Sunscreen cosmetic composition and preparation method thereof

Abstract

The present invention discloses a sunscreen cosmetic composition and a preparation method thereof. The sunscreen cosmetic comprises the following components: 20-60 parts of a physical sunscreen, 0-30 parts of a chemical sunscreen, 0.01-1 parts of an antioxidant, 5-20 parts of oil, 5-15 parts of a moisturizer, 1-5 parts of an emulsifier, 10-30 parts of anhydrous ethanol, and 0.1-3 parts of other additives. The physical sunscreen comprises a multifaceted nano-zinc oxide core, angular nano-zinc oxide with epitaxial extension on the surface, and the multifaceted nano-zinc oxide and the angular nano-zinc oxide are coated with a multilayer SiO2 / TiO2 periodic structure to form a core-shell structure in which a total reflection film covers the zinc oxide core. The core-shell structure of the present invention achieves ultraviolet light attenuation through the multiple functions of reflection, absorption, and scattering. The angular nano-zinc oxide structure not only improves the exit angle to facilitate light reflection, but also increases the apparent diameter of the nanospheres, reducing the probability of nanopowder penetration into the skin, thereby improving the biotoxicity of the sunscreen product.

Description

Technical Field

[0001] The present invention belongs to the technical field of isolation preparations, and in particular relates to a sunscreen cosmetic composition and a preparation method thereof. Background Art

[0002] Ultraviolet (UV) radiation is the main cause of skin cancer and can also cause erythema and photoaging. Photoprotection is used to protect the skin from the negative effects of these UV radiations, and sunscreen is an important part of the photoprotection strategy.

[0003] Existing sunscreen methods are divided into two categories: physical (inorganic) and chemical (organic). Organic sunscreens, however, are harmful to the environment due to their energy-absorbing chemicals, particularly damaging coral reefs. They can also leach residue into water systems and aquatic animals. For those with sensitive skin, these chemicals can also easily cause allergic reactions. Therefore, inorganic sunscreens have become a mainstream research direction.

[0004] Currently, there are two types of inorganic sunscreens that are recognized and approved. Titanium dioxide and zinc oxide play a photoprotective role by absorbing, reflecting and refracting ultraviolet photons, but mainly by absorbing ultraviolet radiation. The sun protection effect can reach SPF50. However, too thick a coating will leave a white chalky appearance on the skin, which is particularly obvious in individuals with dark skin and is not conducive to aesthetics. Therefore, how to balance sun protection and aesthetics is an important research direction in the industry. In order to achieve this effect, the existing technology mostly uses shell-core structure sunscreens, in which the shell is an organic material, which wraps the inorganic nanocore, and multiple combinations are used to exert the ultraviolet absorption function, thereby reducing the amount of inorganic sunscreen used or improving the shortcomings of using a single inorganic core material. There is also a design in which the outer shell is inorganic and the inner shell is organic. A brief description of the existing technology in the corresponding field is as follows:

[0005] CN201310046158.8 modifies the surface of titanium dioxide core with hyaluronic acid gel to increase the moisturizing and affinity of the skin.

[0006] CN202011445169.X uses titanium dioxide as the outer shell, and a chitosan three-dimensional network polymer chain grafted with 2-hydroxybenzophenone with ultraviolet absorption ability is placed in the inner cavity to achieve the effects of increasing the ultraviolet path in the inner cavity and dual absorption of organic sunscreens.

[0007] CN202210020016.3 adopts the structure of nano ZnO@zinc borate@guar gum composite gel to achieve multiple sun protection functions. The preparation of zinc borate meets the requirements of high sun protection level.

[0008] CN202110362354.0 uses commercial physical sunscreen zinc oxide and titanium dioxide nanoparticles as the core and natural polyphenol resveratrol functionalized polyphosphazene as the coating layer to form a core-shell structure, which avoids direct contact between the inorganic core with active groups and the skin, while providing the sun protection effect of natural sunscreen.

[0009] CN201110226078.1 adopts a composite material structure consisting of titanium dioxide and zinc oxide, with zinc oxide as the core and titanium dioxide as the shell, which enhances the dispersion ability of nano zinc oxide.

[0010] CN201710472702.3 uses numerous nano-scale sunscreen particles as the outer layer to wrap a micron-scale carrier microsphere. This structure gives the hybrid microsphere a concave-convex surface that reflects and scatters light, increasing the surface area of ​​the microsphere. The outer layer of sunscreen particles can also be used to absorb ultraviolet rays. It is a hybrid microsphere with both physical and chemical sunscreen effects.

[0011] There are also inorganic-inorganic shell-core structures, organic-organic shell-core structures, etc., in order to achieve multiple sun protection functions.

