Modified protective material for marine concrete and preparation method and application thereof

Abstract

The application discloses a modified protective material for marine concrete and a preparation method and application thereof, wherein the A component of the material is composed of a modified epoxy resin matrix, a toughening compatilizer and an auxiliary agent, the B component is composed of a functional compound curing agent, a silane modified composite corrosion resistant filler and a curing accelerator, the modified epoxy resin matrix is a bisphenol A epoxy resin modified by an amino-terminated polyether, the functional compound curing agent is a compound of an amine curing agent and an organic silicon modified imidazole, and the silane modified composite corrosion resistant filler is a mixture of silane modified nano silicon dioxide, graphene and mica powder. Under the joint action of the raw material components, the modified protective material has the characteristics of high adhesion, high toughness and long-term corrosion resistance, and can be widely used in the protection of marine concrete as a novel corrosion resistant protective material with excellent performance, can ensure the stability of coating construction quality and protection effect, has high use value and good application prospect.

Description

Technical Field

[0001] This invention relates to a modified protective material for marine concrete, its preparation method, and its application. Background Technology

[0002] Marine concrete structures are exposed to harsh environments such as high salt spray, seawater immersion, alternating wet and dry conditions, and chloride ion corrosion, requiring corrosion protection. Currently, conventional protective materials, such as ordinary epoxy resin coatings and polyurethane coatings, generally suffer from defects such as weak adhesion to concrete substrates, poor resistance to chloride ion penetration, high brittleness after curing, and insufficient weather resistance.

[0003] To improve performance, existing technologies often employ modifications such as adding silane coupling agents or single nanofillers. However, the following drawbacks remain: ① Nanofillers are prone to agglomeration and have poor dispersibility, making it impossible to form a continuous physical barrier layer; ② The reactivity of modified epoxy resin and curing agent is mismatched, resulting in incomplete curing at low temperatures and easy aging of the crosslinked network at high temperatures; ③ The coating has weak alkali resistance and is prone to blistering and peeling in the alkaline environment of concrete, making it difficult to meet the long-term protection requirements of more than 20 years.

[0004] For the reasons stated above, this invention is proposed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a modified protective material for marine concrete with high adhesion, high toughness and long-term corrosion resistance, as well as its preparation method and application.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A modified protective material for marine concrete includes component A and component B; component A is composed of a modified epoxy resin matrix, a toughening compatibilizer, and additives; component B is composed of a functional compound curing agent, a silane-modified composite anti-corrosion filler, and a curing accelerator; the modified epoxy resin matrix is ​​bisphenol A epoxy resin modified with amino-terminated polyether; the functional compound curing agent is a compound of an amine curing agent and an organosilicon-modified imidazole; the silane-modified composite anti-corrosion filler is a silane-modified composite filler; the composite filler is a mixture of nano-silica, graphene, and mica powder.

[0007] The modified protective material described above is further improved by the following steps in the preparation method of the modified epoxy resin matrix: heating bisphenol A epoxy resin to 60℃~70℃, adding terminal amino polyether in proportion, stirring at a constant temperature for 2 h~3 h, and cooling to room temperature to obtain the modified epoxy resin matrix.

[0008] In a further improvement of the aforementioned modified protective material, the mass ratio of the bisphenol A epoxy resin to the amino-terminated polyether is 25:3-4.

[0009] In a further improvement of the aforementioned modified protective material, the toughening compatibilizer is a polyurethane prepolymer.

[0010] In a further improvement of the aforementioned modified protective material, the additive is a mixture of defoamer, leveling agent, and ultraviolet absorber.

[0011] In a further improvement of the modified protective material described above, the mass ratio of the defoamer, leveling agent, and ultraviolet absorber is 5:9:6.

[0012] In a further improvement of the aforementioned modified protective material, the functional compound curing agent is obtained by mixing an amine curing agent with an organosilicon-modified imidazole.

[0013] In a further improvement of the above-mentioned modified protective material, the mass ratio of the amine curing agent to the organosilicon-modified imidazole is 4:1 to 3.

[0014] The modified protective material described above is further improved by the following steps in the preparation method of the silane-modified composite anti-corrosion filler: mixing nano-silica, graphene, and mica powder, adding a silane coupling agent, stirring, and drying to obtain the silane-modified composite anti-corrosion filler.

[0015] In a further improvement of the aforementioned modified protective material, the curing accelerator is benzyl dimethylamine.

[0016] In a further improvement of the above-mentioned modified protective material, the mass ratio of the bisphenol A epoxy resin to the amino-terminated polyether is 100:13-14; and the amino-terminated polyether is polyetheramine T-403.

