阅读说明：本技术 一种轻质高性能导电涂料及其制备方法 (Light high-performance conductive coating and preparation method thereof ) 是由 张久霖 孙新 杨智慧 于海涛 贺军哲 于 2020-07-07 设计创作，主要内容包括：本发明涉及一种轻质高性能导电涂料及其制备方法。所述方法包括：采用分散剂和第一溶剂将包含树枝状纳米银粉和镍基还原氧化石墨粉的复合粉体分散均匀,得到复合粉体浆料；采用第二溶剂将防沉剂分散均匀,得到防沉剂溶液,采用第三溶剂将流平剂分散均匀,得到流平剂溶液,然后将所述防沉剂溶液和所述流平剂溶液加入树脂中并分散均匀,得到预混合浆料；用第四溶剂将所述复合粉体浆料、所述预混合浆料和消泡剂分散均匀,得到轻质高性能导电涂料。本发明制得的导电涂料较传统导电涂料具有生产成本低、轻质、高性能等明显优势,可满足吸波涂层基底、宽频段电磁屏蔽、静电消除等应用需求。(The invention relates to a light high-performance conductive coating and a preparation method thereof. The method comprises the following steps: uniformly dispersing the composite powder containing the dendritic nano silver powder and the nickel-based reduced graphite oxide powder by adopting a dispersing agent and a first solvent to obtain composite powder slurry; uniformly dispersing an anti-settling agent by using a second solvent to obtain an anti-settling agent solution, uniformly dispersing a leveling agent by using a third solvent to obtain a leveling agent solution, and then adding the anti-settling agent solution and the leveling agent solution into resin and uniformly dispersing to obtain premixed slurry; and (3) uniformly dispersing the composite powder slurry, the premixed slurry and the defoaming agent by using a fourth solvent to obtain the light high-performance conductive coating. Compared with the traditional conductive coating, the conductive coating prepared by the invention has the obvious advantages of low production cost, light weight, high performance and the like, and can meet the application requirements of a wave-absorbing coating substrate, wide-band electromagnetic shielding, static elimination and the like.)

1. The preparation method of the light high-performance conductive coating is characterized by comprising the following steps:

(1) uniformly dispersing the composite powder containing the dendritic nano silver powder and the nickel-based reduced graphite oxide powder by adopting a dispersing agent and a first solvent to obtain composite powder slurry;

(2) uniformly dispersing an anti-settling agent by using a second solvent to obtain an anti-settling agent solution, uniformly dispersing a leveling agent by using a third solvent to obtain a leveling agent solution, and then adding the anti-settling agent solution and the leveling agent solution into resin and uniformly dispersing to obtain premixed slurry; and

(3) and (3) uniformly dispersing the composite powder slurry, the premixed slurry and the defoaming agent by using a fourth solvent to obtain the light high-performance conductive coating.

2. The production method according to claim 1, further comprising, before performing step (1), a step of producing the dendritic silver nanopaste powder:

mixing a silver nitrate solution, an ascorbic acid solution and clove oil, performing ultrasonic treatment to obtain a mixed solution, and then sequentially performing centrifugal separation, washing and drying on the mixed solution to obtain the dendritic nano silver powder;

preferably, the silver nitrate solution and the clove oil are uniformly mixed to obtain a mixed solution containing the silver nitrate and the clove oil, and then the ascorbic acid solution is dropwise added into the mixed solution containing the silver nitrate and the clove oil and is subjected to ultrasonic treatment to obtain the mixed solution.

3. The method of claim 2, wherein:

the concentration of the silver nitrate solution is 0.05-0.1 mol/L, and the ratio of the amount of silver nitrate contained in the silver nitrate solution to the amount of ascorbic acid contained in the ascorbic acid solution is (2-3): 1; and/or

The ratio of the amount of silver nitrate contained in the silver nitrate solution to the amount of clove oil is 200 g: (3-5) mL; and/or

The ultrasonic treatment time is 40-80 min; and/or

The dripping speed of the ascorbic acid solution is 1-3 drops/s.

