Composite sun-screening agent as well as preparation method and application thereof

Abstract

The invention discloses a composite sun-screening agent and a preparation method and application thereof, the composite sun-screening agent comprises a core layer and a shell layer, the material of the core layer comprises inorganic sun-screening particles, and the material of the shell layer comprises silicon dioxide and a natto extract; during preparation, the surface of the core shell is coated with a silicon dioxide precursor, and then the surface is coated with the natto extract; the composite sun-screening agent disclosed by the invention realizes the integration of multiple functions of sun screening, oxidation resistance, skin care and repair and the like, has obvious advantages in the aspects of sun-screening stability, skin protection capability, use skin feeling, formula stability, safety, environmental friendliness and the like when being used in cosmetics, can simultaneously realize an oxidation resistance effect and an ultraviolet protection effect, and has a good application prospect. And more comprehensive skin protection is provided. In addition, cosmetics adopting the composite sun-screening agent disclosed by the invention also have excellent skin feelings such as refreshing degree, fitting property, high absorption speed and the like.

Description

Technical Field

[0001] This invention relates to the field of daily chemical products, specifically to a composite sunscreen agent, its preparation method, and its application. Background Technology

[0002] Ultraviolet (UV) radiation is a major external factor causing skin damage, photoaging, and inflammatory responses. Based on wavelength, it can be divided into UVA (320-400 nm), UVB (280-320 nm), and UVC (100-280 nm). UVC is typically absorbed by the ozone layer, but ozone layer depletion may exacerbate its harmful effects. UVA and UVB, however, can penetrate the atmosphere and directly affect the skin, triggering a series of physiological and pathological changes. UVA has strong penetrating power, reaching deep into the dermis, damaging collagen and elastin fibers, leading to skin laxity and increased wrinkles, thus promoting photoaging. UVB primarily affects the epidermis, directly damaging DNA and inducing the formation of DNA damage products such as cyclobutanepyrimidine dimers (CPDs), thereby causing gene mutations and increasing the risk of skin cancer. Furthermore, UVB radiation can activate the NF-κB signaling pathway, inducing keratinocytes to release pro-inflammatory factors (such as IL-6 and TNF-α), leading to skin inflammation, erythema, and sunburn. Therefore, sunscreen products should not only provide effective UV protection, but also have antioxidant properties to reduce oxidative stress and skin damage caused by UV rays.

[0003] Currently, most sunscreens on the market are based on physical sunscreens (such as titanium dioxide (TiO2) and zinc oxide (ZnO) or chemical sunscreens (such as avobenzone, benzophenone, and octyl methoxycinnamate). Physical sunscreens block ultraviolet (UV) rays through light scattering and a small amount of light absorption. Titanium dioxide is widely used due to its broad-spectrum UV shielding ability and good chemical stability. However, titanium dioxide particles may produce a photocatalytic effect under UV irradiation, leading to the generation of free radicals (ROS), which can exacerbate skin oxidative stress and inflammation. Meanwhile, traditional inorganic sunscreens can easily cause whitening, dryness, and uneven application, affecting the user experience. In contrast, chemical sunscreens protect the skin by absorbing UV energy and converting it into heat. However, some chemical sunscreens have poor photostability, are easily degraded, are highly irritating, and can cause allergies, and may even pollute the environment. Furthermore, most sunscreens only provide UV shielding and lack repair mechanisms against UV-induced skin inflammation, free radical damage, and impaired barrier function. Long-term use may exacerbate skin aging or sensitivity issues.

[0004] It should be noted that the information disclosed in the background section above is only for understanding the background of this application. Therefore, the background section of this invention may include background information about the problems or environment of this invention, and is not necessarily a description of the prior art. Thus, the content included in the background section does not constitute an admission of the prior art by the applicant. Summary of the Invention

[0005] The purpose of this invention is to overcome one or more shortcomings in the prior art and provide a new and improved composite sunscreen.

[0006] The present invention also provides a method for preparing the above-mentioned composite sunscreen and its application in cosmetics.

