A high temperature resistant industrial coating and a method of manufacturing the same

Abstract

The present application relates to a kind of high-temperature resistant industrial coating and its manufacturing method, belong to coating technical field, the present application is obtained after the reaction of phenyltrimethoxysilane, titanium acid tetraisopropyl ester, acetylacetone, tetramethyl tetraphenyl trisiloxane and temperature resistance modifier, with bisphenol A type epoxy resin and acetylacetone aluminum reaction modified matrix resin;Calcined kaolin, boro-modified mica powder and silicon carbide powder are activated to obtain activated filler by titanium acid ester coupling agent;The coating prepared by the cooperation of modified matrix resin, activated filler and other auxiliary ingredients is formed by the synergistic effect of multiple components and process optimization, and a high-temperature resistant, strong adhesive and corrosion-resistant composite coating system is formed, which can improve the high-temperature resistance while balancing other application performance.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a high-temperature resistant industrial coating and its manufacturing method. Background Technology

[0002] In the wave of rapid development of modern industry, various industrial equipment and facilities are facing increasingly severe high-temperature environments. From thermal power plants and nuclear power plants in the energy sector, to high-temperature reactors and pyrolysis furnaces in the chemical industry, and even aircraft engines in the aerospace industry, high-temperature conditions are ubiquitous. This makes high-temperature resistant industrial coatings a key material for ensuring stable equipment operation and extending service life.

[0003] Traditional ordinary coatings have many defects in high-temperature environments. When the temperature rises, the molecular structure of ordinary coatings changes, causing the coating to soften, blister, or even peel off. For example, when ordinary coatings are applied to the surface of some industrial boilers, the coating quickly powders under prolonged high-temperature baking, failing to provide effective protection for the boiler. This accelerates equipment corrosion and damage, increasing maintenance costs and safety hazards. In the aerospace field, when aircraft fly at high speeds, the intense friction between the aircraft surface and the air generates extremely high temperatures. Ordinary coatings simply cannot withstand such high-temperature impacts, let alone meet the requirements of lightweight, high-strength, and special functionalities of aircraft.

[0004] To address these challenges, high-temperature resistant industrial coatings have emerged. Early high-temperature resistant coatings primarily used silicone resins as a base, leveraging the high bond energy of the silicon-oxygen bond (Si-O) to provide a certain degree of thermal stability, capable of withstanding temperatures of 300-500℃. However, these coatings also had limitations, such as poor mechanical properties, inadequate adhesion, insufficient abrasion resistance, and low solvent resistance, making them unsuitable for applications requiring high overall performance. With technological advancements, a series of heterocyclic polymers have been applied to high-temperature resistant coatings. These polymers possess excellent heat resistance, radiation resistance, oil resistance, hydrolysis resistance, and abrasion resistance, effectively improving coating performance. For example, polyimide, as a high-performance heterocyclic polymer, is widely used in high-temperature resistant coatings in the aerospace field. It can withstand temperatures exceeding 500℃ and possesses good mechanical and electrical insulation properties, meeting the requirements of critical components such as aircraft engines operating in extreme high-temperature environments.

[0005] In recent years, the development of nanotechnology has brought new breakthroughs to high-temperature resistant industrial coatings. By introducing nanomaterials (such as nano-oxides and carbon nanotubes) into coating systems, the performance of coatings can be significantly improved. Nanomaterials have characteristics such as high specific surface area, small size effect, and quantum size effect, which can enhance the adhesion, hardness, wear resistance, and high-temperature resistance of coatings.

[0006] Despite significant advancements in high-temperature resistant industrial coatings, continuous development and improvement of next-generation high-temperature resistant coatings are still necessary to better serve industrial development and extend protective lifespan in the face of ever-increasing industrial demands. Summary of the Invention

[0007] To further improve the protective performance of coatings, enhance high-temperature resistance, and balance other application properties (including high humidity resistance and corrosion resistance), this invention provides a high-temperature resistant industrial coating and its manufacturing method. The method involves reacting phenyltrimethoxysilane, tetraisopropyl titanate, acetylacetone, tetramethyltetraphenyltrisiloxane, and a temperature-resistant modifier with bisphenol A type epoxy resin and aluminum acetylacetone to obtain a modified matrix resin. Calcined kaolin, boron-modified mica powder, and silicon carbide powder are activated with a titanate coupling agent to obtain an activated filler. The coating, prepared by combining the modified matrix resin, activated filler, and other additives, achieves a high-temperature resistant, highly adhesive, and corrosion-resistant composite coating system through multi-component synergistic effects and process optimization. This system effectively balances other application properties while improving high-temperature resistance. The specific technical solution is as follows:

[0008] A high-temperature resistant industrial coating comprises the following raw materials in parts by weight: 100-110 parts phenyltrimethoxysilane, 30-35 parts tetraisopropyl titanate, 0.4-0.6 parts acetylacetone, 10-12 parts tetramethyltetraphenyltripolysiloxane, 20-25 parts heat-resistant modifier, 65-70 parts bisphenol A epoxy resin, 2-3 parts aluminum acetylacetone, 1-2 parts titanate coupling agent, 40-42 parts calcined kaolin, 25-28 parts boron-modified mica powder, 4-6 parts silicon carbide powder, and 0.2-0.3 parts BY. K-163 dispersant and 0.8 to 1.0 parts of polyether-modified siloxane, with propylene glycol methyl ether acetate as solvent; the phenyltrimethoxysilane, tetraisopropyl titanate, acetylacetone, tetramethyltetraphenyltripolysiloxane and heat-resistant modifier are reacted, and then reacted with bisphenol A type epoxy resin and aluminum acetylacetone to obtain a modified matrix resin; the heat-resistant modifier is hydroxyl-terminated methyl-3,3,3-trifluoropropylsiloxane and polysiloxane; the calcined kaolin, boron-modified mica powder and silicon carbide powder are activated by titanate coupling agent to obtain activated filler.

