JP2009226291A - Coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method capable of efficiently removing remaining air in a liquid sending pipe when filling a coating liquid and stably carrying out coating by supplying a sufficiently degassed coating liquid to an inkjet head and stably discharging the liquid droplets out of the head. <P>SOLUTION: When filling the inkjet head with a coating liquid, the organic solvent is replaced with a degassed coating liquid using a gas-permeating film after a liquid sending line is filled with a degassed organic solvent. Further, when coating, the temperature in the side face of the inkjet head is detected, and from the detection result, the temperature of the coating liquid is controlled to be a prescribed temperature and at the same time droplets of the coating liquid are discharged to the substrate from the inkjet head to form a coating film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coating method capable of stably discharging the coating liquid when the coating liquid is discharged onto a continuously moving substrate using an inkjet head.

  2. Description of the Related Art Conventionally, there are various coating methods for coating a coating liquid on the surface of a substrate that is an object to be coated, and the coating methods are roughly divided into two. One is a pre-weighing type coating method in which a coating solution is discharged by an amount that forms a required coating solution film, and the coating solution is applied to the substrate surface. Typical examples are an extrusion coating method, a slide coating method, A curtain coating method may be used. The other is a pre-measurement type coating method in which an excess coating solution is discharged in advance than the required coating solution film formation amount, and then the excess coating solution is scraped off by some means, and a typical example is a roll coating method, Examples include an air knife coating method and a wire bar coating method.

  In general, the pre-metering type coating method has a complicated apparatus configuration, but a highly accurate coating liquid film can be obtained. In the post-metering type coating method, the apparatus structure is simple and the processing speed is high, but the former In comparison, the accuracy of the coating liquid film decreases. Here, the said high precision refers to the uniformity of the thickness of the coating liquid film in the moving direction of a base material and the direction orthogonal to a moving direction. Further, when comparing the pre-measuring type coating method and the post-measuring type coating method from the viewpoint of the consumption amount of the coating liquid, the pre-measuring type coating method is naturally less and is advantageous in terms of production efficiency.

  However, these conventional coating methods have a problem that it is difficult to obtain a highly accurate and thin coating liquid film. That is, although a relatively thin film can be obtained by the post-metering coating method, the accuracy of the coating liquid film is poor as described above. On the other hand, in the pre-metering coating method, the accuracy of the coating liquid film is relatively good, but it is difficult to obtain a thin film.

  On the other hand, there is a great increase in the need for coating films with a thin film and higher precision compared to conventional photographic materials, etc., for coated products formed with a functional coating liquid film on a substrate. ing. Under such circumstances, research is progressing to use inkjet printer technology for forming high-precision thin films of coating liquids, which are used in consumer printing equipment and the like, whose demand has been increasing in recent years. For example, a coating liquid is ejected as droplets from a nozzle by deformation of a flexible plate by a piezoelectric vibrator from an inkjet head (hereinafter also abbreviated as a head) to form a coating liquid film on a substrate and coating at a constant coverage. It is known to form a pattern in which a liquid film is arranged.

  Here, the object to be coated refers to a substrate on which a coating liquid film is formed, and the coating object refers to a substrate in which a coating liquid film is formed on the substrate.

  Formation of a coating liquid film using an inkjet head has been studied for application to various product processing methods. For example, it is a liquid crystal, a photoresist film, an overcoat film, an alignment film, a color filter, various films such as an organic EL material, etc. necessary for manufacturing an electro-optical panel (liquid crystal display device or organic EL panel). Moreover, it is being applied not only to these but widely industrial use.

  A number of inventions have been made so far for a method of obtaining a coating liquid film using this inkjet head (hereinafter also referred to as an inkjet coating method). For example, a plurality of inkjet heads are arranged in a direction perpendicular to the moving direction of the substrate, and a coating liquid film is obtained by discharging droplets discharged from the nozzle onto the substrate at a frequency corresponding to the moving speed of the substrate. The method is representative (see, for example, Patent Document 1). Since the ink jet coating method can arbitrarily determine the amount of droplets and the arrangement pitch on the substrate, the above-described classification of coating methods is a pre-metering coating method.

