Antibacterial layered composite elastic fabric and preparation method thereof

Abstract

The present invention relates to the technical field of layered materials, and specifically to an antibacterial layered composite elastic fabric and a preparation method thereof. The present invention overcomes the shortcomings of existing layered fabrics, such as poor antibacterial properties and poor elasticity. The present invention uses polytetramethylene ether glycol, diphenylmethane diisocyanate, and modified microcrystalline cellulose as raw materials to prepare modified spandex fiber yarn; uses terephthalic acid, ethylene glycol, 1,4-butanediol, isophthalic acid, and nano-silicon dioxide as raw materials to prepare modified polyester fiber yarn; the outer layer fabric is obtained by plying and weaving the modified polyester fiber yarn and the modified spandex fiber yarn; the outer layer fabric is subjected to pretreatment, impregnation, and heat treatment to obtain an outer layer finishing fabric; the inner layer fabric is subjected to impregnation and heat treatment to obtain an inner layer finishing fabric; the outer layer finishing fabric and the inner layer finishing fabric are bonded and compounded to obtain an antibacterial layered composite elastic fabric, which has strong antibacterial properties and strong elasticity and is suitable for the production of outdoor textiles.

Description

Technical Field

[0001] The invention relates to the technical field of layered materials, in particular to an antibacterial layered composite elastic fabric and a preparation method thereof. Background Art

[0002] In the textile industry, both single-layer and layered fabrics are widely used. Single-layer fabrics are commonly found in lightweight summer clothing, providing a refreshing experience thanks to their excellent breathability. For example, short-sleeved shirts made of ordinary cotton single-layer fabric are comfortable to wear in hot weather. Layered fabrics, on the other hand, are widely used in autumn and winter clothing, functional clothing, and household items. For example, some home clothes use a double-layer fabric structure. The outer layer is blended to ensure breathability, and the inner layer is brushed to form an air insulation layer, significantly improving the warmth effect. Compared with single-layer fabrics, layered fabrics have obvious advantages. They can realize multiple functional combinations. By compounding different material layers, they can also give the fabric additional properties such as antibacterial, windproof, and waterproof.

[0003] With the improvement of people's economy and quality of life, more and more people like outdoor sports, and the requirements for outdoor textile products are becoming increasingly stringent. Not only do they expect outdoor textiles to have basic warmth and breathability functions, but they also desire them to have good antibacterial properties to ensure health, and at the same time have high elasticity to meet the needs of daily activities and exercise. However, the current layered fabrics have many problems in terms of antibacterial and elasticity. In terms of antibacterial properties, ordinary fabric materials are easily eroded by microorganisms. Even if antibacterial agents are added, the antibacterial effect is often difficult to last due to uneven distribution and poor durability. Some antibacterial agents also pose health and environmental risks. In terms of elasticity, the differences in the material properties of each layer and the problems with the inter-layer bonding method result in inconsistent deformation of each layer during stretching, which is prone to delamination and breakage, and cannot meet the requirements of high elasticity and recovery for human movement.

[0004] Therefore, an antibacterial layered composite elastic fabric and a preparation method thereof are proposed. Summary of the Invention

[0005] The present invention aims to provide an antibacterial layered composite elastic fabric and a preparation method thereof. The present invention comprises a modified spandex fiber yarn prepared using polytetramethylene ether glycol, diphenylmethane diisocyanate, and modified microcrystalline cellulose as raw materials; a modified polyester fiber yarn prepared using terephthalic acid, ethylene glycol, 1,4-butanediol, isophthalic acid, and nano-silicon dioxide as raw materials; an outer fabric layer is obtained by plying and weaving the modified polyester fiber yarn with a modified spandex fiber yarn; the outer fabric layer is subjected to pretreatment, impregnation, and heat treatment to obtain an outer finished fabric layer; the inner fabric layer is subjected to impregnation and heat treatment to obtain an inner finished fabric layer; and the outer finished fabric layer and the inner finished fabric layer are laminated and composited to obtain an antibacterial layered composite elastic fabric having strong antibacterial properties and high elasticity, and being suitable for the production of outdoor textiles.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In one aspect, the present invention provides a method for preparing an antibacterial layered composite elastic fabric, which specifically comprises the following steps:

[0008] S1: plying and weaving a cotton fiber yarn and a modified spandex fiber yarn to obtain an inner layer fabric; plying and weaving a modified polyester fiber yarn and a modified spandex fiber yarn to obtain an outer layer fabric;

[0009] S2: pre-treating, impregnating, and heat-treating the outer layer fabric to obtain an outer layer finishing fabric; and impregnating and heat-treating the inner layer fabric to obtain an inner layer finishing fabric;

[0010] S3: laminating and compounding the outer finishing fabric and the inner finishing fabric to obtain an antibacterial layered composite elastic fabric;

[0011] Modified spandex fiber yarn was prepared using polytetramethylene ether glycol, diphenylmethane diisocyanate, and modified microcrystalline cellulose as raw materials; modified polyester fiber yarn was prepared using terephthalic acid, ethylene glycol, 1,4-butanediol, isophthalic acid, and nano-silica as raw materials; and modified microcrystalline cellulose was prepared using microcrystalline cellulose, silver nitrate, and polydimethyldiallylammonium chloride as raw materials.

