A two-component self-repairing microcapsule material and preparation method thereof

Abstract

The present invention discloses a two-component self-repairing microcapsule material and a preparation method thereof, which belong to the field of microcapsule technology. It addresses the problem that the repair agent or curing agent in the current microcapsule material is not fully reacted and the repair efficiency is low. The present invention discloses that the primary microcapsule core material is composed of a repair agent microcapsule of component A and a curing agent of component B, wherein the repair agent microcapsule of component A includes a secondary core material and a secondary wall material coated on the outside of the secondary core material. The preparation method adopts a three-step method: first, a single-layer polyurethane-diisocyanate microcapsule is prepared by interfacial polymerization, and then a double-shell component A phenolic / polyurethane-diisocyanate repair agent microcapsule is prepared by in-situ polymerization, and finally, the component A repair agent microcapsule and the component B curing agent are microencapsulated by in-situ polymerization to prepare a two-component self-repairing microcapsule material. The material of the present invention has in-situ adaptation of the repair agent and the curing agent, so that the self-repair response is fast and the effect is accurate and efficient.

Description

Technical Field

[0001] The present invention belongs to the technical field of microcapsules, and in particular relates to a two-component self-repairing microcapsule material and a preparation method thereof. Background Art

[0002] Among corrosion prevention methods, organic coatings, which block corrosive ions and moisture from entering metals, are the most widely used protection method, accounting for approximately two-thirds of corrosion protection costs. However, during transportation and use, they are inevitably subject to environmental and mechanical damage, which can severely compromise the coating's protective properties. Damage can take the form of localized scratches or delamination, or stress-related macrocracks. Furthermore, adhesion failure caused by environmental factors such as UV rays, heat, oxygen, moisture, and ions can further degrade the coating's general protective and aesthetic properties. Without timely and effective repair, corrosive media can rapidly penetrate these damaged areas, ultimately leading to premature coating failure. Therefore, there is a significant demand for a new generation of anti-corrosion coatings that intelligently respond to damage, possess self-repair capabilities, and delay corrosion of metal substrates. These emerging smart coatings exhibit self-healing properties by incorporating microcapsules of exogenous polymerizable repair agents. When the coating is damaged, the microcapsules rupture under mechanical impact, releasing the repair agent, which then polymerizes to form a protective film, restoring the coating's barrier properties. The most commonly used anti-corrosion self-healing microcapsules are isocyanate microcapsules. Because they can react with water in the environment to form polymers to repair cracked surfaces, they can be used as a single microcapsule system in anti-corrosion coatings. However, the reactivity of water in the environment with isocyanate groups is low, and the interfacial polymerization repair process is long, which cannot guarantee the timely repair of the cracked surface and thus corrosion. In addition, the amount of water in the environment is unstable, and there may be a low content of water molecules on the cracked surface, which prevents the isocyanate groups from fully reacting, resulting in insufficient polymer cross-linking density, low sealing of the repaired surface, and only partial repair, resulting in a loss of the barrier function of the coating and corrosion. Therefore, improving the reactivity of the isocyanate group, shortening the repair time of the cracked surface, quickly and promptly repairing the fractured surface of the coating, and avoiding the occurrence of corrosion as early as possible are the keys to solving the above problems.

[0003] Therefore, amine curing agents with higher reactivity toward isocyanate groups are introduced. Their active hydrogen atoms react rapidly with isocyanate groups, resulting in a high crosslink density and strong bonding strength, enabling rapid and timely repair of cracked surfaces. Amine curing agents are typically introduced in the form of microcapsules. A dual microcapsule system, composed of isocyanate repair agent microcapsules and amine curing agent microcapsules, is pre-embedded in the epoxy resin coating. Upon microcracks forming, the repair agent microcapsules and amine curing agent microcapsules rupture, causing a polymerization reaction that repairs the cracked surface and isolates the substrate from the environment, preventing corrosion. However, a dual microcapsule system requires both microcapsules to rupture simultaneously and crosslink at the same cracked surface to achieve a repair effect. This is only an ideal scenario; in reality, either the repair agent or the curing agent may be in excess, leading to incomplete reaction and localized failure to react, resulting in low repair efficiency. Furthermore, the pre-embedded microcapsules significantly impact substrate properties, reducing adhesion between the epoxy coating and the substrate and peel strength, rendering the self-healing coating ineffective. Summary of the Invention

