A hydrogel-type colored and stable facial mask base fabric and preparation method thereof

Abstract

The present invention relates to the technical field of facial mask base fabrics, and discloses a hydrogel-based, color-stable facial mask base fabric and a preparation method thereof. The facial mask base fabric prepared by the present invention is made from lignin-based hydrogel short fibers and bamboo fibers as main raw materials, and is formed into a fiber web through opening, mixing, carding, and web laying. The fiber web is then pre-wetted, subjected to high-pressure hydroentanglement, dehydrated, and dried. The facial mask base fabric not only has excellent liquid holding rate and liquid retention rate, and can increase the skin's moisture content after application, but also has excellent antioxidant properties, color stability, and breaking strength.

Description

Technical Field

[0001] The invention relates to the technical field of facial mask base fabrics, and in particular to a hydrogel-type facial mask base fabric with stable coloring and a preparation method thereof. Background Art

[0002] As consumers' demand for skincare benefits and user experiences continues to rise, facial masks, a crucial part of daily skincare routines, are experiencing a continuous evolution in their base fabric materials. Traditional non-woven facial mask base fabrics suffer from issues such as easy dripping of essences and poor skin adhesion. Hydrogel-based facial mask base fabrics, however, have become a research hotspot due to their superior properties. Hydrogel-based facial mask base fabrics offer advantages such as high water content, excellent skin adhesion, excellent biocompatibility, and a mild, non-irritating effect on the skin.

[0003] Traditional hydrogel-based facial mask base fabrics still have some defects, such as: (1) facial mask base fabrics are mostly transparent or white, which makes it difficult to meet consumers' demand for color and aesthetics; (2) facial mask base fabrics do not have antioxidant properties, which cannot meet consumers' needs for antioxidant skin care. It is difficult to neutralize free radicals on the skin surface and slow down skin oxidative damage. Therefore, it is necessary to develop a facial mask base fabric with antioxidant properties, color stability and other functions to meet the demand for high-efficiency skin care products. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a hydrogel-type colored and stable facial mask base fabric and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A hydrogel-type colored and stable facial mask base fabric is prepared by mixing lignin-based hydrogel short fibers and bamboo fibers into a fiber web, which is then processed by hydroentanglement;

[0007] The lignin-based hydrogel short fibers are prepared by the following steps:

[0008] Step A1: Under nitrogen, diethanolamine, p-aminobenzoic acid, and p-toluenesulfonic acid were mixed, heated to 100°C, and stirred for 20 minutes. Cyclohexane was added, and the mixture was heated to 140°C for 1 hour. The mixture was then vacuum-dried for 2 hours and purified to obtain an amino-terminated product.

[0009] Furthermore, in step A1, the molar ratio of diethanolamine to p-aminobenzoic acid is 1:2, and the amounts of p-toluenesulfonic acid and cyclohexane are 0.5% and 50% of the total mass of diethanolamine and p-aminobenzoic acid, respectively;

[0010] Step A2, mixing sodium lignin sulfonate, amino-terminated product, sodium hydroxide and water, and heating to 85° C., adding 25-35 wt % formaldehyde aqueous solution dropwise, condensing and reflux for 3-5 hours, adding 1 mol / L hydrochloric acid until no precipitate is formed, filtering, washing, drying and grinding to obtain pretreated sodium lignin sulfonate;

[0011] Furthermore, in step A2, the ratio of sodium lignin sulfonate, amino-terminated product, sodium hydroxide, water and formaldehyde aqueous solution is 10 g: 2-4 g: 0.3-0.5 g: 50 mL: 4-6 mL;

[0012] Step A3, mixing lipoic acid, sodium hydroxide and water and stirring for 30 minutes, adding N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide and stirring for 1-2 hours, then adding 2-4 wt% pre-treated sodium lignin sulfonate aqueous solution and ethanol, stirring vigorously for 12-16 hours, and rotary evaporation to obtain sodium lignin disulfide;

[0013] Furthermore, in step A3, the ratio of lipoic acid, sodium hydroxide, water, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, pre-treated sodium lignin sulfonate aqueous solution and ethanol is 0.1-0.2 mol:4-8 g:100 mL:0.1-0.2 mol:0.05-0.1 mol:50 mL:50 mL;

