Washable antibacterial protective mask and preparation method thereof

Abstract

The invention provides a washable antibacterial protective mask, a mask main body comprises three layers of structures, an antibacterial layer, a filter layer and a skin contact layer are sequentially arranged from outside to inside, the antibacterial layer comprises a halamine compound 3-(4 '-vinylbenzyl)-5, 5-dimethylhydantoin with an amide structure, the filter layer is a polytetrafluoroethylene fiber composite film, and the skin contact layer is a non-woven fabric. The fabric of the skin contact layer is a real silk fabric; the preparation method comprises the following steps: firstly, dipping a fabric in a mixed solution of an antibacterial agent 3-(4 '-vinylbenzyl)-5, 5-dimethylhydantoin (VBDMH) and an initiator, carrying out ultrasonic dispersion, carrying out a rolling-baking-baking process on the fabric after dipping is finished, washing to remove unreacted monomers on the surface of the fabric after a reaction is finished, drying, chlorinating with a pypocholoride solution, and washing with water to obtain the antibacterial fabric. And then the mask body is obtained by sewing the filter layer and the skin contact layer together. The antibacterial agent for the mask is rapid and direct in sterilization, simple and convenient in finishing method, low in cost, high in economic benefit and reusable.

Description

Technical Field

[0001] This invention relates to the field of protective mask technology, specifically to a washable antibacterial protective mask and its preparation method. Background Technology

[0003] Currently, most commercially available masks are disposable products made of materials such as polypropylene and polyethylene. These materials themselves do not have antibacterial properties and are difficult to degrade in the natural environment. Furthermore, these masks have a short lifespan and are consumed in large quantities; improper disposal after disposal can easily cause microplastic pollution and other environmental risks. Existing antibacterial masks still have the following limitations: 1. Using bamboo charcoal fiber nonwoven fabric as the filter layer still makes them disposable consumables, difficult to reuse; 2. Disposable masks lack mechanical stability, and long-term wear may cause surface fiber shedding, easily leading to contact dermatitis; 3. Existing halogenated amine antibacterial agents, although with fast sterilization rates and long-lasting antibacterial effects, have relatively complex hydrophobic modification processes when used in mask materials, limiting their industrial application; 4. Antibacterial agents used in post-treatment have problems such as short sterilization duration, poor washability, and poor durability.

[0004] Therefore, researchers urgently need to develop an antibacterial mask that has a long-lasting sterilization effect, is water-resistant, and has a simple manufacturing process. Summary of the Invention

[0005] To address the problems in existing technologies, this invention designs a washable antibacterial protective mask. A haloamine compound with an amide structure, 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH), is applied as an antibacterial agent to the outer fabric of the mask using a "roll-dry-baking" process. Chlorination imparts antibacterial properties to the outer layer. The middle layer uses a washable and disinfectant-resistant PTFE nanofiber membrane, and the inner layer is made of silk fabric. The interaction of these three materials provides more comprehensive protection.

[0006] To achieve the above technical objectives, the present invention provides a washable antibacterial protective mask, the main body of which includes a three-layer structure, wherein an antibacterial layer, a filter layer and a skin contact layer are arranged sequentially from the outside to the inside.

[0007] The antibacterial layer comprises a halogen amine compound with an amide structure, 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin;

[0008] The filter layer is a polytetrafluoroethylene fiber composite membrane;

[0009] The skin contact layer fabric is made of silk.

[0010] In some technical solutions of the present invention, the antibacterial layer fabric is polyester.

[0011] In some technical solutions of this invention, the polytetrafluoroethylene fiber composite membrane is a composite membrane of polytetrafluoroethylene fiber membrane and polyethylene / polypropylene bicomponent fiber membrane. It possesses good filtration performance while also exhibiting good mechanical strength, maintaining its intact fiber membrane structure even after washing, ensuring that filtration performance is not affected after washing.

[0012] In some technical solutions of the present invention, the porosity of the polytetrafluoroethylene fiber composite membrane is ≥95%.

[0013] In some technical solutions of the present invention, the filtration efficiency of the polytetrafluoroethylene fiber composite membrane is ≥95%.

[0014] In some technical solutions of the present invention, the fabric structure of the silk fabric includes at least one of double crepe, heavy crepe, georgette, double georgette, semper satin, plain crepe satin, elastic plain crepe satin, etc.

