Sustained mosquito incense

Abstract

The present application provides a persistence mosquito coil which can sustain the insecticidal effect for a long time even for a short time of combustion while reducing the irritation at the time of combustion. The persistence mosquito coil which can sustain the insecticidal effect even after combustion, comprising: an insecticidal ingredient of at least one selected from the group consisting of methofluthrin, profluthrin and transfluthrin; and a carbide base material having an iodine adsorption capacity of 200 mg / g or less, wherein the emission amount of the insecticidal ingredient per unit time at the time of combustion is set to 0.05-15 mg / min, and the combustion time is set to 30 min or less.

Description

[0001] This application is a divisional application. The parent application was filed on June 22, 2020, with international application number PCT / JP2020 / 024309 and Chinese national phase application number 202080043712.5. The invention is entitled "Continuous Mosquito Repellent". Technical Field

[0002] This invention relates to a continuous mosquito coil whose insecticidal effect persists even after burning. Background Technology

[0003] As a product used to repel flying pests such as mosquitoes, mosquito coils are widely used. They work by fumigating the air to disperse insecticidal components into the space being treated. The burning time of a single mosquito coil is set to about 7 to 8 hours to match people's bedtime. When it burns out completely, it knocks down or kills the pests in the space being treated, thereby eliminating or repelling the pests from the space.

[0004] However, in recent years, due to improvements in sanitation and changes in housing conditions, especially in urban apartments where living spaces have become increasingly enclosed, the chances of mosquitoes and other pests entering buildings from the outside have decreased. Therefore, if existing mosquitoes are eliminated before bedtime, it is no longer necessary to continuously release insecticidal components during sleep, as with traditional mosquito coils. Given this situation, attempts have been made to shorten the burning time of mosquito coils, which are currently considered essential for long-term continuous use.

[0005] For example, there are mosquito coils that use volatile pyrethroids such as methoxyfenozide, propofol, and tetrafluorobenzyl pyrethrin as insecticidal ingredients (see, for example, Patent Document 1). Because the insecticidal ingredients in the mosquito coil of Patent Document 1 remain in the air for a long time even after burning, the insecticidal effect lasts for a long time even with a shortened burning time.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-12056 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, in the online mosquito coil industry, there is a search for products that reduce the odor or irritation caused by insecticidal ingredients, fragrance ingredients, and smoke. However, Patent Document 1 focuses on shortening the burning time while allowing the necessary amount of insecticidal ingredients to volatilize, leaving room for further research on reducing irritation during combustion.

[0011] The present invention was made in view of the above-mentioned problems, and its object is to provide a continuous mosquito coil that reduces irritation during combustion and provides a long-lasting insecticidal effect even with short-term burning.

[0012] Methods for solving problems

[0013] The persistent mosquito coil of the present invention, which addresses the above-mentioned problems, is characterized in that it is a persistent mosquito coil whose insecticidal effect continues even after burning, and it contains:

[0014] Insecticidal ingredient selected from at least one of the group consisting of methoxyfenozide, propofol, and tetrafluorobenzyl; and

[0015] Carbide substrates with iodine adsorption capacity below 200 mg / g.

[0016] The persistent mosquito coil according to this formulation contains, in addition to an insecticidal ingredient selected from the group consisting of methoxyfenozide, propofol, and tetrafluorobenzyl, a carbide substrate with an iodine adsorption capacity of 200 mg / g or less. Therefore, even after combustion, the insecticidal ingredient remains in the air for a long time, thus enabling a prolonged insecticidal effect. Furthermore, the carbide substrate with an iodine adsorption capacity of 200 mg / g or less can prevent excessive decomposition of the insecticidal ingredient and reduction of insecticidal effect, while also reducing odors or irritation caused by smoke during combustion.

[0017] In the persistent mosquito coil of the present invention, preferably,

[0018] The amount of the insecticidal component volatilized per unit time during combustion was set to 0.05–15 mg / min.

[0019] According to the continuous mosquito coil of this composition, by making the amount of insecticidal component volatilized per unit time within the above-mentioned range, even with short-term burning, a sufficient amount of insecticidal component can be volatilized into the air.

