Method for producing emulsion composition

Abstract

To provide a method for producing an emulsion composition which contains a polyion complex, has high stability, can improve a touch feel of the hair after treatment when used as a hair cosmetic composition and can inhibit hair from spreading under a high humidity condition.SOLUTION: There is provided a method for producing an emulsion composition which comprises a component (A): one or more polymers selected from the group consisting of a cationic polymer and an amphoteric polymer, a component (B): an anionic polymer, a component (C): an organic acid and a component (D): water, and the method comprises the following step (1) and either one of the step (2-1) or step (2-2), wherein the total blending amount of the component (A) and the component (B) in the emulsion composition is less than 1.0 mass% in 100 mass% of the total amount of the emulsion composition. Step (1): a step of preparing a mixture A containing the above components (A) to (D), step (2-1): a step of preparing an emulsion (I) by mixing the mixture A with an oil phase component including an emulsion-forming component, step (2-2): a step of preparing an emulsion (II) by mixing the oil phase component including the emulsion-forming component and a water phase component other than the mixture A, followed by mixing the mixture A.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Cosmetic compositions containing a cationic polymer and an anionic polymer are known. For example, Patent Document 1 describes that by using a composition for treating keratinous materials, characterized by containing at least one anionic polymer and at least one cationic polymer in a solvent medium, the anionic polymer can be fixed to keratinous materials, particularly hair, skin, or nails. It is hypothesized that the above effect is due to a complex formed by the interaction between the anionic polymer and the cationic polymer.

[0003] As a composition containing a complex formed from a cationic polymer and an anionic polymer (hereinafter also referred to as a "polyion complex"), those in the form of an oil-in-water or water-in-oil emulsion composition are known. In general, the improvement of the stability over time of an emulsion composition is an issue, and stable emulsion compositions or methods for producing stable emulsion compositions have also been studied.

[0004] For example, Patent Document 2 discloses that a hair treatment composition can be easily produced in a stable emulsified state containing a polymer supplied in powder form, by producing the hair treatment composition through a step of emulsifying oil and water with a surfactant, a step of dissolving a powdery cationic polymer and a powdery anionic polymer in water, and a step of mixing these.

[0005] Patent Document 3 discloses a stable composition containing polyion complex particles having various cosmetic functions, which comprises (a) at least one particle containing at least one cationic polymer and at least one amphoteric polymer, at least one anionic polymer and at least one amphoteric polymer, or at least one amphoteric polymer, and at least one non-polymeric acid having two or more pKa values ​​or a salt thereof, or at least one non-polymeric base having two or more pKb values ​​or a salt thereof, and (b) at least one physiologically acceptable volatile medium. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 53-139734 [Patent Document 2] Japanese Patent Application Publication No. 11-116445 [Patent Document 3] Japanese Patent Application Publication No. 2019-1728 Summary of the Invention [Problem to be solved by the invention]

[0007] Highly stable emulsion compositions containing polyion complexes and methods for producing the same have been studied for some time, as disclosed in Patent Documents 1 to 3. However, there is still room for improvement in the performance of emulsion compositions containing polyion complexes when used as cosmetic compositions. For example, hair conditioners, which are a type of hair cosmetic composition, are required to have a pleasant feel when applied to hair, and to have excellent humidity resistance, such that the treated hair does not spread even under high humidity conditions. In order to improve the feel of hair during application or after treatment, it is generally known to incorporate a cationic surfactant, a higher alcohol, etc. into a hair conditioner, but emulsion compositions incorporating these ingredients into compositions containing a polyion complex have the problem of low stability. Furthermore, conventional techniques have not been particularly effective in suppressing hair frizz under high humidity conditions.

[0008] An object of the present invention is to provide a method for producing an emulsion composition that contains a polyion complex, is highly stable, and when used as a hair cosmetic composition, provides a good feel when applied to hair, and can suppress spreading of treated hair under high humidity conditions. [Means for solving the problem]

[0009] The present inventors have found that the above-mentioned problems can be solved by mixing one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers, an anionic polymer, an organic acid, and water to prepare a mixture, and then using the mixture to produce an emulsion composition through a specified process.

[0010] That is, the present invention relates to the following. Component (A): one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers; Component (B): anionic polymer, Component (C): organic acid, and Ingredient (D): Water A method for producing an emulsion composition comprising: The production method includes the following step (1) and either step (2-1) or step (2-2): A method for producing an emulsion composition, wherein the total amount of the component (A) and the component (B) in the emulsion composition is less than 1.0 mass % relative to 100 mass % of the total amount of the emulsion composition. Step (1) A step of preparing a mixture A containing the components (A) to (D) Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing an emulsion-forming component. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing an emulsion-forming component with an aqueous phase component other than the mixture A, and then mixing the mixture A. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a method for producing an emulsion composition that contains a polyion complex, is highly stable, and when used as a hair cosmetic composition, provides a good feel when applied to hair and can suppress spreading of treated hair under high humidity conditions. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Method of producing emulsion composition] The method for producing the emulsion composition of the present invention (hereinafter also simply referred to as the "production method of the present invention") is as follows: Component (A): one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers; Component (B): anionic polymer, Component (C): organic acid, and Ingredient (D): Water A method for producing an emulsion composition comprising: The production method includes the following step (1) and either step (2-1) or step (2-2): In the method for producing an emulsion composition, the total amount of the component (A) and the component (B) in the emulsion composition is less than 1.0% by mass relative to 100% by mass of the total amount of the emulsion composition. Step (1) A step of preparing a mixture A containing the components (A) to (D) Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing an emulsion-forming component. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing an emulsion-forming component with an aqueous phase component other than the mixture A, and then mixing the mixture A. The production method of the present invention has the above-mentioned features, and thus can produce an emulsion composition that contains a polyion complex, is highly stable, and when used as a hair cosmetic composition, has a good feel when applied to hair and can suppress hair frizz under high humidity conditions. Hereinafter, steps (2-1) and (2-2) may be collectively referred to as "step (2)."

[0013] <Definition> In this specification, the term "emulsion-forming component" refers to an oily component for forming an emulsion contained in the emulsion composition obtained by the production method of the present invention. In this specification, "aqueous phase components" refers to components that constitute the aqueous phase in the production process of an emulsion composition, and "oil phase components" refers to components that constitute the oil phase in the production process of an emulsion composition.

[0014] The reason why the manufacturing method of the present invention exhibits the above-mentioned effects is not clear, but is thought to be as follows. The emulsion composition produced according to the present invention contains a polyion complex formed from component (A) and component (B). The polyion complex is an aggregate formed by chemical and electrostatic interactions between component (A) and component (B). The polyion complex is poorly soluble in water, and in the emulsion composition of the present invention, it exists in a dispersed state in the aqueous phase. By applying an emulsion composition containing the polyion complex to the surface of skin, hair, or the like, a hydrophobic film can be formed. The formation of this hydrophobic film is thought to improve the feel upon application to hair, as well as improve humidity resistance and suppress frizz under high humidity conditions.

[0015] In the production method of the present invention, in step (1), components (A) to (D) are premixed to obtain a mixture A (aqueous phase component) containing a polyion complex formed from components (A) and (B). Components (A) and (B) are dispersed in water in the presence of an organic acid, component (C), to form a polyion complex that is stably dispersed in the emulsion composition. Furthermore, by setting the combined amount of components (A) and (B) to less than 1.0% by mass based on a total mass of 100% by mass of the resulting emulsion composition, the stability of the emulsion composition is improved.

[0016] Furthermore, in the present invention, after preparing mixture A containing the polyion complex in step (1), mixture A is mixed in a predetermined order with oil phase components containing emulsion-forming components and aqueous phase components other than mixture A in step (2-1) or step (2-2). This step is believed to improve the stability of the emulsion composition, since the polyion complex formed in step (1) remains well dispersed without aggregation, separation, or the like, even when other aqueous phase and oil phase components are blended to form an emulsion in step (2). Furthermore, when the emulsion composition is used as a hair cosmetic composition such as a hair conditioner, the well-emulsified and dispersed polyion complex adheres uniformly to the hair, improving the feel upon application and the effect of inhibiting hair frizz under high-humidity conditions.

[0017] As will be described later, by adjusting the amount of component (C) used in preparing mixture A in step (1) to fall within a predetermined range, the resulting polyion complex is dispersed in the form of a suspension without being solubilized in mixture A. When mixture A in a suspension state is used in step (2-1) or (2-2), the resulting emulsion composition is likely to maintain a stable polyion complex state even when other aqueous phase components and oil phase components are blended in step (2), and it is believed that the stability of the emulsion composition, the feel upon application to hair, and the effect of suppressing hair frizz under high humidity conditions are also improved.

[0018] The emulsion composition obtained by the production method of the present invention is preferably an oil-in-water emulsion composition from the viewpoints of stability and improved usability. The emulsion composition is suitably used as a cosmetic composition such as a hair cosmetic composition, a skin cosmetic composition, etc. Among these, a hair cosmetic composition is preferred, from the viewpoints of providing a good feel when applied to hair and being effective in suppressing frizziness of hair under high humidity conditions. Examples of hair cosmetic compositions include hair shampoos, hair rinses, hair conditioners, hair treatments (including leave-in types), hair styling agents, etc. Among these, hair conditioners, hair treatments, and hair styling agents are preferred from the viewpoint of the effectiveness of the effects of the present invention. Each component to be incorporated into the emulsion composition will be described below.

[0019] (Component (A): One or more polymers selected from the group consisting of cationic polymers and amphoteric polymers) Component (A) is one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers, which are capable of forming a polyion complex through interaction with component (B). The cationic polymer of component (A) preferably refers to a polymer having cationic groups and substantially free of anionic groups and amphoteric groups. The term "substantially free of anionic groups and amphoteric groups" means that the molar ratio of anionic groups and amphoteric groups to cationic groups is preferably 0.1% or less. The amphoteric polymer of component (A) is preferably a polymer having cationic and anionic groups, a 1% aqueous solution of which has a pH of less than 5.1 at 25° C., and a total positive charge on the polymer. The pH can be measured with a pH meter. In this specification, the cationic group refers to a cationic group or a group that can be ionized to become a cationic group, and specific examples thereof include a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium group. The anionic group is an anionic group or a group that can be ionized to become an anionic group, and specifically includes one or more selected from the group consisting of acidic groups such as a carboxy group, a sulfonic acid group, and a phosphate group, preferably one or more selected from a carboxy group and a sulfonic acid group, more preferably a carboxy group. At least a portion of the anionic group may be neutralized and in the form of a salt.

[0020] The cationic charge density of component (A) is preferably 0.1 meq / g or more, more preferably 0.5 meq / g or more, even more preferably 1.0 meq / g or more, and even more preferably 2.0 meq / g or more from the viewpoint of facilitating the formation of a polyion complex through interaction with component (B), and is preferably 10 meq / g or less, more preferably 8.0 meq / g or less, and even more preferably 7.0 meq / g or less from the viewpoint of the stability of the emulsion composition. The cationic charge density of component (A) is preferably 0.1 meq / g or more and 10 meq / g or less, more preferably 0.5 meq / g or more and 8.0 meq / g or less, even more preferably 1.0 meq / g or more and 7.0 meq / g or less. The cationic charge density of component (A) can be calculated from (the number of moles of cationic groups contained per 1 g of polymer)×1000 (meq / g). The emulsion composition may use two or more polymers as component (A). In this case, the cationic charge density of component (A) is determined by calculating a weighted average of the cationic charge densities and blending amounts of each polymer.

[0021] The weight-average molecular weight (Mw) of component (A) is preferably 5,000 or more, more preferably 8,000 or more, and preferably 2,000,000 or less, more preferably 1,500,000 or less, from the viewpoints of ease of forming a polyion complex, stability of the emulsion composition, improvement of feel when applied to hair when used as a hair cosmetic composition, and suppression of hair frizz under high-humidity conditions. The weight-average molecular weight (Mw) of component (A) is preferably 5,000 or more and 2,000,000 or less, more preferably 8,000 or more and 1,500,000 or less. The weight average molecular weight of component (A) can be measured by gel permeation chromatography (GPC).

[0022] Specific examples of polymers used as component (A) include cationized guar gum, cationized tara gum, cationized locust bean gum, cationic starch, cationized cellulose, cationized hydroxyalkylcellulose, cationized polyvinyl alcohol, polyethyleneimine, quaternized dialkylaminoalkyl(meth)acrylate polymers, diallyl quaternized ammonium salt polymers, methacrylamidepropyltrimethylammonium salt polymers, methacryloylethyltrimethylammonium salt polymers, vinylimidazolium trichloride-vinylpyrrolidone copolymer (polyquaternium-16), vinylpyrrolidone-alkylamino(meth)acrylate copolymers, vinylpyrrolidone-alkylamino(meth)acrylate-vinylcaprolactam copolymers, alkylacrylamide-(meth)acrylate-alkylaminoalkylacrylamide-polyethylene glycol(meth)acrylate copolymers, and adipic acid-dimethylaminohydroxypropylethylenetriamine copolymers, and one or more of these may be used.

[0023] Of the above, examples of cationized hydroxyalkyl cellulose include cationized hydroxyethyl cellulose and cationized hydroxypropyl cellulose, and examples of cationized hydroxyethyl cellulose include o-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethyl cellulose chloride (polyquaternium-10). Examples of quaternized dialkylaminoalkyl (meth)acrylate polymers include vinylpyrrolidone-N,N-dimethylaminoethyl diethyl methacrylate sulfate copolymer (Polyquaternium-11) and N,N-dimethylaminoethyl diethyl methacrylate sulfate-N,N-dimethylacrylamide-polyethylene glycol dimethacrylate copolymer (Polyquaternium-52). Examples of diallyl quaternized ammonium salt polymers include dimethyldiallylammonium chloride polymer (Polyquaternium-6), dimethyldiallylammonium chloride-acrylic acid copolymer (Polyquaternium-22), diallyldimethylammonium chloride-acrylamide copolymer (Polyquaternium-7), and acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39).

[0024] Examples of methacrylamide propyl trimethyl ammonium salt polymers include methacrylamide propyl trimethyl ammonium chloride polymer, vinylpyrrolidone-methacrylamido propyl trimethyl ammonium chloride copolymer, acrylic acid-methyl acrylate-methacrylamido propyl trimethyl ammonium chloride copolymer (Polyquaternium-47), and acrylic acid-acrylamide-methacrylamido propyl trimethyl ammonium chloride copolymer (Polyquaternium-53). Examples of methacryloylethyltrimethylammonium salt polymers include methacryloylethyltrimethylammonium chloride polymer (Polyquaternium-37), methacryloylethyldimethylbetaine-methacryloylethyltrimethylammonium chloride-methoxypolyethylene glycol methacrylate copolymer (Polyquaternium-49), and methacryloylethyldimethylbetaine-methacryloylethyltrimethylammonium chloride-2-hydroxyethyl methacrylate copolymer (Polyquaternium-48).

