Carbon material coating adhesive, its preparation method and application

Abstract

This invention relates to the field of thermal field system coatings, specifically to carbon material coating adhesives, their preparation methods, and applications. The carbon material coating adhesive provided by this invention achieves full-chain synergy from "raw materials - preparation - coating - reaction - detection," with multi-stage purification ensuring cleanliness from the source; polyether modification + functional phase gradation + stepwise ultrasonication solving dispersion and cracking problems; interface grafting + plasma etching strengthening adhesion; boron powder catalysis + gradient high temperature improving conversion rate; and scene-customized coating adaptable to different working conditions, forming a complete logical chain of "ultra-cleanliness → high dispersion → strong adhesion → crack resistance → high conversion → scene adaptability." Ultimately, it achieves performance indicators of "metal ion ≤ 1.5 ppm, coating adhesion ≥ 4.5 MPa, SiC conversion rate ≥ 95%, and weight loss rate ≤ 0.15% at 550℃ / 8h," fully meeting the long-term protection requirements of high-end scenarios such as single-crystal silicon thermal fields and TSSG method SiC single-crystal growth.

Description

Technical Field

[0001] This invention relates to the field of thermal field system coatings, specifically to carbon material coating adhesives, their preparation methods, and applications. Background Technology

[0002] Carbon materials (such as graphite, carbon-carbon composites, and carbon fiber insulation materials) have become core materials for single-crystal silicon thermal field systems, semiconductor SiC single-crystal growth crucibles (a core component of the TSSG method), and aerospace high-temperature components due to their excellent high-temperature stability, mechanical properties, and thermal conductivity. However, these materials face two major challenges during service: first, they are easily oxidized at high temperatures, leading to surface pulverization and degradation of mechanical properties; second, during the Czochralski growth of single-crystal silicon or the growth of single-crystal SiC, the silicon vapor and molten silicon splashes generated by the melting silicon material can cause silicide corrosion, severely shortening the service life of components.

[0003] Specifically, in the monocrystalline silicon photovoltaic power generation industry, the thermal field system is the core component for monocrystalline silicon growth, mainly composed of carbon materials such as graphite, carbon-carbon composites, and carbon fiber insulation. As the size of monocrystalline silicon continues to increase, higher demands are placed on the dimensional stability, mechanical properties, and service life of the thermal field components. However, during the Czochralski process of growing monocrystalline silicon, silicon vapor and molten silicon splashes generated from the melting silicon material can lead to silicification and erosion of the carbon materials. Simultaneously, the carbon materials are easily oxidized under high-temperature conditions, severely affecting their mechanical properties and service life.

[0004] Silicon carbide (SiC) coatings are the preferred solution for surface protection of carbon materials due to their excellent thermal shock resistance, wear resistance, resistance to silicon vapor corrosion, and oxidation resistance. They can effectively isolate corrosive media such as air and silicon vapor from contact with the substrate, extending the service life of hot-field components. Currently, the main methods for preparing silicon carbide coatings include embedding, slurry coating, chemical vapor reaction (CVR), and chemical vapor deposition (CVD). Among them, slurry coating is widely used in laboratories and industrial production due to its simple operation, easy control of coating thickness, and low cost. Its general process is "substrate pretreatment → coating slurry preparation → coating → drying and curing → high-temperature sintering". The core is to prepare a slurry with coating materials and binders, apply it to the substrate surface, and fix the coating powder to the substrate surface using binders. After drying and high-temperature sintering, a dense protective coating is formed.

[0005] However, existing slurry coating methods and related coating adhesives have significant technical bottlenecks: First, there is a risk of impurity introduction. Some solutions add metal impurities such as yttrium oxide or silica sol (the main component of SiO2). Metal impurities contaminate the single-crystal silicon growth process, and SiO2 reacts with carbon fibers at high temperatures, causing fiber oxidation and corrosion. Second, the bonding-dispersion system design is fragmented, lacking a dedicated synergistic formula, resulting in poor slurry stability, easy powder agglomeration, and weak bonding between the coating and the substrate. Third, although some solutions avoid impurity introduction, the synergistic mechanism between components is not clearly defined. Issues such as the stability of carbon source supply and the balance of slurry viscosity and dispersibility have not been thoroughly addressed, leaving room for optimization. Fourth, the coating is prone to powdering and cracking, and its oxidation resistance is insufficient, failing to meet the long-term protection requirements of hot-field components.

[0006] Therefore, developing a dedicated silicon carbide coating adhesive that is "impurity-free + synergistic bonding and dispersion" has become an urgent industry need. Among existing slurry systems, the "phenolic resin + Si powder + alcohol" system has gradually become a research hotspot due to the high volatility of alcohol, absence of residual moisture, and good compatibility with organic resins. It avoids problems such as substrate hygroscopicity and decreased interfacial adhesion between the coating and substrate caused by water-based systems. However, this system suffers from functional fragmentation of its components, lacks synergistic design, does not consider stress buffering and interfacial bonding optimization, lacks impurity control design, and has insufficient dispersibility, adhesion, and crack resistance. Specifically, it exhibits the following significant technical bottlenecks: 1. Traditional phenolic resins are brittle and have limited compatibility with alcohol dispersion, which leads to easy agglomeration of Si powder, poor slurry stability, uneven coating composition, and high porosity after coating.

[0007] 2. Phenolic resin and carbon matrix are only physically adsorbed and bonded together, resulting in weak interfacial bonding. After high-temperature carbothermic reduction, it is easy to peel off and fall off, especially in crucibles, guide tubes and other parts subjected to stress or airflow.

[0008] 3. Phenolic resin has a high curing shrinkage rate (≥5%), and there is about 20% volume change when Si powder reacts with resin residual carbon to form SiC. It lacks a stress buffering mechanism, and the coating is prone to through cracks. Corrosive media can penetrate into the substrate through the cracks.

[0009] Therefore, developing solutions for the traditional "phenolic resin + alcohol + Si powder" system to address the core defects of the existing system has become an urgent need for high-end applications such as single-crystal silicon thermal fields and semiconductor SiC single-crystal growth. Summary of the Invention

[0010] In view of this, the technical problem to be solved by the present invention is to provide a carbon material coating adhesive, its preparation method and application. The carbon material coating adhesive provided by the present invention has good uniformity, and the resulting coating has significant advantages in adhesion, crack resistance and cleanliness, which can meet the long-term protection requirements and can provide targeted protection for different protection scenarios.

[0011] In a first aspect of the invention, a carbon material coating adhesive is provided, comprising, by weight percentage: Alcohol solvent: 18%~25%; Functional reinforcing phase material: 42%~52%, wherein the functional reinforcing phase material comprises micron-sized Si powder, nano-sized Si powder and SiC whiskers in a mass ratio of (7~8):(2~3):1; Polyether-modified phenolic resin: 20%~28%; Composite additives: 3%~7%, wherein the composite additives include 0.2%~0.4% boron powder catalyst, 0.5%~1% ether dispersant, 2%~5% anti-cracking agent and 0.3%~0.6% silane coupling agent, wherein the ether dispersant is selected from one or more of polyethylene glycol alkyl aryl ethers and alkyl polyoxyolefin ethers.

[0012] In a second aspect of the invention, a carbon material coating adhesive is provided, comprising, by weight percentage: Alcohol solvent: 18%~25%; Functional reinforcing phase material: 42%~52%, wherein the functional reinforcing phase material comprises micron-sized Si powder, nano-sized Si powder and SiC whiskers in a mass ratio of (7~8):(2~3):1; Polyether-modified phenolic resin: 20%~28%; Composite additives: 3%~7%, wherein the composite additives include 0.2%~0.4% boron powder catalyst, 0.5%~1% ether dispersant, 2%~5% polyether modified phenolic resin coated nano-Si powder and 0.3%~0.6% silane coupling agent, wherein the ether dispersant is selected from one or more of polyethylene glycol alkyl aryl ethers and alkyl polyoxyolefin ethers.

[0013] The carbon material coating adhesive provided in the first and second aspects of this invention has a viscosity of 130 mPa at 24°C to 26°C. s~170 mPa Furthermore, the sedimentation rate is ≤1%. The total metal ion content of the carbon material coating adhesive provided in the first and second aspects of the present invention is ≤1.5 ppm.

