Highly environmentally friendly and flexible modified epoxy resin waterproof coating and its preparation method

Abstract

This application relates to the field of coating technology, and discloses a highly environmentally friendly and flexible modified epoxy resin waterproof coating and its preparation method. The modified epoxy resin waterproof coating comprises the following components in parts by weight: 40-50 parts by weight of modified epoxy resin; 10-15 parts by weight of polyurethane; 8-12 parts by weight of isocyanate; 15-20 parts by weight of asymmetric amino curing agent; 2-5 parts by weight of nano-graphene; 3-6 parts by weight of polyester toughening agent; 1-2 parts by weight of organometallic catalyst; 0.5-1 part by weight of defoamer; and 2-3 parts by weight of accelerator. This invention combines organometallic catalyst and polyurethane to accelerate the curing speed of the coating. This improvement significantly shortens the curing time of the coating after application, compared to the problem of excessively long curing times in existing technologies. This not only improves construction efficiency but also reduces performance instability caused by incomplete curing, ensuring high-quality and efficient coating completion.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a highly environmentally friendly and flexible modified epoxy resin waterproof coating and its preparation method. Background Technology

[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 properties, chemical stability, and mechanical strength. However, traditional epoxy resin coatings still have many technical limitations in practical applications, affecting their promotion and long-term effectiveness.

[0003] First, cured epoxy resins often exhibit high hardness and brittleness, lacking sufficient flexibility. This makes them prone to cracking under temperature changes or mechanical stress, thus affecting the coating's durability. 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 and mechanical deformation. Especially in applications requiring a certain degree of elasticity to adapt to substrate deformation, traditional epoxy resin coatings cannot effectively buffer external forces, easily leading to cracks and reduced protective effects.

[0004] Secondly, existing epoxy resin coatings have a slow curing speed and long construction cycle, directly affecting 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 these systems ensure curing effects, they often have long curing times. In humid and hot environments, the curing process may be affected by environmental factors, leading to uneven curing of the coating and even the generation of internal stress, further weakening the physical properties of the coating. The long curing process not only prolongs the construction cycle but also increases the requirements for construction environmental conditions, limiting the applicability of the coating.

[0005] Furthermore, traditional epoxy resin coatings suffer from insufficient strength and poor stability in everyday environments, especially under high temperatures or prolonged exposure to ultraviolet radiation and high humidity, where their aging resistance is significantly limited. Existing reinforcing and modification techniques, such as adding inorganic fillers or glass fibers, can improve coating durability to some extent, but often at the cost of flexibility or processability, failing to simultaneously achieve crack resistance, aging resistance, and ease of application.

[0006] Therefore, this invention proposes a highly environmentally friendly and flexible modified epoxy resin waterproof coating and its preparation method to overcome the shortcomings of the prior art. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a highly environmentally friendly and flexible modified epoxy resin waterproof coating and its preparation method, solving the problems of excessively long curing time, insufficient flexibility, and poor aging resistance of traditional epoxy resin waterproof coatings.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a highly environmentally friendly and flexible modified epoxy resin waterproof coating, comprising the following components in parts by weight: 40-50 parts by weight of modified epoxy resin; 10-15 parts by weight of polyurethane; 8-12 parts by weight of isocyanate; 15-20 parts by weight of asymmetric amino curing agent; 2-5 parts by weight of nano-graphene; 3-6 parts by weight of polyester toughening agent; 1-2 parts by weight of organometallic catalyst; 0.5-1 part by weight of defoamer; and 2-3 parts by weight of accelerator.

[0009] Modified epoxy resin

[0010] Modified epoxy resin is mainly obtained through the copolymerization reaction of epoxy resin and amino resin. It has 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. Epoxy resin is reactive; it contains active epoxy groups that can undergo cross-linking reactions with the curing agent to form a cross-linked structure, enhancing the weather resistance and water resistance of the coating.

[0011] Copolymerization with amino resins improves the flexibility of the epoxy resin, enhancing the coating's ductility and crack resistance. The addition of amino resins effectively increases the elasticity of the epoxy resin, thereby improving the coating's impact resistance and anti-peeling properties.

[0012] polyurethane

[0013] Polyurethane is an important reinforcing material. Through copolymerization with epoxy resin, polyurethane can enhance the flexibility and aging resistance of coatings.

[0014] Enhanced flexibility: Polyurethane itself has high flexibility and wear resistance. When copolymerized with epoxy resin, it can significantly improve the mechanical strength of the coating and enhance its impact resistance and wear resistance.

[0015] It is resistant to aging. 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.

