White matte transparent sericite powder with sunscreen function and preparation method of white matte transparent sericite powder
By coating the sericite powder with low refractive index metal oxides, a white matte transparent sericite powder with sun protection function is prepared, which solves the safety and effect of traditional sunscreens in cosmetics, and achieves the consideration of non-nano-size and sun protection functions.
Patent Information
- Application Number
- CN202510167441.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-16
- Publication Date
- 2025-04-25
AI Technical Summary
Sunscreens in existing cosmetics, such as nano zinc oxide and nano titanium dioxide, have the risk of penetrating the skin, and their use is restricted by some countries and regions, making it difficult to achieve both non-nano size and sun protection functions in cosmetics.
By coating the low-refractive index metal oxides, such as nanoscale oxides such as zinc, aluminum, iron and silicon, a white matte transparent sericite powder with sun protection function is prepared.
This sericite powder not only has matte transparency and good skin adhesion effect, but also has sun protection function. It is suitable for functional fillers in cosmetics, solving the problems of safety and effectiveness of traditional sunscreens in cosmetics.
Abstract
Description
Technical Field
[0001] The invention relates to a functional transparent sericite powder and a preparation method thereof, that is, a white matte transparent sericite powder with sunscreen function and a preparation method thereof, belonging to the field of color powder fillers or pigments for cosmetics. Background Art
[0002] As people's living standards improve, their pursuit of beauty and physical health continues to increase. The use of non-toxic nude makeup effects has become a focus of attention. In order to meet consumers' high requirements for colorants in cosmetics, research in the cosmetics industry is expanding day by day.
[0003] Muscovite is a type of layered silicate mineral. Sericite is a subspecies of muscovite. It is produced in fine particles. It is used as a filler in cosmetics for its smooth skin feel and low heavy metal content. There is a type of cosmetics with sunscreen function, which can absorb or shield ultraviolet rays so that the skin will not burn or darken. Common sunscreens include organic sunscreens and inorganic sunscreens. Organic sunscreens absorb ultraviolet rays and turn into small molecular organic matter, which is harmful to the human body. Inorganic sunscreens are extremely stable and will not decompose. They are widely used. Common inorganic sunscreens include nano zinc oxide and nano titanium dioxide. However, these nano-scale substances can easily enter the body through the pores and damage the organs. Some countries and regions have banned the use of nano materials in cosmetics. Sericite itself has the function of shielding ultraviolet rays. How to combine the two, both non-nano size and sunscreen function, is a problem we need to solve.
[0004] Natural sericite is superior to other fillers in terms of whiteness, purity, transparency and stability, and contains fewer impurities and heavy metal elements, so it has greater advantages in cosmetic applications.
[0005] However, since natural sericite itself is white or grayish white (grayish tone) with not too high whiteness, and is a low-refractive-index transparent substrate, it is difficult to obtain good angle-dependent color or colorful optical effects by coating it with a commonly used metal oxide layer. Therefore, technical personnel in this field believe that sericite has low application value in the field of pearlescent pigments for cosmetics and therefore do not pay attention to it. Summary of the invention
[0006] The purpose of the present application is to provide a white matte transparent sericite powder which can be used in cosmetics and has a sunscreen function.
[0007] The inventor of the present application has found through a large number of experiments that a sericite powder with sunscreen function can be obtained by coating a layer of low-refractive-index metal oxides, such as nano-scale oxides such as zinc, aluminum, iron, and silicon, on ultra-fine transparent low-refractive-index sericite powder (produced by Sichuan Saihe New Materials Technology Co., Ltd.). The sericite powder has matte transparency and certain sunscreen function, and exhibits a good skin adhesion effect. It is a new cosmetic-grade functional filler. It has the smoothness, transparency, and matte effect of sericite powder itself, and has certain sunscreen function, and can be used in cosmetics, thus completing the present invention.