[0017] In a further improvement of the above-mentioned modified protective material, the defoamer is BYC-7204; the defoamer is BYC-7204; and the ultraviolet absorber is UV-1.

[0018] In a further improvement of the aforementioned modified protective material, the amine curing agent is at least one of 1,3-BAC, IPDA, diethylenetriamine, and triethylenetetramine.

[0019] In a further improvement to the aforementioned modified protective material, the preparation method of the silane-modified composite anti-corrosion filler comprises the following: the mass ratio of nano-silica, graphene, and mica powder is 2:1:2; the amount of silane coupling agent added is 1% to 3% of the total mass of the nano-silica, graphene, and mica powder; the average particle size of the nano-silica is 25±5 nm; the average particle size of the graphene is 0.335 nm to 4 μm; the average particle size of the mica powder is <24 μm; and the bulk density of the mica powder is <0.18 g / cm³. 3The silane coupling agent is at least one of KH-550 and γ-aminopropyltrimethoxysilane; the stirring speed is 1000 r / min to 1400 r / min; the stirring time is 25 min to 35 min; the drying is carried out at a temperature of 80℃ to 100℃; and the drying time is 2 h to 3 h.

[0020] In a further improvement of the aforementioned modified protective material, the mass ratio of component A to component B is 2:1.

[0021] The modified protective material described above, in a further improvement, comprises the following components in component A, expressed as a weight percentage: Modified epoxy resin matrix 82%–88%, Toughening compatibilizer 9%–13%, The additives are 2% to 5%, and the sum of the weight percentages of all raw materials is 100%.

[0022] The modified protective material described above, in a further improvement, comprises the following components in component B, expressed as a weight percentage: Functional compound curing agent 55%–62%, Silane-modified composite anti-corrosion filler 37%–44%, The curing accelerator is 1% to 2%, and the sum of the weight percentages of all raw materials is 100%.

[0023] The modified protective material described above, in a further improvement, comprises the following components in component A, expressed as a weight percentage: Modified epoxy resin matrix 86%, Toughening compatibilizer 11%, Additives 3%.

[0024] The modified protective material described above, in a further improvement, comprises the following components in component B, expressed as a weight percentage: Functional compound curing agent 58.5%, Silane-modified composite anti-corrosion filler 40%, Curing accelerator 1.5%.

[0025] As a general technical concept, the present invention also provides a method for preparing the above-mentioned modified protective material for marine concrete, comprising the following steps: S1. Modified epoxy resin matrix, toughening compatibilizer, and additives are added sequentially to a reactor, heated to 60℃~75℃, and stirred for 1h~2h at a speed of 70r / min~100r / min to obtain component A; functional compound curing agent and curing accelerator are added to the reactor, and stirred at a speed of 200r / min~300r / min; silane-modified composite anti-corrosion filler is added, and stirred for 1h~1.5h at a speed of 1000r / min~1400r / min to obtain component B; S2. Mix components A and B to obtain the modified protective material.

[0026] As a general technical concept, the present invention also provides an application of the modified protective material described above or the modified protective material prepared by the above preparation method in marine concrete protection.

[0027] Further improvements to the above application include the following steps: (1) Pre-treatment of the surface of marine concrete; (2) The modified protective material is sprayed onto the surface of marine concrete, and a base layer, an intermediate layer and a top layer are prepared sequentially on the surface of marine concrete to form a protective coating. (3) Maintain the protective coating on the surface of marine concrete.

[0028] The above application is further improved. In step (1), the pretreatment includes: sequentially washing, sandblasting, grinding and repairing the marine concrete so that the moisture content of the marine concrete surface is ≤6% and the flatness error is ≤2mm / m. In a further improvement to the above application, in step (2), during the preparation of the bottom layer, the coating amount of the modified protective material is controlled to be 1.1 kg / m². 2 ~1.4 kg / m 2 The thickness of the bottom layer is 700μm to 800μm; during the preparation of the intermediate layer, the coating amount of the modified protective material is controlled to be 0.6 kg / m². 2 ~0.8 kg / m 2 The thickness of the intermediate layer is 200 μm to 300 μm; during the preparation of the surface layer, the coating amount of the modified protective material is controlled to be 0.3 kg / m². 2 ~0.4 kg / m 2 The thickness of the surface layer is 300μm to 400μm.

