Moisture-permeable multilayer composite fabric and preparation method thereof

Abstract

The invention relates to the technical field of functional fabrics, particularly belongs to the technical field of patent classification number D01F6 / 00, and discloses a moisture-permeable multilayer composite fabric and a preparation method thereof. The moisture-permeable multi-layer composite fabric comprises an inner layer, a middle layer and an outer layer which are sequentially bonded and overlapped, the inner layer is a bamboo fiber fabric, the middle layer is a polypropylene fiber non-woven fabric, and the outer layer is a composite layer of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric. The preparation method comprises the steps that the two sides of the middle layer are coated with a binder, then the inner layer and the outer layer are overlaid on the upper portion and the lower portion of the middle layer respectively, then the inner layer and the outer layer are placed in laminating equipment to be subjected to hot pressing treatment, cooling is conducted, and the composite material is obtained. The multi-layer composite fabric provided by the invention has good moisture permeability and air permeability.

Description

Technical Field

[0001] The present invention relates to the technical field of functional fabrics, specifically to the technical field of patent classification number D01F6 / 00, and specifically to a moisture-permeable multi-layer composite fabric and a preparation method thereof. Background Art

[0002] In the field of textile materials, the performance of fabrics has always been the focus of research and application. With the improvement of people's quality of life and the growing demand for functional clothing and fabric products, higher requirements are placed on the moisture permeability of fabrics.

[0003] Traditional single-layer fabrics have a simple structure, a relatively convenient production process, and low cost. For example, common pure cotton single-layer fabrics have good skin-friendliness and are widely used in daily life. Ordinary T-shirts, shirts, etc. mostly use this material. However, due to its single structure, single-layer fabrics have obvious shortcomings in functionality. In terms of moisture permeability, pure cotton single-layer fabrics only rely on the gaps in the fibers themselves to achieve water vapor transmission. When the external humidity is high or the human body sweats a lot, its moisture permeability efficiency is low, and sweat cannot be discharged quickly, causing the wearer's skin surface to feel damp and sticky, seriously affecting the comfort of wearing. Moreover, single-layer fabrics lack sufficient protection and durability when facing complex usage environments, and it is difficult to meet the needs of special scenarios.

[0004] In order to make up for the shortcomings of single-layer fabrics, multi-layer fabrics came into being. Multi-layer fabrics are usually made by combining materials with different functions through a specific process in order to obtain the superposition of multiple properties. For example, some multi-layer fabrics are designed with a waterproof outer layer and a warm inner layer, which have been used in the field of outdoor clothing. However, in actual applications, the moisture permeability of most multi-layer fabrics is still unsatisfactory.

[0005] In addition, the difference in moisture permeability of different materials will also limit the overall moisture permeability performance of multi-layer fabrics. When the outer layer is made of a polymer film material with excellent waterproof performance but poor moisture permeability, even if the inner layer is made of a fabric with good moisture permeability, the water vapor is difficult to discharge smoothly due to the obstruction of the outer film, which seriously restricts the moisture permeability of the entire multi-layer fabric. This multi-layer fabric with poor moisture permeability cannot discharge sweat produced by the human body in time during sports, labor and other scenes, which will not only make the user feel uncomfortable, but also may cause skin diseases if in a humid environment for a long time, reducing the service life of the clothing and limiting its application in more fields.

[0006] In summary, both single-layer fabrics and existing multi-layer fabrics have the problem of poor moisture permeability, which largely limits the further development and application of fabrics in multiple fields such as clothing, medical treatment, and outdoor products. Therefore, the development of a multi-layer composite fabric with excellent moisture permeability and a preparation method thereof has important practical significance and market demand, which can effectively fill the gap in the existing technology and meet people's demand for high-performance fabrics. Summary of the invention

[0007] The purpose of the present invention is to provide a moisture permeable multi-layer composite fabric and a preparation method thereof, so as to solve the technical problem of poor moisture permeability of the fabric raised in the above background technology. The multi-layer composite fabric of the present invention has both good moisture permeability and air permeability.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A moisture-permeable multi-layer composite fabric comprises an inner layer, a middle layer and an outer layer which are bonded and stacked in sequence, wherein the inner layer is a bamboo fiber fabric, the middle layer is a polypropylene non-woven fabric, and the outer layer is a composite layer of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric.

[0010] The moisture-permeable multilayer composite fabric of the present invention has good moisture permeability, and the bamboo fiber fabric of the inner layer can quickly absorb the moisture emitted by the human body. In addition, the bamboo fiber has natural antibacterial and deodorizing properties, can effectively inhibit bacterial growth, reduce the generation of odor, and bring a fresh and comfortable feeling to the skin. At the same time, the bamboo fiber is soft in texture and delicate in touch. It can reduce friction when in contact with the skin, further improve the comfort of the inner layer, and allow the user to feel the soft wrapping like clouds during wearing, which greatly improves the pleasure and experience of wearing. The middle layer adopts polypropylene non-woven fabric, which has high strength and relatively tough texture, and can provide a good supporting structure for the entire composite fabric, so that it is not easy to deform during use and maintain a stable shape. In addition, the chemical stability of the polypropylene non-woven fabric is good, it is not easy to react with other substances, and it has a long service life and good durability. The polytetrafluoroethylene microporous membrane and the high-count cotton fiber fabric composite layer of the outer layer can effectively block the entry of external moisture while quickly discharging moisture, so that the human body remains dry and comfortable, and the overall structure is stable.

[0011] Preferably, the polypropylene non-woven fabric is made from modified polypropylene fibers.