[0012] The design of sunscreens with various functions on the market shows the huge potential of the core-shell structure. Therefore, based on this, the present invention further improves the use effect in related fields to meet various usage needs. Summary of the Invention

[0013] In response to the problems in the related art, the present invention proposes a lightweight insulating column and a preparation method thereof to overcome the above-mentioned technical problems existing in the existing related art.

[0014] The technical solution of the present invention is achieved by using nano-zinc oxide microspheres as cores, improving the surface crystal plane preferential orientation by annealing the microspheres to form a polyhedron, and preparing a DBR total reflection structure on the polyhedron, thereby enhancing the total reflection ability of UVA and UVB ultraviolet rays. A further solution is based on the polyhedron with preferential crystal plane orientation, introducing a nano-silver lattice mismatch mechanism, further epitaxially extending angular nano-zinc oxide, and covering it with a DBR total reflection structure to prepare an optical structure with incident angle constraint, which is used to reduce the transmittance of axial incident light and enhance the output rate of reflected light, thereby reducing the amount of ultraviolet damage to the skin. The specific invention content is as follows:

[0015] A sunscreen cosmetic composition comprises the following components: 20-60 parts of a physical sunscreen, 0-30 parts of a chemical sunscreen, 0.01-1 parts of an antioxidant, 5-20 parts of oil, 5-15 parts of a moisturizer, 1-5 parts of an emulsifier, 10-30 parts of anhydrous ethanol, and 0.1-3 parts of other additives.

[0016] Preferably, the physical sunscreen comprises polyhedral nano zinc oxide microspheres as cores, which are coated with a multilayer SiO2@TiO2 periodic structure to form a core-shell structure in which a total reflection film coats the zinc oxide core.

[0017] More preferably, the thickness of the SiO2 single layer is 20-40 nm, the thickness of the TiO2 single layer is 10-30 nm, and the particle size of the polyhedral nano-zinc oxide microspheres is 50-70 nm.

[0018] More preferably, the optical refractive index of the SiO 2 is less than 1.55, forming a light-reducing medium with a periodic structure.

[0019] More preferably, the optical refractive index of the TiO2 is greater than or equal to 2.50, forming an optically dense medium with a periodic structure.

[0020] More preferably, the optical refractive index of the zinc oxide is 1.9 to 2.1, forming an ultraviolet absorbing core.

[0021] Preferably, a nano-silver quantum dot defect layer is prepared on the surface of the polyhedral nano-zinc oxide microspheres, and angular nano-zinc oxide is epitaxially grown on the defect layer, and then coated with a multi-layer SiO2 / TiO2 periodic structure.

[0022] Preferably, the chemical sunscreen is one or more of a UVA sunscreen and a UVB sunscreen.

[0023] More preferably, the UVA sunscreen is composed of one or more of bis-ethylhexyloxyphenol methoxyphenyl triazine, butyl methoxydibenzoylmethane, diethylamino hydroxybenzoyl hexyl benzoate, and butyl methoxybenzophenone, and the UVB sunscreen is composed of one or more of phenylbenzimidazole sulfonic acid, ethylhexyl salicylate, octyl salicylate, ethylhexyl methoxycinnamate, octyl dimethyl para-aminobenzoate, homosalate, polysiloxane, and octyl triazone.

[0024] Preferably, the antioxidant is one or more of propylparaben, methylparaben, phenoxyethanol, benzyl alcohol, bis(hydroxymethyl)imidazolidinyl urea, and iodopropynyl butylcarbamate.

[0025] Preferably, the oil is composed of one or more of dicaprylyl carbonate, dipropylene glycol dibenzoate, octyl polymethylsiloxane, cyclopentasiloxane, and tridecyl stearate.

[0026] Preferably, the moisturizing agent is composed of one or more of glycerin, propylene glycol, butylene glycol, betaine, panthenol, and sodium hyaluronate.

[0027] Preferably, the emulsifier is composed of one or more of glyceryl stearate, polyglyceryl-3 diisostearate, cetearyl glucoside, and sorbitan olivate.

[0028] Preferably, the other additives are one or more of a soothing agent, an anti-allergic agent, a complexing agent, a cross-linking agent, and a fragrance.

[0029] More preferably, the optical refractive index of the chemical sunscreen, antioxidant, oil, moisturizer, emulsifier and other additives is less than 1.55.

[0030] More preferably, the refractive index of the outermost shell layer in step S4 is greater than the refractive index of other components of the cosmetic composition.

[0031] More preferably, the final shell material in step S4 is TiO2.

