A sunscreen emulsion system with skin feel and stability, applications and sunscreen products

Abstract

This invention belongs to the field of daily chemical products and discloses a sunscreen emulsion system that balances skin feel and stability. The sunscreen emulsion system is prepared from an alcohol phase, an oil phase, and an aqueous phase using a D-phase emulsification process. With a total weight of 100 wt%, the polyol content in the alcohol phase does not exceed 10 wt%, or the oil solvent content in the oil phase does not exceed 10 wt%. The emulsifier in the sunscreen emulsion system does not exceed 2 wt% and contains sodium stearoyl glutamate and an auxiliary emulsifier. The sodium stearoyl glutamate and the auxiliary emulsifier can form a liquid crystal in the sunscreen emulsion system. This system fully utilizes the advantages of D-phase emulsion systems. By reducing the amount of polyol and / or oil solvent, and by selecting specific emulsifiers such as sodium stearoyl glutamate and auxiliary emulsifiers that can cooperate with sodium stearoyl glutamate to form a liquid crystal, the system can remain stable under high and low temperature conditions. This invention also provides applications of this system and sunscreen products.

Description

Technical Field

[0001] This invention relates to the field of daily chemical products, and more particularly to a sunscreen emulsification system, its application, and sunscreen products that take into account both skin feel and stability. Background Technology

[0002] In the realm of daily sun protection, sunscreen lotion, as a core product for resisting UV damage and protecting skin health, directly determines its overall performance through the scientific and practical nature of its formulation system. Currently, most mainstream sunscreen lotions on the market employ two emulsion systems: water-in-oil (W / O) and oil-in-water (O / W). However, both of these systems have significant limitations, making it difficult to simultaneously meet multiple requirements such as high protective power, a pleasant skin feel, and long-term stability. Summary of the Invention

[0003] The purpose of this invention is to provide a sunscreen emulsification system that meets multiple requirements such as high protective power, good skin feel and long-term stability.

[0004] In addition, the present invention also provides applications of the system and sun protection products.

[0005] In the realm of daily sun protection, sunscreen lotion, as a core product for resisting UV damage and protecting skin health, directly determines its overall performance through the scientific and practical nature of its formulation system. Currently, most mainstream sunscreen lotions on the market employ two emulsion systems: water-in-oil (W / O) and oil-in-water (O / W). However, both of these systems have significant limitations, making it difficult to simultaneously meet multiple requirements such as high protective power, a pleasant skin feel, and long-term stability.

[0006] Water-in-oil (W / O) systems, with the oil phase as the continuous phase, are beneficial for the dispersion and film formation of oil-soluble sunscreens and have good water and sweat resistance. However, their inherent defects limit their application prospects: on the one hand, the high oil content results in a thick, sticky texture and an oily feel on the skin, which can easily cause a stuffy feeling and poor comfort, especially in high temperature and high humidity environments. On the other hand, in order to maintain the stability of the system, a large amount of emulsifier is often added, which may increase the risk of skin irritation. During long-term storage, problems such as oil seepage and structural instability may occur.

[0007] Oil-in-water (O / W) systems use an aqueous phase as the continuous phase, resulting in a relatively refreshing feel and easy application. However, they also have significant drawbacks: First, they have a weaker capacity to encapsulate oil-soluble sunscreens, which are prone to aggregation or precipitation, affecting the stability and uniformity of sun protection efficacy (SPF / PA value). Second, they have poor water and sweat resistance, easily being washed away by sweat or water, leading to damage to the sunscreen film and making it difficult to maintain the protective effect for long. In addition, increasing the oil phase content to achieve a high SPF can easily lead to the loss of the system's inherent refreshing advantage and may exacerbate emulsification instability.

[0008] Alpha gelation is a special oil-in-water emulsification method that uses a specific ratio of higher fatty alcohols and surfactants to form an α-gel structure with a hexagonal crystal system. This structure consists of a bilayer in which the higher alcohols and surfactants are arranged in a regular 3:1 molecular ratio, forming an associative compound with high occlusion and excellent water retention.

[0009] Some literature reveals, through underlying logic, some application variations of α-gelling, as follows: The master's thesis, "Preparation and Performance Study of Liquid Crystal Multifunctional Sunscreen Emulsion," by Chen Yonglu, states on pages 17-18 that in oil-in-water systems, sunscreen agents constitute the majority of the oil phase. To form a good liquid crystal system, a single emulsifier is insufficient to completely emulsify the oil, requiring the addition of an emulsifier. The fundamental factor contributing to the emulsification instability of oil-in-water skincare systems is the increased particle size due to flocculation and contact between droplets. The liquid crystal at the oil-water interface can only partially prevent droplet aggregation and is insufficient to improve flocculation. Therefore, the addition of fatty alcohols is necessary to form more liquid crystal units and further stabilize the liquid crystal phase. In this system, a combination of glycerol (8 wt%) and cetyl alcohol (2 wt%) was chosen. The liquid crystal emulsifier used was sodium stearoyl glutamate (3 wt%), and the liquid crystal phase was a weak lamellar liquid crystal.

[0010] Patent application CN106604714B, entitled "α-gel intermediate composition and preparation method of O / W emulsified cosmetic containing α-gel using the composition", further explains the α-gel intermediate in more detail. In its Example 11 (sunscreen) formulation, it uses more than 4 wt% of long-chain fatty alcohol, 6 wt% of dipropylene glycol, 5 wt% of 1,3-butanediol, and 1.2 wt% of sodium N-stearoylmethyl taurate.

[0011] As can be seen from the two documents mentioned above, the liquid crystal forming ability of stearoyl emulsifiers can be enhanced by increasing the amount of long-chain fatty alcohols and polyols. At the same time, the conversion of the traditional oil-in-water system to the α-gel phase oil-in-water system is realized by increasing the amount of long-chain fatty alcohols.

[0012] However, regardless of the type of oil-in-water system, an unavoidable issue is the use of long-chain fatty alcohols and polyols, as well as the conversion of the specific form of the oil-in-water system through increased dosage. Long-chain fatty alcohols carry a potential acne-causing risk; for users with abnormal sebum metabolism, their use can worsen clogged pores, leading to oily skin or breakouts.

