JP4775728B2 - Production apparatus and production method for transparent conductive film - Google Patents

Description

  The present invention provides a continuous production apparatus for a transparent conductive film in which a first transparent layer (high refractive index layer), a second transparent layer (low refractive index layer), and a transparent conductive layer are laminated on a transparent plastic film. And a method for manufacturing a transparent conductive film suitable for a resistive touch panel or a capacitive touch panel with high productivity and stability.

  A transparent conductive film in which a transparent thin film with low resistance is laminated on a transparent plastic film is used for applications utilizing the conductivity, for example, flat panel displays such as liquid crystal displays and electroluminescence displays, and transparent transparent resistive touch panels Widely used in electrical and electronic fields such as electrodes.

  In recent years, touch panels are widely recognized as input interfaces, and in particular, portable terminals such as portable information terminals, digital video cameras, and digital cameras are increasingly equipped with touch panels on display displays in order to omit operation keys. On the other hand, high definition of display bodies such as liquid crystal displays used in these mobile terminals is further advanced, and the electrode film for touch panel incorporated in the front surface of such display bodies may not lower the visibility. It is strongly desired. That is, when used as an electrode film for a resistive touch panel, if the transmittance is low, the brightness of a display body such as a liquid crystal display is lowered and the display screen becomes dark, making it difficult to see the display. Moreover, when the electrode film is colored, the color display of a display color (particularly white) of a liquid crystal display or the like changes, and it becomes difficult to obtain a clear image. For this reason, the electrode film is desired to have high transmittance and little coloring.

  In recent years, an increasing number of cases where a capacitive touch panel is mounted on a mobile device such as a mobile phone or a portable music terminal. Such a capacitive touch panel has a configuration in which a dielectric layer is laminated on a patterned conductor, and is touched with a finger or the like to be grounded via the capacitance of the human body. At this time, a change occurs in the resistance value between the patterning electrode and the ground point, and the position input is recognized. However, when the conventional transparent conductive film is used, the difference in optical characteristics between the portion having the transparent conductive thin film layer and the removed portion is large, so that the patterning is emphasized, and the front surface of the display body such as a liquid crystal display is emphasized. There has been a problem that the visibility is lowered when arranged.

  In order to improve visibility in a transparent conductive film, it has been proposed to use layers of different refractive indexes used in antireflection processing and utilize light interference. Specifically, it has been proposed to use optical interference by providing layers having different refractive indexes between the transparent conductive layer and the base film (see Patent Documents 1 to 3). Although the transparent conductive film having this structure can improve the visibility, in these documents, it is described how to maintain good stability and productivity in a continuous sputtering apparatus such as a roll coater. This has not been studied at all.

  On the other hand, an apparatus described in Patent Document 4 has been proposed as a roll coater type continuous sputtering apparatus for a transparent conductive film. Although this sputtering apparatus is excellent in productivity and stability as a film forming apparatus having only a transparent conductive thin film layer, the apparatus described in this document uses the transparent conductive material for the above-mentioned resistive touch panel or capacitive touch panel. It was not always satisfactory to stably produce a film with high productivity.

Japanese Patent Laid-Open No. 11-286066 JP 2000-301648 A JP 2006-346878 A JP 2003-183813 A

  The present invention was devised in view of the above-mentioned problems of the prior art, and its purpose is to produce a transparent conductive film suitable for a resistive touch panel or a capacitive touch panel with high productivity and stability. An object of the present invention is to provide an apparatus and a method that can be manufactured.

  As a result of intensive studies to achieve the above object, the present inventors have fed back the optical characteristics of the transparent conductive film after film formation to control the plasma emission intensity or discharge voltage during sputtering, and are laminated by sputtering. By keeping the layer thickness substantially constant, it was found that even the transparent conductive film for the above-mentioned use can be stably produced with good productivity, and the present invention has been completed.

