flexible foam shows a 10mm indentation with a loading of <2kg, often < lkg. Acceptable products show recovery of foam height to at least 50% of the original indentation depth on removal of pressure, in particular products show recovery to at least 70% and more particularly products show recovery to at least 80%.

[0029] Brittle, non-flexible foam requires > 2kg, typically 5-25kg to produce a 10mm depression. At these high levels of loading, the foams are seen to be compressed more or less irreversibly due to fracture and/or crushing of the foam structure. These products are deemed unsatisfactory.

[0030] Should a foam sample be so rigid that no or insufficient (< 10mm) indentation can be achieved at 25kg (maximum loading) the product is also deemed unsatisfactory (due to inflexibility).

[0031 ] The term "two-part" as used herein in reference to flexible foaming compositions of the invention relates to compositions having at least two parts including (A) a polyisocyante material in a first part, (B) a polyol in a second part, (C) a blowing agent and (D) the above- described microencapsulated pesticide in said first or said second part, or optionally in one or more additional parts as desired (such as a separate pesticide containing part, for example), the two (or more) parts being intended to be mixed together prior to use.

[0032] A number of additional terms are defined further below, throughout the body of this patent specification. Description of Specific Embodiments

[0033] While the present invention is susceptible to several embodiments in various forms, there is wherein below described in detail certain specific embodiments, with the understanding that the present disclosure is to be considered as merely an exemplification of the present invention, without limitation to the specific embodiments or examples discussed.

[0034] In accordance with one aspect of the present invention, it has been discovered that polyurethane flexible foams containing microencapsulated pesticides have improved pesticide retention and a concomitant resistance to wood pests such as termites, wood-boring ants, wood-boring insects, spiders, fungi and wood destroying microorganisms.

[0035] The pest resistant polyurethane flexible foams are prepared from a polyurethane reaction system comprising (i) a mixture of one or more components that react to form a polyurethane flexible foam and (ii) at least one microencapsulated pesticide. The system is suitable for application to various target substrates and loci by applying a layer or layers of such system thereto. Suitable components that react to form a polyurethane flexible foam include at least one polyisocyanate material, at least one active hydrogen-containing material and at least one blowing agent.

[0036] In one embodiment, a two-part, polyurethane flexible foaming composition adapted to cure under ambient conditions is provided which comprises: (A) at least one polyisocyanate, (B) at least one polyol, (C) at least one blowing agent and (D) at least one microencapsulated pesticide.

[0037] In accordance another aspect of the present invention, it has been discovered that the release rate of pesticides from coated substrates or target loci can be better controlled by applying to a target substrate or locus a flexible foaming composition comprising a mixture of at least one polyisocyanate, at least one polyol, at least one blowing agent and at least one microencapsulated pesticide, which mixture is foamable under ambient conditions to form a microencapsulated pesticide containing polyurethane flexible foam on the substrate or in the locus.

[0038] Accordingly, in one embodiment, the present invention provides a high-solids pesticidal flexible foaming composition comprising a reactive mixture of: (A) at least one polyisocyanate, (B) at least one polyol, (C) at least one blowing agent and (D) a pesticidally effective amount of at least one microencapsulated pesticide, which composition is foamable under ambient conditions and wherein the microencapsulated pesticide within flexible foams prepared therefrom is effective to reduce or prevent pest attack or pest infiltration of the target substrate or locus.

[0039] Any known system for producing polyurethane flexible foams may be used as a starting point for the pesticidal flexible foaming compositions of the invention, such as those set forth in the chapter on Foamed Plastics by Kyung W. Suh. (Section 5.1 Flexible Polyurethane and references cited therein) of the Kirk-Othmer Encyclopedia of Chemical Technology Copyright © 2002 by John Wiley & Sons, Inc. In accordance with the invention, such base formulations will be modified to include a pesticidally effective amount of a microencapsulated pesticide.

[0040] For example, according to the present invention, each of the components are mixed together in a mixing chamber. In one embodiment, each of the components is separately introduced into the mixing chamber. For example, each of the components can be introduced as a separate stream into the mixing chambers. Moreover, any means which is recognized in the art, such as a variable speed pump, can be employed to separately control the flow of each of the components into the mixing chamber in order to provide the desired product.

[0041] In an alternative embodiment, one or more of the components can be premixed prior to introduction into the mixing chamber. As an example, the polyols (or polyisocyanates) and a microencapsulated pesticide can be premixed and introduced to the mixing chamber as one component. It is possible to combine all of the ingredients other than the diisocyanate (or polyol) and introduce just two components to the mixing stream. It also is possible to pre- react the diisocyanate with at least a portion of the polyol. The pre-polymer is then introduced to the mixing chamber along with the other components, either singularly or premixed, to produce a flexible foam. Since an extra step is involved, the resulting foam is usually more expensive.

[0042] These processes described are not meant to be limiting to the present invention. Other methods of processing the materials described are known to those skilled in the art.

[0043] For example, prior to, or concurrent with application (e.g., spraying, painting, brushing, etc.) the polyurethane flexible foaming system is mixed with a pesticidally effective amount of a suitable microencapsulated pesticide. The microencapsulated pesticide is selected to impart pest resistive properties to the final flexible foam and covered substrate or treated locus as required under the prevailing circumstances. In one embodiment, a pre-mix of the microencapsulated pesticide with the polyol, blowing agent, catalyst (if used) and other ingredients (except the polyisocyanate) is prepared which is suitable to package, sell and ship and is suitable for use in a multi-component (e.g., two-part) polyurethane foaming system. It is therefore advantageous to pre-mix the microencapsulated pesticide with the active hydrogen (polyol) component and, optionally, other additives such as a blowing agent, catalyst or reaction accelerator in a composition which is substantially free of isocyanate functional compounds. However, a pre-mix of the microencapsulated pesticide with the polyisocyanate and other ingredients (except the polyol) is also within the scope of the invention.

