Preparation method of antibacterial and anti-mite fabric for towel

Abstract

The invention discloses a preparation method of an antibacterial and anti-mite fabric for towels. The preparation method comprises the following steps: preparing a cationic antibacterial polymer solution; preparing modified kaolin loaded with citronellal; preparing a composite finishing liquid containing a titanium precursor, antibacterial macromolecules and loaded kaolin; preparing a seal liquid with an amphoteric structure and a hydrophobic chain segment; sequentially carrying out pretreatment, first-time dipping, second-time dipping, third-time dipping and last-time dipping on the cotton base cloth. Through a multi-step ordered impregnation process, a'cationic antibacterial polymer / photocatalyst / fiber active group 'ternary synergistic gradient composite structure is constructed on the surface of the fiber, and the obtained fabric has efficient and lasting antibacterial and anti-mite performance, excellent fastness to washing, good soft hand feeling and low skin irritation; the fabric is especially suitable for infants and household textiles with high sanitary requirements.

Description

Technical Field

[0001] This invention relates to a method for preparing an antibacterial and anti-mite fabric for towels, belonging to the field of textile fabric technology. Background Technology

[0002] Cotton towels are widely used in home and personal care due to their good absorbency and soft touch. However, their loose fiber structure and high water content make them a suitable environment for bacteria, fungi, and dust mites to thrive. Ordinary towels that are kept in damp conditions for a long time will quickly breed microorganisms that produce odors, leading to problems such as discoloration, odor, and even skin itching. This is especially harmful to infants and people with sensitive skin.

[0003] Currently, reactive dyeing and finishing or softening finishing formulations are mostly used to improve hand feel and moisture absorption. Some products impart limited antibacterial properties through simple quaternary ammonium salt antibacterial agents or nano-inorganic powders (such as zinc oxide and titanium dioxide). However, these single treatment methods generally suffer from problems such as functional dispersion, weak film bonding, and poor wash resistance. Conventional quaternary ammonium salt antibacterial agents rely on electrostatic adsorption on the fiber surface, and are easily dissolved or migrated after contact with water, making it difficult to maintain the exposure rate of active groups, resulting in a rapid decline in antibacterial effect. Inorganic powder modified fibers suffer from interparticle agglomeration and surface energy... Poor quality materials make it difficult to form a continuous and uniform protective layer on the fiber surface, limiting the antibacterial or anti-mite effects to localized areas and affecting the softness of the fabric. In addition, some studies have attempted to add natural anti-mite ingredients (such as citronellal and eucalyptus oil), but these small molecules are volatile and highly heat-sensitive, and are largely lost during the high-temperature setting and finishing stages of the preparation process, making it difficult to achieve a lasting effect. Common antibacterial and anti-mite films are mainly completed by single-bath impregnation or spraying, and the film layer only forms a physical adsorption bond with the cotton fibers. After repeated washing or rubbing, the film is easily peeled off, and its function is severely degraded.

[0004] Therefore, how to achieve a balance between high-efficiency antibacterial, anti-mite, and good washability, while controlling the irritation caused by the contact between the finishing agent and the skin, has become a long-standing technical challenge in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing an antibacterial and anti-mite fabric for towels, in order to solve the problem that existing fabrics lack the ability to synergistically inhibit bacteria, fungi and dust mites, and have poor long-term antibacterial and anti-mite effects, making it difficult to meet the dual needs of infants and people with sensitive skin for hygiene and comfort.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for preparing an antibacterial and anti-mite fabric for towels, characterized by comprising the following steps:

[0007] S1. Preparation of cationic antibacterial polymer solution: Diallyldimethylammonium chloride aqueous solution and 3-methacryloyloxypropyltrimethoxysilane were subjected to free radical polymerization reaction under nitrogen atmosphere and 65-75℃ in the presence of ammonium persulfate to obtain cationic antibacterial polymer solution.

[0008] S2. Preparation of citronellol-loaded kaolin: Kaolin was acid-activated using hydrochloric acid solution to obtain acid-activated kaolin; the acid-activated kaolin was dispersed and then silanized with dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride at 55-65℃ to obtain modified kaolin; the modified kaolin was dispersed and then citronellol was added, followed by vacuum adsorption to obtain citronellol-loaded kaolin;

[0009] S3. Preparation of composite finishing solution: In an ethanol / deionized water mixed system, tetraisopropoxytitanium is hydrolyzed and polycondensed under the catalysis of glacial acetic acid to form a precursor sol. After adding cationic antibacterial polymer aqueous solution and mixing, kaolin loaded with citronellol is added to form a composite sol. Then, 3-glycidyloxypropyltrimethoxysilane and ethylenediamine are introduced to obtain the composite finishing solution.

[0010] S4. Preparation of sealing solution: [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonylpropyl)ammonium hydroxide and glycidyl methacrylate are subjected to free radical polymerization under a nitrogen atmosphere and at 65-75℃, initiated by azobisisobutyronitrile. After the reaction, dimethyloctadecylamine is introduced and quaternization reaction is carried out at 55-65℃. Then, ethylenediamine is introduced and chain extension reaction is carried out at 35-45℃ to obtain the sealing solution.

[0011] S5. Base fabric pretreatment: The white combed cotton terry cloth is treated with a hot alkaline solution containing non-ionic penetrant and sodium carbonate, then rinsed until neutral and dried to obtain the pretreated base fabric.

