Method for producing an emulsified composition

Abstract

To provide a method for producing an emulsified composition in which the viscosity of the emulsified composition is reduced during the manufacturing process. [Solution] A method for producing an emulsion composition, comprising the steps of: (I-1) heating and dissolving (A) a cationic surfactant and (B) a higher alcohol that is solid at 25°C to prepare an oil phase; (II-1) preparing an aqueous phase containing water; (III) mixing the oil phase and the aqueous phase, which are at a temperature higher than the aqueous phase or at the same temperature of 75°C or lower, to obtain an emulsion; and (IV) adding to the emulsion one or more selected from the group consisting of (D) amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols.

Description

Technical Field

[0001] The present invention relates to a method for producing an emulsion composition.

Background Art

[0002] As cosmetics such as rinses and conditioners, those in the form of an emulsion composition in which an oil phase and an aqueous phase are emulsified are known. As a method for producing this type of emulsion composition, for example, Patent Document 1 includes a step of preparing an oil phase, a step of preparing an aqueous phase, and a step of adding the oil phase to the aqueous phase at a temperature of 50°C or higher and 70°C or lower and mixing to obtain an emulsion composition, and a step of mixing an aromatic alcohol after cooling the obtained emulsion composition to 35°C or higher. The method of Patent Document 1 is characterized in that after the emulsification step, the emulsion composition is temporarily held at a temperature during the cooling process from the emulsification temperature (50 to 70°C) to room temperature, and an aromatic alcohol is added. Further, Non-Patent Document 1 discloses a method for producing an emulsion composition containing a cationic surfactant and a higher alcohol, in which the oil phase and the aqueous phase are each heated and dissolved at 80°C, and the aqueous phase is gradually added while stirring the oil phase while maintaining 80°C to effect emulsification.

[0003] Patent Document 2 discloses a method for producing an emulsion composition including a high-pressure emulsification step of emulsifying an oil phase containing an oil component and an aqueous phase containing an amphoteric surfactant and water by a high-pressure emulsification device. In the method of the emulsion composition of Patent Document 2, it is described that an emulsion composition having good emulsion stability can be obtained by performing emulsification under a pressure of 0.5 MPa or higher and 120 MPa or lower using a high-pressure homogenizer or the like.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0005] [Non-Patent Document 1] Personal Care Handbook, Volume II, pages 862-863 (Published June 7, 2016, Nikko Chemicals Co., Ltd., et al.) [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] From the perspective of reducing energy consumption in industrial processes, there is a need for manufacturing methods that consume less energy in the production of emulsified compositions. The manufacturing method described in Patent Document 2 is suitable for producing emulsified compositions with small particle sizes, but the energy consumed for high-pressure emulsification is large. The manufacturing methods described in Patent Document 1 and Non-Patent Document 1 use general stirring and mixing equipment, but these methods involve heating and preparing the aqueous and oil phases separately, and then emulsifying them at a temperature higher than room temperature, so the energy consumed for heating cannot be ignored. On the other hand, if a method is used in which the aqueous and oil phases are heated and prepared separately, and then emulsified at a relatively low temperature, the viscosity of the emulsified composition tends to become excessive during the manufacturing process. When the viscosity of the emulsified composition becomes excessive during the manufacturing process, problems such as increased stirring energy and stirring time arise. In view of these circumstances, one of the objectives of the present invention is to provide a method for manufacturing emulsified compositions in which the viscosity of the emulsified composition is reduced during the manufacturing process. [Means for solving the problem]

[0007] This disclosure includes the following inventions [1] to [7]. [1] (I-1) A step of preparing an oil phase by heating and dissolving (A) a cationic surfactant and (B) a higher alcohol that is solid at 25°C, (C) A step of preparing an aqueous phase containing water (II-1), (III) A step of mixing the oil phase and the aqueous phase, which are at a higher temperature than the aqueous phase, or mixing the oil phase and the aqueous phase at the same temperature of 75°C or lower to obtain an emulsion, (IV) Adding to the emulsion one or more selected from the group consisting of (D) amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols, A method for producing an emulsified composition containing [the specified element].

[0008] [2](B) A step (I-2) in which a higher alcohol that is solid at 25°C is heated and dissolved to prepare an oil phase, (II-2) A step of preparing an aqueous phase containing (A) a cationic surfactant and (C) water, (III) A step of mixing the oil phase and the aqueous phase, which are at a higher temperature than the aqueous phase, or mixing the oil phase and the aqueous phase at the same temperature of 75°C or lower to obtain an emulsion, (IV) Adding to the emulsion one or more selected from the group consisting of (D) amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols, A method for producing an emulsified composition containing [the specified element].

[0009] [3] In step (III) above, When mixing the oil phase, which is at a higher temperature than the aqueous phase, with the aqueous phase, the temperature of the oil phase at the time of mixing is 50°C or higher. A method for producing an emulsified composition according to [1] or [2], wherein when the oil phase and the aqueous phase are mixed at the same temperature of 75°C or less, the temperatures of the oil phase and the aqueous phase when mixing are the same, between 50°C and 75°C. [4] The method for producing an emulsified composition according to any one of [1] to [3], wherein step (IV) is performed immediately after step (III), or when the temperature of the emulsion obtained in step (III) is 75°C or lower. [5] A method for producing an emulsified composition according to any one of [1] to [4], wherein in step (III), when mixing an oil phase with a water phase that is at a higher temperature than the water phase, the temperature difference between the temperature of the oil phase and the temperature of the water phase is 5°C or more.

[0010] [6] A method for producing an emulsified composition according to any one of [1] to [5], wherein (D) is one or more selected from the group consisting of amphoteric surfactants and cationic surfactants. [7] A method for producing an emulsified composition according to any one of [1] to [6], wherein the proportion of component (D) to the emulsified composition is 0.02% by mass or more. [Effects of the Invention]

[0011] The manufacturing method according to this disclosure provides a method for manufacturing an emulsified composition in which the viscosity of the emulsified composition can be reduced during the manufacturing process, thereby suppressing energy consumption. [Modes for carrying out the invention]

[0012] A method for producing an emulsified composition according to this disclosure comprises the steps of (I) preparing an oil phase of a specific composition, (II) preparing an aqueous phase, and (III) obtaining an emulsion by mixing the aqueous phase and the oil phase at a specific temperature, in addition to (IV) adding (D) one or more selected from the group consisting of amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols to the obtained emulsion.