[0044] It is advantageous to provide a two part system as a co-package or in a dispenser having a static mixer or the like that is suitable for shipping and/or selling which comprises a first pre-mix (A) containing at least one polyisocyanate material which is substantially free of active hydrogen compounds, a second pre-mix (B) containing at least one polyol which is substantially free of isocyanate functional compounds, and wherein at least one of the first or the second pre-mixes contain (C) at least one microencapsulated pesticide. In one embodiment, a pesticidally effective amount of the microencapsulated pesticide is present in only one of the pre-mixtures. In another embodiment, both pre-mixes in the co-pack contain a portion of the total pesticidally effective amount of the microencapsulated pesticide. In another aspect, the polyisocyanate, polyol and microencapsulated pesticide are provided in separate premixes in a tri-pack configuration.

[0045] To apply the polyurethane system, the two pre-mixes are mixed together immediately prior to application (such as by spraying or brushing) to prevent the clogging of the application equipment. In one embodiment, the two parts are combined within the nozzle of a pressurized spraying device. A great variety of suitable spraying devices are suitable for the practice of the present invention. These devices are well understood by those having skill in the art. For example, one spray configuration employs a dispensing gun and associated container pumps actuated by compressed air (e.g., 110 psi). Each container (such as a 55 gal. drum) contains one part of the two-part system, with at least one part containing a microencapsulated pesticide. The dispensing gun cartridge assembly contains a mixing chamber, where the two parts are combined under pressure. In one embodiment, the parts are mixed in substantially stochiometric amounts and, in particular, at a 1:1 ratio. [0046] Accordingly, in one embodiment of the present invention wherein a two part system is provided, suitable spraying devices allow the pre-mixes to be combined within the nozzle by directing at least two liquid feed streams into the spraying nozzle. It will be understood that three liquid feed streams will be provided in systems having a tri-pack configuration.

[0047] As noted above, the present invention contemplates a two (or more) part system wherein a first part comprising at least one active hydrogen-containing material is combined with a second part comprising at least one polyisocyanate material to form the pest resistant polyurethane flexible foam, wherein either one or both of the parts contains a microencapsulated pesticide. This may be accomplished simply by applying the two (or more) parts to the target substrate or locus to be protected sequentially; first with the active hydrogen-containing material mixture and then with the second part containing the polyisocyanate material. However, it is also within the scope of invention to combine the two or more components in a single spray, brush or spread application. The combined parts are curable under ambient conditions to form a polyurethane flexible foam containing a pesticidally effective amount of a microencapsulated pesticide. The reaction proceeds readily at ambient temperature and is exothermic.

[0048] In one embodiment, suitable polyurethane formulations will have a viscosity that is acceptable for foaming. For foaming purposes, it is beneficial that the viscosity at ambient temperature be within the range of 100 to 10,000 cP, particularly 500 to 1,000 cP, to provide a foaming composition which penetrates and spreads adequately within a locus or over the surface of a substrate being coated. More viscous compositions may be made less viscous by the addition of compatible solvents (both inert and reactive). In the practice of the invention, suitable inert solvents include fully etherified or esterified glycol ethers, , the acetates, xylene, toluene and methyl isobutyl ketone. Suitable reactive solvents include the lower molecular weight diols such as ethylene glycol, diethylene glycol, 1,4-butane diol, 1,6-hexane diol, and 1,10-decane diol and the lower molecular weight oligomers of ethylene, propylene and butylene glycol, for example, polyethylene glycol 400 or polypropylene glycol 425. The solvents may be present in an amount of up to about 15% by weight and more particularly from about 10 to 15% by weight of the entire composition.

[0049] In one embodiment, the compositions are substantially free of added volatile organic solvents (those skilled in the art will appreciate that microencapsulated pesticides used in the foamable compositions of the invention may contain some organic solvent and that this is considered to not be a constituent of added solvent). [0050] To further illustrate suitable formulations, suitable polyisocyanates include aromatic, aliphatic, and cycloaliphatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate ("MDI"), toluene diisocyanate ("TDI"), xylylene diisocyanate, tetramethylxylene diisocyanate, naphthalene diisocyanate, para-phenylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, mixtures thereof, and the like. Polymeric polyisocyanates, biurets, blocked polyisocyanates, and mixtures of polyisocyanates with melting point modifiers can also be used. MDI is a particularly preferred polyisocyanate. A suitable commercially available polymeric diphenylmethane diisocyanate is "Rubinate M" polyisocyanate (Huntsman Polyurethanes).

[0051] The polyol component comprises more than one polymerizable OH (hydroxyl) functional compounds, suitably comprising two or more hydroxyl groups, per molecule on average. The polymerizable, hydroxyl functional compounds may be aliphatic and/or aromatic. The polymerizable, hydroxyl functional compounds may be straight, cyclical, fused, and/or branched. Particular, polymerizable hydroxyl functional compounds include at least one diol, at least one triol, and/or at least one tetrol. Any of these polyol compounds may be monomelic, oligomeric, and/or polymeric as desired. If oligomeric and/or polymeric, the polyol(s) may be selected from one or more hydroxyl functional polyethers, polyesters, polyurethanes, polyacrylics, epoxy resins, polyamides, polyamines, polyureas, polysulfones, castor oil, combinations of these, or the like. Polyether polyols such as the polyalkylene ether and polyester polyols may be mentioned as these are commercially available at relatively low cost and are hydrolytically stable.

[0052] Suitable polyalkylene ether polyols include the poly(alkylene oxide) polymers such as poly(ethylene oxide) and poly(propylene oxide) polymers and copolymers with terminal hydroxyl groups derived from polyhydric compounds, including diols and triols; for example, ethylene glycol, propylene glycol, 1 ,3-butane diol, 1 ,4-butane diol, 1 ,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, diglycerol, trimethylol propane and similar low molecular weight polyols. Suitable commercially available polyether polyols include those sold under the trade name Voranol^® (The Dow Chemical Company).

[0053] The polyester polyols which are suitable in accordance with the invention include the known polycondensates of organic dihydroxy and optionally polyhydroxy (trihydroxy, tetrahydroxy) compounds and dicarboxylic and also optionally polycarboxylic (tricarboxylic, tetracarboxylic) acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids it is also possible to use the corresponding polycarboxylic anhydrides or corresponding polycarboxylic esters of lower alcohols to prepare the polyesters such as, for example, phthalic anhydride. Examples of suitable diols are ethylene glycol, 1 ,2-butanediol, diethylene glycol, triethylene glycol, polyalkylene glycols, such as polyethylene glycol, and also 1,2- and 1,3-propanediol, 1 ,4-butanediol, 1,6-hexanediol, neopentyl glycol or neopentyl glycol hydroxypivalate. Examples that may be mentioned of polyols having 3 or more hydroxyl groups in the molecule, which may be used additionally, if desired, include trimethylolpropane, trimethylolethane, glycerol, erythritol, pentaerythritol, di- trimethylolpropane, dipentaerythritol, trimethylol-benzene or trishydroxyethyl isocyanurate.

