Insecticide potentiator, pest control method, and aqueous insecticide composition for thermal evaporation

Abstract

To provide an insecticidal efficacy enhancer capable of effectively enhancing the insecticidal efficacy of a pyrethroid insecticidal component with a relatively high vapor pressure contained in a water-based insecticidal composition for thermal transpiration.SOLUTION: An insecticidal efficacy enhancer is blended in a water-based insecticidal composition for thermal transpiration and contains, as an active component, a glycol compound having a hydroxyl group bonded to each of two adjacent carbon atoms of an alkane having 4 to 7 carbon atoms, wherein the water-based insecticidal composition contains a pyrethroid insecticidal component having a vapor pressure of 2×10-4 to 1×10-2 mmHg at 30°C.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an insecticidal efficacy enhancer that is incorporated into an aqueous insecticide composition for thermal evaporation containing a pyrethroid insecticidal component having a relatively high vapor pressure, a pest control method that uses an aqueous insecticide composition for thermal evaporation containing the insecticidal efficacy enhancer, and an aqueous insecticide composition for thermal evaporation containing the insecticidal efficacy enhancer.

[0002] As a flying pest control product for controlling flying pests such as mosquitoes, a so-called "liquid type mosquito repellent" is commercially available, which adopts a method of immersing an absorbent wick in a chemical solution containing an insecticidal component, leading the absorbed chemical solution to the top of the absorbent wick, and evaporating the insecticidal component into the atmosphere by heating the absorbent wick. The insecticidal component of the liquid type mosquito repellent is generally a pyrethroid insecticidal component. Conventionally, allethrin, prallethrin, furamethrin, etc. were the mainstream of pyrethroid insecticidal components, but in recent years, there is a tendency to use new components such as transfluthrin, metofluthrin, profluthrin, etc., which have excellent insecticidal activity.

[0003] In addition, there are two types of liquid mosquito repellents: oil-based kerosene-based formulas and water-based water-based formulas. Until now, oil-based formulas have been the mainstream of liquid mosquito repellents worldwide, but water-based formulas can reduce the risk of fire compared to oil-based formulas, and are said to be just as effective at killing pests as oil-based formulas, so it is expected that the demand for water-based formulas will increase in the future.

[0004] Conventional aqueous formulation flying pest control products include aqueous insecticides for thermal evaporation that use a liquid medicine containing a pyrethroid insecticidal component, a surfactant, and water (see, for example, Patent Document 1). The aqueous insecticide for thermal evaporation in Patent Document 1 is used in a method of thermally evaporating a liquid medicine using a liquid-absorbing wick for thermal evaporation, and is intended to maintain the balance of the component composition of the liquid medicine by blending a surfactant in the liquid medicine and to stably evaporate the pyrethroid insecticidal component over a long period of time.

[0005] Another conventional flying pest control product with an aqueous formulation is an aqueous agent for thermal evaporation that contains a thermally volatile agent, an organic solvent, and water (see, for example, Patent Document 2). In the aqueous agent for thermal evaporation of Patent Document 2, a large number of aqueous organic solvents and aqueous organic compounds are included as components equivalent to surfactants, and attempts have been made to adjust the volatility of the aqueous agent for thermal evaporation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 3-7207 [Patent Document 2] Japanese Patent Application Publication No. 7-316002 Summary of the Invention [Problem to be solved by the invention]

[0007] When using a flying pest control product indoors, in order to effectively enhance the control effect against flying pests, it is necessary for the pyrethroid insecticidal ingredient contained in the vaporized particles vaporized from the flying pest control product to effectively come into contact with the flying pests and reach the inside of the flying pests. For flying pest control products with an aqueous formulation, it is assumed that the pyrethroid insecticidal ingredient contained in the vaporized particles vaporizes while maintaining a balance with the surfactant (aqueous organic solvent or aqueous organic compound) and water.

[0008] In this regard, the aqueous insecticide for thermal evaporation in Patent Document 1 and the aqueous agent for thermal evaporation in Patent Document 2 aim to increase the evaporation stability and adjust the volatility in order to keep the concentration of the pyrethroid insecticidal component constant. That is, in the prior art including Patent Document 1 and Patent Document 2, only the evaporation performance was examined, and the problem of focusing on the pyrethroid insecticidal component itself contained in the evaporated particles and the technical idea of ​​effectively bringing the pyrethroid insecticidal component into contact with flying pests to enhance the insecticidal effect were not fully recognized at the time of the prior art.

[0009] The present invention has been made in consideration of the above problems, and aims to provide an insecticidal efficacy enhancer capable of effectively enhancing the insecticidal efficacy of a pyrethroid insecticidal component having a relatively high vapor pressure in an aqueous insecticidal composition for thermal evaporation containing the pyrethroid insecticidal component. Another aim of the present invention is to provide a pest control method and an aqueous insecticidal composition for thermal evaporation in which the insecticidal efficacy of the pyrethroid insecticidal component is effectively enhanced. [Means for solving the problem]

[0010] The present invention has discovered that the following configurations are highly effective in achieving the above object.

