JP2015062865A - Nozzle adjustment method, double-side coating device, and coating nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-side coating device which can adequately coat both surfaces of a base material respectively with a coating liquid, and provide a nozzle adjustment method and a coating nozzle used in the double-side coating device.SOLUTION: A coating device normally coats both surfaces simultaneously with an upper coating nozzle 10 and a lower coating nozzle 30. A coating liquid is discharged only from the upper coating nozzle 10 on a front surface of a base material 5 while contacting a lower coating reference surface 34 with a rear surface of the base material 5 in a first reference position opposite to a discharge port 13 of the upper coating nozzle 10. After drying a coating film of the coating liquid formed on the front surface of the base material 5, a coating state of the front surface is measured. Then, on the basis of the coating state, an interval of the upper coating nozzle 10 and the base material 5, and a discharge flow rate of the coating liquid from the upper coating nozzle 10 are adjusted. The rear surface of the base material 5 is coated with the coating liquid separately, and the coating state is measured. On the basis of it, the lower coating nozzle 30 is adjusted.

Description

  The present invention relates to a double-sided coating apparatus that coats a coating liquid such as a chemical battery material on both sides of a substrate, a coating nozzle used in the double-sided coating apparatus, and a nozzle adjustment method for the coating nozzle. .

  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 base material before performing the drying processing, and the drying processing is performed collectively on both surfaces of the base material (for example, Patent Document 1). In the double-sided coating apparatus disclosed in Patent Document 1, a coating liquid is applied to the surface of the base material while being supported by a backup roller, and subsequently dried after coating the coating liquid on the back surface of the base material. Process. In the double-side coating apparatus disclosed in Patent Document 1, since the base material is supported by a backup roller from the back side for coating on the front surface side of the base material, a gap between the slit die (coating nozzle) and the base material is set. It can maintain stably and can apply a coating liquid uniformly on the base-material surface. On the other hand, at the time of coating on the back side of the substrate, the coating liquid applied on the surface side has not yet been dried, so that the surface of the substrate cannot be directly supported by the backup roller.

  For this reason, 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, and sucking the substrate The gap between the slit die and the substrate is stabilized by increasing the tension of the substrate.

  In addition, an apparatus that provides a coating nozzle so as to face the front side and the back side across the base material and stably supports the base material by balancing the hydraulic pressure discharged from both coating nozzles has also been studied. ing. In these double-side coating apparatuses, the coating liquid is applied to both the front and back surfaces of the base material, and the drying process is performed collectively. Therefore, only one drying furnace is required, and the productivity of the electrode is increased.

JP 2005-246194 A

  In a conventional double-sided coating device, it is confirmed whether or not an appropriate coating process has been performed by measuring the weight per unit area of the coating film formed on the front and back surfaces of the substrate after the drying process. I was going. When the weight per unit area of the coating film is out of the appropriate range, the coating adjustment such as the gap between the coating nozzle and the substrate and the discharge flow rate has been performed.

  However, when the coating liquid is simultaneously applied to the front and back surfaces of the base material and batch drying is performed, it is difficult to individually measure the coating weights on the front and back surfaces of the base material. That is, the coating weight as the sum of the front and back surfaces of the substrate was to be measured. Then, even if the total coating weight on the front surface and the back surface of the substrate is within the proper range, there is a problem that the individual coating weights on the front surface and the back surface are out of the proper range. In such a case, the produced electrode is a defective product.

  The present invention has been made in view of the above problems, and is a double-sided coating apparatus and a nozzle adjustment method capable of appropriately coating a coating liquid on both sides of a substrate, and the double-sided coating apparatus. An object of the present invention is to provide a coating nozzle for use in the above.

  In order to solve the above problems, the invention of claim 1 is directed to a first coating nozzle for coating a coating liquid on a first surface of a substrate and a second coating nozzle for coating a coating liquid on a second surface. In the nozzle adjustment method for adjusting the substrate, a conveying step of continuously conveying the substrate by winding the substrate fed from the first roller with the second roller, and a first reference facing the first coating nozzle First test coating for discharging a coating liquid from the first coating nozzle to the first surface of the substrate while bringing the first coating reference surface into contact with the second surface of the substrate at a position A first measuring step of measuring a coating state of the first surface of the substrate, and a first adjusting step of adjusting the first coating nozzle based on a measurement result in the first measuring step, The second coating reference surface is brought into contact with the first surface of the substrate at a second reference position facing the second coating nozzle. Meanwhile, a second test coating step for discharging a coating liquid from the second coating nozzle onto the second surface of the substrate, and a second measurement for measuring the coating state of the second surface of the substrate. And a second adjustment step of adjusting the second coating nozzle based on a measurement result in the second measurement step.

  The invention of claim 2 is the nozzle adjustment method according to the invention of claim 1, in the first adjustment step, the distance between the first surface of the substrate and the first coating nozzle, and the first The discharge flow rate of the coating liquid from the coating nozzle is adjusted, and in the second adjustment step, the distance between the second surface of the substrate and the second coating nozzle and the coating from the second coating nozzle are applied. The discharge flow rate of the working fluid is adjusted.

  The invention according to claim 3 is the nozzle adjustment method according to claim 1 or claim 2, wherein the first coating reference surface is attached to the second coating nozzle, and the second coating reference surface is provided. Is attached to the first coating nozzle.

