Non-irritating soft cotton towel and preparation method thereof

Abstract

The invention discloses a non-irritant soft cotton towel and a preparation method thereof, and relates to the technical field of life hygienic products. The preparation method comprises the following specific preparation steps: swelling pure cotton fibers with a sodium hydroxide and polyethylene glycol aqueous solution, adding allyl glycidyl ether, reacting to introduce carbon-carbon double bonds, washing and drying to obtain modified cotton fibers; immersing the modified cotton fiber into deionized water containing methacryloyloxyethyl trimethyl ammonium chloride, potassium persulfate and sodium hydrogen sulfite, reacting in a nitrogen atmosphere, washing and drying to obtain the antibacterial cotton fiber. Preparing a zinc nitrate solution A and a tea polyphenol solution B, mixing and reacting to obtain zinc-tea polyphenol coordination compound sol; antibacterial cotton fibers are soaked in the sol, ultrasonically dried to obtain dual antibacterial fibers, the dual antibacterial fibers are mixed with common cotton fibers, and the soft cotton towel is obtained through wet laying, spunlace reinforcement and drying. The soft cotton towel prepared by the method is non-irritant to skin and has good antibacterial performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of daily hygiene products, in particular to a non-irritating cotton soft towel and a preparation method thereof. BACKGROUND

[0002] With the improvement of residents' living quality and the enhancement of personal care consciousness, cotton soft towels have been widely used to replace traditional paper towels due to their advantages such as softness, skin-friendliness, degradability, and convenience of use, and have been applied to scenarios such as facial cleaning, infant care, and sensitive skin care, becoming one of the core products in the field of daily personal care. The current market demand for cotton soft towels has upgraded from basic cleaning functions to both functionality and safety, among which antibacterial performance and non-irritation have become the core indicators of consumer attention, especially for infants, pregnant women, and people with sensitive skin, higher requirements for the skin compatibility, ingredient safety, and antibacterial durability of the products have been put forward. However, the existing cotton soft towel products still have many technical defects: first, the antibacterial performance is insufficient or unstable, traditional pure cotton soft towels rely on the natural properties of the material and lack active antibacterial ability, and pathogenic bacteria such as Escherichia coli and Staphylococcus aureus are easy to breed in a humid environment, which poses a risk of cross-infection; although some products add chemical antibacterial agents to improve antibacterial effect, such antibacterial agents are prone to migration due to washing or storage, resulting in a decline in effect, and some ingredients are irritating to the skin mucosa, which may cause redness and itching in sensitive people after long-term contact, making it difficult to meet the needs of special groups. Second, there is a contradiction between the demand for non-irritation and the realization of functions, existing processes often introduce surfactants, fragrances, preservatives, and other assistants to improve softness, water absorption, or antibacterial properties, which improves physical properties but significantly increases the risk of skin irritation, especially for infants with weak skin barriers, existing products are difficult to balance functionality and mildness, and the market lacks high-quality cotton soft towels with effective antibacterial and non-irritating properties. SUMMARY

[0003] The purpose of the present application is to provide a cotton soft towel that solves the technical problems of insufficient antibacterial performance and irritation of the cotton soft towel mentioned in the background. The cotton soft towel prepared by the present application has good antibacterial performance and is non-irritating to the skin.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A preparation method of a non-irritating cotton soft towel, comprising the following steps: S1, immersing pure cotton fibers in a sodium hydroxide and polyethylene glycol aqueous solution for swelling treatment, then adding allyl glycidyl ether under stirring conditions for reaction, introducing carbon-carbon double bonds to the surface of the cotton fibers, washing and drying after the reaction is completed, and obtaining modified cotton fibers; S2, the modified cotton fibers are immersed in deionized water in which methacryloyloxyethyl trimethyl ammonium chloride, potassium persulfate and sodium bisulfite are dissolved, and the reaction is carried out under a nitrogen atmosphere. After the reaction is completed, the product is washed with hot water and an ethanol aqueous solution, and dried to obtain antibacterial cotton fibers; S3, zinc nitrate is dissolved in an ethanol and water mixed solvent to obtain solution A, and tea polyphenol is dissolved in an ethanol and water mixed solvent to obtain solution B. Solution B is added dropwise to solution A under stirring to form a zinc-tea polyphenol coordination compound sol; S4, the antibacterial cotton fibers are immersed in the zinc-tea polyphenol coordination compound sol and subjected to ultrasonic treatment, and then taken out and dried to obtain double antibacterial fibers; S5, the double modified antibacterial fibers are mixed with ordinary cotton fibers, and a web is formed by a wet laying process. The web is subjected to water jet reinforcement, and dried to obtain a cotton soft towel.

