Graphene modified gradient distribution high temperature resistant anticorrosion coating and preparation method thereof

Abstract

The present invention discloses a graphene-modified gradient-distributed high-temperature-resistant anticorrosion coating and its preparation method. The anticorrosion coating comprises a graphene thermoplastic resin additive, an organosilicon hybrid epoxy resin base, and a curing agent. The graphene thermoplastic resin additive comprises the following components by mass: 45-59 parts xylene, 40-50 parts aromatic hydrocarbon resin, 0.05-1 part modified graphene oxide, and 0.5-2.5 parts fumed silica. The organosilicon hybrid epoxy resin base comprises the following components by mass: 50-80 parts organosilicon hybrid epoxy resin, 1-5 parts n-butanol, 1-5 parts butyl acetate, 5-20 parts hollow glass microspheres, 3-15 parts titanium dioxide, 3-15 parts mica iron oxide, and 0.5-8 parts modified bentonite. The present invention is an organic-inorganic hybrid high-temperature-resistant anticorrosion coating that can be applied by cold spraying and exhibits high adhesion, excellent high-temperature resistance, and excellent corrosion resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature resistant anti-corrosion coatings, and specifically relates to a graphene-modified gradient-distributed high-temperature resistant anti-corrosion coating and a preparation method thereof. Background Art

[0002] In the fields of aviation, aerospace, and shipbuilding, a large number of core components and key structural parts of high-end equipment are subjected to long-term high-temperature operating conditions. Their operating conditions directly affect the operational stability of aircraft, spacecraft, and aircraft. Therefore, research on high-temperature anti-corrosion coatings has attracted increasing attention both domestically and internationally. Cold-sprayed organic coatings offer strong substrate bonding, easy application, and widespread application. However, they face challenges such as unstable performance and a short effective protective life in high-temperature corrosive environments. This is because thermosetting resins are susceptible to oxidation and thermal decomposition at high temperatures, leading to cracking or delamination of the coating. Thermoplastic resins, on the other hand, soften, melt, and flow at high temperatures, causing the coating to desorb from the substrate surface and lose its protective effect. Coatings made from a combination of thermosetting and thermoplastic resins can leverage the fluidity of the thermoplastic resin to mitigate shrinkage stresses in the thermosetting resin to a certain extent. The melting and flow of the thermoplastic resin can even repair cracks and glazing in the coating. The thermosetting resin, on the other hand, slows the fluidity of the thermoplastic resin at high temperatures, maintaining its morphological stability. However, thermosetting resins and thermoplastic resins usually face the problem of poor compatibility, which makes it very easy for the two to form phase separation in the coating and generate defects.

[0003] To address these issues, there is an urgent need to develop novel cold-sprayed organic coatings that meet the requirements for high-temperature resistance, corrosion resistance, and long life. Graphene, a two-dimensional carbon nanomaterial, possesses excellent properties such as high electrical and thermal conductivity, high light transmittance, and high shielding properties. By grafting oxygen-containing groups such as hydroxyl, carboxyl, and epoxy groups onto the graphene surface to form graphene oxide, various properties of graphene can be effectively manipulated, expanding its application potential. Summary of the Invention

[0004] The purpose of the present invention is to provide an organic-inorganic hybrid high-temperature resistant anti-corrosion coating that can be cold-sprayed and has high adhesion, excellent high-temperature resistance and corrosion resistance. To this end, the present invention also provides a preparation method of the anti-corrosion coating.

[0005] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0006] The present invention provides a graphene-modified gradient-distributed high-temperature-resistant anti-corrosion coating. The anti-corrosion coating comprises a graphene thermoplastic resin additive, an organosilicon hybrid epoxy resin base material, and a curing agent.

[0007] The mass fraction of the graphene thermoplastic resin additive component is: 45-59 parts of xylene, 40-50 parts of aromatic hydrocarbon resin, 0.05-1 part of modified graphene oxide, and 0.5-2.5 parts of fumed silica;

[0008] The mass fractions of the organosilicon hybrid epoxy resin base components are: 50-80 parts of organosilicon hybrid epoxy resin, 1-5 parts of n-butanol, 1-5 parts of butyl acetate, 5-20 parts of hollow glass microspheres, 3-15 parts of titanium dioxide, 3-15 parts of mica iron oxide, and 0.5-8 parts of modified bentonite;

[0009] The mass fractions of the aminosilane curing agent components are: 1 to 5 parts of n-butanol, 1 to 5 parts of butyl acetate, and 90 to 98 parts of aminosilane coupling agent.

