Termite-preventing agent using tungsten compound

Abstract

To solve a problem that, because a general tungsten oxide has a large particle size and is not impregnated into an adherend, detachment thereof from the adherend occurs during long-period outdoor and indoor storage, and a termite-preventing effect is lost by secular change, and to solve a problem that the termite-preventing effect of an organic-based agent does not persist for a long period because the organic compound evaporates and is eluted into water.SOLUTION: By bringing a tungsten compound into nanoparticles of a size of 50 nm or less, it becomes easily impregnated from the surface into the deep part of a cellulose-based material such as wood, and the tungsten compound having a high termite-preventing effect becomes hard to be eluted from the surface of an adherend to outside. As a result of this, the termite-preventing effect persists for a long period.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present invention relates to a termite control agent which uses a tungsten compound. [Background technology]

[0002] Generally, termite control agents have either a repellent or an anti-termite effect. Termites attack wood and cause great damage to buildings as well as to structures made of wood. There are the following methods to prevent damage caused by termites. A method of directly spraying chemicals to kill termites. A method of using bait to make termites eat an anti-termite chemical, and then killing the termites in the nest by feeding them with an anti-termite chemical or by grooming. A method of using volatile chemicals to have a repellent or anti-termite effect on termites. A method of using physical barriers and obstacles to prevent termite invasion. Each of these has a single effect, and the method has been chosen depending on the situation, and a single effect or a combination of multiple effects has been used.

[0003] Pyrethroids are the most common organic materials used as regular insecticides. They are compounds made to resemble pyrethrin, a natural insecticidal component found in pyrethrum flowers. They are characterized by their ability to paralyze the nerves of insects. Examples include pyrethrin, allethrin, imiprothrin, empenthrin, cyphenothrin, cyfluthrin, transfluthrin, bifenthrin, fenothrin, phthalthrin, furamethrin, prallethrin, profluthrin, permethrin, metofluthrin, resmethrin, momfluorothrin, and etofenprox. Organophosphate insecticides, which are active ingredients that work by inhibiting the function of insect nerves, include dichlorvos, fenitrothion, fenthion, trichlorfon, propetamphos, diazinon, and pyridaphenthion. An organosilicon insecticide is silafluofen. An amidinohydrazone insecticide is hydramethylnon. Phenylpyrazole insecticides include fipronil, and carbamate insecticides include fenobucarb, propoxur, and carbaryl.

[0004] Other examples of boric acid-based insecticides include boric acid balls. Methoxadiazone is an example of an oxadiazole-based insecticide. Methoprene, pyriproxyfen, and diflubenzuron are active ingredients that inhibit insect molting or metamorphosis and prevent the emergence of adult insects.

[0005] Recently, neonicotinoid insecticides have been developed that are effective against pests that are resistant to pyrethroid, organophosphate, and carbamate insecticides. These include imidacloprid, clothianidin, acetamiprid, and thiamethoxam. Among these, thiamethoxam has a long-lasting insecticidal effect against termites. Neonicotinoid insecticides act on the nerves of insects and are used to exterminate pests that are resistant to pyrethroid insecticides. The main pests that are used include nuisance pests such as millipedes, ants, pillbugs, woodlice, earwigs, centipedes, and leeches. However, neonicotinoids are highly likely to be the cause of colony collapse disorder, which causes large numbers of honeybees to die, and are subject to regulation in the EU and other countries.

[0006] Well-known repellents include fragrances with insect repellent properties and the pyrethroid insecticide "empenthrin," which is used to repel pests from clothing. It has been reported that there are no problems with applying this directly to the skin. Specifically, DEET and icaridin are known to be effective.

[0007] Organic compound insecticides and repellents have been developed using various mechanisms of effectiveness depending on the type of insect. However, because they are basically organic materials, they evaporate and decrease in quantity, and also deteriorate by reacting with oxygen in the air, so the fatal flaw is that they are not effective over the long term.

[0008] On the other hand, Patent Document 1 and Non-Patent Document 1 state that tungsten compounds and molybdenum compounds have high insecticidal effects among inorganic compounds. Among these, molybdenum compounds have been avoided because the molybdenum element is a carcinogenic substance. However, both tungsten compounds and molybdenum compounds have been expected to have long-lasting effects.

[0009] In particular, tungsten and compounds containing tungsten are known to have the effect of inhibiting nitrogen fixation by fungi that help digest wood in insects such as termites, leading to their death and suppressing their proliferation, as described in Patent Document 1. Tungsten has a selective inhibitory effect only on certain animals and is highly safe. Tungsten is inexpensive and easy to obtain. For this reason, it was expected to be a promising termite control agent. However, in previous reports, the particle size of these compounds was large, and they had poor weather resistance and could be washed away by rain, etc. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent Publication No. 59-082309 [Non-patent literature]

[0011] Reference 1 Journal of the Japanese Society of Environmental Entomology and Zoology · Application of molybdenum and tungsten compounds to termite control. Kai Yoshimura, Junro Katsuta, Koichi Nishimoto (1989) Summary of the Invention [Problem to be solved by the invention]

[0012] Conventional termite control agents are organic, specifically pyrethroids, organophosphate insecticides, carbamate insecticides, etc., which have been used as repellents or insecticides. These organic compound-based control agents are volatile substances that disperse and disappear in the air, dissolve when they come into contact with water, and are oxidized and decomposed when they come into contact with oxygen in the air, resulting in problems with not being able to achieve long-term effectiveness. In addition, there has been a problem of some organic compounds dissolving into water and polluting rivers and groundwater. [Means for solving the problem]

[0013] In the present invention, the tungsten compound is made into nanoparticles as an inorganic compound material that does not evaporate, allowing it to easily penetrate from the surface to the depths of porous materials such as wood, and the tungsten compound, which has a high termite control effect, is not eluted from the surface of the adherend to the outside, so long-term durability is maintained.