[0014] The carbon material coating adhesive provided in the first aspect of the present invention can be used as a general-purpose coating adhesive, and is preferably suitable for coating devices other than crucibles used in TSSG SiC single crystal growth, such as thermal insulation covers and flow guides; while the carbon material coating adhesive provided in the second aspect of the present invention is specifically used for coating crucibles used in TSSG SiC single crystal growth. The difference between the carbon material coating adhesives provided in the first and second aspects of the present invention is that the composite additives in the carbon material coating adhesive of the first aspect include anti-cracking additives but do not include polyether-modified phenolic resin-coated nano-Si powder, while the composite additives in the carbon material coating adhesive of the second aspect include polyether-modified phenolic resin-coated nano-Si powder but do not include anti-cracking additives.

[0015] The anti-cracking agent described in the first aspect of this invention is selected from one or more of amorphous boron powder, boric acid, boron carbide, nano-silica, and nano-alumina. In some embodiments of this invention, the anti-cracking agent is selected from amorphous boron powder with a particle size of 2 μm to 4 μm and a purity of 99.5% or higher.

[0016] The polyether-modified phenolic resin-coated nano-Si powder of the second aspect of the present invention comprises a nano-Si powder core and a polyether-modified phenolic resin wall layer coating the surface of the nano-Si powder core; wherein the mass percentage of the nano-Si powder core is 70% to 80%; the particle size of the polyether-modified phenolic resin-coated nano-Si powder is 5 μm to 10 μm; and the thickness of the polyether-modified phenolic resin wall layer is 0.5 μm to 1 μm. The polyether-modified phenolic resin wall layer of this invention is obtained by curing a polyether-modified phenolic resin grafted with phenolic resin with a molecular weight of 800 Da to 1200 Da and polyethylene glycol with a molecular weight of 5000 Da to 7000 Da at a mass ratio of (8 to 10):1. More specifically, it is obtained by stirring phenolic resin with a molecular weight of 800 Da to 1200 Da and polyethylene glycol with a molecular weight of 5000 Da to 7000 Da at a mass ratio of (8 to 10):1 in a reaction vessel at a constant temperature of 115°C to 125°C for 1.5 h to 2.5 h; the residual carbon rate of the phenolic resin is 45% to 55%.

[0017] The preparation method of polyether-modified phenolic resin-coated nano-Si powder according to the second aspect of the present invention includes: mixing and curing a nano-Si powder core material dispersion with a mass ratio of 70% to 80% and a polyether-modified phenolic resin wall material solution with a mass ratio of 20% to 30% to obtain polyether-modified phenolic resin-coated nano-Si powder; the curing specifically involves: heating to 55℃ to 65℃, stirring at a constant temperature for 2.5 h to 3.5 h, then heating to 85℃ to 95℃, and continuing to stir for 1.5 h to 2.5 h to allow the wall material to fully cure and crosslink.

[0018] The nano-Si powder core material dispersion of the present invention is obtained by mixing and dispersing nano-Si powder, surfactant, and alcohol solvent. The particle size of the nano-Si powder is 50 nm to 100 nm, preferably 70 nm to 80 nm. The surfactant is selected based on its ability to suppress the particle size of nano-Si powder agglomerates ≤5 μm after dispersion, preferably polyethylene glycol alkyl aryl ether, more preferably polyethylene glycol octylphenyl ether. The alcohol solvent is preferably ethanol. The amount of nano-Si powder used is 70 g to 80 g and the amount of surfactant used is 0.3 g to 0.5 g per 100 mL of alcohol solvent. In some embodiments of the present invention, 70 g to 80 g of nano-Si powder, 0.3 g to 0.5 g of polyethylene glycol octylphenyl ether, and 100 mL of anhydrous ethanol are mixed and dispersed to obtain the nano-Si powder core material dispersion.

[0019] The polyether-modified phenolic resin wall material solution of the present invention is obtained by mixing and dispersing polyether-modified phenolic resin, a curing agent, and an alcohol solvent. The polyether-modified phenolic resin is the same as described above and will not be repeated. The curing agent is preferably hexamethylenetetramine; the alcohol solvent is preferably ethanol. The amount of polyether-modified phenolic resin used is 20 g to 30 g, based on 200 mL to 400 mL of anhydrous ethanol, and the mass of the curing agent accounts for 8% to 10% of the mass of the polyether-modified phenolic resin. In some embodiments of the present invention, 20 g to 30 g of polyether-modified phenolic resin, 1.6 g to 3 g of hexamethylenetetramine, and 200 mL to 400 mL of anhydrous ethanol are mixed and dispersed to obtain the polyether-modified phenolic resin wall material solution.

[0020] In the carbon material coating adhesive provided by the first aspect of the present invention, the alcohol solvent, the functional reinforcing phase material, the polyether-modified phenolic resin, the boron powder catalyst in the composite additive, the ether dispersing agent in the composite additive, and the silane coupling agent in the composite additive are all the same as those in the carbon material coating adhesive provided by the second aspect.

[0021] Specifically, in the carbon material coating adhesive of this invention, the alcohol solvent is selected from one or more of ethanol, isopropanol, n-propanol, propylene glycol, and isobutanol. Its core function is to disperse the carrier, dissolve the modified phenolic resin, and leave no residual moisture. The alcohol solvent of this invention is preferably selected from anhydrous ethanol, more preferably from a purity ≥99.9%, moisture ≤0.05%, impurities ≤0.01%, and obtained through molecular distillation (80℃ / 10... -3 Anhydrous ethanol purified by Pa; high-purity ethanol avoids the introduction of impurities, and molecular distillation removes trace amounts of moisture and organic impurities, making it suitable for semiconductor-grade cleanliness requirements.

[0022] In the carbon material coating adhesive of this invention, the core function of the functional reinforcing phase material is to provide a Si source, enhancing the mechanical properties and wear resistance of the coating. The micron-nano gradation design of the Si powder optimizes the stability of the slurry. It preferably comprises micron-sized Si powder, nano-sized Si powder, and SiC whiskers in a mass ratio of 7:2:1. The amount of SiC whiskers added is strictly controlled to 10% of the total mass of Si powder to avoid stress concentration due to excessive addition. The micron-sized Si powder has a particle size of 5 μm to 20 μm; the nano-sized Si powder has a particle size of 50 nm to 100 nm; and the SiC whiskers have a diameter of 0.5 μm to 2 μm and a length of 10 μm to 30 μm. The micron-nano Si powder gradation increases the packing density, and the SiC whiskers form a three-dimensional reinforcing network, synergistically improving the coating strength and erosion resistance. The functional reinforcing phase material of this invention is purified by acid washing and plasma cleaning to eliminate impurity contamination. In some embodiments of the present invention, the purity of the micron-sized Si powder is ≥99.99%, and the metal ion content is ≤1 ppm; the purity of the nano-sized Si powder is ≥99.99%, and the metal ion content is ≤0.5 ppm; the purity of the SiC whiskers is ≥99.99%, and the metal ion content is ≤0.5 ppm.

[0023] In the carbon material coating adhesive of this invention, the polyether-modified phenolic resin serves as the main binder and carbon source, its core function being to act as both a binder and a carbon source, improving the system's dispersibility and flexibility. It is obtained by grafting phenolic resin with a molecular weight of 800 Da~1200 Da and polyethylene glycol with a molecular weight of 5000 Da~7000 Da at a mass ratio of (8~10):1. More specifically, it is obtained by grafting phenolic resin with a molecular weight of 800 Da~1200 Da and polyethylene glycol with a molecular weight of 5000 Da~7000 Da at a mass ratio of (8~10):1 in a reaction vessel at a constant temperature of 115℃~125℃ for 1.5 h~2.5 h, preferably at a mass ratio of 9:1. The residual carbon rate of the phenolic resin is 45%~55%. In some embodiments of this invention, the metal ion content of the polyether-modified phenolic resin is ≤0.8 ppm, and its ethanol solubility is ≥98%. The polyether segment can reduce the resin curing shrinkage rate (from ≥5% to ≤2%) and improve compatibility with alcohol solvents and nano-Si powder; the residual carbon rate is adapted to the reaction requirements of nano-Si powder to ensure sufficient carbothermic reduction.

[0024] In the carbon material coating adhesive of the present invention, the core function of the composite additive is to accelerate the carbothermic reduction reaction, optimize the dispersion stability of the slurry, and enhance the interfacial bonding. In the second aspect, the unique polyether-modified phenolic resin-coated nano-Si powder in the carbon material coating adhesive can achieve slow pyrolysis at high temperature to realize the slow release of Si source, limiting the fluctuation of the Si source release rate of the coating formed to ≤5% in the TSSG method SiC single crystal growth, so as to meet the single crystal stable growth requirements of the coating of the crucible used for TSSG method SiC single crystal growth.

