Sunscreen gels and methods for making the same

Abstract

This application belongs to the field of cosmetic technology, specifically disclosing a sunscreen gel and its preparation method. The sunscreen gel comprises: 0.5%~5% of an organosilicon elastomer gel, 3%~15% of silicone oils, 1%~3% of lauroyl sarcosine isopropyl ester, 0.8%~2.5% of an organosilicon emulsifier, 10%~20% of a moisturizer, 15%~20% of a sunscreen agent, 40%~69.7% of water, and 0.1%~1% of an acrylic (ester) polymer. Therefore, this sunscreen gel is transparent in appearance, has a good skin feel, good formula safety and stability, and a high sun protection factor (SPF).

Description

Technical Field

[0001] This application belongs to the field of cosmetic technology, specifically relating to a sunscreen gel and its preparation method. Background Technology

[0002] With social development and increased public awareness of cosmetics through various channels, consumers have increasingly diverse and demanding needs for sun protection, leading to a growing popularity of products with unique textures. Currently, commercially available transparent sunscreen gels mainly include all-oil systems and water-in-oil emulsions. All-oil systems are greasy and unpopular with consumers; water-in-oil emulsions, with their stable formulations and pleasant skin feel, are also difficult to produce. Therefore, providing a stable, transparent sunscreen gel with a high SPF has broad market value and application prospects. Summary of the Invention

[0003] This application aims to at least partially address one of the technical problems in the related art. To this end, this application proposes a sunscreen gel with a high SPF, transparent texture, good skin feel, simple preparation method, or good formulation stability, as well as a method for preparing the same.

[0004] The first aspect of this application discloses a sunscreen gel, comprising, by weight percentage: 0.5% to 5% of silicone elastomer gel, 3% to 15% of silicone oil, 1% to 3% of lauroyl sarcosine isopropyl ester, 0.8% to 2.5% of silicone emulsifier, 10% to 20% of moisturizer, 15% to 20% of sunscreen agent, 40% to 69.7% of water, and 0.1% to 1% of acrylic (ester) polymer.

[0005] This application introduces lauroyl sarcosine isopropyl ester, which is highly compatible with acrylate polymers and sunscreen agents, and a transparent silicone elastomer gel into the formulation of a sunscreen gel, resulting in a water-in-oil sunscreen gel. This sunscreen gel is transparent, has a high SPF, good formulation safety and stability, and uses readily available and common materials, making it easy to use. Specifically, lauroyl sarcosine isopropyl ester has high solubility for sunscreen agents, significantly increasing the SPF value. The silicone elastomer gel effectively adsorbs oily sunscreen agents, preventing self-agglomeration in the formulation or the formation of island-like structures due to compatibility issues during film formation. This ensures that the active ingredients in the sunscreen agent are evenly distributed, forming a continuous, defect-free protective film on the skin surface with waterproof properties, thereby increasing the SPF value of the formulation. The introduction of acrylate polymers helps improve the stability of the formulation. The synergistic effect of these three components contributes to improving the SPF value and stability of the sunscreen gel.

[0006] In some embodiments, the acrylic (ester) polymer includes at least one of an acrylic (ester) crosslinked polymer, an acrylic (ester) copolymer, and an acrylic (ester) / stearyl polyether-20 methacrylate copolymer. Adding this polymer to the formulation helps to further improve formulation stability.

[0007] In some embodiments, the silicone oil comprises silicone oil or modified silicone oil with a viscosity of less than 10 cst; in other embodiments, based on the total mass of the sunscreen gel, the silicone oil comprises 1% to 5% octyl polymethylsiloxane and 1% to 5% phenyl polytrimethylsiloxane. This facilitates adjustment of the sunscreen gel's feel on the skin and improves the formulation's transparency and SPF value.

[0008] In some embodiments, the silicone elastomer gel comprises at least one of cyclopentasiloxane (and) polydimethylsiloxane crosslinked polymers, polydimethylsiloxane (and) polydimethylsiloxane crosslinked polymers, cyclopentasiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymers, polydimethylsiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymers, and octyl polymethylsiloxane (and) polydimethylsiloxane / PEG-12 polydimethylsiloxane crosslinked polymers. This can improve the SPF value and light transmittance of the sunscreen gel.

