High-temperature-resistant industrial coating and manufacturing method thereof

Abstract

The invention relates to a high-temperature-resistant industrial coating and a preparation method thereof, and belongs to the technical field of paints.The preparation method comprises the steps that phenyltrimethoxysilane, tetraisopropyl titanate, acetylacetone, tetramethyl tetraphenyl tripolysiloxane and a temperature-resistant modifier are adopted to react, and then the product reacts with bisphenol A epoxy resin and aluminum acetylacetonate to prepare modified matrix resin; the calcined kaolin, the boron modified mica powder and the silicon carbide powder are activated through a titanate coupling agent, and activated filler is obtained; the coating prepared by matching the modified matrix resin, the activated filler and other auxiliary components forms a high-temperature-resistant, strong-adhesion and corrosion-resistant composite coating system through a multi-component synergistic effect and process optimization, and other application performances can be well balanced while the high temperature resistance is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coatings, and particularly relates to a high-temperature-resistant industrial coating and a manufacturing method thereof. BACKGROUND

[0002] Under the tide of modern industrial rapid development, various industrial equipment and facilities are facing increasingly severe high-temperature environment tests. From the energy field of thermal power plants and nuclear power plants, to the high-temperature reaction kettles and cracking furnaces of the chemical industry, to the aircraft engines of aerospace, high-temperature working conditions are everywhere. This makes high-temperature-resistant industrial coatings become the key material to ensure the stable operation of equipment and prolong the service life.

[0003] Traditional ordinary coatings have many defects in high-temperature environments. When the temperature rises, the molecular structure of ordinary coatings will change, causing the coating to soften, bubble and even fall off. For example, ordinary coatings are brushed on the surface of some industrial boilers, and after a long time of high-temperature baking, the coating quickly appears a pulverization phenomenon, which cannot effectively protect the boiler, thereby accelerating the corrosion and damage of the equipment, increasing the maintenance cost and safety hazards of the equipment. In the field of aerospace, the surface of the aircraft rubs against the air at high speed, generating extremely high temperature, and ordinary coatings cannot withstand such high-temperature impact, and cannot meet the requirements of light weight, high strength and special functionality of the aircraft.

[0004] In order to solve these problems, high-temperature-resistant industrial coatings have emerged as the times require. Early high-temperature-resistant coatings mainly used silicone resin as the base material, and used the high bond energy of silicon-oxygen bond (Si-O) to provide certain thermal stability, which could withstand temperatures of 300-500℃. However, this type of coating also has some limitations, such as poor mechanical properties, poor adhesion, insufficient wear resistance, and low solvent resistance, etc., which makes it difficult to meet the actual needs in some occasions with high comprehensive performance requirements. With the progress of science and technology, a series of heterocyclic polymers have been applied to high-temperature-resistant coatings. These polymers have excellent heat resistance, radiation resistance, oil resistance, hydrolysis resistance and wear resistance, etc., which effectively improve the performance of the coatings. For example, polyimide, as a high-performance heterocyclic polymer, is widely used in high-temperature-resistant coatings in the field of aerospace. It can withstand high temperatures of more than 500℃, and has good mechanical properties and electrical insulation properties, which can meet the use requirements of key components such as aircraft engines 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 nano materials (such as nano oxides, nano carbon tubes, etc.) into the coating system, the performance of the coating can be significantly improved. Nano materials have high specific surface area, small size effect and quantum size effect, etc., which can enhance the adhesion, hardness, wear resistance and high-temperature resistance of the coating.

[0006] Although high-temperature resistant industrial coatings have made significant progress, in the face of ever-increasing industrial needs, it is still necessary to continuously develop and improve a new generation of high-temperature resistant coatings to better serve industrial development and extend the protection life. Summary of the Invention

[0007] In order to further improve the protective performance of the coating, improve high temperature resistance and balance other application properties (including high humidity resistance, corrosion resistance, etc.), the present invention provides a high temperature resistant industrial coating and its manufacturing method, which uses phenyltrimethoxysilane, tetraisopropyl titanate, acetylacetone, tetramethyltetraphenyl trisiloxane and a heat-resistant modifier to react, and then react with bisphenol A epoxy resin and aluminum acetylacetonate to obtain a modified base resin; calcined kaolin, boron-modified mica powder and silicon carbide powder are activated by a titanate coupling agent to obtain an activated filler; the coating prepared by combining the modified base resin, the activated filler and other auxiliary ingredients forms a high temperature resistant, strongly adhered and corrosion-resistant composite coating system through multi-component synergy and process optimization, which can well balance other application properties while improving high temperature resistance. Its specific technical solution is as follows:

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

[0009] The preparation method of the modified matrix resin comprises the following steps: mixing 100-110 parts of phenyltrimethoxysilane and 150-180 parts of deionized water to obtain a liquid 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 a liquid B; mixing 10-12 parts of tetramethyltetraphenyl trisiloxane, 20-25 parts of a temperature-resistant modifier and 70-80 parts of propylene glycol methyl ether acetate to obtain a liquid C; mixing 65-70 parts of bisphenol A type epoxy resin and 2-3 parts of acetylacetone aluminum to obtain a liquid D; mixing the liquid A, the liquid B and the liquid C under nitrogen protection, stirring and reacting at 60-65°C, then adding the liquid D dropwise under stirring while controlling the system temperature below 80°C, and then stirring and reacting at 120-125°C after the addition is completed, and removing water by distillation under reduced pressure to obtain the modified matrix resin.

