A graphene super-weather-resistant powder coating for offshore photovoltaic support and preparation method thereof

Abstract

The invention provides a graphene super-weather-resistant powder coating for an offshore photovoltaic support and a preparation method thereof. The raw materials of the powder coating include modified graphene, carboxyl saturated polyester, triglycidyl isocyanurate, a leveling agent, a defoamer, a brightener, a pigment filler, gas-phase nano-silica and a special functional additive. The modified graphene is silane-modified nitrogen-sulfur-doped graphene, so that the graphene can have excellent dispersibility, hardness and wear resistance in the coating, thereby improving various properties of the coating. The special functional additive is magnesia feldspar Ca2MgSi2O7, which can not only improve the surface hardness and wear resistance of the coating, but also improve the optical transparency and reflective performance of the coating, effectively ensuring the stability of the coating system under strong ultraviolet radiation. The powder coating can better meet the anti-corrosion requirements of offshore operating conditions of photovoltaic supports and has strong weather resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a graphene super-weather-resistant powder coating for an offshore photovoltaic support and a preparation method thereof. Background Art

[0002] Photovoltaic power generation has significant economic benefits, is efficient and environmentally friendly, and is one of the highest quality green energy sources. Compared with terrestrial photovoltaics, marine photovoltaics have natural environmental advantages. The water surface is open and there are no obstructions. The sunshine is long and fully utilized, which can significantly increase power generation. Offshore photovoltaic systems are exposed to seawater, humid air, and sun and rain for a long time. The chloride ions in seawater and the salt and humidity in humid air are highly corrosive to metal materials, especially for commonly used metals such as steel and aluminum, which can easily cause surface corrosion and rust. Long-term ultraviolet radiation and marine climate conditions (such as humidity and high temperature) will also accelerate material aging and corrosion. Therefore, it is of great significance to study the anti-corrosion technology of offshore photovoltaic brackets to extend their service life and reduce maintenance costs and energy losses.

[0003] Traditional anti-corrosion methods such as galvanizing or simple painting have limited durability and effectiveness in offshore environments, especially after long-term exposure, the coating is prone to damage, rust and other problems. Combining the galvanized layer with the weather-resistant powder coating has the following advantages: the galvanized layer acts as the first line of protection, providing physical isolation and anti-corrosion functions, while the weather-resistant powder coating forms a chemical protective layer on its surface, enhancing the corrosion resistance and weather resistance. Weather-resistant powder coating has excellent weather resistance and can resist ultraviolet rays, salt spray and humidity for a long time. It also provides a variety of color options to meet the needs of photovoltaic brackets for aesthetic design. Researchers are committed to optimizing the formulation of the coating and selecting more weather-resistant and environmentally friendly materials to improve the long-term stability and performance of the coating in the offshore environment. Therefore, it is of great significance to develop a super-weather-resistant powder coating for offshore photovoltaic brackets. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the present invention proposes a graphene super-weather-resistant powder coating for offshore photovoltaic brackets and a preparation method thereof.

[0005] The technical solution of the present invention is achieved in this way:

[0006] A graphene super-weatherproof powder coating for an offshore photovoltaic support, comprising the following components by weight: 4-8 parts of modified graphene, 55-60 parts of carboxyl saturated polyester, 3-6 parts of triglycidyl isocyanurate, 2-4 parts of a leveling agent, 0.2-0.5 parts of a defoaming agent, 0.5-1 parts of a brightener, 3-8 parts of a pigment filler, 0.1-0.3 parts of fumed nano-silicon dioxide, and 2-5 parts of a special functional additive; the modified graphene is silane-modified nitrogen-sulfur-doped graphene; the special functional additive is magnesia feldspar Ca2MgSi2O7;

[0007] The preparation method of the modified graphene is:

[0008] (1) dispersing graphene oxide in ethanol, adding silicon dioxide, ultrasonicating, removing ethanol to obtain a solid, mixing and grinding with a nitrogen-containing compound and a sulfur-containing compound, calcining under an inert gas atmosphere, soaking in hydrofluoric acid, centrifugally washing, and drying to obtain nitrogen-sulfur doped graphene; the nitrogen-containing compound is melamine; the sulfur-containing compound is dibenzothiazole disulfide; the mass ratio of the solid, melamine, and dibenzothiazole disulfide is 2:1:1;

[0009] (2) Dispersing nitrogen-sulfur doped graphene in a solvent, adding phenyltrimethoxysilane, mixing, reacting at 60-80°C for 6-8h, cooling to room temperature, filtering, washing, and drying to obtain modified graphene.

