A method for preparing a solvent-free tank bottom patching agent

Abstract

The application discloses a preparation method of a solvent-free tank bottom plate repairing agent. The method is combined with pre-polymerization and mechanical blending, a small amount of resin is polymerized with a curing agent to form a small amount of reticular polymerization structure, and then the reticular polymerization structure is mixed with functional fillers, and the reticular polymerization structure is mixed with resin components and solidified uniformly during use. The coating prepared by the method has high polymerization degree and large product molecular weight, and has better adhesion effect on a substrate, higher strength, excellent flexibility and corrosion resistance compared with traditional anticorrosive coatings.

Description

Technical Field

[0001] This invention belongs to the field of chemical raw materials and chemical products manufacturing, specifically relating to a solvent-free tank bottom plate repair agent and its preparation method. Background Technology

[0002] The bottom of petrochemical storage tanks is highly susceptible to electrochemical corrosion caused by chloride ions, hydrogen sulfide, carbon dioxide, and oxygen, as well as bacterial corrosion caused by sulfate-reducing bacteria, due to the presence of a water layer. This type of corrosion, acting on the tank bottom over a long period, forms numerous pits and can even cause perforation, jeopardizing storage and transportation safety and resulting in material waste. Traditional repair methods after corrosion occurs include metal welding and reinforcing with steel plates, but these methods require open flames or the use of large areas of carbon steel plates, significantly impacting production. Epoxy zinc-rich conductive coating technology, used as an anti-corrosion and anti-static coating for the inner wall of storage tanks, is also applied to tank bottom repair; however, traditional epoxy resin coating materials have limited protection against acidic and alkaline media and cannot achieve long-term, high-efficiency protection. In the early stages, Wang Feng et al. prepared a tank bottom repair agent using epoxy resin as a binder, phenoxypropylene oxide as a plasticizer, and polyethylene polyamine as a curing agent at a weight ratio of 100:10:(10-12). They employed a one-step curing method for cross-linking and used two coating methods—applying a patching method and a lamination method—to repair different corroded areas of the tank bottom. However, apart from this, mature materials and technologies for repairing the bottom of steel storage tanks have not yet been developed.

[0003] Therefore, in order to improve repair efficiency and effectively extend the service life of storage tanks, it is necessary to develop a high-efficiency corrosion-resistant tank bottom repair agent. Based on preliminary research and on-site tank area exchanges, it is considered to use epoxy resin as the matrix, compound with different functional fillers, and small molecule amines as curing agents, without adding dispersants, defoamers and other organic solvents, to prepare a solvent-free epoxy repair material. Summary of the Invention

[0004] The purpose of this invention is to provide a solvent-free tank bottom plate repair agent and its preparation method, so as to solve the problem that the existing technology cannot simultaneously take into account environmental protection and achieve efficient repair and protection of the tank bottom.

[0005] According to a first aspect of the present invention, the present invention provides a method for preparing a solvent-free tank bottom plate repair agent.

[0006] Specifically, the preparation method of the solvent-free tank bottom plate repair agent of the present invention includes the following:

[0007] (1) Epoxy resin is uniformly dispersed in an organic solvent to obtain an epoxy resin slurry;

[0008] (2) Add small molecule amine to the reactor and purge with nitrogen for protection; turn on mechanical stirring and heat the small molecule amine to the pre-crosslinking reaction temperature; after the temperature stabilizes, slowly add the resin slurry obtained in step (1) to the reactor until the color of the reaction solution turns light yellow and the color no longer changes.

[0009] (3) Raise the reactor temperature to the reaction temperature and continue to slowly add the epoxy resin slurry obtained in step (1) into the reactor. After the temperature stabilizes, continue the reaction until the end.

[0010] (4) After the reaction is complete, stop heating, turn off nitrogen, stop stirring, cool to room temperature and discharge to obtain repair agent component A;

[0011] (5) Mix epoxy resin, lubricant, inorganic filler and optional organic filler evenly to obtain repair agent component B.

