Water-based high-temperature-resistant corrosion-resistant heat-insulating coating and preparation method thereof

Abstract

The invention relates to a water-based high-temperature-resistant corrosion-resistant heat-insulating coating and a preparation method thereof, and belongs to the technical field of functional coatings. The preparation method comprises the following steps: by taking epoxy resin emulsion, functionalized POSS, anticorrosive filler graphene dispersion liquid, composite heat-insulating filler and auxiliaries as raw materials, shearing and dispersing at a high speed, adding a curing agent and water, stirring at a low speed, and uniformly mixing. The coating has the characteristics of high temperature resistance (heat resistance time at 250 DEG C is not less than 240 hours), corrosion resistance (salt spray test is not less than 2300 hours), heat insulation (temperature difference is not less than 15 DEG C) and environmental protection, and is suitable for protection in severe environments such as petrochemical storage tanks and metal structures.

Description

Technical Field

[0001] This invention relates to a water-based high-temperature resistant anti-corrosion and heat-insulating coating and its preparation method, which is particularly suitable for long-term protection of metal substrates in high-temperature and corrosive environments, and belongs to the field of functional coating technology. Background Technology

[0002] With societal development, energy and environmental issues have become a major focus of public attention. In the coatings industry, thermal insulation coatings, as a new type of functional coating, offer advantages such as heat insulation and energy saving, environmental friendliness, and ease of application, attracting increasing attention in fields such as construction, chemical engineering, transportation, and aerospace. Among these, composite thermal insulation coatings are currently a hot research topic in the field. Composite thermal insulation coatings, containing functional fillers with low thermal conductivity, high reflectivity, and high emissivity, exhibit excellent thermal insulation performance.

[0003] In the petrochemical, energy, and transportation sectors, metal equipment is exposed to high temperatures and corrosive environments for extended periods, necessitating highly efficient protective coatings. However, ordinary heat-insulating coatings generally suffer from insufficient corrosion resistance. While silicone resin coatings offer good heat resistance, they often require high-temperature curing and lack flexibility. Epoxy resin coatings exhibit excellent corrosion resistance and possess advantages such as high strength, high viscosity, low shrinkage, and strong adhesion; however, their temperature resistance is typically limited to below 150℃.

[0004] In recent years, the application of nanomaterials has provided new avenues for coating modification. POSS (porcine silsesquioxane) is an organosilicon monomer that combines organic and inorganic properties. Modifying polymer materials using POSS can significantly improve their overall performance. Studies have shown that POSS, as a modifier, can form a three-dimensional network structure with POSS as its core in polymer materials, improving the crosslinking structure and increasing the crosslinking density, thereby enhancing the polymer's mechanical properties, thermal stability, and corrosion resistance. Patent CN116200102B discloses a POSS-hybrid epoxy anticorrosive coating that increases crosslinking density through POSS, but it does not address the improvement of thermal insulation performance. While graphene / polyaniline-doped coatings improve heat resistance and corrosion resistance, the process is complex and costly.

[0005] Therefore, developing a multifunctional coating that integrates high temperature resistance, corrosion resistance, heat insulation, and environmental protection has become an urgent need for the coating industry. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating that can provide protection in harsh environments.

[0007] The technical solution adopted in this invention is as follows: A water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating is prepared by mixing the following raw materials in the indicated weight ratios: 20-40 parts of epoxy resin emulsion 2-10 functionalized POSS 1-5 parts of anti-corrosion filler graphene oxide dispersion. 10-20 parts of composite thermal insulation filler 5-15 parts of curing agent 1-5 parts of auxiliary agent 10-30 parts deionized water.

[0008] The preferred weight ratio of the anti-corrosion filler graphene dispersion to the composite thermal insulation filler is 1:3-10.

[0009] The functionalized POSS mentioned above is an amino-type POSS, preferably aminopropyl POSS or aminophenyl POSS.