[0015] In some technical solutions of the present invention, the silk fabric is dyed with natural pigments, preferably anthocyanins, which have antibacterial effects and are safe, beautiful and environmentally friendly.

[0016] This invention also provides a method for preparing a washable antibacterial protective mask, comprising at least the following steps:

[0017] Step 1: Immerse the fabric in a mixed solution of antibacterial agent 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) and initiator, disperse by ultrasonication, and after immersion, the fabric is subjected to a "roll-dry-bake" process to transfer the antibacterial agent onto the fabric. After the reaction is complete, wash to remove unreacted monomers from the fabric surface and dry.

[0018] Step 2: Chlorinate with hypochlorite solution to obtain the antibacterial layer of the mask;

[0019] Step 3: Sew the antibacterial layer, filter layer and skin contact layer together to obtain the main body of the mask.

[0020] In some technical solutions of the present invention, the preparation process of the antibacterial agent 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) in step 1 includes at least the following steps: (1) Take an equimolar mass of 5,5-dimethylhydantoin and hydroxide and dissolve them in 50-100 ml of ethanol solution, and reflux them in a water bath at 90-100°C for 10-20 min to obtain solution A; (2) Take an equimolar mass of 4-vinylbenzyl chloride and dissolve it in 40-60 ml of methanol solution to obtain solution B; (3) Slowly add solution B to solution A and react at 60°C for 10-15 h; (4) After the reaction is completed, filter, rotary evaporate, wash and dry to obtain the antibacterial agent. Further, the hydroxide in step (1) is selected from sodium hydroxide or potassium hydroxide.

[0021] In some technical solutions of the present invention, the mass fraction of the antibacterial agent 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) in the mixed solution in step 1 is 1-3%.

[0022] In some technical solutions of the present invention, in step 1, the photoinitiator is selected from 2,2-azobisisobutyronitrile (AIB). Further, the amount of the initiator added is 1%-3% of the mass of the antibacterial agent, preferably 2%.

[0023] In some technical solutions of the present invention, in step 1, the solvent of the mixed solution is ethanol and water, and preferably the volume ratio of ethanol to water is 3:7, which provides relatively good solubility for the antibacterial agent.

[0024] In some technical solutions of this invention, in step 1, the bath ratio of the fabric to the mixed solution is 1:50-100. Different bath ratios need to be selected depending on the weight of the fabric to ensure complete immersion.

[0025] In some technical solutions of the present invention, in step 1, the ultrasonic dispersion time is 20-30 min.

[0026] In some technical solutions of the present invention, the "roll-dry-bake" process in step 1 includes at least: "dip-roll" the fabric twice in a rolling mill with a roll-off rate of 100%; pre-dry the dipped and rolled fabric at 60°C for 3-5 minutes; and bake it at 120°C-150°C for 5 minutes.

[0027] In some technical solutions of the present invention, in step 2, the hypochlorite includes at least one selected from sodium hypochlorite, sodium hypobromite, and calcium hypochlorite. Preferably, the hypochlorite is sodium hypochlorite, and the sodium hypochlorite solution has a mass concentration of 10%.

[0028] In some technical solutions of the present invention, the chlorination process in step 2 includes at least the following steps: preparing a sodium hypochlorite solution at a bath ratio of 1:100, then adding 10% dilute sulfuric acid solution to adjust the pH of the solution to about 7, placing the antibacterial treated polyester fabric in the solution, immersing it at room temperature for 1 hour, removing the polyester fabric after the time is up, washing it with a large amount of deionized water to remove the active chlorine on the surface, and then drying it at 45°C.

[0029] In some technical solutions of the present invention, the skin contact layer in step 3 is treated with natural pigments, and more preferably with anthocyanin staining.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The halogenated antibacterial agent 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) used in this invention has a broad-spectrum antibacterial effect against bacteria, fungi, and other microorganisms, does not produce toxic side effects on the human body, and is environmentally friendly. Furthermore, the antibacterial agent kills bacteria rapidly and directly, and the preparation method is simple, low-cost, and highly economical.

[0032] 2. The inner layer of the antibacterial mask prepared by this invention is made of silk fabric, which is skin-friendly, comfortable, and breathable, improving the wearing comfort of the mask and reducing the risk of facial redness and allergies. Furthermore, silk fabric has a certain degree of antibacterial and bacteriostatic effects and will not disrupt the microecological balance of human skin and mucous membranes.

