Cloudy bathing agent

Abstract

To provide a cloudy bathing agent excellent in cloudiness, storage stability and the like even when a large amount of glycerin / polyglycerin and an oily raw material are both formulated.SOLUTION: The cloudy bathing agent contains the following components (A) to (C): (A) a polyglycerol fatty acid ester having 1 mol of fatty acid added thereto, (B) glycerol and / or polyglycerol, and (C) an oily raw material, wherein the average HLB of a surfactant in the cloudy bathing agent is more than 4.7, the content of the component (B) in the cloudy bathing agent is ≥8 mass%, and the content of the component (C) in the cloudy bathing agent is>30 mass%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cloudy bath additive that has excellent cloudiness and storage stability even when it contains a large amount of glycerin / polyglycerin and oily ingredients. [Background technology]

[0002] Bath additives are generally preparations that are added to the bathtub water. Depending on the user and the season, bath additives are required to have various effects, such as a warming effect after bathing, a fatigue and pain relief effect by stimulating metabolism, a relaxing effect, a cleansing effect, a refreshing effect, and a moisturizing effect, and bath additives containing various ingredients according to these effects are commercially available (Non-Patent Document 1).

[0003] Among these, bath additives that are expected to have a moisturizing effect after bathing generally contain moisturizing ingredients (moisturizing ingredients) such as oily ingredients like ceramides and rice germ oil, glycerin, and plant extracts (Non-Patent Document 2). Among the moisturizing ingredients, it has been reported that adding 250 mL of glycerin to 1,400 L of bath water (twice a week for 8-9 months) significantly increased the skin moisture content of the lateral forearm, and significantly reduced the incidence, number of skin disease sites, and number of prescribed medications (Non-Patent Document 3). Based on these findings, it can be said that adding glycerin to bath water can be expected to have a high moisturizing effect on the skin.

[0004] On the other hand, among bath additives, those that make bathwater cloudy when used are popular because they give a feeling of "elegance" and "luxury" and have relaxing and soothing effects such as "peace of mind" and "calmness" (Non-Patent Document 4). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Japan Bath Salts Industry Association, Home Page > About Bath Salts > Effects and Mechanisms of Bath Salts [Searched July 5, 2024], Internet<URL: https: / / www.jbia.org / knowledge3.html> [Non-patent document 2] Japan Bath Salts Industry Association, Home Page > About Bath Salts > Ingredients and Types of Bath Salts [Searched July 5, 2024], Internet<URL: https: / / www.jbia.org / knowledge2.html> [Non-patent document 3] Junichi Iiyama, Kazuyoshi Kawahira, Changes in Skin Properties and Prevention of Skin Diseases in Severely Physically and Mentally Disabled People by Bathing with Glycerin, Journal of the Japanese Society of Balneology, Climatology and Physical Medicine, Vol. 71, No. 3, May 2008, pp. 173-179 [Non-patent document 4] Takamatsu, Mamoru et al., Study on Quantifying the Psychological Effects of Bathing Using the Hue of Aqueous Solutions, Journal of the Japan Society of Kansei Engineering, Vol. 8, No. 3, pp. 799-804, 2009 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, glycerin is expected to have a high moisturizing effect, but when incorporated in large amounts, the turbidity of bath water decreases, making it difficult to incorporate it in large amounts into cloudy bath additives. Furthermore, oily ingredients are components that can improve turbidity in addition to moisturizing effects, but when incorporated in large amounts, the storage stability of the formulation decreases, and the oil phase and the aqueous phase tend to separate during storage. In other words, currently, there is a lack of cloudy bath additives that contain large amounts of glycerin and oily ingredients and yet have excellent turbidity and storage stability. The present invention has been made to solve these problems, and aims to provide a cloudy bath additive that is excellent in turbidity, storage stability, etc., even when containing large amounts of both glycerin / polyglycerin and oily ingredients. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that by incorporating a polyglycerol fatty acid ester with one mole of added fatty acid and by maintaining the hydrophilic-lipophilic balance (HLB) of the surfactant in the formulation at a predetermined value or higher, it is possible to produce a bath additive that is excellent in cloudiness and storage stability, even when it contains a large amount of glycerol / polyglycerol and oily ingredients, and that also has excellent dispersibility when added to bath water and bath water stability.Based on this finding, the present inventors have completed the following inventions.

