Thermal insulation fabric and method of making the same

Abstract

The present application relates to the technical field of functional fabric, and particularly relates to a thermal insulation fabric and a preparation method thereof.The thermal insulation fabric provided by the present application is a fabric impregnated with modified silica powder, wherein the raw materials required by the modified silica powder include, in terms of weight parts, 20-30 parts of a silicone source, 10-20 parts of nanometer carbon fibers, 40-60 parts of water, 0.02-0.2 parts of a catalyst, 4-8 parts of a solubilizing agent, 0.05-0.4 parts of a surfactant and 50-80 parts of a low-surface-tension solvent.By using a specific silicone source and 'implanting' nanometer carbon fibers into the obtained fumed silica, flexible fumed silica is obtained; after the flexible fumed silica is ground into powder, the powder is mixed with a solvent and the fabric is impregnated, a thermal insulation fabric with good thermal insulation performance is obtained.

Description

Technical Field

[0001] This invention relates to the field of functional fabric technology, and in particular to a thermal insulation fabric and its preparation method. Background Technology

[0002] Thermal insulation fabric is a type of fabric that has heat insulation properties. Using it to make clothing can improve the warmth retention of clothing, which is especially important for people in cold regions.

[0003] Aerogels possess a unique three-dimensional nanoporous structure with a porosity of up to 800 μm. 2 Specific surface area per g, porosity of over 80%, and as low as 100 kg / m³ 3 With its high bulk density and pore size of about 50 nm, it contains a large amount of air, and its pore size is smaller than the average free path of air molecules. Therefore, it has low gas phase conductivity and solid phase conductivity at normal temperature and pressure, making it a good thermal insulation material.

[0004] Currently, there are technologies that apply aerogel to textile fabrics to improve their thermal insulation performance. However, due to the low mechanical properties and brittleness of aerogels, they are prone to separation from the fabric layer when laminated together. To address this issue, existing technologies often use adhesives to bond the aerogel to the textile layer. However, as the fabric is used over time, the adhesives tend to age and fail, causing the aerogel layer to separate from the fabric layer and detach, thus rendering the fabric ineffective for thermal insulation. Other research has explored coating methods where aerogel powder is applied to the fabric layer. However, due to the low mechanical properties of aerogel powder, the resulting coating layer is not very flexible and is easily pulverized, making it prone to detachment from the textile layer and affecting the fabric's thermal insulation performance. Summary of the Invention

[0005] In view of this, the present invention provides a thermal insulation fabric and its preparation method. The modified silica powder in the fabric contains nano-carbon fibers and a specific type of organosilicon source, which improves its flexibility. Furthermore, the modified silica powder can be chemically bonded to the fabric, making the "bonding" between the fabric and the fabric stronger.

[0006] To solve the above technical problems, the present invention provides a thermal insulation fabric, wherein the thermal insulation fabric is a fabric impregnated with modified silica powder, and the raw materials required for preparing the modified silica powder include, by weight:

[0007] The composition includes 20-30 parts of organosilicon source, 10-20 parts of carbon nanofibers, 40-60 parts of water, 0.02-0.2 parts of acidic catalyst, 0.1-0.3 parts of alkaline catalyst, 4-8 parts of solubilizer, 0.05-0.4 parts of surfactant, and 50-80 parts of low surface tension solvent.

[0008] The organosilicon source includes at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, or vinyldimethylmethoxysilane.

[0009] The thermal insulation fabric provided by this invention uses a specific type of organosilicon source as raw material and "embedding" nanofibers into the resulting fumed silica. Utilizing the advantages of the length and strength of the nanofibers, they are interwoven and wrapped within or between fumed silica molecules, generating a certain "adhesive force" between the fumed silica molecules, thereby improving the flexibility of the coating layer formed by the fumed silica powder. Secondly, the modified silica powder is composited with the fabric through impregnation. The silicon-oxygen bonds on the surface of the modified silica powder combine with the hydroxyl groups on the surface of the fabric layer to form hydrogen bonds, thereby achieving a firm bond between the thermally insulating fumed silica powder and the fabric layer.

[0010] In conjunction with the first aspect, the fabric is pure cotton or a cotton blend.