  The invention of claim 4 is a double-sided coating apparatus for applying a coating liquid to both surfaces of a substrate, and the substrate is continuously wound by winding the substrate fed from the first roller with the second roller. A transport mechanism that transports the first coating nozzle, a first coating nozzle that discharges a coating liquid onto the first surface of the base material, the first coating nozzle and the base material sandwiched therebetween, and the base material A second coating nozzle that discharges a coating liquid onto the second surface of the substrate, a first nozzle moving mechanism that moves the first coating nozzle relative to the first surface of the substrate, and the second coating. When adjusting the second nozzle moving mechanism for moving the nozzle relative to the second surface of the substrate and the first coating nozzle, at a first reference position facing the first coating nozzle When adjusting the first coating reference surface in contact with the second surface of the substrate and the second coating nozzle, the second coating nozzle Characterized in that it comprises a second coating reference surface in contact with the first surface of the substrate at a second reference position facing the Engineering nozzle, the.

  According to a fifth aspect of the present invention, in the double-side coating apparatus according to the fourth aspect of the invention, the first coating reference surface is attached to the second coating nozzle, and the second coating reference surface is the first coating surface. It is attached to one coating nozzle.

  Further, the invention of claim 6 is the double-sided coating apparatus according to the invention of claim 5, wherein the first coating reference surface is provided at a position closer to the substrate than the discharge port of the second coating nozzle. The second coating reference surface is provided at a position closer to the substrate than the discharge port of the first coating nozzle.

  The invention of claim 7 is a coating nozzle used when coating the coating liquid on both surfaces of the substrate, and discharge ports for discharging the coating liquid onto one surface of the substrate that is continuously conveyed And a coating reference surface that comes into contact with the one surface of the base material when the coating nozzle is adjusted on the other surface side of the base material.

  According to an eighth aspect of the present invention, in the coating nozzle according to the seventh aspect of the present invention, the coating reference surface is provided at a position closer to the substrate than the discharge port.

  According to the first to third aspects of the present invention, test coating is performed on each of the first surface and the second surface of the base material to measure the coating state, and the first coating nozzle and the second coating are measured based on the test coating. In order to individually adjust the coating nozzle, the first coating nozzle and the second coating nozzle can be appropriately adjusted by detecting the coating failure of the first surface and the second surface of the substrate individually, A coating liquid can be appropriately applied to each of both surfaces of the substrate.

  According to invention of Claim 4-6, when adjusting a 1st coating nozzle, the 1st which contacts the 2nd surface of a base material in the 1st reference position facing a 1st coating nozzle is 1st. A coating reference surface and a second coating reference surface that contacts the first surface of the substrate at a second reference position facing the second coating nozzle when adjusting the second coating nozzle; Therefore, the first coating nozzle and the second coating nozzle can be individually adjusted by applying the coating liquid on each of the first surface and the second surface of the base material under the same conditions as in normal processing. The coating liquid can be appropriately applied to each of both surfaces of the substrate.

  According to the invention of claim 7 and claim 8, when adjusting the coating nozzle on the other surface side of the base material, since the coating reference surface is brought into contact with the one surface of the base material, normal processing is performed. The coating liquid can be applied to both sides of the substrate under the same conditions as the time and the coating nozzle can be adjusted individually, and the coating solution can be applied appropriately to each side of the substrate. .

It is a figure showing the whole double-side coating device composition concerning the present invention. It is sectional drawing which shows the structure of an upper side coating nozzle and a lower side coating nozzle. It is a figure which shows typically the coating state of the surface of a base material, and a back surface. It is a figure which shows the state which is discharging the coating liquid from an upper side coating nozzle, making a lower side coating reference surface contact the back surface of a base material. It is a figure which shows the state which has discharged the coating liquid from the lower side coating nozzle, contacting the upper surface coating reference surface with the surface of a base material. It is sectional drawing which shows the other example of a structure of an upper side coating nozzle and a lower side 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 double-side coating apparatus 1 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.

  This double-side coating apparatus 1 applies a coating liquid containing an active material that is an electrode material on both sides of the base material while conveying a long metal foil as a base material by a roll-to-roll method. This is an apparatus for producing an electrode of a lithium ion secondary battery by performing a drying treatment of the coating solution. The double-side coating apparatus 1 includes an upper coating nozzle 10, a lower coating nozzle 30, a drying unit 50, a transport mechanism 60, and a measurement unit 70. The double-side coating apparatus 1 includes a control unit 90 that manages the entire apparatus.

  The base material 5 is a metal foil that functions as a current collector of a lithium ion secondary battery. When manufacturing the positive electrode of a lithium ion secondary battery with the double-side coating apparatus 1, aluminum foil (Al) can be used as the base material 5, for example. Moreover, when manufacturing a negative electrode with the double-side coating apparatus 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.

  The long base material 5 is fed from the unwinding roller (first roller) 61 and wound up by the winding roller (second roller) 62, so that the upper coating nozzle 10 and the lower coating nozzle 30 are moved. Then, it is continuously conveyed by the roll-to-roll method in the order of the drying unit 50 and the measurement unit 70. The transport mechanism 60 includes the unwinding roller 61 and the winding roller 62 and a plurality of guide rollers 63. Note that the number and arrangement position of the guide rollers 63 are not limited to the example of FIG. 1 and can be increased or decreased as necessary. However, since the double-side coating apparatus 1 according to the present invention coats the coating liquid on the back surface of the base material, the lower coating nozzle 30 and the drying unit 50 in which the coating liquid on the back surface side is not dried. The guide roller 63 cannot be provided between the two.

