Nanofiller dispersion process for organic silicon aerogel coating

Abstract

The invention relates to the field of nano-filler dispersion, and discloses a nano-filler dispersion process for an organic silicon aerogel coating, which comprises the following steps: S1, nano-filler pretreatment: carrying out surface activation treatment on a nano-filler by adopting low-temperature plasma in an inert gas atmosphere, then adding the nano-filler into a silane coupling agent modifier solution, and reacting for 2-4 hours to obtain a nano-filler dispersion solution; then carrying out vacuum drying to obtain a surface modified nano filler; s2, pre-dispersing step by step; s3, mixing and finally dispersing the matrix resin; s4, regulation and control of dispersion stability; and S5, preparing the organic silicon aerogel coating. Compared with the prior art, the preparation method has the advantages that an efficient and stable dispersion process is realized, and the dispersity and the coating performance of the nanofiller are remarkably improved through multi-stage dispersion means such as low-temperature plasma pretreatment, step-by-step pre-dispersion and high-pressure homogenization.

Description

Technical Field

[0001] This invention relates to the field of nanofiller dispersion technology, specifically to a nanofiller dispersion process for organosilicon aerogel coatings. Background Technology

[0002] Organosilicon aerogel coatings possess excellent thermal insulation, fire resistance, and corrosion resistance properties, making them promising for applications in construction, aerospace, energy, and chemical industries. Nanofillers, as a crucial component of organosilicon aerogel coatings, can effectively improve coating performance, such as enhancing strength, toughness, and thermal insulation. However, due to their small particle size, large specific surface area, and high surface energy, nanofillers are prone to agglomeration in coating systems, leading to uneven dispersion and thus affecting coating performance.

[0003] Currently, commonly used methods for dispersing nanofillers include mechanical stirring, ultrasonic dispersion, and chemical modification. While mechanical stirring can achieve a certain degree of dispersion, it is often difficult to achieve ideal dispersion results for materials like nanofillers that are prone to agglomeration. Although ultrasonic dispersion can effectively break up agglomerates of nanofillers using cavitation effects, using ultrasonic dispersion alone may result in uneven dispersion. Chemical modification involves modifying the surface of nanofillers to reduce their surface energy, thereby improving their dispersibility in coating systems. However, chemical modification processes are usually quite complex and may introduce impurities that affect the performance of the coating. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned technical difficulties and provide a nanofiller dispersion process for organosilicon aerogel coatings, so as to achieve efficient and stable dispersion. Through multi-stage dispersion methods such as low-temperature plasma pretreatment, stepwise pre-dispersion, and high-pressure homogenization, the dispersibility and coating performance of nanofillers are significantly improved.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is: a nanofiller dispersion process for organosilicon aerogel coatings, comprising the following steps:

[0006] S1. Pretreatment of nanofillers: The nanofillers are surface activated by low-temperature plasma in an inert gas atmosphere, and then added to a silane coupling agent modifier solution and reacted for 2-4 hours. After vacuum drying, surface-modified nanofillers are obtained.

[0007] S2. Stepwise pre-dispersion: The surface-modified nanofiller is added in batches to a base resin system that is a mixture of a portion of silicone resin and a diluent. After each addition, high-speed shear dispersion and intermittent ultrasonic treatment are performed sequentially to obtain a primary dispersion slurry of the nanofiller.

[0008] S3. Mixing and final dispersion of the main resin: The primary dispersion slurry is mixed with the remaining organosilicon resin, and after being mixed by low-speed planetary stirring, it is then subjected to high-pressure homogenization dispersion to obtain a uniformly dispersed nanofiller-organosilicon resin dispersion system.

[0009] S4. Dispersion stability control: After adding stabilizer and stirring, let stand to obtain a stable dispersion system;

[0010] S5. Preparation of organosilicon aerogel coating: The dispersion system is mixed with organosilicon aerogel particles and curing agent to obtain organosilicon aerogel nanocomposite coating.

[0011] As an improvement, the power of the low-temperature plasma treatment in step S1 is 200-800W, and the treatment time is 5-30 minutes; the silane coupling agent modifier solution is prepared by silane coupling agent, ethanol and deionized water in a mass ratio of 1:(5-8):(1-2), the modification temperature is 50-80℃, the vacuum drying temperature is 60-80℃, and the vacuum degree is ≤-0.09MPa.

[0012] As an improvement, the silane coupling agent mentioned in step S1 is one of KH-550, KH-560, and KH-570, and its mass is 1% to 5% of the mass of the nanofiller.

