Antistatic coating and preparation method thereof

Abstract

The present invention belongs to the technical field of coatings, and specifically relates to an antistatic coating and a preparation method thereof. The coating of the present invention comprises an epoxy resin added with modified graphene; the epoxy resin added with modified graphene is prepared by uniformly mixing modified graphene, epoxy resin, and ethyl acetate, and then adding styrene and an initiator for heating reaction. The present invention adds modified graphene to the epoxy resin, which not only improves the antistatic ability of the coating, but also improves the comprehensive performance of the antistatic coating, such as wear resistance and impact resistance; the preparation method of the present invention is simple, and the obtained antistatic coating has excellent conductivity and can be widely used in various antistatic fields.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to an antistatic coating and a preparation method thereof. Background Art

[0002] Static electricity is an objective natural phenomenon. The generation, accumulation and discharge of static electricity can cause troubles and even disasters to human production and life. Therefore, in order to maintain a good and clean working environment, anti-static coatings are often used in marine ships, petrochemicals, semiconductors, textiles, rubber and other fields to protect industrial equipment and ensure the safety of construction workers.

[0003] Current antistatic coatings are usually made by adding conductive materials such as metal powder, carbon materials or metal oxides to non-conductive film-forming resins, but the coatings have problems such as low conductivity and poor adhesion. 2 The two-dimensional single atomic layer structure of carbon atoms composed of a honeycomb lattice has a large specific surface area and structural stability. Its excellent conductivity and ultra-high strength make it a potential application prospect as a functional material in anti-static coatings.

[0004] The Chinese patent application document with publication number CN106189683A discloses a graphene-modified epoxy resin antistatic coating, which improves the conductivity, wear resistance, corrosion resistance and other properties of the antistatic coating by adding graphene to the coating. However, graphene has strong attraction and van der Waals force between molecules in the solvent, and its conjugated structure makes it easy to agglomerate in the solvent and difficult to disperse evenly, which has certain limitations in practical applications. Summary of the invention

[0005] The graphene in the existing antistatic coating has low dispersibility and is easy to agglomerate, which affects the conductivity. In order to solve this problem, the present invention provides an antistatic coating.

[0006] In order to achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides an antistatic coating, which includes an epoxy resin added with modified graphene; the epoxy resin added with modified graphene is prepared by uniformly mixing modified graphene, epoxy resin, and ethyl acetate, and then adding styrene and an initiator to heat and react.

[0008] Preferably, in terms of mass ratio, modified graphene: epoxy resin = 1: 20-30, styrene: modified graphene: initiator = 65-75: 2-6: 1; reaction temperature is 65-75°C, reaction time is 20-26h; wherein the initiator is azobisisobutyronitrile. Too high a content of modified graphene is prone to local concentration, increased agglomeration, and reduced comprehensive performance of the antistatic coating.

[0009] Preferably, the modified graphene is prepared by using graphene oxide as a raw material, preparing the modified graphene oxide by a template method, then sequentially modifying it with p-phenylenediamine and nanosilver, and finally reducing it with a reducing agent.

[0010] Preferably, the modified graphene preparation method is as follows:

[0011] (1) Preparation of modified graphene oxide

[0012] Styrene, graphene oxide, anhydrous ethanol, an initiator, an emulsifier, a stabilizer and ethylene glycol dimethacrylate are ultrasonically dispersed under anaerobic conditions and heated for reaction; after the reaction, the product is filtered and washed, and then immersed in an alkaline aqueous solution, washed with water, and then immersed in toluene, centrifuged, and repeated 2-3 times, and washed with anhydrous ethanol and dried to obtain modified graphene oxide;

[0013] (2) Preparation of organically modified graphene oxide

[0014] Dispersing the modified graphene oxide in water, adjusting the pH, stirring and heating, adding p-phenylenediamine to react, filtering, and washing to obtain organic modified graphene oxide;

[0015] (3) Preparation of modified graphene

[0016] The organic modified graphene oxide is dispersed in water, polypropylene pyrrolidone is added and mixed evenly, a silver nitrate aqueous solution is slowly added dropwise for reaction, and then a reducing agent is added for reflux reaction, and the modified graphene is obtained through centrifugation, washing and drying.