[0054] A particularly suitable class of polyols useful in the compositions, foams and methods of the invention are the phthalic anhydride based polyester-ether polyols which are described, for example, in U.S. patent 6,855,844 which is incorporated by reference herein. Suitable commercially available phthalic anhydride based polyester-ether polyols include the "Stepanpols" (Stepan Company).

[0055] In one embodiment, suitable polyols are those having a viscosity at 25 degrees C of from about 500 to 15,000 cP and a hydroxyl number of from about 25 to 400.

[0056] The amount of polyisocyanate material employed in the invention should be sufficient to provide at least about 0.7 NCO group per reactive hydrogen present in the total reaction system. In one embodiment, substantially stochiometric amounts of NCO and OH groups are employed. In another embodiment, a stoichiometric excess of isocyanate compound (3 — 5%) is employed to obtain the flexible foams of the invention. Stoichiometric excess generally means that the ratio of NCO groups of the polyisocyanate component to the OH groups of the polyol component is greater than 1 , specifically from greater than about 1.5 to about 20, more specifically from greater than about 2 to about 10, most specifically from greater than about 2.2 to about 10. In representative embodiments, an NCO/OH molar ratio of about 2.5 to about 6 would be especially suitable to provide compositions that cure at a desirable rate to form foams with excellent pesticide retention characteristics. However, those skilled in the art will appreciate that other levels may be specified within the scope of the invention.

[0057] The use of cross-linking agents in the production of polyurethane foams is well known. Polyfunctional alkanol amines are known to be useful for this purpose. Suitable amines which may be included in the polyol formulation to aid or maintain the miscibility of the polyols include diethanolamine, often abbreviated as DEOA, triethanolamine, often abbreviated as TEOA, and glycerol.

[0058] Apart from water which, as is generally known, liberates CO₂ through reaction with isocyanates, highly volatile organic substances are suitable as inert blowing agents, for example, perhalogenated and partly halogenated hydrocarbons boiling within the temperature range of from -50^° C. to +75^° C, suitably from + 10^° C. to 50^° C, at a pressure of 1013 mbar, such as 1,1-dichloro-l-fluoroethane (R141b), chlorodifluoro-methane (R22), 1-chloro- ljldifluoroethane (R 142b), 1,1,1,2-tetrafluoro-ethane (Rl 34a) and aliphatic or cycloaliphatic C₃ -C₆ hydrocarbons, such as propane, butane, n-pentane, isopentane, cyclopentane and cyclohexane.

[0059] In one embodiment, water is used as the sole blowing agent to produce carbon dioxide by reaction with isocyanate. In this case, water should be used at about 0.1 to about 10 parts per hundred parts of polyol, by weight (pphp), particularly between about 2 and about 8 pphp, more particularly between about 3 and about 6.5 pphp, most particularly between about 3.5 and about 5.8. At foam indexes below 100, the stoichiometric excess of water blows via vaporization and cools the foam, and does not take part of the reaction to produce carbon dioxide.

[0060] While the amount of inert blowing agent may range from about 0 to about 30 pphp, suitable foams can generally be made using between about 0 and about 8 pphp, typically between about 0 and about 5 pphp, more typically between about 1 and about 3 pphp.

[0061] In one embodiment, water is the key foaming agent. This can be introduced into the formulation directly as an added component or it can be added partially or wholly through the addition of the microencapsulated pesticide. Most microencapsulated products will be produced via an aqueous interfacial process, resulting in a dispersion of microcapsules in water. If the concentration of the capsules by such a process is suitable for use in these foam systems, the capsule product may be employed directly. If the amount of water resulting from the addition of such a capsule product is then also correct to produce an optimum foam, no further water need be added. If the water content from such a capsule product would be too high for an effective foam, the water content of the capsule product needs to be reduced. This can be achieved by separation of the capsules from the aqueous phase by some separation technique (e.g. centrifugation) to lower to water content, or the capsule product may be dried by any suitable technique (such as spray drying). Dry product may then be added directly to the foaming components (in either phase) and water and/or other foaming agents added independently. Such methods are well known in the art. For such dry microencapsulated products, there is a need to add appropriate surface agents and/or polymers to both stabilise the microencapsulated product in its dry state and then allow efficient wetting and dispersion of the microcapsules into one or other of the reactive phases that will be mixed together to produce the film.

[0062] Suitable spray-drying adjuvants (also referred to as "suspension adjuvants", "agglomeration adjuvants" and "formulation adjuvants") include water-soluble salts such as ammonium sulfate or sodium, potassium or calcium chlorides. The adjuvants may also include surfactants, water soluble polymers, higher alcohols and other water-soluble or water- dispersible components such as gums, clays and silica's. These chemistries are well known to those skilled in the art but include polymer stabilisers such as polyacrylic acids, polyvinyl alcohols (and their copolymers), polyvinylpyrrolidones (and their copolymers), surface active agents such as ethylene oxide-propylene oxide copolymers, naphthalene sulphonic acid- formaldehyde condensates and alkylbenzene sulphonates. Examples of particular materials include sodium sulfonate of naphthalene formaldehyde condensates such as MORWET^® D425 (available from Witco) and silica filler, such as Hisil ^*' 233 (available from PPG Industries). All possible combinations are thus anticipated and incorporated into this teaching.

[0063] In addition, the compositions of the invention may include an effective amount of a catalyst or reaction accelerator such as tertiary amines, metal-organic compounds, co- curatives, and the like. An effective amount of a catalyst is, for example, from about 0.005 to 2 percent by weight of the reactive polyol and polyisocyanate components. In specific embodiments, the catalyst is present at a level of about 0.01 to about 1.0 percent, based on the total weight of the polyisocyanate material and active hydrogen-containing material employed in the composition. An exact amount can be readily determined by statistical analysis under the reaction conditions, including the actual polyol and polyisocyanate component reactivity, the anticipated reaction conditions, the equipment available, and the like, without undue experimentation.

