High temperature resistant thermal insulation coating, preparation method and application thereof in petrochemical pipeline

Abstract

The application discloses a high-temperature-resistant thermal insulation coating, a preparation method thereof and application of the high-temperature-resistant thermal insulation coating in petrochemical pipelines. The high-temperature-resistant thermal insulation coating comprises 100-140 parts of an organic silicon modified acrylic water-based dispersion, 10-30 parts of modified hollow glass microbeads, 10-30 parts of a curing agent, 5-10 parts of nano reflective powder and 2-4 parts of an additive. Compared with the prior art, the high-temperature-resistant thermal insulation coating prepared by the application has the advantages of high high-temperature resistance, good thermal insulation effect, high aging resistance and high chemical stability.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a high-temperature resistant heat-insulating coating, its preparation method, and its application in petrochemical pipelines. Background Technology

[0002] In the petrochemical industry, approximately one-third of the total energy consumption is lost annually due to heat loss from pipelines, and corrosion of petrochemical pipelines also poses numerous safety hazards to production and operations. Therefore, corrosion prevention and insulation are crucial for the petrochemical industry.

[0003] Currently, domestic refining and chemical enterprises typically use traditional porous materials such as rock wool and aluminum silicate rolls for thermal insulation of equipment and pipelines. The insulation layer thickness is generally 100-200mm, resulting in complex construction procedures and high costs. Furthermore, the thick insulation layer can conceal damage to equipment and pipelines, making it difficult for petrochemical enterprises to avoid common production risks and safety hazards. Meanwhile, the insulation layer structure of irregularly shaped components such as elbows, tees, and valves is complex, with numerous interfaces, making construction extremely difficult. These areas are often exposed, representing weak points in the thermal insulation of equipment and pipelines. In particular, traditional porous insulation materials often lack corrosion resistance; corrosive agents can easily adhere to and accumulate in their pores, becoming a heat conduction medium. This not only significantly reduces the thermal insulation efficiency of equipment and pipelines but also shortens the service life of the entire insulation system.

[0004] CN1935912A discloses a nano-ceramic high-temperature resistant insulating coating and its preparation method, which improves the high-temperature resistant insulating performance of the coating by adding ceramic microspheres. However, the nano-ceramic microspheres added to the nano-ceramic high-temperature resistant insulating coating prepared by this method may have poor interfacial compatibility with the film-forming material. CN115873456A discloses a water-based high-temperature resistant coating and its preparation method, which improves the high-temperature resistant performance of the coating by adding mixed water-based resin and functional modified powder. The coating prepared by this method mainly provides reflective and radiative heat insulation, and cannot achieve the desired heat insulation effect. Summary of the Invention

[0005] In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a high-temperature resistant thermal insulation coating with the advantages of high temperature resistance, good thermal insulation performance and strong chemical stability.

[0006] To achieve the above objectives, the present invention provides a high-temperature resistant thermal insulation coating and its preparation method.

[0007] The detailed technical solution of this invention is as follows:

[0008] A high-temperature resistant thermal insulation coating, comprising the following raw materials:

[0009] By weight, the composition is as follows: 100-140 parts of silicone-modified acrylic aqueous dispersion, 10-30 parts of modified hollow glass microspheres, 10-30 parts of curing agent, 5-10 parts of nano-reflective powder, 2-4 parts of additives, and 20-40 parts of water.

[0010] The organosilicon-modified acrylic aqueous dispersion is prepared by the following method:

[0011] By weight, under nitrogen protection, heat 100-125 parts of solvent to 110-140℃, add a mixture of 15-20 parts glycidyl acrylate, 15-20 parts methyl methacrylate, 15-20 parts benzoyl acrylate, 15-20 parts acrylic acid and 1-2 parts initiator dropwise into the solvent over 1-3 hours. After the dropwise addition is complete, add 5-15 parts dimethylphenylvinylsilane over 5-15 minutes, and add 0.1-1 parts initiator. React at 110-140℃ and 600-800 rpm for 2-4 hours. Lower the temperature to 60-80℃, add 120-180 parts water, stir at 600-800 rpm for 5-10 minutes, add diethanolamine to adjust the pH to 6-8, and obtain an organosilicon-modified acrylic acid aqueous dispersion.

[0012] The initiator is azobisisobutyronitrile.

