JP2015188776A - Double-sided coating apparatus, double-sided coating method, and coating film formation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided coating apparatus that can uniformly coat a base material with a coating liquid by stabilizing a distance between a nozzle and the base material, and to provide a double-sided coating method and a double-sided coating film formation system incorporating the double-sided coating apparatus.SOLUTION: A non-coated section is made independent of a transportation path of a base material by first pinch rollers 71, 71 and second pinch rollers 72, 72, tensile force acting on the base material 5 in the non-coated section is set to be lower than tensile force acting on the base material 5 in the non-coated section by a dancer roll 73. A coating liquid is discharged to the base material 5 turned easily movable due to sagging produced by low tension on both front and rear faces from the first coating nozzle 20 and the second coating nozzle 40, and a position of the base material 5 passing between the first coating nozzle 20 and the second coating nozzle 40 is adjusted by a balance of discharge pressures of both.

Description

  The present invention relates to a double-sided coating apparatus and a double-sided coating method for simultaneously applying a coating solution such as a chemical battery material on both sides of a base material, and a coating film forming system incorporating the double-sided coating apparatus.

  Conventionally, in the manufacture of a chemical battery such as a lithium ion battery, a substrate such as a metal foil is transported by a roll-to-roll method, and a coating solution is ejected onto the surface of the substrate by discharging an electrode material coating liquid. Form. Moreover, in order to make an electrode into a multilayer structure, a coating film is often formed on both front and back surfaces of a substrate, and a coating film is formed by discharging a coating solution of an electrode material on both surfaces of the substrate. It has been known. As such a double-sided coating device, first, the coating liquid is applied to one side of the base material, followed by a drying treatment, and then the coating liquid is applied to the other side of the base material, followed by a drying treatment again. There is something to do. Even with such a technique, it is possible to perform the coating treatment on both surfaces of the base material, but two drying furnaces are required for one line, which increases the overall length of the apparatus and increases the cost.

  For this reason, an apparatus has been developed in which a coating liquid is applied to both surfaces of a substrate before the drying treatment, and the drying treatment is collectively performed on both surfaces of the substrate. For example, in the double-sided coating apparatus disclosed in Patent Document 1, the coating liquid is applied to the surface of the base material while being supported by a backup roller, and then the coating liquid is also applied to the back surface of the base material. A drying process is performed later.

  Moreover, in the double-sided coating apparatus disclosed by patent document 2, the coating die (coating nozzle) is provided so that it may oppose the surface side and back surface across a base material, and for both coating The coating solution is simultaneously discharged from the die onto both the front and back surfaces of the substrate to perform simultaneous coating on both sides. In the double-sided coating apparatus as disclosed in Patent Documents 1 and 2, the coating liquid is applied to both the front and back surfaces of the base material to perform a drying process in a lump, so that one drying furnace is sufficient, Increased electrode productivity.

JP 2005-246194 A JP 2008-284528 A

  In the double-sided coating apparatus disclosed in Patent Document 1, for the coating on the front side of the base material, the base material is supported by the backup roller from the back side, so that the gap between the slit die and the base material is stably maintained. The coating liquid can be uniformly applied to the substrate surface. On the other hand, at the time of coating on the back surface side of the base material, the coating liquid applied on the front surface side has not yet been dried, so that the surface of the base material cannot be directly supported by the backup roller. Therefore, in the apparatus disclosed in Patent Document 1, by providing a mechanism for ejecting an airflow substantially parallel to the conveyance direction of the substrate on the downstream side of the slit die that performs coating on the back surface side, The gap between the slit die and the substrate is stabilized by increasing the tension of the substrate.

  On the other hand, in a double-side coating apparatus that disposes a coating die as disclosed in Patent Document 2 and discharges the coating liquid simultaneously from the front and back surfaces of the base material, a backup roller is not required, but the coating liquid The position of the base material tends to become unstable due to the discharge pressure. For this reason, in Patent Document 2, the substrate is held so that the distance between the coating die on the front surface side and the back surface side and the substrate is equal, and a tension roller is used to prevent the substrate from slacking. It has been proposed to apply tension.

  However, even if strong tension is applied to the base material as disclosed in Patent Document 2, there are inevitable error factors such as position accuracy when installing the coating die, precision of the roller, and habit of the base material. Therefore, it has been difficult to stably and evenly maintain the distance between the coating die on the front side and the back side and the base material. Since the distance between the coating die and the substrate greatly affects the film thickness of the coating film, if the distance is unstable, there arises a problem that the coating accuracy becomes non-uniform.

  The present invention has been made in view of the above problems, a double-sided coating apparatus and a double-sided coating method capable of uniformly coating a coating liquid by stabilizing the distance between a nozzle and a substrate, and It aims at providing the coating-film formation system incorporating the double-sided coating apparatus.

  In order to solve the above-mentioned problem, the invention of claim 1 is a double-sided coating apparatus that simultaneously applies a coating liquid to both sides of a base material, and the base material fed from the first roller is wound up by the second roller. A conveying mechanism that continuously conveys the substrate, a first nozzle that discharges a coating liquid onto the first surface of the substrate conveyed by the conveying mechanism, and the first nozzle and the substrate facing each other. A second nozzle that discharges the coating liquid to a position on the second surface of the substrate corresponding to a liquid deposition position at which the first nozzle deposits the coating liquid on the first surface; A first liquid feeding means for feeding the coating liquid to the nozzle; a second liquid feeding means for feeding the coating liquid to the second nozzle; and a first discharge pressure for discharging the coating liquid from the first nozzle. And the second nozzle according to the balance between the second discharge pressure for discharging the coating liquid from the second nozzle. It characterized in that it comprises a control means for controlling said first feeding means and said second feeding means so as substrate passes through the predetermined position between the.

  According to a second aspect of the present invention, in the double-side coating apparatus according to the first aspect of the invention, the control means sets the first discharge pressure and the second discharge pressure equal to each other, and the first nozzle and the first The first liquid feeding means and the second liquid feeding means are controlled so that the base material passes through the center between the two nozzles.

  Further, the invention of claim 3 is the double-sided coating apparatus according to claim 1 or claim 2, wherein the base material traveling between the first nozzle and the second nozzle is the first discharge pressure. It is further characterized by further comprising a tension relaxation mechanism that relaxes the tension acting on the substrate so that it can be moved to the predetermined position by balance with the second discharge pressure.

  According to a fourth aspect of the present invention, in the double-side coating apparatus according to the third aspect of the present invention, the tension relaxation mechanism includes a dancer roller that maintains a constant tension acting on the substrate.

  Further, the invention of claim 5 is the double-sided coating apparatus according to claim 1 or claim 2, wherein the first nozzle and the conveying path of the base material from the first roller to the second roller A tension relaxation mechanism for lowering the tension acting on the base material in the coating section where the coating liquid is applied from the second nozzle to be lower than the tension acting on the base material in the section excluding the coating section; It is characterized by.

  Further, the invention of claim 6 is the double-sided coating apparatus according to the invention of claim 5, wherein the tension relaxation mechanism includes a pair of upstream pinch rollers installed at an upstream end of the coating section, and the coating. A pair of downstream pinch rollers installed at the downstream end of the work section and a tension that is provided in the coating section and acts on the base material in the coating section is based on the section excluding the coating section. And a dancer roller that maintains a constant value lower than the tension acting on the material.

