High temperature resistant silicone-modified coating and method of making

Abstract

The application discloses a high-temperature-resistant organic silicon modified coating and a preparation method, and relates to the technical field of anticorrosive coatings.The high-temperature-resistant organic silicon modified coating and the preparation method have the advantages that the heat-resistant stability and the interfacial bonding strength of a resin system are optimized by adopting a specific proportion of modified organic silicon resin and fillers, the coating failure problem under a high-temperature and corrosion environment is effectively solved, the high-temperature-resistant organic silicon modified coating has excellent high-temperature-resistant performance and corrosion resistance, can effectively resist a 500 DEG C high temperature and a marine corrosion environment, prevents the coating from cracking and the adhesion from decreasing, and prolongs the service life of a ship pipeline.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coatings technology, and in particular to a high-temperature resistant organosilicon-modified coating and its preparation method. Background Technology

[0002] Ship piping systems are the channels for transporting and discharging gas and liquid substances. Among them, thermal piping systems operate in the harshest environments, primarily including superheated steam pipes, saturated steam pipes, hot exhaust gas pipes, hot exhaust liquid pipes, and high and low pressure drainage pipes. Due to their long-term operation in high-temperature and gas-liquid environments, with some locations reaching temperatures up to 500°C, thermal piping systems are consistently among the most severely corroded parts of ships. Parts such as diesel engine exhaust pipes and steam pipes are particularly vulnerable to corrosion due to high temperatures and exposure to seawater, rainwater, and the marine atmosphere. Damage to high-temperature exhaust pipes can lead to exhaust gas leaks, affecting normal ship operation, or even serious accidents caused by seawater backflowing into the main engine from the cooling water jacket. Therefore, the high-temperature resistance and corrosion resistance of ship piping materials are crucial to ship safety and service life. The development of high-temperature resistant coatings for ships has significant application value in marine engineering and naval vessels, effectively protecting ships from the effects of high temperatures and corrosion, and extending their service life. Summary of the Invention

[0003] The main objective of this invention is to develop a high-temperature resistant coating specifically for ocean-going vessels, which can effectively protect the vessels from the effects of harsh environments such as high temperatures and corrosion, and extend the service life of the vessels.

[0004] To achieve the above objectives, the present invention proposes a high-temperature resistant organosilicon modified coating, wherein the raw materials of the high-temperature resistant organosilicon modified coating include 30wt%~60wt% of modified organosilicon resin and the balance filler; wherein the raw materials of the modified organosilicon resin include epoxy modified organosilicon resin, high-phenyl organosilicon resin, silaneyne resin solution, alkoxysilane and hydroxyl silicone oil.

[0005] In one embodiment, the epoxy equivalent of the epoxy-modified silicone resin is 500 g eq. -1 ~600g eq -1 .

[0006] In one embodiment, the ratio of phenyl to methyl groups in the high-phenyl organosilicon resin is 1.2 to 1.5.

[0007] In one embodiment, the silaneyne resin solution is obtained by dissolving silaneyne resin in xylene; wherein the solid content of the silaneyne resin solution is 50% to 70%.

[0008] In one embodiment, the alkoxysilane includes dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethoxyethylsilane, triethoxyethylsilane, trimethoxypropylsilane, triethoxypropylsilane, trimethoxyhexylsilane, triethoxyhexylsilane, trimethoxydecylsilane, triethoxydecylsilane, phenyltrimethoxysilane, γ-aminopropyltriethoxysilane, and 3... - At least one of glycidyl etheroxypropyltrimethoxysilane, 3-glycidyl etheroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, tetramethoxysilane, and tetraethoxysilane.

[0009] In one embodiment, the alkoxysilane further includes any one of octa(diethylenetriaminopropyl)cage polysilsesquioxane, octa(triethylenetetraaminopropyl)cage polysilsesquioxane, and octa(tetraethylenepentaminopropyl)cage polysilsesquioxane.

[0010] In one embodiment, the hydroxyl silicone oil is a modified hydroxyl silicone oil; the modified hydroxyl silicone oil is a double-terminated hydroxypropyl silicone oil.