[0009] Octyl polydimethylsiloxane (and) polydimethylsiloxane / PEG-12 polydimethylsiloxane crosspolymers have better compatibility with sunscreen agents due to the presence of PEG groups and octyl groups, making the formulation easier to make transparent.

[0010] In some embodiments, the silicone emulsifier contains a hydrophilic group, which includes at least one of the following: an ether group of polyether, an ether group of polyglycerol, and a hydroxyl group. In other embodiments, the silicone emulsifier includes at least one of the following: PEG-10 polydimethylsiloxane, cetyl PEG / PPG-10 / 1 polydimethylsiloxane, lauryl PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane, and PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane. Therefore, the materials are commonly available and have low cost.

[0011] In some embodiments, the sunscreen agent includes both water-soluble and oil-soluble sunscreen agents. Using both water-soluble and oil-soluble sunscreen agents can provide comprehensive UV protection, increase SPF value, improve formula stability, enhance skin feel, increase water resistance, and improve compatibility and safety.

[0012] In some embodiments, the water-soluble sunscreen agent includes at least one of terephthalic acid dicamphor sulfonic acid and its salts, and phenylbenzimidazole sulfonic acid and disodium phenyl dibenzimidazole tetrasulfonate. Therefore, the materials are widely available and the cost is low.

[0013] In some embodiments, the oil-soluble sunscreen agent includes at least one of polysiloxane-15 and ethylhexyl methoxycinnamate. Therefore, the materials are widely available and inexpensive.

[0014] In some embodiments, the amount of polysiloxane-15 added is ≤3% based on the total mass of the sunscreen gel. Polysiloxane-15 and silicone oils have similar structures, good compatibility, and facilitate the formation of transparent compositions.

[0015] In some embodiments, the amount of ethylhexyl methoxycinnamate added is ≤1% based on the total mass of the sunscreen gel. Adding ethylhexyl methoxycinnamate within the above range is beneficial for dissolving the sunscreen gel and improving its transparency.

[0016] In some embodiments, the moisturizer comprises a polyol moisturizer and purslane extract, wherein the polyol moisturizer comprises at least one selected from dipropylene glycol, 1,2-propanediol, 1,2-butanediol, and glycerin; in other embodiments, the polyol moisturizer is glycerin. This enhances the moisturizing effect of the sunscreen gel.

[0017] In some embodiments, the sunscreen gel further includes preservatives and fragrances. This facilitates the imparting of fragrance and preservative properties to the sunscreen gel.

[0018] The second aspect of this application discloses a method for preparing a sunscreen gel, comprising:

[0019] The first sunscreen agent is dissolved in water to obtain the first mixture;

[0020] The acrylic (ester) polymer is dispersed evenly with the first mixture to obtain a second mixture;

[0021] The second mixture is mixed with a humectant to obtain a third mixture;

[0022] The fourth mixture is obtained by mixing the silicone elastomer gel, acrylate cross-linked polymer, silicone oil, silicone emulsifier, lauroyl sarcosine isopropyl ester, and the second sunscreen agent.

[0023] The third mixture is mixed with the fourth mixture to obtain a fifth mixture.

[0024] This application prepares a sunscreen gel using the above method, introducing lauroyl sarcosine isopropyl ester, which is compatible with acrylic (ester) polymers and sunscreen agents, and an organosilicon elastomer gel with a transparent appearance, to obtain a water-in-oil transparent sunscreen gel. The preparation method is simple to operate, the raw materials are common and readily available, and it is easy to realize industrial production.

[0025] In some embodiments, the first sunscreen agent comprises a water-soluble sunscreen agent, and the second sunscreen agent comprises an oil-soluble sunscreen agent.

[0026] In some embodiments, the pH range of the first mixture is 7 to 7.5. This facilitates the dissolution of the sunscreen agent.

[0027] In some embodiments, the method for preparing the sunscreen gel further includes: mixing the fourth mixture with a preservative and a fragrance until homogeneous to obtain the sunscreen gel. Detailed Implementation

[0028] The embodiments of this application are described in detail below and are intended to explain this application, but should not be construed as limiting this application.

