JP2015132780A - Coating liquid feed system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating liquid feed system capable of continuously and stably supplying, to a coating device, coating liquid of a physical property varying with a lapse of time or the like in a state appropriate for uniform coating.SOLUTION: The coating liquid feed system includes: a preparation oven 101 that is used for preparing coating liquid containing a polymer and includes a decompression device; a storage oven 104 for sequentially receiving, from the preparation oven, the coating liquid prepared by the preparation oven, and storing the coating liquid; a circulation passage R1 for sequentially receiving, from the storage oven, the coating liquid stored in the storage oven and guiding it to the storage oven again; and a dispersion device 106 that is disposed in a midway of the circulation passage and disperses the coating liquid flowing through the circulation passage.

Description

  The present invention relates to a coating liquid feeding system.

  Optical films that transmit or reflect and absorb light and have various effects are known. This optical film can exhibit optical functions such as refraction, birefringence, antireflection, wide viewing angle, light diffusion, and brightness improvement.

  As such an optical film, an infrared shielding film, an antireflection film, an orientation film, a polarizing film, a polarizing plate protective film, a retardation film, a viewing angle widening film, a brightness enhancement film, an electromagnetic wave shielding film, etc. ) And flat panel displays (FPD) such as plasma displays (PDP), and window glass of buildings and vehicles.

  In recent years, an optical functional layer that provides an optical function to an optical film has been required to have a nano-order thinning. By reducing the thickness of the optical functional layer, various effects can be obtained, for example, if the refractive index layer of the infrared shielding film, the infrared light shielding performance is improved. Furthermore, the optical functional layer is required to have a high level of film thickness uniformity. By making the film thickness uniform, a high-quality optical film without color unevenness can be provided.

  As a method for forming a thin optical functional layer, a technique is known in which a coating liquid containing a polymer (hereinafter referred to as a coating liquid) is applied to a transparent substrate and dried (for example, Patent Document 1). reference).

JP 2008-183882 A

  However, physical properties such as viscosity may change with the passage of time, and in this case, in the above-described conventional technology, there is a problem that it is difficult to apply continuously and stably to a substrate. is there. Even if the properties are suitable for uniform application when the coating solution is prepared, the coating solution can be properly applied to the substrate if it changes to an inappropriate property before it is applied to the substrate. Therefore, a defect occurs in the optical film. For example, if the viscosity of the coating solution becomes excessively large, the coating solution does not flow smoothly on the substrate, or foreign matter due to coagulation occurs in the coating solution. In this case, the coating solution cannot be continuously and uniformly applied stably, and as a result, the productivity of a high-quality optical film cannot be improved, resulting in a problem.

  The present invention has been made in view of the above-described problems, and is capable of continuously and stably supplying a coating solution whose physical properties change over time in a state suitable for uniform coating to a coating apparatus. A liquid delivery system is provided.

  The above object can be achieved by providing any of the following inventions.

  (1) A preparation kettle equipped with a pressure reducing device for preparing a coating solution containing a polymer, and the coating solution prepared in the preparation kettle are sequentially discharged from the preparation kettle and the coating solution is stored. A storage tank, a circulation path that sequentially flows the coating liquid stored in the storage tank out of the storage tank, and again leads to the storage tank; and the coating that is provided in the middle of the circulation path and passes through the circulation path And a dispersion device for dispersing the liquid.

  (2) The coating liquid feeding system according to (1), wherein the degree of pressure reduction by the pressure reducing device is 1.3332 to 66.660 kPa (10 to 500 Torr).

  (3) The preparation kettle further includes a stirring device for stirring the coating solution, and a stirring peripheral speed of the stirring device is 0.2 to 2 m / sec. (1) or (2) Coating liquid delivery system.

  (4) The coating liquid feeding system according to any one of (1) to (3), wherein the dissolved oxygen amount of the coating liquid flowing out of the preparation kettle is 1 to 5 mg / L.

  (5) The apparatus further includes a measuring device that measures the physical properties of the coating liquid, and the dispersing device varies the dispersion strength based on the measured value measured by the measuring device. The coating liquid feeding system according to any one of the above.

  (6) The measuring device measures physical properties related to viscosity, and the dispersing device increases the dispersion strength when the measured value is larger than a predetermined upper limit value, and the measured value is smaller than the predetermined lower limit value. In the case, the coating liquid feeding system according to (5), in which the dispersion strength is reduced.

  (7) The coating liquid feeding system according to any one of (1) to (6), further including a filtering device that is provided in the middle of the circulation path and filters the coating liquid.

  (8) It further has a coating device that applies the coating liquid to a substrate, and a supply path that is connected to the storage tank or the circulation path and sequentially guides the coating liquid to the coating apparatus. (7) The coating liquid feeding system according to any one of the above.

  (9) The amount of the coating liquid flowing in the system exceeds the storage amount of the storage tank, so that the coating liquid guided through the supply path is supplied to the coating device without interruption, and the coating liquid The coating liquid feeding system according to (8), wherein the coating liquid is continuously coated on the substrate.

  (10) The coating liquid feeding system according to (9), wherein the coating liquid prepared in the preparation kettle is fed to the storage kettle before all the coating liquid stored in the storage kettle flows out. .

  (11) The coating liquid feeding system according to any one of (7) to (10), wherein the measuring device is provided on at least one place on the circulation path, the supply path, and the storage hook. .

  (12) The apparatus further includes a drying device for drying the coating film applied on the substrate, and a plurality of layers are formed on the substrate by repeating the application and drying of the coating solution onto the substrate a plurality of times. The coating liquid feeding system according to any one of (7) to (11), in which a laminated body in which the coating film is formed is prepared.

  (13) The laminate is formed by alternately laminating a high refractive index layer and a low refractive index layer having different refractive indexes, and at least one of the high refractive index layer and the low refractive index layer is formed. The coating liquid feeding system according to (12), which is an infrared shielding film containing metal oxide particles and a water-soluble resin.

  (14) A step of applying a coating solution produced using the coating solution feeding system according to any one of (1) to (13) on a substrate, and drying the coating solution on the substrate. And a process for producing an optical film.

  According to the coating liquid feeding system of the present invention, the coating liquid is continuously dispersed while circulating the coating liquid containing a polymer (also referred to as “coating liquid” in the present specification). Therefore, even a coating liquid whose physical properties such as viscosity change with the passage of time can be continuously and stably supplied to a coating apparatus in a state suitable for uniform coating.

  Further, the coating liquid feeding system of the present invention has a preparation kettle equipped with a decompression device for preparing the coating liquid, and is included in the coating liquid by performing a decompression treatment using the decompression device. Bubbles can be removed or reduced. By doing so, a coating failure can be suppressed, and a high-quality coating film can be provided in a short time and productivity can be improved as compared with a case where no decompression treatment is performed.

It is a schematic block diagram of the optical film manufacturing system which concerns on 1st Embodiment. It is a schematic diagram of the milder which is one form of a dispersing device. It is a schematic diagram of the pressure type homogenizer which is one form of a dispersing device. It is a schematic block diagram of the optical film manufacturing system which concerns on 2nd Embodiment. It is a schematic block diagram of the optical film manufacturing system which concerns on 3rd Embodiment.

  Embodiments of the present invention will be described below. In addition, this invention is not limited only to the following embodiment. In the present specification, “X to Y” indicating a range means “X or more and Y or less”, and “weight” and “mass”, “wt%” and “mass%”, “part by weight” and “ “Part by mass” is treated as a synonym. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%. Moreover, the ratio of drawing may be exaggerated for description.

  The present invention provides a preparation kettle equipped with a decompression device for preparing a coating liquid containing a polymer, and the coating liquid prepared in the preparation kettle sequentially flows out of the preparation kettle and stores the coating liquid. A storage tank, a circulation path for sequentially flowing out the coating liquid stored in the storage tank from the storage tank, and again leading to the storage tank; and provided in the middle of the circulation path, and passing through the circulation path And a dispersion device that disperses the coating liquid.

  Thus, the present invention relates to a coating liquid feeding system. According to a preferred embodiment of the present invention, the coating liquid feeding system of the present invention is applied to a part of an optical film manufacturing system. Therefore, hereinafter, a coating liquid feeding system which is an embodiment of the present invention will be described while explaining the overall optical film manufacturing system.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an optical film manufacturing system according to the first embodiment.

  The optical film manufacturing system 10 is configured by connecting a plurality of devices, and manufactures an optical film through a plurality of steps realized by each device. In the example shown in FIG. 1, the optical film manufacturing system 10 roughly divides and performs a preparation process, a circulation process, a supply process, and a coating process.

  The structure and operation of the device included in each process will be described.

(Preparation process)
The optical film manufacturing system 10 prepares a coating liquid for forming an optical functional layer of the optical film in the preparation step. The preparation process includes a coating liquid preparation pot 101 (also simply referred to as “preparation pot 101” in the present specification), a liquid feeding apparatus 102, and a filtration apparatus 103.

  The preparation pot 101 is a container for preparing a coating solution. The preparation kettle 101 of the present invention includes a decompression device. By performing the decompression process using the decompression device, it is possible to remove or reduce bubbles contained in the coating liquid, and in a short period of time, high quality compared to those that do not perform the decompression process while suppressing application failures. A coating film can be provided.

  The method for preparing the coating solution is not particularly limited, and is, for example, a method in which a polymer and, if necessary, additives such as a crosslinking agent and metal oxide particles are added to a solvent and mixed by stirring. At this time, the order of addition of the respective components is not particularly limited, and the respective components may be sequentially added and mixed while stirring, or may be added and mixed at one time while stirring. The method for preparing these coating solutions is appropriately determined for each coating solution.

  The capacity of the preparation kettle 101 is preferably about 100 to 5000 L, more preferably about 500 to 3000 L.

  Further, the inner diameter φ of the preparation pot 101 is preferably about 0.5 to 2 m, more preferably about 0.9 to 1.7 m.

  The coating liquid prepared in the preparation kettle 101 is decompressed by a decompression device provided in the preparation kettle 101. The degree of decompression by the decompression device is preferably 1.3332 to 66.660 kPa (10 to 500 Torr) in that a high-quality coating film can be provided. More preferably, it is 50-400 Torr, More preferably, it is 80-300 Torr. The time for the decompression treatment by the decompression device is preferably about 20 to 200 minutes, more preferably about 30 to 150 minutes. Moreover, there is no restriction | limiting in particular in the method of pressure reduction processing, However, Preferably it carries out using a vacuum pump. There are no particular restrictions on the type of vacuum pump. Moreover, it is preferable to provide a trap between the preparation kettle 101 and the vacuum pump so that the sucked bubbles do not flow into the vacuum pump.

  It is preferable that the preparation kettle 101 further includes a stirring device. And the stirring peripheral speed of a stirring apparatus is preferable in it being 0.2-2 m / sec, when using a pitched paddle blade. More preferably, it is 0.3-1.5 m / sec, More preferably, it is 0.4-1.0 m / sec. If it is less than 0.2 m / sec, the stirring is weak, and it may take a long time to reduce the amount of dissolved oxygen. On the other hand, if it exceeds 2 m / sec, bubbles may be involved and the bubbles may not be efficiently removed.

  In addition, as a size (blade diameter (phi)) / hook inner diameter (phi) of a pitched paddle blade, 0.3-0.7 are preferable and 0.4-0.6 are more preferable from a viewpoint of stirring efficiency.

  The preparation tank 101 is connected to a coating liquid storage tank 104 (also simply referred to as “storage tank 104” in this specification) in order to supply the coating liquid to a storage tank included in the circulation process.

  The liquid feeding device 102 is provided in a path through which the coating liquid flows out from the preparation pot 101. The liquid feeding device 102 is, for example, a pump, and can control the outflow of the prepared coating liquid and stop of the outflow. The liquid delivery device 102 can appropriately set the flow rate and speed of the coating liquid when the coating liquid is allowed to flow out.

  The filtration device 103 is provided in a path through which the coating liquid flows out from the preparation pot 101. The filtration device 103 removes foreign matters mixed in the coating liquid, and foreign matters due to bubbles or aggregation generated in the coating liquid. The coating liquid from which the foreign matter has been removed is sent to a circulation process.

