Preparation method of temperature-sensitive cooling whitening sunscreen microspheres

Abstract

This invention discloses a method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres, relating to the field of cosmetic technology. The sun-protective microspheres are made from the following raw materials in parts by weight: stearic acid 1-3 parts, cetyl alcohol 1-3 parts, lauric acid 1-3 parts, stearyl alcohol polyether 2 1-2 parts, stearyl alcohol polyether 21 1-2 parts, cyclopentamethoxysiloxane 1-2 parts, cetearyl alcohol 2-4 parts, polydimethylsiloxane 1-2 parts, vitamin E 0.4-0.6 parts, deionized water 75-95 parts, niacinamide 1-3 parts, liquid paraffin 3-6 parts, Span 80 0.2-0.8 parts, titanium dioxide 4-7 parts, and citric acid solution 0.1-0.2 parts. This invention provides a method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres. By utilizing temperature-sensitive microsphere encapsulation and temperature-stimulation response technology, it can effectively solve the problems of poor cooling effect, low utilization rate of active sunscreen ingredients, and heavy and sticky feel of traditional sunscreen products. Furthermore, it allows the sunscreen active ingredients to be precisely released and exert their effects when the human skin temperature rises. This not only improves sun protection efficiency but also has a skin cooling function and improves the skin feel.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, specifically to a method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres. Background Technology

[0002] With extreme heat becoming the norm globally, sun protection and cooling have become essential for everyone. Traditional sunscreen microspheres can only protect against 4.5% of ultraviolet radiation, offering little effective protection against the remaining 95% of visible and infrared light. Furthermore, organic sunscreens decompose and release heat after absorbing UV rays, while inorganic sunscreens transmit heat, leading to increasingly hot skin under sun exposure. Additionally, the protective effect of these products diminishes rapidly at high temperatures, and their thick, sticky texture makes it difficult to balance sun protection effectiveness with a pleasant feel on the skin. Currently available temperature-controlled sunscreen materials often suffer from drawbacks such as mismatched temperature response with actual sun exposure scenarios, limited functionality, and poor formulation compatibility. There are currently no multifunctional sunscreens that simultaneously achieve intelligent targeted sun protection, active phase change heat absorption, and passive radiative cooling. Moreover, most sunscreen products cannot simultaneously address the multiple needs of sun protection, cooling, and whitening, failing to meet consumers' actual usage requirements.

[0003] Therefore, addressing the core pain point of sun protection and cooling is crucial. Achieving full-spectrum sun protection and intelligent temperature control from the root, while also considering whitening effects and a comfortable skin feel, is an urgent problem that this invention needs to solve. Summary of the Invention

[0004] To address the problems existing in the background technology, this invention provides a method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres. By utilizing temperature-sensitive microsphere encapsulation and temperature-stimulation response technology, it can effectively solve problems such as poor cooling effect, low utilization rate of active sunscreen ingredients, and heavy, sticky feel of traditional sunscreen products. Furthermore, it allows the sunscreen active ingredients to be precisely released and exert their effects when the human skin temperature rises. This not only improves the efficiency of sun protection and cooling but also has a skin cooling function, improving the user experience.

[0005] To achieve the above-mentioned technical objectives, the present invention mainly adopts the following technical solutions: This invention discloses a temperature-sensitive cooling, whitening, and sun-protective microsphere, comprising the following raw materials in parts by weight: 1-3 parts stearic acid, 1-3 parts cetyl alcohol, 1-3 parts lauric acid, 1-2 parts stearyl alcohol polyether 2, 1-2 parts stearyl alcohol polyether 21, 1-2 parts cyclopentamethoxysiloxane, 2-4 parts cetearyl alcohol, 1-2 parts polydimethylsiloxane, 1-2 parts vitamin E; 75-95 parts deionized water, 1-3 parts niacinamide; 3-6 parts liquid paraffin, 1-2 parts Span 80, 4-7 parts titanium dioxide, and 1-2 parts citric acid solution.