[0011] In conjunction with the first aspect, the length of the carbon nanofiber is 0.5 to 2 mm and the diameter is 1 to 10 nm. This range of length and diameter of carbon nanofiber can ensure that the mechanical properties and flexibility of the coating obtained from fumed silica powder are improved simultaneously.

[0012] Preferably, the length of the carbon nanofiber is 0.5 to 1 mm and the diameter is 1 to 5 nm.

[0013] In conjunction with the first aspect, the acidic catalyst includes at least one of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, oxalic acid, or acetic acid.

[0014] In conjunction with the first aspect, the alkaline catalyst includes ammonia or sodium hydroxide.

[0015] In conjunction with the first aspect, the solubilizer is an alcohol solvent or an ether solvent.

[0016] Optionally, the alcohol solvent includes at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, or isobutanol, and the ether solvent includes diethyl ether or methyl tert-butyl ether.

[0017] In conjunction with the first aspect, the surfactant includes at least one of alkyl dimethyl hydroxypropyl phosphate betaine, alkyl dimethyl sulfoethyl betaine, alkyl dimethyl sulfopropyl betaine, or sodium dodecyl aminopropionate.

[0018] In conjunction with the first aspect, the low surface tension solvent includes at least one of n-hexane, n-heptane, n-octane, isopropanol, or chloroform.

[0019] A second aspect of the present invention provides a method for preparing the above-mentioned thermal insulation fabric, comprising the steps of:

[0020] S1. The organosilicon source, carbon nanofibers, water, acidic catalyst and surfactant are mixed and hydrolyzed, and then an alkaline catalyst is added to carry out a polycondensation reaction to prepare a flexible wet gel.

[0021] S2. The flexible wet gel is immersed in a mixture of the solubilizer and the low surface tension solvent to prepare the flexible gel;

[0022] S3. The flexible gel is dried and ground to prepare modified silica powder;

[0023] S4. Add the flexible fumed silica powder to the alcohol-water mixture, mix evenly, immerse the fabric in the mixture, and then dry the fabric to obtain the thermal insulation fabric.

[0024] The method for preparing the above-mentioned fabric provided by this invention involves mixing modified silica powder with an alcohol-water mixture and then impregnating the fabric under specific conditions and in a specific ratio. This allows the modified silica powder to completely penetrate all the pores of the fabric and fully combine with the hydroxyl groups on the fabric surface to form hydrogen bonds. The impregnated fabric is then dried at a specific temperature to ensure that the formed hydrogen bonds are not affected, thereby obtaining a thermal insulation fabric with a uniformly impregnated flexible fumed silica surface. This preparation method is simple, uses low-cost raw materials, and has good application prospects.

[0025] In conjunction with the second aspect, the specific reaction conditions described in S1 are: reacting at 40–80°C for 2–3 hours.

[0026] In conjunction with the second aspect, the soaking conditions described in S2 are: soaking at 20-30°C for 4-5 hours.

[0027] In conjunction with the second aspect, the impregnation described in S4 specifically involves: mixing the modified silica powder with an alcohol-water mixture at a ratio of 1 g of modified silica powder per 150-200 mL of alcohol-water mixture; then impregnating the fabric in the mixture of modified silica powder and alcohol-water at a mass ratio of 1:30-40 (modified silica powder: fabric) for 2-6 hours at a temperature of 30-40°C.

[0028] In conjunction with the second aspect, the drying described in S4 is drying at 95–105°C for 10–12 hours.

[0029] The beneficial effects of this invention are as follows: The thermal insulation fabric provided by this invention obtains flexible fumed silica with improved flexibility by using a specific organosilicon source and "implanting" nanofibers into the obtained fumed silica; after grinding the flexible fumed silica into powder, it is mixed with an alcohol-water mixture and impregnated with the fabric under specific conditions and in a specific ratio, and then dried at a specific temperature, resulting in a thermal insulation fabric in which modified silica powder and fabric are chemically bonded. This solves the problem that the coating layer formed by fumed silica has poor mechanical properties, is easily crushed, and then separates from the fabric, causing the fabric to lose its thermal insulation effect. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] In the following examples and comparative examples, modified silica powder was impregnated with fabric at a mass ratio of 1:30.

