WO2022062830A1 - Unidirectional water-guiding facial mask base material and preparation method therefor - Google Patents

Abstract

A unidirectional water-guiding facial mask base material, having a three-layer structure. The upper layer is a hydrophobic modified polyester fiber, the middle layer is a chitosan modified polyvinyl alcohol fiber, and the lower layer is a viscose fiber. After carding and web formation of the hydrophobic modified polyester fiber, the chitosan modified polyvinyl alcohol fiber, and the viscose fiber, hydroentanglement and reinforcement is performed to obtain the present unidirectional water-guiding facial mask base material. The three fiber layers of different materials are compounded, so that the obtained mask base material is capable of unidirectional vertical water-guiding. After the mask absorbs nutritional essence, the nutritional essence may be vertically transferred in a direction from top to bottom, so that the absorption efficiency of the nutritional essence is maximized and no nutritional essence is wasted. The surface density of each fiber layer and the angle of compounding, and cooperative effects of the three fiber layers of upper, middle, and lower layer, allow the obtained facial mask base material to have excellent overall performance, unidirectional water-guiding performance, excellent water absorption and water retention performance, and good air permeability and moisture permeability, so that sufficient absorption of the nutritional essence by facial skin is ensured, and the facial mask is comfortable and soft in texture.

Description

A kind of unidirectional water-conducting mask substrate and preparation method thereof technical field

The invention belongs to the technical field of mask substrates, and in particular relates to a one-way water-conducting mask substrate and a preparation method thereof.

Background technique

With the improvement of people's living standards, women and even men pay more and more attention to skin care, and in the daily use of skin care products, facial mask products are in the forefront. There are many types of masks, which can be mainly divided into four categories according to the product form: face masks (stick-type masks), gel masks, powder masks, and cream masks. Among them, the facial mask is easy to carry, simple and quick to use, and can be stored for a long time, and has become the most popular type of facial mask among consumers. Data shows that more than 80% of the masks currently on the market are face masks, which are mainly based on non-woven base fabrics, which can improve the skin's absorption speed and absorption of nutrients in the nutrient solution.

Commercially available non-woven mask base fabrics mainly use cotton, viscose, tencel, cupro fiber and wood pulp fiber as the main raw materials, and a few products use chitin fiber and silk fiber. The production processes of the products mainly include spunlace, wet spunbond and dry papermaking. The application of non-woven materials composited by spunlace process in the field of hygiene products has been booming. Due to its low price and high yield, spunlace non-woven face masks have become the first choice for popular face masks. The development of the spunlace non-woven fabric for the mask is to maximize the effect and allow the skin to absorb the essence to the greatest extent, giving the best experience and effect. The development trend of facial masks can be summarized as: comfortable, thin, soft, easy to form, transparent and invisible, highly moisturizing, functional and non-deformation. Since the cosmetic effect of the mask is achieved by the nutrient solution carried by the film cloth, the mask base cloth is used as the carrier of the nutrient solution, and the amount of the nutrient solution carried directly affects the use effect of the mask. The base cloth holds too little liquid, and the cosmetic effect is not obvious. At the same time, due to the absorption of the skin and its own volatilization, the mask quickly dries out, causing the mask to absorb moisture from the skin, and it cannot achieve maintenance. The mask is to use the short time covered on the face to block the contact between the skin and the air, inhibit the evaporation of skin moisture, so as to maintain sufficient moisture in the facial skin; at the same time, the mask carries moisture to fully moisturize the skin stratum corneum and enhance the penetration of the stratum corneum. The nutrients in the mask can effectively penetrate into the skin and promote the metabolism of epithelial cells. Since the cosmetic effect of the mask is achieved by the nutrient solution carried by the film cloth, the mask base cloth is used as the carrier of the nutrient solution, and the amount of the nutrient solution carried directly affects the use effect of the mask. The base cloth holds too little liquid, and the cosmetic effect is not obvious. At the same time, due to the absorption of the skin and its own volatilization, the mask quickly dries out, which causes the mask to absorb moisture from the skin and does not play a role in maintenance. Therefore, while the mask material is comfortable, soft, and thin, it must also ensure high liquid holding capacity and water-locking (anti-volatile) performance.