[0008] First, the present invention provides a white, matte and transparent sericite powder with sunscreen function, referred to as sunscreen sericite powder, which comprises: 1) a microparticle-shaped low-refractive-index transparent sericite substrate, 2) a matte metal oxide coating layer or a hydrated silicon oxide coating layer on the surface of the substrate 1; Wherein 2) the matte metal oxide coating layer is one or two selected from (2a) a zinc oxide coating layer, (2b) an aluminum oxide coating layer, (2c) a zirconium oxide coating layer, (2d) a zinc oxide / aluminum oxide mixture coating layer, (2e) a zinc oxide / zirconium oxide mixture coating layer, (2f) an aluminum oxide / zirconium oxide mixture coating layer, i.e., one layer or two layers; Preferably, the average particle size of the low refractive index transparent sericite substrate 1) is 1.5-18 microns, more preferably 2-17 microns, more preferably 2.3-16 microns, more preferably 2.5-15 microns, more preferably 2.7-14 microns, more preferably 3-13 microns, more preferably 3.2-12 microns, more preferably 3.5-11 microns, more preferably 3.7-10 microns, more preferably 4-8 microns, more preferably 4-7 microns.
[0009] Preferably, based on 100 parts by weight of the low-refractive-index transparent sericite substrate, the weight of the matte metal oxide coating layer 2) on the surface of the substrate 1) is 2-13 parts by weight, preferably 2.5-12 parts by weight, more preferably 3-11 parts by weight, more preferably 4-10.5 parts by weight, more preferably 4.5-10 parts by weight, more preferably 5-9.5 parts by weight, more preferably 5.5-9 parts by weight, and more preferably 6-8 parts by weight.
[0010] The sericite powder further comprises: 3) a hydrated silicon oxide coating layer on the surface of the matte metal oxide coating layer 2).
[0011] Preferably, the weight parts of the hydrated silicon oxide coating layer 2) on the surface of the substrate 1), or the weight parts of the hydrated silicon oxide coating layer 3) on the surface of the metal oxide coating layer 2), is 4-14 weight parts, preferably 4.5-13 weight parts, more preferably 5-12 weight parts, more preferably 5.5-11 weight parts, more preferably 6-10 weight parts, more preferably 7-9 weight parts, based on 100 weight parts of matte sericite substrate.
[0012] Preferably, the matte metal oxide coating layer 2) has a thickness of 2-15 nm, preferably 2.3-13 nm, preferably 2.5-10 nm, preferably 2.7-9 nm, preferably 3-8.5 nm, more preferably 4-8 nm; and / or The matte metal oxide coating 2) is: zinc oxide coating, aluminum oxide coating, zirconium oxide coating, zinc oxide / aluminum oxide mixture coating, zinc oxide / zirconium oxide mixture coating, or aluminum oxide / zirconium oxide mixture coating; or, the matte metal oxide coating 2) is: in order from inside to outside, zinc oxide coating + aluminum oxide coating, aluminum oxide coating + zinc oxide coating, zinc oxide coating + zirconium oxide coating, zirconium oxide coating + zinc oxide coating, aluminum oxide coating + zirconium oxide coating, or zirconium oxide coating + aluminum oxide coating.
[0013] Preferably, the sun protection index of the sunscreen sericite powder is 3-8.5, preferably 4-8, preferably 4.5-8, more preferably 5-8, more preferably 6-7.5.