  Although there is no restriction | limiting in particular as the filtration apparatus 103, For example, the cylindrical filter made from Loki Techno Co., Ltd. can be used suitably. The type of filter is not particularly limited and may be appropriately selected depending on the type of coating solution. However, a depth type or a pleated type is preferable in order to efficiently capture foreign matter in the coating solution with a low pressure loss. The filtration flow rate is not particularly limited, but is preferably 5 to 40 L / min. Moreover, since the passage of foreign substances can be suppressed as the filtration pressure is smaller, it is usually preferable to use at 0.2 MPa or less. In the actual treatment, it is desirable to immerse the filter medium in the same liquid as the coating liquid in advance and remove the air inside the filter medium. Further, this filtration treatment has an advantage that impurities and insoluble matters contained in the coating liquid can be removed at the same time as the removal of bubbles. In the present invention, the coating liquid may be supplied to the storage tank 104 without passing through the filtration device 103.

(Circulation process)
The optical film manufacturing system 10 circulates the prepared coating liquid while maintaining appropriate physical properties in a circulation process (coating liquid circulation system). In this embodiment, the circulation step includes a storage tank 104, a liquid feeding device 105, a dispersion device 106, a defoaming device 107, a filtration device 108, and a circulation path R1.

  The storage pot 104 stores the coating liquid so that the coating liquid can be continuously supplied. Thereby, the physical property of the coating liquid in the storage pot 104 can be made uniform. The storage tank 104 is connected to a circulation path R <b> 1 for allowing the coating liquid to flow out of the storage tank 104 and returning the discharged coating liquid to the storage tank 104 again. The storage tank 104 is also connected to a supply path L1 for sending the coating liquid to the supply process and the application process.

  The liquid feeding device 105 is provided on the circulation path R1. The liquid feeding device 105 is a pump, for example, and can control the outflow of the coating liquid stored in the storage pot 104 and the stoppage of the outflow. The liquid feeding device 105 can appropriately set the flow rate and speed of the coating liquid when the coating liquid is allowed to flow out.

  The dispersion device 106 is provided on the circulation path R1. The dispersion device 106 performs a dispersion process or a shearing process on the coating liquid. As a result, in the coating solution, the bonds (van der Waals bonds, etc.) between the molecules of the polymer and the terminal groups in the molecule are broken, so that the entanglement between the molecules is eliminated, and as a result, the viscosity is reduced.

  The configuration of the dispersing device 106 is not particularly limited as long as the coating liquid can be dispersed and sheared, and may be a commercially available milder, a pressure type homogenizer, a high-speed rotary shearing type homogenizer, or the like. In the case of a milder, for example, the dispersing device 106 causes the coating liquid to flow between the fixed tooth and the movable tooth, and performs a dispersion process or a shearing process on the coating liquid by a shearing force generated by a velocity gradient between the fixed tooth and the movable tooth.

  FIG. 2 is a schematic diagram of a milder that is one form of a dispersing device. The milder shown in FIG. 2 has a stator tooth 1 that is a fixed tooth and a rotor tooth 2 that is a rotating tooth. The coating liquid 4 moving in the gap (shear gap) La between the stator teeth 1 and the rotor teeth 2 generates a velocity gradient (shear velocity) in the radial direction of the rotor teeth 2. Due to the velocity gradient, an internal frictional force (shearing force) is generated between the stator teeth 1 and the rotor teeth 2. Since the bubbles contained in the coating liquid 4 pass through the shear gap La while receiving a shearing force, they are divided and the gas-liquid interface increases.

  Here, in this specification, the “shear rate” is calculated by the following formula (1).

  The “minimum gap” refers to the minimum gap to which a shearing force is applied in the flow path through which the coating precursor solution moves. The “speed” refers to the moving speed of the coating precursor solution when the coating precursor solution passes through the minimum gap. At this time, when the coating precursor solution is moved at a constant speed, the highest shearing force is applied when passing through the minimum gap.

  In FIG. 2, the shear gap La corresponds to the “minimum gap” in the equation (1), and the speed of the coating liquid 4 when moving through the shear gap La, which is the minimum gap, corresponds to the “speed” in the equation (1). . Since the introduction of the coating liquid 5 into the shear gap is performed in the radial direction from the slit gap of the rotor tooth 2, the coating liquid 4 flowing into the shear gap La and the introduced coating liquid 5 collide continuously. Will be repeated. That is, according to the milder of FIG. 2, the coating solution is continuously sheared and mixed.

  In the milder, the minimum gap between the stator teeth and the rotor teeth in the shear gap is preferably 0.05 to 0.8 mm, and more preferably 0.1 to 0.6 mm. Moreover, as a rotational speed of a rotor tooth | gear, it is preferable that it is 500-50,000 rpm, and it is more preferable that it is 1,000-20,000 rpm. The shear rate can be adjusted by appropriately setting the minimum gap between the stator teeth and the rotor teeth in the shear gap and the rotational speed of the rotor teeth. With such a rotational speed, the area in which the bubbles contained in the coating solution come into contact with the coating solution is increased. Moreover, although there is no restriction | limiting in particular also in a shear rate, Preferably it is 1000 (1 / sec) or more, More preferably, it is 5000-10000000 (1 / sec), More preferably, it is 10000-1600000 (1 / sec).

  As such a milder, for example, Ebara Milder (manufactured by Ebara Manufacturing Co., Ltd.), Milder (manufactured by Taihei Kiko Co., Ltd.), or the like can be used.

  FIG. 3 is a schematic diagram of a pressure homogenizer that is one form of a dispersing device. The pressure type homogenizer in FIG. 3 has a valve seat 11 and a valve 12. The coating liquid 14 supplied by a pressurizing mechanism (not shown) moves between the valve seats 11 at high pressure and at high speed. When the coating liquid passes through the narrow gap Lb between the valve seat 11 and the valve 12, the liquid between the coating liquid that has collided with the valve 12 and changed the flow direction and the coating liquid that is about to pass through the gap Lb. It is considered that friction between the two occurs, and as a result, a large shearing force is generated in the coating solution. This shear force is proportional to the minimum gap Lb. In FIG. 3, the gap Lb is the minimum gap to which a shearing force is applied, and corresponds to the “minimum gap” in Equation (1). Further, the speed of the coating liquid 14 when moving through the gap Lb, which is the minimum gap, corresponds to the “speed” in Expression (1). In the pressure type homogenizer, the distance between the valve seat and the valve is preferably 0.05 to 0.5 mm, and more preferably 0.1 to 0.3 mm. Moreover, as a speed | rate at the time of passing between a valve seat and a valve | bulb, it is preferable that it is 1-500 m / s, and it is more preferable that it is 3-300 m / s. The shear rate can be adjusted by appropriately setting the distance between the valve seat and the valve, the supply condition of the coating liquid in the pressurizing mechanism, and the like. Although there is no restriction | limiting in particular also in the pressure at the time of supply of a coating liquid, For example, about 400-600 bar is preferable.

  As the pressure homogenizer as described above, for example, a pressure homogenizer LAB1000 (manufactured by SMT Co., Ltd.) or the like can be used.

  The high-speed rotary shearing homogenizer is a processing device that has a configuration similar to that of a milder and performs a shearing process between a rotor that rotates at high speed and a stator that is adjacent via a narrow gap. The coating liquid flows by the rotor rotating at high speed, and the bubbles contained in the coating liquid 4 are divided by the shear generated by the velocity gradient generated between the stator and the collision between the coating liquids, and the gas liquid The interface increases.

  As a high-speed rotational shear type homogenizer, for example, T.M. K. ROBOMIX (manufactured by PRIMIX Co., Ltd.), CLEARMIX CLM-0.8S (manufactured by M Technique Co., Ltd.), homogenizer (manufactured by Microtech Nichion Co., Ltd.) and the like can be used.

  If it is determined that the amount of bubbles contained in the coating liquid is large, a defoaming process may be performed. The defoaming device 107 removes bubbles contained in the coating liquid and dissolved air dissolved in the coating liquid. As a principle of defoaming, for example, a method of separating bubbles and liquid by centrifugal force and discharging the bubbles by evacuation or a method using ultrasonic waves can be considered. However, as long as defoaming can be performed, the defoaming device 107 may be a device using any other principle.

  The filtering device 108 removes foreign matters mixed in the coating liquid, and foreign matters due to bubbles or aggregation generated in the coating liquid. The coating liquid from which the foreign matter has been removed returns to the storage pot 104 through the circulation path R1. As the filtering device 108, the one described above can be used.

  As described above, in the circulation step, the coating liquid flows out from the storage tank 104 to the circulation path R1, is subjected to processing by the dispersing device 106, the defoaming device 107, and the filtration device 108, and then returns to the storage tank 104. The coating liquid returned to the storage pot 104 moves while being dispersed in the storage pot 104, and then flows out to the circulation path R1 again, and the above processing is repeated.

  The processing strength of the dispersion device 106, the defoaming device 107, and the filtration device 108 in the circulation process was such that the physical properties of the coating liquid were kept within an appropriate range depending on conditions such as the use of the optical film and the properties of the coating liquid used. Can be set as appropriate. When the filtering device 108 is provided on the circulation path, it is possible to remove foreign matters mixed in the coating liquid, bubbles generated in the coating liquid, and foreign matters due to aggregation.

  In the circulation process, for example, if the viscosity of the coating solution is larger than the appropriate range, the coating solution does not flow smoothly on the substrate when applied to the substrate, and it is difficult to uniformly apply the coating solution. There is a possibility. Furthermore, it is conceivable that the coating is applied in the presence of foreign matter due to aggregation of the coating solution. Conversely, if the viscosity of the coating solution is smaller than the proper range, the applied coating solution will not be stable, and the coating solution will flow due to the air flow during transportation or the wind pressure during drying, etc. And unevenness (in the present specification, this is also referred to as “application failure”). Moreover, when it coats and overlaps with another coating liquid, it may mix with another coating liquid and may cause the cloudiness of an optical film.

  On the other hand, in the present invention, since the above processing is repeatedly performed in the circulation path R1, the dispersion treatment, the defoaming treatment, the filtration treatment and the like are continuously performed at an appropriate strength while circulating the prepared coating liquid. By applying to, physical properties such as the viscosity of the coating solution can be kept within a range suitable for coating.

  Here, the viscosity of the coating solution is preferably 100 to 1000 mPa · s, more preferably 120 to 700 mPa · s, and even more preferably 150 to 650 mPa · s, just before coating by a coating apparatus described later. It is. With such a viscosity, bubbles and the like in the coating solution can be efficiently removed, and as a result, a high-quality coating film can be provided. In addition, when it exceeds 1000 mPa · s, the viscosity is too high, and even if the decompression process is performed, the removal of bubbles may be insufficient and a coating failure may occur.

  Moreover, the dissolved oxygen amount of the coating solution that has flowed out of the preparation kettle is preferably 1 to 5 mg / L, and more preferably 1.5 to 4 mg / L. When the amount of dissolved oxygen exceeds 5 mg / L, there is little dissolution of bubbles in the coating film, and the removal of bubbles by the decompression process becomes insufficient, and application failure may not be prevented. On the other hand, if it is less than 1 mg / L, the time required for the decompression treatment may become long and continuous coating may not be possible.

  In the circulation process, the number of times the coating liquid is circulated is not predetermined, and a predetermined flow rate of the coating liquid is circulated from the storage tank 104 according to a setting of the liquid feeding device 105 or the like. It is sequentially sent to the route R1 and circulated. Since the circulated coating liquid returns to the storage tank 104 and is stirred, the physical properties of the entire coating liquid contained in the storage tank 104 can always be kept in a state suitable for coating.

  A part of the coating liquid stored in the storage tank 104 is sent to the supply process through the supply path L <b> 1 connected to the storage tank 104.

  In addition, the apparatus is located in order of the dispersion | distribution apparatus 106, the defoaming apparatus 107, and the filtration apparatus 108 on circulation path | route R1. However, the order of these devices can be changed as appropriate. In addition, one device that integrates the functions of a plurality of the above devices may be provided for the circulation process. For example, a dispersion defoaming device in which the functions of the dispersion device 106 and the defoaming device 107 are integrated may be provided for the circulation process.