4. The method according to claim 1, further comprising, before performing step (1), a step of preparing the nickel-based reduced graphite oxide powder:

adding nickel chloride hexahydrate into a graphite oxide solution, performing ultrasonic dispersion to obtain a reaction solution, adjusting the pH of the reaction solution by using sodium hydroxide, adding hydrazine hydrate to perform reaction to obtain a reaction product, filtering the reaction product, and then sequentially performing washing, drying and grinding to obtain the nickel-based reduced graphite oxide powder.

5. The method of claim 4, wherein:

the mass ratio of the graphite oxide contained in the graphite oxide solution to the nickel chloride hexahydrate is (0.25-0.5): 1, and/or the dosage ratio of the graphite oxide contained in the graphite oxide solution to the hydrazine hydrate is 0.2 g: (10-20) mu L; and/or

Adjusting the pH value of the reaction solution to 10-12 by using sodium hydroxide; and/or the reaction temperature is 70-90 ℃, the reaction time is 3-5 h, and the reaction is carried out at a stirring speed of 600-1000 r/min.

6. The production method according to any one of claims 1 to 5, characterized in that:

the weight ratio of the composite powder, the resin, the leveling agent, the anti-settling agent, the dispersing agent and the defoaming agent in the light high-performance conductive coating is (40-60): (40-60): 3:1:2: 1.

7. the production method according to any one of claims 1 to 5, characterized in that:

in the step (1), the dispersant is propyl trimethoxy silane, the first solvent is absolute ethyl alcohol, the mass ratio of the dendritic nano silver powder to the nickel-based graphite oxide powder in the composite powder slurry is 1 (1-2), and the mass ratio of the propyl trimethoxy silane to the composite powder is 1 (20-30); and/or

In the step (2), the anti-settling agent is organic bentonite, the second solvent is a mixed solution of xylene and n-butyl alcohol, and the mass ratio of the xylene, the n-butyl alcohol and the organic bentonite in the anti-settling agent solution is (2-4): (6-8): 1, preferably 3:7: 1; and/or

In the step (2), the leveling agent is cellulose acetate butyrate, the third solvent is ethyl acetate, and the mass ratio of the cellulose acetate butyrate to the ethyl acetate in the leveling agent solution is 1 (15-25), preferably 1: 20; and/or

In the step (2), the resin is an acrylic resin; and/or

In the step (3), the defoaming agent is an acetylene glycol molecular defoaming agent, and the fourth solvent is absolute ethyl alcohol.

8. The method of claim 7, wherein:

the mass ratio of the organic bentonite to the cellulose acetate butyrate to the acrylic resin is 1:3 (40-60).

9. The production method according to any one of claims 1 to 5, characterized in that:

in the step (2), dispersing the anti-settling agent for 20-40 min by using the second solvent under the condition that the rotating speed is 200-400 r/min to obtain an anti-settling agent solution; and/or

In the step (2), dispersing the leveling agent for 20-40 min by using the third solvent under the condition that the rotating speed is 200-400 r/min to obtain a leveling agent solution; and/or

In the step (3), the composite powder slurry, the premixed slurry and the defoaming agent are dispersed for 1.5-3 hours by using the fourth solvent under the condition that the rotating speed is 600-1000 r/min, so that the light high-performance conductive coating is obtained.

10. A lightweight high-performance conductive coating material produced by the production method according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of conductive paint preparation, and particularly relates to a light high-performance conductive paint and a preparation method thereof.

Background

The conductive paint is mainly sprayed or scraped on a non-conductive substrate, so that the conductive paint has certain current conduction and static charge dissipation capacity. The conductive coating mainly depends on the mutual contact of conductive fillers to form a continuous conductive network chain, and when the conductive fillers exceed the percolation threshold value, the fillers are in contact with each other or are close to each other, so that current carriers can move on the network chain, and the coating has a conductive function. Currently, the method is commonly used for eliminating static electricity, electromagnetic shielding, electric heating and corrosion prevention.

In the field of wave-absorbing materials, the energy conversion mechanism of the wave-absorbing coating to electromagnetic waves is usually attributed to multiple interference losses, namely, a substrate with higher conductivity, such as metal, carbon fiber and the like, is required below the wave-absorbing coating. After the electromagnetic wave passes through the coating, the electromagnetic wave is reflected on the conductive base body to realize secondary energy attenuation of the electromagnetic wave, so that the surface of the base material such as glass fiber and the like needs to be subjected to conductive treatment by using the conductive coating before the base material is subjected to low-scattering treatment by using the wave-absorbing coating.