[0012] Preferably, the method for preparing the modified polypropylene fiber comprises the following steps:

[0013] S1, adding nano-montmorillonite to deionized water, stirring to make the nano-montmorillonite preliminarily dispersed in the water to form a suspension, adding hexadecyltrimethylammonium bromide to the suspension, continuing to stir evenly, then heating to 60° C., stirring for 7 hours, centrifugally separating, washing and drying to obtain modified nano-montmorillonite;

[0014] S2, adding the modified nano-montmorillonite into anhydrous ethanol, dispersing it evenly by ultrasonic oscillation, then adding the polypropylene resin, stirring and mixing evenly, removing the anhydrous ethanol by a rotary evaporator to obtain a mixed masterbatch, adding the mixed masterbatch into a screw extruder for melt blending and granulation, and obtaining a nano-montmorillonite masterbatch;

[0015] S3, adding nano-montmorillonite masterbatch into the spinning machine barrel, using a metering pump to accurately control the melt extrusion amount, spinning at a spinning speed of 1200-1800 m / min to obtain primary fibers, stretching the primary fibers, and then performing heat setting treatment to obtain montmorillonite-doped polypropylene fibers;

[0016] S4, using a low-temperature plasma device to perform plasma treatment on the montmorillonite-doped polypropylene fiber, so as to introduce more oxygen-containing hydrophilic groups on the surface of the montmorillonite-doped polypropylene fiber, thereby obtaining a plasma-treated polypropylene fiber;

[0017] S5. Add acrylic acid into deionized water, heat and stir to dissolve, obtain acrylic acid solution, then add ammonium persulfate initiator, stir evenly, then immerse the plasma-treated polypropylene fiber in the above solution, keep warm for reaction, repeatedly wash the treated fiber with deionized water to remove the chemical reagents remaining on the surface, place in an oven and dry to constant weight, to obtain modified polypropylene fiber.

[0018] In the technical solution of the present invention, as mentioned above, the middle layer of the multi-layer composite fabric adopts polypropylene non-woven fabric, but the moisture conductivity of ordinary polypropylene fiber has certain limitations. Although it has the advantages of wicking effect and hydrophobicity that are conducive to moisture conduction, the moisture absorption capacity is limited and greatly affected by the environment, and it is impossible to meet the needs of high-performance breathable fabrics. The present invention adopts a series of methods to modify it. First, nano-montmorillonite is added to deionized water, reacted with hexadecyltrimethylammonium bromide to obtain modified nano-montmorillonite, and then dispersed in anhydrous ethanol and mixed with polypropylene resin to obtain nano-montmorillonite masterbatch. This is because nano-montmorillonite has a layered structure and a large specific surface area, can form microporous channels and increase the specific surface area in the polypropylene matrix, provide a path for water vapor transmission and increase the contact area with water vapor, and its characteristics of adsorbing and releasing water vapor also help to improve moisture conduction performance. Then the masterbatch is spun, stretched and heat-set to obtain montmorillonite-doped polypropylene fiber, which is then treated with a low-temperature plasma device to introduce oxygen-containing hydrophilic groups into the fiber surface, improve surface roughness and surface energy, and improve hydrophilicity and moisture conduction performance. Finally, the plasma-treated polypropylene fiber is immersed in an acrylic acid solution containing ammonium persulfate initiator for grafting modification. The hydrophilic groups such as the carboxyl group of the acrylic acid molecule further enhance the hydrophilicity of the fiber, forming a hydrophilic network structure to promote water vapor transmission. The grafted polymer layer improves the functionality and stability of the fiber, so that the modified polypropylene fiber can be better used in moisture-permeable multi-layer composite fabrics, thereby improving the moisture permeability of the overall fabric.

[0019] The present invention adds nano-montmorillonite to polypropylene fiber, which improves the moisture conductivity of polypropylene fiber. However, the further problem encountered is that the addition of nano-montmorillonite to polypropylene fiber causes the rheological property of the melt to change, resulting in a decrease in the mechanical strength of polypropylene, the occurrence of broken wires, and the deterioration of its spinnability. To solve this problem, the present invention modifies the nano-montmorillonite and inserts hexadecyltrimethylammonium bromide into the interlayer of montmorillonite through an ion exchange reaction. On the one hand, there is a van der Waals force between the long-chain alkyl (hexadecyl) in the hexadecyltrimethylammonium bromide and the molecular chain of the polypropylene fiber, and this intermolecular force can enhance the mutual attraction between the montmorillonite and the polypropylene fiber; on the other hand, the ion exchange reaction changes the charge distribution between the montmorillonite layers, and generates an electrostatic interaction with the polar groups that may exist in the polypropylene fiber, further strengthening the combination of the two. Through the synergistic effect of these forces, the comprehensive bonding strength between montmorillonite and polypropylene fiber is significantly improved, effectively avoiding the decrease in the mechanical strength of polypropylene fiber caused by the addition of montmorillonite, and ensuring that while using nano-montmorillonite and acrylic acid to improve the moisture conductivity of polypropylene fiber, the good performance of polypropylene fiber in other aspects such as mechanical strength is maintained.

[0020] Preferably, in step S1, the mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.3-0.5.

[0021] In the technical solution of the present invention, in order to avoid the negative impact of nano-montmorillonite on the mechanical properties of polypropylene fiber, a sufficient amount of hexadecyl trimethyl ammonium bromide must be intercalated in the nano-montmorillonite. When the mass ratio of nano-montmorillonite to hexadecyl trimethyl ammonium bromide is controlled by the present invention to be less than 1:0.3, the hexadecyl trimethyl ammonium bromide intercalated nano-montmorillonite plays a significant role in improving the mechanical strength of polypropylene fiber. However, the team of the present invention unexpectedly found that the air permeability of non-woven fabrics made of some polypropylene fibers has dropped significantly, which in turn leads to a decrease in the air permeability of multi-layer fabrics. After in-depth research, it was found that this problem has an important influence on the amount of hexadecyl trimethyl ammonium bromide intercalated in the nano-montmorillonite. When an excessive amount of hexadecyl trimethyl ammonium bromide must be intercalated in the nano-montmorillonite, the hexadecyl trimethyl ammonium bromide is filled in the internal pores and molecular chains of the polypropylene fiber, blocking the gas channel, significantly reducing the air permeability of the fiber, and affecting the comfort of use. Therefore, the present invention also strictly controls the mass ratio of nano-montmorillonite to hexadecyl trimethyl ammonium bromide to be greater than 1:0.5.