[0029] In the above application, a further improvement is made to step (3), where the maintenance is as follows: first, maintain the product in a moisturizing environment at a temperature of 5℃~25℃ and with a film covering for 24h~48h, and then maintain it in a ventilated environment at a temperature of 30℃~40℃ and with shade, for a total maintenance time of ≥7 days.

[0030] Compared with the prior art, the advantages of the present invention are as follows: To address the technical shortcomings of existing marine concrete protective materials, such as poor adhesion, insufficient resistance to chloride ion penetration, low toughness, and weak weather resistance, this paper proposes a modified protective material for marine concrete. This material uses bisphenol A epoxy resin modified with terminal amino polyethers as the modified epoxy resin matrix. By grafting the bisphenol A epoxy resin with terminal amino polyethers, flexible ether bonds are introduced into the molecular chain, solving the problems of high brittleness and poor crack resistance after curing traditional epoxy resins. Simultaneously, it significantly improves the compatibility and alkali resistance of the material with the concrete substrate. Furthermore, with the action of a toughening compatibilizer, the adhesion between the coating and the concrete substrate is enhanced. The material exhibits improved strength and impact resistance. Furthermore, with the aid of additives (including defoamers, leveling agents, and UV absorbers), its workability and weather resistance can be optimized. Additionally, using a compound of amine-based curing agents and organosilicon-modified imidazole as a functional compound curing agent not only lowers the curing temperature (allowing for curing at room temperature from 5-35℃), but also forms a cross-linked network containing silicon-oxygen bonds after curing, enhancing the material's weather resistance and seawater erosion resistance. It also allows for control of the curing rate, overcoming the shortcomings of existing technologies such as poor compatibility between curing agents and modified epoxy groups, and the difficulty in balancing curing rate and performance. Moreover, with the action of curing accelerators… It can achieve rapid curing over a wide temperature range of 5-40℃, and after curing, it forms a denser cross-linked network, which can significantly improve the weather resistance and seawater erosion resistance of the material. In addition, using silane-modified composite fillers as silane-modified composite anti-corrosion fillers, on the one hand, a mixture of nano-silica, graphene, and mica powder is used as a composite filler. Among them, nano-silica has high hardness, graphene has high barrier properties, and mica powder has a sheet-like shielding effect. Therefore, under the combined action of these three fillers, complementary and synergistic performance can be achieved, significantly improving the mechanical properties, thermal stability, durability, and functionality of the protective material. On the one hand, through silane modification, the filler is uniformly dispersed and a dual anti-corrosion mechanism of "physical barrier + chemical passivation" is formed, which significantly reduces the permeability of chloride ions and water molecules. At the same time, the addition of silane coupling agent can improve surface activity, mechanical properties, and adhesion properties. It can be seen that under the combined action of various raw material components, the modified protective material of this invention has the characteristics of high adhesion, high toughness, and long-term corrosion resistance. As a new type of high-performance corrosion-resistant protective material, it can be widely used for the protection of marine concrete, which can ensure the stability of coating construction quality and protective effect. It has high use value and good application prospects. Detailed Implementation

[0031] The present invention will be further described below with reference to specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0032] The raw materials and instruments used in the following examples are all commercially available; unless otherwise specified, the equipment and preparation processes used are conventional equipment and conventional processes.

[0033] Example 1 A modified protective material for marine concrete includes component A and component B, wherein the weight ratio of component A to component B is 2:1.

[0034] In this embodiment, component A is composed of a modified epoxy resin matrix, a toughening compatibilizer, and additives. The weight percentages of each raw material component are as follows: Modified epoxy resin matrix 86%, Toughening compatibilizer 11%, Additives 3%.

[0035] In this embodiment, the modified epoxy resin matrix used is bisphenol A epoxy resin modified with amino-terminated polyether.

[0036] In this embodiment, the preparation method of the modified epoxy resin matrix includes the following steps: heating bisphenol A epoxy resin to 60°C, adding terminal amino polyether (which is polyetheramine T-403, commercially available) at a mass ratio of bisphenol A epoxy resin to terminal amino polyether of 100:13, stirring and reacting at a constant temperature (60°C) for 2 hours, and cooling to room temperature to obtain the modified epoxy resin matrix, which is bisphenol A epoxy resin modified with terminal amino polyether.

[0037] In other embodiments, the mass ratio of bisphenol A epoxy resin to amino-terminated polyether can also be 25:3, 50:7, 20:3, or 25:4, but is not limited to these. In this invention, by optimizing the mass ratio of bisphenol A epoxy resin to amino-terminated polyether to 25:3-4, and particularly when the mass ratio is 100:13-14, the epoxy group content can be controlled to maintain the reactivity of the epoxy. Furthermore, in this invention, the modification of bisphenol A epoxy resin using amino-terminated polyether can simultaneously meet the requirements for flexibility and modification process, which is not achieved by other modifiers.

