Skin-friendly elastic thermal insulation fabric and preparation method thereof

Abstract

The present application discloses a skin-friendly, stretchy, and thermal insulation fabric and a preparation method thereof, relating to the field of fabric manufacturing. The fabric of the present application is made of spandex core-spun yarn; the fabric is coated with an antibacterial layer, the raw materials of which include 1-3 wt% modified titanium dioxide-coated nanosilver and 4-6 wt% adhesive; the modified titanium dioxide-coated nanosilver is prepared by soaking the titanium dioxide-coated nanosilver in a 1-5 mmol cysteine solution for 3-5 hours. The skin-friendly, stretchy, and thermal insulation fabric of the present application has the advantages of high-efficiency antibacterial, long-lasting sustained release, a balance of durability and comfort, and a softness close to that of uncoated fabrics.

Description

Technical Field

[0001] The present application relates to the field of textile fabrics, and in particular to a skin-friendly, elastic, thermal insulation fabric and a preparation method thereof. Background Art

[0002] In the field of functional textile development, the synergistic effect of multi-component fiber composite systems has become a key path to achieve comprehensive performance optimization of materials. Taking the preparation of skin-friendly elastic thermal insulation fabrics as an example, the current mainstream technology generally adopts a composite material system of spandex and cotton fibers. Among them, spandex gives the material high resilience, and cotton fibers achieve thermal insulation through their porous structure and natural hygroscopicity. At the same time, their surface hydroxyl groups can enhance the skin-friendly touch of the fabric. However, this system has significant defects in biosafety. Although the inherent porous hydrophilicity of cotton fibers is conducive to moisture absorption and heat storage, they are also easy to become a carrier for microbial growth. The lack of effective antibacterial functional groups in its natural fiber structure leads to excessive total bacterial counts in long-term wearing environments, which may cause skin irritation reactions.

[0003] Existing antibacterial modification technologies often use post-finishing processes to load antibacterial agents onto the fabric surface. For example, patent CN109267232A discloses an antibacterial silk quilt coated with nanosilver in layers and its preparation method. It uses the contact sterilization mechanism of silver ions to achieve broad-spectrum antibacterial and has good antibacterial durability. However, the nanosilver applied by this method has a high surface energy, and the ionization process is accelerated in a hot and humid environment, resulting in a burst release of silver ions and a short silver ion release half-life. Although the initial antibacterial rate can reach over 99%, the antibacterial rate decreases rapidly after contact with the human body due to sweat accumulation or after washing, making it difficult to meet the market demand for long-term antibacterial. Summary of the Invention

[0004] The present application provides a skin-friendly elastic thermal insulation fabric and a preparation method thereof, which can obtain a fabric with high efficiency and long-lasting antibacterial effect, solving the problem of insufficient long-term antibacterial performance of nano-silver antibacterial fabric in a hot and humid aerobic environment.

[0005] In the first aspect, the present application provides a skin-friendly, elastic, and thermal insulation fabric, which is made of spandex core-spun yarn as raw material, wherein the spandex core-spun yarn has spandex fiber as the core layer, and cotton fiber is coated on the outside of the spandex fiber; the fabric is coated with an antibacterial layer, and the raw materials of the antibacterial layer include 1-3wt% modified titanium dioxide-coated nanosilver and 4-6wt% adhesive; the modified titanium dioxide-coated nanosilver is prepared by soaking titanium dioxide-coated nanosilver in a 1-5mmol cysteine solution for 3-5h.

[0006] In any of the above technical solutions, the proportion of titanium dioxide in the titanium dioxide-coated nanosilver is 15 to 20 wt%.

[0007] In any of the above technical solutions, the particle size of the titanium dioxide-coated nanosilver is 40 to 100 nm.

[0008] The present application achieves precise control of the silver ion release rate by constructing a composite structure of titanium dioxide coated nanosilver in the antibacterial layer. Titanium dioxide is coated on the surface of nanosilver in a chemically bonded form to form a physical barrier, which can effectively inhibit the direct contact between nanosilver and water molecules and oxygen in the environment, and inhibit the sudden release of silver ions. However, during the growth of the coating layer, due to deposition, temperature stress and other reasons, it is difficult for titanium dioxide to achieve complete coverage, resulting in the exposure of some nanosilver sites. These exposed sites become channels for the sudden release of silver ions in a hot and humid environment. To this end, the present application uses cysteine to selectively modify the defective sites, using the sulfhydryl group in the cysteine molecule to preferentially form covalent bonds or coordination bonds with silver atoms, and its carboxylic acid group self-assembles through intermolecular hydrogen bonds to form a dense monolayer film, effectively inhibiting the oxidation of exposed silver sites. And because the concentration and immersion time of the cysteine solution are controlled, the treatment process has little effect on the hydroxyl density on the titanium dioxide surface, ensuring the release rate of silver ions and the photocatalytic antibacterial activity of titanium dioxide. This dual protection mechanism significantly extends the silver ion release half-life compared to the unmodified sample.

