Metal surface wet adhesion patching material, preparation method and application

Abstract

The application discloses a metal surface wet adhesion plugging material, a preparation method and application, the plugging material includes modified epoxy mixture 36-40 parts, curing agent 30-50 parts, adhesion promoter 0.5-5 parts, wherein the modified epoxy mixture is composed of polyphenol modified epoxy compound and bisphenol A type epoxy resin, the modified epoxy compound is synthesized by polyphenol and glycidyl ether reaction; the adhesion promoter is a silane modified nanoparticle, and the curing agent includes a polyamine type curing agent, a polythiol curing agent and a curing accelerator. The polyphenol material with high wet adhesion is introduced into the epoxy network structure in a covalent manner through a chemical grafting method, excellent wet adhesion performance is given to the plugging material, the plugging material can be quickly cured in a humid and underwater environment, has good toughness, and can be used for plugging and surface corrosion prevention and reinforcement of a metal storage and transportation structure leak in a high-humidity and underwater environment.

Description

Technical Field

[0001] This invention belongs to the field of sealing material technology, specifically relating to a metal surface wet-adhesion sealing material, its preparation method, and its application. Background Technology

[0002] Metal pressure pipelines serve multiple functions, including transportation, distribution, mixing, and control, and are widely used in energy, chemical, construction engineering, water conservancy and hydropower, and high-end equipment industries. During service, pipelines are subjected to the combined effects of external corrosive environments, internal pressure, and material stress, leading to damage such as micropores and microcracks. This can cause leaks, affecting the normal operation of pipelines and related equipment, resulting in serious safety hazards and economic losses. Therefore, timely repair of pipeline damage and the development of efficient leak-sealing materials are crucial for ensuring the safe operation of pipelines.

[0003] CN1070669A discloses an external sealing adhesive and sealing method for buried gas pipelines. The adhesive uses epoxy resin as the main component, acetone or glycidyl ether as a diluent, liquid polysulfide rubber as a toughening agent, silica as a filler, quartz powder or cement as component A, KH550 or KH560 as component B, and adds curing agent YH-82 and accelerator DMP-30 to prepare the sealing adhesive. This adhesive can cure at low temperatures (0℃ to -20℃), meeting the needs of emergency leak sealing in northern winters. It allows for pressurized leak sealing without interrupting gas supply, reducing gas emission losses and environmental pollution. The process is simple, easy to operate, and the cost is one-third lower than the splicing method.

[0004] CN105368065A discloses a magnetic leak-sealing adhesive and its preparation method. The magnetic leak-sealing adhesive is composed of 50-70% silicone rubber, 30-50% magnetic powder, 10-30% silicone resin, 30-50% organic solvent, 1-2% comprehensive catalyst, and 1-2% crosslinking agent. The above raw materials are mixed at high speed, kneaded, stopped, sliced, formed into strips, packaged with release paper, and magnetized to obtain the magnetic leak-sealing adhesive. It can be adsorbed around the leak defect or directly onto the working surface of a strong magnetic leak-sealing tool. In particular, the magnetic leak-sealing adhesive directly adsorbed onto the working surface of the strong magnetic leak-sealing tool is not easily blown away or dispersed by the leaking medium. The magnetic leak-sealing adhesive is a viscoelastic material, easily deformable, and can effectively compensate for unevenness at the leak defect location. When used in conjunction with a strong magnetic leak-sealing tool, it can achieve rapid pressurized leak sealing. It is widely used in emergency leak sealing operations for containers, pipelines, tank trucks, and gas cylinders.

[0005] CN108676515A discloses a quick-sealing tape for ship pipelines, comprising a tie layer and an adhesive layer disposed below the tie layer. The base layer is made of fluororubber. A first protective layer and a second protective layer are disposed on the upper and lower sides of the base layer, respectively. A reinforcing layer adapted to it is also disposed on one side of the base layer. The base layer, adhesive layer, first protective layer, second protective layer, and reinforcing layer account for 58-77%, 8-17%, 6-11%, 6-11%, and 7-15% of the weight of the tape body, respectively, by weight percentage. The quick-sealing tape has good flame retardancy, corrosion resistance, wear resistance, and mechanical strength, and can quickly seal leaks at damaged points.