[0013] As a further explanation of the present invention: the organosilicon-modified acrylic aqueous dispersion uses glycidyl acrylate, methyl methacrylate, benzoyl acrylate, and acrylic acid as mixed monomers to synthesize polymers, which can improve chemical properties. Among them, the benzene ring in the molecular structure of benzoyl acrylate can improve the strength, chemical properties, and water resistance when preparing polymers; the polymer prepared with methyl methacrylate can improve its flexibility and impact resistance; the polymer prepared with glycidyl acrylate can improve its adhesion; the carboxyl group in the molecular structure of acrylic acid can be further used for crosslinking or reaction with other monomers, and the mixed monomers can improve the physicochemical properties and crosslinking strength.

[0014] The modified hollow glass microspheres are prepared by the following method:

[0015] By weight, 10-30 parts of hollow glass microspheres are dried at 100-140℃ for 2-4 hours, then added to 100-150 parts of ethanol. The mixture is stirred at 50-70℃ and 600-800 rpm for 5-10 minutes. 1-3 parts of coupling agent are added and reacted for 20-40 minutes. The mixture is then filtered. The obtained hollow glass microspheres are dried at 100-140℃ for 2-4 hours and then passed through a 200-mesh filter and sealed to obtain modified hollow glass microspheres.

[0016] The coupling agent is an aluminate coupling agent.

[0017] As a further explanation of the present invention: Hollow glass microspheres are a type of hollow material with characteristics such as low density, high strength, and low thermal conductivity. They contain a large amount of still air, hence the thermal conductivity of hollow glass microspheres is typically only 0.05-0.1 W / (m·K). However, as an inorganic material, hollow glass microspheres have poor interfacial compatibility with organic emulsions, resulting in numerous voids between them. This leads to increased water absorption of the dry coating film. Modifying their surface with coupling agents can improve their interfacial compatibility with organic emulsions.

[0018] The curing agent is at least one of isocyanate and aziridine.

[0019] The nano-reflective powder is at least one of nano-titanium dioxide, nano-zinc oxide, and nano-silica.

[0020] The additive is at least one of defoamer, dispersant, and antioxidant.

[0021] This invention provides a method for preparing a high-temperature resistant thermal insulation coating, the method of which is as follows:

[0022] Step 1: Mix 100-140 parts of silicone-modified acrylic aqueous dispersion and 10-30 parts of modified hollow glass microspheres evenly and set aside.

[0023] Step 2: Mix 10-30 parts curing agent, 2-4 parts additives, 5-10 parts nano-reflective powder and 20-40 parts water until homogeneous and set aside.

[0024] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating;

[0025] The above portions are by weight.

[0026] The beneficial effects of this invention are:

[0027] Compared with existing technologies, the coating uses silicone-modified acrylic aqueous dispersion and modified hollow glass microspheres. These components work together to improve the coating's high-temperature resistance, aging resistance and chemical stability. Detailed Implementation

[0028] A high-temperature resistant thermal insulation coating, comprising the following raw materials:

[0029] By weight, it includes 100-140 parts of silicone-modified acrylic aqueous dispersion, 10-30 parts of modified hollow glass microspheres, 10-30 parts of curing agent, 5-10 parts of nano-reflective powder, 2-4 parts of additives, and 20-40 parts of water.

[0030] The organosilicon-modified acrylic aqueous dispersion is prepared by the following method:

[0031] By weight, under nitrogen protection, heat 100-125 parts of solvent to 110-140℃, and add a mixture of 15-20 parts of glycidyl acrylate, 15-20 parts of methyl methacrylate, 15-20 parts of benzoyl acrylate, 15-20 parts of acrylic acid and 1-2 parts of initiator dropwise to the solvent over 1-3 hours. After the dropwise addition is complete, add 5-15 parts of dimethylphenylvinylsilane over 5-15 minutes, and add 0.1-1 parts of initiator. React at 110-140℃ and 600-800 rpm for 2-4 hours. Lower the temperature to 60-80℃, add 120-180 parts of water, stir at 600-800 rpm for 5-10 minutes, and add diethanolamine to adjust the pH to 6-8 to obtain an organosilicon-modified acrylic acid aqueous dispersion.