[0004] In response to the current anti-corrosion self-repairing microcapsules, because their two components belong to different types of microcapsules, the cracks must extend to the two microcapsules rupture, and the two components must meet at the crack surface to have a repair effect. Their response repair performance is relatively long in both spatial and temporal dimensions, and the two components are not mixed sufficiently and evenly. The present invention provides a two-component self-repairing microcapsule material and a preparation method thereof, which solves the problem that the repair agent or curing agent in the current microcapsule material does not react sufficiently and has low repair efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A two-component self-repairing microcapsule material, comprising a primary microcapsule core material and a primary wall material coated on the primary microcapsule core material;

[0007] The primary microcapsule core material is composed of component A of the repair agent microcapsule and component B of the curing agent, wherein the component A of the repair agent microcapsule includes a secondary core material and a secondary wall material coated outside the secondary core material;

[0008] The primary wall material is epoxy resin; the repair agent microcapsules of component A are phenolic / polyurethane-isophorone diisocyanate microcapsules;

[0009] Furthermore, the secondary wall material of the repair agent microcapsules of component A is phenolic / polyurethane resin, and the secondary core material is isophorone diisocyanate.

[0010] Furthermore, the curing agent of component B is a polyamine; specifically, aliphatic amine or aromatic amine miscible with water, preferably one or more of ethylenediamine, diethylenetriamine, and triethylenetetramine.

[0011] Furthermore, the particle size of the self-repairing microcapsule material is 40 to 2000 microns, and the thickness of the primary wall material is 3 to 70 microns.

[0012] A method for preparing a two-component self-repairing microcapsule material comprises the following steps:

[0013] Step 1: Deionized water and gum arabic are stirred at room temperature to form an aqueous phase I; a toluene diisocyanate prepolymer L-75, isophorone diisocyanate, and ethyl acetate are mixed to form a uniform oil phase I; the oil phase I is then added to the aqueous phase I and emulsified and stirred to form an oil-in-water emulsion; 1,4-butanediol is dropwise added and stirred at 50° C. to react; and polyurethane-isophorone diisocyanate microcapsules are obtained by filtering, washing, and drying.

[0014] Step 2: Mixing an alcohol-soluble phenolic resin, anhydrous ethanol, and an NL curing agent to form a solution; adding polyurethane-isophorone diisocyanate microcapsules to the solution formed by mixing the alcohol-soluble phenolic resin, anhydrous ethanol, and the NL curing agent to form a solid-liquid mixture I; mixing dimethyl silicone oil and hydrophobic nano-silica with a high-speed shearing machine to form a continuous phase I; adding the solid-liquid mixture I dropwise to the continuous phase at room temperature, stirring and reacting, and filtering, washing, and drying to obtain the phenolic / polyurethane-isophorone diisocyanate microcapsules of component A;

[0015] Step 3: Dissolve the polyamine in deionized water to prepare the curing agent of component B, that is, form aqueous phase II; after mixing the epoxy resin and ethylenediamine, add nano-silica and stir evenly to form oil phase II; add aqueous phase II to oil phase II and emulsify and stir to form an emulsion; add nano-silica to dimethyl silicone oil and dissolve it in continuous phase II by high-speed stirring; then add phenolic / polyurethane-isophorone diisocyanate microcapsules to the emulsion to form mixture II; add mixture II dropwise to continuous phase II at room temperature and stir to react, and obtain a two-component self-healing microcapsule material after filtering, washing and drying.

[0016] Furthermore, in step 1, the mass ratio of deionized water to gum arabic is 100:4 to 100:8; in step 1, the mass ratio of the prepolymer L-75 of isophorone diisocyanate and toluene diisocyanate to ethyl acetate is 4:1:1; in step 1, the mass ratio of the oil phase I to the water phase I is 1:3 to 1:5; and in step 1, the mass ratio of 1,4-butanediol to isophorone diisocyanate is 15:100 to 25:100.

[0017] Furthermore, the stirring speed for forming aqueous phase I in step 1 is 400-800 r / min, and the stirring time is 3-5 h; the emulsification stirring speed for forming an oil-in-water emulsion in step 1 is 600-1000 r / min, and the emulsification time is 20-40 min; and the reaction time for stirring the reaction at 50° C. after adding 1,4-butanediol in step 1 is 1-3 h.