  Further, in the circulation step, a device other than the above may be provided, or any of the above devices may not be provided. In particular, in the present invention, the preparation kettle 101 is equipped with a decompression device that performs a decompression process. Therefore, even if the defoaming device 107 is omitted, a high-quality coating film can be provided and the device can be omitted. Productivity is also improved from a viewpoint.

(Supply process)
In the supplying process, the optical film manufacturing system 10 supplies the prepared and circulated coating liquid to the coating process. The supply process includes a liquid feeding device 109, a flow meter 110, a dispersion device 111, a defoaming device 112, a filtration device 113, and a supply path L1. The supply path L1 is a path for supplying the coating liquid from the storage pot 104 in the circulation process to the coating process. The liquid feeding device 109, the flow meter 110, the dispersion device 111, the defoaming device 112, and the filtration device 113 are provided in the supply path L1.

  The liquid feeding device 109 sends the coating liquid that has flowed out of the storage tank 104 in the circulation process to each device provided in the supply path L1. For the liquid delivery device 109, the above description is valid as well.

  The flow meter 110 is a device that measures the flow rate of the coating liquid passing through the supply path L1. The flow rate of the liquid feeding device 109 may be appropriately controlled according to the flow rate of the coating liquid measured by the flow meter 110. As the flow meter 110, for example, a flap type, a hot wire type, a Karman vortex type, or a negative pressure sensing type flow meter is used. In addition to the flow meter or instead of the flow meter, a pressure gauge that measures the pressure of the coating liquid in the supply path L1 may be provided.

  The dispersing device 111, the defoaming device 112, and the filtering device 113 can be the same as those described above. The coating liquid from which foreign matters have been removed through these operations is applied to the coating process through the supply path L1. Sent.

  In addition, the apparatus is located in order of the flowmeter 110, the dispersion | distribution apparatus 111, the defoaming apparatus 112, and the filtration apparatus 113 on the supply path | route L1. However, the order of these devices can be changed as appropriate. Moreover, one apparatus which integrated the function of the said several apparatus may be provided for a supply process. For example, a dispersion defoaming device in which the functions of the dispersion device 111 and the defoaming device 112 are integrated may be provided in the supply process. Further, in the supply process, a device other than the above may be provided, or any of the above devices may not be provided.

(Coating process)
In the coating process, the optical film manufacturing system 10 applies a coating solution to a substrate to produce a polymer film (coating film). The coating process includes a coating device 114, a setting device 115, and a drying device 116.

  The coating device 114 applies a coating solution to the substrate. The coating device 114 may apply the coating solution to the base material in a single layer or may be applied in a plurality of layers. In the case where a plurality of coating liquids are applied to a base material in multiple layers (so-called multilayer coating), at least the adjacent coating liquids are prepared with different distributions and materials. Therefore, in FIG. 1, one preparation pot 101 is shown, but actually, a plurality of preparation pots are prepared, and a plurality of types of coating liquids are supplied to the coating apparatus 114 through separate preparation steps and supply steps. Also good.

  The set device 115 once cools the polymer film formed on the substrate. Since the polymer film immediately after coating has a low viscosity, if hot air is applied and dried immediately after coating, the film thickness may partially change due to the hot air, and a uniform refractive index may not be obtained over the entire surface. In addition, when multi-layer coating is performed, the components move between the layers, and the boundary between the layers can be vague enough to adversely affect the desired optical performance. However, once the obtained polymer film is cooled, the film thickness does not change even when hot air is applied, and it is possible to prevent the boundary between layers from becoming ambiguous enough to adversely affect the desired optical performance. Of course, in the optical film manufacturing system 10, the setting device 115 may be omitted.

  For example, the drying device 116 applies hot air to the polymer film on the base material to dry the polymer film to further stabilize it, thereby completing the optical film.

  As described above, according to the optical film manufacturing system 10, the coating liquid is circulated and the dispersion treatment is continuously applied. Therefore, the coating liquid whose physical properties change with the passage of time or the like can be continuously and stably supplied in a state suitable for uniform coating.

  The optical film manufacturing system 10 also has a coating device 114 that applies the coating liquid to the substrate, and a supply path L1 that supplies the coating liquid to the coating device 114. Therefore, the coating liquid in a state suitable for uniform coating can be supplied to the coating apparatus, and the optical film can be efficiently manufactured.

  Further, the supply path L1 and the circulation path R1 are provided in parallel. Therefore, it is possible to maintain physical properties suitable for coating by circulating the coating liquid to the circulation path R1 while continuously supplying the coating liquid without stopping supply.

  In addition, the optical film manufacturing system 10 has a filtration device 108 in the middle of the circulation path R1. Accordingly, foreign matters mixed in the coating liquid, bubbles generated in the coating liquid and foreign matters due to aggregation can be removed, and the coating liquid can be continuously and stably supplied in a state suitable for uniform application.

  In the present invention, the preparation kettle 101 is provided with a decompression device that performs a decompression process. Therefore, by performing a decompression process using the decompression device, bubbles contained in the coating liquid can be removed or reduced, and a high-quality coating film can be provided in a short time while suppressing a coating failure. . Of course, even if the device is not equipped with a decompression device, the bubbles are removed to some extent by using the mass difference between the bubbles and the coating solution by leaving the coating solution in the preparation vessel 101 for a predetermined time. It is possible. However, in the method of removing bubbles due to such a mass difference, it takes a long time for the bubbles to float, particularly when the viscosity of the coating liquid increases. And if the time to stand still becomes long, all the coating liquids stored in the storage pot 104 will flow out and go to coating, and it will not be possible to apply continuously. On the other hand, in a situation where the application must be completed within a predetermined time, the time that can be allowed to stand still is limited, and as a result, the application turns in a state where a lot of bubbles are contained, and the application failure cannot be prevented. .

  On the other hand, in the present invention, the preparation pot 101 is provided with a pressure reducing device for performing a pressure reduction process, and therefore, a coating liquid higher than the coating liquid that can be stored in the storage pot 104 can be supplied to the coating apparatus 114. Is possible. That is, by making the amount of the coating liquid flowing through the optical film manufacturing system 10 exceed the storage amount of the storage tank 104, the coating liquid guided to the coating device 114 through the supply path L1 is supplied without interruption. In this way, air bubbles contained in the coating solution can be removed or reduced, coating failures can be suppressed, and high-quality coating films can be obtained in a short time. Can be provided. In addition, as a method for supplying the coating liquid guided through the supply path L1 without interruption and continuously coating the coating liquid on the base material, the preparation liquid is prepared before all the coating liquid stored in the storage tank 104 flows out. It is preferable to feed the coating solution prepared in the pot 101 to the storage pot 104. By doing so, the coating liquid can be prepared in the preparation tank 101 in parallel with the application of the coating liquid on the substrate, and the coating operation can be continuously performed without depleting the coating liquid in the storage tank 104. Can do.

  In addition, in this embodiment, although the circulation process demonstrated as what is provided after a preparation process, it is not limited to this. The circulation step may be located at any part between the time when the coating liquid is prepared and the time when it is applied. Moreover, in this embodiment, although the one circulation process was demonstrated as what is provided in the optical film manufacturing system 10, it is not limited to this. A plurality of circulation steps may be provided in the optical film manufacturing system 10.

(Second Embodiment)
Next, the optical film manufacturing system of 2nd Embodiment is demonstrated.

  In the first embodiment, the circulation path R1 and the supply path L1 are connected as separate paths to the storage tank 104 in the circulation process, and a liquid feeding device, a dispersion device, and the like are provided in each path. However, the circulation route R1 and the supply route L1 may share a part of the route and the apparatus, and the equipment in one route may be omitted. In the second embodiment, a case where the supply path L1 is connected in the middle of the circulation path R1 and a part of the path and the apparatus on the supply path L1 is omitted will be described.

  FIG. 4 is a schematic configuration diagram of an optical film manufacturing system according to the second embodiment. In FIG. 4, the same reference numerals are given to the same components as those in the first embodiment. The description of the same configuration as that of the first embodiment will be omitted, and a configuration different from that of the first embodiment will be described.

  As shown in FIG. 4, the preparation process and the coating process of the optical film manufacturing system 20 are the same as those in the first embodiment, and the circulation process and the supply process are different from those in the first embodiment.

  The optical film manufacturing system 20 has a coating device 114 that applies a coating liquid to a substrate, and is connected to the storage tank 101 or the circulation path R1 to supply a coating path L1 that sequentially guides the coating liquid to the coating device 114. It has further.

(Circulation process)
The circulation process of the optical film manufacturing system 20 is different from the first embodiment in that the supply path L1 is connected to the filtration device 108.

  In the circulation step, the coating liquid flows out from the storage tank 104 to the circulation path R1, and is sent to the filtration device 108 via the dispersion device 106 and the defoaming device 107. After the foreign substance is removed by the filtering device 108, the coating liquid returns to the storage pot 104 again through the circulation path R1. Here, a part of the coating liquid that passes through the filtration device 108 is sent to the supply process through the supply path L <b> 1 connected to the filtration device 108.

(Supply process)
The supply process of the optical film manufacturing system 20 includes a flow meter 110 and a supply path L1. The supply path L1 is connected to the filtration device 108 in the circulation process. Therefore, unlike the first embodiment, the liquid feeding device, the dispersing device, the defoaming device, and the filtering device on the supply path L1 are omitted.

  The coating liquid guided from the circulation process to the supply path L1 passes through the flow meter 110 and is sent to the coating apparatus in the coating process.

  In addition to the effect which the optical film manufacturing system 10 of 1st Embodiment achieves, the optical film manufacturing system 20 of 2nd Embodiment has the following effects.

  According to the optical film manufacturing system 20, the supply path L1 is connected to the circulation path R1, and equipment such as the supply path L1 and equipment can be omitted, so a compact optical film manufacturing system can be constructed while suppressing capital investment. it can.

  In the present embodiment, the supply path L1 is described as being connected to the filtration device 108, but the present invention is not limited to this. The supply path L1 may be connected to another device provided in the circulation path R1. Alternatively, a device for branching the route may be provided on the circulation route R1, and the supply route L1 may be connected to the device.

  Moreover, although this embodiment demonstrated that only the flow meter 110 was provided on the supply path | route L1, it is not limited to this. Devices other than the flow meter 110 may be provided on the supply path L1.

(Third embodiment)
Next, an optical film manufacturing system according to the third embodiment will be described.

  In addition to the configuration of the first embodiment, the third embodiment includes a measurement device that measures the physical properties of the coating liquid and a device that controls the dispersion device according to the measurement result of the measurement device in the circulation step. This is different from the first embodiment.

  FIG. 3 is a schematic configuration diagram of an optical film manufacturing system according to the third embodiment. In FIG. 3, the same reference numerals are given to the same components as those in the first embodiment. The description of the same configuration as that of the first embodiment will be omitted, and a configuration different from that of the first embodiment will be described.

  As shown in FIG. 3, the preparation process, the supply process, and the coating process of the optical film manufacturing system 30 are the same as those in the first embodiment, and only the circulation process is different from that in the first embodiment.

(Circulation process)
The circulation process of the optical film manufacturing system 30 further includes a measurement device 117 and a control device 118 in addition to the same configuration as in the first embodiment.

  The measuring device 117 is provided on the circulation path R1 and measures the physical properties of the coating liquid passing through the circulation path R1. The measuring device 117 is, for example, a viscometer that measures the viscosity of the coating liquid. As the viscometer, a viscometer of any method such as a rotary type, a vibration type, or a thin tube type may be used. The measuring device 117 notifies the control device 118 of information indicating the measurement result.

  Thus, it is preferable that the measuring device 117 is provided on at least one place on the circulation path R1, the supply path L1, and the storage tank 104.

  The control device 118 includes a CPU that operates according to a program, a memory that records various data and programs, a hard disk, and the like. The control device 118 controls the distribution device 106 based on information indicating the measurement result notified from the measurement device 117.