[0016] Isocyanates

[0017] Isocyanates are used to react with epoxy resins and other curing agents to form cross-linked structures. Their function is to accelerate the curing reaction and improve the chemical resistance of the coating.

[0018] Reactivity: Isocyanates have active isocyanate (-NCO) groups, which can react with substances containing amino, hydroxyl or other reactive groups to form a strong cross-linked structure in epoxy resin systems.

[0019] Curing is accelerated; the addition of isocyanate can significantly speed up the curing process of coatings, especially in humid or low-temperature environments, and can also effectively promote the curing of coatings, reducing the waiting time after application.

[0020] Asymmetric amino curing agent

[0021] Asymmetric amino curing agents refer to polyamide or alicyclic amine curing agents, which are commonly used in reactions with epoxy resins. Their addition can improve the high-temperature resistance, corrosion resistance, and faster curing reaction of coatings.

[0022] When reacting with epoxy resin, the amino groups in the asymmetric amino curing agent undergo an addition reaction with the epoxy groups in the epoxy resin to form a stable cross-linked network, thereby improving the water resistance and mechanical strength of the coating.

[0023] Curing time adjustment: Compared with traditional amine curing agents, asymmetric amino curing agents are more reactive, which can shorten the curing time, increase the crosslinking density of the final coating, and enhance its physical properties.

[0024] Nanographene

[0025] Nano-graphene, as a reinforcing material, can significantly improve the crack resistance, aging resistance, and thermal stability of coatings. Its addition can increase the mechanical properties of coatings and improve their durability.

[0026] As a reinforcing material, nano-graphene has an extremely high specific surface area and excellent mechanical properties. Its addition can significantly enhance the structural strength of coatings and improve their crack resistance and impact resistance.

[0027] Improved thermal conductivity: Nano-graphene 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.

[0028] To improve aging resistance, nano-graphene can effectively inhibit the damage of ultraviolet rays to the coating and enhance the coating's resistance to ultraviolet aging.

[0029] Polyester toughening agent

[0030] Polyester toughening agents mainly refer to copolymers of polybutylene terephthalate and polyether polyols. Their function is to enhance the flexibility and impact resistance of the coating, and improve its crack resistance.

[0031] Improved flexibility: The addition of polyester toughening agent makes epoxy resin coatings more flexible after curing, reducing the probability of cracks in the coating due to external forces.

[0032] Enhanced impact resistance: Polyester toughening agents can improve the impact resistance of the coating and enhance its ability to withstand mechanical impacts during construction.

[0033] Organometallic catalysts

[0034] Organometallic catalysts (such as cobalt catalysts and bismuth catalysts) are used to accelerate the curing reaction of epoxy resins, thereby improving the curing rate and application efficiency of coatings.

[0035] Catalysis: Organometallic catalysts can significantly increase the reaction rate between epoxy resin and curing agent, especially at lower temperatures, promoting rapid cross-linking reactions and reducing the drying and curing time of coatings.

[0036] By increasing the crosslinking density, the catalyst can promote the reaction of more epoxy groups with the curing agent, thereby increasing the crosslinking density and enhancing the physical properties of the coating.

[0037] Defoamer

[0038] Defoamers are used to remove air bubbles in coating systems to prevent the formation of pores or foam during the coating curing process, which can affect the smoothness and density of the coating.

[0039] Defoamers effectively reduce the surface tension of coating systems, inhibiting the formation and expansion of bubbles, thus ensuring a smooth and even coating surface.

[0040] Improving coating density and removing air bubbles helps to increase the density of the coating, avoid weak points caused by air bubbles in the coating, and enhance waterproof performance and durability.

[0041] Accelerator

[0042] Accelerators (such as copolymers of organophosphorus compounds and quaternary ammonium salts) are used to speed up the curing reaction and adjust the viscosity and flowability of the coating.

[0043] Accelerators can speed up the chemical reaction between epoxy resin and curing agent, allowing the coating to cure in a shorter time.

[0044] Improving fluidity: By adjusting the viscosity of the coating, accelerators help improve the workability of the coating, especially when applying it over a large area, ensuring uniform coating and avoiding uneven coating.

[0045] 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.

[0046] Epoxy resins provide coatings with corrosion resistance, strength, and adhesion, while polyurethane imparts flexibility, impact resistance, and crack resistance. Through copolymerization, the properties of the two complement each other, enhancing the overall performance of the coating.

[0047] The epoxy groups in epoxy resin react with the amino or hydroxyl groups in polyurethane to form a cross-linked network structure, enhancing the coating's strength and corrosion resistance. The flexible molecular chain structure of polyurethane enhances the coating's ductility and crack resistance, preventing cracking under external force or temperature changes. At a mass ratio of 3:1, the coating exhibits higher hardness and stronger corrosion resistance; at 2:1, it offers better flexibility and crack resistance.

