Transparent conductive paste and preparation method and application thereof

Abstract

The invention provides transparent conductive paste and a preparation method and application thereof, and belongs to the technical field of transparent conductive paste. The silver nanowires and the carbon nanotubes are added and have a synergistic effect, the conductivity of the conductive paste can be further improved, the PEDOT / PSS not only has excellent conductivity, but also has relatively good film-forming property, and can be filled in gaps between the silver nanowires and the carbon nanotubes to form a more complete conductive path, so that the conductivity of the conductive paste is improved, and the conductive performance of the conductive paste is improved. The dispersing agent is added to improve the dispersity of the carbon nanotubes and the silver nanowires, the binder is added to enable the conductive paste to be better combined with a matrix during use, and the defoaming agent is added to prevent bubbles from being generated in the paste, so that the defects of needle eyes, holes and the like on the surface of a film layer after printing and drying are avoided; the composition of the conductive slurry and the use amount of each component are controlled, so that the conductive slurry has excellent conductivity.

Description

Technical Field

[0001] The present invention belongs to the technical field of transparent conductive pastes, and in particular relates to a transparent conductive paste and a preparation method and application thereof. Background Art

[0002] With the rapid development of electronic technology, transparent conductive materials are widely used in many fields such as touch screens, flat panel displays, solar cells, etc. The traditional transparent conductive material is mainly indium tin oxide, which has good conductivity and high transparency, but the reserves of indium and tin are small, and they need to be produced by vacuum sputtering, which makes them expensive and not conducive to large-scale application. In recent years, nanosilver particles or nanosilver wires have gradually replaced indium tin oxide as the mainstream conductive material. Generally, nanosilver wires are prepared into conductive paste with film-forming materials such as epoxy resins and additives such as defoaming agents, and then patterned by screen printing. However, the conductive performance of the conductive paste prepared by existing nanosilver particles or nanosilver wires still needs to be further improved. Summary of the invention

[0003] The purpose of the present invention is to provide a transparent conductive paste and a preparation method and application thereof. The transparent conductive paste provided by the present invention has better conductive properties.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a transparent conductive paste, which comprises the following components by weight: 10 to 30 parts of nano silver wires, 1 to 6 parts of carbon nano tubes, 15 to 30 parts of PEDOT / PSS, 2 to 5 parts of dispersants, 1 to 5 parts of binders, 0.1 to 2 parts of defoamers and 30 to 70 parts of solvents.

[0006] Preferably, the diameter of the silver nanowire is 20-50 nm, and the length of the silver nanowire is 10-50 μm.

[0007] Preferably, the diameter of the carbon nanotube is 10-30 nm, and the length of the carbon nanotube is 1-15 μm.

[0008] Preferably, the dispersant includes one or more of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether and polyethylene glycol.

[0009] Preferably, the binder includes one or more of acrylic resin, polyurethane resin and phenolic resin.

[0010] Preferably, the defoaming agent includes one or more of an organosilicon defoaming agent and a polyether defoaming agent.

[0011] Preferably, the solvent includes one or more of water, ethanol, isopropanol, octanol, dodecanol, N,N-dimethylformamide and ethylene glycol monobutyl ether.

[0012] The present invention also provides a method for preparing the transparent conductive paste described in the above technical solution, comprising the following steps:

[0013] (1) mixing the silver nanowires with a portion of the solvent to obtain a silver nanowire dispersion;

[0014] (2) mixing the carbon nanotubes and a portion of the solvent to obtain a carbon nanotube dispersion;

[0015] (3) mixing PEDOT / PSS and the remaining solvent to obtain a PEDOT / PSS dispersion;

[0016] (4) mixing the silver nanowire dispersion obtained in step (1), the carbon nanotube dispersion obtained in step (2), the PEDOT / PSS dispersion obtained in step (3), a dispersant, a binder and a defoaming agent to obtain a transparent conductive paste;

[0017] There is no order of precedence for steps (1) to (3).

[0018] The present invention also provides the use of the transparent conductive paste described in the above technical solution or the transparent conductive paste prepared according to the preparation method described in the above technical solution in electrodes of electronic devices.