Recently, scientists have proposed the concept of unidirectional water, which means that water flows irreversibly in a single direction when passing through a substance or material with a specific structure. This phenomenon is ubiquitous in nature, such as cell membrane fluid exchange, where plants draw water and moisture from the soil. The application of unidirectional water guide in the field of fabrics, especially the substrate of the mask, can just solve the problem of water locking and water retention of the mask. The key to the preparation of unidirectional water-conducting materials lies in the differential capillary effect and the gradient wettability of the material, which produces the differential capillary effect and forms the directional movement of water in the material without external driving force. However, the raw materials and preparation methods of some existing unidirectional water-conducting materials mostly use chemical finishing methods, such as fluorine-containing hydrophobic treatment, which is not conducive to the environment and human health, and is not suitable for the use of mask materials. There is also a plasma method modification, which avoids the use of toxic chemical finishing agents, but this method is expensive and has an obvious time limit, and the effect of one-way water guiding after treatment is short.

SUMMARY OF THE INVENTION

The invention uses hydrophobic fibers and hydrophilic fibers as raw materials, so that the difference between the hydrophilicity and hydrophobicity of the two sides of the mask substrate is large enough, and the difference in hygroscopicity between the upper and lower layers of fibers forms a differential capillary effect and realizes the directional water conduction of the material. At the same time, the material is used as a mask substrate, the viscose fiber layer is close to the skin, and the polyester fiber layer is exposed to the air, which can prevent moisture from evaporating and effectively lock in moisture. The mask substrate obtained by the invention has high water retention rate and strong shrinkage ability, and can keep the essence in the mask for more than 2 hours and the water retention rate is still more than 90%. Very good breathability. As a mask, it's comfortable and gentle without making the skin uncomfortable.

In order to solve the above-mentioned technical problems, the technical scheme of the present invention is as follows:

A unidirectional water-conducting mask substrate has a three-layer structure, the upper layer is hydrophobically modified polyester fiber, the middle layer is chitosan-modified polyvinyl alcohol fiber, and the lower layer is viscose fiber; hydrophobically modified polyester fiber, chitosan Modified polyvinyl alcohol fiber and viscose fiber are obtained by combing into a web and then spunlace reinforcement.

The compounding is a compounding of two fibers at 30-60°. The angle of compounding described here is the angle in the MD direction (machine output direction) of the two fiber webs that are compounded.

Preferably, the hydrophobically modified polyester fiber web and the chitosan-modified polyvinyl alcohol fiber web are composited at 30°±5°, and the chitosan-modified polyvinyl alcohol fiber web and viscose fiber web are at 45°±5° 5° compound. The inventor unexpectedly found that, by adopting the above-mentioned composite method, a mask substrate with vertical water conductivity and excellent water retention and air permeability can be finally obtained. The preparation of the hydrophobically modified polyester fiber includes the following steps: terephthalic acid, butanediol, and castor oil modified polyol undergo prepolymerization and polycondensation to obtain polyester; The masterbatch is obtained from the pellet; the hydrophobically modified polyester fiber is prepared by melt spinning, cooling, drawing and winding.

Further, the castor oil-modified polyol has a hydroxyl value of 50-80 mg KOH/g, an acid value of 0.1-0.6 mg KOH/g, a number-average molecular weight of 2000-5000, and a functionality of 2-3.

Further, the molar ratio of terephthalic acid, butanediol and castor oil modified polyol is 110-130:100-120:5-10; the reaction conditions in the prepolymerization stage are that the temperature is 230-250°C, and the pressure is- 0.05 to -0.1MPa, the prepolymerization time is 0.5-1h; the reaction conditions of the polycondensation stage are adding a polycondensation catalyst, the temperature is 260-275℃, the vacuum degree is 0.01-0.05Mpa, and the polycondensation time is 3-5h. The polycondensation catalyst is Sb ₂ O ₃ , and the dosage is 0.5-1.5 wt % of the total mass of the initial monomers (terephthalic acid, butanediol and castor oil-modified polyol).