[0011] (1) An insecticidal efficacy enhancer containing as an active ingredient a glycol compound in which one hydroxyl group is bonded to each of two adjacent carbon atoms of an alkane having 4 to 7 carbon atoms, and having a vapor pressure of 2 x 10 at 30°C. -4 ~1×10 -2 An insecticidal efficacy enhancer that is incorporated into an aqueous insecticidal composition for thermal evaporation containing a pyrethroid insecticidal component having a potency of 1.0 mmHg. (2) The insecticidal efficacy enhancer according to (1), wherein the two adjacent carbon atoms of the alkane having 4 to 7 carbon atoms are carbon position numbers 1 and 2. (3) The insecticidal efficacy enhancer according to (2), wherein the glycol compound is at least one selected from the group consisting of 1,2-butanediol, 1,2-pentanediol, and 1,2-hexanediol. (4) The aqueous insecticide composition for thermal evaporation contains the pyrethroid-based insecticidal component, an aqueous organic compound, and water, and the aqueous organic compound contains 20 mass% or more of the glycol-based compound. (5) The insecticidal efficacy enhancer according to any one of (1) to (4), wherein the pyrethroid insecticidal component is at least one selected from the group consisting of transfluthrin, metofluthrin, profluthrin, meperfluthrin, heptafluthrin, dimefluthrin, and 4-methoxymethyl-2,3,5,6-tetrafluorobenzyl-2,2-dimethyl-3-(2-chloro-2-trifluoromethylvinyl)cyclopropanecarboxylate. (6) The insecticidal efficacy enhancer according to (5), wherein the pyrethroid insecticidal component is transfluthrin. (7) The insecticidal efficacy enhancer according to any one of (4) to (6), wherein the aqueous organic compound further contains a glycol ether compound. (8) The insecticidal efficacy enhancer described in (7), wherein the glycol ether compound is at least one selected from the group consisting of diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, and 3-methoxy-3-methylbutanol. (9) A method for controlling insects using an absorbent wick for thermal evaporation, comprising the steps of: immersing a lower part of the absorbent wick for thermal evaporation in an aqueous insecticide composition for thermal evaporation containing an insecticidal efficacy enhancer according to any one of (1) to (8); and guiding the aqueous insecticide composition for thermal evaporation absorbed from the lower part of the absorbent wick for thermal evaporation to an upper part of the absorbent wick for thermal evaporation and heating at 80 to 150° C., thereby evaporating the pyrethroid insecticidal component into the atmosphere. (10) The vapor pressure at 30°C is 2×10 -4 ~1×10 -2 The present invention relates to an aqueous insecticide composition for thermal evaporation, the composition comprising a pyrethroid insecticidal component having a viscosity of mmHg and an insecticidal efficacy enhancer having as its active ingredient a glycol compound in which one hydroxyl group is bonded to each of two adjacent carbon atoms of an alkane having 4 to 7 carbon atoms. Effect of the Invention

[0012] The insecticidal efficacy enhancer and pest control method of the present invention are extremely useful in an aqueous insecticide composition for thermal evaporation containing a pyrethroid insecticidal component having a relatively high vapor pressure, since they not only contribute to the evaporation stability and volatilization adjustment of the aqueous insecticide composition for thermal evaporation, but also effectively enhance the insecticidal efficacy of the pyrethroid insecticidal component contained in the aqueous insecticide composition for thermal evaporation. In addition, the aqueous insecticide composition for thermal evaporation of the present invention contains an insecticidal efficacy enhancer having as an active ingredient a glycol compound that enhances the insecticidal effect of the pyrethroid insecticidal component, making it an extremely excellent pest control product and extremely useful in practice. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The insecticidal efficacy enhancer, the pest control method, and the aqueous insecticide composition for thermal evaporation of the present invention will be described below. However, the present invention is not intended to be limited to the embodiments and examples described below.

[0014] <Aqueous insecticide composition for thermal evaporation> The aqueous insecticide composition for thermal evaporation of the present invention (hereinafter referred to as "aqueous insecticide composition") containing the insecticidal efficacy enhancer of the present invention has a vapor pressure of 2×10 at 30° C. -4 ~1×10 -2 According to the present invention, the vapor pressure at 30°C is 2×10 mmHg. -4 ~1×10 -2 The insecticidal efficacy of the aqueous insecticide composition for thermal evaporation containing a pyrethroid insecticidal component having a viscosity of mmHg can be enhanced by blending with an insecticidal efficacy enhancer having as its active ingredient a glycol compound in which one hydroxyl group is bonded to each of two adjacent carbon atoms of an alkane having 4 to 7 carbon atoms.

[0015] <Pyrethroid insecticide> Examples of pyrethroid insecticidal components include transfluthrin, metofluthrin, profluthrin, empenthrin, telallethrin, meperfluthrin, heptafluthrin, dimefluthrin, and 4-methoxymethyl-2,3,5,6-tetrafluorobenzyl-2,2-dimethyl-3-(2-chloro-2-trifluoromethylvinyl)cyclopropanecarboxylate. Among these, in consideration of thermal transpiration, insecticidal efficacy, stability, etc., transfluthrin, metofluthrin, profluthrin, meperfluthrin, heptafluthrin, dimefluthrin, and 4-methoxymethyl-2,3,5,6-tetrafluorobenzyl-2,2-dimethyl-3-(2-chloro-2-trifluoromethylvinyl)cyclopropanecarboxylate are preferred, and transfluthrin is more preferred. The pyrethroid insecticidal components listed above may be used alone or in a mixture of multiple types. In addition, in the case where the pyrethroid insecticidal component has optical isomers or geometric isomers based on asymmetric carbon in the acid moiety or alcohol moiety, these are also included in the pyrethroid insecticidal components that can be used in the present invention.

