High-performance organic silicon high-temperature-resistant coating and preparation method thereof

Abstract

The invention relates to the technical field of organic silicon high-temperature-resistant coatings, and discloses a high-performance organic silicon high-temperature-resistant coating and a preparation method thereof. The high-performance organic silicon high-temperature-resistant coating comprises the following components in parts by weight: 40-50 parts of modified organic silicon resin, 0.1-1 part of a dispersing agent, 0.1-1 part of a defoaming agent, 0.4-1 part of an anti-settling agent, 30-40 parts of modified filler, 8-10 parts of a solvent and 8-10 parts of a curing agent, wherein the modified filler is prepared by compounding diamond powder, silicon carbide, mica powder, copper chrome black and low-melting-point glass powder. Through selection and modification of the resin and the filler, the prepared high-performance organic silicon high-temperature-resistant coating has excellent performances of high temperature resistance, acid resistance, wear resistance and the like before and after the high temperature of 600 DEG C.

Description

Technical Field

[0001] The present invention relates to the technical field of organosilicon high temperature resistant coatings, and in particular to a high performance organosilicon high temperature resistant coating and a preparation method thereof. Background Art

[0002] High temperature resistant coatings can keep the paint film from cracking and delamination under the use temperature environment above 200℃, maintain certain mechanical properties, and can operate the protected object normally under the use environment. For example, in the application of high temperature chimneys and high temperature chemical exhaust pipes, not only the high temperature will corrode the metal substrate during operation, but also the flue gas and chemical exhaust gas contain dust particles and certain acidic gases. The flow of dust particles will wear the inner wall, and the chemical substances will corrode the substrate. Usually, high temperature resistant coatings are applied for protection.

[0003] Silicone high temperature resistant coating contains some organic groups, has good film toughness and excellent construction performance with low substrate processing requirements, which makes silicone high temperature resistant coating play an important role in high temperature protection. The current research on high temperature resistant coating mainly focuses on mechanical properties before high temperature and chemical resistance of high temperature resistant coating. Among them, patent CN201510731155.7 is a heat-resistant and acid-alkali-resistant coating and its preparation method. The product has a high temperature resistance of 400-500℃ and has the performance of resistant to 5% sodium hydroxide and 15% acetic acid for 40h without abnormality. However, the system has limited wear resistance without filler as a skeleton support, and the acid and alkali resistance performance has not been tested after high temperature, which cannot truly reflect the actual application scenario of the protected object; patent CN201710588564.5 is a wear-resistant and high temperature resistant coating with high adhesion. The product has the performance of resistant to 900℃ high temperature for 15min and certain wear resistance. Adding a certain amount of aluminum silver paste in the formula is not good for the acid resistance of the coating. Therefore, there is currently basically no high-performance silicone high-temperature resistant coating that is resistant to high temperatures, acid and wear at 600°C before and after high temperatures.

[0004] Therefore, there is an urgent need for a high-performance organosilicon high-temperature resistant coating and a preparation method thereof to solve the above problems. Summary of the invention

[0005] Based on the above, the purpose of the present invention is to provide a high-performance organosilicon high-temperature resistant coating and a preparation method thereof, which has excellent high-temperature resistance, acid resistance and wear resistance in an environment of 600°C.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A high-performance organosilicon high-temperature resistant coating comprises the following components in parts by weight:

[0008] 40-50 parts of modified silicone resin, 0.1-1 parts of dispersant, 0.1-1 parts of defoamer, 0.4-1 parts of anti-settling agent, 30-40 parts of modified filler, 8-10 parts of solvent, 8-10 parts of curing agent;

[0009] The modified filler is prepared by compounding diamond powder, silicon carbide, mica powder, copper chromium black and low-melting-point glass powder.

[0010] As a preferred embodiment of a high-performance organosilicon high temperature resistant coating, the weight ratio of the diamond powder, the silicon carbide, the mica powder, the copper chrome black and the low melting point glass powder is (1-5): (5-10): (5-15): (5-10): (10-30).

[0011] As a preferred solution for a high-performance organosilicon high-temperature resistant coating, the preparation method of the modified filler comprises:

[0012] Diamond powder, silicon carbide, mica powder, copper chromium black, and low-melting-point glass powder are baked in a muffle furnace at 550-600°C for 2-3 hours according to the proportion, ball-milled after cooling, and mixed and ground for 1-1.5 hours to obtain a uniform ball-milled filler;

[0013] Dissolve 2-10% of the total reactant mass of KH-550 silane coupling agent in ethanol, disperse at 600-800 r / min for 5-10 min, add the ball-milled filler while dispersing, heat to 70-80° C. after adding the ball-milled filler, and disperse for 80-90 min; finally, age, centrifuge and dry to obtain the modified filler.

