JP7664969B2 - Aerosol for controlling mosquitoes and method for controlling mosquitoes - Google Patents

Description

The present invention relates to an aerosol for mosquito control, which comprises a pressure-resistant container equipped with a constant-volume injection valve that contains an aerosol concentrate containing a pest control component and an organic solvent, and a propellant, and a spray button equipped with an injection port connected to the constant-volume injection valve, and a mosquito control method using the same.

Methods for exterminating flying pests include, for example, evaporating the insecticide from a carrier impregnated with the insecticide into the treatment space, spraying the insecticide directly onto the flying pests, and spraying the insecticide in advance in places where flying pests are likely to appear. With regard to these methods, aerosol insecticides containing insecticidal ingredients have been developed as products for exterminating flying pests that invade indoors. Aerosol insecticides are widely used as easy-to-use products because the insecticidal ingredients can be easily sprayed into the treatment space.

Conventionally, there have been aerosol insecticides that suppress the decrease in the residual rate of the insecticide in the air indoors (see, for example, Patent Document 1). According to Patent Document 1, after the insecticide is released, it remains in the air and suppresses the decrease in the airborne concentration, so that it is possible to maintain a sufficient extermination effect against mosquitoes hiding in the shadows.

There is also an aerosol insecticide in which the particle size when sprayed indoors is set to be larger than that of Patent Document 1 (see, for example, Patent Document 2). Patent Document 2 is an aerosol insecticide based on the same technical concept as Patent Document 1, and aims to leave the insecticide in the air indoors for as long as possible, thereby increasing its effectiveness against mosquitoes.

On the other hand, there is a method for exterminating flying pests in a house, characterized in that an aerosol insecticide is attached to the surface of an indoor structure or fixture (see, for example, Patent Document 3). According to Patent Document 3, a specific compound attached to an indoor structure etc. evaporates, so that flying pests in a house can be efficiently exterminated by a simple means without the need for repeated spraying or continuous operation of an electric appliance etc.

JP 2001-17055 A JP 2013-99336 A JP 2001-328913 A

The aerosol insecticide in Patent Document 1 attempts to increase the time the insecticide remains in the air by adjusting the particle size of the insecticide that diffuses indoors, thereby lengthening the duration of the insecticide. However, the rate of insecticide particles remaining in the air 12 hours or more after the start of treatment is 0.5% or more, and the aerosol insecticide in Patent Document 1, which aims to maintain the rate of insecticide particles remaining in the air, has a limited duration. In Patent Document 2, the rate of insecticide particles remaining in the air is the same as in Patent Document 1, and it is not an aerosol insecticide that can be expected to last for a long time.

Of the mosquitoes targeted for control (which includes not only ordinary mosquitoes such as Culex pipiens and Aedes albopictus, but also chironomids and moth flies belonging to the suborder Culicidae), Culex pipiens and Aedes albopictus in particular are mosquitoes that not only suck blood but also transmit infectious diseases, making it necessary to protect oneself from these mosquitoes and creating a demand for more effective extermination methods than ever before. Mosquitoes are flying pests that invade indoors at any time of the day or night, so an insecticide that is effective all day, in other words, lasts for 24 hours, is ideal.

However, as mentioned above, the aerosol insecticides disclosed in Patent Documents 1 and 2 are only effective for about 12 hours. In addition, Patent Documents 1 and 2 actively allow the insecticide to remain in the air by adjusting the particle size of the insecticide, but the fact that the insecticide particles remain in the air means that people and pets in the treatment space are in an environment where they inhale the insecticide for a long period of time. Therefore, it is difficult to say that these aerosol insecticides are preferable in terms of their effects on the human body and pets.

It is unclear whether the extermination method of Patent Document 3 can maintain a stable effect over a long period of time. It is believed that the drug particles sprayed into the air follow one of the following behaviors: (A) remain suspended in the air, (B) adhere to the floor or wall, (C) volatilize again after (B), or (D) decompose and disappear due to exposure to light, etc. In light of these, the extermination method of Patent Document 3 falls into type (C). However, when the drug that has adhered to indoor structures etc. volatilizes back into the air, it is easily affected by temperature, air volume, etc., so the extermination method of Patent Document 3 does not necessarily provide a stable effect in exterminating flying pests.

The present invention was made in consideration of the above problems, and aims to provide a mosquito control aerosol that can exert an excellent control effect against flying pests, particularly mosquitoes, for a long period of time and that reduces the impact on the human body and pets, and a mosquito control method that uses the mosquito control aerosol.

