Antibacterial breathable fabric and preparation process thereof

Abstract

The invention belongs to the technical field of fabrics, and discloses an antibacterial breathable fabric and a preparation process thereof; 3-chloro-2-hydroxypropionic acid; a blocked polyether polyurethane and 5-nitroisophenylene (N-dimethylaminoethylformamide) undergo quaternization polymerization reaction, and finally the nitro group is reduced by sodium dithionite to obtain a novel amino quaternary ammonium salt polyurethane finishing agent. The amino quaternary ammonium salt polyurethane finishing agent contains a large number of amino groups, which can react with the aldehyde group of the oxidized cotton fabric to produce a Schiff base reaction, so that the quaternary ammonium salt polyurethane finishing agent is chemically grafted to the surface of the cotton fabric, so that the cotton fabric maintains excellent hydrophilic moisture permeability; the amino quaternary ammonium salt polyurethane finishing agent contains a large number of quaternary ammonium salt antibacterial groups in the main chain, and the cotton fabric exhibits strong bactericidal performance after finishing. After washing, the quaternary ammonium salt polyurethane finishing layer is not easy to fall off, and still maintains excellent bactericidal effect.

Description

Technical Field

[0001] The invention belongs to the technical field of fabrics, and specifically relates to an antibacterial breathable fabric and a preparation process thereof. Background Art

[0002] Cotton fabrics have good moisture absorption, air permeability and warmth retention, and are widely used in home products such as clothing fabrics, curtains, and quilt covers. However, cotton fabrics do not have antibacterial properties and are prone to breed bacteria, which has a great impact on human health and safety, and the feel of cotton fabrics is not good. Blending cotton fibers with chemical fibers can improve the feel and wrinkle resistance of cotton fabrics. Using finishing agents to finish cotton fabrics is also an effective way to improve the wrinkle resistance and antibacterial properties of cotton fabrics.

[0003] At present, the main fabric finishing agents include polyether finishing agents, silicone finishing agents, polyurethane finishing agents, etc. Cotton fabrics themselves have strong hydrophilicity and breathability. After finishing cotton fabrics with finishing agents, their hydrophilicity, moisture permeability, breathability and other properties will be affected. Polyurethane finishing agents have good elasticity and good wrinkle resistance, and the hydrophilicity of urethane finishing agents can be effectively improved by controlling the introduction of hydrophilic polyether, carboxyl and other groups into polyurethane finishing agents. However, traditional polyurethane finishing agents do not have antibacterial properties, and after finishing cotton fabrics, the finishing agents will fall off after multiple washings. Summary of the invention

[0004] The technical problem solved by the invention is to provide an antibacterial and breathable fabric and a preparation process thereof, thereby solving the problem that the cotton fabric has a poor hand feel and is not antibacterial.

[0005] Technical solution: an antibacterial breathable fabric and its preparation process:

[0006] S1. Add 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane and 5-nitroisophenylene (N-dimethylaminoethylformamide) in a mass ratio of 100:(14-16) to N,N-dimethylformamide, heat to 100-140°C, and carry out quaternization reaction for 36-72 hours. After the reaction, distill under reduced pressure, wash with ethanol, and dry to obtain nitroquaternary ammonium salt polyurethane.

[0007] S2. Add nitro quaternary ammonium salt polyurethane and sodium dithionite to a 10-13% by mass potassium hydroxide aqueous solution to carry out a reduction reaction. Freeze-dry the solution in a freeze dryer at -50°C, wash with ethanol, and dry to obtain an amino quaternary ammonium salt polyurethane finishing agent.

[0008] S3. Add cotton fabric to an aqueous solution of sodium periodate and oxidize it in the dark to obtain oxidized cotton fabric; then add the oxidized cotton fabric to an aqueous solution of an amino quaternary ammonium salt polyurethane finishing agent with a mass concentration of 20-60 g / L, perform a finishing reaction, filter, wash, and dry to obtain an antibacterial and breathable fabric.

[0009] Preferably, in S2, the mass ratio of quaternary ammonium nitropolyurethane to sodium dithionite is 100:(120-135).

[0010] Preferably, in S2, the reduction reaction temperature is 70-80°C and the time is 3-4h.

[0011] Preferably, in S3, the finishing reaction temperature is 50-65° C. and the time is 1-2 h.