[0018] Furthermore, in step 2, the mass ratio of the phenolic resin, anhydrous ethanol and NL curing agent is 100:200:15; the mass ratio of the polyurethane-isophorone diisocyanate microcapsules to the dimethyl silicone oil in step 2 is 1:100~5:100, and the mass ratio of the polyurethane-isophorone diisocyanate microcapsules to the phenolic resin in step 2 is 2:1~1:2; the mass ratio of the dimethyl silicone oil to the nano-silica in step 2 is 100:2~100:4.

[0019] Furthermore, in step 2, the stirring speed of the high-speed shearing machine to mix and stir uniformly to form a continuous phase I is 10,000-20,000 r / min, and the stirring time is 1-3 min; in step 2, the stirring speed of adding the solid-liquid mixture I dropwise to the continuous phase I for stirring reaction is 400-700 r / min, and the reaction time is 6-12 h.

[0020] Furthermore, in step 3, the mass ratio of deionized water to curing agent is 5 to 50:100; the mass ratio of epoxy resin, ethylenediamine, and nano-silica in step 3 is 100:10:4; the mass ratio of aqueous phase II to oil phase II in step 3 is 1:6 to 1:1; the mass ratio of phenolic / polyurethane-isophorone diisocyanate microcapsules to emulsion in step 3 is 5:100 to 30:100; the mass ratio of dimethyl silicone oil to nano-silica in step 3 is 100:2 to 100:4; and the mass ratio of mixture II to dimethyl silicone oil in step 3 is 1:100 to 15:100.

[0021] Furthermore, the stirring speed of emulsifying and stirring to form an emulsion in step 3 is 400~800r / min, and the emulsification time is 10~30min; the stirring speed of high-speed stirring and dissolving to form a continuous phase II in step 3 is 10000~20000r / min, and the stirring time is 1~3min; the stirring speed of adding mixture II dropwise to the continuous phase II in step 3 for stirring reaction is 150~600r / min, and the reaction time is 6~24h.

[0022] The microcapsule material encapsulates the isocyanate repair agent component and the amine curing agent component in a microcapsule at the same time, ensuring that when microcracks occur, the rupture of any single microcapsule will release the repair agent and curing agent at the same time, allowing the polymerization reaction to occur quickly and fully in the micro area, repairing the microcracks as soon as possible and avoiding the expansion of the cracks, thereby making full use of each microcapsule, improving the repair efficiency, and reducing the adverse effects of excessive introduction of microcapsules on the coating.

[0023] This preparation method simultaneously encapsulates the repair agent microcapsules (Component A) and the amine curing agent (Component B) within the same microcapsule, achieving a precise match between the individual microcapsules' repair agent and curing agent. This ensures the proper alignment and concentration of the two components when the microcapsule ruptures. This preparation method allows the introduction of the repair agent microcapsules without disrupting the preparation of the original amine curing agent microcapsules, achieving a single-microcapsule, dual-component dual-microcapsule system and shortening the overall self-healing coating process. It also accelerates the repair reaction and improves self-healing efficiency, achieving the fastest and most effective repair of microcracks with minimal use of repair agent.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) The two-component self-healing microcapsule material provided by the present invention has a repair agent of component A being isocyanate and a curing agent of component B being an amine curing agent. The active hydrogen atoms of amines have high reactivity with isocyanate groups, which can achieve rapid curing and repair microcracks as early as possible at the beginning of their generation, thereby preventing them from further expansion and causing greater harm, thereby ensuring the anti-corrosion effect of the coating.

[0026] (2) The two-component self-healing microcapsule material provided by the present invention contains both a repair agent (component A) and a curing agent (component B), ensuring that after a single microcapsule is broken, the repair agent and the curing agent meet and the content ratio of the two is appropriate, thereby achieving optimal utilization of the repair agent and the curing agent.

[0027] (3) The preparation method of the two-component self-healing microcapsule material provided by the present invention introduces the repair agent microcapsules of component A in advance during the process of preparing the curing agent microcapsules of component B. This not only shortens the entire self-healing coating preparation process, but also enables a certain degree of precise control of the contents of components A and B, making the ratio of the two more scientific and reasonable, thereby optimizing and improving the self-healing effect of the self-healing coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of two-component self-healing microcapsule material.

[0029] Figure 2 This is the OM analysis diagram of the two-component self-healing microcapsule material in Example 1.

