Self-emulsifying bath composition

Abstract

To provide a self-emulsifiable bath agent composition that gives a moist feel in the bath; has a transparent, uniform and good appearance; and is stable during its storage at high temperature (50°C).SOLUTION: A self-emulsifiable bath agent composition contains component (A): a liquid oil agent, component (B): glycerol, component (C): a diol, component (D): a nonionic surfactant, and component (E): water, with the content of the component (B) being 2 mass% or more and less than 4 mass%, and the mass ratio of the component (C) to the component (B) [(C) / (B)] of 0.48 or more and 1.4 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a self-emulsifying bath composition. [Background technology]

[0002] Self-emulsifying bath agent compositions are known that have self-emulsifying properties and are transparent and uniform before being added to bath water, but can make the bath water cloudy when added to the bath water (for example, Patent Documents 1 and 2). Patent Document 1 discloses that a self-emulsifying, transparent, liquid bath additive contains a higher fatty acid and / or a higher alcohol having a branched or unsaturated structure with 14 or more carbon atoms in the oil component, and that the self-emulsifying, transparent, liquid bath additive, which contains a specified amount or more of the higher fatty acid and / or higher alcohol, has a transparent liquid appearance, instantly forms an O / W emulsion when added to bath water, and has extremely good opacifying performance that gives the bath water a beautiful milky white color with a small amount used. Patent Document 2 discloses that a self-emulsifying bath agent composition containing a hydrocarbon oil that is liquid at 25°C, a specified amount of glycerin, two or more types of nonionic surfactants whose HLB values ​​are within a specified range, and a specified amount of water has excellent long-term storage stability and also has good emulsifying and dispersing properties when added to bath water.

[0003] Self-emulsifying bath agent compositions contain an oily component and therefore have the effect of enhancing the moisturizing properties of the skin, but there is a demand for further improvements in the skin care effects. For example, Patent Document 3 discloses that a bath additive composition containing a polyoxyalkylene polyol isostearate ester of a specific structure, an oily component, and a moisturizing component has high emulsion stability, provides a sufficient moisturizing feeling to the skin even after bathing, and also has excellent stability over time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-331518 A [Patent Document 2] JP 2009-191037 A [Patent Document 3] JP 2007-99644 A Summary of the Invention [Problem to be solved by the invention]

[0005] Bath additives containing a large amount of glycerin, a water-soluble moisturizing component, are expected to improve the moist feeling during bathing. However, when a self-emulsifying bath additive composition containing an oily component contains a large amount of glycerin, there is a problem that the stability of the composition when stored at high temperatures (50°C) (hereinafter also referred to as "high temperature stability") decreases. The technology disclosed in Patent Document 3 examines the emulsion stability when the bath additive composition is poured into a bathtub after aging, but does not examine the appearance of the bath additive composition itself or its storage stability, and it was found that there is room for improvement in this regard.

[0006] The present invention relates to a self-emulsifying bath agent composition that provides a moist feeling in the bath, is transparent and uniform, has a good appearance, and is also stable when stored at high temperatures (50°C). [Means for solving the problem]

[0007] The present inventors have discovered that the above-mentioned problems can be solved by setting the glycerin content within a specified range and by containing a specific mass ratio of diol to glycerin in a self-emulsifying bath agent composition containing a liquid oil, glycerin, a diol, a nonionic surfactant, and water. That is, the present invention provides: Component (A): Liquid oil, Ingredient (B): glycerin, Component (C): Diol, Component (D): a nonionic surfactant, and Component (E): Water, The content of component (B) is 2% by mass or more and less than 4% by mass, The present invention relates to a self-emulsifying bath agent composition in which the mass ratio of component (C) to component (B) [(C) / (B)] is 0.48 or more and 1.4 or less. Effect of the Invention

[0008] According to the present invention, a self-emulsifying bath agent composition can be provided which provides a moist feeling in the bath, is transparent and uniform, has a good appearance, and is also stable at high temperatures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Self-emulsifying bath agent composition] The self-emulsifying bath agent composition of the present invention (hereinafter also simply referred to as the "bath agent composition of the present invention") is Component (A): Liquid oil, Ingredient (B): glycerin, Component (C): Diol, Component (D): a nonionic surfactant, and Component (E): Water, The content of component (B) is 2% by mass or more and less than 4% by mass, The mass ratio of component (C) to component (B) [(C) / (B)] is 0.48 or more and 1.4 or less. By having the above-described configuration, the bath agent composition of the present invention can be a self-emulsifying bath agent composition that provides a moist feeling in the bath, is transparent and uniform, has a good appearance, and has excellent stability when stored at high temperatures (50°C).