[0033] 3. The mask prepared by this invention retains good antibacterial and filtration effects after washing. The middle filter layer uses a polytetrafluoroethylene fiber composite membrane, which has good filtration performance as well as good mechanical strength. After 20 washing cycles, its fiber structure does not change significantly and it still has good filtration performance. The outer layer of antibacterial treated polyester fabric recovers to 85% of its initial chlorine content after 20 washing cycles, indicating that it has antibacterial regenerability, long-lasting antibacterial effect, and can be reused, reducing resource waste and environmental pollution. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the main structure of a three-layer antibacterial mask prepared according to the present invention. Detailed Implementation

[0036] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. These described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0037] Preparation of the antibacterial agent VBDMH: 13g of 5,5-dimethylhydantoin and 4.0g of sodium hydroxide were dissolved in 90ml of ethanol solution. The solution was poured into a single-necked flask and refluxed in a water bath at 90-95℃ for 15 min. An equimolar amount of 4-vinylbenzyl chloride and 45ml of methanol solution were added to the above system. The mixture was transferred to an oil bath and reacted at 60℃ for 12 h. After the reaction was completed, the prepared solution was filtered, rotary evaporated, and dried for 24 h to obtain a pale yellow powder.

[0038] Example 1

[0039] Step 1: Immerse the fabric in a mixed solution of ethanol and water (volume ratio of ethanol to water is 3:7) of BVBDMH and initiator AIBN at a liquor ratio of 1:50, where the mass concentration of BVBDMH is 1% and the mass concentration of AIBN is 2%. Disperse the solution ultrasonically for 30 minutes. After immersion, use a "puff-dry-bake" process to remove unreacted monomers. The puffing rate is 100%. Pre-dry the puffed fabric at 60°C for 3 minutes and then bake it at 150°C for 5 minutes. Wash the fabric with a large amount of anhydrous ethanol to remove unreacted monomers and dry it below 45°C.

[0040] Step 2: Prepare a sodium hypochlorite solution at a bath ratio of 1:100, then add 10% dilute sulfuric acid solution to adjust the pH of the solution to about 7. Place the antibacterial treated polyester fabric in the solution and immerse it at room temperature for 1 hour. After the time is up, take out the polyester fabric and wash it with a large amount of deionized water to remove the active chlorine on the surface. Then dry it at 45°C to obtain the antibacterial layer of the mask.

[0041] Step 3: Sew together the antibacterial layer, PTFE nanofiber membrane (YKF040311, Suzhou Youkefa Company) and silk layer (treated with anthocyanin) obtained in Step 2 to obtain the main body of the mask.

[0042] Example 2

[0043] Step 1: Immerse the fabric in a mixed solution of ethanol and water (volume ratio of ethanol to water is 3:7) of BVBDMH and initiator AIBN at a liquor ratio of 1:100, where the mass concentration of BVBDMH is 3% and the mass concentration of AIBN is 2%. Disperse the solution ultrasonically for 30 minutes. After immersion, use a "puff-dry-bake" process to remove unreacted monomers. The puffing rate is 100%. Pre-dry the puffed fabric at 60°C for 3 minutes and then bake it at 150°C for 5 minutes. Wash the fabric with a large amount of anhydrous ethanol to remove unreacted monomers and dry it below 45°C.

[0044] Step 2: Prepare a sodium hypochlorite solution at a bath ratio of 1:100, then add 10% dilute sulfuric acid solution to adjust the pH of the solution to about 7. Place the antibacterial treated polyester fabric in the solution and immerse it at room temperature for 1 hour. After the time is up, take out the polyester fabric and wash it with a large amount of deionized water to remove the active chlorine on the surface. Then dry it at 45°C to obtain the antibacterial layer of the mask.

[0045] Step 3: Sew together the antibacterial layer, PTFE nanofiber membrane (YKF040311, Suzhou Youkefa Company) and silk layer (treated with anthocyanin) obtained in Step 2 to obtain the main body of the mask.