[0025] Component (A) can be used alone or in combination of two or more. Among the above, component (A) is a polymer having at least a cationic group from the viewpoints of ease of forming a polyion complex, stability of the emulsion composition, improvement of feel when applied to hair when used as a hair cosmetic composition, and suppression of hair frizz under high humidity conditions. From the viewpoints of the stability of the emulsion composition, the improvement of the feel when applied to hair when used as a hair cosmetic composition, and the suppression of hair frizz under high humidity conditions, component (A) is more preferably one or more selected from the group consisting of quaternized dialkylaminoalkyl (meth)acrylate polymers, diallyl quaternized ammonium salt polymers, methacrylamide propyl trimethyl ammonium salt polymers, methacryloyl ethyl trimethyl ammonium salt polymers, and vinylimidazolium trichloride-vinylpyrrolidone copolymers (polyquaternium-16), even more preferably one or more selected from the group consisting of diallyl quaternized ammonium salt polymers, methacrylamide propyl trimethyl ammonium salt polymers, and vinylimidazolium trichloride-vinylpyrrolidone copolymers (polyquaternium-16), and even more preferably dimethyldiallylammonium chloride. The polymer is preferably at least one selected from the group consisting of dimethyldiallylammonium chloride polymer (Polyquaternium-6), dimethyldiallylammonium chloride-acrylic acid copolymer (Polyquaternium-22), acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39), acrylic acid-methyl acrylate-methacrylamidopropyltrimethylammonium chloride copolymer (Polyquaternium-47), and vinylimidazolium trichloride-vinylpyrrolidone copolymer (Polyquaternium-16), and even more preferably at least one selected from the group consisting of dimethyldiallylammonium chloride polymer (Polyquaternium-6), acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39), and vinylimidazolium trichloride-vinylpyrrolidone copolymer (Polyquaternium-16).

[0026] Among the above, the preferred ranges of the cationic charge density and weight-average molecular weight of the following polymers are preferably as follows, from the viewpoints of ease of forming a polyion complex, stability of the emulsion composition, improvement of feel when applied to hair when used as a hair cosmetic composition, and suppression of hair frizz under high humidity conditions. The cationic charge density of the dimethyldiallylammonium chloride polymer (Polyquaternium-6) is more preferably 2.0 meq / g or more, even more preferably 2.5 meq / g or more, and even more preferably 6.5 meq / g or less, and the weight-average molecular weight is more preferably 10,000 or more and 200,000 or less. The cationic charge density of the dimethyldiallylammonium chloride-acrylic acid copolymer (Polyquaternium-22) is more preferably 2.0 meq / g or more, even more preferably 3.0 meq / g or more, even more preferably 4.0 meq / g or more, even more preferably 6.5 meq / g or less, even more preferably 6.0 meq / g or less. The weight-average molecular weight is more preferably 20,000 or more, even more preferably 50,000 or more, even more preferably 100,000 or more, even more preferably 200,000 or more, even more preferably 300,000 or more, even more preferably 1 million or less, even more preferably 600,000 or less, even more preferably 500,000 or less. The cationic charge density of the acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39) is more preferably 2.0 meq / g or more, even more preferably 2.5 meq / g or more, even more preferably 6.5 meq / g or less, even more preferably 5.0 meq / g or less, even more preferably 4.0 meq / g or less. The weight-average molecular weight is more preferably 20,000 or more, even more preferably 50,000 or more, even more preferably 100,000 or more, and even more preferably 1,000,000 or less, even more preferably 600,000 or less, even more preferably 500,000 or less, even more preferably 300,000 or less. The cationic charge density of the acrylic acid-methyl acrylate-methacrylamidopropyltrimethylammonium chloride copolymer (Polyquaternium-47) is more preferably 2.0 meq / g or more, even more preferably 2.5 meq / g or more, even more preferably 6.5 meq / g or less, even more preferably 5.0 meq / g or less, even more preferably 4.5 meq / g or less. The weight-average molecular weight is more preferably 200,000 or more, even more preferably 500,000 or more, even more preferably 1 million or more, and preferably 5 million or less, more preferably 3 million or less, even more preferably 1.5 million or less. The cationic charge density of vinylimidazolium trichloride-vinylpyrrolidone copolymer (Polyquaternium-16) is more preferably 2.0 meq / g or more, more preferably 6.5 meq / g or less, more preferably 5.0 meq / g or less, and even more preferably 4.5 meq / g or less. The weight-average molecular weight is more preferably 20,000 or more, more preferably 50,000 or more, and even more preferably 150,000 or less.

[0027] Commercially available polymers can also be used as component (A). Specific examples include "MERQUAT 2001 Polymer" (acrylic acid, methyl acrylate, and methacrylamide propyl trimethyl ammonium chloride copolymer; polyquaternium-47, cationic charge density: 3.21 meq / g, Mw: 1.3 million), "MERQUAT 100" (dimethyldiallyl ammonium chloride polymer; polyquaternium-6, cationic charge density: 6.18 meq / g, Mw: 150,000), "MERQUAT 106" (dimethyldiallyl ammonium chloride polymer; polyquaternium-6, cationic charge density: 6.18 meq / g, Mw: 15,000), "MERQUAT 3940 POLYMER" (acrylamide, acrylic acid, and dimethyldiallyl ammonium chloride copolymer; polyquaternium-39, cationic charge density: 2.97 meq / g, Mw: 150,000), and "MERQUAT 280" (dimethyldiallylammonium chloride-acrylic acid copolymer solution; Polyquaternium-22, cationic charge density: 4.99 meq / g, Mw: 450,000), "MERQUAT 295" (dimethyldiallylammonium chloride-acrylic acid copolymer solution; Polyquaternium-22, cationic charge density: 6.04 meq / g, Mw: 190,000), "MERQUAT 2003PR Polymer" (acrylic acid-acrylamide-methacrylamidopropyltrimethylammonium chloride; Polyquaternium-53), "MERQUAT 550" (diallyldimethylammonium chloride-acrylamide copolymer: Polyquaternium-7), "MERQUAT 740" (diallyldimethylammonium chloride-acrylamide copolymer: Polyquaternium-7, cationic charge density: 2.59 meq / g, Mw: 120,000), and "Rubycut FC" manufactured by BASF SE. 550" (vinyl imidazolium trichloride-vinyl pyrrolidone copolymer; polyquaternium-16, cationic charge density: 3.91 meq / g, Mw: 80,000), "Rubicat Excellnce" (vinyl imidazolium trichloride-vinyl pyrrolidone copolymer; polyquaternium-16, cationic charge density: 6.65 meq / g, Mw: 40,000), "Rubycut FC 370" (vinyl imidazolium trichloride-vinyl pyrrolidone copolymer; polyquaternium-16, cationic charge density: 2.48 meq / g, Mw: 100,000), "Poise" manufactured by Kao Corporation. Examples include Kao Corporation's "C-60H" (vinyl imidazolium trichloride-vinyl pyrrolidone copolymer; Polyquaternium-16, cationic charge density: 1.5 meq / g, Mw: 600,000), Kao Corporation's "KP Polymer E" (methacryloylethyl trimethylammonium chloride polymer (Polyquaternium-37), cationic charge density: 4.8 meq / g, Mw: 300,000), Goo Chemical Industry Co., Ltd.'s "Plussize L-440" and "Plussize L-440W" (methacryloylethyl dimethyl betaine-methacryloylethyl trimethylammonium chloride-methoxy polyethylene glycol methacrylate copolymer; Polyquaternium-49), and "Plussize L-450" and "Plussize L-450W" (methacryloylethyl dimethyl betaine-methacryloylethyl trimethylammonium chloride-2-hydroxyethyl methacrylate copolymer; Polyquaternium-48).

[0028] (Component (B): Anionic Polymer) Component (B) is a polymer capable of forming a polyion complex through interaction with component (A). In this specification, "anionic polymer" refers to a polymer that has anionic groups and is substantially free of cationic groups and amphoteric groups. "Substantially free of cationic groups and amphoteric groups" means that the molar ratio of cationic groups and amphoteric groups to anionic groups is preferably 0.1% or less.

[0029] The anionic group contained in component (B) is preferably an acidic group such as a carboxyl group, a sulfonic acid group, or a phosphate group, and is more preferably a carboxyl group from the viewpoint of facilitating the formation of a polyion complex through interaction with component (A) and from the viewpoint of availability. Note that in component (B), at least a portion of the anionic group may be neutralized and in the form of a salt.

[0030] The anionic charge density of component (B) is preferably 0.1 meq / g or more, more preferably 0.5 meq / g or more, even more preferably 1.0 meq / g or more, and even more preferably 2.0 meq / g or more from the viewpoint of facilitating the formation of a polyion complex through interaction with component (A), and is preferably 30 meq / g or less, more preferably 20 meq / g or less, and even more preferably 15 meq / g or less from the viewpoint of the stability of the emulsion composition. The anionic charge density of component (B) is preferably 0.1 meq / g or more and 30 meq / g or less, more preferably 0.5 meq / g or more and 30 meq / g or less, even more preferably 1.0 meq / g or more and 20 meq / g or less, and even more preferably 2.0 meq / g or more and 15 meq / g or less. The anionic charge density of component (B) can be calculated by (the number of moles of anionic groups contained per gram of polymer) × 1000 (meq / g). When at least a portion of the anionic groups in component (B) are in the form of neutralized salts, the number of moles of the anionic groups includes the number of moles of the anionic groups in the form of salts. The emulsion composition may contain two or more polymers as component (B). In this case, the anionic charge density of component (B) is determined by calculating a weighted average of the anionic charge densities and blending amounts of each polymer.

[0031] From the viewpoints of ease of polyion complex formation, stability of the emulsion composition, improved feel upon application to hair when used as a hair cosmetic composition, and suppression of hair frizz under high-humidity conditions, the weight-average molecular weight (Mw) of component (B) is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 10,000 or more, and preferably 50,000 or less, more preferably 40,000 or less, even more preferably 30,000 or less. The weight-average molecular weight (Mw) of component (B) is preferably 3,000 or more and 50,000 or less, more preferably 5,000 or more and 40,000 or less, even more preferably 10,000 or more and 30,000 or less. The weight-average molecular weight of component (B) can be measured by gel permeation chromatography (GPC).

[0032] Examples of the polymer having a carboxy group used as component (B) include a carboxy group-containing cellulose derivative, a carboxyvinyl polymer, poly(meth)acrylic acid, a (meth)acrylic acid copolymer, or a salt thereof. Here, "(meth)acrylic acid" means acrylic acid or methacrylic acid. Among the above, examples of the carboxy group-containing cellulose derivatives include carboxymethyl cellulose, carboxyethyl cellulose, carboxymethyl ethyl cellulose, and salts thereof. Examples of (meth)acrylic acid copolymers include (meth)acrylic acid / maleic acid copolymer, (meth)acrylic acid / itaconic acid copolymer, (meth)acrylic acid / fumaric acid copolymer, (meth)acrylic acid / vinyl acetate copolymer, (meth)acrylic acid / 2-hydroxyethyl methacrylate copolymer, (meth)acrylic acid / (meth)acrylic acid alkyl ester copolymer, acrylic acid / acrylic acid alkyl ester / (N-alkyl)acrylamide copolymer, (meth)acrylic acid / (meth)acrylic acid alkyl ester copolymer, (acrylic acid / diacetoneacrylamide) copolymer AMP, (acrylic acid / acrylic acid alkyl ester / diacetoneacrylamide) copolymer AMP, (meth)acrylic acid / acrylic acid alkyl ester / polyvinylpyrrolidone copolymer, 2-ethylhexyl acrylate-methyl acrylate-acrylic acid-glycidyl methacrylate copolymer, or salts thereof. Examples of the (meth)acrylic acid / (meth)acrylic acid alkyl ester copolymer include copolymers of (meth)acrylic acid and (meth)acrylic acid alkyl esters having an alkyl group having 1 to 24 carbon atoms, preferably 8 to 22 carbon atoms, such as (acrylic acid / octyl acrylate) copolymer and (acrylic acid / stearyl acrylate) copolymer.

[0033] Component (B) can be used alone or in combination of two or more. Among the above, from the viewpoints of ease of forming a polyion complex, stability of the emulsion composition, improvement of feel when applied to hair, and suppression of hair frizz under high humidity conditions, component (B) is preferably one or more selected from the group consisting of poly(meth)acrylic acid, (meth)acrylic acid copolymers, or salts thereof, more preferably one or more selected from the group consisting of polyacrylic acid, (meth)acrylic acid / (meth)acrylic acid alkyl ester copolymers, or salts thereof, and even more preferably one or more selected from the group consisting of polyacrylic acid, (acrylic acid / stearyl acrylate) copolymers, or salts thereof.

[0034] Commercially available polymers can also be used as component (B). Specific examples include "Carbopol 980" and "Carbopol 981" (carboxyvinyl polymers) manufactured by Lubrizol Advanced Materials, Inc., "Accusol 445G Polymer" (sodium polyacrylate) manufactured by The Dow Chemical Company, and "Softcare" manufactured by Kao Corporation. Examples of suitable copolymers include "SA-37W" (acrylic acid / stearyl acrylate copolymer), "Diahold" ((meth)acrylic acid / (meth)acrylic acid alkyl ester copolymer) manufactured by Mitsubishi Chemical Corporation, "Ultrahold 8", "Ultrahold Strong", and "Ultrahold Power" manufactured by BASF Japan Ltd., "Amphomer V-42" (acrylic acid / acrylic acid alkyl ester / (N-alkyl)acrylamide copolymer) manufactured by National Starch Co., Ltd., "Plussize L-53P", "Plussize L-75CB", "Plussize L-9540B", "Plussize L-6466", and "Plussize L-3200B" ((acrylic acid / diacetoneacrylamide) copolymer AMP or (acrylic acid / acrylic acid alkyl ester / diacetoneacrylamide) copolymer AMP) manufactured by Goo Chemical Industry Co., Ltd., and "Rubyflex VBM35" ((meth)acrylic acid / acrylic acid alkyl ester / polyvinylpyrrolidone copolymer) manufactured by BASF.

[0035] (Component (C): Organic acid) In step (1), component (C) contributes to the stable formation of a polyion complex in mixture A. It is believed that component (C) weakens the ionic interaction between component (A) and component (B), allowing the polyion complex to disperse in water without agglomerating. The organic acid of component (C) includes carboxylic acid compounds and sulfonic acid compounds other than component (B). From the viewpoint of distinguishing component (C) from component (B), component (C) is preferably a compound having a molecular weight of 500 or less, more preferably 200 or less.

[0036] Examples of carboxylic acid compounds used as component (C) include aliphatic monocarboxylic acids having 4 or less carbon atoms, such as acetic acid, propionic acid, and butanoic acid; aromatic monocarboxylic acids, such as benzoic acid; aliphatic dicarboxylic acids, such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and fumaric acid; aromatic dicarboxylic acids, such as phthalic acid and isophthalic acid; polycarboxylic acids, such as polyglutamic acid; hydroxycarboxylic acids, such as lactic acid, malic acid, glycolic acid, hydroxyacrylic acid, glyceric acid, tartaric acid, and citric acid; and acidic amino acids, such as glutamic acid and aspartic acid. One or more of these may be used. Examples of sulfonic acid compounds used as component (C) include aliphatic sulfonic acids such as methanesulfonic acid and ethanesulfonic acid; aromatic sulfonic acids such as p-toluenesulfonic acid and naphthalenesulfonic acid; and the like, and one or more of these can be used.