[0012] Preferably, the preparation method of the modified spandex fiber yarn is as follows: polytetramethylene ether glycol is added to a reactor, and after vacuum dehydration, diphenylmethane diisocyanate and dibutyltin dilaurate are added at 55-65°C, and the reaction is carried out for 2 hours to generate a prepolymer; 1,4-butanediol is added to the prepolymer and the reaction is carried out for 2.5 hours to obtain a spandex copolymer; the spandex copolymer is dissolved in N,N-dimethylacetamide and then modified microcrystalline cellulose and an antioxidant are added, and the spinning solution is sheared and dispersed for 30 minutes to obtain a spinning solution, and the spinning solution is spun and twisted to obtain a modified spandex fiber yarn, wherein the spinning temperature is set to 240°C.

[0013] Preferably, the preparation method of modified microcrystalline cellulose is as follows: after dispersing microcrystalline cellulose in deionized water, silver nitrate is added and stirred for 30 minutes, glucose is subsequently added, the mixture is reacted at 85-95°C for 1 hour, centrifuged and dried to obtain silver-loaded microcrystalline cellulose; after dispersing silver-loaded microcrystalline cellulose in deionized water, sodium hydroxide is added and stirred for 30 minutes, modified polydimethyldiallylammonium chloride is added, the mixture is reacted at 70°C for 5 hours to obtain a reaction solution, the reaction solution is centrifuged, the precipitate is washed and dried to obtain modified microcrystalline cellulose.

[0014] Preferably, the preparation method of the modified polydimethyldiallyl ammonium chloride comprises: dissolving 3 parts of polydimethyldiallyl ammonium chloride in 50 parts of deionized water and then cooling the mixture to 5° C. to obtain a reaction solution; dropwise adding 5 parts of a 27-33% by mass aqueous solution of peracetic acid to the reaction solution; adding isopropyl alcohol for precipitation, filtering, washing, and drying the precipitate to obtain the modified polydimethyldiallyl ammonium chloride.

[0015] Preferably, the preparation method of the modified polyester fiber yarn is as follows: in a reactor, terephthalic acid, ethylene glycol, 1,4-butanediol, isophthalic acid, zinc acetate and antimony trioxide are added in sequence, and then pre-reacted at 150°C for 30 minutes, and then the temperature is raised to 240-260°C and reacted for 4 hours to obtain a reaction system; pretreated nano-silica and stearic acid are added to the reaction system, blended at a stirring speed of 300 rpm for 5 minutes, and then heated to 280°C and reacted for 2-2.5 hours to obtain a melt; the melt is extruded through a screw extruder, cooled, pelletized, and dried to obtain modified polyester chips; the modified polyester chips are heated and melted, and then spun and twisted to obtain modified polyester fiber yarn; the preparation method of pretreated nano-silica is as follows: nano-silica is dispersed in anhydrous ethanol, KH560 is added, stirred for reaction for 2 hours, filtered and dried after the reaction is completed, to obtain pretreated nano-silica.

[0016] Preferably, the preparation method of the outer layer finishing fabric is: pre-treating the outer layer fabric to obtain a pre-treated fabric, immersing the pre-treated fabric in a finishing liquid for 15 minutes, and then performing padding, drying, and baking to obtain the outer layer finishing fabric; the pre-treatment method is, by mass, adding 7-8 parts of KH550 and 6-8 parts of nano-silicon dioxide to 90 parts of anhydrous ethanol, ultrasonically stirring for 60 minutes to obtain a dispersion; immersing the outer layer fabric in the dispersion for 30 minutes, and then drying and heat-treating to obtain the pre-treated fabric.

[0017] Preferably, the preparation method of the inner layer finishing fabric is: immersing the inner layer fabric in the finishing liquid for 15 minutes, then performing a rolling and drying process and then baking to obtain the inner layer finishing fabric, wherein the baking temperature is 130-150°C and the time is 2 minutes.

[0018] Preferably, the finishing liquid is prepared by adding 150 parts by mass of a polyurethane elastomer aqueous dispersion to deionized water, stirring at 200 rpm for 10 minutes, and then sequentially adding 6-10 parts of polyhexamethylene biguanide, 3 parts of a melamine formaldehyde resin crosslinking agent, 8-10 parts of a modified waterproofing agent, 3 parts of an organosilicon emulsion softener, 0.7 parts of a sodium polyacrylate dispersant, and 0.45 parts of a fatty alcohol polyoxyethylene ether, stirring for 30 minutes, adding deionized water to adjust the total concentration to 20%, and then standing to defoam to obtain the finishing liquid.

[0019] Preferably, the preparation method of the modified waterproofing agent is as follows: 100 parts of polycaprolactone diol with a molecular weight of 1000-2000 and 30 parts of N-methylpyrrolidone are mixed and stirred to obtain a mixture; the mixture is cooled to 55-65°C, 40 parts of diphenylmethane diisocyanate are added to the mixture and reacted for 2 hours to obtain a prepolymer; the mixture is cooled to 50°C, 10 parts of 1,4-butanediol are added to the prepolymer, the reaction is continued for 2 hours, and then 0.5 parts of triethylamine are added, the reaction is stirred for 30 minutes, and the mixture is cooled to obtain the modified waterproofing agent.

