CN103131232A - High-performance aqueous graphene paint and preparation method thereof - Google Patents

Abstract

The invention discloses a high-performance water-based graphene conductive coating and a preparation method thereof. After oxidizing natural graphite in an oxidant, a two-step chemical reduction method is used to obtain an aqueous solution of graphene modified by organic molecules, and polyester is added through a solution blending method. , neutralizer, leveling agent, defoamer, crosslinking agent, catalyst to prepare water-based conductive graphene coating. The resulting coating is sprayed, inkjet printed, and printed to prepare a conductive coating with high electrical conductivity and mechanical properties, which can be used in fields such as electromagnetic shielding, antistatic, anticorrosion, heat dissipation, wear resistance, and electronic circuits, and has a wide range of applications value.

Description

High-performance water-based graphene conductive coating and preparation method thereof

technical field

The invention relates to a water-based graphene conductive coating and a manufacturing method thereof.

Background technique

Conductive coatings are a new type of functional coatings that are applied on substrates such as non-conductive polymer materials to enable them to conduct current and eliminate accumulated static charges. The conductivity after coating is generally greater than 10S/m, and has been widely used. To various fields, such as the conductive connection of integrated circuit components, the connection of non-solderable places, plastic brackets for shielding high-frequency magnetic fields, invisible materials for aircraft, conductive films, etc. In addition, conductive coatings also have great use value in the electronic market, such as PCB design and repair, car defogging heating wire disconnection repair, keyboard printed circuit repair, etc.

At present, conductive coatings can be divided into structural conductive coatings and additive conductive coatings according to the conductive mechanism and composition. Structural conductive coatings are mainly formed by polymers with conductive coatings; additive conductive coatings mainly add conductive particles with conductive capabilities to insulating polymers, and the conductive particles are in contact with each other after the polymers are cured. , to form a conductive path, so that the conductive coating has the ability to conduct electricity. Additive conductive coatings have the advantages of simple equipment, convenient operation, low cost, and can be applied to surfaces with various complex shapes. The market application range is wider.

Recently, additive-type conductive coatings have made great and rapid progress because they can be widely used in electromagnetic wave shielding, antistatic, metal anti-corrosion, electronic circuits, electrode reflective materials, etc., and a variety of strong conductive conductive coatings have been developed successively. The fillers mainly include metal series (silver powder, copper powder, nickel powder, etc.), metal/glass composite and carbon series (graphite, carbon black), etc. However, in these conductive coatings, it is difficult to improve the mechanical strength and electrical conductivity of the prepared coating at the same time, and the density of the coating is relatively high. These problems greatly limit the scope of its application. The recently developed graphene conductive material, because of its low density (0.77mg/m ² ) and high mechanical strength (Young's modulus is 1060Gpa, the strength is the highest among the tested materials, reaching 130Gpa, which is more than 100 times that of steel. times). In addition, its carrier mobility reaches 200,000cm ² V ^-1 s ^-1 , more than 10 times higher than that of commercial silicon chips, and has a higher conductivity than silver (10 ⁶ Scm ^-1 ). Therefore, using graphene as a conductive filler is expected to solve the above-mentioned problems of conductive coatings, and greatly expand the application range and field of conductive coatings.

Contents of the invention

The invention provides a high-performance water-based graphene conductive paint and a preparation method thereof, aiming at the problems of high density of the existing conductive paint and difficulty in simultaneously improving the conductive performance and the mechanical performance.

The present invention is realized by adopting the following technical solutions:

A high-performance water-based graphene conductive coating, which is composed of graphene with high conductivity (conductivity>10 ³ cm/S) and high water stability (no precipitation in aqueous solution for more than half a year) as conductive filler.

The present invention simultaneously provides a kind of preparation method of high-performance water-based graphene conductive paint, and the steps are as follows:

(1) Add 0.5~5.0g of graphite to 40ml~60ml of concentrated sulfuric acid in an ice bath, and stir vigorously for 30 minutes; further add 12~30g _KMnO4 into the above mixture, and stir vigorously for 30 minutes; Transfer the solution to a water bath at 30°C, slowly add 18-40g NaNO ₃ , and stir for 60 minutes; while stirring, add 100-140ml deionized water continuously to the above mixture, and then transfer it to an oil bath at a temperature of 90°C , stir for 30 minutes; then add 12-20ml H ₂ O ₂ dropwise, and continue the reaction for 40-80 minutes until the solution turns from dark brown to bright yellow;

(2) Under stirring conditions, add a certain amount of dispersing reagent to the above bright yellow graphene oxide solution, add dropwise 15-45ml of hydrazine hydrate solution after dissolving, and react at 40°C-80°C for 1 hour; Add 15-45ml of reducing reagent dropwise into the solution, and continue the reaction for 20-60 minutes to obtain a stable graphene aqueous solution;

(3) Add a certain amount of water-based polyester, neutralizer, leveling agent, defoamer, cross-linking agent, and catalytic reagent to the above-mentioned stable graphene aqueous solution in sequence, and stir at a certain temperature for a certain period of time to obtain High-performance water-based graphene conductive coating.