[0010] In the preparation method of the modified matrix resin, the stirring speed is 300-400 rpm, the stirring reaction time is 1.5-2 hours, the dropping time is 40-50 minutes, the heating rate is 1-1.5°C / min, and the distillation under reduced pressure is stopped when the water distillate is less than 5 mL / h.

[0011] In the coating, the preparation method of the activated filler comprises the following steps: mixing 1-2 parts of a titanate coupling agent, 0.1-0.12 parts of acetic acid and 6-8 parts of anhydrous ethanol to obtain an activating agent; mixing 40-42 parts of calcined kaolin, 25-28 parts of boron-modified mica powder and 4-6 parts of silicon carbide powder, spraying the activating agent under stirring and stirring and mixing; drying and sieving to obtain the activated filler.

[0012] In the preparation method of the activated filler, the stirring speed is 1500-2000 rpm, the stirring and mixing time is 40-50 minutes, the drying is carried out at 80-85°C until the weight is constant, and the sieving is carried out through a 200-250 mesh sieve.

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

[0014] The preparation method of the boron-modified mica powder comprises the following steps: 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; under stirring, the boric acid solution is added dropwise into the mica powder dispersion, and the temperature is raised to 80-85 DEG C, and stirring is carried out for 1.5-2 hours; spray drying is carried out to obtain a composite powder, and sintering and cooling are carried out to obtain the boron-modified mica powder.

[0015] In the preparation method of the boron-modified mica powder, the amount of the deionized water is 4-6 times the mass of the mica powder; the dispersion is shearing dispersion at 4000-5000 r / min for 30-40 min; the temperature of the warm water is 55-60 DEG C, and the amount of the warm water is 3-5 times the mass of the boric acid; the stirring speed is 300-400 rpm; the sintering parameters are as follows: the temperature is raised to 300-350 DEG C, and the temperature is kept for 30-40 min, then the temperature is continuously raised to 500-550 DEG C, and the temperature is kept for 2-3 hours; the uniform heating rate is 2-3 DEG C / min.

[0016] The manufacturing method of the high-temperature-resistant industrial coating comprises the following steps: at 35 DEG C or below, BYK-163 dispersant, polyether-modified siloxane and propylene glycol methyl ether acetate are added into a modified matrix resin, stirring is carried out, then activated fillers are added, intermittent grinding is carried out, vacuum defoaming is carried out, and the coating is obtained.

[0017] In the manufacturing method, the stirring is carried out at 200-300 rpm for 15-20 min; the intermittent grinding is carried out at 1800-2000 rpm until the fineness is less than or equal to 20 mu m; and the intermittent grinding is controlled at a temperature of 35 DEG C or below.

[0018] The high-temperature-resistant industrial coating and the manufacturing method thereof have the following beneficial effects:

[0019] I. Synergistic construction of high-temperature-resistant performance: phenyltrimethoxysilane and tetramethyltetraphenyltrisiloxane form a heat-stable network through Si-O-Si bond, and the fluorosilicon chain segment in the temperature-resistant modifier further improves the thermal stability of the molecular chain, so that the coating can still maintain structural integrity at high temperature. The crosslinking reaction of bisphenol A type epoxy resin and acetylacetone aluminum enhances the network density and avoids the molecular chain rupture at high temperature.

[0020] II. Strengthening of mechanical properties and adhesion: the fillers such as calcined kaolin and boron-modified mica powder activated by titanate coupling agent are combined with the resin matrix through chemical bond to form a "rigid skeleton", which improves the hardness and impact resistance of the coating; at the same time, the epoxy groups in the modified matrix resin form chemical anchoring with the substrate, so that the adhesion is better.

[0021] Three, the multiple construction of corrosion resistance barrier: the layered structure of boron modified mica powder can physically block the penetration of salt spray, acid and alkali medium, and the borate glass phase on the surface can melt and seal the pores at high temperature, further isolating the corrosion medium; the low surface energy characteristics of fluorosilicon segments reduce medium adsorption, combined with a dense resin network, effectively improving corrosion resistance.