That is, the present invention has the following configurations (1) to (6).
(1) A continuous production apparatus for a transparent conductive film in which a first transparent layer, a second transparent layer having a lower refractive index than the first transparent layer, and a transparent conductive layer are laminated in this order on the transparent plastic film. A film unwinding chamber for unwinding the wound plastic film, a degassing chamber for removing residual solution and moisture in the unrolled plastic film, a first buffer chamber, A first film forming chamber for forming a first transparent layer and a second transparent layer by a sputtering method, and a second film forming chamber for forming a second transparent layer and a transparent conductive layer by a sputtering method And a second buffer chamber, and a film winding chamber for winding the plastic film formed in the first and second film forming chambers, and the manufacturing apparatus in which the plastic film passes through these chambers. Filmed A measuring device is provided for measuring the spectral transmittance or the spectral reflectance of the plastic film from the second buffer chamber until the film is wound in the film winding chamber. Plasma emission intensity or discharge during sputtering for forming the second transparent layer so that the difference between the transmittance or spectral reflectance value and the preset target spectral transmittance or spectral reflectance value is reduced. A manufacturing apparatus comprising a device for controlling voltage.
(2) The manufacturing apparatus according to (1), wherein the measuring device is provided in the second buffer chamber.
(3) A continuous manufacturing method of a transparent conductive film in which a first transparent layer, a second transparent layer having a lower refractive index than the first transparent layer, and a transparent conductive layer are laminated in this order on the transparent plastic film. The plastic film is a film unwinding chamber for unwinding the plastic film, a degassing chamber for removing residual solution and moisture in the unrolled plastic film, a first buffer chamber, and a first transparent film. A first film formation chamber for forming a layer and a second transparent layer by a sputtering method; a second film formation chamber for forming a second transparent layer and a transparent conductive layer by a sputtering method; In the manufacturing method of passing through the buffer chamber and the film winding chamber for winding the plastic film formed in the first and second film forming chambers, the film is transferred from the second buffer chamber to the film winding chamber. The spectral transmittance or spectral reflectance of the plastic film is measured until the film is wound, and the measured spectral transmittance or spectral reflectance value and a preset target spectral transmittance or spectral reflectance are measured. A manufacturing method comprising controlling plasma emission intensity or discharge voltage during sputtering for forming a second transparent layer so that a difference in reflectance value is reduced.
(4) The manufacturing method according to (3), wherein the measurement is performed in the second buffer chamber.
(5) The production method according to (3) or (4), wherein the measurement of the spectral transmittance or the spectral reflectance is performed at at least three places including the vicinity of the center and both ends in the width direction of the film.
(6) The production method according to any one of (3) to (5), wherein measurement and control are continuously performed.

  According to the manufacturing apparatus and the manufacturing method of the present invention, the optical characteristics of the formed film are measured, and the plasma emission intensity or the discharge voltage is controlled so as to reduce the deviation from the target optical characteristics. The thickness of the layer to be laminated is kept substantially constant, and a transparent conductive film suitable for a resistive touch panel or a capacitive touch panel can be provided with high productivity and stability.

It is explanatory drawing regarding the whole structure of the manufacturing apparatus of this invention. It is a measurement result of the spectral transmittance in Example 1 of the present invention. It is a measurement result of the spectral reflectance in Example 2 of this invention. It is a measurement result of the spectral transmittance in comparative example 1 of the present invention.

  The transparent conductive film of the present invention is obtained by laminating a first transparent layer, a second transparent layer having a lower refractive index than the first transparent layer, and a transparent conductive layer in this order on a transparent plastic film. Hereinafter, the constituent layers of the transparent conductive film of the present invention will be described.

  The transparent plastic film used as a substrate in the transparent conductive film of the present invention is formed by forming an organic polymer into a film by melt extrusion or solution extrusion, and if necessary, stretching in the longitudinal direction and / or the width direction. Heat-fixed and heat-relaxed. Examples of organic polymers include polyethylene, polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyimide, polyamideimide, polyethersulfane, polyetheretherketone, Examples include polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, polyphenylene sulfide, polyphenylene oxide, polystyrene, syndiotactic polystyrene, and norbornene-based polymer.

  Among these organic polymers, polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, syndiotactic polystyrene, norbornene-based polymer, polycarbonate, polyarylate and the like are preferable. These organic polymers may be copolymerized in a small amount with other organic polymer monomers, or may be blended with other organic polymers.

  The thickness of the transparent plastic film is preferably 10 to 300 μm, more preferably 70 to 260 μm. When the thickness of the plastic film is less than 10 μm, the mechanical strength is insufficient, and handling in the pattern forming process of the transparent conductive thin film may be difficult. On the other hand, if the thickness exceeds 300 μm, the thickness of the touch panel becomes too thick, which may make it unsuitable for mobile devices.

  The transparent plastic film may be subjected to a surface activation treatment such as a corona discharge treatment, a glow discharge treatment, a flame treatment, an ultraviolet irradiation treatment, an electron beam irradiation treatment, and an ozone treatment as long as the object of the present invention is not impaired.

  In addition, the transparent plastic film has a cured product layer mainly composed of a curable resin for the purpose of improving adhesion with the first transparent layer, imparting chemical resistance, and preventing precipitation of low molecular weight substances such as oligomers. It may be provided.

  The curable resin is not particularly limited as long as it is a resin that is cured by application of energy such as heating, ultraviolet irradiation, electron beam irradiation, etc., such as silicone resin, acrylic resin, methacrylic resin, epoxy resin, melamine resin, polyester resin, urethane resin, etc. Is mentioned. From the viewpoint of productivity, a curable resin containing an ultraviolet curable resin as a main component is preferable.