[0012] Furthermore, in the above technical solution, the organic solvent mentioned in step (1) includes one or more of ethanol, methanol, and acetone, preferably acetone. The epoxy resin is a conventional epoxy resin in the art, specifically selected from one or more of epoxy resins E44, E51, 170, E12, E20, and E68.

[0013] Furthermore, in the above technical solution, the small molecule amines in step (2) include one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, N-aminopiperazine, polyamide, and dimethylimidazole, preferably two or more, and most preferably three or more small molecule amines used in combination.

[0014] Furthermore, in the above technical solution, step (2) involves slowly adding the resin slurry to the small molecule amine, which is a conventional operation in the field.

[0015] Furthermore, in the above technical solution, the pre-crosslinking temperature of the small molecule amine in step (2) is 80±10 ℃. When the color of the reaction solution changes during the reaction process, it indicates that new substances are generated, and the addition of resin slurry should be stopped at this time. During the pre-crosslinking reaction, the mass ratio of the amount of resin slurry added (based on epoxy groups) to the mass of the small molecule amine is 1:10-1:5.

[0016] Furthermore, in the above technical solution, the reaction temperature in step (3) is 100±10 ℃, and the reaction time is 3.5±1 h. During the reaction, the total amount of resin slurry added, calculated as epoxy groups, is in a mass ratio of 1:10 to 8:10 to the mass of small molecule amine.

[0017] Furthermore, in the above technical solution, the epoxy resin serves as the repair agent matrix, providing the repair agent with certain strength and toughness. The lubricant is selected from one or more of alkane oil and dimethyl silicone oil (AR). The alkane oil can be selected from one or more of C6, C10, and C12. The alkane oil acts as a lubricant, improving the compatibility between the filler and the resin, and making its dispersion more uniform. The inorganic filler includes one or more of ferrosilicon powder, carbon black, calcium carbonate (AR), silicon dioxide (AR), and titanium dioxide (AR). The ferrosilicon powder can be selected from one or more of 75#, 70#, 72#, 65#, and 60#. The carbon black can be selected from one or more of C311, N220, N330, and N550. The inorganic filler is used to fill the voids between resins, giving the repair agent certain rigidity and strength, while improving adhesion to the substrate. Preferably, two or more of the inorganic fillers are used in a compound ratio. The organic filler can be organobentonite (AR). Organic fillers have an anti-settling effect and can also improve the corrosion resistance of the system.

[0018] Furthermore, the epoxy resin used in step (5) is selected from one or more of epoxy E44, E51, 170, E12, E20, and E68, with epoxy E44 being preferred. Preferably, the epoxy resin used in step (5) and step (1) is the same brand. The ratio of epoxy resin, lubricant, inorganic filler, and optional organic filler is 100:1.6-1.7:141.6-233.9:5-10. When the repair agent of the present invention is applied, the mixing ratio of repair agent component A and repair agent component B is generally 3.1:1-6.5:1.

[0019] Based on research findings, the applicant discovered that epoxy resin is widely used in functional protective coatings for storage tank surfaces. However, there is currently no good solution for repairing corrosion at the bottom of storage tanks. Current methods mostly involve replacing the bottom plate or adding reinforcing plates, which are costly, wasteful of resources, and require hot work, posing a significant risk. Drawing on experience in external corrosion protection of storage tanks, the applicant proposes coating the damaged area at the bottom of the tank with a solvent-free metal repair material. After curing, the material forms a high-strength, high-hardness paint film that can replace the metal steel plate for continued service. This method is simple to operate, energy-saving, and the solvent-free system is also more environmentally friendly.

