Organosilicon coatings, ceramicizable organosilicon elastomer coatings and their preparation methods

Abstract

This invention provides an organosilicon coating, a ceramicizable organosilicon elastomer coating, and a preparation method thereof. The organosilicon coating comprises methyl vinyl silicone oil, methyl vinyl phenyl silicone oil, a first organic solvent, fumed silica, MoS2 / MXene micro / nano heterostructure powder, cerium oxide, polytetrafluoroethylene micropowder, perfluoropolyether, a heat-resistant agent, and a high-temperature oxidant. The organosilicon coating of this invention has low viscosity, making it easy to apply. The coating material formed by it has high mechanical strength, with a tensile strength exceeding 6 MPa, excellent heat resistance, and theoretically can withstand short-term temperatures up to 1300℃. It exhibits good stability and comprehensive mechanical properties at high temperatures and can rapidly form a hard ceramicized shell under flame conditions, demonstrating excellent flame-retardant and fire-resistant properties.

Description

Technical Field

[0001] This invention relates to an organosilicon elastomer material, specifically to an organosilicon coating, a high-temperature resistant, high-mechanical-strength, ceramizable organosilicon elastomer coating formed therefrom, its preparation method, and its application. Background Technology

[0002] Silicone rubber's main chain contains Si-O bonds with a bond energy of 422.5 kJ / mol, significantly higher than the 344.4 kJ / mol of CO and CC. Therefore, compared to other polymer materials, silicone rubber possesses superior temperature resistance, and most types can be used continuously at 200℃. Furthermore, silicone rubber's excellent cold resistance, insulation, and chemical stability make it widely used in aerospace, electronics, automotive, and medical fields.

[0003] Methyl vinyl silicone rubber, a major class of silicone rubber, inherits the advantages of dimethyl silicone rubber and broadens the range of vulcanizing agents. In recent years, it has gradually replaced dimethyl silicone rubber. The main chain of methyl vinyl silicone rubber is Si-O-Si, with vinyl side chains and C=C bonds. Its structure does not contain other large or polar groups, resulting in high flexibility but low strength. More critically, once the operating temperature exceeds 250℃, methyl vinyl silicone rubber will gradually decompose and age, becoming unusable at 300-350℃. The aging of methyl vinyl silicone rubber is mainly thermo-oxidative aging, including the oxidation reaction of side chain organic groups and the breaking of silicon-oxygen bonds in the main chain, accompanied by a series of rearrangement and crosslinking reactions. Under anaerobic, high-temperature, and sealed conditions, silicone rubber mainly undergoes main chain cleavage and elastomer degradation, leading to softening. Under aerobic, high-temperature, and open environments, side group oxidation mainly occurs, forming free radicals and undergoing coupling reactions, resulting in crosslinking and hardening of the silicone rubber, thus limiting its application.

[0004] Researchers have developed a high-resilience heat-resistant silicone rubber using methyl vinyl silicone rubber raw material, silica, silane coupling agent and heat-resistant filler. It can maintain more than 80% of its mechanical properties and more than 70% of its resilience after aging at 220°C for 168 hours. However, at higher temperatures, the material becomes hard and brittle, and its resilience and mechanical properties decrease significantly.

[0005] To improve the heat resistance of silicone rubber, researchers have explored various methods. For example, they have used iron oxide and cerium oxide to enhance the heat resistance of silicone rubber and discovered a synergistic heat-strengthening effect between the two. However, the prepared silicone rubber can only be used for 24 hours at 300°C and cannot be used long-term at high temperatures. Other methods have proposed, such as filling with montmorillonite, using iron oxide / cerium oxide / copper oxide / nickel oxide composites, metal ion modifiers, iron-based polysilazane, and rare-earth samarium complexes. However, these methods are either complex to manufacture and have low industrialization value, or they improve heat resistance but reduce mechanical properties such as strength, thus failing to meet the needs of large-scale practical applications. Summary of the Invention

[0006] The main objective of this invention is to provide an organosilicon coating, a ceramicizable organosilicon elastomer coating, its preparation method and application, in order to overcome the shortcomings of the prior art.

