Sunscreen powder slurry, preparation method thereof and sunscreen cosmetic

Abstract

The invention relates to the field of cosmetics, in particular to sunscreen powder slurry, a preparation method thereof and a sunscreen cosmetic. The sunscreen powder slurry comprises a yeast melanin solution, sunscreen powder, a dispersing agent, an emulsifying agent and grease; the proportion of the yeast melanin solution in the sunscreen powder syrup is 0.00001%-10%; the sunscreen powder accounts for more than 50% of the sunscreen powder syrup; the sunscreen powder comprises any one of unmodified titanium dioxide, modified titanium dioxide, unmodified zinc oxide or modified zinc oxide; the average particle size of the sunscreen powder in the sunscreen powder slurry is 100-380 nm. The melanin has the capability of scavenging free radicals, and can be used as an additional defense line to quench reactive oxygen free radicals generated after the skin is irradiated by ultraviolet rays, so that secondary light protection is provided, and the light aging damage of the skin is relieved. The particle size of the particles is far smaller than the wavelength of visible light, and scattering of the visible light is weakened, so that the false white feeling is remarkably relieved, and the skin feeling is more natural and transparent.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cosmetics, in particular, to a sunscreen powder slurry, a preparation method thereof and a sunscreen cosmetic. BACKGROUND

[0002] With the improvement of people's living standards and the increasing concern for skin health, the demand for sunscreen products is growing. Traditional sunscreen products are mainly divided into two categories: chemical sunscreen and physical sunscreen. Chemical sunscreen has good sunscreen effect, but some ingredients such as benzophenone-3 and octyl methoxycinnamate may be absorbed into the blood and urine through the skin, causing skin sensitivity and endocrine interference. While physical sunscreen such as titanium dioxide and zinc oxide has good reflection and scattering effect on ultraviolet rays, but has the disadvantages of easy "fake white" when used in large quantities, poor dispersibility, poor occlusivity and skin feel. SUMMARY

[0003] The purpose of the embodiments of the present application is to provide a sunscreen powder slurry, a preparation method thereof and a sunscreen cosmetic.

[0004] In a first aspect, the present application provides a sunscreen powder slurry, which comprises: a yeast melanin solution, a sunscreen powder, a dispersant, an emulsifier and an oil; wherein the proportion of the yeast melanin solution in the sunscreen powder slurry is 0.00001% to 10% by mass percentage; and the proportion of the sunscreen powder in the sunscreen powder slurry is more than 50%; The sunscreen powder comprises any one of unmodified titanium dioxide, modified titanium dioxide, unmodified zinc oxide or modified zinc oxide. The average particle size of the sunscreen powder in the sunscreen powder slurry is 100 nm to 380 nm.

[0005] In the above technical solutions, physical sunscreen powders, such as unmodified titanium dioxide, modified titanium dioxide, unmodified zinc oxide, or modified zinc oxide, primarily function by reflecting and scattering ultraviolet rays, with particularly significant effects in the UVB and short-wave UVA regions. Yeast melanin is a biological macromolecule whose chemical structure effectively absorbs ultraviolet rays and dissipates them as heat energy; its absorption spectrum typically covers UVA and even the visible light region. In the above technical solutions, when yeast melanin is combined with physical powders, it compensates for the insufficient absorption of physical powders in the long-wave UVA region, forming a complementary protective network of "reflection + scattering + absorption" with the physical sunscreen agent, thereby significantly improving the broad-spectrum sun protection performance of the formula and resulting in a substantial increase in the SPF value of the sunscreen powder. Furthermore, the above technical solutions can effectively reduce the "whitening effect" and improve skin feel and makeup finish. Typically, when physical sunscreen agents are used in large quantities, the strong scattering of visible light can produce an unnatural "whitening effect." Yeast melanin, being brownish-red in color, can neutralize or reduce the excessive whitening effect of physical sunscreens, making the skin tone look more natural and consistent, thus enhancing the product's aesthetic appeal and user experience. Furthermore, melanin itself has the ability to scavenge free radicals. In sunscreen products, it can act as an extra layer of protection, quenching reactive oxygen species generated after UV exposure, thereby providing secondary photoprotection and reducing photoaging damage to the skin. Compared to commonly used chemical sunscreens, yeast-derived melanin is a "bio-based" and "naturally sourced" ingredient, posing no risk of skin irritation or other problems. Furthermore, the average particle size of the sunscreen powder in the aforementioned sunscreen powder is 100nm~500nm. According to Mie scattering theory, when the particle size is close to or slightly smaller than the UV wavelength (290-400nm), its scattering and absorption efficiency for UV rays is highest. The vast majority of particles in the sunscreen powder of this application fall within this high-efficiency range, thus achieving a higher SPF value with a smaller dosage. Furthermore, within this range, the particles are broken down into uniform, fine primary particles, intensifying Brownian motion. Simultaneously, due to the increased specific surface area, the dispersant can more effectively adsorb and coat, fundamentally inhibiting Austronesian ripening and aggregation sedimentation, thus achieving "non-stratification" and greatly improving the stability of the sunscreen powder. Further, within this range, the particle size is much smaller than the wavelength of visible light (400-700nm), reducing the scattering of visible light and significantly alleviating the "fake whiteness," resulting in a more natural and transparent feel on the skin.