[0064] Examples of suitable catalysts useful in making polyurethane flexible foams are all those well known to the worker skilled in the art and include tertiary amines such as triethylenediamine (TEDA), N-methylimidazole, 1 ,2-dimethylimidazole, N-methyl moφholine, N-ethyl morpholine, triethylamine, tributylamine, triethanolamine, dimethylethanolamine and bis(dimethylaminoethyl) ether, organometallic tin compounds dibutyl tin dilaurate, dibutylbis(laurylthio)stannate, dibutyltinbis(isooctylmercapto acetate), dibutyltinbis(isooctyl maleate), , and other such tin salts.

[0065] Suitable blow catalysts can be used in their pure form or dissolved in a carrier such as a glycol, such as triethylenediamine in a dipropylene glycol carrier, which is commercially produced under the trade name Dabco^® LV-33 by the Air Products Corporation.

[0066] In one embodiment, the polyurethane foaming compositions will be formulated to produce a flexible foam that is optimized for the environment in which it is to be applied such as suitable open time to allow for uniform application and penetration, proper adhesion of the foam to the target substrate or locus, resistance of the foam to chemical degradation in basic or acidic environments, UV stability, etc., as the case may be. For example, flexible foams that are provided beneath concrete slabs are often exposed to a more alkaline environments than foams that are provided above a slab. In such a case, it is advantageous to select suitable components that react to form a polyurethane foam such as, for example, a sterically hindered polyol (such as a phthalic anhydride based polyester polyol) which can better resist base catalyzed hydrolysis

[0067] Other ingredients or adjuvants may be employed with the foaming composition of the invention to impart to or modify particular characteristics of the composition. The adjuvants should be added only at a level that does not materially adversely interfere with the stability of the microencapsulated pesticide or the adhesion of foams prepared from the composition. The adjuvants may comprise up to 50 weight percent of the (polyol or polyisocyanate)/microencapsulated pesticide composition either individually or in combination. For example, chain-extension agents (e.g., short chain polyols such as ethylene glycol or butanediol); fillers (e.g., carbon black; glass, ceramic, metal or plastic bubbles; metal oxides such as zinc oxide; and minerals such as talc, clays, silica, silicates, and the like), thermoplastic resins; plasticizers; antioxidants; pigments; U.V. absorbers; cell stabilizers such as silicones and adhesion promoters such as silanes, and the like may be included to modify set time, open time, green strength build-up, tack, flexibility, adhesion, ductility, adhesive strength, gloss; elongation, pliability, buckling strength, crease resistance; as well as increased resistance to solvents, acids, bases, light, heat, cold, and sudden temperature changes, etc. Such materials are well known in the art. [0068] In one embodiment, to make the polyurethane foams of the present invention acceptable from a regulatory standpoint, for example, to be used in conjunction with building materials, flame retardants can be incorporated. Useful flame retardants include, without limitation, any compound with flame suppression properties that can be dissolved or dispersed in the polyurethane foam. These include compounds such as chlorinated or brominated phosphates, phosphonates, inorganic oxides and chlorides. Suitably, the flame retardant is a soluble liquid such as triethyl phosphonate, pentabromodiphenyl oxide, and in particular is tri(l-methyl-2-chloroethyl) phosphate. When present, the flame retardants are employed in an amount of from 5 to 15 parts by weight.

[0069] The composition mixture may be formulated such that the polyurethane foam may be made to cure to any useful color or shade as would be readily apparent to one skilled in the field of polyurethane foams. For example, to create foams with color, colorants may be used.

[0070] Selection of particular reactive components, optional adjuvants and microencapsulated pesticides to include in the inventive flexible foaming polyurethane composition and method can be determined readily by one of skill in the art and without undue experimentation for a particular target substrate or locus and set of pest pressure conditions.

[0071] In one embodiment, the ratio of polyurethane to pesticidal product in the cured foam at the time that a foam of the composition is formed is at least 70:30 polymer: pesticide product, particularly 80:20 polymeπpesticide product and more particularly 85:15 polymer: pesticide product.

[0072] As noted above, a filler such as fiber may be added to improve cohesion and flow characteristics of the foaming composition. Among the suitable fibers there may be mentioned glass fibers. The fibers help to prevent the liquid surface uncured foam from sagging on pitched or vertical surfaces of target substrates during cure and to improve robustness and structural integrity of the cured foam. Other solid fillers such as clay, calcium carbonate, and titanium dioxide are also contemplated.

[0073] In addition to the viscosity constraints noted above, polyols and polyisocyanates that can be used are those that are capable of forming a substantially water-impermeable polyurethane flexible foam upon curing. [0074] When it is said that the flexible foam is substantially water-impermeable, it is best tested by an appropriate water resistance test (for example, ASTM Method D 870-2). Among the advantages that a foam having low water permeability provides is that the loss of the pesticide due to water solubilization dispersion in the environment is reduced. It is also advantageous if the resultant polyurethane is one that is compatible with the polymer in the wall of the microcapsule employed in the composition.

[0075] In one embodiment, polyurethane flexible foams having a thickness of from 0.1 to 10 mm are formed on a target substrate. For some target substrates, e.g. around bath traps, wall voids and the like, the foam thickness can be greater, indeed it can be employed to fill substantially completely the void space. Those skilled in the art will adapt the foam thickness as appropriate under the prevailing circumstances.

[0076] In one embodiment, the polyurethane flexible of the invention may be provided with a protective overcoat such as a latex or a polyurethane composition without a microencapsulated pesticide.

[0077] Latexes suitable as overcoats of the cured polyurethane foams are derived from a wide variety of polymers and co-polymers and combinations thereof. Suitable latexes for use as overcoats comprise polymers and copolymers of styrene, alkyl styrenes, isoprene, butadiene, acrylonitrile lower alkyl acrylates, vinyl chloride, vinylidene chloride, vinyl esters of lower carboxylic acids and alpha, beta-ethylenically unsaturated carboxylic acids, including polymers containing three or more different monomer species copolymerized therein, as well as post-dispersed suspensions of silicones or polyurethanes.

