Aerogel thermal insulation paste for high-transmittance glass film and preparation method thereof

Abstract

The present application relates to the technical field of functional slurry, more particularly to an aerogel heat insulation slurry for high-transmittance glass film and a preparation method and application thereof.The raw materials of the slurry include low-thermal-conductivity aerogel fine particles with a content of 0.1wt%-2wt%, diarsenic trioxide with a content of 0.1wt%-2wt%, tungsten trioxide with a content of 0.5wt%-2wt%, antimony tin oxide with a content of 0.1wt%-2wt%, cesium tungstate with a content of 10wt%-30wt%, a dispersant with a content of 1wt%-3wt%, and the rest is a mixed solvent.The present application widens the infrared light absorption spectrum of the composite nanoceramic filler by using spectral complementation, and synergistically improves the infrared barrier capability.The dispersant and nanoceramic filler are added to the solvent and dispersed to obtain an aerogel heat insulation composite slurry with low thermal conductivity, high infrared barrier property and uniform stability.

Description

Technical Field

[0001] This invention relates to the field of functional paste technology, and more specifically, to aerogel heat-insulating paste for high-transmittance glass films and its preparation method and application. Background Technology

[0002] With the rapid development of society and the economy, energy consumption has increased rapidly, leading to a series of environmental problems such as global warming and air pollution. Heat-insulating window film primarily blocks heat generated by infrared rays in sunlight, thereby reducing the temperature inside vehicles or homes and decreasing the energy required for air conditioning. To realize the practical application value of the product, the heat-insulating film needs to ensure transmittance in the visible light region and blocking of infrared light. Among various heat-insulating materials, inorganic ceramic films, which selectively absorb infrared light and block heat, are not easily oxidized and deactivated, have a long service life, and, unlike metal heat-insulating films, do not interfere with radio signals, making them a superior choice for producing high-transmittance heat-insulating automotive films. However, the development of its heat-insulating paste remains challenging.

[0003] Currently, some researchers have conducted studies in this field. Chinese invention patent CN115676839A describes a method for preparing an aerogel slurry. This method involves high-speed dispersion of a nano-stabilizer and aerogel powder to obtain an aerogel slurry. While this material possesses certain thermal insulation properties, its narrow infrared absorption band limits its practical application. Chinese invention patent CN115108758 describes a method for preparing an aerogel insulation material. This method involves mixing an adhesive, sol, fiber, and aerogel particles and stirring until homogeneous to obtain an aerogel insulation slurry. However, the aerogel particles in this slurry are unevenly distributed, and prolonged standing causes stratification, severely weakening its thermal insulation performance. Chinese invention patent CN15873290A describes a method for preparing a silicone aerogel slurry. This method involves adding a thickener to a prepared silicone aerogel emulsion and stirring until homogeneous to obtain a silicone aerogel slurry. However, this method uses a single raw material, and the resulting glass film has low visible light transmittance, limiting its application in various fields. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one aspect of the present invention is to provide an aerogel thermal insulation slurry for high-transmittance glass films. The slurry raw materials include 0.1wt% to 2wt% of low thermal conductivity aerogel fine particles, 0.1wt% to 2wt% of arsenic trioxide, 0.5wt% to 2wt% of tungsten trioxide, 0.1wt% to 2wt% of antimony tin oxide, 10wt% to 30wt% of cesium tungstate, 1wt% to 3wt% of dispersant, and the balance being a mixed solvent.

[0005] Another objective of this invention is to provide a method for preparing an aerogel heat-insulating slurry for high-transmittance glass films, the specific steps of which are as follows: S1. The low thermal conductivity ceramic aerogel particle dispersion system was subjected to high-energy grinding, high-frequency ultrasonication, centrifugation and drying treatment in sequence to obtain low thermal conductivity aerogel refined particles with an average particle size of <200nm. S2. The low thermal conductivity aerogel refined particles prepared in S1 are mixed with arsenic trioxide, tungsten trioxide, antimony tin oxide and cesium tungstate in a certain proportion to obtain a composite nano-ceramic filler with a wide infrared absorption spectrum. S3. The thermal insulation slurry dispersant and the composite nano-ceramic filler prepared in S2 are placed in the thermal insulation slurry solvent and dispersed to obtain aerogel thermal insulation composite slurry with low thermal conductivity, high infrared barrier properties, and uniform stability.