[0006] In other embodiments of this application, the yeast melanin solution accounts for 0.01% to 10% of the sunscreen powder by weight percentage.

[0007] In other embodiments of this application, the proportion of sunscreen powder in sunscreen paste is 50% to 80% by mass percentage.

[0008] In other embodiments of this application, after centrifugation at 5000 rpm for 15 minutes, the sediment volume of the sunscreen powder is less than 1% of the total volume; In other embodiments of this application, optionally, at 25°C and a shear rate of 10 s... -1 Under these conditions, the viscosity of the sunscreen powder is 5000 mPa·s ~ 50000 mPa·s.

[0009] In other embodiments of this application, the modified titanium dioxide includes at least one of the following: alumina-modified titanium dioxide, aluminum hydroxide-modified titanium dioxide, silica-modified titanium dioxide, stearic acid-modified titanium dioxide, triethoxyoctylsilane-modified titanium dioxide, polymethylsiloxane-modified titanium dioxide, polydimethylsiloxane-modified titanium dioxide, isopropoxytitanium triisostearate-modified titanium dioxide, stearoylglutamic acid-modified titanium dioxide, magnesium myristate-modified titanium dioxide, jojoba ester-modified titanium dioxide, lecithin-modified titanium dioxide, or hydrogenated lecithin-modified titanium dioxide.

[0010] In other embodiments of this application, the modified zinc oxide includes at least one of the following: stearic acid modified zinc oxide, triethoxyoctylsilane modified zinc oxide, polymethylsiloxane modified zinc oxide, polydimethylsiloxane modified zinc oxide, triisostearate isopropoxytitanium triisostearate modified zinc oxide, stearoylglutamic acid modified zinc oxide, magnesium myristate modified zinc oxide, jojoba ester modified zinc oxide, lecithin modified zinc oxide, or hydrogenated lecithin modified zinc oxide.

[0011] In other embodiments of this application, the dispersant includes at least one of the following: polyhydroxystearic acid, organobentonite, fumed silica, cetearyl alcohol, polyglycerol esters, or acrylates.

[0012] In other embodiments of this application, the emulsifier includes at least one of polyglycerol-3 diisostearate, sorbitan oleate, sorbitan sesquioleate, or polyglycerol-6 polyricinoleate.

[0013] In other embodiments of this application, the oils include one or more combinations of oils such as isononyl isononanoate, jojoba seed oil, sunflower seed oil, caprylic / capric triglyceride, isododecane, and C12-15 benzoyl alcohol.

[0014] Secondly, this application provides a method for preparing sunscreen powder, comprising: Yeast melanin, sunscreen powder, dispersant, emulsifier and oil are mixed to obtain a mixture; The mixture is pumped into a long, narrow pipe, and the mixture in the pipe is subjected to ultrasonic treatment; After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

[0015] In other embodiments of this application, the inner diameter of the pipe is 4mm-8mm; optionally, the length of the pipe is 20m or more.

[0016] In other embodiments of this application, the ultrasonic power is 300W-800W.

[0017] In other embodiments of this application, the volume of the material pool is 40ml-80ml.

[0018] In other embodiments of this application, the ultrasound duration is 1 min - 10 min.

[0019] Thirdly, this application provides a sunscreen cosmetic, including the sunscreen powder of any one of the first aspects. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a microstructure diagram of the sunscreen powder provided in Example 1 of this application; Figure 2 The image shows the microstructure of the sunscreen powder provided in Comparative Example 1 of this application. Figure 3 This is a microstructure diagram of the sunscreen powder provided in Example 2 of this application; Figure 4 Microstructure diagram of the sunscreen powder provided in Comparative Example 2 of this application; Figure 5 Stability test results of the sunscreen powder provided in Example 1 (left) and Comparative Example 1 (right) of this application; Figure 6 The stability test results of the sunscreen powder provided in Example 2 (left) and Comparative Example 2 (right) of this application; Figure 7 The sun protection performance test results of the sunscreens provided in Example 1 and Comparative Example 1 of this application; Figure 8 The sun protection performance test results of the sunscreens provided in Example 2 and Comparative Example 2 of this application are presented. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0023] Therefore, the following detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] This application provides a sunscreen powder, which includes: Yeast melanin solution, sunscreen powder, dispersant, emulsifier and oil; Specifically, by mass percentage, the yeast melanin solution accounts for 0.00001% to 10% of the sunscreen powder; the sunscreen powder accounts for more than 50% of the sunscreen powder. The sunscreen powder includes any one of unmodified titanium dioxide, modified titanium dioxide, unmodified zinc oxide, or modified zinc oxide; The average particle size of the sunscreen powder in the sunscreen paste is 100nm~380nm.

