Metal nanoparticle loaded and modified graphene and carbon nanotube composite material conductive ink and preparation method thereof

Abstract

The invention relates to metal nanoparticle loaded and modified graphene and carbon nanotube composite material conductive ink and a preparation method thereof. The metal nanoparticle loaded and modified graphene and carbon nanotube composite material conductive ink is prepared from the following raw materials in parts by weight: 30 to 300 parts of metal nanoparticle loaded and modified graphene and carbon nanotube composite material, 100 to 400 parts of glass powder, 100 to 300 parts of resin, 200 to 400 parts of solvent, 20 to 80 parts of dispersing agent, 10 to 60 parts of flatting agent and 0.2 to 3 parts of defoaming agent, the conductive ink disclosed by the invention has relatively low sheet resistance and excellent conductivity.

Description

Technical Field

[0001] The invention relates to the technical field of conductive inks, and in particular to a metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink and a preparation method thereof. Background Art

[0002] At present, the high-temperature conductive ink on the market is mainly used for heating of high-power devices. High-temperature conductive ink generally uses precious metal materials as conductive fillers. On the one hand, precious metal materials are expensive and are greatly affected by market price fluctuations. On the other hand, with the development of the market, the requirements for high-power devices are getting higher and higher. Only using precious metals as fillers can no longer meet the market demand for conductive inks with higher conductivity and lower square resistance. This requires fillers with higher conductivity as conductive fillers for conductive inks.

[0003] Graphene and carbon nanotubes have extremely high electrical and thermal conductivity, and using them as conductive fillers for high-temperature resistant conductive inks has great market application prospects. However, due to the large specific surface area of ​​graphene, it is very easy to agglomerate in the system and is not easy to disperse; carbon nanotubes have a very large relative length, and are very easy to agglomerate and entangle with each other, and are not easy to disperse. Therefore, the excellent electrical conductivity of graphene and carbon nanotubes cannot be fully utilized, which affects the physical properties and printing adaptability of conductive inks. The invention patent with application number CN104212242B discloses a method for preparing graphene and carbon nanotube conductive inks for inkjet. The dispersion of graphene and carbon nanotubes in this patent adopts physical dispersion, and there is still agglomeration problem after a long time, which affects the conductive properties of conductive inks.

[0004] How to construct a three-dimensional conductive network of fillers, improve the conductivity of conductive inks and make them evenly dispersed in the resin system is a key issue in the current field of graphene and carbon nanotube conductive inks. Summary of the invention

[0005] Based on this, the present invention provides a metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink and a preparation method thereof, which solves the problem of easy agglomeration of graphene and carbon nanotubes and improves the conductivity of the graphene / carbon nanotube conductive ink.

[0006] The first aspect of the present invention provides a metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink, and the technical scheme thereof is as follows: A metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink, comprising the following raw materials in parts by weight: 30-300 parts of metal nanoparticle-loaded modified graphene / carbon nanotube / composite material, 100-400 parts of glass powder, 100-300 parts of resin, 200-400 parts of a first solvent, 20-80 parts of a dispersant, 10-60 parts of a leveling agent, and 0.2-3 parts of a defoaming agent; In some embodiments, the method for preparing a metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink comprises the following steps: Step a: Preparation of graphene@carbon nanotube composite material The reduced graphene oxide, additives, catalysts, and second solvents are mixed uniformly in a weight ratio of 1: (1-20): (0.5-25): (50-150), and dried at 40-100°C for 0.5-3 hours to obtain a dry mixture. The dry mixture is placed in a tubular furnace, the inlet valve and outlet valve of the furnace chamber are opened, and the furnace chamber is kept at one atmosphere. The furnace chamber is heated through the first heating stage, the first insulation stage, the second heating stage, and the second insulation stage. In the first heating stage, the first insulation stage, and the second heating stage, a protective atmosphere and hydrogen are introduced, and the protective atmosphere flow rate is 50-200 sccm, and the hydrogen flow rate is 10-100 sccm. Then, methane and hydrogen are introduced in the second insulation stage, and the methane flow rate is 5-100 sccm and the hydrogen flow rate is 10-300 sccm. The obtained substance is a graphene / carbon nanotube composite material. This step mainly uses specific additives and catalysts to grow carbon nanotubes on reduced graphene oxide.

[0007] The size of the reduced graphene oxide is 10-50 μm, and the specific surface area is 100-400 m 2 / g. The additive is at least one of cyanamide, dicyandiamide, melamine, urea and thiourea.

[0008] The catalyst is at least one of copper chloride and its hydrated compounds, copper sulfate and its hydrated compounds, copper nitrate and its hydrated compounds.

[0009] The second solvent is at least one of ethanol and deionized water.

[0010] The first heating stage is heating from room temperature to 450~650℃, with a heating rate of 5~10℃ / min; the first insulation stage is insulation at 450~650℃ for 15min~2H; the second heating stage is heating from 450~650℃ to 750~900℃, with a heating rate of 5~10℃ / min; the second insulation stage is insulation at 750~900℃ for 15min~1H.

[0011] The protective gas is at least one of nitrogen and argon.

[0012] Step b: Prepare graphene@carbon nanotube composite materials modified by metal nanoparticle loading.