At present, the conductive filler of the conductive coating mainly comprises silver powder, which has high conductivity and stability, but the conductive filler is expensive, and the surface density of part of the coating exceeds the requirements, so that the development of the light high-performance conductive coating is the key for realizing the conductivity and the wave absorption performance of the non-metal part.

Disclosure of Invention

The invention provides a light high-performance conductive coating and a preparation method thereof, aiming at solving the technical problems that the conductive coating in the prior art is expensive and the areal density exceeds the standard.

In order to achieve the above object, the present invention provides, in a first aspect, a method for preparing a lightweight high-performance conductive coating material, the method comprising the steps of:

(1) uniformly dispersing the composite powder containing the dendritic nano silver powder and the nickel-based reduced graphite oxide powder by adopting a dispersing agent and a first solvent to obtain composite powder slurry;

(2) uniformly dispersing an anti-settling agent by using a second solvent to obtain an anti-settling agent solution, uniformly dispersing a leveling agent by using a third solvent to obtain a leveling agent solution, and then adding the anti-settling agent solution and the leveling agent solution into resin and uniformly dispersing to obtain premixed slurry; and

(3) and (3) uniformly dispersing the composite powder slurry, the premixed slurry and the defoaming agent by using a fourth solvent to obtain the light high-performance conductive coating.

Preferably, before the step (1), the preparation method further comprises the following steps: mixing a silver nitrate solution, an ascorbic acid solution and clove oil, performing ultrasonic treatment to obtain a mixed solution, and then sequentially performing centrifugal separation, washing and drying on the mixed solution to obtain the dendritic nano silver powder; preferably, the silver nitrate solution and the clove oil are uniformly mixed to obtain a mixed solution containing the silver nitrate and the clove oil, and then the ascorbic acid solution is dropwise added into the mixed solution containing the silver nitrate and the clove oil and is subjected to ultrasonic treatment to obtain the mixed solution.

Preferably, the concentration of the silver nitrate solution is 0.05-0.1 mol/L, and the ratio of the amount of the silver nitrate contained in the silver nitrate solution to the amount of the ascorbic acid contained in the ascorbic acid solution is (2-3): 1; and/or the ratio of the dosage of the silver nitrate contained in the silver nitrate solution to the dosage of the clove oil is 200 g: (3-5) mL; and/or the time of ultrasonic treatment is 40-80 min; and/or the dripping speed of the ascorbic acid solution is 1-3 drops/s.

Preferably, before step (1), the preparation method further comprises the following steps: adding nickel chloride hexahydrate into a graphite oxide solution, performing ultrasonic dispersion to obtain a reaction solution, adjusting the pH of the reaction solution by using sodium hydroxide, adding hydrazine hydrate to perform reaction to obtain a reaction product, filtering the reaction product, and then sequentially performing washing, drying and grinding to obtain the nickel-based reduced graphite oxide powder.

Preferably, the mass ratio of the graphite oxide contained in the graphite oxide solution to the nickel chloride hexahydrate is (0.25-0.5): 1, and/or the ratio of the graphite oxide contained in the graphite oxide solution to the amount of hydrazine hydrate is 0.2 g: (10-20) mu L; and/or adjusting the pH value of the reaction solution to 10-12 by using sodium hydroxide; and/or the reaction temperature is 70-90 ℃, the reaction time is 3-5 h, and the reaction is carried out at a stirring speed of 600-1000 r/min.

