阅读说明：本技术 一种水性石墨烯基导电油墨及其制备方法 (Water-based graphene-based conductive ink and preparation method thereof ) 是由 张羽 吴欢 张国敏 刘君 于 2018-07-03 设计创作，主要内容包括：本发明涉及一种水性石墨烯基导电油墨,包括：1％～15％水性树脂,30％～90％石墨烯基复合浆料,0.5％～3％第一助剂,5％-10％溶剂；其中,所述石墨烯基复合浆料包括石墨烯微片、碳纳米管、纳米级超导电炭黑、稀释剂及第二助剂；所述石墨烯、碳纳米管及纳米级超导电炭黑的质量比为(3～10):(0.5～5):(0.1～4)。所述水性石墨烯基导电油墨性能稳定,环保高效,电阻值极低,可替代市面现有溶剂型油墨产品。本发明还涉及一种水性石墨烯基导电油墨的制备方法。(The invention relates to a water-based graphene-based conductive ink, which comprises: 1-15% of water-based resin, 30-90% of graphene-based composite slurry, 0.5-3% of first auxiliary agent and 5-10% of solvent; the graphene-based composite slurry comprises graphene micro-sheets, carbon nano-tubes, nano-scale superconducting carbon black, a diluent and a second auxiliary agent; the mass ratio of the graphene to the carbon nano tube to the nano-grade superconducting carbon black is (3-10): (0.5-5): 0.1-4). The aqueous graphene-based conductive ink is stable in performance, environment-friendly, efficient, extremely low in resistance value and capable of replacing the existing solvent-based ink products in the market. The invention also relates to a preparation method of the water-based graphene-based conductive ink.)

1. The aqueous graphene-based conductive ink is characterized by comprising the following components in parts by mass: 1-15% of water-based resin, 30-90% of graphene-based composite slurry, 0.5-3% of a first auxiliary agent and 5-10% of a solvent, wherein the graphene-based composite slurry comprises graphene micro-sheets, carbon nano-tubes, nanoscale superconducting carbon black, a diluent and a second auxiliary agent; the mass ratio of the graphene nanoplatelets, the carbon nanotubes and the nano-scale superconducting carbon black is (3-10): (0.5-5): 0.1-4).

2. The aqueous graphene-based conductive ink according to claim 1, wherein the aqueous resin is at least one of an aqueous epoxy resin, an aqueous polyurethane resin and an aqueous amino resin, the aqueous resin accounts for 1-10% of the mass of the aqueous graphene-based conductive ink, and the graphene-based composite paste accounts for 50-85% of the mass of the aqueous graphene-based conductive ink.

3. The aqueous graphene-based conductive ink according to claim 1, wherein the number of graphene nanoplatelets is 5-7, and the thickness of the graphene nanoplatelets is less than 2.5 nm.

4. The aqueous graphene-based conductive ink according to claim 1, wherein the nanoscale superconducting carbon black is at least one of ketjen black EC-600JD and conductive carbon black BP-2000.

5. The aqueous graphene-based conductive ink as claimed in claim 1, wherein the mass ratio of the graphene nanoplatelets, the carbon nanotubes and the nano-scale superconducting carbon black in the graphene-based composite slurry is (3-7): (1-5): 0.5-2.

6. The aqueous graphene-based conductive ink according to claim 1, wherein the graphene nanoplatelets account for 0.5-10% by mass of the graphene-based composite paste, the carbon nanotubes account for 0.1-5% by mass of the graphene-based composite paste, the nano-scale superconducting carbon black accounts for 0.5-5% by mass of the graphene-based composite paste, the diluent accounts for 50-95% by mass of the graphene-based composite paste, and the second additive accounts for 0.1-3% by mass of the graphene-based composite paste.

7. The aqueous graphene-based conductive ink according to claim 1, wherein the diluent is at least one of N-methylpyrrolidone, dipropylene glycol, N-dimethylethanolamine, propylene glycol butyl ether, and water, and the solvent is at least one of N-methylpyrrolidone, dipropylene glycol, N-dimethylethanolamine, propylene glycol butyl ether, ethanol, and water.