  The drying unit 50 performs a drying process of the coating film of the coating liquid formed on both surfaces of the substrate 5 by the upper coating nozzle 10 and the lower coating nozzle 30. The drying unit 50 heats the substrate 5 transported by the transport mechanism 60 to evaporate the solvent from the coating liquid and perform a drying process. The drying unit 50 includes, for example, a preheating unit that gradually raises the coating film of the coating liquid, a main drying unit that raises 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 measurement unit 70 includes a transmission sensor (not shown) using X-rays or β-rays. The transmission type sensor measures the transmission amount of X-rays or β rays radiated from one surface side of the substrate 5 on the other surface side. And a sensor measures the film thickness of the coating film currently formed in the front and back of the base material 5 after the drying process which passes the measurement part 70 from the attenuation factor.

  The control unit 90 controls each operation mechanism provided in the double-side coating apparatus 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. When the CPU of the control unit 90 executes a predetermined processing program, the coating process in the double-side coating apparatus 1 proceeds.

  FIG. 2 is a cross-sectional view showing the configuration of the upper coating nozzle 10 and the lower coating nozzle 30. In the present embodiment, the upper coating nozzle 10 is provided above the base material 5 that is transported along the substantially horizontal direction by the transport mechanism 60, and the lower coating nozzle 30 is provided below. The upper coating nozzle 10 and the lower coating nozzle 30 have the same configuration that is generally vertically symmetric. The upper coating nozzle 10 and the lower coating nozzle 30 are slit nozzles formed of, for example, stainless steel and provided with slit-like discharge ports along the width direction of the substrate 5.

  A manifold 11 and a flow path 12 are formed inside the upper coating nozzle 10. The upper end side of the flow path 12 communicates with the manifold 11, and the lower end side outlet is defined as a slit-like discharge port 13. A coating liquid is supplied to the manifold 11 from a coating liquid supply source (not shown). The supplied coating liquid is diffused in the manifold 11 in the longitudinal direction of the discharge port 13 (the width direction of the base material 5), and then flows through the flow path 12 to the discharge port 13 to be discharged. 13 is discharged toward the surface of the substrate 5. Since the coating liquid is once diffused in the manifold 11, the flow rate of the coating liquid discharged from the discharge port 13 can be made uniform along the longitudinal direction. In addition, the surface of the base material 5 is a surface (surface facing the upper coating nozzle 10) facing the upper side of the base material 5 which is transported along the substantially horizontal direction by the transport mechanism 60. On the other hand, the back surface of the base material 5 is a surface facing the lower side of the base material 5 that is transported along the substantially horizontal direction by the transport mechanism 60 (a surface facing the lower coating nozzle 30).

  The upper coating nozzle 10 is provided with an upper coating reference surface 14. The upper coating reference surface 14 is a flat surface formed of the same material as the upper coating nozzle 10 (stainless steel in this embodiment). The upper coating reference surface 14 is a plane parallel to the base material 5 that is transported below the upper coating nozzle 10 (in this embodiment, since the base material 5 is transported along the horizontal direction). The width of the upper coating reference surface 14 (the length along the conveyance direction of the base material 5) is larger than the width of the discharge port 33 of the lower coating nozzle 30 described later. As shown in FIG. 2, the upper coating reference surface 14 is provided below the discharge port 13 of the upper coating nozzle 10, that is, at a position close to the base material 5. Preferably, the upper coating reference surface 14 is a smooth polished surface.

  Similarly, a manifold 31 and a flow path 32 are formed inside the lower coating nozzle 30. The lower end side of the flow path 32 communicates with the manifold 31, and the upper end side outlet is defined as a slit-like discharge port 33. A coating liquid is supplied to the manifold 31 from a coating liquid supply source (not shown). The supplied coating liquid is diffused in the longitudinal direction of the discharge port 33 (the width direction of the base material 5) in the manifold 31, and then flows through the flow path 32 to the discharge port 33. From 33, it discharges toward the back surface of the base material 5. Since the coating liquid is once diffused in the manifold 31, the flow rate of the coating liquid discharged from the discharge port 33 can be made uniform along the longitudinal direction. The coating liquid supply source of the upper coating nozzle 10 and the coating liquid supply source of the lower coating nozzle 30 may be the same.

  A lower coating reference surface 34 is attached to the lower coating nozzle 30. The lower coating reference surface 34 is a flat surface formed of the same material as the lower coating nozzle 30 (stainless steel in this embodiment). The lower coating reference surface 34 is a plane parallel to the base material 5 that is transported above the lower coating nozzle 30 (in this embodiment, since the base material 5 is transported along the horizontal direction). is there. The width of the lower coating reference surface 34 (the length along the conveying direction of the base material 5) is larger than the width of the discharge port 13 of the upper coating nozzle 10. As shown in FIG. 2, the lower coating reference surface 34 is provided above the discharge port 33 of the lower coating nozzle 30, that is, at a position close to the base material 5. Preferably, the lower coating reference surface 34 is a smooth polished surface.