[0011] In one embodiment, the modified organosilicon resin comprises the following raw materials in parts by weight: epoxy modified organosilicon resin: 6 to 15 parts; high-phenyl organosilicon resin: 20 to 40 parts; silaneyne resin solution: 10 to 20 parts; long-chain polysiloxane: 20 to 30 parts; alkoxysilane: 5 to 10 parts; hydroxyl silicone oil: 0.5 to 3 parts; catalyst: 0.5 to 1 part.

[0012] In one embodiment, the method for preparing the modified organosilicon resin includes the following steps: S1. The high-phenyl organosilicon resin, the silaneyne resin solution and the long-chain polysiloxane are mixed and heated to 100℃~120℃ under platinum catalyst, and reacted with stirring for 2h~6h to obtain the first intermediate. S2. Mix and stir the epoxy-modified silicone resin, the alkoxysilane, the hydroxyl silicone oil, and the first intermediate obtained in step S1. Add the catalyst and carry out a pre-hydrolysis reaction while stirring for 30 min to 60 min to obtain the second intermediate. Then, heat the second intermediate to 140℃ to 150℃ and react it under reflux for 2 h to 4 h to complete the preparation of the silicone resin.

[0013] In one embodiment, the filler comprises reinforcing filler and pigment filler in a weight ratio of (2~4):(5~10); wherein the reinforcing filler comprises at least one of silicon nitride powder, zirconium boride powder, low melting point glass powder, cerium oxide powder, glass flake powder, alumina powder, zirconium oxide powder, zirconium phosphate powder, boron nitride powder, and chromium oxide powder; and / or the pigment filler comprises at least one of titanium dioxide, titanium yellow powder, wollastonite, copper chromium black, titanium chromium brown, and iron oxide red powder.

[0014] This invention also proposes a method for preparing the aforementioned high-temperature resistant organosilicon-modified coating, comprising the following steps: The modified silicone resin and the filler are mixed, ground, and stirred according to the specified ratio to complete the preparation of the high-temperature resistant silicone modified coating.

[0015] This invention provides a high-temperature resistant organosilicon modified coating and its preparation method. By using a specific ratio of modified organosilicon resin and filler combination, the heat resistance stability and interfacial bonding strength of the resin system are optimized, effectively solving the coating failure problem under high temperature and corrosive environments. It has excellent high temperature resistance and corrosion resistance, can effectively resist high temperature of 500℃ and marine corrosive environment, prevent coating cracking and adhesion reduction, and extend the service life of ship piping system. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0018] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0019] The technical problem addressed in this application is as follows: Ship piping systems are the channels for transporting and discharging gas and liquids. Among them, thermal piping systems are located in the harshest environments, mainly including superheated steam pipes, saturated steam pipes, hot exhaust gas pipes, hot exhaust liquid pipes, and high and low pressure drainage pipes. Due to long-term operation in high-temperature and gas-liquid environments, with temperatures in some locations reaching up to 500°C, thermal piping systems have always been among the most severely corroded parts of ships. Parts such as diesel engine exhaust pipes and steam pipes are particularly vulnerable to corrosion due to high temperatures and exposure to seawater, rainwater, and the marine atmosphere. Corrosion and damage to high-temperature exhaust pipes can lead to exhaust gas leakage, affecting normal ship operation, or even, in severe cases, seawater from the cooling water jacket flowing back into the main engine, causing a major accident. Therefore, the high-temperature resistance and corrosion resistance of ship piping materials are crucial to ship safety and service life. The development of high-temperature resistant coatings for ships has significant application value in marine engineering and naval vessels, effectively protecting ships from the effects of high temperatures and corrosion, and extending their service life.

[0020] To address the aforementioned technical problems, this invention proposes a high-temperature resistant organosilicon modified coating. By combining a specific ratio of modified organosilicon resin and fillers, and leveraging the synergistic effect of various raw materials within the modified organosilicon resin, it effectively meets the protection requirements of ship thermal piping systems in high-temperature and corrosive environments.

[0021] Specifically, the 30wt%~60wt% modified silicone resin ratio ensures that the coating forms a continuous and stable silicone matrix, providing basic high-temperature resistance while maintaining appropriate flexibility to accommodate the thermal expansion and contraction of the piping system. The remaining filler serves as an auxiliary component, constructing a physical barrier layer to enhance the coating's mechanical strength and impermeability, effectively isolating it from corrosive media such as seawater and rainwater.

