JP2007325993A - Functional material coating system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a functional material coating system and method, which have an excellent discharge stability, and enable a formation of a good function film without depending on a viscosity of an application liquid of a functional material. <P>SOLUTION: The application liquid 14 of the functional material is continuously pressurized and discharged in a liquid column form from a nozzle 121 of a discharge head 12. The application liquid 14 discharged in the liquid column form is atomized and applied to a coating workpiece 10. In this manner, since the application liquid 14 is discharged by the continuous pressurization, it becomes possible to discharge the application liquid 14 stably and to apply it to the coating workpiece 10 even if it is an application liquid having a high viscosity (for example, from the viscosity which is close to water: about 3 mPa s or less to the viscosity: about 300 mPa s). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a functional material coating liquid and a functional material coating method for coating a functional material such as an electronic material and an optical material on a desired object.

  Conventionally, an electrophotographic member such as a photosensitive drum mounted on a copying machine has been mainly performed by a DIP method. In this method, a considerably larger amount than that actually applied is required for performance management of the material, which is wasteful. In addition, since precise control of the dipping rate and drying rate is required, there was a high percentage of defective products due to variations due to environmental fluctuations.

  On the other hand, in recent years, studies on application of inkjet technology to industrial applications are actively conducted. Inkjet is widely used for color printing and photo printing at home, but examples of printing are not paper, but examples of using coating liquid as industrial material instead of ink have been announced.

  For example, Patent Documents 1 to 4 propose using such an ink jet technique to form a functional film such as a polymer film or a conductive film to manufacture an industrial product such as an electrophotographic member. .

Japanese Patent Laid-Open No. 11-19554 JP 2001-88306 A US Pat. No. 6,245,745 JP 2004-248272 A

  However, in the above proposal, since the functional film is applied by a so-called drop-on-deman type discharge method in which droplets are directly discharged from a nozzle by intermittently applying a discharge pressure, the coating liquid has a high viscosity. In this case, the present situation is that stable discharge performance cannot be obtained.

  On the other hand, there are various functional material coating liquids that form functional films, ranging from low viscosity to high viscosity, which do not depend on the viscosity of the coating liquid, stably maintain discharge performance, and have good functional films. Is required to be formed.

  Therefore, in view of the above-mentioned conventional problems, the present invention is not dependent on the viscosity of the functional material coating solution, and has excellent ejection stability and a functional material coating apparatus capable of forming a good functional film, and functionality. It is an object to provide a material application method.

The above problem is solved by the following means. That is,
The functional material coating apparatus of the present invention is
A functional material application device for applying a functional material to an object to be coated,
A plurality of nozzles that discharge the coating liquid, and a coating liquid discharge head having a coating liquid chamber that communicates in common with each nozzle;
Pressurizing means for continuously pressurizing and supplying the coating liquid to the coating liquid chamber, and discharging the coating liquid in a liquid column shape from the nozzle;
Droplet forming means for forming the coating liquid discharged from the nozzle in a liquid column shape into droplets;
It is characterized by having.

  In the functional material coating apparatus of the present invention, the functional material coating liquid is continuously pressurized, the liquid columnar coating liquid is ejected from the nozzle, and the ejected liquid columnar coating liquid is made into liquid droplets. Apply to the coating. In this way, since the coating liquid is discharged under continuous pressure, the coating liquid can be stably discharged and applied to the object to be coated even with a high viscosity coating liquid.

  In the functional material coating apparatus of the present invention, it is preferable that the droplet forming unit is a vibration applying unit that applies vibration to the coating solution supplied to the coating solution chamber.

  In this case, the vibration applying means is arranged to apply vibration to the coating liquid from a direction orthogonal to the discharge direction of the coating liquid, and absorbs the vibration applied by the vibration applying means. The vibration absorbing means may further include a vibration absorbing means disposed to face the vibration applying means.

  The functional material coating apparatus of the present invention may further include a viscosity detecting means for detecting the viscosity of the coating liquid.

  In this case, it may further include a pressurization control unit that changes the pressurization of the coating liquid by the pressurization unit in accordance with the viscosity detected by the viscosity detection unit. Moreover, it can also have a droplet formation control means for changing a droplet formation condition to the coating liquid by the droplet formation means in accordance with the viscosity detected by the viscosity detection means.

  The functional material coating apparatus of the present invention may further include droplet interval detection means for detecting the interval between the droplets of the coating liquid.

  In this case, the apparatus may further include a pressurization control unit that changes the pressurization of the coating liquid by the pressurizing unit according to the droplet interval of the coating liquid detected by the droplet interval detecting unit. it can. In addition, the apparatus further includes droplet formation control means for changing the droplet formation condition of the coating liquid by the droplet forming means in accordance with the droplet interval of the coating liquid detected by the droplet interval detection means. Can do. Moreover, it can have a viscosity control means which changes the viscosity of the coating liquid according to the droplet interval of the coating liquid detected by the droplet interval detecting means.

  In the functional material coating apparatus of the present invention, a plurality of the functional material ejection heads can be provided. In this case, a different coating liquid can be discharged for each of the plurality of functional material discharge heads.

  In the functional material coating apparatus of the present invention, the recording material ejection head may have a width equal to or greater than a coating area width of the object to be coated.

