JP7593770B2 - Water-based agent for thermal evaporation - Google Patents

Description

The present invention relates to an aqueous medicine for thermal evaporation, and more specifically, to an aqueous medicine for thermal evaporation used in a thermal evaporation method in which an active ingredient absorbed in a thermal evaporation wick is evaporated by heating.

Conventionally, a liquid heat-transfer agent is absorbed into a heat-transfer wick, which is then heated to transpire the active ingredient contained in the heat-transfer agent, thereby obtaining the medicinal effects of the active ingredient.

As a heat-transfer agent, a heat-transfer insecticide composition containing a pyrethroid compound or the like as an active ingredient is widely used, and various types are being investigated. Since the active ingredients of pyrethroid compounds and the like are oil-based, most of them are formulated by dissolving them in an oil-based solvent such as kerosene.

On the other hand, for the purpose of achieving greater safety, aqueous insecticide compositions for thermal evaporation containing aqueous solvents such as water or glycol ether have been investigated.
For example, Patent Document 1 proposes an aqueous insecticide composition for heat evaporation for controlling mosquitoes with reduced sensitivity to pyrethroid insecticidal components, the aqueous insecticide composition for heat evaporation containing 0.1 to 3.0 mass % of a pyrethroid insecticidal component, 10 to 70 mass % of at least one glycol ether compound having a boiling point of 150 to 300° C. as an auxiliary agent for dealing with the reduced sensitivity, and water.

International Publication No. 2016/140172

However, the incorporation of an aqueous solvent into an insecticide composition for thermal evaporation can cause clogging of the thermal evaporation core and reduce the pest control effect. In addition, glycol ethers and the like have a strong and irritating solvent odor when thermally evaporated, which can cause discomfort to users.

The present invention aims to provide a new aqueous chemical for thermal evaporation that contains water and has a higher effect than conventional aqueous chemicals for thermal evaporation, while reducing the solvent odor and irritation during use.

The inventors conducted research in light of the above problems and found that the above problems can be solved by incorporating a glycol solvent having 4 to 6 carbon atoms in the aqueous agent for thermal evaporation at 70 v/v % or more.

That is, the present invention is characterized by the following (1) and (2).
(1) An aqueous preparation for thermal evaporation, comprising a thermally evaporable active ingredient, a glycol-based solvent having 4 to 6 carbon atoms, and water, the content of the glycol-based solvent being 70 to 95 v/v %.
(2) The aqueous medicine for thermal evaporation according to (1) above, characterized in that the glycol-based solvent is a solvent having a 1,3-butylene glycol skeleton.

The aqueous formulation for thermal evaporation of the present invention can increase the efficacy of the active ingredient by thermal evaporation. It can also reduce the solvent odor and irritation during use, improving the feeling of use.

FIG. 1 is a schematic diagram illustrating a test room used in an insecticidal efficacy test. FIG. 2 is a schematic diagram for explaining a test method for a sensory evaluation test.

Hereinafter, the embodiments of the present invention will be described in more detail.
The aqueous medicine for thermal evaporation of the present invention contains a thermally evaporable active ingredient, a glycol-based solvent having 4 to 6 carbon atoms, and water.

The active ingredient is one that evaporates when heated, and can be appropriately selected depending on the application of the aqueous agent for thermal evaporation. Examples of active ingredients include insecticides, repellents, bactericides/fungicides, deodorants/odor removers, and fragrances.

Examples of insecticides include pyrethroid compounds such as allethrin, phthalthrin, resmethrin, furamethrin, fenothrin, permethrin, empentrin, 1-ethynyl-2-ethyl-2-pentenyl-2,2,3,3-tetramethyl-cyclopropanecarboxylate, 1-ethynyl-2-methyl-2-pentenyl-2,2-dimethyl-3-(2',2'-dichlorovinyl)-cyclopropanecarboxylate, prallethrin, tefluthrin, transfluthrin, metofluthrin, and profluthrin; carbamey compounds such as propoxur and carbaryl; These include phosphatidylcholine compounds; organophosphorus compounds such as fenitrothion and diclofenac (DDVP); oxadiazole compounds such as methoxadiazone; phenylpyrazole compounds such as fipronil; sulfonamide compounds such as amidoflumet; neonicotinoid compounds such as dinotefuran and imidacloprid; insect juvenile hormone agents such as methoprene and hydroprene; anti-juvenile hormone agents such as precocene; and molting hormone agents such as ecdysone; and essential oils such as phytoncides, peppermint oil, orange oil, cinnamon oil, benzyl alcohol, and clove oil.