[0025] In the above technical solutions, physical sunscreen powders, such as unmodified titanium dioxide, modified titanium dioxide, unmodified zinc oxide, or modified zinc oxide, primarily function by reflecting and scattering ultraviolet rays, with particularly significant effects in the UVB and short-wave UVA regions. Yeast melanin is a biological macromolecule whose chemical structure effectively absorbs ultraviolet rays and dissipates them as heat energy; its absorption spectrum typically covers UVA and even the visible light region. In the above technical solutions, when yeast melanin is combined with physical powders, it compensates for the insufficient absorption of physical powders in the long-wave UVA region, forming a complementary protective network of "reflection + scattering + absorption" with the physical sunscreen agent, thereby significantly improving the broad-spectrum sun protection performance of the formula and resulting in a substantial increase in the SPF value of the sunscreen powder. Furthermore, the above technical solutions can effectively reduce the "whitening effect" and improve skin feel and makeup finish. Typically, when physical sunscreen agents are used in large quantities, the strong scattering of visible light can produce an unnatural "whitening effect." Yeast melanin, being brownish-red in color, can neutralize or reduce the excessive whitening effect of physical sunscreens, making the skin tone look more natural and consistent, thus enhancing the product's aesthetic appeal and user experience. Furthermore, melanin itself has the ability to scavenge free radicals. In sunscreen products, it can act as an extra layer of protection, quenching reactive oxygen species generated after UV exposure, thereby providing secondary photoprotection and reducing photoaging damage to the skin. Compared to commonly used chemical sunscreens, yeast-derived melanin is a "bio-based" and "naturally sourced" ingredient, posing no risk of skin irritation or other problems. Furthermore, the average particle size of the sunscreen powder in the aforementioned sunscreen powder is 100nm~500nm. According to Mie scattering theory, when the particle size is close to or slightly smaller than the UV wavelength (290-400nm), its scattering and absorption efficiency for UV rays is highest. The vast majority of particles in the sunscreen powder of this application fall within this high-efficiency range, thus achieving a higher SPF value with a smaller dosage. Furthermore, within this range, the particles are broken down into uniform, fine primary particles, intensifying Brownian motion. Simultaneously, due to the increased specific surface area, the dispersant can more effectively adsorb and coat, fundamentally inhibiting Austronesian ripening and aggregation sedimentation, thus achieving "non-stratification" and greatly improving the stability of the sunscreen powder. Further, within this range, the particle size is much smaller than the wavelength of visible light (400-700nm), reducing the scattering of visible light and significantly alleviating the "fake whiteness," resulting in a more natural and transparent feel on the skin.

[0026] Further optionally, and exemplary, in some embodiments of this application, the proportion of yeast melanin solution in the sunscreen powder, by mass percentage, is 0.00001%, 0.0001%, 0.001%, 0.01%, 0.1%, 0.2%, 0.5%, 0.6%, 0.7%, 0.8%, 0.99%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any two of the aforementioned values; the proportion of sunscreen powder in the sunscreen powder is 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, or any two of the aforementioned values.

[0027] Further optionally, the average particle size of the sunscreen powder in the sunscreen powder paste is 100nm, 105nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm, 300nm, 320nm, 350nm, 360nm, 370nm, 380nm, or a range between any two of the aforementioned values.

[0028] Further optionally, the average particle size of the sunscreen powder in the sunscreen powder is 100nm~500nm. Further optionally, the average particle size of the sunscreen powder in the sunscreen powder is 180nm~380nm. Further optionally, the average particle size of the sunscreen powder in the sunscreen powder is 200nm~300nm.

[0029] Furthermore, in some embodiments of this application, the yeast melanin solution accounts for 0.01% to 10% of the sunscreen powder by mass percentage.

[0030] For example, in some embodiments of this application, the proportion of yeast melanin solution in sunscreen powder, by mass percentage, is 0.01%, 0.1%, 1%, 3%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any two of the aforementioned values.

[0031] Furthermore, in some embodiments of this application, the sunscreen powder accounts for 50% to 80% of the sunscreen powder by weight percentage.

[0032] For example, in some embodiments of this application, the proportion of sunscreen powder in sunscreen paste by mass percentage is 50%, 51%, 52%, 53%, 55%, 58%, 60%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, or any two of the aforementioned values.

[0033] In other embodiments of this application, after the sunscreen powder is centrifuged at 5000 rpm for 15 min, the sediment volume is less than 1% of the total volume.

[0034] For example, in some embodiments of this application, after the sunscreen powder is centrifuged at 5000 rpm for 15 min, the sediment volume is 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01% of the total volume or a range between any two of the aforementioned values.

[0035] In other embodiments of this application, optionally, at 25°C and a shear rate of 10 s... -1 Under these conditions, the viscosity of the sunscreen powder is 5000 mPa·s ~ 50000 mPa·s.

[0036] Exemplarily, in other embodiments of this application, at 25°C and a shear rate of 10 s... -1 Under these conditions, the viscosity of the sunscreen powder is 5000 mPa·s, 5050 mPa·s, 5100 mPa·s, 5150 mPa·s, 5200 mPa·s, 5300 mPa·s, 5400 mPa·s, 5500 mPa·s, 5600 mPa·s, 5700 mPa·s, 5800 mPa·s, 6000 mPa·s, 6500 mPa·s, 7000 mPa·s, 8000 mPa·s, 10000 mPa·s, 15000 mPa·s, 20000 mPa·s, 25000 mPa·s, 30000 mPa·s, 35000 mPa·s, 40000 mPa·s, 45000 mPa·s, 50000 mPa·s, or a range between any two of the aforementioned values.