[0022] Preferably, in step S3, the spinning temperature is controlled at 170-180°C.

[0023] Preferably, in step S5, the insulation reaction temperature is 65-70° C., and the insulation reaction is carried out for 2-3 hours.

[0024] Preferably, the method for preparing the composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric comprises the following steps:

[0025] The polytetrafluoroethylene microporous membrane is subjected to plasma treatment to increase its surface activity to obtain a pretreated polytetrafluoroethylene microporous membrane, an adhesive is coated on the surface of the pretreated polytetrafluoroethylene microporous membrane, a high-count cotton fiber fabric is covered on the pretreated polytetrafluoroethylene microporous membrane to make the two closely fit, and hot pressing is performed to shape the membrane, and the membrane is cooled to obtain the membrane.

[0026] The outer layer of the multi-layer breathable fabric of the present invention is a composite of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric. The polytetrafluoroethylene microporous membrane is first subjected to plasma treatment to increase its surface activity, so that it can be better combined with a binder, so that the binder can be more evenly coated on its surface. The high-count cotton fiber fabric is covered and tightly fitted, and then hot-pressed to ensure that the connection between the two is firm and tight. The hot-pressing and shaping process can make the structure of the composite layer more stable. After cooling, the obtained composite layer has good integrity and stability, and can give full play to the excellent properties of the polytetrafluoroethylene microporous membrane (such as breathability, waterproofness, etc.) and the softness and comfort of the high-count cotton fiber fabric, so that the composite layer can show excellent comprehensive performance in practical applications.

[0027] Preferably, the pore size of the polytetrafluoroethylene microporous membrane is 0.1-0.5 μm and the thickness is 0.05-0.1 mm.

[0028] A method for preparing a moisture permeable multi-layer composite fabric comprises the following steps:

[0029] The adhesive is applied to both sides of the middle layer, and then the inner layer and the outer layer are respectively stacked on the upper and lower sides of the middle layer, and then placed in a laminating device for heat pressing treatment, and after cooling, the product is obtained.

[0030] Preferably, the adhesive is a polyurethane adhesive.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. Multi-layer composite structure design, the inner layer of bamboo fiber fabric quickly absorbs moisture, the middle layer of modified polypropylene non-woven fabric improves moisture conduction, and the outer layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric composite layer quickly discharges moisture, solving the problem of poor moisture permeability of the fabric;

[0033] 2. Modify the polypropylene fiber by adding nano-montmorillonite and a series of treatments, such as reaction with hexadecyltrimethylammonium bromide, low-temperature plasma treatment, acrylic acid grafting, etc., to improve the moisture conductivity. At the same time, a specific modification method is used to avoid the decrease in mechanical strength, ensure spinnability, and maintain comprehensive performance;

[0034] 3. Strictly control the mass ratio of nano-montmorillonite and hexadecyltrimethylammonium bromide to balance mechanical strength and air permeability. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the implementation rules described 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 creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] A moisture-permeable multi-layer composite fabric comprises an inner layer, a middle layer and an outer layer which are bonded and stacked in sequence, wherein the inner layer is a bamboo fiber fabric, the middle layer is a polypropylene non-woven fabric, and the outer layer is a composite layer of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric; the polypropylene non-woven fabric is prepared from modified polypropylene fibers by a needle punching method.

[0038] The preparation method of modified polypropylene fiber comprises the following steps:

[0039] S1. Add nano-montmorillonite to deionized water at a mass volume ratio of 1 g / 50 mL, stir to disperse the nano-montmorillonite in water to form a suspension, add hexadecyltrimethylammonium bromide to the suspension, the mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.45, continue to stir evenly, then heat to 60° C., stir to react for 7 hours, centrifuge, wash and dry to obtain modified nano-montmorillonite;

[0040] S2, adding modified nano-montmorillonite to anhydrous ethanol at a mass volume ratio of 1g / 20mL, dispersing evenly by ultrasonic oscillation, then adding polypropylene resin, the mass ratio of modified nano-montmorillonite to polypropylene resin is 1:60, stirring and mixing evenly, removing anhydrous ethanol by rotary evaporator to obtain a mixed masterbatch, adding the mixed masterbatch to a screw extruder for melt blending and granulation, the extrusion temperature is controlled at 150°C, the screw speed is 200r / min, to obtain nano-montmorillonite masterbatch;

[0041] S3, adding nano-montmorillonite masterbatch into the barrel of a spinning machine, controlling the spinning temperature at 175°C, using a metering pump to accurately control the melt extrusion amount, spinning at a spinning speed of 1700 m / min to obtain spun fibers, stretching the spun fibers, controlling the stretching multiple at 3.5 times, and controlling the stretching temperature at 90°C, and then performing heat setting treatment at 120°C to obtain montmorillonite-doped polypropylene fibers;

[0042] S4, using a low-temperature plasma device to perform plasma treatment on the montmorillonite-doped polypropylene fiber for 3 minutes, with the plasma treatment power controlled at 100 W, so as to introduce more oxygen-containing hydrophilic groups on the surface of the fiber, thereby obtaining plasma-treated polypropylene fiber;

[0043] S5. Add acrylic acid into deionized water, heat and stir to dissolve, prepare an acrylic acid solution with a mass concentration of 5%, then add ammonium persulfate initiator, the amount of ammonium persulfate added is 3% of the mass of acrylic acid, stir evenly, and then immerse the plasma-treated polypropylene fiber in the above solution according to a bath ratio of 1:30, keep warm at 68°C for 2.5 hours, repeatedly wash the treated fiber with deionized water to remove the chemical reagents remaining on the surface, place it in an oven and dry it to constant weight to obtain modified polypropylene fiber.

