Modified graphene oxide and polyurea anticorrosive coating compositions and methods of making polyurea anticorrosive coatings

Abstract

The present application relates to the technical field of polyurea anticorrosive coating, and discloses a modified graphene oxide and polyurea anticorrosive coating composition and a method for preparing a polyurea anticorrosive coating. The modified graphene oxide is obtained by modifying graphene oxide with isocyanate silane. The polyurea anticorrosive coating composition contains polyurea anticorrosive coating component A and polyurea anticorrosive coating component B. The polyurea anticorrosive coating component A is prepared from raw materials containing aliphatic diisocyanate, aromatic diisocyanate, polyether polyol, bisphenol F type epoxy resin, stable rust converter, ester type viscosity reducer and modified graphene oxide. The polyurea anticorrosive coating component B is prepared from raw materials containing polyether polyamine, amino-terminated chain extender, light stabilizer hindered amine, ultraviolet absorber and silane coupling agent. The polyurea anticorrosive coating composition provided by the present application has strong adhesion between the coating and the metal substrate, and can improve the barrier corrosion resistance to corrosive media.

Description

Technical Field

[0001] This invention relates to the field of polyurea anti-corrosion coating technology, specifically to a modified graphene oxide and polyurea anti-corrosion coating composition and a method for preparing the polyurea anti-corrosion coating. Background Technology

[0002] Coating anti-corrosion technology is an important means to mitigate the corrosion of metal-based materials. Common anti-corrosion coating products such as epoxy resin paint, polyurethane paint, and fluorocarbon paint rely on their dense structure to block and shield the intrusion and penetration of corrosive media into the substrate, thus producing a good substrate protection effect.

[0003] Polyurea anticorrosive coatings, an important branch of polyurethane coatings, are typically prepared by reacting prepolymers generated from the reaction of polyisocyanates and hydroxyl polyethers with compounds containing terminal amino or hydroxyl groups. They have broad application prospects in the research of waterproofing, seepage prevention, wear resistance, scratch resistance, and explosion-proof and impact-resistant materials. Compared with traditional epoxy resin-based anticorrosive coatings, polyurea coatings have a higher solids content, reducing VOC emissions and avoiding environmental pollution during construction. Furthermore, polyurea coatings can complete cross-linking and curing in a short time, forming a dense coating with fewer pinhole defects. This effectively shortens the construction cycle while ensuring that the coating's mechanical strength, flexibility, and barrier properties meet the requirements for metal protection. For example, patent CN201910739886.4 discloses a rigid high-temperature resistant polyurea anticorrosive coating and its preparation method, which adds ultra-tough polyetheramine to the coating to enhance the toughness of the coating and make it suitable for anticorrosive operations in high-temperature (160℃) environments; and patent CN201810940993.9 discloses a high-performance environmentally friendly modified polyurea anticorrosive coating and its preparation method, which improves the degree of crosslinking inside the coating by incorporating cobalt naphthenate catalyst.

[0004] However, based on extensive field applications of coatings, the interaction between hydrogen atoms in the urea and urethane bonds of the polyurea structure and the metal surface is weak. Furthermore, the high viscosity of the coating results in a lack of wetting and spreading ability, making it difficult to penetrate the surface of metal substrates that have not been thoroughly derusted. This leads to weak bonding strength between the polyurea coating and the substrate, making it prone to peeling and detachment during service. Complex and detailed substrate surface pretreatment and the use of a primer are typically required, increasing the difficulty and time required for application. In addition, the coating's barrier properties against highly corrosive media need further improvement to enable its application in various protective scenarios. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of weak bonding strength between polyurea coatings and substrates and poor barrier properties against highly corrosive media in existing technologies. This invention provides a modified graphene oxide and polyurea anti-corrosion coating composition, as well as a method for preparing the polyurea anti-corrosion coating. The polyurea anti-corrosion coating composition provided by this invention, after spraying, forms a coating with strong adhesion to the metal substrate and simultaneously improves its barrier and corrosion resistance against corrosive media.

[0006] To achieve the above objectives, the present invention provides a modified graphene oxide obtained by modifying graphene oxide with isocyanate-based silane.

[0007] Preferably, the isocyanate-based silane is 3-isocyanate-propyltriethoxysilane and / or 3-isocyanate-propyltrimethoxysilane.

[0008] Preferably, the weight ratio of the graphene oxide to the isocyanate-based silane is 1:20 to 50, more preferably 1:25 to 40.

[0009] A second aspect of the present invention provides a method for preparing modified graphene oxide, the method comprising the following steps:

[0010] (1) Mix graphene oxide with an organic solvent and sonicate;

[0011] (2) Under an inert atmosphere, the solution obtained in step (1) is mixed with isocyanate-based silane and reacted, and the solid and liquid are separated to obtain modified graphene oxide.

[0012] Preferably, in step (1), the weight ratio of the graphene oxide to the organic solvent is 1:40 to 105, and more preferably 1:50 to 99.

[0013] Preferably, the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide and N,N-diethylformamide.

[0014] Preferably, in step (1), the conditions for ultrasound include: ultrasound temperature of 15-30°C, ultrasound time of 30-60 min, and ultrasound frequency of 20-35 kHz.

[0015] Preferably, the weight ratio of the graphene oxide to the isocyanate-based silane is 1:20 to 50, more preferably 1:25 to 40.

[0016] Preferably, in step (2), the reaction conditions include: a reaction temperature of 60–100°C and a reaction time of 12–48 h.

[0017] A third aspect of the present invention provides a polyurea anti-corrosion coating composition comprising polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B, wherein polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are stored independently.

[0018] The polyurea anti-corrosion coating component A is prepared from raw materials containing aliphatic diisocyanate, aromatic diisocyanate, polyether polyol, bisphenol F type epoxy resin, stabilized rust-reducing agent, ester viscosity reducer and modified graphene oxide, wherein the modified graphene oxide is the modified graphene oxide described in the first aspect above or the modified graphene oxide prepared by the method described in the second aspect above.

[0019] The polyurea anticorrosive coating component B is prepared from raw materials containing polyether polyamine, terminal amino chain extender, light stabilizer hindered amine, ultraviolet absorber and silane coupling agent.

[0020] Preferably, the weight ratio of the aliphatic diisocyanate, the aromatic diisocyanate, the polyether polyol, the bisphenol F epoxy resin, the stabilized rust-reducing agent, the ester viscosity reducer, and the modified graphene oxide is 30:28-44:24-38:5-10:6-15:1-2:0.5-2.

[0021] Preferably, the weight ratio of the polyether polyamine, the terminal amino chain extender, the light stabilizer steric amine, the ultraviolet absorber, and the silane coupling agent is 55:25-40:1-3:1-2:10-20.

[0022] Preferably, the aliphatic diisocyanate is selected from one or more of hexamethylene diisocyanate, hexamethylene diisocyanate trimer, methyl formate pentamethylene diisocyanate, and 2,2,4-trimethylhexane diisocyanate.

[0023] Preferably, the aromatic diisocyanate is selected from one or more of 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, p-phenylene diisocyanate, methylcyclohexyl diisocyanate, p-phenylenedimethylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 3,3'-dimethoxy-4,4′-diphenyl diisocyanate, and hydrogenated phenylmethane diisocyanate.

[0024] Preferably, the molecular weight of the polyether polyol is 200 to 3000.

[0025] Preferably, the polyether polyol is selected from one or more of polyoxypropylene ether diol, polytetrahydrofuran ether polyol, polyoxypropylene-ethylene oxide diol, and tetrahydrofuran-propylene oxide copolydiol.

[0026] Preferably, the epoxy equivalent of the bisphenol F type epoxy resin is 140-200 g / eq, and more preferably 150-190 g / eq.

[0027] Preferably, the rust stabilizer is selected from one or more of zinc phosphate, zinc chromate, and aluminum tripolyphosphate.

[0028] Preferably, the ester-based viscosity reducer is selected from one or more of dioctyl phthalate, dibutyl phthalate, ethyl carbonate, propylene carbonate, propanesulfonate lactone, 2-dimethylaminoethyl acetate, 2-chloroethyl ester, and dimethylaminoethyl acrylate.

[0029] Preferably, the polyether polyamine has a molecular weight of 100-3000, more preferably 200-2000.

[0030] Preferably, the terminal amino chain extender is selected from one or more of dimethylthiotoluenediamine, N,N'-disec-butyl-p-phenylenediamine, N,N'-dialkylphenylenediamine, N,N'-dialkylmethyldiamine, bis(p-aminobenzoic acid) propylene glycol ester, diethyltoluenediamine, and methyldiethanolamine.

[0031] Preferably, the light stabilizer steric amine is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and / or 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0032] Preferably, the ultraviolet absorber is selected from one or more of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (UV-P), 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol (UV-326), 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole (UV-327) and 2-hydroxy-4-n-octylbenzophenone (UV-531).

[0033] Preferably, the silane coupling agent is selected from one or more of γ-diethylenetriaminopropylmethyldimethoxysilane (KH-103), γ-aminopropyltriethoxysilane (KH-550), γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560), N-aminoethyl-3-aminopropylmethyldimethoxysilane (KH-602), and γ-aminoethylaminopropyltrimethoxysilane (KH-792).

