Oily graphene anticorrosive paint as well as preparation method and application thereof

Abstract

The invention discloses an oily graphene anti-corrosion coating as well as a preparation method and application thereof, and belongs to the crossing field of anti-corrosion coatings and nano material dispersion technologies. The oily graphene anticorrosive paint comprises the following raw materials in percentage by mass: 20%-70% of an oily resin matrix, 0.1%-3% of graphene, 5%-25% of a dispersing agent, 15%-40% of a solvent and 5%-60% of a curing agent, wherein the oleoresin matrix is one of bisphenol A epoxy resin, fluorocarbon resin and phenolic resin. The graphene slurry prepared by the invention has super-long storage stability; the room-temperature storage period of the slurry is more than or equal to 30 days (particle suspension rate gt; and the salt spray resistance life of the modified coating is more than or equal to 4900 hours, and is obviously prolonged compared with that of the traditional oil paint (3000 hours). Modifying a coating charge transfer resistance (Rct) gt; and 6.0 * 10 < 8 > omega.cm < 2 >. The coating realizes double breakthrough in cost and environmental protection property: the addition amount of graphene is 0.1%-3%, and VOC emission is controlled to be 50-80 g / L. The coating can be applied to protection of energy infrastructures, ocean engineering and heavy equipment, industrial building structures and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the cross field of anticorrosive coatings and nanomaterial dispersion technology, and specifically relates to an oily graphene anticorrosive coating and a preparation method and application thereof. BACKGROUND

[0002] I. Performance bottleneck of traditional oily anticorrosive coatings

[0003] Existing oily anticorrosive coatings (such as epoxy resin and polyurethane systems) generally rely on zinc powder and phosphate to build a protective system, and their salt spray resistance (usually ≤3000 hours, GB / T 10125-2021 standard) cannot meet the demand for long-term protection in extreme corrosion scenarios such as marine engineering (such as offshore wind tower, drilling platform) and petrochemical industry (such as oil and gas pipeline, refining and storage tank).

[0004] For example, in a certain offshore wind power project, traditional epoxy zinc-rich primer appeared local corrosion after 18 months of service in marine atmospheric area, resulting in an increase of more than 40% in maintenance cost, and frequent maintenance seriously affected the equipment operation efficiency.

[0005] In addition, lead and chromium phosphate corrosion inhibitors widely used in traditional anticorrosive coating systems not only have heavy metal pollution risk, but also conflict with the VOCs limit requirement (≤420g / L) in the EU REACH regulation and China's "Comprehensive Management Scheme for Volatile Organic Compounds in Key Industries".

[0006] II. Environmental advantages and performance shortcomings of water-based coatings

[0007] Water-based coatings (such as two-component epoxy systems) achieve VOCs emission reduction (VOCs content ≤150g / L) and environmental upgrading through water-based solvents, but their protective performance has significant defects: their chemical medium corrosion resistance (such as 10% H2SO4 solution immersion ≤72 hours) and mechanical strength (cross-hatch adhesion ≤3) are significantly inferior to oily systems, and they are prone to swelling and peeling of the coating in oily media (such as crude oil and diesel), resulting in failure of the protective performance.

[0008] Therefore, developing oily anticorrosive coatings with high performance and low environmental load has become a key breakthrough to solve the "performance-environmental protection" contradiction in the heavy-duty corrosion field.

[0009] III. Potential and technical challenges of graphene coatings

[0010] Graphene is considered a revolutionary material for the next generation of anticorrosive coatings due to its single-atom layer thickness (about 0.34nm), ultra-high specific surface area (2630m 2 / g) and labyrinth-like barrier effect. However, the application of graphene in oily systems still faces major technical challenges:

[0011] (1)Sheet aggregation problem: due to the strong van der Waals force (binding energy ≈ 2 eV / nm 2 ) and π-π conjugation between graphene sheets, lateral stacking and longitudinal aggregation (aggregate size > 5 μm) easily occur in oily systems.

[0012] (2) Dispersion stability defect: existing dispersion techniques are prone to failure due to weak electrostatic repulsion and steric hindrance, resulting in uneven dispersion of graphene in oily systems. The graphene slurry has a suspension rate of <60% after 30 days of storage, and cannot form a long-range ordered continuous protective network (electron microscopy observation shows that the graphene coverage is <60%).

[0013] Four, breakthrough and limitations of graphene-fluorocarbon composite coating

[0014] For example, the "graphene-fluorocarbon composite coating" developed by AVIC New Materials, the technology embeds graphene into fluorocarbon resin matrix through chemical vapor deposition (CVD) method, forming a three-dimensional interpenetrating network structure, making the coating salt spray resistance life break through 10000 hours (ISO 12944 standard), and successfully applied to the steel structure protection engineering of Hong Kong-Zhuhai-Macao Bridge, the corrosion resistance life is 2.3 times higher than that of traditional fluorocarbon coating.

[0015] However, this technology still has the following limitations:

[0016] Environmental risk: use of xylene solvent (VOC exceeds standard risk) and zinc powder filler (metal residue) in the preparation process;

[0017] Cost constraints: graphene CVD process and precise control of composite materials result in a 40%-60% higher cost than conventional coatings;

[0018] Limited application scenarios: current cost and technical complexity make it more suitable for major infrastructure (such as cross-sea bridges), and it is still difficult to be widely promoted to regular marine engineering and petrochemical industry. Summary of the invention

[0019] In view of the defects in the prior art, the present application provides an oily graphene anticorrosive coating, its preparation method and application.

[0020] The technical solution adopted by the present application is:

[0021] In a first aspect, the present application provides an oily graphene anticorrosive coating, which comprises the following raw materials in mass percentage: oily resin matrix 20%-70%, graphene 0.1%-3%, dispersant 5-25%, solvent 15-40%, curing agent 5%-60%;

[0022] Among them, the oily resin matrix is one of bisphenol A type epoxy resin, fluorocarbon resin and phenolic resin.

[0023] In some embodiments, the solvent is one of N-methyl pyrrolidone (NMP), γ-butyrolactone (GBL), acetone, methyl ethyl ketone (MEK), xylene, ethyl acetate, ethylene glycol butyl ether (BCS), ethyl lactate, terpineol.

[0024] In some embodiments, the dispersant is one of cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium chloride (DTAC), dodecylamine hydrochloride (DAAHCl), N-methyldodecylamine hydrochloride, cetylpyridinium chloride (CPC), benzylpyridinium chloride (BPC), 1-hydroxyethyl-2-alkylimidazoline, N-alkylmorpholine oxide, didodecyldimethylammonium dibromide, dioctadecyldimethylammonium chloride (DODMAC), lauroyl lysine hydrochloride, glucosyltrimethylammonium chloride, a complex dispersant.

[0025] In some embodiments, the complex dispersant is a mixture of a quaternary ammonium salt dispersant and a gemini quaternary ammonium salt dispersant, wherein the mass ratio of the quaternary ammonium salt dispersant to the gemini quaternary ammonium salt dispersant is (9:1) to (6:4); the quaternary ammonium salt dispersant is one of cetyltrimethylammonium bromide (CTAB) and dodecyltrimethylammonium chloride (DTAC); and the gemini quaternary ammonium salt dispersant is one of didodecyldimethylammonium dibromide and dioctadecyldimethylammonium chloride (DODMAC).

[0026] In some embodiments, the bisphenol A type epoxy resin is one of E-51, E-44, and E-35.

[0027] In some embodiments, the fluorocarbon resin is one of polyvinylidene fluoride resin (PVDF), fluorinated ethylene vinyl ether copolymer resin (FEVE), polytetrafluoroethylene resin (PTFE), ethylene-tetrafluoroethylene copolymer resin (ETFE), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer resin (THV).

[0028] In some embodiments, the phenolic resin is a thermoplastic resin obtained by condensation polymerization of phenol (or substituted phenol) and formaldehyde under the catalysis of an acid or a base.