On the other hand, the functional material application method of the present invention is:
A functional material application method for applying a functional material to an object to be applied,
The coating liquid that has been continuously pressurized is ejected from a nozzle in a liquid column shape, and the liquid column-shaped coating solution is applied to the object to be coated while forming droplets.

  In the functional material coating method of the present invention, as described in the functional material coating apparatus of the present invention, since the coating liquid is discharged under continuous pressure, the coating liquid can be stably applied even with a high viscosity coating liquid. Can be discharged and applied to an object to be coated.

  According to the present invention, it is possible to provide a functional material coating apparatus and a functional material coating method that can form a good functional film that is excellent in ejection stability and does not depend on the viscosity of the coating liquid of the functional material. it can.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is provided to the member which has the substantially same function through all the drawings, and the overlapping description may be abbreviate | omitted.

(First embodiment)
FIG. 1 is a perspective view showing a functional material coating apparatus according to the first embodiment. FIG. 2 is a schematic configuration diagram illustrating the functional material coating apparatus according to the first embodiment. FIG. 3 is a block diagram showing an internal configuration of the functional material coating apparatus according to the first embodiment.

  As shown in FIGS. 1 to 3, the functional material coating apparatus according to the first embodiment includes a discharge head 12 for discharging a functional material coating liquid 14 to an object to be coated 10, and the discharge head 12. And a coating liquid tank 16 for storing the coating liquid 14 to be fed.

  A coating liquid supply pipe 18 is connected to one end of the ejection head 12, and a coating liquid discharge pipe 20 is connected to the other end. One end side of the coating liquid supply pipe 18 and the coating liquid discharge pipe 20 (side not connected to the ejection head 12) is connected to the coating liquid tank 16. In the coating liquid supply pipe 18, a liquid feeding pump 181 (pressurizing means: high pressure arterial pump for solvent: triple plunger pump) and liquid feeding pump 181 from the coating liquid tank side toward the discharge head 12. A damper 182 that suppresses pulsation of the coating liquid, a filter 183 that removes foreign substances and the like in the coating liquid, a liquid feeding electromagnetic valve 184 that starts and stops the feeding of the coating liquid 14 to the ejection head 12, and a coating that feeds the liquid. A liquid supply pressure sensor 185 for detecting the pressure of the liquid 14 is provided. On the other hand, a discharge electromagnetic valve 201 for starting / stopping discharge of the coating liquid 14 is disposed in the coating liquid discharge pipe 20.

  In addition, the functional material coating apparatus according to this embodiment is a continuous-type ejection apparatus that performs ejection while continuously applying pressure. However, in order to place the ejected liquid droplets at a desired position, the functional material coating apparatus is a liquid of the coating liquid 14. Charging / deflection control can also be performed on the droplet. However, in addition to reducing the cost of the entire apparatus, it is preferable not to use charging / deflection control when an oily liquid is used as the coating liquid 14. In addition, there are many oil-based liquids in the coating liquid of the functional material.

  The discharge solenoid valve 201 is normally always closed and is opened when the coating liquid 14 is circulated, mixed air bubbles are removed, and the like.

  The coating liquid tank 16 includes a tank thermistor 161 (temperature detecting means) for detecting the temperature of the stored coating liquid 14 and a tank heater 162 (heat generating means) for heating the stored coating liquid 14. And a viscosity sensor 163 that detects the viscosity of the stored coating liquid 14. In addition, a stirring device 164 is built in the coating liquid tank 16. In addition, a replenishment tank 166 is connected to the coating liquid tank 16 via a replenishment pipe, and a solvent can be replenished to the coating liquid tank 16 by a replenishment pump 167.

  The object to be coated 10 is composed of a cylindrical body, and both ends thereof are supported by a support body 101 so as to be rotatable. Further, the object to be coated 10 is connected so as to be rotatable by an object to be coated driving device 102, specifically, rotatably driven by a drive motor 102A via a belt 102B. Further, a drying heater 103 (firing heater) is disposed around the workpiece 10 in a non-contact manner.

  A liquid receiver 22 (discharged coating liquid recovery means) is provided so as to shield between the discharge head 12 and the object to be coated 10. As shown in FIG. 4A, the liquid receiver 22 is positioned so as to block between the ejection head 12 and the coating object 10 when the application to the coating object 10 is stopped (that is, during non-coating). As shown in FIG. 4B, the liquid receiving and driving device 221 is movably disposed so as to be positioned apart from the discharge head 12 and the object 10 during application. That is, the liquid receiver 22 starts and stops application to the workpiece 10 by its movement. The liquid receiver 22 is connected to the coating liquid tank 16 through a filter 223 by a discharge pipe 222. When the discharged coating liquid 14 is received, the liquid receiver 22 is discharged to the coating liquid tank 16.

  Here, FIG. 4 is a schematic diagram showing a coating start / stop mechanism according to the first embodiment. In FIG. 4, parts other than the discharge head, the object to be coated, and the liquid receiver are omitted.

  Note that the mechanism for starting and stopping the application is not limited to the method of driving the liquid receiver 22. For example, as shown in FIG. 5, a fan 224 (blower) is provided above the droplets of the application liquid 14. A system in which the wind pressure is applied to the droplets of the coating liquid 14 by the fan 224, the ejection direction of the droplets is changed, the coating is stopped so as to hit the liquid receiver 22, and the coating is started by releasing the wind pressure. But you can. Here, FIG. 5 is a schematic view showing another application start / stop mechanism according to the first embodiment. In FIG. 5, components other than the discharge head, the object to be coated, the liquid receiver, and the fan are omitted.