[0013] The graphene@carbon nanotubes and metal precursors are prepared by physical or chemical methods to obtain metal nanoparticle-loaded and modified graphene@carbon nanotube composite materials. Among them, the metal precursor is at least one of salts containing metal ions, metal powders and metal targets, including at least one of gold salts, silver salts, copper salts, gold powder, silver powder, copper powder, gold target, silver target and copper target.

[0014] The physical or chemical method includes any one of magnetron sputtering, physical and chemical vapor deposition, electroplating, and chemical plating.

[0015] The graphene / carbon nanotube / metal composite material includes any one of a graphene@carbon nanotube composite material modified by gold nanoparticle loading, a graphene@carbon nanotube composite material modified by silver nanoparticle loading, and a graphene@carbon nanotube composite material modified by copper nanoparticle loading.

[0016] In some of the embodiments, the carbon nanotubes of the graphene@carbon nanotube composite material have a diameter of 1-50 nm and a length of 10-30 μm; the metal nanoparticles in the metal nanoparticle-loaded and modified graphene@carbon nanotube composite material have a particle size of 1-500 nm.

[0017] In some embodiments, the melting range of the glass powder is 600~800℃; the glass powder includes the following components in mass percentage: 30~55% SiO2, 10~35% Al2O3, 5~15% ZnO, 3~5% MgO, 1~5% SnO2; the particle size of the glass powder is 1~20μm.

[0018] In some embodiments, the resin is one or more of acrylic resin, polyester resin, and epoxy resin.

[0019] In some embodiments, the first solvent is at least one of xylene, NN dimethylformamide, n-butanol, ethylene glycol butyl ether, and diethylene glycol butyl ether acetate.

[0020] In some embodiments, the dispersant is selected from at least one of a carboxylate dispersant, an aliphatic amide dispersant and an ester dispersant.

[0021] In some embodiments, the leveling agent is at least one of polyether and polyether-modified polysiloxane; and the defoaming agent is at least one of mineral oil and silicone.

[0022] The second aspect of the present invention provides a method for preparing a metal nanoparticle-loaded modified graphene@carbon nanotube conductive ink, and the technical scheme thereof is as follows: A method for preparing a metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink comprises the following steps: S1 Accurately weigh each component.

[0023] S2: Add glass powder, resin, solvent, dispersant and leveling agent in a dispersion tank in sequence, and use a planetary mixer to stir for 5 to 60 minutes at 500 to 2000 r / min; then add the weighed metal nanoparticle-loaded modified graphene@carbon nanotube composite material, and stir for 20 to 60 minutes at 800 to 3000 r / min; finally, add the defoaming agent and stir for 5 to 30 minutes at 500 to 2000 r / min.

[0024] S3 The mixed slurry is ground using a three-roll grinder for 3 to 5 times, and the slurry fineness is controlled below 15 μm, thereby obtaining a graphene@carbon nanotube composite conductive ink modified by metal nanoparticles.

[0025] Another object of the present invention is to provide a curing method for a graphene@carbon nanotube conductive ink modified by metal nanoparticle loading, and the specific method is: the curing temperature of the graphene@carbon nanotube conductive ink modified by metal nanoparticle loading is segmented sintering, the first segment sintering temperature is 80~150℃, and the time is 10~30min; the second segment sintering temperature is 200~350℃, and the time is 10~30min; the third segment sintering temperature is 500~800℃, and the time is 10min~60min; then cooling to room temperature, the curing is completed.

[0026] The inventors of the present invention studied the factors affecting the conductivity of the conductive ink of the metal nanoparticle-loaded modified graphene@carbon nanotube composite material and found that the conductivity of the conductive ink of the metal nanoparticle-loaded modified graphene@carbon nanotube composite material is not only related to the quality of graphene and carbon nanotubes, but also related to the dispersibility of graphene and carbon nanotubes in the ink, thus forming the technical scheme of the present invention. The present invention selects the metal nanoparticle-loaded modified graphene@carbon nanotube composite material as a conductive filler, and the prepared nanomaterial has both excellent conductivity and is not easy to agglomerate. Compared with the traditional scheme, the conductive ink of the metal nanoparticle-loaded modified graphene@carbon nanotube composite material of the present invention has the following advantages: 1. The graphene / carbon nanotube composite material is a carbon nanotube grown on graphene, which belongs to CC single bond covalent bonding, is not easy to separate, and forms a BLOCK mode, which prevents the graphene sheets and the carbon tubes from agglomerating with each other, and improves the dispersibility of the composite material in the conductive ink. 2. In the metal nanoparticle-modified graphene@carbon nanotube composite material, the metal nanoparticles belong to zero-dimensional nanomaterials, carbon nanotubes belong to one-dimensional nanomaterials, and graphene belongs to two-dimensional nanomaterials. The three-dimensional nanomaterials are combined with each other to form a three-dimensional network structure in the system, forming a complete conductive path and improving the conductivity of the conductive ink. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with specific embodiments. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0029] The following is further described in conjunction with specific examples and comparative examples. The raw materials involved in the following specific examples, unless otherwise specified, can all be sourced from commercial sources. The instruments used, unless otherwise specified, can all be sourced from commercial sources. The processes involved, unless otherwise specified, are all routinely selected by those skilled in the art. Example 1

[0030] The first aspect of the present invention provides a metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink, and the technical scheme thereof is as follows: A metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is composed of the following raw materials in parts by weight: 80 parts of metal nanoparticle-loaded modified graphene / carbon nanotube / composite material, 300 parts of glass powder, 200 parts of resin, 300 parts of a first solvent, 50 parts of a dispersant, 40 parts of a leveling agent, and 1 part of a defoaming agent.