[0012] Preferably, in S1, the preparation process of 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane is as follows: dry polyethylene glycol 2000 and isophorone diisocyanate are mixed, reacted at 70-75° C. for 1.5-2 hours to obtain an isocyanate-terminated polyurethane prepolymer; then 3-chloro-2-hydroxypropionic acid is added, and the molar ratio of polyethylene glycol 2000, isophorone diisocyanate, and 3-chloro-2-hydroxypropionic acid is controlled to be 1: (2.2-2.4): (2.6-3); reacted for 30-40 minutes, cooled, and obtained 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane.

[0013] Preferably, in S1, the preparation process of 5-nitroisophthaloyl di(N-dimethylaminoethylformamide) is: adding 5-nitroisophthaloyl chloride, N,N-dimethylethylenediamine and triethylamine in a molar ratio of 1:(2-2.2):(2-2.2) to dichloromethane, reacting at room temperature for 4-6 hours, distilling under reduced pressure, washing with water, and then recrystallizing from dichloromethane to obtain 5-nitroisophthaloyl di(N-dimethylaminoethylformamide).

[0014] The present invention also provides an antibacterial breathable fabric, which is prepared by the above-mentioned preparation process.

[0015] The technical effect is as follows: the present invention reacts polyethylene glycol and isophorone diisocyanate to obtain an isocyanate-terminated polyurethane prepolymer; then, 3-chloro-2-hydroxypropionic acid is used for end-capping to obtain a 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane, which contains chlorine atoms at both ends, and undergoes a quaternization polymerization reaction with 5-nitroisophenylene (N-dimethylaminoethylformamide) containing two tertiary amine groups; finally, the nitro group is reduced with sodium dithionite to obtain a novel amino quaternary ammonium salt polyurethane finishing agent.

[0016] The amino quaternary ammonium salt polyurethane finishing agent of the present invention contains a large number of amino groups, which can react with the aldehyde group of the oxidized cotton fabric to produce a Schiff base reaction, thereby chemically grafting the quaternary ammonium salt polyurethane finishing agent to the surface of the cotton fabric. The polyurethane finishing agent contains a hydrophilic polyether main chain, and the side chain contains a large number of carboxyl groups and amino hydrophilic groups. The main chain contains a quaternary ammonium salt hydrophilic group, which is grafted to the surface of the cotton fabric to form a hydrophilic finishing layer, so that the cotton fabric maintains excellent hydrophilic moisture permeability. In addition, the quaternary ammonium salt polyurethane finishing agent is firmly grafted to the surface of the cotton fabric through a chemical covalent bond, and after multiple washings, the hydrophilic finishing layer is difficult to fall off, and the fabric still has good hydrophilic moisture permeability.

[0017] When cotton fabrics are treated with amino quaternary ammonium salt polyurethane finishing agent, the air permeability of cotton fabrics is not much different from that of untreated cotton fabrics, and good air permeability and breathability are still maintained. At the same time, the hand feel of cotton fabrics is significantly improved after being treated with polyurethane finishing agent.

[0018] The amino quaternary ammonium salt polyurethane finishing agent of the present invention contains a large amount of quaternary ammonium salt antibacterial groups in the main chain, has strong positive charge, can change the permeability of bacterial cell membrane, and plays the role of inhibiting and killing bacteria. After the cotton fabric is finished, it shows strong bactericidal performance to Escherichia coli and Staphylococcus aureus, and the amino quaternary ammonium salt polyurethane finishing agent is firmly grafted on the fabric surface through chemical covalent bonds. After washing, the quaternary ammonium salt polyurethane finishing layer is not easy to fall off, the antibacterial rate decreases very little, and still maintains excellent bactericidal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the reaction formula for preparing 3-chloro-2-hydroxypropionic acid terminated polyether polyurethane.

[0020] Figure 2 This is the reaction formula for the preparation of 5-nitroisophenylene (N-dimethylaminoethylformamide).

[0021] Figure 3 It is the preparation reaction formula of amino quaternary ammonium salt polyurethane finishing agent. DETAILED DESCRIPTION

[0022] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0023] Example 1

[0024] (1): Mix 20 mmol of dry polyethylene glycol 2000 and 24 mmol of isophorone diisocyanate, and react at 75°C for 2 hours to obtain an isocyanate-terminated polyurethane prepolymer; then add 52 mmol of 3-chloro-2-hydroxypropionic acid (CAS registration number: 1713-85-5), react for 30 minutes, and cool to obtain a 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane.

