JP7465086B2 - Pest repellent composition - Google Patents

Description

The present invention relates to a pest repellent composition.

Pests, for example, flying pests such as mosquitoes and flies, are a cause of infectious diseases and dermatitis by transmitting pathogens to animals such as humans. In particular, some mosquitoes are insects that are extremely harmful from the viewpoint of hygiene because they transmit pathogens such as dengue fever, Zika fever, yellow fever, encephalitis, and malaria.
Conventionally, methods of spraying insecticides or applying repellents to the skin surface have been widely used to protect against such flying pests, and DEET (N,N-diethyltoluamide) is a typical example of such a repellent.

Pests such as mosquitoes have chemical receptor systems, such as thermoreceptors that detect the body temperature of animals, olfactory receptors that detect volatile substances such as body odor, and carbon dioxide receptors that detect carbon dioxide, which enable them to detect animals. DEET repels such pests by modulating the chemical receptor systems possessed by such pests and neutralizing their cognitive senses.
However, DEET has an unpleasant odor, and in order to achieve a sufficient and sustained repellent effect, it is necessary to mix it in at a certain amount or more.Furthermore, it is known to cause allergies and rough skin in some people, so there is a problem that the amount and frequency of use is limited for young children and people with sensitive skin.

The use of natural essential oils as repellent ingredients is therefore being considered. Natural essential oils such as citronella oil, lemon eucalyptus oil, lemongrass oil, orange oil and cassia oil are also used in candles and aroma lotions, and are highly safe for humans. However, the lasting repellent effect of these oils against pests is not sufficient, and there are questions about their practicality.

Various other proposals have been made so far regarding repellents and repellent compositions for pests.
For example, Patent Document 1 describes the incorporation of an insect repellent such as DEET into a skin protective agent containing a fluorine-polyether co-modified silicone and an ultraviolet protection component. Patent Document 2 describes a flying insect repellent that uses natural essential oils such as citronella oil and lemongrass oil and can suppress the flight and blood-sucking behavior of pests even at low concentrations. Patent Document 3 discloses a pest repellent volatilization composition that contains a specific amount of citronellal as a pest repellent component.

Japanese Patent Application Laid-Open No. 8-59447 JP 2002-173407 A JP 2003-201203 A

Among pest repellents, those that are applied to the skin are desired to be safe and have little odor, and furthermore, to have not only an initial repellent effect but also an excellent durability of the repellent effect, etc. However, the current situation is that the major pest repellents that are available do not fully meet these demands.
As mentioned above, existing pest repellents such as DEET described in Patent Document 1 have an unpleasant odor and also have safety issues for the human body, so there is a demand for repellents that can be used more safely by young children and people with sensitive skin.
The flying insect repellent described in Patent Document 2 and the pest repellent volatile composition described in Patent Document 3 have a spatial repellent effect against pests such as flying insects, and have different preferred formulations and required characteristics from pest repellent compositions that are applied to human skin.
In pest repellents applied to human skin, it is desirable to improve the durability of the repellent effect, considering the skin environment where moisture such as sweat and waste products are mixed. However, in repellents using natural essential oils, while increasing the content of natural essential oils is expected to improve the repellent effect and its durability, there is a problem that the odor is too strong and it becomes unbearable for practical use.
At present, no composition has been found that has an excellent and sustained pest repellent effect, is safe, suppresses the strong odor derived from the repellent component, and is suitable for application to the skin.

The objective of the present invention is to provide a pest repellent composition that has an excellent and long-lasting repellent effect against pests, particularly flying pests, is safe, has a reduced strong odor derived from the repellent components, and is suitable for application to the skin.

As a result of intensive research, the present inventors have found that a non-volatile liquid oily component having a specific surface tension and viscosity has an effect of repelling pests such as mosquitoes, but there is room for further research on the duration of the repellent effect when actually used on human skin.Therefore, they have found that when an existing repellent essential oil such as citronella oil is contained in an amount that does not cause odor problems and is combined with a non-volatile liquid oily component having a specific surface tension and viscosity, the repellent effect is extended while suppressing odor.In other words, they have found that a pest repellent composition containing a specific amount of a non-volatile liquid oily component having a specific surface tension and viscosity and an existing repellent essential oil such as citronella oil can solve the above problem.
That is, the present invention provides the following [1] to [7].
[1] A pest repellent composition or a pest retention and inhibition composition comprising the following components (A) and (B):
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C as measured by a B-type rotational viscometer: 13% by mass or more and 99.995% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil: 0.005% by mass or more and 15% by mass or less. [2] An oil-in-water mosquito repellent composition or mosquito retention inhibition composition comprising the following components (A) to (C), in which the content of pest repellents other than components (A) and (B) is 10% by mass or less:
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C as measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil: 0.005% by mass or more and 15% by mass or less; (C) water: 35% by mass or more and 86.995% by mass or less. [3] An oil-in-water mosquito repellent composition or mosquito retention control composition comprising the following components (A) to (C), wherein the mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of pest repellents other than components (A) and (B) is 10% by mass or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.0 (C) Water: 35% by mass or more and 86.995% by mass or less [4] An oil-in-water mosquito repellent composition or mosquito retention inhibition composition comprising the following components (A) to (C), in which the mass ratio of component (B) to component (A) [(B)/(A)] is 0.0001 or more and 0.5 or less, the mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of any pest repellent other than components (A) and (B) is 10 mass% or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.0 (C) Water: 35% by mass or more and 86.995% by mass or less [5] An oil-in-water mosquito repellent composition or mosquito retention inhibition composition comprising the following components (A) to (D), in which the mass ratio of component (B) to component (A) [(B)/(A)] is 0.0001 or more and 0.5 or less, the mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of any pest repellent other than components (A) and (B) is 10 mass% or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, and hydrocarbon oils, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.005% by mass or more and 15% by mass or less; (C) water: 35% by mass or more and 86.995% by mass or less; (D) thickener: 0.05% by mass or more and 3% by mass or less. [6] A method for repelling insects, comprising applying any one of the compositions [1] to [5] to a human skin surface.
[7] A method for inhibiting the retention of pests, comprising attaching the composition according to any one of [1] to [5] to the legs of a pest to prevent the pest from retaining on human skin.

The present invention can provide a pest repellent composition, a pest retention suppression composition, a pest repellent method, and a pest retention suppression method that are safe, have excellent long-lasting repellent effects against pests, particularly flying pests, and suppress strong odors derived from repellent components, and are suitable for application to the skin.

[Pest repellent composition, pest retention and suppression composition]
The pest repellent composition and pest retention/inhibition composition of the present invention (hereinafter, these are also collectively referred to as "the composition of the present invention") are compositions containing the following components (A) and (B).
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 99.995% by mass or less (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil: 0.005% by mass or more and 15% by mass or less

The composition of the present invention contains specific amounts of components (A) and (B), has excellent long-lasting repellent effects against pests, particularly flying pests, suppresses the strong odor caused by the repellent components, and is suitable for application to the skin.