  The invention of claim 7 is the double-sided coating apparatus according to the invention of claim 5, wherein the tension relaxation mechanism includes a pair of upstream pinch rollers installed at an upstream end of the coating section, and the coating. A pair of downstream pinch rollers installed at the downstream end of the work section, a feed speed of the pair of upstream pinch rollers, and a feed speed of the pair of downstream pinch rollers are adjusted in the coating section. And draw control means for making the tension acting on the material lower than the tension acting on the substrate in the section excluding the coating section.

  The invention of claim 8 is the double-sided coating apparatus according to any one of claims 5 to 7, wherein the tension relaxation mechanism is configured to apply the tension acting on the substrate in the coating section. A base material that travels between one nozzle and the second nozzle has a value that can move to the predetermined position by a balance between the first discharge pressure and the second discharge pressure.

  The invention of claim 9 is a coating film forming system, which is formed on both surfaces of a substrate by the double-side coating apparatus according to any one of claims 1 to 8 and the double-side coating apparatus. And a drying section for drying the coating film of the coating liquid.

  Further, the invention of claim 10 is a double-sided coating method in which the coating liquid is simultaneously applied to both surfaces of the substrate, and the substrate is continuously wound by winding the substrate fed from the first roller with the second roller. Transporting process, a first coating process for discharging the coating liquid from the first nozzle to the first surface of the substrate to be transported, and the first nozzle depositing the coating liquid on the first surface. A second coating step of discharging the coating liquid from the second nozzle to the position of the second surface of the base material corresponding to the liquid landing position to be liquidized, and discharging the coating liquid from the first nozzle The substrate is allowed to pass through a predetermined position between the first nozzle and the second nozzle by a balance between a discharge pressure and a second discharge pressure for discharging the coating liquid from the second nozzle.

  The invention according to claim 11 is the double-sided coating method according to the invention of claim 10, wherein the first discharge pressure and the second discharge pressure are made equal to each other between the first nozzle and the second nozzle. The center of is passed through a substrate.

  The invention of claim 12 is the double-sided coating method according to claim 10 or claim 11, wherein the substrate that travels between the first nozzle and the second nozzle has the first discharge pressure. The tension acting on the base material is relaxed so that it can be moved to the predetermined position by balance with the second discharge pressure.

  Further, the invention of claim 13 is the double-side coating method according to claim 10 or claim 11, wherein the first nozzle and the conveying path of the base material from the first roller to the second roller The tension acting on the substrate in the coating section where the coating liquid is applied from the second nozzle is made lower than the tension acting on the substrate in the section excluding the coating section.

  Further, the invention of claim 14 is the double-sided coating method according to the invention of claim 13, wherein the tension acting on the substrate in the coating section travels between the first nozzle and the second nozzle. The base material has a value that can move to the predetermined position by a balance between the first discharge pressure and the second discharge pressure.

  According to the first to ninth aspects of the invention, the first nozzle and the second nozzle are balanced by a balance between the first discharge pressure for discharging the coating liquid from the first nozzle and the second discharge pressure for discharging the coating liquid from the second nozzle. Since the base material passes through a predetermined position between the second nozzle, the distance between the nozzle and the base material can be stabilized and the coating liquid can be applied uniformly.

  In particular, according to the second aspect of the present invention, the first discharge pressure and the second discharge pressure are equalized so that the base material passes through the center between the first nozzle and the second nozzle. The distance between the 1 nozzle and the base material and the distance between the second nozzle and the base material can be made uniform.

  In particular, according to the invention of claim 5, the tension acting on the base material in the coating section of the transport path of the base material is made lower than the tension acting on the base material in the section excluding the coating section. Therefore, the passage position of the base material between the first nozzle and the second nozzle can be easily adjusted by the balance between the first discharge pressure and the second discharge pressure.

  According to the tenth to fourteenth aspects of the present invention, the first discharge pressure for discharging the coating liquid from the first nozzle and the second discharge pressure for discharging the coating liquid from the second nozzle are applied to the substrate by the balance. Since the predetermined position between the 1 nozzle and the 2nd nozzle is passed, the distance of a nozzle and a base material can be stabilized and a coating liquid can be applied uniformly.

  In particular, according to the eleventh aspect of the invention, since the first discharge pressure and the second discharge pressure are equalized and the center between the first nozzle and the second nozzle is passed through the base material, The distance between the material and the distance between the second nozzle and the substrate can be made uniform.

  In particular, according to the invention of claim 13, the tension acting on the base material in the coating section in the transport path of the base material is made lower than the tension acting on the base material in the section excluding the coating section. Therefore, the passage position of the base material between the first nozzle and the second nozzle can be easily adjusted by the balance between the first discharge pressure and the second discharge pressure.

It is a figure which shows the whole structure of the coating-film formation system incorporating the double-sided coating apparatus which concerns on this invention. It is a figure which shows the structure of a 1st liquid feeding mechanism and a 2nd liquid feeding mechanism. It is a figure which shows the base-material conveyance by a 2nd pinch roller. It is a figure for demonstrating the tension relaxation of the base material by a tension relaxation mechanism. It is a figure which shows the example in case the deviation has arisen in the passage position of a base material. It is a figure which shows the example by which the passage position of a base material is prescribed | regulated by the balance of the discharge pressure from a 1st coating nozzle and a 2nd coating nozzle.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a coating film forming system 1 incorporating a double-side coating apparatus according to the present invention. In FIG. 1 and the subsequent drawings, the size and number of each part are exaggerated or simplified as necessary for easy understanding.

  The coating film forming system 1 applies a coating liquid containing an active material as an electrode material to both surfaces of a base material while continuously conveying a long metal foil as a base material by a roll-to-roll method. , An apparatus for producing an electrode of a lithium ion secondary battery by performing a drying treatment of the coating solution. The coating film forming system 1 is configured by including a drying unit 80 in the double-side coating apparatus 10. The coating film forming system 1 includes a control unit 90 that manages the entire system.

  The double-side coating apparatus 10 according to the present invention includes a first coating nozzle 20, a second coating nozzle 40, a tension relaxation mechanism 70, and a transport mechanism 60 as main elements. Further, the double-side coating apparatus 10 includes a first liquid feeding mechanism 30 that feeds the coating liquid to the first coating nozzle 20 and a second liquid feeding mechanism 50 that sends the coating liquid to the second coating nozzle 40. (FIG. 2). The control unit 90 also controls each mechanism unit of the double-side coating apparatus 10 and functions as a control unit of the double-side coating apparatus 10.

  The transport mechanism 60 includes a winding roller (first roller) 61, a winding roller (second roller) 62, and a plurality of auxiliary rollers 63. The long base material 5 is fed from the unwinding roller 61 and is taken up by the take-up roller 62 while being guided by the plurality of auxiliary rollers 63, thereby roll-to-roll in order of the double-side coating apparatus 10 and the drying unit 80. It is continuously conveyed by the method. Note that the number and arrangement position of the auxiliary rollers 63 are not limited to the example in FIG. 1 and can be increased or decreased as necessary. However, since the double-side coating apparatus 10 according to the present invention coats the coating liquid on the back surface of the substrate 5 as well, the second coating nozzle 40 and the drying unit 80 in which the coating liquid on the back surface side is not dried. The auxiliary roller 63 cannot be provided between the two.