[0025] Furthermore, in the carbon material coating adhesive described in the first and second aspects of this invention, the boron powder catalyst can reduce the reaction activation energy, and its addition amount is limited to 0.2%~0.4%, which ensures both an increased reaction rate and avoids residual impurities. The boron powder catalyst is preferably an impurity-free catalyst; more preferably, the particle size of the boron powder catalyst is 1 μm~3 μm; the purity of the boron powder catalyst is ≥99.95%, and the metal ion content is ≤0.3 ppm.

[0026] Furthermore, in the carbon material coating adhesive described in the first and second aspects of this invention, the ether-based dispersant not only adsorbs onto the surface of Si powder to inhibit agglomeration, but also works synergistically with the polyether-modified phenolic resin to achieve a sedimentation rate of ≤1% after 30 minutes of standing, which is far superior to the traditional system (≥8%). The ether-based dispersant is preferably selected from one or more of polyethylene glycol octylphenyl ether, octylphenol polyoxyethylene ether, and nonylphenol polyoxyethylene ether, and more preferably from polyethylene glycol octylphenyl ether with a purity ≥99% and free of metal impurities.

[0027] Furthermore, in the carbon material coating adhesive described in the first and second aspects of the present invention, the silane coupling agent enables chemical bonding between the polyether-modified phenolic resin and the matrix. The silane coupling agent is preferably selected from one or more of KH-550 (γ-aminopropyltriethoxysilane), KH-560 (γ-glycidyl etheroxypropyltrimethoxysilane), KH-570 (γ-(methacryloyloxy)propyltrimethoxysilane), and KH-792 (N-(β-aminoethyl)-γ-aminopropyltrimeth(eth)oxysilane), more preferably from KH-550 which is impurity-free and has metal ion concentrations ≤0.5 ppm.

[0028] The carbon material coating adhesives provided by this invention, in both aspects, abandon the water system and use alcohol solvents, especially ethanol, as solvents. Combined with polyether-modified phenolic resin, they improve interfacial compatibility with the substrate, solving the problems of substrate hygroscopicity and weak interfacial adhesion, resulting in coating adhesion ≥3.0 MPa and preventing peeling and powdering at high temperatures. Furthermore, both utilize micron-nano gradation of Si powder and SiC whisker design, combined with the synergistic dispersion effect of polyether-modified phenolic resin and ether-based dispersants, to optimize slurry stability, solve the Si powder agglomeration problem, achieve a slurry settling rate ≤1%, uniform coating composition, and porosity ≤0.5%, realizing composite reinforcement-dispersion synergy. In addition, the residual carbon distribution and reactivity of the polyether-modified phenolic resin are optimized, increasing the contact area between Si powder and the carbon source, improving SiC conversion rate to ≥95%, and lowering the carbonization reaction temperature, thereby improving protective performance while reducing energy consumption. Specifically, the carbon material coating adhesive described in the first aspect utilizes the flexible segments of polyether-modified phenolic resin to reduce curing shrinkage, and, in conjunction with anti-cracking agents, alleviates internal stress during curing and reaction processes, preventing through-cracks in the coating and improving its thermal shock stability. The carbon material coating adhesive described in the second aspect utilizes polyether-modified phenolic resin to encapsulate nano-Si powder, enabling slow high-temperature pyrolysis and sustained Si source release. This meets the application requirements for coatings on crucibles used in the TSSG method for SiC single crystal growth, and, combined with the boron powder catalyst's effect of increasing the reaction rate, achieves a reaction-slow release adaptation.

[0029] The present invention also provides a method for preparing the carbon material coating adhesive described above, comprising the following steps: dispersing the functional reinforcing phase material, polyether-modified phenolic resin and composite additives in an alcohol solvent to obtain the carbon material coating adhesive.

[0030] Specifically, polyether-modified phenolic resin is dissolved in an alcohol solvent and stirred at 480 rpm to 520 rpm for 25 to 35 minutes to obtain a homogeneous and transparent solution. The obtained homogeneous and transparent solution, along with the functional reinforcing phase material and ether-based dispersing agent, is first subjected to low-frequency ultrasonication at 18 kHz to 22 kHz and 280 W to 320 W for 9 to 11 minutes, followed by high-frequency ultrasonication at 38 kHz to 42 kHz and 280 W to 320 W for 9 to 11 minutes to obtain a preliminary dispersion. Boron powder catalyst and silane coupling agent are added to the preliminary dispersion and stirred at 280 rpm to 320 rpm for 18 to 22 minutes. Then, an anti-cracking agent or polyether-modified phenolic resin-coated nano-Si powder is added and stirring continues to obtain a carbon material coating adhesive. In this invention, stepwise ultrasonication combined with a dispersing agent ensures that the Si powder agglomerate particle size is ≤5 μm; the flexible segments of the polyether-modified phenolic resin encapsulate the surface of the functional phase, further inhibiting agglomeration.

[0031] More specifically, after dispersing the functional reinforcing phase material, polyether-modified phenolic resin, and composite additives in an alcohol solvent, the present invention further includes viscosity adjustment of the resulting slurry. Specifically, the viscosity adjustment is performed to achieve a target value of 130 mPa. s~170 mPa Based on viscosity s, if the viscosity is too high, add 0.1%~0.3% of the alcohol solvent; if the viscosity is too low, add 0.05%~0.1% of the ether dispersant. Simultaneously, the viscosity adjustment must meet the requirement of a sedimentation rate ≤1%. This dual control of viscosity and sedimentation rate prevents slurry stratification during coating and ensures uniform coating composition. The sedimentation rate is tested using a static stability method: the viscosity-adjusted slurry is allowed to stand at room temperature for 29~31 minutes, and the sedimentation rate is measured using a sedimentation balance. A sedimentation rate ≤1% is considered acceptable; if unacceptable, the viscosity adjustment steps are repeated until the standard is met.

[0032] To avoid secondary pollution, this invention, after obtaining the carbon material coating adhesive, further includes passing the resulting carbon material coating adhesive through a 0.18 μm to 0.22 μm ceramic membrane filter at a filtration pressure of 0.25 MPa to 0.35 MPa, collecting the adhesive, and then vacuum-sealing it at 10℃ to 15℃. Vacuum sealing prevents the evaporation of alcohol solvents and the introduction of impurities, while cold storage delays resin pre-crosslinking, ensuring the long-term stability of the slurry. After filtration through the ceramic membrane, the final coating adhesive has a total metal ion content ≤1.5 ppm, meeting semiconductor-grade requirements.

[0033] In the preparation method provided by this invention, the functional reinforcing phase material, polyether-modified phenolic resin, composite additives, and alcohol solvent are all the same as described above and will not be repeated. In the preparation method provided by this invention, the total metal ion content of all raw materials is ≤1 ppm. Specifically, the alcohol solvent described in this invention undergoes purification treatment, specifically by passing the alcohol solvent through a molecular distillation apparatus, setting the temperature to 75℃~85℃ and the vacuum degree to ≤10. -3 Distilled at 1.5 h to 2.5 h, the fraction was collected, and the moisture content was determined to be ≤0.05% and the impurities ≤0.01%. Specifically, the micron-sized Si powder and nano-sized Si powder in the functional enhancement phase material of this invention undergo purification treatment. Specifically, the micron-sized Si powder and nano-sized Si powder are placed separately in an acid-resistant container, and a 4.5% to 5.5% hydrochloric acid solution is added. The mixture is stirred at room temperature for 1.5 h to 2.5 h; rinsed with deionized water until pH=6.8 to 7.2, dried, and then subjected to plasma cleaning at a power of 280 W to 320 W in an argon atmosphere for 4 min to 6 min to remove physically adsorbed organic matter from the surface. Specifically, the boron powder catalyst of this invention undergoes purification treatment. Specifically, the boron powder catalyst is subjected to plasma cleaning at 950℃ to 1050℃ and ≤10 -3Vacuum distillation at Pa for 0.5 h to 1.5 h removes metallic impurities, with metal ion concentrations ≤0.3 ppm. The preparation method provided by this invention employs multi-stage cleanliness control through a dual process of "raw material pre-purification + finished product filtration" to establish a solid foundation for ultra-cleanliness.