[0020] Previous experiments revealed that directly blending epoxy resin and curing agent leads to incomplete cross-linking reactions between resin molecules, resulting in decreased adhesion of the paint film to the metal, as well as reduced rigidity and flexibility. This allows corrosive media to penetrate the paint film and further corrode the substrate. Therefore, this invention develops a step-by-step curing method to improve the internal curing rate of the resin, forming a highly cross-linked and dense paint film that adheres tightly to the metal surface. This provides rigid support while hindering the penetration of corrosive media, extending the service life of the storage tank and reducing operating costs.

[0021] In this invention, a combination of multiple small-molecule amine curing agents is preferred. This is because, compared to polyamide, piperazine, and imidazole curing agents, small-molecule curing agents have shorter molecular chains, better molecular flexibility, less steric hindrance during the resin curing reaction, and greater flexibility. The combination of multiple small-molecule amine curing agents provides a more precise molar amount of active amines, and the synergistic effect between molecules promotes full cross-linking between resin molecules and the curing agent.

[0022] Adding functional pigments and fillers such as carbon black, ferrosilicon powder, calcium carbonate, organobentonite, silica, and titanium dioxide to the paint film system can fill the tiny gaps in the resin, preventing corrosive substances from penetrating the paint film and corroding the substrate. At the same time, ferrosilicon powder and other substances have a certain affinity for the substrate, which helps the adhesion of the paint film.

[0023] In summary, epoxy resin and curing agent can be pre-cured by prepolymerization, and functional pigments and fillers can be added to the obtained slurry to prepare a metallic repair material with high adhesion, heavy corrosion resistance, and high strength and modulus.

[0024] Compared to traditional methods, the coating prepared by this method innovatively employs a stepwise polymerization approach. First, the curing agent is cross-linked and cured with a small amount of resin, and then the remaining resin is added to achieve complete curing. This method significantly improves the resin curing rate in the paint film, resulting in a highly corrosion-resistant and highly adhesive coating. The addition of fillers also contributes to the rigidity repair and corrosion resistance of the paint film, and the solvent-free nature aligns better with the concept of green environmental protection.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. By employing a stepwise polymerization method for the resin, the contact density between resin and curing agent molecules is controlled. In the prepolymerization stage, a small number of resin molecules bond with the curing agent, forming a small cross-linked network. When components A and B are mixed, the resin molecules react with the remaining active amine, connecting the various small cross-linked networks into a whole. This significantly increases the degree of polymerization between the resin and the curing agent, resulting in a uniform and dense network structure. This improves the cross-linking density of the repair agent, thereby enhancing its overall mechanical properties. It combines high strength and high flexibility while resisting the penetration of corrosive media, giving it a certain degree of corrosion resistance. In contrast, in one-step cross-linking polymerization, a large amount of resin and curing agent come into contact simultaneously, producing a large number of small cross-linked networks. Compared to stepwise cross-linking, the density is poor, leading to lower mechanical strength and corrosion resistance.

[0027] 2. The repair agent is formulated using a combination of pre-polymerization and mechanical blending. First, a small amount of resin and curing agent mixture is polymerized to form a small network polymer structure. This is then mixed with functional fillers, and the mixture is thoroughly mixed with the resin components before use and cured. The coating prepared using this method has a high degree of polymerization and a large molecular weight, resulting in better adhesion to the substrate and higher strength compared to traditional anti-corrosion coatings. It also possesses excellent flexibility, allowing it to withstand significant pressure changes when used for tank bottom plate repair. It has a long service life, requires no repeated application, and is suitable for various working conditions. Furthermore, the system does not contain any organic solvents, resulting in no VOC emissions during use, making it environmentally friendly and more eco-friendly. A highly corrosion-resistant resin is selected as the repair agent matrix, improving both the flexibility and mechanical strength of the repair agent while maintaining its anti-corrosion properties.