[0010] The solid content of the epoxy resin emulsions mentioned above is 30%-45%.

[0011] The graphene oxide dispersion has a concentration of 5-10 mg / mL.

[0012] The composite thermal insulation filler is composed of a mixture of fillers with low thermal conductivity, high reflectivity, and high emissivity, respectively. The fillers are selected from ceramic microspheres, silica aerogel, TiO2, ZrO2, and SiC; preferably, ceramic microspheres and TiO2 are mixed together. 2、 SiC composite; further optimization of ceramic microspheres and TiO2 2、 SiC is composited at a mass ratio of 4:2:1.

[0013] The curing agent is a latent amine curing agent, preferably modified dicyandiamide or a microencapsulated curing agent.

[0014] The aforementioned additives include water-based dispersants (such as BYK190, BYK2012, EFKA4575, etc.) and water-based defoamers (such as DIG 901W, DIG 904W, etc.).

[0015] The preparation method of the above-mentioned water-based high-temperature resistant, anti-corrosion, and heat-insulating coating includes the following steps: Functionalized POSS is mixed with epoxy resin emulsion according to the formula and reacted at 60-80℃ for 1-2 hours to obtain POSS modified epoxy resin; additives, graphene oxide dispersion and composite heat insulation filler are added to POSS modified epoxy resin in sequence and dispersed by high-speed shear for 25-35 minutes; then curing agent and water are added and stirred at low speed until uniform.

[0016] The beneficial effects of this invention are: The functionalized POSS used is an amino-type POSS (such as aminopropyl POSS, aminophenyl POSS, etc.). As a modifier, it can be chemically bonded into the epoxy resin network to form a three-dimensional cross-linked structure, significantly improving the thermal stability and mechanical properties of the coating. The composite thermal insulation filler is composed of several fillers with low thermal conductivity, high reflectivity, and high emissivity, achieving efficient thermal insulation through a triple mechanism of reflection, radiation, and barrier. The anti-corrosion filler is a graphene oxide dispersion, whose synergistic effect with POSS can significantly enhance the anti-corrosion performance of the coating. The curing agent is a latent amine curing agent (such as modified dicyandiamide, microencapsulated curing agent, etc.), which can be stored for a long time after being mixed with the epoxy emulsion.

[0017] This invention provides a water-based, environmentally friendly coating that also possesses high-temperature resistance, excellent corrosion resistance, and high-efficiency thermal insulation properties. High-temperature resistance: The coating exhibits thermal stability at 250℃ / 240h without cracking, peeling, or blistering. Corrosion resistance: The synergistic effect of graphene oxide and POSS allows for salt spray testing time exceeding 2300 hours. Thermal insulation: The composite filler system reduces the surface temperature of the metal substrate by more than 15℃. Environmental friendliness: Using water as the dispersion medium, it meets green coating standards.

[0018] This invention utilizes a ternary synergistic design of POSS-graphene-composite filler to prepare a water-based coating with excellent properties such as high-temperature resistance, corrosion resistance, and thermal insulation. This coating can be used for protection in harsh environments such as oil storage tanks and bridge steel structures, demonstrating significant environmental and economic value. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments.

[0020] Example 1: (1) A method for preparing a water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating: 5g of octaaminopropyl POSS was mixed with 35g of epoxy resin emulsion with a solid content of 40% and reacted at 70℃ for 1 hour to obtain POSS-modified epoxy resin. 1g of dispersant BYK-190, 1g of defoamer DIG 901W, 2g of graphene oxide dispersion with a concentration of 5mg / mL, and 20g of composite heat-insulating filler (ceramic microspheres:TiO2:SiC=4:2:1) were added to the POSS-modified epoxy resin and dispersed under high speed for 30 minutes. 10g of curing agent EH-3842 and 26g of water were added and stirred at low speed for 10 minutes until homogeneous.

[0021] The prepared anti-corrosion and heat-insulating coating was sprayed onto a steel plate, with the coating thickness controlled at 50±5μm. It was dried at 60℃ and then cured at 120℃ for 0.5~1h.