[0007] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows.

[0008] A first aspect of the present invention provides an organosilicon coating comprising component A and component B;

[0009] Component A comprises the following components by weight: 10-30 parts methyl vinyl silicone oil, 5-30 parts methyl vinyl phenyl silicone oil, 16-50 parts first organic solvent, 5-20 parts fumed silica, 0-1% MoS2 / MXene micro / nano heterostructure powder, 2-10 parts cerium oxide, 2-10 parts polytetrafluoroethylene micro powder, 0.3-1.5 parts perfluoropolyether, and 2-10 parts heat resistant agent, wherein the amount of MoS2 / MXene micro / nano heterostructure powder is not 0.

[0010] Component B includes a high-temperature oxidant.

[0011] In one embodiment, the method for preparing the MoS2 / MXene micro / nano heterostructure powder includes: subjecting a mixed reaction system containing a sulfur source, a molybdenum source, a reducing agent, and MXene powder to a hydrothermal reaction at 100-140°C for 18-24 hours to obtain the MoS2 / MXene micro / nano heterostructure powder, wherein the molar ratio of the sulfur source, molybdenum source, and reducing agent is 50-150:10-30:1-5, and the molar ratio of the molybdenum source to the MXene powder is 10-30 mmol:1.3 g.

[0012] Furthermore, the sulfur source includes, but is not limited to, thiourea, methiopyrimidine, or propylthiopyrimidine.

[0013] Furthermore, the molybdenum source includes, but is not limited to, soluble molybdates such as ammonium molybdate, sodium molybdate, or potassium molybdate.

[0014] Furthermore, the reducing agent includes, but is not limited to, citric acid, malic acid, or dicopper histidine.

[0015] In one embodiment, the phenyl and vinyl contents of the methyl vinylphenyl silicone oil are 15-45 mol% and 5-15 mol%, respectively.

[0016] In one embodiment, the first organic solvent comprises, but is not limited to, one or more of n-heptane, cyclohexane, and petroleum ether. Further, component A comprises 10-30 parts n-heptane, 5-15 parts cyclohexane, and 1-5 parts petroleum ether; when component A is mixed with component B, this composite solvent exhibits stronger solubility for high-temperature oxidants.

[0017] In one embodiment, the high-temperature oxidant includes one or more combinations of benzoyl peroxide and tert-butyl peroxide, but is not limited thereto.

[0018] In one embodiment, the second solvent includes, but is not limited to, butyl acetate, etc.

[0019] Furthermore, component B comprises the following components in parts by weight: 2-5 parts benzoyl peroxide, 1-3 parts tert-butyl peroxide, and 92-97 parts a second organic solvent. The coating formed by mixing component B with component A has a relatively low viscosity and is easier to apply.

[0020] In one embodiment, the heat-resistant agent includes one or more combinations of titanium diboride and hollow glass microspheres, but is not limited thereto.

[0021] A second aspect of the present invention provides a ceramizable organosilicon elastomer coating formed from the organosilicon coating described in the present invention.

[0022] A third aspect of the present invention provides a method for preparing the ceramizable organosilicon elastomer coating, comprising:

[0023] A mixed reaction system containing a sulfur source, a molybdenum source, a reducing agent, and MXene powder was subjected to hydrothermal reaction at 100-140℃ for 18-24 h to obtain MoS2 / MXene micro / nano heterostructure powder. The molar ratio of sulfur source, molybdenum source, and reducing agent was 50-150:10-30:1-5, and the molar ratio of molybdenum source to MXene powder was 10-30 mmol:1.3 g.

[0024] Component A is obtained by uniformly mixing methyl vinyl silicone oil, methyl vinyl phenyl silicone oil, a first organic solvent, fumed silica, MoS2 / MXene micro / nano heterostructure powder, cerium oxide, polytetrafluoroethylene micro powder, perfluoropolyether and heat resistant agent.

[0025] Component B was prepared using a high-temperature oxidant;

[0026] After uniformly mixing components A and B, the mixture is coated onto a substrate and heated at 80-120℃ for 2-6 hours, then left at room temperature for more than 7 days to obtain the ceramicizable organosilicon elastomer coating.

