Anti-corrosion coating and its preparation method and application

Abstract

The present invention discloses an anti-corrosion coating, its preparation method and application. The preparation method of the anti-corrosion coating comprises: pre-treating a substrate with a pre-treatment liquid, applying a first primer liquid containing an adhesive, a cyanide oligomer and / or a cyanide monomer to the surface of the substrate to form a first primer layer; applying a second primer liquid containing an epoxy resin, a cyanide oligomer and / or a cyanide monomer to the surface of the first primer layer to form a second primer layer; then applying a functional coating thereon to form a functional coating; applying a transition coating liquid containing a coupling agent to the surface of the functional coating to form a transition layer; applying a fluorocarbon topcoat to the surface of the transition layer to form a topcoat to prepare an anti-corrosion coating. The anti-corrosion coating prepared by the present invention has good bonding strength, cathodic disbonding resistance and salt spray resistance, and is suitable for the protection of substrates in the intertidal zone of the transition zone between the ocean and the land.

Description

Technical Field

[0001] The present invention belongs to the field of anti-corrosion coatings, and in particular relates to an anti-corrosion coating and a preparation method and application thereof. Background Art

[0002] The intertidal zone, the transitional area between the ocean and land, refers to the coastline between the average highest and lowest tide levels, stretching from the area submerged by high tide to the area exposed to the surface by low tide. Influenced by tides, the intertidal zone is submerged twice daily and exposed to air twice daily. Therefore, structures and facilities in the intertidal zone are cyclically exposed to the tides, experiencing dramatic temperature fluctuations, large swings in humidity and salinity, and significant erosion by waves and tides, alternating wet and dry periods, and large fluctuations in oxygen concentration. We have a long and arduous journey in marine corrosion prevention.

[0003] Patent CN104073127B discloses a moisture-curing epoxy asphalt anticorrosive coating and its preparation method. This invention allows for normal application even in ambient humidity levels above 85%. This eliminates the need for dehumidification during application, significantly reducing energy consumption. Patent CN101638550A discloses a recoatable, universal epoxy anticorrosive paint with a single curing agent, enabling all-season application. This invention utilizes a low-molecular-weight bisphenol A epoxy resin as a base material and incorporates a branched reactive diluent into the formulation. This anticorrosive coating solves the problem of all-season application, exhibiting excellent cathodic disbonding resistance and compatibility with various topcoats, thereby improving ship coating efficiency. However, in the intertidal zone, the transition zone between ocean and land, due to the alternating wet and dry conditions and large fluctuations in oxygen concentration, coatings used to protect substrates require high bonding strength, disbonding resistance, and salt spray resistance to achieve optimal protection. Therefore, developing a specialized anticorrosive coating and process suitable for intertidal protection is an important measure for marine protection. Summary of the Invention

[0004] The main purpose of the present invention is to provide an anti-corrosion coating and a preparation method and application thereof, so as to overcome the deficiencies in the prior art.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0006] One aspect of the present invention provides a method for preparing an anti-corrosion coating, comprising:

[0007] Pre-treating the substrate with a previous treatment liquid;

[0008] applying a first primer solution containing an adhesive, a cyanide oligomer and / or a cyanide monomer to the surface of the substrate to form a first primer layer;

[0009] applying a second primer solution containing an epoxy resin, a cyanide oligomer and / or a cyanide monomer to the surface of the first primer layer to form a second primer layer;

[0010] Applying a functional coating to the surface of the second primer coating to form a functional coating, wherein the functional coating comprises asphalt, porous filler, self-repairing agent, epoxy micaceous iron intermediate paint and branched reactive diluent;

[0011] A transition coating liquid containing a coupling agent is applied to the surface of the functional coating to form a transition layer; a fluorocarbon topcoat is applied to the surface of the transition layer to form a topcoat to prepare an anti-corrosion coating.

[0012] Another aspect of the present invention provides an anti-corrosion coating prepared by the aforementioned preparation method, which includes a first primer layer, a second primer layer, a functional coating layer, a transition layer and a top coating layer.

[0013] Another aspect of the present invention also provides the use of the aforementioned anti-corrosion coating in the field of anti-corrosion.

[0014] Compared with the prior art, the technical solution of the present invention has at least the following advantages:

[0015] The anti-corrosion coating provided by the present invention has good bonding strength, cathodic disbonding resistance and salt spray resistance. According to tests, the bonding strength of the coating of the present invention can reach 28.5N / (mm 2 ) -1 The cathodic disbonding resistance can reach 1mm; the salt spray resistance can reach 5200 / h. It can be used in the field of marine corrosion protection, especially for the protection of substrates in the intertidal zone of the transition zone between ocean and land. DETAILED DESCRIPTION

[0016] The present invention will be more fully understood by reading the following detailed description. However, it should be understood that the detailed description disclosed below is merely exemplary of the present invention, and that the present invention may be embodied in a variety of forms. Therefore, the specific functional details disclosed herein should not be construed as limiting, but rather as a basis for the claims and as a representative basis for teaching those skilled in the art to variously employ the present invention in virtually any appropriately detailed embodiment.