[0078] If it is desirable, the latex overcoats can be compounded with, or have mixed therein, other known ingredients such as plasticizers, emulsifϊers, stabilizers, curing agents, fillers, antioxidants, antiflexible foaming agents, dying adjuvants, levelling agents, pigments, or other compounding aids. Furthermore, thickeners or bodying agents may be added to the polymer latexes so as to control the viscosity of the latexes and thereby achieve the proper flow properties for the particular application desired. Such materials are well known in the art.

[0079] The non-curable ingredients of the foaming composition and cured flexible foam herein further comprise at least one pesticide product comprising at least one microencapsulated pesticide and, optionally, one or more non-microencapsulated pesticides. The microencapsulated pesticide portion of the pesticide product is present in an amount of at least 1% by weight of the cured foam. The amount of any non-mi croencapsulated pesticides that are present in the composition are utilized in an amount of from 0 to about 99% by weight of the entire pesticide product present in the cured foam.

[0080] In one embodiment, the pesticide products in the foaming composition and cured polyurethane foam including insecticides, acaricides and fungicides are employed in pesticidally effective amounts which will correspond to rates dependent on their activity levels for the desired end use. For example, in one embodiment, suitable rates for the pesticide products are the existing rates given on the current product labels for such pesticide products.

[0081] Microencapsulated pesticide active ingredients suitable for use in the foaming compositions and cured flexible foams according to the invention are prepared with any suitable technique known in the art. For example, various processes for microencapsulating material have been previously developed. These processes can be divided into three categories-physical methods, phase separation and interfacial reaction. In the physical methods category, microcapsule wall material and core particles are physically brought together and the wall material flows around the core particle to form the microcapsule. In the phase separation category, microcapsules are formed by emulsifying or dispersing the core material in an immiscible continuous phase in which the wall material is dissolved and caused to physically separate from the continuous phase, such as by coacervation, and deposit around the core particles. In the interfacial reaction category, microcapsules are formed by emulsifying or dispersing the core material in an immiscible continuous phase and then an interfacial polymerization reaction is caused to take place at the surface of the core particles. The concentration of the pesticidal active ingredient present in the microcapsules can vary from 0.1 to 60% by weight of the microcapsule. These techniques are well known in the art.

[0082] Suitable microcapsules for use in the foamable compositions and polyurethane foams of the invention include microcapsules of both the relatively thin-walled quick-release type and the relatively thicker-walled controlled-release type or combinations thereof.

[0083] In one aspect, suitable microcapsule wall materials are selected from the polyureas, aminoplasts, polyurethanes and polyamides and mixtures thereof [0084] In one embodiment, polyurea microcapsules containing a suitable termiticide are prepared bas exemplified in U.S. Pat. No. 4,285,720, which involves the use of at least one polyisocyanate such as polymethylene polyphenylisocyanate (PMPPI) and/or tolylene diisocyanate (TDI) as the prepolymer. In the creation of polyurea microcapsules, the wall- forming reaction is initiated by heating the emulsion to an elevated temperature at which point the isocyanate polymers are hydrolyzed at the interface to form amines, which in turn react with unhydrolyzed polymers to form the polyurea microcapsule wall. Other suitable procedures for making microcapsules are described, for example, in Shirley et al., "Delivery of biological performance via micro-encapsulation formulation chemistry", Pest Management Science, Volume 57, Issue 2, Pages 129-132 (February 2001) and the references cited therein.

[0085] As noted above, many microencapsulated pesticides suitable for use in the invention will be produced via an aqueous interfacial process, resulting in a dispersion of microcapsules in water. If desired, the water may be decreased or removed from such systems. Processes for production of relatively dry water-dispersible compositions of microencapsulated pesticides are described, for example, in U.S. Pat. Nos. 5,354,742 and 6,555,122 which are incorporated by reference herein. The spray drying of the microcapsule is carried out under typical spray-drying conditions and with the use of typical spray-drying equipment in which the inlet temperatures generally range from about 105 to about 200^° C. and output temperatures range from about 45 to about 95^° C.

[0086] It may also be advantageous to add to the microcapsule suspension prior to conducting the spray drying, typical spray drying adjuvants or additives such as clays, gums, surfactants, etc. as these may in general improve the spray drying procedure and the product quality obtained therefrom.

[0087] Examples of suitable insecticidal, termiticidal or acaricidal active ingredients for use in the polyurethane foaming compositions and cured flexible foams include, but are not limited to, pyrethrins and synthetic pyrethroids; azoles, bisamides, oxadizine derivatives; chloronicotinyls; nitroguanidine derivatives; triazoles; organophosphates; pyrrols; pyrazoles; phenyl pyrazoles; diacylhydrazines; biological/fermentation products; carbamates and combinations of these types of compounds.

[0088] In one aspect, suitable insecticides, termiticides or acaricides for use in the inventive polyurethane foaming compositions and flexible foams include tefluthrin, permethrin, the cyhalothrins including lambda cyhalothrin and gamma cyhalothrin, resmethrin, deltamethrin, cypermethrin, cyphenothrin, cyfluthrin, deltamethrin, chloφyrifos, fenoxycarb, diazinon, dichlorophen, methyl isothiocyanate, pentachlorophenol, tralomethrin, 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. One specific class of pesticides for use in the microcapsules are the class of cyhalothrins including lambda cyhalothrin and gamma cyhalothrin. As noted above, in one embodiment, suitable rates for the insecticide are the existing rates given on the current product labels for pesticide products containing such pesticide.

[0089] Examples of suitable fungicides for use in the polyurethane foaming composition and flexible foams include, but are not limited to, the azoles such as cyproconazole, propiconazole, tebuconazole and difenoconazole; the strobilurins such as azoxystrobin, dimoxystrobin, fluoxastrobin, kresoxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyraclostrobin and trifloxystrobin; chlorothalonil; and thiabendazole. As noted above, in one embodiment, suitable rates for the fungicide are the existing rates given on the current product labels for pesticide products containing such fungicide.

