JP7451077B2 - pest repellent - Google Patents

Description

The present invention relates to pest repellents containing hexyl 4-hydroxybenzoate.

Recently, various damages caused by pests have been reported. For example, gastropod pests such as slugs and snails feed on new shoots and flower buds of plants, vectors such as mosquitoes spread diseases such as malaria and Zika by transmitting pathogens, and pests such as ticks and cockroaches cause allergies. It can be the cause. Therefore, various methods using exterminators, repellents, etc. are being investigated as measures against these pests.

As a countermeasure against gastropod pests such as slugs, a method is known in which an attractive poison bait containing metaldehyde as an active ingredient is placed in the habitat of gastropod pests (Patent Document 1). However, it would not be effective unless the gastropod pests eat the poisonous bait, and there was also a risk of poisoning and death if the poisonous bait was accidentally licked by dogs or cats, or it could have a negative impact on nearby plants.

In addition, molded products or sheets that support or contain copper compounds that have a repellent effect on gastropod pests are installed at the bottom of flower pots, on the top of flower pot stands, at the bottom of exterior walls of houses, in kitchens, etc. to repel gastropod pests. A method is disclosed (Patent Document 2). However, repellents using copper compounds have low effectiveness, and there have been concerns that copper ions may be washed away by rain and have a negative impact on the environment.

As a measure against mosquitoes, a method of spraying a repellent such as DEET (N,N-diethyl-1,3-methylbenzamide) is known. DEET has a very high repellent effect against mosquitoes, and as of 2017, high-concentration (DEET 30%) products have been approved as insect repellents for humans in Japan. However, when DEET-containing repellents are repeatedly used on the skin at high concentrations, health hazards such as allergies and rough skin have been reported, and animal experiments have shown that continuous ingestion of large amounts can cause neurotoxicity. There are also reports.

On the other hand, parabens (4-hydroxybenzoic acid esters), which are widely used as preservatives in cosmetics and pharmaceuticals, are highly safe and have low skin irritation, and have not only antibacterial and antifungal effects, but also It is also known that it has a repellent effect on (Patent Document 3).

However, although lower alkyl group parabens having 1 to 4 carbon atoms, such as methylparaben and butylparaben, have excellent safety, they have insufficient repellent effects against pests such as mites.

Japanese Patent Application Publication No. 8-175906 Japanese Patent Application Publication No. 8-59417 Japanese Patent Application Publication No. 60-008202

An object of the present invention is to provide a pest repellent that is both excellent in safety and highly effective in repelling pests. Another object of the present invention is to provide a method for repelling pests that is both excellent in safety and highly effective in repelling pests.

As a result of intensive studies on pest repellents, the present inventors discovered that hexyl 4-hydroxybenzoate (hexylparaben) has a high repellent effect against pests such as slugs and mites, and it was necessary to complete the present invention. It's arrived.

That is, the present invention provides an insect repellent containing hexyl 4-hydroxybenzoate represented by formula (1).

According to the pest repellent of the present invention, it is not only safe, but also highly effective in repelling pests such as slugs and mites.

It is a photograph of the test area and blank filter paper of Example 3. It is a photograph of the test plot of Comparative Example 5 and a blank filter paper. It is a photograph of the test plot of Comparative Example 6 and blank filter paper.

Hexyl 4-hydroxybenzoate represented by formula (1) used in the present invention may be a commercially available product, for example, as described in Japanese Patent Application No. 2016-240132 previously proposed by the applicant of the present invention. A compound obtained by reacting 4-hydroxybenzoic acid with 1-hexanol in the presence of an acid catalyst may also be used, as shown in FIG.

The pest repellent of the present invention contains hexyl 4-hydroxybenzoate as an active ingredient. Hexyl 4-hydroxybenzoate can be dissolved or dispersed in various solvents, mixed with solid carriers, or adsorbed to produce aerosols, pumps, liquids, coatings, matting agents, sheets, and tapes. It can be prepared in the form of powder, granules, gel, cream, etc., and used as an insect repellent.

Examples of solvents include water, alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, aliphatic hydrocarbons such as hexane, kerosene and paraffin, benzene and toluene. One or more types of aromatic hydrocarbons and esters such as ethyl acetate and hexyl laurate can be used, and among these, water is preferred because it has a low impact on the human body and the environment.

When hexyl 4-hydroxybenzoate is dissolved or dispersed in a solvent to form the pest repellent of the present invention, the content of hexyl 4-hydroxybenzoate in the pest repellent is preferably as low as the mass of the pest repellent. The content is 0.1 to 50% by weight, more preferably 1 to 20% by weight.