[0032] The organosilicon-modified aqueous acrylic dispersion uses glycidyl acrylate, methyl methacrylate, benzoyl acrylate, and acrylic acid as mixed monomers to synthesize polymers, which improves chemical properties. The benzene ring in the benzoyl acrylate molecular structure enhances the strength, chemical properties, and water resistance of the polymer during preparation. Methyl methacrylate improves the flexibility and impact resistance of the polymer. Glycidyl acrylate improves the adhesion. The carboxyl group in the acrylic acid molecular structure can be further used for crosslinking or reaction with other monomers. The mixed monomers improve the physicochemical properties and crosslinking strength. The acrylic resin prepared by the organosilicon-modified mixed monomers exhibits good high-temperature resistance and aging resistance, while retaining good chemical resistance, flexibility, impact resistance, water resistance, and adhesion.

[0033] The modified hollow glass microspheres are prepared by the following method:

[0034] By weight, 10-30 parts of hollow glass microspheres are dried at 100-140℃ for 2-4 hours, then added to 100-150 parts of ethanol. The mixture is stirred at 50-70℃ and 600-800 rpm for 5-10 minutes. 1-3 parts of coupling agent are added and reacted for 20-40 minutes. The mixture is then filtered. The obtained hollow glass microspheres are dried at 100-140℃ for 2-4 hours and then passed through a 200-mesh filter and sealed to obtain modified hollow glass microspheres.

[0035] Hollow glass microspheres are a type of hollow material characterized by low density, high strength, and low thermal conductivity. They contain a large amount of still air, resulting in a thermal conductivity typically of only 0.05–0.1 W / (m·K). However, as an inorganic material, hollow glass microspheres exhibit poor interfacial compatibility with organic emulsions, often resulting in numerous voids and increased water absorption in the dry film coating. Modifying their surface with coupling agents can improve their interfacial compatibility with organic emulsions. The silanol groups on the surface of the hollow glass microspheres undergo dehydration condensation with the hydroxyl groups formed after the coupling agent hydrolyzes, forming –Si–O–Si–. This grafts a very small monolayer of organic coupling agent terminals onto the surface of the hollow glass microspheres. Simultaneously, because the matrix remains hollow glass microspheres (SiO2), good chemical properties are retained while improving interfacial compatibility with organic emulsions.

[0036] The curing agent is at least one of isocyanate and aziridine.

[0037] The nano-reflective powder is at least one of nano-titanium dioxide, nano-zinc oxide, and nano-silica.

[0038] The aforementioned nanomaterials all have high reflectivity, enabling them to reflect visible and infrared light from sunlight and scatter incident light, reducing light penetration and thus decreasing heat absorption.

[0039] The additive is at least one of defoamer, dispersant, and antioxidant.

[0040] This invention provides a method for preparing a high-temperature resistant thermal insulation coating, the method of which is as follows:

[0041] Step 1: Mix 100-140 parts of silicone-modified acrylic aqueous dispersion and 10-30 parts of modified hollow glass microspheres evenly and set aside.

[0042] Step 2: Mix 10-30 parts curing agent, 2-4 parts additives, 5-10 parts nano-reflective powder and 20-40 parts water until homogeneous and set aside.

[0043] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating.

[0044] The sources and parameters of some chemical substances in the examples are as follows:

[0045] Glycidyl acrylate, CAS No.: 106-90-1;

[0046] Polydimethylsiloxane, CAS No.: 63148-62-9, viscosity 0.65cSt (25℃), sourced from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0047] BYK-028 and BYK-301 are from BYK Chemicals;

[0048] Dimethylchlorosilane, CAS No.: 1066-35-9;

[0049] Dimethylphenylvinylsilane, CAS No.: 1125-26-4;

[0050] Nano titanium dioxide, particle size: 5-10nm;

[0051] Nano zinc oxide, particle size 20nm;

[0052] Hollow glass microspheres, model: HL38, true density (g / cm³) 3 0.38, D50 (μm): 40, D90 (μm): 65, compressive strength: 5500psi, flocculation rate: ≥95%, moisture content: ≤3%, sourced from Zhengzhou Shenglait Hollow Microsphere New Material Co., Ltd.

[0053] Isopropyl distearate aluminate, CAS: 5919-73-3;

[0054] Isopropyl tris(dioctylpyrophosphoryloxy)titanate, CAS: 67691-13-8;

[0055] Isocyanate, CAS No.: 75-13-8.