[0009] The preparation method of the modified matrix resin in the above coating includes: mixing 100-110 parts of phenyltrimethoxysilane and 150-180 parts of deionized water to obtain solution A; mixing 30-35 parts of tetraisopropyl titanate, 0.4-0.6 parts of acetylacetone and 20-25 parts of propylene glycol methyl ether acetate to obtain solution B; and mixing 10-12 parts of tetramethyltetraphenyltripolysiloxane, 20-25 parts of a heat-resistant modifier and 70-80 parts of propylene glycol methyl ether acetate to obtain solution B. Alcohol methyl ether acetate was mixed to obtain solution C; 65-70 parts of bisphenol A type epoxy resin and 2-3 parts of aluminum acetylacetonate were mixed to obtain solution D; under nitrogen protection, solutions A, B and C were mixed and stirred at 60-65°C, cooled to room temperature, and then solution D was added dropwise with stirring while controlling the system temperature below 80°C. After the addition was complete, the temperature was raised to 120-125°C and stirred to react. The water was removed by vacuum distillation to obtain the modified matrix resin.

[0010] In the above-mentioned method for preparing the modified matrix resin, the stirring speed is 300 rpm to 400 rpm; the stirring reaction time is 1.5 h to 2 h; the dropping time is 40 min to 50 min; the heating rate is 1 °C / min to 1.5 °C / min; and the vacuum distillation is stopped when the water distillate is <5 mL / h.

[0011] The preparation method of the activated filler in the above coating includes: mixing 1 to 2 parts of titanate coupling agent, 0.1 to 0.12 parts of acetic acid and 6 to 8 parts of anhydrous ethanol to obtain an activator; mixing 40 to 42 parts of calcined kaolin, 25 to 28 parts of boron-modified mica powder and 4 to 6 parts of silicon carbide powder, spraying the activator in while stirring, stirring and mixing; drying, and sieving to obtain the activated filler.

[0012] In the above-mentioned method for preparing activated filler, the stirring speed is 1500 rpm to 2000 rpm; the stirring and mixing time is 40 min to 50 min; the drying is carried out at 80℃ to 85℃ until constant weight; and the sieving is carried out through a 200-250 mesh sieve.

[0013] In the above coating, the calcined kaolin is sieved through a 1250-mesh sieve; the boron-modified mica powder has a particle size D90 < 10 μm; and the silicon carbide powder has a particle size D90 < 10 μm.

[0014] The preparation method of the boron-modified mica powder in the above coating includes: dispersing mica powder in deionized water according to the mass ratio of mica powder:boric acid = 100:(8-12) to obtain a mica powder dispersion; dissolving boric acid in warm water to obtain a boric acid solution; adding the boric acid solution dropwise into the mica powder dispersion under stirring, heating to 80℃-85℃, and stirring for 1.5h-2h; spray drying to obtain a composite powder, sintering, and cooling to obtain boron-modified mica powder.

[0015] In the above method for preparing boron-modified mica powder, the amount of deionized water used is 4 to 6 times the mass of the mica powder; the dispersion is performed by shear dispersion at 4000 r / min to 5000 r / min for 30 min to 40 min; the temperature of the warm water is 55℃ to 60℃, and the amount of warm water used is 3 to 5 times the mass of boric acid; the stirring speed is 300 rpm to 400 rpm; the sintering parameters are: heating to 300℃ to 350℃, holding for 30 min to 40 min, continuing to heat to 500℃ to 550℃, and holding for 2 h to 3 h; the average heating rate is 2℃ / min to 3℃ / min.

[0016] The above-mentioned method for manufacturing a high-temperature resistant industrial coating includes the following steps: at a temperature below 35°C, adding BYK-163 dispersant, polyether-modified siloxane, and propylene glycol methyl ether acetate to a modified matrix resin, stirring, then adding activated filler, intermittently grinding, and vacuum defoaming to obtain the coating.

[0017] In the above manufacturing method, the stirring is carried out at 200 rpm to 300 rpm for 15 min to 20 min; the intermittent grinding is carried out at 1800 rpm to 2000 rpm until the fineness is ≤20 μm; and the temperature of the intermittent grinding is controlled below 35℃.

[0018] The present invention provides a high-temperature resistant industrial coating and its manufacturing method, which have the following beneficial effects:

[0019] I. Synergistic Construction of High-Temperature Resistance: Phenyltrimethoxysilane and tetramethyltetraphenyltrisiloxane form a thermally stable network through Si-O-Si bonds. The fluorosilicone segments in the temperature-resistant modifier further enhance the thermal stability of the molecular chain, enabling the coating to maintain structural integrity at high temperatures. The crosslinking reaction between bisphenol A epoxy resin and aluminum acetylacetonate enhances the network density, preventing molecular chain breakage at high temperatures.

[0020] II. Enhancement of Mechanical Properties and Adhesion: Fillers such as calcined kaolin and boron-modified mica powder activated by titanate coupling agents combine with the resin matrix through chemical bonds to form a "rigid skeleton," thereby improving the coating's hardness and impact resistance. At the same time, the epoxy groups in the modified matrix resin form a chemical anchor with the substrate, resulting in better adhesion.