[0027] The method of applying the silicone coating to the substrate includes, but is not limited to, spraying, roller coating, or dip coating.

[0028] For example, after the silicone coating is applied to the substrate, it can be heated at 100°C for 4 hours and then left at room temperature for 7 days to obtain the ceramicizable silicone elastomer coating.

[0029] In one embodiment, the method specifically includes: uniformly mixing all components used to form component A, grinding them, and then passing them through a 100-150 mesh sieve to obtain component A.

[0030] A fourth aspect of the present invention provides a high-temperature resistant protective structure comprising the aforementioned ceramizable organosilicon elastomer coating.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] 1) By adding MoS2 / MXene micro / nano heterostructure powder to the ceramizable organosilicon elastomer coating of the present invention, not only can the hydroxyl groups on MoS2 / MXene enhance its dispersibility in vinylphenyl silicone resin, but its electrical properties can also delay the aging of the coating material caused by ultraviolet rays and high temperatures. It can also act as an anchor point to increase the crosslinking density of the coating, and can also play a role in layer coupling, comprehensively improving the mechanical properties and flame retardancy of the coating material, as well as improving the gas barrier properties of the coating material. In addition, when the coating material is ceramized at high temperature, the MoS2 / MXene micro / nano heterostructure can also chemically bond with the substrate of the coating to form a strong bond, thereby improving the bonding force between the ceramizable coating and the substrate.

[0033] 2) In the ceramicizable organosilicon elastomer coating of the present invention, by adding methyl vinyl phenyl silicone oil and the like to the raw materials, phenyl structural units can be introduced, which can effectively control the molecular chain structure composition of the coating and improve the heat resistance of the coating at the film-forming material end.

[0034] 3) The ceramizable organosilicon elastomer coating of this invention incorporates cerium oxide and polytetrafluoroethylene (PTFE) micropowder. These two components can self-composite to form a heat-resistant inorganic / organic composite filler, further increasing the coating's heat resistance temperature to over 350°C. Simultaneously, they synergistically work with the film-forming material to effectively prevent direct contact between MoS2 / MXene micro / nano heterostructure powder particles, significantly improving the nano-aggregation degree of the MoS2 / MXene micro / nano heterostructure powder, thus forming a unique "anchor point brick-and-mortar" structure. This "brick-and-mortar" structure makes the coating denser and enhances its isolation effect against external interference. When heat increases rapidly, the MoS2 / MXene micro / nano heterostructure powder, acting as the "bricks," exhibits a maze effect, synergistically acting as a physical barrier with the CeO2 / PTFE micropowder composite filler and dispersing stress concentration effects, thereby further enhancing the coating's thermal stability and overall mechanical properties under high-temperature conditions.

[0035] 4) In the ceramicizable organosilicon elastomer coating of the present invention, silicone oil, fumed silica, MoS2 / MXene micro-nano heterostructure powder, CeO2, etc. can undergo complex mutual reactions under flame conditions or other high temperature conditions to become ceramic, thereby rapidly forming a hard ceramicized shell with a porous structure. This shell has strong adhesion to the substrate and excellent flame retardant and fire resistant properties.

[0036] 5) The organosilicon coating of the present invention uses perfluoropolyether as one of the raw material components during preparation, which is beneficial to optimizing the dispersion effect of CeO2 / polytetrafluoroethylene micro powder composite filler and MoS2 / MXene micro-nano heterostructure powder, reducing the viscosity of the coating and improving the mechanical properties of the coating. Attached Figure Description

[0037] Figure 1 This is a schematic diagram illustrating the reaction mechanism of a ceramicizable organosilicon elastomer coating in a typical embodiment of the present invention.

[0038] Figure 2 This is a SEM image of a MoS2 / MXene micro / nano heterostructure powder from Example 1;

[0039] Figure 3 This is a SEM image of a MoS2 / MXene micro / nano heterostructure powder from Example 1. Detailed Implementation

[0040] The technical solutions of the present invention will be described in detail below with reference to specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention. The specific functional details disclosed herein should not be construed as limiting, but are merely intended to form the basis of the claims and to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0041] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0042] In the embodiments and comparative examples of this invention, some raw materials are self-made, and unless otherwise specified, other raw materials and reagents are commercially available.

