Process for the preparation of multiple emulsions

Abstract

To provide a technique capable of producing a stable multiple emulsion even when a component having a high melting point is used for producing an inner emulsion.SOLUTION: A method for producing a multiple emulsion, comprising a primary emulsification step of forming a primary emulsion using a component having a melting point of 40 °C or higher under a temperature condition equal to or higher than the melting point of the component, and a secondary emulsification step of forming a multiple emulsion by adding the primary emulsion to a composition containing a continuous phase that becomes an outer phase of the primary emulsion, wherein the temperature of the primary emulsion is not changed by 10 °C or more between the end of the primary emulsification step and the time of addition in the secondary emulsification step.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] An emulsion is a dispersion structure in which insoluble components act as a dispersoid and a dispersion medium (continuous phase). Basic emulsions include two-phase structures such as O / W (oil-in-water) and W / O (water-in-oil). Multiple emulsions are emulsions in which the O / W or W / O phase acts as a dispersoid, such as W / O / W (water-in-oil-in-water) and O / W / O (oil-in-water-in-oil). Furthermore, there are also emulsions in which multiple types of dispersoids are dispersed in a continuous phase, such as (W / O+O) / W and (O / W+W) / O. Multiple emulsions have properties different from emulsions with simple two-phase structures and can impart functionality to compositions, making them important in various industrial applications such as cosmetics, food, pharmaceuticals, etc. For example, it has been disclosed that they have the advantage of improving the stratum corneum permeability of drugs contained in the composition (Patent Document 1).

[0003] A two-stage emulsification method is known as a method for producing multiple emulsions. For example, in the case of a W / O / W type, a W / O type is first prepared in the first stage (primary emulsification), and then, in the second stage, this is dispersed in an aqueous phase to prepare a secondary emulsification (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-089731 [Patent Document 2] Japanese Patent Application Publication No. 11-33391 Summary of the Invention [Problem to be solved by the invention]

[0005] When manufacturing multiple emulsions using the two-stage emulsification method at a factory production scale of 10–3000 kg, the inner emulsion (primary emulsion) is typically temporarily stored before being sent to the next process (Figure 1). During this storage period, the temperature of the primary emulsion drops over time, causing it to harden and become more viscous, or high-melting-point components to recrystallize, potentially hindering the subsequent formation of the emulsion. Furthermore, if a hardened or viscous primary emulsion is reheated before being sent to the next process in an attempt to reduce its viscosity, the emulsion particles tend to increase in size, causing the innermost phase to coalesce with the outer continuous phase, lowering the viscosity and destabilizing the emulsion system, potentially compromising the texture, uniformity, and stability of the composition. Therefore, there are limitations on the ingredients that can be used to manufacture the primary emulsion of multiple emulsions; specifically, it has been difficult to use ingredients with high melting points. In this situation, an object of the present invention is to provide a technique that can produce stable multiple emulsions even when a component with a high melting point is used to produce the inner emulsion. [Means for solving the problem]

[0006] As a result of intensive research by the inventors to solve the above-mentioned problems, they have come up with the idea that when a component with a melting point of 40°C or higher is blended into the inner emulsion, an increase in viscosity of the primary emulsion due to a decrease in temperature can be suppressed by successively carrying out a primary emulsification step in which a primary emulsion is formed at a temperature above the melting point of the component, and a secondary emulsification step in which the primary emulsion is added to a composition containing a continuous phase that will become the outer phase to form a multiple emulsion, thereby completing the present invention.

[0007] That is, the present invention is as follows. [1] a primary emulsification step of forming a primary emulsion using a component having a melting point of 40°C or higher under a temperature condition equal to or higher than the melting point of the component; a secondary emulsification step of adding the primary emulsion to a composition containing a continuous phase that will become an outer phase to form a multiple emulsion, A production method characterized in that the temperature of the primary emulsion is not changed by 10°C or more between the end of the primary emulsification step and the time of addition in the secondary emulsification step. [2] The method according to [1], characterized in that the addition in the secondary emulsification step is carried out within 2 hours from the end of the primary emulsification step. [3] The component having a melting point of 40°C or higher is sucrose fatty acid ester, tri(caprylic acid / caprylic acid) The manufacturing method according to [1] or [2], wherein the hydroxystearic acid is one or more selected from the group consisting of glyceryl (cocoyl acrylate / myristic acid / stearic acid), cetyl palmitate, petrolatum, beeswax, carnauba wax, candelilla wax, cholesteryl hydroxystearate, glyceryl hydroxystearate, and phytosteryl hydroxystearate. [4] The method according to any one of [1] to [3], wherein the multiple emulsion is selected from the group consisting of W / O / W type, (W / O+O) / W type, (W1 / O+W2 / O) / W type, O / W / O type, (O / W+W) / O type, and (O1 / W+O2 / W) / O type. [5] The primary emulsification step is carried out in a first emulsification device, and the secondary emulsification step is carried out in a second secondary emulsification device; The method according to any one of [1] to [4], wherein the first emulsification device and the second emulsification device are disposed adjacent to each other and may be connected to each other via a flow path. [Effects of the Invention]