[0022] Four, the multiple contribution of the base resin component: phenyl trimethoxysilane hydrolysis and condensation form Si-O-Si main chain, bond energy is higher than ordinary C-C bond, not easy to break at high temperature, providing basic thermal stability for the coating; after crosslinking with titanium acid tetraisopropyl ester, an interpenetrating network is formed, improving mechanical strength. The introduction of phenyl side chains by tetramethyltetraphenyl trisiloxane increases the steric hindrance of the molecular chain, inhibits the movement of the chain segment at high temperature, and when the addition amount is 10-12 parts, the Si-O-Si network density is optimal, and excessive amount will cause phase separation. The hydroxyl-terminated fluorosilicon segment of the temperature-resistant modifier is connected to the resin network through condensation reaction, and the electronegativity of fluorine atom forms an "electronic barrier" to prevent oxygen radicals from invading, while reducing the surface energy of the coating and improving solvent resistance; insufficient addition will cause the thermal decomposition temperature of the coating to decrease. The epoxy groups of bisphenol A type epoxy resin react with the hydroxyl groups produced by the hydrolysis of siloxane to form a "siloxane-epoxy" hybrid structure, combining the toughness of epoxy resin and the high temperature resistance of siloxane.

[0023] Five, the role of fillers and additives: boron modified mica powder forms borosilicate glass phase by boric acid sintering, which melts and fills the pores of the coating at high temperature, prolonging the penetration path of the corrosion medium; unmodified mica powder has a shortened salt spray resistance time due to the lack of borate phase. The alkoxy groups in the molecule of titanate coupling agent react with the surface hydroxyl groups of fillers (kaolin, silicon carbide), and the organic long chains are entangled with the resin matrix to form a "filler-coupling agent-resin" chemical bridge, improving the dispersibility of fillers and avoiding stress concentration. BYK-163 dispersant is adsorbed on the surface of fillers through anchoring groups to form steric hindrance, preventing agglomeration and making fillers disperse in the resin to improve the uniformity of the coating.

[0024] Six, the mechanism of special process steps on performance: in the preparation of modified base resin, the temperature is controlled in steps, the silane is first hydrolyzed to form a prepolymer at 60-65°C, and then the temperature is raised to 120-125°C to promote the crosslinking of epoxy and siloxane. If the intermediate temperature reduction step is omitted, phase separation will occur and the temperature resistance limit will decrease. Water is removed by vacuum distillation, and the water distillate is controlled at <5 mL / h to avoid residual water vaporization at high temperature to form bubbles, affecting the density of the coating. Boron modified mica powder is sintered at high temperature, and the boron-oxygen bond is formed by the reaction of boric acid and the surface hydroxyl groups of mica through step-by-step sintering, improving the compatibility with the resin. DETAILED DESCRIPTION

[0025] The application will be further described below in conjunction with specific implementation examples, but the application is not limited to these examples.

[0026] Example 1

[0027] A high-temperature-resistant industrial coating, the coating comprising raw materials in the following mass fractions: 100 parts of phenyltrimethoxysilane, 30 parts of tetraisopropyl titanate, 0.4 parts of acetylacetone, 10 parts of tetramethyltetraphenyl trisiloxane, 20 parts of temperature-resistant modifier, 65 parts of bisphenol A type epoxy resin, 2 parts of acetylacetone aluminum, 1 part of titanate coupling agent, 40 parts of calcined kaolin, 25 parts of boron-modified mica powder, 4 parts of silicon carbide powder, 0.2 parts of BYK-163 dispersant, and 0.8 parts of polyether-modified siloxane, and the solvent is propylene glycol methyl ether acetate. Among them, the temperature-resistant modifier is hydroxyl-terminated methyl-3,3,3-trifluoropropyl siloxane and polysiloxane; the calcined kaolin is below 1250 mesh; 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 comprises the following steps: mixing 100 parts of phenyltrimethoxysilane and 150 parts of deionized water to obtain a liquid A; mixing 30 parts of tetraisopropyl titanate, 0.4 parts of acetylacetone, and 20 parts of propylene glycol methyl ether acetate to obtain a liquid B; mixing 10 parts of tetramethyltetraphenyl trisiloxane, 20 parts of temperature-resistant modifier, and 70 parts of propylene glycol methyl ether acetate to obtain a liquid C; mixing 65 parts of bisphenol A type epoxy resin and 2 parts of acetylacetone aluminum to obtain a liquid D; mixing the liquid A, the liquid B, and the liquid C under nitrogen protection, stirring at 60 ℃ and 300 rpm for 1.5 h, reducing to room temperature, then adding the liquid D dropwise under stirring at 300 rpm, the dropwise adding time being 40 min, while controlling the system temperature to be below 80 ℃, after the dropwise adding, heating to 120 ℃ at a rate of 1 ℃ / min, stirring at 300 rpm for 1.5 h, removing water by distillation under reduced pressure until the water distillate is 4.2 mL / h, and stopping, to obtain the modified matrix resin.

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

[0030] The preparation method of the boron-modified mica powder comprises the following steps: dispersing mica powder in deionized water in a mass ratio of mica powder:boric acid = 100:8, shearing and dispersing for 30 min at 4000 r / min to obtain a mica powder dispersion liquid; dissolving boric acid in 3 times the mass of warm water at 55 DEG C to obtain a boric acid solution; under stirring at 300 rpm, the boric acid solution is added dropwise into the mica powder dispersion liquid, and the temperature is raised to 80 DEG C, and stirring is carried out at 300 rpm for 1.5 h; spray drying is carried out to obtain a composite powder, and the composite powder is sintered under nitrogen protection, the temperature is raised to 300 DEG C at a rate of 2 DEG C / min, and the temperature is kept for 30 min, and then the temperature is continuously raised to 500 DEG C at a rate of 2 DEG C / min, and the temperature is kept for 2 h; and cooling is carried out to obtain the boron-modified mica powder.