In the preparation method of the water-based graphene conductive coating, in step (2), the dispersing agent is PVP, PVA, PEG or PEDOT:PSS; the aqueous solution concentration of the dispersing agent is 0.5-20wt%.

In the preparation method of the water-based graphene conductive coating, in step (2), the reducing agent is acetic acid or hydroiodic acid; the concentration of the acetic acid aqueous solution is 10-30wt%, and the concentration of the hydroiodic acid aqueous solution is 10-40wt%.

In the preparation method of the water-based graphene conductive coating, in step (3), the water-based polyester is, the neutralizing agent is ethanolamine, the leveling agent is monobutyl ether, and the defoamer is defoamer 901 or 902.

The preparation method of the water-based graphene conductive coating, the amount of the water-based polyester, neutralizer, leveling agent, and defoamer are respectively 5-20wt%, 0.1-2wt%, 0.15-0.5wt% of the coating composition , 0.02～0.1wt%.

In the preparation method of the water-based graphene conductive coating, the cross-linking agent is melamine formaldehyde or amino resin, and the addition amount is 5-25wt% of the water-based polyester.

In the preparation method of the water-based graphene conductive coating, the catalytic reagent is ethylenediamine, and the addition amount is 0-2.0wt% of the water-based polyester.

In the preparation method of the water-based graphene conductive paint, the stirring temperature of the paint is 5-30° C., and the stirring time is 10 min-3 hours.

The purposes of the water-based graphene conductive coating prepared by the method: the coating is used for spraying, inkjet printing and printing process to prepare the coating; the coating is used on the surface of polymer materials, metal materials and inorganic non-metal materials for electromagnetic shielding , Anti-static, anti-corrosion, heat dissipation, wear-resistant and electronic circuit fields.

The use of the water-based graphene conductive coating: the drying temperature of the coating is 50-100°C, and the drying time is 30S-10min.

The above-mentioned high-performance water-based graphene conductive coating can be prepared on the surface of polymer materials, metal materials, and inorganic non-metallic materials by spraying, inkjet printing, and printing processes. The drying temperature of the coating is 20-100 ° C, and the drying time is 30S～10min, the prepared graphene coating can be used in fields such as electromagnetic shielding, antistatic, anticorrosion, heat dissipation, wear resistance and electronic circuits.

Detailed ways

The present invention will be further described below in conjunction with specific examples.

Example 1

Under the condition of ice bath, add 3.0g of graphite into 60ml of concentrated sulfuric acid, stir vigorously for 30min, further add _12gKMnO4 into the above mixture, stir vigorously for 30min. Transfer the above mixed solution to a 30°C water bath, slowly add 18g NaNO ₃ , and stir for 60 minutes; while stirring, continuously add 140ml of deionized water to the above mixed solution, and then transfer it to an oil bath at a temperature of 90°C , stirred for 30 minutes; then added 18ml of H ₂ O ₂ dropwise, and continued to react for 60 minutes so that the solution changed from dark brown to bright yellow;

Under stirring conditions, add 1.5wt% graphene oxide dispersing agent PVP to the above graphene oxide solution, add dropwise 20ml of hydrazine hydrate solution after dissolving, react at 60°C for 1h, and further dissolve in the above solution 20ml of 20wt% acetic acid aqueous solution was added dropwise, and the reaction was continued for 30min to obtain a stable graphene aqueous solution. Add 11wt% water-based polyacrylate, 0.15wt% ethanolamine, 0.15wt% monobutyl ether, 0.07wt% defoamer 901, and 1.5wt% melamine formaldehyde for water-based polyester to the above stable aqueous solution. Stirring at a temperature of 20°C for 30 minutes, a high-performance water-based graphene conductive coating can be obtained. The drying temperature of the coating is 80° C., and the drying time is 10 minutes.

