Low-cost silicon dioxide aerogel coating and preparation method thereof

Abstract

The invention discloses a low-cost silicon dioxide aerogel coating and a preparation method thereof, and belongs to the technical field of coatings. The low-cost silicon dioxide aerogel coating is prepared from the following raw materials: glass fiber-based aerogel composite product waste powder, a wetting agent, a thickening agent, a film-forming emulsion, a film-forming auxiliary agent, a defoaming agent and deionized water, raw materials of the glass fiber-based aerogel composite product waste powder comprise leftover materials of silicon dioxide aerogel heat insulation sheets and leftover materials of silicon dioxide aerogel felts. The preparation method of the silicon dioxide aerogel coating provided by the invention is simple in process, the obtained aerogel coating not only improves the defects of poor mechanical property, low adhesive force, poor water resistance and the like of the traditional aerogel coating, but also greatly reduces the cost of the coating, and has a wide market prospect.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a low-cost silica aerogel coating and its preparation method. Background Technology

[0002] With the rapid development of the aerogel industry, glass fiber-based aerogel composite products such as silica aerogel felts and silica aerogel insulation sheets are increasingly widely used in fields such as chemical pipeline insulation and new energy battery insulation, resulting in continuous production growth. In practical applications, to adapt to the shape requirements of pipelines, batteries, and other usage scenarios, aerogel felts and insulation sheets need to be cut and trimmed, inevitably generating a large amount of scrap waste. Currently, these scraps are mostly disposed of through landfill. Because they are inorganic materials containing a large amount of hydrophobic aerogel powder, they are difficult to degrade naturally, posing a potential risk of physical pollution. At the same time, the high cost of waste disposal is also a significant factor contributing to the high price of aerogel products.

[0003] Aerogel coatings, as a new generation of high-performance thermal insulation materials, possess significant advantages in energy-saving applications in construction, industry, and new energy fields due to their nanoscale porous structure and ultra-low thermal conductivity. They are mainly composed of aerogel powder, film-forming emulsions, hollow microspheres, and other functional fillers. The cost of aerogel powder and functional fillers accounts for approximately 70% of the total material cost, as illustrated in patent applications with publication numbers CN107523102A, CN116535909A, and CN103833041A. Although the cost of aerogel coatings has decreased significantly in recent years compared to ten years ago, its price is still several times that of traditional insulation materials, severely restricting its large-scale promotion and application in the thermal insulation field.

[0004] Therefore, developing low-cost aerogel coating preparation technology is of great practical significance for promoting the industrialization and popularization of aerogel coatings. Summary of the Invention

[0005] This invention aims to provide a low-cost aerogel coating and its preparation method. It utilizes the recycling of waste materials from glass fiber-based aerogel composite products such as silica aerogel insulation sheets and silica aerogel mats to prepare aerogel coatings, thereby realizing the resource utilization of waste materials, reducing environmental pollution, and solving the technical problem that the high price of existing aerogel coatings makes it difficult to apply them on a large scale in the field of thermal insulation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A low-cost silica aerogel coating comprises the following raw materials: waste powder of glass fiber-based aerogel composite products, wetting agent, thickener, film-forming emulsion, film-forming aid, defoamer, and deionized water; the raw materials of the waste powder of glass fiber-based aerogel composite products include scraps of silica aerogel insulation sheets and scraps of silica aerogel felts.

[0007] In the preferred embodiment, the low-cost silica aerogel coating comprises, by weight, the following raw materials: 15-30 parts of waste powder from glass fiber-based aerogel composite products, 2-4 parts of wetting agent, 0.5-2 parts of thickener, 20-40 parts of film-forming emulsion, 1-3 parts of film-forming aid, 0.5-2 parts of defoamer, and 40-60 parts of deionized water.

[0008] In a preferred embodiment, the wetting agent is selected from at least one of ionic wetting agents, polycarboxylate wetting agents, or polymeric wetting agents.

[0009] In a preferred embodiment, the thickener is selected from at least one of hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methylcellulose, xanthan gum, chitosan, gelatin, or gum arabic.

[0010] In a preferred embodiment, the film-forming emulsion is selected from at least one of acrylic resin, polyurethane, epoxy resin, cellulose, polyacrylate copolymer emulsion, epoxy resin emulsion, or silicone emulsion.

[0011] In a preferred embodiment, the defoamer is selected from at least one of the following: silicone defoamer, polyether defoamer, silicone-ether mixed defoamer, or mineral oil defoamer.

[0012] In a preferred embodiment, the silica aerogel insulation sheet is a composite of glass fiber and silica aerogel, wherein the silica aerogel content is ≥60%. The thickness of the silica aerogel insulation sheet is 1~5 mm, and it is mainly used in fields such as power battery and energy storage safety, consumer electronics and micro-devices.