[0038] In this embodiment, the toughening compatibilizer used is a polyurethane prepolymer, model Wanhua MDI50, a commercially available product, but not limited to this.

[0039] In this embodiment, the additives used are a mixture of defoamer, leveling agent, and ultraviolet absorber, wherein the ratio (by weight) of defoamer, leveling agent, and ultraviolet absorber is 5:9:6; the defoamer used is BYC-7204, a commercially available product, but not limited to it; the leveling agent is XY-500, a modified polysiloxane, a commercially available product, but not limited to it; the ultraviolet absorber is UV-1, an anti-ultraviolet additive that can effectively absorb ultraviolet light of 240-330nm, a commercially available product, but not limited to it.

[0040] In this embodiment, component B consists of a functional compound curing agent, a silane-modified composite anti-corrosion filler, and a curing accelerator. The weight percentages of each component are as follows: Functional compound curing agent 58.5%, Silane-modified composite anti-corrosion filler 40%, Curing accelerator 1.5%.

[0041] In this embodiment, the functional compound curing agent used is a compound of amine curing agent and organosilicon-modified imidazole, which is obtained by mixing amine curing agent and organosilicon-modified imidazole, wherein the mass ratio of amine curing agent to organosilicon-modified imidazole is 4:1.

[0042] In this embodiment, the amine curing agent used is 1,3-BAC. In other embodiments, it can also be IPDA, diethylenetriamine, triethylenetetramine, but is not limited to these.

[0043] In this embodiment, the organosilicon-modified imidazole is a derivative formed by introducing organosilicon groups (such as trimethylsilyl, triethoxysilyl, etc.) onto the imidazole molecule. For example, the organosilicon-modified imidazole can be a silane-modified polymer UL1, which is a commercially available product, but is not limited to it.

[0044] In this implementation, the organosilicon-modified imidazole used is a latent curing agent that does not react at low temperatures but only reacts when the temperature rises. Therefore, in the initial stage of the reaction, the reaction of the amine curing agent is dominant, while in the later stage, the reaction of the organosilicon imidazole is dominant. Thus, the purpose of adding organosilicon-modified imidazole is mainly to control the reaction rate so that it is not too fast. In particular, by optimizing the mass ratio of amine curing agent to organosilicon-modified imidazole to 4:1 to 3, the curing reaction rate is moderate, which is beneficial to improving the applicability of the modified protective material.

[0045] In this embodiment, the silane-modified composite anti-corrosion filler used is a silane-modified composite filler, which is a mixture of nano-silica, graphene, and mica powder.

[0046] In this embodiment, the preparation method of the silane-modified composite anti-corrosion filler includes the following steps: Nano-silica, graphene, and mica powder are mixed evenly according to a mass ratio of 2:1:2. A silane coupling agent (KH-550) is added at 2% of the total mass of nano-silica, graphene, and mica powder. The mixture is stirred at 1200 r / min for 30 min and dried at 80°C for 2 h to obtain the silane-modified composite anti-corrosion filler.

[0047] In this embodiment, the average particle size of the nano-silica used is 25±5nm. Furthermore, when the particle size of the nano-silica is too large (>30nm), it cannot effectively fill the micropores and gaps in the coating, leading to a decrease in coating density, weakened physical shielding effect, and easier penetration by corrosive media (such as water and chloride ions), thus reducing corrosion resistance. When the particle size is too small (<20nm), the nanoparticles may aggregate in the system, forming tiny "voids" or "hard spots," which in turn damages the uniformity and continuity of the coating, affecting its mechanical properties and durability.

[0048] In this embodiment, the average particle size of the graphene used is 2 μm. In other embodiments, the particle size can also be 0.335 nm, 1 nm, 5 nm, 10 nm, 20 nm, 50 nm, 100 nm, 200 nm, 300 nm, 500 nm, 800 nm, 1 μm, 1.5 μm, 1.8 μm, 2.5 μm, 3 μm, 3.5 μm, or 4 μm, but is not limited thereto.

[0049] In this invention, the graphene used has an average particle size of 0.335 nm to 4 μm, which has the following advantages: (a) Excellent physical barrier properties: The two-dimensional sheet structure of graphene can form a "maze effect" in the coating, effectively blocking the penetration of corrosive media such as water, oxygen, and chloride ions, and greatly extending the penetration path of corrosive media, which is the core of improving anti-corrosion performance.