[0010] Another object of the present invention is to provide a method for preparing the above-mentioned coating, characterized in that the steps are as follows:

[0011] Step 1: Add graphene oxide, anhydrous ethanol and silane coupling agent to deionized water, and ultrasonically treat at a power of 100-300W for 10-30 minutes to obtain a graphene oxide dispersion. Then place the above dispersion in a constant temperature oil bath at 50-80°C and stir continuously for 12-24 hours to obtain a modified graphene oxide solution. Use a microporous membrane with a pore size of 0.25-0.5μm to filter the modified graphene oxide solution, and wash it with anhydrous ethanol for 5-10 times. Finally, place the modified graphene oxide wet cake in a vacuum drying oven at 40-60°C and dry it for 5-10 hours to obtain silane-modified graphene oxide;

[0012] Step 2: adding the silane-modified graphene oxide to a xylene solution, treating the solution under ultrasonication at a power of 100 to 300 W for 0.5 hour to obtain a graphene oxide dispersion, then adding an aromatic resin and an oleophilic fumed silica, and continuously stirring the solution at a speed of 300 to 600 rpm in a constant temperature oil bath at 50 to 80° C. for 0.5 to 2 hours to obtain an additive;

[0013] Step 3: Mixing the components of the organosilicon hybrid epoxy resin base material, and continuously stirring at a speed of 300 to 600 r / min at room temperature for 15 to 60 minutes to obtain a base material;

[0014] Step 4: Mix the additives with the base material, and continue stirring at a speed of 300 to 600 r / min at room temperature for 15 to 60 minutes. Finally, add the components of the curing agent and continue stirring at a speed of 300 to 600 r / min at room temperature for 15 to 30 minutes to obtain a high temperature resistant anti-corrosion coating.

[0015] Step 5: Apply the above-mentioned high-temperature resistant anti-corrosion coating on the substrate, dry it at room temperature for 12 to 60 hours to form a cured coating film, then increase the temperature from room temperature to 400 to 700°C at a heating rate of 3 to 15°C / min, and maintain it at 400 to 700±10°C for 2 to 8 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0016] In step (1) of the present invention, the graphene oxide is lightly oxidized graphene, having 1 to 5 layers, a transverse equivalent diameter of the flakes of 0.5 to 5 μm, and oxygen-containing groups of one or a combination of hydroxyl, carboxyl, and epoxy groups, with an oxygen-carbon ratio in the range of 0.1 to 2, preferably 0.2 to 0.5.

[0017] In step (1) of the present invention, the silane coupling agent is selected from one or any combination of γ-aminopropyltriethoxysilane, vinyltriethoxysilane, and γ-glycidyloxypropyltrimethoxysilane.

[0018] In step (1) of the present invention, the amount of graphene oxide is 0.1% to 1% of the amount of anhydrous ethanol, preferably 0.2% to 0.5%; the amount of silane coupling agent is 0.1% to 10% of the amount of anhydrous ethanol, preferably 0.2% to 5%; the amount of water is 5% to 100% of the amount of anhydrous ethanol, preferably 10% to 50%.

[0019] In step (2) of the present invention, the aromatic hydrocarbon resin includes but is not limited to one or a mixture of C5 aliphatic petroleum resin, C9 aromatic petroleum resin, DCPD cycloaliphatic diene resin, hydrogenated petroleum resin, and condensed polynuclear aromatic hydrocarbon resin.

[0020] In step (2) of the present invention, the primary particle size of the oleophilic fumed silica is 10 to 40 nm, and the surface-grafted modifier includes but is not limited to one or a combination of the following: polydimethylsiloxane, dimethyldichlorosilane, hexamethyldisilazane, γ-aminopropyltriethoxysilane, and trimethoxypropylaminosilane.

[0021] In step (3) of the present invention, considering that the organosilicon hybrid epoxy resin must ensure the integrity of the cured coating film and ensure that the high-temperature resistant filler has a sufficiently high ratio, the amount of the organosilicon hybrid epoxy resin in the base material is preferably 56 to 72 parts.

[0022] In step (3) of the present invention, considering that the coating must ensure both excellent high temperature resistance and good mechanical properties, the diameter of the hollow glass microspheres is preferably 50 to 200 μm, the wall thickness is preferably 1 to 2 μm, and the amount used is preferably 10 to 15 parts.

[0023] In step (3) of the present invention, in order to enable the coating to obtain excellent high temperature resistance, the size of the titanium dioxide added to the base material is preferably 100nm to 500nm, and the amount is preferably 5 to 10 parts.

[0024] In step (3) of the present invention, in order to ensure the excellent film-forming property and high temperature resistance of the coating, the mica iron oxide added to the base material is preferably in a size between 50 μm and 200 μm, and the amount used is preferably 5 to 10 parts.

[0025] In step (3) of the present invention, in order to ensure the dispersion stability of various high-temperature resistant pigments and fillers added to the coating and the long-term stability of the high-temperature resistance and corrosion resistance of the coating, the amount of modified bentonite is preferably 1 to 5 parts, and the surface grafted modifier is preferably one or more of the following: dioctadecyl dimethyl ammonium chloride, glycidyl acrylate, dimethylaminoethyl methacrylate, and 3-sulfonate propyl methacrylate potassium salt.