[0013] Therefore, one of the objectives of this invention is to avoid the use of long-chain fatty alcohols.

[0014] Meanwhile, in the literature "Preparation and Performance Study of a Sunscreen Emulsion Based on Liquid Crystal Emulsifier Technology", by Jia Kai et al., Biochemical Engineering, Vol. 9, No. 4, August 2023, the preparation of an oil-in-water sunscreen is disclosed. Sucrose polystearate / cetyl palmitate, cetearyl glucoside / cetearyl alcohol, and glyceryl stearate / PEG-100 stearate are used as the main emulsifiers for forming liquid crystals, and sodium stearoyl glutamate is used as a co-emulsifier. Furthermore, their research found that as the amount of the main emulsifier decreases, the liquid crystal effect gradually decreases.

[0015] Therefore, based on the above literature analysis, we can roughly draw the following conclusions: 1. For sunscreen products with a high oil content, maintaining stability is a difficult issue to control when forming an oil-in-water emulsion system; 2. Formation of a liquid crystal phase can improve the stability of an oil-in-water system; 3. The selection of long-chain fatty alcohols, emulsifiers, and co-emulsifiers is crucial for liquid crystal formation; 4. Long-chain fatty alcohols and emulsifiers need to be maintained at high levels to ensure stable liquid crystal formation.

[0016] However, when sunscreen products need to pay extra attention to both skin feel and stability, the development of the formula undoubtedly becomes more difficult. For improving skin feel, the following factors are crucial: the amount of emulsifier, the amount of alcohol, and the amount of oil. The less of these three, the better the skin feel. However, paradoxically, increasing the amount of emulsifier and alcohol can improve product stability, while a moderate increase in the amount of solvent in the oil also contributes to stability.

[0017] Therefore, the problem to be solved by this application is: how to maintain the stability of the system and maintain a better skin feel while avoiding the use of excessive emulsifiers and long-chain fatty alcohols.

[0018] The sunscreen emulsification system provided by this invention fully utilizes the advantages of the D-phase emulsion system. By selecting specific emulsifiers such as sodium stearoyl glutamate and auxiliary emulsifiers that can cooperate with sodium stearoyl glutamate to form liquid crystals, the system can remain stable under high and low temperature conditions when reducing polyols and / or oily solvents.

[0019] The specific solution of the present invention is as follows: A sunscreen emulsification system that balances skin feel and stability, wherein the sunscreen emulsification system is prepared by a D-phase emulsification process from an alcohol phase, an oil phase, and an aqueous phase. With a total weight of 100 wt% for the sunscreen emulsification system, the content of polyols in the alcohol phase does not exceed 10 wt% or the content of oily solvents in the oil phase does not exceed 10 wt%; The amount of emulsifier in the sunscreen emulsification system does not exceed 2 wt% and contains sodium stearoyl glutamate and auxiliary emulsifiers; the sodium stearoyl glutamate and auxiliary emulsifiers can form liquid crystals in the sunscreen emulsification system.

[0020] D-phase emulsification is an advanced emulsification technology proposed by Sagitani et al. in 1983 based on the PIC emulsification method (phase transition concentration method). It aims to produce fine nanoemulsions. The core of this method lies in first forming a ternary gel phase (D-phase) composed of surfactants, polyols, and water. Then, an oil phase is slowly added to this gel phase, along with an aqueous phase to dilute it, ultimately forming an extremely fine and stable emulsion. Emulsions prepared using this technique are characterized by small particle size, narrow distribution, extremely high stability, and a refreshing, non-greasy feel.

[0021] For information on the application of D-phase emulsification in sunscreen products, please refer to "Research on the Application of D-phase Emulsification in Cosmetics," published on October 18, 2025, in Fashion & Beauty | Cosmetics Science Popularization. The study on the related mechanisms of D-phase emulsification explains that research data shows that controlling the polyol content between 10wt% and 30wt% can optimize the gel network strength (for a related case, please refer to patent application CN120753981A, entitled "A Physicochemically Combined Sunscreen Aqueous Dispersion and Its Preparation Method and Application"). In its section on industrialization challenges and countermeasures, it emphasizes the need to prevent the formation of cubic / hexagonal phases.

[0022] The essential difference between D-phase emulsification and α-gel phase is whether they contain long-chain fatty alcohols and whether they form a hexagonal crystal system. D-phase emulsification generally avoids the formation of cubic / hexagonal phases, while α-gel phase requires the promotion of hexagonal phase formation.

[0023] In this invention, to achieve the desired skin feel, the amounts of emulsifier and polyol need to be kept as low as possible; however, to improve gel network strength and high / low temperature stability, the amounts of emulsifier and polyol need to be increased. To solve this problem, this invention screens surfactants, selecting sodium stearoyl glutamate as the main surfactant, and then screens auxiliary surfactants that can form a liquid crystal phase with sodium stearoyl glutamate at extremely low concentrations. The combination of these two surfactants satisfies two requirements: 1. It can form a gel phase; 2. It can form a liquid crystal structure in a water-diluted emulsion system. After meeting these requirements, we surprisingly found that the contribution of polyol to network strength is significantly reduced; that is, the amount of polyol can be reduced to below 10 wt% while still maintaining good high / low temperature stability.

[0024] Furthermore, by increasing the amount of oily solvents or polyols in the oil phase, we found that the emulsion system, which was originally unstable, could become stable. This indicates that the amount of oily solvents and polyols used is not only related to the skin feel, but also closely related to the emulsifying effect of the emulsifier. In other words, reducing the amount of oily solvents and polyols will reduce the stability of the D-phase emulsion system. Therefore, selecting the emulsifier for the D-phase emulsion system is a core point in project development.

[0025] In essence, in the system of this invention, polyols primarily function as co-emulsifiers and phase behavior modifiers. Specifically, they can insert themselves between surfactant molecules, weakening the interaction of hydrophobic chains and resulting in a more uniform distribution of the surfactant in the aqueous solution. Simultaneously, they alter the solubility of oil in the surfactant phase and the miscibility of the surfactant with water. This contributes to the formation of a more stable emulsion structure; therefore, more polyols stabilize an otherwise unstable system. Conversely, the increased use of oily solvents, due to their good fluidity and lower polarity, allows for more uniform dispersion of oil-soluble sunscreen agents, contributing to the formation of smaller oily droplets and reducing the emulsifying performance requirements of the emulsifier. In contrast, less polyol and oily solvent will reduce the stability of most of the originally stable D-phase emulsion system. In summary, by optimizing the composition of the emulsifier, the present invention makes it possible to reduce the amount of oily solvent and polyol used in the D-phase emulsion system.