  However, there are problems in the coating method using the inkjet head. The above-mentioned problem is that in the shear mode type (piezo method) head in which the coating liquid is discharged as droplets from the nozzle by deformation of the flexible plate by the piezoelectric vibrator, that is, expansion and contraction of the channel (coating liquid pressure chamber), There is.

  When there is a large amount of air present in the coating solution, a difference in flow rate of the coating solution inside the channel occurs due to the expansion and contraction of the channel in the discharge process, and thereby a negative pressure is generated, resulting in saturated solubility in the coating solution. Decreases. As described above, when the saturation solubility in the coating solution decreases, the remaining air that cannot be dissolved grows into bubbles. It is known that when the bubbles accumulate inside the channel, discharge defects such as a decrease in discharge amount and nozzle clogging are caused.

  In order to prevent the discharge failure and stably discharge the coating solution, it is important to reduce the amount of air existing in the coating solution. Therefore, conventionally, a method of using a degassed coating solution has been taken in order to suppress fluctuations in the discharge amount. Examples of degassing of the coating solution include vacuum degassing and ultrasonic degassing. In this way, various degassing methods have been devised, and contrivances have been made to improve the discharge stability of the coating liquid from the inkjet head.

  In addition, the deaeration is effective even in a thermal type ink jet head that has a heating element and discharges the coating liquid from the nozzle due to a rapid volume change due to film boiling of the coating liquid caused by the heat energy from the heating element. It is known that there is. That is, by supplying the degassed coating liquid to the head, it is possible to reduce the air that causes the ejection failure from being sent to the head together with the coating liquid.

  In addition, the inkjet head raises the temperature of the head by discharging regardless of the method used to discharge the coating liquid. The increase in temperature causes fluctuations in the characteristics of the head and a decrease in the viscosity of the coating liquid, and as a result, the ejection characteristics change. Here, when the coating liquid passes through the head, the head is cooled as a result. That is, the coating liquid also has a role of keeping the temperature of the head within a certain range. Therefore, in order to keep the head temperature within a certain range in order to stabilize the ejection characteristics of the head, it is preferable to keep the temperature of the coating liquid at a predetermined temperature.

  Here, the predetermined temperature is a temperature within a certain range of the coating liquid that can maintain the temperature of the head within a certain range, and is set in advance by an experiment or the like.

  A degassing device that heats and degass the coating liquid (also referred to as ink) and cools the coating liquid after degassing by degassing using a gas permeable membrane to stabilize the degassing and ejection characteristics. Has been proposed (see, for example, Patent Documents 1 and 2).

In addition, when degassing using a gas permeable membrane and the space facing the ink through the gas permeable membrane is at a vacuum level equal to or lower than the saturated water vapor pressure of water, the amount of moisture per unit time permeated is a predetermined amount. The following deaeration devices have been proposed (see, for example, Patent Document 3).
JP 2006-75683 A Japanese Patent Laid-Open No. 2003-341083 JP-A-11-42771

  In Patent Documents 1 and 2, when degassing using a gas permeable membrane, the degassing efficiency is improved by heating and degassing the coating liquid, and the ejection of the head by cooling the degassed coating liquid. It stabilizes the characteristics.

  In Patent Document 2, when degassing using a gas permeable membrane, moisture, organic solvent, etc. in the coating liquid component escapes as vapor together with dissolved gas in the coating liquid in the degassing apparatus, and is applied in the degassing apparatus. The change in the concentration of the liquid is minimized.

  However, when the degassed coating liquid is fed to the head and filled, if there is residual air from the degassing device inside the liquid feeding pipe of the head, the residual air dissolves in the coating liquid and the degassed The remaining air of the coating liquid may increase again. As a result, the state in which the amount of air remaining in the coating solution is large immediately after the start of coating may cause a discharge failure. In Patent Documents 1 to 3, there is no mention of countermeasures against the residual air, and it has been difficult to reduce discharge failures caused by the residual air.