[0006] Preferably, the low thermal conductivity ceramic aerogel particle dispersion system in S1 is composed of a dispersed phase, a dispersion medium, and a dispersant in a mass ratio of 30:40:1; the dispersed phase is any one of silica, zirconium oxide, aluminum silicate, or other inorganic ceramic materials, with a thermal conductivity <0.024 W / (m·K) and a porosity of 80~99%; the dispersion medium is ethanol; and the dispersant is one or more combinations of polyvinyl alcohol, sodium dodecylbenzenesulfonate, hexamethylenediamine, diacetone alcohol, polydimethylsiloxane, or other surfactants.

[0007] Preferably, the high-energy grinding instrument used in S1 is a grinding machine, with grinding balls of 2mm, 4mm or 8mm in size, a ball-to-material ratio of 700~200:1, a grinding speed of 200rpm~500rpm, and a grinding time of 1h~12h.

[0008] Preferably, in step S1, the instrument used for high-frequency ultrasound is an ultrasonic machine with an ultrasonic frequency of 80kHz to 120kHz and an ultrasonic time of 1h to 3h; the instrument used for centrifugation is a centrifuge with a centrifugation speed of 4000rpm to 6000rpm and a centrifugation time of 4h to 6h; and the instrument used for drying is an oven with a drying time of 2h to 6h and a drying temperature of 80°C.

[0009] Preferably, the mass ratio of the low thermal conductivity aerogel refined particles, arsenic trioxide, tungsten trioxide, antimony tin oxide and cesium tungstate in S2 is 0.3~6:0.3~6:1.5~6:0.3~6:30~90.

[0010] Preferably, the mass ratio of the thermal insulation slurry dispersant, the composite nano-ceramic filler, and the thermal insulation slurry solvent in S3 is 1~3:10~40:60~90.

[0011] Preferably, the heat insulation slurry dispersant in S3 is one or more of polyethylene glycol, dipropylene glycol methyl ether, dipropylene glycol butyl ether, ethylenediamine, hexamethylenediamine, isocyanate, polydimethylsiloxane, polyoxypropylene ethylene glycol glycerol ether, isophorone, diacetone alcohol, or other surfactants; the heat insulation slurry solvent is one or more of acetone, ethanol, toluene, or other organic solvents.

[0012] Preferably, the instrument used for dispersion treatment in S3 is a high-speed disperser with a rotation speed of 1000 rpm to 2000 rpm and a dispersion time of 1 h to 3 h.

[0013] Another aspect of the present invention is to provide an application of an aerogel heat-insulating paste for high-transmittance glass films, wherein the aerogel heat-insulating paste is blended with acrylic resin and used as a heat-insulating layer material for solar heat-insulating glass films, wherein the resin has a solid content of 30wt% to 50wt% and the resin to heat-insulating paste are mixed in a mass ratio of 6:1 to 4:1.

[0014] The aerogel thermal insulation slurry of this invention is prepared by mixing and dispersing a refined low thermal conductivity aerogel particle dispersion, a semiconductor oxide with spectral synergistic effect, a dispersant, and a solvent in a certain proportion. After sequentially subjecting the dispersion to high-energy grinding, high-frequency ultrasonication, centrifugation, and drying, the average particle size of the aerogel particles is significantly reduced (<200nm) while maintaining a good mesoporous structure, thereby increasing the specific surface area of ​​the particles and improving thermal insulation performance. Subsequently, various semiconductor oxides such as arsenic trioxide, tungsten trioxide, antimony tin oxide, and cesium tungstate are added to obtain a composite nano-ceramic filler. The infrared absorption spectrum of the ceramic filler is synergistically broadened using spectral complementarity. Finally, the composite nano-ceramic filler and dispersant are placed in a solvent and dispersed to obtain an aerogel thermal insulation composite slurry with low thermal conductivity, high infrared barrier properties, and uniform stability.