[0026] Meanwhile, the D-phase emulsification system naturally possesses a refreshing and non-greasy skin feel, finer emulsion particles, and a narrower particle size distribution, giving it a more significant advantage in skin feel and stability compared to traditional water-in-oil sunscreens and α-gel system sunscreens. The emulsification system of this invention has excellent skin feel, low irritation, good high and low temperature stability, and good sun protection performance.

[0027] It should be noted that the D-phase emulsification process in this invention generally includes three steps: Step 1: Prepare an alcohol phase containing an emulsifier; Step 2: Add the alcohol phase to the oil phase to form a gel. Step 3: Dilute the above gel phase with water to form a nanoemulsion.

[0028] More preferably, the process specifically includes: Step 1: Disperse the emulsifier in the alcohol phase in water at a low speed at 70~80℃, then add the remaining alcohol phase components, stir evenly, and keep the temperature constant at 70~80℃; Step 2: Mix the oil-soluble sunscreen agent in the oil phase evenly, heat to 70~80℃ until completely dissolved, add the remaining components of the oil phase and stir evenly, heat to 70~80℃ until evenly dissolved, and maintain the temperature at 70~80℃. Step 3: Under high-speed stirring of the alcohol phase, slowly drop the oil phase, emulsify at 800~1200 rpm for 20~40 min, and homogenize at 7200~8600 rpm for 5~8 min; Step 4: After dissolving or stirring the water-soluble sunscreen agent in the aqueous phase, adjust the pH to 7.0~7.5 using a pH adjuster, and maintain a constant temperature of 70~80℃; Step 5: The mixture obtained in Step 3 is slowly added dropwise to the aqueous phase under high-speed stirring, emulsified at 1600-2000 rpm for 25-30 min, and homogenized at 8400 rpm for 5-8 min;

[0029] After cooling to room temperature, adjust the pH to 7.0~7.5 to obtain the D-phase emulsified sunscreen.

[0030] In the above-mentioned sunscreen emulsification system, the sunscreen agent in the sunscreen emulsification system includes oil-soluble sunscreen agents; The oil-soluble sunscreen agent is one or more of the following: octocrylene, ethylhexyl methoxycinnamate, humosalidinyl ester, isooctyl salicylate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoylhexyl benzoate, ethylhexyl triazine ketone, and butyl methoxydibenzoylmethane. In practical applications, a combination of multiple oil-soluble sunscreens is generally used to achieve synergistic protection against different wavelengths, which significantly helps to improve the protection against UVA and UVB. In addition, when combining oil-soluble sunscreens, the factor of skin penetration is also considered. Therefore, oil-soluble sunscreens with larger molecular weights and those with smaller molecular weights are often combined to prevent the smaller molecular weight oil-soluble sunscreens from penetrating into the skin.

[0031] In this invention, a more preferred oil-soluble sunscreen agent is a combination of octocrylene, ethylhexyl methoxycinnamate, humosasulfate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoyl hexyl benzoate, and ethylhexyl triazine ketone.

[0032] The amount of the oil-soluble sunscreen agent is 15-19 wt%. Preferably, the amount of the oil-soluble sunscreen agent is 15 wt%, 16 wt%, 17 wt%, 18 wt%, or 19 wt%.

[0033] In the above-mentioned sunscreen emulsification system, the sunscreen agent further includes water-soluble sunscreen agents and / or inorganic sunscreen agents; The amount of the water-soluble sunscreen agent is 0~8wt%; the amount of the inorganic sunscreen agent is 0~10wt%; wherein the amount of the water-soluble sunscreen agent and the amount of the inorganic sunscreen agent are not both 0; Preferably, the amount of the water-soluble sunscreen agent is 2-8 wt%; the amount of the inorganic sunscreen agent is 2-8 wt%. The water-soluble sunscreen agent is one or more of the following: terephthalic methylene dicamphor sulfonic acid, methylene bis-benzotriazolyl tetramethyl butylphenol, phenylbenzimidazole sulfonic acid, and disodium phenyl dibenzimidazole tetrasulfonate. More preferably, the water-soluble sunscreen agent is a composition of benzo[2-methyl]camphorsulfonic acid and methylene bis-benzotriazolyltetramethylbutylphenol.

[0034] The inorganic sunscreen agent is nano-titanium dioxide and / or nano-zinc oxide powder.

[0035] In the above-mentioned sunscreen emulsification system, the alcohol phase contains the emulsifier, 6-10 wt% of polyol and 5-10 wt% of water.

[0036] Preferably, the polyol is glycerol and / or butanediol.

[0037] In the above-mentioned sunscreen emulsification system, the oil phase contains an oil-soluble sunscreen agent and 7-10 wt% oily solvent; the oil phase also contains one or more combinations of skin feel modifiers, film-forming agents, and thickeners.

[0038] Any commonly used skin feel modifier, film-forming agent, or thickener in the art can be applied to this invention. More specifically, the skin feel modifier is one or any combination of polymethylsilsesquioxane, vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinked polymer; the film-forming agent is trimethylsiloxysilicate; and the thickener is one or any combination of stearyl alcohol, cetearyl alcohol, and behenyl alcohol. The preferred amount of the skin feel modifier is 2-6 wt%, the preferred amount of the film-forming agent is 1-2 wt%, and the preferred amount of the thickener is 1-2 wt%. In some embodiments of the present invention, the preferred amounts of the skin feel modifier are 2 wt%, 3 wt%, 4 wt%, 5 wt%, and 6 wt%; and the preferred amounts of the film-forming agent are 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, and 2.0 wt%. In the above-mentioned sunscreen emulsification system, the aqueous phase can generally be only deionized water. Preferably, it can also contain a pH adjuster. Preferably, the pH adjuster is one or any combination of sodium hydroxide, triethanolamine, tromethamine and arginine. In the above-mentioned sunscreen emulsification system, the oily solvent includes lauroyl sarcosine isopropyl ester; the oily solvent also includes one or more combinations of squalane, caprylic / capric triglyceride, ethylhexyl palmitate, octyl polymethylsiloxane, and methyl polytrimethylsiloxane; the amount of lauroyl sarcosine isopropyl ester is not less than 2 wt%, preferably 2 to 4 wt%.