[0028] 3. The repair agent provided by this invention incorporates various functional pigments and fillers such as ferrosilicon powder, carbon black, and alkane oil into the coating. These filler elements fill resin voids, improving the adhesion of the repair agent to the metal substrate and hindering the penetration of corrosive media. The resin, curing agent, and fillers mutually promote each other, forming a unified whole. This ensures coating adhesion while imparting certain anti-corrosion and anti-aging properties to the coating. Furthermore, ferrosilicon powder and other components have a certain affinity for the substrate, contributing to improved adhesion between the repair agent and the substrate.

[0029] 4. The repair agent system prepared by the method of the present invention is a solvent-free system. No organic solvent is added during use or application. The small amount of diluent added during the reaction process is recovered and reused after dissipating and evaporating in the reaction, which is harmless to the environment and more green and environmentally friendly. Detailed Implementation

[0030] The present invention will now be described in more detail with reference to specific embodiments.

[0031] Adhesion test: The adhesion of the coating film was tested according to the requirements of GB / T 5210-2006 "Paints and Varnishes - Pull-off Adhesion Test".

[0032] Pencil hardness determination: The test was conducted according to standard GB / T 6379-2006, "Determination of Hardness of Paints and Varnishes by Pencil Method". A coat (25±5 μm) was sprayed onto a tinplate measuring 120 mm × 50 mm × 0.3 mm. After curing for 7 days, a pencil hardness tester was pushed across the paint film. The number of scratches produced on the paint film surface when a pencil of specified hardness was pushed across it was compared. The hardness of the coating was expressed as the hardness of the hardest pencil that produced no defects in the paint film.

[0033] Bending resistance test: Tested according to standard GB / T 6742-2007 "Bending Test of Paints and Varnishes (Cylindrical Shaft)". A single coat (25±5 μm) is sprayed onto a tinplate with dimensions of 120 mm × 50 mm × 0.3 mm. After curing for 48 hours, a bending test is performed on a Type II bending tester, and the presence of cracking, peeling, or other phenomena is observed. The bending resistance of the coating is expressed as the maximum shaft diameter (mm) that causes cracking or peeling.

[0034] Impact resistance test: Tested according to standard GB / T 1732-1993 "Determination of Impact Resistance of Coating Film". A layer (25±5 μm) is sprayed onto a 120mm×50mm×0.3mm tinplate. After curing for 48 hours, the test plate is placed on an impact tester, and a weight is dropped freely from a certain height. The presence of cracks or other defects is observed. The impact resistance of the coating is expressed as the maximum height (cm) from which a weight of specified mass can fall onto the test plate without causing damage to the coating film.

[0035] Water resistance test: The test was conducted according to standard GB 1733-1993 "Determination of Water Resistance of Paint Film". A layer (25±5 μm) was sprayed onto a tinplate with dimensions of 120mm×50mm×0.3mm and cured for 7 days. Before the test, the edges were sealed with a 1:1 mixture of paraffin and rosin. The test panel was then immersed in distilled water for at least 48 hours. After reaching the end of the immersion period, the test panel was thoroughly rinsed with distilled water, and the changes in the coating were checked.

[0036] Acid and alkali resistance test: The test was conducted according to standard GB 9274-1988 "Determination of resistance to liquid media for paints and varnishes". One coat of primer and two coats of topcoat (90±10 μm) were applied to a steel plate with dimensions of 150 mm × 70 mm × 0.5 mm. The plate was coated on both sides and cured for 7 days. Before testing, the edges were sealed with a 1:1 mixture of paraffin and rosin. Then, the plate was immersed in a prepared solution of 5% sulfuric acid and 5% sodium hydroxide for at least 168 hours. After the immersion period, the plate was thoroughly rinsed with distilled water, and the changes in the coating were observed and recorded at the time of occurrence.