[0010] The bath agent composition of the present invention is a transparent, homogeneous liquid bath agent composition containing a liquid oil as component (A), and is a self-emulsifying bath agent composition that, when added to bath water, can make the bath water cloudy by self-emulsifying. It has been found that in a self-emulsifying bath agent composition containing a liquid oil agent of component (A), the transparent uniformity and high-temperature stability of the bath agent composition tend to decrease when the component (B) is contained in a large amount. As a result of intensive research, the present inventors have found that by setting the content of glycerin in component (B) within a predetermined range, containing a hydrophilic component (C) at a predetermined mass ratio relative to component (B), and containing a nonionic surfactant as component (D), the system can be stabilized and separation, precipitation, etc. are unlikely to occur even when water-soluble components such as component (B) and water as component (E) are contained in the oil agent. This action makes it possible to achieve both a moist feeling in the bath and the transparent uniformity and high-temperature stability of the bath agent composition.

[0011] <Component (A): Liquid oil> The bath agent composition of the present invention contains a liquid oil as component (A). In the present invention, "liquid" means that the liquid is in a liquid state at 25°C. Component (A) is not particularly limited as long as it is a liquid oil used in ordinary bath agent compositions, and examples thereof include hydrocarbon oils, silicone oils, ester oils, higher fatty acids, higher alcohols, fluorine-based oils, etc., which are liquid at 25° C. These may be naturally derived oils such as vegetable oils and animal oils.

[0012] Examples of the hydrocarbon oil include linear or branched hydrocarbon oils that are liquid at 25° C., such as liquid paraffin, light liquid isoparaffin, squalane, and squalene. Among these, one or more types selected from the group consisting of liquid paraffin and squalane are preferred from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving high-temperature stability, improving emulsifiability after addition of bath water, and improving moisturizing properties.

[0013] Examples of silicone oils include dimethylpolysiloxane, dimethylcyclopolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, higher alcohol-modified silicone oil, etc., which are liquid at 25° C. Among these, dimethylpolysiloxane is preferred from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving high-temperature stability, improving emulsifiability after addition of bath water, and improving moisturizing properties. The viscosity of the silicone oil at 25°C is preferably 1 mm kinematic viscosity at 25°C from the viewpoint of suppressing excessive volatilization. 2 / s or more, preferably 2 mm 2 / s or more, more preferably 5 mm 2 / s or more, and from the viewpoint of improving emulsification after the bath water is poured in and improving moisture retention, it is preferably 5,000 mm 2 / s or less, preferably 3,000 mm 2 / s or less, and more preferably 1,000 mm 2 / s or less, and even more preferably 400 mm 2 / s or less, and even more preferably 100 mm 2 The kinematic viscosity can be measured, for example, by using an Ubbelohde viscometer.

[0014] Examples of ester oils include fatty acid esters composed of fatty acids and monohydric or dihydric alcohols, glycerin fatty acid esters (glycerides) composed of fatty acids and glycerin, etc. The number of carbon atoms in the fatty acid is preferably 8 or more and 24 or less, more preferably 8 or more and 20 or less, and even more preferably 8 or more and 18 or less, from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving the high-temperature stability, improving the emulsifiability after pouring into bath water, and improving the moisturizing property. Specific examples of ester oils used as component (A) include cetyl octanoate, cetyl isooctanoate, myristyl lactate, cetyl lactate, isopropyl myristate, myristyl myristate, isocetyl myristate, octyldodecyl myristate, isopropyl palmitate, isostearyl palmitate, isopropyl adipate, butyl stearate, isocetyl stearate, isotridecyl isononanoate, decyl oleate, cholesterol isostearate, butyl laurate, isoamyl laurate, and myristate. Fatty acid esters such as methyl, ethyl myristate, ethyl stearate, isononyl isononanoate, isopropyl linoleate, isostearyl isostearate, isopropyl isostearate, methyl oleate, ethyl oleate, oleyl oleate, and ethyl 2-ethylhexanoate; glycerin fatty acid esters (glycerides) such as caprylic / capric triglyceride (INCI name "caprylic / capric triglyceride"), myristate triglyceride, and 2-ethylhexanoate triglyceride; etc.