[0032] Example 1

[0033] This embodiment provides a thermal insulation fabric. The composition of the modified silica powder and the thermal insulation fabric are shown in Table 1. The fabric preparation method includes the following steps:

[0034] S1. After mixing organosilicon source, carbon nanofibers, water, acidic catalyst and surfactant, react at 60°C for 2.5 h, keeping the pH at 3-4, then add alkaline catalyst and carry out polycondensation reaction at room temperature, keeping the pH at 6-7, to obtain flexible wet gel.

[0035] S2. The flexible wet gel is placed in a mixture of solubilizer and low surface tension solvent and soaked at 25°C for 4.5 hours to obtain the flexible gel.

[0036] S3. Dry the flexible gel at 100-120℃ for 1.5h, then at 150-170℃ for 1h, and grind it to obtain modified silica powder.

[0037] S4. Add the modified silica powder to the alcohol-water mixture in the specified proportion and mix evenly. Immerse the fabric in the mixture at 30-40°C for 4 hours, and then dry it at 100°C for 11 hours to obtain the thermal insulation fabric.

[0038] Example 2

[0039] This embodiment provides a thermal insulation fabric. The composition of the modified silica powder and the thermal insulation fabric are shown in Table 1. The fabric preparation method includes the following steps:

[0040] S1. After mixing organosilicon source, carbon nanofibers, water, acidic catalyst and surfactant, react at 40°C for 3 hours, keeping the pH at 3-4. Then add alkaline catalyst and carry out polycondensation reaction at room temperature, keeping the pH at 6-7, to obtain flexible wet gel.

[0041] S2. The flexible wet gel is placed in a mixture of solubilizer and low surface tension solvent and soaked at 20°C for 5 hours to obtain the flexible gel.

[0042] S3. Dry the flexible gel at 110-120℃ for 1 hour, then dry it at 150-160℃ for 1 hour, and grind it to obtain modified silica powder.

[0043] S4. Add the modified silica powder to the alcohol-water mixture in the specified proportion and mix evenly. Immerse the fabric in the mixture at 30-40°C for 6 hours, and then dry it at 105°C for 10 hours to obtain the thermal insulation fabric.

[0044] Example 3

[0045] This embodiment provides a thermal insulation fabric. The composition of the modified silica powder and the thermal insulation fabric are shown in Table 1. The fabric preparation method includes the following steps:

[0046] S1. After mixing organosilicon source, carbon nanofibers, water, acidic catalyst and surfactant, react at 80°C for 2 hours, keeping the pH at 3-4. Then add alkaline catalyst and carry out polycondensation reaction at room temperature, keeping the pH at 6-7, to obtain flexible wet gel.

[0047] S2. The flexible wet gel is placed in a mixture of solubilizer and low surface tension solvent and soaked at 30°C for 4 hours to obtain the flexible gel.

[0048] S3. Dry the flexible gel at 100-110℃ for 2 hours, then dry it at 160-170℃ for 1.5 hours, and grind it to obtain modified silica powder.

[0049] S4. Add the modified silica powder to the alcohol-water mixture in the specified proportion and mix evenly. Immerse the fabric in the mixture at 30-40°C for 2 hours, and then dry it at 95°C for 12 hours to obtain the thermal insulation fabric.

[0050] Examples 4-6

[0051] Examples 4-6 provide a thermal insulation fabric. The composition of the modified silica powder and the thermal insulation fabric are shown in Table 1. The fabric preparation method is the same as in Example 1.

[0052] Comparative Examples 1-4

[0053] Comparative Examples 1-4 provide a thermal insulation fabric. The composition of the modified silica powder and the thermal insulation fabric are shown in Table 1. The fabric preparation method is the same as in Example 1.

[0054] Comparative Example 5

[0055] This comparative example provides a thermal insulation fabric. The composition of the modified silica powder and the thermal insulation fabric are the same as those in Example 1, except that the drying temperature in step S4 of the preparation method is 150°C.

[0056] Table 1. Components and weight parts of modified silica powder in Examples 1-6 and Comparative Examples 1-4

[0057]

[0058]

[0059] Test Example 1

[0060] According to the national standard "Determination of thermal and moisture resistance of textiles under steady-state conditions for physiological comfort (evaporative hot plate method)" (GB / T 11048-2018), the thermal resistance of the fabrics obtained in Examples 1-6 and Comparative Examples 1-5 was tested, and the corresponding performance after 10 and 30 washes was tested. The test results are shown in Table 2.