[0034] The present invention also provides a coated product comprising a substrate and a coating applied to the substrate, the coating being formed from any of the carbon material coating adhesives described above. In some embodiments of the present invention, the substrate is a carbon fiber composite substrate; the substrate is a crucible for SiC single crystal growth using the TSSG method, a thermal insulation cover, or a flow guide tube. Preferably, if the coated product is a crucible for SiC single crystal growth using the TSSG method, the coating is formed from the carbon material coating adhesive described in the second aspect above. If the coated product is not a crucible for SiC single crystal growth using the TSSG method, the coating is formed from the carbon material coating adhesive described in the first aspect above.

[0035] This invention also provides a method for applying a carbon material coating adhesive, comprising the following steps: S1) The substrate surface is plasma etched to a roughness of 1.5 μm to 2.5 μm under a protective gas atmosphere, and then impregnated with a silane coupling agent alcohol solution to obtain a pretreated substrate; S2) The substrate pretreated in step S1) is coated sequentially with any of the carbon material coating adhesives described above, followed by curing and gradient high-temperature reaction.

[0036] This invention first uses plasma etching to achieve a roughness (Ra) of 1.5 μm to 2.5 μm on the substrate surface, then impregnates it with a silane coupling agent alcohol solution to obtain a pretreated substrate; the substrate is the same as described above and will not be repeated. The substrate surface is plasma etched using a power of 280 W to 320 W for 4.5 min to 5.5 min. The silane coupling agent alcohol solution is used for impregnation; specifically, the etched substrate is immersed in the solution for 55 min to 65 min, then dried at 55°C to 65°C. This invention uses plasma etching to increase the specific surface area of ​​the substrate and uses KH-550 to form chemical bonds with the hydroxyl groups on the substrate surface, achieving "substrate-coating" interface strengthening and laying the foundation for improved coating adhesion. The silane coupling agent alcohol solution of the present invention includes an alcohol solution of one or more silane coupling agents selected from KH-550, KH-560, KH-570, and KH-792, preferably an alcohol solution of KH-550.

[0037] After obtaining the pretreated substrate, the present invention sequentially coats the pretreated substrate described in step S1) with any of the carbon material coating adhesives mentioned above, followed by curing and gradient high-temperature reaction. Specifically, the coating process of the present invention involves applying a coating at 190 g / m³. 2 ~310 g / m 2 Ultrasonic spraying is performed using a dosage of 200 g / m and a coating thickness of 145 μm to 205 μm. 2 ~300 g / m 2 Ultrasonic spraying with a dosage of 150 μm to 200 μm and a coating thickness of 240 g / m 2 ~360 g / m 2 Ultrasonic spraying is performed using a dosage of 250 g / m and a coating thickness of 195 μm to 255 μm. 2 ~350 g / m 2 The coating is ultrasonically sprayed at a dosage of 200 μm to 250 μm and then rolled at 0.3 MPa to 0.4 MPa; or, at 340 g / m 2 ~460 g / m 2 Spiral coating is performed using a dosage of 195 μm to 305 μm and a coating thickness of 195 μm, preferably at 350 g / m. 2 ~450 g / m 2 The material is applied in a spiral coating process with a dosage of 200 μm to 300 μm and a coating thickness of 200 μm, the spiral coating direction being upward along the substrate wall. The ultrasonic spraying pressure of the present invention is 0.25 MPa to 0.35 MPa. The substrate rotation speed for spiral coating of the present invention is 18 rpm to 22 rpm, and the coating speed of spiral coating is 4.5 cm / s to 5.5 cm / s. The rolling step of the present invention removes ≥95% of air bubbles, avoiding internal defects in the coating.

[0038] Specifically, the coating described in this invention uses different carbon material coating adhesives for customized coating based on different substrate scenarios. If the substrate in step S1) is a crucible for SiC single crystal growth using the TSSG method, then the carbon material coating adhesive is the carbon material coating adhesive described in the second aspect above, and the coating is performed at 340 g / m 2 ~460 g / m 2 Spiral coating is performed using a dosage of 195 μm to 305 μm and a coating thickness of 195 μm, preferably at 350 g / m. 2 ~450 g / m 2 The coating is applied in a spiral manner with an amount of [amount] and a coating thickness of 200 μm to 300 μm, and the spiral coating direction is spirally upward along the substrate wall.

[0039] If the substrate in step S1) is a device other than the crucible used for SiC single crystal growth using the TSSG method, then the carbon material coating adhesive is the carbon material coating adhesive described in the first aspect above, and the coating is performed at 190 g / m 2 ~310 g / m 2 Ultrasonic spraying is performed using a dosage of 200 g / m and a coating thickness of 145 μm to 205 μm. 2 ~300 g / m 2 Ultrasonic spraying with a dosage of 150 μm to 200 μm and a coating thickness of 240 g / m 2 ~360 g / m 2 Ultrasonic spraying is performed using a dosage of 250 g / m and a coating thickness of 195 μm to 255 μm. 2 ~350 g / m 2 The coating is ultrasonically sprayed at a dosage of 200 μm to 250 μm and then rolled at 0.3 MPa to 0.4 MPa. Preferably, if the substrate in step S1) is a flow guide tube, the carbon material coating adhesive is the carbon material coating adhesive described in the first aspect above, and the coating is performed at 240 g / m 2 ~360 g / m 2 Ultrasonic spraying is performed using a dosage of 250 g / m and a coating thickness of 195 μm to 255 μm. 2 ~350 g / m 2 The coating is ultrasonically sprayed with a dosage of 200 μm to 250 μm and then rolled at 0.3 MPa to 0.4 MPa. More specifically, the rolling is performed using an impurity-free ceramic roller with a hardness of HRC60 and a surface Ra≤0.1 μm at 0.3 MPa to 0.4 MPa and 25 rpm to 35 rpm.

[0040] The curing function described in this invention is to fix the coating structure and release some stress. Specifically, the substrate coated with carbon material adhesive is cured and then cooled to room temperature; the curing temperature is 115℃~155℃; the curing time is 115 min~125 min; and the cooling rate is ≤3℃ / min. Slow heating and cooling reduce curing shrinkage stress, and the flexible segments of the polyether-modified phenolic resin further buffer stress, preventing early cracking of the coating.

[0041] More specifically, the curing temperature of the present invention is set according to different substrate scenarios. If the substrate in step S1) is a crucible for SiC single crystal growth using the TSSG method, the curing temperature is 115℃~125℃; if the substrate in step S1) is a device other than a crucible for SiC single crystal growth using the TSSG method and is not a flow guide tube, the curing temperature is 125℃~135℃; if the substrate in step S1) is a flow guide tube, the curing temperature is 145℃~155℃.

[0042] The function of the gradient high-temperature reaction described in this invention is to promote SiC formation through the combined action of the boron powder catalyst in the formulation and the gradient high-temperature reaction in the preparation method, thereby improving the density of the coating and achieving a SiC conversion rate ≥95%. Specifically, the gradient high-temperature reaction of this invention involves: carbonization at 600℃~800℃ for 3.5 h~6.5 h, preferably 4 h~6 h, under a protective gas atmosphere; reduction at 1500℃~1700℃ for 7.5 h~12.5 h, preferably 8 h~12 h, under a vacuum degree ≤100 Pa; followed by cooling to 900℃~1000℃ at a rate of 4℃ / min~6℃ / min, and then cooling to room temperature at a rate of 2℃ / min~4℃ / min. The carbonization described in this invention removes volatile components from the resin; the reduction allows the Si powder and resin residue to fully react under the catalysis of boron powder to generate SiC; and the gradient heating and cooling reduces thermal stress and improves the bonding stability between the coating and the substrate.

[0043] More specifically, carbonization is carried out for 4 to 6 hours at a heating rate of 4.5 to 5.5 °C / min to 600 °C under a protective gas atmosphere, followed by reduction for 8 to 12 hours at a heating rate of 7.5 to 8.5 °C / min to 1500 °C to 1700 °C under a vacuum ≤100 Pa. Then, the temperature is first cooled to 900 to 1000 °C at a rate of 4 to 6 °C / min, and then cooled to room temperature at a rate of 2 to 4 °C / min to avoid thermal shock cracking. The flow rate of the protective gas atmosphere is 450 mL / min to 550 mL / min, and the vacuum degree is ≤100 Pa. The purity of the protective gas atmosphere is ≥99.99%.

