KR20200061257A - Overcoating composition, overcoat layer using same and silver nano wire transparent electrode film - Google Patents

Abstract

The present invention relates to an overcoating composition, an overcoating layer using the same, and a silver nanowire transparent electrode film, which improve interfacial adhesion properties of the overcoating layer by lowering a contact angle of the overcoating layer and increasing surface energy. The overcoating composition for a silver nanowire transparent electrode according to the present invention comprises: a polymer resin having a phenol functional group; a metal oxide precursor; and an acid catalyst promoting the reaction of the polymer resin and the metal oxide precursor.

Description

Overcoating composition, overcoat layer using same and silver nano wire transparent electrode film}

The present invention relates to a silver nanowire conductive film, and more particularly, to an overcoating composition having improved interfacial adhesion properties of an overcoat layer, an overcoat layer using the same, and a silver nanowire transparent electrode film.

The silver nanowire conductive film is a conductive thin film containing silver nanowires, and is a thin film having electrical conductivity by contacting each other to form a network structure. Since the silver nanowire conductive film can be formed by being coated on various substrates through a wet process, it is used in various fields such as electrodes, transparent electrodes, touch panels, optical films, displays, antistatic agents, absorbers, electromagnetic shielding films, heat dissipation materials, and sensors. .

In particular, the manufacturing process of the silver nanowire transparent electrode film mainly consists of a silver nanowire coating process and an overcoating process for protecting the silver nanowire coating layer and improving adhesion. The overcoating is mainly coated with a polymer or inorganic material, and is coated with a thickness that barely covers the silver nanowires so that the electrical conductivity of the surface can be maintained even after the overcoating, and is usually coated with a thin thickness within 100 nm.

 The overcoating layer secures the silver nanowires of the transparent electrode to the substrate to improve adhesion to the substrate and to have reliability in various use environments. In addition, when another film (hereinafter referred to as'top film') is coated or laminated (laminated) on the transparent electrode, the overcoating layer forms an interface between the transparent electrode and the upper film, thereby determining the adhesive properties of the transparent electrode and the upper film. .

 As the material of the overcoat layer, mainly polymer materials such as urethane, acrylic, phenol, and epoxy are applied. This polymer can securely fix the silver nanowires to the substrate and improve reliability. However, the polymer has a high contact angle and a low surface energy, so that when other films are stacked thereon, the interface adhesion property between the transparent electrode and the upper film is often weak.

The weakened interfacial adhesion may cause various defects when the post-processing process is performed. As a major defect, an upper film may be detached from the touch panel, and the upper film may be peeled during development or etching in the wet patterning process, or overetching may occur or it may be difficult to implement a precise pattern.

Registered Patent Publication No. 10-1861235 (Registration on May 18, 2018)

Accordingly, an object of the present invention is to provide an overcoating composition capable of improving the interfacial adhesion properties of the overcoating layer, an overcoating layer using the same, and a silver nanowire transparent electrode film.

Another object of the present invention is to provide an overcoat composition, an overcoat layer and a silver nanowire transparent electrode film using the overcoat composition capable of lowering the contact angle of the overcoat layer and increasing surface energy.

In order to achieve the above object, the present invention is a polymer resin having a phenol functional group; Metal oxide precursors; And an acid catalyst that promotes the reaction of the polymer resin and the metal oxide precursor.

The overcoat composition includes 0.5 to 3 wt% of the polymer resin, 0.2 to 20 wt% of the metal oxide precursor, and 0.1 to 10 wt% of the acid catalyst.

The polymer resin includes polyvinylphenol or polyvinylphenol copolymer.

The metal oxide precursor includes magnesium methoxide, titanium ethoxide, titanium propoxide, titanium butoxide, zirconium ethoxide, zirconium prooxide, zirconium butoxide or zirconium acetate.

The acid catalyst includes acetic acid, formic acid, hydrochloric acid or sulfuric acid.

The present invention also includes an overcoating layer formed by applying and heat treating the overcoating composition on the silver nanowire transparent electrode.

And the present invention is a substrate; A silver nanowire transparent electrode formed on the substrate; And an overcoating layer formed by applying and heat treating the overcoating composition on the silver nanowire transparent electrode.

The silver nanowire transparent electrode film according to the present invention may further include a top film formed on the overcoat layer.

And the upper film may include metal wiring.

When the overcoat composition according to the present invention includes a polymer resin having a phenol functional group, a metal oxide precursor, and an acid catalyst, when the polymer resin and the metal oxide precursor react under an acid catalyst when forming an overcoat layer with an overcoat composition. The metal oxide is substituted on the chain of the polymer resin to improve the interfacial adhesion properties by lowering the contact angle of the overcoat layer and increasing the surface energy.

