JP2013188663A - Intermittent coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermittent coating apparatus using an extrusion type die head, capable of accurately performing intermittent coating on a continuously traveling support.SOLUTION: This intermittent coating apparatus includes: a die head for discharging a coating fluid onto a support to form a paint film; a pump for pressure-sending the coating fluid to the die head; and a fluid supply path connecting the pump to the die head. The fluid supply path includes a relief path capable of discharging the coating fluid to the outside of the fluid supply path, and a fluid sending direction switching means capable of switching the fluid sending direction between a direction toward the die head and a direction toward the relief path. The die head includes an air vent port for discharging the inside air of a manifold within the die head. The intermittent coating apparatus further includes a vent path connecting the air vent port to a coating fluid pressure adjustment means.

Description

  The present invention relates to a coating technique using an extrusion die head, and more particularly to a coating apparatus capable of intermittently coating with high accuracy on a continuously running support.

  A coating device using an extrusion die head has the advantages of easy to obtain a highly accurate and uniform coating film, and less coating solution deterioration and contamination with foreign matter. Therefore, it is widely used in the manufacture of optical films and color filters for liquid crystal displays. It is used. Among them, the intermittent application technology that alternately forms the coating part and the intermittent part on the support by repeatedly discharging and stopping the coating liquid from the die for the continuously running support is the production of the lithium ion battery electrode. It is used for etc.

  FIG. 1 is a schematic diagram of a basic intermittent application apparatus 100 that forms a coating film 106 by pumping a coating liquid from a tank 101 to a die head 104 by a pump 102 and intermittently applying the coating liquid onto a support 105 from the tip of the die head 104. It is. In this apparatus, intermittent application is realized by providing a three-way valve 107 in the middle of the liquid supply path 103 connecting the pump 102 and the die head 104. That is, when applying the coating liquid from the die head 104, the coating liquid is sent to the die head 104. When the coating liquid is not discharged from the die head 104, the three-way valve 107 is switched to send the coating liquid to the relief path 108 to supply the tank 101. Return to.

  At this time, simply switching the three-way valve 107 in the direction of the relief path 108 takes time to reduce the pressure inside the die head 104, resulting in uneven film thickness at the coating finish of the coating film 106, or stretched like a beard. In some cases, the accuracy of intermittent application may deteriorate, for example, the coating liquid may be tailed at intermittent portions on the support 105. In order to solve this problem, a suck back valve 109 is installed in the liquid supply path 103 between the three-way valve 107 and the die head, and the pressure inside the die head 104 is reduced by sucking a small amount of coating liquid in the liquid supply path 103 during the intermittent operation. A device has been devised to improve the linearity and film thickness uniformity of the coating finish portion of the coating film 106 by rapidly decreasing and instantaneously stopping the discharge of the coating liquid from the tip of the die head 104.

  However, in the case of the configuration of FIG. 1, the coating liquid sucked into the suck back valve 109 during the intermittent period is released into the liquid supply path 103 when the coating liquid discharge is resumed, so that the film thickness at the coating start portion of the coating film 106 is not sufficient. There is a problem that tends to be uniform. In order to solve this problem, for example, as shown in FIG. 2, liquid feeding direction switching means such as a three-way valve 210 is provided between the suck back valve 209 and the liquid supply path 203, and when sucking the suck back valve 209, Proposal of switching so that the connected liquid supply path 203 and the relief path 208 are connected when the suck back valve 209 is discharged (see Patent Document 1). In the configuration of FIG. 1, the coating liquid sucked by the suck back valve 109 is discharged at the time of application. There has been a proposal (Patent Document 2) for preventing the deterioration of the film thickness accuracy at the coating start part by absorbing the pressure fluctuation caused by this by another suck back valve or the like.

JP 2002-219400 A JP 2011-152509 A

  However, even if these devices and methods are used, the pressure inside the die head even if sucked with a suckback valve due to the compression effect of air remaining in the air replacement in the die head before the start of coating or bubbles mixed in the coating liquid Did not drop sufficiently rapidly, and the linearity and film thickness uniformity at the coating coating finish could not be improved sufficiently.