[0008] (1) The cloudy bath additive of the present invention comprises the following components (A) to (C): (A) a polyglycerol fatty acid ester having 1 mole of fatty acid added; (B) glycerin and / or polyglycerin, (C) Oily raw materials, A cloudy bath additive containing The average HLB of the surfactant in the cloudy bath agent is greater than 4.7, The content of component (B) in the cloudy bath agent is 8% by mass or more, The content of component (C) in the cloudy bath additive is more than 30% by mass.

[0009] (2) The cloudy bath additive of the present invention may have a viscosity of 3000 mPa·s or less at 20 to 25±1°C, measured using a single cylindrical rotational viscometer with an M3 rotor at a rotation speed of 30 rpm for a measurement time of 1 minute. [Effects of the Invention]

[0010] According to the present invention, a bath additive with high opacity can be obtained even when a large amount of glycerin and / or polyglycerin is blended in. As a result, a bath additive can be obtained that can provide a high level of relaxation, healing, or an elegant or luxurious feeling during use (bathing), and a high level of moisturizing effect after bathing.

[0011] According to the present invention, a bath additive having high storage stability can be obtained even when a large amount of oily ingredients is blended.

[0012] By blending a large amount of glycerin / polyglycerin into the bath additive of the present invention, it is possible to obtain a cloudy bath additive that provides high moisturizing properties after bathing.

[0013] By blending a large amount of oily ingredients into the bath additive of the present invention, it is possible to obtain a cloudy bath additive that has a high degree of cloudiness and can be expected to have moisturizing effects, skin protecting effects, and emollient effects after bathing.

[0014] According to the present invention, a bath additive with excellent dispersibility can be obtained that can be easily added to bath water, disperses quickly in the water, and makes the water cloudy.

[0015] According to the present invention, bath additives can be added to cloudy water, but the components do not separate even after a certain period of time has passed, resulting in a bath additive with excellent bathwater stability. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a table showing the formulations and evaluation results of cloudy bath additives produced using various nonionic surfactants. [Figure 2] 1 is a table showing the formulations and evaluation results of cloudy bath additives produced by varying the average HLB of surfactants between 4.7 and 15.7. [Figure 3] 1 is a table showing the formulations and evaluation results of cloudy bath additives produced using glycerin and polyglycerin. [Figure 4] 1 is a table showing the formulations and evaluation results of cloudy bath additives produced by varying the amount of glycerin blended between 4 and 22.5% by mass. [Figure 5] 1 is a table showing the formulations and evaluation results of cloudy bath additives produced using various oily ingredients. [Figure 6] 1 is a table showing the formulations and evaluation results of cloudy bath additives manufactured with mineral oil content of 30% by mass or 45% by mass. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below.

[0018] In the present invention, a bath additive refers to a preparation whose main purpose is to be added to bathwater. A cloudy bath additive refers to a bath additive that has the property of making the water it is added to cloudy (cloudiness). The color of the cloudy bath additive is not particularly limited, and can be appropriately selected, such as red, yellow, green, blue, purple, or white, depending on the product concept and the desired effect of the product.

[0019] The form of the cloudy bath additive can be, for example, a liquid form (including liquid and sol form), and may be an oil-in-water (O / W) type or water-in-oil (W / O) type emulsion.

[0020] In the present invention, the term "cloudiness" refers to the degree of cloudiness in bathwater containing bath additives. Cloudiness can be confirmed visually or, for example, by absorbance, as shown in the examples described below. In Japanese Patent No. 6226843, a cosmetic product is considered to be cloudy if its absorbance at a wavelength of 660 nm is 0.05 or higher. Based on the general understanding of those skilled in the art, in the present invention, bathwater containing bath additives can be evaluated as "having cloudiness" if its absorbance at a wavelength of 660 nm is 0.05 or higher.

[0021] In the present invention, "storage stability" refers to the degree of change in state (mainly separation of the oil and aqueous phases in the case of an emulsion) when a cloudy bath additive is stored for a certain period of time. That is, "storage stable," "high storage stability," or "good storage stability" refers to little or no change in the state of the formulation after a certain period of time has passed, or to a long period of time until a change in state occurs. Conversely, "no storage stability," "low storage stability," or "poor storage stability" refers to a large change in the state of the formulation after a certain period of time has passed, or to a short storage period until a change in state occurs. Storage stability can be evaluated, for example, by placing a cloudy bath additive in a sealed container, storing it at a relatively high temperature of about room temperature to 50°C for a certain period of time, and then visually or microscopically observing the state.