[0044] Preparation of composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric:

[0045] Select a polytetrafluoroethylene microporous membrane with a pore size of 0.4μm and a thickness of 0.08mm, wipe it with anhydrous ethanol cotton ball and blow dry it with nitrogen; select a high-count cotton fiber fabric with a count of 120, soak it in 0.5% sodium hydroxide solution for 30 minutes, rinse it with clean water until it is neutral, and dry it at 80℃ for 2 hours for use, and preheat it in a 40℃ constant temperature water bath for 30 minutes and stir it evenly to a viscosity of 600mPa·s. Put the polytetrafluoroethylene microporous membrane into the plasma treatment equipment and treat it at a power of 150W for 5 minutes to obtain a pretreated polytetrafluoroethylene microporous membrane. After that, use a scraper to evenly apply a 0.02mm thick adhesive on the surface of the pretreated membrane at an angle of 45° and a speed of 10cm / s, cover it with the dried high-count cotton fiber fabric, and roll it with a rubber roller twice to remove the air and fit it tightly. Then, put it into the hot pressing and shaping equipment, hot press it at 150°C and 0.5MPa for 5 minutes, and cool it to obtain the product.

[0046] A method for preparing a moisture permeable multi-layer composite fabric comprises the following steps:

[0047] The middle fabric is laid flat on a clean, dry and well-ventilated operating table, and a polyurethane adhesive with a viscosity of 600 mPa·s is evenly coated on both sides of the middle fabric. During the coating process, the thickness of the adhesive is controlled to be 0.1 mm. Then, the pre-treated inner fabric is evenly superimposed on the top of the middle fabric to ensure that the two fit tightly without wrinkles and offsets. At the same time, the outer fabric is superimposed on the bottom of the middle fabric. Subsequently, it is transferred to a laminating device for hot pressing. The hot pressing temperature is between 130°C, the pressure is controlled at 0.8 MPa, the hot pressing time is controlled at 5 min, and cooled to obtain.

[0048] Example 2

[0049] A moisture-permeable multi-layer composite fabric comprises an inner layer, a middle layer and an outer layer which are bonded and stacked in sequence, wherein the inner layer is a bamboo fiber fabric, the middle layer is a polypropylene non-woven fabric, and the outer layer is a composite layer of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric; the polypropylene non-woven fabric is prepared from modified polypropylene fibers by a needle punching method.

[0050] The preparation method of modified polypropylene fiber comprises the following steps:

[0051] S1. Add nano-montmorillonite to deionized water at a mass volume ratio of 1 g / 50 mL, stir to disperse the nano-montmorillonite in water to form a suspension, add hexadecyltrimethylammonium bromide to the suspension, the mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.35, continue to stir evenly, then heat to 60° C., stir to react for 7 hours, centrifuge, wash and dry to obtain modified nano-montmorillonite;

[0052] S2, adding modified nano-montmorillonite to anhydrous ethanol at a mass volume ratio of 1g / 20mL, dispersing evenly by ultrasonic oscillation, then adding polypropylene resin, the mass ratio of modified nano-montmorillonite to polypropylene resin is 1:60, stirring and mixing evenly, removing anhydrous ethanol by rotary evaporator to obtain a mixed masterbatch, adding the mixed masterbatch to a screw extruder for melt blending and granulation, the extrusion temperature is controlled at 150°C, the screw speed is 200r / min, to obtain nano-montmorillonite masterbatch;

[0053] S3, adding nano-montmorillonite masterbatch into the barrel of a spinning machine, controlling the spinning temperature at 175°C, using a metering pump to accurately control the melt extrusion amount, spinning at a spinning speed of 1300 m / min to obtain spun fibers, stretching the spun fibers, controlling the stretching multiple at 3.5 times, and controlling the stretching temperature at 90°C, and then performing heat setting treatment at 120°C to obtain montmorillonite-doped polypropylene fibers;

[0054] S4, using a low-temperature plasma device to perform plasma treatment on the montmorillonite-doped polypropylene fiber for 3 minutes, with the plasma treatment power controlled at 100 W, so as to introduce more oxygen-containing hydrophilic groups on the surface of the fiber, thereby obtaining plasma-treated polypropylene fiber;

[0055] S5. Add acrylic acid into deionized water, heat and stir to dissolve, prepare an acrylic acid solution with a mass concentration of 5%, then add ammonium persulfate initiator, the amount of ammonium persulfate added is 3% of the mass of acrylic acid, stir evenly, and then immerse the plasma-treated polypropylene fiber in the above solution according to a bath ratio of 1:30, keep warm at 68°C for 2.5 hours, repeatedly wash the treated fiber with deionized water to remove the chemical reagents remaining on the surface, place it in an oven and dry it to constant weight to obtain modified polypropylene fiber.

[0056] Preparation of composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric:

[0057] Select a polytetrafluoroethylene microporous membrane with a pore size of 0.2μm and a thickness of 0.06mm, wipe it with anhydrous ethanol cotton ball and blow dry it with nitrogen; select a high-count cotton fiber fabric with a count of 120, soak it in 0.5% sodium hydroxide solution for 30 minutes, rinse it with clean water until it is neutral, and dry it at 80℃ for 2 hours for use, and preheat it in a 40℃ constant temperature water bath for 30 minutes and stir it evenly to a viscosity of 600mPa·s. The polytetrafluoroethylene microporous membrane is placed in a plasma treatment device and treated at a power of 150W for 5 minutes to obtain a pretreated polytetrafluoroethylene microporous membrane. After that, use a scraper to evenly apply a 0.02mm thick adhesive on the surface of the pretreated membrane at an angle of 45° and a speed of 10cm / s, cover it with the dried high-count cotton fiber fabric, and roll it with a rubber roller twice to remove air and fit it tightly. Then, put it into the hot pressing and shaping equipment, hot press it at 150°C and 0.5MPa for 5 minutes, and cool it to obtain the product.