[0010] Preferably, the solvent (1) is ethanol; the solvent (2) is N,N-dimethylformamide, and the material-liquid ratio of nitrogen-sulfur-doped graphene to the solvent is 1 g / 50 mL.

[0011] Melamine, as a nitrogen-containing compound, can not only improve the thermal stability and mechanical strength of graphene, but also enhance the adhesion between graphene and the metal substrate, forming a stronger and more durable protective layer, effectively preventing oxidation and corrosion of the metal surface. Dibenzothiazyl disulfide, as a sulfide, can undergo a sulfurization reaction with the graphene surface, improving the adhesion and wear resistance of graphene and enhancing the durability of the coating. Phenyltrimethoxysilane is a compound containing a silane group, which can improve the dispersibility and wettability of graphene in the coating material, thereby enhancing the interfacial bonding strength between graphene and the substrate, and further improving the mechanical properties and chemical resistance of the coating.

[0012] Preferably, the carboxyl saturated polyester is of model PC-6620; the leveling agent is of model PV88; the defoaming agent is benzoin; the brightener is of model 701; the pigments and fillers are titanium dioxide and carbon black; and the fumed nano-silica is of model Cabot CAB-O-SIL M-5.

[0013] Preferably, the mass ratio of the titanium dioxide to carbon black is 100:1.

[0014] The present invention also provides a method for preparing a graphene super-weather-resistant powder coating for an offshore photovoltaic support, comprising the following steps:

[0015] (1) Weigh the required materials by weight, place them in a vertical mixer, mix them thoroughly, and crush them to obtain a uniformly mixed premixed material;

[0016] (2) heating and extruding the premixed material through a twin-screw extruder;

[0017] (3) The extruded product is crushed and ground to obtain powder coating.

[0018] Preferably, the jacket temperature of the twin-screw extruder is 110-120° C., and the rotation speed is 500-1200 rpm.

[0019] Preferably, the powder coating has a particle size of less than 100 microns.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention provides a graphene super-weather-resistant powder coating for offshore photovoltaic brackets, comprising modified graphene, carboxyl saturated polyester, triglycidyl isocyanurate, leveling agent, defoaming agent, brightener, pigment filler, gas-phase nano-silica and special functional additives. The powder coating can better meet the anti-corrosion requirements of offshore operating conditions, has strong anti-salt spray corrosion performance, and can play a better protective role for photovoltaic brackets in coastal areas. The raw materials of the coating of the present invention are easy to obtain and the preparation method is simple.

[0022] (2) The present invention provides a graphene super-weather-resistant powder coating for offshore photovoltaic brackets, wherein the modified graphene is modified by the combination of phenyltrimethoxysilane, melamine and dibenzothiazole disulfide so that the graphene in the coating can simultaneously have excellent dispersibility, hardness, wear resistance, conductivity and weather resistance, thereby improving various properties of the coating.

[0023] (3) The present invention provides a graphene super-weather-resistant powder coating for offshore photovoltaic brackets, wherein the special functional additive Ca2MgSi2O7 has high hardness, wear resistance and high chemical stability. Adding it to the coating can significantly improve the surface hardness and wear resistance of the coating, making the coating more durable. It has a special crystal structure, which can improve the optical transparency and reflective properties of the coating, and effectively ensure the stability of the coating system under strong ultraviolet radiation. DETAILED DESCRIPTION

[0024] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0025] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0026] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0027] The brightener was 701 wetting promoter (brightener), purchased from Huangshan Jinfeng Industrial Co., Ltd.

[0028] Example 1

[0029] A graphene super-weather-resistant powder coating for an offshore photovoltaic support comprises the following components, measured by weight: 6 parts of modified graphene, 60 parts of carboxyl saturated polyester PC-6620, 5 parts of triglycidyl isocyanurate (TGIC), 3 parts of leveling agent PV88, 0.4 parts of benzoin (defoaming agent), 0.8 parts of brightener 701, 5 parts of pigments and fillers, 0.2 parts of fumed nano-silica (Cabot CAB-O-SIL M-5), and 4 parts of magnesia feldspar Ca2MgSi2O7 (functional additive); wherein the pigments and fillers are titanium dioxide and carbon black, and the mass ratio of titanium dioxide to carbon black is 100:1.

[0030] The preparation method of the modified graphene is:

[0031] (1) 2 g of graphene oxide was dispersed in 3 L of ethanol, 6 g of silicon dioxide was added, and the mixture was thoroughly sonicated. After the ethanol was removed by rotary evaporation, 8 g of solid was obtained, which was mixed and ground with 4 g of melamine and 4 g of dibenzothiazole disulfide. The mixture was calcined at 800 °C for 2 h in a nitrogen atmosphere, and then immersed in hydrofluoric acid, washed by centrifugation, and dried at 80 °C for 12 h to obtain nitrogen-sulfur doped graphene.

