Water-dispersible microspheres cosmetic product and method for preparing the same

Abstract

The application discloses a water-dispersed microspheric cosmetic product, which comprises microspheres dispersed in an aqueous phase, wherein the average particle size of the microspheres is 0.4-2 mm; the microspheres comprise a powder composition, a grease composition and a binding agent, and the mass ratio of the powder composition, the grease composition and the binding agent is (70-80):(19-29):1; the grease composition has a kinematic viscosity of 5-20 cSt at 37.8 DEG C and a surface tension of 25-32 mN / m at 25 DEG C; and the binding agent is selected from metal soap binding agents. The aqueous phase comprises a water-soluble rheological modifier, which has a solubility in the grease of less than 0.1 wt%, and the aqueous phase has a yield stress of 5-15 Pa at 25 DEG C and an apparent viscosity of 0.05-0.5 Pa·s at a shear rate of 1000 s ‑1 The application realizes high-density stable loading of the microspheres on different cosmetic powder, solves the problem of single product cosmetic effect, and ensures the stability of the product.

Description

Technical Field

[0001] This application belongs to the field of cosmetic technology, specifically relating to a water-dispersible microsphere cosmetic product and its preparation method. Background Technology

[0002] Traditional makeup products consist of premixed components such as pigments, oils, water, and thickeners in a single system. However, the compatibility of powders with different oil and water phases varies, leading to sedimentation, stratification, and pigment agglomeration during long-term storage. Existing water-dispersible microparticle-based cosmetic products utilize small-diameter color-developing microcapsules, primarily focusing on a dewy, clear finish. These products are single-color and single-texture, failing to provide diverse effects such as soft-focus matte or shimmering pearlescent finishes. This results in severe product homogenization, making it difficult to cover different makeup scenarios and style requirements.

[0003] From a fundamental technical perspective, existing cosmetic products with water-dispersible microparticle appearances are essentially systems for maintaining the balance of a single phase. That is, the pigment microcapsules contain a small amount and a single type of pigment, sacrificing multiple makeup effects in exchange for better maintenance of system stability. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a water-dispersible microsphere cosmetic product and its preparation method. The water-dispersible microsphere cosmetic product of this application achieves high-density and stable loading of powders with different makeup effects by the microspheres, overcoming the limitation of single makeup effect in such products while also ensuring product stability and user experience.

[0005] In a first aspect, embodiments of this application provide a water-dispersible microsphere cosmetic product, comprising microspheres dispersed in an aqueous phase, the microspheres having an average particle size of 0.4 mm to 2 mm. The microspheres comprise a powder composition, an oil composition, and a binder, wherein the mass ratio of the powder composition, oil composition, and binder is (70-80):(19-29):1. The powder composition in the microspheres comprises at least two of pigments, mica, and boron nitride, and the pigments, mica, and boron nitride are surface-treated for hydrophobicity. The oil composition in the microspheres has a kinematic viscosity of 5 cSt to 20 cSt at 37.8°C and a surface tension of 25 mN / m to 32 mN / m at 25°C. The binder in the microspheres is selected from at least one metal soap binder. The aqueous phase comprises at least one water-soluble rheology modifier, which satisfies the following conditions: a solubility of less than 0.1 wt% in the oil composition, and a yield stress of 5 Pa to 15 Pa in the aqueous phase at 25°C and a shear rate of 1000 s⁻¹. -1 The apparent viscosity is between 0.05 Pa·s and 0.5 Pa·s.

[0006] In some alternative embodiments, the microspheres in the water-dispersible microsphere cosmetic product have a mass percentage of 10% to 20%, and the aqueous phase has a mass percentage of 80% to 90%.

[0007] In some alternative embodiments, the oil composition includes one or more of hydrogenated polyisobutylene, squalane, hydrogenated polydecene, isohexadecane, isododecane, and polydimethylsiloxane.

[0008] In some alternative embodiments, the pigment, mica, and boron nitride are hydrophobically treated with triethoxyoctylsilane.

[0009] In some alternative embodiments, the metal soap binder includes one or more of magnesium stearate, aluminum distearate, magnesium myristate, zinc myristate, and calcium stearate.

[0010] In some alternative embodiments, the water-soluble rheology modifier includes one or more of carbomer, polyacrylate crosspolymer-6, and sodium polyacrylamide dimethyl taurate.

[0011] In some alternative embodiments, the aqueous phase may further include one or more of a solvent, humectant, preservative, pH adjuster, antioxidant, and active ingredient.

[0012] In some alternative embodiments, the water-dispersible microsphere cosmetic product is pumped out through a pump head of the cosmetic packaging material. The pump head has a rupture structure within its fluid channel, comprising several through holes with a diameter smaller than the microsphere particle size, so that the microspheres rupture when pumped out, releasing the powder composition and oil composition within the microspheres.

[0013] In some alternative implementations, the cosmetic product is at least one of blush, foundation, face cream, serum, or toner.