[0039] The main reason for choosing lauroyl sarcosine isopropyl ester as an essential component of oil-soluble sunscreens in this invention is that lauroyl sarcosine isopropyl ester can more effectively dissolve oil-soluble sunscreens, especially under low-temperature conditions, which can effectively prevent the precipitation of organic sunscreens.

[0040] Furthermore, experiments have shown that lauroyl sarcosine isopropyl ester plays a significant role in improving sun protection performance in the emulsification system of this invention.

[0041] In the above-mentioned sunscreen emulsification system, the amount of sodium stearoyl glutamate is 0.5~1wt%; the auxiliary emulsifier is potassium cetyl phosphate and / or cetearyl glucoside.

[0042] The preferred emulsifier of the present invention, sodium stearoyl glutamate, has the advantages of being mild, low in irritation, and having high emulsification efficiency. Any of the above-mentioned auxiliary emulsifiers can work together with sodium stearoyl glutamate to produce a more dense liquid crystal structure.

[0043] In a preferred embodiment of the present invention, the amount of the auxiliary emulsifier is 0.5~1wt%.

[0044] In some embodiments of the present invention, the amount of sodium stearoyl glutamate used is 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, and 1.0wt%; the amount of auxiliary emulsifier used is 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, and 1.0wt%.

[0045] In addition, the present invention also discloses the use of the sunscreen emulsification system described above in the preparation of sunscreen products.

[0046] Finally, the present invention also discloses a sunscreen product containing the sunscreen emulsification system described above; the sunscreen product is a sunscreen lotion.

[0047] This application has at least the following beneficial effects: When reducing polyols and / or oily solvents, this invention can maintain the stability of the system under high and low temperature conditions by selecting specific emulsifiers such as sodium stearoyl glutamate and auxiliary emulsifiers that can cooperate with sodium stearoyl glutamate to form liquid crystals. At the same time, the emulsion system of this invention also has advantages such as good skin feel, low irritation, and excellent sun protection effect. Attached Figure Description

[0048] Figure 1 A liquid crystal microscope photograph of Example 1; Figure 2 A liquid crystal microscope photograph of Example 2; Figure 3 This is a liquid crystal microscope photograph of Example 3. Detailed Implementation

[0049] The present invention will now be clearly and completely described in conjunction with embodiments thereof. It should be noted that, unless specific conditions are specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0050] Example 1 This implementation provides a phase D emulsified sunscreen, whose ingredients, by weight percentage, include: 0.5 wt% sodium stearoyl glutamate, 1 wt% cetearyl glucoside, and 6 wt%... 1,3-Butanediol, 17.5 wt% oil-soluble sunscreen (composed of 1.5 wt% octocrylene, 8 wt% ethylhexyl methoxycinnamate, 3 wt% humosasulfate, 2 wt% bis-ethylhexyloxyphenol methoxyphenyl triazine, 2 wt% diethylamino hydroxybenzoyl hexyl benzoate, 1 wt% ethylhexyl triazine ketone), 8 wt% oil-based solvent (2 wt% lauroyl sarcosinate isopropyl ester, 3 wt% octyl polymethylsiloxane, 3 wt% methyl polytrimethylsiloxane), 1 wt% cetearyl alcohol (thickener), 2 wt% trimethylsiloxysilicate (film-forming agent), 6 wt% water-soluble sunscreen (4 wt% terephthalimide dicamphor sulfonic acid, 2 wt% methylene bis-benzotriazolyl tetramethyl butylphenol), 1 wt% triethanolamine (pH adjuster), and the balance being water.

[0051] The preparation method of D-phase emulsion includes the following steps: Phase D emulsified sunscreen emulsion includes phase A, phase B and phase C. Phase A includes emulsifier, polyol and 8 wt% water; phase B includes oil-soluble sunscreen agent, oil-based solvent, film-forming agent and thickener; phase C includes water-soluble sunscreen agent, pH adjuster and water as the balance. The "balance" mentioned here refers to the total weight of the system being 100 wt% after adding water.

[0052] (1) Disperse the emulsifier in phase A in water at a low stirring speed of 300 rpm at 75°C, then add the remaining phase A components, stir evenly, and keep the temperature constant at 75°C. (2) Mix the oil-soluble sunscreen agent in phase B evenly, heat to 75°C until completely dissolved, add the remaining components of phase B and stir evenly, heat to 75°C until evenly dissolved, and keep the temperature at 75°C. (3) Phase A was slowly added dropwise at a high speed of 1000 rpm for 10 min, followed by emulsification at 1000 rpm for 30 min and homogenization at 8000 rpm for 6 min. (4) After dissolving and stirring the C-phase water-soluble sunscreen agent evenly, adjust the pH to 7.0~7.5 using a pH adjuster and keep it at a constant temperature of 75℃; (5) In step (3), the C phase is slowly added dropwise under high-speed stirring for 15 min, emulsified at 1800 rpm for 30 min, and homogenized at 8400 rpm for 5 min; (6) After cooling to room temperature, adjust the pH to 7.0~7.5 to obtain the D-phase emulsified sunscreen.