  Returning to FIG. 1, the double-side coating apparatus 1 includes an upper movement mechanism 20 that moves the upper coating nozzle 10 and a lower movement mechanism 40 that moves the lower coating nozzle 30. The upper moving mechanism 20 moves the upper coating nozzle 10 with respect to the surface of the substrate 5. Specifically, the upper moving mechanism 20 slides the upper coating nozzle 10 along the conveying direction of the base material 5 and moves it up and down along the vertical direction. These moving operations can be realized by various known drive mechanisms such as a combination of a ball screw and a pulse motor or an actuator. In particular, since the vertical movement along the vertical direction requires a precise operation for adjusting the distance between the discharge port 13 of the upper coating nozzle 10 and the surface of the substrate 5, for example, the upper coating nozzle 10 It is preferable that the ball screw screwed to both ends in the longitudinal direction is realized by a drive mechanism that is driven to rotate by a pulse motor. With such a drive mechanism, the inclination angle of the upper coating nozzle 10 with respect to the substrate 5 can be adjusted by individually raising and lowering both ends in the longitudinal direction of the upper coating nozzle 10.

  On the other hand, the lower movement mechanism 40 moves the lower coating nozzle 30 relative to the back surface of the substrate 5. Specifically, the lower movement mechanism 40 slides the lower coating nozzle 30 along the conveyance direction of the base material 5 and moves it up and down along the vertical direction. These moving operations can be realized by various known drive mechanisms such as a combination of a ball screw and a pulse motor or an actuator. In particular, since the vertical movement along the vertical direction requires a precise operation for adjusting the interval between the discharge port 33 of the lower coating nozzle 30 and the back surface of the base material 5, It is preferably realized by a drive mechanism in which a ball screw screwed to both ends in the longitudinal direction of the lower coating nozzle 30 is rotated by a pulse motor. With such a drive mechanism, the inclination angle of the lower coating nozzle 30 with respect to the substrate 5 can be adjusted by individually raising and lowering both ends in the longitudinal direction of the lower coating nozzle 30.

  When the electrode is manufactured by the double-sided coating apparatus 1 having the above-described configuration, the upper coating nozzle 10 and the lower coating nozzle 30 are used while the substrate 5 is continuously conveyed by a roll-to-roll by the conveyance mechanism 60. The coating liquid is applied simultaneously on the front and back surfaces of the substrate 5. When performing double-sided simultaneous coating, as shown in FIGS. 1 and 2, the upper coating nozzle 10 and the lower coating nozzle 30 are disposed so as to face each other with the substrate 5 interposed therebetween. Further, the upper coating nozzle 10 is moved up and down by the upper movement mechanism 20 so that the discharge port 13 of the upper coating nozzle 10 and the surface of the base material 5 are spaced apart from each other, and the lower coating nozzle 30 discharges. The lower coating nozzle 30 is moved up and down by the lower movement mechanism 40 so that the outlet 33 and the back surface of the base material 5 are at a predetermined interval. When performing both-side simultaneous coating, the upper coating reference surface 14 of the upper coating nozzle 10 and the lower coating reference surface 34 of the lower coating nozzle 30 are not in contact with the front and back surfaces of the substrate 5. An upper coating nozzle 10 and a lower coating nozzle 30 are arranged.

  The upper coating nozzle 10 discharges the coating liquid from the discharge port 13 onto the surface of the substrate 5 that is transported in a substantially horizontal direction by the transport mechanism 60. That is, the upper coating nozzle 10 discharges the coating liquid from the upper side of the substrate 5. One lower coating nozzle 30 discharges the coating liquid from the discharge port 33 to the back surface of the substrate 5 that is transported in a substantially horizontal direction by the transport mechanism 60. That is, the lower coating nozzle 30 discharges the coating liquid from the lower side of the substrate 5.

When manufacturing a positive electrode with the double-side coating apparatus 1, as a coating liquid of a positive electrode material, for example, lithium cobaltate (LiCoO ₂ ) that is a positive electrode active material, carbon (C) that is a conductive auxiliary agent, and a 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 double-side coating apparatus 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 coating liquid of the positive electrode material is applied from the upper coating nozzle 10 to the surface of the base material 5, a coating liquid of the positive electrode material is also applied from the lower coating nozzle 30 to the back surface of the base material 5. Work. If the negative electrode material coating liquid is applied to the surface of the substrate 5 from the upper coating nozzle 10, the negative electrode material coating liquid is also applied to the back surface of the substrate 5 from the lower coating nozzle 30. Work.

  The upper coating nozzle 10 and the lower coating nozzle 30 discharge the coating liquid from the discharge port 13 and the discharge port 33, respectively, at an equal discharge flow rate. When the upper coating nozzle 10 and the lower coating nozzle 30 arranged so as to face each other with the base material 5 interposed therebetween are discharged from the upper and lower sides to the base material 5 at the same discharge flow rate, the same as the base material 5 The coating liquid is deposited at a fluid pressure equal to the front surface and back surface of the position. As a result, the base material 5 is stably held at a predetermined position between the upper coating nozzle 10 and the lower coating nozzle 30 by the balance of the hydraulic pressure discharged from the front and back surfaces of the base material 5, The interval between the discharge port 13 of the upper coating nozzle 10 and the surface of the substrate 5 and the interval between the discharge port 33 of the lower coating nozzle 30 and the back surface of the substrate 5 are always constant. Therefore, the upper coating nozzle 10 and the lower coating nozzle 30 can uniformly coat the coating liquid on the front surface and the back surface of the substrate 5.

