Transparent electrode film, its manufacturing method and device including the same

Abstract

The present invention relates to an electrode film including a transparent substrate and electrode layers disposed on both sides of the transparent substrate, wherein the electrode layer has a thickness of 200 nm to 1,000 nm, and the electrode layer has a crack density value of 0 to 0.2 calculated by Equation 1 at a tensile strain of 1% to 10%, a method for manufacturing the transparent electrode film, and a device including the transparent electrode film.

Description

[Technical Field]

[0001] The present invention relates to a transparent electrode film, a method for producing the same, and a device including the same. [Background technology]

[0002] As computers using digital technology have developed, computer auxiliary devices have also been developed. In particular, personal computers, portable communication devices, and other personal information processing devices use various input devices such as keyboards and mice to process text and graphics.

[0003] However, as the use of computers continues to expand with the rapid advancement of the information society, it is becoming difficult to operate products efficiently using only keyboards and mice, which currently function as input devices. Therefore, there is a growing need for devices that are not only simple but also have fewer operational errors and allow anyone to easily input information.

[0004] In addition, interest in input device technology has shifted beyond general functionality to reliability, durability, innovation, design and processing technology, etc., and to achieve these goals, touch panels have been developed as input devices that can input information such as text and graphics.

[0005] Such touch panels are provided on various display panels and are used by users to select desired information while viewing the image display device.

[0006] Meanwhile, touch panels are classified into resistive, capacitive, electro-magnetic, SAW (surface acoustic wave) and infrared types. These various types of touch panels are adopted in electronic products taking into consideration issues such as signal amplification, differences in resolution, difficulty of design and processing technology, optical characteristics, electrical characteristics, mechanical characteristics, environmental resistance, input characteristics, durability and economic efficiency, with resistive and capacitive touch panels currently being used in the widest range of fields.

[0007] Such resistive and capacitive touch panels use an electrode layer for generating an electrical signal when touched by a user, and the electrode layer is generally configured in the form of a conductive laminate or an electrode film.

[0008] Korean Patent Publication No. 10-2020-0074862 also discloses an electrode film that can be used for touch panels and the like.

[0009] Meanwhile, with the recent advancement of technology, devices using flexible materials as substrates, such as flexible displays, have appeared.

[0010] However, conventional electrode films, including those disclosed in Korean Patent Publication No. 10-2020-0074862, have problems such as cracks occurring in the electrode layer due to external stress or excessive increases in surface resistance, making them unsuitable for use in devices such as flexible displays.

[0011] Therefore, there is a growing need for an electrode film that is suitable for use in devices such as flexible displays, since it does not cause cracks in the electrode layer due to external stress and does not excessively increase surface resistance. Summary of the Invention [Problem to be solved by the invention]

[0012] SUMMARY OF THE INVENTION An object of the present invention is to provide a transparent electrode film that is less susceptible to cracking due to external stress and has a reduced increase in surface resistance.

[0013] Another object of the present invention is to provide a transparent electrode film having improved adhesion between the transparent substrate and the electrode layer.

[0014] Another object of the present invention is to provide a transparent electrode film in which the peeling force of the protective film from the electrode layer is optimized.

[0015] Another object of the present invention is to provide a method for producing the transparent electrode film and a device including the same.

[0016] However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0017] The present invention relates to an electrode film including a transparent substrate and electrode layers disposed on both sides of the transparent substrate, wherein the electrode layer has a thickness of 200 nm to 1,000 nm, and the electrode layer has a crack density value of 0 to 0.2 calculated by the following formula 1 at a tensile strain of 1% to 10%:

[0018] [Formula 1] ρ(ε)=l(ε) / A (In the above formula 1, ε is the tensile strain (%), and A is the area of the observation region (mm 2 ), where ρ(ε) is the crack density value of the electrode layer calculated at tensile strain ε, and l(ε) is the crack area (mm 2 ) means. In the first aspect of the present invention, the electrode layer may have a crack density value calculated by the above formula 1 at a tensile strain of 2% of 0 to 0.1.

[0019] In the second aspect of the present invention, the electrode layer may have a crack density value of 0 calculated by the above formula 1 at a tensile strain of 2%.

[0020] In a third aspect of the present invention, the electrode layer may have a sheet resistance increase rate of 15% or less when subjected to a tensile strain of 1% to 10%, calculated by the following formula 2:

[0021] [Formula 2] δ(ε)=[{RS(ε) / RS(0)}-1]×100 (In the above formula 2, δ(ε) is the sheet resistance increase rate (%) of the electrode layer calculated at tensile strain ε, RS(ε) is the sheet resistance value (Ω / □) of the electrode layer measured at tensile strain ε, RS(0) is the sheet resistance value (Ω / □) of the electrode layer measured in the initial state where the tensile strain is 0%, and ε has the same meaning as in formula 1.) In a fourth aspect of the present invention, the electrode layer may have an increase in sheet resistance of 15% or less when subjected to a tensile strain of 1% as calculated by the above formula 2.

[0022] In a fifth aspect of the present invention, the electrode layer has a surface indentation hardness of 150 N / mm 2 ~160N / mm 2 It may also be one of the following.