[0017] Preferably, in (1), the initiator is azobisisobutyronitrile, the emulsifier is sodium dodecyl sulfate, the stabilizer is polyvinyl pyrrolidone, and the alkaline aqueous solution is sodium hydroxide aqueous solution or potassium hydroxide aqueous solution; in (3), the reducing agent is a mixed solution of ammonia water and hydrazine hydrate.

[0018] Preferably, the (1) is specifically:

[0019] (1a) adding part of styrene to a dispersion of graphene oxide, anhydrous ethanol, initiator, emulsifier and stabilizer for a reaction time of 0.5-2 h;

[0020] (1b) adding ethylene glycol dimethacrylate and the remaining styrene again and continuing the reaction for 10-14 hours;

[0021] The partial styrene accounts for 50%-60% of the total mass of the styrene; adding styrene twice can make the polystyrene grow secondary, and the polystyrene is interspersed between the graphene oxide sheets, effectively improving the problem of graphene oxide agglomeration.

[0022] Since the dispersibility of graphene oxide is better than that of graphene, the present invention first modifies the graphene oxide and uses its own good dispersibility to react with polystyrene, p-phenylenediamine, etc.; then, since the conductivity of graphene is stronger than that of graphene oxide, the modified graphene oxide is reduced to modified graphene again and dispersed in epoxy resin, which can improve the dispersibility of graphene and the conductivity of the antistatic coating.

[0023] Preferably, in (1), by mass ratio, styrene: graphene oxide = 60-80:1, styrene: stabilizer: initiator = 50-60:2-8:1, and the remaining styrene: ethylene glycol dimethacrylate = 55-60:1; the reaction temperature is 70-80°C.

[0024] Preferably, in (2), the mass ratio of modified graphene oxide to p-phenylenediamine is 1:8-12; the pH value is 9-10; the reaction temperature is 85-100°C, and the reaction time is 2-4h.

[0025] Preferably, in (3), the mass ratio of organically modified graphene oxide: silver nitrate: polyvinyl pyrrolidone is 1:0.5-2:5-12; the mass ratio of organically modified graphene oxide: ammonia water: hydrazine hydrate is 1 g: 15-35 mL: 2-6 mL; and the reaction temperature is 30-50°C.

[0026] In a second aspect, the present invention provides a method for preparing the above-mentioned antistatic coating, comprising the following steps:

[0027] (1) Weigh 1-3 parts by mass of epoxy resin curing agent and 10-20 parts by mass of solvent, stir evenly to obtain a curing agent solution;

[0028] (2) Weigh 30-50 parts by weight of epoxy resin to which modified graphene is added and 40-60 parts by weight of solvent, stir them evenly, then add the curing agent solution, stir them evenly again, and obtain an antistatic coating.

[0029] Application of the antistatic coating: the antistatic coating is evenly coated on the surface of the material and cured under appropriate conditions.

[0030] The epoxy resin described in the present invention can be any epoxy resin commonly used in coatings without any particular limitation, such as epoxy resin E-51, E-44, E-12, etc.; the curing agent described in the present invention can be any epoxy resin curing agent commonly used in coatings without any particular limitation, such as amine curing agents, etc.; the solvent described in the present invention can be any solvent commonly used in coatings without any particular limitation, such as toluene, xylene, etc.

[0031] The antistatic coating of the present invention may further contain other auxiliary agents, such as dispersants, defoamers, wetting agents, etc., without particular limitation.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) In the present invention, adding graphene oxide during the polymerization process of polystyrene can expand the distance between graphene oxide sheets and generate steric hindrance, so that the graphene oxide cannot agglomerate, and the graphene oxide is well dispersed in the polystyrene; soaking in alkaline aqueous solution and toluene can increase the specific surface area of ​​the graphene oxide, making it easy to peel off, which helps to improve the conductivity;

[0034] (2) The present invention introduces p-phenylenediamine into modified graphene oxide to obtain organic modified graphene oxide, which can not only improve the mechanical strength of graphene oxide, but also further improve the conductivity. At the same time, it can form cross-linking points with epoxy resin to increase the dispersibility of graphene in epoxy resin; nanosilver is further loaded on the organic modified graphene oxide and reduced to graphene, which can improve its conductivity;