[0013] In a further preferred embodiment, the silica aerogel insulation sheet is a hydrophobic aerogel insulation sheet with a thermal conductivity (25 ℃) ≤0.016 W / m·K and a density not exceeding 260 kg / m³. 3 .

[0014] In the preferred embodiment, the silica aerogel felt is a composite of glass fiber and silica aerogel, wherein the silica aerogel content is ≥60%. The thickness of the silica aerogel felt is usually above 10 mm, and it is mainly used in fields such as thermal insulation of industrial high-temperature equipment, fireproofing and heat insulation of transportation, and energy-saving renovation of buildings.

[0015] In a further preferred embodiment, the silica aerogel felt is a hydrophobic aerogel felt with a thermal conductivity (25℃) ≤0.021 W / m·K and a density not exceeding 200 kg / m³. 3 .

[0016] In the preferred embodiment, the mass ratio of silica aerogel insulation sheet to silica aerogel felt in the waste powder of the glass fiber-based aerogel composite product is 1~2:1.

[0017] In the preferred embodiment, the waste powder of the glass fiber-based aerogel composite product is obtained by the following method: thoroughly crushing and mixing the scraps of silica aerogel insulation sheets and silica aerogel felts.

[0018] In a further preferred embodiment, the particle size of the waste powder of the glass fiber-based aerogel composite product is 20~100um.

[0019] The method for preparing the low-cost silica aerogel coating includes the following steps: S1. Weigh the raw materials according to the weight proportions of each component, and add the thickener, wetting agent, film-forming aid, film-forming emulsion, and defoamer to the deionized water in sequence. S2. Add the waste powder of glass fiber-based aerogel composite product to the mixed solution of S1 and stir evenly to obtain the final product.

[0020] In the preferred embodiment, in step S1, a thickener is added to deionized water, a wetting agent is added after the thickener is mixed, a film-forming aid is added after the wetting agent is mixed, a film-forming emulsion is added after the film-forming emulsion is mixed, and an antifoaming agent is added after the film-forming emulsion is mixed.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses silica aerogel insulation sheets and silica aerogel felt scraps to prepare aerogel coatings, which solves the problems of difficult recycling and treatment of aerogel, and helps to reduce the environmental pollution caused by waste from glass fiber-based aerogel composite products.

[0022] 2. The aerogel scraps used in this invention contain a large amount of glass fiber, which can significantly increase the mechanical strength and adhesion of the coating and effectively improve the problem of easy cracking of aerogel coatings. Therefore, it is not necessary to add functional fillers such as hollow glass microspheres, making the preparation process simpler.

[0023] 3. This invention uses silica aerogel insulation sheets and silica aerogel felt scraps to prepare aerogel coatings, without the need to add additional functional fillers such as aerogel powder and hollow microspheres. Therefore, it can significantly reduce the cost of aerogel coatings and effectively improve the waterproof performance of aerogel coatings. Detailed Implementation

[0024] The technical solution of the present invention will be further described and illustrated below through examples. All raw materials used in the examples are commercially available or prepared using conventional methods.

[0025] The silica aerogel insulation sheet used in the following embodiments is a composite of glass fiber and silica aerogel, with a thickness of 1-5 mm. It is mainly used in power batteries and energy storage safety, consumer electronics and micro-devices, etc. The silica aerogel insulation sheet is a hydrophobic aerogel insulation sheet with a thermal conductivity (25 ℃) ≤0.016 W / m·K and a density not exceeding 260 kg / m³. 3 The silica aerogel felt used is a composite of glass fiber and silica aerogel, typically with a thickness of 10 mm or more. It is mainly used in industrial high-temperature equipment insulation, transportation fireproofing and heat insulation, and building energy-saving renovation. The silica aerogel felt is a hydrophobic aerogel felt with a thermal conductivity (25℃) ≤0.021 W / m·K and a density not exceeding 200 kg / m³. 3 In the following examples, the waste powder of glass fiber-based aerogel composite products is obtained by crushing the scraps of silica aerogel insulation sheets and silica aerogel felts to a particle size of 50 μm and then mixing them at a mass ratio of 1:1.

[0026] Example 1 A low-cost silica aerogel coating comprises, by weight, the following raw materials: 15 parts of waste powder from glass fiber-based aerogel composite products, 2 parts of Nopco 5040 wetting agent, 1 part of methyl cellulose thickener, 30 parts of Badifu FS230 film-forming emulsion, 2 parts of dodecyl alcohol ester film-forming aid, 1 part of BYK-024 waterborne silicone defoamer, and 40 parts of deionized water.