  This invention is made | formed in view of such a situation, and makes it a subject to provide the coating device using the extrusion type | mold die head which can apply | coat intermittently with high precision to the support body which carries out continuous driving | running | working.

  As a result of intensive studies to solve the above problems, the inventors of the present application have found that the above problems can be solved by using a coating apparatus shown below, and have completed the present invention.

That is, the invention described in claim 1 is a die head that discharges a coating liquid onto a support to form a coating film, a pump that pumps the coating liquid to the die head, and a liquid supply that connects the pump and the die head. A coating device comprising a path,
Furthermore, the liquid supply path includes a relief path that can discharge the coating liquid to the outside of the liquid supply path, and a liquid supply direction switching unit that can switch a liquid supply direction between a direction toward the die head and a direction toward the relief path,
Furthermore, the die head includes an air vent port for discharging air in the manifold inside the die head,
The intermittent application device further includes a vent path connecting the air vent port and the coating liquid pressure adjusting means.

In the invention according to claim 2, the vent path includes a discharge path capable of discharging the coating liquid outside the vent path and a vent liquid flow control means.
2. The vent liquid flow control unit according to claim 1, wherein when the liquid feeding direction switching unit feeds liquid in the die head direction, the vent liquid flow control unit blocks outflow and inflow from the air vent port. It is an intermittent application device.

Further, in the invention according to claim 3, the vent liquid flow control means opens the outflow from the air vent port substantially simultaneously with the liquid feed direction switching means switching the liquid feed direction to the relief path, The negative pressure generated by the coating liquid pressure adjusting means sucks the coating liquid in the manifold into the vent path,
The intermittent coating apparatus according to claim 2, wherein the coating liquid pressure adjusting means releases the coating liquid while the vent liquid flow control means blocks the inflow / outflow from the air vent port. is there.

  According to the coating apparatus of the present invention, it is possible to realize intermittent coating with excellent linearity and film thickness uniformity at the coating start and coating end portions.

  Therefore, the present invention has an effect that it is possible to provide a coating apparatus using an extrusion die head that can be intermittently applied with high accuracy to a continuously running support.

The figure explaining the structure of the conventional intermittent application apparatus. The figure explaining the structure of the conventional intermittent application apparatus by which the device which improves the film thickness uniformity of the coating start was made | formed. The figure explaining the structure of the coating device of Example 1 of this invention. The figure explaining the structure of the die head of Example 1 of this invention. The figure explaining the operation | movement timing of the valve | bulb 311 of the liquid feeding direction switching means 307 of the Example 1 of this invention, the vent liquid flow control means 310, and the coating liquid pressure adjustment means 309. FIG.

  Hereinafter, a preferred embodiment of a coating apparatus according to the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 3, the coating apparatus of the present invention includes a die head 304 that discharges a coating liquid onto a support 305 to form a coating film 306, a pump 302 that pumps the coating liquid to the die head 304, a pump 302, A liquid supply path 303 for connecting the die head 304 is provided.

  Further, the liquid supply path 303 includes a relief path 308 that can discharge the coating liquid to the outside of the liquid supply path, and a liquid supply direction switching unit 307 that can switch the liquid supply direction between the direction toward the die head 304 and the direction toward the relief path 308. Thus, intermittent application can be performed by switching between discharging and stopping of the coating liquid from the die head 304. As such a liquid feeding direction switching means 307, a combination of a three-way valve or a two-way valve can be used.

  Further, the die head 304 includes an air vent port 316 that discharges air in the manifold 315 inside the die head, and further includes a vent path 313 that connects the air vent port 316 and the coating liquid pressure adjusting means 309. By adopting such a configuration, the linearity and film thickness uniformity of the coating coating finish portion are improved by sucking back using the coating liquid pressure adjusting means 309, and at the same time, it is an important factor in the deterioration of the accuracy of intermittent coating. Air mixed in the manifold 315 can be discharged. The position where the air vent port 316 is installed is not particularly limited, but it is desirable to provide the air vent port 316 in a place where air mixed in the manifold 315 easily collects, for example, a place on the antigravity side during application.