[0031] The manufacturing method of the high-temperature-resistant industrial coating comprises the following steps: adding BYK-163 dispersant, polyether-modified siloxane and 10 parts of propylene glycol methyl ether acetate into the modified matrix resin below 35 DEG C, stirring at 200 rpm for 15 min, then adding the activated filler, and intermittently grinding to a fineness of ≤16 μm at 1800 rpm, and the condensation cycle control system temperature of the intermittent grinding is below 35 DEG C, and the grinding is paused when the temperature exceeds 35 DEG C; vacuum defoaming is carried out to obtain the coating.

[0032] Example 2

[0033] A high-temperature-resistant industrial coating, the coating comprises the following raw materials in mass parts: 105 parts of phenyltrimethoxysilane, 32 parts of tetraisopropyl titanate, 0.5 parts of acetylacetone, 11 parts of tetramethyltetraphenyltrisiloxane, 23 parts of temperature-resistant modifier, 68 parts of bisphenol A type epoxy resin, 2.5 parts of acetylacetone aluminum, 1.5 parts of titanate coupling agent, 41 parts of calcined kaolin, 26 parts of boron-modified mica powder, 5 parts of silicon carbide powder, 0.25 parts of BYK-163 dispersant and 0.9 parts of polyether-modified siloxane, and the solvent is propylene glycol methyl ether acetate. The temperature-resistant modifier is hydroxyl-terminated methyl-3,3,3-trifluoropropylsiloxane and polysiloxane; the calcined kaolin is below 1250 mesh; 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 comprises: mixing 105 parts of phenyltrimethoxysilane and 165 parts of deionized water to obtain a feed liquid A; mixing 32 parts of titanium isopropylate, 0.5 parts of acetylacetone and 23 parts of propylene glycol methyl ether acetate to obtain a feed liquid B; mixing 11 parts of tetramethyltetraphenyl trisiloxane, 23 parts of a temperature-resistant modifier and 75 parts of propylene glycol methyl ether acetate to obtain a feed liquid C; mixing 68 parts of bisphenol A type epoxy resin and 2.5 parts of acetylacetone aluminum to obtain a feed liquid D; mixing the feed liquid A, the feed liquid B and the feed liquid C under nitrogen protection, stirring at 62 ℃ and 350 rpm for 1.5 h, then dropping the feed liquid D under stirring at 350 rpm, the dropping time is 45 min, the system temperature is controlled below 80 ℃ at the same time, after dropping, the temperature is raised to 122 ℃ at a rate of 1.5 ℃ / min, stirring at 350 rpm for 1.5 h, removing water by reduced pressure distillation until the water distillate is 3.8 mL / h, and stopping, to obtain the modified matrix resin.

[0035] The preparation method of the activated filler comprises: mixing 1.5 parts of a titanate coupling agent, 0.11 parts of acetic acid and 7 parts of anhydrous ethanol to obtain an activating agent; mixing 41 parts of calcined kaolin, 26 parts of boron-modified mica powder and 5 parts of silicon carbide powder, spraying the activating agent under stirring at 1800 rpm, and stirring and mixing for 45 min under 1800 rpm; drying at 82 ℃ until the weight is constant, and then screening through a 250-mesh screen to obtain the activated filler.

[0036] The preparation method of the boron-modified mica powder comprises: dispersing mica powder in 5 times the mass of deionized water according to the mass ratio of mica powder to boric acid of 100:10, shearing and dispersing for 35 min at 4500 r / min to obtain a mica powder dispersion liquid; dissolving boric acid in 4 times the mass of warm water at 58 ℃ to obtain a boric acid solution; dropping the boric acid solution into the mica powder dispersion liquid under 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, keeping for 35 min, continuing to heat to 520 ℃ at a rate of 2.5 ℃ / min, and keeping for 2.5 h; cooling to obtain the boron-modified mica powder.

[0037] The above-mentioned method for manufacturing the high-temperature-resistant industrial coating comprises the following steps: adding BYK-163 dispersant, polyether-modified siloxane and 12 parts of propylene glycol methyl ether acetate to the modified matrix resin below 35 ℃, stirring at 250 rpm for 18 min, then adding the activated filler, and intermittently grinding to a fineness of ≤12 μm at 1900 rpm; the condensation cycle of the intermittent grinding controls the system temperature below 35 ℃, and the grinding is paused when the temperature exceeds 35 ℃; vacuum defoaming to obtain the coating.