[0019] Preferably, the transparent conductive paste is screen-printed on the surface of the substrate to obtain an electrode.

[0020] The present invention provides a transparent conductive paste, which comprises the following components by weight: 10 to 30 parts of nano silver wires, 1 to 6 parts of carbon nanotubes, 15 to 30 parts of PEDOT / PSS, 2 to 5 parts of dispersants, 1 to 5 parts of binders, 0.1 to 2 parts of defoamers and 30 to 70 parts of solvents. The present invention adds nano silver wires and carbon nanotubes, which have a synergistic effect and can further improve the conductive performance of the conductive paste. PEDOT / PSS not only has excellent conductivity, but also has good film-forming properties, and can be filled in the gaps between nano silver wires and carbon nanotubes to form a more complete conductive path, thereby improving the conductivity of the conductive paste. The dispersant is added to improve the dispersibility of the carbon nanotubes and nano silver wires, the binder is added to make the conductive paste better combined with the substrate when used, and the defoamer is added to avoid bubbles in the paste, thereby avoiding defects such as pinholes and holes on the surface of the film layer after printing and drying; the composition of the conductive paste and the amount of each component are controlled, so that the conductive paste has excellent conductive properties. The results of the examples show that the sheet resistance of the transparent conductive paste provided by the present invention is below 70Ω / □. DETAILED DESCRIPTION

[0021] The present invention provides a transparent conductive paste, which comprises the following components by weight: 10 to 30 parts of nano silver wires, 1 to 6 parts of carbon nano tubes, 15 to 30 parts of PEDOT / PSS, 2 to 5 parts of dispersants, 1 to 5 parts of binders, 0.1 to 2 parts of defoamers and 30 to 70 parts of solvents.

[0022] Unless otherwise specified, the present invention has no particular limitation on the sources of the components, and commercially available products known to those skilled in the art may be used.

[0023] The transparent conductive paste provided by the present invention includes 10 to 30 parts of nano silver wires by weight. In an embodiment of the present invention, the amount of the nano silver wires may be specifically 10 parts, 15 parts, 20 parts, 25 parts or 30 parts.

[0024] In the present invention, the diameter of the nano silver wire is preferably 20 to 50 nm; the length of the nano silver wire is preferably 10 to 50 μm. The present invention controls the amount, diameter and length of the nano silver wire within the above range, which can form a more continuous and complete conductive network and further improve the conductivity of the transparent conductive paste.

[0025] Based on 10 to 30 parts by mass of nano silver wires, the transparent conductive paste provided by the present invention includes 1 to 6 parts of carbon nanotubes. In an embodiment of the present invention, the amount of the carbon nanotubes can be specifically 1 part, 2 parts, 3 parts, 4 parts, 5 parts or 6 parts.

[0026] In the present invention, the carbon nanotubes preferably include at least one of single-walled carbon nanotubes, double-walled carbon nanotubes and multi-walled carbon nanotubes.

[0027] In the present invention, the diameter of the carbon nanotube is preferably 10 to 30 nm; the length of the carbon nanotube is preferably 1 to 15 μm. The present invention adds carbon nanotubes and controls their dosage, diameter and length within the above ranges, which can synergize with nano silver wires to form a more complete and continuous conductive network, further improving the conductivity of the transparent conductive paste.

[0028] Based on the mass of nano silver wire being 10 to 30 parts, the transparent conductive paste provided by the present invention includes 15 to 30 parts of PEDOT / PSS. In an embodiment of the present invention, the amount of PEDOT / PSS may be specifically 15 parts, 20 parts, 25 parts or 30 parts. The present invention adds PEDOT / PSS, which not only has excellent conductivity, but also has good film-forming properties, can fill the gaps between nano silver wires and carbon nanotubes, form a more complete conductive path, and improve the conductivity of the conductive paste. The present invention controls the amount of PEDOT / PSS within the above range, which can further improve the conductivity of the transparent conductive paste.