[0029] The first aspect of this application discloses a sunscreen gel, comprising, by weight percentage: 0.5% to 5% of silicone elastomer gel, 3% to 15% of silicone oil, 1% to 3% of lauroyl sarcosine isopropyl ester, 0.8% to 2.5% of silicone emulsifier, 10% to 20% of moisturizer, 15% to 20% of sunscreen agent, 40% to 69.7% of water, and 0.1% to 1% of acrylic (ester) polymer.

[0030] This application introduces lauroyl sarcosine isopropyl ester, which is highly compatible with acrylate polymers and sunscreen agents, and a transparent silicone elastomer gel into the formulation of a sunscreen gel, resulting in a water-in-oil sunscreen gel. This sunscreen gel is transparent, has a high SPF, good formulation safety and stability, and uses readily available and common materials, making it easy to use. Specifically, lauroyl sarcosine isopropyl ester has high solubility for sunscreen agents, significantly increasing the SPF value. The silicone elastomer gel effectively adsorbs oily sunscreen agents, preventing self-agglomeration in the formulation or the formation of island-like structures due to compatibility issues during film formation. This ensures that the active ingredients in the sunscreen agent are evenly distributed, forming a continuous, defect-free protective film on the skin surface with waterproof properties, thereby increasing the SPF value of the formulation. The introduction of acrylate polymers helps improve the stability of the formulation. The synergistic effect of these three components contributes to improving the SPF value and stability of the sunscreen gel.

[0031] In some embodiments, the acrylic (ester) polymer includes at least one of cross-linked acrylic (ester) polymers, acrylic (ester) copolymers, and acrylic (ester) / stearyl polyether-20 methacrylate copolymers. It is understood that acrylic (ester) polymers are a class of high molecular weight compounds formed by the polymerization reaction of acrylic acid or its ester monomers, possessing a cross-linked network structure. Adding the aforementioned acrylic (ester) polymers to the formulation is beneficial for further improving formulation stability.

[0032] In some embodiments, the silicone oil comprises silicone oil or modified silicone oil with a viscosity of less than 10 cst; in other embodiments, based on the total mass of the sunscreen gel, the silicone oil comprises 1% to 5% octyl polymethylsiloxane and 1% to 5% phenyl polytrimethylsiloxane. This facilitates adjustment of the sunscreen gel's feel on the skin and improves the formulation's transparency and SPF value.

[0033] In some embodiments, the silicone elastomer gel comprises at least one of the following: cyclopentamethoxysiloxane (and) polydimethylsiloxane crosslinked polymers, polydimethylsiloxane (and) polydimethylsiloxane crosslinked polymers, cyclopentamethoxysiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymers, polydimethylsiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymers, and octyl polymethylsiloxane (and) polydimethylsiloxane / PEG-12 polydimethylsiloxane crosslinked polymers. The silicone elastomer gel is a three-dimensional network structure formed through a crosslinking reaction, filled with silicone oil (such as cyclopentamethoxysiloxane, polydimethylsiloxane, octyl polymethylsiloxane). This three-dimensional network structure is not a complete solid, but a stable gel system that locks the liquid (silicone oil) inside. The network structure is prepared by Si-H addition reaction of hydrogen-containing silicone oil and alkane / silicone oil / polyether silicone oil containing dual-terminal vinyl groups, which can improve the SPF value and light transmittance of sunscreen gel.

[0034] In some embodiments, the silicone emulsifier contains a hydrophilic group, which includes at least one of the following: an ether group of polyether, an ether group of polyglycerol, and a hydroxyl group. In other embodiments, the silicone emulsifier includes at least one of the following: PEG-10 polydimethylsiloxane, cetyl PEG / PPG-10 / 1 polydimethylsiloxane, lauryl PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane, and PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane. The silicone emulsifier effectively stabilizes the oil and water phases in the sunscreen gel, preventing stratification, ensuring product uniformity, and improving skin feel, water resistance, film formation, compatibility, and safety through emulsification.