[0022] In the present invention, "bath water stability" refers to the degree of change in the state of the water (mainly separation of contained components, such as the formation of an oil film on the surface of the water) when water is clouded by adding a cloudy bath additive and held for a certain period of time. Specifically, "bath water stability," "high bath water stability," or "good bath water stability" refers to little or no change in the state of the water after a certain period of time has passed, or a long time until a change in state occurs. Conversely, "no bath water stability," "low bath water stability," or "poor bath water stability" refers to a large change in the state of the water after a certain period of time has passed, or a short time until a change in state occurs. Bath water stability can be evaluated, for example, by adding a cloudy bath additive to cloudy water (water at a temperature typically used for bathing, e.g., 38-45°C), holding the water at room temperature (normal temperature), and then observing the state of the water visually or with a microscope.

[0023] In the present invention, "dispersibility" refers to the manner in which a cloudy bath additive, once added, spreads throughout the water. Specifically, "excellent dispersibility," "good dispersibility," or "high dispersibility" means that the added bath additive spreads quickly or easily throughout the water. Conversely, "poor dispersibility," "low dispersibility," or "no dispersibility" means that the added bath additive takes a considerable amount of time to spread throughout the water, or that spreading is difficult (such as requiring vigorous stirring). Dispersibility can be evaluated, for example, by visually or microscopically observing the diffusion of the bath additive into water (at a temperature range typically used for bathing, e.g., 38-45°C) immediately after adding the cloudy bath additive, or by measuring the time it takes for the bath additive to spread throughout the water.

[0024] The cloudy bath additive contains (A) a polyglycerin fatty acid ester having one mole of added fatty acid, (B) glycerin and / or polyglycerin, and (C) an oily ingredient.

[0025] A polyglycerol fatty acid ester having one mole of added fatty acid (A) refers to a nonionic surfactant in which one mole of fatty acid is ester-bonded to one mole of polyglycerol. The degree of polymerization of glycerol in the polyglycerol moiety is not particularly limited, and examples include 2 to 10, and any of these can be used. The type of fatty acid in the fatty acid moiety is also not particularly limited, and examples include saturated and unsaturated fatty acids of C6, C8, C10, or C12 to C28, and one or more of these may be used. Component (A) can be one that can be used in cosmetics, quasi-drugs, pharmaceuticals, foods, etc., and specific examples include polyglyceryl stearate, polyglyceryl isostearate, polyglyceryl myristate, polyglyceryl oleate, polyglyceryl laurate, and polyglyceryl caprylate. Component (A) may be used alone or in combination of two or more.

[0026] In the bath additive of the present invention, the surfactant may be component (A) alone, or component (A) may be used in combination with a surfactant that does not belong to component (A).

[0027] The "average HLB" of a surfactant refers to the HLB value of the surfactant when a bath additive contains one type of surfactant. On the other hand, when a bath additive contains two or more types of surfactants, it refers to the value calculated by multiplying each HLB value by the blending ratio. For example, when two types of surfactants a and b with HLB values ​​of [HLBa] and [HLBb] are used, the average HLB value can be calculated using the following formula 1. When three or more types of surfactants are used, the average HLB can be calculated in the same way. [Formula 1] TIFF2026018345000002.tif26165

[0028] In the bath additive of the present invention, the average HLB of the surfactant can be appropriately set depending on the type and amount of oily raw material, the type and amount of other ingredients, the formulation, etc. For example, from the viewpoint of storage stability and dispersibility, the average HLB can be greater than 4.7, 4.8 or more, 4.9 or more, 5.0 or more, 5.2 or more, 5.4 or more, 5.6 or more, 5.8 or more, 6.0 or more, 6.2 or more, 6.4 or more, 6.6 or more, 6.8 or more, 7.0 or more, 7.2 or more, 7.4 or more, 7.6 or more, 7.8 or more, 8.0 or more, or 8.2 or more. The average HLB may be adjusted to the above value using component (A) alone, or may be adjusted to the above value using component (A) in combination with a surfactant not belonging to component (A).

[0029] The amount of surfactant in a bath additive can be appropriately set depending on the type and amount of other ingredients, dosage form, etc. For example, from the viewpoints of storage stability and dispersibility, the lower limit of the amount of surfactant can be 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, or 5% by mass or more, based on the total amount of bath additive taken as 100. Furthermore, the upper limit of the amount of surfactant can be 20% by mass or less, 19% by mass or less, 18% by mass or less, 17% by mass or less, 16% by mass or less, 15% by mass or less, 14% by mass or less, 13% by mass or less, 12% by mass or less, 11% by mass or less, or 10% by mass or less, based on the viewpoints of avoiding stickiness and other issues resulting from the surfactant, which can lead to poor feel and sensation when used, reducing skin irritation, reducing safety concerns due to the surfactant, and suppressing foaming of bathwater, based on the total amount of bath additive taken as 100.