[0048] Preferably, the asymmetric amino curing agent is one of polyamide or alicyclic amine curing agents.

[0049] Asymmetric amino curing agents, such as polyamides or alicyclic amines, are used to react with epoxy resins and accelerate their curing process. Polyamide curing agents consist of amine and amide groups, while alicyclic amine curing agents contain cyclic amine structures. Both can improve the coating's chemical resistance, high-temperature resistance, and water resistance.

[0050] Polyamide curing agents form a robust cross-linked structure through the addition reaction of amino and epoxy groups, which enhances the mechanical strength and corrosion resistance of the coating.

[0051] Alicyclic amine curing agents have a highly reactive cyclic amine structure, which accelerates curing and improves the coating's anti-aging and UV resistance.

[0052] The high reactivity of asymmetric amino curing agents accelerates the curing process, shortens application time, and improves the overall performance of the coating.

[0053] Preferably, the organometallic catalyst is one of a cobalt catalyst or a bismuth catalyst.

[0054] Organometallic catalysts, such as cobalt 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 resin and curing agent, thereby speeding up the curing process and reducing the waiting time after application.

[0055] Cobalt catalysts can accelerate the curing process by catalyzing the reaction between epoxy resin and curing agent, lowering the activation energy of the reaction, and promoting the ring-opening reaction of epoxy groups. Cobalt catalysts can also promote curing at lower temperatures, improving construction efficiency.

[0056] Bismuth catalysts accelerate the reaction between epoxy resin and hardener by providing electron support during the curing reaction, especially in high humidity or low temperature environments, maintaining the stability of the curing rate and enhancing the weather resistance and mechanical properties of the coating.

[0057] Preferably, the polyester toughening agent is a copolymer of polybutylene terephthalate and polyether polyol, wherein the mass ratio of polybutylene terephthalate to polyether polyol is 3:1 to 2:1.

[0058] This polyester toughening agent is formed by copolymerizing PBT and polyether polyol, while controlling the mass ratio of the two to be between 3:1 and 2:1, so as to improve the toughness and impact resistance of the coating while maintaining good mechanical strength and weather resistance.

[0059] The PBT structure provides high strength. PBT has good crystallinity, which gives the coating high rigidity, heat resistance and chemical resistance, while enhancing the mechanical strength and wear resistance of the material.

[0060] Polyether polyols provide flexibility. The high flexibility of polyether polyol molecular chains can improve the ductility of coatings, increase impact absorption capacity, reduce brittleness, and improve crack resistance.

[0061] The copolymer balances rigidity and flexibility, ensuring a balance between rigidity and toughness within a mass ratio range of 3:1 to 2:1. This results in a coating that possesses excellent mechanical strength while resisting external impacts and temperature changes, thereby improving durability and workability.

[0062] Preferably, the accelerator is a copolymer of an organophosphorus compound and a quaternary ammonium salt, wherein the mass ratio of the organophosphorus compound to the quaternary ammonium salt is 3:1 to 2:1.

[0063] This accelerator is prepared by copolymerizing an organophosphorus compound with a quaternary ammonium salt at a mass ratio controlled between 3:1 and 2:1. It is used to improve the curing rate of epoxy resin and enhance the stability of the cured network.

[0064] Organophosphorus compounds have excellent catalytic properties, which can lower the activation energy of the curing reaction, accelerate the ring-opening reaction of epoxy groups, and improve heat resistance and chemical corrosion resistance.

[0065] Quaternary ammonium salts, as phase transfer catalysts, improve the compatibility between epoxy resin and curing agent, enhance ion conductivity, accelerate crosslinking reaction, and improve curing uniformity and final mechanical properties.

[0066] The copolymerization process, with a mass ratio of 3:1 to 2:1, can achieve balanced performance of the accelerator, which can improve curing efficiency and optimize the mechanical strength and durability after curing, avoiding uneven curing or brittleness caused by excessive catalysis.

[0067] This invention also provides a method for preparing a highly environmentally friendly and flexible modified epoxy resin waterproof coating, comprising the following steps:

[0068] S1: Mix epoxy resin and amino resin in a mass ratio of 3:1 to 2:1 and stir continuously at 30℃ to 50℃ for 2 to 4 hours to prepare modified epoxy resin.

[0069] Epoxy resin and amino resin are mixed at a mass ratio of 3:1 to 2:1 and stirred continuously at 30℃ to 50℃ for 2 to 4 hours. This process ensures that the epoxy resin and amino resin are fully mixed, so that their chemical structures are evenly distributed, forming a preliminary copolymer system, improving the flexibility and durability of the coating, while avoiding local phase separation that could lead to uneven performance.