The viscosity average molecular weight of the obtained polyester is 2×10 ⁵ to 3×10 ⁵ g/mol.

The mass ratio of polyester chips and polyethylene glycol is 100:5-10, and the number average molecular weight of the polyethylene glycol is 400-600. The temperature of the melt extrusion granulation is 190-230°C. Preferably, a twin-screw extruder is used, and the temperature parameters of each zone are: 190°C in the first zone, 200°C in the second zone, 210°C in the third zone, 220°C in the fourth zone, 230°C in the fifth zone, and 220°C in the sixth zone.

Preferably, various auxiliary agents, such as lubricants, antibacterial agents, and antioxidants, can also be added during extrusion granulation.

The type and addition amount of each auxiliary agent are well known in the art. Specifically, the lubricant is selected from pentaerythritol stearate and polyvinylpyrrolidone; the antibacterial agent is selected from nano silver and quaternary ammonium salt; the Antioxidants are selected from BHT1010 and 2246; the addition amount of various additives is 0.1-3% of the polyester quality.

Melt spinning process is spinning temperature 295-310℃, setting temperature 140-160℃, POY spinning speed: 2600-3000m/min, POY drafting ratio 1.5-2 times, FDY spinning speed 4200-4600m/min , FDY draft ratio is 3-3.5 times, winding speed is 3000-3300r/min.

The chitosan-modified polyvinyl alcohol fiber is obtained by the following preparation method: after the polyvinyl alcohol fiber is impregnated with an acetic acid solution of chitosan, it is obtained by drying.

Further, in the acetic acid solution of chitosan, the concentration of chitosan is 3-5wt%, the concentration of acetic acid is 5-10wt%; the immersion time is 3-5h.

The viscose fiber is preferably a strong viscose fiber, with a dry strength of 35-50 cN/tex, preferably 38-44 cN/tex.

Viscose fiber has good water absorption, hydrophilicity, and natural degradability, so it is very suitable for use as a mask material.

Preferably, in the carding step, the areal density of the hydrophobically modified polyester fibers after carding is 20-25 g/m ² , and the areal density of the chitosan-modified polyvinyl alcohol fibers after carding is 15-25 g/m 2 . 20 g/m ² , and the viscose fiber has an areal density of 10-15 g/m ² after carding. More preferably, after the three kinds of fibers are combed, the areal density decreases in the order of the hydrophobically modified polyester fiber web, the chitosan modified polyvinyl alcohol fiber web, and the viscose fiber web.

The inventors found that the three fibers are intertwined from top to bottom through spunlace reinforcement with gradually decreasing areal density, which is more conducive to the unidirectional water-conducting performance of the obtained material, while maintaining excellent air permeability.

The technological conditions of the spunlace reinforcement are that the chitosan-modified polyvinyl alcohol fiber layer is pre-wetted with a spunlace machine, and then 3-5 times of spunlace reinforcement are performed.

Preferably, the water pressure of the pre-wetted spunlace is 1.5-2.0 MPa; for the 3-5 spunlace, the water pressure is successively increased and then successively decreased. The first and last spunlace water pressure is 4.5-5MPa, and the spunlace water pressure of the middle pass is 6.5-9.5MPa. For example, if it is 3 spunlace, the first and last spunlace water pressure is 4.5-5MPa, and the second spunlace water pressure is 7.5-8MPa; if it is 5 spunlace, the first and last spunlace water pressure is 7.5-8MPa; The spunlace pressure is 4.5-5MPa, the second and fourth spunlace pressures are 6.5-7.5MPa, and the third spunlace pressure is 8.5-9.5MPa.

Further preferably, the water-stimulated water needle action distance is 12-20mm, preferably 14-16mm; the speed of the net feeding roller shutter is 50-100m/s, preferably 70-90m/s.

