Method for improving stability of water-in-oil emulsion

Abstract

The invention discloses a method for improving the stability of a water-in-oil emulsion, which comprises the following steps of: selecting a grease thickening agent matched with the grease characteristic of an oil phase added in cosmetics needing to be prepared, and heating and physically stirring uniformly to form oleogel; uniformly mixing the oil gel with other components needing to be added into the oil phase in sequence to obtain the oil phase; the preparation method comprises the following steps: selecting a water-soluble polymer thickening agent matched with the water phase according to the water phase added in cosmetics needing to be prepared, and heating and physically stirring uniformly to form hydrogel; slowly adding hydrogel into the oil phase while stirring the oil phase; and cooling while stirring. By adopting the method, the impact force of external oil phase molecules for resisting the impact on the emulsion film is enhanced while the impact force of the internal water phase molecules for impacting the emulsion film outwards is weakened, so that the compactness of an oil-water interface can resist the impact force of the internal water phase molecules for impacting the emulsion film outwards, and the long-term storage stability of the emulsion in a range of-18 DEG C to 50 DEG C is enhanced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cosmetics, and particularly relates to a method for improving the stability of a water-in-oil emulsion. BACKGROUND

[0002] A water-in-oil (W / O) emulsion, whether it is a foundation product, a sunscreen product or a skin care cream product, has a big problem in stability, despite the thickening assistance of organic clay. In particular, in a high-temperature environment of 45-50 degrees and a low-temperature environment below-5 degrees, oiling, separation, roughness and cracking often occur. The stability of an emulsion depends on the compactness of the emulsion film formed by emulsifiers at the oil-water interface of emulsion particles. In a water-in-oil (W / O) system, the traditional method is to add inorganic salts (sodium chloride, magnesium sulfate) to the internal water phase to enhance the compactness of the emulsion film, improve the ability of the internal water phase of the emulsion particles to resist the impact of the emulsion film, and prevent the emulsion particles from coagulating to form larger and larger emulsion particles. However, in fact, the effect obtained by relying on inorganic salts is not good, especially in low-viscosity products, and emulsion products cannot be stable even at room temperature. SUMMARY

[0003] In order to solve at least one of the above problems, the present application provides a method for improving the stability of a water-in-oil emulsion.

[0004] In order to achieve the above purpose, the present application adopts the following technical means: The present application provides a method for improving the stability of a water-in-oil emulsion, comprising the following steps: S1, according to the oil properties of the oil phase added in the type of cosmetic to be prepared, selecting an oil thickener matched therewith, and uniformly mixing by heating and physical stirring to form an oil gel; S2, sequentially mixing and uniformly mixing the oil gel with other ingredients to be added in the oil phase to obtain an oil phase; S3, according to the water phase added in the type of cosmetic to be prepared, selecting a water-soluble polymer thickener matched therewith, and uniformly mixing by heating and physical stirring to form a water gel; S4, slowly adding the water gel in step S3 to the oil phase obtained in step S2 while stirring; and cooling to below 40 degrees while stirring.

[0005] In some embodiments of the present application, the oil thickening agent is selected from one or more of silica, dimethylsilylated silica, ethyl cellulose, dextrin palmitate, dextrin myristate, dextrin palmitate / ethylhexanoate, stearyl inulin, styrene / butadiene copolymer, ethylene / propylene / styrene copolymer, butene / ethylene / styrene copolymer, styrene / isoprene copolymer, styrene / methylstyrene / indene copolymer, methylstyrene / ethylene toluene copolymer, hydrogenated (styrene / butadiene) copolymer, hydrogenated (styrene / isoprene) copolymer, hydrogenated (ethylene / propylene / styrene) copolymer, hydrogenated butene / ethylene / styrene copolymer, hydrogenated (styrene / methylstyrene / indene) copolymer, glyceryl behenate / eicosanoate, polyglyceryl-6 octastearate, glyceryl behenate, glyceryl tri(behenate / isostearate / eicosadioate), dibutyl lauroyl glutamide.

[0006] In some embodiments of the present application, the water-soluble polymer thickening agent is selected from one or more of xanthan gum, carob gum, cellulose gum, guar gum, sclerotium gum, gum arabic (acacia) gum, sodium alginate, dehydroxanthan gum, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl guar gum, agar, tara gum, succinoglycan, sodium hyaluronate, glucomannan, magnesium aluminum silicate, hectorite, bentonite, sodium magnesium lithium silicate, polyvinylpyrrolidone, sodium polyacrylate, carbomer, acrylates / C10-30 alkyl acrylate crosspolymer, polyacrylamide, polyacrylate-13, acrylamide / ammonium acrylate copolymer, polyacrylate crosspolymer-6, ammonium polyacryloyldimethyl taurate, sodium ammonium polyacryloyldimethyl taurate, hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, sodium acrylate / sodium acryloyldimethyl taurate copolymer, acrylates / beheneth-25 methacrylate copolymer, acrylates / steareth-20 itaconate copolymer.

[0007] In some embodiments of the present application, the method steps further comprise the step of adding an organic clay to the oil phase to form an oil gel.

[0008] In some embodiments of the present application, the method steps further comprise the step of adding an inorganic salt to the water phase component to form a hydrogel.

[0009] In some embodiments of the present application, the inorganic salt comprises sodium chloride, magnesium sulfate.

[0010] In some embodiments of the present application, the cosmetic category comprises low to medium viscosity base makeup products, sunscreen products, and skin care creams; in some embodiments, but not limited to, foundation cream, foundation liquid, sunscreen, foundation cushion.

[0011] In some embodiments of the present application, the viscosity of the cosmetic product is controlled by adjusting the intensity and time of stirring after the water gel is finished.

[0012] In some embodiments of the present application, the oil phase is added to the cosmetic product according to the oil properties of the oil phase, and an oil thickening agent is selected to match the oil properties. The oil gel is formed by heating and physical stirring. The oil gel is mixed with other ingredients to be added to the oil phase to obtain the oil phase. The water phase is formed by heating and physical stirring according to the water phase components of the cosmetic product. The oil phase obtained above is slowly added to the water phase obtained above while stirring, and the temperature is cooled to below 40 degrees while stirring to obtain a water-in-oil emulsion with greatly improved stability.

[0013] Advantages of the present application Compared with the prior art, the present application has the following advantages: the present application provides a method for improving the stability of a water-in-oil emulsion. In this method, inorganic salts are not added to enhance the density of the emulsion film at the oil-water interface of the emulsion particles. Instead, the method uses an outer oil gel and an inner water gel. The impact force of the inner water phase molecules on the emulsion film is weakened (because the water gel can increase the surface tension between molecules and increase the pulling force between molecules), while the resistance of the outer oil phase molecules to the impact on the emulsion film is enhanced (because the oil gel can increase the surface tension between molecules and increase the pulling force between molecules), thereby increasing the density of the emulsion film at the oil-water interface. The density of the oil-water interface can resist the impact of the inner water phase molecules on the emulsion film, and the stability of the emulsion is enhanced: it can be stored for a long time in the range of -18℃-50℃. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The comparative results of the water-in-oil foundation cream prepared in Example 2 and Comparative Example 1 under -18℃-50℃ cycling conditions for 4 weeks are shown; Figure 2 The comparative results of the water-in-oil foundation liquid prepared in Example 10 and Comparative Example 2 under -18℃-50℃ cycling conditions for 4 weeks are shown; Figure 3 The comparative results of the water-in-oil sunscreen cream prepared in Example 14 and Comparative Example 3 under -18℃-50℃ cycling conditions for 4 weeks are shown; Figure 4 The comparative results of the water-in-oil sunscreen foundation air cushion prepared in Example 25 and Comparative Example 4 under -18℃-50℃ cycling conditions for 4 weeks are shown. DETAILED DESCRIPTION

[0015] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the present application, and are not intended to limit the scope of what the inventors regard as their application. One skilled in the art will recognize that the examples set forth herein represent techniques that can be used in carrying out the present application, and that changes can be made in the art without departing from the spirit and scope of the application.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The materials recited in the detailed description are incorporated herein by reference. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the application described herein. Such equivalents are intended to be encompassed by the following claims.

[0017] A method for improving the stability of a water-in-oil emulsion, comprising the steps of: S1, selecting an oil thickening agent that matches the oil properties of the oil phase to be added in the cosmetic product to be prepared, and uniformly mixing by heating and physical stirring to form an oil gel; S2, sequentially mixing and uniformly mixing the oil gel with other ingredients to be added in the oil phase to obtain an oil phase; S3, selecting a water-soluble polymer thickening agent that matches the water phase to be added in the cosmetic product to be prepared, and uniformly mixing by heating and physical stirring to form a water gel; S4, slowly adding the water gel in step S3 to the oil phase obtained in step S2 while stirring; S5, after the water gel is completely added, adjusting the stirring intensity and time according to the required viscosity, and cooling to below 40 degrees while stirring.