[0023] In a sixth aspect of the present invention, the electrode layer may have a surface resistance of 400 Ω / □ to 550 Ω / □.

[0024] In a seventh aspect of the present invention, the electrode layer may have a difference in sheet resistance before and after a light resistance evaluation of 100 Ω / □ or less.

[0025] In an eighth aspect of the present invention, the electrode layer may be produced from a composition for forming an electrode layer, the composition comprising a conductive polymer; and one or more selected from the group consisting of an organic binder, an organic solvent, a silane coupling agent, and a surfactant.

[0026] In a ninth aspect of the present invention, the conductive polymer is selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluenesulfonic acid, poly( The polythiophene may contain one or more selected from the group consisting of polythiophene:3,4-ethylenedioxythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrenesulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrenesulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrenesulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid, and polythiophene:dodecylbenzenesulfonic acid.

[0027] In a tenth aspect of the present invention, the silane coupling agent may be contained in an amount of 0.05% by weight to 0.3% by weight relative to the total weight of the composition for forming an electrode layer.

[0028] In an eleventh aspect of the present invention, the transparent substrate may contain one or more resins selected from the group consisting of cycloolefin resins, cellulose resins, acrylate resins, and polyester resins.

[0029] In a twelfth aspect of the present invention, the transparent substrate may have a thickness of 50 μm to 150 μm.

[0030] In a thirteenth aspect, the present invention may further include a protective film disposed on one surface of the electrode layer.

[0031] In a fourteenth aspect of the present invention, the protective film may have a peel strength of 1.0 N / 25 mm to 5.0 N / 25 mm.

[0032] In a fifteenth aspect of the present invention, the transparent electrode film may have a curl of 30 mm or less after a heat resistance test.

[0033] In a sixteenth aspect of the present invention, the transparent electrode film may have a transmittance of 85% or more.

[0034] In a seventeenth aspect of the present invention, the transparent electrode film may have a haze of 1% or less.

[0035] The present invention also relates to a method for manufacturing the transparent electrode film, including the steps of: providing a transparent substrate (S1); forming a first electrode layer on one side of the transparent substrate (S2); forming a first protective film on one side of the first electrode layer (S3); forming a second electrode layer on the other side of the transparent substrate (S4); and forming a second protective film on one side of the second electrode layer (S5).

[0036] The present invention also relates to a method for manufacturing the transparent electrode film, including the steps of: (M1) providing a transparent substrate; (M2) forming a first electrode layer and a second electrode layer on both sides of the transparent substrate, respectively; and (M3) forming a first protective film and a second protective film on one side of the first electrode layer and one side of the second electrode layer, respectively.

[0037] The present invention also relates to a device comprising the transparent electrode film. [Effects of the Invention]

[0038] The transparent electrode film according to the present invention may further reduce crack generation and sheet resistance increase rate due to external stress compared to conventional transparent electrode films.

[0039] Furthermore, the transparent electrode film according to the present invention may have improved adhesion between the transparent substrate and the electrode layer compared to conventional transparent electrode films.

[0040] Furthermore, the transparent electrode film according to the present invention may have a more optimized peeling force of the protective film from the electrode layer compared to conventional transparent electrode films. [Brief explanation of the drawings]

[0041] [Figure 1] FIG. 1 is a diagram showing a laminated structure of a transparent electrode film according to one or more embodiments of the present invention. [Figure 2] FIG. 2 is a diagram showing a laminate structure of a transparent electrode film according to one or more embodiments of the present invention. [Figure 3] FIG. 3 is a diagram showing a method for measuring the crack area of an electrode layer according to an embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating a method for manufacturing a transparent electrode film according to one or more embodiments of the present invention. [Figure 5] FIG. 5 is a diagram illustrating a method for manufacturing a transparent electrode film according to one or more embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0042] The present invention relates to a transparent electrode film that reduces crack generation and sheet resistance increase rate due to external stress.

[0043] More specifically, the present invention relates to an electrode film including a transparent substrate; and electrode layers disposed on both sides of the transparent substrate, wherein the thickness of the electrode layer is 200 nm to 1,000 nm, and the electrode layer has a crack density value of 0 to 0.2 calculated by the following formula 1 at a tensile strain of 1% to 10%.

[0044] [Formula 1] ρ(ε)=l(ε) / A (In the above formula 1, ε is the tensile strain (%), and A is the area of the observation region (mm 2 ), where ρ(ε) is the crack density value of the electrode layer calculated at tensile strain ε, and l(ε) is the crack area (mm 2 ) means. The present invention also relates to a method for manufacturing the transparent electrode film, including the steps of: providing a transparent substrate (S1); forming a first electrode layer on one side of the transparent substrate (S2); forming a first protective film on one side of the first electrode layer (S3); forming a second electrode layer on the other side of the transparent substrate (S4); and forming a second protective film on one side of the second electrode layer (S5).