[0022] Furthermore, in the raw materials of modified silicone resins, epoxy-modified silicone resins enhance adhesion and chemical stability to metal substrates through epoxy groups, preventing corrosive media from penetrating from the interface; high-phenyl silicone resins utilize the high thermal stability of phenyl groups to strengthen the resin's antioxidant capacity in high-temperature environments and reduce thermal degradation; silanyne resin solutions introduce arylylene structures to further optimize structural integrity at high temperatures and extend the service life of coatings under harsh conditions; alkoxysilanes, as crosslinking agents, promote intermolecular crosslinking reactions, forming a dense network structure and improving overall corrosion resistance and mechanical strength; hydroxyl silicone oils improve the leveling and flexibility of coatings, ensuring uniform application and preventing cracking at high temperatures.

[0023] Through the synergistic effect of these characteristics, modified silicone resin, as the core component, achieves a balance between high temperature resistance and corrosion resistance through the synergistic effect of its internal raw materials; and ensures an optimized combination of matrix and filler in a specific ratio to jointly construct a multi-layered protection system, thereby providing long-lasting protection in high temperature and corrosive environments.

[0024] This application further specifies that the epoxy equivalent of the epoxy-modified silicone resin is 500 g eq. -1 ~600g eq -1 ; and / or, the ratio of phenyl to methyl groups in high-phenyl silicone resins is 1.2 to 1.5.

[0025] Specifically, epoxy equivalent refers to the percentage by mass of epoxy groups in the total amount of epoxy-modified silicone resin, which can be achieved by adjusting the raw material ratio or reaction conditions. For example, the feeding ratio of bisphenol A type epoxy resin to silicone intermediates can be controlled during the synthesis process, or the epoxy equivalent in the final product can be adjusted by changing the reaction temperature and time. The purpose of introducing this feature is to ensure that the coating forms a network structure with a suitable crosslinking density at high temperatures, thereby balancing the mechanical properties and thermal stability of the coating.

[0026] The ratio of phenyl to methyl groups refers to the molar relationship between phenyl and methyl groups in the molecular chain of a high-phenyl silicone resin. This ratio can be achieved by selecting siloxane monomers with different phenyl contents or adjusting the copolymerization ratio. For example, by using different ratios of phenyltrimethoxysilane and dimethyldimethoxysilane in a hydrolysis-condensation reaction, resin products with a specific phenyl-methyl ratio can be obtained. This feature aims to optimize the rigidity and flexibility of the resin molecules, ensuring sufficient heat resistance at high temperatures without causing brittleness due to excessive rigidity.

[0027] This application further proposes that the silaneyne resin solution is obtained by dissolving silaneyne resin in xylene; wherein the solid content of the silaneyne resin solution is 50% to 70%.

[0028] Specifically, a silanyne resin solution refers to a homogeneous solution formed by dissolving silanyne resin in xylene solvent. In practical applications, xylene is chosen as the solvent based on its polarity matching characteristics with organosilicon molecules, which effectively avoids impurities or compatibility defects that may be introduced by other solvents, thereby ensuring the uniform dispersion and chemical stability of the resin in the solution. Furthermore, the solid content is strictly limited to 50%–70%, based on in-depth consideration of the solution rheological behavior. This maintains a suitable viscosity to ensure sufficient filler dispersion and workability, while also ensuring sufficient resin loading to form a dense and continuous protective film.

[0029] This application further proposes alkoxysilanes including dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethoxyethylsilane, triethoxyethylsilane, trimethoxypropylsilane, triethoxypropylsilane, trimethoxyhexylsilane, triethoxyhexylsilane, trimethoxydecylsilane, triethoxydecylsilane, phenyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-glycidyletheroxypropyltrimethoxysilane, 3-glycidyletheroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3- At least one of aminopropylmethyldiethoxysilane, tetramethoxysilane, and tetraethoxysilane.

[0030] Specifically, alkoxysilanes refer to organosilicon compounds with specific chemical structures, which can be achieved using the specific compounds listed above. The selection of these compounds aims to address the problem of insufficient stability during high-temperature crosslinking through their specific chemical structures and reactivity characteristics.