[0056] Example 1

[0057] A method for preparing a high-temperature resistant thermal insulation coating includes the following steps:

[0058] Step 1: Mix 100g of silicone-modified acrylic aqueous dispersion and 10g of modified hollow glass microspheres evenly and set aside.

[0059] Step 2: Mix 20g of curing agent, 2g of additive, 8g of nano-reflective powder and 40g of water until well combined and set aside.

[0060] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating.

[0061] The organosilicon-modified acrylic aqueous dispersion in step one is prepared by the following method:

[0062] Under nitrogen protection, a mixed solvent of 75g propylene glycol methyl ether and 25g butanol was heated to 125°C. A mixture of 15g glycidyl acrylate, 15g methyl methacrylate, 15g benzoyl acrylate, 15g acrylic acid, and 1g azobisisobutyronitrile was added dropwise to the solvent over 2 hours. After the addition was complete, 5g dimethylphenylvinylsilane was added over 10 minutes, and 0.5g azobisisobutyronitrile was added as a supplement. The reaction was carried out at 125°C and 800 rpm for 3 hours. The temperature was then lowered to 70°C, 150g water was added, and the mixture was stirred at 800 rpm for 5 minutes. Diethanolamine was added to adjust the pH to 8, yielding an organosilicon-modified acrylic acid aqueous dispersion.

[0063] The modified hollow glass microspheres in step one are prepared by the following method:

[0064] 10g of hollow glass microspheres were dried at 120℃ for 2h and then added to 100g of ethanol. The mixture was stirred at 60℃ and 800rpm for 5min. 2g of isopropyl distearate aluminum ester was added and reacted for 30min. The mixture was then filtered. The resulting hollow glass microspheres were dried at 120℃ for 2h and then passed through a 200-mesh filter and sealed to obtain modified hollow glass microspheres.

[0065] The curing agent is isocyanate.

[0066] The additives are 0.5g of defoamer BYK-028 and 1.5g of dispersant BYK-301.

[0067] The nano-reflective powder is a mixture of nano-titanium dioxide and nano-zinc oxide in a mass ratio of 1:1.

[0068] Example 2

[0069] A method for preparing a high-temperature resistant thermal insulation coating includes the following steps:

[0070] Step 1: Mix 100g of silicone-modified acrylic aqueous dispersion and 10g of modified hollow glass microspheres evenly and set aside.

[0071] Step 2: Mix 20g of curing agent, 2g of additive, 8g of nano-reflective powder and 40g of water until well combined and set aside.

[0072] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating.

[0073] The organosilicon-modified acrylic aqueous dispersion in step one is prepared by the following method:

[0074] Under nitrogen protection, a mixed solvent of 75g propylene glycol methyl ether and 25g butanol was heated to 125°C. A mixture of 15g glycidyl acrylate, 15g methyl methacrylate, 15g benzoyl acrylate, 15g acrylic acid, and 1g azobisisobutyronitrile was added dropwise to the solvent over 2 hours. After the addition was complete, 5g polydimethylsiloxane was added over 10 minutes, and 0.5g azobisisobutyronitrile was added as a supplement. The reaction was carried out at 125°C and 800 rpm for 3 hours. The temperature was then lowered to 70°C, 150g water was added, and the mixture was stirred at 800 rpm for 5 minutes. Diethanolamine was added to adjust the pH to 8, yielding an organosilicon-modified acrylic acid aqueous dispersion.

[0075] The modified hollow glass microspheres in step one are prepared by the following method:

[0076] 10g of hollow glass microspheres were dried at 120℃ for 2h and then added to 100g of ethanol. The mixture was stirred at 60℃ and 800rpm for 5min. 2g of isopropyl distearate aluminum ester was added and reacted for 30min. The mixture was then filtered. The resulting hollow glass microspheres were dried at 120℃ for 2h and then passed through a 200-mesh filter and sealed to obtain modified hollow glass microspheres.

[0077] The curing agent is isocyanate.

[0078] The additives are 0.5g of defoamer BYK-028 and 1.5g of dispersant BYK-301.

[0079] The nano-reflective powder is a mixture of nano-titanium dioxide and nano-zinc oxide in a mass ratio of 1:1.

[0080] Example 3

[0081] A method for preparing a high-temperature resistant thermal insulation coating includes the following steps:

[0082] Step 1: Mix 100g of silicone-modified acrylic aqueous dispersion and 10g of modified hollow glass microspheres evenly and set aside.