[0035] (3) The present invention first disperses the modified graphene with good conductivity in the epoxy resin with good adhesion, and then polymerizes styrene in the epoxy resin mixture; first, the large number of conjugated double bonds in polystyrene can improve the antistatic performance of the coating; second, the polystyrene molecules and the epoxy resin molecules can form an interpenetrating network, which can not only improve the mechanical properties of the antistatic coating, but also the interpenetrating grid can effectively reduce the agglomeration of the modified graphene, thereby improving the antistatic performance of the coating;

[0036] (4) The present invention adds modified graphene to the epoxy resin, which not only improves the antistatic ability of the coating, but also improves the comprehensive properties of the antistatic coating, such as wear resistance and impact resistance. The preparation method of the present invention is simple, and the obtained antistatic coating has excellent conductivity and can be widely used in various antistatic fields. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is explained in detail below with reference to several representative embodiments of the present invention.

[0038] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0039] Example 1

[0040] (1) Preparation of modified graphene oxide

[0041] (1a) 2 g of graphene oxide, 60 g of styrene, 250 mL of anhydrous ethanol, 2.4 g of azobisisobutyronitrile, 4 g of sodium dodecyl sulfate, and 9.6 g of polyvinyl pyrrolidone were placed in a flask, nitrogen was introduced, ultrasonic dispersion was performed for 0.5 h, and the temperature was raised to 70 °C for reaction for 0.5 h;

[0042] (1b) 60 g of styrene and 1.1 g of ethylene glycol dimethacrylate were added to the reaction system of (1a) again, and the reaction was continued with stirring for 11 h. After the reaction was completed, the product was filtered, washed repeatedly with water and ethanol, and then immersed in a 6 mol / L potassium hydroxide aqueous solution. After washing with water until neutral, it was added to toluene and immersed, and centrifuged. This was repeated twice, and then washed with anhydrous ethanol and dried to obtain modified graphene oxide.

[0043] (2) Preparation of organically modified graphene oxide

[0044] 2 g of modified graphene oxide and 300 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, and sodium hydroxide solution was slowly added dropwise to adjust the pH to 9. After stirring for 0.5 h, the temperature was rapidly raised to 90° C., 16 g of p-phenylenediamine was added, and the temperature was maintained for 2 h. Organic modified graphene oxide was obtained by filtration and washing.

[0045] (3) Preparation of modified graphene

[0046] 2 g of organically modified graphene oxide and 500 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, 12 g of polyvinyl pyrrolidone was added, and ultrasonic treatment was performed for 0.5 h. 2 g of 0.002 mol / L silver nitrate aqueous solution was slowly added dropwise, and stirred and mixed at 30° C. for 0.5 h. Then 30 mL of ammonia water and 8 mL of hydrazine hydrate were added, and stirred and refluxed for 1 h. The modified graphene was obtained by centrifugation, washing, and drying.

[0047] (4) Preparation of epoxy resin containing modified graphene

[0048] 2 g of modified graphene, 40 g of epoxy resin E-51, and 500 mL of ethyl acetate were mixed and stirred for 1 h, and then 65 g of styrene and 1 g of azobisisobutyronitrile were added and heated in an oil bath at 70 ° C for 24 h, and then washed and dried to obtain epoxy resin with modified graphene added;

[0049] (5) Preparation of antistatic coating

[0050] (5a) Weigh 2 parts by mass of diethylenetriamine and 10 parts by mass of toluene, stir them evenly, and obtain a diethylenetriamine solution;

[0051] (5b) Weigh 30 parts by mass of epoxy resin to which modified graphene is added and 40 parts by mass of toluene, stir them evenly, add the above diethylenetriamine solution, and stir them evenly again to obtain an antistatic coating.