[0021] III. Multiple Constructions of Corrosion-Resistant Barriers: The layered structure of boron-modified mica powder can physically block the penetration of salt spray and acid / alkali media. Its surface borate glass phase melts and seals pores at high temperatures, further isolating corrosive media. The low surface energy characteristics of fluorosilicone segments reduce media adsorption, and together with the dense resin network, effectively improve corrosion resistance.

[0022] IV. Multiple Contributions from the Matrix Resin Components: The hydrolysis and condensation of phenyltrimethoxysilane forms a Si-O-Si backbone with bond energies higher than ordinary C-C bonds, making it less prone to breakage at high temperatures and providing basic thermal stability for the coating. After crosslinking with tetraisopropyl titanate, it forms an interpenetrating network, enhancing mechanical strength. Tetramethyltetraphenyltrisiloxane introduces phenyl side chains, increasing steric hindrance of the molecular chain and inhibiting chain segment movement at high temperatures. An addition of 10-12 parts results in the optimal Si-O-Si network density; excessive amounts lead to phase separation. The hydroxyl-terminated fluorosilicone segments of the heat-resistant modifier are incorporated into the resin network through a condensation reaction. The electronegativity of the fluorine atoms forms an "electron barrier," preventing the intrusion of oxygen free radicals and simultaneously reducing the surface energy of the coating, thus improving solvent resistance. Insufficient addition leads to a decrease in the thermal decomposition temperature of the coating. The epoxy groups of bisphenol A type epoxy resin react with the hydroxyl groups generated from the hydrolysis of siloxane to form a "siloxane-epoxy" hybrid structure, combining the toughness of epoxy resin with the high-temperature resistance of siloxane.

[0023] V. Role of Fillers and Additives: Boron-modified mica powder forms a borosilicate glass phase through boric acid sintering. This phase melts and fills the pores of the coating at high temperatures, extending the penetration path of corrosive media. Unmodified mica powder, lacking the borosilicate phase, has a shorter salt spray resistance time. The alkoxy groups in the titanate coupling agent react with the hydroxyl groups on the surface of the filler (kaolin, silicon carbide), causing the long organic chains to entangle with the resin matrix, forming a "filler-coupling agent-resin" chemical bridge. This improves filler dispersibility and prevents stress concentration. BYK-163 dispersant adsorbs onto the filler surface through anchoring groups, forming steric hindrance to prevent agglomeration and dispersing the filler in the resin, thus improving coating uniformity.

[0024] VI. Mechanism of Action of Special Process Steps on Performance: In the preparation of modified matrix resin, stepwise temperature control of the reaction is employed. First, silane is hydrolyzed at 60℃~65℃ to form a prepolymer, then the temperature is raised to 120℃~125℃ to promote cross-linking of epoxy and siloxane. Omitting the intermediate cooling step will lead to phase separation and a decrease in the temperature resistance limit. Vacuum distillation is used to remove water, controlling the water distillate to <5mL / h to prevent residual water from vaporizing and forming bubbles at high temperatures, which would affect the coating's density. High-temperature sintering of boron-modified mica powder involves stepwise sintering to allow boric acid to react with the hydroxyl groups on the mica surface to form boron-oxygen bonds, improving compatibility with the resin. Detailed Implementation

[0025] The present invention will be further described below with reference to specific implementation examples, but the present invention is not limited to these embodiments.

[0026] Example 1

[0027] A high-temperature resistant industrial coating comprises the following raw materials in parts by weight: 100 parts phenyltrimethoxysilane, 30 parts tetraisopropyl titanate, 0.4 parts acetylacetone, 10 parts tetramethyltetraphenyltripolysiloxane, 20 parts heat-resistant modifier, 65 parts bisphenol A type epoxy resin, 2 parts aluminum acetylacetonate, 1 part titanate coupling agent, 40 parts calcined kaolin, 25 parts boron-modified mica powder, 4 parts silicon carbide powder, 0.2 parts BYK-163 dispersant, and 0.8 parts polyether-modified siloxane; the solvent is propylene glycol methyl ether acetate. The heat-resistant modifier is hydroxyl-terminated methyl-3,3,3-trifluoropropylsiloxane and polysiloxane; the calcined kaolin is sieved through a 1250-mesh sieve; the boron-modified mica powder has a particle size D90 of 6 μm; and the silicon carbide powder has a particle size D90 of 8 μm.

[0028] The preparation method of the modified matrix resin includes: mixing 100 parts of phenyltrimethoxysilane and 150 parts of deionized water to obtain solution A; mixing 30 parts of tetraisopropyl titanate, 0.4 parts of acetylacetone and 20 parts of propylene glycol methyl ether acetate to obtain solution B; mixing 10 parts of tetramethyltetraphenyltrisiloxane, 20 parts of heat-resistant modifier and 70 parts of propylene glycol methyl ether acetate to obtain solution C; and mixing 65 parts of bisphenol A type epoxy resin and 2 parts of aluminum acetylacetonate to obtain solution D. Under nitrogen protection, solutions A, B, and C were mixed and stirred at 60°C and 300 rpm for 1.5 h. The mixture was then cooled to room temperature, and solution D was added dropwise over 40 min while stirring at 300 rpm, with the system temperature controlled below 80°C. After the addition was complete, the temperature was increased to 120°C at a rate of 1°C / min and stirred at 300 rpm for 1.5 h. The water was removed by vacuum distillation until the water distillate flow rate reached 4.2 mL / h, yielding the modified matrix resin.

[0029] The preparation method of the activated filler includes: mixing 1 part titanate coupling agent, 0.1 part acetic acid and 6 parts anhydrous ethanol to obtain an activator; mixing 40 parts calcined kaolin, 25 parts boron-modified mica powder and 4 parts silicon carbide powder, spraying the activator into the mixture while stirring at 1500 rpm, stirring and mixing at 1500 rpm for 40 min; drying at 80℃ to constant weight, and passing through a 200-mesh sieve to obtain the activated filler.