[0037] Furthermore, in some embodiments of this application, the modified titanium dioxide includes at least one of the following: alumina-modified titanium dioxide, aluminum hydroxide-modified titanium dioxide, silica-modified titanium dioxide, stearic acid-modified titanium dioxide, triethoxyoctylsilane-modified titanium dioxide, polymethylsiloxane-modified titanium dioxide, polydimethylsiloxane-modified titanium dioxide, isopropoxytitanium triisostearate-modified titanium dioxide, stearoylglutamic acid-modified titanium dioxide, magnesium myristate-modified titanium dioxide, jojoba ester-modified titanium dioxide, lecithin-modified titanium dioxide, or hydrogenated lecithin-modified titanium dioxide.

[0038] Furthermore, in some embodiments of this application, the modified zinc oxide includes at least one of the following: stearic acid modified zinc oxide, triethoxyoctylsilane modified zinc oxide, polymethylsiloxane modified zinc oxide, polydimethylsiloxane modified zinc oxide, triisostearate isopropoxytitanium triisostearate modified zinc oxide, stearoylglutamic acid modified zinc oxide, magnesium myristate modified zinc oxide, jojoba ester modified zinc oxide, lecithin modified zinc oxide, or hydrogenated lecithin modified zinc oxide.

[0039] Furthermore, in some embodiments of this application, the dispersant includes at least one of the following: polyhydroxystearic acid, organobentonite, fumed silica, cetearyl alcohol, polyglycerol esters, or acrylates.

[0040] Furthermore, in some embodiments of this application, the emulsifier includes at least one of polyglycerol-3 diisostearate, sorbitan oleate, sorbitan sesquioleate, or polyglycerol-6 polyricinoleate.

[0041] Furthermore, in some embodiments of this application, the oils include one or more combinations of oils such as isononyl isononanoate, jojoba seed oil, sunflower seed oil, caprylic / capric triglyceride, isododecane, and C12-15 benzoyl alcohol.

[0042] Furthermore, in some embodiments of this application, the method for preparing sunscreen powder includes the following steps: Yeast melanin, sunscreen powder, dispersant, emulsifier and oil are mixed to obtain a mixture; The mixture is pumped into a long, narrow pipe, and the mixture in the pipe is subjected to ultrasonic treatment; After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

[0043] In some embodiments of this application, the above technical solution involves pumping the mixture into a slender pipe and subjecting the mixture in the pipe to ultrasonic treatment, including: An ultrasonic probe is coupled to the outer wall of the slender pipe. When the mixture is pumped into the slender pipe, the ultrasonic probe on the outer wall of the pipe can perform ultrasonic action on the mixture.

[0044] Within this slender pipe, the ultrasonic energy field is relatively uniform and concentrated. When material is pumped in, passing through this energy field at a high flow rate, each small piece of material and each powder agglomerate within the pipe experiences ultrasonic impacts of almost the same intensity and duration. This ensures that all materials within the pipe receive uniform energy treatment, thereby significantly improving material homogeneity.

[0045] Furthermore, in the above technical solution, by allowing the material to pass through a slender pipe and simultaneously employing ultrasonic dispersion technology, a synergistic effect can be achieved. The main mechanism of ultrasonic dispersion is the "cavitation effect," where the rapid formation and violent collapse of microbubbles in the liquid generate extremely strong local shock waves and microjets. Simultaneously, in a narrow pipe, due to the limited space, the energy generated when these cavitation bubbles collapse is more concentrated and less easily dissipated, thus acting more effectively on the flowing powder agglomerates, breaking them up and resulting in better material uniformity and more uniform particle size. For sunscreen products, a more uniform particle size is beneficial for improving sun protection efficacy.

[0046] Further optionally, in some embodiments of this application, the above-described pumping of the mixture into an elongated pipe and subjecting the mixture in the pipe to ultrasonic treatment includes: The mixture is pumped into a long, narrow pipe, which passes through an ultrasonic field.

[0047] The above technical solution can also achieve the dual synergistic effect of the narrow channel and ultrasonic action on the material inside the pipeline, thus achieving material homogenization and uniform particle size. This is beneficial to improving the sun protection effect of the sunscreen powder.

[0048] Furthermore, in some embodiments of this application, the inner diameter of the pipe is 4mm-8mm.

[0049] For example, in some embodiments of this application, the inner diameter of the pipe is 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm or any two of the aforementioned values.

[0050] In the above technical solution, by setting the inner diameter of the pipe to 4mm-8mm, it is ensured that the material can pass through the pipe at a high linear velocity. This results in high energy density and a strong cavitation effect. It achieves short residence time, high intensity, and continuous processing, realizing sufficient output through high flow rate while ensuring that each batch of material receives extremely strong and uniform ultrasonic impact within a very short time (1-10 minutes). A pipe diameter that is too small is prone to clogging, leading to interruptions; a pipe diameter that is too large results in a significant decrease in energy density, insufficient dispersion force, and failure to achieve the preset uniformity effect.

[0051] Furthermore, in some embodiments of this application, the length of the pipe is 20m or more.

[0052] For example, in some embodiments of this application, the length of the pipe is 20m, 21m, 22m, 23m, 24m, 25m, 26m, 27m, 28m, 29m, 30m or any two of the aforementioned values.

[0053] Furthermore, in some embodiments of this application, the ultrasonic power is 300W-800W.

[0054] For example, in some embodiments of this application, the ultrasonic power is 300W, 350W, 400W, 450W, 500W, 550W, 600W, 650W, 700W, 750W, 800W, or a range between any two of the aforementioned values.

[0055] In the above technical solution, the ultrasonic power is 300 W-800 W. Within this range of ultrasonic power, the homogenization of materials can be effectively achieved.

