Low-temperature self-drying high-temperature-resistant organic silicon coating and preparation method thereof

Abstract

The invention relates to the technical field of new materials and application thereof, in particular to a low-temperature self-drying high-temperature-resistant organic silicon coating and a preparation method thereof. The invention relates to a low-temperature self-drying high-temperature-resistant organic silicon coating. The low-temperature self-drying high-temperature-resistant organic silicon coating consists of a component A and a component B, the component A is prepared from 45 to 55 parts of resin, 25 to 35 parts of modified filler, 25 to 30 parts of solvent, 0.5 to 1 part of anti-settling agent, 0.2 to 0.5 part of flatting agent, 0.3 to 0.8 part of defoaming agent and 1 to 1.5 parts of catalyst 1; the component B comprises a curing agent and a catalyst 2; the resin comprises hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin and amino modified acrylic resin. Aiming at the problems that the existing organic silicon coating is difficult to fully cure at normal temperature or low temperature, is insufficient in high-temperature resistance and cannot meet the long-term high-temperature protection requirement, the organic silicon high-temperature-resistant coating which can be cured at low temperature or even at normal temperature is prepared.

Description

Technical Field

[0001] This application relates to the field of new materials and their application technology, specifically to a low-temperature self-drying high-temperature resistant organosilicon coating and its preparation method. Background Technology

[0002] The stable operation of equipment in high-temperature environments relies on the protection of high-performance high-temperature resistant coatings. From engine components in the aerospace field to high-temperature pipelines in the power industry, and furnace equipment in the metallurgical industry, high-temperature resistant coatings can effectively resist the thermal oxidation and erosion of the base material by high temperatures, significantly extending the service life of the equipment. Currently, silicone coatings exhibit significant advantages in high-temperature resistance. However, they often fail to fully cure at room temperature or low temperatures, requiring baking at ≥200℃ to initiate the curing reaction. To address the challenge of low-temperature curing, the industry commonly employs modified silicone resins, such as epoxy-modified, polyester-modified, and phenolic-modified resins. While modified silicone resins can lower the curing temperature to some extent, this modification also brings negative impacts, namely reducing the coating's original excellent heat resistance and making it difficult to meet the demands of applications requiring extremely high high-temperature performance. Furthermore, existing high-temperature resistant coatings also face discoloration issues during long-term use. Due to uneven heating of the coating surface, some organic components are prone to decomposition and carbonization at high temperatures, leading to discoloration on the coating. This not only affects the aesthetic appearance but may also indicate damage to the internal structure of the coating, resulting in cracking and peeling, ultimately failing to meet long-term high-temperature protection requirements and impacting its protective performance and service life. Summary of the Invention

[0003] To address the problem that existing silicone coatings are difficult to fully cure at room temperature or low temperature and have insufficient high-temperature resistance, this application provides a low-temperature self-drying high-temperature resistant silicone coating and its preparation method.

[0004] In the first aspect, this application provides a low-temperature self-drying, high-temperature resistant silicone coating, which adopts the following technical solution: A low-temperature self-drying, high-temperature resistant silicone coating, comprising component A and component B; component A includes 45-55 parts resin, 25-35 parts modified filler, 25-30 parts solvent, 0.5-1 part anti-settling agent, 0.2-0.5 parts leveling agent, 0.3-0.8 parts defoamer, and 1-1.5 parts catalyst 1; component B includes curing agent and catalyst 2; the resin includes hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin.

