A thermal sensitive temperature change mask base cloth and a preparation method thereof

Abstract

The application relates to the field of daily cosmetics, in particular to a heat-sensing temperature change mask base cloth and a preparation method thereof, which comprises the following steps: S1, uniformly mixing a sodium alginate aqueous solution and microencapsulated temperature change dyes, stirring until the system is uniformly dispersed to obtain a mixed spinning solution; S2, after vacuum defoaming treatment of the mixed spinning solution, performing wet spinning forming to obtain nascent fibers; and S3, after the nascent fibers are sequentially subjected to drafting and stretching, fixed-length cutting and drying and setting, the heat-sensing temperature change mask base cloth is obtained. The temperature change dyes are microencapsulated, hidden dangers of contact between the dyes and the skin can be avoided, the service life of the temperature change function is prolonged, and by mixing the microencapsulated temperature change dyes and the sodium alginate solution and then in-situ embedding the microencapsulated temperature change dyes into the fiber interior through wet spinning, it is ensured that the mask base cloth can overall change color and the color fastness is ideal.

Description

Technical Field

[0001] This application relates to the field of daily cosmetics, and in particular to a heat-sensitive thermochromic mask base fabric and its preparation method. Background Technology

[0002] In recent years, with the rapid development of smart textile materials and functional skincare product substrates, fiber mask base fabrics with thermochromic properties have gradually become a research hotspot. These products typically introduce thermochromic materials (such as ternary complexes composed of fluorescein leuco dyes, developers, and solvents) into fibers or nonwoven fabrics, which then exhibit reversible color responses by sensing changes in skin temperature, thereby giving the mask new functions such as fun, temperature indication, and visual interaction.

[0003] Among known technical approaches, directly loading thermochromic pigments or dyes onto the substrate through coating, padding, or blend spinning is the most common method. However, this direct, exposed addition method has revealed many drawbacks in actual production and application. First, the color-changing performance of thermochromic dyes is highly dependent on the chemical microenvironment of their ternary system, making them extremely sensitive to chemical auxiliaries such as acids, alkalis, metal ions, and surfactants. They are easily damaged and irreversibly lose their color-changing ability during spinning solutions, coagulation baths, or finishing processes. Second, unprotected color-changing components have poor dispersibility in the fiber matrix. During use, they are prone to leakage and migration when subjected to friction, rubbing, and repeated immersion in essence, which not only significantly shortens the color-changing lifespan but also poses safety hazards when in contact with skin, limiting their application in high-end skin-friendly products. Summary of the Invention

[0004] To improve the stability and safety of thermochromic dyes in the application of facial mask base fabric, this application provides a thermochromic facial mask base fabric and its preparation method.

[0005] In the first aspect, this application provides a method for preparing a thermally sensitive thermochromic mask base fabric, which adopts the following technical solution: A method for preparing a thermosensitive thermochromic mask base fabric includes the following steps: S1. Thoroughly homogenize and mix sodium alginate aqueous solution with microencapsulated thermochromic dye, and stir until the system is evenly dispersed to obtain mixed spinning solution; S2. After vacuum degassing of the mixed spinning solution, wet spinning is performed to obtain nascent fibers. S3. After the nascent fibers are stretched, cut to length, and dried and shaped, the heat-sensitive thermochromic mask base fabric is obtained.

[0006] By adopting the above technical solution, the thermochromic dye is microencapsulated, isolating it from the external environment. This not only avoids the risk of dye contact with the skin but also protects the dye from the effects of acids, alkalis, oxidation, and microbial degradation, thus extending the lifespan of the thermochromic function. Furthermore, by mixing the microencapsulated thermochromic dye with a sodium alginate solution, the dye is evenly dispersed in the sodium alginate aqueous solution. Then, through wet spinning, the microencapsulated thermochromic dye is embedded in situ into the fiber, ensuring that the mask base fabric can change color as a whole, with ideal color fastness.

[0007] Preferably, the microencapsulated thermochromic dye comprises a thermochromic core material and a microcapsule wall material covering the outside of the thermochromic core material. The thermochromic core material comprises the following components in parts by weight: 1-3 parts of propyl gallate, 3-6 parts of fluorane pink leuco dye, and 91-96 parts of solvent, wherein the solvent is at least one of long-chain fatty alcohols and higher fatty acid esters.