The characteristic configuration of the mosquito control aerosol according to the present invention for solving the above problems is as follows:
a pressure-resistant container provided with a metered-dose injection valve that contains an aerosol concentrate containing a pest control component and an organic solvent and a propellant;
an injection button provided with an injection port connected to the metered injection valve;
A mosquito control aerosol comprising:
The ejection volume when the ejection button is pressed once is adjusted to 0.1 to 0.4 mL, and the ejection force at an ejection distance of 20 cm is adjusted to 0.3 to 10.0 gf at 25°C.
The aerosol concentrate is sprayed from the spray nozzle as adhesive particles, at least a portion of which adheres to the exposed portion within the processing space.

As described in "Problems to be Solved by the Invention," conventional aerosol insecticides have been developed to actively disperse drug particles in the treatment space and to prolong the time they remain in the air as much as possible. However, if the retention time of drug particles suspended in the treatment space is long, there is a possibility that people or pets may inhale the drug particles if they enter the treatment space, which may have an adverse effect on their health.
However, the inventors' research has revealed that mosquitoes, such as mosquitoes (hereinafter, in the present invention, simply referred to as "mosquitoes"), spend more time resting on walls than flying. In other words, most of the mosquitoes that invade indoors stay on walls and wait for an opportunity to suck human blood. For this reason, the conventional method of prolonging the time that drug particles in the treatment space are suspended can have a certain effect on controlling flying mosquitoes, but the drug cannot be fully effective on mosquitoes resting on walls, and as a result, mosquito control may be incomplete. Based on the above research results, the inventors thought that improving the control effect on mosquitoes resting on walls would lead to improved control of all mosquitoes that invade indoors while suppressing people and pets from inhaling the drug.
Therefore, in the mosquito control aerosol according to the present invention, at least a part of the aerosol concentrate sprayed into the treatment space is formed as adhesive particles that adhere to exposed areas in the treatment space (for example, floors, walls, surfaces of structures such as furniture, etc., present in the treatment space). Therefore, both mosquitoes that are resting on exposed areas and mosquitoes that are flying in the treatment space can be effectively knocked down or killed, and the overall mosquito control effect can be improved. In addition, even if particles other than the adhesive particles (hereinafter referred to as "floating particles") are evenly dispersed throughout the treatment space, the concentration of the aerosol concentrate in the treatment space is reduced by the amount of the adhesive particles. Therefore, the amount of particles of the aerosol concentrate inhaled by people or pets in the treatment space is extremely small, making the mosquito control aerosol safer for humans and pets.
Moreover, the mosquito control aerosol according to the present invention is adjusted so that the spray volume when the spray button is pressed once is 0.1 to 0.4 mL, and the spray force at a spray distance of 20 cm is 0.3 to 10.0 g·f at 25° C. By adjusting the spray volume and spray force in this manner, at least a portion of the sprayed aerosol concentrate can be formed as adhesive particles, and an excellent control effect against mosquitoes can be achieved.

In the aerosol for mosquito control according to the present invention,
The adhesive particles preferably have a 90% particle size of 20 to 80 μm in a volume cumulative distribution at 25° C. and a spray distance of 15 cm.

By adjusting the adhesive particles to the above-mentioned optimal range, the mosquito control aerosol of this composition can reliably knock down or kill mosquitoes that are resting on exposed areas with the pest control components of the adhesive particles.

In the aerosol for mosquito control according to the present invention,
The amount of the adhesive particles attached to the exposed portion in the treatment space is preferably 0.01 to 0.4 mg per ^{square meter} .

With this mosquito control aerosol, by adjusting the amount of adhesive particles to the above-mentioned optimal range, mosquitoes resting on exposed areas can be reliably knocked down or killed by the pest control components of the adhesive particles.

In the aerosol for mosquito control according to the present invention,
The volume ratio (a/b) of the aerosol concentrate (a) to the propellant (b) contained in the pressure-resistant container is preferably 10/90 to 50/50.

When the volume ratio (a/b) of the aerosol concentrate (a) and the propellant (b) of the mosquito control aerosol of this configuration is within the above-mentioned range, the adhesive particles formed from the sprayed aerosol concentrate are in an optimal state. This allows the adhesive particles to reliably reach exposed areas in the treatment space, and allows the floating particles to float in the treatment space in an amount that does not affect the human body or pets.

In the aerosol for mosquito control according to the present invention,
The organic solvent is preferably at least one selected from the group consisting of higher fatty acid esters and alcohols.

According to the mosquito control aerosol of this configuration, the organic solvent is at least one selected from the group consisting of higher fatty acid esters and alcohols. By using such an organic solvent, the effects of each component can be efficiently exerted. In addition, when the aerosol concentrate is sprayed, adhesive particles can be formed in a well-balanced manner, and the control effect against mosquitoes is stable.

In the aerosol for mosquito control according to the present invention,
The pest control component preferably has a vapor pressure at 30° C. of 2×10 ⁻⁴ to 1×10 ⁻² mmHg.