[0013] Conventionally, in the production of emulsified compositions containing cationic surfactants and higher alcohols, a known method involves heating and dissolving the oil phase and aqueous phase at 80°C, and then gradually adding the aqueous phase while stirring the oil phase at 80°C to emulsify (Non-Patent Literature 1). Thus, conventional methods for producing emulsified compositions require separate thermal energy for preparing the oil phase and the aqueous phase. In contrast, the production method according to this disclosure involves performing emulsification at a lower temperature for the oil phase and aqueous phase than in conventional methods, followed by the addition of specific components. These steps reduce thermal energy while lowering the viscosity of the emulsified composition during the production process. Furthermore, an emulsified composition with moderate viscosity is obtained even after production.

[0014] [Specific examples of embodiments] The manufacturing method relating to this disclosure will be described in more detail below. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or greater and B or less".

[0015] (Component A) In the manufacturing method according to this disclosure, component (A) is a cationic surfactant. The cationic surfactant is not particularly limited as long as the effects according to this disclosure are obtained, but cationic surfactants incorporated into hair cosmetics are preferably used. The cationic surfactant may be a cationic surfactant having a hydrocarbon group with 8 to 24 carbon atoms, and examples include fatty acid ester amine salts, fatty acid amidoamine salts, urea condensed amine salt type tertiary amine salts (Arcover type tertiary amine salts), long-chain alkyltrimethylammonium salts (e.g., stearyltrimethylammonium chloride), di-long-chain alkyldimethylammonium salts, tri-long-chain alkylmonomethylammonium salts, benzalkonium type quaternary ammonium salts, monoalkyl ether type quaternary ammonium salts, etc. (Note that the above "long-chain alkyl" may be an alkyl group having 12 to 22 carbon atoms). One cationic surfactant may be incorporated, or two or more cationic surfactants may be incorporated.

[0016] When a long-chain alkyltrimethylammonium salt is blended as the component (A), examples of the ammonium salt include lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, stearyltrimethylammonium chloride, stearyltrimethylammonium bromide, behenyltrimethylammonium chloride, and behenyltrimethylammonium methosulfate. The long-chain alkyltrimethylammonium salt may be blended singly or in combination of two or more.

[0017] When a dialkyldimethyammonium salt is blended as the component (A), examples of the ammonium salt include dicetyldimethylammonium chloride, distearyldimethylammonium chloride, and dialkyl (C12-18) dimethylammonium chloride. The dialkyldimethyammonium salt may be blended singly or in combination of two or more.

[0018] When a fatty acid amidoamine is blended as the component (A), examples of the fatty acid amidoamine include palmitic acid dimethylaminopropylamide, stearic acid dimethylaminopropylamide (cosmetic display name: stearamidopropyl dimethylamine), and behenic acid dimethylaminopropylamide (cosmetic display name: behenamidopropyl dimethylamine). The fatty acid amidoamine may be blended singly or in combination of two or more.

[0019] The blending amount of the component (A) may be, for example, 0.1% by mass or more and 10% by mass or less, preferably 0.5% by mass or more and 8% by mass or less, and more preferably 1% by mass or more and 5% by mass or less, based on the total amount of the emulsion composition. For example, when the emulsion composition is a hair conditioner, if the blending amount of the component (A) is 0.1% by mass or more, the antistatic effect on hair and the effect of improving flexibility can be more effectively exerted, and if the blending amount of the component (A) is 10% by mass or less, an emulsion composition having a viscosity suitable for use as a hair conditioner can be formed.

[0020] (Component (B)) In the manufacturing method according to this disclosure, component (B) is a higher alcohol that is solid at 25°C. Examples of such higher alcohols include aliphatic alcohols having 14 to 28 carbon atoms, and higher alcohols having a linear alkyl group with 14 to 26 carbon atoms are preferred. Specifically, examples of component (B) include myristyl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, etc., and component (B) may be a combination of one or more higher alcohols that are solid at 25°C. In this specification, "solid at 25°C" means that it does not have fluidity when left standing at 25°C.

[0021] The amount of component (B) may be, for example, 0.2% to 20% by mass of the total emulsion composition, and from the viewpoint of achieving a viscosity that is easy to use on hair, it is preferably 1% to 16% by mass, and more preferably 2% to 10% by mass. For example, when the emulsion composition is a hair conditioner, by setting the amount of component (B) within this range, it is possible to create an emulsion composition that improves the shine and smoothness of the hair, as well as a stable emulsion composition with an easy-to-use viscosity.

[0022] ((C) component) In the manufacturing method relating to this disclosure, component (C) is water. The water may be deionized water or distilled water.

[0023] The amount of component (C) is, for example, 30% to 99% by mass, 35% to 97% by mass, or 40% to 95% by mass, relative to the total amount of the emulsified composition.

[0024] ((D) component) In the manufacturing method according to this disclosure, component (D) is one or more selected from the group consisting of amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols. It is preferable that component (D) is one or more selected from the group consisting of amphoteric surfactants and cationic surfactants. Component (D) is added to the emulsion obtained after step (III).

[0025] Examples of amphoteric surfactants that constitute component (D) include betaine-based amphoteric surfactants such as aminoacetic acid betaine-type surfactants and sulfobetaine-type surfactants; amino acid-based surfactants; amine oxide-based amphoteric surfactants such as amine oxide-type surfactants and amidoamine oxide-type surfactants; and natural product-based amphoteric surfactants such as lecithin. Specifically, examples include alkyldimethylaminoacetic acid betaine, fatty acid amidopropyl dimethylaminoacetic acid betaine, alkyldihydroxyethylaminoacetic acid betaine, N-alkyl-N,N-dimethylammonium-N-propyl sulfonate, N-alkyl-N,N-dimethylammonium-N-(2-hydroxypropyl) sulfonate, N-fatty acid amidopropyl-N,N-dimethylammonium-N-(2-hydroxypropyl) sulfonate, and 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine.

[0026] (D) Examples of cosmetic labeling names for amphoteric surfactants, which are component (D), include lauramidopropyl betaine, cocamidopropyl betaine, myristamidopropyl betaine, isostearamidopropyl betaine, lauryl betaine, cocobetaine, myristyl betaine, oleyl betaine, behenyl betaine, sodium lauroamphoacetate, disodium lauroamphodiacetate, sodium cocoamphoacetate, disodium cocoamphodiacetate, sodium cocoamphopropionate, disodium cocoamphodipropionate, lauryl hydroxysultaine Examples include lauramidopropyl hydroxysultaine, cocamidopropyl hydroxysultaine, decylamine oxide, lauramine oxide, myristamine oxide, cocamine oxide, stearamine oxide, oleamine oxide, behenamine oxide, lauramidopropylamine oxide, myristamidopropylamine oxide, cocamidopropylamine oxide, decyltetradecylamine oxide, dihydroxyethyl lauramine oxide, and dihydroxyethyl cocamine oxide.

[0027] The cationic surfactant that constitutes component (D) is the same as that listed for component (A). The cationic surfactant used for component (D) may be the same as the cationic surfactant used for component (A), or it may be a different cationic surfactant.