[0017] As one aspect of the technical solution of the present invention, a method for preparing an anti-corrosion coating includes:

[0018] Pre-treating the substrate with a previous treatment liquid;

[0019] applying a first primer solution containing an adhesive, a cyanide oligomer and / or a cyanide monomer to the surface of the substrate to form a first primer layer;

[0020] applying a second primer solution containing an epoxy resin, a cyanide oligomer and / or a cyanide monomer to the surface of the first primer layer to form a second primer layer;

[0021] Applying a functional coating to the surface of the second primer layer to form a functional coating, wherein the functional coating comprises asphalt, a porous filler, a self-repairing agent, and a branched reactive diluent;

[0022] applying a transition coating liquid containing a coupling agent to the surface of the functional coating to form a transition layer;

[0023] A fluorocarbon topcoat is applied to the surface of the transition layer to form a topcoat to prepare an anti-corrosion coating.

[0024] The present invention uses cyanide oligomers and / or monomers in the primer layer to achieve moisture curing. At the same time, since such oligomer monomers can form good bonding force with the substrate during polymerization, the adhesion between the coating layers is effectively improved, and the coating peeling phenomenon caused by excessive coating thickness, impact or aging in the later stage is further effectively alleviated, so that the coating has excellent weather resistance and UV resistance, high and low temperature resistance and aging resistance; the binder makes the coating have high bonding strength and good bonding properties to glass and aluminum alloy.

[0025] The use of the functional coating in the present invention can not only effectively block the penetration and diffusion of moisture in a wet environment, but also effectively alleviate and eliminate the continuous damage and coating peeling caused by impact force, thereby making the coating have the dual functions of being both corrosion-resistant and fatigue-resistant.

[0026] The present invention uses fluorocarbon topcoat in the topcoat to achieve the functions of waterproofing, aging resistance and corrosion resistance.

[0027] Furthermore, the present invention uses oligomers / monomers with high-strength bonding strength to more effectively improve the interlayer bonding strength, so that an effective bond is formed inside the entire anti-corrosion coating system, further avoiding the peeling problem between layers, maximizing the coating effect, and achieving an effect of one plus one being greater than two, thereby effectively improving the overall anti-corrosion and corrosion resistance of the coating.

[0028] In some embodiments, the method for preparing the anti-corrosion coating includes: applying a pretreatment liquid to a substrate, wherein the pretreatment liquid includes a mixture of a quaternary ammonium salt corrosion inhibitor, an adhesion promoter, and a water-repellent.

[0029] Furthermore, the mass ratio of the quaternary ammonium salt corrosion inhibitor, the adhesion promoter and the waterproofing agent is 3:1:1-5:1:1.

[0030] Furthermore, the mass concentration of the mixture of the quaternary ammonium salt corrosion inhibitor, the adhesion promoter and the waterproofing agent in the pretreatment liquid is 5-10%.

[0031] In some embodiments, the quaternary ammonium salt corrosion inhibitor includes but is not limited to any one or a combination of two or more of an imidazoline quaternary ammonium salt corrosion inhibitor, a polyethyleneimine quaternary ammonium salt corrosion inhibitor, and a pyridinium quaternary ammonium salt corrosion inhibitor.

[0032] In some embodiments, the adhesion promoter includes, but is not limited to, any one or a combination of two or more of a phenoxydimethylsilane compound (HY-F4011), an aminosilane compound (Adherant 1121), and Catacure TIN-22. Adherant 1121 can enhance salt spray resistance.

[0033] In some embodiments, the waterproofing agent includes but is not limited to any one or a combination of two or more of Degussa P750, sodium methyl silicate, and potassium methyl silicate.

[0034] In some embodiments, the mass ratio of the binder to the cyanide oligomer and / or cyanide monomer in the first primer solution is 1:1-1:3.

[0035] In some embodiments, the binder includes but is not limited to alkali metal silicates, preferably any one of lithium silicate, sodium silicate, potassium silicate, or a combination of two or more thereof.

[0036] In some embodiments, the mass ratio of the epoxy resin to the cyanide oligomer and / or cyanide monomer in the second primer solution is 3:1-5:1.