  Furthermore, as shown in FIG. 3, the coating apparatus of the present invention may be provided with a discharge path 314 through which the vent path 313 can discharge the coating liquid outside the vent path and a vent liquid flow control means 310. When the means 307 is feeding in the direction of the die head 304 (at the time of application), the liquid feeding direction switching means 307 and the vent are arranged so that the vent liquid flow control means 310 blocks the outflow / inflow from the air vent port 316. It is desirable that the liquid flow control means 310 is interlocked. By setting it as such a structure, the coating liquid discharge flow rate at the time of application | coating can be stabilized, and a highly accurate coating film can be obtained.

  Furthermore, in the coating apparatus of the present invention, the vent liquid flow control means 310 opens the outflow from the air vent port 316 at substantially the same time as the liquid feeding direction switching means 307 switches the liquid feeding direction to the relief path 308, and the coating liquid is discharged. It is desirable to control to suck the coating liquid in the manifold 315 into the vent path 313 with the negative pressure generated by the pressure adjusting means 309. By setting it as such a structure, the improvement of the linearity and film thickness uniformity of the coating-film 306 application finish part by suck back can be made more accurate and effective.

Further, the coating liquid sucked by the coating liquid pressure adjusting means 309 is discharged to the vent path 313 while the vent liquid flow control means 310 is blocking the inflow / outflow from the air vent port 316, so that the application liquid can be recovered. It is possible to prevent an increase in film thickness at the start of coating.

  As the vent liquid flow control means 310 capable of such operation, in addition to the structure using the valve 311 and the check valve 312 as shown in FIG. it can.

  Examples of the present invention and comparative examples thereof will be described below. In addition, this invention is not limited by this Example.

<Example 1>
Example 1 is an example in which the coating apparatus according to the present invention is used for manufacturing a lithium ion battery electrode member.

  The coating liquid applied in Example 1 was composed of 55 parts by weight of graphite, 10 parts by weight of a styrene butadiene rubber dispersion (concentration: 5.0% by weight, solvent: water), and 25 aqueous carboxymethyl cellulose (concentration: 2.0% by weight). It is a battery electrode slurry prepared by adding 10 parts by weight of pure water and 10 parts by weight of pure water and stirring with a disper. The application width is 200 mm, the application part length (conveying direction) is 250 mm, and the intermittent part length is 50 mm.

  FIG. 3 shows the configuration of the intermittent coating apparatus 300 used in the first embodiment. The intermittent coating apparatus 300 includes a tank 301, a pump 302, a liquid supply path 303, and a die head 304, and the coating liquid discharged from the tip of the die head 304 continuously travels at a speed of 20 m / min. 220 mm, 10 μm thick copper foil) with a dry film thickness of 100 μm.

  The liquid supply path 303 is provided with a liquid supply direction switching means 307 (three-way valve), and the coating liquid fed to the pump 302 can be switched between the die head 304 direction and the relief path 308 direction.

  Further, the die head 304 is provided with an air vent port 316, and the air vent port 316 is connected to the coating liquid pressure adjusting means 309 (suck back valve) by a vent path 313.

  Further, the vent path 313 is provided with a vent liquid flow control means 310 including a valve 311 and a check valve 312, and the vent path 313 is connected to the discharge path 314 via the check valve 312.

  The structure of the die head used in Example 1 is shown in FIG. The die head 400 includes two main blocks 425, two side blocks 426, a liquid supply port 421, a liquid discharge port 422, and a shim 424, and an air vent port 416 is provided. A manifold 415 and a slit 423 having a circular cross section are formed inside the die head 400.

  Using the intermittent coating apparatus described above, the liquid feed direction switching means 307 (three-way valve), the valve 311 of the vent liquid flow control means 310 and the coating liquid pressure adjusting means 309 (suck back valve) are provided at the timing shown in FIG. Interlocking was performed in conjunction. The drainage port 422 was always closed with a valve (not shown) after the coating liquid was circulated inside the die head before the experiment was started and air replacement was performed.