[0015] The aerogel thermal insulation slurry for high-transmittance glass films prepared by this invention differs from traditional aerogel thermal insulation slurries. Traditional aerogel thermal insulation slurries are made by directly mixing aerogel particles, solvents, and dispersants. This material suffers from problems such as large particle size, uneven dispersion of aerogel particles, and easy collapse of the pore structure after refinement, limiting its practical application. This invention utilizes high-energy grinding, high-frequency ultrasound, centrifugation, and drying to significantly reduce the aerogel particle size (<200nm) while maintaining the integrity of the mesoporous structure. The glass film prepared from the aerogel thermal insulation slurry of this invention has a thermal conductivity ≤0.1W / (m·K), greatly expanding its application in the field of building thermal insulation. Existing thermal insulation slurries suffer from drawbacks such as complex preparation processes and narrow infrared absorption ranges. The aerogel thermal insulation slurry of this invention, by adding various semiconductor oxides, utilizes the complementary effect of multi-component spectra to synergistically enhance its infrared blocking ability. Furthermore, the glass film prepared from the aerogel thermal insulation slurry of this invention has advantages such as simple preparation process, large infrared absorption bandwidth, and good transparency.

[0016] The beneficial effects of this invention are as follows: This invention involves sequentially subjecting a low thermal conductivity ceramic aerogel dispersion to high-energy grinding, high-frequency ultrasonication, centrifugation, and drying to obtain aerogel particles with an average particle size <200nm. These particles are then combined with inorganic nanomaterials such as arsenic trioxide, tungsten trioxide, antimony tin oxide, and cesium tungstate. The spectral complementarity of these nanomaterials broadens the infrared absorption spectrum of the composite ceramic filler, synergistically enhancing its infrared blocking ability. The dispersant and ceramic filler are added to a solvent and dispersed to obtain a uniform and stable aerogel thermal insulation composite slurry with low thermal conductivity, high infrared blocking, and high stability. This slurry can be used as the insulation layer of solar thermal insulation glass films. Glass films prepared from this invention achieve a thermal conductivity ≤0.1W / (m·K), an infrared blocking rate ≥60%, and a visible light transmittance ≥70%.

[0017] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is the ultraviolet absorption spectrum of the composite heat insulation slurry film containing 0.1 wt% silica aerogel prepared in Example 2 of the present invention; Figure 2 These are SEM images of untreated silica aerogel particles in Embodiment 2 of the present invention; Figure 3 These are SEM images of the silica aerogel particles after refinement in Embodiment 2 of the present invention; Figure 4 This is the refinement control curve of silica aerogel particles in Embodiment 2 of the present invention; Figure 5 This is the ultraviolet absorption spectrum of the composite heat insulation slurry film containing 0.3 wt% silica aerogel prepared in Example 3 of the present invention. Detailed Implementation

[0019] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below. Example 1

[0021] Step 1: Preparation of composite nanofillers without silica aerogel Take 0.2g of arsenic trioxide, 0.3g of tungsten trioxide, 0.3g of antimony tin oxide, and 28g of cesium tungstate, and mix them to form a nanofiller with infrared absorption properties.

[0022] Step 2: Preparation of insulation slurry without silica aerogel 40g of composite nanofiller and 1g of mixed surfactant (50wt% polyethylene glycol, 40wt% ethylenediamine and 10wt% isocyanate) were dispersed together in ethanol solvent and then dispersed by a high-speed disperser at 1000rpm for 3h to obtain a blue heat-insulating slurry. Example 2

[0023] Step 1: Refinement of low thermal conductivity silica aerogel particle dispersion system 3g of silica aerogel particles were mixed with 0.1g of hexamethylenediamine and dispersed in 4g of ethanol to obtain a silica aerogel particle dispersion. The dispersion was then subjected to high-energy grinding using a grinder with grinding balls of 4mm and 8mm in size, a ball-to-particle ratio of 500:1, a grinding speed of 400rpm, and a grinding time of 4h. Subsequently, the dispersion was treated with an ultrasonic machine at a frequency of 90kHz for 1.5h. Finally, the dispersion was centrifuged at a speed of 4000rpm for 5h to obtain silica aerogel particles with an average particle size of 180nm.