[0020] In the persistent mosquito coil of the present invention, preferably,

[0021] Set the burning time to within 30 minutes.

[0022] This continuous-burning mosquito coil, with its burning time set to within 30 minutes, allows for mosquito repellency by burning only before bedtime, making it an easy-to-use product.

[0023] In the persistent mosquito coil of the present invention, preferably,

[0024] Set the duration of the insecticidal effect after burning to more than 8 hours.

[0025] This continuous-burning mosquito coil, by setting the duration of its insecticidal effect after burning to 8 hours or more, ensures that humans will not be bitten by mosquitoes throughout the night and can sleep comfortably. Furthermore, if the burning time is set to within 30 minutes and the duration of the insecticidal effect is set to 8 hours, the flame of the continuous-burning mosquito coil extinguishes when people are about to fall asleep, eliminating concerns about fire hazards and allowing for safe use even at night.

[0026] In the persistent mosquito coil of the present invention, preferably,

[0027] The dosage of the insecticidal ingredient is set as C. I When the amount of the insecticidal component released after complete combustion is set as V(mg), it is set to satisfy the following formula (1):

[0028] (V / C I )×100≥40…(1).

[0029] According to the persistent mosquito coil of this configuration, by satisfying the above formula (1), a sufficient amount of insecticidal ingredient can be dispersed into the air while suppressing the amount of insecticidal ingredient.

[0030] In the persistent mosquito coil of the present invention, preferably,

[0031] The dosage of the insecticidal ingredient is set as C. I (mg), the amount of the carbide substrate is set as C B (g) When the iodine adsorption capacity of the carbide substrate is set to A (mg / g), the following equation (2) is satisfied:

[0032] C I / (C B ×A)≥3Δ10 -2 …(2).

[0033] According to the continuous mosquito coil of this configuration, by satisfying the above formula (2), it is possible to prevent the excessive decomposition of insecticidal components due to the iodine adsorption capacity of the carbide substrate, while allowing an appropriate amount of insecticidal components to volatilize after combustion so that the insecticidal effect can be sustained for a long time. Detailed Implementation

[0034] The following description permanent mosquito coil of the present invention. However, the present invention is not intended to be limited to the configuration described in the embodiments described below.

[0035] [Continuous mosquito coils]

[0036] The persistent mosquito coil of the present invention contains an insecticidal ingredient and a carbide base material. For example, it is obtained by adding an appropriate amount of water to a mixed powder containing the insecticidal ingredient and the carbide base material, kneading it, molding it through an extruder and a die-cutting machine, and then naturally drying or heating it. In the mixed powder, other base materials such as combustion improvers, extenders, and binders can be incorporated. It should be noted that the insecticidal ingredient may not be directly incorporated into the mixed powder, but rather applied after molding by spraying or coating with a liquid containing the insecticidal ingredient. The dimensions of the persistent mosquito coil are preferably set to a total length of 100 mm or less, a thickness of 7 mm or less, and a weight of 5 g or less; more preferably, a total length of 20 mm or more and 90 mm or less, a thickness of 2 mm or more and 5 mm or less, and a weight of 0.2 g or more and 3 g or less. The shape of the persistent mosquito coil can be appropriately selected according to its intended use, such as a stick shape, a spiral shape, a cone shape, or a plate shape, but a stick shape, a spiral shape, or a plate shape are preferred.

[0037] As insecticidal ingredients, methoxyfenozide, propofol, or tetrafluorobenzyl are used as pyrethroid insecticidal ingredients with room-temperature volatility. Any isomer can be used when the chemical structure of these pyrethroid insecticidal ingredients contains optical or geometric isomers based on asymmetric carbon or double bonds. These pyrethroid insecticidal ingredients can be used alone or as a mixture of two or more, but methoxyfenozide is preferred. Here, "room-temperature volatility" means a vapor pressure of 2 × 10⁻⁶ at 30°C. -4 ~1×10 -2 mmHg. Methoxyfenozide, propofol, and tetrafluorobenzyl are volatile at room temperature, so they remain in the air for a long time after the burning of persistent mosquito coils, thus providing a prolonged insecticidal effect. Furthermore, some of these substances adhere to surfaces such as walls after volatilization and come into contact with mosquitoes that tend to alight on surfaces, thereby maintaining a sustained insecticidal effect. It should be noted that in this specification, the insecticidal effect includes not only the effect of killing or knocking down pests, but also the pest-repelling effect that prevents pests from approaching.