[0014] This invention is a new invention that utilizes the termite control function of this tungsten compound. The control effect is either a repellent effect that keeps termites away or an insecticidal effect. Conventional pest control agents use chemicals that have a repellent effect attached to wood and then sprayed around the wood to control the volatilized substances. Volatile substances (pyrethroids, etc.) diffuse into the air and decompose, so the effect does not last for a long period of time.

[0015] In the investigation of the termite repellent effect using various materials, it was found that ammonium tungstate compounds have a very strong termite repellent effect. Furthermore, ammonium tungstate compounds are not vaporizable materials but are long-term stable materials, so they have the performance of being less prone to deterioration over time. The particles of the ammonium tungstate compounds of the present invention should preferably be small in size, and may be in a crystalline or amorphous state. As for the form, they have sufficient effect even when dissolved in a solvent and sprayed. The ammonium tungstate compounds are composed of at least W, O, N, and H, but similar effects can be obtained by adding other elements. Other elements such as Pt, Ru, Ag, Pd, Cu, Ni, and Sn may also be added. Ammonium tungstate compounds have various compositions and crystal structures, and the termite repellent effect does not depend on these compositions and crystal structures, so the repellent effect is similarly high.

[0016] As an example of the tungsten compound of the present invention, typically ammonium tungstate salt, M p (NH3) n-P ·Cl q mWO3 rH2O, M p (NH4) 2x-p Clq (WO4) x zH2O or M p (NH4) 2x ·Cl q (WO4) x (WO3) y zH2O(n>0,n>P≧0,m>0,r≧0,q≧0,x>0,y≧0,Z≧0,M:Li,Na,K,Cs,H,Ca,Mg), M as tungstate 1-T Examples of tungsten compounds include those containing at least one of the following: WO3·zH2O (M: Na, Li, K, Cs, H, Ca, Mg, 1≧T≧0, Z≧0).

[0017] Other elements such as Mo, La, Nd, Cr, As, Cd, Ta, Sr, Ca, Mg, Al, Si, Sn, Cu, and Fe may be present on the tungsten site.

[0018] If the size of these compounds is 1 um or more, they will not penetrate the nanoporous parts that are characteristic of structures, parts, and construction materials made of cellulose-based elements, so a size of 500 nm or less is best for these materials, and preferably 50 nm or less. It has been confirmed that smaller sizes allow them to penetrate easily from the surface to the center of structures, parts, and construction materials made of cellulose-based materials, and are resistant to weathering and aging.

[0019] As a result, it is desirable for the slurry of the present invention to be one in which the size distribution of this compound is such that, within the overall particle size distribution, the amount of powder with a size of 50 nm or less is at least 0.1% by weight, and preferably 5% by weight, of the total.

[0020] In order to effectively control termites, it has been experimentally confirmed that the use of powders with a size of 50 nm or less on cellulose-based wood materials, structures, parts, construction materials, and string-like objects is extremely effective.

[0021] In the slurry composition of the present invention, the solvent may be a polar or non-polar solvent, and is not limited to the type of solvent. In addition, the vapor pressure of the solvent is not limited, but by using an organic solvent with a low vapor pressure, it is easy to obtain a long-term repellent effect, and by adding an additive that acts as an adhesive or binder to the solvent and hardening it during the drying process, it is possible to deal with long-term changes over time. In the case of only the insecticidal effect, it is sufficient to simply permeate a liquid dispersed in water, ethanol, isopropanol, etc. from the surface to the center of a structure, part, or construction material made of a cellulose-based material and dry it.

[0022] In the method of vaporizing the solvent to leave the control agent, specific examples of the solvent include low-boiling point solvents such as water, ethanol, propanol, isopropanol, butanol, acetophenone, cyclohexanol, hebutane, octane, and cyclohexane. Conversely, when used to keep the control agent in the solvent for a long period of time, specific examples of organic solvents with low vapor pressure include ethylene glycol, diethylene glycol, ethyl acetate, propylene glycol, stearic acid, and oleic acid. Examples of binders for fixing the control agent in the adherend with an adhesive include urea-based, melamine-based, phenol-based, epoxy-based, acrylic-based, polyester-based, urethane-based, nitrile rubber-based, styrene butadiene rubber-based, butyl rubber-based, silicone rubber-based, acrylic rubber-based, and urethane rubber-based. In this case, the solvent is not particularly limited to polar or non-polar solvents.

[0023] Regarding the method of treating the tungsten compound of the present invention so as to obtain a control effect when it penetrates into a material of a cellulose-based compound, if it contains at least 0.01% by weight relative to the weight of the material, the control effect can be obtained. In this case, if the tungsten compound is contained in a thickness of at least 10 um or more from the surface to which the tungsten compound is applied to a structure, part, construction material, or furniture, the control effect can be obtained. In order to enhance the control effect, it is preferable that the compound contains 0.1% by weight. Furthermore, as the content of the tungsten compound from the surface material surface to a thickness of 100 um, the weight % of the tungsten compound in the flakes scraped off at a thickness of 100 um may be 0.01% by weight or more, and even if the weight % is high in particular near the surface, or conversely, the weight % of the content on the inside is high, sufficient termite control effect can be obtained. There is no limitation on the distribution form of the content. However, in the present invention, it is preferable that the content is high near the surface.