[0032] (2) The nitrogen-sulfur doped graphene was dispersed in N,N-dimethylformamide at a solid-liquid ratio of 1 g / 50 mL, 1 g of phenyltrimethoxysilane was added, mixed, reacted at 80 °C for 6 h, cooled to room temperature, filtered, washed, and dried at 80 °C for 12 h to obtain modified graphene.

[0033] The method for preparing the graphene super-weather-resistant powder coating for offshore photovoltaic brackets comprises the following steps:

[0034] (1) Weigh the required materials by weight, place them in a vertical mixer, mix for 120 seconds, and crush for 120 seconds to obtain a uniformly mixed premixed material;

[0035] (2) heating and extruding the premixed material through a twin-screw extruder, wherein the jacket temperature of the twin-screw extruder is 120° C. and the rotation speed is 800 rpm;

[0036] (3) The extruded product is crushed and ground to obtain a powder coating with a particle size of less than 100 microns.

[0037] Example 2

[0038] A graphene super-weather-resistant powder coating for an offshore photovoltaic support comprises the following components, measured by weight: 8 parts of modified graphene, 55 parts of carboxyl saturated polyester, 3 parts of triglycidyl isocyanurate, 4 parts of leveling agent PV88, 0.2 parts of benzoin (defoaming agent), 0.5 parts of brightener 701, 8 parts of pigments and fillers, 0.3 parts of fumed nano-silica (Cabot CAB-O-SIL M-5), and 2 parts of magnesia feldspar Ca2MgSi2O7 (functional additive); wherein the pigments and fillers are titanium dioxide and carbon black, and the mass ratio of titanium dioxide to carbon black is 100:1.

[0039] The preparation method of the modified graphene is:

[0040] (1) 2 g of graphene oxide was dispersed in 3 L of ethanol, 6 g of silicon dioxide was added, and the mixture was thoroughly sonicated. After the ethanol was removed by rotary evaporation, 8 g of solid was obtained, which was mixed and ground with 4 g of melamine and 4 g of dibenzothiazole disulfide. The mixture was calcined at 800 °C for 2 h in a nitrogen atmosphere, and then immersed in hydrofluoric acid, washed by centrifugation, and dried at 80 °C for 12 h to obtain nitrogen-sulfur doped graphene.

[0041] (2) The nitrogen-sulfur doped graphene was dispersed in N,N-dimethylformamide at a solid-liquid ratio of 1 g / 50 mL, 1 g of phenyltrimethoxysilane was added, mixed, reacted at 60 °C for 8 h, cooled to room temperature, filtered, washed, and dried at 80 °C for 12 h to obtain modified graphene.

[0042] The method for preparing the graphene super-weather-resistant powder coating for offshore photovoltaic brackets comprises the following steps:

[0043] (1) Weigh the required materials by weight, place them in a vertical mixer, mix for 120 seconds, and crush for 120 seconds to obtain a uniformly mixed premixed material;

[0044] (2) heating and extruding the premixed material through a twin-screw extruder, wherein the jacket temperature of the twin-screw extruder is 120° C. and the rotation speed is 500 rpm;

[0045] (3) The extruded product is crushed and ground to obtain a powder coating with a particle size of less than 100 microns.

[0046] Example 3

[0047] A graphene super-weather-resistant powder coating for an offshore photovoltaic support comprises the following components, measured by weight: 4 parts of modified graphene, 60 parts of carboxyl saturated polyester, 6 parts of triglycidyl isocyanurate, 2 parts of leveling agent PV88, 0.5 parts of benzoin (defoaming agent), 1 part of brightener 701, 3 parts of pigments and fillers, 0.1 parts of fumed nano-silica (Cabot CAB-O-SIL M-5), and 5 parts of magnesia feldspar Ca2MgSi2O7 (functional additive); wherein the pigments and fillers are titanium dioxide and carbon black, and the mass ratio of titanium dioxide to carbon black is 100:1.

[0048] The preparation method of the modified graphene is:

[0049] (1) 2 g of graphene oxide was dispersed in 3 L of ethanol, 6 g of silicon dioxide was added, and the mixture was thoroughly sonicated. After the ethanol was removed by rotary evaporation, 8 g of solid was obtained, which was mixed and ground with 4 g of melamine and 4 g of dibenzothiazole disulfide. The mixture was calcined at 800 °C for 2 h in a nitrogen atmosphere, and then immersed in hydrofluoric acid, washed by centrifugation, and dried at 80 °C for 12 h to obtain nitrogen-sulfur doped graphene.

