KR20160095236A - Silver nano wire coating solution having silver oxide, conductive coating substrate and manufacturing thereof - Google Patents

Abstract

The present invention relates to a coating liquid for silver nanowire including silver oxide, a conductive coating substrate using the same, and a production method for the coating substrate, intended to provide high conductivity, high light permeability, low haze characteristics, favorable adhesiveness, or safe environmental stability as well as dispersion stability even when silver oxide and silver nanowire are used together. To this end, the coating liquid used in conductive films includes: 0.001-1 wt% of the silver nanowire; 0.001-0.5 wt% of silver oxide; and 0.001-1 wt% of a viscosity regulating agent.

Description

TECHNICAL FIELD The present invention relates to a silver nano wire coating solution containing silver oxide, a conductive coating substrate using the same, and a silver nano wire coating solution having silver oxide,

The present invention relates to a conductive coated substrate and a method of manufacturing the same, and more particularly, to a silver nano wire coating liquid containing silver oxide, a conductive coated substrate using the same, and a method of manufacturing the same.

The coating solution containing the silver nanowire can be used as a coating solution for coating the substrate to form a conductive film. When the coating liquid is coated on the substrate, the silver nano wires form a network structure to form a conductive film. Such a conductive film can be applied to various fields such as an electrode, a transparent electrode, a surface heating element, an electrostatic shielding and absorbing agent, an electromagnetic wave shielding film, a heat dissipation material, and a sensor.

A conductive film formed of a coating solution containing a silver nano wire has a characteristic in which the silver nano wire content is increased and the haze of the conductive film is increased in order to secure a low resistance property. In this case, the coated conductive film may appear cloudy, and the pattern may be visually recognized when the pattern is formed through etching. Also, since the amount of expensive silver nano wire is increased, the manufacturing cost is also increased.

In addition, the silver nano wire coated on the substrate and connected to the network structure has different resistance characteristics depending on the interface structure between the silver nano wires, so that it has no uniformity and affects the reliability of the conductive film.

Korean Patent No. 10-1359957 (Feb.

Accordingly, it is an object of the present invention to provide a silver nano wire coating solution containing silver oxide which can form a stable dispersion phase while containing silver oxide in a silver nano wire coating solution, a conductive substrate using the silver nano wire coating solution, and a manufacturing method thereof.

Another object of the present invention is to provide a silver nano wire coating liquid containing silver oxide having low sheet resistance and low haze characteristics, a conductive substrate using the silver nano wire coating liquid, and a manufacturing method thereof.

Another object of the present invention is to provide a silver nano wire coating liquid containing silver oxide having good uniformity and environmental stability, a conductive substrate using the silver nano wire coating liquid, and a manufacturing method thereof.

In order to achieve the above object, the present invention provides a coating liquid for a conductive film, comprising 0.001 to 1 wt% of silver nanowires, 0.001 to 0.5 wt% of silver oxide, and 0.001 to 1 wt% of a viscosity adjusting agent.

In the coating liquid for a conductive film according to the present invention, the silver oxide may be AgO or Ag ₂ O.

In the coating liquid for a conductive film according to the present invention, the silver oxide may be dissolved in any one of an acid, a base and distilled water.

In the coating liquid for a conductive film according to the present invention, the viscosity adjusting agent may be selected from the group consisting of hydroxypropyl methyl cellulose, 2-hydroxy ethyl cellulose, carboxy methyl cellulose, methyl Cellulose, methyl cellulose, ethyl cellulose, and the like.

The present invention also provides a conductive coated substrate comprising a substrate and a conductive film formed on the substrate with a coating solution comprising 0.001 to 1 wt% of silver nanowires, 0.001 to 0.5 wt% of silver oxide, and 0.001 to 1 wt% to provide.

The present invention also provides a method for forming a conductive layer by applying a coating liquid containing 0.001 to 1 wt% of silver nano wire, 0.001 to 0.5 wt% of silver oxide and 0.001 to 1 wt% of a viscosity adjusting agent to a substrate to form a coating layer, The method comprising the steps of:

In the method of manufacturing a conductive coated substrate according to the present invention, the coating step may be performed by spray coating, gravure coating, micro-gravure coating, bar- coating, knife coating, reverse roll coating, roll coating, calender coating, curtain coating, extrusion coating, cast coating, such as one or more of cast coating, dip coating, air-knife coating, foam coating, and slit coating.

In the method for manufacturing a conductive coated substrate according to the present invention, the heat treatment may be photo-sintering or thermal sintering.