[0030] Alternatively, from the viewpoint of storage stability, the lower limit of the amount of surfactant blended can be set to a mass ratio of more than 0.016, 0.017 or more, 0.018 or more, 0.019 or more, or 0.02 or more relative to 1 unit of the oil-based raw material. The upper limit can be set to a mass ratio of surfactant to 1 unit of the oil-based raw material of 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, or 0.4 or less relative to 1 unit of the oil-based raw material, from the viewpoint of avoiding stickiness or the like caused by the surfactant that could result in a poor feel to the touch or in use, reducing skin irritation, and reducing safety concerns caused by the surfactant.

[0031] (B) Glycerin and / or polyglycerin are components with high hygroscopicity and water retention, and are primarily incorporated into bath additives to provide moisturizing effects to the skin after bathing. Component (B) can be used in cosmetics, quasi-drugs, pharmaceuticals, foods, etc. Polyglycerin exists in various polymerization degrees, such as dimers, trimers, tetramers, hexamers, and decamers, and any of these may be used. Component (B) may be incorporated into the bath additives either alone or in combination of two or more types.

[0032] The amount of component (B) in the bath additive can be set appropriately depending on the type and amount of other ingredients, dosage form, etc. For example, from the standpoint of bath water stability, the lower limit of the amount of component (B) can be more than 8% by mass, 8.5% by mass or more, 9% by mass or more, 9.5% by mass or more, or 10% by mass or more, assuming the entire bath additive is 100. The upper limit can be 50% by mass or less, 49% by mass or less, 48% by mass or less, 47% by mass or less, 46% by mass or less, 45% by mass or less, 44% by mass or less, 43% by mass or less, 42% by mass or less, 41% by mass or less, 40% by mass or less, etc.

[0033] (C) Oil-based ingredients refer to oils or oil-soluble ingredients that have the property of preventing moisture evaporation from the skin by forming a hydrophobic film on the skin. For this reason, they are primarily incorporated into bath additives to provide post-bath moisturizing, skin-protecting, and emollient effects (reducing moisture evaporation from the skin, thereby imparting softness and smoothness to the skin). (C) ingredients can be used in cosmetics, quasi-drugs, pharmaceuticals, and foods. For example, oil-based ingredients can be classified based on their chemical structure as fats and oils, higher fatty acids, waxes, hydrocarbons, esters, higher alcohols, and silicone oils, and any of these can be used. Oil-based ingredients that are liquid, solid, or semi-solid (e.g., paste) at room temperature (e.g., 25°C) can also be used. One type of oil-based ingredient can be incorporated into a bath additive, or two or more types can be combined.

[0034] For example, examples of fats and oils include horse oil, coconut oil, shea butter, rice germ oil, olive fruit oil, camellia oil, grape seed oil, macadamia nut oil, castor oil, and apricot oil. Examples of higher fatty acids include coconut oil fatty acid, behenic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and isostearic acid. Examples of waxes include jojoba seed oil, carnauba wax, candelilla wax, beeswax, and lanolin. Examples of hydrocarbons include olefin hydrocarbons such as hydrogenated polyisobutene, isododecane, and tetradecene. Examples of the esters include triethylhexanoin, stearyl isostearate, cetyl palmitate, ethylhexyl palmitate, isopropyl myristate, 2-octyldodecyl myristate, cetyl 2-ethylhexanoate, diisostearyl malate, and examples of the higher alcohols include cetyl alcohol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, and the like.

[0035] The amount of oil-based ingredients in a bath additive can be appropriately set depending on the type and amount of other ingredients, formulation, etc. For example, from the standpoint of bath water stability, the lower limit of the amount of oil-based ingredients can be set to more than 30% by mass, 31% by mass or more, 32% by mass or more, 33% by mass or more, 34% by mass or more, 35% by mass or more, 36% by mass or more, 37% by mass or more, 38% by mass or more, 39% by mass or more, 40% by mass or more, 41% by mass or more, 42% by mass or more, 43% by mass or more, 44% by mass or more, 45% by mass or more, etc., based on the total amount of bath additive taken as 100. The upper limit can be set to 80% by mass or less, 79% by mass or less, 78% by mass or less, 77% by mass or less, 76% by mass or less, 75% by mass or less, 74% by mass or less, 73% by mass or less, 72% by mass or less, 71% by mass or less, 70% by mass or less, etc.