[0006] Currently, polymer-based pipe sealing materials are commonly used for leak sealing. These materials have no special requirements regarding pipeline shape, leak location, or substrate material, making them suitable for repairing various metal pipelines. Furthermore, polymer-based sealing materials are easy to apply, have no impact on the base metal, and avoid localized corrosion and galvanic corrosion at the leak site, allowing for wide application in various materials and complex environments. However, in humid and underwater environments, a water film exists on the surface of metal pipelines. Traditional polymer-based sealing materials experience emulsifier dissolution problems, severely reducing the degree of polymer curing and cross-linking density, damaging the polymer's adhesion to the metal surface, and affecting the sealing effect. In addition, currently used polymer-based sealing materials lack sufficient strength and toughness, and have insufficient impact resistance and crack propagation resistance, making them unable to provide long-term stable sealing for pressure pipeline damage.

[0007] Therefore, there is an urgent need to develop leak-sealing materials with high strength and toughness and excellent wet adhesion properties to achieve efficient repair of leaks in metal pressure pipelines in high humidity and underwater environments. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a wet-adhesion sealing material for metal surfaces, its preparation method, and its applications. A polyphenol-modified epoxy compound is prepared using a chemical grafting method, then mixed with bisphenol A type epoxy resin to form a modified epoxy mixture. This mixture is then combined with a curing agent and an adhesion promoter to prepare the sealing material, which exhibits excellent strength and toughness, meeting the sealing requirements of metal pressure pipelines. It is also suitable for sealing leaks in metal structures in high-humidity or underwater environments.

[0009] To achieve the above objectives, the present invention provides a wet-adhesion sealing material for metal surfaces, the sealing material comprising the following raw materials in parts by weight: 36-40 parts of modified epoxy mixture, 30-50 parts of curing agent, and 0.5-5 parts of adhesion promoter.

[0010] Preferably, the modified epoxy mixture is composed of a polyphenol-modified epoxy compound and a bisphenol A type epoxy resin, wherein the mass ratio of the polyphenol-modified epoxy compound to the bisphenol A type epoxy resin is 5-20:80-95.

[0011] More preferably, the polyphenol-modified epoxy compound is synthesized by reacting polyphenolic substances with glycidyl ether, wherein the polyphenolic substances are any one of gallic acid, levodopa, and caffeic acid; and the glycidyl ether is any one of polypropylene glycol diglycidyl ether, butylene glycol diglycidyl ether, and glycerol triglycidyl ether.

[0012] More preferably, the bisphenol A type epoxy resin is any one of E51, E54, and E20.

[0013] Preferably, the curing agent is composed of a polyamine curing agent, a polythiol curing agent, and a curing accelerator; the amount of the curing accelerator is 1%-5% of the total mass of the curing agent, and the polyamine curing agent and the polythiol curing agent are miscible in any ratio.

[0014] More preferably, the polyamine curing agent is any one of tetraethylenepentamine, isophorone diamine, polyamide 650, and phenolic amine T31; and the curing accelerator is any one of 2,4,6-tris(dimethylaminomethyl)phenol, resorcinol, and benzyl dimethylamine.

[0015] Preferably, the adhesion promoter is silane-modified nanoparticles; the particle size of the nanoparticles is 50-200 nm.

[0016] More preferably, the silane is any one of (3-mercaptopropyl)trimethoxysilane, 3-glycidyl etheroxypropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; and the nanoparticles are any one of iron oxide, zinc oxide, silicon carbide, and metal-organic frameworks.

[0017] More preferably, the metal-organic framework is any one of ZIF7, ZIF8, UIO-66 and copper-tannic acid.

[0018] This invention also provides a method for preparing a wet-adhesion sealing material for metal surfaces, comprising the following steps:

[0019] (1) Dissolve polyphenols and glycidyl ether in a solvent, mix well, add triphenylphosphine, and react at 110-130℃ for 6-8h to obtain polyphenol-modified epoxy compounds.

[0020] (2) The polyphenol-modified epoxy compound was mixed with bisphenol A type epoxy resin to obtain a modified epoxy mixture;

[0021] (3) After mixing and dispersing the nanoparticles with anhydrous ethanol, ammonia water is added, and silane is added while stirring. Stirring is continued for 2-4 hours to obtain an adhesion promoter.