Examples of repellents include DEET, paramenthan-3,8-diol, rotenone, di-n-butyl succinate, hydroxyanisole, ethyl 3-(N-n-butyl-N-acetylamino)propionate, and 1-piperidine carboxylate 2-(2-hydroxyethyl)-1-methylpropyl ester.

Examples of antibacterial and antifungal agents include isopropylmethylphenol, parachlorometaxylenol, triclosan, 3-iodomethyl-2-propenyl butylcarbamate, 2-(4-thiazolyl)benzimidazole, cetylpyridinium chloride, 4-4-dimethyl-1,3-oxazolidine, poly(hexamethyl)biguanide hydrochloride, hinokitiol, and essential oils such as origanum oil, cinnamon oil, lemongrass oil, peppermint oil, and eucalyptus oil.

Examples of deodorants include lauryl methacrylate, geranyl crotonate, catechin, polyphenols, etc.

The fragrance may be either natural or synthetic, or may be a blended fragrance. The type of fragrance may be either animal-derived or vegetable-derived.

Natural fragrances include, for example, animal fragrances such as musk, spirit cat fragrance, and dragon's-eye fragrance; rose oil, lavender oil, peppermint oil, lemon oil, abies oil, ajokun oil, almond oil, angelica root oil, peper oil, bergamot oil, perch oil, boa burdock oil, kayabuchi oil, gananga oil, capsicum oil, caraway oil, cardamom oil, cassia oil, celery oil, cinnamon oil, citronella oil, cognac oil, and coriander. These include botanical flavors such as spice oil, cupule oil, garlic oil, ginger oil, grapefruit oil, hops oil, juniper berry oil, laurel leaf oil, lemon oil, lemongrass oil, rose oil, mace oil, nutmeg oil, mandarin oil, tangerine oil, mustard oil, lantern flower oil, onion oil, pepper oil, orange oil, sage oil, star anise oil, turpentine oil, wormwood oil, and wanilla bean extract.

Examples of synthetic or blended fragrances include hydrocarbons such as pinene and limonene; alcohols such as linalool, geraniol, citronellol, menthol, borneol, benzyl alcohol, and anise alcohol; phenols such as anethole and eugenol; aldehydes such as n-butyraldehyde, isobutyraldehyde, citral, citronellal, benzaldehyde, cinnamic aldehyde, and vanillin; ketones such as carvone, menthone, and camphor; lactones or oxides such as amylbutyrolactone, ethyl methylphenylglycidate, γ-nonyl lactone, coumarin, and cineol; and esters such as isopropyl isobutyrate, guanyl isovalerate, ethyl myristate, ethyl benzoate, benzyl benzoate, cinnamyl cinnamate, and methyl salicylate.

The active ingredient may be used alone or in combination of two or more.

It is preferable to mix 0.005 to 4.5 mL (v/v%) of the active ingredient in 100 mL of the aqueous drug for thermal evaporation. If the content of the active ingredient is 0.005 v/v% or more, the effect of the active ingredient can be obtained, and if it is 4.5 v/v% or less, the system of the aqueous drug for thermal evaporation will be stable. The content of the active ingredient is more preferably 0.01 to 3.0 v/v%, and even more preferably 0.05 to 1.5 v/v%.

In the present invention, the solvent contains at least water and a glycol-based solvent having 4 to 6 carbon atoms. Since the glycol-based solvent is amphipathic, it is possible to dissolve the active ingredient, which is an oily component, in the aqueous medicine for thermal evaporation, and also ensure safety during use. Furthermore, by using a glycol-based solvent having 4 to 6 carbon atoms, it is possible to reduce the solvent odor and irritation.