Preferably, the weight ratio of the composite powder, the resin, the leveling agent, the anti-settling agent, the dispersing agent and the defoaming agent in the light high-performance conductive coating is (40-60): (40-60): 3:1:2: 1.

preferably, in the step (1), the dispersant is propyl trimethoxy silane, the first solvent is absolute ethyl alcohol, the mass ratio of the dendritic nano silver powder to the nickel-based graphite oxide powder in the composite powder slurry is 1 (1-2), and the mass ratio of the propyl trimethoxy silane to the composite powder is 1 (20-30); and/or in the step (2), the anti-settling agent is organic bentonite, the second solvent is a mixed solution of xylene and n-butyl alcohol, and the mass ratio of the xylene, the n-butyl alcohol and the organic bentonite in the anti-settling agent solution is (2-4): 1 (6-8): 1, preferably 3:7: 1; and/or in the step (2), the leveling agent is cellulose acetate butyrate, the third solvent is ethyl acetate, and the mass ratio of the cellulose acetate butyrate to the ethyl acetate in the leveling agent solution is 1 (15-25), preferably 1: 20; and/or in step (2), the resin is an acrylic resin; and/or in the step (3), the defoaming agent is an alkyne diol molecular defoaming agent, and the fourth solvent is absolute ethyl alcohol.

Preferably, the mass ratio of the organic bentonite to the cellulose acetate butyrate to the acrylic resin is 1:3 (40-60).

Preferably, in the step (2), the second solvent is adopted to disperse the anti-settling agent for 20-40 min under the condition that the rotating speed is 200-400 r/min, so as to obtain the anti-settling agent solution; and/or in the step (2), dispersing the leveling agent for 20-40 min by adopting the third solvent under the condition that the rotating speed is 200-400 r/min to obtain a leveling agent solution; and/or in the step (3), dispersing the composite powder slurry, the premixed slurry and the defoaming agent for 1.5-3 hours by using the fourth solvent under the condition that the rotating speed is 600-1000 r/min to obtain the light high-performance conductive coating.

The present invention provides, in a second aspect, a lightweight high-performance conductive coating produced by the production method according to the first aspect of the present invention.

Compared with the prior art, the invention at least has the following beneficial effects:

(1) the existing traditional metal conductive filler such as gold and silver conductive particles have good conductivity, so that the coating has good conductivity, but is mainly used in some special fields due to high price and high cost. The invention explores a route for synthesizing the conductive coating in an economic, effective and environment-friendly green way, and gives consideration to the reasonable means of conductivity and economic index; the conductive coating can be constructed by various convenient processes such as brushing, spraying, blade coating and the like, and is convenient for the conductive requirements of various non-metal parts such as planes, curved surfaces, gaps and the like.

(2) The conductive filler is prepared by mixing the dendritic nano silver powder and the nickel-based reduced graphite oxide, the bottleneck of large surface density of the traditional silver-based conductive powder is broken through, the conductive performance is excellent, and the conductive filler can be applied to scenes including wave-absorbing coating substrates, wide-frequency-band electromagnetic shielding, static elimination and the like.

Drawings

FIG. 1 is a schematic diagram of the preparation process of the light-weight high-performance conductive coating of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The invention provides a preparation method of a light high-performance conductive coating, which comprises the following steps:

(1) uniformly dispersing the composite powder containing the dendritic nano silver powder and the nickel-based reduced graphite oxide powder by adopting a dispersing agent and a first solvent to obtain composite powder slurry (mixed conductive filler slurry);

(2) uniformly dispersing an anti-settling agent by using a second solvent to obtain an anti-settling agent solution, uniformly dispersing a leveling agent by using a third solvent to obtain a leveling agent solution, and then adding the anti-settling agent solution and the leveling agent solution into resin and uniformly dispersing to obtain premixed slurry; in the invention, for example, the anti-settling agent solution and the leveling agent solution are added into resin, and high-speed dispersion is carried out by using a high-speed dispersion machine, wherein the rotating speed is 1000-1500 r/min, preferably 1200r/min, and the high-speed dispersion time is 20-40 min, preferably 30 min;

(3) uniformly dispersing the composite powder slurry, the premixed slurry and the defoaming agent by using a fourth solvent to obtain a light high-performance conductive coating (a conductive coating A component); in the invention, for example, the composite powder slurry, the premixed slurry, the defoaming agent and the fourth solvent are blended and added into a dispersion machine for dispersion, and finally, the uniform component A of the conductive coating is obtained; the fourth solvent (e.g., absolute ethanol) may be added as required by the solids content of the coating.