[0005] By adopting the above technical solutions, hyperbranched epoxy phenyl silicone resin provides high-density crosslinking points, accelerating self-drying, and the phenyl conjugated structure can improve high-temperature resistance. The addition of linear methyl silicone resin allows its flexible long chains to interpenetrate within the hyperbranched resin network, preventing coating embrittlement. Furthermore, its high Si-O bond energy provides basic heat resistance, and its hydroxyl groups participate in crosslinking, supplementing reaction sites and increasing the crosslinking rate. Amino-modified acrylic resin, through side-chain amino groups embedded in the network, reacts with epoxy groups to form stable chemical bonds, enhancing cohesion and adhesion. Acrylic segments accelerate crosslinking, carbonizing at high temperatures to form a protective carbon layer, enhancing high-temperature resistance and density. The addition of modified fillers improves interfacial compatibility and temperature resistance, further reducing porosity and increasing density. The addition of solvents and catalysts further accelerates self-drying. Component B, the curing agent, can crosslink with component A at low temperatures or even room temperature, thereby achieving low-temperature curing or even room-temperature curing of the high-temperature resistant silicone coating.

[0006] In one specific implementation scheme, the preparation method of the hyperbranched epoxy phenyl silicone resin includes the following steps: taking tetramethoxysilane, toluene and dibutyltin dilaurate, heating to 70-80℃, adding a mixture of phenyltrimethoxysilane and epoxypropyltrimethoxysilane dropwise, keeping the reaction at the temperature for 3-4 hours, and then distilling under reduced pressure to obtain the hyperbranched epoxy phenyl silicone resin.

[0007] The mass ratio of the tetramethoxysilane to the phenyltrimethoxysilane is 1:(2-4).

[0008] By adopting the above technical solution, tetramethoxysilane is selected as the core, providing multiple reaction sites that facilitate the growth of branched structures. Phenylacetyltrimethoxysilane introduces phenyl groups, enhancing the resin's high-temperature resistance and molecular chain rigidity. Epioxypropyltrimethoxysilane introduces epoxy groups, giving the resin the activity to undergo ring-opening crosslinking with amino groups, resulting in a hyperbranched epoxyphenyl silicone resin with a hyperbranched three-dimensional network structure containing phenyl and epoxy functional groups. The conjugated structure of the phenyl group enhances high-temperature resistance, while the epoxy groups can undergo curing crosslinking reactions with component B, inhibiting molecular chain movement and forming a stable three-dimensional network structure, further enhancing high-temperature resistance. Furthermore, the hyperbranched structure provides a high density of crosslinking points, accelerating self-drying. Insufficient phenyltrimethoxysilane content reduces the coating's conjugated properties, making it prone to cracking at high temperatures and reducing its temperature resistance. Excessive tetramethoxysilane content leads to excessive local crosslinking, forming an uneven network, affecting coating uniformity, and consequently impacting the overall coating curing and drying time.

[0009] In one specific implementation, the mass ratio of the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin is (2.8-4.2):2:(0.8-1.5).

[0010] By adopting the above-mentioned technical solutions, the combination of hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin in the proportions specified in this application can enable the coating to possess good high-temperature resistance and self-drying properties, while simultaneously improving coating density, thereby preventing oxidation and reducing color difference. If the content of hyperbranched epoxy phenyl silicone resin is too low, the number of crosslinking points decreases, the self-drying speed slows down, and this affects the density of the crosslinking network, leading to color difference due to high-temperature oxidation and a decrease in high-temperature resistance. If the content of linear methyl silicone resin is too low, the coating becomes too rigid and lacks flexibility, making it prone to cracking at high temperatures. The amino groups in the amino-modified acrylic resin react with the epoxy groups to form stable chemical bonds, and the acrylic segments carbonize at high temperatures to form a protective carbon layer. If the proportion of this carbon layer is too high, the coating cohesion becomes too strong, reducing adhesion to the substrate, which may lead to brittleness, peeling, and prolonged self-drying time.

[0011] The modified filler includes modified nano-titanium dioxide.

[0012] Preferably, the preparation method of modified nano-titanium dioxide includes: dispersing nano-titanium dioxide in water, adding aluminum sulfate solution dropwise, adjusting the pH to 8-9 with ammonia water, reacting for 2-3 hours to obtain Al2O3-coated nano-titanium dioxide; then dispersing it in toluene, adding KH570, reacting at 70-80℃ for 2-3 hours, filtering and drying to obtain modified nano-titanium dioxide.