[0016] The content of the pyrethroid insecticidal component in the aqueous insecticide composition for thermal evaporation is preferably 0.1 to 3.0% by mass, more preferably 0.7 to 2.0% by mass. If the content is less than 0.1% by mass, the insecticidal effect may be reduced. On the other hand, if the content exceeds 3.0% by mass, the properties of the aqueous insecticide composition may be impaired.

[0017] <Insecticidal efficacy enhancer> The present inventors have conducted extensive research into aqueous insecticide compositions for thermal evaporation containing the above-mentioned pyrethroid insecticidal component, and have surprisingly found that a specific glycol compound can not only be used as one component (aqueous organic compound) of an aqueous insecticide composition for thermal evaporation, but also function as a component that enhances the insecticidal effect of the pyrethroid insecticidal component. That is, the present invention relates to an insecticidal efficacy enhancer containing as an active ingredient a glycol compound in which one hydroxyl group is bonded to each of two adjacent carbon atoms of an alkane having 4 to 7 carbon atoms.

[0018] <Glycol compounds> Examples of glycol compounds include 1,2-butanediol (boiling point: 194° C.), 1,2-pentanediol (boiling point: 210° C.), 1,2-hexanediol (boiling point: 223° C.), 3-methyl-1,2-butanediol (boiling point: 206° C.), 2,3-butanediol (boiling point: 177° C.), 4-methyl-2,3-pentanediol (boiling point: 190° C.), etc. Among these glycol compounds, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and 3-methyl-1,2-butanediol, in which the carbon position numbers of two adjacent carbon atoms are 1 and 2, are preferred, and 1,2-hexanediol is more preferred.

[0019] The reason why the incorporation of the glycol compound used in the present invention in an aqueous insecticide composition for heat evaporation exerts an excellent insecticidal efficacy enhancing effect is not clear, but it is thought that a hydrogen bond is formed between two hydroxyl groups present in the molecular structure of the glycol compound as a result of the two groups being adjacent to each other, and that this hydrogen bond has some favorable effect on the insecticidal efficacy enhancing effect of the pyrethroid insecticidal component.

[0020] In the aqueous insecticide composition for thermal evaporation containing a glycol compound, the content of the glycol compound as an insecticidal efficacy enhancer in the aqueous insecticide composition for thermal evaporation is preferably 2 to 70 mass%, more preferably 6 to 60 mass%. If the content is less than 2 mass%, there is a risk that sufficient insecticidal efficacy enhancement effect cannot be obtained. On the other hand, even if the content exceeds 70 mass%, not only will the insecticidal effect against flying pests and the effect of preventing indoor intrusion reach a plateau, but the danger of fire will increase, and there is a risk that the merit of the aqueous formulation will be lost.

[0021] <Aqueous organic compounds> The aqueous insecticide composition for thermal evaporation used in the present invention uses water as a solvent to prepare an aqueous formulation, and further contains an aqueous organic compound to solubilize the pyrethroid insecticidal component. By preparing the aqueous formulation in this way, the danger of fire can be reduced compared to oil-based formulations, and it is said that the insecticidal effect against pests is equal to or greater than that of oil-based formulations. The aqueous organic compound to be mixed to prepare the aqueous formulation is based on the premise that (1) it can solubilize the pyrethroid insecticidal component, (2) it has thermal evaporation properties, and (3) it is interposed between the pyrethroid insecticidal component and water and the three components are thermally evaporated while maintaining a certain ratio. In the present invention, the glycol-based compound that functions as an insecticidal efficacy enhancer may be mixed so that it becomes a part or the whole of the aqueous organic compound depending on the solubilizing ability for the pyrethroid insecticidal component, etc. In addition, the aqueous organic compound may be constituted by using other compounds, such as glycol ether compounds, together with the glycol-based compound. Glycol ether compounds are excellent in solubilizing ability and thermal transpiration ability of pyrethroid insecticidal ingredients, and are described as major aqueous organic compounds (also called surfactants or aqueous organic solvents) in Patent Documents 1 and 2. In the present invention, too, glycol ether compounds are useful as complementary components to glycol compounds.