[0006] In a preferred embodiment of the present invention, the citric acid solution has a mass fraction of 10%.

[0007] This invention also discloses a method for preparing the aforementioned temperature-sensitive cooling, whitening, and sun-protective microspheres, comprising the following steps: Step 1: Prepare an internal oil phase containing titanium dioxide; Step 2: Prepare an aqueous solution of nicotinamide; Step 3: Prepare temperature-sensitive cooling, whitening, and sun-protective microspheres.

[0008] In a preferred embodiment of the present invention, step 1, the method for preparing the internal oil phase containing titanium dioxide, is as follows: Step 1.1, Preparation of internal oil phase: Stearic acid, cetyl alcohol, lauric acid, stearyl alcohol polyether 2, stearyl alcohol polyether 21, cyclopentamethoxysiloxane, cetearyl alcohol, polydimethylsiloxane, and vitamin E are mixed and heated to dissolve, thus obtaining internal oil phase O. Step 1.2: Preparation of titanium dioxide pre-dispersion slurry: Disperse titanium dioxide in liquid paraffin and Span 80, stir evenly to obtain titanium dioxide pre-dispersion slurry; Step 1.3: Preparation of internal oil phase containing titanium dioxide: Pour the pre-dispersed titanium dioxide slurry into the internal oil phase O, stir under heating conditions to obtain an internal oil phase containing titanium dioxide.

[0009] In a preferred embodiment of the present invention, in step 1.1, the heating condition is 75°C; in step 1.3, the heating condition is 75°C, the stirring time is 30 min, and the stirring speed is 2000 rpm.

[0010] In a preferred embodiment of the present invention, step 2, the method for preparing the nicotinamide aqueous solution is as follows: Nicotinamide was added to deionized water and dissolved under heating conditions to obtain an aqueous solution of nicotinamide.

[0011] In a preferred embodiment of the present invention, in step 2, the heating condition is 75°C.

[0012] In a preferred embodiment of the present invention, step 3, the method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres, is as follows: Step 3.1: Preparation of titanium dioxide-containing thermosensitive sunscreen microspheres O / W: Add nicotinamide aqueous solution to the titanium dioxide-containing internal oil phase, stir under heating conditions, emulsify, and obtain titanium dioxide-containing thermosensitive sunscreen microspheres O / W.

[0013] Step 3.2: Preparation of thermosensitive cooling whitening and sunscreen microspheres: The thermosensitive sunscreen microspheres containing titanium dioxide are cooled in an O / W gradient manner. When cooling begins, deionized water is added to bring the mass to 100 parts. Stirring is continued during the cooling process. When the temperature drops to 45°C, an appropriate amount of 10% citric acid solution is added to adjust the pH of the system to pH=5.5-6.0. The temperature is then further reduced to below 35°C, and stirring is stopped to obtain the thermosensitive cooling whitening and sunscreen microspheres.

[0014] In a preferred embodiment of the present invention, in step 3.1, the heating conditions are 75°C, the stirring time is 30 min, and the stirring speed is 2000 rpm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The method for preparing temperature-sensitive cooling whitening sunscreen microspheres provided by this invention can provide a stable environment for sunscreen active ingredients: the temperature-sensitive microsphere encapsulation technology used in the preparation process of the sunscreen microspheres can provide a stable encapsulation environment for unstable dispersed nano-titanium dioxide, so that it maintains a good dispersion state, is not easy to agglomerate, ensures stable sunscreen activity, and extends the effective period of sunscreen microspheres; enabling the active ingredients to be released precisely during use. The sunscreen microspheres are manufactured using temperature-stimulation-responsive technology. When the sunscreen microspheres come into contact with the temperature environment of human skin, the temperature-sensitive microspheres undergo a phase transition and precisely release nano-titanium dioxide, thus fully exerting the sunscreen effect. This not only reduces the amount of nano-titanium dioxide used, but also improves the utilization rate of the sunscreen active ingredient. The design concept of this invention can be used not only for the stable encapsulation and temperature-sensitive release of nano-titanium dioxide, but also for the design and application of other similar sunscreen ingredients that are prone to aggregation. Attached Figure Description