[0031] Specifically, the above solution ensures that the cross-linked network is uniform and dense in the extreme environment of the ship's thermal piping system by synergistically selecting multiple types of silanes, effectively inhibiting the penetration of high-temperature corrosive media and maintaining the long-term protective function of the coating.

[0032] This application further proposes that the alkoxysilane in the above-mentioned high-temperature resistant organosilicon modified coatings also includes any one of octa(diethylenetriaminopropyl)cage polysilsesquioxane, octa(triethylenetetraaminopropyl)cage polysilsesquioxane, and octa(tetraethylenepentaaminopropyl)cage polysilsesquioxane.

[0033] Specifically, octa(diethylenetriaminopropyl)cage-type polysilsesquioxane refers to a compound with a rigid three-dimensional cage-like framework structure. Its surface is modified with polyamino groups, enabling deep cross-linking reactions with the epoxy and hydroxyl groups in modified organosilicon resins. In practical applications, this compound can be prepared via the sol-gel method, aiming to provide a basis for thermodynamic stability and enhance the coating's crack resistance. The introduction of these specifically amino-functionalized cage-type polysilsesquioxanes significantly improves the structural stability of the coating at high temperatures. The rigid three-dimensional cage-like framework of the cage-type polysilsesquioxane effectively inhibits the thermal motion of molecular chains at high temperatures, thereby preventing thermal degradation. Simultaneously, the surface-modified polyamino groups form a dense and uniform network structure with the modified organosilicon resin, not only strengthening the interfacial bonding between the resin and filler but also improving the overall crack resistance of the coating.

[0034] This application further specifies that in the aforementioned high-temperature resistant organosilicon modified coatings, the hydroxyl silicone oil is a modified hydroxyl silicone oil; specifically, the modified hydroxyl silicone oil is a double-terminated hydroxypropyl silicone oil. Specifically, the modified hydroxyl silicone oil refers to a hydroxyl silicone oil with specific functions obtained through chemical modification or structural optimization, which can be achieved by introducing functional groups at the ends of the molecular chain, block copolymerization in the main chain, etc. The purpose is to improve the stability of the hydroxyl silicone oil under high-temperature conditions and avoid the degradation of coating performance due to thermal decomposition.

[0035] This application further proposes that the modified organosilicon resin comprises the following raw materials in parts by weight: epoxy modified organosilicon resin: 6 to 15 parts; high-phenyl organosilicon resin: 20 to 40 parts; silaneyne resin solution: 10 to 20 parts; long-chain polysiloxane: 20 to 30 parts; alkoxysilane: 5 to 10 parts; hydroxyl silicone oil: 0.5 to 3 parts; catalyst: 0.5 to 1 part.

[0036] Among them, epoxy-modified silicone resin refers to silicone resin containing epoxy groups. It can be achieved by modifying silicone resin with bisphenol A type epoxy resin or aliphatic epoxy resin, with the aim of providing core crosslinking sites to ensure the interfacial bonding strength between the coating and the substrate. High-phenyl silicone resin can be understood as silicone resin containing phenyl groups. Its heat resistance can be changed by adjusting the phenyl content, with the aim of building an inherent heat-resistant barrier to avoid carbonization and decomposition at high temperatures. Silaneyne resin solution refers to a solution formed by dissolving silicone resin containing alkynyl functional groups in a solvent. It can be prepared using silaneyne resins of different molecular weights, with the aim of strengthening the three-dimensional network structure and preventing accelerated thermo-oxidative aging. Long-chain polysiloxane refers to polymers with flexible silicon-oxygen segments, which can be achieved using polydimethylsiloxane with different chain lengths, with the aim of acting as stress-buffering units to adapt to thermal deformation.

[0037] Specifically, a multi-level synergistic molecular network structure was constructed. Within a specific ratio range, the epoxy groups of the epoxy-modified silicone resin act as core crosslinking sites, undergoing directional condensation reactions with alkoxysilanes to form a dense network. The high-phenyl silicone resin provides an inherent heat-resistant barrier through its rigid aromatic ring structure, ensuring the stability of the resin backbone at 500℃. The alkynyl groups in the silanarylkyne resin solution trigger self-crosslinking reactions at high temperatures, enhancing the continuity of the resin's three-dimensional network.