[0014] As a preferred solution for high-performance organosilicon high-temperature resistant coating, the diamond powder has a particle size of 10-20 microns; the silicon carbide has a particle size of 10-15 microns; the copper chrome black has a particle size of 3-5 microns; the mica powder has a particle size of 10-15 microns; the low-melting point glass powder is a compound of YB-D45 and YB-D50, and the ratio is (2-2.5):1.

[0015] As a preferred solution of a high-performance organosilicon high temperature resistant coating, the modified organosilicon resin includes an acrylic acid modified organosilicon resin; and the preparation method of the acrylic acid modified organosilicon resin includes:

[0016] Weigh 100-200 parts of deionized water and 15-20 parts of acetone by mass, mix well, adjust the pH value to 3.8-4.2 with hydrochloric acid, and put into a container;

[0017] 50-100 parts of silane monomer are added dropwise to the container, and then the temperature is raised to 65-70° C. for hydrolysis reaction for 3-4 hours;

[0018] The reaction liquid after the hydrolysis reaction is washed with water until it becomes neutral to obtain a hydrolyzed prepolymer;

[0019] The hydrolyzed prepolymer is heated to 100-110° C. for reaction for 2-2.5 hours, and xylene is added to adjust the solid content to 47-53%, thereby obtaining a silicone resin;

[0020] The acrylic monomer, double bond silane and initiator are mixed and stirred to obtain an acrylic acid mixed liquid;

[0021] The organic silicone resin and the acrylic acid mixed solution are heated to 60-80° C. in a mass ratio of 100:(5-10) and reacted for 4-6 hours to obtain a modified organic silicone resin.

[0022] As a preferred solution for a high-performance organosilicon high-temperature resistant coating, the silane monomer is prepared by compounding dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane, and the mass ratio of the dimethyldiethoxysilane, the diphenyldimethoxysilane and the phenyltrimethoxysilane is (2-10):(1-10):(1-10).

[0023] As a preferred embodiment of a high-performance organosilicon high temperature resistant coating, the mass ratio of the acrylic monomer, the double bond silane and the initiator is (8-10): (0.8-1.2): (0.05-0.5);

[0024] The acrylic monomer includes one or more of methyl acrylate, n-butyl acrylate, hydroxyethyl methacrylate, isobornyl acrylate, ethylene glycol diacrylate, and ethoxylated bisphenol A diacrylate; the double-bond silane includes one or two of vinyl dimethyl siloxane and methyl vinyl dimethoxy silane; and the initiator includes one or more of dibenzoyl peroxide, isopropylbenzene hydroperoxide, and azobisisoheptonitrile.

[0025] As a preferred solution for a high-performance organosilicon high-temperature resistant coating, the dispersant is a high molecular weight block copolymer containing pigment affinity groups, specifically including one or two of BYK-163 and BYK-203; the defoamer is a polysiloxane solution, specifically including one or two of BYK-066N and TEGO-900; the anti-settling agent includes one or more of fumed silica, organic bentonite, and polyamide wax slurry.

[0026] As a preferred solution for a high-performance organosilicon high-temperature resistant coating, the solvent includes one or more of xylene, trimethylolbenzene, ethyl acetate and propylene glycol methyl ether acetate; and the curing agent includes an isocyanate curing agent.

[0027] A method for preparing a high-performance organosilicon high-temperature resistant coating, based on any of the above-mentioned high-performance organosilicon high-temperature resistant coatings, the method for preparing the high-performance organosilicon high-temperature resistant coating comprises the following steps:

[0028] Add modified silicone resin, dispersant, defoamer, anti-settling agent in proportion, and disperse at high speed for 20-30 minutes to fully activate the anti-settling agent. Then add modified filler in proportion and disperse at high speed for 60-90 minutes to evenly disperse the powder. Add solvent to adjust the viscosity, and finally add curing agent to obtain high-performance silicone high-temperature resistant coating.

[0029] The beneficial effects of the present invention are:

[0030] The present invention proposes to use organic silicon resin modification and filler modification to improve the crosslinking degree and adhesion of the paint film, thereby improving the wear and acid resistance of the paint film before high temperature; the diamond powder with the highest hardness and the largest particle size in the filler is used as the frame of the paint film, and the impact of external particles is resisted in the outer layer to improve the wear resistance. Silicon carbide, mica, and glass powder with high hardness and relatively small particle size are used to fill the pores, which maximizes the density of the paint film and improves the wear and acid resistance. The large-particle diamond is supported on the surface of the paint film, which can resist the impact of particles and improve the wear resistance of other components; the low-melting point glass powder compounding technology is used to act as a hard filler when the melting temperature of the low-melting point glass powder is not reached, and act as a film-forming material at the melting temperature. The compounding of glass powders with different melting points ensures the strength of the paint film at different temperatures and does not flow. The present invention also proposes a curing agent compounding technology, using a curing agent with a certain elasticity to reduce the stress of the resin during the organic to inorganic conversion process, avoid high-temperature cracking and delamination, and add a rigid curing agent to increase the drying speed and crosslinking degree. Therefore, high-performance silicone high-temperature resistant coatings have excellent properties such as high-temperature resistance, acid resistance, and wear resistance before and after 600°C high temperature. DETAILED DESCRIPTION

