KR20200118581A - Transparent substrate, embedded electrode substrate and method for manufacturing thereof - Google Patents

Abstract

A transparent substrate according to an exemplary embodiment of the present application includes: a transparent film; a UV curable adhesive layer provided on one side of the transparent film; and a hard coating layer provided on the other side of the transparent film. The present invention can maintain the transparency of the film.

Description

Transparent substrate, buried electrode substrate, and manufacturing method thereof {TRANSPARENT SUBSTRATE, EMBEDDED ELECTRODE SUBSTRATE AND METHOD FOR MANUFACTURING THEREOF}

The present application relates to a transparent substrate, a buried electrode substrate, and a method of manufacturing the same.

Recently, Korea has provided information and attractions to city residents by creating various landscape lighting in parks and downtown areas as well as colorful signs through the fusion of advanced ICT technology and LED technology. In particular, a transparent LED display using an ITO transparent electrode material has an advantage that an LED is applied between the glass and the glass, or a transparent film to which the LED is applied is attached to one side of the glass, so that the wire is not visible, so that a luxurious display is possible. For this reason, it is used for interior interiors of hotels and department stores, and its importance is increasing in realizing the media facade of the exterior wall of a building.

The demand for transparent electrodes used for touch screens, etc., which is transparent and flows through electricity, has exploded as smart devices have spread, and the most commonly used transparent electrode is ITO (Indium Tin Oxide), an oxide of indium and tin. However, indium, the main raw material of ITO transparent electrode materials, has not much reserves worldwide, and is produced only in some countries such as China, and the production cost is high. In addition, it has the disadvantage that the LED light is not uniform because the resistance value is not applied uniformly. For this reason, transparent LEDs using ITO are limited in use as high-performance, low-cost transparent electrode materials.

It is true that ITO occupies the most weight and has been used as a transparent electrode material, but due to limitations such as economic feasibility and limited performance, research and technology development using new materials are continuously conducted. Transparent electrode materials that are drawing attention as next-generation new materials include Metal Mesh, Ag Nanowire, Carbon Nanotube (CNT), Conductive Polymer, and Graphene. Among them, metal mesh is a new material that accounts for 85% of the material that has replaced ITO, and has low cost and high conductivity, so the market is expanding in terms of its utilization.

The transparent LED display using metal mesh is easier to maintain than the existing ITO transparent display, can significantly reduce resource saving and environmental pollution prevention, and is economical by reducing manufacturing cost. In addition, it has the potential to be applied and utilized in various products as a new transparent electrode material as it can be applied to various purposes.

Korean Patent Publication No. 10-2015-0033169

The present application is to provide a transparent substrate, a buried electrode substrate, and a method of manufacturing the same.

An exemplary embodiment of the present application,

Transparent film;

UV curable adhesive layer provided on one side of the transparent film; And

Hard coating layer provided on the other side of the transparent film

It provides a transparent substrate comprising a.

In addition, another exemplary embodiment of the present application,

Forming a hard coating layer on one side of the transparent film;

Forming a UV-curable adhesive layer on the other side of the transparent film; And

Pre-heating the transparent film on which the hard coating layer and the adhesive layer are formed

It provides a method of manufacturing a transparent substrate comprising a.

In addition, another exemplary embodiment of the present application,

The transparent substrate; And

Metal foil provided on the adhesive layer of the transparent substrate

It provides a metal foil laminated film comprising a.

In addition, another exemplary embodiment of the present application,

The transparent substrate; And

Metal foil pattern buried inside the adhesive layer of the transparent substrate

It provides a buried electrode substrate comprising a.

In addition, another exemplary embodiment of the present application,

Forming a hard coating layer on one side of the transparent film;

Forming a UV-curable adhesive layer on the other side of the transparent film;

Preheating the transparent film on which the hard coating layer and the adhesive layer are formed;

Laminating a metal foil on the adhesive layer;

Patterning the metal foil to form a metal foil pattern;

Performing a thermal bonding process at a temperature of 70°C to 100°C to bury the metal foil pattern into the adhesive layer; And

Completely curing the adhesive layer

It provides a method of manufacturing a buried electrode substrate comprising a.