[0008] According to the present invention, ingredients with high melting points can also be used in the internal phase, increasing the degree of freedom in designing multiple emulsion formulations. Furthermore, by continuously emulsifying the inner emulsion by adding it to the outer phase without reheating, the size of the inner emulsion particles can be maintained small, which does not impair the texture of the multiple emulsion or the uniformity and stability of the emulsion system, and when it is formulated into a skin care product such as a cosmetic, it can provide an excellent feel when used and produce a stable product. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a conventional procedure for preparing multiple emulsions. [Figure 2] 1 is a schematic diagram showing a conventional procedure for preparing multiple emulsions. [Figure 3] FIG. 1 is a flow chart showing the preparation of ((W / O+O) / W) in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] The multiple emulsion produced by the method of the present invention refers to an emulsion structure having three or more phases, and is not particularly limited. Preferred embodiments include triple emulsions such as W / O / W type, (W / O+O) / W type, (W1 / O+W2 / O) / W type, O / W / O type, (O / W+W) / O type, and (O1 / W+O2 / W) / O type. Furthermore, examples of quadruple emulsions include O1 / W1 / O2 / W2 type and (O1 / W1)+W2 / O2 / W3 type. In these notations, W means the water phase and O means the oil phase.

[0011] The method of the present invention includes a primary emulsification step in which a primary emulsion is formed using a component having a melting point of 40°C or higher under temperature conditions equal to or higher than the melting point of the component. Here, the primary emulsion refers to the emulsion of the internal phase in a multiple emulsion; for example, if the final product is a W / O / W type or a (W / O+O) / W type, it refers to the W / O phase, and if the final product is an O / W / O type or a (O / W+W) / O type, it refers to the O / W phase. When the final product is a four- or more-fold multiple emulsion, all of the inner emulsions may be regarded as primary emulsions. For example, in the case of an O1 / W1 / O2 / W2 type emulsion, the innermost (O1 / W1) phase formed first and the (O1 / W1 / O2) phase formed subsequently may each be produced as a primary emulsion in a primary emulsification step, and then subjected to the secondary emulsification step described below under predetermined conditions.

[0012] The component having a melting point of 40° C. or higher may be any of surfactants, oil phase components, and aqueous phase components. Specific examples include various sucrose fatty acid esters (melting point 60-66° C.), tri(caprylic acid / capric acid / myristic acid / stearic acid) glyceryl (melting point 40°C), cetyl palmitate (melting point 53°C), petrolatum (melting point 57°C), beeswax (melting point 62-65°C), carnauba wax (melting point 82-86°C), candelilla wax (melting point 68-72°C), cholesteryl hydroxystearate (melting point 52°C), glyceryl hydroxystearate (melting point 74°C), and phytosteryl hydroxystearate (melting point 67°C). Even when these are used in the primary emulsion, the production method of the present invention can suppress an increase in viscosity of the primary emulsion, making it possible to stabilize the final product, a multiple emulsion.

[0013] The temperature at which emulsification is carried out in the primary emulsification step is set to be equal to or higher than the melting point of the component having a melting point of 40° C. or higher. This ensures good emulsion formation and also makes it possible to prevent the viscosity of the primary emulsion from decreasing between the primary and secondary emulsification steps. The temperature is not particularly limited as long as it is equal to or higher than the melting point of the component having a melting point of 40°C or higher, but typically it is sufficient to use a temperature 5 to 10°C higher than the melting point of the component having a melting point of 40°C or higher, for example, within a temperature range of 50 to 80°C.