[0009] It is worth noting that controlling the titanium dioxide content at 15-20wt% is the key to achieving a balance between high antibacterial efficiency and long-term effectiveness. When the titanium dioxide content is less than 15wt%, the continuity of the coating layer decreases, which is not conducive to controlling the release of silver ions in a hot and humid environment and reduces the long-term effectiveness; when the content exceeds 20wt%, titanium dioxide forms an overly thick shell, resulting in a reduction in the effective specific surface area of the nanosilver and a decrease in the initial antibacterial rate. In addition, moderately reducing the coating amount can construct a moderate defect structure on the surface of the nanosilver, which can not only form a protective layer by using the directional modification of cysteine, but also provide anchoring sites for the active groups in the adhesive. This improves the binding energy between the particles and the substrate. This chemical bonding effect can reduce the shedding rate of the modified particles under external forces such as friction, maintaining good antibacterial properties.

[0010] In any of the above technical solutions, the preparation method of the titanium dioxide-coated nanosilver is as follows:

[0011] A reducing agent is added to a silver ion aqueous solution, and a reduction reaction is carried out at 70-90° C. to obtain a silver sol; a titanium dioxide precursor and a dispersant are dropwise added to the silver sol, and the mixture is stirred and dispersed; an alkaline solution is dropwise added to adjust the pH to 10-11 to hydrolyze the titanium dioxide precursor, and then a hydrothermal reaction is carried out to obtain a titanium dioxide shell layer after the reaction is completed; the product is centrifuged, washed with water, and then calcined at 500-600° C. to obtain the product.

[0012] Exemplarily, the reducing agent is sodium borohydride or ascorbic acid.

[0013] Exemplarily, the titanium dioxide precursor is tetrabutyl titanate or titanium tetrachloride.

[0014] Exemplarily, the alkaline solution is aqueous ammonia or an aqueous solution of sodium hydroxide.

[0015] In any of the above technical solutions, the dispersant is polyvinyl pyrrolidone.

[0016] In any of the above technical solutions, the adhesive is a polyacrylate emulsion, and the comonomer of the polyacrylate emulsion contains 10 to 20 wt% of unsaturated dicarboxylic acid.

[0017] In any of the above technical solutions, the unsaturated dicarboxylic acid is selected from at least one of maleic acid, fumaric acid, and itaconic acid.

[0018] Exemplarily, the comonomer of the polyacrylate emulsion further includes one or more of styrene, methyl methacrylate, ethyl acrylate, hydroxyethyl acrylate, butyl acrylate, isooctyl methacrylate, and acrylic acid.

[0019] The use of a non-cross-linked polyacrylate emulsion helps maintain the softness and comfort of the fabric, and the antibacterial layer is less susceptible to cracking and peeling. Furthermore, the polyacrylate emulsion's primary component is nanoemulsion particles, which are less likely to coat the antibacterial particles. This helps optimize the release kinetics of the nanosilver and the catalytic activity of titanium dioxide, resulting in a more effective antibacterial effect. Using unsaturated dicarboxylic acids as copolymerization raw materials allows the introduction of abundant active carboxyl groups into the polyacrylate adhesive, which form strong chemical bonds with active groups such as amino and hydroxyl groups on the surface of titanium dioxide-coated nanosilver particles or cotton fibers. Furthermore, delayed addition of the dicarboxylic acid monomer during the synthesis process promotes the accumulation of carboxylic acid groups on the emulsion particle surface, creating a synergistic effect with the active groups of the cysteine-modified particles. This allows high particle anchoring to be achieved even when the adhesive dosage is reduced to 4-6 wt%, maintaining the fabric's moisture permeability and softness, and avoiding the obstruction of silver ion diffusion caused by excessive coating.

[0020] In any of the above technical solutions, the preparation method of the polyacrylate emulsion is as follows:

[0021] Adding comonomers other than unsaturated dicarboxylic acid to the emulsifier aqueous solution, stirring and dispersing to form an aqueous phase;

[0022] Add the initiator aqueous solution dropwise to the aqueous phase, raise the temperature to carry out copolymerization reaction, and react until the monomer conversion rate is ≥95%; then add the unsaturated dicarboxylic acid and continue the reaction. After the reaction is completed, cool down and adjust the pH to 8-9.

[0023] In any of the above technical solutions, the mass ratio of the spandex fiber to the cotton fiber is 5-20:80-95; the twist of the core-spun yarn is 600-1200 twists / m, the single yarn count of the cotton fiber is 40S-120S, and the spandex fiber specification is 20D-70D.

[0024] In a second aspect, the present application provides a method for preparing a skin-friendly elastic thermal insulation fabric, comprising the following operations:

[0025] According to the raw material ratio of any of the above-mentioned fabric antibacterial layers, modified titanium dioxide coated nanosilver, adhesive and dispersant are added to water, mixed and dispersed to form an antibacterial finishing liquid; the spandex core-spun yarn fabric is immersed in the antibacterial finishing liquid for double dipping and double rolling, and then dried and solidified to obtain the product.