[0015] Examples of higher fatty acids include fatty acids having 8 to 24 carbon atoms, such as oleic acid, linoleic acid, linolenic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, lanolic acid, and isostearic acid. Examples of higher alcohols include alcohols having 8 to 24 carbon atoms, more preferably 8 to 18 carbon atoms, such as lauryl alcohol, oleyl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, 2-hexyldecanol, 2-octyldodecanol, and cholesterol.

[0016] Examples of fluorine-based oils include fluoropolyethers and perfluoroalkyl ether silicones that are liquid at 25°C.

[0017] Examples of vegetable oils include soybean oil, rice germ oil, rice bran oil, jojoba oil, avocado oil, almond oil, olive oil, cacao butter, sesame oil, persic oil, castor oil, coconut oil, safflower oil, eucalyptus oil, rapeseed oil, and oils obtained by hydrogenating these oils that are liquid at 25°C. Examples of animal oils include mink oil and liquid lanolin.

[0018] The component (A) can be used alone or in combination of two or more. Of the above, from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving its high-temperature stability, improving its emulsifiability after addition of bath water, and improving its moisturizing properties, component (A) is preferably one or more oils selected from the group consisting of hydrocarbon oils, silicone oils, and ester oils, more preferably contains at least one or more oils selected from the group consisting of hydrocarbon oils and ester oils, and even more preferably contains ester oil. From the viewpoints of improving the transparency and uniformity of the bath agent composition, improving the high-temperature stability, improving the emulsification properties after the bath water is poured in, and improving the moisturizing properties, it is more preferable that component (A) contains an ester oil alone or a hydrocarbon oil and an ester oil. The hydrocarbon oil is preferably at least one selected from the group consisting of liquid paraffin and squalane, and the ester oil is preferably at least one selected from the group consisting of isopropyl myristate and caprylic / capric triglyceride. The total content of the hydrocarbon oil and ester oil in component (A) is, from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving its high-temperature stability, improving its emulsifiability after addition of bath water, and improving its moisturizing properties, preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more, and may be 100% by mass.

[0019] The content of component (A) in the bath agent composition is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, from the viewpoint of making the bath agent composition a self-emulsifying type and improving the high-temperature stability. Also, from the viewpoint of stably containing components (C) to (E), the content is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less.

[0020] <Component (B): Glycerin> The bath agent composition of the present invention contains glycerin as component (B). The content of component (B) in the bath agent composition is 2% by mass or more, preferably 2.5% by mass or more, more preferably 2.8% by mass or more, from the viewpoint of improving the moist feeling in the bath. Also, from the viewpoint of improving the transparency uniformity of the bath agent composition and improving the high temperature stability, the content is less than 4% by mass, preferably 3.8% by mass or less, more preferably 3.6% by mass or less.

[0021] <Component (C): Diol> The bath agent composition of the present invention contains a diol as component (C). The diol used as component (C) may be a chain aliphatic diol, an aliphatic diol having an alicyclic structure, or a diol having an aromatic ring, and any of these may be used. From the viewpoint of improving the transparency uniformity of the bath agent composition by having appropriate hydrophilicity, and from the viewpoint of improving high-temperature stability, the number of carbon atoms in component (C) is preferably from 2 to 8, more preferably from 3 to 8, and even more preferably from 3 to 6. From the viewpoint of improving the transparency uniformity of the bath agent composition, from the viewpoint of improving high-temperature stability, and from the viewpoint of use in a bath agent composition, component (C) is preferably a chain aliphatic diol.

[0022] The chain aliphatic diol includes linear or branched aliphatic diols. The chain aliphatic diol used as component (C) may be a chain aliphatic diol having a carbon number of preferably 2 to 8, more preferably 3 to 8, and even more preferably 3 to 6. Examples include ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol (1,3-butylene glycol), 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, and the like, and one or more of these may be used. Of the above, from the viewpoint of improving the transparency and uniformity of the bath agent composition and improving its high-temperature stability, component (C) is preferably one or more selected from the group consisting of propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol (1,3-butylene glycol), 1,4-butanediol, diethylene glycol, and dipropylene glycol, and more preferably one or more selected from the group consisting of propylene glycol, 1,3-butylene glycol, and dipropylene glycol.