[0013] The modified filler includes dopamine-modified boron nitride.

[0014] Preferably, the preparation method of dopamine-modified boron nitride includes: dispersing boron nitride in Tris buffer, adding dopamine hydrochloride, stirring and filtering, then dispersing it in toluene, adding KH560, and reacting at 70-80℃ for 3-4 hours.

[0015] Preferably, the mass ratio of modified nano-titanium dioxide to dopamine-modified boron nitride is 1:(3-5).

[0016] By employing the above technical solutions, Al2O3-coated nano-titanium dioxide modification can inhibit photocatalysis, prevent coating aging, and enhance its antioxidant capacity, thereby preventing high-temperature color difference. KH570 grafting allows the modified nano-titanium dioxide to be uniformly dispersed in the resin and participate in cross-linking, thus improving interfacial bonding, density, oxygen penetration, temperature resistance, preventing coating cracking, and enhancing weather resistance. Dopamine-coated boron nitride prevents boron nitride agglomeration at high temperatures. The participation of silane groups in cross-linking disperses the silane groups of dopamine-modified boron nitride in the cross-linking network, and its layered structure can block heat conduction, improving the coating's high-temperature resistance. The combined use of modified nano-titanium dioxide and dopamine-modified boron nitride enhances the overall performance of the coating, blocking heat conduction and oxygen penetration, further improving the coating's weather resistance and anti-discoloration properties.

[0017] Secondly, this application provides a method for preparing a low-temperature self-drying, high-temperature resistant organosilicon coating, using the following technical solution: A method for preparing a low-temperature self-drying high-temperature resistant organosilicon coating includes the following steps: (1) mixing the resin of component A in proportion, then adding modified filler, solvent, anti-settling agent, leveling agent, defoamer, and catalyst at 1500-600r / min for 45-60min to obtain component A; (2) Mix component B, then mix component A and component B to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0018] The stirring and mixing step (1) is performed at 800-1000 r / min for 30-45 min.

[0019] In summary, this application has the following beneficial effects: 1. Hyperbranched epoxy phenyl silicone resin provides high-density crosslinking points, accelerating self-drying, and the phenyl conjugated structure improves high-temperature resistance. The addition of linear methyl silicone resin allows its flexible long chains to interpenetrate within the hyperbranched resin network, preventing coating embrittlement. Amino-modified acrylic resin, through its side-chain amino groups embedded in the network, reacts with epoxy groups to form stable chemical bonds, enhancing cohesion and adhesion. Modified fillers further improve interfacial compatibility and temperature resistance, reducing porosity and increasing density. The addition of solvents and catalysts further accelerates self-drying. Component B, the curing agent, can crosslink with component A at low temperatures or even room temperature, enabling low-temperature or even room-temperature curing of the high-temperature resistant silicone coating.

[0020] 2. Al2O3-coated nano-titanium dioxide modification can inhibit photocatalysis, prevent coating aging, enhance its antioxidant capacity, and thus prevent high-temperature color difference. Modified nano-titanium dioxide can be uniformly dispersed in the resin to participate in cross-linking, thereby improving interfacial bonding, increasing density, blocking oxygen penetration, improving temperature resistance, preventing coating cracking, and enhancing weather resistance. Dopamine-coated boron nitride can prevent boron nitride agglomeration at high temperatures. The silane groups participate in cross-linking, dispersing the silane groups of dopamine-modified boron nitride in the cross-linking network. Its layered structure can block heat conduction and improve the coating's high-temperature resistance. The combined use of these two technologies improves the overall performance of the coating, blocking heat conduction and oxygen penetration, further enhancing the coating's weather resistance and anti-discoloration properties. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the embodiments.