[0024] As a method for preparing the slurry liquid of the present invention, when the tungstate or ammonium tungstate is easily dissolved in water, a slurry may be prepared using a volatile solvent such as non-aqueous ethanol, isopropanol, or butanol, and a binder may be added thereto. In this case, it is preferable to add an amount equal to or greater than the weight of the control agent to the control agent. It is also possible to apply a solvent that is difficult to volatilize, but it is preferable to use an alcohol-based solvent. As another method, the surface of the nanoparticles of tungstic acid or tungstate may be covered with a binder such as a urea-based, melamine-based, phenol-based, epoxy-based, acrylic-based, polyester-based, urethane-based, nitrile rubber-based, styrene butadiene rubber-based, butyl rubber-based, silicone rubber-based, acrylic rubber-based, or urethane rubber-based binder and cured. To vitrify a cellulose-containing material, an organic solvent in which tetraethoxytitanium or tetrapropoxysilane is dissolved is mixed with the control agent of the present invention and applied to the surface, hydrolyzing the cellulosic material from the surface to the inside region, and the control agent is fixed in the glass component, thereby improving corrosion resistance, weather resistance, and surface strength. In this case, an organic-inorganic hybrid material containing a component with Ti and Si as the main skeleton may be used.

[0025] In order to maintain the function of the control agent for a longer period, a chelating agent or a buffer solution may be used.

[0026] Colorants may also be used, including inorganic pigments (e.g., iron oxide, titanium oxide and Prussian blue), and organic dyes such as alizarin dyes, azo dyes or metal phthalocyanine dyes, and also trace elements such as iron, manganese, boron, copper, cobalt, zinc, and their salts.

[0027] The cellulose-based material of the present invention may be a wood-based material or a plant-based material, and particularly, a material containing cellulose. Examples of the material include wood and scraps used in building materials. Examples include threads and cloth used as fibers, and clothing and structures using them. Examples of pulp include coniferous trees, broad-leaved trees, hemp, paper mulberry, Mitsumata, sugarcane pomace, grass reeds, fruit pomace, and recycled waste paper. Examples include resins made from cellulose, and objects made of cellulose materials may be in the form of plates or rods, or even strings or threads. Furthermore, they can be used for buildings, general residential structures, boats made of wood, playground equipment, fences, furniture, etc. There is no particular limit to the type of use. Other examples include silk, glass wool, rock wool, cellulose fiber, wool (wool breath), felt, cork, carbonized cork, polystyrene foam, polyethylene foam, EVA foam, PP foam, PET foam, urethane foam, rubber sponge, phenol foam, and insulation board.

[0028] As a method for incorporating the slurry having the termite control effect of the present invention into a structure made of a cellulose-containing material, it is effective to incorporate the slurry into the cellulose-based material, so that the slurry can be permeated into the structure by the osmotic pressure using a solvent. This can be done by applying a general paint with a spray gun, or by applying with a paint brush or a sponge roller, and can be done in the same manner as normal paint painting. In addition, when using a vacuum device, the slurry can be applied once and then permeated by reducing the pressure, or by permeating under pressure. After these applications, a heating treatment at room temperature or above room temperature is preferably performed to remove the solvent in the slurry, or the monomer in the slurry is polymerized, or the nanoparticles of the tungsten compound of the present invention are fixed by fusion with a polymerization reaction or thermoplastic component.

[0029] As a supplementary note, when a binder is added to the termite control slurry of the present invention and the slurry is applied to wood, the termite control effect is maintained even after immersion in water for one month, whereas general organic termite repellents and insecticides dissolve in water and lose their termite repellent and insecticidal effects.

[0030] The components containing the nanoparticles of the tungsten compound of this invention may have a repellent effect, and this is expected to be utilized as a feature of this material. For example, when it has a repellent effect, it acts as a repellent that keeps pests away, and when it does not have a repellent effect, it has an anticidal effect against termites. It is characterized by being a compound that has at least one of the functions of a repellent effect and an anticidal effect.

[0031] The control effect of using the nanoparticles of the tungsten compound of the present invention on various insects was tested and it was found to be at least effective against wood-eating beetles, such as bark beetles, longhorn beetles, beetles, weevils, dermestid beetles, ants, anemone wasps, stink bugs, ticks, bedbugs, booklice, burrs, Indian meal moths, red beetles, red flour beetles, dust beetles, flathead beetles, narrow flathead beetles, mealworms, centipedes, and slugs, and it was also found to have a control effect that repels moths.

[0032] Pests that can be controlled by the present invention include, but are not limited to, Collembola, Cyprinodontida, Dermaptera, Termitida, Phasmida, Orthoptera such as Orthoptera, Termites, Blattella such as cockroaches, Cyprinodontida such as booklice, lice, and biting lice, Thrips, Hemiptera such as planthoppers and leafhoppers, circular stink bugs, brown marmorated stink bugs, metallouse bugs, and bedbugs, Hymenoptera such as ant wasps, ants, hornets, and paper wasps, wood beetles, longhorn beetles, longhorn beetles, longhorn beetles, weevils, dermestida, and red beetles. It is effective against Coleoptera such as red flour beetles, dust beetles, flathead beetles, slender flathead beetles, and mealworms, Fleas such as cat fleas, Diptera such as Aedes aegypti and Culex pipiens, Lepidoptera such as the Indian meal moth and the Indian meal moth, ticks and other mites, spiders such as the redback spider, centipedes and other myriapods, mollusks such as the brown slug, the African snail, and the apple snail, and the New Guinea spearhead flatworm. The most effective insects are wood-eating pests in the order Blattella and the infraorder Termitidae, such as the Japanese termite (Deucotermes sp.), speratus, Coptotermes formosanus, Glyptotermes fucus, Glyptotermes satsumensis, Glyptotermes nakajimai, Glyptotermes kodamai, Incisitermes minor, Neotermes koshunensis, Cryptotermes domesticus, Hodotermopsis japonica, Reticulitermes miyatakei, Odontotermes formosanus, Nlasutitermus takasagoensis, and Capritermes nitobei can be mentioned.