  In addition, an area sensor 24 (for example, a CCD sensor, a CMOS sensor, or the like) for detecting a distance between droplets of the coating liquid 14 formed into droplets is provided. The area sensor 24 is for calculating the inter-droplet distance of the coating liquid 14 formed into droplets based on the image data of the droplets of the coating liquid 14 obtained by the area sensor 24.

  These members are connected to the system control unit 26 (see FIG. 3). Further, the system control unit 26 includes an inter-droplet distance calculation unit 261, a pump control unit 262, a solenoid valve control unit 263, a piezoelectric element control unit 264, a heater control unit 265, a liquid receiving drive control unit 266, and an object drive. A control unit 267 and a stirring device drive control unit 268 are included. The system control unit 26 is also connected to a timer 28 and a memory 30.

  Hereinafter, the ejection head 12 will be described. Here, FIG. 6 is a perspective view showing the coating liquid discharge head according to the first embodiment. FIG. 7 is a cross-sectional view of the coating liquid discharge head according to the first embodiment.

As shown in FIGS. 6 to 7, the ejection head 12 is configured by a cylindrical body made of, for example, stainless steel or nickel alloy. The ejection head 12 includes a plurality of nozzles 121 (for example, a nozzle diameter of 25 μm) arranged in the longitudinal direction, a coating liquid chamber 122 that communicates in common with each nozzle 121, and nozzles via the coating liquid chamber 122. And a piezoelectric element 123 (for example, a PZT ceramic film, a polyvinylidene fluoride film (PVF ₂ film)) provided so as to be opposed to 121.

  Further, in the coating liquid chamber 122 of the ejection head 12, a head thermistor 124 (temperature detection means) for detecting the temperature of the fed coating liquid 14 and a heated coating liquid 14 are heated. And a head heater 125 (heat generating means).

  The ejection head 12 is moved back and forth in the longitudinal direction of the head by a nozzle interval arranged in the longitudinal direction of the head by a driving device (not shown) during application. Thereby, the coating liquid 14 can be apply | coated to the to-be-coated article 10 without the clearance gap for a nozzle space | interval arising. Of course, the workpiece 10 may be movable.

  Here, the piezoelectric element 123 applies predetermined vibrations to the coating liquid 14 sent to the coating liquid chamber 122 to form droplets of the coating liquid 14 discharged from the nozzle 121 in a liquid column shape. It is. Although not shown, the piezoelectric element 123 generates a vibration (sound wave) by applying a high frequency voltage from an electrode to a PZT ceramic film, for example, and transmits this vibration to the coating liquid 14 in the coating liquid chamber 122.

  The piezoelectric element 123 is provided facing the nozzle 121 and is amplified by an external device (not shown) from the same direction as the discharge direction of the coating liquid 14 and is output at a voltage of, for example, a peak-to-peak voltage (Vpp) of about 50V. Is supplied with vibration by a standing wave (mixed wave of traveling wave and reflected wave: that is, a mixed wave of irradiated traveling wave and reflected wave reflected on the nozzle surface) The coating liquid 14 discharged in the form of a liquid column is formed into droplets.

  Here, the discharge state of the coating liquid 14 having a viscosity of about 9 mPa · s is shown in FIGS. For example, when the coating liquid 14 is discharged from the discharge head 12 at 0.9 MPa by the liquid feeding pump 181 without driving the piezoelectric element 123, the liquid columnar coating liquid 14 is discharged as shown in FIG. Then, when vibration is applied to the coating liquid 14 by the piezoelectric element 123, the coating liquid 14 discharged in a liquid column shape is formed into droplets as shown in FIGS. 9 shows a case where a vibration of 90 kHz is applied to the coating liquid 14, and FIG. 10 shows a case where a vibration of 60 kHz is applied to the coating liquid 14. As shown in the figure, when the vibration of 90 kHz is applied to the coating liquid 14, the droplet diameter of the coating liquid is smaller than when the 60 kHz vibration is applied to the coating liquid 14, and the inter-droplet distance (droplet interval). Is narrower. However, since the pump pressure is constant, the injection amount per unit time is the same.

  As shown in FIG. 8, when the coating liquid is applied in a liquid column state without forming droplets, a disordered jet is formed at a position away from the ejection head 12, and thus the uniformity of the coating film cannot be ensured. Therefore, it is necessary to make the coating liquid 14 into droplets.

  Here, FIG. 8 is a schematic view showing a discharge state of the coating liquid 14 when no vibration is applied. FIG. 9 is a schematic diagram showing a discharge state of the coating liquid 14 when a vibration of 90 kHz is applied. FIG. 10 is a schematic diagram showing a discharge state of the coating liquid 14 when a vibration of 60 kHz is applied.