[0038] The content of the insecticidal ingredient relative to the total weight of the continuous mosquito coil is preferably 0.1 to 5% by weight, more preferably 0.2 to 3% by weight. When the content of the insecticidal ingredient is less than 0.1% by weight, there is a possibility that the insecticidal effect may not be sufficient. When the content of the insecticidal ingredient exceeds 5% by weight, since the insecticidal ingredient is not a component that promotes direct combustion, there is a possibility that the continuous mosquito coil may self-extinguish.

[0039] As the carbide base material, a carbide base material with an iodine adsorption capacity of 200 mg / g or less is used. Specifically, as the carbide base material, examples include carbide base materials derived from plants such as charcoal, bamboo charcoal, plant-based activated carbon, coconut shell charcoal, and coffee grounds charcoal, as well as carbide base materials derived from non-plant substances such as carbon black, graphite, acetylene black, coal-based activated carbon, and petroleum-based activated carbon. Carbide base materials derived from plants are particularly preferred. Details will be described in the examples below. When a carbide base material with an iodine adsorption capacity of 200 mg / g or less is incorporated into the continuous coil mosquito-repellent incense, it is possible to prevent excessive decomposition of the insecticidal component due to the iodine adsorption capacity of the carbide base material while effectively reducing or alleviating the odor or irritation caused by the smoke during the burning of the continuous coil mosquito-repellent incense. When the iodine adsorption capacity of the carbide base material exceeds 200 mg / g, there is a risk that the insecticidal component will decompose excessively and the sufficient insecticidal effect will not be obtained. In addition, in the continuous coil mosquito-repellent incense of the present invention, it is also possible to mix and use multiple types of carbide base materials with different iodine adsorption capacities so that the iodine adsorption capacity becomes 200 mg / g or less. It should be noted that the iodine adsorption capacity is measured according to the activated carbon test method specified in JIS K 1474.

[0040] The content of the carbide base material is preferably 20 to 80% by weight based on the total weight of the continuous coil mosquito-repellent incense. When the content of the carbide base material is less than 20% by weight, there is a risk that the odor or irritation caused by the smoke during combustion cannot be sufficiently alleviated. When the content of the carbide base material exceeds 80% by weight, there is a risk that the formability or strength of the continuous coil mosquito-repellent incense cannot be ensured.

[0041] The combustion aid (Japanese: 支燃剤) is incorporated to stabilize the combustion of the continuous coil mosquito-repellent incense. The extender (Japanese: 増量剤) is incorporated to improve the formability of the continuous coil mosquito-repellent incense. The binder is incorporated as an adhesive to bind and strengthen the raw materials. The combustion aid, extender, and binder form the base material of the continuous coil mosquito-repellent incense. Examples of suitable combustion aids include wood powder, pyrethrum extraction residue powder, citrus peel powder, tea powder, coconut shell powder, etc. These combustion aids can be used alone or as a mixture of two or more. Examples of suitable extenders include diatomaceous earth, talc, clay, kaolin, etc. These extenders can be used alone or as a mixture of two or more. Examples of suitable binders include tab powder (Japanese: タブ粉), starch (α-starch, tapioca starch, etc.), methylcellulose, carboxymethylcellulose (CMC), etc. These binders can be used alone or as a mixture of two or more. The carbide base material, combustion aid, extender, and binder are the base materials of the continuous coil mosquito-repellent incense, and the content of the base materials is preferably 90% by weight or more based on the total weight of the continuous coil mosquito-repellent incense.