According to the present invention, it is possible to provide a coating liquid which forms a stable dispersion property by including silver oxide in a coating liquid containing silver nanowires and a viscosity modifier. The conductive film prepared from the coating liquid composition according to the present invention provides low sheet resistance, high light transmittance and low haze value.

In addition, according to the present invention, it is possible to reduce the content of silver nano wire including silver oxide in a silver nano wire coating solution and produce at low cost, and silver oxide contained in the coating solution can improve electric conductivity by acting as a conductive bridge between silver nano wires .

1 is a view showing a conductive coated substrate on which a conductive film is formed using a silver nano wire coating solution containing silver oxide according to the present invention.
2 is a flow chart according to the method of manufacturing the conductive coated substrate of FIG.
FIGS. 3 to 5 are tables showing the light transmittance, haze, and sheet resistance values of the conductive film depending on whether or not silver oxide (AgO, 0.02 wt%) is included according to the heat treatment temperature and time.
FIG. 6 is a table showing the light transmittance, haze, and sheet resistance of the conductive film according to the contents of silver oxide (AgO) (0.02 and 0.04% by weight) and heat treatment time.
7 is a table showing the light transmittance, haze, and sheet resistance values of the conductive film containing silver oxide (Ag2O, 0.02 wt%) according to the heat treatment time.
8 is a table showing sheet resistance and sheet resistance change rate of the conductive film depending on whether silver oxide (AgO) is contained or not.

In the following description, only parts necessary for understanding embodiments of the present invention will be described, and descriptions of other parts will be omitted to the extent that they do not disturb the gist of the present invention.

The terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary meanings and the inventor is not limited to the concept of terms in order to describe his invention as the best invention It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a conductive coated substrate on which a conductive film is formed using a silver nano wire coating solution containing silver oxide according to the present invention.

Referring to FIG. 1, a conductive coated substrate 10 according to the present invention includes a substrate 12 and a conductive film 14 formed on one side of the substrate 12.

As the substrate 12, any one of glass, quartz, glass wafer, silicon wafer, transparent and opaque plastic substrate, transparent and opaque polymer film, and metal may be used. As the material of the plastic substrate, PET, PC, PEN, PES, PMMA, PI, PEEK and the like can be used, but the present invention is not limited thereto. The substrate 12 may have a thickness of 10 to 10,000 占 퐉. Such a substrate 12 may optionally be subjected to a Piranha solution treatment, an acid treatment, a base treatment, a plasma treatment, an atmospheric plasma treatment, an ozone treatment, a UV treatment, a SAM (self assembled monolayer) The surface treatment may be performed using at least one of the following methods.

The coating liquid includes silver oxide, silver nanowires, and viscosity control agents. At this time, the coating liquid may further include a binder, a carbon nanotube, a conductive polymer, graphene, nano-carbon, and the like.

Silver nano wires having a diameter of 1 to 100 nm and a length of 2 to 100 탆 may be used. When the diameter is less than 5 nm, the mechanical stability is very weak and can be cut off. Therefore, there may be a problem that it is difficult to maintain a stable network configuration. When the diameter exceeds 100 nm, the light transmittance (light transmittance) The problem may be lowered. When the length is smaller than 2 mu m, the length of the silver wire constituting the network becomes too short, and a large number of silver nano wires are required. The transparency is lowered and the problem of deterioration of the electric conduction characteristic by many contact points Can be. When the length is longer than 100 mu m, there is a problem that the production of the silver nano wire is difficult and a problem that the silver nano wire is too long to be broken at the time of coating may occur.

The viscosity modifier is used for improving the coating property to the substrate 12 when coating liquid is coated and increasing the viscosity of the coating liquid to improve the dispersibility and the dispersion stability. Examples of the viscosity regulator include hydroxypropyl methyl cellulose, 2-hydroxy ethyl cellulose, carboxy methyl cellulose, methyl cellulose, ethyl cellulose ( ethyl cellulose), and the like.

Silver oxide is fused between the silver nanowires to serve as a conductive bridge and improve the sheet resistance. Here, silver silver oxide AgO or Ag ₂ O may be used. In the case of AgO, the effect of reducing the resistance due to thermal sintering is large in the coated conductive film. This is because the melting point of AgO is low and it melts in the thin film drying process and is favorably fused between the nanowires to advantageously reduce contact resistance between the nanowires.

The coating solution may be applied to the substrate 12 by spray coating, gravure coating, micro-gravure coating, bar-coating, knife coating, reverse coating such as reverse roll coating, roll coating, calender coating, curtain coating, extrusion coating, cast coating, dip coating, air knife Coating is performed by one or more methods of air-knife coating, foam coating, and slit coating to form a coating layer.