[0007] To achieve the above objectives, the present invention employs the following technical solution: A composite sunscreen agent comprising a core layer and a shell layer, wherein the core layer is composed of inorganic sunscreen particles and the shell layer is composed of silica and natto extract; By mass percentage, the inorganic sunscreen particles account for 70%-85% of the composite sunscreen agent, the silica accounts for 5%-20%, and the natto extract accounts for 0.01%-15%.

[0008] In some embodiments of the present invention, the inorganic sunscreen particles account for 74%-83% of the composite sunscreen agent by mass percentage, the silica accounts for 8%-20%, and the natto extract accounts for 1%-10%.

[0009] In some embodiments of the present invention, the inorganic sunscreen particles comprise titanium dioxide and / or zinc oxide.

[0010] In some embodiments of the present invention, the silica in the shell layer forms a silica coating layer with a porous structure, and the natto extract is at least partially embedded in the porous structure.

[0011] In some embodiments of the present invention, the natto extract interacts with the surface hydroxyl groups of the silica to form hydrogen bonds.

[0012] In some embodiments of the present invention, the composite sunscreen agent is in the form of needles.

[0013] Another technical solution provided by the present invention: a method for preparing the above-mentioned composite sunscreen agent, the preparation method comprising: Inorganic sunscreen particles are dispersed in water to form a substrate solution; Under heating and stirring conditions, sodium silicate and an acid solution are added to the substrate solution, and the reaction is carried out under the condition that the pH value of the system is controlled at 8-9. After the reaction, the first reaction solution is obtained. The pH of the first reaction solution was adjusted to 3-5. Sodium silicate and acid solution were added under heating and stirring conditions. The reaction was carried out under pH 3-4 conditions. After the reaction, the second reaction solution was obtained. The solution was separated to obtain inorganic sunscreen particles coated with silica. Inorganic sunscreen particles coated with silica were activated under heating conditions and then mixed with natto extract. In some embodiments of the present invention, the method for preparing the substrate solution includes: dispersing inorganic sunscreen particles in water, and then mechanically grinding and ultrasonically dispersing them to obtain the substrate solution.

[0014] In some embodiments of the present invention, sodium silicate is added in the form of an aqueous sodium silicate solution, and further, the content of silicon dioxide in the aqueous sodium silicate solution is controlled to be 40-60 g / L.

[0015] In some embodiments of the present invention, the acid solution includes one or more combinations of hydrochloric acid, aqueous sulfuric acid solution, aqueous nitric acid solution, and aqueous phosphoric acid solution.

[0016] In some embodiments of the present invention, during the process of obtaining the first reaction solution and the second reaction solution, the heating conditions are controlled to keep the system temperature at 50-60°C.

[0017] In some embodiments of the present invention, the activation is controlled to be carried out at 75-90°C, and further at 80-85°C.

[0018] In some embodiments of the present invention, the activated silica-coated inorganic sunscreen particles are mixed with natto extract at 75-90°C.

[0019] In some embodiments of the present invention, the mass of sodium silicate added is measured in terms of the amount of silicon dioxide. In the process of obtaining the first reaction solution and the second reaction solution, the mass of silicon dioxide added is 10%-40% of the mass of inorganic sunscreen particles.

[0020] In some embodiments of the present invention, the amount of natto extract added is based on the principle that the natto extract accounts for 0.01%-15% of the compound sunscreen.

[0021] In some embodiments of the present invention, after adding natto extract and mixing, heat treatment is continued at 75-90°C, followed by pulverization.

[0022] Another technical solution provided by the present invention is the application of a composite sunscreen agent as described above, or a composite sunscreen agent prepared by the preparation method of the composite sunscreen agent described above, in cosmetics.

[0023] Furthermore, the cosmetic product in question is a sunscreen cosmetic product.