[0013] As an improvement, in step S2, the rotation speed of the high-speed shear dispersion is 2000-4000 rpm, and the time is 5-15 minutes; the power of the intermittent ultrasonic treatment is 400-600W, and the mode of working for 2-4 seconds and intermittent for 1-2 seconds is adopted, with a total time of 3-10 minutes; the nanofiller is added in 2-4 times.

[0014] As an improvement, in step S3, the planetary mixer has an orbital speed of 20-50 rpm, a rotational speed of 1000-2000 rpm, and a mixing time of 20-40 minutes; the high-pressure homogenization pressure is 80-150 MPa, and the process is repeated 3-5 times.

[0015] As an improvement, the stabilizer is organic bentonite or fumed silica, with an addition amount of 0.5-1.0 wt%, a standing temperature of 25-30℃, and an agglomeration rate of ≤5% after the dispersion system has been standing for 72 hours.

[0016] As an improvement, in step S5, the mass ratio of the dispersion system to the organosilicon aerogel particles is (2-3):1, the curing agent is dibutyltin dilaurate, and the amount added is 1% to 2% of the mass of the organosilicon resin.

[0017] As an improvement, the nanofiller is one or more of nano-silica, nano-alumina, nano-zinc oxide, nano-silicon carbide, and boron nitride nanosheets.

[0018] As an improvement, the silicone resin is a hydrolyzed prepolymer of methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), tetraethyl orthosilicate (TEOS), or a copolymer thereof.

[0019] (III) Beneficial Effects

[0020] The advantages of this invention compared with the prior art are as follows: by pretreating with low-temperature plasma, the surface energy of the nanofiller is efficiently activated without introducing impurities, which greatly increases the reactive sites on its surface, providing a solid foundation for the subsequent chemical grafting of silane coupling agents, and fundamentally improving the interfacial compatibility between the nanofiller and the organosilicon resin. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1

[0023] A nanofiller dispersion process for organosilicon aerogel coatings includes the following steps:

[0024] S1. Pretreatment of nanofillers: The nanofillers are surface activated by low-temperature plasma in an inert gas atmosphere, then added to a silane coupling agent modifier solution and reacted for 2 hours, followed by vacuum drying to obtain surface-modified nanofillers. The power of the low-temperature plasma treatment is 200W and the treatment time is 5 minutes. The silane coupling agent modifier solution is prepared by silane coupling agent, ethanol and deionized water in a mass ratio of 1:5:1, with a modification temperature of 50℃, a vacuum drying temperature of 60℃ and a vacuum degree ≤-0.09MPa.

[0025] The silane coupling agent is one of KH-550, KH-560, and KH-570, and its mass is 1% to 5% of the mass of the nanofiller. The nanofiller is one or more of nano-silica, nano-alumina, nano-zinc oxide, nano-silicon carbide, and boron nitride nanosheets. The organosilicon resin is a hydrolyzed prepolymer of methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), or tetraethyl orthosilicate (TEOS) or a copolymer thereof.

[0026] S2. Stepwise pre-dispersion: The surface-modified nanofiller is added in batches to a base resin system consisting of a mixture of organosilicon resin and diluent. After each addition, high-speed shear dispersion and intermittent ultrasonic treatment are performed sequentially to obtain a primary dispersion slurry of nanofiller. The high-speed shear dispersion is performed at a speed of 2000-4000 rpm for 5 minutes. The intermittent ultrasonic treatment is performed at a power of 400W, using a mode of 2 seconds of operation followed by 1 second of intermittent operation, for a total time of 3 minutes. The nanofiller is added in two steps.

[0027] S3. Mixing and final dispersion of the main resin: The primary dispersion slurry is mixed with the remaining organosilicon resin, and after being mixed by low-speed planetary stirring, it is then subjected to high-pressure homogenization dispersion to obtain a uniformly dispersed nanofiller-organosilicon resin dispersion system. The planetary stirring has an orbital speed of 20 rpm, a rotational speed of 1000 rpm, and a mixing time of 20 minutes. The high-pressure homogenization pressure is 80 MPa, and the process is repeated 35 times.

[0028] S4. Dispersion stability control: After adding stabilizer and stirring, let stand to obtain a stable dispersion system;

[0029] S5. Preparation of organosilicon aerogel coating: The dispersion system is mixed with organosilicon aerogel particles and curing agent to obtain organosilicon aerogel nanocomposite coating.

[0030] The stabilizer is organic bentonite or fumed silica, with an addition amount of 0.5 wt%. After standing at 25°C, the agglomeration rate of the dispersion system is ≤5% after standing for 72 hours.

[0031] In step S5, the mass ratio of the dispersion system to the organosilicon aerogel particles is 2:1, the curing agent is dibutyltin dilaurate, and the amount added is 1% of the mass of the organosilicon resin.