[0037] The resins, curing agents, lubricants, and solid fillers used in the examples and comparative examples are all commercially available products. Example 1

[0038] Add 2g of diethylenetriamine, 4.6g of triethylenetetramine, and 4.5g of tetraethylenepentamine to the reactor, and purge with nitrogen to prevent the small molecule amines from absorbing water and generating fumes. Disperse 10g of epoxy resin E44 in 10g of acetone, then place it in a dripping tube to clean the residual resin and pour the cleaning solution into the dripping tube. Pour in cooling water, turn on the mechanical stirrer, and heat the reactor to 90℃. After the temperature stabilizes, turn on the dripping tube and add resin dropwise to the reactor, controlling the dropwise addition time to 40min. After the dropwise addition is complete, clean the dripping tube and raise the reactor temperature to 110℃. Continue the reaction for 4.5h, then discharge to obtain repair agent component A.

[0039] Mix 93g of epoxy resin E44, 1.5g of alkane oil (C12), 199.5g of ferrosilicon powder (75#), and 3.3g of carbon black (C311) evenly to obtain repair agent component B.

[0040] Repair agent component A and repair agent component B were mixed evenly at a ratio of 3.5:1 and allowed to mature for about 5 minutes before being applied as a film. The sample was then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test its physical and anti-corrosion properties. Example 2

[0041] Add 2g of diethylenetriamine, 6.6g of triethylenetetramine, and 2.5g of tetraethylenepentamine to the reactor, and purge with nitrogen to prevent the small molecule amines from absorbing water and generating fumes. Disperse 10g of epoxy resin E44 in 10g of acetone, then place it in a dripping tube to clean off any residual resin, pouring the cleaning solution into the dripping tube. Pour in cooling water, turn on the mechanical stirrer, and heat the reactor to 70℃. After the temperature stabilizes, turn on the dripping tube and add resin dropwise to the reactor, controlling the dropwise addition time at 45 minutes. After the dropwise addition is complete, clean the dripping tube and raise the reactor temperature to 90℃. Continue the reaction for 2.5 hours, then discharge to obtain repair agent component A.

[0042] Mix 93g of epoxy resin E44, 1.5g of alkane oil (C10), 199.5g of ferrosilicon powder (75#), 3.3g of carbon black (C311), and 6.5g of organobentonite (AR) evenly to obtain repair agent component B.

[0043] Repair agent component A and repair agent component B were mixed evenly at a ratio of 3.5:1 and allowed to mature for about 5 minutes before being applied as a film. The sample was then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test its physical and anti-corrosion properties. Example 3

[0044] Add 7.6g of diethylenetriamine and 3.5g of tetraethylenepentamine to the reactor, and purge with nitrogen to prevent the small molecule amines from absorbing water and generating fumes. Disperse 10g of epoxy resin E44 in 10g of acetone, then place it in a dripping tube to clean the residual resin and pour the cleaning solution into the dripping tube. Pour in cooling water, turn on the mechanical stirrer, and heat the reactor to 90℃. After the temperature stabilizes, turn on the dripping tube and add resin dropwise to the reactor, controlling the dropwise addition time to 40min. After the dropwise addition is complete, clean the dripping tube and raise the reactor temperature to 110℃. Continue the reaction for 4.5h, then discharge to obtain repair agent component A.

[0045] Mix 93g of epoxy resin E44, 1.5g of alkane oil (C12), 199.5g of ferrosilicon powder (75#), and 3.3g of carbon black (C311) evenly to obtain repair agent component B.

[0046] Repair agent component A and repair agent component B were mixed evenly at a ratio of 3.5:1 and allowed to mature for about 5 minutes before being applied as a film. The sample was then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test its physical and anti-corrosion properties. Example 4

[0047] Add 3.6g of diethylenetriamine, 2g of triethylenetetramine, and 5.5g of tetraethylenepentamine to the reactor, and purge with nitrogen to prevent the small molecule amines from absorbing water and generating fumes. Disperse 10g of epoxy resin E44 in 20g of acetone, then place it in a dripping tube to clean the residual resin and pour the cleaning solution into the dripping tube. Pour in cooling water, turn on the mechanical stirrer, and heat the reactor to 80℃. After the temperature stabilizes, turn on the dripping tube and add resin dropwise to the reactor, controlling the dropwise addition time to 50min. After the dropwise addition is complete, clean the dripping tube and raise the reactor temperature to 90℃. Continue the reaction for 3.5h, then discharge to obtain repair agent component A.