[0070] S2: During the stirring process of preparing modified epoxy resin, add isocyanate and asymmetric amino curing agent, and continue stirring at a temperature of 45℃~60℃ for 1~3 hours.

[0071] During the S1 stirring process, isocyanate and asymmetric amino curing agent are gradually added, and the temperature is raised to 45℃~60℃, with continuous stirring for 1~3 hours. Isocyanate can further react with polyurethane to increase the degree of crosslinking of the system, enhancing chemical resistance and water resistance; the asymmetric amino curing agent accelerates the curing of epoxy groups, improving the curing rate and coating strength, ensuring the durability of the final product.

[0072] S3: Mix polybutylene terephthalate and polyether polyol in a mass ratio of 3:1 to 2:1, add nano-graphene and organometallic catalyst, and stir at 40℃ to 55℃ for 1 to 2 hours. Then slowly add the mixture to S2 and continue stirring until homogeneous.

[0073] Polybutylene terephthalate (PBT) and polyether polyol are mixed at a mass ratio of 3:1 to 2:1 and stirred at 40℃ to 55℃ for 1 to 2 hours to ensure full integration and improve toughening effect. Subsequently, nano-graphene is added to enhance conductivity, wear resistance, and corrosion resistance. Simultaneously, an organometallic catalyst (such as cobalt or bismuth catalyst) is added to promote the epoxy resin curing reaction and improve application adaptability. After thorough mixing, this mixture is slowly added to the S2 mixture, and stirring continues until the system is homogeneous and stable.

[0074] S4: Add defoamer and accelerator to the mixture in S3, adjust the viscosity and flowability of the mixture, and stir at 25℃~35℃ for 30~60 minutes to ensure that all components are evenly dispersed.

[0075] Defoamers and accelerators are added to the S3 mixture to improve the coating's application properties. The defoamer effectively eliminates air bubbles, prevents defects during curing, and improves the film's density. The accelerator (a copolymer of organophosphorus compounds and quaternary ammonium salts at a mass ratio of 3:1 to 2:1) further optimizes the curing rate, making the curing process more stable and uniform. Stirring at 25°C to 35°C for 30 to 60 minutes ensures uniform dispersion of all components, ultimately forming a homogeneous and stable coating system.

[0076] S5: After uniform mixing, the mixture is filtered and packaged to complete the preparation of a highly environmentally friendly and flexible modified epoxy resin waterproof coating.

[0077] After uniform mixing, the coating is filtered to remove any potential agglomerated particles, improving product uniformity and coating smoothness. Finally, it is packaged and stored, completing the preparation of a highly environmentally friendly, flexible modified epoxy resin waterproof coating. This coating possesses excellent flexibility, waterproofing, chemical resistance, and application adaptability, making it suitable for various building waterproofing projects.

[0078] Preferably, the mixing is performed using a high-speed shear mixer with a rotation speed controlled at 500-1000 rpm, for fully mixing the modified epoxy resin and polyurethane.

[0079] During the mixing process of modified epoxy resin and polyurethane, a high-speed shear mixer is used, and the speed is controlled at 500-1000 rpm to ensure that the two are fully mixed to form a uniform copolymer system, avoid phase separation or uneven component distribution, thereby improving the stability and performance of the final coating.

[0080] High-speed shearing and stirring can break down droplets and polymer aggregates, allowing epoxy resin and polyurethane to be fully dispersed at the microscale, forming a stable emulsion or uniformly dissolved state, thus improving compatibility.

[0081] Rotation speed control, within a range of 500–1000 rpm, ensures that too many bubbles are not generated, affecting product quality, while also providing sufficient shear force to allow the copolymer to form a uniform molecular structure, guaranteeing the mechanical properties and durability of the coating.

[0082] To enhance system stability, efficient stirring can promote the interaction between epoxy groups and polyurethane, improve the density of the cured coating, and enhance water resistance, chemical resistance, and weather resistance.

[0083] Preferably, the addition of the nano-graphene is performed using ultrasonic dispersion technology, which disperses the nano-graphene for 30 to 60 minutes in an ultrasonic environment with a power of 200 to 500W and a frequency of 20 to 40kHz.

[0084] During the preparation process, the nano-graphene is pretreated by ultrasonic dispersion technology. It is dispersed in an ultrasonic environment with a power of 200-500W and a frequency of 20-40kHz for 30-60 minutes to ensure that the nano-graphene is uniformly distributed in the coating system and to improve its reinforcing performance.