[0083] Step 2: Mix 20g of curing agent, 2g of additive, 8g of nano-reflective powder and 40g of water until well combined and set aside.

[0084] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating.

[0085] The organosilicon-modified acrylic aqueous dispersion in step one is prepared by the following method:

[0086] Under nitrogen protection, a mixed solvent of 75g propylene glycol methyl ether and 25g butanol was heated to 125°C. A mixture of 15g glycidyl acrylate, 15g methyl methacrylate, 15g benzoyl acrylate, 15g acrylic acid, and 1g azobisisobutyronitrile was added dropwise to the solvent over 2 hours. After the addition was complete, 5g dimethylchlorosilane was added over 10 minutes, and 0.5g azobisisobutyronitrile was added as a supplement. The reaction was carried out at 125°C and 800 rpm for 3 hours. The temperature was then lowered to 70°C, 150g water was added, and the mixture was stirred at 800 rpm for 5 minutes. Diethanolamine was added to adjust the pH to 8, yielding an organosilicon-modified acrylic acid aqueous dispersion.

[0087] The modified hollow glass microspheres in step one are prepared by the following method:

[0088] 10g of hollow glass microspheres were dried at 120℃ for 2h and then added to 100g of ethanol. The mixture was stirred at 60℃ and 800rpm for 5min. 2g of isopropyl distearate aluminum ester was added and reacted for 30min. The mixture was then filtered. The resulting hollow glass microspheres were dried at 120℃ for 2h and then passed through a 200-mesh filter and sealed to obtain modified hollow glass microspheres.

[0089] The curing agent is isocyanate.

[0090] The additives are 0.5g of defoamer BYK-028 and 1.5g of dispersant BYK-301.

[0091] The nano-reflective powder is a mixture of nano-titanium dioxide and nano-zinc oxide in a mass ratio of 1:1.

[0092] Comparative Example 1

[0093] A method for preparing a high-temperature resistant thermal insulation coating includes the following steps:

[0094] Step 1: Mix 100g of acrylic acid aqueous dispersion and 10g of modified hollow glass microspheres evenly and set aside.

[0095] Step 2: Mix 20g of curing agent, 2g of additive, 8g of nano-reflective powder and 40g of water until well combined and set aside.

[0096] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating.

[0097] The aqueous dispersion of acrylic acid in step one is prepared by the following method:

[0098] Under nitrogen protection, a mixed solvent of 75g propylene glycol methyl ether and 25g butanol was heated to 125°C. A mixture of 15g glycidyl acrylate, 15g methyl methacrylate, 15g benzoyl acrylate, 15g acrylic acid, and 1g azobisisobutyronitrile was added dropwise to the solvent over 2 hours and reacted at 125°C and 800 rpm for 3 hours. The temperature was then lowered to 70°C, 150g water was added, and the mixture was stirred at 800 rpm for 5 minutes. Diethanolamine was added to adjust the pH to 8, yielding an aqueous dispersion of acrylic acid.

[0099] The modified hollow glass microspheres in step one are prepared by the following method:

[0100] 10g of hollow glass microspheres were dried at 120℃ for 2h and then added to 100g of ethanol. The mixture was stirred at 60℃ and 800rpm for 5min. 2g of isopropyl distearate aluminum ester was added and reacted for 30min. The mixture was then filtered. The resulting hollow glass microspheres were dried at 120℃ for 2h and then passed through a 200-mesh filter and sealed to obtain modified hollow glass microspheres.

[0101] The curing agent is isocyanate.

[0102] The additives are 0.5g of defoamer BYK-028 and 1.5g of dispersant BYK-301.

[0103] The nano-reflective powder is a mixture of nano-titanium dioxide and nano-zinc oxide in a mass ratio of 1:1.

[0104] Comparative Example 2

[0105] A method for preparing a high-temperature resistant thermal insulation coating includes the following steps:

[0106] Step 1: Mix 100g of silicone-modified acrylic aqueous dispersion and 10g of hollow glass microspheres evenly and set aside.

[0107] Step 2: Mix 20g of curing agent, 2g of additive, 8g of nano-reflective powder and 40g of water until well combined and set aside.

[0108] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating.