[0005] In the technical scheme of the present application, a permanent quaternary ammonium salt antibacterial layer is first constructed on the surface of the cotton fibers by a chemical method, and the high efficiency antibacterial property is derived from the cationic property of the quaternary ammonium salt molecule. After the cotton fibers are modified by allyl glycidyl ether, a carbon-carbon double bond which can participate in radical polymerization is introduced. Subsequently, under an oxidation-reduction initiation system, the quaternary ammonium salt monomer (methyl acryloyloxyethyl trimethyl ammonium chloride) is firmly grafted to the fiber surface by copolymerization in the form of a covalent bond, so that the quaternary ammonium nitrogen cation in the molecule is exposed to the outside. When the negatively charged bacteria contact the fiber surface, the positive and negative charges attract each other, and the long-chain alkyl of the quaternary ammonium salt will insert into and destroy the cell membrane / cell wall structure of the bacteria, causing the contents of the cells to leak, thereby efficiently killing the bacteria. This contact-activated bactericidal mechanism acts quickly and is not easy to produce drug resistance, and since the quaternary ammonium salt is grafted by a firm covalent bond rather than physical coating, it has excellent washing resistance and durability, providing a long-acting first antibacterial barrier for the cotton soft towel. Then, by loading a zinc-tea polyphenol coordination compound, a synergistic antibacterial system is constructed, which is based on the synergistic antibacterial effect of metal ions and polyphenols and the antioxidant properties of tea polyphenol. Zinc ions themselves have antibacterial activity, they can penetrate into the interior of bacteria, interfere with enzyme systems and metabolic processes, and destroy cell integrity. Secondly, the catechol structure in the tea polyphenol molecule not only forms a stable complex with zinc ions to avoid rapid release of metal ions, but also can destroy the cell membrane of microorganisms itself. In addition, tea polyphenol is a strong natural antioxidant that can effectively scavenge free radicals in the environment, reduce oxidative irritation to the skin, and has anti-inflammatory properties. It is complementary to the above-mentioned contact type bactericidal quaternary ammonium salt, forming a second protective layer with functions of rapid killing, oxidative damage, antioxidant and anti-inflammatory. Figure 1 SEM image of the surface of the cotton soft towel prepared in the present application.

[0006] Traditional physical coating of antibacterial agents is easy to fall off from the fiber, and high concentration of free antibacterial agents directly contacting the skin can easily cause stinging or allergy. The present application covalently grafts quaternary ammonium salt molecules firmly on the fiber, greatly reducing the release of free molecules, ensuring that the antibacterial agent mainly plays a role when contacting bacteria, rather than acting on the skin in a large area, thereby significantly reducing the potential irritation. Secondly, the selected zinc ions and tea polyphenols are both biocompatible ingredients. Zinc is an essential trace element for the human body, which has skin repair and soothing effects; tea polyphenols are natural plant extracts, which have anti-inflammatory and antioxidant activities, and can further soothe the skin, realizing the directional and slow-release of antibacterial ingredients, i.e. mainly targeting pathogenic microorganisms, rather than causing harm to skin cells, thereby ensuring the safety and mildness of the skin when in contact with the skin, realizing the non-irritation to the skin.

[0007] Preferably, in step S1, the amount of allyl glycidyl ether added is 10-15wt% of the mass of the pure cotton fiber.

[0008] Preferably, in step S1, the reaction temperature is 60-65℃, and the reaction time is 3-5h.

[0009] Preferably, in step S2, the mass ratio of the loaded epoxy cotton fiber to methacryloyloxyethyl trimethyl ammonium chloride is 10:1-3.

[0010] Preferably, in step S2, the reaction temperature is 50-55℃, and the reaction time is 4-6h.

[0011] Preferably, in step S3, the mass ratio of zinc nitrate to tea polyphenol is 5:2-3.

[0012] Preferably, in step S4, the antibacterial cotton fiber is pretreated before being immersed in the zinc-tea polyphenol coordination compound sol, including the following steps: 3-aminopropyl triethoxysilane is added to a mixed solution of ethanol and water, stirred and dissolved to obtain a 3-aminopropyl triethoxysilane solution, the antibacterial cotton fiber is immersed in the 3-aminopropyl triethoxysilane solution, the pH is adjusted to 4.5-5.5, heated and reacted, and then washed and dried to obtain the antibacterial cotton fiber.