[0030] The preparation method of boron-modified mica powder includes: dispersing mica powder in 4 times its mass of deionized water according to the mass ratio of mica powder:boric acid = 100:8, shearing and dispersing at 4000 r / min for 30 min to obtain a mica powder dispersion; dissolving boric acid in 3 times its mass of 55℃ warm water to obtain a boric acid solution; adding the boric acid solution dropwise to the mica powder dispersion while stirring at 300 rpm, heating to 80℃, stirring at 300 rpm for 1.5 h; spray drying to obtain a composite powder, sintering under nitrogen protection, heating to 300℃ at a rate of 2℃ / min, holding at that temperature for 30 min, continuing to heat to 500℃ at a rate of 2℃ / min, holding at that temperature for 2 h; cooling to obtain boron-modified mica powder.

[0031] The above-mentioned method for manufacturing a high-temperature resistant industrial coating includes the following steps: at a temperature below 35°C, BYK-163 dispersant, polyether-modified siloxane, and 10 parts of propylene glycol methyl ether acetate are added to a modified matrix resin, stirred at 200 rpm for 15 min, then activated filler is added, and the mixture is intermittently ground at 1800 rpm until the fineness is ≤16 μm. The temperature of the system is controlled below 35°C during the intermittent grinding condensation cycle, and grinding is paused when the temperature exceeds 35°C; vacuum defoaming is performed to obtain the coating.

[0032] Example 2

[0033] A high-temperature resistant industrial coating comprises the following raw materials in parts by weight: 105 parts phenyltrimethoxysilane, 32 parts tetraisopropyl titanate, 0.5 parts acetylacetone, 11 parts tetramethyltetraphenyltripolysiloxane, 23 parts heat-resistant modifier, 68 parts bisphenol A type epoxy resin, 2.5 parts aluminum acetylacetonate, 1.5 parts titanate coupling agent, 41 parts calcined kaolin, 26 parts boron-modified mica powder, 5 parts silicon carbide powder, 0.25 parts BYK-163 dispersant, and 0.9 parts polyether-modified siloxane, with propylene glycol methyl ether acetate as the solvent. The heat-resistant modifier is hydroxyl-terminated methyl-3,3,3-trifluoropropylsiloxane and polysiloxane; the calcined kaolin is sieved through a 1250-mesh sieve; the boron-modified mica powder has a particle size D90 of 5 μm; and the silicon carbide powder has a particle size D90 of 7 μm.

[0034] The preparation method of the modified matrix resin includes: mixing 105 parts of phenyltrimethoxysilane and 165 parts of deionized water to obtain solution A; mixing 32 parts of tetraisopropyl titanate, 0.5 parts of acetylacetone and 23 parts of propylene glycol methyl ether acetate to obtain solution B; mixing 11 parts of tetramethyltetraphenyltrisiloxane, 23 parts of heat-resistant modifier and 75 parts of propylene glycol methyl ether acetate to obtain solution C; and mixing 68 parts of bisphenol A type epoxy resin and 2.5 parts of aluminum acetylacetone to obtain solution D. Under nitrogen protection, solutions A, B, and C were mixed and stirred at 62°C and 350 rpm for 1.5 h. The mixture was then cooled to room temperature, and solution D was added dropwise over 45 min while stirring at 350 rpm. The system temperature was controlled below 80°C. After the addition was complete, the temperature was increased to 122°C at a rate of 1.5°C / min, and the mixture was stirred at 350 rpm for 1.5 h. The water was removed by vacuum distillation until the water distillate flow rate reached 3.8 mL / h, yielding the modified matrix resin.

[0035] The preparation method of the activated filler includes: mixing 1.5 parts of titanate coupling agent, 0.11 parts of acetic acid and 7 parts of anhydrous ethanol to obtain an activator; mixing 41 parts of calcined kaolin, 26 parts of boron-modified mica powder and 5 parts of silicon carbide powder, spraying the activator into the mixture while stirring at 1800 rpm, stirring and mixing at 1800 rpm for 45 min; drying at 82℃ to constant weight, and passing through a 250-mesh sieve to obtain the activated filler.

[0036] The preparation method of boron-modified mica powder includes: dispersing mica powder in 5 times its mass of deionized water according to the mass ratio of mica powder:boric acid = 100:10, shearing and dispersing at 4500 r / min for 35 min to obtain a mica powder dispersion; dissolving boric acid in 4 times its mass of 58℃ warm water to obtain a boric acid solution; adding the boric acid solution dropwise to the mica powder dispersion while stirring at 350 rpm, heating to 82℃, and stirring at 350 rpm for 1.5 h; spray drying to obtain a composite powder, sintering under nitrogen protection, heating to 320℃ at a rate of 2.5℃ / min, holding at that temperature for 35 min, continuing to heat to 520℃ at a rate of 2.5℃ / min, and holding at that temperature for 2.5 h; cooling to obtain boron-modified mica powder.

[0037] The above-mentioned method for manufacturing a high-temperature resistant industrial coating includes the following steps: at a temperature below 35°C, BYK-163 dispersant, polyether-modified siloxane, and 12 parts of propylene glycol methyl ether acetate are added to a modified matrix resin, stirred at 250 rpm for 18 minutes, then activated filler is added, and the mixture is intermittently ground at 1900 rpm until the fineness is ≤12 μm. The temperature of the system is controlled below 35°C during the intermittent grinding condensation cycle, and grinding is paused when the temperature exceeds 35°C; vacuum defoaming is performed to obtain the coating.