[0016] Figure 1 A flowchart illustrating the preparation method of temperature-sensitive cooling, whitening, and sun-protective microspheres provided in this embodiment of the invention; Figure 2 The DSC curve of the temperature-sensitive cooling whitening and sun protection microspheres of the present invention is shown below; Figure 3 This is an optical microscopic image of the titanium dioxide-containing microspheres of the temperature-sensitive cooling, whitening, and sun-protecting microspheres of the present invention before phase transition. Figure 4 This is an optical microscopic image of the phase transition of the titanium dioxide-containing microspheres of the temperature-sensitive cooling, whitening, and sun-protecting microspheres of the present invention. Figure 5 This is an optical micrograph of the titanium dioxide-free microspheres of the temperature-sensitive cooling, whitening, and sun-protecting microspheres of the present invention. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0018] A type of temperature-sensitive, cooling, whitening, and sun-protective microsphere is made from the following raw material ratio: 1 part stearic acid, 1 part cetyl alcohol, 3 parts lauric acid, 1.5 parts stearyl alcohol polyether 2, 1.5 parts stearyl alcohol polyether 21, 1.5 parts cyclopentamethoxysiloxane, 2 parts cetearyl alcohol, 0.5 parts polydimethylsiloxane, 0.5 parts vitamin E; 0.5 parts deionized water, 2 parts nicotinamide; 4 parts liquid paraffin, 0.5 parts Span 80, 5 parts titanium dioxide, 0.1-0.2 parts citric acid solution.

[0019] A method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres includes the following steps: (1) Stearic acid, cetyl alcohol, lauric acid, stearyl alcohol polyether 2, stearyl alcohol polyether 21, cyclopentamethoxysilane, cetearyl alcohol, polydimethylsiloxane (PDMS), and vitamin E are mixed and dissolved under heating at 75°C to obtain the internal oil phase O. (2) Disperse titanium dioxide in liquid paraffin and Span 80, stir evenly to obtain a pre-dispersed titanium dioxide slurry; (3) Pour the titanium dioxide pre-dispersed slurry into the internal oil phase O, and stir for 30 min at a temperature of 75℃ and a speed of 2000 rpm to obtain an internal oil phase containing titanium dioxide; (4) Add nicotinamide to 78 parts of deionized water and dissolve it at 75°C to obtain an aqueous solution of nicotinamide (aqueous phase W); (5) Add nicotinamide aqueous solution to the internal oil phase containing titanium dioxide, and stir and emulsify for 30 min at a temperature of 75℃ and a speed of 2000 rpm to obtain titanium dioxide thermosensitive sunscreen microspheres O / W; (6) Cool the titanium dioxide thermosensitive sunscreen microspheres in an O / W gradient. When cooling begins, add deionized water to a mass of 100 parts. Stir continuously during the cooling process. When the temperature drops to 45°C, add an appropriate amount of 10% citric acid solution to adjust the pH of the system to pH=5.5-6.0. Continue cooling to below 35°C and stop stirring to obtain thermosensitive cooling whitening sunscreen microspheres. Example

[0020] A type of temperature-sensitive, cooling, whitening, and sun-protective microsphere is made from the following raw material ratio: 1 part stearic acid, 3 parts cetyl alcohol, 3 parts lauric acid, 1.5 parts stearyl alcohol polyether 2, 1.5 parts stearyl alcohol polyether 21, 1.5 parts cyclopentamethoxysiloxane, 2 parts cetearyl alcohol, 0.5 parts polydimethylsiloxane, 0.5 parts vitamin E; 0.5 parts deionized water, 2 parts nicotinamide; 4 parts liquid paraffin, 0.5 parts Span 80, 5 parts titanium dioxide, 0.1-0.2 parts citric acid solution.