[0014] The method of the present invention includes a primary emulsification step followed by a secondary emulsification step in which the primary emulsion is added to a composition containing a continuous phase which will become the outer phase to form a multiple emulsion. The continuous phase that becomes an outer phase than the primary emulsion is not limited to the outermost phase in the final product, but refers to the continuous phase adjacent to, i.e., directly dispersed in, the primary emulsion. For example, it refers to the W phase if the final product is a W / O / W type, the O phase if it is an O / W / O type, the O / W phase or W phase if it is a (W / O+O) / W type, and the W / O phase or O phase if it is an (O / W+W) / O type. When the final product is a four-fold or more multiple emulsion, the step of dispersing and emulsifying in the outer phase of the primary emulsion may be referred to as the secondary emulsification step, and the primary emulsification step and the secondary emulsification step may be repeated.

[0015] The temperature at which emulsification is carried out in the secondary emulsification step is not particularly limited, but is preferably equal to or higher than the melting point of the component having a melting point of 40°C or higher. It is also preferably equal to or higher than the temperature of the primary emulsion to be added. It is also preferable that the temperature difference between the primary emulsion to be added and the composition containing the continuous phase is within 5°C. By using these temperature conditions, emulsion formation is favorable, and the final product, a multiple emulsion, can be stabilized.

[0016] In the method of the present invention, the temperature of the primary emulsion is not changed by more than 10°C between the end of the primary emulsification step and the time of addition in the secondary emulsification step, preferably by less than 10°C, and more preferably by less than 5°C. Such a temperature change is preferably a decrease, more preferably by less than 10°C, and even more preferably by less than 5°C. By suppressing the temperature change from the primary emulsification step to the secondary emulsification step, an increase in the viscosity of the primary emulsion can be suppressed, allowing the secondary emulsification step to proceed smoothly and resulting in a stable multiple emulsion, the final product. Note that if the temperature of the primary emulsion changes by more than 20°C, particularly if it decreases by more than 20°C, the viscosity of the primary emulsion increases, preventing successful emulsification in the secondary emulsification step. In such cases, a procedure such as reheating the primary emulsion before the secondary emulsification step is required, which is time-consuming and costly. Furthermore, the internal phase size is likely to become large and non-uniform in the secondary emulsification step, resulting in a non-uniform or unstable texture of the final product and an unstable emulsion system.

[0017] Furthermore, in the method of the present invention, the addition in the secondary emulsification step is preferably carried out within 2 hours, and more preferably within 30 minutes, of the completion of the primary emulsification step. By not allowing a long time to pass between the primary emulsification step and the secondary emulsification step, a decrease in the temperature of the primary emulsion and the accompanying increase in viscosity can be suppressed, allowing the secondary emulsification step to proceed smoothly and resulting in a stable multiple emulsion, which is the final product. If more than 24 hours pass between the completion of the primary emulsification step and the addition in the secondary emulsification step, the temperature of the primary emulsion may decrease, increasing its viscosity, or the emulsified particles of the primary emulsion may coalesce, resulting in poor emulsification in the secondary emulsification step. In such cases, a procedure such as reheating the primary emulsion before the secondary emulsification step is required, which is time-consuming and costly, and which is likely to result in a large, non-uniform internal phase size during the secondary emulsification step, resulting in a non-uniform or unstable texture of the final product and an unstable emulsion system.

[0018] Suppressing the temperature change of the primary emulsion and / or shortening the time lapse from the end of the primary emulsification step to the time of addition in the secondary emulsification step may be achieved by any means. For example, each emulsification step can be performed using an emulsification apparatus (a so-called emulsification vessel), with a first emulsification apparatus for performing the primary emulsification step and a second emulsification apparatus for performing the secondary emulsification step being placed close to each other, preferably adjacent to each other, and the contents of the emulsification apparatus being continuously transferred (FIG. 2). The emulsification apparatus typically includes components with heating, stirring, and shearing functions, and may further include other components as needed. The first emulsification apparatus and the second emulsification apparatus may be connected to each other by a flow path, and it is preferable that the addition in the secondary emulsification step be performed continuously.

[0019] The operations in each emulsification step are not particularly limited to the conditions other than those described above, and can be carried out in a conventional manner. For example, the stirring speed and the magnitude of shear force during emulsification may be adjusted as desired.

[0020] The multiple emulsions produced by the method of the present invention are uniform and stable, and are therefore suitable for use in external skin preparations. The topical skin preparation is preferably in the form of a cosmetic or quasi-drug, and more preferably includes skin care cosmetics, sunscreen cosmetics, and makeup cosmetics. Preferred examples of skin care cosmetics include emulsions, essences, and serums. Sunscreen cosmetics may be for the face or body. Preferred examples of makeup cosmetics include makeup bases, foundations, concealers, BB creams, CC creams, mascaras, eye colors, blushes, and eyebrow colors.