In the mosquito control aerosol of this configuration, the pest control component has a vapor pressure of 2×10 ⁻⁴ to 1×10 ⁻² mmHg at 30° C. Such a pest control component can form adhesive particles in an optimal state when the aerosol concentrate is sprayed. Furthermore, when the aerosol is prepared with components other than the pest control component, the organic solvent, and the propellant, an effective mosquito control aerosol can be realized.

In the aerosol for mosquito control according to the present invention,
When the aerosol concentrate is sprayed once into the treatment space, the duration of effect of the pest control component is preferably 20 hours or more for a space of 33 ^m3 or less.

In the methods for exterminating mosquitoes using aerosol insecticides disclosed in Patent Documents 1 and 2, the duration of the effect of the agent is set to 12 hours. However, with the aerosol for mosquito control according to the present invention, the pest control effect can be sustained for 20 hours or more in a space of 33 ^m3 or less, i.e., for almost a whole day, by spraying the aerosol concentrate just once into the treatment space.

In the aerosol for mosquito control according to the present invention,
The nozzle preferably has a diameter of 0.2 to 1.0 mm.

With this mosquito control aerosol, the nozzle diameter is set within the above-mentioned optimal range, so the particle diameter and spray force of the aerosol concentrate can be appropriately adjusted, and adhesive particles can be formed in an optimal state. As a result, the effect of the pest control ingredient can be fully achieved.

The characteristic configuration of the mosquito control method according to the present invention for solving the above problems is as follows:
The object of the present invention is to use any one of the above-mentioned mosquito control aerosols to inject the aerosol concentrate into a treatment space to knock down or kill mosquitoes.

The mosquito control method of this configuration is carried out using the mosquito control aerosol of the present invention, and therefore can achieve the same excellent mosquito control effect as the mosquito control aerosol described above.

In the mosquito control method according to the present invention,
It is preferable that the aerosol concentrate is sprayed into the treatment space once every 24 hours.

As described above, the mosquito control aerosol according to the present invention has a duration of effect of the pest control component of 20 hours or more, approximately one day. Therefore, using this mosquito control aerosol, the aerosol concentrate can be sprayed into the treatment space once every 24 hours. By carrying out such a mosquito control method, the pest control effect can be sustained throughout the day by simply spraying once a day at a fixed time.

FIG. 1 is a model diagram showing the behavior of particles of an aerosol concentrate when the aerosol concentrate is sprayed into a treatment space.

The mosquito control aerosol of the present invention comprises a pressure-resistant container equipped with a constant-dose injection valve that contains an aerosol concentrate containing a pest control component and an organic solvent, and a propellant, and an injection button equipped with an injection port connected to the constant-dose injection valve. The mosquito control aerosol of the present invention will be described below. However, the present invention is not intended to be limited to the configurations shown in the embodiments and drawings described below.

<Aerosol concentrate>
[Pest control ingredient]
The pest control component, which is one of the main components of the aerosol concentrate, has a vapor pressure of 2×10 ⁻⁴ to 1×10 ⁻² mmHg at 30° C. Metofluthrin, transfluthrin, etc. are preferably selected as such a pest control component. These pest control components can be used alone or in a mixed state. Note that metofluthrin and transfluthrin have optical isomers and geometric isomers based on asymmetric carbons, and these are also included in the present invention.

The content of the pest control component in the aerosol concentrate is preferably 1.0 to 50% by weight, taking into consideration that the pest control component is dissolved in an organic solvent and then sprayed into the treatment space. In this range, the pest control component is easily dissolved in the organic solvent, and when the aerosol concentrate is sprayed, at least a portion of the pest control component is formed as adhesive particles, and the particles other than the adhesive particles are easily formed as floating particles (adhesive particles and floating particles will be described in detail later). If the content of the pest control component in the aerosol concentrate is less than 1.0% by weight, the pest control component cannot be effectively exerted, and the mosquito control effect is insufficient. On the other hand, if the content of the pest control component in the aerosol concentrate exceeds 50% by weight, the concentration of the pest control component becomes high, making it difficult to properly prepare the aerosol concentrate.

As described above, the pest control component contained in the mosquito control aerosol of the present invention is preferably one having a vapor pressure of 2 x 10 ^-4 to 1 x 10 ^-2 mmHg at 30°C (e.g., metofluthrin, transfluthrin), but in addition to these components, it is also possible to contain pyrethroid compounds such as profluthrin and empenthrin, other pyrethroid compounds such as phthalthrin, resmethrin, cyfluthrin, fenothrin, permethrin, cyphenothrin, cypermethrin, allethrin, prallethrin, furamethrin, imiprothrin, and etofenprox, silicon compounds such as silafluofen, organophosphorus compounds such as dichlorvos and fenitrothion, and carbamate compounds such as propoxur.