[0020] On the other hand, the present invention provides an antibacterial layered composite elastic fabric, the antibacterial layered composite elastic fabric comprises an inner layer fabric and an outer layer fabric; the inner layer fabric comprises cotton fiber yarn and modified spandex fiber yarn; the outer layer fabric comprises modified polyester fiber yarn and modified spandex fiber yarn; by weight,

[0021] The raw materials of the modified spandex fiber yarn include: 90-110 parts of polytetramethylene ether glycol, 45-55 parts of diphenylmethane diisocyanate, 10-15 parts of 1,4-butanediol, and 8-10 parts of modified microcrystalline cellulose;

[0022] The raw materials of the modified polyester fiber yarn include: 90-110 parts of terephthalic acid, 45-55 parts of ethylene glycol, 13-17 parts of 1,4-butanediol, 4-6 parts of isophthalic acid, 4-6 parts of pretreated nano-silica, and 0.5 parts of stearic acid;

[0023] Modified microcrystalline cellulose raw materials include: microcrystalline cellulose, silver nitrate, polydimethyldiallylammonium chloride;

[0024] The pretreated nano-silicon dioxide raw materials include: 3 parts of nano-silicon dioxide and 1.5 parts of KH560.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. In the present invention, microcrystalline cellulose is used as a carrier, and its surface hydroxyl groups are utilized to adsorb silver ions and form nanosilver particles through in-situ reduction, thereby imparting contact antibacterial activity to the fiber; the epoxy groups of epoxy-modified polydimethyldiallyl ammonium chloride undergo a ring-opening reaction with the cellulose hydroxyl groups to form a covalent bond; at the same time, its amino groups react with the isocyanate groups of the polyurethane prepolymer to form a urea bond, thereby constructing a cellulose-polydimethyldiallyl ammonium chloride-polyurethane triple chemical bonding network, which not only stably loads nanosilver to inhibit washing loss, but also enhances the breaking strength through stress transfer between rigid cellulose and flexible polyurethane chains; during the spinning process, high-temperature solvent volatilization prompts the cellulose to be arranged in an orderly manner along the fiber axis to form a reinforced skeleton, while the cationic properties of polydimethyldiallyl ammonium chloride are electrostatically regulated to disperse the filler, ensuring the uniformity of the fiber elasticity, and ultimately achieving a synergistic improvement in antibacterial, mechanical and elastic properties.

[0027] 2. In the present invention, 1,4-butanediol is introduced as a flexible chain segment in the preparation of modified polyester fibers. Its long carbon chain reduces the intermolecular forces of polyester and enhances the chain segment's mobility. Simultaneously, the meta-substituted structure of isophthalic acid disrupts the rigid, ordered arrangement of terephthalic acid, inhibiting the formation of crystalline regions. These two factors synergistically reduce the material's rigidity and enhance its resilience. Furthermore, nanosilica forms covalent bonds with the polyester matrix via a silane coupling agent. Its rigid particles are dispersed within the low-crystallinity, flexible matrix. This enhances the fiber's mechanical properties by transferring stress and hindering crack propagation, ultimately achieving a synergistic increase in elastic and mechanical properties.

[0028] 3. In the present invention, during the pretreatment of the outer fabric, a silane coupling agent and nano-silica are co-deposited to construct a micro-nano rough structure, thereby reducing the surface energy and introducing amino active sites. The modified waterproofing agent copolymerizes the flexible chain segment of polycaprolactone diol with the rigid chain segment of isocyanate to construct a hydrophobic polyurethane network. The residual isocyanate groups at the ends react with the amino and hydroxyl groups on the surface of the pretreated fibers during high-temperature baking to form a chemically bonded interface, which not only gives the fabric a long-lasting water-repellent ability, but also enhances the bonding strength between fibers through covalent bond bridging.

[0029] 4. In the present invention, polyhexamethylene biguanide can destroy bacterial cell membranes and achieve high initial antibacterial efficiency in the early stage of fabric use; and after multiple washings, antibacterial components such as nanosilver fixed by chemical bonds in the spandex fiber are slowly released from the inside of the fiber to supplement the surface antibacterial activity, and the internal and external synergy achieves a multi-level long-term antibacterial effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of breaking strength and breaking elongation of Example 1, Example 6, Examples 8-10, and Comparative Examples 6-7 of the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See also Figure 1 The present invention provides an antibacterial layered composite elastic fabric and a preparation method thereof, and the technical solution is as follows:

[0033] Example 1

[0034] Preparation of modified polydimethyldiallylammonium chloride

[0035] 3 parts of high molecular weight polydimethyldiallyl ammonium chloride were dissolved in 50 parts of deionized water and then cooled to 5°C; 5 parts of a 30% by mass aqueous solution of peracetic acid were slowly added dropwise; isopropyl alcohol was added for precipitation, and after filtering, the precipitate was washed and dried to obtain modified polydimethyldiallyl ammonium chloride.

[0036] Preparation of modified microcrystalline cellulose

[0037] 10 parts of microcrystalline cellulose were dispersed in 100 parts of deionized water, stirred for 30 minutes, 0.5 parts of silver nitrate were added and stirred for 30 minutes, and then 1 part of glucose was added. After reacting at 85°C for 1 hour, the mixture was centrifuged and dried to obtain silver-loaded microcrystalline cellulose; silver-loaded microcrystalline cellulose was dispersed in 100 parts of deionized water, 0.5 parts of sodium hydroxide were added and stirred for 30 minutes; modified polydimethyldiallylammonium chloride was added, reacted at 70°C for 5 hours, centrifuged, washed and dried to obtain modified microcrystalline cellulose.