In the present invention, "repellent effect against pests" means that even if a pest comes into contact with an object, it does not stay there but immediately leaves, and the composition of the present invention corresponds to a contact repellent composition. That is, the pest repellent effect in the present invention is different from repellents or insect repellents that repel pests without contacting the object, such as those that keep pests away from the object or those that prevent pests from approaching the object, and insecticides that have an insecticidal effect against pests and exterminate them.
The composition of the present invention has an effect of repelling pests, because even if pests such as mosquitoes land on the object to which it is applied or attached, the pests do not remain there but immediately leave. Specifically, it has a retention-inhibiting effect of preventing pests such as mosquitoes from remaining in a specific area on the skin surface for a time to insert their stingers, specifically 1 second or more, after landing on the skin of an animal such as a human. Such an effect is based on a pest repellent principle that has not been seen in the past, and is safe without side effects such as rough skin. Therefore, the composition of the present invention can be used as a pest retention-inhibiting composition.
In the present invention, the "long-lasting repellent effect against pests" means that the repellent effect continues even after time has passed after the composition of the present invention is applied to an object. In the following description, the long-lasting repellent effect, particularly against flying pests, in the present invention will be simply referred to as the "long-lasting repellent effect."

The composition of the present invention contains, as component (A), one or more non-volatile liquid oily components selected from the group consisting of (a) silicone oil, (b) ester oil, (c) ether oil, (d) hydrocarbon oil, (e) aliphatic alcohol, and (f) polyhydric alcohol, each of which has a surface tension of 40 mN/m or less at 25° C. and a viscosity of 400 mPa·s or less at 23° C. as measured by a B-type rotational viscometer. By containing component (A), the composition has an excellent long-lasting repellent effect against pests, particularly flying pests. The reason for this is unclear, but is thought to be as follows.
The present inventors have found that flying pests such as mosquitoes have the property of avoiding staying on a surface where their legs become wet in order to avoid the attractive force generated from the landing surface when their legs become wet. Since the legs of flying pests such as mosquitoes are hydrophobic, a liquid oily component with a surface tension of 40 mN/m or less at 25°C has a high affinity with the legs of flying pests, and a liquid oily component with a viscosity of 400 mPa·s or less will have a sufficiently large contact area between the legs of the flying pest and the liquid oily component in a short time when the legs of the flying pest come into contact with the liquid oily component. Therefore, when a flying pest lands on a surface to which component (A) is applied or attached, the legs become wet, and it is considered that the flying pest flies away without staying at the landing point in order to avoid the attractive force generated from the landing surface.
In the present invention, landing refers to a flying pest such as a mosquito contacting an object for less than one second, whereas stationary refers to a flying pest such as a mosquito remaining in contact with an object for one second or more.

Furthermore, with component (A) alone, the composition of the present invention still has room for improvement in terms of providing a sufficient sustained repellent effect in practical use situations. Therefore, by further containing a specific amount of component (B) (described below) in addition to component (A) and applying component (B) together with component (A) to the legs of flying pests, it is believed that it has been possible to achieve an excellent sustained repellent effect while reducing the odor derived from component (B).

<Component (A): Non-volatile liquid oily component>
Component (A) contained in the composition of the present invention is one or more non-volatile liquid oily components selected from the group consisting of (a) silicone oils, (b) ester oils, (c) ether oils, (d) hydrocarbon oils, (e) aliphatic alcohols, and (f) polyhydric alcohols, each of which has a surface tension of 40 mN/m or less at 25° C. and a viscosity of 400 mPa·s or less at 23° C. as measured by a B-type rotational viscometer.

From the viewpoints of facilitating application to the skin and improving the sustained repellent effect, component (A) is preferably a non-volatile oil that is liquid at 20°C, more preferably liquid at 15°C, and even more preferably liquid at 10°C.
In addition, the "liquid" in the liquid oily ingredient means that it is determined to be liquid in the liquid-solid determination test according to the American Society for Testing and Materials standard "ASTM D 4359-90: Standard Test Method for Determining Whether a Material is a Liquid or Solid."
From the viewpoint of improving the sustained repellent effect against pests, component (A) is preferably a water-insoluble or poorly water-soluble component, and specifically, the amount of solubility in 100 g of water at 20°C is preferably 1 g or less, more preferably 0.5 g or less, even more preferably 0.1 g or less, and even more preferably essentially 0 g.

The liquid oily component of component (A) used in the present invention is a non-volatile liquid oily component from the viewpoint of improving the repellency duration effect. Here, the non-volatile liquid oily component in the present invention refers to a liquid oily component whose volatilization rate after drying at 25°C for 60 minutes under 1 atmosphere is 50% or less, and preferably refers to a liquid oily component whose volatilization rate after drying at 25°C for 120 minutes under 1 atmosphere is 50% or less. The volatilization rate is evaluated according to the German test standard DIN53249, and specifically, is performed according to the following steps 1 to 4.
1. Measure the weight (P(g)) of a round filter paper with a diameter of 150 mm.
2. Using a pipette, a 0.3 g sample of component (A) is dropped onto a round filter paper, and immediately thereafter the weight (W ₀ (g)) of the filter paper is measured.
3. In a ventilated environment, measure the weight of the filter paper at 25° C. at 5-minute intervals using a gravimetric measurement accurate to about 0.001 g. The weight of the filter paper measured 60 minutes after the measurement in 2 is defined as W ₆₀ (g).
4. The value calculated using the formula {((W ₀ - P) - (W ₆₀ - P))/(W ₀ - P)} x 100 is the volatility rate (%).
The lower the volatility rate, the longer the liquid oily component will remain on the skin when applied, resulting in a longer lasting repellent effect.
When two or more kinds of liquid oily components are used, the volatility of the liquid oily components means the volatility of the mixture of two or more kinds of liquid oily components. Therefore, as long as the volatility of the mixture is within the above range, liquid oily components having a volatility of more than 50% after drying at 25°C for 60 minutes under 1 atmosphere may be used in combination.

From the viewpoint of availability, the surface tension of component (A) at 25° C. is preferably 15 mN/m or more, more preferably 17 mN/m or more, and from the viewpoint of improving the sustained repellent effect, it is 40 mN/m or less, preferably 30 mN/m or less, more preferably 28 mN/m or less, even more preferably 25 mN/m or less, still more preferably 23 mN/m or less, and still more preferably 21 mN/m or less. Even if the surface tension of the component (A) itself at 25° C. exceeds 40 mN/m, it will exhibit a sustained repellent effect if the surface tension is lowered by mixing it with another liquid oily component.
The viscosity of component (A) at 23°C as measured by a B-type rotational viscometer is preferably 1 mPa·s or more from the viewpoint of suppressing volatility and improving the repellent sustaining effect, and is preferably 400 mPa·s or less from the viewpoint of improving the repellent sustaining effect, preferably 300 mPa·s or less, more preferably 210 mPa·s or less, even more preferably 100 mPa·s or less, still more preferably 60 mPa·s or less, still more preferably 40 mPa·s or less, and still more preferably 30 mPa·s or less. When two or more liquid oily components with different viscosities are used, the viscosity means the viscosity of a mixture of these liquid oily components.
The surface tension and viscosity of component (A) are measured by the method described in the Examples.

(a) Silicone Oil As the silicone oil, from the viewpoint of improving the sustained repellent effect, one or more types selected from the group consisting of dimethylpolysiloxane, dimethiconol (dimethylpolysiloxane having a hydroxy group at the terminal), methylphenylpolysiloxane, modified silicone, and cyclic silicone are preferable.
Examples of modified silicones include amino-modified silicones (dimethylpolysiloxanes having an amino group), polyether-modified silicones, glyceryl-modified silicones, amino derivative silicones, carboxy-modified silicones, fatty acid-modified silicones, alcohol-modified silicones, aliphatic alcohol-modified silicones, epoxy-modified silicones, fluorine-modified silicones, and alkyl-modified silicones.