[0038] Example 3

[0039] A high-temperature resistant industrial coating comprises the following raw materials in parts by weight: 110 parts phenyltrimethoxysilane, 35 parts tetraisopropyl titanate, 0.6 parts acetylacetone, 12 parts tetramethyltetraphenyltripolysiloxane, 25 parts heat-resistant modifier, 70 parts bisphenol A type epoxy resin, 3 parts aluminum acetylacetonate, 2 parts titanate coupling agent, 42 parts calcined kaolin, 28 parts boron-modified mica powder, 6 parts silicon carbide powder, 0.3 parts BYK-163 dispersant, and 1.0 part polyether-modified siloxane. The solvent is propylene glycol methyl ether acetate. The heat-resistant modifier is hydroxyl-terminated methyl-3,3,3-trifluoropropylsiloxane and polysiloxane; the calcined kaolin is sieved through a 1250-mesh sieve; the boron-modified mica powder has a particle size D90 of 8 μm; and the silicon carbide powder has a particle size D90 of 5 μm.

[0040] The preparation method of the modified matrix resin includes: mixing 110 parts of phenyltrimethoxysilane and 180 parts of deionized water to obtain solution A; mixing 35 parts of tetraisopropyl titanate, 0.6 parts of acetylacetone and 25 parts of propylene glycol methyl ether acetate to obtain solution B; mixing 12 parts of tetramethyltetraphenyltrisiloxane, 25 parts of heat-resistant modifier and 80 parts of propylene glycol methyl ether acetate to obtain solution C; and mixing 70 parts of bisphenol A epoxy resin and 3 parts of aluminum acetylacetone to obtain solution D. Under nitrogen protection, solutions A, B, and C were mixed and stirred at 65°C and 400 rpm for 2 hours. The mixture was then cooled to room temperature. Solution D was then added dropwise at 400 rpm for 50 minutes, while the system temperature was kept below 80°C. After the addition was complete, the temperature was increased to 125°C at a rate of 1.5°C / min and stirred at 400 rpm for 2 hours. The water was removed by vacuum distillation until the water distillate flow rate reached 4.8 mL / h, yielding the modified matrix resin.

[0041] The preparation method of the activated filler includes: mixing 2 parts of titanate coupling agent, 0.12 parts of acetic acid and 8 parts of anhydrous ethanol to obtain an activator; mixing 42 parts of calcined kaolin, 28 parts of boron-modified mica powder and 6 parts of silicon carbide powder, spraying the activator into the mixture under stirring at 2000 rpm, stirring and mixing at 2000 rpm for 50 min; drying at 85℃ to constant weight, and passing through a 250-mesh sieve to obtain the activated filler.

[0042] The preparation method of boron-modified mica powder includes: dispersing mica powder in 6 times its mass of deionized water according to the mass ratio of mica powder:boric acid = 100:12, shearing and dispersing at 5000 r / min for 40 min to obtain a mica powder dispersion; dissolving boric acid in 5 times its mass of 60℃ warm water to obtain a boric acid solution; adding the boric acid solution dropwise to the mica powder dispersion while stirring at 400 rpm, heating to 85℃, stirring at 400 rpm for 2 h; spray drying to obtain a composite powder, sintering under nitrogen protection, heating to 350℃ at a rate of 3℃ / min, holding at 3℃ / min for 40 min, continuing to heat to 550℃ at a rate of 3℃ / min, holding at 550℃ for 3 h; cooling to obtain boron-modified mica powder.

[0043] The above-mentioned method for manufacturing a high-temperature resistant industrial coating includes the following steps: adding BYK-163 dispersant, polyether-modified siloxane, and 15 parts of propylene glycol methyl ether acetate to a modified matrix resin at a temperature below 35°C, stirring at 300 rpm for 20 min, then adding activated filler, and intermittently grinding at 2000 rpm until the fineness is ≤20 μm. The temperature of the system is controlled below 35°C during the intermittent grinding condensation cycle, and grinding is paused when the temperature exceeds 35°C; vacuum defoaming is performed to obtain the coating.

[0044] The raw materials used in the above embodiments are as follows: Phenylacetyltrimethoxysilane is from Shandong Gaotai Chemical Technology Co., Ltd., model OFS-6040. Tetraisopropyl titanate is from Wuhan Jixin Yibang Biotechnology Co., Ltd. Acetylacetone is from Shandong Yukang Chemical Co., Ltd. Tetramethyltetraphenyltripolysiloxane is from Jinjinle Chemical Co., Ltd. Hydroxyl-terminated methyl-3,3,3-trifluoropropylsiloxane and polysiloxane are from Zhengzhou Alpha Chemical Co., Ltd., hydroxyl-terminated methyl-3,3,3-trifluoropropyl (siloxane and polysiloxane). Bisphenol A type epoxy resin is from Guangzhou Diweisai New Materials Co., Ltd., produced by Baling Petrochemical, model E-44. Aluminum acetylacetone is from Jinan Zhiheng Zhiyuan Chemical Technology Co., Ltd. Titanate coupling agent is from Guangdong Wengjiang Chemical Reagent Co., Ltd., model NDZ-201. Calcined kaolin is from Zhejiang Changxing Zhonghong New Materials Co., Ltd., 1250 mesh grade. Mica powder is from Lingshou County Baofeng Mica Processing Co., Ltd. Boric acid is from Henan Tuoyuan Chemical Products Co., Ltd. The silicon carbide powder was sourced from Qinghe County Benyu Metal Materials Co., Ltd., and was ground into spherical silicon carbide micro powder. BYK-163 dispersant was BYK 163 dispersant. The polyether-modified siloxane was sourced from Guangdong Fangzhou Chemical Industry Co., Ltd., model AC-408. Propylene glycol methyl ether acetate was sourced from Shandong Juxing Chemical Co., Ltd.