[0034] Preferably, the preparation method of the polyurea anticorrosive coating component A includes:

[0035] S1. Dehydrate the polyether polyol;

[0036] S2. Under normal pressure and an inert atmosphere, the product obtained in step S1 is mixed with aliphatic diisocyanate, aromatic diisocyanate, bisphenol F epoxy resin, stabilized rust-reducing agent, ester viscosity reducer and modified graphene oxide for reaction.

[0037] Preferably, in step S1, the dehydration treatment conditions include: pressure of -0.05 to -0.15 MPa, temperature of 100 to 120°C, and time of 2 to 3 hours.

[0038] Preferably, in step S2, the reaction conditions include: a reaction temperature of 70–100°C, more preferably 80–90°C; and a reaction time of 1–6 h, more preferably 2–4 h.

[0039] Preferably, the preparation method of component B of the polyurea anticorrosive coating includes:

[0040] 1) Mix polyether polyamine and terminal amino chain extender and dehydrate them;

[0041] 2) Under normal pressure and an inert atmosphere, the product obtained in step 1) is mixed with the light stabilizer sterically hindered amine, the ultraviolet absorber and the silane coupling agent and reacted.

[0042] Preferably, in step 1), the dehydration treatment conditions include: pressure of -0.05 to -0.15 MPa, temperature of 90 to 110°C, and time of 2 to 3 hours.

[0043] Preferably, in step 2), the reaction conditions include: a reaction temperature of 50–80°C, more preferably 60–75°C; and a reaction time of 0.5–4 h, more preferably 1–2 h.

[0044] The fourth aspect of the present invention provides a method for preparing a polyurea anti-corrosion coating, the method comprising: mixing the polyurea anti-corrosion coating component A and the polyurea anti-corrosion coating component B and spraying the mixture onto the surface of a metal substrate, followed by curing, to obtain the polyurea anti-corrosion coating.

[0045] Preferably, the weight ratio of the polyurea anticorrosive coating component A to the polyurea anticorrosive coating component B is 1-1.2:1, more preferably 1.05-1.15:1.

[0046] Preferably, the spraying conditions include: a spraying temperature of 60–80°C and a spraying pressure of 14–16 MPa.

[0047] Preferably, the curing conditions include: a curing temperature of 15–30°C and a curing time of 5–9 days.

[0048] Preferably, the metal substrate is carbon steel material for the outer wall of the storage tank.

[0049] This invention employs a specific modifier to graft-modify graphene oxide, resulting in modified graphene oxide with abundant isocyanate functional groups and imine groups on its surface. When this modified graphene oxide is used as a filler in the preparation of polyurea anti-corrosion coating component A, it not only exhibits good compatibility and dispersibility within the polyurea anti-corrosion coating component A, but also significantly improves the mechanical properties, barrier properties against corrosive media, and corrosion resistance of the polyurea anti-corrosion coating obtained after spraying polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B onto a metal substrate. This enhances the durability and protective effect of the polyurea anti-corrosion coating in corrosive environments, extending its service life.

[0050] In the preparation of component A of the polyurea anti-corrosion coating, this invention modifies the polyurea anti-corrosion coating by compounding bisphenol F type epoxy resin and a stabilizing rust-reducing agent. This enables the polyurea anti-corrosion coating to form a strong adhesion to the metal substrate and the rusted metal surface, improving the adhesion between the polyurea anti-corrosion coating and the metal substrate, reducing the surface pretreatment requirements of the polyurea anti-corrosion coating, and allowing the polyurea anti-corrosion coating to be applied to rusted metal surfaces without primer, reducing the possibility of peeling failure during service. Simultaneously, the uniformly dispersed modified graphene oxide in the coating increases its barrier capacity, improving the durability and protective effect of the coating in corrosive environments. Attached Figure Description

[0051] Figure 1 These are the FTIR spectra of the graphene oxide and modified graphene oxide described in Example 1. Detailed Implementation

[0052] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0053] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0054] The first aspect of the present invention provides a modified graphene oxide obtained by modifying graphene oxide with isocyanate-based silane.

[0055] Modifying graphene oxide with isocyanate-based silanes allows isocyanate and imine groups to be grafted onto its surface. The resulting modified graphene oxide, used as a filler in polyurea anticorrosive coatings, can form hydrogen bonds with the coating matrix, achieving uniform dispersion of graphene oxide in the coating. This fully leverages the physicochemical advantages of the two-dimensional sheet structure of graphene oxide, extends the diffusion path of corrosive media, and improves the overall performance of the polyurea anticorrosive coating.

[0056] According to the present invention, preferably, the isocyanate-based silane is 3-isocyanate-propyltriethoxysilane and / or 3-isocyanate-propyltrimethoxysilane.

[0057] In this invention, to ensure that abundant isocyanate and imine groups are grafted onto the graphene oxide, and that the resulting modified graphene oxide exhibits good compatibility and dispersibility in component A of the polyurea anticorrosive coating, the amounts of graphene oxide and isocyanate-based silane must be appropriate. In specific embodiments, the weight ratio of graphene oxide to isocyanate-based silane can be 1:20–50, preferably 1:25–40, for example 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1:33, 1:34, 1:35, 1:36, 1:37, 1:38, 1:39, or 1:40.

[0058] A second aspect of the present invention provides a method for preparing modified graphene oxide, the method comprising the following steps:

[0059] (1) Mix graphene oxide with an organic solvent and sonicate;

[0060] (2) Under an inert atmosphere, the solution obtained in step (1) is mixed with isocyanate-based silane and reacted, and the solid and liquid are separated to obtain modified graphene oxide.

[0061] According to the present invention, the organic solvent can be any conventional choice in the art, as long as it can dissolve graphene oxide. In a specific embodiment, the organic solvent can be selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-diethylformamide, preferably N,N-dimethylformamide.

[0062] In this invention, there is no particular limitation on the ratio of graphene oxide to organic solvent. Specifically, in step (1), the weight ratio of graphene oxide to organic solvent can be 1:40 to 105, preferably 1:50 to 99, for example 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1:95 or 1:99.

[0063] In a specific embodiment, in step (1), the ultrasonic temperature can be 15-30℃, for example 15℃, 20℃, 25℃ or 30℃; the ultrasonic time can be 30-60min, for example 30min, 35min, 40min, 45min, 50min, 55min or 60min; and the ultrasonic frequency can be 20-35kHz, for example 20kHz, 25kHz, 30kHz or 35kHz.

[0064] In this invention, to ensure that abundant isocyanate and imine groups are grafted onto the graphene oxide, and that the resulting modified graphene oxide exhibits good compatibility and dispersibility in component A of the polyurea anticorrosive coating, the amounts of graphene oxide and isocyanate-based silane must be appropriate. In specific embodiments, the weight ratio of graphene oxide to isocyanate-based silane can be 1:20–50, preferably 1:25–40, for example 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1:33, 1:34, 1:35, 1:36, 1:37, 1:38, 1:39, or 1:40.

[0065] In a preferred embodiment, in step (2), the reaction temperature can be 60 to 100°C, for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C; the reaction time can be 12 to 48 hours, for example, 12 hours, 15 hours, 18 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours or 48 hours.

[0066] According to the present invention, specifically, in step (2), the reaction is carried out under stirring conditions. Preferably, the stirring speed is 800-1200 r / min.

[0067] According to the present invention, specifically, in step (2), the solid-liquid separation is performed by centrifugation; after solid-liquid separation, the obtained precipitate is repeatedly washed with dichloromethane to obtain modified graphene oxide.

[0068] A third aspect of the present invention provides a polyurea anti-corrosion coating composition comprising polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B, wherein polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are stored independently. In this invention, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are stored independently before spraying, and are mixed when sprayed onto the surface of a metal substrate.

[0069] According to the present invention, the polyurea anticorrosive coating component A is prepared from raw materials containing aliphatic diisocyanate, aromatic diisocyanate, polyether polyol, bisphenol F type epoxy resin, stabilizing rust-reducing agent, ester viscosity reducer and modified graphene oxide, wherein the modified graphene oxide is the modified graphene oxide described in the first aspect above or the modified graphene oxide prepared by the method described in the second aspect above.

[0070] The modified graphene oxide with isocyanate and imine groups grafted onto its surface provided by this invention can form hydrogen bonds with the coating matrix as a filler for preparing component A of polyurea anticorrosive coatings, thereby achieving uniform dispersion of graphene oxide in the coating. This fully leverages the physicochemical advantages of the two-dimensional sheet structure of graphene oxide, extends the diffusion path of corrosive media, enhances the corrosion resistance and mechanical strength of the polyurea anticorrosive coating, prolongs the service life of the coating, and improves the overall performance of the polyurea anticorrosive coating.

[0071] The raw materials for component A of the polyurea anti-corrosion coating prepared in this invention are compounded with low-viscosity bisphenol F type epoxy resin. The interaction between the hydroxyl and ether bonds on the bisphenol F type epoxy resin structure and the metal surface enhances the adhesion of the coating. Simultaneously, a rust-stabilizing agent is added to the coating, which can transform the rust on the metal substrate surface into a passivation layer of heteropolyacid complex with strong adhesion, thus providing excellent rust stabilization and allowing its application to rusted metal equipment surfaces.

[0072] According to the present invention, component B of the polyurea anticorrosive coating is prepared from raw materials containing polyether polyamine, terminal amino chain extender, light stabilizer hindered amine, ultraviolet absorber and silane coupling agent.