Note that the frequency of vibration imparted by the piezoelectric element when the coating liquid 14 is formed into droplets is determined by the correlation between the piezoelectric element vibration characteristics, the ejection head vibration characteristics, the coating liquid speed, the nozzle diameter, and the like. . For example, the fluid speed (discharge speed) of the coating liquid can be expressed by the relationship represented by the following formula.
Formula (1): Fluid velocity (μm / sec) = frequency (Hz) × particle interval (μm) (Velocity = fλ)
Also, according to “Rayleigh / Theory of Sound”, the most likely to form droplets (they are more likely to generate particles)
Formula (2): Particle spacing (μm) = 4.51 × Nozzle diameter (μm) (λ = 4.51 × d)
It is.
In addition, the volume of droplets (particles) into droplets is
Formula (3): Volume (μm ³ ) = Nozzle area (μm ² ) × Particle spacing (μm) (Volume = Aλ)
It becomes.

Here, for example, when the fluid speed of the coating liquid is 10 m / sec and the nozzle diameter is 25 μm, the preferred frequency is 88.7 kHz. The volume of the droplet is about 55 pl (pico liter) (55,000 μm ³ ). However, the frequency is not determined only from the viewpoint of droplet formation, and it is necessary to consider the vibration characteristics of the ejection head and the piezoelectric element. That is, it is necessary to adjust the voltage applied to the piezoelectric element by considering the resonance point based on the structure of the ejection head and the characteristics of the piezoelectric element. For example, in the present embodiment, a voltage having a peak-to-peak voltage (Vpp) of about 30 V is applied to the piezoelectric element.

  The pressure for discharging the coating liquid 14 having a viscosity of about 9 mPa · s at 10 m / sec is, for example, about 0.9 MPa. However, when discharging the coating liquid having a viscosity of about 3 mPa · s, for example, 0.3 MPa Experiments have shown that a degree of pressure is required. Therefore, in order to discharge a coating liquid having a viscosity of about 100 mPa · s, it is expected that a pressure of about 10 MPa, for example, is necessary. This is explained by the fact that the pressure applied to the coating liquid and the flow velocity have a linear relationship with the channel resistance as a coefficient. However, the above numerical values are examples.

  This is because the resistance value varies greatly depending on the shape of the nozzle. Examples of the nozzle machining method generally include a punch machining method, an electroforming (electroforming) machining method, an electric discharge machining method, and a laser machining method. Each processing method has its advantages and disadvantages, and it is not possible to determine which method is preferable in general. However, when compared with a constant nozzle diameter, the cross-sectional shape of the nozzle is large from the viewpoint of the flow resistance of the nozzle. Tape forming electroforming is preferable from the viewpoint of keeping the injection pressure as low as possible.

  The ejection head 12 is not limited to the above configuration, and as shown in FIG. 11, a piezoelectric element 123 (for example, a PZT ceramic film) disposed at one end in the longitudinal direction of the head and the other end in the longitudinal direction of the head. May be configured to include a vibration absorbing member 126 (for example, silicon rubber). Here, FIG. 11 is a cross-sectional view of another coating liquid discharge head according to the first embodiment.

  In this form, the vibration is transmitted to the coating liquid 14 in the coating liquid chamber 122 by the piston sandwiching the piezoelectric element 123. At this time, many vibrations orthogonal to the vibration traveling direction of the discharge head 12 (the coating liquid chamber 122) are transmitted. The vibration is transmitted to the liquid columnar coating liquid 14 discharged from the nozzle 121, and the liquid columnar coating liquid 14 is formed into droplets, thereby generating droplets of the coating liquid. That is, the piezoelectric element 123 imparts vibration to the coating liquid 14 from a direction orthogonal to the discharge direction of the coating liquid 14.

  On the other hand, as described above, the vibration absorbing member 126 is provided at the other longitudinal end of the ejection head 12, that is, so as to face the piezoelectric element 123, so that the propagating vibration is absorbed, and the vibration is in a traveling wave state. It does not generate a reflected wave and does not become a standing wave.

  By applying such a traveling wave vibration to the coating liquid 14, the droplet separation length of the coating liquid 14 is kept sufficiently uniform, and satellite particles are hardly generated. In addition, it can implement in detail according to Japanese Patent Publication No. 6-84072 as a method of making it a droplet by the vibration by such a traveling wave.

  Here, in the case of droplet formation by standing wave, it is suitable for forming a high-viscosity coating liquid. In the case of droplet formation by traveling wave, it is suitable for forming a low-viscosity coating liquid. Is preferred. In addition, in the case of droplet formation by traveling waves, the uniformity of droplet formation is rich compared to the case of droplet formation by standing waves. According to the coating liquid 14 to be used, it can also select suitably, and combining these is also effective.

  Hereinafter, the coating operation of the functional material coating apparatus according to the present embodiment will be described by the operation of the system control unit 26. Here, FIG. 12 is a follow diagram showing the operation of the system control unit of the functional material coating apparatus according to the first embodiment. Hereinafter, the timer 28 acquires the time.

  First, for example, when a user detects an application start signal from an interface (not shown), the liquid receiver 22 is driven by the liquid receiver drive control unit 266 to shut off the object to be coated 10 and the ejection head 12 in Step 500. In addition, the pump control unit 262 drives the liquid feeding pump 181 and the electromagnetic valve control unit 263 opens the liquid feeding electromagnetic valve 184. In addition, the piezoelectric element control unit 264 drives the piezoelectric element 123. As a result, the liquid columnar coating liquid 14 is discharged from the nozzle 121 and the liquid columnar coating liquid 14 is made into droplets.