[0013] In the technical solution of the present application, the team of the present application found through in-depth research that after the surface of the cotton fiber is grafted with a strong positive charge quaternary ammonium salt polymer, the positively charged quaternary ammonium salt fiber surface will be coordinated with the same partially positively charged Zn 2+The center generates electrostatic repulsion, hinders the effective penetration and close adhesion of the zinc-tea polyphenol coordination compound to the inside of the fiber, causes the zinc-tea polyphenol compound to be unable to effectively bind on the fiber, and further affects the antibacterial performance. To further solve this technical problem, the application pretreats the antibacterial cotton fiber before it is immersed in the zinc-tea polyphenol coordination compound sol, and grafts 3-aminopropyl triethoxysilane on the antibacterial cotton fiber, so that a large number of amino functional groups are loaded on the cotton fiber, which can form strong coordination with Zn 2+ The unoccupied coordination sites form strong coordination, so that the zinc-tea polyphenol compound is combined on the fiber, and the antibacterial performance is further improved.

[0014] As preferred, the concentration of the 3-aminopropyl triethoxysilane solution is 2-5 wt%.

[0015] As preferred, in the step S5, the mass ratio of the ordinary cotton fiber to the double-modified antibacterial fiber is 2:1-2.

[0016] A non-irritating cotton wipe is prepared by the above method.

[0017] Compared with the prior art, the application has the following beneficial effects: 1. The first antibacterial barrier is formed by covalently grafting quaternary ammonium salt, the quaternary ammonium nitrogen cation can quickly attract and destroy the bacterial cell membrane, and the covalent bond connection ensures long-acting antibacterial after washing; the second barrier is formed by loading zinc-tea polyphenol coordination compound, the zinc ion interferes with bacterial metabolism, the tea polyphenol destroys the cell membrane and has antioxidant and anti-inflammatory effects, and the two achieve the dual antibacterial effects of rapid killing and continuous protection.

[0018] 2. The positive electricity of the quaternary ammonium salt fiber and the electrostatic repulsion of Zn 2+ cause the zinc-tea polyphenol to be difficult to adhere, the problem is solved by pretreating and grafting 3-aminopropyl triethoxysilane to introduce amino groups, the amino groups form strong coordination with Zn 2+ to make the zinc-tea polyphenol stably bind on the fiber, ensure the effective synergy of the double antibacterial system, and further strengthen the antibacterial performance.

[0019] 3. The quaternary ammonium salt is anchored on the surface of the fiber by covalent grafting, greatly reduces the precipitation of free antibacterial agents, avoids its contact with the skin in a large area; at the same time, the biocompatible zinc ion and natural tea polyphenol are selected to realize the directional effect of the antibacterial components on bacteria and not damage the skin cells, and ensure that the cotton wipe is soft and non-irritating when contacting the skin. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The SEM image of the surface of the cotton wipe prepared by the application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0022] Embodiment 1 A preparation method of non-irritating cotton wipes, comprising the following steps: Step 1: 100 g of pure cotton fibers were weighed and completely immersed in 1000 mL of an aqueous solution containing 8% (w / v) sodium hydroxide and 4% (w / v) polyethylene glycol-400, and were subjected to swelling treatment at room temperature for 1 h. Subsequently, the system was transferred to a three-necked flask equipped with a mechanical stirrer and a condensation reflux device, and was warmed to 63°C and kept at constant temperature. Under the condition of a stirring rate of 200 rpm, 14 g of allyl glycidyl ether was slowly added dropwise, and the reaction was continued at this temperature for 4 h. After the reaction was completed, the modified fibers were taken out, washed repeatedly to neutralization under ultrasonic assistance using a large amount of deionized water, and finally placed in a 80°C air-drying oven for sufficient drying, to obtain modified cotton fibers.

[0023] Step 2: 25 g of methacryloyloxyethyl trimethyl ammonium chloride, 0.3 g of potassium persulfate and 0.15 g of bisulfite were added to 800 mL of deionized water, stirred and dissolved to obtain a mixed solution. 100 g of modified cotton fibers were completely immersed in the above mixed solution, and the pH value was adjusted to 5.5 using a 0.1 mol / L hydrochloric acid solution. Under the atmosphere of continuous nitrogen protection, the temperature was slowly increased to 53°C and kept constant for 5 h. After the reaction was completed, the fibers were taken out, first washed with hot water at 60°C, and then washed with 50% (v / v) ethanol aqueous solution under ultrasonic assistance for 20 min to completely remove unreacted monomers and homopolymers, and finally dried at 80°C to obtain antibacterial cotton fibers.