[0042] Mosquito coils are usually given a scent suitable for incense, but recently, various volatile fragrance ingredients are sometimes added for the purpose of achieving a fragrance or relaxation effect. The persistent mosquito coil of the present invention, regardless of the addition of fragrance ingredients, can suppress odors or irritation caused by smoke during combustion and provides a long-lasting insecticidal effect. However, in the persistent mosquito coil of the present invention, various fragrance ingredients may be added for the purpose of achieving a fragrance or relaxation effect. Examples of fragrance ingredients include: galaxolide, ketone musk, hexyl cinnamaldehyde, ambroxol, methyl dihydrojasmone, ethylene brassylate, geraniol, synthetic oakmoss, hexyl salicylate, and tricyclodecenyl acetate. Acetate), Orange Crystal (Japanese: オレンジャークリスタル), Ambroxan, Tonalide (6-acetyl-1,1,2,4,4,7-hexamethyltetrahydronaphthalene), γ-undecyl lactone, Cashmereone (Japanese: キャシュメラン), Calone, Heliotropin, Dihydroindenyl-2,4-dioxane, Ionone (α-isomethyl ionone), Indole, Methyl cedarwood ketone (Japanese: メチルセドリルケトン), Methyl β-naphthyl ketone, Rosephenone, Coumarin, Vanillin, Styrax The fragrance components include resinoid, benzyl benzoate, undecylaldehyde, benzyl salicylate, ionone, α-ionone, β-ionone, lily aldehyde, 3,5-dinitro-2,6-dimethyl-4-t-butylacetophenone, acetylacetone, 2-cyclohexyl-2-phenylacetaldehyde, isolongifolanone, and cis-3-hexenol. These fragrance components can be used alone or as a mixture of two or more. The content of the fragrance component relative to the total weight of the persistent mosquito coil is preferably 0.001 to 5% by weight, more preferably 0.01 to 1% by weight. When the content of the fragrance component is less than 0.001% by weight, there is a possibility that sufficient fragrance cannot be produced. When the content of the fragrance component exceeds 5% by weight, there is a risk of excessive enhancement of odor or irritation.

[0043] In the persistent mosquito coil of the present invention, other components may include antifungal agents, preservatives, stabilizers, efficacy enhancers, deodorizers, etc. Examples of antifungal agents or preservatives include: dehydroacetates, sorbates, p-hydroxybenzoates, etc. Examples of stabilizers include: 2,6-di-tert-butyl-4-methylphenol (BHT), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butylenebis(3-methyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, etc. By adding such a stabilizer, not only is the long-term stability of the insecticidal component enhanced during storage, but its stability during fumigation is also improved. Furthermore, it helps to increase the persistence of the active ingredient's efficacy after volatilization. The amount of stabilizer added is preferably 0.01 to 0.5 times that of the insecticidal component. Examples of efficacy enhancers include piperonyl butoxide and N-(2-ethylhexyl)-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid imide. Additionally, persistent mosquito coils may also contain colorants such as malachite green and food additives (e.g., food blue 1, food yellow 4, food red 106).

[0044] [Burning Time]

[0045] Traditional mosquito coils repel mosquitoes by releasing insecticidal components through fumigation during combustion. However, smoke production can be a concern when using them, especially during bedtime. The continuous-burning mosquito coil of this invention retains its insecticidal components in the air even after prolonged burning, thus maintaining its effectiveness. By setting the burning time within an appropriate range, user-friendliness is improved. The burning time of this continuous-burning mosquito coil, from ignition to burnout, is preferably within 30 minutes. By setting the burning time to within 30 minutes, mosquito repellency can be maintained for an extended period during sleep, and the continuous-burning mosquito coil can be completed shortly before or immediately after bedtime, allowing for peaceful sleep without worrying about smoke. It should be noted that the duration of the insecticidal effect (the time during which mosquitoes are repelled) after burning is preferably 8 hours or more, more preferably 10 hours or more, and most preferably 12 hours or more. By setting the duration of the insecticidal effect after burning to 8 hours or more, for example, when used at night, a person can sleep comfortably without being bitten by mosquitoes throughout the night. Furthermore, if the burning time is set to within 30 minutes and the duration of the insecticidal effect after burning is set to 8 hours, the flame of the continuous-burning mosquito coil will extinguish when people go to sleep, thus eliminating concerns about fire hazards and allowing for safe use even at night. Therefore, although the continuous-burning mosquito coil of the present invention has a short burning time, its long-lasting insecticidal effect makes it suitable for indoor use, especially in well-sealed spaces. However, the continuous-burning mosquito coil of the present invention can also be used outdoors.