[0109] The organosilicon-modified acrylic aqueous dispersion in step one is prepared by the following method:

[0110] Under nitrogen protection, a mixed solvent of 75g propylene glycol methyl ether and 25g butanol was heated to 125°C. A mixture of 15g glycidyl acrylate, 15g methyl methacrylate, 15g benzoyl acrylate, 15g acrylic acid, and 1g azobisisobutyronitrile was added dropwise to the solvent over 2 hours. After the addition was complete, 5g dimethylphenylvinylsilane was added over 10 minutes, and 0.5g azobisisobutyronitrile was added as a supplement. The reaction was carried out at 125°C and 800 rpm for 3 hours. The temperature was then lowered to 70°C, 150g water was added, and the mixture was stirred at 800 rpm for 5 minutes. Diethanolamine was added to adjust the pH to 8, yielding an organosilicon-modified acrylic acid aqueous dispersion.

[0111] The curing agent is isocyanate.

[0112] The additives are 0.5g of defoamer BYK-028 and 1.5g of dispersant BYK-301.

[0113] The nano-reflective powder is a mixture of nano-titanium dioxide and nano-zinc oxide in a mass ratio of 1:1.

[0114] Comparative Example 3

[0115] A method for preparing a high-temperature resistant thermal insulation coating includes the following steps:

[0116] Step 1: Mix 100g of silicone-modified acrylic aqueous dispersion and 10g of modified hollow glass microspheres evenly and set aside.

[0117] Step 2: Mix 20g of curing agent, 2g of additive, 8g of nano-reflective powder and 40g of water until well combined and set aside.

[0118] Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating.

[0119] The organosilicon-modified acrylic aqueous dispersion in step one is prepared by the following method:

[0120] Under nitrogen protection, a mixed solvent of 75g propylene glycol methyl ether and 25g butanol was heated to 125°C. A mixture of 15g glycidyl acrylate, 15g methyl methacrylate, 15g benzoyl acrylate, 15g acrylic acid, and 1g azobisisobutyronitrile was added dropwise to the solvent over 2 hours. After the addition was complete, 5g dimethylphenylvinylsilane was added over 10 minutes, and 0.5g azobisisobutyronitrile was added as a supplement. The reaction was carried out at 125°C and 800 rpm for 3 hours. The temperature was then lowered to 70°C, 150g water was added, and the mixture was stirred at 800 rpm for 5 minutes. Diethanolamine was added to adjust the pH to 8, yielding an organosilicon-modified acrylic acid aqueous dispersion.

[0121] The modified hollow glass microspheres in step one are prepared by the following method:

[0122] 10g of hollow glass microspheres were dried at 120℃ for 2h and then added to 100g of ethanol. The mixture was stirred at 60℃ and 800rpm for 5min. 2g of isopropyl tris(dioctyl pyrophosphate) titanate was added and reacted for 30min. The mixture was then filtered. The resulting hollow glass microspheres were dried at 120℃ for 2h and then passed through a 200-mesh filter and sealed to obtain modified hollow glass microspheres.

[0123] The curing agent is isocyanate.

[0124] The additives are 0.5g of defoamer BYK-028 and 1.5g of dispersant BYK-301.

[0125] The nano-reflective powder is a mixture of nano-titanium dioxide and nano-zinc oxide in a mass ratio of 1:1.

[0126] Test Example 1

[0127] The following performance tests were conducted on the high-temperature resistant thermal insulation coatings with different formulations mentioned above, and the results are listed in Table 1:

[0128] The adhesion of the coating was tested according to GB / T 5210-2006 "Determination of adhesion of paints and varnishes by pull-out method";

[0129] GB / T 23987-2009 Artificial weathering exposure of paint and varnish coatings to fluorescent ultraviolet light and water.

[0130] High temperature resistance test: The freshly prepared coating was applied to a clean steel plate with a coating thickness of 300 μm. After surface drying, it was dried in a constant temperature drying oven at 60℃ for 120 min, then removed and allowed to cool naturally indoors for 24 h. The coating sample was then baked at 100℃ and 200℃ for 10 h.

[0131] Table 1

[0132]

[0133] A comparison of Examples 1-3 reveals that the high-temperature resistant thermal insulation coating of Example 1 exhibits the best adhesion. This is likely due to the addition of a dimethylphenylvinylsilane-modified aqueous acrylic dispersion. The organosilicon-modified aqueous acrylic dispersion improves the adhesion between the coating and the substrate, while the addition of dimethylphenylvinylsilane further increases the crosslinking density of the coating, enhancing the chemical bond between the coating and the substrate, thereby improving adhesion.