Examples of solid carriers include mineral or inorganic powders such as kaolin, talc, bentonite, clay, diatomaceous earth, calcium carbonate, silica, and zeolite; vegetable powders such as wood flour, soy flour, wheat flour, and starch powder; phenolic resins; Plastics such as polyamide, acrylic, and polyester; Synthetic fibers made of such plastics; Rubber such as polybutadiene or its powder; Sublimable powder such as camphor, naphthalene, paradichlorobenzene, trioxane, cyclododecane, and adamantane; Natural fibers such as linters and pulp ; Animal and plant fibers such as wool, cotton, and silk; Regenerated fibers such as rayon, and the like. Further, paper, nonwoven fabric, etc. obtained from inorganic fibers such as glass fiber and asbestos can also be used as the solid carrier.

When hexyl 4-hydroxybenzoate is mixed or adsorbed with a solid carrier to form the pest repellent of the present invention, the content of hexyl 4-hydroxybenzoate in the pest repellent is preferably based on the mass of the pest repellent. is 0.1 to 50% by mass, more preferably 1 to 20% by mass.

The pest repellent of the present invention may contain optional ingredients such as a film forming agent, a surfactant, a wetting agent, a stabilizer, a propellant, a bactericide, a fungicide, a fragrance, and a water/oil repellent, as necessary. May contain A. Examples of the coating film forming agent include ethyl cellulose, hydroxypropyl cellulose, silicone, acrylic resin, chlorinated rubber, petroleum resin, methyl cellulose, vinyl acetate, polyvinyl alcohol, and latex emulsion. Examples of the surfactant include aliphatic monocarboxylate, linear alkylbennesulfonate, alkyl sulfate, sorbitan fatty acid ester, polyoxyethylene alkyl ether, polyethylene glycol fatty acid ester, fatty acid alkanolamide, etc. . Examples of wetting agents include casein, gelatin, alginic acid, carboxymethyl cellulose, and the like. Examples of the propellant include stabilizers such as butylated hydroxyanisole, dibutylated hydroxytoluene, tocopherol, and γ-oryzanol, liquefied petroleum gas, dimethyl ether, fluorocarbon, and compressed gas. Examples of disinfectants include parachloromethoxylate, fragrances include lemon, rose, green, etc., and water and oil repellents include wax, oil, metal soap, and fluorine repellents. Examples include oil agents.

When such optional component A is blended, the blending amount is preferably 0.1 to 5% by mass, more preferably 0.2 to 4% by mass, based on the mass of the pest repellent. Preferably it is 0.5 to 3% by mass. The above-mentioned optional component A can be blended when preparing the above-mentioned dosage form.

The pest repellent of the present invention contains optional component B such as an insecticide, other pest control agent, or repellent in addition to hexyl 4-hydroxybenzoate, if necessary, for the purpose of enhancing the pest repellent effect. You may. Examples of insecticides include pyrethroid insecticides, carbamate insecticides, organophosphorus insecticides, fluorine insecticides, insect growth regulators, etc., and examples of repellents include N-diethyl-m- Examples include toluamide and dimethyl phthalate.

When such optional component B is blended, the blending amount is preferably 1 to 80% by mass, more preferably 5 to 70% by mass, and even more preferably is 8 to 65% by mass. The above-mentioned optional component B can be blended when preparing the above-mentioned dosage form.

Pests repelled by the pest repellent of the present invention include slugs, snails, snails, mites, cockroaches, bees, flies, fly larvae, mosquitoes, horseflies, fleas, centipedes, bedbugs, stable flies, burrs, paramecium, ants, and termites. One or more species selected from the group consisting of , leafhopper, whitefly, whitefly, yellow millipede, pillbug, and whitefly. Among them, one or more species selected from the group consisting of slugs, mites, and termites are preferably repelled, and slugs are more preferably repelled.

By applying the pest repellent of the present invention to the object to be applied or a predetermined part thereof (hereinafter simply referred to as the object to be applied) or the vicinity thereof, pests can be repelled from the object to be applied or the vicinity thereof. Alternatively, the insect repellent may be supported on a carrier such as a nonwoven fabric, a sheet, an inorganic carrier, and the like, and the insect repellent may be installed in a place where it is desired to repel insects.

Examples of applicable objects include the bottom or periphery of flower pots, planters, and seedling pots, between the bottom and the soil, inside drainage holes, under dead leaves, and the like. Furthermore, the objects to which the present invention applies also include the organisms themselves or the surrounding areas of the organisms that can serve as a food source for pests. Examples include agricultural crops themselves, fields where they are grown, orchards, flower beds where flowers are grown, and the like.