[0046] [Amount of insecticidal ingredient volatilized per unit time]

[0047] The continuous-burning mosquito coil of the present invention sets the amount of insecticidal component volatilized per unit time during combustion within an appropriate range, so that even with short-duration combustion, a sufficient amount of insecticidal component can be volatilized into the air. Here, the amount of insecticidal component volatilized during complete combustion of the continuous-burning mosquito coil is calculated as follows: The continuous-burning mosquito coil is completely burned in an exhaust bellows connected to a glass tube containing silica gel. Air is drawn from the exhaust bellows using a pump, thereby capturing the insecticidal component volatilized during combustion. The captured insecticidal component is then analyzed by gas chromatography. The volatilization amount per unit time, obtained by dividing the calculated volatilization amount by the combustion time, is preferably 0.05 to 15 mg / min, more preferably 0.1 to 10 mg / min. If the volatilization amount per unit time is within the above range, even with short-duration combustion of 30 minutes or less, an appropriate amount of insecticidal component can be volatilized into the air. Furthermore, if the volatilization rate of the insecticidal ingredient per unit time is within the aforementioned range, even if the iodine adsorption capacity of the carbide substrate is less than 200 mg / g, the odor or irritation caused by smoke during combustion can be reduced. If the volatilization rate of the insecticidal ingredient per unit time is less than 0.05 mg / min, in short-duration combustion of less than 30 minutes, there is a risk that a sufficient amount of the insecticidal ingredient may not be volatilized into the air, resulting in a lack of sustained insecticidal effect. If the volatilization rate of the insecticidal ingredient per unit time exceeds 15 mg / min, there is a risk that the odor or irritation caused by smoke during combustion may not be sufficiently mitigated. In addition, since the insecticidal ingredient is not a component that promotes direct combustion, there is a possibility that the mosquito coil may continue to extinguish.

[0048] [Insecticidal ingredient retention rate]

[0049] In the persistent mosquito coil of the present invention, the amount of insecticidal ingredient is set as C. I When the amount of insecticidal component volatilized after complete combustion is set as V (mg), the amount of insecticidal component volatilized V and the amount of insecticidal component combined C are... I The ratio, i.e. the maintenance rate of the insecticidal component, preferably satisfies the following formula (1).

[0050] Insecticidal ingredient retention rate = (V / C) I )×100≥40…(1)

[0051] By satisfying the conditions of equation (1), since the insecticidal components are not excessively decomposed during the storage and combustion of the continuous mosquito coil, a sufficient amount of insecticidal components can be released into the air during combustion while suppressing the amount of insecticidal components added during manufacturing. When the insecticidal component retention rate is less than 40%, there is a risk that the amount of insecticidal components required during the manufacturing of the continuous mosquito coil will increase, which may become economically disadvantageous. In addition, since the insecticidal components are not components that contribute to direct combustion, increasing the amount of insecticidal components may lead to the continuous mosquito coil extinguishing.

[0052] [Insecticidal ingredient / adsorption capacity ratio]

[0053] In online mosquito coils, the amount of insecticidal ingredient is set as C. I (mg), the amount of carbide substrate is set as C B (g), when the iodine adsorption capacity of the carbide substrate is set as A (mg / g), the amount of carbide substrate C is... B The product of the iodine adsorption capacity A of the carbide substrate and the total iodine adsorption capacity of the continuous mosquito coil is represented. Here, the total iodine adsorption capacity is expressed relative to the amount C of the carbide substrate. B The amount of insecticidal ingredient C is the product of the iodine adsorption capacity A of the carbide substrate. I The ratio, i.e., the ratio of insecticidal ingredient to adsorption capacity, affects the amount of insecticidal ingredient volatilized. In the persistent mosquito coil of the present invention, the ratio of insecticidal ingredient to adsorption capacity preferably satisfies the following formula (2).