[0050] (2) The nitrogen-sulfur doped graphene was dispersed in N,N-dimethylformamide at a solid-liquid ratio of 1 g / 50 mL, 1 g of phenyltrimethoxysilane was added, mixed, reacted at 80 °C for 8 h, cooled to room temperature, filtered, washed, and dried at 80 °C for 12 h to obtain modified graphene.

[0051] The method for preparing the graphene super-weather-resistant powder coating for offshore photovoltaic brackets comprises the following steps:

[0052] (1) Weigh the required materials by weight, place them in a vertical mixer, mix for 120 seconds, and crush for 120 seconds to obtain a uniformly mixed premixed material;

[0053] (2) heating and extruding the premixed material through a twin-screw extruder, wherein the jacket temperature of the twin-screw extruder is 110° C. and the rotation speed is 1200 rpm;

[0054] (3) The extruded product is crushed and ground to obtain a powder coating with a particle size of less than 100 microns.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 1 is that the modified graphene in this example is replaced by ordinary graphene. The remaining ingredients and the preparation method of the graphene super-weather-resistant powder coating for offshore photovoltaic brackets are the same as those in Example 1.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 1 is that silicon dioxide is not added in the preparation method of modified graphene for sufficient ultrasound treatment. The preparation method of the modified graphene is:

[0059] (1) 2 g of graphene oxide was mixed with 4 g of melamine and 4 g of dibenzothiazole disulfide and ground, and calcined at 800 °C for 2 h in a nitrogen atmosphere to obtain nitrogen-sulfur doped graphene;

[0060] (2) The nitrogen-sulfur doped graphene was dispersed in N,N-dimethylformamide at a solid-liquid ratio of 1 g / 50 mL, 1 g of phenyltrimethoxysilane was added, mixed, reacted at 80 °C for 8 h, cooled to room temperature, filtered, washed, and dried at 80 °C for 12 h to obtain modified graphene.

[0061] The remaining ingredients and the preparation method of the graphene super weather-resistant powder coating for offshore photovoltaic support are the same as those in Example 1.

[0062] Comparative Example 3

[0063] The difference between this comparative example and Example 1 is that in the preparation process of the modified graphene in this example, dibenzothiazole disulfide is replaced by dibenzyl disulfide. The preparation method of the modified graphene in this example is as follows: (1) 2 g of graphene oxide is dispersed in 3 L of ethanol, 6 g of silicon dioxide is added, and the ethanol is removed by full ultrasonication and rotary evaporation to obtain 8 g of solid, which is mixed with 4 g of melamine and 4 g of dibenzyl disulfide and ground, calcined at 800° C. for 2 h under a nitrogen atmosphere, and then immersed in hydrofluoric acid, washed by centrifugation, and dried at 80° C. for 12 h to obtain nitrogen-sulfur doped graphene;

[0064] (2) The nitrogen-sulfur doped graphene was dispersed in N,N-dimethylformamide at a solid-liquid ratio of 1 g / 50 mL, 1 g of phenyltrimethoxysilane was added, mixed, reacted at 80 °C for 8 h, cooled to room temperature, filtered, washed, and dried at 80 °C for 12 h to obtain modified graphene.

[0065] The remaining ingredients and the preparation method of the graphene super weather-resistant powder coating for offshore photovoltaic support are the same as those in Example 1.

[0066] Comparative Example 4

[0067] The difference between this comparative example and Example 1 is that the graphene super weather-resistant powder coating used for offshore photovoltaic brackets in this example does not contain magnesia feldspar Ca2MgSi2O7.

[0068] The remaining ingredients and the preparation method of the graphene super weather-resistant powder coating for offshore photovoltaic support are the same as those in Example 1.

[0069] Test example

[0070] The graphene super-weather-resistant powder coatings for offshore photovoltaic brackets obtained in Examples 1-3 of the present invention and Comparative Examples 1-4 were sprayed on the surface of photovoltaic brackets in coastal areas (the substrate was oil-free and rust-free cold-rolled steel plate) to form a coating with a coating thickness of 50 um for performance testing. The performance testing method and evaluation criteria are as follows:

[0071] The adhesion of powder coatings refers to GB / T 5210-2006;

[0072] The impact resistance of powder coatings refers to GB / T 1732-2020;

[0073] The neutral salt spray and acid salt spray resistance of powder coatings refer to IEC 60068-2-52;