[0038] Example 3

[0039] A kind of high-temperature resistant industrial coating, coating includes the following mass parts of raw materials: 110 parts phenyl trimethoxysilane, 35 parts titanium acid tetraisopropyl ester, 0.6 parts acetylacetone, 12 parts tetramethyl tetraphenyl trisiloxane, 25 parts temperature resistant modifier, 70 parts bisphenol A type epoxy resin, 3 parts acetylacetone aluminum, 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 parts polyether modified siloxane, solvent is propylene glycol methyl ether acetate. Wherein, temperature resistant modifier is hydroxyl-terminated methyl-3,3,3-trifluoropropyl siloxane and polysiloxane;Calcined kaolin is below 1250 mesh screen;Boron modified mica powder is particle size D90 8 μm;Silicon carbide powder particle size D90 is 5 μm.

[0040] Wherein, the preparation method of modified matrix resin includes: 110 parts phenyl trimethoxysilane and 180 parts of deionized water are mixed to obtain liquor A;35 parts of titanium acid tetraisopropyl ester, 0.6 parts of acetylacetone and 25 parts of propylene glycol methyl ether acetate are mixed to obtain liquor B;12 parts of tetramethyl tetraphenyl trisiloxane, 25 parts of temperature resistant modifier and 80 parts of propylene glycol methyl ether acetate are mixed to obtain liquor C;70 parts of bisphenol A type epoxy resin and 3 parts of acetylacetone aluminum are mixed to obtain liquor D;Under the protection of nitrogen, liquor A, liquor B and liquor C are mixed, and the stirring reaction is carried out at 65 DEG C and 400 rpm for 2 h, and then the temperature is reduced to room temperature, then liquor D is added dropwise under the stirring of 400 rpm, the dropwise time is 50 min, the system temperature is controlled below 80 DEG C at the same time, after dropping, the temperature is increased to 125 DEG C at the rate of 1.5 DEG C / min, and the stirring reaction is carried out at 400 rpm for 2 h, and the water is removed by distillation under reduced pressure, until the water distillate is 4.8 mL / h, stop, to obtain modified matrix resin.

[0041] Wherein, the preparation method of activated filler includes: 2 parts of titanate coupling agent, 0.12 parts of acetic acid and 8 parts of anhydrous ethanol are mixed to obtain activator;42 parts of calcined kaolin, 28 parts of boron modified mica powder and 6 parts of silicon carbide powder are mixed, and the activator is sprayed under the stirring of 2000 rpm, and stirred and mixed for 50 min under the stirring of 2000 rpm;85 DEG C is dried to constant weight, and is passed through 250 mesh screen to obtain activated filler.

[0042] The preparation method of the boron-modified mica powder comprises the following steps: dispersing mica powder in 6 times the mass of deionized water according to the mass ratio of mica powder:boric acid = 100:12, shearing and dispersing for 40 min at 5000 r / min to obtain a mica powder dispersion liquid; dissolving boric acid in 5 times the mass of warm water at 60 DEG C to obtain a boric acid solution; under stirring at 400 rpm, the boric acid solution is added dropwise into the mica powder dispersion liquid, heated to 85 DEG C, and stirred at 400 rpm for 2 h; spray drying is performed to obtain a composite powder, which is sintered under nitrogen protection, heated to 350 DEG C at a rate of 3 DEG C / min, kept for 40 min, continuously heated to 550 DEG C at a rate of 3 DEG C / min, and kept for 3 h; and cooling to obtain the boron-modified mica powder.

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

[0044] In the above examples, the source of phenyltrimethoxysilane is Shandong Gaotai Chemical Technology Co., Ltd., model OFS-6040. The source of tetraisopropyl titanate is Wuhan Jixin Yibang Biological Technology Co., Ltd. The source of acetylacetone is Shandong Yukang Chemical Co., Ltd. The source of tetramethyltetraphenyl trisiloxane is Jinjinle Chemical Co., Ltd. The source of hydroxyl-terminated methyl-3,3,3-trifluoropropyl siloxane and polysiloxane is Zhengzhou Alpha Chemical Co., Ltd. The source of bisphenol A type epoxy resin is Guangzhou Deweise New Material Co., Ltd., produced by Balin Petrochemical, model E-44. The source of acetylacetone aluminum is Jinan Zhiheng Chihuan Chemical Technology Co., Ltd. The source of titanate coupling agent is Guangdong Wengjiang Chemical Reagent Co., Ltd., model NDZ-201. The source of calcined kaolin is Zhejiang Changxing Zhonghong New Material Co., Ltd., 1250 mesh grade. The source of mica powder is Lingshou County Baofeng Mica Processing Co., Ltd. The source of boric acid is Henan Tuoyuan Chemical Product Co., Ltd. The source of silicon carbide powder is Qinghe County Benyu Metal Material Co., Ltd., ground spherical silicon carbide powder. The BYK-163 dispersant is BYK 163 dispersant. The source of polyether-modified siloxane is Guangdong Fangzhou Chemical Industry Co., Ltd., model AC-408. The source of propylene glycol methyl ether acetate is Shandong Juxing Chemical Co., Ltd.

[0045] Comparative Example 1

[0046] The difference from Example 1 is that the addition amount of tetramethyltetraphenyl trisiloxane is changed to 5 parts.