[0026] In any of the above technical solutions, the bath ratio of the double dipping and double rolling is 1:10-20; the single dipping time is controlled at 1-3 minutes; the rolling rate is set at 70-85%; and the roller line pressure is set at 150-250 N / cm.

[0027] In any of the above technical solutions, the drying is divided into pre-baking and shaping, the pre-baking temperature is 80-100°C, and the heat treatment is 1-2 minutes; the shaping temperature is 130-150°C, and the heat treatment is 2-3 minutes.

[0028] In summary, this application has the following beneficial effects:

[0029] The present application constructs an antibacterial system with gradient protection by coating nanosilver with titanium dioxide and performing surface modification with cysteine. Among them, the titanium dioxide shell inhibits the oxidation of the silver body and optimizes the release kinetics of silver ions. The cysteine molecular film blocks the release of nanosilver from exposed sites and enhances the bonding strength between the particles, polyacrylate adhesive and the fabric. Under hot and humid conditions, the resulting fabric maintains a stable silver ion release rate and a long release half-life, and maintains a high antibacterial rate against bacteria after multiple washings. At the same time, the low dosage of polyacrylate adhesive and nanoemulsion particles give the antibacterial layer good flexibility, and the antibacterial layer is not easy to crack or fall off, thus achieving the unity of antibacterial durability, mechanical stability and wearing comfort. DETAILED DESCRIPTION

[0030] Preparation Example 1-1, a modified titanium dioxide-coated nanosilver, the preparation steps are as follows:

[0031] Preparation of silver sol: Dissolve 16.7 g of silver acetate in 200 mL of deionized water and heat to 75°C under nitrogen. Slowly add 100 mL of 20 wt% ascorbic acid solution as a reducing agent dropwise at a rate of 1 mL / min while stirring. Allow to react for 40 minutes to generate a silver sol.

[0032] Titanium dioxide coating: The silver sol was cooled to 30°C and 6 g of polyvinylpyrrolidone (molecular weight, 40,000) was added. 9.8 mL of tetrabutyl titanate was premixed with 60 mL of anhydrous ethanol and added dropwise to the sol at a rate of 2.5 mL / min. Sodium hydroxide solution (2 mol / L) was added dropwise in an ice bath to adjust the pH to 10.8. The mixture was magnetically stirred for 3 hours and then transferred to a reactor. A hydrothermal reaction was performed at 170°C for 15 hours. The precipitate was collected by centrifugation and washed with water until neutral. The precipitate was vacuum dried at 60°C for 24 hours. The temperature was then increased to 580°C under a nitrogen atmosphere at a rate of 8°C / min and calcined for 3 hours to obtain titanium dioxide-coated silver nanoparticles (TiO2 content 18 wt%, particle size 70 ± 10 nm).

[0033] Cysteine modification: 10 g of the titanium dioxide-coated nanosilver particles were dispersed in 500 mL of a 4 mmol / L cysteine solution and immersed under ultrasound at 50°C for 3 hours. The modified particles were then centrifuged and dried.

[0034] Preparation Example 1-2, a modified titanium dioxide-coated nanosilver, the preparation steps are as follows:

[0035] Preparation of silver sol: Dissolve 12.5 g of silver acetate in 150 mL of deionized water, heat to 70°C, and purge with nitrogen. Slowly add 80 mL of 15 wt% sodium borohydride solution as a reducing agent dropwise at a rate of 1 mL / min while stirring. Allow to react for 60 minutes to generate a silver sol.

[0036] Titanium dioxide coating: The silver sol was cooled to 30°C, and 6 g of polyvinylpyrrolidone (molecular weight, 40,000) was added. 5.2 mL of titanium tetrachloride was dissolved in 50 mL of 0.1 mol / L hydrochloric acid solution and added dropwise to the silver sol, maintaining a pH of 3.5. After hydrolysis at 75°C for 2 hours, sodium hydroxide solution (2 mol / L) was added dropwise to adjust the pH to 10.5. The solution was magnetically stirred for 3 hours and then transferred to a reactor. The reaction was hydrothermally reacted at 150°C for 18 hours. The precipitate was collected by centrifugation and washed with water until neutral. The precipitate was vacuum dried at 60°C for 24 hours. The temperature was then increased to 520°C under a nitrogen atmosphere at a rate of 10°C / min and calcined for 3 hours to obtain titanium dioxide-coated silver nanoparticles (TiO2 content 15 wt%, particle size 55 ± 8 nm).

[0037] Cysteine modification: 10 g of the titanium dioxide-coated nanosilver particles were dispersed in 500 mL of a 3 mmol / L cysteine solution and immersed under ultrasound at 50°C for 4 hours. The modified particles were then centrifuged and dried.

[0038] Preparation Example 1-3, a modified titanium dioxide-coated nanosilver, the preparation steps are as follows:

[0039] Preparation of silver sol: Dissolve 20 g of silver acetate in 250 mL of deionized water, heat to 85°C under nitrogen. Slowly add 120 mL of 25 wt% ascorbic acid solution as a reducing agent dropwise at a rate of 1 mL / min while stirring. Allow to react for 50 minutes to generate silver sol.