[0031] The metal nanoparticle-modified graphene@carbon nanotube composite material method comprises the following steps: Step a: Preparation of graphene@carbon nanotube composite material The reduced graphene oxide, additive, catalyst and second solvent are mixed in a ratio of 1:15:5:100 and dried at 80°C for 2 hours to obtain a dry mixture. The dry mixture is placed in a tubular furnace, the air inlet valve and the air outlet valve of the furnace chamber are opened, and the furnace chamber is kept at one atmosphere. The furnace chamber is heated through the first heating stage, the first insulation stage, the second heating stage and the second insulation stage. In the first heating stage, the first insulation stage and the second heating stage, a protective atmosphere and hydrogen are introduced, and the protective atmosphere flow rate is 100 sccm and the hydrogen flow rate is 40 sccm. Then methane and hydrogen are introduced in the second insulation stage, and the methane flow rate is 100 sccm and the hydrogen flow rate is 200 sccm. The obtained substance is a graphene / carbon nanotube composite material.

[0032] The size of the reduced graphene oxide is 15 μm and the specific surface area is 300 m 2 / g.

[0033] The additive is urea.

[0034] The catalyst is cupric chloride and its hydrated compound.

[0035] The second solvent is ethanol.

[0036] The first heating stage is heating from room temperature to 500°C at a heating rate of 10°C / min; the first insulation stage is insulation at 500°C for 1H; the second heating stage is heating from 500°C to 800°C at a heating rate of 5°C / min; the second insulation stage is insulation at 800°C for 15min.

[0037] The protective gas is nitrogen.

[0038] Step b: Prepare graphene@carbon nanotube composite materials modified by metal nanoparticle loading.

[0039] The graphene@carbon nanotubes and metal precursors are prepared by physical methods to obtain metal nanoparticle-loaded and modified graphene / carbon nanotube composite materials. The metal precursor includes a silver target.

[0040] The physical method is magnetron sputtering; the specific method is: placing graphene@carbon nanotubes on a sample stage, and setting two silver targets on opposite sides of the sample stage, respectively, with the relative directions being parallel to the surface of the sample platform; starting the magnetron sputtering instrument, evacuating the air pressure in the working chamber to below 4 Pa ​​by vacuuming, modulating the plasma current to 5 mA, and modulating the time for 2 minutes, so that the silver particles on the silver target are splashed onto the graphene powder, and obtaining a graphene / carbon nanotube composite material modified by metal nanoparticles.

[0041] The metal nano-modified graphene@carbon nanotube composite material is a silver nano-modified graphene@carbon nanotube composite material.

[0042] The diameter of the carbon nanotubes in the graphene@carbon nanotube composite material is 30nm and the length is 20μm; the particle size of the metal nanoparticles in the graphene@carbon nanotube composite material loaded with metal nanoparticles is 300nm. . The melting range of the glass powder is 600° C. The glass powder comprises the following components by mass percentage: 50% SiO2, 28% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0043] The resin is acrylic resin.

[0044] The first solvent is xylene.

[0045] The dispersant is selected from carboxylate dispersants.

[0046] The leveling agent is polyether-modified polysiloxane; and the defoaming agent is selected from mineral oil.

[0047] In this embodiment, the preparation method of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink comprises the following steps: S1 Accurately weigh each component.

[0048] S2: Add glass powder, resin, first solvent, dispersant and leveling agent in a dispersion tank in sequence, and stir at 1000 r / min for 20 min using a planetary mixer; then add weighed metal nanoparticle-loaded modified graphene@carbon nanotube composite material, and stir at 2000 r / min for 30 min; finally, add defoamer, and stir at 1500 r / min for 15 min; S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled below 15 μm, thereby obtaining a graphene@carbon nanotube composite conductive ink modified by metal nanoparticles.

[0049] In this embodiment, the curing temperature of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is staged sintering, with the first stage sintering temperature at 100°C and the time being 20 minutes; the second stage sintering temperature at 250°C and the time being 30 minutes; the third stage sintering temperature at 700°C and the time being 30 minutes; and then cooling to room temperature to complete the curing. Example 2

[0050] This embodiment provides a graphene conductive ink and a preparation method thereof, which are basically the same as Embodiment 1, and the main difference lies in the different types and contents of glass powder, resin and solvent.

[0051] The technical solution is as follows: A metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is composed of the following raw materials in parts by weight: 80 parts of metal nanoparticle-loaded modified graphene / carbon nanotube / composite material, 280 parts of glass powder, 220 parts of resin, 320 parts of a first solvent, 50 parts of a dispersant, 40 parts of a leveling agent, and 1 part of a defoaming agent.

[0052] The metal nanoparticle-modified graphene@carbon nanotube composite material method comprises the following steps: Step a: Preparation of graphene@carbon nanotube composite material The reduced graphene oxide, additive, catalyst and second solvent are mixed in a ratio of 1:15:5:100 and dried at 80°C for 2 hours to obtain a dry mixture. The dry mixture is placed in a tubular furnace, the air inlet valve and the air outlet valve of the furnace chamber are opened, and the furnace chamber is kept at one atmosphere. The furnace chamber is heated through the first heating stage, the first insulation stage, the second heating stage and the second insulation stage. In the first heating stage, the first insulation stage and the second heating stage, a protective atmosphere and hydrogen are introduced, and the protective atmosphere flow rate is 100 sccm and the hydrogen flow rate is 40 sccm. Then methane and hydrogen are introduced in the second insulation stage, and the methane flow rate is 100 sccm and the hydrogen flow rate is 200 sccm. The obtained substance is a graphene@carbon nanotube composite material.