[0031] For ease of understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Unless otherwise defined, all technical and scientific terms used in the present invention belong to the technical field of the present invention.

[0032] This embodiment provides a method for preparing a high-performance organosilicon high-temperature resistant coating, comprising the following steps:

[0033] Add 40-50 parts of modified silicone resin, 0.1-1 parts of dispersant, 0.1-1 parts of defoamer, 0.4-1 parts of anti-settling agent by weight, and disperse at high speed for 20-30 minutes to fully activate the anti-settling agent, then add 30-40 parts of modified filler and disperse at high speed for 60-90 minutes, add 8-10 parts of solvent to adjust the viscosity, and finally add 8-10 parts of curing agent to obtain a high-performance silicone high-temperature resistant coating.

[0034] Specifically, the dispersant is a high molecular weight block copolymer containing pigment affinity groups, specifically including one or two of BYK-163 and BYK-203, preferably BYK-163;

[0035] The defoamer is a polysiloxane solution, specifically including one or both of BYK-066N and TEGO-900, preferably TEGO-900;

[0036] The anti-settling agent includes one or more of fumed silica, organic bentonite, and polyamide wax slurry; preferably, fumed silica.

[0037] The solvent includes one or more of xylene, trimethylbenzene, ethyl acetate and propylene glycol methyl ether acetate; the preferred solvent is xylene:propylene glycol methyl ether acetate = 2:1.

[0038] The curing agent includes an isocyanate curing agent, preferably a compound of Bayer 3800 and Bayer 3390, with a ratio of 1: 1. Bayer 3800 curing agent has certain flexibility, but the reaction speed is slightly slow. The compound of the two takes into account both construction performance and mechanical properties.

[0039] Specifically, the modified filler is prepared by compounding diamond powder, silicon carbide, mica powder, copper chrome black, and low-melting-point glass powder, and has high temperature stability, acid resistance, and wear resistance. The preparation method of the modified filler includes:

[0040] (1) baking diamond powder, silicon carbide, mica powder, copper chromium black, and low-melting point glass powder in a muffle furnace at 550-600° C. for 2-3 hours according to a ratio; this is used to remove water adsorbed on the surface of the filler and part of the crystal water to improve the modification efficiency and avoid agglomeration of the filler in subsequent steps;

[0041] (2) After cooling, ball milling is performed, and mixed grinding is performed for 1-1.5 hours to obtain a uniform ball-milled filler;

[0042] (3) Dissolve 2-10% of the total reactant mass of KH-550 silane coupling agent in ethanol, disperse at 600-800 r / min for 5-10 min, add ball-milled filler while dispersing, and after the ball-milled filler is added, heat to 70-80° C. and disperse for 80-90 min; finally, age, centrifuge, and dry to obtain the modified filler.

[0043] Specifically, the weight ratio of diamond powder, silicon carbide, mica powder, copper chrome black and low-melting point glass powder is (1-5): (5-10): (5-15): (5-10): (10-30), preferably diamond powder: silicon carbide: mica powder: copper chrome black: low-melting point glass powder = 2:8:10:10:15.

[0044] More specifically, the particle size of diamond powder is 10-20 microns. Diamond powder has high hardness and good wear resistance. It can be widely used in cutting, grinding, drilling, and polishing. It is rarely reported to be used in coatings. Generally, the larger the amount of diamond powder added, the better the wear resistance. At the same time, the price will be high and not cost-effective.

[0045] The particle size of silicon carbide is 10-15 microns, and black silicon carbide is preferred; the particle size of copper chrome black is 3-5 microns; the particle size of mica powder is 10-15 microns, and GA-5 is preferred;

[0046] The low melting point glass powder is a compound of YB-D45 and YB-D50, with a ratio of (2-2.5):1, preferably 2:1, wherein the melting temperature of YB-D45 is 450-580°C, and the melting temperature of YB-D50 is 480-650°C.

[0047] Specifically, the modified silicone resin includes acrylic modified silicone resin; in addition, the modified silicone resin also includes methylphenyl silicone resin, methyl silicone resin, epoxy modified silicone resin and fluorine modified silicone, all of which can be used as modified silicone resins, and their preparation methods are not specifically described here.