  For example, when the measuring device 117 is a viscometer, the control device 118 controls the dispersing device 106 based on the viscosity of the coating liquid measured by the measuring device 117. When the viscosity of the coating liquid is larger than a predetermined appropriate range, the control device 118 controls to increase the dispersion strength of the dispersion device 106. When the dispersing device 106 is a milder, the control device 118 controls the dispersing device 106 so as to increase the rotational speed of the movable teeth. Alternatively, when the viscosity of the coating liquid is smaller than a predetermined appropriate range, the control device 118 performs control so that the dispersion strength of the dispersion device 106 is lowered.

  In addition to the effect which the optical film manufacturing system 10 of 1st Embodiment achieves, the optical film manufacturing system 30 of 3rd Embodiment has the following effects.

  According to the optical film manufacturing system 30, the dispersion strength of the dispersion device 106 is controlled based on the physical properties of the coating liquid measured by the measurement device 117. Therefore, the circulating coating liquid can be more reliably maintained with physical properties suitable for uniform coating.

  Further, the optical film manufacturing system 30 measures the viscosity of the coating liquid with the measuring device 117, and increases the dispersion strength when the viscosity is larger than a predetermined proper range, and when the viscosity is smaller than the predetermined proper range. Controls the dispersing device 106 to reduce the dispersion strength. Therefore, the viscosity of the circulating coating liquid can be maintained in an appropriate range, and can be supplied in a state suitable for uniform coating.

  In the third embodiment, the example in which the measuring device 117 measures the viscosity of the coating liquid has been described. However, the present invention is not limited to this. The measuring device 117 may measure any physical property of the coating liquid, such as the kinematic viscosity, density, viscoelasticity, and temperature of the coating liquid.

  In the third embodiment, the example in which the control device 118 controls the dispersion device 106 based on the viscosity of the coating liquid has been described. However, the present invention is not limited to this. The control device 118 may control not only the dispersion device 106 but also the defoaming device 107 and the filtration device 108 based on various physical properties measured by the measurement device 117. For example, the control device 118 may control the defoaming device 107 and the filtering device 108 based on the density of the coating liquid. Specifically, when the density is smaller than a predetermined range, it may be determined that the ratio of bubbles or dissolved air in the coating liquid is large, and the defoaming strength of the defoaming device 107 may be controlled to be increased. . Alternatively, when the density is larger than the predetermined range, it is determined that foreign matter or the like due to coagulation has occurred in the coating liquid, and control is performed to perform maintenance of the filtration filter so as to increase the filtration strength of the filtration device 108. May be.

  In the third embodiment, the measurement device 117 is described as being provided in the circulation process, but the present invention is not limited to this. The measuring device 117 may be provided not only in the circulation path R1 but also in any place where the coating liquid passes, such as in the supply path L1 and the storage tank 104. A plurality of measurement devices 117 may be provided, and a plurality of devices may be controlled based on a plurality of measurement results. Thereby, a coating liquid can be supplied in the state more suitable for application | coating.

  As above, in the first to third embodiments, the variations of the optical film manufacturing system have been described. However, the above embodiment is merely an example, and various modifications can be made. For example, you may arrange | position a dispersion | distribution apparatus in the position different from the said Embodiment 1-3. In addition, the apparatuses may be arranged in a different order instead of the illustrated order to execute the processing.

(Materials, etc.)
Next, in 1st Embodiment-3rd Embodiment, the optical film manufactured, the material used for manufacture of an optical film, the manufacturing process of an optical film, etc. are demonstrated in detail.

<Optical film>
The optical film manufactured by the manufacturing method according to this embodiment is formed by forming at least one optical functional layer having a film thickness of 1 to 1000 nm on a substrate.

  The optical film has different functions depending on the composition and configuration of the optical functional layer. Therefore, the technical idea according to the present invention is various optical films, for example, an infrared shielding film, an antireflection film, an alignment film, a polarizing film, a polarizing plate protective film, a retardation film, by appropriately considering known matters. It can be used for a film, a viewing angle widening film, a brightness enhancement film, an electromagnetic wave shielding film, and the like.

  In the following description, an infrared shielding film in which refractive index layers (polymer films) having different refractive indexes are laminated will be described, but the present invention is not limited thereto. The infrared shielding film corresponds to an optical film, and the refractive index layer corresponds to an optical functional layer.

  In general, in an infrared shielding film, it is preferable to design a large difference in refractive index between adjacent refractive index layers from the viewpoint that the infrared reflectance can be increased with a small number of layers. In this embodiment, at least one of the refractive index differences between adjacent refractive index layers is preferably 0.1 or more, more preferably 0.3 or more, and particularly preferably 0.4 or more. Moreover, it is preferable that all the refractive index differences between the laminated refractive index layers are within the preferable range. However, even in this case, the outermost layer and the lowermost layer among the refractive index layers constituting the reflective layer may have a configuration outside the above preferred range.

  The reflectance in the specific wavelength region is determined by the difference in refractive index between two adjacent layers and the number of stacked layers, and the larger the difference in refractive index, the same reflectance can be obtained with a smaller number of layers. The refractive index difference and the required number of layers can be calculated using commercially available optical design software. For example, in order to obtain an infrared reflectance of 90% or more, if the refractive index difference is smaller than 0.1, it is necessary to stack 100 layers or more. In such a case, the productivity may decrease, the scattering at the laminated interface increases, the transparency may decrease, and the coating failure may occur during manufacturing.

  Furthermore, as an optical characteristic of the infrared shielding film of this embodiment, the transmittance in the visible light region shown in JIS R3106-1998 is 50% or more, preferably 75% or more, more preferably 85% or more. In addition, it is preferable that the region having a wavelength of 900 nm to 1400 nm has a region where the reflectance exceeds 50%.

  The infrared shielding film has a configuration in which a refractive index layer is laminated, so that at least one infrared light is irradiated when infrared light is irradiated from the base material side or from the laminated refractive index layer side. The part can be shielded to exhibit an infrared shielding effect.

  In one embodiment, the stacked refractive index layers are formed by alternately stacking high refractive index layers and low refractive index layers. The laminated high refractive index layer and low refractive index layer may be the same or different. Whether the refractive index layer is a high refractive index layer or a low refractive index layer is determined by comparing the refractive index with the adjacent refractive index layer. Specifically, when a refractive index layer is used as a reference layer, if the refractive index layer adjacent to the reference layer has a lower refractive index than the reference layer, the reference layer is a high refractive index layer (the adjacent layer is a low refractive index layer). It is judged to be a rate layer. On the other hand, if the refractive index of the adjacent layer is higher than that of the reference layer, it is determined that the reference layer is a low refractive index layer (the adjacent layer is a high refractive index layer).

  As described above, whether the layer is a high refractive index layer or a low refractive index layer is a relative one determined by the relationship with the adjacent refractive index layer, but the refractive index (nH) of the high refractive index layer is 1. It is preferably .60 to 2.50, more preferably 1.70 to 2.50, further preferably 1.80 to 2.20, and 1.90 to 2.20. Is particularly preferred. On the other hand, the refractive index (nL) of the low refractive index layer is preferably 1.10 to 1.60, more preferably 1.30 to 1.55, and 1.30 to 1.50. More preferably. In addition, the value measured as follows shall be employ | adopted for the value of the refractive index of each refractive index layer. Specifically, a sample is prepared by cutting a coating film obtained by applying a refractive index layer to be measured as a single layer on a support to a size of 10 cm × 10 cm. In order to prevent reflection of light on the back surface of the sample, a surface (back surface) opposite to the measurement surface is roughened, and light absorption processing is performed with a black spray. Using the spectrophotometer U-4000 type (manufactured by Hitachi, Ltd.), 25 samples of the reflectance in the visible region (400 nm to 700 nm) were measured using the spectrophotometer U-4000 type (manufactured by Hitachi, Ltd.). An average value is obtained, and an average refractive index is obtained from the measurement result.

  The range of the total number of refractive index layers is preferably 200 layers or less, more preferably 100 layers or less, and even more preferably 50 layers or less from the viewpoint of productivity.

  The thickness per layer of the refractive index layer is 1-1000 nm, preferably 20-800 nm, more preferably 50-350 nm.

<Coating liquid containing polymer (coating liquid)>
In the production of an infrared shielding film, usually, at least two kinds of coating liquids, ie, a coating liquid for a high refractive index layer and a coating liquid for a low refractive index layer are prepared as the coating liquid.

[Composition of coating solution]
The coating solution contains a polymer. Furthermore, a solvent, a crosslinking agent, metal oxide particles, an emulsion resin, and other additives may be included as necessary.

(High molecular)
The polymer that can be used is not particularly limited, and examples thereof include water-soluble polymers. The water-soluble polymer is not particularly limited, and examples thereof include a polymer having a reactive functional group, modified polyvinyl alcohol, gelatin, and thickening polysaccharide. In this specification, “water-soluble polymer” means a G2 glass filter (maximum) when dissolved in water so that the concentration of 0.5% by mass is obtained at the temperature at which the water-soluble polymer is most dissolved. It means that the mass of the insoluble matter that is separated by filtration through pores of 40 to 50 μm is within 50 mass% of the added water-soluble polymer.

Polymers having reactive functional groups Examples of polymers having reactive functional groups that can be used in the present invention include unmodified polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymers, and potassium acrylate. -Acrylic resins such as acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid Styrene acrylic resin such as acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-styrene sulfone Sodium acid salt Styrene-2-hydroxyethyl acrylate copolymer, styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic Vinyl acetate copolymers such as acid copolymers, vinyl naphthalene-maleic acid copolymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and These salts are mentioned. Among these, it is preferable to use unmodified polyvinyl alcohols, polyvinyl pyrrolidones, and copolymers thereof.

  The form of the copolymer when the polymer having the reactive functional group is a copolymer may be any of a block copolymer, a random copolymer, a graft copolymer, and an alternating copolymer. Good.

Modified Polyvinyl Alcohol The modified polyvinyl alcohol that can be used in the present invention is one obtained by subjecting unmodified polyvinyl alcohol to one or more arbitrary modification treatments. Examples thereof include amine-modified polyvinyl alcohol, ethylene-modified polyvinyl alcohol, carboxylic acid-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, thiol-modified polyvinyl alcohol, and acetal-modified polyvinyl alcohol. As these modified polyvinyl alcohols, commercially available products may be used, or those produced by methods known in the art may be used.

  Further, modified polyvinyl alcohols such as polyvinyl alcohol having a cation-modified terminal, anion-modified polyvinyl alcohol having an anionic group, and nonionic modified polyvinyl alcohol may also be used.

  Examples of the cation-modified polyvinyl alcohol include primary to tertiary amino groups and quaternary ammonium groups as described in JP-A No. 61-10383 in the main chain or side chain of the polyvinyl alcohol. It can be obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

  Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl- (2-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl- (3-acrylamido-3,3-dimethylpropyl) ammonium chloride. N-vinylimidazole, N-vinyl-2-methylimidazole, N- (3-dimethylaminopropyl) methacrylamide, hydroxyethyltrimethylammonium chloride, trimethyl- (2-methacrylamidopropyl) ammonium chloride, N- (1, 1-dimethyl-3-dimethylaminopropyl) acrylamide and the like. The ratio of the ethylenically unsaturated monomer having a cationic group of the cation-modified polyvinyl alcohol is 0.1 to 10 mol%, preferably 0.2 to 5 mol%, relative to vinyl acetate.

  Examples of the anion-modified polyvinyl alcohol include polyvinyl alcohol having an anionic group as described in JP-A-1-206088, JP-A-61-237681 and JP-A-63-307979. Examples thereof include a copolymer of vinyl alcohol and a vinyl compound having a water-soluble group, and modified polyvinyl alcohol having a water-soluble group as described in JP-A-7-285265.

  Nonionic modified polyvinyl alcohol includes, for example, a polyvinyl alcohol derivative in which a polyalkylene oxide group as described in JP-A-7-9758 is added to a part of vinyl alcohol, and JP-A-8-25795. The block copolymer of the vinyl compound and vinyl alcohol which have the described hydrophobic group is mentioned.