[0022] (4) Mix the polyamine curing agent, polythiol curing agent, and curing accelerator evenly to obtain the curing agent;

[0023] (5) Mix the modified epoxy mixture, curing agent and adhesion promoter evenly, let stand for 5-10 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0024] Preferably, the solvent in step (1) is anhydrous toluene; the mass ratio of the polyphenolic substance to glycidyl ether is 1:5-20.

[0025] Preferably, the mass ratio of silane to nanoparticles in step (3) is 1:1-5.

[0026] The present invention also provides an application of a wet-adhesion sealing material for metal surfaces in sealing leaks in metal structures in high humidity or underwater environments, wherein the application involves coating the sealing material onto the leaking part of the metal structure.

[0027] Preferably, the coating area is 5-10 times the leakage area.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. Polyphenolic substances with high wet adhesion are covalently introduced into the epoxy network structure through chemical grafting to obtain polyphenol-modified epoxy compounds. By utilizing the interfacial complexation between the polyphenol structure in the resin molecular chain and the metal substrate, the sealing material is endowed with excellent intrinsic wet adhesion properties, which can effectively seal leaks in metal pipelines operating in high humidity and underwater environments.

[0030] 2. A polyphenol-modified epoxy compound is mixed with bisphenol A type epoxy resin to form a modified epoxy mixture. Then, silane-modified nanoparticles are used as an adjuvant accelerator, and a mixture of polyamine curing agent, polythiol curing agent, and curing accelerator is used as a curing agent. The resulting mixture yields a metal surface wet-adhesion sealing material with excellent strength and toughness. Coating the prepared sealing material onto metal pipes provides good impact resistance and crack propagation resistance, meeting the requirements for sealing materials used in pressure pipelines. Furthermore, the sealing material can be used in high-humidity or underwater environments and effectively seals leaks in metal structures.

[0031] 3. The construction method of the metal surface wet adhesion sealing material provided by the present invention is simple, has a wide range of applications, is easy to be applied on a large scale, and has broad prospects. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the molecular structure of the polyphenol-modified epoxy compound in Example 1.

[0033] Figure 2 The image shows the infrared spectrum of the polyphenol-modified epoxy compound in Example 1.

[0034] Figure 3This is a stress curve diagram of the wet-adhesive sealing material on the metal surface in Example 1.

[0035] Figure 4 This is a photograph of the actual leak-sealing material obtained in Example 1 using the wet adhesion sealing material on the wet surface of a steel pressure pipeline after an adhesion test. Detailed Implementation

[0036] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. It is worth noting that the following embodiments are only preferred embodiments of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention should be determined by the contents of the claims. Modifications and substitutions made by those skilled in the art to the technical solution of the present invention without creative effort all fall within the scope of protection of the present invention.

[0037] Example 1

[0038] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain a polyphenol-modified epoxy compound ( Figure 1 );

[0039] (2) Take 9 parts of epoxy resin E51 and 1 part of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0040] (3) Mix 1 part of nano iron oxide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (25 wt%), and add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano iron oxide is about 100 nm, and the stirring speed is 500 rpm.

[0041] (4) Mix 9 parts of polyamide 650 with 1 part of polythiol curing agent and 0.11 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain curing agent;

[0042] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0043] The polyphenol-modified epoxy compound prepared in step (1) was detected using an infrared spectrometer, and the results are as follows: Figure 2 As shown, after grafting caffeic acid, the absorption peak of the epoxy group in the infrared spectrum of polypropylene glycol diglycidyl ether (1059 cm⁻¹) is observed. -1The intensity decreased, and the characteristic absorption peak of phenolic hydroxyl groups (1350 cm⁻¹) appeared in the spectrum of polyphenol-modified epoxy compounds. -1 and 3350 cm -1 This indicates that caffeic acid was successfully grafted with polypropylene glycol diglycidyl ether.

