阅读说明：本技术 一种石墨烯复合导电油墨及其制备方法 (Graphene composite conductive ink and preparation method thereof ) 是由 常海欣 李刚辉 郭辉 于 2019-12-18 设计创作，主要内容包括：本发明公开了一种石墨烯复合导电油墨及其制备方法,涉及一种导电油墨。本发明所述的石墨烯复合导电油墨,以重量份计,包括树脂10-20份、石墨烯纳米银粉10-20份、碳纳米管5-10份、有机溶剂10-20份、分散剂1-3份、消泡剂1-3份、抗氧剂1-3份,其中：所述石墨烯纳米银粉利用光致还原法制得。本发明制备的石墨烯复合导电油墨作为导电剂时,导电纳米银颗粒很好地负载在石墨烯片上,结构稳定,不易脱落,同时还充当导电网络的节点,增加导电网络通路的数量,能辅助完善石墨烯的导电网络,增加单位体积的导电粒子的数量,导电性高、电阻率低。另外,本发明制备方法得到的石墨烯复合导电油墨附着力强且硬度高。(The invention discloses graphene composite conductive ink and a preparation method thereof, and relates to conductive ink. The graphene composite conductive ink comprises, by weight, 10-20 parts of resin, 10-20 parts of graphene nano silver powder, 5-10 parts of carbon nano tubes, 10-20 parts of an organic solvent, 1-3 parts of a dispersing agent, 1-3 parts of a defoaming agent and 1-3 parts of an antioxidant, wherein: the graphene nano silver powder is prepared by a photo-reduction method. When the graphene composite conductive ink prepared by the invention is used as a conductive agent, the conductive nano silver particles are well loaded on a graphene sheet, the structure is stable, the conductive nano silver particles are not easy to fall off, and meanwhile, the conductive nano silver particles are also used as nodes of a conductive network, so that the number of conductive network paths is increased, the conductive network of graphene can be improved in an auxiliary manner, the number of conductive particles in unit volume is increased, and the graphene composite conductive ink is high in conductivity and low in resistivity. In addition, the graphene composite conductive ink prepared by the preparation method disclosed by the invention is strong in adhesive force and high in hardness.)

1. The graphene composite conductive ink is characterized in that: the graphene nano silver powder coating comprises, by weight, 10-20 parts of resin, 10-20 parts of graphene nano silver powder, 5-10 parts of carbon nano tubes, 10-20 parts of an organic solvent, 1-3 parts of a dispersing agent, 1-3 parts of a defoaming agent and 1-3 parts of an antioxidant.

2. The graphene composite conductive ink according to claim 1, wherein: the resin comprises any one or more of epoxy resin, phenolic resin, polyester resin, fluorocarbon resin, acrylic resin, polyamide resin and polyurethane resin.

3. The graphene composite conductive ink according to claim 1, wherein: the organic solvent comprises any one or more of ethanol, isopropanol, propylene glycol, acetone, tetrahydrofuran, ethyl formate and ethyl acetate.

4. The graphene composite conductive ink according to claim 1, wherein: the dispersing agent is any one of polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, styrene butadiene rubber, sodium carboxymethyl cellulose, hexadecyl ammonium bromide, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate and Triton X-100.

5. The graphene composite conductive ink according to claim 1, wherein: the defoaming agent is an organosiloxane defoaming agent.

6. The graphene composite conductive ink according to claim 1, wherein: the antioxidant is any one or more of BHT and 168.

7. The graphene composite conductive ink according to claim 1, wherein: the graphene nano silver powder is prepared by a photo-reduction method, and the method comprises the following specific steps:

placing graphene in a photocatalytic reaction tube, adding a hole capture agent into the reaction tube, performing ultrasonic treatment until the hole capture agent is uniformly dispersed, and adding silver nitrate (AgNO)₃) And (3) uniformly mixing the aqueous solution, placing the obtained mixed solution in visible light for illumination reduction reaction for 1-5h, and after the reaction is finished, centrifuging, washing and drying the product to obtain the graphene nano silver powder.

8. The graphene composite conductive ink according to claim 7, wherein: the using amount ratio of the graphene to the silver nitrate to the hole trapping agent is 0.5 part by mass: 0.8 part by mass: 100 parts by volume, wherein: the mass parts and volume parts are as follows: mL was used as a reference.

9. The graphene composite conductive ink according to claim 7, wherein: the hole trapping agent is any one of methanol, ethanol and formic acid.