  As shown in FIG. 2, when the upper coating nozzle 10 and the lower coating nozzle 30 are ejecting the coating liquid from the upper and lower sides of the substrate 5 and the substrate 5 is conveyed as indicated by the arrow AR2, A coating film of the coating liquid is formed on the front surface and the back surface of 5. The upper coating nozzle 10 and the lower coating nozzle 30 may continuously apply the coating liquid on the front and back surfaces of the substrate 5 to be conveyed, or intermittently apply the coating liquid. You may make it apply. However, when intermittent coating is performed, the upper coating nozzle 10 and the lower coating nozzle 30 discharge the coating liquid at the same timing, and the coating liquid is applied to the front and back surfaces of the same region of the substrate 5. To do.

  The substrate 5 coated with the coating liquid on both the front and back surfaces by the upper coating nozzle 10 and the lower coating nozzle 30 is conveyed to the drying unit 50, and the substrate 5 is heated to evaporate the solvent from the coating liquid. Then, the coating film of the coating solution is dried. And when the base material 5 is carried out from the drying part 50, the coating film of a coating liquid is fully dried.

  The base material 5 carried out from the drying unit 50 reaches the measurement unit 70 and passes through the inside thereof. The measurement part 70 measures the film thickness of the coating film currently formed in the front and back of the base material 5 after the drying process which passes. A measurement result by the measurement unit 70 is transmitted to the control unit 90. The control unit 90 calculates the weight per unit area of the coating film formed on the front and back surfaces of the substrate 5 from the film thickness measured by the measurement unit 70. Then, the base material 5 that has passed through the measuring unit 70 is taken up by the take-up roller 62.

  By the way, in the double-side coating apparatus 1, an appropriate coating process is performed from the film thickness of the coating film measured by the measuring unit 70 (or the weight per unit area of the coating film calculated based on the measurement result). The coating state is confirmed by determining whether or not it is performed. That is, when the film thickness of the coating film measured by the measuring unit 70 is out of the appropriate range set in advance, it is determined that the coating is not performed properly. And when it determines with a coating defect, the operation | movement of the double-sided coating apparatus 1 is stopped and the upper side coating nozzle 10 and the lower side coating nozzle 30 are adjusted.

  Here, in the double-side coating apparatus 1, since the upper side coating nozzle 10 and the lower side coating nozzle 30 simultaneously apply the coating liquid to the front and back surfaces of the base material 5, both the front and back surfaces of the base material 5 are applied. The film thickness is measured by the measuring unit 70 in a state where the coating film is formed. Therefore, the measurement unit 70 measures the total film thickness of the front surface and the back surface of the substrate 5. If it does so, the separate coating state of the surface of the base material 5 and a back surface may be unable to be determined.

  FIG. 3 is a diagram schematically showing the coating state of the front surface and the back surface of the substrate 5. In the example shown in FIG. 3A, the film thickness of the coating film is uniform on both the front surface and the back surface of the substrate 5, and the coating liquid is appropriately applied and the drying process is performed. In this case, the film thickness of the coating film measured by the measurement unit 70 is of course within the appropriate range.

  On the other hand, in the example shown in FIG. 3 (b), the film thickness of the coating film is not uniform when viewed on the front surface and the back surface of the substrate 5. When the coating state is as shown in FIG. 3B, the electrode is a defective product. However, in the case of the example as shown in FIG. 3B, the coating film thickness on the front surface and the back surface of the base material 5 is non-uniform so as to compensate each other. The thickness is uniform. Accordingly, when the measurement unit 70 measures the total coating film thickness of the front and back surfaces of the substrate 5, the measurement result is within the appropriate range. That is, although the measurement result by the measurement unit 70 is appropriate, defective coating occurs on each of the front surface and the back surface of the base material 5, and a defective product is manufactured.

  Therefore, in the present embodiment, the coating state of the front surface and the back surface of the substrate 5 is individually measured as follows, and the adjustment of the upper coating nozzle 10 and the lower coating nozzle 30 is individually performed based on the measurement. Is going. Such adjustment work may be performed, for example, when the double-side coating apparatus 1 is maintained and restarted.

  First, in the same manner as when performing a normal coating process, the base material 5 fed from the unwinding roller 61 of the transport mechanism 60 is taken up by the take-up roller 62 so that the base material 5 is continuously transported. Then, while continuously transporting the substrate 5 by the transport mechanism 60, the lower movement mechanism 40 moves the lower coating nozzle 30 to bring the lower coating reference surface 34 into contact with the back surface of the substrate 5. At this time, the lower movement mechanism 40 is moved to the lower coating so that the lower coating reference surface 34 contacts the back surface of the substrate 5 at the first reference position facing the discharge port 13 of the upper coating nozzle 10. The nozzle 30 is moved. Here, the “first reference position” means that the base material 5 is stabilized by the hydraulic pressure balance of the coating liquid discharged from the upper coating nozzle 10 and the lower coating nozzle 30 during the normal coating process described above. It is a position corresponding to the back surface of the base material 5 when being held.