[0045] Comparative Example 1

[0046] The difference from Example 1 is that the amount of tetramethyltetraphenyltrisiloxane added is changed to 5 parts.

[0047] Comparative Example 2

[0048] The difference from Example 1 is that the amount of tetramethyltetraphenyltrisiloxane added is changed to 20 parts.

[0049] Comparative Example 3

[0050] The difference from Example 1 is that the amount of temperature-resistant modifier added is changed to 10 parts.

[0051] Comparative Example 4

[0052] The difference from Example 1 is that the amount of temperature-resistant modifier added is changed to 35 parts.

[0053] Comparative Example 5

[0054] The difference from Example 1 is that the amount of tetramethyltetraphenyltrisiloxane added is changed to 5 parts; and the amount of heat-resistant modifier added is changed to 30 parts.

[0055] Comparative Example 6

[0056] The difference from Example 1 is that the amount of tetramethyltetraphenyltrisiloxane added is changed to 16 parts; and the amount of heat-resistant modifier added is changed to 10 parts.

[0057] Comparative Example 7

[0058] The difference from Example 1 is that boron-modified mica powder is replaced with mica powder.

[0059] Comparative Example 8

[0060] The difference from Example 1 is that in the preparation method of the modified matrix resin, after mixing the liquid A, liquid B and liquid C, liquid D is directly added dropwise for 40 minutes, while the system temperature is controlled below 80°C. After the addition is complete, the temperature is increased to 120°C at a rate of 1°C / min, and the mixture is stirred at 300 rpm for 1.5 hours. The water is removed by vacuum distillation until the water distillate reaches 4.2 mL / h, thus obtaining the modified matrix resin.

[0061] Comparative Example 9

[0062] The difference from Example 1 is that no titanate coupling agent is added, no filler activation is performed, and the filler is directly obtained by mixing calcined kaolin, boron-modified mica powder and silicon carbide powder.

[0063] I. Sample Preparation:

[0064] Substrate treatment: Q235 steel plate (150×70×1mm) with sandblasting and rust removal; Curing procedure: heat to 80℃ and cure for 1 hour, then heat to 120℃ and cure for 1 hour, then heat to 200℃ and cure for 1 hour; Coating thickness: dry film thickness 80±2μm.

[0065] II. Testing Items:

[0066] 1. Temperature resistance limit (GB / T1735): Place the sample in a high-temperature furnace and heat it. Starting from 450℃, observe the surface condition of the coating every 10℃. Record the temperature at which obvious blistering, cracking, peeling and other destructive phenomena occur in the coating. This temperature is the temperature resistance limit.

[0067] 2. Thermal weight loss rate (600℃ / 24h, GB / T27761): Weigh the initial mass m1 of the sample, place the sample in a high-temperature furnace that has been kept at 600℃ for 24h, take it out, cool it to room temperature in a desiccator, weigh the mass m2 again, and calculate the thermal weight loss rate.

[0068] 3. Adhesion (cross-cut test, GB / T9286):

[0069] Use a cross-cutting tool to cut 1mm × 1mm squares on the coating surface, extending the cuts to the substrate surface. Cut three areas for each sample. Apply 3M tape (600 type) tightly to the cut areas, and roll it back and forth 5 times with a rubber roller at a pressure of 5 N / cm. Then, quickly peel off the tape at a 90° angle. Observe the removal of squares under a microscope and perform an adhesion rating.

[0070]

[0071] 4. Impact Resistance (Falling Ball Impact, GB / T1732): Fix the sample horizontally on the test platform of the impact testing machine, and use a 1kg steel ball to drop freely from different heights (increasing by 5cm each time) to impact the center of the coating surface, with 3 impacts at each height. Observe the coating surface for any cracks, peeling, or other damage, and record the maximum height from which no damage occurs as the impact resistance value.

[0072] 5. Salt spray resistance (1000h, GB / T1771): Place the sample in a salt spray test chamber using a 5wt% NaCl solution. Maintain the pH at 6.8 and the temperature at 35℃. The salt spray deposition should be 2 mL / (80cm²). 2 •h), observe the time when corrosion appears on the coating surface (observe once every 50h).

[0073] 6. Acid Resistance (10% H2SO4 / 168h): Weigh the initial mass m1 of the sample, completely immerse the sample in a 10% H2SO4 solution, ensuring the solution volume completely covers the sample, and maintain this at a constant temperature of 25℃ for 168h. Remove the sample, rinse it thoroughly with clean water, dry it, and weigh it again (m2). Calculate the acid resistance weight loss rate.

[0074] 7. Alkali Resistance (10% NaOH / 168h): Weigh the initial mass m1 of the sample, completely immerse the sample in a 10% NaOH solution, ensuring the solution volume completely covers the sample, and maintain this solution at a constant temperature of 25℃ for 168h. Remove the sample, rinse it thoroughly with clean water, dry it, and weigh it again (m2). Calculate the alkali resistance weight loss rate.

[0075] Three parallel samples were used for each experiment, and the average value was taken. The test results are shown in Table 1 below:

[0076] Table 1 Test Results

[0077]

[0078] The results above show that the formulation ratios of Examples 1 to 3 have a synergistic effect, resulting in good modification effects, effectively improving high-temperature stability, and balancing other mechanical properties and corrosion resistance.

