KR102020990B1 - Transparent electrode film for smart window, Manufacturing method thereof and PDLC smart window containing the same - Google Patents

Abstract

The present invention relates to a transparent electrode film having excellent optical characteristics and electrical stability enabling a smart window system to function as a beam projection screen, to a manufacturing method thereof, and to a PDLC smart window including the same. The transparent electrode film for a smart window includes a multi-layered composite film in which a surface antireflection thin film layer, a light diffusion film layer, a surface modified polymer film layer, an optical layer, and an ITO thin film layer are sequentially stacked.

Description

Transparent electrode film for smart window, manufacturing method thereof and PDLC smart window comprising same {Transparent electrode film for smart window, Manufacturing method etc and PDLC smart window containing the same}

The present invention relates to a transparent window film that enables a beam projection screen function in a smart window system, preferably a PDLC (Polymer Dispersed Liquid Crystal) smart window system, a method of manufacturing the same, and a smart window using the same.

It is the 'vision' that accounts for the largest proportion of the five senses of the person, and the information that the vision has makes up more than 80% of the total information. Most of the electronics we use are equipped with displays, which are actually the largest part. For this reason, investment in displays has continued, and display technology has been steadily developing for the past 60 years, and is still rapidly developing.

A transparent display is a form in which an object behind an display is visible because the area where information is displayed is transparent. This transparent display, combined with an IT converged infotainment system, delivers an amazing experience to us. That is, the interaction between the transparent display and the user becomes possible. New technologies that create a comfortable and comfortable IT environment by allowing interaction between the user and augmented reality technology, environmental information recognition technology, etc. Says technology.

The display industry is a total collection of high-tech technologies that have a strong influence on the electronics, chemicals, energy, environment and leisure markets as well as the machinery sector. Recently, with increasing resource depletion issues, increased environmental regulations, privacy protection and quality of life, high efficiency, safety, and convenience have emerged as important topics. For example, a smart window technology that can improve energy efficiency and satisfy emotion and functionality simultaneously has attracted great attention.

Smart window refers to an active control technology that can freely adjust the transmittance of light from outside to reduce energy loss and provide a pleasant environment for consumers, and can be applied to various industries such as transportation, information display, and construction. It's a technology. With a simple operation, you can induce instantaneous state transitions and add a variety of advanced convenience features. For example, office windows can be used to display meeting or schedule information, provide interactive information to a large number of users through the glass of a bus stop, provide ecosystem information to glass in an aquarium or zoo, apply to show windows, price, etc. Product information can be seen at a glance.

According to the National Renewable Laboratories (NREL) report, active control smart windows can save 10 ~ 25% of energy during summer cooling and maintain a comfortable driving environment by suppressing the temperature increase inside the vehicle during daytime parking. Companies continue to research smart window development, and some models are beginning to apply it. Looking at the technology development trend of LCD-based smart windows, polymer / liquid crystal mixtures have been studied for a long time as displays and shutter materials, and recently, they have been applied to the development of energy-saving smart windows using switch characteristics. The performance of the composite film is determined by the intrinsic properties and composition of the composition, and the polymer dispersed liquid crystal method (PDLC) and the bistable cholesteric liquid crystal (BiCh-LC) method are classified as the technologies closest to the smart window implementation.

PDLC has a structure in which micron-sized liquid crystal particles are dispersed in a polymer matrix, and controls light transmittance due to a difference in refractive index between the liquid crystal particles and the polymer due to an external voltage. The irregularly aligned liquid crystal particles in the off-state scatter scattered light due to the difference in refractive index with the polymer matrix, but when on-state, the particles are regularly oriented and induce a coincidence of the refractive index. In general, the PDLC smart window has a structure in which transparent electrode films (ITO + PET) are formed on and under the PDLC (polymer matrix + liquid crystal), as shown in a schematic cross-sectional view of FIG. 1. Currently, there is a problem in that the electrical stability is low due to low light transmittance, high sheet resistance, etc., and thus there is a limit in the application field.

Republic of Korea Patent Application Publication No. 10-2018-0118446 (Publication date October 31, 2018) Republic of Korea Patent No. 10-1577372 (Notice date 2015.12.14)

As a result of constant research, the present inventors have found that a new transparent electrode to replace the transparent electrode film (ITO + PET) formed on the upper and / or lower portion of the existing PDLC smart window in order to expand and improve the application range of the PDLC smart window. To provide a film.

The present invention for solving the above problems relates to a transparent electrode film for a smart window, a surface anti-reflection thin film layer, a light diffusion film layer, a surface-modified polymer film layer, an optical layer and an indium tin oxide (ITO) thin film layer in turn And a multi-layered composite film, wherein the surface anti-reflection thin film layer is a two- or three-layered sputtering deposition film, in which a first thin film layer having a refractive index of 1.300 to 1.700 and a second thin film layer having a refractive index of 12.000 to 2.500 are sequentially stacked or Or a first thin film layer having a refractive index of 1.300 to 1.700, a second thin film layer having a refractive index of 2.000 to 2.500, and a third thin film layer having a refractive index of 1.300 to 1.700.

In addition, an object of the present invention to provide a method for manufacturing the transparent electrode film, the first step of producing a surface-modified polymer film by plasma pre-treatment of the surface of the polymer film; Performing a roll-to-roll sputtering of the surface-modified polymer film to deposit an optical layer including a multilayer silicon oxide film having a three-layer structure; Roll-to-roll sputtering on the optical layer to deposit an ITO thin film layer to produce a first composite film in which the high-frequency film layer, the optical layer and the ITO thin film layer are sequentially stacked; A fourth step of forming a second composite film in which an optical acid film layer, a high-frequency film layer, an optical layer, and an ITO thin film layer are sequentially formed by forming an optical acid film layer under the first composite film; Roll-to-roll sputtering is formed on the light diffusion film layer of the second composite film to form a surface antireflection thin film layer having a two- or three-layer structure so that the surface antireflection thin film layer, the light diffusion film layer, the surface modified polymer film layer, the optical layer and A fifth step of manufacturing a third composite film in which the ITO thin film layers are sequentially stacked; And six steps of heat treating the third composite film.

In addition, another object of the present invention to provide a PDLC (Polymer Dispersed Liquid Crystal) smart window to which the transparent electrode film is applied.

It is another object of the present invention to provide a beam projection image screen including the PDLC smart window.

The transparent electrode film of the present invention has high light transmittance, surface stress, low haze, reflectance, and sheet resistance, and has excellent sheet resistance uniformity. In addition, the smart window to which the transparent electrode film of the present invention is applied has low driving power, excellent electrical stability, high luminance image, and can be applied to a beam projection image screen.