[0085] Ultrasonic cavitation effect: When ultrasound propagates in a liquid, it generates local high temperature and high pressure cavitation, which can break up the aggregation of nano-graphene, making it uniformly dispersed in the matrix, avoiding sedimentation and aggregation, and improving stability.

[0086] Power and frequency control, with 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 the nanographene is not damaged, while promoting bonding with the resin matrix and improving conductivity and wear resistance.

[0087] By uniformly dispersing nano-graphene, the coating performance can be enhanced, thereby improving the corrosion resistance, mechanical strength, thermal conductivity and crack resistance of the coating, thus improving the overall performance of the waterproof coating.

[0088] Preferably, the filter uses a 300-500 mesh stainless steel screen to remove incompletely dispersed particles or impurities.

[0089] 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, ensuring the uniformity of the coating and improving the quality of application.

[0090] Fine particle removal: The 300-500 mesh screen has an aperture of approximately 25-50 micrometers, which can effectively filter out incompletely dispersed fillers, polymer agglomerates, or impurities, preventing uneven particles from affecting the smoothness and adhesion of the coating.

[0091] Improving coating quality: After filtration, a uniform and fine coating can be obtained, improving workability and avoiding surface defects such as pinholes and particle deposition caused by particles clogging the spraying equipment.

[0092] Ensuring stability and removing impurities can improve the long-term stability of the coating, prevent sedimentation, and enhance the wear resistance, water resistance, and weather resistance of the final coating.

[0093] This invention provides a highly environmentally friendly and flexible modified epoxy resin waterproof coating and its preparation method. It has the following beneficial effects:

[0094] 1. This invention combines a metal-organic catalyst with polyurethane to accelerate the curing speed of the coating. This improvement significantly shortens the curing time of the coating after application, addressing the problem of excessively long curing times in existing technologies. This not only improves application efficiency but also reduces performance instability caused by incomplete curing, ensuring high-quality and efficient coating completion.

[0095] 2. This invention successfully improves the crack resistance and high-temperature resistance of coatings by introducing nano-graphene reinforcing materials. Existing coatings often lack sufficient strength in everyday environments, while the coating of this invention exhibits better crack resistance and high-temperature resistance under these conditions, significantly enhancing its adaptability to complex environments.

[0096] 3. This invention employs a modified epoxy resin and polyurethane composite technology, achieving the technical effect of improving the flexibility and aging resistance of the coating. Compared with traditional epoxy resin coatings in the prior art, the modified coating greatly improves its brittleness problem, maintaining high stability and protective effect even after long-term use, and avoiding coating cracking and loss of function. Attached Figure Description

[0097] Figure 1 This is a flowchart of the preparation method of the present invention. Detailed Implementation

[0098] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0099] Please see Figure 1 ,

[0100] Example 1:

[0101] Composition ratio (parts by weight): Modified epoxy resin: 40; Polyurethane: 10; Isocyanate: 15; Asymmetric amino curing agent: 18; Nano-graphene: 2; Polyester toughening agent: 3; Organometallic catalyst: 1; Defoamer: 0.5; Accelerator: 2.

[0102] Specific preparation steps:

[0103] Preparation of modified epoxy resin: 30 parts by weight of epoxy resin and 10 parts by weight of amino resin were placed in a mixing tank and stirred at 30°C. A high-speed shear mixer was used at 500 rpm for 2 hours to ensure uniform mixing.

[0104] Add isocyanate and asymmetric amino curing agent: Add 10 parts by weight of isocyanate and 15 parts by weight 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 a complete reaction.

[0105] Addition of 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.

[0106] Add defoamer and accelerator: Add 0.5 parts by weight of defoamer and 2 parts by weight of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0107] Filtration and Packaging: Insoluble particles are removed by filtration through a 300-mesh stainless steel screen before final packaging.

[0108] Example 2:

[0109] Composition ratio (parts by weight): Modified epoxy resin: 50; Polyurethane: 15; Isocyanate: 12; Asymmetric amino curing agent: 20; Nano-graphene: 5; Polyester toughening agent: 6; Organometallic catalyst: 2; Defoamer: 1; Accelerator: 3.

[0110] Specific preparation steps:

[0111] Preparation of modified epoxy resin: 33 parts by weight of epoxy resin and 16 parts by weight of amino resin were placed in a mixing tank and stirred at 45°C. A high-speed shear mixer was used at 900 rpm for 2.5 hours to ensure uniform mixing.

[0112] Add isocyanate and asymmetric amino curing agent: Add 12 parts by weight of isocyanate and 20 parts by weight 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 a complete reaction.

[0113] Addition of 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.