[0040] Titanium dioxide coating: The silver sol was cooled to 30°C and 6 g of polyvinylpyrrolidone (molecular weight, 50,000) was added. 12.5 mL of tetrabutyl titanate was premixed with 60 mL of anhydrous ethanol and added dropwise to the sol at a rate of 2.5 mL / min. Sodium hydroxide solution (2 mol / L) was added dropwise in an ice bath to adjust the pH to 11.2. The mixture was magnetically stirred for 3 hours and then transferred to a reactor. A hydrothermal reaction was performed at 190°C for 10 hours. The precipitate was collected by centrifugation and washed with water until neutral. The precipitate was vacuum dried at 60°C for 24 hours. The temperature was then increased to 600°C under a nitrogen atmosphere at a rate of 15°C / min and calcined for 4 hours to obtain titanium dioxide-coated silver nanoparticles (TiO2 content 20 wt%, particle size 85 ± 10 nm).

[0041] Cysteine modification: 10 g of the titanium dioxide-coated nanosilver particles were dispersed in 500 mL of a 1 mmol / L cysteine solution and immersed in an ultrasonic bath at 50°C for 5 hours. The modified particles were then centrifuged and dried.

[0042] Preparation Example 1-4, a modified titanium dioxide-coated nanosilver, differs from Preparation Example 1-1 in that the amount of tetrabutyl titanate used in the titanium dioxide coating step is reduced to 6.0 mL; the final TiO2 content is 12 wt% and the particle size is 65 ± 10 nm.

[0043] Preparation Example 1-5, a modified titanium dioxide-coated nanosilver, differs from Preparation Example 1-1 in that in the titanium dioxide coating step, the amount of tetrabutyl titanate is reduced to 14.0 mL; the final TiO2 content is 23 wt%, and the particle size is 75 ± 10 nm.

[0044] Preparation Example 1-6, a modified titanium dioxide-coated nanosilver, differs from Preparation Example 1-1 in that, in the cysteine modification step, the cysteine concentration is reduced to 0.5 mmol / L, and the immersion time is 3 hours.

[0045] Preparation Example 1-7, a modified titanium dioxide-coated nanosilver, differs from Preparation Example 1-1 in that, in the cysteine modification step, the cysteine concentration is increased to 8.5 mmol / L, and the immersion time is 3 hours.

[0046] Preparation Example 1-8, a titanium dioxide-coated nanosilver, differs from Preparation Example 1-1 in that titanium dioxide-coated nanosilver particles (TiO2 content 18wt%, particle size 70±10nm) are prepared in the titanium dioxide coating step, the particles and aminopropyltrimethoxysilane are added to ethanol at a mass ratio of 100:2, immersed under ultrasound at 50°C for 2 hours, and centrifuged and dried to obtain modified particles.

[0047] Preparation Example 2-1, a polyacrylate emulsion, was prepared according to the following steps:

[0048] Dissolve 2.5 g of sodium lauryl sulfate in 200 g of water to obtain an emulsifier solution for later use; dissolve 1.0 g of ammonium persulfate in 20 g of water and pre-emulsify to obtain an initiator solution for later use.

[0049] Add 60g of methyl methacrylate and 25g of butyl acrylate to the emulsifier solution and pre-emulsify at 300rpm for 30 minutes to form a stable aqueous phase. Heat the aqueous phase to 80°C and add the initiator solution dropwise at a rate of 0.5mL / min to initiate polymerization. Keep warm for 3 hours until the monomer conversion is ≥96%.

[0050] Dissolve 15g of maleic acid in 10mL of water and add dropwise to the reaction system at a rate of 0.5mL / min. Continue the reaction for 1 hour. Cool to 40°C, adjust the pH to 8.5 with aqueous ammonia, and filter to obtain an emulsion with a solid content of 38%.

[0051] Preparation Example 2-2, a polyacrylate emulsion, was prepared according to the following steps:

[0052] Dissolve 3.0 g of alkylphenol polyoxyethylene ether (OP-10) and 1.5 g of sodium lauryl sulfate in 200 g of water to obtain an emulsifier solution for later use; dissolve 1.2 g of potassium persulfate in 20 g of water and pre-emulsify to obtain an initiator solution for later use.

[0053] Add 65g of styrene and 25g of ethyl acrylate to the emulsifier solution and pre-emulsify at 300rpm for 45 minutes to form a stable aqueous phase. Heat the aqueous phase to 78°C and add the initiator solution dropwise at a rate of 0.5mL / min to initiate polymerization. Keep warm for 3 hours until the monomer conversion is ≥96%.

[0054] Dissolve 15g of itaconic acid in 10mL of water and add dropwise to the reaction system at a rate of 0.5mL / min. Continue the reaction for 1.5 hours. Cool to 35°C, adjust the pH to 8.5 with aqueous ammonia, and filter to obtain an emulsion with a solids content of 35% and a glass transition temperature (Tg) of -10°C.

