A protective coating for concrete components of a highway in a coastal environment and a method for preparing the same

Abstract

The application relates to the technical field of concrete member protection, and particularly discloses a highway concrete member protection coating under a coastal environment and a preparation method thereof. The highway concrete member protection coating under the coastal environment comprises an epoxy resin bottom layer and a fluorocarbon resin surface layer, the fluorocarbon resin surface layer is formed by spraying a surface layer coating, and the surface layer coating comprises the following raw materials in parts by weight: 28-32 parts of fluorocarbon resin, 3-5 parts of graphene oxide, 6-10 parts of montmorillonite, 10-14 parts of a stabilizing component, 160-170 parts of dimethylbenzene, the stabilizing component comprises a toughening agent, a leveling agent and a compatilizer, and the weight ratio of the toughening agent, the leveling agent and the compatilizer is 2-3:2-3:1. The protection coating can be used for protecting highway concrete members under a coastal environment.

Description

Technical Field

[0001] This application relates to the field of concrete component protection technology, and more specifically, it relates to a protective coating for highway concrete components in a coastal environment and its preparation method. Background Technology

[0002] Highway concrete components refer to concrete structures used on highways, such as culverts, underpasses, overpasses, side ditches, intercepting ditches, concrete protective slopes, concrete slope drainage, and retaining walls. In highway subgrade engineering, the use of precast concrete components can significantly reduce construction difficulty. For example, using precast roadbed slabs can reduce earthwork excavation and improve construction efficiency. At the same time, precast roadbed slabs have high load-bearing capacity and impermeability, which can greatly improve the stability and durability of the subgrade.

[0003] In coastal environments, protective coatings are typically applied to reduce the erosion of highway concrete components by chloride ions and other substances in the air. These protective coatings consist of an epoxy resin underlayer and a fluorocarbon resin top layer. However, the presence of dust and other impurities on the surface of the epoxy resin underlayer can lead to poor film formation and cracking of the fluorocarbon resin top layer, making it prone to peeling off. This results in the concrete components losing the protection of the fluorocarbon resin top layer and becoming more susceptible to erosion and damage, thus reducing their service life. Summary of the Invention

[0004] In order to improve the bonding strength of the protective coating and extend the protection period of the protective coating for concrete components, this application provides a protective coating for highway concrete components in coastal environments and its preparation method.

[0005] Firstly, this application provides a protective coating for highway concrete components in a coastal environment, employing the following technical solution:

[0006] A protective coating for highway concrete components in a coastal environment includes an epoxy resin base layer and a fluorocarbon resin top layer. The fluorocarbon resin top layer is formed by spraying a top coating, which comprises the following raw materials in parts by weight: 28-32 parts fluorocarbon resin, 3-5 parts graphene oxide, 6-10 parts montmorillonite, 10-14 parts stabilizing components, and 160-170 parts xylene. The stabilizing components include a toughening agent, a leveling agent, and a compatibilizer, and the weight ratio of the toughening agent, leveling agent, and compatibilizer is 2-3:2-3:1.

[0007] By adopting the above technical solution, the toughening agent and leveling agent are first uniformly dispersed in the raw materials by using a compatibilizer. The uniformly dispersed toughening agent enhances the overall toughness of the formed paint film, making it less prone to cracking. The leveling agent allows the toughening agent to flow on the surface of the epoxy resin substrate. When dust or other impurities adhere to the surface of the epoxy resin substrate, the tiny gaps between the dust and the epoxy resin substrate are covered by the toughening agent, thereby reducing the generation of bubbles. At this time, the coating combines with the dust and other impurities through the compatibilizer, and the toughening agent enhances the stability of the overall fluorocarbon resin surface film with dust adhering to it, making it less prone to cracking.

[0008] Preferably, the toughening agent comprises polyester polyol and nano titanium dioxide, wherein the weight ratio of the polyester polyol and nano titanium dioxide is 4:1.

