Modified epoxy resin waterproof coating with high environment-friendly flexibility and preparation method of modified epoxy resin waterproof coating

Abstract

The invention relates to the technical field of coatings, and discloses a modified epoxy resin waterproof coating with high environmental protection flexibility and a preparation method thereof, and the modified epoxy resin waterproof coating comprises the following components by mass: 40-50 parts of modified epoxy resin; 10 to 15 parts by mass of polyurethane; 8 to 12 parts by mass of isocyanate; 15-20 parts by mass of an asymmetric amino curing agent; 2-5 parts by mass of nano graphene; 3-6 parts by mass of a polyester toughening agent; 1-2 parts by mass of a metal organic catalyst; 0.5-1 part by mass of a defoaming agent; and 2-3 parts by mass of an accelerant. The metal organic catalyst and polyurethane are combined, so that the curing speed of the coating is increased. Through the improvement, the curing time of the coating after construction is greatly shortened, and compared with the problem that the curing time is too long in the prior art, the construction efficiency is improved, the unstable performance caused by incomplete curing is reduced, and high-quality and efficient completion of the coating is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, specifically to a modified epoxy resin waterproof coating with high environmental protection and flexibility and its preparation method. Background Art

[0002] In the field of waterproof coatings, epoxy resins are widely used in building waterproofing, floor coatings, and various protective coatings due to their excellent adhesion performance, chemical stability, and mechanical strength. However, traditional epoxy resin coatings still have many technical limitations in practical applications, which affect their promotion and long-term use effects.

[0003] Firstly, after curing, epoxy resins often exhibit high hardness and brittleness, lacking sufficient flexibility, which causes them to crack easily under temperature changes or mechanical stress, thereby affecting the durability of the coating. This characteristic makes it difficult for epoxy resin coatings to maintain long-term stability under conditions such as thermal expansion and contraction of the substrate or mechanical deformation. Especially in application scenarios where a certain elasticity is required to adapt to substrate deformation, traditional epoxy resin coatings cannot effectively buffer external forces, easily generate cracks, and reduce the protection effect.

[0004] Secondly, the curing speed of existing epoxy resin coatings is relatively slow, and the construction period is long, which directly affects the construction efficiency and project progress. In practical applications, the curing of epoxy resins usually relies on amine curing agents or other catalytic systems. However, while ensuring the curing effect, these systems often have the problem of a long curing time. In a humid and hot environment, the curing process may be affected by environmental factors, resulting in uneven curing of the coating or even the generation of internal stress, further weakening the physical properties of the coating. The long curing process not only prolongs the construction period but also increases the requirements for construction environmental conditions, restricting the applicability of the coating.

[0005] In addition, traditional epoxy resin coatings have insufficient strength and poor stability in the daily environment. Especially in high-temperature environments or when exposed to ultraviolet rays and high humidity for a long time, their anti-aging performance is greatly limited. Existing enhancement and modification methods, such as adding inorganic fillers, glass fibers, etc., although they can improve the durability of the coating to a certain extent, often sacrifice flexibility or processing performance and cannot simultaneously take into account crack resistance, anti-aging performance, and construction convenience.

[0006] Therefore, the present invention proposes a modified epoxy resin waterproof coating with high environmental protection and flexibility and its preparation method to solve the deficiencies of the existing technology. Summary of the Invention

[0007] Aiming at the deficiencies of the existing technology, the present invention provides a modified epoxy resin waterproof coating with high environmental protection and flexibility and its preparation method, which solves the problems of too long curing time, insufficient flexibility, and poor anti-aging performance of traditional epoxy resin waterproof coatings.

[0008] To achieve the above objectives, the present invention is realized through the following technical solutions: a modified epoxy resin waterproof coating with high environmental protection flexibility, comprising the following components in parts by mass: 40 - 50 parts by mass of modified epoxy resin; 10 - 15 parts by mass of polyurethane; 8 - 12 parts by mass of isocyanate; 15 - 20 parts by mass of asymmetric amino curing agent; 2 - 5 parts by mass of nano graphene; 3 - 6 parts by mass of polyester toughening agent; 1 - 2 parts by mass of metal organic catalyst; 0.5 - 1 part by mass of defoaming agent; 2 - 3 parts by mass of accelerator.

[0009] Modified epoxy resin The modified epoxy resin is mainly obtained through the copolymerization reaction of epoxy resin and amino resin, having good corrosion resistance and excellent mechanical properties. It is the base resin of the entire waterproof coating system, with good adhesion, abrasion resistance, and high curing performance. The reactivity of epoxy resin, epoxy resin contains active epoxy groups, which can undergo cross-linking reactions with curing agents to form a cross-linked structure, enhancing the weather resistance and water resistance of the coating.

[0010] Copolymerization with amino resin, through copolymerization with amino resin, the flexibility of epoxy resin is improved, and the ductility and crack resistance of the coating are improved. The addition of amino resin can effectively increase the elasticity of epoxy resin, thereby enhancing the impact resistance and anti-peeling performance of the coating.

[0011] Polyurethane Polyurethane is an important reinforcing material. Through the copolymerization reaction with epoxy resin, polyurethane can enhance the flexibility and aging resistance of the coating.