[0050] (b) Excellent mechanical properties: Graphene has extremely high hardness, which can significantly improve the adhesion, impact resistance and flexibility of the coating, making the coating more resistant to external impact and wear, and reducing the risk of breakage and peeling.

[0051] In this embodiment, the mica powder used has an average particle size of 15 μm and a bulk density of 0.15 g / cm³. 3 In other embodiments, the average particle size of the mica powder may also be 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 12 μm, 16 μm, 19 μm, 20 μm, 22 μm, or 23 μm. In other embodiments, the bulk density of the mica powder may also be 0.01 g / cm³. 30.05g / cm 3 0.08g / cm 3 0.10 g / cm 3 0.12g / cm 3 0.14 g / cm 3 0.16 g / cm 3 0.17g / cm 3 .

[0052] In addition, when the average particle size of mica powder is too large (e.g., ≥24μm), the following adverse effects occur: (a) Decreased protective performance: As a flaky filler, mica powder mainly functions to form a physical barrier through layering, blocking the penetration of corrosive media (such as seawater, oxygen, chloride ions, etc.). If the particle size is too large, the gaps between the fillers will increase, making it impossible to form a dense protective layer, thereby reducing the corrosion resistance of the coating.

[0053] (b) Impaired physical properties: Larger particles increase the water absorption of the coating and may reduce the hardness and adhesion of the coating.

[0054] In other embodiments, the amount of silane coupling agent added may also be 1% or 3% of the total mass of nano-silica, graphene, and mica powder, but is not limited to this. In this invention, by optimizing the amount of silane coupling agent added, the surface activity, mechanical properties, and adhesive properties of the anti-corrosion material can be significantly improved. This is because when the amount of silane coupling agent added is too large, excessive silane coupling agent will lead to a decrease in the strength and water resistance of the protective material, while when the amount of silane coupling agent added is too small, a small amount of silane coupling agent is insufficient to improve the dispersibility of the filler, resulting in difficulty in improving the bonding strength.

[0055] In this embodiment, benzyl dimethylamine is used as the curing accelerator. In this invention, rapid curing over a wide temperature range of 5-40°C can be achieved under the action of the curing accelerator. Furthermore, the cured material forms a denser cross-linked network, significantly improving its weather resistance and seawater erosion resistance—a property not possessed by other accelerators.

[0056] A method for preparing the modified protective material in this embodiment includes the following steps: S1. Add 86g of modified epoxy resin matrix, 11g of toughening compatibilizer, and 3g of additives sequentially into the reactor. Start stirring at 60℃ and stir at 80r / min for 1.5h to obtain component A. Add 58.5g of functional compound curing agent and 1.5g of curing accelerator into the reactor and stir at 200r / min until uniformly mixed. Add 40g of silane-modified composite anti-corrosion filler and disperse at 1200r / min for 1h to obtain component B.

[0057] S2. Mix component A and component B at a weight ratio of 2:1 at 25°C to obtain the modified protective material.

[0058] The application of the modified protective material prepared in this embodiment in marine concrete protection includes the following steps: (1) Pretreatment of the marine concrete surface, specifically: High-pressure water jets are used to wash, sandblast, and grind the marine concrete to control the roughness to Sa2.5 grade or 30-50μm, and defects are repaired to ensure that the moisture content of the marine concrete surface is ≤6% and the flatness error is ≤2mm / m.

[0059] (2) The modified protective material is sprayed onto the surface of the marine concrete. Specifically, the coating amount is controlled to be 1.1 kg / m². 2 A base layer with a thickness of 700 μm was prepared on the surface of marine concrete, and then the coating amount was controlled at 0.6 kg / m². 2 An intermediate layer with a thickness of 200 μm was prepared on the surface of the base layer, and the final coating amount was controlled to be 0.3 kg / m². 2 A top layer with a thickness of 400 μm is prepared on the surface of the intermediate layer, which ultimately forms a protective coating on the marine concrete surface.

[0060] (3) The protective coating on the surface of marine concrete is to be cured by first keeping it moist for 24 hours at a temperature of 25°C and with a film covering, and then ventilating it at a temperature of 40°C and with shade. The total curing time is 7 days.

[0061] The performance of the protective coating prepared in Example 1 was tested, and the results are shown in Table 1.

[0062] Example 2 A modified protective material for marine concrete includes component A and component B, wherein the weight ratio of component A to component B is 2:1.