1 is a schematic cross-sectional view of a conventional general PDLC smart window.
2 is a schematic cross-sectional view of a transparent electrode film for a smart window of the present invention.
3 is a graph illustrating a result of measuring contact angles of polymer films according to gas concentrations and input voltages.
4A and 4B are photographs of measuring contact angles of a plasma polymerized PET polymer film according to plasma treatment conditions.
5 and 6 are AFM measurement results according to plasma treatment conditions.
7A to 7C are XPS measurement results for a PET polymer film plasma-treated under 100-300W input voltage.
8 is a measurement result of oxygen content on the surface of the PET polymer film plasma treatment according to the input voltage.
9 is a light transmittance measurement results according to the thickness of the SiO ₂ thin film carried out in Example 2.
FIG. 10 is an AFM measurement image of a SiO ₂ thin film layer having a thickness of 30 nm and 100 nm performed in Example 2. FIG.
FIG. 11 is an EDS analysis result of the deposited SiO _x thin film according to the injection gas concentration performed in Example 2. FIG.
12 is a light transmittance measurement result according to the thickness of the ITO thin film carried out in Example 2.
13A and 13B illustrate light transmittance measurement results according to refractive indices of a film composed of a PET polymer film layer-optical layer (three layers) -ITO thin film layer according to Example 2. FIG.
14A to 14D are light transmittance measurement results according to the refractive index of the SiO _x layer and the thickness of the ITO thin film.
15 is a characteristic evaluation result according to the ITO target composition implemented in Example 4. FIG.
16 is a crystalline and surface microstructure analysis data of the ITO thin film prepared from the 7.5 wt% Sn-containing target carried out in Example 4.
17 shows the evaluation results of the electro-optical properties of the ITO thin film carried out in Example 4. FIG.
18 shows crystal grain growth measurement data of a 7.5 wt% Sn target ITO thin film using a wt% Sn target according to Example 4. FIG.
19 and 20 are light reflectance and light transmittance measurement results of the surface antireflection thin film of Example 5, respectively.

The transparent electrode film (hereinafter referred to as "transparent electrode film" for smart windows) of the present invention is a schematic cross-sectional view in FIG. 2A, a surface antireflection thin film layer, a light diffusion film layer, and a surface modified polymer film layer. The optical film and the ITO thin film layer are laminated in this order in a multilayered composite film, and each layer will be described in detail below.

The surface anti-reflection thin film layer serves to improve the sharpness of an image by blocking external light, and has a multilayer structure of two or three layers in which thin film layers having different refractive indices are stacked. The surface anti-reflection thin film layer has a structure in which the first thin film layer and the second thin film layer are sequentially stacked, or the first thin film layer, the second thin film layer, and the third thin film layer are sequentially stacked, as shown in a schematic cross-sectional view in FIG. 2B.

The first thin film layer and the third thin film layer constituting the surface antireflection thin film layer may have the same or different refractive index, and may have a refractive index of 1.300 to 1.700, preferably 1.350 to 1.600, and more preferably 1.400 to 1.500. In this case, when the refractive index is less than 1.300, there may be a problem of decreasing the transmittance and reducing the role of blocking external light, and if the refractive index is more than 1.700, there may be a problem of decreasing the transmittance and blocking the external light. .

The first thin film layer and the third thin film layer may include at least one selected from SiO ₂ and MgF ₂ , and may be formed by sputter deposition.

The second thin film layer may have a refractive index of 2.000 to 2.500, preferably a refractive index of 2.200 to 2.400, and more preferably 2.300 to 2.380. In this case, when the refractive index of the second thin film layer is less than 2.000, there may be a problem of decreasing the transmittance and blocking the external light. If the refractive index exceeds 2.500, there may be a problem of decreasing the transmittance and blocking the external light. Can be.

The second thin film layer may include at least one selected from TiO ₂ , Nb ₂ O ₅ , ZrO _2, and Y ₂ O ₃ , and may be formed by sputter deposition.

The thicknesses of the first thin film layer and / or the third thin film layer constituting the surface antireflection thin film layer may be the same or different from each other, and the first thin film layer and / or the third thin film layer have an average thickness of 80 to 120 nm, preferably 85 to 115 nm, More preferably, it may be formed to 85 ~ 110nm. In addition, the thickness of the second thin film layer may be formed to an average thickness of 10 to 30nm, preferably 10 to 25nm, more preferably 10 to 20nm. In addition, the first to third thin film layers having a thickness within the range may have a low light reflectance in the visible light region.

Next, the light diffusing film layer in the configuration of the transparent electrode film serves to form an image of the beam project, it is possible to use a general light diffusing film used in the art, preferably a particle size of about 10 ~ Light diffusing film made of a transparent polymer resin containing 5 to 10% by volume of ceramic particles of 30nm may be used.

Next, the surface-modified polymer film layer in the composition of the transparent electrode film serves as a base substrate, which is a supporting member of the transparent electrode film, is made of a polymer material so as to be advantageous to be employed in a flexible light and thin miniaturized electronic device . The polymer material is polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), polycarbonate (PC), polypropylene (PP), polyvinyl chloride (PVC), polyethylene (PE), poly It may include one or more selected from methyl methacrylate (PMMA), polyamide and polyimide, preferably in polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and polymethyl methacrylate (PMMA) It may include one or more selected.

In addition, the polymer film has a problem in that the quality of the thin film is degraded during the deposition process due to the low surface energy of the polymer film. Thus, one surface or both surfaces of the polymer film are plasma-treated.

The plasma surface treatment is a mixed gas containing argon (Ar) and oxygen (O ₂ ) in a 1.8 to 3: 1 volume ratio, preferably under a mixed gas containing Ar and O ₂ in a 2.0 to 2.5: 1 volume ratio, 100 It is possible to modify the surface of the polymer film by applying an input voltage of ~ 300W, preferably 150 ~ 300W, more preferably 190 ~ 300W by plasma treatment. At this time, if the Ar and oxygen volume ratio of the mixed gas is out of the range, or the input voltage is out of the range, there is a problem that the contact angle to the pure water of the modified polymer film is increased and the oxygen content in the polymer film surface is lowered. Which means lower hydrophilicity.

The surface-modified polymer film as described above may have a contact angle with respect to pure water of 7.5 to 18.0 °, preferably a contact angle with pure water of 8.0 to 16.5 °, and more preferably 8.2 to 15.2 °.

In addition, the surface-modified polymer film may have an oxygen content of the surface of 20 to 24% by weight, preferably 21 to 24% by weight, more preferably 21.5 to 23.8% by weight.

In addition, the surface-modified polymer film may have an arithmetic mean roughness (Ra) of 0.7 to 1.25 nm and a root mean square roughness (Rq) of 0.90 to 1.55 nm, preferably Ra 1.0 to 1.2 nm and Rq of 1.30 to 1.55 nm. It may be more preferably Ra 1.05 ~ 1.20nm and Rq 1.32 ~ 1.54nm.

In addition, the surface-modified polymer film in the transparent electrode film of the present invention has an average thickness of 23 to 250 μm, preferably an average thickness of 80 to 200 μm, more preferably 100 to 200 μm. At this time, if the thickness of the surface-modified polymer film is less than 23㎛ it may be difficult to perform the function as a support member, if the thickness of the surface-modified polymer film exceeds 250㎛ the flexibility of the transparent electrode film can be reduced the application range have.

Next, the optical layer of the transparent electrode film configuration of the present invention will be described. The optical layer serves to increase optical properties such as light transmittance. As shown in a schematic cross-sectional view of FIG. 2C, the first silicon oxide layer (SiO ₂ ) and the second silicon oxide layer (SiO) are formed from the surface-modified polymer film layer. _x ) and a first silicon oxide film (SiO ₂ ) in a multilayered silicon oxide film.

The first silicon oxide film and the second silicon oxide film have different refractive indices, but the first silicon oxide film has a refractive index of 1.40 to 1.50, and preferably a refractive index of 1.42 to 1.48. The refractive index of the second silicon oxide film is larger than that of the first silicon oxide film. As a specific example, when both the first silicon oxide film and the second silicon oxide film have an average thickness of 5 nm, and the refractive index of the first silicon oxide film is 1.40 to 1.50, the refractive index of the second silicon oxide film is 0.02 than the refractive index of the first silicon oxide film. ~ 0.20 larger, preferably 0.05 to 0.15 larger than the refractive index of the first silicon oxide film, more preferably 0.05 to 0.10 larger than the refractive index of the first silicon oxide film, the broad light transmittance of 380 ~ 800nm wavelength It is advantageous from the side.