[0014] Secondly, embodiments of this application provide a method for preparing a water-dispersible microsphere cosmetic product according to the first aspect of this application, comprising: stirring and mixing the raw materials in the aqueous phase at a first rotation speed to obtain an aqueous phase; mixing the powder composition and the binder to obtain an intermediate powder; adding an oil composition to the intermediate powder; stirring at room temperature until uniformly dispersed to obtain a microsphere material; granulating and sieving to obtain microspheres; adding the microspheres to the aqueous phase and mixing to obtain a water-dispersible microsphere cosmetic product.

[0015] Compared with existing technologies, the present invention aims to compound at least two of the following powders—pigment, mica, and boron nitride—in a high-density form (the powder composition accounts for 70% to 80% of the microsphere mass) within microspheres with an average particle size of 0.4 mm to 2 mm. The pigment provides coloring effects, boron nitride provides a soft-focus matte finish, and mica provides a pearlescent finish. Different makeup effects can be derived by adjusting the proportions of the powders, thus overcoming the limitation of single-effect makeup products. However, due to the differences in shape, particle size, density, and surface energy of these powders, and their high density distribution within the microspheres, problems such as uneven powder dispersion during preparation, easy breakage of the microspheres, and instability of the microspheres in the aqueous phase during storage are prone to occur. This also poses challenges to the pumpability and user experience of the product. In response, the technical solution provided in this application solves the comprehensive technical challenges of water-dispersible microsphere cosmetic products in terms of granulation, suspension, storage, and pumping rupture by synergistically combining four aspects: powder hydrophobic treatment, limitation of oil viscosity and surface tension parameters, selection of binder, and water phase rheological design.

[0016] First, all powders in the microspheres undergo surface hydrophobic treatment. The specific viscosity (1 cSt to 20.5 cSt at 37.8℃) and surface tension (25 mN / m to 32 mN / m) characteristics of the oil composition enable it to effectively wet the hydrophobic powders and form moderate liquid bridging forces. The metal soap binder provides auxiliary binding. Together, they control the cohesive strength of the microspheres within a window that facilitates granulation, prevents breakage during storage, and avoids pump breakage. Furthermore, the water-soluble rheology modifier has a solubility of less than 0.1 wt% in the oil composition, ensuring extremely poor compatibility with the oil composition in the microspheres. Therefore, it will not penetrate into the interior of the microspheres and weaken the oil powder bonding layer, further ensuring that the microspheres maintain structural integrity even during long-term aqueous suspension, without disintegration or softening. Secondly, under the action of water-soluble rheology modifiers, the yield stress of the aqueous phase at 25℃ is 5Pa to 15Pa, which is higher than the critical yield stress required for microsphere suspension, providing sufficient static support force so that the microspheres can be stably suspended in the aqueous phase and do not settle or stratify during long-term storage; while the aqueous phase at a shear rate of 1000s -1 The apparent viscosity of 0.05 Pa·s to 0.5 Pa·s ensures the product's pumpability, spreadability on the skin, and skin feel; the microspheres can be smoothly pumped out and ruptured along with the aqueous phase through the pump head channel, releasing fresh pigments and oils, providing a novel user experience. Attached Figure Description

[0017] Figure 1 The image shown is a physical product image of the water-dispersible microsphere liquid blush from Embodiment 1 of this application.

[0018] Figure 2 The image shown is a comparison of facial color saturation before and after application of the water-dispersible microsphere liquid blush from Example 1 of this application. Detailed Implementation

[0019] To make the purpose, technical solution, and beneficial technical effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0020] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, although not explicitly stated, every point or individual value between the endpoints of the range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit and combined with any other point or individual value or with other lower or upper limits to form a range not explicitly stated.

[0021] In the description of this application, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, and "multiple" in "one or more" means two or more.

[0022] The foregoing description of this application is not intended to describe every disclosed implementation or method. Instead, the following description provides more specific examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments that can be used in various combinations. The examples listed are representative only and should not be construed as exhaustive.

[0023] The purpose of this invention is to compound at least two powders selected from pigments, mica, and boron nitride in a high-density form (the powder composition accounts for 70% to 80% of the microsphere mass) within microspheres with an average particle size of 0.4 mm to 2 mm. The pigments provide coloring effects, boron nitride provides a soft-focus matte finish, and mica provides a pearlescent finish. Different makeup effects can be derived by adjusting the proportions of the powders, thus overcoming the limitation of single-effect makeup products. However, due to the differences in shape, particle size, density, and surface energy of these powders, and their high density distribution within the microspheres, problems such as uneven powder dispersion or microsphere breakage during preparation and instability of the microspheres in the aqueous phase during storage are prone to occur. This also poses challenges to the pumpability and usability of the product. To address these issues, the technical solution provided in this application solves the comprehensive technical challenges of water-dispersible microsphere cosmetic products in granulation, suspension, storage, and pumping breakage through the synergistic application of four aspects: hydrophobic powder treatment, limitation of oil viscosity and surface tension parameters, selection of binders, and aqueous phase rheological design.