[0026] In step (4) of the present invention, in order to ensure that the coating forms a good gradient distribution after "secondary curing" and maintain the surface uniformity of the coating, the amount of the additive should be 20% to 40% of the base material, preferably 25% to 35%.

[0027] In step (4) of the present invention, in order to ensure that the coating forms a film quickly and maintains good mechanical properties after "secondary curing", the amount of curing agent used should be 22.5% to 30% of the base material, preferably 25% to 27.5%.

[0028] In step (5) of the present invention, in order to ensure uniform crosslinking and curing of the coating, it is preferably cured at room temperature for 24 to 48 hours, and then preferably heated from room temperature to 500 to 600°C at a heating rate of 5 to 10°C / min, and maintained at a temperature of 500 to 600±10°C for 2 to 5 hours.

[0029] The three-component graphene high-temperature corrosion-resistant coating proposed in this paper exhibits excellent corrosion resistance, excellent adhesion, and high-temperature resistance. The coating cures and dries within 48 hours, with a thickness of approximately 100 to 150 μm. Under high-temperature conditions, it forms a gradient distribution and undergoes secondary curing, further enhancing the coating's stability under high-temperature conditions and providing long-term, effective protection for metal substrates exposed to these conditions.

[0030] The inventors have found through experiments that when aromatic hydrocarbon resin is directly added to silicone epoxy resin coating, the aromatic hydrocarbon resin will be distributed in the silicone epoxy coating in the form of phase separation. When the coating is placed in a high temperature environment, the aromatic hydrocarbon resin will expand due to heat, while the silicone epoxy resin will solidify and shrink, which will lead to a more obvious phase separation phenomenon in the coating, and eventually the coating will have a large number of cracks and peeling and lose its effective protective effect on the substrate. Adding a small amount of modified graphene oxide to the coating according to the above steps can greatly improve the compatibility between the aromatic hydrocarbon resin and the silicone epoxy resin, so that the two are fully integrated and become a whole in the coating. When the graphene oxide modified coating is placed in a high temperature environment, the aromatic hydrocarbon resin will evenly penetrate from the inside of the coating to the surface of the coating to form a gradient distribution, and further cross-link and solidify on the surface of the coating, eventually forming pyrolytic carbon and glassy carbon layers. The pyrolytic carbon and glassy carbon layers have excellent high temperature resistance, corrosion resistance and heat insulation properties, thereby forming a high temperature protection effect on the underlying silicone epoxy coating.

[0031] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0032] The use of modified graphene oxide eliminates the incompatibility between aromatic hydrocarbon resin and silicone epoxy resin, allowing the two to be evenly fused and form a good connection through graphene oxide, thereby obtaining excellent mechanical properties. The specific advantages of this coating are: (1) Combining thermosetting resin and thermoplastic resin and fully fusion, the coating has the characteristics of high adhesion and high density, as well as excellent heat resistance and chemical stability; (2) During the high-temperature curing process, silicone resin as a thermosetting resin continuously crosslinks and shrinks, while aromatic hydrocarbon resin as a thermoplastic resin melts and expands, so the aromatic hydrocarbon resin will migrate evenly from the bottom layer to the surface layer in the silicone resin matrix coating, and finally form a gradient distribution with strong binding force; (3) Modified graphene makes the aromatic hydrocarbon resin evenly distributed in the coating, and evenly seeps out under high temperature conditions, maintaining the structural integrity of the coating, and making the aromatic hydrocarbon resin form a gradient distribution on the surface of the coating; (4) Modified graphene not only ensures the uniform distribution and (5) After the "secondary curing" of the coating surface, the aromatic resin forms a pyrolytic carbon and glassy carbon structure that is highly stable under high temperature and corrosive environment, which provides good protection for the underlying silicone resin and the protected substrate; (6) The gradient distribution of the aromatic resin under high temperature conditions makes the pyrolytic carbon and glassy carbon structure formed by the aromatic resin have high adhesion to the bottom layer, and forms air-insulating protection for the underlying silicone epoxy resin, so that the silicone epoxy resin can better undergo ceramic transformation under high temperature conditions, thereby showing better high temperature resistance and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structure of silicone epoxy coating.

[0034] Figure 2 Schematic diagram of the graphene-modified gradient distribution coating structure. DETAILED DESCRIPTION

[0035] Example 1

[0036] The anti-corrosion coating formula of the present invention is as follows:

[0037] Base material formula: 70kg of silicone hybrid epoxy resin, 2kg of n-butanol, 3kg of butyl acetate, 10kg of hollow glass microspheres, 8kg of titanium dioxide, 5kg of mica iron oxide, and 2kg of modified bentonite.