[0025] (2): Add 7 mmol 5-nitroisophthaloyl chloride (CAS registration number 13438-30-7), 15.4 mmol N,N-dimethylethylenediamine (CAS registration number 108-00-9), and 15.4 mmol triethylamine to 20 mL of dichloromethane, react at room temperature for 4 h, distill under reduced pressure, wash with water, and then recrystallize from dichloromethane to obtain 5-nitroisophthaloyl (N-dimethylaminoethylformamide).

[0026] (3): Add 10 g of 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane and 1.4 g of 5-nitroisophenylene (N-dimethylaminoethylformamide) to 150 mL of N,N-dimethylformamide, heat to 100 °C, and carry out quaternization reaction for 72 hours. After the reaction, distill under reduced pressure, wash with ethanol, and dry to obtain nitroquaternary ammonium salt polyurethane.

[0027] (4): Add 20 g of nitro quaternary ammonium salt polyurethane and 27 g of sodium dithionite to 600 mL of 12% potassium hydroxide aqueous solution, heat to 80°C, and carry out reduction reaction for 3 hours. Freeze-dry the solution in a freeze dryer at -50°C, wash with ethanol, and dry to obtain an amino quaternary ammonium salt polyurethane finishing agent.

[0028] (5): Add cotton fabric to an aqueous solution of sodium periodate with a mass fraction of 1.5%, heat to 35°C, and oxidize for 40 minutes in a dark environment to obtain oxidized cotton fabric; then add the oxidized cotton fabric to an aqueous solution of amino quaternary ammonium salt polyurethane finishing agent with a mass concentration of 20 g / L, heat to 50°C, and perform finishing reaction for 2 hours, filter, wash with water, and dry to obtain an antibacterial and breathable fabric.

[0029] Example 2

[0030] (1): Mix 20 mmol of dry polyethylene glycol 2000 and 28 mmol of isophorone diisocyanate, react at 70°C for 1.5 h, then add 60 mmol of 3-chloro-2-hydroxypropionic acid, react for 40 min, and cool to obtain 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane.

[0031] (2): Add 7 mmol 5-nitroisophthaloyl chloride, 14 mmol N,N-dimethylethylenediamine, and 14 mmol triethylamine to 20 mL dichloromethane, react at room temperature for 6 h, distill under reduced pressure, wash with water, and then recrystallize from dichloromethane to obtain 5-nitroisophthaloyl (N-dimethylaminoethylformamide).

[0032] (3): Add 10 g of 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane and 1.6 g of 5-nitroisophenylene (N-dimethylaminoethylformamide) to 200 mL of N,N-dimethylformamide, heat to 110°C, and carry out quaternization reaction for 72 hours. After the reaction, distill under reduced pressure, wash with ethanol, and dry to obtain nitroquaternary ammonium salt polyurethane.

[0033] (4): Add 20 g of nitro quaternary ammonium salt polyurethane and 26 g of sodium dithionite to 800 mL of 10% by mass potassium hydroxide aqueous solution, heat to 70°C, and carry out reduction reaction for 4 hours. Freeze-dry the solution in a freeze dryer at -50°C, wash with ethanol, and dry to obtain an amino quaternary ammonium salt polyurethane finishing agent.

[0034] (5): Add the oxidized cotton fabric (prepared by the same process as in Example 1) into an aqueous solution of an amino quaternary ammonium salt polyurethane finishing agent at a mass concentration of 40 g / L, heat to 60°C, perform the finishing reaction for 1 hour, filter, wash with water, and dry to obtain an antibacterial and breathable fabric.

[0035] Example 3

[0036] (1): 10 g of 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane (prepared in the same manner as in Example 1) and 1.6 g of 5-nitroisophenylene (N-dimethylaminoethylformamide) (prepared in the same manner as in Example 1) were added to 200 mL of N,N-dimethylformamide, heated to 140° C., and subjected to quaternization reaction for 36 h. After the reaction, the mixture was distilled under reduced pressure, washed with ethanol, and dried to obtain nitroquaternary ammonium salt polyurethane.