[0048] The preparation method of acrylic acid modified silicone resin comprises:

[0049] (1) Weigh 100-200 parts of deionized water and 15-20 parts of acetone by mass, mix them evenly, adjust the pH value to 3.8-4.2 with hydrochloric acid, and transfer them into a three-necked flask. Preferably, 100 parts of deionized water and 18 parts of acetone are used and mixed evenly;

[0050] (2) adding 50-100 parts of silane monomer dropwise into the container, and then heating to 65-70° C. for hydrolysis reaction for 3-4 hours;

[0051] (3) washing the reaction solution after the hydrolysis reaction with water until it becomes neutral to obtain a hydrolyzed prepolymer;

[0052] (4) heating the hydrolyzed prepolymer to 100-110° C. for reaction for 2-2.5 hours, and adding xylene to adjust the solid content to 47-53%, thereby obtaining an organosilicon resin;

[0053] (5) mixing an acrylic monomer, a double bond silane and an initiator and stirring to obtain an acrylic acid mixture;

[0054] (6) Heat the mixed solution of silicone resin and acrylic acid to 60-80° C. in a mass ratio of 100:(5-10) and react for 4-6 hours to obtain a modified silicone resin.

[0055] Specifically, the silane monomer is prepared by compounding dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane, and the mass ratio of dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane is (2-10): (1-10): (1-10).

[0056] Specifically, the mass ratio of acrylic monomer, double bond silane and initiator is (8-10): (0.8-1.2): (0.05-0.5); wherein the acrylic monomer includes acrylic monofunctional monomer and acrylic difunctional monomer, and the mass ratio of the two is not required; the acrylic monofunctional monomer includes one or more of methyl acrylate, n-butyl acrylate, hydroxyethyl methacrylate, and isobornyl acrylate; the acrylic difunctional monomer includes one or two of ethylene glycol diacrylate and ethoxylated bisphenol A diacrylate; the double bond silane includes one or two of vinyl dimethyl siloxane and methyl vinyl dimethoxy silane; the initiator includes one or more of dibenzoyl peroxide, isopropylbenzene hydroperoxide, and azobisisoheptonitrile.

[0057] The present invention will be further described below by means of specific examples.

[0058] Example 1

[0059] A high-performance organosilicon high-temperature resistant coating comprises the following components by weight: 45 parts of modified organosilicon resin, 1 part of dispersant, 0.6 parts of defoaming agent, 0.4 parts of anti-settling agent, 35 parts of modified filler, 9 parts of solvent and 9 parts of curing agent.

[0060] The dispersant is BYK-163, the defoamer is TEGO-900, the anti-settling agent is fumed silica, the solvent is a mixture of xylene and propylene glycol methyl ether acetate in a ratio of 2:1, and the curing agent is a mixture of Bayer 3800 and Bayer 3390 in a ratio of 1:1.

[0061] The modified silicone resin is an acrylic acid modified silicone resin, and the preparation method of the acrylic acid modified silicone resin comprises:

[0062] (1) Weigh 100 parts of deionized water and 18 parts of acetone by mass, mix them evenly, adjust the pH value to about 4 with hydrochloric acid, and transfer them into a three-necked flask;

[0063] (2) 100 parts of silane monomer are weighed. The silane monomer is prepared by compounding dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane in a mass ratio of 2:5:3. They are slowly added into a three-necked flask respectively. After the addition is completed, the temperature is raised to 70°C and the hydrolysis reaction is carried out for 4 hours. Among them, the ratio of the silane monomer compounded by dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane can also be set to 2:1:1, 2:10:10, 2:1:10, 2:10:1, 10:1:1, 10:10:1, 10:1:10, 10:10:10, 6:5:6, which is determined according to the actual situation.

[0064] (3) washing the reaction solution after the hydrolysis reaction with water until it becomes neutral to obtain a hydrolyzed prepolymer;

[0065] (4) heating the hydrolyzed prepolymer to 110° C. for reaction for 2.5 hours, and adding xylene to adjust the solid content to about 50%, thereby obtaining an organosilicon resin;

[0066] (5) The acrylic acid monomer, the double bond silane and the initiator are mixed and stirred in a mass ratio of 8:1.2:0.05 to obtain an acrylic acid mixed solution; wherein the ratio of the acrylic acid monomer, the double bond silane and the initiator can also be set to 8:0.8:0.05, 8:0.8:0.5, 8:1.2:0.05, 8:1.2:0.5, 10:0.8:0.05, 10:0.8:0.5, 10:1.2:0.05, 10:1.2:0.5, 9:1:0.3, which is determined according to actual conditions.