[0038] Additive formula: C9 aromatic resin 14.5kg, xylene 14.5kg, graphene oxide 0.5kg, fumed silica 0.5kg

[0039] Curing agent formula: 17.5 kg of 3-aminopropyltriethylsilane and 0.5 kg of n-butanol.

[0040] The preparation method of the anti-corrosion coating of the present invention:

[0041] 0.5 g of graphene oxide, 5 g of the silane coupling agent γ-aminopropyltriethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 150 W for 30 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 50°C constant-temperature oil bath and stirred continuously for 14 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.25 μm and washed six times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 45°C for 10 hours to obtain silane-modified graphene oxide.

[0042] 70 kg of organosilicon hybrid epoxy resin, 2 kg of n-butanol, 3 kg of butyl acetate, 10 kg of hollow glass microspheres, 8 kg of titanium dioxide, 5 kg of mica iron oxide, and 2 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 600 rpm for 20 minutes at room temperature to obtain a base material. 14.5 kg of aromatic hydrocarbon resin, 14.5 kg of xylene, 0.5 kg of modified graphene, and 0.5 kg of fumed silica were sequentially added to the vessel and stirred at 300 rpm in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 17.5 kg of 3-aminopropyltriethylsilane and 0.5 kg of n-butanol were sequentially added to another reaction vessel and stirred at 500 rpm for 5 minutes at room temperature to obtain a curing agent. 100 kg of the base material and 30 kg of the additive were mixed and stirred at 500 rpm for 25 minutes at room temperature. Finally, 18 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0043] The above-mentioned coating was applied to the surface of the substrate by brushing, cured at room temperature for 24 hours to obtain a coating film, and then heated from room temperature to 500°C at a heating rate of 5°C / min, and maintained at 500±10°C for 2 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0044] Example 2

[0045] The anti-corrosion coating formula of the present invention is as follows:

[0046] Base material formula: 60kg of silicone hybrid epoxy resin, 4.5kg of n-butanol, 4kg of butyl acetate, 12.5kg of hollow glass microspheres, 12.5kg of titanium dioxide, 5kg of mica iron oxide, and 1.5kg of modified bentonite.

[0047] Additive formula: C5 petroleum resin 12kg, xylene 17kg, modified graphene 0.5kg, fumed silica 0.5kg

[0048] Curing agent formula: 15kg of 3-aminopropyltriethylsilane and 1kg of n-butanol.

[0049] The preparation method of the anti-corrosion coating of the present invention:

[0050] 0.75 g of graphene oxide, 10 g of the silane coupling agent vinyltriethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 200 W for 30 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 60°C constant-temperature oil bath and stirred continuously for 15 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.25 μm and washed five times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 55°C for 12 hours to obtain silane-modified graphene oxide.

[0051] 60 kg of organosilicon hybrid epoxy resin, 4.5 kg of n-butanol, 4 kg of butyl acetate, 12.5 kg of hollow glass microspheres, 12.5 kg of titanium dioxide, 5 kg of micaceous iron oxide, and 1.5 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 600 rpm for 20 minutes at room temperature to obtain a base material. 12 kg of C5 petroleum resin, 17 kg of xylene, 0.5 kg of graphene oxide, and 0.5 kg of fumed silica were sequentially added to the vessel and stirred at 300 rpm in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 15 kg of 3-aminopropyltriethylsilane and 1 kg of n-butanol were sequentially added to another reaction vessel and stirred at 500 rpm for 5 minutes at room temperature to obtain a curing agent. 100 kg of the base material and 30 kg of the additive were mixed and stirred at 500 rpm for 25 minutes at room temperature. Finally, 16 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0052] The above-mentioned coating was applied to the surface of the metal substrate by brushing, cured at room temperature for 30 hours to obtain a coating film, and then heated from room temperature to 500°C at a heating rate of 10°C / min, and maintained at 500±10°C for 3 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0053] Example 3

[0054] The anti-corrosion coating formula of the present invention is as follows:

[0055] Base material formula: 64kg of silicone hybrid epoxy resin, 3kg of n-butanol, 3kg of butyl acetate, 13.5kg of hollow glass microspheres, 10kg of titanium dioxide, 5kg of mica iron oxide, and 1.5kg of modified bentonite.

[0056] Additive formula: hydrogenated petroleum resin 16kg, xylene 14kg, graphene oxide 0.5kg, fumed silica 0.5kg

[0057] Curing agent formula: 16kg of 3-aminopropyltriethylsilane and 1kg of n-butanol.

[0058] The preparation method of the anti-corrosion coating of the present invention:

[0059] 0.7 g of graphene oxide, 8 g of the silane coupling agent γ-glycidyloxypropyltrimethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 200 W for 30 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 60°C constant-temperature oil bath and stirred continuously for 15 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.35 μm and washed 10 times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 50°C for 16 hours to obtain silane-modified graphene oxide.