[0027] The method for preparing the low-cost silica aerogel coating includes the following steps: S1. Weigh the raw materials according to the weight proportions of each component. Add the next raw material to the water in sequence, stirring until it is evenly mixed. Add the thickener, wetting agent, film-forming aid, film-forming emulsion, and defoamer to the deionized water respectively. S2. Add the waste powder of glass fiber-based aerogel composite product to the mixed solution of S1 and stir evenly to obtain the final product.

[0028] Example 2 A low-cost silica aerogel coating comprises, by weight, the following raw materials: 20 parts of waste powder from glass fiber-based aerogel composite products, 2.5 parts of Nopco 5040 wetting agent, 1 part of methylcellulose thickener, 30 parts of Badifu FS230 film-forming emulsion, 2 parts of dodecyl alcohol ester film-forming aid, 1 part of BYK-024 waterborne silicone defoamer, and 50 parts of deionized water.

[0029] The preparation method of the low-cost silica aerogel coating is consistent with that in Example 1.

[0030] Example 3 A low-cost silica aerogel coating comprises, by weight, the following raw materials: 25 parts of waste powder from glass fiber-based aerogel composite products, 3 parts of Nopco 5040 wetting agent, 1 part of methyl cellulose thickener, 30 parts of Badifu FS230 film-forming emulsion, 2 parts of dodecyl alcohol ester film-forming aid, 1 part of BYK-024 waterborne silicone defoamer, and 55 parts of deionized water.

[0031] The preparation method of the low-cost silica aerogel coating is consistent with that in Example 1.

[0032] Example 4 A low-cost silica aerogel coating comprises, by weight, the following raw materials: 30 parts of waste powder from glass fiber-based aerogel composite products, 4 parts of Nopco 5040 wetting agent, 1 part of methylcellulose thickener, 30 parts of Badifu FS230 film-forming emulsion, 2 parts of dodecyl alcohol ester film-forming aid, 1 part of BYK-024 waterborne silicone defoamer, and 60 parts of deionized water.

[0033] The preparation method of the low-cost silica aerogel coating is consistent with that in Example 1.

[0034] Comparative Example 1 A silica aerogel coating, by weight parts, comprises: 3 parts aerogel powder, 2 parts Nopco 5040 wetting agent, 1 part methylcellulose thickener, 30 parts Badifu FS230 film-forming emulsion, 2 parts dodecyl alcohol ester film-forming aid, 1 part BYK-024 waterborne silicone defoamer, 18 parts hollow glass microspheres, and 50 parts deionized water; The aerogel powder is a hydrophobic silica aerogel powder, a white powdery solid with a thermal conductivity (25℃) ≤0.015 W / m·K, D90=50 μm, and a specific surface area ≥600 m². 2 / g); the hollow glass microspheres are 3MS S15 hollow microspheres.

[0035] The silica aerogel coating is prepared by the following steps: S1. Weigh the raw materials and add them in order. Add one raw material to water and stir evenly before adding the next raw material. Add 1 part thickener, 2 parts wetting agent, 2 parts film-forming aid, 30 parts film-forming emulsion, and 1 part defoamer to 50 parts of deionized water respectively. S2. Add 3 parts of aerogel powder to the mixed solution in S1 and stir until homogeneous; S3. Add 18 portions of hollow glass microspheres to the mixing system of step S2 and stir until homogeneous to obtain the final product.

[0036] Comparative Example 2 A silica aerogel coating, by weight parts, comprises: 5 parts aerogel powder, 3 parts Nopco 5040 wetting agent, 1 part methylcellulose thickener, 30 parts Badifu FS230 film-forming emulsion, 2 parts dodecyl alcohol ester film-forming aid, 1 part BYK-024 waterborne silicone defoamer, 14 parts hollow glass microspheres, and 55 parts deionized water; The aerogel powder is a hydrophobic silica aerogel powder, a white powdery solid with a thermal conductivity (25℃) ≤0.015 W / m·K, D90=50 μm, and a specific surface area ≥600 m². 2 / g); the hollow glass microspheres are 3MS S15 hollow microspheres.

[0037] The preparation method of the silica aerogel coating is the same as that of Comparative Example 1.

[0038] Comparative Example 3 A silica aerogel coating, by weight parts, comprises: 8 parts aerogel powder, 4 parts Nopco 5040 wetting agent, 1 part methylcellulose thickener, 30 parts Badifu FS230 film-forming emulsion, 2 parts dodecyl alcohol ester film-forming aid, 1 part BYK-024 waterborne silicone defoamer, 10 parts hollow glass microspheres, and 60 parts deionized water; The aerogel powder is a hydrophobic silica aerogel powder, a white powdery solid with a thermal conductivity (25℃) ≤0.015 W / m·K, D90=50 μm, and a specific surface area ≥600 m². 2 / g); the hollow glass microspheres are 3MS S15 hollow microspheres.