[0029] In some embodiments, the curing agent is one of diethylenetriamine, isocyanate, p-toluenesulfonic acid.

[0030] In some embodiments, when the oily resin matrix is selected from a bisphenol A type epoxy resin, the curing agent is diethylenetriamine.

[0031] In some embodiments, when the oily resin matrix is selected from a fluorocarbon resin, the curing agent is diethylenetriamine.

[0032] And / or, when the oil-based resin matrix is selected from phenolic resin, the curing agent is p-toluenesulfonic acid.

[0033] In some embodiments, the oil-based graphene anticorrosive coating comprises the following raw materials in mass percentage: 20-60% of oil-based resin matrix, 0.1-2.5% of graphene, 5-20% of dispersant, 15-30% of solvent, and 10-45% of curing agent.

[0034] In some embodiments, the preparation of the oil-based graphene anticorrosive coating comprises the following steps: first, adding the dispersant into the solvent to obtain a dispersant solution, then adding the graphene into the dispersant solution, stirring and dispersing, and then ultrasonic treatment to obtain a graphene-containing slurry; adding the graphene-containing slurry into the oil-based resin matrix to obtain component one of the oil-based graphene anticorrosive coating.

[0035] The curing agent is component two of the oil-based graphene anticorrosive coating.

[0036] In use, component one and component two are mixed to obtain the oil-based graphene anticorrosive coating, which is coated on the surface of a substrate to form a coating after drying and curing.

[0037] In a second aspect, the application provides a preparation method of the oil-based graphene anticorrosive coating, comprising the following steps:

[0038] S1: weighing the raw materials according to any one of the above descriptions;

[0039] S2: adding the dispersant into the solvent, stirring at room temperature until the dispersant is fully dissolved to obtain solution A;

[0040] S3: adding the graphene into solution A, stirring at a speed of 100-500 rpm at room temperature for 10-30 min, and ultrasonic treatment for 30-120 min to obtain slurry B;

[0041] S4: adding slurry B into the oil-based resin matrix, stirring at a speed of 100-500 rpm at room temperature for 10-120 min to obtain slurry C;

[0042] S5: adding the curing agent into slurry C, stirring until uniform to obtain the oil-based graphene anticorrosive coating.

[0043] In some embodiments, the ultrasonic frequency of the ultrasonic dispersion is 20-30 kHz, and the power is 200-2500 W.

[0044] In a third aspect, the application provides a graphene anticorrosive coating, which is obtained by coating the oil-based graphene anticorrosive coating prepared by the above preparation method on the surface of a substrate and drying and curing; the substrate includes a metal substrate and a non-metal substrate.

[0045] In some embodiments, the coating with a thickness of 60±5 μm has a salt spray resistance life ≥4900h (according to GB / T10125-2021 Neutral Salt Spray Test in Artificial Atmosphere Corrosion Test Salt Spray Test, 5% NaCl, 35±2℃).

[0046] In some embodiments, the coating with a thickness of 60±5 μm has a charge transfer resistance (R ct )>6.0×10 8 Ω·cm 2 (according to EIS electrochemical impedance spectroscopy test, frequency range 100 kHz-10 mHz, amplitude 10 mV).

[0047] In a fourth aspect, the application provides the use of the above-mentioned oil-based graphene anticorrosive coating in any one of the following, including:

[0048] (a1) preparing a surface coating of energy infrastructure, including protective coating of oil and gas storage and transportation equipment, new energy equipment (wind tower, wind turbine blade leading edge, photovoltaic support) and energy storage device (lithium battery shell, energy storage container) ;

[0049] (a2) preparing a surface coating of marine engineering and heavy equipment, including structural protective coating of cross-sea bridge, port facility, ship and offshore platform;

[0050] (a3) preparing a surface coating of industrial building structure, including anticorrosive coating of chemical equipment, industrial pipeline, industrial building and color steel plate.

[0051] Compared with the prior art, the application has the following beneficial effects:

[0052] (1) The preparation method provided by the application has super-long storage stability of graphene slurry: slurry room temperature storage period ≥30 days (particle suspension rate >95%), which is much better than the traditional dispersion system (30 days sedimentation rate >40%).

[0053] (2) The oil-based anticorrosive coating prepared by the application has extreme environmental tolerance, and the modified coating has a salt spray resistance life of ≥4900 hours, which is significantly improved compared with the traditional oil-based coating (3000 hours). The charge transfer resistance (R ct )>6.0×10 8 Ω·cm 2 .

[0054] (3) The graphene modified paint prepared in the present application realizes the breakthrough of cost and environmental protection: the graphene addition amount is 0.1% to 3%, the cost is only increased by 10-15% compared with the traditional oil-based paint, which is much lower than the similar graphene modified paint (40%-60% higher than the traditional oil-based paint). The VOC emission of the graphene modified paint prepared in the present application is controlled in 50-80 g / L, which is better than the limit value of 150 g / L in the national standard “Technical Requirements for Low Volatile Organic Compound Content Paint Products” (GB / T 38597-2020).

[0055] (4) The paint prepared in the present application can be applied to the protection of energy infrastructure, marine engineering and heavy equipment, industrial building structure, etc. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 The dispersion stability comparison chart of the graphene dispersion slurry (slurry C) of the present application examples 1-6 within 30 days.

[0057] Figure 2 The salt spray resistance life and charge transfer resistance value R of the coating of the present application examples 1-6 ct Comparison chart.

[0058] Figure 3 The salt spray resistance life and charge transfer resistance value R of the coating of the present application examples 7-10 ct Comparison chart. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical scheme and advantages of the present application examples clearer, the technical scheme in the present application examples is described clearly and completely. Obviously, the described examples are only part of the present application, not all. Therefore, the following detailed description of the examples of the present application is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the examples of the present application, all other examples obtained by those skilled in the art without creative labor are within the scope of the present application.

[0060] In view of the bottleneck of the prior art, the present application innovatively uses a cationic surfactant as a graphene dispersant, realizes the efficient and stable dispersion of graphene in an oil-based system (storage period > 30 days) through the dual mechanism of electrostatic adsorption and directional arrangement of hydrophobic chain segments, and has excellent compatibility with the oil-based matrix and excellent corrosion protection performance of the paint (salt spray resistance life ≥ 4900 hours). The present application solves the dispersion problem of graphene in an oil-based system through the optimization and compounding of cationic surfactants, provides a long-term corrosion protection solution for marine engineering (such as cross-sea bridge steel piles), petrochemical pipelines (such as acidic oil and gas gathering and transportation pipelines), etc., and has advanced technology and industrialization feasibility.

[0061] The raw materials in the examples include:

[0062] N-Methylpyrrolidone (NMP), chemical formula C5H9NO, CAS Registry Number 872-50-4.

[0063] Gamma-Butyrolactone (GBL), chemical formula: C4H6O2, CAS Number: 96-48-0.

[0064] 2-Butanone (MEK), chemical formula C4H8O, CAS Registry Number 78-93-3.

[0065] 2-Butoxyethanol (BCE), chemical formula C6H 14 O2, CAS Registry Number 111-76-2.

[0066] Ethyl lactate, also known as 2-hydroxypropionic acid ethyl ester, chemical formula C5H 10 O3, CAS Registry Number 97-64-3.

[0067] Terpineol, molecular formula C 10 H 18 O.

[0068] Hexadecyl trimethyl ammonium Bromide (CTAB), chemical formula C 19 H 42 BrN, CAS Registry Number 57-09-0.

[0069] Dodecyl trimethyl ammonium chloride (DTAC), chemical formula C 15 H 34 ClN, CAS Registry Number 112-00-5.

[0070] Dodecylamine hydrochloride (DAAHCl), also known as dodecylamine hydrochloride, chemical formula C 12 H 28 ClN, CAS Registry Number 929-73-7.

[0071] N-Methyldodecylamine Hydrochloride is the hydrochloride form of N-dodecylmethylamine, chemical formula C 13 H 29N·HCl.