[0036] The viscosity of cloudy bath additives can be adjusted appropriately depending on the formulation, etc., and can be adjusted by the type of surfactant and / or average HLB value. For example, in the case of liquid bath additives, a lower viscosity is preferable from the standpoint of ease of addition to bath water and dispersibility. The viscosity measured under the following conditions can be 3000 mPa·s or less, 2900 mPa·s or less, 2800 mPa·s or less, 2700 mPa·s or less, 2600 mPa·s or less, 2500 mPa·s or less, 2400 mPa·s or less, 2300 mPa·s or less, 2200 mPa·s or less, 2100 mPa·s or less, or 2000 mPa·s or less. Viscosity can be measured according to "2.53 Viscosity Measurement Method, Method 2, Rotational Viscometer Method, of the Japanese Pharmacopoeia, 17th Edition (Ministry of Health, Labour and Welfare Notification No. 64, March 7, 2016)." Viscosity measurement conditions: Apparatus: Commercially available single-cylindrical rotational viscometer (Brookfield type viscometer), Temperature: Room temperature (20-25±1°C), Measurement time: 1 minute, Rotor: M3, Rotation speed: 30 rpm

[0037] The bath additive of the present invention can be produced by mixing and emulsifying the above components (A) to (C) according to a conventional method. Examples of emulsification methods include mechanical (physical) emulsification and physicochemical emulsification methods (phase inversion emulsification, D-phase emulsification, phase inversion temperature emulsification, liquid crystal emulsification, gel emulsification, etc.) (Teruo Horiuchi, Fundamental Theory of Emulsification, Special Review: Fundamentals and Evolution of Emulsification Technology (1), Journal of the Society of Cosmetic Chemists of Japan, Vol. 44, No. 1, pp. 2-22, 2010, DOI https: / / doi.org / 10.5107 / sccj.44.2).

[0038] Mechanical emulsification is a method of emulsification that utilizes the flow pattern in a stirring tank caused by a stirring device, the shape of the emulsification device, or changes in electrical characteristics, and examples include SPG emulsification, electrocapillary emulsification, etc. Mechanical emulsification can be carried out using, for example, a rotary stirrer or a high-pressure homogenizer.

[0039] The transfer emulsification method involves dissolving an emulsifier in an oil phase, slowly adding an aqueous phase to the mixture while stirring, and inverting the continuous phase from the oil phase to the aqueous phase to produce an O / W emulsion. In other words, the phase inversion emulsification method involves dissolving component (A) in component (C), adding the aqueous phase (water containing water-soluble components such as component (B)) to the mixture while stirring, thereby producing the bath additive of the present invention.

[0040] The D-phase emulsification method involves preparing an isotropic surfactant solution by mixing and dissolving a nonionic surfactant, water, and a polyhydric alcohol, adding and dispersing an oil phase to this while stirring to form a transparent O / D type gel emulsion, and then diluting this with an aqueous phase to produce an O / W type emulsion. In other words, with the D-phase emulsification method, the bath additive of the present invention can be produced by mixing and dissolving component (A), a portion of the aqueous phase, and component (B), adding and dispersing component (C) while stirring, and then adding and mixing the remaining aqueous phase to the resulting gel emulsion.

[0041] The phase inversion temperature emulsification method is a method in which a fine emulsion is obtained by emulsifying near the temperature at which the phase inversion from O / W emulsion to W / O emulsion occurs (phase inversion temperature, PIT), and then a stable O / W emulsion is produced by rapidly cooling (generally to a temperature 20-30°C lower). That is, with the phase inversion temperature emulsification method, the bath additive of the present invention can be produced by mixing and emulsifying components (A), (B), and (C) and water near the PIT, followed by rapid cooling.

[0042] The gel emulsification method involves mixing a surfactant with an aqueous solution of amino acids or amino acid salts to obtain a gel, adding and dispersing this gel in an oil phase, and then adding an aqueous phase with stirring to emulsify, thereby obtaining a W / O emulsion. In other words, with the gel emulsification method, component (A) is mixed with an aqueous solution of amino acids or amino acid salts to obtain a gel, adding and dispersing this gel in component (C), and then adding an aqueous phase (water containing water-soluble components such as component (B)) with stirring to emulsify, thereby producing a W / O emulsion bath additive.