[0038] Preparation of modified spandex fiber yarn

[0039] 90 parts of polytetramethylene glycol with a molecular weight of 2000 were added to the reactor and vacuum dehydrated at 80°C for 2 hours; the temperature was lowered to 60°C, 40 parts of diphenylmethane diisocyanate and 0.1 parts of dibutyltin dilaurate catalyst were added, and the reaction was carried out under nitrogen protection for 2 hours to generate a prepolymer; 10 parts of 1,4-butanediol were added to the prepolymer and the reaction was continued for 3 hours to obtain a spandex copolymer; the polyurethane copolymer was dissolved in 485 parts of N,N-dimethylacetamide and then 10 parts of modified microcrystalline cellulose and an antioxidant (antioxidant Irganox) were added. 1010), the amount of antioxidant is 0.5% of the total mass of the spinning solution, and a high shear disperser is used to stir for 30 minutes to obtain a spinning solution. The spinning solution is spun and twisted at a spinning temperature of 245°C and a spinning speed of 750 m / min to obtain a modified spandex fiber yarn, wherein the twist of the modified spandex fiber yarn is 25 twists / 10 cm and the linear density is 35 dtex.

[0040] Preparation of modified polyester fiber yarn

[0041] Preparation of pretreated nano-silica: 4 parts of nano-silica were dispersed in anhydrous ethanol, and then 1 part of KH-560 was added. The mixture was stirred and reacted for 2 hours. After the reaction was completed, the mixture was filtered and dried to obtain pretreated nano-silica.

[0042] In a reactor, 90 parts of terephthalic acid, 45 parts of ethylene glycol, 17 parts of 1,4-butanediol, 4 parts of isophthalic acid, 0.4 parts of zinc acetate and 0.3 parts of antimony trioxide catalyst are added in sequence, and the mixture is reacted at 150°C for 30 minutes, and then the temperature is raised to 250°C for reaction for 4 hours to obtain a reaction system; 4 parts of pretreated nano-silica and 0.5 parts of stearic acid are added to the reaction system, and the mixture is blended at a stirring speed of 300 rpm for 5 minutes, and then the mixture is heated to 280°C and reacted for 2.5 hours to obtain a melt; the melt is extruded through a screw extruder, cooled, pelletized and dried to obtain modified polyester chips; the modified polyester chips are heated and melted at 285°C, and then spun and twisted at a spinning temperature of 280°C and a spinning speed of 800 m / min to obtain modified polyester fiber yarn, wherein the twist of the modified polyester fiber yarn is 30 twists / 10 cm and the linear density is 40 dtex.

[0043] Preparation of inner and outer fabrics

[0044] Inner fabric: The yarn count of modified spandex fiber yarn and cotton fiber yarn are both 50S in British standard; the mass ratio of modified spandex fiber yarn to cotton fiber yarn is 4:1; the gram weight of the inner fabric is 80g / m 2 .

[0045] Outer fabric: Modified spandex yarn with a British count of 50S, modified polyester yarn with a British count of 60S; the mass ratio of modified spandex yarn to cotton yarn is 1:1; the gram weight of the inner fabric is 100g / m 2 .

[0046] Preparation of finishing solution

[0047] 100 parts of polycaprolactone diol with a molecular weight of 1000 and 30 parts of N-methylpyrrolidone were mixed, heated to 90°C and stirred for 1 hour; the system was cooled to 60°C, 40 parts of diphenylmethane diisocyanate were added and reacted at 60°C for 2 hours to obtain a prepolymer, the system was cooled to 50°C, 10 parts of 1,4-butanediol were added dropwise, the reaction was continued at 50°C for 2 hours, and then 0.5 parts of triethylamine were added, the reaction was stirred for 30 minutes, and the mixture was cooled to obtain a modified waterproofing agent.

[0048] 150 parts of polyurethane elastomer aqueous dispersion (Covestro Bayhydrol UH2890) were added to deionized water, and the mixture was stirred at 200 rpm for 10 min. Then, 1 part of purified polyhexamethylene biguanide, 3 parts of melamine formaldehyde resin crosslinker (Yadina YDN598), 8 parts of modified waterproofing agent, 3 parts of silicone emulsion softener (Qimin Chemical Qiquan), 0.7 parts of sodium polyacrylate dispersant (BASF Dispex N40) and 0.45 parts of fatty alcohol polyoxyethylene ether penetrant were added in sequence, and the mixture was stirred for 30 min. Deionized water was added to adjust the total concentration to 20%, and the mixture was allowed to stand for defoaming to obtain a finishing solution.

[0049] Preparation of outer finishing fabrics

[0050] The outer layer fabric was pretreated to obtain a pretreated fabric. The pretreated fabric was immersed in a finishing solution at a bath ratio of 20:1. After immersion for 15 minutes, the fabric was padded, with a padding ratio of 70%. The fabric was then dried and baked at 80°C for 10 minutes and 120°C for 3 minutes to obtain the outer layer finished fabric. The pretreatment method was as follows: 7 parts KH550 and 6 parts nano-silica were added to 90 parts anhydrous ethanol and ultrasonically stirred for 60 minutes to obtain a dispersion. The outer layer fabric was immersed in the dispersion for 30 minutes, followed by drying and heat treatment to obtain the pretreated fabric.