The first silicon oxide film has an average thickness of 4 nm to 60 nm, preferably 4 nm to 40 nm, and more preferably 4 nm to 30 nm in view of light transmittance and low surface resistance.

Further, the second silicon oxide film is preferably 4 nm to 25 nm, preferably 4 nm to 20 nm, and more preferably 4 nm to 15 nm in view of light transmittance and productivity.

The first silicon oxide film and the second silicon oxide film may be formed by sequentially depositing the upper portion of the polymer film layer by roll-to-roll sputtering, and in particular, the second silicon oxide film may be formed by adjusting the amount of argon and oxygen injection. In addition, the Si and O content (at%) of the formed second silicon oxide film is 15 to 30%, preferably 20 to 30%, more preferably 25, of the SiO _x thin film calculated by Equation 1 below. ~ 30% can be satisfied. At this time, when the oxygen ratio in the second silicon oxide film is less than 15% or more than 30%, there may be a problem that the light transmittance of the optical layer including the first and second silicon oxide film is lowered.

[Equation 1]

% Oxygen in SiO _x Thin Film = {Oxygen in SiO _x Thin Film at% / (Si at _x Si _x thin film + oxygen at SiO _x thin film at%)} × 100%

The first silicon oxide film has a surface roughness of 0.700 to 1.120 nm in arithmetic mean roughness (Ra), a square average roughness (Rq) of 0.800 to 1.300 nm, preferably Ra of 0.720 to 1.050 nm, and Rq of 0.820 to 1.430, more preferably Ra is 0.720 ~ 0.860nm, Rq may be 0.820 ~ 1.230.

Next, the ITO thin film layer of the transparent electrode film of the present invention is the initial vacuum (1.0 ~ 4.0) × 10 ^-6 torr, process vacuum (5.0 ~ 9.0) × 10 ^-4 torr, Ar and O ₂ injection ratio of 270 ~ By using a target material containing tin (Sn) content of 6.0 to 8.5% by weight under the conditions of a deposition gas ratio of 300 sccm and 4 to 8 sccm, preferably initial vacuum (1.5 to 3.0) × 10 ^-6 torr, process A target containing from 7.0 to 8.0% by weight of tin (Sn) under the conditions of vacuum (6.0 to 8.0) x 10 ^-4 torr, a mixture gas ratio for deposition of Ar and O ₂ of 280 to 300 sccm and 4.5 to 6.5 sccm By using a material, it may be formed by depositing on the optical layer by RF magnetron sputtering.

The formed ITO thin film layer may have an average thickness of 10 to 30 nm, preferably 15 to 25 nm, and more preferably 17 to 23 nm.

The transparent electrode film of the present invention described above can be manufactured by the following method.

Plasma pretreatment of the surface of the polymer film to produce a surface-modified polymer film; Performing a roll-to-roll sputtering of the surface-modified polymer film to deposit an optical layer including a multilayer silicon oxide film having a three-layer structure; Three steps of manufacturing a first composite film by depositing an ITO thin film layer by sputtering roll-to-roll on the optical layer; Forming a second optical film by forming an optical acid film layer on the lower portion of the first composite film; Manufacturing a surface third composite film by forming a surface anti-reflection thin film layer having a two- or three-layer structure by roll-to-roll sputtering on the light diffusion film layer of the second composite film; And a six step of heat treating the third composite film.

The polymer film of the first step is as described above. And, the plasma pretreatment is a mixed gas containing argon (Ar) and oxygen (O ₂ ) in a 1.8 to 3: 1 volume ratio, preferably under a mixed gas containing Ar and O ₂ in a 2.0 to 2.5: 1 volume ratio, The surface of the polymer film may be modified by plasma treatment by applying an input voltage of 100 to 300W, preferably 150 to 300W, more preferably 190 to 300W.

Roll-to-roll sputtering in the step 2, the applied voltage 5 ~ 12kW, preferably applied voltage 7 to under 10kW atmosphere, while the change in oxygen injection ratio in the injection ratio is 150 ~ 200sccm, and 80 ~ 120sccm range of Ar and O _2, molecular The first silicon oxide film (SiO ₂ ), the second silicon oxide film (SiO _x ), and the first silicon oxide film (SiO ₂ ) may be sequentially deposited from the film surface. The physical properties and characteristics of each layer of the optical layer are as described above.

In addition, the first composite film of the third step is a form in which a high-frequency film layer, an optical layer and an ITO thin film layer are sequentially stacked. In addition, the ITO thin film layer is an initial vacuum (1.0 ~ 4.0) × 10 ^-6 torr, process vacuum (5.0 ~ 9.0) × 10 ^-4 torr, the mixing ratio of the deposition of Ar and O ₂ 270 ~ 300sccm and 4 ~ 8sccm using a target material comprising the gas under the condition non-tin (Sn) content of 6.0 ~ 8.5% by weight, preferably from an initial vacuum ^{(1.5 ~ 3.0) × 10 -6} torr, the vacuum step (6.0 ~ 8.0) × 10 ^- RF magnetron sputter method using a target material containing a tin (Sn) content of 7.0 to 8.0% by weight under the conditions of ⁴ torr, Ar and O ₂ injection ratio of 280 ~ 300sccm and 4.5 ~ 6.5sccm It can be formed by depositing on the optical layer.

In addition, the second composite film of the fourth step is a form in which the optical acid film layer, the high-frequency film layer, the optical layer and the ITO thin film layer are sequentially stacked. The optical acid film layer may be formed by wet coating.

In addition, the third composite film of the fifth step is a form in which the antireflection thin film layer, the light diffusing film layer, the surface-modified polymer film layer, the optical layer and the ITO thin film layer are sequentially stacked as shown in FIG. .

The anti-reflection thin film layer is a first thin film layer having a refractive index of 1.300 to 1.700 and a second thin film layer having a refractive index of 2.000 to 2.500 are sequentially stacked; or a first thin film layer having a refractive index of 1.300 to 1.700, a second thin film layer having a refractive index of 2.000 to 2.500 and a refractive index The first thin film layer of 1.300 ~ 1.700 may be laminated in sequence;

The first to third thin film layers may be formed by depositing by performing a roll-to-roll sputtering process.

In the case where the first thin film layer and / or the third thin film layer are SiO ₂ thin films, an operating vacuum (3.5 to 4.5) × 10 ⁻³ torr, and an injection ratio of Ar and O ₂ is 550 to 650 sccm and 50 to 80 sccm, Conditions, the applied power 3.5 ~ 5kW, voltage 320 ~ 380V, current 11.50 ~ 13.00A, drum temperature room temperature (15 ~ 35 ℃), roll speed 0.8 ~ 1.2m / min can be deposited as the target material (Si) . Of course, in the case of MgF ₂ thin film, the target material and the specific process conditions will be different.

In addition, in the case of the TiO ₂ thin film, the second thin film layer has an operating vacuum (3.5 to 4.5) × 10 ⁻³ torr, a condition for the deposition gas mixture having an injection ratio of Ar and O ₂ of 550 to 650 sccm and 30 to 55 sccm, and an applied power of 0.8 ~ 1.5kW, voltage 400 ~ 460V, current 2.0 ~ 3.0A, drum temperature can be deposited as a target material (Ti) under the conditions of room temperature (15 ~ 35 ℃), roll speed 0.8 ~ 1.2m / min. Of course, for Nb ₂ O ₅ , ZrO ₂ and Y ₂ O ₃ the target material and specific process conditions will be different.