[0028] Examples of nonionic surfactants that constitute component (D) include polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene glycerin fatty acid esters, polyoxyalkylene fatty acid esters, glyceryl ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene (hydrogenated) castor oil, sucrose fatty acid esters, polyglycerin alkyl ethers, polyglycerin fatty acid esters, fatty acid alkanolamides, alkyl glycosides, etc. Among these, polyoxyalkylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyalkylene alkyl ethers are preferred.

[0029] The inorganic salt that is component (D) may be any inorganic salt used in hair cosmetics, such as sodium sulfate, aluminum sulfate, barium sulfate, calcium sulfate, magnesium sulfate, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, barium chloride, aluminum chloride, etc.

[0030] Examples of polyhydric alcohols that are component (D) include ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, glycerin, 1,3-butylene glycol, dipropylene glycol, diethylene glycol, pentylene glycol, diglycerin, polyglycerin-3, isopentyl diol, hexanediol, octanediol, tripropylene glycol, polyethylene glycol with an average degree of polymerization of ethylene oxide of 3 or more, sorbitol, etc. Polyalkylene glycol derivatives of polyhydric alcohols may be those in which alkylene oxide is added to these polyhydric alcohols and which contain a polyoxyalkylene structure. The polyoxyalkylene structure may contain one or more of polyoxyethylene, polyoxypropylene, and polyoxybutylene.

[0031] Examples of lower alcohols that constitute component (D) include ethanol and isopropyl alcohol.

[0032] In the manufacturing method according to this disclosure, by adding component (D) after mixing the oil phase and the aqueous phase to obtain an emulsion, the viscosity of the emulsion composition during the manufacturing process can be reduced, and the increase in viscosity after manufacturing can also be suppressed. This effect can be fully obtained when the amount of component (D) added is 0.02% by mass or more. The amount of component (D) added may be 0.02% by mass or more and 30% by mass or less of the total emulsion composition, and from the viewpoint of reducing the viscosity of the emulsion composition during the manufacturing process while maintaining a viscosity that is easy to use on hair, it is preferably 0.1% by mass or more and 15% by mass or less.

[0033] [Optional ingredients] The emulsified composition produced by the manufacturing method described herein may contain optional components other than those listed above. Examples of optional components include sugars, silicones, oils and fats, fatty acids, polymer compounds, amino acids, pigments, fragrances, chelating agents, pH adjusters, preservatives, and antioxidants. These optional components may be added to the oil phase or the aqueous phase, or they may be added after the oil phase and aqueous phase have been mixed to form the emulsified composition.

[0034] [Viscosity of emulsified composition] The viscosity of the emulsified composition produced by the manufacturing method according to this disclosure can be appropriately set depending on the application of the emulsified composition, but it is preferable that the viscosity measured at 60 seconds at 25°C using a B-type viscometer with an appropriate rotor is 500 mPa·s or more and 200,000 mPa·s or less. The manufacturing method according to this disclosure can produce a uniform cream-like composition within such a viscosity range. When the viscosity is approximately 1,000 mPa·s or more and 100,000 mPa·s or less, it becomes a suitable and stable emulsified composition for hair cosmetics such as conditioners and rinses. Note that the viscosity of the emulsified composition may change over time, such as during manufacturing, immediately after manufacturing, and after manufacturing (e.g., 5 days after manufacturing). The viscosity range mentioned above is the viscosity after a predetermined time (e.g., 5 days) has elapsed since manufacturing and the viscosity has become substantially constant.

[0035] [Uses of emulsified compositions] The uses of the emulsified composition produced by the manufacturing method described herein are not particularly limited, but it is preferably used as a hair cosmetic such as rinse, treatment, conditioner, styling agent, first agent for oxidative hair dye containing an oxidative dye, second agent for oxidative hair dye containing an oxidizing agent such as hydrogen peroxide, and perming agent for forming wavy or straight hair (first agent containing a reducing agent, second agent containing an oxidizing agent).

[0036] <Manufacturing method> The manufacturing method relating to this disclosure is as follows: (I) A step of preparing the oil phase, (II) The process of preparing the aqueous phase, (III) A step of mixing the oil phase and the aqueous phase to obtain an emulsion, (IV) The process includes adding the aforementioned component (D) to the emulsion.

[0037] Step (III) of the manufacturing method according to this disclosure, which involves mixing an oil phase and an aqueous phase to obtain an emulsion, includes, for example, a step of mixing an oil phase and an aqueous phase at a higher temperature than the aqueous phase to obtain an emulsion, or a step of mixing an oil phase and an aqueous phase at the same temperature to obtain an emulsion. More specifically, the process of mixing an oil phase with a temperature higher than that of the aqueous phase to obtain an emulsion includes, for example, the following steps (a) or (b). (i) A step of mixing the oil phase and the aqueous phase by adding the oil phase, which is at a higher temperature than the aqueous phase, to the aqueous phase. (b) A step of mixing the oil phase and the water phase by adding the water phase to the oil phase which is at a higher temperature than the water phase. Furthermore, a more specific example of a step to obtain an emulsion by mixing the oil phase and the aqueous phase at the same temperature is the step described in (c) below. (h) A step of mixing the oil phase and the aqueous phase at the same temperature of 75°C or lower to obtain an emulsion.

[0038] The manufacturing method relating to this disclosure may be the first manufacturing method or the second manufacturing method described below.

[0039] (First manufacturing method) The first manufacturing method relating to this disclosure (hereinafter referred to as the "first manufacturing method") is: (I-1) A step in which an oil phase is prepared by heating and dissolving (A) a cationic surfactant and (B) a higher alcohol that is solid at 25°C, (C) A step of preparing an aqueous phase containing water (II-1), (III) A step of mixing the oil phase and the aqueous phase, which are at a higher temperature than the aqueous phase, or mixing the oil phase and the aqueous phase at the same temperature of 75°C or lower to obtain an emulsion, (IV) Adding to the emulsion one or more selected from the group consisting of (D) amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols, This is a method for producing an emulsified composition containing [the specified ingredient].

[0040] The oil phase in step (I-1) of the first manufacturing method may consist of component (A) and component (B), or other components may be added in addition to components (A) and (B). Examples of other components that may be added to the oil phase include oily components other than (B), polymer compounds, powders, animal and plant extracts, microbial-derived materials, etc.