[0024] Another technical solution provided by the present invention: a sunscreen product, wherein, by weight percentage, the sunscreen product comprises: The aforementioned composite sunscreen agent, or the composite sunscreen agent prepared by the aforementioned preparation method, comprises 1%-20% of the product. Cyclopentadimethylsiloxane 20%-45% Distearate, lithium dimethylammonium montmorillonite, 0.1%-3% Butylene glycol dioctanoic acid / didecanoate 1%-10% Glyceryl caprylate 0.01%-0.5% Caprylyl glycol 0.01%-0.5% PEG-10 polydimethylsiloxane 1%-5% Lauryl PEG-9 Polydimethylsiloxane 0.05%-1.0% Magnesium sulfate 0.2%-2.0% water; Adjust the water content to make the overall sunscreen cosmetic product meet 100%.

[0025] Furthermore, the sunscreen product also contains 1,2-hexanediol and butylene glycol.

[0026] In some embodiments of the present invention, the sunscreen product contains 0.1%-2% 1,2-hexanediol and 1%-10% butylene glycol by weight percentage.

[0027] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: This invention provides a multifunctional sunscreen agent that integrates sun protection, anti-oxidation, and skin repair. When used in cosmetics, this composite sunscreen agent offers significant advantages in sun protection stability, skin protection ability, user experience, and safety and environmental friendliness. It simultaneously provides antioxidant and UV protection effects, offering more comprehensive skin protection. Furthermore, cosmetics using this composite sunscreen agent exhibit excellent formulation stability and utilize naturally derived ingredients, resulting in a significant safety advantage and making them more suitable for the skin, reducing the risk of irritation. In addition, cosmetics using this composite sunscreen agent demonstrate superior skin feel in terms of lightness, adherence, and rapid absorption, providing an excellent user experience and meeting consumers' demands for effective skincare and a comfortable feel. Attached Figure Description

[0028] Figure 1 This is a comparison image of the XRD pattern of the composite sunscreen agent prepared in Example 1 of the present invention with that of a standard card; Figure 2 Here is a SEM image of the composite sunscreen agent prepared in Example 1 of this invention; Figure 3 The image shows a test diagram of the antioxidant efficacy of the composite sunscreen agent prepared in Example 1 of this invention and titanium dioxide. Figure 4 This is a test diagram of the dispersibility of the composite sunscreen agent prepared in Example 1 of the present invention with titanium dioxide in a solvent; Figure 5 The figures show the stability test results of the samples obtained by applying Comparative Example 1 and Comparative Example 2 in this invention. Detailed Implementation

[0029] Current sunscreen particles still face challenges such as high irritation from active ingredients, easy degradation, and poor dispersibility. Therefore, the industry continues to explore more biocompatible, stable, and multifunctional sunscreen technologies. Plant-derived ingredients, due to their safety advantages, have become an important direction for natural ingredient development and efficacy research. However, despite extensive research, functional ingredients primarily composed of plant and bioactive components suffer from poor formulation stability in cosmetic formulations, especially sunscreen formulations, limiting their application to small quantities or preventing them from fully realizing their intended functions.

[0030] The core concept of this invention is to first coat inorganic sunscreen particles (such as TiO2) with a silica coating layer, especially a porous silica coating layer, and then coat the surface with natto extract, forming a stable composite sunscreen agent. This simultaneously achieves sun protection, anti-inflammatory repair, and antioxidant protection, overcoming many limitations of existing sunscreen products. Traditional sunscreen technologies typically focus only on the physical or chemical blocking of ultraviolet rays, neglecting the oxidative damage caused to the skin by ultraviolet rays. This invention innovatively combines silica, natto extract, and an inorganic sunscreen agent, enabling it to provide highly effective sun protection while utilizing the bioactive components in natto extract to enhance the skin's antioxidant capacity, inhibit inflammation, and reduce redness and sensitivity caused by ultraviolet rays. Furthermore, this unique composite structure ensures the stability, slow-release properties, and pleasant skin feel of the natto extract in the sunscreen product, avoiding the dryness or grainy feeling that is common with traditional inorganic sunscreen agents.