[0044] More specifically, the curing process of this invention sets the carbonization and reduction temperatures in the gradient high-temperature reaction according to different substrate scenarios. Specifically, if the substrate in step S1) is a crucible for SiC single crystal growth using the TSSG method, the carbonization temperature is 750℃~800℃, and the reduction temperature is 1650℃~1700℃; if the substrate in step S1) is a device other than a crucible for SiC single crystal growth using the TSSG method, and is not a flow guide tube, the carbonization temperature is 600℃~650℃, and the reduction temperature is 1500℃~1550℃; if the substrate in step S1) is a flow guide tube, the carbonization temperature is 675℃~725℃, and the reduction temperature is 1575℃~1625℃.

[0045] The present invention also provides a production system for products with coatings, comprising, in sequence: a substrate interface strengthening module, a scene-customized coating module, a gradient high-temperature reaction module, and a finished product cleanliness detection module; and further comprising a composite system preparation module connected in front of the scene-customized coating module, and a raw material multi-stage purification module connected in front of the composite system preparation module.

[0046] The substrate interface strengthening module of this invention is used in step S1) of the aforementioned carbon material coating adhesive application method to obtain a pretreated substrate. The substrate is obtained through "plasma etching + KH-550 grafting", and the core technology is "physical bonding + chemical bonding". This improves the surface roughness of the substrate to Ra=1.5 μm~2.5 μm and the interfacial bonding force from ≤1.2 MPa to ≥4.5 MPa, thus solving the problems of "weak bonding force and easy peeling".

[0047] The scene-customized coating module of the present invention is used to coat and cure the pretreated substrate obtained from the substrate interface strengthening module in the aforementioned carbon material coating adhesive application method (step S2). For different component working conditions, it adopts differentiated processes of "spraying / spiral coating / spraying-rolling". The core technology is "process-scene adaptation" to ensure that the coating thickness and density match the protection requirements.

[0048] The gradient high-temperature reaction module of this invention is used to perform a gradient high-temperature reaction step (S2) in the aforementioned carbon material coating adhesive application method on the coated substrate obtained from the scene-customized coating module, ultimately obtaining a coated product. The core technology is "reaction rate-stress release synergy", which is based on "carbonization devolatilization → boron powder catalytic reduction → gradient cooling". This ensures that the SiC conversion rate is ≥95% and the coating porosity is ≤0.3%, while avoiding thermal shock cracking.

[0049] The finished product cleanliness testing module of this invention is used to perform cleanliness testing on coated products obtained from the gradient high-temperature reaction module. It uses "ICP-MS cleanliness testing + SEM microscopic testing + antioxidant / slow-release performance testing" and the core technology is "quantitative control of all indicators" to ensure that the finished product meets the protection and cleanliness requirements of high-end scenarios.

[0050] The composite system preparation module of this invention is used to prepare the carbon material coating adhesive of this invention, and then transport it to the scene-customized coating module. It integrates "polyether modified phenolic resin dissolution → functional phase stepwise ultrasonic dispersion → additive compounding → viscosity-sedimentation rate dual regulation → ceramic membrane filtration". The core technology is "enhancement-dispersion synergy". Through the synergistic effect of polyether segments, ether dispersing agents and Si powder gradation, the slurry sedimentation rate is ≤1%, which provides a guarantee for "high dispersion and crack resistance".

[0051] The multi-stage purification module for raw materials described in this invention is used to purify the carbon material coating adhesive prepared in this invention, and then transport it to the composite system preparation module. It includes Si powder "acid washing + plasma cleaning", ethanol molecular distillation, resin grafting modification, and boron powder vacuum distillation. The core technology is "multi-dimensional impurity stripping", which achieves a total metal ion content of ≤1 ppm in the raw materials, laying the foundation for "ultra-cleanliness" and avoiding impurity contamination of semiconductor single crystals.

[0052] This invention provides a carbon material coating adhesive, its preparation method, and its application. The carbon material coating adhesive provided by this invention achieves full-chain synergy from raw materials to preparation, coating, reaction, and detection. Multi-stage purification ensures cleanliness from the source; polyether modification, functional phase gradation, and stepwise ultrasonication solve dispersion and cracking problems; interface grafting and plasma etching enhance adhesion; boron powder catalysis and gradient high temperature improve conversion rate; and scene-customized coating adapts to different working conditions. The technical parameters of each step (such as raw material impurity quantification standards, ultrasonic power, reaction temperature, and equipment vacuum degree) are all functionally adapted designs, forming a complete logical chain of "ultra-cleanliness → high dispersion → strong adhesion → crack resistance → high conversion → scene adaptation," ultimately achieving performance indicators of "metal ions ≤ 1.5 ppm, coating adhesion ≥ 4.5 MPa, SiC conversion rate ≥ 95%, and weight loss rate at 550℃ / 8h ≤ 0.15%," fully meeting the long-term protection requirements of high-end scenarios such as single-crystal silicon thermal fields and TSSG method SiC single-crystal growth. Detailed Implementation

[0053] This invention discloses a carbon material coating adhesive, its preparation method, and its application. Those skilled in the art can refer to this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments; those skilled in the art will clearly be able to modify or appropriately alter and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0054] The apparatus used in this invention is shown in Table 1: Table 1

[0055]

[0056] The formulation and specifications of the silicon carbide coating system based on the phenolic resin-Si powder-alcohol system of the present invention are shown in Table 2: Table 2

[0057]

[0058] Note: Among the composite additives in Table 2, the microcapsule sustained-release agent is only used for crucible coatings for SiC single crystal growth using the TSSG method to meet the stable supply requirements of Si source. For coatings in other scenarios, anti-cracking additives are used.

[0059] The Si powder microcapsules are core-shell structured microcapsules with polyether-modified phenolic resin as the wall material and nano-Si powder as the core material. Key indicators include: microcapsule particle size of 5-10 μm, core material content of 70%-80%, uniform wall material thickness (0.5-1 μm), no obvious damage, and good dispersibility in alcohol systems (no sedimentation after standing in the coating adhesive for 30 min). The core material is nano-Si powder (50-100 nm, purity ≥99.99%, metal ion ≤0.5 ppm), providing the Si source; the wall material is polyether-modified phenolic resin (phenolic resin grafted with PEG-6000 at a 9:1 ratio, with a phenolic resin residual carbon rate of 50%), serving as a "slow-release barrier + carbon source supplement."

[0060] The preparation method of the Si powder microcapsules is as follows: The in-situ polymerization method is adopted (which meets the core requirements of resin-coated powders, introduces no impurities, and is simple to operate). The specific steps, parameters, and objectives are as follows, and the entire process follows the principle of "no impurities control + uniform coating": I. Raw material preparation; Prepare the raw materials according to the Si powder microcapsule formula shown in Table 3: Table 3

[0061]

[0062] II. Preparation steps; 1. Core material pretreatment: Improves dispersibility and interfacial bonding; Procedure: Add 70-80 g of nano-Si powder to 100 mL of anhydrous ethanol, add 0.3-0.5 g of TX-100, turn on ultrasonic dispersion (40 kHz, 300 W) for 15 min, and then stir with a high-speed stirrer (1500 rpm) for 20 min to form a uniform nano-Si powder dispersion. Objective: To adsorb TX-100 onto the surface of Si powder, inhibiting agglomeration and improving the interfacial compatibility between Si powder and wall material (polyether modified phenolic resin); Key control: The particle size of Si powder agglomerates after dispersion is ≤5 μm (detected by laser particle size analyzer).

[0063] 2. Wall material preparation: adapting to coating requirements; Procedure: Add 22.75 g of polyether-modified phenolic resin to 200-400 mL of anhydrous ethanol, stir at 500 rpm for 30 min until completely dissolved, add 2.25 g of hexamethylenetetramine (curing agent), and continue stirring for 10 min to form a homogeneous wall material solution. Objective: To pre-react the curing agent with polyether-modified phenolic resin to provide active sites for subsequent in-situ polymerization; Key control: Wall material solution viscosity 100±20 mPa s (25℃, test at 4 cups), no undissolved particles.

[0064] 3. In-situ polymerization and coating: forming a core-shell structure; Procedure: Slowly pour the core material dispersion into the wall material solution (dropping rate 5 mL / min) while maintaining high-speed stirring (1200 rpm), heat to 60℃, and stir at a constant temperature for 3 h; then heat to 90℃ and continue stirring for 2 h to allow the wall material to fully cure and crosslink. Reaction logic: Hexamethylenetetramine decomposes to produce formaldehyde, which undergoes a polycondensation reaction with the hydroxymethyl group of polyether-modified phenolic resin, forming a dense resin wall material in situ on the surface of nano-Si powder. Key controls: Stable stirring speed (error ±50 rpm), temperature fluctuation within ±3℃, to avoid wall material agglomeration or uneven coating.