Example 2

Under the condition of ice bath, add 3.0g of graphite into 60ml of concentrated sulfuric acid, stir vigorously for 30min, further add _12gKMnO4 into the above mixture, stir vigorously for 30min. Transfer the above mixed solution to a 30°C water bath, slowly add 18g NaNO ₃ , and stir for 60 minutes; while stirring, continuously add 140ml of deionized water to the above mixed solution, and then transfer it to an oil bath at a temperature of 90°C , stirred for 30 minutes; then added 18ml of H ₂ O ₂ dropwise, and continued to react for 60 minutes so that the solution changed from dark brown to bright yellow;

Under stirring conditions, add 2.5wt% graphene oxide dispersing agent PVA to the above graphene oxide solution, dissolve and add 20ml of hydrazine hydrate solution dropwise, react at 80°C for 1h, and further dissolve in the above solution 20ml of 10wt% acetic acid aqueous solution was added dropwise, and the reaction was continued for 40min to obtain a stable graphene aqueous solution. Add 11wt% water-based polyacrylate, 0.15wt% ethanolamine, 0.15wt% monobutyl ether, 0.07wt% defoamer 901 to the above stable aqueous solution, and add 2.5wt% melamine formaldehyde, 0.5wt% water-based polyester % Ethylenediamine. Stirring at a temperature of 20°C for 30 minutes, a high-performance water-based graphene conductive coating can be obtained. The drying temperature of the coating is 50° C., and the drying time is 4 minutes.

Example 3

Under the condition of ice bath, add 3.0g of graphite into 60ml of concentrated sulfuric acid, stir vigorously for 30min, further add _12gKMnO4 into the above mixture, stir vigorously for 30min. Transfer the above mixed solution to a 30°C water bath, slowly add 18g NaNO ₃ , and stir for 60 minutes; while stirring, continuously add 140ml of deionized water to the above mixed solution, and then transfer it to an oil bath at a temperature of 90°C , stirred for 30 minutes; then added 18ml of H ₂ O ₂ dropwise, and continued to react for 60 minutes so that the solution changed from dark brown to bright yellow;

Under stirring conditions, add 2.5wt% graphene oxide dispersing agent PEG to the above graphene oxide solution, dissolve and add 20ml of hydrazine hydrate solution dropwise, react at 80°C for 1h, and further dissolve in the above solution 20ml15wt% acetic acid aqueous solution was added dropwise, and the reaction was continued for 50min to obtain a stable graphene aqueous solution. Add 15wt% water-based polyacrylate, 0.35wt% ethanolamine, 0.25wt% monobutyl ether, 0.07wt% defoamer 901 to the above stable aqueous solution, and add 1.5wt% melamine formaldehyde, 1.5wt% water-based polyester % Ethylenediamine. Stirring at a temperature of 20°C for 30 minutes, a high-performance water-based graphene conductive coating can be obtained. The drying temperature of the coating is 50° C., and the drying time is 2 minutes.

Example 4

Under the condition of ice bath, add 3.0g of graphite into 60ml of concentrated sulfuric acid, stir vigorously for 30min, further add _12gKMnO4 into the above mixture, stir vigorously for 30min. Transfer the above mixed solution to a 30°C water bath, slowly add 18g NaNO ₃ , and stir for 60 minutes; while stirring, continuously add 140ml of deionized water to the above mixed solution, and then transfer it to an oil bath at a temperature of 90°C , stirred for 30 minutes; then added 18ml of H ₂ O ₂ dropwise, and continued to react for 60 minutes so that the solution changed from dark brown to bright yellow;

Under stirring conditions, add 4.5wt% graphene oxide dispersing agent PEDOT:PSS to the above graphene oxide solution, dissolve and add 20ml of hydrazine hydrate solution dropwise, react at 70°C for 1h, and further 20ml10wt% acetic acid aqueous solution was added dropwise into the solution, and the reaction was continued for 40min to obtain a stable graphene aqueous solution. Add 11wt% water-based polyacrylate, 0.15wt% ethanolamine, 0.15wt% monobutyl ether, 0.07wt% defoamer 901 to the above stable aqueous solution, and add 2.5wt% melamine formaldehyde, 1.5wt% water-based polyester % Ethylenediamine. Stirring at a temperature of 20°C for 30 minutes, a high-performance water-based graphene conductive coating can be obtained. The drying temperature of the coating is 70°C, and the drying time is 50S.

Example 5

Under the condition of ice bath, add 3.0g of graphite into 60ml of concentrated sulfuric acid, stir vigorously for 30min, further add _12gKMnO4 into the above mixture, stir vigorously for 30min. Transfer the above mixed solution to a 30°C water bath, slowly add 18g NaNO ₃ , and stir for 60 minutes; while stirring, continuously add 140ml of deionized water to the above mixed solution, and then transfer it to an oil bath at a temperature of 90°C , stirred for 30 minutes; then added 18ml of H ₂ O ₂ dropwise, and continued to react for 60 minutes so that the solution changed from dark brown to bright yellow;