[0114] Add defoamer and accelerator: Add 1 part by weight of defoamer and 3 parts by weight of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0115] Filtration and Packaging: Insoluble particles are removed by filtration through a 400-mesh stainless steel screen before final packaging.

[0116] Example 3:

[0117] Component ratio (parts by weight): Modified epoxy resin: 45; Polyurethane: 12; Isocyanate: 10; Asymmetric amino curing agent: 17; Nano-graphene: 3; Polyester toughening agent: 4; Organometallic catalyst: 1.5; Defoamer: 0.8; Accelerator: 2.5.

[0118] Specific preparation steps:

[0119] Preparation of modified epoxy resin: 30 parts by weight of epoxy resin and 15 parts by weight of amino resin were placed in a mixing tank and stirred at 35°C. A high-speed shear mixer was used, with the speed set to 600 rpm, and stirred for 2 hours to ensure uniform mixing.

[0120] Add isocyanate and asymmetric amino curing agent: Add 10 parts by weight of isocyanate and 17 parts by weight 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 a complete reaction.

[0121] Addition of metal-organic catalyst, toughening agent and nano-graphene: After treating 3 parts by mass of nano-graphene by ultrasonic dispersion (power 300W, frequency 25kHz, 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 uniform.

[0122] Add defoamer and accelerator: Add 0.8 parts by weight of defoamer and 2.5 parts by weight of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0123] Filtration and Packaging: Insoluble particles are removed by filtration through a 300-mesh stainless steel screen before final packaging.

[0124] Example 4:

[0125] Component ratio (parts by weight): Modified epoxy resin: 48; Polyurethane: 14; Isocyanate: 11; Asymmetric amino curing agent: 19; Nano-graphene: 4; Polyester toughening agent: 5; Organometallic catalyst: 1.2; Defoamer: 0.6; Accelerator: 2.2.

[0126] Specific preparation steps:

[0127] Preparation of modified epoxy resin: 35 parts by weight of epoxy resin and 13 parts by weight of amino resin were placed in a mixing tank and stirred at 40°C. A high-speed shear mixer was used with a speed set to 550 rpm for 2 hours to ensure uniform mixing.

[0128] Add isocyanate and asymmetric amino curing agent: Add 11 parts by weight of isocyanate and 19 parts by weight 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 a complete reaction.

[0129] Addition of metal-organic catalyst, toughening agent and nano-graphene: After treating 4 parts by mass of nano-graphene by ultrasonic dispersion (power 350W, frequency 30kHz, 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 uniform.

[0130] Add defoamer and accelerator: Add 0.6 parts by weight of defoamer and 2.2 parts by weight of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0131] Filtration and Packaging: Insoluble particles are removed by filtration through a 350-mesh stainless steel screen before final packaging.

[0132] Example 5:

[0133] Component ratio (parts by weight): Modified epoxy resin: 43; Polyurethane: 13; Isocyanate: 9; Asymmetric amino curing agent: 16; Nano-graphene: 3; Polyester toughening agent: 4; Organometallic catalyst: 1; Defoamer: 0.7; Accelerator: 2.5.

[0134] Specific preparation steps:

[0135] Preparation of modified epoxy resin: 30 parts by weight of epoxy resin and 13 parts by weight of amino resin were placed in a mixing tank and stirred at 30°C. A high-speed shear mixer was used with a speed set to 700 rpm for 2 hours to ensure uniform mixing.

[0136] Add isocyanate and asymmetric amino curing agent: Add 9 parts by weight of isocyanate and 16 parts by weight 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 a complete reaction.

[0137] Addition of metal-organic catalyst, toughening agent and nano-graphene: After treating 3 parts by mass of nano-graphene by ultrasonic dispersion (power 250W, frequency 22kHz, 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.

[0138] Add defoamer and accelerator: Add 0.7 parts by weight of defoamer and 2.5 parts by weight of accelerator to the above mixture and stir for 30 minutes to ensure uniform dispersion.

[0139] Filtration and Packaging: Insoluble particles are removed by filtration through a 350-mesh stainless steel screen before final packaging.

[0140] Comparative Example 1:

[0141] Compared with Example 1, no nano-graphene was added to the formulation, while the remaining components, proportions, and preparation process remained unchanged.

[0142] Comparative Example 2:

[0143] Compared to Example 2, no organometallic catalyst was used in the formulation, while the remaining components, proportions, and preparation process remained unchanged.

[0144] Comparative Example 3:

[0145] Compared to Example 3, polyurethane is not used in the formulation, while the remaining components, proportions, and preparation process remain unchanged.