[0065] 4. Post-processing: purification + shaping (meeting cleanliness requirements); Filtration: After the reaction is complete, the solid particles (crude microcapsule product) are collected by vacuum filtration using a 0.2 μm ceramic membrane filter. Washing: Wash three times with anhydrous ethanol (100 mL each time) to remove unreacted resin, curing agent and dispersant from the surface; Drying: Place the washed microcapsules in a vacuum drying oven and dry them at 60℃ and a vacuum degree ≤100 Pa for 4 h to remove the ethanol solvent; Sieving: Use a 5~10 μm standard sieve to sieve and remove particles that are too large (>10 μm) or too small (<5 μm) to obtain the finished Si powder microcapsules; Key controls: After drying, the moisture content of the microcapsules is ≤0.5%, and the total metal ion content is ≤1 ppm (ICP-MS detection).

[0066] III. Quality Verification Standards (to ensure compatibility with application scenarios); Morphology: SEM observation showed that the microcapsules were spherical, with continuous and undamaged wall material and no exposed Si powder; Particle size: Detected by laser particle size analyzer, D50=5~10 μm, uniform particle size distribution (coefficient of variation ≤15%). Core material percentage: Tested by burning method (800℃, air atmosphere, 2 h), core material residue is 70%~80% (the wall material is completely burned and decomposed). Dispersibility: When microcapsules are added to the patented coating adhesive (alcohol system) at a mass ratio of 2% to 5%, and allowed to stand for 30 minutes, the sedimentation rate is ≤1%; Slow-release performance: Under simulated TSSG conditions (1700℃, vacuum environment), the Si source release rate fluctuation is ≤5% (Si volatilization is detected by gas chromatography).

[0067] The present invention will be further described below with reference to the embodiments: Example 1 First, the coating slurry was prepared according to the silicon carbide coating formulation of the phenolic resin-Si powder-alcohol system shown in Table 1. The precise formulation is shown in Table 4. Table 4

[0068]

[0069] Step 1: Multi-stage purification of raw materials (Function: to build a solid foundation for ultra-cleanliness); 1. Operation content: Si powder purification: Micron-sized Si powder and nano-sized Si powder were placed in acid-resistant containers, and 5% hydrochloric acid solution (liquid-solid ratio 3:1) was added. The mixture was stirred at room temperature for 2 h. The mixture was rinsed with deionized water until pH=7 and dried at 120℃ for 2 h. The mixture was then transferred to a plasma cleaner (argon atmosphere, power 300 W, time 5 min) to remove physically adsorbed organic matter from the surface.

[0070] Ethanol purification: Anhydrous ethanol is passed into a molecular distillation apparatus, with the temperature set at 80℃ and the vacuum degree at 10. -3 Pa, distill for 2 h, collect the fraction, and test for moisture ≤0.05% and impurities ≤0.01%.

[0071] Preparation of polyether-modified phenolic resin: Phenolic resin and PEG-6000 were mixed at a mass ratio of 9:1 and added to a reaction vessel. The mixture was stirred at a constant temperature of 120℃ for 2 h. After the grafting reaction was completed, the mixture was cooled to room temperature, sealed, and stored for later use. The residual carbon rate was measured to be 45%~55%.

[0072] Boron powder purification: Boron powder is placed in a vacuum distillation furnace at 1000℃ for 10 minutes. -3 Distilled at Pa for 1 h to remove metal impurities, with metal ions detected at ≤0.3 ppm.

[0073] 2. Technical assurance: All raw materials are tested by ICP-MS, and the total metal ion content is ≤1 ppm; the purification equipment is degreased and dried with ethanol to avoid cross-contamination.

[0074] Step 2: Preparation of the composite system (Function: Achieving high dispersion and enhancing synergy); 1. Operation content: Basic slurry preparation: Add the polyether-modified phenolic resin to the purified anhydrous ethanol according to the ratio, turn on the magnetic stirrer (500 rpm), stir for 30 min until the resin is completely dissolved and a uniform and transparent resin solution is formed.

[0075] Functional phase dispersion: Mix purified micron-sized Si powder, nano-sized Si powder and SiC whiskers in a mass ratio of 7:2:1, add TX-100 dispersant, and pour into resin solution; first turn on low-frequency ultrasound (20 kHz, 300W) to disperse for 10 min, then switch to high-frequency ultrasound (40 kHz, 300W) to disperse for 10 min to break up agglomerates and form a preliminary dispersion.

[0076] Additive compounding: Add impurity-free boron powder and KH-550 coupling agent to the preliminary dispersion, stir at 300 rpm for 20 min to ensure uniform dispersion of the additives.

[0077] Step 3: Slurry stability control (Function: Ensure coating uniformity); 1. Operation content: Online viscosity monitoring: The viscosity of the composite slurry was measured using a Forte 4 cup viscometer (25℃). The viscosity measurement temperature was 25℃±1℃, and the target value was 150±20 mPa. If the viscosity is too high, add 0.1%~0.3% purified ethanol; if the viscosity is too low, add 0.05%~0.1% TX-100, stir for 5 minutes and then test again.

[0078] Static stability test: Pour the slurry with adjusted viscosity into a clean container and let it stand at room temperature for 30 minutes. Use a sedimentation balance to test the sedimentation rate. ≤1% is acceptable. If it is unacceptable, repeat the viscosity adjustment steps until it meets the standard.

[0079] Step 4: Clean filtration and storage of finished product (Function: to avoid secondary contamination); 1. Operation procedure: Pass the qualified slurry through a 0.2 μm ceramic membrane filter at a filtration pressure of 0.3 MPa, collect the filtered slurry to obtain a general-purpose coating adhesive; transfer it into a vacuum-sealed glass jar, label the formula type (general-purpose / crucible-specific) and preparation date, and store it in a refrigerator at 10℃~15℃ for a shelf life of 6 months.

[0080] Example 2

[0081] Compared with Example 1, the difference is that the crack-resistant agent in the composite additive is replaced with Si powder microcapsules, and the precise dosage of each component is changed. The precise formulation is shown in Table 5: Table 5

[0082]

[0083] The final product is a crucible-specific coating adhesive.

[0084] Comparative Example 1

[0085] Compared with Example 2, the only difference is that the binder-carbon source is replaced with unmodified phenolic resin (molecular weight 900 Da, residual carbon rate 48%, ethanol solubility 94.3%, no polyether grafting, metal ions ≤1 ppm).

[0086] Application Example 1

[0087] For thermal insulation cover application scenarios: Step 1: Matrix pretreatment (Function: Interface strengthening, improving adhesion); 1. Operation content: Machining and cleaning: The carbon fiber composite material is machined to the target size (graphite insulation cover substrate size 500 mm × 300 mm × 50 mm), the surface dust is swept away with a brush, and then the surface is wiped with anhydrous ethanol (purity ≥ 99.9%) to degrease.

[0088] Plasma etching: The substrate is placed in a plasma cleaner under an argon atmosphere with a power of 300W for 5 minutes to form a micro-nano uneven structure on the surface. The surface roughness of the substrate after plasma etching is Ra=1.5~2.5 μm.

[0089] Interface grafting: Prepare a 5% KH-550 alcohol solution, immerse the etched substrate for 1 hour, remove it and place it in an oven to dry at 60°C for 2 hours, so that KH-550 forms a chemical bond with the hydroxyl groups on the substrate surface.

[0090] Step 2: Scene-specific coating (Function: Adapt to the working conditions of different components). 1. Operation content: The general-purpose coating adhesive prepared in Example 1 was used, and ultrasonic spraying equipment (spray gun nozzle diameter 0.8 mm, pressure 0.3 MPa, droplet size 10 μm) was employed at a concentration of 250 g / m³. 2 The coating is applied evenly to the graphite insulation cover substrate, with a coating thickness of 180 μm, and there are no missed areas or drips.

[0091] Step 3: Preliminary curing (Function: to fix the coating structure and release some stress); 1. Operation procedure: Place the coated substrate in an oven, set the temperature to 120℃, maintain the temperature for 2 hours, and allow it to cool naturally to room temperature after curing at a rate of 2℃ / min.