When the other film (upper film) is coated or laminated on the silver nanowire transparent electrode with improved interfacial adhesion properties, interfacial separation between the silver nanowire transparent electrode and the upper film can be induced through the overcoating layer. It is possible to reduce the defective elements due to, and it is possible to reduce the defect that the pattern is peeled or overetched in the wet etching process.

In addition, when the wiring metal electrode is printed and applied over the overcoating layer, printability and adhesive properties may be improved.

In addition, the crosslinking of the polymer due to the metal oxide may improve the properties of the solvent for the organic solvent.

1 is a cross-sectional view showing a silver nanowire transparent electrode film according to the present invention.
2 is a cross-sectional view showing a state in which another film is laminated on the overcoat layer of FIG. 1.

It should be noted that in the following description, only parts necessary for understanding the embodiments of the present invention will be described, and descriptions of other parts will be omitted without detracting from the gist of the present invention.

The terms or words used in the present specification and claims described below should not be construed as being limited to ordinary or lexical meanings, and the inventor is appropriate as a concept of terms to describe his or her invention in the best way. Based on the principle that it can be defined, it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention. Therefore, the configuration shown in the embodiments and drawings described in this specification is only a preferred embodiment of the present invention, and does not represent all of the technical spirit of the present invention, and various equivalents that can replace them at the time of this application It should be understood that there may be and variations.

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

1 is a cross-sectional view showing a silver nanowire transparent electrode film according to the present invention.

1, the silver nanowire transparent electrode film 100 according to the present invention includes a substrate 10, a silver nanowire transparent electrode 20 and an overcoat layer 30. The silver nanowire transparent electrode 20 is formed on the substrate 10. In addition, the overcoat layer 30 is formed by applying and heat treating the overcoat composition on the silver nanowire transparent electrode 20. The overcoating composition includes a polymer resin having a phenol functional group, a metal oxide precursor, and an acid catalyst that promotes the reaction of the polymer resin and the metal oxide precursor.

Here, the substrate 10 may be any of glass, quartz, glass wafer, silicon wafer, transparent plastic substrate, opaque plastic substrate, transparent polymer film, and opaque polymer film. Plastic substrate materials include polyethylene terephthalate, polycarbonate, poly(ethylene-naphthalate), poly(ether sulfone), and polymethyl methacrylate (Poly (methyl methacrylate)), polyimide, polyether ether ketone, etc. may be used, but is not limited thereto.

The silver nanowire transparent electrode 20 may be formed by coating a silver nanowire dispersion on the substrate 10. Silver nanowires have a large aspect ratio of 5 to 100 nm in diameter and 1 to 500 μm in length. The silver nanowire layer 20 may be formed such that the silver nanowires are randomly arranged, or may have directionality in a specific direction.

In addition, the overcoat layer 30 is formed to cover the surface of the substrate 10 on which the silver nanowire transparent electrode 20 is formed.

Here, the overcoating composition includes a polymer resin having a phenol functional group, a metal oxide precursor, and an acid catalyst. For example, the overcoat composition contains 0.5 to 3 wt% of a polymer resin, 0.2 to 20 wt% of a metal oxide precursor, and 0.1 to 10 wt% of an acid catalyst, and the rest is a solvent. Such an overcoating composition may be prepared by dissolving a polymer resin in a solvent and adding a metal oxide precursor and an acid catalyst to the polymer resin solution.

The polymer resin includes polyvinylphenol or polyvinylphenol copolymer. For example, polyvinylphenol-polymethylmethacrylate copolymer may be used as the polyvinylphenol copolymer.

As the acid catalyst, acetic acid, formic acid, hydrochloric acid, sulfuric acid, and the like can be used.

As the metal oxide precursor, magnesium methoxide, titanium ethoxide, titanium propoxide, titanium butoxide, zirconium ethoxide, zirconium prooxide, zirconium butoxide, zirconium acetate, and the like can be used.

At this time, the metal oxide precursor may be a material capable of reacting with a phenol group of a polymer resin under an acid catalyst. The acid catalyst serves as a catalyst for preventing precipitation in the reaction of the phenol group and the metal oxide precursor of the polymer resin.

And the solvent dissolves the polymer resin and the metal oxide precursor.

Since the reaction of the phenol group and the metal oxide precursor of the polymer resin under the acid catalyst proceeds very quickly even at a relatively low temperature, the reaction is sufficiently performed in the overcoating process of the silver nanowire transparent electrode 20, for example, 130° C. or less and 5 minutes or less drying time. It can be done. As a result of the reaction, the phenol group and the metal oxide of the polymer resin are connected by chemical bonding, and as the metal oxide is replaced by the polymer resin, the surface energy is increased and the contact angle is lowered to improve wettability. Due to this, the interfacial adhesion of the overcoat layer 30 with a low contact angle is improved.