  Next, in step 501, the temperature of the coating liquid 14 is detected from the head thermistor 124 and the tank thermistor 161, and it is determined whether or not the detected coating liquid temperature is equal to or higher than a predetermined temperature. If the coating liquid temperature is affirmed at a predetermined temperature or higher stored in the memory 30 in advance, the process proceeds to step 503. On the other hand, if no, the process proceeds to step 502, where the heater controller 265 drives the head heater 125 and the tank heater 162 for a predetermined time to heat the coating solution. At the same time, the stirring device drive control unit 268 drives the stirring device 164 for a predetermined time to stir the coating solution in the coating solution tank 16. Then, the process proceeds to step 501.

  Next, in step 503, the distance between droplets of the coating liquid formed into droplets is measured. Specifically, the inter-liquid distance can be measured, for example, as follows. For example, the image data of the droplet-shaped coating liquid discharged by the area sensor 24 is detected (acquired). The inter-droplet distance calculation unit 261 analyzes the image data signal and extracts the droplet line image data. Next, the droplet line image data is binarized, the signal level is determined, and the frequency is calculated. Then, the liquid-liquid distance is calculated (measured) according to the frequency by referring to the cycle-liquid distance conversion table stored in the memory 30 in advance.

  In step 504, it is determined whether or not the inter-liquid distance is equal to or greater than a predetermined value (for example, nozzle diameter 25 μm × 4.51 = 112.75 μm: see formula (2)). If it is affirmed that the predetermined value is exceeded, the process proceeds to step 510. On the other hand, if negative, the process proceeds to step 505.

  Next, in step 505, the coating solution viscosity is detected from the viscosity sensor 163, and if the detected coating solution viscosity is affirmed below a predetermined viscosity stored in the memory 30 in advance, the process proceeds to step 506. On the other hand, if negative, the process proceeds to step 509.

  In step 506, the pressure (pump pressure) of the coating liquid 14 by the liquid feeding pump 181 is detected from the liquid feeding pressure sensor 185, and it is determined whether or not the pressure is equal to or higher than a predetermined pressure. When this pump pressure is affirmed at a predetermined pressure (for example, set at 500 to 800 kPa so as to be a coating liquid flow rate of 2.3 ml / min) stored in the memory 30 in advance, the process proceeds to step 507. On the other hand, if negative, the process proceeds to step 508.

  In step 507, the piezoelectric element control unit 264 adjusts the vibration frequency applied from the piezoelectric element 123 so as to decrease by a predetermined value. Then, the process proceeds to step 504.

  In step 508, the pump control unit 262 adjusts the pump pressure of the liquid feeding pump 181 so as to increase by a predetermined value. Then, the process proceeds to step 504.

  In step 509, the pump controller 262 replenishes the coating liquid tank 16 with a predetermined amount by the replenishing pump 167, and the stirrer drive control unit 268 drives the stirrer 164 for a predetermined time. Stir the coating solution. Then, the process proceeds to step 504.

  On the other hand, in step 510, the object driving control unit 267 drives the object driving device 102 to rotate the object 10 (for example, the rotation speed of the object 10 is 1 rotation / 1 second (1 rps). )).

  Next, in step 511, the liquid receiver drive control unit 266 releases the blocking of the liquid receiver 22 between the object to be coated 10 and the ejection head 12, that is, the liquid receiver 22 is separated from the interval. Thereby, application | coating to the to-be-coated object 10 of the coating liquid 14 is started.

  Next, in step 512, it is determined whether or not the liquid receiver 22 is disconnected from the object to be coated 10 and the ejection head 12, that is, whether or not a predetermined time has elapsed from the start of application. When the predetermined time (that is, application time) stored in the memory 30 in advance has elapsed and the result is affirmed, the process proceeds to step 513. On the other hand, if negative, the process proceeds to step 512.

  Next, in step 513, the liquid receiver 22 is driven by the liquid receiver drive control unit 266 to shut off the object to be coated 10 and the ejection head 12. In addition, the pump control unit 262 stops driving the liquid feeding pump 181 and the electromagnetic valve control unit 263 closes the liquid feeding electromagnetic valve 184. Further, the driving of the piezoelectric element 123 is stopped by the piezoelectric element control unit 264. Thereby, application | coating is complete | finished.

  Next, in step 514, it is determined whether or not a predetermined time has elapsed since the end of step 513, that is, the end of application. When the predetermined time (that is, the coating film smoothing time) stored in the memory 30 in advance has elapsed and the result is affirmed, the process proceeds to step 515. On the other hand, if negative, the process proceeds to step 514.

  Here, when coating is started as described above, droplets of the coating liquid 14 are ejected from the ejection head 12 and the droplets are coated on the coating object 10 as shown in FIG. The Next, as shown in FIG. 13B, the film of the coating liquid 14 applied to the object to be coated is smoothed. Then, a coating film 141 of the coating solution 14 can be formed as shown in FIG. Here, FIG. 13 is a process diagram showing the formation process of the coating film by the functional coating apparatus according to the first embodiment.