[0008] By employing the above technical solution, fluorane-based pink leuco dyes provide color, while propyl gallate provides an acidic environment to trigger and maintain the color-changing reaction of the fluorane-based pink leuco dyes. The solvent controls the color-changing "switch" temperature. When the temperature is below the melting point, the solvent is solid, and the fluorane-based pink leuco dyes are in close contact with propyl gallate. The fluorane-based pink leuco dyes gain electrons from propyl gallate, causing the mask base fabric to appear pink. When the temperature is above the melting point, the solvent melts, causing the fluorane-based pink leuco dyes to separate from the propyl gallate. The structure of the fluorane-based pink leuco dyes closes, causing the mask base fabric to become colorless, thus achieving the color-changing effect of the mask base fabric.

[0009] At the same time, propyl gallate is safer than traditional bisphenol A. Furthermore, propyl gallate can also act as an antioxidant to protect fluorescein pink leuco dyes, making the color change more durable and less prone to failure.

[0010] Preferably, the solvent is a complex of tetradecyl alcohol, hexadecyl alcohol and butyl stearate, wherein the mass ratio of tetradecyl alcohol, hexadecyl alcohol and butyl stearate is 25-40:35-50:10-30.

[0011] By adopting the above technical solution, tetradecyl alcohol, hexadecyl alcohol and butyl stearate are selected as solvents. Tetradecyl alcohol can provide the basis for phase change, and its structure is crystalline cortisol with good skin affinity. The addition of butyl stearate serves as a low melting point component, which lowers the phase change temperature of the overall system and ensures that the mask base fabric can maintain a complete pink color state under room temperature conditions. Hexadecyl alcohol itself has a high melting point, which can improve the thermal stability of the system.

[0012] Preferably, the microcapsule wall material is a CMC-chitosan composite material.

[0013] By adopting the above technical solution, the addition of CMC shows good affinity with sodium alginate, enabling it to form a hydrogen bond network with the sodium alginate matrix. This allows the microencapsulated thermochromic dyes to be tightly anchored inside the fiber. Furthermore, through the introduction of chitosan, during the wet spinning process, since the coagulation bath commonly used for sodium alginate fibers contains calcium ions, CMC, as an anionic polyelectrolyte, can react with the calcium ions in the coagulation bath. 2+ Ionic crosslinking occurs to form a dense gel. At the same time, the amino groups of chitosan can be protonated and become positively charged in the acidic spinning solution, and then electrostatically recombine with the negatively charged CMC to further strengthen the wall material and form a dense outer shell, reducing the probability of temperature-sensitive core material loss.

[0014] Furthermore, the amino groups on the chitosan molecular chain can be protonated to -NH3+ in the weakly acidic environment of the microcapsule preparation, enabling chitosan to continuously provide the paper-like, micro-etched propyl gallate-reducing environment required for the temperature-sensitive core material region, thus ensuring the sensitivity of the color development reaction.

[0015] Preferably, the preparation method of the microencapsulated thermochromic dye includes the following steps: Core material preparation: Propyl gallate, fluorane pink leuco dye and solvent are mixed according to the formula amount, heated and stirred until completely melted to obtain a premixed solution, and the premixed solution is slowly added dropwise to an emulsifier aqueous solution and homogenized to obtain a core material emulsion; Wall material preparation: After mixing CMC solution and chitosan solution evenly, a compound wall material solution is obtained; Coagulation and coating: Under stirring, the compound wall material solution is added dropwise to the core material emulsion. After the addition is complete, the pH is adjusted to 4-5, and the mixture is kept at 50-60℃ and stirred to obtain a microcapsule suspension. Curing and post-treatment: Dilute alkali solution is added to the microcapsule suspension to adjust the pH to 8-9. After centrifugation, filtration, washing, and finally drying, the microencapsulated thermochromic dye is obtained.

[0016] Preferably, in the curing and post-treatment steps, after adjusting the pH to 8-9, an aqueous solution of sodium alginate is added, and the mixture is stirred at 40-50℃ for 30-60 minutes. Then, after centrifugation, filtration, washing, and finally drying, microencapsulated thermochromic dye is obtained.