[0073] In this invention, in order to obtain a polyurea anti-corrosion coating with excellent overall performance, it is necessary to limit the proportion of each raw material used in preparing component A of the polyurea anti-corrosion coating to an appropriate range.

[0074] In a specific embodiment, the weight ratio of the aliphatic diisocyanate, the aromatic diisocyanate, the polyether polyol, the bisphenol F epoxy resin, the stabilized rust-reducing agent, the ester viscosity reducer, and the modified graphene oxide can be 30:28~44:24~38:5~10:6~15:1~2:0.5~2.

[0075] In this invention, in order to obtain a polyurea anti-corrosion coating with excellent overall performance, it is necessary to limit the proportion of each raw material used in the preparation of component B of the polyurea anti-corrosion coating to an appropriate range.

[0076] In a specific embodiment, the weight ratio of the polyether polyamine, the terminal amino chain extender, the light stabilizer steric amine, the ultraviolet absorber, and the silane coupling agent is 55:25-40:1-3:1-2:10-20.

[0077] According to the present invention, the aliphatic diisocyanate used to prepare component A of the polyurea anticorrosive coating can be a conventional choice in the art. In a preferred embodiment, the aliphatic diisocyanate can be selected from one or more of hexamethylene diisocyanate, hexamethylene diisocyanate trimer, methyl formate pentamethylene diisocyanate, and 2,2,4-trimethylhexane diisocyanate.

[0078] According to the present invention, the aromatic diisocyanate used to prepare component A of the polyurea anticorrosive coating can be a conventional choice in the art. In a preferred embodiment, the aromatic diisocyanate is selected from one or more of 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, p-phenylene diisocyanate, methylcyclohexyl diisocyanate, p-phenylenediethylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 3,3'-dimethoxy-4,4′-diphenyl diisocyanate, and hydrogenated phenylmethane diisocyanate.

[0079] In a specific embodiment of the present invention, the molecular weight of the polyether polyol can be 200 to 3000, for example 200, 400, 650, 800, 1000, 1500, 2000, 2500 or 3000.

[0080] In a preferred embodiment, the polyether polyol is selected from one or more of polyoxypropylene ether diol, polytetrahydrofuran ether polyol, polyoxypropylene-ethylene oxide diol, and tetrahydrofuran-propylene oxide copolydiol.

[0081] According to the present invention, the bisphenol F type epoxy resin can be any of the choices known to those skilled in the art, as long as it can provide hydroxyl and ether bonds.

[0082] In a specific embodiment, the epoxy equivalent of the bisphenol F type epoxy resin is 140–200 g / eq, preferably 150–190 g / eq; the source of the bisphenol F type epoxy resin is not limited, and it can be various commercially available products or self-made. In a preferred embodiment, the bisphenol F type epoxy resin can be selected from one or more of NPEF-170, EPON-862, REF-170, DER-321, DER-354, and PY-306.

[0083] According to the present invention, in order to transform the rust on the surface of a metal substrate into a passivation layer of heteropolyacid complex with strong adhesion and to play a good role in rust stabilization, in a preferred embodiment, the stabilizing rust-transforming agent may be selected from one or more of zinc phosphate, zinc chromate and aluminum tripolyphosphate.

[0084] In this invention, the type of lipid viscosity reducer is not limited. In a preferred embodiment, the lipid viscosity reducer may be selected from one or more of dioctyl phthalate, dibutyl phthalate, ethyl carbonate, propylene carbonate, propanesulfonate lactone, 2-dimethylaminoethyl acetate, 2-chloroethyl ester, and dimethylaminoethyl acrylate.

[0085] According to the present invention, the molecular weight of the polyether polyamine is 100-3000, preferably 200-2000; the source of the polyether polyamine is not limited, and it can be various commercially available products or self-made. In a preferred embodiment, the polyether polyamine is selected from one or more of polyetheramine T-403, polyetheramine T-430, polyetheramine T-1000, polyetheramine T-2000, polyetheramine D-230, polyetheramine D-400, polyetheramine D-2000, polyetheramine FL-1000, and polyetheramine ED-600.

[0086] In this invention, the terminal amino chain extender can be any of the various choices known to those skilled in the art. In a preferred embodiment, the terminal amino chain extender is selected from one or more of dimethylthiotoluene diamine, N,N'-disec-butyl-p-phenylenediamine, N,N'-dialkylphenylenediamine, N,N'-dialkylmethyldiamine, bis(p-aminobenzoic acid) propylene glycol ester, diethyltoluene diamine, and methyldiethanolamine.

[0087] In this invention, the sterically hindered light stabilizer amine can be a conventional choice in the art. In a preferred embodiment, the sterically hindered light stabilizer amine can be bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and / or 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0088] According to the present invention, the ultraviolet absorber can be any of the various choices known to those skilled in the art. In a preferred embodiment, the ultraviolet absorber can be selected from one or more of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (UV-P), 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol (UV-326), 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole (UV-327), and 2-hydroxy-4-n-octylbenzophenone (UV-531).

[0089] In this invention, the silane coupling agent can be a conventional choice in the art. In a preferred embodiment, the silane coupling agent can be selected from one or more of γ-diethylenetriaminopropylmethyldimethoxysilane (KH-103), γ-aminopropyltriethoxysilane (KH-550), γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560), N-aminoethyl-3-aminopropylmethyldimethoxysilane (KH-602), and γ-aminoethylaminopropyltrimethoxysilane (KH-792).

[0090] Furthermore, the present invention provides a method for preparing polyurea anticorrosive coating component A. In a preferred embodiment, the method for preparing polyurea anticorrosive coating component A includes:

[0091] S1. Dehydrate the polyether polyol;

[0092] S2. Under normal pressure and an inert atmosphere, the product obtained in step S1 is mixed with aliphatic diisocyanate, aromatic diisocyanate, bisphenol F epoxy resin, stabilized rust-reducing agent, ester viscosity reducer and modified graphene oxide for reaction.

[0093] In a specific implementation, in step S1, the pressure of the dehydration treatment can be -0.05 to -0.15 MPa, for example -0.05 MPa, -0.06 MPa, -0.07 MPa, -0.08 MPa, -0.09 MPa, -0.1 MPa, -0.11 MPa, -0.12 MPa, -0.13 MPa, -0.14 MPa, or -0.15 MPa; the temperature can be 100 to 120°C, for example 100°C, 105°C, 110°C, 115°C, or 120°C; and the time can be 2 to 3 hours, for example 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, or 3 hours.

[0094] In a more specific embodiment, step S1 includes: placing the polyether polyol in a reaction vessel under a pressure of -0.05 to -0.15 MPa, heating it to 100 to 120°C under stirring, and maintaining it for 2 to 3 hours.

[0095] According to the present invention, in step S2, the reaction temperature can be 70-100°C, preferably 80-90°C, for example 80°C, 82°C, 85°C, 88°C or 90°C; the reaction time can be 1-6 hours, preferably 2-4 hours, for example 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours.

[0096] In a specific embodiment, step S2 includes: under normal pressure and an inert atmosphere, the temperature of the reaction system in step (1) is reduced to 50-60°C, and then aliphatic diisocyanate, aromatic diisocyanate, bisphenol F epoxy resin, stabilized rust-reducing agent, ester viscosity reducer and modified graphene oxide are added. The temperature is raised to 80-90°C and stirred for 2-4 hours. After the reaction is completed, the system is cooled to 20-30°C and filtered to obtain polyurea anti-corrosion coating component A.

[0097] Furthermore, the present invention provides a method for preparing polyurea anticorrosive coating component B. In a preferred embodiment, the method for preparing polyurea anticorrosive coating component B includes:

[0098] 1) Mix polyether polyamine and terminal amino chain extender and dehydrate them;

[0099] 2) Under normal pressure and an inert atmosphere, the product obtained in step 1) is mixed with the light stabilizer sterically hindered amine, the ultraviolet absorber and the silane coupling agent and reacted.

[0100] In a specific embodiment, in step 1), the pressure of the dehydration treatment can be -0.05 to -0.15 MPa, for example -0.05 MPa, -0.06 MPa, -0.07 MPa, -0.08 MPa, -0.09 MPa, -0.1 MPa, -0.11 MPa, -0.12 MPa, -0.13 MPa, -0.14 MPa, or -0.15 MPa; the temperature can be 90 to 110°C, for example 90°C, 95°C, 100°C, 105°C, 110°C, or 120°C; and the time can be 2 to 3 hours, for example 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, or 3 hours.

[0101] In a more specific embodiment, step 1) includes: mixing polyether polyamine and terminal amino chain extender under a pressure of -0.05 to -0.15 MPa, stirring and heating to 90 to 110°C, and maintaining for 2 to 3 hours for dehydration treatment.

[0102] In a specific embodiment, in step 2), the reaction temperature can be 50-80°C, preferably 60-75°C, such as 60°C, 62°C, 65°C, 68°C, 70°C, 72°C or 75°C; the reaction time can be 0.5-4h, preferably 1-2h, such as 1h, 1.5h or 2h.

[0103] In a more specific embodiment, step 2) includes: under normal pressure and an inert atmosphere, lowering the temperature of the reaction system in step 1) to 50-60°C, then adding the light stabilizer hindered amine, the ultraviolet absorber and the silane coupling agent, raising the temperature to 50-80°C, stirring the reaction for 0.5-4 hours, and after the reaction is completed, waiting for the system to cool down to 20-30°C, filtering, and obtaining polyurea anticorrosive coating component B.