10. The method for preparing the graphene composite conductive ink according to claim 1, wherein: the method comprises the following steps:

the first step is as follows: sequentially adding resin and an organic solvent into a high-speed shearing dispersion machine, and carrying out high-speed shearing dispersion for 20-40min to obtain a first solution;

the second step is that: slowly adding the graphene nano-silver powder and the carbon nano-tubes into the first solution obtained in the first step, continuously shearing and dispersing at a high speed for 30-60min, then sequentially adding the dispersing agent, the defoaming agent and the antioxidant, and continuously stirring for 20-40 min;

the third step: and (3) continuing ultrasonic dispersion treatment on the mixture obtained in the second step for 2-4h, then performing dispersion treatment by using a three-roll grinder, and grinding the mixture for multiple times by using the three-roll grinder to form uniform slurry, thereby finally obtaining the graphene composite conductive ink.

Technical Field

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

Background

Conductive ink refers to a paste ink made with conductive materials such as gold, silver, copper, and carbon dispersed in a vehicle. Has a certain degree of conductive property, and can be used for printing conductive points or conductive circuits. The conductive ink can be classified into two types, namely, a metallic type and a non-metallic type, according to the difference of the conductive filler. The metal conductive ink mainly uses noble metal as conductive filler, and its cost is very limited in practical application. In addition, the metal conductive ink has the defects of easy migration, poor sulfuration and resistance to solder corrosion, easy cracking in the sintering process and the like. The non-metal conductive ink mainly comprises carbon conductive ink. Although the carbon-based conductive ink is low in cost, the carbon-based conductive ink is poor in adhesion and unstable in coating structure, and quality problems are easy to occur in practical application. Common fillers in common carbon-based conductive ink, including carbon black, graphite, carbon fiber and the like, are low in cost, but poor in stability and low in conductivity, and obviously cannot meet the development requirements of the future printed electronic industry.

Graphene is a polymer made of carbon atoms in sp²The hexagonal honeycomb-lattice two-dimensional carbon nanomaterial formed by the hybrid tracks is the thinnest two-dimensional material in the world at present, has extremely excellent optical, electrical and mechanical properties, and has a large number of literature reports in the fields of materials science, micro-nano processing, photoelectric devices, biomedical materials and the like. With the development of graphene preparation technology, graphene conductive ink has been involved in various application fields including functional sensors, photovoltaic cells, flexible electronic screens, printed microcircuits, radio frequency identification and the like. However, the graphene conductive ink has poor dispersibility, is easy to agglomerate, has poor printability and is not beneficial to large-scale production. Therefore, the development of a novel conductive ink with low cost and high performance is a hot spot of current research. At present, reports of preparing conductive ink by compounding nano silver, graphene and carbon nano tubes are very goodLess.

Disclosure of Invention

Aiming at the problems or defects in the prior art, the invention aims to provide graphene composite conductive ink and a preparation method thereof.

In order to achieve the first object of the present invention, the present invention adopts the following technical solutions:

the graphene composite conductive ink comprises, by weight, 10-20 parts of resin, 10-20 parts of graphene nano silver powder, 5-10 parts of carbon nano tubes, 10-20 parts of an organic solvent, 1-3 parts of a dispersing agent, 1-3 parts of a defoaming agent and 1-3 parts of an antioxidant.

Further, in the above technical solution, the resin includes any one or more of epoxy resin, phenolic resin, polyester resin, fluorocarbon resin, acrylic resin, polyamide resin, and polyurethane resin.

Further, in the above technical solution, the organic solvent includes any one or more of ethanol, isopropanol, propylene glycol, acetone, tetrahydrofuran, ethyl formate, and ethyl acetate.

Further, in the technical scheme, the dispersant is any one of polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, styrene butadiene rubber, sodium carboxymethylcellulose, hexadecyl ammonium bromide, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate and TritonX-100 (polyethylene glycol octyl phenyl ether).

Further, in the technical scheme, the defoaming agent is an organosilicone defoaming agent.

Further, in the technical scheme, the antioxidant is any one or more of BHT and 168.

Further, according to the technical scheme, the graphene nano silver powder is prepared by a photo-reduction method, and the method comprises the following specific steps:

placing graphene in a photocatalytic reaction tube, adding a hole capture agent into the reaction tube, performing ultrasonic treatment until the hole capture agent is uniformly dispersed, and adding silver nitrate (AgNO)₃) Mixing the water solution, subjecting the obtained mixture to reduction reaction under visible light for 1-5 hr, centrifuging, and washingWashing and drying to obtain the graphene nano silver powder.