[0032] This solution also discloses a method for preparing a sunscreen cosmetic composition, comprising the following steps:

[0033] S1: Synthesize nano-ZnO microspheres by hydrothermal method, and form polyhedral nano-ZnO microspheres by high temperature annealing in inert gas;

[0034] S2: hydrothermal coating of SiO2 to form ZnO@SiO2 composite nanoparticles;

[0035] S3: Hydrothermal coating of TiO2 to form ZnO@SiO2@TiO2 composite nanoparticles;

[0036] S4: Repeat steps S2 and S3 to form ZnO@DBR composite nanoparticles with a SiO2 / TiO2 composite layer having a stacking period greater than 2;

[0037] S5: 20-60 parts of ZnO@DBR composite nanoparticles as a physical sunscreen are mixed with 0-30 parts of a chemical sunscreen, 0.01-1 part of an antioxidant, 5-20 parts of oil, 5-15 parts of a moisturizer, 1-5 parts of an emulsifier, 10-30 parts of anhydrous ethanol, and 0.1-3 parts of other additives to prepare a sunscreen cosmetic composition.

[0038] Preferably, the zinc source used in step S1 is one or more of zinc nitrate, zinc acetate and zinc chloride.

[0039] More preferably, the molar concentration ratio of the ingredients used in the hydrothermal method is zinc nitrate hexahydrate: triethanolamine = 2:1, and deionized water is used as the solvent.

[0040] More preferably, the hydrothermal reaction temperature of the nano zinc oxide microspheres is 150-180° C., and the reaction time is 2-4 hours.

[0041] More preferably, the nano zinc oxide microspheres are annealed and calcined at 400-600° C. for 2-3 hours in an inert atmosphere to prepare polyhedral nano zinc oxide microspheres.

[0042] More preferably, the inert atmosphere is N2.

[0043] Preferably, the silicon source used in step S2 is one or more of tetraethyl orthosilicate, rice husk ash, and water glass.

[0044] More preferably, the silicon source is tetraethyl orthosilicate.

[0045] More preferably, the molar concentration ratio of the ingredients used in the hydrothermal method is polyhedral nano zinc oxide microspheres: tetraethyl orthosilicate: concentrated ammonia water = 40-60: 1-3: 4-8, and isopropyl alcohol is used as the solvent.

[0046] More preferably, KH550 silane coupling agent is used to disperse the polyhedral nano zinc oxide microspheres during the hydrothermal synthesis process.

[0047] More preferably, the hydrothermal reaction temperature is 120-140° C., and the reaction time is 1-2 h.

[0048] More preferably, a water bath at 40-50° C. is used to homogenize the solutions during the hydrothermal synthesis process.

[0049] Preferably, the titanium source used in step S3 is one or more of tetrabutyl titanate, titanium tetrachloride, and titanium sulfate.

[0050] More preferably, the titanium source is tetrabutyl titanate.

[0051] More preferably, the hydrothermal reaction adopts a molar concentration ratio of ZnO@SiO2 composite nanoparticles: tetrabutyl titanate: diethanolamine = 40-60:3-6:1-2, and anhydrous ethanol is used as the solvent.

[0052] More preferably, the hydrothermal method uses anhydrous ethanol as the solution, and the homogenization stirring time is 60 to 90 minutes.

[0053] More preferably, the hydrothermal reaction temperature is 180-200° C., and the reaction time is 2-4 h.

[0054] Preferably, the step S4 repeats the steps S2 and S3 to form a SiO2 / TiO2 total reflection shell layer with a superposition period greater than 2.

[0055] More preferably, the period is 2 to 4 groups, and the total thickness does not exceed 400 nm.

[0056] Preferably, between step S1 and step S2, the following steps are further included:

[0057] S1-1: Preparation of silver nanoparticles by hydrothermal method on the surface of polyhedral nano-ZnO microspheres to prepare lattice-mismatched growth surfaces;

[0058] S1-2: hydrothermally growing angular nano-ZnO columns on the growth surface.

[0059] Preferably, in step S1-1, the nanosilver quantum dots are prepared by hydrothermal synthesis, using silver nitrate as the silver source.

[0060] More preferably, the hydrothermal reaction adopts a molar concentration ratio of polyhedral nano zinc oxide microspheres: silver nitrate: hexadecyltrimethylammonium bromide: PVP = 40-60:0.4-1:3-6:10:15, and ethylene glycol is used as the solvent.

[0061] More preferably, the dripping rate of the PVP ethylene glycol solution is 0.3-0.5 ml / min.

[0062] More preferably, the hydrothermal reaction temperature is 150-170° C., and the reaction time is 60-90 min.

[0063] More preferably, the silver nanoparticles are attached to the surface of the polyhedral zinc oxide nanoparticles in a discrete manner.

[0064] Preferably, the zinc source used in step S1-2 is one or more of zinc nitrate, zinc acetate and zinc chloride.

[0065] More preferably, the molar concentration ratio of the ingredients used in the hydrothermal method is quantum dot composite nanoparticles: zinc nitrate hexahydrate: hexamethylenetetramine: ethylenediamine = 10-15: 5-7: 7-9: 10-15, and deionized water is used as the solvent.

