KR20190102859A - Transparent electrode coated substrate including silver nano wire and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a transparent electrode coated substrate and a method for manufacturing the same. The present invention is to maintain stable resistance properties even when exposed to an external air environment such as ultraviolet light. The present invention provides a transparent electrode coated substrate including a transparent base substrate, a transparent electrode formed on one surface of the base substrate and impregnated with silver nanowires in a protective coating layer, and a method for manufacturing the same.

Description

Transparent electrode coated substrate including silver nanowires and manufacturing method thereof

The present invention relates to a transparent electrode coated substrate and a method for manufacturing the same, and more particularly, to a transparent electrode coated substrate comprising a silver nanowire that maintains stable resistance characteristics even when exposed to an external air environment such as ultraviolet rays and a method for manufacturing the same. .

The silver nanowire transparent electrode coated substrate may form a transparent conductive substrate while having conductivity, and may be used for transparent electrodes such as displays and touch panels. In addition, the silver nanowire transparent electrode coated substrate may be used in a transparent heater, transparent electromagnetic shielding, a transparent electrode for solar cells, a transparent insulating film, and the like. In particular, the silver nanowire transparent electrode coated substrate may be applied to a transparent electrode of a bendable or foldable product because the silver nanowire transparent electrode coated substrate may provide flexibility when using a flexible plastic substrate as a base substrate.

Silver nano-wire transparent electrode coating substrate is mainly 10 ~ 50nm diameter, 1 ~ 100㎛ silver nanowires contact each other to form the electrode of the network structure. Electrodes formed of silver nanowires have a characteristic in which conductivity varies greatly depending on the shape of the silver nanowires themselves and the connectivity between them. Since silver nanowires are very thin, mainly 10-50 nm in diameter, they can be oxidized, degraded, or broken by the outside environment. As a result, the resistance of the transparent electrode is increased.

 Therefore, in order to apply silver nanowire transparent electrode coated substrate to application products such as display, touch panel, transparent heater, transparent electromagnetic shielding, solar cell, etc. Stability must be secured.

In order to secure such environmental stability, a protective coating layer was formed when manufacturing a silver nanowire transparent electrode coated substrate. For example, after the silver nanowires are coated on the base substrate, the protective coating layer is formed by overcoating the protective coating agent thereon.

 This conventional method can simply produce a highly reliable silver nanowire transparent electrode coated substrate, but may have problems depending on the application. For example, in the transparent electrode coated substrate having the structure of the base substrate / silver nanowire layer / protective coating layer, since the protective coating layer is formed on the silver nanowire layer, only one surface of the silver nanowire layer contacts the protective coating layer, and the silver nanowire in contact with the base substrate. The layer is not in contact with the protective coating layer. That is, since the ultraviolet light flowing from the base substrate direction is directly irradiated directly onto the silver nanowire layer without passing through the protective coating layer, the silver nanowire layer is very susceptible to degradation due to ultraviolet rays even when the protective coating layer is formed.

The base substrate used for the silver nanowire transparent electrode coating substrate may be a polymer film such as PET (polyethylene terephthalate), PI (polyimide), PC (polycarbonate) or glass. The material of the base substrate has a high UV transmittance, and the ultraviolet rays flowing in the base substrate direction greatly deteriorate the transparent electrode characteristics.

Registered Patent Publication No. 10-1693486 (January 02, 2017)

Accordingly, it is an object of the present invention to provide a transparent electrode coated substrate including silver nanowires capable of maintaining environmental stability even when the silver nanowire transparent electrode coated substrate is exposed to an external environment, and a method of manufacturing the same.

In order to achieve the above object, the present invention comprises the steps of over-coating a protective coating liquid containing a protective coating agent on a transparent base substrate to form a protective coating layer; And coating a silver nanowire dispersion on the protective coating layer to form a silver nanowire layer. The method of manufacturing a transparent electrode coated substrate including silver nanowires includes;

The protective coating agent is an epoxy, polyvinylphenol, polymethylmethacrylate, polyurethane, polyacrylate or polyvinylphenol / polymethylmethacrylate copolymer.