[0051] Preparation of inner finishing fabrics

[0052] The inner layer fabric is immersed in the finishing liquid, with the bath ratio of the fabric to the finishing liquid being 20:1. After immersion for 15 minutes, it is then subjected to immersion and rolling, with a immersion and rolling rate of 60%. After drying, it is baked at a drying temperature of 80°C for 10 minutes; and a baking temperature of 130°C for 2 minutes to obtain the inner layer finished fabric.

[0053] The outer finishing fabric and the inner finishing fabric are laminated and aligned, and the inner fabric and the outer fabric are sewn together by a multi-layer fabric quilting machine using polyester sewing thread to obtain an antibacterial layered composite elastic fabric.

[0054] The differences between Example 2-11 and Example 1 are shown in Table 1.

[0055] Table 1 Parameters of Examples 1-11

[0056]

[0057] The difference between Example 12 and Example 10 is that when preparing the dispersion used for pretreatment of the outer fabric, the amount of KH550 used is 7.5 parts and the amount of nano-silica is 7 parts; when preparing the modified waterproofing agent, the molecular weight of the polycaprolactone diol when preparing the finishing liquid is 1500, and the reaction temperature when preparing the prepolymer is 60°C; when preparing the finishing liquid, the amount of modified waterproofing agent added is 9 parts.

[0058] The difference between Example 13 and Example 10 is that when preparing the dispersion used for pretreatment of the outer fabric, the amount of KH550 used is 8 parts and the amount of nano-silica is 8 parts; when preparing the modified waterproofing agent, the molecular weight of the polycaprolactone diol when preparing the finishing liquid is 2000, and the reaction temperature when preparing the prepolymer is 65°C; when preparing the finishing liquid, the amount of modified waterproofing agent added is 10 parts.

[0059] The difference between Example 14 and Example 10 is that when preparing the dispersion liquid used for pretreatment of the outer fabric, the amount of KH550 used is 7.5 parts and the amount of nano-silica is 7 parts; when preparing the modified waterproofing agent, the molecular weight of the polycaprolactone diol when preparing the finishing liquid is 1000, and the reaction temperature when preparing the prepolymer is 60°C; when preparing the finishing liquid, the amount of modified waterproofing agent added is 10 parts.

[0060] The difference between Example 15 and Example 14 is that the amount of polyhexamethylene biguanide added in the preparation of the finishing liquid is 8 parts.

[0061] The difference between Example 16 and Example 14 is that the amount of polyhexamethylene biguanide added in the preparation of the finishing liquid is 10 parts.

[0062] The difference between Example 17 and Example 16 is that different amounts of raw materials are used in the preparation of the modified spandex fiber yarn: 100 parts of polytetramethylene ether glycol, 50 parts of diphenylmethane diisocyanate, 13 parts of 1,4-butanediol, and 9 parts of modified microcrystalline cellulose;

[0063] The modified polyester fiber yarn was prepared with different amounts of raw materials: 100 parts of terephthalic acid, 50 parts of ethylene glycol, 21 parts of 1,4-butanediol, 5 parts of isophthalic acid, and 5 parts of pretreated nano-silica.

[0064] The difference between Example 18 and Example 16 is that the amounts of raw materials used in the preparation of the modified spandex fiber yarn are different: 110 parts of polytetramethylene ether glycol, 55 parts of diphenylmethane diisocyanate, 15 parts of 1,4-butanediol, and 10 parts of modified microcrystalline cellulose;

[0065] The modified polyester fiber yarn was prepared with different amounts of raw materials: 110 parts of terephthalic acid, 55 parts of ethylene glycol, 24 parts of 1,4-butanediol, 6 parts of isophthalic acid, and 6 parts of pretreated nano-silica.

[0066] The difference between Example 19 and Example 16 is that different amounts of raw materials are used in the preparation of the modified spandex fiber yarn: 100 parts of polytetramethylene ether glycol, 50 parts of diphenylmethane diisocyanate, 13 parts of 1,4-butanediol, and 9 parts of modified microcrystalline cellulose;

[0067] The modified polyester fiber yarn was prepared with different amounts of raw materials: 110 parts of terephthalic acid, 55 parts of ethylene glycol, 24 parts of 1,4-butanediol, 6 parts of isophthalic acid, and 6 parts of pretreated nano-silica.

[0068] The difference between Comparative Example 1 and Example 1 is that modified microcrystalline cellulose is not added during the preparation of the modified spandex fiber yarn.

[0069] The difference between Comparative Example 2 and Example 1 is that modified polydimethyldiallylammonium chloride is not added during the preparation of the modified microcrystalline cellulose.

[0070] The difference between Comparative Example 3 and Example 1 is that no silver loading treatment is performed during the preparation of the modified microcrystalline cellulose.

[0071] The difference between Comparative Example 4 and Example 1 is that 1,4-butanediol is not added during the preparation of the modified polyester fiber.

[0072] The difference between Comparative Example 5 and Example 1 is that isophthalic acid is not added during the preparation of the modified polyester fiber.

[0073] The difference between Comparative Example 6 and Example 1 is that no pretreated nano-silica is added during the preparation of the modified polyester fiber.

[0074] The difference between Comparative Example 7 and Example 1 is that the nano-silica is not pretreated during the preparation of the modified polyester fiber.

[0075] The difference between Comparative Example 8 and Example 1 is that the outer fabric is not pretreated.