  The 1st coating nozzle 20 and the 2nd coating nozzle 40 are arrange | positioned in the position which opposes on both sides of the base material 5 conveyed by the conveyance mechanism 60. FIG. In this embodiment, the 1st coating nozzle 20 is provided above the base material 5 conveyed along the substantially horizontal direction by the conveyance mechanism 60, and the 2nd coating nozzle 40 is provided below. The first coating nozzle 20 and the second coating nozzle 40 have the same configuration that is generally vertically symmetric. The first coating nozzle 20 and the second coating nozzle 40 are slit nozzles formed of, for example, stainless steel and provided with slit-like discharge ports 21 and 41 along the width direction of the substrate 5.

  The first coating nozzle 20 discharges the coating liquid onto the surface of the substrate 5 that is transported by the transport mechanism 60. The second coating nozzle 40 discharges the coating liquid onto the back surface of the base material 5 that is transported by the transport mechanism 60. The “surface” of the base material 5 is one surface (first surface) of the two surfaces of the base material 5, and the “back surface” is the other surface (second surface) on the opposite side. . That is, the front surface and the back surface of the base material 5 are notations for simply identifying both surfaces of the base material 5, and any specific surface is not limited to the front surface or the back surface.

  FIG. 2 is a diagram showing the configuration of the first liquid feeding mechanism 30 and the second liquid feeding mechanism 50. As shown in the figure, the first liquid feeding mechanism 30 and the second liquid feeding mechanism 50 have the same configuration. The first liquid feeding mechanism 30 includes a tank 31, a pump 32, a valve 33, pressure sensors 34 and 35, and a liquid feeding pipe 36.

  The tank 31 stores a solution containing an active material that is an electrode material of a lithium ion secondary battery as a coating solution. The tank 31 may be provided with a stirrer and an air pressurization unit. The stirrer agitates the coating liquid stored in the tank 31 to make the concentration distribution of the active material uniform. The air pressurization unit pressurizes the liquid surface of the coating liquid stored by sending high-pressure air into the gas phase portion in the tank 31.

  The liquid feeding pipe 36 connects the tank 31 and the first coating nozzle 20. The liquid feeding pipe 36 feeds the coating liquid stored in the tank 31 toward the first coating nozzle 20. As the liquid feeding pipe 36, a stainless steel pipe or a resin pipe can be used. A pump 32 and a valve 33 are inserted in the middle of the route of the liquid feeding pipe 36.

  The pump 32 pumps the electrode material coating liquid stored in the tank 31 toward the first coating nozzle 20. As the pump 32, for example, a rotary pump using a servo motor as a drive motor can be adopted. The valve 33 intermittently supplies the coating liquid to the first coating nozzle 20 by opening and closing the flow path of the liquid feeding pipe 36. When the valve 33 opens the flow path of the liquid feeding pipe 36, the coating liquid is discharged from the first coating nozzle 20, and when the valve 33 is closed, the discharge from the first coating nozzle 20 is stopped.

  The first coating nozzle 20 is provided above the substrate 5 that is transported by the transport mechanism 60. The first coating nozzle 20 is provided such that the discharge port 21 faces downward (that is, faces the base material 5). The first coating nozzle 20 includes a shim, a manifold, and the like for defining a flow path connected to the slit-shaped discharge port 21. The first coating nozzle 20 is provided with a mechanism for adjusting its position and posture (not shown). The discharge port 21 of the first coating nozzle 20 is communicatively connected to a liquid feed pipe 36 through a manifold. The coating liquid fed from the liquid feeding pipe 36 to the first coating nozzle 20 is discharged from the discharge port 21 onto the surface of the substrate 5.

  A pressure sensor 34 is connected to a downstream side of the liquid feeding pipe 36 from the pump 32 (side closer to the first coating nozzle 20). The pressure sensor 34 measures the liquid pressure in the liquid feeding pipe 36 and measures the liquid feeding pressure at which the pump 32 pumps the coating liquid to the first coating nozzle 20. Further, a pressure sensor 35 is attached to the first coating nozzle 20. The pressure sensor 35 measures the discharge pressure from the discharge port 21 of the first coating nozzle 20. The pressure sensors 34 and 35, the pump 32, and the valve 33 are electrically connected to the control unit 90. The measurement results of the pressure sensors 34 and 35 are transmitted to the control unit 90, and the control unit 90 controls the operation of the pump 32 and the valve 33 to define the discharge pressure from the first coating nozzle 20.

  Similarly, the second liquid feeding mechanism 50 includes a tank 51, a pump 52, a valve 53, pressure sensors 54 and 55, and a liquid feeding pipe 56. The tank 51 stores a solution of the same active material as the tank 31 as a coating liquid. The tank 51 may be provided with the same stirrer and air pressurizing unit as the tank 31.

  The liquid feeding pipe 56 connects the tank 51 and the second coating nozzle 40. The liquid feeding pipe 56 feeds the coating liquid stored in the tank 51 toward the second coating nozzle 40. A stainless steel pipe or a resin pipe can be used as the liquid feeding pipe 56. A pump 52 and a valve 53 are inserted in the middle of the route of the liquid feeding pipe 56.

  The pump 52 pumps the electrode material coating liquid stored in the tank 51 toward the second coating nozzle 40. As the pump 52, for example, a rotary pump using a servo motor as a drive motor can be adopted. The valve 53 intermittently supplies the coating liquid to the second coating nozzle 40 by opening and closing the flow path of the liquid feeding pipe 56. When the valve 53 opens the flow path of the liquid feeding pipe 56, the coating liquid is discharged from the second coating nozzle 40, and when the valve 53 is closed, the discharge from the second coating nozzle 40 is stopped.

  The second coating nozzle 40 is provided below the substrate 5 that is transported by the transport mechanism 60. The 2nd coating nozzle 40 is provided so that the discharge port 41 may face the upper side (namely, it opposes the base material 5). The second coating nozzle 40 includes a shim, a manifold, and the like for defining a flow path connected to the slit-like discharge port 41. The second coating nozzle 40 is provided with a mechanism for adjusting its position and posture (not shown). The discharge port 41 of the second coating nozzle 40 is connected to the liquid supply pipe 56 through a manifold. The coating liquid fed from the liquid feeding pipe 56 to the second coating nozzle 40 is discharged from the discharge port 41 to the back surface of the substrate 5.

  A pressure sensor 54 is connected to a downstream side of the liquid feeding pipe 56 from the pump 52 (side closer to the second coating nozzle 40). The pressure sensor 54 measures the liquid pressure in the liquid feeding pipe 56 and measures the liquid feeding pressure at which the pump 52 pumps the coating liquid to the second coating nozzle 40. Further, a pressure sensor 55 is attached to the second coating nozzle 40. The pressure sensor 55 measures the discharge pressure from the discharge port 41 of the second coating nozzle 40. The pressure sensors 54 and 55, the pump 52 and the valve 53 are electrically connected to the control unit 90. The measurement results of the pressure sensors 54 and 55 are transmitted to the control unit 90, and the control unit 90 controls the operation of the pump 52 and the valve 53 to regulate the discharge pressure from the second coating nozzle 40.