[0072] Cetylpyridinium chloride (CPC), also known as Cetylpyridinium Chloride Monohydrate (CPC), has the molecular formula C 21 H 38 ClN·H2O, CAS No. 6004-24-6.

[0073] Benzylpyridinium chloride (BPC), also known as 1-Benzylpyridinium Chloride, has the molecular formula C 12 H 12 ClN, CAS No. 2876-13-3.

[0074] 1-Hydroxyethyl-2-alkyl imidazoline consists of an imidazoline ring, a hydroxyethyl hydrophilic group, and a long-chain alkyl hydrophobic tail, where the alkyl chain is typically C8-C 18 , with CAS No. varying with the alkyl chain.

[0075] N-Alkyl morpholine oxide has the molecular formula C5H 11 NO, CAS No. 109-02-4.

[0076] Didodecyldimethylammonium bromide has the molecular formula C 26 H 56 BrN, CAS No. 3282-73-3.

[0077] Dimethyl distearylammonium chloride (DODMAC) has the chemical formula (C 18 H 37 )2(CH3)2NCl, CAS No. 107-64-2.

[0078] Lauroyl lysine hydrochloride is the hydrochloride form of lauroyl lysine, whose parent compound is N-lauroyl-L-lysine (CAS No. 52315-75-0).

[0079] Glucosyltrimetrylammonium chloride is formed by combining a glucoside hydrophilic head group with a quaternary ammonium salt, with an alkyl chain of C8-C 14 (usually C 12 , i.e., lauryl), CAS No. 93925-36-1 (C12 -C 14 alkyl chain mixture).

[0080] Polyvinylidene Fluoride Resin (PVDF), also called polyvinylidene difluoride (PVDF), chemical formula (CH2CF2) n , CAS No. 24937-79-9, is a highly non-reactive thermoplastic fluoropolymer.

[0081] Fluoroethylene Vinyl Ether Copolymer Resin (FEVE), also called fluoroalkene alkyl ethyl ether, is a copolymer of fluoroalkene-vinyl ether or ester.

[0082] Polytetrafluoroethylene Resin (PTFE), a high molecular polymer polymerized with polytetrafluoroethylene as a monomer, chemical formula (C2F4) n , CAS No. 9002-84-0.

[0083] Ethylene-tetra-fluoro-ethylene Copolymer Resin (ETFE), (CH2CH2) x (CF2CF2) y , CAS No. 25038-71-5.

[0084] Tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer resin (THV) is a high-performance fluoroplastic, which is copolymerized by tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and vinylidene fluoride (VDF) three monomers. Molecular formula is (C2F4) x -(C3F6) y -(C2H2F2) z , CAS No. 25190-89-0.

[0085] Phenolic resin, molecular formula C7H8O2; CAS No. 9003-35-4.

[0086] Fluorocarbon resin: a high molecular compound formed by polymerization of fluorine-containing olefin monomers such as tetrafluoroethylene and chlorotrifluoroethylene.

[0087] The above raw materials are commercially available products.

[0088] In the examples, the ultrasonic dispersion has an ultrasonic frequency of 20-30 kHz and a power of 200-2500 W.

[0089] The experimental methods used in the following specific examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following specific examples are commercially available or prepared according to conventional methods in the art unless otherwise specified.

[0090] Example 1:

[0091] (1) 14 g of DTAC (as a dispersant) was added to 30 g of γ-butyrolactone (abbreviated as GBL, as a solvent), and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0092] (2) 0.11 g of graphene was added to solution A, and after stirring at 200 rpm for 30 min at room temperature, ultrasonic treatment was performed for 120 min to obtain slurry B;

[0093] (3) Slurry B was added to 50 g of an E-44 epoxy resin matrix, and after stirring at 200 rpm for 120 min at room temperature, slurry C was obtained;

[0094] (4) 15 g of diethylenetriamine (as a curing agent) was added to slurry C, and after stirring, an oil-based graphene anticorrosive coating was obtained.

[0095] Example 2:

[0096] (1) 14 g of DTAC (as a dispersant) was added to 30 g of GBL solvent, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0097] (2) 1.11 g of graphene was added to solution A, and after stirring at 200 rpm for 30 min at room temperature, ultrasonic treatment was performed for 120 min to obtain slurry B;

[0098] (3) Slurry B was added to 50 g of an E-44 epoxy resin matrix, and after stirring at 200 rpm for 120 min at room temperature, slurry C was obtained;

[0099] (4) 15 g of diethylenetriamine (as a curing agent) was added to slurry C, and after stirring, an oil-based graphene anticorrosive coating was obtained.

[0100] Example 3:

[0101] (1) 14 g of DTAC (as a dispersant) was added to 30 g of GBL solvent, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0102] (2) 1.66 g of graphene was added to solution A, and after stirring at 200 rpm for 30 min at room temperature, ultrasonic treatment was performed for 120 min to obtain slurry B;

[0103] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C is obtained;

[0104] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring evenly, oil-based graphene anticorrosive coating is obtained.

[0105] Example 4:

[0106] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, after stirring at room temperature until the dispersant is completely dissolved, solution A is obtained;

[0107] (2) To solution A, add 2.23 g of graphene, after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic for 120 min, slurry B is obtained;

[0108] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C is obtained;

[0109] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring evenly, oil-based graphene anticorrosive coating is obtained.

[0110] Example 5:

[0111] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, after stirring at room temperature until the dispersant is completely dissolved, solution A is obtained;

[0112] (2) To solution A, add 2.8 g of graphene, after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic for 120 min, slurry B is obtained;

[0113] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C is obtained;

[0114] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring evenly, oil-based graphene anticorrosive coating is obtained.

[0115] Example 6:

[0116] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, after stirring at room temperature until the dispersant is completely dissolved, solution A is obtained;

[0117] (2) To solution A, add 3.38 g of graphene, after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic for 120 min, slurry B is obtained;

[0118] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C is obtained;

[0119] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring evenly, oil-based graphene anticorrosive coating is obtained.

[0120] Example 7:

[0121] (1) To 30 g of GBL solvent, add 12.6 g of DTAC and 1.4 g of DODMAC as dispersant, after stirring at room temperature until the dispersant is completely dissolved, solution A is obtained;

[0122] (2) To solution A, add 1.66 g of graphene, after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic for 120 min, slurry B is obtained;

[0123] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C is obtained;

[0124] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring evenly, oil-based graphene anticorrosive coating is obtained.

[0125] Example 8:

[0126] (1) To 30 g of GBL solvent, add 11.2 g of DTAC and 2.8 g of DODMAC as dispersant, after stirring at room temperature until the dispersant is completely dissolved, solution A is obtained;

[0127] (2) To solution A, add 1.66 g of graphene, after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic for 120 min, slurry B is obtained;

[0128] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C is obtained;

[0129] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring evenly, oil-based graphene anticorrosive coating is obtained.

[0130] Example 9:

[0131] (1) To 30 g of GBL solvent, add 9.8 g of DTAC and 4.2 g of DODMAC as dispersant, after stirring at room temperature until the dispersant is completely dissolved, solution A is obtained;

[0132] (2) To solution A, 1.66 g of graphene was added, stirred at 200 rpm for 30 min at room temperature, and then ultrasonicated for 120 min to obtain slurry B;

[0133] (3) To 50 g of E-44 epoxy resin matrix, slurry B was added, stirred at 200 rpm for 120 min at room temperature to obtain slurry C;

[0134] (4) To slurry C, 15 g of diethylene triamine curing agent was added, and after uniform stirring, an oil-based graphene anticorrosive coating was obtained.

[0135] Example 10:

[0136] (1) To 30 g of GBL solvent, 8.4 g of DTAC and 5.6 g of DODMAC were sequentially added as dispersants, and after stirring at room temperature until the dispersants were completely dissolved, solution A was obtained;

[0137] (2) To solution A, 1.66 g of graphene was added, stirred at 200 rpm for 30 min at room temperature, and then ultrasonicated for 120 min to obtain slurry B;

[0138] (3) To 50 g of E-44 epoxy resin matrix, slurry B was added, stirred at 200 rpm for 120 min at room temperature to obtain slurry C;

[0139] (4) To slurry C, 15 g of diethylene triamine curing agent was added, and after uniform stirring, an oil-based graphene anticorrosive coating was obtained.