[0037] (2): Add 20 g of nitro quaternary ammonium salt polyurethane and 24 g of sodium dithionite to 600 mL of 13% potassium hydroxide aqueous solution, heat to 75 °C, and carry out reduction reaction for 4 h. Freeze-dry the solution in a freeze dryer at -50 °C, wash with ethanol, and dry to obtain an amino quaternary ammonium salt polyurethane finishing agent.

[0038] (3): Add the oxidized cotton fabric (prepared by the same process as in Example 1) into an aqueous solution of an amino quaternary ammonium salt polyurethane finishing agent at a mass concentration of 60 g / L, heat to 65°C, perform the finishing reaction for 1 hour, filter, wash with water, and dry to obtain an antibacterial and breathable fabric.

[0039] Comparative Example 1: Unfinished cotton fabric.

[0040] Comparative Example 2

[0041] (1): Add oxidized cotton fabric (prepared by the same process as in Example 1) into an aqueous solution of nitroquaternary ammonium salt polyurethane (prepared by the same process as in Example 1) with a mass concentration of 20 g / L, heat to 50°C, perform finishing reaction for 2 hours, filter, wash with water, and dry to obtain cotton fabric.

[0042] Comparative Example 3

[0043] (1): Mix 20 mmol of dry polyethylene glycol 2000 and 24 mmol of isophorone diisocyanate, react at 75°C for 2 hours, then add 52 mmol of glycolic acid (CAS registration number 79-14-1), react for 30 minutes, and cool to obtain glycolic acid-terminated polyether polyurethane.

[0044] (2): Add oxidized cotton fabric (prepared by the same process as in Example 1) into an aqueous solution of glycolic acid-terminated polyether polyurethane at a mass concentration of 20 g / L, heat to 50°C, perform finishing reaction for 2 h, filter, wash with water, and dry to obtain an antibacterial and breathable fabric.

[0045] Comparative Example 4

[0046] (1): Mix 20 mmol of dry polyethylene glycol 2000 and 24 mmol of isophorone diisocyanate, react at 75°C for 2 hours, then add 52 mmol of 3-chloro-1-propanol (CAS registration number 627-30-5), react for 30 minutes, and cool to obtain a chloropropanol-terminated polyether polyurethane.

[0047] (2): Add 10 g of chloropropanol-terminated polyether polyurethane and 1.4 g of 5-nitroisophenylene (N-dimethylaminoethylformamide) (the same preparation process as in Example 1) to 150 mL of N,N-dimethylformamide, heat to 100° C., and carry out quaternization reaction for 72 hours. After the reaction, distill under reduced pressure, wash with ethanol, and dry to obtain nitroquaternary ammonium salt polyurethane.

[0048] (3): Add 20 g of nitro quaternary ammonium salt polyurethane and 27 g of sodium dithionite to 600 mL of 12% potassium hydroxide aqueous solution, heat to 80°C, and carry out reduction reaction for 3 hours. Freeze-dry the solution in a freeze dryer at -50°C, wash with ethanol, and dry to obtain an amino quaternary ammonium salt polyurethane finishing agent.

[0049] (4): Add the oxidized cotton fabric (prepared by the same process as in Example 1) into an aqueous solution of an amino quaternary ammonium salt polyurethane finishing agent at a mass concentration of 20 g / L, heat to 50°C, perform finishing reaction for 2 hours, filter, wash with water, and dry to obtain an antibacterial and breathable fabric.

[0050] The droplet diffusion time of the fabric is tested according to the GB / T 21655.1-2023 method. The time required for the water droplet to contact the fabric and completely diffuse and penetrate into the fabric is measured. The shorter the droplet diffusion time, the better the hydrophilicity and moisture permeability.

[0051] Wash and dry the fabric according to GB / T 8629-2017 method, repeat 30 times, and then test the water diffusion time and air permeability.

[0052] Test the air permeability of fabrics according to GB / T 5453-1997. The greater the air permeability, the better the air permeability.

[0053] The fabric feel was evaluated by 10 experienced fabric industry practitioners, who conducted a comprehensive evaluation of the fabric feel in terms of smoothness and softness. The best feel was scored as 10 points, the worst as 1 point, and the average value was taken.

[0054] Table 1 Fabric hydrophilicity, breathability and feel test

[0055]

[0056] After testing, comparative example 1 is an unfinished cotton fabric. The water diffusion time before and after washing is ≤ 1s, the hydrophilicity is very good, and the air permeability reaches 421.6 mL·cm -2 ·s -1 , excellent air permeability.