  As the ultraviolet curable resin, for example, it is synthesized from polyfunctional acrylate resin such as acrylic acid or methacrylic acid ester of polyhydric alcohol, diisocyanate, polyhydric alcohol and hydroxyalkyl ester of acrylic acid or methacrylic acid. And other multifunctional urethane acrylate resins. If necessary, a monofunctional monomer such as vinyl pyrrolidone, methyl methacrylate, or styrene can be added to these polyfunctional resins for copolymerization.

  Further, in order to improve the adhesion between the first transparent layer and the cured product layer, it is effective to further treat the cured product layer. Specific methods include a method of increasing carbonyl groups, carboxyl groups, and hydroxyl groups by a discharge treatment that irradiates glow discharge or corona discharge, or a chemical treatment by treatment with an acid or alkali to produce amino groups, hydroxyl groups, carbonyl groups. And a method for increasing the polar group.

  The ultraviolet curable resin is usually used by adding a photopolymerization initiator. As the photopolymerization initiator, known compounds that absorb ultraviolet rays and generate radicals can be used. For example, various benzoins, phenyl ketones, benzophenones, and the like can be used. It is preferable that the addition amount of a photoinitiator shall be 1-5 mass parts with respect to 100 mass parts of ultraviolet curable resins.

  The density | concentration of the resin component in the coating liquid for hardened | cured material layers can be appropriately selected in consideration of the viscosity etc. according to the coating method. For example, the proportion of the total amount of the ultraviolet curable resin and the photopolymerization initiator in the coating solution is usually 20 to 80% by mass. Moreover, you may add other well-known additives, for example, leveling agents, such as a silicone type surfactant and a fluorine type surfactant, to this coating liquid as needed.

  The method for coating the prepared coating solution on the transparent plastic film is not particularly limited, and a known method such as a bar coating method, a gravure coating method, or a reverse coating method can be used.

  Moreover, it is preferable that the thickness of a hardened | cured material layer is the range of 0.1-15 micrometers, More preferably, it is 0.5-10 micrometers, Most preferably, it is 1-8 micrometers. When the thickness of the cured product layer is less than 0.1 μm, it is difficult to form a sufficiently cross-linked structure, so that chemical resistance is likely to be lowered, and adhesion due to a low molecular weight such as an oligomer is likely to be lowered. . On the other hand, when the thickness of the cured product layer exceeds 15 μm, the productivity tends to decrease.

The first transparent layer used in the transparent conductive film of the present invention has a higher refractive index than the second transparent layer. The refractive index of the first transparent layer is in the range of 1.70 to 2.50, preferably 1.90 to 2.30. By forming the first transparent layer having a high refractive index and the second transparent layer having a low refractive index, which will be described later, on the transparent plastic film, a light interference effect can be obtained. As the first transparent layer, for example, TiO ₂ , Nb ₂ O ₅ , or In ₂ O ₃ is used. However, TiO ₂ layer by sputtering, the case of forming the _Nb 2 _{O 5} layer, there is a possibility that the deposition rate is slow and productivity is lowered. For this reason, an In ₂ O ₃ layer is preferable as the first transparent layer from the viewpoint of productivity.

In the case of forming the first transparent layer, Ti, Nb, In, ITM (In the alloy of Sn) metal target and _{TiO 2-X} such _{as, Nb 2 O 5-X,} In 2 O 3-X, ITO An oxide target such as (Sn-doped In ₂ O ₃ ) can be used. When the oxide target is used, the film thickness of the first transparent layer can be stabilized.

The second transparent layer used in the transparent conductive film of the present invention is formed on the first transparent layer, and its refractive index is preferably 1.30 to 1.60. When the refractive index of the second transparent layer is less than 1.30, it becomes a porous film, so that the electrical characteristics of the transparent conductive thin film layer formed thereon are deteriorated. On the other hand, when the refractive index exceeds 1.60, light interference with the transparent conductive thin film layer becomes too weak, making it difficult to obtain a desired transparent conductive film. As the second transparent layer, for example complex metal oxides such as _SiO 2, _Al 2 transparent metal oxide such as _{O 3} and _SiO 2 _-Al 2 _{O 3} is used.

In the case of forming the second transparent layer, a metal target such as Si or Al, an alloy target thereof, a target capable of DC sputtering including SiC, or the like can be used. For this reason, when forming a low refractive index layer such as SiO ₂ , a reactive sputtering method in which oxygen gas is introduced is used.