[0018] The oil thickening agent is selected from one or more of silica, dimethylsilylated silica, ethyl cellulose, dextrin palmitate, dextrin myristate, dextrin palmitate / ethylhexanoate, stearyl inulin, styrene / butadiene copolymer, ethylene / propylene / styrene copolymer, butene / ethylene / styrene copolymer, styrene / isoprene copolymer, styrene / methylstyrene / indene copolymer, methylstyrene / ethylene toluene copolymer, hydrogenated (styrene / butadiene) copolymer, hydrogenated (styrene / isoprene) copolymer, hydrogenated (ethylene / propylene / styrene) copolymer, hydrogenated butene / ethylene / styrene copolymer, hydrogenated (styrene / methylstyrene / indene) copolymer, glyceryl behenate / eicosanoate, polyglyceryl-6 octastearate, glyceryl behenate, glyceryl tri(behenate / isostearate / eicosadioate), dibutyl lauroyl glutamide, according to the type of cosmetic product to be prepared.

[0019] The water-soluble polymer thickening agent is selected from one or more of xanthan gum, carob gum, cellulose gum, guar gum, sclerotium gum, gum arabic (acacia) gum, sodium alginate, dehydroxanthan gum, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl guar gum, agar, tara gum, succinoglycan, sodium hyaluronate, glucomannan, magnesium aluminum silicate, hectorite, bentonite, sodium magnesium lithium silicate, polyvinylpyrrolidone, sodium polyacrylate, carbomer, acrylates / C10-30 alkyl acrylate crosspolymer, polyacrylamide, polyacrylate-13, acrylamide / ammonium acrylate copolymer, polyacrylate crosspolymer-6, ammonium polyacryloyldimethyl taurate, sodium ammonium polyacryloyldimethyl taurate, hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, sodium acrylate / sodium acryloyldimethyl taurate copolymer, acrylates / beheneth-25 methacrylate copolymer, acrylates / steareth-20 itaconate copolymer, according to the type of cosmetic product to be prepared.

[0020] The type of cosmetic product is a low-to-medium viscosity base makeup product, a sunscreen product, and a skin care emulsion, including but not limited to foundation cream, foundation liquid, sunscreen, and foundation cushion.

[0021] Further, the stability of the water-in-oil emulsion can be improved by adding organic clay to the oil gel, adding inorganic salt to the water phase component, or using a preparation method in which the oil gel and the water phase with added inorganic salt are combined.

[0022] The technical solutions of the present application will be described in further detail below with reference to specific embodiments.

[0023] Example 1 The water-in-oil foundation cream, its raw materials, and their weight ratios are as follows: Oil phase ingredients: cetyl ethylhexanoate 2.5%, neopentyl glycol diheptanoate 2.5%, dextrin palmitate 1.3%, ethylhexyl methoxy cinnamate 5%; dimethicone 13%, cetyl PEG / PPG-10 / 1 dimethicone 3%, diphenyl siloxy phenyl trimethicone 2%, PEG-9 dimethicone ethyl dimethicone 0.5%, tocopheryl acetate 0.2%, titanium dioxide (CI 77891) 5%, CI 77492 (yellow iron oxide) 0.4537%, CI 77491 (red iron oxide) 0.0825%, CI 77499 (black iron oxide) 0.0106%, titanium dioxide 3%, synthetic fluorphlogopite 0.5%, lauroyl lysine 0.5%, silica 0.5%; Aqueous ingredients: hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer 0.2%, hydroxypropyl cellulose 0.2%, sodium hyaluronate 0.05%, butylene glycol 6%, glycerin 5%, glycereth-26 0.5%, trehalose 1%, p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, the balance being deionized water.

[0024] The preparation process is as follows: S1, by heating and physical stirring or homogenization of the oil phase ingredients cetyl ethylhexanoate, neopentyl glycol diheptanoate, dextrin palmitate, ethylhexyl methoxy cinnamate to form an oil gel; S2, the oil phase ingredients dimethicone, cetyl PEG / PPG-10 / 1 dimethicone, diphenyl siloxy phenyl trimethicone, PEG-9 dimethicone ethyl dimethicone, tocopheryl acetate are added to the container and mixed uniformly, the oil gel obtained in step one is added in proportion, and homogenized and mixed uniformly; then titanium dioxide (CI 77891), CI 77491 (red iron oxide), CI 77492 (yellow iron oxide), CI 77499 (black iron oxide), titanium dioxide are added to the container and mixed uniformly; then synthetic fluorphlogopite, lauroyl lysine, silica are added to the container and mixed uniformly, to obtain an oil phase; S3, by heating and physical stirring or homogenization of the hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, hydroxypropyl cellulose, sodium hyaluronate, butylene glycol, glycerin, glycereth-26, deionized water, trehalose, p-hydroxyacetophenone, 1,2-pentanediol to form a hydrogel; S4, stirring the oil phase obtained in step S2, slowly adding the hydrogel in step S3 to the oil phase, homogenizing, stirring and cooling to below 40 degrees, finally forming a stable water-in-oil foundation cream.

[0025] Example 2 A water-in-oil foundation cream, the raw materials and weight ratio are as follows: Oil phase ingredients: Cetyl alcohol ethylhexyl ester 2.5%, Neopentyl glycol diheptanoate 2.5%, Glycerin esaminic / arachidic ester 1%; Ethylhexyl methoxy cinnamate 5%, Dimethicone 13%, Cetyl PEG / PPG-10 / 1 dimethicone 3%, Diphenyl siloxy phenyl trimethicone 2%, PEG-9 dimethicone ethyl dimethicone 0.5%, Tocopheryl acetate 0.2%, Titanium dioxide (CI 77891) 5%, CI 77492 (yellow iron oxide) 0.4537%, CI 77491 (red iron oxide) 0.0825%, CI 77499 (black iron oxide) 0.0106%, Titanium dioxide 3%, Synthetic fluorphlogopite 0.5%, Laurdiminopropane 0.5%, Silica 0.5%; Water phase ingredients: Sodium hyaluronate 0.05%, Xanthan gum 0.2%, Butylene glycol 6%, Glycerin 5%, Glycereth-26 0.5%, Tetrahexydecyl ascorbate 1%, Sodium chloride 1%, p-Hydroxyacetophenone 0.40%, 1,2-Pentanediol 1.00%, Deionized water q.s.

[0026] A water-in-oil foundation cream was prepared by emulsifying the same oil and water phases as in Example 1.

[0027] Example 3 A water-in-oil foundation cream was prepared by emulsifying the same oil and water phases as in Example 1. Oil phase ingredients: Cetyl alcohol ethylhexyl ester 2.5%, Neopentyl glycol diheptanoate 2.5%, Ethyl cellulose 1%; Ethylhexyl methoxy cinnamate 5%, Dimethicone 13%, Cetyl PEG / PPG-10 / 1 dimethicone 3%, Diphenyl siloxy phenyl trimethicone 2%, PEG-9 dimethicone ethyl dimethicone 0.5%, Tocopheryl acetate 0.2%, Titanium dioxide (CI 77891) 5%, CI 77492 (yellow iron oxide) 0.4537%, CI 77491 (red iron oxide) 0.0825%, CI 77499 (black iron oxide) 0.0106%, Titanium dioxide 3%, Synthetic fluorphlogopite 0.5%, Laurdiminopropane 0.5%, Silica 0.5%; Sodium hyaluronate 0.05%, Polyvinylpyrrolidone 0.1%, Butylene glycol 6%, Glycerin 5%, Glycereth-26 0.5%, Tetrahexydecyl ascorbate 1%, p-Hydroxyacetophenone 0.40%, 1,2-Pentanediol 1.00%, Deionized water q.s.

[0028] A water-in-oil foundation cream was prepared by emulsifying the same oil and water phases as in Example 1.

[0029] Example 4 A water-in-oil foundation cream was prepared by emulsifying the same oil and water phases as in Example 1. Oil phase ingredients: Ethylhexyl palmitate 2.5%, Neopentyl glycol diheptanoate 2.5%, Dimethicodiyl siloxane 0.4%; Ethylhexyl methoxyphenyl triazine 5%, Dimethicone 13%, Cetyl PEG / PPG-10 / 1 dimethicone 3%, Diphenyl dimethicone 2%, PEG-9 dimethicone crosspolymer 0.5%, Ascorbyl acetate 0.2%, Titanium dioxide (CI 77891) 5%, CI 77492 (Yellow iron oxide) 0.4537%, CI 77491 (Red iron oxide) 0.0825%, CI 77499 (Black iron oxide) 0.0106%, Titanium dioxide 3%, Synthetic fluorphlogopite 0.5%, Laurdimiazole 0.5%, Silica 0.5%; Aqueous phase ingredients: Magnesium aluminum silicate 0.4%, Butylene glycol 6%, Glycerin 5%, Glycereth-26 0.5%, Tetrahexyldiglycerin 1%, p-Hydroxyacetophenone 0.40%, 1,2-Pentanediol 1.00%, Deionized water q.s.

[0030] A water-in-oil foundation cream was prepared using the same oil and aqueous phases as in Example 1.