[0060] 64 kg of organosilicon hybrid epoxy resin, 3 kg of n-butanol, 3 kg of butyl acetate, 13.5 kg of hollow glass microspheres, 10 kg of titanium dioxide, 5 kg of mica iron oxide, and 1.5 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 600 rpm for 25 minutes at room temperature to obtain a base material. 16 kg of hydrogenated petroleum resin, 14 kg of xylene, 0.5 kg of graphene oxide, and 0.5 kg of fumed silica were sequentially added to the vessel and stirred at 300 rpm in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 16 kg of 3-aminopropyltriethylsilane and 1 kg of n-butanol were sequentially added to another reaction vessel and stirred at 500 rpm for 5 minutes at room temperature to obtain a curing agent. 100 kg of the base material and 31 kg of the additive were mixed and stirred at 500 rpm for 25 minutes at room temperature. Finally, 17 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0061] The above-mentioned coating is applied to the surface of the metal substrate by spraying, and cured at room temperature for 48 hours to obtain a coating film. The temperature is increased from room temperature to 500°C at a heating rate of 10°C / min, and maintained at 500±10°C for 4 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0062] Example 4

[0063] The anti-corrosion coating formula of the present invention is as follows:

[0064] Base material formula: 68kg of silicone hybrid epoxy resin, 2.5kg of n-butanol, 3kg of butyl acetate, 13.5kg of hollow glass microspheres, 9kg of titanium dioxide, 3.5kg of mica iron oxide, and 0.5kg of modified bentonite.

[0065] Additive formula: C9 aromatic resin 17kg, xylene 13kg, graphene oxide 0.7kg, fumed silica 1.8kg

[0066] Curing agent formula: 17kg of 3-aminopropyltriethylsilane and 1kg of n-butanol.

[0067] The preparation method of the anti-corrosion coating of the present invention:

[0068] 0.8 g of graphene oxide, 10 g of the silane coupling agent vinyltriethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 300 W for 20 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 60°C constant-temperature oil bath and stirred continuously for 18 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.25 μm and washed eight times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 55°C for 20 hours to obtain silane-modified graphene oxide.

[0069] 68 kg of organosilicon hybrid epoxy resin, 2.5 kg of n-butanol, 3 kg of butyl acetate, 13.5 kg of hollow glass microspheres, 9 kg of titanium dioxide, 3.5 kg of mica iron oxide, and 0.5 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 600 rpm for 25 minutes at room temperature to obtain a base material. 17 kg of C9 aromatic hydrocarbon resin, 13 kg of xylene, 0.7 kg of graphene oxide, and 1.8 kg of fumed silica were sequentially added to the vessel and stirred at 300 rpm in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 17 kg of 3-aminopropyltriethylsilane and 1 kg of n-butanol were sequentially added to another reaction vessel and stirred at 500 rpm for 5 minutes at room temperature to obtain a curing agent. 100 kg of the base material and 32.5 kg of the additive were mixed and stirred at 500 rpm for 25 minutes at room temperature. Finally, 18 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0070] The above-mentioned coating is applied to the surface of the metal substrate by spraying, cured at room temperature for 48 hours to obtain a coating film, and then heated from room temperature to 500°C at a heating rate of 10°C / min, and maintained at 500±10°C for 5 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0071] Example 5

[0072] The anti-corrosion coating formula of the present invention is as follows:

[0073] Base material formula: 60kg of silicone hybrid epoxy resin, 4kg of n-butanol, 3.5kg of butyl acetate, 15kg of hollow glass microspheres, 10.5kg of titanium dioxide, 6kg of mica iron oxide, and 1kg of modified bentonite.

[0074] Additive formula: C9 aromatic resin 14.5kg, xylene 14kg, graphene oxide 1kg, fumed silica 1.5kg

[0075] Curing agent formula: 15kg of 3-aminopropyltriethylsilane and 1kg of n-butanol.

[0076] The preparation method of the anti-corrosion coating of the present invention:

[0077] 0.9 g of graphene oxide, 9 g of the silane coupling agent γ-aminopropyltriethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 240 W for 30 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 60°C constant-temperature oil bath and stirred continuously for 15 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.25 μm and washed five times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 50°C for 12 hours to obtain silane-modified graphene oxide.