[0021] A method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres includes the following steps: (1) Stearic acid, cetyl alcohol, lauric acid, stearyl alcohol polyether 2, stearyl alcohol polyether 21, cyclopentamethoxysilane, cetearyl alcohol, polydimethylsiloxane (PDMS), and vitamin E are mixed and dissolved under heating at 75°C to obtain the internal oil phase O. (2) Disperse titanium dioxide in liquid paraffin and Span 80, stir evenly to obtain a pre-dispersed titanium dioxide slurry; (3) Pour the titanium dioxide pre-dispersed slurry into the internal oil phase O, and stir for 30 min at a temperature of 75℃ and a speed of 2000 rpm to obtain an internal oil phase containing titanium dioxide; (4) Add nicotinamide to 78 parts of deionized water and dissolve it at 75°C to obtain an aqueous solution of nicotinamide (aqueous phase W); (5) Add nicotinamide aqueous solution to the internal oil phase containing titanium dioxide, and stir and emulsify for 30 min at a temperature of 75℃ and a speed of 2000 rpm to obtain titanium dioxide thermosensitive sunscreen microspheres O / W; (6) Cool the titanium dioxide thermosensitive sunscreen microspheres in an O / W gradient. When cooling begins, add deionized water to a mass of 100 parts. Stir continuously during the cooling process. When the temperature drops to 45°C, add an appropriate amount of 10% citric acid solution to adjust the pH of the system to pH=5.5-6.0. Continue cooling to below 35°C and stop stirring to obtain thermosensitive cooling whitening sunscreen microspheres. Example

[0022] A type of temperature-sensitive, cooling, whitening, and sun-protective microsphere is made from the following raw material ratio: Stearic acid 3 parts, cetyl alcohol 1 part, lauric acid 3 parts, stearyl alcohol polyether 2 1.5 parts, stearyl alcohol polyether 21 1.5 parts, cyclopentamethoxysiloxane 1.5 parts, cetearyl alcohol 2 parts, polydimethylsiloxane 0.5 parts, vitamin E 0.5 parts; deionized water 80.5 parts, nicotinamide 2 parts; liquid paraffin 4 parts, Span 80 0.5 parts, titanium dioxide 5 parts, citric acid solution 0.1-0.2 parts.

[0023] A method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres includes the following steps: (1) Stearic acid, cetyl alcohol, lauric acid, stearyl alcohol polyether 2, stearyl alcohol polyether 21, cyclopentamethoxysilane, cetearyl alcohol, polydimethylsiloxane (PDMS), and vitamin E are mixed and dissolved under heating at 75°C to obtain the internal oil phase O. (2) Disperse titanium dioxide in liquid paraffin and Span 80, stir evenly to obtain a pre-dispersed titanium dioxide slurry; (3) Pour the titanium dioxide pre-dispersed slurry into the internal oil phase O, and stir for 30 min at a temperature of 75℃ and a speed of 2000 rpm to obtain an internal oil phase containing titanium dioxide; (4) Add nicotinamide to 78 parts of deionized water and dissolve it at 75°C to obtain an aqueous solution of nicotinamide (aqueous phase W); (5) Add nicotinamide aqueous solution to the internal oil phase containing titanium dioxide, and stir and emulsify for 30 min at a temperature of 75℃ and a speed of 2000 rpm to obtain titanium dioxide thermosensitive sunscreen microspheres O / W; (6) Cool the titanium dioxide thermosensitive sunscreen microspheres in an O / W gradient. When cooling begins, add deionized water to a mass of 100 parts. Stir continuously during the cooling process. When the temperature drops to 45°C, add an appropriate amount of 10% citric acid solution to adjust the pH of the system to pH=5.5-6.0. Continue cooling to below 35°C and stop stirring to obtain thermosensitive cooling whitening sunscreen microspheres.