[0017] By adopting the above technical solution, through the addition of sodium alginate aqueous solution, during the spinning process, the sodium alginate segments on the surface of the microencapsulated thermochromic dye can be cross-linked with the free sodium alginate segments in the spinning solution by calcium ions, thereby achieving chemical anchoring of the microencapsulated thermochromic dye in the fiber network, enabling the microencapsulated thermochromic dye to serve as a cross-linking point and improve the toughness of the fiber.

[0018] Preferably, gelatin is also added to S1.

[0019] By adopting the above technical solution, gelatin and sodium alginate are both natural polymers. At low temperatures, gelatin can physically gel and form a double-network precursor with the ionic gel of sodium alginate. Furthermore, the gelatin molecular chain contains a large number of -NH4+ molecules. 2 And -COOH, can react with the -COO of sodium alginate - Through electrostatic interaction and hydrogen bonding, a polyelectrolyte complex is formed. During wet spinning, the gelatin enters a calcium chloride coagulation bath, cools and shrinks, and forms an interpenetrating structure with calcium alginate, which significantly improves the toughness of the fiber.

[0020] Preferably, the mass ratio of sodium alginate to gelatin is 1:0.3-1.

[0021] Preferably, the draw ratio is 1.5-3 times.

[0022] Secondly, the thermally sensitive thermochromic mask base fabric provided in this application adopts the following technical solution: A thermosensitive thermochromic mask base fabric is prepared by the above-mentioned method for preparing a thermosensitive thermochromic mask base fabric.

[0023] In summary, this application includes at least one of the following beneficial technical effects: 1. This application isolates thermochromic dyes from contact with the external environment by microencapsulating them. This not only avoids the risk of dye contact with the skin, but also protects the dyes from the effects of acids, alkalis, oxidation, and microbial degradation, thus extending the service life of the thermochromic function. Furthermore, by mixing the microencapsulated thermochromic dyes with sodium alginate solution, the microencapsulated thermochromic dyes are evenly dispersed in the sodium alginate aqueous solution. Then, through wet spinning, the microencapsulated thermochromic dyes are embedded in situ into the fiber, ensuring that the mask base fabric can change color as a whole, and the color fastness is ideal. 2. In this application, sodium alginate aqueous solution is added during the preparation of microencapsulated thermochromic dye. During the spinning process, the sodium alginate segments on the surface of the microencapsulated thermochromic dye can be cross-linked by calcium ions together with the free sodium alginate segments in the spinning solution, thereby achieving chemical anchoring of the microencapsulated thermochromic dye in the fiber network. This allows the microencapsulated thermochromic dye to act as a cross-linking point, improving the fiber's breaking strength and modulus. 3. This application utilizes the addition of gelatin. Gelatin and sodium alginate are both natural polymers. At low temperatures, gelatin can physically gel and form a double-network precursor with the ionic gel of sodium alginate. Furthermore, the gelatin molecular chain contains a large number of -NH4+ molecules. 2 And -COOH, can react with the -COO of sodium alginate - Through electrostatic interaction and hydrogen bonding, a polyelectrolyte complex is formed. During wet spinning, the gelatin enters a calcium chloride coagulation bath, cools and shrinks, and forms an interpenetrating structure with calcium alginate, which significantly improves the toughness of the fiber. Detailed Implementation

[0024] The raw materials in this application include the following: Propyl gallate: The commercially available product with product number S30156 from Shanghai Yuanye Biotechnology Co., Ltd. is used; Fluorescein color-changing dyes: Commercially available products from Wuhan Shuer Biotechnology Co., Ltd. with CAS number 42228-32-0 were used; Nonionic emulsifiers: This application takes a commercially available product with CAS number 9002-93-1 as an example; CMC: Select CMC with a degree of substitution of 0.8 and a viscosity of 500 mPa·s; Thermochromic dye: The commercially available product DC red 21 from Shanghai Mengdihu Industrial Co., Ltd. is used.