Examples of glycol-based solvents having 4 to 6 carbon atoms include 1,3-butylene glycol (4 carbon atoms), 2,3-butylene glycol (4 carbon atoms), diethylene glycol (4 carbon atoms), isoprene glycol (5 carbon atoms), 1,2-pentanediol (5 carbon atoms), 1,3-pentanediol (5 carbon atoms), 1,5-pentanediol (5 carbon atoms), hexylene glycol (6 carbon atoms), 1,6-hexanediol (6 carbon atoms), 1,3-hexanediol (6 carbon atoms), 1,2-hexanediol (6 carbon atoms), dipropylene glycol (6 carbon atoms), and triethylene glycol (6 carbon atoms). Preferably, the solvent has a boiling point in the range of 150 to 300° C.
The glycol solvent having 4 to 6 carbon atoms may be used alone or in combination of two or more. Among them, a glycol solvent having 4 to 6 carbon atoms and a 1,3-butylene glycol skeleton is preferred, and it is more preferred to use at least one selected from the group consisting of 1,3-butylene glycol, isoprene glycol, and hexylene glycol.

The glycol solvent having 4 to 6 carbon atoms is contained in the range of 70 to 95 mL (v/v%) per 100 mL of the aqueous medicine for thermal evaporation. In the present invention, by using a large amount of glycol solvent having 4 to 6 carbon atoms, the concentration of the thermally evaporable active ingredient contained in the evaporation particles becomes equal to or higher than the blending concentration in the aqueous medicine for thermal evaporation, and it is presumed that the efficacy of the active ingredient can be increased. In addition, unpleasant odors and irritation during thermal evaporation can be reduced, improving the feeling of use.

If the content of the glycol solvent having 4 to 6 carbon atoms is less than 70 v/v %, the solubility of the active ingredient decreases, the system of the aqueous chemical for thermal evaporation becomes unstable, and long-term storage may become difficult. If the content of the glycol solvent having 4 to 6 carbon atoms is 70 to 95 v/v %, an effective amount of the active ingredient can be contained whether the active ingredient is oil-based or aqueous, and the range of application of dissolving the active ingredient as a single liquid becomes wider regardless of the type of active ingredient. In addition, since the system of the aqueous chemical for thermal evaporation can be stabilized, the content of the active ingredient that can be blended can be increased, and the active ingredient can be more effective than in conventional aqueous chemicals for thermal evaporation.
The content of the glycol solvent having 4 to 6 carbon atoms is preferably 75 to 92 v/v %, more preferably 80 to 90 v/v %.

Water that can be used is that used for chemicals for thermal evaporation, such as distilled water, RO water, ion-exchanged water, tap water, etc.

The amount of water may be adjusted appropriately taking into consideration the balance between the above-mentioned active ingredient and the content of the glycol solvent having 4 to 6 carbon atoms, the stability of the aqueous drug for thermal evaporation, etc. Water is preferably blended in the range of 0.5 to 29.9 mL (v/v%) per 100 mL of the aqueous drug for thermal evaporation, more preferably 1.0 to 24.9 v/v%, and even more preferably 2.0 to 19.9 v/v%.

Other components can be blended into the aqueous drug for thermal evaporation as long as the effects of the present invention are not impaired. Examples of other components include organic solvents other than the glycol-based solvents having 4 to 6 carbon atoms described above, surfactants, stabilizers, dyes, etc.

Examples of organic solvents other than glycol-based solvents having 4 to 6 carbon atoms include aliphatic hydrocarbons (paraffinic hydrocarbons and unsaturated aliphatic hydrocarbons) with a boiling point range of 150 to 350°C, such as n-paraffin and isoparaffin, as well as alcohols such as glycerin, methanol, isopropanol, 1-octanol, and 1-dodecanol; ketones such as acetone and acetophenone; ethers such as dihexyl ether, diethylene glycol diethyl ether, and diethylene glycol monobutyl ether; esters such as dioctyl adipate, diethyl malonate, and diethyl phthalate; xylene, chlorthene, chloroform, and silicone oil. Among these, it is preferable to use organic solvents with a boiling point in the range of 150 to 300°C.

Examples of surfactants include polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan monooleate, polyoxyethylene alkyl ether, etc.