[0009] By adopting the above technical solution, the branched chain of polyester polyol can effectively improve the bonding strength of each raw material, so that the polyester polyol can play the role of connecting each component. At the same time, nano titanium dioxide promotes the crystallization and solidification of polyester polyol, thereby improving the overall stability and strength of the fluorocarbon resin surface film formed by the coating.

[0010] Preferably, the leveling agent comprises an alicyclic epoxy resin and spherical zirconia micro powder, wherein the weight ratio of the alicyclic epoxy resin to the spherical zirconia micro powder is 3:2.

[0011] By adopting the above technical solutions, alicyclic epoxy resin and spherical zirconia micro powder improve the fluidity and wettability of the coating, reduce surface tension and reduce bubbles caused by surface defects of epoxy resin, which is conducive to the adhesion of dust and other substances by the coating. At the same time, the fluorocarbon resin surface film avoids stress instability and cracking caused by uneven coating due to uniform coating.

[0012] Preferably, the compatibilizer is dodecafluoroheptyltriethoxysilane.

[0013] By adopting the above technical solution, dodecylfluoroheptyltriethoxysilane allows the components to be added to the coating, making it easier for the raw materials to combine. At the same time, dodecylfluoroheptyltriethoxysilane combines with dust, making it easier for dust to adhere to the fluorocarbon resin surface film, thus improving cleanliness.

[0014] Preferably, the fluorocarbon resin topcoat is prepared by the following steps: dissolving thermoplastic resin in xylene, then adding graphene oxide, montmorillonite and stabilizing components, grinding and filtering to obtain the fluorocarbon resin topcoat.

[0015] By adopting the above technical solution and adding stabilizing components, the crack resistance of the fluorocarbon resin surface film is improved, and the poor film formation effect of the fluorocarbon resin surface film due to dust and other impurities on the epoxy resin surface is reduced, thereby reducing the cracking of the fluorocarbon resin surface film.

[0016] Preferably, the fluorocarbon resin surface coating further includes 0.2 to 0.4 parts of an ultraviolet curing initiator.

[0017] By adopting the above technical solution, an ultraviolet curing initiator is added to the coating raw material, and cross-linking curing is promoted by ultraviolet light irradiation, so that the fluorocarbon resin surface film can be more stably bonded to the epoxy resin underlayer, reducing the possibility of the fluorocarbon resin surface layer falling off due to impact.

[0018] Preferably, the fluorocarbon resin topcoat is prepared by the following steps: dissolving thermoplastic resin in xylene, then adding graphene oxide, montmorillonite, UV curing initiator and stabilizing components, grinding and filtering to obtain the fluorocarbon resin topcoat.

[0019] By adopting the above technical solution, the stability of film formation is first improved by stabilizing the components, so that the fluorocarbon resin surface film formed by the coating exists stably and cracking is reduced. At the same time, the addition of ultraviolet curing initiator promotes the curing of the fluorocarbon resin surface film, making the fluorocarbon resin surface film and the epoxy resin underlayer more stable.

[0020] Preferably, the epoxy resin underlayer is formed by spraying an epoxy resin underlayer coating, which comprises the following raw materials in parts by weight: 20 parts epoxy resin, 20 parts phenolic amine curing agent, and 25 parts xylene.

[0021] Secondly, this application provides a method for preparing a protective coating for highway concrete components in a coastal environment, employing the following technical solution:

[0022] A method for preparing a protective coating for highway concrete components in a coastal environment includes the following steps: S1, first applying an epoxy resin undercoat to coat the base layer with a thickness of 3 mm; S2, after the epoxy resin undercoat has cured, applying a fluorocarbon resin topcoat to coat the base layer with a thickness of 5 mm.