In addition, the heat treatment of the six steps may be performed for 30 to 90 minutes at 140 ~ 200 ℃, preferably 140 ~ 180 ℃, more preferably 145 ~ 170 ℃.

The transparent electrode film of the present invention having the structure as described above may have a sheet resistance of 100 Ω / cm ² or less, preferably 60 ~ 100 Ω / cm ² , more preferably 70 ~ 100 Ω / cm ² .

In addition, the transparent electrode film of the present invention may have a surface resistance uniformity of -5.0 to 5.0%, preferably -4.0 to 4.0%, more preferably -2.5 to 2.5%.

In addition, the transparent electrode film of the present invention, when measured according to JIS K 7105, light transmittance of 90 to 95% and haze 8.0 to 18.0%, preferably light transmittance of 90 to 94.5% and haze 8.0 to light of 550nm wavelength ~ 16.0%, more preferably 90.50 ~ 94.00% light transmittance and 8.0 ~ 13.5% haze.

In addition, the transparent electrode film of the present invention may have a light reflectance of 5 to 9%, preferably 5.5 to 8.5%, more preferably 5.5 to 7.0%.

In addition, the transparent electrode film of the present invention may have a contrast ratio of 100: 1 or more, preferably a contrast ratio of 105 to 120: 1, more preferably 110 to 120: 1.

Such, the transparent electrode film of the present invention having excellent optical properties is suitable for applying to the PDLC smart window, for example, a transparent electrode film; A liquid crystal layer formed on the ITO thin film layer of the transparent electrode film; An ITO thin film layer formed on the liquid crystal layer; It can be applied to the PDLC smart window of the structure including; polymer film layer formed on the ITO thin film layer.

In addition, the smart window may be applied to the beam projection image screen.

Hereinafter, the present invention will be described in more detail based on Examples. However, the following examples should not be construed as limiting the scope of the present invention.

EXAMPLE

Example 1 Surface Modification Optimization Condition of Polymer Film

As a substrate material of the transparent electrode film, many polymer films with excellent flexibility and easy processing are used. However, the low surface energy characteristics of the polymer film cause the quality of the thin film during the deposition process. In order to introduce the excellent polymer film to the present invention through the experiment was performed to derive the optimum plasma surface treatment conditions.

PET (Polyethylene terephthalate) film (manufacturer: Kimoto, trade name: G90AB) was prepared. The chemical structure of PET polymer film mainly includes chemical structures of C = O, C-O, C-C, and C-H. The use of oxygen in plasma treatment is expected to increase the binding of C = O and C-O. The C = O and C-O bonds were very high in dipole moments and increased through plasma surface treatment, and thus the hydrophilic properties of the C = O and C-O bonds could be modified.

Plasma surface treatment was performed using a pretreatment plasma treatment equipment attached to a roll-to-roll sputter equipment (manufacturer: Seokwon, trade name: RTR1), and the mixed gas was subjected to plasma with Ar and Ar + O ₂ . It was formed to perform a surface treatment of the polymer substrate.

The total amount of gas used in the plasma treatment process is 800 sccm, which is performed by changing the volume ratio of Ar: O ₂ in 1: 0, 5: 1, 3: 1, 2: 1, and changing the input voltage (W) from 0 to 300W in 50W units. It was.

(1) contact angle measurement

After the plasma surface treatment, the contact angle formed between the surface of the PET polymer film plasma-treated with a contact angle measuring device and the droplet surface was measured. After taking the shape of the droplets with a CCD camera, the method of calculating the interfacial tension (γ) optimized for the shape of the finally taken droplets was used. The injection volume was set to 0.05 mL through a micro syringe and secondary distilled water was used. Since the contact angle may cause an error, in the experiment, the contact angle was measured in the range that the error range did not exceed ± 2 ° up to 10 times or more.

The result of the contact angle measurement according to the gas concentration and the input voltage is shown in FIG. 3. In FIG. 4A, the PET polymer film (bare PET) without plasma treatment, and the intensity of 100 W, 200 W and 300 W under a volume ratio of Ar: O ₂ = 2: 1 The contact angle measurement photograph of the plasma-treated PET polymer film is shown. And, Figure 4b is a photograph of the contact angle measurement of the PET polymer film plasma-treated under oxygen-free argon gas.

Referring to FIG. 3, in the case of the plasma surface treatment using the Ar and O ₂ mixed gas, the result of the plasma surface treatment using Ar alone was almost similar to that of the plasma experiment using only Ar. However, as the input voltage increased, the contact angle decreased continuously as the amount of oxygen in the mixed gas increased. Especially, when the input power was 200W under the Ar: O ₂ = 2: 1 volume ratio, the contact angle was 10.1 ° and 300W. Under the conditions, it was confirmed that the surface modification was changed to the lowest value of 8.5 ° superhydrophilic property.

(2) surface roughness measurement

In addition, the surface roughness of the polymer film subjected to plasma surface treatment with a mixed gas of Ar: O ₂ = 2: 1 volume ratio was measured by a non-contact Atomic Force Microscope (AFM), and the results are shown in FIGS. 1 is shown. The measurement results show that the surface roughness increases as the input power increases.

Input voltage Arithmetic Mean Roughness (Ra) Squared mean roughness (Rq) 50 W 0.67 0.86 100 W 0.73 0.94 150 W 1.09 1.37 200 W 1.11 1.42 250 W 1.16 1.48 300 W 1.20 1.52

5 and Table 1, the PET polymer film has an arithmetic mean roughness (Ra) of 0.7 to 12.5 nm when the plasma treatment under Ar: O ₂ = 2: 1 volume ratio and 100 ~ 300W input voltage conditions, the square average roughness ( Rq) was confirmed to have a degree of 0.90 ~ 1.55nm.

(3) XPS surface analysis

In addition, XS-ray photoelectron spectroscopy (XPS) surface analysis was performed to determine the functional group according to the oxygen plasma surface treatment of the surface, and the input power was 100W, 200W and 300W under Ar: O ₂ = 2: 1 volume ratio. XPS measurement results for the plasma polymerized PET polymer film were shown in A (100W), B (200W), and C (300W) of FIG. 7, respectively. The results of measuring the oxygen concentration are shown in FIG. 8 and Table 2 below.

Input voltage 50 W 100 W 150 W 200 W 250 W 300 W Oxygen concentration (% by weight) 18.8 20.3 21.6 21.9 22.4 23.8

8 and Table 2, when the plasma treatment with an input power of 100 ~ 300W input voltage in the Ar: O ₂ = 2: 1 volume ratio conditions, the oxygen content in the surface of the polymer film at a high concentration of about 20 to 24% by weight It was confirmed to include.

Through Example 1, the polymer film is a mixed gas containing argon (Ar) and oxygen (O ₂ ) in a 1.8 to 3: 1 volume ratio, preferably Ar and O ₂ in a 2.0 to 2.5: 1 volume ratio Under the mixed gas, when plasma treatment is performed under an input voltage range of 100 to 300 W, preferably 150 to 300 W, hydrophilic reforming is possible by increasing oxygen content in the polymer film, and deposition deposition effect is increased by increasing surface roughness. I could see that you can see.