[0037] In some embodiments, the epoxy resin includes but is not limited to any one or a combination of two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, novolac epoxy resin, and aromatic heterocyclic resin.

[0038] In some embodiments, the cyanide oligomer and / or cyanide monomer includes, but is not limited to, any one or a combination of two or more of ethyl cyanoacrylate, triphenylmethane triisocyanate, and polyisocyanate.

[0039] Furthermore, the polyisocyanate includes but is not limited to any one or a combination of two or more of diisocyanate, triisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, and isophorone polyisocyanate.

[0040] In some embodiments, the functional coating preparation method includes: first filling a porous filler with a self-healing agent, then coating the porous filler with asphalt, then adding the asphalt-coated porous self-healing material to an epoxy micaceous iron intermediate paint and mixing them evenly, and then diluting the mixture with a branched reactive diluent to produce the functional coating. The porous filler is coated with a soft, elastic asphalt to form a soft shell, which overcomes the rigidity of the coating. When impacted by tidal water, the coating can cushion and eliminate erosion through its soft shell, thus providing the coating with both corrosion and impact resistance.

[0041] In some embodiments, the asphalt includes, but is not limited to, any one of petroleum asphalt, shale asphalt, and coal tar asphalt, or a combination of two or more. The asphalt or tar component in the functional coating provides waterproofing, moisture resistance, and corrosion resistance, while also increasing the coating's peeling resistance and effectively preventing moisture penetration and diffusion in humid environments.

[0042] In some embodiments, the porous filler includes, but is not limited to, any one of zeolite, porous quartz powder, and porous silicon carbide, or a combination of two or more thereof.

[0043] In some preferred embodiments, the average particle size of the porous filler is 10-40 μm.

[0044] In some embodiments, the self-healing agent includes, but is not limited to, any one or a combination of two or more of dicyclopentadiene, epoxy resin, isocyanate, polyurethane, siloxane, and tung oil. Introducing a chelating resin into asphalt can further hinder the penetration of harmful ions in ambient water. Through its chelating action, the harmful ions are confined within a certain space, thereby achieving effective corrosion protection.

[0045] In some embodiments, the branched reactive diluent includes but is not limited to any one or a combination of two or more of ethylene glycol bisglycidyl ether, resorcinol bisglycidyl ether, and 1,6-hexanediol diacrylate (HDDA) containing two or more reactive groups.

[0046] In some embodiments, the functional coating is applied by methods including, but not limited to, spraying.

[0047] In some embodiments, the mass concentration of the coupling agent in the transition coating liquid is 30-50%.

[0048] In some embodiments, the coupling agent contains, but is not limited to, at least any two of amino, thiol, vinyl, epoxy, hydroxyl, and acyloxy groups.

[0049] Furthermore, the coupling agent includes but is not limited to a combination of any two of γ-(methacryloyloxy)propyltrimethoxysilane, 3-(triethoxysilyl)-1-propanethiol, γ-(methacryloyloxy)propyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane.

[0050] Furthermore, the mass ratio of the two coupling agents is 2:1-2:5.

[0051] In some preferred embodiments, the coupling agent includes a first coupling agent and a second coupling agent, wherein the molecule of the first coupling agent includes but is not limited to any one of an acyloxy group, a thiol group, and an epoxy group, including but not limited to any one of γ-(methacryloyloxy)propyltrimethoxysilane, 3-(triethoxysilyl)-1-propanethiol, γ-(methacryloyloxy)propyltriethoxysilane, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane; the molecule of the second coupling agent includes but is not limited to any one of a thiol group, a halogen group, and an amino group, including but not limited to any one of γ-mercaptopropyltrimethoxysilane and γ-aminopropyltrimethoxysilane.

[0052] In some embodiments, the fluorocarbon topcoat has a fluororesin content of 24-30% by mass and a solid content of 50-60%.

[0053] In some embodiments, the fluororesin includes but is not limited to any one of PPG2800 or KANPE FLON HD TOPCOAT tetrafluorocarbon coating or a combination of both.

[0054] In some embodiments, the first primer layer, the second primer layer, the transition layer, and the topcoat layer are applied in a manner including, but not limited to, at least one of spraying, brushing, and roller coating.

[0055] In some preferred embodiments, the first primer layer and the second primer layer are constructed using different processes. The first primer layer is formed into a relatively rough surface by roller coating, and the second primer layer is then sprayed. On the one hand, it is conducive to stronger adhesion between the coatings. On the other hand, the construction pressure of the spraying can embed the coating into the anchor points of the rough surface of the first primer layer, thereby strengthening the adhesion between the two coatings.