  When the lower coating reference surface 34 comes into contact with the back surface of the base material 5 at the first reference position, the base material 5 passes under the discharge port 13 of the upper coating nozzle 10 during normal coating processing. The substrate 5 is securely held in the transport path. Since the lower coating reference surface 34 is provided at a position closer to the substrate 5 than the discharge port 33 of the lower coating nozzle 30, the lower coating reference surface 34 contacts the back surface of the substrate 5. However, the discharge port 33 is prevented from contacting the substrate 5. In addition, since the lower coating reference surface 34 comes into contact with the back surface of the substrate 5 conveyed by the conveying mechanism 60, the substrate 5 slides with respect to the lower coating reference surface 34. However, since the conveyance distance of the base material 5 for nozzle adjustment is very short, it is not a problem. Further, it is preferable that the lower coating reference surface 34 is a smooth polished surface so that the base material 5 slides smoothly with respect to the lower coating reference surface 34. Alternatively, a lubricating member may be sandwiched between the base material 5 and the lower coating reference surface 34.

  Subsequently, as shown in FIG. 4, while the lower coating reference surface 34 is brought into contact with the back surface of the substrate 5 at the first reference position facing the upper coating nozzle 10, the upper coating nozzle 10 to the substrate. The coating liquid is discharged onto the surface of 5. A test in which the coating liquid is applied only to the surface of the substrate 5 when the substrate 5 is conveyed as indicated by the arrow AR4 while discharging the coating liquid from the upper coating nozzle 10 to the surface of the substrate 5. Coating progresses. The transport distance of the base material 5 when performing this test coating is sufficient as long as the film thickness can be measured by the measuring unit 70.

  The base material 5 on which the coating liquid coating film is formed only on the surface is conveyed to the drying unit 50, where the coating film is dried. And the base material 5 carried out from the drying part 50 reaches the measurement part 70, and the film thickness of the coating film currently formed in the surface of the base material 5 is measured by the measurement part 70. FIG. At this time, since the coating film is formed only on the surface of the base material 5, the measuring unit 70 can accurately measure the film thickness of the coating film formed on the surface of the base material 5. The coating film formed on the surface of the substrate 5 is based on the coating process from the upper coating nozzle 10. That is, the measuring unit 70 can measure only the coating state of the surface of the substrate 5 by the upper coating nozzle 10.

  The upper coating nozzle 10 is adjusted based on the measurement result of the measuring unit 70. Specifically, when the film thickness of the coating film on the surface of the base material 5 measured by the measuring unit 70 is uneven and the coating state is poor, the discharge port 13 of the upper coating nozzle 10 and the base material 5 and the discharge flow rate of the coating liquid from the upper coating nozzle 10 are adjusted. Furthermore, the inclination angle of the upper coating nozzle 10 with respect to the substrate 5 may be adjusted.

  After the necessary adjustment of the upper coating nozzle 10 is completed, the above procedure is repeated again to measure the coating state of the surface of the substrate 5. And said procedure is repeated until the film thickness of the coating film of the surface of the base material 5 measured by the measurement part 70 becomes uniform, and a coating state becomes favorable.

  Next, adjustment work for the lower coating nozzle 30 is performed, which is generally the above-described operation inverted up and down. That is, while the base material 5 is continuously transported by the transport mechanism 60, the upper movement mechanism 20 moves the upper coating nozzle 10 to bring the upper coating reference surface 14 into contact with the surface of the base material 5. At this time, the upper movement mechanism 20 moves the upper coating nozzle 10 so that the upper coating reference surface 14 contacts the surface of the substrate 5 at the second reference position facing the discharge port 33 of the lower coating nozzle 30. Move. Here, the “second reference position” means that the substrate 5 is stabilized by the hydraulic pressure balance of the coating liquid discharged from the upper coating nozzle 10 and the lower coating nozzle 30 during the normal coating process described above. It is a position corresponding to the surface of the substrate 5 when being held.

  When the upper coating reference surface 14 comes into contact with the surface of the substrate 5 at the second reference position, the substrate 5 passes immediately above the discharge port 33 of the lower coating nozzle 30 during a normal coating process. The substrate 5 is securely held in the transport path. Since the upper coating reference surface 14 is provided at a position closer to the base material 5 than the discharge port 13 of the upper coating nozzle 10, even if the upper coating reference surface 14 contacts the surface of the base material 5, The outlet 13 is prevented from contacting the substrate 5. Similarly to the lower coating reference surface 34 described above, the upper coating reference surface 14 is a smooth polished surface so that the base material 5 slides smoothly with respect to the upper coating reference surface 14. Is preferred. Alternatively, a lubricating member may be sandwiched between the base material 5 and the upper coating reference surface 14.

  Subsequently, as shown in FIG. 5, the base coating nozzle 30 is moved from the base coating nozzle 30 while the base coating surface 14 is brought into contact with the surface of the substrate 5 at the second base position facing the base coating nozzle 30. A coating solution is discharged onto the back surface of the material 5. When the substrate 5 is conveyed as indicated by the arrow AR5 while discharging the coating solution from the lower coating nozzle 30 to the back surface of the substrate 5, the coating solution is applied only to the back surface of the substrate 5. Test coating proceeds. The transport distance of the base material 5 when performing this test coating is sufficient as long as the film thickness can be measured by the measuring unit 70.

  The base material 5 on which the coating liquid coating film is formed only on the back surface is conveyed to the drying unit 50, where the coating film is dried. And the base material 5 carried out from the drying part 50 arrives at the measurement part 70, and the film thickness of the coating film currently formed in the back surface of the base material 5 is measured by the measurement part 70. FIG. At this time, since the coating film is formed only on the back surface of the base material 5, the measuring unit 70 can accurately measure the film thickness of the coating film formed on the back surface of the base material 5. The coating film formed on the back surface of the substrate 5 is due to the coating process from the lower coating nozzle 30. That is, the measuring unit 70 can measure only the coating state of the back surface of the substrate 5 by the lower coating nozzle 30.