[0052] Example 2

[0053] (1) Preparation of modified graphene oxide

[0054] (1a) 2 g of graphene oxide, 72 g of styrene, 250 mL of anhydrous ethanol, 2.2 g of azobisisobutyronitrile, 4 g of sodium dodecyl sulfate, and 17.6 g of polyvinyl pyrrolidone were placed in a flask, nitrogen was introduced, ultrasonic dispersion was performed for 0.5 h, and the temperature was raised to 75 °C for reaction for 1 h;

[0055] (1b) 58 g of styrene and 1 g of ethylene glycol dimethacrylate were added to the reaction system of (1a) again, and the reaction was continued with stirring for 12 h. After the reaction was completed, the product was filtered, washed repeatedly with water and ethanol, and then immersed in a 6 mol / L potassium hydroxide aqueous solution. After washing with water until neutral, it was added to toluene and immersed, and centrifuged. This was repeated 3 times, and then washed with anhydrous ethanol and dried to obtain modified graphene oxide.

[0056] (2) Preparation of organically modified graphene oxide

[0057] 2 g of modified graphene oxide and 300 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, sodium hydroxide solution was slowly added dropwise to adjust the pH to 10, stirred for 0.5 h, and then the temperature was rapidly raised to 100 ° C, 18 g of p-phenylenediamine was added, and the temperature was maintained for 4 h. Organic modified graphene oxide was obtained by filtration and washing;

[0058] (3) Preparation of modified graphene

[0059] 2 g of organically modified graphene oxide and 500 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, 22 g of polyvinyl pyrrolidone was added, and ultrasonic treatment was performed for 0.5 h. 1 g of 0.002 mol / L silver nitrate aqueous solution was slowly added dropwise, and stirred and mixed at 35 ° C for 0.5 h. Then, 60 mL of ammonia water and 12 mL of hydrazine hydrate were added, and stirred and refluxed for 1 h. The modified graphene was obtained by centrifugation, washing, and drying.

[0060] (4) Preparation of epoxy resin containing modified graphene

[0061] 2 g of modified graphene, 60 g of epoxy resin E-44, and 500 mL of ethyl acetate were mixed and stirred for 1 h, and then 70 g of styrene and 1 g of azobisisobutyronitrile were added and heated in an oil bath at 65° C. for 22 h, and then washed and dried to obtain epoxy resin with modified graphene added;

[0062] (5) Preparation of antistatic coating

[0063] (5a) Weigh 3 parts by mass of 3-diethylaminopropylamine and 20 parts by mass of xylene, stir them evenly, and obtain a 3-diethylaminopropylamine solution;

[0064] (5b) Weigh 30 parts by mass of epoxy resin to which modified graphene is added and 50 parts by mass of xylene, stir them evenly, add the above 3-diethylaminopropylamine solution, stir them evenly again, and obtain an antistatic coating.

[0065] Example 3

[0066] (1) Preparation of modified graphene oxide

[0067] (1a) 2 g of graphene oxide, 94 g of styrene, 300 mL of anhydrous ethanol, 2.8 g of azobisisobutyronitrile, 6 g of sodium dodecyl sulfate, and 16.8 g of polyvinyl pyrrolidone were placed in a flask, nitrogen was introduced, ultrasonic dispersion was performed for 0.5 h, and the temperature was raised to 70 °C for reaction for 2 h;

[0068] (1b) 66 g of styrene and 1.1 g of ethylene glycol dimethacrylate were added to the reaction system of (1a) again, and the reaction was continued with stirring for 10 h. After the reaction was completed, the product was filtered, washed repeatedly with water and ethanol, and then immersed in a 6 mol / L potassium hydroxide aqueous solution. After washing with water until neutral, it was added to toluene and immersed, and centrifuged. This was repeated twice, and then washed with anhydrous ethanol and dried to obtain modified graphene oxide.

[0069] (2) Preparation of organically modified graphene oxide

[0070] 2 g of modified graphene oxide and 300 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, sodium hydroxide solution was slowly added dropwise to adjust the pH to 10, stirred for 0.5 h, and then the temperature was rapidly raised to 95 ° C, 20 g of p-phenylenediamine was added, and the temperature was maintained for 4 h. Organic modified graphene oxide was obtained by filtration and washing;

[0071] (3) Preparation of modified graphene

[0072] 2 g of organically modified graphene oxide and 500 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, 20 g of polyvinyl pyrrolidone was added, and ultrasonic treatment was performed for 0.5 h. 2 g of 0.002 mol / L silver nitrate aqueous solution was slowly added dropwise, and stirred and mixed at 40° C. for 0.5 h. Then, 50 mL of ammonia water and 4 mL of hydrazine hydrate were added, and the mixture was stirred and refluxed for 2 h. The modified graphene was obtained by centrifugation, washing, and drying.