[0021] The composition of the present invention may contain any ingredients that are used in the production of ordinary emulsions (emulsion compositions) as long as the effects of the present invention are not impaired. Examples of such optional components include oils, alcohols, ethers, powders, moisturizers, surfactants, sequestering agents, pearlescent agents, amino acids, organic amines, polymer emulsions, pH adjusters, vitamins, antioxidants, preservatives, water-soluble polymers, fragrances, and various active ingredients.

[0022] Examples of oil agents include silicone oil, polar oil, natural oil, and hydrocarbon oil.

[0023] Silicone oils include dimethylpolysiloxane (dimethicone), cyclopentasiloxane, Sun, Decamethylcyclopentasiloxane, Caprylyl Methicone, Trimethylsiloxysilicate, (Dimethicone / Vinyl Dimethicone) Crosspolymer, (Dimethicone / Phenylvinyl) Dimethicone crosspolymer, etc.

[0024] Polar oils include cetyl ethylhexanoate, octyldodecyl stearoyloxystearate, triisostearin, polyglyceryl-2 triisostearate, triethylhexanoin, isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, and isocetyl stearate. ethanol, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexylate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glyceryl di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentaneerythritol tetra-2-ethylhexylate, Glyceryl 2-ethylhexanoate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleic acid oil, cetostearyl alcohol, acetoglyceride, 2-heptylundecyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2 adipate ester oils such as 2-heptylundecyl, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, isononyl isononanoate, ethyl acetate, butyl acetate, amyl acetate, triethyl citrate, octyl methoxycinnamate, 2-ethylhexyl paramethoxycinnamate, and diethylamino hydroxybenzoyl hexyl benzoate.

[0025] Examples of natural oils include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, camellia oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, Japanese kaya oil, rice bran oil, Chinese tung oil, Japanese tung oil, jojoba oil, germ oil, sunflower oil, triglycerin, glyceryl trioctanoate, and glyceryl triisopalmitate.

[0026] Examples of hydrocarbon oils include isododecane, isohexadecane, squalane, hydrogenated poly(C6-12)olefin, and hydrogenated polyisobutene.

[0027] Examples of alcohols include monohydric alcohols such as cetanol, batyl alcohol, behenyl alcohol, palmitoleic alcohol, heptadecanol, 1-heptadecanol, stearyl alcohol, isostearyl alcohol, elaidyl alcohol, oleyl alcohol, linoleyl alcohol, elaidolinoleyl alcohol, linolenyl alcohol, elaidolinolenyl alcohol, ricinoleyl alcohol, nonadecyl alcohol, arachidyl alcohol, heneicosanol, behenyl alcohol, and erucyl alcohol; ethylene glycol, 1,3-butylene glycol, trimethylene glycol, and 1,2-butylene glycol; Dihydric alcohols such as ethylene glycol, propylene glycol, dipropylene glycol, propanediol, 1,2-pentanediol, 3-methyl-1,3-butanediol, tetramethylene glycol, 2,3-butylene glycol, pentamethylene glycol, 2-butene-1,4-diol, hexylene glycol, and octylene glycol; trihydric alcohols such as trimethylolpropane; tetrahydric alcohols such as pentaerythritol; pentahydric alcohols such as xylitol; polyhydric alcohol polymers such as triglycerin, tetraglycerin, and polyglycerin; sugar alcohols such as starch-decomposed sugar-reduced alcohols; and polyglycerin. alcohol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-methylhexyl ether, ethylene glycol isoamyl ether, ethylene glycol benzyl ether, and ethylene glycol isopropyl ether; alcohol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol isopropyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, and dipropylene glycol butyl ether; glycerin monoalkyl ethers such as xyl alcohol, selachyl alcohol, and batyl alcohol; Alcohol polymers such as diethylene glycol, triethylene glycol, polypropylene glycol, and tetraethylene glycol; Examples include glycerol; tetrahydrofurfuryl alcohol; POE-tetrahydrofurfuryl alcohol; POP-butyl ether; POP·POE-butyl ether; tripolyoxypropylene glycerin ether; POP-glycerin ether; POP-glycerin ether phosphate; POP·POE-pentaneerythritol ether, etc.