In addition, another exemplary embodiment of the present application provides a transparent light emitting device display including the buried electrode substrate.

According to an exemplary embodiment of the present application, by including a pre-heat-treated adhesive layer on one surface of the transparent film, and including a hard coating layer on the other surface of the transparent film, the hard coating layer and the adhesive layer are in a heat treatment process of 100°C to 170°C. It is possible to suppress the elution of oligomers from occurring in the transparent film, thereby maintaining the transparency of the film.

According to an exemplary embodiment of the present application, since a metal foil pattern is formed using a low-cost metal foil, raw material costs can be reduced when manufacturing an electrode substrate for a transparent light emitting device display. In particular, according to the exemplary embodiment of the present application, by forming a metal foil pattern on the adhesive layer and then heat-treating at a temperature of 70°C to 100°C, a buried electrode substrate in which the metal foil pattern is embedded in the adhesive layer may be manufactured.

In addition, according to an exemplary embodiment of the present application, by forming a metal foil pattern on the adhesive layer and then heat treatment at a temperature of 70 to 100°C, the adhesive layer reflecting the roughness of the metal foil surface is flattened to reduce the haze of the electrode substrate to improve transparency. Can be secured.

1 and 2 are diagrams each schematically showing a transparent substrate according to an exemplary embodiment of the present application.
3 and 4 are diagrams each schematically showing a metal foil laminate film according to an exemplary embodiment of the present application.
5 is a schematic diagram illustrating a buried electrode substrate according to an exemplary embodiment of the present application.
6 and 7 are views schematically showing a transparent substrate according to Comparative Examples 1 and 2 of the present application.
8 is a diagram schematically showing a metal foil laminate film according to Comparative Example 3 of the present application.
9 and 10 are diagrams schematically showing electrode substrates according to Examples 5 and 6 of the present application.
11 is a diagram showing optical characteristics before and after heat treatment according to the presence or absence of an adhesive layer in an exemplary embodiment of the present application.
12 is a schematic diagram illustrating an electrode substrate according to a fifth embodiment of the present application.
13 is a diagram schematically illustrating buried electrode substrates of Examples 4 and 6 as an exemplary embodiment of the present application.
14 is a diagram schematically illustrating a structure and manufacturing process of a transparent substrate according to an experimental example in an exemplary embodiment of the present application.

Hereinafter, the present application will be described in detail.

In the present application, "transparent" is intended to mean having a transmittance characteristic of about 80% or more in the visible light region (400 nm to 700 nm).

A transparent LED film is manufactured by mounting an LED element on a transparent electrode substrate. Since the solder reflow process for mounting the LED on the electrode substrate proceeds at a high temperature of around 170°C, a transparent film material for preventing changes in shape and optical properties due to heat, such as PI (polyimide) ) Or PEN (polyethylene naphthalate). However, high-functional materials such as PI and PEN are expensive and difficult to supply.

PET (polyethylene terephthalate), an inexpensive transparent substrate material, is essentially pre-heated to minimize dimensional changes in high-temperature processes. At this time, oligomers eluted from the inside of the PET film are generated on the surface of the film, resulting in an increase in haze, which makes it unsuitable for use as a transparent substrate.

Forming a hard coating layer on both sides of the PET film can suppress the elution of oligomers during the preheat treatment process, but the adhesion between the hard coating layer and the adhesive layer is poor, making it impossible to manufacture a copper clad laminated (CCL) fabric.

Accordingly, in the present application, it is possible to suppress the occurrence of oligomer elution from the PET film, and to provide a transparent substrate, a buried electrode substrate, and a manufacturing method thereof that can be applied to an electrode substrate of a transparent light emitting device display.

The transparent substrate according to an exemplary embodiment of the present application includes a transparent film; A UV curable adhesive layer provided on one side of the transparent film and subjected to preheat treatment; And a hard coating layer provided on the other side of the transparent film.