  The present invention has been made in view of the above situation, and can effectively remove the residual air in the liquid feeding pipe when the coating liquid is filled, and supply the sufficiently degassed coating liquid to the ink jet head. It is an object of the present invention to provide a coating method capable of stably coating by discharging droplets from the head.

The above object is achieved by the following method.
1. Using an inkjet head that ejects droplets of a coating liquid containing an organic solvent from a nozzle, the droplets are ejected from the inkjet head onto a continuously moving substrate, and the coating liquid is applied to form a coating liquid film. In the coating method to be formed, the step of degassing dissolved air existing in at least one of the organic solvents, the step of filling the organic solvent from which the dissolved air has been degassed into a liquid feed line of the coating solution, The coating liquid is deaerated in the space facing the coating liquid through a gas permeable membrane to deaerate the existing air existing in the coating liquid, and is fed to the liquid feeding line. Replacing the organic solvent filled in a line; and feeding the coating liquid continuously to the inkjet head while degassing;
The temperature of the side surface of the inkjet head is detected, and the droplet of the coating liquid is discharged from the inkjet head onto the substrate while controlling the temperature of the coating liquid to a predetermined temperature based on the detection result. And a step of forming a coating liquid film.
2. 2. The coating method according to 1, wherein the coating solution contains a plurality of organic solvents, and the composition ratio of the plurality of organic solvents does not change when the coating solution is degassed.
3. 3. The coating method according to 1 or 2, wherein the gas permeable membrane is made of a hollow fiber composed mainly of a fluororesin.
4). The coating method according to any one of claims 1 to 3, wherein the gas permeable membrane is made of a hollow fiber composed of polyethylene as a main component.

  As described above, when filling the coating liquid, after filling the liquid feeding tube with the degassed organic solvent, the liquid feeding pipe is filled with the degassed coating liquid using the gas permeable membrane, and droplet discharge is started. By doing so, it is possible to effectively remove the remaining air in the liquid feeding pipe while maintaining the state of the degassed coating liquid. Thereby, discharge failure can be reduced and stable application can be started.

  Further, by controlling the temperature of the degassed coating liquid to a predetermined temperature, the amount of air remaining in the coating liquid can be kept constant, and discharge defects such as a decrease in the discharge amount and nozzle clogging can be reduced. . Thereby, application | coating defects, such as a stripe at the time of application | coating, can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 is a schematic diagram showing an example of a coating apparatus to which the coating method according to the present invention can be applied.

  The long base material 12 wound in a roll shape is fed from the unwinding roll in the direction of arrow A by a driving means (not shown) and conveyed.

  The substrate 12 is conveyed while being supported by the backup roll 13. When the base material 12 passes the backup roll 13, the coating liquid is discharged onto the base material 12 from the inkjet head 2, and the coating liquid is applied to the base material 12 to form the coating liquid film 12a. The base material 12 coated with the coating liquid is wound around a winding roll (not shown) via a drying zone (not shown).

  In the present embodiment, the inkjet head 2 is arranged in the width direction of the base material 12 in the width direction of the base material 12 at an opposing position above the backup roll 13 with the base material 12 interposed therebetween. The coating liquid is ejected from the nozzles of the inkjet head 2 in the direction of the rotation center of the backup roll 13.

  The arrangement of the inkjet head 2 is not limited to the position shown in FIG. 1, and the inkjet head 2 can be arranged at a position not facing the backup roll 13, for example, a position before and after passing through the backup roll 13. In this case, in order to stably maintain the gap between the substrate 12 and the inkjet head 2, a support member that supports the substrate 12 is provided in the vicinity of the inkjet head 2 on the opposite side of the coating surface of the substrate 12. Is preferred.

  The coating apparatus includes an inkjet head 2 disposed in the width direction of the substrate 2 corresponding to the coating width, and a coating liquid supply mechanism 20 that supplies the coating liquid.