[0037] From the viewpoint of stably forming a polyion complex in step (1) and forming a highly stable emulsion composition through step (2), as well as from the viewpoint of use in a cosmetic composition, component (C) is preferably one or more selected from the group consisting of aliphatic dicarboxylic acids, hydroxycarboxylic acids, and aromatic sulfonic acids, more preferably one or more selected from the group consisting of succinic acid, lactic acid, malic acid, glycolic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid, even more preferably one or more selected from the group consisting of succinic acid and lactic acid, and even more preferably lactic acid. At least a portion of component (C) may be in the form of an organic acid salt when blended. From the viewpoints of use in cosmetic compositions and easy availability, the salt of the organic acid is preferably an alkali metal salt or alkaline metal salt of the organic acid, more preferably an alkali metal salt, even more preferably one or more selected from the group consisting of sodium salts and potassium salts, and even more preferably a sodium salt. From the viewpoints of ease of polyion complex formation, stability of the emulsion composition, improved feel upon application to hair when used as a hair cosmetic composition, and suppression of hair frizz under high-humidity conditions, the proportion of organic acid salt in component (C) is preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 35% by mass or less, still more preferably 20% by mass or less, still more preferably 10% by mass or less, still more preferably 5% by mass or less, still more preferably 2% by mass or less, and may even be 0% by mass. The proportion (% by mass) of organic acid salt in component (C) referred to here means % by mass converted into organic acid.

[0038] (Component (D): water) Deionized water or distilled water is preferred as component (D). However, tap water or groundwater sterilized with hypochlorous acid or the like may also be used as long as it does not impair the stability of the emulsion composition.

[0039] In addition to the components (A) to (D) used in step (1), the emulsion composition preferably contains an ionic surfactant and an amphiphilic substance having a hydrophobic group as emulsion-forming components. In particular, when the emulsion composition is used as a hair cosmetic composition, particularly a hair rinse, hair conditioner, hair treatment, or hair styling agent, cationic surfactants are preferred as the ionic surfactant, and higher alcohols are preferred as the amphiphilic substance having a hydrophobic group, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment. That is, the emulsion composition preferably contains, as emulsion-forming components, component (E): a cationic surfactant and component (F): a higher alcohol. Furthermore, the emulsion composition may optionally contain component (G): an oily agent and component (H): an aqueous medium.

[0040] (Component (E): Cationic surfactant) The cationic surfactant, component (E), is an emulsion-forming component contained in the oil phase of the emulsion composition. Examples of the cationic surfactant include (i) alkyltrimethylammonium salts, (ii) alkoxyalkyltrimethylammonium salts, (iii) dialkyldimethylammonium salts, (iv) alkylamidoalkyltrimethylammonium salts, (v) alkyldimethylamines and salts thereof, (vi) alkoxyalkyldimethylamines and salts thereof, and (vii) alkylamidoalkyldimethylamines and salts thereof.

[0041] (i) Examples of alkyltrimethylammonium salts include alkyltrimethylammonium salts having an alkyl group preferably having from 12 to 22 carbon atoms, more preferably from 16 to 20 carbon atoms. Specific examples include cetyltrimethylammonium chloride (cetrimonium chloride), stearyltrimethylammonium chloride (steartrimonium chloride), and behenyltrimethylammonium chloride (behentrimonium chloride). (ii) Examples of alkoxyalkyltrimethylammonium salts include alkoxyalkyltrimethylammonium salts having an alkoxy group preferably having from 12 to 22 carbon atoms, more preferably from 16 to 20 carbon atoms. Specific examples include stearoxypropyltrimethylammonium chloride, stearoxyethyltrimethylammonium chloride, and stearoxyhydroxypropyltrimethylammonium chloride. (iii) Examples of dialkyldimethylammonium salts include dialkyldimethylammonium salts having an alkyl group preferably having 12 to 22 carbon atoms, more preferably 16 to 20 carbon atoms, and specific examples thereof include distearyldimethylammonium chloride. (iv) Examples of alkylamidoalkyltrimethylammonium salts include alkylamidoalkyltrimethylammonium salts in which the number of alkyl carbon atoms in the alkylamido moiety is preferably 11 or more and 21 or less, more preferably 13 or more and 19 or less, and specific examples thereof include palmitamidopropyltrimethylammonium chloride (palmitamidopropyltrimonium chloride).

[0042] (v) Alkyldimethylamine, (vi) alkoxyalkyldimethylamine, and (vii) alkylamidoalkyldimethylamine react with an acid to form a tertiary amine salt, which becomes a cationic surfactant. The alkyl group in (v) alkyldimethylamine and salts thereof, and the alkoxy group in (vi) alkoxyalkyldimethylamine and salts thereof preferably have 12 or more and 22 or less carbon atoms, more preferably 16 or more and 20 or less carbon atoms. (vii) The number of alkyl carbon atoms in the alkylamide moiety of the alkylamido alkyldimethylamine and its salt is preferably 11 or more and 21 or less, more preferably 15 or more and 19 or less.

[0043] The amines (v) to (vii) may be reacted with an acid in advance to form a salt and then incorporated into the emulsion composition. Alternatively, the amines may be incorporated into the emulsion composition as they are, and then an acid may be incorporated into the emulsion composition to form a salt therein. Therefore, the above amines and their salts are defined herein as cationic surfactants. The content or amount of the amines is calculated in terms of the mass of the amine. Examples of the amine salts (v) to (vii) include salts with organic or inorganic acids. Examples of organic acids include monocarboxylic acids such as acetic acid and propionic acid; dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, and phthalic acid; polycarboxylic acids such as polyglutamic acid; hydroxycarboxylic acids such as glycolic acid, lactic acid, hydroxyacrylic acid, glyceric acid, malic acid, tartaric acid, and citric acid; and acidic amino acids such as glutamic acid and aspartic acid. Examples of inorganic acids include hydrochloric acid, sulfuric acid, and phosphoric acid. Among these, organic acids are preferred, and one or more selected from the group consisting of dicarboxylic acids, hydroxycarboxylic acids, and acidic amino acids are more preferred. The dicarboxylic acid is more preferably one or more selected from the group consisting of maleic acid and succinic acid. The hydroxycarboxylic acid is more preferably one or more selected from the group consisting of glycolic acid, lactic acid, and malic acid. The acidic amino acid is more preferably glutamic acid.

[0044] (v) Examples of alkyldimethylamines and salts thereof include N,N-dimethylbehenylamine, N,N-dimethylstearylamine, and organic acid salts thereof, with N,N-dimethylbehenylamine lactate and N,N-dimethylstearylamine glycolate being preferred.

[0045] (vi) Examples of alkoxyalkyldimethylamines and salts thereof include N,N-dimethyl-3-hexadecyloxypropylamine, N,N-dimethyl-3-octadecyloxypropylamine (stearoxypropyldimethylamine), and organic acid salts thereof, and N,N-dimethyl-3-hexadecyloxypropylamine or a lactate thereof, and N,N-dimethyl-3-octadecyloxypropylamine (stearoxypropyldimethylamine) or a lactate thereof are preferred.

[0046] (vii) Examples of alkylamidoalkyldimethylamines and salts thereof include N-[3-(dimethylamino)propyl]docosanamide, N-[3-(dimethylamino)propyl]stearamide, and organic acid salts thereof, and preferred are the lactate salt of N-[3-(dimethylamino)propyl]docosanamide and the glycolate salt of N-[3-(dimethylamino)propyl]stearamide.

[0047] The component (E) can be used alone or in combination of two or more. Among the above, from the viewpoint of further improving the feel on application to hair and the feel on hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent, component (E) is preferably at least one selected from the group consisting of (i) alkyltrimethylammonium salts, (ii) alkoxyalkyltrimethylammonium salts, (iii) dialkyldimethylammonium salts, (iv) alkylamidoalkyltrimethylammonium salts, (v) alkyldimethylamines and salts thereof, (vi) alkoxyalkyldimethylamines and salts thereof, and (vii) alkylamidoalkyldimethylamines and salts thereof, and more preferably (ii) alkoxyalkyltrimethylammonium salts. and (v) one or more selected from the group consisting of alkyl dimethylamines and salts thereof, more preferably one or more selected from the group consisting of stearoxypropyltrimethylammonium chloride, stearoxyethyltrimethylammonium chloride, stearoxyhydroxypropyltrimethylammonium chloride, N,N-dimethyl-3-hexadecyloxypropylamine or a lactate thereof, and N,N-dimethyl-3-octadecyloxypropylamine (stearoxypropyldimethylamine) or a lactate thereof, and even more preferably one or more selected from the group consisting of stearoxypropyltrimethylammonium chloride and N,N-dimethyl-3-octadecyloxypropylamine (stearoxypropyldimethylamine) or a lactate thereof.

[0048] (Component (F): Higher alcohol) The higher alcohol, component (F), is an emulsion-forming component contained in the oil phase of the emulsion composition. Component (F) includes an aliphatic monohydric alcohol having 12 or more carbon atoms, preferably 12 to 22 carbon atoms. Examples of the higher alcohol include one or more selected from the group consisting of lauryl alcohol, cetyl alcohol, myristyl alcohol, oleyl alcohol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, behenyl alcohol, and cetostearyl alcohol. Among the above, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent, preferred is one or more alcohols selected from the group consisting of cetyl alcohol, myristyl alcohol, stearyl alcohol, and behenyl alcohol, and more preferred is stearyl alcohol.

[0049] (Component (G): Oil) The oily agent, component (G), is a component contained in the oil phase of the emulsion composition other than component (F). Component (G) may be blended into the oil phase components containing the emulsion-forming components, or may be blended as another oil phase component. Examples of component (G) include (a) silicone oil, (b) ester oil, (c) ether oil, (d) hydrocarbon oil, (e) higher fatty acid, and (f) waxes, and one or more of these can be used.

[0050] (a) The silicone oil is preferably at least one selected from the group consisting of dimethylpolysiloxane (dimethicone), dimethiconol (dimethylpolysiloxane having a terminal hydroxy group), methylphenylpolysiloxane, and modified silicone. Examples of modified silicones include amino-modified silicones (dimethylpolysiloxanes having an amino group, such as amodimethicone), polyether-modified silicones, aminopolyether-modified silicones (silicones having an amino group and a polyether structure), glyceryl-modified silicones, carboxy-modified silicones, fatty acid-modified silicones, alcohol-modified silicones, aliphatic alcohol-modified silicones, epoxy-modified silicones, fluorine-modified silicones, and alkyl-modified silicones. Among the above, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent, (a) the silicone oil is preferably one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, methylphenylpolysiloxane, and modified silicone, more preferably one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, amino-modified silicone, polyether-modified silicone, and aminopolyether-modified silicone, and even more preferably one or more selected from the group consisting of dimethylpolysiloxane, amino-modified silicone, and aminopolyether-modified silicone.

[0051] (b) Examples of ester oils include synthetic ester oils and natural fats and oils, such as esters of monocarboxylic acids and monohydric alcohols, esters of monocarboxylic acids and polyhydric alcohols, and esters of polycarboxylic acids and monohydric alcohols.

[0052] Examples of the ester of a monovalent carboxylic acid and a monohydric alcohol include esters represented by the following general formula (1). R 1 -COO-R 2 (1) In general formula (1), R 1 represents a linear or branched alkyl or alkenyl group having 1 to 25 carbon atoms, or an aromatic hydrocarbon group having 6 to 24 carbon atoms, which may be substituted with a hydroxyl group, and R 2 represents a linear or branched alkyl or alkenyl group having 1 to 30 carbon atoms.

[0053] R 1 When is an alkyl group or an alkenyl group, it preferably has 7 or more carbon atoms and preferably 23 or less, more preferably 21 or less, even more preferably 19 or less, and still more preferably 17 or less. R 1When is an aromatic hydrocarbon group, the number of carbon atoms is preferably 6 or more and preferably 22 or less, more preferably 20 or less. R 2 The number of carbon atoms is preferably 2 or more, and preferably 28 or less, more preferably 24 or less, and even more preferably 20 or less. Even more preferably, in general formula (1), R 1 is a linear or branched alkyl group having 7 to 17 carbon atoms, and R 2 is a straight-chain or branched-chain alkyl group having 2 to 24 carbon atoms.

[0054] Specific examples of the ester represented by general formula (1) include cetyl isooctanoate, stearyl isooctanoate, isononyl isononanoate, isotridecyl isononanoate, hexyl laurate, isostearyl laurate, butyl myristate, isopropyl myristate, decyl myristate, isotridecyl myristate, isocetyl myristate, isostearyl myristate, 2-octyldodecyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, and isostearyl palmitate. Examples of the alkyl esters include one or more selected from the group consisting of allyl, 2-hexyldecyl palmitate, 2-ethylhexyl stearate, 2-hexyldecyl stearate, isopropyl isostearate, 2-hexyldecyl isostearate, ethyl oleate, isodecyl oleate, oleyl oleate, octyldodecyl oleate, ethyl linoleate, isopropyl linoleate, lanolin acetate, methyl castor oil fatty acid (methyl ricinoleate), and alkyl benzoate (alkyl having 12 to 15 carbon atoms).

[0055] Examples of the ester of a monocarboxylic acid and a monohydric alcohol include an ester represented by the following general formula (2). R 3 -COO-(AO) n -R 4 (2) In general formula (2), R 3represents a linear or branched alkyl or alkenyl group having 1 to 25 carbon atoms, which may be substituted with a hydroxyl group; R 4 represents an aromatic hydrocarbon group having 6 to 24 carbon atoms, AO represents an alkyleneoxy group having 2 to 4 carbon atoms, and n represents the average number of moles added of 1 to 50. R 3 is preferably an alkyl group having 7 or more carbon atoms and preferably 23 or less, more preferably 21 or less, and even more preferably 19 or less. R 4 is preferably an aromatic-containing hydrocarbon group having 6 or more carbon atoms and 22 or less, more preferably 20 or less, even more preferably 18 or less, and even more preferably a benzyl group. The AO group is preferably a propyleneoxy group, and n is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less. Specific examples of the ester represented by general formula (2) include an ester of myristic acid and a 3-mol propylene oxide adduct of benzyl alcohol ("Crodamol STS" manufactured by Croda), an ester of 2-ethylhexanoic acid and a 3-mol propylene oxide adduct of benzyl alcohol ("Crodamol SFX" manufactured by Croda), and the like.

[0056] Examples of the ester of a monovalent carboxylic acid and a polyhydric alcohol include the ester represented by the following general formula (3). R 5 -(OCOR 6 ) p (3) In general formula (3), R 5 represents a polyhydric alcohol residue, preferably a hydrocarbon group having 2 to 10 carbon atoms, and R 6 represents a monocarboxylic acid residue having 1 to 25 carbon atoms, and p represents an integer of 2 to 10. In addition, R 5 may have an ether bond, but is preferably a straight-chain or branched-chain hydrocarbon group having from 2 to 10 carbon atoms. Also, p is the same number as the number of hydroxy groups in the polyhydric alcohol. R 6is preferably an alkyl group having 7 or more carbon atoms, and from the same viewpoint as above, preferably 23 or less, more preferably 21 or less, and even more preferably 19 or less. Even more preferably, in general formula (3), R 5 is a glycerin residue or a pentaerythritol residue, and R 6 is an ester in which the alkyl group has 7 to 19 carbon atoms.

[0057] Specific examples of the ester represented by general formula (3) include propylene glycol dicaprate, propylene glycol dioleate, neopentyl glycol dicaprate, neopentyl glycol di-2-ethylhexanoate, propanediol di(caprylic / capric acid), propanediol diisostearate, ethylene glycol di-2-ethylhexanoate, glyceryl tri(caprylic / capric acid), glyceryl tri-2-ethylhexanoate, glyceryl tri-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, and natural fats and oils. Examples of natural fats and oils include triglycerides such as avocado oil, olive oil, sesame oil, rice bran oil, safflower oil, soybean oil, corn oil, rapeseed oil, castor oil, cottonseed oil, and mink oil.