The pest control component is adjusted so that when the aerosol concentrate is sprayed once into the treatment space, the residual rate in the air (in the treatment space) after 2 hours is 0.05 to 5%. The residual rate in the air is expressed as the ratio of the number of particles (Q) present in the treatment space after a predetermined time to the number of particles (P) present in the treatment space immediately after spraying, that is, Q/P x 100 (%), but it can be calculated simply from the theoretical concentration of the pest control component in the air and the concentration of the pest control component in the air after a predetermined time has passed, as described in the examples below. The amount of the pest control component sprayed at this time is adjusted to 5.0 to 30 mg per 4.5 to 8 tatami mats (approximately 18.5 to 33.0 ^{m 3} ). Within this range, the aerosol concentrate forms adhesive particles in an optimal state, and the pest control effect can be exerted. In addition, even if the residual rate is relatively low as described above, it can effectively knock down or kill mosquitoes. Furthermore, even if people or pets in the treatment space inhale the gas, there is no risk of adverse effects on the human body or pets, and the gas can be used safely.

[Organic solvents]
The organic solvent, which is another main component of the aerosol concentrate, can dissolve the above-mentioned pest control components to prepare the aerosol concentrate, and can form optimal particles when the prepared aerosol concentrate is sprayed into the treatment space. As the organic solvent, higher fatty acid esters and alcohols are preferred. As the higher fatty acid esters, those having a total carbon number of 16 to 20 are preferred, and examples thereof include isopropyl myristate, butyl myristate, hexyl laurate, and isopropyl palmitate. Of these, isopropyl myristate is particularly preferred. As the alcohols, lower alcohols having 2 to 3 carbon atoms are preferred. As the organic solvent, for example, hydrocarbon solvents such as n-paraffin and isoparaffin, glycol ethers having 3 to 6 carbon atoms, and ketone solvents can also be mixed.

[Other ingredients]
In addition to the above-mentioned components, the mosquito control aerosol of the present invention may also be appropriately blended with acaricides, fungicides for molds and fungi, antibacterial agents, bactericides, fragrances, deodorants, stabilizers, antistatic agents, antifoaming agents, excipients, etc. Examples of acaricides include 5-chloro-2-trifluoromethanesulfonamido methyl benzoate, phenyl salicylate, 3-iodo-2-propynyl butylcarbamate, etc. Examples of fungicides, antibacterial agents, and bactericides include hinokitiol, 2-mercaptobenzothiazole, 2-(4-thiazolyl)benzimidazole, 5-chloro-2-methyl-4-isothiazolin-3-one, triforine, 3-methyl-4-isopropylphenol, ortho-phenylphenol, etc. Examples of fragrances include orange oil, lemon oil, lavender oil, peppermint oil, eucalyptus oil, citronella oil, lime oil, yuzu oil, jasmine oil, cypress oil, green tea essential oil, limonene, α-pinene, linalool, geraniol, phenylethyl alcohol, amylcinnamic aldehyde, cuminaldehyde, benzyl acetate, and other aromatic components, as well as fragrance components containing leaf alcohol and leaf aldehyde, known as the "scent of greenery."

<Propellant>
Examples of propellants used in the mosquito control aerosol of the present invention include liquefied petroleum gas (LPG), dimethyl ether (DME), nitrogen gas, carbon dioxide gas, nitrous oxide, compressed air, etc. The above propellants can be used alone or in a mixed state, but those containing LPG as the main component are easy to use.

The mosquito control aerosol of the present invention is adjusted so that the volume ratio (a/b) of the aerosol concentrate (a) and the propellant (b) is 10/90 to 50/50. By adjusting to such a range, at least a part of the aerosol concentrate can be formed as adhesive particles. This allows the adhesive particles to reliably reach the exposed parts in the treatment space, and the floating particles can float in the treatment space in an amount that does not affect the human body or pets. In this way, the adhesive particles are present in an optimal state, and the pest control effect can be maximized. If the ratio of the propellant (b) is increased relative to the volume ratio (a/b) of 10/90, that is, if a large amount of propellant is enclosed in the pressure-resistant container, the sprayed aerosol concentrate is finer than necessary, and the adhesive particles are reduced. As a result, there is a shortage of adhesive particles that adhere to the exposed parts in the treatment space, and mosquitoes that are resting on the exposed parts may not be reliably controlled. On the other hand, when the volume ratio (a/b) is 50/50 and the proportion of propellant (b) is reduced, that is, when the amount of propellant enclosed in the pressure-resistant container is reduced, it becomes difficult to form the sprayed aerosol concentrate into adhesive particles having particle sizes in the above-mentioned optimal range, and the aerosol concentrate settles immediately after being sprayed. As a result, the amount of adhesive particles that adhere to the exposed parts in the treatment space becomes insufficient, making it difficult to knock down or kill mosquitoes quickly.