[0024] Step 3: 2.50 g of zinc nitrate nonahydrate was dissolved in 400 mL of ethanol-water mixed solvent (V:V=1:1) with magnetic stirring until completely dissolved to obtain solution A. 1.4 g of tea polyphenol was dissolved in 100 mL of the same proportion of ethanol-water solvent to obtain solution B. Under vigorous stirring (500 rpm), solution B was slowly added dropwise to solution A using a constant pressure dropping funnel, and the reaction was continued at room temperature for 4 h. The solution gradually changed from colorless to dark brown clear liquid to obtain a zinc-tea polyphenol coordination compound sol.

[0025] Step 4: 3-aminopropyltriethoxysilane was added into a mixed solution of ethanol and water (V:V=8:2) and stirred to dissolve to obtain a silane solution with a concentration of 4wt%. The solution pH was adjusted to 5.0 with acetic acid, and the antibacterial cotton fibers were immersed in the solution and reacted at 60°C for 2h. After the reaction, the fibers were taken out, washed with ethanol for 3 times and dried. Subsequently, the pretreated fibers were completely immersed in the zinc-tea polyphenol coordination sol and ultrasonically treated for 30min under a power of 40kHz and 300W. After the completion of the immersion, the fibers were taken out and evenly laid out to dry in a 65°C air-drying oven for 4h to obtain the double antibacterial fibers.

[0026] Step 5: The double modified antibacterial fibers were mixed with ordinary cotton fibers at a mass ratio of 1.8:2. After being mixed by an opener, a wet-laid process was adopted to control the concentration of the web-forming slurry at 0.05%, and a 80g / m 2 of the formed web was sent to a hydroentanglement reinforcement device for positive and reverse hydroentanglement (water jet head aperture 0.12mm, water pressure 120bar, cloth surface speed 5m / min). Subsequently, the hydroentangled cloth was sent to a cylinder dryer to be dried at a temperature of 95°C until the water content was less than 5% to obtain the finished product of the cotton soft towel.

[0027] Example 2 A method for preparing a non-irritating cotton soft towel, comprising the following steps: Step 1: 100g of pure cotton fibers were completely immersed in 1000mL of an aqueous solution containing 8%(w / v) sodium hydroxide and 4%(w / v) polyethylene glycol-400, and swelled at room temperature for 1h. Subsequently, the system was transferred to a three-necked flask equipped with a mechanical stirrer and a condensation reflux device, and heated to 63°C and kept constant. Under the condition of stirring rate 200rpm, 11g of allyl glycidyl ether was slowly added, and the reaction was continued at this temperature for 4h. After the reaction was completed, the modified fibers were taken out, washed repeatedly to neutral with a large amount of deionized water under ultrasonic assistance, and finally dried in an 80°C air-drying oven to obtain the modified cotton fibers.

[0028] Step 2: 12g of methacryloyloxyethyl trimethyl ammonium chloride, 0.3g of potassium persulfate and 0.15g of bisulfite were added into 800mL of deionized water and stirred to dissolve to obtain a mixed solution. 100g of the modified cotton fibers were completely immersed in the above mixed solution, and the pH value was adjusted to 5.5 with 0.1mol / L hydrochloric acid solution, and slowly heated to 53°C and kept constant for 5h under the atmosphere of continuous nitrogen protection. After the reaction was completed, the fibers were taken out, washed with hot water at 60°C first, and then washed with 50% (v / v) ethanol aqueous solution under ultrasonic assistance for 20min to completely remove the unreacted monomers and homopolymers, and finally dried at 80°C to obtain the antibacterial cotton fibers.

[0029] Step 3: Weigh 2.50 g of zinc nitrate nonahydrate and dissolve it in 400 mL of ethanol-water mixed solvent (V:V = 1:1) with magnetic stirring until completely dissolved to obtain solution A. Weigh 1.2 g of tea polyphenols and dissolve it in 100 mL of the same proportion of ethanol-water solvent to obtain solution B. Under vigorous stirring (500 rpm), solution B is slowly added to solution A using a constant pressure dropping funnel, and the reaction is continued at room temperature for 4 h. The solution gradually changes from colorless to dark brown clear liquid, and a zinc-tea polyphenol coordination compound sol is obtained.