Among the silicone oils, from the viewpoint of improving the sustained repellent effect, one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, methylphenylpolysiloxane, and modified silicone are preferred, one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, and polyether modified silicone are more preferred, and dimethylpolysiloxane is even more preferred.

The dimethylpolysiloxane may be one or more selected from the group consisting of linear dimethylpolysiloxane and cyclic dimethylpolysiloxane. Of these, linear dimethylpolysiloxane is more preferred from the viewpoint of improving the sustained repellent effect.
Commercially available examples of linear dimethylpolysiloxanes include the KF-96 series from Shin-Etsu Chemical Co., Ltd., the SH200C series from Dow Corning Toray Co., Ltd., "2-1184 Fluid," and "Silsoft DML,""Element14 PDMS 5-JC,""Element14 PDMS 10-JC," and "Element14 PDMS 20-JC" from Momentive Performance Materials.

(b) Ester Oil From the viewpoint of improving the repellent effect, the ester oil is preferably an ester oil represented by any one of the following general formulas (1) to (3), or a dialkyl carbonate compound represented by the following general formula (4).

R ¹ -COO-R ² (1)
In general formula (1), ^R1 represents a linear or branched alkyl group having from 7 to 23 carbon atoms, or an aromatic hydrocarbon group having from 6 to 24 carbon atoms, which may be substituted with a hydroxyl group, and ^R2 represents a linear or branched alkyl group or an alkenyl group having from 1 to 22 carbon atoms.
When ^R1 is an alkyl group, from the viewpoint of improving the sustained repellent effect, the carbon number is preferably 7 or more, more preferably 9 or more, and from the viewpoint of providing a good feel when applied to the skin, the carbon number is preferably 21 or less, more preferably 17 or less. When ^R1 is an aromatic hydrocarbon group, the carbon number is preferably 8 or more, more preferably 10 or more, and from the viewpoint of providing a good feel when applied to the skin, the carbon number is preferably 22 or less, more preferably 20 or less.
From the viewpoint of providing a good feel when applied to the skin, ^R2 is preferably a linear or branched alkyl or alkenyl group having a carbon number of 20 or less, more preferably 18 or less. From the viewpoint of providing a good feel when applied to the skin, it is preferable that at least one of ^R1 and ^R2 is a branched alkyl group.

Examples of ester oils represented by general formula (1) include myristyl 2-ethylhexanoate, cetyl 2-ethylhexanoate, stearyl 2-ethylhexanoate, isodecyl octanoate, isocetyl octanoate, isononyl isononanoate, isotridecyl isononanoate, cetearyl isononanoate, octyl propylheptanoate, methyl laurate, isopropyl myristate, octyldodecyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, isocetyl palmitate, and stearin. Examples of the hydroxystearate include 2-ethylhexyl stearate, isocetyl stearate, isotridecyl stearate, isopropyl isostearate, octyl isostearate, isocetyl isostearate, isostearyl isostearate, 2-ethylhexyl hydroxystearate, methyl oleate, oleyl oleate, isobutyl oleate, oleyl erucate, alkyl benzoate (alkyl carbon number 12 to 15), and diethylhexyl naphthalenedicarboxylate.

( ^R3O ) _-CH2CH ( ^OR4 ) _-CH2 ( ^OR5 ) (2)
In formula (2), R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a group represented by the following formula (2-1), provided that all of them are not hydrogen atoms.
-CO-R ⁶ (2-1)
(In the formula, ^R6 represents an alkyl or alkenyl group having 7 to 23 carbon atoms, preferably 17 or less, which may be substituted with a hydroxyl group.)
The ester oil represented by the general formula (2) may be one or more selected from the group consisting of glyceryl tri-2-ethylhexanoate and glyceryl tricaprylate. These may also be plant-derived ester oils such as jojoba oil, olive oil, sunflower oil, soybean oil, peanut oil, rapeseed oil, almond oil, palm oil, coconut oil, castor oil, wheat germ oil, grape seed oil, thistle oil, evening primrose oil, macadamia nut oil, corn germ oil, and avocado oil.

R ⁷ O-(AO)m-COR ⁸ (3)
In formula (3), ^R7 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, ^R8 represents an alkyl or alkenyl group having 1 to 23 carbon atoms, AO represents an alkyleneoxy group having 2 to 4 carbon atoms, and m represents the average number of moles added of 1 to 50.
^R7 preferably has 6 or more carbon atoms from the viewpoint of improving the sustained repellent effect, and preferably is an aromatic hydrocarbon group having 12 or less carbon atoms, more preferably 10 or less carbon atoms, more preferably a benzyl group, from the viewpoint of improving the feel when applied to the skin.
^R8 is an alkyl group having preferably 7 or more carbon atoms, more preferably 11 or more carbon atoms, from the viewpoint of improving the sustained repellent effect, and preferably 21 or less carbon atoms, more preferably 15 or less, from the viewpoint of providing a good feel when applied to the skin.
From the viewpoint of improving the sustained repellent effect, the AO group is preferably a propyleneoxy group, and from the viewpoint of improving the sustained repellent effect and from the viewpoint of providing a good feel when applied to the skin, m is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less.
Examples of the ester oil represented by the general formula (3) include one or more selected from the group consisting of an ester of a 3-mol propylene oxide adduct of benzyl alcohol and myristic acid ("Croda" Crodamol STS) and an ester of a 3-mol propylene oxide adduct of benzyl alcohol and 2-ethylhexanoic acid ("Croda" Crodamol SFX).

R ⁹ —O—(CH ₂ CH ₂ O) v —CO—(OCH ₂ CH ₂ ) w —OR ¹⁰ (4)
In formula (4), R ⁹ and R ¹⁰ each independently represent an alkyl or alkenyl group having 6 to 22 carbon atoms, and v and w each independently represent 0 or the average number of moles added of 1 to 50.
^R9 and ^R10 each preferably have 8 or more carbon atoms from the viewpoint of improving the sustained repellent effect, and each preferably represents an alkyl group having 18 or less carbon atoms, more preferably 12 or less carbon atoms, from the viewpoint of providing a good feel when applied to the skin.
From the viewpoint of providing a good feel when applied to the skin, v and w are preferably 0 or a number between 1 and 5, and more preferably 0.
Examples of the dialkyl carbonate compound represented by the general formula (4) include dioctyl carbonate ("Cetyolic Acid CC" manufactured by Cognis).

Examples of ester oils other than those mentioned above include esters of polyvalent carboxylic acids and alcohols, and esters of polyhydric alcohols other than glycerin and fatty acids.
Specific examples thereof include one or more selected from the group consisting of diisopropyl dimerate, diisopropyl adipate, diethoxyethyl succinate, 2-ethylhexyl succinate, propanediol dicaprate, neopentyl glycol dicaprate, neopentyl glycol di-2-ethylhexanoate, etc. Among these, from the viewpoint of improving the sustained repellent effect, esters of neopentyl glycol and fatty acids are preferred, and one or more selected from the group consisting of neopentyl glycol dicaprate and neopentyl glycol di-2-ethylhexanoate are more preferred.
Of the above (b) ester oils, at least one selected from the group consisting of ester oils represented by general formula (1) and esters of neopentyl glycol and fatty acids is preferred.

(c) Ether Oil As the ether oil, from the viewpoint of improving the repellent effect, a dialkyl ether compound represented by the following general formula (5) or a polyoxyalkylene alkyl ether compound represented by the following general formula (6) is preferable.