[0063] In this embodiment, component A is composed of a modified epoxy resin matrix, a toughening compatibilizer, and additives. The weight percentages of each raw material component are as follows: Modified epoxy resin matrix 83%, Toughening compatibilizer 12%, Additives 5%.

[0064] In this embodiment, the modified epoxy resin matrix used is bisphenol A epoxy resin modified with amino-terminated polyether.

[0065] In this embodiment, the preparation method of the modified epoxy resin matrix includes the following steps: heating bisphenol A epoxy resin to 60°C, adding terminal amino polyether (which is polyetheramine T-403, commercially available) at a mass ratio of bisphenol A epoxy resin to terminal amino polyether of 100:13, stirring and reacting at a constant temperature (60°C) for 2 h, and cooling to room temperature to obtain the modified epoxy resin matrix.

[0066] In this embodiment, the toughening compatibilizer used is a polyurethane prepolymer, model Wanhua MDI50, a commercially available product, but not limited to this.

[0067] In this embodiment, the additives used are a mixture of defoamer, leveling agent, and ultraviolet absorber, wherein the ratio (by weight) of defoamer, leveling agent, and ultraviolet absorber is 5:9:6; the defoamer used is BYC-7204, a commercially available product, but not limited to it; the leveling agent is XY-500, a modified polysiloxane, a commercially available product, but not limited to it; the ultraviolet absorber is UV-1, an anti-ultraviolet additive that can effectively absorb ultraviolet light of 240-330nm, a commercially available product, but not limited to it.

[0068] In this embodiment, component B consists of a functional compound curing agent, a silane-modified composite anti-corrosion filler, and a curing accelerator. The weight percentages of each component are as follows: 60% functional compound curing agent Silane-modified composite anti-corrosion filler 38%, Curing accelerator 2%.

[0069] In this embodiment, the functional compound curing agent used is a compound of amine curing agent and organosilicon-modified imidazole, which is obtained by mixing amine curing agent and organosilicon-modified imidazole, wherein the mass ratio of amine curing agent to organosilicon-modified imidazole is 4:1.

[0070] In this embodiment, the amine curing agent used is 1,3-BAC. In other embodiments, it can also be IPDA, diethylenetriamine, triethylenetetramine, but is not limited to these.

[0071] In this embodiment, the organosilicon-modified imidazole is a derivative formed by introducing organosilicon groups (such as trimethylsilyl, triethoxysilyl, etc.) onto the imidazole molecule. For example, the organosilicon-modified imidazole can be a silane-modified polymer UL1, which is a commercially available product, but is not limited to it.

[0072] In this embodiment, the silane-modified composite anti-corrosion filler used is a silane-modified composite filler, which is a mixture of nano-silica, graphene, and mica powder.

[0073] In this embodiment, the preparation method of the silane-modified composite anti-corrosion filler includes the following steps: the nano-silica, graphene, and mica powder are mixed evenly according to a mass ratio of 2:1:2; the silane coupling agent (KH-550) is added at 2% of the total mass of the nano-silica, graphene, and mica powder; the mixture is stirred at a speed of 1200 r / min for 30 min; and dried at a temperature of 80℃ for 2 h to obtain the silane-modified composite anti-corrosion filler.

[0074] In this embodiment, the average particle size of the nano-silica used is 25±5nm.

[0075] In this embodiment, the graphene used has an average particle size of 2 μm.

[0076] In this embodiment, the mica powder used has an average particle size of 15 μm and a bulk density of 0.15 g / cm³. 3 .

[0077] In this embodiment, the curing accelerator used is benzyldimethylamine.

[0078] A method for preparing the modified protective material in this embodiment includes the following steps: S1. Add 83g of modified epoxy resin matrix, 12g of toughening compatibilizer, and 5g of additives to the reactor in sequence. Start stirring at 60℃ and stir at 80r / min for 1.5h to obtain component A. Add 60g of functional compound curing agent and 2g of curing accelerator to the reactor and stir at 200r / min until uniformly mixed. Add 38g of silane-modified composite anti-corrosion filler and disperse at 1200r / min for 1h to obtain component B.

[0079] S2. Mix component A and component B at a weight ratio of 2:1 at 25°C to obtain the modified protective material.

[0080] The application of the modified protective material prepared in this embodiment in marine concrete protection includes the following steps: (1) Pretreatment of the marine concrete surface, specifically: High-pressure water jets are used to wash, sandblast, and grind the marine concrete to control the roughness to Sa2.5 grade or 30-50μm, and defects are repaired to ensure that the moisture content of the marine concrete surface is ≤6% and the flatness error is ≤2mm / m.

