Coating and winding method anti-corrosion repair process based on underwater sealant

Abstract

The invention relates to the field of corrosion prevention and repair, and discloses a coating and winding method corrosion prevention and repair process based on underwater sealant, which comprises the following steps: S1, cleaning rust and attached marine organisms on an underwater structure by using tools such as a high-pressure water gun and a polisher, and polishing until the underwater structure is flat; s2, geotechnical cloth soaked with underwater sealant is spirally wound on the surface of the treated underwater structure, and the upper end and the lower end are fixed through ribbons after winding is completed; and S3, after the underwater sealant is cured, the cable tie is dismantled, and underwater structure anti-corrosion repairing construction is completed. Graphene nanosheets are introduced into the underwater sealant to form a three-dimensional conductive network, so that the material is endowed with good conductivity, and special engineering requirements are met; meanwhile, the bio-based chitosan derivative antibacterial agent can effectively inhibit bacterium breeding, reduce material performance reduction caused by microbial action, and improve the comprehensive performance of the material in a complex environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anticorrosion repair, in particular to an anticorrosion repair process based on underwater sealant coating and winding method. BACKGROUND

[0002] In the field of marine engineering, water conservancy facilities and other fields, underwater structures are long-term affected by harsh environmental factors such as seawater erosion, marine organism attachment and water flow scouring, which are prone to corrosion, damage and other problems. This not only reduces the safety and service life of the structure, but also may cause serious economic losses and safety hazards.

[0003] At present, the traditional underwater anticorrosion repair technology has many defects. In terms of underwater structure surface cleaning, the commonly used method is difficult to completely remove rust and attached marine organisms, resulting in insufficient adhesion between the subsequent repair material and the structure surface, affecting the repair effect, while in terms of repair material, many existing underwater sealants have poor performance. Some sealants have slow curing speed, long construction period, which increases the engineering cost and time cost; some sealants have poor corrosion resistance and aging resistance, and cannot effectively resist the erosion of seawater and other harsh environments for a long time, resulting in corrosion problems of the repaired structure again in a short period. At the same time, the existing sealants have poor anti-attachment effect on marine organisms, which cannot prevent marine organisms from growing on the surface of the repaired structure, further accelerating the corrosion of the structure. In addition, the existing underwater sealants mostly do not have good conductivity and antibacterial properties, which cannot meet the functional requirements of some special projects. The present application aims to solve the above problems and provides an anticorrosion repair process based on underwater sealant coating and winding method and underwater sealant, which effectively solves the problem of underwater structure anticorrosion repair and improves the durability and safety of the repaired structure through innovative material formula and advanced construction process. SUMMARY

[0004] In view of the shortcomings of the prior art, the present application provides an anticorrosion repair process based on underwater sealant coating and winding method, which solves the problem of underwater structure anticorrosion repair.

[0005] To achieve the above purpose, the present application is implemented by the following technical scheme: an anticorrosion repair process based on underwater sealant coating and winding method, comprising the following steps: S1. Clean the rust and attached marine organisms on the underwater structure with a high-pressure water gun, a grinder and other tools, and polish to smoothness; S2. Spiral winding of geotextile soaked with underwater sealant on the treated underwater structure surface, and fixing the upper and lower ends with a tie after winding is completed; S3. Remove the tie after the underwater sealant is cured, and complete the underwater structure anticorrosion repair construction.

[0006] An underwater sealant comprising component A, component B, component C and a functional enhancer, wherein the weight ratio thereof is (6-7): (2-3): (1): (0.5-1) Preferably, component A: 100-150 parts of 102C-4H elastomer-modified epoxy resin as the matrix, compounding 3-5 parts of liquid silicone rubber and 2-3 parts of polyurethane prepolymer to form a double network interpenetrating structure, adding 0.3-0.5 parts of fluorine-containing surfactant as a defoaming agent, and introducing 1-2 parts of graphene nanosheets as a conductive reinforcement phase.

[0007] Preferably, component B contains 100 parts of 1085 modified amine curing agent, 1-2 parts of DEH58 curing agent and 0.5-1 parts of microencapsulated latent curing agent, and the microcapsule rupture temperature is 60-80°C. Preferably, component C is composed of 100 parts of nano-titanium dioxide surface-modified with a silane coupling agent (KH-550) and 5-7 parts of carbon nanotubes, and is compounded with 3-5 parts of nano-halloysite tubes as a slow-release carrier, in which a benzotriazole corrosion inhibitor is loaded; the functional enhancer contains 0.3-0.5 parts of UV-326 ultraviolet absorber, 0.2-0.5 parts of nano-cerium oxide and 0.5-1 parts of a bio-based chitosan derivative antibacterial agent.