[0053] The size of the reduced graphene oxide is 15 μm and the specific surface area is 300 m 2 / g.

[0054] The additive is urea.

[0055] The catalyst is cupric chloride and its hydrated compound.

[0056] The second solvent is ethanol.

[0057] The first heating stage is heating from room temperature to 500°C at a heating rate of 10°C / min; the first insulation stage is insulation at 500°C for 1H; the second heating stage is heating from 500°C to 800°C at a heating rate of 5°C / min; the second insulation stage is insulation at 800°C for 15min.

[0058] The protective gas is nitrogen.

[0059] Step b: Prepare graphene@carbon nanotube composite materials modified by metal nanoparticle loading.

[0060] The graphene@carbon nanotubes and metal precursors are prepared by physical methods to obtain metal nanoparticle-loaded and modified graphene / carbon nanotube composite materials. The metal precursor includes a silver target.

[0061] The physical method is magnetron sputtering; the specific method is: placing graphene@carbon nanotubes on a sample stage, and setting two silver targets on opposite sides of the sample stage, respectively, with the relative directions being parallel to the surface of the sample platform; starting the magnetron sputtering instrument, evacuating the air pressure in the working chamber to below 4 Pa ​​by vacuuming, modulating the plasma current to 5 mA, and modulating the time for 2 minutes, so that the silver particles on the silver target are splashed onto the graphene powder, and obtaining a graphene / carbon nanotube composite material modified by metal nanoparticles.

[0062] The metal nano-modified graphene@carbon nanotube composite material is a silver nano-modified graphene@carbon nanotube composite material.

[0063] The diameter of the carbon nanotubes in the graphene@carbon nanotube composite material is 30nm and the length is 20μm; the particle size of the metal nanoparticles in the graphene@carbon nanotube composite material loaded with metal nanoparticles is 300nm. . The melting range of the glass powder is 500° C. The glass powder comprises the following components by mass percentage: 45% SiO2, 33% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0064] The resin is epoxy resin.

[0065] The first solvent is ethylene glycol butyl ether.

[0066] The dispersant is selected from carboxylate dispersants.

[0067] The leveling agent is polyether modified polysiloxane; the defoaming agent is selected from mineral oil; In this embodiment, the preparation method of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink comprises the following steps: S1 Accurately weigh each component.

[0068] S2: Add glass powder, resin, first solvent, dispersant and leveling agent in a dispersion tank in sequence, and stir at 1000r / min for 20min using a planetary mixer; then add weighed metal nanoparticle-loaded modified graphene@carbon nanotube composite material, and stir at 2000r / min for 30min; finally, add defoamer, and stir at 1500r / min for 15min.

[0069] S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled below 15 μm, thereby obtaining a graphene@carbon nanotube composite conductive ink modified by metal nanoparticles.

[0070] In this embodiment, the curing temperature of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is staged sintering, with the first stage sintering temperature at 100°C and the time being 20 minutes; the second stage sintering temperature at 250°C and the time being 30 minutes; the third stage sintering temperature at 500°C and the time being 30 minutes; and then cooling to room temperature to complete the curing. Example 3

[0071] The present invention provides a graphene conductive ink and a preparation method thereof. Compared with Example 1, the main difference is that the preparation process of the graphene@carbon nanotube composite material is different.

[0072] In this embodiment, the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink has the following technical solution: A metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is composed of the following raw materials in parts by weight: 80 parts of metal nanoparticle-loaded modified graphene / carbon nanotube / composite material, 300 parts of glass powder, 200 parts of resin, 300 parts of a first solvent, 50 parts of a dispersant, 40 parts of a leveling agent, and 1 part of a defoaming agent.

[0073] The metal nanoparticle-modified graphene@carbon nanotube composite material method comprises the following steps: Step a: Preparation of graphene@carbon nanotube composite material The reduced graphene oxide, additive, catalyst and second solvent are mixed in a ratio of 1:15:5:100 and dried at 100°C for 1H to obtain a dry mixture. The dry mixture is placed in a tubular furnace, the air inlet valve and the air outlet valve of the furnace chamber are opened, and the furnace chamber is kept at one atmosphere. The furnace chamber is heated through the first heating stage, the first insulation stage, the second heating stage and the second insulation stage. In the first heating stage, the first insulation stage and the second heating stage, a protective atmosphere and hydrogen are introduced, and the protective atmosphere flow rate is 150sccm and the hydrogen flow rate is 80sccm. Then, methane and hydrogen are introduced in the second insulation stage, and the methane flow rate is 50sccm and the hydrogen flow rate is 150sccm. The obtained substance is a graphene@carbon nanotube composite material.

[0074] The size of the reduced graphene oxide is 15 μm and the specific surface area is 300 m 2 / g.

[0075] The additive is urea.

[0076] The catalyst is cupric chloride and its hydrated compound.

[0077] The second solvent is ethanol.