The conductive film 14 is formed by heat-treating a coating layer coated on the substrate 12. [ The heat treatment is sintering or heating. Sintering is photo-sintering or thermal sintering. The heating may be a combination of at least one of burn-off, micro pulse photonic heating, continuous photonic heating, microwave heating, oven heating, and furnace heating. The silver wire of the conductive film 14 coated on the substrate 12 is uniformly dispersed on one surface of the substrate 12 to form a network structure. At this time, the silver oxide contained in the conductive film 14 is positioned between the silver nano wires to serve as a conductive bridge, thereby reducing the surface resistance and stabilizing the contact resistance, thereby improving the environmental stability.

A method of manufacturing a conductive coated substrate according to the present invention will now be described with reference to FIGS. 1 and 2. FIG. 2 is a flow chart according to the method of manufacturing the conductive coated substrate of FIG.

A method for manufacturing a conductive coated substrate 10 according to the present invention includes the steps of preparing a substrate 12, applying a coating solution containing silver nano wire, silver oxide and a viscosity adjusting agent to the substrate 12 to form a coating layer (S30), and forming a conductive film by heat-treating the coating layer (S40).

First, the substrate 12 is prepared in step S20. The surface treatment for the substrate 12 can be selectively performed. As the surface treatment method of the substrate 12, at least one of a pyran solution treatment, an acid treatment, a base treatment, a plasma treatment, an atmospheric plasma treatment, an ozone treatment, a UV treatment, a SAM treatment and a polymer or monomolecular coating method is used .

Next, in step S30, a coating solution containing silver nanowires, silver oxide and a viscosity adjusting agent is applied to the substrate 12 to form a coating layer (S30). Here, the viscosity adjusting agent is included in the coating liquid to form a uniform conductive film at the time of coating while securing the dispersibility of the silver nano wire. The silver oxide is dissolved in either the acid, the distilled water or the base to be contained in the coating liquid.

The amount of the silver wire is 0.001 to 1% by weight, preferably 0.01 to 0.1% by weight. If the silver nano wire exceeds 1 wt%, the haze of the conductive film 14 becomes high and the light transmittance becomes low. When the silver wire is less than 0.001 wt%, the silver nano wire content is low, and it is difficult to form the conductive film 14 by a general commercial coating method.

The amount of silver oxide is 0.001 to 0.5% by weight, preferably 0.1 to 0.5% by weight. When the amount of silver oxide exceeds 0.5% by weight, the silver oxide concentration becomes too high, the resistance upon coating increases, and the haze increases. On the other hand, when the content is less than 0.001% by weight, there is almost no effect of decreasing the resistance due to silver oxide addition.

The amount of the viscosity controlling agent is 0.001 to 1% by weight, preferably 0.05 to 0.3% by weight. In the case of the spray coating, it is possible to coat even at the level of 0.001% by weight of the viscosity controlling agent, but in the case of other coatings, 0.05 to 0.3% by weight is suitable. When the viscosity of the coating solution is less than 0.001% by weight, the viscosity of the coating solution may be improved when the coating solution is coated on the substrate 12 to ensure uniform dispersion of the silver nanowire. It does not. If the viscosity adjusting agent exceeds 1% by weight, the adhesiveness of the conductive film 14 becomes weak and the resistance of the conductive film 14 increases.

In step S40, the coating layer applied to one side of the substrate 12 is heat-treated to form the conductive film 14. [ As the heat treatment method, it is possible to heat at a heating temperature of 100 ° C. to 150 ° C. and a heat treatment time of 1 minute to 50 minutes. Here, the silver oxide contained in the conductive film 14 is positioned between the silver nano-wires to improve the conductivity and prevent the silver nano wires from being bundled, thereby forming the conductive film 14 having a uniform thickness.

The silver nano wire coating solution containing silver oxide according to the present invention and the conductive coated substrate 10 using the same will be described in more detail with reference to Examples and Comparative Examples. Meanwhile, the silver nano wire coating solution prepared by the manufacturing method according to the present embodiment is merely one example, and the conductive film 14 manufactured by the manufacturing method and the manufacturing method according to the present invention is limited to the embodiment It is not.

Example 1 and Comparative Example 1

The conductive films according to Example 1 and Comparative Example 1 were formed in the following manner.