[0056] Furthermore, in some embodiments of this application, the ultrasound duration is 1 min - 10 min.

[0057] For example, in some embodiments of this application, the ultrasound duration is: 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, 5.5 min, 6 min, 6.5 min, 7 min, 7.5 min, 8 min, 8.5 min, 9 min, 9.5 min, 10 min, or a range between any two of the aforementioned values.

[0058] In the above technical solution, the ultrasonic duration is 1 min - 10 min. Within this time range, the homogenization of materials can be effectively achieved.

[0059] Furthermore, in some embodiments of this application, the volume of the material pool is 40ml-80ml.

[0060] For example, in some embodiments of this application, the volume of the material pool is 40ml, 45ml, 50ml, 55ml, 60ml, 65ml, 70ml, 75ml, 80ml or any two of the aforementioned values.

[0061] Some embodiments of this application provide a sunscreen cosmetic, which includes the sunscreen powder provided in any of the foregoing embodiments.

[0062] Optionally, in some embodiments of this application, the amount of sunscreen powder added to the sunscreen cosmetic is 1wt% to 25wt%. Exemplarily, in some embodiments of this application, the amount of sunscreen powder added to the sunscreen cosmetic is 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 10wt%, 12wt%, 15wt%, 18wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, or a range between any two of the aforementioned values.

[0063] The features and performance of this application will be further described in detail below with reference to embodiments: Example 1 A sunscreen powder is provided, prepared according to the following steps: Step S1: Prepare materials: Weigh out 300g of stearic acid and alumina-modified titanium dioxide, 25g of polyglycerol-3 diisostearate, 160g of jojoba seed oil, 15g of polyhydroxystearic acid, and 5g of filtered 0.1wt% yeast melanin aqueous solution.

[0064] Step S2: Prepare sunscreen powder: The above raw materials are mixed, and the mixture is homogenized at 3000 rpm for 5 minutes to obtain a mixture; then the mixture is pumped into a long and narrow pipe and subjected to ultrasonic treatment in the pipe. After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

[0065] The process involved ultrasonic dispersion for 2 minutes at a power of 400W to prepare titanium dioxide slurry. The inner diameter of the pipe was 5 mm, the length of the pipe was 20 m, and the volume of the material tank was 40 ml.

[0066] Example 2 A sunscreen powder is provided, prepared according to the following steps: Step S1: Prepare materials: Weigh out 335g of triethoxyoctylsilane-modified zinc oxide, 50g of polyglycerol-3 diisostearate, 107.5g of jojoba seed oil, 5g of polyhydroxystearic acid, and 2.5g of filtered 0.1% yeast melanin aqueous solution.

[0067] Step S2: Prepare sunscreen powder: The above raw materials are mixed, and the mixture is homogenized at 3000 rpm for 5 minutes to obtain a mixture; then the mixture is pumped into a long and narrow pipe and subjected to ultrasonic treatment in the pipe. After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

[0068] The process involved ultrasonic dispersion for 1 minute at a power of 300W to prepare titanium dioxide slurry. The inner diameter of the pipe was 4 mm, the length of the pipe was 25 m, and the volume of the material tank was 80 ml.

[0069] Example 3 A sunscreen powder is provided, prepared according to the following steps: Step S1: Prepare materials: Weigh out 300g of stearic acid and alumina-modified titanium dioxide, 25g of polyglycerol-3 diisostearate, 160g of jojoba seed oil, 15g of polyhydroxystearic acid, and 50g of filtered 1% yeast melanin aqueous solution.

[0070] Step S2: Prepare sunscreen powder: The above raw materials are mixed, and the mixture is homogenized at 3000 rpm for 5 minutes to obtain a mixture; then the mixture is pumped into a long and narrow pipe and subjected to ultrasonic treatment in the pipe. After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

[0071] The process involved ultrasonic dispersion for 10 minutes at a power of 800W to prepare titanium dioxide slurry. The pipe had an inner diameter of 8mm, a length of 30m, and a material tank volume of 80ml.

[0072] Example 4 A sunscreen powder is provided, prepared according to the following steps: Step S1: Prepare materials: Weigh out 300g of stearic acid and alumina-modified titanium dioxide, 25g of polyglycerol-3 diisostearate, 160g of jojoba seed oil, 15g of polyhydroxystearic acid, and 50g of filtered 5wt% yeast melanin aqueous solution.

[0073] Step S2: Prepare sunscreen powder: The above raw materials are mixed, and the mixture is homogenized at 3000 rpm for 5 minutes to obtain a mixture; then the mixture is pumped into a long and narrow pipe and subjected to ultrasonic treatment in the pipe. After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

[0074] The process involved ultrasonic dispersion for 10 minutes at a power of 800W to prepare titanium dioxide slurry. The inner diameter of the pipe was 8 mm, the length of the pipe was 30 m, and the volume of the material tank was 80 ml.

[0075] Example 5 A sunscreen powder is provided, prepared according to the following steps: Step S1: Prepare materials: Weigh out 300g of stearic acid and alumina-modified titanium dioxide, 25g of polyglycerol-3 diisostearate, 160g of jojoba seed oil, 15g of polyhydroxystearic acid, and 50g of filtered 10% yeast melanin aqueous solution.