  Further, the first liquid feeding mechanism 30 and the second liquid feeding mechanism 50 may be provided with a reflux pipe for returning the coating liquid to the tanks 31 and 51 when the discharge is stopped. The reflux pipe is branched from the pumps 32 and 52 and the valves 33 and 53 in the liquid feed pipes 36 and 56 and connected to the tanks 31 and 51. When the supply of the coating liquid is stopped, when the valves 33 and 53 close the flow path of the liquid supply pipes 36 and 56 while the operation of the pumps 32 and 52 is continued, the coating liquid fed from the pumps 32 and 52 is It returns to the tanks 31 and 51 through the reflux pipe.

  Furthermore, a filter may be provided in the liquid feeding pipes 36 and 56. The filter is provided between the valves 33 and 53 and the first coating nozzle 20 and the second coating nozzle 40, for example, and removes foreign matters from the coating liquid flowing through the liquid feeding pipes 36 and 56.

  Returning to FIG. 1, the tension relaxation mechanism 70 includes a pair of first pinch rollers 71, 71, a pair of second pinch rollers 72, 72, and a dancer roller 73. The pair of first pinch rollers 71, 71 are upstream of the first coating nozzle 20 and the second coating nozzle 40 along the transport path of the base material 5 by the transport mechanism 60 (side closer to the unwinding roller 61). Is installed. The first pinch rollers 71 and 71 are cylindrical rollers, and at least the outer peripheral surface thereof is formed of a material (for example, rubber) having a high friction coefficient with respect to the base material 5. The roll gap (interval) between the pair of first pinch rollers 71 and 71 is set to a value smaller than the thickness of the substrate 5, and both may be in contact with each other. Therefore, when the base material 5 passes between the pair of first pinch rollers 71, 71, the base material 5 is sandwiched and sent out by the pair of first pinch rollers 71, 71 without slipping.

  Further, at least one of the pair of first pinch rollers 71 and 71 is connected to a drive motor (not shown). The drive motor rotates the first pinch rollers 71 and 71, whereby the base material 5 is fed out at a predetermined feed speed. The feed speed by the first pinch rollers 71 and 71 is controlled by the control unit 90.

  On the other hand, the pair of second pinch rollers 72, 72 are located downstream of the first coating nozzle 20 and the second coating nozzle 40 (closer to the winding roller 62) along the transport path of the base material 5 by the transport mechanism 60. Side). FIG. 3 is a diagram illustrating the conveyance of the base material by the second pinch rollers 72 and 72. Each second pinch roller 72 is configured by fixing a pair of disk-shaped rollers 72b and 72b to both ends of the rotation shaft 72a. The diameter of the rotating shaft 72a is smaller than the diameter of the rollers 72b and 72b. Similar to the first pinch rollers 71 and 71, the rollers 72 b and 72 b are formed of a material (for example, rubber) having at least an outer peripheral surface with respect to the base material 5. The length of the rotating shaft 72 a is approximately the same as the width of the base material 5. Therefore, as shown in FIG. 3, the rollers 72 b and 72 b come into contact with both edges in the width direction of the substrate 5.

  The roll gap between the pair of second pinch rollers 72, 72, that is, the distance between the roller 72 b of one second pinch roller 72 and the roller 72 b of the other second pinch roller 72 is set to a value smaller than the thickness of the substrate 5. They may be in contact with each other. Therefore, when the base material 5 passes between the pair of second pinch rollers 72 and 72, both edges in the width direction of the base material 5 are sandwiched and sent out by the rollers 72b and 72b. In the positions of the second pinch rollers 72, 72, a coating film of the coating liquid is formed on the front surface and the back surface of the base material 5, but as shown in FIG. Since 72 is sent across the non-coating regions on both edges in the width direction of the substrate 5, damage to the coating film can be prevented and contamination of the second pinch rollers 72 and 72 can also be prevented.

  Further, at least one of the pair of second pinch rollers 72 and 72 is connected to a drive motor (not shown). The drive motor rotates the second pinch rollers 72, 72, thereby feeding the base material 5 at a predetermined feed speed. The feed speed by the second pinch rollers 72 and 72 is controlled by the control unit 90.

  Returning to FIG. 1, the dancer roller 73 is disposed between the first pinch rollers 71 and 71 and the second pinch rollers 72 and 72. The dancer roller 73 is a roller that is provided between the first pinch rollers 71 and 71 and the auxiliary roller 63 and is movable in the vertical direction. That is, the dancer roller 73 does not have a rotating shaft fixed, and moves up and down by the tension acting on the substrate 5. In other words, since the dancer roller 73 is not restrained in the vertical direction, the dancer roller 73 always applies a constant tension to the base material 5 regardless of its height position. The tension applied to the base material 5 by the dancer roller 73 is defined by the mass of the dancer roller 73 itself. The dancer roller 73 may be provided with a weight or an air cylinder for adjusting the tension applied to the base material 5.

  FIG. 4 is a view for explaining tension relaxation of the base material 5 by the tension relaxation mechanism 70. The pair of first pinch rollers 71, 71 are provided on the upstream side of the first coating nozzle 20 and the second coating nozzle 40. Further, the pair of second pinch rollers 72, 72 are provided on the downstream side of the first coating nozzle 20 and the second coating nozzle 40. That is, the first coating nozzle 20 and the second coating nozzle 40 that apply the coating liquid to the substrate 5 are provided between the first pinch rollers 71 and 71 and the second pinch rollers 72 and 72. It has been.

  Of the conveying path of the substrate 5 from the unwinding roller 61 to the take-up roller 62, the first coating nozzle 20 and the second coating are between the first pinch rollers 71 and 71 and the second pinch rollers 72 and 72. A coating section in which the coating liquid is applied from the nozzle 40 to the substrate 5 is used. Therefore, a pair of 1st pinch rollers 71 and 71 will be installed in the most upstream end of a coating area. On the other hand, a pair of 2nd pinch rollers 72 and 72 will be installed in the most downstream end of a coating area.

  The unwinding roller 61 and the winding roller 62 define the tension acting on the substrate 5 in the entire conveyance path of the substrate 5 from the unwinding roller 61 to the winding roller 62. Typically, the take-up speed by the take-up roller 62 is set to be slightly higher than the feed speed by the take-out roller 61, whereby tension is applied to the substrate 5.

  In the present embodiment, the tension applied to the base material 5 by the unwinding roller 61 and the winding roller 62 is blocked by the pair of first pinch rollers 71, 71 and the pair of second pinch rollers 72, 72. That is, the first pinch rollers 71 and 71 and the second pinch rollers 72 and 72 sandwich the base material 5 and feed the base material 5 at a feed speed different from that of the unwinding roller 61 and the take-up roller 62. The tension acting on the substrate 5 in the section is made independent from the influence of the unwinding roller 61 and the winding roller 62.