[0012] Enhanced flexibility, polyurethane itself has high flexibility and abrasion resistance. After copolymerization with epoxy resin, it can significantly improve the mechanical strength of the coating and enhance its impact resistance and abrasion resistance.

[0013] Aging resistance, the amino and isocyanate groups in the polyurethane structure can absorb moisture and react with oxygen in the air, reducing the aging rate of the coating caused by ultraviolet radiation and increasing the service life of the coating.

[0014] Isocyanate Isocyanate is used to react with epoxy resin and other curing agents to form a cross-linked structure. Its function is to accelerate the curing reaction and improve the chemical resistance of the coating.

[0015] Reactivity, isocyanate has active isocyanate groups (-NCO), which can react with substances containing amino, hydroxyl, or other reactive groups to form a strong cross-linked structure in the epoxy resin system.

[0016] Curing acceleration: The addition of isocyanates can significantly accelerate the curing process of coatings. Especially in humid or low-temperature environments, it can also effectively promote the curing of coatings and reduce the waiting time after construction.

[0017] Asymmetric amino curing agent Asymmetric amino curing agents refer to polyamide or cycloaliphatic amine curing agents, which are commonly used to react with epoxy resins. Their addition can improve the high-temperature resistance, corrosion resistance, and faster curing reaction of coatings.

[0018] Reacting with epoxy resin: In the reaction with epoxy resin, the amino groups in the asymmetric amino curing agent react with the epoxy groups in the epoxy resin to form a stable cross-linked network, improving the water resistance and mechanical strength of the coating.

[0019] Curing time adjustment: Compared with traditional amine curing agents, asymmetric amino curing agents have stronger reactivity, which can shorten the curing time, increase the cross-linking density of the final coating, and enhance its physical properties.

[0020] Nanographene As a reinforcing material, nanographene can significantly improve the crack resistance, anti-aging property, and thermal stability of coatings. Its addition can increase the mechanical properties of coatings and improve durability.

[0021] Reinforcing material: Nanographene has an extremely high specific surface area and excellent mechanical properties. Its addition can significantly enhance the structural strength of coatings, improving their crack resistance and impact resistance.

[0022] Improved thermal conductivity: Nanographene has extremely high thermal conductivity, which can evenly distribute heat, accelerate the curing reaction of the coating, and improve the overall heat resistance of the coating.

[0023] Improved anti-aging property: Nanographene can effectively inhibit the damage of ultraviolet rays to the coating and enhance the anti-ultraviolet aging ability of the coating.

[0024] Polyester toughening agent Polyester toughening agents mainly refer to copolymers of polybutylene terephthalate and polyether polyol. Their function is to enhance the flexibility and impact resistance of coatings and improve the crack resistance of coatings.

[0025] Improved flexibility: The addition of polyester toughening agents makes the epoxy resin coating more flexible after curing, reducing the probability of cracks in the coating due to external forces.

[0026] Enhanced impact resistance: Polyester toughening agents can improve the impact resistance of coatings and enhance the bearing capacity of coatings against mechanical impacts during construction.

[0027] Metal-organic catalyst Metal-organic catalysts (such as cobalt catalysts and bismuth catalysts) are used to accelerate the curing reaction of epoxy resins, improving the curing rate and construction efficiency of coatings.

[0028] Catalytic action: Metal-organic catalysts can significantly increase the reaction rate between epoxy resins and curing agents. Especially at lower temperatures, they can promote the rapid progress of cross-linking reactions, reducing the drying and curing time of coatings.

[0029] Increasing cross-linking density: The catalyst can promote more epoxy groups to react with the curing agent, thereby increasing the cross-linking density and enhancing the physical properties of the coating.

[0030] Defoamer Defoamers are used to remove air bubbles in the coating system, preventing the formation of pores or foams during the curing process of the coating, which may affect the flatness and density of the coating.

[0031] Inhibiting bubble formation: Defoamers can effectively reduce the surface tension of the coating system, inhibiting the formation and expansion of bubbles, ensuring a smooth and flat coating surface.

[0032] Improving coating density: Removing air bubbles helps to improve the density of the coating, avoiding weak points caused by air bubbles inside the coating, and enhancing waterproof performance and durability.

[0033] Accelerator Accelerators (such as copolymers of organophosphorus compounds and quaternary ammonium salts) are used to accelerate the curing reaction and adjust the viscosity and fluidity of the coating.

[0034] Accelerating curing: Accelerators can accelerate the chemical reaction between epoxy resins and curing agents, enabling the coating to reach curing in a shorter time.

[0035] Improving fluidity: By adjusting the viscosity of the coating, accelerators help to improve the workability of the coating. Especially during large-area construction, they can ensure uniform coating of the coating, avoiding uneven coatings.

[0036] Preferably, the modified epoxy resin is a copolymer of epoxy resin and polyurethane, and the mass ratio of epoxy resin to polyurethane is 3:1 to 2:1.

[0037] Epoxy resin provides the corrosion resistance, strength, and adhesion of the coating, while polyurethane imparts flexibility, impact resistance, and crack resistance to the coating. Through copolymerization, the properties of the two are complementary, enhancing the comprehensive performance of the coating.

