Preparation process of conductive film

Abstract

The invention discloses a preparation process of a conductive film, and the conductive film comprises a transparent substrate layer and a conductive layer located on the surface of the transparent substrate layer. Comprising the following steps that firstly, silver nanowires, polyvinyl butyral, polyvinylpyrrolidone, a dispersing agent, a silane coupling agent, a flatting agent and polycitric acid are sequentially put into a solvent, a uniform mixed solution is formed through magnetic stirring, then standing is conducted for 1-2 hours, the diameter of the silver nanowires is 30-50 nm, and the length of the silver nanowires is 15-30 microns; 2, performing corona treatment on the transparent substrate layer through plasma; and step 3, coating the surface of the transparent substrate layer subjected to standing and corona treatment, and drying at 40-80 DEG C to obtain the transparent conductive film. According to the conductive film obtained through the preparation technology, the low surface resistance is maintained, meanwhile, the yellowness value of the film is reduced, and the light transmittance stability and the appearance effect of the transparent conductive film are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive films, and particularly to a preparation process of a conductive film. Background Art

[0002] As a functional film with high light transmittance and low film resistance, the transparent conductive film is widely used in fields such as touch screens, display panels, electromagnetic shielding, LED displays, electroluminescent devices, and thin-film solar cells.

[0003] Due to the disadvantages of existing transparent conductive films, such as resource shortage, high price, and easy appearance of defects, currently, those skilled in the art are committed to developing new alternative materials for use in transparent conductive films. Among them, metal nanomaterials, especially nano-silver materials, have become the most promising alternative materials for commercial use. The existing nano-silver transparent conductive films will turn yellow after long-term use, thus affecting their light transmittance. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preparation process of a conductive film. The conductive film obtained by this preparation process maintains a low surface resistance while reducing the yellowness value of the film, ensuring the light transmittance stability and appearance effect of the transparent conductive film.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a preparation process of a conductive film, the conductive film includes: a transparent substrate layer, and a conductive layer located on the surface of the transparent substrate layer, and includes the following steps:

[0006] Step 1: Sequentially put 10 - 15 parts of silver nanowires, 2 - 5 parts of polyvinyl butyral, 1 - 3 parts of polyvinylpyrrolidone, 0.1 - 0.5 parts of a dispersant, 0.3 - 1.5 parts of a silane coupling agent, 0.1 - 1 part of a leveling agent, and 0.2 - 0.6 parts of polycitric acid into 100 parts of a solvent, and form a uniform mixed solution by magnetic stirring. Then, let it stand for 1 - 2 hours. The diameter of the silver nanowires is 30 - 50 nm, and the length is 15 - 30 μm.

[0007] Step 2: Perform corona treatment on the transparent substrate layer by plasma.

[0008] Step 3: Coat the mixture standing still on the surface of the corona-treated transparent substrate layer, and dry it at 40 - 80 °C to obtain a transparent conductive film.

[0009] The further improved technical solutions in the above technical solutions are as follows:

[0010] 1. In the above solution, the dispersant is 2-amino-2-methyl-1-propanol, ethanolamine, or diethyl phthalate.

[0011] 2. In the above solution, the leveling agent is isopropanol, propylene glycol monomethyl ether, diacetone alcohol or ethylene glycol monobutyl ether.

[0012] 3. In the above solution, the transparent substrate layer is a PET substrate layer, a PE substrate layer, a PP substrate layer or a PI substrate layer.

[0013] 4. In the above solution, the solvent is methanol, ethanol or isopropanol.

[0014] 5. In the above solution, the drying time in Step 3 is 30 to 60 minutes.

[0015] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0016] For the preparation process of the conductive film of the present invention, the conductive layer of the obtained conductive film is based on 10 - 15 parts of silver nanowires, 2 - 5 parts of polyvinyl butyral, and 1 - 3 parts of polyvinylpyrrolidone and 0.2 - 0.6 parts of polycitric acid are added, so that while maintaining a low surface resistance, the yellowing value of the film is reduced, ensuring the light transmittance stability and appearance effect of the transparent conductive film. Detailed Embodiments

[0017] The present patent can be further clearly understood through the following specific embodiments given, but they do not limit the present patent.

[0018] The present invention will be further described below in conjunction with the embodiments:

[0019] Embodiments 1 - 4: A preparation process of a conductive film, the conductive film includes: a transparent substrate layer, and a conductive layer located on the surface of the transparent substrate layer, and this conductive layer is obtained by coating and drying a conductive liquid, and the conductive liquid is composed of the following components in parts by weight, as shown in Table 1:

[0020] Table 1

[0021] Component Example 1 Example 2 Example 3 Example 4 Solvent 100 parts 100 parts 100 parts 100 parts Silver nanowire 12 parts 10 parts 12 parts 14 parts Polyvinyl butyral 3 parts 5 parts 3 parts 4 parts Polyvinylpyrrolidone 2 parts 1 part 2 parts 2 parts Dispersant 0.3 part 0.2 part 0.3 part 0.2 part Silane coupling agent 1 part 0.7 part 1 part 0.6 part Leveling agent 0.5 part 0.6 part 0.4 part 0.4 part Polycitric acid 0.3 part 0.2 part 0.2 part 0.3 part ;

[0022] It includes the following steps:

[0023] Step 1: Sequentially put silver nanowires, polyvinyl butyral, polyvinylpyrrolidone, a dispersant, a silane coupling agent, a leveling agent, and polycitric acid into a solvent and form a uniform mixed solution through magnetic stirring, and then, let it stand for 1 - 2 hours. The diameter of the silver nanowires is 30 - 50 nm, and the length is 15 - 30 μm;

[0024] Step 2: Perform corona treatment on the transparent substrate layer through plasma;

[0025] Step 3: Apply the mixture to the surface of the corona-treated transparent substrate layer and dry it at 50°C to obtain a transparent conductive film.

