KR-102963365-B1 - Core-shell form of transition metal nanoparticle-silver bonded graphene complex and ink for printed electronics using the same

KR102963365B1KR 102963365 B1KR102963365 B1KR 102963365B1KR-102963365-B1

Abstract

The present application relates to a graphene composite in which a silver coating layer is present on the surface of transition metal nanoparticles and graphene is chemically bonded to the transition metal nanoparticles. Specifically, the invention relates to an ink for electronic printing using the graphene composite.

Inventors

최선용
신명선
이순직
연정미
오성택

Assignees

재단법인 철원플라즈마 산업기술연구원

Dates

Publication Date: 20260508
Application Date: 20210108

Claims (11)

A composite comprising graphene, transition metal nanoparticles, and silver, The transition metal nanoparticles are carbide-bonded to the surface of the graphene, and The above transition metal nanoparticles have an average particle diameter of 10 to 100 nm and are distributed on the surface of the graphene, The silver (Ag) forms a coating layer only on the surface of the transition metal nanoparticles, the coating layer has an average thickness of 4 nm, and the silver does not form carbide bonds with the graphene, At this time, the graphene composite is characterized in that the transition metal nanoparticles are included in an amount of 1% or more and 4% or less of the total weight of the composite, and the silver (Ag) is included in an amount of 1% or more and 4% or less of the total weight of the composite.
In Article 1, A graphene composite characterized in that the above transition metal nanoparticles are one or more particles selected from the group consisting of Ni, Si, Ti, Cr, Mn, Fe, Co, Cu, Sn, In, Pt, Au, Mg and combinations thereof.
In Article 1, A graphene composite characterized in that the above transition metal nanoparticles are Ni.
In Article 1, The graphene composite is characterized by additionally including palladium (Pd) between the surface of the transition metal nanoparticles and the silver coating layer.
A graphene composite according to claim 1 or 4; and Ink composition for printed electronics comprising water or an organic solvent.
In Paragraph 5, An ink composition for printed electronics characterized by the average particle size of the graphene composite being 3 μm or more and 5 μm or less.
In Paragraph 5, The sheet resistance converted to a thickness of 10 µm when printed with a line width of 30 µm is A printed electronics ink composition characterized by having a value of 0.01 Ω/sq/mil or more and 1 Ω/sq/mil or less.
In Paragraph 5, An ink composition for printed electronics characterized in that the above organic solvent is isopropyl alcohol or NMP (N-methyl-2-pyrrolidone, N-methyl-2-pyrrolidone, C5H9NO).
A method for manufacturing the graphene composite of claim 4, comprising the following: (i) a step of immersing graphene, on which transition metal nanoparticles are chemically bonded to the surface, in a solution mixed with tin (Sn), palladium (Pd), and acid, wherein tin and palladium are ionized in the solution, and as tin ions are oxidized, palladium ions are reduced to metallic palladium and chemically adsorbed onto the surface of the transition metal nanoparticles; (ii) A step of immersing the product of step (i) in a solution containing silver ions; (iii) a step of treating with a reducing agent, wherein the silver ions are reduced to metallic silver by receiving electrons from the reducing agent and coat the surface of the transition metal nanoparticles on which palladium is adsorbed; and (iv) A step of obtaining the graphene composite of claim 4.
In Article 9, A method characterized in that the reducing agent is formaldehyde.
In Article 9, A method characterized in that the above acid is hydrochloric acid or sulfuric acid.

Description

Core-shell form of transition metal nanoparticle-silver bonded graphene complex and ink for printed electronics using the same. The present application relates to a graphene composite in which a silver coating layer is present on the surface of transition metal nanoparticles and graphene is chemically bonded to the transition metal nanoparticles. Specifically, the invention relates to an ink for electronic printing using the graphene composite. Printed electronics refers to electronic circuits or electronic products created by printing functional inks, such as conductive, insulating, or semiconducting inks, onto various substrates (plastic, film, paper, glass, etc.). Because it can be printed not only on conventional rigid substrates but also on thin films, it can be utilized in flexible displays or smart labels. Printed electronics utilizes special inks made from materials that constitute electronic circuits, and the core of the printing process lies in transferring the designed circuit pattern onto a target object using an inkjet printer or laminator. Therefore, the driving technology of printers or laminators and the production of special inks can be considered the center of printed electronics technology. Printed electronics inks are primarily used for electrodes and wiring in various RFID devices, and the most critical property required for the conductive lines formed is conductivity. The next most important requirements include low process temperature, low manufacturing cost, and ink stability. For carbon material-based inks such as graphene, smaller carbon material sizes are advantageous for printing fine line widths of electrodes and wiring in various RFID devices. However, since carbon materials, which are two-dimensional nanomaterials, exhibit higher conductivity as the contact surface between particles widens, conductivity decreases as particle size decreases. Therefore, in order to use carbon material-based inks for printed electronics, it is necessary to find a method that maintains conductivity even when particle size is reduced. Figure 1 shows amorphous silver powder and silver flakes. Figure 2 shows the analysis of the sheet resistance of a graphene composite or graphene according to the silver powder content. Figure 3 shows a schematic diagram of a graphene composite. Figure 4 shows the form in which nickel is bonded to graphene and the graphene composite. Figure 5 shows graphene and the form in which nickel is bonded to graphene. Figure 6 is a schematic diagram of a method for manufacturing a graphene composite using an electroless plating method. Figure 7 is a table showing the manufacturing method of the electroless plating method of Figure 6. Figure 8 shows the graphene composite observed. Figure 9 shows the viscosity and characteristics of an ink for printed electronics composed of a graphene composite. Figure 10 is a photograph of a printed product of an ink composition for printed electronics. Figure 11 shows the printing continuity confirmed with an ink composition for printed electronics. Figure 12 analyzes the characteristics of an ink composition for printed electronics. To describe the contents disclosed herein, various terms will be defined in this specification. In addition to these terms, other terms are defined elsewhere in this specification where necessary. Unless otherwise explicitly defined herein, industry terms used herein shall have the meanings recognized in the industry. In case of conflict, the definitions in this specification shall prevail. Problems with conventional ink compositions for printed electronics Indium tin oxide (ITO) and silver flake inks are the most widely used for electronic printing on conventional electronic components. Demand for carbon-based electronic printing inks is increasing due to their flexibility to print on various substrates and their status as low-cost organic conductive materials. For fine linewidth printing, carbon-based electronic printing inks, such as graphene, are advantageous when the size of the carbon material is smaller. However, for carbon materials, such as graphene, which are two-dimensional nanomaterials, conductivity decreases as the size of the carbon material decreases. Therefore, to use them as electronic printing inks, it is important to maintain high conductivity while using small-sized carbon materials. For example, to print fine lines with a width of 30 µm using graphene ink, the average graphene particle size must be approximately 10 µm. In the case of ink using graphene powder with an actual average particle size of 20 µm, the sheet resistance is about 0.9 Ω/sq, whereas in the case of ink using graphene powder with an average particle size of 5 µm, the sheet resistance increases by more than double to 2.2 to 2.3 Ω/sq. In other words, conductivity decreases. Therefore, in order to solve the various problems described above, the present application aims to provide a graphene composite that maintains high conduc