[0029] Based on 10 to 30 parts by mass of the nano silver wire, the transparent conductive paste provided by the present invention includes 2 to 5 parts of a dispersant. In an embodiment of the present invention, the amount of the dispersant may be specifically 2 parts, 3 parts, 4 parts or 5 parts.

[0030] In the present invention, the dispersant preferably includes one or more of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether and polyethylene glycol. The present invention adds a dispersant to improve the dispersibility of carbon nanotubes and nano silver wires. The present invention controls the amount and type of the dispersant within the above range, which can further improve the conductivity of the transparent conductive paste.

[0031] Based on 10 to 30 parts by mass of the nano silver wire, the transparent conductive paste provided by the present invention includes 1 to 5 parts of a binder. In an embodiment of the present invention, the amount of the binder can be specifically 1 part, 2 parts, 3 parts, 4 parts or 5 parts.

[0032] In the present invention, the binder preferably includes one or more of acrylic resin, polyurethane resin and phenolic resin, and is more preferably an acrylic resin emulsion. In the present invention, the solid content of the acrylic resin emulsion is preferably 30-60%, and more preferably 40-55%. The present invention adds a binder to enable the conductive paste to be better combined with the substrate when used. The present invention controls the amount and type of the binder within the above range, so that the transparent conductive paste has better adhesion to the substrate.

[0033] Based on 10 to 30 parts by mass of the nano silver wire, the transparent conductive paste provided by the present invention includes 0.1 to 2 parts of a defoaming agent. In an embodiment of the present invention, the amount of the defoaming agent can be specifically 0.1 parts, 0.5 parts, 1 parts, 1.5 parts or 2 parts.

[0034] In the present invention, the defoamer preferably includes one or more of a silicone defoamer and a polyether defoamer. The present invention has no special limitation on the source of the defoamer, and commercially available products known to those skilled in the art may be used. In an embodiment of the present invention, the defoamer may specifically be RHODOLINE DF 4226 produced by Solvay. The defoamer is added to the present invention to avoid the generation of bubbles in the slurry, thereby avoiding defects such as pinholes and holes on the surface of the film layer after printing and drying, and improving the conductivity of the transparent conductive slurry. The present invention controls the amount and type of the defoamer within the above range, which can further improve the conductivity of the transparent conductive slurry.

[0035] Based on 10 to 30 parts by mass of the nano silver wire, the transparent conductive paste provided by the present invention includes 30 to 70 parts of solvent. In an embodiment of the present invention, the amount of the solvent may be specifically 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts or 70 parts.

[0036] In the present invention, the solvent preferably includes one or more of water, ethanol, isopropanol, octanol, dodecanol, N,N-dimethylformamide and ethylene glycol monobutyl ether. The present invention controls the type and amount of the solvent so that each component can be fully dispersed or dissolved.

[0037] The present invention controls the composition of the conductive paste and the amount of each component, so that the conductive paste has excellent conductive performance.

[0038] The present invention also provides a method for preparing the transparent conductive paste described in the above technical solution, comprising the following steps:

[0039] (1) mixing the silver nanowires with a portion of the solvent to obtain a silver nanowire dispersion;

[0040] (2) mixing the carbon nanotubes and a portion of the solvent to obtain a carbon nanotube dispersion;

[0041] (3) mixing PEDOT / PSS and the remaining solvent to obtain a PEDOT / PSS dispersion;

[0042] (4) mixing the silver nanowire dispersion obtained in step (1), the carbon nanotube dispersion obtained in step (2), the PEDOT / PSS dispersion obtained in step (3), a dispersant, a binder and a defoaming agent to obtain a transparent conductive paste;

[0043] There is no order of precedence for steps (1) to (3).

[0044] The invention mixes the nano silver wires with part of the solvent to obtain the nano silver wire dispersion.

[0045] In the present invention, the mass of the partial solvent is preferably 10 to 40% of the total mass of the solvent.

[0046] The present invention has no special limitation on the mixing operation of the nano silver wires and part of the solvent, and a technical solution for mixing materials well known to those skilled in the art can be adopted.

[0047] The present invention mixes carbon nanotubes and part of solvent to obtain carbon nanotube dispersion.