In the exemplary embodiment of the present application, the transparent film may be a polyethylene terephthalate (PET) film. The thickness of the transparent film is not particularly limited, but may be 100 μm to 250 μm.

In the exemplary embodiment of the present application, a UV curable adhesive layer is provided on one surface of the transparent film.

The adhesive layer may include one or more of epoxy-based, acrylic-based, urethane-based and derivatives thereof.

More specifically, the material of the adhesive layer may include a silane-modified epoxy resin, a bisphenol A-type phenoxy resin, a urethane acrylate oligomer, an epoxy acrylate oligomer, a polyester acrylate, a polyether acrylate, or a mixture thereof, It is not limited to this. In addition, the adhesive layer may further include a photoinitiator. As the photoinitiator, the applied binder component may be selected from various known photopolymerization initiators capable of initiating or promoting polymerization and/or crosslinking reaction by radical reaction, anionic reaction, cationic reaction, and the like.

The adhesive layer may have a refractive index of 1.45 to 1.55, and may have fluidity at a temperature of 70° C. or higher.

In the present application, the refractive index of the adhesive layer is a prism coupler (example of equipment-Metricon 2010/M), an ellipsometer; example of equipment-Horriba Scientific's UVISEL), Abbe Refractometer; equipment examples -It can be measured by Kruss' AR4). For example, using a prism coupler, the refractive index may be calculated by measuring a change in the amount of light reflected from the coating layer. More specifically, after coating a material for measuring the refractive index to a thickness of several µm on glass or other substrate with a known refractive index by a method such as spin coating, the coated sample is brought into contact with the prism. Thereafter, when a laser is incident on the prism, most of them are totally reflected, but when a specific angle of incidence and conditions are satisfied, an evanescent field is generated at the interface and light is coupled. When coupling occurs and the angle at which the intensity of light detected by the detector decreases rapidly is measured, the prism coupler can automatically calculate the refractive index of the adhesive layer from the parameters related to the polarization mode of light and the refractive index of the prism and the substrate.

The thickness of the adhesive layer may be 15 μm to 50 μm, and may be more than 20 μm and 40 μm or less.

When the thickness range of the adhesive layer is satisfied, a fine metal pattern having a line width of 20 μm or less can be completely embedded in the process of embedding the metal pattern provided on the adhesive layer, and when the thickness range of the adhesive layer is out of the thickness range, the fine metal pattern May not be completely embedded or the fluidity of the adhesive layer may be deepened, leading to pattern disconnection. More specifically, when the thickness of the adhesive layer is less than twice the thickness of the metal pattern, it is impossible to completely fill the metal pattern, so that the upper surface of the fine metal pattern is exposed, resulting in a decrease in durability due to corrosion. In addition, when the thickness of the adhesive layer exceeds twice the thickness of the metal pattern, the fluidity of the adhesive layer is deepened during the embedding process by the heat treatment process, which may lead to deformation or disconnection of the fine metal pattern.

In the exemplary embodiment of the present application, since the UV curable adhesive layer is not cured by heat, a copper foil laminated fabric may be manufactured by laminating copper foil on the UV curable adhesive layer after the preheat treatment process of the transparent substrate.

In an exemplary embodiment of the present application, a hard coating layer is provided on the other side of the transparent film.

The hard coating layer may include one or more of epoxy-based, urethane-based and urethane acrylate-based.

More specifically, the material of the hard coating layer may include a polyfunctional acrylate monomer and a polyfunctional urethane acrylate oligomer, but is not limited thereto. The polyfunctional acrylate-based monomer is preferably trifunctional or higher. The polyfunctional urethane acrylate oligomer includes both aliphatic or aromatic urethane acrylate oligomers, preferably trifunctional or higher, and more preferably tetrafunctional or higher.

The thickness of the hard coating layer may be 1 μm to 10 μm, and may be 4 μm to 8 μm.