[0030] Figure 3 This is the SEM analysis diagram of the two-component self-repairing microcapsule material in Example 1.

[0031] Figure 4 This is a SEM analysis diagram of the internal structure of the two-component self-repairing microcapsule material in Example 1.

[0032] Figure 5 Schematic diagram of the thermogravimetric analysis curve of the two-component self-healing microcapsule material in Example 1.

[0033] Figure 6 Schematic diagram of differential scanning calorimetry analysis of the two-component self-healing microcapsule material in Example 1.

[0034] Figure 7 This is a graph showing the change in core material content of the two-component self-repairing microcapsule material in Example 1 before and after solvent immersion.

[0035] Figure 8 This is a graph showing the change in core material content of polyurethane-isophorone diisocyanate microcapsule material before and after solvent immersion.

[0036] Figure 9 This is an SEM image of the self-repairing coating prepared using the two-component self-repairing microcapsule material in Example 3 after the scratch was cleaned with ethyl acetate for 5 minutes.

[0037] Figure 10 SEM image of the self-healing coating doped with polyurethane-isophorone diisocyanate microcapsules as a comparison sample after cleaning with ethyl acetate for 5 minutes after the scratch.

[0038] Figure 11 This is an optical photograph of a self-repairing coating prepared using the two-component self-repairing microcapsule material in Example 3 and a self-repairing coating doped with polyurethane-isophorone diisocyanate microcapsules as a comparison sample after the scratch was cleaned with ethyl acetate for 5 minutes and then corroded with salt water for 24 hours. DETAILED DESCRIPTION

[0039] The present invention will be described in detail below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0040] The present invention discloses a two-component self-repairing microcapsule material, comprising a primary wall material and a primary microcapsule core material coated in the primary wall material, wherein the primary microcapsule core material is composed of a repair agent microcapsule of component A and a curing agent of component B, wherein the repair agent microcapsule of component A comprises a secondary wall material and a secondary core material coated in the secondary wall material.

[0041] The primary wall material is epoxy resin, the curing agent of component B is polyamine, the secondary wall material of the repair agent microcapsule of component A is phenolic / polyurethane resin, and the secondary core material is isophorone diisocyanate.

[0042] The particle size of the microcapsule is 40 to 2000 microns, and the thickness of the primary wall material is 3 to 70 microns. Example 1

[0043] A method for preparing a two-component self-repairing microcapsule material comprises the following steps:

[0044] Step 1: Stirring deionized water and gum arabic at room temperature for 3 hours at a stirring speed of 800 r / min to form an aqueous phase I; mixing a prepolymer of toluene diisocyanate L-75, isophorone diisocyanate, and ethyl acetate to form a uniform oil phase I; then adding the oil phase I to the aqueous phase I and emulsifying and stirring at a speed of 1000 r / min for 20 minutes to form an oil-in-water emulsion; adding 1,4-butanediol dropwise and stirring at 50° C. for 1 hour; and filtering, washing, and drying to obtain polyurethane-isophorone diisocyanate microcapsules;

[0045] Step 2: Mixing an alcohol-soluble phenolic resin, anhydrous ethanol, and an NL curing agent to form a solution; adding polyurethane-isophorone diisocyanate microcapsules to the solution formed by mixing the alcohol-soluble phenolic resin, anhydrous ethanol, and the NL curing agent to form a solid-liquid mixture I; mixing dimethyl silicone oil and hydrophobic nano-silica with a high-speed shearing machine at a speed of 10,000 r / min for 3 minutes to uniformly form a continuous phase I; adding the solid-liquid mixture I dropwise to the continuous phase at room temperature and stirring at a speed of 400 r / min for 6 hours, and then filtering, washing, and drying to obtain phenolic / polyurethane-isophorone diisocyanate microcapsules as component A;

[0046] Step 3: Dissolve polyamine (diethylenetriamine) in deionized water to prepare the curing agent of component B, that is, form aqueous phase II; after mixing the epoxy resin and ethylenediamine, add nano-silica and stir evenly to form oil phase II; add aqueous phase II to oil phase II and emulsify and stir at a speed of 400 r / min for 30 minutes to form an emulsion; add nano-silica to dimethyl silicone oil and dissolve it at a high-speed stirring speed of 10,000 r / min for 3 minutes to obtain continuous phase II; then add phenolic / polyurethane-isophorone diisocyanate microcapsules to the emulsion to form mixture II; add mixture II dropwise to continuous phase II at room temperature and stir at a speed of 300 r / min for 6 hours, and obtain a two-component self-healing microcapsule material after filtering, washing and drying.