[0025] Preparation Example 1 The preparation method of microencapsulated thermochromic dyes includes the following steps: Core material preparation: 9g of propyl gallate, 4g of fluorane color-changing dye and 87g of solvent were mixed and heated to 100℃ and stirred until completely melted to obtain a premix. The premix was slowly added dropwise to an emulsifier aqueous solution and homogenized at 10000rpm for 15min. The mixture was then kept at 50℃ to obtain a core material emulsion. Wall material preparation: Take CMC to prepare a CMC aqueous solution with a mass fraction of 2%, take chitosan to dissolve in a 1% acetic acid aqueous solution to prepare a chitosan solution with a mass fraction of 2%, and mix the CMC aqueous solution and chitosan solution in equal mass until uniform to obtain the composite wall material solution; Coagulation and coating: Under stirring, the compound wall material solution is added dropwise to the core material emulsion. After the addition is complete, the pH is adjusted to 4.5, and the mixture is kept at 50°C and stirred for 2 hours to obtain a microcapsule suspension. The mass ratio of the compound wall material solution to the core material solution is 2:1. Curing and post-treatment: 0.5 mol / L sodium hydroxide was added to the microcapsule suspension to adjust the pH to 8.5. After cooling to room temperature, the mixture was centrifuged at 5000 rpm for 10 min, the supernatant was discarded, and the mixture was washed repeatedly with deionized water and centrifuged 3 times. The mixture was then vacuum dried at -50℃ for 24 h to obtain microencapsulated thermochromic dyes with an average particle size of 5 μm.

[0026] The solution is a mixture of tetradecyl alcohol, hexadecyl alcohol and butyl stearate, with a mass ratio of 35:40:20. The emulsifier aqueous solution is a nonionic emulsifier aqueous solution with a mass fraction of 2%.

[0027] Preparation Examples 2-3 Preparation Examples 2-3 are based on the preparation method of Preparation Example 1, but the weight parts of the thermochromic core material components are adjusted as shown in Table 1.

[0028] Preparation Examples 4-5 Preparation Examples 4-5 are based on the preparation method of Preparation Example 1, but the solvent is adjusted as shown in Table 1.

[0029] Preparation Example 6 Preparation Example 6, based on the preparation method of Preparation Example 1, further includes the addition of sodium alginate aqueous solution during curing and post-treatment. The specific steps of curing and post-treatment are as follows: 2% sodium alginate aqueous solution by mass is slowly added dropwise to the microcapsule suspension, stirred for 50 min, followed by the addition of 0.5 mol / L sodium hydroxide to adjust the pH to 8.5. After cooling to room temperature, the mixture is centrifuged at 5000 rpm for 10 min, the supernatant is discarded, and the mixture is repeatedly washed with deionized water and centrifuged 3 times. Then, it is vacuum dried at -50℃ for 24 h to obtain the microencapsulated thermochromic dye. The amount of sodium alginate added is 20% of the core material mass, and the other conditions remain unchanged.

[0030] Table 1. Composition of microencapsulated thermochromic dyes prepared in Examples 1-5

[0031] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0032] Example 1

[0033] A method for preparing a thermosensitive thermochromic mask base fabric includes the following steps: S1. Disperse a 4% sodium alginate aqueous solution with the microencapsulated thermochromic dye obtained in Preparation Example 1 at 5000 rpm for 20 min, mix thoroughly and homogeneously, and stir until the system is uniformly dispersed to obtain a mixed spinning solution. The amount of microencapsulated thermochromic dye added is 10% of the mass of sodium alginate. S2. After the mixed spinning solution is degassed at 30°C under a vacuum of -0.08MPa for 3 hours, the mixed spinning solution is precisely injected into the spinneret through a metering pump and sprayed into the coagulation bath under an extrusion pressure of 0.5MPa to obtain nascent fibers. The nascent fibers are then placed in a primary hot water drawing bath at 50°C and plastically stretched at a draw ratio of 2.5. After washing, they are cut to a fixed length of 45mm and then dried and shaped at 50°C to obtain the thermally sensitive thermochromic mask base fabric. The coagulation bath is a calcium chloride aqueous solution with a mass fraction of 4%.

[0034] Comparative Example 1 Comparative Example 1 was prepared using the same method as in Example 1, but with the microencapsulated thermochromic dye replaced by an equal amount of thermochromic dye, while all other conditions remained unchanged.

[0035] Performance testing The thermally sensitive thermochromic mask base fabrics of Example 1 and Comparative Example 1 were analyzed using the following specific testing methods: 1. Anti-irritant performance test Twenty male and twenty female volunteers with sensitive skin were selected for each group. Each group of volunteers used the heat-sensitive thermochromic mask base fabric from Example 1 and Comparative Example 1 for seven consecutive days, once in the morning and once in the evening. On the eighth day, the irritation level of the mask was tested on each user, and the results are shown in Table 2. The irritation coefficient R value is calculated as 100% * number of people experiencing discomfort or allergic symptoms / number of test subjects; a higher coefficient indicates stronger irritation.