R ¹¹ -O-R ¹² (5)
In formula (5), R ¹¹ and R ¹² each independently represent a linear or branched alkyl or alkenyl group having 6 to 22 carbon atoms, or an aromatic hydrocarbon group having 6 to 24 carbon atoms.
R ¹¹ and R ¹² are preferably an alkyl group from the viewpoint of improving the repellent duration effect, and the number of carbon atoms therein is preferably 8 or more from the viewpoint of improving the repellent duration effect, and is preferably 18 or less, more preferably 16 or less, and even more preferably 12 or less, from the viewpoint of improving the feel when applied to the skin.
Examples of the dialkyl ether compound represented by the general formula (5) include dihexyl ether, dioctyl ether ("Cetyl OE" manufactured by Cognis), dicaprylyl ether, and cetyl-1,3-dimethylbutyl ether ("ASE-166K" manufactured by Kao Corporation).

R ¹³ —O—(PO)r(EO)s—H (6)
In the general formula (6), ^R13 represents an alkyl group or an alkenyl group having 6 to 22 carbon atoms, PO represents a propyleneoxy group, and EO represents an ethyleneoxy group. r represents an average number of moles added of 0.1 to 15, and s represents an average number of moles added of 0 to 10. When s is not 0, the addition form of PO and EO may be random or block.
The number of carbon atoms in ^R13 is preferably 8 or more from the viewpoint of improving the sustained repellent effect, and is preferably 20 or less, more preferably 18 or less, and even more preferably 12 or less, from the viewpoint of improving the feel when applied to the skin.
From the viewpoint of improving the sustained repellent effect, the average number of added moles r is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, and from the viewpoint of improving the feel when applied to the skin, it is preferably 13 or less, more preferably 10 or less, and the average number of added moles s is preferably 5 or less, more preferably 1 or less, and even more preferably 0, from the viewpoint of improving the feel when applied to the skin.
The polyoxyalkylene alkyl ether compound represented by the general formula (6) is preferably at least one selected from the group consisting of polypropylene glycol, polyoxypropylene octyl ether, polyoxypropylene decyl ether, and polyoxypropylene lauryl ether, each of which has an average added mole number r of propyleneoxy groups of 3 or more and 10 or less.
Among the above (c) ether oils, the ether oil represented by the general formula (5) is preferred from the viewpoint of improving the sustained repellent effect.

(d) Hydrocarbon Oils Examples of the hydrocarbon oils include liquid paraffin, liquid isoparaffin, squalane, isohexadecane, isoeicosane, hydrogenated polyisobutene, light liquid isoparaffin, heavy liquid isoparaffin, α-olefin oligomers, and cycloparaffin.
Among these, from the viewpoint of improving the sustained repellent effect and from the viewpoint of providing a good feel when applied to the skin, one or more selected from the group consisting of liquid paraffin, liquid isoparaffin, and squalane are preferred.

(e) Aliphatic alcohols Examples of the aliphatic alcohol include monohydric chain or cyclic aliphatic alcohols, and from the viewpoint of improving the repellent duration effect, monohydric chain aliphatic alcohols are preferred. The carbon number of the aliphatic alcohol is preferably 14 or more, more preferably 18 or more, on average, from the viewpoint of improving the repellent duration effect, and is preferably 28 or less, more preferably 24 or less, and even more preferably 22 or less, from the viewpoint of improving the feel when applied to the skin.
The aliphatic alcohol may be either straight-chain or branched, and may be either saturated or unsaturated. From the viewpoint of improving the sustained repellent effect and of providing a good feel when applied to the skin, a branched-chain aliphatic saturated alcohol is preferred.
Examples of the straight chain aliphatic alcohols include oleyl alcohol, and examples of the branched chain aliphatic saturated alcohols include butyl octanol, butyl decanol, hexyl decanol, and octyldodecanol.
Among these, from the viewpoint of improving the sustained repellent effect and from the viewpoint of providing a good feel when applied to the skin, branched chain aliphatic saturated alcohols are preferred, and one or more selected from the group consisting of hexyldecanol, hexyldodecanol, and octyldodecanol are preferred.

(f) Polyhydric Alcohols Examples of polyhydric alcohols include aliphatic alcohols having 2 or more carbon atoms, aromatic alcohols, and sugar alcohols having 4 or more carbon atoms, and may be either saturated or unsaturated. From the viewpoint of providing a good feel when applied to the skin, one or more types selected from the group consisting of aliphatic alcohols having 2 to 10 carbon atoms, aromatic alcohols, and sugar alcohols having 4 to 10 carbon atoms are preferred.
Among the polyhydric alcohols, examples of aliphatic alcohols having 2 or more carbon atoms include dihydric alcohols such as ethylene glycol, propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,2-pentanediol, 1,2-hexanediol, diethylene glycol, dipropylene glycol, and hexylene glycol.
Examples of the sugar alcohol include sorbitol, erythritol, pentaerythritol, xylitol, and mannitol.

Among the liquid oily components, from the viewpoint of improving the repellent effect, one or more selected from the group consisting of (a) silicone oil, (b) ester oil, (c) ether oil, (d) hydrocarbon oil, and (f) polyhydric alcohol are preferred, one or more selected from the group consisting of (a) silicone oil, (b) ester oil, and (d) hydrocarbon oil are more preferred, one or more selected from the group consisting of (a) silicone oil and (d) hydrocarbon oil are even more preferred, and (a) silicone oil is even more preferred. Among (a) silicone oil, from the viewpoint of improving the repellent effect, one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, methylphenylpolysiloxane, and modified silicone are preferred, one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, and polyether modified silicone are more preferred, dimethylpolysiloxane is even more preferred, and linear dimethylpolysiloxane is even more preferred.

(Content of component (A))
The content of component (A) in the composition of the present invention is 13% by mass or more, preferably 20% by mass or more, more preferably 25% by mass or more, from the viewpoint of improving the repellent duration effect, from the viewpoint of suppressing the odor derived from component (A), from the viewpoint of improving the usability of the composition, and from the viewpoint of ensuring the long-term storage stability of the composition, it is 99.995% by mass or less, preferably 80% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and even more preferably 35% by mass or less. The content of component (A) in the composition of the present invention is 13 to 99.995% by mass, preferably 13 to 80% by mass, more preferably 13 to 50% by mass, even more preferably 20 to 50% by mass, even more preferably 20 to 40% by mass, and even more preferably 25 to 35% by mass.