[0045] The present invention also relates to a method for manufacturing the transparent electrode film, including the steps of: (M1) providing a transparent substrate; (M2) forming a first electrode layer and a second electrode layer on both sides of the transparent substrate, respectively; and (M3) forming a first protective film and a second protective film on one side of the first electrode layer and one side of the second electrode layer, respectively.

[0046] Hereinafter, the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and to facilitate a better understanding of the technical concept of the present invention together with the above-described content of the invention. Therefore, the present invention should not be interpreted as being limited only to the details shown in these drawings.

[0047] The terms used herein are for the purpose of describing embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless otherwise specified in the stationery. For example, the term "electrode layer" used herein may refer to at least one of the first and second electrode layers, and the term "protective film" may refer to at least one of the first and second protective films.

[0048] As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, operations and / or elements other than the stated components, steps, operations and / or elements. The same reference numerals refer to the same components throughout the specification.

[0049] Spatially relative terms such as "below," "bottom," "lower," "upper," "top," and the like may be used to easily describe the relationship of one element or component to another, as illustrated in the drawings. Spatially relative terms should be understood to include different orientations of elements in use or operation in addition to the orientation depicted in the drawings. For example, if an element depicted in the drawings is inverted, an element described as "below" or "below" another element may be placed "above" the other element. Thus, the exemplary term "below" can encompass both an orientation of below and above. Elements may be oriented in other directions, and thus spatially relative terms may be interpreted accordingly.

[0050] As used herein, "substantially" can be interpreted to include not only being completely physically identical or identical, but also being within the range of error in measurement or manufacturing processes, for example, being within an error range of 0.1% or less.

[0051] 1 and 2 are diagrams showing a laminate structure of a transparent electrode film according to one or more embodiments of the present invention.

[0052] Referring to Figures 1 and 2, a transparent electrode film according to one or more embodiments of the present invention may include a transparent substrate 10 and electrode layers 21 and 22 disposed on both sides of the transparent substrate, and may further include protective films 31 and 32 disposed on one side of the electrode layers 21 and 22, as needed.

[0053] The transparent substrate 10 may serve to provide a structural base on which the electrode layers 21 and 22 or the protective films 31 and 32 are formed.

[0054] In one embodiment, the transparent substrate 10 may preferably have a transmittance of 85% or more, more preferably 90% or more, from the viewpoint of improving the transmittance of the transparent electrode film.

[0055] The transparent substrate 10 is a structural base for forming the electrode layers 21 and 22 or the protective films 31 and 32, and is not particularly limited as long as it satisfies the above-mentioned range of transmittance, but may preferably include at least one selected from the group consisting of cycloolefin resin, cellulose resin, acrylate resin, and polyester resin. More specifically, the transparent substrate 10 may be, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), etc.

[0056] In one embodiment, the transparent substrate 10 may have a thickness of 50 μm to 150 μm. If the thickness of the transparent substrate 10 is less than 50 μm, problems such as an inability to properly support the electrode layers 21 and 22 or the protective films 31 and 32 may occur, and if the thickness exceeds 150 μm, the excessive thickness increases the overall film thickness, which may cause problems such as a decrease in the transmittance or flexibility of the transparent electrode film.

[0057] In one embodiment, a surface treatment may be performed on one or both sides of the transparent substrate 10 to improve adhesion between the electrode layers 21, 22 and the transparent substrate 10. The surface treatment may be any treatment that improves adhesion between the electrode layers 21, 22 and the transparent substrate 10, and may be, for example, a pretreatment process such as a corona treatment, a plasma treatment, ultraviolet irradiation, or a primer treatment. When the surface treatment is performed on one or both sides of the transparent substrate 10, the adhesion between the electrode layers 21, 22 and the transparent substrate 10 is further improved, which may facilitate the formation of the electrode layers 21, 22 on the transparent substrate 10 without the need for a separate optically clear adhesive (OCA) film, and may be advantageous in terms of improving transmittance, etc.

[0058] The electrode layers 21, 22 may have a visible light transmittance of 50% or more and preferably contain a conductive polymer. The electrode layers 21, 22 may be made of an electrode layer-forming composition containing, for example, a conductive polymer and at least one selected from the group consisting of an organic binder, an organic solvent, a silane coupling agent, and a surfactant, and may further contain a remaining amount of water according to user needs. In this case, even if the electrode layers 21, 22 are subjected to deformation due to external stress, the occurrence of cracks can be prevented, and therefore, an excessive increase in surface resistance can be prevented.

[0059] The conductive polymer may be a conventional or later developed conductive polymer material, for example, polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluenesulfonic acid, poly(3,4-ethylenedioxythiophene):dodecylbenzenesulfonate ... The polymer may contain one or more selected from the group consisting of sulfonic acid, polyaniline:polystyrene sulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrene sulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrene sulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid, and polythiophene:dodecylbenzenesulfonic acid, and is preferably poly(3,4-ethylenedioxythiophene) or poly(3,4-ethylenedioxythiophene):polystyrene sulfonate.

[0060] The content of the conductive polymer is not particularly limited, but may be 10 wt % to 65 wt %, preferably 10 wt % to 50 wt %, and more preferably 11 wt % to 30 wt %, based on the total weight of the composition for forming an electrode layer.