[0078] The first heating stage is heating from room temperature to 650°C at a heating rate of 8°C / min; the first insulation stage is insulation at 650°C for 1H; the second heating stage is heating from 650°C to 850°C at a heating rate of 8°C / min; the second insulation stage is insulation at 850°C for 15min.

[0079] The protective gas is nitrogen.

[0080] Step b: Prepare graphene@carbon nanotube composite materials modified by metal nanoparticle loading.

[0081] The graphene@carbon nanotube composite material modified by metal nanoparticles is prepared by physical method from graphene@carbon nanotube and metal precursor. The metal precursor includes a silver target.

[0082] The physical method is magnetron sputtering; the specific method is: placing graphene@carbon nanotubes on a sample stage, and setting two silver targets on opposite sides of the sample stage, respectively, with the relative directions being parallel to the surface of the sample platform; starting the magnetron sputtering instrument, evacuating the air pressure in the working chamber to below 4 Pa ​​by vacuuming, modulating the plasma current to 5 mA, and modulating the time for 2 minutes, so that the silver particles on the silver target are splashed onto the graphene powder, and obtaining a graphene / carbon nanotube composite material modified by metal nanoparticles.

[0083] The metal nanoparticle-loaded and modified graphene@carbon nanotube composite material is a silver nanoparticle-loaded and modified graphene@carbon nanotube composite material.

[0084] The diameter of the carbon nanotubes in the graphene@carbon nanotube composite material is 20 nm and the length is 30 μm; the particle size of the metal nanoparticles in the metal nanoparticle-loaded and modified graphene@carbon nanotube composite material is 300 nm.

[0085] The melting range of the glass powder is 600° C. The glass powder comprises the following components by mass percentage: 50% SiO2, 28% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0086] The resin is acrylic resin.

[0087] The first solvent is xylene.

[0088] The dispersant is selected from carboxylate dispersants.

[0089] The leveling agent is polyether modified polysiloxane; the defoaming agent is selected from mineral oil; In this embodiment, the preparation method of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink comprises the following steps: S1 Accurately weigh each component.

[0090] S2: Add glass powder, resin, first solvent, dispersant and leveling agent in a dispersion tank in sequence, and stir at 1000 r / min for 20 min using a planetary mixer; then add weighed metal nanoparticle-loaded modified graphene@carbon nanotube composite material, and stir at 2000 r / min for 30 min; finally, add defoamer, and stir at 1500 r / min for 15 min; S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled below 15 μm, thereby obtaining a graphene@carbon nanotube composite conductive ink modified by metal nanoparticles.

[0091] In this embodiment, the curing temperature of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is staged sintering, with the first stage sintering temperature at 100°C and the time being 20 minutes; the second stage sintering temperature at 250°C and the time being 30 minutes; the third stage sintering temperature at 700°C and the time being 30 minutes; and then cooling to room temperature to complete the curing. Example 4

[0092] The present invention provides a graphene conductive ink and a preparation method thereof. Compared with Example 3, the raw materials used in the graphene@carbon nanotube composite material modified by main metal nanoparticle loading are different and the preparation process is different.

[0093] In this embodiment, the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink has the following technical solution: A metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink, comprising the following raw materials in parts by weight: 80 parts of metal nanoparticle-loaded modified graphene / carbon nanotube / composite material, 300 parts of glass powder, 200 parts of resin, 300 parts of a first solvent, 50 parts of a dispersant, 40 parts of a leveling agent, and 1 part of a defoaming agent; The metal nanoparticle-modified graphene@carbon nanotube composite material method comprises the following steps: Step a: Preparation of graphene@carbon nanotube composite material The reduced graphene oxide, additive, catalyst and second solvent are mixed in a ratio of 1:10:10:80 and dried at 100°C for 1H to obtain a dry mixture. The dry mixture is placed in a tubular furnace, the air inlet valve and the air outlet valve of the furnace chamber are opened, and the furnace chamber is kept at one atmosphere. The furnace chamber is heated through the first heating stage, the first insulation stage, the second heating stage and the second insulation stage. In the first heating stage, the first insulation stage and the second heating stage, a protective atmosphere and hydrogen are introduced, and the protective atmosphere flow rate is 150sccm and the hydrogen flow rate is 80sccm. Then, methane and hydrogen are introduced in the second insulation stage, and the methane flow rate is 50sccm and the hydrogen flow rate is 150sccm. The obtained substance is a graphene / carbon nanotube composite material.

[0094] The size of the reduced graphene oxide is 15 μm and the specific surface area is 300 m 2 / g.

[0095] The additive is melamine.

[0096] The catalyst is copper sulfate and its hydrated compound.

[0097] The second solvent is water.

[0098] The first heating stage is heating from room temperature to 650°C at a heating rate of 8°C / min; the first insulation stage is insulation at 650°C for 1H; the second heating stage is heating from 650°C to 850°C at a heating rate of 8°C / min; the second insulation stage is insulation at 850°C for 15min.

[0099] The protective gas is nitrogen.

[0100] Step b: Prepare graphene@carbon nanotube composite materials modified by metal nanoparticle loading.

[0101] The graphene@carbon nanotube composite material modified by metal nanoparticles is prepared by chemical method. The metal precursor includes a silver target.

