KR20160037299A - Transparent conductive film with improved visibility - Google Patents

Abstract

The present invention relates to a transparent conductive film with improved visibility which comprises the following steps of: manufacturing a coating solution by mixing a metal nano wire of which an average diameter is 20 nm or smaller and a length is 20 μm or longer; and coating at least one surface of a plastic base material layer with the manufactured coating solution and hardening the coating solution to form a transparent conductive film. According to the present invention, the transparent conductive film drastically improves visibility and drastically simplifies manufacturing processes to be easily applied to a touch panel of a large capacity and the like.

Description

[0001] Transparent conductive film with improved visibility [

The present invention relates to a transparent conductive film, and more particularly, to a transparent conductive film which can realize a fine electrode pattern by coating a plastic substrate with a metal wire coating solution having a diameter of 20 nm or less, and improving visibility.

As the information society has progressed, touch panels have recently attracted attention.

In such a touch panel, an example in which the electrodes are made of indium tin oxide (ITO) is disclosed in order to prevent the electrodes arranged in the matrix from being conspicuous.

The touch panel is mainly applied to a small size such as a PDA (portable information terminal) or a mobile phone. However, as the application to a PC display or the like becomes more generalized, the size of the touch panel is expected to increase.

However, since ITO has a surface resistance of 300 OMEGA / sq, the application size of the ITO increases, so that the transfer speed of the current between the electrodes becomes slower and the response speed (the time from the contact of the fingertip to the detection of the position) there is a problem.

Japanese Unexamined Patent Publication No. 2010-108878 discloses a conductive film having a conductive layer containing silver formed by exposing and developing a silver chloride emulsion layer on a support, wherein an example of forming a conductive layer with a mesh pattern having a pitch of 600 占 퐉 or more .

When a metal material having excellent electrical conductivity is used as an electrically conductive material as in the above silver, there is an advantage that it can be used in a large-capacity touch panel by reducing electrical resistance. However, when the diameter is 30 nm or more, haze is increased due to light scattering, There is a problem that the visibility is remarkably reduced due to the reflection by the light.

Japanese Laid-Open Patent Publication No. 2010-108878

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It is an object of the present invention to provide a transparent conductive film which is capable of forming a fine pattern by coating a plastic substrate with a metal wire coating solution having a diameter of 20 nm or less and improving visibility.

Another object of the present invention is to provide a transparent conductive film capable of preventing a phenomenon in which visibility is significantly reduced due to light emitted from the outside due to high haze due to light scattering.

In order to solve the above problems,

Preparing a coating liquid by mixing metal nanowires having an average diameter of 20 nm or less and a length of 20 m or more in an adhesive resin;

A coating solution is coated on at least one surface of a plastic film substrate layer and then cured to provide a transparent conductive film.

Wherein the metal nanowires are selected from Au, Ag, Cu, Pt, and Ni.

In order to solve the above-mentioned problems, the present invention further provides a fluorine-based surfactant and a cellulose-based binder in an amount of 0.0005 to 0.05% by weight and 0.005 to 0.1% by weight, respectively, As a means for solving the problems.

The transparent conductive film of the present invention is free from the phenomenon that the haze of the transparent conductive film is increased by scattering due to light or reflected by the light incident from the outside, and the metallic wire coating solution is prepared and coated on the plastic substrate. It can be easily applied to a large-capacity touch panel.

1 is a photograph showing the visibility of a transparent conductive film obtained by patterning a metal nanowire having a diameter of 20 nm or less.
2 is a photograph showing the visibility of a transparent conductive film obtained by patterning metal nanowires having a diameter of 30 nm or more.

It will be apparent to those of ordinary skill in the art that the present invention may be more readily understood and carried out without undue experimentation.

In describing the present invention, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

To achieve the above object, a coating liquid made of an adhesive resin is introduced onto at least one surface of a plastic film base layer. The coating solution is characterized by containing Au, Ag, Cu, Pt, and Ni having an average diameter of 20 nm or less and a length of 20 m or more.

And the surface of the metal nanowire is surrounded by the surface of the nanowire with a thickness of 0.1 to 2 nm by PVP or PVA.

When the coating solution is applied to the surface of the film, the fluorine-based surfactant and the cellulose-based binder are added in an amount of 0.0005 to 0.05 wt% and 0.005 to 0.1 wt%, respectively, relative to the total weight of the coating solution, in order to improve the wettability of the base film and uniformly apply the coating solution. .

The amount of the metal nanowires contained in the coating liquid is preferably adjusted within 30 to 70 wt%, more preferably 40 to 60 wt%, based on the solid content of the final coating layer. If the content of the metal oxide fine particles in the coating layer is less than 30 wt%, continuous connection of the metal oxide compound is not achieved due to the coating resin matrix, so that the conductive / electroconductive property is not exhibited. Conversely, if the content exceeds 70 wt% If it is not economically preferable, and if the content is too large, there arises a problem that a flexible property such as a crack is generated on the surface.

The prepared coating liquid exhibits a viscosity of 2 to 5 cP and a surface energy of 20 to 30 dyne / cm ² .

The transparent conductive film according to the present invention has a haze value of less than 1.8 including a substrate, an electrical resistance of 60 OMEGA / sq or less, and a transparency of 90% or more. At this time, when the haze value after coating exceeds the above value, it can not serve as a transparent film. If the electric resistance exceeds 60? / Sq, the electric conductivity becomes poor and it becomes difficult to use as a conductive film.

In the present invention, the coating method is not particularly limited, and various coating methods such as gravure roll, reverse roll, reverse gravure, and Mayer bar may be employed.

The transparent conductive film having excellent conductivity produced through the above coating process has excellent electrical conductivity while maintaining transparency as compared with a general film not having a conductive coating.

Hereinafter, the present invention will be described in more detail with reference to examples. However, it should be understood that the following examples are provided only for the understanding of the present invention, and the present invention is not limited to these examples.

[Example]

The water-dispersed PVP and water-dispersed Ag nanoparticles (diameter 20 nm, length 35 μm) were mixed at a ratio of 70:30 on the basis of the solid content to prepare a coating liquid. Then, the fluorine-based surfactant and the cellulose- By weight, and then the mixture was uniformly dispersed using a stirrer and coated on one side of the polyester film to a thickness of 2 nm using a Mayer bar coater.

[Comparative Example]

Except that Ag nanoparticles having a diameter of 30 nm were used.

The visibility of the transparent conductive film produced by the above Examples and Comparative Examples is shown in FIG. 1 and FIG. As shown in FIG. 1, the visibility is much improved compared to FIG. It was confirmed that the microelectrode pattern can be realized and the visibility can be improved when the diameter of the metal nanowire is 20 nm or less.

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Claims (4)

Preparing a coating liquid by mixing metal nanowires having an average diameter of 20 nm or less and a length of 20 m or more in an adhesive resin;
A method of coating the above prepared coating liquid on at least one surface of a plastic film base layer and curing it to prepare a transparent conductive film The method according to claim 1,
Wherein the metal nanowires are selected from Au, Ag, Cu, Pt, and Ni. The method according to any one of claims 1 to 3,
A fluorine-based surfactant and a cellulose-based binder in an amount of 0.0005 to 0.05% by weight and 0.005 to 0.1% by weight, respectively, based on the total weight of the coating liquid A transparent conductive film produced by the method of claim 3

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