[0081] (2) The modified protective material is sprayed onto the surface of the marine concrete. Specifically, the coating amount is controlled to be 1.1 kg / m². 2A base layer with a thickness of 700 μm was prepared on the surface of marine concrete, and then the coating amount was controlled at 0.6 kg / m². 2 An intermediate layer with a thickness of 200 μm was prepared on the surface of the base layer, and the final coating amount was controlled to be 0.3 kg / m². 2 A top layer with a thickness of 400 μm is prepared on the surface of the intermediate layer, which ultimately forms a protective coating on the marine concrete surface.

[0082] (3) The protective coating on the surface of marine concrete is to be cured by first keeping it moist for 48 hours at a temperature of 5°C and with a film covering, and then ventilating it at a temperature of 40°C and with shade. The total curing time is 7 days.

[0083] The performance of the protective coating prepared in Example 2 was tested, and the results are shown in Table 1.

[0084] In addition, in Example 2, after 48 hours of moisturizing and curing with a film, the curing completion rate was 98.7%, and the adhesion remained at level 0.

[0085] Comparative Example 1 A modified protective material for marine concrete is basically the same as that in Example 1, except that in Comparative Example 1, unmodified bisphenol A epoxy resin is used instead of amino-terminated polyether modified bisphenol A epoxy resin.

[0086] The performance of the protective coating prepared in Comparative Example 1 was tested, and the results are shown in Table 1.

[0087] In addition, in Comparative Example 1, the coating became brittle after curing, with a 28% decrease in impact strength, and blistering occurred after immersion in seawater for 500 hours.

[0088] Table 1. Performance comparison of modified protective materials and protective coatings in Examples 1-2 and Comparative Example 1

[0089] As shown in Table 1, the modification with terminal amino polyethers in this invention significantly improves the adhesion, toughness, and long-term corrosion resistance of the protective material. Furthermore, the protective coating prepared from the modified protective material of this invention should have a smooth and flat surface, free from defects such as missed areas, pinholes, bubbles, cracks, and peeling, and should have a uniform color. In addition, the adhesion test (cross-cut test) of the protective coating reaches level 0, indicating very high adhesion and stable adhesion to marine concrete surfaces; the chloride ion permeability coefficient is ≤1.0×10⁻⁶. - 12 m 2It exhibits excellent corrosion resistance, showing no blistering or peeling after 1000 hours of seawater immersion, effectively preventing seawater corrosion; its gloss loss rate is ≤5%, and its discoloration grade is ≤1, demonstrating a very long service life and maintaining the performance of marine concrete for a long time.

[0090] As can be seen from the above results, the combined effect of the various raw material components in this invention enables the modified protective material to possess characteristics such as high adhesion, high toughness, and long-term corrosion resistance. As a high-performance new type of corrosion-resistant protective material, it can be widely used for the protection of marine concrete, ensuring the stability of coating construction quality and protective effect. It has high use value and good application prospects.

[0091] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A modified protective material for marine concrete, characterized in that, The product comprises component A and component B. Component A consists of a modified epoxy resin matrix, a toughening compatibilizer, and additives. Component B consists of a functional compound curing agent, a silane-modified composite anti-corrosion filler, and a curing accelerator. The modified epoxy resin matrix is ​​an amino-terminated polyether-modified bisphenol A epoxy resin. The functional compound curing agent is a compound of an amine curing agent and an organosilicon-modified imidazole. The silane-modified composite anti-corrosion filler is a silane-modified composite filler. The composite filler is a mixture of nano-silica, graphene, and mica powder.

2. The modified protective material according to claim 1, characterized in that, The method for preparing the modified epoxy resin matrix includes the following steps: heating bisphenol A epoxy resin to 60℃~70℃, adding terminal amino polyether in proportion, stirring at a constant temperature for 2 h~3 h, and cooling to room temperature to obtain the modified epoxy resin matrix; the mass ratio of bisphenol A epoxy resin to terminal amino polyether is 25∶3~4. The toughening compatibilizer is a polyurethane prepolymer; The additive is a mixture of defoamer, leveling agent, and ultraviolet absorber; the mass ratio of the defoamer, leveling agent, and ultraviolet absorber is 5:9:

6. The functional compound curing agent is obtained by mixing an amine curing agent with an organosilicon-modified imidazole; the mass ratio of the amine curing agent to the organosilicon-modified imidazole is 4:1 to 3. The preparation method of the silane-modified composite anti-corrosion filler includes the following steps: mixing nano-silica, graphene, and mica powder, adding silane coupling agent, stirring, and drying to obtain the silane-modified composite anti-corrosion filler. The curing accelerator is benzyldimethylamine.