<Component (B): Repellent Essential Oil>
The composition of the present invention contains, as component (B), one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil. Here, eucalyptus oil refers to repellent essential oils including eucalyptol oil and lemon eucalyptol oil. "Repellent essential oil" refers to essential oils that have a pest repellent effect. For example, citronella oil, lemongrass oil, and eucalyptol oil are approved as repellent ingredients in Thailand, and catnip oil is approved in the United States. Also, peppermint oil is widely used as a repellent ingredient.
The term "repellent essential oil" includes essential oils obtained by extracting, distilling, or squeezing the components contained in plants, as well as synthetic essential oils produced artificially. For example, citronella oil is obtained from Cymbopogon nardus or Cymbopogon winterianus, lemongrass oil from Cymbopogon citratus, eucalyptus oil from Eucalyptus L'Heritier spp. such as Eucalyptus citriodora, peppermint oil from Mentha sp. such as Mentha × piperita and Mentha canadensis, and catnip oil from Nepeta sp. such as Nepeta cataria.
Citronella oil may be, for example, that disclosed in R. Tisserand et al., "Essential Oil Safety-E-Book: A Guide for Health Care Professionals", Second Edition (2014), p. 251, and the International Fragrance Association (IFRA). Hereinafter, the composition of citronella oil will be described as an example based on the description in the above "Essential Oil Safety-E-Book: A Guide for Health Care Professionals".
Citronella ceyron type
Citronellal 5.2-46.8% by weight
Geraniol 16.8-29.1% by mass
(-)-Citronellol 3.0-21.8% by mass
Citronella Java type
Citronellal 34.8-42.8% by mass
Geraniol 22.1-25.4% by mass
(-)-Citronellol 9.7-11.5% by mass

Component (B) is an existing repellent essential oil, and its repellent effect is well known. However, if it is contained in the composition at more than 15% by mass, the pest repellent effect is good, but a strong odor derived from component (B) is emitted, and it may cause skin trouble such as rash. On the other hand, if the content of component (B) in the composition is 15% by mass or less, the strong odor derived from component (B) is suppressed, but the sustained pest repellent effect tends to decrease. Therefore, even if the content of component (B) in the composition of the present invention is 15% by mass or less, by using it in combination with component (A), it is possible to ensure the sustained repellent effect and safety while suppressing the strong odor derived from component (B).
Component (B) may contain one type alone or two or more types. Among component (B), from the viewpoint of improving the repellent effect, one or more repellent essential oils selected from citronella oil, lemongrass oil, eucalyptus oil, and catnip oil are preferred, and one or more repellent essential oils selected from citronella oil, lemongrass oil, and catnip oil are more preferred.

(Content of Component (B))
The content of component (B) in the composition of the present invention is 0.005% by mass or more, preferably 0.006% by mass or more, more preferably 0.008% by mass or more, from the viewpoint of improving the repellent duration effect and suppressing the odor derived from component (A). The content of component (B) in the composition of the present invention is 15% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 2% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.08% by mass or less, from the viewpoint of suppressing the strong odor and skin trouble derived from component (B). The content of component (B) in the composition of the present invention is 0.005 to 15% by mass, preferably 0.006 to 10% by mass, more preferably 0.006 to 5% by mass, even more preferably 0.006 to 2% by mass, even more preferably 0.006 to 1% by mass, even more preferably 0.006 to 0.5% by mass, and even more preferably 0.008 to 0.08% by mass.

In addition, it is preferable that the composition of the present invention contains components (A) and (B) as repellent components for pest repellency, and does not contain effective amounts of other pest repellents, from the viewpoint of preventing allergies and rough skin in users.
The composition of the present invention has a sustained pest repellent effect even if it does not contain an effective amount of a pest repellent other than component (A) and component (B). In other words, even if the composition of the present invention contains an existing pest repellent other than component (A) and component (B) in an amount less than the effective lower limit, if the pest does not remain in place even after landing, the retention suppression effect of the present invention is expressed. In other words, the composition of the present invention does not need to substantially contain a pest repellent other than component (A) and component (B).

Here, "not containing an effective amount of" a pest repellent other than component (A) and component (B) generally means that the content of a pest repellent other than component (A) and component (B) in the composition of the present invention is preferably 10 mass% or less, more preferably 6 mass% or less, even more preferably 4 mass% or less, still more preferably 3 mass% or less, still more preferably 2 mass% or less, and even more preferably 1 mass% or less.
The effective amount of existing pest repellents other than component (B) can also be determined by referring to the minimum effective amount published by the manufacturers of each repellent product. For example, among existing pest repellents other than component (B), the effective amount of DEET (N,N-diethyltoluamide) is 4% by mass or more. Therefore, in the present invention, a content of N,N-diethyltoluamide of 3% by mass or less is one of the preferred embodiments of the present invention, and 1% by mass or less is more preferred.

The effective amount of an existing pest repellent can also be measured by the repellency evaluation test described below.
(Repellency evaluation test)
One hundred mated female mosquitoes (Aedes albopictus) are placed in a plastic cage (30 x 30 x 30 cm: BugDorm-1 cage) surrounded by mesh. A rectangular cut of 5 cm length x 4 cm width is made about 15 cm from the wrist part toward the elbow side of a Qualatech super long glove (50 cm) (AS ONE Corporation, Catalog number: 3-6432-02) and the arm is inserted into the glove. Without applying anything to the exposed part from the cut, the arm is inserted into the cage and it is confirmed that the mosquitoes land on two exposed parts of the skin within two minutes and remain there for more than one second. If the mosquito does not remain there for more than one second, a new mosquito is prepared. Hereinafter, a stay of one second or more is simply referred to as a stay.
The test of the evaluation sample, which is a solution of the pest repellent, is carried out by adjusting the concentration with ethanol so that the evaluation sample can be applied to exposed skin (5 cm x 4 cm) at 2 mg/ ^cm2 .
Using a pipette, apply the adjusted concentration solution to the exposed area so that it is spread over the entire exposed area (amount of solution required: 40-50 μl). Leave it for 3 minutes and then start the test.
The test is performed by inserting the arm coated with the evaluation sample into the cage for 2 minutes and counting the number of times the arm stays there. The test is terminated when the arm stays there twice in total, and the arm is inserted for 2 minutes every 30 minutes until the end of the test. If the second stay occurs at 30 minutes, the duration of the repellent effect is determined to be 0 minutes, and if the second stay occurs at 60 minutes, the duration of the repellent effect is determined to be 30 minutes. The test is performed on three subjects, and the average duration of the repellent effect is calculated.
In this test, the concentration of the pest repellent that shows an average duration of the repellent effect of 2 hours or more can be regarded as the effective concentration (effective amount) of the pest repellent.
Since the composition of the present invention has a sustained repellent effect even without containing an effective amount of a pest repellent other than component (A) and component (B), it is more preferable that the composition does not substantially contain a pest repellent other than component (A) and component (B) from the viewpoint of suppressing unpleasant odors or strong odors derived from the pest repellent and from the viewpoint of preventing skin troubles. The content of the pest repellent other than component (A) and component (B) in the composition of the present invention is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.01% by mass or less, and even more preferably substantially 0% by mass.

Examples of existing pest repellents other than component (A) and component (B) include, in addition to the above-mentioned DEET, known pest repellent compounds such as icaridin, dimethyl phthalate, 2-ethyl-1,3-hexanediol, p-menthane-3,8-diol, carane-3,4-diol, di-n-butyl succinate, hydroxyanisole, rotenone, 3-(acetylbutyl)aminopropionic acid ethyl ester, citronellol, α-pinene, geraniol, citronellal, camphor, linalool, and 2-undecanone, as well as repellent essential oils other than component (B).

In the composition of the present invention, the mass ratio of component (B) to component (A) [(B)/(A)] is preferably 0.0001 or more, more preferably 0.0002 or more, from the viewpoint of improving the repellent effect and suppressing the odor derived from component (A), and is preferably 0.8 or less, more preferably 0.5 or less, even more preferably 0.05 or less, still more preferably 0.005 or less, and even more preferably 0.0005 or less, from the viewpoint of suppressing the odor. The mass ratio of component (B) to component (A) [(B)/(A)] is preferably 0.0001 to 0.8, more preferably 0.0001 to 0.5, even more preferably 0.0002 to 0.05, still more preferably 0.0002 to 0.005, and even more preferably 0.0002 to 0.0005.