[0140] Example 11:

[0141] (1) To 30 g of GBL solvent, 11.2 g of DTAC and 2.8 g of didodecyl dimethyl dibromide ammonium were sequentially added as dispersants, and after stirring at room temperature until the dispersants were completely dissolved, solution A was obtained;

[0142] (2) To solution A, 1.66 g of graphene was added, stirred at 200 rpm for 30 min at room temperature, and then ultrasonicated for 120 min to obtain slurry B;

[0143] (3) To 50 g of E-44 epoxy resin matrix, slurry B was added, stirred at 200 rpm for 120 min at room temperature to obtain slurry C;

[0144] (4) To slurry C, 15 g of diethylene triamine curing agent was added, and after uniform stirring, an oil-based graphene anticorrosive coating was obtained.

[0145] Example 12:

[0146] (1) 30 g of GBL solvent was sequentially added with 11.2 g of CTAB and 2.8 g of DODMAC as dispersants, and stirred at room temperature until the dispersants were completely dissolved to obtain solution A;

[0147] (2) 1.66 g of graphene was added to solution A, and stirred at room temperature at a speed of 200 rpm for 30 min, and then ultrasonically treated for 120 min to obtain slurry B;

[0148] (3) Slurry B was added to 50 g of an E-44 epoxy resin matrix, and stirred at room temperature at a speed of 200 rpm for 120 min to obtain slurry C;

[0149] (4) 15 g of diethylenetriamine curing agent was added to slurry C, and stirred uniformly to obtain an oil-based graphene anticorrosive coating.

[0150] Example 13:

[0151] (1) 30 g of GBL solvent was sequentially added with 11.2 g of CTAB and 2.8 g of dodecyl dimethyl dibromide as dispersants, and stirred at room temperature until the dispersants were completely dissolved to obtain solution A;

[0152] (2) 1.66 g of graphene was added to solution A, and stirred at room temperature at a speed of 200 rpm for 30 min, and then ultrasonically treated for 120 min to obtain slurry B;

[0153] (3) Slurry B was added to 50 g of an E-44 epoxy resin matrix, and stirred at room temperature at a speed of 200 rpm for 120 min to obtain slurry C;

[0154] (4) 15 g of diethylenetriamine curing agent was added to slurry C, and stirred uniformly to obtain an oil-based graphene anticorrosive coating.

[0155] Example 14:

[0156] (1) 30 g of GBL solvent was sequentially added with 11.2 g of CTAB and 2.8 g of dodecyl dimethyl dibromide as dispersants, and stirred at room temperature until the dispersants were completely dissolved to obtain solution A;

[0157] (2) 1.66 g of graphene was added to solution A, and stirred at room temperature at a speed of 200 rpm for 30 min, and then ultrasonically treated for 120 min to obtain slurry B;

[0158] (3) Slurry B was added to 50 g of an E-44 epoxy resin matrix, and stirred at room temperature at a speed of 200 rpm for 120 min to obtain slurry C;

[0159] (4) 15 g of diethylenetriamine curing agent was added to slurry C, and stirred uniformly to obtain an oil-based graphene anticorrosive coating.

[0160] Example 15:

[0161] (1) 14 g of DAAHCl dispersant was added to 30 g of GBL solvent, and stirred at room temperature until the dispersant was completely dissolved to obtain solution A;

[0162] (2) 1.66 g of graphene was added to solution A, and stirred at room temperature at a speed of 200 rpm for 30 min, and then ultrasonic treatment was performed for 120 min to obtain slurry B;

[0163] (3) Slurry B was added to 50 g of E-44 epoxy resin matrix, and stirred at room temperature at a speed of 200 rpm for 120 min to obtain slurry C;

[0164] (4) 15 g of diethylenetriamine curing agent was added to slurry C, and stirred uniformly to obtain an oily graphene anticorrosive coating.

[0165] Example 16:

[0166] (1) 14 g of N-methyl dodecylamine hydrochloride dispersant was added to 30 g of GBL solvent, and stirred at room temperature until the dispersant was completely dissolved to obtain solution A;

[0167] (2) 1.66 g of graphene was added to solution A, and stirred at room temperature at a speed of 200 rpm for 30 min, and then ultrasonic treatment was performed for 120 min to obtain slurry B;

[0168] (3) Slurry B was added to 50 g of E-44 epoxy resin matrix, and stirred at room temperature at a speed of 200 rpm for 120 min to obtain slurry C;

[0169] (4) 15 g of diethylenetriamine curing agent was added to slurry C, and stirred uniformly to obtain an oily graphene anticorrosive coating.

[0170] Example 17:

[0171] (1) 14 g of CPC dispersant was added to 30 g of GBL solvent, and stirred at room temperature until the dispersant was completely dissolved to obtain solution A;

[0172] (2) 1.66 g of graphene was added to solution A, and stirred at room temperature at a speed of 200 rpm for 30 min, and then ultrasonic treatment was performed for 120 min to obtain slurry B;

[0173] (3) Slurry B was added to 50 g of E-44 epoxy resin matrix, and stirred at room temperature at a speed of 200 rpm for 120 min to obtain slurry C;

[0174] (4) To the slurry C, 15 g of diethylene triamine curing agent was added, and after stirring evenly, an oily graphene anticorrosive coating was obtained.

[0175] Example 18:

[0176] (1) 14 g of BPC dispersant was added to 30 g of GBL solvent, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0177] (2) 1.66 g of graphene was added to solution A, and after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic treatment was performed for 120 min to obtain slurry B;

[0178] (3) Slurry B was added to 50 g of E-44 epoxy resin matrix, and after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C was obtained;

[0179] (4) To the slurry C, 15 g of diethylene triamine curing agent was added, and after stirring evenly, an oily graphene anticorrosive coating was obtained.

[0180] Example 19:

[0181] (1) 14 g of 1-hydroxyethyl-2-alkyl imidazoline dispersant was added to 30 g of GBL solvent, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0182] (2) 1.66 g of graphene was added to solution A, and after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic treatment was performed for 120 min to obtain slurry B;

[0183] (3) Slurry B was added to 50 g of E-44 epoxy resin matrix, and after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C was obtained;

[0184] (4) To the slurry C, 15 g of diethylene triamine curing agent was added, and after stirring evenly, an oily graphene anticorrosive coating was obtained.

[0185] Example 20:

[0186] (1) 14 g of N-alkyl morpholine oxide dispersant was added to 30 g of GBL solvent, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0187] (2) 1.66 g of graphene was added to solution A, and after stirring at room temperature at a speed of 200 rpm for 30 min, ultrasonic treatment was performed for 120 min to obtain slurry B;

[0188] (3) Slurry B was added to 50 g of E-44 epoxy resin matrix, and after stirring at room temperature at a speed of 200 rpm for 120 min, slurry C was obtained;

[0189] (4) To the slurry C, 15 g of diethylene triamine curing agent was added, and after stirring evenly, an oily graphene anticorrosive coating was obtained.

[0190] Example 21:

[0191] (1) To 30 g of GBL solvent, 14 g of didodecyl dimethyl ammonium bromide dispersant was added, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0192] (2) To solution A, 1.66 g of graphene was added, and after stirring at 200 rpm for 30 min at room temperature, ultrasonic was performed for 120 min, to obtain slurry B;

[0193] (3) To 50 g of E-44 epoxy resin matrix, slurry B was added, and after stirring at 200 rpm for 120 min at room temperature, slurry C was obtained;

[0194] (4) To the slurry C, 15 g of diethylene triamine curing agent was added, and after stirring evenly, an oily graphene anticorrosive coating was obtained.