[0058] Examples of the ester of a polycarboxylic acid and a monohydric alcohol include an ester represented by the following general formula (4). R 7 -(COOR 8 ) q (4) In general formula (4), R 7 is a polycarboxylic acid residue having 2 to 10 carbon atoms, and R 8 represents a monohydric alcohol residue having 1 to 24 carbon atoms, and q is an integer of 2 to 10. Furthermore, q is the same number as the number of carboxy groups in the polycarboxylic acid. R 8has preferably 3 or more carbon atoms, more preferably 6 or more carbon atoms, and from the same viewpoint as above, preferably 22 or less, more preferably 20 or less, and even more preferably 18 or less carbon atoms. Even more preferably, in general formula (4), R 7 is a trimellitic acid residue, and R 8 is an ester in which the alkyl group is a branched chain alkyl group having 6 to 18 carbon atoms.

[0059] Specific examples of the ester represented by general formula (4) include diisostearyl malate, di-2-ethylhexyl succinate, diisobutyl adipate, di-2-heptylundecyl adipate, di-2-ethylhexyl sebacate, diisopropyl sebacate, and tri-2-ethylhexyl trimellitate.

[0060] Among these, from the viewpoint of further improving the feel on application to hair and the feel on hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent, preferred are esters of monocarboxylic acids and monohydric alcohols represented by general formula (1), esters of monocarboxylic acids and polyhydric alcohols represented by general formula (3), or esters of polycarboxylic acids and monohydric alcohols represented by general formula (4), and more preferred are esters of monocarboxylic acids and monohydric alcohols represented by general formula (1) 1 is a linear or branched alkyl group having 7 to 17 carbon atoms, and R 2 is a linear or branched alkyl group having 2 to 24 carbon atoms; 5 is a glycerol residue, and R 6 is an alkyl group having 7 to 19 carbon atoms, and in general formula (4), R 7 is a trimellitic acid residue, and R 8 is at least one selected from the group consisting of esters in which the alkyl group is a branched chain alkyl group having 6 to 18 carbon atoms.

[0061] (c) The ether oil may be a dialkyl ether compound represented by the following general formula (5) or a polyoxyalkylene alkyl ether compound represented by the following general formula (6). R 9 -OR 10 (5) In general formula (5), R 9 and R 10 each independently represents a linear or branched alkyl or alkenyl group having 6 to 22 carbon atoms, or an aromatic hydrocarbon group having 6 to 24 carbon atoms. R 9 and R 10 is preferably an alkyl group, and has the number of carbon atoms thereof preferably 8 or more and preferably 18 or less, more preferably 16 or less, and even more preferably 12 or less, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, a hair conditioner, a hair treatment, or a hair styling agent.

[0062] R 11 -O-(PO)r(EO)sH (6) In general formula (6), R 11 represents an alkyl or alkenyl group having 6 to 22 carbon atoms, PO represents a propyleneoxy group, and EO represents an ethyleneoxy group. r represents the average number of moles added of 0.1 to 15, and s represents the average number of moles added of 0 to 10. When s is not 0, the addition of PO and EO may be random or block. R 11 The number of carbon atoms is preferably 8 or more, and preferably 20 or less, more preferably 18 or less, and even more preferably 12 or less. From the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, a hair conditioner, a hair treatment, or a hair styling agent, the average number of added moles r is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and is preferably 13 or less, more preferably 10 or less, and the average number of added moles s is preferably 5 or less, more preferably 1 or less, even more preferably 0. The polyoxyalkylene alkyl ether compound represented by general formula (6) is preferably at least one selected from the group consisting of polypropylene glycol, polyoxypropylene octyl ether, polyoxypropylene decyl ether, and polyoxypropylene lauryl ether, each of which has an average molar number r of propyleneoxy groups added of 3 or more and 10 or less.

[0063] (d) Examples of hydrocarbon oils include squalene, squalane, liquid paraffin, liquid isoparaffin, isohexadecane, isoeicosane, hydrogenated polyisobutene, light liquid isoparaffin, heavy liquid isoparaffin, α-olefin oligomer, and cycloparaffin.

[0064] (e) Examples of higher fatty acids include fatty acids having 8 or more carbon atoms, preferably 12 or more carbon atoms, such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, coconut oil fatty acid, lanolin fatty acid, isostearic acid, and isopalmitic acid.

[0065] (f) Waxes include beeswax, spermaceti, lanolin, carnauba wax, and the like.

[0066] The oily agent, component (G), can be one or more of the above. Among the above, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent, it is preferably one or more selected from the group consisting of (a) silicone oil, (b) ester oil, (d) hydrocarbon oil, and (e) higher fatty acid, more preferably one or more selected from the group consisting of (a) silicone oil and (e) higher fatty acid, and even more preferably one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, methylphenylpolysiloxane, modified silicone, and fatty acid having 12 or more carbon atoms. and even more preferably contains one or more selected from the group consisting of dimethylpolysiloxane, dimethiconol, amino-modified silicone, polyether-modified silicone, aminopolyether-modified silicone, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, coconut oil fatty acid, lanolin fatty acid, isostearyl acid, and isopalmitic acid, even more preferably contains one or more selected from the group consisting of dimethylpolysiloxane, amino-modified silicone, aminopolyether-modified silicone, and lanolin fatty acid, and even more preferably consists of dimethylpolysiloxane, amino-modified silicone, and lanolin fatty acid.

[0067] (Component (H): aqueous medium) The aqueous medium of component (H) refers to an aqueous medium other than water. Component (H) is a component contained in the aqueous phase of the emulsion composition, but may also be blended into the oil phase components containing emulsion-forming components. Examples of component (H) include lower alcohols such as ethanol and isopropyl alcohol, and low-molecular-weight diols and triols having 6 or less carbon atoms such as 1,3-butylene glycol, glycerin, ethylene glycol, propylene glycol, and dipropylene glycol. These may be used alone or in combination of two or more.

[0068] (Blend amount) The blending amount or content of each component in the emulsion composition is preferably as follows, from the viewpoints of the stability of the emulsion composition, improving the feel when applied to hair, and suppressing frizz of hair under high humidity conditions.

[0069] The amount of component (A) in the emulsion composition is preferably at least 0.01% by mass, more preferably at least 0.02% by mass, and even more preferably at least 0.03% by mass, based on the total amount of the emulsion composition (100% by mass), from the viewpoints of ease of polyion complex formation, improved feel upon application to hair when the resulting emulsion composition is used as a hair cosmetic composition, and suppression of hair spread under high-humidity conditions. Furthermore, from the viewpoints of improving the emulsified state and improving the feel upon application to hair when the resulting emulsion composition is used as a hair cosmetic composition, the amount is preferably less than 0.50% by mass, more preferably 0.30% by mass or less, and even more preferably 0.20% by mass or less. The amount of component (A) in the emulsion composition is preferably at least 0.01% by mass but less than 0.50% by mass, more preferably at least 0.02% by mass but less than 0.30% by mass, and even more preferably at least 0.03% by mass but less than 0.20% by mass, based on the total amount of the emulsion composition (100% by mass).

[0070] The amount of component (B) in the emulsion composition is preferably 0.010% by mass or more, more preferably 0.015% by mass or more, based on the total amount (100% by mass) of the emulsion composition, from the viewpoints of ease of formation of a polyion complex, improvement of the feel when applied to hair when the resulting emulsion composition is used as a hair cosmetic composition, and suppression of hair spread under high-humidity conditions. Furthermore, from the viewpoints of improving the emulsified state and improving the feel when applied to hair when the resulting emulsion composition is used as a hair cosmetic composition, the amount is preferably less than 0.50% by mass, more preferably 0.30% by mass or less, even more preferably 0.20% by mass or less, still more preferably 0.15% by mass or less, and even more preferably 0.10% by mass or less. The amount of component (B) blended into the emulsion composition is preferably 0.010% by mass or more but less than 0.50% by mass, more preferably 0.010% by mass or more but less than 0.30% by mass, even more preferably 0.015% by mass or more but less than 0.20% by mass, still more preferably 0.015% by mass or more but less than 0.15% by mass, and even more preferably 0.015% by mass or more but less than 0.10% by mass, based on the total amount of the emulsion composition (100% by mass).

[0071] The total amount of component (A) and component (B) in the emulsion composition is less than 1.0% by mass, preferably 0.9% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.3% by mass or less, based on the total amount (100% by mass) of the emulsion composition, from the viewpoint of stability of the emulsion composition. Furthermore, from the viewpoint of suppressing hair frizz under high-humidity conditions when the resulting emulsion composition is used as a hair cosmetic composition, the total amount is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more. The total amount of component (A) and component (B) in the emulsion composition is less than 1.0 mass% of the total amount of the emulsion composition (100 mass%), and is preferably 0.01 mass% or more and 0.9 mass% or less, more preferably 0.03 mass% or more and 0.9 mass% or less, even more preferably 0.05 mass% or more and 0.9 mass% or less, still more preferably 0.05 mass% or more and 0.5 mass% or less, and even more preferably 0.05 mass% or more and 0.3 mass% or less.

[0072] In the emulsion composition, the ratio of the number of moles of cationic charge of component (A) to the number of moles of anionic charge of component (B) is preferably 5 / 95 to 95 / 5, more preferably 10 / 90 to 90 / 10, even more preferably 20 / 80 to 80 / 20, still more preferably 20 / 80 to 60 / 40, and even more preferably 40 / 60 to 60 / 40, from the viewpoint of improving the emulsified state and improving the feel when applied to hair when used as a hair cosmetic composition.

[0073] The amount of component (C) blended into the emulsion composition is, from the viewpoint of facilitating the formation of a polyion complex, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, still more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, and still more preferably 0.3% by mass or more, based on the total amount of the emulsion composition (100% by mass). Furthermore, from the viewpoint of facilitating the formation of a polyion complex and improving the stability of the emulsion composition obtained via step (2-1) or (2-2), the amount is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, still more preferably 1.5% by mass or less, and still more preferably 1.2% by mass or less. The amount of component (C) blended into the emulsion composition is preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.02% by mass or more and 5.0% by mass or less, even more preferably 0.03% by mass or more and 5.0% by mass or less, still more preferably 0.05% by mass or more and 3.0% by mass or less, even more preferably 0.1% by mass or more and 2.0% by mass or less, still more preferably 0.2% by mass or more and 1.5% by mass or less, and still more preferably 0.3% by mass or more and 1.2% by mass or less, based on the total amount of the emulsion composition (100% by mass). However, when the emulsion composition contains any one of (v) alkyldimethylamines and salts thereof, (vi) alkoxyalkyldimethylamines and salts thereof, and (vii) alkylamidoalkyldimethylamines and salts thereof as component (E), the amount of component (C) in the emulsion composition may be more than 5.0 mass %. This is because the presence of component (C) as a counter anion of the amine is expected to improve the stability of the emulsion composition and the feel upon application to hair when used as a hair cosmetic composition.

[0074] When component (C) is blended in the form of an organic acid salt, the blending amount of component (C) is the amount converted to the organic acid, and the blending amount of component (C) is the total blending amount in step (1) and step (2-1) or (2-2).

[0075] The amount of component (D) blended into the emulsion composition is, from the viewpoints of ease of formation of a polyion complex and of improving the emulsified state, preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, still more preferably 40% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, and still more preferably 80% by mass or more, based on 100% by mass of the total amount of the emulsion composition. Furthermore, from the viewpoints of stability of the resulting emulsion composition and flexibility in blending, the amount is preferably 99% by mass or less, more preferably 95% by mass or less, and still more preferably 90% by mass or less. The amount of component (D) blended into the emulsion composition is preferably 10% by mass or more and 99% by mass or less, more preferably 20% by mass or more and 99% by mass or less, even more preferably 30% by mass or more and 99% by mass or less, still more preferably 40% by mass or more and 95% by mass or less, still more preferably 50% by mass or more and 95% by mass or less, still more preferably 60% by mass or more and 95% by mass or less, still more preferably 70% by mass or more and 95% by mass or less, and still more preferably 80% by mass or more and 90% by mass or less, based on a total amount of 100% by mass of the emulsion composition. The amount of component (D) mentioned above is the total amount in step (1) and step (2-1) or (2-2).

[0076] The amount of component (E): cationic surfactant blended into the emulsion composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on the total amount (100% by mass) of the emulsion composition, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent. Furthermore, from the viewpoint of the stability of the resulting emulsion composition, the amount is preferably 10% by mass or less, more preferably 5.0% by mass or less, and even more preferably 3.5% by mass or less. The amount of component (E) blended into the emulsion composition is preferably 0.1% by mass or more to 10% by mass or less, more preferably 0.2% by mass or more to 5.0% by mass or less, even more preferably 0.5% by mass or more to 5.0% by mass or less, and even more preferably 1.0% by mass or more to 3.5% by mass or less.

[0077] When the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent, the amount of component (F): higher alcohol in the emulsion composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on the total amount (100% by mass) of the emulsion composition, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment. Furthermore, from the viewpoint of the stability of the resulting emulsion composition, the amount is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less. The amount of component (F) in the emulsion composition is preferably 0.1% by mass or more to 15% by mass or less, more preferably 0.2% by mass or more to 12% by mass or less, even more preferably 0.5% by mass or more to 12% by mass or less, and even more preferably 1.0% by mass or more to 10% by mass or less.

[0078] When component (G): an oil is used, the amount of component (G) in the emulsion composition is, from the viewpoint of further improving the feel upon application to hair and the feel of hair after treatment, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on 100% by mass of the total amount of the emulsion composition, when the emulsion composition is used as a hair cosmetic composition, preferably a hair rinse, hair conditioner, hair treatment, or hair styling agent. Furthermore, from the viewpoint of improving the feel upon use of the resulting emulsion composition, the amount is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 8.0% by mass or less. The amount of component (G) in the emulsion composition is preferably 0.1% by mass or more to 20% by mass or less, more preferably 0.2% by mass or more to 10% by mass or less, even more preferably 0.5% by mass or more to 10% by mass or less, and even more preferably 1.0% by mass or more to 8.0% by mass or less.

[0079] Component (H): When an aqueous medium is used, the amount of component (H) in the emulsion composition is, from the viewpoint of dispersing the emulsion-forming components, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, and is preferably 10% by mass or less, more preferably 5.0% by mass or less, and even more preferably 3.0% by mass or less, based on 100% by mass of the total amount of the emulsion composition. The amount of component (H) in the emulsion composition is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 5.0% by mass or less, even more preferably 0.5% by mass or more and 5.0% by mass or less, and even more preferably 1.0% by mass or more and 3.0% by mass or less.

[0080] In addition, the emulsion composition may contain anionic surfactants, nonionic surfactants, amphoteric surfactants, aromatic alcohols, antioxidants, antidandruff agents, vitamins, disinfectants, anti-inflammatory agents, preservatives, chelating agents, moisturizers, pearlizing agents, ceramides, fragrances, plant extracts, ultraviolet absorbers, pH adjusters, etc.

[0081] (pH) In terms of improving the feel of the emulsion composition when applied to hair, the pH of a 5% aqueous solution of the emulsion composition at 25°C is preferably 2.0 or higher, more preferably 3.0 or higher, and is preferably 10.0 or lower, more preferably 7.0 or lower, and even more preferably 5.0 or lower. The pH of a 5% aqueous solution of the emulsified composition at 25°C is a value measured using a pH meter after adding water to the emulsified composition to prepare a 5% aqueous solution.

[0082] The method for producing the emulsion composition of the present invention will be described below.