[0057] The amino quaternary ammonium salt polyurethane finishing agent prepared in Example 1-3 contains a large number of amino groups, which can react with the aldehyde group of the oxidized cotton fabric to produce a Schiff base reaction, thereby chemically grafting the quaternary ammonium salt polyurethane finishing agent to the surface of the cotton fabric. The polyurethane finishing agent contains a hydrophilic polyether main chain, and the side chain contains a large number of carboxyl and amino hydrophilic groups. The main chain contains a quaternary ammonium salt hydrophilic group, which is grafted to the surface of the cotton fabric to form a hydrophilic finishing layer, and the drip diffusion time is ≦1s, and the hydrophilic moisture permeability is also very good. In addition, the quaternary ammonium salt polyurethane finishing agent is firmly grafted on the surface of the cotton fabric through chemical covalent bonds. After multiple washings, the hydrophilic finishing layer is difficult to fall off, and the drip diffusion time is still ≦1s, maintaining good hydrophilic moisture permeability. And the air permeability of the cotton fabric after finishing reaches 407.4-416.3 mL·cm -2 ·s -1The air permeability of the cotton fabric is not much different from that of the unfinished cotton fabric, and it still maintains good air permeability and breathability after finishing. At the same time, the cotton fabric has a significantly improved feel after being finished with a polyurethane finishing agent.

[0058] In Comparative Example 2, cotton fabric is finished with quaternary ammonium nitrate polyurethane, which does not contain hydrophilic amino groups and cannot react with the aldehyde groups of oxidized cotton fabric. The polyurethane is not grafted on the fabric surface through chemical covalent bonds. After washing, the quaternary ammonium nitrate polyurethane is easily eluted, and the obtained fabric is still an unfinished and modified cotton fabric.

[0059] Comparative Example 3 uses glycolic acid to terminate polyurethane. The obtained glycolic acid terminated polyether polyurethane does not contain chlorine atoms and cannot react with quaternization. The obtained polyurethane does not contain quaternary ammonium salts and amino hydrophilic groups. After finishing the cotton fabric, the drip diffusion time is 5.5s, which affects the hydrophilic moisture permeability of the cotton fabric. However, after washing, the drip diffusion time has a downward trend and the hydrophilicity increases. This is because the glycolic acid terminated polyether polyurethane does not contain amino groups and cannot react with the aldehyde group of the oxidized cotton fabric. The polyurethane is not firmly grafted on the fabric surface through chemical covalent bonds, resulting in the polyurethane finishing layer easily falling off after washing. Since the cotton fabric itself has good hydrophilicity, the drip diffusion time is reduced.

[0060] Comparative Example 4 uses 2-chloroethanol to end-cap polyurethane, and the obtained amino quaternary ammonium salt polyurethane finishing agent does not contain a carboxyl hydrophilic group. After finishing the cotton fabric, the drip diffusion time is 4.8s, which affects the hydrophilic moisture permeability of the cotton fabric. After washing, the drip diffusion time is almost unchanged, mainly because the amino quaternary ammonium salt polyurethane finishing agent contains an amino group, which can react with the aldehyde group of the oxidized cotton fabric, thereby firmly grafting the polyurethane on the fabric surface through a chemical covalent bond. After washing, the polyurethane finishing layer is not easy to fall off, and the drip diffusion time is not affected.

[0061] Antibacterial performance test: The antibacterial performance of the fabric was tested according to the GB / T 20944.3-2008 oscillation method. The test bacteria were Escherichia coli and Staphylococcus aureus. The culture medium was beef extract peptone agar medium. The oscillation contact time between the fabric sample and the test bacterial suspension was 18 hours. The bacterial solution after oscillation contact was cultured at 37°C for 24 hours. After culture, the concentration of live bacteria was determined and the inhibition rate Y was calculated. Each group of samples was tested three times and the average value was taken.

[0062] The antibacterial rate Y = (WQ) / W × 100%, W is the viable bacteria concentration (cfu / mL) of the control sample (using comparative example 1 as the control sample) after oscillation contact. Q is the viable bacteria concentration (cfu / mL) of the experimental group sample after oscillation contact.