  A temperature sensor 14 that detects the temperature of the inkjet head 2 is disposed on the side surface of the inkjet head 2.

  The coating liquid supply mechanism 20 supplies the coating liquid to the inkjet head 2 and keeps the coating liquid pressure in the inkjet head 2 constant.

  The coating liquid supply mechanism 20 includes a coating liquid tank 7, an organic solvent tank 1, a liquid feeding pump 3, valves 4, 5, and 6 liquid feeding pipes 21a, 21b, and 21c. A deaeration device 8 for degassing the coating liquid is disposed between the liquid supply pipe 21a and the liquid supply pipe 21c. A heat exchanger 9 for exchanging heat with the coating solution is disposed in the vicinity of the inkjet head 2 in the middle of the liquid feeding pipe 21c via the liquid feeding pipe 21c. As the valves 4, 5 and 6, electrically driven electromagnetic valves or the like can be used.

  The coating liquid tank 7 stores the coating liquid and supplies the coating liquid to the inkjet head 2. In addition, it also has a mechanism (not shown) that keeps the coating solution pressure in the inkjet head 2 constant. The valve 5 controls the supply of the coating liquid.

  The organic solvent tank 1 stores at least one organic solvent contained in the coating solution, and supplies the organic solvent when the inkjet head is filled with the coating solution. The liquid feed pump 3 forcibly feeds the organic solvent to the inkjet head 2 and all liquid feed pipes during the filling. The valve 4 controls the feeding of the organic solvent. The valve 6 controls the feeding of the coating liquid and the organic solvent.

  The degassing device 8 sends the coating liquid while reducing the space facing the coating liquid to a pressure equal to or lower than the atmospheric pressure through the gas permeable membrane, and degass the coating liquid. The gas permeable membrane is preferably made of a material that is non-porous, has excellent gas permeability, and has chemical resistance to the coating solution. Specifically, as the material, a material mainly composed of fluororesin, polyethylene or the like is preferably used.

  Examples of the gas permeable membrane include a hollow fiber membrane made of a non-porous hollow fiber formed of the material. As the hollow fiber, those composed mainly of fluororesin or polyethylene are preferably used. The hollow fiber membrane may have a multilayer structure.

  FIG. 3 is a diagram showing an example of a deaeration device 9 using a hollow fiber membrane. The deaeration module 91 has a hollow fiber membrane 92 inside. As shown by the arrows in the figure, the coating liquid is sent into the deaeration module 91 from the liquid feeding pipe 21a, passes through the hollow fiber membrane 92, and is sent out to the liquid feeding pipe 21c. The space 93 facing the coating liquid through the hollow fiber membrane 92 is decompressed by the decompression pump VP.

  By the above, the gas which exists in a coating liquid can be reduced efficiently, suppressing the change of the composition of a coating liquid, a density | concentration, the structural ratio of the some organic solvent contained in a coating liquid, etc. to the minimum.

  The inkjet head 2 is not particularly limited. For example, a thermal type head that has a heating element and discharges the coating liquid from the nozzle by a rapid volume change due to film boiling of the coating liquid by the heat energy from the heating element may be used. A shear mode type (piezo type) head that has a vibration plate including a piezoelectric element in the ink pressure chamber and discharges the coating liquid by a pressure change of the ink pressure chamber by the vibration plate may be used.

  FIG. 2 shows an example of the inkjet head 201. FIG. 3 is a schematic perspective view in which a part of an example of the head is broken, and shows a case of a shear mode type (piezo type) ink jet head.

  The example shown in FIG. 1 uses a shear mode type (piezo type) ink jet head, and as shown in FIG. 1, a head control unit 30 for driving a piezoelectric substrate is connected to a connector (not shown). ) Is connected through. The head control unit 30 selects the operation intensity and frequency of the piezoelectric substrate when the coating liquid is ejected.