[0090] In one embodiment, microencapsulated insecticides (optionally including at least one non-microencapsulated pesticide such as an insecticide or fungicide) are present in the foaming composition in an amount to provide an effective barrier to insect pests such as arthropods which contact or come into the vicinity of flexible foams prepared from the compositions. As one skilled in the art can appreciate the exact amount will vary depending upon factors including the type of microcapsule employed, the substrate or locus to be treated as well as the thickness and orientation (horizontal or vertical) of the foam. The insecticide of the foam must not prematurely dissipate and should be efficacious during that time in the target insects' life cycle which may cause potential damage to wood portions of a building or other construction. One skilled in the art will appreciate that this time will vary depending on the target insect among other factors. In general the foam will be efficacious for at least one year for a surface treatment and at least 5 years for an under slab (concrete) treatment after curing. The barrier foam of the present invention will contain an amount of insecticide that is insecticidally effective. An insecticidally effective amount a used herein means that amount of insecticide that will kill insect pests or will consistently reduce or retard the amount of damage produced by insect pests.

[0091] In one aspect, target pests include insects and representatives of the order acarina such as termites, ants (such as carpenter ants) and spiders. More specifically, termites that may be controlled by the composition and method of the invention include, for example, Reticulitermes spp. such as R.βavipes, R. hesperus, R. tibialis, R. virginicus, K ^' .santonensis and R. hageni and Coptotermes spp. such as C. formosanus.

[0092] The application methods, such as spraying, misting, atomising, broadcasting, brushing, caulking, spreading, dipping or pouring, and the nature of the composition are adapted to suit the intended aims and the prevailing circumstances. Optimum rates of application of the inventive composition, for a particular target substrate or locus and set of insect pressure conditions, can be determined easily and without undue experimentation by simple ranging studies carried out in wood such as in wooden building construction and wood which is in contact with soil for example fence posts, utility poles, railroad cross-ties and wooden supports, that can be structurally degraded by the action of one or more fungal or wood pests including, but not limited to, wood destructive fungi, termites, ants and other boring insects or arthropods.

[0093] In one embodiment, the compositions of the invention are applied to substrates or loci such as clean, dry surfaces, typically concrete and cement including in and around concrete slab joints such as construction joints, key joints, tool joints and saw joints. Other suitable targets include substrates such as plastic surfaces and substrates such as a DPM (Damp-proof membrane), vapor or moisture barriers or retarders and loci in or around structures, such as, homes, buildings, utility penetrations, bath traps, wall voids, wooden structures and other construction materials or construction substrates. In this way, remote protection of a substrate or target (e.g. a house or other wood containing structure) is achieved by preventing or reducing termite access by treatment of a remote point or locus (e.g. a crack in a floor or slab), etc. with the inventive composition. DPM 's can be a simple polyethylene membrane, a chemically etched polyethylene (such as Corona treated polyethylene for greater wetting, substantivity of the polymer film to the polyethylene sheet) or re-enforced, structured multilayer polyethylene sheets such as the product range sold under the Tradename GRIFFOLYN® sold by Reef Industries, Inc. (Houston, TX).

[0094] The foaming compositions can also be applied to self-amalgamating tapes and films such as those composed of bitumous materials, butyl rubber, polyisobutene and the like, such as those sold under the Tradename Jiffy Seal® either prior to or after application of such self- amagamating materials to a target substrate such as a construction substrate, material or utility penetration such as a PVC or copper pipe or the like. [0095] After the foaming composition has been applied to the target substrate or locus, it is cured to form the polyurethane flexible foam. When it is said that the foam is "cured", or when "curing" the foam is referred to, what is meant is that a solid foam of components is formed from the polyol(s) and polyisocyanate(s) in the composition. Curing is often the result of a chemical reaction, adsorption, sequestration, or other forms of polymer curing that are known in the art.

[0096] The polyurethane foaming composition when applied onto substrates or in loci exhibits resistance to pests including termites such that if termites do attempt to feed or tunnel through the flexible foam, they find it not palatable or it causes mortality. The main component used in the foaming composition that either causes mortality or makes it not palatable is a microencapsulated pesticide. However, it is believed that the cured physical polyurethane foam also contributes synergistically to this protection against insects such as arthropods including termites and wood-boring ants by inhibition of feeding.

[0097] The following examples describe specific embodiments within the scope of the invention. Other embodiments within the scope of the claims herein will be apparent to one skilled in the art from consideration of the specification or practice of the invention as disclosed herein. It is intended that the specification, together with the examples, be considered exemplary only, with the scope and spirit of the invention being indicated by the claims which follow the examples. In the examples all percentages are given on a parts by weight (PBW) basis unless otherwise indicated.

[0098] List of chemistries employed in the examples.

EXAMPLES

[0099] EXAMPLE 1 — Polyisocyanate/Microencapsulated Pesticide Stock Solution

[00100] About 218g of Demand CS (microencapsulated lambda cyhalothrin,

Syngenta Crop Protection, Inc., Greensboro, NC) is added to 218g of a surfactant solution prepared from 30Og of water, 6.Og of Morwet^® D425 (sodium sulfonate of naphthalene formaldehyde condensate/ Witco) and 0.7g of HiSiI 233 (silica filler/ PPG). The components are thoroughly mixed until a stable mixture is formed. [00101] Sprayed-dried Demand CS is obtained by pumping the mixture at 21-22 ml/min into a spray drier having an inlet temperature of 105° C and an outlet temperature of 74-75° C.

[00102] 1300 g of No. 233 Isocyanate (liquid polymeric MDI prepolymer, BASF

Corporation, Wyandotte, Mich.) and 26.6 g of the spray dried Demand CS were mixed together for use in the examples which follow.

[00103] EXAMPLE 2 -Low Rise High Resilience Urethane Foam

Polvol Premix

Mateπal PBW

Pluracol 2100 (Graft Polyether) 41.9

Pluracol 2130 (Polyether) 53.3

Water 2.3

DEOA (Cross-linking agent) 0.3

33LV (amine blow catalyst) 0.2

T- 12 (Dibutyltin dilaurate) 0.02

Total 98.02

[00104] The polyol premix was blended vigorously. 10Og of the polyol premix was combined with 48.62g of the isocyanate stock solution of example 1. The material was then stirred very vigorously for 7 seconds and quickly spread either:

1. onto a sheet of corona-treated polyethylene. Once the foam is dry, the foam is cut into several pieces for testing with a concrete composition by pouring a wet concrete on to the top of the polyurethane foam covered polyethylene sheets and allowed to dry; or

2. onto the top of a dry block of dry concrete.