[0104] The fourth aspect of the present invention provides a method for preparing a polyurea anti-corrosion coating, the method comprising: mixing the polyurea anti-corrosion coating component A and the polyurea anti-corrosion coating component B and spraying the mixture onto the surface of a metal substrate, followed by curing, to obtain the polyurea anti-corrosion coating.

[0105] In this invention, the metal substrate can be pretreated before spraying. In a specific embodiment, acetone and / or ethanol are used to remove grease from the surface of the metal substrate, and then manual grinding and / or blasting are used to treat the surface of the metal substrate to St 2 or Sa 2.5 grade.

[0106] According to the present invention, the polyurea anti-corrosion coating component A and the polyurea anti-corrosion coating component B are mixed and sprayed onto the surface of a metal substrate to form a polyurea anti-corrosion coating on the surface of the metal substrate. Specifically, the weight ratio of the polyurea anti-corrosion coating component A to the polyurea anti-corrosion coating component B can be 1-1.2:1, preferably 1.05-1.15:1, for example 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1, 1.1:1, 1.11:1, 1.12:1, 1.13:1, 1.14:1 or 1.15:1.

[0107] In a specific embodiment, the spraying conditions include: the spraying temperature can be 60-80℃, for example 60℃, 65℃, 70℃, 75℃ or 80℃; the spraying pressure can be 14-16MPa, for example 14MPa, 14.5MPa, 15MPa, 15.5MPa or 16MPa.

[0108] According to the present invention, the maintenance conditions can be conventionally selected in the art. In a specific embodiment, the maintenance conditions include: the maintenance temperature can be 15-30°C, for example 15°C, 20°C, 25°C or 30°C; the maintenance time can be 5-9 days, for example 5 days, 6 days, 7 days, 8 days or 9 days.

[0109] The polyurea anti-corrosion coating prepared by this invention can be applied to external corrosion protection engineering of equipment in complex corrosive environments, which is of great practical significance for ensuring the safety of oil and gas storage and transportation and has strong application prospects. In a specific embodiment, the metal substrate is carbon steel material for the outer wall of the storage tank.

[0110] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0111] Example 1

[0112] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of hexamethylene diisocyanate (Yantai Wanhua), 28 parts by weight of p-phenylenemethylene diisocyanate (Dexin Chemical), 36 parts by weight of polyoxypropylene ether glycol PPG-1000 (Mitsui Chemicals, molecular weight 1000), 8 parts by weight of NPEF-170 (Nanya, epoxy equivalent 160-180 g / eq), 12 parts by weight of aluminum tripolyphosphate (Maclean), 1 part by weight of dioctyl phthalate (Shandong Xincheng), and 2 parts by weight of modified graphene oxide.

[0113] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine T-403 (BASF, molecular weight 403), 30 parts by weight of N,N'-dialkylphenyl diamine (Nanjing Kaitian), 1 part by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Chongqing Ruiya), 1 part by weight of UV-326 (Guangzhou Yinuo), and 12 parts by weight of KH-560 (Aldrich).

[0114] S1. Preparation process of modified graphene oxide

[0115] One part by weight of graphene oxide powder (Xianfeng Nano) was mixed with 50 parts by weight of N,N-dimethylformamide (Aldrich) and ultrasonically dispersed at 25°C for 45 min at an ultrasonic frequency of 20 kHz. The resulting mixture was placed in a nitrogen atmosphere and 32 parts by weight of 3-isocyanate-propyltriethoxysilane (Hengchang Chemical) were added. The reaction system was heated to 80°C and stirred at 1000 r / min for 24 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was then repeatedly washed with dichloromethane (Jinan Xichuan) to obtain modified graphene oxide.

[0116] S2, Preparation process of polyurea anti-corrosion coating component A

[0117] Polyoxypropylene ether glycol PPG-1000 was added to the reactor and heated to 100°C under a pressure of -0.1 MPa, and maintained for 2.5 h for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 50°C, hexamethylene diisocyanate, p-phenylenemethylene diisocyanate, NPEF-170, aluminum tripolyphosphate, dioctyl phthalate, and the modified graphene oxide prepared in step S1 were added according to the aforementioned ratio. The temperature was then raised to 80°C and stirred for 2 h. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0118] S3, Preparation process of polyurea anti-corrosion coating component B

[0119] In a reaction vessel, polyetheramine T-403 and N,N'-dialkylphenylenediamine were added according to the aforementioned ratio. Under a pressure of -0.1 MPa, the mixture was stirred and heated to 90°C and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 55°C, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, UV-326, and KH-560 were added according to the aforementioned ratio. The temperature was then raised to 70°C and stirred for 1.5 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0120] S4. Preparation process of polyurea anti-corrosion coating

[0121] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, rust removal is performed by spraying to treat the surface of the metal substrate to Sa 2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.13:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set at 70℃ and the spraying pressure is 14MPa. After curing at 25℃ for 7 days, the polyurea anti-corrosion coating can be obtained.

[0122] Example 2

[0123] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of hexamethylene diisocyanate trimer (Yantai Wanhua), 38 parts by weight of diphenylmethane-4,4′-diisocyanate (Hunsmay), 24 parts by weight of polyoxypropylene ether glycol PPG-2000 (Nantong Luer, molecular weight 2000), 10 parts by weight of EPON-862 (HEXION, epoxy equivalent 165-173 g / eq), 8 parts by weight of zinc phosphate (Guoyao Reagent), 1 part by weight of propylene carbonate (Jinan Pulai), and 1 part by weight of modified graphene oxide.

[0124] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine T-1000 (BASF, molecular weight 1000), 25 parts by weight of diethyltoluenediamine (Shandong Chuangyu), 2 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Chongqing Ruiya), 1 part by weight of UV-P (Nanjing Milan), and 16 parts by weight of KH-550 (Aldrich).

[0125] S1. Preparation process of modified graphene oxide

[0126] One part by weight of graphene oxide powder (prepared using the conventional Hummers method) was mixed with 99 parts by weight of N,N-dimethylformamide (Aldrich) and ultrasonically dispersed at 25°C for 50 min at an ultrasonic frequency of 25 kHz. The resulting mixture was placed in a nitrogen atmosphere and 25 parts by weight of 3-isocyanate-propyltrimethoxysilane (Yishun Chemical) were added. The reaction system was heated to 80°C and stirred at 800 r / min for 30 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged to separate the lower precipitate, which was then repeatedly washed with dichloromethane (Jinan Xichuan) to obtain modified graphene oxide.

[0127] S2, Preparation process of polyurea anti-corrosion coating component A

[0128] Polyoxypropylene ether glycol PPG-2000 was added to a reactor and heated to 100°C under a pressure of -0.1 MPa for 3 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 55°C, hexamethylene diisocyanate trimer, diphenylmethane-4,4′-diisocyanate, EPON-862, zinc phosphate, propylene carbonate, and the modified graphene oxide prepared in step S1 were added according to the aforementioned ratio. The temperature was then raised to 80°C and stirred for 3 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0129] S3, Preparation process of polyurea anti-corrosion coating component B

[0130] Polyetheramine T-1000 and diethyltoluenediamine were added to the reactor according to the aforementioned ratio. The mixture was heated to 100°C under a pressure of -0.1 MPa and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 50°C, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, UV-P, and KH-550 were added according to the aforementioned ratio. The temperature was then raised to 75°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0131] S4. Preparation process of polyurea anti-corrosion coating

[0132] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, rust removal is performed by spraying to treat the surface to Sa 2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.05:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set to 70℃ and the spraying pressure is 15MPa. After curing at 25℃ for 7 days, the polyurea anti-corrosion coating can be obtained.

[0133] Example 3

[0134] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of methyl methacrylate pentamethylene diisocyanate (Xi'an Kangnuo), 32 parts by weight of hydrogenated phenylmethane diisocyanate (Yantai Wanhua), 32 parts by weight of polyoxypropylene ether glycol PPG-1000 (BASF, molecular weight 1000), 5 parts by weight of DER-321 (DOW, epoxy equivalent 180-188 g / eq), 10 parts by weight of zinc phosphate (Guoyao Reagent), 1.5 parts by weight of propanesulfonate lactone (Jinan Zhenda), and 0.5 parts by weight of modified graphene oxide.

[0135] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine D-230 (BASF, molecular weight 230), 25 parts by weight of dimethylthiotoluene diamine (Jiangsu Runfeng), 1 part by weight of 4-benzoyloxy-2,2,6,6-tetramethylpiperidine (Shanghai Jizhi), 1 part by weight of UV-327 (Nanjing Milan), and 12 parts by weight of KH-602 (Nanjing Quanxi).

[0136] S1. Preparation process of modified graphene oxide

[0137] One part by weight of graphene oxide powder (Aldrich) was mixed with 50 parts by weight of N,N-dimethylacetamide (Aldrich) and ultrasonically dispersed at 25°C for 60 min at an ultrasonic frequency of 30 kHz. The resulting mixture was placed in a nitrogen atmosphere and 35 parts by weight of 3-isocyanate-propyltriethoxysilane (Hengchang Chemical) were added. The reaction system was heated to 80°C and stirred at 1000 r / min for 20 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was repeatedly washed with dichloromethane (Jinan Xichuan) to obtain modified graphene oxide.