<Component (C): Water>
From the viewpoint of improving the repellent duration effect and from the viewpoint of providing a composition with good usability, the composition of the present invention preferably contains water as component (C). The content of component (C) in the composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 35% by mass or more, and even more preferably 50% by mass or more, from the viewpoint of improving the repellent duration effect and from the viewpoint of providing a composition with good usability. Also, from the viewpoint of improving the repellent duration effect, it is preferably 86.995% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, and even more preferably 75% by mass or less. The content of component (C) in the composition is preferably 5 to 86.995% by mass, more preferably 5 to 85% by mass, even more preferably 10 to 80% by mass, even more preferably 35 to 75% by mass, and even more preferably 50 to 75% by mass.

The present invention can be applied to various composition forms, for example, non-aqueous compositions not containing water, water-in-oil compositions, oil-in-water compositions, etc. From the viewpoint of suppressing odors derived from component (A), it is preferable to use an oil-in-water composition. In addition, when using an oil-in-water composition, the content of component (C) in the composition is preferably 35% by mass or more, more preferably 40% by mass or more, and even more preferably 45% by mass or more. In addition, from the viewpoint of improving the repellent effect, it is preferably 86.995% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.
In addition, from the viewpoint of improving the repellent effect, it is preferable to use a water-in-oil type composition. When using a water-in-oil type composition, the content of component (C) in the composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of improving the feel when applied to the skin. In addition, from the viewpoint of improving the repellent effect and the long-term storage stability of the composition, it is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less.

When the composition of the present invention contains component (C), the mass ratio of component (A) to component (C) [(A)/(C)] is preferably 0.05 or more, more preferably 0.1 or more, and even more preferably 0.2 or more from the viewpoint of improving the repellent effect, and from the same viewpoint, it is preferably 20 or less, more preferably 10 or less, even more preferably 5 or less, and even more preferably 1 or less. The mass ratio of component (A) to component (C) [(A)/(C)] is preferably 0.05 to 20, more preferably 0.1 to 10, even more preferably 0.1 to 5, even more preferably 0.2 to 5, and even more preferably 0.2 to 1.

<Component (D): Thickener>
The composition of the present invention may further contain a thickener as component (D). From the viewpoint of improving the repellent effect by adjusting the fluidity after application to the skin, from the viewpoint of ensuring excellent application to the skin by dispersing or dissolving each component well, and from the viewpoint of ensuring the long-term storage stability of the composition, the thickener is preferably one having a suitable emulsifying ability (i.e., surface activity). In the present invention, the agent having emulsifying ability and thickening effect is defined as a thickener.
Examples of component (D) include water-soluble cationic polymers, anionic polymers, nonionic polymers, and amphoteric or dipolar polymers.

The content of component (D) in the composition of the present invention is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, from the viewpoints of improving the sustained repellent effect, of ensuring excellent application to the skin by well dispersing or dissolving each component, and of ensuring the long-term storage stability of the composition, and from the similar viewpoints, is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less. When the composition of the present invention contains a thickener having surface-active properties, the content of other surfactants in the composition is preferably 1.5% by mass or less, and more preferably 1% by mass or less.

<Other ingredients>
The composition of the present invention may contain other components than those mentioned above, such as surfactants, preservatives, colorants, repellents, repellent essential oils other than component (B), moisturizers, fragrances, pH adjusters, etc., as appropriate, within the scope of not impairing the effects of the invention. It may also contain medicinal or physiologically active components such as vitamins, blood circulation promoters, active oxygen scavengers, anti-inflammatory agents, whitening agents, and bactericides. It may also be used for other purposes, such as using fragrances as bactericides.

The composition of the present invention can be produced by a conventional method. For example, it can be produced by mixing components (A) and (B) and, if necessary, component (C), a thickener, a surfactant, a volatile oil, etc., and stirring them using a known device.

There are no particular limitations on the pests that the composition of the present invention can repel, but it is more effective against flying pests.
"Flying pests" refer to pests that approach humans and other animals while flying and suck blood from their skin, pests that transmit pathogenic bacteria while flying without sucking blood, and pests that cause discomfort to humans by flying themselves.
Specific examples of flying pests include mosquitoes such as Culex pipiens quinquefasciatus, Culex tritaeniorhynchus, Culex pipiens molestus, and Culex quinquefasciatus; mosquitoes such as Aedes aegypti, Aedes albopictus, Anopheles sinensis, Aedes togoi, Anopheles gambiae, and Anopheles stephensis; midges such as Chironomidae and Chironomidae akamusi; black flies such as Juniperus quinquefasciatus, Juniperus quinquefasciatus, and Juniperus acutus; house flies, Musca domestica, and Musca domestica. Flies such as house flies, little house flies, black flies, flesh flies, seed flies, onion flies, fruit flies, Drosophila melanogaster, moth flies, Chichewa flies, and stable flies; horse flies such as black flies, horse flies, deer flies, and spotted flies; midges such as Tokunaga black midge, Oshima midge, and chicken midge; and bees such as Japanese yellow hornets, Japanese paper wasps, and honeybees.
Among these, the composition of the present invention is particularly excellent in long-lasting repellent effect against mosquitoes, and is particularly excellent in long-lasting repellent effect against Culex pipiens pallens, Culex tritaeniorhynchus, Culex pipiens molestus, Culex quinquefasciatus, Aedes aegypti, and Aedes albopictus, among the above-mentioned mosquitoes.

[Methods for repelling and suppressing pests]
The method for repelling pests of the present invention is carried out by applying the pest repellent composition of the present invention to the surface of human skin.
The method for inhibiting retention of pests of the present invention is to prevent pests from retaining on human skin by attaching the pest retention inhibiting composition of the present invention to the legs of pests, particularly flying pests. Hereinafter, these methods are collectively referred to as "methods of the present invention".

Here, "applying to the surface of the skin" includes not only directly applying the composition to the surface of the skin with the hands or the like, but also attaching the composition to the surface of the skin by spraying or the like.
The amount of the composition applied to the skin surface is preferably 0.1 mg or more, more preferably 0.2 mg or more, and even more preferably 0.25 mg or more per ¹ cm2 from the viewpoint of improving the sustained repellent effect. The upper limit of the application amount is preferably 10 mg or less, more preferably 8 mg or less, and even more preferably 5 mg or less per ¹ cm2 from the viewpoint of suppressing stickiness and economic efficiency.

From the viewpoint of providing a repellent composition that has an excellent and sustained mosquito repellent effect, is safe, suppresses the strong odor derived from the repellent components, and is excellent in usability, the composition of the present invention is preferably an oil-in-water mosquito repellent composition or mosquito retention inhibition composition that contains the following components (A) to (C) and has a content of pest repellents other than components (A) and (B) of 10 mass % or less:
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, eucalyptol oil, peppermint oil, and catnip oil: 0.005% by mass or more and 15% by mass or less; (C) water: 35% by mass or more and 86.995% by mass or less.

From the viewpoint of providing a repellent composition that has an excellent and sustained mosquito repellent effect, is safe, suppresses the strong odor derived from the repellent components, and is excellent in usability, the composition of the present invention is preferably an oil-in-water mosquito repellent composition or mosquito retention inhibition composition that contains the following components (A) to (C), in which the mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of pest repellents other than components (A) and (B) is 10 mass% or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.005% by mass or more and 15% by mass or less; (C) water: 35% by mass or more and 86.995% by mass or less.