Example 2 Optical Layer Optimal Structure Design

In order to design the optimum conditions of the structure, refractive index, and thickness of the Si-based oxide thin film of the multilayer structure, the following simulation was performed.

(1) Investigation of characteristics according to thickness, sheet resistance and roughness

The electrical properties of the ITO thin film were investigated through the thickness and roughness of the silicon oxide thin film, and an experiment was performed to set the optimum SiO ₂ formation conditions.

The flow rate of the reaction gas was a micro flow rate automatic control valve MFC, and the reaction gas was Ar (4N), O ₂ (4N), Ar + O ₂ mixed gas (Ar: O ₂ = 2: 1, 4N). , was the experiment by the thickness of the SiO ₂ thin film in order to identify the characteristics of the ITO thin film, with varying thickness up to 10 ~ 100nm of SiO ₂ thin film PET polymer film layer, the optical layer (first layer, SiO ₂₎ thin film layer -ITO The light transmittance experiment was performed, and the results are shown in FIG. 9 and Table 3 below. At this time, the light transmittance measured the light transmittance in 380-780 nm and 550 nm by JISK7105, and shows an average value.

In this case, the PET polymer film is a PET polymer film subjected to the plasma treatment of Example 1 (Ar: O ₂ = 2: 1 volume ratio, input voltage 200W). Bare PET of Table 3 is a plasma-treated PET polymer film is not deposited with SiO ₂ , the rest is deposited by varying the thickness of SiO ₂ on the plasma-treated PET polymer film.

Light wavelength
(Light transmittance%) Bare PET SiO ₂
(10nm) SiO ₂
(20nm) SiO ₂
(30nm) SiO ₂
(40nm) SiO ₂
(50 nm) (380 ~ 780 nm)
Average 90.55 86.52 87.30 87.32 87.26 87.90 550nm 91.67 86.89 87.70 88.59 89.21 89.15 Light wavelength
(Light transmittance%) - SiO ₂
(60nm) SiO ₂
(70nm) SiO ₂
(80nm) SiO ₂
(90nm) SiO ₂
(100 nm) (380 ~ 780 nm)
Average - 87.31 84.46 85.63 85.70 84.28 550nm - 87.44 85.18 86.39 86.30 85.34

Referring to FIG. 9 and Table 3, after forming 25 nm of ITO on each thin film having a SiO ₂ thin film layer of 10 to 100 nm, the transmittance data shows that the average transmittance of the thin film having a SiO ₂ thin film layer having a thickness of 20 to 60 nm is shown. It showed the best characteristics.

In addition, the surface resistance of the PET polymer film layer-optical layer (1 layer, SiO ₂ ) -ITO thin film layer was measured, and the results are shown in Table 4 below. In this case, the surface resistance is measured using a four-point surface resistance meter.

In addition, the roughness of the SiO ₂ thin film layer corresponding to the outermost surface of the PET polymer film layer-optical layer (1 layer, SiO ₂ ) without ITO was measured according to the thickness, and the results are shown in Table 5 below. It was. In addition, AFM measurement images having a thickness of 30 nm and 100 nm of the SiO ₂ thin film layer are shown in FIG. 10.

Surface Resistance (Ω / cm ² ) SiO ₂ (10 nm) SiO ₂ (20 nm) SiO ₂ (30 nm) SiO ₂ (40 nm) SiO ₂ (50 nm) Primary 190 189 188 209 200 Secondary 185 201 198 203 195 3rd 180 199 189 202 193 4th 184 208 199 196 198 5th 186 209 201 208 201 Average 185 201.2 195 203.6 197.4 Surface Resistance (Ω / cm ² ) SiO ₂ (60 nm) SiO ₂ (70 nm) SiO ₂ (80 nm) SiO ₂ (90 nm) SiO ₂ (100 nm) Primary 209 208 201 207 212 Secondary 206 204 209 208 207 3rd 198 200 211 212 210 4th 202 202 205 208 208 5th 204 206 208 210 211 Average 203.8 204 206.8 209 209.6

ITO / PET of Table 5 is to form an ITO thin film layer on the plasma-treated PET polymer film not deposited SiO ₂ , the rest of the deposition on the plasma-treated PET polymer film by varying the thickness of SiO ₂ .

division Rq (nm) Ra (nm) ITO / PET 2.175 1.686 SiO ₂ (10nm) / PET 0.841 0.741 SiO ₂ (20nm) / PET 0.923 0.817 SiO ₂ (30nm) / PET 1.287 0.901 SiO ₂ (40nm) / PET 1.423 1.022 SiO ₂ (50nm) / PET 1.612 1.189 SiO ₂ (60nm) / PET 1.270 1.109 SiO ₂ (70nm) / PET 1.344 1.137 SiO ₂ (80nm) / PET 1.911 1.611 SiO ₂ (90nm) / PET 1.643 1.391 SiO ₂ (100nm) / PET 1.962 1.642

In the case of surface resistance, the surface resistance of the transparent electrode film having a thickness of SiO ₂ of 30 nm was the best. The surface resistance was affected by the roughness of the interface between SiO ₂ and ITO, and the surface roughness was poor. In this case, the electron transfer in the ITO thin film is affected and the scattering phenomenon occurs and the surface resistance is not good.

(3) multilayer silicon oxide (SiO) ₂ / SiO _x / SiO ₂ Optimal Design of Optical Layer

After securing the optimum composition of the SiO _x thin film by changing the composition of the oxide through the deposition, the experiment was conducted to secure the optimum transmittance by forming the SiO ₂ / SiO _x / SiO ₂ thin film in a three-layer structure.

RF magnetron sputter was used as a method of manufacturing the SiO _x thin film, and the target was deposited using a SiO _x 4N target by using a ratio of Ar and O ₂ , which are injection gases, as a mixed gas (total flow rate of 200 sccm). SiO ₂ and SiO _x thicknesses were applied using the simulation results.

EDS analysis results of the deposited SiO _x thin film according to the injection gas concentration are shown in FIG. 11.

In addition, by _measuring the oxygen concentration of the injection gas, the oxygen transmittance (%) of the SiO _x thin film according to Equation 1 and the light transmittance measurement according to the thickness of the ITO thin film were measured, and the results are shown in FIG. 12 and Table 4 below. .

[Equation 1]

% Oxygen in SiO _x Thin Film = {Oxygen in SiO _x Thin Film at% / (Si at _x Si _x thin film + oxygen at SiO _x thin film at%)} × 100%

Oxygen ratio of SiO _x thin film 10 nm thick ITO ITO thickness 15nm ITO thickness 20nm ITO thickness 25nm 15% 87.843 90.23 94.22 92.40 20% 87.99 90.33 94.39 92.53 25% 88.07 90.35 94.50 92.57 30% 88.07 90.29 94.54 92.53

When the thickness of the ITO thin film was 20 nm, the oxygen ratio of the deposited SiO _x thin film showed excellent light transmittance characteristic of 90% or more from 10 to 30%, but slight haze occurred in the 10% and 15% thin film. It was.

In addition, in FIG. 12, in which the element ratios of O and Si were measured through EDS analysis of the manufactured thin film, it was found that X was less than 2 in SiO _x and oxygen ratio was 20 in the case of 10 to 15% oxygen ratio. In the thin film of more than%, it can be seen that X is close to 2. This is considered that O does not bond with oxygen in Si = O double bonds, resulting in voids, which affects haze and transmittance.