[0035] In some embodiments, the sunscreen agent comprises a water-soluble sunscreen agent and an oil-soluble sunscreen agent. The water-soluble sunscreen agent comprises at least one of terephthalimide dicamphor sulfonic acid and its salts, and phenylbenzimidazole sulfonic acid and disodium phenyldibenzimidazole tetrasulfonate; the oil-soluble sunscreen agent comprises at least one of polysiloxane-15 and ethylhexyl methoxycinnamate. The simultaneous use of both water-soluble and oil-soluble sunscreen agents can provide comprehensive UV protection, increase SPF value, improve formula stability, enhance skin feel, enhance water resistance, and improve compatibility and safety.

[0036] In some embodiments, the amount of polysiloxane-15 added is ≤3% based on the total mass of the sunscreen gel, for example, it can be 1%, 1.5%, 2%, 2.5%, or 3%. Polysiloxane-15 and silicone oils have similar structures, good compatibility, and facilitate the formation of a transparent composition. Structural similarity enhances interfacial interactions: all components are based on a siloxane backbone, and this structural similarity makes them more compatible when mixed, resulting in stronger interfacial bonding. This similarity enhances the binding energy of Si-O bonds, making the co-formed sunscreen film more robust and stable. Furthermore, the silicone elastomer gel can effectively adsorb oily sunscreens like polysiloxane-15, preventing self-agglomeration of the sunscreen in the formulation or the formation of island-like structures due to compatibility issues during film formation. This ensures that the active ingredients in the sunscreen are evenly distributed, forming a continuous, defect-free protective film on the skin surface.

[0037] In some embodiments, the amount of ethylhexyl methoxycinnamate added is ≤1% based on the total mass of the sunscreen gel, for example, it can be 0.2%, 0.4%, 0.6%, 0.8%, or 1%. Ethylhexyl methoxycinnamate, as a liquid sunscreen agent with a small molecular weight, is compatible with other oils in the composition, but its addition amount should not be too high, as excessive amounts will lead to insolubility and insufficient transparency of the composition. Adding ethylhexyl methoxycinnamate within the above-mentioned range is beneficial for dissolving the gel and improving its transparency.

[0038] In some embodiments, the moisturizer comprises a polyol moisturizer and purslane extract, wherein the polyol moisturizer comprises at least one selected from dipropylene glycol, 1,2-propanediol, 1,2-butanediol, and glycerin; in other embodiments, the polyol moisturizer is glycerin. This enhances the moisturizing effect of the sunscreen gel.

[0039] In some embodiments, the sunscreen gel further includes a preservative and a fragrance. For example, the preservative may be phenoxyethanol or ethylhexylglycerin, and the fragrance may be phenethyl alcohol or vanillin. Adding these two ingredients to the sunscreen gel imparts a fragrance and preservative properties.

[0040] The second aspect of this application discloses a method for preparing a sunscreen gel, comprising:

[0041] S1: Dissolve the first sunscreen agent in water to obtain the first mixture.

[0042] Specifically, the first sunscreen agent can be mixed with water and stirred, and then the pH can be adjusted.

[0043] Furthermore, the pH can be adjusted to 7-7.5 using organic bases such as triethanolamine, tromethamine, or 2-amino-2-methyl-1-propanol, for example, 7, 7.1, 7.2, 7.3, 7.4, or 7.5. The introduction of metal ions reduces the water solubility of the sunscreen agent, terephthalamide dicamphor sulfonic acid. In some specific examples, the first waterproofing agent can be a water-soluble sunscreen agent, including at least one of terephthalamide dicamphor sulfonic acid and its salts, and phenylbenzimidazole sulfonic acid or disodium phenylbenzimidazole tetrasulfonate.

[0044] S2: Disperse the acrylic (ester) polymer evenly with the first mixture to obtain a second mixture.

[0045] Specifically, dilute the acrylic (ester) polymer with 3 times the amount of water and add it to the first mixture and stir well; adjust the pH to 7~7.5 with the pH adjuster of the first mixture.

[0046] S3: Mix the second mixture with a humectant to obtain a third mixture.

[0047] Specifically, the humectant can be added to the second mixture mentioned above and stirred until well mixed before use.