[0146] Experiment 1:

[0147] Implementation steps:

[0148] Sample preparation:

[0149] Substrate selection and treatment:

[0150] Twelve standard concrete test blocks (100mm×100mm×10mm) were selected, with two blocks in each group, for a total of six groups.

[0151] The test block was polished with 250 grit diamond sandpaper to remove loose dust and improve coating adhesion.

[0152] Ultrasonic cleaning was used to remove micro-dust, followed by drying at 50°C for 2 hours.

[0153] Coating preparation and application:

[0154] Coating materials were prepared according to the formulations of Example 1 and Comparative Example 1, respectively.

[0155] The coating was uniformly applied to the bonding surfaces of the two test blocks using a scraping process, and then bonded together. The coating thickness was controlled at 1.0 mm (±0.1 mm). Example 1 had three groups, numbered 1, 2, and 3, and Comparative Example 1 had three groups, numbered 4, 5, and 6.

[0156] Sample grouping and curing:

[0157] Base surface test group (6 groups): cured for 7 days at 23℃±2℃.

[0158] 2. Test methods and number of tests

[0159] Base surface tensile shear strength test

[0160] Experimental equipment: Universal testing machine (loading rate 5 mm / min)

[0161] Test procedure: The sample is fixed in the fixture of the universal testing machine to ensure uniform force.

[0162] Apply shear force at a loading rate of 5 mm / min until the coating peels off.

[0163] Record the maximum shear strength (MPa). Test each sample 3 times, for a total of 6 sets of data, and take the average value.

[0164] Experimental data:

[0165] Table 1: Test results of coating adhesion strength under different formulations

[0166] Sample 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

[0167] The average bond strength of Example 1 (containing nano-graphene) was between 3.39 and 3.43 MPa, which was significantly higher than that of Comparative Example 1 (2.85 to 2.90 MPa).

[0168] The experimental results show that the addition of nano-graphene can effectively improve the adhesion of the coating and make the coating form a stronger bond on the substrate surface.

[0169] Mechanistic analysis shows that graphene's high specific surface area fills the micropores in the coating, increases the density of the substrate, and enhances the interfacial bonding force, making the coating less prone to peeling.

[0170] The experimental results demonstrate that nano-graphene-reinforced epoxy resin coatings have significant advantages in terms of adhesion performance.

[0171] Experiment 2:

[0172] Implementation steps:

[0173] Sample preparation:

[0174] Substrate selection and treatment:

[0175] Twelve standard concrete test blocks (100mm×100mm×10mm) were selected, with two blocks in each group, for a total of six groups.

[0176] The test block was polished with 250 grit diamond sandpaper to remove loose dust and improve coating adhesion.

[0177] Ultrasonic cleaning was used to remove micro-dust, and the product was dried at 50°C for 2 hours.

[0178] Coating preparation and application:

[0179] Coating materials were prepared according to the formulations of Example 2 and Comparative Example 2, respectively.

[0180] The coating was uniformly applied to the bonding surfaces of the two test blocks using a scraping process, and then bonded together. The coating thickness was controlled at 1.0 mm (±0.1 mm). Example 2 had three groups, numbered 11, 22, and 33, and Comparative Example 2 had three groups, numbered 44, 55, and 66.

[0181] Curing speed test

[0182] Testing equipment: Vicat softening point tester was used.

[0183] Test steps:

[0184] The coated sample was placed in a normal environment (23℃±2℃, humidity approximately 50%).

[0185] The hardening state of the coating is measured at regular intervals (e.g., every 15 minutes) using a Vicat softening point tester.

[0186] Record the curing process of each sample and calculate its curing time.

[0187] The test cycle for Example 2 and Comparative Example 2 was 1.5 hours, with measurements taken every 30 minutes, and the start and end times of curing were recorded.

[0188] Experimental data:

[0189] Table 2: Curing speed test results of Example 2 and Comparative Example 2

[0190]

[0191] 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 between 1.1 and 1.25 hours, showing a significant difference. This indicates that the formulation containing a metal-organic catalyst can effectively accelerate the curing process.

[0192] The catalyst plays a crucial role in the curing process, accelerating the chemical reaction between the resin and the curing agent and shortening the curing time of the coating. In contrast, Comparative Example 2, lacking a catalyst, experienced a slower curing process, with a significantly increased coating hardening time.

[0193] Based on these experimental data, we can conclude that the addition of organometallic catalysts significantly improves the curing rate of coatings, which is of great significance for industrial coating applications that require rapid curing.

[0194] Experiment 3:

[0195] Implementation steps:

[0196] Sample preparation:

[0197] Substrate selection and treatment:

[0198] Twelve standard concrete test blocks (100mm×100mm×10mm) were selected, with two blocks in each group, for a total of six groups.