[0055] Preparation Example 2-3, a polyacrylate emulsion, was prepared according to the following steps:

[0056] Dissolve 3.0 g of sodium lauryl sulfate in 250 g of water to obtain an emulsifier solution for later use; dissolve 0.8 g of ammonium persulfate in 15 g of water and pre-emulsify to obtain an initiator solution for later use.

[0057] Add 50g of methyl methacrylate and 30g of hydroxyethyl acrylate to the emulsifier solution and pre-emulsify at 300rpm for 60 minutes to form a stable aqueous phase. Heat the aqueous phase to 82°C and add the initiator solution dropwise at a rate of 1mL / min to initiate polymerization. Keep warm for 5 hours until the monomer conversion is ≥96%.

[0058] Dissolve 20 g of fumaric acid in 20 mL of water and add dropwise to the reaction system at a rate of 0.5 mL / min. Continue the reaction for 2 hours. Cool to 30°C, adjust the pH to 8.0 with aqueous ammonia, and filter to obtain an emulsion with a solid content of 40%.

[0059] Preparation Example 2-4 is a polyacrylate emulsion, which differs from Preparation Example 2-1 in that maleic acid is replaced by an equal amount of acrylic acid.

[0060] Preparation Example 2-5, a polyacrylate emulsion, differs from Preparation Example 2-1 in that maleic acid, methyl methacrylate, and butyl acrylate are added together to the emulsifier solution to form the aqueous phase. The steps are as follows:

[0061] Dissolve 2.5 g of sodium lauryl sulfate in 200 g of water to obtain an emulsifier solution for later use; dissolve 1.0 g of ammonium persulfate in 20 g of water and pre-emulsify to obtain an initiator solution for later use.

[0062] 60g of methyl methacrylate, 25g of butyl acrylate, and 15g of maleic acid were added to the emulsifier solution and pre-emulsified at 300 rpm for 30 minutes to form a stable aqueous phase. The aqueous phase was heated to 80°C, and the initiator solution was added dropwise at a rate of 0.5mL / min to initiate polymerization. The reaction was maintained at this temperature for 3 hours until the monomer conversion reached ≥96%. The product was cooled to 40°C, the pH adjusted to 8.5 with aqueous ammonia, and filtered to obtain an emulsion with a solids content of 38%.

[0063] Example 1, a skin-friendly elastic thermal insulation fabric, is prepared according to the following steps:

[0064] Prepare 150D spandex core-spun yarn with a twist of 900 twists / m. The core layer is 40D spandex and the outer layer is 80S long-staple cotton fiber. The ratio of spandex to cotton fiber is 12:88. Weave it into a plain fabric with a warp density of 120 strands / inch, a weft density of 80 strands / inch, and a gram weight of 145g / m2. 2 .

[0065] 20 g of the modified titanium dioxide-coated nanosilver prepared in Preparation Example 1-1, 50 g of the polyacrylate emulsion prepared in Preparation Example 2-1 and 5 g of polyvinyl pyrrolidone (K30) were mixed, deionized water was added to make up to 1 kg, and ultrasonic dispersion was performed at 40 kHz for 30 min to prepare an antibacterial finishing liquid.

[0066] The plain weave fabric was subjected to a double dip and double padding treatment at a bath ratio of 1:15. Each dip lasted 2 minutes, with a 10-second interval between dips to drain the liquid. The padding line pressure was 200 N / cm, and the padding rate was 80%. After padding, the fabric was pre-dried in a 90°C hot air circulation oven for 1.5 minutes, achieving a residual moisture content of 12%. The fabric was then set in a high-temperature stentering machine at 140°C for 2.5 minutes, resulting in an antibacterial layer with a thickness of 1.2 μm.

[0067] Example 2, a skin-friendly elastic thermal insulation fabric, is prepared according to the following steps:

[0068] Prepare 110D spandex core-spun yarn with a twist of 1200 twists / m. The core layer is 20D spandex and the outer layer is 120S long-staple cotton fiber. The ratio of spandex to cotton fiber is 8:92. Weave it into a plain fabric with a warp density of 150 strands / inch, a weft density of 100 strands / inch, and a gram weight of 130g / m2. 2 .

[0069] 12 g of the modified titanium dioxide-coated nanosilver prepared in Preparation Example 1-2, 40 g of the polyacrylate emulsion prepared in Preparation Example 2-2, and 3 g of polyvinyl pyrrolidone (K30) were mixed, deionized water was added to make up to 1 kg, and ultrasonic dispersion was performed at 40 kHz for 30 min to prepare an antibacterial finishing liquid.

[0070] The plain weave fabric was subjected to a double dip and double padding treatment at a bath ratio of 1:20. Each dip lasted 3 minutes, with a 10-second interval between dips to allow for drainage. The padding line pressure was 150 N / cm, and the padding rate was 70%. After padding, the fabric was pre-dried in an 80°C hot air circulation oven for 2 minutes, achieving a residual moisture content of 14%. The fabric was then set in a high-temperature stentering machine at 130°C for 3 minutes, resulting in an antibacterial layer with a thickness of 0.8 μm.