[0054] Insecticidal ingredient / adsorption capacity ratio = C I / (C B ×A)≥3×10 -2 …(2)

[0055] By satisfying equation (2), the proportion of insecticidal components decomposed due to the iodine adsorption capacity of the carbide substrate becomes sufficiently small relative to the amount of insecticidal components incorporated during manufacturing, both during the storage and combustion of the continuous-acting mosquito coil. Therefore, even if some insecticidal components decompose during the storage and combustion of the continuous-acting mosquito coil, an appropriate amount of insecticidal components capable of providing a long-lasting insecticidal effect can be released after combustion. The ratio of insecticidal component to adsorption capacity is less than 3 × 10⁻⁶. -2 At that time, relative to the amount of insecticidal ingredients used in manufacturing, the proportion of insecticidal ingredients decomposed due to the iodine adsorption capacity of the carbide substrate increases during the storage and burning of continuous mosquito coils, which may result in insufficient insecticidal ingredients volatilized during combustion.

[0056] [Target pests]

[0057] The continuous mosquito coil of this invention does not have any particular limitation on the pests targeted for control. For example, it can be listed as: Culex pipiens pallens, Culex tritaeniorhynchus, Culex quinquefasciatus, and other Culex species; Aedes aegypti and Aedes albopictus species; midges; houseflies; caterpillar flies; flea flies; hymenopterans; horseflies; midges; clothes moths and other flying pests; as well as cockroaches such as German cockroaches, American cockroaches, and black-breasted cockroaches; mites; ants; bedbugs; rodents; leeches; weevils and other crawling pests. Among these pests, it is particularly effective against Culex pipiens and Aedes mosquitoes.

[0058] Example

[0059] [Example 1]

[0060] A mixture of charcoal powder A (50 parts by weight) with an iodine adsorption capacity of 25 mg / g as a carbide base, methoxybenzyl fluoroacetate (1.5 parts by weight) as an insecticide, a mixed fragrance including galacin and ketone musk (0.8 parts by weight) as a fragrance component, pyrethrum extract residue powder (17 parts by weight) as a combustion aid and extender, wood flour (10.7 parts by weight) and diatomaceous earth (3 parts by weight), α-starch (14 parts by weight) and carboxymethyl cellulose (CMC) (3 parts by weight) as a binder, and water (90 parts by weight) was added and thoroughly mixed. The mixture was extruded into rods and then dried until the moisture content was about 7-10% by weight to produce the persistent mosquito coil of Example 1. The persistent mosquito coil of Example 1 has an insecticide / adsorption capacity ratio of 1.2 and satisfies the conditions of the aforementioned formula (2).

[0061] The continuous mosquito coil from Example 1 was used in a 10-tatami room (16.7m²). 2 Height 2.5m, Volume 41.7m³ 3 When used, it burned out in approximately 23 minutes, but no mosquitoes or other pests approached it for 12 hours after burning. Therefore, it is concluded that the continuous-burning mosquito coil of Example 1 retains sufficient insecticidal components indoors for 12 hours after burning. Furthermore, the continuous-burning mosquito coil of Example 1 produces little smoke during combustion, has no pungent odor, and emits a faint floral scent. This fragrance is relaxing and suitable for use in bedrooms.

[0062] [Examples 2-12]

[0063] Using charcoal powder A (with an iodine adsorption capacity of 25 mg / g) and charcoal powder B (with an iodine adsorption capacity of 838 mg / g) as the carbide substrate, persistent mosquito coils having the characteristic structure of the present invention were prepared according to Example 1, as shown in Table 1. The insecticidal component / adsorption capacity ratio of the persistent mosquito coils in Examples 2-12 was 3.1 × 10⁻⁶. -2~2.2, all of which satisfy the conditions of the aforementioned equation (2).