[0199] The test block was polished with 250 grit diamond sandpaper to remove loose dust and improve coating adhesion.

[0200] Ultrasonic cleaning was used to remove micro-dust, and the product was dried at 50°C for 2 hours.

[0201] Coating preparation and application:

[0202] Coating materials were prepared according to the formulations of Example 3 and Comparative Example 3, respectively.

[0203] The coating was uniformly applied to the bonding surfaces of the two test blocks using a scraping process, and then bonded together. The coating thickness was controlled at 1.0 mm (±0.1 mm). There were three groups in Example 3, numbered 111, 222, and 333, and three groups in Comparative Example 3, numbered 444, 555, and 666.

[0204] Curing speed test

[0205] Testing equipment: Vicat softening point tester was used.

[0206] Test steps:

[0207] The coated sample was placed in a normal environment (23℃±2℃, humidity approximately 50%).

[0208] The hardening state of the coating is measured at regular intervals (e.g., every 15 minutes) using a Vicat softening point tester.

[0209] Record the curing process of each sample and calculate its curing time.

[0210] The test cycle for Example 3 and Comparative Example 3 was 1.5 hours, with measurements taken every 30 minutes, and the start and end times of curing were recorded.

[0211] Experimental data:

[0212] Table 3: Curing speed test results of Example 3 and Comparative Example 3

[0213]

[0214]

[0215] Curing speed comparison: The curing time of Example 3 was significantly faster than that of Comparative Example 3, with a curing time between 0.7 and 0.8 hours, while that of Comparative Example 3 was between 1.1 and 1.2 hours.

[0216] This indicates that polyurethane significantly promotes the curing of the coating and shortens the curing time.

[0217] 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.

[0218] The slower curing of Comparative Example 3 indicates that polyurethane plays a key role in the formulation, improving curing efficiency.

[0219] This experiment demonstrates that the addition of polyurethane can effectively improve the curing speed of the coating and provides significant advantages in applications requiring rapid coating hardening.

[0220] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which 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 components include the following parts by mass: 40-50 parts by weight of modified epoxy resin, wherein the modified epoxy resin is a copolymer of epoxy resin and amino resin, and the mass ratio of epoxy resin to amino resin is 3:1 to 2:

1. 10-15 parts by weight of polyurethane; 8-12 parts by weight of isocyanate; 15-20 parts by weight of asymmetric amino curing agent; 2-5 parts by weight of nano-graphene; 3-6 parts by weight of polyester toughening agent, wherein 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. 1-2 parts by weight of organometallic catalyst; Defoamer 0.5-1 parts by weight; The accelerator comprises 2-3 parts by weight, wherein the accelerator 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.

2. 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 the polyamide or alicyclic amine curing agents.

3. The highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 1, characterized in that, The organometallic catalyst is either a cobalt catalyst or a bismuth catalyst.

4. A method for preparing a highly environmentally friendly and flexible modified epoxy resin waterproof coating, used to prepare the highly environmentally friendly and flexible modified epoxy resin waterproof coating as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1: Mix epoxy resin and amino resin in a mass ratio of 3:1 to 2:1 and stir continuously at 30℃ to 50℃ for 2 to 4 hours to prepare modified epoxy resin. S2: During the stirring process of preparing modified epoxy resin, add isocyanate and asymmetric amino curing agent, and continue stirring at a temperature of 45℃~60℃ for 1~3 hours. S3: Mix polybutylene terephthalate and polyether polyol in a mass ratio of 3:1 to 2:1, add nano-graphene and organometallic catalyst, and stir at 40℃ to 55℃ for 1 to 2 hours. Then slowly add the mixture to S2 and continue stirring until homogeneous. S4: Add defoamer and accelerator to the mixture in S3, adjust the viscosity and flowability of the mixture, and stir at 25℃~35℃ for 30~60 minutes to ensure that all components are evenly dispersed. S5: After uniform mixing, the mixture is filtered and packaged to complete the preparation of a highly environmentally friendly and flexible modified epoxy resin waterproof coating.

5. The method for preparing the highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 4, characterized in that, The mixing process employs a high-speed shear mixer with a rotation speed controlled between 500 and 1000 rpm, used to thoroughly mix the modified epoxy resin and polyurethane.

6. The method for preparing the highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 4, characterized in that, The addition of the nano-graphene was achieved using ultrasonic dispersion technology, which dispersed the nano-graphene 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.

7. The method for preparing the highly environmentally friendly and flexible modified epoxy resin waterproof coating according to claim 4, characterized in that, The filter uses a 300-500 mesh stainless steel screen to remove incompletely dispersed particles or impurities.

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