[0012] S6. First impregnation treatment: The pretreated base fabric is impregnated in a solution containing 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, sodium carbonate and sodium chloride, and dried after padding to obtain a first impregnation treatment towel fabric;

[0013] S7. Second impregnation treatment: The towel fabric that has been impregnated once is impregnated in a solution containing 3-glycidyloxypropyltrimethoxysilane and glacial acetic acid, and then dried after squeezing to obtain the towel fabric that has been impregnated twice.

[0014] S8. Third impregnation treatment: The terry cloth that has undergone the second impregnation treatment is impregnated in a solution containing the composite finishing liquid, and then dried after squeezing to obtain the terry cloth that has undergone the third impregnation treatment.

[0015] S9. Final impregnation treatment: The terry cloth that has undergone three impregnation treatments is impregnated in a solution containing the sealing liquid and glacial acetic acid, then dried after rolling to obtain an antibacterial and anti-mite terry cloth.

[0016] In the aforementioned preparation method, the ratio of diallyl dimethyl ammonium chloride aqueous solution, 3-methacryloyloxypropyltrimethoxysilane, and ammonium persulfate in step S1 is 72-108g:16-24g:0.8-1.2g.

[0017] In the aforementioned preparation method, the ratio of hydrochloric acid solution to kaolin in step S2 is 32-48g:16-24g; the ratio of acid-activated kaolin to dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride is 8-12g:6.4-9.6g; and the ratio of modified kaolin to citronellol is 8-12g:6.4-9.6g.

[0018] In the aforementioned preparation method, the ratio of tetraisopropoxytitanium, glacial acetic acid, cationic antibacterial polymer aqueous solution, kaolin loaded with citronellol, 3-glycidyloxypropyltrimethoxysilane, and ethylenediamine in step S3 is as follows:

[0019] 32-48g:3.2-4.8g:48-72g:9.6-14.4g:9.6-14.4g:4.8-7.2g.

[0020] In the aforementioned preparation method, the ratio of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonylpropyl)ammonium hydroxide, glycidyl methacrylate, azobisisobutyronitrile, dimethyloctadecylamine, and ethylenediamine in step S4 is 22.4-33.6g:9.6-14.4g:1.6-2.4g:16-24g:8-12g.

[0021] In the aforementioned preparation method, the ratio of the amount of the white combed cotton terry cloth, nonionic penetrant, and sodium carbonate in step S5 is 1000g:2.4-3.6g:24-36g.

[0022] In the aforementioned preparation method, the ratio of the amount of 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, sodium carbonate, and sodium chloride in step S6 is 720-1080g:240-360g:240-360g; the impregnation time is 9-11min; the roll residue pressure is 2bar; and the roll residue rate is 80%.

[0023] In the aforementioned preparation method, the ratio of 3-glycidyloxypropyltrimethoxysilane to glacial acetic acid in step S7 is 240-360g:24-36g; the impregnation time is 14-16min; the roll-off pressure is 2bar; and the roll-off rate is 70%.

[0024] In the aforementioned preparation method, the ratio of deionized water to composite finishing solution in step S8 is 5:1; the impregnation time is 9-11 min; the roll-off pressure is 2 bar; and the roll-off rate is 75%.

[0025] In the aforementioned preparation method, the ratio of sealing liquid to deionized water in step S9 is 5:2; the impregnation time is 9-11 min; the roll-off pressure is 2 bar; and the roll-off rate is 70%.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] (1) The kaolin carrier after acid activation and quaternization modification of the present invention has excellent dispersibility and stability in the composite finishing solution. It can form a multi-point connection interface with antibacterial polymer and titanium dioxide precursor, enhance the chemical anchoring effect between the composite membrane and cotton fiber, thereby significantly improving the adhesion and wash fastness of the membrane layer, and improving the bonding strength and wash resistance.

[0028] (2) This invention encapsulates citronellal in the interlayer and cavity of modified kaolin using vacuum loading technology, which effectively solves the problems of easy volatility and thermal instability of natural small molecules, and realizes the long-term storage and slow release of anti-mite active ingredients, ensuring the continuous anti-mite effect of fabrics in long-term humid environments, and realizing the long-term controlled release of anti-mite ingredients.

[0029] (3) In this invention, 3-glycidyloxypropyltrimethoxysilane and ethylenediamine are introduced as crosslinking agents. During the high-temperature baking process, they undergo a condensation reaction with fibers and polymers to form a dense silicon-oxygen-nitrogen three-dimensional covalent network, which greatly improves the density, stability and washability of the finished film.

[0030] (4) The outer sealing liquid of this invention adopts an amphoteric polymer system containing sulfonic acid groups and hydrophobic segments to construct a flexible film layer with hydrophilic-hydrophobic balance on the fiber surface. This film layer can not only prevent the migration and loss of internal functional components, but also form a uniform hydration layer during use, significantly reducing the dryness and irritation of the skin caused by traditional quaternary ammonium salt finishing agents, and giving the fabric an excellent soft touch and skin-friendly properties.

[0031] (5) This invention uses a multi-step orderly impregnation process to assemble and chemically fix active components with different functions layer by layer on the fiber surface, forming a gradient composite structure of "inner layer anchoring - middle layer function - outer layer protection". This structure can maintain high antibacterial and anti-mite performance after multiple washes, while maintaining the original breathability and hand feel of the fabric.