[0048] Mix 93g of epoxy resin E44, 1.5g of alkane oil (C12), 127.5g of ferrosilicon powder (70#), and 3.3g of carbon black (C311) evenly to obtain repair agent component B.

[0049] Repair agent component A and repair agent component B were mixed evenly at a ratio of 3.5:1 and allowed to mature for about 5 minutes before being applied as a film. The sample was then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test its physical and anti-corrosion properties. Example 5

[0050] Add 2.1g of diethylenetriamine, 2g of triethylenetetraamine, and 7g of tetraethylenepentamine to the reactor. Purge with nitrogen to prevent the small-molecule amines from absorbing water and generating fumes. Disperse 15g of epoxy resin E44 in 10g of acetone, then place the solution in a dripping tube to clean off any residual resin. Pour the cleaning solution into the dripping tube. Pour in cooling water, turn on the mechanical stirrer, and heat the reactor to 90℃. Once the temperature stabilizes, turn on the dripping tube and add resin dropwise to the reactor over a period of 55 minutes. After the addition is complete, clean the dripping tube and raise the reactor temperature to 100℃. Continue the reaction for 4.5 hours, then discharge to obtain repair agent component A.

[0051] Mix 88g of epoxy resin E44, 1.5g of alkane oil (C12), 199.5g of ferrosilicon powder (75#), and 6.3g of carbon black (C311) evenly to obtain repair agent component B.

[0052] Repair agent component A and repair agent component B were mixed evenly at a ratio of 3.5:1 and allowed to mature for about 5 minutes before being applied as a film. The sample was then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test its physical and anti-corrosion properties. Example 6

[0053] Add 11.1g of triethylenetetramine to the reactor and purge with nitrogen to prevent the small molecule amine from absorbing water and generating fumes. Disperse 10g of epoxy resin E44 in 10g of acetone, then place it in a dripping tube to clean the residual resin and pour the cleaning solution into the dripping tube. Pour in cooling water, turn on the mechanical stirrer, and heat the reactor to 90℃. After the temperature stabilizes, turn on the dripping tube and add resin dropwise to the reactor, controlling the dropwise addition time to 40min. After the dropwise addition is complete, clean the dripping tube and raise the reactor temperature to 110℃. Continue the reaction for 4.5h before discharging to obtain repair agent component A.

[0054] Mix 93g of epoxy resin E44, 1.5g of alkane oil (C12), 199.5g of ferrosilicon powder (75#), and 3.3g of carbon black (C311) evenly to obtain repair agent component B.

[0055] Repair agent component A and repair agent component B were mixed evenly at a ratio of 3.5:1 and allowed to mature for about 5 minutes before being applied as a film. The sample was then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test its physical and anti-corrosion properties.

[0056] Comparative Example 1

[0057] Take 103g of epoxy resin E44, 2g of diethylenetriamine, 4.6g of triethylenetetramine, 4.5g of tetraethylenepentamine, 1.5g of alkane oil (C12), 199.5g of ferrosilicon powder (75#), and 3.3g of carbon black (C311), mix them evenly, cure for about 5 minutes, and then coat them into a film.

[0058] The samples were then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test their physical and anti-corrosion properties.

[0059] Comparative Example 2

[0060] Add 2g of diethylenetriamine, 4.6g of triethylenetetramine, and 4.5g of tetraethylenepentamine to the reactor, and purge with nitrogen to prevent the small molecule amines from absorbing water and generating fumes. Disperse 3g of epoxy resin E44 in 10g of acetone, then place it in a dripping tube to clean the residual resin and pour the cleaning solution into the dripping tube. Pour in cooling water, turn on the mechanical stirrer, and heat the reactor to 90℃. After the temperature stabilizes, turn on the dripping tube and add resin dropwise to the reactor, controlling the dropwise addition time to 40min. After the dropwise addition is complete, clean the dripping tube and raise the reactor temperature to 110℃. Continue the reaction for 4.5h, then discharge to obtain repair agent component A.