[0023] The mass ratio of component (C) to component (B) in the bath agent composition [(C) / (B)] is 0.48 or more, preferably 0.5 or more, more preferably 0.6 or more, even more preferably 0.7 or more, and even more preferably 0.8 or more, from the viewpoint of improving the moist feeling in the bath. Also, from the viewpoint of improving the transparency uniformity of the bath agent composition and the high temperature stability, it is 1.4 or less, preferably 1.3 or less, and more preferably 1.2 or less.

[0024] The content of component (C) in the bath agent composition is not limited as long as the mass ratio [(C) / (B)] is within the above-mentioned range; however, from the viewpoint of improving the transparency and uniformity of the bath agent composition and improving its high-temperature stability, the content is preferably 1.0 mass% or more, more preferably 1.5 mass% or more, even more preferably 1.9 mass% or more, still more preferably 2.5 mass% or more, and is preferably 5.5 mass% or less, more preferably 5 mass% or less, even more preferably 4.6 mass% or less, and still more preferably 4 mass% or less.

[0025] <Component (D): Nonionic surfactant> The bath agent composition of the present invention contains a nonionic surfactant as component (D). Specific examples of component (D) include polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, sucrose fatty acid esters, polyoxyethylene fatty acid esters, polyglyceryl alkyl ethers, fatty acid polyglyceryls, alkyl glucosides, polyoxyethylene alkylamines, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, and polyoxyethylene hydrogenated castor oil, and one or more of these can be used.

[0026] Of the above nonionic surfactants, the alkyl groups in the polyoxyethylene alkyl ethers, polyglyceryl alkyl ethers, alkyl glucosides, and polyoxyethylene alkylamines, the alkenyl groups in the polyoxyethylene alkenyl ethers, and the fatty acids in the sucrose fatty acid esters, polyoxyethylene fatty acid esters, fatty acid polyglyceryls, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene sorbitol fatty acid esters, and polyoxyethylene fatty acid esters, preferably have 8 or more and 22 or less carbon atoms, more preferably 10 or more and 22 or less carbon atoms, even more preferably 12 or more and 20 or less carbon atoms, and still more preferably 14 or more and 20 or less carbon atoms, from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving its high-temperature stability, and improving its emulsifiability after addition of bath water.

[0027] Among the nonionic surfactants, the average number of moles of ethylene oxide added (hereinafter referred to as "average number of moles of EO added") in polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, and polyoxyethylene hydrogenated castor oil is, from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving high-temperature stability, and improving emulsifiability after pouring into bath water, preferably 2 or more, more preferably 3 or more, and even more preferably 5 or more, and is preferably 150 or less, more preferably 80 or less, and even more preferably 60 or less. The average number of moles of EO added is a number average value.

[0028] Among the nonionic surfactants, from the viewpoint of improving the transparency and uniformity of the bath agent composition, improving the high-temperature stability, and improving the emulsifiability after the bath water is poured in, component (D) is preferably one or more selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters, more preferably one or more selected from the group consisting of sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters, and even more preferably sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters. The carbon number of these alkyl groups, alkenyl groups, or fatty acids is preferably 8 to 22, more preferably 10 to 22, even more preferably 12 to 20, and even more preferably 14 to 20.

[0029] Specific examples of polyoxyethylene alkyl ethers include polyoxyethylene lauryl ether, polyoxyethylene myristyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene behenyl ether. Specific examples of sorbitan fatty acid esters include sorbitan monolaurate and sorbitan monooleate. A specific example of the polyoxyethylene alkenyl ether is polyoxyethylene oleyl ether. Specific examples of polyoxyethylene sorbitan fatty acid esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, and polyoxyethylene coconut oil fatty acid sorbitan. Specific examples of polyoxyethylene sorbitol fatty acid esters include polyoxyethylene sorbitol mono-, di-, tri-, or tetra-laurate, polyoxyethylene sorbitol mono-, di-, tri-, or tetra-oleate, and polyoxyethylene sorbitol mono-, di-, tri-, or tetra-stearate.