[0014] Secondly, the present invention also provides a method for preparing the above-mentioned white, matte and transparent sericite powder with sunscreen function, which comprises the following steps: (1) 100 parts by weight of low-refractive index transparent sericite powder is mixed with water (preferably deionized water) to form a suspension with a solid-liquid ratio of 1:(5-15), preferably 1:(6-14), preferably 1:(7-13), preferably 1:(8-12), and the mixture is stirred uniformly. The resulting suspension is heated to a temperature of, for example, 60-90° C., preferably 65-85° C., preferably 70-80° C., and the pH value of the suspension is adjusted to 3.0-8.0, preferably 3.5-7.0, preferably 3.7-6.8, preferably 4-6.5, using hydrochloric acid or alkali solution (alkali such as 5-30wt% sodium hydroxide aqueous solution or 10-30wt% ammonia aqueous solution, acid such as 5-10wt% hydrochloric acid solution); (2) Adding 1 to 10 parts by weight, preferably 2 to 9 parts by weight, preferably 3 to 8 parts by weight of an aqueous solution of a water-soluble metal salt (such as a zinc salt, an aluminum salt or a zirconium salt) corresponding to a metal oxide (such as zinc oxide, aluminum oxide or zirconium oxide), or an aqueous solution of a water-soluble silicon-containing salt (such as sodium metasilicate Na2SiO3) corresponding to hydrated silicon oxide to the suspension obtained in step (1), wherein the molar concentration of the water-soluble metal salt or the water-soluble silicon-containing salt is 0.15 to 2.5 mol / L, preferably 0.2 to 2.0 mol / L, preferably 0.25 to 1.8 mol / L, preferably 0.3 to 1.5 mol / L, for example 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4 mol / L; using an alkali or acid (an alkali such as a 5-30wt% sodium hydroxide aqueous solution or a 10-30wt% ammonia aqueous solution, an acid such as hydrochloric acid, such as a 5-10wt% hydrochloric acid solution) to keep the pH value of the mixture constant (for example, within an acidic pH range, for example, maintaining the pH value at 2.2-7.0, preferably 2.3-6.8, preferably 2.5-6.5, for example, pH value 3, 4, 5, 6), after the addition is completed, stirring at a constant temperature (5-50 minutes, for example, 15-30 minutes) to obtain a suspension; (3) Optionally, repeating step (2) and the various conditions used therein (including molar concentration, pH value, etc.), further adding 1 to 10 parts by weight, preferably 2 to 9 parts by weight, preferably 3 to 8 parts by weight of an aqueous solution of a water-soluble metal salt different from the water-soluble metal salt in step (2) to the suspension obtained in step (2) to obtain a suspension; (4) Optionally, 1 to 10 parts by weight, preferably 2 to 9 parts by weight, preferably 3 to 8 parts by weight of a water-soluble silicon salt-containing aqueous solution corresponding to hydrated silicon oxide is further added to the suspension obtained in step (2) or step (3), wherein the molar concentration of the silicon salt-containing aqueous solution is 0.15 to 2.5 mol / L, preferably 0.2 to 2.0 mol / L, preferably 0.25 to 1.8 mol / L, preferably 0.3 to 1.5 mol / L, for example 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4 mol / L; using hydrochloric acid (e.g., a hydrochloric acid solution having a concentration of 5 to 10 wt%) to keep the pH value of the mixture constant (e.g., within an acidic pH range, e.g., maintaining the pH value within a range of 2.2 to 7.0, preferably 2.3 to 6.8, preferably 2.5 to 6.5, e.g., pH values of 3, 4, 5, 6); after the addition is completed, stirring at a constant temperature (5 to 50 minutes, e.g., 15 to 30 minutes) to obtain a suspension; and (5) The suspension formed in the above step 2, 3 or 4 is filtered, washed and dried to obtain a white, matte and transparent sericite powder with sunscreen function, referred to as sunscreen sericite powder.
[0015] Preferably, the molar concentration of the aqueous solution of the metal salt is 0.2-2 mol / L, preferably 0.2-0.8 mol / L, particularly preferably 0.2-0.5 mol / L.
[0016] Preferably, in the sunscreen sericite powder, the coverage of the metal oxide is 1.5~13wt%, preferably 2-13 wt%, preferably 2.5-12 wt%, more preferably 3-11 wt%, more preferably 4-10.5 wt%, more preferably 4.5-10 wt%, more preferably 5-9.5wt%, more preferably 5.5-9 wt%, more preferably 6-8 wt%, based on the weight of the substrate.
[0017] Preferably, the water-soluble metal salt is a zinc salt and is selected from one or more of ZnCl2, ZnSO4 and Zn(NO3)2, wherein the water-soluble metal salt is an aluminum salt and is selected from one or more of AlCl3, Al2(SO)4 and Al(NO3)3, or, wherein the water-soluble metal salt is a zirconium salt and is selected from one or both of ZrCl4 and ZrOCl2.
[0018] Preferably, the silicon-containing salt is selected from sodium metasilicate (Na2SiO3) or sodium metasilicate hydrate.
[0019] Again, the present invention provides white, matte and transparent sericite powder with sunscreen function prepared by the above-mentioned preparation method.
[0020] The present invention also relates to the use of the white, matte and transparent sericite powder with sunscreen function in preparing cosmetics.