Examples of stabilizers include 3,5-di-t-butyl-4-hydroxytoluene (BHT), 3-t-butyl-4-hydroxyanisole (BHA), 3,5-di-t-butyl-4-hydroxyanisole, mercaptobenzimidazole, dilauryl-thio-di-propionate, 2,2'-methylene-bis-(6-t-butyl-4-methylphenol), 2,2'-methylene-bis-(6-t-butyl-4-ethylphenol), 4,4'-methylene-bis-(2,6-di-t-butylphenol), 4,4'-butylidene-bis-(6-t-butyl 1,1-bis-(4-hydroxyphenyl)cyclohexane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, octadecyl-3,5-di-t-butyl-4-hydroxyhydrocinnamate, etc.

Examples of pigments include Red No. 213 (Rhodamine B), Red No. 214 (Rhodamine B acetate), Red No. 215 (Rhodamine B stearate), Red No. 218 (Tetrachlorotetrabromofluorescein), Red No. 223 (Toluidine Red), Red No. 225 (Sudan III), Orange No. 201 (Dibromofluorescein), Orange No. 206 (Dioxyfluorescein), Yellow No. 204 (Quinoline Yellow SS), ), Green No. 202 (Quinizarin Green SS), Red No. 505 (Oil Red XO), Orange No. 401 (Hansa Orange), Orange No. 403 (Orange SS), Yellow No. 401 (Hansa Yellow), Yellow No. 402 (Pola Yellow 5G), Yellow No. 404 (Yellow AB), Yellow No. 405 (Yellow OB), Blue No. 403 (Sudan Blue B), Oil Blue BA, Purple No. 201 (Alizurin Purple SS), etc.

Aqueous pharmaceuticals for thermal evaporation contain an active ingredient, an aqueous organic solvent having 4 to 6 carbon atoms, water, and optionally other ingredients, and can be prepared by heating as necessary and mixing each ingredient uniformly.

The aqueous chemical for thermal evaporation is preferably a liquid, since it is absorbed into the thermal evaporation wick before use. Note that "liquid" refers to a substance that is fluid and can change shape depending on the shape of the container.

In addition, since the aqueous drug for thermal evaporation is used by evaporating it through heating, it is preferable that the boiling point is in the range of 150°C to 300°C.

The thermal evaporation core used in thermal evaporation using the aqueous agent for thermal evaporation of the present invention is not particularly limited as long as it is practicable, and various inorganic and organic materials can be used. Usable materials include, for example, inorganic materials such as clay, talc, kaolin, acid clay, diatomaceous earth, activated clay, gypsum, perlite, bentonite, alumina, silica, titanium, asbestos, and ceramics, and organic materials such as wood flour, cellulose, pulp, and polymer resins such as polyester resin and acrylic resin. Among these, a synthetic fiber core made by solidifying at least one selected from polyester resin, acrylic resin, etc. in a fibrous form is preferable, and one with a porosity of 20 to 80% is even more preferable.

The shape of the heat evaporation core is not particularly limited, but may be strip-shaped, cylindrical, rod-shaped, etc.

Heat evaporation using the aqueous drug for heat evaporation of the present invention can be carried out by a conventional method. Specifically, the heat evaporation method involves attaching a heat evaporation wick to a bottle filled with the aqueous drug for heat evaporation of the present invention, bringing the aqueous drug for heat evaporation into contact with the heat evaporation wick, setting this in a heat evaporation device, and heating, for example, by passing electricity through it. When the aqueous drug for heat evaporation that has been drawn up into the heat evaporation wick is heated, the active ingredient evaporates and is released into the air.

As for heating conditions, if the heating temperature is too high, evaporation may occur too quickly and the heat-transpirable active ingredient may be prone to thermal decomposition, while if the heating temperature is too low, evaporation may occur too slowly and the effectiveness of the heat-transpirable active ingredient may not be fully demonstrated. Therefore, it is preferable to heat at 40 to 450°C, and more preferably 70 to 150°C.