[0046] Example 3

[0047] Step 1: Immerse the fabric in a mixed solution of ethanol and water (volume ratio of ethanol to water is 3:7) of BVBDMH and initiator AIBN at a liquor ratio of 1:75, where the mass concentration of BVBDMH is 2% and the mass concentration of AIBN is 2%. Disperse the solution ultrasonically for 30 minutes. After immersion, use a "puff-dry-bake" process to remove unreacted monomers. The puffing rate is 100%. Pre-dry the puffed fabric at 60°C for 3 minutes and then bake it at 150°C for 5 minutes. Wash the fabric with a large amount of anhydrous ethanol to remove unreacted monomers and dry it below 45°C.

[0048] Step 2: Prepare a sodium hypochlorite solution at a bath ratio of 1:100, then add 10% dilute sulfuric acid solution to adjust the pH of the solution to about 7. Place the antibacterial treated polyester fabric in the solution and immerse it at room temperature for 1 hour. After the time is up, take out the polyester fabric and wash it with a large amount of deionized water to remove the active chlorine on the surface. Then dry it at 45°C to obtain the antibacterial layer of the mask.

[0049] Step 3: Sew together the antibacterial layer, PTFE nanofiber membrane (YKF040311, Suzhou Youkefa Company) and silk layer (treated with anthocyanin) obtained in Step 2 to obtain the main body of the mask.

[0050] Comparative Example 1

[0051] A three-layer structure mask, which differs from Example 1 in that the antibacterial layer is made of unchlorinated polyester that has not been treated with antibacterial agents.

[0052] Comparative Example 2

[0053] A three-layer structure mask, which differs from Example 1 in that the filter layer is made of polypropylene meltblown fabric.

[0054] I. Test Experiment:

[0055] 1. Antibacterial performance test:

[0056] The antimicrobial performance of the mask was tested according to the revised AATCC 100-2004 antimicrobial test standard. The specific method is as follows: Take 25 µL of bacterial suspension (the inoculation concentrations of Staphylococcus aureus and Escherichia coli are 7.2 × 10⁻⁶). 6 cfu / sample and 6.0×10 6 CFU / sample was dropped onto unchlorinated polyester, chlorinated polyester, silk, and a three-layer mask (2.54 cm × 2.54 cm) prepared in Examples 1-3, respectively. The mixture was sandwiched for a certain period to ensure full contact between the bacterial solution and the fabric. After 1, 5, and 30 minutes of contact, the fabric in contact with the bacteria was placed into a 15 mL conical tube containing 5 mL of phosphate buffer solution. After vortexing to homogenize, the gradient drop plate method was used to calculate the corresponding sterilization rate.

[0057] 2. Filtration Performance Test: The saline gas filtration performance of the mask was tested according to GB / T32610-2016 "Technical Specification for Daily Protective Masks". The specific test method is as follows: Prepare the sample to be tested, then prepare a NaCl saline solution. Weigh 60g of NaCl, add 3L of deionized water to the container, and stir to mix evenly. The diameter of the NaCl solid aerosol used in the test is (0.075±0.02)μm, the gas flow rate is set to 85 L / min, the experiment needs to be carried out at a temperature of about 25℃ and a humidity of about 30%, and finally the data is analyzed.

[0058] 3. Washing Stability Test: To test whether the prepared masks still retain basic protective performance after a certain number of washing cycles, tests were conducted according to the AATCC 61-2010 test standard. The specific test method is as follows: Samples of Examples 1-3 and the comparative examples were cut into 13.5cm × 13.5cm pieces. 200ml of 0.15% soap solution was then poured into a steel cup. The steel cup was fixed on a color fastness-to-wash instrument, and the experimental temperature was set at 49℃. After 20 washing cycles, the steel cup was removed, the sample was taken out, and the fabric surface was washed with plenty of tap water to test filtration performance and the recoverability of active chlorine.

[0059] II. Test Results Explanation

[0060] 1. Explanation of antibacterial test results

[0061] The results are shown in Table 1. As can be seen from Table 1, the chlorinated polyester fabric can kill all two types of bacteria within 5 minutes of contact, indicating that the outer fabric has excellent antibacterial properties. After 30 minutes of contact with bacteria, the inner silk fabric showed that both types of bacteria were reduced by nearly 100%, also demonstrating a certain degree of antibacterial activity. After 1 minute of contact with bacteria, the outer chlorinated polyester fabric reduced the two types of bacteria by 98.54% and 99.62%, respectively, while the inner silk fabric reduced the two types of bacteria by 83.00% and 88.60%, respectively. However, the three-layer mask prepared showed that both types of bacteria were completely killed after 1 minute of contact with bacteria, indicating that the combination of chlorinated polyester and silk exhibits a more superior bactericidal effect.