[0076] Step S2: Prepare sunscreen powder: The above raw materials are mixed, and the mixture is homogenized at 3000 rpm for 5 minutes to obtain a mixture; then the mixture is pumped into a long and narrow pipe and subjected to ultrasonic treatment in the pipe. After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

[0077] The process involved ultrasonic dispersion for 10 minutes at a power of 800W to prepare titanium dioxide slurry. The inner diameter of the pipe was 8 mm, the length of the pipe was 30 m, and the volume of the material tank was 80 ml.

[0078] Comparative Example 1 A sunscreen powder is provided, prepared according to the following steps: Weigh out 300g of stearic acid and alumina-modified titanium dioxide, 25g of polyglycerol-3 diisostearate, 160g of jojoba seed oil, 15g of polyhydroxystearic acid, and 5g of filtered 0.1% yeast melanin aqueous solution. Mix all raw materials to obtain a mixture, and homogenize the mixture at 3000 rpm for 5 min. Prepare a biomimetic titanium dioxide slurry.

[0079] Comparative Example 2 A sunscreen powder is provided, prepared according to the following steps: Weigh out 335g of triethoxyoctylsilane-modified zinc oxide, 50g of polyglycerol-3 diisostearate, 107.5g of jojoba seed oil, 5g of polyhydroxystearic acid, and 2.5g of filtered 0.1% yeast melanin aqueous solution. Mix all raw materials to obtain a mixture, and homogenize the mixture at 3000 rpm for 5 min. Prepare a biomimetic zinc oxide slurry.

[0080] Comparative Example 3 A sunscreen powder is provided, prepared according to the following steps: Weigh out 300g of stearic acid and alumina-modified titanium dioxide, 25g of polyglycerol-3 diisostearate, 160g of jojoba seed oil, 15g of polyhydroxystearic acid, and 5g of filtered 0.1% yeast melanin aqueous solution. Homogenize at 3000 rpm for 5 min. Mix all raw materials to obtain a mixture, and homogenize the mixture at 3000 rpm for 5 min. Then ball mill at 3000 rpm for 1 min.

[0081] Comparative Example 4 A sunscreen powder is provided, prepared according to the following steps: Weigh out 300g of stearic acid and alumina-modified titanium dioxide, 25g of polyglycerol-3 diisostearate, 160g of jojoba seed oil, 15g of polyhydroxystearic acid, and 5g of filtered 0.1% yeast melanin aqueous solution. Mix all raw materials to obtain a mixture, homogenize the mixture at 3000 rpm for 5 min, and then homogenize it under high pressure at 100 MPa for 1 min. Prepare the sunscreen powder paste.

[0082] Application Example 1 This application example provides a sunscreen. The aqueous phase comprises 67.05 parts water, 0.2 parts sodium stearoyl glutamate, 4 parts glycerin, 2 parts butylene glycol, and 0.3 parts xanthan gum. The oil phase comprises 1 part cetearyl alcohol, 1 part polyglycerol-10 myristate, 6.5 parts hydrogenated polyisobutylene, 2 parts polydimethylsiloxane, 0.2 parts tocopheryl acetate, and 12.75 parts of the sunscreen powder provided in Example 1. The low-temperature phase comprises 0.5 parts p-hydroxyacetophenone, 2 parts 1,2-pentanediol, and 0.5 parts 1,2-hexanediol.

[0083] Application Example 2 This application example provides a sunscreen. The aqueous phase comprises 69.8 parts water, 0.2 parts sodium stearoyl glutamate, 4 parts glycerin, 2 parts butylene glycol, and 0.3 parts xanthan gum. The oil phase comprises 1 part cetearyl alcohol, 1 part polyglycerol-10 myristate, 6.5 parts hydrogenated polyisobutylene, 2 parts polydimethylsiloxane, 0.2 parts tocopheryl acetate, and 10 parts of the sunscreen powder provided in Example 2. The low-temperature phase comprises 0.5 parts p-hydroxyacetophenone, 2 parts 1,2-pentanediol, and 0.5 parts 1,2-hexanediol.

[0084] Application Comparative Example 1 This application provides a sunscreen as a comparative example. The aqueous phase comprises 67.05 parts water, 0.2 parts sodium stearoyl glutamate, 4 parts glycerin, 2 parts butylene glycol, and 0.3 parts xanthan gum. The oil phase comprises 1 part cetearyl alcohol, 1 part polyglycerol-10 myristate, 6.5 parts hydrogenated polyisobutylene, 2 parts dimethicone, 0.2 parts tocopheryl acetate, and 12.75 parts of the sunscreen powder provided in Comparative Example 1. The low-temperature phase comprises: 0.5 parts p-hydroxyacetophenone, 2 parts 1,2-pentanediol, and 0.5 parts 1,2-hexanediol.

[0085] Application Comparative Example 2 This application provides a sunscreen as a comparative example. The aqueous phase contains 69.8 parts water, 0.2 parts sodium stearoyl glutamate, 4 parts glycerin, 2 parts butylene glycol, and 0.3 parts xanthan gum. The oil phase contains 1 part cetearyl alcohol, 1 part polyglycerol-10 myristate, 6.5 parts hydrogenated polyisobutylene, 2 parts polydimethylsiloxane, 0.2 parts tocopheryl acetate, and 10 parts of the sunscreen powder provided in Comparative Example 2. The low-temperature phase contains: 0.5 parts p-hydroxyacetophenone, 2 parts 1,2-pentanediol, and 0.5 parts 1,2-hexanediol.