[0030] Step 4: 3-Aminopropyltriethoxysilane is added to a mixed solution of ethanol and water (V:V = 8:2) and stirred to dissolve to obtain a silane solution with a concentration of 3 wt%. The solution pH is adjusted to 4.5 with acetic acid, and the antibacterial cotton fibers are immersed in the solution and reacted at 60°C for 2 h. After the reaction, the fibers are taken out, washed with ethanol 3 times and dried. Subsequently, the pretreated fibers are completely immersed in the zinc-tea polyphenol coordination compound sol, and ultrasonic treatment is carried out at a power of 40 kHz, 300 W for 30 min. After the immersion is completed, the fibers are taken out and evenly laid out, and dried in a 65°C air drying oven for 4 h to obtain double antibacterial fibers.

[0031] Step 5: The double modified antibacterial fibers are mixed with ordinary cotton fibers at a mass ratio of 1.2:2. After being thoroughly opened and mixed by an opener, a wet laid process is used to control the concentration of the web forming slurry to be 0.05%, and a forming machine is used to form a web with a basis weight of 80 g / m 2 The formed web is sent to a hydroentanglement reinforcement device for forward and reverse hydroentanglement (water jet head aperture 0.12 mm, water pressure 120 bar, cloth surface speed 5 m / min). Subsequently, the hydroentangled cloth is sent to a cylinder dryer and dried at a temperature of 95°C until the moisture content is less than 5%, and the finished cotton towel is obtained.

[0032] Example 3 A method for preparing a non-irritating cotton towel, comprising the following steps: Step 1: Weigh 100 g of pure cotton fibers and completely immerse them in 1000 mL of an aqueous solution containing 8% (w / v) sodium hydroxide and 4% (w / v) polyethylene glycol-400, and swell at room temperature for 1 h. Subsequently, the system is transferred to a three-necked flask equipped with a mechanical stirrer and a condensation reflux device, and heated to 63°C and kept at constant temperature. Under the condition of stirring rate 200 rpm, 13 g of allyl glycidyl ether is slowly added, and the reaction is continued at this temperature for 4 h. After the reaction is completed, the modified fibers are taken out, washed repeatedly to neutral with a large amount of deionized water under ultrasonic assistance, and finally placed in an 80°C air drying oven for thorough drying to obtain modified cotton fibers.

[0033] Step 2: 20 g of methacryloyloxyethyl trimethyl ammonium chloride, 0.3 g of potassium persulfate and 0.15 g of bisulfite were added to 800 mL of deionized water, stirred and dissolved to obtain a mixed solution. 100 g of modified cotton fibers were completely immersed in the above mixed solution, the pH value was adjusted to 5.5 with 0.1 mol / L hydrochloric acid solution, and the temperature was slowly raised to 53°C under the protection of a continuous nitrogen atmosphere and reacted for 5 h. After the reaction was completed, the fibers were taken out, first washed with hot water at 60°C, then washed with 50% (v / v) ethanol aqueous solution under ultrasonic assistance for 20 min to completely remove unreacted monomers and homopolymers, and finally dried at 80°C to obtain antibacterial cotton fibers.

[0034] Step 3: 2.50 g of zinc nitrate nonahydrate was dissolved in 400 mL of ethanol-water mixed solvent (V:V=1:1) with magnetic stirring until completely dissolved to obtain solution A. 1.3 g of tea polyphenol was dissolved in 100 mL of the same proportion of ethanol-water solvent to obtain solution B. Under vigorous stirring (500 rpm), solution B was slowly added to solution A using a constant pressure dropping funnel, and the reaction was continued at room temperature for 4 h. The solution gradually changed from colorless to dark brown clear liquid to obtain a zinc-tea polyphenol complex sol.

[0035] Step 4: 3-aminopropyl triethoxysilane was added to a mixed solution of ethanol and water (V:V=8:2) and stirred and dissolved to obtain a silane solution with a concentration of 3.5 wt%. The pH of the solution was adjusted to 5.0 with acetic acid, and the antibacterial cotton fibers were immersed in the solution and reacted at 60°C for 2 h. After the reaction, the fibers were taken out, washed with ethanol for 3 times and dried. Subsequently, the pretreated fibers were completely immersed in the zinc-tea polyphenol complex sol, and ultrasonic treatment was carried out at a power of 40 kHz, 300 W for 30 min. After the immersion was completed, the fibers were taken out and evenly laid, and dried in a 65°C air drying oven for 4 h to obtain double antibacterial fibers.