[0062] Table 1 Antibacterial test results

[0063]

[0064] 2. Explanation of the results of the water wash resistance stability test

[0065]

[0066] The washability is shown in the table above. In the examples, after washing, the filtration efficiency of the masks increased rather than decreased, rising from 95-96% to over 97%, indicating that washing had no significant impact on the filtration efficiency; the washed masks still possessed high filtration efficiency. Furthermore, after 20 wash cycles and rechlorination, the active chlorine content recovered at over 85%, demonstrating that the masks still possessed good antibacterial and regenerable properties after washing, indicating that the masks prepared in Examples 1-3 are reusable.

[0067] Finally, it should be noted that although the present invention has been described in detail above with general descriptions and specific embodiments, the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A washable antibacterial protective mask, characterized in that, The mask body includes a three-layer structure, with an antibacterial layer, a filter layer, and a skin contact layer arranged sequentially from the outside to the inside. The antibacterial layer comprises a halogen amine compound with an amide structure, 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin; The filter layer is a polytetrafluoroethylene fiber composite membrane; The skin contact layer fabric is made of silk.

2. The washable antibacterial protective mask according to claim 1, characterized in that, In some technical solutions of the present invention, the antibacterial layer fabric is polyester, and the polytetrafluoroethylene fiber composite membrane is a composite membrane of polytetrafluoroethylene fiber membrane and polyethylene polypropylene bicomponent fiber membrane.

3. The washable antibacterial protective mask according to claim 1, characterized in that, In some technical solutions of the present invention, the porosity of the polytetrafluoroethylene fiber composite membrane is ≥95%; the filtration efficiency of the polytetrafluoroethylene fiber composite membrane is ≥95%.

4. The washable antibacterial protective mask according to claim 1, characterized in that, The fabric structure includes at least one of double crepe, heavy crepe, georgette, double georgette, semper satin, plain crepe satin, and elastic plain crepe satin; the fabric is dyed with natural pigments.

5. A method for preparing a washable antibacterial protective mask, characterized in that, At least the following steps are included: Step 1: Immerse the fabric in a mixed solution of antibacterial agent 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) and initiator, disperse by ultrasonication, and after immersion, the fabric is subjected to a "roll-dry-bake" process to transfer the antibacterial agent onto the fabric. After the reaction is complete, wash to remove unreacted monomers from the fabric surface and dry. Step 2: Chlorinate with hypochlorite solution to obtain the antibacterial layer of the mask; Step 3: Sew the antibacterial layer, filter layer and skin contact layer together to obtain the main body of the mask.

6. The method for preparing a washable antibacterial protective mask according to claim 5, characterized in that, The antibacterial agent 3-(4'-vinylbenzyl)-5,5-dimethylhydantoin (VBDMH) mentioned in step 1 has a mass fraction of 1-3% in the mixed solution.

7. The method for preparing a washable antibacterial protective mask according to claim 5, characterized in that, In step 1, the bath ratio of the fabric to the mixed solution is 1:50-100; the ultrasonic dispersion time is 20-30 min.

8. The method for preparing a washable antibacterial protective mask according to claim 5, characterized in that, The "pad-dry-bake" process described in step 1 includes at least the following steps: "dip-pad" the fabric twice in a padding machine with a padding rate of 100%; pre-dry the padded fabric at 60°C for 3-5 minutes; and bake it at 120°C-150°C for 5 minutes.

9. The method for preparing a washable antibacterial protective mask according to claim 5, characterized in that, In step 2, the hypochlorite includes at least one of sodium hypochlorite, sodium hypobromite, and calcium hypochlorite. Preferably, the hypochlorite is sodium hypochlorite, and the sodium hypochlorite solution has a mass concentration of 10%.

10. The method for preparing a washable antibacterial protective mask according to claim 5, characterized in that, The chlorination process in step 2 includes at least the following steps: preparing a sodium hypochlorite solution at a bath ratio of 1:100, then adding 10% dilute sulfuric acid solution to adjust the pH of the solution to about 7, placing the antibacterial treated polyester fabric in the solution, immersing it at room temperature for 1 hour, removing the polyester fabric after the time is up, washing it with a large amount of deionized water to remove the active chlorine on the surface, and then drying it at 45°C.

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