Claims

1. A method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres, characterized in that, The raw materials include the following parts by weight: stearic acid 1-3 parts, cetyl alcohol 1-3 parts, lauric acid 1-3 parts, stearyl alcohol polyether 2 1-2 parts, stearyl alcohol polyether 21 1-2 parts, cyclopentamethoxysiloxane 1-2 parts, cetearyl alcohol 2-4 parts, polydimethylsiloxane 1-2 parts, vitamin E 0.4-0.6 parts, deionized water 75-95 parts, nicotinamide 1-3 parts, liquid paraffin 3-6 parts, Span 80 0.2-0.8 parts, titanium dioxide 4-7 parts, and citric acid solution 0.1-0.2 parts.

2. The temperature-sensitive cooling, whitening, and sun-protective microspheres according to claim 1, characterized in that, The titanium dioxide particles have a diameter of 30-200 nm, and the citric acid solution has a mass fraction of 10%.

3. The method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres according to claim 1, characterized in that, Includes the following steps: Step 1: Prepare an internal oil phase containing titanium dioxide; Step 2: Prepare an aqueous solution of nicotinamide; Step 3: Prepare temperature-sensitive cooling, whitening, and sun-protective microspheres.

4. The preparation method according to claim 3, characterized in that, In step 1, the method for preparing the internal oil phase containing titanium dioxide is as follows: Step 1.1, Preparation of internal oil phase: Stearic acid, cetyl alcohol, lauric acid, stearyl alcohol polyether 2, stearyl alcohol polyether 21, cyclopentamethoxysiloxane, cetearyl alcohol, polydimethylsiloxane, and vitamin E are mixed and heated to dissolve, thus obtaining the internal oil phase; Step 1.2: Preparation of titanium dioxide pre-dispersion slurry: Disperse titanium dioxide in liquid paraffin and Span 80, stir, and obtain titanium dioxide pre-dispersion slurry; Step 1.3: Preparation of internal oil phase containing titanium dioxide: Pour the pre-dispersed titanium dioxide slurry into the internal oil phase O, stir under heating conditions to obtain an internal oil phase containing titanium dioxide.

5. The preparation method according to claim 4, characterized in that, In step 1.1, the heating conditions are 60℃-90℃; in step 1.3, the heating conditions are 60℃-90℃, the stirring time is 10 min-30 min, and the stirring speed is 1500 rpm-3000 rpm.

6. The preparation method according to claim 3, characterized in that, In step 2, the method for preparing the nicotinamide aqueous solution is as follows: Nicotinamide was added to deionized water and dissolved under heating conditions to obtain an aqueous solution of nicotinamide.

7. The preparation method according to claim 6, characterized in that, The heating conditions are 60℃-90℃.

8. The preparation method according to claim 3, characterized in that, In step 3, the method for preparing temperature-sensitive cooling, whitening, and sun-protective microspheres is as follows: Step 3.1: Preparation of titanium dioxide-containing thermosensitive sunscreen microspheres O / W: Add nicotinamide aqueous solution to the titanium dioxide-containing internal oil phase, stir under heating conditions, emulsify, and obtain titanium dioxide-containing thermosensitive sunscreen microspheres O / W. Step 3.2: Preparation of thermosensitive cooling whitening and sunscreen microspheres: The thermosensitive sunscreen microspheres containing titanium dioxide are cooled in an O / W gradient. At the beginning of the cooling process, deionized water is added to bring the mass to 100 parts. Stirring is continued during the cooling process. When the temperature drops to 45°C, an appropriate amount of citric acid solution is added to adjust the pH of the system to pH=5.5-6.

0. The temperature is then further reduced to below 35°C, and stirring is stopped to obtain the thermosensitive cooling whitening and sunscreen microspheres.

9. The preparation method according to claim 8, characterized in that, In step 3.1, the heating conditions are 60℃-90℃, the stirring time is 10 min-30 min, and the stirring speed is 1500 rpm-2000 rpm.

10. Temperature-sensitive cooling, whitening, and sun-protective microspheres prepared by the preparation method according to any one of claims 1-9.

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