[0023] In summary, this application has the following beneficial effects:

[0024] 1. First, the toughening agent and leveling agent are evenly dispersed in the raw materials by using a compatibilizer. The evenly dispersed toughening agent enhances the overall toughness of the formed paint film, making it less prone to cracking. The leveling agent allows the toughening agent to flow on the surface of the epoxy resin substrate. When dust or other impurities adhere to the surface of the epoxy resin substrate, the tiny gaps between the dust and the epoxy resin substrate are covered by the toughening agent, thereby reducing the generation of bubbles. At this time, the coating combines with the dust and other impurities through the compatibilizer, and the toughening agent enhances the stability of the overall fluorocarbon resin surface film with dust adhering to it, making it less prone to cracking.

[0025] 2. First, by stabilizing the components, the film-forming stability is improved, so that the fluorocarbon resin surface film formed by the coating exists stably and cracking is reduced. At the same time, a UV curing initiator is added to promote the curing of the fluorocarbon resin surface film, making the fluorocarbon resin surface film and the epoxy resin underlayer more stable. Detailed Implementation

[0026] In this application, the polyester polyol was analytical grade AP 99%, purchased commercially. The graphene oxide had a mesh size of 500 and was purchased commercially. The montmorillonite had a mesh size of 800 and was purchased commercially. Xylene was used as a solvent and was purchased commercially. The nano-titanium dioxide had a particle size of 50 nm and was purchased commercially. The spherical zirconia micropowder had a mesh size of 2000 and was purchased commercially. The alicyclic epoxy resin was purchased commercially. The dodecafluoroheptyltriethoxysilane was purchased commercially.

[0027] The present application will be further described in detail below with reference to the embodiments.

[0028] Preparation Example

[0029] Preparation Example 1

[0030] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0031] S1. Mix 28kg of fluorocarbon resin with 160kg of xylene, stir to dissolve, then add 3kg of graphene oxide and 6kg of montmorillonite and stir evenly.

[0032] S2, then add 3.2 kg of polyester polyol, 0.8 kg of nano titanium dioxide, 2.4 kg of alicyclic epoxy resin, 1.6 kg of spherical zirconium oxide micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0033] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0034] Preparation Example 2

[0035] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0036] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0037] S2. Add 4 kg of polyester polyol, 1 kg of nano titanium dioxide, 3 kg of alicyclic epoxy resin, 2 kg of spherical zirconium oxide micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture.

[0038] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0039] Preparation Example 3

[0040] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0041] S1. Mix 32kg of fluorocarbon resin with 170kg of xylene, stir to dissolve, then add 5kg of graphene oxide and 10kg of montmorillonite and stir evenly.

[0042] S2, then add 4.8 kg of polyester polyol, 1.2 kg of nano titanium dioxide, 3.6 kg of alicyclic epoxy resin, 2.4 kg of spherical zirconium oxide micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0043] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0044] Preparation Example 4

[0045] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0046] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0047] S2. Add 5 kg of polyester polyol, 3 kg of alicyclic epoxy resin, 2 kg of spherical zirconia micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0048] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0049] Preparation Example 5

[0050] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0051] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0052] S2. Add 5kg of nano titanium dioxide, 3kg of alicyclic epoxy resin, 2kg of spherical zirconium oxide micro powder and 2kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture.

[0053] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0054] Preparation Example 6

[0055] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0056] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0057] S2. Add 4 kg of polyester polyol, 1 kg of nano titanium dioxide, 5 kg of alicyclic epoxy resin and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0058] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0059] Preparation Example 7

[0060] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0061] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0062] S2. Add 4 kg of polyester polyol, 1 kg of nano titanium dioxide, 5 kg of spherical zirconium oxide micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0063] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0064] Preparation Example 8

[0065] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0066] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 0.2kg of UV curing initiator, 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0067] S2. Add 4 kg of polyester polyol, 1 kg of nano titanium dioxide, 3 kg of alicyclic epoxy resin, 2 kg of spherical zirconium oxide micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture.

[0068] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0069] Preparation Example 9

[0070] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0071] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 0.4kg of UV curing initiator, 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0072] S2. Add 4 kg of polyester polyol, 1 kg of nano titanium dioxide, 3 kg of alicyclic epoxy resin, 2 kg of spherical zirconium oxide micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture.