It is known that the traditional metal conductive filler such as gold and silver conductive particles have good conductivity, so that the coating has good conductivity, but the traditional metal conductive filler is mainly used in some special fields due to high price and high cost. The invention adopts the composite powder containing the dendritic nano silver powder and the nickel-based reduced graphite oxide powder as the mixed conductive filler of the light high-performance conductive coating, and has the following two benefits: firstly, the single dendritic nano silver powder is high in price, and the cost can be reduced to a certain extent on the premise of reaching the conductivity after the single dendritic nano silver powder is blended with nickel-based reduced graphite oxide powder; secondly, considering that the coating can be applied to an electromagnetic shielding system, the defect of insufficient electromagnetic shielding effectiveness of single silver powder at a low frequency position can be improved after the nickel-based reduced graphite oxide powder is added, and the full-band shielding effectiveness is improved.

The method firstly prepares the composite powder slurry, can ensure the uniformity of the dendritic nano silver powder and the nickel-based reduced graphite oxide powder in a system, secondly prepares the premixed slurry, adds the flatting agent and the anti-settling agent into the resin to form a viscous resin solution which is not easy to settle, and is convenient for further wetting by subsequently adding the composite powder slurry. If the one-pot blending method is adopted, namely the components such as the dendritic nano silver powder, the nickel-based reduced graphite oxide, the resin, the anti-settling agent, the leveling agent, the dispersing agent, the defoaming agent and the like are directly blended, the two kinds of powder of the dendritic nano silver powder and the nickel-based reduced graphite oxide are not easy to disperse and are easy to agglomerate respectively, and the distribution state in the resin is not the same as that in the step-by-step method adopted by the invention; in addition, the coating prepared by the one-pot method is easy to have large particle on the surface after being sprayed, and the surface of the coating is not flat.

The invention explores a route for synthesizing the conductive coating in an economic, effective and environment-friendly way, and gives consideration to the reasonable means of conductivity and economic index; the preparation method of the light high-performance conductive coating provided by the invention is simple, convenient and feasible, and on one hand, the light weight of a paint film is realized while the manufacturing cost of the conductive coating is reduced; on the other hand, the raw materials and the production process selected by the invention have basic conditions for carrying out batch production, the equipment and the raw materials are common, the operation and the production are simple, the application requirements of spraying, blade coating, brush coating and the like can be met, and the conductive requirements of various non-metal parts such as planes, curved surfaces, gaps and the like are facilitated. The conductive filler is prepared by mixing the dendritic nano silver powder and the nickel-based reduced graphite oxide, the bottleneck of large surface density of the traditional silver-based conductive powder is broken through, the conductive performance is excellent, and the conductive filler can be applied to scenes including wave-absorbing coating substrates, wide-frequency-band electromagnetic shielding, static elimination and the like.

According to some preferred embodiments, before step (1), the method further comprises the following steps: mixing a silver nitrate solution (such as a silver nitrate ethanol solution), an ascorbic acid solution (an ascorbic acid ethanol solution) and clove oil, performing ultrasonic treatment to obtain a mixed solution, and then sequentially performing centrifugal separation, washing and drying on the mixed solution to obtain the dendritic nano silver powder; preferably, the silver nitrate solution and the clove oil are uniformly mixed to obtain a mixed solution containing the silver nitrate and the clove oil, and then the ascorbic acid solution is dropwise added into the mixed solution containing the silver nitrate and the clove oil and is subjected to ultrasonic treatment to obtain the mixed solution. The preparation of the dendritic nano silver powder adopts an economic, effective and environment-friendly green synthesis route and a reasonable means of taking both conductivity and economic index into consideration. Compared with the traditional nano-silver preparation method, such as vacuum evaporation, electrochemical reduction and the like, the method is simple and convenient, the yield is high, and the environmental pollution is small.