[00105] EXAMPLE 3 -Urethane Foam

Polyol Premix

Material PBW

Voranol 3512A (EOPO polyether polyol) 33.3

Voranol 230-112 (EOPO polyether polyol) 33.3

Voranol 4701 (Polymer) 33.3

Water 2.3

DEOA 0.2

33LV 0.1

T-12 0.01

Total 102.51 [00106] 100 g of the polyol premix was combined with 58.1 Ig of the isocyanate stock solution of example 1 and spread above and below concrete as specified in example 2.

[00107] EXAMPLE 4 -Urethane Foam

Polyol Premix

Mateπal PBW

Voranol 3512A (EOPO polyether polyol) 25

Voranol 230-112 (EOPO polyether polyol) 25

Voranol 4701 (Polymer) 50

Water 2, .3

DEOA 0. .2

33LV 0.1

T-12 0 .01

Total 102 :.6i

[00108] 100 g of the polyol premix was combined with 55.88g of the isocyanate stock solution of example 1 and spread above and below concrete as specified in example 2.

[00109] EXAMPLE 5 -Urethane Foam

Polyol Premix

Material PBW

Voranol 3512A (EOPO polyether polyol) 20

Voranol 230-112 (EOPO polyether polyol) 20

Voranol 4701 (Polymer) 60

Water 2.3

DEOA 0.2

33LV 0.1

T-12 0.01

Total 102.61

[00110] 100 g of the polyol premix was combined with 54.6Og of the isocyanate stock solution of example 1 and spread above and below concrete as specified in example 2. [0011 1 ] EXAMPLE 6 -Urethane Foam

Polyol Premix

Material PBW

Voranol 3512A (EOPO polyether polyol) 33

Voranol 230-112 (EOPO polyether polyol) 33

Priplast 3191 33

Water 0.8

DEOA 0.2

33LV 0.1

T-12 0.01

Total 100.11

[00112] 100 g of the polyol premix was combined with 61.84g of the isocyanate stock solution of example 1 and spread above and below concrete as specified in example 2.

[001 13] EXAMPLE 7 -Urethane Foam

Polyol Premix

Material PBW

Voranol 3512A (EOPO polyether polyol) 33

Voranol 230-112 (EOPO polyether polyol) 33

Priplast 3196 33

Water 0.8

DEOA 0.2

33LV 0.1

T-12 0.01

Total 100.11

[00114] 100 g of the polyol premix was combined with 58.68g of the isocyanate stock solution of example 1 and spread above and below concrete as specified in example 2.

[001 15] EXAMPLE 8 -Urethane Foam

[00116] 80 parts of TC-276A from BJB Enterprises was mixed with 100 parts of TC-

276B and 0.77% total weight of dry Demand capsules. The material was stirred vigorously and quickly poured into empty cups or onto dry cement.

[00117] TC-276A is an aromatic diisocyante and related oligomers based on 4,4 - phenylmethane diisocyanate (MDI). TC-276B is a polyol resin based on propylene oxide, ethylene oxide based polyglycols. [00118] EXAMPLE 9

Lambda-cyhalothrin 15.0% Amino last ca sules

[00119] The components of each phase were blended until homogenous. The oil phase was sheared into the aqueous phase until the particle size was reduced to a median diameter of 11.3 microns. The pH was then adjusted with sulfuric acid to 1.9 and the temperature was increased to 55°C for 3 hours. After cooling to room temp the pH was adusted to 5.5 with sodium hydroxide. A portion of these capsules were spray dried with a polyvinyl alcohol (PVA) solution (Gohsenol GL05):

[00120] This slurry was spray dried with an inlet tempearture of 170⁰C and an outlet temperature of 66°C to yield a solid product containing 22.5% Lambda-cyhalothrin.

[00121] A portion of these granules were formulated into a polyurethane foam and illustrates the use of a system with more than two feedstock streams in the foam preparation:

[00122] The Lambda-cyhalothrin granules were dispersed in the PPG425. This was the first feedstock stream. The Stepanpol, diethanolamine, Dabco 33LV and Dibutyltin dilaurate were blended together as the second feedstock stream and then the appropriate net weight of this mixture was added to the first feedstock stream (PPG425 / lambda-cyhalothrin base). To this mixture, the third feestock stream (Rubinate M) was addedand vigorously stirred in for 20 seconds. The mixture was divided into 4 smaller portions, each one of which rose and set to form a non-tacky, flexible foam.

[00123] The foams of examples 2 - 8 are tested for pesticide retention in accordance with the following procedure:

[00124] A sample of about 1 gram of each foam prepared and in accordance with examples 2 - 8 each containing a given % by weight of microencapsulated pesticide is transferred to a 2 oz bottle. 20 ml of tetrahydrofuran (THF) solvent is added to the bottle and sonicated in a water bath for about 30 minutes. Each sample is filtered through a 0.45 micron filter and analyzed for lambda cyhalothrin by HPLC. The percentage of lambda cyhalothrin remaining in the each sample one month after treatment is calculated. The results are reported in the table below.

TABLE 1 - Pesticide Retention 1 month after treatment

[00125] Storage was continued for longer periods of time. Ambient temperature recovery was very high. Acceptable results were seen after 6 months storage at 38C as indicated in the attached data set. Temp C 38

Above Below

Ex. 2 100 90

Ex. 3 87 87

Ex.4 83 83

Ex. 5 83 83

Ex. 6 80 80

Ex. 7 80 80

[00126] In summary, it is seen that this invention provides a new curable polyurethane composition containing a microencapsulated pesticide, flexible foam barriers prepared therefrom, and methods of making the same. Variations may be made in proportions, procedures and materials without departing from the scope of the invention as defined by the following claims.

Claims

WHAT IS CLAIMED IS:

1. An ambient curable polyurethane foaming composition comprising a mixture of one or more components that react to form a polyurethane flexible foam and at least one microencapsulated pesticide, wherein a foam prepared from the composition has a percent recovery of at least 50%.

2. A curable, two (or more) -part flexible foaming polyurethane composition adapted to cure under ambient conditions comprising a mixture of (A) at least one polyisocyanate, (B) at least one polyol, (C) at least one blowing agent and (D) at least one microencapsulated pesticide, wherein a foam prepared from the composition has a percent recovery of at least 50%..