[0028] Examples of ethers include those corresponding to the above alcohols, as well as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, ethylene glycol diadipate, ethylene glycol disuccinate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and propylene glycol monophenyl ether acetate.

[0029] The powder may be spherical, needle-like, plate-like, or any other suitable shape, and examples thereof include inorganic powders (e.g., talc, kaolin, mica, sericite, muscovite, phlogopite, synthetic mica, lepidolite, biotite, vermiculite, magnesium carbonate, calcium carbonate, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, strontium silicate, tungstate metal salts, magnesium, silica, alumina, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, fluorapatite, hydroxyapatite, ceramic powder, boron nitride, etc.); organic powders (e.g., polyamide resin powder (nylon powder), polyethylene powder, polymethyl (meth)acrylate powder, polystyrene powder, styrene-acrylic acid copolymer resin powder, silicone resin powder, benzoguanamine resin powder, polytetrafluoroethylene powder, cellulose powder, etc.); metal soaps (e.g., mica, silica, alumina, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, fluorapatite, hydroxyapatite, ceramic powder, boron nitride, etc.); Zinc stearate, calcium palmitate, aluminum stearate); inorganic white pigment (e.g., titanium dioxide, zinc oxide, etc.); inorganic red pigments (e.g., iron oxide (red iron), iron titanate, etc.); inorganic brown pigments (e.g., γ-iron oxide, etc.); inorganic yellow pigments (e.g., Yellow iron oxide, ochre, etc.; inorganic black pigments (e.g., black iron oxide, low-order titanium oxide, etc.); inorganic purple pigments (e.g., mango violet, cobalt violet, etc.); inorganic green pigments (e.g., chromium oxide, chromium hydroxide, cobalt titanate, etc.); inorganic blue pigments (e.g., ultramarine, Prussian blue, etc.); pearl pigments (e.g., titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, titanium oxide-coated talc, colored titanium oxide-coated mica, bismuth oxychloride, fish scale foil, etc.); metal powder pigments (e.g., aluminum powder, copper powder, etc.); zirconium, barium or aluminum organic pigments such as ammonium lakes (e.g., organic pigments such as Red No. 201, Red No. 202, Red No. 204, Red No. 205, Red No. 220, Red No. 226, Red No. 228, Red No. 405, Orange No. 203, Orange No. 204, Yellow No. 205, Yellow No. 401, and Blue No. 404, Red No. 3, Red No. 104, Red No. 106, Red No. 227, Red No. 230, Red No. 401, Red No. 505, Orange No. 205, Yellow No. 4, Yellow No. 5, Yellow No. 202, Yellow No. 203, Green No. 3, and Blue No. 1); natural pigments (e.g., chlorophyll, β-carotene, etc.); and organically modified clay minerals (e.g., organically modified hectorite, etc.).

[0030] Examples of moisturizing agents include chondroitin sulfate, hyaluronic acid, mucoitin sulfate, caronic acid, atelocollagen, cholesteryl-12-hydroxystearate, sodium lactate, dl-pyrrolidone carboxylate, short-chain soluble collagen, diglycerin (EO)PO adduct, Rosa robur extract, yarrow extract, and melilot extract.

[0031] Surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

[0032] Examples of anionic surfactants include fatty acid soaps (e.g., sodium laurate, sodium palmitate, etc.); higher alkyl sulfates (e.g., sodium lauryl sulfate, potassium lauryl sulfate, etc.); alkyl ether sulfates (e.g., POE triethanolamine lauryl sulfate, POE sodium lauryl sulfate, etc.); N-acyl sarcosinates (e.g., sodium lauroyl sarcosinate, etc.); higher fatty acid amide sulfonates (e.g., sodium N-myristoyl-N-methyl taurate, sodium coconut oil fatty acid methyl tauride, sodium lauryl methyl tauride, etc.); phosphate salts (sodium POE oleyl ether phosphate, sodium POE stearyl ether phosphate, etc.); sulfosuccinates (e.g., sodium di-2-ethylhexyl sulfosuccinate, sodium monolauroyl monoethanolamide polyoxyethylene sulfosuccinate, sodium lauryl polypropylene glycol sulfosuccinate, etc.); sodium carboxylate, etc.); alkylbenzenesulfonates (e.g., sodium linear dodecylbenzenesulfonate, triethanolamine linear dodecylbenzenesulfonate, linear dodecylbenzenesulfonic acid, etc.); higher fatty acid ester sulfate salts (e.g., sodium hydrogenated coconut oil fatty acid glycerin sulfate, etc.); N-acylglutamates (e.g., monosodium N-lauroylglutamate, disodium N-stearoylglutamate, monosodium N-myristoyl-L-glutamate, etc.); sulfated oils (e.g., turmeric oil, etc.); POE alkyl ether carboxylic acids; POE alkyl allyl ether carboxylate salts; α-olefin sulfonates; higher fatty acid ester sulfonates; secondary alcohol sulfate salts; higher fatty acid alkylolamide sulfate salts; sodium lauroylmonoethanolamide succinate; ditriethanolamine N-palmitoyl aspartate; sodium caseinate, etc.