[0138] S2, Preparation process of polyurea anti-corrosion coating component A

[0139] Polyoxypropylene ether glycol PPG-1000 was added to a reactor and heated to 110°C under a pressure of -0.1 MPa, and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure, nitrogen atmosphere, and the temperature was lowered to 60°C. Methyl methyl ether pentemethylene diisocyanate, hydrogenated phenylmethane diisocyanate, DER-321, zinc phosphate, propanesulfonate lactone, and the modified graphene oxide prepared in step S1 were added according to the aforementioned ratio. The temperature was then raised to 90°C and stirred for 3.5 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0140] S3, Preparation process of polyurea anti-corrosion coating component B

[0141] Polyetheramine D-230 and dimethylthiotoluene diamine were added to a reactor according to the aforementioned ratio. The mixture was heated to 100°C under a pressure of -0.1 MPa and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen atmosphere. After the temperature was lowered to 55°C, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, UV-327, and KH-602 were added according to the aforementioned ratio. The temperature was then raised to 60°C and the mixture was stirred for 1 hour. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0142] S4. Preparation process of polyurea anti-corrosion coating

[0143] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, the surface is manually polished to St 2 grade. Using a special polyurea coating spraying device, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.1:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set at 70℃ and the spraying pressure is 14MPa. After curing at 25℃ for 7 days, the polyurea anti-corrosion coating can be obtained.

[0144] Example 4

[0145] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of 2,2,4-trimethylhexane diisocyanate (Desmodur), 44 parts by weight of 3,3'-dimethoxy-4,4′-diphenyl diisocyanate (Hunan Jinjinle), 26 parts by weight of polytetrahydrofuran ether polyol PTMG-650 (Korea PTG, molecular weight 650), 6 parts by weight of DER-321 (DOW, epoxy equivalent 180-188 g / eq), 10 parts by weight of zinc phosphate (Guoyao Reagent), 1 part by weight of dibutyl phthalate (Aldrich), and 1 part by weight of modified graphene oxide.

[0146] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine D-400 (BASF, molecular weight 400), 40 parts by weight of methyldiethanolamine (Shandong Yousheng), 1 part by weight of 4-benzoyloxy-2,2,6,6-tetramethylpiperidine (Shanghai Jizhi), 3 parts by weight of UV-327 (Nanjing Milan), and 10 parts by weight of KH-560 (Aldrich).

[0147] S1. Preparation process of modified graphene oxide

[0148] One part by weight of graphene oxide powder (Aldrich) was mixed with 60 parts by weight of N,N-dimethylformamide (Aldrich) and ultrasonically dispersed at 25°C for 40 min at an ultrasonic frequency of 35 kHz. The resulting mixture was placed in a nitrogen atmosphere and 40 parts by weight of 3-isocyanate-propyltriethoxysilane (Hengchang Chemical) were added. The reaction system was heated to 80°C and stirred at 1200 r / min for 25 h. After the reaction system cooled naturally to room temperature, the black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was repeatedly washed with dichloromethane (Aldrich) to obtain modified graphene oxide.

[0149] S2, Preparation process of polyurea anti-corrosion coating component A

[0150] Polytetrahydrofuran ether polyol PTMG-650 was added to a reactor and heated to 100°C under a pressure of -0.1 MPa for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 50°C, 2,2,4-trimethylhexane diisocyanate, 3,3'-dimethoxy-4,4'-diphenyl diisocyanate, DER-321, zinc phosphate, dibutyl phthalate, and modified graphene oxide were added according to the aforementioned ratio. The temperature was then raised to 85°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0151] S3, Preparation process of polyurea anti-corrosion coating component B

[0152] Polyetheramine D-400 and methyldiethanolamine were added to the reactor according to the aforementioned ratio. The mixture was heated to 90°C under a pressure of -0.1 MPa and maintained for 3 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen atmosphere. After the temperature was lowered to 50°C, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, UV-327, and KH-560 were added according to the aforementioned ratio. The temperature was then raised to 75°C and the mixture was stirred for 1.5 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0153] S4. Preparation process of polyurea anti-corrosion coating

[0154] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, rust removal is performed by spraying to treat the surface to Sa 2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.15:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set to 70℃ and the spraying pressure is 16MPa. After curing at 25℃ for 7 days, the polyurea anti-corrosion coating can be obtained.

[0155] Example 5

[0156] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of hexamethylene diisocyanate (Yantai Wanhua), 30 parts by weight of methylcyclohexyl diisocyanate (Dexin Chemical), 29 parts by weight of polyoxypropylene ether glycol PPG-3000 (DU PONT, molecular weight 3000), 5 parts by weight of PY-306 (DOW, epoxy equivalent 156-167 g / eq), 6 parts by weight of zinc chromate (Aldrich), 1 part by weight of 2-chloroethyl ester (Jinan Yongchen), and 0.5 parts by weight of modified graphene oxide.

[0157] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine ED-600 (Hunsman, molecular weight 600), 32 parts by weight of bis(p-aminobenzoic acid) propylene glycol ester (Ningbo Yinuo), 2 parts by weight of 4-benzoyloxy-2,2,6,6-tetramethylpiperidine (Shanghai Jizhi), 1.5 parts by weight of UV-531 (Shandong Maofa), and 16 parts by weight of KH-792 (Qingdao Hengda).

[0158] S1. Preparation process of modified graphene oxide

[0159] One part by weight of graphene oxide powder (prepared using the conventional Hummers method) was mixed with 99 parts by weight of N,N-dimethylacetamide (Aldrich) and ultrasonically dispersed at 25°C for 55 min at an ultrasonic frequency of 25 kHz. The resulting mixture was placed in a nitrogen atmosphere and 28 parts by weight of 3-isocyanate-propyltriethoxysilane (Hubei Jiufenglong) were added. The reaction system was heated to 80°C and stirred at 900 r / min for 26 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was repeatedly washed with dichloromethane (Aldrich) to obtain modified graphene oxide.

[0160] S2, Preparation process of polyurea anti-corrosion coating component A

[0161] Tetrahydrofuran-propylene oxide copolydiol POM-111P was added to a reactor and heated to 110°C under a pressure of -0.1 MPa, and maintained for 3 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment, and the temperature was lowered to 60°C. Hexamethylene diisocyanate, methylcyclohexyl diisocyanate, PY-306, zinc chromate, 2-chloroethyl ester, and modified graphene oxide were added according to the aforementioned ratio. The temperature was then raised to 90°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0162] S3, Preparation process of polyurea anti-corrosion coating component B

[0163] Polyetheramine ED-600 and bis(p-aminobenzoic acid) propylene glycol ester were added to a reaction vessel according to the aforementioned ratio. The mixture was heated to 100°C under a pressure of -0.1 MPa and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen atmosphere. After the temperature was lowered to 60°C, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, UV-531, and KH-792 were added according to the aforementioned ratio. The temperature was then raised to 70°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0164] S4. Preparation process of polyurea anti-corrosion coating

[0165] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, rust removal is performed by spraying to treat the surface to Sa 2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.08:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set to 70℃ and the spraying pressure is 15MPa. After curing at 25℃ for 7 days, the polyurea anti-corrosion coating can be obtained.

[0166] Example 6

[0167] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of methyl formate pentamethylene diisocyanate (Xi'an Kangnuo), 35 parts by weight of terephthalamide diisocyanate (Tesco Chemical), 27 parts by weight of polyoxypropylene ether glycol PPG-400 (Lianji Chemical, molecular weight 400), 10 parts by weight of NPEF-170 (Nanya, epoxy equivalent 160-180 g / eq), 12 parts by weight of zinc chromate (Aldrich), 1 part by weight of ethyl carbonate (Guoyao Reagent), and 1.8 parts by weight of modified graphene oxide.

[0168] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine D-230 (Huntsman, molecular weight 230), 38 parts by weight of N,N'-dialkylphenyl diamine (Nanjing Kaitian), 3 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Chongqing Ruiya), 1 part by weight of UV-326 (Guangzhou Yinuo), and 16 parts by weight of KH-602 (Rongguang Chemical).

[0169] S1. Preparation process of modified graphene oxide

[0170] One part by weight of graphene oxide powder (Aldrich) was mixed with 85 parts by weight of N,N-diethylformamide (Aldrich) and ultrasonically dispersed at 30°C for 30 min at an ultrasonic frequency of 35 kHz. The resulting mixture was placed in a nitrogen atmosphere and 39 parts by weight of 3-isocyanate-propyltrimethoxysilane (Yishun Chemical) were added. The reaction system was heated to 85°C and stirred at 1200 r / min for 25 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was then repeatedly washed with dichloromethane (Jinan Xichuan) to obtain modified graphene oxide.