The protective coating agent is hydroxypropylmethylcellulose, ethylcellulose or 2-hydroxyethylcellulose.

The manufacturing method according to the present invention may further include impregnating the silver nanowire layer in the protective coating layer through heat treatment, which is performed after forming the silver nanowire layer.

Heat treatment in the impregnation step is carried out at 70 to 150 ℃.

The present invention also provides a transparent base substrate; And a transparent electrode formed on one surface of the base substrate, wherein the protective coating layer is impregnated with silver nanowires.

The transparent electrode coating substrate according to the present invention may further include a deterioration inhibitor added to the transparent electrode.

The deterioration inhibitors include benzotriazole, tolytriazole, butyl benzyl triazole, dithiothiadiazole, alkyl dithiothiadiazoles, and alkyl dithiothiadiazoles. and alkylthiols), 2-amino-5-mercapto-1, 3,4-thiadiazole, 2-mercaptopyrimidine (2 -mercaptopyrimidine), 2-mercaptobenzoxazole, 5-amino-1,3,4, thiadiazol-2-thiol (5-amino-1,3,4 ?? thiadiazole-2-thiol ), benzothiazole), 2-aminopyrimidine, 5,6-dimethylbenzimidazole or 2-mercaptobenzimidazole.

According to the present invention, since the protective coating layer is formed between the base substrate and the silver nanowire layer, it is possible to maintain environmental stability such as stable resistance characteristics even when exposed to an external air environment such as ultraviolet rays flowing from the base substrate to the silver nanowire layer.

Since the protective coating layer according to the present invention contains a deterioration inhibitor, it is possible to more effectively suppress the deterioration of the silver nanowire layer by ultraviolet rays.

By impregnating the silver nanowire layer on the protective coating layer through heat treatment, it is possible to maintain environmental stability such as stable resistance characteristics even when exposed to an external air environment such as ultraviolet rays flowing in both the upper and rear surfaces of the transparent electrode coating substrate.

1 is a cross-sectional view illustrating a transparent electrode coated substrate including silver nanowires according to a first embodiment of the present invention.
2 is a flowchart illustrating a method of manufacturing a transparent electrode coated substrate including silver nanowires according to a first embodiment of the present invention.
3 and 4 illustrate each step according to the manufacturing method of FIG. 2.
5 is a cross-sectional view illustrating a transparent electrode coated substrate including silver nanowires according to a second embodiment of the present invention.
6 is a flowchart illustrating a method of manufacturing a transparent electrode coated substrate including silver nanowires according to a second embodiment of the present invention.
7 to 9 are views showing each step according to the manufacturing method of FIG.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, it should be noted that the description of other parts will be omitted in a range that does not distract from the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and the inventors are appropriate to the concept of terms in order to explain their invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be variations and variations.

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

[First Embodiment]

1 is a cross-sectional view illustrating a transparent electrode coated substrate including silver nanowires according to a first embodiment of the present invention.

Referring to FIG. 1, the transparent electrode coating substrate 10 according to the first embodiment includes a base substrate 11, a protective coating layer 13, and a silver nanowire layer 15. The protective coating layer 13 is formed by overcoating on one surface of the base substrate 11. The silver nanowire layer 15 is formed by coating the silver nanowire dispersion on the protective coating layer 13. Here, the silver nanowire layer 15 is used as a transparent electrode. In the silver nanowire layer 15, the silver nanowires 17 form a network structure to exhibit electrical conductivity.

As described above, since the protective coating layer 13 is formed between the base substrate 11 and the silver nanowire layer 15 in the transparent electrode coating substrate 10 according to the first embodiment, the silver nanowire layer may be formed in the base substrate 11. When exposed to an external air environment such as ultraviolet rays introduced into 15), it is possible to maintain environmental stability such as stable resistance characteristics of the silver nanowire layer 15.