<Mosquito control aerosol>
As described above, the pest control component, organic solvent, propellant, and other components to be blended as necessary are selected and sealed in a pressure-resistant container to complete an aerosol product. This aerosol product is the mosquito control aerosol of the present invention, which sprays an aerosol concentrate into a treatment space. The aerosol concentrate is mainly composed of a pest control component and an organic solvent, and is strictly speaking different from the propellant. However, since the aerosol concentrate is released to the outside of the pressure-resistant container at the same time as the propellant, the aerosol contents including the aerosol concentrate and the propellant may be treated as the "aerosol concentrate" in the following description. Here, the injection valve provided in the mosquito control aerosol of the present invention will be described. The mosquito control aerosol of the present invention is mainly composed of a pressure-resistant container (aerosol container), a metered injection valve, and an injection button. The metered injection valve is connected to an injection button, which is an operating unit for injecting the aerosol concentrate, and the injection button is provided with an injection port through which the aerosol concentrate is sprayed from the aerosol container to the outside (treatment space).

When the spray button of the mosquito control aerosol is pressed once, the pressure of the propellant operates the constant-volume spray valve, and the aerosol concentrate in the pressure-resistant container rises to the spray nozzle and is sprayed into the treatment space. The spray volume of the aerosol concentrate at this time is adjusted to 0.1 to 0.4 mL, and more preferably 0.2 to 0.4 mL. Within this range, at least a part of the aerosol concentrate is formed as adhesive particles. If the spray volume is less than 0.1 mL, the spray volume is too small, so the adhesive particles do not sufficiently adhere to the exposed parts in the treatment space, making it difficult to knock down or kill mosquitoes that are resting on the exposed parts. In addition, the number of floating particles is also reduced, making it difficult to knock down or kill mosquitoes flying in the treatment space. On the other hand, if the spray volume exceeds 0.4 mL, more aerosol concentrate is released into the treatment space than necessary, making it difficult for people and pets to enter the treatment space, and the amount of aerosol concentrate used is also excessive, which is economically disadvantageous.

The mosquito control aerosol is adjusted so that the spray force at a point 20 cm away from the nozzle is 0.3 to 10.0 g·f at 25°C. Within this range, the adhesive particles formed from the aerosol concentrate can be smoothly delivered to the exposed parts in the treatment space with one spray, and the pest control component can exert its effect. Furthermore, the nozzle diameter of the nozzle is preferably set to 0.2 to 1.0 mm. Within this range, the above particle diameter and spray force can be appropriately adjusted, and at least a portion of the aerosol concentrate sprayed into the treatment space is optimally formed as adhesive particles, exerting a pest control effect and reliably knocking down or killing mosquitoes in the treatment space.

Fig. 1 is a model diagram showing the behavior of particles of an aerosol concentrate when the aerosol concentrate is sprayed into a treatment space. Fig. 1(a) is a model diagram showing the behavior of particles of an aerosol concentrate when the aerosol concentrate is sprayed into a treatment space according to a conventional product, and Fig. 1(b) is a model diagram showing the behavior of particles of an aerosol concentrate when the aerosol concentrate is sprayed into a treatment space according to the present invention.
As shown in FIG. 1(a), when the aerosol concentrate is sprayed into the treatment space, the conventional aerosol product for mosquito control (simply referred to as the "conventional product") becomes particles M with a particle diameter of less than 20 μm and spreads throughout the treatment space. After a while from the spray, the particles M further spread throughout the treatment space and the pest control component volatilizes. This makes it possible to knock down or kill mosquitoes flying in the treatment space. However, as described above, mosquitoes spend more time staying on exposed parts in the treatment space than they fly, so conventional products cannot reliably knock down or kill mosquitoes staying on exposed parts in the treatment space. In addition, when wind blows in by opening a window in the treatment space, some of the particles M floating in the treatment space are carried away by the wind, and the effect of the pest control component is greatly reduced. Furthermore, if the particles M remain floating in the treatment space for a long time, the amount of particles M inhaled by people and pets in the treatment space increases, which may have a negative effect on the human body and pets.
Therefore, the present inventors have developed an aerosol product for mosquito control that solves these problems after extensive research. The adhesive particles and floating particles, which are characteristic components of the aerosol product for mosquito control according to the present invention, will be described below.