[0031] Example 5 A water-in-oil foundation cream was prepared using the same oil and aqueous phases as in Example 1. Oil phase ingredients: Ethylhexyl palmitate 2.5%, Neopentyl glycol diheptanoate 2.5%, Styrene / butadiene copolymer 1%, Ethylhexyl methoxyphenyl triazine 5%, Dimethicone 13%, Cetyl PEG / PPG-10 / 1 dimethicone 3%, Diphenyl dimethicone 2%, PEG-9 dimethicone crosspolymer 0.5%, Ascorbyl acetate 0.2%, Titanium dioxide (CI 77891) 5%, CI 77492 (Yellow iron oxide) 0.4537%, CI 77491 (Red iron oxide) 0.0825%, CI 77499 (Black iron oxide) 0.0106%, Titanium dioxide 3%, Synthetic fluorphlogopite 0.5%, Laurdimiazole 0.5%, Silica 0.5%; Aqueous phase ingredients: Hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer 0.2%, Polyvinylpyrrolidone 0.05%, Butylene glycol 6%, Glycerin 5%, Glycereth-26 0.5%, Tetrahexyldiglycerin 1%, p-Hydroxyacetophenone 0.40%, 1,2-Pentanediol 1.00%, Deionized water q.s.

[0032] Example 6 A water-in-oil foundation cream was prepared using the same oil and aqueous phases as in Example 1. Oil phase ingredients: cetyl alcohol ethylhexyl ester 2.5%, neopentyl glycol diheptanoate 2.5%, dextrin palmitate 0.8%, ethylhexyl methoxy cinnamate 5%; dimethicone 13%, cetyl PEG / PPG-10 / 1 dimethicone 3%, diphenyl siloxy phenyl trimethicone 2%, PEG-9 dimethicone ethyl dimethicone 0.5%, tocopheryl acetate 0.2%, disteardimonium hectorite 0.5%, titanium dioxide (CI 77891) 5%, CI 77492 (yellow iron oxide) 0.4537%, CI 77491 (red iron oxide) 0.0825%, CI 77499 (black iron oxide) 0.0106%, titanium dioxide 3%, synthetic fluorphlogopite 0.5%, lauroyl lysine 0.5%, silica 0.5%; Aqueous phase ingredients: hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer 0.2%, hydroxypropyl cellulose 0.2%, sodium hyaluronate 0.05%, butylene glycol 6%, glycerin 5%, glycereth-26 0.5%, trehalose 1%, p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0033] A water-in-oil foundation cream was obtained by emulsifying the same oil phase and aqueous phase as in Example 1.

[0034] Comparative Example 1 A water-in-oil foundation cream, the raw materials and weight ratio of which are as follows: Oil phase ingredients: cetyl alcohol ethylhexyl ester 2.5%, neopentyl glycol diheptanoate 2.5%, ethylhexyl methoxy cinnamate 5%, dimethicone 13%, cetyl PEG / PPG-10 / 1 dimethicone 3%, diphenyl siloxy phenyl trimethicone 2%, PEG-9 dimethicone ethyl dimethicone 0.5%, tocopheryl acetate 0.2%, disteardimonium hectorite 1.2%, titanium dioxide (CI 77891) 5%, CI 77492 (yellow iron oxide) 0.4537%, CI 77491 (red iron oxide) 0.0825%, CI 77499 (black iron oxide) 0.0106%, titanium dioxide 3%, synthetic fluorphlogopite 0.5%, lauroyl lysine 0.5%, silica 0.5%; Aqueous phase ingredients: butylene glycol 6%, glycerin 5%, glycereth-26 0.5%, trehalose 1%, sodium chloride 1%, p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0035] A water-in-oil foundation cream was obtained by emulsifying the same oil phase and aqueous phase as in Example 1.

[0036] The water-in-oil foundation cream prepared in Example 1-6, Comparative Example 1 was each taken 4 samples, and placed in 4℃, 25℃, 45℃, cycle (-18℃-50℃) conditions for stability experiment, and the sample appearance change was observed at 1, 2, 4 weeks. The results are shown in Table 1 and Figure 1 Figure 1 The comparative results of Example 2 and Comparative Example 1 under -18℃-50℃ cycle conditions for 4 weeks are shown.

[0037] Table 1 Stability experiment results of water-in-oil foundation cream prepared in Example 1-6, Comparative Example 1

[0038] The results show that the water phase composition of the water-in-oil foundation cream does not contain sodium chloride, the oil phase composition is prepared into an oil gel, the water phase composition is prepared into a water gel, and then the water gel is slowly put into the oil gel. The water-in-oil emulsion formed by this method has better stability than the method of the comparative example between -18℃-50℃.

[0039] In the preparation scheme of the water-in-oil foundation cream, the dextrin palmitate in the oil gel can also be replaced by dextrin myristate, dextrin palmitate / ethyl hexanoate, and stearyl inulin; glyceryl behenate / eicosanoate can also be replaced by polyglyceryl-6 octadecanoate, glyceryl behenate, and glyceryl tri(behenate / isostearate / eicosadioate); dimethylsilylated silica can be replaced by silica; styrene / butadiene copolymer can be replaced by ethylene / propylene / styrene copolymer, butene / ethylene / styrene copolymer, styrene / isoprene copolymer, styrene / methylstyrene / indene copolymer, methylstyrene / ethylene toluene copolymer, hydrogenated (styrene / butadiene) copolymer, hydrogenated (styrene / isoprene) copolymer, hydrogenated (ethylene / propylene / styrene) copolymer, hydrogenated butene / ethylene / styrene copolymer, and hydrogenated (styrene / methylstyrene / indene) copolymer; ​Xanthan gum and hydroxypropyl cellulose in the hydrogel can be replaced by carob gum, cellulose gum, guar gum, sclerotium gum, gum arabic (tree), sodium alginate, dehydrogenated xanthan gum, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl guar gum, agar, chitosan gum; hydroxyethyl acrylate / acryloyldimethyl sodium taurate copolymer can be replaced by sodium polyacrylate, carbomer, acrylate / C10-30 alkyl acrylate crosspolymer, polyacrylamide, polyacrylate-13, acrylamide / ammonium acrylate copolymer, polyacrylate crosspolymer-6, ammonium polyacryldimethyl taurate, sodium polyacryldimethyl taurate, sodium acrylate / acryloyldimethyl taurate copolymer, acrylate / beheneth-25 methacrylate copolymer, acrylate / steareth-20 itaconate copolymer; sodium hyaluronate can also be replaced by succinoglycan, glucomannan; magnesium aluminum silicate can also be replaced by hectorite, bentonite, sodium magnesium lithium silicate.

[0040] In the preparation of water-in-oil foundation cream, the types and proportions of toning materials can be controlled according to product requirements to prepare products of different color and color system.

[0041] Example 7 Water-in-oil foundation liquid, its raw materials and weight ratio are as follows: Oil phase ingredients: dextrin palmitate 1%, caprylic / capric triglyceride 2%; cocoyl caprylate / caprate 6%; diisostearyl malate 2%; triisostearin 1%; isostearic acid 1%; cyclopentasiloxane 9.2%; cetyl PEG / PPG-10 / 1 dimethicone 2.5%; polyglyceryl-4 isostearate 1%; phytosteryl isostearyl dimerdilinoleate 1%; tocopheryl acetate 0.2%; polyhydroxy stearic acid 0.3%; phenyl trimethicone 2%; titanium dioxide (CI 77891) 8%; CI 77492 (yellow iron oxide) 0.67%; CI 77491 (red iron oxide) 0.20%; CI 77499 (black iron oxide) 0.06%; synthetic fluorphlogopite 1%; hydrogenated (styrene / methylstyrene / indene) copolymer 4%; isododecane 4%; caprylic / capric triglyceride 1.6%; glyceryl hydrogenated rosinic acid ester 2.4%; Water phase ingredients: glycerin 4%; maltitol 0.5%; betaine 0.5%; xanthan gum 0.1%; hydroxyethyl cellulose 0.1%; sodium hyaluronate 0.02%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the rest is deionized water.

[0042] The preparation process is as follows: S1, form oil gel by heating and physical stirring or homogenization of oil phase ingredients dextrin palmitate, caprylic / capric triglyceride, coco-caprylate / caprate, diisostearyl malate, triisostearin, isostearic acid; S2, mix evenly the oil phase ingredients cyclopentasiloxane, cetyl PEG / PPG-10 / 1 dimethicone, polyglyceryl-4 isostearate, phytosteryl isostearyl dimerdilinoleate, tocopheryl acetate, polyhydroxystearic acid, phenyl trimethicone in a container, add the oil gel obtained in step one in proportion, homogenize and mix evenly; then add titanium dioxide (CI 77891), CI 77491 (red iron oxide), CI 77492 (yellow iron oxide), CI 77499 (black iron oxide), titanium dioxide in the container and mix evenly; then add synthetic fluorphlogopite, hydrogenated (styrene / methylstyrene / indene) copolymer, isododecane, caprylic / capric triglyceride, glyceryl hydrogenated rosinate in the container and mix evenly to obtain oil phase; S3, form water gel by heating and physical stirring or homogenization of glycerin, maltitol, betaine, xanthan gum, hydroxyethyl cellulose, sodium hyaluronate, deionized water, p-hydroxyacetophenone, 1,2-pentanediol; S4, stir the oil phase obtained in step S2, slowly add the water gel in step S3 into the oil phase, homogenize, and cool to below 40 degrees while stirring, finally form stable water-in-oil foundation.