If the thickness of the hard coating layer is less than 1 μm, the coating uniformity is not secured during the manufacturing process or the abrasion resistance of the hard coating layer is insufficient, which may cause damage to the hard coating layer, and thus, elution of oligomers generated in the heat treatment process of the film. You may not be able to control it. In addition, when the thickness of the hard coating layer exceeds 10 μm, transmittance and haze may increase, and mechanical properties may be deteriorated, such as a decrease in flexural properties.

A transparent substrate according to an exemplary embodiment of the present application is schematically shown in FIG. 1 below. As shown in Figure 1, the transparent substrate according to an exemplary embodiment of the present application, a transparent film 10; UV curable adhesive layer 20 provided on one surface of the transparent film 10; And a hard coating layer 30 provided on the other side of the transparent film 10.

In the exemplary embodiment of the present application, the transparent substrate may further include a protective film provided on the adhesive layer. As described above, the transparent substrate further including the protective film 40 is schematically shown in FIG. 2 below.

The protective film may serve to protect the adhesive layer, and may be applied after removing the protective film when manufacturing a metal foil laminated film or a buried electrode substrate as described later.

The protective film can be used to prevent damage or contamination adhesion during transport, storage or processing of the adhesive layer. Polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, which have an appropriate adhesive force with respect to the adhesive layer, protect the surface of the adhesive layer, and can be easily peeled off after completion of the purpose; Acrylic polymers such as polymethyl methacrylate; Styrene polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); Polycarbonate-based polymers and the like can be used.

The thickness of the protective film is not particularly limited as long as it is a range generally used as a film, but is in the range of 20 μm to 200 μm, preferably 30 μm to 100 μm.

A method of manufacturing a transparent substrate according to an exemplary embodiment of the present application includes the steps of forming a hard coating layer on one surface of a transparent film; Forming a UV-curable adhesive layer on the other side of the transparent film; And preheating the transparent film on which the hard coating layer and the adhesive layer are formed.

In the exemplary embodiment of the present application, the step of preheating the transparent film on which the hard coating layer and the adhesive layer are formed is performed in order to minimize the dimensional change in the high temperature process of the transparent film on which the metal foil pattern is formed thereafter. The pre-heat treatment may be performed by performing heat treatment at 130°C to 170°C for 10 to 50 minutes.

When the temperature of the preheat treatment process is less than 130° C. and less than 10 minutes, shrinkage of the film may occur when the transparent film is subsequently exposed to a high temperature of 130° C. or more. In addition, when the temperature of the pre-heat treatment process exceeds 170° C. for 50 minutes or more, the dimensional change does not occur even when exposed to high temperatures in the subsequent process, which may be time and economically unnecessary.

In the exemplary embodiment of the present application, after the preheating step, a step of forming a protective film on the adhesive layer may be further included.

In addition, the metal foil laminate film according to an exemplary embodiment of the present application includes the above-described transparent substrate; And a metal foil provided on the adhesive layer of the transparent substrate.

In the exemplary embodiment of the present application, the metal foil may include at least one of gold, silver, copper, and aluminum.

The thickness of the metal foil may be 2 μm to 20 μm, and may be 4 μm to 15 μm. In addition, the thickness of the metal foil may be 70% or less of the thickness of the adhesive layer.

The thickness range of the metal foil was set based on the commonly used copper foil for CCL (Copper Clad Laminated), and it is difficult to manufacture a freestanding copper foil for metal foils less than 2㎛, and a line width of several microns for metal foils exceeding 20㎛. It is difficult to implement a fine pattern with

A metal foil laminate film according to an exemplary embodiment of the present application is schematically shown in FIG. 3 below. As shown in FIG. 3, the metal foil laminated film according to an exemplary embodiment of the present application includes a transparent film 10; UV curable adhesive layer 20 provided on one surface of the transparent film 10; And a hard coating layer 30 provided on the other side of the transparent film 10, and a metal foil 50 is provided on the adhesive layer 20.