[0022] <Glycol ether compounds> The glycol ether-based compound preferably has a boiling point of 150 to 300° C., more preferably 170 to 260° C. Examples of such glycol ether-based compounds include diethylene glycol monoethyl ether (boiling point: 202° C., hereinafter DEME), diethylene glycol monoisopropyl ether (boiling point: 207° C., hereinafter DEMIP), diethylene glycol monobutyl ether (boiling point: 231° C., hereinafter DEMB), diethylene glycol monoisobutyl ether (boiling point: 220° C., hereinafter DEMIB), diethylene glycol monohexyl ether (boiling point: 259° C., hereinafter DEMH), diethylene glycol mono 2-ethylhexyl ether (boiling point: 2 72°C), diethylene glycol monophenyl ether (boiling point: 283°C), triethylene glycol monomethyl ether (boiling point: 249°C), propylene glycol monotertiary butyl ether (boiling point: 151°C), dipropylene glycol monomethyl ether (boiling point: 188°C), dipropylene glycol monopropyl ether (boiling point: 210°C, hereinafter referred to as DPMP), 3-methoxy-1,2-propanediol (boiling point: 220°C), and 3-methoxy-3-methylbutanol (boiling point: 174°C, hereinafter referred to as Solfit). Among these glycol ether compounds, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, and 3-methoxy-3-methylbutanol are preferred. The above-listed glycol ether compounds may be used alone or in a mixture of two or more kinds.

[0023] The content of the aqueous organic compound in the aqueous insecticide composition for thermal evaporation is preferably 10 to 70% by mass, more preferably 30 to 60% by mass. If the content is less than 10% by mass, it may cause problems in the preparation of an aqueous formulation. In addition, the duration of the flying pest control effect is poor. On the other hand, if the content exceeds 70% by mass, not only will the insecticidal effect against flying pests and the effect of preventing indoor intrusion reach a plateau, but the danger of fire will increase, and there is a risk that the merit of the aqueous formulation will be lost. Among the aqueous organic compounds, the glycol-based compound used as an insecticidal efficacy enhancer is preferably contained in the amount described below. That is, the amount of the glycol-based compound in the aqueous organic compound is preferably 20 to 100% by mass. In addition, the amount of the glycol-based compound in the aqueous insecticide composition for thermal evaporation is preferably 2 to 70% by mass, more preferably 6 to 60% by mass. By using such a formulation, it is possible to maintain excellent thermal evaporation while making it possible to prepare an aqueous formulation, and further enhance the insecticidal efficacy.

[0024] The aqueous insecticide composition for thermal evaporation may contain other ingredients as long as the glycol compound added as an insecticidal efficacy enhancer enhances the insecticidal efficacy of the pyrethroid insecticidal component, without departing from the spirit of the present invention. For example, non-pyrethroid pest repellent components such as DEET, 1-methylpropyl 2-(2-hydroxyethyl)-1-piperidinecarboxylate (icaridin), and 3-(Nn-butyl-N-acetyl)aminopropionic acid ethyl ester (IR3535), terpene compounds such as citronellol, geraniol, linalool, p-menthane-3,8-diol, menthol, and menthone, natural essential oils having a repellent effect such as citronella oil, lavender oil, peppermint oil, lemon eucalyptus oil, and peppermint oil, antibacterial agents such as isopropylmethylphenol, antifungal agents, stabilizers such as dibutylhydroxytoluene (BHT) and methyl parahydroxybenzoate, pH adjusters, colorants, and deodorants such as tea extract and tea dry distillate can be appropriately blended. In preparing the aqueous insecticide composition for thermal evaporation, in addition to water, lower alcohols such as ethanol and isopropanol, hydrocarbon solvents such as kerosene, ester or ether solvents, solubilizers, and dispersants may be used as appropriate within the scope that does not impair the advantages of the aqueous formulation.

[0025] <Pest control methods> The aqueous insecticide composition for thermal evaporation prepared as described above is filled into a container body (not shown) equipped with a liquid-absorbing wick for thermal evaporation to form a pest control product (liquid-type mosquito repellent). That is, the aqueous insecticide composition for thermal evaporation is immersed in the aqueous insecticide composition for thermal evaporation, the absorbed aqueous insecticide composition for thermal evaporation is guided to the top of the liquid-absorbing wick for thermal evaporation, and heated at 80 to 150°C, thereby evaporating the pyrethroid insecticidal component into the atmosphere, which is applied to the pest control method.

[0026] The liquid container for containing the aqueous insecticide composition for thermal evaporation is generally made of a plastic such as polyolefin such as polypropylene, polyester, or polyvinyl chloride. An absorbent wick is attached to the top of the liquid container via an inner plug. In the case of an aqueous formulation, the material of the liquid container is preferably a polyolefin plastic such as polypropylene, taking into account the physical properties of glycol compounds and glycol ether compounds.

[0027] <Liquid-absorbing wick for heating and evaporation> By the way, the liquid-absorbing wick for thermal evaporation of liquid-type mosquito repellents is generally classified into a fired wick, a porous ceramic wick, a felt wick, a string-made wick, and a knotted wick, but in the present invention, a fired wick, a porous ceramic wick, a felt wick, and a string-made wick are preferably used, and a fired wick or a porous ceramic wick is more preferably used. The following describes the case where a fired wick or a string-made wick is used as the liquid-absorbing wick for thermal evaporation. The material of the liquid-absorbing wick for thermal evaporation is not particularly limited as long as it is stable against the aqueous insecticide composition for thermal evaporation containing a pyrethroid-based insecticide component and can absorb an aqueous solution by capillary action.