[0014] Step A4: dimethylsiloxane, methyltrimethoxysilane, potassium hydroxide, water, and ethanol are mixed and stirred at 50-60° C. for 2-4 hours, then heated to 120° C. for reaction for 30-50 minutes, cyclohexane and a cation exchange resin are added, filtered, and distilled to collect the organosilicon; the organosilicon, sodium disulfide lignin sulfonate, modified carbon black, polyvinyl alcohol, and water are mixed to obtain a spinning solution, which is then spun into a 35 wt% glutaraldehyde aqueous solution through a spinning machine and soaked for 2 hours. After removal, the fibers are freeze-dried and cut to obtain lignin-based hydrogel staple fibers;

[0015] Furthermore, in step A4, the mass ratio of dimethylsiloxane, methyltrimethoxysilane, potassium hydroxide, water, ethanol, cyclohexane and cation exchange resin in the organosilicon is 5-10:2-4:0.01:2-3:7:30:3-6;

[0016] Furthermore, in step A4, the mass ratio of organosilicon, sodium disulfide lignin sulfonate, modified carbon black, polyvinyl alcohol and water in the lignin-based hydrogel short fibers is 1-2:10-15:0.5-1:3-5:300;

[0017] Furthermore, the modified carbon black is prepared by the following steps: mixing carbon black, buffer solution and chitosan solution, stirring for 2-3 hours, centrifuging, washing and drying to obtain the modified carbon black;

[0018] Furthermore, the buffer in the modified carbon black is a phosphate buffer with a pH of 7.6;

[0019] Furthermore, the chitosan solution in the modified carbon black is prepared by mixing chitosan and water in a mass ratio of 0.2-0.5:10, and the pH of the chitosan solution is 5;

[0020] Furthermore, the usage ratio of carbon black, buffer solution and chitosan solution in the modified carbon black is 2-5g:50mL:10g.

[0021] A method for preparing a hydrogel-type colored and stable facial mask base fabric comprises the following steps:

[0022] The bamboo fibers are cut and opened and mixed with lignin-based hydrogel short fibers to obtain mixed short fibers, and the mixed short fibers are combed and laid to obtain a fiber web, and the fiber web is pre-wetted, subjected to high-pressure water entanglement, dehydrated, and dried to obtain a hydrogel-type colored and stable facial mask base fabric;

[0023] Furthermore, the mass ratio of the bamboo fiber to the lignin-based hydrogel short fiber is 5-8:2-5.

[0024] Beneficial effects of the present invention:

[0025] The facial mask base cloth prepared by the present invention uses lignin-based hydrogel short fibers and bamboo fibers as main raw materials, and is made into a fiber web through opening, mixing, carding, and laying, and then the fiber web is prepared through pre-wetting, high-pressure water spunlace, dehydration, and drying processes; the facial mask base cloth not only has excellent liquid holding rate and liquid retention rate, but also can make the skin have a higher water content after being applied to the skin, and also has excellent antioxidant performance, coloring stability and breaking strength.

[0026] The lignin-based hydrogel staple fibers in the facial mask base fabric of the present invention are prepared using sodium disulfide lignin sulfonate as the main raw material, with the addition of organic silicon, modified carbon black, polyvinyl alcohol and other raw materials. Among them, lipoic acid with strong oxidizing properties is introduced into the sodium disulfide lignin sulfonate, which can synergistically act with the phenolic hydroxyl group in the sodium lignin sulfonate to remove free radicals on the skin surface and reduce skin aging caused by oxidation. At the same time, the introduction of disulfide bonds can also increase the flexibility and elasticity of the facial mask base fabric, making it better fit the skin; and the introduction of organic silicon and benzene ring structures can improve the mechanical properties of the facial mask base fabric, avoiding breakage or deformation caused by tearing or pulling during use. Carbon black, as a colorant, has poor dispersibility in hydrogels, resulting in unstable coloring in the hydrogel. By coating the carbon black with chitosan, the macromolecular structure of chitosan can be used to form a protective layer around the carbon black particles, increasing the steric hindrance between the particles and preventing them from agglomerating, thereby improving dispersibility. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] Example 1: Modified carbon black was prepared by the following steps: 2 g of carbon black, 50 mL of phosphate buffer solution with a pH of 7.6 and 10 g of chitosan solution were mixed, stirred for 2 h, centrifuged, washed and dried to obtain modified carbon black. The chitosan solution was prepared by mixing chitosan and water in a mass ratio of 0.2:10, and the pH of the chitosan solution was 5.