[0041] In step (I-1) of the first manufacturing method, in the step of preparing the oil phase, (A) a cationic surfactant and (B) a higher alcohol that is solid at 25°C are heated and dissolved. Components (A) and (B) are as described above. The temperature at which components (A) and (B) are heated and dissolved in step (I-1) is not particularly limited as long as it is a temperature at which components (A) and (B) are dissolved and a uniform oil phase is obtained, but it may be 50°C or higher, and from the viewpoint of shortening the process time, 60°C or higher is preferred, 65°C or higher is more preferred, and 70°C or higher is even more preferred. Furthermore, the upper limit of the temperature at which components are heated and dissolved in step (I-1) is not particularly limited, but from the viewpoint of reducing thermal energy, it may be 95°C or lower, 90°C or lower is preferred, 85°C or lower is more preferred, 80°C or lower is even more preferred, and 75°C or lower is particularly preferred.

[0042] The order in which components (A) and (B) are added in step (I-1) of the first manufacturing method is not particularly restricted. Components (A) and (B) can be added to a device equipped with a heating and stirring mechanism and stirred while being heated.

[0043] In step (II-1) of the first manufacturing method, the aqueous phase may consist of component (C), or it may contain components other than component (C) in addition to component (C). Furthermore, the aqueous phase may contain component (A), or it may not contain component (A).

[0044] In step (II-1) of the first manufacturing method, in the step of preparing the aqueous phase, a predetermined amount of component (C) may be added to a device equipped with a heating and stirring mechanism, and the temperature may be adjusted to a predetermined temperature. If components other than component (C) are to be added to the aqueous phase, the components other than component (C) may be added to the stirring device together with component (C), and heating may be performed while stirring. The temperature of the aqueous phase may be room temperature (25°C, or no temperature adjustment), 75°C or lower, or 65°C or lower. If components other than component (C) are to be added to the aqueous phase, the temperature may be raised once to obtain an aqueous solution or dispersion, and then the heating may be stopped.

[0045] In step (III) of the first manufacturing method, if an emulsion is obtained by mixing the oil phase, which is at a higher temperature than the aqueous phase, with the aqueous phase, for example, step (a) or (b) above may be mentioned.

[0046] In step (III) of the first manufacturing method, when obtaining an emulsion by step (a) above, the mixing of the oil phase and the aqueous phase is performed by adding the oil phase, which is at a higher temperature than the aqueous phase, to the aqueous phase. The method of adding the oil phase is not particularly limited; it may be added all at once or in multiple stages. It is preferable to add the oil phase while stirring the aqueous phase. It is also preferable to continue stirring after adding the entire amount of oil phase to the aqueous phase. The oil phase components are mixed while diffusing into the aqueous phase, and an emulsion is formed overall.

[0047] In step (III) of the first manufacturing method, when obtaining an emulsion by step (b) above, the mixing of the oil phase and the aqueous phase is carried out by adding the aqueous phase to the oil phase, which is at a higher temperature than the aqueous phase. The method of adding the aqueous phase is not particularly limited; it may be added all at once or in multiple stages. It is preferable to add the aqueous phase while stirring the oil phase. It is also preferable to continue stirring after adding the entire amount of aqueous phase to the oil phase. The aqueous phase components are mixed while diffusing into the oil phase, and an emulsion is formed overall.

[0048] In step (III) of the first manufacturing method, when obtaining an emulsion by step (a) or (b) above, the temperature of the oil phase and the temperature of the aqueous phase can be adjusted as appropriate so that the temperature of the oil phase is higher than the temperature of the aqueous phase. In this case, the temperature difference (ΔT) between the temperature of the oil phase and the temperature of the aqueous phase is preferably in the range of 0°C < ΔT ≤ 65°C, and more preferably 5°C ≤ ΔT ≤ 55°C. More specifically, from the viewpoint of reducing thermal energy, an oil phase prepared at 60°C to 85°C may be added to an aqueous phase at 25°C to 75°C. According to one embodiment, from the viewpoint of shortening the process time and reducing thermal energy, it is preferable that the temperature of the oil phase exceeds 65°C and the temperature of the aqueous phase is 65°C or lower.

[0049] In step (III) of the first manufacturing method, when obtaining an emulsion by step (c) above, the oil phase and the aqueous phase are mixed at the same temperature of 75°C or lower to obtain the emulsion. The mixing of the oil phase and the aqueous phase may be done by adding the oil phase to an aqueous phase at the same temperature as the oil phase, or by adding the aqueous phase to an oil phase at the same temperature as the aqueous phase. The temperatures of the oil phase and aqueous phase during the mixing are 75°C or lower.

[0050] In step (III) of the first manufacturing method, when obtaining an emulsion by step (c) above, the temperatures of the oil phase and the aqueous phase when mixing the oil phase and the aqueous phase are not particularly limited, as long as they are temperatures at which the higher alcohol, which is component (B), dissolves in the oil phase and a uniform oil phase is obtained. For example, the temperatures of the oil phase and the aqueous phase may be the same, such as 50°C or higher and 75°C or lower.

[0051] Step (IV) of the first manufacturing method involves adding the aforementioned component (D) to the emulsion obtained in step (III) after step (III). Step (IV) may be performed immediately after step (III), or after a certain period of time has elapsed after step (III). When step (IV) is performed, the temperature of the emulsion obtained in step (III) may be 75°C or lower, 70°C or lower, 65°C or lower, or 55°C or lower. Immediately after step (III) means quickly (for example, within 3 minutes) after the entire amount of the oil phase has been added to the aqueous phase in step (III) and mixed to form a homogeneous emulsion. From the viewpoint of obtaining an emulsion composition with lower viscosity after manufacturing, it is preferable that step (IV) be performed immediately after step (III).

[0052] The method of adding component (D) is not particularly limited; it may be added all at once or in multiple stages. It is preferable to add component (D) while stirring the emulsion. It is preferable to add the entire amount of component (D) to the emulsion and continue stirring. Component (D) added to the emulsion diffuses into the emulsion, reducing its viscosity. The viscosity of the emulsion produced in step (IV) is not particularly limited. Furthermore, the temperature of component (D) added to the emulsion is not particularly limited (for example, it may be at room temperature).

[0053] When fragrances, preservatives, silicones, etc. are added to the emulsified composition, these optional components may be added simultaneously with step (IV) or added after step (IV).

[0054] (Second manufacturing method) The second manufacturing method relating to this disclosure (hereinafter referred to as the "second manufacturing method") is: (B) A step (I-2) to prepare an oil phase by heating and dissolving a higher alcohol that is solid at 25°C, (A) A step of preparing the aqueous phase by dissolving or dispersing a cationic surfactant and (C) water (II-2), (C) A step of preparing an aqueous phase containing water (II-1), (III) A step of mixing the oil phase and the aqueous phase, which are at a higher temperature than the aqueous phase, or mixing the oil phase and the aqueous phase at the same temperature of 75°C or lower to obtain an emulsion, (IV) Adding to the emulsion one or more selected from the group consisting of (D) amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols, This is a method for producing an emulsified composition containing [the specified ingredient].