[0021] Specifically, the present invention provides a method for preparing sericite powder with sunscreen function, comprising the following steps: (1) 100 parts by weight of low-refractive index transparent sericite powder is mixed with deionized water to form a suspension with a solid-liquid ratio of 1:(5-15), preferably 1:(8-12), and the mixture is stirred uniformly. The suspension is heated to 65-85° C., preferably 70-80° C., and the pH of the suspension is adjusted to 3.0.0-8.0, preferably 4.0-7.0, with an alkali or acid (an alkali such as a 5-30 wt% sodium hydroxide aqueous solution or a 10-30 wt% ammonia aqueous solution; an acid such as hydrochloric acid, such as a 5-10 wt% hydrochloric acid solution); (2) adding 1 to 10 parts by weight, preferably 3 to 8 parts by weight, of a solution or a mixture of zinc salt, aluminum salt, zirconium salt, silicate, etc. corresponding to zinc oxide, aluminum oxide, zirconium oxide, silicon oxide, etc., wherein the molar concentration of the salt solution is 0.2 to 2 mol / L, and using an alkali or acid (such as an aqueous sodium hydroxide solution with a concentration of 5 to 30 wt% or an ammonia solution with a concentration of 10 to 30 wt%, or an acid such as a hydrochloric acid solution with a concentration of 5 to 10 wt%) to keep the pH value constant. After the addition is completed, stirring at a constant temperature for 15 minutes; (3) The suspension formed in the above steps is filtered, washed and dried to obtain functional transparent sericite powder.
[0022] Sericite is a subspecies of muscovite, which is produced in fine particles and is therefore a non-metallic mineral matrix.
[0023] The low refractive index transparent substrate is matte sericite. Matte sericite (produced by Sichuan Saihe New Material Technology Co., Ltd.) is a low refractive index transparent substrate, and its refractive index is 1.52-1.64, more preferably 1.54-1.62, more preferably 1.56-1.60, for example 1.58.
[0024] The matte oxide is composed of zinc oxide, aluminum oxide, zirconium oxide and silicon oxide. The molar concentration of the salt solution is 0.2-2 mol / L, preferably 0.2:0.8 mol / L, and particularly preferably 0.2-0.5 mol / L.
[0025] The coverage of the oxide is 1% to 10%, preferably 3 to 7%.
[0026] The zinc salt is selected from one or more of ZnCl2, ZnSO4 and Zn(NO3)2.
[0027] The aluminum salt is selected from one or more of AlCl3, Al2(SO)4 and Al(NO3)3.
[0028] The zirconium salt is selected from one or both of ZrCl4 and ZrOCl2.
[0029] Wherein the silicate is selected from Na2SiO3.
[0030] The drying can be carried out at 80-150° C., preferably 100-120° C., for 10 to 60 minutes, preferably 20 to 30 minutes.
[0031] The present invention further relates to functional sericite powder prepared by the method.
[0032] Compared with the prior art, the beneficial technical effects of the present invention are: The sunscreen sericite powder (pigment) is a sericite powder composed of low refractive index oxides. The sericite powder has matte transparency and sunscreen function, and exhibits a good skin adhesion effect. It is a new cosmetic-grade functional filler, so it can be widely used in various cosmetics. The sunscreen sericite powder is obtained through the specific optical effect between the matrix and the coating layer. It has a suitable particle size, which is not too fine to block pores, and not too coarse to irritate the skin, and has a good skin feel. DETAILED DESCRIPTION
[0033] To better illustrate the present invention, the technical solutions in the embodiments of the present invention are fully described below. The following embodiments are used to further illustrate the present invention, but do not limit the present invention.