[0047] The mass ratio of deionized water to gum arabic in step 1 is 100:4, the mass ratio of isophorone diisocyanate, L-75 and ethyl acetate in step 1 is 4:1:1; the mass ratio of oil phase I to water phase I in step 1 is 1:3; the mass ratio of 1,4-butanediol to isophorone diisocyanate in step 1 is 15:100.

[0048] In step 2, the mass ratio of alcohol-soluble phenolic resin, anhydrous ethanol and NL curing agent is 100:200:15; the mass ratio of polyurethane-isophorone diisocyanate microcapsules to dimethyl silicone oil is 1:100, and the mass ratio to phenolic resin is 2:1; the mass ratio of dimethyl silicone oil to nano-silica is 100:2.

[0049] In step 3, the mass ratio of deionized water to curing agent is 5%; the mass ratio of epoxy resin, ethylenediamine, and nano-silica is 100:10:4; the mass ratio of aqueous phase II to oil phase II is 1:6; the mass ratio of phenolic / polyurethane-isophorone diisocyanate microcapsules to emulsion is 5:100; the mass ratio of dimethyl silicone oil to hydrophobic nano-silica is 100:2; and the mass ratio of mixture II to dimethyl silicone oil is 1:100.

[0050] The particle size distribution of the two-component self-repairing microcapsule material obtained in this embodiment is between 40 and 200 microns, the thickness of the primary wall material is 10 to 50 microns, the microcapsule core material content is 22%, and the interior contains component A and component B, and has reactive properties, such as Figure 4 The SEM analysis of the internal structure of the two-component self-healing microcapsule material is shown in the figure.

[0051] The two-component self-healing microcapsule material obtained in this example was subjected to optical microscopy (OM), scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and stability analysis. Figure 2 The results of the SEM analysis are shown in the OM analysis diagram. Figure 3 The SEM analysis of the results of thermogravimetric analysis is shown in Figure 5 The results of differential scanning calorimetry analysis are shown in the schematic diagram of the thermogravimetric analysis curve. Figure 6 Schematic diagram of differential scanning calorimetry analysis.

[0052] The microcapsules prepared in this example were immersed in four solvents: n-hexane, ethyl acetate, ethanol, and deionized water for 24 hours, and then dried and the remaining core material content of the microcapsules was measured to characterize the stability of the two-component self-repairing microcapsule material. Figure 7 Shown is a graph showing the change in core material content of the two-component self-healing microcapsule material before and after solvent immersion.

[0053] In a comparative test, the polyurethane-isophorone diisocyanate microcapsules obtained in step 1 were immersed in four solvents: n-hexane, ethyl acetate, ethanol, and deionized water for 24 hours, and then dried to measure the remaining core material content of the microcapsules. Figure 8 Shown is a graph showing the change in core material content of the comparative microcapsule material before and after solvent immersion. Example 2

[0054] The present invention discloses a method for preparing a two-component self-repairing microcapsule material, which is the same as Example 1, except that:

[0055] In step 1, the mass ratio of deionized water to gum arabic was 100:6, the stirring speed was 600 r / min, and the stirring time was 4 hours. The mass ratio of the oil phase I to the aqueous phase I was 1:4. The emulsification stirring speed was 800 r / min, and the emulsification time was 30 minutes. The ratio of the added 1,4-butanediol to isophorone diisocyanate was 20:100, and the system reaction time was 2 hours.

[0056] In step 2, the mass ratio of polyurethane-isophorone diisocyanate microcapsules to dimethyl silicone oil is 3:100, and the mass ratio of polyurethane-isophorone diisocyanate microcapsules to phenolic resin is 1:1. The mass ratio of dimethyl silicone oil to nano-silica is 100:3. The high-speed stirring speed is 10,000 r / min, and the stirring time is 2 minutes. The reaction stirring speed is 500 r / min, and the reaction time is 10 hours.