[0030] From the viewpoints of improving the transparency and uniformity of the bath agent composition, improving its high-temperature stability, and improving its emulsifiability after addition to bath water, component (D) preferably contains a nonionic surfactant (D1) with an HLB of less than 13.0, and more preferably further contains a nonionic surfactant (D2) with an HLB of 13.0 or more. HLB (hydrophilic-lipophilic balance) indicates the ratio of the molecular weight of the hydrophilic group to the total molecular weight of a surfactant, and is calculated by the following Griffin formula. HLB = 20 x [(molecular weight of hydrophilic group contained in surfactant) / (molecular weight of surfactant)]

[0031] From the viewpoint of improving the transparency uniformity of the bath agent composition and improving the high-temperature stability, the HLB of component (D1) is less than 13.0, preferably 12.5 or less, and more preferably 12 or less. In addition, it is preferably 4 or more, more preferably 5 or more, even more preferably 8 or more, and still more preferably 8.5 or more. When component (D1) contains two or more nonionic surfactants, it is preferable to use two or more nonionic surfactants having an HLB within the above range.

[0032] From the viewpoint of improving the emulsifiability of the bath agent composition after it is poured into bath water, the HLB value of the component (D2) is 13.0 or more, preferably 13.2 or more, more preferably 13.5 or more, and is preferably 20 or less, more preferably 18 or less, and even more preferably 16 or less. When component (D2) contains two or more nonionic surfactants, it is preferable to use two or more nonionic surfactants having an HLB within the above range.

[0033] When component (D) contains a nonionic surfactant (D1) having an HLB of less than 13.0 and a nonionic surfactant (D2) having an HLB of 13.0 or more, a preferred combination is one in which component (D1) is one or more selected from the group consisting of sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters, preferably one or more selected from the group consisting of sorbitan monooleate, polyoxyethylene sorbitan monooleate, and polyoxyethylene sorbitan tetraoleate, and component (D2) is one or more selected from the group consisting of polyoxyethylene sorbitan fatty acid esters and polyoxyethylene sorbitan fatty acid esters, preferably one or more selected from the group consisting of polyoxyethylene sorbitan monooleate and polyoxyethylene sorbit tetraoleate.

[0034] The content of component (D) in the bath agent composition is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 12% by mass or more, from the viewpoint of improving the transparency and uniformity of the bath agent composition, improving the high-temperature stability, and improving the emulsifiability after pouring into bath water. From the viewpoint of the degree of freedom in containing other components, the content is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0035] When component (D) contains component (D1), the content of component (D1) in the bath agent composition is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and even more preferably 7% by mass or more, from the viewpoint of improving the emulsifiability of the bath agent composition after pouring into bath water, and is preferably 20% by mass or less, more preferably 18% by mass or less.

[0036] Furthermore, when component (D) contains components (D1) and (D2), the mass ratio of component (D1) to component (D2) [(D1) / (D2)] is, from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving its high-temperature stability, and improving its emulsifiability after addition to bath water, preferably at least 0.1, more preferably at least 0.5, even more preferably at least 0.8, and is preferably at most 20, more preferably at most 18, even more preferably at most 16.

[0037] Furthermore, in the present invention, when two or more types of nonionic surfactants are used as component (D), the HLB of all components (D) is, from the viewpoints of improving the transparency and uniformity of the bath agent composition, improving its high-temperature stability, and improving its emulsifiability after addition to bath water, preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, and is preferably 16 or less, more preferably 15 or less, even more preferably 14 or less. In the present invention, the HLB of the entire component (D) means the HLB of a mixture of two or more nonionic surfactants (hereinafter also referred to as "mixed HLB"). Here, the mixed HLB is a weighted average of the HLB of each nonionic surfactant based on their mass ratio, and is calculated by the following formula: Mixed HLB=Σ(HLBx×Wx) / ΣWx (HLBx indicates the HLB of nonionic surfactant X. Wx indicates the mass (g) of nonionic surfactant X.)