[0022] (2) Performance testing: Heat resistance test (250℃×240h, GB / T 1735): No cracking, peeling, blistering, etc. Salt spray test (GB / T1771-2007): 2300h; Thermal insulation temperature difference (HG / T4341-2012): 16℃.

[0023] Example 2: (1) A method for preparing a water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating: 5g of octaaminophenyl POSS was mixed with 35g of epoxy resin emulsion with a solid content of 40% and reacted at 80℃ for 2 hours to obtain POSS-modified epoxy resin. 1g of dispersant BYK2012, 1g of defoamer DIG 901W, 2g of graphene oxide dispersion with a concentration of 5mg / mL, and 20g of composite heat-insulating filler (ceramic microspheres:TiO2:SiC=4:2:1) were added to the POSS-modified epoxy resin and dispersed under high speed for 30 minutes. 10g of curing agent EH-3842 and 26g of water were added and stirred at low speed for 10 minutes until homogeneous.

[0024] The prepared anti-corrosion and heat-insulating coating was sprayed onto a steel plate, with the coating thickness controlled at 50±5μm. It was dried at 60℃ and then cured at 120℃ for 0.5~1h.

[0025] (2) Performance testing: Heat resistance test (250℃×240h, GB / T 1735): No cracking, peeling, blistering, etc. Salt spray test (GB / T1771-2007): 2330h; Thermal insulation temperature difference (HG / T4341-2012): 18℃.

[0026] Example 3: (1) A method for preparing a water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating: 10g of octaaminopropyl POSS was mixed with 35g of epoxy resin emulsion with a solid content of 40% and reacted at 70℃ for 1.5 hours to obtain POSS-modified epoxy resin. Then, 1g of dispersant BYK-190, 1g of defoamer DIG 901W, 5g of graphene oxide dispersion with a concentration of 10mg / mL, and 18g of composite heat-insulating filler (ceramic microspheres:TiO2:SiC=4:2:1) were added sequentially, and the mixture was dispersed by high-speed shearing for 30 minutes. Finally, 10g of curing agent EH-3842 and 20g of water were added, and the mixture was stirred at low speed for 10 minutes until homogeneous.

[0027] The prepared anti-corrosion and heat-insulating coating was sprayed onto a steel plate, with the coating thickness controlled at 50±5μm. It was dried at 60℃ and then cured at 120℃ for 0.5~1h.

[0028] (2) Performance testing: Heat resistance test (250℃×240h, GB / T 1735): No cracking, peeling, blistering, etc. Salt spray test (GB / T1771-2007): 2400h; Thermal insulation temperature difference (HG / T4341-2012): 18℃.

[0029] Example 4: (1) A method for preparing a water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating: 5g of octaaminopropyl POSS and 5g of octaaminophenyl POSS were mixed with 35g of epoxy resin emulsion with a solid content of 40% and reacted at 80℃ for 1.5 hours to obtain POSS-modified epoxy resin. Then, 1g of dispersant BYK2012, 1g of defoamer DIG901W, 5g of graphene oxide dispersion with a concentration of 8mg / mL, and 18g of composite thermal insulation filler (aerogel:TiO2:SiC=4:2:1) were added sequentially, and the mixture was dispersed by high-speed shearing for 30 minutes. Finally, 10g of curing agent EH-3842 and 20g of water were added, and the mixture was stirred at low speed for 10 minutes until homogeneous.

[0030] The prepared anti-corrosion and heat-insulating coating was sprayed onto a steel plate, with the coating thickness controlled at 50±5μm. It was dried at 60℃ and then cured at 120℃ for 0.5~1h.

[0031] (2) Performance testing: Heat resistance test (250℃×240h, GB / T 1735): No cracking, peeling, blistering, etc. Salt spray test (GB / T1771-2007): 2360h; Thermal insulation temperature difference (HG / T4341-2012): 16℃.