[0056] In some more specific embodiments, the method for preparing the anti-corrosion coating includes:

[0057] S1: First, remove debris and dust from the substrate, then rinse the substrate with a high-pressure water gun, and then apply the pretreatment liquid; the mass concentration of the mixture of quaternary ammonium salt corrosion inhibitor, adhesion promoter and waterproofing agent in the pretreatment liquid is 5-10%; the quaternary ammonium salt corrosion inhibitor, adhesion promoter and waterproofing agent are mixed in a mass ratio of 3:1:1-5:1:1;

[0058] S2: applying a first primer liquid to the surface of the substrate by spraying, brushing or roller coating to form a first primer layer; the mass ratio of the binder to the cyanide oligomer and / or cyanide monomer in the first primer liquid is 1:1-1:3;

[0059] S3: applying a second primer coating liquid to the surface of the first primer coating layer by spraying, brushing, or roller coating to form a second primer coating layer; the mass ratio of the epoxy resin to the cyanide oligomer and / or cyanide monomer in the second primer coating liquid is 3:1-5:1;

[0060] S4: When the second primer layer has not yet been completely cured, a functional coating is applied to the surface of the second primer layer by spraying or other means to form a functional coating; the preparation method of the functional coating comprises: first filling a self-healing agent into a porous filler, then coating the porous filler with asphalt, then adding the asphalt-coated porous self-healing material to an epoxy micaceous iron intermediate paint and mixing them evenly, and then diluting the mixture with a branched reactive diluent to obtain the functional coating;

[0061] S5: When the functional coating is dry and non-sticky, a transition coating liquid containing a coupling agent at a mass concentration of 30-50% is applied to the surface of the functional coating by spraying, brushing or roller coating to form a transition layer;

[0062] S6: After the transition layer is dry, a fluorocarbon topcoat having a fluororesin mass content of 24-30% and a solid content of 50-60% is applied to the surface of the transition layer by spraying, brushing or roller coating to form a topcoat to obtain an anti-corrosion coating.

[0063] As another aspect of the technical solution of the present invention, it also relates to an anti-corrosion coating prepared by the aforementioned method for preparing an anti-corrosion coating, which includes a first primer layer, a second primer layer, a functional coating, a transition layer and a top coating.

[0064] Furthermore, the thickness of the first primer layer is 5-10 μm.

[0065] Furthermore, the thickness of the second primer layer is 10-30 μm.

[0066] Furthermore, the thickness of the functional coating is 150-300 μm.

[0067] Furthermore, the thickness of the transition layer is 5-15 μm.

[0068] Furthermore, the thickness of the top coating is 30-50 μm.

[0069] As another aspect of the technical solution of the present invention, it also involves the application of the aforementioned anti-corrosion coating in the field of anti-corrosion.

[0070] Furthermore, the application includes: application of the anti-corrosion coating in marine protection.

[0071] Furthermore, the application includes: application of the anti-corrosion coating in the protection of the intertidal zone in the transition zone between the ocean and the land.

[0072] In summary, the intertidal anti-corrosion coating process disclosed in the present invention is a coating process designed for the characteristics of intertidal structural facilities. Through a design concept of external protection and internal penetration, materials that are resistant to aging, waterproof and moisture-proof, corrosion-resistant, wet-curing, and strongly adherent are used, and then the coating optimization process is used to achieve an unexpected protective effect on the structure. The process has simple pre-treatment requirements for the substrate, can be wet-cured, the raw materials are easily available, the coating method is simple, and the requirements for the construction environment are low. Therefore, the intertidal anti-corrosion coating prepared by the present invention and its coating process can be applied to the field of surface corrosion protection, especially marine protection, especially the intertidal area in the transition zone between the sea and the land, which is affected by the tide and has the characteristics of cyclic exposure, and has large changes in temperature and humidity, large changes in salinity, severe erosion by waves and tides, and the formation of dry and wet alternation, large changes in oxygen concentration, and other environmental characteristics of buildings or marine facilities.

[0073] The present invention is further illustrated by way of examples below, but the invention is not limited to the scope of the examples. The reagents and raw materials used in the following examples are commercially available, and the experimental methods where specific conditions are not specified are generally carried out under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0074] Example 1

[0075] (1) Substrate surface treatment:

[0076] First, remove debris and dust from the substrate, then rinse the substrate with a high-pressure water gun, and then apply a pretreatment solution containing an imidazoline quaternary ammonium salt corrosion inhibitor, Degussa P750 waterproofing agent, and a phenoxydimethylsilane compound (HY-F4011) adhesion promoter to the substrate surface; the quaternary ammonium salt corrosion inhibitor, waterproofing agent, and adhesion promoter are mixed in a mass ratio of 3:1:1, and the mass concentration of the mixture in the pretreatment solution is 5%.