  In addition, by continuing the rotation of the coating object for a predetermined time after the coating is completed, it is possible to prevent the coating film from dripping in addition to smoothing the coating film. The landing of the coating liquid 14 on the surface of the object to be coated 10 does not necessarily cover the entire surface, and there is a gap between the landed droplets. Also, the jet may have a slight bend due to nozzle processing accuracy. For this reason, after landing on the surface of the object 10 to be coated, the coating liquid 14 is present in a shape close to a hemisphere reflecting the shape of the droplet as the viscosity increases. For this reason, in order to form a uniform coating film, it is important to manage the time in the smoothing step by rotating the object to be coated after the coating is completed. Further, when the coating film is smoothed while rotating the object to be coated 10, the centrifugal force causes the coating liquid 14 to work in a direction to protect the convex shape with respect to the object to be coated 10. It is preferable to reduce it to such an extent that no one is caused. The coating liquid 14 spreads due to the affinity with the surface of the object 10 to be coated, and the coating film is flattened while attracting adjacent landing droplets with the rotation time of the object 10 to be coated.

  Next, in step 515, the heater controller 265 drives the drying heater 103 (firing heater) for a predetermined time. Thereby, the applied coating film is dried. Depending on the material type of the coating liquid 14, not only drying but also baking such as thermosetting is performed. At this time, in order to prevent drying unevenness (baking unevenness) of the coating film, it is preferable to increase the rotation speed of the object to be coated 10 by the object driving control unit 267. It is also possible to reduce the rotation speed.

  Next, in step 516, the object driving control unit 267 stops driving the object driving apparatus 102 and stops the object 10 to rotate.

  As described above, the application is completed. In this embodiment, coating and drying are performed at one place by installing the discharge head 12 and the drying heater. However, the object to be coated 10 is moved to the drying chamber by the slide mechanism while continuing to rotate. It is possible to divide the process and improve the processing capacity.

  In the functional material coating apparatus according to the present embodiment described above, the functional material coating liquid 14 is continuously pressurized to discharge the liquid columnar coating liquid 14 from the nozzle 121, and the discharged liquid columnar liquid crystal The coating liquid 14 is formed into droplets and applied to the article 10 to be coated. In this way, since the coating liquid 14 is discharged under continuous pressure, even a high-viscosity coating liquid (for example, a coating having a viscosity of about 3 mPa · s or less close to water to a coating having a viscosity of about 300 mPa · s) is stable. Then, the coating liquid 14 can be discharged and applied to the article 10 to be coated.

  further. Each detection means (sensor) and control unit can realize optimum discharge stability of the coating liquid.

(Second Embodiment)
FIG. 14 is a schematic side view showing a functional material coating apparatus according to the second embodiment. FIG. 15 is a schematic front view showing a functional material coating apparatus according to the second embodiment. However, in FIG.14 and FIG.15, structures other than a discharge head and a to-be-coated object are abbreviate | omitted and shown.

  As shown in FIGS. 14 and 15, the functional material coating apparatus according to the present embodiment can be moved in the longitudinal direction of the coating object 10 by a driving device (not shown), and can be moved from the coating area width of the coating object. This is also a mode in which a short and short ejection head 12 is provided.

  As shown in FIG. 16, the short ejection head 12 is, for example, a matrix type ejection head in which the nozzles 121 are arranged such that the arrangement of the grid-like nozzles 121 is inclined with respect to the head movement direction S. . Thus, if one row in the grid-like nozzle 121 array is inclined in the head movement direction, the nozzle width (nozzle trajectory interval when the nozzle moves) along the direction perpendicular to the head movement direction can be shortened. High density application is possible. As a result, it is possible to easily increase the manufacturing speed due to the cost reduction of the device manufacturing, which is industrially advantageous. Here, FIG. 16 is a schematic front view showing the ejection head according to the second embodiment.

  Since other than these are the same as those in the first embodiment, description thereof will be omitted.

  In the functional material coating apparatus according to the present embodiment described above, as in the first embodiment, the functional material coating liquid 14 is continuously pressurized, and the liquid columnar coating liquid 14 is discharged from the nozzle. The discharged liquid columnar coating liquid 14 is made into droplets and applied to the object 10 to be coated. As described above, since the coating liquid 14 is discharged by continuously applying pressure, the coating liquid 14 can be stably discharged and applied to the coating object 10 even with a high-viscosity coating liquid.

  Here, in the present embodiment, one form of the ejection head 12 has been described. However, the present invention is not limited to this, and a form in which two or more ejection heads 12 are disposed may be used. Specifically, for example, as shown in FIG. 17, there is a form in which two ejection heads 12 </ b> A and 12 </ b> B that eject coating liquids of different functional materials are disposed with the workpiece 10 interposed therebetween. Here, FIG. 17 is a schematic side view showing another coating apparatus according to the second embodiment. In FIG. 17, components other than the object to be coated 10 and the ejection heads 12A and 12B are omitted.

  In the case of the form of FIG. 17, as shown in FIG. 18A, when a droplet of the coating liquid 14 </ b> A is ejected from the ejection head 12 </ b> A, the droplet is applied onto the object to be coated 10. Next, as shown in FIG. 18B, a coating film of the coating liquid 14A is formed. Next, as shown in FIG. 18C, when the droplet of the coating liquid 14B is ejected from the ejection head 12B onto the coating film of the coating liquid 14A applied to the coating object, the droplet Is applied on the film of the coating liquid 14A of the article 10 to be coated. And as shown in FIG.18 (D), it apply | coats so that coating liquid 14A, 14B may be laminated | stacked, and what laminated | stacked the coating film of the functional material which consists of a different material is obtained. Here, FIG. 18 is a process diagram showing another forming process of the coating film by the functional coating apparatus according to the second embodiment. In addition, 141A shows the coating film of the functional material by the coating liquid 14A, and 141B shows the coating film of the functional material by the coating liquid 14B.