[0028] The fired core is obtained by firing a mixture of (a) an inorganic substance (inorganic powder, inorganic binder, etc.) or preferably (b) an organic substance (carbonaceous powder, organic binder, etc.) at 600 to 2000° C. Here, there are fired cores that contain a small amount of (b) and are composed almost exclusively of (a), and such fired cores are sometimes called porous ceramic cores.

[0029] The inorganic substance contains an inorganic powder as an essential component, but may contain an inorganic binder as an auxiliary component as necessary. Examples of inorganic powders include mica, alumina, silica, talc, mullite, cordierite, and zirconia. Among these, mica is a preferred material because it can generate relatively uniform micropores in the liquid-type mosquito-repellent liquid-absorbent wick. The inorganic powders listed above may be used alone or in a mixture of two or more types. The content of the inorganic powder in the liquid-absorbent wick for thermal evaporation is preferably 10 to 90% by mass, more preferably 30 to 70% by mass. The shape of the inorganic powder is preferably a fine powder of 50 mesh or less in terms of physical properties such as appearance, liquid absorption, and strength. However, this does not apply when a process such as pulverization is involved in the manufacturing process of the liquid-absorbent wick for thermal evaporation.

[0030] Examples of inorganic binders include clay (kaolin clay), various clays such as bentonite and halloysite, tar pitch, water glass, etc. Among these, clay is a preferred material because of its excellent binding action. The above-listed inorganic binders may be used alone or in a mixed state of a plurality of types. The content of the inorganic binder in the liquid-absorbent wick for thermal evaporation is preferably 5 to 50 mass %, more preferably 10 to 40 mass %. The inorganic binder has poor binding action at room temperature, but when fired at 600 to 2000°C, it exhibits sufficient binding action and can be suitably used as a liquid-absorbent wick for thermal evaporation.

[0031] Examples of the organic substance include carbonaceous powders such as graphite, carbon black, activated carbon, charcoal, and coke, and organic binders such as carboxymethylcellulose (CMC), acrylic resin, and polyolefin resin. Of these, graphite is a preferred material because it has a relatively uniform shape and few impurities. When carbonaceous powders such as graphite are blended, the appearance, color tone, liquid absorption, strength, and the like of the liquid absorbent wick for thermal evaporation can be improved. The above-mentioned carbonaceous powders or organic binders may be used alone or in a mixed state of multiple types. The content of the organic substance in the liquid absorbent wick for thermal evaporation is preferably 5 to 40 mass%. Within this range, continuous pores are generated in the liquid absorbent wick for thermal evaporation by gases such as carbon monoxide and carbon dioxide generated during the process of firing the liquid absorbent wick for thermal evaporation, and a porous structure sufficient to exhibit liquid absorption performance can be formed by capillary action.

[0032] In addition to the above substances, preservatives and antioxidants such as 4,4'-methylenebis(2-methyl-6-t-butylphenol) and stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate may be appropriately added to the liquid-absorbent wick for thermal evaporation.

[0033] The cord-made core is formed by covering the outer periphery of the core material with a sheath material for absorbing and volatilizing the aqueous insecticide composition for thermal evaporation, and the sheath material is generally formed as one or more fiber aggregates selected from natural fibers, synthetic fibers, and inorganic fibers. In the cord-made core, the core material has a shape-retaining function of the absorbent core for thermal evaporation. The material does not necessarily have to have a function for absorbing the aqueous insecticide composition for thermal evaporation, and can be formed, for example, of a thermoplastic and / or thermosetting synthetic resin having a heat resistance of 130°C or more. In order to enhance the shape-retaining function, the thermoplastic and / or thermosetting synthetic resin can be reinforced with a fibrous reinforcing material such as glass fiber, ceramic fiber, or carbon fiber, or a powder-like reinforcing material such as glass powder or inorganic filler such as silica, alumina, or titanium oxide.

[0034] The sheath material is usually formed as a fiber assembly, and the fibers constituting it include one or more of natural fibers such as cotton, synthetic fibers such as polypropylene, polyester, nylon, aramid, and inorganic fibers such as glass fiber and carbon fiber, among which synthetic fibers such as polypropylene, polyester, nylon, and aramid, which have a heat resistance temperature of 130° C. or higher, are preferred. Such fiber assemblies are generally made of fiber materials such as braid, woven fabric, knitted fabric, felt, and nonwoven fabric. In this case, the fiber materials may be treated with a surfactant to adjust the liquid absorption speed, or the surface of the sheath material may be further coated with varnish or functionally treated such as hydrophilic treatment.