[0057] In step 3, the ratio of deionized water to amine curing agent was 10%. The mass ratio of aqueous phase II to oil phase II was 1:5. The emulsification stirring speed was 600 r / min, and the emulsification time was 20 minutes. The mass ratio of component A repair agent microcapsules to the emulsion was 15:100. The mass ratio of dimethyl silicone oil to hydrophobic nanosilica was 100:3. The high-speed stirring speed was 10,000 r / min, and the stirring time was 2 minutes. The mass ratio of the mixture to dimethyl silicone oil was 5:100. The reaction stirring speed was 400 r / min, and the reaction time was 12 hours. Example 3

[0058] The present invention discloses a method for preparing a two-component self-repairing microcapsule material, which is the same as Example 1, except that:

[0059] In step 1, the mass ratio of deionized water to gum arabic was 100:5, the stirring speed was 500 r / min, and the stirring time was 3 hours. The mass ratio of the oil phase I to the aqueous phase I was 1:5. The emulsification stirring speed was 700 r / min, and the emulsification time was 25 minutes. The ratio of the added 1,4-butanediol to isophorone diisocyanate was 25:100, and the system reaction time was 1.5 hours.

[0060] In step 2, the mass ratio of polyurethane-isophorone diisocyanate microcapsules to dimethyl silicone oil is 4:100, and the mass ratio of polyurethane-isophorone diisocyanate microcapsules to phenolic resin is 2:1. The mass ratio of dimethyl silicone oil to nano-silica is 100:2. The high-speed stirring speed is 20,000 r / min, and the stirring time is 1 minute. The reaction stirring speed is 600 r / min, and the reaction time is 8 hours.

[0061] In step 3, the ratio of deionized water to amine curing agent was 8%. The mass ratio of aqueous phase II to oil phase II was 1:6. The emulsification stirring speed was 700 r / min, and the emulsification time was 25 minutes. The mass ratio of component A repair agent microcapsules to the emulsion was 20:100. The mass ratio of dimethyl silicone oil to hydrophobic nanosilica was 100:2. The high-speed stirring speed was 20,000 r / min, and the stirring time was 1 minute. The mass ratio of the mixture to dimethyl silicone oil was 8:100. The reaction stirring speed was 150 r / min, and the reaction time was 18 hours.

[0062] The two-component self-repairing microcapsule material obtained in this example was mixed with epoxy resin E51 to prepare a self-repairing coating, which was then coated on a Q235 carbon steel plate.

[0063] The specific operating steps and parameters are as follows: 9-13 parts of the curing agent diethylenetriamine are mixed with 100 parts of epoxy E51, followed by vacuum filtration and degassing, and then the two-component self-healing microcapsule material obtained in this embodiment is added. The mixture is then cured at room temperature for 24 hours to obtain an epoxy resin coating doped with the two-component self-healing microcapsule material. The weight ratio of the two-component self-healing microcapsule material to the epoxy resin is 15:100.

[0064] In a comparative experiment, the polyurethane-isophorone diisocyanate microcapsules obtained in Step 1 were mixed with epoxy resin E51 to prepare a self-healing coating, which was then applied to a Q235 carbon steel plate. The specific operating steps and parameters were the same as those for the two-component self-healing microcapsule material.

[0065] In this embodiment, the obtained epoxy resin coating doped with the two-component self-healing microcapsule material and the epoxy resin coating doped with the polyurethane-isophorone diisocyanate microcapsule were scratched on the carbon steel substrate with a scalpel. After 10 seconds, the entire coating was soaked and cleaned with ethyl acetate. After drying, it was immersed in 10% NaCl salt water for 24 hours to observe the corrosion condition.

[0066] like Figure 11 As shown, the results show that the carbon steel plate doped with the two-component self-healing microcapsule material (b) did not corrode, while the control sample doped with phenolic / polyurethane-isophorone diisocyanate microcapsules (a) was severely corroded.

[0067] The results show that the carbon steel plate doped with the dual-component self-repairing microcapsule material did not corrode. The samples were analyzed by electron microscopy. Figure 9 and Figure 10 As shown, polymer is present at the scratches in the epoxy coating doped with the two-component self-healing microcapsule material, and the polymer repairs and closes the crack surface. This is because the scratch destroys the two-component self-healing microcapsule material, simultaneously releasing components A and B to the crack surface. These two components are highly reactive and crosslink rapidly, reacting within seconds to form a polyurethane polymer that is insoluble in ethyl acetate. Therefore, it can continue to protect the steel plate from corrosion even after immersion in salt water. In contrast, the comparison sample doped with polyurethane-isophorone diisocyanate microcapsules releases only isophorone diisocyanate to the crack surface, which is unable to react. After immersion in ethyl acetate, it dissolves, resulting in no polymer formation on the crack surface. This leaves crack grooves, which cannot isolate the steel plate from salt water, leading to corrosion and rust. This demonstrates that the two-component self-healing microcapsule material can achieve rapid crack repair within seconds and has excellent corrosion protection.