[0048] In some embodiments, the moisturizer comprises a polyol moisturizer and purslane extract, wherein the polyol moisturizer comprises at least one selected from dipropylene glycol, 1,2-propanediol, 1,2-butanediol, and glycerin; in other embodiments, the polyol moisturizer is glycerin. The mass fraction of the moisturizer is 10% to 20% based on the total mass of the sunscreen gel, for example, 10%, 12%, 14%, 16%, 18%, or 20%. Adding the above-mentioned mass fraction of moisturizer to the formulation helps enhance the moisturizing effect of the sunscreen gel.

[0049] S4: Mix the silicone elastomer gel, silicone oil, silicone emulsifier, lauroyl sarcosine isopropyl ester, and the second sunscreen agent to obtain the fourth mixture.

[0050] In this step, there is no specific limitation on the mixing method of the silicone elastomer gel, silicone oil, silicone emulsifier, lauroyl sarcosine isopropyl ester, and the second sunscreen agent, and the order of addition can be flexibly selected according to specific needs.

[0051] In some embodiments, the silicone elastomer gel comprises at least one of the following: cyclopentamethoxysiloxane (and) polydimethylsiloxane crosslinked polymer, polydimethylsiloxane (and) polydimethylsiloxane crosslinked polymer, cyclopentamethoxysiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymer, polydimethylsiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymer, and octyl polymethylsiloxane (and) polydimethylsiloxane / PEG-12 polydimethylsiloxane crosslinked polymer. The mass fraction of the silicone elastomer gel is 0.5% to 5% based on the total mass of the sunscreen gel, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%. Adding the above-mentioned mass fraction of silicone elastomer gel to the formulation can improve the SPF value and light transmittance of the sunscreen gel.

[0052] In some embodiments, based on the total mass of the sunscreen gel, the silicone oil comprises silicone oil or modified silicone oil with a viscosity of less than 10 cst; in some specific examples, the silicone oil comprises 1% to 5% octyl polymethylsiloxane and 1% to 5% phenyl polytrimethylsiloxane. This facilitates adjustment of the sunscreen gel's feel on the skin and improves the formulation's transparency and SPF value.

[0053] In some embodiments, the silicone emulsifier contains a hydrophilic group, which includes at least one selected from the groups of ether groups of polyethers, ether groups of polyglycerols, and hydroxyl groups. In other embodiments, the silicone emulsifier includes at least one selected from the groups of PEG-10 polydimethylsiloxane, cetyl PEG / PPG-10 / 1 polydimethylsiloxane, lauryl PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane, and PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane. The mass fraction of the silicone emulsifier is 0.8% to 2.5% based on the total mass of the sunscreen gel, for example, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, or 2.5%. The silicone emulsifier effectively stabilizes the oil and water phases in the sunscreen gel, prevents layering, ensures product uniformity, and improves skin feel, water resistance, film formation, compatibility, and safety through emulsification.

[0054] In some embodiments, the mass fraction of lauroyl sarcosine isopropyl ester is 1% to 3% based on the total mass of the sunscreen gel, for example, it can be 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, or 3%. This is beneficial for improving the transparency of the sunscreen gel and increasing the SPF value.

[0055] In some specific examples, the second waterproofing agent may be an oil-soluble sunscreen agent, including at least one of polysiloxane-15 and ethylhexyl methoxycinnamate. Specifically, based on the total mass of the sunscreen gel, the amount of polysiloxane-15 added is ≤3%, and the amount of ethylhexyl methoxycinnamate added is ≤1%.

[0056] S5: Mix the third mixture with the fourth mixture to obtain the fifth mixture.

[0057] Specifically, the third mixture can be slowly added to the fourth mixture, and stirring, emulsification, and homogenization can be started.

[0058] In some embodiments, the method for preparing the sunscreen gel further includes: mixing the fourth mixture with a preservative and a fragrance until homogeneous to obtain the sunscreen gel.

[0059] In some specific examples, preservatives may be phenoxyethanol or ethylhexylglycerin, and fragrances may include phenethyl alcohol or vanillin. Adding these two ingredients to sunscreen gels imparts both fragrance and preservative properties.