[0047] Comparative Example 2

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

[0049] Comparative Example 3

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

[0051] Comparative Example 4

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

[0053] Comparative Example 5

[0054] The difference from Example 1 is that the amount of tetramethyltetraphenyl trisiloxane is changed to 5 parts and the amount of temperature-resistant modifier is changed to 30 parts.

[0055] Comparative Example 6

[0056] The difference from Example 1 is that the amount of tetramethyltetraphenyl trisiloxane is changed to 16 parts and the amount of temperature-resistant modifier is changed to 10 parts.

[0057] Comparative Example 7

[0058] The difference from Example 1 is that the boron-modified mica powder is replaced by 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 material liquid A, the material liquid B and the material liquid C, the material liquid D is directly added dropwise, the dropwise time is 40 min, the system temperature is controlled below 80℃, after the dropwise is completed, the temperature is increased to 120℃ at a rate of 1℃ / min, the stirring is reacted at 300 rpm for 1.5 h, the water is removed by distillation under reduced pressure, and the water distillation liquid is stopped at 4.2 mL / h, to obtain 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: sandblasted rusted Q235 steel plate (150x70x1mm); curing procedure: heating to 80℃ for 1h, then heating to 120℃ for 1h, then heating to 200℃ for 1h; coating thickness: dry film thickness 80±2μm.

[0065] II. Test items:

[0066] 1. Temperature resistance limit (GB / T1735): Put the sample into a high temperature furnace, and observe the surface state of the coating every 10℃ from 450℃. Record the temperature when the coating shows obvious damage such as blistering, cracking, peeling, etc. The temperature is the temperature resistance limit.

[0067] 2. Thermal weight loss rate (600℃ / 24h, GB / T27761): Weigh the initial mass m1 of the sample, put the sample into a high temperature furnace which has been heated to 600℃, and keep it for 24h. Then take it out, cool it to room temperature in a dryer, weigh it again m2, and calculate the thermal weight loss rate.

[0068] 3. Adhesion (cross-hatch method, GB / T9286):

[0069] Use a cross-hatch knife to draw a 1mm x 1mm square on the surface of the coating, and draw the square to the substrate surface. Paste 3M tape (model 600) tightly in the square area, roll it back and forth 5 times with a rubber roller at a pressure of 5N / cm, then tear off the tape at a 90° angle. Observe the square area with a microscope, and rate the adhesion.

[0070]

[0071] 4. Impact resistance (falling ball impact, GB / T1732): Fix the sample horizontally on the test table of the impact tester, and let a 1kg steel ball fall freely from different heights (5cm increments each time) to impact the center of the coating surface. Impact 3 times at each height. Observe whether there are cracks, peeling, and other damage on the coating surface, and record the maximum height without damage as the impact resistance value.

[0072] 5. Salt spray resistance (1000h, GB / T1771): Put the sample into a salt spray test chamber, and use a 5wt% NaCl solution in the test chamber. Control the pH value of the solution at 6.8, and keep the temperature at 35℃. The salt spray deposition amount is 2mL / (80cm 2 h). Observe the time when the coating surface shows corrosion (observe 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, and make sure the solution volume covers the sample completely. Keep it in a constant temperature environment at 25℃ for 168h. Take out the sample, rinse it with clean water, dry it, weigh it again m2, and calculate the acid resistance weight loss rate.

[0074] 7. Alkali resistance (10% NaOH / 168h): The initial mass of the sample is weighed as ml, and the sample is completely immersed in a 10% NaOH solution, the volume of the solution is ensured to completely cover the sample, and it is kept at 25°C for 168h. The sample is taken out, washed with clean water, dried and weighed again as m2, and the alkali weight loss rate is calculated.

[0075] Each experiment has 3 parallel samples, and the average value is taken. The test results are shown in Table 1 below:

[0076] Table 1 Test Results

[0077]

[0078] From the above results, it can be seen that the synergistic effect of the formulation proportions of Examples 1 to 3 has good modification effect, effectively improves the high temperature stability, and can well balance other mechanical properties and corrosion resistance.

[0079] In Comparative Example 1, the addition amount of tetramethyltetraphenyl trisiloxane is reduced to 5 parts. Tetramethyltetraphenyl trisiloxane can participate in the crosslinking reaction of the coating matrix resin to form a more stable three-dimensional network structure. After the addition amount is reduced, the Si-O-Si crosslinking network density is reduced, and the interaction between the molecular chains is weakened. In a high temperature environment, the molecular chains are more prone to thermal motion and rupture, resulting in a decrease in temperature resistance limit and an increase in thermal weight loss rate. The imperfect crosslinking network makes the adhesion between the coating and the substrate worse, and the adhesion is reduced; at the same time, the ability of the coating to resist external impact is reduced. In a salt spray, acid and alkali environment, corrosive media and water vapor can easily penetrate into the coating, causing corrosion and damage to the coating.