[0068] In this embodiment, other existing resin materials can be used to replace epoxy E51 to prepare different coating materials with self-repairing functions. Example 4

[0069] The present invention discloses a method for preparing a two-component self-repairing microcapsule material, which is the same as Example 1, except that:

[0070] In step 1, the mass ratio of deionized water to gum arabic was 100:8, the stirring speed was 400 r / min, and the stirring time was 5 hours. The mass ratio of the oil phase I to the aqueous phase I was 1:5. The emulsification stirring speed was 600 r / min, and the emulsification time was 40 minutes. The ratio of the added 1,4-butanediol to isophorone diisocyanate was 25:100, and the system reaction time was 2 hours.

[0071] In step 2, the mass ratio of polyurethane-isophorone diisocyanate microcapsules to dimethyl silicone oil is 5:100, and the mass ratio of polyurethane-isophorone diisocyanate microcapsules to phenolic resin is 1:2. The mass ratio of dimethyl silicone oil to nano-silica is 100:4. The high-speed stirring speed is 20,000 r / min, and the stirring time is 1 minute. The reaction stirring speed is 700 r / min, and the reaction time is 12 hours.

[0072] In step 3, the ratio of deionized water to amine curing agent was 15%. The mass ratio of aqueous phase II to oil phase II was 1:4. The emulsification stirring speed was 800 r / min, and the emulsification time was 10 minutes. The mass ratio of component A repair agent microcapsules to the emulsion was 30:100. The mass ratio of dimethyl silicone oil to hydrophobic nanosilica was 100:4. The high-speed stirring speed was 20,000 r / min, and the stirring time was 1 minute. The mass ratio of the mixture to dimethyl silicone oil was 10:100. The reaction stirring speed was 600 r / min, and the reaction time was 24 hours.

[0073] Any matters not described in detail in this specification are prior art known to those skilled in the art. Although the above description of the present invention is based on specific embodiments to facilitate understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the specific embodiments. As long as various modifications are within the spirit and scope of the present invention as defined and determined by the appended claims, such modifications will be obvious to those skilled in the art, and all inventions and creations utilizing the concepts of the present invention are protected.

Claims

1. A method for preparing a two-component self-repairing microcapsule material, characterized by: The following steps are involved: Step 1: Deionized water and gum arabic are stirred at room temperature to form an aqueous phase I; a toluene diisocyanate prepolymer L-75, isophorone diisocyanate, and ethyl acetate are mixed to form a uniform oil phase I; the oil phase I is then added to the aqueous phase I and emulsified and stirred to form an oil-in-water emulsion; 1,4-butanediol is dropwise added and stirred at 50° C. to react; and polyurethane-isophorone diisocyanate microcapsules are obtained by filtering, washing, and drying. Step 2: Mixing an alcohol-soluble phenolic resin, anhydrous ethanol, and an NL curing agent to form a solution; adding polyurethane-isophorone diisocyanate microcapsules to the solution formed by mixing the alcohol-soluble phenolic resin, anhydrous ethanol, and the NL curing agent to form a solid-liquid mixture I; mixing dimethyl silicone oil and hydrophobic nano-silica with a high-speed shearing machine to form a continuous phase I; adding the solid-liquid mixture I dropwise to the continuous phase at room temperature, stirring and reacting, and filtering, washing, and drying to obtain the phenolic / polyurethane-isophorone diisocyanate microcapsules of component A; Step 3: Dissolve the polyamine in deionized water to prepare the curing agent of component B, that is, form aqueous phase II; after mixing the epoxy resin and ethylenediamine, add nano-silica and stir evenly to form oil phase II; add aqueous phase II to oil phase II and emulsify and stir to form an emulsion; add nano-silica to dimethyl silicone oil and dissolve it in continuous phase II by high-speed stirring; then add phenolic / polyurethane-isophorone diisocyanate microcapsules to the emulsion to form mixture II; add mixture II dropwise to continuous phase II at room temperature and stir to react, and obtain a two-component self-healing microcapsule material after filtering, washing and drying.