[0031] The present invention has the following advantages: (1) Reduce the photocatalytic activity of inorganic powders and enhance sun protection stability: This invention effectively inhibits the photocatalytic activity of TiO2 by coating the surface of TiO2 with silica and natto extract, thereby reducing the generation of free radicals and reducing oxidative damage to the skin. It also improves the photostability of sunscreen agents, enhances the durability of sun protection, and avoids skin irritation or decreased protective effect caused by the degradation of sunscreen agents.

[0032] (2) Imparting anti-inflammatory and repair functions to sunscreen products: Most existing sunscreen products only have the function of ultraviolet shielding, which cannot alleviate skin inflammation and oxidative stress caused by ultraviolet rays. This invention uses natto extract, which can reduce the release of inflammatory factors and significantly reduce skin irritation and barrier damage caused by ultraviolet rays.

[0033] (3) Improve the skin feel and user experience of sunscreen products: Traditional inorganic sunscreens tend to form a thick, white coating due to their large particle size, which affects the skin feel. The composite sunscreen of this invention encapsulates TiO2 particles with silica and natto extract, which improves their dispersibility, reduces the powdery feel, and enhances the skin's hydration, making the product smoother and lighter, and allowing the sunscreen product to adhere better to the skin, providing a better skin feel.

[0034] (4) Improved formula safety and reduced skin irritation and environmental impact: Compared with the potential sensitization problems caused by traditional chemical sunscreens, this invention uses natto extract from natural sources, which improves skin tolerance and reduces the potential risks of allergies and irritation. In addition, this invention avoids the adverse environmental impacts (such as marine ecosystems) that some chemical sunscreens may cause, which is in line with the trend of modern sunscreen products upgrading towards green, safe and sustainable development.

[0035] (5) Wide applicability, suitable for various sun protection products: Due to the excellent comprehensive properties of the product of this invention, such as sun protection, anti-inflammation and skin care, it can be widely used in various sun protection products, such as sunscreen, sun lotion, cushion, foundation, and isolation cream, to enhance the overall skin care effect of cosmetics. In addition, this invention can also be applied to sensitive skin care, sun protection repair products and other fields, further expanding the market application space.

[0036] In summary, this invention overcomes the limitations of traditional sunscreens that rely solely on inorganic or chemical sunscreen agents. It innovatively combines physical sun protection, anti-inflammatory repair, and antioxidant protection, achieving a multi-functional fusion of sun protection, antioxidant properties, and skin repair. This provides a more efficient, safer sunscreen technology solution with multiple skincare functions, possessing significant application value and market potential in the sunscreen cosmetics industry.

[0037] This invention provides a composite sunscreen agent comprising a core layer and a shell layer, wherein the core layer is composed of inorganic sunscreen particles and the shell layer is composed of silica and natto extract. By mass percentage, the inorganic sunscreen particles account for 70%-85% of the composite sunscreen agent, the silica accounts for 5%-20%, and the natto extract accounts for 0.01%-15%.

[0038] The present invention also provides a method for preparing a composite sunscreen agent, the method comprising: dispersing inorganic sunscreen particles in water to form a substrate solution; Under heating and stirring conditions, sodium silicate and an acid solution are added to the substrate solution, and the reaction is carried out under the condition that the pH value of the system is controlled at 8-9. After the reaction, the first reaction solution is obtained. The pH of the first reaction solution was adjusted to 3-5. Sodium silicate and acid solution were added under heating and stirring conditions. The reaction was carried out under pH 3-4 conditions. After the reaction, the second reaction solution was obtained. The solution was separated to obtain inorganic sunscreen particles coated with silica. Inorganic sunscreen particles coated with silica were activated under heating conditions and then mixed with natto extract.