[0034] Sericite powder is used as the base material and coated with oxides of different components. Example 1
[0035] (1) Weigh 100 g of sericite powder (produced by Sichuan Saihe New Materials Technology Co., Ltd., with a refractive index of 1.59) with a particle size of less than 15 μm (average particle size of 9 μm) and put it into a 2 L reactor, add 1000 ml of deionized water, and stir to evenly disperse it into a suspension; (2) The suspension was heated in a constant temperature water bath and stabilized at 75°C, and the pH was adjusted to 6.5 with dilute hydrochloric acid (7.5 wt%); (3) According to the amount of zinc oxide added (or coated), 8.37 g ZnCl2 was dissolved in 150 ml water to prepare a mixed solution, and the mixed solution was added dropwise at a rate of 0.8 ml / min. At the same time, the pH was kept constant at 6.5 with sodium hydroxide solution. After the addition was completed, the mixture was stirred at a constant temperature for 15 minutes; (4) After the reaction is completed, the suspension is filtered, washed with deionized water, and dried at 105°C; (5) The structure of the pigment obtained is as follows: 100 parts of sericite powder is used as a base material, 5 parts of zinc oxide is coated on the surface of the mica base material, and the coating layer thickness is about 6 nm, thereby obtaining white matte transparent sericite powder. Example 2
[0036] (1) Weigh 100 g of sericite powder (average particle size 6 μm) with a particle size of less than 8 μm into a 2 L reactor, add 1000 ml of deionized water, and stir to evenly disperse it into a suspension; (2) The suspension was heated in a constant temperature water bath and stabilized at 80°C, and the pH was adjusted to 3.5 with dilute hydrochloric acid (7.5 wt%); (3) According to the amount of aluminum oxide added (or coated), 23.67 g of AlCl3·6H2O was dissolved in 200 ml of water to prepare a mixed solution, and the mixed solution was added dropwise at a rate of 0.6 ml / min. At the same time, the pH was kept constant at 3.5 with sodium hydroxide solution. After the addition was completed, the mixture was stirred at a constant temperature for 15 minutes; (4) After the reaction is completed, the suspension is filtered, washed with deionized water, and dried at 105°C; (5) The structure of the pigment obtained is as follows: 100 parts of sericite powder is used as a base material, 5 parts of aluminum oxide is coated on the surface of the mica base material, and the coating layer thickness is about 4 nm, thereby obtaining white matte transparent sericite powder. Example 3
[0037] (1) Weigh 100 g of sericite powder with a particle size of less than 15 μm, put it into a 2 L reactor, add 1000 ml of deionized water, and stir to evenly disperse it into a suspension; (2) The suspension was heated in a constant temperature water bath and stabilized at 80°C, and the pH was adjusted to 4.0 with dilute hydrochloric acid (7.5 wt%); (3) According to the amount of zirconium oxide added (or coated), 20.92g ZrOCl2 was dissolved in 150ml water to prepare a mixed solution, and the mixed solution was added dropwise at a rate of 0.6ml / min. At the same time, the pH was kept constant at 4.0 with sodium hydroxide solution. After the addition was completed, the mixture was stirred at a constant temperature for 15 minutes; (4) After the reaction is completed, the suspension is filtered, washed with deionized water, and dried at 105°C; (5) The structure of the pigment obtained is as follows: 100 parts of sericite powder is used as a base material, 8 parts of zirconium oxide is coated on the surface of the mica base material, and the coating layer thickness is about 7 nm, thereby obtaining white matte transparent sericite powder. Example 4
[0038] (1) Weigh 100 g of sericite powder with a particle size of 5 to 25 μm, put it into a 2 L reactor, add 1000 ml of deionized water, and stir to evenly disperse it into a suspension; (2) The suspension was heated in a constant temperature water bath and stabilized at 83°C, and the pH was adjusted to 6.5 with dilute hydrochloric acid (7.5 wt%); (3) According to the amount of hydrated silicon oxide added (or coated), 36.44 g Na2SiO3·9H2O was dissolved in 250 ml of water to prepare a mixed solution, and the mixed solution was added dropwise at a rate of 0.5 ml / min. At the same time, a dilute hydrochloric acid solution (7.5 wt%) was used to keep the pH constant at 6.5. After the addition was completed, the mixture was stirred at a constant temperature for 15 minutes; (4) After the reaction is completed, the suspension is filtered, washed with deionized water, and dried at 105°C; (5) The structure of the pigment obtained is as follows: 100 parts of sericite powder are used as a base material, and 10 parts of hydrated silicon oxide are coated on the surface of the mica base material. The coating layer has a thickness of about 8 nm, and white matte transparent sericite powder is obtained. Example 5