[0061] The organic binder may contain one or more resins selected from the group consisting of melamine resins, polyester resins, polyurethane resins, and polyacrylic resins.

[0062] The organic binder may also be a water-dispersible resin. In one embodiment, the weight average molecular weight of the organic binder may be 5,000 g / mol to 30,000 g / mol, preferably 10,000 g / mol to 20,000 g / mol.

[0063] The content of the organic binder is not particularly limited, but may be 1 wt % to 20 wt %, preferably 1 wt % to 10 wt %, and more preferably 1 wt % to 5 wt %, relative to the total weight of the composition for forming an electrode layer.

[0064] The organic solvent may include an alcohol-based organic solvent, an ether-based organic solvent, and / or an amide-based organic solvent.

[0065] The alcohol-based organic solvent serves to reduce the surface tension of the electrode layer-forming composition and improve coatability. In one embodiment, the alcohol-based organic solvent may be an alcohol having 1 to 4 carbon atoms, such as methanol, ethanol, propanol, isopropanol, or n-butyl alcohol.

[0066] The ether-based organic solvent may be a conventional or later developed ether-based organic solvent, such as propylene glycol monopropyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, or diethylene glycol-2-ethylhexyl ether.

[0067] The amide-based organic solvent serves to improve the conductivity of the electrode layer. In one embodiment, the amide-based organic solvent may be acetamide, N-methylacetamide, N-dimethylacetamide, N-methylpyrrolidone, or the like.

[0068] The content of the organic solvent is not particularly limited, but may be 10% by weight to 80% by weight, preferably 40% by weight to 65% by weight, and more preferably 45% by weight to 60% by weight, based on the total weight of the composition for forming an electrode layer.

[0069] The silane coupling agent improves the adhesive strength of the electrode layer-forming composition and serves to facilitate lamination of the electrode layers 21 and 22 on the transparent substrate 10 . In one embodiment, the silane coupling agent may include at least one selected from the group consisting of trimethoxy-based silanes, triethoxy-based silanes, tetramethoxy-based silanes, and tetraethoxy-based silanes. For example, the triethoxy-based silane may be 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, (3-aminopropyl)triethoxysilane, (pentafluorophenyl)triethoxysilane, (3-glycidyloxypropyl)triethoxysilane, or (4-chlorophenyl)triethoxysilane. The trimethoxy-based silane may be (3-glycidyloxypropyl)trimethoxysilane, (3-chloropropyl)trimethoxysilane, (3-mercaptopropyl)trimethoxysilane, (3-glycidyloxypropyl)trimethoxysilane, (3-aminopropyl)trimethoxysilane, [3-(2-aminoethylamino)propyl]trimethoxysilane, (N,N-dimethylaminopropyl)trimethoxysilane, (N,The silane may be (3-iodopropyl)trimethoxysilane, (3-bromopropyl)trimethoxysilane, or (3-iodopropyl)trimethoxysilane.

[0070] The content of the silane coupling agent may be 0.05 wt % to 0.3 wt % relative to the total weight of the composition for forming the electrode layer, in order to improve the adhesion between the transparent substrate 10 and the electrode layers 21 and 22.

[0071] The surfactant may be a silicone surfactant or an acetylene surfactant, and the silicone surfactant may be a voice-modifying silicone surfactant.

[0072] For example, a commercially available silicone surfactant is BYK-378 manufactured by BYK, and a commercially available acetylene surfactant is Dynol 604 manufactured by Air Products.

[0073] The content of the surfactant is not particularly limited, but may be 0.02 wt % to 0.4 wt %, preferably 0.1 wt % to 0.4 wt %, based on the total weight of the composition for forming an electrode layer.

[0074] In one embodiment, the electrode layers 21 and 22 may have a thickness of 200 nm to 1,000 nm, preferably 200 nm to 500 nm, and more preferably 200 nm to 300 nm, in which case the electrode layers 21 and 22 ensure a predetermined transmittance, are not significantly affected by external stress, and allow for the manufacture of a thin electrode film.

[0075] In one embodiment, the electrode layers 21 and 22 may have a crack density value calculated by the following equation 1 at a tensile strain of 1% to 10% of 0 to 0.2, preferably 0 to 0.1, and more preferably 0 to 0.05.

[0076] [Formula 1] ρ(ε)=l(ε) / A In the above formula 1, ε is the tensile strain (%), and A is the area of the observation region (mm 2 ), where ρ(ε) is the crack density value of the electrode layer calculated at tensile strain ε, and l(ε) is the crack area (mm 2 ) means

[0077] FIG. 3 is a diagram showing a method for measuring the crack area of an electrode layer according to an embodiment of the present invention.

[0078] Specifically, referring to FIG. 3, A may refer to the area of an observation region 1000 arbitrarily designated by a user to calculate the crack density value of the electrode layer due to tensile deformation, and l(ε) may refer to the area of the black portion in the shaded image (right) obtained by converting an image (left) of the electrode layer in the observation region 1000 photographed using an optical microscope (OM) or a scanning electron microscope (SEM) into a shaded image (right) using an image processing program such as Image J (developed by NIH / LOCI).