[0066] More preferably, the hydrothermal reaction temperature of the nano zinc oxide microspheres is 90-110° C., and the reaction time is 2-3 hours.

[0067] More preferably, the ingredients are homogenized in a solvent by ultrasonic vibration.

[0068] More preferably, the angular nano-zinc oxide column crystal growth orientation is (0001) plane.

[0069] Beneficial effects of the present invention:

[0070] Compared with the existing technology, the present invention forms a polyhedron by preferentially processing the crystal orientation of nano-zinc oxide microspheres. Based on the plane characteristics of the polyhedron, a DBR total reflection structure is prepared to enhance the reflection ability of UVA and UVB ultraviolet rays. Part of the transmitted light is bound by the DBR total reflection structure in the zinc oxide microsphere core, and the absorption capacity of the nano-zinc oxide microspheres is utilized to further complete the treatment of ultraviolet rays.

[0071] Furthermore, the present invention improves the emission angle of ultraviolet rays, increases the emission rate, and reduces the penetration rate by introducing an angular nano-zinc oxide structure.

[0072] Furthermore, the angular nano-zinc oxide structure introduced in the present invention increases the particle size of the nano-microspheres, thereby reducing the probability of biological toxicity damage caused by penetrating the skin.

[0073] Ultimately, on the basis of improving the ability to reflect, absorb and scatter ultraviolet rays, the use of physical sunscreens can be reduced and the white spot effect of cosmetics can be weakened. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0075] Figure 1 This is a SEM image of the nano-zinc oxide microspheres prepared in Example 1 of the present invention before calcination.

[0076] Figure 2 This is a SEM image of the nano zinc oxide microspheres prepared in Example 1 of the present invention after calcination.

[0077] Figure 3 This is a theoretical schematic diagram of the structure of nano zinc oxide microspheres prepared in Example 1 of the present invention.

[0078] Figure 4 This is the SEM image of the composite nanoparticles prepared in Example 2 of the present invention.

[0079] Figure 5 This is a theoretical schematic diagram of the structure of nano zinc oxide microspheres prepared in Example 2 of the present invention.

[0080] Figure 6 Ultraviolet reflectance spectra of the ZnO@DBR composite nanoparticles and the spiny spherical ZnO@DBR composite nanoparticles prepared in Example 1 of the present invention.

[0081] Among them, 1 is a polyhedral nano zinc oxide microsphere, 2 is the first SiO2 shell layer, 3 is the second TiO2 shell layer, 4 is the Nth SiO2 shell layer, 5 is the Nth TiO2 shell layer, 6 is a mixed layer of other cosmetic components, 7 is a nano silver quantum dot defect layer, and 8 is an angular nano zinc oxide column. DETAILED DESCRIPTION

[0082] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The process parameters for which specific conditions are not specified in the following examples are generally in accordance with conventional conditions.

[0083] The endpoints of the ranges and any values ​​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 endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed in the present invention.

[0084] Example 1, preparation of a sunscreen cosmetic composition, comprising the following steps:

[0085] S1: Preparation of polyhedral nano-zinc oxide microspheres. A 0.2 mol / L zinc nitrate hexahydrate solution was completely dissolved in deionized water by stirring. Then, 0.15 mol / L triethanolamine was slowly added dropwise while stirring to obtain a precursor solution A. Precursor solution A was transferred to an autoclave and reacted at 160°C for 3 h. The reaction was allowed to cool naturally to room temperature. The precipitate was filtered, washed, and dried. The solution was then annealed in a resistance furnace at 450°C for 2 h to prepare polyhedral nano-zinc oxide microspheres with a particle size of 50-60 nm.

[0086] S2: Preparation of SiO2-coated polyhedral nano-zinc oxide microspheres. 0.3 mol / L polyhedral nano-zinc oxide microspheres and 0.03 mol / L silane coupling agent KH550 were added to 0.6 mol / L isopropanol, and placed in a 40°C water bath, stirred and mixed evenly, and 10 mol / L deionized water, 0.03 mol / L concentrated ammonia water, and 0.01 mol / L tetraethyl orthosilicate were added in sequence, and stirred evenly at 40°C to obtain precursor solution B. Precursor solution B was transferred to a high-pressure reactor, reacted at 120°C for 1 hour, and naturally cooled to room temperature. The precipitate was filtered, washed, and dried to obtain ZnO@SiO2 composite nanoparticles with an average shell thickness of 35 nm.

