Nanofiber thermal insulation material and preparation method thereof

Abstract

The present invention provides a composite fabric having the functions of warmth preservation, far infrared, moisture permeability, and waterproofing, and having the characteristics of being light and thin, and a preparation method thereof. The light and thin nanofiber warmth preservation and moisture permeability fabric comprises an outer layer support fabric, a nanofiber far infrared waterproof and moisture permeable layer, a nanofiber warmth preservation layer, and a heating fabric. The porous mesh fiber structure with far infrared ceramic particles prepared by an electrospinning process has a far infrared function and a heat preservation function of 10000-20000 g / m 2 / 24h moisture permeability and 10-20m hydrostatic pressure resistance. The polyurethane hollow nanofibers prepared by coaxial electrospinning process have excellent warming effect as a thermal insulation layer. The thermal insulation fabric provided by the present invention has a thickness range of 2-4.5mm, which is lighter than traditional thermal insulation fabrics and can be more widely used in outdoor sports, tourism, exploration and other fields.

Description

Technical Field

[0001] The invention patent belongs to the technical field of composite fabrics, and in particular relates to nano composite fabrics and their preparation methods. Background Art

[0002] Nowadays, travel, exploration, and extreme sports have become an important part of people's lives. Especially in recent years, more and more winter sports have entered the lives of the public. Therefore, in harsh environments such as low temperature, severe cold, wind and rain, and even dark and damp, clothing has become an indispensable and important equipment to resist the harsh external environment. Although traditional thermal insulation fabrics can achieve a certain degree of warmth, defects such as suffocation, non-waterproofness, and bulkiness have become pain points that affect their use.

[0003] Polymer nanomaterials have many excellent properties, such as extremely small fiber diameter, extremely high porosity and extremely large specific surface area. After the polymer nanofiber non-woven fabric is opened, its density can even reach 1 / 6 of the air density, with excellent fluffiness and excellent warmth retention effect. Polymer nanofibers are also good carriers. After functional materials (such as far-infrared materials, hydrophobic and oleophobic materials) are attached to the surface of polymer nanofibers, due to their large specific surface area, the performance of functional materials can be well exerted. Therefore, the use of nanofiber materials in the field of composite fabrics has a high potential application value.

[0004] In the current thermal insulation and breathable fabrics and their preparation methods, such as the technologies disclosed in Patent Application No. 202010824245.1 and Patent Application No. 202010847288.1, the preparation of new thermal insulation materials using nanofiber materials has been realized, but there are still some shortcomings in the preparation process of the thermal insulation layer and the heat-generating layer.

[0005] A graphene negative ion heating inner warmer published by the Chinese invention patent with application number 202010824245.1 includes a heat insulation layer and a heating layer. The heat insulation layer is formed by continuously depositing nanofibers containing nano-aluminum powder on cellulose fibers by electrospinning. Although the heat insulation layer is nanofibers, the nanofibers formed by direct electrospinning are relatively dense. It is a planar porous membrane structure with very low fluffiness, and its thermal insulation performance is not good. The heating layer is made by mixing graphene, aqueous negative oxygen ion powder and far-infrared ceramic powder in proportion, adding antibacterial agents and penetrants thereto, preparing a mixed solution, and adding the mixed solution to a polyacrylonitrile-based polymer for spinning. However, the heating effect of the far-infrared ceramic powder is not good, and it can be used as an auxiliary function.

[0006] The Chinese invention patent with application number 202010847288.1 published a combined nested cold-proof clothing that is windproof, waterproof, warm, and breathable. It is also lightweight, comfortable, and wear-resistant. Its warm-keeping flakes are nanofiber aerogel. However, the preparation process of aerogel is complicated and expensive at this stage. In addition, the material does not have the far-infrared self-heating function, and its warmth-keeping performance is poor. Summary of the invention

[0007] It should be understood that all combinations of the foregoing concepts and additional concepts discussed in more detail below (assuming such concepts are not mutually contradictory) are considered part of the inventive subject matter disclosed herein. Specifically, all combinations of claimed subject matter appearing in this disclosure are considered part of the inventive subject matter disclosed herein. It should also be understood that the terms explicitly used herein may appear in any disclosure incorporated by reference herein, which should be consistent with the meaning most consistent with the specific concepts disclosed herein.