[0029] Lignin-based hydrogel short fibers were prepared by the following steps:

[0030] Step A1: Under nitrogen, 0.1 mol of diethanolamine, 0.2 mol of p-aminobenzoic acid, and p-toluenesulfonic acid were mixed, heated to 100°C, and stirred for 20 minutes. After adding cyclohexane, the mixture was heated to 140°C for 1 hour, and then vacuum-dried for 2 hours. Purification was performed to obtain an amino-terminated product, in which p-toluenesulfonic acid and cyclohexane accounted for 0.5% and 50% of the total mass of diethanolamine and p-aminobenzoic acid, respectively.

[0031] Step A2, 10g of sodium lignin sulfonate, 2g of amino-terminated product, 0.3g of sodium hydroxide and 50mL of water were mixed evenly, and the temperature was raised to 85°C, 4mL of 25wt% formaldehyde aqueous solution was added dropwise, condensed and refluxed for 3h, 1mol / L hydrochloric acid was added until no precipitate was precipitated, filtered, washed, dried and ground to obtain pre-treated sodium lignin sulfonate;

[0032] Step A3, 0.1 mol of lipoic acid, 4 g of sodium hydroxide and 100 mL of water were mixed and stirred for 30 min, 0.1 mol of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.05 mol of N-hydroxysuccinimide were added and stirred for 1 h, and then 50 mL of a 2 wt% aqueous solution of pretreated sodium lignin sulfonate and 50 mL of ethanol were added, and the mixture was vigorously stirred for 12 h, and rotary evaporated to obtain sodium lignin disulfide;

[0033] Step A4, 5g of dimethylsiloxane, 2g of methyltrimethoxysilane, 0.01g of potassium hydroxide, 2g of water and 7g of ethanol were mixed and stirred at 50°C for 2h, then heated to 120°C for reaction for 30min, 30g of cyclohexane and 3g of cation exchange resin were added, filtered and distilled to collect the organosilicon; 1g of organosilicon, 10g of sodium disulfide lignin sulfonate, 0.5g of modified carbon black, 3g of polyvinyl alcohol and 300g of water were mixed to obtain a spinning solution, which was then spun into a 35wt% glutaraldehyde aqueous solution through a spinning machine and soaked for 2h. After taking out, freeze-dried and cut to obtain lignin-based hydrogel short fibers.

[0034] Example 2: Modified carbon black was prepared by the following steps: 3.5 g of carbon black, 50 mL of phosphate buffer solution with a pH of 7.6 and 10 g of chitosan solution were mixed, stirred for 2.5 h, centrifuged, washed and dried to obtain modified carbon black. The chitosan solution was prepared by mixing chitosan and water in a mass ratio of 0.35:10, and the pH of the chitosan solution was 5.

[0035] Lignin-based hydrogel short fibers were prepared by the following steps:

[0036] Step A1: Under nitrogen, 0.1 mol of diethanolamine, 0.2 mol of p-aminobenzoic acid, and p-toluenesulfonic acid were mixed, heated to 100°C, and stirred for 20 minutes. After adding cyclohexane, the mixture was heated to 140°C for 1 hour, and then vacuum-dried for 2 hours. Purification was performed to obtain an amino-terminated product, in which p-toluenesulfonic acid and cyclohexane accounted for 0.5% and 50% of the total mass of diethanolamine and p-aminobenzoic acid, respectively.