[0083] <Step (1): Preparation of Mixture A> In step (1), the components (A) to (D) are mixed to prepare a mixture A containing the components (A) to (D). By carrying out step (1), a mixture A containing a polyion complex formed from the components (A) and (B) is obtained. Components (A) to (D), their details, and preferred embodiments are as described above.

[0084] In preparing mixture A, the order in which components (A) to (D) are mixed is not particularly limited, and for example, components (A) to (C) may be added to component (D) simultaneously and mixed. From the viewpoint of facilitating the formation of a polyion complex and of forming a more homogeneous polyion complex in component (D), it is preferable to first add components (A) and (C) to component (D) and mix them, and then add component (B) and mix them. The temperature during mixing of components (A) to (D) in step (1) is not particularly limited, but from the viewpoint of improving the dispersibility of components (A) and (B) and from the viewpoint of facilitating the formation of a polyion complex, it is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, and from the viewpoint of suppressing thermal degradation of the blended components, it is preferably 90°C or lower, more preferably 80°C or lower, even more preferably 70°C or lower, and even more preferably 65°C or lower. The temperature during mixing of components (A) to (D) in step (1) is preferably 40°C or higher and 90°C or lower, more preferably 45°C or higher and 80°C or lower, even more preferably 50°C or higher and 70°C or lower, and even more preferably 50°C or higher and 65°C or lower.

[0085] The mixing time for components (A) to (D) in step (1) is not particularly limited, but from the viewpoint of improving the emulsified state, it is preferably 1 minute or more, more preferably 3 minutes or more, and from the viewpoint of productivity, it is preferably 1 hour or less.

[0086] The mixing of components (A) to (D) in step (1) can be carried out using a known emulsifying machine or stirring device such as a high-pressure emulsifying machine, an ultrasonic emulsifying machine, or a homomixer.

[0087] The mixture A obtained in step (1) may be a transparent solution, but is preferably in the form of a suspension. In the mixture A in the form of a suspension, the polyion complex formed from component (A) and component (B) is not solubilized but is precipitated and uniformly dispersed in the solution. When the mixture A in the form of a suspension is used in step (2-1) or (2-2), the polyion complex remains stable in the resulting emulsion composition. This is thought to further improve the stability of the emulsion composition, the feel upon application to hair, and the effect of inhibiting hair frizz under high humidity conditions.

[0088] In the mixture A prepared in step (1), the preferred blending amounts of each component are in the following ranges.

[0089] The amount of component (A) in mixture A is preferably at least 0.01% by mass, more preferably at least 0.03% by mass, and even more preferably at least 0.05% by mass, based on the total 100% by mass of mixture A, from the viewpoints of ease of polyion complex formation, improved feel upon application of the resulting emulsion composition to hair when used as a hair cosmetic composition, and suppression of hair spread under high-humidity conditions. Furthermore, from the viewpoint of improving the emulsified state, the amount is preferably less than 10% by mass, more preferably less than 5% by mass, even more preferably less than 1% by mass, and even more preferably less than 0.5% by mass. The amount of component (A) in mixture A is preferably at least 0.01% by mass and less than 10% by mass, more preferably at least 0.03% by mass and less than 5% by mass, even more preferably at least 0.03% by mass and less than 1% by mass, and even more preferably at least 0.05% by mass and less than 0.5% by mass, based on the total 100% by mass of mixture A.

[0090] The amount of component (B) in mixture A is preferably at least 0.01% by mass, more preferably at least 0.02% by mass, and even more preferably at least 0.05% by mass, based on the total 100% by mass of mixture A, from the viewpoints of ease of polyion complex formation, improved feel upon application of the resulting emulsion composition to hair when used as a hair cosmetic composition, and suppression of hair spread under high-humidity conditions. Furthermore, from the viewpoint of improving the emulsified state, the amount is preferably less than 5% by mass, more preferably less than 3% by mass, even more preferably less than 1% by mass, and even more preferably less than 0.3% by mass. The amount of component (B) in mixture A is preferably at least 0.01% by mass and less than 5% by mass, more preferably at least 0.01% by mass and less than 3% by mass, even more preferably at least 0.02% by mass and less than 1% by mass, even more preferably at least 0.02% by mass and less than 0.3% by mass, based on the total 100% by mass of mixture A.

[0091] The amount of component (C) in mixture A is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, based on the total amount (100% by mass) of mixture A, from the viewpoint of ease of formation of a polyion complex. Furthermore, from the viewpoint of ease of preparation of mixture A in suspension form, the amount is preferably less than 10% by mass, more preferably less than 6% by mass, even more preferably less than 1% by mass, still more preferably less than 0.75% by mass, and even more preferably less than 0.30% by mass. The amount of component (C) in mixture A is preferably 0.01% by mass or more and less than 10% by mass, more preferably 0.01% by mass or more and less than 6% by mass, even more preferably 0.03% by mass or more and less than 1% by mass, still more preferably 0.05% by mass or more and less than 0.75% by mass, and even more preferably 0.05% by mass or more and less than 0.30% by mass, based on the total amount (100% by mass) of mixture A. The amount of component (C) used in preparing mixture A in step (1) may be a portion of the component (C) contained in the resulting emulsion composition.

[0092] In mixture A, the mass ratio [(A+B) / C] of the total amount of components (A) and (B) to the amount of component (C) is preferably in the range of 1 / 0.10 to 1 / 20, more preferably 1 / 0.15 to 1 / 15, even more preferably 1 / 0.20 to 1 / 10, still more preferably 1 / 0.20 to 1 / 8, and even more preferably 1 / 0.22 to 1 / 4, from the viewpoints of improving the feel when applied to hair when the resulting emulsion composition is used as a hair cosmetic composition, and of suppressing hair frizz under high-humidity conditions.

[0093] The amount of component (D) in mixture A is, from the viewpoint of ease of polyion complex formation and improved emulsification, preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on 100% by mass of the total amount of mixture A. Furthermore, from the viewpoint of stability of the resulting emulsion composition and flexibility of blending, the amount is preferably 99.97% by mass or less, more preferably 99.8% by mass or less. The amount of component (D) in mixture A is, from the viewpoint of 100% by mass of the total amount of mixture A, preferably 50% by mass or more and 99.97% by mass or less, more preferably 50% by mass or more and 99.8% by mass or less, even more preferably 60% by mass or more and 99.8% by mass or less, even more preferably 70% by mass or more and 99.8% by mass or less, and even more preferably 80% by mass or more and 99.8% by mass or less. The amount of component (D) used in preparing mixture A in step (1) may be a portion of the component (D) contained in the resulting emulsion composition.

[0094] Mixture A may contain components other than components (A) to (D). However, from the viewpoints of ease of formation of a polyion complex, improvement of the emulsified state, and stability of the resulting emulsion composition, the total content of components (A) to (D) in mixture A is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more, but 100% by mass or less.

[0095] In step (1), from the viewpoint of dispersing the polyion complex more uniformly in mixture A, the pH of mixture A at 25°C is preferably 1.5 or more, more preferably 2.0 or more, and preferably 4.0 or less, more preferably 3.2 or less, and even more preferably 3.0 or less. The pH of mixture A at 25°C is preferably 1.5 or more and 4.0 or less, more preferably 2.0 or more and 4.0 or less, even more preferably 2.0 or more and 3.2 or less, and even more preferably 2.0 or more and 3.0 or less. The pH of mixture A at 25°C can be measured using a pH meter.

[0096] <Process (2)> The production method of the present invention includes either the following step (2-1) or step (2-2) after step (1), which allows the production of a highly stable emulsion composition containing the polyion complex obtained in step (1). Step (1) A step of preparing a mixture A containing the components (A) to (D) Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing an emulsion-forming component. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing an emulsion-forming component with an aqueous phase component other than the mixture A, and then mixing the mixture A.

[0097] (Process (2-1)) In step (2-1), first, the mixture A obtained in step (1) is mixed with an oil phase component containing an emulsion-forming component to prepare emulsion (I). Next, one or more components selected from the group consisting of an aqueous phase component other than the mixture A and an oil phase component not containing an emulsion-forming component can be mixed as necessary. The mixing ratio of mixture A and the oil phase components containing emulsion-forming components is not particularly limited, as long as they are mixed and adjusted so that the total amount of component (A) and component (B) in the resulting emulsion composition falls within a predetermined range. The "oil phase component containing emulsion-forming components" preferably contains, as emulsion-forming components, component (E): a cationic surfactant and component (F): a higher alcohol, and may further contain component (H) (aqueous medium). From the viewpoint of stably forming an emulsion, the content of the emulsion-forming components in the oil phase component containing emulsion-forming components used in step (2-1) is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more, and 100% by mass or less. Examples of the "aqueous phase components other than mixture A" include the remaining amounts of component (C) (organic acid) and component (D) (water), as well as component (H) (aqueous medium). Examples of "oil phase components not containing emulsion-forming components" include component (G) (oil agent). Hereinafter, the aqueous phase components other than mixture A and the oil phase components not containing emulsion-forming components will also be collectively referred to as "other components."

[0098] The temperature during mixing of mixture A with the oil phase components containing emulsion-forming ingredients in step (2-1) is not particularly limited, but from the viewpoint of the stability of the resulting emulsion composition, it is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, and from the viewpoint of suppressing thermal degradation of the blended ingredients, it is preferably 90°C or lower, more preferably 80°C or lower, and even more preferably 70°C or lower. The temperature during mixing of mixture A with the oil phase components containing emulsion-forming ingredients in step (2-1) is preferably 40°C or higher and 90°C or lower, more preferably 45°C or higher and 80°C or lower, and even more preferably 50°C or higher and 70°C or lower. The mixing time of mixture A and the oil phase components containing emulsion-forming components in step (2-1) is not particularly limited, but is preferably 1 minute or more, more preferably 3 minutes or more, from the viewpoint of improving the emulsified state, and is preferably 1 hour or less, from the viewpoint of productivity.

[0099] Next, if necessary, the resulting emulsion (I) is mixed with aqueous phase components other than mixture A and / or oil phase components not containing emulsion-forming components (other components). The emulsion (I) and the other components may be mixed together all at once, or may be added one to the other in several batches and mixed.

[0100] The temperature during mixing of the emulsion (I) and other components is not particularly limited, but from the viewpoint of improving the application feel when the resulting emulsion composition is used as a hair cosmetic composition and applied to hair, and from the viewpoint of the stability of the resulting emulsion composition, the temperature is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, and from the viewpoint of suppressing thermal degradation of the blended components, the temperature is preferably 90°C or lower, more preferably 80°C or lower. If heating is performed during the preparation of the emulsion (I), it is preferable to mix the emulsion (I) and other components while performing a cooling step. The cooling step can be performed by a known method, for example, air cooling. The mixing time for mixing the emulsion (I) with the other components is not particularly limited, and is preferably 1 minute or more, 5 minutes or more, more preferably 10 minutes or more, and from the viewpoint of productivity, is preferably 12 hours or less, more preferably 5 hours or less, and even more preferably 1 hour or less.

[0101] (Process (2-2)) In step (2-2), first, emulsion (II) is prepared by mixing an oil phase component containing emulsion-forming components with an aqueous phase component other than mixture A. Next, the emulsion is mixed with mixture A. The "oil phase components including emulsion-forming components" and "aqueous phase components other than mixture A" referred to here are the same as those in step (2-1). The aqueous phase component other than the mixture A used in the preparation of the emulsion (II) does not need to be the entire amount of the aqueous phase component used in the step (2-2), but may be at least a portion of the amount. The aqueous phase component other than the mixture A used in the preparation of the emulsion (II) is preferably component (D): water.

[0102] The temperature during mixing of the oil phase components containing the emulsion-forming components with the aqueous phase components other than Mixture A in Step (2-2) is not particularly limited, but is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, from the viewpoints of improving the application feel when the resulting emulsion composition is applied to hair as a hair cosmetic composition and of the stability of the resulting emulsion composition. From the viewpoints of suppressing thermal degradation of the blended components, the temperature is preferably 90°C or lower, more preferably 80°C or lower. The temperature during mixing of the oil phase components containing the emulsion-forming components with the aqueous phase components other than Mixture A in Step (2-2) is preferably 40°C or higher and 90°C or lower, more preferably 45°C or higher and 90°C or lower, and even more preferably 50°C or higher and 80°C or lower. The mixing time during which the oil phase components containing the emulsion-forming components with the aqueous phase components other than Mixture A in Step (2-2) is also not particularly limited, but is preferably 1 minute or longer, more preferably 3 minutes or longer, from the viewpoint of preparing an emulsion, and is preferably 1 hour or shorter, from the viewpoint of productivity.

[0103] Next, the resulting emulsion (II) and mixture A are mixed. The mixing ratio of the mixture A and the emulsion (II) is not particularly limited, as long as they are mixed in such a manner that the total amount of the components (A) and (B) in the resulting emulsion composition falls within a predetermined range. Emulsion (II) and mixture A may be mixed all at once, or may be added one to the other in several batches and mixed. Alternatively, the remaining aqueous phase components other than mixture A, and oil phase components not containing emulsion-forming components (preferably component (G) (oil)), etc. may be added and mixed simultaneously with, or before or after, mixing of emulsion (II) and mixture A.

[0104] The temperature at which emulsion (II) and mixture A are mixed is not particularly limited, but from the viewpoint of the stability of the resulting emulsion composition, it is preferably 50° C. or lower, more preferably 45° C. or lower, and preferably 10° C. or higher, more preferably 20° C. or higher. The temperature at which emulsion (II) and mixture A are mixed is preferably 10° C. or higher and 50° C. or lower, more preferably 20° C. or higher and 45° C. or lower. The mixing time for mixing the emulsion (II) with the mixture A is not particularly limited, and is preferably 1 minute or more, more preferably 3 minutes or more, and from the viewpoint of productivity, is preferably 1 hour or less.

[0105] The mixing steps in step (2-1) and step (2-2) can be carried out using the same equipment as in step (1).

[0106] The production method of the present invention may include step (1) and either step (2-1) or (2-2). From the viewpoint of achieving a better emulsified state, the production method of the present invention preferably includes step (1) and step (2-1). The emulsion composition can be obtained by the production method of the present invention. The emulsion composition has high stability and is used as a cosmetic composition, preferably a hair cosmetic composition. When the emulsion composition is used as a hair cosmetic composition, it provides a good feel when applied to hair and can suppress spreading of the treated hair under high humidity conditions.