[0008] In order to solve the above-mentioned deficiencies in the existing nanofiber thermal insulation fabric and the preparation process thereof, the present invention provides a nanofiber thermal insulation material and a preparation method thereof.

[0009] The present invention provides a nanofiber thermal insulation material, which has the functions of thermal insulation, far infrared, moisture permeability, and waterproofing, and is also light and thin. The fabric comprises an outer fabric 100, a nanofiber far infrared waterproof and moisture permeable layer 200, a nanofiber thermal insulation layer 300, and a heat-generating fabric 400, so that it can be more widely used in the field of outdoor products.

[0010] The present invention provides a nanofiber thermal insulation material, wherein the outer fabric 100 is a protective support layer, and the outer fabric 100 is made of polyester, nylon, acrylic fiber, leather, and has a gram weight of 70-100gsm and a thickness of 0.3-0.5mm, which provides the fabric with certain stiffness and anti-wrinkle performance.

[0011] The present invention provides a nanofiber thermal insulation material. The nanofiber far-infrared waterproof and breathable layer 200 is a porous mesh structure film 201 formed by an electrostatic spinning process. The material is a polymer polyurethane with a gram weight of 6-15gsm, a thickness of 15-20μm, and a moisture permeability of 10000-20000g / m 2 / 24h, the waterproof performance is resistant to 10-20m hydrostatic pressure, and the nanofiber far-infrared waterproof and breathable membrane also carries far-infrared nano-ceramic particles 202. The higher moisture permeability can make the fabric more comfortable while keeping warm, and the ability to withstand more than 10m of hydrostatic pressure can make the fabric more widely used in the field of outdoor products. In addition, the higher moisture permeability can also make it easier for the inner layer of moisture-absorbing and heat-generating fabric to discharge the moisture it contains during the drying and dehumidification process.

[0012] The present invention provides a nanofiber thermal insulation material. The nanofiber thermal insulation layer 300 is a fluffy, low-density hollow nanofiber 301 non-woven fabric formed by an electrospinning process. The material is a polymer polyurethane with a density of 10-100 mg / cm 3 The outer diameter of the hollow nanofiber is 400-1000nm, the inner diameter is 200-600nm, and the thickness is 0.1-1mm. Smaller density means higher fluffiness and better warmth retention. Its fluffiness is comparable to down. In addition, the hollow nanofiber is more similar to the hair of a polar bear and has better insulation than traditional solid fibers. Most importantly, compared to traditional insulation materials, the thickness of the nanofiber insulation layer has outstanding advantages.

[0013] The present invention provides a nanofiber thermal insulation material. The heat-generating fabric 400 is a fabric formed by moisture-absorbing heat-generating fibers, with a gram weight of 70-100 gsm and a thickness of 1.5-3 mm.

[0014] The present invention provides a method for preparing a nanofiber thermal insulation material, comprising the following steps:

[0015] Step 1: Prepare spinning solution: Mix the polymer polyurethane material, solvent and additives to prepare a polymer solution, and divide the solution into two equal parts;

[0016] Step 2: preparing the nanofiber far-infrared waterproof breathable and moisture permeable layer 200: mixing a portion of the polymer polyurethane solution in step 1 with the far-infrared nano-ceramic particles 202 into a spinning emulsion, and then electrospinning to obtain a nanofiber far-infrared waterproof and moisture permeable porous membrane as the nanofiber far-infrared waterproof and moisture permeable layer 200;

[0017] Step 3: preparing the nanofiber thermal insulation layer 300: a portion of the polymer polyurethane solution in step 1 is subjected to coaxial electrospinning to obtain core-shell nanofibers with polyurethane as the shell, and after removing the fiber core of the core-shell nanofibers, a hollow nanofiber 301 non-woven fabric is obtained as the nanofiber thermal insulation layer 300;

[0018] Step 4: preparing an outer waterproof and breathable fabric: heat-pressing and bonding the outer fabric 100 and the nanofiber far-infrared waterproof and breathable layer 200 to form an outer waterproof and breathable fabric;

[0019] Step 5: Prepare nanofiber thermal insulation and moisture permeable fabric: place the nanofiber thermal insulation layer 300 between the outer waterproof and moisture permeable fabric and the heat-generating fabric 400, and sew them together to form the nanofiber thermal insulation and moisture permeable fabric.