8. The aqueous graphene-based conductive ink according to claim 1, wherein the first auxiliary agent and the second auxiliary agent are the same and each of the first auxiliary agent and the second auxiliary agent comprises at least one of a dispersant, a wetting agent, a defoaming agent and an anti-flowing agent.

9. The aqueous graphene-based conductive ink according to claim 8, wherein the dispersant is any one of a sodium polycarboxylate, a potassium polyacrylate, and a sodium polyacrylate; the wetting agent is at least one of fatty acid ester sulfate, a polyoxyethylene modifier, a polyether modified polysiloxane polymer and alkyl polyoxyethylene ether; the defoaming agent is any one of waterborne polyether modified organic silicon and high-carbon alcohol non-silicon; the anti-flowing agent is at least one of modified urea solution, organic bentonite, fumed silica and polyamide wax.

10. The method for preparing the aqueous graphene-based conductive ink according to any one of claims 1 to 9, comprising the steps of:

1) mixing the graphene nanoplatelets, the nanoscale superconducting carbon black, the diluent and the second auxiliary agent, stirring at a stirring speed of 200-500 rpm for 5-10 minutes, and dispersing at a rotating speed of 3000-4000 rpm for 30-40 minutes after uniform stirring to obtain a premixed solution; wherein the diluent comprises at least one of N-methyl pyrrolidone, dipropylene glycol, N-dimethylethanolamine, propylene glycol butyl ether and water;

2) mixing the premixed solution with the carbon nano tube, and dispersing for 10-20 minutes at the rotating speed of 300-500 rpm to obtain graphene-based composite slurry;

3) mixing the graphene-based composite slurry with aqueous resin, a solvent and a first auxiliary agent, and dispersing for 10-20 minutes at a rotating speed of 300-500 rpm to obtain the aqueous graphene-based conductive ink, wherein the solvent comprises at least one of ethanol, N-dimethylethanolamine, propylene glycol butyl ether and water.

Technical Field

The invention relates to ink, in particular to water-based graphene-based conductive ink and a preparation method thereof.

Background

With the rapid development of science and technology, conductive ink is also continuously developed. The conductive ink is made of conductive materials (gold, silver, copper and carbon), has a certain conductive property, and can be used for printing conductive points or conductive circuits. Gold-based conductive inks, silver-based conductive inks, copper-based conductive inks, carbon-based conductive inks, and the like have been put into practical use and used for printed circuits, electrodes, plating primers, keyboard contacts, printed circuits, and the like. In recent years, the infrared heating film has become more and more widely applied to industries such as mobile phones, toys, membrane switches, solar cells, far infrared heating films, RFID and the like. The gold and silver conductive ink has the best performance, but is expensive; the copper-based conductive ink has good conductivity and lower price than gold and silver, but is easy to oxidize in the air, and has high requirement on the preparation process and poor stability of devices. The carbon-based conductive ink is low in price and good in chemical stability, but the current conductive ink based on conductive carbon black and conductive graphite is poor in conductivity and can only be used for products with low requirements on conductivity.

Graphene is the thinnest material, and is also the toughest material, with a fracture strength 200 times higher than the best steel. Meanwhile, the carbon nano-material has good elasticity, the stretching amplitude can reach 20% of the size of the carbon nano-material, and the carbon nano-material is used as a new member in the carbon nano-material, is applied to the preparation of novel conductive ink and has wide prospect.

Disclosure of Invention

The invention provides the water-based graphene-based conductive ink which is simple in process and suitable for industrialization and the preparation method thereof.

An aqueous graphene-based conductive ink comprising: 1 to 15 weight percent of water-based resin; 30-90 wt% of graphene composite slurry, 0.5-3 wt% of first auxiliary agent and 5-10% of solvent, wherein the graphene composite slurry comprises graphene micro-sheets, carbon nano-tubes, nano-scale superconducting carbon black, a diluent and a second auxiliary agent, and the mass ratio of the graphene micro-sheets, the carbon nano-tubes and the nano-scale superconducting carbon black is (3-10): (0.5-5): 0.1-4.

