High-dispersion graphene conductive oily paint and preparation method thereof

Abstract

The invention provides a high-dispersion graphene conductive oily coating and a preparation method thereof, and belongs to the technical field of coatings. Graphene powder prepared through mechanical stripping and heat treatment serves as a conductive component and is added into a mixed solvent system, a dispersing agent, a thickening agent and the like serve as auxiliaries, and the graphene conductive coating is prepared with oily fluorocarbon resin serving as a film forming component through physical mixing methods such as mechanical stirring, grinding and ball milling. Due to the interaction of the dispersing agent and the thickening agent, graphene powder particles are suspended and dispersed in the oily fluorocarbon resin, an oily fluorocarbon resin suspension containing the graphene powder is formed, and high dispersion of the graphene powder in the fluorocarbon resin is achieved. Compared with the prior art, the graphene conductive coating prepared by the invention has higher graphene content and excellent conductivity and acid and alkali resistance.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a highly dispersed graphene conductive oily coating and a preparation method thereof. Background Art

[0002] Conductive coating refers to a type of coating that adheres to various substrates to enable them to conduct current and has been widely used in various fields.

[0003] The conductive coatings prepared by researchers at present mainly have the disadvantages of poor conductivity, poor dispersibility, and poor corrosion resistance. Most of the research focuses on external conductive coatings, that is, adding corresponding conductive components such as graphite, carbon black, metal powder, metal oxides, etc. when preparing the coating. In recent years, graphene has been often used as an additive for conductive coatings due to its large specific surface area, excellent mechanical properties, and extremely high thermal conductivity (5300W). However, due to the characteristics of graphene itself, it is easy to agglomerate when added, and the amount of graphene added is greatly reduced, thus affecting the final performance of the product. Most researchers choose water-based coating systems to try to solve this problem, but the corrosion resistance of water-based coatings, especially poor water resistance, limits its scope of application.

[0004] Oily paints are widely used in our daily lives due to their excellent corrosion resistance and water resistance. Current oily graphene paints all have the problems of low graphene content and poor conductivity. How to increase the content of graphene as a conductive component in the paint and prepare a paint with both conductivity and corrosion resistance is a problem that needs to be solved at present. Summary of the invention

[0005] The object of the present invention is to provide a highly dispersed graphene conductive oily coating and a preparation method thereof, so as to solve the technical problems of poor conductivity, low corrosion resistance and low graphene content of the conductive coating in the prior art.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The invention provides a highly dispersed graphene conductive oily coating, which is composed of the following components in parts by mass: 40 to 90 parts of oily fluorocarbon resin, 10 to 20 parts of mixed solvent, 1 to 5 parts of dispersant, 10 to 60 parts of graphene powder, 1 to 5 parts of inorganic metal oxide powder, and 0.1 to 0.5 parts of thickener.

[0008] Further, the oily fluorocarbon resin includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, fluoroethylene-vinyl ether copolymer, perfluoroethylene propylene copolymer and soluble polytetrafluoroethylene;

[0009] The dispersant includes one or more of propylene glycol diglycidyl ether, 17-hydroxyoleic acid, decaglycerol palmitate, decaglycerol laurate and decaglycerol laurate;

[0010] The mixed solvent includes at least two of toluene, xylene, ethyl acetate and ethanol.

[0011] Furthermore, the preparation method of the graphene powder is: preparing graphene slurry by mechanical exfoliation, and obtaining the graphene slurry after heat treatment and crushing;

[0012] The flake diameter of the graphene powder is 0.1-10 nm.

[0013] Furthermore, the heat treatment temperature is 380-400° C., and the heat treatment time is 2-4 hours.

[0014] Further, the inorganic metal oxide powder includes one or more of aluminum oxide, magnesium oxide and copper oxide;

[0015] The particle size of the inorganic metal oxide powder is 50 to 100 nm.

[0016] Furthermore, the thickener includes one or more of polystyrene, polyvinyl acetate, polyamide wax and polyethylene oxide.

[0017] The present invention provides a method for preparing the above-mentioned highly dispersed graphene conductive oily coating, comprising the following steps:

[0018] Step 1) mixing a dispersant, a thickener and a mixed solvent, then adding graphene powder and grinding and stirring in sequence to obtain an oily graphene slurry;

[0019] Step 2) mixing the oily graphene slurry with the oily fluorocarbon resin to obtain a highly dispersed graphene conductive oily coating.

[0020] Furthermore, in step 1), the grinding speed is 100 to 300 rpm, and the grinding time is 10 to 30 min;

[0021] The stirring speed is 500-2000 rpm, and the stirring time is 10-20 min.