[0033] The termite control agent of the present invention includes existing insecticides or chemicals used as repellents, such as neonicotinoid insecticides that are effective against pests resistant to pyrethroid insecticides, organophosphorus insecticides, and carbamate insecticides. Specific examples include imidacloprid, clothianidin, acetamiprid, and thiamethoxam. Furthermore, an instantaneous effect can be achieved by using organophosphorus insecticides, carbamate insecticides, neonicotinoid insecticides, and the like in combination. In this case, the same effect can also be achieved by first treating with an insecticide and then using the termite control agent of the present invention. Alternatively, a liquid obtained by mixing these insecticide components with the termite control agent of the present invention can be used. Effects of the Invention

[0034] By using the nanoparticles of the tungsten compound of the present invention in cellulose-based material-containing boards, rods, pillars and other structures, buildings, playground equipment, fences and furniture, it is possible to provide a termite control effect while also maintaining waterproofing and weather resistance. [Brief description of the drawings]

[0035] [Figure 1] As an example of ammonium tungstate, the composition of Pd-added Nap·(NH3)nP·mWO3 as evaluated by SEM-EDX is shown in Figure 1. [Diagram 2] Figure 2 shows an example of the composition of a termite control agent made of ammonium tungstate, which is composed of W, N, and O. [Diagram 3] SEM image of ammonium tungstate, which is composed of W, N, and O, as shown in Figure 2. [Figure 4] A TEM image of ammonium tungstate, which is composed of W, N, and O, as shown in Figure 2. [Diagram 5] The composition of 20 nm tungsten oxide nanoparticles as evaluated by SEM-EDX is shown in Figure 5. [Figure 6] A TEM image of 20 nm tungsten oxide nanoparticles is shown in FIG. [Figure 7]This is an image of a colored wood bar with nanoparticles permeating from the surface to the inside. [Figure 8] An image is shown of tungsten oxide particles of a few microns in size dispersed at 3 weight percent and sprayed onto the sides of a wooden bar. [Figure 9] An image of a core-shell structure in which the surface of a tungstate or tungstic acid particle is coated with resin is shown. [Figure 10] The experimental set-up diagram shows how wood is placed in the center of a plastic container to evaluate the killing effect of termites. [Figure 11] The experimental set-up diagram shows how the termite repellent effect was evaluated by placing a piece of wood in the center of a plastic container with paper towels on either side of the wood. [Figure 12] This photo shows the state when a piece of wood was placed in the center of a plastic container with paper towels placed on both sides of the wood to evaluate its termite repellent effect. [Figure 13] An image of the experimental set-up used to evaluate the anti-termite effect was shown, in which a plastic container measuring 8 cm in diameter and 5 cm in height was filled with shallow soil and wood (1.8 cm x 2.5 cm x 3 cm) was placed inside. [Figure 14] A photo taken on the 12th day of the experiment, with wood that had been treated with the insecticide and untreated wood placed inside. [Figure 15] A photo of an experimental set-up in which filter paper is placed in a plastic container measuring 8 cm in diameter and 5 cm in height to examine the disappearance of the filter paper when eaten by termites and its anticidal effect. [Figure 16] A photograph comparing the disappearance of filter paper eaten by termites. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The tungsten compound of the present invention is typically expressed as an ammonium tungstate salt, M p (NH3) n-P ·Cl q mWO3 rH2O, M p (NH4) 2x-p ·Cl q (WO4)x zH2O or M p (NH4) 2x ·Cl q (WO4) x (WO3) y zH2O(n>0,n>P≧0,m>0,r≧0,q≧0,x>0,y≧0,Z≧0,M:Li,Na,K,Cs,H,Ca,Mg), M as tungstate 1-T Examples of tungsten compounds include those that contain at least one of the following: WO3·zH2O (M: Na, Li, K, Cs, H, Ca, Mg, 1≧T≧0, Z≧0). Some of these have their ammonia sites replaced with other monovalent metal ions, and some even become hydrated crystals. When both are sized into nanoparticles, they have been experimentally shown to be highly effective in controlling termites. In addition, tungstate salts, which are salt cations of monovalent or divalent metal ions, also show similar termite control effects. H2WO4 and H4WO5 are typical compositional formulas for tungstic acid, and these also show similar termite control effects, as do nanoparticles of tungsten oxide.

[0037] In addition, ammonium tungstate is expressed as ammonium tungstate, M p (NH3) n-P ·Cl q mWO3 rH2O, M p (NH4) 2x-p ·Cl q (WO4) x zH2O or M p (NH4) 2x ·Cl q (WO4) x (WO3) y It is expressed as zH2O (n>0, n>P≧0, m>0, r≧0, q≧0, x>0, y≧0, Z≧0, M: Li, Na, K, Cs, H, Ca, Mg). The same effect is observed when the material is heated from a hydrated state to a non-hydrated state.

[0038] Some of the specific measurement data are shown below. Figure 1 shows an example of the composition of ammonium tungstate as evaluated by SEM-EDX. In this case, the sample does not contain chlorine, but has had ammonia replaced with Na and Pd added. Samples were made by replacing ammonia with Na and varying the amount of Na. Samples containing chlorine were also made. This notation is used as a general expression for ammonium tungstate, and is written as M p (NH3) n-P ·Cl q mWO3 rH2O, M p (NH4) 2x-p ·Cl q (WO4) x zH2O or M p (NH4) 2x ·Cl q (WO4) x (WO3) y Expressed as zH2O(n>0, n>P≧0, m>0, r≧0, q≧0, x>0, y≧0, Z≧0, M: Li, Na, K, Cs, H, Ca, Mg).

[0039] The following shows some of the specific measurement data when ammonia is not replaced with other metal elements. The names of the SEM and TEM used are listed below. The SEM is a Hitachi High-Technologies Corporation SEM model S-4800. The TEM is a Hitachi High-Technologies Corporation model H-7650. An example of the composition evaluated with SEM is shown in Figure 2. As a result, it is confirmed to be composed of W, N, and O. Since hydrogen cannot be detected by SEM-EDX, the composition analysis shows that it is composed of three components. However, to be precise, it does contain hydrogen, and the material is contained as ammonia. Figures 3 and 4 show SEM and TEM images of the material with this composition. From these results, it can be observed that the size is 5 nm to 20 nm.