[0039] (1) Weigh 100 g of sericite powder (average particle size 6 μm) with a particle size of less than 8 μm into a 2 L reactor, add 1000 ml of deionized water, and stir to evenly disperse it into a suspension; (2) The suspension was heated in a constant temperature water bath and stabilized at 83°C, and the pH was adjusted to 6.5 with dilute hydrochloric acid (7.5 wt%); (3) According to the amount of hydrated silicon oxide added (or coated), 18.22 g of Na2SiO3·9H2O was dissolved in 150 ml of water to prepare a mixed solution, and the mixed solution was added dropwise at a rate of 0.3 ml / min. At the same time, a dilute hydrochloric acid solution (7.5 wt%) was used to keep the pH constant at 6.5. After the addition was completed, the mixture was stirred at a constant temperature for 15 minutes; (4) The suspension is stabilized at 80°C in a constant temperature water bath; (5) According to the amount of zinc oxide added (or coated), 8.37 g ZnCl2 was dissolved in 150 ml water to prepare a mixed solution, and the mixed solution was added dropwise at a rate of 0.8 ml / min. At the same time, the pH was kept constant at 6.5 with sodium hydroxide solution. After the addition was completed, the mixture was stirred at a constant temperature for 15 minutes; (6) After the reaction is completed, the suspension is filtered, washed with deionized water, and dried at 105°C; (7) The structure of the pigment obtained is as follows: 100 parts of sericite powder is used as the base material, and 5 parts of silicon oxide and 5 parts of zinc oxide are coated on the surface of the mica base material. The total thickness of the two coating layers is about 8 nm, and white matte transparent sericite powder is obtained. Example 6
[0040] (1) Weigh 100 g of sericite powder with an average particle size of 5 μm and put it into a 2 L reactor, add 1000 ml of deionized water, and stir to evenly disperse it into a suspension; (2) The suspension was heated in a constant temperature water bath and stabilized at 80°C, and the pH was adjusted to 4.5 with dilute hydrochloric acid (7.5 wt%); (3) Weigh 23.67 g AlCl3·6H2O and 10.46 g ZnCl2 and dissolve them in 250 ml water to prepare a mixed solution. Add the mixed solution dropwise at a rate of 0.8 ml / min, and use sodium hydroxide solution (5 wt%) to keep the pH constant at 4.5. After the addition is completed, stir at a constant temperature for 15 minutes. (4) After the reaction is completed, the suspension is filtered, washed with deionized water, and dried at 105°C; (5) The structure of the pigment obtained is as follows: 100 parts of sericite powder is used as a base material, 5 parts of aluminum oxide and 6.25 parts of zinc oxide are coated on the surface of the mica base material, and the coating layer thickness is about 7 nm, thereby obtaining white matte transparent sericite powder.
[0041] test: Take 20g of sericite raw material and samples of implementation 1, 2, 3, 4, 5, and 6 in a 250ml beaker, spray with 0.4g KH550 (silane coupling agent) 30% ethanol solution, stir repeatedly to mix, add 0.4g triethanolamine and 60g liquid paraffin, stir evenly. Use a card applicator to evenly scrape on the tape, and test with an SPF detector. The data is shown in Table 1.
[0042] Table 1 Indicators\Samples Sericite powder Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 SPF 2 7 4 4 3 7.5 8 Note: SPF stands for sun protection factor. The larger the SPF value, the better the sun protection effect.
[0043] SPF = time of minimal erythema dose when using sunscreen (min) / time of minimal erythema dose when unprotected skin (min).
[0044] It can be seen from the table that sericite itself has a certain sunscreen function, and the samples prepared by the technical method of the present invention all have good sunscreen effects, with zinc oxide coating having the best effect, followed by iron oxide, and other oxides taking second place.
[0045] The results show that when 2-10 parts of zinc-aluminum-zirconium-silicon oxide are coated and the coating thickness is about 2-8nm, white matte transparent sericite powder can be obtained on the surface of sericite. Therefore, the treated sericite powder can be used in cosmetics as a functional filler. It is a matte, transparent sunscreen functional sericite powder with good dispersibility.
[0046] In addition, the product of the present invention has a suitable particle size, which is not too fine to clog pores, and not too coarse to irritate the skin, and has a good skin feel.