  Here, the unmodified polyvinyl alcohol preferably has an average degree of polymerization of about 100 to 10000, more preferably an average degree of polymerization of about 500 to 5000, and still more preferably an average degree of polymerization of about 900 to 2500. The degree of saponification of unmodified polyvinyl alcohol is preferably about 60 to 100 mol%, more preferably 78 to 99 mol%. Such a saponified polyvinyl alcohol can be produced by radical polymerization of vinyl acetate and appropriately saponifying the obtained polyvinyl acetate. In order to produce a desired unmodified polyvinyl alcohol, The polymerization degree and saponification degree are controlled by a method known per se.

  In addition, as such a partially saponified polyvinyl alcohol, it is possible to use a commercially available product. Examples of preferable commercially available unmodified polyvinyl alcohol include Gohsenol EG05, EG25 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), PVA203 ( Kuraray Co., Ltd.), PVA204 (Kuraray Co., Ltd.), PVA205 (Kuraray Co., Ltd.), JP-04 (Nippon Vinegar Pover Co., Ltd.), JP-05 (Nippon Vinegar Pover Co., Ltd.) Is mentioned. Alternatively, PVA124 (degree of saponification: 98.0 to 99.0 mol%), PVA117 (degree of saponification: 98.0 to 99.0 mol%), PVA624 (degree of saponification: 95.%) manufactured by Kuraray Co., Ltd. 0-96.0 mol%) and PVA617 (degree of saponification: 94.5-95.5 mol%); for example, AH-26 (degree of saponification: 97.0-98. 0) manufactured by Nippon Synthetic Chemical Industry Co., Ltd. 8 mol%), AH-22 (degree of saponification: 97.5-98.5 mol%), NH-18 (degree of saponification: 98.0-99.0 mol%) and N-300 (degree of saponification) : 98.0-99.0 mol%); for example, JF-17 (degree of saponification: 98.0-99.0 mol%), JF-17L (degree of saponification: 98) of Nippon Vinegar Poval Co., Ltd. 0.0-99.0 mol%) and JF-20 (degree of saponification: 98.0-99.0 mol%) It is below.

  Examples of polymerizable vinyl monomers to be polymerized with unmodified (modified) polyvinyl alcohol include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, or salts thereof (for example, alkali metals). Salts, ammonium salts, alkylamine salts), esters thereof (eg, substituted or unsubstituted alkyl esters, cyclic alkyl esters, polyalkylene glycol esters), unsaturated nitriles, unsaturated amides, aromatic vinyls, fats Group vinyls and unsaturated bond-containing heterocycles. Specifically, (a) acrylic acid esters include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, polyethylene glycol acrylate (polyethylene glycol and acrylic acid Ester) and polypropylene glycol acrylate (ester of polypropylene glycol and acrylic acid). (B) Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexyl. Methacrylate, hydroxyethyl methacrylate, polyethylene glycol Tacrylate (ester of polyethylene glycol and methacrylic acid), etc. (c) Unsaturated nitriles such as acrylonitrile, methacrylonitrile, etc. (d) Unsaturated amides such as acrylamide, dimethylacrylamide, methacrylamide (E) aromatic vinyls such as styrene, α-methylstyrene, (f) aliphatic vinyls such as vinyl acetate, and (g) unsaturated bond-containing heterocycles such as N -Vinylpyrrolidone, acryloylmorpholine and the like are exemplified.

  The above-mentioned modified polyvinyl alcohol can be produced by modifying unmodified polyvinyl alcohol or a derivative thereof by a method known per se.

  In particular, examples of the method for producing the graft copolymer as the modified polyvinyl alcohol include methods known per se such as radical polymerization, for example, solution polymerization, suspension polymerization, emulsion polymerization and bulk polymerization. It can be carried out under normal polymerization conditions. This polymerization reaction is usually performed in the presence of a polymerization initiator, if necessary, as a reducing agent (for example, sodium erythorbate, sodium metabisulfite, ascorbic acid), a chain transfer agent (for example, 2-mercaptoethanol, α-methylstyrene). In the presence of a dimer, 2-ethylhexylthioglycolate, lauryl mercaptan) or a dispersant (for example, a surfactant such as sorbitan ester or lauryl alcohol), water, an organic solvent (for example, methanol, ethanol, cellosolve, carbitol) or the like In a mixture of Moreover, the removal method of an unreacted monomer, drying, a grinding | pulverization method, etc. may be a well-known method, and there is no restriction | limiting in particular.

Gelatin Gelatin that can be used in the present invention includes various gelatins that have been widely used in the field of silver halide photographic materials. For example, in addition to acid-treated gelatin and alkali-treated gelatin, enzyme-treated gelatin and gelatin derivatives that undergo enzyme treatment in the gelatin production process, that is, amino, imino, hydroxy, or carboxy groups as functional groups in the molecule It may be modified by treating with a reagent having a group obtained by reacting with it. The general method for producing gelatin is well known and is described, for example, in T.W. H. James: The Theory of Photographic Process 4th. ed. Reference can be made to descriptions such as 1977 (Maccillan), p. 55, Science Photo Handbook (above), p. 72-75 (Maruzen Co., Ltd.), Photographic Engineering Basics-Silver Salt Photography, p. 119-124 (Corona). . Also, Research Disclosure Magazine Vol. 176, No. The gelatin described in IX page of 17643 (December, 1978) can be mentioned.

Thickening polysaccharide There is no restriction | limiting in particular as thickening polysaccharide used by this invention, For example, generally known natural simple polysaccharide, natural complex polysaccharide, synthetic simple polysaccharide, synthetic complex polysaccharide, etc. are mentioned. be able to. For details of these thickening polysaccharides, reference can be made to “Biochemical Dictionary (2nd edition)” (Tokyo Kagaku Dojin), “Food Industry”, Vol. 31 (1988), p.

  The thickening polysaccharide is a polymer of saccharides and has a large number of hydrogen bonding groups in the molecule. Due to the difference in hydrogen bonding strength between molecules depending on the temperature, the viscosity at low temperature and the viscosity at high temperature are different. It is a polysaccharide with the characteristic that the difference is large, and when metal oxide particles or polyvalent metal compounds are added, the metal oxide particles or polyvalent metals react with the metal oxide particles or polyvalent metal compounds at low temperatures. It forms a hydrogen bond or ionic bond with the compound, causing an increase in viscosity or gelation. The increase in viscosity is preferably 1.0 mPa · s or more at 15 ° C. compared to the viscosity at 15 ° C. before the addition of the metal oxide particles or the polyvalent metal compound. The viscosity increase width is more preferably 5.0 mPa · s or more, and further preferably 10.0 mPa · s or more.

  More specific examples of thickening polysaccharides applicable to the present invention include, for example, pectin, galactan (eg, agarose, agaropectin, etc.), galactomannoglycan (eg, locust bean gum, guaran, etc.), xyloglucan, etc. (Eg, tamarind gum, tamarind seed gum, etc.), glucomannoglycan (eg, salmon mannan, wood-derived glucomannan, xanthan gum, etc.), galactoglucomannoglycan (eg, softwood-derived glycan), arabinogalactoglycan ( For example, soybean-derived glycans, microbial-derived glycans, etc.), glucoraminoglycans (eg, gellan gum, etc.), glycosaminoglycans (eg, hyaluronic acid, keratan sulfate, etc.), alginic acid and alginate, agar, κ-carrageenan, λ -Carrageenan, ι Carrageenan, natural polymer polysaccharides, carboxymethylcellulose derived from red algae such as furcellaran (cellulose carboxymethyl ether), carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, celluloses such as hydroxypropyl cellulose can be mentioned. From the viewpoint of not reducing the dispersion stability of the metal oxide particles that can coexist in the coating solution, those in which the structural unit does not have a carboxylic acid group or a sulfonic acid group are preferable. Such polysaccharides include, for example, pentoses such as L-arabitose, D-ribose, 2-deoxyribose and D-xylose, and hexoses such as D-glucose, D-fructose, D-mannose and D-galactose only. It is preferable that it is a polysaccharide. Specifically, tamarind seed gum known as xyloglucan whose main chain is glucose and side chain is glucose, guar gum known as galactomannan whose main chain is mannose and side chain is glucose, cationized guar gum, Hydroxypropyl guar gum, locust bean gum, tara gum, and arabinogalactan whose main chain is galactose and whose side chain is arabinose can be preferably used.

  The above polymers may be used alone or in combination of two or more.

  The mass average molecular weight of the polymer is not particularly limited, but 5000 to 1000000 can be preferably used. In the present specification, the mass average molecular weight is a gel permeation chromatography (GPC) analyzer (solvent: tetrahydrofuran (THF)) using a column of TSKgel GMHxL, TSKgel G4000HxL or TSKgel G2000HxL (manufactured by Tosoh Corporation). ) Means the molecular weight expressed in terms of polystyrene by differential refractometer detection.

  Moreover, although the density | concentration of the polymer in a coating liquid can be changed suitably according to the kind of polymer, it is preferable that it is 0.01-20 mass%, and it is 0.1-10 mass%. Is more preferable, and it is further more preferable that it is 3-9.5 mass%. It is preferable for the concentration of the polymer to be in the above range since the coating solution has a certain viscosity and can be advantageous for film formation. In view of the efficiency of removing bubbles, a lower concentration is preferable.

(solvent)
The solvent that can be used in the present invention is not particularly limited, and examples thereof include water, an organic solvent, or a mixed solvent thereof.

  Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol, and 1-butanol; esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; diethyl ether; Examples thereof include ethers such as propylene glycol monomethyl ether and ethylene glycol monoethyl ether; amides such as dimethylformamide and N-methylpyrrolidone; ketones such as acetone, methyl ethyl ketone, acetylacetone and cyclohexanone. These organic solvents may be used alone or in admixture of two or more. From the viewpoint of environment and simplicity of operation, the solvent of the coating solution is preferably water or a mixed solvent of water and methanol, ethanol, or ethyl acetate, and more preferably water.

(Crosslinking agent)
The crosslinking agent has a function of curing the polymer. By curing, water resistance can be imparted to the refractive index layer.

  The crosslinking agent that can be used is not particularly limited as long as it causes a curing reaction with a polymer. For example, when the polymer is unmodified polyvinyl alcohol or modified polyvinyl alcohol, boric acid and its salt (oxygen acid and its salt centered on a boron atom), specifically, orthoboric acid and diboric acid , Metaboric acid, tetraboric acid, pentaboric acid, and octaboric acid or salts thereof are preferably used. Boric acid and its salt may be used alone or in admixture of two or more, and it is particularly preferable to use a mixed aqueous solution of boric acid and borax. Other known compounds can also be used, and are generally compounds having a group capable of reacting with a polymer, or compounds that promote the reaction between different groups of a resin. It is appropriately selected and used accordingly. Specific examples of the crosslinking agent include, for example, diglycidyl ethyl ether, ethylene glycol diglycidyl ether, 1,4-dibutanediol diglycidyl ether, 1,6-diglycidyl cyclohexane, N, N-diglycidyl-4- Epoxy crosslinking agents such as glycidyloxyaniline, sorbitol polyglycidyl ether, glycerol polyglycidyl ether; aldehyde crosslinking agents such as formaldehyde and glycoxal; 2,4-dichloro-4-hydroxy-1,3,5- Active halogen-based crosslinking agents such as S-triazine; 1.3.5-tris-acryloyl-hexahydro-S-triazine, active vinyl-based compounds such as bisvinylsulfonylmethyl ether; aluminum alum and the like.

  When gelatin is used as the resin, examples of the crosslinking agent include organic compounds such as vinylsulfone compounds, urea-formalin condensates, melanin-formalin condensates, epoxy compounds, aziridine compounds, active olefins, and isocyanate compounds. Hardeners, inorganic polyvalent metal salts such as chromium, aluminum and zirconium may be used.

  The concentration of the crosslinking agent in the coating solution is preferably 0.001 to 20% by mass, and more preferably 0.01 to 10% by mass. When the crosslinking agent is in the above range, the coating solution has a certain spinnability and viscosity, which is advantageous for film formation, and the formed refractive index layer can have suitable water resistance.