[0035] The absorbent wick for thermal evaporation thus obtained is applied to a liquid product in which the aqueous insecticide composition for thermal evaporation is heated and evaporated through the absorbent wick for thermal evaporation. That is, the aqueous insecticide composition for thermal evaporation is contained in a liquid medicine container, and the lower part of the absorbent wick for thermal evaporation is immersed in the aqueous insecticide composition for thermal evaporation through the inner plug. Then, the aqueous insecticide composition for thermal evaporation in the liquid medicine container is led to the upper part of the absorbent wick for thermal evaporation, heated to 60 to 130°C by a heating element provided at the upper part of the thermal evaporation device, and evaporated into the atmosphere. The absorbent wick for thermal evaporation faces the hollow cylindrical heat dissipation cylinder constituting the heating element with a gap provided therebetween, so that the desired surface temperature (for example, 60 to 130°C) of the upper part of the absorbent wick for thermal evaporation can be achieved by setting the temperature of the heating element higher than that (for example, 80 to 150°C). If the heating temperature of the aqueous insecticide composition for thermal evaporation becomes too high, the aqueous insecticide composition for thermal evaporation may evaporate early, or the aqueous insecticide composition for thermal evaporation may undergo thermal decomposition or polymerization, resulting in the formation of high-boiling-point substances on the surface of the liquid-absorbing wick for thermal evaporation, which may accumulate and cause clogging. On the other hand, if the heating temperature becomes too low, the aqueous insecticide composition for thermal evaporation becomes difficult to evaporate, and sufficient insecticidal performance cannot be achieved.

[0036] According to the study by the present inventors, it was found that the positional relationship between the upper part of the liquid absorbent wick for thermal evaporation (outer diameter: 6.7 to 7.3 mm) and the inner wall of the heat dissipation cylinder (inner diameter: 10 mm, height: 8 to 12 mm) facing the upper part also indirectly contributes to the intrusion prevention effect of the pest control product. That is, if the length of the upper part of the liquid absorbent wick for thermal evaporation facing the inner wall of the heat dissipation cylinder is a and the height of the inner wall of the heat dissipation cylinder is b, the ratio (a / b) can be changed by moving the upper part of the liquid absorbent wick for thermal evaporation up and down. In the pest control product according to the present invention, the above ratio (a / b) can be set in the range of 0.1 to 1.3. Here, when the ratio (a / b) exceeds 1.0, the upper part of the liquid absorbent wick for thermal evaporation protrudes from the upper end of the heat dissipation cylinder. In addition, when the ratio (a / b) exceeds 1.0, the amount of the pyrethroid insecticidal component evaporated per unit time increases. However, when there is no need to increase the amount of evaporation of the aqueous insecticide composition for thermal evaporation, it is preferable to set the ratio (a / b) to 0.2 to 0.8.

[0037] The heating and transpiration device used as a pest control product may be provided with various functions and members in accordance with conventional devices in addition to the heating element described above. A protective cap is placed on the top of the heating element for safety, and an opening is formed in the center of the cap. The size and shape of the cap are arbitrary as long as the aqueous insecticide composition for heating and transpiration does not condense or adhere excessively to the protective cap or the device. For example, it is effective to hang a cylindrical transpiration tube with an inner diameter of 10 to 30 mm from the vicinity of the opening. In this case, the distance between the lower end of the transpiration tube and the upper surface of the heating element is preferably within the range of 1 to 5 mm in terms of the heat resistance and transpiration performance of the transpiration tube. In addition, a power cord, an on / off switch, a pilot lamp, etc., which are connected to the heating element, may be appropriately provided.

[0038] According to the pest control method to which the present invention is applied, not only pyrethroid-susceptible strains, but also Culex pipiens quinquefasciatus, Culex tritaeniorhynchus, Culex pipiens molestus, and other Culex pipiens with reduced susceptibility, Aedes aegypti, Aedes albopictus, and other harmful flying insects such as house flies, moth flies, phorid flies, horseflies, black flies, and midges are not only practically insecticidal but also exhibit an effect of efficiently preventing the invasion of pests from outdoors into indoors, in living rooms, rooms, bedrooms, etc. In particular, the effect of preventing the invasion of mosquitoes is remarkably excellent, and therefore the method is extremely useful. EXAMPLES

[0039] Next, the effectiveness of the insecticidal efficacy enhancer, the pest control method, and the aqueous insecticidal composition for thermal evaporation of the present invention will be described with reference to examples.

[0040] Example 1 <Aqueous insecticide composition for thermal evaporation> An aqueous insecticide composition for thermal evaporation was prepared by mixing 0.9 mass% transfluthrin as a pyrethroid insecticidal ingredient, 40 mass% 1,2-hexanediol, a glycol compound as an insecticidal efficacy enhancer, 10 mass% 3-methoxy-3-methylbutanol (Solfite) as an aqueous organic compound, 0.1 mass% dibutylhydroxytoluene (BHT) as a stabilizer, and 49 mass% purified water.

[0041] <Liquid-absorbing wick for heating and evaporation> A mixture containing 52% by mass of mica powder as an inorganic powder, 33% by mass of clay powder as an inorganic binder, 10% by mass of graphite as an organic substance, 3% by mass of carboxymethylcellulose as an organic binder, and 2% by mass of starch was added with water and kneaded. The kneaded product was extruded under pressure, air-dried, and then fired at 1100°C to obtain a liquid-absorbing wick for thermal evaporation (round bar with a diameter of 7 mm and a length of 66 mm).