[0092] Step 4: Gradient high-temperature reaction (Function: Promotes SiC formation and improves coating density). 1. Operation content: Carbonization treatment: Place the cured matrix into a carbonization furnace, introduce nitrogen gas (purity ≥99.99%) at a flow rate of 500 mL / min, raise the temperature at a rate of 5℃ / min to 600℃, and carbonize at a constant temperature for 6 h to remove volatile components from the resin.

[0093] Reduction reaction: The carbonized matrix is ​​transferred into a vacuum furnace, evacuated to 100 Pa, heated at a rate of 8 °C / min to 1500 °C, and held at a constant temperature for 12 h to allow Si powder and resin residue carbon to fully react under the catalysis of boron powder to generate SiC.

[0094] Gradient cooling: After the reaction is complete, first cool to 1000℃ at a rate of 5℃ / min, then cool to room temperature at a rate of 3℃ / min to avoid thermal shock cracking.

[0095] Step 5: Finished product cleanliness inspection (Function: Ensures that semiconductor-grade requirements are met); 1. Operation content: Cleanliness testing: The metal ion content of the coating was detected by ICP-MS, and the total content was ≤1.5 ppm to be considered qualified. The detection limit of ICP-MS was ≤0.1 ppm, and the cross-section spacing was 1 mm.

[0096] Microscopic performance testing: The cross-section of the coating was observed by SEM, and the porosity was ≤0.3%; the adhesion was tested by cross-cut test (1 mm grid, 3M tape peeling), and ≥4.5 MPa was considered qualified.

[0097] Protective performance test: Place the finished product in a high-temperature anti-oxidation furnace and keep it in an air atmosphere at 550℃ for 8 hours (anti-oxidation test temperature can be 550℃±5℃). The weight loss rate ≤0.15% is qualified.

[0098] Long-term service stability: When placed in a monocrystalline silicon thermal field system, subjected to high-speed airflow of 0.5 MPa, and withstood a high temperature of 1600℃, it can be continuously used for 120 furnace cycles, with each furnace cycle lasting 10 hours.

[0099] 2. Technical support: All testing equipment is calibrated to prevent secondary contamination during the testing process. Unqualified products are returned for recoating or discarded.

[0100] 3. Results: As shown in Table 6: Table 6

[0101]

[0102] Application Example 2

[0103] Application scenarios for SiC single crystal growth crucibles using the TSSG method: Step 1: Matrix pretreatment (Function: Interface strengthening, improving adhesion); 1. Operation content: Machining and cleaning: The carbon fiber composite material is machined to the target size (outer diameter of graphite crucible 200 mm, inner diameter 180 mm, height 150 mm), the surface dust is swept away with a brush, and then the surface is wiped with anhydrous ethanol (purity ≥99.9%) to degrease.

[0104] Plasma etching: The substrate is placed in a plasma cleaner under an argon atmosphere with a power of 300W for 5 minutes to form a micro-nano uneven structure on the surface. The surface roughness of the substrate after plasma etching is Ra=1.5~2.5 μm.

[0105] Interface grafting: Prepare a 5% KH-550 alcohol solution, immerse the etched substrate for 1 hour, remove it and place it in an oven to dry at 60°C for 2 hours, so that KH-550 forms a chemical bond with the hydroxyl groups on the substrate surface.

[0106] Step 2: Scene-specific coating (Function: Adapt to the working conditions of different components). 1. Operation content: The crucible-specific coating adhesive prepared in Example 2 was used, and a spiral coating device was employed (substrate rotation speed 20 rpm, coating speed 5 cm / s) at a rate of 400 g / m. 2 The coating is applied to the inner wall of a graphite crucible, with a thickness of 280 μm, and the coating direction is spiraling upwards along the inner wall of the crucible.

[0107] Step 3: Preliminary curing (Function: to fix the coating structure and release some stress); 1. Operation procedure: Place the coated substrate in an oven, set the temperature to 150℃, and cure at a constant temperature for 2 hours. After curing, allow it to cool naturally to room temperature at a cooling rate of 2℃ / min.

[0108] Step 4: Gradient high-temperature reaction (Function: Promotes SiC formation and improves coating density). 1. Operation content: Carbonization treatment: Place the cured matrix into a carbonization furnace, introduce nitrogen gas (purity ≥99.99%) at a flow rate of 500 mL / min, raise the temperature at a rate of 5℃ / min to 750℃, and carbonize at a constant temperature for 5 h to remove volatile components from the resin.

[0109] Reduction reaction: The carbonized matrix is ​​transferred into a vacuum furnace, evacuated to 80 Pa, heated at a rate of 8℃ / min to 1700℃, and held at a constant temperature for 10 h to allow Si powder and resin residue carbon to fully react under the catalysis of boron powder to generate SiC.

[0110] Gradient cooling: After the reaction is complete, first cool to 1000℃ at a rate of 5℃ / min, then cool to room temperature at a rate of 3℃ / min to avoid thermal shock cracking.

[0111] Step 5: Finished product cleanliness inspection (Function: Ensures that semiconductor-grade requirements are met); 1. Operation content: Cleanliness testing: The metal ion content of the coating was detected by ICP-MS, and the total content was ≤1.5 ppm to be considered qualified. The detection limit of ICP-MS was ≤0.1 ppm, and the cross-section spacing was 1 mm.

[0112] Microscopic performance testing: The cross-section of the coating was observed by SEM, and the porosity was ≤0.3%; the adhesion was tested by cross-cut test (1 mm grid, 3M tape peeling), and ≥4.5 MPa was considered qualified.

[0113] Protection performance testing: In the TSSG method SiC single crystal growth simulation, a Si source release rate fluctuation of ≤5% is considered acceptable. The core requirements for using the TSSG method SiC single crystal growth crucible are to ensure stable Si source volatilization / release, without contaminating the single crystal or disrupting the growth atmosphere, rather than ordinary high-temperature oxidation weight loss resistance; therefore, using the Si source release rate fluctuation instead of the weight loss rate as the core qualification indicator is more in line with the actual working conditions of this scenario.

[0114] Long-term service stability: When placed in a monocrystalline silicon thermal field system, subjected to high-speed airflow of 0.5 MPa, and withstood a high temperature of 1600℃, it can be continuously used for 120 furnace cycles, with each furnace cycle lasting 10 hours.

[0115] 2. Technical support: All testing equipment is calibrated to prevent secondary contamination during the testing process. Unqualified products are returned for recoating or discarded.

[0116] SiC single crystal growth using the TSSG method: Si-40at%Cr alloy solution (2150℃), seed crystal rotation speed 150 rpm, crucible rotation speed 20 rpm, pulling speed 1000 μm / h, pulling time 20 h.

[0117] 3. Results: As shown in Table 7: Table 7

[0118]

[0119] Application Example 3

[0120] For applications of the deflector: Step 1: Matrix pretreatment (Function: Interface strengthening, improving adhesion); 1. Operation content: Machining and cleaning: The carbon fiber composite material is machined to the target size (inner diameter of carbon fiber composite guide tube 100 mm, outer diameter 120 mm, height 300 mm), the surface dust is swept away with a brush, and then the surface is wiped with anhydrous ethanol (purity ≥99.9%) to degrease.

[0121] Plasma etching: The substrate is placed in a plasma cleaner under an argon atmosphere with a power of 300W for 5 minutes to form a micro-nano uneven structure on the surface. The surface roughness of the substrate after plasma etching is Ra=1.5~2.5 μm.

[0122] Interface grafting: Prepare a 5% KH-550 alcohol solution, immerse the etched substrate for 1 hour, remove it and place it in an oven to dry at 60°C for 2 hours, so that KH-550 forms a chemical bond with the hydroxyl groups on the substrate surface.

[0123] Step 2: Scene-specific coating (Function: Adapt to the working conditions of different components). 1. Operation content: The general-purpose coating adhesive prepared in Example 1 was used, and ultrasonic spraying equipment (spray gun nozzle diameter 0.8 mm, pressure 0.35 MPa, droplet size 10 μm) was employed at a concentration of 300 g / m³. 2 Apply the coating evenly with a thickness of 225 μm, ensuring no missed areas or runs. Immediately after spraying, roll the coating with a clean ceramic roller (hardness HRC60, surface Ra≤0.1 μm) (pressure 0.35 MPa, speed 30 rpm) to remove air bubbles, achieving a bubble removal rate ≥95%.