[0073] (4) Preparation of epoxy resin containing modified graphene

[0074] 2 g of modified graphene, 50 g of epoxy resin E-51, and 500 mL of ethyl acetate were mixed and stirred for 1 h, and then 34 g of styrene and 0.5 g of azobisisobutyronitrile were added and heated in an oil bath at 75°C for 20 h, and then washed and dried to obtain epoxy resin with modified graphene added;

[0075] (5) Preparation of antistatic coating

[0076] (5a) Weigh 2 parts by mass of 3-diethylaminopropylamine and 20 parts by mass of xylene, stir them evenly, and obtain a 3-diethylaminopropylamine solution;

[0077] (5b) Weigh 50 parts by mass of epoxy resin to which modified graphene is added and 60 parts by mass of xylene, stir them evenly, add the above 3-diethylaminopropylamine solution, stir them evenly again, and obtain an antistatic coating.

[0078] Example 4

[0079] (1) Preparation of modified graphene oxide

[0080] (1a) 2 g of graphene oxide, 84 g of styrene, 250 mL of anhydrous ethanol, 2.4 g of azobisisobutyronitrile, 4 g of sodium dodecyl sulfate, and 4.8 g of polyvinyl pyrrolidone were placed in a flask, nitrogen was introduced, ultrasonic dispersion was performed for 0.5 h, and the temperature was raised to 70 °C for reaction for 1.5 h;

[0081] (1b) 56 g of styrene and 1 g of ethylene glycol dimethacrylate were added to the reaction system of (1a) again, and the reaction was continued with stirring for 14 h. After the reaction was completed, the product was filtered, washed repeatedly with water and ethanol, and then immersed in a 6 mol / L potassium hydroxide aqueous solution. After washing with water until neutral, it was added to toluene and immersed, and centrifuged. This was repeated twice, and then washed with anhydrous ethanol and dried to obtain modified graphene oxide.

[0082] (2) Preparation of organically modified graphene oxide

[0083] 2 g of modified graphene oxide and 300 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, sodium hydroxide solution was slowly added dropwise to adjust the pH to 9, stirred for 0.5 h, and then the temperature was rapidly raised to 85 ° C, 24 g of p-phenylenediamine was added, and the temperature was maintained for 3 h. Organic modified graphene oxide was obtained by filtration and washing;

[0084] (3) Preparation of modified graphene

[0085] 2 g of organically modified graphene oxide and 500 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, 16 g of polyvinyl pyrrolidone was added, and ultrasonic treatment was performed for 0.5 h. 4 g of 0.002 mol / L silver nitrate aqueous solution was slowly added dropwise, and stirred and mixed at 50° C. for 0.5 h. Then, 70 mL of ammonia water and 12 mL of hydrazine hydrate were added, and stirred and refluxed for 2 h. The modified graphene was obtained by centrifugation, washing, and drying.

[0086] (4) Preparation of epoxy resin containing modified graphene

[0087] 2 g of modified graphene, 60 g of epoxy resin E-12, and 500 mL of ethyl acetate were mixed and stirred for 1 h, and then 30 g of styrene and 0.4 g of azobisisobutyronitrile were added and heated in an oil bath at 75°C for 26 h, and then washed and dried to obtain epoxy resin with modified graphene added;

[0088] (5) Preparation of antistatic coating

[0089] (5a) Weigh 1 part by mass of diethylenetriamine and 10 parts by mass of toluene, stir them evenly, and obtain a diethylenetriamine solution;

[0090] (5b) Weigh 40 parts by mass of epoxy resin to which modified graphene is added and 50 parts by mass of toluene, stir them evenly, add the above diethylenetriamine solution, and stir them evenly again to obtain an antistatic coating.