[0043] The liquid crystal emulsification method is a method of dispersing and retaining a dispersed phase in a liquid crystal of a surfactant to generate fine emulsion particles. In the first step, an oil phase is added to the liquid crystal while stirring to generate a gel-like oil-in-liquid crystal emulsion in which the oil is retained in the liquid crystal. In the second step, an aqueous phase is added to the gel to generate an O / W emulsion. That is, in the liquid crystal emulsification method, liquid crystal is prepared with component (A), component (C) is added with stirring to obtain a gel, and then the aqueous phase is added to this gel to produce the bath additive of the present invention. Component (B) may be present in the liquid crystal or may be contained in the aqueous phase.

[0044] The bath additive of the present invention may contain ingredients other than the above (A) to (C) as long as the effects of the present invention are not impaired. Examples of such other ingredients include solvents or dispersion media, polyhydric alcohols such as ethanol, 1,3-butylene glycol, propylene glycol, dipropylene glycol, and pentylene glycol, disaccharides such as lactose, maltose, and trehalose, trisaccharides such as raffinose and kestose, sugar alcohols such as xylitol, erythritol, mannitol, maltitol, and sorbitol, amino acids such as betaine, PCA-Na, serine, glycine, glutamic acid, alanine, lysine, arginine, threonine, and proline, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, pH adjusters, colorants, animal and plant extracts, vitamins and their derivatives, whitening agents, anti-inflammatory agents, chelating agents, inorganic or organic salts, solubilizers, preservatives, disinfectants, moisturizers, antioxidants, thickeners, fragrances, cationic polymers, refreshing agents, and cooling agents. These other ingredients can be added as needed during or after the preparation of the bath additives.

[0045] The bath additive of the present invention can be used, for example, by adding it to the water in a bathtub. The temperature of the water can be appropriately set according to the user's preference. The amount of bath additive added can also be appropriately set depending on the user's preference, the dosage form, and the blending concentration of various ingredients. In the case of a liquid bath additive, for example, 10 to 50 mL can be added for 200 L of water (a typical household-sized bathtub).

[0046] The present invention will be described below based on examples, but the technical scope of the present invention is not limited to the features shown in these examples. [Example]

[0047] <Test Method> Unless otherwise specified, the tests were carried out according to the following methods. (1) Raw materials used A cloudy bath additive was produced using the raw materials shown in Table 1 (all commercially available products). [Table 1]

[0048] (2) Manufacturing of cloudy bath salts Components (A), (B), and (C), other raw materials, and water (purified water) were mixed using the D-phase emulsification method to produce cloudy bath additives in the form of O / W emulsions. The formulation of the bath additives is shown in each example.

[0049] (3) Evaluation (3-1) Viscosity The viscosity of the bath additives was measured immediately after production. The viscosity measurement conditions were as follows: measuring device: VISCOMETER TVB-10M (Toki Sangyo), room temperature (approximately 25°C), measurement time: 1 minute, rotor: M3, rotation speed: 30 rpm.

[0050] (3-2) Storage stability The bath additives immediately after production were placed in a transparent, airtight container (50 mL capacity) and left in a thermostatic bath at 50° C. for one week. Thereafter, the appearance was visually observed and evaluated according to the following criteria. ○: Remains as one layer (no or very little change in state). ×: Separated into two layers. -: Not rated.

[0051] (3-3) Dispersibility when adding bath water The bath additives in this example are assumed to be added at a rate of 30 mL to a typical household-sized bathtub filled with tap water (200 L). Based on this assumption, 200 mL of hot water (45°C) was placed in a transparent container to serve as a bathwater sample, and 30 μL of the prepared bath additive was added. After light stirring, the dispersion of the bath additives and the cloudiness of the water were visually observed and evaluated according to the following criteria. ○: The bath additives disperse quickly and the entire bath quickly becomes cloudy. ×: It takes a considerable amount of time for the bath additive to disperse and for the entire bath water to become cloudy, or the bath additive does not disperse. -: Not rated.

[0052] (3-4) Turbidity of bath water 30 μL of the prepared bath additive was added to 200 mL of hot water (45°C) and gently stirred to prepare a bath water sample. A portion of the bath water sample was then taken and its absorbance at a wavelength of 660 nm was measured using a ratio beam spectrophotometer U-5100 (Hitachi High-Tech Science Corporation). The higher the absorbance value, the greater the degree of turbidity as confirmed by visual observation. Furthermore, an absorbance value of 0.05 or greater is considered a cloudy cosmetic product (Patent No. 6226843). Based on these findings, the measured absorbance was designated the "turbidity of the bath water sample," and a value of 0.05 or greater was evaluated as "cloudy."