[0043] Example 8 Water-in-oil foundation, its raw materials and weight ratio are as follows: Oil phase ingredients: glyceryl behenate / eicosadioate 0.6%, caprylic / capric triglyceride 2%; coco-caprylate / caprate 6%; diisostearyl malate 2%; triisostearin 1%; isostearic acid 1%; cyclopentasiloxane 9.2%; cetyl PEG / PPG-10 / 1 dimethicone 2.5%; polyglyceryl-4 isostearate 1%; phytosteryl isostearyl dimerdilinoleate 1%; tocopheryl acetate 0.2%; polyhydroxystearic acid 0.3%; phenyl trimethicone 2%; titanium dioxide (CI 77891) 8%; CI 77492 0.67%; CI 77491 (red iron oxide) 0.20%; CI 77499 (black iron oxide) 0.06%; synthetic fluorphlogopite 1%; hydrogenated (styrene / methylstyrene / indene) copolymer 4%; isododecane 4%; caprylic / capric triglyceride 1.6%; glyceryl hydrogenated rosinate 2.4%; Water phase ingredients: glycerin 4%; maltitol 0.5%; betaine 0.5%; sodium / magnesium / lithium silicate 0.2%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, remainder deionized water.

[0044] A water-in-oil foundation was emulsified using the same oil and water phases as in Example 7.

[0045] Example 9 A water-in-oil foundation was emulsified using the same oil and water phases as in Example 7. Oil phase ingredients: ethyl cellulose 0.6%, caprylic / capric triglyceride 2%; coco-caprylate / caprate 6%; diisostearyl malate 2%; triisostearin 1%; isostearic acid 1%; cyclopentasiloxane 9.2%; cetepg-10 / 1 polydimethylsiloxy methylsiloxy dimethyl polysiloxane 2.5%; polyglyceryl-4 isostearate 1%; phytosteryl isostearoyl di-mustardate 1%; tocopheryl acetate 0.2%; polyhydroxy stearic acid 0.3%; phenyl trimethicone 2%; titanium dioxide (CI 77891) 8%; CI 77492 (yellow iron oxide) 0.67%; CI 77491 (red iron oxide) 0.20%; CI 77499 (black iron oxide) 0.06%; synthetic fluorphlogopite 1%; hydrogenated (styrene / methyl styrene / indene) copolymer 4%; isododecane 4%; caprylic / capric triglyceride 1.6%; glyceryl hydrogenated rosinate 2.4%; Water phase ingredients: glycerin 4%; maltitol 0.5%; betaine 0.5%; sodium / magnesium / lithium silicate 0.2%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, remainder deionized water.

[0046] A water-in-oil foundation was emulsified using the same oil and water phases as in Example 7.

[0047] Example 10 A water-in-oil foundation was emulsified using the same oil and water phases as in Example 7. Oil phase ingredients: Dimethicodiylated silica 0.2%, Caprylic / capric triglyceride 2%; Coco-caprylate / caprate 6%; Diisostearyl malate 2%; Triisostearin 1%; Isostearic acid 1%; Cyclopentasiloxane 9.2%; Cetyl PEG / PPG-10 / 1 dimethicone 2.5%; Polyglyceryl-4 isostearate 1%; Phytosteryl isostearyl dimer dilinoleate 1%; Tocopheryl acetate 0.2%; Polyhydroxy stearic acid 0.3%; Phenyl trimethicone 2%; Titanium dioxide (CI 77891) 8%; CI 77492 (Yellow iron oxide) 0.67%; CI 77491 (Red iron oxide) 0.20%; CI 77499 (Black iron oxide) 0.06%; Synthetic fluorphlogopite 1%; Hydrogenated (styrene / methylstyrene / indene) copolymer 4%; Isododecane 4%; Caprylic / capric triglyceride 1.6%; Glycerin hydrogenated rosinate 2.4%; Aqueous phase ingredients: Glycerin 4%; Maltitol 0.5%; Betaine 0.5%; Polyvinylpyrrolidone 0.05%; p-Hydroxyacetophenone 0.40%, 1,2-Pentanediol 1.00%, with the balance being deionized water.

[0048] A water-in-oil emulsion was prepared using the same oil and aqueous phases as in Example 7.

[0049] Example 11 A water-in-oil emulsion was prepared using the same oil and aqueous phases as in Example 7. Oil phase ingredients: Dimethicodiylated silica 0.2%, Caprylic / capric triglyceride 2%; Coco-caprylate / caprate 6%; Diisostearyl malate 2%; Triisostearin 1%; Isostearic acid 1%; Cyclopentasiloxane 9.2%; Cetyl PEG / PPG-10 / 1 dimethicone 2.5%; Polyglyceryl-4 isostearate 1%; Phytosteryl isostearyl dimer dilinoleate 1%; Tocopheryl acetate 0.2%; Polyhydroxy stearic acid 0.3%; Phenyl trimethicone 2%; Titanium dioxide (CI 77891) 8%; CI 77492 (Yellow iron oxide) 0.67%; CI 77491 (Red iron oxide) 0.20%; CI 77499 (Black iron oxide) 0.06%; Synthetic fluorphlogopite 1%; Hydrogenated (styrene / methylstyrene / indene) copolymer 4%; Isododecane 4%; Caprylic / capric triglyceride 1.6%; Glycerin hydrogenated rosinate 2.4%; Aqueous phase ingredients: Glycerin 4%; Maltitol 0.5%; Betaine 0.5%; Xanthan gum 0.2%; p-Hydroxyacetophenone 0.40%, 1,2-Pentanediol 1.00%, with the balance being deionized water.

[0050] A water-in-oil emulsion was prepared using the same oil and aqueous phases as in Example 7.

[0051] Example 12 A water-in-oil foundation with the following raw materials and weight ratios: Oil phase ingredients: Dibutyl lauryl glutamide 0.2%; Caprylic / capric triglyceride 2%; Coco-caprylate / caprate 6%; Diisostearyl malate 2%; Triisostearin 1%; Isostearic acid 1%; Cyclopentasiloxane 9.2%; Cetyl PEG / PPG-10 / 1 dimethicone 2.5%; Polyglyceryl-4 isostearate 1%; Phytosteryl isostearyl dimerdylate 1%; Tocopheryl acetate 0.2%; Polyhydroxystearic acid 0.3%; Phenyl trimethicone 2%; Titanium dioxide (CI 77891) 8%; CI 77492 (Yellow iron oxide) 0.67%; CI 77491 (Red iron oxide) 0.20%; CI 77499 (Black iron oxide) 0.06%; Synthetic fluorphlogopite 1%; Hydrogenated (styrene / methylstyrene / indene) copolymer 4%; Isododecane 4%; Caprylic / capric triglyceride 1.6%; Glycerin hydrogenated rosinate 2.4%; Water phase ingredients: Glycerin 4%; Maltitol 0.5%; Betaine 0.5%; Xanthan gum 0.1%; Sodium acrylates / acryloyldimethyl taurate copolymer 0.1%; p-Hydroxyacetophenone 0.40%, 1,2-Pentanediol 1.00%, and the balance deionized water.

[0052] A water-in-oil foundation was obtained by emulsifying the same oil and water phases as in Example 7.

[0053] Example 13 A water-in-oil foundation with the following raw materials and weight ratios: Oil phase ingredients: Dibutyl lauryl glutamide 0.2%; Caprylic / capric triglyceride 2%; Coco-caprylate / caprate 6%; Diisostearyl malate 2%; Triisostearin 1%; Isostearic acid 1%; Cyclopentasiloxane 9.2%; Cetyl PEG / PPG-10 / 1 dimethicone 2.5%; Polyglyceryl-4 isostearate 1%; Phytosteryl isostearyl dimerdylate 1%; Tocopheryl acetate 0.2%; Polyhydroxystearic acid 0.3%; Phenyl trimethicone 2%; Titanium dioxide (CI 77891) 8%; CI 77492 (Yellow iron oxide) 0.67%; CI 77491 (Red iron oxide) 0.20%; CI 77499 (Black iron oxide) 0.06%; Synthetic fluorphlogopite 1%; Hydrogenated (styrene / methylstyrene / indene) copolymer 4%; Isododecane 4%; Caprylic / capric triglyceride 1.6%; Glycerin hydrogenated rosinate 2.4%; Water phase ingredients: glycerin 4%; maltitol 0.5%; sodium chloride 1%; betaine 0.5%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0054] The same oil phase and water phase as in Example 7 were emulsified to obtain a water-in-oil foundation.

[0055] Comparative Example 2 A water-in-oil foundation was prepared using the following raw materials and weight ratios: Oil phase ingredients: caprylic / capric triglyceride 2%; cocoyl octanoate 6%; diisostearyl malate 2%; triisostearin 1%; isostearic acid 1%; cyclomethicone 9.2%; cetyl PEG / PPG-10 / 1 dimethicone 2.5%; polyglyceryl-4 isostearate 1%; phytosteryl isostearyl dimerdilinoleate 1%; tocopheryl acetate 0.2%; polyhydroxystearic acid 0.3%; phenyltrimethicone 2%; disteardimonium hectorite 0.8%; titanium dioxide (CI 77891) 8%; CI 77492 (yellow iron oxide) 0.67%; CI 77491 (red iron oxide) 0.20%; CI 77499 (black iron oxide) 0.06%; synthetic fluorphlogopite 1%; hydrogenated (styrene / methylstyrene / indene) copolymer 4%; isododecane 4%; caprylic / capric triglyceride 1.6%; glyceryl hydrogenated rosinate 2.4%; Water phase ingredients: glycerin 4%; maltitol 0.5%; sodium chloride 1%; betaine 0.5%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0056] The same oil phase and water phase as in Example 7 were emulsified to obtain a water-in-oil foundation.