  The transparent conductive layer used in the transparent conductive film of the present invention is formed on the second transparent layer, and its refractive index is preferably 1.80 to 2.20. When the refractive index of the transparent conductive layer is less than 1.80, it is difficult to form a transparent conductive thin film layer with good conductivity. On the other hand, when the refractive index exceeds 2.20, reflection at the interface between air and the transparent conductive thin film layer becomes large, and it becomes difficult to satisfy desired optical characteristics.

  As the transparent conductive layer, for example, indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, indium-zinc composite oxide, or the like may be used. it can. Among these, indium-tin composite oxide is preferable from the viewpoint of environmental stability and circuit processability.

  Next, an example of the transparent conductive film production apparatus of the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of the manufacturing apparatus of the present invention.

  As shown in FIG. 1, the manufacturing apparatus of the present invention includes a film unwinding chamber 1, a degassing chamber 2, a first buffer chamber 3, a first film forming chamber 4, and a second buffer chamber 5. And a second film forming chamber 4 ′ and a film winding chamber 6.

  The film unwinding chamber 1 is a chamber for setting a wound transparent plastic film roll and unwinding it. The degassing chamber 2 is a chamber for evaporating and removing the residual solution and moisture contained in the transparent plastic film. The degassing chamber 2 allows the film quality of the film due to the influence of the residual solution and moisture at the time of film formation. The decrease can be suppressed.

  The first buffer chamber 3 is a chamber for preventing the residual solution and moisture evaporated in the degassing chamber 2 from entering the first film formation chamber 4. In the apparatus of FIG. 1, the first buffer chamber 3 has a plastic film between the degassing chamber 2 and the first film forming chamber 4 and between the first film forming chamber 4 and the second buffer chamber 5. It plays the role of a buffer room to keep the degree of vacuum when moving.

  The first film formation chamber 4 is a chamber for forming a first transparent layer (high refractive index layer) and a second transparent layer (low refractive index layer) on a plastic film by a sputtering method. The film forming chamber 4 'is a room for forming a second transparent layer (low refractive index layer) and a transparent conductive layer on the plastic film layer laminated in the first film forming chamber 4 by sputtering. is there.

  The second buffer chamber 5 is a chamber for suppressing a decrease in the degree of vacuum in the second film formation chamber 4 ′ when the film roll is replaced in the film winding chamber 6. In the apparatus of FIG. 1, the second buffer chamber 5 is located between the second film forming chamber 4 ′ and the film winding chamber 6, and between the first buffer chamber 3 and the second film forming chamber 4 ′. It plays the role of a buffer room to keep the degree of vacuum when the plastic film moves.

  The film winding chamber 6 is a chamber for winding the plastic film formed in the first film forming chamber 4 and the second film forming chamber 4 ′. The film-formed transparent conductive film wound from the film winding chamber 6 is taken out.

  The manufacturing apparatus of the present invention is provided with a measuring device for measuring the spectral transmittance or the spectral reflectance of the plastic film formed in the first film forming chamber 4 and the second film forming chamber 4 ′. In order to form the second transparent layer so that the difference between the spectral transmittance or spectral reflectance value measured by this measuring apparatus and the target spectral transmittance or spectral reflectance value set in advance becomes small. The greatest feature is that a device for controlling the plasma emission intensity or the discharge voltage during sputtering is provided. Conventionally, it has been considered that if the sputtering apparatus is set so that the plasma emission intensity or the discharge voltage during sputtering is constant, the film thickness formed will be constant. It has been found that even if the intensity and discharge voltage are constant, the formed film thickness slightly changes when the target is scraped due to aging or the surroundings of the sputtering source become dirty. The device of the present invention feeds back the plasma emission intensity or discharge voltage during sputtering as an index of the change in film thickness by using the change in spectral transmittance or reflectance of the formed plastic film as an indicator of the change in film thickness. Effective change is effectively prevented.

  The apparatus for measuring spectral transmittance or spectral reflectance is such that after a plastic film is formed in the first film forming chamber 4 and the second film forming chamber 4 ′, the film take-up chamber 6 is moved from the second buffer chamber 5. It is provided until it is wound up by. The measuring device is preferably between the time when the film is taken up in the film take-up chamber 6 after leaving the second film-formation chamber 4 ′ in order to accurately measure in a place with a high degree of vacuum immediately after film formation. Provided in the second buffer chamber 5.