[0036] Step 5: The double modified antibacterial fibers were mixed with ordinary cotton fibers at a mass ratio of 1.5:2. After being fully opened and mixed by an opener, a wet laid process was adopted, and the concentration of the web was controlled to be 0.05%. A 80 g / m 2 The formed web was sent to a hydroentanglement equipment for positive and reverse hydroentanglement (water jet head aperture 0.12 mm, water pressure 120 bar, cloth surface speed 5 m / min). Subsequently, the hydroentangled cloth was sent to a cylinder dryer and dried at a temperature of 95°C until the water content was less than 5% to obtain the finished product of cotton soft towel.

[0037] Example 4 A method for preparing a non-irritating cotton soft towel, comprising the following steps: Step 1: 100 g of pure cotton fibers were weighed and completely immersed in 1000 mL of an aqueous solution containing 8% (w / v) sodium hydroxide and 4% (w / v) polyethylene glycol-400, and were swelled at room temperature for 1 h. Subsequently, the system was transferred to a three-necked flask equipped with a mechanical stirrer and a condensing reflux device, and was heated to 65°C and kept at constant temperature. At a stirring rate of 200 rpm, 15 g of allyl glycidyl ether was slowly added dropwise, and the reaction was continued at this temperature for 5 h. After the reaction was completed, the modified fibers were taken out, washed repeatedly to neutral with a large amount of deionized water under ultrasonic assistance, and finally dried in a 80°C air-drying oven to obtain the modified cotton fibers.

[0038] Step 2: 30 g of methacryloyloxyethyl trimethyl ammonium chloride, 0.3 g of potassium persulfate and 0.15 g of bisulfite were added to 800 mL of deionized water, stirred and dissolved to obtain a mixed solution. 100 g of modified cotton fibers were completely immersed in the above mixed solution, and the pH value was adjusted to 5.5 with 0.1 mol / L hydrochloric acid solution. Under the atmosphere of continuous nitrogen protection, the temperature was slowly increased to 55°C and kept at constant temperature for 6 h. After the reaction was completed, the fibers were taken out, first washed with hot water at 60°C, and then washed with 50% (v / v) ethanol aqueous solution under ultrasonic assistance for 20 min to completely remove the unreacted monomers and homopolymers, and finally dried at 80°C to obtain the antibacterial cotton fibers.

[0039] Step 3: 2.50 g of zinc nitrate nonahydrate was dissolved in 400 mL of ethanol-water mixed solvent (V:V=1:1) with magnetic stirring until completely dissolved to obtain solution A. 1.5 g of tea polyphenol was dissolved in 100 mL of the same proportion of ethanol-water solvent to obtain solution B. Under vigorous stirring (500 rpm), solution B was slowly added to solution A using a constant pressure dropping funnel, and the reaction was continued at room temperature for 4 h. The solution gradually changed from colorless to dark brown clear liquid to obtain a zinc-tea polyphenol coordination compound sol.

[0040] Step 4: 3-aminopropyl triethoxysilane was added to a mixed solution of ethanol and water (V:V=8:2) and stirred and dissolved to obtain a silane solution with a concentration of 5 wt%. The pH of the solution was adjusted to 5.0 with acetic acid, and the antibacterial cotton fibers were immersed in the solution and reacted at 60°C for 2 h. After the reaction, the fibers were taken out, washed with ethanol for 3 times and dried. Subsequently, the pretreated fibers were completely immersed in the zinc-tea polyphenol coordination compound sol, and were ultrasonically treated at a power of 40 kHz and 300 W for 30 min. After the immersion was completed, the fibers were taken out and evenly laid, and were dried in a 65°C air-drying oven for 4 h to obtain the double antibacterial fibers.

[0041] Step 5: The double modified antibacterial fiber was mixed with ordinary cotton fiber at a mass ratio of 1:1. After being fully opened by an opener, the mixture was formed into a web with a basis weight of 80 g / m2 by a wet laying process, with the concentration of the web slurry being controlled at 0.05%. The formed web was sent to a hydroentangling reinforcement device for positive and reverse hydroentanglement (water jet head aperture 0.12 mm, water pressure 120 bar, cloth surface speed 5 m / min). Subsequently, the hydroentangled cloth was sent to a cylinder dryer and dried at a temperature of 95°C until the moisture content was less than 5%, thereby obtaining the finished product of the cotton soft towel. 2

[0042] Example 5 A method for preparing a non-irritating cotton soft towel, comprising the following steps: Step 1: 100 g of pure cotton fiber was completely immersed in 1000 mL of an aqueous solution containing 8% (w / v) sodium hydroxide and 4% (w / v) polyethylene glycol-400, and swelled at room temperature for 1 h. Subsequently, the system was transferred to a three-necked flask equipped with a mechanical stirrer and a condenser reflux device, and heated to 60°C and kept at constant temperature. Under the condition of stirring rate 200 rpm, 10 g of allyl glycidyl ether was slowly added dropwise, and the reaction was continued at this temperature for 3 h. After the reaction was completed, the modified fiber was taken out, washed repeatedly to neutral with a large amount of deionized water under ultrasonic assistance, and finally placed in an 80°C air drying oven for full drying, to obtain the modified cotton fiber.