[0077] (2) Primer coating:

[0078] The substrate was first coated with Primer 1, which consisted of a 1:1 ratio of lithium silicate binder to ethyl cyanoacrylate. The coating thickness was 5 μm. A second coat of Primer 2, consisting of a 5:1 ratio of bisphenol A epoxy resin to ethyl cyanoacrylate, was then applied. The coating thickness was 30 μm. The coating was applied by spraying.

[0079] (3) Preparation and coating of functional coatings:

[0080] First, the self-healing agent dicyclopentadiene is filled into a zeolite material with an average particle size of 10-20 μm, and then the zeolite is coated with petroleum asphalt. Then, the asphalt-coated porous self-healing material is added to the epoxy micaceous iron intermediate paint and stirred evenly, and then diluted with ethylene glycol diglycidyl ether to prepare a functional coating, wherein the mass ratio of dicyclopentadiene, zeolite, petroleum asphalt, ethylene glycol diglycidyl ether and epoxy micaceous iron intermediate paint is 1:5:10:5:40. Then, when the primer layer is not completely cured, the functional coating is applied on the primer surface by spraying, and the coating thickness is 150 μm.

[0081] (4) After the functional coating is applied and the coating is dry and not sticky, a transition layer is applied by brushing, with a coating thickness of 15 μm. The transition layer contains two coupling agents with a mass concentration of 30%, and the mass ratio of γ-(methacryloyloxy)propyltrimethoxysilane to γ-aminopropyltrimethoxysilane is 2:1.

[0082] (5) After the transition layer is applied and the surface is dried, a layer of PPG2800 fluorocarbon topcoat is applied on the surface by spraying with a coating thickness of 50 μm. The fluorocarbon topcoat contains 24% fluororesin by mass and 60% solid content.

[0083] The anti-corrosion coating was applied on the substrate surface according to the above process. After the coating was completely cured, it was placed for 7 days to test the various properties of the anti-corrosion coating. The results are shown in Table 1.

[0084] Example 2

[0085] (1) Substrate surface treatment:

[0086] First, remove debris and dust from the substrate, then rinse the substrate with a high-pressure water gun, and then apply a pretreatment solution containing a polyethyleneimine quaternary ammonium salt corrosion inhibitor, a sodium methyl silicate waterproofing agent, and an aminosilane compound (Adherant 1 121) adhesion promoter to the substrate surface; the quaternary ammonium salt corrosion inhibitor, the waterproofing agent, and the adhesion promoter are mixed in a mass ratio of 4:1:1, and the mass concentration of the mixture in the pretreatment solution is 7%.

[0087] (2) Primer coating:

[0088] The substrate was first coated with Primer 1, which consisted of a sodium silicate binder and triphenylmethane triisocyanate in a 1:2 ratio by mass. The coating thickness was 7 μm. A second coat of Primer 2, consisting of bisphenol F epoxy resin and triphenylmethane triisocyanate in a 4:1 ratio by mass, was then applied to the substrate to achieve a 20 μm thickness. The coating was applied by spraying.

[0089] (3) Preparation and coating of functional coatings:

[0090] The self-healing agent isocyanate is first injected into porous quartz powder with an average particle size of 20-30 μm. The porous quartz powder is then coated with shale asphalt. The asphalt-coated porous self-healing material is then added to an epoxy micaceous iron intermediate and mixed thoroughly. The mixture is then diluted with resorcinol bisglycidyl ether to produce a functional coating. The mass ratio of isocyanate, porous quartz powder, shale asphalt, resorcinol bisglycidyl ether, and epoxy micaceous iron intermediate is 2.5:6.5:14:6.5:48. The functional coating is then applied to the basecoat surface by spraying while the basecoat is still partially cured, with a coating thickness of 200 μm.

[0091] (4) After the functional coating is applied and the coating is dry and not sticky, a transition layer is applied by brushing, and the coating thickness is 12 μm; the transition layer contains two coupling agents with a mass concentration of 38%, and the mass ratio of γ-(2,3-epoxypropoxy)propyltrimethoxysilane to γ-mercaptopropyltrimethoxysilane is 1:1.

[0092] (5) After the transition layer is applied and the surface is dry, a layer of KANPE FLON HDTOPCOAT tetrafluorocarbon topcoat is applied on the surface by brushing, with a coating thickness of 40μm. The fluorocarbon topcoat contains 30% fluororesin by mass and 50% solid content.

[0093] The anti-corrosion coating was applied on the substrate surface according to the above process. After the coating was completely cured, it was placed for 7 days to test the various properties of the anti-corrosion coating. The results are shown in Table 1.