[0073] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0074] Preparation Example 10

[0075] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0076] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0077] S2. Add 4 kg of polyester polyol, 1 kg of nano titanium dioxide, 3 kg of alicyclic epoxy resin and 2 kg of spherical zirconia micro powder and continue stirring to obtain a mixture;

[0078] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0079] Preparation Example 11

[0080] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0081] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0082] S2. Add 4 kg of polyester polyol, 1 kg of nano titanium dioxide and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0083] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0084] Preparation Example 12

[0085] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0086] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0087] S2. Add 3 kg of alicyclic epoxy resin, 2 kg of spherical zirconia micro powder and 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0088] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0089] Preparation Example 13

[0090] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0091] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0092] S2. Add 4 kg of polyester polyol and 1 kg of nano titanium dioxide and continue stirring to obtain a mixture;

[0093] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0094] Preparation Example 14

[0095] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0096] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0097] S2. Add 3 kg of alicyclic epoxy resin and 2 kg of spherical zirconia micro powder and continue stirring to obtain a mixture;

[0098] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0099] Preparation Example 15

[0100] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0101] S1. Mix 30kg of fluorocarbon resin with 165kg of xylene, stir to dissolve, then add 4kg of graphene oxide and 8kg of montmorillonite and stir evenly.

[0102] S2. Add 2 kg of dodecafluoroheptyltriethoxysilane and continue stirring to obtain a mixture;

[0103] S3. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0104] Preparation Example 16

[0105] This preparation example discloses a fluorocarbon resin topcoat coating, which is prepared by the following steps:

[0106] S1. Mix 30 kg of fluorocarbon resin with 165 kg of xylene, stir to dissolve, then add 4 kg of graphene oxide and 8 kg of montmorillonite and stir evenly to obtain a mixture.

[0107] S2. Grind the mixture using a paint grinder until the fineness after filtration is ≤5μm to obtain the paint.

[0108] Preparation Example 17

[0109] This preparation example discloses an epoxy resin primer coating, which is prepared by the following steps:

[0110] 20 kg of epoxy resin, 20 kg of phenolic amine curing agent and 25 kg of xylene were mixed and stirred evenly to obtain an epoxy resin base coat.

[0111] Example

[0112] Example 1

[0113] This embodiment discloses a method for preparing a protective coating for highway concrete components in a coastal environment, which includes the following steps: S1, first apply an epoxy resin primer coating to the base layer, the thickness of which is 3mm;

[0114] S2. After the epoxy resin base layer has cured, apply a fluorocarbon resin topcoat coating to the base layer. The topcoat thickness is 5mm.

[0115] Performance testing

[0116] Tensile strength of the film: The coating test was conducted in accordance with GB / T1040.1-2006, and the test item was tensile strength / MPa.

[0117] Coating peel strength: First, apply an epoxy resin primer to the surface of the galvanized steel sheet. After the epoxy resin primer has cured, apply a fluorocarbon resin topcoat on top. Peel off a portion of the coating by hand and use a universal electronic testing machine to measure the peel strength.

[0118] Table 1 Performance Test Table

[0119]

[0120]

[0121] Combining Preparation Examples 2, 10, 15, and 16 with Table 1, it can be seen that the branches of hyperbranched polyurethane can effectively improve the bonding strength of each raw material, allowing the polyester polyol to play a role in connecting the components. At the same time, nano-titanium dioxide promotes the crystallization and curing of the polyester polyol, thereby improving the overall stability and strength of the fluorocarbon resin surface film formed by the coating.

[0122] Combining Preparation Examples 2, 11, 14, and 16 with Table 1, it can be seen that alicyclic epoxy resin and spherical zirconia micro powder improve the fluidity and wettability of the coating, reduce surface tension and reduce defects such as bubbles caused by dust, thereby facilitating the bonding of the fluorocarbon resin topcoat to the epoxy resin topcoat while adhering to dust, etc., and at the same time, the fluorocarbon resin topcoat film is not easily affected and cracked.