[0107] In relation to the above-described embodiments, the present invention further discloses the following. <1> Component (A): one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers; Component (B): anionic polymer, Component (C): organic acid, and Ingredient (D): Water A method for producing an emulsion composition comprising: The production method includes the following step (1) and either step (2-1) or step (2-2): A method for producing an emulsion composition, wherein the total amount of the component (A) and the component (B) in the emulsion composition is less than 1.0 mass % relative to 100 mass % of the total amount of the emulsion composition. Step (1) A step of preparing a mixture A containing the components (A) to (D) Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing an emulsion-forming component. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing an emulsion-forming component with an aqueous phase component other than the mixture A, and then mixing the mixture A. <2> Component (A): one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers; Component (B): anionic polymer, Component (C): organic acid, and Ingredient (D): Water A method for producing an emulsion composition comprising: The production method includes the following step (1) and either step (2-1) or step (2-2): A method for producing an emulsion composition, wherein the total amount of the components (A) and (B) in the emulsion composition is less than 1.0% by mass, based on a total amount (100% by mass) of the emulsion composition, and the ratio of the number of moles of cationic charge of component (A) to the number of moles of anionic charge of component (B) in the emulsion composition is 20 / 80 to 60 / 40. Step (1) A step of preparing a mixture A containing the components (A) to (D), in which the blending amount of component (C) is 0.05 mass% or more and less than 0.30 mass%, and the mass ratio of the blending amount of component (C) to the blending amount of component (A) and component (B) [(A+B) / C] is 1 / 0.2 to 1 / 10. Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing emulsion-forming components including component (E): a cationic surfactant and component (F): a higher alcohol at a temperature of 50°C or higher and 70°C or lower. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing emulsion-forming components including component (E): a cationic surfactant and component (F): a higher alcohol with aqueous phase components other than mixture A, and then mixing mixture A at a temperature of 20°C or higher and 45°C or lower. <3> Component (A): one or more polymers selected from the group consisting of dimethyldiallylammonium chloride polymer (Polyquaternium-6), dimethyldiallylammonium chloride-acrylic acid copolymer (Polyquaternium-22), acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39), and acrylic acid-methyl acrylate-methacrylamidopropyltrimethylammonium chloride copolymer (Polyquaternium-47); Component (B): one or more anionic polymers selected from the group consisting of polyacrylic acid, (acrylic acid / stearyl acrylate) copolymer, or salts thereof; Component (C): organic acid, and Ingredient (D): Water A method for producing an emulsion composition comprising: The production method includes the following step (1) and either step (2-1) or step (2-2): A method for producing an emulsion composition, wherein the total amount of the components (A) and (B) in the emulsion composition is less than 1.0% by mass, based on a total amount (100% by mass) of the emulsion composition, and the ratio of the number of moles of cationic charge of component (A) to the number of moles of anionic charge of component (B) in the emulsion composition is 20 / 80 to 60 / 40. Step (1) A step of preparing a mixture A containing the components (A) to (D), in which the blending amount of component (C) is 0.05 mass% or more and less than 0.30 mass%, and the mass ratio of the blending amount of component (C) to the blending amount of component (A) and component (B) [(A+B) / C] is 1 / 0.2 to 1 / 10. Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing emulsion-forming components including component (E): a cationic surfactant and component (F): a higher alcohol at a temperature of 50°C or higher and 70°C or lower. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing emulsion-forming components including component (E): a cationic surfactant and component (F): a higher alcohol with aqueous phase components other than mixture A, and then mixing mixture A at a temperature of 20°C or higher and 45°C or lower. <4> the cationic polymer is a polymer having cationic groups and substantially having no anionic groups or amphoteric groups; <1> or <2> A method for producing the emulsion composition described above. <5> The cationic polymer is a polymer having cationic groups, and the molar ratio of anionic groups and amphoteric groups to the cationic groups is preferably 0.1% or less. <1> , <2> , <4> 1. A method for producing the emulsion composition according to any one of the preceding claims. <6> The amphoteric polymer is preferably a polymer having a cationic group and an anionic group, a 1% aqueous solution of the polymer having a pH of less than 5.1 at 25°C, and a total positive charge on the polymer. <1> , <2> , <4> , <5> 1. A method for producing the emulsion composition according to any one of the preceding claims. <7> The cationic charge density of the component (A) is preferably 0.1 meq / g or more and 10 meq / g or less, more preferably 0.5 meq / g or more and 8.0 meq / g or less, even more preferably 1.0 meq / g or more and 7.0 meq / g or less, and still more preferably 2.0 meq / g or more and 7.0 meq / g or less. <1> ~ <6> 1. A method for producing the emulsion composition according to any one of the preceding claims. <8> The weight average molecular weight of the component (A) is preferably 5,000 or more and 2,000,000 or less, more preferably 8,000 or more and 1,500,000 or less. <1> ~ <7> 1. A method for producing the emulsion composition according to any one of the preceding claims. <9> The component (A) is preferably at least one selected from the group consisting of cationized guar gum, cationized tara gum, cationized locust bean gum, cationic starch, cationized cellulose, cationized hydroxyalkylcellulose, cationized polyvinyl alcohol, polyethyleneimine, quaternized dialkylaminoalkyl (meth)acrylate polymers, diallyl quaternized ammonium salt polymers, methacrylamidepropyltrimethylammonium salt polymers, methacryloylethyltrimethylammonium salt polymers, vinylimidazolium trichloride-vinylpyrrolidone copolymer (polyquaternium-16), vinylpyrrolidone-alkylamino(meth)acrylate copolymers, vinylpyrrolidone-alkylamino(meth)acrylate-vinylcaprolactam copolymers, alkylacrylamide-(meth)acrylate-alkylaminoalkylacrylamide-polyethylene glycol (meth)acrylate copolymers, and adipic acid-dimethylaminohydroxypropylethylenetriamine copolymers, and more preferably at least one selected from the group consisting of quaternized dialkylaminoalkyl (meth)acrylate polymers, diallyl quaternized ammonium salt polymers, methacrylamidepropyltrimethylammonium salt polymers, methacryloylethyltrimethylammonium salt polymers, vinylimidazolium trichloride-vinylpyrrolidone copolymer (polyquaternium-16), vinylpyrrolidone-alkylamino(meth)acrylate copolymers, vinylpyrrolidone-alkylamino(meth)acrylate-vinylcaprolactam copolymers, alkylacrylamide-(meth)acrylate-alkylaminoalkylacrylamide-polyethylene glycol (meth)acrylate copolymers, and adipic acid-dimethylaminohydroxypropylethylenetriamine copolymers. more preferably, one or more selected from the group consisting of diallyl quaternized ammonium salt polymers, methacrylamide propyl trimethyl ammonium salt polymers, methacryloyl ethyl trimethyl ammonium salt polymers, and vinylimidazolium trichloride-vinylpyrrolidone copolymers (polyquaternium-16); more preferably, one or more selected from the group consisting of diallyl quaternized ammonium salt polymers, methacrylamide propyl trimethyl ammonium salt polymers, and vinylimidazolium trichloride-vinylpyrrolidone copolymers (polyquaternium-16); Preferably, the polymer is at least one selected from the group consisting of dimethyldiallylammonium chloride polymer (Polyquaternium-6), dimethyldiallylammonium chloride-acrylic acid copolymer (Polyquaternium-22), acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39), acrylic acid-methyl acrylate-methacrylamidopropyltrimethylammonium chloride copolymer (Polyquaternium-47), and vinylimidazolium trichloride-vinylpyrrolidone copolymer (Polyquaternium-16), <1> ,<2> , <4> ~ <8> The method for producing the emulsion composition according to any one of the above items. <10> The component (A) is more preferably at least one selected from the group consisting of dimethyldiallylammonium chloride polymer (Polyquaternium-6), acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39), and vinylimidazolium trichloride-vinylpyrrolidone copolymer (Polyquaternium-16). <1> ~ <9> 1. A method for producing the emulsion composition according to any one of the preceding claims.

[0108] <11> The cationic charge density of the dimethyldiallylammonium chloride polymer (polyquaternium-6) is more preferably 2.0 meq / g or more, even more preferably 2.5 meq / g or more, and even more preferably 6.5 meq / g or less, and the weight average molecular weight is more preferably 10,000 or more and 200,000 or less. <3> , <9> , <10> 1. A method for producing the emulsion composition according to any one of the preceding claims. <12> The cationic charge density of the dimethyldiallylammonium chloride-acrylic acid copolymer (Polyquaternium-22) is more preferably 2.0 meq / g or more, more preferably 3.0 meq / g or more, more preferably 4.0 meq / g or more, and more preferably 6.5 meq / g or less, and more preferably 6.0 meq / g or less, and the weight average molecular weight is more preferably 20,000 or more, more preferably 50,000 or more, more preferably 100,000 or more, more preferably 200,000 or more, more preferably 300,000 or more, and more preferably 1 million or less, more preferably 600,000 or less, and more preferably 500,000 or less. <3> or <9> A method for producing the emulsion composition described above. <13> The cationic charge density of the acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39) is more preferably 2.0 meq / g or more, more preferably 2.5 meq / g or more, more preferably 6.5 meq / g or less, more preferably 5.0 meq / g or less, and more preferably 4.0 meq / g or less, and the weight average molecular weight is more preferably 20,000 or more, more preferably 50,000 or more, more preferably 100,000 or more, more preferably 1 million or less, more preferably 600,000 or less, more preferably 500,000 or less, and more preferably 300,000 or less. <3> , <9> , <10> 1. A method for producing the emulsion composition according to any one of the preceding claims. <14> The cationic charge density of the acrylic acid-methyl acrylate-methacrylamidopropyltrimethylammonium chloride copolymer (Polyquaternium-47) is more preferably 2.0 meq / g or more, more preferably 2.5 meq / g or more, more preferably 6.5 meq / g or less, more preferably 5.0 meq / g or less, and more preferably 4.5 meq / g or less, and the weight average molecular weight is more preferably 200,000 or more, more preferably 500,000 or more, and more preferably 1 million or more, and preferably 5 million or less, more preferably 3 million or less, and more preferably 1.5 million or less. <3> or <9> A method for producing the emulsion composition described above. <15> The cationic charge density of the vinylimidazolium trichloride-vinylpyrrolidone copolymer (Polyquaternium-16) is more preferably 2.0 meq / g or more, more preferably 6.5 meq / g or less, more preferably 5.0 meq / g or less, and more preferably 4.5 meq / g or less, and the weight average molecular weight is more preferably 20,000 or more, more preferably 50,000 or more, and more preferably 150,000 or less. <3> , <9> , <10> 1. A method for producing the emulsion composition according to any one of the preceding claims. <16> The component (B) is a polymer having an anionic group and substantially not having a cationic group or an amphoteric group. <1> , <2> , <4> ~ <15> 1. A method for producing the emulsion composition according to any one of the preceding claims. <17> The component (B) is a polymer having anionic groups, and the molar amount of cationic groups and amphoteric groups relative to the anionic groups is preferably 0.1% or less. <1> , <2> , <4> ~ <16> 1. A method for producing the emulsion composition according to any one of the preceding claims. <18> The anionic group contained in the component (B) is preferably one or more acidic groups selected from the group consisting of a carboxy group, a sulfonic acid group, and a phosphate group, more preferably a carboxy group. <1> , <2> , <4> ~ <17> 1. A method for producing the emulsion composition according to any one of the preceding claims. <19> The anionic charge density of the component (B) is preferably 0.1 meq / g or more and 30 meq / g or less, more preferably 0.5 meq / g or more and 30 meq / g or less, even more preferably 1.0 meq / g or more and 20 meq / g or less, and still more preferably 2.0 meq / g or more and 15 meq / g or less. <1> ~ <18> 1. A method for producing the emulsion composition according to any one of the preceding claims. <20> The weight average molecular weight of the component (B) is preferably 3,000 or more and 50,000 or less, more preferably 5,000 or more and 40,000 or less, and even more preferably 10,000 or more and 30,000 or less. <1> ~ <19> 1. A method for producing the emulsion composition according to any one of the preceding claims.

[0109] <21> The component (B) is preferably a polymer having a carboxy group, more preferably a carboxy group-containing cellulose derivative, a carboxyvinyl polymer, poly(meth)acrylic acid, a (meth)acrylic acid-based copolymer, or a salt thereof, even more preferably one or more selected from the group consisting of poly(meth)acrylic acid, a (meth)acrylic acid-based copolymer, or a salt thereof, still more preferably one or more selected from the group consisting of polyacrylic acid, a (meth)acrylic acid / (meth)acrylic acid alkyl ester copolymer, or a salt thereof, and even more preferably one or more selected from the group consisting of polyacrylic acid, an (acrylic acid / stearyl acrylate) copolymer, or a salt thereof. <1> , <2> , <4> ~ <20> 1. A method for producing the emulsion composition according to any one of the preceding claims. <22> The component (C) is preferably a compound having a molecular weight of 500 or less, more preferably 200 or less. <21> 1. A method for producing the emulsion composition according to any one of the preceding claims. <23> The component (C) is at least one selected from the group consisting of carboxylic acid compounds other than the component (B) and sulfonic acid compounds, preferably at least one selected from the group consisting of aliphatic dicarboxylic acids, hydroxycarboxylic acids, and aromatic sulfonic acids, more preferably at least one selected from the group consisting of succinic acid, lactic acid, malic acid, glycolic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid, even more preferably at least one selected from the group consisting of succinic acid and lactic acid, and still more preferably lactic acid. <1> ~ <22> 1. A method for producing the emulsion composition according to any one of the preceding claims. <24> The proportion of the organic acid salt in the component (C) is preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 35% by mass or less, still more preferably 20% by mass or less, still more preferably 10% by mass or less, still more preferably 5% by mass or less, and still more preferably 2% by mass or less. <1> ~ <23> 1. A method for producing the emulsion composition according to any one of the preceding claims. <25> The emulsion composition preferably contains, as emulsion-forming components, a cationic surfactant (component (E)) and a higher alcohol (component (F)). <1> , <4> ~ <24> 1. A method for producing the emulsion composition according to any one of the preceding claims. <26> The component (E) is at least one selected from the group consisting of (i) alkyltrimethylammonium salts, (ii) alkoxyalkyltrimethylammonium salts, (iii) dialkyldimethylammonium salts, (iv) alkylamidoalkyltrimethylammonium salts, (v) alkyldimethylamines and salts thereof, (vi) alkoxyalkyldimethylamines and salts thereof, and (vii) alkylamidoalkyldimethylamines and salts thereof, preferably at least one selected from the group consisting of (i) alkyltrimethylammonium salts, (ii) alkoxyalkyltrimethylammonium salts, (iii) dialkyldimethylammonium salts, (iv) alkylamidoalkyltrimethylammonium salts, (v) alkyldimethylamines and salts thereof, (vi) alkoxyalkyldimethylamines and salts thereof, and (vii) alkylamidoalkyldimethylamines and salts thereof. more preferably, (ii) one or more selected from the group consisting of alkoxyalkyltrimethylammonium and (v) alkyldimethylamine and a salt thereof; even more preferably, one or more selected from the group consisting of stearoxypropyltrimethylammonium chloride, stearoxyethyltrimethylammonium chloride, stearoxyhydroxypropyltrimethylammonium chloride, N,N-dimethyl-3-hexadecyloxypropylamine or a lactate thereof, and N,N-dimethyl-3-octadecyloxypropylamine (stearoxypropyldimethylamine) or a lactate thereof; and even more preferably, one or more selected from the group consisting of stearoxypropyltrimethylammonium chloride and N,N-dimethyl-3-octadecyloxypropylamine (stearoxypropyldimethylamine) or a lactate thereof. <2> , <3> , <25> 1. A method for producing the emulsion composition according to any one of the preceding claims. <27> The component (F) is an aliphatic monohydric alcohol having 12 or more carbon atoms, preferably 12 to 22 carbon atoms, more preferably one or more selected from the group consisting of lauryl alcohol, cetyl alcohol, myristyl alcohol, oleyl alcohol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, behenyl alcohol, and cetostearyl alcohol, even more preferably one or more selected from the group consisting of cetyl alcohol, myristyl alcohol, stearyl alcohol, and behenyl alcohol, and even more preferably stearyl alcohol. <2> , <3> , <25> , <26> 1. A method for producing the emulsion composition according to any one of the preceding claims. <28> The amount of component (A) in the mixture A is preferably 0.01% by mass or more and less than 10% by mass, more preferably 0.03% by mass or more and less than 5% by mass, even more preferably 0.03% by mass or more and less than 1% by mass, and still more preferably 0.05% by mass or more and less than 0.5% by mass, based on 100% by mass of the total amount of the mixture A. <1> ~ <27> 1. A method for producing the emulsion composition according to any one of the preceding claims. <29> The amount of component (B) in the mixture A is, relative to 100% by mass of the total amount of the mixture A, preferably 0.01% by mass or more and less than 5% by mass, more preferably 0.01% by mass or more and less than 3% by mass, even more preferably 0.02% by mass or more and less than 1% by mass, still more preferably 0.02% by mass or more and less than 0.3% by mass, and even more preferably 0.05% by mass or more and less than 0.3% by mass. <1> ~ <28> 1. A method for producing the emulsion composition according to any one of the preceding claims. <30> The amount of component (C) in the mixture A is, relative to 100% by mass of the total amount of mixture A, preferably 0.01% by mass or more and less than 10% by mass, more preferably 0.01% by mass or more and less than 6% by mass, even more preferably 0.03% by mass or more and less than 1% by mass, still more preferably 0.05% by mass or more and less than 0.75% by mass, and even more preferably 0.05% by mass or more and less than 0.30% by mass. <1> , <4> ~ <29> 1. A method for producing the emulsion composition according to any one of the preceding claims.