[0022] Furthermore, in step 2), the mixing is carried out under stirring, the stirring speed is 1500 to 3000 rpm, and the stirring time is 10 to 20 minutes.

[0023] Beneficial effects of the present invention:

[0024] The present invention uses graphene powder as a conductive component, an oily fluorocarbon resin as a film-forming structure, and adds an oily dispersant and a thickener. Through suspension and dispersion, high dispersion of graphene powder in oily paint is achieved without stratification or sedimentation. The viscosity of the paint can be regulated by adding a mixed solvent to meet different construction needs, effectively improving the conductivity and corrosion resistance of the oily graphene paint, and can be applied to mobile phones, tablet computers, electronic computers and other devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a preparation route map of the graphene conductive oily coating;

[0026] Figure 2 This is a photo of the coating after the graphene conductive oily coating prepared in Example 1 is peeled off after drying. DETAILED DESCRIPTION

[0027] The invention provides a highly dispersed graphene conductive oily coating, which is composed of the following components in parts by mass: 40 to 90 parts of oily fluorocarbon resin, 10 to 20 parts of mixed solvent, 1 to 5 parts of dispersant, 10 to 60 parts of graphene powder, 1 to 5 parts of inorganic metal oxide powder, and 0.1 to 0.5 parts of thickener.

[0028] In the present invention, the content of the oily fluorocarbon resin is preferably 60 to 80 parts by mass, and more preferably 70 parts;

[0029] In the present invention, the content of the mixed solvent is preferably 12 to 18 parts by mass, and more preferably 15 parts;

[0030] In the present invention, the content of the dispersant is preferably 2 to 4 parts by mass, more preferably 3 parts;

[0031] In the present invention, the content of the graphene powder is preferably 20 to 50 parts by mass, more preferably 30 to 40 parts, and more preferably 35 parts;

[0032] In the present invention, the content of the inorganic metal oxide powder is preferably 2 to 4 parts by mass, more preferably 3 parts;

[0033] In the present invention, the content of the thickener is preferably 0.2 to 0.4 parts by mass, and more preferably 0.3 parts by mass.

[0034] In the present invention, the oily fluorocarbon resin includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, fluoroethylene-vinyl ether copolymer, perfluoroethylene-propylene copolymer and soluble polytetrafluoroethylene, preferably one or more of polyvinylidene fluoride, polytetrafluoroethylene and fluoroethylene-vinyl ether copolymer, and more preferably polyvinylidene fluoride;

[0035] The dispersant includes one or more of propylene glycol diglycidyl ether, 17-hydroxyoleic acid, decaglycerol palmitate, decaglycerol laurate and decaglycerol laurate, preferably one or more of propylene glycol diglycidyl ether, 17-hydroxyoleic acid, decaglycerol palmitate and decaglycerol laurate, further preferably propylene glycol diglycidyl ether and / or 17-hydroxyoleic acid, more preferably propylene glycol diglycidyl ether;

[0036] The mixed solvent includes at least two of toluene, xylene, ethyl acetate and ethanol, preferably at least two of toluene, xylene and ethyl acetate, and more preferably toluene and xylene.

[0037] In the present invention, when toluene and xylene are used as a mixed solvent, the volume ratio of the toluene / xylene mixed solvent is preferably 2-5:5-8, and more preferably 4:6.

[0038] In the present invention, the preparation method of the graphene powder is: preparing graphene slurry by mechanical exfoliation, and obtaining the graphene slurry after heat treatment and crushing;

[0039] The flake diameter of the graphene powder is preferably 0.1 to 10 nm.

[0040] In the present invention, the heat treatment temperature is 380-400° C., preferably 390° C., and the heat treatment time is 2-4 hours, preferably 3 hours.

[0041] In the present invention, the inorganic metal oxide powder includes one or more of aluminum oxide, magnesium oxide and copper oxide, preferably aluminum oxide and / or magnesium oxide, and more preferably aluminum oxide;

[0042] The particle size of the inorganic metal oxide powder is 50 to 100 nm.

[0043] In the present invention, the thickener includes one or more of polystyrene, polyvinyl acetate, polyamide wax and polyethylene oxide, preferably one or more of polystyrene, polyvinyl acetate and polyamide wax, and more preferably polystyrene and / or polyamide wax.

[0044] In the present invention, when the thickener is a combination of polystyrene and polyamide wax, the mass ratio of polystyrene to polyamide wax is preferably 6 to 8:2 to 4, and more preferably 7:3.