[0043] For example, in the following examples and comparative examples, the polytetrafluoroethylene micro powder mainly used PTFE-200D, which was purchased from Nanjing Tianshi New Material Technology Co., Ltd.; methyl vinyl silicone rubber and methyl vinyl phenyl silicone rubber were purchased from Zhonglan Chenguang Chemical Research and Design Institute Co., Ltd.; cerium oxide (CeO2) was purchased from Shandong Xinghai Chemical Co., Ltd.; perfluoropolyether JHT-270 was purchased from Hangzhou Jufu New Material Technology Co., Ltd.; and MXene powder was Ti3C2MXene powder purchased from Forsmann Technology (Beijing) Co., Ltd.

[0044] The specific preparation methods of the MoS2 / MXene micro / nano heterostructure powder and methyl vinyl phenyl silicone oil used in the following examples and comparative examples are as follows.

[0045] The preparation of MoS2 / MXene micro / nano heterostructure powder (Xa) specifically includes the following process: 7 g of thiourea and 3.5 g of ammonium molybdate tetrahydrate were dispersed in 400 mL of deionized water and stirred for 15 minutes until fully mixed. Then, 1.3 g of MXene powder and 0.9 g of citric acid monohydrate were added to the solution and stirred at room temperature for 15 minutes until uniformly dispersed. Subsequently, the solution was transferred to a stainless steel autoclave lined with polytetrafluoroethylene and subjected to hydrothermal treatment at 120 °C for 20 hours. After separation by centrifugation at 8000 rpm for 10 minutes, the powder was washed three times with water and ethanol to obtain the MoS2 / MXene micro / nano heterostructure powder. The final product was obtained by vacuum drying at 70 °C overnight. SEM images of the MoS2 / MXene micro / nano heterostructure powder (Xa) prepared in this example are shown below. Figures 2-3 As shown.

[0046] The preparation of MoS2 / MXene micro / nano heterostructure powder (Xb) involved the following process: Methoxypyrimidine and sodium molybdate were dispersed in deionized water and stirred for 15 minutes until fully mixed. Subsequently, MXene powder and malic acid were added to the solution and stirred at room temperature for 15 minutes until uniformly dispersed. The molar ratio of methoxypyrimidine, sodium molybdate, and malic acid was approximately 10:6:1, and the molar ratio of sodium molybdate to MXene powder was approximately 10 mmol:1.3 g. Finally, the solution was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and subjected to hydrothermal treatment at 120 °C for 18 hours. After separation by centrifugation at 8000 rpm for 10 minutes, the powder was washed three times with water and ethanol to obtain the MoS2 / MXene micro / nano heterostructure powder. The final product was obtained by vacuum drying at 70 °C overnight.

[0047] The preparation of MoS2 / MXene micro / nano heterostructure powder (Xc) involved the following process: Propylthiouracil and potassium molybdate were dispersed in deionized water and stirred for 15 minutes until thoroughly mixed. Subsequently, MXene powder and dicopper histidine were added to the solution and stirred at room temperature for 15 minutes until uniformly dispersed. The molar ratio of propylthiouracil, potassium molybdate, and dicopper histidine was approximately 150:10:1, and the molar ratio of potassium molybdate to MXene powder was approximately 30 mmol:1.3 g. Finally, the solution was transferred to a polytetrafluoroethylene-lined stainless steel autoclave and subjected to hydrothermal treatment at 120 °C for approximately 24 hours. After separation by centrifugation at 8000 rpm for 10 minutes, the powder was washed three times with water and ethanol to obtain the MoS2 / MXene micro / nano heterostructure powder. The final product was obtained by vacuum drying at 70 °C overnight.