In addition, examples of places where pest repellents can be applied indoors include kitchens, washrooms, balconies, storerooms, etc. of general households and dining rooms.

Examples of methods for applying the pest repellent of the present invention to the object include spreading, spraying, and coating. The amount of the pest repellent of the present invention to be applied can be appropriately determined depending on the dosage form of the repellent, the method of application, and the location of application.

In the pest repellent of the present invention, the content of hexyl 4-hydroxybenzoate represented by formula (1) can be appropriately determined depending on the dosage form, application method, and application location of the pest repellent. For example, when used as a liquid such as an aerosol stock solution or a pump agent, the pest repellent preferably contains 0.1 to 50% by mass, more preferably 1 to 20% by mass of hexyl 4-hydroxybenzoate. can be done. In addition, when using the hexyl 4-hydroxybenzoate in the pest repellent by supporting it on a solid carrier such as a non-woven fabric, preferably 0.1% to 50% by mass, more preferably 1 to 30% by mass, even more preferably It can be contained in an amount of 2 to 20% by mass. The solid carrier to be used can be arbitrarily selected, for example, from among the materials listed above, depending on the application location and application method.

[Reference Example 1] Production of hexylparaben (hexyl 4-hydroxybenzoate) 91.2 g of 4-hydroxybenzoic acid was placed in a 300 mL scale four-necked flask (reaction vessel) equipped with a stirrer, temperature sensor, and Dean-Stark device. (0.66 mol), 101.1 g (0.99 mol) of 1-hexanol and 1.8 g of p-toluenesulfonic acid monohydrate as a catalyst were added, and the temperature was raised to 145°C under a nitrogen stream of 38 mL/min. The mixture was reacted at the same temperature for 6 hours to obtain a crude composition containing hexylparaben. After neutralizing it by adding 48% sodium hydroxide, it was purified by distillation to obtain hexylparaben (purity 99.8 wt%).

Tick repellent test [Example 1]
A medium (20 g) in which the test mites were breeding was spread on a 14 x 17 x 2.5 hcm enamel vat and placed in a 5 L plastic airtight container. The humidity inside the container was adjusted to 95-99% with washing water, and the container was stored at a temperature of about 27.0°C.

On 1.30 g of 10 x 10 cm black drawing paper, 1 ml of each test specimen whose concentration was adjusted with acetone so that the concentration of hexylparaben (hexyl 4-hydroxybenzoate) was 0.026% by mass was dropped, and the mixture was air-dried for 10 minutes. After that, the black drawing paper was cut into 2.5 cm square pieces and used as test sections.
As with the test specimens, the area treated only with acetone was used as a blank.

Thirty minutes after placing one sheet of test plot and one sheet of blank paper, the number of mites that had crawled onto the black drawing paper was observed, and the repellency rate was calculated.

[Comparative example 1]
A tick repellent test was conducted in the same manner as in Example 1, except that hexylparaben (hexyl 4-hydroxybenzoate) was replaced with butylparaben (butyl 4-hydroxybenzoate). The results are shown in Table 1.

[Comparative example 2]
A tick repellent test was conducted in the same manner as in Example 1, except that hexylparaben (hexyl 4-hydroxybenzoate) was changed to 2-ethylhexylparaben (2-ethylhexyl 4-hydroxybenzoate). The results are shown in Table 1.

[Comparative example 3]
A tick repellent test was conducted in the same manner as in Example 1, except that hexylparaben (hexyl 4-hydroxybenzoate) was changed to benzylparaben (benzyl 4-hydroxybenzoate). The results are shown in Table 1.

<Mites used in the test>
Mite 1: Dermatophagoides leopard mites Mite 2: Dermatophagoides leopard mites

Slug repellent test [Example 2]
86 g of water was added to an Erlenmeyer flask, and 4 g of agar was added thereto while heating to 100° C. and stirring. Heating was stopped, and 10 g of hexylparaben (hexyl 4-hydroxybenzoate) was added with stirring. After stopping stirring and pouring into a 0.5 L vat cooled with ice, the mixture was cooled for 1 hour to obtain agar containing 10% by mass of hexylparaben.

The resulting agar containing 10% by mass of hexylparaben was spread over half of a tray measuring 140 mm long x 175 mm wide x 14 mm high (treatment area), and food (cat food) was placed in the center of the tray. Ten Chakoura slugs were placed in the remaining part of the tray that was not covered with agar (untreated area), and the tray was wrapped in plastic wrap with small holes and stored in a dark place. The number of slugs in the untreated and treated areas was observed after 6 and 24 hours. A similar test was conducted using agar containing no hexylparaben as a blank. The results are shown in Table 2.