  The tension acting on the substrate 5 in the coating section independent from the influence of the unwinding roller 61 and the winding roller 62 is defined to a constant value by the dancer roller 73. The tension acting on the substrate 5 upstream of the coating section (that is, upstream of the first pinch rollers 71 and 71) is determined by the feed speed of the unwind roller 61 and the feed speed of the first pinch rollers 71 and 71. It is prescribed by. The tension acting on the substrate 5 downstream of the coating section (that is, downstream of the second pinch rollers 72, 72) is determined by the feed speed of the second pinch rollers 72, 72 and the winding of the winding roller 62. Defined by speed. And in this embodiment, the tension | tensile_strength which acts on the base material 5 in a coating area is the non-coating area except the coating area (in the conveyance path | route of the base material 5, an upstream and a downstream rather than a coating area). It is set to be lower than the tension acting on the substrate 5 in the section). That is, the mass of the dancer roller 73 is set so that the tension acting on the substrate 5 in the coating section is lower than the tension acting on the substrate 5 in the non-coating section.

  Thus, the tension relaxation mechanism 70 uses the first pinch rollers 71 and 71 and the second pinch rollers 72 and 72 to apply the tension acting on the substrate 5 in the coating section from the influence of the unwinding roller 61 and the winding roller 62. While making it independent, the tension acting on the base material 5 in the coating section by the dancer roller 73 is made lower than the tension acting on the base material 5 in the non-coating section to relieve the tension of the base material 5 in the coating section. It is doing. In addition, if the coating section in which the tension acting on the base material 5 is low becomes excessively long, conveyance failure such as meandering of the base material 5 occurs, so that the pinch rollers 71 and 71 and the second pinch rollers 72 and 72 are installed. The spacing is preferably kept to the minimum necessary length. Moreover, it is preferable to attach the tension meter which measures the tension | tensile_strength which acts on the base material 5 of the coating area to the dancer roller 73 or the auxiliary roller 63 in the coating area.

  Returning to FIG. 1 again, the drying unit 80 performs the drying process of the coating film of the coating liquid formed on both surfaces of the substrate 5 by the first coating nozzle 20 and the second coating nozzle 40. The drying unit 80 performs the drying process by evaporating the solvent from the coating liquid by heating the base material 5 transported by the transport mechanism 60. The drying unit 80 includes, for example, a preheating unit that gradually raises the coating film of the coating liquid, a main drying unit that heats up the coating film to a predetermined temperature and performs main heating, and heats the coating film to a higher temperature. You may provide the annealing part which removes the distortion and residual stress in a film | membrane, the cooling part which cools the heated coating film, etc.

  The control unit 90 controls each operation mechanism provided in the coating film forming system 1 to advance the coating process on the base material 5. The configuration of the control unit 90 as hardware is the same as that of a general computer. That is, the control unit 90 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, control software, data, and the like. It is configured with a magnetic disk. The coating process in the coating film forming system 1 proceeds by the CPU of the control unit 90 executing a predetermined processing program.

  When the electrode is manufactured by the coating film forming system 1 having the above-described configuration, the first coating nozzle 20 and the second coating nozzle 40 are continuously transported by the transport mechanism 60 by roll-to-roll. Thus, the coating liquid is simultaneously applied to the front and back surfaces of the substrate 5. The base material 5 to be coated is a metal foil that functions as a current collector of a lithium ion secondary battery. When the positive electrode of the lithium ion secondary battery is manufactured by the coating film forming system 1, for example, an aluminum foil (Al) can be used as the base material 5. Moreover, when manufacturing a negative electrode with the coating-film formation system 1, copper foil (Cu) can be used as the base material 5, for example. The substrate 5 is a long sheet-like metal foil, and the width and thickness thereof are not particularly limited. For example, the width may be 600 mm to 700 mm and the thickness may be 10 μm to 20 μm.

  In the double-side coating apparatus 10, the first coating nozzle 20 and the second coating nozzle 40 are arranged so as to face each other with the base material 5 transported by the transport mechanism 60 interposed therebetween. The first coating nozzle 20 discharges the coating liquid from the discharge port 21 onto the surface of the substrate 5 that is transported in a substantially horizontal direction by the transport mechanism 60. The first coating nozzle 20 discharges the coating liquid from the upper side of the substrate 5. One second coating nozzle 40 discharges the coating liquid from the discharge port 41 to the back surface of the substrate 5 that is transported in a substantially horizontal direction by the transport mechanism 60. The second coating nozzle 40 discharges the coating liquid from the lower side of the substrate 5.

When the positive electrode is manufactured by the coating film forming system 1, as a positive electrode material coating liquid, for example, lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, carbon (C) as a conductive additive, binder A mixed liquid of polyvinylidene fluoride (PVDF) as a solvent and N-methyl-2-pyrrolidone (NMP) as a solvent is used. Instead of lithium cobaltate, lithium nickelate (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ), lithium iron phosphate (LiFePO ₄ ), or the like can be used as the positive electrode active material.

On the other hand, when the negative electrode is manufactured by the coating film forming system 1, as a negative electrode material coating liquid, for example, a mixed liquid of graphite (graphite) as a negative electrode active material, PVDF as a binder, and NMP as a solvent. Is used. Instead of graphite, hard carbon, lithium titanate (Li ₄ Ti ₅ O ₁₂ ), silicon alloy, tin alloy, or the like can be used as the negative electrode active material. In both the positive electrode material and the negative electrode material, styrene-butadiene rubber (SBR) or the like can be used as a binder instead of PVDF, and water (H ₂ O) or the like can be used as a solvent instead of NMP. be able to. Furthermore, when using SBR as a binder and water as a solvent, carboxymethylcellulose (CMC) can be used in combination as a thickener. The coating liquid for these positive electrode material and negative electrode material is a slurry in which solids (fine particles) are dispersed, the viscosity of which is 1 Pa · s (pascal second) or more, and generally has thixotropic properties.

  The same kind of coating liquid is applied to the front surface and the back surface of the substrate 5. For example, if a positive electrode material coating solution is applied to the surface of the substrate 5 from the first coating nozzle 20, the positive electrode material coating solution is applied to the back surface of the substrate 5 from the second coating nozzle 40. Apply. Further, if the negative electrode material coating liquid is applied from the first coating nozzle 20 to the surface of the base material 5, the negative electrode material coating liquid is also applied from the second coating nozzle 40 to the back surface of the base material 5. Apply.

  The double-sided coating apparatus 10 of this embodiment discharges a coating liquid simultaneously on both front and back surfaces of the base material 5, and the first coating nozzle 20 and the second coating nozzle 40 sandwich the base material 5. They are installed so as to face each other (strictly, the discharge port 21 and the discharge port 41 face each other). Therefore, the coating liquid is discharged from the second coating nozzle 40 to the position on the back surface of the substrate 5 corresponding to the liquid deposition position where the first coating nozzle 20 deposits the coating liquid on the surface of the substrate 5. . That is, the coating liquid is simultaneously discharged from the first coating nozzle 20 and the second coating nozzle 40 to the front and back of the same position of the substrate 5.

  In such a configuration, the position of the base material 5 passing between the first coating nozzle 20 and the second coating nozzle 40 tends to become unstable due to the coating liquid discharge pressure from both nozzles. For this reason, in the double-sided coating apparatus disclosed in Patent Document 2, a strong tension is applied to the base material by the tension roller so that the base material is not slackened.