[0008] A preparation process of underwater sealant, step 1: in a nitrogen-protected reactor, add in proportion: Elastomer-modified epoxy resin and liquid silicone rubber are heated to 40-50°C and stirred for 30-40 minutes to form a preliminary cross-linked network. Isocyanate-type polyurethane prepolymer is injected and heated to 50-55°C. Ultrasonic-assisted dispersion is used for 15 minutes to construct an epoxy-polyurethane interpenetrating network. Subsequently, perfluoroalkyl ether carboxylate defoamer and graphene nanosheets are added in sequence for ultrasonic treatment.

[0009] Step 2: Preparation of component B: Mix the following substances in a vacuum degassing machine: modified amine curing agent, DEH58 curing agent, microencapsulated dicyandiamide, control the mixing temperature at 25-30°C, add nano-silica as a thixotropic agent, and stir at high speed for 10-15 minutes to form a stable suspension system.

[0010] Step 3: Preparation of component C and functional enhancer Nano-titanium dioxide is immersed in a silane coupling agent ethanol solution and refluxed at 80-85°C for 2-2.5 hours to obtain hydrophobically modified titanium dioxide. Benzotriazole is dissolved in ethanol and injected into a nano-halloysite tube. After vacuum adsorption and drying, a corrosion inhibitor loading system is formed.

[0011] Functional enhancer compounding, ultraviolet absorber, nano cerium oxide, carboxymethyl chitosan ball milling mixed until uniform Preferably, it further comprises step four: Primary mixing: mix the A component with the B component at 45-50 DEG C for 10-15 minutes with a planetary mixer; Secondary mixing: add the C component and the functional enhancer, and switch to high-speed dispersion mode; Tertiary mixing: inject deionized water, and defoam under a vacuum degree of -0.08 MPa.

[0012] Preferably, the implementation step S2 is wound from bottom to top, adopts a lap joint mode of spiral winding, and is wound 3-5 times.

[0013] Preferably, the geotextile wound in the implementation step S2 is polyester staple fiber needle-punched geotextile, which has high tensile strength, good permeability, aging resistance and corrosion resistance.

[0014] The application provides a corrosion repair process based on a water-sealed glue coating and winding method. 1、The graphene nanosheet introduced into the water-sealed glue forms a three-dimensional conductive network, which gives the material good conductivity and meets special engineering requirements; at the same time, the bio-based chitosan derivative antibacterial agent can effectively inhibit bacterial growth and reduce the decline in material performance caused by microorganisms, thereby improving the comprehensive performance of the material in complex environments.

[0015] 2、The application adopts a specific mixing process to accurately mix each component at different stages, so that the sealing glue has appropriate fluidity during construction, can be uniformly immersed in the geotextile, and can be quickly cured and formed, greatly shortening the construction time, improving the construction efficiency, reducing the construction difficulty, and reducing the excessive dependence on the skill level of underwater operation personnel.

[0016] 3、The corrosion repair process of the application is not only suitable for steel facilities, but also can efficiently repair underwater structures made of different materials such as concrete column structures, whether it is a concrete surface defect such as a pitted surface or a rusted surface, or the corrosion prevention and marine bio-attachment prevention of metal structures, which can be effectively solved by the process and materials of the application, greatly widening the application range of the application in the underwater engineering field. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The flowchart of the application. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the specification of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application. Embodiments

[0019] The embodiment of the present application provides a corrosion repair process based on underwater sealant coating and winding method, comprising S1. Use a high-pressure water gun, a sander and other tools to clean the rust and attached marine organisms on the underwater structure, and polish to be smooth; S2. Spiral winding geotextile soaked in underwater sealant on the treated underwater structure surface, fixing the upper and lower ends with a tie after winding is completed, winding from bottom to top, using the lap joint method of spiral winding, a total of 3-5 times, and the winding geotextile is polyester staple needle-punched geotextile, which has high tensile strength, good permeability, aging resistance and corrosion resistance; S3. After the underwater sealant is cured, remove the tie and complete the underwater structure corrosion repair construction.