[0032] Example 2

[0033] Based on Example 1, a nanofiller dispersion process for organosilicon aerogel coatings includes the following steps:

[0034] S1. Pretreatment of nanofillers: The nanofillers are surface activated by low-temperature plasma in an inert gas atmosphere, and then added to a silane coupling agent modifier solution and reacted for 4 hours. After vacuum drying, surface-modified nanofillers are obtained. The power of the low-temperature plasma treatment is 800W and the treatment time is 30 minutes. The silane coupling agent modifier solution is prepared by silane coupling agent, ethanol and deionized water in a mass ratio of 1:6):1. The modification temperature is 60℃, the vacuum drying temperature is 70℃ and the vacuum degree is ≤-0.09MPa.

[0035] The silane coupling agent is one of KH-550, KH-560, and KH-570, and its mass is 1% to 5% of the mass of the nanofiller. The nanofiller is one or more of nano-silica, nano-alumina, nano-zinc oxide, nano-silicon carbide, and boron nitride nanosheets. The organosilicon resin is a hydrolyzed prepolymer of methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), or tetraethyl orthosilicate (TEOS) or a copolymer thereof.

[0036] The stabilizer is organobentonite or fumed silica, with an addition amount of 0.5-1.0 wt%, a standing temperature of 25-30℃, and an agglomeration rate of ≤5% after the dispersion system has stood for 72 hours. The nanofiller is one or more of nano-silica, nano-alumina, nano-zinc oxide, nano-silicon carbide, and boron nitride nanosheets. The organosilicon resin is a hydrolyzed prepolymer of methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), or tetraethyl orthosilicate (TEOS) or a copolymer thereof.

[0037] S2. Stepwise pre-dispersion: The surface-modified nanofiller is added in batches to a base resin system consisting of a mixture of organosilicon resin and diluent. After each addition, high-speed shear dispersion and intermittent ultrasonic treatment are performed sequentially to obtain a primary dispersion slurry of the nanofiller. The high-speed shear dispersion is performed at a speed of 3000 rpm for 10 minutes. The intermittent ultrasonic treatment is performed at a power of 400-600W, using a mode of 3 seconds of operation followed by 2 seconds of intermittent operation, for a total time of 8 minutes. The nanofiller is added in 2-4 batches.

[0038] S3. Mixing and final dispersion of the main resin: The primary dispersion slurry is mixed with the remaining organosilicon resin, and after being mixed by low-speed planetary stirring, it is then subjected to high-pressure homogenization dispersion to obtain a uniformly dispersed nanofiller-organosilicon resin dispersion system. The planetary stirring has an orbital speed of 20-50 rpm, a rotational speed of 1500 rpm, and a mixing time of 30 minutes. The high-pressure homogenization pressure is 110 MPa, and the process is repeated 4 times.

[0039] S4. Dispersion stability control: After adding the stabilizer and stirring, the system is allowed to stand to obtain a stable dispersion system. The stabilizer is organic bentonite or fumed silica, with an addition amount of 0.7 wt%. The standing temperature is 28℃. After the dispersion system stands for 72 hours, the agglomeration rate is ≤5%.

[0040] S5. Preparation of organosilicon aerogel coating: The dispersion system is mixed with organosilicon aerogel particles and curing agent to obtain organosilicon aerogel nanocomposite coating. The mass ratio of the dispersion system to organosilicon aerogel particles is 2.5:1. The curing agent is dibutyltin dilaurate, and the amount added is 1.5% of the mass of organosilicon resin.

[0041] Example 3

[0042] A nanofiller dispersion process for organosilicon aerogel coatings includes the following steps:

[0043] S1. Pretreatment of Nanofillers: The nanofillers are surface activated using low-temperature plasma in an inert gas atmosphere, then added to a silane coupling agent modifier solution and reacted for 4 hours, followed by vacuum drying to obtain surface-modified nanofillers. The power of the low-temperature plasma treatment is 800W, and the treatment time is 30 minutes. The silane coupling agent modifier solution is prepared by mixing silane coupling agent, ethanol, and deionized water in a mass ratio of 1:8:2. The modification temperature is 80℃, the vacuum drying temperature is 80℃, and the vacuum degree is ≤-0.09MPa. The silane coupling agent is one of KH-550, KH-560, and KH-570, and its mass is 1% to 5% of the mass of the nanofillers.

[0044] S2. Stepwise pre-dispersion: The surface-modified nanofiller is added in batches to a base resin system consisting of a mixture of organosilicon resin and diluent. After each addition, high-speed shear dispersion and intermittent ultrasonic treatment are performed sequentially to obtain a primary dispersion slurry of the nanofiller. The high-speed shear dispersion is performed at a speed of 4000 rpm for 15 minutes. The intermittent ultrasonic treatment is performed at a power of 600W, using a mode of 4 seconds of operation followed by 2 seconds of intermittent operation, for a total time of 10 minutes. The nanofiller is added in 4 batches.