[0060] The embodiments of this application are described in detail below.

[0061] Example 1

[0062] (1) Dissolve terephthalimide dicamphor sulfonic acid and phenylbenzimidazole sulfonic acid in water, and adjust the pH to 7.5 with triethanolamine to obtain the first mixture;

[0063] (2) Disperse the acrylic (ester) copolymer with the mixed solution of step (1) evenly to obtain a second mixture;

[0064] (3) Based on the total mass of the sunscreen gel, add 16% glycerol by mass to the mixed solution in step (2) and stir until homogeneous to obtain a third mixture for later use;

[0065] (4) After mixing and dispersing methyl polytrimethylsiloxane, phenyl polytrimethylsiloxane, octyl polymethylsiloxane and polydimethylsiloxane, add lauroyl sarcosine isopropyl ester and cyclopentapolydimethylsiloxane (and) polydimethylsiloxane cross-linked polymer and disperse evenly. Then add ethylhexyl methoxycinnamate, polysiloxane-15, lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane, PEG-10 polydimethylsiloxane and other fat-soluble components and stir evenly to obtain the fourth mixture;

[0066] (5) Start stirring and slowly add the mixture from step (3) to the mixture from step (4) to emulsify and homogenize to obtain the fifth mixture;

[0067] (6) Add phenoxyethanol, ethylhexylglycerin, fragrance and purslane extract to the mixture in step (5) and stir until well mixed;

[0068] (7) Packaging.

[0069] Examples 2-22, Comparative Examples 1-4

[0070] The operating steps are the same as in Example 1, and the differences in raw materials and proportions are shown in Tables 1-1 and 1-2.

[0071] Table 1-1 Raw Materials and Proportions

[0072]

[0073]

[0074]

[0075]

[0076] Table 1-2 Raw Materials and Proportions

[0077]

[0078]

[0079]

[0080]

[0081]

[0082] " / " indicates that the substance was not added.

[0083] The testing method is as follows:

[0084] (1) Viscosity test: The material was kept at a constant temperature of 25°C, and the results were tested and recorded using a Bollerfeld viscometer, RVT model, 20 rpm, and a No. 4 rotor;

[0085] (2) Stability test: If the sample does not separate into layers after centrifugation at 2500 rpm for 30 minutes, does not separate into layers after standing at 48℃ for two months, does not separate into layers after standing at 5℃ for two months, and the viscosity change after each test does not exceed 10%, then it is considered stable.

[0086] (3) SPF value test: The SPF value of the sample was tested according to the operating procedure using the SOLAR SPF-290S instrument and the results were recorded;

[0087] (4) Transmittance test: Using a UV-1700 UV-Vis spectrophotometer, centrifuge the sample at 2000 rpm for 5 minutes to remove air bubbles from the system, and place it in a 1 cm cuvette, trying to avoid introducing air bubbles. If air bubbles are present, adjust them with a toothpick to level them. Clean the outer surface of the cuvette, place it in the absorption cell, and perform the test at a wavelength of 420 nm. Display the test results after completion.

[0088] The test results are shown in Table 2 below.

[0089] Table 2 Test Results

[0090]

[0091] As can be seen from Table 2, this application introduces acrylic (ester) copolymers, lauroyl sarcosine isopropyl ester which is compatible with sunscreen agents, and organosilicon elastomer gel with a transparent appearance into the sunscreen gel formulation, which makes the sunscreen gel transparent, has a high sun protection factor, and has high formulation safety and stability.

[0092] In Example 22, no preservatives were added, which led to bacterial growth in the formula and made the sunscreen gel system unstable.

[0093] Compared with Example 1, Example 21 did not include octyl polymethylsiloxane and phenyl polytrimethylsiloxane, resulting in a slightly lower SPF value and light transmittance of the sunscreen gel. This indicates that adding octyl polymethylsiloxane and phenyl polytrimethylsiloxane to the formulation can improve the transparency and sun protection effect of the sunscreen gel.

[0094] The formulation of Comparative Example 1 did not include silicone elastomer gel, resulting in a lower SPF value for the sunscreen gel. This indicates that the addition of transparent silicone elastomer gel helps to form a uniform film on the skin surface, increasing the SPF value of the sunscreen gel, and has little impact on light transmittance.