(Metal oxide particles)
The metal oxide particles which can be used is not particularly limited, titanium oxide _(TiO 2), zinc oxide (ZnO), zirconium oxide _(ZrO 2), niobium oxide _{(Nb 2 O} 5), aluminum oxide _(Al 2 O ₃ ), silicon oxide (SiO ₂ ), calcium fluoride (CaF ₂ ), magnesium fluoride (MgF ₂ ), indium tin oxide (ITO), antimony tin oxide (ATO), and the like. Of these, titanium oxide (TiO ₂ ) is preferably used for the high refractive index layer coating solution, and silicon oxide (SiO ₂ ) is preferably used for the low refractive index layer coating solution.

As the titanium oxide (TiO ₂ ), it is particularly preferable to use a rutile type titanium oxide having a high refractive index and low catalytic activity. If the catalytic activity is low, side reactions (photocatalytic reactions) that occur in the refractive index layer and adjacent layers can be suppressed, and the weather resistance can be increased.

  In addition, the titanium oxide should be prepared by hydrophobizing the surface of an aqueous titanium oxide sol having a pH of 1.0 to 3.0 and a positive zeta potential of titanium particles so that the surface can be dispersed in an organic solvent. preferable. Examples of the method for preparing the aqueous titanium oxide sol include Japanese Patent Laid-Open Nos. 63-17221, 7-819, 9-165218, 11-43327, and 63. Reference can be made to the matters described in JP-A-17221, JP-A-7-819, JP-A-9-165218, JP-A-11-43327, and the like.

  As for other production methods of titanium oxide particles, for example, the method described in “Titanium oxide—physical properties and applied technology” (Kagino Seino p255-258 (2000) Gihodo Publishing Co., Ltd.), or WO2007 / 039953 The method of the step (2) described in paragraphs “0011” to “0023” of the book can be referred to. The production method according to this step (2) is a step of treating titanium dioxide hydrate with at least one basic compound selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides. The titanium dioxide dispersion obtained in (1) is treated with a carboxylic acid group-containing compound and an inorganic acid. In the present invention, an aqueous sol of titanium oxide having a pH adjusted to 1.0 to 3.0 with an inorganic acid in step (2) can be used.

Examples of the silicon oxide (SiO ₂ ) include synthetic amorphous silica and colloidal silica. Among these, it is more preferable to use an acidic colloidal silica sol, and it is more preferable to use a colloidal silica sol dispersed in water and / or an organic solvent. The colloidal silica can be obtained by heating and aging a silica sol obtained by metathesis with an acid of sodium silicate or the like and passing through an ion exchange resin layer. Such colloidal silicas are disclosed in, for example, JP-A-57-14091, JP-A-60-219083, JP-A-60-219084, JP-A-61-20792, JP-A-61- No. 188183, JP-A-63-17807, JP-A-4-93284, JP-A-5-278324, JP-A-6-92011, JP-A-6-183134, JP-A-6-297830 No. 7, JP-A-7-81214, JP-A-7-101142, JP-A-7-179029, JP-A-7-137431, International Publication No. 94/26530, etc. . Colloidal silica may be a synthetic product or a commercially available product.

  The metal oxide particles may be used alone or in combination of two or more.

  The average particle size of the metal oxide particles is preferably 2 to 100 nm, more preferably 3 to 50 nm, and further preferably 4 to 30 nm. The average particle size of the metal oxide particles is determined by observing the particles themselves or the particles appearing on the cross section or surface of the refractive index layer with an electron microscope, measuring the particle size of 1000 arbitrary particles, and calculating the simple average value ( (Number average). Here, the particle diameter of each particle is represented by a diameter assuming a circle equal to the projected area.

  The concentration of the metal oxide particles in the coating solution is preferably 20 to 70% by mass and more preferably 30 to 70% by mass with respect to 100% by mass of the solid content of the refractive index layer. It is preferable that the content of the metal oxide particles is 20% by mass or more because a desired refractive index can be obtained. Further, it is preferable that the content of the metal oxide particles is 70% by mass or less because flexibility of the film can be obtained and film formation becomes easy.

  In addition, when both refractive index layers having different refractive indexes (for example, a high refractive index layer and a low refractive index layer) include metal oxide particles, anionization treatment or cationization treatment is performed, and the metal oxide particles It is preferable to have the same ionicity (charge). By performing anionization treatment or cationization treatment, a repulsive force is generated between the two types of metal oxide particles. For example, when a refractive index layer is formed by multilayer coating, aggregation at the layer interface, etc. Can be difficult to occur.

  As an anionization treatment of metal oxide particles, for example, anion treatment of titanium oxide is exemplified, and the titanium oxide particles can be anionized by coating with a silicon-containing hydrated oxide. The coating amount of the silicon-containing hydrated compound is usually 3 to 30% by mass, preferably 3 to 10% by mass, and more preferably 3 to 8% by mass. When the coating amount is 30% by mass or less, a desired refractive index of the high refractive index layer can be obtained, and when the coating amount is 3% or more, particles can be stably formed.

  The cationization treatment of the metal oxide particles can be performed by using, for example, a cationic compound. Examples of the cationic compound include a cationic polymer and a polyvalent metal salt, and a polyvalent metal salt is preferred from the viewpoint of adsorption power and transparency. Examples of polyvalent metal salts include aluminum, calcium, magnesium, zinc, iron, strontium, barium, nickel, copper, scandium, gallium, indium, titanium, zirconium, tin, lead, and other metal hydrochlorides, sulfates, nitrates, Examples include acetate, formate, succinate, malonate, chloroacetate and the like. Of these, water-soluble aluminum compounds, water-soluble calcium compounds, water-soluble magnesium compounds, water-soluble zinc compounds, and water-soluble zirconium compounds are preferably used, and water-soluble aluminum compounds and water-soluble zirconium compounds are more preferably used. Specific examples of the water-soluble aluminum compound include polyaluminum chloride (basic aluminum chloride), aluminum sulfate, basic aluminum sulfate, aluminum potassium sulfate (alum), ammonium aluminum sulfate (ammonium alum), sodium aluminum sulfate, aluminum nitrate, Examples thereof include aluminum phosphate, aluminum carbonate, polysulfuric acid aluminum silicate, aluminum acetate, and basic aluminum lactate. The coating amount of the cationic compound varies depending on the shape and particle size of the metal oxide particles, but is preferably 1% by mass to 15% by mass with respect to the metal oxide particles.

(Emulsion resin)
The emulsion resin is usually a polymer dispersed in a coating solution. The emulsion resin is obtained by emulsion polymerization of an oil-soluble monomer using a polymer dispersant or the like.

  Oil-soluble monomers that can be used are not particularly limited, but ethylene, propylene, butadiene, vinyl acetate and its partial hydrolyzate, vinyl ether, acrylic acid and its esters, methacrylic acid and its esters, acrylamide and its derivatives, Examples thereof include methacrylamide and derivatives thereof, styrene, divinylbenzene, vinyl chloride, vinylidene chloride, maleic acid, vinyl pyrrolidone and the like. Of these, acrylic acid, its esters, and vinyl acetate are preferably used from the viewpoint of transparency and particle size.

  As acrylic acid and / or its esters and vinyl acetate emulsion, commercially available ones may be used, for example, Acryt UW-309, UW-319SX, UW-520 (manufactured by Taisei Fine Chemical Co., Ltd.), and Mobile vinyl (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like.

  Further, the dispersant that can be used is not particularly limited, but in addition to a low-molecular dispersant such as alkyl sulfonate, alkylbenzene sulfonate, diethylamine, ethylenediamine, and quaternary ammonium salt, polyoxyethylene nonylphenyl is used. Examples thereof include polymer dispersants such as ether, polyethylene ethylene laurate, hydroxyethyl cellulose, and polyvinyl pyrrolidone.

  The emulsion described above preferably has a glass transition temperature (Tg) of 20 ° C. or lower, more preferably −30 to 10 ° C., from the viewpoint of enhancing flexibility.

(Other additives)
As a preferable embodiment of the present invention, other additives applicable to the refractive index layer that can be used in the optical film are listed below. For example, various surfactants such as ultraviolet absorbers, anions, cations, or nonions described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, sulfuric acid, PH adjusters such as phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide and potassium carbonate, antifoaming agents, lubricants such as diethylene glycol, preservatives, antifungal agents, antistatic agents, matting agents, antioxidants And various known additives such as additives, flame retardants, infrared absorbers, dyes and pigments.

  In this invention, the manufacturing method of the optical film which has the process of apply | coating the coating liquid manufactured using said coating liquid feeding system on a base material, and the process of drying the coating liquid on the said base material Is provided. This will be described in detail below.

[Preparation of coating solution]
The method for preparing the coating solution is not particularly limited, and examples thereof include a method in which a polymer and, if necessary, an additive such as a crosslinking agent and metal oxide particles are added to a solvent and mixed by stirring. At this time, the order of addition of the respective components is not particularly limited, and the respective components may be sequentially added and mixed while stirring, or may be added and mixed at one time while stirring.

[Base material]
The substrate applied to the optical film of the present invention is not particularly limited, and a known resin film can be used. Specifically, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyarylate, polymethyl methacrylate, polyamide, polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate. Examples include phthalate (PEN), polysulfone, polyethersulfone, polyetheretherketone, polyimide, aromatic polyamide, and polyetherimide. Of these, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), and the like are preferably used from the viewpoints of cost and availability.

  The substrate using the resin film may be an unstretched film or a stretched film, but in the case of a resin film having crystallinity such as PET or PEN, the strength is improved. From the viewpoint of suppressing thermal expansion, a film that is heat-set after stretching is preferred.

  The base material using the resin film can be produced by a conventionally known general method. For example, an unstretched film that is substantially amorphous and not oriented can be produced by melting a resin as a material with an extruder, extruding it with an annular die or a T-die, and quenching. Further, the unstretched film is subjected to a known method such as uniaxial stretching, tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, tubular-type simultaneous biaxial stretching, and the resin film flow (vertical axis) direction, and / or Alternatively, a stretched film can be produced by stretching in the direction perpendicular to the flow direction of the resin film (horizontal axis). The draw ratio in this case can be appropriately selected according to the resin as the raw material of the substrate, but is preferably 2 to 10 times in the vertical axis direction and the horizontal axis direction, respectively.

  The thickness of the substrate according to the present invention is preferably 5 to 300 μm, and more preferably 15 to 150 μm. Moreover, the base material may be a laminate of two or more, and in this case, the type of the base material may be the same or different.

  In addition, the base material may be subjected to relaxation treatment and off-line heat treatment from the viewpoint of dimensional stability. It is preferable that the relaxation treatment is performed in the process from the heat setting in the stretching process of the resin film to the winding in the transversely stretched tenter or after exiting the tenter. The relaxation treatment is preferably performed at a treatment temperature of 80 to 200 ° C, more preferably 100 to 180 ° C. Further, in both the longitudinal direction and the width direction, the relaxation rate is preferably processed to 0.1 to 10%, more preferably 2 to 6%. The relaxed base material is further subjected to off-line heat treatment to improve heat resistance and further improve dimensional stability.

The substrate is preferably provided with an undercoat layer on one side or both sides during the film forming process. The undercoat layer can be formed in-line or after film formation. Examples of the method for forming the undercoat layer include a method of applying an undercoat layer coating solution and drying the obtained coating film. The undercoat layer coating solution usually contains a resin. Examples of the resin include polyester resins, acrylic-modified polyester resins, polyurethane resins, acrylic resins, vinyl resins, vinylidene chloride resins, polyethyleneimine vinylidene resins, polystyrene butadiene resins, polyethyleneimine resins, polyvinyl alcohol, and gelatin. . A known additive may be further added to the undercoat layer coating solution. The coating amount of the undercoat layer coating solution is preferably applied so as to be about 0.01 to ² g / m ² in a dry state. The coating method of the undercoat layer coating solution is not particularly limited, and known methods such as a roll coating method, a gravure coating method, a knife coating method, a dip coating method, and a spray coating method can be used. The obtained coating film may be stretched. Usually, an undercoat layer can be formed by drying at 80 to 120 ° C. while performing lateral stretching in a tenter after coating a coating solution. The undercoat layer may have a single layer structure or a laminated structure.

  The substrate according to the present invention further includes a conductive layer, an antistatic layer, a gas barrier layer, an easy adhesion layer (adhesion layer), an antifouling layer, a deodorant layer, a droplet layer, an easy slip layer, a hard coat layer, and wear resistance. May have a known functional layer such as an adhesive layer, an adhesive layer, and an interlayer film layer.