[0071] Example 3, a skin-friendly elastic thermal insulation fabric, is prepared according to the following steps:

[0072] Prepare 210D spandex core-spun yarn with a twist of 600 twists / m. The core layer is 70D spandex and the outer layer is 40S long-staple cotton fiber. The ratio of spandex to cotton fiber is 18:82. Weave it into a plain fabric with a warp density of 100 strands / inch, a weft density of 60 strands / inch, and a gram weight of 160g / m2. 2 .

[0073] 30 g of the modified titanium dioxide-coated nanosilver prepared in Example 1-3, 60 g of the polyacrylate emulsion prepared in Example 2-3 and 8 g of polyvinyl pyrrolidone (K30) were mixed, deionized water was added to make up to 1 kg, and ultrasonic dispersion was performed at 40 kHz for 30 min to prepare an antibacterial finishing liquid.

[0074] The plain weave fabric was subjected to a double dip and double padding treatment at a bath ratio of 1:10. Each dip lasted 1 minute, with a 10-second interval between dips to drain the liquid. The padding line pressure was 250 N / cm, and the padding rate was 80%. After padding, the fabric was pre-dried in a 100°C hot air circulation oven for 1 minute, achieving a residual moisture content of 12%. The fabric was then set in a high-temperature stentering machine at 150°C for 2 minutes, resulting in an antibacterial layer with a thickness of 1.5 μm.

[0075] Example 4 is a skin-friendly elastic thermal insulation fabric. The difference from Example 1 is that in the antibacterial finishing liquid raw material, the modified titanium dioxide-coated nanosilver of Preparation Example 1-1 is replaced by an equal amount of the modified titanium dioxide-coated nanosilver of Preparation Example 1-4.

[0076] Example 5, a skin-friendly elastic thermal insulation fabric, differs from Example 1 in that, in the antibacterial finishing liquid raw material, the modified titanium dioxide-coated nanosilver of Preparation Example 1-1 is replaced by an equal amount of the modified titanium dioxide-coated nanosilver of Preparation Example 1-5.

[0077] Example 6, a skin-friendly elastic thermal insulation fabric, differs from Example 1 in that the polyacrylate emulsion of Preparation Example 2-1 is replaced by an equal amount of the polyacrylate emulsion of Preparation Example 2-4 in the antibacterial finishing liquid raw material.

[0078] Example 7, a skin-friendly elastic thermal insulation fabric, differs from Example 1 in that, in the antibacterial finishing liquid raw material, the polyacrylate emulsion of Preparation Example 2-1 is replaced by an equal amount of the polyacrylate emulsion of Preparation Example 2-5.

[0079] Example 8 is a skin-friendly elastic thermal insulation fabric, which is different from Example 1 in that the amount of the polyacrylate emulsion in Preparation Example 2-1 used in the antibacterial finishing liquid raw materials is 80 g.

[0080] Comparative Example 1 is a skin-friendly elastic thermal insulation fabric, which differs from Example 1 in that, in the raw material of the antibacterial finishing liquid, the modified titanium dioxide-coated nanosilver of Preparation Example 1-1 is replaced by an equal amount of the modified titanium dioxide-coated nanosilver of Preparation Example 1-6.

[0081] Comparative Example 2 is a skin-friendly elastic thermal insulation fabric, which differs from Example 1 in that, in the antibacterial finishing liquid raw material, the modified titanium dioxide-coated nanosilver of Preparation Example 1-1 is replaced by an equal amount of the modified titanium dioxide-coated nanosilver of Preparation Example 1-7.

[0082] Comparative Example 3, a skin-friendly elastic thermal insulation fabric, is different from Example 1 in that, in the antibacterial finishing liquid raw material, the modified titanium dioxide-coated nanosilver of Preparation Example 1-1 is replaced by an equal amount of the modified titanium dioxide-coated nanosilver of Preparation Example 1-8.

[0083] Comparative Example 4 is a skin-friendly elastic thermal insulation fabric, which differs from Example 1 in that the modified titanium dioxide-coated nanosilver in Preparation Example 1-1 is replaced by an equal amount of nanosilver (particle size 60±10 nm) in the antibacterial finishing liquid raw material.

[0084] Performance testing

[0085] 1. Antibacterial performance test

[0086] The test was conducted in accordance with AATCC 147-2016, Determination of Antimicrobial Activity of Textiles: Parallel Streak Method.

[0087] Sample preparation: The antibacterial finished fabric samples (Examples 1-8, Comparative Examples 1-4) were cut into 2.5 cm × 2.5 cm specimens.

[0088] Test bacteria: Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 6538). Bacterial concentration 1×10 6 CFU / mL, inoculated on nutrient agar plates.

[0089] Test steps: Place the sample against the agar surface inoculated with the bacterial solution and incubate at 37°C for 18 hours. Measure the distance from the edge of the sample to the edge of the inhibition zone (unit: mm) and calculate the width of the inhibition zone: inhibition zone width = inhibition zone diameter - sample diameter. An inhibition zone width greater than 1 mm is considered effective antibacterial.