[Comparative example 4]
46 g of water was added to an Erlenmeyer flask, and 4 g of agar was added thereto while heating and stirring at 100°C. Heating was stopped, and 50 g of propylparaben (propyl 4-hydroxybenzoate) was added with stirring. After stopping stirring and pouring into a 0.5 L vat cooled with ice, the mixture was cooled for 1 hour to obtain agar containing 10% by mass of propylparaben.
Thereafter, a test was conducted under the same conditions as in Example 2. The results are shown in Table 2.

Termite repellent test [Example 3]
Aluminum foil folded into a bellows shape was placed in a fume hood, and a qualitative filter paper (ADVANTEC) with a diameter of 55 mm was placed on top of the aluminum foil. 0.4 mL of hexylparaben (hexyl 4-hydroxybenzoate) acetone solution adjusted to 1.8% w/v in advance was evenly dropped onto one side of the filter paper (treatment amount 10% w/w). It was air-dried for 3 hours in a fume hood (hexylparaben-treated filter paper). As a blank, filter paper (blank filter paper) was prepared by dropping only acetone and drying it in the same manner.

One sheet each of the above-mentioned hexylparaben-treated filter paper and blank filter paper were placed in two corners (on the diagonal line) of a stainless steel vat (24 cm x 20 cm x height 3 cm), and 1 mL of tap water was dropped onto each of the filter papers. Thirty domestic termites were released in the center of the vat, and the vat was left at 25°C for 6 days with a plastic bag placed over it for moisture retention and a black plastic bag placed over it to block light. The mass of the hexylparaben-treated filter paper and the blank filter paper was measured, and the mass loss was calculated. The results are shown in Table 3. The greater the weight loss of the filter paper, the more it indicates that the filter paper has been eaten by termites.

[Comparative example 5]
The test was conducted in the same manner as in Example 3 except that hexylparaben was changed to butylparaben. The results are shown in Table 3.

[Comparative example 6]
The test was conducted in the same manner as in Example 3 except that hexylparaben was changed to 4-hydroxybenzoic acid docosyl ester (C22). The results are shown in Table 3.

本発明の好ましい態様は以下を包含する。
〔１〕式（１）
［化１］

で表される４－ヒドロキシ安息香酸ヘキシルを含む害虫忌避剤。
〔２〕害虫が、ナメクジ、カタツムリ、マイマイ、ダニ、ゴキブリ、ハチ、ハエ、ハエ幼虫、蚊、アブ、ノミ、ムカデ、ナンキンムシ、サシバエ、イガ、ゾウリムシ、アリ、シロアリ、ヨコバイ、コナジラミ、スクミリンゴカイ、ヤケヤスデ、ダンゴ虫およびコクヌストモドキからなる群から選択される１種以上である、〔１〕に記載の害虫忌避剤。
〔３〕害虫がナメクジ、ダニおよびシロアリからなる群から選択される１種以上である、〔１〕に記載の害虫忌避剤。
〔４〕〔１〕～〔３〕のいずれかに記載の害虫忌避剤を適用対象物あるいはその周辺に付与することを特徴とする、害虫忌避方法。
〔５〕適用対象物への付与を撒布、噴霧または塗布により行う、〔４〕に記載の害虫忌避方法。

Preferred embodiments of the invention include the following.
[1] Formula (1)
[Chemical formula 1]

A pest repellent containing hexyl 4-hydroxybenzoate represented by:
[2] Pests include slugs, snails, snails, mites, cockroaches, bees, flies, fly larvae, mosquitoes, horseflies, fleas, centipedes, bedbugs, stable flies, burrs, paramecium, ants, termites, leafhoppers, whiteflies, and whiteflies. The pest repellent according to [1], which is one or more species selected from the group consisting of , brown millipedes, pillbugs, and white fleas.
[3] The pest repellent according to [1], wherein the pest is one or more selected from the group consisting of slugs, mites, and termites.
[4] A method for repelling pests, which comprises applying the pest repellent according to any one of [1] to [3] to an object to be applied or its surroundings.
[5] The pest repellent method according to [4], wherein the pest repellent is applied to the object by scattering, spraying, or coating.

Claims (3)

Formula (1)

A pest repellent containing hexyl 4-hydroxybenzoate represented by the formula, wherein the pest is one or more types selected from the group consisting of slugs, mites, and termites . A pest repellent method comprising applying the pest repellent according to claim 1 to an object to be applied or its surroundings. The method for repelling pests according to claim 2 , wherein the application to the object is performed by scattering, spraying or coating.