[0057] Four samples of the water-in-oil foundation obtained in Examples 7-13 and Comparative Example 2 were each placed in a stability test under the conditions of 4°C, 25°C, 45°C, and -18°C-50°C cycling, and the appearance of the samples was observed at 1, 2, and 4 weeks. The results are shown in Table 2 and Figure 2 Figure 2 The comparative results of Example 10 and Comparative Example 2 after 4 weeks under -18°C-50°C cycling are shown.

[0058] Table 2 Stability test results for the water-in-oil foundation obtained in Examples 7-13 and Comparative Example 2

[0059] ​The results show that the water phase of the water-in-oil foundation does not contain sodium chloride, and the oil phase is prepared into an oil gel, the water phase is prepared into a water gel, and then the water gel is slowly added into the oil gel. The water-in-oil emulsion formed by the method has better stability than the emulsion formed by the comparative method between-18℃ and 50℃.

[0060] In the preparation of the water-in-oil foundation, the dextrin palmitate in the oil gel can be replaced by dextrin myristate, dextrin palmitate / ethylhexanoate, or stearyl inulin; the glyceryl behenate / eicosanoate can be replaced by polyglyceryl-6 octastearate, glyceryl behenate, or glyceryl tri(behenate / isostearate / eicosadioate); the dimethicodiylated silica can be replaced by silica; the styrene / butadiene copolymer can be replaced by ethylene / propylene / styrene copolymer, butene / ethylene / styrene copolymer, styrene / isoprene copolymer, styrene / methylstyrene / indene copolymer, methylstyrene / ethylene toluene copolymer, hydrogenated (styrene / butadiene) copolymer, hydrogenated (styrene / isoprene) copolymer, hydrogenated (ethylene / propylene / styrene) copolymer, hydrogenated butene / ethylene / styrene copolymer, or hydrogenated (styrene / methylstyrene / indene) copolymer. In the water gel, the xanthan gum and the hydroxypropyl cellulose can be replaced by carob gum, cellulose gum, guar gum, sclerotium gum, gum arabic (tree) gum, sodium alginate, dehydrogenated xanthan gum, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl guar gum, agar, or chitosan gum; the hydroxyethyl acrylate / acryloyldimethyltaurate sodium copolymer can be replaced by sodium polyacrylate, carbomer, acrylates / C10-30 alkyl acrylate crosspolymer, polyacrylamide, polyacrylate-13, acrylamide / ammonium acrylate copolymer, polyacrylate crosspolymer-6, ammonium polyacryloyldimethyl taurate, sodium polyacryloyldimethyl taurate, sodium acrylates / acryloyldimethyltaurate copolymer, acrylates / beheneth-25 methacrylate copolymer, or acrylates / steareth-20 itaconate copolymer; the sodium hyaluronate can be replaced by succinoglycan or glucomannan; and the magnesium aluminum silicate can be replaced by hectorite, bentonite, or sodium magnesium lithium silicate.

[0061] In the preparation of the water-in-oil foundation, the types and proportions of the color adjusting materials can be controlled according to product requirements to prepare products with different color values and color systems.

[0062] Example 14 The water-in-oil sunscreen cream contains the following raw materials and has the following weight ratio: Oil phase ingredients: dextrin palmitate 0.8%; isohexadecane 2.5%; ethylhexyl methoxy cinnamate 6.0%; diisopropyl sebacate 2.0%; diethylamino hydroxybenzoyl hexyl benzoate 3.0%; isopropyl lauroyl sarcosinate 2.0%; C9-12 alkane 14%; cetepg / PPG-10 / 1 dimethicone 0.5%; polyglyceryl-3 dimethicinyl hydroxyethyl dimethicone 2.0%; PEG-9 dimethicone ethyl dimethicone 0.7%, phenyl trimethicone 0.5%, polyhydroxystearic acid 0.3%, zinc oxide 7%; titanium dioxide 5%; CI 77492 (yellow iron oxide) 0.076%; CI 77491 (red iron oxide) 0.002%; styrene / DVB crosspolymer 0.8%; acrylates crosspolymer 0.8%; HDI / trihydroxymethyl hexyl lactone crosspolymer 0.5%; silica 0.5%; cyclopentasiloxane 2.0%; trimethylsiloxysilicate 2.0%; Water phase ingredients: xanthan gum 0.3%; hydroxypropyl cellulose 0.1%; dipropylene glycol 4.0%; butylene glycol 2.0%; tromethamine 1.25%; phenyl benzimidazole sulfonic acid 2.5%; methylene bis-benzotriazolyl tetramethylbutylphenol 3.0%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, the balance being deionized water.

[0063] The preparation process is as follows: S1, by heating and physical stirring or homogenization of the oil phase ingredients dextrin palmitate, isohexadecane, ethylhexyl methoxy cinnamate, diisopropyl sebacate to form an oil gel; S2, the oil phase ingredients diethylamino hydroxybenzoyl hexyl benzoate, isopropyl lauroyl sarcosinate, C9-12 alkane, cetepg / PPG-10 / 1 dimethicone, polyglyceryl-3 dimethicinyl hydroxyethyl dimethicone, PEG-9 dimethicone ethyl dimethicone, phenyl trimethicone, polyhydroxystearic acid are mixed uniformly in a container, the oil gel obtained before is added in proportion, and homogenized and mixed uniformly; then zinc oxide, titanium dioxide, CI 77492 (yellow iron oxide), CI 77491 (red iron oxide) are added in the container and mixed uniformly; then styrene / DVB crosspolymer, acrylates crosspolymer, HDI / trihydroxymethyl hexyl lactone crosspolymer, silica, cyclopentasiloxane, trimethylsiloxysilicate are added in the container and mixed uniformly, to obtain an oil phase; S3, by heating and physical stirring or homogenization of xanthan gum, hydroxypropyl cellulose, dipropylene glycol, butylene glycol, tromethamine, phenyl benzimidazole sulfonic acid, methylene bis-benzotriazolyl tetramethylbutylphenol, deionized water, p-hydroxyacetophenone, 1,2-pentanediol to form a water gel; S4, stirring the oil phase obtained in step S2, slowly adding the hydrogel in step S3 into the oil phase, homogenizing, stirring and cooling to below 40 degrees, and finally forming a stable water-in-oil sunscreen cream.

[0064] Example 15 A water-in-oil sunscreen cream, the raw materials and weight ratio of which are as follows: Oil phase ingredients: glyceryl behenate / eicosadioate 0.5%; isohexadecane 2.5%; methoxy cinnamate ethylhexyl 6.0%; diisopropyl sebacate 2.0%; diethylamino hydroxybenzoyl hexyl benzoate 3.0%; isopropyl lauroyl sarcosinate 2.0%; C9-12 alkane 14%; cetyl PEG / PPG-10 / 1 dimethicone 0.5%; polyglyceryl-3 polydimethylsiloxyethyl dimethicone 2.0%; PEG-9 polydimethylsiloxyethyl dimethicone 0.7%, phenyl trimethicone 0.5%, polyhydroxystearic acid 0.3%, zinc oxide 7%; titanium dioxide 5%; CI 77492 (yellow iron oxide) 0.076%; CI 77491 (red iron oxide) 0.002%; styrene / DVB crosslinked copolymer 0.8%; acrylic crosslinked polymer 0.8%; HDI / trihydroxymethylhexyl lactone crosslinked polymer 0.5%; silica 0.5%; cyclopentasiloxane 2.0%; trimethylsiloxy silicate 2.0%; Water phase ingredients: xanthan gum 0.3%; hectorite 0.1%; dipropylene glycol 4.0%; butylene glycol 2.0%; tromethamine 1.25%; phenyl benzimidazole sulfonic acid 2.5%; methylene bis-benzotriazolyl tetramethylbutylphenol 3.0%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0065] A water-in-oil sunscreen cream was obtained by emulsifying the same oil and water phase gel as in Example 14.