[0087] S3: Preparation of TiO2-coated ZnO@SiO2 composite nanoparticles. 0.01mol / L diethanolamine, 0.2mol / L ZnO@SiO2 composite nanoparticles, and 0.0153mol / L tetrabutyl titanate were added to 0.5mol / L anhydrous ethanol and stirred to dissolve the tetrabutyl titanate. The precursor solution C was obtained after continuing stirring for 60min. The precursor solution C was transferred to a high-pressure reactor and reacted at 180℃ for 4h. The solution was naturally cooled to room temperature. The precipitate was filtered, washed, and dried to obtain ZnO@SiO2@TiO2 composite nanoparticles with an average shell thickness of 25nm.

[0088] S4: The SiO2@TiO2 shell layer formed by a single S2 and S3 is regarded as one group. Steps S2 and S3 are repeated to form three groups of SiO2 / TiO2 composite layers. The outermost shell layer is a TiO2 layer, and the total shell thickness of the ZnO@DBR composite nanoparticles is 120nm. The particle size of the ZnO@DBR composite nanoparticles is 230nm~250nm.

[0089] S5: First, mechanically stir and mix 3 parts of glyceryl stearate, 10 parts of glycerin, and 20 parts of anhydrous ethanol. Then, add 15 parts of dicaprylyl carbonate, 8 parts of bis-ethylhexyloxyphenol methoxyphenyl triazine, and 8 parts of ethylhexyl methoxycinnamate. Finally, add 40 parts of ZnO@DBR composite nanoparticles and 0.5 parts of aloe vera soothing agent. Use a planetary vacuum mixer to complete the homogenization of the inorganic nanoparticles.

[0090] The filling degree in the autoclave used for the preparation in this embodiment is 60%. The prepared ZnO is wurtzite-type, with a refractive index of 1.9-2.0 and a particle size of 50-60 nm. The prepared SiO2 is α-quartz, with a refractive index of 1.54-1.55, a thickness of 30-40 nm, and an average of 35 nm. The prepared TiO2 layer is anatase-type, with a refractive index of 2.45-2.55, a thickness of 20-30 nm, and an average of 25 nm. The refractive index of the aloe vera soothing agent used is less than 1.5.

[0091] Figure 1is the SEM image of the microspheres before annealing. Figure 2 The SEM image of the microspheres after annealing is shown in Figure 3. Annealing causes crystal regrowth, thereby weakening the macroscopic defects on the microsphere surface caused by lattice mismatch and dislocations.

[0092] Figure 3 This is a schematic diagram of the theoretical structure of this embodiment. The final structure is 1: polyhedral nano-zinc oxide microspheres, 2: the first SiO2 shell layer, 3: the second TiO2 shell layer, 4: the third SiO2 shell layer, 5: the third TiO2 shell layer, and 6: a mixed layer of other cosmetic components. The equivalent DBR structure of the UV path is a four-fold structure, with some UV rays being reflected by the DBR structure and some entering the ZnO core and being absorbed. This structure filters UV rays between 310 and 400 nm (see [1]). Figure 6 polyhedral lines).

[0093] Example 2, preparation of a sunscreen cosmetic composition, comprising the following steps:

[0094] S1: Preparation of polyhedral nano-zinc oxide microspheres. A 0.4 mol / L zinc nitrate hexahydrate solution was completely dissolved in deionized water by stirring, and then 0.2 mol / L triethanolamine was slowly added dropwise while stirring to obtain a precursor solution A. The precursor solution A was transferred to a high-pressure reactor and reacted at 180°C for 4 hours. The reaction was allowed to cool naturally to room temperature, and the precipitate was filtered, washed, and dried. The precipitate was then calcined in a resistance furnace at 500°C for 2.5 hours to prepare polyhedral nano-zinc oxide microspheres with a particle size of 60-70 nm.

[0095] S1-1: Preparation of silver nanoparticles on the surface of polyhedral nano-zinc oxide microspheres. Prepare an ethylene glycol solution D containing 0.3 mol / L polyhedral nano-zinc oxide microspheres, 0.005 mol / L silver nitrate, and 0.03 mol / L hexadecyltrimethylammonium bromide. Add 0.05 mol / L PVP ethylene glycol solution E dropwise into solution D at a rate of 0.3 ml / min. After the addition is complete, the solution turns dark brown to obtain a precursor solution F. Place the precursor solution F in an autoclave at 160°C for 70 minutes, filter, wash, and dry to prepare a polyhedral nano-zinc oxide microsphere-attached silver nanoparticle structure, which is defined as a quantum dot composite nanoparticle.

[0096] S1-2: Preparation of angular zinc oxide nanoparticles. A deionized water solution containing 0.075 mol / L quantum dot composite nanoparticles, 0.035 mol / L zinc nitrate, and 0.045 mol / L hexamethylenetetramine was prepared under ultrasonic vibration and stirred for 30 minutes. Then, a deionized water solution of 0.05 / L ethylenediamine was slowly added dropwise to form a precursor solution G. This precursor solution G was placed in an autoclave and reacted in a 100°C water bath for 2 hours. The mixture was then filtered, washed, and dried to form angular zinc oxide nanospheres.