Spunlace reinforcement is to continuously spray the fiber web through high-pressure water flow. Under the action of hydraulic force, the fibers in each fiber layer are displaced, rearranged, and entangled with each other, so that the three-layer fiber web is combined into a whole. The spunlace process makes the mask base fabric high strength, soft to the touch, no chemical adhesive, good air permeability, and meets the requirements of use.

The invention also provides a method for preparing the unidirectional water-conducting mask base material, comprising the following steps: the hydrophobically modified polyester fiber and the viscose fiber are respectively opened, carded into a web, compounded, spunlace reinforced, dried, and curled.

Compared with the prior art, the one-way water-conducting mask substrate provided by the present invention has achieved the following beneficial effects:

1. The present invention adopts three layers of fiber layers of different materials for compounding, and the obtained mask substrate has unidirectional vertical water conductivity, so that after the mask absorbs the nutrient essence, it can vertically transmit the nutrient essence from top to bottom in a directional direction, so that the Maximize the efficiency of absorbing nutrient solution without wasting nutrient solution.

2. In the mask substrate of the three-layer composite structure of the present invention, the materials of the three layers play a synergistic role; the modified polyester fiber layer of the uppermost layer can fully lock the moisture and reduce volatilization and loss; the chitosan treatment of the middle layer The back polyvinyl alcohol fiber layer has good water absorption and large liquid holding capacity; the bottom layer of viscose fiber has a comfortable and soft touch with the skin. Selecting the appropriate spunlace reinforcement process, the surface density of each fiber layer and the angle of compounding, and the synergistic effect of the upper, middle and lower fiber layers, make the obtained mask substrate excellent in comprehensive performance, unidirectional water conductivity, and good Breathability, moisture permeability, water absorption and water retention. It ensures that the facial skin can fully absorb the nutrient solution, while the texture of the mask is comfortable and soft.

detailed description

Chitosan was purchased from Shandong Aokang Biotechnology Co., Ltd., with a molecular weight of 70 kDa and a degree of deacetylation of 75%.

The polyvinyl alcohol fiber was purchased from Taian Tonghong Fiber Co., Ltd., the fineness was 2.3dtex, the strength was 13.5cN/dtex, and the specific gravity was 1.29g/cm ³ .

The viscose fiber was purchased from Quanzhou Haitian Light Textile Co., Ltd., and the strength was 26.5cN/dtex.

The castor oil-modified polyol was purchased from Vantruth, the grade D2000, the molecular weight was 2000, the hydroxyl value was 56 mg KOH/g, the acid value was 0.3 mg KOH/g, and the functionality was 3.

Preparation Example 1

Add terephthalic acid, butanediol and castor oil modified polyol to the reaction kettle. The molar ratio of terephthalic acid, butanediol and castor oil modified polyol is 120:100:10. , the relative pressure is -0.05MPa and pre-polymerized for 1h; then add monomer (the sum of terephthalic acid, butanediol, castor oil modified polyol) 1wt% polycondensation catalyst Sb ₂ O ₃ , at 270 ℃, 0.01 MPa polycondensation for 5h, the acid value of the detection system was lower than 10mg KOH/g, the reaction was stopped, the impurities were removed by filtration, and the polyester was sliced with a dicing knife through a cast belt. The viscosity average molecular weight of the obtained polyester was measured to be 23400g/mol.

The obtained 100 parts of polyester chips and 7 parts of PEG600, 0.5 parts of nano silver, 1.1 parts of pentaerythritol stearate, 0.8 parts of antioxidant 2246 were added to a twin-screw extruder for extrusion granulation, and the twin-screw extruder process The temperature parameters of each zone are: 190°C in the first zone, 200°C in the second zone, 210°C in the third zone, 220°C in the fourth zone, 230°C in the fifth zone, and 220°C in the sixth zone, and the speed is 260r/min.