[0053] Example 2 This embodiment provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 1 wt% cetyl phosphate potassium is used instead of 1 wt% cetearyl glucoside, while the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0054] Example 3 This embodiment provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 1 wt% sodium stearoyl glutamate is used instead of 0.5 wt% sodium stearoyl glutamate, while the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0055] Example 4 This embodiment provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 1 wt% sodium stearoyl glutamate and 1 wt% potassium cetyl phosphate replace 0.5 wt% sodium stearoyl glutamate and 1 wt% cetearyl glucoside, while the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0056] Example 5 This embodiment provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 20 wt% of an oil-soluble sunscreen agent (composed of 2 wt% octocrylene, 8 wt% ethylhexyl methoxycinnamate, 3 wt% homosalate, 3 wt% bis-ethylhexyloxyphenol methoxyphenyl triazine, 3 wt% diethylaminohydroxybenzoyl hexyl benzoate, and 1 wt% ethylhexyl triazine ketone) replaces 17.5 wt% of an oil-soluble sunscreen agent (composed of 1.5 wt% octocrylene, 8 wt% ethylhexyl methoxycinnamate, 3 wt% homosalate, 2 wt% bis-ethylhexyloxyphenol methoxyphenyl triazine, 2 wt% diethylaminohydroxybenzoyl hexyl benzoate, and 1 wt% ethylhexyl triazine ketone), while the remaining components remain unchanged. The preparation method is the same as in Example 1.

[0057] Example 6 This embodiment provides a D-phase emulsified sunscreen, which differs from Example 5 only in that 1 wt% sodium stearoyl glutamate replaces 0.5 wt% sodium stearoyl glutamate in the composition, while the remaining components remain unchanged. The preparation method is the same as in Example 1.

[0058] Example 7 This embodiment provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 10wt% of the oily solvent (2wt% lauroyl sarcosinate, 3wt% ethylhexyl palmitate, 2wt% caprylic / capric triglyceride, 3wt% methyl polytrimethylsiloxane) replaces 8wt% of the oily solvent (2wt% lauroyl sarcosinate, 3wt% octyl polymethylsiloxane, 3wt% methyl polytrimethylsiloxane), while the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0059] Example 8 This embodiment provides a D-phase emulsified sunscreen, which differs from Embodiment 1 only in that the oil solvent is: 4wt% lauroyl sarcosine isopropyl ester, 2wt% octyl polymethylsiloxane, and 2wt% methyl polytrimethylsiloxane.

[0060] Example 9 This embodiment provides a D-phase emulsified sunscreen, which differs from Embodiment 1 only in that: Phase A includes emulsifier, polyol, and 10wt% water; The emulsifiers are: 0.8 wt% sodium stearoyl glutamate and 0.8 wt% cetearyl glucoside; The polyol is glycerol, and the amount of glycerol used is 6 wt%.

[0061] Example 10 This embodiment provides a D-phase emulsified sunscreen, which differs from Embodiment 1 only in that: Phase A includes emulsifier, polyol, and 5wt% water; The emulsifiers are: 1 wt% sodium stearoyl glutamate and 0.5 wt% potassium cetyl phosphate; The polyol is butanediol, and the amount of butanediol used is 10 wt%.

[0062] Example 11 This embodiment provides a D-phase emulsified sunscreen emulsion, which differs from Embodiment 1 only in the composition of the sunscreen agent and the oily solvent; In this embodiment, water-soluble sunscreens are not used; instead, inorganic sunscreens are used instead. Specifically: The amount of oil-soluble sunscreen agent used is 15wt%; it is specifically composed of 1.5wt% octocrylene, 6.5wt% ethylhexyl methoxycinnamate, 2wt% homosalate, 2wt% bis-ethylhexyloxyphenol methoxyphenyl triazine, 2wt% diethylamino hydroxybenzoyl hexyl benzoate, and 1wt% ethylhexyl triazine ketone. 8wt% oily solvent (3wt% lauroyl sarcosine isopropyl ester, 2wt% octyl polymethylsiloxane, 3wt% methyl polytrimethylsiloxane); The inorganic sunscreen agent is nano-titanium dioxide, and the amount of nano-titanium dioxide used is 3 wt%. During the preparation of the sunscreen, nano-titanium dioxide is dispersed into phase B.

[0063] The reduction in amount due to the lack of water-soluble sunscreen agents and the reduction due to the amount of oil-soluble sunscreen agents used are made up by deionized water.

[0064] The preparation method is the same as in Example 1.

[0065] Example 12 This embodiment provides a D-phase emulsified sunscreen emulsion, which differs from Embodiment 1 only in the composition of the sunscreen agent and the oily solvent; In this embodiment, only oil-soluble sunscreen agents are used, and the amount of oil-soluble sunscreen agents is 20 wt%, and their specific composition is as follows: 2wt% Octocrylene, 8wt% Ethylhexyl methoxycinnamate, 3wt% Humosalate, 3wt% Bis-ethylhexyloxyphenol methoxyphenyl triazine, 3wt% Diethylaminohydroxybenzoyl hexyl benzoate, 1wt% Ethylhexyl triazine ketone.

[0066] 10wt% oily solvent (4wt% lauroyl sarcosine isopropyl ester, 3wt% octyl polymethylsiloxane, 3wt% methyl polytrimethylsiloxane); The reduction in the amount of water-soluble sunscreen due to its absence is compensated by deionized water.

[0067] The preparation method is the same as in Example 1.

[0068] Example 13 This embodiment provides a D-phase emulsified sunscreen, which differs from Embodiment 1 only in the composition of the sunscreen agent; In this embodiment, the sunscreen agent is composed of water-soluble sunscreen agent, oil-soluble sunscreen agent and inorganic sunscreen agent; The total amount of oil-soluble sunscreen agents is 17wt%, and its specific composition is: 1.5wt% octocrylene, 8wt% ethylhexyl methoxycinnamate, 3wt% humosasulfate, 1.5wt% bis-ethylhexyloxyphenol methoxyphenyl triazine, 2wt% diethylamino hydroxybenzoyl hexyl benzoate, and 1wt% ethylhexyl triazine ketone.

[0069] The inorganic sunscreen agent is nano-zinc oxide, and its dosage is 1.5 wt%. The remaining components remain unchanged.

[0070] During the preparation of the sunscreen, nano-titanium dioxide is dispersed into phase B.

[0071] The preparation method is the same as in Example 1.

[0072] Comparative Example 1 This case provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, only 1 wt% sodium stearoyl glutamate is used as the emulsifier, while the other components remain unchanged, and the preparation method is the same as in Example 1.

[0073] Comparative Example 2 This case provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, only 2wt% sodium stearoyl glutamate is used as the emulsifier, while the other components remain unchanged, and the preparation method is the same as in Example 1.