[0038] This application further proposes a method for preparing modified organosilicon resin, comprising the following steps: S1. Mix high-phenyl organosilicon resin, silaneyne resin solution and long-chain polysiloxane, and heat to 100℃~120℃ under platinum catalyst, and react with stirring for 2h~6h to obtain the first intermediate. S2. Mix and stir the epoxy-modified silicone resin, alkoxysilane, hydroxyl silicone oil and the first intermediate obtained in step S1, add the catalyst, and carry out a pre-hydrolysis reaction while stirring for 30 min to 60 min to obtain the second intermediate; then heat the second intermediate to 140℃ to 150℃ and react it under reflux for 2 h to 4 h to complete the preparation of the silicone resin.

[0039] Specifically, the first intermediate refers to the product generated by reacting high-phenyl silicone resin, silanylene resin solution, and long-chain polysiloxane under the action of a platinum catalyst within a specific temperature range. Full cross-linking can be achieved by controlling the reaction temperature and time, with the aim of forming a dense and stable transition product. The second intermediate refers to the product generated by introducing epoxy-modified silicone resin, alkoxysilane, and hydroxyl silicone oil into the first intermediate, followed by a pre-hydrolysis reaction. The uniform distribution of silanol groups can be ensured by adjusting the pre-hydrolysis time and reaction conditions, with the aim of providing a good reaction foundation for subsequent high-temperature condensation.

[0040] This application further proposes that the filler includes reinforcing filler and pigment filler in a weight ratio of 2~4:5~10; wherein the reinforcing filler includes at least one of silicon nitride powder, zirconium boride powder, low melting point glass powder, cerium oxide powder, glass flake powder, alumina powder, zirconium oxide powder, zirconium phosphate powder, boron nitride powder, and chromium oxide powder; and / or the pigment filler includes at least one of titanium dioxide, titanium yellow powder, wollastonite, copper chromium black, titanium chromium brown, and iron oxide red powder.

[0041] Specifically, fillers refer to functional material combinations used to enhance the mechanical strength and corrosion resistance of coatings. They can be achieved by mixing various inorganic powder materials in specific proportions, with the aim of optimizing the overall performance of the coating under high-temperature and corrosive environments. Reinforcing fillers can be materials with high hardness and chemical stability, such as silicon nitride powder, which can form a protective layer at high temperatures to resist thermal stress cracking. Pigments and fillers can be functional materials such as titanium dioxide, which can reduce the aging rate of the coating by reflecting heat radiation and provide good weather resistance and workability.

[0042] In another embodiment, this application also discloses a method for preparing a high-temperature resistant organosilicon modified coating, wherein modified organosilicon resin and filler are mixed, ground, and stirred according to a formula to complete the preparation of the high-temperature resistant organosilicon modified coating.

[0043] Modified silicone resins can be understood as composite material systems formed through the synergistic effect of various functional resins and additives. For example, epoxy-modified silicone resins can achieve modification effects by introducing bisphenol A type epoxy resins or aliphatic epoxy resins; the phenyl content in high-phenyl silicone resins can be optimized for thermal stability by adjusting the ratio of phenyl to methyl groups; silaneyne resin solutions can be prepared by dissolving resins containing arylylene structures in solvents such as toluene or xylene; the selection range of alkoxysilanes includes vinyltrimethoxysilane or acrylate-based triethoxysilane; and hydroxyl silicone oils can have their leveling and flexibility improved by adjusting the molecular chain length or introducing other polar groups. These characteristics collectively ensure the coating's antioxidant capacity and structural integrity under high-temperature environments.

[0044] The present invention will be further illustrated below through specific embodiments: The raw materials, reagents, or devices used in the embodiments of this invention are all commercially available. Unless otherwise specified, this invention does not impose any restrictions on the source of raw materials.

[0045] Example 1 The raw materials for the high-temperature resistant silicone-modified coating in Example 1 include 60 wt% modified silicone resin, 10 wt% zirconium phosphate powder (particle size approximately 10 μm to 50 μm), and 30 wt% iron oxide red powder (particle size approximately 30 μm to 100 μm). The raw materials for the modified silicone resin in Example 1 include: Epoxy modified silicone resin: 120g; High-phenyl silicone resin: 250g; Silaneyne resin solution: 150g; Vinyl-terminated long-chain polydimethylsiloxane: 250g; Methyltriethoxysilane: 50g; Octa(triethylenetetraaminopropyl) cage-type polysilsesquioxane: 15g; Bis-terminated hydroxypropyl silicone oil: 15g; Formic acid catalyst: 10g.