[0038] The epoxy groups in the epoxy resin react with the amino or hydroxyl groups of the polyurethane to form a cross-linked network structure, enhancing the strength and corrosion resistance of the coating. The flexible molecular chain structure of the polyurethane enhances the ductility and crack resistance of the coating, preventing the coating from cracking under external forces or temperature changes. When the mass ratio is 3:1, the coating has higher hardness and stronger corrosion resistance; when it is 2:1, the flexibility and crack resistance are better.

[0039] Preferably, the asymmetric amino curing agent is one of polyamide-based and cycloaliphatic amine-based curing agents.

[0040] The asymmetric amino curing agent is selected from polyamide-based or cycloaliphatic amine-based curing agents and is used to react with the epoxy resin to accelerate its curing process. Polyamide-based curing agents are composed of amino groups and amide groups, and cycloaliphatic amine-based curing agents contain cyclic amino structures. Both can improve the chemical resistance, high-temperature resistance and water resistance of the coating.

[0041] The polyamide-based curing agent forms a strong cross-linked structure through the addition reaction of amino groups and epoxy groups, enhancing the mechanical strength and corrosion resistance of the coating.

[0042] The cyclic amino structure of the cycloaliphatic amine-based curing agent has high reactivity, accelerating the curing and improving the anti-aging and ultraviolet resistance of the coating.

[0043] The high reactivity of the asymmetric amino curing agent accelerates the curing process, shortening the construction time and improving the overall performance of the coating.

[0044] Preferably, the metal-organic catalyst is one of cobalt catalysts and bismuth catalysts.

[0045] Metal-organic catalysts, such as cobalt catalysts or bismuth catalysts, are used to accelerate the curing reaction of epoxy resins. Cobalt and bismuth, as catalysts, can increase the reaction rate between epoxy resins and curing agents, thus accelerating the curing process and reducing the waiting time after construction.

[0046] Cobalt catalysts can lower the activation energy of the reaction by catalyzing the reaction between epoxy resins and curing agents, promoting the ring-opening reaction of epoxy groups, and thus accelerating the curing process. Cobalt catalysts can also promote curing at lower temperatures, improving construction efficiency.

[0047] Bismuth catalysts accelerate the reaction between epoxy resins and hardeners by providing electron support in the curing reaction, especially in environments with higher humidity or lower temperatures, maintaining the stability of the curing rate, and enhancing the weather resistance and mechanical properties of the coating.

[0048] Preferably, the polyester toughening agent is a copolymer of polybutylene terephthalate and polyether polyol, and the mass ratio of polybutylene terephthalate to polyether polyol is 3:1 to 2:1.

[0049] The polyester toughening agent is formed by copolymerizing PBT and polyether polyol, and at the same time, the mass ratio of the two is controlled to be 3:1 to 2:1, so as to improve the toughness and impact resistance of the coating while maintaining good mechanical strength and weather resistance.

[0050] The PBT structure provides high strength. PBT has good crystallinity, endowing the coating with high rigidity, heat resistance and chemical resistance, while enhancing the mechanical strength and abrasion resistance of the material.

[0051] The polyether polyol provides flexibility. The molecular chain of the polyether polyol has high flexibility, which can improve the ductility of the coating, increase the impact absorption capacity, reduce brittleness and improve crack resistance.

[0052] The copolymerization balances the rigid and flexible properties. Within the mass ratio range of 3:1 to 2:1, it ensures the balance of rigidity and toughness, enabling the coating to have excellent mechanical strength and resistance to external impacts and temperature changes, thereby improving durability and construction adaptability.

[0053] Preferably, the promoter is a copolymer of an organophosphorus compound and a quaternary ammonium salt, and the mass ratio of the organophosphorus compound to the quaternary ammonium salt is 3:1 to 2:1.

[0054] This promoter is prepared by copolymerizing an organophosphorus compound and a quaternary ammonium salt, and the mass ratio is controlled to be 3:1 to 2:1, which is used to increase the curing rate of epoxy resin and enhance the stability of the curing network.

[0055] The organophosphorus compound has excellent catalytic action, can reduce the activation energy of the curing reaction, accelerate the ring-opening reaction of epoxy groups, and at the same time improve heat resistance and chemical corrosion resistance.

[0056] The quaternary ammonium salt, as a phase transfer catalyst, improves the compatibility between epoxy resin and curing agent, enhances ionic conductivity, accelerates the cross-linking reaction, and improves curing uniformity and final mechanical properties.

[0057] The copolymerization effect, with a mass ratio of 3:1 to 2:1, can achieve the balanced performance of the promoter, which can not only improve the curing efficiency, but also optimize the mechanical strength and durability after curing, and avoid problems such as uneven curing or brittleness caused by excessive catalysis.

[0058] The present invention also provides a preparation method of a modified epoxy resin waterproof coating with high environmental protection flexibility, including the following steps: S1: Mix epoxy resin and amino resin in a mass ratio of 3:1 to 2:1, and continuously stir at a temperature of 30°C to 50°C for 2 to 4 hours to prepare modified epoxy resin; Mix epoxy resin and amino resin in a mass ratio of 3:1 to 2:1 and continuously stir at a temperature of 30°C to 50°C for 2 to 4 hours. This process ensures the full mixing of epoxy resin and amino resin, makes the chemical structures of the two evenly distributed, forms a preliminary copolymerization system, improves the flexibility and durability of the coating, and at the same time avoids uneven performance caused by local phase separation.