[0074] Comparative Example 3 This case provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: 2 wt% squalane is used instead of 2 wt% lauroyl sarcosine isopropyl ester in the composition, while the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0075] Comparative Example 4 This case provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 1 wt% potassium cetyl phosphate and 1 wt% cetearyl glucoside replace 0.5 wt% sodium stearoyl glutamate and 1 wt% cetearyl glucoside, while the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0076] Comparative Example 5 This case provides a D-phase emulsified sunscreen, which differs from Example 8 only in that 2 wt% squalane replaces 2 wt% lauroyl sarcosine isopropyl ester in the composition, while the remaining components remain unchanged. The preparation method is the same as in Example 1.

[0077] Comparative Example 6 This case provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 3wt% sodium stearoyl glutamate and 3wt% cetearyl glucoside replace 0.5wt% sodium stearoyl glutamate and 1wt% cetearyl glucoside, while the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0078] Comparative Example 7 This case provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 1 wt% potassium cetyl phosphate and 1 wt% cetearyl glucoside replace 0.5 wt% sodium stearoyl glutamate and 1 wt% cetearyl glucoside, and the content of butylene glycol is increased to 15 wt%; the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0079] Comparative Example 8 This case provides a D-phase emulsified sunscreen, which differs from Example 1 only in that: in the composition, 1 wt% potassium cetyl phosphate and 1 wt% cetearyl glucoside replace 0.5 wt% sodium stearoyl glutamate and 1 wt% cetearyl glucoside; at the same time, the content of oily solvent is adjusted to 16 wt%, specifically including 4 wt% lauroyl sarcosine isopropyl ester, 6 wt% octyl polymethylsiloxane, and 6 wt% methyl polytrimethylsiloxane; the remaining components remain unchanged, and the preparation method is the same as in Example 1.

[0080] Comparative Example 9 This case study provides an α-gel emulsification system, the specific preparation method of which is as follows: Step 1: Mix 1.5 wt% sodium stearoyl glutamate, 3.5 wt% docosanool, 1 wt% octadecanool, 5.5 wt% 1,4-butanediol and 4 wt% water to form a bicontinuous microemulsion. Step 2: Add 17.5 wt% of oil-soluble sunscreen agent (composed of 1.5 wt% octocrylene, 8 wt% ethylhexyl methoxycinnamate, 3 wt% humosasulfate, 2 wt% bis-ethylhexyloxyphenol methoxyphenyl triazine, 2 wt% diethylamino hydroxybenzoyl hexyl benzoate, and 1 wt% ethylhexyl triazine ketone), 8 wt% oil-based solvent (2 wt% lauroyl sarcosinate isopropyl ester, 3 wt% octyl polymethylsiloxane, and 3 wt% methyl polytrimethylsiloxane), 1 wt% cetearyl alcohol (thickener), and 2 wt% trimethylsiloxysilicate (film-forming agent) to Step 1 and homogenize (8000 rpm for 6 min). Step 3: After mixing 6 wt% of water-soluble sunscreen agent (4 wt% terephthalic dicamphor sulfonic acid, 2 wt% methylene bis-benzotriazolyl tetramethyl butylphenol), 1 wt% triethanolamine (pH adjuster) and the remaining water, slowly add it to the system in Step 2 and homogenize (homogenize at 8400 rpm for 5 min).

[0081] Comparative Example 10 This case study provides an oil-in-water emulsion system, whose raw materials, by mass percentage, include: Oil phase: 17.5wt% oil-soluble sunscreen agent (composed of 1.5wt% octocrylene, 8wt% ethylhexyl methoxycinnamate, 3wt% humosasulfate, 2wt% bis-ethylhexyloxyphenol methoxyphenyl triazine, 2wt% diethylamino hydroxybenzoyl hexyl benzoate, 1wt% ethylhexyl triazine ketone), 8wt% oil solvent (2wt% lauroyl sarcosinate isopropyl ester, 3wt% octyl polymethylsiloxane, 3wt% methyl polytrimethylsiloxane), 1wt% cetearyl alcohol (thickener), 2wt% trimethylsiloxysilicate (film-forming agent); Aqueous phase: 0.5wt% sodium stearoyl glutamate, 1wt% cetearyl glucoside, 6wt% 1,3-butanediol; 6wt% water-soluble sunscreen (4wt% terephthalimide dicamphor sulfonic acid, 2wt% methylene bis-benzotriazolyl tetramethyl butylphenol), 1wt% triethanolamine (pH adjuster) and the balance water (added to a total weight of 100wt%).

[0082] The preparation method of the oil-in-water emulsion system is as follows: The aqueous phase and oil phase were heated to 75°C respectively. The oil phase was added to the aqueous phase while stirring. After the oil phase was added, the mixture was homogenized at 8000 rpm for 6 minutes. After homogenization, the mixture was allowed to cool naturally to room temperature.

[0083] Unless otherwise specified, all wt% in this invention refers to weight percentage; the wt% in this invention is based on the total weight of the sunscreen lotion as 100wt%.

[0084] Test methods and equipment: Viscosity test: The viscosity was tested using a Brookfield viscometer with rotor No. 5 and rotation speed No. 20. The results are shown in Table 1.

[0085] Stability test Centrifugation stability test: Use a 15ml centrifuge tube, add 12g of D-phase emulsified sunscreen, and centrifuge at 3000rpm for 30min.

[0086] High temperature stability test: 12g of D-phase emulsified sunscreen lotion was taken into a 15ml centrifuge tube and sealed and placed at 48℃ for 30 days.

[0087] Low temperature stability test: Using a 15ml centrifuge tube, 12g of D-phase emulsified sunscreen lotion was taken and sealed at -18℃ for 30 days.

[0088] Observe whether the sample shows phenomena such as layering, precipitation, or exudation. If these phenomena occur, it indicates that the stability of the D phase sunscreen is poor. If the appearance is inconsistent with that before the test, it indicates that the sunscreen sample fails the stability test, and the phenomenon of failure is recorded. Otherwise, it indicates that the sunscreen sample is relatively stable and can pass the stability test, and is recorded as passed. The results are shown in Table 1.