[0102] The chemical method is magnetron sputtering; the specific method is: placing graphene@carbon nanotubes on a sample stage, and setting two silver targets on opposite sides of the sample stage, respectively, with the relative directions being parallel to the surface of the sample platform; starting the magnetron sputtering instrument, evacuating the air pressure in the working chamber to below 4 Pa ​​by vacuuming, modulating the plasma current to 5 mA, and modulating the time for 2 minutes, so that the silver particles on the silver target are splashed onto the graphene powder, and obtaining a graphene / carbon nanotube composite material modified by metal nanoparticles.

[0103] The metal nanoparticle-loaded and modified graphene@carbon nanotube composite material is a gold nanoparticle-modified graphene@carbon nanotube composite material.

[0104] The diameter of the carbon nanotubes in the graphene@carbon nanotube composite material is 40 nm and the length is 10 μm; the particle size of the metal nanoparticles in the metal nanoparticle-loaded and modified graphene@carbon nanotube composite material is 500 nm.

[0105] The melting range of the glass powder is 600° C. The glass powder comprises the following components by mass percentage: 50% SiO2, 28% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0106] The resin is acrylic resin.

[0107] The first solvent is xylene.

[0108] The dispersant is selected from carboxylate dispersants.

[0109] The leveling agent is polyether modified polysiloxane; the defoaming agent is selected from mineral oil; In this embodiment, the preparation method of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink comprises the following steps: S1 Accurately weigh each component.

[0110] S2: Add glass powder, resin, first solvent, dispersant and leveling agent in a dispersion tank in sequence, and stir at 1000 r / min for 20 min using a planetary mixer; then add weighed metal nanoparticle-loaded modified graphene@carbon nanotube composite material, and stir at 2000 r / min for 30 min; finally, add defoamer, and stir at 1500 r / min for 15 min; S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled below 15 μm, thereby obtaining a graphene@carbon nanotube composite conductive ink modified by metal nanoparticles.

[0111] In this embodiment, the curing temperature of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is staged sintering, with the first stage sintering temperature being 100°C and the time being 20 min; the second stage sintering temperature being 250°C and the time being 30 min; the third stage sintering temperature being 700°C and the time being 30 min; and then cooling to room temperature to complete the curing.

[0112] Comparative Example 1 This comparative example provides a metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink and a preparation method thereof, which is basically the same as Example 1, with the main difference being that the metal nanoparticle-loaded modified graphene@carbon nanotube composite material in Example 1 is replaced with metallic silver powder.

[0113] The technical solution is as follows: A conductive ink is composed of the following raw materials in parts by weight: 80 parts of metallic silver powder, 300 parts of glass powder, 200 parts of resin, 300 parts of solvent, 50 parts of dispersant, 40 parts of leveling agent, and 1 part of defoaming agent; The melting range of the glass powder is 600° C. The glass powder comprises the following components by mass percentage: 50% SiO2, 28% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0114] The resin is acrylic resin.

[0115] The solvent is xylene.

[0116] The dispersant is selected from carboxylate dispersants.

[0117] The leveling agent is polyether modified polysiloxane; the defoaming agent is selected from mineral oil; The preparation method of the conductive ink comprises the following steps: S1 Accurately weigh each component.

[0118] S2: Add glass powder, resin, solvent, dispersant and leveling agent to the dispersion tank in sequence, and stir at 1000r / min for 20min using a planetary mixer; then add weighed metal silver powder and stir at 2000r / min for 30min; finally add defoamer and stir at 1500r / min for 15min; S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled to be below 15 μm, thereby obtaining a conductive ink.

[0119] The curing temperature of the conductive ink is staged sintering, the first stage sintering temperature is 100°C, the time is 20 minutes; the second stage sintering temperature is 250°C, the time is 30 minutes; the third stage sintering temperature is 700°C, the time is 30 minutes; then it is cooled to room temperature, and the curing is completed.

[0120] Comparative Example 2 This comparative example provides a conductive ink and a preparation method thereof, which are basically the same as Example 1, except that the metal nanoparticle-loaded modified graphene@carbon nanotube composite material in Example 1 is replaced with graphene.

[0121] The technical solution is as follows: A conductive ink, comprising the following raw materials in parts by weight: 80 parts of graphene, 300 parts of glass powder, 200 parts of resin, 300 parts of solvent, 50 parts of dispersant, 40 parts of leveling agent, and 1 part of defoaming agent; The melting range of the glass powder is 600° C. The glass powder comprises the following components by mass percentage: 50% SiO2, 28% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0122] The resin is acrylic resin.

[0123] The solvent is xylene.

[0124] The dispersant is selected from carboxylate dispersants.

[0125] The leveling agent is polyether modified polysiloxane; the defoaming agent is selected from mineral oil; The preparation method of the conductive ink comprises the following steps: S1 Accurately weigh each component.

[0126] S2: Add glass powder, resin, solvent, dispersant and leveling agent to the dispersion tank in sequence, and stir at 1000r / min for 20min using a planetary mixer; then add weighed graphene and stir at 2000r / min for 30min; finally add defoamer and stir at 1500r / min for 15min; S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled to be below 15 μm, thereby obtaining a conductive ink.

[0127] The curing temperature of the conductive ink is staged sintering, the first stage sintering temperature is 100°C, the time is 20 minutes; the second stage sintering temperature is 250°C, the time is 30 minutes; the third stage sintering temperature is 700°C, the time is 30 minutes; then it is cooled to room temperature, and the curing is completed.