From the viewpoint of providing a repellent composition that has an excellent and sustained mosquito repellent effect, is safe, suppresses the strong odor derived from the repellent components, and is excellent in usability, the composition of the present invention is preferably an oil-in-water mosquito repellent composition or mosquito retention inhibition composition, which contains the following components (A) to (C), in which the mass ratio of component (B) to component (A) [(B)/(A)] is 0.0001 or more and 0.5 or less, the mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of pest repellents other than components (A) and (B) is 10 mass% or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.005% by mass or more and 15% by mass or less; (C) water: 35% by mass or more and 86.995% by mass or less.

From the viewpoint of providing a repellent composition that has an excellent and sustained mosquito repellent effect, is safe, suppresses the strong odor derived from the repellent components, and is excellent in usability, the composition of the present invention is preferably an oil-in-water mosquito repellent composition or mosquito retention inhibition composition, which contains the following components (A) to (D), in which the mass ratio of component (B) to component (A) [(B)/(A)] is 0.0001 or more and 0.5 or less, the mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of pest repellents other than components (A) and (B) is 10 mass% or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, and hydrocarbon oils, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.005% by mass or more and 15% by mass or less; (C) water: 35% by mass or more and 86.995% by mass or less; (D) thickener: 0.05% by mass or more and 3% by mass or less.

The pest repelling method of the present invention is a method for repelling pests by preventing pests such as mosquitoes from remaining on the spot even if they land on an object to which the composition of the present invention has been applied or attached. Specifically, the composition has a retention suppression effect in which pests such as mosquitoes do not remain on the surface of an animal's skin for a period of time after landing on the skin of an animal such as a human, such as for a period of time that they can insert their stingers, specifically for example for one second or more. This effect is based on a novel pest repelling principle, and is safe with no side effects such as rough skin.

In relation to the above-mentioned embodiment, the present invention further discloses the following embodiments.
＜1＞
An oil-in-water type pest repellent composition or pest retention/inhibition composition comprising the following components (A) and (B), wherein the mass ratio of component (B) to component (A) [(B)/(A)] is 0.0001 or more and 0.8 or less:
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C measured by a B-type rotational viscometer: 13% by mass or more and 99.995% by mass or less (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil: 0.005% by mass or more and 15% by mass or less <2>
The composition according to <1>, wherein the mass ratio of the component (B) to the component (A) [(B)/(A)] is 0.0002 or more, preferably 0.0003 or more, and 0.5 or less, preferably 0.05 or less, more preferably 0.005 or less, and even more preferably 0.0005 or less.
＜3＞
The composition according to <1> or <2>, wherein the content of pest repellents other than the component (A) and the component (B) is 10% by mass or less, preferably 6% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, still more preferably 2% by mass or less, and even more preferably 1% by mass or less.
＜4＞
The composition according to <3>, wherein the pest repellent other than the component (A) and the component (B) is DEET.
＜5＞
The composition according to any one of <1> to <4>, wherein the surface tension of component (A) at 25°C is 15 mN/m or more, preferably 17 mN/m or more, and 30 mN/m or less, preferably 28 mN/m or less, more preferably 25 mN/m or less, even more preferably 23 mN/m or less, and still more preferably 21 mN/m or less.
＜6＞
The composition according to any one of <1> to <5>, wherein the viscosity of component (A) at 23°C as measured with a B-type rotational viscometer is 1 mPa·s or more and 300 mPa·s or less, preferably 210 mPa·s or less, more preferably 100 mPa·s or less, even more preferably 60 mPa·s or less, still more preferably 40 mPa·s or less, and still more preferably 30 mPa·s or less.
＜７＞
The composition according to any one of <1> to <6>, wherein the component (A) is one or more oils selected from the group consisting of silicone oils, ester oils, ether oils, and hydrocarbon oils, preferably one or more oils selected from the group consisting of silicone oils, ester oils, and hydrocarbon oils, more preferably one or more oils selected from the group consisting of silicone oils and hydrocarbon oils, and even more preferably silicone oils.
＜8＞
The composition according to any one of <1> to <7>, wherein the content of the component (A) is 20% by mass or more, preferably 25% by mass or more, and 80% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less.
＜9＞
The composition according to any one of <1> to <8>, wherein the component (B) is one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil, preferably one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, and catnip oil, and more preferably one or more repellent essential oils selected from the group consisting of citronella oil and lemongrass oil.
＜10＞
The composition according to any one of <1> to <9>, wherein the content of component (B) is 0.006% by mass or more, preferably 0.008% by mass or more, and is 10% by mass or less, preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and still more preferably 0.08% by mass or less.

<11>
The composition according to any one of <1> to <10>, comprising water as component (C).
＜12＞
The composition according to <11>, wherein the content of the component (C) is 5% by mass or more, preferably 10% by mass or more, more preferably 35% by mass or more, even more preferably 50% by mass or more, and is 86.995% by mass or less, preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.
＜13＞
The composition according to <11> or <12>, which is an oil-in-water composition, has a content of component (C) in the composition of preferably 35% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, and is preferably 86.995% by mass or less, preferably 80% by mass or less, more preferably 75% by mass or less.
＜14＞
The composition according to <11> or <12>, which is a water-in-oil composition, and the content of component (C) in the composition is 5 mass% or more, preferably 10 mass% or more, more preferably 15 mass% or more, and is 40 mass% or less, preferably 30 mass% or less, more preferably 25 mass% or less.
＜15＞
The composition according to any one of <11> to <14>, wherein the mass ratio of the component (A) to the component (C) [(A)/(C)] is 0.05 or more, preferably 0.1 or more, more preferably 0.2 or more, and is 20 or less, preferably 10 or less, more preferably 5 or less, and even more preferably 1 or less.
＜16＞
The composition according to any one of <1> to <15>, further comprising a thickener in an amount of preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.
＜１７＞
A mosquito repellent composition or mosquito retention and inhibition composition of an oil-in-water type, comprising the following components (A) to (C), in which the content of pest repellents other than components (A) and (B) is 10 mass% or less:
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25° C. and a viscosity of 400 mPa·s or less at 23° C. as measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil: 0.005% by mass or more and 15% by mass or less (C) water: 35% by mass or more and 86.995% by mass or less <18>
A mosquito repellent composition or mosquito retention inhibition composition of an oil-in-water type, comprising the following components (A) to (C), the mass ratio of component (A) to component (C) [(A)/(C)] being 0.2 or more and 5 or less, and the content of pest repellents other than components (A) and (B) being 10 mass% or less:
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25° C. and a viscosity of 400 mPa·s or less at 23° C. as measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.005% by mass or more and 15% by mass or less (C) water: 35% by mass or more and 86.995% by mass or less <19>
A mosquito repellent composition or mosquito retention inhibition composition of an oil-in-water type, comprising the following components (A) to (C): a mass ratio of component (B) to component (A) [(B)/(A)] is 0.0001 or more and 0.5 or less, a mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of any pest repellent other than components (A) and (B) is 10 mass% or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25° C. and a viscosity of 400 mPa·s or less at 23° C. as measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.005% by mass or more and 15% by mass or less; (C) water: 35% by mass or more and 86.995% by mass or less <20>
A mosquito repellent composition or mosquito retention inhibition composition of an oil-in-water type, comprising the following components (A) to (D): a mass ratio of component (B) to component (A) [(B)/(A)] is 0.0001 or more and 0.5 or less, a mass ratio of component (A) to component (C) [(A)/(C)] is 0.2 or more and 5 or less, and the content of pest repellents other than components (A) and (B) is 10 mass% or less.
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, and hydrocarbon oils, each having a surface tension of 40 mN/m or less at 25° C. and a viscosity of 400 mPa·s or less at 23° C. as measured by a B-type rotational viscometer: 13% by mass or more and 50% by mass or less (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, and catnip oil: 0.005% by mass or more and 15% by mass or less (C) water: 35% by mass or more and 86.995% by mass or less (D) thickener: 0.05% by mass or more and 3% by mass or less <21>
A method for repelling pests, comprising applying the composition according to any one of <1> to <20> to a human skin surface.
＜22＞
A method for inhibiting retention of a pest, comprising applying the composition according to any one of <1> to <20> to legs of a pest to prevent the pest from retaining on human skin.