The base substrate 11 is made of a transparent material. For example, a polymer film or glass such as PET, PI, PC, PEN (polyethylene naphthalate), PES (polyethersulfone), or the like may be used as the material of the base substrate 11.

The protective coating layer 13 is formed by overcoating a protective coating solution containing a protective coating agent on one surface of the base substrate 11. As the protective coating agent, epoxy, polyvinylphenol, polymethyl methacrylate, polyurethane, polyacrylate, polyvinylphenol / polymethyl methacrylate copolymer, or the like may be used. As a protective coating solution, 0.1 to 3 wt% solution based on solids is used. The thickness of the protective coating layer is 10 ~ 3000nm level.

The protective coating solution may further include a deterioration inhibitor in order to more effectively suppress deterioration of the silver nanowire layer 15 by ultraviolet rays. Degradation inhibitors include benzotriazole, tolytriazole, butyl benzyl triazole, dithiothiadiazole, alkyl dithiothiadiazoles and alkyl dithiothiadiazoles. and alkylthiols), 2-amino-5-mercapto-1, 3,4-thiadiazole, 2-mercaptopyrimidine (2 -mercaptopyrimidine), 2-mercaptobenzoxazole, 5-amino-1,3,4, thiadiazol-2-thiol (5-amino-1,3,4 ?? thiadiazole-2-thiol ), benzothiazole), 2-aminopyrimidine, 5, 6-dimethylbenzimidazole, 2-mercaptobenzimidazole and the like can be used. Degradation agent concentration in the protective coating solution is 0.0001 ~ 0.1%. The overcoating process may be applied by spray coating, microgravure coating, slot die coating, spin coating, casting, dip coating, etc., and is dried by heat treatment at 70 to 150 ° C. after coating.

The silver nanowire layer 15 is formed by coating the silver nanowire dispersion and then drying it. The silver nanowire dispersion includes 0.05 to 0.5 wt% based on the silver nanowire solid content. As the coating method of the silver nanowire dispersion, spray coating, microgravure coating, slot die coating, spin coating, casting, dip coating, or the like may be used. The silver nanowire layer has a sheet resistance of 5 to 500 Ω / sq. The silver nanowire dispersion may be added with additives such as a dispersing agent and viscosity control in addition to the silver nanowire.

The method of manufacturing the transparent electrode coated substrate 10 according to the first embodiment will be described with reference to FIGS. 1 to 4 as follows. 2 is a flowchart of a method of manufacturing a transparent electrode coated substrate 10 including silver nanowires 17 according to a first embodiment of the present invention. 3 and 4 illustrate each step according to the manufacturing method of FIG. 2.

First, as shown in FIG. 3, the base substrate 11 is prepared in step S21.

Next, as shown in FIG. 4, the protective coating layer 13 is formed by overcoating one surface of the base substrate 11 in step S23.

As shown in FIG. 1, in operation S25, the silver nanowire layer 15 is formed by coating the silver nanowire dispersion solution on the protective coating layer 13 to form a silver nanowire layer 17 according to the first embodiment. The coated substrate 10 may be manufactured.

At this time, the silver nanowire dispersion is coated and dried by heat treatment at 70 ~ 150 ℃ to form a silver nanowire layer (15). At this time, even after performing the heat treatment at 70 ~ 150 ℃ after coating the silver nano-wire layer 15, impregnation of the silver nano-wire layer 15 into the protective coating layer 13 is hardly progressed.

If the heat treatment of step S25 is performed at less than 70 ℃, it may take more time to dry the silver nanowire layer 15. On the contrary, when the heat treatment is performed in excess of 150 ° C., a part of the silver nanowires 17 may be melted to break the network structure of the silver nanowires 17.