[0024] The following will describe the water-dispersible microsphere cosmetic product and its preparation method in conjunction with the embodiments of this application.

[0025] This application provides a water-dispersible microsphere cosmetic product, comprising microspheres dispersed in an aqueous phase, wherein the average particle size of the microspheres is 0.4 mm to 2 mm. As an example, the average particle size of the microspheres can be 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, or any range of the above values. It should be noted that since the three-dimensional shape of the microspheres is not intuitive, this application describes the shape of the microspheres as the projected shape in the optical microscope testing area. It should also be noted that the average particle size of the microspheres in this application refers to the average radial dimension of multiple microspheres, where the radial dimension refers to the longest diameter of the microsphere. The longest diameter of the microsphere is also relative to the projected shape of the microsphere in the area; it refers to the distance between the two farthest points on a microsphere in the projected shape. Specifically, when the projected shape of the microsphere is a regular circle, the "longest diameter" refers to the diameter of the circle; when the projected shape is an ellipse, the "longest diameter" refers to the length of the major axis of the ellipse.

[0026] The microspheres comprise a powder composition, an oil composition, and a binder, wherein the mass ratio of the powder composition, the oil composition, and the binder is (70~80):(19~29):1. As an example, the mass ratio of the powder composition, the oil composition, and the binder can be 70:29:1, 71:28:1, 72:27:1, 73:26:1, 74:25:1, 75:24:1, 76:23:1, 77:22:1, 78:21:1, 79:20:1, 80:19:1, or any range of the above values.

[0027] The powder composition in the microspheres includes at least two of pigments, mica, and boron nitride, all of which undergo surface hydrophobic treatment. Pigments can be designated and distinguished using CI numbers, such as CI 77891, CI 77491, CI 77492, CI 73360, etc. Additionally, lakes are also a type of pigment. Lakes are formed by fixing water-soluble dyes onto an insoluble inorganic carrier through precipitation or adsorption, making them insoluble pigments that can be stably dispersed in cosmetic formulations. For example, a typical aluminum lake consists of CI 73360 and aluminum hydroxide. Mica and synthetic fluorophlogopite are pearlescent substrates, providing a pearlescent finish; pearlescent mica often also contains tin oxide as an auxiliary coating for the pearlescent pigment. Boron nitride is a soft-focus matte powder, providing a soft-focus matte finish. Surface hydrophobic treatment of pigments, mica, boron nitride, and other powders is a very common practice in the cosmetic raw material industry.

[0028] The oil composition in the microspheres has a kinematic viscosity of 5 cSt to 20 cSt at 37.8°C and a surface tension of 25 mN / m to 32 mN / m at 25°C. As an example, the kinematic viscosity of the oil composition at 37.8°C can be 5 cSt, 8 cSt, 10 cSt, 12 cSt, 15 cSt, 18 cSt, 20 cSt, or any range of the above values. The surface tension at 25°C can be 25 mN / m, 26 mN / m, 27 mN / m, 28 mN / m, 29 mN / m, 30 mN / m, 31 mN / m, 32 mN / m, or any range of the above values.

[0029] The kinematic viscosity of the oil composition at 37.8°C and its surface tension at 25°C can be determined according to standard testing methods generally accepted in the art. For example, kinematic viscosity can be determined according to the ASTM D445 glass capillary method at 37.8 ± 0.1°C; and surface tension can be determined according to the ASTM D1331 ring method at 25 ± 0.5°C.

[0030] The binder in the microspheres is selected from at least one metal soap binder. All powders in the microspheres are surface-hydrophobic treated. The specific viscosity (5 cSt to 20 cSt at 37.8°C) and surface tension (25 mN / m to 32 mN / m) characteristics of the oil composition enable it to wet the hydrophobic powders well and form a moderate liquid bridging force. The metal soap binder provides an auxiliary binding effect. Together, they control the cohesive strength of the microspheres within a window that prevents breakage during storage and pumping.

[0031] The aqueous phase contains at least one water-soluble rheology modifier, which satisfies the following conditions: its solubility in the oil composition is less than 0.1 wt%, and it causes the yield stress of the aqueous phase to be 5 Pa to 15 Pa at 25 °C and at a shear rate of 1000 s⁻¹. -1 The apparent viscosity is between 0.05 Pa·s and 0.5 Pa·s. As an example, a solubility of a water-soluble rheology modifier in an oil composition of less than 0.1 wt% means that the water-soluble rheology modifier is insoluble or nearly insoluble in the oil composition. The yield stress of the aqueous phase at 25°C can be 5 Pa, 6 Pa, 7 Pa, 8 Pa, 9 Pa, 10 Pa, 11 Pa, 12 Pa, 13 Pa, 14 Pa, 15 Pa, or any combination of the above values. The yield stress of the aqueous phase at a shear rate of 1000 s⁻¹... -1 The apparent viscosity can be 0.05 Pa·s, 0.1 Pa·s, 0.15 Pa·s, 0.2 Pa·s, 0.25 Pa·s, 0.3 Pa·s, 0.35 Pa·s, 0.4 Pa·s, 0.45 Pa·s, 0.5 Pa·s, or any range of the above values.