[0058] A method for preparing a moisture permeable multi-layer composite fabric comprises the following steps:

[0059] The middle fabric is laid flat on a clean, dry and well-ventilated operating table, and a polyurethane adhesive with a viscosity of 600 mPa·s is evenly coated on both sides of the middle fabric. During the coating process, the thickness of the adhesive is controlled to be 0.1 mm. Then, the pre-treated inner fabric is evenly superimposed on the top of the middle fabric to ensure that the two fit tightly without wrinkles and offsets. At the same time, the outer fabric is superimposed on the bottom of the middle fabric. Subsequently, it is transferred to a laminating device for hot pressing. The hot pressing temperature is between 130°C, the pressure is controlled at 0.8 MPa, the hot pressing time is controlled at 5 min, and cooled to obtain.

[0060] Example 3

[0061] A moisture-permeable multi-layer composite fabric comprises an inner layer, a middle layer and an outer layer which are bonded and stacked in sequence, wherein the inner layer is a bamboo fiber fabric, the middle layer is a polypropylene non-woven fabric, and the outer layer is a composite layer of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric; the polypropylene non-woven fabric is prepared from modified polypropylene fibers by a needle punching method.

[0062] The preparation method of modified polypropylene fiber comprises the following steps:

[0063] S1. Add nano-montmorillonite to deionized water at a mass volume ratio of 1 g / 50 mL, stir to disperse the nano-montmorillonite in water to form a suspension, add hexadecyltrimethylammonium bromide to the suspension, the mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.4, continue to stir evenly, then heat to 60° C., stir to react for 7 hours, centrifuge, wash and dry to obtain modified nano-montmorillonite;

[0064] S2, adding modified nano-montmorillonite to anhydrous ethanol at a mass volume ratio of 1g / 20mL, dispersing evenly by ultrasonic oscillation, then adding polypropylene resin, the mass ratio of modified nano-montmorillonite to polypropylene resin is 1:60, stirring and mixing evenly, removing anhydrous ethanol by rotary evaporator to obtain a mixed masterbatch, adding the mixed masterbatch to a screw extruder for melt blending and granulation, the extrusion temperature is controlled at 150°C, the screw speed is 200r / min, to obtain nano-montmorillonite masterbatch;

[0065] S3, adding nano-montmorillonite masterbatch into the barrel of a spinning machine, controlling the spinning temperature at 175°C, using a metering pump to accurately control the melt extrusion amount, spinning at a spinning speed of 1500m / min to obtain spun fibers, stretching the spun fibers, controlling the stretching multiple at 3.5 times, and controlling the stretching temperature at 90°C, and then performing heat setting treatment at 120°C to obtain montmorillonite-doped polypropylene fibers;

[0066] S4, using a low-temperature plasma device to perform plasma treatment on the montmorillonite-doped polypropylene fiber for 3 minutes, with the plasma treatment power controlled at 100 W, so as to introduce more oxygen-containing hydrophilic groups on the surface of the fiber, thereby obtaining plasma-treated polypropylene fiber;

[0067] S5. Add acrylic acid into deionized water, heat and stir to dissolve, prepare an acrylic acid solution with a mass concentration of 5%, then add ammonium persulfate initiator, the amount of ammonium persulfate added is 3% of the mass of acrylic acid, stir evenly, and then immerse the plasma-treated polypropylene fiber in the above solution according to a bath ratio of 1:30, keep warm at 68°C for 2.5 hours, repeatedly wash the treated fiber with deionized water to remove the chemical reagents remaining on the surface, place it in an oven and dry it to constant weight to obtain modified polypropylene fiber.

[0068] Preparation of composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric:

[0069] Select a polytetrafluoroethylene microporous membrane with a pore size of 0.3μm and a thickness of 0.07mm, wipe it with anhydrous ethanol cotton ball and blow dry it with nitrogen; select a high-count cotton fiber fabric with a count of 120, soak it in 0.5% sodium hydroxide solution for 30 minutes, rinse it with clean water until it is neutral, and dry it at 80℃ for 2 hours for use, and preheat it in a 40℃ constant temperature water bath for 30 minutes and stir it evenly to a silicone adhesive with a viscosity of 600mPa·s. Put the polytetrafluoroethylene microporous membrane into the plasma treatment equipment and treat it at 150W for 5 minutes to obtain a pretreated polytetrafluoroethylene microporous membrane. After that, use a scraper to evenly apply a 0.02mm thick adhesive on the surface of the pretreated membrane at an angle of 45° and a speed of 10cm / s, cover it with the dried high-count cotton fiber fabric, and roll it with a rubber roller twice to remove air and fit it tightly. Then, put it into the hot pressing and shaping equipment, hot press it at 150°C and 0.5MPa for 5 minutes, and cool it to obtain the product.

[0070] A method for preparing a moisture permeable multi-layer composite fabric comprises the following steps:

[0071] The middle fabric is laid flat on a clean, dry and well-ventilated operating table, and a polyurethane adhesive with a viscosity of 600 mPa·s is evenly coated on both sides of the middle fabric. During the coating process, the thickness of the adhesive is controlled to be 0.1 mm. Then, the pre-treated inner fabric is evenly superimposed on the top of the middle fabric to ensure that the two fit tightly without wrinkles and offsets. At the same time, the outer fabric is superimposed on the bottom of the middle fabric. Subsequently, it is transferred to a laminating device for hot pressing. The hot pressing temperature is between 130°C, the pressure is controlled at 0.8 MPa, the hot pressing time is controlled at 5 min, and cooled to obtain.