[Adhesive particles]
As shown in FIG. 1(b), when the aerosol concentrate is sprayed once into the treatment space, adhesive particles X and floating particles Y are formed. In FIG. 1(b), the white circles indicate adhesive particles X, and the black circles indicate floating particles Y. The particle diameters of the two are different, and the adhesive particles X are formed with a larger particle diameter than the floating particles Y. The preferred particle diameter of the adhesive particles X is 20 to 80 μm in terms of 90% particle diameter in the volume cumulative distribution at 25° C. and a spray distance of 15 cm. If the particle diameter is within this range, when the aerosol concentrate is sprayed into the treatment space, it can move quickly to the exposed part in the treatment space and adhere thereto. Therefore, the mosquitoes that are resting on the exposed part can be knocked down or killed by the pest control component of the adhesive particles X. In addition, the pest control effect is exerted on mosquitoes that have entered the treatment space and are trying to rest on the exposed part, so that it is also possible to drive them out of the treatment space. If the particle size is less than 20 μm, the particle size is too small and it is difficult to reach the exposed area, and as a result, it is difficult to control mosquitoes that are resting or about to rest on the exposed area. On the other hand, if the particle size exceeds 80 μm, the particle size is too large and it is difficult to control the behavior of the adhesive particles, and it is difficult to properly attach them to the exposed area. A more preferable particle size of the adhesive particles X is a 90% particle size of 25 to 70 μm in the volume cumulative distribution at 25° C. and a spray distance of 15 cm.

The preferred amount of the adhesive particles X attached to the exposed portion in the treatment space is 0.01 to 0.4 mg per ^m2 , preferably 0.05 to 0.2 mg per ^m2 . Within this range, mosquitoes resting on the exposed portion can be effectively knocked down or killed. If the amount is less than 0.01 mg per ^m2 , sufficient control effect cannot be achieved against mosquitoes resting on the exposed portion, making it difficult to knock down or kill the mosquitoes. On the other hand, if the amount of attachment exceeds 0.4 mg per ^m2 , the pest control effect is not significantly improved, and the amount of the aerosol concentrate used is excessive, which is economically disadvantageous.

[Suspended particles]
The preferred particle diameter of the buoyant particles Y is less than 20 μm in terms of the 90% particle diameter in the volume cumulative distribution at 25° C. and a spray distance of 15 cm. In this range, when the aerosol concentrate is sprayed into the treatment space, it can be quickly diffused and floated in the treatment space. Therefore, the pest control component of the buoyant particles Y can knock down or kill mosquitoes flying in the treatment space. In addition, it is also effective against mosquitoes that try to invade the treatment space, so it is possible to suppress their intrusion into the treatment space. When the particle diameter of the buoyant particles Y is 20 μm or more, they function as adhesive particles X. In this way, by adjusting the particle diameter of some particles of the aerosol concentrate to the above-mentioned optimal range as the buoyant particles Y, they behave differently from the adhesive particles X, and can effectively knock down or kill mosquitoes together with the adhesive particles X.

As shown in FIG. 1(b), immediately after the aerosol concentrate is sprayed once into the treatment space, the adhesive particles X and the floating particles Y described above move quickly toward the exposed part in the treatment space, and the floating particles Y begin to diffuse throughout the treatment space. After a while from the first spray, the adhesive particles X complete their adhesion to the exposed part and maintain their adhered state. As described above, the mosquitoes that are resting on the exposed part are knocked down or killed by the pest control component. On the other hand, the floating particles Y are diffused evenly throughout the treatment space, and the pest control component gradually volatilizes, knocking down or killing the mosquitoes flying in the treatment space. In addition, it is possible to prevent the intrusion of mosquitoes that are trying to enter the treatment space. Even if a mosquito does invade the treatment space, if the mosquito stops on the exposed part in the treatment space or approaches the exposed part, it can be reliably knocked down or killed by the pest control component of the adhesive particles X that is attached to the exposed part. In this way, the mosquito control aerosol according to the present invention has two types of particles formed from the sprayed aerosol concentrate that behave differently, so that each type of particle exists in an optimal state and can maximize its pest control effect by sharing its respective roles. Therefore, the adhesive particles X and the floating particles Y provide an excellent control effect against both mosquitoes that are present in the treatment space and those that are attempting to enter the treatment space, and can knock down or kill them.

In addition, when wind blows into the treatment space, even if some of the buoyant particles Y are blown away by the wind, the adhesive particles X remain in the exposed portion. As described above, most of the mosquitoes in the treatment space spend more time remaining in the exposed portion, so if the adhesive particles X can exert the desired effect, there is no need to worry about a decrease in the mosquito control effect even if the amount of buoyant particles Y is reduced. Furthermore, as in the conventional product, some of the particles formed by the aerosol concentrate sprayed into the treatment space are formed as buoyant particles Y. Therefore, the concentration of the aerosol concentrate (buoyant particles Y) diffused in the treatment space is reduced by the amount of the adhesive particles X, so the concentration in the treatment space is lower than that of the conventional product. Therefore, the impact on the human body and pets caused by inhalation of the buoyant particles Y is reduced, and the product can be provided as a safe product.