[0059] S2: During the stirring process of preparing the modified epoxy resin, add isocyanate and asymmetric amino curing agent and continuously stir at a temperature of 45°C to 60°C for 1 to 3 hours; During the stirring process of S1, gradually add isocyanate and asymmetric amino curing agent, raise the temperature to 45°C to 60°C, and continuously stir for 1 to 3 hours. Isocyanate can further react with polyurethane to increase the crosslinking degree of the system, enhance chemical resistance and water resistance; the asymmetric amino curing agent improves the curing rate and the strength of the coating by accelerating the curing of epoxy groups, ensuring the durability of the final product.

[0060] S3: Mix polybutylene terephthalate and polyether polyol in a mass ratio of 3:1 to 2:1, add nano-graphene and metal organic catalyst, and after stirring at 40°C to 55°C for 1 to 2 hours, slowly add it to the mixture of S2 and continue to stir until uniform; Mix polybutylene terephthalate (PBT) and polyether polyol in a mass ratio of 3:1 to 2:1 and stir at 40°C to 55°C for 1 to 2 hours to ensure full fusion of the two and enhance the toughening effect. Subsequently, add nano-graphene to enhance conductivity, abrasion resistance and corrosion resistance, and at the same time add metal organic catalyst (such as cobalt catalyst or bismuth catalyst) to promote the curing reaction of epoxy resin and improve construction adaptability. After stirring evenly, slowly add it to the mixture of S2 and continue to stir until the system is uniform and stable.

[0061] S4: Add defoamer and accelerator to the mixture of S3, adjust the viscosity and fluidity of the mixture, and stir at a temperature of 25°C to 35°C for 30 to 60 minutes to make all components evenly dispersed; In the mixture of S3, add defoamer and accelerator to improve the construction performance of the coating. The defoamer can effectively eliminate bubbles, prevent defects during the curing process, and improve the denseness of the coating film. The accelerator (copolymerized by organic phosphorus compound and quaternary ammonium salt, mass ratio 3:1 to 2:1) further optimizes the curing rate and makes the curing process more stable and uniform. Stir at a temperature of 25°C to 35°C for 30 to 60 minutes to ensure that all components are evenly dispersed, and finally form a uniform and stable coating system.

[0062] S5: After uniform mixing, filter and package to complete the preparation of the high-environmental-flexibility modified epoxy resin waterproof coating.

[0063] After uniform mixing, the coating is filtered to remove any possible agglomerated particles, improving the uniformity of the product and the smoothness of the coating. Finally, it is packaged and stored to complete the preparation of the highly environmentally friendly flexible modified epoxy resin waterproof coating. This coating has excellent flexibility, waterproofness, chemical resistance, and construction adaptability, and is suitable for a variety of building waterproofing projects.

[0064] Preferably, the stirring is carried out using a high-speed shear mixer with a rotation speed controlled at 500 - 1000 rpm for the full mixing of the modified epoxy resin and polyurethane.

[0065] During the mixing process of the modified epoxy resin and polyurethane, a high-speed shear mixer is used and the rotation speed is controlled at 500 - 1000 rpm to ensure full mixing of the two, forming a uniform copolymer system, avoiding phase separation or uneven component distribution, and thus improving the stability and performance of the final coating.

[0066] High-speed shearing action. High-speed shear stirring can break droplets and polymer aggregates, enabling the full dispersion of epoxy resin and polyurethane at the microscale, forming a stable emulsified or uniformly dissolved state, and improving compatibility.

[0067] Rotation speed control. A rotation speed range of 500 - 1000 rpm can ensure that neither excessive bubbles are generated to affect product quality, nor can it provide sufficient shearing force to form a uniform molecular structure of the copolymer, guaranteeing the mechanical properties and durability of the coating.

[0068] Enhancing system stability. Through efficient stirring, the interaction between epoxy groups and polyurethane can be promoted, improving the denseness of the cured coating, and enhancing water resistance, chemical resistance, and weather resistance.

[0069] Preferably, the addition of the nano-graphene adopts ultrasonic dispersion technology and is dispersed for 30 - 60 minutes in an ultrasonic environment with a power of 200 - 500 W and a frequency of 20 - 40 kHz.

[0070] During the preparation process, ultrasonic dispersion technology is used to pre-treat the nano-graphene and disperse it for 30 - 60 minutes in an ultrasonic environment with a power of 200 - 500 W and a frequency of 20 - 40 kHz to ensure the uniform distribution of nano-graphene in the coating system and enhance its reinforcing performance.

[0071] Ultrasonic cavitation effect. When ultrasonic waves propagate in a liquid, local high-temperature and high-pressure cavitation phenomena will occur, which can break the agglomeration of nano-graphene, make it uniformly dispersed in the matrix, avoid sedimentation and aggregation, and improve stability.

[0072] Power and frequency regulation, a power range of 200 - 500W provides sufficient energy to disperse nanoparticles, while an ultrasonic frequency of 20 - 40kHz ensures that the layered structure of nano-graphene is not damaged, promotes bonding with the resin matrix, and improves electrical conductivity and wear resistance.

[0073] Enhance coating performance. After uniform dispersion of nano-graphene, it can effectively improve the corrosion resistance, mechanical strength, thermal conductivity and crack resistance of the coating, thereby improving the comprehensive performance of the waterproof coating.