[0044] Example 2

[0045] The method and steps are the same as in Example 1, except that caffeic acid in step (1) is replaced with gallic acid to prepare a wet-adhesion sealing material for metal surfaces. The specific implementation method is as follows:

[0046] (1) Dissolve 5 parts gallic acid and 5 parts polypropylene glycol diglycidyl ether in 100 parts anhydrous toluene, stir evenly, add 0.1 parts triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0047] (2) Take 9 parts of epoxy resin E51 and 1 part of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0048] (3) Mix 1 part of nano iron oxide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (mass percentage of 26 wt%), and add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano iron oxide is about 100 nm, and the stirring speed is 600 rpm;

[0049] (4) Mix 9 parts of polyamide 650 with 1 part of polythiol curing agent and 0.11 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain curing agent;

[0050] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0051] Example 3

[0052] The method and steps are the same as in Example 1, except that caffeic acid in step (1) is replaced with L-DOPA, and polypropylene glycol diglycidyl ether is replaced with butylene glycol diglycidyl ether, to prepare a wet-adhesion sealing material for metal surfaces. The specific implementation method is as follows:

[0053] (1) Dissolve 5 parts of levodopa and 5 parts of butanediol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0054] (2) Take 9 parts of epoxy resin E51 and 1 part of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0055] (3) Mix 1 part of nano iron oxide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (27 wt%), and add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano iron oxide is about 100 nm, and the stirring speed is 700 rpm;

[0056] (4) Mix 9 parts of polyamide 650 with 1 part of polythiol curing agent and 0.11 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain curing agent;

[0057] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0058] Example 4

[0059] The method and steps are the same as in Example 1, except that the amount of epoxy resin E51 in step (2) is changed to 8 parts and the amount of polyphenol-modified epoxy compound is changed to 2 parts to prepare a wet-adhesion sealing material for metal surfaces. The specific implementation method is as follows:

[0060] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0061] (2) Take 8 parts of epoxy resin E51 and 2 parts of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0062] (3) Mix 1 part of nano iron oxide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (mass percentage of 28 wt%), add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano iron oxide is about 100 nm, and the stirring speed is 800 rpm;

[0063] (4) Mix 9 parts of polyamide 650 with 1 part of polythiol curing agent and 0.11 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain curing agent;

[0064] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0065] Example 5

[0066] The method and steps are the same as in Example 4, except that polyamide 650 in step (4) is replaced with isophorone diamine to prepare a wet-adhesion sealing material for metal surfaces. The specific implementation method is as follows:

[0067] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0068] (2) Take 8 parts of epoxy resin E51 and 2 parts of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0069] (3) Mix 1 part of nano iron oxide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (mass percentage of 28 wt%), add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano iron oxide is about 100 nm, and the stirring speed is 800 rpm;

[0070] (4) Mix 2.5 parts of isophorone diamine with 1 part of polythiol curing agent and 0.11 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain curing agent;

[0071] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0072] Example 6

[0073] (1) Dissolve 6 parts of caffeic acid and 4 parts of glycerol triglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0074] (2) Take 9.5 parts of epoxy resin E54 and 0.5 parts of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0075] (3) Mix 1 part of metal-organic framework ZIF7 with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (28 wt%), and add 1 part of 3-glycidyl etheroxypropyltrimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of metal-organic framework ZIF7 is about 100 nm, and the stirring speed is 800 rpm;

[0076] (4) Mix 2 parts tetraethylenepentamine with 2 parts polythiol curing agent and 0.5 parts benzyl dimethylamine evenly to obtain curing agent;

[0077] (5) Take 4 parts of the modified epoxy mixture prepared in step (2), 4 parts of the curing agent prepared in step (4), and 0.05 parts of the adhesion promoter prepared in step (3), mix them evenly, and let them stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0078] Example 7

[0079] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0080] (2) Take 9 parts of epoxy resin E51 and 1 part of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0081] (3) Mix 1 part of nano silicon carbide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (25 wt%), and add 1 part of 3-aminopropyltriethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano silicon carbide is about 150 nm; the stirring speed is 500 rpm.

[0082] (4) Mix 4 parts of phenolic amine T31 with 1 part of polythiol curing agent and 0.2 parts of resorcinol evenly to obtain the curing agent;

[0083] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0084] Comparative Example 1

[0085] (1) Mix 1 part of nano iron oxide (particle size about 100 nm) with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (mass percentage of 25 wt%), and then add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the stirring speed is 500 rpm;

[0086] (2) Mix 9 parts of polyamide 650, 1 part of polythiol curing agent, and 0.1 part of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain a curing agent;

[0087] (3) Mix 3.5 parts of epoxy resin E51, 3 parts of curing agent and 0.1 parts of adhesion promoter evenly, let stand for 5 minutes, and obtain the sealing material.