[0128] Comparative Example 3 This comparative example provides a conductive ink and a preparation method thereof, which are basically the same as Example 1, except that the metal nanoparticle-loaded modified graphene@carbon nanotube composite material in Example 1 is replaced with carbon nanotubes.

[0129] The technical solution is as follows: A conductive ink is composed of the following raw materials in parts by weight: 80 parts of carbon nanotubes, 300 parts of glass powder, 200 parts of resin, 300 parts of solvent, 50 parts of dispersant, 40 parts of leveling agent, and 1 part of defoaming agent; The melting range of the glass powder is 600° C. The glass powder comprises the following components by mass percentage: 50% SiO2, 28% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0130] The resin is acrylic resin.

[0131] The solvent is xylene.

[0132] The dispersant is selected from carboxylate dispersants.

[0133] The leveling agent is polyether modified polysiloxane; the defoaming agent is selected from mineral oil; The preparation method of the conductive ink comprises the following steps: S1 Accurately weigh each component.

[0134] S2: Add glass powder, resin, solvent, dispersant and leveling agent to the dispersion tank in sequence, and stir at 1000r / min for 20min using a planetary mixer; then add weighed carbon nanotubes and stir at 2000r / min for 30min; finally add defoamer and stir at 1500r / min for 15min; S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled to be below 15 μm, thereby obtaining a conductive ink.

[0135] The curing temperature of the conductive ink is staged sintering, the first stage sintering temperature is 100°C, the time is 20 minutes; the second stage sintering temperature is 250°C, the time is 30 minutes; the third stage sintering temperature is 700°C, the time is 30 minutes; then it is cooled to room temperature, and the curing is completed.

[0136] Comparative Example 4 This comparative example provides a conductive ink and a preparation method thereof, which are basically the same as Example 1, except that the metal nanoparticle-loaded modified graphene@carbon nanotube composite material in Example 1 is replaced with a mixture of metallic silver powder, graphene and carbon nanotubes.

[0137] The technical solution is as follows: A conductive ink is composed of the following raw materials in parts by weight: 80 parts of a mixture of metallic silver powder, graphene and carbon nanotubes, 300 parts of glass powder, 200 parts of resin, 300 parts of solvent, 50 parts of dispersant, 40 parts of leveling agent and 1 part of defoaming agent.

[0138] The melting range of the glass powder is 600° C. The glass powder comprises the following components by mass percentage: 50% SiO2, 28% Al2O3, 15% ZnO, 4% MgO, and 3% SnO2; the particle size of the glass powder is 15 μm.

[0139] The resin is acrylic resin.

[0140] The solvent is xylene.

[0141] The dispersant is selected from carboxylate dispersants.

[0142] The leveling agent is polyether modified polysiloxane; the defoaming agent is selected from mineral oil; The preparation method of the conductive ink comprises the following steps: S1 Accurately weigh each component.

[0143] S2: Add glass powder, resin, solvent, dispersant and leveling agent in a dispersion tank in sequence, and stir at 1000r / min for 20min using a planetary mixer; then add a weighed mixture of metal silver powder, graphene and carbon nanotubes, and stir at 2000r / min for 30min; finally, add a defoamer, and stir at 1500r / min for 15min; S3 The mixed slurry is ground using a three-roll grinder for 5 times, and the slurry fineness is controlled to be below 15 μm, thereby obtaining a conductive ink.

[0144] The curing temperature of the conductive ink is staged sintering, the first stage sintering temperature is 100°C, the time is 20 minutes; the second stage sintering temperature is 250°C, the time is 30 minutes; the third stage sintering temperature is 700°C, the time is 30 minutes; then it is cooled to room temperature, and the curing is completed.

[0145] The viscosity of the conductive inks of the above examples and comparative examples was tested according to the standard of JIS Z8803:2011.

[0146] The conductive inks of the above-mentioned embodiment and comparative example were cured to form a coating on the same substrate. The sheet resistance was tested under the condition of a coating thickness of 25 μm using a four-probe method. The test indicators were as follows: Table 1

[0147] As can be seen from Table 1, Comparative Examples 2 to 4 use graphene, carbon nanotubes or a mixture of graphene and carbon nanotubes as conductive fillers, which are difficult to disperse evenly in the system, and the system viscosity is high, the square resistance is also high, and the conductivity is poor. Comparative Example 1 uses metal silver powder as a conductive filler, which is only a zero-dimensional filler, and the conductive performance of the ink is not greatly improved, and the system square resistance is also high. The use of graphene@carbon nanotube composite materials modified by metal nanoparticles as conductive fillers can solve the problem of carbon nanotubes and graphene being easily agglomerated in the system, and can also construct a three-dimensional conductive network to improve conductivity. The prepared graphene conductive ink has moderate viscosity and low square resistance.

[0148] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0149] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink, characterized in that: The invention is composed of the following raw materials in parts by weight: 30-300 parts of a graphene@carbon nanotube composite material modified by loading metal nanoparticles, 100-400 parts of glass powder, 100-300 parts of a resin, 200-400 parts of a first solvent, 20-80 parts of a dispersant, 10-60 parts of a leveling agent, and 0.2-3 parts of a defoaming agent.