[0079] Therefore, the crack density value calculated by the above equation 1 can be interpreted as meaning that the closer it is to 0, the less cracks occur in the electrode layer, and the closer it is to 1, the more cracks occur over the entire surface of the electrode layer.

[0080] In other words, when the electrode layers 21 and 22 are subjected to a tensile strain of 1% to 10% and the crack density value calculated by the above-mentioned formula 1 satisfies the above range, it is possible to prevent cracks from occurring due to changes in external stress, which is advantageous in that stable operation is possible even against changes in external stress.

[0081] In another embodiment, the electrode layers 21 and 22 may have a sheet resistance increase rate of 15% or less, preferably 0% to 14%, calculated by the following equation 2, at a tensile strain of 1% to 10%.

[0082] [Formula 2] δ(ε)=[{RS(ε) / RS(0)}-1]×100 In the above equation 2, δ(ε) is the sheet resistance increase rate (%) of the electrode layer calculated at tensile strain ε, RS(ε) is the sheet resistance value (Ω / □) of the electrode layer measured at tensile strain ε, RS(0) is the sheet resistance value (Ω / □) of the electrode layer measured in the initial state where the tensile strain is 0%, and ε has the same meaning as in equation 1.

[0083] When the electrode layers 21 and 22 are subjected to a tensile strain of 1% to 10% and the sheet resistance increase rate calculated by the above equation 2 satisfies the above range, an excessive increase in sheet resistance due to changes in external stress can be prevented, which is advantageous in that stable operation is possible even against changes in external stress.

[0084] On the other hand, the sheet resistance (RS(0)) of the electrode layers 21 and 22 measured in the initial state where the tensile strain is 0% may be 400Ω / □ to 550Ω / □, preferably 450Ω / □ to 530Ω / □, from the viewpoint of smooth operation of the transparent electrode film.

[0085] The electrode layers 21 and 22 have a surface indentation hardness of 150 N / mm 2 ~160N / mm 2In this case, the increased surface hardness of the substrate may be advantageous in that it not only facilitates protection of the electrode film from external impacts but also allows for appropriate flexural properties. In one embodiment, the surface indentation hardness may be measured using a method commonly used in the art, for example, by using a nanoindentation device to measure the surface indentation hardness at a load of 0.05 mN to 0.3 mN for a maximum load reaching time of 10 seconds to 20 seconds.

[0086] The electrode layers 21 and 22 may have a difference in surface resistance of 100 Ω / □ or less before and after the light resistance evaluation. In this case, there is an advantage that the initial sensitivity of the touch sensor can be maintained without being reduced by external light. In one embodiment, the light resistance evaluation may be measured by a method commonly used in the industry, for example, using a fader meter.

[0087] The protective films 31 and 32 may be provided for the purpose of preventing scratches, contamination, corrosion, etc. on the surfaces of the electrode layers 21 and 22 that may occur during the production, transportation, or storage of the transparent electrode film, and may be peeled off and removed from the transparent electrode film before the transparent electrode film is used in a device.

[0088] It is preferable that the protective films 31 and 32 have a peel strength of 1.0 N / 25 mm to 5.0 N / 25 mm from the transparent electrode film, more specifically, the electrode layers 21 and 22. The peel strength may be measured using a universal testing machine to measure the 90° peel strength (N / 25 mm) between the electrode layers 21 and 22 and the protective films 31 and 32 at a speed of 30 mm / min. When the peel strength of the protective films 31 and 32 satisfies the above range, no air bubbles are introduced during the manufacture of the transparent electrode film, and the electrode layers 21 and 22 are not damaged when the protective films 31 and 32 are peeled from the electrode layers 21 and 22, thereby further improving the durability of the electrode film.

[0089] The protective films 31 and 32 may each include a writing film and an adhesive layer formed on the writing film.

[0090] The writing film may be any conventional or later developed writing film, and may include, for example, one or more selected from the group consisting of polyolefin-based films, polyester-based films, acrylic-based films, styrene-based films, amide-based films, polyvinyl chloride-based films, polyvinylidene chloride-based films, and polycarbonate-based films. The thickness of the writing film may be 200 μm to 300 μm, taking into consideration the possibility of deformation during the manufacturing, transportation, or storage of the transparent electrode film, and the adhesiveness to the electrode layers 21 and 22.

[0091] The adhesive layer may be formed using an adhesive, and preferably has an appropriate adhesive strength so that only the protective films 31, 32 are cleanly removed from the electrode layers 21, 22 when the protective films 31, 32 are peeled off, and does not affect other components such as the electrode layers 21, 22, as well as transparency and thermal stability.

[0092] The adhesive may be any conventional or later developed adhesive, and in one or more embodiments, may be an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl alcohol adhesive, a polyvinylpyrrolidone adhesive, a polyacrylamide adhesive, a cellulose adhesive, a vinyl alkyl ether adhesive, etc. The adhesive is not particularly limited as long as it has adhesive strength and point elasticity, but from the viewpoint of availability, etc., it may preferably be an acrylic adhesive, which may contain, for example, a (meth)acrylate copolymer, a crosslinking agent, and a solvent.