In the exemplary embodiment of the present application, the metal foil may be provided in the form of a metal foil pattern. A metal foil laminated film provided in the form of a metal foil pattern 60 as described above is schematically shown in FIG. 4 below.

The buried electrode substrate according to an exemplary embodiment of the present application includes the above-described transparent substrate; And a metal foil pattern embedded in the adhesive layer of the transparent substrate.

In the exemplary embodiment of the present application, a ten point average roughness (Rz) of a surface of the metal foil pattern facing the transparent film may be greater than 0.5 μm.

A buried electrode substrate according to an exemplary embodiment of the present application is schematically shown in FIG. 5 below. As shown in FIG. 5, the buried electrode substrate according to an exemplary embodiment of the present application includes a transparent film 10; UV curable adhesive layer 20 provided on one surface of the transparent film 10; And a hard coating layer 30 provided on the other side of the transparent film 10, and a metal foil pattern 60 is embedded in the adhesive layer 20 to be provided.

A method of manufacturing a buried electrode substrate according to an exemplary embodiment of the present application may include forming a hard coating layer on one surface of a transparent film; Forming a UV-curable adhesive layer on the other side of the transparent film; Preheating the transparent film on which the hard coating layer and the adhesive layer are formed; Laminating a metal foil on the adhesive layer; Patterning the metal foil to form a metal foil pattern; Performing a thermal bonding process at a temperature of 70°C to 100°C to bury the metal foil pattern into the adhesive layer; And completely curing the adhesive layer.

In the exemplary embodiment of the present application, in the step of forming a metal foil pattern by patterning the metal foil, a method known in the art may be used, for example, a photolithography process may be used. More specifically, the method of forming the metal foil pattern may include forming a resist pattern on the metal foil and then etching the metal foil, and removing the resist pattern, but is not limited thereto.

The metal foil pattern may be manufactured from a metal foil including at least one matt surface having a relatively high ten point average roughness Rz. At this time, the mat surface of the metal foil faces the transparent film.

In the exemplary embodiment of the present application, the step of forming a blackening layer on the metal foil pattern may be additionally included. The step of forming the blackening layer may be performed by a plating process using a plating solution containing at least one of copper, selenium, cobalt, nickel, manganese, magnesium, sodium, oxides thereof, and hydroxides thereof. The plating process may be an electroplating process, an electroless plating process, or the like.

In the exemplary embodiment of the present application, the metal foil pattern may be embedded into the adhesive layer by the process of thermal bonding at a temperature of 70°C to 100°C. In particular, according to an exemplary embodiment of the present application, by heat treatment at a temperature of 70°C to 100°C as described above, a buried electrode substrate in which the metal foil pattern is embedded in the adhesive layer is manufactured by thermal lamination with a film having excellent surface smoothness. can do.

In the exemplary embodiment of the present application, the process of thermal bonding at a temperature of 70° C. to 100° C. may be performed by a thermal lamination process, and the temperature of the lamination roll may be set to 70° C. or more and 100° C. or less. In addition, the lamination speed can be performed at 0.3m or more and 1m or less per minute.

In addition, the ten point average roughness Rz of the surface of the adhesive layer before the thermal bonding process may be greater than 0.5 μm, and the ten point average roughness Rz of the surface of the adhesive layer after the thermal bonding process may be 0.1 μm or less. In addition, the ten point average roughness (Rz) of the surface of the adhesive layer before the thermal bonding process may be greater than 0.5 μm and less than 3 μm. In addition, the ten point average roughness (Rz) of the surface of the adhesive layer after the thermal bonding process may be 0 to 0.1 μm. When the Rz is 0.5 µm or less, a high reflectivity peculiar to the metal foil is obtained due to low irregularities. Therefore, since it is difficult to lower the reflectance of the transparent electrode substrate manufactured therefrom, there is a disadvantage that the pattern is easily recognized by the eye due to the high reflectance. In addition, when the Rz is less than 0.5 μm, the adhesion between the metal foil and the adhesive layer is lowered, so that the metal foil pattern may be detached from the adhesive layer during the process of forming the metal foil pattern (photo process).