[0043] Step 2: 10 g of methacryloyloxyethyl trimethyl ammonium chloride, 0.3 g of potassium persulfate and 0.15 g of bisulfite were added to 800 mL of deionized water, stirred and dissolved to obtain a mixed solution. 100 g of the modified cotton fiber was completely immersed in the above mixed solution, and the pH value was adjusted to 5.5 with 0.1 mol / L hydrochloric acid solution, and slowly heated to 50°C and kept at constant temperature for 4 h under the atmosphere of continuous nitrogen protection. After the reaction was completed, the fiber was taken out, washed with hot water at 60°C first, and then washed with 50% (v / v) ethanol aqueous solution under ultrasonic assistance for 20 min to completely remove the unreacted monomers and homopolymers, and finally dried at 80°C to obtain the antibacterial cotton fiber.

[0044] Step 3: 2.50 g of zinc nitrate nonahydrate was dissolved in 400 mL of ethanol-water mixed solvent (V:V=1:1) with magnetic stirring until completely dissolved to obtain solution A. 1 g of tea polyphenol was dissolved in 100 mL of the same proportion of ethanol-water solvent to obtain solution B. Under vigorous stirring (500 rpm), solution B was slowly added to solution A using a constant pressure dropping funnel, and the reaction was continued at room temperature for 4 h. The solution gradually changed from colorless to dark brown clear liquid, and a zinc-tea polyphenol coordination compound sol was obtained.

[0045] ​Step 4: 3-aminopropyltriethoxysilane was added into a mixed solution of ethanol and water (V:V=8:2) and stirred to dissolve to obtain a silane solution with a concentration of 2wt%. The solution pH was adjusted to 4.5 with acetic acid, and the antibacterial cotton fibers were immersed in the solution and reacted at 60°C for 2h. After the reaction, the fibers were taken out, washed with ethanol for 3 times and dried. Subsequently, the pretreated fibers were completely immersed in the zinc-tea polyphenol complex sol, and ultrasonic treatment was performed at a power of 40kHz, 300W for 30min. After the immersion was completed, the fibers were taken out and evenly laid out, and dried in a 65°C air-drying oven for 4h to obtain the double antibacterial fibers.

[0046] Step 5: The double modified antibacterial fibers were mixed with ordinary cotton fibers at a mass ratio of 1:2. After being mixed by an opener, a wet-laid process was adopted to control the concentration of the web-forming slurry to be 0.05%, and a forming machine was used to form a web with a basis weight of 80g / m 2 The formed web was sent to a hydroentanglement reinforcement device for forward and reverse hydroentanglement (water jet head aperture 0.12mm, water pressure 120bar, cloth surface speed 5m / min). Subsequently, the hydroentangled cloth was sent to a cylinder dryer and dried at a temperature of 95°C until the water content was less than 5%, thereby obtaining the finished product cotton wipes.

[0047] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that steps 1 and 2 are omitted in the preparation process of the cotton wipes, i.e. the cotton fibers are not subjected to methacryloyloxyethyl trimethyl ammonium chloride grafting treatment.

[0048] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that steps 3 and 4 are omitted in the preparation process of the cotton wipes, i.e. the cotton fibers are not subjected to zinc-tea polyphenol complex treatment.

[0049] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that in step 4 of the preparation process of the cotton wipes, the antibacterial cotton fibers are not subjected to 3-aminopropyltriethoxysilane grafting treatment.

[0050] Performance test: 1. Antibacterial performance test: Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 6538) were selected as test strains, which are common pathogenic bacteria in the application scenario of cotton wipes. The cotton wipe samples were cut into 10mm×10mm test samples, which were sterilized at 121°C for 20min, and then 5mL of bacterial suspension with a concentration of (1.0±0.2)×10 6The bacterial suspension was cultured at 37°C with 150 rpm shaking for 24 h. After the end of the culture, the number of viable bacteria in the bacterial solution was determined by plate counting method, and the antibacterial rate was calculated (antibacterial rate = [(number of bacteria in the blank group - number of bacteria in the sample group) / number of bacteria in the blank group] x 100%) to obtain the initial antibacterial rate. The water washing antibacterial test was first carried out according to the standard water washing (washing temperature 30°C, using standard detergent) for 50 times according to the "GB / T 8629-2017 Household washing and drying procedures for testing textiles", and then the above-mentioned shaking method was repeated to test the antibacterial rate after washing. The test results are shown in Table 1.