  The spectral transmittance or the spectral reflectance of the plastic film can be appropriately measured by a conventionally known method. For example, the light from the light source is guided into the second buffer chamber 5 by an optical fiber and applied to the plastic film. Alternatively, the reflected light is again guided out of the second buffer chamber 5 by the optical fiber, dispersed by the filter of the spectroscopic unit, converted into an electric signal by the photometer of the light receiving unit, and the measured value is calculated by the arithmetic processing unit of the computer. , By outputting the result. The output is input to the control device, and the control device controls the plasma emission intensity or the discharge voltage during sputtering for forming the second transparent layer based on this output value. Of the three layers (first transparent layer, second transparent layer, and transparent conductive layer) formed by sputtering, the plasma emission intensity or discharge voltage during sputtering is controlled only for the second transparent layer. This is because the thickness of the second transparent layer is most easily adjusted in terms of its material. The control can be appropriately performed by a conventionally known method. For example, impedance control for controlling a sputtering voltage constant by controlling a flow rate of a reactive gas introduced into the apparatus during sputtering, or an element or reaction to be sputtered. It can be performed by plasma emission control for controlling the emission intensity derived from the property gas to be constant. Light projection or light reception for measurement is preferably performed as close to the film as possible from the viewpoint of improving measurement accuracy, and measurement should be performed at least at three locations including the vicinity of the center and both ends in the width direction of the film. Is preferred.

  The light source for measurement needs to irradiate the plastic film with light having a wavelength of 300 to 800 nm, but it may be either continuous projection or intermittent projection. May be. The spectroscopic unit may be set to a specific wavelength by a filter, but it can measure at a plurality of wavelengths in order to eliminate the influence of fluctuations in the light amount of the light source, etc., and improve the measurement accuracy. As the light receiving portion, a photomultiplier tube, a silicon diode, or the like having good light receiving sensitivity can be used. The arithmetic processing unit includes a light receiving element that converts light that has been transmitted or reflected through the film into an electrical signal corresponding to the intensity, an amplification circuit that amplifies the obtained electrical signal to a level that can be calculated, and background noise. A noise film circuit to be removed, an arithmetic circuit for obtaining a film thickness by calculation, and a display circuit for monitoring the result, the calculation may be analog calculation or digital calculation. When using a commercially available member, for example, PHOTAL (registered trademark) -MCPD-1000 manufactured by Otsuka Electronics Co., Ltd. can be used. When using this apparatus, it is preferable to first measure the transmittance of the film before film formation, adjust the zero point, measure the transmittance after film formation, and calculate the actual transmittance.

  In the control device, the spectral transmittance or spectral reflectance value measured by the measuring device is compared with a preset target spectral transmittance or spectral reflectance value, and the difference between the measured value and the target value is small. It is controlled to become. Specifically, when the measured value is lower than the target value, the plasma emission intensity or discharge voltage during sputtering for forming the second transparent layer is increased, and when the measured value is higher than the target value, the plasma emission intensity or Control the discharge voltage low. When the plasma emission intensity or the discharge voltage is increased, the thickness of the second transparent layer is increased, and when it is decreased, the thickness of the second transparent layer is decreased. Such measurement and control are preferably performed continuously. As a result, a transparent conductive film with little variation in spectral transmittance or spectral reflectance, i.e., little variation in film thickness of the formed layer can be obtained continuously and stably.

  Next, the manufacturing method of the transparent conductive film of this invention is demonstrated based on the manufacturing apparatus of FIG. First, the plastic film 16 set on the unwinding roll 7 starts from the film unwinding chamber 1 and sequentially passes through the degassing chamber 2 and the first buffer chamber 3 to reach the first film forming chamber 4. In the degassing chamber 2, the plastic film 16 is heated by the heater 14 to evaporate residual solution and moisture in the film, and the evaporated component is adsorbed by the cryocoil 11. After sequentially laminating the first transparent layer and the second transparent layer on the plastic film 16 in the first film formation chamber 4, the second buffer chamber passes through the first buffer chamber 3 again, It reaches the film forming chamber 4 '. Then, after the second transparent layer and the transparent conductive layer are sequentially laminated on the plastic film 16 in the second film formation chamber 4 ′, the film is again transferred to the film winding chamber 6 via the second buffer chamber 5. It reaches.

  The first buffer chamber 3 and the first film forming chamber 4, and the second film forming chamber 4 ′ and the second buffer chamber 5 are separated by the cooling roll 9 or 10 and the partition 12, and the film passes therethrough. Only the gap is open. In the first and second film forming chambers 4 and 4 ′, the cathode boxes 13 to which the targets are attached are arranged on the side surfaces in the radial direction of the first cooling roll 9 and the second cooling roll 20, respectively. For example, when a high voltage is applied to the target in an argon gas atmosphere (which may include a reactive gas such as oxygen gas), a part of the target material is sputtered onto the plastic film, and the first transparent layer and the second transparent layer In addition, a transparent conductive layer is continuously formed.