[0048] The preparation of methyl vinylphenyl silicone oil (M1) involves the following process: under nitrogen protection, methylphenyl dichlorosilane (28.7 g, 0.15 mol), methyl vinyl dichlorosilane (14.1 g, 0.1 mol), and dimethyl diethoxysilane (103.7 g, 0.7 mol) are mixed evenly and added dropwise to an ice-salt bath at -5°C. After 6 hours of addition, the temperature is raised to room temperature and the reaction continues for 12 hours. Then, trimethylchlorosilane (5.5 g, 0.05 mol) is slowly added dropwise to carry out the end-capping reaction. The temperature is then raised to 80°C and the reaction continues for 12 hours. Low-boiling substances are removed by vacuum distillation to obtain methyl vinylphenyl silicone oil M1 (15% Ph group, 10% vinyl Vi; unless otherwise specified, all values ​​refer to mol%).

[0049] The synthetic route for this methyl vinyl phenyl silicone oil is as follows:

[0050]

[0051] The preparation of methyl vinylphenyl silicone oil (M2) involves the following process: Under nitrogen protection, methylphenyl dichlorosilane (57.4 g, 0.3 mol), methyl vinyl dichlorosilane (14.1 g, 0.1 mol), and dimethyl diethoxysilane (81.5 g, 0.55 mol) are mixed evenly and added dropwise to an ice-salt bath at -5°C. After 6 hours of addition, the temperature is raised to room temperature and the reaction continues for 12 hours. Then, trimethylchlorosilane (5.5 g, 0.05 mol) is slowly added dropwise to carry out the end-capping reaction. The temperature is then raised to 80°C and the reaction continues for 12 hours. Finally, low-boiling substances are removed by vacuum distillation to obtain methyl vinylphenyl silicone oil M2 (30% Ph-based, 10% Vi).

[0052] The preparation of methyl vinylphenyl silicone oil (M3) involves the following process: Under nitrogen protection, methylphenyl dichlorosilane (86.1 g, 0.45 mol), methyl vinyl dichlorosilane (14.1 g, 0.1 mol), and dimethyl diethoxysilane (59.3 g, 0.4 mol) are mixed evenly and added dropwise to an ice-salt bath at -5°C. After 6 hours of addition, the temperature is raised to room temperature and the reaction continues for 12 hours. Then, trimethylchlorosilane (5.5 g, 0.05 mol) is slowly added dropwise to carry out the end-capping reaction. The temperature is then raised to 80°C and the reaction continues for 12 hours. Finally, low-boiling substances are removed by vacuum distillation to obtain methyl vinylphenyl silicone oil M3 (45% Ph-based, 10% Vi).

[0053] The preparation of methyl vinylphenyl silicone oil (M4) involves the following process: Under nitrogen protection, methylphenyl dichlorosilane (57.4 g, 0.3 mol), methyl vinyl dichlorosilane (7.1 g, 0.05 mol), and dimethyl diethoxysilane (88.9 g, 0.6 mol) are mixed evenly and added dropwise to an ice-salt bath at -5°C. After 6 hours of addition, the temperature is raised to room temperature and the reaction continues for 12 hours. Then, trimethylchlorosilane (5.5 g, 0.05 mol) is slowly added dropwise to carry out the end-capping reaction. The temperature is then raised to 80°C and the reaction continues for 12 hours. Finally, low-boiling substances are removed by vacuum distillation to obtain methyl vinylphenyl silicone oil M4 (30% Ph-based, 5% Vi).

[0054] The preparation of methyl vinylphenyl silicone oil (M5) involves the following process: Under nitrogen protection, methylphenyl dichlorosilane (57.4 g, 0.3 mol), methyl vinyl dichlorosilane (21.2 g, 0.15 mol), and dimethyl diethoxysilane (74.1 g, 0.5 mol) are mixed evenly and added dropwise to an ice-salt bath at -5°C. After 6 hours of addition, the temperature is raised to room temperature and the reaction continues for 12 hours. Then, trimethylchlorosilane (5.5 g, 0.05 mol) is slowly added dropwise to carry out the end-capping reaction. The temperature is then raised to 80°C and the reaction continues for 12 hours. Finally, low-boiling substances are removed by vacuum distillation to obtain methyl vinylphenyl silicone oil M5 (30% Ph-based, 15% Vi).