[0032] (6) This invention makes systematic innovations from multiple dimensions such as carrier modification, component loading, interface crosslinking, surface softening and process timing, effectively overcoming the technical problems that are common in traditional antibacterial and anti-mite finishing, such as weak film bonding, poor functional durability, stiff hand feel and skin irritation. It provides high-hygiene-standard home textiles, especially towels for infants and sensitive skin. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0034] The sources or properties of the main raw materials used in the following embodiments and comparative examples of the present invention are as follows:

[0035] diallyl dimethyl ammonium chloride aqueous solution: solid content 65%, industrial grade;

[0036] Kaolin: Purchased from Sigma-Aldrich, part number 685445, with an average diameter of approximately 50 nm, a length of approximately 2 μm, and a specific surface area of ​​approximately 64 m². 2 / g;

[0037] Hydrochloric acid solution: 36% by mass, analytical grade;

[0038] Citronellol: A natural mite-removing ingredient with a purity of ≥98%;

[0039] Off-white combed cotton terry cloth: 400g / m² 2 ;

[0040] 3-Chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution: 65% by mass, industrial grade;

[0041] The silane coupling agents and monomers, such as 3-methacryloyloxypropyltrimethoxysilane, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, tetraisopropoxytitanium, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide, glycidyl methacrylate, and 3-glycidyloxypropyltrimethoxysilane, are all commercially available industrial or chemically pure products.

[0042] The equipment used includes conventional textile finishing equipment such as mechanical agitators, constant temperature oil baths, vacuum drying ovens, padding machines, and hot air setting and drying machines.

[0043] Embodiment 1 of the present invention:

[0044] A method for preparing an antibacterial and anti-mite fabric for towels, the specific steps of which are as follows:

[0045] (1) Preparation of cationic antibacterial polymer solution:

[0046] Take 320g of deionized water, add 72g of diallyl dimethyl ammonium chloride aqueous solution, 16g of 3-methacryloyloxypropyltrimethoxysilane, and 0.8g of ammonium persulfate, and then add 80g of deionized water. React under a nitrogen atmosphere at 65℃ with mechanical stirring for 4.5h. After the reaction is complete, concentrate the resulting solution under reduced pressure at 60℃ to a solid content of 25% to obtain a cationic antibacterial polymer solution for later use.

[0047] (2) Preparation of kaolin loaded with citronellol:

[0048] Add 160g of deionized water to a beaker, then add 16g of kaolin and stir to disperse. Slowly add 32g of hydrochloric acid solution and stir in a 75℃ water bath for 2 hours. After treatment, filter and wash the product with deionized water until the filtrate is neutral, then dry in an 80℃ oven for 4 hours to obtain acid-activated kaolin. Take 8g of acid-activated kaolin and redisperse it in a mixed solution of 120g anhydrous ethanol and 40g deionized water, and sonicate for 30 minutes. Add 6.4g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, adjust the pH of the system to 4.3-4.7 with glacial acetic acid, and stir at 55℃ for 3.5 hours. After the reaction, filter, wash twice with an ethanol / water mixture, and dry at 80℃ for 4 hours to obtain modified kaolin. 8g of modified kaolin was dispersed in 64g of anhydrous ethanol, and 6.4g of citronellol was added. The mixture was magnetically stirred at room temperature for 30min, then transferred to a vacuum drying oven, evacuated to -0.08MPa and maintained for 1h. After restoring to normal pressure, the mixture was allowed to stand for 1h. The resulting product was filtered and dried under reduced pressure to obtain citronellol-loaded kaolin.

[0049] (3) Preparation of composite finishing solution:

[0050] Add 120g of anhydrous ethanol and 60g of deionized water to a flask and stir until homogeneous under ice bath conditions. Slowly add 32g of tetraisopropoxytitanium over 30 min and continue stirring for another 30 min. Add 3.2g of glacial acetic acid and age at room temperature for 1.5 h to obtain a precursor sol. Add 48g of the cationic antibacterial polymer aqueous solution obtained in step (1) to the sol and continue stirring for 1 h. Add 9.6g of kaolin loaded with citronellol obtained in step (2), sonicate for 30 min, and stir for 1 h to obtain a composite sol. Then add 9.6g of 3-glycidyloxypropyltrimethoxysilane and 4.8g of ethylenediamine to the composite sol, stir for 30 min, and adjust the pH to 4.3-4.7 with glacial acetic acid to obtain a composite finishing solution.

[0051] (4) Preparation of sealing fluid:

[0052] 160 g of deionized water, 22.4 g of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide, and 9.6 g of glycidyl methacrylate were added to a beaker and stirred to dissolve. 1.6 g of azobisisobutyronitrile (AIBN) was added as an initiator, and polymerization was carried out in a nitrogen atmosphere at 65 °C in an oil bath for 5.5 h. After the reaction, the mixture was cooled to room temperature, and 16 g of dimethyloctadecylamine was added. Quaternization was carried out at 55 °C for 5.5 h. Then, 8 g of ethylenediamine was added, and chain extension was carried out at 35 °C for 3.5 h. After the reaction, the mixture was purified to obtain a sealing solution with a solid content of approximately 15%.

[0053] (5) Base fabric pretreatment:

[0054] Take 1000g of unbleached combed cotton terry cloth and place it in a dyeing machine. Add 12000g of deionized water, 2.4g of nonionic penetrant, and 24g of sodium carbonate, and treat at 90℃ for 25 minutes. After treatment, rinse thoroughly with clean water until neutral, and dry at 80℃ to obtain pretreated terry cloth for later use.