[0072] Example 4

[0073] A moisture-permeable multi-layer composite fabric comprises an inner layer, a middle layer and an outer layer which are bonded and stacked in sequence, wherein the inner layer is a bamboo fiber fabric, the middle layer is a polypropylene non-woven fabric, and the outer layer is a composite layer of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric; the polypropylene non-woven fabric is prepared from modified polypropylene fibers by a needle punching method.

[0074] The preparation method of modified polypropylene fiber comprises the following steps:

[0075] S1. Add nano-montmorillonite to deionized water at a mass volume ratio of 1 g / 50 mL, stir to disperse the nano-montmorillonite in water to form a suspension, add hexadecyltrimethylammonium bromide to the suspension, the mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.5, continue to stir evenly, then heat to 60° C., stir to react for 7 hours, centrifuge, wash and dry to obtain modified nano-montmorillonite;

[0076] S2, adding modified nano-montmorillonite to anhydrous ethanol at a mass volume ratio of 1g / 20mL, dispersing evenly by ultrasonic oscillation, then adding polypropylene resin, the mass ratio of modified nano-montmorillonite to polypropylene resin is 1:60, stirring and mixing evenly, removing anhydrous ethanol by rotary evaporator to obtain a mixed masterbatch, adding the mixed masterbatch to a screw extruder for melt blending and granulation, the extrusion temperature is controlled at 150°C, the screw speed is 200r / min, to obtain nano-montmorillonite masterbatch;

[0077] S3, adding nano-montmorillonite masterbatch into the barrel of a spinning machine, controlling the spinning temperature at 180°C, using a metering pump to accurately control the melt extrusion amount, spinning at a spinning speed of 1800 m / min to obtain spun fibers, stretching the spun fibers, controlling the stretching multiple at 3.5 times, and controlling the stretching temperature at 90°C, and then performing heat setting treatment at 120°C to obtain montmorillonite-doped polypropylene fibers;

[0078] S4, using a low-temperature plasma device to perform plasma treatment on the montmorillonite-doped polypropylene fiber for 3 minutes, with the plasma treatment power controlled at 100 W, so as to introduce more oxygen-containing hydrophilic groups on the surface of the fiber, thereby obtaining plasma-treated polypropylene fiber;

[0079] S5. Add acrylic acid into deionized water, heat and stir to dissolve, prepare an acrylic acid solution with a mass concentration of 5%, then add ammonium persulfate initiator, the amount of ammonium persulfate added is 3% of the mass of acrylic acid, stir evenly, and then immerse the plasma-treated polypropylene fiber in the above solution according to a bath ratio of 1:30, keep warm and react at 70°C for 3 hours, repeatedly wash the treated fiber with deionized water to remove the chemical reagents remaining on the surface, place it in an oven and dry it to constant weight to obtain modified polypropylene fiber.

[0080] Preparation of composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric:

[0081] Select a polytetrafluoroethylene microporous membrane with a pore size of 0.5μm and a thickness of 0.1mm, wipe it with anhydrous ethanol cotton ball and blow dry it with nitrogen; select a high-count cotton fiber fabric with a count of 120, soak it in 0.5% sodium hydroxide solution for 30min desizing, rinse it with clean water until neutral, and dry it at 80℃ for 2 hours for use, and preheat it in a 40℃ constant temperature water bath for 30 minutes and stir it evenly to a viscosity of 600mPa·s. The polytetrafluoroethylene microporous membrane is placed in a plasma treatment device and treated at 150W for 5 minutes to obtain a pretreated polytetrafluoroethylene microporous membrane. After that, use a scraper to evenly coat the surface of the pretreated membrane with a 0.02mm thick adhesive at an angle of 45° and a speed of 10cm / s, cover it with the dried high-count cotton fiber fabric, and roll it with a rubber roller twice to remove air and fit it tightly. Subsequently, put it into a hot pressing and shaping equipment, hot press it at 150℃ and 0.5MPa for 5 minutes, and cool it to obtain it.

[0082] A method for preparing a moisture permeable multi-layer composite fabric comprises the following steps:

[0083] The middle fabric is laid flat on a clean, dry and well-ventilated operating table, and a polyurethane adhesive with a viscosity of 600 mPa·s is evenly coated on both sides of the middle fabric. During the coating process, the thickness of the adhesive is controlled to be 0.1 mm. Then, the pre-treated inner fabric is evenly superimposed on the top of the middle fabric to ensure that the two fit tightly without wrinkles and offsets. At the same time, the outer fabric is superimposed on the bottom of the middle fabric. Subsequently, it is transferred to a laminating device for hot pressing. The hot pressing temperature is between 130°C, the pressure is controlled at 0.8 MPa, the hot pressing time is controlled at 5 min, and cooled to obtain.

[0084] Example 5

[0085] A moisture-permeable multi-layer composite fabric comprises an inner layer, a middle layer and an outer layer which are bonded and stacked in sequence, wherein the inner layer is a bamboo fiber fabric, the middle layer is a polypropylene non-woven fabric, and the outer layer is a composite layer of a polytetrafluoroethylene microporous membrane and a high-count cotton fiber fabric; the polypropylene non-woven fabric is prepared from modified polypropylene fibers by a needle punching method.