[0094] Example 3

[0095] (1) Substrate surface treatment:

[0096] First, remove debris and dust from the substrate, then rinse the substrate with a high-pressure water gun, and then apply a pretreatment solution containing a quaternary ammonium pyridine corrosion inhibitor, a potassium methyl silicate waterproofing agent, and a Catacure TIN-22 adhesion promoter to the substrate surface; the quaternary ammonium corrosion inhibitor, the waterproofing agent, and the adhesion promoter are mixed in a mass ratio of 5:1:1, and the mass concentration of the mixture in the pretreatment solution is 8%.

[0097] (2) Primer coating:

[0098] The substrate was first coated with Primer 1, which consisted of a potassium silicate binder and toluene diisocyanate in a 1:3 ratio by mass. The coating thickness was 10 μm. A second coat of Primer 2, consisting of bisphenol E epoxy resin and diphenylmethane diisocyanate in a 3:1 ratio by mass, was then applied to the substrate with a thickness of 10 μm. The coating was applied by spraying.

[0099] (3) Preparation and coating of functional coatings:

[0100] First, a porous silicon carbide material with an average particle size of 30-40 μm is filled with a self-healing epoxy resin. The porous silicon carbide is then coated with coal tar pitch. The asphalt-coated porous self-healing material is then added to an epoxy micaceous iron intermediate paint and mixed thoroughly. The mixture is then diluted with 1,6-hexanediol diacrylate (HDDA) to produce a functional coating. The mass ratio of epoxy resin, porous silicon carbide, coal tar pitch, 1,6-hexanediol diacrylate, and epoxy micaceous iron intermediate paint is 3.5:8.5:17:8.5:55. The functional coating is then applied to the base coat surface by spraying while the base coat is still not fully cured. The coating thickness is 250 μm.

[0101] (4) After the functional coating is applied and the coating is dry and not sticky, a transition layer is applied by roller coating with a coating thickness of 8 μm. The transition layer contains two coupling agents with a mass concentration of 42%, and the mass ratio of 3-(triethoxysilyl)-1-propanethiol and Y-aminopropyltrimethoxysilane is 1:2.

[0102] (5) After the transition layer is applied and the surface is dried, a layer of PPG2800 fluorocarbon topcoat is applied on the surface by roller coating with a coating thickness of 35 μm. The fluorocarbon topcoat contains 26% fluororesin by mass and 57% solid content.

[0103] The anti-corrosion coating was applied on the substrate surface according to the above process. After the coating was completely cured, it was placed for 7 days to test the various properties of the anti-corrosion coating. The results are shown in Table 1.

[0104] Example 4

[0105] (1) Substrate surface treatment:

[0106] First, remove debris and dust from the substrate, then rinse the substrate with a high-pressure water gun. Then, apply a pretreatment solution containing a polyethyleneimine quaternary ammonium salt corrosion inhibitor, Degussa P750 waterproofing agent, and Catacure TIN-22 adhesion promoter to the substrate surface. The quaternary ammonium salt corrosion inhibitor, waterproofing agent, and adhesion promoter are mixed in a mass ratio of 4:1:1, and the mass concentration of the mixture in the pretreatment solution is 10%.

[0107] (2) Primer coating:

[0108] The substrate was first coated with Primer 1, which consisted of a sodium silicate binder and triisocyanate in a 1:2 ratio by mass. The coating thickness was 8 μm. A second coat of Primer 2, consisting of a phenolic epoxy resin and triisocyanate in a 4:1 ratio by mass, was then applied to the substrate to achieve a 15 μm thickness. The coating was applied by spraying.

[0109] (3) Preparation and coating of functional coatings

[0110] The researchers first filled a porous silicon carbide material with an average particle size of 30-40 μm with tung oil, a self-healing agent, and then coated the porous silicon carbide with petroleum asphalt. The asphalt-coated porous self-healing material was then added to an epoxy micaceous iron intermediate paint and mixed thoroughly. The mixture was then diluted with resorcinol bisglycidyl ether to produce a functional coating. The mass ratio of tung oil, porous silicon carbide, petroleum asphalt, resorcinol bisglycidyl ether, and epoxy micaceous iron intermediate paint was 5:10:20:10:60. The functional coating was then applied to the base coat surface by spraying while the base coat was still partially cured, with a coating thickness of 300 μm.

[0111] (4) After the functional coating is applied and the coating is dry and not sticky, a transition layer is applied by spraying with a coating thickness of 5 μm. The transition layer contains two coupling agents with a mass concentration of 50%, and the mass ratio of γ-(methacryloyloxy)propyltriethoxysilane to γ-mercaptopropyltrimethoxysilane is 2:5.