[0067] The acrylic monomer is n-butyl acrylate, the double-bond silane is methylvinyl dimethoxysilane, and the initiator is cumene hydroperoxide;

[0068] (6) The organic silicone resin and the acrylic acid mixture are heated to 70° C. in a mass ratio of 100:5 and reacted for 5 hours to obtain a modified organic silicone resin.

[0069] The preparation method of the modified filler comprises:

[0070] (1) Diamond powder, silicon carbide, mica powder, copper chromium black, and low-melting point glass powder are baked in a muffle furnace at a mass ratio of 2:8:10:10:15 for 3 hours; wherein the mass ratio of diamond powder, silicon carbide, mica powder, copper chromium black, and low-melting point glass powder can also be set to 1:5:5:5:10, 1:5:5:5:30, 1:5:5:10:10, 1:5:5:10:30, 1:5:15:5:10, 1:5:15:5:30, 1:5:15:10:10, 1:5:15:10:30, 1:10:5:5:10, 1:10:5:5:30, 1:10:5:5:10:10, 1:10:5:5:30, 1:10:5:10:10, 1:10:5:10:30, 1:10:15:5:10, 1:10:5:10:30, 1:10:15:5:10, 1:10: 15:5:30、1:10:15:10:10、1:10:15:10:30、5:5:5:5:10、5:5:5:5:30、5:5:5:10:10、5:5:5:10:30、5:5:15:5:10、5:5:15:5:30、5:5:15:10:10、5:5:15:10: 30. 5:10:5:5:10, 5:10:5:5:30, 5:10:5:10:10, 5:10:5:10:30, 5:10:15:5:10, 5:10:15:5:30, 5:10:15:10:10, 5:10:15:10:30, 3:8:10:8:20. The specific time will be determined according to the actual situation.

[0071] In addition, the diamond powder has a particle size of 10 microns, the silicon carbide is black silicon carbide with a particle size of 10 microns, and the copper chromium black has a particle size of 3 microns; the mica powder is Grey GA-5 with a particle size of 10 microns; the low-melting point glass powder is a compound of YB-D45 and YB-D50 with a ratio of 2:1, of which the melting temperature of YB-D45 is 580°C, and the melting temperature of YB-D50 is 650°C.

[0072] (2) ball milling after cooling, and mixing and grinding for 1 hour to obtain a uniform ball-milled filler;

[0073] (3) 2% KH-550 silane coupling agent was dissolved in ethanol and dispersed at 700 r / min for 10 min. The ball-milled filler was added during dispersion. After the ball-milled filler was added, the temperature was raised to 80° C. and then dispersed for 90 min. Finally, the modified filler was obtained by aging, centrifugation and drying.

[0074] A method for preparing a high-performance organosilicon high-temperature resistant coating comprises:

[0075] 45 parts of modified silicone resin, 1 part of dispersant, 0.6 parts of defoaming agent, 0.4 parts of anti-settling agent were added by weight and dispersed at high speed for 25 minutes to fully activate the anti-settling agent. Then 35 parts of modified filler were added and dispersed at high speed for 90 minutes. 9 parts of solvent were added to adjust the viscosity. Finally, 9 parts of curing agent were added to obtain a high-performance silicone high-temperature resistant coating.

[0076] Example 2

[0077] A high-performance organosilicon high-temperature resistant coating comprises the following components by weight: 40 parts of modified organosilicon resin, 0.9 parts of dispersant, 0.1 parts of defoaming agent, 1 part of anti-settling agent, 40 parts of modified filler, 10 parts of solvent and 8 parts of curing agent.

[0078] The dispersant is BYK-203, the defoamer is BYK-066N, the anti-settling agent is organic bentonite, the solvent is ethyl acetate, and the curing agent is a mixture of Bayer 3800 and Bayer 3390, with a ratio of 1:1.

[0079] The modified silicone resin is an acrylic acid modified silicone resin, and the preparation method of the acrylic acid modified silicone resin comprises:

[0080] (1) Weigh 150 parts of deionized water and 20 parts of acetone by mass, mix them evenly, adjust the pH value to about 4 with hydrochloric acid, and transfer them into a three-necked flask;

[0081] (2) Weigh 50 parts of silane monomer, which is prepared by compounding dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane in a mass ratio of 10:10:10, and slowly add them into a three-necked flask. After the addition is completed, heat the flask to 65°C for hydrolysis reaction for 3 hours;

[0082] (3) washing the reaction solution after the hydrolysis reaction with water until it becomes neutral to obtain a hydrolyzed prepolymer;

[0083] (4) heating the hydrolyzed prepolymer to 100° C. for reaction for 2 hours, and adding xylene to adjust the solid content to about 50%, thereby obtaining an organosilicon resin;

[0084] (5) mixing an acrylic acid monomer, a double bond silane and an initiator in a mass ratio of 10:0.8:0.5 and stirring to obtain an acrylic acid mixed solution;

[0085] The acrylic monomers are methyl acrylate and ethylene glycol diacrylate, the double bond silane is vinyl dimethyl siloxane, and the initiator is dibenzoyl peroxide;

[0086] (6) The organic silicone resin and the acrylic acid mixture are heated to 60° C. in a mass ratio of 100:10 and reacted for 6 hours to obtain a modified organic silicone resin.