  If this method is used, the coating liquid 14A and the coating liquid B can be simultaneously applied, planarized, and dried and fired, and a plurality of layers can be applied before drying.

  Here, in the other embodiment, the coating liquid 14B is applied in a coating amount that is, for example, twice that of the coating liquid 14A. For this purpose, for example, the moving speed of the ejection head 12B is discharged. The moving speed is half that of the moving speed of the head 12A. The same can be done by halving the rotation speed of the article 10 to be coated. In this case, the discharge conditions of the discharge head 12B are set such that, for example, the discharge speed (pump pressure) of the coating liquid 14 is doubled and the drive frequency of the piezoelectric element 123 is doubled with respect to the discharge conditions of the discharge head 12. Although it is possible to double the coating amount, it is generally not preferable to increase the pump pressure to increase the discharge speed because of problems with the pump performance and pressure resistance of the liquid circulation system.

  On the other hand, although not shown, when the coating liquid 14B is applied at a coating amount that is, for example, ½ times that of the coating liquid 14A, the moving speeds of the discharge head 12A and the discharge head 12B are both the same, and the discharge conditions of the discharge head 12B are set. For example, the discharge speed (pump pressure) of the coating liquid 14 is preferably halved and the drive frequency of the piezoelectric element 123 is preferably halved with respect to the discharge conditions of the discharge head 12. In this case, it is possible to set the moving speed of the discharge head 12B to twice the moving speed of the discharge head 12A, or to set the rotation speed of the object 10 to be doubled. Since the distance between the 14 landing droplets increases, it is not preferable for flattening the obtained coating film.

  That is, the increase in the coating amount is performed by the rotation speed (moving speed) of the object to be coated 10 and the movement speed of the ejection head 12 are decreased. It is preferable.

  In another form, as shown in FIG. 19A, when a droplet of the coating liquid 14A is ejected from the ejection head 12A to a predetermined area of the coating object, the droplet is covered. It is applied onto a predetermined area of the applied object 10. Next, as shown in FIG. 19B, droplets of the coating liquid 14B are ejected from the ejection head 12B to a predetermined area of the object to be coated (area other than the area of the coating liquid 14 by the ejection head 12). When it comes, the droplet is applied onto a predetermined area of the object to be coated 10. Then, as shown in FIG. 19C, coating liquids 14A and 14B are respectively applied to predetermined regions, and a functional material film made of a different material is patterned. Here, FIG. 19 is a process diagram showing another formation process of the coating film by the functional coating apparatus according to the second embodiment.

  When this method is used, for example, a film in which different functional material films are patterned as shown in FIGS.

  As described above, the functional material coating apparatus according to any of the embodiments is a continuous coating apparatus that discharges while continuously pressurizing the coating liquid, but intermittently ejects droplets of the coating liquid by a so-called piezoelectric element. Compared to a drop-on-demand (DOD) type coating device, the continuous type sprays constantly, so drying at the nozzle is not a problem. This is one of the reasons why the continuous type is suitable as the functional material coating apparatus. Functional materials often use organic solvents in the coating solution state, and are often highly volatile. With the DOD type, clogging occurs immediately after a pause, etc., and device stability is obtained. I can't.

  Another point that the continuous type coating apparatus is superior to the DOD type coating apparatus is that it can easily cope with liquids having high viscosity and different viscosities. That is, in piezoelectric vibration or rapid boiling (Thermal Ink Jet) used for the DOD type, the liquid viscosity is approximately 10 mPa · s, and it is difficult to eject a high-viscosity liquid higher than that. However, in the case of the continuous type, since discharge of the coating liquid depends on the pump pressure, there is basically no restriction on viscosity by selecting a suitable pump.

  Moreover, in the film formation of a functional material, it is fully conceivable that a plurality of materials are applied. In the DOD type coating device, it is necessary to optimally design the flow path structure centered on a piezo or a heater according to the viscosity of the jet liquid. In the case of a continuous type coating device, if the pump pressure is adjusted, the different viscosity It is possible to discharge the coating liquid without changing the configuration of the discharge head or the like. Therefore, the device design is simple and the degree of freedom in selecting the functional liquid is extremely high. This is also a major reason why the continuous type is suitable.

  In any of the embodiments, the form in which the piezoelectric element is applied as the coating liquid droplet forming means has been described. Alternatively, a method of forming droplets using electrostatic attraction may be used. Moreover, although the case of the cylindrical body (drum) was demonstrated as a to-be-coated object, of course, the thing of other shapes including a plate-shaped body is also applicable.

  In addition, the functional material coating apparatus according to the present embodiment includes electrophotographic members (electrophotographic photoreceptors, functional belts (intermediate transfer bodies), transfer rolls, charging rolls, etc.), and other industrial products (for example, liquid crystal Display, plasma display, semiconductor product).