[0078] 60 kg of organosilicon hybrid epoxy resin, 4 kg of n-butanol, 3.5 kg of butyl acetate, 15 kg of hollow glass microspheres, 10.5 kg of titanium dioxide, 6 kg of micaceous iron oxide, and 1 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 600 rpm for 25 minutes at room temperature to obtain a base material. 14.5 kg of C9 aromatic hydrocarbon resin, 14 kg of xylene, 1 kg of graphene oxide, and 1.5 kg of fumed silica were sequentially added to the vessel and stirred at 300 rpm in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 15 kg of 3-aminopropyltriethylsilane and 1 kg of n-butanol were sequentially added to another reaction vessel and stirred at 500 rpm for 5 minutes at room temperature to obtain a curing agent. 100 kg of the base material and 31 kg of the additive were mixed and stirred at 500 rpm for 25 minutes at room temperature. Finally, 16 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0079] The above-mentioned coating was applied to the surface of the metal substrate by brushing, cured at room temperature for 36 hours to obtain a coating film, and then heated from room temperature to 500°C at a heating rate of 8°C / min and maintained at 500±10°C for 4.5 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0080] Example 6

[0081] The anti-corrosion coating formula of the present invention is as follows:

[0082] Base material formula: 70kg of silicone hybrid epoxy resin, 2.5kg of n-butanol, 3kg of butyl acetate, 10.5kg of hollow glass microspheres, 9kg of titanium dioxide, 4.5kg of mica iron oxide, and 0.5kg of modified bentonite.

[0083] Additive formula: C9 aromatic resin 15.5kg, xylene 13kg, graphene oxide 0.8kg, fumed silica 0.7kg

[0084] Curing agent formula: 17.5 kg of 3-aminopropyltriethylsilane and 1.5 kg of n-butanol.

[0085] The preparation method of the anti-corrosion coating of the present invention:

[0086] 0.75 g of graphene oxide, 10 g of the silane coupling agent γ-aminopropyltriethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 200 W for 25 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 60°C constant-temperature oil bath and stirred continuously for 15 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.25 μm and washed six times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 60°C for 16 hours to obtain silane-modified graphene oxide.

[0087] 70 kg of organosilicon hybrid epoxy resin, 2.5 kg of n-butanol, 3 kg of butyl acetate, 10.5 kg of hollow glass microspheres, 9 kg of titanium dioxide, 4.5 kg of mica iron oxide, and 0.5 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 500 rpm for 30 minutes at room temperature to obtain a base material. 15.5 kg of C9 aromatic resin, 13 kg of xylene, 0.8 kg of graphene oxide, and 0.7 kg of fumed silica were sequentially added to the vessel and stirred at 300 rpm in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 17.5 kg of 3-aminopropyltriethylsilane and 1.5 kg of n-butanol were sequentially added to another reaction vessel and stirred at 550 rpm for 5 minutes at room temperature to obtain a curing agent. 100 kg of the base material and 30 kg of the additive were mixed and stirred at 500 rpm for 25 minutes at room temperature. Finally, 19 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0088] The above-mentioned coating is applied to the surface of the metal substrate by spraying, cured at room temperature for 48 hours to obtain a coating film, and then heated from room temperature to 500°C at a heating rate of 10°C / min, and maintained at 500±10°C for 5 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0089] After the base material and additives are mixed and stirred, the curing agent should be added within 3 hours to prepare the coating. The effective use time after the three components are mixed shall not exceed 2 hours.

[0090] Comparative Example 1

[0091] The anti-corrosion coating formula of the present invention is as follows:

[0092] Base material formula: 60kg of silicone hybrid epoxy resin, 4kg of n-butanol, 3.5kg of butyl acetate, 15kg of hollow glass microspheres, 10.5kg of titanium dioxide, 6kg of mica iron oxide, and 1kg of modified bentonite.

[0093] Additive formula: xylene 14kg, graphene oxide 0.5kg, fumed silica 1.5kg

[0094] Curing agent formula: 15kg of 3-aminopropyltriethylsilane and 1kg of n-butanol.

[0095] The preparation method of the anti-corrosion coating of the present invention:

[0096] 0.9 g of graphene oxide, 9 g of the silane coupling agent γ-aminopropyltriethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 240 W for 30 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 60°C constant-temperature oil bath and stirred continuously for 15 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.25 μm and washed five times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 50°C for 12 hours to obtain silane-modified graphene oxide.

[0097] 60 kg of organosilicon hybrid epoxy resin, 4 kg of n-butanol, 3.5 kg of butyl acetate, 15 kg of hollow glass microspheres, 10.5 kg of titanium dioxide, 6 kg of micaceous iron oxide, and 1 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 600 rpm for 25 minutes at room temperature to obtain a base material. 14 kg of xylene, 0.5 kg of graphene oxide, and 1.5 kg of fumed silica were sequentially added to the vessel and stirred at 300 rpm in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 15 kg of 3-aminopropyltriethylsilane and 1 kg of n-butanol were sequentially added to another reaction vessel and stirred at 500 rpm for 5 minutes at room temperature to obtain a curing agent. 100 kg of the base material and 16 kg of the additive were mixed and stirred at 500 rpm for 25 minutes at room temperature. Finally, 16 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0098] The above-mentioned coating was applied to the surface of the metal substrate by brushing, cured at room temperature for 36 hours to obtain a coating film, and then heated from room temperature to 500°C at a heating rate of 8°C / min and maintained at 500±10°C for 4.5 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0099] Comparative Example 2

[0100] The anti-corrosion coating formula of the present invention is as follows:

[0101] Base material formula: 70kg of silicone hybrid epoxy resin, 2.5kg of n-butanol, 3kg of butyl acetate, 10.5kg of hollow glass microspheres, 9kg of titanium dioxide, 4.5kg of mica iron oxide, and 0.5kg of modified bentonite.