[0024] SEM images comparing silica aerogel particles before and after grinding and refining are shown below. Figure 2 and Figure 3 As shown, the particle refinement control curves for silica aerogel particles are as follows: Figure 4 As shown.

[0025] Step 2: Preparation of silica aerogel composite nanofillers 0.2 g of refined silica aerogel particles were mixed with 0.2 g of arsenic trioxide, 0.3 g of tungsten trioxide, 0.3 g of antimony tin oxide, and 28 g of cesium tungstate to form a silica aerogel composite nanofiller with broad and strong infrared absorption. Compared with existing thermal insulation aerogel membranes, this characteristic synergistically results in high infrared absorption efficiency, which is beneficial for preparing thermal insulation film materials with high transparency.

[0026] Step 3: Preparation of 0.1wt% silica aerogel insulation slurry 40g of composite nano-ceramic filler and 1g of a mixed surfactant (50wt% polyethylene glycol, 40wt% ethylenediamine, and 10wt% isocyanate) were dispersed together in ethanol solvent, and then dispersed using a high-speed disperser at 1000rpm for 3h to obtain silica aerogel insulation slurry. The slurry was a blue liquid with good stability; the static settling time of the insulation slurry, measured by a sedimentation meter, was ≥3 days, and the settling rate was ≤40%. Figure 1 The image shows the UV absorption spectrum of the heat insulation slurry containing 0.1 wt% silica aerogel prepared in this embodiment. The silica aerogel heat insulation slurry was prepared into a transparent heat insulation film by a scraping method. An LS101 solar film heat insulation tester determined its infrared blocking rate to be ~81% and its visible light transmittance to be 76%, results that are superior to the performance of currently reported aerogel heat insulation films. Example 3

[0027] Step 1: Refinement of low thermal conductivity silica aerogel particle dispersion system 3g of silica aerogel particles were mixed with 0.1g of hexamethylenediamine and dispersed in 4g of ethanol to obtain a silica aerogel particle dispersion. The dispersion was then subjected to high-energy grinding using a grinder with grinding balls of 4mm and 8mm in size, a ball-to-particle ratio of 500:1, a grinding speed of 400rpm, and a grinding time of 4h. Subsequently, the dispersion was treated with an ultrasonic machine at a frequency of 90kHz for 1.5h. Finally, the dispersion was centrifuged at a speed of 4000rpm for 5h to obtain silica aerogel particles with an average particle size of 180nm.

[0028] Step 2: Preparation of silica aerogel composite nanofillers 0.6 g of refined silica aerogel particles were mixed with 0.2 g of arsenic trioxide, 0.3 g of tungsten trioxide, 0.3 g of antimony tin oxide, and 28 g of cesium tungstate to form a silica aerogel composite nanofiller with broad and strong infrared absorption. Compared with existing thermal insulation aerogel membranes, this characteristic synergistically results in high infrared absorption efficiency, which is beneficial for preparing thermal insulation film materials with high transparency.

[0029] Step 3: Preparation of 0.3wt% silica aerogel thermal insulation slurry 40g of composite nano-ceramic filler and 1g of a mixed surfactant (50wt% polyethylene glycol, 40wt% ethylenediamine, and 10wt% isocyanate) were dispersed together in ethanol solvent, followed by dispersion using a high-speed disperser at 1000rpm and centrifugation for 3h to obtain a silica aerogel insulation slurry. The slurry was a blue liquid with good stability; the static settling time was ≥3 days and the settling rate was ≤40%, as measured by a sedimentation meter. The silica aerogel insulation slurry was then used to prepare a transparent insulation film using a blade coating method. An LS101 solar film insulation tester determined its infrared rejection rate to be ~85% and its visible light transmittance to be 72%, results that are superior to currently reported aerogel insulation film performance. Figure 5 The image shows the UV absorption spectrum of the heat insulation slurry film containing 0.3 wt% silica aerogel prepared in this embodiment. Example 4