The obtained modified polyester masterbatch is melt-spun, cooled, drawn and wound to prepare hydrophobically modified polyester fibers. The melt spinning process is spinning temperature of 300°C, setting temperature of 150°C, POY spinning speed: 2600m/min, POY drafting multiple is 2 times, FDY spinning speed is 4200m/min, FDY drafting multiple is 3 times, roll Winding speed 3000r/min.

Preparation Example 2

Other conditions and steps are the same as in Preparation Example 1, except that the castor oil-modified polyol has a molar ratio of terephthalic acid, butanediol, and castor oil-modified polyol of 120:100:5.

Preparation Example 3

Other conditions and steps are the same as in Preparation Example 1, except that after the polyvinyl alcohol fibers are soaked in acetic acid solution of chitosan for 4 hours, the concentration of chitosan is 3wt% and the concentration of acetic acid is 6wt%. Polyvinyl alcohol fiber.

Comparative Preparation Example 1

Other conditions and steps are the same as in Preparation Example 1, except that no castor oil-modified polyol is added.

Example 1

The hydrophobically modified polyester fibers obtained in Preparation Example 1, the chitosan-modified polyvinyl alcohol fibers and viscose fibers obtained in Preparation Example 3 were respectively opened and carded into a web. The injection amount is controlled so that the surface density of the hydrophobically modified polyester fiber mesh is 20 g/m ² , the surface density of the chitosan modified polyvinyl alcohol fiber after carding is 15 g/m ² , and the surface density of the viscose fiber after carding is 10g/m ² . The hydrophobically modified polyester fiber web, the chitosan-modified polyvinyl alcohol fiber web and the viscose fiber web are compounded in the order from top to bottom, wherein the hydrophobically modified polyester fiber web and the chitosan-modified polyvinyl alcohol are The fiber web is compounded at 30°, the chitosan-modified polyvinyl alcohol fiber web and the viscose fiber web are compounded at 45°, and spunlace reinforcement is performed after compounding. The spunlace reinforcement process is: first pre-wet the chitosan-modified polyvinyl alcohol fiber layer, and the spunlace water pressure is 1.5MPa; The pressure of the second spunlace water is 7.5MPa, and the pressure of the third spunlace water is 4.5MPa. The water-stimulated water-needle action distance is 14mm; the speed of the rolling shutter is 180m/s. After spunlace reinforcement, drying is carried out, and the unidirectional water-conducting mask substrate is obtained by curling.

Example 2

Other steps and conditions are the same as in Example 1, except that the hydrophobically modified polyester fiber of Preparation Example 1 is replaced by the hydrophobic polyester fiber prepared in Preparation Example 2.

Example 3

Other steps and conditions are the same as in Example 1, the difference is that the injection amount is controlled so that the surface density of the hydrophobically modified polyester fiber mesh is 15g/m ² , and the surface density of the chitosan modified polyvinyl alcohol fiber after carding is 15g/m2 ^2. After the viscose fiber is combed, the areal density is 15g/m ² .

Example 4

The other steps and conditions are the same as in Example 1, except that the hydrophobically modified polyester fiber web and the chitosan-modified polyvinyl alcohol fiber web, the chitosan-modified polyvinyl alcohol fiber web and the viscose fiber web are both. 30° compound.

Example 5

The other steps and conditions are the same as in Example 1, except that the hydrophobically modified polyester fiber web and the chitosan-modified polyvinyl alcohol fiber web, the chitosan-modified polyvinyl alcohol fiber web and the viscose fiber web are both. 45° compound.

Comparative Example 1

Other steps and conditions are the same as in Example 1, except that the hydrophobically modified polyester fiber of Preparation Example 1 is replaced by the polybutylene terephthalate (PBT) fiber prepared in Comparative Preparation Example 1.

Comparative Example 2

Other steps and conditions are the same as in Example 1, except that the chitosan-modified polyvinyl alcohol fibers obtained in Preparation Example 3 are replaced with ordinary polyvinyl alcohol fibers that have not been treated with chitosan acetic acid solution.