[0037] Step A2, 10g of sodium lignin sulfonate, 3g of amino-terminated product, 0.4g of sodium hydroxide and 50mL of water were mixed evenly, and the temperature was raised to 85°C, 5mL of 30wt% formaldehyde aqueous solution was added dropwise, condensed and refluxed for 4h, 1mol / L hydrochloric acid was added until no precipitate was precipitated, filtered, washed, dried and ground to obtain pre-treated sodium lignin sulfonate;

[0038] Step A3, 0.15 mol of lipoic acid, 6 g of sodium hydroxide and 100 mL of water were mixed and stirred for 30 min, 0.15 mol of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.075 mol of N-hydroxysuccinimide were added and stirred for 1.5 h, and then 50 mL of a 3 wt% aqueous solution of pretreated sodium lignin sulfonate and 50 mL of ethanol were added, and the mixture was vigorously stirred for 14 h, and rotary evaporated to obtain sodium lignin disulfide;

[0039] Step A4, 7.5g of dimethylsiloxane, 3g of methyltrimethoxysilane, 0.01g of potassium hydroxide, 2.5g of water and 7g of ethanol were mixed and stirred at 55°C for 3h, then heated to 120°C for reaction for 40min, 30g of cyclohexane and 4.5g of cation exchange resin were added, filtered and distilled to collect the organosilicon; 1.5g of organosilicon, 12g of sodium disulfide lignin sulfonate, 0.75g of modified carbon black, 4g of polyvinyl alcohol and 300g of water were mixed to obtain a spinning solution, which was then spun into a 35wt% glutaraldehyde aqueous solution through a spinning machine and soaked for 2h. After taking out, freeze-dried and cut to obtain lignin-based hydrogel short fibers.

[0040] Example 3: Modified carbon black was prepared by the following steps: 5 g of carbon black, 50 mL of phosphate buffer solution with a pH of 7.6 and 10 g of chitosan solution were mixed, stirred for 3 h, centrifuged, washed and dried to obtain modified carbon black. The chitosan solution was prepared by mixing chitosan and water in a mass ratio of 0.5:10, and the pH of the chitosan solution was 5.

[0041] Lignin-based hydrogel short fibers were prepared by the following steps:

[0042] Step A1: Under nitrogen, 0.1 mol of diethanolamine, 0.2 mol of p-aminobenzoic acid, and p-toluenesulfonic acid were mixed, heated to 100°C, and stirred for 20 minutes. After adding cyclohexane, the mixture was heated to 140°C for 1 hour, and then vacuum-dried for 2 hours. Purification was performed to obtain an amino-terminated product, in which p-toluenesulfonic acid and cyclohexane accounted for 0.5% and 50% of the total mass of diethanolamine and p-aminobenzoic acid, respectively.

[0043] Step A2, 10g of sodium lignin sulfonate, 4g of amino-terminated product, 0.5g of sodium hydroxide and 50mL of water were mixed evenly, and the temperature was raised to 85°C, 6mL of 35wt% formaldehyde aqueous solution was added dropwise, condensed and refluxed for 5h, 1mol / L hydrochloric acid was added until no precipitate was precipitated, filtered, washed, dried and ground to obtain pretreated sodium lignin sulfonate;

[0044] Step A3, 0.2 mol of lipoic acid, 8 g of sodium hydroxide and 100 mL of water were mixed and stirred for 30 min, 0.2 mol of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 0.1 mol of N-hydroxysuccinimide were added and stirred for 2 h, and then 50 mL of a 4 wt% aqueous solution of pretreated sodium lignin sulfonate and 50 mL of ethanol were added, and the mixture was vigorously stirred for 16 h, and rotary evaporated to obtain sodium lignin disulfide;

[0045] Step A4, 10g of dimethylsiloxane, 4g of methyltrimethoxysilane, 0.01g of potassium hydroxide, 3g of water and 7g of ethanol were mixed and stirred at 60°C for 4h, then heated to 120°C for reaction for 50min, 30g of cyclohexane and 6g of cation exchange resin were added, filtered and distilled to collect the organosilicon; 2g of organosilicon, 15g of sodium disulfide lignin sulfonate, 1g of modified carbon black, 5g of polyvinyl alcohol and 300g of water were mixed to obtain a spinning solution, which was then spun into a 35wt% glutaraldehyde aqueous solution through a spinning machine and soaked for 2h. After taking out, freeze-dried and cut to obtain lignin-based hydrogel short fibers.