  A device 15 for sandwiching the film is preferably provided between the film unwinding chamber 1 and the degassing chamber 2 and between the film winding chamber 6 and the second buffer chamber 5. Thus, when the film roll is replaced, only the film unwinding chamber 1 and the film winding chamber 6 are opened to the atmosphere, and the roll can be replaced while the vacuum degree of the first and second film forming chambers is maintained at 10 Pa or less. Is possible.

  In addition, when a film with a large curl is used, the film may be rubbed and scratched when passing through the device 15 for sandwiching the film. For this reason, it is preferable to provide a curl suppression assist mechanism across the front and rear of the device 15 for sandwiching the film. For example, as an auxiliary mechanism, an auxiliary roll 17 can be used, whereby the film can be prevented from being damaged by pulling the film in the width direction or pressing the curl of the film.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples. The performance of the transparent conductive film was measured by the following method.

(1) Total light transmittance Based on JIS-K7136, the total light transmittance was measured using Nippon Denshoku Industries Co., Ltd. product and NDH-1001DP.

(2) Surface resistance value Based on JIS-K7194, the surface resistance value was measured by the 4-terminal method. As a measuring instrument, Lotest AMCP-T400 manufactured by Mitsubishi Oil Chemical Co., Ltd. was used.

(3) Color b value Based on JIS-K7105, the color b value was measured with standard light C / 2 using a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., ZE-2000).

(4) Pen sliding durability A load of 5N was applied to a polyacetal pen (tip shape: 0.8 mmR), and a linear sliding test was performed 300,000 times (reciprocating 50,000 times) on the transparent conductive film. . The sliding distance at this time was 30 mm, and the sliding speed was 60 mm / second. After this sliding durability test, whether the sliding portion was whitened was visually observed and evaluated according to the following criteria.
○: The sliding part is not whitened. Δ: The sliding part is slightly whitened. X: The sliding part is whitened.

(5) Visibility After printing an etching resist on the transparent conductive film, the transparent conductive layer was removed by immersion in 1N hydrochloric acid to form a 1 cm × 3 cm pattern. A biaxially oriented polyethylene terephthalate film having an acrylic adhesive layer with a refractive index of 1.52 on the transparent conductive layer side was bonded as a protective film. Using FMV-BIBLOLOOX T70M / T manufactured by Fujitsu Ltd., the screen was displayed in white, a film with a protective film attached was placed in front of it, and the appearance of patterning was observed from various angles, and evaluated according to the following criteria: .
○: Patterning is hardly visible.
Δ: Patterning is slightly visible.
X: Patterning is visible.

(6) Spectral transmittance Using a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation), light is irradiated to the transparent conductive thin film side in the range of 380 to 780 nm, and indoor air is used as a reference for transmittance. It was measured.

(7) Spectral reflectance A black glossy tape (manufactured by Nitto Denko Corporation, vinyl tape No21; black) was bonded to the opposite surface of the transparent conductive film to the transparent conductive thin film layer to prepare a measurement sample. Using a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation), the light is irradiated on the transparent conductive thin film side in the range of 380 to 780 nm, and the relative specular reflectance with respect to the Al deposition mirror is measured at an incident angle of 5 °. did.

Example 1
A mixed solvent of toluene / MEK (80/20: mass ratio) as a solvent was added to 100 parts by mass of a photopolymerization initiator-containing ultraviolet curable acrylic resin (manufactured by Dainichi Seika Kogyo Co., Ltd., Seika Beam EXF-01J). Was added so as to be 50% by mass, and stirred to dissolve uniformly to prepare a coating solution.

The prepared coating solution was applied to a biaxially oriented transparent polyethylene terephthalate film (A4300, width: 1300 m, thickness: 188 μm, manufactured by Toyobo Co., Ltd.) having an easy-adhesion layer on both sides so that the thickness of the coating film becomes 5 μm. Applied. After drying at 80 ° C., the coating film was cured by irradiating with ultraviolet rays (light quantity: 300 mJ / cm ² ) using an ultraviolet irradiation device (UB042-5AM-W type, manufactured by Eye Graphics Co., Ltd.). Subsequently, the coating film was similarly provided also about the opposite surface.