The aqueous graphene-based conductive ink has the following advantages: firstly, a three-dimensional conductive network can be formed in the aqueous graphene-based conductive ink by limiting the specific proportion of each component, particularly the mass ratio of the graphene nanoplatelets, the carbon nanotubes and the nano-scale superconducting carbon black to the carbon black, and because the three components have good conductivity and are respectively represented in three dimensions on a microscopic scale. Due to the existence of the conductive network, the aqueous graphene-based conductive ink has excellent conductive performance, and the sheet resistance of the aqueous graphene-based conductive ink is less than 10 omega. Secondly, the graphene nanoplatelets are used in the aqueous graphene-based conductive ink, and are the toughest materials, so that the breaking strength is 200 times higher than that of the best steel, and the aqueous graphene-based conductive ink has good elasticity, and the stretching amplitude can reach 20% of the self size, so that the mechanical property of the conductive ink can be greatly improved, the flexibility of the conductive ink is enhanced, the bending resistance is good, and the adhesive force between the conductive ink and a substrate is good.

The invention provides a preparation method of water-based graphene-based conductive ink, which comprises the following steps:

1) mixing the graphene nanoplatelets, the nanoscale superconducting carbon black, the diluent and the second auxiliary agent, stirring at a stirring speed of 200-500 rpm for about 5-10 minutes, and dispersing at a rotating speed of 3000-4000 rpm for 30-40 minutes after uniform stirring to obtain a premixed solution; wherein the diluent comprises at least one of N-methyl pyrrolidone, dipropylene glycol, N-dimethylethanolamine, propylene glycol butyl ether and water;

2) mixing the premixed solution with the carbon nano tube, and dispersing for 10-20 minutes at the rotating speed of 300-500 rpm to obtain graphene-based composite slurry;

3) mixing the graphene-based composite slurry with aqueous resin, a solvent and a first auxiliary agent, and dispersing for 10-20 minutes at a rotating speed of 300-500 rpm to obtain the aqueous graphene-based conductive ink, wherein the solvent comprises at least one of ethanol, N-dimethylethanolamine, propylene glycol butyl ether and water.

In the preparation method, the process is simple, and the water-based graphene-based conductive ink with uniform dispersion and stable performance can be obtained.

Detailed Description

The aqueous graphene-based conductive ink and the preparation method thereof provided by the invention are further described below.

The invention provides water-based graphene-based conductive ink. The aqueous graphene-based conductive ink comprises the following components in parts by mass: 1-15% of water-based resin, 30-90% of graphene composite slurry, 0.5-3% of first auxiliary agent and 5-10% of solvent.

Preferably, the graphene-based composite slurry accounts for 50-85% of the mass fraction of the aqueous graphene-based conductive ink.

The graphene composite slurry comprises graphene micro-sheets, carbon nano-tubes, nano-scale superconducting carbon black, a diluent and a second auxiliary agent. The mass ratio of graphene in the graphene slurry to carbon nanotubes in the carbon nanotube slurry to conductive carbon black is (3-10): 0.5-5): 0.1-4. Preferably, in order to enable the graphene nanoplatelets, the carbon nanotubes and the nano-scale superconducting carbon black to form a better conductive effect, the mass ratio of the graphene nanoplatelets, the carbon nanotubes and the conductive carbon black can be (3-7): 1-5): 0.5-2.

Specifically, the graphene nanoplatelets account for 0.5-10% of the graphene-based composite slurry by mass, the carbon nanotubes account for 0.1-5% of the graphene-based composite slurry by mass, the nanoscale superconducting carbon black accounts for 0.5-5% of the graphene-based composite slurry by mass, the diluent accounts for 50-95% of the graphene-based composite slurry by mass, and the second additive accounts for 0.1-3% of the graphene-based composite slurry by mass.