[0076] The difference between Comparative Example 9 and Example 1 is that the baking temperature during the preparation of the inner layer finishing fabric and the outer layer finishing fabric is both 80°C.

[0077] The difference between Comparative Example 10 and Example 1 is that no modified waterproofing agent is added to the finishing liquid.

[0078] The difference between Comparative Example 11 and Example 1 is that, during the preparation of the finishing liquid, hexadecyltrimethylammonium chloride is used instead of polyhexamethylene biguanide and the added amount is the same.

[0079] The difference between Comparative Example 12 and Example 1 is that the molecular weight of the polyvinyl lactone diol in the preparation process of the modified waterproofing agent is 4000.

[0080] Test Example 1

[0081] Test objects: Examples 1-7, Comparative Examples 1-3, Comparative Example 9, Comparative Example 11, Examples 15-16.

[0082] Test Method: The antibacterial rate was determined according to GB / T 20944.3-2008, "Evaluation of the Antimicrobial Properties of Textiles - Part 3: Oscillation Method," using Escherichia coli as the bacterial species. The final test results are shown in Table 2.

[0083] Table 2 Antibacterial rate test results

[0084]

[0085] Comparative Example 1 did not add modified microcrystalline cellulose, resulting in the lack of a triple chemical bonding network (cellulose-polydimethyldiallyl ammonium chloride-polyurethane) in the spandex fiber. Nanosilver could not be stably loaded and relied solely on physical adsorption of surface polyhexamethylene biguanide. After washing, the antibacterial agent was lost and there was no sustained-release supplement, resulting in a decrease in antibacterial performance. Comparative Example 2 did not use modified polydimethyldiallyl ammonium chloride, resulting in only weak hydrogen bonding between microcrystalline cellulose and polyurethane. The lack of epoxy covalent bonds made nanosilver easily fall off, and the antibacterial activity decreased after washing. Comparative Example 3 did not use silver-loaded microcrystalline cellulose as a physical filler, lacking the contact antibacterial effect of nanosilver. After washing, the surface polyhexamethylene biguanide was lost and there was no inner layer supplement, resulting in a significant decrease in antibacterial performance. Comparative Example 9 was baked at low temperature, resulting in insufficient curing of the crosslinking agent. Polyhexamethylene biguanide adhered via hydrogen bonds. After washing, insufficient bonding force caused loss and subsequent antibacterial durability to deteriorate. Comparative Example 11: Hexadecyltrimethylammonium chloride and the built-in cationic components of the fiber have charge repulsion, uneven distribution, and hydrophobic adsorption is easily destroyed by water washing.

[0086] Test Example 2

[0087] Test objects: Example 1, Example 6, Examples 8-10, Comparative Examples 4-7.

[0088] Test method: Elastic recovery rate adopts FZ / T70006-2004 "Test method for elastic recovery of knitted fabrics"; breaking strength and breaking elongation adopt ISO9073-3-1989 "Textiles, nonwoven fabrics - Part 3: Determination of tensile strength and elongation". The final test results are shown in Table 3 and Figure 1 shown.

[0089] Table 3 Rebound elasticity and mechanical properties test results

[0090] serial number Elastic recovery rate (%) Example 1 70.5 Example 6 72.5 Example 8 73.3 Example 9 73.7 Example 10 74.1 Comparative Example 4 62.5 Comparative Example 5 68.1 Comparative Example 6 68.5 Comparative Example 7 68.8

[0091] Comparative Example 4 lacks the 1,4-butanediol flexible chain segment, which increases the rigidity of the polyester molecular chain. The expansion of the crystalline region restricts the movement of the chain segment, and the elastic recovery rate decreases. Comparative Example 5 lacks the meta-substitution of isophthalic acid, which leads to a highly ordered arrangement of terephthalic acid. The large-sized crystalline region restricts the movement of the chain segment, and the elastic recovery rate decreases. However, the effect of isophthalic acid is small, and it needs to cooperate with 1,4-butanediol to enhance the elastic recovery rate. Figure 1 As shown, the mechanical properties of the materials in Comparative Examples 6 and 7 were tested. In Comparative Example 6, the lack of pre-treated nano-silica resulted in a loss of filler, which enhances mechanical properties, reduced stress transfer efficiency, and decreased breaking strength. In Comparative Example 7, the surface hydroxyl groups of the unpre-treated nano-silica were weakly adsorbed to the polyester matrix, resulting in poor filler dispersion and deteriorated mechanical properties.

[0092] Test Example 3

[0093] Test objects: Example 1, Examples 12-14, Comparative Example 8, Comparative Example 10, Comparative Example 12.

[0094] Test Method: Waterproof performance was tested using the water-immersion method according to GB / T 4745-2012, Textiles — Testing and Evaluation of Waterproof Performance. The final test results are shown in Table 4.