[0039] Furthermore, in some embodiments, taking titanium dioxide particles as an example of inorganic sunscreen particles, the method for preparing the composite sunscreen agent includes: A titanium dioxide aqueous solution (formed by dispersing titanium dioxide particles in water) was prepared and uniformly dispersed by mechanical grinding and ultrasonication. During vigorous stirring and dispersion, the reaction temperature was controlled at 50-60℃, while sodium silicate solution and hydrochloric acid were slowly added. The pH of the reaction system was adjusted in real time to stabilize it at 8-9, allowing sodium silicate to hydrolyze to form hydrated silica, which gradually deposited on the surface of the titanium dioxide particles to form a dense silica coating layer. Subsequently, the pH of the reaction system was adjusted to 3-5, and the temperature was maintained at 50-60℃ under vigorous stirring. Sodium silicate solution and hydrochloric acid were added again, and the pH was controlled to stabilize it at 3-4, allowing sodium silicate to hydrolyze to form silicic acid, which gradually deposited to form a loose silica coating layer. After the reaction, the particles were washed multiple times with deionized water to remove soluble salts. The powder was dried at 90-100℃ for 6-8 hours to obtain a dry powder. This powder was then subjected to air jet milling to obtain silica-coated titanium dioxide.

[0040] Silica-coated titanium dioxide is added to a mixer and heated to 80-85°C to activate the surface. Natto extract is uniformly atomized and sprayed into the mixer at a constant speed, and mixing continues at 80-85°C. After mixing, the mixture is cooled to room temperature, transferred to a tray, and then heat-treated at 80-85°C. Finally, it is pulverized by air jet milling to obtain the composite sunscreen agent.

[0041] The above-mentioned solution will be further described below with reference to specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0042] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0043] In the following description, titanium dioxide was purchased from Qingdao Shanghui New Material Technology Co., Ltd. (HTR-10S), and natto extract solution was purchased from Bloomage Biotechnology Co., Ltd. The raw material composition is shown in Table 1.

[0044]

[0045] Example 1: This example provides a composite sunscreen agent and its preparation method. The preparation method of the composite sunscreen agent includes: Take 1L of titanium dioxide aqueous solution (titanium dioxide content approximately 100 g / L), and disperse it evenly through mechanical grinding and ultrasonication. During vigorous stirring and dispersion, control the reaction temperature at 55℃, and slowly add 0.5L of sodium silicate aqueous solution (silica content approximately 50 g / L) and 10% hydrochloric acid. Adjust the pH of the reaction system in real time to stabilize it at around 8.5, allowing sodium silicate to hydrolyze to form hydrated silica, which gradually deposits on the surface of titanium dioxide particles to form a dense silica coating layer. Subsequently, adjust the pH of the reaction system to around 4, maintain the temperature at 55℃ under vigorous stirring, and add another 0.5L of sodium silicate aqueous solution (silica content approximately 50 g / L) and 10% hydrochloric acid, controlling the pH to stabilize it at around 3.5, allowing sodium silicate to hydrolyze to form silicic acid, which gradually deposits to form a loose silica coating layer. After the reaction was completed, the slurry was washed three times with deionized water at a volume of 4 to remove soluble salts. The powder was dried at 95°C for 8 hours to obtain a dry powder, which was then pulverized by air jet milling to obtain silica-coated titanium dioxide.

[0046] 10 kg of silica-coated titanium dioxide was added to a mixer and heated at 82°C for 2 hours to activate the surface. A natto extract solution, at approximately 5% (w / w) by weight of the powder, was uniformly atomized and sprayed into the mixer at a constant speed, and mixing continued at 82°C for 3 hours. After mixing, the mixture was cooled to room temperature, and the coated material was transferred to a tray for further heat treatment at 82°C for 3 hours. Finally, it was subjected to air jet milling to obtain the composite sunscreen agent.

[0047] Example 2: This example provides a composite sunscreen agent and its preparation method, which is basically the same as Example 1, except that: the titanium dioxide content in the titanium dioxide aqueous solution is about 120 g / L, the sodium silicate content in the sodium silicate aqueous solution is calculated as silicon dioxide and is about 55 g / L, and the natto extract solution is added at about 8% (w / w) of the powder weight.