[0047] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. White, matte and transparent sericite powder with sunscreen function, the sunscreen sericite powder includes: 1) A micronized low-refractive-index transparent sericite substrate, and 2) a matte metal oxide coating or a hydrated silicon oxide coating on the surface of substrate 1); Wherein 2) the matte metal oxide coating layer is one or two selected from (2a) a zinc oxide coating layer, (2b) an aluminum oxide coating layer, (2c) a zirconium oxide coating layer, (2d) a zinc oxide / aluminum oxide mixture coating layer, (2e) a zinc oxide / zirconium oxide mixture coating layer, (2f) an aluminum oxide / zirconium oxide mixture coating layer, i.e., one layer or two layers; Preferably, the average particle size of the low refractive index transparent sericite substrate 1) is 1.5-18 microns, more preferably 2-17 microns, more preferably 2.3-16 microns, more preferably 2.5-15 microns, more preferably 2.7-14 microns, more preferably 3-13 microns, more preferably 3.2-12 microns, more preferably 3.5-11 microns, more preferably 3.7-10 microns, more preferably 4-8 microns, more preferably 4-7 microns.
2. The sunscreen sericite powder according to claim 1, wherein: Based on 100 parts by weight of the low-refractive index transparent sericite substrate, the weight of the matte metal oxide coating layer 2) on the surface of the substrate 1) is 2-13 parts by weight, preferably 2.5-12 parts by weight, more preferably 3-11 parts by weight, more preferably 4-10.5 parts by weight, more preferably 4.5-10 parts by weight, more preferably 5-9.5 parts by weight, more preferably 5.5-9 parts by weight, more preferably 6-8 parts by weight; and / or The sericite powder further comprises: 3) a hydrated silicon oxide coating layer on the surface of the matte metal oxide coating layer 2).
3. The sunscreen sericite powder according to claim 2, wherein: The weight parts of the hydrated silicon oxide coating layer 2) on the surface of the substrate 1), or the weight parts of the hydrated silicon oxide coating layer 3) on the surface of the metal oxide coating layer 2), is 4-14 weight parts, preferably 4.5-13 weight parts, more preferably 5-12 weight parts, more preferably 5.5-11 weight parts, more preferably 6-10 weight parts, more preferably 7-9 weight parts, based on 100 weight parts of matte sericite substrate.
4. The sunscreen sericite powder according to any one of claims 1 to 3, wherein: The matte metal oxide coating layer 2) has a thickness of 2-15 nm, preferably 2.3-13 nm, preferably 2.5-10 nm, preferably 2.7-9 nm, preferably 3-8.5 nm, more preferably 4-8 nm; and / or The matte metal oxide coating 2) is: zinc oxide coating, aluminum oxide coating, zirconium oxide coating, zinc oxide / aluminum oxide mixture coating, zinc oxide / zirconium oxide mixture coating, or aluminum oxide / zirconium oxide mixture coating; or, the matte metal oxide coating 2) is: in order from inside to outside, zinc oxide coating + aluminum oxide coating, aluminum oxide coating + zinc oxide coating, zinc oxide coating + zirconium oxide coating, zirconium oxide coating + zinc oxide coating, aluminum oxide coating + zirconium oxide coating, or zirconium oxide coating + aluminum oxide coating.
5. The sunscreen sericite powder according to any one of claims 1 to 4, wherein: The sun protection index of the sunscreen sericite powder is 3-8.5, preferably 4-8, preferably 4.5-8, more preferably 5-8, more preferably 6-7.
5.