[0089] Sunscreen performance test Sunscreen performance testing was conducted using a Labsphere UV-2000S cosmetic UV transmittance tester. The testing method followed ISO 24443:2021, the in vitro sunscreen test method. The samples prepared in each example and comparative example were evenly coated on a PMMA plate, and the in vitro SPF and PA values ​​were tested using the Labsphere UV-2000S. Each formulation sample was tested three times and the average value was taken.

[0090] The test method for the liquid crystal structure of sunscreen lotion is polarized light microscopy.

[0091] Table 1 Basic Performance Example 1 7350 pass pass pass 53.13 26.78 yes Example 2 8500 pass pass pass 54.20 27.78 yes Example 3 8350 pass pass pass 55.01 28.46 yes Example 4 8930 pass pass pass 53.45 27.21 yes Example 5 6771 pass pass pass 60.89 31.33 yes Example 6 7120 pass pass pass 59.71 30.63 yes Example 7 5500 pass pass pass 52.47 24.65 yes Example 8 7476 pass pass pass 56.08 29.41 yes Example 9 7547 pass pass pass 52.92 25.66 yes Example 10 7892 pass pass pass 53.41 27.09 yes Example 11 7853 pass pass pass 72.51 37.34 yes Example 12 6253 pass pass pass 42.69 14.73 yes Example 13 7461 pass pass pass 67.37 34.69 yes Comparative Example 1 7877 pass Layering pass 51.27 22.78 no Comparative Example 2 8341 pass Layering pass 53.91 27.24 no Comparative Example 3 7152 pass pass Sunscreen agent precipitation 43.28 15.33 yes Comparative Example 4 5170 Layering Layering Layering 45.32 17.75 yes Comparative Example 5 7471 pass pass Sunscreen agent precipitation 46.23 18.33 yes Comparative Example 6 9020 pass pass pass 51.40 23.12 yes Comparative Example 7 7083 pass pass pass 52.66 23.78 yes Comparative Example 8 5744 pass pass pass 53.79 27.42 yes Comparative Example 9 8170 pass pass Sunscreen agent precipitation 44.38 16.35 yes Comparative Example 10 2105 Layering Layering Layering 42.90 13.86 yes

[0092] The liquid crystal structures of Examples 1 to 3 are visible. Figures 1 to 3 .

[0093] Results analysis: 1. As can be seen from Examples 1 to 4, as well as Examples 9 and 10, the emulsion systems obtained by appropriately adjusting the surfactants in Examples 1 to 4 all exhibit good stability; 2. As can be seen from the comparison of Examples 5 and 6 with Examples 1 and 3, the emulsion system of the present invention can carry up to 20 wt% of oil-soluble sunscreen agents while maintaining stability. As can be seen from the comparison of Examples 7, 1, 8, Comparative Examples 3 and 5, the emulsion system of the present invention can exist stably when the content of oily solvent is not higher than 10 wt%. At the same time, Comparative Examples 3 and 5 can further prove that the high solubility of lauroyl sarcosine isopropyl ester for oil-soluble sunscreen agents is an important factor in preventing partial separation of oil-soluble sunscreen agents.

[0094] 3. Comparative Examples 6, 7, and 8 show that the system can maintain stability when the emulsifier, polyol and emulsifier are increased, or oil solvent and emulsifier are adjusted. This indicates that the stability of the system is closely related to the amount of emulsifier, polyol and oil solvent used. However, the above three factors do not improve the skin feel.

[0095] 4. In each embodiment, under the premise of equal sunscreen agent dosage, the sun protection performance did not change significantly; among the comparative examples, the differences in sun protection performance were quite significant. Among them, the PA values ​​of Comparative Example 1 and Comparative Example 2 increased significantly compared to other comparative examples, which exceeded the expectations of this project development; the SPF and PA values ​​of Comparative Example 3, Comparative Example 4, and Comparative Example 5 all decreased significantly, indicating that lauroyl sarcosine isopropyl ester not only helps to dissolve and release oil-soluble sunscreen agents, but also helps to improve their sun protection effectiveness. At the same time, it also proves that sodium stearoyl glutamate has a natural advantage in sun protection performance when applied to the D-phase emulsion system, which is superior to other emulsifiers or combinations of emulsifiers. It can even be considered that in the D-phase emulsion system, compared with using sodium stearoyl glutamate alone, the improvement in sun protection by using sodium stearoyl glutamate to form a liquid crystal phase is not high. Its main contribution lies in the great optimization of stability.

[0096] In addition, the present invention has verified that combinations of different types of sunscreen agents, such as in Examples 11 to 13, all passed the stability test, with the main difference being the change in sunscreen performance.

[0097] 5. As can be seen from Comparative Examples 6 to 8, the stability of each component was significantly improved, indicating that the selection of surfactant, oily solvent, and amount of polyol are key factors in maintaining the stability of the system in this case.

[0098] 6. As can be seen from Comparative Examples 9 and 10, the α-gel phase emulsion system has better stability, while the ordinary emulsion system is difficult to maintain stability with a small amount of emulsifier and a large amount of oily components.

[0099] Skin feel test One hundred and ten healthy female volunteers were randomly divided into eleven groups of ten each. Each group used Examples 1 to 3, Examples 7 to 9, and Comparative Examples 3, 6 to 8, and 10, respectively. Usage: After cleansing, apply the sunscreen lotion at a concentration of 2 mg / cm³. 2 Apply evenly to the face once daily for 7 consecutive days. Efficacy was assessed using a questionnaire.

[0100] Key evaluation indicators: Skin feel index: Very dislike (sticky, not absorbed, heavy, poor spreadability), Neutral (slightly sticky, poor absorption, average spreadability), Very good (no oiliness, refreshing, easily absorbed, good spreadability).

[0101] The test results are shown in Table 2, using the percentage of user preferences as a comparison criterion.

[0102] Table 2 Skin Feel Test Example 1 0 1 9 Example 2 0 2 8 Example 3 0 4 6 Example 7 0 5 5 Example 8 0 3 7 Example 9 1 1 8 Comparative Example 3 1 1 8 Comparative Example 6 6 4 0 Comparative Example 7 5 3 2 Comparative Example 8 7 3 0 Comparative Example 9 4 4 2

[0103] Analysis of the data in Table 2 shows that the sunscreens in Examples 1 and 2 have a better skin feel. Volunteers felt refreshed and non-greasy after using them. As can be seen from Examples 1-3, adjusting the type and amount of emulsifier will result in different skin feel of phase D emulsifier. Using sodium stearoyl glutamate and cetearyl glucoside has a better skin feel. Increasing the amount of emulsifier will make the skin feel thicker. As can be seen from Examples 7-9, the type and weight of the oily solvent and the type of polyol will have a certain impact on the skin feel. From the perspective of overall performance, Examples 1-3 have the best effect.