[0093] The crosslinking agent may be a conventional or later developed crosslinking agent, and may include, for example, a polyisocyanate compound, an epoxy resin, a melamine resin, a urea resin, a dialdehyde, a methylol polymer, or the like, and preferably includes a polyisocyanate compound.

[0094] The solvent may include conventional solvents used in the field of resin compositions, such as alcohol-based compounds such as methanol, ethanol, isopropanol, butanol, and propylene glycol methoxyalcohol; ketone-based compounds such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, and dipropyl ketone; acetate-based compounds such as methyl acetate, ethyl acetate, butyl acetate, and propylene glycol methoxyacetate; cellosolve-based compounds such as methyl cellosolve, ethyl cellosolve, and propyl cellosolve; and hydrocarbon-based compounds such as hexane, heptane, benzene, toluene, and xylene. These may be used alone or in combination of two or more.

[0095] The thickness of the adhesive layer may be appropriately determined depending on the type of resin acting as the adhesive, adhesive strength, the environment in which the adhesive is used, etc. In one embodiment, the adhesive layer may have a thickness of 1 μm to 30 μm so that the peel force of the protective films 31 and 32 is 1.0 N / 25 mm to 2.4 N / 25 mm.

[0096] The transparent electrode film of the present invention, which is obtained by combining components satisfying the above-mentioned technical features, can have reduced curling, excellent transmittance, and reduced haze.

[0097] Specifically, the transparent electrode film of the present invention may have a curl of 30 mm or less after heat resistance evaluation. In one embodiment, the heat resistance evaluation may be performed by measuring the curl of the transparent electrode film at room temperature after leaving it at a temperature of 70°C to 90°C for 10 to 50 minutes.

[0098] Furthermore, the transparent electrode film of the present invention may have a transmittance of 85% or more and a haze of 1% or less, which may further improve the optical properties of a device to which the transparent electrode film is applied.

[0099] 4 and 5 are diagrams illustrating a method for manufacturing a transparent electrode film according to one or more embodiments of the present invention.

[0100] Referring to FIG. 4, a method for manufacturing a transparent electrode film according to one embodiment of the present invention may include the steps of: providing a transparent substrate 10 (S1); forming a first electrode layer 21 on one side of the transparent substrate 10 (S2); forming a first protective film 31 on one side of the first electrode layer 21 (S3); forming a second electrode layer 22 on the other side of the transparent substrate 10 (S4); and forming a second protective film 32 on one side of the second electrode layer 22 (S5).

[0101] Referring to FIG. 5, a method for manufacturing a transparent electrode film according to another embodiment of the present invention may include the steps of (M1) providing a transparent substrate 10; (M2) forming a first electrode layer 21 and a second electrode layer 22 on both sides of the transparent substrate 10, respectively; and (M3) forming a first protective film 31 and a second protective film 32 on one side of the first electrode layer 21 and the second electrode layer 22, respectively.

[0102] In one embodiment, the step of forming the electrode layers 21 and 22 may be performed by a printing method, such as gravure printing, screen printing, offset printing, inkjet printing, etc. In this case, a composition for forming an electrode layer including a conductive polymer (e.g., PEDOT:PSS) may be used with a viscosity appropriate for each printing method.

[0103] In one embodiment, the step of forming the protective films 31 and 32 may be performed by lamination, but is not limited thereto.

[0104] In addition to the transparent electrode film and its manufacturing method, the present invention also includes a device including the same. The device is not particularly limited as long as it is in a technical field to which the transparent electrode film of the present invention can be applied, and can be used, for example, as a touch panel that can be applied to a flexible display. [Example]

[0105] Hereinafter, specific examples of the present invention will be described. However, the present invention is not limited to the examples disclosed below and may be embodied in various different forms. However, these examples are provided to fully disclose the present invention and to fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the claims.

[0106] Examples and Comparative Examples: Fabrication of Transparent Electrode Film Example 1 The transparent electrode film of Example 1, having a laminated structure of electrode layer (PEDOT) / transparent substrate (PET) / electrode layer (PEDOT), was produced by applying a PEDOT electrode layer-forming composition to both sides of a 50 μm-thick polyethylene terephthalate (PET) film and drying it at 90°C for about 5 to 10 minutes to form an electrode layer with a thickness of 200 nm.

[0107] At this time, the composition for forming the PEDOT electrode layer was a mixture of 13 wt % PEDOT:PSS, 2 wt % polyester resin, 50 wt % ethanol, and 35 wt % water.

[0108] Example 2 A transparent electrode film of Example 2 having a laminated structure of electrode layer (PEDOT) / transparent substrate (COP) / electrode layer (PEDOT) was fabricated by the same manufacturing method as in Example 1, except that a 50 μm thick cycloolefin polymer (COP) film was used as the transparent substrate.

[0109] Example 3 A transparent electrode film of Example 3 having a laminated structure of electrode layer (PEDOT) / transparent substrate (TAC) / electrode layer (PEDOT) was produced by the same manufacturing method as in Example 1, except that a 50 μm thick triacetyl cellulose (TAC) film was used as the transparent substrate.