According to some preferred embodiments, the concentration of the silver nitrate solution is 0.05 to 0.1mol/L (e.g. 0.05, 0.06, 0.07, 0.08, 0.09, or 0.1mol/L), and the ratio of the amount of silver nitrate contained in the silver nitrate solution to the amount of ascorbic acid contained in the ascorbic acid solution is (2 to 3): 1 (e.g., 2:1, 2.5:1, or 3: 1); and/or the ratio of the dosage of the silver nitrate contained in the silver nitrate solution to the dosage of the clove oil is 200 g: (3-5) mL, namely when the mass of silver nitrate in the silver nitrate solution is 200g, the using amount of the clove oil is 3-5 mL (such as 3, 3.5, 4, 4.5 or 5 mL); and/or the time of the ultrasonic treatment is 40-80 min (for example 40, 50, 60, 70 or 80 min); and/or the dripping speed of the ascorbic acid solution is 1-3 drops/s.

According to some preferred embodiments, before step (1), the method further comprises the step of preparing the nickel-based reduced graphite oxide powder: adding nickel chloride hexahydrate into a graphite oxide solution, performing ultrasonic dispersion to obtain a reaction solution, adjusting the pH of the reaction solution by using sodium hydroxide, adding hydrazine hydrate to perform reaction (for example, stirring and reacting for 4 hours at 80 ℃) to obtain a reaction product, filtering the reaction product, and then sequentially performing washing, drying and grinding to obtain the nickel-based reduced graphite oxide powder. In the invention, nickel (Ni) particles are loaded on graphite oxide to be reduced together to obtain the conductive filler 'nickel-based reduced graphite oxide powder'.

According to some preferred embodiments, the mass ratio of the graphite oxide contained in the graphite oxide solution to the nickel chloride hexahydrate is (0.25-0.5): 1 (e.g. 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1 or 0.5:1), and/or the ratio of the amount of graphite oxide contained in the graphite oxide solution to the hydrazine hydrate is 0.2 g: (10-20) mu L, namely when the mass of the graphite oxide contained in the graphite oxide solution is 0.2g, the dosage of the hydrazine hydrate is (10-20) mu L; and/or adjusting the pH of the reaction solution to 10-12 (for example, 10, 11 or 12) by using sodium hydroxide, and preferably to 11; and/or the reaction temperature is 70-90 ℃ (for example 70 ℃, 75 ℃, 80 ℃, 85 ℃ or 90 ℃) and preferably 80 ℃, the reaction time is 3-5 h (for example 3, 3.5, 4, 4.5 or 5h) and preferably 4h, and the reaction is carried out at a stirring speed of 600-1000 r/min (for example 600, 700, 800, 900 or 1000r/min) and preferably 800 r/min.

According to some preferred embodiments, the weight ratio of the composite powder, the resin, the leveling agent, the anti-settling agent, the dispersing agent and the defoaming agent in the light high-performance conductive coating is (40-60): (40-60): 3:1:2:1 (e.g., 40:40:3:1:2:1, 40:50:3:1:2:1, 40:60:3:1:2:1, 50:40:3:1:2:1, 50:50:3:1:2:1, 50:60:3:1:2:1, 60:40:3:1:2:1, 60:50:3:1:2:1 or 60:60:3:1:2: 1). The addition proportion of each component is obtained through a large number of tests, particularly the proportion of the mixed conductive filler (composite powder) containing dendritic nano silver powder and nickel-based reduced graphite oxide powder to resin is too high or too low, which affects the conductivity and the coating surface state, and the invention preferably selects the mass ratio of the usage amounts of the composite powder, the resin, the flatting agent, the anti-settling agent, the dispersing agent and the defoaming agent contained in the light high-performance conductive coating to be (40-60): (40-60): 3:1:2:1, the optimal preparation ratio is constrained between the conductivity and the coating surface state, and the conductivity and the coating surface state are considered to a certain extent.

According to some preferred embodiments, in the step (1), the dispersant is propyl trimethoxysilane, the first solvent is absolute ethyl alcohol, the mass ratio of the dendritic silver nanopowder to the nickel-based graphite oxide powder in the composite powder slurry is 1 (1-2) (e.g., 1:1, 1:1.5 or 1:2), and the mass ratio of the propyl trimethoxysilane to the composite powder is 1 (20-30) (e.g., 1:20, 1:25 or 1: 30); in the preparation process of the composite powder slurry, the adding proportion of the dendritic nano silver powder, the nickel-based graphite oxide powder and the propyl trimethoxy silane is obtained through a large number of tests, the proportion of the dendritic nano silver powder and the nickel-based reduced graphite oxide powder is determined through a large number of tests according to the requirements of conductivity and surface density, the dendritic nano silver powder has excessive conductivity and is deviated and higher in cost, the higher content of the nickel-based graphite oxide powder has the same conductivity which is not as good as the comprehensive conductivity obtained by mixing the dendritic nano silver powder, the nickel-based graphite oxide powder and the nickel-based reduced graphite oxide powder according to the preferable proportion, and the surface density is higher.