[0022] raw material Some of the raw materials used in the preparation examples and embodiments: Linear methyl silicone resin: Dow Chemical TM3145; Acrylic resin model: BM65C; Tetramethoxysilane purchased from Bailingwei Technology; Phenylenetrimethoxysilane, item number: T39100, purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.; Epichlorohydrin trimethoxysilane, model: KH-560; Anti-settling agent, model: Evonik AEROSIL 200; Leveling agent, model: BYK-333; Defoamer, model: Dow Corning DC-65; Nano titanium dioxide, model: JWN-TO-R30; Dopamine hydrochloride purchased from Hubei Hongfuda Biotechnology Co., Ltd.; Tris buffer (0.5mol / L), purchased from Shanghai Yueteng Biotechnology Co., Ltd.; Nano boron nitride, item number: XH-BN-100, purchased from Shanghai Xiaohuang Nanotechnology Co., Ltd.; Solvent: Cyclohexanone:Propylene glycol butyl ether, mass ratio 3:2; Catalyst 1: Bismuth isooctanoate, model: 83; Catalyst 2 is 2-ethyl-4-methylimidazolium; Curing agent is amino silicone resin, model: CS-2020, purchased from Wuxi Xiano New Material Technology Co., Ltd. Unless otherwise specified, all raw materials used in the examples and comparative examples are commercially available products.

[0023] Preparation Example 1 Preparation of hyperbranched epoxy phenyl silicone resin: Take 120g tetramethoxysilane, 800ml toluene and 3g dibutyltin dilaurate, heat to 80℃, add dropwise a mixture of 360g phenyltrimethoxysilane and 100g epoxypropyltrimethoxysilane, keep the reaction at the temperature for 4h, then distill under reduced pressure for 30min at a vacuum degree of -0.095MPa to obtain hyperbranched epoxy phenyl silicone resin.

[0024] Preparation Example 2 Preparation of hyperbranched epoxy phenyl silicone resin: Take 240g tetramethoxysilane, 800ml toluene and 3g dibutyltin dilaurate, heat to 80℃, add dropwise a mixture of 240g phenyltrimethoxysilane and 100g epoxypropyltrimethoxysilane, keep the reaction at the temperature for 4h, then distill under reduced pressure for 30min at a vacuum degree of -0.095MPa to obtain hyperbranched epoxy phenyl silicone resin.

[0025] Preparation Example 3 Preparation of hyperbranched epoxy phenyl silicone resin: Take 80g tetramethoxysilane, 800ml toluene and 3g dibutyltin dilaurate, heat to 80℃, add dropwise a mixture of 400g phenyltrimethoxysilane and 100g epoxypropyltrimethoxysilane, keep the reaction at the temperature for 4h, then distill under reduced pressure for 30min at a vacuum degree of -0.095MPa to obtain hyperbranched epoxy phenyl silicone resin.

[0026] Preparation Example 3 Take 400g of acrylic resin, heat it to 80℃, add 100ml of toluene solution containing 20g of 3-aminopropyltrimethoxysilane, react for 3h, then distill under reduced pressure for 40min at a vacuum of -0.095MPa to obtain amino-modified acrylic resin.

[0027] Preparation Example 5 Preparation of modified nano-titanium dioxide: 20g of nano-titanium dioxide was dispersed in 200mL of water, 100g of 10% aluminum sulfate solution was added dropwise, the pH was adjusted to 9 with ammonia water, and the reaction was carried out for 2h to obtain Al2O3 coated product; then it was dispersed in 200mL of toluene, 5g of KH570 was added, the reaction was carried out at 80℃ for 3h, filtered, washed with toluene, and vacuum dried at 60℃ for 6h to obtain modified nano-titanium dioxide.

[0028] Preparation Example 6 Preparation of dopamine-modified boron nitride: 10g of nano boron nitride was dispersed in 100mL of Tris buffer, 2g of dopamine hydrochloride was added, and the mixture was stirred for 24h and then filtered. The mixture was then dispersed in 150mL of toluene, 3g of KH560 was added, and the mixture was reacted at 80℃ for 4h under nitrogen protection. After cooling to room temperature, the mixture was filtered, washed twice with ethanol, and dried under vacuum at 60℃ for 6h to obtain dopamine-modified boron nitride.