[0110] Comparative Example 1 A 50 μm thick polyethylene terephthalate (PET) film was placed inside, and 450 W of DC power was applied to operate the sputtering gun. Plasma was then induced into an ITO (10 wt% Sn-doped In2O3) target to form 100 nm thick indium tin oxide (ITO) electrode layers on both sides of the PET film, thereby producing a transparent electrode film of Comparative Example 1 having a laminated structure of electrode layer (ITO) / transparent substrate (PET) / electrode layer (ITO).

[0111] Comparative Example 2 A transparent electrode film of Comparative Example 2 having a laminated structure of electrode layer (AgNW) / transparent substrate (PET) / electrode layer (AgNW) was fabricated using the same manufacturing method as Comparative Example 1, except that 100 nm thick silver nanowires (AgNW) were used as the electrode layer.

[0112] Comparative Example 3 A transparent electrode film of Comparative Example 3 having a laminated structure of electrode layer (Cu metal mesh) / transparent substrate (PET) / electrode layer (Cu metal mesh) was fabricated using the same manufacturing method as Comparative Example 1, except that a 100 nm thick copper mesh electrode was used as the electrode layer.

[0113] Experimental Example (1) Evaluation of crack density and surface resistance For the transparent electrode films of the Examples and Comparative Examples, the crack density and the sheet resistance increase rate were calculated using Equations 1 and 2 for tensile strains of 0%, 1%, 2%, and 10% in the transverse direction (TD), respectively, and the results are shown in Tables 1 and 2 below.

[0114] Meanwhile, the crack density and sheet resistance increase rate shown in Tables 1 and 2 are the larger values among the measured values of the first electrode layer and the second electrode layer.

[0115] (2) Evaluation of light transmittance and haze The transparent electrode film samples of the examples and comparative examples were cut to 150 mm x 100 mm, and then the light transmittance and haze were measured using a haze meter (HM-150). The results are shown in Tables 1 and 2 below.

[0116] (3) Evaluation of surface indentation hardness The transparent electrode films of the examples and comparative examples were cut into 50 mm x 50 mm pieces, and then the surface indentation hardness of the electrode layer was measured using a nanoindident (FISHER HM500) with a load of 0.1 mN for a maximum load reaching time of 15 seconds, and the results are shown in Tables 1 and 2 below.

[0117] On the other hand, the surface indentation hardness values shown in Tables 1 and 2 are the averages of the measured values of the first electrode layer and the second electrode layer.

[0118] (4) Lightfastness evaluation The electrode layers of the transparent electrode films of the Examples and Comparative Examples were subjected to light resistance evaluation using a fader meter by irradiating light under the following conditions, and the difference in surface resistance before and after evaluation was calculated, and the results are shown in Tables 1 and 2 below.

[0119] The light irradiation conditions in the light resistance test were as follows. Equipment used: U48AU (SUGA) Light source used: Carbon arc lamp Exposure conditions: 500W / m 2 Test time: 120 hours Exposure amount: 216000kJ / m 2 Temperature: 60℃ On the other hand, the sheet resistance difference shown in Tables 1 and 2 is the larger of the measured values of the first electrode layer and the second electrode layer.

[0120] (5) Heat resistance evaluation The transparent electrode film samples of the examples and comparative examples were cut into 300 mm x 200 mm pieces, and then left in a heat-resistant oven at 80°C for 30 minutes, after which curl was measured at room temperature. After evaluating the heat resistance, the curl generated in the transparent electrode film was measured, and the results are shown in Tables 1 and 2 below.

[0121] [Table 1]

[0122] [Table 2]

[0123] Referring to Tables 1 and 2, the transparent electrode films of Examples 1 to 3 have a crack density of 0 measured at a tensile strain of 1% to 10% and a sheet resistance increase rate of 15% or less. In addition, the transparent electrode films have good results in light transmittance, haze, and heat resistance evaluations, and also have a sheet resistance increase rate of up to +52 Ω / □ in the light resistance evaluation and good surface indentation hardness, demonstrating excellent properties.

[0124] On the other hand, the transparent electrode films of Comparative Examples 1 to 3 had a maximum crack density of 0.72 and a maximum sheet resistance increase of 4,262,421% at 1% to 10% tensile strain, which was significantly higher than the Examples. In addition, the maximum sheet resistance increase value in the light resistance evaluation was +466 Ω / □, which was significantly higher than the Examples.

[0125] In view of these points, it can be seen that the transparent electrode film according to the present invention does not have a large change in crack density or surface resistance due to tensile deformation, and not only has excellent optical properties such as light transmittance or haze, but also has excellent light resistance and heat resistance. [Industrial Applicability]

[0126] The transparent electrode film according to the present invention may further reduce crack generation and sheet resistance increase rate due to external stress compared to conventional transparent electrode films.