[0020] The high molecular weight polyurethane in the polyurethane solution has a molecular weight of 200k-800k, the solvents are DMF and DMAc, the additives are HFIP and acetone, the polyurethane concentration is 8wt%-25wt%, the solvent concentration is 45wt%-88wt%, and the additive concentration is 4wt%-20wt%.

[0021] The far-infrared nano-ceramic particles 202 are zirconium oxide or aluminum oxide powders, the powder diameter is 10-300 nm, and the solid content of the far-infrared nano-ceramic particles 202 in the polyurethane solution is 1wt%-10wt%.

[0022] The polyurethane-shell core-shell nanofibers refer to polyurethane-paraffin oil core-shell nanofibers prepared by coaxial electrospinning with a polyurethane solution as the outer shell and paraffin oil as the inner core.

[0023] The hollow nanofiber nonwoven fabric refers to the fluffy polyurethane hollow nanofiber 301 obtained by soaking the polyurethane-paraffin oil core-shell nanofiber obtained by coaxial spinning with ethanol or ether to remove the paraffin oil inside the fiber and drying it with 60° C. hot air.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] A nanofiber thermal insulation material has good thermal insulation performance, the fluffiness of the thermal insulation layer can reach 150FP, and the fibers therein are hollow fibers with better thermal insulation performance.

[0026] A nanofiber thermal insulation material also has extremely lightweight properties and has a thickness of 2–4.5 mm.

[0027] A nanofiber thermal insulation material has the function of self-heating.

[0028] A nanofiber thermal insulation material has higher moisture permeability, which enables the moisture-absorbing and heat-generating fibers to release moisture more easily when hanging out to dry.

[0029] A nanofiber thermal insulation material has far infrared function. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a nanofiber thermal insulation material of the present invention;

[0031] Figure 2 This is a microscopic image of a nanofiber far-infrared waterproof and breathable porous membrane in a nanofiber thermal insulation material of the present invention;

[0032] Figure 3 This is a microscopic image of a nanofiber thermal insulation layer in a nanofiber thermal insulation material of the present invention;

[0033] In the attached figure: 100. outer fabric; 200. nanofiber far-infrared waterproof and breathable layer; 300. nanofiber thermal insulation layer; 400. heating fabric; 201. porous mesh fiber membrane; 202. far-infrared nano-ceramic particles; 301. hollow nanofiber. DETAILED DESCRIPTION

[0034] In the detailed description that follows, representative embodiments that disclose specific details are set forth for purposes of explanation and not limitation to provide a thorough understanding of the claimed invention. However, it will be apparent to those skilled in the art having the benefit of this disclosure that other embodiments in accordance with the teachings of the present invention that depart from the details disclosed herein are still within the scope of the appended claims. In addition, descriptions of well-known apparatus and methods may be omitted so as not to obscure the description of representative implementation methods. Such methods and apparatus are clearly within the scope of the claimed invention.

[0035] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0036] Example 1

[0037] A high molecular weight polyurethane with a molecular weight of 200k was dissolved in DMF and HFIP was added, wherein the concentration of polyurethane was 25wt%, the concentration of DMF was 45wt%, and the concentration of additives was 20wt%. The solution was stirred evenly and then divided into two equal parts.

[0038] A polyurethane solution is mixed with nano zirconium oxide particles to prepare a polyurethane-zirconium oxide emulsion. The average diameter of the zirconium oxide nanoparticles is 10 nm, and the solid content of the particles in the emulsion is 1 wt%.