[0095] Comparative Example 2 did not include lauroyl sarcosine isopropyl ester in its formula, resulting in a lower SPF value for the sunscreen gel. This indicates that lauroyl sarcosine isopropyl ester can increase the SPF value and has a synergistic effect on sun protection.

[0096] The formulation of Comparative Example 3 did not contain silicone elastomer gel, phenyl polytrimethylsiloxane, and lauroyl sarcosine isopropyl ester, resulting in poor stability of the sunscreen gel and lower SPF value and light transmittance.

[0097] Comparative Example 4 did not contain any acrylic (ester) polymers, resulting in an unstable sunscreen gel. This indicates that the addition of aqueous acrylic (ester) polymers can improve the stability of the formulation.

[0098] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0099] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0100] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A sunscreen gel, characterized in that, By weight percentage, it includes: 0.5% to 5% silicone elastomer gel, 3% to 15% silicone oils, 1% to 3% lauroyl sarcosine isopropyl ester, 0.8% to 2.5% silicone emulsifier, 10% to 20% moisturizer, 15% to 20% sunscreen, 40% to 69.7% water, and 0.1% to 1% acrylic (ester) polymer; Based on the total mass of the sunscreen gel, the silicone oil comprises 1% to 5% octyl polymethylsiloxane and 1% to 5% phenyl polytrimethylsiloxane; The organosilicon elastomer gel comprises at least one of the following: cyclopentasiloxane (and) polydimethylsiloxane crosslinked polymer, polydimethylsiloxane (and) polydimethylsiloxane crosslinked polymer, cyclopentasiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymer, polydimethylsiloxane (and) polydimethylsiloxane / vinyl polydimethylsiloxane crosslinked polymer, and octyl polymethylsiloxane (and) polydimethylsiloxane / PEG-12 polydimethylsiloxane crosslinked polymer; The sunscreen agents include water-soluble sunscreen agents and oil-soluble sunscreen agents; The water-soluble sunscreen agent includes at least one of terephthalic dicamphor sulfonic acid and its salts, and phenylbenzimidazole sulfonic acid and disodium phenyl dibenzimidazole tetrasulfonate. The oil-soluble sunscreen agents include polysiloxane-15 and ethylhexyl methoxycinnamate; The acrylic (ester) polymer is an acrylic (ester) copolymer; The organosilicon emulsifier includes at least one of PEG-10 polydimethylsiloxane, cetyl PEG / PPG-10 / 1 polydimethylsiloxane, lauryl PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane, and PEG-9 polydimethylsiloxane-ethyl polydimethylsiloxane.

2. The sunscreen gel according to claim 1, characterized in that, The silicone-based greases include silicone oils or modified silicone oils with a viscosity of less than 10 cst.

3. The sunscreen gel according to claim 1, characterized in that, Based on the total mass of the sunscreen gel, the amount of polysiloxane-15 added is ≤3%; and / or Based on the total mass of the sunscreen gel, the amount of ethylhexyl methoxycinnamate added is ≤1%.

4. The sunscreen gel according to claim 1, characterized in that, The moisturizer includes a polyol moisturizer and purslane extract, wherein the polyol moisturizer includes at least one of dipropylene glycol, 1,2-propanediol, 1,2-butanediol, and glycerin.

5. The sunscreen gel according to claim 4, characterized in that, The polyol moisturizer is glycerin.

6. A method for preparing a sunscreen gel according to any one of claims 1 to 5, characterized in that, include: The water-soluble sunscreen agent is dissolved in water to obtain the first mixture; The acrylic (ester) polymer is uniformly dispersed with the first mixture to obtain a second mixture; The second mixture is mixed with a humectant to obtain a third mixture; A fourth mixture is obtained by mixing organosilicon elastomer gel, silicone oil, organosilicon emulsifier, lauroyl sarcosine isopropyl ester, and oil-soluble sunscreen agent. The third mixture is mixed with the fourth mixture to obtain a fifth mixture.

7. The method according to claim 6, characterized in that, The pH range of the first mixture is 7 to 7.5.

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