[0091] Example 5

[0092] (1) Preparation of modified graphene oxide

[0093] (1a) 2 g of graphene oxide, 75 g of styrene, 250 mL of anhydrous ethanol, 2.8 g of azobisisobutyronitrile, 5 g of sodium dodecyl sulfate, and 11.2 g of polyvinyl pyrrolidone were placed in a flask, nitrogen was introduced, ultrasonic dispersion was performed for 0.5 h, and the temperature was raised to 80 °C for reaction for 2 h;

[0094] (1b) 75 g of styrene and 1.3 g of ethylene glycol dimethacrylate were added to the reaction system of (1a) again, and the reaction was continued with stirring for 12 h. After the reaction was completed, the product was filtered, washed repeatedly with water and ethanol, and then immersed in a 6 mol / L potassium hydroxide aqueous solution. After washing with water until neutral, it was added to toluene and immersed, and centrifuged. This was repeated 3 times, and then washed with anhydrous ethanol and dried to obtain modified graphene oxide.

[0095] (2) Preparation of organically modified graphene oxide

[0096] 2 g of modified graphene oxide and 300 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, sodium hydroxide solution was slowly added dropwise to adjust the pH to 10, stirred for 0.5 h, and then the temperature was rapidly raised to 100 ° C, 20 g of p-phenylenediamine was added, and the temperature was maintained for 3 h. Organic modified graphene oxide was obtained by filtration and washing;

[0097] (3) Preparation of modified graphene

[0098] 2 g of organically modified graphene oxide and 500 mL of deionized water were placed in a three-necked flask, ultrasonically dispersed for 0.5 h, 14 g of polyvinyl pyrrolidone was added, and ultrasonic treatment was performed for 0.5 h. 4 g of 0.002 mol / L silver nitrate aqueous solution was slowly added dropwise, and stirred and mixed at 45° C. for 0.5 h. Then, 40 mL of ammonia water and 4 mL of hydrazine hydrate were added, and stirred and refluxed for 2 h. The modified graphene was obtained by centrifugation, washing, and drying.

[0099] (4) Preparation of epoxy resin containing modified graphene

[0100] 2 g of modified graphene, 50 g of epoxy resin E-12, and 500 mL of ethyl acetate were mixed and stirred for 1 h, and then 37.5 g of styrene and 0.5 g of azobisisobutyronitrile were added and heated in an oil bath at 65 °C for 24 h, and then washed and dried to obtain epoxy resin with modified graphene added;

[0101] (5) Preparation of antistatic coating

[0102] (5a) Weigh 3 parts by mass of triethylenetetramine and 15 parts by mass of toluene, stir them evenly, and obtain a triethylenetetramine solution;

[0103] (5b) Weigh 45 parts by mass of epoxy resin to which modified graphene is added and 50 parts by mass of toluene, stir them evenly, add the above triethylenetetramine solution, and stir them evenly again to obtain an antistatic coating.

[0104] Comparative Example 1

[0105] An antistatic coating, whose formula and preparation method are basically the same as those of Example 1. The difference is that the modified graphene is prepared by using graphene oxide as a raw material, sequentially modified with p-phenylenediamine and nanosilver, and finally reduced with a reducing agent.

[0106] Comparative Example 2

[0107] An antistatic coating, whose formula and preparation method are basically the same as those of Example 1. The difference is that the modified graphene uses graphene oxide as a raw material, the modified graphene oxide is prepared by a template method, and then p-phenylenediamine is used for modification, and finally the modified graphene oxide is reduced by a reducing agent.

[0108] Comparative Example 3

[0109] An antistatic coating, whose formula and preparation method are basically the same as those of Example 1. The difference is that the modified graphene uses graphene oxide as a raw material, the modified graphene oxide is prepared by a template method, and then modified by nanosilver, and finally reduced by a reducing agent.

[0110] Comparative Example 4

[0111] An antistatic coating, whose formula and preparation method are substantially the same as those of Example 1. The difference is that the coating is directly prepared using unmodified graphene as raw material.

[0112] The antistatic coatings obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were uniformly coated on the surface of the material, cured under appropriate conditions, and tested for various properties. The test results are as follows:

[0113] Table 1 Test results

[0114]

[0115] As can be seen from Table 1, graphene modified with polystyrene can improve the dispersibility of graphene, reduce agglomeration, and increase conductivity. Paraphenylenediamine and nanosilver further improve the mechanical properties of the antistatic coating. The antistatic coating prepared by the present invention has good antistatic performance and comprehensive performance.