That is, when the inexpensive metal foil is laminated after the adhesive layer is provided on the transparent film, the surface roughness of the metal foil is transferred to the surface of the adhesive layer, thereby increasing the haze of the final product. Accordingly, according to an exemplary embodiment of the present application, after forming a metal foil pattern on the adhesive layer, by thermal lamination with a film having excellent surface smoothness at a temperature of 70°C to 100°C, the haze of the transparent electrode substrate increases according to the roughness of the metal foil surface. Can be prevented.

A method of manufacturing a buried electrode substrate according to an exemplary embodiment of the present application includes the step of completely curing the adhesive layer. Completely curing the adhesive layer may include UV curing the adhesive layer.

In addition, an exemplary embodiment of the present application provides a transparent light emitting device display including the above-described buried electrode substrate.

The transparent light emitting device display may have a structure in which solder is provided on a light emitting device mounting portion of the electrode substrate for a transparent light emitting device display, and a light emitting device is provided on the solder. The method of manufacturing the transparent light emitting device display may be manufactured using a method known in the art, except that the buried electrode substrate for a transparent light emitting device display according to the present application is used.

Hereinafter, exemplary embodiments described in the present specification are illustrated through examples. However, it is not intended to limit the scope of the embodiments by the following embodiments.

< Example >

< Example 1> Hard coating layer Structure of /PET/adhesive layer/protective film

On one side of PET (polyethylene terephthalate, Toray's XG7PH2) with a urethane primer on both sides, coated with a urethane acrylate-based hard coating solution containing a photoinitiator (UV410, manufactured by Picomax) at 100℃ for 5 minutes After drying during, curing with a light amount of 500 mJ/cm ² under a UV lamp of 365 nm wavelength to form a 3 μm-thick hard coating layer. An adhesive layer having a thickness of 25 μm was formed by applying a coating solution for an adhesive layer on the opposite surface of the PET film on which the hard coating layer was formed. As the coating solution for the adhesive layer, silane-modified epoxy resin, bisphenol A epoxy resin, and phenoxy resin were added in a weight ratio of 35:33:30, respectively, 0.5 wt% of Igacure-184 used as a photoinitiator was mixed, and MEK (methyl ethyl ketone) It was prepared by diluting with. A PET film with a hard coating layer on one side and an adhesive layer on the other side was heat-treated at 150° C. for 30 minutes, and a protective film (EPF-CS800 by Ilshin Chemical Co., Ltd.) was attached on the top of the adhesive layer using a roll laminator.

The structure of the transparent substrate according to Example 1 is schematically shown in FIG. 2 below.

< Example 2> Hard coating layer /PET/Adhesive layer/Copper foil structure

In Example 1, after removing the protective film on the adhesive layer, a copper foil having a thickness of 8 μm (LPF-8 from Iljin Materials) was thermally laminated to the adhesive layer at a speed of 0.5 mpm using a roll laminator heated at 100°C.

The structure of the metal foil laminate film according to Example 2 is schematically shown in FIG. 3 below.

< Example 3> Hard coating layer /PET/Adhesive layer/Copper foil pattern structure

In Example 2, DFR (Dry Film Resist, Asahi's SPG-152) was heat-laminated at a temperature of 100°C on the top of the copper foil, and a rectangular mesh-based wiring electrode part pattern and area with a line width of 20 μm and a line spacing of 400 μm A photomask in which a 0.01mm ² LED mounting part pattern was implemented as a negative-type was added to expose UV at a wavelength of 365 nm with an amount of light of 250 mJ/cm ² . A copper foil pattern having an uneven structure was formed on the adhesive layer through a wet patterning process leading to development-etching-peeling. All the solutions used in each process were kept at room temperature, and a 1.0 wt% aqueous solution of Na ₂ CO ₃ was used as a developer, and the etching solution was a mixed solution containing iron chloride and hydrochloric acid, and an aqueous solution of 1.0 wt% NaOH was used as the stripping solution. I did.