[0064] [Comparative Examples 1-3]

[0065] Using charcoal powder A (with an iodine adsorption capacity of 25 mg / g) and / or charcoal powder B (with an iodine adsorption capacity of 838 mg / g) as the carbide substrate, in the combination shown in Table 2, according to Example 1, persistent mosquito coils (Comparative Examples 1-3) without the characteristic structure of the present invention were prepared. The persistent mosquito coils of Comparative Examples 1-3, compared to the specifications of the present invention, are examples of those with a greater iodine adsorption capacity of the carbide substrate, with an insecticidal component / adsorption capacity ratio of 7.2 × 10⁻⁶. -3 ~2.2×10 -2 All of them are less than the conditions of the aforementioned equation (2).

[0066] [Reference Example]

[0067] Without using a carbide substrate with iodine adsorption capacity, a continuous mosquito coil was prepared according to Example 1 using the formulations shown in Table 2 (reference example).

[0068]

[0069]

[0070] The following tests (1) to (4) were conducted using the persistent mosquito coils of Examples 1 to 12, Comparative Examples 1 to 3 and Reference Examples.

[0071] (1) Stability over time

[0072] The insecticidal components in persistent mosquito coils stored at 50°C for one month were analyzed by gas chromatography. The recovery rate of the insecticidal components was calculated from the content of the insecticidal components after one month of storage and the amount of insecticidal components mixed with those used in manufacturing. The stability over time was determined according to the following criteria.

[0073] A: The insecticidal ingredient recovery rate is over 95%.

[0074] B: The recovery rate of the insecticidal ingredient is over 90% and less than 95%.

[0075] C: The recovery rate of the insecticidal ingredient is less than 90%.

[0076] (2) Insecticidal component retention rate

[0077] In an exhaust bell connected to a glass tube containing silica gel, a continuous mosquito coil is completely burned. Air is drawn from the exhaust bell by a pump to capture the insecticidal components that volatilize during combustion. The captured insecticidal components are analyzed by gas chromatography to calculate the amount of insecticidal components volatilized during the complete combustion of the continuous mosquito coil. Then, the insecticidal component retention rate is calculated according to the above formula (1) by combining the calculated amount of volatilization with the amount of insecticidal components used in manufacturing.

[0078] (3) Preference

[0079] A continuous mosquito coil was burned inside a glass cylinder with a diameter of 20 cm and a height of 40 cm. Ten testers rated the mosquito coil based on their preference for mildness of irritation and fragrance, with the highest score as 10 and the lowest score as 1. The average score from the ten testers was calculated as the result of the sensory evaluation of preference.

[0080] (4) Field insecticidal efficacy test

[0081] In the 25m of closure 3 In the center of the room, a continuous mosquito coil was burned. After burning for 8 hours, 50 adult female Culex pipiens pallens were placed in the room and exposed for 2 hours, after which all the test mosquitoes were retrieved. During this period, the number of adult female Culex pipiens pallens that fell and turned upwards was counted as time passed, and the time point when 25 adult female Culex pipiens pallens fell and turned upwards was set as KT. 50 Value (rounded to the nearest decimal).

[0082] [Table 3]

[0083]

[0084] For the persistent mosquito coils of Examples 1-12, which contain methoxyfenozide, propofol, or tetrafluorobenzyl as insecticidal ingredients and have a carbide substrate with an iodine adsorption capacity of less than 200 mg / g, it was confirmed that they exhibit excellent long-term stability, with the insecticidal ingredient retention rate of any one of them exceeding 40%. Although the burning time is short, less than 30 minutes, the KT value remains high even after 12 hours from the start of combustion. 50 The value is set to less than 30 minutes, resulting in excellent insecticidal effect. It is believed that the continuous mosquito coils of Examples 1 to 12 have the same or better stability over time and insecticidal effect 12 hours after combustion as the reference example without a carbide substrate with iodine adsorption capacity. Therefore, by suppressing the iodine adsorption capacity of the carbide substrate to less than 200 mg / g, excessive decomposition of insecticidal components caused by the carbide substrate will not occur.