[0039] The polyurethane-zirconia emulsion was spun by a needle electrospinning device to prepare a nanofiber waterproof and breathable porous membrane with far infrared function. The membrane thickness is 15μm, the gram weight is 6gsm, and the moisture permeability is 20000g / m 2 / 24h or more, and the hydrostatic pressure resistance is more than 10m.

[0040] Another portion of polyurethane solution is used as the shell solution for coaxial spinning, and paraffin oil is used as the core solution for coaxial spinning. After coaxial electrospinning, polyurethane-paraffin oil core-shell nanofibers are obtained.

[0041] The core-shell nanofibers of polyurethane-paraffin oil were soaked in ethanol for 12 hours to completely remove the internal paraffin oil, and then dried with hot air at 60 degrees to obtain the nanofiber thermal insulation layer. The nanofibers in the thermal insulation layer are hollow polyurethane fibers with an outer diameter of 400nm, an inner diameter of 200nm, and a density of 10mg / cm 3 , thickness is 1mm.

[0042] The polyester with a gram weight of 70gsm and a thickness of 0.3mm is thermally pressed and bonded with the nanofiber far-infrared waterproof and breathable layer to form an outer waterproof and breathable fabric.

[0043] The moisture-absorbing and heat-generating fiber fabric with a gram weight of 70 gsm and a thickness of 1.5 mm is taken as the heat-generating fabric (400).

[0044] The nanofiber thermal insulation layer is placed between the outer waterproof and breathable fabric and the heat-generating fabric (400) and fixed by sewing to obtain the nanofiber thermal insulation and breathable fabric.

[0045] The produced thin and lightweight nanofiber thermal and moisture-permeable fabric not only has self-heating and far-infrared functions, but also has a thickness of only 2.8mm.

[0046] Example 2

[0047] A high molecular weight polyurethane with a molecular weight of 800k was dissolved in DMF and HFIP was added, wherein the concentration of polyurethane was 8wt%, the concentration of DMF was 88wt%, and the concentration of additives was 4wt%. The solution was stirred evenly and then divided into two equal parts.

[0048] A polyurethane-zirconia emulsion is prepared by mixing nano zirconium oxide particles into a polyurethane solution. The average diameter of the zirconium oxide nanoparticles is 300 nm, and the solid content of the particles in the emulsion is 10 wt%.

[0049] The polyurethane-zirconia emulsion was spun by a needle electrospinning device to prepare a nanofiber waterproof and breathable porous membrane with far infrared function. The membrane thickness is 20μm, the gram weight is 15gsm, and the moisture permeability is 10000g / m 2 / 24h or more, and the hydrostatic pressure resistance is more than 20m.

[0050] Another portion of polyurethane solution is used as the shell solution for coaxial spinning, and paraffin oil is used as the core solution for coaxial spinning. After coaxial electrospinning, polyurethane-paraffin oil core-shell nanofibers are obtained.

[0051] The polyurethane-paraffin oil core-shell nanofibers were soaked in ethanol for 12 hours to completely remove the internal paraffin oil, and then dried with hot air at 60 degrees to obtain the nanofiber thermal insulation layer. The nanofibers in the thermal insulation layer are hollow polyurethane fibers with an outer diameter of 1000nm, an inner diameter of 600nm, and a density of 100mg / cm 3 , thickness is 0.1mm.

[0052] Leather with a gram weight of 100 gsm and a thickness of 0.5 mm is heat-pressed and bonded with a nanofiber far-infrared waterproof and breathable layer to form an outer waterproof and breathable fabric.

[0053] The moisture-absorbing and heat-generating fiber fabric with a gram weight of 100 gsm and a thickness of 3 mm is taken as the heat-generating fabric (400).

[0054] The nanofiber thermal insulation layer is placed between the outer waterproof and breathable fabric and the heat-generating fabric (400) and fixed by sewing to obtain the nanofiber thermal insulation and breathable fabric.

[0055] The prepared nanofiber thermal insulation material not only has self-heating and far-infrared functions, but also has a thickness of only 3.6mm.