[0171] S2, Preparation process of polyurea anti-corrosion coating component A

[0172] Polyoxypropylene ether glycol PPG-400 was added to a reactor and heated to 100°C under a pressure of -0.13 MPa, and maintained for 2.5 h for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 55°C, methyl formate pentemethylene diisocyanate, terephthaloyl diisocyanate, NPEF-170, zinc chromate, ethyl carbonate, and the modified graphene oxide prepared in step S1 were added according to the aforementioned ratio. The temperature was then raised to 80°C and stirred for 2.5 h. After the reaction was completed, the reaction system was cooled to 25°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0173] S3, Preparation process of polyurea anti-corrosion coating component B

[0174] Polyetheramine D-230 and N,N'-dialkylphenylenediamine were added to a reactor according to the aforementioned ratio. The mixture was heated to 100°C under a pressure of -0.1 MPa and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 60°C, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, UV-326, and KH-602 were added according to the aforementioned ratio. The temperature was then raised to 75°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0175] S4. Preparation process of polyurea anti-corrosion coating

[0176] First, acetone is used to remove grease from the surface of the metal substrate. Then, rust removal is performed by spraying to treat the surface of the metal substrate to Sa 2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.15:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set to 80℃ and the spraying pressure is 14.5MPa. After curing at 25℃ for 8 days, the polyurea anti-corrosion coating can be obtained.

[0177] Example 7

[0178] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of 2,2,4-trimethylhexane diisocyanate (Desmodur), 40 parts by weight of methylcyclohexyl diisocyanate (Dexin Chemical), 29 parts by weight of polyether polyol 1000D (Shenghe Weiye, molecular weight 1000), 7 parts by weight of REF-170 (Huite Chemical, epoxy equivalent 160-180 g / eq), 6 parts by weight of aluminum tripolyphosphate (Aldrich), 1 part by weight of 2-dimethylaminoethyl acetate (Hengchang Chemical), and 0.5 parts by weight of modified graphene oxide.

[0179] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine ED-600 (Huntsman, molecular weight 600), 39 parts by weight of diethyltoluenediamine (Shandong Chuangyu), 3 parts by weight of 4-benzoyloxy-2,2,6,6-tetramethylpiperidine (Shanghai Jizhi), 2 parts by weight of UV-531 (Shandong Maofa), and 18 parts by weight of KH-103 (Jingtianwei Chemical).

[0180] S1. Preparation process of modified graphene oxide

[0181] One part by weight of graphene oxide powder (prepared using the conventional Hummers method) was mixed with 95 parts by weight of N,N-dimethylacetamide (Aldrich) and ultrasonically dispersed at 25°C for 50 min at an ultrasonic frequency of 20 kHz. The resulting mixture was placed in a nitrogen atmosphere and 28 parts by weight of 3-isocyanate-propyltrimethoxysilane (Yishun Chemical) were added. The reaction system was heated to 60°C and stirred at 900 r / min for 20 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was repeatedly washed with dichloromethane (Aldrich) to obtain modified graphene oxide.

[0182] S2, Preparation process of polyurea anti-corrosion coating component A

[0183] Polyether polyol 1000D was added to a reactor and heated to 100°C under a pressure of -0.1 MPa, and maintained for 3 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 60°C, 2,2,4-trimethylhexane diisocyanate, methylcyclohexyl diisocyanate, REF-170, aluminum tripolyphosphate, 2-dimethylaminoethyl acetate, and modified graphene oxide were added according to the aforementioned ratio. The temperature was then raised to 90°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0184] S3, Preparation process of polyurea anti-corrosion coating component B

[0185] Polyetheramine ED-600 and diethyltoluenediamine were added to a reactor according to the aforementioned ratio. The mixture was heated to 105°C under a pressure of -0.1 MPa and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen atmosphere. After the temperature was lowered to 60°C, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, UV-531, and KH-103 were added according to the aforementioned ratio. The temperature was then raised to 75°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 25°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0186] S4. Preparation process of polyurea anti-corrosion coating

[0187] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, the surface is manually polished to St 2 grade. Using a special polyurea coating spraying device, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.05:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set at 70℃ and the spraying pressure is 16MPa. After curing at 30℃ for 5 days, the polyurea anti-corrosion coating is obtained.

[0188] Example 8

[0189] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of hexamethylene diisocyanate trimer (Yantai Wanhua), 33 parts by weight of 3,3'-dimethoxy-4,4′-diphenyl diisocyanate (Hunan Jinjinle), 36 parts by weight of polytetrahydrofuran ether polyol PTMG-650 (Korea PTG, molecular weight 650), 6 parts by weight of EPON-862 (HEXION, epoxy equivalent 165-173 g / eq), 6 parts by weight of zinc phosphate (Guoyao Reagent), 1.5 parts by weight of propanesulfonate lactone (Dongsoh Chemical), and 0.5 parts by weight of modified graphene oxide.

[0190] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine D-400 (BASF, molecular weight 400), 30 parts by weight of diethyltoluenediamine (Shandong Chuangyu), 3 parts by weight of 4-benzoyloxy-2,2,6,6-tetramethylpiperidine (Shanghai Jizhi), 3 parts by weight of UV-531 (Shandong Maofa), and 12 parts by weight of KH-560 (Aldrich).

[0191] S1. Preparation process of modified graphene oxide

[0192] One part by weight of graphene oxide powder (Xianfeng Nano) was mixed with 90 parts by weight of N,N-dimethylformamide (Aldrich) and ultrasonically dispersed at 20°C for 40 min at an ultrasonic frequency of 35 kHz. The resulting mixture was placed in a nitrogen atmosphere and 34 parts by weight of 3-isocyanate-propyltriethoxysilane (Hengchang Chemical) were added. The reaction system was heated to 75°C and stirred at 1200 r / min for 35 h. After the reaction system cooled naturally to room temperature, the black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was repeatedly washed with dichloromethane (Aldrich) to obtain modified graphene oxide.

[0193] S2, Preparation process of polyurea anti-corrosion coating component A

[0194] Polytetrahydrofuran ether polyol PTMG-650 was added to a reactor and heated to 110°C under a pressure of -0.1 MPa, and maintained for 2.2 h for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment, and the temperature was lowered to 50°C. 2,2,4-trimethylhexane diisocyanate, 3,3'-dimethoxy-4,4'-diphenyl diisocyanate, DER-321, zinc phosphate, dibutyl phthalate, and modified graphene oxide were added according to the aforementioned ratio. The temperature was then raised to 85°C and stirred for 2 h. After the reaction was completed, the reaction system was cooled to 25°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0195] S3, Preparation process of polyurea anti-corrosion coating component B

[0196] Polyetheramine D-400 and diethyltoluenediamine were added to the reactor according to the aforementioned ratio. The mixture was heated to 90°C under a pressure of -0.1 MPa and maintained for 3 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen atmosphere. After the temperature was lowered to 50°C, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, UV-531, and KH-560 were added according to the aforementioned ratio. The temperature was then raised to 65°C and the mixture was stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 20°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0197] S4. Preparation process of polyurea anti-corrosion coating

[0198] First, ethanol is used to remove grease from the surface of the metal substrate, and then rust removal is performed by spraying to treat the surface to Sa2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.15:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set to 80℃ and the spraying pressure is 14MPa. After curing at 30℃ for 9 days, the polyurea anti-corrosion coating can be obtained.

[0199] Example 9

[0200] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of methyl methacrylate pentamethylene diisocyanate (Xi'an Kangnuo), 37 parts by weight of p-phenylenemethylene diisocyanate (Dexin Chemical), 37 parts by weight of polyoxypropylene ether glycol PPG-1000 (BASF, molecular weight 1000), 8 parts by weight of DER-354 (DOW, epoxy equivalent 167-174 g / eq), 10 parts by weight of zinc chromate (Aldrich), 1 part by weight of propanesulfonic acid lactone (Jinan Zhenda), and 2 parts by weight of modified graphene oxide.

[0201] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine FL-1000 (Hunsmann, molecular weight 1000), 26 parts by weight of dimethylthiotoluene diamine (Jiangsu Runfeng), 1 part by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Chongqing Ruiya), 1.5 parts by weight of UV-327 (Nanjing Milan), and 18 parts by weight of KH-602 (Nanjing Quanxi).

[0202] S1. Preparation process of modified graphene oxide

[0203] One part by weight of graphene oxide powder (Aldrich) was mixed with 75 parts by weight of N,N-dimethylacetamide (Aldrich) and ultrasonically dispersed at 30°C for 55 min at an ultrasonic frequency of 30 kHz. The resulting mixture was placed in a nitrogen atmosphere and 34 parts by weight of 3-isocyanate-propyltriethoxysilane (Hengchang Chemical) were added. The reaction system was heated to 80°C and stirred at 1000 r / min for 48 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was repeatedly washed with dichloromethane (Jinan Xichuan) to obtain modified graphene oxide.

[0204] S2, Preparation process of polyurea anti-corrosion coating component A

[0205] Polyoxypropylene ether glycol PPG-1000 was added to a reactor and heated to 100°C under a pressure of -0.15 MPa, and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure, nitrogen atmosphere, and the temperature was lowered to 60°C. Methyl methyl ether pentemethylene diisocyanate, hydrogenated phenylmethane diisocyanate, DER-354, zinc chromate, propanesulfonate lactone, and the modified graphene oxide prepared in step S1 were added according to the aforementioned ratio. The temperature was then raised to 80°C and stirred for 3.5 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0206] S3, Preparation process of polyurea anti-corrosion coating component B

[0207] Polyetheramine FL-1000 and dimethylthiotoluene diamine were added to a reactor according to the aforementioned ratio. The mixture was heated to 105°C under a pressure of -0.1 MPa and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen atmosphere. After the temperature was lowered to 60°C, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, UV-327, and KH-602 were added according to the aforementioned ratio. The temperature was then raised to 60°C and the mixture was stirred for 1.5 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0208] S4. Preparation process of polyurea anti-corrosion coating

[0209] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, rust removal is performed by spraying to treat the surface to Sa 2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.1:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set to 70℃ and the spraying pressure is 15.5MPa. After curing at 25℃ for 7 days, the polyurea anti-corrosion coating can be obtained.