  However, as described above, even if it is disclosed in Patent Document 2, there are inevitable error factors such as the positional accuracy at the time of installation of the coating die, the accuracy of the roller, and the habit of the base material. It has been practically difficult to keep the distance between the coating nozzles on the front surface side and the back surface side and the substrate stable and even. In particular, in recent years, single-micron order accuracy is required for the travel position of the base material between the coating nozzles on the front and back sides, and even if strong tension is applied to the base material by the tension roller, the required accuracy is reduced. It was difficult to be satisfied.

  And when strong tension | tensile_strength is provided to the base material, the following problems will arise if the passage position of a base material is biased to either the surface side or the back surface side coating nozzle. FIG. 5 is a diagram illustrating an example in the case where deviation occurs in the passage position of the base material 5. In the example of FIG. 5, the passing position of the substrate 5 between the first coating nozzle 20 and the second coating nozzle 40 is biased toward the second coating nozzle 40 on the back surface side. For ease of understanding, although the degree of bias is exaggerated in FIG. 5, such bias is inevitably caused by the above-described habit of the base material.

  If the substrate 5 is biased as shown in FIG. 5 and a strong tension is applied to the substrate 5, the bias is discharged from the first coating nozzle 20 and the second coating nozzle 40. It does not fluctuate easily with pressure. If the discharge pressure from the second coating nozzle 40 is significantly higher than the discharge pressure from the first coating nozzle 20, it is between the first coating nozzle 20 and the second coating nozzle 40. Although the base material 5 moves slightly upward to reduce the bias, the second material that acts on the base material 5 as the base material 5 moves upward and the distance between the second coating nozzle 40 and the base material 5 increases. The pressure from the coating nozzle 40 becomes small, and the deviation of the base material position cannot be completely eliminated. Further, when the discharge pressures of the first coating nozzle 20 and the second coating nozzle 40 are different from each other, the discharge amount of the coating liquid is also different. The problem that the film thickness of a coating film becomes non-uniform also arises.

  Therefore, in the double-side coating apparatus 10 of the present embodiment, the first pinch rollers 71 and 71 and the second pinch rollers 72 and 72 make the coating section independent from the conveyance path of the base material 5, and in the coating section. The tension acting on the substrate 5 is made lower than the tension acting on the substrate 5 in the non-coating section. The base material 5 is continuously conveyed by a roll-to-roll method along a predetermined conveyance path by being fed from the unwinding roller 61 and being wound by the winding roller 62 while being guided by the auxiliary roller 63. . The tension that acts on the substrate 5 in the entire conveyance path of the substrate 5 from the unwinding roller 61 to the take-up roller 62 is regulated by the feeding speed of the unwinding roller 61 and the winding of the winding roller 62. Speed. The first pinch rollers 71, 71 and the second pinch rollers 72, 72 sandwich the base material 5 and feed the base material 5 at a feed speed different from that of the unwinding roller 61 and the winding roller 62, thereby providing a coating section. The tension acting on the substrate 5 is made independent of the influence of the unwinding roller 61 and the winding roller 62.

  Then, the dancer roller 73 maintains the tension acting on the base material 5 in the coating section at a constant value lower than the tension acting on the base material 5 in the non-coating section. That is, the tension acting on the substrate 5 in the coating section is relaxed by the tension relaxation mechanism 70 as compared with the non-coating section, and the substrate 5 in the coating section is given some slack.

  When the tension acting on the base material 5 in the coating section is relatively low and the base material 5 is slightly slackened, the first coating nozzle 20 and the second coating nozzle 40 The position of the base material 5 passing between the discharge pressure (first discharge pressure) for discharging the coating liquid from the first coating nozzle 20 and the discharge pressure (first pressure) for discharging the coating liquid from the second coating nozzle 40. 2) and the pressure fluctuates relatively easily. For example, when the discharge pressure of the second coating nozzle 40 is larger than the discharge pressure of the first coating nozzle 20, the base material 5 that passes between the first coating nozzle 20 and the second coating nozzle 40 is used. The position is pushed up from below and moves up. Conversely, when the discharge pressure of the first coating nozzle 20 is made larger than the discharge pressure of the second coating nozzle 40, the base material 5 that passes between the first coating nozzle 20 and the second coating nozzle 40. The position of is pushed down from above and moves downward.

  Thus, in the double-sided coating apparatus 10 of this embodiment, the tension | tensile_strength which acts on the base material 5 in a coating area by the tension relaxation mechanism 70 is lower than the tension | tensile_strength which acts on the base material 5 in a non-coating area. However, the substrate 5 in the coating section is slightly slackened. Then, by giving a slight slack to the substrate 5 in the coating section, the first coating nozzle 20 is balanced by the balance between the discharge pressure from the first coating nozzle 20 and the discharge pressure from the second coating nozzle 40. It is possible to allow the base material 5 to pass through a predetermined position between the first coating nozzle 40 and the second coating nozzle 40.

  FIG. 6 is a diagram illustrating an example in which the passage position of the base material 5 is defined by the balance of discharge pressures from the first coating nozzle 20 and the second coating nozzle 40. In this embodiment, in a state where the tension acting on the base material 5 in the coating section is lower than the tension acting on the base material 5 in the non-coating section to give the base material 5 some slack, The first coating nozzle 20 and the second coating nozzle 40 are caused to discharge the coating liquid from the discharge port 21 and the discharge port 41, respectively, with equal discharge pressure. Specifically, the measurement value of the pressure sensor 35 that measures the discharge pressure of the first coating nozzle 20 and the measurement value of the pressure sensor 55 that measures the discharge pressure of the second coating nozzle 40 are equal. The control unit 90 controls the pump 32 and the pump 52 to discharge the coating liquid from the first coating nozzle 20 and the second coating nozzle 40.

  When the first coating nozzle 20 and the second coating nozzle 40 arranged so as to face each other with the base material 5 sandwiched therebetween are discharged to the base material 5 from above and below at the same discharge pressure, The coating solution is deposited at the same pressure on the front and back surfaces at the same position. When the coating liquid is discharged at a discharge pressure equal to the front surface and the back surface of the same position of the base material 5 in a state where a slight slack is given to the base material 5 in the coating section, as shown in FIG. The base material 5 passes through the center between the first coating nozzle 20 and the second coating nozzle 40 due to the balance of both discharge pressures. That is, the distance from the 1st coating nozzle 20 to the base material 5 and the distance from the 2nd coating nozzle 40 to the base material 5 become equal.

  As shown in FIG. 6, while discharging the coating liquid from above and below the substrate 5 that passes through the center between the first coating nozzle 20 and the second coating nozzle 40, the substrate 5 is moved by the transport mechanism 60. When conveyed as indicated by the arrow AR6, a coating film of the coating liquid is formed on the front surface and the back surface of the substrate 5. In the present embodiment, the first coating nozzle 20 and the second coating nozzle 40 perform continuous coating that continuously discharges the coating liquid onto the front and back surfaces of the substrate 5 being conveyed. In addition, since the pair of second pinch rollers 72 and 72 sandwich the non-coating region at both edges in the width direction of the base material 5 (see FIG. 3), the coating film formed on the front surface and the back surface of the base material 5 There is no contact with the second pinch rollers 72, 72.