[0195] Example 22:

[0196] (1) To 30 g of GBL solvent, 14 g of DODMAC dispersant was added, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0197] (2) To solution A, 1.66 g of graphene was added, and after stirring at 200 rpm for 30 min at room temperature, ultrasonic was performed for 120 min, to obtain slurry B;

[0198] (3) To 50 g of E-44 epoxy resin matrix, slurry B was added, and after stirring at 200 rpm for 120 min at room temperature, slurry C was obtained;

[0199] (4) To the slurry C, 15 g of diethylene triamine curing agent was added, and after stirring evenly, an oily graphene anticorrosive coating was obtained.

[0200] Example 23:

[0201] (1) To 30 g of GBL solvent, 14 g of lauroyl lysine hydrochloride dispersant was added, and after stirring at room temperature until the dispersant was completely dissolved, solution A was obtained;

[0202] (2) To solution A, 1.66 g of graphene was added, and after stirring at 200 rpm for 30 min at room temperature, ultrasonic was performed for 120 min, to obtain slurry B;

[0203] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, stir at room temperature at 200 rpm for 120 min, to obtain slurry C;

[0204] (4) To slurry C, add 15 g of diethylene triamine curing agent, stir uniformly, to obtain oil-based graphene anticorrosive coating.

[0205] Example 24:

[0206] (1) To 30 g of GBL solvent, add 14 g of glucoside trimethyl ammonium chloride dispersant, stir at room temperature until the dispersant is completely dissolved, to obtain solution A;

[0207] (2) To solution A, add 1.66 g of graphene, stir at room temperature at 200 rpm for 30 min, then ultrasonic for 120 min, to obtain slurry B;

[0208] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, stir at room temperature at 200 rpm for 120 min, to obtain slurry C;

[0209] (4) To slurry C, add 15 g of diethylene triamine curing agent, stir uniformly, to obtain oil-based graphene anticorrosive coating.

[0210] Example 25:

[0211] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved, to obtain solution A;

[0212] (2) To solution A, add 1.66 g of graphene, stir at room temperature at 200 rpm for 30 min, then ultrasonic for 120 min, to obtain slurry B;

[0213] (3) To 50 g of E-51 epoxy resin matrix, add slurry B, stir at room temperature at 200 rpm for 120 min, to obtain slurry C;

[0214] (4) To slurry C, add 15 g of diethylene triamine curing agent, stir uniformly, to obtain oil-based graphene anticorrosive coating.

[0215] Example 26:

[0216] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved, to obtain solution A;

[0217] (2) To solution A, add 1.66 g of graphene, stir at room temperature at 200 rpm for 30 min, then ultrasonic for 120 min, to obtain slurry B;

[0218] (3) To 50 g of E-35 epoxy resin matrix, add slurry B, stir at room temperature at a speed of 200 rpm for 120 min, to obtain slurry C;

[0219] (4) To slurry C, add 15 g of diethylene triamine curing agent, stir uniformly, to obtain oil-based graphene anticorrosive coating.

[0220] Example 27:

[0221] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved, to obtain solution A;

[0222] (2) To solution A, add 1.66 g of graphene, stir at room temperature at a speed of 200 rpm for 30 min, then ultrasonic for 120 min, to obtain slurry B;

[0223] (3) To 50 g of PVDF fluorocarbon resin matrix, add slurry B, stir at room temperature at a speed of 200 rpm for 120 min, to obtain slurry C;

[0224] (4) To slurry C, add 15 g of isocyanate curing agent, stir uniformly, to obtain oil-based graphene anticorrosive coating.

[0225] Example 28:

[0226] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved, to obtain solution A;

[0227] (2) To solution A, add 1.66 g of graphene, stir at room temperature at a speed of 200 rpm for 30 min, then ultrasonic for 120 min, to obtain slurry B;

[0228] (3) To 50 g of FEVE fluorocarbon resin matrix, add slurry B, stir at room temperature at a speed of 200 rpm for 120 min, to obtain slurry C;

[0229] (4) To slurry C, add 15 g of isocyanate curing agent, stir uniformly, to obtain oil-based graphene anticorrosive coating.

[0230] Example 29:

[0231] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved, to obtain solution A;

[0232] (2) To solution A, add 1.66 g of graphene, after stirring at 200 rpm for 30 min at room temperature, ultrasonic for 120 min, to obtain slurry B;

[0233] (3) To 50 g of PTFE fluorocarbon resin matrix, add slurry B, after stirring at 200 rpm for 120 min at room temperature, to obtain slurry C;

[0234] (4) To slurry C, add 15 g of isocyanate curing agent, after stirring uniformly, to obtain oil-based graphene anticorrosive coating.

[0235] Example 30:

[0236] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, after stirring until the dispersant is completely dissolved at room temperature, to obtain solution A;

[0237] (2) To solution A, add 1.66 g of graphene, after stirring at 200 rpm for 30 min at room temperature, ultrasonic for 120 min, to obtain slurry B;

[0238] (3) To 50 g of ETFE fluorocarbon resin matrix, add slurry B, after stirring at 200 rpm for 120 min at room temperature, to obtain slurry C;

[0239] (4) To slurry C, add 15 g of isocyanate curing agent, after stirring uniformly, to obtain oil-based graphene anticorrosive coating.

[0240] Example 31:

[0241] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, after stirring until the dispersant is completely dissolved at room temperature, to obtain solution A;

[0242] (2) To solution A, add 1.66 g of graphene, after stirring at 200 rpm for 30 min at room temperature, ultrasonic for 120 min, to obtain slurry B;

[0243] (3) To 50 g of THV fluorocarbon resin matrix, add slurry B, after stirring at 200 rpm for 120 min at room temperature, to obtain slurry C;

[0244] (4) To slurry C, add 15 g of isocyanate curing agent, after stirring uniformly, to obtain oil-based graphene anticorrosive coating.

[0245] Example 32:

[0246] (1) To 30 g of GBL solvent, add 14 g of DTAC dispersant, after stirring until the dispersant is completely dissolved at room temperature, to obtain solution A;

[0247] (2) To solution A, add 1.66 g of graphene, stir at 200 rpm for 30 min at room temperature, and then ultrasonic for 120 min to obtain slurry B;

[0248] (3) To 50 g of phenolic resin matrix, add slurry B, stir at 200 rpm for 120 min at room temperature to obtain slurry C;

[0249] (4) To slurry C, add 15 g of p-toluenesulfonic acid curing agent, stir uniformly to obtain oil-based graphene anticorrosive coating.

[0250] Example 33:

[0251] (1) To 30 g of NMP solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved to obtain solution A;

[0252] (2) To solution A, add 1.66 g of graphene, stir at 200 rpm for 30 min at room temperature, and then ultrasonic for 120 min to obtain slurry B;

[0253] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, stir at 200 rpm for 120 min at room temperature to obtain slurry C;

[0254] (4) To slurry C, add 15 g of diethylenetriamine curing agent, stir uniformly to obtain oil-based graphene anticorrosive coating.

[0255] Example 34:

[0256] (1) To 30 g of acetone solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved to obtain solution A;

[0257] (2) To solution A, add 1.66 g of graphene, stir at 200 rpm for 30 min at room temperature, and then ultrasonic for 120 min to obtain slurry B;

[0258] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, stir at 200 rpm for 120 min at room temperature to obtain slurry C;

[0259] (4) To slurry C, add 15 g of diethylenetriamine curing agent, stir uniformly to obtain oil-based graphene anticorrosive coating.

[0260] Example 35:

[0261] (1) To 30 g of MEK solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved to obtain solution A;

[0262] (2) To solution A, add 1.66 g of graphene, after stirring at 200 rpm for 30 min at room temperature, ultrasonic for 120 min, to obtain slurry B;

[0263] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at 200 rpm for 120 min at room temperature, to obtain slurry C;

[0264] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring uniformly, to obtain oil-based graphene anticorrosive coating.