[0063] The fabrics were washed 30 times and then tested for their antimicrobial properties.

[0064]

[0065] After testing, the cotton fabrics of Examples 1-3 and Comparative Example 4, after being finished with amino quaternary ammonium salt polyurethane finishing agent, showed strong bactericidal properties against Escherichia coli and Staphylococcus aureus. This is because the main chain of the polyurethane finishing agent contains a large number of quaternary ammonium salt antibacterial groups, which have strong positive charge and can change the permeability of bacterial cell membranes, thereby inhibiting and killing bacteria. And after washing, the antibacterial rate decreases very little, and still maintains an excellent bactericidal effect. This is because the amino quaternary ammonium salt polyurethane finishing agent contains amino groups, which can react with the aldehyde group of the oxidized cotton fabric, thereby firmly grafting the quaternary ammonium salt polyurethane finishing agent on the fabric surface through chemical covalent bonds. After washing, the quaternary ammonium salt polyurethane finishing layer is not easy to fall off, and its antibacterial properties are not affected.

[0066] The fabric of Comparative Example 2 is an unfinished and modified cotton fabric and has no antibacterial properties.

[0067] The glycolic acid-terminated polyether polyurethane of Comparative Example 3 does not contain quaternary ammonium salt antibacterial groups and cannot effectively improve the antibacterial rate and antibacterial properties of cotton fabrics.

[0068] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A preparation process of an antibacterial breathable fabric, characterized in that: The preparation process is: S1, adding 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane and 5-nitroisophenylene (N-dimethylaminoethylformamide) to N,N-dimethylformamide, carrying out quaternization reaction, vacuum distillation, washing, and drying to obtain nitroquaternary ammonium salt polyurethane; S2, adding nitro quaternary ammonium salt polyurethane and sodium dithionite to a potassium hydroxide aqueous solution, performing a reduction reaction, freeze-drying the solution, washing, and drying to obtain an amino quaternary ammonium salt polyurethane finishing agent; S3. Add cotton fabric to an aqueous solution of sodium periodate and oxidize it in the dark to obtain oxidized cotton fabric; then add the oxidized cotton fabric to an aqueous solution containing an amino quaternary ammonium salt polyurethane finishing agent, perform a finishing reaction, filter, wash, and dry to obtain an antibacterial and breathable fabric.

2. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In the S1, the mass ratio of 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane and 5-nitroisophenylene (N-dimethylaminoethylformamide) is 100:(14-16).

3. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In S1, the temperature of the quaternization reaction is 100-140° C. and the time is 36-72 hours.

4. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In the S2, the mass fraction of the potassium hydroxide aqueous solution is 10-13%.

5. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In S2, the mass ratio of quaternary ammonium nitropolyurethane to sodium dithionite is 100:(120-135).

6. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In S2, the reduction reaction temperature is 70-80°C and the time is 3-4h.

7. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In the S3, the mass concentration of the amino quaternary ammonium salt polyurethane finishing agent in the aqueous solution is (20-60) g / L; in the S3, the finishing reaction temperature is 50-65° C. and the time is 1-2 hours.

8. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In S1, the preparation process of 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane is as follows: dry polyethylene glycol and isophorone diisocyanate are mixed, reacted at 70-75° C. for 1.5-2 hours, and then 3-chloro-2-hydroxypropionic acid is added, and the molar ratio of polyethylene glycol, isophorone diisocyanate and 3-chloro-2-hydroxypropionic acid is controlled to be 1:(2.2-2.4):(2.6-3); reacted for 30-40 minutes, cooled, and obtained 3-chloro-2-hydroxypropionic acid-terminated polyether polyurethane.

9. The preparation process of the antibacterial breathable fabric according to claim 1, characterized in that: In S1, the preparation process of 5-nitroisophthaloyl di(N-dimethylaminoethylformamide) is as follows: 5-nitroisophthaloyl chloride, N,N-dimethylethylenediamine and triethylamine in a molar ratio of 1:(2-2.2):(2-2.2) are added to dichloromethane, reacted at room temperature for 4-6 hours, distilled under reduced pressure, washed and recrystallized to obtain 5-nitroisophthaloyl di(N-dimethylaminoethylformamide).

10. An antibacterial breathable fabric, characterized in that: The fabric is prepared by the preparation process described in any one of claims 1 to 9.

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