WO2018040953A1

WO2018040953A1 - Method for preparing nano silver wire transparent conductive film based on hydrophilically modified pet substrate

Info

Publication number: WO2018040953A1
Application number: PCT/CN2017/098058
Authority: WO
Inventors: 段镶锋; 段曦东; 李晓丰; 毛志浩
Original assignee: 广东纳路纳米科技有限公司
Priority date: 2016-08-29
Filing date: 2017-08-18
Publication date: 2018-03-08
Also published as: CN106298071B; CN106298071A

Abstract

Disclosed is a method for preparing a nano silver wire transparent conductive film based on a hydrophilically modified PET substrate, relating to the technical field of flexible transparent conductive thin films. The preparation method comprises: selecting an optical-grade coated PET substrate which is subjected to double-sided layer hardening, and washing same with an ethanol/acetone mixed solvent to remove impurities; performing hydrophilic modification on the PET substrate by a low-temperature argon/oxygen hybrid plasma technology after drying, wherein the plasma discharge power is 10-150 W, and the processing time is 6-900 seconds; and uniformly and densely applying a nano silver wire ethanol dispersion liquid of a concentration of 0.01-10 mg/ml on a surface of the hydrophilically modified PET substrate by a precision coating method, and performing baking for 10-120 minutes at 60-200ºC to prepare the transparent conductive thin film. The nano silver wire transparent conductive thin film based on the hydrophilically modified PET substrate has a high transmittance, high conductivity and a good adhesive force, as well as good flexural resistance and a bright application prospect.

Description

[Invention name established by ISA according to Rule 37.2] Method for preparing nano silver wire transparent conductive film based on hydrophilic modified PET substrate

Technical field

The invention relates to the technical field of flexible transparent conductive films, in particular to a preparation based on a hydrophilic modified PET substrate/nano-silver transparent conductive film.

Background technique

The transparent conductive film is a film which has both conductivity and high light transmittance, and is widely used in the field of electronic components such as liquid crystal displays, touch panels and solar cells. With the popularization of products such as mobile terminals, wearable devices, and smart home appliances in the future, touch panels are becoming larger and lower in price. The traditional ITO (indium tin oxide) transparent conductive film is expensive due to the scarcity of raw materials and is itself toxic; the magnetron sputtering process has higher production cost, large impedance change, and the ITO material is brittle, and the prepared conductive film cannot be bent. The cost difference is 50% compared to graphene, metal grids, and nanosilver lines, which symbolize future printing technologies.

So far, graphene is still in the research and development stage, and there is still a long way to go from mass production. Among the various new materials, the development of nano silver wire and metal mesh is relatively mature. Although both metal mesh and nano silver wire have the advantages of better conductivity and lower price than ITO, as of now, metal mesh still has opacity, high reflection, Murray interference, and relatively weak folding, mold Expensive and urgent problems to be solved. Therefore, nano-silver wire technology is not available in metal networks in terms of material flexibility and light transmittance.

The nano silver wire technology is to prepare a nano silver wire conductive film by a coating process, and the metal mesh needs to make a film, press the film out of the line, and then fill the micron-sized silver particles. The micron-sized silver particles are thicker than the nano-scale silver wires, and the conductivity is better, but the disadvantages are also outstanding. The silver particles are large, the visibility is strong, and the particles can be seen under the light and the strong light. The material is micron-sized, brittle and easy to break, and is not easy to use as a flexible screen. Since the nano silver wire is formed into a transparent conductive film having a nano-scale silver wire conductive network pattern by laser lithography, the line width of the nano silver wire is very small. It is about 50 nm, much smaller than 1 um, so there is no problem of Murray interference, and it can be applied to display screens of different sizes. Compared with the metal grid, the nano-silver wire conductive film has a higher light transmittance due to a smaller line width, and has a smaller bending radius, and has a smaller rate of change in resistance during bending, and can be applied to a flexible curved display device. It is most likely to replace traditional ITO materials. However, in the prior art, there are still deficiencies, such as uneven distribution of the nano silver wire in the transparent conductive film, and the hydrophobicity and antistatic property of the PET surface are not strong, resulting in poor conductivity and adhesion of the nano silver wire film.

Summary of the invention

In view of the above, it is necessary to provide a method for preparing a hydrophilic modified PET substrate/nano-silver transparent conductive film based on the above problems.