[0055] In step (I-2) of the second manufacturing process, the oil phase may consist of component (B), or other components that can be incorporated into the oil phase may be added in addition to component (B). Furthermore, the oil phase may contain component (A), or it may not contain component (A).

[0056] In step (I-2) of the second manufacturing method, in the step of preparing the oil phase, a higher alcohol which is solid at 25°C (B) is heated and dissolved. Component (B) is as described above. The temperature in step (I-2) is not particularly limited as long as it is a temperature at which the higher alcohol, which is component (B), dissolves and a uniform oil phase is obtained, but it may be 50°C or higher, and from the viewpoint of shortening the process time, 60°C or higher is preferred, 65°C or higher is more preferred, and 70°C or higher is even more preferred. The upper limit of the temperature in step (I-2) is not particularly limited, but from the viewpoint of reducing thermal energy, it may be 95°C or lower, 90°C or lower is preferred, 85°C or lower is more preferred, 80°C or lower is even more preferred, and 75°C or lower is particularly preferred.

[0057] In step (I-2) of the second manufacturing process, component (B) can be added to a device equipped with a heating and stirring mechanism and stirred while being heated.

[0058] In step (II-2) of the second manufacturing process, the aqueous phase may consist of component (A) and component (C), or other water-soluble components may be added in addition to components (A) and (C).

[0059] In step (II-2) of the second manufacturing method, in the step of preparing the aqueous phase, predetermined amounts of component (A) and component (C) are added to a device equipped with a heating and stirring mechanism, and the temperature is adjusted to a predetermined temperature. The order in which components (A) and (C) are added is not particularly restricted. If components other than components (A) and (C) are to be added to the aqueous phase, these components may be added together with components (A) and (C) to the stirring device, and heating may be carried out while stirring. The temperature of the aqueous phase may be room temperature (25°C, or no temperature adjustment), 75°C or lower, or 65°C or lower. If components other than component (C) are to be added to the aqueous phase, the temperature may be raised once to obtain an aqueous solution or dispersion, and then the heating may be stopped.

[0060] Steps (III) and (IV) of the second manufacturing method can be carried out in accordance with steps (III) and (IV) of the first manufacturing method, respectively.

[0061] [Examples] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0062] Experiment 1: Emulsification method by adding an oil phase to an aqueous phase (Emulsification temperature: oil phase > aqueous phase, (A) component composition: oil phase)

[0063] <Examples 1a-10a, Example 3b, Example 7b, Example 3c, Comparative Examples 1-4, Reference Example 1> The emulsified compositions of Examples 1a to 10a, Example 3b, Example 7b, Example 3c, Comparative Examples 1 to 4, and Reference Example 1 were prepared and evaluated as follows.

[0064] 1. Preparation of emulsified compositions (Part 1) [Examples 1a to 10a] (1-1) Stearyltrimethylammonium chloride, cetanol, and isopropanol were placed in a 100 mL beaker in the proportions shown in [Table 1], and heated at 85°C to dissolve and obtain the oil phase. (2-1) Purified water was added to a 500 mL beaker in the proportions shown in [Table 1] to obtain the aqueous phase, and the temperature of the aqueous phase was set to 60°C. (3-1-i) The aqueous phase described in (2-1) above was stirred with a Shinto Kagaku Co., Ltd. Three One Motor BLH1200 while the oil phase described in (1-1) above was added and mixed to obtain an emulsion. The temperature of the oil phase when it was added to the aqueous phase (temperature of the oil phase at the time of emulsification) and the temperature of the aqueous phase when the oil phase was added (temperature of the aqueous phase at the time of emulsification) were as shown in [Table 1]. (4-1) The emulsion obtained in (3-1-i) above was cooled while being mixed, and when the temperature of the emulsion reached 50°C, component (D) was added and mixed in the proportions shown in [Table 1]. Subsequently, the mixture was cooled while stirring until it reached room temperature to obtain the emulsion compositions of Examples 1a to 10a. The emulsion compositions of Examples 1a to 7a were formulated so that the amount of component (D) was 0.1% by mass relative to the emulsion composition. The values ​​for each component shown in [Table 1] represent the mass percentage (mass%), and the total amount of the emulsion composition was 400g.

[0065] [Example 3b, Example 7b] The emulsified compositions of Example 3b and Example 7b were obtained by the same manufacturing method as in Examples 1a to 10a, except that step (4-1) above was changed to (4-1') below. (4-1') Within 3 minutes after the completion of the addition of the oil phase in the emulsification described in (3-1-i) above, component (D) was added to the emulsion obtained in (3-1-i) above in the proportions shown in [Table 1] and mixed to obtain the emulsified compositions of Examples 3b and 7b.

[0066] [Example 3c] The emulsion composition of Example 3c was obtained using the same manufacturing method as in Examples 1a to 10a, except that step (2-1) above was performed with the aqueous phase temperature changed to 25°C.

[0067] [Comparative Example 1] The emulsion composition of Comparative Example 1 was obtained by the same manufacturing method as in Examples 1a to 10a, except that step (4-1) above was omitted and, after step (3-1-i), the mixture was mixed while cooling to room temperature. The total amount of the emulsion composition was 400g.

[0068] [Comparative Examples 2-3] The emulsion compositions of Comparative Examples 2 and 3 were obtained by the same manufacturing method as in Examples 1a to 10a, except that step (4-1) above was changed from component (D) to the comparative component "a mixture of highly polymerized dimethicone and dimethicone (10cs)" or "shea butter" dissolved at 60°C.

[0069] [Comparative Example 4] Comparative Example 4's emulsified composition was obtained using the same manufacturing method as in Examples 1a to 10a, except that step (2-1) above was modified by changing the temperature of the aqueous phase to 25°C, step (4-1) above was omitted, and after step (3-1-i) above, the mixture was mixed while cooling to room temperature. The total amount of the emulsified composition was 400g.

[0070] [Reference example 1] The emulsion composition of Reference Example 1 was obtained by the same manufacturing method as in Examples 1a to 10a, except that step (2-1) above was changed to 85°C for the aqueous phase, step (4-1) above was omitted, and after step (3-1-i) above, the mixture was mixed while cooling to room temperature. The total amount of the emulsion composition was 400g.