  When a base material has intermediate layers, such as the above-mentioned undercoat layer and a functional layer, it is preferable that the total film thickness of a base material and an intermediate layer is 5-500 micrometers, and it is more preferable that it is 25-250 micrometers. preferable.

[Application]
In the coating apparatus, the coating liquid is applied to the substrate at a predetermined temperature and a predetermined speed to form a coating film.

  The coating method of the coating liquid is not particularly limited, and for example, roll coating method, rod bar coating method, air knife coating method, spray coating method, curtain coating method, or US Pat. No. 2,761,419, US The slide bead coating method using the hopper described in Japanese Patent No. 2,761,791 and the extrusion coating method are preferably used.

  When the coating method is simultaneous multi-layer coating using a slide bead coating method, the viscosity of the coating solution is preferably 1 to 2000 mPa · s, and more preferably 1 to 1000 mPa · s.

  The coating temperature is preferably 20 to 60 ° C. A coating temperature of 60 ° C. or lower is preferable because facilities for keeping the coating solution at a high temperature can be relatively simplified and costs can be reduced. On the other hand, it is preferable that the coating temperature is 20 ° C. or higher because a facility for cooling the coating solution becomes unnecessary, the cost can be suppressed, and the safety of the work can be improved.

  The coating speed is preferably 1 m / min or more, and more preferably 1 to 500 m / min. A coating speed of 1 m / min or more is preferable because high productivity can be obtained.

[Dry]
In the drying apparatus, the refractive index layer can be formed by drying the coating film.

  The drying method is not particularly limited, and may be performed by a known method. Examples of the drying method include natural drying, heat drying, a method of applying hot air, a method of applying cold air, and the like. From the viewpoint of rapid drying, it is preferable to perform drying by heat drying. At this time, the heating temperature varies depending on the composition of the formed coating film and the like, but is preferably 15 to 120 ° C, more preferably 20 to 90 ° C.

[cooling]
In the production of the optical film, the coating film formed on the substrate may be cooled once before drying. By cooling, the surface of the refractive index layer (the interface when stacked) can be made more uniform.

  Since the coating film immediately after application has a low viscosity, for example, when hot air is applied to the coating film immediately after application and dried, the surface of the obtained refractive index layer may vary in film thickness due to the hot air. In addition, when the multilayer coating is performed, the coating film component moves between the layers, and the boundary between the obtained refractive index layers may be so vague that it adversely affects the optical performance. However, once the obtained coating film is cooled, the viscosity of the coating film increases rapidly, and the coating film can be stabilized. As a result, it is possible to suppress the occurrence of film thickness variation due to drying of hot air or the like, and the movement of coating film components between layers. However, since the performance of the infrared shielding film may be different depending on the movement of the coating component between layers, whether or not to perform cooling can be appropriately determined according to the desired performance of the infrared shielding film.

  In the case of cooling, it is preferable to use a polymer whose viscosity is easily increased by cooling the coating film as a component of the coating solution. As described above, the viscosity can be generated by bonding between end groups of the polymer in the coating liquid and within the molecule, bonding in the cross-linking agent, entanglement between molecules, and the like. Therefore, it is preferable to use a polymer having a large number of functional groups or a polymer having a large molecular weight as a component of the coating solution and including a crosslinking agent.

  Although cooling temperature changes also with the coating liquid to be used, it is preferable that it is -20-20 degreeC, and it is more preferable that it is -5-10 degreeC.

<Application>
The infrared shielding film obtained above can be applied to a wide range of fields. For example, pasting to facilities exposed to sunlight for a long time, such as outdoor windows of buildings and automobile windows, films for window pasting such as infrared shielding films that give an infrared shielding effect, films for agricultural greenhouses, etc. As, it is mainly used for the purpose of improving the weather resistance.

  In particular, the infrared shielding film can be suitably applied to a member in which the infrared shielding film according to the present invention is bonded to a substrate such as glass or a glass substitute resin directly or via an adhesive.

  That is, according to still another aspect of the present invention, there is also provided an infrared shielding body in which the above infrared shielding film is provided on at least one surface of a substrate.

  Specific examples of the substrate include, for example, glass, polycarbonate resin, polysulfone resin, acrylic resin, polyolefin resin, polyether resin, polyester resin, polyamide resin, polysulfide resin, unsaturated polyester resin, epoxy resin, melamine resin, Examples thereof include phenol resin, diallyl phthalate resin, polyimide resin, urethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, styrene resin, vinyl chloride resin, metal plate, ceramic and the like. The type of the resin may be any of a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin, and two or more of these may be used in combination. The substrate that can be used in the present invention can be produced by a known method such as extrusion molding, calendar molding, injection molding, hollow molding, compression molding and the like. The thickness of the substrate is not particularly limited, but is usually 0.1 mm to 5 cm.

  The adhesive layer or adhesive layer that bonds the infrared shielding film and the substrate is preferably provided with the infrared shielding film on the sunlight (heat ray) incident surface side. In addition, it is preferable to sandwich the infrared shielding film according to the present invention between a window glass and a substrate because it can be sealed from surrounding gas such as moisture and has excellent durability. Even if the infrared shielding film according to the present invention is installed outdoors or outside a car (for external application), it is preferable because of environmental durability.

  As an adhesive applicable to the present invention, an adhesive mainly composed of a photocurable or thermosetting resin can be used.

  The adhesive preferably has durability against ultraviolet rays, and is preferably an acrylic adhesive or a silicone adhesive. Furthermore, an acrylic adhesive is preferable from the viewpoint of adhesive properties and cost. In particular, a solvent system is preferable in the acrylic pressure-sensitive adhesive because the peel strength can be easily controlled. When a solution polymerization polymer is used as the acrylic solvent-based pressure-sensitive adhesive, known monomers can be used as the monomer.

  Moreover, you may use the polyvinyl butyral resin used as an intermediate | middle layer of a laminated glass, or ethylene-vinyl acetate copolymer type resin. Specifically, plastic polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., Mitsubishi Monsanto Co., Ltd.), ethylene-vinyl acetate copolymer (manufactured by DuPont, Takeda Pharmaceutical Co., Ltd., duramin), modified ethylene-vinyl acetate copolymer (Mersen G, manufactured by Tosoh Corporation). In addition, you may add and mix | blend an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a lubricant, a filler, coloring, an adhesion adjusting agent etc. suitably in a contact bonding layer.

  Insulation performance and solar heat shielding performance of an infrared shielding film or an infrared shielding body are generally JIS R 3209 (multi-layer glass), JIS R 3106 (obtain transmittance, reflectance, emissivity, and solar heat of glass sheets). Rate test method) and JIS R 3107 (calculation method of thermal resistance of plate glass and heat transmissivity in architecture).

  The solar transmittance, solar reflectance, emissivity, and visible light transmittance are measured by (1) using a spectrophotometer having a wavelength (300 to 2500 nm) to measure the spectral transmittance and spectral reflectance of various single plate glasses. Further, the emissivity is measured using a spectrophotometer having a wavelength of 5.5 to 50 μm. In addition, a predetermined value is used for the emissivity of float plate glass, polished plate glass, mold plate glass, and heat ray absorbing plate glass. (2) The solar transmittance, solar reflectance, solar absorption rate, and modified emissivity are calculated according to JIS R 3106 by calculating the solar transmittance, solar reflectance, solar absorption rate, and vertical emissivity. The corrected emissivity is obtained by multiplying the coefficient shown in JIS R 3107 by the vertical emissivity. The heat insulation and solar heat shielding properties are calculated by (1) calculating the thermal resistance of the multilayer glass according to JIS R 3209 using the measured thickness value and the corrected emissivity. However, when the hollow layer exceeds 2 mm, the gas thermal conductance of the hollow layer is determined in accordance with JIS R 3107. (2) The heat insulation is obtained by adding a heat transfer resistance to the heat resistance of the double-glazed glass and calculating the heat flow resistance. (3) Solar heat shielding properties are calculated by obtaining the solar heat acquisition rate according to JIS R 3106 and subtracting from 1.

  Moreover, since the infrared shielding film obtained above is thinned, it may be applied to the surface of a display panel. For example, in a plasma display panel, an infrared shielding film can be bonded to a highly transparent PET film and introduced into a display screen. This shields infrared rays radiated from the plasma display panel, which can contribute to protection of the human body, prevention of malfunction between electronic devices, prevention of malfunction of the remote control, and the like.

  As described above, the coating liquid feeding system of the present invention further includes a drying device for drying the coating film coated on the substrate, and the coating liquid is coated and dried on the substrate. By repeating a plurality of times, it is possible to produce a laminate in which a plurality of coating films are formed on a substrate.

  Then, such a laminate is formed by alternately laminating a high refractive index layer and a low refractive index layer, each having a different refractive index, and at least one of the high refractive index layer and the low refractive index layer, By including metal oxide particles and a water-soluble resin, it can be used as an infrared shielding film.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

  First, the entire flow from preparation of a coating solution containing a polymer to production of a coating film (polymer film) will be described. As shown in FIG. 4, the coating liquid is prepared by adding the raw material to the coating liquid preparation pot 101 equipped with a decompression device. At this time, bubbles are usually mixed. The bubbles are removed by a decompression process using a decompression device. Then, the coating liquid from which bubbles have been removed is supplied to the coating liquid storage tank 104 by using the liquid feeding device 102 without passing through the filtering device 103. Check the number of bubbles at this stage. This is evaluated by <presence / absence of bubbles in liquid visually> described later.

  Next, the coating solution in the coating solution storage tank 104 is supplied to the dispersion device 106 using the liquid feeding device 105, supplied to the filtration device 108 without passing through the defoaming device 107, and then again using the circulation path R1. Return to the coating liquid storage pot 104. This circulation process is repeated.

  Finally, a coating film (polymer film) is produced by the coating device 114 and the drying device 116 using the coating liquid that has undergone the circulation treatment. Also check the number of bubbles at this stage. This is evaluated in <Coating failure of coating film> described later.

  To summarize more simply: A coating solution is prepared and the viscosity is measured (a). 2. A decompression process is performed. 3. After completion of the decompression process, the viscosity measurement is measured (b). 3. Deliver the solution. It stores in a storage pot, At this time, dissolved oxygen amount measurement (c), viscosity measurement (d), and bubble number confirmation (e) are performed. 4. Deliver the solution. Shearing is performed. 5. Pump the solution. Perform filtration. 6. Perform liquid feeding (circulation path R1); Store in storage pot. 8). Circulation is repeated 5 to 7, the circulation is terminated and viscosity measurement (f) is performed. 8. Pump the solution. Apply. 10. Dry and perform coating failure evaluation (g). Hereinafter, specific operations will be described in detail.

<Example 1>
Polyvinyl alcohol (PVA-124, adjusted to a concentration of 7.4% by mass in a coating liquid preparation kettle 101 having a kettle inner diameter φ0.95 m equipped with a pressure reducing device and an agitating device (pot with a depressurizable lid: vacuum levitation tank). 500L aqueous solution (average polymerization degree 2400, saponification degree 98-99 mol%, manufactured by Kuraray Co., Ltd.) was added and heated to 40 ° C. to prepare coating liquid 1. The coating solution 1 had a viscosity of 450 mPa · s (a). In addition, let the viscosity in this specification be a value obtained from the measurement by a rotary viscometer (Brookfield digital viscometer DV-E). In addition, the temperature of the coating liquid is maintained at 40 ° C. throughout all the examples and comparative examples.

  Air bubbles are mixed in the coating liquid 1. Therefore, the coating liquid 1 was subjected to a decompression process for 30 minutes at a reduced pressure of 100 Torr while stirring at a peripheral speed of 0.5 m / sec with four pitched paddle blades having a blade diameter of 475 mm by a stirring device. Got. The viscosity of the coating solution 1 subjected to the pressure reduction treatment was 450 mPa · s (b).