In the case of Example 1, it is a conductive film formed of a coating liquid containing 0.15 wt% of silver nanowire and 0.02 wt% of silver oxide (AgO) and containing 0.2 wt% of a viscosity adjusting agent (hydroxypropyl methylcellulose).

On the other hand, in the case of Comparative Example 1, it is a conductive film containing no silver oxide as a control conductive film. Here, Comparative Example 1 is a conductive film formed of a coating liquid containing 0.15 wt% of silver nanowires and 0.2 wt% of a viscosity regulator (hydroxypropyl methylcellulose).

FIG. 3 is a table comparing light transmittance, haze, and sheet resistance according to the conductive films of Example 1 and Comparative Example 1. FIG. The heat treatment temperature was 120 ° C., and the heat treatment time was 3 minutes, 10 minutes, 20 minutes, and 50 minutes, respectively.

Referring to FIG. 3, the transmittance of the conductive layer according to Example 1 shows little change in light transmittance and haze value even when the heat treatment time is increased. On the contrary, it can be seen that the sheet resistance decreases as the heat treatment time increases. The conductive film according to Example 1 shows that the sheet resistance is maintained for 20 minutes and then the sheet resistance is maintained after 20 minutes. The reason why the sheet resistance is retained after heat treatment for about 20 minutes is because silver nano wires are fused to each other through silver oxide (AgO), and contact resistance is reduced. That is, silver oxide (AgO) is fused between silver nanowires at 120 ° C for 20 minutes.

On the contrary, it can be seen that the value of the conductive film according to Comparative Example 1 increases with the heat treatment time without decreasing the sheet resistance value under the same heat treatment condition. That is, when the silver oxide is not included in the conductive film, the contact resistance between the silver nano wires is not improved under the same heat treatment condition, and the sheet resistance of the conductive film is also increased as the heat treatment time is increased.

Example 2 and Comparative Example 2

Conductive films according to Example 2 and Comparative Example 2 were formed in the following manner.

In the case of Example 2, it is a conductive film formed of a coating liquid containing 0.15 wt% of silver nanowire and 0.02 wt% of silver oxide (AgO) and containing 0.2 wt% of a viscosity adjusting agent (hydroxypropyl methylcellulose).

On the other hand, in the case of Comparative Example 2, it is a conductive film containing no silver oxide as a control conductive film. Comparative Example 2 is a conductive film formed of a coating liquid containing 0.15% by weight of silver nanowires and 0.2% by weight of a viscosity adjusting agent (hydroxypropylmethylcellulose).

4 is a chart comparing light transmittance, haze, and sheet resistance according to the conductive films of Example 2 and Comparative Example 2. The heat treatment temperature was 130 ° C. and the heat treatment time was 3 minutes, 10 minutes, 20 minutes, and 50 minutes, respectively.

Referring to FIG. 4, it can be seen that the conductive film according to Example 2 has a small change in the light transmittance and the haze value as in the conductive film according to Example 1, but the sheet resistance decreases with the heat treatment time.

Example 3 and Comparative Example 3

In Example 3, a conductive film formed of a coating solution containing 0.15 wt% of silver nanowire and 0.02 wt% of silver oxide (AgO) and containing 0.2 wt% of a viscosity controlling agent (hydroxypropyl methylcellulose) was formed.

On the other hand, in the case of Comparative Example 3, it is a conductive film containing no silver oxide as a control conductive film. Comparative Example 3 is a conductive film formed of a coating solution containing 0.15% by weight of silver nanowires and 0.2% by weight of a viscosity adjusting agent (hydroxypropylmethylcellulose).

5 is a chart comparing light transmittance, haze, and sheet resistance according to the conductive films of Example 3 and Comparative Example 3. The heat treatment temperature was 140 ° C. and the heat treatment time was 3 minutes, 10 minutes, 20 minutes, and 50 minutes, respectively.

Referring to FIG. 5, it can be seen that the sheet resistance of the conductive film according to Example 3 has the same value after 10 minutes. That is, it can be seen that the silver oxide (AgO) is melted at a temperature of 130 ° C for 10 minutes and fused between silver nano wires to lower the sheet resistance. That is, the higher the annealing temperature, the shorter the time for which the sheet resistance decreases. However, the heat treatment at high temperature not only affects the shape of the silver wire, but also may cause damage to the substrate.

Examples 4 and 5

In the case of Example 4, it is a conductive film formed of a coating liquid containing 0.15 wt% of silver nanowire and 0.04 wt% of silver oxide (AgO) and containing 0.2 wt% of a viscosity controlling agent (hydroxypropyl methylcellulose).