FIG. 2 is a cross-sectional view showing a silver nanowire transparent electrode film 200 in which another film 40 is stacked on the overcoat layer 30 of FIG. 1.

Referring to FIG. 2, the silver nanowire transparent electrode film 200 according to the present invention may have an upper film 40 formed on the overcoat layer 30.

Here, the upper film 40 may be formed by coating or laminating. The upper film 40 may include a metal wire 41. The upper film 40 may be a plastic film.

The overcoat layer 30 having a lower contact angle improves interfacial adhesion and improves printability and adhesion when printing the metal wiring 41 on the overcoat layer 30. In addition, the solvent resistance of the polymer resin is improved due to crosslinking of the overcoat layer 30.

In order to confirm the properties of the overcoat layer formed of the overcoat composition according to the present invention, an overcoat layer was formed after preparing the overcoat composition according to Examples and Comparative Examples. The contact angle and solvent resistance were confirmed by the properties of the overcoat layer, and the precipitation of the overcoat composition was confirmed.

[Example 1 and Comparative Example 1]

The overcoating composition according to Example 1 comprises 1.7 wt% of a polyvinylphenol-polymethylmethacrylate copolymer, 2 wt% of acetic acid and 0.8 to 16 wt% of zirconium butoxide.

The overcoat composition according to Comparative Example 1 contained 1.7 wt% of a polyvinylphenol-polymethylmethacrylate copolymer, and did not include acetic acid and zirconium butoxide.

Each of the overcoat compositions according to Example 1 and Comparative Example 1 was coated on a substrate, and the contact angle of the overcoat layer prepared by heat treatment at 130° C. for 5 minutes was measured. Table 1 shows the measurement results. In Example 1, the contact angle of the overcoat layer according to the change in the content of zirconium butoxide was measured.

According to Table 1, when the content of the polyvinylphenol-polymethylmethacrylate copolymer and acetic acid was constant, when the content of zirconium butoxide was 0.8 wt%, the contact angle was 53 MPa. When the content of zirconium butoxide increased to 3.2 wt%, the contact angle decreased to 45ㅀ, and the contact angle was found to be 38ㅀ at 16wt%. That is, the more the zirconium butoxide, a metal oxide precursor, was included, the greater the effect of lowering the contact angle of the overcoat layer.

On the other hand, the overcoat layer made of the overcoat composition according to Comparative Example 1, which did not contain a metal oxide precursor and an acid catalyst, had the highest contact angle of 57 MPa.

[Example 2]

The overcoating composition according to Example 2 was observed by changing the content of acetic acid in Example 1 to determine whether precipitation of the solution phase occurred according to the addition of acetic acid. Table 2 shows the observation results.

Referring to Table 2, when the content of acetic acid is 0 wt%, precipitation occurred immediately after preparing the overcoat composition.

When acetic acid was included in the overcoat composition, this precipitation phenomenon was suppressed. When the amount of acetic acid added was 6 wt% or more, precipitation did not occur even if it exceeded 2 hours.

And it was found that the contact angle was constant at 45ㅀ regardless of the amount of acetic acid added. It can be seen that acetic acid does not directly lower the contact angle, but rather acts as a reaction catalyst for zirconium butoxide and polymer resin.

[Example 3 and Example 4]

The overcoating composition according to Example 3 in which the type of metal oxide precursor was changed to magnesium methoxide and zirconium acetate (polyvinylphenol-polymethylmethacrylate copolymer 1.7 wt%, acetic acid 2 wt%, magnesium methoxide 0.5-1.6 wt %) and the overcoat composition according to Example 4 (polyvinylphenol-polymethylmethacrylate copolymer 1 wt%, acetic acid 3 wt%, zirconium acetate 0.2-0.8 wt%), as shown in Table 3, metal oxide A decrease in contact angle was observed with increasing precursor content.

[Example 5]

In order to evaluate the crosslinking and curability according to the reaction amount of the polymer resin and the metal oxide precursor, the overcoating composition according to Example 5 with a different content of the metal oxide precursor (polyvinylphenol-polymethylmethacrylate copolymer 1.7 wt% , Acetic acid 2 wt%, zirconium butoxide 0.5-3.2 wt%) was prepared and then solvent resistance test was performed. Table 4 shows the solvent resistance test results.