[0074] Preferably, the filtration uses a 300 - 500 mesh stainless steel sieve to remove incompletely dispersed particles or impurities.

[0075] In the final stage of coating preparation, a 300 - 500 mesh stainless steel sieve is used for filtration to remove incompletely dispersed particles or impurities, ensure the uniformity of the coating, and improve the construction quality.

[0076] Fine particle removal. The sieve aperture of 300 - 500 mesh is about 25 - 50 microns, which can effectively filter incompletely dispersed fillers, polymer aggregates or impurities, and prevent uneven particles from affecting the smoothness and adhesion of the coating.

[0077] Improve coating quality. After filtration, a uniform and delicate coating can be obtained, improving the construction performance, and avoiding problems such as clogging of spraying equipment by particles or surface defects such as shrinkage holes and particle deposition.

[0078] Ensure stability. After removing impurities, the long-term stability of the coating can be improved, sedimentation can be prevented, and the wear resistance, waterproofness and weather resistance of the final coating can be enhanced.

[0079] The present invention provides a modified epoxy resin waterproof coating with high environmental protection and flexibility and its preparation method. It has the following beneficial effects: 1. The present invention combines a metal-organic catalyst with polyurethane to accelerate the curing speed of the coating. This improvement significantly shortens the curing time after construction. Compared with the problem of overly long curing time in the prior art, it not only improves the construction efficiency but also reduces the performance instability caused by incomplete curing, ensuring high quality and efficient completion of the coating.

[0080] 2. The present invention successfully improves the crack resistance and high-temperature resistance of the coating by introducing nano-graphene reinforcing materials. Coatings in the prior art often lack sufficient strength in daily environments, while the coatings of the present invention show better crack resistance and high-temperature resistance under these conditions, significantly enhancing their adaptability in complex environments.

[0081] 3. The present invention adopts a technical solution of compounding modified epoxy resin and polyurethane, achieving the technical effects of improving the flexibility and aging resistance of the coating. Compared with the traditional epoxy resin coatings in the prior art, the modified coating greatly improves its brittleness problem, and can still maintain high stability and protection effect after long-term use, avoiding the phenomena of coating cracking and losing function. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 It is a flow chart of the preparation method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0083] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings of the present invention specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0084] Please refer to Figure 1 , Example 1: Component ratio (parts by mass): Modified epoxy resin: 40; Polyurethane: 10; Isocyanate: 15; Asymmetric amino curing agent: 18; Nano-graphene: 2; Polyester toughening agent: 3; Metal organic catalyst: 1; Defoaming agent: 0.5; Accelerator: 2.

[0085] Specific preparation steps: Prepare modified epoxy resin: Put 30 parts by mass of epoxy resin and 10 parts by mass of amino resin into a stirring tank and stir at 30°C. Use a high-speed shear mixer with a rotation speed set at 500 rpm and continuously stir for 2 hours to ensure uniform mixing of the two.

[0086] Add isocyanate and asymmetric amino curing agent: Add 10 parts by mass of isocyanate and 15 parts by mass of asymmetric amino curing agent to the mixture of modified epoxy resin and polyurethane, adjust the temperature to 45°C, and continue stirring for 1 hour to ensure sufficient reaction.

[0087] Add metal organic catalyst, toughening agent and nano-graphene: After treating 2 parts by mass of nano-graphene by ultrasonic dispersion (power 200W, frequency 20kHz, time 30 minutes), slowly add it to the above mixture, and also add 3 parts by mass of polyester toughening agent and 1 part by mass of metal organic catalyst to the above mixture, and continue stirring until uniform.

[0088] Add defoaming agent and accelerator: Add 0.5 parts by mass of defoaming agent and 2 parts by mass of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0089] Filtration and packaging: Filter through a 300-mesh stainless steel sieve to remove insoluble particles, and finally package.

[0090] Example 2: Component ratio (parts by mass): Modified epoxy resin: 50; Polyurethane: 15; Isocyanate: 12; Asymmetric amino curing agent: 20; Nano graphene: 5; Polyester toughening agent: 6; Metal organic catalyst: 2; Defoaming agent: 1; Accelerator: 3.

[0091] Specific preparation steps: Prepare modified epoxy resin: Put 33 parts by mass of epoxy resin and 16 parts by mass of amino resin into a stirring tank and stir at 45°C. Use a high-speed shear mixer with a rotation speed set at 900 rpm and stir for 2.5 hours to ensure uniform mixing of the two.

[0092] Add isocyanate and asymmetric amino curing agent: Add 12 parts by mass of isocyanate and 20 parts by mass of asymmetric amino curing agent to the mixture of epoxy resin and polyurethane, adjust the temperature to 55°C, and continue stirring for 2.5 hours to ensure sufficient reaction.

[0093] Add metal organic catalyst, toughening agent and nano graphene: After treating 5 parts by mass of nano graphene by ultrasonic dispersion (power 450W, frequency 35kHz, time 55 minutes), slowly add it to the above mixture, and also add 6 parts by mass of polyester toughening agent and 2 parts by mass of metal organic catalyst to the above mixture, and continue stirring until uniform.

[0094] Add defoaming agent and accelerator: Add 1 part by mass of defoaming agent and 3 parts by mass of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0095] Filtration and packaging: Filter through a 400-mesh stainless steel sieve to remove insoluble particles, and finally package.