[0066] Example 16 A water-in-oil sunscreen cream, the raw materials and weight ratio of which are as follows: Oil phase ingredients: ethyl cellulose 0.5%; isohexyldecyl 2.5%; methoxycinnamate 6.0%; diisopropyl sebacate 2.0%; diethylamino hydroxybenzoyl hexyl benzoate 3.0%; isopropyl lauroyl sarcosinate 2.0%; C9-12 alkane 14%; cetyl PEG / PPG-10 / 1 dimethicone 0.5%; polyglyceryl-3 polydimethylsiloxyethyl dimethicone 2.0%; PEG-9 polydimethylsiloxyethyl dimethicone 0.7%, phenyl trimethicone 0.5%, polyhydroxystearic acid 0.3%, zinc oxide 7%; titanium dioxide 5%; CI 77492 (yellow iron oxide) 0.076%; CI 77491 (red iron oxide) 0.002%; styrene / DVB crosspolymer 0.8%; acrylates crosspolymer 0.8%; HDI / trihydroxymethylhexyl lactone crosspolymer 0.5%; silica 0.5%; cyclotetrasiloxane 2.0%; trimethylsiloxysilicate 2.0%; Aqueous phase ingredients: xanthan gum 0.3%; hydroxypropyl cellulose 0.1%; dipropylene glycol 4.0%; butylene glycol 2.0%; tromethamine 1.25%; phenylbenzimidazole sulfonic acid 2.5%; methylene bis-benzotriazolyl tetramethylbutylphenol 3.0%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0067] A water-in-oil sunscreen was emulsified using the same oil and aqueous phases as in Example 14.

[0068] Example 17 A water-in-oil sunscreen was emulsified using the same oil and aqueous phases as in Example 14. Oil phase ingredients: dimethylsilylated silica 0.2%; isohexyldecyl 2.5%; methoxycinnamate 6.0%; diisopropyl sebacate 2.0%; diethylamino hydroxybenzoyl hexyl benzoate 3.0%; isopropyl lauroyl sarcosinate 2.0%; C9-12 alkane 14%; cetyl PEG / PPG-10 / 1 dimethicone 0.5%; polyglyceryl-3 polydimethylsiloxyethyl dimethicone 2.0%; PEG-9 polydimethylsiloxyethyl dimethicone 0.7%, phenyl trimethicone 0.5%, polyhydroxystearic acid 0.3%, zinc oxide 7%; titanium dioxide 5%; CI 77492 (yellow iron oxide) 0.076%; CI 77491 (red iron oxide) 0.002%; styrene / DVB crosspolymer 0.8%; acrylates crosspolymer 0.8%; HDI / trihydroxymethylhexyl lactone crosspolymer 0.5%; silica 0.5%; cyclotetrasiloxane 2.0%; trimethylsiloxysilicate 2.0%; Aqueous phase ingredients: xanthan gum 0.3%; hydroxypropyl cellulose 0.1%; dipropylene glycol 4.0%; butylene glycol 2.0%; tromethamine 1.25%; phenylbenzimidazole sulfonic acid 2.5%; methylene bis-benzotriazolyl tetramethylbutylphenol 3.0%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, with the balance being deionized water.

[0069] A water-in-oil sunscreen was emulsified using the same oil and aqueous phase as in Example 14.

[0070] Example 18 A water-in-oil sunscreen was emulsified using the same oil and aqueous phase as in Example 14. Oil phase ingredients: styrene / butadiene copolymer 0.5%; isohexadecane 2.5%; ethylhexyl methoxy cinnamate 6.0%; diisopropyl sebacate 2.0%; diethylamino hydroxybenzoyl hexyl benzoate 3.0%; isopropyl lauroyl sarcosinate 2.0%; C9-12 alkane 14%; cetepg / PPG-10 / 1 dimethicone 0.5%; polyglyceryl-3 polydimethylsiloxyethyl dimethicone 2.0%; PEG-9 polydimethylsiloxyethyl dimethicone 0.7%, phenyl trimethicone 0.5%, polyhydroxystearic acid 0.3%, zinc oxide 7%; titanium dioxide 5%; CI 77492 (yellow iron oxide) 0.076%; CI 77491 (red iron oxide) 0.002%; styrene / DVB crosspolymer 0.8%; acrylates crosspolymer 0.8%; HDI / trihydroxymethylhexyl lactone crosspolymer 0.5%; silica 0.5%; cyclotetrasiloxane 2.0%; trimethylsiloxysilicate 2.0%; Aqueous phase ingredients: xanthan gum 0.3%; hydroxypropyl cellulose 0.1%; dipropylene glycol 4.0%; butylene glycol 2.0%; tromethamine 1.25%; phenylbenzimidazole sulfonic acid 2.5%; methylene bis-benzotriazolyl tetramethylbutylphenol 3.0%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, with the balance being deionized water.

[0071] A water-in-oil sunscreen was emulsified using the same oil and aqueous phase as in Example 14.

[0072] Example 19 A water-in-oil sunscreen was emulsified using the same oil and aqueous phase as in Example 14. Oil phase ingredients: Dextrin palmitate 0.3%; isohexadecane 2.5%; ethylhexyl methoxy cinnamate 6.0%; diisopropyl sebacate 2.0%; diethylamino hydroxybenzoyl hexyl benzoate 3.0%; isopropyl lauroyl sarcosinate 2.0%; C9-12 alkane 14%; cetyl PEG / PPG-10 / 1 dimethicone 0.5%; polyglyceryl-3 polydimethylsiloxyethyl dimethicone 2.0%; PEG-9 polydimethylsiloxyethyl dimethicone 0.7%, phenyl trimethicone 0.5%, polyhydroxystearic acid 0.3%, disteardimonium hectorite 0.4%; zinc oxide 7%; titanium dioxide 5%; CI 77492 (yellow iron oxide) 0.076%; CI 77491 (red iron oxide) 0.002%; styrene / DVB crosspolymer 0.8%; acrylates crosspolymer 0.8%; HDI / trihydroxymethylhexyl lactone crosspolymer 0.5%; silica 0.5%; cyclotetrasiloxane 2.0%; trimethylsiloxysilicate 2.0%; Water phase ingredients: xanthan gum 0.3%; hydroxypropyl cellulose 0.1%; dipropylene glycol 4.0%; butylene glycol 2.0%; tromethamine 1.25%; phenylbenzimidazole sulfonic acid 2.5%; methylene bis-benzotriazolyl tetramethylbutylphenol 3.0%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0073] A water-in-oil sunscreen was prepared using the same oil and water phases as in Example 14.

[0074] Comparative Example 3 A water-in-oil sunscreen was prepared using the same oil and water phases as in Example 14. Oil phase ingredients: isohexadecane 2.5%; ethylhexyl methoxy cinnamate 6.0%; diisopropyl sebacate 2.0%; diethylamino hydroxybenzoyl hexyl benzoate 3.0%; isopropyl lauroyl sarcosinate 2.0%; C9-12 alkane 14%; cetyl PEG / PPG-10 / 1 dimethicone 0.5%; polyglyceryl-3 polydimethylsiloxyethyl dimethicone 2.0%; PEG-9 polydimethylsiloxyethyl dimethicone 0.7%, phenyl trimethicone 0.5%, polyhydroxystearic acid 0.3%, disteardimonium hectorite 0.6%; zinc oxide 7%; titanium dioxide 5%; CI 77492 (yellow iron oxide) 0.076%; CI 77491 (red iron oxide) 0.002%; styrene / DVB crosspolymer 0.8%; acrylates crosspolymer 0.8%; HDI / trihydroxymethylhexyl lactone crosspolymer 0.5%; silica 0.5%; cyclotetrasiloxane 2.0%; trimethylsiloxysilicate 2.0%; Aqueous phase ingredients: dipropylene glycol 4.0%; sodium chloride 1%; butylene glycol 2.0%; tromethamine 1.25%; phenylbenzimidazole sulfonic acid 2.5%; methylene bis-benzotriazolyl tetramethylbutylphenol 3.0%; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0075] The same oil and aqueous phase gel emulsion as in Example 14 was used to obtain a water-in-oil sunscreen.

[0076] Four samples of the water-in-oil sunscreen obtained in Examples 14-19 and Comparative Example 3 were placed in stability tests at 4°C, 25°C, 45°C, and -18°C to 50°C cycling, and the appearance of the samples was observed at 1, 2, and 4 weeks. The results are shown in Table 3 and Figure 3 Figure 3 The comparative results of Examples 14 and Comparative Example 3 at -18°C to 50°C cycling for 4 weeks are shown.

[0077] Table 3 Stability test results for the water-in-oil sunscreen obtained in Examples 14-19 and Comparative Example 3

[0078] The results show that the water-in-oil sunscreen does not contain sodium chloride in the aqueous phase ingredients, and that the oil phase ingredients are prepared into an oil gel and the aqueous phase ingredients are prepared into an aqueous gel, which is then slowly added to the oil gel. The water-in-oil emulsion formed by this method has better stability than the emulsion obtained by the method of the comparative example between -18°C and 50°C, has a long shelf life, and has long-term stability.

[0079] In the preparation of the water-in-oil sunscreen, the dextrin palmitate in the oil gel can also be replaced by dextrin myristate, dextrin palmitate / ethyl hexanoate, or stearyl inulin; the glyceryl behenate / eicosanoate can also be replaced by polyglyceryl-6 octastearate, glyceryl behenate, or glyceryl tri(behenate / isostearate / eicosadioate); the dimethylsilylated silica can be replaced by silica; and the styrene / butadiene copolymer can be replaced by ethylene / propylene / styrene copolymer, butene / ethylene / styrene copolymer, styrene / isoprene copolymer, styrene / methylstyrene / indene copolymer, methylstyrene / ethylene toluene copolymer, hydrogenated (styrene / butadiene) copolymer, hydrogenated (styrene / isoprene) copolymer, hydrogenated (ethylene / propylene / styrene) copolymer, hydrogenated butene / ethylene / styrene copolymer, or hydrogenated (styrene / methylstyrene / indene) copolymer. ​Xanthan gum and hydroxypropyl cellulose in the hydrogel can be replaced by carob gum, cellulose gum, guar gum, sclerotium gum, gum arabic (tree) gum, sodium alginate, dehydrogenated xanthan gum, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl guar gum, agar, chitosan gum; hectorite can be replaced by magnesium aluminum silicate, bentonite, sodium magnesium lithium silicate.