[0051] 2. Skin irritation test: The test was carried out using a recombinant human epidermis model, the cotton soft towel sample was cut into 8mm x 8mm test sample, then immersed in sterile saline and attached to the surface of the model, and exposed in a 37°C, 5% CO2 incubator for 15 min. After the exposure was completed, the test sample was removed and the surface of the model was washed, and the culture was continued for 42 h, and then the MTT method was used to determine the cell viability of the model. The cell viability of the blank control group (treated with saline) was 100%, and the relative cell viability of the sample group was calculated; the relative cell viability ≥80% was determined as "no irritation", 60%-79% was "slight irritation", and <60% was "irritation". The test results are shown in Table 1.

[0052] Table 1 Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to some of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a non-irritating cotton soft towel, characterized in that, Includes the following steps: S1. Pure cotton fibers are soaked in an aqueous solution containing sodium hydroxide and polyethylene glycol for swelling treatment. Then, allyl glycidyl ether is added under stirring to react and introduce carbon-carbon double bonds on the surface of the cotton fibers. After the reaction is completed, the fibers are washed and dried to obtain modified cotton fibers. S2. The modified cotton fiber is immersed in deionized water containing methacryloyloxyethyltrimethylammonium chloride, potassium persulfate and sodium bisulfite, and the reaction is carried out under a nitrogen atmosphere. After the reaction is completed, it is washed with hot water and ethanol aqueous solution, and dried to obtain antibacterial cotton fiber. S3. Dissolve zinc nitrate in a mixed solvent of ethanol and water to obtain solution A, and dissolve tea polyphenols in a mixed solvent of ethanol and water to obtain solution B. Add solution B dropwise to solution A under stirring to react and form a zinc-tea polyphenol coordination compound sol. S4. Immerse the antibacterial cotton fiber in a zinc-tea polyphenol coordination compound sol, perform ultrasonic treatment, and then remove and dry to obtain double antibacterial fiber; S5. The double-modified antibacterial fiber is mixed with ordinary cotton fiber and formed into a fiber web through a wet web forming process. The fiber web is then reinforced by hydroentangling and dried to obtain a cotton towel.

2. The method for preparing a non-irritating cotton towel according to claim 1, characterized in that, In step S1, the amount of allyl glycidyl ether added is 10-15 wt% of the weight of pure cotton fiber.

3. The method for preparing a non-irritating cotton towel according to claim 1, characterized in that, In step S1, the reaction temperature is 60-65℃ and the reaction time is 3-5h.

4. The method for preparing a non-irritating cotton towel according to claim 1, characterized in that, In step S2, the mass ratio of the epoxy-loaded cotton fiber to methacryloyloxyethyltrimethylammonium chloride is 10:1 to 3.

5. The method for preparing a non-irritating cotton towel according to claim 1, characterized in that, In step S2, the reaction temperature is 50–55°C and the reaction time is 4–6 hours.

6. The method for preparing a non-irritating cotton soft towel according to claim 1, characterized in that, In step S3, the mass ratio of zinc nitrate to tea polyphenols is 5:2-3.

7. The method for preparing a non-irritating cotton towel according to claim 1, characterized in that, In step S4, the antibacterial cotton fibers undergo pretreatment before being immersed in the zinc-tea polyphenol coordination compound sol, including the following steps: 3-Aminopropyltriethoxysilane was added to a mixed solution of ethanol and water and stirred to dissolve, resulting in a 3-aminopropyltriethoxysilane solution. Antibacterial cotton fibers were then immersed in the 3-aminopropyltriethoxysilane solution, and the pH was adjusted to 4.5–5.

5. The mixture was heated to react, and after washing and drying, the final product was obtained.

8. The method for preparing a non-irritating cotton soft towel according to claim 7, characterized in that, The concentration of the 3-aminopropyltriethoxysilane solution is 2-5 wt%.

9. The method for preparing a non-irritating cotton soft towel according to claim 7, characterized in that, In step S5, the mass ratio of ordinary cotton fiber to double-modified antibacterial fiber is 2:1 to 2.

10. A non-irritating cotton towel, characterized in that, It is prepared by the method described in any one of claims 1 to 9 above.

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