Application example 1 Mechanical property test of mask substrate

Referring to Part 3 of GB/T24218.3-2010, YG028-500 tensile tester was used to test the breaking strength and breaking elongation of the mask substrate in dry and wet states. The size of the mask substrate was cut to 50mm×200mm, the clamping distance was set to 100mm, the stretching speed was 100mm/min, and the stretching experiment was carried out in a constant speed stretching method.

The mechanical properties test in the wet state is to soak the mask substrate in distilled water for 10 minutes, then take it out and test its mechanical properties immediately. Dry and wet mask substrates were tested 10 times for each group of samples, and the data were averaged. The results are shown in Table 1 below:

Table 1

Application example 2 Evaluation of water absorption and water retention

With reference to GB/T24218.6-2010 Absorbency Measurement, the water absorption and water retention of the mask substrate of the embodiment of the present invention were tested. The mask substrate is cut to 10cm×10cm.

The water absorption is expressed by the liquid absorption S (g/g), S ₀ =(m ₁ -m ₀ )/m ₀ , where m ₁ means that the mask substrate is immersed in distilled water for 10 minutes and then taken out, and placed vertically on the metal copper mesh Hang the sample and let it stand for 1 min to drain the excess water. The mass of the mask substrate is m ₀ represents the mass of the mask substrate before immersion in water, and S ₀ represents the maximum amount of water that the mask substrate can absorb per unit mass. The liquid absorption of the mask substrate is an important indicator for the consideration of the mask material, which directly affects the amount of essence absorbed by the mask and is an important guarantee for the skin to absorb nutrients.

The water retention is measured at an ambient temperature of 25°C, a relative humidity of 60%, and a standard atmospheric pressure environment. After a period of time, the liquid absorption amount S _t of the mask substrate is tested, (S _t =(m _t -m ₀ )/m ₀ , m _t represents the quality of the mask substrate at time t), which is calculated as S _t /S ₀ , which represents the retention rate of water absorption over time. The higher the percentage value, the better the water retention. Water retention is an important indicator for the consideration of mask materials. When people use a mask, they generally keep it on the face for more than half an hour. If the water is lost quickly, the effectiveness of the mask will be greatly reduced. Therefore, excellent water absorption and water retention are the properties required for mask materials. The mask material obtained by the present invention has excellent water absorption and water retention simultaneously, and the results are shown in Table 2 below:

Table 2

Application example 3 Evaluation of air permeability and moisture permeability

Referring to GB/T24218-2018- Nonwovens Air Permeability Test Standard, use YG461E automatic fabric air permeability tester to test the air permeability of the film substrate in dry state; refer to YY/T0471.2, use W3/060 water vapor transmission The rate test system is used to test the water vapor passing rate. The test conditions are set to 36°C and the relative humidity is 90RH%. The results are shown in Table 3 below:

table 3

Good breathability is an indicator of mask comfort. The cells of the basal layer of the skin need to absorb oxygen for metabolism, and a good breathable mask base cloth can keep the skin in normal contact with oxygen. When people use the mask, the mask with the essence is applied on the face for a period of time, and the essence of the mask will gradually evaporate over time while being absorbed by the skin. The evaporation of the liquid allows the mask essence to stay on the face for a longer time and play a greater role. However, the mask substrate also needs a certain moisture permeability to make the user feel comfortable. Air and moisture permeability depend on the number of voids between fibers, the nature and structure of the fibers. In the present invention, suitable fiber materials are selected, and a composite mask substrate with a three-layer structure is prepared according to a specific process. The mask substrate has unidirectional water conductivity, excellent water absorption and water retention properties, and at the same time good air permeability and suitable moisture permeability, which ensures the comfort and function of the mask substrate as a mask base cloth to the skin.