[0080] In the preparation scheme of the water-in-oil sunscreen cream, the types and proportions of the color adjusting materials can be controlled according to product requirements to prepare products with different color values and color systems.

[0081] Example 20 The water-in-oil sunscreen foundation air cushion, the raw materials and the weight ratio are as follows: Oil phase ingredients: dextrin palmitate 1.2%; methoxyethylhexyl cinnamate 6%; C9-12 alkyl 4%, ethylhexyl salicylate 3%; phenyl trimethicone 5%; diisostearyl malate 4%; lauryl PEG-9 polydimethylsiloxyethyl dimethicone 1%; cetyl PEG / PPG-10 / 1 polydimethylsiloxane 2.5%; polyglyceryl-2 dipolyhydroxystearate 0.5%; cyclopentasiloxane 6%; nano titanium dioxide 8%; titanium dioxide (CI 77891) 6%; CI 77492 (yellow iron oxide) 0.888%; CI 77491 (red iron oxide) 0.181%; CI 77499 (black iron oxide) 0.05%; styrene / DVB crosslinked copolymer 3%; dimethicone 6%; trimethylsiloxy silicate 6%; Water phase ingredients: butanediol 3%; glycerin 5%; xanthan gum 0.05%; hectorite 0.05%; tromethamine 1.58%; phenyl benzimidazole sulfonic acid 3%; methylene bis-benzotriazolyl tetramethylbutylphenol 2.5; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance is deionized water.

[0082] The preparation process is as follows: S1, form an oil gel by heating and physically stirring or homogenizing the oil phase ingredients dextrin palmitate, methoxyethylhexyl cinnamate, C9-12 alkyl, ethylhexyl salicylate; S2, the oil phase ingredients phenyl trimethicone, diisostearyl malate, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, cetyl PEG / PPG-10 / 1 polydimethylsiloxane, polyglyceryl-2 dipolyhydroxystearate, cyclopentasiloxane, are added into a container and mixed evenly, the oil gel obtained in the previous step is added in proportion and mixed evenly; then nano titanium dioxide, titanium dioxide (CI 77891), CI 77492 (yellow iron oxide), CI 77491 (red iron oxide), CI 77499 (black iron oxide) are added into the container and mixed evenly; then styrene / DVB cross-linked copolymer, dimethicone, trimethylsiloxysilicate are added into the container and mixed evenly to obtain the oil phase; S3, the water gel is formed by heating and physical stirring or homogenization of butanediol, glycerol, xanthan gum, water hectorite, tromethamine, phenyl benzimidazole sulfonic acid, methylene bis-benzotriazolyl tetramethylbutylphenol, deionized water, p-hydroxyacetophenone, 1,2-pentanediol; S4, the oil phase obtained in step S2 is stirred, the water gel in step S3 is slowly added into the oil phase, and homogenized, and then cooled to below 40 degrees while stirring to form a stable water-in-oil sunscreen foundation air cushion.

[0083] Example 21 The water-in-oil sunscreen foundation air cushion, its raw materials and weight ratio are as follows: Oil phase ingredients: glyceryl behenate / eicosadioate 0.8%; methoxyethyl salicylate 6%; C9-12 alkyl 4%, ethylhexyl salicylate 3%; phenyl trimethicone 5%; diisostearyl malate 4%; lauryl PEG-9 polydimethylsiloxyethyl dimethicone 1%; cetyl PEG / PPG-10 / 1 polydimethylsiloxane 2.5%; polyglyceryl-2 dipolyhydroxystearate 0.5%; cyclopentasiloxane 6%; nano titanium dioxide 8%; titanium dioxide (CI 77891) 6%; CI 77492 (yellow iron oxide) 0.888%; CI 77491 (red iron oxide) 0.181%; CI 77499 (black iron oxide) 0.05%; styrene / DVB cross-linked copolymer 3%; dimethicone 6%; trimethylsiloxysilicate 6%; Water phase ingredients: butanediol 3%; glycerol 5%; xanthan gum 0.05%; water hectorite 0.05%; tromethamine 1.58%; phenyl benzimidazole sulfonic acid 3%; methylene bis-benzotriazolyl tetramethylbutylphenol 2.5; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance is deionized water.

[0084] The same oil phase and water phase double-phase gel emulsion as in Example 20 is used to obtain a water-in-oil sunscreen foundation air cushion.

[0085] Example 22 A water-in-oil sunscreen foundation cushion, its raw materials and weight ratio are as follows: Oil phase ingredients: ethyl cellulose 0.8%; ethylhexyl methoxy cinnamate 6%; C9-12 alkane 4%, ethylhexyl salicylate 3%; phenyl trimethicone 5%; diisostearyl malate 4%; lauryl PEG-9 polydimethylsiloxyethyl dimethicone 1%; cetyl PEG / PPG-10 / 1 dimethicone 2.5%; polyglyceryl-2 dipolyhydroxystearate 0.5%; cyclopentasiloxane 6%; nano titanium dioxide 8%; titanium dioxide (CI 77891) 6%; CI 77492 (yellow iron oxide) 0.888%; CI 77491 (red iron oxide) 0.181%; CI 77499 (black iron oxide) 0.05%; styrene / DVB cross-linked copolymer 3%; dimethicone 6%; trimethylsiloxysilicate 6%; Water phase ingredients: butylene glycol 3%; glycerin 5%; xanthan gum 0.05%; hectorite 0.05%; tromethamine 1.58%; phenyl benzimidazole sulfonic acid 3%; methylene bis-benzotriazolyl tetramethylbutylphenol 2.5; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, the rest is deionized water.

[0086] A water-in-oil sunscreen foundation cushion is obtained by emulsifying the same oil phase and water phase double-phase gel as in Example 20.

[0087] Example 23 A water-in-oil sunscreen foundation cushion, its raw materials and weight ratio are as follows: Oil phase ingredients: dimethyl silylated silica 0.3%; ethylhexyl methoxy cinnamate 6%; C9-12 alkane 4%, ethylhexyl salicylate 3%; phenyl trimethicone 5%; diisostearyl malate 4%; lauryl PEG-9 polydimethylsiloxyethyl dimethicone 1%; cetyl PEG / PPG-10 / 1 dimethicone 2.5%; polyglyceryl-2 dipolyhydroxystearate 0.5%; cyclopentasiloxane 6%; nano titanium dioxide 8%; titanium dioxide (CI 77891) 6%; CI 77492 (yellow iron oxide) 0.888%; CI 77491 (red iron oxide) 0.181%; CI 77499 (black iron oxide) 0.05%; styrene / DVB cross-linked copolymer 3%; dimethicone 6%; trimethylsiloxysilicate 6%; Water phase ingredients: butylene glycol 3%; glycerin 5%; xanthan gum 0.05%; hectorite 0.05%; tromethamine 1.58%; phenyl benzimidazole sulfonic acid 3%; methylene bis-benzotriazolyl tetramethylbutylphenol 2.5; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, the rest is deionized water.

[0088] A water-in-oil sunscreen foundation cushion was emulsified using the same oil and water phase double gel as in Example 20.

[0089] Example 24 A water-in-oil sunscreen foundation cushion was emulsified using the same oil and water phase double gel as in Example 20. Oil phase ingredients: styrene / butadiene copolymer 0.7%; ethylhexyl methoxy cinnamate 6%; C9-12 alkyl 4%, ethylhexyl salicylate 3%; phenyl trimethicone 5%; diisostearyl malate 4%; lauryl PEG-9 polydimethylsiloxyethyl dimethicone 1%; cetyl PEG / PPG-10 / 1 polydimethylsiloxane 2.5%; polyglyceryl-2 dipolyhydroxystearate 0.5%; cyclopentasiloxane 6%; nanometer titanium dioxide 8%; titanium dioxide (CI 77891) 6%; CI 77492 (yellow iron oxide) 0.888%; CI 77491 (red iron oxide) 0.181%; CI 77499 (black iron oxide) 0.05%; styrene / DVB cross-linked copolymer 3%; dimethicone 6%; trimethylsiloxysilicate 6%; Water phase ingredients: butylene glycol 3%; glycerin 5%; xanthan gum 0.05%; hectorite 0.05%; tromethamine 1.58%; phenyl benzimidazole sulfonic acid 3%; methylene bis-benzotriazolyl tetramethylbutylphenol 2.5; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0090] A water-in-oil sunscreen foundation cushion was emulsified using the same oil and water phase double gel as in Example 20.