[0265] Example 36:

[0266] (1) To 30 g of xylene solvent, add 14 g of DTAC dispersant, after stirring until the dispersant is completely dissolved at room temperature, to obtain solution A;

[0267] (2) To solution A, add 1.66 g of graphene, after stirring at 200 rpm for 30 min at room temperature, ultrasonic for 120 min, to obtain slurry B;

[0268] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at 200 rpm for 120 min at room temperature, to obtain slurry C;

[0269] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring uniformly, to obtain oil-based graphene anticorrosive coating.

[0270] Example 37:

[0271] (1) To 30 g of ethyl acetate solvent, add 14 g of DTAC dispersant, after stirring until the dispersant is completely dissolved at room temperature, to obtain solution A;

[0272] (2) To solution A, add 1.66 g of graphene, after stirring at 200 rpm for 30 min at room temperature, ultrasonic for 120 min, to obtain slurry B;

[0273] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, after stirring at 200 rpm for 120 min at room temperature, to obtain slurry C;

[0274] (4) To slurry C, add 15 g of diethylene triamine curing agent, after stirring uniformly, to obtain oil-based graphene anticorrosive coating.

[0275] Example 38:

[0276] (1) To 30 g of BCS solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved to obtain solution A;

[0277] (2) To solution A, add 1.66 g of graphene, stir at 200 rpm for 30 min at room temperature, then ultrasonic for 120 min to obtain slurry B;

[0278] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, stir at 200 rpm for 120 min at room temperature to obtain slurry C;

[0279] (4) To slurry C, add 15 g of diethylene triamine curing agent, stir uniformly to obtain an oily graphene anticorrosive coating.

[0280] Example 39:

[0281] (1) To 30 g of ethyl lactate solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved to obtain solution A;

[0282] (2) To solution A, add 1.66 g of graphene, stir at 200 rpm for 30 min at room temperature, then ultrasonic for 120 min to obtain slurry B;

[0283] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, stir at 200 rpm for 120 min at room temperature to obtain slurry C;

[0284] (4) To slurry C, add 15 g of diethylene triamine curing agent, stir uniformly to obtain an oily graphene anticorrosive coating.

[0285] Example 40:

[0286] (1) To 30 g of ethyl lactate solvent, add 14 g of DTAC dispersant, stir at room temperature until the dispersant is completely dissolved to obtain solution A;

[0287] (2) To solution A, add 1.66 g of graphene, stir at 200 rpm for 30 min at room temperature, then ultrasonic for 120 min to obtain slurry B;

[0288] (3) To 50 g of E-44 epoxy resin matrix, add slurry B, stir at 200 rpm for 120 min at room temperature to obtain slurry C;

[0289] (4) To slurry C, add 15 g of diethylene triamine curing agent, stir uniformly to obtain an oily graphene anticorrosive coating.

[0290] Compared with the prior art, the oily graphene anticorrosive coating provided in the application realizes breakthrough improvement in dispersion stability, corrosion resistance and other indicators. In order to more intuitively reflect the performance advantages of the technical scheme of the application in actual application, the application is tested as follows.

[0291] Test Example

[0292] 1. Stability test of graphene dispersion slurry

[0293] According to ISO 22412:2024, the dispersion stability of the graphene dispersion slurry (slurry C) obtained in step (3) of each embodiment is tested by dynamic light scattering method. The particle size of graphene particles in the slurry is tested by a laser particle size analyzer, and the test is repeated every 24 hours for 30 days. The particle size change rate ΔD is calculated according to the following formula:

[0294] ΔD=(D t -D0) / D0×100%.

[0295] Wherein, D t is the particle size of graphene particles determined on a certain day; D0 is the initial particle size of graphene particles. The particle size change rate each day and the average particle size change rate within 30 days are calculated. According to the conversion relationship of particle size change rate + suspension rate = 100%, the suspension stability of the particles is obtained, for example, when ΔD = 5%, the suspension rate is 95%.

[0296] 2. Corrosion resistance test of coating / paint

[0297] The corrosion resistance test of the coating is carried out according to the standard GB / T 10125-2021. The oily graphene anticorrosive coating prepared in each embodiment of the application is sprayed on the surface of carbon steel, and after the coating is completely dried and cured, an organic coating (thickness about 60 microns) is formed on the metal surface. After exposure in a neutral salt spray environment of 5% NaCl aqueous solution (pH 6.5-7.2) at a temperature of 35±2℃ for a certain period of time, the salt spray life of the coating is determined according to whether changes occur on the surface of the coating, such as the first corrosion point (blistering, peeling or rusting) of the coating.

[0298] The electrochemical impedance spectroscopy (EIS) test is carried out by using a standard three-electrode system, and the test conditions are: under open circuit voltage, the frequency range is 100 kHz-10 mHz, and the amplitude is 10 mV. After fitting the EIS results by ZView2 software, the charge transfer resistance value R ct is obtained.

[0299] The specific experimental data is arranged in the following table and figure.

[0300] Figure 1A comparison chart of dispersion stability of graphene dispersion slurry (Slurry C) of Examples 1-6 of the present application within 30 days. The dispersion stability of the slurry with time is obtained by monitoring the particle size change rate of graphene particles every day, which is converted into the suspension rate of graphene particles in the slurry.

[0301] Figure 2 Salt spray resistance life and charge transfer resistance value R of the coating of Examples 1-6 of the present application ct A comparison chart.

[0302] Figure 3 Salt spray resistance life and charge transfer resistance value R of the coating of Examples 7-10 of the present application ct A comparison chart.

[0303] Table 1 Average suspension rate of Slurry D of Examples 1-6 (30 days)

[0304] Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Graphene percentage (%) 0.1 1.0 1.5 2.0 2.5 3.0 Average suspension rate (%) 99.53 99.20 98.87 98.27 97.67 97.10

[0305] Table 2 Salt spray resistance life and charge transfer resistance value R of the coating of Examples 1-6 ct

[0306] Example Graphene percentage (%) Salt mist resistance life (h) [R ct (Ω·cm 2 )]]> Example 1 0.1 7950 6.2 x 10 8 ]]> Example 2 1.0 8730 1.9 x 10 9 ]]> Example 3 1.5 9680 7.3 x 10 9 ]] Example 4 2.0 9200 3.6 x 10 9 ]] Example 5 2.5 8960 8.5 x 10 8 ]] Example 6 3.0 7400 7.4 x 10 8 ]]

[0307] From Figure 1 and Table 1, it can be seen that within 30 days, the suspension rate of the graphene slurry of Examples 1-6 decreases slightly as the experimental time goes on, but the average suspension rate is greater than 97%; from the suspension rate results of Comparative Examples 1-6, it can be seen that as the graphene concentration in Slurry D increases, the average suspension rate of graphene particles decreases slightly, which indicates that the smaller the graphene concentration, the greater the particle suspension rate, and the more conducive to dispersion stability.

[0308] From Figure 2 and Table 2, it can be seen that the coating prepared by spraying the coating of Examples 1-6 can remain unchanged in a neutral salt spray environment for more than 7000 hours, which indicates that the corrosion resistance of the coating is better than that of traditional oil-based coatings (3000 hours). At the same time, as the percentage of graphene increases, the salt spray resistance life of the coating shows a trend of first increasing and then becoming shorter. This is because as the graphene concentration increases, the corrosion resistance of the coating is better, but if the graphene concentration is greater than 1.5%, the dispersion stability of graphene in the slurry decreases, thereby weakening the corrosion resistance of graphene.

[0309] From Figure 2 and the charge transfer resistance R ct value results in Table 2, it can be seen that as the graphene concentration increases, R ct first increases and then decreases, which indicates that the corrosion resistance is optimal when the graphene concentration is 1.5%. This result is consistent with the salt spray resistance life rule.