[0080] In Comparative Example 2, the addition amount of tetramethyltetraphenyl trisiloxane is increased to 20 parts, which increases the crosslinking points to a certain extent and improves the temperature resistance of the three-dimensional Si-O-Si network. However, too much tetramethyltetraphenyl trisiloxane will greatly increase the viscosity of the coating system, and the crosslinking is excessive, making it difficult for the solvent to volatilize during film formation, and easy to form pores and other defects in the coating, affecting the density of the coating. Excessive causes a certain phase separation due to the difference in polarity with the epoxy, stress concentration occurs due to excessive aggregation, and impact is prone to cracking; the film forming quality is poor, the impact resistance and corrosion resistance are reduced, and it is difficult to better balance the high temperature resistance, impact resistance and corrosion resistance.

[0081] In Comparative Example 3, the amount of temperature-resistant modifier is reduced to 10 parts. The hydroxyl-terminated methyl-3,3,3-trifluoropropyl (siloxane and polysiloxane) in the temperature-resistant modifier can effectively improve the high-temperature resistance and chemical stability of the coating. When the amount is insufficient, the hydroxyl-terminated fluorosilicon segment is insufficient, and the coating cannot form a stable molecular structure at high temperature to resist thermal decomposition, resulting in a decrease in temperature resistance. The lack of fluorosilicon chain weakens the resistance to chemical media, and the decrease in chemical stability also leads to a more likely chemical reaction in acidic and alkaline environments, resulting in a decrease in corrosion resistance; at the same time, the protection ability of the substrate decreases.

[0082] In Comparative Example 4, the amount of temperature-resistant modifier is increased to 35 parts. Excessive temperature-resistant modifier will make the molecular chain in the coating system too long and entangled, resulting in limited movement of the molecular chain, and it is difficult to form a uniform and ordered structure during film formation. It is difficult for the solvent to volatilize during film formation, and pores and other defects are easily formed inside the coating, affecting the density of the coating. Excessive fluorosilicon segments migrate to the surface of the coating, reducing chemical bonding with the substrate, and the compatibility of the fluorosilicon phase and the epoxy phase becomes poor, resulting in stress concentration. Although the intermolecular force is increased, the internal stress is also increased, and the release of internal stress at high temperature causes the coating to have small cracks, affecting the high-temperature resistance. The stress concentration area also becomes a penetration channel for corrosive media and water vapor, reducing the protective performance of the coating.

[0083] In Comparative Example 5, the amount of tetramethyltetraphenyltrisiloxane is reduced to 5 parts and the amount of temperature-resistant modifier is increased to 30 parts. The unreasonable change in the amount of both results in the loss of synergistic effect, and low crosslinking degree and high fluorosilicon content lead to loose structure, which seriously hinders the construction of the crosslinked network and the formation of thermal stable structure of the coating system. The dual influence of insufficient crosslinking and excessive entanglement of molecular chains leads to easy decomposition and destruction of the coating at high temperature. The mechanical properties and protective performance are also sharply decreased.

[0084] In Comparative Example 6, the amount of tetramethyltetraphenyltrisiloxane is increased to 16 parts and the amount of temperature-resistant modifier is reduced to 10 parts. This combination results in poor film formation quality of the coating system due to excessive tetramethyltetraphenyltrisiloxane, and a decrease in thermal stability due to insufficient temperature-resistant modifier. High crosslinking degree limits the movement of segments, and residual stress causes microcracks, and the coating is prone to thermal degradation and structural damage at high temperature. The poor film formation quality and thermal stability also seriously affect the adhesion and corrosion resistance of the coating.

[0085] In Comparative Example 7, the boron-modified mica powder is replaced by mica powder. The boron-modified mica powder enhances the compatibility and interfacial bonding force with the coating matrix through modification by boron element, and its special layered structure can effectively block the penetration of corrosive media. The ordinary mica powder is mainly physically adsorbed with the coating matrix, with weak bonding force and unable to play an effective shielding role. The ordinary mica powder does not generate borosilicate glass phase, and has no melting hole sealing effect at high temperature; at high temperature, the internal coating lacks effective support and stable structure, and the temperature resistance decreases; the filler-resin interface has weak bonding, and high-temperature components accelerate decomposition. In various corrosive environments, corrosive media can easily penetrate to the substrate surface. Poor interfacial compatibility leads to uneven dispersion, unstable mechanical properties, and poor performance.

[0086] In Comparative Example 8, the preparation method of the modified matrix resin is changed by changing the feeding order and reaction conditions, so that the reaction between raw materials is not sufficient, and there is no stepwise grafting, resulting in partial phase separation. The original stepwise reaction and specific temperature and time control are to make the raw materials fully hydrolyze, polycondensate and other reactions to form stable molecular structure and good crosslinking network. After the change, the connection and crosslinking degree of the molecular chain are insufficient, the stability of the molecular structure is reduced, and the overall performance is decreased.

[0087] In Comparative Example 9, no titanate coupling agent is added, and the filler is not activated. The titanate coupling agent can form a chemical bond on the surface of the filler, one end reacts with the active groups on the surface of the filler, and the other end reacts with the coating matrix resin, thereby enhancing the interfacial bonding force between the filler and the matrix. The unactivated filler and the matrix rely on weak physical adsorption, and the bonding is not firm, the porosity of the coating is increased, and the uncoupled filler acts as a stress concentration point, causing crack propagation. Under the action of high temperature, corrosion and other environments, the filler is easily detached from the coating, damaging the integrity of the coating.