  The substrate 5 coated with the coating liquid on both the front and back surfaces by the first coating nozzle 20 and the second coating nozzle 40 is conveyed to the drying unit 80, and the substrate 5 is heated to evaporate the solvent from the coating solution. Then, the coating film of the coating solution is dried. When the substrate 5 is unloaded from the drying unit 80, the coating film of the coating liquid is sufficiently dried. Then, the substrate 5 carried out from the drying unit 80 is taken up by the take-up roller 62.

  In the present embodiment, the first pinch rollers 71, 71 and the second pinch rollers 72, 72 make the coating section independent from the conveyance path of the base material 5, and the dancer roller 73 applies the base material 5 in the coating section. The acting tension is set lower than the tension acting on the substrate 5 in the non-coating section. That is, in the invention disclosed in Patent Document 2, a strong tension is applied to the base material in order to stabilize the position of the base material. However, in the present invention, the base material 5 in the coating section is intentionally reversed. It gives some slack. Then, the coating liquid is discharged from the first coating nozzle 20 and the second coating nozzle 40 to both the front and back surfaces of the base material 5 which has become loose and easily movable, and the balance between the discharge pressures of both is determined. The position of the base material 5 passing between the first coating nozzle 20 and the second coating nozzle 40 is adjusted. In particular, in this embodiment, the first coating nozzle is made equal by equalizing the discharge pressure for discharging the coating liquid from the first coating nozzle 20 and the discharge pressure for discharging the coating liquid from the second coating nozzle 40. The base material 5 passes through the center between 20 and the second coating nozzle 40.

  However, if the tension acting on the base material 5 is excessively lowered in the coating section and the base material 5 is loosened greatly, a conveyance failure of the base material 5 occurs in the coating section. It is necessary to reduce the tension acting on the base material 5 to such an extent that no poor conveyance occurs. In other words, the tension relaxation mechanism 70 causes the base material 5 that travels between the first coating nozzle 20 and the second coating nozzle 40 to discharge the tension acting on the base material 5 in the coating section from both sides. It is desirable to set the value so that it can move to a predetermined position required by the pressure balance.

  According to this embodiment, the tension acting on the substrate 5 in the coating section is intentionally lowered, and the first is applied by the balance of the discharge pressures of both the first coating nozzle 20 and the second coating nozzle 40. Since the base material 5 passes through a predetermined position between the first coating nozzle 20 and the second coating nozzle 40, the coating nozzles 20 and 40 rather than applying a strong tension to the base material 5. The distance between the substrate 5 and the substrate 5 can be stabilized, and the coating liquid can be applied uniformly.

  In this embodiment, since the passing position of the base material 5 is adjusted by the balance of the discharge pressures of both the first coating nozzle 20 and the second coating nozzle 40, the installation positions of the nozzles and rollers are strictly Accuracy is not required, and the adjustment can be simplified.

  While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the above embodiment, the tension acting on the base material 5 in the coating section is defined by the dancer roller 73, but instead, the tension acting on the base material 5 is adjusted by draw control. Anyway. Specifically, the control unit 90 adjusts the feed speed of the pair of first pinch rollers 71 and 71 and the feed speed of the pair of second pinch rollers 72 and 72 to act on the substrate 5 in the coating section. Is made lower than the tension acting on the substrate 5 in the non-coating section. The tension acting on the base material 5 on the upstream side of the coating section is defined by the feeding speed of the unwinding roller 61 and the feeding speeds of the first pinch rollers 71 and 71. On the other hand, the tension acting on the substrate 5 on the downstream side of the coating section is defined by the feeding speed of the second pinch rollers 72 and 72 and the winding speed of the winding roller 62. The control unit 90 controls the first pinch rollers 71 and 71 so that the tension acting on the substrate 5 in the coating section is lower than the tension acting on the substrate 5 on the upstream side and downstream side of the coating section. And the feed speeds of the second pinch rollers 72 and 72 are adjusted. Even if it does in this way, similarly to the said embodiment, the tension | tensile_strength which acts on the base material 5 in a coating area will be made low intentionally, and the discharge pressure of both the 1st coating nozzle 20 and the 2nd coating nozzle 40 will be carried out. By this balance, the base material 5 can pass through a predetermined position between the first coating nozzle 20 and the second coating nozzle 40. For this reason, rather than giving strong tension to the substrate 5, the distance between the coating nozzles 20, 40 and the substrate 5 can be stabilized and the coating solution can be applied uniformly.

  In the above embodiment, the first pinch rollers 71, 71 and the second pinch rollers 72, 72 separate the coating section from the conveyance path of the base material 5. When the total length of the conveyance path of the base material 5 leading to is sufficiently short (for example, the total length is 2 m or less), the coating section does not have to be divided. In this case, it can also be understood that the entire conveyance path of the base material 5 from the unwinding roller 61 to the winding roller 62 is the coating section. And like the said embodiment, both the 1st coating nozzle 20 and the 2nd coating nozzle 40 are set by setting low the tension | tensile_strength which acts on the base material 5 in the whole conveyance path | route by the dancer roller 73 or by draw control. The base material 5 can pass through a predetermined position between the first coating nozzle 20 and the second coating nozzle 40 by the balance of the discharge pressures. For this reason, rather than giving strong tension to the substrate 5, the distance between the coating nozzles 20, 40 and the substrate 5 can be stabilized and the coating solution can be applied uniformly. However, if the section in which the tension acting on the base material 5 is low is long, a transport failure such as meandering of the base material 5 occurs. Therefore, when the transport path of the base material 5 is long, the first embodiment as in the above embodiment. It is preferable to make the coating section independent by the pinch rollers 71 and 71 and the second pinch rollers 72 and 72.

  In the above embodiment, torque control may be performed. For example, it is possible to use a roller having a function of rotating the take-up roller 62 with a constant torque, and to define the torque of the conveying section from the second pinch rollers 72, 72 to the take-up roller 62. Similarly, the unwinding roller 61 is provided with a mechanism that rotates in the direction opposite to the conveying direction of the base material 5 and a clutch mechanism that slides at a constant torque. You may prescribe | regulate the torque of a conveyance area.

  Moreover, in the said embodiment, although it has set it as the structure which makes the winding roller 62 wind up directly via the auxiliary roller 63 after the drying process in the drying part 80, it is not limited to this. For example, a further auxiliary roller 63 is added in the conveyance path from the auxiliary roller 63 to the take-up roller 62, and a dancer roller is provided between the two auxiliary rollers 63, and the second pinch rollers 72, 72 take up. You may make it prescribe | regulate the torque of the conveyance area of the roller 62. FIG.

  In addition, the second pinch rollers 72 and 72 are provided in the non-coating regions at both edges in the width direction of the base material 5 instead of fixing a pair of disk-shaped rollers 72b and 72b to both ends of the rotating shaft 72a. You may make it comprise with the cantilever roller which contacts.

  Moreover, in the said embodiment, although continuous coating which discharges a coating liquid continuously to the base material 5 was performed, it replaces with this and it interrupts from the 1st coating nozzle 20 and the 2nd coating nozzle 40. Alternatively, intermittent coating for discharging the coating liquid may be performed.