[0046] Example 4: A method for preparing a hydrogel-type colored and stable facial mask base fabric comprises the following steps:

[0047] The cut bamboo fiber is opened and mixed with the lignin-based hydrogel staple fiber prepared in Example 1 to obtain mixed staple fibers. The mixed staple fibers are then combed and laid to obtain a fiber web. The fiber web is then pre-wetted, subjected to high-pressure water entanglement, dehydrated, and dried to obtain a hydrogel-type, colored and stable facial mask base fabric. The mass ratio of bamboo fiber to lignin-based hydrogel staple fibers is 8:2.

[0048] Example 5: A method for preparing a hydrogel-type colored and stable facial mask base fabric comprises the following steps:

[0049] The bamboo fiber is cut and opened and mixed with the lignin-based hydrogel staple fiber prepared in Example 2 to obtain mixed staple fibers. The mixed staple fibers are then combed and laid to obtain a fiber web. The fiber web is then pre-wetted, subjected to high-pressure water entanglement, dehydrated, and dried to obtain a hydrogel-type colored and stable facial mask base fabric. The mass ratio of bamboo fiber to lignin-based hydrogel staple fibers is 7:3.

[0050] Example 6: A method for preparing a hydrogel-type colored and stable facial mask base fabric comprises the following steps:

[0051] The cut bamboo fiber is opened and mixed with the lignin-based hydrogel staple fiber prepared in Example 3 to obtain mixed staple fibers. The mixed staple fibers are then combed and laid to obtain a fiber web. The fiber web is then pre-wetted, subjected to high-pressure water entanglement, dehydrated, and dried to obtain a hydrogel-type, colored and stable facial mask base fabric. The mass ratio of bamboo fiber to lignin-based hydrogel staple fibers is 5:5.

[0052] Comparative Example 1: This comparative example is a facial mask base fabric. The difference from Example 6 is that the hydrogel short fibers A prepared in the following steps are used instead of the lignin-based hydrogel short fibers prepared in Example 3. The rest are the same.

[0053] The above-mentioned hydrogel staple fibers A were prepared by the following steps: 2 g of the silicone prepared in step A4 of Example 3, 15 g of sodium lignin sulfonate, 1 g of modified carbon black, 5 g of polyvinyl alcohol, and 300 g of water were mixed to obtain a spinning solution, which was then spun into a 35 wt% glutaraldehyde aqueous solution through a spinning machine and immersed for 2 h. After being taken out, the fibers were freeze-dried and cut to obtain lignin-based hydrogel staple fibers.

[0054] Comparative Example 2: This comparative example is a facial mask base fabric. The difference from Example 6 is that the hydrogel short fibers B prepared in the following steps are used instead of the lignin-based hydrogel short fibers prepared in Example 3. The rest are the same.

[0055] The above-mentioned hydrogel staple fibers B were prepared by the following steps: 2 g of the silicone prepared in step A4 of Example 3, 15 g of sodium disulfide lignin sulfonate prepared in step A4, 1 g of carbon black, 5 g of polyvinyl alcohol, and 300 g of water were mixed to obtain a spinning solution, which was then spun into a 35 wt% glutaraldehyde aqueous solution through a spinning machine and immersed for 2 h. After being taken out, the solution was freeze-dried and cut to obtain lignin-based hydrogel staple fibers.

[0056] Comparative Example 3: This comparative example is a facial mask base fabric. The difference from Example 6 is that the hydrogel short fibers C prepared in the following steps are used instead of the lignin-based hydrogel short fibers prepared in Example 3. The rest are the same.

[0057] The above-mentioned hydrogel staple fibers C were prepared by the following steps: 2 g of the silicone prepared in step A4 of Example 3, 15 g of sodium lignin sulfonate, 1 g of carbon black, 5 g of polyvinyl alcohol, and 300 g of water were mixed to obtain a spinning solution, which was then spun into a 35 wt% glutaraldehyde aqueous solution through a spinning machine and immersed for 2 h. After being taken out, the fibers were freeze-dried and cut to obtain lignin-based hydrogel staple fibers.