[0053] (3-5) Bath water stability 30 μL of the prepared bath additive was added to 200 mL of hot water (45°C) and gently stirred to prepare a bath water sample. This was left to stand at room temperature for 12 hours and then photographed. The container was also tilted forward by approximately 15 degrees, and the presence or absence of oil film formation was visually observed and evaluated according to the following criteria. ○: No oil film is formed. △: A slight oil film is formed. ×: An oil film is formed. -: Not rated.

[0054] <Example 1> Examination of surfactant types Cloudy bath additives (Samples 1-4) were manufactured using various nonionic surfactants and evaluated. The nonionic surfactants used were polyglyceryl-4 isostearate and polyglyceryl-10 myristate as polyglycerol fatty acid esters with one mole of added fatty acid, polyglyceryl-10 trilaurate as polyglycerol fatty acid esters with three moles of added fatty acid, and PEG-40 hydrogenated castor oil as an ether-ester mixture with polyethylene glycol (PEG) as the hydrophilic group. The formulations and evaluation results for Samples 1-4 are shown in Figure 1.

[0055] As shown in Figure 1, Sample 2 (polyglyceryl-10 trilaurate) and Sample 3 (PEG-40 hydrogenated castor oil) could not be emulsified to produce bath additives. In contrast, Sample 1 (polyglyceryl-4 isostearate) and Sample 4 (polyglyceryl-10 myristate) produced bath additives with viscosities of 1208 mPa·s and 398 mPa·s, respectively, and these were stable (○) for more than one week at 50°C. Furthermore, Samples 1 and 4 dispersed quickly upon addition to the bath water, quickly turning the entire bath water cloudy (○), and the cloudiness index was 0.364 and 0.220, respectively, providing sufficient cloudiness (above 0.05). Furthermore, the bath water remained stable (○), with no oil film forming even 12 hours after addition of the bath additives.

[0056] These results demonstrate that by using a polyglycerol fatty acid ester with one mole of added fatty acid, it is possible to produce a cloudy bath additive that has excellent storage stability, dispersibility, cloudiness, and bathwater stability, even when it contains a high concentration of both glycerol (component B) and oil-based raw material (component C).

[0057] Example 2: Examination of HLB of surfactants Polyglyceryl-2 isostearate (HLB: 4.7), polyglyceryl-4 isostearate (HLB: 8.2), and polyglyceryl-10 myristate (HLB: 14.0), which are polyglycerol fatty acid esters with one mole of added fatty acid, were used alone or in combination to vary the average HLB between 4.7 and 15.7, and cloudy bath additives, Samples 1 to 7, were manufactured and evaluated. The formulations and evaluation results for Samples 1 to 7 are shown in Figure 2.

[0058] As shown in Figure 2, sample 1 (average HLB: 4.7) produced a bath additive with a viscosity of 3197 mPa·s. However, separation was observed after two days of storage at 50°C (×). Furthermore, the additive did not disperse in the hot water (×). In contrast, samples 2 to 7 (average HLB: 8.3 to 15.7) had viscosities of 233 to 1208 mPa·s, and all were stable at 50°C for more than one week (○). Furthermore, samples 2 to 7 rapidly dispersed upon addition to bath water, quickly clouding the entire bath water (○), and the turbidity was 0.187 to 0.498, providing sufficient turbidity (0.05 or greater). Furthermore, the bath water remained stable, with no oil film forming even 12 hours after addition of the bath additive (○).

[0059] These results demonstrate that by using surfactants with an average HLB of over 4.7, it is possible to produce opaque bath additives that have excellent storage stability, dispersibility, opacity, and bathwater stability, even when containing high concentrations of both glycerin (component B) and oil-based ingredients (component C).

[0060] Example 3: Examination of types of polyol Glycerin, diglycerin, and polyglycerin-3 (glycerin trimer) were used as polyols to produce and evaluate cloudy bath additives Samples 1 to 3. The formulations and evaluation results of Samples 1 to 3 are shown in FIG.