[0055] (6) First impregnation treatment (fiber cationization):

[0056] Add 12000g of deionized water, 720g of 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, 240g of sodium carbonate, and 240g of sodium chloride to an impregnation tank, dissolve them evenly, and maintain the liquid temperature at 25℃. Immerse the pretreated terry cloth in the tank for 9 minutes. Then, roll it under a pressure of 2 bar, controlling the roll residue to 80%. After rolling, first dry it in a 75℃ oven for 30 minutes, and then bake it in a 125℃ hot air setting machine for 3 minutes to obtain the first-impregnation treated terry cloth.

[0057] (7) Second impregnation treatment (surface silane activation):

[0058] Add 12000g deionized water, 240g 3-glycidyloxypropyltrimethoxysilane, and 24g glacial acetic acid to an impregnation tank and stir for 25 minutes for hydrolysis. Immerse the first-impregnated terry cloth in the tank for 14 minutes. Roll it under 2 bar pressure, with a roll-off rate of 70%. Then pre-dry it in 75℃ hot air for 5 minutes, and then bake it in a 135℃ hot air setting machine for 2 minutes to obtain the second-impregnated terry cloth.

[0059] (8) Third impregnation treatment (composite functional layer construction):

[0060] Add 12000g of deionized water and 2400g of the composite finishing solution prepared in step (3) to the impregnation tank and stir evenly. Immerse the terry cloth that has undergone secondary impregnation into the tank for 9 minutes. Roll it under a pressure of 2 bar, with a roll-off rate of 75%. Then pre-dry it in hot air at 75℃ for 5 minutes, and then transfer it to a hot air setting machine at 135℃ for 3 minutes. After 3 minutes of baking, transfer it to deionized water for 10 minutes, remove it and dry it to obtain the terry cloth that has undergone tertiary impregnation.

[0061] (9) Final impregnation treatment (sealing protection):

[0062] Add 12000g of deionized water and 480g of the sealing liquid prepared in step (4) to the impregnation tank, stir evenly, and adjust the pH to 5.8-6.2 with glacial acetic acid. Immerse the three-stage impregnation treatment towel fabric in the tank for 9 minutes. Roll it with a pressure of 2 bar, with a roll-off rate of 70%. Then pre-dry it at 65℃ for 5 minutes, and then bake it in a hot air setting machine at 125℃ for 2 minutes. After naturally cooling to room temperature, rinse with deionized water and dry to obtain the final antibacterial and anti-mite towel fabric.

[0063] Embodiment 2 of the present invention:

[0064] A method for preparing an antibacterial and anti-mite fabric for towels, the specific steps of which are as follows:

[0065] (1) Preparation of cationic antibacterial polymer solution:

[0066] Take 400g of deionized water, add 90g of diallyl dimethyl ammonium chloride aqueous solution, 20g of 3-methacryloxypropyltrimethoxysilane, and 1g of ammonium persulfate, and then add 100g of deionized water. React under a nitrogen atmosphere at 70℃ with mechanical stirring for 5 hours. After the reaction is complete, concentrate the resulting solution under reduced pressure at 60℃ until the solid content is 30%, obtaining a cationic antibacterial polymer solution.

[0067] (2) Preparation of kaolin loaded with citronellol:

[0068] Add 200g of deionized water to a beaker, add 20g of kaolin and stir to disperse. Then slowly add 40g of hydrochloric acid solution and stir in an 80℃ water bath for 2 hours. After treatment, filter and wash the product with deionized water until neutral, and dry at 80℃ for 4 hours to obtain acid-activated kaolin. Take 10g of acid-activated kaolin and redisperse it in a mixed solution of 150g anhydrous ethanol and 50g deionized water, and sonicate for 30 minutes. Add 8g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, adjust the pH to 4.3-4.7 with glacial acetic acid, and stir at 60℃ for 4 hours. After the reaction, filter, wash, and dry to obtain modified kaolin. 10g of modified kaolin was dispersed in 80g of anhydrous ethanol, and 8g of citronellol was added. After stirring at room temperature for 30min, it was treated under a vacuum of -0.08MPa for 1h. After standing, it was filtered and dried to obtain kaolin loaded with citronellol.

[0069] (3) Preparation of composite finishing solution:

[0070] Add 160g anhydrous ethanol and 80g deionized water to a flask and stir in an ice bath. Slowly add 40g tetraisopropoxytitanium dropwise over 35 min, and continue stirring for another 45 min. Add 4g glacial acetic acid and age at room temperature for 2 h to obtain the precursor sol. Add 60g cationic antibacterial polymer aqueous solution and stir for 1.5 h. Add 12g kaolin loaded with citronellol, sonicate for 30 min, and stir for 1 h to obtain the composite sol. Add 12g 3-glycidyloxypropyltrimethoxysilane and 6g ethylenediamine, stir for 45 min, and adjust the pH to 4.3-4.7 with glacial acetic acid to obtain the composite finishing solution.

[0071] (4) Preparation of sealing fluid:

[0072] In a beaker, 200 g of deionized water, 28 g of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propionic acid)ammonium hydroxide, and 12 g of glycidyl methacrylate were added and dissolved. Then, 2 g of azobisisobutyronitrile (AIBN) was added. Polymerization was carried out at 70 °C for 6 h under a nitrogen atmosphere. After cooling, 20 g of dimethyloctadecylamine was added, and the reaction was carried out at 60 °C for 6 h. Then, 10 g of ethylenediamine was added, and the reaction was carried out at 40 °C for 4 h. After purification, a sealing solution with a solid content of approximately 20% was obtained.

[0073] (5) Base fabric pretreatment:

[0074] Take 1000g of towel cloth, add 3g of non-ionic penetrant and 30g of sodium carbonate to 15000g of deionized water, treat at 95℃ for 30min, rinse until neutral, and then dry at 80℃.