[0055] Preparation of component A1: 18.7 parts of methyl vinyl silicone oil (unless otherwise specified, all parts are by weight), 16 parts of methyl vinyl phenyl silicone oil (M1), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-2701, and 6 parts of titanium diboride were mixed and dispersed at high speed at 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. Component A1 was obtained by filtering with a 120-mesh copper mesh.

[0056] Preparation of component A2: 10 parts of methyl vinyl silicone oil, 28 parts of methyl vinyl phenyl silicone oil (M2), 10 parts of n-heptane, 15 parts of cyclohexane, 5 parts of petroleum ether, 10 parts of fumed silica, 0.8 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 2.7 parts of cerium oxide, 5 parts of PTFE-200D, 1.5 parts of perfluoropolyether JHT-270, and 10 parts of titanium diboride were mixed and dispersed at high speed at 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. Component A2 was obtained by filtering with a 120-mesh copper mesh.

[0057] Preparation of component A3: 28 parts of methyl vinyl silicone oil, 5 parts of methyl vinyl phenyl silicone oil (M3), 16.4 parts of n-heptane, 5.2 parts of cyclohexane, 1 part of petroleum ether, 20 parts of fumed silica, 0.1 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 10 parts of cerium oxide, 10 parts of PTFE-200D, 0.3 parts of perfluoropolyether JHT-270, and 2 parts of titanium diboride were mixed and dispersed at high speed at 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. Component A3 was obtained by filtering with a 120-mesh copper mesh.

[0058] Preparation of component A4: 23 parts of methyl vinyl silicone oil, 20 parts of methyl vinyl phenyl silicone oil (M4), 15 parts of n-heptane, 15 parts of cyclohexane, 2.5 parts of petroleum ether, 5 parts of fumed silica, 0.5 parts of MoS2 / MXene micro / nano heterostructure powder (Xb), 5 parts of cerium oxide, 5 parts of PTFE-200D, 1 part of perfluoropolyether JHT-2701, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. Component A4 was obtained by filtering with a 120-mesh copper mesh.

[0059] Preparation of component A5: 18.7 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M5), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MoS2 / MXene micro / nano heterostructure powder (Xc), 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-2701, and 6 parts of titanium diboride were dispersed at 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The mixture was then filtered through a 120-mesh copper mesh to obtain component A5.

[0060] Preparation of component A6: 18.7 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M2), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-2701, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. Component A6 was obtained by filtering with a 120-mesh copper mesh.

[0061] Preparation of component A7: 18.1 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M2), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.9 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-2701, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. Component A7 was obtained by filtering with a 120-mesh copper mesh.

[0062] Preparation of component A1a: 19 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M1), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-270, and 6 parts of titanium diboride were mixed and dispersed at 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The mixture was then filtered through a 120-mesh copper screen to obtain component A1a.

[0063] Preparation of component A1b: 34.7 parts of methyl vinyl silicone oil, 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-270, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The mixture was then filtered through a 120-mesh copper mesh to obtain component A1b.

[0064] Preparation of component A1c: 22.7 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M1), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 5 parts of cerium oxide, 1 part of perfluoropolyether JHT-270, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The A1c component was obtained by filtering with a 120-mesh copper mesh.

[0065] Preparation of component A1d: 23.7 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M1), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-270, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The A1d component was obtained by filtering with a 120-mesh copper screen.

[0066] Preparation of component A1e: 19.7 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M1), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MoS2 / MXene micro / nano heterostructure powder (Xa), 5 parts of cerium oxide, 4 parts of PTFE-200D, and 6 parts of titanium diboride were mixed and dispersed at 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The A1e component was obtained by filtering with a 120-mesh copper screen.

[0067] Preparation of component A1f: 18.7 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M1), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of MXene powder, 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-270, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The A1f component was obtained by filtering with a 120-mesh copper screen.