[0123] Combining Preparation Examples 2, 12, 13, and 16 with Table 1, it can be seen that dodecylfluoroheptyltriethoxysilane makes it easier for each component to combine in the coating. At the same time, dodecylfluoroheptyltriethoxysilane combines with dust and enters the fluorocarbon resin topcoat coating, reducing the impact of dust on the fluorocarbon resin topcoat from the epoxy resin underlayer.

[0124] Combining Preparation Example 2 and Preparation Examples 10-16 with Table 1, it can be seen that, firstly, by using a compatibilizer, the toughening agent and leveling agent are uniformly dispersed in the raw materials. The uniformly dispersed toughening agent enhances the overall toughness of the formed paint film, making it less prone to cracking. The leveling agent allows the toughening agent to flow on the surface of the epoxy resin substrate. When dust or other impurities adhere to the surface of the epoxy resin substrate, the tiny gaps between the dust and the epoxy resin substrate surface are covered by the toughening agent, thereby reducing the generation of bubbles. At this time, the coating combines with the dust and other impurities through the compatibilizer, and the toughening agent enhances the stability of the overall fluorocarbon resin surface film with dust adhering to it, making it less prone to cracking.

[0125] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A protective coating for highway concrete components in a coastal environment, comprising an epoxy resin underlayer and a fluorocarbon resin toplayer, wherein the fluorocarbon resin toplayer is formed by spraying a topcoat, and the topcoat comprises the following raw materials in parts by weight: 28-32 parts fluorocarbon resin, 3-5 parts graphene oxide, 6-10 parts montmorillonite, 10-14 parts stabilizing component, and 160-170 parts xylene; wherein the stabilizing component comprises a toughening agent, a leveling agent, and a compatibilizer, and the weight ratio of the toughening agent, leveling agent, and compatibilizer is 2-3:2-3:1; the toughening agent comprises polyester polyol and nano-titanium dioxide, and the weight ratio of the polyester polyol and nano-titanium dioxide is 4:1; the leveling agent comprises alicyclic epoxy resin and spherical zirconia micropowder, and the weight ratio of the alicyclic epoxy resin and spherical zirconia micropowder is 3:2; and the compatibilizer is dodecafluoroheptyltriethoxysilane.

2. The protective coating for highway concrete components in a coastal environment according to claim 1, characterized in that: The fluorocarbon resin topcoat is prepared by the following steps: dissolving thermoplastic resin in xylene, then adding graphene oxide, montmorillonite and stabilizing components, grinding and filtering to obtain the fluorocarbon resin topcoat.

3. The protective coating for highway concrete components in a coastal environment according to claim 1, characterized in that: The fluorocarbon resin topcoat also includes 0.2 to 0.4 parts of ultraviolet light curing initiator.

4. The protective coating for highway concrete components in a coastal environment according to claim 1, characterized in that: The fluorocarbon resin topcoat is prepared by the following steps: dissolving thermoplastic resin in xylene, then adding graphene oxide, montmorillonite, UV curing initiator and stabilizing components, grinding and filtering to obtain the fluorocarbon resin topcoat.

5. The protective coating for highway concrete components in a coastal environment according to claim 1, characterized in that: The epoxy resin underlayer is formed by spraying an epoxy resin underlayer coating, which comprises the following raw materials in parts by weight: 20 parts epoxy resin, 20 parts phenolic amine curing agent, and 25 parts xylene.

6. The method for preparing a protective coating for highway concrete components in a coastal environment as described in any one of claims 1-5, characterized in that: S1. First, apply an epoxy resin base coat to the base layer, with a thickness of 3mm; S2. After the epoxy resin base coat has cured, apply a fluorocarbon resin top coat to the base layer, with a thickness of 5mm.

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