[0045] The present invention provides a method for preparing the above-mentioned highly dispersed graphene conductive oily coating, comprising the following steps:

[0046] Step 1), mixing a dispersant, a thickener and a mixed solvent, then adding graphene powder and grinding and stirring in sequence to obtain an oily graphene slurry;

[0047] Step 2), mixing the oily graphene slurry with the oily fluorocarbon resin to obtain a highly dispersed graphene conductive oily coating.

[0048] In the present invention, in step 1), the grinding speed is 100 to 300 rpm, preferably 200 rpm, and the grinding time is 10 to 30 min, preferably 20 min;

[0049] The stirring speed is 500-2000 rpm, preferably 800-1500 rpm, more preferably 1000-1300 rpm, and more preferably 1200 rpm. The stirring time is 10-20 min, and preferably 15 min.

[0050] In the present invention, in step 2), the mixing is performed under stirring, the stirring speed is 1500-3000 rpm, preferably 1800-2500 rpm, more preferably 2000-2300 rpm, more preferably 2200 rpm, and the stirring time is 10-20 min, preferably 15 min.

[0051] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0052] Example 1

[0053] The graphene slurry prepared by the mechanical exfoliation method was heat treated at 380°C for 4 hours and then crushed to obtain graphene powder.

[0054] 0.4 parts of polystyrene, 0.1 parts of polyamide wax, 2 parts of propylene glycol diglycidyl ether, 10 parts of toluene and 10 parts of xylene were mixed, stirred evenly, and then 20 parts of graphene powder were added, and stirred at a speed of 1200 rpm for 15 minutes to obtain an oily graphene slurry;

[0055] The obtained oily graphene slurry, 3 parts of aluminum oxide, 40 parts of polyvinylidene fluoride and 40 parts of polytetrafluoroethylene were mixed, first ground at a rotation speed of 200 rpm for 20 minutes, then stirred at a rotation speed of 2200 rpm for 15 minutes, and filtered through a filter to obtain a graphene conductive oily coating.

[0056] The obtained highly dispersed oily graphene conductive coating has a surface resistance of 263Ω after drying and curing, and is resistant to acid and alkali corrosion for 2160h.

[0057] Example 2

[0058] The graphene slurry prepared by the mechanical exfoliation method was heat treated at 390°C for 4 hours and then crushed to obtain graphene powder.

[0059] 0.3 parts of polystyrene, 0.2 parts of polyvinyl acetate, 2 parts of propylene glycol diglycidyl ether, 5 parts of toluene and 15 parts of xylene were mixed, stirred evenly, and then 30 parts of graphene powder were added, and stirred at a speed of 1200 rpm for 15 minutes to obtain an oily graphene slurry;

[0060] The obtained oily graphene slurry, 2 parts of aluminum oxide, 3 parts of magnesium oxide, 30 parts of polyvinylidene fluoride and 40 parts of polytetrafluoroethylene were mixed, first ground at a rotation speed of 200 rpm for 20 minutes, then stirred at a rotation speed of 2200 rpm for 15 minutes, and filtered through a filter to obtain a graphene conductive oily coating.

[0061] The obtained highly dispersed oily graphene conductive coating has a surface resistance of 194Ω after drying and curing, and is resistant to acid and alkali corrosion for 1752h.

[0062] Example 3

[0063] The graphene slurry prepared by mechanical exfoliation was heat treated at 400°C for 2 h and then crushed to obtain graphene powder.

[0064] 0.2 parts of polystyrene, 0.1 parts of polyamide wax, 0.1 parts of polyethylene oxide, 2 parts of 17-hydroxyoleic acid, 8 parts of toluene and 12 parts of xylene were mixed, stirred evenly, 40 parts of graphene powder were added, stirred at a speed of 2000 rpm for 15 minutes, and filtered to obtain an oily graphene slurry;

[0065] The obtained oily graphene slurry, 2 parts of copper oxide, 20 parts of polyvinylidene fluoride and 40 parts of polytetrafluoroethylene were mixed, first ground at a rotation speed of 200 rpm for 20 minutes, then stirred at a rotation speed of 1500 rpm for 15 minutes, and filtered through a filter to obtain a graphene conductive oily coating.

[0066] The obtained highly dispersed oily graphene conductive coating has a surface resistance of 167Ω after drying and curing, and is resistant to acid and alkali corrosion for 2208h.

[0067] Example 4

[0068] The graphene slurry prepared by the mechanical exfoliation method was heat treated at 380°C for 4 hours and then crushed to obtain graphene powder.