[0029] Example 1 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4 with a mass ratio of 1:3 and the dopamine-modified boron nitride prepared in Preparation Example 5. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0030] Example 2 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 32.5:2:1.5. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4 and the dopamine-modified boron nitride prepared in Preparation Example 5 with a mass ratio of 1:3. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0031] Example 3 A low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 4.2:1:0.8. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4 and the dopamine-modified boron nitride prepared in Preparation Example 5 with a mass ratio of 1:3. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0032] Example 4 A low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3:1:2. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4 and the dopamine-modified boron nitride prepared in Preparation Example 5 with a mass ratio of 1:3. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0033] Example 5 A low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4 and the dopamine-modified boron nitride prepared in Preparation Example 5 with a mass ratio of 1:1. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0034] Example 6 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4 with a mass ratio of 1:6 and the dopamine-modified boron nitride prepared in Preparation Example 5. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0035] Example 7 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is a hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is nano-titanium dioxide with a mass ratio of 1:3 and dopamine-modified boron nitride prepared in Preparation Example 5. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0036] Example 8 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8, and the modified filler is the modified nano-titanium dioxide and boron nitride prepared in Preparation Example 4 with a mass ratio of 1:3. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0037] Example 9 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0038] Example 10 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is the dopamine-modified boron nitride prepared in Preparation Example 5. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0039] Comparative Example 1 A low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is hyperbranched epoxy phenyl silicone resin and linear methyl silicone resin prepared in Preparation Example 1 at a mass ratio of 4:2. The modified filler is modified nano-titanium dioxide prepared in Preparation Example 4 at a mass ratio of 1:3 and dopamine-modified boron nitride prepared in Preparation Example 5. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0040] Comparative Example 2 A low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin prepared in Preparation Example 1 with a mass ratio of 5.2:0.8 and the amino-modified acrylic resin prepared in Preparation Example 6. The modified filler is the modified nano-titanium dioxide prepared in Preparation Example 4 with a mass ratio of 1:3 and the dopamine-modified boron nitride prepared in Preparation Example 5. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0041] Comparative Example 3 A low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin obtained in Preparation Example 1. The modified filler is the modified nano-titanium dioxide obtained in Preparation Example 4 and the dopamine-modified boron nitride obtained in Preparation Example 5, with a mass ratio of 1:3. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0042] Comparative Example 4 A low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is nano-titanium dioxide and boron nitride with a mass ratio of 1:3. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0043] Comparative Example 5 A low-temperature self-drying, high-temperature resistant silicone coating is composed of component A and component B. Component A includes 100g of resin, 50g of modified filler, 60g of solvent, and 1-1.5 parts of catalyst 1. Component B includes 500g of curing agent, 20g of catalyst 2, and 320g of xylene. The resin is the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin prepared in Preparation Example 1 with a mass ratio of 3.2:2:0.8. The modified filler is boron nitride. (1) First, stir the resin of component A at 1000r / min for 30min according to the proportion, then add the modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst 1, stir at 600r / min for 60min to obtain component A; (2) Mix component B according to the proportion, then mix component A and component B at a mass ratio of 10:1 to obtain a low-temperature self-drying high-temperature resistant silicone coating.