[0124] Step 3: Preliminary curing (Function: to fix the coating structure and release some stress); 1. Operation procedure: Place the coated substrate in an oven and set the temperature to 130℃ for constant curing for 2 hours. After curing, allow it to cool naturally to room temperature at a rate of 2℃ / min.

[0125] Step 4: Gradient high-temperature reaction (Function: Promotes SiC formation and improves coating density). 1. Operation content: Carbonization treatment: The cured matrix is ​​placed in a carbonization furnace, nitrogen gas (purity ≥99.99%) is introduced at a flow rate of 500 mL / min, the temperature is increased at a rate of 5℃ / min to 700℃, and the temperature is kept constant for 5.5 h to remove volatile components from the resin.

[0126] Reduction reaction: The carbonized matrix is ​​transferred into a vacuum furnace, evacuated to 90 Pa, heated at a rate of 8℃ / min to 1600℃, and held at a constant temperature for 11 h to allow Si powder and resin residue carbon to fully react under the catalysis of boron powder to generate SiC.

[0127] Gradient cooling: After the reaction is complete, first cool to 1000℃ at a rate of 5℃ / min, then cool to room temperature at a rate of 3℃ / min to avoid thermal shock cracking.

[0128] Step 5: Finished product cleanliness inspection (Function: Ensures that semiconductor-grade requirements are met); 1. Operation content: Cleanliness testing: The metal ion content of the coating was detected by ICP-MS, and the total content was ≤1.5 ppm to be considered qualified. The detection limit of ICP-MS was ≤0.1 ppm, and the cross-section spacing was 1 mm.

[0129] Microscopic performance testing: The cross-section of the coating was observed by SEM, and the porosity was ≤0.3%; the adhesion was tested by cross-cut test (1 mm grid, 3M tape peeling), and ≥4.5 MPa was considered qualified.

[0130] Protective performance test: Place the finished product in a high-temperature anti-oxidation furnace and keep it in an air atmosphere at 550℃ for 8 hours (anti-oxidation test temperature can be 550℃±5℃). The weight loss rate ≤0.15% is qualified.

[0131] Long-term service stability: When put into a monocrystalline silicon thermal field system, it can withstand a high temperature of 1500℃ and a high-speed airflow of 0.5 MPa for 100 consecutive furnace cycles, each furnace cycle lasting 10 hours.

[0132] 2. Technical support: All testing equipment is calibrated to prevent secondary contamination during the testing process. Unqualified products are returned for recoating or discarded.

[0133] 3. Results: As shown in Table 8: Table 8

[0134]

[0135] Application Comparative Example 1

[0136] Compared to Application Example 2, the only difference is that the coating adhesive was replaced with the coating adhesive of Comparative Example 1; everything else remained the same. The results are shown in Table 9: Table 9

[0137]

[0138] In addition, to highlight the performance differences between modified and unmodified resins, comparative data is provided in Table 10: Table 10

[0139]

[0140] The above description is only 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 carbon material coating adhesive, characterized in that, In terms of mass percentage, it includes: Alcohol solvent: 18%~25%; Functional reinforcing phase material: 42%~52%, wherein the functional reinforcing phase material comprises micron-sized Si powder, nano-sized Si powder and SiC whiskers in a mass ratio of (7~8):(2~3):1; Polyether-modified phenolic resin: 20%~28%; Composite additives: 3%~7%, wherein the composite additives include 0.2%~0.4% boron powder catalyst, 0.5%~1% ether dispersant, 2%~5% anti-cracking agent and 0.3%~0.6% silane coupling agent, wherein the ether dispersant is selected from one or more of polyethylene glycol alkyl aryl ethers and alkyl polyoxyolefin ethers.

2. The carbon material coating adhesive according to claim 1, characterized in that, The anti-cracking agent is selected from one or more of amorphous boron powder, boric acid, boron carbide, nano-silica, and nano-alumina.

3. A carbon material coating adhesive, characterized in that, In terms of mass percentage, it includes: Alcohol solvent: 18%~25%; Functional reinforcing phase material: 42%~52%, wherein the functional reinforcing phase material comprises micron-sized Si powder, nano-sized Si powder and SiC whiskers in a mass ratio of (7~8):(2~3):1; Polyether-modified phenolic resin: 20%~28%; Composite additives: 3%~7%, wherein the composite additives include 0.2%~0.4% boron powder catalyst, 0.5%~1% ether dispersant, 2%~5% polyether modified phenolic resin coated nano-Si powder and 0.3%~0.6% silane coupling agent, wherein the ether dispersant is selected from one or more of polyethylene glycol alkyl aryl ethers and alkyl polyoxyolefin ethers.

4. The carbon material coating adhesive according to claim 3, characterized in that, The polyether-modified phenolic resin-coated nano-Si powder includes a nano-Si powder core and a polyether-modified phenolic resin wall layer coating the surface of the nano-Si powder core. The mass percentage of the nano-Si powder core is 70%~80%; The particle size of the polyether-modified phenolic resin-coated nano-Si powder is 5 μm to 10 μm.

5. The carbon material coating adhesive according to claim 4, characterized in that, The polyether-modified phenolic resin wall layer is obtained by curing polyether-modified phenolic resin grafted with phenolic resin with a molecular weight of 800 Da to 1200 Da and polyethylene glycol with a molecular weight of 5000 Da to 7000 Da at a mass ratio of (8 to 10): 1; the residual carbon rate of the phenolic resin is 45% to 55%.

6. The carbon material coating adhesive according to any one of claims 1 to 5, characterized in that, The alcohol solvent is selected from one or more of ethanol, isopropanol, n-propanol, propylene glycol, and isobutanol; The polyether-modified phenolic resin is obtained by grafting phenolic resin with a molecular weight of 800 Da to 1200 Da and polyethylene glycol with a molecular weight of 5000 Da to 7000 Da at a mass ratio of (8 to 10): 1; the residual carbon content of the phenolic resin is 45% to 55%. The particle size of the micron-sized Si powder is 5 μm to 20 μm; the particle size of the nano-sized Si powder is 50 nm to 100 nm; the diameter of the SiC whiskers is 0.5 μm to 2 μm and the length is 10 μm to 30 μm. The ether dispersant is selected from one or more of polyethylene glycol octylphenyl ether, octylphenol polyoxyethylene ether, and nonylphenol polyoxyethylene ether. The silane coupling agent is selected from one or more of KH-550, KH-560, KH-570, and KH-792.

7. The method for preparing the carbon material coating adhesive according to any one of claims 1 to 6, characterized in that, Includes the following steps: The functional enhancement phase material, polyether-modified phenolic resin, and composite additives are dispersed in an alcohol solvent to obtain a carbon material coating adhesive.

8. A product with a coating, characterized in that, It includes a substrate and a coating applied to the substrate, the coating being formed from a carbon material coating adhesive as described in any one of claims 1 to 6.

9. A method for applying a coating adhesive to carbon materials, characterized in that, Includes the following steps: S1) The substrate surface is plasma etched to a roughness of 1.5 μm to 2.5 μm under a protective gas atmosphere, and then impregnated with a silane coupling agent alcohol solution to obtain a pretreated substrate; S2) The carbon material coating adhesive described in any one of claims 1 to 6 is used to sequentially coat the pretreated substrate in step S1), followed by curing and gradient high-temperature reaction.

10. The application method according to claim 9, characterized in that, In step S2), the gradient high-temperature reaction specifically involves: carbonization at 600℃~800℃ for 3.5 h~6.5 h under a protective gas atmosphere, followed by reduction at 1500℃~1700℃ for 7.5 h~12.5 h under a vacuum of ≤100 Pa, then cooling to 900℃~1000℃ at a rate of 4℃ / min~6℃ / min, and then cooling to room temperature at a rate of 2℃ / min~4℃ / min. In step S2), the coating specifically involves applying a coating at 190 g / m³. 2 ~310 g / m 2 Ultrasonic spraying was performed using a dosage of [specific ingredient] and a coating thickness of 145 μm to 205 μm. Alternatively, at 240 g / m 2 ~360 g / m 2 The coating is ultrasonically sprayed with a dosage of 195 μm to 255 μm and then rolled at 0.3 MPa to 0.4 MPa. Alternatively, at 340 g / m 2 ~460 g / m 2 The coating is applied in a spiral manner with an amount of [amount] and a coating thickness of 195 μm to 305 μm, wherein the spiral coating direction is spirally upward along the substrate wall.

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