[0091] Example 25 A water-in-oil sunscreen foundation cushion was emulsified using the same oil and water phase double gel as in Example 20. Oil phase ingredients: dextrin palmitate 0.7%; ethylhexyl methoxy cinnamate 6%; C9-12 alkyl 4%, ethylhexyl salicylate 3%; phenyl trimethicone 5%; diisostearyl malate 4%; lauryl PEG-9 polydimethylsiloxyethyl dimethicone 1%; cetyl PEG / PPG-10 / 1 polydimethylsiloxane 2.5%; polyglyceryl-2 dipolyhydroxystearate 0.5%; cyclopentasiloxane 6%, disteardimonium hectorite 0.5%; nanometer titanium dioxide 8%; titanium dioxide (CI 77891) 6%; CI 77492 (yellow iron oxide) 0.888%; CI 77491 (red iron oxide) 0.181%; CI 77499 (black iron oxide) 0.05%; styrene / DVB cross-linked copolymer 3%; dimethicone 6%; trimethylsiloxysilicate 6%; Water phase ingredients: butylene glycol 3%; glycerin 5%; xanthan gum 0.05%; water hectorite 0.05%; tromethamine 1.58%; phenyl benzimidazole sulfonic acid 3%; methylene bis-benzotriazolyl tetramethylbutylphenol 2.5; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0092] A water-in-oil sunscreen foundation cushion was prepared by emulsifying the same oil and water phases as in Example 20.

[0093] Comparative Example 4 A water-in-oil sunscreen foundation cushion was prepared by emulsifying the same oil and water phases as in Example 20. Oil phase ingredients: ethylhexyl methoxy cinnamate 6%; C9-12 alkyl 4%, ethylhexyl salicylate 3%; phenyl trimethicone 5%; diisostearyl malate 4%; distearyldimethyl ammonium hectorite 1%; lauryl PEG-9 polydimethylsiloxyethyl dimethicone 1%; cetyl PEG / PPG-10 / 1 polydimethylsiloxy silane 2.5%; polyglyceryl-2 dipolyhydroxystearate 0.5%; cyclopentasiloxane 6%; nano titanium dioxide 8%; titanium dioxide (CI 77891) 6%; CI 77492 (yellow iron oxide) 0.888%; CI 77491 (red iron oxide) 0.181%; CI 77499 (black iron oxide) 0.05%; styrene / DVB cross-linked copolymer 3%; dimethicone 6%; trimethylsiloxysilicate 6%; Water phase ingredients: butylene glycol 3%; sodium chloride 1%; glycerin 5%; tromethamine 1.58%; phenyl benzimidazole sulfonic acid 3%; methylene bis-benzotriazolyl tetramethylbutylphenol 2.5; p-hydroxyacetophenone 0.40%, 1,2-pentanediol 1.00%, and the balance deionized water.

[0094] A water-in-oil sunscreen foundation cushion was prepared by emulsifying the same oil and water phases as in Example 20.

[0095] Four samples of the water-in-oil sunscreen foundation cushions obtained in Examples 20-25 and Comparative Example 4 were placed in 4°C, 25°C, 45°C, and -18°C-50°C cycling conditions, respectively, for stability testing, and the appearance of the samples was observed at 1, 2, and 4 weeks. The results are shown in Table 4 and Figure 4 Figure 4 The comparative results of Example 25 and Comparative Example 4 after 4 weeks in -18°C-50°C cycling conditions are shown.

[0096] Table 4 Stability test results for the water-in-oil sunscreen foundation cushions obtained in Examples 20-25 and Comparative Example 4

[0097] ​The results show that the water phase composition of the water-in-oil sunscreen foundation air cushion does not contain sodium chloride, the oil phase composition is prepared into an oil gel, the water phase composition is prepared into a water gel, then the water gel is slowly put into the oil gel, and the water-in-oil emulsion formed by the method has better stability than the emulsion obtained by the comparative method between-18 ℃ and 50 ℃, has a long storage time, and has long-term stability.

[0098] In the scheme for preparing the water-in-oil sunscreen foundation air cushion, the dextrin palmitate in the oil gel can also be replaced by dextrin myristate, dextrin palmitate / ethylhexanoate, or stearyl inulin; the glyceryl behenate / eicosanoate can also be replaced by polyglyceryl-6 octastearate, glyceryl behenate, or glyceryl tri(behenate / isostearate / eicosadioate); the dimethylsilylated silica can be replaced by silica; and the styrene / butadiene copolymer can also be replaced by ethylene / propylene / styrene copolymer, butene / ethylene / styrene copolymer, styrene / isoprene copolymer, styrene / methylstyrene / indene copolymer, methylstyrene / ethylene toluene copolymer, hydrogenated (styrene / butadiene) copolymer, hydrogenated (styrene / isoprene) copolymer, hydrogenated (ethylene / propylene / styrene) copolymer, hydrogenated butene / ethylene / styrene copolymer, or hydrogenated (styrene / methylstyrene / indene) copolymer. In the water gel, the xanthan gum and the hydroxypropyl cellulose can be replaced by carob gum, cellulose gum, guar gum, sclerotium gum, gum arabic (tree) gum, sodium alginate, dehydrogenated xanthan gum, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl guar gum, agar, or tara gum; and the hectorite can be replaced by magnesium aluminum silicate, bentonite, or sodium magnesium lithium silicate.

[0099] In the scheme for preparing the water-in-oil sunscreen foundation air cushion, the types and proportions of the color adjusting materials can be controlled according to product requirements, so that products with different color values and color systems can be prepared.

[0100] All the documents mentioned in the present application are incorporated by reference in the present application, as if each document is individually incorporated by reference. In addition, it should be understood that, after reading the above teaching of the present application, those skilled in the art can make various modifications or amendments to the present application, and these equivalent forms also fall within the scope defined in the present application.

Claims

1. A method for improving the stability of a water-in-oil emulsion, characterized by, It comprises the following steps: S1, according to the oiliness of the oil phase added in the cosmetic product to be prepared, select the oil thickening agent matched with it, and form the oil gel by heating and physical stirring; S2, then mix the oil gel with other ingredients to be added in the oil phase in turn, and obtain the oil phase; S3, according to the water phase added in the cosmetic product to be prepared, select the water-soluble polymer thickening agent matched with it, and form the water gel by heating and physical stirring; S4, slowly add the water gel in step S3 to the oil phase obtained in step S2 by stirring, and cool to below 40 degrees.

2. The method of claim 1, wherein the water-in-oil emulsion is a microemulsion. The oil thickening agent is selected from one or more of silica, dimethylsilylated silica, ethyl cellulose, dextrin palmitate, dextrin myristate, dextrin palmitate / ethylhexanoate, stearyl inulin, styrene / butadiene copolymer, ethylene / propylene / styrene copolymer, butene / ethylene / styrene copolymer, styrene / isoprene copolymer, styrene / methylstyrene / indene copolymer, methylstyrene / ethylene toluene copolymer, hydrogenated (styrene / butadiene) copolymer, hydrogenated (styrene / isoprene) copolymer, hydrogenated (ethylene / propylene / styrene) copolymer, hydrogenated butene / ethylene / styrene copolymer, hydrogenated (styrene / methylstyrene / indene) copolymer, glyceryl behenate / eicosanoate, polyglyceryl-6 octastearate, glyceryl behenate, glyceryl tri(behenate / isostearate / eicosadioate), dibutyl lauroyl glutamide.

3. The method of claim 1, wherein the water-in-oil emulsion is a microemulsion. The water-soluble polymer thickening agent is selected from one or more of xanthan gum, carob gum, cellulose gum, guar gum, sordarium gum, gum arabic (tree) gum, sodium alginate, dehydrogenated xanthan gum, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl guar gum, agar, tara gum, succinoglycan, sodium hyaluronate, glucomannan, magnesium aluminum silicate, hectorite, bentonite, sodium magnesium lithium silicate, polyvinylpyrrolidone, sodium polyacrylate, carbomer, acrylates / C10-30 alkyl acrylate crosspolymer, polyacrylamide, polyacrylate-13, acrylamide / ammonium acrylate copolymer, polyacrylate crosspolymer-6, ammonium polyacryloyldimethyl taurate, sodium ammonium polyacryloyldimethyl taurate, hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, sodium acrylate / sodium acryloyldimethyl taurate copolymer, acrylates / beheneth-25 methacrylate copolymer, acrylates / steareth-20 itaconate copolymer.

4. The method of claim 1, wherein the water-in-oil emulsion is a microemulsion. The method steps further comprise the step of adding organic clay to the oil gel to form the oil phase.

5. The method of claim 1, wherein the method is characterized by: The method steps further comprise the step of adding inorganic salt to the water phase to form the water gel.

6. The method of claim 5, wherein the water-in-oil emulsion is stabilized by: The inorganic salt comprises sodium chloride, magnesium sulfate.

7. A method of increasing the stability of a water-in-oil emulsion according to any one of claims 1 to 6, characterised in that, The cosmetic product category comprises low-viscosity base makeup products, sunscreen products, and skin care creams.

8. The method of claim 7, wherein the water-in-oil emulsion is a microemulsion. The viscosity of the cosmetic product category is controlled by adjusting the stirring intensity and time after the water gel is added.

Images