[0069] 0.3 parts of polystyrene, 0.1 parts of polyamide wax, 0.1 parts of polyethylene oxide, 2 parts of propylene glycol diglycidyl ether, 5 parts of toluene and 15 parts of xylene were mixed, and 50 parts of graphene powder were added after stirring evenly, and stirred at a speed of 500 rpm for 15 minutes, and the oily graphene slurry was obtained after filtering;

[0070] The obtained oily graphene slurry, 1 part of aluminum oxide, 2 parts of magnesium oxide, 1 part of copper oxide, 20 parts of polyvinylidene fluoride and 30 parts of soluble polytetrafluoroethylene were mixed, first ground at a rotation speed of 200 rpm for 20 minutes, then stirred at a rotation speed of 3000 rpm for 15 minutes, and filtered through a filter to obtain a graphene conductive oily coating.

[0071] The obtained highly dispersed oily graphene conductive coating has a surface resistance of 88Ω after drying and curing, and is resistant to acid and alkali corrosion for 2112h.

[0072] The acid and alkali resistance test method is: apply the coating on a tinplate sheet with a specification of 50mm×120mm×(0.2~0.3)mm, and immerse the iron sheet completely in a 1wt.% sulfuric acid aqueous solution or a 1wt.% sodium hydroxide aqueous solution, and record daily whether the paint film on the iron sheet is peeling, bubbling, or falling off.

[0073] It can be seen from the above embodiments that the present invention provides a highly dispersed graphene conductive oily coating and a preparation method thereof. The graphene conductive oily coating prepared by the present invention has good corrosion resistance and excellent conductivity, which solves the technical problems of poor conductivity, poor corrosion resistance and low graphene content of conductive coatings in the prior art.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A highly dispersed graphene conductive oily coating, characterized in that: The invention is composed of the following components in parts by mass: 40 to 90 parts of oily fluorocarbon resin, 10 to 20 parts of mixed solvent, 1 to 5 parts of dispersant, 10 to 60 parts of graphene powder, 1 to 5 parts of inorganic metal oxide powder and 0.1 to 0.5 parts of thickener.

2. A highly dispersed graphene conductive oily paint according to claim 1, characterized in that: The oily fluorocarbon resin includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, fluoroethylene-vinyl ether copolymer, perfluoroethylene-propylene copolymer and soluble polytetrafluoroethylene; The dispersant includes one or more of propylene glycol diglycidyl ether, 17-hydroxyoleic acid, decaglycerol palmitate, decaglycerol laurate and decaglycerol laurate; The mixed solvent includes at least two of toluene, xylene, ethyl acetate and ethanol.

3. A highly dispersed graphene conductive oily paint according to claim 1 or 2, characterized in that: The preparation method of the graphene powder comprises: preparing graphene slurry by mechanical exfoliation, and obtaining the graphene slurry by heat treatment and crushing; The flake diameter of the graphene powder is 0.1-10 nm.

4. A highly dispersed graphene conductive oily paint according to claim 3, characterized in that: The temperature of the heat treatment is 380-400° C., and the time of the heat treatment is 2-4 hours.

5. A highly dispersed graphene conductive oily paint according to claim 1, 2 or 4, characterized in that: The inorganic metal oxide powder includes one or more of aluminum oxide, magnesium oxide and copper oxide; The particle size of the inorganic metal oxide powder is 50 to 100 nm.

6. A highly dispersed graphene conductive oily paint according to claim 5, characterized in that: The thickener includes one or more of polystyrene, polyvinyl acetate, polyamide wax and polyethylene oxide.

7. The method for preparing the highly dispersed graphene conductive oily coating according to claim 1, characterized in that: The following steps are involved: Step 1) mixing a dispersant, a thickener and a mixed solvent, then adding metal oxide powder and graphene powder, grinding and stirring in sequence to obtain an oily graphene slurry; Step 2) mixing the oily graphene slurry with the oily fluorocarbon resin to obtain a highly dispersed graphene conductive oily coating.

8. The method for preparing a highly dispersed graphene conductive oily coating according to claim 7, characterized in that: In step 1), the grinding speed is 100 to 300 rpm, and the grinding time is 10 to 30 min; The stirring speed is 500-2000 rpm, and the stirring time is 10-20 min.

9. A method for preparing a highly dispersed graphene conductive oily coating according to claim 7 or 8, characterized in that: In step 2), the mixing is carried out under stirring, the stirring speed is 1500-3000 rpm, and the stirring time is 10-20 min.

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