  The inkjet head 2 has a piezoelectric substrate 201b formed by joining an upper piezoelectric substrate 201b1 and a lower piezoelectric substrate 201b2, a top plate 201c, and a nozzle plate 201d.

  A plurality of nozzles 201b3 having a predetermined length parallel to each other are opened on the piezoelectric base plate 201b by opening the nozzle plate 201d and closed on the opposite side, and a flat surface connected to the closed side of the nozzle 201b3. A flat surface 201b4 and side walls 201b5 on both sides of a nozzle (ink pressure chamber) 201b3. The plurality of nozzles may be alternately used as a nozzle for a coating solution pressure chamber and a nozzle for an air pressure chamber. FIG. 2 shows a case where it is used for a coating solution pressure chamber. 201c2 shows the 1st top plate which covers the upper surface of the piezoelectric base | substrate 201b, 201c1 shows the 2nd top plate which covers the upper surface of a 1st top plate.

  Reference numeral 201e denotes a coating liquid supply pipe for the coating liquid. The coating liquid supplied from the coating liquid supply pipe 201e is discharged from the nozzle discharge port 201d1. Reference numeral 201c3 denotes a storage portion for the coating liquid supplied from the coating liquid supply pipe 201e, and is supplied to each nozzle 201b3 for each coating liquid pressure chamber from each coating liquid supply port 201c4 communicating with each nozzle 201b3. . Each nozzle 201b3 is covered with a first top plate 201c2 and a nozzle plate 201d, so that a plurality of sealed channels (coating liquid pressure chambers) are formed.

  Reference numeral 201d1 denotes a nozzle discharge port that discharges the coating liquid in the form of droplets due to a change in the pressure of the coating liquid pressure chamber accompanying shear deformation of each side wall. The interval between the nozzle discharge ports is preferably 0.02 to 0.3 mm. Reference numeral 201f denotes a pipe used for bleeding the coating liquid. 201f has a structure sealed by a valve or the like when the coating liquid is injected.

  The material of the first top plate and the second top plate is not particularly limited, and may be made of, for example, an organic material. However, alumina, aluminum nitride, zirconia, silicon, silicon nitride, silicon carbide, quartz, lead zirconate titanate ( PZT) and the like.

  A metal or resin is used as a base material constituting the nozzle plate 201d. For example, stainless steel, polyimide, polysulfone, polyethersulfone and the like can be preferably used. Particularly preferred is a polyimide resin, and DuPont: Kapton or Ube Industries, Ltd .: Upilex, etc. are preferred because they are excellent in dimensional stability, ink resistance, heat resistance and the like.

  Next, a procedure until the ink jet head 2 is filled with a coating solution and applied is described.

  First, using at least one organic solvent contained in the coating solution, the dissolved air existing in the organic solvent is degassed in advance. The degassing treatment can be performed using a degassing apparatus that can be used in a generally known organic solvent system.

  Next, the organic solvent tank 1 is filled with the degassed organic solvent. Further, with the valves 4, 5, 6 opened, the liquid feed pump 3 feeds the organic solvent to all the liquid feed pipes and the inkjet head 2 and fills them. Thereby, the residual air inside all the liquid feeding pipes and the inkjet head 2 can be forcibly excluded.

  Next, the coating liquid tank 7 is filled with the coating liquid, the valve 4 is closed, the valves 5 and 6 are opened, and ejection from the inkjet head 2 is started. Immediately after the start of discharge, since the above-mentioned organic solvent remains inside all the liquid feeding pipes and the inkjet head 2, the organic solvent is discharged continuously for a while to replace the coating liquid.

  The coating liquid is deaerated by the deaerator 8 and is fed and supplied to the inkjet head 2 via the liquid feeding pipe 21c.

  A temperature sensor 14 that detects the temperature of the inkjet head 2 is disposed on the side surface of the inkjet head 2 to detect the temperature of the inkjet head 2. Further, in the middle of the liquid feeding pipe 21c, a heat exchanger 9 is disposed in the vicinity of the coating liquid storage part 201c3 (see FIG. 2) of the inkjet head 2, and exchanges heat with the coating liquid via the liquid feeding pipe 21c. . The heat exchanger 9 can be an existing heat exchanger that is generally known.