The present invention will be described below with reference to examples, but the present invention is not limited to the scope of the examples. In the examples, various measurements and evaluations were performed by the following methods.

(Surface tension of liquid oily component)
The surface tension of the liquid oily component is measured in an environment of 25° C. by the Wilhelmy method using a platinum plate, using an automatic surface tensiometer "Tensiometer K100" (KRUSS).

(Viscosity of Liquid Oily Component)
A Viscometer TVB-10 manufactured by Toki Sangyo Co., Ltd. was used as a B-type rotational viscometer according to JIS K7117-1:1999. The viscosity values of the components to be measured vary greatly for each sample, so it is difficult to accurately measure all of them under one set of measurement conditions. Therefore, measurements were performed using two types of rotors. The viscosity was first measured using rotor M2 at a rotation speed of 12 rpm in a 23°C environment. At this time, components with a viscosity of 2500 mPa·s or more were measured again at a rotation speed of 6 rpm to obtain the viscosity value.
On the other hand, the components having a viscosity of 20 mPa·s or less were measured again using an L adapter, which is a rotor for low viscosity, at a rotation speed of 30 rpm in a 23° C. environment to obtain viscosity values.

(Evaluation of sustained repellent effect against pests)
(I) Preparation of Aedes albopictus The Aedes albopictus mosquitoes used were prepared by rearing Aedes albopictus eggs purchased from Sumitomo Technoservice Co., Ltd. in a cage at room temperature under conditions of 27° C. and a relative humidity (RH) of 60% and allowing them to grow into adults.
A transparent plastic pan was filled with water to a depth of about 1 cm, and the filter paper on which the purchased eggs were laid was placed in the pan, and the pupae were allowed to hatch. The hatched pupae were then fed tropical fish food (Tetramine) daily as larval food. After one week, the pupae were collected with a dropper, transferred to a 20 mL plastic cup, and transferred to a cage covered with a net. The pupae were fed 10% by mass sucrose in a 25 mL plastic tube as adult food. After emergence, males and females were reared in the same cage for five days to allow mating. After five days of rearing, the adults were collected using an aspirator, anesthetized on ice for five minutes, and then visually separated into males and females, and only the females were collected and used for evaluation.

(II) Measurement of Repellent Effect Duration Approximately 100 female Asian tiger mosquitoes were transferred to a plastic cage (30 x 30 x 30 cm) and the test was carried out under conditions of 27°C and 60% relative humidity (RH). A hole of 4 x 5 cm was made in the forearm part of a rubber glove large enough to cover the subject's arm, and the composition of each example was uniformly applied to give a concentration of 2 mg/ ^cm2 .
Then, to activate the Asian tiger mosquitoes, the breath was blown into the plastic cage for 5 seconds. The test was performed by placing the forearm immediately after applying the composition into the plastic cage, exposing the Asian tiger mosquitoes for 2 minutes, and counting the number of mosquitoes that stayed on the cage.
The test was terminated when the subject stayed on the surface twice in total, and the subject was exposed for 2 minutes every 30 minutes until the end of the test. If the subject stayed on the surface twice during the 30th minute of exposure, the duration of the repellent effect was determined to be 0 minutes, and if the subject stayed on the surface twice during the 60th minute of exposure, the duration of the repellent effect was determined to be 30 minutes. The test was performed on three subjects, and the average duration of the repellent effect was calculated.

(Evaluation of odor intensity)
The test product was applied to a 4.5 x 4.5 cm surface on the inner side of a human forearm to an area of 2 mg/ ^cm2 . Immediately after that, the odor intensity was determined by sensory evaluation by three evaluators. The odor intensity was evaluated on a six-level scale (5: strong odor, 4: strong odor, 3: easily detectable odor, 2: weak odor that is easy to understand, 1: barely detectable odor, 0: odorless), and the average value of the evaluations by the three evaluators was taken as the odor intensity. The odor intensity suitable for application to the skin was classified as follows. The smaller the value, the better the composition.
A: 2.5 or less B: More than 2.5 and less than 3.5 C: More than 3.5

(Evaluation of Long-Term Storage Stability)
80 mL of each composition was placed in a 100 mL glass bottle, sealed, and stored at 50° C. for one month. The presence or absence of separation of the oil phase in the composition was then visually confirmed and ranked according to the following criteria.
A: No change.
B: The oil phase is united, and some seepage from the emulsion to the surface is observed.
C: Separation of the oil phase is observed.

Examples 1 to 36 and Comparative Examples 1 to 9 (Production and Evaluation of Compositions)
The components shown in Table 1 were mixed in the amounts shown in Tables 2 to 7, and the mixture was stirred for 2 minutes at 8,000 rpm using a T.K. Robomix (Tokushu Kika Kogyo Co., Ltd.) in which the stirring section was replaced with a T.K. Homomixer MARKII2.5 type, to obtain an oil-in-water composition for each example. The designations (A) to (D) in the table correspond to the components (A) to (D) in this specification, respectively. The amounts listed in Tables 2 to 7 are the amount of active ingredient (mass%) of each component. The obtained compositions were used to carry out various evaluations by the above-mentioned methods. The results are shown in Tables 2 to 7.

From Tables 2 to 7, it can be seen that the compositions of the present invention (Examples 1 to 36) containing the specified amounts of components (A) and (B) have a pest repellent time of 2 hours or more, have an excellent repellent effect, and suppress the odor caused by the repellent components.

The present invention can provide a pest repellent composition, a pest retention suppression composition, a pest repellent method, and a pest retention suppression method that are safe, have excellent long-lasting repellent effects against pests, particularly flying pests, and suppress strong odors derived from repellent components, and are suitable for application to the skin.

Claims (3)

A pest repellent composition comprising the following components (A) and (B):
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C as measured by a B-type rotational viscometer: 13% by mass or more and 99.995% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil: 0.005% by mass or more and 5% by mass or less. A pest repellent composition having an N,N-diethyltoluamide content of 3% by mass or less. A pest retention and inhibition composition comprising the following components (A) and (B):
(A) one or more non-volatile liquid oily components selected from the group consisting of silicone oils, ester oils, ether oils, hydrocarbon oils, aliphatic alcohols, and polyhydric alcohols, each having a surface tension of 40 mN/m or less at 25°C and a viscosity of 400 mPa·s or less at 23°C as measured by a B-type rotational viscometer: 13% by mass or more and 99.995% by mass or less; (B) one or more repellent essential oils selected from the group consisting of citronella oil, lemongrass oil, eucalyptus oil, peppermint oil, and catnip oil: 0.005% by mass or more and 5% by mass or less. A pest retention and inhibition composition having an N,N-diethyltoluamide content of 3% by mass or less. The composition according to claim 1 or 2, wherein component (A) is one or more selected from the group consisting of silicone oil, ester oil, and hydrocarbon oil.