  Based on the measurement result of the measurement unit 70, the lower coating nozzle 30 is adjusted. Specifically, when the coating film thickness on the back surface of the substrate 5 measured by the measuring unit 70 is non-uniform and the coating state is poor, the discharge port 33 and the base of the lower coating nozzle 30 are inferior. The distance from the back surface of the material 5 and the discharge flow rate of the coating liquid from the lower coating nozzle 30 are adjusted. Furthermore, the inclination angle of the lower coating nozzle 30 with respect to the substrate 5 may be adjusted.

  After the necessary adjustment of the lower coating nozzle 30 is completed, the above procedure is repeated again to measure the coating state of the back surface of the substrate 5. And said procedure is repeated until the film thickness of the coating film of the back surface of the base material 5 measured by the measurement part 70 becomes uniform, and a coating state becomes favorable. As described above, after the adjustment is individually made for each of the upper coating nozzle 10 and the lower coating nozzle 30, as shown in FIG. 2, the upper coating nozzle 10, the lower coating nozzle 30, Are moved to the opposite positions, and normal double-sided simultaneous coating processing is performed from both nozzles.

  In this embodiment, in the double-side coating apparatus 1 that normally performs double-side simultaneous coating, the coating solution is individually applied to each of the front surface and the back surface of the substrate 5, and the coating state is measured. Based on the results, the upper coating nozzle 10 and the lower coating nozzle 30 are individually adjusted. When the coating liquid is applied only to one surface of the base material 5, the base material 5 can only be discharged from the one surface by simply discharging the coating liquid from the upper coating nozzle 10 or the lower coating nozzle 30. Therefore, the upper coating reference surface 14 or the lower coating reference surface 34 is brought into contact with the substrate 5. By bringing the lower coating reference surface 34 into contact with the back surface of the substrate 5 at the first reference position facing the discharge port 13 of the upper coating nozzle 10, the coating liquid is discharged only from the upper coating nozzle 10. Sometimes, the substrate 5 is reliably held at the same position as that in the normal double-side coating process (FIG. 4). Further, the upper coating reference surface 14 is brought into contact with the surface of the substrate 5 at the second reference position facing the discharge port 33 of the lower coating nozzle 30, so that the coating liquid can be applied only from the lower coating nozzle 30. The substrate 5 is surely held at the same position as that during the normal double-side coating process even when discharging (FIG. 5). Thereby, also when apply | coating a coating liquid only to either one of the surface of the base material 5 or a back surface, coating will be performed on the same conditions as the time of normal double-sided coating.

  And since the upper side coating nozzle 10 and the lower side coating nozzle 30 are individually adjusted based on the measurement result of each coating state of the surface and the back surface of the base material 5, the upper side coating nozzle 10 and the lower side The discharge processing by the coating nozzle 30 can be made accurate individually. If it does in this way, as shown in FIG.3 (b), for example, even if the coating-film film thickness of the front and back of the base material 5 is in an appropriate range, the coating defect generate | occur | produced in each of the surface and the back surface. Even in the case where it is, the upper coating nozzle 10 and the lower coating nozzle 30 can be appropriately adjusted by detecting the coating defect. As a result, the coating liquid can be appropriately applied to each of the front surface and the back surface of the substrate 5. Further, the upper coating reference surface 14 and the lower coating reference surface 34 are simple planes attached to the upper coating nozzle 10 and the lower coating nozzle 30, respectively, so that the cost is not particularly increased.

  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 upper coating reference surface 14 is attached to the upper coating nozzle 10 and the lower coating reference surface 34 is attached to the lower coating nozzle 30. 14 and the lower coating reference surface 34 may be separate from the coating nozzle.

  FIG. 6 is a cross-sectional view illustrating another example of the configuration of the upper coating nozzle 10 and the lower coating nozzle 30. In FIG. 6, the same reference numerals are given to the same elements as those in the above embodiment. In the example shown in FIG. 6, the upper reference block 15 is provided separately from the upper coating nozzle 10. The lower end surface of the upper reference block 15 is an upper coating reference surface 16. The upper coating reference surface 16 is a flat surface similar to the upper coating reference surface 14 of the above embodiment. The upper reference block 15 is moved independently of the upper coating nozzle 10 by a driving mechanism different from the upper moving mechanism 20.

  A lower reference block 35 is provided separately from the lower coating nozzle 30. An upper end surface of the lower reference block 35 is a lower coating reference surface 36. The lower coating reference surface 36 is a flat surface similar to the lower coating reference surface 34 of the above embodiment. The lower reference block 35 is moved independently of the lower coating nozzle 30 by a driving mechanism different from the lower moving mechanism 40.

  In the configuration of the example shown in FIG. 6, when performing the test coating by the upper coating nozzle 10, the lower coating is applied to the back surface of the substrate 5 at the first reference position facing the discharge port 13 of the upper coating nozzle 10. The coating liquid is discharged from the upper coating nozzle 10 onto the surface of the substrate 5 while contacting the reference surface 36. When performing test coating using the lower coating nozzle 30, the upper coating reference surface 16 is brought into contact with the surface of the substrate 5 at the second reference position facing the discharge port 33 of the lower coating nozzle 30. Meanwhile, the coating liquid is discharged from the lower coating nozzle 30 onto the back surface of the substrate 5. And based on the measurement result of each coating state of the surface of the base material 5, and the back surface, the upper side coating nozzle 10 and the lower side coating nozzle 30 are adjusted separately. Even in this case, similarly to the above-described embodiment, the upper coating nozzle 10 and the lower coating nozzle 30 can be appropriately adjusted individually, and coating is appropriately performed on each of the front surface and the back surface of the substrate 5. The liquid can be applied.