[0088] Comparative Example 2

[0089] (1) Mix 1 part of nano zinc oxide (particle size about 200 nm) with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (mass percentage of 25 wt%), and then add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the stirring speed is 500 rpm;

[0090] (2) Mix 4 parts of phenolic amine T31, 1 part of polythiol curing agent, and 0.2 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain the curing agent;

[0091] (3) Mix 3.5 parts of epoxy resin E54, 4 parts of curing agent and 0.1 parts of adhesion promoter evenly, let stand for 5 minutes, and obtain the sealing material.

[0092] Comparative Example 3

[0093] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0094] (2) Mix 1 part of nano zinc oxide (particle size about 200 nm) with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (mass percentage of 25 wt%), and then add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the stirring speed is 500 rpm.

[0095] (3) Mix 4 parts of phenolic amine T31, 1 part of polythiol curing agent, and 0.2 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain the curing agent;

[0096] (4) Mix 3.5 parts of polyphenol modified epoxy compound, 3 parts of curing agent and 0.1 parts of adhesion promoter evenly, let stand for 5 minutes, and obtain the sealing material.

[0097] Comparative Example 4

[0098] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0099] (2) Take 9 parts of epoxy resin E51 and 1 part of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0100] (3) Mix 1 part of nano zinc oxide (particle size about 200 nm) with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (mass percentage of 25 wt%), and then add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the stirring speed is 500 rpm.

[0101] (4) Mix 9 parts of polyamide 650 with 1 part of polythiol curing agent to obtain curing agent;

[0102] (5) Mix 3.5 parts of modified epoxy mixture, 3 parts of curing agent and 0.1 parts of adhesion promoter evenly, let stand for 5 minutes, and obtain the sealing material.

[0103] Comparative Example 5

[0104] The method and steps are the same as in Example 4, except that the curing agent in step (4) is changed to a mixture of 10 parts polyamide 650 and 0.3 parts 2,4,6-tris(dimethylaminomethyl)phenol to prepare the sealing material. The specific implementation method is as follows:

[0105] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0106] (2) Take 8 parts of epoxy resin E51 and 2 parts of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0107] (3) Mix 1 part of nano iron oxide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (25 wt%), and add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano iron oxide is about 100 nm, and the stirring speed is 500 rpm;

[0108] (4) Mix 10 parts of polyamide 650 with 0.3 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain a curing agent;

[0109] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0110] Comparative Example 6

[0111] The method and steps are the same as in Example 4, except that the curing agent in step (4) is changed to be obtained by mixing 10 parts of polythiol with 0.3 parts of 2,4,6-tris(dimethylaminomethyl)phenol to prepare the sealing material.

[0112] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0113] (2) Take 8 parts of epoxy resin E51 and 2 parts of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0114] (3) Mix 1 part of nano iron oxide with 50 parts of anhydrous ethanol, ultrasonically disperse for 10 min, add 2 parts of ammonia water (25 wt%), and add 1 part of (3-mercaptopropyl)trimethoxysilane while stirring, and continue stirring for 2 h to obtain an adhesion promoter; wherein the particle size of nano iron oxide is about 100 nm, and the stirring speed is 500 rpm;

[0115] (4) Mix 10 parts of polythiol curing agent and 0.3 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain curing agent;

[0116] (5) Take 3.6 parts of the modified epoxy mixture prepared in step (2), 3 parts of the curing agent prepared in step (4), and 0.1 parts of the adhesion promoter prepared in step (3), mix them evenly, and let stand for 5 minutes to obtain a wet adhesion sealing material for metal surfaces.

[0117] Comparative Example 7

[0118] (1) Dissolve 5 parts of caffeic acid and 5 parts of polypropylene glycol diglycidyl ether in 100 parts of anhydrous toluene, stir evenly, add 0.1 parts of triphenylphosphine, and then place in an oil bath at 120°C and stir for 6 hours to obtain polyphenol-modified epoxy compound.

[0119] (2) Take 9 parts of epoxy resin E51 and 1 part of the polyphenol-modified epoxy compound prepared in step (1) and mix them evenly to obtain a modified epoxy mixture;

[0120] (3) Mix 4 parts of phenolic amine T31, 1 part of polythiol curing agent, and 0.2 parts of 2,4,6-tris(dimethylaminomethyl)phenol evenly to obtain the curing agent;

[0121] (4) Mix 3.5 parts of modified epoxy mixture, 3 parts of curing agent and 0.1 parts of nano iron oxide evenly, let stand for 5 minutes, and obtain the sealing material.