  Moreover, the 1st coating nozzle 20 and the 2nd coating nozzle 40 are not limited to the slit nozzle which has the one slit-shaped discharge ports 21 and 41, and have a some slit. Alternatively, a nozzle that discharges the coating liquid from a substantially circular discharge port may be used.

  Moreover, in the said embodiment, although the 1st coating nozzle 20 and the 2nd coating nozzle 40 were provided in the upper and lower sides of the base material 5 and double-sided simultaneous coating was performed, the base material 5 is inclined and conveyed from a horizontal surface. On the other hand, two coating nozzles may be provided at positions facing each other with the base material 5 interposed therebetween to perform simultaneous double-side coating. For example, while the base material 5 is transported along the vertical direction, two coating nozzles may be provided along the horizontal direction with the base material 5 interposed therebetween to perform simultaneous double-side coating.

  In addition, the coating liquid to be coated using the technology according to the present invention is not limited to the electrode material of the lithium ion secondary battery, for example, a lithium ion capacitor or a solar cell material (electrode material, It may be a coating liquid for a sealing material or an insulating film or a protective film for an electronic material. Or you may make it use the technique which concerns on this invention to apply | coat the coating liquid of an antistatic coating material to a glass substrate. Furthermore, the technique according to the present invention may be used to apply a pigment or adhesive coating solution.

DESCRIPTION OF SYMBOLS 1 Coating film formation system 5 Base material 10 Double-side coating apparatus 20 1st coating nozzle 21, 41 Discharge port 30 1st liquid feeding mechanism 31, 51 Tank 32, 52 Pump 33, 53 Valve 34, 35, 54, 55 Pressure Sensor 40 Second coating nozzle 50 Second liquid feeding mechanism 60 Conveying mechanism 61 Unwinding roller 62 Winding roller 70 Tension relief mechanism 71 First pinch roller 72 Second pinch roller 73 Dancer roller 80 Drying unit 90 Control unit

Claims (14)

A double-sided coating device that simultaneously applies a coating solution to both sides of a substrate,
A transport mechanism for continuously transporting the base material by winding the base material fed from the first roller with the second roller;
A first nozzle that discharges the coating liquid onto the first surface of the substrate transported by the transport mechanism;
The first nozzle and the substrate are arranged to face each other, and the first nozzle is applied to the position of the second surface of the substrate corresponding to the liquid application position where the coating liquid is applied to the first surface. A second nozzle for discharging liquid;
First liquid feeding means for feeding a coating liquid to the first nozzle;
Second liquid feeding means for feeding a coating liquid to the second nozzle;
A predetermined position between the first nozzle and the second nozzle by a balance between a first discharge pressure for discharging the coating liquid from the first nozzle and a second discharge pressure for discharging the coating liquid from the second nozzle. Control means for controlling the first liquid feeding means and the second liquid feeding means so that the substrate passes through
A double-sided coating apparatus comprising: In the double-side coating apparatus according to claim 1,
The control means sets the first discharge pressure and the second discharge pressure equal to each other, and the first liquid feeding means and the first liquid feeding means so that the base passes through the center between the first nozzle and the second nozzle. The double-side coating apparatus characterized by controlling said 2nd liquid feeding means. In the double-side coating apparatus according to claim 1 or 2,
Reducing the tension acting on the base material so that the base material traveling between the first nozzle and the second nozzle can move to the predetermined position by the balance between the first discharge pressure and the second discharge pressure. A double-side coating apparatus, further comprising a tension relaxation mechanism. In the double-side coating apparatus according to claim 3,
The double-side coating apparatus, wherein the tension relaxation mechanism includes a dancer roller that maintains a constant tension acting on the substrate. In the double-side coating apparatus according to claim 1 or 2,
The tension acting on the substrate is applied in the coating section where the coating liquid is applied from the first nozzle and the second nozzle in the conveyance path of the substrate from the first roller to the second roller. A double-side coating apparatus, further comprising a tension relaxation mechanism that lowers the tension acting on the base material in a section excluding the processing section. In the double-side coating apparatus according to claim 5,
The tension relaxation mechanism is
A pair of upstream pinch rollers installed at the upstream end of the coating section;
A pair of downstream pinch rollers installed at the downstream end of the coating section;
A dancer roller that is provided in the coating section and maintains a constant value lower than the tension acting on the base material in the section excluding the coating section, the tension acting on the base material in the coating section;
A double-sided coating apparatus comprising: In the double-side coating apparatus according to claim 5,
The tension relaxation mechanism is
A pair of upstream pinch rollers installed at the upstream end of the coating section;
A pair of downstream pinch rollers installed at the downstream end of the coating section;
By adjusting the feed speed of the pair of upstream pinch rollers and the feed speed of the pair of downstream pinch rollers, the tension acting on the substrate in the coating section is applied to the substrate in the section excluding the coating section. Draw control means for lowering the acting tension;
A double-sided coating apparatus comprising: In the double-side coating apparatus according to any one of claims 5 to 7,
The tension relaxation mechanism is configured such that the base material traveling between the first nozzle and the second nozzle has a tension acting on the base material in the coating section between the first discharge pressure and the second discharge pressure. The double-side coating apparatus is characterized in that the value can be moved to the predetermined position by balance. A double-sided coating apparatus according to any one of claims 1 to 8,
A drying section for drying the coating film of the coating liquid formed on both surfaces of the substrate by the double-side coating apparatus;
A coating film forming system comprising: It is a double-sided coating method in which a coating solution is applied simultaneously to both sides of a substrate,
A conveying step of continuously conveying the substrate by winding the substrate fed from the first roller with the second roller;
A first coating step of discharging the coating liquid from the first nozzle onto the first surface of the substrate to be conveyed;
A second coating step of discharging the coating liquid from the second nozzle to the position of the second surface of the base material corresponding to the liquid deposition position at which the first nozzle deposits the coating liquid on the first surface;
With
A balance between the first discharge pressure for discharging the coating liquid from the first nozzle and the second discharge pressure for discharging the coating liquid from the second nozzle is between the first nozzle and the second nozzle on the substrate. A double-sided coating method characterized by passing through a predetermined position. In the double-sided coating method of Claim 10,
The double-side coating method, wherein the first discharge pressure and the second discharge pressure are made equal to pass the center between the first nozzle and the second nozzle through the substrate. In the double-sided coating method according to claim 10 or 11,
Reducing the tension acting on the base material so that the base material traveling between the first nozzle and the second nozzle can move to the predetermined position by the balance between the first discharge pressure and the second discharge pressure. A double-sided coating method characterized by: In the double-sided coating method according to claim 10 or 11,
The tension acting on the substrate is applied in the coating section where the coating liquid is applied from the first nozzle and the second nozzle in the conveyance path of the substrate from the first roller to the second roller. A double-sided coating method characterized by lowering the tension acting on the base material in the section excluding the work section. In the double-side coating method according to claim 13,
The base material traveling between the first nozzle and the second nozzle has a tension acting on the base material in the coating section, and is placed at the predetermined position by a balance between the first discharge pressure and the second discharge pressure. A double-sided coating method characterized in that the value can be moved up to.

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