2. The metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink according to claim 1, characterized in that: The preparation method of the metal nanoparticle-loaded modified graphene@carbon nanotube composite material comprises the following steps: Step a: preparing a graphene@carbon nanotube composite material; The reduced graphene oxide, the additive, the catalyst and the second solvent are uniformly mixed in a weight ratio of 1:(1-20):(0.5-25):(50-150), and dried at 40-100° C. for 0.5-3 hours to obtain a dry mixture; the dry mixture is placed in a tubular furnace, the air inlet valve and the air outlet valve of the furnace chamber are opened, and the furnace chamber is kept at one atmosphere, and the furnace chamber is heated through a first heating stage, a first insulation stage, a second heating stage and a second insulation stage; a protective atmosphere and hydrogen are introduced in the first heating stage, the first insulation stage and the second heating stage, the protective atmosphere flow rate is 50-200 sccm, and the hydrogen flow rate is 10-100 sccm; then methane and hydrogen are introduced in the second insulation stage, the methane flow rate is 5-100 sccm, and the hydrogen flow rate is 10-300 sccm; the obtained substance is a graphene@carbon nanotube composite material; The size of the reduced graphene oxide is 10-50 μm, and the specific surface area is 100-400 m 2 / g; the additive is at least one of cyanamide, dicyandiamide, melamine, urea and thiourea; The catalyst is at least one of copper chloride and its hydrated compounds, copper sulfate and its hydrated compounds, copper nitrate and its hydrated compounds; The second solvent is at least one of ethanol and deionized water; The first heating stage is heating from room temperature to 450-650°C, with a heating rate of 5-10°C / min; the first heat preservation stage is heat preservation at 450-650°C for 15min-2H; the second heating stage is heating from 450-650°C to 750-900°C, with a heating rate of 5-10°C / min; the second heat preservation stage is heat preservation at 750-900°C for 15min-1H; The protective gas is at least one of nitrogen and argon; Step b: preparing a graphene@carbon nanotube composite material modified by metal nanoparticle loading; The graphene@carbon nanotube and metal precursor are prepared by physical or chemical methods to obtain a graphene@carbon nanotube composite material loaded with metal nanoparticles; Wherein, the metal precursor is at least one of a salt containing metal ions, a metal powder and a metal target, and further includes at least one of a gold salt, a silver salt, a copper salt, a gold powder, a silver powder, a copper powder, a gold target, a silver target and a copper target; The physical or chemical method comprises any one of magnetron sputtering, physical and chemical vapor deposition, electroplating, and chemical plating; The metal nanoparticle-loaded modified graphene@carbon nanotube composite material includes any one of a gold nanoparticle-loaded modified graphene@carbon nanotube composite material, a silver nanoparticle-loaded modified graphene@carbon nanotube composite material, and a copper nanoparticle-loaded modified graphene@carbon nanotube composite material.

3. The metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink according to claim 2, characterized in that: The diameter of the carbon nanotubes in the graphene@carbon nanotube composite material is 1-50 nm and the length is 10-30 μm; the particle size of the metal nanoparticles in the metal nanoparticle-loaded and modified graphene@carbon nanotube composite material is 1-500 nm.

4. The metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink according to claim 1, characterized in that: The melting range of the glass powder is 600-800° C. The glass powder comprises the following components by mass percentage: 30-55% SiO2, 10-35% Al2O3, 5-15% ZnO, 3-5% MgO, and 1-5% SnO2; the particle size of the glass powder is 1-20 μm.

5. The metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink according to claim 1, characterized in that: The resin is one or more of acrylic resin, polyester resin and epoxy resin.

6. The metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink according to claim 1, characterized in that: The first solvent is at least one of xylene, NN dimethylformamide, n-butanol, ethylene glycol butyl ether, and diethylene glycol butyl ether acetate.

7. The metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink according to claim 1, characterized in that: The dispersant is selected from at least one of a carboxylate dispersant, an aliphatic amide dispersant and an ester dispersant.

8. The metal nanoparticle-loaded and modified graphene@carbon nanotube composite conductive ink according to claim 1, characterized in that: The leveling agent is at least one of polyether and polyether-modified polysiloxane; the defoaming agent is at least one of mineral oil and silicone.

9. A method for preparing a conductive ink of graphene@carbon nanotube composite material modified by metal nanoparticle loading, characterized in that: The following steps are involved: S1 Accurately weigh each component; S2: Add glass powder, resin, solvent, dispersant and leveling agent in a dispersion tank in sequence, and stir at 500-2000 r / min for 5-60 min using a planetary mixer; then add the weighed graphene@carbon nanotube composite material loaded with metal nanoparticles and stir at 800-3000 r / min for 20-60 min; finally, add the defoamer and stir at 500-2000 r / min for 5-30 min; S3 The mixed slurry is ground using a three-roll grinder for 3 to 5 times, and the slurry fineness is controlled below 15 μm, thereby obtaining a graphene@carbon nanotube composite conductive ink modified by metal nanoparticles.

10. A method for curing a metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink, characterized in that: The metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is prepared by the preparation method described in claim 9, and the curing temperature of the metal nanoparticle-loaded modified graphene@carbon nanotube composite conductive ink is segmented sintering, the first segment sintering temperature is 80~150℃, and the time is 10~30min; the second segment sintering temperature is 200~350℃, and the time is 10~30min; the third segment sintering temperature is 500~800℃, and the time is 10min~60min; and then it is cooled to room temperature, and the curing is completed.

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