[0036] 2. Color difference retention rate Record the color value of the thermochromic mask base fabric sample at 25℃, then attach it to a hot plate at 38℃ for 30s and measure the color value after the color change. Calculate the color difference value ΔE0. Then, alternately place the thermochromic mask base fabric sample at 25℃ and 38℃ for 30s each as one cycle. Measure the color difference ΔE after 1000 cycles to obtain the color difference retention rate. Color difference retention rate = (ΔE / ΔE0) × 100%.

[0037] 3. Wash fastness test The thermochromic membrane to be tested was washed in water at 60℃ and 60rpm for 3 hours. The integrity of the thermochromic layer was then observed: if the thermochromic layer was intact and there were no signs of peeling, it was rated as excellent; if the thermochromic layer was intact but there were gaps between it and the skin-friendly membrane, it was rated as good; if the thermochromic layer peeled off, it was rated as poor.

[0038] Based on the above detection method, the test results of Example 1 and Comparative Example 1 were obtained, as shown in Table 2 below.

[0039] Table 2 Performance test results for Example 1 and Comparative Example 1

[0040] Referring to Table 2, comparing Example 1 and Comparative Example 1, it can be seen that the thermally sensitive thermochromic mask base fabric of Example 1 has better performance. This may be because by microencapsulating the thermochromic dye, the thermochromic dye is isolated from the external environment. This not only avoids the risk of dye contact with the skin, but also protects the dye from the effects of acid, alkali, oxidation, and microbial degradation, thus extending the service life of the thermochromic function. Furthermore, by mixing the microencapsulated thermochromic dye with sodium alginate solution, the microencapsulated thermochromic dye is evenly dispersed in the sodium alginate aqueous solution. Then, through wet spinning, the microencapsulated thermochromic dye is embedded in situ into the fiber, ensuring that the mask base fabric can change color as a whole, and the color fastness is ideal.

[0041] Examples 2-6 Examples 2-6 are based on the preparation method of Example 1, with adjustments made to the microencapsulated thermochromic dyes, as shown in Table 1.

[0042] Performance testing The thermally sensitive color-changing mask base fabrics of Examples 1-6 were analyzed, and the specific testing methods are as follows: 1. Color change temperature The color change temperature of the thermochromic mask base fabric was tested according to the standard test method specified in GB / T 39801-2021.

[0043] 2. Toughness The toughness of the thermosensitive thermochromic mask base fabric was tested according to the standard test method specified in GB / T 24218.3-2010.

[0044] Based on the above detection method, the test results of Examples 1-6 were obtained, as shown in Table 3 below.

[0045] Table 3 Performance Test Tables for Examples 1-6

[0046] Referring to Table 3, a comparison of Examples 1-5 shows that the performance of the thermochromic mask base fabric of Example 1 is significantly better than that of the thermochromic mask base fabrics of Examples 2-5, and the color-changing temperature is closer to human body temperature. A comparison of Examples 1 and 6 shows that the performance of the thermochromic mask base fabric of Example 6 is better than that of Example 1. This may be due to the addition of sodium alginate aqueous solution. During the spinning process, the sodium alginate segments on the surface of the microencapsulated thermochromic dye can be cross-linked with the free sodium alginate segments in the spinning solution by calcium ions, thereby achieving chemical anchoring of the microencapsulated thermochromic dye in the fiber network. This allows the microencapsulated thermochromic dye to act as a cross-linking point, improving the fiber's toughness.

[0047] Example 7

[0048] In Example 7, based on the preparation method of Example 1, gelatin was added in S1, with the mass ratio of gelatin to sodium alginate being 0.6:1, and the other conditions remained unchanged.

[0049] Examples 8-11 Examples 8-11 are based on the preparation method of Example 7, but the mass ratio of gelatin to sodium alginate is adjusted as shown in Table 4.

[0050] The thermally sensitive thermochromic mask base fabrics of Examples 7-11 were subjected to the above performance tests, and the test results are shown in Table 4.

[0051] Table 4. Mass ratio of gelatin to sodium alginate and its performance test results in Examples 1 and 7-11.