[0045] S3. Mixing and final dispersion of the main resin: The primary dispersion slurry is mixed with the remaining organosilicon resin, and after being mixed by low-speed planetary stirring, it is then subjected to high-pressure homogenization dispersion to obtain a uniformly dispersed nanofiller-organosilicon resin dispersion system. The planetary stirring has an orbital speed of 50 rpm, a rotational speed of 2000 rpm, and a mixing time of 40 minutes. The high-pressure homogenization pressure is 150 MPa, and the process is repeated 5 times.

[0046] S4. Dispersion stability control: After adding stabilizer and stirring, a stable dispersion system is obtained. The mass ratio of the dispersion system to the organosilicon aerogel particles is 3:1. The curing agent is dibutyltin dilaurate, and the amount added is 1% to 2% of the mass of organosilicon resin.

[0047] S5. Preparation of organosilicon aerogel coating: The dispersion system is mixed with organosilicon aerogel particles and curing agent to obtain organosilicon aerogel nanocomposite coating.

[0048] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description in the specification. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0051] The present invention and its embodiments have been described above. This description is not restrictive, and the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the scope of protection of this invention.

Claims

1. A nanofiller dispersion process for organosilicon aerogel coatings, characterized in that, Includes the following steps: S1. Pretreatment of nanofillers: The nanofillers are surface activated by low-temperature plasma in an inert gas atmosphere, and then added to a silane coupling agent modifier solution and reacted for 2-4 hours. After vacuum drying, surface-modified nanofillers are obtained. S2. Stepwise pre-dispersion: The surface-modified nanofiller is added in batches to a base resin system that is a mixture of a portion of silicone resin and a diluent. After each addition, high-speed shear dispersion and intermittent ultrasonic treatment are performed sequentially to obtain a primary dispersion slurry of the nanofiller. S3. Mixing and final dispersion of the main resin: The primary dispersion slurry is mixed with the remaining organosilicon resin, and after being mixed by low-speed planetary stirring, it is then subjected to high-pressure homogenization dispersion to obtain a uniformly dispersed nanofiller-organosilicon resin dispersion system. S4. Dispersion stability control: After adding stabilizer and stirring, let stand to obtain a stable dispersion system; S5. Preparation of organosilicon aerogel coating: The dispersion system is mixed with organosilicon aerogel particles and curing agent to obtain organosilicon aerogel nanocomposite coating.

2. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1, characterized in that, The power of the low-temperature plasma treatment in step S1 is 200-800W, and the treatment time is 5-30 minutes; the silane coupling agent modifier solution is prepared by silane coupling agent, ethanol and deionized water in a mass ratio of 1:(5-8):(1-2), the modification temperature is 50-80℃, the vacuum drying temperature is 60-80℃, and the vacuum degree is ≤-0.09MPa.

3. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1 or 2, characterized in that, The silane coupling agent mentioned in step S1 is one of KH-550, KH-560, and KH-570, and its mass is 1% to 5% of the mass of the nanofiller.

4. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1, characterized in that, In step S2, the high-speed shear dispersion is performed at a rotation speed of 2000-4000 rpm for 5-15 minutes; the intermittent ultrasonic treatment is performed at a power of 400-600W, using a mode of working for 2-4 seconds and intermittent for 1-2 seconds, for a total time of 3-10 minutes; and the nanofiller is added in 2-4 batches.

5. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1, characterized in that, In step S3, the planetary mixer has a revolution speed of 20-50 rpm, a rotation speed of 1000-2000 rpm, and a mixing time of 20-40 minutes; the high-pressure homogenization pressure is 80-150 MPa, and the process is repeated 3-5 times.

6. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1, characterized in that, The stabilizer is organic bentonite or fumed silica, with an addition amount of 0.5-1.0 wt%, a standing temperature of 25-30℃, and an agglomeration rate of ≤5% after the dispersion system has been standing for 72 hours.

7. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1, characterized in that, In step S5, the mass ratio of the dispersion system to the organosilicon aerogel particles is (2-3):1, the curing agent is dibutyltin dilaurate, and the amount added is 1% to 2% of the mass of the organosilicon resin.

8. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1, characterized in that, The nanofiller is one or more of nano-silica, nano-alumina, nano-zinc oxide, nano-silicon carbide, and boron nitride nanosheets.

9. The nanofiller dispersion process for organosilicon aerogel coatings according to claim 1, characterized in that, The organosilicon resin is a hydrolyzed prepolymer of methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), tetraethyl orthosilicate (TEOS), or a copolymer thereof.