[0122] Example 8

[0123] The sealing materials prepared in the above examples and comparative examples were tested for tensile strength and elongation at break. The testing methods were based on ASTM D638 standard. The results are shown in Table 1.

[0124] The sealing materials prepared in the above examples and comparative examples were applied to the leaking parts of steel pressure pipelines with cracks or micropores at a ratio of 5 times the leaking area. The materials were then cured at room temperature, with the relative humidity of the environment where the metal pressure pipeline was located being 80-95% (or 0.2-1m underwater). After curing for 24 hours, the adhesion test (GB / T 5210-2006) was used to test the bonding force between the sealing material and the metal pressure pipeline. The results are shown in Table 1.

[0125] Table 1. Performance of sealing materials and bonding strength after sealing.

[0126]

[0127] The results show that, through the comparison of Examples 1-7 and Comparative Examples 1-7, epoxy resin is one of the main matrix materials of the sealing material, which ensures the mechanical properties of the sealing material; the polyphenol-modified epoxy compound determines the performance of the sealing material in normal curing in humid environments and underwater, as well as its strong wet adhesion; the adhesion promoter can, to a certain extent, enhance the wet adhesion of the sealing material.

Claims

1. A wet adhesion patching material for metal surfaces, characterized by: The sealing material comprises the following raw materials in parts by weight: 36-40 parts modified epoxy mixture, 30-50 parts curing agent, and 0.5-5 parts adhesion promoter; The modified epoxy mixture is composed of a polyphenol-modified epoxy compound and a bisphenol A type epoxy resin, wherein the mass ratio of the polyphenol-modified epoxy compound to the bisphenol A type epoxy resin is 1:5-20. The polyphenol-modified epoxy compound is synthesized by reacting polyphenolic substances with glycidyl ethers. The polyphenolic substances are any one of gallic acid, levodopa, and caffeic acid. The glycidyl ethers are any one of polypropylene glycol diglycidyl ether, butylene glycol diglycidyl ether, and glycerol triglycidyl ether. The curing agent is composed of a polyamine-type curing agent, a polythiol curing agent, and a curing accelerator; the amount of the curing accelerator is 1%-5% of the total mass of the curing agent. The polyamine curing agent is any one of tetraethylenepentamine, isophorone diamine, polyamide 650, and phenolic amine T31; the curing accelerator is any one of 2,4,6-tris(dimethylaminomethyl)phenol, resorcinol, and benzyl dimethylamine. The adhesion promoter is silane-modified nanoparticles; the particle size of the nanoparticles is 50-200 nm, and the mass ratio of silane to nanoparticles is 1:1-5. The silane is any one of (3-mercaptopropyl)trimethoxysilane, 3-glycidyl etheroxypropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; the nanoparticles are any one of iron oxide, zinc oxide, silicon carbide, and metal-organic frameworks.

2. The metal surface wet adhesion sealing material according to claim 1, characterized in that: The bisphenol A type epoxy resin is any one of E51, E54, and E20.

3. A method for preparing a metal surface wet-adhesion sealing material as described in any one of claims 1-2, characterized in that: Includes the following steps: (1) Dissolve polyphenols and glycidyl ether in a solvent, mix well, add triphenylphosphine, and react to obtain polyphenol-modified epoxy compounds. (2) The polyphenol-modified epoxy compound was mixed with bisphenol A type epoxy resin to obtain a modified epoxy mixture; (3) After mixing and dispersing the nanoparticles with wastewater ethanol, ammonia water is added, and silane is added while stirring. Stirring is continued for 2-4 hours to obtain an adhesion promoter. (4) Mix the polyamine curing agent, polythiol curing agent, and curing accelerator evenly to obtain the curing agent; (5) Mix the modified epoxy mixture, curing agent and adhesion promoter evenly, let stand for 5-10 minutes to obtain a wet adhesion sealing material for metal surfaces.

4. The application of a metal surface wet adhesion sealing material as described in any one of claims 1-2 in sealing leaks in metal structures in high humidity or underwater environments, characterized in that: The application involves coating the leak-sealing material onto the leaking parts of a metal structure.

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