[0210] Example 10

[0211] The raw materials for preparing component A of the polyurea anticorrosive coating include: 30 parts by weight of hexamethylene diisocyanate (Yantai Wanhua), 39 parts by weight of p-phenylenemethylene diisocyanate (Dexin Chemical), 24 parts by weight of polyoxypropylene ether glycol PPG-1500 (Daixu Chemical, molecular weight 1500), 8 parts by weight of DER-321 (DOW, epoxy equivalent 180-188 g / eq), 15 parts by weight of aluminum tripolyphosphate (Maclean), 1 part by weight of 2-dimethylaminoethyl acetate (Hengchang Chemical), and 1 part by weight of modified graphene oxide.

[0212] The raw materials for preparing component B of the polyurea anticorrosive coating include: 55 parts by weight of polyetheramine T-430 (BASF, molecular weight 430), 36 parts by weight of N,N'-dialkylphenylenediamine (Nanjing Kaitian), 2.5 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Chongqing Ruiya), 1 part by weight of UV-P (Jianchu Biotechnology), and 12 parts by weight of KH-550 (Aldrich).

[0213] S1. Preparation process of modified graphene oxide

[0214] One part by weight of graphene oxide powder (prepared using the conventional Hummers method) was mixed with 50 parts by weight of N,N-dimethylformamide (Aldrich) and ultrasonically dispersed at 25°C for 60 min at an ultrasonic frequency of 30 kHz. The resulting mixture was placed in a nitrogen atmosphere and 26 parts by weight of 3-isocyanate-propyltrimethoxysilane (Yishun Chemical) were added. The reaction system was heated to 80°C and stirred at 1200 r / min for 25 h. After the reaction system cooled naturally to room temperature, the resulting black suspension was centrifuged and the lower precipitate was removed. The lower precipitate was then repeatedly washed with dichloromethane (Jinan Xichuan) to obtain modified graphene oxide.

[0215] S2, Preparation process of polyurea anti-corrosion coating component A

[0216] Polyoxypropylene ether glycol PPG-1500 was added to a reactor and heated to 115°C under a pressure of -0.11 MPa, and maintained for 2.5 h for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 60°C, hexamethylene diisocyanate, p-phenylenemethylene diisocyanate, DER-321, aluminum tripolyphosphate, 2-dimethylaminoethyl acetate, and the modified graphene oxide prepared in step S1 were added according to the aforementioned ratio. The temperature was then raised to 88°C and stirred for 2 h. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component A for later use.

[0217] S3, Preparation process of polyurea anti-corrosion coating component B

[0218] In a reaction vessel, polyetheramine T-403 and N,N'-dialkylphenylenediamine were added according to the aforementioned ratio. Under a pressure of -0.1 MPa, the mixture was stirred and heated to 95°C and maintained for 2 hours for dehydration. The reaction system was then adjusted to a normal pressure and nitrogen environment. After the temperature was lowered to 55°C, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, UV-P, and KH-550 were added according to the aforementioned ratio. The temperature was then raised to 70°C and stirred for 2 hours. After the reaction was completed, the reaction system was cooled to 30°C and filtered to obtain polyurea anticorrosive coating component B for later use.

[0219] S4. Preparation process of polyurea anti-corrosion coating

[0220] First, acetone and ethanol are used to remove grease from the surface of the metal substrate. Then, rust removal is performed by spraying to treat the surface of the metal substrate to Sa 2.5 grade. Using a special spraying device for polyurea coating, polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B are mixed at a weight ratio of 1.15:1 and sprayed onto the surface of the metal substrate. The spraying temperature is set at 80℃ and the spraying pressure is 16MPa. After curing at 20℃ for 6 days, the polyurea anti-corrosion coating can be obtained.

[0221] Comparative Example 1

[0222] The method of Example 1 was implemented, except that NPEF-170 was not added in step S2, that is, bisphenol F epoxy resin was not added in the process of preparing polyurea anti-corrosion coating component A.

[0223] Comparative Example 2

[0224] The method of Example 1 is implemented, except that aluminum tripolyphosphate is not added in step S2, that is, no stabilizing rust-reducing agent is added in the process of preparing polyurea anti-corrosion coating component A.

[0225] Comparative Example 3

[0226] The method of Example 1 was implemented, except that NPEF-170 and aluminum tripolyphosphate were not added in step S2, that is, bisphenol F epoxy resin and stabilizing rust-reducing agent were not added in the process of preparing polyurea anti-corrosion coating component A.

[0227] Comparative Example 4

[0228] The method of Example 1 is implemented, except that step S1 is not performed and modified graphene oxide is not added in step S2, that is, modified graphene oxide is not added in the process of preparing polyurea anticorrosive coating component A.

[0229] Comparative Example 5

[0230] The method of Example 1 was implemented, except that step S1 was omitted and graphene oxide (Xianfeng Nano) was directly added in step S2. That is, unmodified graphene oxide was added during the preparation of polyurea anticorrosive coating component A.

[0231] Test Example 1

[0232] The FTIR spectra of graphene oxide and modified graphene oxide described in step S1 of Example 1 were measured using an ATR-FTIR spectrometer (ThermoFisher), with the scanning range set to 400-4000 cm⁻¹. -1 .

[0233] Depend on Figure 1 Infrared spectra show that graphene oxide has a wavelength of 3428 cm⁻¹. -1 1730cm -1 and 1655cm -1 Characteristic peaks of stretching vibrations of OH, C=O, and C=C were observed at 3422 cm⁻¹, respectively. These three peaks also appeared at 3422 cm⁻¹ in the modified graphene oxide. -1 1735cm -1 and 1655cm -1 Location. Furthermore, modified graphene oxide 2258 cm⁻¹ -1 and 1735cm -1 The presence of absorption peaks corresponding to NC=O and CN=C at the surface of graphene oxide modified with 3-isocyanate-propyltriethoxysilane proves that isocyanate groups and imine bonds have been successfully grafted onto the surface of the graphene oxide.

[0234] Test Example 2

[0235] The mechanical properties and corrosion resistance of the polyurea anti-corrosion coatings prepared in Examples 1-10 and Comparative Examples 1-5 were tested, and the test results are shown in Tables 1 and 2. The mechanical property testing methods were as follows: adhesion was tested according to the method described in standard GB / T5210-2006; tensile strength and elongation at break were tested according to the method described in standard GB / T 2567-2021; and hardness was tested according to the method described in standard GB / T 2411-2008. The corrosion resistance testing methods were as follows: resistance to neutral salt spray was tested according to the method described in standard GB / T1771-2007; and resistance to 3wt% NaCl solution, 5wt% NaOH solution, and 5wt% H2SO4 solution was tested according to the method described in standard GB / T9274-1988.

[0236] Table 1

[0237]

[0238] As can be seen from Table 1, the polyurea anti-corrosion coating prepared in the embodiments of the present invention has better adhesion, tensile strength, elongation at break and hardness than the comparative example.

[0239] Table 2

[0240]

[0241]

[0242] As can be seen from Table 2, the polyurea anti-corrosion coating prepared in the embodiments of the present invention has significantly better corrosion resistance than the comparative example in neutral salt spray, 3wt% NaCl solution, 5wt% NaOH solution and 5wt% H2SO4 solution.

[0243] From the test data in Tables 1 and 2 above, we can see that:

[0244] (1) By comparing the test results of Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3, it was found that the addition of bisphenol F epoxy resin and stabilized rust-removing agent in the preparation of polyurea anti-corrosion coating component A of the present invention can improve the adhesion of the coating by interacting with the surface of the metal substrate; at the same time, it can extend the service life of the prepared coating in the corrosive environment and avoid failure phenomena such as detachment from the substrate and loss of adhesion during long-term corrosion.

[0245] (2) By comparing the test results of Example 1, Comparative Example 4, and Comparative Example 5, it was found that adding the modified graphene oxide during the preparation of component A of the polyurea anticorrosive coating in this invention helps to improve the tensile strength, elongation at break, hardness, and corrosion resistance of the coating. This is mainly due to the excellent impermeability, mechanical strength, and stability of the two-dimensional layered graphene structure. In addition, since the uniform dispersion of graphene oxide in the coating is an important prerequisite for the full realization of its various properties, the compatibility and dispersibility of the modified graphene oxide with the coating are significantly improved, resulting in a more significant reinforcing effect on the coating performance.

[0246] Test Example 3

[0247] The method described in Examples 1-10 and Comparative Examples 1-5 is implemented, except that the surface pretreatment of the metal substrate in step S4 is performed as follows:

[0248] Pretreatment of metal substrate surface: The metal substrate is placed in a 3.5wt% NaCl solution and immersed in corrosion at 25℃ for 14 days to make the surface of the metal substrate rusted. After removing the rusted metal substrate, the surface grease is removed with acetone and ethanol, and then it is simply polished with 200-grit and 400-grit sandpaper in turn.

[0249] The adhesion between each polyurea anti-corrosion coating and the rusted metal substrate was tested according to the method described in standard GB / T 5210-2006, and the results are shown in Table 3.