[0134] A comparison of Examples 1-3 and Comparative Example 3 reveals that the high-temperature resistant insulation coatings of Examples 1-3 exhibit significantly better high-temperature resistance and aging resistance than those of Comparative Example 3. This is because Examples 1-3 use hollow glass beads modified with an aluminate coupling agent, while Comparative Example 3 uses hollow glass beads modified with a titanate coupling agent. When the inorganic end of the aluminate coupling agent reacts with the hydroxyl groups on the surface of the hollow glass microspheres to generate –Si–O–Si–, some aluminum ions form metal coordination bonds with the oxygen atoms in the hydroxyl groups on the surface of the hollow glass microspheres. This allows the aluminate coupling agent to be effectively grafted onto the surface of the hollow glass microspheres. The aluminum, the central metal atom in the aluminate coupling agent, is a trivalent metal with two organic reactive groups, exhibiting better compatibility with the polymer emulsion compared to the titanate coupling agent. This results in a denser coating structure, thereby improving its high-temperature resistance and aging resistance.

Claims

1. A high-temperature resistant thermal insulation coating, characterized in that: By weight, it includes 100-140 parts of silicone-modified acrylic aqueous dispersion, 10-30 parts of modified hollow glass microspheres, 10-30 parts of curing agent, 5-10 parts of nano-reflective powder, 2-4 parts of additives, and 20-40 parts of water. The organosilicon-modified acrylic aqueous dispersion was prepared by the following method: By weight, under nitrogen protection, 100-125 parts of solvent are heated to 110-140℃. A mixture of 15-20 parts of glycidyl acrylate, 15-20 parts of methyl methacrylate, 15-20 parts of benzoyl acrylate, 15-20 parts of acrylic acid, and 1-2 parts of azobisisobutyronitrile is added dropwise to the solvent over 1-3 hours. After the addition is complete, 5-15 parts of dimethylphenylvinylsilane are added over 5-15 minutes, along with 0.1-1 parts of initiator. The reaction is carried out at 110-140℃ and 600-800 rpm for 2-4 hours. The temperature is then lowered to 60-80℃, 120-180 parts of water are added, and the mixture is stirred at 600-800 rpm for 5-10 minutes. Diethanolamine is added to adjust the pH to 6-8, yielding an organosilicon-modified acrylic acid aqueous dispersion. The modified hollow glass microspheres were prepared by the following method: By weight, 10-30 parts of hollow glass microspheres are dried at 100-140℃ for 2-4 hours, then added to 100-150 parts of ethanol. The mixture is stirred at 50-70℃ and 600-800 rpm for 5-10 minutes. Then, 1-3 parts of aluminate coupling agent are added and reacted for 20-40 minutes. The mixture is then filtered. The resulting hollow glass microspheres are dried at 100-140℃ for 2-4 hours and then passed through a 200-mesh filter. The mixture is then sealed to obtain modified hollow glass microspheres.

2. The high-temperature resistant thermal insulation coating as described in claim 1, characterized in that: The curing agent is at least one of isocyanate and aziridine.

3. The high-temperature resistant thermal insulation coating as described in claim 1, characterized in that: The nano-reflective powder is at least one of nano-titanium dioxide, nano-zinc oxide, and nano-silica.

4. The high-temperature resistant thermal insulation coating as described in claim 1, characterized in that: The additive is at least one of defoamer, dispersant, and antioxidant.

5. The method for preparing the high-temperature resistant thermal insulation coating according to any one of claims 1-4, characterized in that, The synthesis steps include the following: Step 1: Mix 100-140 parts of silicone-modified acrylic aqueous dispersion and 10-30 parts of modified hollow glass microspheres evenly and set aside. Step 2: Mix 10-30 parts curing agent, 2-4 parts additives, 5-10 parts nano-reflective powder and 20-40 parts water until homogeneous and set aside. Step 3: Stir and mix the mixture obtained in Step 1 and Step 2 until homogeneous to obtain a high-temperature resistant thermal insulation coating; The above portions are by weight.

6. The application of the high-temperature resistant thermal insulation coating as described in any one of claims 1-5 in petrochemical pipelines.

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