[0095] Table 4 Waterproof performance test results

[0096] serial number Waterproof performance (level) Example 1 Level 5 Example 12 Level 5 Example 13 Level 5 Example 14 Level 5 Comparative Example 8 Level 3 Comparative Example 10 Level 3 Comparative Example 12 Level 3

[0097] Comparative Example 8 lacked pretreatment of the outer fabric layer, resulting in the loss of the micro-nano rough structure created by the co-deposition of the silane coupling agent and nano-silica. This resulted in no reduction in fiber surface energy and no amino active sites. The terminal isocyanate groups of the modified waterproofing agent, lacking the amino and hydroxyl groups present on the pretreated fiber surface, were unable to form a chemical bonding interface, resulting in attachment only through physical adsorption. This insufficient interfacial bonding during washing caused the waterproofing agent to fall off, significantly reducing its water repellency. Comparative Example 10 lacked a modified waterproofing agent, resulting in the failure to form a hydrophobic polyurethane network, allowing water molecules to directly penetrate the interstices between fibers. Comparative Example 12 employed high-molecular-weight polycaprolactone diol with insufficient crosslinking density, resulting in increased porosity in the hydrophobic network and an inability to tightly cover the fiber surface structure.

[0098] Test Example 4 Comprehensive Test

[0099] Test Subject: Examples 17-19

[0100] Test method: Refer to Test Examples 1-3. The final test results are shown in Table 5.

[0101] Table 5 Comprehensive performance test results

[0102]

[0103] By optimizing the various process parameters and component dosages, it can be seen that under the conditions of Example 19, the performance of the antibacterial layered composite elastic fabric finally prepared is the best. The present invention achieves a comprehensive improvement in antibacterial properties, mechanical properties, and functional durability through multi-scale structural design and chemical synergistic effects. First, using microcrystalline cellulose as a carrier, its surface hydroxyl groups are fixed by in-situ reduction of nanosilver particles, and with the help of epoxy-modified polydimethyldiallyl ammonium chloride, a triple chemical bonding network is constructed. This not only stabilizes the nanosilver through covalent bonds to inhibit washing loss, but also synergistically enhances the breaking strength through stress transfer between the rigid cellulose skeleton and the flexible polyurethane chain. Secondly, in the polyester molecular design, the 1,4-butanediol flexible chain segment reduces the intermolecular force, and the isophthalic acid destroys the rigid ordered arrangement to inhibit crystallization. The two synergistically improve the resilience; the silane-coupled nanosilica is bonded to the flexible matrix through covalent bonds, and the rigid particles hinder crack propagation, achieving a simultaneous enhancement of breaking strength and fatigue resistance. During the outer fabric pretreatment, silane coupling agents and nanosilica are co-deposited to create a micro-nano rough structure. Combined with the hydrophobic network of polycaprolactone diol / isocyanate copolymers, this chemically bonded interface imparts durable water repellency. The antimicrobial system utilizes a dual mechanism: polyhexamethylene biguanide initially disrupts bacterial membranes for rapid inhibition, while chemically bonded nanosilver is slowly released with washing to replenish its activity. This synergistic effect ensures long-lasting antimicrobial performance. Chemical bonding and microstructural control of each component achieve synergistic optimization of multiple properties.

[0104] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antibacterial layered composite elastic fabric, characterized by: The specific steps include: S1: Cotton fiber yarn and modified spandex fiber yarn are twisted and knitted to obtain an inner layer fabric; modified polyester fiber yarn and the modified spandex fiber yarn are twisted and knitted to obtain an outer layer fabric; S2: The outer layer fabric is pretreated, impregnated, and heat-treated to obtain an outer layer finishing fabric; the inner layer fabric is impregnated and heat-treated to obtain an inner layer finishing fabric; S3: The outer layer finishing fabric and the inner layer finishing fabric are laminated and compounded to obtain the antibacterial layered composite elastic fabric; Modified spandex fiber yarn was prepared using polytetramethylene ether glycol, diphenylmethane diisocyanate, and modified microcrystalline cellulose as raw materials; modified polyester fiber yarn was prepared using terephthalic acid, ethylene glycol, 1,4-butanediol, isophthalic acid, and nano-silica as raw materials; and modified microcrystalline cellulose was prepared using microcrystalline cellulose, silver nitrate, and polydimethyldiallylammonium chloride as raw materials.

2. The method for preparing an antibacterial layered composite elastic fabric according to claim 1, characterized in that: The preparation method of the modified spandex fiber yarn comprises the following steps: adding polytetramethylene ether glycol to a reaction kettle, vacuum dehydrating, adding diphenylmethane diisocyanate and dibutyltin dilaurate at 55-65° C., and reacting for 2 hours to generate a prepolymer; adding 1,4-butanediol to the prepolymer and reacting for 2.5 hours to obtain a spandex copolymer; dissolving the spandex copolymer in N,N-dimethylacetamide, adding the modified microcrystalline cellulose and an antioxidant, shearing and dispersing for 30 minutes to obtain a spinning solution, and spinning and twisting the spinning solution to obtain the modified spandex fiber yarn, wherein the spinning temperature is set at 240° C.

3. The method for preparing an antibacterial layered composite elastic fabric according to claim 1, characterized in that: The preparation method of modified microcrystalline cellulose comprises: dispersing the microcrystalline cellulose in deionized water, adding silver nitrate, and stirring for 30 minutes, then adding glucose, reacting at 85-95° C. for 1 hour, centrifuging, and drying to obtain silver-loaded microcrystalline cellulose; The silver-loaded microcrystalline cellulose was dispersed in deionized water, sodium hydroxide was added, and stirred for 30 minutes. Modified polydimethyldiallylammonium chloride was then added, and the mixture was reacted at 70° C. for 5 hours to obtain a reaction solution. The reaction solution was centrifuged, and the precipitate was washed and dried to obtain the modified microcrystalline cellulose.