In addition, when measuring the light transmittance of the SiO ₂ / SiO _x / SiO ₂ thin film at 10 to 25nm of ITO thin film, the lowest transmittance was shown at 10nm thick of ITO thin film and 94% or more at 20nm of ITO thin film. . The best overall transmittance was obtained at 25% and 30% oxygen ratio. Overall, the ITO thin film thickness is about 15 to 25 nm, preferably about 18 to 23 nm, and the oxygen ratio in SiO _x is 15 to 30%. Preferably, when the thin film was formed under the process conditions of 20 to 30%, it was confirmed that the best transmittance could be obtained.

(4) refractive index simulation

Examples plasma treatment of _{1 (Ar: O 2 = 2} : 1 volume ratio, the input voltage 200W) the PET by performing sputter deposition on a polymer film, SiO ₂ film, SiO _x thin film, SiO was laminated as the _second thin film turn, sputtering Deposition was performed to form a 25 nm thick ITO thin film.

The light transmittance according to the refractive index of the film composed of PET polymer film layer-optical layer (three layers) -ITO thin film layer was measured by using the McCloud program when the SiO ₂ thin film and the SiO _x thin film were formed at 10 nm and 15 nm, respectively. The results are shown in FIGS. 13A and 13B.

Simulation results showed that the SiO _x thin film with refractive index 1.6 was inserted into the intermediate layer in the ITO (25 nm) / SiO ₂ (10 nm) / SiO _x (10 nm) / SiO ₂ (10 nm) / PET structure. Showed characteristics.

In addition, each thin film of the optical layer was formed to have a refractive index and a thickness as described below.

When the SiO ₂ thin film thickness 5nm and the refractive index = 1.5, the SiO _x thin film thickness 5nm and the refractive index = 1.5, the ITO thickness 15 ~ 25nm, the light transmittance is shown in Figure 14a.

In addition, when the SiO ₂ thin film thickness 5nm and the refractive index = 1.5, the SiO _x thin film thickness 5nm and the refractive index = 1.65, when the ITO thickness 15 to 25nm, the light transmittance is shown in Figure 14b.

In addition, when the SiO ₂ thin film thickness 5nm and the refractive index = 1.5, the SiO _x thin film thickness 5nm and the refractive index = 1.80, the ITO thickness 15 to 25nm, the light transmittance is shown in Figure 14b.

In addition, when the SiO ₂ thin film thickness 5nm and the refractive index = 1.5, the SiO _x thin film thickness 5nm and the refractive index = 1.95, the ITO thickness 15 to 25nm, the light transmittance is shown in Figure 14c.

According to the simulations, the ITO thin films were formed at 15, 20, and 25 nm at each refractive index, and the light transmittance of the transparent electrode substrate having a SiO _x of 1.5 and an ITO thickness of 15 nm was 92.58% at 500 nm. The average light transmittance from 380 to 800 nm was obtained at 93.21%.

In addition, the light transmittance of the transparent electrode substrate having a SiO _x refractive index of 1.5 and ITO thickness of 20 nm showed a light transmittance of 91.08% at 500 nm, and an average light transmittance of 380 to 800 nm was obtained at 88.31%.

In addition, the light transmittance of the transparent electrode substrate having a SiO _x refractive index of 1.5 and ITO thickness of 25 nm showed a light transmittance of 89.27% at 500 nm, and an average light transmittance of 380 to 800 nm was 86.79%.

Similarly, the 500 nm light transmittance and the average light transmittance are 92.02% and 89.44% light transmittance when the thickness of ITO is 15nm and the refractive index of SiO _x is 1.65, and the thickness of ITO is 15nm when the refractive index of SiO _x is 1.8. The light transmittances of 91.60% and 89.29% were obtained when the refractive index of SiO _x was 1.95, and the light transmittances of 91.1% and 89.1% were obtained when the thickness of ITO was 15 nm.

When judged, when the index of refraction of the optical layers within the SiO _x 1.50 ~ 1.65, yet, one is ITO thickness of 15 ~ 25nm, it exhibited a rating of excellent light transmittance.

Example 4 ITO Deposition Conditions Design

(1) The optical and electrical characteristics of the ITO transparent electrode film according to the Sn component of the ITO target were tested.

The deposition process conditions were initial vacuum 2.0 × 10 ^-6 torr, process vacuum 7.0 × 10 ^-4 torr, ratio of mixed gas (Ar: O ₂ sccm) used for ITO deposition = 290: 6, crystallization heat treatment of ITO thin film at temperature 150 It carried out at 60 degreeC and holding time 60 minutes.

As a result of manufacturing conditions and electrical and optical characteristics evaluation of the ITO thin film, the sheet resistance was improved with increasing Sn content of the ITO target, and the transmittance was almost constant. The sheet resistance of the ITO thin film containing 10wt% Sn was the best among the prepared thin films. However, as a result of acid resistance test, which was immersed in 1% HCl solution for 15 minutes, the sheet resistance of the ITO thin film prepared with 10 wt% Sn-ITO target was not measured. It is believed that this was etched into the acid solution due to the lack of crystallization. Therefore, ITO thin film production in the range of 80 ~ 120Ω / cm ² sheet resistance was determined to be the most suitable to use 7.5% by weight-ITO target, the process conditions using two targets, the applied power was 3.8kW each .

The characteristics evaluation results according to the target composition are shown in FIG. 15.

In addition, crystallinity and surface microstructure analysis of the ITO thin film after heat treatment was performed. As a result of characterization of the ITO thin film prepared with the 7.5 wt% Sn-containing target, the (222) plane and the (440) plane, which are the crystalline main peaks of the ITO component, were detected, and ITO grains having a size of about 30 nm were present (Fig. 16).

(2) Growth experiment of ITO thin film crystal grain

ITO thin films have a difference in crystallinity under the same conditions depending on the Sn component. As a result of the previous study, it was found that the smaller the amount of Sn contained in the ITO, the higher the crystallinity and the faster the grain growth under the same heat treatment conditions. Therefore, ITO was used to promote crystal growth of Sn-rich ITO thin films using Sn-less Sn.

Process conditions and crystallinity test: initial vacuum 2.0 × 10 ^-6 torr, process vacuum 7.0 × 10 ^-4 torr, mixed gas (Ar: O ₂ sccm ratio = 290: 5.4, heat treatment 150 ° C, 60 minutes, acid test (crystallization) ) Was immersed in 1 wt% HCl solution for 15 minutes.

And the electrical and optical characteristic evaluation result about the manufactured ITO thin film is shown in FIG.

Through the acid test, it was confirmed that all the ITO thin films prepared with the target containing 7.5 wt% Sn (1 layer) and 3 wt% Sn (2 layer) were crystallized, and the target containing 7.5 wt% and 10 wt% Sn was used. The prepared two-layer ITO thin film was not crystallized. It was found that the particle growth promoting effect using the ITO target containing 3% by weight Sn occurs. Then, the grain structure of the 7.5 wt% Sn target ITO thin film using the 3 wt% Sn target was dense and particles of about 200 nm or more were observed (see FIG. 18).

Example 5 surface antireflection thin film

Using a 300 mm roll-to-roll sputter system, a TiO ₂ thin film and a SiO ₂ thin film were sequentially deposited on a PET polymer film subjected to the plasma treatment (Ar: O ₂ = 2: 1 volume ratio, input voltage 200W) of Example 1 in two layers. A surface antireflective thin film was formed.

In this case, SiO ₂ layer and TiO ₂ thin film formation conditions are shown in Table 7 below. The refractive index of the formed TiO ₂ thin film is 2.348, and the refractive index of the SiO ₂ thin film is 1.461.