Second Embodiment

5 is a cross-sectional view illustrating a transparent electrode coating substrate 30 including a silver nanowire 37 according to a second embodiment of the present invention.

Referring to FIG. 5, the transparent electrode coating substrate 30 according to the second embodiment includes a base substrate 31 and a transparent electrode 39. The transparent electrode 39 is formed on one surface of the base substrate 31, and the silver nanowires 37 are impregnated in the protective coating layer 33.

As described above, since the transparent electrode coating substrate 30 according to the second embodiment has a structure in which the silver nanowires 37 are impregnated in the protective coating layer 33 formed by the protective coating agent, the upper surface and the rear surface of the base substrate 31 are formed. Even when exposed to an external environment such as ultraviolet light flowing in both directions, the transparent electrode 39 may maintain environmental stability such as stable resistance characteristics.

A method of manufacturing the transparent electrode coated substrate 30 according to the second embodiment will be described with reference to FIGS. 5 to 9 as follows. 6 is a flowchart illustrating a method of manufacturing a transparent electrode coated substrate 30 including silver nanowires 37 according to a second embodiment of the present invention. 7 to 9 are views showing each step according to the manufacturing method of FIG.

First, as shown in FIG. 7, the base substrate 31 is prepared in step S41. Here, the base substrate 31 is made of a transparent material. For example, a polymer film such as PET, PI, PC, PEN, PES or glass may be used as the material of the base substrate 31.

Next, as shown in FIG. 8, the protective coating layer 33 is formed on one surface of the base substrate 31 by overcoating in step S43.

The protective coating layer 33 is formed by overcoating a protective coating solution containing a protective coating agent on one surface of the base substrate 31. As the protective coating agent, hydroxypropyl methyl cellulose, ethyl cellulose, 2-hydroxyethyl cellulose and the like can be used.

The protective coating solution uses a solution of 0.1 ~ 3wt% based on solids. The thickness of the protective coating layer 33 is 50 ~ 5000nm level.

In this case, the protective coating solution may further include a deterioration inhibitor to more effectively suppress deterioration of the silver nanowires 37 by ultraviolet rays. As the degradation inhibitor, at least one of the degradation inhibitors according to the first embodiment may be used. Degradation agent concentration in the protective coating solution is 0.0001 ~ 0.1%. The overcoating process may be applied by spray coating, microgravure coating, slot die coating, spin coating, casting, dip coating, etc., and is dried by heat treatment at 70 to 150 ° C. after coating.

Next, as shown in FIG. 9, the silver nanowire dispersion is coated on the protective coating layer 33 in step S45 to form the silver nanowire layer 35.

The silver nanowire layer 35 is formed by coating a silver nanowire dispersion and then drying it. The silver nanowire dispersion includes 0.05 to 0.5 wt% based on the silver nanowire solid content. As the coating method of the silver nanowire dispersion, spray coating, microgravure coating, slot die coating, spin coating, casting, dip coating, or the like may be used. The silver nanowire layer 35 has a sheet resistance of 5 to 500 Ω / sq. The silver nanowire dispersion may be added with additives such as a dispersant and a viscosity control in addition to the silver nanowire 37.

As shown in FIG. 6, the transparent electrode including the silver nanowires 37 according to the second embodiment is impregnated by impregnating the silver nanowire layer 35 (FIG. 5) to the protective coating layer 33 through heat treatment in step S47. The coated substrate 30 may be manufactured.

When the silver nanowire layer 35 of FIG. 5 is coated and heat treated at 70 to 150 ° C., as shown in FIG. 6, the silver nanowire 37 is impregnated into the protective coating layer 33 to form a transparent electrode 39. do. That is, the transparent electrode 39 is formed by merging a silver nanowire layer (35 in FIG. 5) on a protective coating layer 33.

If the heat treatment of step S47 is carried out below 70 ℃, impregnation of the silver nanowire layer to the protective coating layer hardly occurs. On the contrary, when the heat treatment is performed in excess of 150 ° C., a part of the silver nano wire may be melted to break the network structure of the silver nano wire.