[0097] S2: SiO2-coated angular zinc oxide nanospheres. 0.2 mol / L angular zinc oxide nanospheres and 0.03 mol / L silane coupling agent KH550 were added to 0.8 mol / L isopropanol and placed in a 50°C water bath. Stirring was continued until uniform. 14 mol / L deionized water, 0.04 mol / L concentrated ammonia water, and 0.015 mol / L tetraethyl orthosilicate were added in sequence. Stirring was continued at 40°C to obtain precursor solution B. Precursor solution B was transferred to a high-pressure reactor and reacted at 140°C for 2 hours. The reaction was allowed to cool naturally to room temperature. The precipitate was filtered, washed, and dried to obtain ZnO@SiO2 composite nanoparticles with a coating shell thickness of 20 to 40 nm.

[0098] S3: ZnO@SiO2 composite nanoparticles prepared by TiO2 coating S2. 0.01mol / L diethanolamine, 0.3mol / L ZnO@SiO2 composite nanoparticles, and 0.02mol / L tetrabutyl titanate were added to 0.5mol / L anhydrous ethanol, stirred to dissolve the tetrabutyl titanate, and stirred for 90 minutes to obtain precursor solution C. The solution was transferred to a high-pressure reactor and reacted at 190°C for 3 hours. The solution was naturally cooled to room temperature, and the precipitate was filtered, washed, and dried to obtain ZnO@SiO2@TiO2 composite nanoparticles with a coating shell thickness of 10 to 30nm.

[0099] S4: Taking the SiO2@TiO2 shell layer formed by a single S2 and S3 as one group, repeat the S2 and S3 steps to form two groups of SiO2 / TiO2 composite layers, with the outermost shell layer being the TiO2 layer, to form spherical ZnO@DBR composite nanoparticles with a total shell thickness of 120 nm and a particle size of 300 nm to 350 nm.

[0100] S5: First, mechanically stir and mix 5 parts of sorbitan olivate, 10 parts of sodium hyaluronate, and 30 parts of anhydrous ethanol. Then add 15 parts of octyl polymethylsiloxane, 5 parts of butyl methoxybenzophenone, and 5 parts of octyl salicylate. Finally, add 30 parts of ZnO@DBR composite nanoparticles, 1 part of aloe vera soothing agent, and 0.5 parts of composite plant anti-allergic agent. Use a planetary vacuum mixer to complete the homogenization of the inorganic nanoparticles.

[0101] The filling degree in the autoclave used for the preparation of the present embodiment is 70%. The ZnO prepared is wurtzite-type, has a refractive index of 1.9 to 2.0, and a particle size of 50 to 60 nm. The SiO prepared is α-quartz, has a refractive index of 1.54 to 1.55, and a thickness of 20 to 40 nm. The TiO prepared is anatase-type, has a refractive index of 2.50 to 2.55, and a thickness of 10 to 30 nm. The thickness distribution range of SiO and TiO is relatively large because the surface of the angular nano zinc oxide column and the surface of the polyhedron nano zinc oxide microsphere have different crystal orientation preference levels. The surface of the polyhedron nano zinc oxide microsphere is more suitable for planar growth, and is therefore thicker and more suitable for UVA reflection. The shell layer on the surface of the angular nano zinc oxide column covers a thinner layer, thereby being more suitable for UVB reflection.

[0102] In step S1-1, the silver nanoparticles are discretely attached to the surface of the polyhedral zinc oxide nanospheres, forming seed planes for lattice mismatch and epitaxial growth sites, providing a foundation for the (0001) plane-preferred orientation growth of angular zinc oxide nanoparticles. Hexadecyltrimethylammonium bromide enhances the surface adhesion of the silver nanoparticles at low concentrations.

[0103] The increased concentration of zinc nitrate in step S1-2 affects whether the corners of the angular nano-zinc oxide are sharp or flat. The corner length is 150-180 nm, and the root width is 20-30 nm. The crystal growth orientation is the (0001) plane. Hexagonal wurtzite-structured zinc oxide crystals are generally composed of two crystal planes with different properties: two chemically active polar planes (0001) and (0001̅), and six chemically stable non-polar planes. Due to the presence of the polar axis, zinc oxide crystals are usually mainly columnar or conical crystals growing along the c-axis. The hydrothermal solvothermal method is a simple and effective method for controlling the microscopic morphology of zinc oxide crystals.