3. The modified protective material according to claim 2, characterized in that, The mass ratio of the bisphenol A epoxy resin to the amino-terminated polyether is 100:13-14; the amino-terminated polyether is polyetheramine T-403. The defoamer is BYC-7204; the defoamer is BYC-7204; the ultraviolet absorber is UV-1; The amine curing agent is at least one of 1,3-BAC, IPDA, diethylenetriamine, and triethylenetetramine. In the preparation method of the silane-modified composite anti-corrosion filler, the mass ratio of nano-silica, graphene, and mica powder is 2:1:2; the amount of silane coupling agent added is 1% to 3% of the total mass of nano-silica, graphene, and mica powder; the average particle size of the nano-silica is 25±5 nm; the average particle size of the graphene is 0.335 nm to 4 μm; the average particle size of the mica powder is <24 μm; and the bulk density of the mica powder is <0.18 g / cm³. 3 The silane coupling agent is at least one of KH-550 and γ-aminopropyltrimethoxysilane; the stirring speed is 1000 r / min to 1400 r / min; the stirring time is 25 min to 35 min; the drying is carried out at a temperature of 80℃ to 100℃; and the drying time is 2 h to 3 h.

4. The modified protective material according to claim 3, characterized in that, The mass ratio of component A to component B is 2:

1.

5. The modified protective material according to any one of claims 1 to 4, characterized in that, The raw material components in component A are expressed as a weight percentage as follows: Modified epoxy resin matrix 82%–88%, Toughening compatibilizer 9%–13%, The additives are 2% to 5%, and the sum of the weight percentages of all raw materials is 100%. The raw material components in component B, expressed as a weight percentage, are as follows: Functional compound curing agent 55%–62%, Silane-modified composite anti-corrosion filler 37%–44%, The curing accelerator is 1% to 2%, and the sum of the weight percentages of all raw materials is 100%.

6. The modified protective material according to claim 5, characterized in that, The raw material components in component A are expressed as a weight percentage as follows: Modified epoxy resin matrix 86%, Toughening compatibilizer 11%, 3% of the additives; The raw material components in component B, expressed as a weight percentage, are as follows: Functional compound curing agent 58.5%, Silane-modified composite anti-corrosion filler 40%, Curing accelerator 1.5%.

7. A method for preparing a modified protective material for marine concrete as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Modified epoxy resin matrix, toughening compatibilizer, and additives are added sequentially to a reactor, heated to 60℃~75℃, and stirred for 1h~2h at a speed of 70r / min~100r / min to obtain component A; functional compound curing agent and curing accelerator are added to the reactor, and stirred at a speed of 200r / min~300r / min; silane-modified composite anti-corrosion filler is added, and stirred for 1h~1.5h at a speed of 1000r / min~1400r / min to obtain component B; S2. Mix components A and B to obtain the modified protective material.

8. The application of a modified protective material as described in any one of claims 1 to 6 or a modified protective material prepared by the preparation method described in claim 7 in marine concrete protection.

9. The application according to claim 8, characterized in that, Includes the following steps: (1) Pre-treatment of the surface of marine concrete; (2) The modified protective material is sprayed onto the surface of marine concrete, and a base layer, an intermediate layer and a top layer are prepared sequentially on the surface of marine concrete to form a protective coating. (3) Maintain the protective coating on the surface of marine concrete.

10. The application according to claim 9, characterized in that, In step (1), the pretreatment includes: sequentially washing, sandblasting, grinding and repairing the marine concrete to make the surface moisture content ≤6% and the flatness error ≤2mm / m; In step (2), during the preparation of the bottom layer, the coating amount of the modified protective material is controlled to be 1.1 kg / m². 2 ~1.4kg / m 2 The thickness of the bottom layer is 700μm to 800μm; during the preparation of the intermediate layer, the coating amount of the modified protective material is controlled to be 0.6 kg / m². 2 ~0.8 kg / m 2 The thickness of the intermediate layer is 200 μm to 300 μm; during the preparation of the surface layer, the coating amount of the modified protective material is controlled to be 0.3 kg / m². 2 ~0.4 kg / m 2 The thickness of the surface layer is 300μm to 400μm. In step (3), the maintenance is as follows: first, maintain the moisture for 24h to 48h under the condition of 5℃~25℃ and film covering, and then maintain the ventilation under the condition of 30℃~40℃ and shading, with a total maintenance time of ≥7 days.

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