[0087] The preparation method of the modified filler comprises:

[0088] (1) Diamond powder, silicon carbide, mica powder, copper chromium black, and low-melting point glass powder were baked in a muffle furnace at 550°C for 2 h in a mass ratio of 3:10:15:5:30;

[0089] In addition, the diamond powder has a particle size of 15 microns, the silicon carbide is black silicon carbide with a particle size of 13 microns, and the copper chrome black has a particle size of 4 microns; the mica powder is Grey GA-5 with a particle size of 13 microns; the low-melting point glass powder is a compound of YB-D45 and YB-D50 with a ratio of 2:1, of which the melting temperature of YB-D45 is 500°C, and the melting temperature of YB-D50 is 500°C.

[0090] (2) After cooling, ball milling is performed, and mixed grinding is performed for 1.5 hours to obtain a uniform ball-milled filler;

[0091] (3) Dissolve 5% KH-550 silane coupling agent in ethanol, disperse at 800 r / min for 5 minutes, add ball-milled filler while dispersing, and after the ball-milled filler is added, heat to 70° C. and disperse for another 80 minutes; finally, age, centrifuge, and dry to obtain the modified filler.

[0092] A method for preparing a high-performance organosilicon high-temperature resistant coating comprises:

[0093] Add 40 parts of modified silicone resin, 0.9 parts of dispersant, 0.1 parts of defoaming agent, 1 part of anti-settling agent by weight, and disperse at high speed for 30 minutes to fully activate the anti-settling agent. Then add 40 parts of modified filler and disperse at high speed for 75 minutes. Add 10 parts of solvent to adjust the viscosity. Finally, add 8 parts of curing agent to obtain a high-performance silicone high-temperature resistant coating.

[0094] Example 3

[0095] A high-performance organosilicon high-temperature resistant coating comprises the following components by weight: 50 parts of modified organosilicon resin, 0.1 parts of dispersant, 1 part of defoamer, 0.9 parts of anti-settling agent, 30 parts of modified filler, 8 parts of solvent and 10 parts of curing agent.

[0096] The dispersant is BYK-203, the defoamer is TEGO-900, the anti-settling agent is polyamide wax slurry, the solvent is trimethylbenzene, and the curing agent is a mixture of Bayer 3800 and Bayer 3390, with a ratio of 1:1.

[0097] The modified silicone resin is an acrylic acid modified silicone resin, and the preparation method of the acrylic acid modified silicone resin comprises:

[0098] (1) Weigh 200 parts of deionized water and 15 parts of acetone by mass, mix them evenly, adjust the pH value to about 4 with hydrochloric acid, and transfer them into a three-necked flask;

[0099] (2) Weigh 75 parts of silane monomer, which is prepared by compounding dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane in a mass ratio of 6:2:2, and slowly add them into a three-necked flask. After the addition is completed, heat the flask to 68°C and hydrolyze for 3.5 hours;

[0100] (3) washing the reaction solution after the hydrolysis reaction with water until it becomes neutral to obtain a hydrolyzed prepolymer;

[0101] (4) heating the hydrolyzed prepolymer to 105° C. for reaction for 2.25 h, and adding xylene to adjust the solid content to about 50%, thereby obtaining an organosilicon resin;

[0102] (5) mixing an acrylic acid monomer, a double bond silane and an initiator in a mass ratio of 9:1:0.2 and stirring to obtain an acrylic acid mixed solution;

[0103] The acrylic monomer is ethoxylated bisphenol A diacrylate, the double bond silane is ethoxylated bisphenol A diacrylate, and the initiator is azobisisoheptanenitrile;

[0104] (6) The organic silicone resin and the acrylic acid mixture are heated to 65° C. in a mass ratio of 100:8 and reacted for 5 hours to obtain a modified organic silicone resin.

[0105] The preparation method of the modified filler comprises:

[0106] (1) baking diamond powder, silicon carbide, mica powder, copper chromium black, and low-melting point glass powder in a muffle furnace at a mass ratio of 5:5:5:8:10 for 2.5 h at 575°C;

[0107] In addition, the diamond powder has a particle size of 20 microns, the silicon carbide is black silicon carbide with a particle size of 15 microns, and the copper chrome black has a particle size of 5 microns; the mica powder is Grey GA-5 with a particle size of 15 microns; the low-melting point glass powder is a compound of YB-D45 and YB-D50 with a ratio of 2:1, of which the melting temperature of YB-D45 is 580°C and the melting temperature of YB-D50 is 650°C.