[0075] (6) First impregnation treatment:

[0076] Add 900g of 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, 300g of sodium carbonate and 300g of sodium chloride to 15000g of deionized water. Immerse the pretreated fabric at 30℃ for 10min, roll it at 2bar (80% roll-off), dry it at 80℃ for 30min, and bake it at 130℃ for 3min.

[0077] (7) Second impregnation treatment:

[0078] Add 300g of 3-glycidyloxypropyltrimethoxysilane and 30g of glacial acetic acid to 15000g of deionized water. After hydrolysis for 30min, immerse the first-treated fabric for 15min, roll it at 2bar (70% roll-off), pre-dry at 80℃ for 5min, and bake at 140℃ for 2min.

[0079] (8) Third impregnation treatment:

[0080] Add 3000g of composite finishing solution to 15000g of deionized water, immerse the secondary treated fabric for 10min, roll it at 2bar (75% roll-off rate), pre-dry at 80℃ for 5min, bake at 140℃ for 3min, wash with water and dry.

[0081] (9) Final immersion treatment:

[0082] Add 600g of sealing solution to 15000g of deionized water, adjust the pH to 5.8-6.2 with glacial acetic acid, immerse the three-treatment fabric for 10min, roll it at 2bar (70% roll-off), pre-dry at 70℃ for 5min, bake at 130℃ for 2min, cool, wash with water, and dry to obtain the finished product.

[0083] Embodiment 3 of the present invention:

[0084] A method for preparing an antibacterial and anti-mite fabric for towels, the specific steps of which are as follows:

[0085] (1) Preparation of cationic antibacterial polymer solution:

[0086] Take 480g of deionized water, add 108g of diallyl dimethyl ammonium chloride aqueous solution, 24g of 3-methacryloxypropyltrimethoxysilane, and 1.2g of ammonium persulfate, and then add 120g of deionized water. React under a nitrogen atmosphere at 75℃ with mechanical stirring for 5.5h. After the reaction is complete, concentrate to a solid content of 35% to obtain a cationic antibacterial polymer solution.

[0087] (2) Preparation of kaolin loaded with citronellol:

[0088] Add 240g of deionized water to a beaker, then add 24g of kaolin and stir to disperse. Slowly add 48g of hydrochloric acid solution and treat in an 85℃ water bath with stirring for 2 hours. After treatment, washing, and drying, acid-activated kaolin is obtained. Take 12g of acid-activated kaolin and redisperse it in a mixed solution of 180g anhydrous ethanol and 60g deionized water, and ultrasonically disperse for 30 minutes. Add 9.6g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, adjust the pH to 4.3-4.7, and stir at 65℃ for 4.5 hours. After reaction, treat to obtain modified kaolin. Take 12g of modified kaolin and disperse it in 96g of anhydrous ethanol, add 9.6g of citronellol, stir at room temperature for 30 minutes, then treat under a vacuum of -0.08MPa for 1 hour. After standing, treat to obtain citronellol-loaded kaolin.

[0089] (3) Preparation of composite finishing solution:

[0090] Add 200g anhydrous ethanol and 100g deionized water to a flask and stir in an ice bath. Slowly add 48g tetraisopropoxytitanium dropwise over 40 min, and continue stirring for 60 min. Add 4.8g glacial acetic acid and age at room temperature for 2.5 h to obtain the precursor sol. Add 72g cationic antibacterial polymer aqueous solution and stir for 1.5 h. Add 14.4g kaolin loaded with citronellol, sonicate for 30 min, and stir for 1 h to obtain the composite sol. Add 14.4g 3-glycidyloxypropyltrimethoxysilane and 7.2g ethylenediamine, stir for 60 min, and adjust the pH to 4.3-4.7 to obtain the composite finishing solution.

[0091] (4) Preparation of sealing fluid:

[0092] In a beaker, 240 g of deionized water, 33.6 g of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propionic acid)ammonium hydroxide, and 14.4 g of glycidyl methacrylate were added and dissolved. Then, 2.4 g of azobisisobutyronitrile (AIBN) was added. Polymerization was carried out at 75 °C for 6.5 h under a nitrogen atmosphere. After cooling, 24 g of dimethyloctadecylamine was added, and the reaction was carried out at 65 °C for 6.5 h. Then, 12 g of ethylenediamine was added, and the reaction was carried out at 45 °C for 4.5 h. After purification, a sealing solution with a solid content of approximately 20% was obtained.

[0093] (5) Base fabric pretreatment:

[0094] Take 1000g of towel cloth, add 3.6g of nonionic penetrant and 36g of sodium carbonate to 18000g of deionized water, treat at 100℃ for 35min, rinse until neutral, and then dry at 80℃.

[0095] (6) First impregnation treatment:

[0096] Add 1080g of 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, 360g of sodium carbonate and 360g of sodium chloride to 18000g of deionized water. Immerse the pretreated fabric at 35℃ for 11min, roll it at 2bar (80% roll-off), dry it at 85℃ for 30min, and bake it at 135℃ for 3min.

[0097] (7) Second impregnation treatment:

[0098] Add 360g of 3-glycidyloxypropyltrimethoxysilane and 36g of glacial acetic acid to 18000g of deionized water. After hydrolysis for 35min, immerse the first-treated fabric for 16min, roll it at 2bar (70% roll-off), pre-dry at 85℃ for 5min, and bake at 145℃ for 2min.