[0102] Additive formula: C9 aromatic resin 16.5kg, xylene 13kg, fumed silica 0.5kg

[0103] Curing agent formula: 17.5 kg of 3-aminopropyltriethylsilane and 1.5 kg of n-butanol.

[0104] The preparation method of the anti-corrosion coating of the present invention:

[0105] 0.75 g of graphene oxide, 10 g of the silane coupling agent γ-aminopropyltriethoxysilane, 10 g of deionized water, and 100 g of anhydrous ethanol were added to a container and ultrasonically treated at 200 W for 25 minutes to obtain a graphene oxide dispersion. The dispersion was then placed in a 60°C constant-temperature oil bath and stirred continuously for 15 hours to obtain a modified graphene oxide solution. The graphene solution was filtered through a microporous membrane with a pore size of 0.25 μm and washed six times with anhydrous ethanol. Finally, the modified graphene oxide wet cake was dried in a vacuum drying oven at 60°C for 16 hours to obtain silane-modified graphene oxide.

[0106] 70 kg of organosilicon hybrid epoxy resin, 2.5 kg of n-butanol, 3 kg of butyl acetate, 10.5 kg of hollow glass microspheres, 9 kg of titanium dioxide, 4.5 kg of mica iron oxide, and 0.5 kg of modified bentonite were sequentially added to a reaction vessel and stirred at 500 r / min at room temperature for 30 minutes to obtain a base material. 16.5 kg of C9 aromatic hydrocarbon resin, 13 kg of xylene, and 0.5 kg of fumed silica were sequentially added to the vessel and stirred at 300 r / min in an 80°C constant temperature oil bath for 1 hour to obtain an additive. 17.5 kg of 3-aminopropyltriethylsilane and 1.5 kg of n-butanol were sequentially added to another reaction vessel and stirred at 550 r / min at room temperature for 5 minutes to obtain a curing agent. 100 kg of the base material and 30 kg of the additive were mixed and stirred at 500 r / min at room temperature for 25 minutes. Finally, 19 kg of curing agent was added and mixed, and stirred at a speed of 500 r / min at room temperature for 10 minutes to obtain a graphene high-temperature resistant and anti-corrosion coating.

[0107] The above-mentioned coating is applied to the surface of the metal substrate by spraying, cured at room temperature for 48 hours to obtain a coating film, and then heated from room temperature to 500°C at a heating rate of 10°C / min, and maintained at 500±10°C for 5 hours to obtain a gradient-distributed high-temperature resistant anti-corrosion coating.

[0108] After the base material and additives are mixed and stirred, the curing agent should be added within 3 hours to prepare the coating. The effective use time after the three components are mixed shall not exceed 2 hours.

[0109] The various properties of the new high-temperature resistant anti-corrosion coating are shown in Table 1 below.

[0110] Table 1 Test results of various properties of new high temperature resistant anticorrosion coating

[0111]

[0112]

[0113]

[0114] In summary, as shown in Table 1, comparing the Examples and Comparative Examples, the addition of C9 aromatic resin and graphene oxide as additives to the coating not only improves various mechanical properties of the coating but also significantly enhances its heat and corrosion resistance. This is due to the fact that the C9 aromatic resin forms a gradient-distributed protective layer during the high-temperature curing process, while the graphene connects the aromatic resin to the matrix resin, creating a good connection and enhancing protection for the aromatic resin. This improves both the high-temperature resistance and the corrosion resistance of the coating. Figure 1 Schematic diagram of coating curing in a comparative example without adding aromatic hydrocarbon resin and graphene; Figure 2 The schematic diagram of the curing of the coating in which aromatic hydrocarbon resin and graphene are added in the present invention shows that during the curing process, the aromatic hydrocarbon resin forms a gradient distribution protective layer on the surface of the coating, and the graphene strengthens the interface connection between the aromatic hydrocarbon resin and the matrix resin.