What wound the said film was installed in the manufacturing apparatus of FIG. 1, and the transparent conductive film was manufactured. The first two targets in the first film forming chamber were indium-tin composite oxide (indium oxide / tin oxide = 64 wt% / 36 wt%, manufactured by Sumitomo Metal Mining Co., Ltd.), and DC magnetron sputtering method. Then, sputtering was performed at an input power of 1.0 W / cm ² at an oxygen partial pressure of 3.0 × 10 ⁻² Pa and a total pressure of 0.6 Pa. The temperature of the first cooling roll at this time was 0 ° C., and the line speed was 1.3 m / min (first transparent layer).
The following four targets in the first film formation chamber and the subsequent four targets in the second film formation chamber use B-doped columnar silicon (manufactured by ULVAC Material Co., Ltd.), and the total pressure is 0 by DC magnetron sputtering. Sputtering was performed at a power of 3.0 W / cm ² at a pressure of .6 Pa. At this time, the temperature of the second cooling roll is also 0 ° C., and the cathode flow rate of each cathode forming the second transparent layer is controlled using Genfloa's Speedflo so that the discharge voltage during sputtering is constant. (Second transparent layer).
The last two targets in the second film forming chamber were indium-tin composite oxide (indium oxide / tin oxide = 95 wt% / 5 wt%, manufactured by Sumitomo Metal Mining Co., Ltd.), and DC magnetron sputtering method. Then, sputtering was performed with a partial pressure of oxygen of 1.0 × 10 ⁻² Pa and a total pressure of 0.6 Pa with an input power of 3.0 W / cm ² (transparent conductive layer).

  When film formation is continuously performed on a 1000 m film roll, the film after film formation in the second film formation chamber using Otsuka Electronics PHOTO-MCPD-1000 installed in the second buffer chamber is used. Spectral transmittance was measured continuously. At this time, the setting value of the discharge voltage at the time of sputtering of each cathode forming the second transparent layer is changed so that the spectrum of the spectral transmittance is constant (the maximum peak is 500 nm), and the film of the second transparent layer The thickness was controlled. Specifically, when the spectral transmittance is shifted to the lower wavelength side than the desired spectral transmittance, the discharge voltage during sputtering is increased, and conversely, when the spectral transmittance is shifted to the higher wavelength side, the discharge during sputtering is increased. The voltage was lowered.

  The obtained roll of the transparent conductive film was sampled every 100 m, and the surface resistance value and optical characteristics (total light transmittance, color b) at three points in the width direction (positions at the center and both ends of the 500 mm from the center to the left and right). Value, spectral transmittance), pen sliding durability, and visibility were evaluated. The total light transmittance, the color b value, and the spectral transmittance are indicators of transparency, and the pen sliding durability is an indicator of durability when a transparent conductive film is used for a touch panel. Is an index of performance when a transparent conductive film is used for a capacitive touch panel. At that time, the surface resistance value is the average value of the whole, the optical characteristics are the maximum value and the minimum value, the pen sliding durability and the patterning visibility are shown in Table 1 and FIG.

(Example 2)
A transparent conductive film was produced using the same film and production apparatus as in Example 1. The first two targets in the first film forming chamber were indium-tin composite oxide (indium oxide / tin oxide = 64 wt% / 36 wt%, manufactured by Sumitomo Metal Mining Co., Ltd.), and DC magnetron sputtering method. Then, sputtering was performed with an oxygen partial pressure of 3.0 × 10 ⁻² Pa and a total pressure of 0.6 Pa with an input power of 0.35 W / cm ² . The temperature of the first cooling roll at this time was 0 ° C., and the line speed was 2.0 m / min (first transparent layer).
The following four targets in the first film formation chamber and the subsequent four targets in the second film formation chamber use B-doped columnar silicon (manufactured by ULVAC Material Co., Ltd.), and the total pressure is 0 by DC magnetron sputtering. Sputtering was performed at a power of 3.0 W / cm ² at a pressure of .6 Pa. At this time, the temperature of the second cooling roll was also 0 ° C., and each cathode forming the second transparent layer was subjected to sputtering using Genfloa's Speedflo. Plasma emission intensity during sputtering (filtered to measure 288 nm intensity) ) Was performed while controlling the oxygen flow rate so as to be constant (second transparent layer).
The last two targets in the second film forming chamber were indium-tin composite oxide (indium oxide / tin oxide = 95 wt% / 5 wt%, manufactured by Sumitomo Metal Mining Co., Ltd.), and DC magnetron sputtering method. Then, sputtering was performed at a partial pressure of oxygen of 1.0 × 10 ⁻² Pa and a total pressure of 0.6 Pa with an input power of 0.7 W / cm ² (transparent conductive layer).

  When film formation is continuously performed on a 1000 m film roll, the film after film formation in the second film formation chamber using Otsuka Electronics PHOTO-MCPD-3700 installed in the second buffer chamber is used. Spectral reflectance was measured continuously. At this time, the setting value of the plasma emission intensity of each cathode forming the low refractive index layer was changed so that the spectral reflectance was constant, and the film thickness of the low refractive index layer was controlled. Specifically, when the spectral reflectance is shifted to the lower wavelength side than the desired spectral reflectance, the plasma emission intensity is increased. Conversely, when the spectral reflectance is shifted to the higher wavelength side, the plasma emission intensity is decreased. . The obtained transparent conductive film was evaluated for surface resistance, optical properties (total light transmittance, color b value, spectral reflectance), pen sliding durability, and visibility in the same manner as in Example 1. At that time, the surface resistance value is the average value of the whole, the optical characteristics are the maximum value and the minimum value, the pen sliding durability and the patterning visibility are shown in Table 1 and FIG.