[0033] Examples of cationic surfactants include alkyltrimethylammonium salts (e.g., stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, etc.); alkylpyridinium salts (e.g., cetylpyridinium chloride, etc.); distearyldimethylammonium chloride dialkyldimethylammonium salts; poly(N,N'-dimethyl-3,5-methylenepiperidinium chloride); alkyl quaternary ammonium salts; alkyldimethylbenzylammonium salts; alkylisoquinolinium salts; dialkylmorphonium salts; POE alkylamines; alkylamine salts; polyamine fatty acid derivatives; amyl alcohol fatty acid derivatives; benzalkonium chloride; benzethonium chloride, etc.

[0034] Examples of amphoteric surfactants include imidazoline-based amphoteric surfactants (e.g., 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, etc.); betaine-based surfactants (e.g., 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, alkyl betaine, amido betaine, sulfobetaine, etc.).

[0035] Examples of nonionic surfactants include polyether-modified silicones (e.g., polyethylene glycol-10 dimethicone, polyethylene glycol-12 dimethicone, etc.); polyglycerin-modified silicones (e.g., polyglyceryl-3 disiloxane dimethicone, polyglyceryl-3 polydimethylsiloxyethyl dimethicone, etc.); sorbitan fatty acid esters (e.g., sorbitan monooleate, sorbitan monostearate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate, penta-2- diglycerol sorbitan ethylhexylate, diglycerol sorbitan tetra-2-ethylhexylate, etc.); glycerin fatty acids (e.g., glyceryl monocottonseed oil fatty acid, glyceryl monoerucate, glyceryl sesquioleate, glyceryl monostearate, glyceryl α,α'-oleate pyroglutamate, glyceryl (monostearate / malate), etc.); propylene glycol fatty acid esters (e.g., propylene glycol monostearate, etc.); POE castor oil / hydrogenated castor oil derivatives (POE castor oil, POE hydrogenated castor oil, etc.); non-hydrophilic nonionic surfactants such as glycerin alkyl ethers.Also, polyglycerol fatty acid esters (e.g., polyglyceryl monooleate, polyglyceryl monostearate, etc.); POE sorbitan fatty acid esters (e.g., POE sorbitan monooleate, POE sorbitan monostearate, POE sorbitan tetraoleate, etc.); POE sorbit fatty acid esters (e.g., POE sorbit monolaurate, POE sorbit monooleate, POE sorbit pentaoleate, POE sorbit monostearate, etc.); POE glycerin fatty acid esters (e.g., POE monooleates such as POE glycerin monostearate, POE glycerin monoisostearate, POE glycerin triisostearate, etc.); POE fatty acid esters (e.g., POE distearate, POE monodioleate, ethylene glycol distearate, etc.); POE alkyl ethers (e.g., POE lauryl ether, POE oleyl ether, POE stearyl ether, POE-behenyl ether, POE-2-octyldodecyl ether, POE cholestanol ether, etc.); POE alkyl phenyl ethers (e.g., POE nonylphenyl ether, etc.); Pluronic types (e.g., Pluronic (registered trademark), etc.); POE·POP alkyl ethers (e.g., POE·POP cetyl ether, POE·POP-2-decyltetradecyl ether, POE·POP monobutyl ether, POE·POP hydrogenated lanolin, POE·POP glycerin ether, etc.); tetraPOE·tetraPOP ethylenediamine condensates (e.g., , Tetronic, etc.); POE castor oil hydrogenated castor oil derivatives (e.g., POE castor oil, POE hydrogenated castor oil, POE hydrogenated castor oil monoisostearate, POE hydrogenated castor oil triisostearate, POE hydrogenated castor oil monopyroglutamic acid monoisostearate diester, POE hydrogenated castor oil maleic acid, etc.); POE beeswax / lanolin derivatives (e.g., POE sorbitol beeswax, etc.); alkanolamides (e.g., coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide, etc.); POE propylene glycol fatty acid esters; POE alkylamines; POE fatty acid amides; sucrose fatty acid esters; alkyl glucosides; alkylethoxydimethylamine oxide; and hydrophilic nonionic surfactants such as trioleyl phosphate.