[0086] Performance testing 1. The microstructure of the sunscreen powder provided in the examples and comparative examples was analyzed. The test results are shown in the appendix to the instruction manual. Figure 1 -Instruction manual included Figure 4 .

[0087] Included in the instruction manual Figure 1 and attached Figure 2 As can be seen from the microstructure of the sunscreen powder provided in Example 1, the particle size of the sunscreen powder in Example 1 is significantly smaller and more uniform than that of the sunscreen powder in Comparative Example 1. The sunscreen powder in Comparative Example 1 exhibits localized agglomeration, and its overall particle size is also larger. The average particle size of the sunscreen powder in Comparative Example 1 is greater than 500 nm. The average particle size of the sunscreen powder in Example 1 is 100 nm to 380 nm.

[0088] Included in the instruction manual Figure 3 and4 As can be seen from the microstructure of the sunscreen powder provided in Example 2, the particle size of the sunscreen powder in Example 2 is significantly smaller and more uniform than that of the sunscreen powder in Comparative Example 2. The sunscreen powder in Comparative Example 2 exhibits localized agglomeration, and its overall particle size is also larger. The average particle size of the sunscreen powder in Comparative Example 2 is greater than 500 nm. The average particle size of the sunscreen powder in Example 2 is 100 nm to 380 nm.

[0089] The sunscreen powder has a particle size in the range of 100nm to 380nm. The particle size is much smaller than the wavelength of visible light (400-700nm), which reduces the scattering of visible light and thus significantly reduces the "fake white" feeling, making the skin feel more natural and transparent.

[0090] 2. Material performance tests on the sunscreen powder provided in the examples and comparative examples.

[0091] (1) The samples from Examples 1 and 2, as well as Comparative Examples 1 and 2, were placed in transparent sample vials and incubated at 45°C for 30 days. The layering phenomenon was observed and recorded. The test results are shown in Table 1 and the instruction manual. Figure 5-6 .

[0092] Included in the instruction manual Figure 5 It can be seen that the sunscreen powder of Example 1 did not show any stratification after being placed in a constant temperature chamber at 45℃ for 30 days; while the sunscreen powder of Comparative Example 1 showed severe stratification after being placed in a constant temperature chamber at 45℃ for 30 days.

[0093] Included in the instruction manual Figure 6 It can be seen that the sunscreen powder of Example 2 did not show any stratification after being placed in a constant temperature chamber at 45℃ for 30 days; while the sunscreen powder of Comparative Example 2 showed severe stratification after being placed in a constant temperature chamber at 45℃ for 30 days.

[0094] (2) The sunscreen powder samples of Examples 1-5 and Comparative Examples 1-4 were centrifuged at 5000 rpm for 15 min and the stratification was tested. The test results are shown in Table 1.

[0095] (3) At 25°C and a shear rate of 10 s -1 Under the specified conditions, the viscosity of the sunscreen powder samples from Examples 1-5 and Comparative Examples 1-4 was tested. The test results are shown in Table 1.

[0096] Table 1

[0097] As can be seen from the data in Table 1 above: The sunscreen powder in the example showed no stratification after centrifugation at 5000 rpm for 15 minutes; however, the sunscreen powder in the comparative example showed stratification. This demonstrates that the powder is highly dispersed and free of agglomeration, indicating that the sunscreen powder in this embodiment has superior dispersion and is free of agglomeration. When the non-agglomerated powder is coated into a uniform film, its scattering of visible light is controllable and natural, thereby minimizing or eliminating the "fake white" appearance to the greatest extent possible.

[0098] Furthermore, at 25°C and a shear rate of 10 s... -1 Under the specified conditions, the viscosity of the sunscreen powder in the examples is 5000 mPa·s to 50000 mPa·s. This suitable viscosity ensures that the sunscreen powder maintains its dispersed state during storage and forms a uniform film upon use. In contrast, the comparative sunscreen powders with excessively low or high viscosities exhibit significantly lower performance compared to this application.

[0099] 3. The sun protection performance of the sunscreens provided in the application examples and application comparison examples was tested.

[0100] Test method: This experiment used a UV2000S to test the SPF values ​​of the application examples and comparative examples: (1) Instrument warm-up and initialization: Turn on the UV2000S and computer, and warm up the instrument for at least 30 minutes to allow it to reach a stable state. Start the operating software.

[0101] (2) PMMA board pretreatment: Take a new or thoroughly cleaned and dried PMMA plate. Gently wipe the surface of the plate with a small amount of solvent to ensure it is clean, dust-free, and fingerprint-free. Allow it to air dry.

[0102] (3) Baseline calibration: Place a clean PMMA plate (without any sample coating) into the sample holder.

[0103] Select "Baseline Calibration" in the software to perform calibration.

[0104] (4) Sample preparation: Using an analytical balance, accurately weigh the calculated sample amount into the center of the PMMA plate.

[0105] (5) Coating: Using fingertips or a special coating stick, apply light and even pressure to quickly and evenly coat the sample on the entire plate surface in a circular or straight motion. This method requires high operator skill and is prone to errors.