[0310] Table 3 Salt fog life and charge transfer resistance value R of coating of Examples 7-10 ct

[0311] Example Example 7 Example 8 Example 9 Example 10 Example 3 DTAC:DODMAC (mass ratio) 9:1 8:2 7:3 6:4 10:0 Salt mist resistance life (h) 9950 10780 9840 8960 9680 [R ct (Ω·cm 2 )]]> 7.9 x 10 9 ]] 8.8 x 10 9 ]] 7.5 x 10 9 ]]> 6.6 x 10 9 ]]> 7.3 x 10 9 ]]>

[0312] From Figure 3 As can be seen from Table 3, the composite dispersant prepared by compounding an appropriate amount of dodecyl trimethyl ammonium chloride (DTAC) and dioctadecyl dimethyl ammonium chloride (DODMAC) is beneficial to improving the salt fog life and charge transfer resistance value of the coating. In Example 3, the dispersant is only DTAC. When the proportion of DODMAC in the composite dispersant is increased (Examples 7-10), the salt fog life and charge transfer resistance value of the coating show a trend of first increasing and then decreasing. When DTAC:DODMAC = 8:2, the corrosion resistance of the coating is the best. This shows that the composite dispersant prepared by appropriately compounding quaternary ammonium salts and gemini quaternary ammonium salts can effectively improve the corrosion resistance of the coating.

[0313] Table 4 Salt fog life and charge transfer resistance value R of coating of Examples 11-13 ct

[0314]

[0315] As can be seen from the results in Table 4, the types of quaternary ammonium salts and gemini quaternary ammonium salts in the composite dispersant affect the corrosion resistance of the coating. From the results of the salt fog life and charge transfer resistance value, the order of the compounding dispersants involved in the present application for improving the corrosion resistance of the coating is: DTAC > CTAB; DODMAC > dioctadecyl dimethyl dibromide. When DTAC and DODMAC are compounded, the salt fog life of the coating is the longest, and the charge transfer resistance value is the largest. The above results show that although the differences in the types of quaternary ammonium salts and gemini quaternary ammonium salts in the composite dispersant result in a little difference in the performance of the coating, they all significantly improve the corrosion resistance of the coating. The salt fog life of the obtained coating is more than 9000 h, and the charge transfer resistance value (R ct ) can reach 10 9 orders of magnitude.

[0316] Table 5 Salt fog life and charge transfer resistance value R of coating of Examples 14-24 ct

[0317]

[0318]

[0319] Examples 14-24 and Example 3 all use single-component dispersants. DTAC and CTAB are quaternary ammonium salt dispersants, DAAHCl and N-methyl dodecylamine hydrochloride are amine salt dispersants, CPC and BPC are pyridine salt dispersants, 1-hydroxyethyl-2-alkyl imidazoline and N-alkyl morpholine oxide are heterocyclic dispersants, didodecyl dimethyl dibromide ammonium and DODMAC are gemini quaternary ammonium salt dispersants, lauroyl lysine hydrochloride and glucoside trimethyl ammonium chloride are bio-based dispersants. As can be seen from the results in Table 5, the type of dispersant has a great influence on the salt spray life and charge transfer resistance value of the coating. The order of the types of dispersants involved in this application for improving the corrosion resistance of the coating is: quaternary ammonium salt dispersant > gemini quaternary ammonium salt dispersant > pyridine salt dispersant > heterocyclic dispersant > amine salt dispersant > bio-based dispersant.

[0320] Table 6 Salt spray life and charge transfer resistance value R of the coating of Examples 25-32 ct

[0321] Example Dispersant Oily base resin Curing agent Salt mist resistance life (h) [R ct (Ω·cm 2 )]]> Example 3 DTAC E-44 Diethylenetriamine 9680 7.3 x 10 9 ]]> Example 25 DTAC E-51 Diethylenetriamine 9550 7.2 x 10 9 ]]> Example 26 DTAC E-35 Diethylenetriamine 9400 6.9 x 10 9 ]]> Example 27 DTAC PVDF Isocyanate 9700 7.4 x 10 9 ]] Example 28 DTAC FEVE Isocyanate 9780 7.5 x 10 9 ]] Example 29 DTAC PTFE Isocyanate 10930 9.2 x 10 9 ]]> Example 30 DTAC ETFE Isocyanate 9880 7.7 x 10 9 ]]> Example 31 DTAC THV Isocyanate 9950 7.8 x 10 9 <!-- 17 -->]]> Example 32 DTAC Phenol formaldehyde resin Benzene disulfonic acid 6800 8.6 x 10 8 ]]>

[0322] Examples 3 and Examples 25-32 all use DTAC dispersant, the percentage of graphene is 1.5%, the difference is the type of oily matrix resin and its corresponding curing agent. E-35, E-44, E-51 are bisphenol A type epoxy resins, PVDF, FEVE, PTFE, ETFE, THV are fluorocarbon resins. As can be seen from the results in Table 6, the order of the corrosion resistance of different oily matrix graphene anticorrosive coatings is: bisphenol A type epoxy resin matrix > fluorocarbon resin matrix > phenolic resin matrix. Specifically, the corrosion resistance of E-44 matrix coating in bisphenol A type epoxy resin is better than that of E-51 and E-35; the order of the corrosion resistance of fluorocarbon resin matrix coating is: PTFE > THV > ETFE > FEVE > PVDE. The experimental results show that the graphene slurry and the preparation method thereof provided by the present application are suitable for three different types of oily matrix of bisphenol A type epoxy resin, fluorocarbon resin and phenolic resin.

[0323] Table 7 Salt spray life and charge transfer resistance value R of the coating of Examples 33-40 ct

[0324] Example Dispersant Graphene percentage (%) Solvent Salt mist resistance life (h) [R ct (Ω·cm 2 )]]> Example 33 DTAC 1.5 NMP 9550 7.2 x 10 9 ]]> Example 34 DTAC 1.5 Acetone 8200 4.7 x 10 9 ]]> Example 35 DTAC 1.5 MEK 8050 4.6 x 10 9 ]]> Example 36 DTAC 1.5 Xylene 7850 4.0 x 10 9 ]]> Example 37 DTAC 1.5 Ethyl acetate 7250 3.8 x 10 9 ]]> Example 38 DTAC 1.5 BCS 7000 3.4 x 10 9 ]]> Example 39 DTAC 1.5 Ethyl lactate 6850 8.9 x 10 8 ]]> Example 40 DTAC 1.5 Terpineol 6570 8.5 x 10 8 ]]> Example 3 DTAC 1.5 GBL 9680 7.3 x 10 9 ]]

[0325] The application disperses 1.5% graphene in different types of solvents with DTAC as a dispersant, and the results are shown in Table 7. GBL and NMP are high-boiling solvents, acetone and MEK are ketone solvents, xylene is an aromatic hydrocarbon solvent, ethyl acetate is an ester solvent, BCS is an alcohol ether solvent, and ethyl lactate and terpineol are bio-based solvents. The salt spray resistance and charge transfer resistance of the coating applied with different types of solvents are in the order of: high-boiling solvent > ketone solvent > aromatic hydrocarbon solvent > ester solvent > alcohol ether solvent > bio-based solvent. This shows that the graphene slurry dispersion method provided by the application is suitable for different types of solvents, and the corrosion resistance of the coating is better than that of traditional oil-based coatings.

[0326] Test Example

[0327] 3. Volatile organic compound (VOC) content detection of the coating

[0328] The VOC content of the coating was detected according to the national standard GB / T 23986-2009 “Determination of volatile organic compounds (VOC) content of color paints and varnishes by gas chromatography”.

[0329] The results show that the VOC of the coating obtained in the application is 50-80 g / L, which is better than the limit of 150 g / L in the national standard “Low volatile organic compound content coating product technical requirements” (GB / T 38597-2020).

[0330] 4. No heavy metal residue risk

[0331] The application does not introduce any additional metals or heavy metals, so there is no heavy metal residue problem.

[0332] In order to illustrate the important influence of dispersants on the stability of graphene slurry and the corrosion resistance of the coating, the performance evaluation of Comparative Examples 1-6 was carried out.