[0036] Examples of sequestering agents include 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, edetate disodium, edetate trisodium, edetate tetrasodium, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, phosphoric acid, citric acid, ascorbic acid, succinic acid, edetic acid, and ethylenediaminehydroxyethyltriacetate trisodium salt.

[0037] Examples of pearlescent agents include glycol distearate and titanium mica.

[0038] Examples of the amino acid include neutral amino acids (e.g., threonine, cysteine, etc.); basic amino acids (e.g., hydroxylysine, etc.); and the amino acid derivatives include, for example, acyl sarcosine sodium (sodium lauroyl sarcosine), acyl sarcosine sodium (sodium lauroyl sarcosine), Examples of the anti-inflammatory agent include glutamic acid salts, acyl β-alanine sodium, glutathione, and pyrrolidone carboxylic acid.

[0039] Examples of organic amines include monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-methyl-1-propanol.

[0040] Examples of polymer emulsions include acrylic resin emulsion, polyethyl acrylate emulsion, acrylic resin liquid, polyacrylic alkyl ester emulsion, polyvinyl acetate resin emulsion, and natural rubber latex.

[0041] Examples of pH adjusters include buffers such as lactic acid-sodium lactate, citric acid-sodium citrate, and succinic acid-sodium succinate, and are usually used to adjust the pH of the internal phase (aqueous component).

[0042] Vitamins include, for example, vitamins A, B1, B2, B6, C, E and their derivatives. , pantothenic acid and its derivatives, biotin, etc.

[0043] Examples of antioxidants include tocopherols, dibutylhydroxytoluene (BHT), butylhydroxyanisole, pyrosulfite, gallic acid ester, phosphoric acid, citric acid, ascorbic acid, maleic acid, malonic acid, succinic acid, fumaric acid, cephalin, hexametaphosphate, phytic acid, and ethylenediaminetetraacetic acid.

[0044] Examples of preservatives include parabens and phenoxyethanol.

[0045] Examples of water-soluble polymers include plant-based polymers (e.g., gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed (marmelo), algae colloid (cassow extract), starch (coconut oil), and the like. (corn, potato, wheat), glycyrrhizic acid); microbial polymers (e.g. natural water-soluble polymers such as xanthan gum, dextran, succinoglucan, pullulan, etc.; animal polymers (e.g., collagen, casein, albumin, gelatin, etc.); Starch-based polymers (e.g., carboxymethyl starch, methylhydroxypropyl starch, etc.); cellulose-based polymers (hydroxypropylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, etc.); hydroxypropyl methylcellulose stearoxy ether, sodium cellulose sulfate, carboxymethylcellulose, sodium carboxymethylcellulose, crystalline cellulose, cellulose powder, etc.); semi-synthetic water-soluble polymers such as alginic acid polymers (e.g., sodium alginate, propylene glycol alginate, etc.); Examples include synthetic water-soluble polymers such as vinyl polymers (e.g., polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxyvinyl polymer, etc.); polyoxyethylene polymers (e.g., polyethylene glycol 20,000, 40,000, 60,000, etc.); acrylic polymers (e.g., sodium polyacrylate, polyethyl acrylate, polyacrylamide, etc.); polyethyleneimine; and cationic polymers.

[0046] Examples of various active ingredients include anti-inflammatory agents (e.g., salicylic acid derivatives, hinokitiol, zinc oxide, allantoin, etc.); whitening agents (e.g., placenta extract, saxifrage extract, arbutin, etc.); various extracts (e.g., Phellodendron bark, Coptis chinensis, Lithospermum root, Peony, Swertia japonica, Birch, sage, Loquat, Carrot, Aloe, Mallow, Iris, Grape, Job's tears, Luffa, Lily, Saffron, Cnidium rhizome, Angelica acutiloba, St. John's wort, Ononis, Garlic, Capsicum annuum, Tangerine peel, Angelica acutiloba, Seaweed, etc.), activators (e.g., Royal jelly, Photosensitizer, Cholesterol, derivatives, etc.); blood circulation promoters (e.g., nonylic acid valenylamide, nicotinic acid benzyl ester, nicotinic acid β-butoxyethyl ester, capsaicin, zingerone, cantharides tincture, ichthammol, tannic acid, α-borneol, tocopherol nicotinate, inositol hexanicotinate, cyclandelate, cinnarizine, tolazoline, acetylcholine, verapamil, cepharanthine, γ-oryzanol, etc.); antiseborrheic agents (e.g., sulfur, thianthol, etc.); anti-inflammatory agents (e.g., tranexamic acid, thiotaurine, hypotaurine, etc.), etc. [Example]