[0030] Step 1: Refinement of the low thermal conductivity zirconia aerogel particle dispersion system 6g of zirconia aerogel particles were mixed with 0.2g of polyvinyl alcohol and dispersed in 8g of ethylene glycol to obtain a silica aerogel particle dispersion. The dispersion was then subjected to high-energy grinding using a grinder with grinding balls of 2mm, 4mm, and 8mm in size, a ball-to-particle ratio of 700:1, a grinding speed of 500rpm, and a grinding time of 3h. Subsequently, the dispersion was subjected to high-frequency ultrasonication at a frequency of 80kHz for 1h. Finally, the dispersion was centrifuged at a speed of 5000rpm for 6h to obtain zirconia aerogel particles with an average particle size of 170nm.

[0031] Step 2: Preparation of Zirconia Aerogel Composite Nanofiller Take 0.1g of refined zirconia aerogel particles, and mix them with 0.3g of arsenic trioxide, 0.1g of tungsten trioxide, 0.1g of antimony tin oxide, and 30g of cesium tungstate to form a zirconia aerogel composite nanofiller with broad and strong infrared absorption.

[0032] Step 3: Preparation of Zirconia Aerogel Insulation Paste 35g of composite nano-ceramic filler and 2g of a mixed surfactant (40wt% isocyanate, 10wt% diacetone alcohol, and 50wt% polyethylene glycol) were dispersed together in an acetone / toluene mixed solvent, and then dispersed using a high-speed disperser at 2000 rpm for 1 hour to obtain a zirconia aerogel thermal insulation slurry. The zirconia aerogel thermal insulation slurry was then coated onto a film to obtain a transparent thermal insulation film. The infrared rejection rate was measured to be ~65% and the visible light transmittance to be 78% using an LS101 solar film thermal insulation tester. These results are significantly higher than the performance indicators currently reported for aerogel thermal insulation slurries. Example 5

[0033] Step 1: Refinement of low thermal conductivity aluminosilicate aerogel particle dispersion 9g of zirconia aerogel particles, 0.1g of polyvinyl alcohol, and 0.2g of hexamethylenediamine were mixed and dispersed in 12g of ethanol to obtain a silica aerogel particle dispersion. The dispersion was then subjected to high-energy grinding using a grinder with 8mm grinding balls at a ball-to-particle ratio of 600:1, a grinding speed of 300rpm, and a grinding time of 7h. Subsequently, the dispersion was subjected to high-frequency ultrasonication at a frequency of 110kHz for 3h. Finally, the dispersion was centrifuged at 600rpm for 4h to obtain aluminosilicate aerogel particles with an average particle size of 160nm.

[0034] Step 2: Preparation of aluminum silicate aerogel composite nanofillers Take 0.3g of finely granulated aluminum silicate aerogel particles, and mix them with 0.3g of arsenic trioxide, 0.2g of tungsten trioxide, 0.3g of antimony tin oxide, and 40g of cesium tungstate to form an aluminum silicate aerogel composite nanofiller with broad and strong infrared absorption.