  The temperature detection result of the temperature sensor 14 is sent to the temperature control unit 10, and the temperature control unit 10 controls the heat exchanger 9 based on the detection result to control the temperature of the coating liquid to a predetermined temperature. . In this way, maintaining the temperature of the coating liquid at a predetermined temperature means that the temperature of the inkjet head 2 is kept constant, and fluctuations in the characteristics of the head 2 due to the temperature rise of the inkjet head 2 and the coating liquid. It is possible to prevent a decrease in viscosity and to stabilize the discharge characteristics.

  As described above, when filling the coating liquid, after filling the liquid feeding tube with the degassed organic solvent, the liquid feeding pipe is filled with the degassed coating liquid using the gas permeable membrane, and droplet discharge is started. By doing so, it is possible to effectively remove the remaining air in the liquid feeding pipe while maintaining the state of the degassed coating liquid. Thereby, discharge failure can be reduced and stable application can be started.

Further, by controlling the temperature of the degassed coating liquid to a predetermined temperature, the amount of air remaining in the coating liquid can be kept constant, and discharge defects such as a decrease in the discharge amount and nozzle clogging can be reduced. . Thereby, application | coating defects, such as a stripe at the time of application | coating, can be reduced.
<Example>
Using the coating apparatus shown in FIG. 1, coating was performed on the substrate under different coating conditions, and the formed coating liquid film was evaluated.
(Application conditions)
1. 1. Whether or not the coating liquid is deaerated in the deaerator. 2. Whether to control the coating solution temperature to a predetermined temperature Whether or not the degassed organic solvent is filled in the liquid feed line (application specifications)
Base material: Polyethylene terephthalate resin film Substrate transport speed: 10 m / min
Distance between head nozzle surface and substrate: 2 mm
Head specifications: Number of nozzles: 500, distance between nozzles: 100 μm, nozzle diameter: 40 μm
Discharge speed of coating liquid from the head: 5 m / s
Droplet discharge volume: 40 pl per droplet
Coating temperature: 24 ° C
(Evaluation methods)
The number of streaks generated in the formed coating liquid film was visually observed, measured, and evaluated.
Evaluation level A: 0 to 3 streaks ○: 4 to 10 streaks Δ: 11 to 20 streaks ×: 21 or more streaks [Example 1]
First, 80% of the organic solvent, ethylene glycol monobutyl ether acetate, and the solid content of the pigment and the dispersant were mixed in a ratio of 20% and stirred with a high speed mixer or the like until uniform, thereby producing a mill base. Next, the mill base was dispersed with a horizontal end mill for about 1 hour to obtain an organic solvent-based coating solution.

  Prior to the start of coating, the organic solvent tank 1 was filled with the degassed organic solvent based on the above-described procedure up to coating, and further filled in the liquid feeding line. Next, the coating solution tank 7 is filled with the coating solution, and discharge is started while the coating solution is degassed by the degassing device 8, and the organic solvent is discharged to replace the coating solution. Application was performed.

  As the deaeration device 8, an organic solvent chemical liquid deaeration module MHF398PFDE (manufactured by Mitsubishi Rayon Co., Ltd.) using a hollow fiber mainly composed of polyethylene as a gas permeable membrane was used. The pressure of the space facing the coating solution through the hollow fiber was set to 5.33 kPa, and the air contained in the coating solution was deaerated.