[0020] Based on the above-mentioned underwater sealant, specifically comprising: The underwater sealant is composed of four parts of component A, component B, component C and functional enhancer, and the weight ratio is (6-7):(2-3):(1):(0.5-1), wherein: Component A: 100 parts of 102C-4H elastomer modified epoxy resin as matrix, 3-5 parts of liquid silicone rubber and 2-3 parts of polyurethane prepolymer to form a double-network interpenetrating structure, 0.3-0.5 parts of fluorine-containing surfactant (perfluoroalkyl ether carboxylate) as defoamer, and 1-2 parts of graphene nanosheet (thickness ≤5nm) as conductive reinforcing phase are added; Component B: dynamic curing system, containing 100 parts of 1085 modified amine curing agent, 1-2 parts of D.E.H.58 curing agent and 0.5-1 parts of microencapsulated latent curing agent (dicyandiamide@silica shell, particle size 20-50μm), and the microcapsule breakage temperature is 60-80℃; Component C: composed of 100 parts of nano-titanium dioxide surface modified by silane coupling agent (KH-550) and 5-7 parts of carbon nanotube, and 3-5 parts of Halloysite nanotube as slow-release carrier are compounded, and benzotriazole corrosion inhibitor is loaded in the tube; functional enhancer: containing 0.3 parts of UV-326 ultraviolet absorber, 0.2 parts of nano cerium oxide (CeO2, particle size 30nm) and 0.5 parts of bio-based chitosan derivative antibacterial agent.

[0021] A preparation process of underwater sealant, comprising the following steps: Step one, epoxy-silicone rubber pre-crosslinking In a nitrogen-protected reaction kettle, add the following ingredients in proportion: 100 parts of 102C-4H elastomer modified epoxy resin 4 parts of liquid silicone rubber (vinyl terminated, viscosity 5000 cP) Heat to 40°C and stir (speed 200 rpm) for 30 minutes to form a preliminary crosslinking network.

[0022] Inject 2.5 parts of isocyanate type polyurethane prepolymer (NCO content 12%) Heat to 50°C, disperse for 15 minutes with ultrasonic assistance (40 kHz, power 500 W) to build an epoxy-polyurethane interpenetrating network (IPN).

[0023] Then add the following ingredients in order: 0.4 parts of perfluoroalkyl ether carboxylate antifoam agent 1.5 parts of graphene nanosheet (thickness ≤ 3 nm, specific surface area 800 m² / g) Ultrasonic treatment (60 kHz, 20 min) under a magnetic field strength of 300 Gs to make the graphene align along the magnetic field direction and form a three-dimensional conductive network.

[0024] Step two: Preparation of the B component, main curing agent preparation, mix the following ingredients in a vacuum defoaming machine: 100 parts of 1085 modified amine curing agent 1.5 parts of D.E.H. 58 curing agent 0.8 parts of microencapsulated dicyandiamide (particle size 30 μm, shell thickness 2 μm, rupture temperature 65°C) The mixing temperature is controlled at 25°C to avoid premature rupture of the microcapsules.

[0025] And add 0.2 parts of nano-silicon dioxide (fumed, particle size 15 nm) as a thixotropic agent, high-speed stirring for 10 minutes at a shear rate of 1000 s⁻¹ to form a stable suspension system.

[0026] Step three, preparation of the C component and functional enhancer Immerse 100 parts of nano-titanium dioxide in a 3% silane coupling agent (KH-550) ethanol solution, and treat at 80°C for 2 hours to obtain hydrophobically modified titanium dioxide.

[0027] Dissolve 5 parts of benzotriazole in ethanol, inject into 5 parts of nano-helosite tubes (inner diameter 15 nm, length 1 μm), vacuum adsorb and dry at 60°C to form a corrosion inhibitor loading system.

[0028] Functional enhancer compounding Mix in proportion: 0.3 parts UV-326 ultraviolet absorber 0.2 parts of nano-cerium oxide (CeO2, particle size 30nm) 0.5 parts of carboxymethyl chitosan (degree of substitution ≥ 80%) Ball milling was performed (speed 300 rpm, time 2 h) until uniform.

[0029] Step 4: Primary mixing: Mix component A (6.5 parts) and component B (2.5 parts) at 45°C using a planetary mixer (revolution 15 rpm, rotation 30 rpm) for 10 minutes; Secondary mixing: Add component C (1 part) and functional enhancer (0.7 part) and switch to high-speed dispersion mode (2000 rpm, 5 minutes); Three-stage mixing: inject deionized water (3% of the total amount) and degas at a vacuum degree of -0.08MPa.