[0061] Table 2 shows the measurement results of the fabrics obtained in Examples 1-6 and Comparative Examples 1-5.

[0062]

[0063] As can be seen from the data in Table 1, the thermal resistance values ​​of the fabrics obtained in Examples 1 to 6 decreased only slightly after 10 and 30 washes compared to before washing, indicating that the thermal insulation fabric provided by the present invention has good thermal insulation performance and that the thermal insulation performance is not affected by the number of washes.

[0064] It should be noted that the thermal insulation performance of the thermal insulation fabric provided by this invention will not change significantly during finishing or use, as long as the temperature during finishing or use does not exceed 110°C. The inventors speculate that this may be related to the possibility that excessively high temperatures may cause the hydrogen bonds between the modified silica powder and the fabric to break. Therefore, it can be concluded that this thermal insulation fabric is mainly used for making iron-free garments.

[0065] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A thermal insulation fabric, characterized in that, The thermal insulation fabric is a fabric impregnated with modified silica powder, wherein the silicon-oxygen bonds on the surface of the modified silica powder combine with the hydroxyl groups on the surface of the fabric layer to form hydrogen bonds. The raw materials required for preparing the modified silica powder include, by weight, the following: The composition includes 20-30 parts of organosilicon source, 10-20 parts of carbon nanofibers, 40-60 parts of water, 0.02-0.2 parts of acidic catalyst, 0.1-0.3 parts of alkaline catalyst, 4-8 parts of solubilizer, 0.05-0.4 parts of surfactant, and 50-80 parts of low surface tension solvent. The organosilicon source includes at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, or vinyldimethylmethoxysilane; the carbon nanofibers have a length of 0.5–2 mm and a diameter of 1–10 nm. The preparation method of the thermal insulation fabric includes the following steps: S1. The organosilicon source, carbon nanofibers, water, acidic catalyst and surfactant are mixed and hydrolyzed, and then an alkaline catalyst is added to carry out a polycondensation reaction to prepare a flexible wet gel. S2. The flexible wet gel is immersed in a mixture of the solubilizer and the low surface tension solvent to prepare the flexible gel; S3. The flexible gel is dried and ground to prepare modified silica powder; S4. Add the modified silica powder to the alcohol-water mixture, mix evenly, immerse the fabric in the mixture, and then dry the fabric to obtain the thermal insulation fabric. S4 refers to drying at 95~105℃ for 10~12 hours.

2. The thermal insulation fabric as described in claim 1, characterized in that, The fabric is pure cotton or a cotton blend.

3. The thermal insulation fabric as described in claim 1, characterized in that, The acidic catalyst includes at least one of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, oxalic acid, or acetic acid; and / or The alkaline catalyst includes ammonia or sodium hydroxide.

4. The thermal insulation fabric as described in claim 1, characterized in that, The solubilizer is an alcohol solvent or an ether solvent.

5. The thermal insulation fabric as described in claim 1, characterized in that, The surfactant includes at least one of alkyl dimethyl hydroxypropyl phosphate betaine, alkyl dimethyl sulfoethyl betaine, alkyl dimethyl sulfopropyl betaine, or sodium dodecyl aminopropionate.

6. The thermal insulation fabric as described in claim 1, characterized in that, The low surface tension solvent includes at least one of n-hexane, n-heptane, n-octane, isopropanol, or chloroform.

7. The method for preparing the fabric as described in claim 1, characterized in that, The specific conditions for the hydrolysis reaction described in S1 are: reaction at 40~80℃ for 2~3 hours; and / or The soaking conditions described in S2 are: soaking at 20~30℃ for 4~5 hours; and / or The impregnation process in S4 specifically involves mixing the modified silica powder with an alcohol-water mixture at a ratio of 1 g of modified silica powder per 150-200 mL of solvent, and then immersing the fabric in the mixture of modified silica powder and alcohol-water at a mass ratio of 1:30-40 (modified silica powder: fabric) for 2-6 hours at 30-40°C.

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