[0061] As shown in Figure 3, bath additives with viscosities of 398 mPa·s, 421 mPa·s, and 437 mPa·s were produced from Sample 1 (glycerin only), Sample 2 (glycerin and diglycerin combined), and Sample 3 (glycerin and polyglycerin-3 combined), respectively, and were stable for more than one week at 50°C (○). Furthermore, all of these additives dispersed quickly upon addition to bath water, quickly turning the entire bath water cloudy (○), with sufficient cloudiness (0.220, 0.170, and 0.150, respectively (above 0.05). Furthermore, the bath water containing each additive showed no oil film formation even after 12 hours (○), indicating its stability.

[0062] These results demonstrate that in bath additives containing a polyglycerol fatty acid ester with one mole of added fatty acid and a high concentration of an oily raw material (component C), it is possible to produce a cloudy bath additive with excellent storage stability, dispersibility, cloudiness, and bathwater stability, regardless of whether the polyol is glycerol or polyglycerol.

[0063] Example 4: Examination of the amount of polyol blended The amount of glycerin blended was varied between 4 and 22.5% by mass, and cloudy bath additives, Samples 1 to 3, were manufactured and evaluated. The formulations and evaluation results of Samples 1 to 3 are shown in FIG.

[0064] As shown in Figure 4, a bath additive with a viscosity of 54 mPa·s was produced using Sample 1 (4% glycerin by mass), but separation occurred after three days of storage at 50°C (×). Furthermore, an oil film formed in the bath water 12 hours after the bath additive was added (×). In contrast, Sample 2 (8% glycerin by mass) and Sample 3 (22.5% glycerin by mass) had viscosities of 66 mPa·s and 398 mPa·s, respectively, and both were stable for more than one week at 50°C (○). Furthermore, a slight oil film formed in the bath water containing Sample 2 after 12 hours (△), but no oil film formed in the bath water containing Sample 3 (○), indicating stability.

[0065] These results demonstrate that in order for the cloudy bath additive to have storage stability and bath water stability, the blending amount of glycerin and / or polyglycerin is preferably 8 mass % or more.

[0066] <Example 5> Examination of types of oil-based raw materials Mineral oil, squalane, and triethylhexanoin were used as oil-based ingredients to produce and evaluate cloudy bath additives Samples 1 to 3. The formulations and evaluation results for Samples 1 to 3 are shown in Figure 5.

[0067] As shown in Figure 5, bath additives with viscosities of 398 mPa·s, 187 mPa·s, and 205 mPa·s were produced using Sample 1 (mineral oil), Sample 2 (squalane), and Sample 3 (triethylhexanoin), respectively, and were stable for more than one week at 50°C (○). Furthermore, all of these additives dispersed quickly upon addition to bath water, quickly turning the entire bath water cloudy (○), with sufficient cloudiness (0.05 or greater) at 0.220, 0.256, and 0.182, respectively. Furthermore, the bath water containing each additive showed no oil film formation even after 12 hours (○), demonstrating its stability.

[0068] These results demonstrate that in bath additives containing a polyglycerol fatty acid ester with one mole of added fatty acid and a high concentration of glycerol / polyglycerol (component B), regardless of the type of oily ingredient, a cloudy bath additive with excellent storage stability, dispersibility, cloudiness, and bathwater stability can be produced.

[0069] Example 6: Examination of the blending amount of oil-based raw materials Cloudy bath additives were manufactured and evaluated by blending mineral oil at a blending amount of 30 mass % (Sample 1) or 45 mass % (Sample 2). The formulations and evaluation results of Samples 1 and 2 are shown in FIG.

[0070] As shown in Figure 6, sample 1 produced a bath additive with a viscosity of 56 mPa s, but an oil film formed in the bath water 12 hours after the bath additive was added (×). In contrast, sample 2 had a viscosity of 398 mPa s, and the bath water to which it was added did not form an oil film (○), indicating stability.

[0071] These results demonstrate that in order for the cloudy bath additive to have bathwater stability, the blending amount of oily ingredients should preferably be more than 30% by mass.

Claims

1. The following components (A) to (C): (A) a polyglycerol fatty acid ester having 1 mole of added fatty acid; (B) glycerin and / or polyglycerin, (C) oily raw material, A cloudy bath additive containing The average HLB of the surfactant in the cloudy bath agent is greater than 4.7, The content of component (B) in the cloudy bath agent is 8% by mass or more, The cloudy bath agent, wherein the content of component (C) in the cloudy bath agent is more than 30% by mass.

2. 2. The cloudy bath additive according to claim 1, wherein the viscosity at 20 to 25±1° C. is 3,000 mPa·s or less, as measured with a single cylindrical rotational viscometer using an M3 rotor at a rotation speed of 30 rpm for a measurement time of 1 minute.

Images