[0030] The mixed rubber is placed in an 800Gs pulsed magnetic field for 15 minutes to align the carbon nanotubes and graphene along a preset direction to form an anisotropic reinforced structure, thereby obtaining the final mixed rubber. When in use, the mixed rubber is immersed in a geotextile. The geotextile is a polyester staple fiber needle-punched geotextile with high tensile strength, good permeability, aging resistance, and corrosion resistance. Example

[0031] An underwater sealant is prepared using the method disclosed in patent document CN115558447A. The sealant comprises component A, component B, and component C. Component A is prepared by mixing 100 parts by weight of a 102C-4H elastomer-modified epoxy resin and 3-5 parts by weight of liquid silicone rubber, followed by adding 0.1-0.3 parts by weight of a defoamer and continuing to stir. Component B is prepared by mixing 100 parts by weight of a 1085 modified amine curing agent and 1-2 parts by weight of DEH58 bisphenol A-modified diethylenetriamine. Component C is prepared by mixing 100 parts by weight of nano-titanium dioxide and 5-7 parts by weight of carbon nanotubes. Component A, component B, and component C are mixed in a ratio of 6:3:1 to form a high-viscosity underwater sealant, which is then impregnated into geotextiles for use as anti-corrosion reinforcement wrapping.

[0032] In a specific embodiment, the underwater pile leg construction of an offshore bridge or oil platform includes: Use high-pressure water guns, grinders and other tools to clean rust, marine growth and other attachments from major rigid facilities such as offshore bridges, underwater pile legs of oil platforms, jackets, pipelines, etc., and grind them until they are smooth.

[0033] 3kg of component A, component B, and component C are prepared. Component A is prepared by mixing 100 parts by weight of 102C-4H elastomer-modified epoxy resin and 3-5 parts by weight of liquid silicone rubber, followed by adding 0.1-0.3 parts by weight of a defoamer and continuing to stir. Component B is prepared by mixing 100 parts by weight of a 1085 modified amine curing agent and 1-2 parts by weight of DEH58 bisphenol A-modified diethylenetriamine. Component C is prepared by mixing 100 parts by weight of nano-titanium dioxide and 5-7 parts by weight of carbon nanotubes in a ratio of 6:3:1. A high-viscosity underwater sealant is then prepared for use in geotextile wrapping tape. After curing, the underwater sealant exhibits excellent bonding strength, as well as excellent compressive strength (up to 75 MPa), tensile strength (up to 6.5 MPa), and elastic properties (elastic modulus: 84 MPa), enabling the production of ultra-strong structures for deepwater processing and reinforcement. Secondly, the underwater sealant provided by the present invention is highly effective in repairing and maintaining cracks and damage on facades and ceilings, eliminating the need for formwork or grouting. It can be applied at any angle, in any orientation, up and down, left and right, without any blind spots, and is unaffected by environmental and locational variations. Thirdly, the underwater sealant provided by the present invention is insoluble in water and exhibits high viscosity in water, ensuring excellent anti-seepage and leak-proofing effects with minimal loss during use. The underwater sealant provided by the present invention has a short underwater curing time and excellent sealing performance. The curing time can also be controlled by adjusting the amount of component B added, with the underwater curing time being controllable to between 20 minutes and 4 hours.

[0034] Wrap geotextile wrapping tape soaked in high-viscosity underwater adhesive around the treated surface of the structure, spirally wrapping from bottom to top, using a spiral overlap winding method for construction, with a total of 3 layers. After wrapping is completed, fix the upper and lower ends with cable ties; remove the cable ties after the adhesive solidifies, and the underwater rigid structure anti-marine growth and anti-corrosion construction is completed.

[0035] In another specific embodiment, the surface of the concrete column structure that needs to be repaired, such as the rough surface and exposed reinforcement, is first cleaned with a high-pressure water gun, a grinder, or other tools.

[0036] The obvious protruding parts on the surface of the concrete column and the smooth concrete surface are roughened.

[0037] Use evenly mixed high-viscosity underwater adhesive to fill and repair the defects and wait for it to solidify.

[0038] The geotextile soaked with high-viscosity underwater adhesive on the surface of the filled and repaired structure is overlapped in a spiral winding manner. After the winding is completed, the upper and lower ends are fixed with cable ties; after the adhesive is cured, the cable ties are removed to complete the surface repair and anti-corrosion construction of the underwater concrete structure.