[0032] The yield stress of the aqueous phase at 25°C and at a shear rate of 1000 s⁻¹ were measured. -1 The apparent viscosity can be determined according to standard testing methods commonly used in the field. For example, the yield stress of the aqueous phase at 25°C can be determined by oscillation amplitude scanning according to DIN 53010-1:2025-11; at a shear rate of 1000 s⁻¹... -1 The apparent viscosity can be determined according to the method of ISO 3219 / GB / T21059.

[0033] The water-soluble rheology modifier has a solubility of less than 0.1 wt% in the oil-based composition, ensuring extremely poor compatibility with the oil-based composition in the microspheres. Therefore, it will not penetrate into the microspheres and weaken the oil-based powder binding layer, further ensuring that the microspheres maintain structural integrity and do not disintegrate or soften during long-term suspension in the aqueous phase. Secondly, under the action of the water-soluble rheology modifier, the yield stress of the aqueous phase at 25°C is 5 Pa to 15 Pa, higher than the critical yield stress required for microsphere suspension, providing sufficient static support force so that the microspheres are stably suspended in the aqueous phase and do not settle or stratify during long-term storage; while the aqueous phase at a shear rate of 1000 s⁻¹... -1 The apparent viscosity of 0.05 Pa·s to 0.5 Pa·s ensures the product's pumpability, allowing it to spread easily on the skin after pumping, providing a refreshing and non-sticky feel. At the same time, the microspheres can be smoothly pumped out and ruptured along with the aqueous phase through the pump head channel, releasing fresh pigments and oils for a novel user experience.

[0034] In some embodiments, the oil composition includes one or more of hydrogenated polyisobutylene, squalane, hydrogenated polydecene, isohexadecane, isododecane, and polydimethylsiloxane.

[0035] In some embodiments, the pigment, mica, and boron nitride are hydrophobically treated with triethoxyoctylsilane.

[0036] In some embodiments, the metal soap binder includes one or more of magnesium stearate, aluminum distearate, magnesium myristate, zinc myristate, and calcium stearate.

[0037] In some embodiments, the water-soluble rheology modifier includes one or more of carbomer, polyacrylate crosspolymer-6, and sodium polyacrylamide dimethyl taurate.

[0038] In some embodiments, the aqueous phase further comprises one or more of a solvent, humectant, preservative, pH adjuster, antioxidant, and active ingredient. The selection and content of humectants, preservatives, pH adjusters, antioxidants, and active ingredients in the aqueous phase are not specifically limited in this application, as long as the yield stress of the aqueous phase at 25°C is in the range of 5 Pa to 15 Pa and the shear rate is 1000 s⁻¹. 1The apparent viscosity is in the range of 0.05 Pa·s to 0.5 Pa·s. Conventional components in the aqueous phase other than water-soluble rheology modifiers, such as moisturizers, preservatives, pH adjusters, antioxidants, and active ingredients, can be freely selected according to the skin care or cosmetic effects that the product is expected to achieve.

[0039] In some embodiments, the moisturizer includes one or more of glycerin, butylene glycol, 1,2-pentanediol, and 1,2-hexanediol.

[0040] In some embodiments, the preservative includes one or more of ethylhexylglycerin, phenoxyethanol, and p-hydroxyacetophenone.

[0041] In some embodiments, the pH adjuster includes tromethamine.

[0042] In some embodiments, the antioxidant includes tocopherol.

[0043] In some embodiments, the active ingredient is selected from polydeoxyribonucleotide (PDRN), Candida beeswax / glucose / rapeseed oleate fermentation product, peony ( PAEONIA SUFFRUTICOSA One or more of the seed oils.

[0044] In some embodiments, the water-dispersible microsphere cosmetic product is pumped out through a pump head of the cosmetic packaging material. The pump head has a rupture structure within its fluid channel, the rupture structure including several through holes with a diameter smaller than the particle size of the microspheres, so that the microspheres rupture when pumped out through the pump head, releasing the powder composition and oil composition within the microspheres.

[0045] In some embodiments, the cosmetic product is at least one of blush, foundation, face cream, serum, or toner.

[0046] Secondly, embodiments of this application provide a method for preparing the water-dispersible microsphere cosmetic product of the first aspect of this application, including: S100, the aqueous phase raw material is stirred and mixed at the first rotation speed to obtain the aqueous phase; S200: Mix the powder composition and binder to obtain intermediate powder, add oil composition to intermediate powder, stir at room temperature until uniformly dispersed to obtain microspheres, and then granulate and sieve to obtain microspheres; S300: Add microspheres to the aqueous phase and mix to obtain a water-dispersible microsphere cosmetic product.