According to some preferred embodiments, in the step (2), the anti-settling agent is organic bentonite, the second solvent is a mixed solution of xylene and n-butanol, and the mass ratio of the xylene, the n-butanol and the organic bentonite in the anti-settling agent solution is (2-4): (6-8): 1 (e.g. 2:6:1, 2:7:1, 2:8:1, 3:6:1, 3:7:1, 3:8:1, 4:6:1, 4:7:1 or 4:8:1), preferably 3:7: 1; and/or in the step (2), the leveling agent is cellulose acetate butyrate, the third solvent is ethyl acetate, and the mass ratio of the cellulose acetate butyrate to the ethyl acetate in the leveling agent solution is 1 (15-25) (for example, 1:15, 1:20 or 1:25), preferably 1: 20; and/or in step (2), the resin is an acrylic resin; the premixed slurry mainly plays a role of providing a good matrix for the dendritic nano silver powder and the nickel-based reduced graphite oxide powder conductive filler, and finally influences the states of the coating and the coating in aspects of wettability, viscosity, solubility and the like.

According to some preferred embodiments, in step (3), the antifoaming agent is an acetylenic diol molecular antifoaming agent (DF-80L), and the fourth solvent is absolute ethanol.

According to some preferred embodiments, the mass ratio of the organobentonite (anti-settling agent), the cellulose acetate butyrate (leveling agent), and the acrylic resin contained in the pre-mixed slurry is 1:3 (40 to 60) (e.g., 1:3:40, 1:3:45, 1:3:50, 1:3:55, or 1:3: 60). In the invention, the preferred mass ratio of the organic bentonite to the cellulose acetate butyrate to the acrylic resin is 1:3 (40-60), the ratio is determined by the viscosity of the premixed slurry, the apparent state of the final coating and the state of the coating, the organic bentonite is too little, and the coating is easy to settle; cellulose acetate butyrate is too little, and large particles are easy to appear on the surface of the coating.

According to some preferred embodiments, in the step (2), the anti-settling agent is dispersed with the second solvent at a rotation speed of 200 to 400r/min (e.g. 200, 300 or 400r/min), preferably 300r/min, for 20 to 40min (e.g. 20, 25, 30, 35 or 40min), preferably 30min, to obtain the anti-settling agent solution; and/or in the step (2), dispersing the leveling agent for 20-40 min (for example, 20, 25, 30, 35 or 40min) and preferably for 30min by using the third solvent under the condition that the rotating speed is 200-400 r/min (for example, 200, 300 or 400r/min) and preferably 300r/min to obtain the leveling agent solution; and/or in the step (3), dispersing the composite powder slurry, the premixed slurry and the defoaming agent for 1.5-3 h (for example, 1.5, 2, 2.5 or 3h) by using the fourth solvent under the condition that the rotating speed is 600-1000 r/min (for example, 600, 700, 800, 900 or 1000r/min) to obtain the light high-performance conductive coating.

According to some specific embodiments, the preparation of the light-weight high-performance conductive coating comprises the following steps:

(a) preparing dendritic nano silver powder: mixing substances such as silver nitrate, ascorbic acid and clove oil according to a proportion, performing ultrasonic treatment, performing centrifugal separation, washing with absolute ethyl alcohol, and drying to obtain dendritic nano silver powder; in some embodiments, silver nitrate and ascorbic acid are preferably mixed with absolute ethyl alcohol respectively, the concentration of the silver nitrate solution is 0.05 mol/L-0.1 mol/L, and the amount ratio of the silver nitrate to the ascorbic acid substances is (2-3): 1, preferentially mixing a silver nitrate solution with clove oil, wherein the using amount of the clove oil is 3-5 mL, adding ascorbic acid in a gradually dropping mode, the adding speed of the ascorbic acid solution is 1-3 drops/s, and the time of ultrasonic treatment is 1 h.