[0048] In the present invention, the mass of the partial solvent is preferably 10 to 40% of the total mass of the solvent.

[0049] The present invention has no special limitation on the operation of mixing the carbon nanotubes and part of the solvent, and a technical solution for mixing materials well known to those skilled in the art can be adopted.

[0050] The present invention mixes PEDOT / PSS and the remaining solvent to obtain a PEDOT / PSS dispersion.

[0051] The present invention has no special limitation on the mixing operation of the PEDOT / PSS and the remaining solvent, and a technical solution for mixing materials well known to those skilled in the art may be adopted.

[0052] After obtaining the nano silver wire dispersion, the carbon nanotube dispersion and the PEDOT / PSS dispersion, the present invention mixes the nano silver wire dispersion, the carbon nanotube dispersion, the PEDOT / PSS dispersion, a dispersant, a binder and a defoamer to obtain a transparent conductive paste.

[0053] The present invention has no special limitation on the mixing operation of the nano silver wire dispersion, carbon nanotube dispersion, PEDOT / PSS dispersion, dispersant, binder and defoamer, and the technical scheme of material mixing well known to those skilled in the art can be adopted.

[0054] The mixing method of the present invention can make the components mixed or dispersed more uniformly.

[0055] The present invention also provides the use of the transparent conductive paste described in the above technical solution or the transparent conductive paste prepared according to the preparation method described in the above technical solution in electrodes of electronic devices.

[0056] In the present invention, the transparent conductive paste is preferably screen-printed on the surface of the substrate to obtain an electrode.

[0057] The present invention has no particular limitation on the type and size of the substrate, and any substrate well known to those skilled in the art may be used.

[0058] The present invention has no special limitation on the operation of the screen printing, and the screen printing technical solution well known to those skilled in the art can be adopted.

[0059] The transparent conductive paste provided by the present invention has excellent conductive performance and can improve the conductivity of the electrode when used in the electrode.

[0060] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] Example 1

[0062] A transparent conductive paste, composed of the following components by weight: 12 parts of nano silver wires (diameter of 20-50 nm, length of 10-50 μm), 2 parts of multi-walled carbon nanotubes (diameter of 10-30 nm, length of 1-15 μm), 15 parts of PEDOT / PSS, 2 parts of polyvinyl pyrrolidone dispersant, 2 parts of acrylic resin emulsion (solid content of 48%) binder, 0.5 parts of defoamer (RHODOLINE DF 4226 produced by Solvay) and 50 parts of solvent (20 parts of water, 30 parts of ethylene glycol monobutyl ether);

[0063] The preparation method of the transparent conductive paste is as follows: (1) mixing nano silver wires and 15 parts of ethylene glycol monobutyl ether to obtain a nano silver wire dispersion;

[0064] (2) mixing carbon nanotubes and 15 parts of ethylene glycol monobutyl ether to obtain a carbon nanotube dispersion;

[0065] (3) mixing PEDOT / PSS and water to obtain a PEDOT / PSS dispersion;

[0066] (4) Mixing the silver nanowire dispersion obtained in step (1), the carbon nanotube dispersion obtained in step (2), the PEDOT / PSS dispersion obtained in step (3), a dispersant, a binder and a defoaming agent to obtain a transparent conductive paste.

[0067] Example 2

[0068] A transparent conductive paste, composed of the following components by weight: 18 parts of nano silver wires (diameter of 20-50 nm, length of 10-50 μm), 5 parts of multi-walled carbon nanotubes (diameter of 10-30 nm, length of 1-15 μm), 20 parts of PEDOT / PSS, 3 parts of polyvinyl pyrrolidone dispersant, 2 parts of acrylic resin emulsion (solid content of 48%) binder, 0.5 parts of defoamer (RHODOLINE DF 4226 produced by Solvay) and 60 parts of solvent (20 parts of water, 40 parts of ethylene glycol monobutyl ether);

[0069] The preparation method of the transparent conductive paste is the same as that of Example 1.