[0071] 2. Evaluation (Part 1) (1) Viscosity during manufacturing (viscosity before mixing of additives) In the above manufacturing method, during step (3-1-i), the viscosity of the emulsion when touched with a micro spatula within 1 minute after the completion of the oil phase addition was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate a better result. (2) Viscosity during manufacturing (viscosity after addition of additives) For the emulsion compositions of Examples 1a to 10a, Examples 3b, 7b, Example 3c, and Comparative Examples 2 to 3, in step (4-1) or (4-1') of the above manufacturing method, the viscosity of the emulsion when touched with a micro spatula within 1 minute after the addition of component (D), "a mixture of highly polymerized dimethicone and dimethicone (10cs)," or shea butter was evaluated on a 5-point scale according to the evaluation criteria below. For the emulsion compositions of Comparative Example 1, Comparative Example 4, and Reference Example 1, the viscosity of the emulsion when touched with a micro spatula at a temperature of 50°C during step (3-1-i) of the above manufacturing method was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate better quality. (3) Viscosity immediately after manufacturing The viscosity of each emulsified composition from each example, comparative example, and reference example 1 was evaluated on a 5-point scale when touched with a finger at room temperature, according to the evaluation criteria below. A higher number indicated a better viscosity. The evaluations (1) through (3) in Evaluation (Part 1) were conducted by evaluators who routinely evaluate emulsified compositions. <Evaluation Criteria for 《1》 to 《3》> 5: Lower viscosity than the emulsified composition in Reference Example 1 4: Equivalent to the viscosity of the emulsified composition in Reference Example 1. 3: Viscosity between the emulsified composition of Reference Example 1 and the emulsified composition of Comparative Example 1 2: Equivalent to the viscosity of the emulsified composition of Comparative Example 1. 1: Higher viscosity than the emulsion composition of Comparative Example 1

[0072] (4) Viscosity of the emulsified composition 5 days after manufacturing Emulsified compositions were placed in 12cm high, 4cm diameter glass screw-top vials, each containing 80g of the composition. After standing in a constant temperature water bath set to 25°C for 1 hour, the viscosity was measured using a Type B viscometer with a No. 4 rotor at a rotation speed of 12 rpm. The measurement taken 60 seconds after the start of measurement was adopted as the viscosity value. This viscosity measurement was performed 5 days after the manufacture of the emulsified composition.

[0073] The compositions and evaluation results for Reference Example 1, Comparative Examples 1-4, and Examples 1a-10a, 3b, 3c, and 7b are summarized in [Table 1] and [Table 2].

[0074] [Table 1]

[0075] [Table 2]

[0076] As shown in Table 1, Reference Example 1 is an example in which emulsification was performed with both the oil phase and the aqueous phase at 85°C. In Reference Example 1, an emulsified composition with a viscosity of approximately 30,000 mPa·s after 5 days of production was obtained. Examples 1a to 10a, 3b, and 7b, which are examples of the manufacturing method according to this disclosure, all had viscosity after adding component (D) during manufacturing and viscosity immediately after manufacturing that was equivalent to or lower than Reference Example 1, or lower than Comparative Example 1, which was manufactured using the same method but without adding component (D). In addition, the viscosity of the emulsion composition after 5 days in Examples 1a to 10a, 3b, and 7b was equivalent to or lower than that of Reference Example 1. By referring to Examples 3a and 3b, and Examples 7a and 7b, respectively, it was confirmed that the timing of adding component (D) is not limited. In Comparative Example 1, where component (D) was not added, the viscosity of the resulting emulsion composition was high both immediately after production and 5 days after production. In Comparative Example 2, where a mixture of high polymer dimethicone and dimethicone (10cs) was added as a comparative component of component (D), the viscosity after addition and the viscosity immediately after production were higher than that of Reference Example 1, and the viscosity after 5 days exceeded 40,000 mPa·s. In Comparative Example 3, where shea butter was added as a comparative component of component (D), the viscosity after addition and the viscosity immediately after production were higher than that of Reference Example 1, and the viscosity after 5 days exceeded 36,000 mPa·s.

[0077] As shown in Table 2, the viscosity during manufacturing in Example 3c, where the aqueous phase temperature was 25°C, was lower than that of Comparative Example 4, which had a similar composition but did not contain component (D). Furthermore, the viscosity after 5 days of manufacturing was lower than that of Reference Example 1. In contrast, Comparative Example 4, which did not contain component (D), had a high viscosity during manufacturing as described above, and its viscosity after 5 days of manufacturing was also higher than that of Reference Example 1, at approximately 36,000 mPa·s.

[0078] Experiment 2: Emulsification method by adding an aqueous phase to an oil phase (Emulsification temperature: oil phase > aqueous phase, (A) component composition: oil phase)

[0079] <Example 2b, Comparative Example 5, Reference Example 2> The emulsified compositions of Example 2b, Comparative Example 5, and Reference Example 2 were prepared and evaluated as follows.

[0080] 3. Preparation of Emulsified Compositions (Part 2) [Example 2b] The emulsified composition of Example 2b was obtained by the same manufacturing method as in Example 2a, except that step (3-1-a) above was changed to step (3-1-b) below. (3-1-b) The oil phase described in (1-1) above was stirred with a Shinto Kagaku Co., Ltd. Three One Motor BLH1200 while the aqueous phase described in (2-1) above was added and mixed to obtain an emulsion. The temperature of the oil phase when it was added to the aqueous phase (temperature of the oil phase at the time of emulsification) and the temperature of the aqueous phase when the oil phase was added (temperature of the aqueous phase at the time of emulsification) were as shown in [Table 3].

[0081] [Comparative Example 5] The emulsion composition of Comparative Example 5 was obtained by the same manufacturing method as in Example 2b, except that step (4-1) above was omitted and, after step (3-1-b), the mixture was mixed while cooling to room temperature. The total amount of the emulsion composition was 400g.

[0082] [Reference example 2] The emulsion composition of Reference Example 2 was obtained by the same manufacturing method as in Example 2b, except that step (2-1) above was modified by changing the temperature of the aqueous phase to 85°C, step (4-1) above was omitted, and after step (3-1-b) above, the mixture was mixed while cooling to room temperature. The total amount of the emulsion composition was 400g.

[0083] 4. Evaluation (Part 2) (1) Viscosity during manufacturing (viscosity before mixing of additives) In the above manufacturing method, during step (3-1-b), the viscosity of the emulsion when touched with a micro spatula within 1 minute after the completion of the oil phase addition was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate a better result. (2) Viscosity during manufacturing (viscosity after addition of additives) For the emulsion composition of Example 2b, in step (4-1) of the above manufacturing method, the viscosity of the emulsion when touched with a micro spatula within 1 minute after the addition of component (D) was evaluated on a 5-point scale according to the evaluation criteria below. Furthermore, for the emulsion compositions of Comparative Example 5 and Reference Example 2, in step (3-1-b) of the above manufacturing method, the viscosity of the emulsion when touched with a micro spatula at a temperature of 50°C was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate better quality. (3) Viscosity immediately after manufacturing The viscosity of the emulsified compositions of Example 2b, Comparative Example 5, and Reference Example 2 at room temperature was evaluated on a 5-point scale according to the evaluation criteria below. A higher number indicated a better viscosity. In addition, the evaluations of items 《1》 to 《3》 in evaluation (part 2) were conducted by evaluators who routinely evaluate emulsified compositions. <Evaluation Criteria for 《1》 to 《3》> 5: Lower viscosity than the emulsified composition in Reference Example 2 4: Equivalent to the viscosity of the emulsified composition in Reference Example 2. 3: Viscosity between the emulsified composition of Reference Example 2 and the emulsified composition of Comparative Example 5 2: Equivalent to the viscosity of the emulsified composition of Comparative Example 5. 1: Higher viscosity than the emulsion composition of Comparative Example 5

[0084] Furthermore, the viscosity of the emulsified composition five days after manufacturing was evaluated using the same method as described in "2. Evaluation (Part 1)" above.