[0079] In Comparative Example 1, the amount of tetramethyltetraphenyltrisiloxane added was reduced to 5 parts. Tetramethyltetraphenyltrisiloxane can participate in the cross-linking reaction of the coating matrix resin, forming a more stable three-dimensional network structure. With reduced addition, the density of the Si-O-Si cross-linking network decreased, and the interaction between molecular chains weakened. Under high-temperature conditions, the molecular chains are more prone to thermal motion and breakage, leading to a decrease in the temperature resistance limit and an increase in thermal weight loss. The imperfect cross-linking network results in poorer adhesion between the coating and the substrate; simultaneously, the coating's resistance to external impacts decreases. In salt spray, acid and alkali environments, corrosive media and moisture can more easily penetrate into the coating, causing corrosion and damage.

[0080] In Comparative Example 2, the addition of tetramethyltetraphenyltrisiloxane was increased to 20 parts, which to some extent increased the crosslinking points and improved the temperature resistance of the three-dimensional Si-O-Si network. However, excessive tetramethyltetraphenyltrisiloxane would significantly increase the viscosity of the coating system, leading to over-crosslinking. This would make solvent evaporation difficult during film formation, easily forming defects such as pores inside the coating and affecting its density. Excessive amounts would cause phase separation due to the difference in polarity with epoxy, and excessive aggregation would lead to stress concentration, making it prone to cracking upon impact. The film quality would be poor, with reduced impact resistance and corrosion resistance, making it difficult to achieve a good balance between high-temperature resistance, impact resistance, and corrosion resistance.

[0081] In Comparative Example 3, the amount of heat-resistant modifier added was reduced to 10 parts. The hydroxyl-terminated methyl-3,3,3-trifluoropropyl (siloxane and polysiloxane) in the heat-resistant modifier effectively improves the high-temperature resistance and chemical stability of the coating. When the amount added is insufficient, the hydroxyl-terminated fluorosilicone segments are insufficient, and the coating cannot form a sufficiently stable molecular structure to resist thermal decomposition at high temperatures, resulting in decreased heat resistance. The lack of fluorosilicone chains weakens the resistance to chemical media, and the reduced chemical stability also makes it more susceptible to chemical reactions in acidic and alkaline environments, leading to decreased corrosion resistance; at the same time, the ability to protect the substrate decreases.

[0082] In Comparative Example 4, the amount of heat-resistant modifier added was increased to 35 parts. Excessive heat-resistant modifier causes excessively long and entangled molecular chains in the coating system, restricting their movement and making it difficult to form a uniform and ordered structure during film formation. Solvent evaporation is difficult during film formation, easily leading to defects such as pores within the coating, affecting its density. Excessive fluorosilicone segments migrate to the coating surface, reducing chemical bonding with the substrate, worsening the compatibility between the fluorosilicone and epoxy phases, and causing phase separation leading to stress concentration. Although the intermolecular forces are enhanced, internal stress also increases. At high temperatures, the release of internal stress causes microcracks in the coating, affecting its high-temperature resistance. Stress concentration areas also become channels for the penetration of corrosive media and moisture, reducing the coating's protective performance.

[0083] In Comparative Example 5, the amount of tetramethyltetraphenyltrisiloxane added was reduced to 5 parts, while the amount of heat-resistant modifier added was increased to 30 parts. This unreasonable change in the amounts of both resulted in the loss of synergistic effects. The low degree of crosslinking and high fluorine-silicone content led to a loose structure, severely hindering the construction of the crosslinked network and the formation of a thermally stable structure in the coating system. The combined effects of insufficient crosslinking and excessive molecular chain entanglement caused the coating to be highly susceptible to decomposition and damage at high temperatures. Furthermore, its mechanical and protective properties declined sharply.

[0084] In Comparative Example 6, the amount of tetramethyltetraphenyltrisiloxane was increased to 16 parts, while the amount of heat-resistant modifier was reduced to 10 parts. This combination resulted in poor film quality due to excessive tetramethyltetraphenyltrisiloxane and decreased thermal stability due to insufficient heat-resistant modifier. High crosslinking restricts chain segment movement, residual stress induces microcracks, and the coating is prone to thermal degradation and structural damage at high temperatures. Poor film quality and thermal stability also severely affect the adhesion and corrosion resistance of the coating.

[0085] In Comparative Example 7, boron-modified mica powder was used as a substitute for regular mica powder. Boron-modified mica powder, through modification with boron, enhances its compatibility and interfacial bonding with the coating matrix. Simultaneously, its unique layered structure effectively blocks the penetration of corrosive media. Ordinary mica powder primarily binds to the coating matrix through physical adsorption, resulting in weak bonding and ineffective shielding. Ordinary mica powder does not form a borosilicate glass phase and lacks melting and pore-sealing properties at high temperatures. At high temperatures, the coating's internal structure lacks effective support and stability, leading to decreased temperature resistance. The filler-resin interfacial bonding is weak, accelerating the decomposition of high-temperature components. In various corrosive environments, corrosive media easily penetrate to the substrate surface. Poor interfacial compatibility results in uneven dispersion, unstable mechanical properties, and poor overall performance.

[0086] In Comparative Example 8, the preparation method of the modified matrix resin involved altering the order of feeding and reaction conditions. This resulted in insufficient reaction between the raw materials, failure to perform stepwise grafting, and direct mixing, leading to partial phase separation. The original stepwise reaction and specific temperature and time control were intended to allow each raw material to undergo sufficient hydrolysis, condensation, and other reactions to form a stable molecular structure and a good cross-linking network. After the changes, the connection and degree of cross-linking of the molecular chains were insufficient, reducing the stability of the molecular structure and causing a decline in overall performance.