[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A coating and winding anti-corrosion repair process based on underwater sealant, characterized in that: The following steps are involved: S1. Use a high-pressure water gun, grinder, or other tools to clean rust and attached marine organisms from underwater structures, and grind them until they are smooth. S2. Spirally wrap a geotextile soaked in underwater sealant around the treated underwater structure surface. Secure the top and bottom ends with cable ties. S3. After the underwater sealant cures, remove the cable ties to complete the underwater structure anti-corrosion repair work.

2. An underwater sealant according to claim 1, characterized in that: It includes component A, component B, component C and a functional enhancer, and the weight ratio thereof is (6-7): (2-3): (1): (0.5-1).

3. The underwater sealant according to claim 2, characterized in that: Component A: 100-150 parts of 102C-4H elastomer-modified epoxy resin is used as the matrix, 3-5 parts of liquid silicone rubber and 2-3 parts of polyurethane prepolymer are compounded to form a double network interpenetrating structure, 0.3-0.5 parts of fluorinated surfactant are added as a defoaming agent, and 1-2 parts of graphene nanosheets are introduced as a conductive reinforcement phase.

4. The underwater sealant according to claim 3, characterized in that: Component B contains 100 parts of 1085 modified amine curing agent, 1-2 parts of DEH58 curing agent and 0.5-1 parts of microencapsulated latent curing agent, and the microcapsule rupture temperature is 60-80°C.

5. The underwater sealant according to claim 3, characterized in that: Component C is composed of 100 parts of nano-titanium dioxide surface-modified with a silane coupling agent (KH-550) and 5-7 parts of carbon nanotubes, and is compounded with 3-5 parts of nano-halloysite tubes as a slow-release carrier, with benzotriazole corrosion inhibitors loaded inside the tubes; the functional enhancer contains 0.3-0.5 parts of UV-326 ultraviolet absorber, 0.2-0.5 parts of nano-cerium oxide and 0.5-1 parts of bio-based chitosan derivative antibacterial agent.

6. A process for preparing an underwater sealant according to any one of claims 2 to 5, characterized in that: Step 1: In a nitrogen-protected reactor, add: Elastomer-modified epoxy resin and liquid silicone rubber are heated to 40-50°C and stirred for 30-40 minutes to form a preliminary cross-linked network. Isocyanate-type polyurethane prepolymer is injected and heated to 50-55°C. Ultrasonic dispersion is used for 15 minutes to construct an epoxy-polyurethane interpenetrating network. Subsequently, perfluoroalkyl ether carboxylate defoamer and graphene nanosheets are added in sequence and ultrasonic treatment is performed. Step 2: Preparation of component B: Mix the following substances in a vacuum degassing machine: modified amine curing agent, DEH58 curing agent, and microencapsulated dicyandiamide. The mixing temperature is controlled at 25-30°C. Nano-silica is added as a thixotropic agent. Stir at high speed for 10-15 minutes to form a stable suspension system. Step 3: Preparation of component C and functional enhancer The nano-titanium dioxide is immersed in a silane coupling agent ethanol solution and refluxed at 80-85°C for 2-2.5 hours to obtain hydrophobically modified titanium dioxide. Benzotriazole is dissolved in ethanol and injected into a nano-halloysite tube. After vacuum adsorption, it is dried to form a corrosion inhibitor loading system. The functional enhancer is compounded by ball-milling the ultraviolet absorber, nano-cerium oxide and carboxymethyl chitosan until they are uniform.

7. The process for preparing underwater sealant according to claim 6, characterized in that: Also includes step four: First stage mixing: Mix component A and component B at 45-50°C with a planetary mixer for 10-15 minutes; Secondary mixing: add component C and functional enhancer, and switch to high-speed dispersion mode; Three-stage mixing: inject deionized water and degas at a vacuum degree of -0.08MPa.

8. The anti-corrosion repair process based on underwater sealant coating and winding method according to claim 1 is characterized in that: The S2 should be wound from bottom to top in a spiral winding overlap manner, and wound 3-5 times in total.

9. The anti-corrosion repair process based on underwater sealant coating and winding method according to claim 1 is characterized in that: The wrapped geotextile in S2 is a polyester staple fiber needle-punched geotextile with high tensile strength, good permeability, aging resistance and corrosion resistance.

Images