[0085] The compositions and evaluation results for Reference Example 2, Comparative Example 5, and Example 2b are shown in [Table 3].

[0086] [Table 3]

[0087] As shown in Table 3, Reference Example 2 is an example in which emulsification was performed with both the oil phase and the aqueous phase at 85°C. In Reference Example 2, an emulsified composition with a viscosity of approximately 32,000 mPa·s after 5 days of production was obtained. Example 2b, an example of the manufacturing method according to this disclosure, had a viscosity lower than that of Reference Example 2 after adding component (D) during manufacturing and immediately after manufacturing, and also lower than that of Comparative Example 5, which was manufactured using the same method but without adding component (D). Furthermore, the viscosity of the emulsified composition in Example 2b after 5 days was lower than that of Reference Example 2.

[0088] Experiment 3: Emulsification method by adding an oil phase to an aqueous phase (Emulsification temperature: oil phase = aqueous phase, (A) component composition: oil phase)

[0089] <Example 11a, Comparative Example 6, Reference Example 1> The emulsified compositions of Example 11a, Comparative Example 6, and Reference Example 1 were prepared and evaluated as follows.

[0090] 5. Preparation of Emulsified Compositions (Part 3) [Example 11a] The emulsified composition of Example 11a was obtained by the same manufacturing method as in Example 2a, except that step (3-1-i) above was changed to step (3-1-c) below. (3-1-c) The aqueous phase described in (2-1) above was stirred with a Shinto Kagaku Co., Ltd. Three One Motor BLH1200 while the oil phase described in (1-1) above was added and mixed to obtain an emulsion. The temperature of the oil phase when it was added to the aqueous phase (temperature of the oil phase at the time of emulsification) and the temperature of the aqueous phase when the oil phase was added (temperature of the aqueous phase at the time of emulsification) were as shown in [Table 4].

[0091] [Comparative Example 6] The emulsion composition of Comparative Example 6 was obtained by the same manufacturing method as in Example 11a, except that step (4-1) above was omitted and, after step (3-1-c), the mixture was mixed while cooling to room temperature. The total amount of the emulsion composition was 400 g.

[0092] [Reference example 1] 1. The emulsion composition of Reference Example 1 was obtained by the same manufacturing method as that of Reference Example 1 in the preparation of the emulsion composition (Part 1).

[0093] 6. Evaluation (Part 3) (1) Viscosity during manufacturing (viscosity before mixing of additives) In the above manufacturing method, during step (3-1-c) or (3-1-a), the viscosity of the emulsion when touched with a micro spatula within 1 minute after the completion of oil phase addition was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate better quality. (2) Viscosity during manufacturing (viscosity after addition of additives) For the emulsion composition of Example 11a, in step (4-1) of the above manufacturing method, the viscosity of the emulsion when touched with a micro spatula within 1 minute after the addition of component (D) was evaluated on a 5-point scale according to the evaluation criteria below. Furthermore, for the emulsion compositions of Comparative Example 6 and Reference Example 1, in step (3-1-c) or (3-1-a) of the above manufacturing method, the viscosity of the emulsion when touched with a micro spatula at a temperature of 50°C was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate better quality. (3) Viscosity immediately after manufacturing The viscosity of the emulsified compositions of Example 11a, Comparative Example 6, and Reference Example 1 at room temperature was evaluated on a 5-point scale according to the evaluation criteria below. A higher number indicated a better result. The evaluations (1) through (3) in Evaluation (Part 3) were conducted by evaluators who routinely evaluate emulsified compositions. <Evaluation Criteria for 《1》 to 《3》> 5: Lower viscosity than the emulsified composition in Reference Example 1 4: Equivalent to the viscosity of the emulsified composition in Reference Example 1. 3: Viscosity between the emulsified composition of Reference Example 1 and the emulsified composition of Comparative Example 6 2: Equivalent to the viscosity of the emulsified composition of Comparative Example 6. 1: Higher viscosity than the emulsion composition of Comparative Example 6

[0094] Furthermore, the viscosity of the emulsified composition five days after manufacturing was evaluated using the same method as described in "2. Evaluation (Part 1)" above.

[0095] The compositions and evaluation results for Reference Example 1, Comparative Example 6, and Example 11a are shown in [Table 4].

[0096] [Table 4]

[0097] As shown in Table 4, Reference Example 1 is an example in which emulsification was performed with both the oil phase and the aqueous phase at 85°C. In Reference Example 1, an emulsified composition with a viscosity of approximately 30,000 mPa·s was obtained 5 days after production. Example 11a, which is an example of the manufacturing method according to this disclosure, had a viscosity lower than that of Reference Example 1 after adding component (D) during manufacturing and immediately after manufacturing, and also lower than that of Comparative Example 6, which was manufactured using the same method but without adding component (D). Furthermore, the viscosity of the emulsified composition in Example 11a after 5 days was lower than that of Reference Example 1.

[0098] Experiment 4: Emulsification method by adding an oil phase to an aqueous phase (Emulsification temperature: oil phase > aqueous phase, (A) component composition: aqueous phase)

[0099] <Example 11b, Comparative Example 7, Reference Example 3> The emulsified compositions of Example 11b, Comparative Example 7, and Reference Example 3 were prepared and evaluated as follows.

[0100] 7. Preparation of Emulsified Compositions (Part 4) [Example 11b] (1-2) Cetanol was placed in a 100 mL beaker in the proportions shown in [Table 5] and heated to 85°C to dissolve and obtain the oil phase. (2-2) Stearyltrimethylammonium chloride, isopropanol, and purified water were added to a 500 mL beaker in the proportions shown in [Table 5] to obtain the aqueous phase, and the temperature of the aqueous phase was set to 65°C. (3-2-i) The aqueous phase described in (2-2) above was stirred with a Shinto Kagaku Co., Ltd. Three One Motor BLH1200 while the oil phase described in (1-2) above was added and mixed to obtain an emulsion. The temperature of the oil phase when it was added to the aqueous phase (temperature of the oil phase at the time of emulsification) and the temperature of the aqueous phase when the oil phase was added (temperature of the aqueous phase at the time of emulsification) were as shown in [Table 5]. (4-2) The emulsion obtained in (3-2-i) above was cooled while being mixed, and when the temperature of the emulsion reached 50°C, component (D) was added and mixed in the proportions shown in [Table 5]. Subsequently, the mixture was cooled while stirring until it reached room temperature to obtain the emulsion composition of Example 11b. The values ​​for each component shown in [Table 5] represent the mass percentage (mass%), and the emulsion composition was prepared with a total amount of 400g.