It is a perspective view which shows the functional material application apparatus which concerns on 1st Embodiment. It is a schematic block diagram which shows the functional material coating device which concerns on 1st Embodiment. It is a block diagram which shows the internal structure of the functional material coating device which concerns on 1st Embodiment. It is a schematic diagram which shows the application | coating start / stop mechanism which concerns on 1st Embodiment. It is a schematic diagram which shows the other application start / stop mechanism concerning 1st Embodiment. It is a perspective view which shows the coating liquid discharge head which concerns on 1st Embodiment. It is sectional drawing of the coating liquid discharge head which concerns on 1st Embodiment. It is a schematic diagram which shows the discharge state of the coating liquid 14 when not giving a vibration. It is a schematic diagram which shows the discharge state of the coating liquid 14 when a 90 kHz vibration is provided. It is a schematic diagram which shows the discharge state of the coating liquid 14 when a 60 kHz vibration is provided. It is sectional drawing of the other coating liquid discharge head which concerns on 1st Embodiment. It is a follow figure showing operation of a system control part of a functional material application device concerning a 1st embodiment. FIG. 6 is a process diagram showing a process of forming a coating film by the functional coating apparatus according to the first embodiment. It is a schematic side view which shows the functional material coating device which concerns on 2nd Embodiment. It is a schematic front view which shows the functional material coating device which concerns on 2nd Embodiment. It is a schematic front view which shows the discharge head which concerns on 2nd Embodiment. It is a schematic side view which shows the other coating device which concerns on 2nd Embodiment. It is process drawing which shows the other formation process of the coating film by the functional coating device which concerns on 2nd Embodiment. It is process drawing which shows the other formation process of the coating film by the functional coating device which concerns on 2nd Embodiment. It is a schematic diagram which shows an example of the different functional material film | membrane patterned. It is a schematic diagram which shows an example of the different functional material film | membrane patterned. It is a schematic diagram which shows an example of the different functional material film | membrane patterned.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Coating object 101 Support body 102 Coating object drive apparatus 102A Drive motor 102B Belt 103 Drying heater 12 Discharge head 121 Nozzle 122 Coating liquid chamber 123 Piezoelectric element 124 Head thermistor 125 Head heater 126 Vibration absorbing member 14 Coating liquid 141 Coating film 16 Coating liquid tank 161 Tank thermistor 162 Tank heater 163 Viscosity sensor 164 Stirrer 166 Replenishing tank 167 Replenishing pump 18 Coating liquid supply pipe 181 Liquid feeding pump 182 Damper 183 Filter 184 Liquid feeding solenoid valve 185 Liquid pressure sensor 20 Coating liquid discharge pipe 201 Discharge solenoid valve 22 Liquid receiver 221 Liquid receiver driving device 222 Discharge pipe 223 Filter 224 Fan 24 Area sensor 26 System controller 261 Inter-droplet distance calculator 262 Pump controller 263 Electromagnetic valve control unit 264 Piezoelectric element control unit 265 Heater control unit 266 Liquid receiving drive control unit 267 Coating object drive control unit 268 Stirring device drive control unit 28 Timer 30 Memory

Claims (11)

A functional material application device for applying a functional material to an object to be coated,
A plurality of nozzles for discharging the coating liquid, a coating liquid discharging head having a coating liquid chamber that communicates in common with the nozzles, and continuously pressurizing and supplying the coating liquid to the coating liquid chamber; A pressurizing means for discharging the coating liquid into a liquid column,
Droplet forming means for forming the coating liquid discharged from the nozzle in a liquid column shape into droplets;
A functional material applicator characterized by comprising:   The functional material coating apparatus according to claim 1, wherein the droplet forming unit is a vibration applying unit that applies vibration to the coating liquid supplied to the coating liquid chamber.   The functional material coating liquid apparatus according to claim 1, further comprising a viscosity detection unit configured to detect the viscosity of the coating liquid. Viscosity detecting means for detecting the viscosity of the coating solution;
A pressure control means for changing the pressure applied to the coating liquid by the pressure means according to the viscosity detected by the viscosity detection means;
The functional material coating solution apparatus according to claim 1, further comprising: Viscosity detecting means for detecting the viscosity of the coating solution;
In accordance with the viscosity detected by the viscosity detection unit, a droplet formation control unit that changes a droplet formation condition to the coating liquid by the droplet formation unit;
The functional material coating apparatus according to claim 1, further comprising:   The functional material coating apparatus according to claim 1, further comprising a droplet interval detection unit that detects an interval between the droplets of the coating liquid. Droplet interval detecting means for detecting the interval between the coating liquids formed into droplets;
A pressurizing control unit that changes the pressurization of the coating liquid by the pressurizing unit according to the droplet interval of the coating liquid detected by the droplet interval detecting unit;
The functional material coating solution apparatus according to claim 1, further comprising: Droplet interval detecting means for detecting the interval between the coating liquids formed into droplets;
The apparatus further comprises droplet formation control means for changing a droplet formation condition of the coating liquid by the droplet forming means according to the droplet interval of the coating liquid detected by the droplet interval detection means. The functional material coating apparatus according to claim 1. Droplet interval detecting means for detecting the interval between the coating liquids formed into droplets;
Viscosity control means for changing the viscosity of the coating liquid in accordance with the droplet spacing of the coating liquid detected by the droplet spacing detecting means;
The functional material coating liquid apparatus according to claim 1, wherein   The functional material coating liquid apparatus according to claim 1, comprising a plurality of the functional material ejection heads. A functional material application method for applying a functional material to an object to be applied,
A functional material coating method, wherein the coating liquid that has been continuously pressurized is ejected from a nozzle in a liquid column shape, and the liquid column-shaped coating solution is applied to the object to be coated while forming droplets.

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