[0116] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or equivalent replacement that can be done by other technicians in this field without expending creative labor falls within the protection scope of the present invention.

Claims

1. An antistatic coating, characterized in that: The coating comprises epoxy resin added with modified graphene; the epoxy resin added with modified graphene is prepared by uniformly mixing modified graphene, epoxy resin and ethyl acetate, and then adding styrene and an initiator to heat and react; Wherein, in terms of mass ratio, modified graphene: epoxy resin = 1:20-30, styrene: modified graphene: initiator = 65-75:2-6:1; reaction temperature is 65-75°C, reaction time is 20-26h; The initiator is azobisisobutyronitrile; The modified graphene preparation method is as follows: (1) Preparation of modified graphene oxide Styrene, graphene oxide, anhydrous ethanol, an initiator, an emulsifier, a stabilizer and ethylene glycol dimethacrylate are ultrasonically dispersed under anaerobic conditions and heated to react, wherein: (1a) adding part of styrene to a dispersion of graphene oxide, anhydrous ethanol, initiator, emulsifier and stabilizer for a reaction time of 0.5-2 h; (1b) adding ethylene glycol dimethacrylate and the remaining styrene again and continuing the reaction for 10-14 hours; Wherein, the part of styrene accounts for 50%-60% of the total mass of styrene; After the reaction is completed, the product is filtered and washed, then immersed in an alkaline aqueous solution, washed with water, immersed in toluene, centrifuged, and repeated 2-3 times, washed with anhydrous ethanol, and dried to obtain modified graphene oxide; (2) Preparation of organically modified graphene oxide Dispersing the modified graphene oxide in water, adjusting the pH, stirring and heating, adding p-phenylenediamine to react, filtering, and washing to obtain organic modified graphene oxide; (3) Preparation of modified graphene Dispersing organic modified graphene oxide in water, adding polypropylene pyrrolidone and mixing evenly, slowly dropping silver nitrate aqueous solution to react, then adding a reducing agent to perform a reflux reaction, and obtaining modified graphene by centrifugation, washing, and drying; In step (1), the initiator is azobisisobutyronitrile, the emulsifier is sodium dodecyl sulfate, the stabilizer is polyvinyl pyrrolidone, and the alkaline aqueous solution is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution; In step (3), the reducing agent is a mixed solution of ammonia water and hydrazine hydrate; The preparation method of the antistatic coating comprises the following steps: S1: Weigh 1-3 parts by mass of epoxy resin curing agent and 10-20 parts by mass of solvent, stir evenly to obtain a curing agent solution; S2: Weigh 30-50 parts by mass of epoxy resin added with modified graphene and 40-60 parts by mass of solvent, stir them evenly, then add the curing agent solution, stir them evenly again, and obtain an antistatic coating.

2. The antistatic coating according to claim 1, characterized in that: In the step (1), by mass ratio, styrene: graphene oxide = 60-80:1, styrene: stabilizer: initiator = 50-60:2-8:1, and the remaining styrene: ethylene glycol dimethacrylate = 55-60:1; the reaction temperature is 70-80°C.

3. The antistatic coating according to claim 1, characterized in that: In the step (2), the mass ratio of modified graphene oxide to p-phenylenediamine is 1:8-12; The pH value is 9-10; the reaction temperature is 85-100°C, and the reaction time is 2-4h.

4. The antistatic coating according to claim 1, characterized in that: In the step (3), the mass ratio of organically modified graphene oxide: silver nitrate: polyvinyl pyrrolidone is 1:0.5-2:5-12; the mass ratio of organically modified graphene oxide: ammonia water: hydrazine hydrate is 1 g: 15-35 mL: 2-6 mL; and the reaction temperature is 30-50°C.

5. The method for preparing the antistatic coating according to any one of claims 1 to 4, characterized in that: The steps include: S1: Weigh 1-3 parts by mass of epoxy resin curing agent and 10-20 parts by mass of solvent, stir evenly, and obtain a curing agent solution; S2: Weigh 30-50 parts by mass of epoxy resin added with modified graphene and 40-60 parts by mass of solvent, stir them evenly, then add the curing agent solution, stir them evenly again, and obtain an antistatic coating.

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