[0035] Step 3: Preparation of aluminum silicate aerogel insulation slurry 40g of composite nano-ceramic filler and 1g of mixed surfactant (70wt% hexamethylenediamine, 15wt% isophorone, and 15wt% polydimethylsiloxane) were dispersed together in an ethanol / acetone mixed solvent, and then dispersed using a high-speed disperser at 1000rpm for 3h to obtain aluminum silicate aerogel thermal insulation slurry. The aluminum silicate aerogel thermal insulation slurry was then used to prepare a transparent thermal insulation film using a blade coating method. An LS101 solar film thermal insulation tester determined that its infrared blocking rate was ~71% and its visible light transmittance was 75%, results that are superior to the performance of currently reported aerogel thermal insulation films.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A method for preparing an aerogel insulating paste for high-transmittance glass films, characterized in that: The slurry raw materials include 0.1wt%~2wt% low thermal conductivity aerogel fine particles, 0.1wt%~2wt% arsenic trioxide, 0.5wt%~2wt% tungsten trioxide, 0.1wt%~2wt% tin antimony oxide, 10wt%~30wt% cesium tungstate, 1wt%~3wt% dispersant, and the balance being solvent; The specific steps of the preparation method are as follows: S1. The low thermal conductivity ceramic aerogel particle dispersion system was subjected to high-energy grinding, high-frequency ultrasonication, centrifugation and drying treatment in sequence to obtain low thermal conductivity aerogel refined particles with an average particle size of <200nm. S2. The low thermal conductivity aerogel refined particles prepared in S1 are mixed with arsenic trioxide, tungsten trioxide, antimony tin oxide and cesium tungstate in proportion to obtain a composite nano-ceramic filler with a wide infrared absorption spectrum. S3. The thermal insulation slurry dispersant and the composite nano-ceramic filler prepared in S2 are placed in the thermal insulation slurry solvent and dispersed to obtain aerogel thermal insulation composite slurry with low thermal conductivity, high infrared barrier properties, and uniform stability. The dispersant in the thermal insulation slurry in S3 is one or more of the following: polyethylene glycol, dipropylene glycol methyl ether, dipropylene glycol butyl ether, ethylenediamine, hexamethylenediamine, isocyanate, polydimethylsiloxane, polyoxypropylene ethylene glycol glycerol ether, isophorone, diacetone alcohol, or other surfactants; the solvent in the thermal insulation slurry is one or more of the following: organic solvents. The dispersion process in S3 uses a high-speed disperser with a rotation speed of 1000 rpm to 2000 rpm and a dispersion time of 1 h to 3 h.

2. The method for preparing an aerogel heat-insulating slurry for high-transmittance glass films according to claim 1, characterized in that: The low thermal conductivity ceramic aerogel particle dispersion system in S1 consists of a dispersed phase, a dispersion medium, and a dispersant in a mass ratio of 30:40:

1. The dispersed phase is silica, zirconium oxide, or aluminum silicate, with a thermal conductivity of <0.024 W / (m·K) and a porosity of 80-99%. The dispersion medium is ethanol. The dispersant is one or more combinations of polyvinyl alcohol, sodium dodecylbenzenesulfonate, hexamethylenediamine, diacetone alcohol, or polydimethylsiloxane.

3. The method for preparing an aerogel heat-insulating slurry for high-transmittance glass films according to claim 1, characterized in that: The high-energy grinding in S1 uses a grinding machine with grinding balls of 2mm, 4mm or 8mm in size, a ball-to-material ratio of 700~200:1, a grinding speed of 200rpm~500rpm, and a grinding time of 1h~12h.

4. The method for preparing an aerogel heat-insulating slurry for high-transmittance glass films according to claim 1, characterized in that: The instrument used for high-frequency ultrasound in S1 is an ultrasonic machine with an ultrasonic frequency of 80kHz~120kHz and an ultrasonic time of 1h~3h; the instrument used for centrifugation is a centrifuge with a centrifugation speed of 4000rpm~6000rpm and a centrifugation time of 4h~6h; the instrument used for drying is an oven with a drying time of 2h~6h and a drying temperature of 80°C.

5. The method for preparing an aerogel heat-insulating slurry for high-transmittance glass films according to claim 1, characterized in that: The mass ratio of the low thermal conductivity aerogel refined particles, arsenic trioxide, tungsten trioxide, antimony tin oxide and cesium tungstate in S2 is 0.3~6:0.3~6:1.5~6:0.3~6:30~90.

6. The method for preparing an aerogel heat-insulating slurry for high-transmittance glass films according to claim 1, characterized in that: The mass ratio of the thermal insulation slurry dispersant, the composite nano-ceramic filler, and the thermal insulation slurry solvent in S3 is 1~3:10~40:60~90.

7. The application of the aerogel heat-insulating paste for high-transmittance glass film according to claim 1, characterized in that: The aerogel heat insulation slurry is blended with acrylic resin and used as the heat insulation layer material of solar heat insulation glass film. The resin has a solid content of 30wt% to 50wt% and the mass ratio of resin to heat insulation slurry is 6:1 to 4:1.

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