(b) Preparing nickel-based reduced graphite oxide: weighing a certain amount of graphite oxide solution, adding nickel chloride hexahydrate, performing ultrasonic dispersion, adding sodium hydroxide to adjust the pH value of the solution, adding hydrazine hydrate, and stirring at 80 ℃ for reaction for 4 hours. After the reaction is finished, filtering, washing, drying and grinding the product to obtain nickel-based reduced graphite oxide powder (nickel-based reduced graphite oxide powder); in some embodiments, the mass ratio of graphite oxide to nickel chloride hexahydrate is (0.25-0.5): 1, when the mass of the graphite oxide is 0.2g, the using amount of hydrazine hydrate is 10-20 mu L, the pH value of the solution is adjusted to 11 after the sodium hydroxide is added, the stirring speed is 800r/min, and the solution is stirred while being heated.

(c) Preparing premixed slurry: dissolving the anti-settling agent and the leveling agent by using solvents respectively, adding the anti-settling agent and the leveling agent into resin, and dispersing the resin at a high speed for 30min by using a high-speed dispersion machine at a rotating speed of 1200 r/min; in some embodiments, the anti-settling agent is organobentonite, the leveling agent is cellulose acetate butyrate, and the resin is acrylic resin; the organic bentonite solvent (second solvent) is a mixed solution of xylene and n-butanol, and the ratio of xylene: n-butanol: the mass ratio of the organic bentonite is 3:7:1, the dispersion condition of the organic bentonite is that the rotating speed is 300r/min, and the stirring is carried out for 30 min; the cellulose acetate butyrate dispersion solvent (third solvent) is ethyl acetate, cellulose acetate butyrate: the mass ratio of ethyl acetate is 1:20, stirring for 30min under the condition that the dispersion condition of the cellulose acetate butyrate is 300 r/min; organic bentonite: cellulose acetate butyrate: the mass ratio of the acrylic resin is 1:3: (40-60).

(d) Preparing composite powder slurry: dispersing the dendritic nano silver powder and the nickel-based graphite oxide powder, adding the two kinds of powder, a dispersing agent and a solvent according to a ratio, and dispersing at a high speed of a high-speed dispersing machine at a rotating speed of 600r/min for 30 min; in some embodiments, the dispersant is propyl trimethoxysilane, the solvent is absolute ethanol, and the solvent can be added according to the solid content requirement of the coating; propyl trimethoxy silane: the mass ratio of the conductive powder (composite powder) is 1: (20-30), dendritic nano silver powder: the mass ratio of the nickel-based graphite oxide powder is 1: (1-2).

(e) Blending the coating: blending the composite powder slurry, the premixed slurry, the defoaming agent and the solvent, and adding the mixture into a dispersion machine for dispersion to finally obtain a uniform conductive coating A component; in some embodiments, the defoamer is selected from an alkyne diol molecular defoamer (DF-80L), the solvent is absolute ethyl alcohol, and the solvent can be added according to the solid content requirement of the coating; the rotating speed of the dispersion machine is 800r/min, and the dispersion time is 2h, so that the component A of the coating is obtained; the final mass ratio of the component A is composite powder: acrylic resin: cellulose acetate butyrate: organic bentonite: propyltrimethoxysilane (40-60): (40-60): 3:1:2, the addition amount of the absolute ethyl alcohol can be determined by the solid content and the construction requirement.

The present invention provides, in a second aspect, a lightweight high-performance conductive coating produced by the production method according to the first aspect of the present invention. Compared with the traditional conductive coating, the conductive coating prepared by the invention has the obvious advantages of low production cost, light weight, high performance and the like, and can meet the application requirements of a wave-absorbing coating substrate, wide-band electromagnetic shielding, static elimination and the like.

The present invention will be further described with reference to the following examples. These examples are merely illustrative of preferred embodiments of the present invention and the scope of the present invention should not be construed as being limited to these examples.