  Moreover, in the said embodiment, although the coating part film thickness of the base material 5 after a drying process was measured in-line by the measurement part 70 provided with the transmission type sensor using X-rays etc., in this, Instead, an off-line measurement in which the weight of the coating film per unit area is measured by punching out a standard-sized test piece from the substrate 5 after the drying treatment and directly measuring the weight with an electronic balance or the like. good.

  Further, the upper coating nozzle 10 and the lower coating nozzle 30 are not limited to slit nozzles having one slit-like discharge ports 13 and 33, and may have a plurality of slits. Alternatively, a nozzle that discharges the coating liquid from a substantially circular discharge port may be used.

  Moreover, in the said embodiment, although the upper side coating nozzle 10 and the lower side coating nozzle 30 were provided in the upper and lower sides of the base material 5 and double-sided simultaneous coating was performed, it is conveying the base material 5 inclining from a horizontal surface. Alternatively, 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.

  Moreover, the coating liquid used as the object which performs the coating process using the technique which concerns on this invention is not limited to the electrode material of a lithium ion secondary battery, For example, solar cell material (electrode material, sealing material) Or a coating solution for an insulating film or protective film of an electronic material. Alternatively, the technique according to the present invention may be used to apply a pigment or adhesive coating solution.

DESCRIPTION OF SYMBOLS 1 Double-side coating apparatus 5 Base material 10 Upper coating nozzle 13,33 Discharge port 14,16 Upper coating reference surface 20 Upper movement mechanism 30 Lower coating nozzle 34,36 Lower coating reference surface 40 Lower movement mechanism DESCRIPTION OF SYMBOLS 50 Drying part 60 Conveying mechanism 61 Unwinding roller 62 Winding-up roller 70 Measuring part 90 Control part

Claims (8)

A nozzle adjustment method for adjusting a first coating nozzle for coating a coating liquid on a first surface of a substrate and a second coating nozzle for coating a coating liquid on a second surface,
A conveying step of continuously conveying the substrate by winding the substrate fed from the first roller with the second roller;
The first surface of the substrate from the first coating nozzle while contacting the first coating reference surface with the second surface of the substrate at a first reference position facing the first coating nozzle. A first test coating process for discharging the coating liquid to
A first measurement step of measuring the coating state of the first surface of the substrate;
A first adjustment step of adjusting the first coating nozzle based on a measurement result in the first measurement step;
The second surface of the substrate from the second coating nozzle while contacting the second coating reference surface with the first surface of the substrate at a second reference position facing the second coating nozzle. A second test coating process for discharging the coating liquid to
A second measuring step for measuring the coating state of the second surface of the substrate;
A second adjustment step of adjusting the second coating nozzle based on the measurement result in the second measurement step;
A nozzle adjustment method comprising: In the nozzle adjustment method of Claim 1,
In the first adjustment step, an interval between the first surface of the substrate and the first coating nozzle and a discharge flow rate of the coating liquid from the first coating nozzle are adjusted,
In the second adjustment step, the gap between the second surface of the substrate and the second coating nozzle and the discharge flow rate of the coating liquid from the second coating nozzle are adjusted. Method. In the nozzle adjustment method of Claim 1 or Claim 2,
The first coating reference surface is attached to the second coating nozzle,
The nozzle adjustment method, wherein the second coating reference surface is attached to the first coating nozzle. A double-sided coating device that coats a coating liquid on 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 coating nozzle for discharging a coating liquid onto the first surface of the substrate;
A second coating nozzle that is provided opposite to the first coating nozzle across the substrate, and that discharges a coating liquid onto the second surface of the substrate;
A first nozzle moving mechanism for moving the first coating nozzle relative to the first surface of the substrate;
A second nozzle moving mechanism for moving the second coating nozzle relative to the second surface of the substrate;
When adjusting the first coating nozzle, a first coating reference surface that contacts the second surface of the base material at a first reference position facing the first coating nozzle;
When adjusting the second coating nozzle, a second coating reference surface that contacts the first surface of the substrate at a second reference position facing the second coating nozzle;
A double-sided coating apparatus comprising: In the double-side coating apparatus according to claim 4,
The first coating reference surface is attached to the second coating nozzle,
The double-side coating apparatus, wherein the second coating reference surface is attached to the first coating nozzle. In the double-side coating apparatus according to claim 5,
The first coating reference surface is provided at a position closer to the substrate than the discharge port of the second coating nozzle,
The double-side coating apparatus, wherein the second coating reference surface is provided at a position closer to the substrate than the discharge port of the first coating nozzle. It is a coating nozzle used when coating the coating liquid on both sides of the substrate,
A discharge port for discharging the coating liquid onto one side of the substrate that is continuously conveyed;
When adjusting the coating nozzle on the other surface side of the substrate, a coating reference surface that contacts the one surface of the substrate;
A coating nozzle characterized by comprising: The coating nozzle according to claim 7,
The coating nozzle, wherein the coating reference surface is provided at a position closer to the substrate than the discharge port.

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