[0112] (5) After the transition layer is applied and the surface is dried, a layer of KANPE FLON HDTOPCOAT tetrafluorocarbon topcoat is applied on the surface by spraying, with a coating thickness of 30 μm. The fluorocarbon topcoat contains 28% fluororesin by mass and 54% solid content.

[0113] The anti-corrosion coating was applied on the substrate surface according to the above process. After the coating was completely cured, it was placed for 7 days to test the various properties of the anti-corrosion coating. The results are shown in Table 1.

[0114] Comparative Example 1

[0115] The difference from Example 1 is that in this comparative example, the pretreatment liquid is not applied after the substrate is treated in step (1). The subsequent coating steps are the same. After the substrate is completely cured and placed for 7 days, the performance test is performed. The results are shown in Table 1.

[0116] Comparative Example 2

[0117] The difference from Example 2 is that in step (2), only Primer 2 is used instead of Primer 1. The subsequent coating steps are the same. After being completely cured, the performance test is carried out after being left for 7 days. The results are shown in Table 1.

[0118] Comparative Example 3

[0119] The difference from Example 2 is that in step (2), only Primer 1 was used instead of Primer 2. The subsequent coating steps were the same. After the coating was completely cured and left for 7 days, performance testing was performed. The results are shown in Table 1.

[0120] Comparative Example 4

[0121] Different from Example 3, in this comparative example, the functional coating used in step (3) does not include asphalt-coated porous fillers. The subsequent coating steps are the same. After complete curing, the coating is placed for 7 days before performance testing. The results are shown in Table 1.

[0122] Comparative Example 5

[0123] The difference from Example 4 is that step (4) is omitted in this comparative example, and the fluorocarbon topcoat is directly applied without applying the transition layer. The subsequent coating steps are the same. After being completely cured, the performance test is carried out after being placed for 7 days. The results are shown in Table 1.

[0124] Test items: Cathodic disbonding resistance GB / T7790-1996, salt spray resistance GB / T1771-2007, bonding strength GB / T5210-2006

[0125] Table 1 Test results of various properties of coatings in various embodiments and comparative examples

[0126]

[0127] From the data in Table 1, it can be seen that the bonding strength, salt spray resistance and cathodic disbonding resistance of the coatings after using pretreatment liquid, primer 1, primer 2, adding asphalt-coated porous fillers and applying a transition layer are significantly better.

[0128] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments using other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0129] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for preparing an anti-corrosion coating, characterized in that: include: Pre-treating the substrate with a previous treatment liquid; Applying a first primer solution containing a binder, a cyanide oligomer and / or a cyanide monomer to the surface of the substrate to form a first primer layer; the binder includes any one of lithium silicate, sodium silicate, and potassium silicate, or a combination of two or more thereof; applying a second primer solution containing an epoxy resin, a cyanide oligomer and / or a cyanide monomer to the surface of the first primer layer to form a second primer layer; The self-repairing agent is filled into a porous filler, and the porous filler is then coated with asphalt. The asphalt-coated porous self-repairing material is then added to an epoxy micaceous iron intermediate paint and mixed evenly, and then diluted with a branched reactive diluent to prepare a functional coating. The mass ratio of the self-repairing agent, porous filler, asphalt, branched reactive diluent and epoxy micaceous iron intermediate paint is (1-5): (5-10): (10-20): (5-10): (40-60). The self-repairing agent includes any one or a combination of two or more of dicyclopentadiene, epoxy resin, isocyanate, polyurethane, silicone, and tung oil. The branched reactive diluent includes any one or a combination of two or more of ethylene glycol diglycidyl ether containing two or more reactive groups, resorcinol diglycidyl ether, and 1,6-hexanediol diacrylate. applying the functional coating to the surface of the second primer layer to form a functional coating; applying a transition coating liquid containing a coupling agent to the surface of the functional coating to form a transition layer; A fluorocarbon topcoat is applied to the surface of the transition layer to form a topcoat to prepare an anti-corrosion coating.

2. The preparation method according to claim 1, characterized in that include: The substrate is coated with a pre-treatment liquid comprising a mixture of a quaternary ammonium salt corrosion inhibitor, an adhesion promoter and a waterproofing agent.

3. The preparation method according to claim 2, characterized in that The mass ratio of the quaternary ammonium salt corrosion inhibitor, the adhesion promoter and the waterproofing agent is 3:1:1-5:1:

1.

4. The preparation method according to claim 2, wherein The mass concentration of the mixture of the quaternary ammonium salt corrosion inhibitor, the adhesion promoter and the waterproofing agent in the pretreatment liquid is 5-10%.