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0048] <Example> A (W / O+O) / W emulsion was produced using two adjacent emulsifying vessels according to the procedure shown in Figure 3. When adding the W / O phase, which is the primary emulsion, to the O / W phase, which is the continuous phase, the temperature change of the primary emulsion was kept within 5°C, and the addition and mixing were carried out within 15 minutes. The (W / O+O) / W emulsion composition produced was confirmed to have a high structural strength due to continuous emulsification without a temperature drop. Since reheating after primary emulsification is not required, it is assumed that the emulsion particles are fine and uniform.

[0049] <Comparative Example 1> A (W / O+O) / W emulsion was produced using two adjacent emulsification vessels according to the procedure shown in Figure 3. However, before adding the W / O phase, which is the primary emulsion, to the O / W phase, which is the continuous phase, the primary emulsion was cooled to 30°C and then reheated to 60°C (i.e., the conditions marked with * in Figure 3 were changed) before being subjected to the secondary emulsification step. It was confirmed that the (W / O+O) / W type emulsion composition produced had a larger emulsion particle size than those of the Examples.

[0050] <Comparative Example 2> A (W / O+O) / W emulsion was produced using two adjacent emulsification vessels according to the procedure shown in Figure 3. However, before adding the W / O phase, which is the primary emulsion, to the O / W phase, which is the continuous phase, the primary emulsion was left to stand in an environment of 30°C for 3 hours and then reheated to 60°C (i.e., the conditions marked with * in Figure 3 were changed) before being used in the secondary emulsification step. The (W / O+O) / W type emulsion composition produced had larger emulsified particles than those of the Examples, and the presence of crystals was confirmed. [Industrial Applicability]

[0051] The present invention allows for the use of high-melting-point ingredients in the internal phase, increasing the flexibility of multiple emulsion formulation design. Furthermore, by continuously emulsifying the internal emulsion by adding it to the external phase without reheating, the internal phase size of the emulsion particles of the internal emulsion can be maintained small. This prevents the texture of the multiple emulsion and the uniformity and stability of the emulsion system from being compromised, allowing for the creation of stable products and excellent usability when formulated into external skin preparations such as cosmetics. These effects provide manufacturing benefits and meet consumer needs, making the method extremely useful in industry.

Claims

1. a primary emulsification step of forming a primary emulsion using a component having a melting point of 40°C or higher under a temperature condition equal to or higher than the melting point of the component; a secondary emulsification step of adding the primary emulsion to a composition containing a continuous phase that will become an outer phase to form a multiple emulsion, A production method characterized in that the temperature of the primary emulsion is not changed by 10°C or more between the end of the primary emulsification step and the time of addition in the secondary emulsification step.

2. 2. The method according to claim 1, wherein the addition in the secondary emulsification step is performed within 2 hours from the end of the primary emulsification step.

3. The components with a melting point of 40°C or higher are sucrose fatty acid ester, tri(caprylic acid / caprylic 2. The method according to claim 1, wherein the surfactant is one or more selected from the group consisting of glyceryl (phosphate / myristic / stearic acid), cetyl palmitate, petrolatum, beeswax, carnauba wax, candelilla wax, cholesteryl hydroxystearate, glyceryl hydroxystearate, and phytosteryl hydroxystearate.

4. The multiple emulsion may be a W / O / W type, a (W / O+O) / W type, or a (W １ / O+W ２ / O) / W type, O / W / O type, (O / W+W) / O type, and (O １ / W+O ２ 2. The method of claim 1, wherein the hydroxyl group is selected from the group consisting of (hydroxyl group / W) / O type.

5. The primary emulsification step is carried out in a first emulsification device, and the secondary emulsification step is carried out in a second secondary emulsification device, The method of claim 1 , wherein the first emulsification device and the second emulsification device are disposed adjacent to each other and may be connected to each other by a flow path.

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