The present invention also provides a method for controlling pests using the aqueous formulation for thermal evaporation of the present invention.
The aqueous formulation for thermal evaporation of the present invention, which contains an insecticide as an active ingredient, is heated to evaporate the active ingredient, thereby making it possible to control target pests.

The pests to be controlled are not limited as long as the effects of the present invention can be obtained, but examples include flying pests such as mosquitoes, flies, moths, bees, stink bugs, weevils, beetles, wood beetles, burrs, and brown moths; crawling pests such as cockroaches such as the Smoky Brown cockroach, German cockroach, Japanese cockroach, American cockroach, and Brown cockroach, spiders, centipedes, ants, house centipedes, millipedes, pillbugs, woodlouse, termites, caterpillars, mites, lice, ticks, and bedbugs.

In the method for controlling pests using the aqueous agent for thermal evaporation of the present invention, it is preferable to use it in a closed space such as indoors or inside a room in order to ensure the effects of the present invention. Specifically, a thermal evaporation wick is attached to a bottle filled with the aqueous agent for thermal evaporation of the present invention, and the bottle is set in a thermal evaporation device, which is then placed on the floor or the like inside a room and electricity is applied to evaporate the insecticide into the indoor space, thereby controlling pests lurking inside the room.

The present invention will be further explained below using the following test examples, but the present invention is not limited to these examples.

<Test Example 1: Insecticidal Efficacy Test>
1. Preparation of test samples According to the formulations shown in Table 1, each component was mixed and stirred at room temperature to prepare drugs 1 to 7. In addition, as drug 8, "Water-based Kincho Liquid, odorless, replacement liquid" manufactured by Dainihon Jochugiku Co., Ltd. was prepared.
It should be noted that drugs 1 and 2 are comparative examples, drugs 3 to 7 are working examples, and drug 8 is a reference example.

45 mL of each of the drugs 1 to 8 was filled into a 45 mL bottle for thermal evaporation, the bottle cap was closed, and a thermal evaporation wick (a wick taken from "Water-based Kincho Liquid, odorless, replacement liquid" manufactured by Dainihon Jochugiku Co., Ltd., dried so that no drug remains; made of ceramics) was inserted into the bottle to prepare test samples 1 to 8.

2. Confirmation of insecticidal efficacy Test specimens 1 to 8 were left to stand overnight in a thermostatic chamber at 60° C. to allow the heat evaporation wick to absorb the insecticide and to make the liquid temperature of each specimen uniform, and then used for the following test.
The weight of each test sample was measured before and after the test, and the amount of evaporation of the aqueous pharmaceutical preparation for thermal evaporation was calculated by calculating the difference in weight.

(Test Method)
(1) A PET cage (a 14-mesh, 23 cm x 23 cm PET net folded in half into a bag) was prepared in which about 20 Culex pipiens mosquitoes (adult females) were placed as test insects.
(2) As shown in Figure 1, in a test room 10 measuring 6 tatami mats (3.6 m x 2.7 m x height 2.4 m ≒ 23.3 ^m3 ), four PET cages 1 containing Culex pipiens pallens were placed diagonally at heights of 0.75 m and 1.5 m from the floor of the test room 10, two on each side.
(3) The test specimen was placed in the heating evaporation device, which was then placed in the center 2 of the floor of the test room 10. With the test room 10 closed, electrical current was started.
(4) The number of Culex pipiens mosquitoes knocked down in each test specimen was observed over time every 5 minutes up to 2 hours after the start of the electric current.
(5) The test was performed twice, and the knockdown rate was calculated from the total number of results obtained. The KT ₅₀ value was calculated from the knockdown rate over time by the Probit method. In addition, the knockdown rate 30 minutes after the start of current application was calculated.
(6) The weight of the test specimen was measured, and the amount of evaporation was calculated from the weight before and after the test.

The results are shown in Table 2.

Regarding the appearance of the drugs prepared, drugs 2 to 7 were solubilized and transparent, but drug 1 was cloudy, the emulsion was unstable, and separation was observed over time.

From the results in Table 2, it was found that test samples 3 to 7, which used agents with a glycol solvent ratio of 70 v/v % or more (agents 3 to 7), had a KT ₅₀ of less than 20 minutes and were more effective than test samples 1 and 2. It was also found that the KT ₅₀ time became shorter as the content of the glycol solvent increased, despite the amount of evaporation becoming smaller, and test samples 4 to 7 had a knockdown rate of 100% after 30 minutes.