[0040] In the tungsten compound shown in Figure 2, it was found that tungsten compounds in which 1 W atom is substituted with 0.1 or 0.3 Mo atoms also have the same termite control effect.

[0041] Next, in order to effectively use these materials as termite control agents, there are problems such as weather resistance, particularly when they are dissolved in water, they cannot maintain their long-term performance, and if they are too large, they do not penetrate into the tissue of the cellulose-containing material of the adherend, so they remain on the surface of the adherend and fall off over time. As shown in the present invention, it is better to make the tungsten compound of the control agent 100 nm or less, preferably 50 nm or less.

[0042] The present invention achieves water resistance and prevents falling off due to aging by penetrating a tungsten compound into a cellulose-containing material with a particle size of 50 nm or less and fixing it with an adhesive. As a side note, when a tungsten compound with a particle size of 50 nm or less penetrates into an adherend, it is difficult to dissolve, and even without the addition of an adhesive (binder component), it is significantly improved over the one with an average particle size of 1 um used as a comparative example.

[0043] Tungsten oxide nanoparticles of 20 nm, the composition of which is shown in SEM-EDX and TEM images in Figures 5 and 6, were dispersed in isopropanol at 3 wt% and sprayed onto the sides of a 5 cm square wooden bar. When the tungsten oxide nanoparticles were allowed to penetrate from the surface of the bar to the inside, they penetrated all the way to the inside, as shown in Figure 7. As a comparative example, tungsten oxide particles of several microns were dispersed at 3 wt% and sprayed onto the sides of a wooden bar, resulting in particles remaining only on the surface of the bar, as shown in Figure 8. When 1 L of water was poured over these two samples from the outside and washed away, most of the several micron particles of tungsten oxide that were on the bar in the comparative example were washed away, and the termite control effect was almost completely lost.

[0044] Similar results were obtained when ammonium paratungstate nanoparticles were used instead of tungsten oxide nanoparticles.

[0045] Tungstates such as sodium tungstate and lithium tungstate are easily dissolved in water, so a non-aqueous solvent is used in the present invention, and the adhesive contains the tungstate, resulting in the same state as when tungsten oxide nanoparticles are sprayed, and similar effects can be obtained. In addition, a resin coating as shown in Figure 9 is applied to the particle surface of tungstates such as sodium tungstate and tungstic acid to form a core-shell structure, preventing dissolution in the solvent and improving dispersibility in the solvent.

[0046] It was experimentally confirmed that the control effect is further improved by adding oxides of Ti, Sn, In, Ga, Cu, and Ag to the termite control slurry using nanoparticles of tungsten compounds. Specifically, it was experimentally confirmed that the termite control effect is improved by adding at least 0.1% by weight, preferably 1% by weight, of titanium oxide, stannous oxide, stannic oxide, and indium oxide to the weight of the tungsten compound. In addition, the termite control effect was also confirmed to be the same when oxides of iron and copper were included.

[0047] As a specific example, a termite control slurry consisting of isopropanol containing 10% by weight of an acrylic emulsion (R-5HN manufactured by Shin-Nakamura Kogyo Co., Ltd.) as a binder and 5% by weight of ammonium tungstate salt with an average particle size of 5 to 10 nm was applied to a cellulose-containing material, and a sample was prepared by permeating the slurry. The surface of the material was polished with sandpaper, and the termite control effect was examined over a one-year period. As a result, it was found that a cellulose-containing member exhibiting a termite control function can be produced by having a tungsten compound amount of 0.01% by weight or more at a location of a surface layer thickness of 100 um of the material. In addition, a similar effect was obtained even when the solvent was water. In particular, in the present invention, when using tungsten compound nanoparticles that are soluble in polar solvents, a nonpolar solvent is preferable as the solvent, and when using tungsten compound nanoparticles that are insoluble in nonpolar and polar solvents, the solvent type is not limited.

[0048] In addition, to evaluate water resistance, a termite control slurry was sprayed 1m onto a 20cm long cypress timber measuring 5cm square with 5% by weight of an aqueous organic-inorganic hybrid resin acrylic resin binder (Ceranete WHW-822, manufactured by Dai Nippon Ink Co., Ltd.), which has a nano-order chemically composite structure of inorganic polysiloxane and organic acrylic resin. The slurry was made of water containing 2% by weight of ammonium tungstate with an average particle size of 10nm. 2 The coating was applied at 10g per unit area. This was soaked in water for one day and then dried 30 times, and the termite control effect was then examined. A strong termite control effect was confirmed. This sample was also placed on soil outdoors to examine the termite control effect over a period of five years, and the termite control effect was still maintained even after five years.

[0049] Although the ammonium tungstate of the present invention is not highly soluble, it is slightly soluble in water, so it is prone to the Ostwald ripening phenomenon, and it has been confirmed that when it is immersed in a cellulose-based wood material and dried once, the particles grow within the cell structure. Therefore, by dispersing it as nanoparticles in water or other solvents within the cell structure and increasing the particle size during drying, it is possible to suppress the loss of the ammonium tungstate to the outside of the cellulose-based wood material.