[0101] [Comparative Example 7] The emulsion composition of Comparative Example 7 was obtained by the same manufacturing method as in Example 11b, except that step (4-2) above was omitted and, after step (3-2-i) above, the mixture was mixed while cooling to room temperature. The total amount of the emulsion composition was 400g.

[0102] [Reference example 3] The emulsion composition of Reference Example 3 was obtained by the same manufacturing method as in Example 11b, except that step (2-2) above was modified by changing the temperature of the aqueous phase to 85°C, step (4-2) above was omitted, and after step (3-2-i) above, the mixture was mixed while cooling to room temperature. The total amount of the emulsion composition was 400g.

[0103] 8. Evaluation (Part 4) (1) Viscosity during manufacturing: 1 (before mixing of additives) In the above manufacturing method, during step (3-2-i), the viscosity of the emulsion when touched with a micro spatula within 1 minute after the completion of oil phase addition was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate better quality. (2) Viscosity during manufacturing (viscosity after addition of additives) For the emulsion composition of Example 11b, in step (4-2) of the above manufacturing method, the viscosity of the emulsion when touched with a micro spatula within 1 minute after the addition of component (D) was evaluated on a 5-point scale according to the evaluation criteria below. For the emulsion compositions of Comparative Example 7 and Reference Example 3, in step (3-2-i) of the above manufacturing method, the viscosity of the emulsion when touched with a micro spatula at a temperature of 50°C was evaluated on a 5-point scale according to the evaluation criteria below. A higher number was considered to indicate better quality. (3) Viscosity immediately after manufacturing The viscosity of the emulsified compositions of Example 11b, Comparative Example 7, and Reference Example 3 at room temperature was evaluated on a 5-point scale according to the evaluation criteria below. A higher number indicated a better viscosity. In addition, the evaluations (1) to (3) in evaluation (4) were conducted by evaluators who routinely evaluate emulsified compositions. <Evaluation Criteria for 1) to 3)> 5: Lower viscosity than the emulsified composition in Reference Example 3 4: Equivalent to the viscosity of the emulsified composition in Reference Example 3. 3: Viscosity between the emulsion composition of Reference Example 3 and the emulsion composition of Comparative Example 7 2: Equivalent to the viscosity of the emulsified composition of Comparative Example 7. 1: Higher viscosity than the emulsion composition of Comparative Example 7

[0104] Furthermore, the viscosity of the emulsified composition five days after manufacturing was evaluated using the same method as described in "2. Evaluation (Part 1)" above.

[0105] The compositions and evaluation results for Reference Example 3, Comparative Example 7, and Example 11b are shown in [Table 5].

[0106] [Table 5]

[0107] As shown in Table 5, Reference Example 3 is an example in which emulsification was performed with both the oil phase and the aqueous phase at 85°C. In Reference Example 3, an emulsified composition was obtained in which the viscosity after 5 days of production exceeded 50,000 mPa·s. Example 11b, an example of the manufacturing method according to this disclosure, showed that the viscosity after adding component (D) during manufacturing and the viscosity immediately after manufacturing were lower than that of Reference Example 3, and also lower than that of Comparative Example 7, which was manufactured using the same method but without adding component (D). Furthermore, the viscosity of the emulsified composition in Example 11b after 5 days was lower than that of Reference Example 1.

[0108] It has been confirmed that the manufacturing method described herein results in minimal viscosity increase during manufacturing, and the viscosity does not become excessive after manufacturing, thus yielding an emulsified composition with appropriate viscosity.

[0109] The embodiments disclosed herein should be understood to be illustrative in all respects and not restrictive in any way. The scope of the present invention is defined by the claims and is intended to include all modifications in the sense and scope equivalent to the claims.

Claims

1. (I-1) A step of preparing an oil phase by heating and dissolving (A) a cationic surfactant and (B) a higher alcohol that is solid at 25°C, (C) A step of preparing an aqueous phase containing water (II-1), (III) A step of mixing the oil phase and the aqueous phase, which are at a higher temperature than the aqueous phase, or mixing the oil phase and the aqueous phase at the same temperature of 75°C or lower to obtain an emulsion, (IV) Adding (D) one or more surfactants selected from the group consisting of amphoteric surfactants and cationic surfactants to the emulsion, A method for producing an emulsified composition containing [the specified element].

2. (B) A step (I-2) to prepare an oil phase by heating and dissolving a higher alcohol that is solid at 25°C, (A) A step of preparing an aqueous phase containing a cationic surfactant and (C) water (II-2), (III) A step of mixing the oil phase and the aqueous phase, which are at a higher temperature than the aqueous phase, or mixing the oil phase and the aqueous phase at the same temperature of 75°C or lower to obtain an emulsion, (IV) Adding to the emulsion one or more selected from the group consisting of (D) amphoteric surfactants, cationic surfactants, nonionic surfactants, inorganic salts, polyhydric alcohols, polyalkylene glycol derivatives of polyhydric alcohols, and lower alcohols, A method for producing an emulsified composition containing [the specified element].

3. In the above step (III), When mixing the oil phase, which is at a higher temperature than the aqueous phase, with the aqueous phase, the temperature of the oil phase at the time of mixing is 50°C or higher. When the oil phase and the aqueous phase are mixed at the same temperature of 75°C or lower, the temperatures of the oil phase and the aqueous phase during mixing are the same, between 50°C and 75°C. A method for producing the emulsified composition according to claim 1 or 2.

4. Step (IV) is performed immediately after step (III), or when the temperature of the emulsion obtained in step (III) is 75°C or lower. A method for producing the emulsified composition according to claim 1 or 2.

5. In step (III) above, when mixing an oil phase with a water phase that is at a higher temperature than the water phase, the temperature difference between the temperature of the oil phase and the temperature of the water phase is 5°C or more. A method for producing the emulsified composition according to claim 1 or 2.

6. The aforementioned component (D) is one or more selected from the group consisting of amphoteric surfactants and cationic surfactants. A method for producing the emulsified composition according to claim 2.

7. The proportion of component (D) to the emulsified composition is 0.02% by mass or more. A method for producing the emulsified composition according to claim 1 or 2.

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