[0047] In some embodiments, the first rotational speed in step S100 is between 1000 rpm and 3000 rpm. As an example, the first rotational speed can be 1000 rpm, 1200 rpm, 1500 rpm, 1800 rpm, 2000 rpm, 2200 rpm, 2500 rpm, 2800 rpm, 3000 rpm, or any range of the above values.

[0048] In some embodiments, the mesh size of the sieve used in the sieving step is between 10 and 40 mesh. As an example, the mesh size of the sieve can be 10, 20, 30, 40, or any range of the above values.

[0049] Example The following embodiments describe the disclosure of this invention in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized using conventional methods and can be used directly without further processing. The instruments used in the embodiments are also commercially available. Furthermore, all raw materials in the comparative examples of this application can be purchased from conventional commercial channels according to their names, and the viscosity and surface tension parameters of the oil raw materials can be obtained from suppliers or obtained through self-testing.

[0050] Example 1 A water-dispersible microsphere liquid blush is prepared by the following steps: Mix the aqueous raw materials and put them into an emulsifying tank (HOMOGENIZING MIXER / MARK Model 2.5). Stir the mixture at room temperature at a speed of 1000~3000 rpm until it is completely dissolved and homogeneous to obtain the aqueous phase. The proportions of the aqueous phase raw materials, based on a total mass of 100 parts, are as follows: water (82.3 parts, Zhenchen Cosmetics), butylene glycol (5.5 parts, Daicel Co., Ltd.), glycerin (4.5 parts, Wilmar Biotechnology), methyl gluceth-20 (2.7 parts, Lubrizol), 1,2-pentanediol (2.6 parts, ACTIVON), 1,2-hexanediol (0.8 parts, Hanning Chemical), p-hydroxyacetophenone (0.4 parts, Hanning Chemical), tromethamine (0.2 parts, Yalu Chemical), carbomer (0.4 parts, Lubrizol / CARBOPOL® 981), and polyacrylate crosspolymer-6 (0.6 parts, SEPPIC SA / SEPIMAX ZEN).

[0051] The color powder, boron nitride, and binder in the powder composition raw materials are mixed evenly at 2000 rpm (RT-02B 2-piece pulverizer, 220V). Mica and synthetic fluorophlogopite in the powder composition raw materials are added and mixed evenly at 450 rpm (RT-02B 2-piece pulverizer, 75V) to obtain intermediate powder. The oil composition is added to the intermediate powder and stirred at room temperature (RT-02B 2-piece pulverizer, 75V) until evenly dispersed. After mixing and molding using a granulator (Xingyang Xinxing Machinery Factory ZLP-300), microspheres are obtained by sieving. The microsphere raw material composition, based on 100 parts by weight, is as follows: Powder composition: mica (20 parts), CI 77891 (20 parts), synthetic fluorophlogopite (18 parts), CI 77491 (7 parts), boron nitride (3 parts), aluminum hydroxide (3 parts), tin oxide (3 parts), CI 77492 (2 parts), CI 73360 (2 parts); all raw materials in the powder composition have undergone hydrophobic surface treatment with triethoxyoctylsilane, and are conventional surface-hydrophobic cosmetic powder raw materials in this field, purchased from Shanghai Zhizhen Zhichen Technology Co., Ltd. Binder: magnesium stearate (2 parts, Anhui Shafeng New Materials); Oil composition: hydrogenated polyisobutylene (20 parts, NOF CORPORATION / POLYSYNLANE).

[0052] The prepared microspheres are gradually added to the emulsification pot where the aqueous phase is prepared. The mass percentage of the microspheres is 16% and the mass percentage of the aqueous phase is 84%. The mixture is stirred at 100 rpm (using a Fluke disperser G8ZC00198-YF484) for 5-10 minutes until it is homogeneous. Once the mixture is homogeneous, stirring is stopped to obtain the water-dispersed microsphere liquid blush.

[0053] The names and key parameters of the raw materials, powder composition, oil composition, binder, etc. of Example 1 are shown in Tables 1 and 2.

[0054] Examples 2 to 5 Examples 2 to 5 prepared water-dispersible microsphere liquid blushes using the same steps as in Example 1. The names of raw materials and key parameters that differ from those in Example 1 are shown in Tables 1 and 2.

[0055] Compared to Example 1, in Example 2, CI 77491 was omitted and CI 77492 was added in the same mass proportion in the microsphere raw material part; the oil was replaced with 15 parts hydrogenated polyisobutylene and 5 parts squalane; the binder was replaced with the same mass proportion of magnesium myristate; and the mass ratio of the powder composition, oil and binder, and the average particle size of the microspheres were adjusted. In the aqueous phase raw material part, 0.5 parts of polyacrylate crosslinking polymer-6 and 0.5 parts of sodium polyacrylamide dimethyl taurate (Shandong Wanbo) were used as the water-soluble rheology modifier. At the same time, the conventional components in the aqueous phase raw material were appropriately adjusted within the commonly used range to achieve the following: the yield stress of the aqueous phase at 25°C and the shear rate at 1000 s⁻¹ were adjusted accordingly. -1 The apparent viscosity changed.