Claims

1. A nanofiber thermal insulation material, characterized in that: The material has the functions of warmth preservation, far infrared, moisture permeability and waterproofness, and is also light and thin. The material comprises an outer layer fabric (100), a nanofiber far infrared waterproof and moisture permeable layer (200), a nanofiber thermal insulation layer (300), and a heat-generating fabric (400). The nanofiber far infrared waterproof and moisture permeable layer (200) is a porous mesh fiber membrane (201) formed by an electrostatic spinning process, and is made of high molecular weight polyurethane, has a gram weight of 6-15gsm, a thickness of 15-20μm, and a moisture permeability of 10000-20000g / m 2 / 24h, the waterproof performance is resistant to 10-20m hydrostatic pressure, the porous mesh fiber membrane (201) also carries far-infrared nano-ceramic particles (202), the nanofiber thermal insulation layer (300) is a fluffy low-density hollow nanofiber (301) non-woven fabric formed by electrospinning technology, and its material is high molecular polyurethane with a density of 10-100mg / cm 3 , the outer diameter of the hollow nanofibers is 400–1000 nm, the inner diameter is 200–600 nm, and the thickness is 0.1–1 mm; The preparation method of the nanofiber thermal insulation material comprises the following steps: Step 1: Prepare spinning solution: Mix the polymer polyurethane material, solvent and additives to prepare a polymer solution, and divide the solution into two equal parts; Step 2: preparing a nanofiber far-infrared waterproof and breathable layer (200): mixing a portion of the polymer polyurethane solution in step 1 with far-infrared nano-ceramic particles (202) into a spinning emulsion, and then subjecting the mixture to electrostatic spinning to obtain a porous mesh fiber membrane (201) as the nanofiber far-infrared waterproof and breathable layer (200); Step 3: preparing a nanofiber thermal insulation layer (300): a portion of the polymer polyurethane solution in step 1 is subjected to coaxial electrospinning to obtain core-shell nanofibers with polyurethane as the shell, and hollow nanofibers (301) are obtained after removing the fiber core of the core-shell nanofibers, which serve as the nanofiber thermal insulation layer (300); Step 4: preparing an outer waterproof and breathable fabric: heat-pressing and bonding the outer fabric (100) and the nanofiber far-infrared waterproof and breathable layer (200) to form an outer waterproof and breathable fabric; Step 5: preparing a nanofiber thermal insulation material: placing a nanofiber thermal insulation layer (300) between the outer waterproof and breathable fabric and the heat-generating fabric (400), and sewing them together to form the nanofiber thermal insulation material; The polyurethane core-shell nanofibers are polyurethane-paraffin oil core-shell nanofibers prepared by coaxial electrospinning with polyurethane solution as the shell and paraffin oil as the core. The hollow nanofiber (301) is obtained by soaking the polyurethane-paraffin oil core-shell nanofiber obtained by coaxial spinning in ethanol or ether to remove the paraffin oil inside the fiber, and then drying it with hot air at 60°C to obtain the fluffy polyurethane hollow nanofiber (301).

2. The nanofiber thermal insulation material according to claim 1, characterized in that: The outer fabric (100) is a protective support layer, and its material is polyester, nylon, acrylic, or leather, with a gram weight of 70-100 gsm and a thickness of 0.3-0.5 mm.

3. The nanofiber thermal insulation material according to claim 1, characterized in that: The heat-generating fabric (400) is a fabric formed by moisture-absorbing heat-generating fibers, with a gram weight of 70-100 gsm and a thickness of 1.5-3 mm.

4. The nanofiber thermal insulation material according to claim 1, characterized in that: The molecular weight of the high molecular weight polyurethane in the spinning solution is 200k-800k, the solvent is DMF and DMAc, the additive is HFIP and acetone, the polyurethane concentration is 8wt%-25wt%, the solvent concentration is 45wt%-88wt%, and the additive concentration is 4wt%-20wt%.

5. The nanofiber thermal insulation material according to claim 1, characterized in that: The far-infrared nano-ceramic particles (202) are zirconium oxide or aluminum oxide powders, the powder diameter is 10-300 nm, and the solid content of the far-infrared nano-ceramic particles (202) in the polyurethane solution is 1wt%-10wt%.

Images