[0068] Preparation of component A1g: 18.7 parts of methyl vinyl silicone oil, 16 parts of methyl vinyl phenyl silicone oil (M1), 18 parts of n-heptane, 9 parts of cyclohexane, 2 parts of petroleum ether, 18 parts of fumed silica, 0.3 parts of commercially available nano MoS2 powder (purchased from Xi'an Qiyue Biotechnology Co., Ltd.), 5 parts of cerium oxide, 4 parts of PTFE-200D, 1 part of perfluoropolyether JHT-270, and 6 parts of titanium diboride were mixed and dispersed at high speed of 1500 r / min for 30 min. Then, 2 parts of hollow glass microspheres were added and ground until the fineness was less than 40 micrometers. The mixture was then filtered through a 120-mesh copper mesh to obtain component A1g.

[0069] Preparation of component B1: Take 4 parts of benzoyl peroxide and 2 parts of tert-butyl peroxide, and fully dissolve them in 94 parts of butyl acetate solvent to prepare component B1.

[0070] The formulations of the organosilicon coatings in the following examples and comparative examples are shown in Tables 1-2. The preparation method includes: mixing components A and B at a mass ratio of 12:1, preparing the coating by air spraying, drying the coating surface, placing the test plate in a forced-air drying oven for heating and curing (100℃, 4h), and then placing it at room temperature for 7 days before testing the relevant properties of the coating. The test results are shown in Tables 3-8.

[0071] Figure 1 The reaction mechanism of a ceramicizable organosilicon elastomer coating in a typical embodiment of the present invention is shown. This coating has the characteristics of high temperature resistance and high mechanical strength.

[0072] The following tests were conducted: Panel preparation: according to GB / T 1727-1992 "General Methods for Preparing Paint Films". Tensile strength and elongation at break test methods: according to GB / T 528-2009. Coating adhesion test method: according to GB / T 9286-1998 "Cross-cut Test for Paint and Varnish Films" (cross-cut method). Coating hardness test method: according to GB / T 6739-1996 "Peking Pencil Test for Coating Hardness". Cold surface temperature measurement: A back-temperature tester was used. The heating platform temperature of the back-temperature tester was 800℃. Each sample was placed on the heating platform of the back-temperature tester, with the other side attached to a temperature sensor wire. The test lasted for 15 minutes, with a pressure of 27N, and the cold surface temperature was recorded. *Flame retardancy rating was determined according to UL94 standard.

[0073] Table 1. Formulations of silicone coatings in Examples 1-7

[0074] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Component A A1 A2 A3 A4 A5 A6 A7 Component B B1 B1 B1 B1 B1 B1 B1

[0075] Table 2. Formulations of silicone coatings for Comparative Examples 1-8

[0076]

[0077] Table 3 Performance test results of ceramicizable silicone elastomer coatings in Examples 1-7

[0078]

[0079] Table 4. High-temperature resistance test results (350℃, 24h) of the ceramicizable silicone elastomer coatings in Examples 1-7.

[0080]

[0081] Table 5. High-temperature resistance test results (350℃, 168h) of the ceramicizable silicone elastomer coatings in Examples 1-7.

[0082]

[0083] Table 6 shows the performance test results of the silicone elastomer coatings in Comparative Examples 1-8.

[0084]

[0085]

[0086] Table 7. High-temperature resistance test results of silicone elastomer coatings in Comparative Examples 1-8 (350℃, 24h)

[0087]

[0088] Table 8. High-temperature resistance test results of silicone elastomer coatings in Comparative Examples 1-8 (350℃, 168h)

[0089]

[0090] The silicone coating of this invention has low viscosity, making it easy to apply. Furthermore, the resulting ceramizable silicone elastomer coating exhibits high mechanical strength (tensile strength of 5-6 MPa) and excellent heat resistance. More importantly, the elastomer coating can withstand continuous high temperatures of 350°C for over 168 hours with excellent performance. In addition, after continuous firing at 1300°C for approximately 30 minutes, the elastomer coating rapidly forms a hard ceramizable shell during the ablation process, and no obvious burn-through marks are observed after firing. Its flame-retardant and fire-resistant properties are also excellent.