[0074] The moisture and heat resistance of powder coatings shall refer to GB / T 1740-2007;

[0075] The QUV UV aging resistance of powder coatings shall refer to GB / T 1865-2009;

[0076] The seawater resistance test of powder coatings refers to ISO 12944-9;

[0077] Acid resistance (5% hydrochloric acid) of powder coatings refers to GB / T 9274-1988;

[0078] The alkali resistance (5% sodium hydroxide) of powder coatings refers to GB / T 9274-1988; the test results are shown in Table 1:

[0079] Table 1 Performance test data of the graphene super-weather-resistant powder coating for offshore photovoltaic brackets according to the present invention

[0080]

[0081] It can be seen from the above table that the graphene super weather-resistant powder coatings for offshore photovoltaic supports prepared in Examples 1-3 of the present invention have excellent indicators. Compared with the test results of Comparative Examples 1-4, it can be seen that the graphene material is jointly modified by phenyltrimethoxysilane, melamine and dibenzothiazole disulfide so that the modified graphene and the functional additive magnesia feldspar Ca2MgSi2O7 work synergistically, which together improve the various properties of the coating and enhance the weather resistance of the coating. The graphene super weather-resistant powder coating for offshore photovoltaic supports provided by the present invention has excellent performance in acid salt spray resistance, moisture and heat resistance, QUV ultraviolet light aging resistance, seawater resistance, acid resistance and alkali resistance, can better meet the anti-corrosion requirements of offshore operating conditions, and can provide better protection for photovoltaic supports in coastal areas.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A graphene super-weather-resistant powder coating for offshore photovoltaic brackets, characterized in that: The invention comprises the following components by weight: 4-8 parts of modified graphene, 55-60 parts of carboxyl saturated polyester, 3-6 parts of triglycidyl isocyanurate, 2-4 parts of leveling agent, 0.2-0.5 parts of defoamer, 0.5-1 parts of brightener, 3-8 parts of pigment filler, 0.1-0.3 parts of fumed nano-silicon dioxide, and 2-5 parts of special functional additives; the modified graphene is silane-modified nitrogen-sulfur-doped graphene; the special functional additive is magnesia feldspar Ca2MgSi2O7; The preparation method of the modified graphene is: (1) dispersing graphene oxide in a solvent, adding silicon dioxide, ultrasonicating, removing the solvent to obtain a solid, mixing and grinding with a nitrogen-containing compound and a sulfur-containing compound, calcining under an inert gas atmosphere, soaking in hydrofluoric acid, centrifugally washing, and drying to obtain nitrogen-sulfur doped graphene; the sulfur-containing compound is dibenzothiazole disulfide; the mass ratio of the solid, melamine, and dibenzothiazole disulfide is 2:1:1; (2) Dispersing nitrogen-sulfur doped graphene in a solvent, adding phenyltrimethoxysilane, mixing, reacting at 60-80°C for 6-8h, cooling to room temperature, filtering, washing, and drying to obtain modified graphene.

2. The graphene super-weather-resistant powder coating for offshore photovoltaic bracket according to claim 1, characterized in that: The solvent of (1) is ethanol; the solvent of (2) is N,N-dimethylformamide, and the material-liquid ratio of nitrogen-sulfur doped graphene to the solvent is 1 g / 50 mL.

3. The graphene super-weather-resistant powder coating for offshore photovoltaic support according to claim 1, characterized in that: The model of the carboxyl saturated polyester is PC-6620; the model of the leveling agent is PV88; the defoaming agent is benzoin; the model of the brightener is 701; the pigments and fillers are titanium dioxide and carbon black; and the model of the fumed nano-silica is Cabot CAB-O-SIL M-5.

4. The graphene super-weather-resistant powder coating for offshore photovoltaic bracket according to claim 3, characterized in that: The mass ratio of the titanium dioxide to the carbon black is 100:

1.

5. A method for preparing a graphene super-weather-resistant powder coating for an offshore photovoltaic support according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) Weigh the required materials by weight, place them in a vertical mixer, mix them thoroughly, and crush them to obtain a uniformly mixed premixed material; (2) heating and extruding the premixed material through a twin-screw extruder; (3) The extruded product is crushed and ground to obtain powder coating.

6. The method for preparing a graphene super-weather-resistant powder coating for an offshore photovoltaic support according to claim 5, characterized in that: The jacket temperature of the twin-screw extruder is 110-120° C., and the rotation speed is 500-1200 rpm.

7. The method for preparing a graphene super-weather-resistant powder coating for an offshore photovoltaic support according to claim 5, characterized in that: The particle size of the powder coating is less than 100 microns.

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