[0096] Example 3: Component ratio (parts by mass): Modified epoxy resin: 45; Polyurethane: 12; Isocyanate: 10; Asymmetric amino curing agent: 17; Nano graphene: 3; Polyester toughening agent: 4; Metal organic catalyst: 1.5; Defoaming agent: 0.8; Accelerator: 2.5.

[0097] Specific preparation steps: Prepare modified epoxy resin: Put 30 parts by mass of epoxy resin and 15 parts by mass of amino resin into a stirring tank and stir at 35°C. Use a high-speed shear mixer with a rotation speed set at 600 rpm and stir for 2 hours to ensure uniform mixing of the two.

[0098] Add isocyanate and asymmetric amino curing agent: Add 10 parts by mass of isocyanate and 17 parts by mass of asymmetric amino curing agent to the mixture of modified epoxy resin and polyurethane, adjust the temperature to 50 °C, and continue stirring for 1 hour to ensure sufficient reaction.

[0099] Add metal-organic catalyst, toughening agent and nano-graphene: After treating 3 parts by mass of nano-graphene by ultrasonic dispersion (power 300 W, frequency 25 kHz, time 40 minutes), slowly add it to the above mixture, and also add 4 parts by mass of polyester toughening agent and 1.5 parts by mass of metal-organic catalyst to the above mixture, and continue stirring until homogeneous.

[0100] Add defoaming agent and accelerator: Add 0.8 parts by mass of defoaming agent and 2.5 parts by mass of accelerator to the above mixture, and stir for 30 minutes to ensure uniform dispersion.

[0101] Filtration and packaging: Filter through a 300-mesh stainless steel sieve to remove insoluble particles, and finally package.

[0102] Example 4: Component ratio (parts by mass): Modified epoxy resin: 48; Polyurethane: 14; Isocyanate: 11; Asymmetric amino curing agent: 19; Nano-graphene: 4; Polyester toughening agent: 5; Metal-organic catalyst: 1.2; Defoaming agent: 0.6; Accelerator: 2.2.

[0103] Specific preparation steps: Prepare modified epoxy resin: Put 35 parts by mass of epoxy resin and 13 parts by mass of amino resin into a stirring tank and stir at 40 °C. Use a high-speed shear mixer with a rotation speed set at 550 rpm and stir for 2 hours to ensure uniform mixing.

[0104] Add isocyanate and asymmetric amino curing agent: Add 11 parts by mass of isocyanate and 19 parts by mass of asymmetric amino curing agent to the mixture of modified epoxy resin and polyurethane, adjust the temperature to 55 °C, and continue stirring for 1.5 hours to ensure sufficient reaction.

[0105] Add metal-organic catalyst, toughening agent and nano-graphene: After treating 4 parts by mass of nano-graphene by ultrasonic dispersion (power 350 W, frequency 30 kHz, time 50 minutes), slowly add it to the above mixture, and also add 5 parts by mass of polyester toughening agent and 1.2 parts by mass of metal-organic catalyst to the above mixture, and continue stirring until homogeneous.

[0106] Add defoaming agent and accelerator: Add 0.6 parts by mass of defoaming agent and 2.2 parts by mass of accelerator to the above mixture, and stir for 30 minutes to ensure uniform dispersion.

[0107] Filtration and packaging: Filter through a 350-mesh stainless steel sieve to remove insoluble particles, and finally package.

[0108] Example 5: Component ratio (parts by mass): Modified epoxy resin: 43; Polyurethane: 13; Isocyanate: 9; Asymmetric amino curing agent: 16; Nano graphene: 3; Polyester toughening agent: 4; Metal organic catalyst: 1; Defoaming agent: 0.7; Accelerator: 2.5.

[0109] Specific preparation steps: Preparation of modified epoxy resin: Put 30 parts by mass of epoxy resin and 13 parts by mass of amino resin into a stirring tank and stir at 30 °C. Use a high-speed shear mixer with a rotation speed set at 700 rpm and stir continuously for 2 hours to ensure uniform mixing of the two.

[0110] Add isocyanate and asymmetric amino curing agent: Add 9 parts by mass of isocyanate and 16 parts by mass of asymmetric amino curing agent to the mixture of modified epoxy resin and polyurethane, adjust the temperature to 48 °C, and continue stirring for 1.5 hours to ensure sufficient reaction.

[0111] Add metal organic catalyst, toughening agent and nano graphene: After treating 3 parts by mass of nano graphene by ultrasonic dispersion (power 250 W, frequency 22 kHz, time 45 minutes), slowly add it to the above mixture, and also add 4 parts by mass of polyester toughening agent and 1 part by mass of metal organic catalyst to the above mixture, and continue stirring until uniform.

[0112] Add defoaming agent and accelerator: Add 0.7 parts by mass of defoaming agent and 2.5 parts by mass of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0113] Filtration and packaging: Filter through a 350-mesh stainless steel sieve to remove insoluble particles, and finally package.

[0114] Comparative example 1: Compared with Example 1, nano graphene is not added to the formula, and the other components, ratios and preparation processes remain unchanged.

[0115] Comparative example 2: Compared with Example 2, metal organic catalyst is not used in the formula, and the other components, ratios and preparation processes remain unchanged.