  Subsequently, the coating liquid storage tank 104 having a pot inner diameter of 0.95 m was subjected to a decompression process at a flow rate of 20 L / min using a rotary pump as the liquid feeding apparatus 102 (without passing through the filtration apparatus 103). Coating solution 1 was supplied and stored. The dissolved oxygen amount at this time was 3.1 mg / L (c). In addition, let the amount of dissolved oxygen of this specification be a value obtained from the measurement by a dissolved oxygen meter (DO meter B-506 by Iijima Electronics). Moreover, the viscosity of the coating liquid 1 stored in this storage pot was 430 mPa · s (d). In addition, the number of bubbles was confirmed at this stage (<presence / absence of bubbles in the liquid visually>: (e)).

  Subsequently, the coating solution stored in the coating solution storage tank 104 is fed to a dispersing device Milder MDN306V (dispersing device 106) at a flow rate of 20 L / min using a rotary pump as the feeding device 105 and subjected to a shearing process. went. Such a dispersing device is a milder processing device with a standard type of rotor and stator. Using such a milder processing apparatus, the rotor was rotated at a rotational speed of 5000 rpm, and the coating liquid 1 subjected to the decompression process was subjected to a shearing process.

  Subsequently, the coating liquid 1 was filtered by the filtration device 108. Filtration was performed by passing the coating liquid 1 through the filter at a flow rate of 20 L / min using a filter 250L-SLP-200 (manufactured by Loki Techno Co., Ltd.) and a rotary pump. The filtration pressure was 0.05 to 0.1 MPa.

  The coating liquid 1 subjected to the filtration treatment was returned again to the coating liquid storage tank 104 through the circulation path R1. This circulation process was carried out for 30 minutes to obtain a coating solution 1 subjected to the circulation process. The viscosity of the coating liquid 1 subjected to this circulation step was 400 mPa · s (f).

  Finally, the coating liquid 1 subjected to the circulation process is supplied from the filtration device 108 to the slide coater coating device as the coating device 114 through the supply path L1, and the PET having a thickness of 100 μm is used by using the slide coater coating device. The coating liquid 1 was applied onto the substrate made of the above at a speed of 50 m / min, and dried at 50 ° C. using the drying device 116 to prepare the coating film 1. Even at this stage, the number of bubbles was confirmed (<Coating failure of coating film>: (g)).

<Example 2>
A coating solution 2 was prepared in the same manner as in the preparation of the coating solution 1 except that the concentration was 8.0% by mass.

  The viscosity of the prepared coating solution 2 was 650 mPa · s (a). Moreover, the viscosity of the coating liquid 2 subjected to the decompression treatment was 650 mPa · s (b). Moreover, the dissolved oxygen amount was 3.4 mg / L (c). Moreover, the viscosity of the coating liquid 2 stored in the storage pot was 620 mPa · s (d). Moreover, the viscosity of the coating liquid 2 subjected to the circulation treatment was 600 mPa · s (f).

<Example 3>
A coating solution 3 was prepared in the same manner as in the preparation of the coating solution 1 except that the concentration was 8.5% by mass, and a coating film 3 was produced in the same manner as in Example 1.

  The viscosity of the prepared coating solution 3 was 850 mPa · s (a). Moreover, the viscosity of the coating liquid 3 subjected to the decompression treatment was 840 mPa · s (b). Moreover, the dissolved oxygen amount was 3.9 mg / L (c). Moreover, the viscosity of the coating liquid 3 stored in the storage pot was 820 mPa · s (d). Moreover, the viscosity of the coating liquid 3 subjected to the circulation treatment was 800 mPa · s (f).

<Example 4>
The coating film 4 was prepared in the same manner as in Example 1 except that the coating liquid 4 was prepared in the same manner as the coating liquid 1 except that the concentration was 9.1% by mass, and the degree of vacuum was changed to 20 Torr. Produced.

  The prepared coating solution 4 had a viscosity of 1100 mPa · s (a). Further, the viscosity of the coating solution 4 subjected to the decompression treatment was 1100 mPa · s (b). Moreover, the dissolved oxygen amount was 3.8 mg / L (c). Moreover, the viscosity of the coating liquid 4 stored in the storage pot was 1050 mPa · s (d). Further, the viscosity of the coating solution 4 subjected to the circulation treatment was 1000 mPa · s (f).

<Example 5>
The coating film 5 was prepared in the same manner as in Example 1 except that the coating liquid 5 was prepared in the same manner as the coating liquid 1 except that the concentration was 6.0% by mass, and the degree of vacuum was changed to 400 Torr. Produced.

  The viscosity of the prepared coating solution 5 was 150 mPa · s (a). Moreover, the viscosity of the coating liquid 5 subjected to the decompression treatment was 150 mPa · s (b). Moreover, the dissolved oxygen amount was 3.0 mg / L (c). Moreover, the viscosity of the coating liquid 5 stored in the storage pot was 110 mPa · s (d). Moreover, the viscosity of the coating liquid 5 subjected to the circulation treatment was 100 mPa · s (f).

<Example 6>
A coating film 6 was produced in the same manner as in Example 1 except that the stirring speed of the coating liquid preparation kettle was changed to a peripheral speed of 0.2 m / sec.

  In addition, the viscosity of the coating liquid 6 subjected to the decompression treatment was 450 mPa · s (b). Moreover, the dissolved oxygen amount was 3.7 mg / L (c). Moreover, the viscosity of the coating liquid 6 stored in the storage pot was 410 mPa · s (d). Moreover, the viscosity of the coating liquid 6 subjected to the circulation treatment was 400 mPa · s (f).

<Example 7>
A coating film 7 was prepared in the same manner as in Example 1 except that the stirring speed of the coating liquid preparation kettle was changed to a peripheral speed of 2.0 m / sec.

  In addition, the viscosity of the coating liquid 7 subjected to the decompression treatment was 440 mPa · s (b). The dissolved oxygen amount was 4.1 mg / L (c). Moreover, the viscosity of the coating liquid 7 stored in the storage pot was 410 mPa · s (d). Moreover, the viscosity of the coating liquid 7 subjected to the circulation treatment was 400 mPa · s (f).

<Example 8>
A coating film 8 was produced in the same manner as in Example 1 except that the time for the decompression treatment in the coating solution preparation kettle was changed from 30 minutes to 10 minutes.

  In addition, the viscosity of the coating liquid 8 subjected to the decompression treatment was 450 mPa · s (b). The dissolved oxygen amount was 4.8 mg / L (c). Moreover, the viscosity of the coating liquid 8 stored in the storage pot was 410 mPa · s (d). Moreover, the viscosity of the coating liquid 8 subjected to the circulation treatment was 400 mPa · s (f).

<Example 9>
A coating film 9 was produced in the same manner as in Example 1 except that the degree of vacuum in the coating solution preparation kettle was changed from 100 Torr to 510 Torr.

  In addition, the viscosity of the coating liquid 9 subjected to the decompression treatment was 450 mPa · s (b). Moreover, the dissolved oxygen amount was 4.5 mg / L (c). Moreover, the viscosity of the coating liquid 9 stored in the storage pot was 410 mPa · s (d). Further, the viscosity of the coating liquid 9 subjected to the circulation treatment was 400 mPa · s (f).

<Comparative Example 1>
A coating film 10 was produced in the same manner as in Example 1 except that the vacuum treatment was not performed in the coating solution preparation kettle.

  The dissolved oxygen amount was 6.9 mg / L (c). Moreover, the viscosity of the coating liquid 10 stored in the storage pot was 410 mPa · s (d). Moreover, the viscosity of the coating liquid 10 subjected to the circulation treatment was 400 mPa · s (f).

<Comparative Example 2>
A coating film 11 was produced in the same manner as in Example 1 except that the circulation route was not used.

<Visual presence or absence of bubbles in the liquid>
About 1 L of the coating liquid (coating liquid) was collected (sampled) in a transparent beaker from the coating liquid storage tank 104 before passing through the circulation path, and the number of bubbles having a size of 1 mm or less was counted visually.

A: 0 / 1L
○: 1 to 5 / 1L
Δ: 6-10 pieces / 1L
×: 11-50 pieces / 1L
XX: 51-100 pieces / 1L
XXX: 101 or more / 1L
<Coating failure of coating film>
Look at the coating sample after drying of 1m x 10m, count the number of coating failures due to foam and agglomerates visually, and divide by 10 to count the number of coating failures per 1m x 1m did.

A: 0 / m ²
◯: More than 0 to 0.1 / m ²
Δ: More than 0.1 to 1.0 piece / m ²
×: More than 1.0 to 10 pieces / m ²
XX: More than 10-50 / m ²
XXX: Over 50 / m ²
The results are shown in Table 1 below.

10, 20, 30 Optical film manufacturing system,
101 preparation kettle,
102, 105, 109 liquid feeding device,
103, 108, 113 filtration device,
104 Storage pot,
106, 111 disperser,
107, 112 deaerator,
110 flow meter,
114 coating device,
115 set device,
116 drying equipment,
117 measuring device,
118 controller,
R1 circulation path,
L1 supply path,
1 stator teeth,
2 rotor teeth,
4, 5 coating solution,
La, Lb gap,
11 Valve seat,
12 Valve.

Claims (14)

A preparation kettle equipped with a pressure reducing device for preparing a coating solution containing a polymer;
A storage pot for sequentially flowing out the coating liquid prepared in the preparation pot from the preparation pot and storing the coating liquid;
A circulation path for sequentially flowing out the coating liquid stored in the storage pot from the storage pot and guiding it again to the storage pot;
A dispersing device that is provided in the middle of the circulation path and disperses the coating liquid passing through the circulation path;
A coating liquid feeding system.   The coating liquid feeding system according to claim 1, wherein the degree of pressure reduction by the pressure reducing device is 1.3332 to 66.660 kPa (10 to 500 Torr). The preparation kettle further comprises a stirring device for stirring the coating solution,
The coating liquid feeding system according to claim 1 or 2, wherein a stirring peripheral speed of the stirring device is 0.2 to 2 m / sec.   The coating liquid feeding system according to any one of claims 1 to 3, wherein a dissolved oxygen amount of the coating liquid flowing out of the preparation kettle is 1 to 5 mg / L. A measuring device for measuring physical properties of the coating solution;
The coating liquid feeding system according to any one of claims 1 to 4, wherein the dispersion device varies the dispersion strength based on a measurement value measured by the measurement device. The measuring device measures physical properties related to viscosity,
The coating apparatus according to claim 5, wherein the dispersion device increases the dispersion strength when the measured value is larger than a predetermined upper limit value and decreases the dispersion strength when the measured value is smaller than a predetermined lower limit value. Liquid feeding system.   The coating liquid feeding system according to any one of claims 1 to 6, further comprising a filtering device that is provided in the middle of the circulation path and filters the coating liquid. A coating apparatus for coating the coating liquid on a substrate;
A supply path that is connected to the storage tank or the circulation path and sequentially guides the coating liquid to the coating apparatus;
The coating liquid delivery system according to any one of claims 1 to 7, further comprising:   By making the amount of the coating liquid flowing in the system exceed the storage amount of the storage tank, the coating liquid guided through the supply path is supplied to the coating apparatus without interruption, and the coating liquid is supplied to the base. The coating liquid feeding system according to claim 8, wherein the coating liquid feeding system is continuously applied to a material.   The coating liquid feeding system according to claim 9, wherein the coating liquid prepared in the preparation kettle is fed to the storage kettle before all the coating liquid stored in the storage kettle flows out.   The said measuring apparatus is a coating liquid feeding system of any one of Claims 5-10 provided in at least one place on the said circulation path | route, the said supply path | route, and the said storage hook. A drying device for drying the coating film applied on the substrate;
The laminated body in which the coating film of a several layer is formed on a base material is produced by repeating the application | coating and drying of the said coating liquid on the said base material in multiple times. The coating liquid delivery system described in 1.   The laminate is formed by alternately laminating a high refractive index layer and a low refractive index layer, each having a different refractive index, and at least one of the high refractive index layer and the low refractive index layer is a metal oxide. The coating liquid feeding system according to claim 12, which is an infrared shielding film containing product particles and a water-soluble resin. The process of apply | coating the coating liquid manufactured using the coating liquid feeding system of any one of Claims 1-13 on a base material,
Drying the coating solution on the substrate;
The manufacturing method of the optical film which has this.