[0086] The preparation method of modified polypropylene fiber comprises the following steps:

[0087] S1. Add nano-montmorillonite to deionized water at a mass volume ratio of 1 g / 50 mL, stir to disperse the nano-montmorillonite in water to form a suspension, add hexadecyltrimethylammonium bromide to the suspension, the mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.3, continue to stir evenly, then heat to 60° C., stir to react for 7 hours, centrifuge, wash and dry to obtain modified nano-montmorillonite;

[0088] S2, adding modified nano-montmorillonite to anhydrous ethanol at a mass volume ratio of 1g / 20mL, dispersing evenly by ultrasonic oscillation, then adding polypropylene resin, the mass ratio of modified nano-montmorillonite to polypropylene resin is 1:60, stirring and mixing evenly, removing anhydrous ethanol by rotary evaporator to obtain a mixed masterbatch, adding the mixed masterbatch to a screw extruder for melt blending and granulation, the extrusion temperature is controlled at 150°C, the screw speed is 200r / min, to obtain nano-montmorillonite masterbatch;

[0089] S3, adding nano-montmorillonite masterbatch into the barrel of a spinning machine, controlling the spinning temperature at 170°C, using a metering pump to accurately control the melt extrusion amount, spinning at a spinning speed of 1200m / min to obtain spun fibers, stretching the spun fibers, controlling the stretching multiple at 3.5 times, and controlling the stretching temperature at 90°C, and then performing heat setting treatment at 120°C to obtain montmorillonite-doped polypropylene fibers;

[0090] S4, using a low-temperature plasma device to perform plasma treatment on the montmorillonite-doped polypropylene fiber for 3 minutes, with the plasma treatment power controlled at 100 W, so as to introduce more oxygen-containing hydrophilic groups on the surface of the fiber, thereby obtaining plasma-treated polypropylene fiber;

[0091] S5. Add acrylic acid into deionized water, heat and stir to dissolve, prepare an acrylic acid solution with a mass concentration of 5%, then add ammonium persulfate initiator, the amount of ammonium persulfate added is 3% of the mass of acrylic acid, stir evenly, and then immerse the plasma-treated polypropylene fiber in the above solution according to a bath ratio of 1:30, keep warm at 65°C for 2 hours, repeatedly wash the treated fiber with deionized water to remove the chemical reagents remaining on the surface, place it in an oven and dry it to constant weight to obtain modified polypropylene fiber.

[0092] Preparation of composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric:

[0093] Select a polytetrafluoroethylene microporous membrane with a pore size of 0.1μm and a thickness of 0.05mm, wipe it with anhydrous ethanol cotton ball and blow dry it with nitrogen; select a high-count cotton fiber fabric with a count of 120, soak it in 0.5% sodium hydroxide solution for 30 minutes, rinse it with clean water until it is neutral, and dry it at 80℃ for 2 hours for use, and preheat it in a 40℃ constant temperature water bath for 30 minutes and stir it evenly to a viscosity of 600mPa·s. The polytetrafluoroethylene microporous membrane is placed in a plasma treatment device and treated at a power of 150W for 5 minutes to obtain a pretreated polytetrafluoroethylene microporous membrane. After that, use a scraper to evenly apply a 0.02mm thick adhesive on the surface of the pretreated membrane at an angle of 45° and a speed of 10cm / s, cover it with the dried high-count cotton fiber fabric, and roll it with a rubber roller twice to remove air and fit it tightly. Then, put it into the hot pressing and shaping equipment, hot press it at 150°C and 0.5MPa for 5 minutes, and cool it to obtain the product.

[0094] A method for preparing a moisture permeable multi-layer composite fabric comprises the following steps:

[0095] The middle fabric is laid flat on a clean, dry and well-ventilated operating table, and a polyurethane adhesive with a viscosity of 600 mPa·s is evenly coated on both sides of the middle fabric. During the coating process, the thickness of the adhesive is controlled to be 0.1 mm. Then, the pre-treated inner fabric is evenly superimposed on the top of the middle fabric to ensure that the two fit tightly without wrinkles and offsets. At the same time, the outer fabric is superimposed on the bottom of the middle fabric. Subsequently, it is transferred to a laminating device for hot pressing. The hot pressing temperature is between 130°C, the pressure is controlled at 0.8 MPa, the hot pressing time is controlled at 5 min, and cooled to obtain.

[0096] Comparative Example 1

[0097] The difference between Comparative Example 1 and Example 1 is:

[0098] Replace modified polypropylene fiber with regular polypropylene fiber;

[0099] The remaining steps are the same as those in Example 1.

[0100] Comparative Example 2

[0101] The difference between Comparative Example 2 and Example 1 is:

[0102] Step S1 is omitted in the preparation process of modified polypropylene fiber.

[0103] Replace the modified nano-montmorillonite with ordinary nano-montmorillonite.

[0104] The remaining steps are the same as those in Example 1.

[0105] Comparative Example 3

[0106] The difference between Comparative Example 3 and Example 5 is that:

[0107] In step S1 of the modified polypropylene fiber preparation process,

[0108] The mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.2.

[0109] The remaining steps are the same as those in Example 1.

[0110] Comparative Example 4

[0111] The difference between Comparative Example 4 and Example 4 is that:

[0112] In step S1 of the modified polypropylene fiber preparation process,

[0113] The mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.6.

[0114] The remaining steps are the same as those in Example 4.

[0115] Comparative Example 5

[0116] The difference between Comparative Example 5 and Example 4 is that:

[0117] In step S1 of the modified polypropylene fiber preparation process,

[0118] The mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.7.

[0119] The remaining steps are the same as those in Example 4.

[0120] Performance Test:

[0121] 1. Mechanical strength test of middle-layer polypropylene non-woven fabric: Cut samples with a length of 200 mm and a width of 50 mm from the middle-layer polypropylene non-woven fabric of each embodiment and comparative example, and prepare 5 samples of each type in parallel. Use an electronic universal material testing machine with an accuracy of ±0.5%, set the tensile speed to 50 mm / min, and the initial clamping distance to 100 mm. Clamp the sample vertically between the upper and lower clamps to ensure that the center lines coincide, start the testing machine to stretch until it breaks, and record the maximum load value. The tensile strength is obtained by dividing the maximum load value by the width and thickness of the sample, and the thickness of the sample is measured at 5 locations to take the average value. Finally, the average value of the tensile strength of 5 samples of each sample is calculated as the test result.