The structure of the metal foil laminate film according to Example 3 is schematically shown in FIG. 4 below.

< Example 4> Hard coating layer /PET/Adhesive layer/Buried copper foil pattern structure

In Example 3, a PET film having a copper foil pattern formed on the adhesive layer and a 50 µm-thick release PET film (Optiver Korea Co., Ltd. SLF050-060) were thermally laminated at a speed of 0.5 mpm using a 110°C roll laminator. In the state in which the release film was laminated, UV rays of 365 nm wavelength were irradiated with a light amount of 2,000 mJ/cm ² .

The structure of the buried electrode substrate according to Example 4 is schematically shown in FIG. 5 below.

< Example 5> Thickness control of adhesive layer in buried structure

In Example 4, the same was performed except that the thickness of the adhesive layer was 20 μm.

The structure of the buried electrode substrate according to Example 5 is schematically shown in FIG. 9 below.

< Example 6> Thickness control of adhesive layer in buried structure

In Example 4, the same was performed except that the thickness of the adhesive layer was 50 μm.

The structure of the buried electrode substrate according to Example 6 is schematically shown in FIG. 10 below.

< Comparative example 1> Structure of PET/adhesive layer/protective film

In Example 1, without forming a hard coating layer, the adhesive layer was formed on one side of the PET film, and the protective film was laminated.

The structure of the transparent substrate according to Comparative Example 1 is schematically shown in FIG. 6 below.

< Comparative example 2> Hard coating layer /PET/ Hard coating layer /Adhesive layer/Protection film structure

In Example 1, a hard coating layer was formed on both sides of a PET film, the adhesive layer was formed on one side of the hard coating, and the protective film was laminated.

The structure of the transparent substrate according to Comparative Example 2 is schematically shown in FIG. 7 below.

< Comparative example 3> Hard coating layer /PET/ Thermosetting Structure of adhesive layer/copper foil

In Example 2, the same was carried out except that the initiator contained in the adhesive layer coating solution was changed to a thermosetting type (SCI company SI-100L).

The structure of the metal foil laminated film according to Comparative Example 3 is schematically shown in FIG. 8 below.

< Experimental example >

After manufacturing a transparent substrate by the structure and process of FIG. 14, the optical properties before and after heat treatment according to the presence or absence of an adhesive layer are shown in Tables 1 and 11 below.

[Table 1]

The heat treatment process was performed at 150°C for 30 minutes.

The Haze value was measured using a transmittance meter (Nippon Denshoku Co., Ltd. COH-400).

As shown in the above results, it can be seen that the haze after heat treatment increases to a very large extent when the UV curable adhesive layer is not included.

As shown above, the Haze measured after removing the protective film of the transparent substrate prepared in Example 1 was 3.52%, and the Haze measured after removing the protective film of the transparent substrate prepared in Comparative Example 1 was 8.70%. It is measured, and it is possible to confirm the increase in Haze due to oligomer elution.

After laminating the metal foil on the transparent substrate of Comparative Example 2, it was attempted to pattern the metal foil. However, since chemicals penetrated into the interface between the hard coating layer and the adhesive layer, separation occurred, and the patterning process of the metal foil was impossible.

In Comparative Example 3, the adhesive layer was completely cured in the metal foil laminated film, so that it did not adhere to the copper foil.

In the buried electrode substrate according to Example 5, bubbles were generated on the adhesive layer between the copper foil patterns as shown in FIG. 12, and the buried electrode substrate according to Example 6 was out of position with the buried copper foil pattern in FIG. 13 below. Accordingly, in the exemplary embodiment of the present application, it is more preferable that the thickness of the adhesive layer is more than 20 μm and less than 40 μm.