[0032] Example 5: (1) A method for preparing a water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating: 5g of octaaminopropyl POSS was mixed with 40g of epoxy resin emulsion with a solid content of 35% and reacted at 70℃ for 1.5 hours to obtain POSS-modified epoxy resin. Then, 1g of dispersant BYK-190, 1g of defoamer DIG 901W, 5g of graphene oxide dispersion with a concentration of 5mg / mL, and 15g of composite thermal insulation filler (aerogel:TiO2:SiC=4:2:1) were added sequentially, and the mixture was dispersed under high speed for 30 minutes. Finally, 13g of curing agent EH-3842 and 20g of water were added, and the mixture was stirred at low speed for 10 minutes until homogeneous.

[0033] The prepared anti-corrosion and heat-insulating coating was sprayed onto a steel plate, with the coating thickness controlled at 50±5μm. It was dried at 60℃ and then cured at 120℃ for 0.5~1h.

[0034] (2) Performance testing: Heat resistance test (250℃×240h, GB / T 1735): No cracking, peeling, blistering, etc. Salt spray test (GB / T1771-2007): 2300h; Thermal insulation temperature difference (HG / T4341-2012): 15℃.

[0035] The above is a further description of the present invention in conjunction with specific embodiments, and the scope of protection of the present invention is not limited thereto.

Claims

1. A water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating, characterized in that, It is made by mixing the following raw materials in the following weight ratios: 20-40 parts of epoxy resin emulsion 2-10 functionalized POSS 1-5 parts of anti-corrosion filler graphene oxide dispersion. 10-20 parts of composite thermal insulation filler 5-15 parts of curing agent 1-5 parts of auxiliary agent 10-30 parts deionized water.

2. The water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating according to claim 1, characterized in that, The weight ratio of the anti-corrosion filler graphene dispersion to the composite heat insulation filler is 1:3-10.

3. The water-based high-temperature resistant, anti-corrosion, and heat-insulating coating according to claim 1, characterized in that, The functionalized POSS is an amino-type POSS.

4. The water-based high-temperature resistant, anti-corrosion, and heat-insulating coating according to claim 1, characterized in that, The epoxy resin emulsion has a solid content of 30%-45%.

5. A water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating according to claim 1, characterized in that, The graphene oxide dispersion has a concentration of 5-10 mg / mL.

6. The water-based high-temperature resistant, anti-corrosion, and heat-insulating coating according to claim 1, characterized in that, The composite thermal insulation filler is composed of fillers with low thermal conductivity, high reflectivity and high emissivity, respectively. The fillers are selected from ceramic microspheres, silica aerogel, TiO2, ZrO2 and SiC.

7. The water-based high-temperature resistant, anti-corrosion, and heat-insulating coating according to claim 6, characterized in that, The composite thermal insulation filler consists of ceramic microspheres and TiO2. 2、 SiC composite.

8. The water-based high-temperature resistant, corrosion-resistant, and heat-insulating coating according to claim 7, characterized in that, The composite thermal insulation filler consists of ceramic microspheres and TiO2. 2、 SiC is composited at a mass ratio of 4:2:

1.

9. The water-based high-temperature resistant, anti-corrosion, and heat-insulating coating according to claim 1, characterized in that, The curing agent is a latent amine curing agent, and the additives are an aqueous dispersant and an aqueous defoamer.

10. The method for preparing the water-based high-temperature resistant, anti-corrosion, and heat-insulating coating according to any one of claims 1-9, characterized in that, The steps include the following: mixing functionalized POSS with epoxy resin emulsion according to the formula, reacting at 60-80℃ for 1-2 hours to obtain POSS modified epoxy resin; adding additives, graphene oxide dispersion and composite heat insulation filler to POSS modified epoxy resin in sequence, and dispersing at high speed for 25-35 minutes; then adding curing agent and water, stirring at low speed until uniformly mixed.