Claims

1. a transparent substrate; and An electrode film including electrode layers disposed on both sides of the transparent substrate, The thickness of the electrode layer is 200 nm to 1,000 nm; The electrode layer has a crack density value of 0 to 0.2 when subjected to a tensile strain of 1% to 10% as calculated by the following equation 1: [Formula 1] ρ(ε)=l(ε) / A (In the above formula 1, ε is the tensile strain (%), and A is the area of the observation region (mm ２ ), where ρ(ε) is the crack density value of the electrode layer calculated at tensile strain ε, and l(ε) is the crack area (mm ２ ) means

2. The transparent electrode film according to claim 1 , wherein the electrode layer has a crack density value calculated by Equation 1 at a tensile strain of 2% of 0 to 0.

1.

3. The transparent electrode film according to claim 2 , wherein the electrode layer has a crack density value of 0 calculated by Equation 1 at a tensile strain of 2%.

4. The transparent electrode film according to claim 1 , wherein the electrode layer has a sheet resistance increase rate of 15% or less when subjected to a tensile strain of 1% to 10%, as calculated by the following equation 2: [Formula 2] δ(ε)=[{R. S(ε) / R. S(0)}-1]×100 (In the above formula 2, the δ(ε) is the sheet resistance increase rate (%) of the electrode layer calculated at the tensile strain ε, the R.S(ε) is the sheet resistance value (Ω / □) of the electrode layer measured at the tensile strain ε, the R.S(0) is the sheet resistance value (Ω / □) of the electrode layer measured in the initial state where the tensile strain is 0%, and the ε has the same meaning as in formula 1.)

5. The transparent electrode film according to claim 4 , wherein the electrode layer has a sheet resistance increase rate of 15% or less when subjected to a tensile strain of 1% as calculated by the formula 2.

6. The electrode layer has a surface indentation hardness of 150 N / mm ２ ~160N / mm ２ The transparent electrode film according to claim 1 ,

7. The transparent electrode film according to claim 1 , wherein the electrode layer has a surface resistance of 400 Ω / □ to 550 Ω / □.

8. The transparent electrode film according to claim 1 , wherein the electrode layer has a difference in surface resistance of 100 Ω / □ or less before and after light resistance evaluation.

9. 2. The transparent electrode film according to claim 1, wherein the electrode layer is manufactured using a composition for forming an electrode layer, the composition comprising: a conductive polymer; and at least one selected from the group consisting of an organic binder, an organic solvent, a silane coupling agent, and a surfactant.

10. The conductive polymer may be polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyphenylene vinylene, polyphenylene sulfide, polythienylene vinylene, polythiophene vinylene, polyfluorene, polypyrrole, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly(3,4-ethylenedioxythiophene):camphorsulfonic acid, poly(3,4-ethylenedioxythiophene):toluenesulfonic acid, poly(3,4-ethylenedioxy 10. The transparent electrode film according to claim 9, comprising one or more selected from the group consisting of polythiophene):dodecylbenzenesulfonic acid, polyaniline:polystyrenesulfonate, polyaniline:camphorsulfonic acid, polypyrrole:polystyrenesulfonate, polypyrrole:camphorsulfonic acid, polypyrrole:toluenesulfonic acid, polypyrrole:dodecylbenzenesulfonic acid, polythiophene:polystyrenesulfonate, polythiophene:camphorsulfonic acid, polythiophene:toluenesulfonic acid, and polythiophene:dodecylbenzenesulfonic acid.

11. The transparent electrode film according to claim 9 , wherein the silane coupling agent is contained in an amount of 0.05 to 0.3 wt % based on the total weight of the composition for forming an electrode layer.

12. The transparent electrode film according to claim 1 , wherein the transparent substrate comprises at least one resin selected from the group consisting of a cycloolefin resin, a cellulose resin, an acrylate resin, and a polyester resin.

13. The transparent electrode film according to claim 1 , wherein the transparent substrate has a thickness of 50 μm to 150 μm.

14. The transparent electrode film according to claim 1 , further comprising a protective film disposed on one surface of the electrode layer.

15. The transparent electrode film according to claim 14 , wherein the protective film has a peel strength of 1.0 N / 25 mm to 5.0 N / 25 mm.

16. The transparent electrode film according to claim 1 , wherein the transparent electrode film has a curl of 30 mm or less after a heat resistance test.

17. The transparent electrode film according to claim 1 , wherein the transparent electrode film has a transmittance of 85% or more.

18. The transparent electrode film according to claim 1 , wherein the transparent electrode film has a haze of 1% or less.

19. Providing a transparent substrate (S1); forming a first electrode layer on one surface of the transparent substrate (S2); forming a first protective film on one surface of the first electrode layer (S3); forming a second electrode layer on the other surface of the transparent substrate (S4); and forming a second protective film on one surface of the second electrode layer (S5); The method for producing a transparent electrode film according to claim 1 , comprising:

20. providing a transparent substrate (M1); forming a first electrode layer and a second electrode layer on both sides of the transparent substrate, respectively; and forming a first protective film and a second protective film on one surface of the first electrode layer and the second electrode layer, respectively (M3); The method for producing a transparent electrode film according to claim 1 , comprising:

21. A device comprising the transparent electrode film of any one of claims 1 to 18.

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