[0250] Table 3

[0251] Adhesion / MPa Example 1 15.7 Example 2 14.9 Example 3 15.3 Example 4 15.2 Example 5 15.0 Example 6 15.1 Example 7 15.5 Example 8 15.7 Example 9 15.2 Example 10 15.1 Comparative Example 1 13.5 Comparative Example 2 7.6 Comparative Example 3 6.2 Comparative Example 4 13.4 Comparative Example 5 12.9

[0252] As shown in Table 3, the polyurea anti-corrosion coating of this invention still exhibits good adhesion to rusted metal surfaces. The stabilizing rust-reversing agent is the main functional filler, capable of decomposing at the interface to generate phosphate and chromate ions, which, in turn, react with metal rust to form a passivation layer of heteropolyacid complexes with strong adhesion. This enhances the bond between the polyurea coating and the base metal, allowing it to be applied to rusted metal equipment surfaces.

[0253] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A polyurea anticorrosive coating composition, characterized in that, This polyurea anti-corrosion coating composition contains polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B, which are stored independently. The polyurea anti-corrosion coating component A is prepared from raw materials containing aliphatic diisocyanate, aromatic diisocyanate, polyether polyol, bisphenol F type epoxy resin, stabilized rust-reducing agent, ester viscosity reducer and modified graphene oxide, wherein the modified graphene oxide is obtained by modifying graphene oxide with isocyanate-based silane. The polyurea anticorrosive coating component B is prepared from raw materials containing polyether polyamine, terminal amino chain extender, light stabilizer hindered amine, ultraviolet absorber and silane coupling agent; The stabilized rust-removing agent is selected from one or more of zinc phosphate, zinc chromate, and aluminum tripolyphosphate.

2. The polyurea anticorrosive coating composition according to claim 1, characterized in that, A method for preparing modified graphene oxide, the method comprising the following steps: (1) Mix graphene oxide with an organic solvent and sonicate; (2) Under an inert atmosphere, the solution obtained in step (1) is mixed with isocyanate-based silane and reacted, and the solid and liquid are separated to obtain modified graphene oxide.

3. The polyurea anticorrosive coating composition according to claim 2, characterized in that, In step (1), the weight ratio of the graphene oxide to the organic solvent is 1:40~105.

4. The polyurea anticorrosive coating composition according to claim 2, characterized in that, In step (1), the organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide and N,N-diethylformamide.

5. The polyurea anti-corrosion coating composition according to claim 2 or 3, characterized in that, In step (1), the conditions for ultrasound include: ultrasound temperature of 15~30℃, ultrasound time of 30~60min, and ultrasound frequency of 20-35kHz.

6. The polyurea anti-corrosion coating composition according to claim 1 or 2, characterized in that, The isocyanate-based silane is 3-isocyanate-propyltriethoxysilane and / or 3-isocyanate-propyltrimethoxysilane.

7. The polyurea anti-corrosion coating composition according to claim 1 or 2, characterized in that, The weight ratio of the graphene oxide to the isocyanate-based silane is 1:20~50.

8. The polyurea anticorrosive coating composition according to claim 7, characterized in that, The weight ratio of the graphene oxide to the isocyanate-based silane is 1:25~40.

9. The polyurea anticorrosive coating composition according to claim 2, characterized in that, In step (2), the reaction conditions include: a reaction temperature of 60~100℃ and a reaction time of 12~48h.

10. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The weight ratio of the aliphatic diisocyanate, the aromatic diisocyanate, the polyether polyol, the bisphenol F epoxy resin, the stabilized rust-reducing agent, the ester viscosity reducer, and the modified graphene oxide is 30:28~44:24~38:5~10:6~15:1~2:0.5~2.

11. The polyurea anticorrosive coating composition according to claim 1 or 10, characterized in that, The weight ratio of the polyether polyamine, the terminal amino chain extender, the light stabilizer hindered amine, the ultraviolet absorber, and the silane coupling agent is 55:25~40:1~3:1~2:10~20.

12. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The aliphatic diisocyanate is selected from one or more of hexamethylene diisocyanate, hexamethylene diisocyanate trimer, methyl formate pentamethylene diisocyanate, and 2,2,4-trimethylhexane diisocyanate.

13. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The aromatic diisocyanate is selected from one or more of 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, p-phenylene diisocyanate, methylcyclohexyl diisocyanate, p-phenylenedimethylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 3,3'-dimethoxy-4,4′-diphenyl diisocyanate, and hydrogenated phenylmethane diisocyanate.

14. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The molecular weight of the polyether polyol is 200-3000.

15. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The polyether polyol is selected from one or more of polyoxypropylene ether diol, polytetrahydrofuran ether polyol, polyoxypropylene-ethylene oxide diol, and tetrahydrofuran-propylene oxide copolydiol.

16. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The epoxy equivalent of the bisphenol F type epoxy resin is 140~200 g / eq.

17. The polyurea anticorrosive coating composition according to claim 16, characterized in that, The epoxy equivalent of the bisphenol F type epoxy resin is 150~190 g / eq.

18. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The ester-based viscosity reducer is selected from one or more of dioctyl phthalate, dibutyl phthalate, ethyl carbonate, propylene carbonate, propanesulfonate lactone, 2-dimethylaminoethyl acetate, 2-chloroethyl ester, and dimethylaminoethyl acrylate.

19. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The molecular weight of the polyether polyamine is 100~3000.

20. The polyurea anti-corrosion coating composition according to claim 19, characterized in that, The molecular weight of the polyether polyamine is 200-2000.

21. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The terminal amino chain extender is selected from one or more of dimethylthiotoluenediamine, N,N'-disec-butyl-p-phenylenediamine, N,N'-dialkylphenylenediamine, N,N'-dialkylmethyldiamine, bis(p-aminobenzoic acid) propylene glycol ester, diethyltoluenediamine, and methyldiethanolamine.

22. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The light stabilizer steric amine is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and / or 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

23. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The ultraviolet absorber is selected from one or more of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole and 2-hydroxy-4-n-octylbenzophenone.

24. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The silane coupling agent is selected from one or more of γ-diethylenetriaminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, and γ-aminoethylaminopropyltrimethoxysilane.

25. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The preparation method of component A of the polyurea anticorrosive coating includes: S1. Dehydrate the polyether polyol; S2. Under normal pressure and an inert atmosphere, the product obtained in step S1 is mixed with aliphatic diisocyanate, aromatic diisocyanate, bisphenol F epoxy resin, stabilized rust-reducing agent, ester viscosity reducer and modified graphene oxide for reaction.

26. The polyurea anti-corrosion coating composition according to claim 25, characterized in that, In step S1, the dehydration treatment conditions include: pressure of -0.05 to -0.15 MPa, temperature of 100 to 120°C, and time of 2 to 3 hours.

27. The polyurea anti-corrosion coating composition according to claim 26, characterized in that, In step S2, the reaction conditions include: a reaction temperature of 70~100℃ and a reaction time of 1~6h.

28. The polyurea anticorrosive coating composition according to claim 27, characterized in that, The reaction conditions include a reaction temperature of 80~90℃.

29. The polyurea anti-corrosion coating composition according to claim 27, characterized in that, The reaction conditions include a reaction time of 2-4 hours.

30. The polyurea anticorrosive coating composition according to claim 1, characterized in that, The preparation method of component B of the polyurea anticorrosive coating includes: 1) Mix polyether polyamine and terminal amino chain extender and dehydrate them; 2) Under normal pressure and an inert atmosphere, the product obtained in step 1) is mixed with the light stabilizer sterically hindered amine, the ultraviolet absorber and the silane coupling agent and reacted.

31. The polyurea anticorrosive coating composition according to claim 30, characterized in that, In step 1), the dehydration treatment conditions include: pressure of -0.05 to -0.15 MPa, temperature of 90 to 110°C, and time of 2 to 3 hours.

32. The polyurea anti-corrosion coating composition according to claim 30 or 31, characterized in that, In step 2), the reaction conditions include: a reaction temperature of 50~80℃ and a reaction time of 0.5~4h.

33. The polyurea anti-corrosion coating composition according to claim 32, characterized in that, In step 2), the reaction conditions include a reaction temperature of 60~75℃.

34. The polyurea anticorrosive coating composition according to claim 32, characterized in that, In step 2), the reaction conditions include a reaction time of 1 to 2 hours.

35. A method for preparing a polyurea anti-corrosion coating using the polyurea anti-corrosion coating composition according to any one of claims 1-34, characterized in that, The method includes: mixing polyurea anti-corrosion coating component A and polyurea anti-corrosion coating component B, spraying the mixture onto the surface of a metal substrate, and curing it to obtain a polyurea anti-corrosion coating.

36. The method according to claim 35, characterized in that, The weight ratio of polyurea anticorrosive coating component A to polyurea anticorrosive coating component B is 1-1.2:

1.

37. The method according to claim 36, characterized in that, The weight ratio of polyurea anticorrosive coating component A to polyurea anticorrosive coating component B is 1.05-1.15:

1.

38. The method according to claim 35 or 36, characterized in that, The spraying conditions include: a spraying temperature of 60~80℃ and a spraying pressure of 14~16MPa.

39. The method according to claim 35, characterized in that, The conditions for maintenance include: a maintenance temperature of 15~30℃ and a maintenance time of 5~9 days.

40. The method according to claim 35, characterized in that, The metal substrate is carbon steel material for the outer wall of the storage tank.

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