To achieve the above object, the present invention adopts the following technical solutions:

The invention is based on the preparation of a hydrophilic modified PET substrate/nano-silver transparent conductive film, comprising:

Hydrophilic modification of PET substrate surface and preparation of nano silver wire transparent conductive film;

The hydrophilic modification of the surface of the PET substrate comprises: selecting an optical grade coated PET substrate treated by a double-sided hardened layer, cleaning and removing impurities by using an ethanol/acetone mixed solvent; and drying the low-temperature argon/oxygen mixed plasma technique The PET substrate is hydrophilically modified, the plasma discharge power is 10-150 W, and the treatment time is 6-900 s;

The preparation of the nano silver wire transparent conductive film comprises: uniformly coating a nano silver wire ethanol dispersion having a concentration of 0.01-10 mg/ml on the surface of the hydrophilic modified PET substrate by precise coating. A transparent conductive film is prepared after baking at 60-200 ° C for 10-120 min.

Preferably, the plasma discharge power is 100 W and the treatment time is 6-600 s.

Preferably, the nanosilver ethanol dispersion has a concentration of from 0.01 to 5 mg/ml.

Preferably, the baking time is 10-90 min and the temperature is 60-150 °C.

Preferably, the PET substrate has a thickness of 50 um, 100 um or 125 um.

Preferably, the ethanol/acetone volume ratio is one.

Preferably, the precision coating is a micro gravure coating method.

The nano silver wire transparent conductive film prepared by the invention has a thickness of 50-600 nm, preferably 50-300 nm.

Compared with the existing nano silver wire transparent conductive film technology, the beneficial effects of the present invention are:

After hydrophilic modification of the surface of the PET substrate by low-temperature argon/oxygen mixed plasma, more oxygen-containing active groups such as carboxyl groups and carbonyl groups are generated on the surface of the PET substrate, which lowers the contact angle of the surface of the PET substrate. The water solubility is greatly improved, so that the nano silver wire ethanol dispersion is better dispersed and attached to the PET substrate, thereby improving the adhesion between the nano silver wire and the PET substrate;

The nano silver wire dispersion is uniformly and densely coated on the surface of the PET substrate by micro gravure coating. After baking at the oven temperature, the ethanol solvent is quickly evaporated completely, and the nano silver wire film formed in the entire PET substrate region is formed. The thickness and film formation uniformity are relatively uniform, the formed film is more dense, the mutual contact between the nano silver wires is more compact, and the electrical conductivity is also improved.

The nano silver wire transparent conductive film prepared by the invention has high transmittance, strong conductivity, good adhesion, good flexural resistance and high application prospect.

detailed description

In order to make the objects, the technical solutions and the advantages of the present invention more clearly, the technical solutions of the present invention will be further clearly and completely described below in conjunction with the embodiments of the present invention. It should be noted that the described embodiments are only a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Example 1

Step 1) Hydrophilic modification of the surface of the PET substrate: firstly, a 100 um optical grade double-sided hardened PET substrate with a protective film is washed with a mixed solvent of ethanol/acetone volume ratio of 1, and vacuum dried at 80 ° C, and then used. The surface of the PET substrate was subjected to discharge treatment under a low temperature argon/oxygen mixed plasma, and the discharge power was 100 W, and the hydrophilic modified PET substrate was obtained after 60 s of treatment time;

Step 2) Preparation of a nano silver wire transparent conductive film: a 0.6 mg/ml nano silver wire ethanol dispersion is precisely applied to the surface of the hydrophilic modified PET substrate obtained in the step 1) by micro gravure coating. After baking at a temperature of 90 ° C for 60 min, a PET substrate/nano-silver transparent conductive film having a thickness of 50 nm was obtained.

Example 2

Step 1) Hydrophilic modification of the surface of the PET substrate: firstly, a 100 um optical grade double-sided hardened PET substrate with a protective film is washed with a mixed solvent of ethanol/acetone volume ratio of 1, and vacuum dried at 80 ° C, and then used. The surface of the PET substrate was subjected to discharge treatment under a low temperature argon/oxygen mixed plasma, and the discharge power was 100 W, and the hydrophilic modified PET substrate was obtained after the treatment time was 180 s;

Example 3

Step 1) Hydrophilic modification of the surface of the PET substrate: firstly, a 100 um optical grade double-sided hardened PET substrate with a protective film is washed with a mixed solvent of ethanol/acetone volume ratio of 1, and vacuum dried at 80 ° C, and then used. The surface of the PET substrate was subjected to discharge treatment under a low temperature argon/oxygen mixed plasma, and the discharge power was 100 W, and the hydrophilic modified PET substrate was obtained after the treatment time was 300 s;

Example 4

Step 2) Preparation of nano silver wire transparent conductive film: 1 mg/ml nano silver wire ethanol dispersion is precisely applied to the surface of the hydrophilic modified PET substrate obtained in step 1) by micro gravure coating. After baking at a temperature of 120 ° C for 30 min, a PET substrate/nano-silver transparent conductive film having a thickness of 70 nm was obtained.