[0110] <31> In the mixture A, the mass ratio [(A+B) / C] of the total amount of components (A) and (B) to the amount of component (C) is preferably in the range of 1 / 0.10 to 1 / 20, more preferably 1 / 0.15 to 1 / 15, even more preferably 1 / 0.20 to 1 / 10, still more preferably 1 / 0.20 to 1 / 8, and still more preferably 1 / 0.22 to 1 / 4. <1> , <4> ~ <30> 1. A method for producing the emulsion composition according to any one of the preceding claims. <32> The amount of component (D) in the mixture A is preferably 50% by mass or more and 99.97% by mass or less, more preferably 50% by mass or more and 99.8% by mass or less, even more preferably 60% by mass or more and 99.8% by mass or less, still more preferably 70% by mass or more and 99.8% by mass or less, and even more preferably 80% by mass or more and 99.8% by mass or less, based on 100% by mass of the total amount of the mixture A. <1> ~ <31> 1. A method for producing the emulsion composition according to any one of the preceding claims. <33> the total content of components (A) to (D) in the mixture A is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more, and 100% by mass or less; <1> ~ <32> 1. A method for producing the emulsion composition according to any one of the preceding claims. <34> The amount of component (A) blended in the emulsion composition is preferably 0.01% by mass or more and less than 0.50% by mass, more preferably 0.02% by mass or more and 0.30% by mass or less, and even more preferably 0.03% by mass or more and 0.20% by mass or less, based on 100% by mass of the total amount of the emulsion composition. <1> ~ <33> 1. A method for producing the emulsion composition according to any one of the preceding claims. <35> The amount of component (B) blended in the emulsion composition is preferably 0.010% by mass or more and less than 0.50% by mass, more preferably 0.010% by mass or more and 0.30% by mass or less, even more preferably 0.015% by mass or more and 0.20% by mass or less, still more preferably 0.015% by mass or more and 0.15% by mass or less, and still more preferably 0.015% by mass or more and 0.10% by mass or less, based on 100% by mass of the total amount of the emulsion composition. <1> ~ <34> 1. A method for producing the emulsion composition according to any one of the preceding claims. <36> The total amount of component (A) and component (B) in the emulsion composition is less than 1.0% by mass, preferably 0.01% by mass or more and 0.9% by mass or less, more preferably 0.03% by mass or more and 0.9% by mass or less, even more preferably 0.05% by mass or more and 0.9% by mass or less, still more preferably 0.05% by mass or more and 0.5% by mass or less, and still more preferably 0.05% by mass or more and 0.3% by mass or less, based on 100% by mass of the total amount of the emulsion composition. <1> ~ <35> 1. A method for producing the emulsion composition according to any one of the preceding claims. <37> the ratio of the number of moles of cationic charge of component (A) to the number of moles of anionic charge of component (B) in the emulsion composition is preferably 5 / 95 to 95 / 5, more preferably 10 / 90 to 90 / 10, even more preferably 20 / 80 to 80 / 20, still more preferably 20 / 80 to 60 / 40, and still more preferably 40 / 60 to 60 / 40; <1> , <4> ~ <35> 1. A method for producing the emulsion composition according to any one of the preceding claims. <38> The amount of component (C) blended in the emulsion composition is preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.02% by mass or more and 5.0% by mass or less, even more preferably 0.03% by mass or more and 5.0% by mass or less, still more preferably 0.05% by mass or more and 3.0% by mass or less, still more preferably 0.1% by mass or more and 2.0% by mass or less, still more preferably 0.2% by mass or more and 1.5% by mass or less, and still more preferably 0.3% by mass or more and 1.2% by mass or less, based on 100% by mass of the total amount of the emulsion composition. <1> ~ <37> 1. A method for producing the emulsion composition according to any one of the preceding claims. <39> The amount of component (D) blended in the emulsion composition is preferably 10% by mass or more and 99% by mass or less, more preferably 20% by mass or more and 99% by mass or less, even more preferably 30% by mass or more and 99% by mass or less, still more preferably 40% by mass or more and 95% by mass or less, still more preferably 50% by mass or more and 95% by mass or less, still more preferably 60% by mass or more and 95% by mass or less, still more preferably 70% by mass or more and 95% by mass or less, and still more preferably 80% by mass or more and 90% by mass or less, based on 100% by mass of the total amount of the emulsion composition. <1> ~ <38> 1. A method for producing the emulsion composition according to any one of the preceding claims. <40> The amount of component (E) blended in the emulsion composition is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 5.0% by mass or less, even more preferably 0.5% by mass or more and 5.0% by mass or less, and still more preferably 1.0% by mass or more and 3.5% by mass or less. <2> , <3> , <25> ~ <39> 1. A method for producing the emulsion composition according to any one of the preceding claims.

[0111] <41> The amount of component (F) blended in the emulsion composition is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.2% by mass or more and 12% by mass or less, even more preferably 0.5% by mass or more and 12% by mass or less, and still more preferably 1.0% by mass or more and 10% by mass or less. <2> , <3> , <25> ~ <40> 1. A method for producing the emulsion composition according to any one of the preceding claims. <42> The emulsion composition further contains component (G): an oil. <1> ~ <41> 1. A method for producing the emulsion composition according to any one of the preceding claims. <43> The component (G) is at least one selected from the group consisting of (a) silicone oil, (b) ester oil, (c) ether oil, (d) hydrocarbon oil, (e) higher fatty acid, and (f) wax, preferably at least one selected from the group consisting of (a) silicone oil, (b) ester oil, (d) hydrocarbon oil, and (e) higher fatty acid, more preferably at least one selected from the group consisting of (a) silicone oil and (e) higher fatty acid, even more preferably at least one selected from the group consisting of dimethylpolysiloxane, dimethiconol, methylphenylpolysiloxane, modified silicone, and fatty acid having 12 or more carbon atoms, and even more preferably at least one selected from the group consisting of dimethylpolysiloxane, dimethiconol, methylphenylpolysiloxane, modified silicone, and fatty acid having 12 or more carbon atoms, more preferably, the surfactant contains one or more selected from the group consisting of dimethylpolysiloxane, amino-modified silicone, aminopolyether-modified silicone, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, coconut oil fatty acid, lanolin fatty acid, isostearyl acid, and isopalmitic acid, and even more preferably, the surfactant contains one or more selected from the group consisting of dimethylpolysiloxane, amino-modified silicone, aminopolyether-modified silicone, and lanolin fatty acid, and even more preferably, the surfactant contains dimethylpolysiloxane, amino-modified silicone, and lanolin fatty acid, <42> A method for producing the emulsion composition described above. <44> The amount of component (G) blended in the emulsion composition is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.2% by mass or more and 10% by mass or less, even more preferably 0.5% by mass or more and 10% by mass or less, and still more preferably 1.0% by mass or more and 8.0% by mass or less. <42> or <43> A method for producing the emulsion composition described above. <45> The emulsion composition is further blended with component (H): an aqueous medium. <1> ~ <44> 1. A method for producing the emulsion composition according to any one of the preceding claims. <46> The component (H) is at least one selected from the group consisting of lower alcohols, and low-molecular-weight diols and triols having 6 or less carbon atoms, preferably at least one selected from the group consisting of ethanol, isopropyl alcohol, 1,3-butylene glycol, glycerin, ethylene glycol, propylene glycol, and dipropylene glycol. <45> A method for producing the emulsion composition described above. <47> The amount of component (H) blended in the emulsion composition is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 5.0% by mass or less, even more preferably 0.5% by mass or more and 5.0% by mass or less, and still more preferably 1.0% by mass or more and 3.0% by mass or less. <45> or <46> A method for producing the emulsion composition described above. <48> The pH of a 5% aqueous solution of the emulsion composition at 25°C is preferably 2.0 or higher, more preferably 3.0 or higher, and is preferably 10.0 or lower, more preferably 7.0 or lower, and even more preferably 5.0 or lower. <1> ~ <47> 1. A method for producing the emulsion composition according to any one of the preceding claims. <49> The temperature during mixing of the components (A) to (D) in the step (1) is preferably 40°C or higher and 90°C or lower, more preferably 45°C or higher and 80°C or lower, even more preferably 50°C or higher and 70°C or lower, and still more preferably 50°C or higher and 65°C or lower. <1> ~ <48> 1. A method for producing the emulsion composition according to any one of the preceding claims. <50> The mixing time of the components (A) to (D) in the step (1) is preferably 1 minute or more, more preferably 3 minutes or more, and preferably 1 hour or less. <1> ~ <49> 1. A method for producing the emulsion composition according to any one of the preceding claims.

[0112] <51> In the step (1), the components (A) and (C) are added to the component (D) and mixed, and then the component (B) is added and mixed. <1> ~ <50> 1. A method for producing the emulsion composition according to any one of the preceding claims. <52> The mixture A obtained in the step (1) is in the form of a suspension. <1> ~ <51> 1. A method for producing the emulsion composition according to any one of the preceding claims. <53> The pH of the mixture A obtained in the step (1) at 25°C is preferably 1.5 or more and 4.0 or less, more preferably 2.0 or more and 4.0 or less, even more preferably 2.0 or more and 3.2 or less, and still more preferably 2.0 or more and 3.0 or less. <1> ~ <52> 1. A method for producing the emulsion composition according to any one of the preceding claims. <54> In the step (2-1), the temperature during mixing of the mixture A with the oil phase component containing the emulsion-forming component is preferably 40°C or higher and 90°C or lower, more preferably 45°C or higher and 80°C or lower, and even more preferably 50°C or higher and 70°C or lower. <1> , <4> ~ <53> 1. A method for producing the emulsion composition according to any one of the preceding claims. <55> In the step (2-1), the mixing time of the mixture A and the oil phase component containing the emulsion-forming component is preferably 1 minute or more, more preferably 3 minutes or more, and preferably 1 hour or less. <1> ~ <54> 1. A method for producing the emulsion composition according to any one of the preceding claims. <56> In the step (2-2), the temperature during mixing of the oil phase component containing the emulsion-forming component with the aqueous phase component other than mixture A is preferably 40°C or higher and 90°C or lower, more preferably 45°C or higher and 90°C or lower, and even more preferably 50°C or higher and 80°C or lower. <1> ~ <55> 1. A method for producing the emulsion composition according to any one of the preceding claims. <57> In the step (2-2), the mixing time of the oil phase component containing the emulsion-forming component and the aqueous phase component other than the mixture A is preferably 1 minute or more, more preferably 3 minutes or more, and preferably 1 hour or less. <1> ~ <56> 1. A method for producing the emulsion composition according to any one of the preceding claims. <58> In the step (2-2), the temperature during mixing of the emulsion (II) and the mixture A is preferably 10°C or higher and 50°C or lower, more preferably 20°C or higher and 45°C or lower. <1> , <4> ~ <57> 1. A method for producing the emulsion composition according to any one of the preceding claims. <59> In the step (2-2), the mixing time of the emulsion (II) and the mixture A is preferably 1 minute or more, more preferably 3 minutes or more, and from the viewpoint of productivity, is preferably 1 hour or less. <1> ~ <58> 1. A method for producing the emulsion composition according to any one of the preceding claims. <60> The method includes steps (1) and (2-1). <1> ~ <59> 1. A method for producing the emulsion composition according to any one of the preceding claims. <61> <1> ~ <60> A method for improving the stability of an emulsion composition, comprising the method for producing an emulsion composition according to any one of the above items. <62> <1> ~ <60> A method for suppressing frizziness of hair under high humidity conditions, comprising the step of applying the emulsion composition according to any one of the above to hair. <63> Component (A): one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers, and A method for improving the stability of an emulsion composition containing component (B): an anionic polymer, comprising: The method includes the following step (1) and either step (2-1) or step (2-2): The method, wherein the total amount of the component (A) and the component (B) in the emulsion composition is less than 1.0% by mass, relative to 100% by mass of the total amount of the emulsion composition. Step (1) A step of preparing a mixture A containing the component (A), the component (B), the component (C): an organic acid, and the component (D): water. Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing an emulsion-forming component. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing an emulsion-forming component with an aqueous phase component other than the mixture A, and then mixing the mixture A. [Example]

[0113] The present invention will be described below with reference to examples, but the present invention is not limited to the scope of the examples. Measurements and evaluations in the examples were carried out by the following methods.

[0114] (pH measurement) For each emulsified composition (hair conditioner), water was added to the emulsified composition to prepare a 5% aqueous solution, and the pH of the 5% aqueous solution at 25°C was measured using a pH meter (F-51, manufactured by Horiba, Ltd.) The pH was 3.4 in all cases. The pH of mixture A or A' at 25°C was measured using the pH meter. The mixture prepared in step (1) that does not fall under the category of "mixture A" defined in the present invention is referred to as "mixture A'."

[0115] (emulsified state) 1 g of each hair conditioner was dropped onto a black plastic underlay, and the appearance and feel of the hair when rubbed with a finger 10 times were evaluated according to the following criteria. A: No agglomerated particles are visible, and the surface feels smooth when you run your finger over it. B: No visible agglomerated particles, but they feel rough when rubbed with a finger C: Agglomerated particles are visible and feel rough when rubbed with a finger D: Separated

[0116] (Storage stability) The storage stability of each hair conditioner was evaluated by a cycle test. A cycle test was carried out in which each hair conditioner was stored for two weeks in an environment where the temperature changed between 40°C and -28°C. The daily temperature cycle was set to four cycles per day with a temperature difference ΔT of 40°C. After storage, the hair conditioner was visually observed for the presence or absence of separation, and in the table, those that were stable and did not separate were marked with an "A", and those that separated were marked with a "D".