[0122] 2. Test of moisture permeability (water vapor permeability) of composite fabrics: 70mm diameter circular specimens were cut from the composite fabrics of each embodiment and comparative example, and 3 specimens of each kind were prepared in parallel. The moisture permeability cup method test equipment was used, including a moisture permeability cup with an inner diameter of 65mm and a depth of 25mm and a constant temperature and humidity chamber capable of controlling temperature (38±2)℃ and humidity (90±5)%. Distilled water was filled in the moisture permeability cup to a distance of about 3mm from the cup mouth, and the specimen was tightly fixed to the cup mouth with a sealant. The moisture permeability cup was placed in the constant temperature and humidity chamber for 24 hours, and the initial mass m1 before placement and the mass m2 after 24 hours were weighed with an electronic balance with an accuracy of 0.001g. The moisture permeability was obtained according to the formula (m2-m1) / sample area×24, and the average moisture permeability of the 3 specimens of each sample was calculated as the test result.

[0123] 3. Test of air permeability (air permeability) of composite fabrics: Cut circular specimens with a diameter of 75 mm from the composite fabrics of each embodiment and comparative example, and prepare 5 specimens of each type in parallel. Use an air permeability meter with a test pressure difference range of 0-2000 Pa and an accuracy of ±2%, and set the test pressure difference to 100 Pa. Install the specimen flat on the test hole of the air permeability meter to ensure that there are no wrinkles and that it is well sealed. Start the air permeability meter and record the air flow rate per unit time through the unit area of ​​the specimen under the set pressure difference. Change the flow rate unit from L / (m 2 ·s) is converted into mm / s, and the average air permeability of 5 samples of each sample is calculated as the test result.

[0124]

[0125]

[0126] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A moisture permeable multi-layer composite fabric, characterized in that: It comprises an inner layer, a middle layer and an outer layer which are bonded and stacked in sequence, wherein the inner layer is bamboo fiber fabric, the middle layer is polypropylene non-woven fabric, and the outer layer is a composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric.

2. A moisture permeable multi-layer composite fabric according to claim 1, characterized in that: The polypropylene non-woven fabric is prepared from modified polypropylene fibers.

3. A moisture permeable multi-layer composite fabric according to claim 2, characterized in that: The preparation method of the modified polypropylene fiber comprises the following steps: S1, adding nano-montmorillonite to deionized water, stirring to make the nano-montmorillonite preliminarily dispersed in the water to form a suspension, adding hexadecyltrimethylammonium bromide to the suspension, continuing to stir evenly, then heating to 60° C., stirring for 7 hours, centrifugally separating, washing and drying to obtain modified nano-montmorillonite; S2, adding the modified nano-montmorillonite into anhydrous ethanol, dispersing it evenly by ultrasonic oscillation, then adding the polypropylene resin, stirring and mixing evenly, removing the anhydrous ethanol by a rotary evaporator to obtain a mixed masterbatch, adding the mixed masterbatch into a screw extruder for melt blending and granulation, and obtaining a nano-montmorillonite masterbatch; S3, adding nano-montmorillonite masterbatch into the spinning machine barrel, using a metering pump to accurately control the melt extrusion amount, spinning at a spinning speed of 1200-1800 m / min to obtain primary fibers, stretching the primary fibers, and then performing heat setting treatment to obtain montmorillonite-doped polypropylene fibers; S4, using a low-temperature plasma device to perform plasma treatment on the montmorillonite-doped polypropylene fiber, so as to introduce more oxygen-containing hydrophilic groups on the surface of the montmorillonite-doped polypropylene fiber, thereby obtaining a plasma-treated polypropylene fiber; S5. Add acrylic acid into deionized water, heat and stir to dissolve, obtain acrylic acid solution, then add ammonium persulfate initiator, stir evenly, then immerse the plasma-treated polypropylene fiber in the above solution, keep warm for reaction, repeatedly wash the treated fiber with deionized water to remove the chemical reagents remaining on the surface, place in an oven and dry to constant weight, to obtain modified polypropylene fiber.

4. A moisture permeable multi-layer composite fabric according to claim 3, characterized in that: In the step S1, the mass ratio of nano-montmorillonite to hexadecyltrimethylammonium bromide is 1:0.3-0.

5.

5. The moisture permeable multi-layer composite fabric according to claim 3, characterized in that: In step S3, the spinning temperature is controlled at 170-180°C.

6. The moisture permeable multi-layer composite fabric according to claim 3, characterized in that: In step S5, the reaction temperature is kept at 65-70° C. and the reaction is kept at 2-3 hours.

7. The moisture permeable multi-layer composite fabric according to claim 1, characterized in that: The preparation method of the composite layer of polytetrafluoroethylene microporous membrane and high-count cotton fiber fabric comprises the following steps: The polytetrafluoroethylene microporous membrane is subjected to plasma treatment to increase its surface activity to obtain a pretreated polytetrafluoroethylene microporous membrane, an adhesive is coated on the surface of the pretreated polytetrafluoroethylene microporous membrane, a high-count cotton fiber fabric is covered on the pretreated polytetrafluoroethylene microporous membrane to make the two closely fit, and hot pressing is performed to shape the membrane, and the membrane is cooled to obtain the membrane.

8. The moisture permeable multi-layer composite fabric according to claim 8, characterized in that: The pore size of the polytetrafluoroethylene microporous membrane is 0.1-0.5 μm, and the thickness is 0.05-0.1 mm.

9. A method for preparing a moisture permeable multi-layer composite fabric according to any one of claims 1 to 8, characterized in that: The following steps are involved: The adhesive is applied to both sides of the middle layer, and then the inner layer and the outer layer are respectively stacked on the upper and lower sides of the middle layer, and then placed in a laminating device for heat pressing treatment, and after cooling, the product is obtained.

10. The method for preparing a moisture permeable multi-layer composite fabric according to claim 9, characterized in that: The adhesive is a polyurethane adhesive.

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