[0090] 2. Nanosilver release half-life

[0091] Sample preparation: The antibacterial layer was mechanically peeled off from the antibacterial treated fabric and ground into powder (particle size < 100 μm).

[0092] Test procedures: 0.5g of coating powder was weighed and immersed in 50mL of artificial sweat (prepared in strict accordance with ISO 105-E04 - Colorfastness to Perspiration Test Method) at 37°C with shaking at 120rpm to simulate the human body's heat and humidity. 1mL samples were taken at 0, 6, 12, 24, 48, and 72 hours. Particulate matter was removed by filtering through a 0.22µm nylon membrane. 1% nitric acid was added to the samples to stabilize the silver ions and prevent adsorption loss. Silver ion release kinetics were analyzed using an Agilent 7900 ICP-MS instrument. A first-order release model was fitted to calculate the silver ion release half-life.

[0093] 3. Antibacterial layer shedding rate test

[0094] Sample preparation: Cut the antibacterial treated fabric into samples of size 20cm×5cm, and sew the edges to prevent fiber shedding and interference.

[0095] Initial coating weight determination: Use a precision balance (0.1 mg accuracy) to weigh the total weight of the sample (including the base fabric and coating). Weigh an uncoated base fabric (same size) from the same batch. Calculate the net coating weight (Wcoating).

[0096] Friction test: Friction testing was performed in accordance with GB / T 3920-2008, using a Martindale abrasion tester. Rub the sample 3000 times according to the Lissajous figure at a pressure of 12 kPa. After friction, place the sample in a dust-free environment and gently sweep the surface debris onto a weighed filter paper (pre-weighed) with a soft brush. Use a vacuum cleaner (equipped with a 0.45 μm filter membrane) to collect any debris remaining inside the instrument. Weigh the collected debris and the filter paper together, and the net weight of the debris (Wshed) is calculated. Calculate the coating shedding rate:

[0097] Shedding rate (%) = Wshed / Wcoating×100.

[0098] 4. Fabric softness test

[0099] Sample preparation: Cut the antibacterial treated fabric into specimens of 20 cm × 25 cm in size, take 5 pieces (2.5 cm x 15 cm) in each direction of warp and weft, and equilibrate them in an environment of 20℃±2℃ and 65%±4%RH for 24 hours.

[0100] Test Method: Tested according to the AATCC 202:2014 Heart-Shaped Ring Method. A Handle-O-Meter (Model 3210) was used. The sample was folded in half to form a heart-shaped ring. Secured to a fixture, the sample was pushed through a narrow ring at a speed of 100 mm / min. The maximum resistance (cN) was recorded. Repeat this test five times, and the average value was used as the bending stiffness. Calculate the softness (higher values indicate softer fabrics):

[0101] Softness = 1 / bending stiffness × 1000.

[0102] 5. Moisture permeability test

[0103] Sample preparation: Cut the antibacterial treated fabric into a circular fabric with a diameter of 70 mm (including the antibacterial layer), seal the edges to prevent side leakage, and equilibrate at 20℃±2℃, 65%±4%RH for 24 hours.

[0104] Test method: Test according to the moisture absorption method in GB / T 12704-2019. Seal the sample in a moisture permeable cup (60mm inner diameter, 25mm depth) and fill the cup with 50g of anhydrous CaCl2. Place the sample in a constant temperature and humidity chamber. After 24 hours, weigh the total weight of the moisture permeable cup. Calculate moisture permeability:

[0105] WVT = (W2-W1) / At×24;

[0106] W1, W2: mass of the moisture permeable cup before and after the test (g);

[0107] A: moisture permeability of the sample (m 2 );

[0108] t: test time (h).

[0109] Table 1. Performance test results

[0110]

[0111] Analysis of test results:

[0112] (1) The width of the antibacterial zone of Examples 1-3 is >3.1mm (Escherichia coli) and >2.9mm (Staphylococcus aureus), which is slightly lower than that of Comparative Examples 1, 3, and 4. However, the silver ion release half-life of Examples 1-3 (54.1-61.3h) is much longer than that of Comparative Examples 1, 3, and 4 (20.2-35.3h). The reason may be that the titanium dioxide coating (15-20wt%) is combined with cysteine modification (3-5mmol), in which the titanium dioxide shell blocks the contact between water and oxygen, and the cysteine molecules seal the exposed silver sites, effectively inhibiting the burst release of silver ions, achieving sustained release, and forming a stable and durable antibacterial active layer. However, the incomplete coating structure of Comparative Examples 1, 3, and 4 produces burst release, resulting in high initial efficiency but poor long-term effectiveness. Although the half-life of Comparative Example 2 is longer than that of Examples 1-3, its initial antibacterial performance is poor. The reason may be that the cysteine concentration is too high, causing the titanium dioxide surface to assemble and form a film layer, which limits the photocatalytic activity of titanium dioxide and the effective release of nanosilver.