RTR equipment initial condition T-S distance (mm) Drum temperature (℃) Initial vacuum (Torr) 80 Room temperature 8.0 * 10 ^-6

TiO ₂ thin film manufacturing process conditions Power Ar / O ₂ Vacuum operation Voltage Current Roll speed coating Drum temperature kw sccm Torr V A m / min collection ℃ 1.0 600/40 3.7 × 10 ^-3 434 2.3 1.0 1.0 Room temperature

SiO ₂ thin film manufacturing process conditions Power PEM (Oxygen Input Control Device) power supply Vacuum operation Roll speed coating Drum temperature kw (Si)%, Ar / O ₂ Current (A) / Voltage (V) Torr m / min collection ℃ 4 10 (600/60) 12.10 / 365 3.7 × 10 ^-3 1.0 3 Room temperature PEM: Oxygen input regulator, DDR: Coating rate

The thickness of the TiO ₂ thin film (10 nm) was fixed to change the thickness of the SiO ₂ thin film, which is a low refractive index material, and the optimum reflectivity was confirmed. As a result, the SiO ₂ (100 nm) thin film having the lowest reflectance in the visible region was confirmed. . And its light reflectance and light transmittance were measured, and the results are shown in FIGS. 19 and 20, respectively.

Looking at the reflectance measurement results of FIG. 20, it can be seen that as the light wavelength increases, a tendency to have a low light reflectance, and the light reflectance of 9.7% or less from 560 ~ 570nm or more. In addition, it was confirmed that the excellent light transmittance of more than 90% from 560 ~ 570nm.

Preparation Example 1

The PET polymer film (thickness 188 um) was plasma-treated in the same manner as in Example 1 using a plasma processing equipment for pretreatment attached to a roll-to-roll sputtering equipment (manufacturer: Seokwon, trade name: RTR1). Ready.

Next, sputtering was performed using a roll-to-roll sputtering equipment (manufacturer: Seokwon, trade name: RTR1) according to the applied power 8W and the Ar: O ₂ ratio using three Si targets, and a SiO ₂ thin film layer (5 nm thick) / An SiO _x thin film layer (thickness 5 nm) / SiO ₂ thin film layer (thickness 5 nm) was formed on one surface of the plasma polymerized PET polymer film with a three-layered optical layer. At this time, the refractive index of the SiO ₂ thin film layer of the optical layer is 1.5, and the refractive index of the SiO _x thin film layer is 1.65.

Next, a 15 nm-thick ITO thin film was formed on the optical layer of the film in which the PET polymer film layer and the optical layer were sequentially laminated using the roll-to-roll sputtering equipment. At this time, the ITO thin film was used two ITO target containing 7.5 wt% Sn, roll to roll sputtering process was carried out at 2.0m / min. At this time, the vacuum in the chamber of the roll-to-roll sputtering equipment was initially 2.0 × 10 ⁻⁶ torr, and the process vacuum degree was 7.0 × 10 ⁻⁴ torr.

After the ITO deposited film was formed, the oxygen ratio (%) of the SiO _x thin film measured by the following Equation 1 was about 24.8%.

[Equation 1]

% Oxygen in SiO _x Thin Film = {Oxygen in SiO _x Thin Film at% / (Si at _x Si _x thin film + oxygen at SiO _x thin film at%)} × 100%

Next, an optical film layer (manufacturer: Kimoto, trade name GN7B) having a thickness of 750 nm was formed on the bottom surface of the PET polymer film of the PET polymer film layer-optical layer-ITO thin film layer by wet coating.

Next, a SiO ₂ thin film / TiO ₂ thin film / SiO ₂ thin film was sequentially formed under the conditions of Tables 7 to 9 of Example 5 by using a 300 mm roll-to-roll sputter system on one surface of the light diffusion film layer that is the lowest film. It was formed to form a three-layer surface antireflection thin film, wherein the refractive index of the TiO ₂ thin film is 2.348, the refractive index of the SiO ₂ thin film was 1.461. The thickness of the SiO ₂ thin film was 100 nm and the thickness of the TiO ₂ thin film was 10 nm.

Next, the multilayered film was heat-treated at 60 ° C. under atmospheric pressure for 60 minutes to provide a surface antireflective thin film layer, a light diffusion film layer, a surface-modified polymer film layer, an optical layer, and ITO having a structure as shown in FIG. 2. A transparent electrode film in which a thin film layer was sequentially stacked was manufactured.

Preparation Example 2 to Preparation Example 12

In the same conditions as in Preparation Example 1 by using a roll-to-roll sputter equipment to prepare a transparent electrode film of the same structure to carry out Preparation Examples 2 to 11, respectively, when manufacturing the optical layer of the three-layer structure, To change the applied voltage and the gas injection ratio as shown in Table 10 to form an optical layer to prepare a transparent electrode film of a multi-layer structure, respectively.

division Optical layer deposition condition ITO Deposition Conditions Applied voltage
(kW) Gas injection fee
(Ar / (O ₂ / O ₂ / O ₂ , sccm) ITO target Applied voltage Gas injection fee
(Ar / O ₂ , sccm) Preparation Example 1 8/8/8 160 / (100/100/100) 7.5 weight% tin 3.8 290 / 6.0 Preparation Example 2 160 / (100/80/100) Preparation Example 3 160 / (100/60/100) Preparation Example 4 5/5/5 160 / (100/100/100) Preparation Example 5 160 / (100/80/100) Preparation Example 6 160 / (100/60/100) Preparation Example 7 10/10/10 160 / (100/100/100) Preparation Example 8 160 / (100/80/100) Preparation Example 9 160 / (100/60/100) Preparation Example 10 12/12/12 160 / (100/100/100) Preparation Example 11 160 / (100/80/100) Preparation Example 12 160 / (100/60/100) * 8/8/8 applied voltage is applied by means gahaetdaneun 8kW power at the time of roll-to-roll deposition in turn, the SiO ₂ thin films -SiO _x -SiO ₂ film.
Ar * / (O ₂ / O ₂ / O ₂₎ ratio is 160 (100/80/100) expression SiO ₂ film -SiO _x -SiO during roll-to-roll thin-film deposition process as the thin film ₂ in turn, the injection gas is SiO when there is a _second thin film deposition means that using the Ar / O ₂ = 160sccm / 100sccm, and when SiO _x thin film deposited using the _{Ar / O 2 = 160sccm / 80sccm} .

Experimental Example 1 Measurement of Physical Properties of Transparent Electrode Film

The sheet resistance, transmittance and chromaticity (b *) of the transparent electrode films of Preparation Examples 1 to 12 were measured, and the results are shown in Table 11 below. In addition, the sheet resistance uniformity, haze, and light reflectance after heat treatment of the transparent electrode film are shown in Table 12.

The sheet resistance was measured using a four-point sheet resistance meter according to the KS L1619 method, and the sheet resistance uniformity was measured using the four-point sheet resistance meter according to the KS L1619 method. The average resistance of the values is shown.

The light transmittance measured the light transmittance in 380-780 nm by JISK7105, and shows the average value thereof.