Application Example 4 Evaluation of Softness and Comfort

Since the human face is uneven and three-dimensional, the mask substrate needs to have lower bending performance and better softness, so that the mask can fit closely with the human face in the wet state, and the comfort of the human body also needs to be considered. . The test of bending rigidity is carried out to the mask base material obtained in the embodiment of the present invention, and the results are shown in Table 4 below:

Table 4

As can be seen from the data in Table 4, the bending stiffness of the mask substrate prepared in the embodiment of the present invention is much lower than that in the dry state, indicating that the mask substrate provided by the present invention can maintain the stiffness in the dry state, and in the wet state It can fully fit the human face, soft and comfortable.

Claims (10)

A unidirectional water-conducting mask substrate has a three-layer structure, the upper layer is hydrophobically modified polyester fiber, the middle layer is chitosan-modified polyvinyl alcohol fiber, and the lower layer is viscose fiber; hydrophobically modified polyester fiber, chitosan Modified polyvinyl alcohol fiber and viscose fiber are obtained by combing into a web and then spunlace reinforcement. The mask substrate according to claim 1, wherein the compounding is a compounding of two fibers at 30-60°. The mask substrate according to claim 2, wherein the hydrophobically modified polyester fiber web and the chitosan-modified polyvinyl alcohol fiber web are composited at 30°±5°, and the chitosan modified The polyvinyl alcohol fiber web and viscose fiber web are compounded at 45°±5°. The mask substrate according to claim 1, wherein the preparation of the hydrophobically modified polyester fiber comprises the following steps: prepolymerization of terephthalic acid, butanediol, and castor oil modified polyol, and polycondensation to obtain a polymer Ester; polyester and polyethylene glycol are melted and extruded to obtain masterbatch; hydrophobically modified polyester fiber is prepared by melt spinning, cooling, drawing and winding. The mask substrate according to claim 4, wherein the castor oil-modified polyol has a hydroxyl value of 50-80 mg KOH/g, an acid value of 0.1-0.6 mg KOH/g, and a number-average molecular weight of 2000 -5000, functionality 2-3; and/or The molar ratio of terephthalic acid, butanediol and castor oil modified polyol is 110-130:100-120:5-10. The mask substrate according to claim 4, wherein the mass ratio of polyester chips and polyethylene glycol is 100:5-10, and the number average molecular weight of the polyethylene glycol is 400-600. The mask substrate according to claim 1, wherein the chitosan-modified polyvinyl alcohol fiber is obtained by the following preparation method: after immersing the polyvinyl alcohol fiber with an acetic acid solution of chitosan, drying to Preferably, in the acetic acid solution of chitosan, the concentration of chitosan is 3-5wt%, the concentration of acetic acid is 5-10wt%; the immersion time is 3-5h. The mask substrate according to claim 1, wherein in the carding step, the hydrophobically modified polyester fibers have an area density of 20-25 g/m ² after carding, and the chitosan modified polyester fibers have an area density of 20-25 g/m 2 The areal density of the polyvinyl alcohol fibers after carding is 15-20 g/m ² , and the areal density of the viscose fibers after carding is 10-15 g/m ² ; Polyester fiber net, chitosan modified polyvinyl alcohol fiber net, viscose fiber net in descending order. The mask substrate according to claim 1, characterized in that, the process condition of the hydroentanglement reinforcement is to pre-wet the chitosan-modified polyvinyl alcohol fiber layer with a hydroentanglement machine, and then carry out 3-5 water injections. thorn reinforcement; Preferably, the pre-wet spunlace water pressure is 1.5-2.0MPa; the 3-5 spunlace, the water pressure is successively increased, and then successively decreased; the first and last spunlace water pressure is 4.5- 5MPa, the spunlace water pressure in the middle channel is 6.5-9.5MPa; further preferably, the water-stimulated water needle action distance is 12-20mm, preferably 14-16mm; is 70-90m/s. The preparation method of the unidirectional water-conducting mask substrate according to any one of claims 1-9, comprising the following steps: the hydrophobically modified polyester fiber and the viscose fiber are respectively opened, carded into a web, compounded, spunlace reinforced, and dried. , resulting from curling.