[0091] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0092] All aspects, embodiments, features, and examples of this invention are to be regarded as illustrative in all respects and are not intended to limit the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0093] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. An organosilicon coating, characterized in that, Includes component A and component B; Component A comprises the following components in parts by weight: 10-30 parts methyl vinyl silicone oil, 5-30 parts methyl vinyl phenyl silicone oil, 16-50 parts first organic solvent, 5-20 parts fumed silica, 0-1 parts MoS2 / MXene micro / nano heterostructure powder, 2-10 parts cerium oxide, 2-10 parts polytetrafluoroethylene micro powder, 0.3-1.5 parts perfluoropolyether, and 2-10 parts heat resistant agent; Component B includes a high-temperature oxidant, which is selected from one or more combinations of benzoyl peroxide and tert-butyl peroxide. The methyl vinylphenyl silicone oil contains 15-45 mol% phenyl and 5-15 mol% vinyl groups, respectively, and has the following structural formula: ； The MoS2 / MXene micro / nano heterostructure powder has hydroxyl groups and the amount used is not zero.

2. The organosilicon coating according to claim 1, characterized in that, The preparation method of the MoS2 / MXene micro / nano heterostructure powder includes: subjecting a mixed reaction system containing a sulfur source, a molybdenum source, a reducing agent and MXene powder to a hydrothermal reaction at 100-140℃ for 18-24h to obtain MoS2 / MXene micro / nano heterostructure powder, wherein the molar ratio of sulfur source, molybdenum source and reducing agent is 50-150:10-30:1-5, and the molar ratio of molybdenum source to MXene powder is 10-30 mmol:1.3g.

3. The organosilicon coating according to claim 2, characterized in that: The sulfur source is selected from thiourea, methiopyrimidine, or propylthiopyrimidine.

4. The organosilicon coating according to claim 2, characterized in that: The molybdenum source is selected from soluble molybdates.

5. The organosilicon coating according to claim 2, characterized in that: The reducing agent is selected from citric acid, malic acid, or dicopper histidine.

6. The organosilicon coating according to claim 1, characterized in that: The first organic solvent is selected from one or more combinations of n-heptane, cyclohexane, and petroleum ether.

7. The organosilicon coating according to claim 6, characterized in that: The first organic solvent comprises 10-30 parts by weight of n-heptane, 5-15 parts by weight of cyclohexane, and 1-5 parts by weight of petroleum ether.

8. The organosilicon coating according to claim 1, characterized in that: The high-temperature oxidant comprises 2-5 parts by mass of benzoyl peroxide and 1-3 parts by mass of tert-butyl peroxide, and component B further comprises 92-97 parts by mass of a second organic solvent.

9. The organosilicon coating according to claim 1, characterized in that: The heat-resistant agent includes one or more of titanium diboride and hollow glass microspheres.

10. A ceramicizable organosilicon elastomer coating, characterized in that: The coating is formed from the silicone coating according to any one of claims 1-9.

11. A method for preparing the ceramizable organosilicon elastomer coating of claim 10, characterized in that, include: A mixed reaction system containing a sulfur source, a molybdenum source, a reducing agent, and MXene powder was subjected to hydrothermal reaction at 100-140℃ for 18-24 h to obtain MoS2 / MXene micro / nano heterostructure powder. The molar ratio of sulfur source, molybdenum source, and reducing agent was 50-150:10-30:1-5, and the molar ratio of molybdenum source to MXene powder was 10-30 mmol:1.3 g. Component A is obtained by uniformly mixing methyl vinyl silicone oil, methyl vinyl phenyl silicone oil, a first organic solvent, fumed silica, MoS2 / MXene micro / nano heterostructure powder, cerium oxide, polytetrafluoroethylene micro powder, perfluoropolyether and heat resistant agent. Component B was prepared using a high-temperature oxidant; After uniformly mixing components A and B, the mixture is coated onto a substrate and heated at 80-120℃ for 2-6 hours, then left at room temperature for more than 7 days to obtain the ceramicizable organosilicon elastomer coating.

12. The method according to claim 11, characterized in that, Specifically, it includes: After all the ingredients used to form component A are uniformly mixed and ground, the mixture is then passed through a 100-150 mesh sieve to obtain component A.

13. A high-temperature resistant protective structure, characterized in that, Including the ceramicizable organosilicon elastomer coating as described in claim 10.

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