<Test Example 2: Sensory Evaluation Test>
1. Preparation of Test Samples According to the formulations shown in Table 3, each component was stirred and mixed at room temperature to prepare drugs 9 to 12. Here, drugs 9 to 11 have the same formulations as drugs 4, 6, and 7 in Test Example 1, respectively.
Drugs 9 to 11 are examples, and drug 12 is a comparative example.

45 mL of each of drugs 9 to 12 was filled into a 45 mL bottle for thermal evaporation, the bottle was sealed with an inner stopper, and a thermal evaporation core (made of polyester fiber, core length 73.5 mm, core diameter 7.2 mm, porosity 62%) was inserted to prepare test samples 9 to 12.

2. Confirmation of odor, irritation, and pleasantness/unpleasantness of the solvent Test specimens 9 to 12 were left overnight in a thermostatic chamber at 60°C to allow the drug to be absorbed into the heated evaporation wick and to make the liquid temperature of each specimen uniform, and then were subjected to the following tests.

(Test Method)
(1) As shown in FIG. 2 , the heating and transpiration device 5 with the test specimen set therein was placed in the center of the floor of a test chamber 20 measuring approximately 2.19 ^m3 (0.85 m × 1.35 m × 1.91 m high), and electricity was started with the test chamber 20 closed.
(2) After 12 hours had elapsed since the start of the application of the current, the odor in the room was confirmed through the small window 6 of the test room 20, and the odor, irritation, and pleasantness/unpleasantness of the solvent were evaluated based on the following evaluation criteria. The evaluation was performed by 10 subjects, and the average evaluation value was calculated.
[Evaluation of Solvent Odor]
1: Smell is noticeable 2: Slightly smell is noticeable 3: Neither 4: Slightly smell is noticeable 5: No smell is noticeable [Irritation evaluation]
1: I feel some stimulation 2: I feel some stimulation 3: I can't say either way 4: I don't feel much stimulation 5: I don't feel any stimulation [Pleasure and discomfort level]
1: Unpleasant 2: Slightly unpleasant 3: Neither 4: Slightly comfortable 5: Comfortable

The results are shown in Table 4.

The results in Table 4 show that test samples 9 to 11, which used a drug containing a glycol-based solvent, received higher ratings for the odor, irritation, and pleasantness of the solvent than test sample 12, which used a drug containing a glycol ether-based solvent, and were found to have a superior usability. Furthermore, if the odor evaluation, irritation evaluation, and pleasantness evaluation of the solvent are 2 or higher, it can be said that there is no problem with use.

Test Examples 1 and 2 demonstrated that the aqueous agent for thermal evaporation of the present invention not only has the inherent extermination effect, but also has an excellent feel when mixed with water. It is speculated that it is possible to produce formulations that are highly effective not only for the insecticides described above, but also for deodorants and disinfectants, and that are easy to use and do not cause irritation.

1 PET cage containing Culex pipiens 2 Center 5 Heating evaporation device with test specimen set 6 Small windows 10, 20 Test room

Claims (2)

1. An aqueous medicine for thermal evaporation, which is to be used by being absorbed into a thermal evaporation wick, comprising: a thermally evaporable active ingredient; at least one glycol-based solvent selected from the group consisting of 1,3-butylene glycol, isoprene glycol, and hexylene glycol; and water, wherein the content of the glycol-based solvent is 80 to 95 v/v %. A method for thermally evaporating an aqueous chemical for thermal evaporation, comprising: absorbing an aqueous chemical for thermal evaporation into a thermal evaporation wick, the aqueous chemical for thermal evaporation containing a thermally evaporable active ingredient, at least one glycol-based solvent selected from the group consisting of 1,3-butylene glycol, isoprene glycol, and hexylene glycol, and water, the glycol-based solvent content of which is 80 to 95 v/v %, and heating the aqueous chemical for thermal evaporation absorbed into the thermal evaporation wick, thereby evaporating the active ingredient.

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