[0116] Comparative example 3: Compared with Example 3, polyurethane is not used in the formula, and the other components, ratios and preparation processes remain unchanged.

[0117] Experiment 1: Implementation steps: Sample preparation: Substrate Selection and Treatment: Select 12 standard concrete test blocks (100mm × 100mm × 10mm), 2 blocks per group, for a total of 6 groups.

[0118] Grind the test blocks with 250 - grit diamond sandpaper to remove the floating dust and improve the coating adhesion.

[0119] Use ultrasonic cleaning to remove the fine dust, and then dry at 50°C for 2 hours.

[0120] Coating Preparation and Application: Prepare the coating materials according to the formulas of Example 1 and Comparative Example 1 respectively.

[0121] Adopt the scraping coating process to evenly coat and bond on the bonding surfaces of two test blocks. Control the coating thickness at 1.0mm (±0.1mm). There are three groups in Example 1, numbered 1, 2, and 3, and three groups in Comparative Example 1, numbered 4, 5, and 6.

[0122] Specimen Grouping and Curing: Base Surface Test Group (6 groups): Cure for 7 days in an environment of 23°C ± 2°C.

[0123] 2. Test Methods and Number of Tests Base Surface Tensile Shear Strength Test Experimental Equipment: Universal Material Testing Machine (loading rate 5mm / min) Test Steps: Fix the specimen in the fixture of the universal material testing machine to keep the force evenly distributed.

[0124] Apply shear force at a loading rate of 5mm / min until the coating peels off.

[0125] Record the maximum shear strength (MPa). Each group of specimens is tested 3 times, with a total of 6 groups of data, and take the average value.

[0126] Experimental Data: Table 1: Test Results of Coating Bonding Strength under Different Formulas Specimen Number Group Test 1 (MPa) Test 2 (MPa) Test 3 (MPa) Average Value (MPa) 1 Example 1 3.42 3.38 3.45 3.42 2 Example 1 3.4 3.37 3.41 3.39 3 Example 1 3.44 3.39 3.46 3.43 4 Comparative Example 1 2.9 2.88 2.92 2.9 5 Comparative Example 1 2.85 2.83 2.86 2.85 6 Comparative Example 1 2.89 2.87 2.91 2.89 The average bonding strength of Example 1 (containing nano - graphene) is between 3.39 - 3.43MPa, significantly higher than that of Comparative Example 1 (2.85 - 2.90MPa).

[0127] The test results show that the addition of nano - graphene can effectively improve the adhesion of the coating, making the coating form a stronger bonding force on the substrate surface.

[0128] From the mechanism analysis, the high specific surface area of graphene fills the micropores of the coating, improves the matrix density, and enhances the interfacial bonding force, making the coating not easy to peel off.

[0129] The results of this experiment prove that the nano-graphene reinforced epoxy resin coating has obvious advantages in terms of bonding performance.

[0130] Experiment 2: Implementation steps: Sample preparation: Substrate selection and treatment: Select 12 standard concrete test blocks (100mm×100mm×10mm), 2 blocks per group, a total of 6 groups.

[0131] The test blocks are polished with 250-grit emery paper to remove floating dust and improve the coating adhesion.

[0132] Ultrasonic cleaning is used to remove fine dust, and then dried at 50°C for 2 hours.

[0133] Coating formulation and application: Prepare the coating materials according to the formulations of Example 2 and Comparative Example 2 respectively.

[0134] Adopt the scraping process to evenly coat and bond on the bonding surfaces of two test blocks. The coating thickness is controlled at 1.0mm (±0.1mm). There are three groups in Example 2, numbered 11, 22, 33, and three groups in Comparative Example 2, numbered 44, 55, 66.

[0135] Curing speed test Testing equipment: Use the Vicat softening point tester as the testing equipment.

[0136] Testing steps: Place the specimens after coating the coating in a conventional environment (23°C ± 2°C, humidity about 50%).

[0137] At regular intervals (such as every 15 minutes), use the Vicat softening point tester to measure the hardening state of the coating.

[0138] Record the curing process of each sample and calculate its curing time.

[0139] The test period for Example 2 and Comparative Example 2 is 1.5 hours, and it is measured every 30 minutes. Record the start and end time points of curing.

[0140] Experimental data: Table 2: Curing speed test results of Example 2 and Comparative Example 2 The experimental results show that the curing speed of Example 2 is significantly better than that of Comparative Example 2. The average curing time of Example 2 is between 0.7 and 0.8 hours, while that of Comparative Example 2 is 1.1 to 1.25 hours, with a significant difference. This indicates that the formulation containing the metal-organic catalyst can effectively accelerate the curing process.

[0141] The role of the catalyst in the curing process is very crucial. It accelerates the chemical reaction between the resin and the curing agent, shortening the curing time of the coating. In contrast, the curing process of Comparative Example 2 without a catalyst is slower, and the hardening time of the coating is significantly increased.

[0142] From these experimental data, we can conclude that the addition of the metal-organic catalyst significantly improves the curing rate of the coating, which is of great significance for industrial coating applications that require rapid curing.

[0143] Experiment 3: Implementation steps: Sample preparation: Substrate selection and treatment: Select 12 standard concrete specimens (100mm×100mm×10mm), 2 specimens per group, for a total of 6 groups.

[0144] The specimens are polished with 250-grit emery paper to remove the floating dust and improve the adhesion of the coating.