[0046] Among them, the epoxy-modified silicone resin was purchased from Hubei Xin Sihai, model SH-023-7; the high-phenyl silicone resin was purchased from Dow, model SR-240; and the molecular weight of the double-terminated hydroxypropyl silicone oil was approximately 2000 g mol. -1 The product was purchased from Guangzhou Guiyou, model number GT-9201; the silaneyne resin was purchased from the PSA series of East China University of Science and Technology.

[0047] The solid content of the silaneyne resin solution in Example 1 is about 50%.

[0048] The preparation method of the modified organosilicon resin in Example 1 includes the following steps: S1. Mix high-phenyl organosilicon resin, silaneyne resin solution and vinyl-terminated long-chain polydimethylsiloxane, add 5g of platinum catalyst, heat to 120℃, and carry out hydrosilylation under a protective atmosphere with stirring for 2h to obtain the first intermediate. S2. Mix and stir the epoxy-modified silicone resin, alkoxysilane, hydroxyl silicone oil and the first intermediate obtained in step S1. Add formic acid and carry out a pre-hydrolysis reaction at room temperature while stirring for 30 minutes to obtain the second intermediate. Then, slowly heat the second intermediate to 140℃~150℃ and react it under reflux for 2.5 hours to complete the preparation of the silicone resin.

[0049] The preparation method of the high-temperature resistant organosilicon modified coating in Example 1 includes the following steps: The modified silicone resin and filler are mixed according to the formula, ground through a 100-mesh sieve, and stirred for 30 minutes to complete the preparation of the high-temperature resistant silicone modified coating.

[0050] Comparative Example 1 Comparative Example 1 is based on Example 1, except that epoxy-modified silicone resin is not added to the raw materials of the modified silicone resin.

[0051] Comparative Example 2 Comparative Example 2 is based on Example 1, except that high-phenyl silicone resin is not added to the raw materials of the modified silicone resin.

[0052] Comparative Example 3 Comparative Example 3 is based on Example 1, except that no silaneyne resin solution is added to the raw materials of the modified organosilicon resin.

[0053] The high-temperature resistant silicone-modified coatings from Examples 1 and Comparative Examples 1-3 were electrostatically sprayed onto 1.0 mm thick rust-removed and degreased cold-rolled steel plates using a corona spray gun. The coatings were then baked at 180°C for 20 min, resulting in a coating thickness of 70 μm ± 3 μm. Performance tests were then conducted.

[0054] Performance testing: (1) Referring to GB / T 1735-2020 "Determination of Heat Resistance of Coating Film", Examples 1 and Comparative Examples 1-3 were placed in a muffle furnace and heated to 400℃, 500℃ and 600℃ continuously at a rate of 5℃ / min. After holding at this temperature for 10 hours, the coating condition was observed. The test results are shown in Table 1. (2) Cyclic thermal shock test: Example 1 and Comparative Examples 1-3 were repeatedly cyclically placed between room temperature and 600℃ (each cycle included: 30 min at room temperature → heating to 600℃ (rate 10℃ / min), holding for 1 h → cooling to room temperature with the furnace), and the cracking and peeling of the coating were observed and the number of cycles was recorded.

[0055] (3) Salt spray test (GB / T 1771-2007): Example 1 and Comparative Examples 1-3 were continuously sprayed in a 5% NaCl solution atomization environment for 500h, and the corrosion spread was observed.

[0056] Table 1

[0057] The results of the cyclic thermal shock test show that the high-temperature resistant coating of the present invention can withstand no less than 20 cycles from room temperature to 600°C without obvious cracks, while the coatings in Comparative Examples 1-3 all showed obvious cracks after less than 15 cycles.

[0058] The results of the salt spray test showed that the corrosion area of ​​the coating of the present invention was less than 0.1%, while the coatings in Comparative Examples 1-3 all showed pitting corrosion with a pore size of not less than 0.2 mm, and rust appeared due to the penetration of microcracks.