As described above, according to an exemplary embodiment of the present application, by including a pre-heat-treated adhesive layer on one side of the transparent film, and including a hard coating layer on the other side of the transparent film, the hard coating layer and the adhesive layer are 100° C. It is possible to suppress the elution of oligomers from occurring in the transparent film during the heat treatment process at °C, thereby maintaining the transparency of the film.

According to an exemplary embodiment of the present application, since a metal foil pattern is formed using a low-cost metal foil, raw material costs can be reduced when manufacturing an electrode substrate for a transparent light emitting device display. In particular, according to the exemplary embodiment of the present application, by forming a metal foil pattern on the adhesive layer and then heat-treating at a temperature of 70°C to 100°C, a buried electrode substrate in which the metal foil pattern is embedded in the adhesive layer may be manufactured.

In addition, according to an exemplary embodiment of the present application, by forming a metal foil pattern on the adhesive layer and then heat treatment at a temperature of 70 to 100°C, the adhesive layer reflecting the roughness of the metal foil surface is flattened to reduce the haze of the electrode substrate to improve transparency. Can be secured.

10: transparent film
20: UV curable adhesive layer
30: hard coating layer
40: protective film
50: metal foil
60: metal foil pattern
70: thermosetting adhesive layer

Claims (18)

Transparent film;
UV curable adhesive layer provided on one side of the transparent film; And
Hard coating layer provided on the other side of the transparent film
Transparent substrate comprising a. The transparent substrate of claim 1, wherein the transparent film is a polyethylene terephthalate (PET) film. The transparent substrate according to claim 1, wherein the adhesive layer contains at least one of epoxy-based, acrylic-based, urethane-based and derivatives thereof. The transparent substrate according to claim 1, wherein the adhesive layer has a thickness of 15 μm to 50 μm. The transparent substrate according to claim 1, wherein the hard coating layer includes at least one of epoxy-based, urethane-based and urethane acrylate-based. The transparent substrate according to claim 1, wherein the thickness of the hard coating layer is 1 μm to 10 μm. The transparent substrate according to claim 1, further comprising a protective film provided on the adhesive layer. Forming a hard coating layer on one side of the transparent film;
Forming a UV-curable adhesive layer on the other side of the transparent film; And
Pre-heating the transparent film on which the hard coating layer and the adhesive layer are formed
Method of manufacturing a transparent substrate comprising a. The method of claim 8, wherein the preheating is performed by performing heat treatment at 130°C to 170°C for 10 to 50 minutes. The method of claim 8, further comprising forming a protective film on the adhesive layer after the preheating step. The transparent substrate of any one of claims 1 to 7; And
Metal foil provided on the adhesive layer of the transparent substrate
Metal foil laminate film containing a. The metal foil laminated film of claim 11, wherein the metal foil contains at least one of gold, silver, copper, and aluminum. The metal foil laminate film of claim 11, wherein the metal foil has a thickness of 2 μm to 20 μm, and is 70% or less of the thickness of the adhesive layer. The metal foil laminate film of claim 11, wherein the metal foil is provided in the form of a metal foil pattern. The transparent substrate of any one of claims 1 to 7; And
Metal foil pattern buried inside the adhesive layer of the transparent substrate
A buried electrode substrate comprising a. Forming a hard coating layer on one side of the transparent film;
Forming a UV-curable adhesive layer on the other side of the transparent film;
Preheating the transparent film on which the hard coating layer and the adhesive layer are formed;
Laminating a metal foil on the adhesive layer;
Patterning the metal foil to form a metal foil pattern;
Performing a thermal bonding process at a temperature of 70°C to 100°C to bury the metal foil pattern into the adhesive layer; And
Completely curing the adhesive layer
Method of manufacturing a buried electrode substrate comprising a. The method according to claim 16, wherein the ten point average roughness (Rz) of the surface of the adhesive layer before the thermal bonding process is greater than 0.5㎛,
The method of manufacturing a buried electrode substrate in which the ten point average roughness (Rz) of the surface of the adhesive layer after the thermal bonding process is 0.1 μm or less. A transparent light emitting device display comprising the buried electrode substrate of claim 15.

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