[0104] Figure 4 This is an SEM image of the composite nanoparticles of this example. It can be seen that the angular nano-zinc oxide pillars significantly exceed the polyhedral nano-zinc oxide microsphere shell. The angular protrusions act as optical structures, increasing the incident surface area and effectively increasing the incident angle of small-angle incident light, thereby improving reflection efficiency. At the same time, they effectively reduce the exit angle of the fully emitted light from the microsphere after incident.

[0105] Figure 5 This is a schematic diagram of the theoretical structure of this embodiment. Finally, 1 is a polyhedral nano-zinc oxide microsphere, 2 is the first SiO2 shell, 3 is the second TiO2 shell, 4 is the second SiO2 shell, 5 is the second TiO2 shell, and 6 is a mixed layer of other cosmetic components. The equivalent DBR structure of the UV path is a triple structure, with some reflected by the DBR structure and some absorbed by the ZnO core. This structure filters UV rays from 280 to 370 nm (see [1]). Figure 6 spherical lines).

[0106] Example 3 was prepared according to the method of Example 1, with the variable being changed to 4 groups of SiO2 / TiO2 composite layers.

[0107] Comparative Example 1: Preparation of cosmetics containing ordinary nano zinc oxide sunscreen agent, the specific steps are as follows:

[0108] First, 5 parts of glyceryl stearate, 10 parts of glycerol, and 20 parts of anhydrous ethanol were mechanically stirred and mixed, then 15 parts of dicaprylyl carbonate, 8 parts of bis-ethylhexyloxyphenol methoxyphenyl triazine, and 8 parts of ethylhexyl methoxycinnamate were added, and finally 40 parts of nano zinc oxide particles with a particle size of 50-70 nm, 1 part of aloe vera soothing agent, and 0.5 parts of compound plant anti-allergic agent were added, and a planetary vacuum mixer was used to complete the homogenization of the inorganic nanoparticles.

[0109] Comparative Example 2: Preparation of cosmetics containing ordinary nano zinc oxide sunscreen agent, the specific steps are as follows:

[0110] First, 5 parts of glyceryl stearate, 10 parts of glycerol, and 20 parts of anhydrous ethanol were mechanically stirred and mixed, then 15 parts of dicaprylyl carbonate, 8 parts of bis-ethylhexyloxyphenol methoxyphenyl triazine, and 8 parts of ethylhexyl methoxycinnamate were added, and finally 40 parts of nano zinc oxide particles with a particle size of 300-350 nm, 1 part of aloe vera soothing agent, and 0.5 parts of compound plant anti-allergic agent were added, and a planetary vacuum mixer was used to complete the homogenization of the inorganic nanoparticles.

[0111] Comparative Example 3: Preparation of cosmetics containing ordinary nano zinc oxide sunscreen agent, the specific steps are as follows:

[0112] First, 5 parts of glyceryl stearate, 10 parts of glycerol, and 20 parts of anhydrous ethanol were mechanically stirred and mixed, and then 15 parts of dicaprylyl carbonate, 8 parts of bis-ethylhexyloxyphenol methoxyphenyl triazine, 8 parts of ethylhexyl methoxycinnamate, 1 part of aloe vera soothing agent, and 0.5 parts of compound plant anti-allergic agent were added, and a planetary vacuum mixer was used to complete the homogenization of the inorganic nanoparticles.

[0113] The sunscreen cosmetics prepared in Experimental Examples 1-3 and Comparative Example 1 were sampled and tested. The test standard is as follows: The sun protection factor (SPF) of the prepared emulsions was determined according to ISO 24443:2021. 30 mg of the prepared sunscreen emulsion was evenly applied to a PMMA plate. After drying in a dark environment for 15 minutes, the SPF value between 290 and 400 nm was measured at five different locations on the PMMA plate. Three plates were coated with each sample. The test results are shown in Table 1.

[0114] As can be seen from Table 1, when no physical sunscreen is added to Comparative Example 3, its SPF value is the lowest. However, Example 2, due to its significant UV reflection effect in the range of 280-370nm, can achieve an SPF50 effect even with a relatively low usage amount. Example 3, due to the increased number of DBR reflective layers, also brings a certain increase in UV reflectivity, thus improving the sun protection level. The minimum lengths of Examples 1-3 all exceed 200nm, while theoretical calculations show that the minimum length is less than 200nm when only two sets of DBR reflective layers are used in Example 1. Therefore, the core-shell structure material of the present invention can largely avoid the biotoxicity problem caused by nanopowder penetrating into the skin.