[0059] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A high-temperature resistant organosilicon-modified coating, characterized in that, The raw materials of the high-temperature resistant silicone modified coating include 30wt%~60wt% modified silicone resin, and the balance being filler; The raw materials for the modified organosilicon resin include epoxy-modified organosilicon resin, high-phenyl organosilicon resin, silaneyne resin solution, alkoxysilane, and hydroxyl silicone oil.

2. The high-temperature resistant organosilicon-modified coating as described in claim 1, characterized in that, The epoxy equivalent of the epoxy-modified silicone resin is 500 g eq. -1 ~600g eq -1 ; And / or, the ratio of phenyl to methyl groups in the high-phenyl organosilicon resin is 1.2 to 1.

5.

3. The high-temperature resistant organosilicon-modified coating as described in claim 1, characterized in that, The silaneyne resin solution is obtained by dissolving silaneyne resin in xylene; The solid content of the silaneyne resin solution is 50% to 70%.

4. The high-temperature resistant organosilicon-modified coating as described in claim 1, characterized in that, The alkoxysilanes include at least one of dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethoxyethylsilane, triethoxyethylsilane, trimethoxypropylsilane, triethoxypropylsilane, trimethoxyhexylsilane, triethoxyhexylsilane, trimethoxydecylsilane, triethoxydecylsilane, phenyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-glycidyletheroxypropyltrimethoxysilane, 3-glycidyletheroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, tetramethoxysilane, and tetraethoxysilane.

5. The high-temperature resistant organosilicon-modified coating as described in claim 4, characterized in that, The alkoxysilane further includes any one of octa(diethylenetriaminopropyl)cage polysilsesquioxane, octa(triethylenetetraaminopropyl)cage polysilsesquioxane, and octa(tetraethylenepentaminopropyl)cage polysilsesquioxane.

6. The high-temperature resistant organosilicon-modified coating as described in claim 1, characterized in that, The hydroxyl silicone oil is a modified hydroxyl silicone oil; The modified hydroxyl silicone oil is a double-terminated hydroxypropyl silicone oil.

7. The high-temperature resistant organosilicon-modified coating as described in claim 1, characterized in that, The modified silicone resin comprises the following raw materials in parts by weight: Modified silicone resin: 6 parts to 15 parts; High-phenyl silicone resin: 20-40 parts; Silaneyne resin solution: 10 to 20 parts; Long-chain polysiloxanes: 20 to 30 parts; Alkoxysilane: 5 to 10 parts; Hydroxy silicone oil; 0.5 to 3 parts; Catalyst: 0.5 to 1 part.

8. The high-temperature resistant organosilicon-modified coating as described in claim 7, characterized in that, The preparation method of the modified organosilicon resin includes the following steps: S1. The high-phenyl organosilicon resin, the silaneyne resin solution and the long-chain polysiloxane are mixed and heated to 100℃~120℃ under platinum catalyst, and reacted with stirring for 2h~6h to obtain the first intermediate. S2. Mix and stir the epoxy-modified silicone resin, the alkoxysilane, the hydroxyl silicone oil, and the first intermediate obtained in step S1. Add the catalyst and carry out a pre-hydrolysis reaction while stirring for 30 min to 60 min to obtain the second intermediate. Then, heat the second intermediate to 140℃ to 150℃ and react it under reflux for 2 h to 4 h to complete the preparation of the silicone resin.

9. The high-temperature resistant organosilicon-modified coating as described in claim 1, characterized in that, The filler comprises reinforcing filler and pigment filler in a weight ratio of (2~4):(5~10); The reinforcing filler includes at least one of silicon nitride powder, zirconium boride powder, low melting point glass powder, cerium oxide powder, glass flake powder, alumina powder, zirconium oxide powder, zirconium phosphate powder, boron nitride powder, and chromium oxide powder; and / or the pigments and fillers include at least one of titanium dioxide, titanium yellow powder, wollastonite, copper chromium black, titanium chromium brown, and iron oxide red powder.

10. A method for preparing a high-temperature resistant organosilicon-modified coating as described in any one of claims 1 to 9, characterized in that, The preparation method of the high-temperature resistant organosilicon modified coating includes the following steps: The modified silicone resin and the filler are mixed, ground, and stirred according to the specified ratio to complete the preparation of the high-temperature resistant silicone modified coating.

Images