[0113] (2) The coating shedding rate of Examples 1-3 is less than 5%, which is lower than that of Examples 6 and 7 (11.72 and 15.90%). The reason for this may be that the unsaturated dicarboxylic acid and delayed acid addition (unsaturated dicarboxylic acid) process used in the polyacrylate emulsion allows the carboxylic acid to be enriched on the surface of the emulsion particles, which synergizes with the cysteine-modified particles and cotton fibers to enhance the bonding force between the particles, the coating and the fabric.

[0114] The shedding rates of Comparative Examples 3 and 4 (10.34% and 15.21%) were higher than those of Examples 1-3. This was because the exposed silver sites of the antibacterial particles did not assemble to form a dense cysteine monolayer, resulting in poor anchoring of the antibacterial particles with the adhesive and easy detachment due to friction.

[0115] (3) The bending stiffness of Examples 1-3 is 0.89-1.02 cN·cm2, which is close to that of uncoated fabrics (0.85 cN·cm 2 The reason for this is that the low amount of adhesive added and the bonding form of the latex particles prevent the antibacterial layer from hardening. Example 8 (high adhesive dosage) The bending stiffness is reduced to 0.76 cN·cm 2 , excessive adhesive causes the coating flexibility to decrease.

[0116] 5. Moisture permeability (GB / T12704-2019) 614

[0117] Examples 1-3: Moisture permeability 4600-5800 g / m2.24h, the porous structure of the coating (nanoemulsion particle size 100-200 nm) ensures breathability.

[0118] In summary, the skin-friendly stretch thermal insulation fabric of the present application has the advantages of high-efficiency antibacterial, long-lasting sustained release, balanced durability and comfort, high moisture permeability, and softness close to that of uncoated fabrics. Its comprehensive performance is significantly better than traditional nano-silver antibacterial technology and is suitable for the development of high-end functional textiles.

[0119] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A skin-friendly elastic thermal insulation fabric, characterized in that: The invention uses spandex core-spun yarn as raw material, wherein the spandex core-spun yarn has spandex fiber as a core layer and cotton fiber coated on the outside of the spandex fiber; the fabric is coated with an antibacterial layer, wherein the raw materials of the antibacterial layer include 1-3 wt% modified titanium dioxide-coated nanosilver and 4-6 wt% adhesive; the modified titanium dioxide-coated nanosilver is prepared by immersing the titanium dioxide-coated nanosilver in a 1-5 mmol / L cysteine solution for 3-5 hours; the preparation method of the titanium dioxide-coated nanosilver is as follows: adding a reducing agent to a silver ion aqueous solution, performing a reduction reaction at 70-90°C to obtain a silver sol; dripping a titanium dioxide precursor and a dispersant into the silver sol, stirring and dispersing, dripping an alkaline solution to adjust the pH to 10-11, hydrolyzing the titanium dioxide precursor, and then performing a hydrothermal reaction to obtain a titanium dioxide shell layer after the reaction is completed; and centrifuging and washing the product with water, and then calcining it at 500-600°C to obtain the product.

2. The fabric according to claim 1, characterized in that The titanium dioxide in the titanium dioxide-coated nanosilver accounts for 15 to 20 wt %.

3. The fabric according to claim 1, characterized in that The particle size of the titanium dioxide-coated nanosilver is 40-100 nm.

4. The fabric according to claim 1, characterized in that The dispersant is polyvinyl pyrrolidone.

5. The fabric according to claim 1, characterized in that The adhesive is polyacrylate emulsion, and the copolymerized monomer of the polyacrylate emulsion contains 10-20 wt% of unsaturated dicarboxylic acid.

6. The fabric according to claim 5, characterized in that: The unsaturated dicarboxylic acid is at least one selected from maleic acid, fumaric acid, and itaconic acid.

7. The fabric according to claim 5, characterized in that The preparation method of the polyacrylate emulsion is as follows: Adding comonomers other than unsaturated dicarboxylic acid to the emulsifier aqueous solution, stirring and dispersing to form an aqueous phase; Add the initiator aqueous solution dropwise to the aqueous phase, raise the temperature to carry out copolymerization reaction, and react until the monomer conversion rate is ≥95%; then add the unsaturated dicarboxylic acid and continue the reaction. After the reaction is completed, cool down and adjust the pH to 8-9.

8. The fabric according to claim 1, characterized in that The mass ratio of the spandex fiber to the cotton fiber is 5-20:80-95; the twist of the core-spun yarn is 600-1200 twists / m, the single yarn count of the cotton fiber is 40S-120S, and the specification of the spandex fiber is 20D-70D.

9. A method for preparing a skin-friendly elastic thermal insulation fabric, characterized in that: include: According to the raw material ratio of the antibacterial layer of the fabric described in any one of claims 1 to 8, modified titanium dioxide coated nanosilver, an adhesive and a dispersant are added to water, mixed and dispersed to form an antibacterial finishing liquid; the fabric is immersed in the antibacterial finishing liquid for two dipping and two rolling, and then dried and solidified to obtain the product.

Images