[0056] Compared to Example 1, in Example 3, the synthetic fluorophlogopite and CI 77491 were omitted from the powder composition, while the same mass parts of mica and CI 77891 were added; the oil was 12 parts of hydrogenated polyisobutylene and 8 parts of isododecane; the binder was calcium stearate; and the mass ratio of the powder composition, oil, and binder, as well as the average particle size of the microspheres, were adjusted. In the aqueous phase raw material, 0.3 parts of polyacrylate crosslinking polymer-6 and 0.6 parts of sodium polyacrylamide dimethyl taurate (Shandong Wanbo) were used as the water-soluble rheology modifier. Meanwhile, the conventional components in the aqueous phase raw material were appropriately adjusted within the commonly used range to achieve the desired yield stress of the aqueous phase at 25°C and a shear rate of 1000 s⁻¹. -1 The apparent viscosity changed.

[0057] Compared to Example 1, in Example 4, boron nitride and CI 73360 were omitted from the powder composition, while mica and CI 73363 were added in equal parts by mass; the oil was 10 parts of hydrogenated polydecene and 10 parts of isohexadecane; and the mass ratio of the powder composition, oil, and binder, as well as the average particle size of the microspheres, were adjusted. In the aqueous phase raw material, 0.5 parts of carbomer and 0.5 parts of polyacrylate crosslinking polymer-6 were used as the water-soluble rheology modifier. Meanwhile, the conventional components in the aqueous phase raw material were appropriately adjusted within their commonly used ranges to achieve the desired yield stress of the aqueous phase at 25°C and a shear rate of 1000 s⁻¹. -1 The apparent viscosity changed.

[0058] Compared to Example 1, in Example 5, CI 77492 and CI 73360 were omitted from the powder composition, while CI 77364 was added in the same mass proportions; the oil was 15 parts of polydimethylsiloxane and 5 parts of squalane; the binder was calcium stearate; and the mass ratio of the powder composition, oil, and binder, as well as the average particle size of the microspheres, were adjusted. In the aqueous phase raw material, 0.6 parts of carbomer and 0.4 parts of polyacrylate crosslinker-6 were used as the water-soluble rheology modifier. The conventional components in the aqueous phase raw material were appropriately adjusted within their commonly used ranges to achieve the desired yield stress at 25°C and a shear rate of 1000 s⁻¹. -1 The apparent viscosity changed.

[0059] Comparative Examples 1 to 3 Comparative Examples 1 to 3 were prepared using the same steps as in Example 1 to produce water-dispersible microsphere liquid blushes. The only difference from Example 1 was the oil component used in the microspheres, which resulted in different overall kinematic viscosity and surface tension of the oil component. Specifically, the oil in Comparative Example 1 was diisostearyl malate (Guangdong Kexing), the oil in Comparative Example 2 was 1.2 cSt low-viscosity hydrogenated polyisobutylene (NOF CORPORATION), and the oil in Comparative Example 3 was 2.5 cSt low-viscosity hydrogenated polydecene (Wanhua Chemical).

[0060] Comparative Examples 4 to 5 Comparative Examples 4 and 5 prepared water-dispersible microsphere liquid blushes according to the same steps as in Example 1, the only difference being that no binder was used in the microspheres or the amount of binder was different.

[0061] Comparative Examples 6 to 7 Comparative Examples 6 and 7 prepared water-dispersible microsphere liquid blushes according to the same steps as in Example 1, the only difference being the amount of water-soluble rheology modifier in the aqueous phase, thereby increasing the yield stress of the aqueous phase at a shear rate of 1000 s⁻¹. -1 The apparent viscosities differ. In Comparative Example 6, there were 0.1 parts of carbomer and 0.9 parts of polyacrylate crosslinker-6; in Comparative Example 7, there were 0.8 parts of carbomer and 0.2 parts of polyacrylate crosslinker-6.

[0062] The composition and key parameters of the microspheres in Examples 1 to 5 and Comparative Examples 1 to 7 are shown in Table 1.

[0063] Table 1. Composition and key parameters of microspheres

[0064] Note: "Percentage of mass in product" in Table 1 refers to the percentage of mass of microspheres in water-dispersible microsphere cosmetic products.

[0065] The composition and key parameters of the aqueous phase in Examples 1 to 5 and Comparative Examples 1 to 7 are shown in Table 2.

[0066] Table 2 Composition and key parameters of the aqueous phase

[0067] Note: The "percentage of mass content in the product" in Table 2 refers to the percentage of mass content of the aqueous phase in the water-dispersed microsphere cosmetic product.

[0068] Stability and usability testing (1) Stability of the preparation process: During the preparation process of Examples 1-5 and Comparative Examples 1-7, it was observed whether the microspheres ruptured and whether they could be stably suspended in the aqueous phase. If the number of ruptured microspheres was less than 5% of the total number of microspheres, the microspheres were considered not to have ruptured. If the number of microspheres stably suspended in the aqueous phase was more than 90% of the total number of microspheres, the microspheres were considered to be stably suspended.