[0038] <Component (E): Water> The bath agent composition of the present invention contains water as component (E). From the viewpoint of improving the transparency uniformity of the bath agent composition and improving the high-temperature stability, the content of component (E) in the bath agent composition is preferably 1% by mass or more, more preferably 1.2% by mass or more, even more preferably 1.5% by mass or more, still more preferably 2% by mass or more, still more preferably 2.2% by mass or more, still more preferably 2.5% by mass or more, and preferably 5% by mass or less, more preferably 4.5% by mass or less, still more preferably 4% by mass or less, still more preferably 3.8% by mass or less, still more preferably 3.5% by mass or less.

[0039] From the viewpoint of improving the moist feeling in the bath, the bath agent composition of the present invention more preferably contains component (B) in an amount of 2.5% by mass or more and less than 4% by mass. Furthermore, from the viewpoints of improving the moist feeling in the bath, improving the transparent uniformity of the bath agent composition, and improving high-temperature stability, it is further preferable that the content of component (B) in the bath agent composition of the present invention is from 2.5% to less than 4% by mass, the content of component (C) is from 1.9% to 4.6% by mass, and the content of component (E) is from 1.2% to 4.5% by mass.

[0040] From the viewpoint of obtaining the effects of the present invention, the total content of components (A) to (E) in the bath agent composition is preferably 50 mass% or more, more preferably 65 mass% or more, even more preferably 70 mass% or more, still more preferably 80 mass% or more, even more preferably 90 mass% or more, and may be 100 mass%.

[0041] The bath agent composition of the present invention may further contain a water-soluble plant extract. The water-soluble plant extract is obtained by extracting the leaves, stems, roots, flowers, fruits, etc. of plants with an aqueous extraction solvent such as water, ethanol, propylene glycol, 1,3-butylene glycol, or a mixture thereof, a 1% urea-containing ethanol solution, a 1,3-butylene glycol solution containing 1% urea, etc. The water-soluble plant extract is not particularly limited and can be appropriately selected depending on the function. Examples of such herbs include chamomile, oat, eucalyptus, carrot, seaweed, butterfly, althea, jute, houttuynia, phellodendron bark, melilot, white lamb, licorice, water-soluble ginger, peony, soapwort, loofah, cinchona, saxifrage, sophora flavescens, water hyacinth, fennel, primrose, rose, rehmannia, lemon, lithospermum, aloe, calamus root, horsetail, sage, thyme, tea, cucumber, yuzu, raspberry, melissa, horse chestnut, peach, peach leaf, mulberry, cornflower, witch hazel, chili pepper, rosemary, asafoetida, angelica tree, clove, quince seed, rose, ginkgo, ginkgo leaf, and the like. One or more of these may be used. The bath agent composition of the present invention can maintain high temperature stability even if it contains as much as 2 mass% or more of glycerin, which is component (B). Because it contains a large amount of glycerin, the composition can maintain high temperature stability even if the content of water, which is component (E), is increased. Therefore, the bath agent composition of the present invention can contain a large amount of water-soluble components such as water-soluble plant extracts.

[0042] <Other ingredients> The bath agent composition of the present invention may contain other components such as surfactants other than component (D), water-soluble polymers such as polyethylene glycol and dextrin, opacifiers such as titanium oxide, preservatives such as sodium benzoate and phenoxyethanol, cooling agents such as menthol, medicinal ingredients other than water-soluble plant extracts, pigments such as Blue No. 1, Blue No. 2, Yellow No. 4, Yellow No. 5, Green No. 3, Green No. 4, Green No. 204, Yellow No. 202, Yellow No. 203, Red No. 106, chlorophyll, riboflavin, crocin, anthraquinone, cochineal, canthaxanthin, and safflower, and fragrances. In addition, as for components that have multiple uses, for example, menthol may be used not only as a cooling agent but also as a fragrance.

[0043] <Dosage form, manufacturing method, etc.> The bath agent composition of the present invention is a transparent, uniform liquid before use, and after being poured into bath water, it quickly disperses in the bath water, making the bath water cloudy. There are no particular limitations on the method for producing the bath agent composition of the present invention, and the composition can be prepared by blending and mixing the above-mentioned components in a conventional manner. EXAMPLES

[0044] The present invention will be described below with reference to examples, but the present invention is not limited to the scope of the examples.