[0108] (2) After cooling, ball milling is performed, and mixed grinding is performed for 1.25 hours to obtain a uniform ball-milled filler;

[0109] (3) 10% KH-550 silane coupling agent was dissolved in ethanol and dispersed at 600 r / min for 8 minutes. The ball-milled filler was added during dispersion. After the ball-milled filler was added, the temperature was raised to 75° C. and then dispersed for another 85 minutes. Finally, the modified filler was obtained by aging, centrifugation and drying.

[0110] A method for preparing a high-performance organosilicon high-temperature resistant coating comprises:

[0111] Add 50 parts of modified silicone resin, 0.1 parts of dispersant, 1 part of defoamer, 0.9 parts of anti-settling agent by weight, and disperse at high speed for 20 minutes to fully activate the anti-settling agent. Then add 30 parts of modified filler and disperse at high speed for 60 minutes. Add 8 parts of solvent to adjust the viscosity. Finally, add 10 parts of curing agent to obtain a high-performance silicone high-temperature resistant coating.

[0112] In order to further illustrate the key points of this patent, a comparative case is added for illustration.

[0113] Comparative Example 1

[0114] The preparation method is basically the same as that of Example 1, wherein the modified silicone resin is changed to Jianuo JN-A1 silicone resin.

[0115] Comparative Example 2

[0116] The preparation method is basically the same as that of Example 1, wherein the filler not modified by the silane coupling agent is directly used.

[0117] Comparative Example 3

[0118] The preparation method is basically the same as that of Example 1, wherein the diamond powder of the modified filler is replaced by mica.

[0119] The performance of the high-performance organosilicon high temperature resistant coatings prepared in Examples 1-3 and Comparative Examples 1-3 was tested, and the specific test results are shown in Table 1.

[0120] Table 1 Performance test results

[0121]

[0122] The performance test is conducted by spraying the coating evenly on a polished steel plate. The film thickness is 30μm according to the standard or if there is no regulation. The test before high temperature is conducted after 7 days of self-drying and curing. The test after high temperature is conducted after 7 days of self-drying, baking at 600℃ for 200h, and curing for 1 day. The adhesion is tested by the cross-cut method GB / T 9286, the impact resistance is tested by the GB / T1732 method, the wear resistance is tested by the abrasion test by the GB / T 1768 method, with a load of 1kg and 1000 turns, and the acid resistance is tested by the GB / T9274 method.

[0123] In the examples, the performances show some differences due to different formula ratios. For examples 1-3, there is no significant difference in adhesion, impact resistance and acid resistance before and after high temperature. The wear rate of example 1 is moderate before and after high temperature. Compared with example 1: Example 2 has a high pigment-to-base ratio, and the crosslinking density is low before high temperature, which increases the wear. After high temperature, the inorganic components, especially diamond powder, increase and reduce the wear. Example 3 has a low pigment-to-base ratio. Although the crosslinking density is increased before high temperature, the wear-resistant filler is too small, which increases the wear. After high temperature, the wear is also increased due to the small amount of wear-resistant filler.

[0124] Compared with Example 1, since the silicone resin in Comparative Example 1 is not modified, the adhesion between the entire coating components and between the coating and the substrate is reduced, thereby affecting the overall performance of the coating; since the filler in Comparative Example 2 is not modified, the overall performance of the coating is reduced; since Comparative Example 3 does not add diamond powder and has no high-hardness frame support, the wear of the entire system before and after high temperature increases significantly.

[0125] Therefore, the high-performance organosilicon high-temperature resistant coating prepared in the present application has excellent properties such as high-temperature resistance, acid resistance, and wear resistance before and after 600°C high temperature.

[0126] The above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A high-performance silicone high-temperature resistant coating, characterized in that: The composition comprises the following components in parts by weight: 40-50 parts of modified silicone resin, 0.1-1 parts of dispersant, 0.1-1 parts of defoamer, 0.4-1 parts of anti-settling agent, 30-40 parts of modified filler, 8-10 parts of solvent, 8-10 parts of curing agent; The modified filler is prepared by compounding diamond powder, silicon carbide, mica powder, copper chromium black and low-melting-point glass powder.

2. The high-performance organosilicon high temperature resistant coating according to claim 1, characterized in that: The weight ratio of the diamond powder, the silicon carbide, the mica powder, the copper chrome black and the low-melting-point glass powder is (1-5): (5-10): (5-15): (5-10): (10-30).