[0069] Calculate the microsphere granulation yield: Weigh the microspheres obtained after granulation whose particle size falls within the target range, and compare them with the total mass of the raw materials input (total mass of powder composition, oil composition, and binder), and calculate the percentage: Granulation yield (%) = [mass of microspheres reaching the target average particle size / (mass of powder composition + mass of oil composition + mass of binder)] × 100%. Wherein, a microsphere is considered to have reached the target average particle size if the deviation of its longest diameter from the target average particle size is less than or equal to 50%.

[0070] (2) Storage stability: The microsphere-dispersed liquid blushes prepared in Examples 1-5 and Comparative Examples 1-7 were stored at room temperature for 3 months and at 48°C for 1 month to observe their stability: whether the microspheres did not rupture and whether they could be stably suspended in the aqueous phase without settling. If the number of microspheres that did not rupture or settle was higher than 90% of the total number of microspheres, it was determined that "the microspheres did not rupture or settle".

[0071] (3) Usability evaluation: Microsphere pumping rupture: The microsphere aqueous dispersion liquid blush prepared in Examples 1 to 5 and Comparative Examples 1 to 7 was filled into packaging material with a pump head and pumping test was performed to observe whether the microspheres ruptured during pumping. If the number of pumped ruptured microspheres was higher than 90% of the total number of microspheres, it was determined that the microspheres could be pumped ruptured.

[0072] Skin feel evaluation: 25 volunteers were divided into 5 groups and used the microsphere aqueous dispersion liquid blushes prepared in Examples 1 to 5 respectively to evaluate whether the skin feel was sticky or refreshing. If the number of volunteers who rated it as refreshing exceeded the number who rated it as sticky, it was recorded as refreshing; otherwise, it was recorded as sticky. Comparative Examples 1 to 7 did not have good stability during preparation or storage, therefore, no volunteer skin feel evaluation was conducted.

[0073] 8-Hour Makeup Duration Test: From the 5 groups of volunteers who participated in the skin feel evaluation, one volunteer was randomly selected from each group to test the makeup durability before and after application. After the microsphere water-dispersible liquid blush was evenly applied to the face, the facial color saturation score was measured before makeup application, immediately after makeup application, 4 hours after makeup application, and 8 hours after makeup application using a VISIA 7 (Canfield, USA) & ipp skin analyzer. The 8-hour facial color saturation retention rate was calculated as follows: 8-hour facial color saturation retention rate = (facial color saturation 8 hours after makeup application / facial color saturation after makeup application) × 100%. If the 8-hour facial color saturation retention rate is >60%, it indicates an 8-hour long-lasting makeup effect.

[0074] Figure 2 The table shows a comparison of facial color saturation before and after application of the water-dispersible microsphere liquid blush prepared in Example 1 for volunteers. Table 3 shows the color saturation scores and saturation retention rates of the volunteers' faces before makeup application, after makeup application, 4 hours after makeup application, and 8 hours after makeup application. According to the data in Table 3, the facial color saturation still remained at 74.05% after 8 hours of makeup application, therefore, the product is considered to have an 8-hour long-lasting makeup effect.

[0075] Table 3 Changes in facial color saturation before and after makeup application

[0076] The stability and usability test results of the water-dispersible microsphere liquid blushes of Examples 1 to 5 and Comparative Examples 1 to 7 are shown in Table 4.

[0077] Table 4. Stability and usability test results

[0078] According to the test data shown in Table 4, the water-dispersible microsphere liquid blushes prepared in Examples 1 to 5 incorporate at least two powders selected from pigment, mica, and boron nitride in a high-density form within microspheres with an average particle size of 0.4 mm to 2 mm. The pigment provides coloring effects, boron nitride provides a soft-focus matte finish, and mica provides a pearlescent finish, overcoming the limitation of single-effect makeup in this type of product. Although these powders vary in shape, particle size, density, and surface energy, and are distributed at a high density within the microspheres, Examples 1 to 5, through the synergistic effect of powder hydrophobic treatment, limiting oil viscosity and surface tension parameters, selecting binders, and aqueous rheological design, solved comprehensive technical challenges related to microsphere suspension, preparation and storage stability, pump breakage, skin feel, and makeup lasting power.

[0079] The selection of oil components in Comparative Examples 1 to 3 for the microspheres did not conform to the range defined in this application: "the kinematic viscosity of the oil component consisting of one or more oils is 5 to 20 cSt at 37.8°C, and the surface tension is 25 mN / m to 32 mN / m at 25°C." The overall viscosity and surface tension of the oil component both affect the ease of granulation. Viscosity mainly affects the flow resistance and viscous ability of the paste during mixing, extrusion, and spheronization, while surface tension mainly determines whether the oil can wet the powder and form stable liquid bridges. The microsphere granulation yield of Comparative Examples 1 to 3 decreased significantly. Furthermore, the replacement of the oil component in Comparative Examples 1 to 3 also affected the stability and pump-burst resistance of the product; the microspheres could no longer maintain the characteristics of "stable storage and pump-burst resistance."