[0106] (6) Drying / film formation: Place the coated PMMA plate in a dark, room temperature (e.g., 25±1°C) environment with constant humidity for 15-20 minutes to allow the sunscreen product to fully form a film, evaporate the solvent, and stabilize its state.

[0107] (7) Measurement: Carefully place the prepared PMMA plate into the sample holder of the instrument, ensuring that the plate surface is facing the light path. After setting the parameter wavelength range to 290nm-400nm, measure at least 3 different positions on each plate to avoid errors caused by uneven local coating, and calculate the SPF value using software.

[0108] Test results are attached to the instruction manual. Figure 7 Included with instruction manual Figure 8 .

[0109] The SPF value of Application Example 1 is 48.38, while the SPF value of Application Comparative Example 1 is 21.55, representing a 125% improvement in sun protection performance.

[0110] The SPF value of Application Example 2 is 40.25, while the SPF value of Application Comparative Example 2 is 18.22, representing a 121% improvement in sun protection performance.

[0111] In summary, it can be seen that the application examples containing the sunscreen powder prepared in the embodiments of this application have significantly higher SPF values ​​than the application comparative examples using the comparative powder, with a sun protection performance improvement of 121% to 125%, proving that the method of this application can effectively improve the sun protection effect of the product.

[0112] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A sunscreen powder, characterized in that, The sunscreen powder includes: Yeast melanin solution, sunscreen powder, dispersant, emulsifier and oil; Wherein, by mass percentage, the yeast melanin solution accounts for 0.00001% to 10% of the sunscreen powder; the sunscreen powder accounts for more than 50% of the sunscreen powder. The sunscreen powder includes any one of unmodified titanium dioxide, modified titanium dioxide, unmodified zinc oxide, or modified zinc oxide; The average particle size of the sunscreen powder in the sunscreen paste is 100nm~380nm.

2. The sunscreen powder according to claim 1, characterized in that, The yeast melanin solution accounts for 0.1% to 10% of the sunscreen powder by weight percentage; Optionally, the sunscreen powder accounts for 50% to 80% of the sunscreen paste by weight percentage.

3. The sunscreen powder according to claim 1, characterized in that, After centrifugation at 5000 rpm for 15 minutes, the sediment volume of the sunscreen powder was less than 1% of the total volume. Optionally, at 25°C and a shear rate of 10 s... -1 Under these conditions, the viscosity of the sunscreen powder is 5000 mPa·s ~ 50000 mPa·s.

4. The sunscreen powder according to claim 1, characterized in that, The modified titanium dioxide includes at least one of the following: alumina-modified titanium dioxide, aluminum hydroxide-modified titanium dioxide, silica-modified titanium dioxide, stearic acid-modified titanium dioxide, triethoxyoctylsilane-modified titanium dioxide, polymethylsiloxane-modified titanium dioxide, polydimethylsiloxane-modified titanium dioxide, isopropoxytitanium triisostearate-modified titanium dioxide, stearoylglutamic acid-modified titanium dioxide, magnesium myristate-modified titanium dioxide, jojoba ester-modified titanium dioxide, lecithin-modified titanium dioxide, or hydrogenated lecithin-modified titanium dioxide.

5. The sunscreen powder according to claim 1, characterized in that, The modified zinc oxide includes at least one of the following: stearic acid modified zinc oxide, triethoxyoctylsilane modified zinc oxide, polymethylsiloxane modified zinc oxide, polydimethylsiloxane modified zinc oxide, triisostearate isopropoxytitanium triisostearate modified zinc oxide, stearoylglutamic acid modified zinc oxide, magnesium myristate modified zinc oxide, jojoba ester modified zinc oxide, lecithin modified zinc oxide, or hydrogenated lecithin modified zinc oxide.

6. The sunscreen powder according to any one of claims 1-5, characterized in that, The dispersant includes at least one of the following: polyhydroxystearic acid, organobentonite, fumed silica, cetearyl alcohol, polyglycerol esters, or acrylates.

7. The sunscreen powder according to any one of claims 1-5, characterized in that, The emulsifier includes at least one of polyglycerol-3 diisostearate, sorbitan oleate, sorbitan sesquioleate, or polyglycerol-6 polyricinoleate. Optionally, the oil includes one or more of the following: isononyl isononanoate, jojoba seed oil, sunflower seed oil, caprylic / capric triglyceride, isododecane, or C12-15 benzoic acid ester oil.

8. The method for preparing sunscreen powder according to any one of claims 1-7, characterized in that, include: Yeast melanin, sunscreen powder, dispersant, emulsifier and oil are mixed to obtain a mixture; The mixture is pumped into a long, narrow pipe, and the mixture in the pipe is subjected to ultrasonic treatment; After passing through the pipeline, the mixture enters the material pool; The mixed particles arriving at the material pool are broken down to their original particle size.

9. The method for preparing sunscreen powder according to claim 8, characterized in that, include: The inner diameter of the pipe is 4mm-8mm; optionally, the length of the pipe is 20m or more. Optionally, the ultrasonic power is 300W-800W; Optionally, the volume of the material pool is 40ml-80ml; Optionally, the duration of the ultrasound is 1 min to 10 min.

10. A sunscreen cosmetic, characterized in that, Includes the sunscreen powder as described in any one of claims 1-7; Optionally, the amount of sunscreen powder added to the sunscreen cosmetic is 1wt% to 25wt%.

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