3. The high-performance organosilicon high temperature resistant coating according to claim 1, characterized in that: The preparation method of the modified filler comprises: Diamond powder, silicon carbide, mica powder, copper chromium black, and low-melting-point glass powder are baked in a muffle furnace at 550-600°C for 2-3 hours according to the proportion, ball-milled after cooling, and mixed and ground for 1-1.5 hours to obtain a uniform ball-milled filler; Dissolve 2-10% of the total reactant mass of KH-550 silane coupling agent in ethanol, disperse at 600-800 r / min for 5-10 min, add the ball-milled filler while dispersing, heat to 70-80° C. after adding the ball-milled filler, and disperse for 80-90 min; finally, age, centrifuge and dry to obtain the modified filler.

4. The high-performance organosilicon high temperature resistant coating according to claim 3, characterized in that: The particle size of the diamond powder is 10-20 microns; the particle size of the silicon carbide is 10-15 microns; the particle size of the copper chrome black is 3-5 microns; the particle size of the mica powder is 10-15 microns; the low-melting point glass powder is a compound of YB-D45 and YB-D50, and the ratio is (2-2.5):

1.

5. The high-performance organosilicon high temperature resistant coating according to claim 1, characterized in that: The modified silicone resin includes an acrylic acid modified silicone resin; and the preparation method of the acrylic acid modified silicone resin includes: Weigh 100-200 parts of deionized water and 15-20 parts of acetone by mass, mix well, adjust the pH value to 3.8-4.2 with hydrochloric acid, and put into a container; 50-100 parts of silane monomer are added dropwise to the container, and then the temperature is raised to 65-70° C. for hydrolysis reaction for 3-4 hours; The reaction liquid after the hydrolysis reaction is washed with water until it becomes neutral to obtain a hydrolyzed prepolymer; The hydrolyzed prepolymer is heated to 100-110° C. for reaction for 2-2.5 hours, and xylene is added to adjust the solid content to 47-53%, thereby obtaining a silicone resin; The acrylic monomer, double bond silane and initiator are mixed and stirred to obtain an acrylic acid mixed liquid; The organic silicone resin and the acrylic acid mixed solution are heated to 60-80° C. in a mass ratio of 100:(5-10) and reacted for 4-6 hours to obtain a modified organic silicone resin.

6. The high-performance organosilicon high temperature resistant coating according to claim 5, characterized in that: The silane monomer is prepared by compounding dimethyldiethoxysilane, diphenyldimethoxysilane and phenyltrimethoxysilane, and the mass ratio of the dimethyldiethoxysilane, the diphenyldimethoxysilane and the phenyltrimethoxysilane is (2-10):(1-10):(1-10).

7. The high-performance organosilicon high temperature resistant coating according to claim 5, characterized in that: The mass ratio of the acrylic monomer, the double bond silane and the initiator is (8-10): (0.8-1.2): (0.05-0.5); The acrylic monomer includes one or more of methyl acrylate, n-butyl acrylate, hydroxyethyl methacrylate, isobornyl acrylate, ethylene glycol diacrylate, and ethoxylated bisphenol A diacrylate; the double-bond silane includes one or two of vinyl dimethyl siloxane and methyl vinyl dimethoxy silane; and the initiator includes one or more of dibenzoyl peroxide, isopropylbenzene hydroperoxide, and azobisisoheptonitrile.

8. The high-performance organosilicon high temperature resistant coating according to claim 1, characterized in that: The dispersant is a high molecular weight block copolymer containing pigment affinity groups, specifically including one or two of BYK-163 and BYK-203; the defoamer is a polysiloxane solution, specifically including one or two of BYK-066N and TEGO-900; the anti-settling agent includes one or more of fumed silica, organic bentonite, and polyamide wax slurry.

9. The high-performance organosilicon high temperature resistant coating according to claim 1, characterized in that: The solvent includes one or more of xylene, trimethylbenzene, ethyl acetate and propylene glycol methyl ether acetate; and the curing agent includes an isocyanate curing agent.

10. A method for preparing a high-performance organosilicon high-temperature resistant coating, characterized in that: Based on the high-performance organosilicon high-temperature resistant coating according to any one of claims 1 to 9, the preparation method of the high-performance organosilicon high-temperature resistant coating comprises the following steps: Add modified silicone resin, dispersant, defoamer, anti-settling agent in proportion, and disperse at high speed for 20-30 minutes to fully activate the anti-settling agent. Then add modified filler in proportion and disperse at high speed for 60-90 minutes to evenly disperse the powder. Add solvent to adjust the viscosity, and finally add curing agent to obtain high-performance silicone high-temperature resistant coating.

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