[0070] Example 3

[0071] A transparent conductive paste, composed of the following components by weight: 30 parts of nano silver wires (diameter of 20-50 nm, length of 10-50 μm), 6 parts of multi-walled carbon nanotubes (diameter of 10-30 nm, length of 1-15 μm), 30 parts of PEDOT / PSS, 5 parts of polyvinyl pyrrolidone dispersant, 4 parts of acrylic resin emulsion (solid content of 48%), 1 part of defoamer (RHODOLINE DF 4226 produced by Solvay) and 70 parts of solvent (30 parts of water, 40 parts of ethylene glycol monobutyl ether);

[0072] The preparation method of the transparent conductive paste is the same as that of Example 1.

[0073] Comparative Example 1

[0074] The silver nanowires in Example 3 were omitted, the amount of multi-walled carbon nanotubes was changed to 36 parts, and the other parameters and preparation method were the same as those in Example 3.

[0075] Comparative Example 2

[0076] The multi-walled carbon nanotubes in Example 3 were omitted, the amount of the nanosilver wires was changed to 36 parts, and the other parameters and preparation method were the same as those in Example 3.

[0077] The transparent conductive pastes of Examples 1 to 3 and Comparative Examples 1 to 2 were screen printed onto a glass plate and then dried. The square resistance of the coating was tested using a four-probe tester. The square resistance of the coating formed by the transparent conductive pastes of Examples 1 to 3 and Comparative Examples 1 to 2 is shown in Table 1.

[0078] Table 1 Sheet resistance of the coatings formed by the transparent conductive pastes of Examples 1 to 3 and Comparative Examples 1 to 2

[0079] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Square resistance 65Ω / □ 52Ω / □ 47Ω / □ 90Ω / □ 98Ω / □

[0080] It can be seen from the above data that the transparent conductive paste provided by the present invention has better conductivity.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A transparent conductive paste, comprising the following components by weight: 10 to 30 parts of nano silver wires, 1 to 6 parts of carbon nanotubes, 15 to 30 parts of PEDOT / PSS, 2 to 5 parts of dispersant, 1 to 5 parts of binder, 0.1 to 2 parts of defoamer and 30 to 70 parts of solvent.

2. The transparent conductive paste according to claim 1, characterized in that: The diameter of the nano silver wire is 20-50 nm, and the length of the nano silver wire is 10-50 μm.

3. The transparent conductive paste according to claim 1, characterized in that: The diameter of the carbon nanotube is 10-30 nm, and the length of the carbon nanotube is 1-15 μm.

4. The transparent conductive paste according to claim 1, characterized in that: The dispersant includes one or more of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether and polyethylene glycol.

5. The transparent conductive paste according to claim 1, characterized in that: The binder includes one or more of acrylic resin, polyurethane resin and phenolic resin.

6. The transparent conductive paste according to claim 1, characterized in that: The defoaming agent includes one or more of an organosilicon defoaming agent and a polyether defoaming agent.

7. The transparent conductive paste according to claim 1, characterized in that: The solvent includes one or more of water, ethanol, isopropanol, octanol, dodecanol, N,N-dimethylformamide and ethylene glycol monobutyl ether.

8. The method for preparing the transparent conductive paste according to any one of claims 1 to 7, comprising the following steps: (1) mixing the silver nanowires with a portion of the solvent to obtain a silver nanowire dispersion; (2) mixing the carbon nanotubes and a portion of the solvent to obtain a carbon nanotube dispersion; (3) mixing PEDOT / PSS and the remaining solvent to obtain a PEDOT / PSS dispersion; (4) mixing the silver nanowire dispersion obtained in step (1), the carbon nanotube dispersion obtained in step (2), the PEDOT / PSS dispersion obtained in step (3), a dispersant, a binder and a defoaming agent to obtain a transparent conductive paste; There is no order of precedence for steps (1) to (3).

9. Use of the transparent conductive paste according to any one of claims 1 to 7 or the transparent conductive paste prepared by the preparation method according to claim 8 in electrodes of electronic devices.

10. The use according to claim 9, characterized in that: The transparent conductive paste is screen-printed on the surface of the substrate to obtain an electrode.