When the aerosol concentrate prepared above is sprayed once into the treatment space, the duration of the effect of the pest control ingredient is 20 hours or more in a space of 33 ^m3 or less. Spaces of 33 ^m3 or less include living rooms of 4.5 to 8 tatami mats (ceiling height 2.5 m). Therefore, the mosquito control aerosol according to the present invention can maintain the pest control effect for almost a whole day in a normal living space such as a general house. Mosquitoes invade indoors regardless of day or night, and it is particularly necessary to prevent them from sucking blood while sleeping. Since the effect of the pest control ingredient lasts for 20 hours or more in a space of 33 ^m3 or less, for example, if it is sprayed once before going to bed at night, the effect will last until the afternoon of the next day, allowing you to sleep in peace.

<Mosquito control methods>
The mosquito control method of this configuration is carried out using the above-mentioned mosquito control aerosol. First, in a pressure-resistant container provided with a constant-volume injection valve containing an aerosol concentrate containing a pest control component and an organic solvent, and a propellant, when a spray button provided with an injection port connected to the constant-volume injection valve is pressed once, the aerosol concentrate is sprayed from the injection port into the treatment space (spraying step). At this time, as shown in FIG. 1(b), adhesive particles X and floating particles Y are formed from the aerosol concentrate and sprayed into the treatment space. The adhesive particles X adhere to the exposed parts in the treatment space, and the floating particles Y float in the treatment space. The adhesive particles X knock down or kill mosquitoes that are resting on the surfaces of walls, floors, structures, etc. in the treatment space, or are effective against mosquitoes that are trying to rest in these places, driving them out of the treatment space. On the other hand, the floating particles Y can knock down or kill mosquitoes flying in the treatment space, and are also effective against mosquitoes that attempt to invade the treatment space, suppressing their intrusion into the treatment space. The pest control effect of the adhesive particles X and the floating particles Y as described above lasts for a long period of time, for example, 20 hours or more in a space of 33 ^m3 or less. After a predetermined time has passed, the aerosol concentrate can be sprayed again into the treatment space to knock down or kill the mosquitoes.

As described above, the mosquito control aerosol according to the present invention has a duration of effect of the pest control component for 20 hours or more in a space of 33 ^m3 or less, which is approximately one day. Therefore, in a mosquito control method carried out using this mosquito control aerosol, the operation can be completed simply by carrying out the spraying step of spraying once a day at a fixed time every day. In this way, anyone can easily spray the aerosol concentrate into the treatment space, and it is possible to prevent missing the timing of the spraying.

In order to confirm the mosquito control effect of the mosquito control aerosol of the present invention, multiple mosquito control aerosols (Examples 1 to 10) having the characteristic configuration of the present invention were prepared and a mosquito control effect confirmation test was conducted. In addition, for comparison, mosquito control aerosols not having the characteristic configuration of the present invention (Comparative Examples 1 and 2) were prepared and a similar mosquito control effect confirmation test was conducted.

As shown in Table 1 for Examples 1 to 10, mosquito control aerosols were prepared with compositions and conditions according to each Example, and the following tests were carried out. For Comparative Examples 1 and 2, mosquito control aerosols were also prepared with compositions and conditions shown in Table 1, and tests similar to those for the Examples were carried out. The test results are shown in Table 2.
(1) Control effect against adult mosquitoes in a 25 ^m3 room In the center of a closed 25 ^m3 room, a mosquito control aerosol was sprayed once diagonally upward, and immediately after this, 50 adult female Culex pipiens mosquitoes were released and exposed for 2 hours, after which all the test mosquitoes were collected. During this time, the number of adult female Culex pipiens mosquitoes that fell and rolled over over time was counted to calculate the _KT50 value. The same procedure was then repeated in the same room 10 hours, 14 hours, and 20 hours after the first spray of the mosquito control aerosol.
(2) Airborne Particle Residual Rate The mosquito control aerosol was sprayed once diagonally upward toward the center of a closed 25 ^m3 room. An air collection tube (a glass tube filled with silica gel and both ends packed with absorbent cotton) was installed 50 cm behind the center of the room (130 cm from the wall) and 120 cm above the floor, and connected to a vacuum pump to aspirate a predetermined amount of air 2 hours after the spraying treatment. The air collection tube was washed with acetone, and the amount of the collected pest control component was analyzed by gas chromatography (Shimadzu Corporation, model GC1700). Based on the obtained analytical value, the air concentration of the pest control component was calculated, and the ratio to the theoretical air concentration was calculated as the air residual rate.

From the results of Tables 1 and 2, when metofluthrin and/or transfluthrin were used as the pest control ingredient (Examples 1 to 7, 9, and 10), the KT ₅₀ value was maintained at a significant value even 20 hours after one spray of the mosquito control aerosol, and it was found to have an excellent control effect. The control effect was also excellent when a small amount of profluthrin was added to transfluthrin (Example 8). In addition, it was found that, as the organic solvent to be combined with the pest control ingredient, a higher fatty acid ester having a total number of carbon atoms of 16 to 20, such as isopropyl myristate, and a lower alcohol having a carbon number of about 2 to 3, such as ethanol, are effective. On the other hand, in Comparative Examples 1 and 2, the KT ₅₀ value was inferior to that of the Examples 10 hours after one spray of the mosquito control aerosol, and after 14 hours, the results were even worse. And, after 20 hours, it was shown that the control effect against female adult Culex pipiens mosquitoes was almost extinguished in all Comparative Examples.