3. A high-solids, flexible polyurethane foaming pesticidal composition for treating a locus or substrate comprising a reactive mixture of: (A) at least one polyol, (B) at least one polyisocyanate, (C) at least one blowing agent and (D) a pesticidally effective amount of at least one microencapsulated pesticide, which composition is curable under ambient conditions, wherein a foam prepared from the composition has a percent recovery of at least 50%, and wherein the microencapsulated pesticide within flexible foams prepared therefrom is effective to reduce or prevent pest attack or pest infiltration of the treated locus or substrate.

4. The composition according to claims 2 or 3, wherein the polyisocyanate comprises a polymeric diphenylmethane diisocyanate.

5. The composition according to claims 2 or 3, wherein the polyol comprises a polyether polyol..

6. The composition according to claim 5, wherein the polyether polyol is selected from polyalkylene ether and polyester polyols.

7. The composition according to claims 1 , 2 or 3, wherein the microencapsulated pesticide is an insecticide.

8. The composition according to claim 6, wherein the microencapsulated pesticide is lambda cyhalothrin.

9. The composition according to claims 1, 2 or 3, wherein the microencapsulated insecticide is a termiticide.

10. The composition according to claims 1, 2 or 3, wherein the microencapsulated pesticide is a fungicide.

1 1. The composition according to claims 1 , 2 or 3, which further comprises at least one non-microencapsulated pesticide.

12. The composition according to claims 1, 2 or 3, wherein the microcapsule wall comprises a polyurea.

13. The composition according to claims 1, 2 or 3, wherein the microcapsule wall comprises an aminoplast.

14. The composition according to claims 1, 2 or 3, wherein the microcapsule wall comprises a polyurethane.

15. The composition according to claims 1, 2 or 3, wherein the microcapsule wall comprises a polyamide.

16. A polyurethane flexible foam prepared from the composition according to claims 1, 2, or 3.

17. The composition according to claims 1, 2, or 3, wherein the polyurethane foaming composition is a three or more part composition comprising a microencapsulated pesticide dispersed in an oligomer of a lower alkylene glycol.

18. The composition according to claim 17, wherein the lower alkylene glycol oligomer is selected from oligomers of ethylene, propylene and butylene glycol.

19. The composition of claim 18, wherein the lower alkylene glycol oligomer is selected from polyethylene glycol 400 and polypropylene glycol 425

20. A flexible polyurethane foam having a percent recovery of at least 50% comprising a microencapsulated pesticide.

21. A composition which is substantially free of isocyanate functional compounds comprising a mixture of at least one polyol and at least one microencapsulated pesticide, which composition is curable under ambient conditions when combined with a curing effective amount of at least one polyisocyanate.

22. A composition which is substantially free of active-hydrogen containing compounds comprising a mixture of at least one polyisocyanate and at least one microencapsulated pesticide, which composition is curable under ambient conditions when combined with a curing effective amount of at least one polyol.

23. The composition according to claims 17 or 18, wherein the microencapsulated pesticide comprises lambda cyhalothrin.

24. The composition according to claim 17, wherein the polyisocyanate comprises a polymeric diphenylmethane diisocyanate.

25. The composition according to claim 18, wherein the polyol comprises a polyether polyol.

26. The composition according to claim 22, wherein the polyether polyol is selected from polyalkylene ether and polyester polyols

27. A method of protecting building construction material with a foaming composition of claims 1, 2 or 3, comprising applying said composition onto at least one surface of the construction material.

28. A method for reducing or preventing pest attack or pest infiltration of substrates or loci that are susceptible or vulnerable to such attack or infiltration, which method comprises:

(I) providing a curable, flexible polyurethane foaming reaction mixture of at least one microencapsulated pesticide and one or more components that react to form a polyurethane; (II) applying said mixture to said pest susceptible substrate or locus; and

(III) curing the mixture under ambient conditions to form a flexible polyurethane foam on the substrate or in the locus.

29. A method according to claim 23, wherein said reaction mixture is provided as a two part system.

30. A method according to claim 23, wherein the substrate comprises a polymer sheet selected from a vapor barrier and a damp proof membrane.

31. A method according to claim 23, wherein the substrate or locus is a building construction material.

32. The method of claim 26, wherein the construction material is selected from wood, wood composites, gypsum wall board, cellulosic insulation, cement or cement composites, concrete blocks, concrete slabs, ceiling tiles, utility penetrations or other synthetic materials.

33. The method of claim 27, wherein the utility penetration is a PVC or copper pipe.

34. The method of claim 26, wherein the construction materials comprise a damp-proof membrane or a vapor-barrier.

35. The method of claim 28, wherein the damp-proof membrane or vapor barrier is corona treated prior to application of the composition.

36. The method of claim 26, wherein the construction material comprises a self- amalgamating tape or film.

37. The method of claim 31, wherein the self-amalgamating tape or film comprises a material selected from bitumous materials, butyl rubber and polyisobutene.

38. A barrier against pest invasion prepared in accordance with the methods of claims 22 or 23.

39. A packaged at least two-part polyurethane coating system, which comprises in combination in one or more containers: (a) a first part comprising at least one polyisocyanate; (b) a second part comprising at least one polyol; and (c) at least one microencapsulated pesticide.

40. The package of claim 34, wherein the microencapsulated pesticide is present in the first part.

41. The package of claim 34, wherein the microencapsulated pesticide is present in the second part.

42. The package of claim 34, which further comprises a third part containing a microencapsulated pesticide.

43. The package of claim 34, wherein the microencapsulated pesticide is lambda cyhalothrin.

44. The package of claim 34, wherein the polyisocyanate comprises a polymeric diphenylmethane diisocyanate.

45. The package of claim 34, wherein the polyol comprises a polyether polyol.

46. The package of claim 45, wherein the polyether polyol is selected from polyalkylene ether and polyester polyols.

47. The package of claim 42, wherein the microencapsulated pesticide dispersed in an oligomer of a lower alkylene glycol.

48. The package of claim 47, wherein the lower alkylene glycol oligomer is selected from oligomers of ethylene, propylene and butylene glycol.

49. The package of claim 48, wherein the lower alkylene glycol oligomer is selected from polyethylene glycol 400 and polypropylene glycol 425.