Claims

1. A high temperature resistant industrial coating, characterized in that: The coating comprises the following raw materials in parts by mass: 100 to 110 parts of phenyltrimethoxysilane, 30 to 35 parts of tetraisopropyl titanate, 0.4 to 0.6 parts of acetylacetone, 10 to 12 parts of tetramethyltetraphenyl trisiloxane, 20 to 25 parts of a heat-resistant modifier, 65 to 70 parts of bisphenol A epoxy resin, 2 to 3 parts of aluminum acetylacetonate, 1 to 2 parts of a titanate coupling agent, 40 to 42 parts of calcined kaolin, 25 to 28 parts of boron-modified mica powder, 4 to 6 parts of silicon carbide powder, 0.2 to 0.3 parts of BYK-163 dispersant, and 0.8 to 1.0 parts of a polyether-modified siloxane; the solvent is propylene glycol methyl ether acetate; The phenyltrimethoxysilane, tetraisopropyl titanate, acetylacetone, tetramethyltetraphenyl trisiloxane and a heat-resistant modifier are reacted and then reacted with bisphenol A epoxy resin and aluminum acetylacetonate 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 a titanate coupling agent to obtain an activated filler.

2. A high temperature resistant industrial coating according to claim 1, characterized in that: The preparation method of the modified matrix resin comprises: mixing 100 to 110 parts of phenyltrimethoxysilane and 150 to 180 parts of deionized water to obtain a feed liquid A; mixing 30 to 35 parts of tetraisopropyl titanate, 0.4 to 0.6 parts of acetylacetone and 20 to 25 parts of propylene glycol methyl ether acetate to obtain a feed liquid B; mixing 10 to 12 parts of tetramethyl tetraphenyl trisiloxane, 20 to 25 parts of a heat-resistant modifier and 70 to 80 parts of propylene glycol methyl ether acetate to obtain a feed liquid B. ether acetate to obtain feed liquid C; 65 parts to 70 parts of bisphenol A type epoxy resin and 2 parts to 3 parts of aluminum acetylacetonate are mixed to obtain feed liquid D; under nitrogen protection, feed liquid A, feed liquid B and feed liquid C are mixed, stirred and reacted at 60°C to 65°C, cooled to room temperature, and then feed liquid D is added dropwise under stirring while controlling the system temperature below 80°C. After the addition is completed, the temperature is raised to 120°C to 125°C and stirred for reaction, and water is removed by distillation under reduced pressure to obtain a modified base resin.

3. A high temperature resistant industrial coating according to claim 2, characterized in that: The stirring speed is 300 rpm to 400 rpm; the stirring reaction time is 1.5 h to 2 h; the dropwise addition time is 40 min to 50 min; the heating rate is 1°C / min to 1.5°C / min; and the reduced pressure distillation is stopped when the water distillate is less than 5 mL / h.

4. A high temperature resistant industrial coating according to claim 1, characterized in that: The preparation method of the activated filler comprises: mixing 1 to 2 parts of a 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 into the mixture while stirring, and stirring and mixing; and drying and sieving to obtain the activated filler.

5. A high temperature resistant industrial coating according to claim 4, characterized in that: 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° C. to 85° C. to a constant weight; and the sieving is carried out through a 200-250 mesh sieve.

6. A high temperature resistant industrial coating according to claim 1 or 4, characterized in that: The calcined kaolin passes 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.

7. A high temperature resistant industrial coating according to claim 1 or 4, characterized in that: The preparation method of the boron-modified mica powder comprises: dispersing mica powder in deionized water according to a 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; dripping the boric acid solution into the mica powder dispersion under stirring, heating to 80°C-85°C, and stirring for 1.5 hours-2 hours; spray drying to obtain a composite powder, sintering, and cooling to obtain the boron-modified mica powder.

8. A high temperature resistant industrial coating according to claim 7, characterized in that: The amount of deionized water is 4 to 6 times the mass of the mica powder; the dispersion is sheared at 4000 r / min to 5000 r / min for 30 to 40 minutes; the temperature of the warm water is 55°C to 60°C, 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°C to 350°C, keeping warm for 30 to 40 minutes, continuing to heat to 500 to 550°C, and keeping warm for 2 to 3 hours; the average heating rate is 2°C / min to 3°C / min.

9. The method for producing a high temperature resistant industrial coating according to claim 1, characterized in that: The method comprises the following steps: adding BYK-163 dispersant, polyether modified silicone and propylene glycol methyl ether acetate to a modified base resin at a temperature below 35° C., stirring, then adding activated filler, intermittently grinding, and vacuum defoaming to obtain a coating.

10. The method for manufacturing a high temperature resistant industrial coating according to claim 9, characterized in that: The stirring is performed at 200 rpm to 300 rpm for 15 to 20 minutes; the intermittent grinding is performed at 1800 rpm to 2000 rpm to a fineness of ≤20 μm; and the temperature of the intermittent grinding is controlled below 35° C.

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