(Comparative Example 1)
A transparent conductive film was produced in the same manner as in Example 1 except that the film thickness of the second transparent layer was not controlled by measuring the spectral transmittance of the film and changing the setting value of the sputtering voltage. The obtained transparent conductive film was evaluated for surface resistance, optical properties (total light transmittance, color b value, spectral transmittance), pen sliding durability, and visibility in the same manner as in Example 1. At that time, the surface resistance value is the average value of the whole, the optical characteristics are the maximum value and the minimum value, the pen sliding durability and the patterning visibility are shown in Table 1 and FIG.

Table 1 shows the evaluation results of the transparent conductive films obtained in Examples 1 and 2 and Comparative Example 1.

  From the results shown in Table 1, the transparent conductive film rolls produced by the methods of Examples 1 and 2 had small variations in optical characteristics and excellent productivity. On the other hand, the transparent conductive film roll produced by the method of the comparative example which does not have feedback control of optical characteristics has poor productivity and significant variations in optical characteristics.

  According to the present invention, the optical characteristics of the deposited film are measured and controlled by the plasma emission intensity or the discharge voltage so as to reduce the deviation from the target optical characteristics. The transparent conductive film suitable for a resistive touch panel or a capacitive touch panel can be provided with high productivity and stability.

1: Film unwinding chamber 2: Degassing chamber 3: First buffer chamber 4: First film forming chamber 4 ′: Second film forming chamber 5: Second buffer chamber 6: Film winding chamber 7: Unwinding roll 8: Winding roll 9: First cooling roll 10: Vacuum exhaust device 11: Cryo coil 12: Partition 13: Cathode box 14: Heater 15: Device for sandwiching film 16: Plastic film 17: Auxiliary roll 18: PC
19: Plasma monitor 20: Second cooling roll

Claims (6)

  An apparatus for continuously producing a transparent conductive film in which a first transparent layer, a second transparent layer having a lower refractive index than the first transparent layer, and a transparent conductive layer are laminated in this order on a transparent plastic film. A film unwinding chamber for unwinding the wound plastic film, a degassing chamber for removing residual solution and moisture in the unrolled plastic film, a first buffer chamber, and a first transparent A first film formation chamber for forming a layer and a second transparent layer by a sputtering method; a second film formation chamber for forming a second transparent layer and a transparent conductive layer by a sputtering method; In the manufacturing apparatus in which the plastic film passes through the two buffer chambers and the film winding chamber for winding the plastic film formed in the first and second film forming chambers. Plastic A measuring device is provided for measuring the spectral transmittance or the spectral reflectance of the tic film from the second buffer chamber until the film is wound in the film winding chamber. Plasma emission intensity or discharge during sputtering for forming the second transparent layer so that the difference between the transmittance or spectral reflectance value and the preset target spectral transmittance or spectral reflectance value is reduced. A manufacturing apparatus comprising a device for controlling voltage.   The manufacturing apparatus according to claim 1, wherein the measuring device is provided in the second buffer chamber.   A continuous manufacturing method of a transparent conductive film in which a first transparent layer, a second transparent layer having a lower refractive index than the first transparent layer, and a transparent conductive layer are laminated in this order on a transparent plastic film, A plastic film is a film unwinding chamber for unwinding the plastic film, a degassing chamber for removing residual solution and moisture in the unrolled plastic film, a first buffer chamber, a first transparent layer and a first transparent layer A first film formation chamber for forming two transparent layers by a sputtering method, a second film formation chamber for forming a second transparent layer and a transparent conductive layer by a sputtering method, a second buffer chamber, And in the manufacturing method of passing the film winding chamber for winding the plastic film formed in the first and second film forming chambers, the film is transferred from the second buffer chamber to the film winding chamber. The spectral transmittance or spectral reflectance of the plastic film is measured until it is scraped, and the measured spectral transmittance or spectral reflectance value and a preset target spectral transmittance or spectral reflectance are measured. A method for controlling the plasma emission intensity or discharge voltage during sputtering for forming the second transparent layer so as to reduce the difference between the values.   The manufacturing method according to claim 3, wherein the measurement is performed in the second buffer chamber.   5. The method according to claim 3, wherein the measurement of the spectral transmittance or the spectral reflectance is performed in at least three places including the vicinity of the center in the width direction of the film and the vicinity of both ends.   Measurement and control are performed continuously, The manufacturing method in any one of Claims 3-5 characterized by the above-mentioned.

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