[0080] Comparative Example 4 omitted the binder in the microspheres, while Comparative Example 5 used an excessive amount of binder. When the binder was omitted, the microsphere granulation yield decreased significantly, and the stability deteriorated. When the binder amount exceeded the appropriate range defined in this application, the paste hardened during granulation, leading to extrusion difficulties and failing to effectively improve the granulation yield. Furthermore, the microspheres also experienced pump failure and breakage. Therefore, adding a metal soap-based binder to the microspheres and controlling its content within a reasonable low range is also an important factor in ensuring granulation yield and performance characteristics.

[0081] In Comparative Example 6, PEG-10 polydimethylsiloxane was used instead of the water-soluble rheology modifier composed of carbomer and polyacrylate crosslinked polymer-6 in Example 1. Since PEG-10 polydimethylsiloxane has a solubility greater than 1 wt% in hydrogenated polyisobutylene, its application to the aqueous phase of the microspheres resulted in PEG-10 polydimethylsiloxane migrating into the interior of the microspheres, weakening the reinforcing effect of hydrogenated polyisobutylene on the structural stability of the microspheres. Consequently, the breakage rate of the microspheres during preparation and storage was significantly higher than in Example 1, which used carbomer and polyacrylate crosslinked polymer-6.

[0082] Although Comparative Examples 7 and 8 still used the water-soluble rheology modifier carbomer and polyacrylate crosslinker-6 in the aqueous phase, their amounts were insufficient to achieve a yield stress of 5 Pa to 15 Pa in the aqueous phase at 25 °C and a shear rate of 1000 s⁻¹. -1 The apparent viscosity is between 0.05 Pa·s and 0.5 Pa·s. As a result, the aqueous phase cannot provide sufficient static support to ensure that the microspheres can pass smoothly through the pump head channel and be pumped out without settling or stratifying during long-term storage, while also ensuring that the microspheres can break up. This results in the loss of the product's novel appearance and user experience.

[0083] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A water-dispersible microsphere cosmetic product, characterized in that, It includes microspheres dispersed in an aqueous phase, the average particle size of which is 0.4 mm to 2 mm; The microspheres comprise a powder composition, an oil composition, and a binder, wherein the mass ratio of the powder composition, the oil composition, and the binder is (70~80):(19~29):1; the powder composition comprises at least two of pigments, mica, and boron nitride, wherein the pigments, mica, and boron nitride are surface-hydrophobic treated; the oil composition has a kinematic viscosity of 5 cSt to 20 cSt at 37.8°C and a surface tension of 25 mN / m to 32 mN / m at 25°C; the binder is selected from at least one metal soap binder. The aqueous phase comprises at least one water-soluble rheology modifier, which satisfies the following conditions: its solubility in the oil composition is less than 0.1 wt%, and the aqueous phase has a yield stress of 5 Pa to 15 Pa at 25°C and a shear rate of 1000 s⁻¹. -1 The apparent viscosity is between 0.05 Pa·s and 0.5 Pa·s.

2. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The microspheres in the water-dispersible microsphere cosmetic product have a mass percentage content of 10% to 20%, and the aqueous phase in the water-dispersible microsphere cosmetic product has a mass percentage content of 80% to 90%.

3. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The oil composition comprises one or more of hydrogenated polyisobutylene, squalane, hydrogenated polydecene, isohexadecane, isododecane, and polydimethylsiloxane.

4. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The pigment, mica, and boron nitride are hydrophobically treated with triethoxyoctylsilane.

5. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The metal soap binder includes one or more of magnesium stearate, aluminum distearate, magnesium myristate, zinc myristate, and calcium stearate.

6. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The water-soluble rheology modifier includes one or more of carbomer, polyacrylate crosspolymer-6, and sodium polyacrylamide dimethyl taurate.

7. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The aqueous phase also includes one or more of the following: solvent, humectant, preservative, pH adjuster, antioxidant, and active ingredient.

8. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The water-dispersible microsphere cosmetic product is pumped out through a pump head of the cosmetic packaging material. The fluid channel of the pump head is provided with a rupture structure, which includes several through holes. The diameter of the through holes is smaller than the particle size of the microspheres.

9. The water-dispersible microsphere cosmetic product according to claim 1, characterized in that, The cosmetic product is at least one of blush, foundation, face cream, serum, or toner.

10. A method for preparing a water-dispersible microsphere cosmetic product according to any one of claims 1 to 8, characterized in that, include: The aqueous phase raw materials are stirred and mixed at a first rotation speed to obtain an aqueous phase; The powder composition and the binder are mixed to obtain an intermediate powder. The oil composition is added to the intermediate powder and stirred at room temperature until it is evenly dispersed to obtain microspheres. The microspheres are then obtained by granulation and sieving. The microspheres are added to the aqueous phase and mixed to obtain the water-dispersible microsphere cosmetic product.

Images