[0115] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of their technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a graphene-modified gradient-distributed high-temperature resistant anti-corrosion coating, characterized in that: The steps include: Step 1: adding graphene oxide, anhydrous ethanol and a silane coupling agent to deionized water, and ultrasonically treating them at a power of 100-300 W for 10-30 minutes to obtain a graphene oxide dispersion; then placing the dispersion in a constant temperature oil bath at 50-80° C. and continuously stirring for 12-24 hours to obtain a modified graphene oxide solution; filtering the modified graphene oxide solution through a microporous membrane with a pore size of 0.25-0.5 μm, and washing it with anhydrous ethanol for 5-10 times, and finally drying the modified graphene oxide wet cake in a vacuum drying oven at 40-60° C. for 5-10 hours to obtain silane-modified graphene oxide; Step 2: adding the silane-modified graphene oxide to a xylene solution and treating it under ultrasonication at a power of 100-300 W for 0.5 hour to obtain a graphene oxide dispersion, then adding aromatic hydrocarbon resin and oleophilic fumed silica, and continuously stirring at a speed of 300-600 rpm in a constant temperature oil bath at 50-80° C. for 0.5-2 hours to obtain a graphene thermoplastic resin additive; Step 3: Mix the components of the organosilicon hybrid epoxy resin base material, and continuously stir at a speed of 300-600 rpm for 15-60 minutes at room temperature to obtain a base material; Step 4: Mix the graphene thermoplastic resin additive with the base material, stir continuously at a speed of 300-600 r / min at room temperature for 15-60 minutes, finally add the components of the aminosilane curing agent, and stir continuously at a speed of 300-600 r / min at room temperature for 15-30 minutes to obtain a high temperature resistant anti-corrosion coating; Step 5: Apply the above-mentioned high-temperature resistant anti-corrosion coating on the substrate, dry it at room temperature for 12 to 60 hours to form a cured coating film, then increase the temperature from room temperature to 400 to 700°C at a heating rate of 3 to 15°C / min, and maintain it at 400 to 700±10°C for 2 to 8 hours to obtain a gradient distribution high-temperature resistant anti-corrosion coating; The anti-corrosion coating comprises a graphene thermoplastic resin additive, an organosilicon hybrid epoxy resin base material and an aminosilane curing agent; the mass fractions of the graphene thermoplastic resin additive components are: 45-59 parts of xylene, 40-50 parts of aromatic hydrocarbon resin, 0.05-1 part of silane-modified graphene oxide, and 0.5-2.5 parts of oleophilic fumed silica; The mass fractions of the organosilicon hybrid epoxy resin base components are: 50-80 parts of organosilicon hybrid epoxy resin, 1-5 parts of n-butanol, 1-5 parts of butyl acetate, 5-20 parts of hollow glass microspheres, 3-15 parts of titanium dioxide, 3-15 parts of mica iron oxide, and 0.5-8 parts of modified bentonite; The mass fractions of the aminosilane curing agent components are: 1-5 parts of n-butanol, 1-5 parts of butyl acetate, and 90-98 parts of aminosilane coupling agent.

2. The preparation method according to claim 1, characterized in that In step 4, the amount of the graphene thermoplastic resin additive is 20% to 40% of the base material.

3. The preparation method according to claim 1, characterized in that The amount of the graphene thermoplastic resin additive in step 4 is 25% to 35% of the base material.

4. The preparation method according to claim 1, characterized in that In step 4, the amount of aminosilane curing agent should be 22.5% to 30% of the base material.

5. The preparation method according to claim 1, characterized in that The graphene oxide described in step 1 is lightly oxidized graphene, having 1 to 5 layers, a transverse equivalent diameter of the sheet in the range of 0.5 to 5 μm, and an oxygen-containing group selected from one or a combination of hydroxyl, carboxyl, and epoxy groups, with an oxygen-carbon ratio in the range of 0.1 to 2; the silane coupling agent is selected from one or any combination of γ-aminopropyltriethoxysilane, vinyltriethoxysilane, and γ-glycidyloxypropyltrimethoxysilane.

6. The preparation method according to claim 4, characterized in that In step 1, the amount of graphene oxide used is 0.1% to 1% of the amount of anhydrous ethanol used; the amount of silane coupling agent used is 0.1% to 10% of the amount of anhydrous ethanol used; and the amount of water used is 5% to 100% of the amount of anhydrous ethanol used.

7. The preparation method according to claim 6, characterized in that In step 2, the aromatic hydrocarbon resin includes one or more mixed resins selected from C5 aliphatic petroleum resin, C9 aromatic petroleum resin, DCPD cycloaliphatic diene resin, hydrogenated petroleum resin, and condensed polynuclear aromatic hydrocarbon resin; the primary particle size of the oleophilic fumed silica is 10 to 40 nm, and the surface-grafted modifier includes one or more combinations of the following: polydimethylsiloxane, dimethyldichlorosilane, hexamethyldisilazane, γ-aminopropyltriethoxysilane, and trimethoxypropylaminosilane.

8. Graphene modified gradient distribution high temperature resistant anti-corrosion coating, characterized in that: The anti-corrosion coating is prepared by any one of the methods described in claims 1-7.

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