[0058] The facial mask base fabrics prepared in Examples 4-6 and Comparative Examples 1-3 were subjected to performance tests:

[0059] Liquid holding rate and liquid retention rate test: Spread a sample with a weight of m1 and immerse it in the special essence for facial mask. Allow it to fully immerse for 10 minutes. After removing the sample, hang it in the air and let it stand until no essence drips. The weight is recorded as m2. After removing the sample, hang it in the air and let it stand for 6 hours. The weight is recorded as m3. Calculate the liquid holding rate (%) = (m2-m1) / m1×100%, and the liquid retention rate (%) = (m3-m2) / (m2-m1)×100%;

[0060] Moisturizing performance test: After soaking the mask base for 10 minutes, apply it to the skin surface and use a skin tester to measure the skin moisture content at different time points;

[0061] Antioxidant performance test: The mask base fabric was immersed in a 1,1-diphenyl-2-picrylhydrazyl (DPPH) ethanol solution (0.05 mg / mL) in the dark at 37°C for 10 minutes. Pure DPPH ethanol solution was used as the control group. The absorbance of the solution at 517 nm was measured by UV spectrophotometer at the predetermined time. DPPH free radical scavenging efficiency (%) = (A1-A2) / A1×100%, where A1 is the absorbance of the DPPH ethanol solution and A2 is the absorbance of the DPPH ethanol solution after adding the mask base fabric.

[0062] Coloring stability test: refer to GB / T3920-2008 standard to test color fastness grade;

[0063] Breaking Strength Test: An electronic strength tester was used to test the breaking strength of wet samples in accordance with GB / T 2428.3-2010. The sample size was 5 cm × 30 cm (the length was greater than the clamping distance of 20 cm). The tensile speed was 100 mm / min. The samples were conditioned (wet state) according to the method of GB / T 6529-1008.

[0064] The test results are shown in Table 1:

[0065] Table 1: Performance test results

[0066]

[0067] As can be seen from Table 1, the facial mask base fabric prepared by the present invention has excellent liquid holding rate and liquid retention rate after being tested for liquid holding rate, liquid retention rate, moisturizing performance, antioxidant performance, color fastness and breaking strength. After being applied to the skin, the base fabric can make the skin have a higher water content. At the same time, it also has excellent antioxidant performance, coloring stability and breaking strength.

[0068] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the scope of protection of the present invention.

Claims

1. A hydrogel-type colored and stable facial mask base fabric, characterized in that: The fiber mesh is made by mixing lignin-based hydrogel short fibers and bamboo fibers and then undergoing hydroentanglement processing; The lignin-based hydrogel short fibers are prepared by spinning a mixture of organosilicon, sodium disulfide lignin sulfonate, modified carbon black, polyvinyl alcohol, and water; the sodium disulfide lignin sulfonate is prepared by reacting a pre-treated sodium lignin sulfonate aqueous solution with thioctic acid; the pre-treated sodium lignin sulfonate is prepared by reacting sodium lignin sulfonate, an amino-terminated product, and formaldehyde; and the amino-terminated product is prepared by esterification of diethanolamine and para-aminobenzoic acid. The organosilicon is prepared by a mixed reaction of dimethylsiloxane and methyltrimethoxysilane; The modified carbon black is prepared by reacting carbon black and chitosan; The lignin-based hydrogel short fibers are specifically prepared by the following steps: Step A1: Under nitrogen, diethanolamine, p-aminobenzoic acid, and p-toluenesulfonic acid were mixed, heated to 100°C, and stirred for 20 minutes. Cyclohexane was added, and the mixture was heated to 140°C for 1 hour. The mixture was then vacuum-dried for 2 hours and purified to obtain an amino-terminated product. Step A2, mixing sodium lignin sulfonate, amino-terminated product, sodium hydroxide and water, and heating to 85° C., adding 25-35 wt % formaldehyde aqueous solution dropwise, condensing and reflux for 3-5 hours, adding 1 mol / L hydrochloric acid until no precipitate is formed, filtering, washing, drying and grinding to obtain pretreated sodium lignin sulfonate; Step A3, mixing lipoic acid, sodium hydroxide and water and stirring for 30 minutes, adding N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide and stirring for 1-2 hours, then adding 2-4 wt% pre-treated sodium lignin sulfonate aqueous solution and ethanol, stirring vigorously for 12-16 hours, and rotary evaporation to obtain sodium lignin disulfide; Step A4, dimethylsiloxane, methyltrimethoxysilane, potassium hydroxide, water and ethanol are mixed and stirred at 50-60°C for 2-4 hours, then heated to 120°C for reaction for 30-50 minutes, cyclohexane and cation exchange resin are added, filtered and distilled, and the organosilicon is collected; the organosilicon, sodium disulfide lignin sulfonate, modified carbon black, polyvinyl alcohol and water are mixed to obtain a spinning solution, which is then spun into a 35wt% glutaraldehyde aqueous solution through a spinning machine and soaked for 2 hours. After removal, the fibers are freeze-dried and cut to obtain lignin-based hydrogel short fibers.