6. A method for preparing the white, matte and transparent sericite powder with sunscreen function according to any one of claims 1 to 5, the method comprising the following steps: (1) 100 parts by weight of low-refractive index transparent sericite powder is mixed with water to form a suspension with a solid-liquid ratio of 1:(5-15), preferably 1:(6-14), preferably 1:(7-13), preferably 1:(8-12), and the mixture is stirred uniformly. The resulting suspension is heated to a temperature of, for example, 60-90° C., preferably 65-85° C., preferably 70-80° C., and the pH value of the suspension is adjusted to 3.0-8.0, preferably 3.5-7.0, preferably 3.7-6.8, preferably 4-6.5, using hydrochloric acid or alkali solution; (2) Adding 1 to 10 parts by weight, preferably 2 to 9 parts by weight, preferably 3 to 8 parts by weight of an aqueous solution of a water-soluble metal salt (such as a zinc salt, an aluminum salt or a zirconium salt) corresponding to a metal oxide (such as zinc oxide, aluminum oxide or zirconium oxide), or an aqueous solution of a water-soluble silicon-containing salt (such as sodium metasilicate Na2SiO3) corresponding to hydrated silicon oxide to the suspension obtained in step (1), wherein the molar concentration of the water-soluble metal salt or the water-soluble silicon-containing salt is 0.15 to 2.5 mol / L, preferably 0.2 to 2.0 mol / L, preferably 0.25 to 1.8 mol / L, preferably 0.3 to 1.5 mol / L, for example, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4 mol / L; using an alkali or an acid (for example, an aqueous sodium hydroxide solution with a concentration of 5 to 30 wt% or an ammonia solution with a concentration of 10 to 30 wt%; an acid such as hydrochloric acid, such as a hydrochloric acid solution with a concentration of 5 to 10 wt%) to keep the pH value of the mixture constant (for example, keeping it in an acidic pH range, for example, keeping the pH value at 2.2 to 7.0, preferably 2.3 to 6.8, preferably 2.5 to 6.5, for example, pH 3, 4, 5, 6), after the addition is completed, stirring at a constant temperature (5 to 50 minutes, for example, 15 to 30 minutes) to obtain a suspension; (3) Optionally, repeating step (2) and the conditions used therein, further adding 1 to 10 parts by weight, preferably 2 to 9 parts by weight, preferably 3 to 8 parts by weight of an aqueous solution of a water-soluble metal salt different from the water-soluble metal salt in step (2) to the suspension obtained in step (2) to obtain a suspension; (4) Optionally, 1 to 10 parts by weight, preferably 2 to 9 parts by weight, preferably 3 to 8 parts by weight of a water-soluble silicon salt-containing aqueous solution corresponding to hydrated silicon oxide is further added to the suspension obtained in step (2) or step (3), wherein the molar concentration of the silicon salt-containing aqueous solution is 0.15 to 2.5 mol / L, preferably 0.2 to 2.0 mol / L, preferably 0.25 to 1.8 mol / L, preferably 0.3 to 1.5 mol / L, for example 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4 mol / L; using hydrochloric acid (e.g., a hydrochloric acid solution having a concentration of 5 to 10 wt%) to keep the pH value of the mixture constant (e.g., within an acidic pH range, e.g., maintaining the pH value within a range of 2.2 to 7.0, preferably 2.3 to 6.8, preferably 2.5 to 6.5, e.g., pH values of 3, 4, 5, 6); after the addition is completed, stirring at a constant temperature (5 to 50 minutes, e.g., 15 to 30 minutes) to obtain a suspension; and (5) The suspension formed in the above step 2, 3 or 4 is filtered, washed and dried to obtain a white, matte and transparent sericite powder with sunscreen function, i.e., sunscreen sericite powder.
7. The method for preparing sunscreen sericite powder according to claim 6, wherein the molar concentration of the aqueous solution of the metal salt is 0.2-2 mol / L, preferably 0.2-0.8 mol / L, and particularly preferably 0.2-0.5 mol / L.
8. The preparation method according to claim 6 or 7, wherein In the sunscreen sericite powder, the coverage of the metal oxide is 1.5-13 wt%, preferably 2-13 wt%, preferably 2.5-12 wt%, more preferably 3-11 wt%, more preferably 4-10.5 wt%, more preferably 4.5-10 wt%, more preferably 5-9.5 wt%, more preferably 5.5-9 wt%, more preferably 6-8 wt%, based on the weight of the substrate; and / or wherein the water-soluble metal salt is a zinc salt and is selected from one or more of ZnCl2, ZnSO4 and Zn(NO3)2, wherein the water-soluble metal salt is an aluminum salt and is selected from one or more of AlCl3, Al2(SO)4 and Al(NO3)3, or wherein the water-soluble metal salt is a zirconium salt and is selected from one or both of ZrCl4 and ZrOCl2; and / or The silicon-containing salt is selected from sodium metasilicate (Na2SiO3) or sodium metasilicate hydrate.
9. White, matte and transparent sericite powder with sunscreen function prepared by the preparation method according to any one of claims 6 to 8.
10. Use of the white, matte and transparent sericite powder with sunscreen function according to any one of claims 1 to 5 or the white, matte and transparent sericite powder with sunscreen function according to claim 9 in preparing cosmetics.