[0145] Ultrasonic cleaning is used to remove the fine dust, and then dried at 50°C for 2 hours.

[0146] Coating formulation and application: Prepare the coating materials according to the formulations of Example 3 and Comparative Example 3 respectively.

[0147] The scraping coating process is used to evenly coat and bond the adhesive surfaces of two specimens. The coating thickness is controlled at 1.0 mm (±0.1 mm). There are three groups in Example 3, numbered 111, 222, and 333, and three groups in Comparative Example 3, numbered 444, 555, and 666.

[0148] Curing speed test Testing equipment: Use a Vicat softening point tester.

[0149] Testing steps: Place the specimens after coating the coating in a conventional environment (23°C ± 2°C, humidity about 50%).

[0150] At regular intervals (such as every 15 minutes), use a Vicat softening point tester to measure the hardening state of the coating.

[0151] Record the curing process of each sample and calculate its curing time.

[0152] The test period for Example 3 and Comparative Example 3 is 1.5 hours, and measurements are taken every 30 minutes to record the start and end time points of curing.

[0153] Experimental data: Table 3: Curing speed test results of Example 3 and Comparative Example 3 Curing speed comparison: The curing time of Example 3 is significantly faster than that of Comparative Example 3. The curing time is between 0.7 - 0.8 hours, while that of Comparative Example 3 is between 1.1 - 1.2 hours.

[0154] This indicates that polyurethane has a significant promoting effect on the curing of the coating, shortening the curing time.

[0155] The addition of polyurethane can significantly accelerate the curing speed of the coating, which is of great significance for industrial applications that require rapid curing.

[0156] The slower curing of Comparative Example 3 shows that polyurethane plays a key role in the formulation and can improve the curing efficiency.

[0157] This experiment shows that the addition of polyurethane can effectively improve the curing speed of the coating and provide significant advantages in applications where rapid hardening of the coating is required.

[0158] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A highly environmentally friendly and flexible modified epoxy resin waterproof coating, characterized in that: The composition includes the following components in parts by weight: 40-50 parts by mass of modified epoxy resin; Polyurethane 10-15 parts by mass; 8 to 12 parts by mass of isocyanate; 15-20 parts by weight of asymmetric amino curing agent; 2 to 5 parts by mass of nanographene; 3 to 6 parts by weight of polyester toughening agent; 1 to 2 parts by weight of a metal organic catalyst; Defoaming agent 0.5-1 parts by mass; Accelerator 2 to 3 parts by weight.

2. The highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 1, characterized in that: The modified epoxy resin is a copolymer of epoxy resin and amino resin, and the mass ratio of the epoxy resin to the amino resin is 3:1 to 2:

1.

3. The highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 1, characterized in that: The asymmetric amino curing agent is one of polyamide and alicyclic amine curing agents.

4. The highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 1, characterized in that: The metal organic catalyst is one of a cobalt catalyst and a bismuth catalyst.

5. The highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 1, characterized in that: The polyester toughening agent is a copolymer of polybutylene terephthalate and polyether polyol, and the mass ratio of the polybutylene terephthalate to the polyether polyol is 3:1 to 2:

1.

6. The highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 1, characterized in that: The accelerator is a copolymer of an organic phosphorus compound and a quaternary ammonium salt, and the mass ratio of the organic phosphorus compound to the quaternary ammonium salt is 3:1 to 2:

1.

7. A method for preparing a highly environmentally friendly and flexible modified epoxy resin waterproof coating, which is used to prepare the highly environmentally friendly and flexible modified epoxy resin waterproof coating as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1: mixing epoxy resin and amino resin in a mass ratio of 3:1 to 2:1, and continuously stirring at a temperature of 30° C. to 50° C. for 2 to 4 hours to prepare a modified epoxy resin; S2: during the stirring process of preparing the modified epoxy resin, adding isocyanate and an asymmetric amino curing agent, and continuously stirring at a temperature of 45° C. to 60° C. for 1 to 3 hours; S3: polybutylene terephthalate and polyether polyol are mixed in a mass ratio of 3:1 to 2:1, and nanographene and a metal organic catalyst are added, and after stirring at 40° C. to 55° C. for 1 to 2 hours, the mixture is slowly added to the mixture of S2, and stirring is continued until uniform; S4: adding a defoamer and a promoter to the mixture of S3, adjusting the viscosity and fluidity of the mixture, and stirring at a temperature of 25° C. to 35° C. for 30 to 60 minutes to make all the ingredients evenly dispersed; S5: After being evenly mixed, filtering and packaging are performed to complete the preparation of the highly environmentally friendly and flexible modified epoxy resin waterproof coating.

8. The method for preparing the highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 7, characterized in that: The stirring is carried out using a high-speed shearing mixer, the rotation speed of which is controlled at 500-1000 rpm, so as to fully mix the modified epoxy resin and the polyurethane.

9. The method for preparing the highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 7, characterized in that: The nano-graphene is added by using ultrasonic dispersion technology, and is dispersed for 30 to 60 minutes in an ultrasonic environment with a power of 200 to 500 W and a frequency of 20 to 40 kHz.

10. The method for preparing the highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 7, characterized in that: The filtration uses a 300-500 mesh stainless steel screen to remove incompletely dispersed particles or impurities.

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