2. The hydrogel-type colored and stable facial mask base fabric according to claim 1, characterized in that: In step A1, the molar ratio of diethanolamine to p-aminobenzoic acid is 1:2, and the amounts of p-toluenesulfonic acid and cyclohexane are 0.5% and 50% of the total mass of diethanolamine and p-aminobenzoic acid, respectively.

3. The hydrogel-type colored and stable facial mask base fabric according to claim 1, characterized in that: In step A2, the usage ratio of sodium lignin sulfonate, amino-terminated product, sodium hydroxide, water and formaldehyde aqueous solution is 10 g: 2-4 g: 0.3-0.5 g: 50 mL: 4-6 mL.

4. The hydrogel-type colored and stable facial mask base fabric according to claim 1, characterized in that: In step A3, the ratio of lipoic acid, sodium hydroxide, water, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, pre-treated sodium lignin sulfonate aqueous solution and ethanol is 0.1-0.2 mol:4-8 g:100 mL:0.1-0.2 mol:0.05-0.1 mol:50 mL:50 mL.

5. The hydrogel-type colored and stable facial mask base fabric according to claim 1, characterized in that: In step A4, the mass ratio of organosilicon, sodium disulfide lignin sulfonate, modified carbon black, polyvinyl alcohol and water in the lignin-based hydrogel short fibers is 1-2:10-15:0.5-1:3-5:

300.

6. The hydrogel-type colored and stable facial mask base fabric according to claim 1, characterized in that: In step A4, the mass ratio of dimethylsiloxane, methyltrimethoxysilane, potassium hydroxide, water, ethanol, cyclohexane and cation exchange resin in the organosilicon is 5-10:2-4:0.01:2-3:7:30:3-6.

7. The hydrogel-type colored and stable facial mask base fabric according to claim 1, characterized in that: The modified carbon black is prepared by the following steps: mixing carbon black, buffer solution and chitosan solution, stirring for 2-3 hours, centrifuging, washing and drying to obtain the modified carbon black.

8. The hydrogel-type colored and stable facial mask base fabric according to claim 7, characterized in that: The modified carbon black comprises carbon black, buffer solution and chitosan solution in a ratio of 2-5 g:50 mL:10 g, the buffer solution is a phosphate buffer solution with a pH of 7.6, the chitosan solution is a mixture of chitosan and water in a mass ratio of 0.2-0.5:10, and the pH of the chitosan solution is 5.

9. A method for preparing the hydrogel-type colored and stable facial mask base fabric according to any one of claims 1 to 8, characterized in that: The following steps are involved: The bamboo fibers are cut and opened and mixed with lignin-based hydrogel staple fibers to obtain mixed staple fibers. The mixed staple fibers are then combed and laid to form a fiber web. The fiber web is then pre-wetted, subjected to high-pressure water entanglement, dehydrated, and dried to obtain a hydrogel-type, colored, and stable facial mask base fabric. The mass ratio of the bamboo fibers to the lignin-based hydrogel staple fibers is 5-8:2-5.

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