[0115] Table 1

[0116]

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sunscreen cosmetic composition, characterized in that The sunscreen cosmetic comprises the following components: 20 to 60 parts of a physical sunscreen, 0 to 30 parts of a chemical sunscreen, 0.01 to 1 part of an antioxidant, 5 to 20 parts of oil, 5 to 15 parts of a moisturizer, 1 to 5 parts of an emulsifier, 10 to 30 parts of anhydrous ethanol, and 0.1 to 3 parts of other additives. The physical sunscreen comprises polyhedral nano zinc oxide microspheres as cores, angular nano zinc oxide columns extending from the surface of the polyhedral nano zinc oxide microspheres, and then coated with a multilayer SiO2 / TiO2 periodic structure to form spherical ZnO@DBR composite nanoparticles.

2. A method for preparing the sunscreen cosmetic composition according to claim 1, characterized in that: The following steps are involved: S1: Synthesize nano-ZnO microspheres by hydrothermal method, and then anneal at high temperature under inert atmosphere to form polyhedral nano-ZnO microspheres with preferential crystal orientation; S1-1: Preparation of silver nanoparticles by hydrothermal method on the surface of polyhedral nano-ZnO microspheres to prepare lattice-mismatched growth surfaces; S1-2: hydrothermally growing angular nano-zinc oxide on the growth surface; S2: hydrothermal coating of SiO2 to form ZnO@SiO2 composite nanoparticles; S3: Hydrothermal coating of TiO2 to form ZnO@SiO2@TiO2 composite nanoparticles; S4: repeating steps S2 and S3 to form spherical ZnO@DBR composite nanoparticles with a stacking period greater than 2 of SiO2 / TiO2 composite layers; S5: 20-60 parts of ZnO@DBR composite nanoparticles as a physical sunscreen are mixed with 0-30 parts of a chemical sunscreen, 0.01-1 part of an antioxidant, 5-20 parts of oil, 5-15 parts of a moisturizer, 1-5 parts of an emulsifier, 10-30 parts of anhydrous ethanol, and 0.1-3 parts of other additives to prepare a sunscreen cosmetic composition.

3. The method for preparing the sunscreen cosmetic composition according to claim 2, wherein: The particle size of the nano zinc oxide microspheres prepared in step S1 is 50-70 nm, the thickness of the SiO2 shell prepared in step S2 is 20-40 nm, the thickness of the TiO2 shell prepared in step S3 is 10-30 nm, and the number of SiO2 / TiO2 composite layers in step S4 is 2-4 groups.

4. The method for preparing the sunscreen cosmetic composition according to claim 2, wherein: The optical refractive index of the SiO2, chemical sunscreen, antioxidant, oil, moisturizer, emulsifier and other additives is less than 1.55, the optical refractive index of the TiO2 is greater than or equal to 2.50, and the optical refractive index of the zinc oxide is 1.9-2.

1.

5. The method for preparing the sunscreen cosmetic composition according to claim 2, wherein: The particle size of the nano silver quantum dots is 5 to 10 nm, the length of the angular nano zinc oxide is 150 to 180 nm, and the root width is smaller than the polyhedron particle size.

6. The method for preparing the sunscreen cosmetic composition according to claim 2, wherein: The zinc source used in step S1 is one or more of zinc nitrate, zinc acetate and zinc chloride, the silicon source used in step S2 is one or more of tetraethyl orthosilicate, rice husk ash and water glass, and the titanium source used in step S3 is one or more of tetrabutyl titanate, titanium tetrachloride and titanium sulfate.

7. The method for preparing the sunscreen cosmetic composition according to claim 2, wherein: The chemical sunscreen in step S5 includes UVA and UVB sunscreens, wherein the UVA sunscreen is composed of one or more of bis-ethylhexyloxyphenol methoxyphenyl triazine, butyl methoxydibenzoylmethane, diethylaminohydroxybenzoyl hexyl benzoate, and butyl methoxybenzophenone, and the UVB sunscreen is composed of one or more of phenylbenzimidazole sulfonic acid, ethylhexyl salicylate, octyl salicylate, ethylhexyl methoxycinnamate, octyl dimethyl para-aminobenzoate, homosalate, polysiloxane, and octyl triazone.

8. The method for preparing the sunscreen cosmetic composition according to claim 2, wherein: The antioxidant in step S5 is composed of one or more of propylparaben, methylparaben, phenoxyethanol, benzyl alcohol, bis(hydroxymethyl)imidazolidinyl urea, and iodopropynyl butylcarbamate, the oil is composed of one or more of dicaprylyl carbonate, dipropylene glycol dibenzoate, octyl polymethylsiloxane, cyclopentasiloxane, and tridecyl stearate, the moisturizer is composed of one or more of glycerol, propylene glycol, butylene glycol, betaine, panthenol, and sodium hyaluronate, the emulsifier is composed of one or more of glyceryl stearate, polyglyceryl-3 diisostearate, cetearyl glucoside, and sorbitan olivate, and the other additives are composed of one or more of a soothing agent, an anti-allergic agent, a chelating agent, a cross-linking agent, and a fragrance.

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