The environmental stability was confirmed by measuring the resistance change according to the ultraviolet irradiation of the transparent electrode coating substrate according to the first and second embodiments. The transparent electrode coating substrate according to the comparative example has a structure in which a base substrate / silver nanowire layer / protective coating layer is formed by coating a silver nanowire on a base substrate and then forming a protective coating thereon.

The resistance change was measured after exposing ultraviolet rays (1 W / cm ² , 72 hours) in the base substrate direction and the opposite direction of the base substrate, respectively.

First, when ultraviolet rays were exposed in the base film direction, a resistance change rate of 5.2% for the first example, 5.8% for the second example, and 32% for the comparative example was measured.

Next, when ultraviolet rays were exposed in the opposite direction to the base substrate, a resistance change rate of 26% in the first example, 6.5% in the second example, and 4.2% in the comparative example was measured.

As described above, in the case of the first and second embodiments, the resistance change rate was lower when the ultraviolet rays were exposed in the direction of the base substrate. Further, in the second embodiment, the resistance change rate against UV exposure was lowest in both directions of the base substrate.

On the other hand, the embodiments disclosed in the specification and drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

11, 31: base substrate
13, 33: protective coating layer
15, 35: silver nano wire layer
17, 37: silver nano wire
39: transparent electrode
10, 30: transparent electrode coating substrate

Claims (8)

Forming a protective coating layer by overcoating a protective coating liquid containing a protective coating agent on a transparent base substrate; And
Coating a silver nanowire dispersion on the protective coating layer to form a silver nanowire layer;
Method of manufacturing a transparent electrode coated substrate comprising a silver nanowire comprising a. The method of claim 1,
The protective coating agent is an epoxy, polyvinyl phenol, polymethyl methacrylate, polyurethane, polyacrylate or polyvinyl phenol / polymethyl methacrylate copolymer for the production of a transparent electrode coating substrate comprising a silver nano-wire, characterized in that Way. The method of claim 1,
The protective coating agent is a hydroxypropyl methyl cellulose, ethyl cellulose or 2-hydroxyethyl cellulose manufacturing method of a transparent electrode coated substrate comprising a silver nano-wire, characterized in that. According to claim 3, After the step of forming the silver nanowire layer,
Impregnating the silver nanowire layer on the protective coating layer through heat treatment;
Method of manufacturing a transparent electrode coated substrate comprising a silver nanowire further comprising. The method of claim 4, wherein
In the impregnating step, the heat treatment is a method of manufacturing a transparent electrode coated substrate comprising silver nanowires, characterized in that performed at 70 to 150 ℃. A transparent base substrate; And
A transparent electrode formed on one surface of the base substrate and having silver nanowires impregnated in the protective coating layer;
Transparent electrode coating substrate comprising a silver nanowire comprising a. The method of claim 6,
The protective coating agent is a hydroxypropyl methyl cellulose, ethyl cellulose or 2-hydroxyethyl cellulose transparent electrode coating substrate comprising a silver nano-wire, characterized in that. The method of claim 7, wherein
Further comprising; a deterioration inhibitor added to the transparent electrode,
The deterioration inhibitors include benzotriazole, tolytriazole, butyl benzyl triazole, dithiothiadiazole, alkyl dithiothiadiazoles, and alkyl dithiothiadiazoles. and alkylthiols), 2-amino-5-mercapto-1, 3,4-thiadiazole, 2-mercaptopyrimidine (2 -mercaptopyrimidine), 2-mercaptobenzoxazole, 5-amino-1,3,4, thiadiazol-2-thiol (5-amino-1,3,4 ?? thiadiazole-2-thiol ), benzothiazole), 2-aminopyrimidine, 5,6-dimethylbenzimidazole or 2-mercaptobenzimidazole. Transparent electrode coating substrate comprising a wire.

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