In Example 5, it is a conductive film formed of a coating liquid containing 0.15 wt% of silver nanowire and 0.06 wt% of silver oxide (AgO) and containing 0.2 wt% of a viscosity adjusting agent (hydroxypropyl methylcellulose).

6 is a table comparing light transmittance, haze, and sheet resistance according to the conductive films of Examples 4 and 5. The heat treatment temperature was 120 ° C., and the heat treatment time was 3 minutes, 10 minutes, 20 minutes, and 50 minutes, respectively.

Referring to FIG. 6, the conductive film according to Example 4 exhibited a resistance reduction phenomenon according to the heat treatment time. On the other hand, the coating solution according to Example 5 has a higher initial sheet resistance value and haze value as compared with the conductive film according to Example 4.

Example 6

In the case of Example 6, it is a conductive film formed of a coating liquid containing 0.15 wt% of silver nanowire and 0.02 wt% of silver oxide (Ag ₂ O) and containing 0.2 wt% of a viscosity adjusting agent (hydroxypropyl methylcellulose).

Referring to FIG. 7, it can be seen that the degree of decrease in sheet resistance is smaller in the conductive film according to the sixth embodiment than in the conductive film according to the first embodiment. This is because the melting point of Ag ₂ O is higher than that of AgO, so that the fusion of silver oxide (Ag ₂ O) does not actively occur on the silver nano wire during the heat treatment.

Example 7 and Comparative Example 4

In the case of Example 7, it is a conductive film formed of a coating solution containing 0.15 wt% of silver nanowire and 0.02 wt% of silver oxide (AgO) and containing 0.2 wt% of a viscosity adjusting agent (hydroxypropyl methylcellulose).

On the other hand, in the case of Comparative Example 4, it is a conductive film containing no silver oxide as a control conductive film. Comparative Example 4 is a conductive film formed of a coating liquid containing 0.15% by weight of silver nanowires and 0.2% by weight of a viscosity adjusting agent (hydroxypropyl methylcellulose).

8 is a table showing the rate of sheet resistance change over time while the sample is stored in a high-temperature and high-humidity environment after heat-treating the conductive film of Example 7 and Comparative Example 4 at a heat treatment temperature of 120 캜 for 20 minutes.

Referring to FIG. 8, it can be seen that the rate of change in sheet resistance after the elapse of 72 hours was as low as 30% in the conductive film according to Example 7. That is, it can be confirmed that the rate of change of sheet resistance is low because silver oxide (AgO) contained in the conductive film is fused between silver nano wires to prevent oxidation of silver nano wires and protects them from the surrounding environment.

On the other hand, the conductive film according to Comparative Example 4 was 44.9% after 72 hours.

It should be noted that the embodiments disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

10: Conductive substrate
12: substrate
14: conductive film

Claims (8)

0.001 to 1 wt% of a silver nano wire, 0.001 to 0.5 wt% of silver oxide, and 0.001 to 1 wt% of a viscosity adjusting agent. The method according to claim 1,
The silver oxide is conductive film coating liquid, characterized in that the AgO or the Ag ₂ O. The method according to claim 1,
Wherein the silver oxide is dissolved in any one of an acid, a base and distilled water. The method according to claim 1,
The viscosity modifier may be selected from the group consisting of hydroxypropyl methyl cellulose, 2-hydroxy ethyl cellulose, carboxy methyl cellulose, methyl cellulose, ethyl cellulose, cellulose, and the like. Board; And
A conductive film formed on the substrate with a coating liquid containing 0.001 to 1 wt% of silver nano wire, 0.001 to 0.5 wt% of silver oxide, and 0.001 to 1 wt% of a viscosity adjusting agent;
≪ / RTI > Applying a coating liquid containing 0.001 to 1 wt% of a silver nanowire, 0.001 to 0.5 wt% of silver oxide, and 0.001 to 1 wt% of a viscosity adjusting agent to a substrate to form a coating layer;
Heat treating the coating layer to form a conductive film;
≪ / RTI > wherein the method further comprises: 7. The method of claim 6, wherein in the applying step,
The coating solution may be applied by spray coating, gravure coating, micro-gravure coating, bar-coating, knife coating, reverse roll coating, Roll coating, calender coating, curtain coating, extrusion coating, cast coating, dip coating, air-knife coating, wherein the coating is applied to the substrate by at least one of coating, foam coating, and slit coating. The method according to claim 6, wherein in the step of forming the conductive film,
Wherein the heat treatment is photo-sintering or thermal sintering.

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