[0333] Comparative Example 1:

[0334] (1) Add 15 g of diethylenetriamine curing agent to 50 g of E-44 epoxy resin matrix, stir uniformly, and obtain an oil-based matrix coating.

[0335] Comparative Example 2:

[0336] (1) Add 15 g of isocyanate curing agent to 50 g of PTFE fluorocarbon resin matrix, stir uniformly, and obtain an oil-based matrix coating.

[0337] Comparative Example 3:

[0338] (1) Add 15 g of p-toluenesulfonic acid curing agent to 50 g of phenolic resin matrix, stir uniformly, and obtain an oil-based matrix coating.

[0339] Comparative Example 4:

[0340] (1) 1.66 g of graphene was added to 30 g of GBL solvent, stirred at 200 rpm for 30 min at room temperature, and then ultrasonicated for 120 min to obtain slurry B;

[0341] (2) Slurry B was added to 50 g of E-44 epoxy resin matrix, stirred at 200 rpm for 120 min at room temperature to obtain slurry C;

[0342] (3) 15 g of diethylene triamine curing agent was added to slurry C, and stirred uniformly to obtain an oily graphene anticorrosion coating.

[0343] Comparative Example 5:

[0344] (1) 1.66 g of graphene was added to 30 g of GBL solvent, stirred at 200 rpm for 30 min at room temperature, and then ultrasonicated for 120 min to obtain slurry B;

[0345] (2) Slurry B was added to 50 g of PTFE fluorocarbon resin matrix, stirred at 200 rpm for 120 min at room temperature to obtain slurry C;

[0346] (3) 15 g of isocyanate curing agent was added to slurry C, and stirred uniformly to obtain an oily graphene anticorrosion coating.

[0347] Comparative Example 6:

[0348] (1) 1.66 g of graphene was added to 30 g of GBL solvent, stirred at 200 rpm for 30 min at room temperature, and then ultrasonicated for 120 min to obtain slurry B;

[0349] (2) Slurry B was added to 50 g of phenolic resin matrix, stirred at 200 rpm for 120 min at room temperature to obtain slurry C;

[0350] (3) 15 g of p-toluenesulfonic acid curing agent was added to slurry C, and stirred uniformly to obtain an oily graphene anticorrosion coating.

[0351] The performance test results of Comparative Examples 1-6, Example 3, Example 29, and Example 32 are shown in Table 8. Comparative Examples 1-3 are different oily matrix coatings without graphene, and the phenolic resin, E-44 epoxy resin, and PTFE fluorocarbon resin coatings obtained therefrom appeared bubbles in a neutral salt spray environment at 1070 h, 1860 h, and 2350 h, respectively, and the charge transfer resistance values were all less than 10 3Example 3, 29, 32, the corrosion resistance of the coating is excellent. 4 Example 3, 29, 32, the corrosion resistance of the coating is excellent. 8 -10 9 Example 3, 29, 32, the corrosion resistance of the coating is excellent.

[0352] Table 8 Performance test results of Comparative Examples 1-6 and Examples 3, 9, 32

[0353]

[0354]

[0355] The above-described examples only express the specific implementation of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the protection scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the technical concept of the present application, a number of modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. An oil-based graphene anti-corrosion coating, characterized in that, The raw materials include the following percentages by weight: 20%–70% oily resin matrix, 0.1%–3% graphene, 5%–25% dispersant, 15%–40% solvent, and 5%–60% curing agent; wherein the oily resin matrix is ​​one of bisphenol A type epoxy resin, fluorocarbon resin, and phenolic resin.

2. The oil-based graphene anti-corrosion coating according to claim 1, characterized in that, The solvent is one of N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), acetone, methyl ethyl ketone (MEK), xylene, ethyl acetate, ethylene glycol butyl ether (BCS), ethyl lactate, and terpineol.

3. The oil-based graphene anti-corrosion coating according to claim 1, characterized in that, The dispersant is one of the following: hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium chloride (DTAC), dodecylamine hydrochloride (DAAHCl), N-methyldodecylamine hydrochloride, hexadecylpyridine chloride (CPC), benzylpyridine chloride (BPC), 1-hydroxyethyl-2-alkylimidazoline, N-alkylmorpholine oxide, bis(dodecyldimethylammonium bromide), bis(octadecyldimethylammonium chloride) (DODMAC), lauroyl lysine hydrochloride, glucoside trimethylammonium chloride, or a composite dispersant.

4. The oil-based graphene anti-corrosion coating according to claim 3, characterized in that, The composite dispersant is a mixture of quaternary ammonium salt dispersant and gemini quaternary ammonium salt dispersant, wherein the mass ratio of quaternary ammonium salt dispersant to gemini quaternary ammonium salt dispersant is (9:1) to (6:4); the quaternary ammonium salt dispersant is one of hexadecyltrimethylammonium bromide (CTAB) and dodecyltrimethylammonium chloride (DTAC); the gemini quaternary ammonium salt dispersant is one of dodecyldimethyldibromide and dodecyldimethylammonium chloride (DODMAC).

5. The oil-based graphene anti-corrosion coating according to claim 1, characterized in that, The bisphenol A type epoxy resin is one of E-51, E-44, and E-35; And / or, the fluorocarbon resin is one of polyvinylidene fluoride resin (PVDF), fluoroethylene vinyl ether copolymer resin (FEVE), polytetrafluoroethylene resin (PTFE), ethylene-tetrafluoroethylene copolymer resin (ETFE), and tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer resin (THV).

6. The oil-based graphene anti-corrosion coating according to claim 1, characterized in that, The curing agent is selected from one of diethylenetriamine, isocyanate, and p-toluenesulfonic acid; And / or, when the oily resin matrix is ​​selected from bisphenol A type epoxy resin, the curing agent is diethylenetriamine; And / or, when the oily resin matrix is ​​selected from fluorocarbon resin, the curing agent is diethylenetriamine; And / or, when the oily resin matrix is ​​selected from phenolic resin, the curing agent is p-toluenesulfonic acid.

7. The oil-based graphene anti-corrosion coating according to any one of claims 1-6, characterized in that, The raw materials include the following percentages by weight: 20%–60% oily resin matrix, 0.1%–2.5% graphene, 5%–20% dispersant, 15%–30% solvent, and 10%–45% curing agent.

8. The method for preparing the oil-based graphene anti-corrosion coating according to any one of claims 1-7, characterized in that, Includes the following steps: S1: Weigh the raw materials according to any one of claims 1-7; S2: Add a dispersant to the solvent and stir at room temperature until the dispersant is fully dissolved to obtain solution A; S3: Add graphene to solution A, stir at 100 rpm to 500 rpm for 10-30 min at room temperature, and sonicate for 30-120 min to obtain slurry B; S4: Add slurry B to the oily resin matrix and stir at 100 rpm to 500 rpm for 10-120 min at room temperature to obtain slurry C; S5: Add curing agent to slurry C and stir evenly to obtain oil-based graphene anti-corrosion coating.

9. A graphene anti-corrosion coating, characterized in that, The graphene anti-corrosion coating is formed by coating the oil-based graphene anti-corrosion coating of any one of claims 1-7 or the oil-based graphene anti-corrosion coating prepared by the preparation method of claim 8 onto the surface of a substrate, and then drying and curing it; the substrate includes a metal substrate and a non-metal substrate.

10. The application of the oil-based graphene anti-corrosion coating according to any one of claims 1-7 in any of the following, characterized in that, include: (a1) Prepare a surface coating for energy infrastructure, wherein the basic energy infrastructure includes at least one of oil and gas storage and transportation equipment, new energy equipment and energy storage devices; (a2) Prepare a surface coating for marine engineering and heavy equipment, wherein the marine engineering and heavy equipment includes at least one of cross-sea bridges, port facilities, ships and offshore platforms; (a3) Prepare a surface coating for an industrial building structure, wherein the industrial building structure includes at least one of chemical equipment, industrial pipelines, industrial buildings and color steel plates.

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