[0104] Comparative Example 3 and Example 1 show that using lauroyl sarcosine, which has a good skin feel and a solubilizing and stabilizing effect on sunscreen agents, helps to improve the overall skin feel of D-phase emulsified sunscreen agents.

[0105] As can be seen from Comparative Example 6, the only problem caused by the increase of emulsifier is the skin feel, which is also the core problem that this application aims to solve.

[0106] As can be seen from Comparative Example 7, the increase of polyols leads to a certain degree of decrease in skin feel; as can be seen from Comparative Example 8, the increase of oily solvents significantly deteriorates the skin feel.

[0107] As can be seen from Comparative Example 9, the α-gel phase emulsification system, due to the use of more long-chain fatty alcohols, showed a significant decrease in skin feel compared to the D-phase emulsification system of this invention. Although long-chain fatty alcohols have a certain degree of sebum-like properties, they are not friendly to users with oily skin. Among the volunteers who expressed strong dislike, 3 had oily skin.

[0108] As can be seen from the data in Table 1 and Comparative Examples 6 to 8 and 10, there is a contradiction between skin feel and stability. As can be seen from Examples 1 to 3, this invention fully solves the problem and achieves a synergistic improvement in skin feel and stability.

[0109] Summarize: 1. From a stability perspective, the following factors are relevant: the formulation of the sunscreen lotion, the choice of emulsifier, the amount of polyol, and the amount of oily solvent are crucial; among them, in the D-phase emulsion system, increasing the amount of polyol and / or oily solvent to more than 10 wt% can reduce the requirements for the emulsifying performance of the emulsifier; conversely, the optimal combination of emulsifiers can reduce the amount of polyol and oily solvent to below 10 wt%, which promotes an improved skin feel. At the same time, it should be noted that the instability of Comparative Examples 1 and 2 at high temperatures is not only related to the presence of liquid crystal phase, but also closely related to the amount of polyol and / or oily solvent used. Comparative Examples 7 and 8 can be referenced. It can be argued that if sunscreen lotion is to achieve a balance between stability and skin feel, the formulation, emulsifier selection, polyol dosage, and oil solvent dosage of sunscreen lotion must all be reasonably controlled and closely related. 2. From the perspective of sun protection performance, it is related to the sunscreen agent itself, as well as the uniformity of dispersion and emulsification of the sunscreen agent (including the type of emulsion such as D-phase emulsification, α-gel and ordinary emulsion system, as well as the amount of emulsifier and emulsification process, etc.). The correlation and importance of sun protection performance with liquid crystal phase and type of emulsifier (assuming similar degree of emulsification) is not as great as the former. 3. From the perspective of skin feel, the emulsifier, polyol, oily solvent, and long-chain fatty acids in the emulsion system are related. To achieve a good skin feel and stability, based on the results of the above examples and comparative examples, the D-phase emulsion system of the present invention is undoubtedly the best choice.

[0110] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A sunscreen emulsified system which is compatible with skin feel and stability, characterized in that, The sunscreen emulsification system is prepared by a D-phase emulsification process using an alcohol phase, an oil phase, and an aqueous phase. With a total weight of 100 wt% for the sunscreen emulsion system, the amount of emulsifier in the sunscreen emulsion system does not exceed 2 wt% and contains sodium stearoyl glutamate and an auxiliary emulsifier; the sodium stearoyl glutamate and the auxiliary emulsifier can form a liquid crystal in the sunscreen emulsion system; the auxiliary emulsifier is potassium cetyl phosphate and / or cetearyl glucoside; The alcohol phase contains the emulsifier, 6-10 wt% polyol, and 5-10 wt% water; The oil phase contains 15-19 wt% oil-soluble sunscreen agent and 7-10 wt% oily solvent; The oily solvent is composed of lauroyl sarcosine isopropyl ester, octyl polymethylsiloxane, and methyl polytrimethylsiloxane; the amount of lauroyl sarcosine isopropyl ester is 2-4 wt%.

2. The sunscreen emulsified system according to claim 1, characterized in that, The oil-soluble sunscreen agent is one or more combinations of octocrylene, ethylhexyl methoxycinnamate, humosalidinyl ester, isooctyl salicylate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoyl hexyl benzoate, ethylhexyl triazine ketone, and butyl methoxydibenzoylmethane.

3. The sunscreen emulsified system according to claim 2, characterized in that, The sunscreen agent also includes water-soluble sunscreen agents and / or inorganic sunscreen agents; The amount of the water-soluble sunscreen agent is 0~8wt%; the amount of the inorganic sunscreen agent is 0~10wt%; wherein the amount of the water-soluble sunscreen agent and the amount of the inorganic sunscreen agent are not both 0; The water-soluble sunscreen agent is one or more of the following: terephthalic methylene dicamphor sulfonic acid, methylene bis-benzotriazolyl tetramethyl butylphenol, phenylbenzimidazole sulfonic acid, and disodium phenyl dibenzimidazole tetrasulfonate. The inorganic sunscreen agent is nano-titanium dioxide and / or nano-zinc oxide powder.

4. The sunscreen emulsified system according to claim 1, characterized in that, The polyol is glycerol and / or butanediol.

5. The sunscreen emulsified system according to claim 1, characterized in that, The oil phase also contains one or more of the following: skin feel modifiers, film-forming agents, and thickeners.

6. The sunscreen emulsification system according to any one of claims 1 to 5, characterized in that, The amount of sodium stearoyl glutamate used is 0.5~1wt%.

7. Use of sunscreen products prepared using the sunscreen emulsification system as described in any one of claims 1 to 6.

8. A sunscreen product, characterized in that, It contains a sunscreen emulsification system as described in any one of claims 1 to 6; the sunscreen product is a sunscreen lotion.

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