[0099] (8) Third impregnation treatment:

[0100] Add 3600g of composite finishing solution to 18000g of deionized water, immerse the secondary treated fabric for 11min, roll it at 2bar (75% roll-off rate), pre-dry at 85℃ for 5min, bake at 145℃ for 3min, wash with water and dry.

[0101] (9) Final immersion treatment:

[0102] Add 720g of sealing solution to 18000g of deionized water, adjust the pH to 5.8-6.2 with glacial acetic acid, immerse the three-treatment fabric for 11min, roll it at 2bar (70% roll-off), pre-dry at 75℃ for 5min, bake at 135℃ for 2min, cool, wash with water, and dry to obtain the finished product.

[0103] Comparative Example 1: This comparative example is used to illustrate the effect of not modifying the kaolin carrier.

[0104] The only difference from Example 2 is that, in step (2), the acid-activated kaolin is not subjected to silanization modification. That is, the acid-activated kaolin is used directly as a carrier, skipping the step of adding dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride for reaction, and the subsequent citronellol loading is also omitted. In step (3), when preparing the composite finishing solution, an equal amount of acid-activated kaolin (12g) is used instead of "citronellol-loaded kaolin". The remaining preparation steps and parameters are exactly the same as in Example 2.

[0105] Comparative Example 2: This comparative example is used to illustrate the effect of citronellol being directly mixed without being loaded by a carrier.

[0106] The only difference from Example 2 is that, in step (2), the modified kaolin is not vacuum-loaded with citronellol. In step (3), when preparing the composite finishing solution, 12g of "citronellol-loaded kaolin" is replaced with a physical mixture of 6g modified kaolin and 6g citronellol (added together with the sol). The remaining preparation steps and parameters are exactly the same as in Example 2.

[0107] Comparative Example 3: This comparative example is used to illustrate the effect of omitting the crosslinking agent in the composite finishing solution.

[0108] The only difference from Example 2 is that 3-glycidyloxypropyltrimethoxysilane and ethylenediamine are not added when preparing the composite finishing solution in step (3). The remaining preparation steps and parameters are exactly the same as in Example 2.

[0109] Comparative Example 4: This comparative example is used to illustrate the effect of omitting the second impregnation treatment (surface silane activation).

[0110] The only difference from Example 2 is that step (7) is omitted, i.e., the second impregnation treatment is not performed. After completing the first impregnation treatment in step (6), the third impregnation treatment in step (8) is performed directly. The remaining preparation steps and parameters are exactly the same as in Example 2.

[0111] Comparative Example 5: This comparative example is used to illustrate the effect of omitting the final impregnation treatment (sealing protection).

[0112] The only difference from Example 2 is that step (9) is omitted, i.e., the final impregnation treatment is not performed. After completing the third impregnation treatment in step (8), the final fabric is considered to be obtained. The remaining preparation steps and parameters are exactly the same as in Example 2.

[0113] Comparative Example 6: This comparative example is used to illustrate the effect of changing the order of impregnation treatment.

[0114] The only difference from Example 2 is the order of steps (8) and (9). That is, the sealing liquid is applied first (original step 9), and then the composite finishing liquid is applied (original step 8). Specifically, after the first application in step (6) and the second application in step (7), the "final application" (using the sealing liquid) is applied first, followed by the "third application" (using the composite finishing liquid). The process parameters for both steps remain unchanged.

[0115] Performance Testing and Result Analysis: The towel fabrics obtained in Examples 1-3 and Comparative Examples 1-6 were subjected to performance tests. The test methods and standards are as follows:

[0116] Skin irritation and compatibility: The human patch method was used according to GB / T 16886.10-2017 "Biological evaluation of medical devices - Part 10: Irritation and skin sensitization test". Twenty volunteers had the sample applied to the inside of their arms for 24 hours. Skin reactions were observed and rated (0-4, with lower values ​​indicating less irritation) 72 hours after removal.

[0117] Antimicrobial properties: The tests were conducted according to GB / T 20944.3-2008 "Evaluation of antimicrobial properties of textiles - Part 3: Shaking method". The test strains were Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922). 3cm × 3cm samples were cut, sterilized, and then placed in a nutrient broth containing bacteria and shaken for 24 hours. The culture was then diluted, plates were counted, and the inhibition rate was calculated.

[0118] Anti-mite performance: The test was conducted according to the rearing-contact method in GB / T 24253-2009 "Evaluation of Anti-mite Performance of Textiles". House dust mites were used as the test subject and cultured at 25℃ and 75% relative humidity, with an inoculation density of 50 mites / cm³. 2 After 14 days of observation, the number of surviving mites was counted, and the mite-prevention inhibition rate was calculated.

[0119] Wash resistance: Simulated washing was conducted according to the washing conditions specified in GB / T 3921-2008 "Textiles - Tests for color fastness to soaping", with a set number of washes of 30. After each wash, the antibacterial rate and anti-mite inhibition rate against Escherichia coli were retested using the above method to examine functional durability.

[0120] The test results are shown in Table 1.

[0121] Table 1 Performance Test Results

[0122]

[0123]

[0124] Data Analysis:

[0125] 1. As can be seen from the data in Examples 1-3 in Table 1, the antibacterial rate and mite-inhibition rate of the obtained towel fabrics are significantly higher than 94%, and the retention rate remains stable at over 90% after 30 washes. This indicates that the functional finishing layers obtained in the three examples have good durability and stable performance, and do not cause significant skin irritation. In summary, the multi-level composite finishing structure formed by this invention achieves efficient functional superposition while maintaining the original softness and moisture absorption of the fabric, thus exhibiting high antibacterial properties, high mite resistance, and good wash stability, making it particularly suitable for home and infant textiles used in long-term humid environments.