[0042] <Pest control products> 45 mL of the aqueous insecticide composition for thermal evaporation was placed in a plastic container, and a liquid-absorbent wick for thermal evaporation was loaded through an inner plug, and then the container was attached to a thermal evaporation device [for example, a thermal evaporation device described in Japanese Patent No. 2926172, in which a hollow cylindrical heat dissipation cylinder (inner diameter: 10 mm, height: 10 mm, surface temperature: 137°C) was installed around the upper part of the liquid-absorbent wick] to obtain the pest control product of Example 1. The length of the upper part of the liquid-absorbent wick for thermal evaporation facing the inner wall of the heat dissipation cylinder was 0.7 times the height of the inner wall of the heat dissipation cylinder.

[0043] <Verification test for pest control effect> The pest control product of Example 1 was applied to a 6 tatami room (25 m 3 ) and the electricity was turned on for 12 hours a day with one of the four sides facing the outdoors open. Over a period of 60 days (approximately 700 hours), no mosquitoes entered the house through the window and bit anyone.

[0044] [Examples 2 to 16, Comparative Examples 1 to 6] According to Example 1, an aqueous insecticide composition for thermal evaporation and an absorbent wick for thermal evaporation were prepared, and these were loaded into a thermal evaporation device to produce pest control products of Examples 2 to 16. Of these, the pest control products of Examples 2 to 15 were subjected to the measurements and tests (1) to (3) described below. In addition, the pest control products of Comparative Examples 1 to 6 prepared for comparison were also subjected to the same measurements and tests as in the Examples. The formulations of the aqueous insecticide composition for thermal evaporation and the composition of the absorbent wick for thermal evaporation in each Example and Comparative Example are shown in Tables 1 and 2. Table 1 also shows the formulation of the aqueous insecticide composition for thermal evaporation and the composition of the absorbent wick for thermal evaporation in Example 1.

[0045] Comparative Example 7 For comparison with the aqueous insecticide composition, an oil-based insecticide composition was prepared. Specifically, the aqueous insecticide composition for thermal evaporation of Comparative Example 1 was prepared without containing aqueous organic compounds (glycol compounds and glycol ether compounds), and kerosene was used instead of water to obtain an oil-based insecticide composition (oil-based insecticide composition for thermal evaporation). The liquid-absorbing wick for thermal evaporation used for evaporating the oil-based insecticide composition for thermal evaporation was a burnt wick of the same composition as in Comparative Example 1, which was loaded into a thermal evaporation device to obtain the pest control product of Comparative Example 7. The pest control product of Comparative Example 7 was also subjected to the same measurements and tests as in the examples.

[0046] [Table 1]

[0047] [Table 2]

[0048] (1) Transpiration performance 6 tatami room (25m 3 The test insect control product was placed in the center of the heating device and heated by electrical current. At the beginning of use (on the second day of use), the evaporated particles were trapped in a silica gel packed column at a position 1 m above the heating evaporation device, and the insecticidal components were extracted with acetone, after which the amount of the insecticidal components evaporated per unit time was determined by gas chromatographic analysis.

[0049] (2) Insecticidal efficacy test Plastic cylinders with an inner diameter of 20 cm and a height of 43 cm were stacked in two layers, and a cylinder with an inner diameter of 20 cm and a height of 20 cm (where the test insects were placed) was placed on top of them with a 16-mesh wire netting between them, and on top of that was a partition of the same 16-mesh wire netting, and on top of that was a cylinder of the same diameter and height of 20 cm. These four stacked cylinders were placed on a disk placed on a stand with a rubber packing between them. There was a 5 cm circular hole in the center of the disk, and the test pest control product was placed on this hole and heated by applying electricity. After 3 hours of applying electricity, about 20 adult female test insects, Culex pipiens mosquitoes, were released into the third upper cylinder. The number of test insects that fell and turned over over time was counted, and the KT50 The values ​​were calculated. After 20 minutes of exposure, all test insects were collected and their mortality was examined 24 hours later. The insecticidal efficacy test was carried out at the beginning of use (2 days after use) and at the end of use (several days before the expiration date).

[0050] (3) Intrusion prevention rate A window was provided at the boundary between two adjacent 10 tatami mat rooms, and everything except the window was sealed. The test pest control product was placed in one of the rooms, and the observer remained in the room while heating it with electricity was applied to create a drug-treated area. 100 test insects, adult female Culex pipiens mosquitoes, were released into the adjacent drug-free insect release area, and the number of test insects that invaded the drug-treated area from the drug-free insect release area through the window was observed for 60 minutes. In addition, in order to set a standard for evaluating the effectiveness, a test was similarly conducted in which no pest control product was used as an untreated control area. The intrusion prevention test was conducted twice, at the beginning of use of the test pest control product (the second day of use) and at the end of use (several days before the expiration date). The test was also conducted twice for the untreated control area, the average number of invaded insects was calculated, and the intrusion prevention rate was calculated using the following formula. Intrusion prevention rate (%) = (CT) / C × 100 C: Average number of invading insects (individuals) in 60 minutes in the untreated control area T: Average number of insects invading the drug-treated area for 60 minutes (individuals)

[0051] Table 3 shows the measurement and test results for each of the examples and comparative examples.