[0085] In addition, for the continuous coil incense of the reference examples, the smoky odor and large amount of smoke are bothersome. In contrast, the continuous coil incenses of Examples 1 to 12 all emit a highly preferred fragrance after burning and do not overly fill with smoke, and are relatively easy to use in actual use with excellent irritation mitigation and odor preference. Therefore, it is considered that for the continuous coil incenses of Examples 1 to 12, although the iodine adsorption capacity of the carbide substrate is 200 mg / g or less, the effects of reducing odors and irritation caused by smoke during combustion are still sufficiently obtained.

[0086] It should be noted that among the continuous coil incenses of Examples 1 to 12, those with a relatively low volatilization rate of the insecticidal component per unit time (Examples 4 to 6, 8) tend to have a slightly reduced efficacy. In addition, for Example 3 with an extremely large volatilization rate of 10.2 mg / minute per unit time, there is a case where the combustion of the continuous coil incense cannot continue until the end. Therefore, the volatilization rate of the insecticidal component per unit time is preferably 0.05 to 15 mg / minute, more preferably 0.1 to 10 mg / minute.

[0087] Comparing Example 9 with Example 1, the compounding amounts of the insecticidal component and the carbide substrate are the same, and only the types of the fragrance components are different, but there is not much difference in the insecticidal component retention rate and the KT 50 value 12 hours after ignition. Comparing Example 10 with Example 1, the compounding amounts of the insecticidal component and the carbide substrate are the same, and the difference lies in that the fragrance component is not compounded, but there is not much difference in the insecticidal component retention rate and the KT 50 value 12 hours after ignition. Therefore, it is considered that the types and compounding amounts of the fragrance components do not have a significant impact on the decomposition of the insecticidal component caused by the iodine adsorption capacity of the carbide substrate.

[0088] In contrast, as in Comparative Examples 1 to 3, when methoxybenzyl flucythrinate is contained as the insecticidal component and the carbide substrate has an iodine adsorption capacity exceeding 200 mg / g, the stability of the insecticidal component over time is insufficient, the insecticidal component retention rate is less than 40%, and the KT 50 value also reaches 120 minutes or more, and a sufficient insecticidal effect cannot be obtained. The reason is considered to be that due to the iodine adsorption capacity of the carbide substrate exceeding 200 mg / g, excessive decomposition of the insecticidal component caused by the carbide substrate occurs. In addition, for the continuous coil incenses of Comparative Examples 1 to 3, it is also difficult to feel the aromaticity brought by the fragrance component, resulting in a feeling of deterioration of the fragrance (Japanese: 香調).

[0089] Industrial Applicability

[0090] The persistent mosquito coil of the present invention can be used for household or commercial purposes, and is particularly suitable for mosquito control, such as Culex pipiens pallens, Culex tauren, and Aedes albopictus.

Claims

1. A continuous-acting mosquito coil, wherein the insecticidal effect continues even after burning, comprising: Insecticidal ingredient selected from at least one of the group consisting of methoxyfenozide, propofol, and tetrafluorobenzyl; and Plant-derived carbide substrates with iodine adsorption capacity of 25 mg / g to 200 mg / g. The content of the insecticidal ingredient is 0.1% to 5% by weight relative to the total weight of the persistent mosquito coil. The content of the carbide substrate relative to the total weight of the persistent mosquito coil is 20% to 80% by weight. The weight of the continuous mosquito coil is 0.2g to 5g. The amount of the insecticidal component volatilized per unit time during combustion was set to be 0.1 mg / min to 15 mg / min.

2. The continuous mosquito coil according to claim 1, wherein the burning time is set to within 30 minutes.

3. The continuous mosquito coil according to claim 1 or 2, wherein the duration of the insecticidal effect after burning is set to more than 8 hours.

4. The persistent mosquito coil according to claim 1 or 2, wherein, The dosage of the insecticidal ingredient is set as C. I When the amount of volatile insecticidal component released after complete combustion is set as V, it is set to satisfy the following formula (1), wherein C I Both V and mg are in units of mg. 。