[0039] The preparation method of the silica aerogel coating is the same as that of Comparative Example 1.

[0040] Testing and Analysis The properties of the coatings in Examples 1-4 and Comparative Examples 1-3 are shown in Table 1.

[0041] Table 1 Coating Performance Data

[0042] As can be seen from Table 1, the low-cost silica aerogel coatings prepared in Examples 2 to 4 of the present invention have good comprehensive performance.

[0043] As can be seen from Examples 1-4, the thermal conductivity and adhesion of the aerogel coating gradually decrease with the increase of waste powder from the glass fiber-based aerogel composite product. This is because the waste powder from the glass fiber-based aerogel composite product contains a large amount of aerogel powder with low thermal conductivity; as its proportion increases, the thermal conductivity of the coating system also gradually decreases. However, as the proportion of waste powder from the glass fiber-based aerogel composite product gradually increases, the proportion of the film-forming emulsion also gradually decreases, thus the adhesion of the coating system also gradually decreases.

[0044] As can be seen from Comparative Examples 1 to 3, the thermal conductivity of the comparative coating systems is generally high. This is because hollow glass microspheres with high thermal conductivity are introduced into the system.

[0045] It should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A low-cost silica aerogel coating, characterized in that, The raw materials include: waste powder of glass fiber-based aerogel composite products, wetting agent, thickener, film-forming emulsion, film-forming aid, defoamer and deionized water; the raw materials of the waste powder of glass fiber-based aerogel composite products include scraps of silica aerogel insulation sheets and scraps of silica aerogel felt.

2. The low-cost silica aerogel coating according to claim 1, characterized in that, The low-cost silica aerogel coating comprises, by weight, the following raw materials: 15-30 parts of waste powder from glass fiber-based aerogel composite products, 2-4 parts of wetting agent, 0.5-2 parts of thickener, 20-40 parts of film-forming emulsion, 1-3 parts of film-forming aid, 0.5-2 parts of defoamer, and 40-60 parts of deionized water.

3. The low-cost silica aerogel coating according to claim 1, characterized in that, The silica aerogel insulation sheet is a composite of glass fiber and silica aerogel, wherein the silica aerogel content is ≥60%; the silica aerogel felt is a composite of glass fiber and silica aerogel, wherein the silica aerogel content is ≥60%.

4. The low-cost silica aerogel coating according to claim 3, characterized in that, The silica aerogel insulation sheet is a hydrophobic aerogel insulation sheet with a thermal conductivity (25 ℃) ≤0.016 W / m·K and a density not exceeding 260 kg / m³. 3 The silica aerogel felt is a hydrophobic aerogel felt with a thermal conductivity (25℃) ≤0.021 W / m·K and a density not exceeding 200 kg / m³. 3 .

5. The low-cost silica aerogel coating according to claim 1, characterized in that, The mass ratio of silica aerogel insulation sheet to silica aerogel felt in the waste powder of the glass fiber-based aerogel composite product is 1~2:

1.

6. The low-cost silica aerogel coating according to claim 1, characterized in that, The waste powder of the glass fiber-based aerogel composite product is prepared by the following method: the scraps of silica aerogel insulation sheet and silica aerogel felt are thoroughly crushed and then mixed.

7. The low-cost silica aerogel coating according to claim 6, characterized in that, In a further preferred embodiment, the particle size of the waste powder of the glass fiber-based aerogel composite product is 20~100 μm.

8. The low-cost silica aerogel coating according to claim 1, characterized in that, The wetting agent is selected from at least one of ionic wetting agents, polycarboxylate wetting agents, or polymeric wetting agents; the thickener is selected from at least one of hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methylcellulose, xanthan gum, chitosan, gelatin, or gum arabic; the film-forming emulsion is selected from at least one of acrylic resin, polyurethane, epoxy resin, cellulose, polyacrylate copolymer emulsion, epoxy resin emulsion, or silicone emulsion; and the defoamer is selected from at least one of silicone defoamer, polyether defoamer, silicone-ether mixed defoamer, or mineral oil defoamer.

9. A method for preparing a low-cost silica aerogel coating as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Weigh the raw materials according to the weight proportions of each component, and add the thickener, wetting agent, film-forming aid, film-forming emulsion, and defoamer to the deionized water in sequence. S2. Add the waste powder of glass fiber-based aerogel composite product to the mixed solution of S1 and stir evenly to obtain the final product.

10. The method for preparing the low-cost silica aerogel coating according to claim 9, characterized in that, In step S1, a thickener is added to deionized water, a wetting agent is added after the thickener is mixed, a film-forming aid is added after the wetting agent is mixed, a film-forming emulsion is added after the film-forming emulsion is mixed, and an antifoaming agent is added after the film-forming emulsion is mixed.

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