[0050] The definition of the pest control slurry of the present invention is that it is composed of a tungsten compound of at least 50 nm or less added to a solvent, and includes a dispersion liquid, emulsion, and a state in which solid and liquid are separated. In use, it is desirable to disperse the tungsten compound nanoparticles in a solvent by surface treatment with a binder or surfactant, or by charging and dispersing the nanoparticles. When aggregated, the penetration into porous materials such as cell structures such as wood and cellulose tends to decrease. EXAMPLES EXAMPLES

[0051] The following examples were placed in a place without light and evaluated. Figure 10 shows the evaluation method used in this experiment. In the set shown in Figure 10, wood was placed in the center of a plastic container, and the temperature was controlled by an air conditioner to be around 20°C as room temperature. Wood was placed in a plastic case. Hinoki cypress was used as the wood. The size was 1 cm thick x 5 cm high x 10 cm wide. 2 ml of pest control slurry was soaked into the wood. As the pest control agent slurry, tungsten oxide powder with an average particle size of 20 nm was added to water to make it 3% by weight, and dipropylene glycol was further added to this water to make it 6% by weight. As a comparative example, water was added with 6% by weight of dipropylene glycol, and the same amount was added to the wood. 20 Yamato termites were placed in this container, the lid was closed, and the survival state was observed 5 days and 10 days later. The results are shown in Table 1. The numbers in the table indicate the number of survivors. The Yamato termites were completely wiped out in the wood containing the pest control agent. In the comparative example, all Yamato termites were alive. It was found to have a pest control effect that shows ant-killing effects in a short period of time.

[0052] [Table 1] EXAMPLES

[0053] In Example 1, isopropanol was used as the solvent, and sodium tungstate NaWO3 was used as the component of the pest control liquid. This shows the case where oleic acid, an organic substance with a low vapor pressure, was used as the component dissolved in the solvent. Oleic acid is an oil, so it has a water-repellent effect and does not dissolve in water. Wood was placed in a plastic case. Hinoki was used as the wood. The size was 1 cm thick x 5 cm high x 10 cm wide. 2 ml of pest control slurry was soaked into the wood. As a comparative example, isopropanol was used in which oleic acid was added to 2% by weight. As this example, isopropanol, a pest control agent, and oleic acid were used. As the pest control slurry, a pest control agent powder with an average particle size of 50 nm was added to isopropanol to 1% by weight, and oleic acid was further added to 2% by weight, and a slurry was prepared using an ultrasonic device. At this time, the isopropanol was evaporated and dried for both woods. Next, 20 Yamato termites were placed in the container and observed. The results are shown in Table 2. The numbers in the table indicate the number of survivors. As a result, in the evaluation using wood containing the control agent, all Yamato termites had been wiped out after 10 days. In the wood treated with isopropanol only, Yamato termites were still alive after 10 days. During the observation period, 10 Yamato termites were found dead. This shows that the control is effective in a short period of time.

[0054] [Table 2] EXAMPLES

[0055] The evaluation method used in this experiment is shown in Figure 11. The room temperature was controlled by an air conditioner to be around 20°C. The control agent, ammonium tungstate, had an average particle size of 30 nm (NH3) 0.25WO3 powder was added to water to make it 3% by weight, and further, acrylic emulsion binder (R-5HN manufactured by Shin-Nakamura Kogyo) was added to this water to make it 6% by weight. This liquid was used as the pest control slurry. Wood was placed in a plastic case, and paper towels were placed on both ends of the wood. Plywood was used as the wood. The size was 1 cm thick x 5 cm high x 10 cm wide. Each paper towel was soaked in 1 ml of water and pest control slurry. At this time, both paper towels were allowed to dry naturally. 20 Yamato termites were placed in the container on the paper towel containing the pest control agent side and observed. The results are shown in Table 3. As a result, not a single Yamato termite was found on the paper towel containing the pest control agent. All Yamato termites had moved to the water side. No Yamato termites were killed during this observation period. Figure 12 shows a photograph of the state after evaluation. It can be seen from this photograph that they have moved toward the water side. It was found that there was a pest control effect as a repellent effect in a short period of time.

[0056] [Table 3] EXAMPLES

[0057] In Example 3, the control agent ammonium tungstate (NH3) 0.25 The control effect due to the difference in size was investigated by using WO3 with different average particle sizes. 0.25Powder with different average particle sizes of WO3 was added to water to make it 3% by weight, and further acrylic emulsion binder (R-5HN manufactured by Shin-Nakamura Kogyo) was added to make it 6% by weight. This was used as a pest control slurry. For the water only, acrylic emulsion binder (R-5HN manufactured by Shin-Nakamura Kogyo) was added to make it 6% by weight. In this case, both paper towels were dried before putting the Yamato termites in. 50 Yamato termites were placed in the paper towel containing the pesticide and observed. The results are shown in Table 4. Table 4 shows the number of survivors after two days. As a result, not a single Yamato termite was found on the paper towel containing the pesticide. All Yamato termites had moved to the water side. During this observation period, no Yamato termites died. It was found that the pest control effect as a repellent effect was observed in a short time. Furthermore, from this result, it was found that a size of at least 100 nm, preferably an average particle size of 50 nm or less, is preferable.

[0058] [Table 4] EXAMPLES

[0059] In Example 4, the control agent solution was mixed with ammonium tungstate (NH3) 0.25 WO3 was used with 10% by weight of TiO2 5 nm nanoparticles added. In addition, a polyurethane binder (Arakawa Chemical Industry's Yuriano W600) was used. This was used as the pest control slurry. Wood was placed in a plastic case, and paper towels were placed on both ends of the wood. Plywood was used as the wood. The paper towels were soaked in water and a pest control agent. The pest control agent was (NH3) 0.25Powder of WO3 with different average particle sizes was added to water to make it 3% by weight, and polyurethane binder (Uriano W600, manufactured by Arakawa Chemical Industries) was added to make it 6% by weight. For the comparative example, water was added to make it 6% by weight (Uriano W600, manufactured by Arakawa Chemical Industries). At this time, both paper towels were dried. 50 Yamato termites were placed in the container on the paper towel containing the control agent and observed. The results are shown in Table 5. Table 5 shows the number of survivors after 2 days. From these results, it was found that a size of at least 100 nm, and preferably an average particle size of 50 nm or less, is preferable. In addition, compared with the results of Example 4, it was found that the repellent effect was further strengthened by adding TiO2.