[0044] Performance testing Components A and B obtained in Examples 1-10 and Comparative Examples 1-5 were mixed in a specific weight ratio to prepare a low-temperature self-drying, high-temperature resistant silicone coating. The coating material was then applied to the surface of a substrate to obtain a 40 μm thick coating for performance testing. The performance testing was conducted using the following methods: a. High temperature resistance test: 600℃, 100h; refer to GB / T 1735-2009; b. Adhesion test: Tested according to GB / T 1720-1979 standard; c. Drying time: Refer to GB / T 6739-2006; the maximum pencil hardness of 2H without permanent scratches is used as the hardness grade of the paint film, and the properties are shown in Table 1: Table 1 Performance Test Results As shown in Table 1, compared with Examples 1-4 and Comparative Examples 1-3, the combination of hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin within the scope of this application can give the coating good high-temperature resistance and self-drying properties, while improving the coating density, thereby preventing oxidation and reducing color difference. If the content of hyperbranched epoxy phenyl silicone resin is too low, the number of crosslinking points will decrease, the self-drying speed will be slower, and the density of the crosslinking network will be affected, resulting in color difference due to high-temperature oxidation and a decrease in high-temperature resistance. If the content of linear methyl silicone resin is too low, the coating will be too rigid and lack flexibility, making it prone to cracking at high temperatures. The amino groups of amino-modified acrylic resin react with epoxy groups to form stable chemical bonds, and the acrylic segments carbonize at high temperatures to form a protective carbon layer. If the proportion of amino-modified acrylic resin is too high, the coating cohesion will be too strong, the adhesion to the substrate will be reduced, and the coating may become brittle and peel off, and the self-drying time will be prolonged.

[0045] Compared with Examples 5-10 and Comparative Examples 4-5, Al2O3-coated nano-titanium dioxide modification enhances its antioxidant capacity, thereby preventing high-temperature color difference and improving interfacial adhesion, preventing coating cracking; dopamine-coated boron nitride improves the coating's high-temperature resistance. The combined use of modified nano-titanium dioxide and dopamine-modified boron nitride improves the overall performance of the coating, blocking heat conduction and oxygen penetration, further enhancing the coating's weather resistance and anti-discoloration properties.

[0046] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A low-temperature self-drying, high-temperature resistant silicone coating, characterized in that: The low-temperature self-drying high-temperature resistant silicone coating is composed of component A and component B; component A includes 45-55 parts resin, 25-35 parts modified filler, 25-30 parts solvent, 0.5-1 part anti-settling agent, 0.2-0.5 parts leveling agent, 0.3-0.8 parts defoamer, and 1-1.5 parts catalyst 1; component B includes curing agent and catalyst 2; the resin includes hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin.

2. The low-temperature self-drying, high-temperature resistant organosilicon coating according to claim 1, characterized in that: The preparation method of the hyperbranched epoxy phenyl silicone resin includes the following steps: take tetramethoxysilane, toluene and dibutyltin dilaurate, heat to 70-80℃, add a mixture of phenyltrimethoxysilane and epoxypropyltrimethoxysilane dropwise, keep the reaction at the temperature for 3-4 hours and then distill under reduced pressure to obtain hyperbranched epoxy phenyl silicone resin.

3. The low-temperature self-drying, high-temperature resistant silicone coating according to claim 2, characterized in that: The mass ratio of the tetramethoxysilane to the phenyltrimethoxysilane is 1:(2-4).

4. The low-temperature self-drying, high-temperature resistant silicone coating according to claim 1, characterized in that: The mass ratio of the hyperbranched epoxy phenyl silicone resin, linear methyl silicone resin, and amino-modified acrylic resin is (2.8-4.2):2:(0.8-1.5).

5. The low-temperature self-drying, high-temperature resistant silicone coating according to claim 1, characterized in that: Modified fillers include modified nano-titanium dioxide.

6. The low-temperature self-drying, high-temperature resistant organosilicon coating according to claim 1, characterized in that: The modified filler includes dopamine-modified boron nitride.

7. The method for preparing the low-temperature self-drying, high-temperature resistant organosilicon coating according to any one of claims 1-6, characterized in that, The process includes the following steps: (1) Mix the resin of component A in proportion, then add modified filler, solvent, anti-settling agent, leveling agent, defoamer and catalyst. Stir at 1500-600r / min for 45-60min to obtain component A; (2) Mix component B, then mix component A and component B to obtain a low-temperature self-drying high-temperature resistant silicone coating.

8. The method for preparing the low-temperature self-drying, high-temperature resistant organosilicon coating according to claim 7, characterized in that: The stirring and mixing in (1) is carried out at 800-1000 r / min for 30-45 min.

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