[0048] Example 3: This example provides a composite sunscreen agent and its preparation method, which is basically the same as Example 1, except that: the titanium dioxide content in the titanium dioxide aqueous solution is about 80 g / L, the sodium silicate content in the sodium silicate aqueous solution is calculated as silicon dioxide and is about 45 g / L, and the natto extract solution is added at about 4% (w / w) of the powder weight.

[0049] Performance Test 1: The following experiment uses the composite sunscreen prepared in Example 1.

[0050] Experiment 1: Titanium Dioxide Content Analysis Take 0.05g of the compound sunscreen agent, dissolve it in acid, and bring the volume to 25mL. Dilute it 100 times, test the Ti element content using ICP, and calculate the TiO2 content. The results show that the TiO2 content in the compound sunscreen agent is approximately 77.53%, as shown in Table 2.

[0051]

[0052] Experiment 2: Analysis of Silica Content 5g of powder was taken, processed, and the Si element content was tested by X-ray fluorescence spectroscopy (XRF), and the SiO2 content was calculated. The results showed that the SiO2 content in the composite sunscreen was approximately 15.35%, as shown in Table 3.

[0053]

[0054] Experiment 3: XRD Analysis To observe the effects of surface coatings with silica and natto extract on the structure of titanium dioxide, the composite sunscreen agent was analyzed using X-ray diffraction (XRD). Samples were prepared according to XRD testing requirements, and the diffraction peaks of the 111 crystal plane were measured. The rutile 110 crystal plane peaks were approximately 27°, with angles ranging from 25° to 29°. The crystal form was determined by comparison with standard cards.

[0055] See results Figure 1 As shown, the results indicate that the characteristic peaks of the XRD pattern of the composite sunscreen agent match those of the rutile standard card, indicating that the titanium dioxide in this composite sunscreen agent has a rutile structure. This confirms that during the process of coating titanium dioxide particles with silica and natto extract to form the composite sunscreen agent, the properties of titanium dioxide did not change, and no new impurities were generated.

[0056] Experiment 4: Scanning Electron Microscopy The composite sunscreen agent obtained in Example 1 was tested using scanning electron microscopy. The resulting SEM image is shown below. Figure 2As shown in the figure, the coated composite sunscreen agent is evenly distributed, and no obvious large particle agglomeration was observed. This indicates that silica and natto extract form a thin coating layer on the surface of titanium dioxide, thereby improving its dispersion stability.

[0057] Experiment 5: Evaluation of Antioxidant Effect The antioxidant efficacy of the compound sunscreen was tested using the DPPH method, and the results are as follows. Figure 3 As shown in the figure. The results showed that when the mass concentration of the composite sunscreen agent was 6 mg / mL, the DPPH scavenging rate was 17.24%; titanium dioxide, as the control group, did not show any effect in scavenging DPPH free radicals at the same mass concentration, indicating that the encapsulated composite sunscreen agent has certain antioxidant activity.

[0058] Experiment 6: Dispersibility of Compound Sunscreen Agents Titanium dioxide, due to its surface physicochemical properties, is prone to agglomeration, which affects the stability of the formulation and weakens its UV shielding effect. To test the dispersibility of composite sunscreen agents, equal weights of the composite sunscreen agent and unencapsulated titanium dioxide were placed in a cyclopentamethoxysiloxane solvent, mixed and dispersed for 5 minutes, and then allowed to stand. The deposition effect was observed after 0 h, 1 h, 2 h, and 4 h. Results are shown below. Figure 4 As shown, the results indicate that the composite sunscreen agent did not show obvious stratification after standing for 4 hours, but the unencapsulated titanium dioxide component showed obvious stratification, indicating that the composite sunscreen agent of the present invention has better dispersibility and higher stability in the solvent.

[0059] The reason for this is that after titanium dioxide is coated with silica and natto extract, the silica and natto extract form a coating layer on the surface of the titanium dioxide particles. This coating layer prevents the titanium dioxide particles from directly contacting each other through steric hindrance, inhibits the aggregation of titanium dioxide particles, and improves its stability. Therefore, when the composite sunscreen is applied to cosmetics, it is less likely to separate, which is beneficial for its application in cosmetic formulations.