[0126] 2. As can be seen from the data of Example 2 and Comparative Example 1 in Table 1, the modified kaolin and its multi-step treatment of acid activation-quaternization-citronellol loading play a key role in constructing the composite antibacterial network, which can significantly improve the fixation of active ingredients and antibacterial performance. This may be because the acid activation process increases the specific surface area and surface hydroxyl density of kaolin, allowing quaternary ammonium groups to be firmly bonded through silicon-oxygen bonds, thereby enhancing the binding strength between the carrier and the organic antibacterial agent and inhibiting the volatilization and migration of citronellol. At the same time, the modified kaolin also introduces hydrophobic alkyl segments, which improves the dispersion stability in the composite finishing liquid and forms a homogeneous film layer. In contrast, the surface of the unmodified carrier in Comparative Example 1 is a hydrophilic mineral layer, and the antibacterial molecules are easily adsorbed and desorbed, resulting in the loss of active ingredients. Therefore, the function is significantly reduced during use and washing.

[0127] 3. As can be seen from the data in Example 2 and Comparative Example 2 in Table 1, the modified kaolin loaded with citronellol not only improves the heat resistance and persistence of the active substances, but also avoids the loss of fragrance and surface aggregation caused by direct mixing, thus achieving a stable coupling of antibacterial and anti-mite functions. This may be because the physical mixing of modified kaolin and citronellol cannot form a stable carrier. Citronellol is prone to volatilization and migration during high-temperature baking and use, leading to a rapid decline in the anti-mite effect. However, by using vacuum loading, citronellol molecules are introduced into the inner cavity of kaolin nanotubes, forming a dual fixation structure of "physical encapsulation / chemical adsorption". It can be gradually released in a humid and hot environment and form a synergistic anti-mite effect with the cationic polymer in the substrate. Furthermore, the citronellol-loaded particles improve the viscosity and film-forming properties of the finishing liquid, making the finished layer more uniformly distributed.

[0128] 4. From the data of Example 2 and Comparative Example 3 in Table 1, it can be inferred that the addition of 3-glycidyloxypropyltrimethoxysilane and ethylenediamine, during high-temperature baking, undergoes a condensation reaction with the fiber and cationic polymer to generate a dense silicon-oxygen organic covalent network, thereby forming a chemical anchor between the composite finishing layer and the fiber interface, improving the stability and wash fastness of the film layer. When the crosslinking agent is omitted, the finishing components mainly rely on electrostatic adsorption and hydrogen bonding, which are easily migrated and detached when exposed to water, resulting in a significant decrease in function after washing.

[0129] 5. As can be seen from the data of Example 2 and Comparative Example 4 in Table 1, the pretreatment process of double activation-crosslinking significantly enhances the bonding force between the fiber and the functional layer, making the structure of the finishing layer more uniform and firm, thus exhibiting higher durability, antibacterial and anti-mite effects. This may be because the 3-glycidyloxypropyltrimethoxysilane activation process in the second impregnation treatment step plays an "interface bridging" role in the entire multilayer finishing system. This step forms abundant epoxy and hydroxyl active sites on the fiber surface, providing chemical bonding points for the TiO2 precursor and polymer chains in the subsequent composite sol, ensuring the continuity and density of the finishing film. When this step is missing, the adhesion between the subsequent composite finishing layer and the fiber is mainly physical adsorption, and the film layer is easy to fall off during use and washing.

[0130] 6. As can be seen from the data of Example 2 and Comparative Example 5 in Table 1, the sealing layer not only plays a protective and sustained-release role in this system, but also maintains the skin-friendly properties and functional stability of the fabric. This may be because the outer amphoteric polymer-hydrophobic quaternary ammonium network formed by the sealing liquid can form a uniform hydration layer on the fabric surface, allowing the outer antibacterial groups to be partially embedded in the flexible matrix. This provides bactericidal points in the dry state and isolates direct contact in the wet state, thereby effectively reducing skin irritation. In contrast, when this step is missing, the quaternary ammonium groups are exposed on the surface. The initial antibacterial properties are acceptable, but after repeated washing, the active groups are easily dissolved or migrated, causing a decline in performance. At the same time, excessive exposure of positive charges increases direct friction and irritation to the skin.

[0131] 7. As can be seen from the data of Example 2 and Comparative Example 6 in Table 1, there is a significant temporal synergistic effect between the stages of the multi-step impregnation process of the present invention. The reasonable processing order is crucial for constructing a stable multilayer functional membrane structure. This may be due to the spatial structure of the composite membrane caused by the process sequence. First, the TiO2-cationic polymer-kaolin system is cross-linked and cured on the fiber surface, and then a secondary network is formed by the outer sealing liquid to achieve a gradient structure of "rigid inside and flexible outside". This exposes the photocatalytic composite layer to the outside world while the sealing layer plays a buffering and protective role. In contrast, after the process is reversed, the sealing layer forms a dense membrane layer first, which hinders the deep binding of functional components. Moreover, the TiO2 precursor is confined to the surface and cannot be completely anchored on the active site, resulting in uneven membrane binding and easy detachment.

[0132] In summary, this invention successfully constructs a stable, efficient, durable, and skin-friendly multifunctional composite system through specific carrier modification, component loading, crosslinking design, interface activation, surface protection, and ordered processes, comprehensively solving many defects in traditional technologies.