As shown in FIG. 5, the coating liquid pressure adjusting unit 309 (suck back valve) starts suction before the liquid feeding direction switching unit 307 (three-way valve) is switched in the relief path 308 direction. Since the valve 311 is still closed, the coating liquid does not flow out from the air vent port 416, and the coating liquid does not flow back from the discharge path 314 due to the effect of the check valve 312. Pressure is generated. Thereafter, the valve 311 opens almost simultaneously with the switching of the liquid feeding direction switching means 307 (three-way valve) in the direction of the relief path 308, and is generated in the vent path 313 due to the suction of the coating liquid pressure adjusting means 309 (suck back valve). Due to the negative pressure, a small amount of coating liquid is sucked from the air vent port 416, and the pressure inside the manifold 415 decreases. Thereafter, after the valve 311 is closed again, the liquid feeding direction switching means 307 (three-way valve) is switched in the direction of the die head 304, and the application is resumed. The valve 311 is closed at the timing when the coating liquid sucked by the coating liquid pressure adjusting means 309 (suck back valve) is released, and the coating liquid is discharged to the discharge path 314 via the check valve 312. The discharge amount during application is not changed.

  When the obtained coating film was examined, defects such as tailing at the end of coating were not found, and the film thickness distribution in the transport direction of the coating part was measured at intervals of 1 mm. The range was within 10 μm.

<Comparative Example 1>
In this comparative example 1, the same intermittent application apparatus and material as in Example 1 were used, but the application of the coating liquid pressure adjusting means 309 (suck back valve) was not performed, and intermittent application was performed with the valve 311 always closed. went.

  When the obtained coating film was examined, a tailing defect of about 5 mm in length was observed at the end of coating.

  INDUSTRIAL APPLICABILITY The present invention can be used for manufacturing products that require high-precision intermittent application, such as lithium ion battery electrode members.

100, 200, 300 ... intermittent coating apparatuses 101, 201, 301 ... tanks 102, 202, 302 ... pumps 103, 203, 303 ... liquid supply paths 104, 204, 304 ... die heads 105, 205, 305 ... supports 106, 206 , 306 ... Coating films 107, 207, 307 ... Liquid feed direction switching means (three-way valve)
108, 208, 308 ... Relief path 109, 209, 309 ... Coating liquid pressure adjusting means (suck back valve)
210, 310 ... Vent liquid flow control means 311 ... Air vent valve 312 ... Check valve 313 ... Vent path 314 ... Discharge path 115, 215, 315, 415 ... Manifold 316, 416 ... Air vent port 400 ... Die head 421 ... Supply port 422 ... drainage port 423 ... slit 424 ... shim 425 ... main block 426 ... side block

Claims (3)

A coating apparatus comprising: a die head that discharges a coating liquid onto a support to form a coating film; a pump that pumps the coating liquid to the die head; and a liquid supply path that connects the pump and the die head. ,
Furthermore, the liquid supply path includes a relief path that can discharge the coating liquid to the outside of the liquid supply path, and a liquid supply direction switching unit that can switch a liquid supply direction between a direction toward the die head and a direction toward the relief path,
Furthermore, the die head includes an air vent port for discharging air in the manifold inside the die head,
Furthermore, the intermittent application apparatus characterized by including the vent path | route which connects the said air vent port and a coating liquid pressure adjustment means. The vent path includes a discharge path capable of discharging the coating liquid outside the vent path and a vent liquid flow control means,
2. The vent liquid flow control unit according to claim 1, wherein when the liquid feeding direction switching unit feeds liquid in the die head direction, the vent liquid flow control unit blocks outflow and inflow from the air vent port. Intermittent application device. The vent liquid flow control means opens the outflow from the air vent port substantially simultaneously with the liquid feed direction switching means switching the liquid feed direction to the relief path, and the negative pressure generated by the coating liquid pressure adjusting means. And sucking the coating liquid in the manifold into the vent path,
The intermittent coating apparatus according to claim 2, wherein the coating liquid pressure adjusting means discharges the coating liquid while the vent liquid flow control means blocks the inflow / outflow from the air vent port.

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