[0060] Application Examples and Comparative Examples: The formulations of the application examples and comparative examples are shown in Table 4. Each sample was subjected to performance testing under the same conditions. The performance tests included stability testing, sun protection, antioxidant, and skin feel evaluation.

[0061] To prepare a common sunscreen base, add the raw material combination shown in Table 4 below, and add deionized water to bring the total to 100%. Stir at a speed of about 1500 rpm for 10 minutes to obtain the test sample.

[0062]

[0063] Cyclopentamethoxydimethylsiloxane was purchased from Shin-Etsu Chemical Industry Co., Ltd., grade KF-995; distearate dimethylammonium lithium montmorillonite was purchased from Hymens, grade BENTONE® 38 V CG; butanediol dioctanoic acid / didecanoate was purchased from IOI Oleo GmbH, grade MIGLYOL® 8810; glyceryl caprylate was purchased from IOI Oleo GmbH, grade SOFTISAN® GC8; octyl glycol was purchased from EVONIK, grade Dermosoft® Octiol; PEG-10 polydimethylsiloxane was purchased from Shin-Etsu Chemical Industry Co., Ltd., grade KF-6107; lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane was purchased from Shin-Etsu Chemical Industry Co., Ltd., grade KF-6038.

[0064] Performance Test 2: Experiments 1 to 3.

[0065] Experiment 1: Dosage Form Viscosity and Stability Test Under the condition of rotor speed of 10 r / min (LV rotor 63), the viscosity of the prepared application example 1 and application comparative examples 1-3 was measured. The results showed that application example 1, application comparative examples 2 and application comparative examples 3 all had high viscosity and no mobile phase was observed by the naked eye; application comparative example 1 had low viscosity and strong fluidity. The viscosity results are shown in Table 5.

[0066] The prepared application examples 1 and application comparative examples 1-3 were placed under different conditions (room temperature, 5℃, 40℃, 50℃, Cycle (6h at -5℃, 6h at 5℃, 6h at 25℃, 6h at 40℃), and Freeze-thaw (24h at -18℃, 24h at 25℃, three cycles) to examine their stability. The results showed that no oil separation phenomenon was observed in application example 1 and application comparative example 3 in all stability tests, indicating high formulation stability. Conversely, after one month (1M), application comparative example 1 showed separation at 40℃ and 50℃, and application comparative example 2 showed separation at 40℃, 50℃, Cycle, and -18℃. The results are shown in Table 5. Figure 5 As shown.

[0067]

[0068] Experiment 2: Evaluation of Sunscreen Efficacy The sun protection effect of Application Example 1 and Application Comparative Examples 1-3 was evaluated. The results showed that the SPF of Application Example 1, which contained a compound sunscreen agent, was 39.17, showing a more significant sun protection effect than Application Comparative Examples 1, 2 and 3.

[0069]

[0070] Experiment 3: Sensory Evaluation Test Ten eligible subjects were selected. After cleaning, the sample was evenly applied and its adherence, refreshing feel, absorption speed, and irritation were assessed using sensory evaluation. Each item was scored from 0 to 7. The higher the score, the more satisfied or positive the user was with the experience of using the sample on the evaluated area (Table 7-8).

[0071]

[0072] Sensory evaluation results showed that Application Example 1 exhibited better fit and refreshing feel than Application Comparative Example 1, Application Comparative Example 2, and Application Comparative Example 3, and also absorbed faster and was non-irritating.

[0073] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0074] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A composite sunscreen agent, characterized in that, The composite sunscreen agent comprises a core layer and a shell layer, wherein the core layer is made of inorganic sunscreen particles and the shell layer is made of silica and natto extract; By mass percentage, the inorganic sunscreen particles account for 70%-85% of the composite sunscreen agent, the silica accounts for 5%-20%, and the natto extract accounts for 0.01%-15%.