Next, a test was conducted to confirm the mosquito control effect of the mosquito control aerosol of the present invention on mosquitoes different from those in Examples 1 to 10. This test is designated as Example 11.
In Example 11, the pest control component metofluthrin was dissolved in isopropyl palmitate, an organic solvent, to prepare an aerosol concentrate containing 36.0% by weight of metofluthrin. 4.0 mL of this aerosol concentrate and 16.0 mL of liquefied petroleum gas as a propellant were pressurized and filled into an aerosol container with a metered injection valve to obtain the mosquito control aerosol of the present invention. The volume ratio (a/b) of this aerosol concentrate (a) to the propellant (b) was adjusted to 20/80. Then, 0.1 mL of the aerosol concentrate was sprayed slightly diagonally upward in a 6-tatami room (about 25 m ³ ) with a ceiling height of 2.5 m, which was almost sealed. The spray force (25°C) of the mosquito control aerosol at this time was 1.4 g·f at a spray distance of 20 cm. The 90% particle size of the volume-integrated distribution of the adhesive particles formed from the aerosol concentrate at 25° C. and a spray distance of 15 cm was 42 μm.

Immediately after spraying the mosquito control aerosol of Example 11, chironomids were released into the room, and the chironomids were immediately knocked down or killed. In addition, the residual rate of the pest control ingredient (metofluthrin) in the air was determined using the same method as in Examples 1 to 10, and was found to be 0.93%.

From the test results of Examples 1 to 11, it was revealed that the mosquito control aerosol of the present invention and the mosquito control method using the same have an excellent control effect against mosquitoes for a long period of time of more than 20 hours in a space of at least 25 m ³ (equivalent to about 6 tatami mats). It was confirmed that the mosquito control aerosol of the present invention has a mosquito control effect of more than 20 hours even when the volume of the space to be treated is expanded to 33 m ³ (equivalent to about 8 tatami mats). In addition, when a similar control effect confirmation test was conducted on flying pests other than mosquitoes, it showed a control effect against flies for more than 4 hours in a space of 33 m ³ or less, and it was found to be very practical. Furthermore, a secondary effect of repelling crawling pests such as cockroaches, ants, and beetles was also confirmed.

The present invention provides an aerosol for mosquito control that has a high control effect against mosquitoes, and a method for controlling mosquitoes using the same.

X: Adherent particles Y: Floating particles

Claims (7)

a pressure-resistant container provided with a metered-dose injection valve that contains an aerosol concentrate containing a pest control component and an organic solvent and a propellant;
an injection button provided with an injection port connected to the metered injection valve;
A mosquito control aerosol comprising:
The pest control component includes transfluthrin and/or metofluthrin,
The injection volume when the injection button is pressed once is 0.1 to 0.4 mL.
The injection force at a injection distance of 20 cm is adjusted to be 0.3 to 10.0 g·f (2.94×10 ⁻³ to 9.81×10 ⁻² N) at 25°C.
The aerosol concentrate is sprayed from the spray nozzle as adhesive particles, at least a part of which adheres to exposed areas in the treatment space where mosquitoes land,
The adhesive particles have a 90% particle size of 20 to 80 μm in a volume cumulative distribution at 25° C. and a spray distance of 15 cm;
The mosquito control aerosol has a _KT50 value of 7.7 minutes or less when the mosquito control aerosol is sprayed once, and 10 hours later, mosquitoes are released and exposed for 2 hours . The aerosol for controlling mosquitoes according to claim 1, wherein the aerosol concentrate contains 14.3% by weight or more of the pest control ingredient. The mosquito control aerosol according to claim 1 or 2, wherein the amount of the pest control component sprayed is adjusted to 5.0 to 30 mg per 4.5 to 8 tatami mats (18.5 to 33.0 ^{m 3} ) when the aerosol concentrate is sprayed once into the treatment space. The aerosol for mosquito control according to any one of claims 1 to 3, wherein the mosquito is Culex pipiens mosquito. The mosquito control aerosol according to any one of claims 1 to 4, wherein when the aerosol concentrate is sprayed once into a treatment space, the residual rate of the pest control ingredient in the air after 2 hours is 0.05 to 5%. A mosquito control method using the mosquito control aerosol according to any one of claims 1 to 5, injecting the aerosol concentrate into a treatment space to knock down or kill mosquitoes. The mosquito control method according to claim 6, wherein the aerosol concentrate is sprayed into the treatment space once every 24 hours.

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