[0052] [Table 3]

[0053] From the results of Tables 1 to 3, it was confirmed that the pest control products (Examples 1 to 15) using the aqueous insecticide composition for thermal evaporation containing the insecticidal efficacy enhancer of the present invention showed stable evaporation performance similar to that of the conventional product (Comparative Example 1) containing only a glycol ether compound as an aqueous organic compound, while exhibiting excellent enhancing effects in terms of insecticidal efficacy. In particular, a remarkable enhancing effect was observed in the knockdown effect and the invasion prevention effect. In addition, when comparing the transfluthrin formulation (Example 1), metofluthrin formulation (Example 3), profluthrin formulation (Example 4), heptafluthrin formulation (Example 5), and meperfluthrin formulation (Example 10), even though the formulations showed almost the same efficacy in terms of lethal activity, the transfluthrin formulation had a high knockdown effect and was specifically superior in terms of the invasion prevention effect. Furthermore, a comparison between Example 12, Example 13, and Comparative Example 1 showed that when the aqueous organic compound used in the aqueous insecticide composition for thermal evaporation was composed of 20 mass % or more of a glycol-based compound, the knockdown effect and the invasion prevention effect tended to be enhanced, which was preferable.

[0054] On the other hand, the aqueous organic compounds contained in the aqueous insecticide composition for thermal evaporation, including 1,6-hexanediol (Comparative Example 2) in which the two carbon atoms having hydroxyl groups are not adjacent, 1,2-propanediol (Comparative Example 3) in which the carbon number is 3, and 1,2-decanediol (Comparative Example 4) in which the carbon number is 10, were not observed to enhance the insecticidal effect, even though they are glycol compounds. In this way, the insecticidal efficacy enhancing effect specific to the present invention was a completely unexpected result, in contrast to the fact that 1,2-hexanediol showed a volatilization adjusting effect on the same level as 1,6-hexanediol and 1,2-propanediol in Patent Document 2. In addition, in the case of d,d-T80-prallethrin (Comparative Examples 5 and 6) in which the vapor pressure of the pyrethroid insecticidal component is outside the range of the present invention, the insecticidal efficacy enhancing effect seen in 1,2-hexanediol was not observed, and it was confirmed that the efficacy enhancing effect specific to the present invention is an extremely heterogeneous effect that is expressed only when combined with a pyrethroid insecticidal component in a specific vapor pressure range. Furthermore, even when an oil-based formulation was used instead of an aqueous formulation (Comparative Example 7), a sufficient insecticidal effect was not obtained. [Industrial Applicability]

[0055] The present invention can be used as a pest control product for humans and pets, but can also be used for other purposes, such as killing mites, killing germs, preventing bacteria, and deodorizing and preventing odors.

Claims

1. An insecticidal efficacy enhancer comprising as an active ingredient a glycol compound in which one hydroxyl group is bonded to each of two adjacent carbon atoms of an alkane having 4 to 7 carbon atoms, The present invention relates to an aqueous insecticide composition for thermal evaporation, the composition containing transfluthrin as a pyrethroid insecticidal ingredient, the composition being absorbed into an absorbent wick for thermal evaporation, and the composition being effective in preventing flying pests from invading indoors. The composition is formulated so that the amount of the glycol compound is 6 to 60% by mass. The glycol compound is at least one selected from the group consisting of 1,2-butanediol, 1,2-pentanediol, and 1,2-hexanediol.

2. The aqueous insecticide composition for thermal evaporation contains the pyrethroid insecticidal component, an aqueous organic compound, and water, 2. The insecticidal efficacy enhancer according to claim 1, wherein the aqueous organic compound is composed of 20% by mass or more of the glycol-based compound.

3. The insecticidal efficacy enhancer according to claim 2 , wherein the aqueous organic compound further contains a glycol ether compound.

4. The insecticidal efficacy enhancer according to claim 3, wherein the glycol ether compound is at least one selected from the group consisting of diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, and 3-methoxy-3-methylbutanol.

5. A method for controlling pests using a liquid-absorbing wick for thermal evaporation, comprising: A step of immersing a lower portion of the liquid-absorbing wick for thermal evaporation in an aqueous insecticide composition for thermal evaporation containing an insecticidal efficacy enhancer according to any one of claims 1 to 4; a step of guiding the aqueous insecticide composition for thermal evaporation absorbed from the lower part of the liquid-absorbing wick for thermal evaporation to the upper part of the liquid-absorbing wick for thermal evaporation and heating the aqueous insecticide composition at 80 to 150° C., thereby evaporating the pyrethroid insecticidal component into the atmosphere; A pest control method comprising the steps of:

6. An aqueous insecticide composition for thermal evaporation that is absorbed into a liquid-absorbing wick for thermal evaporation, comprising: The insecticide contains transfluthrin as a pyrethroid insecticidal ingredient and an insecticidal efficacy enhancer having as its active ingredient a glycol compound in which one hydroxyl group is bonded to each of two adjacent carbon atoms of an alkane having 4 to 7 carbon atoms, The blending amount of the glycol compound is 6 to 60 mass %, The glycol compound is at least one selected from the group consisting of 1,2-butanediol, 1,2-pentanediol, and 1,2-hexanediol; An aqueous insecticide composition for thermal evaporation, which has an effect of preventing flying pests from invading indoors.

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