[0052] Referring to Table 4, comparing Example 1 and Examples 7-11, it can be seen that the addition of gelatin can significantly improve the performance of the thermosensitive mask base fabric. Furthermore, when the mass ratio of gelatin to sodium alginate is 0.3-1:1, especially when the mass ratio of gelatin to sodium alginate is 0.6:1, the performance of the resulting thermosensitive mask base fabric is optimal.

[0053] Examples 12-15 Examples 12-15 are based on the preparation method of Example 1, but the stretching ratio in S3 is adjusted, as shown in Table 5.

[0054] Performance testing The thermally sensitive mask base fabrics of Examples 1 and 12-15 were analyzed using the following specific testing methods: 1. Elastic modulus The elastic modulus of the base fabric of the thermosensitive facial mask was tested according to the standard test method specified in GB / T 14337.

[0055] Based on the above detection method, the test results of Examples 1 and 12-15 were obtained, as shown in Table 5 below.

[0056] Table 5. Stretch ratio and performance test results for Examples 1 and 12-15.

[0057] Referring to Table 5, a comparison of Examples 1 and 12-15 shows that the thermally sensitive thermochromic mask base fabric exhibits the best performance when the stretch ratio is in the range of 1.5-3 times, especially when the stretch ratio is 2.5.

[0058] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a thermosensitive thermochromic mask base fabric, characterized in that, Includes the following steps: S1. Thoroughly homogenize and mix sodium alginate aqueous solution with microencapsulated thermochromic dye, and stir until the system is evenly dispersed to obtain mixed spinning solution; S2. After vacuum degassing of the mixed spinning solution, wet spinning is performed to obtain nascent fibers. S3. After the nascent fibers are stretched, cut to length, and dried and shaped, the heat-sensitive thermochromic mask base fabric is obtained.

2. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 1, characterized in that, The microencapsulated thermochromic dye includes a thermochromic core material and a microcapsule wall material covering the outside of the thermochromic core material. The thermochromic core material includes the following components in parts by weight: 4-15 parts of propyl gallate, 3-6 parts of fluorane color-changing dye, and 79-93 parts of solvent, wherein the solvent is at least one of long-chain fatty alcohols and higher fatty acid esters.

3. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 2, characterized in that, The solvent is a complex of tetradecyl alcohol, hexadecyl alcohol and butyl stearate, wherein the mass ratio of tetradecyl alcohol, hexadecyl alcohol and butyl stearate is 25-40:35-50:10-30.

4. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 2, characterized in that, The microcapsule wall material is a CMC-chitosan composite material.

5. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 4, characterized in that, The preparation method of the microencapsulated thermochromic dye includes the following steps: Core material preparation: Propyl gallate, fluorane color-changing dye and solvent are mixed according to the formula amount, heated and stirred until completely melted to obtain a premixed liquid. The premixed liquid is slowly added dropwise to an emulsifier aqueous solution and homogenized and emulsified to obtain a core material emulsion. Wall material preparation: After mixing CMC solution and chitosan solution evenly, a compound wall material solution is obtained; Coagulation and coating: Under stirring, the compound wall material solution is added dropwise to the core material emulsion. After the addition is complete, the pH is adjusted to 4-5, and the mixture is kept at 50-60℃ and stirred to obtain a microcapsule suspension. Curing and post-treatment: Dilute alkali solution is added to the microcapsule suspension to adjust the pH to 8-9. After centrifugation, filtration, washing, and finally drying, the microencapsulated thermochromic dye is obtained.

6. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 5, characterized in that, In the curing and post-treatment steps, after adjusting the pH to 8-9, sodium alginate aqueous solution is added, and the mixture is stirred at 40-50℃ for 30-60 minutes. After centrifugation, filtration, washing, and finally drying, microencapsulated thermochromic dye is obtained.

7. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 1, characterized in that, Gelatin is also added to S1.

8. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 7, characterized in that, The mass ratio of sodium alginate to gelatin is 1:0.3-1.

9. The method for preparing a thermosensitive thermochromic mask base fabric according to claim 1, characterized in that, In S3, the draw ratio is 1.5-3 times.

10. A thermosensitive thermochromic mask base fabric, characterized in that, It is prepared by the method for preparing a thermosensitive thermochromic mask base fabric according to any one of claims 1-9.

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