At the time of application, the application liquid discharged from the head 2 is discharged from the head 2 by the temperature sensor 14 and the temperature control unit 10 disposed on the side surface of the heat exchanger 9 and the head 2. The temperature was controlled so that the temperature was constant. As the heat exchanger 9, a titanium double tube coil type small heat exchanger TDC-220-16 (manufactured by Yamaichi Seisakusho) was used.
[Example 2]
Compared to Example 1, 60% of the organic solvent, ethylene glycol monobutyl ether acetate, 20% of the organic solvent, propylene glycol, and 20% of the solid content of the pigment and dispersant were mixed in a high speed mixer and the like. To produce a millbase. Next, the mill base is dispersed in a horizontal end mill for about 1 hour to form an organic solvent-based coating solution. Except this, it is according to Example 1.
[Comparative Example 1]
This is an example in which filling of the degassed organic solvent into the liquid feeding line is not performed with respect to Example 1. Except this, the procedure is the same as in Example 1.
[Comparative Example 2]
In Example 1, the application liquid temperature is not controlled to be a predetermined temperature. Except this, the procedure is the same as in Example 1.
[Comparative Example 3]
In this example, filling of the degassed organic solvent into the liquid feed line and control for keeping the coating solution temperature constant are not performed. Except this, the procedure is the same as in Example 1.
[Comparative Example 4]
In contrast to the first embodiment, the coating liquid is not deaerated by the deaerator. Except this, the procedure is the same as in Example 1.
[Comparative Example 5]
In this example, the coating solution is not degassed by the degassing device and the filling of the degassed organic solvent into the liquid feeding line is not performed. Except this, the procedure is the same as in Example 1.
[Comparative Example 6]
In contrast to the first embodiment, the degassing of the coating liquid in the degassing apparatus and the control for keeping the coating liquid temperature constant are not performed. Except this, the procedure is the same as in Example 1.
[Comparative Example 7]
This is an example in which none of the degassing of the coating liquid in the degassing apparatus, the constant control of the coating liquid temperature, and the filling of the degassed organic solvent into the liquid feeding line are performed with respect to the first embodiment. Except this, it is according to Example 1.

  The evaluation results are shown in Table 1.

  As shown in Table 1, the effect of the present invention was confirmed.

It is a schematic diagram which shows the example of the coating device using the coating method which concerns on this invention. It is a figure which shows an example of an inkjet head. It is a figure which shows the example of the deaeration apparatus using a hollow fiber membrane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic solvent tank 2 Inkjet head 3 Liquid feed pump 4, 5, 6 Valve 7 Coating liquid tank 8 Deaeration apparatus 9 Heat exchanger 91 Deaeration module 92 Hollow fiber membrane 10 Temperature control part 12 Base material 12a Coating liquid film 13 Backup Roll 14 Temperature sensor 20 Coating liquid supply mechanism 21a, 21b, 21c Liquid feeding pipe 30 Head controller VP Pressure reducing pump

Claims (4)

Using an inkjet head that ejects droplets of a coating liquid containing an organic solvent from a nozzle, the droplets are ejected from the inkjet head onto a continuously moving substrate, and the coating liquid is applied to form a coating liquid film. In the coating method to be formed,
Degassing dissolved air present in at least one of the organic solvents;
Filling the organic solvent from which the dissolved air has been degassed into a liquid feed line for a coating liquid;
By depressurizing the space facing the coating solution through the gas permeable membrane, the coating solution is degassed the existing air existing in the coating solution, and is sent to the feeding line, and the feeding solution is sent. Replacing the organic solvent filled in the liquid line;
Continuously feeding the coating liquid to the inkjet head while degassing;
The temperature of the side surface of the inkjet head is detected, and the droplet of the coating liquid is discharged from the inkjet head onto the substrate while controlling the temperature of the coating liquid to a predetermined temperature based on the detection result. Forming a coating liquid film;
A coating method characterized by comprising: The coating method according to claim 1, wherein the coating solution contains a plurality of organic solvents, and the composition ratio of the plurality of organic solvents does not change when the coating solution is degassed. The coating method according to claim 1, wherein the gas permeable membrane is made of a hollow fiber composed mainly of a fluororesin. The coating method according to any one of claims 1 to 3, wherein the gas permeable membrane is made of a hollow fiber mainly composed of polyethylene.

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