Example 5

Example 6

Step 2) Preparation of nano silver wire transparent conductive film: 3 mg/ml nano silver wire ethanol dispersion is precisely applied to the surface of the hydrophilic modified PET substrate obtained in step 1) by micro gravure coating method. After baking at a temperature of 120 ° C for 30 min, a PET substrate/nano-silver transparent conductive film having a thickness of 70 nm was obtained.

Comparative Example 1

Step 1) Dedusting the surface of the PET substrate: firstly, the 100 um optical grade double-sided hardened PET substrate is cleaned and dusted with a mixed solvent of ethanol/acetone volume ratio of 1, and dried at 80 ° C to obtain a clean PET substrate;

Step 2) Preparation of a nano silver wire transparent conductive film: 0.6 mg/ml using a micro gravure coating method The nano silver wire ethanol dispersion is precisely coated on the surface of the clean PET substrate, and baked at a temperature of 90 ° C for 60 min to obtain a 45 nm thick nano-silver transparent conductive film.

Comparative Example 2

Step 2) Preparation of nano silver wire transparent conductive film: 1 mg/ml nano silver wire ethanol dispersion is precisely coated on the surface cleaned PET substrate by micro gravure coating method, and dried at a temperature of 120 ° C. After baking for 30 minutes, a nano-silver transparent conductive film having a thickness of 60 nm was obtained.

Table 1 shows the performance indexes of the nano silver wire transparent conductive film of each example:

Table 1 Performance of nano silver wire transparent conductive film in each example

As can be seen from the above Table 1, the hydrophilic modified nano-silver transparent conductive film of the PET substrate of the present invention has high transmittance, strong conductivity, good adhesion, and good flexural resistance, and has great application prospects. .

The above described embodiments merely express several embodiments of the present invention, and the description thereof is more specific and detailed. However, it is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

The invention relates to a preparation of a hydrophilic modified PET substrate/nano-silver transparent conductive film, which comprises: hydrophilic modification of a PET substrate surface and preparation of a nano silver wire transparent conductive film;

The hydrophilic modification of the surface of the PET substrate comprises: selecting an optical grade coated PET substrate treated by a double-sided hardened layer, cleaning and removing impurities by using an ethanol/acetone mixed solvent; and drying the low-temperature argon/oxygen mixed plasma technique The PET substrate is hydrophilically modified, the plasma discharge power is 10-150 W, and the treatment time is 6-900 s;

The preparation of the nano silver wire transparent conductive film comprises: uniformly coating a nano silver wire ethanol dispersion having a concentration of 0.01-10 mg/ml on the surface of the hydrophilic modified PET substrate by precise coating. A transparent conductive film is prepared after baking at 60-200 ° C for 10-120 min.
The preparation of a hydrophilic modified PET substrate/nano-silver transparent conductive film according to claim 1, wherein the plasma discharge power is 100 W and the treatment time is 6-600 s.
The preparation of the hydrophilic modified PET substrate/nano-silver transparent conductive film according to claim 1, wherein the nano silver wire ethanol dispersion has a concentration of 0.01-5 mg/ml.
The preparation of a hydrophilic modified PET substrate/nanosilver transparent conductive film according to claim 1, wherein the baking time is 10-90 min and the temperature is 60-150 °C.
The preparation of a hydrophilic modified PET substrate/nanosilver transparent conductive film according to any one of claims 1 to 4, wherein the PET substrate has a thickness of 50 um, 100 um or 125 um.
The preparation of a hydrophilic modified PET substrate/nanosilver transparent conductive film according to any one of claims 1 to 4, wherein the ethanol/acetone volume ratio is 1.
The preparation of a hydrophilic modified PET substrate/nanosilver transparent conductive film according to claim 1, wherein the precision coating is a micro gravure coating method.