[0060] [Table 5] EXAMPLES

[0061] In Example 5, 10% by weight of SnO2 5 nm nanoparticles were added instead of TiO2. This was used as the pest control slurry. Wood was placed in a plastic case, and paper towels were placed on both ends of the wood. Cedar boards were used as the wood. The paper towels were soaked in water and a pest control agent. The pest control agent was (NH3) 0.25 Powder of WO3 with different average particle sizes was added to water to make 3% by weight, SnO2 5nm nanoparticles were added to the water to make 0.3% by weight, and a binder was further added to make 6% by weight to make a pest control slurry. At this time, both paper towels were dried. 50 Yamato termites were placed in the container on the paper towel containing the pesticide side and observed. The results are shown in Table 6. Table 6 shows the number of survivors after 2 days. From these results, it was found that a size of at least 100 nm, and preferably an average particle size of 50 nm or less, is good. Compared with the results of Example 4, it was found that the addition of SnO2 further strengthened the repellent effect.

[0062] [Table 6]

[0063] Similar results were also seen for oxides of In, Ga, Cu, and Ag. It was found that the repellent effect was improved when oxides of these elements were included. EXAMPLES

[0064] In Example 1, the control agent ammonium tungstate was (NH3) 0.15 Na 0.1 W 1-x Mo x The nanoparticles were prepared by replacing W with Mo in the range of 0.1 to 0.5 in O3·0.2H2O, and added at 10% by weight. In addition, a polyurethane binder (Arakawa Chemical Industries, Yuliano W600) was used as the binder. Wood was placed in a plastic case, and paper towels were placed on both ends of the wood. The paper towels were soaked in water and a pest control agent. The pest control agent was (NH3) 0.25 W 1-x Mo x Powder of O3 with an average particle size of 50 nm was added to water to make it 3% by weight, and a binder was further added to make it 6% by weight. At this time, both paper towels were dried. 50 Yamato termites were placed in the container with the paper towel containing the pesticide and observed. The results of the termite killing effect when W was replaced with Mo are shown in Table 7. Table 7 shows the number of survivors after 4 days. From this result, it was found that the addition of Mo improved the termite killing effect.

[0065] [Table 7] EXAMPLES

[0066] The experimental method is shown in Figure 13. Soil was shallowly placed in a plastic container with a diameter of 8 cm and a height of 5 cm, and sodium was added to the water as a treatment group. 0.3 (NH3) 0.5 ·Cl 0.013ml of control slurry was made by adding 5% by weight of .WO3.0.5H2O and 5% by weight of dipropylene glycol, and 3ml of water was added as a control. 20 Japanese termites were placed in the wood (1.8cm x 2.5cm x 3cm) and observed. The results of the anticidal effect are shown in Table 8. The numbers in the table indicate the number of survivors. From these results, one individual was left in the wood that had been treated with the anticide by the 11th day, and all individuals had died by the 12th day. In contrast, no individuals had died in the control area even by the 13th day. Figure 14 shows a photograph of the wood treated with the anticide and untreated wood after the experiment on the 12th day. All Japanese termites had been killed in the wood treated with the anticide. All of the untreated wood was alive. From these results, it was clear that the anticidal effect was remarkable.

[0067] [Table 8] EXAMPLES

[0068] The experimental method is shown in Figure 13. Soil was shallowly placed in a plastic container with a diameter of 8 cm and a height of 5 cm, and sodium was added to the water as a treatment group. 0.3 (NH3) 0.5 ·Cl 0.01 3ml of the pesticide was added to the wood (1.8 x 2.5 x 3cm) which was soaked in 3ml of water as a control, and 20 Yamato termites were placed in the wood and observed. The results of the anticidal effect are shown in Table 9. The numbers in the table indicate the number of survivors. On the 11th day, only one individual remained in the area that had been soaked in the pesticide, and by the 12th day, all individuals had died. In contrast, no individuals had died in the control area even on the 13th day.

[0069] [Table 9] EXAMPLES

[0070] Ammonium paratungstate powder was crushed with beads to produce a powder with an average particle size of 1 um to 20 nm. Paints were produced for each size using ammonium paratungstate powder of different sizes. The solvent was fixed to water, the powder was contained at 5 wt%, and 10 wt% of an acrylic emulsion binder (R-5HN manufactured by Shin-Nakamura Kogyo) was added as a binder. 5 ml of each of these paints was sprayed onto a cypress rod of 5 cm x 5 cm x 5 cm in size and dried to produce a sample. The binder was cured at 130°C for 4 minutes. The surfaces of these samples were lightly polished with 2000-grit sandpaper. Using these samples, the termite control effect was confirmed by the method shown in Example 1. 20 Yamato termites were put in and observed. The amount of ammonium paratungstate on the polished surface was expressed as the atomic ratio of the carbon component derived from wood and W. In Table 10, the atomic ratio in SEM-EDX was standardized as 1 using a pest control agent of 50 nm particles of ammonium paratungstate, and the other values ​​were also treated in the same manner to compare the amount of W present in the wood. Here, the values ​​for the polishing depth of 0 mm in Table 9 were obtained by polishing the wood to less than 0.1 mm after application so that the wood was visible, making it the outermost surface. As a result, it can be seen that the 1 um particles of the comparative example were almost completely lost by polishing the surface, while those of the present invention penetrated from the surface to the center.

[0071] [Table 10]

[0072] Using the sample of Example 10 whose outermost surface had been polished, the control effect against Yamato termite was examined. Table 11 shows the results of investigating the termite killing effect when a 50 nm particle size pesticide was used. In this case, a 1 um particle size was used as a comparison example. The numbers in the table show the number of surviving termites. From these results, it was found that the effect was low when using the conventional large particle product.