Referring to Table 4, the solvent resistance test was performed by a method of confirming that the polymer resin melts and comes out when wiped with gauze with a solvent such as ethanol or isopropyl alcohol on the overcoat layer. If the polymer resin does not come out, it can be determined that the polymer resin is crosslinked by a metal oxide.

As a result of the solvent resistance evaluation, the polymer resin was melted when the zirconium butoxide was 0.8 wt% or less, but the polymer resin was not melted from the content of zirconium butoxide more than 1 wt%. When 1 wt% or more of zirconium butoxide is added to the overcoating composition, it can be seen that crosslinking is formed due to the reaction of the phenol group and the metal oxide precursor, thereby improving dissolution stability in the solvent.

[Example 6]

After preparing the overcoating composition (polyvinylphenol-polymethylmethacrylate copolymer 1 wt%, acetic acid 3 wt%, zirconium acetate 0.2-0.8 wt%) according to Example 6 to which zirconium acetate was applied, a solvent resistance test was conducted. did. Table 5 shows the solvent resistance test results.

Referring to Table 5, even in the overcoating composition according to Example 6, as with the overcoating composition according to Example 5, a phenomenon in which solvent resistance was improved as the content of zirconium acetate increased.

On the other hand, the embodiments disclosed in the specification and the drawings are merely presented as specific examples for ease of understanding, and are not intended to limit the scope of the present invention. It is obvious to those skilled in the art to which the present invention pertains that other modifications based on the technical idea of the present invention can be implemented in addition to the embodiments disclosed herein.

10: substrate
20: silver nanowire transparent electrode
30: overcoat layer
40: upper film
41: metal wiring
100, 200: silver nanowire transparent electrode film

Claims (12)

Polymer resin having a phenol functional group;
Metal oxide precursors; And
An acid catalyst that accelerates the reaction of the polymer resin and the metal oxide precursor;
Overcoat composition for a silver nanowire transparent electrode comprising a. According to claim 1,
The polymer resin 0.5 to 3 wt%, the metal oxide precursor 0.2 to 20 wt%, and the acid catalyst, 0.1 to 10 wt% of the silver nanowire overcoating composition for a transparent electrode. According to claim 1,
The polymer resin is an overcoat composition for a silver nanowire transparent electrode containing polyvinylphenol or polyvinylphenol copolymer. According to claim 1,
The metal oxide precursor is a magnesium methoxide, titanium ethoxide, titanium propoxide, titanium butoxide, zirconium ethoxide, zirconium prooxide, zirconium butoxide or zirconium acetate overcoating composition for silver nanowire transparent electrodes. According to claim 1,
The acid catalyst is an acetic acid, formic acid, hydrochloric acid or silver nanowire overcoating composition for a transparent electrode containing sulfuric acid. An overcoating layer formed by applying and heat-treating an overcoat composition on a silver nanowire transparent electrode,
The overcoat composition,
Polymer resin having a phenol functional group;
Metal oxide precursors; And
An acid catalyst that accelerates the reaction of the polymer resin and the metal oxide precursor;
The overcoat layer for a silver nanowire transparent electrode comprising a. The method of claim 6,
The overcoat composition is an overcoating layer for a silver nanowire transparent electrode comprising 0.5 to 3 wt% of the polymer resin, 0.2 to 20 wt% of the metal oxide precursor, and 0.1 to 10 wt% of the acid catalyst. Board;
A silver nanowire transparent electrode formed on the substrate; And
Includes an overcoating layer formed by applying and heat-treating an overcoating composition on the silver nanowire transparent electrode.
The overcoat composition,
Polymer resin having a phenol functional group;
Metal oxide precursors; And
An acid catalyst that accelerates the reaction of the polymer resin and the metal oxide precursor;
Silver nanowire transparent electrode film comprising a. The method of claim 8,
The overcoating composition is a silver nanowire transparent electrode film comprising 0.5 to 3 wt% of the polymer resin, 0.2 to 20 wt% of the metal oxide precursor, and 0.1 to 10 wt% of the acid catalyst. The method of claim 8,
The polymer resin includes polyvinylphenol or polyvinylphenol copolymer,
The metal oxide precursor includes magnesium methoxide, titanium ethoxide, titanium propoxide, titanium butoxide, zirconium ethoxide, zirconium prooxide, zirconium butoxide or zirconium acetate,
The acid catalyst is a silver nanowire transparent electrode film containing acetic acid, formic acid, hydrochloric acid or sulfuric acid. The method of claim 8,
An upper film formed on the overcoat layer;
Silver nanowire transparent electrode film further comprising a. The method of claim 11,
The upper film is a silver nanowire transparent electrode film including a metal wiring.

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