5. The preparation method according to claim 2, characterized in that The quaternary ammonium salt corrosion inhibitor includes any one of an imidazoline quaternary ammonium salt corrosion inhibitor, a polyethyleneimine quaternary ammonium salt corrosion inhibitor, and a pyridine quaternary ammonium salt corrosion inhibitor, or a combination of two or more thereof.

6. The preparation method according to claim 2, wherein The adhesion promoter includes any one of a phenoxydimethylsilane compound, an aminosilane compound, and Catacure TIN-22, or a combination of two or more thereof.

7. The preparation method according to claim 2, characterized in that The waterproofing agent includes any one of Degussa P750, sodium methyl silicate, and potassium methyl silicate, or a combination of two or more thereof.

8. The preparation method according to claim 1, characterized in that The mass ratio of the binder to the cyanide oligomer and / or cyanide monomer in the first primer solution is 1:1-1:

3.

9. The preparation method according to claim 1, characterized in that The mass ratio of epoxy resin to cyanide oligomer and / or cyanide monomer in the second primer solution is 3:1-5:1; And / or, the epoxy resin includes any one or a combination of two or more of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, novolac epoxy resin, and aromatic heteroepoxy resin.

10. The preparation method according to claim 1, characterized in that The cyanide oligomer and / or cyanide monomer includes any one of ethyl cyanoacrylate and polyisocyanate or a combination of the two.

11. The preparation method according to claim 10, characterized in that: The polyisocyanate includes any one or a combination of two or more of triphenylmethane triisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, and isophorone polyisocyanate.

12. The preparation method according to claim 1, characterized in that The asphalt includes any one of petroleum asphalt, shale asphalt, coal tar asphalt, or a combination of two or more thereof.

13. The preparation method according to claim 1, characterized in that The porous filler includes any one of zeolite, porous quartz powder, and porous silicon carbide, or a combination of two or more thereof.

14. The preparation method according to claim 13, characterized in that The average particle size of the porous filler is 10-40 μm.

15. The preparation method according to claim 1, characterized in that The functional coating is applied in a manner including spraying.

16. The preparation method according to claim 1, characterized in that The mass concentration of the coupling agent in the transition coating solution is 30-50%.

17. The preparation method according to claim 1, characterized in that The coupling agent contains at least any two of amino, thiol, vinyl, epoxy, hydroxyl and acyloxy groups.

18. The preparation method according to claim 1, characterized in that The coupling agent includes a combination of any two of γ-(methacryloyloxy)propyltrimethoxysilane, 3-(triethoxysilyl)-1-propanethiol, γ-(methacryloyloxy)propyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane.

19. The preparation method according to claim 18, characterized in that The mass ratio of the two coupling agents is 2:1-2:

5.

20. The preparation method according to claim 18, characterized in that The coupling agent includes a first coupling agent and a second coupling agent, wherein the first coupling agent includes any one of γ-(methacryloyloxy)propyltrimethoxysilane, 3-(triethoxysilyl)-1-propanethiol, γ-(methacryloyloxy)propyltriethoxysilane, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane; and the second coupling agent includes any one of γ-mercaptopropyltrimethoxysilane and γ-aminopropyltrimethoxysilane.

21. The preparation method according to claim 1, characterized in that The mass content of the fluororesin in the fluorocarbon topcoat is 24-30%, and the solid content is 50-60%.

22. The preparation method according to claim 21, characterized in that The fluorocarbon topcoat includes any one of PPG2800 and KANPEFLON HD TOPCOAT or a combination of two of them.

23. The preparation method according to claim 1, characterized in that The first primer layer, the second primer layer, the transition layer, and the topcoat layer are applied in at least one of the following ways: spraying, brushing, and roller coating.

24. The anti-corrosion coating prepared by the preparation method according to any one of claims 1 to 23, comprising a first primer layer, a second primer layer, a functional coating layer, a transition layer and a top coating layer.

25. The anti-corrosion coating according to claim 24, characterized in that The thickness of the first primer layer is 5-10 μm; and / or the thickness of the second primer layer is 10-30 μm; and / or the thickness of the functional coating layer is 150-300 μm; and / or the thickness of the transition layer is 5-15 μm; And / or, the top coating has a thickness of 30-50 μm.

26. Use of the anti-corrosion coating according to claim 24 in the field of anti-corrosion.

27. The use according to claim 26, characterized in that The applications include: application of the anti-corrosion coating in marine protection.

28. The use according to claim 26, characterized in that The application includes: application of the anti-corrosion coating in the protection of the intertidal zone in the transition zone between the ocean and the land.

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