Under stirring conditions, add 4.5wt% dispersing agent PVP of graphene oxide to the above graphene oxide solution, add dropwise 20ml of hydrazine hydrate solution after dissolving, react at 40°C for 1h, and further dissolve in the above solution 20ml of 40wt% hydroiodic acid aqueous solution was added dropwise, and the reaction was continued for 40min to obtain a stable graphene aqueous solution. In the above stable aqueous solution, 17wt% water-based polyacrylate, 0.35wt% ethanolamine, 0.25wt% monobutyl ether, 0.05wt% defoamer 902, and 2.5wt% melamine for water-based polyester were sequentially added to the above-mentioned stable aqueous solution. Formaldehyde, 1.5wt% ethylenediamine. Stirring at a temperature of 20°C for 30 minutes, a high-performance water-based graphene conductive coating can be obtained. The drying temperature of the coating is 80°C, and the drying time is 30S.

Table 1. Electrical conductivity and mechanical properties of coatings prepared from coatings

Claims (10)

1. a high-performance water-based graphene conductive coating, is characterized in that, this electrically conducting coating is that conductive filler material forms by the Graphene of high conduction and high water stability.

2. the preparation method of a high-performance water-based graphene conductive coating, is characterized in that, step is as follows:

(1) under condition of ice bath, 0.5～5.0g graphite is joined in the vitriol oil of 40ml～60ml violent stirring 30min; Further with 12～30g KMnO ₄Join in above-mentioned mixed solution violent stirring 30min; Above-mentioned mixed solution is transferred in 30 ℃ of water-baths, slowly added 18～40gNaNO ₃, stir 60min; Under stirring state, 100～140ml deionized water is joined in above-mentioned mixed solution continuously, then it is transferred in the oil bath with 90 ℃ of temperature, stir the 30min time; Dropwise add again 12～20mlH ₂O ₂, continue reaction 40min～80min until solution becomes glassy yellow from dark-brown;

(2) under agitation condition, add a certain amount of dispersion reagent in above-mentioned glassy yellow graphene oxide solution, drip the hydrazine hydrate solution of 15～45ml after dissolving, react 1h at 40 ℃～80 ℃ temperature; Further drip also original reagent of 15～45ml in mentioned solution, continue reaction 20～60min, obtain stable graphene aqueous solution;

(3) add successively a certain amount of waterborne polyester, neutralizing agent, flow agent, defoamer, linking agent, catalytic reagent in the graphene aqueous solution of aforementioned stable, stir at a certain temperature certain hour, can obtain high-performance water-based graphene conductive coating.

3. the preparation method of watersoluble plumbago alkene electrically conducting coating as claimed in claim 2, is characterized in that, in step (2), dispersion reagent is PVP, PVA, PEG or PEDOT:PSS; Disperseing the concentration of aqueous solution of reagent is 0.5～20wt%.

4. the preparation method of watersoluble plumbago alkene electrically conducting coating as claimed in claim 2, is characterized in that, in step (2), going back original reagent is acetic acid or hydroiodic acid HI; Acetic acid aqueous solution concentration is 10～30wt%, and hydriodic acid aqueous solution concentration is 10～40wt%.

5. the preparation method of watersoluble plumbago alkene electrically conducting coating as claimed in claim 2, is characterized in that, in step (3), described waterborne polyester is, neutralizing agent is ethanolamines, and flow agent is only son's ethers, and defoamer is defoamer 901 or 902.

6. the preparation method of watersoluble plumbago alkene electrically conducting coating as described in claim 2 or 5, it is characterized in that, described waterborne polyester, neutralizing agent, flow agent, defoamer consumption are respectively 5～20wt%, 0.1～2wt%, 0.15～0.5wt%, the 0.02～0.1wt% that coating forms.

7. the preparation method of watersoluble plumbago alkene electrically conducting coating as claimed in claim 2, is characterized in that, described linking agent is melamino-formaldehyde or aminoresin class, and add-on is 5～25wt% of waterborne polyester.

8. the preparation method of watersoluble plumbago alkene electrically conducting coating as claimed in claim 2, is characterized in that, described catalytic reagent is ethylenediamines, and add-on is 0～2.0wt% of waterborne polyester.

9. the preparation method of watersoluble plumbago alkene electrically conducting coating as claimed in claim 2, is characterized in that, described coating whipping temp is 5～30 ℃, and churning time is 10min～3 hour.

10. the purposes of the watersoluble plumbago alkene electrically conducting coating of the described method preparation of claim 2 to 9, is characterized in that, this coating is used for spraying, spray ink Printing and typography and prepares coating; This coating is used in macromolecular material, metallic substance, ceramic surface, is used for electromagnetic shielding, antistatic, anticorrosion, heat radiation, wear-resisting and field of electronic circuitry.