Preferably, in order to enable the finally obtained water-based graphene-based conductive ink to have better viscosity and the graphene nanoplatelets, the carbon nanotubes and the nano-scale superconducting carbon black to have excellent dispersion performance, the mass fraction of the graphene nanoplatelets in the graphene-based composite slurry is 1% -5%, the mass fraction of the carbon nanotubes in the graphene-based composite slurry is 0.5% -2%, the mass fraction of the conductive carbon black in the graphene-based composite slurry is 0.5% -2%, the mass fraction of the diluent in the graphene-based composite slurry is 80% -90%, and the mass fraction of the second additive in the graphene-based composite slurry is 0.1% -0.5%.

Preferably, the graphene nanoplatelets are available from Ningbo Moxie technologies, Inc. under model number EPOG-80. The carbon nanotubes were purchased from tiannai materials science and technology ltd, model number Flotube 9210.

The water-based resin is at least one of water-based epoxy resin, water-based polyurethane resin and water-based amino resin. The mass fraction of the aqueous resin in the aqueous graphene-based conductive ink is preferably 1-10%.

The diluent is at least one of N-methyl pyrrolidone, dipropylene glycol, N-dimethylethanolamine, propylene glycol butyl ether and water. The solvent is at least one of N-methyl pyrrolidone, dipropylene glycol, N-dimethylethanolamine, propylene glycol butyl ether, ethanol and water. Preferably, the diluent is N-methyl pyrrolidone, N-dimethylethanolamine, propylene glycol butyl ether and water; the solvent is ethanol.

The first auxiliary agent and the second auxiliary agent are the same and respectively comprise a dispersing agent, a wetting agent, a defoaming agent and an anti-flowing agent.

The dispersing agent is any one of sodium polycarboxylate, potassium polyacrylate and sodium polyacrylate; the wetting agent is at least one of fatty acid ester sulfate, a polyoxyethylene modifier, a polyether modified polysiloxane polymer and alkyl polyoxyethylene ether; the defoaming agent is any one of waterborne polyether modified organic silicon and high-carbon alcohol non-silicon; the anti-flowing agent is at least one of modified urea solution, organic bentonite, fumed silica and polyamide wax. Preferably, the dispersing agent is a sodium polycarboxylate, the wetting agent is a polyether modified polysiloxane polymer and alkyl polyoxyethylene ether, the defoaming agent is a water-based polyether modified silicone, and the anti-rheological agent is a modified urea solution.

The invention provides a preparation method of water-based graphene-based conductive ink, which comprises the following steps:

s1, mixing the graphene nanoplatelets, the nano-scale superconducting carbon black, the diluent and the second auxiliary agent, stirring for 5-10 minutes at a stirring speed of 200-500 rpm, and dispersing for 30-40 minutes at a rotating speed of 3000-4000 rpm after uniform stirring to obtain a premixed solution; wherein the diluent comprises at least one of N-methyl pyrrolidone, dipropylene glycol, N-dimethylethanolamine, propylene glycol butyl ether and water;

s2, mixing the premixed solution with the carbon nano tube, and dispersing for 10-20 minutes at the rotating speed of 300-500 rpm to obtain graphene-based composite slurry;

and S3, mixing the graphene-based composite slurry with aqueous resin, a solvent and a first auxiliary agent, and dispersing for 10-20 minutes at a rotating speed of 300-500 rpm to obtain the aqueous graphene-based conductive ink, wherein the solvent comprises at least one of ethanol, N-dimethylethanolamine, propylene glycol butyl ether and water.

In step S1, a specific preferred mixing method is as follows: and mixing the graphene nanoplatelets, the diluent and the second auxiliary agent, dispersing for 5 minutes at the rotating speed of 500 rpm, then adding the nano-scale superconducting conductive carbon black, uniformly stirring, and dispersing for 40 minutes at the rotating speed of 3500 rpm to obtain the premix.

In step S2, the specific steps are preferably as follows: the premix was mixed with carbon nanotubes and dispersed at 500 rpm for 15 minutes.

In step S3, a specific preferred mixing method is to mix the graphene-based composite paste with the aqueous resin, the solvent and the first auxiliary agent, and disperse the mixture for 20 minutes at a rotation speed of 400 rpm to obtain the aqueous graphene-based conductive ink.

The aqueous graphene-based conductive ink and the preparation method thereof according to the present invention will be further described with reference to specific examples.