2. The composite sunscreen agent according to claim 1, characterized in that, By mass percentage, the inorganic sunscreen particles comprise 74%-83% of the composite sunscreen agent, the silica comprises 8%-20% of the silica, and the natto extract comprises 1%-10% of the silica; and / or, the inorganic sunscreen particles comprise titanium dioxide and / or zinc oxide.

3. The composite sunscreen agent according to claim 1, characterized in that, In the shell layer, the silica forms a silica coating layer with a porous structure, and the natto extract is at least partially embedded in the porous structure; and / or, hydrogen bonds are formed between the natto extract and the surface hydroxyl groups of the silica; and / or, the composite sunscreen agent is needle-shaped.

4. A method for preparing the composite sunscreen agent according to any one of claims 1-3, characterized in that, The preparation method includes: Inorganic sunscreen particles are dispersed in water to form a substrate solution; Under heating and stirring conditions, sodium silicate and an acid solution are added to the substrate solution, and the reaction is carried out under the condition that the pH value of the system is controlled at 8-9. After the reaction, the first reaction solution is obtained. The pH of the first reaction solution was adjusted to 3-5. Sodium silicate and acid solution were added under heating and stirring conditions. The reaction was carried out under pH 3-4 conditions. After the reaction, the second reaction solution was obtained. The solution was separated to obtain inorganic sunscreen particles coated with silica. Inorganic sunscreen particles coated with silica were activated under heating conditions and then mixed with natto extract.

5. The method for preparing the composite sunscreen agent according to claim 4, characterized in that, The method for preparing the substrate solution includes: dispersing inorganic sunscreen particles in water, followed by mechanical grinding and ultrasonic dispersion to obtain the substrate solution; and / or, Sodium silicate is added in the form of an aqueous sodium silicate solution, and further, the silica content in the aqueous sodium silicate solution is controlled to be 40-60 g / L; and / or, Acid solutions include one or more of the following: hydrochloric acid, sulfuric acid aqueous solution, nitric acid aqueous solution, and phosphoric acid aqueous solution.

6. The method for preparing the composite sunscreen agent according to claim 4, characterized in that, In obtaining the first reaction solution and the second reaction solution, the heating conditions are controlled to maintain the system temperature at 50-60°C; and / or, The activation is controlled to be carried out at 75-90°C, and further at 80-85°C; and / or, The activated silica-coated inorganic sunscreen particles were mixed with natto extract at 75-90℃.

7. The method for preparing the composite sunscreen agent according to claim 4, characterized in that, The mass of sodium silicate added is based on the amount of silicon dioxide. In obtaining the first reaction solution and the second reaction solution, the mass of silicon dioxide added is 10%-40% of the mass of the inorganic sunscreen particles, respectively; and / or, The natto extract is added based on a weight of 0.01%-15% of the compound sunscreen; and / or, after adding the natto extract and mixing, it is further heat-treated at 75-90°C and then pulverized.

8. The use of a composite sunscreen agent according to any one of claims 1-3, or a composite sunscreen agent prepared by the preparation method of any one of claims 4-7, in cosmetics.

9. The application according to claim 8, characterized in that, The cosmetic product in question is a sunscreen product.

10. A sunscreen product, characterized in that, The sunscreen product comprises, by weight percentage: The composite sunscreen agent according to any one of claims 1-3, or the composite sunscreen agent prepared by the method of any one of claims 4-7, comprises 1%-20% of the product. Cyclopentadimethylsiloxane 20%-45% Distearate, lithium dimethylammonium montmorillonite, 0.1%-3% Butylene glycol dioctanoic acid / didecanoate 1%-10% Glyceryl caprylate 0.01%-0.5% Caprylyl glycol 0.01%-0.5% PEG-10 polydimethylsiloxane 1%-5% Lauryl PEG-9 Polydimethylsiloxane 0.05%-1.0% Magnesium sulfate 0.2%-2.0% Water; adjust the water content to make the sunscreen cosmetic product meet 100% overall.

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