[0087] In Comparative Example 9, no titanate coupling agent was added, and no filler activation was performed. Titanate coupling agents can form chemical bonds on the filler surface, with one end reacting with the active groups on the filler surface and the other end interacting with the coating matrix resin, thereby enhancing the interfacial bonding between the filler and the matrix. Unactivated fillers rely only on weak physical adsorption to the matrix, resulting in a weak bond, increased coating porosity, and uncoupled fillers acting as stress concentration points, initiating crack propagation. Under high temperature and corrosive environments, the filler is prone to detaching from the coating, compromising its integrity.

Claims

1. A high-temperature resistant industrial coating, characterized in that, The coating comprises the following raw materials in parts by weight: modified matrix resin, activated filler, 0.2 to 0.3 parts of BYK-163 dispersant, 0.8 to 1.0 parts of polyether-modified siloxane, and propylene glycol methyl ether acetate as solvent; The preparation method of the modified matrix resin includes: mixing 100-110 parts by mass of phenyltrimethoxysilane and 150-180 parts by mass of deionized water to obtain solution A; mixing 30-35 parts by mass of tetraisopropyl titanate, 0.4-0.6 parts by mass of acetylacetone and 20-25 parts by mass of propylene glycol methyl ether acetate to obtain solution B; mixing 10-12 parts by mass of tetramethyltetraphenyltripolysiloxane, 20-25 parts by mass of a heat-resistant modifier and 70-80 parts by mass of propylene glycol methyl ether acetate to obtain solution C; and mixing... 65-70 parts of bisphenol A type epoxy resin and 2-3 parts of aluminum acetylacetonate were mixed to obtain solution D; under nitrogen protection, solutions A, B and C were mixed and stirred at 60-65°C, then cooled to room temperature. Solution D was then added dropwise with stirring, while the system temperature was controlled below 80°C. After the addition was complete, the temperature was raised to 120-125°C and stirred. The water was removed by vacuum distillation to obtain the modified matrix resin; the temperature-resistant modifier was hydroxyl-terminated methyl-3,3,3-trifluoropropylsiloxane and polysiloxane. The preparation method of the activated filler includes: mixing 1 to 2 parts by mass of titanate coupling agent, 0.1 to 0.12 parts by mass of acetic acid and 6 to 8 parts by mass of anhydrous ethanol to obtain an activator; mixing 40 to 42 parts by mass of calcined kaolin, 25 to 28 parts by mass of boric acid modified mica powder and 4 to 6 parts by mass of silicon carbide powder, spraying the activator into the mixture under stirring, stirring and mixing; drying and sieving to obtain the activated filler; The preparation method of the boric acid modified mica powder includes: dispersing mica powder in deionized water according to the mass ratio of mica powder:boric acid = 100:(8-12) to obtain a mica powder dispersion; dissolving boric acid in warm water to obtain a boric acid solution; adding the boric acid solution dropwise into the mica powder dispersion under stirring, heating to 80℃~85℃, and stirring for 1.5h~2h; spray drying to obtain a composite powder, sintering, and cooling to obtain boric acid modified mica powder.

2. The high-temperature resistant industrial coating according to claim 1, characterized in that, In the preparation method of the modified matrix resin, the stirring speed is 300 rpm to 400 rpm; the stirring reaction time is 1.5 h to 2 h; the dropping time is 40 min to 50 min; the heating rate is 1 °C / min to 1.5 °C / min; and the vacuum distillation is stopped when the water distillate is <5 mL / h.

3. The high-temperature resistant industrial coating according to claim 1, characterized in that, In the preparation method of the activated filler, the stirring speed is 1500 rpm to 2000 rpm; the stirring and mixing time is 40 min to 50 min; the drying is carried out at 80℃ to 85℃ until constant weight; and the sieving is carried out through a 200 mesh to 250 mesh sieve.

4. The high-temperature resistant industrial coating according to claim 1, characterized in that, The calcined kaolin is sieved through a 1250-mesh sieve; the boric acid-modified mica powder has a particle size D90 < 10 μm; and the silicon carbide powder has a particle size D90 < 10 μm.

5. The high-temperature resistant industrial coating according to claim 1, characterized in that, A method for preparing boric acid-modified mica powder, wherein the amount of deionized water is 4 to 6 times the mass of the mica powder; the dispersion is performed by shear dispersion at 4000 r / min to 5000 r / min for 30 min to 40 min; the temperature of the warm water is 55℃ to 60℃, and the amount of warm water is 3 to 5 times the mass of the boric acid; the stirring speed is 300 rpm to 400 rpm; the sintering parameters are: heating to 300℃ to 350℃, holding for 30 min to 40 min, continuing to heat to 500℃ to 550℃, and holding for 2 h to 3 h; the heating rate is 2℃ / min to 3℃ / min.

6. The method for manufacturing a high-temperature resistant industrial coating as described in claim 1, characterized in that, The process includes the following steps: At a temperature below 35°C, BYK-163 dispersant, polyether-modified siloxane, and propylene glycol methyl ether acetate are added to the modified matrix resin, stirred, followed by the addition of activated filler, intermittent grinding, and vacuum defoaming to obtain the coating.

7. The method for manufacturing a high-temperature resistant industrial coating according to claim 6, characterized in that, The stirring is performed at 200 rpm to 300 rpm for 15 min to 20 min; the intermittent grinding is performed at 1800 rpm to 2000 rpm until the fineness is ≤20 μm; the temperature of the intermittent grinding is controlled below 35℃.

Images