4. The method for preparing an antibacterial layered composite elastic fabric according to claim 3, characterized in that: The modified polydimethyldiallyl ammonium chloride is prepared by dissolving 3 parts of polydimethyldiallyl ammonium chloride in 50 parts of deionized water and then cooling the mixture to 5° C. to obtain a reaction solution; dropwise adding 5 parts of a 27-33% by mass peracetic acid aqueous solution to the reaction solution; adding isopropyl alcohol for precipitation, filtering, washing, and drying the precipitate to obtain the modified polydimethyldiallyl ammonium chloride.

5. The method for preparing an antibacterial layered composite elastic fabric according to claim 1, characterized in that: The preparation method of the modified polyester fiber yarn is as follows: in a reactor, terephthalic acid, ethylene glycol, 1,4-butanediol, isophthalic acid, zinc acetate and antimony trioxide are added in sequence, and then pre-reacted at 150°C for 30 minutes, and then heated to 240-260°C for reaction for 4 hours to obtain a reaction system; pretreated nano-silica and stearic acid are added to the reaction system, blended at a stirring speed of 300 rpm for 5 minutes, and then heated to 280°C for reaction for 2-2.5 hours to obtain a melt; the melt is extruded through a screw extruder, cooled, pelletized and dried to obtain modified polyester chips; the modified polyester chips are heated and melted, and then spun and twisted to obtain the modified polyester fiber yarn; the preparation method of the pretreated nano-silica is as follows: nano-silica is dispersed in anhydrous ethanol, and then KH560 is added, stirred for reaction for 2 hours, filtered and dried after the reaction is completed to obtain the pretreated nano-silica.

6. The method for preparing an antibacterial layered composite elastic fabric according to claim 1, characterized in that: The preparation method of the outer layer finished fabric is as follows: pre-treating the outer layer fabric to obtain a pre-treated fabric, immersing the pre-treated fabric in a finishing liquid for 15 minutes, and then performing padding, drying, and baking to obtain the outer layer finished fabric; the pre-treatment method is as follows, by weight: adding 7-8 parts of KH550 and 6-8 parts of nano-silicon dioxide to 90 parts of anhydrous ethanol, and ultrasonically stirring for 60 minutes to obtain a dispersion; immersing the outer layer fabric in the dispersion for 30 minutes, and then drying and heat-treating to obtain the pre-treated fabric.

7. The method for preparing an antibacterial layered composite elastic fabric according to claim 1, characterized in that: The preparation method of the inner layer finishing fabric is: immersing the inner layer fabric in a finishing liquid for 15 minutes, then performing a padding and drying process and then baking the inner layer finishing fabric, wherein the baking temperature is 130-150° C. and the baking time is 2 minutes.

8. The method for preparing an antibacterial layered composite elastic fabric according to claim 7, characterized in that: The finishing liquid is prepared by adding 150 parts by mass of a polyurethane elastomer aqueous dispersion to deionized water, stirring at 200 rpm for 10 minutes, and then sequentially adding 6-10 parts of polyhexamethylene biguanide, 3 parts of a melamine formaldehyde resin crosslinking agent, 8-10 parts of a modified waterproofing agent, 3 parts of an organosilicon emulsion softener, 0.7 parts of a sodium polyacrylate dispersant, and 0.45 parts of a fatty alcohol polyoxyethylene ether, stirring for 30 minutes, adding deionized water to adjust the total concentration to 20%, and then standing to defoam to obtain the finishing liquid.

9. The method for preparing an antibacterial layered composite elastic fabric according to claim 8, characterized in that: The preparation method of the modified waterproofing agent comprises the following steps: mixing 100 parts of polycaprolactone diol with a molecular weight of 1000-2000 and 30 parts of N-methylpyrrolidone, by weight, and stirring to obtain a mixture; cooling the mixture to 55-65° C., adding 40 parts of diphenylmethane diisocyanate to the mixture and reacting for 2 hours to obtain a prepolymer; cooling the mixture to 50° C., adding 10 parts of 1,4-butanediol to the prepolymer, continuing the reaction for 2 hours, and then adding 0.5 parts of triethylamine, stirring the reaction for 30 minutes, and cooling to obtain the modified waterproofing agent.

10. An antibacterial layered composite elastic fabric, characterized by: The antibacterial layered composite elastic fabric is prepared by the preparation method of claim 1; the antibacterial layered composite elastic fabric comprises an inner layer fabric and an outer layer fabric; the inner layer fabric comprises cotton fiber yarn and modified spandex fiber yarn; the outer layer fabric comprises modified polyester fiber yarn and the modified spandex fiber yarn; in parts by mass, The raw materials of the modified spandex fiber yarn include: 90-110 parts of polytetramethylene ether glycol, 45-55 parts of diphenylmethane diisocyanate, 10-15 parts of 1,4-butanediol, and 8-10 parts of modified microcrystalline cellulose; The raw materials of the modified polyester fiber yarn include: 90-110 parts of terephthalic acid, 45-55 parts of ethylene glycol, 17-24 parts of 1,4-butanediol, 4-6 parts of isophthalic acid, 4-6 parts of pretreated nano-silica, and 0.5 parts of stearic acid; Modified microcrystalline cellulose raw materials include: microcrystalline cellulose, silver nitrate, polydimethyldiallylammonium chloride; The pretreated nano-silicon dioxide raw material comprises: 3 parts of nano-silicon dioxide and 1.5 parts of KH560.

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