[0117] (Feel when applied) A bleaching agent (a mixture of 7 mL of Kao Foam Hair Bleach L (1st liquid) and 14 mL of Kao Foam Hair Color d (2nd liquid)) was applied to a 30 cm long, 20 g mass Japanese hair tress, left to stand for 20 minutes, and then rinsed thoroughly with warm water at 35-40°C. The above process was repeated four times to prepare a Japanese damaged hair tress for evaluation. 1 mL of each hair conditioner was applied to the evaluation tresses and rubbed in with the hands. Five expert panelists evaluated the feel of the conditioner on a 5-point scale according to the following criteria, and the average value was used as the evaluation result. 5: Very smooth 4: Smooth 3: Somewhat smooth 2: Smoothness is equivalent to that of using plain conditioner with the following composition 1: It quickly loses presence and is not smooth

[0118] [Plain conditioner composition] (quality%) Stearoxypropyldimethylamine (*1) 0.9 Stearyl alcohol (*2) 3.0 Dipropylene glycol 0.5 Benzyl alcohol 0.2 Lactic acid(*3) 1.1 Refined water residue Total 100.0 (*1) Kao Corporation's "Farmin DM-E80," active ingredient content 90% by mass (*2) Kao Corporation's "Kalcol 8098," active ingredient content 100% by mass (*3) PURAC Thailand Ltd. "PURAC ULTRAPURE90", active ingredient content 90% by mass

[0119] (Hair resistance to humidity after treatment) 1 mL of each hair conditioner was applied to the evaluation tresses of damaged Japanese hair prepared by the above method and allowed to soak in for 30 seconds. After leaving it in this state for 1 minute, it was rinsed with running water for 30 seconds and dried completely with a hair dryer. After drying, the tresses were straightened 10 times using a flat iron ("AHI-938" manufactured by Miki Electric Industrial Co., Ltd.) set to 160°C while passing the comb through, and a photograph of the tresses was taken immediately after setting. Next, the straightened hair was hung and left to stand in a high humidity environment of 35°C and 80% RH for 30 minutes, and then photographed again. In the two photographs, the tress width was measured at a point 23.5 cm from the root of the tresses, and the change in the tress width immediately after straightening and after storage in high humidity was calculated using the following formula. Change in trace width = (trace width after storage under high humidity) / (trace width immediately after straightening) If the value exceeds 1.3, the film appears to have spread visually, and therefore the film is judged to have low moisture resistance.

[0120] Example 1 (Production of Hair Conditioner) <Process (1)> Mixture A was prepared using the ingredients listed in Table 1 according to the following procedure. In a 500 mL beaker, 1.52 g of polyquaternium-6 solution (component (A)), 1 g of lactic acid (90% by mass) (component (C)), and 318 g of water (equivalent to 63.59% by mass) (component (D)) were placed, and the mixture was heated and stirred at 56° C. using a stirring device (mechanical stirrer equipped with two propeller blades). After confirming that the solution had become homogeneous, 0.37 g of sodium polyacrylate (component (B)) was added and mixed to obtain mixture A, which was a homogeneous suspension. <Process (2-1)> Next, an emulsion composition (hair conditioner) was prepared according to the following procedure. First, 22.22 g of stearoxypropyltrimethylammonium chloride (component (E)), 10.19 g of stearyl alcohol (component (F)), and 10.0 g of dipropylene glycol, as listed in Table 1, were mixed in advance and heated and dissolved at 85°C to prepare an oil phase component containing emulsion-forming components. This was added to mixture A, and the mixture was heated and stirred at 56°C for 10 minutes. After stirring for 10 minutes, heating was stopped and air cooling was initiated (preparation of emulsion (I)). Next, component (G) (amodimethicone 1.0 g and dimethicone 10.0 g) shown in Table 1 was added and mixed. Furthermore, 120 g of 30°C water (corresponding to 24.00% by mass), 5 g of lanolin fatty acid, and 0.75 g of lactic acid (90% by mass) were added, and the mixture was cooled with stirring until the liquid temperature reached 40°C or below, yielding 500 mL of hair conditioner. The obtained hair conditioners were evaluated using the above-mentioned methods. The results are shown in Table 1. The blending amounts shown in the tables of this example are the blending amounts (mass%) of each component in its natural form, and the "active ingredient concentration" shown in the tables of this example is the content or blending amount (mass%) of each component converted into the amount of active ingredient.

[0121] Examples 2 to 3, 5 to 9, 11 to 16, Comparative Examples 2 to 6 Hair conditioners were produced and evaluated in the same manner as in Example 1, except that the types and amounts of the components used in steps (1) and (2-1) were changed as shown in Tables 1 to 3. The results are shown in Tables 1 to 3.

[0122] Example 4 <Process (1)> Mixture A was prepared using the ingredients listed in Table 1 according to the following procedure. In a 100 mL beaker, 1.52 g of polyquaternium-6 solution (component (A)), 1 g of lactic acid (90% by mass) (component (C)), and 15 g of water (equivalent to 3.00% by mass) (component (D)) were placed, and the mixture was heated and stirred at 56° C. using a stirring device (mechanical stirrer equipped with two propeller blades). After confirming that the solution had become homogeneous, 0.37 g of sodium polyacrylate (component (B)) was added and mixed to obtain mixture A, which was a homogeneous suspension. <Process (2-2)> Next, an emulsion composition (hair conditioner) was prepared according to the following procedure. First, 22.22 g of stearoxypropyltrimethylammonium chloride (component (E)), 10.19 g of stearyl alcohol (component (F)), and 10.0 g of dipropylene glycol, as listed in Table 1, were mixed in advance and dissolved by heating at 85°C to prepare an oil phase component containing emulsion-forming components. 303 g of water (corresponding to 60.59% by mass) was placed in a 500 mL beaker, and heated and stirred at 56°C using a stirring device (a mechanical stirrer equipped with two propeller blades). The oil phase components were added thereto, and heated and stirred at 56°C for 10 minutes. After stirring for 10 minutes, heating was stopped and air cooling was initiated (preparation of emulsion (II)). After air cooling, mixture A was added, and the mixture was stirred for 10 minutes (mixing of emulsion (II) and mixture A). Next, component (G) (1.0 g of amodimethicone and 10.0 g of dimethicone) shown in Table 1 was added and mixed, followed by the addition of 120 g of water at 30°C (corresponding to 24.00 mass%), 5.0 g of lanolin fatty acid, and 0.75 g of lactic acid (90 mass%), and the mixture was cooled with stirring until the liquid temperature reached 40°C or below, yielding 500 mL of a hair conditioner. The obtained hair conditioner was evaluated according to the above-mentioned method, and the results are shown in Table 1.

[0123] Example 10 <Process (1)> Mixture A was prepared using the ingredients listed in Table 2 according to the following procedure. In a 500 mL beaker, 1.52 g of polyquaternium-6 solution (component (A)), 1 g of lactic acid (90% by mass) (component (C)), and 438 g of water (equivalent to 87.59% by mass) (component (D)) were placed, and the mixture was heated and stirred at 75° C. using a stirring device (mechanical stirrer equipped with two propeller blades). After confirming that the solution had become homogeneous, 0.37 g of sodium polyacrylate (component (B)) was added and mixed to obtain mixture A, which was a homogeneous suspension. <Process (2-1)> Next, an emulsion composition (hair conditioner) was prepared according to the following procedure. First, 22.22 g of stearoxypropyltrimethylammonium chloride (component (E)), 10.19 g of stearyl alcohol (component (F)), and 10.0 g of dipropylene glycol, as listed in Table 2, were mixed in advance and heated and dissolved at 85°C to prepare an oil phase component containing emulsion-forming components. This was added to the mixture A, and the mixture was heated and stirred at 75°C for 10 minutes. After stirring for 10 minutes, heating was stopped and air cooling was initiated (preparation of emulsion (I)). Next, component (G) (amodimethicone 1.0 g, dimethicone 10.0 g, lanolin fatty acid 5 g) shown in Table 2 was added, and then 0.75 g of lactic acid (90% by mass) was added. The mixture was cooled with stirring until the liquid temperature reached 40°C or below, yielding 500 mL of a hair conditioner. The obtained hair conditioner was evaluated according to the above-mentioned method, and the results are shown in Table 2.

[0124] Example 17 <Process (1)> Mixture A was prepared using the ingredients listed in Table 2 according to the following procedure. In a 500 mL beaker, 1.52 g of polyquaternium-6 solution (component (A)), 3 g of lactic acid (90% by mass) (component (C)), and 422.71 g (equivalent to 84.54% by mass) of water (component (D)) were placed, and the mixture was heated and stirred at 80° C. using a stirring device (mechanical stirrer equipped with two propeller blades). After confirming that the solution had become homogeneous, 0.37 g of sodium polyacrylate (component (B)) was added and mixed to obtain mixture A, which was a homogeneous suspension. <Process (2-1)> Next, an emulsion composition (hair conditioner) was prepared according to the following procedure. First, 11.00 g of stearoxypropyldimethylamine (component (E)), 31.90 g of stearyl alcohol (component (F)), and 10.0 g of dipropylene glycol, as listed in Table 2, were mixed in advance and dissolved by heating at 75°C to prepare an oil phase component containing emulsion-forming components. This was added to the mixture A, and the mixture was heated and stirred at 75°C for 10 minutes. After stirring for 10 minutes, heating was stopped and air cooling was initiated (preparation of emulsion (I)). Next, component (G) (amodimethicone 1.0 g and dimethicone 10.0 g) shown in Table 2 was added and mixed. Furthermore, 5.0 g of lanolin fatty acid and 3.5 g of lactic acid (90% by mass) were added, and the mixture was cooled with stirring until the liquid temperature reached 40° C. or less, to obtain 500 mL of a hair conditioner. The obtained hair conditioner was evaluated according to the above-mentioned method, and the results are shown in Table 2.

[0125] Comparative Example 1 22.22 g of stearoxypropyldimethylammonium chloride (component (E)), 10.19 g of stearyl alcohol (component (F)), and 10.0 g of dipropylene glycol, as shown in Table 3, were mixed in advance and dissolved by heating at 75°C to prepare an oil phase component containing emulsion-forming components. In a 500 mL beaker, 1.52 g of polyquaternium-6 solution (component (A)), 1 g of lactic acid (90% by mass) (component (C)), and 318 g of water (equivalent to 63.59% by mass) (component (D)) were added, and the mixture was heated and stirred at 56 ° C using a stirring device (mechanical stirrer equipped with two propeller blades) (preparation of mixture A'). After confirming that the solution had become homogeneous, the oil phase components were added, and the mixture was heated and stirred at 56 ° C for 10 minutes (mixing of mixture A' with oil phase components containing emulsion-forming components). After 10 minutes of stirring, heating was stopped and air cooling was initiated. 0.37 g of sodium polyacrylate (component (B)) was added, mixed, and stirred for 10 minutes. Next, component (G) (1.0 g of amodimethicone and 10.0 g of dimethicone) shown in Table 3 was added and mixed, followed by the addition of 120 g of 30°C water (corresponding to 24.00% by mass), 5 g of lanolin fatty acid, and 0.75 g of lactic acid (90% by mass), and the mixture was cooled with stirring until the liquid temperature reached 40°C or below, yielding 500 mL of a hair conditioner. The obtained hair conditioner was evaluated according to the above-mentioned method, and the results are shown in Table 3.

[0126] [Table 1]

[0127] [Table 2]

[0128] [Table 3]

[0129] *: In Comparative Examples 5 and 6, the conditioner was separated and therefore not evaluated. The ingredients listed in the table are as follows: <Component (A): Cationic Polymer or Amphoteric Polymer> *1 Polyquaternium-6 (dimethyldiallylammonium chloride polymer), "MERQUAT 100" manufactured by Lubrizol Advanced Materials, Inc., cationic charge density: 6.18 meq / g, Mw: 150,000, active ingredient content: 41.5% by mass *2 Polyquaternium-39 (acrylamide-acrylic acid-dimethyldiallylammonium chloride copolymer liquid), "MERQUAT 3940 POLYMER" manufactured by Lubrizol Advanced Materials, Inc., cationic charge density: 2.97 meq / g, Mw: 150,000, active ingredient content: 43% by mass *3 Polyquaternium-16 (vinylimidazolium trichloride-vinylpyrrolidone copolymer), BASF SE "Rubycut FC 550", cationic charge density: 3.91 meq / g, Mw: 80,000, active ingredient content: 43% by mass *4 Polyquaternium-22 (dimethyldiallylammonium chloride-acrylic acid copolymer liquid), "MERQUAT 280" manufactured by Lubrizol Advanced Materials, Inc., cationic charge density: 4.99 meq / g, Mw: 450,000, active ingredient content: 41% by mass *5 Polyquaternium-47 (acrylic acid, methyl acrylate, and methacrylamide propyl trimethylammonium chloride copolymer), "MERQUAT 2001 POLYMER" manufactured by Lubrizol Advanced Materials, Inc., cationic charge density: 3.21 meq / g, Mw: 1.3 million, active ingredient content: 21% by mass

[0130] <Component (B): Anionic polymer> *6 Sodium polyacrylate, "Acusol 445G Polymer" manufactured by The Dow Chemical Company, anionic charge density: 10.6 meq / g, Mw: 25,000, active ingredient content: 100% by mass *7 (Acrylic acid / stearyl acrylate) copolymer, Kao Corporation "SOFCARE SA-37W", anionic charge density: 9.3 meq / g, Mw: 20,000, active ingredient content: 10% by mass <Component (C): Organic acid> *8 Lactic acid, PURAC Thailand Ltd. "PURAC ULTRAPURE90", active ingredient content: 90% by mass <Component (E): Cationic surfactant> *9 Stearoxypropyltrimethylammonium chloride, Kao Corporation's "Cotamine E-80K", active ingredient content: 45% by mass *10 Stearoxypropyldimethylamine, Kao Corporation's "Farmin DM-E80", active ingredient content: 90% by mass, stearyl alcohol 10% by mass mixture <Component (F): Higher alcohol> *11 Stearyl alcohol, Kao Corporation "Kalcol 8098", active ingredient amount: 100% by mass <Component (H): Aqueous medium> *12 Dipropylene glycol, ADEKA Corporation "DPG-RF", active ingredient amount: 100% by mass <Component (G): Oil> *13 Dimethicone, "Silicone KHS-3" manufactured by Shin-Etsu Chemical Co., Ltd., active ingredient amount: 100% by mass *14 Amodimethicone, Dow Toray Industries, Inc. "Silicone SF 8457 C", active ingredient amount: 100% by mass *15 Lanolin fatty acid, Kao Corporation "18MEA-CL1", active ingredient content: 3.5% by mass [Industrial Applicability]

[0131] According to the present invention, it is possible to provide a method for producing an emulsion composition that contains a polyion complex, is highly stable, and when used as a hair cosmetic composition, improves the feel when applied to hair and can suppress hair frizz under high humidity conditions.

Claims

1. Component (A): one or more polymers selected from the group consisting of cationic polymers and amphoteric polymers; Component (B): anionic polymer, Component (C): organic acid, Component (D): water Component (E): a cationic surfactant, and Component (F): Higher alcohol A method for producing an emulsion composition comprising: The production method includes the following step (1) and either step (2-1) or step (2-2): a total amount of the component (A) and the component (B) in the emulsion composition being less than 1.0 mass% relative to a total amount (100 mass%) of the emulsion composition; Step (1): A step of preparing a mixture A containing the components (A) to (D). Step (2-1): A step of preparing emulsion (I) by mixing the mixture A with an oil phase component containing an emulsion-forming component. Step (2-2) A step of preparing emulsion (II) by mixing an oil phase component containing an emulsion-forming component with an aqueous phase component other than the mixture A, and then mixing the mixture A.

2. 2. The method for producing an emulsion composition according to claim 1, wherein the component (C) is at least one selected from the group consisting of succinic acid, lactic acid, malic acid, glycolic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid.

3. 3. The method for producing an emulsion composition according to claim 1 or 2, wherein in the mixture A, a mass ratio [(A+B) / C] of the total amount of the components (A) and (B) to the amount of the component (C) is in the range of 1 / 0.10 to 1 / 20.

4. The method for producing an emulsion composition according to claim 1 or 2, wherein the mixture A is in the form of a suspension.

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