[0061] Mix 100g of epoxy resin E44, 1.5g of alkane oil (C12), 199.5g of ferrosilicon powder (75#), and 3.3g of carbon black (C311) evenly to obtain repair agent component B.

[0062] Mix repair agent component A and repair agent component B in a ratio of 3.5:1 until homogeneous, allow to mature for about 5 minutes, and then apply as a film.

[0063] The samples were then placed in a constant temperature and humidity chamber at 25 ℃ and 50% humidity for 7 days to test their physical and anti-corrosion properties.

[0064] Table 1

[0065] sample Adhesion (MPa) Pencil hardness Bending strength (mm) Impact strength (cm) Water resistance (h) Acid resistance (h) Alkali resistance (h) Example 1 5.21 2H 2 50 48 168 168 Example 2 4.85 H 2 50 48 160 168 Example 3 4.52 H 2 50 40 124 168 Example 4 6.70 2H 2 50 48 168 168 Example 5 10.46 3H 2 50 48 168 168 Example 6 4.10 H 2 50 48 168 144 Comparative Example 1 2.84 H 2 50 48 168 100 Comparative Example 2 4.58 2H 2 50 48 168 168

Claims

1. A process for the preparation of a solventless tank bottom repair agent, characterized in that, The method comprises the following steps: (1) uniformly dispersing epoxy resin in an organic solvent to obtain an epoxy resin slurry; (2) adding a small molecule amine into a reactor while introducing nitrogen protection; opening mechanical stirring, heating the small molecule amine to a pre-crosslinking reaction temperature; after the temperature is stabilized, slowly adding the resin slurry obtained in step (1) into the reactor until the color of the reaction solution becomes light yellow and the color no longer changes; (3) increasing the temperature of the reactor to a reaction temperature, continuing to slowly add the resin slurry obtained in step (1) into the reactor, after the temperature is stabilized, continuing to react until the reaction is completed; (4) after the reaction is completed, stopping heating, closing the nitrogen, stopping stirring, cooling to room temperature to discharge, to obtain a repair agent component A; (5) uniformly mixing epoxy resin, a lubricant, an inorganic filler and an optional organic filler to obtain a repair agent component B; (6) mixing the repair agent component A and the repair agent component B according to a ratio of 3.1:1-6.5:1 to obtain a repair agent; wherein the pre-crosslinking reaction temperature is 80±10 ℃, and the reaction temperature is 100±10 ℃; In step (2), the mass ratio of the total addition amount of the resin slurry calculated based on epoxy groups to the small molecule amine is 1:10-8:

10. The organic solvent comprises one or more of ethanol, methanol and acetone.

2. The production method according to claim 1, characterized by, The organic solvent is selected from acetone.

3. The preparation method according to claim 2, characterized in that, The small molecule amine comprises one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, N-aminopiperazine and dimethylimidazole.

4. The production method according to claim 1, characterized by, The small molecule amine comprises two or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, N-aminopiperazine and dimethylimidazole.

5. The preparation method according to claim 4, characterized in that, The reaction time in step (3) is 3.5±1 h.

6. The production method according to claim 1, characterized by, The lubricant is selected from one or more of alkane oil and dimethyl silicone oil; the inorganic filler comprises one or more of ferrosilicon powder, carbon black, calcium carbonate, silicon dioxide and titanium dioxide.

7. The production method according to claim 1, characterized by, The organic filler is organic bentonite.

8. The production method according to claim 1 or 7, characterized by, 9. A solvent-free tank bottom plate repair agent prepared by the method of any one of claims 1-8. ​