Preferably, in the technical scheme, the usage ratio of the graphene to the silver nitrate to the hole trapping agent is 0.5 parts by mass: 0.8 part by mass: 100 parts by volume, wherein: the mass parts and volume parts are as follows: mL was used as a reference.

Preferably, in the above technical solution, the visible light simulation light source is preferably a xenon lamp, the power of the xenon lamp is 600-1000W, and the wavelength λ is greater than 380 nm.

Preferably, in the above-mentioned technical means, the hole trapping agent is any one of methanol, ethanol, formic acid and the like, and ethanol is more preferable.

Preferably, in the above technical scheme, the drying manner is preferably vacuum drying, and the drying time is 10-30 h.

The second purpose of the present invention is to provide a preparation method of the graphene composite conductive ink, which comprises the following steps:

the first step is as follows: sequentially adding resin and an organic solvent into a high-speed shearing dispersion machine, and carrying out high-speed shearing dispersion for 20-40min to obtain a first solution;

the second step is that: slowly adding the graphene nano-silver powder and the carbon nano-tubes into the first solution obtained in the first step, continuously shearing and dispersing at a high speed for 30-60min, then sequentially adding the dispersing agent, the defoaming agent and the antioxidant, and continuously stirring for 20-40 min;

the third step: and (3) continuing ultrasonic dispersion treatment on the mixture obtained in the second step for 2-4h, then performing dispersion treatment by using a three-roll grinder, and grinding the mixture for multiple times by using the three-roll grinder to form uniform slurry, thereby finally obtaining the graphene composite conductive ink.

Further, in the above technical scheme, the high-speed shearing dispersion refers to dispersion performed under the condition that the rotating speed of the dispersion machine is not lower than 1000 r/min.

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

(1) when the graphene composite conductive ink prepared by the invention is used as a conductive agent, the conductive nano silver particles are well loaded on a graphene sheet, the structure is stable, the conductive nano silver particles are not easy to fall off, and meanwhile, the conductive nano silver particles are also used as nodes of a conductive network, so that the number of conductive network paths is increased, the conductive network of graphene can be assisted and perfected, the number of conductive particles in unit volume is increased, and the conductive nano silver particles are high in conductivity and low in resistivity;

(2) according to the invention, the nano-silver particles are loaded on the surface of the flake graphene, the carbon nano tubes are wound on the surface of the graphene nano-silver powder, the connection among the conductive particles is in a mode of point contact and surface contact, line contact and surface contact combination, the flake graphene and the rodlike carbon nano tubes have synergistic effect due to complementary shapes, the large-sheet-diameter graphene are mutually overlapped to form a conductive network framework, most of gaps are filled by the carbon nano tubes, so that the conductive network is more complete, the effective contact area among the conductive particles is greatly increased, the barrier of electrons in the migration process is reduced, and the conductivity is improved.

(3) The graphene composite conductive ink prepared by the invention has good printability, and the printed ink layer has the advantages of low resistivity, stable conductivity, good conductivity and the like, and has wide market application prospect;

(4) the graphene composite conductive ink and the preparation method thereof provided by the invention are characterized in that the graphene nano silver powder is prepared by utilizing a photo-reduction method for Ag⁺Reducing, under the irradiation of xenon lamp, the silver nano particles generate local surface plasma resonance effect to promote Ag⁺The silver is highly reduced into simple substance silver, the adding amount of the silver powder is reduced, and the preparation method has simple steps, low cost and easy operation;

(5) the graphene composite conductive ink prepared by the preparation method provided by the invention is strong in adhesive force and high in hardness.

Detailed Description

The present invention will be described in further detail below with reference to examples. The present invention is implemented on the premise of the technology of the present invention, and the detailed embodiments and specific procedures are given to illustrate the inventive aspects of the present invention, but the scope of the present invention is not limited to the following embodiments.

Various modifications to the precise description of the invention will be readily apparent to those skilled in the art from the information contained herein without departing from the spirit and scope of the appended claims. It is to be understood that the scope of the invention is not limited to the procedures, properties, or components defined, as these embodiments, as well as others described, are intended to be merely illustrative of particular aspects of the invention. Indeed, various modifications of the embodiments of the invention which are obvious to those skilled in the art or related fields are intended to be covered by the scope of the appended claims.

For a better understanding of the invention, and not as a limitation on the scope thereof, all numbers expressing quantities, percentages, and other numerical values used in this application are to be understood as being modified in all instances by the term "about". Accordingly, unless expressly indicated otherwise, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

The materials, reagents and the like used in the following examples are commercially available without specific description, and the resins used therein are all conventional reagents and are not limited by the manufacturer.