[0045] Examples 1 to 11 and Comparative Examples 1 to 5 (Preparation and Evaluation of Self-emulsifying Bath Agent Compositions) A self-emulsifying bath agent composition was prepared by blending and mixing the components in the amounts shown in Tables 1 and 2. The content (mass %) of each component shown in Tables 1 and 2 is the active amount. The bath agent compositions were also evaluated for appearance, high temperature stability, and moist feeling in the bath using the following methods. The results are shown in Tables 1 and 2. The bath agent compositions of the Examples and Comparative Examples were confirmed to be of a self-emulsifying type, as they became cloudy after being poured into bath water.

[0046] <Appearance of the bath agent composition> After preparing each bath agent composition, it was allowed to stand at room temperature (25° C.) for 2 hours, and the appearance was visually observed and evaluated according to the following criteria. Evaluation Criteria 3: Transparent and uniform 2: No separation or precipitation, but opaque 1: Separation or precipitation is observed

[0047] <High temperature stability of bath agent composition> A transparent container was filled with about 40 mL of each example of the bath agent composition and sealed, and then left to stand in a thermostatic chamber at 50° C. for 6 days. The appearance was then visually observed and evaluated according to the following criteria. Evaluation Criteria 3: Transparent and uniform 2: No separation or precipitation, but opaque 1: Separation or precipitation is observed

[0048] <Moisturizing feeling while bathing> 1 g of each bath agent composition was dissolved in 5 L of hot water at 40°C, and five expert panelists immersed their forearms in the bath water and evaluated the moist feeling during the bath according to the following criteria. The average scores of the five panelists are shown in Tables 1 and 2. The higher the value, the more moist the feeling during the bath. 3: High moisturizing effect while bathing 2: Feels moist in the bath (practically acceptable level) 1: No moist feeling in the bath

[0049] [Table 1]

[0050] [Table 2]

[0051] *1 Liquid paraffin: "Kaidor" manufactured by Sonneborn, LLC *2 Tri(caprylic / capric acid)glyceryl: "Coconard MT" manufactured by Kao Corporation *3 Isopropyl myristate: Kao Corporation's "Excepearl IPM" *4 Squalane: "NIKKOL Refined Olive Squalane" manufactured by Nippon Surfactant Industries Co., Ltd. *5 Sorbitan fatty acid ester: Kao Corporation's "Emersol Super L-10", sorbitan monolaurate *6 Polyoxyethylene (6) sorbitan monooleate: "Rheodor TW-O106V" manufactured by Kao Corporation *7 Polyoxyethylene (40) tetraoleate sorbitol: "Rheodol 440V" manufactured by Kao Corporation *8 Polyoxyethylene (60) tetraoleate sorbitol: "Rheodol 460V" manufactured by Kao Corporation *9 Polyoxyethylene (20) sorbitan monooleate: Kao Corporation's "Rheodor TW-O120V" *10 Phenoxyethanol: "Neoron PH 100" manufactured by The Dow Chemical Company [Industrial Applicability]

[0052] According to the present invention, there can be provided a self-emulsifying bath agent composition that provides a moist feeling in the bath, is transparent and uniform, has a good appearance, and is also excellent in high-temperature stability. The self-emulsifying bath agent composition of the present invention can maintain high-temperature stability despite containing a large amount of glycerin.

Claims

1. Component (A): liquid oil, Component (B): glycerin, Component (C): diol, Component (D): a nonionic surfactant, and Component (E): Water, The content of component (B) is 2% by mass or more and less than 4% by mass, The content of component (E) is 1.2% by mass or more and 5% by mass or less, The self-emulsifying bath agent composition has a mass ratio of component (C) to component (B) [(C) / (B)] of 0.48 or more and 1.4 or less, and has a self-emulsifying property that emulsifies and disperses when added to bath water, causing the bath water to become cloudy.

2. 2. The self-emulsifying bath composition according to claim 1, wherein component (A) is at least one oil selected from the group consisting of hydrocarbon oils, silicone oils, and ester oils.

3. 3. The self-emulsifying bath composition according to claim 1 or 2, wherein component (D) comprises a nonionic surfactant (D1) having an HLB of less than 13.

0.

4. The self-emulsifying bath agent composition according to any one of claims 1 to 3, wherein component (C) is at least one selected from the group consisting of propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, and dipropylene glycol.

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