[0133] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art to process parameters or additives using the technical principles and concepts disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing an antibacterial and anti-mite fabric for towels, characterized in that, Includes the following steps: S1. Preparation of cationic antibacterial polymer solution: Diallyldimethylammonium chloride aqueous solution and 3-methacryloyloxypropyltrimethoxysilane were subjected to free radical polymerization reaction under nitrogen atmosphere and 65-75℃ in the presence of ammonium persulfate to obtain cationic antibacterial polymer solution. S2. Preparation of citronellol-loaded kaolin: Kaolin was acid-activated using hydrochloric acid solution to obtain acid-activated kaolin; the acid-activated kaolin was dispersed and then silanized with dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride at 55-65℃ to obtain modified kaolin; Modified kaolin was dispersed and then citronellol was added. The kaolin loaded with citronellol was obtained by vacuum adsorption. S3. Preparation of composite finishing solution: In an ethanol / deionized water mixed system, tetraisopropoxytitanium is hydrolyzed and polycondensed under the catalysis of glacial acetic acid to form a precursor sol. After adding cationic antibacterial polymer aqueous solution and mixing, kaolin loaded with citronellol is added to form a composite sol. Then, 3-glycidyloxypropyltrimethoxysilane and ethylenediamine are introduced to obtain the composite finishing solution. S4. Preparation of sealing solution: [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonylpropyl)ammonium hydroxide and glycidyl methacrylate are subjected to free radical polymerization under a nitrogen atmosphere and at 65-75℃, initiated by azobisisobutyronitrile. After the reaction, dimethyloctadecylamine is introduced and quaternization reaction is carried out at 55-65℃. Then, ethylenediamine is introduced and chain extension reaction is carried out at 35-45℃ to obtain the sealing solution. S5. Base fabric pretreatment: The white combed cotton terry cloth is treated with a hot alkaline solution containing non-ionic penetrant and sodium carbonate, then rinsed until neutral and dried to obtain the pretreated base fabric. S6. First impregnation treatment: The pretreated base fabric is impregnated in a solution containing 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, sodium carbonate and sodium chloride, and dried after padding to obtain a first impregnation treatment towel fabric; S7. Second impregnation treatment: The towel fabric that has been impregnated once is impregnated in a solution containing 3-glycidyloxypropyltrimethoxysilane and glacial acetic acid, and then dried after squeezing to obtain the towel fabric that has been impregnated twice. S8. Third impregnation treatment: The terry cloth that has undergone the second impregnation treatment is impregnated in a solution containing the composite finishing liquid, and then dried after squeezing to obtain the terry cloth that has undergone the third impregnation treatment. S9. Final impregnation treatment: The terry cloth that has undergone three impregnation treatments is impregnated in a solution containing the sealing liquid and glacial acetic acid, then dried after rolling to obtain an antibacterial and anti-mite terry cloth.

2. The preparation method according to claim 1, characterized in that, The ratio of diallyl dimethyl ammonium chloride aqueous solution, 3-methacryloyloxypropyltrimethoxysilane, and ammonium persulfate in step S1 is as follows: 72-108g: 16-24g: 0.8-1.2g.

3. The preparation method according to claim 1, characterized in that, In step S2, the ratio of hydrochloric acid solution to kaolin is 32-48g:16-24g; the ratio of acid-activated kaolin to dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride is 8-12g:6.4-9.6g; and the ratio of modified kaolin to citronellol is 8-12g:6.4-9.6g.

4. The preparation method according to claim 1, characterized in that, In step S3, the ratio of tetraisopropoxytitanium, glacial acetic acid, cationic antibacterial polymer aqueous solution, kaolin loaded with citronellol, 3-glycidyloxypropyltrimethoxysilane, and ethylenediamine is 32-48g:3.2-4.8g:48-72g:9.6-14.4g:9.6-14.4g:4.8-7.2g.

5. The preparation method according to claim 1, characterized in that, The ratio of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonylpropyl)ammonium hydroxide, glycidyl methacrylate, azobisisobutyronitrile, dimethyloctadecylamine, and ethylenediamine in step S4 is 22.4-33.6g:9.6-14.4g:1.6-2.4g:16-24g:8-12g.

6. The preparation method according to claim 1, characterized in that, In step S5, the ratio of the amount of the white combed cotton terry cloth, the nonionic penetrant, and the sodium carbonate is 1000g: 2.4-3.6g: 24-36g.

7. The preparation method according to claim 1, characterized in that, In step S6, the ratio of the aqueous solution of 3-chloro-2-hydroxypropyltrimethylammonium chloride, sodium carbonate, and sodium chloride is 720-1080g:240-360g:240-360g; the impregnation time is 9-11min; the roll-off pressure is 2bar; and the roll-off rate is 80%.

8. The preparation method according to claim 1, characterized in that, In step S7, the ratio of 3-glycidyloxypropyltrimethoxysilane to glacial acetic acid is 240-360g:24-36g; the impregnation time is 14-16min; the roll-off pressure is 2bar; and the roll-off rate is 70%.

9. The preparation method according to claim 1, characterized in that, In step S8, the ratio of deionized water to composite finishing solution is 5:1; the impregnation time is 9-11 min; the roll-off pressure is 2 bar; and the roll-off rate is 75%.

10. The preparation method according to claim 1, characterized in that, In step S9, the ratio of sealing liquid to deionized water is 5:2; the impregnation time is 9-11 minutes; the roll-off pressure is 2 bar; and the roll-off rate is 70%.

Images