[0026] In Step 3 above, the drying time is 50 minutes.

[0027] In Example 1, the transparent substrate layer is a PET substrate layer, the above solvent is methanol, the above leveling agent is propylene glycol methyl ether, and the above dispersant is diethyl phthalate.

[0028] In Example 2, the transparent substrate layer is a PP substrate layer, the above solvent is methanol, the above leveling agent is propylene glycol methyl ether, and the above dispersant is 2-amino-2-methyl-1-propanol.

[0029] In Example 3, the transparent substrate layer is a PET substrate layer, the above solvent is methanol, the above leveling agent is isopropyl alcohol, and the above dispersant is 2-amino-2-methyl-1-propanol.

[0030] In Example 4, the transparent substrate layer is a PP substrate layer, the above solvent is ethanol, the above leveling agent is ethylene glycol monobutyl ether, and the above dispersant is diethyl phthalate.

[0031] Comparative Examples 1-3: A preparation process of a conductive film, the conductive film includes: a transparent substrate layer, a conductive layer on the surface of the transparent substrate layer, and this conductive layer is obtained by coating and drying a conductive liquid. The conductive liquid is composed of the following components in parts by weight, as shown in Table 2:

[0032] Table 2

[0033] Component Comparative Example 1 Comparative Example 2 Comparative Example 3 Solvent 100 parts 100 parts 100 parts Silver nanowire 12 parts 12 parts 12 parts Polyvinyl butyral 3 parts 3 parts 3 parts Polyvinylpyrrolidone - 2 parts - Dispersant 0.3 part 0.3 part 0.3 part Silane coupling agent 1 part 1 part 1 part Leveling agent 0.5 part 0.5 part 0.4 part Polycitric acid 0.3 part - - ;

[0034] The steps of the comparative examples are the same as those of the examples. The above silver nanowires have a diameter of 30-50 nm and a length of 15-30 μm.

[0035] In Comparative Examples 1-2, the transparent substrate layer is a PET substrate layer, the above solvent is methanol, the above leveling agent is propylene glycol methyl ether, and the above dispersant is diethyl phthalate.

[0036] In Comparative Example 3, the transparent substrate layer is a PP substrate layer, the above solvent is methanol, the above leveling agent is propylene glycol methyl ether, and the above dispersant is 2-amino-2-methyl-1-propanol.

[0037] For the transparent conductive films obtained by the preparation processes of the above Examples 1-4 and Comparative Examples 1-3, their surface resistances are measured with a four-probe instrument, and the yellowness values are detected by a HunterLab colorimeter. The samples are irradiated with an ultraviolet lamp for 10 minutes before detecting the yellowness values. The corresponding performances are shown in Table 3:

[0038] Table 3

[0039] Sheet resistance / Ω / □ Yellowness value / B Example 1 173 1.672 Example 2 183 1.714 Example 3 182 1.753 Example 4 176 1.681 Comparative Example 1 196 1.932 Comparative Example 2 201 2.023 Comparative Example 3 192 1.911 ;

[0040] As shown in the evaluation results of Table 3, for the conductive films obtained by the preparation processes of Examples 1 to 4 of the present invention, the sheet resistance / Ω / □ is lower than 185 Ω / □, and the yellowness values are 1.672, 1.714, 1.753, and 1.681 respectively; for the conductive films obtained by the preparation processes of Comparative Examples 1 to 3, the sheet resistance is greater than 190 Ω / □, and the yellowness values all exceed 1.9. The conductive film obtained by the preparation process of this example not only maintains a low surface resistance but also reduces the yellowness value of the film, ensuring the transmittance stability and appearance effect of the transparent conductive film.

[0041] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A preparation process of a conductive thin film, characterized in that: The conductive thin film includes: a transparent substrate layer and a conductive layer located on the surface of the transparent substrate layer, and the method comprises the following steps: Step 1: Add 10-15 parts of silver nanowires, 2-5 parts of polyvinyl butyral, 1-3 parts of polyvinylpyrrolidone, 0.1-0.5 parts of dispersant, 0.3-1.5 parts of silane coupling agent, 0.1-1 part of leveling agent, and 0.2-0.6 parts of polycitric acid into 100 parts of solvent in sequence, and form a uniform mixed solution through magnetic stirring. Then, let it stand for 1-2 hours. The diameter of the silver nanowires is 30-50 nm, and the length is 15-30 μm. Step 2: Perform corona treatment on the transparent substrate layer through plasma. Step 3: Apply the standing solution on the surface of the corona-treated transparent substrate layer and dry it at 40-80 °C to obtain a transparent conductive thin film.

2. The preparation process of the conductive thin film according to claim 1, characterized in that: The dispersant is 2-amino-2-methyl-1-propanol, ethanolamine, or diethyl phthalate.

3. The preparation process of the conductive thin film according to claim 1, characterized in that: The leveling agent is isopropanol, propylene glycol monomethyl ether, diacetone alcohol, or ethylene glycol monobutyl ether.

4. The preparation process of the conductive thin film according to claim 1, characterized in that: The transparent substrate layer is a PET substrate layer, a PE substrate layer, a PP substrate layer, or a PI substrate layer.

5. The preparation process of the conductive thin film according to claim 1, characterized in that: The solvent is methanol, ethanol, or isopropanol.

6. The preparation process of the conductive thin film according to claim 1, characterized in that: The drying time in Step 3 is 30-60 minutes.