[0073] [Table 11] EXAMPLES

[0074] In Example 10, the size of the ammonium paratungstate powder was changed, and the W / C ratio of the polished surface when 0.5 mm was scraped off from the outermost surface was normalized as 1, and the relationship between the size of ammonium paratungstate, the W / C value, and the termite killing effect was investigated. 20 Yamato termites were put in and observed. Table 12 shows the number of surviving Yamato termites after 10 days. As a result, as shown in Table 12, it was found that when the size was 500 nm or less, ammonium paratungstate remained even after polishing, when it was 100 nm or less, it remained significantly, and when it was 50 nm or less, the amount was the same as that of a size of 20 nm. It was confirmed that the amount of remaining ammonium paratungstate increased by making it at least 100 nm or less. It was found that there was a correlation between this remaining amount and the termite killing effect, and from this result, it was found that the average particle size is 100 nm or less, preferably 50 nm or less, in order to penetrate at least the inside of the cellulose-based wood material.

[0075] [Table 12]

[0076] A similar test was carried out in Example 11, except that ammonium paratungstate was replaced with tungsten oxide powder and cypress was replaced with cedar wood, with similar results. EXAMPLES

[0077] The experimental method is shown in Figure 15. Filter paper was placed in a plastic container with a diameter of 8 cm and a height of 5 cm, and 20 Yamato termites were placed in the filter paper. The filter paper used in this experiment contained water containing (NH3) as a pest control agent. 0.2 ·Cl 0.01The filter paper was soaked with 1 ml of a control slurry made by adding 0.5% by weight of WO3 and 2% by weight of dipropylene glycol, and dried at 80°C for 1 hour. Untreated filter paper was used as a comparative example. The filter paper and Yamato termites were placed in a container, and the results of the anticidal effect after 10 days are shown in Table 13. Figure 15 shows a comparison photo of filter paper eaten by termites. The numbers in the table show the number of survivors. From this result, all Yamato termites were annihilated on the filter paper treated with the control agent. On the other hand, all Yamato termites survived on the untreated filter paper of the comparative example. Also, from the photo in Figure 16, the untreated filter paper was eaten and damaged, but the filter paper treated with the control agent was almost intact. From this result, it was found that the control agent of the present invention has a strong anticidal effect on termites and a strong protective effect on cellulose-based materials.

[0078] [Table 13] EXAMPLES

[0079] In Example 12, the amount of the control agent contained in the filter paper was changed to examine the anticidal effect. The weight of the filter paper was fixed at 1 g, and 1 ml of a slurry containing the control agent was soaked in water and dried at 80°C for 1 hour. 0.3·WO3 was added at 0.01mg, 0.05mg, 0.1mg, 0.5mg, 1mg, 2mg, 5mg, and 10mg, and then a fixed amount of 0.02g of dipropylene glycol was added to this liquid and stirred. Termiticidal effect was examined using the control liquid prepared by changing the amount of control agent added. 20 Yamato termites were put in. The results of the termiticidal effect after 20 days are shown in Table 14. The values ​​of the control agent in the table are for 1g of filter paper, so the amount of the control agent added is expressed as weight %. The numbers in the table for termites show the number of surviving termites. From these results, it was found that the filter paper treated with the control agent has a termiticidal effect when the amount added is at least 0.01% by weight per 1g of filter paper. As a comparative example, evaluation was performed using filter paper without the control agent added, and all of the termites survived without the control agent added. From this result, it is desirable that the control agent of the present invention has a strong termiticidal effect against termites, and that the material contains at least 0.01% by weight. Based on this result, it is desirable that the amount of the control slurry to be applied to wood materials or cellulose-containing materials by spraying, brushing, sponge roller, etc. is 0.01% by weight of the control agent in the applied and permeated portion.

[0080] [Table 14] [Industrial Applicability]

[0079] By impregnating cellulosic wood materials with the nanoparticles of the tungsten compound of the present invention, it is possible to control pests that feed on wood materials in materials, buildings, furniture, lumber, tableware, etc. that are made of cellulosic wood materials. [Explanation of symbols] 1. Resin film formed on the surface of tungsten compound 2. Core particles of tungsten compounds 3. Plastic Box 4 Test wood 5 Plastic Boxes 6 Paper towels 7 wood 8 Paper towels 9 Plastic boxes used for evaluation in the test 10 Paper towels soaked in a solution containing a repellent and dried 11 Paper towels that have been dried with water only 12 Plastic cup containers 13 Sample wood 14 Sat 15 Photograph of the result when wood soaked in water only was placed 16 Photograph of the results when wood soaked in a liquid containing a pesticide was placed 17 Plastic cup container 18 Filter paper 19 Filter paper soaked in water only 20 Filter paper soaked in pesticide

Claims

1. In the termite control agent, the average particle size is 50 nm or less and the M of ammonium tungstate salt is ｐ ・(NH ３ ) ｎ－Ｐ ・Cl ｑ ・mWO ３ ・rH ２ O.M. ｐ ・(NH ４ ) ２ｘ－ｐ ・Cl ｑ ・(W.O. ４ ) ｘ ・zH ２ O or M ｐ ・(NH ４ ) ２ｘ ・Cl ｑ ・(W.O. ４ ) ｘ ・(W.O. ３ ) ｙ ・zH ２ O (n>0, n>P>0, m>0, r>0, q>0, x>0, y>0, Z>0, M: Li, Na, K, Cs, H, Ca, Mg), M of tungstate １－Ｔ WO ３ ・zH ２ A termite control agent comprising a tungsten compound containing at least one of tungsten compounds selected from the group consisting of tungsten, arginine, potassium, cesium, potassium, potassium, phosphate ...

2. 2. A termite control agent according to claim 1, which is a tungsten compound in which W is substituted with Mo.

3. 3. A termite control slurry comprising the termite control agent according to claim 1 or 2 and an oxide containing at least one element selected from the group consisting of Ti, Sn, In, Ga, Cu and Ag.

4. A cellulose-containing member having a termite control function due to the amount of tungsten compound in a material mainly composed of cellulose impregnated with the termite control agent according to claims 1 to 3 being 0.01% by weight or more.

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