2. The method for preparing a two-component self-repairing microcapsule material according to claim 1, characterized in that: In the step 1, the mass ratio of deionized water to gum arabic is 100:4 to 100:8; in the step 1, the mass ratio of the prepolymer L-75 of isophorone diisocyanate and toluene diisocyanate to ethyl acetate is 4:1:1; in the step 1, the mass ratio of the oil phase I to the water phase I is 1:3 to 1:5; and in the step 1, the mass ratio of 1,4-butanediol to isophorone diisocyanate is 15:100 to 25:

100.

3. The method for preparing a two-component self-repairing microcapsule material according to claim 1, characterized in that: The stirring speed for forming aqueous phase I in step 1 is 400-800 r / min, and the stirring time is 3-5 hours; the emulsification stirring speed for forming an oil-in-water emulsion in step 1 is 600-1000 r / min, and the emulsification time is 20-40 minutes; the reaction time for stirring the reaction at 50° C. after adding 1,4-butanediol in step 1 is 1-3 hours.

4. The method for preparing a two-component self-repairing microcapsule material according to claim 1, characterized in that: In the step 2, the mass ratio of the phenolic resin, anhydrous ethanol and NL curing agent is 100:200:15; in the step 2, the mass ratio of the polyurethane-isophorone diisocyanate microcapsules to the dimethyl silicone oil is 1:100-5:100; in the step 2, the mass ratio of the polyurethane-isophorone diisocyanate microcapsules to the phenolic resin is 2:1-1:2; in the step 2, the mass ratio of the dimethyl silicone oil to the nano-silica is 100:2-100:

4.

5. The method for preparing a two-component self-repairing microcapsule material according to claim 1, characterized in that: In step 2, the high-speed shearing machine is used to mix and stir uniformly to form a continuous phase I, and the stirring speed is 10,000 to 20,000 r / min, and the stirring time is 1 to 3 minutes; in step 2, the solid-liquid mixture I is added dropwise to the continuous phase I and the stirring reaction is carried out at a stirring speed of 400 to 700 r / min, and the reaction time is 6 to 12 hours.

6. The method for preparing a two-component self-repairing microcapsule material according to claim 1, characterized in that: The mass ratio of deionized water to curing agent in step 3 is 5 to 50:100; the mass ratio of epoxy resin, ethylenediamine, and nano-silica in step 3 is 100:10:4; the mass ratio of aqueous phase II to oil phase II in step 3 is 1:6 to 1:1; the mass ratio of phenolic / polyurethane-isophorone diisocyanate microcapsules to emulsion in step 3 is 5:100 to 30:100; the mass ratio of dimethyl silicone oil to nano-silica in step 3 is 100:2 to 100:4; and the mass ratio of mixture II to dimethyl silicone oil in step 3 is 1:100 to 15:

100.

7. The method for preparing a two-component self-repairing microcapsule material according to claim 1, characterized in that: The stirring speed of the emulsification and stirring to form an emulsion in step 3 is 400~800r / min, and the emulsification time is 10~30min; the stirring speed of the high-speed stirring and dissolving to form a continuous phase II in step 3 is 10000~20000r / min, and the stirring time is 1~3min; the stirring speed of adding the mixture II dropwise to the continuous phase II in step 3 and stirring the reaction is 150~600r / min, and the reaction time is 6~24h.

8. A two-component self-repairing microcapsule material prepared by the preparation method according to claim 1, characterized in that: The two-component self-repairing microcapsule material includes a primary microcapsule core material and a primary wall material coated on the primary microcapsule core material; The primary microcapsule core material is composed of component A of the repair agent microcapsule and component B of the curing agent, wherein the component A of the repair agent microcapsule includes a secondary core material and a secondary wall material coated outside the secondary core material; The primary wall material is epoxy resin; the repair agent microcapsules of component A are phenolic / polyurethane-isophorone diisocyanate microcapsules; and the curing agent of component B is polyamine.

9. A two-component self-repairing microcapsule material prepared by the preparation method according to claim 1, characterized in that: The secondary wall material of the repair agent microcapsule of component A is phenolic / polyurethane resin, and the secondary core material is isophorone diisocyanate.

10. A two-component self-repairing microcapsule material prepared by the preparation method according to claim 1, characterized in that: The particle size of the self-repairing microcapsule material is 40 to 2000 microns, and the thickness of the primary wall material is 3 to 70 microns.

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