Light reflectance, chromaticity and haze were measured by the light transmittance measuring device (Minolta 3600D) by the ASTM D1003 method.

division Surface Resistance (Ω / cm ² ) % Light transmittance Chromaticity (b *) Before heat treatment After heat treatment Before heat treatment After heat treatment Before heat treatment After heat treatment Preparation Example 1 205 90 83.3 86.5 3.6 2.5 Preparation Example 2 201 92 87.2 91.0 3.2 2.0 Preparation Example 3 196 89 86.6 90.4 2.5 1.2 Preparation Example 4 197 90 83.4 86.4 3.5 2.4 Preparation Example 5 201 91 84.1 87.8 3.1 1.9 Preparation Example 6 203 93 85.8 89.3 2.4 1.1 Preparation Example 7 195 95 87.7 87.3 5.2 3.0 Preparation Example 8 197 92 84.3 88.6 3.7 2.5 Preparation Example 9 201 94 87.0 90.5 3.4 2.1 Preparation Example 10 200 93 82.6 85.8 5.3 3.2 Preparation Example 11 195 91 84.7 86.5 3.8 5.7 Preparation Example 12 189 88 86.2 88.3 3.5 2.3

division Surface resistance uniformity Haze Light reflectance (%) Preparation Example 1 1.29 12.12 6.57 Preparation Example 2 1.38 11.37 6.39 Preparation Example 3 1.48 11.54 6.68 Preparation Example 4 1.23 11.23 5.68 Preparation Example 5 1.05 10.98 5.79 Preparation Example 6 1.15 10.58 5.45 Preparation Example 7 1.58 11.74 6.89 Preparation Example 8 1.64 11.68 7.03 Preparation Example 9 1.73 11.35 7.15 Preparation Example 10 1.92 12.21 7.45 Preparation Example 11 1.88 11.89 7.54 Preparation Example 12 1.83 12.34 7.37

Through the above examples and manufacturing examples, it was confirmed that the transparent electrode film of the present invention has excellent optical characteristics and electrical characteristics, and when applied to the PDLC smart window has a characteristic effect that can exhibit the beam projection screen function.

Claims (14)

A multi-layered composite film in which a surface anti-reflection thin film layer, a light diffusion film layer, a surface modified polymer film layer, an optical layer, and an ITO thin film layer are sequentially stacked,
The surface anti-reflection thin film layer is a two- or three-layered sputtering deposition film, wherein the first thin film layer having a refractive index of 1.300 to 1.700 and the second thin film layer having a refractive index of 2.000 to 2.500 are sequentially stacked or
A first thin film layer having a refractive index of 1.300 to 1.700, a second thin film layer having a refractive index of 2.000 to 2.500, and a third thin film layer having a refractive index of 1.300 to 1.700 are sequentially stacked.
The surface-modified polymer film layer has a contact angle of 7.5 to 18.0 ° for pure water, and the surface of the surface-modified polymer film layer has an oxygen content of 20 to 24% by weight. The method of claim 1, wherein the first thin film layer and the third thin film layer comprises one or more selected from SiO ₂ and MgF ₂ ,
The second thin film layer is a transparent electrode film for a smart window comprising at least one selected from TiO ₂ , Nb ₂ O ₅ , ZrO ₂ and Y ₂ O ₃ . The transparent electrode film for a smart window according to claim 1, wherein the first thin film layer and the third thin film layer have an average thickness of 80 to 120 nm, and the second thin film layer has an average thickness of 10 to 30 nm. The method of claim 1, wherein the surface-modified polymer film layer is modified by plasma surface treatment of one or both surfaces of the polymer film,
The polymer film is polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), polycarbonate (PC), polypropylene (PP), polyvinyl chloride (PVC), polyethylene (PE), poly Methyl methacrylate (PMMA), a transparent electrode film for a smart window comprising at least one selected from polyamide and polyimide. delete According to claim 1, wherein the surface-modified polymer film layer has an arithmetic mean roughness (Ra) of 0.70 ~ 1.25nm, the root mean square roughness (Rq) of 0.90 ~ 1.55nm,
Smart window transparent electrode film, characterized in that the average thickness of 80 ~ 200㎛. The multilayer silicon of claim 1, wherein the optical layer is formed by sequentially stacking a first silicon oxide layer (SiO ₂ ), a second silicon oxide layer (SiO _x ), and a first silicon oxide layer (SiO ₂ ) from a surface-modified polymer film layer. An oxide film,
When the first silicon oxide film and the second silicon oxide film have an average thickness of 5 nm and the refractive index of the first silicon oxide film is 1.40 to 1.50, the refractive index of the second silicon oxide film is 0.02 to 0.20 larger than that of the first silicon oxide film. Transparent electrode film for smart window characterized in that. The transparent electrode film for a smart window according to claim 1, wherein the ITO thin film layer has an average thickness of 10 to 30 nm. The method of claim 1, wherein the ITO thin film layer
The initial vacuum ^{(1.0 ~ 4.0) × 10 -6} torr, the vacuum step ^{(5.0 ~ 9.0) × 10 -4} torr, tin under the conditions of the vapor deposition injection ratio 270 ~ 300sccm, and 4 ~ 8sccm of Ar and O ₂ mixture gas ratio (Sn) using a target material containing 6.0 to 8.5% by weight, a transparent electrode film for a smart window, characterized in that formed by depositing by RF magnetron sputtering method. The method of claim 1, wherein the transparent electrode film has a sheet resistance of 60 to 100 Ω / cm ² , sheet resistance uniformity of -5.00 to 5.00%, light transmittance of 90 to 95%, haze 8.0 to 18.0%, light reflectance of 5 to 9%. Transparent electrode film for smart windows. A PDLC smart window comprising the transparent electrode film of any one of claims 1 to 4 and 6 to 10. The method of claim 11, wherein the transparent electrode film; A liquid crystal layer formed on the ITO thin film layer of the transparent electrode film; An ITO thin film layer formed on the liquid crystal layer; PDLC smart window comprising a; polymer film layer formed on the ITO thin film layer. 12. A beam projection imaging screen comprising the PDLC smart window of claim 11. Plasma pretreatment of the surface of the polymer film to produce a surface-modified polymer film;
Performing a roll-to-roll sputtering of the surface-modified polymer film to deposit an optical layer including a multilayer silicon oxide film having a three-layer structure;
Roll-to-roll sputtering on the optical layer to deposit an ITO thin film layer to produce a first composite film in which the high-frequency film layer, the optical layer and the ITO thin film layer are sequentially stacked;
A fourth step of forming a second composite film in which an optical acid film layer, a high-frequency film layer, an optical layer, and an ITO thin film layer are sequentially formed by forming an optical acid film layer under the first composite film;
Roll-to-roll sputtering is formed on the light diffusion film layer of the second composite film to form a surface antireflection thin film layer having a two- or three-layer structure so that the surface antireflection thin film layer, the light diffusion film layer, the surface modified polymer film layer, the optical layer and A fifth step of manufacturing a third composite film in which the ITO thin film layers are sequentially stacked; And
Performing a process including; six steps of heat treating the third composite film.
The optical layer is formed by sequentially stacking a first silicon oxide film (SiO ₂ ), a second silicon oxide film (SiO _x ), and a first silicon oxide film (SiO ₂ ) from the surface of the polymer film layer.
The surface anti-reflection thin film layer may be formed by sequentially stacking a low refractive index first thin film layer and a high refractive index second thin film layer from a surface of a light diffusing film layer, or a low refractive index first thin film layer, a high refractive index second thin film layer, and a low refractive index. The third thin film layer is laminated in sequence,
The low refractive index is 1.300 ~ 1.700, the high refractive index is a method of manufacturing a transparent electrode film for a smart window, characterized in that 2.000 ~ 2.500.

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