Coating device

Abstract

The present application provides a coating device capable of coating a coating film with good quality and uniform thickness. Specifically, it is provided with: a first flow path (21) which is a flow path for supplying a coating liquid (3) to supply a coating liquid to a mold (10); a first manifold (6) which is connected to the first flow path (21) and accumulates the coating liquid (3) flowing from the first flow path (21); a plurality of second flow paths (24) which are connected to the first manifold (6); a second manifold (11) which is connected to the second flow paths (24) and a slit (12), is formed long in the width direction, and accumulates the coating liquid (3) flowing from the second flow paths (24); and an adjusting portion (30) which is provided in the middle of at least one of the second flow paths (24) and adjusts the flow rate of the coating liquid (3) flowing in the second flow paths (24).

Description

TECHNICAL FIELD

[0001] The present application relates to a coating device and a coating method for coating a coating film on a substrate. BACKGROUND

[0002] A coating film is formed on a substrate transported in a roll-to-roll manner by coating slurry from a discharge port of a die to manufacture a plate of a battery and the like. In the case of a battery, for example, the thickness of the coating film formed on the substrate directly affects the charge and discharge capacity of the battery, and therefore, the film thickness management of the coating liquid (slurry) coated on the substrate becomes very important. That is, the coating liquid needs to be coated at a uniform thickness in the width direction and the transport direction of the substrate.

[0003] Patent Document 1 describes a structure in which a discharge port (adjustment portion) is provided, and even if the slurry discharge operation is continued for a long time, the thickness of the coating film layer formed on the substrate is made uniform.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENT

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-97198 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the coating device described in Patent Document 1, the slurry is easily separated by applying pressure to the slurry inside the die. Therefore, in the case where the slurry discharged from the discharge port is returned to the tank to be reused to effectively use the slurry, there is a problem that the quality of the coating film can be affected.

[0009] The present application was made in view of the above-described problems, and an object thereof is to provide a coating device capable of coating a coating film of good quality and uniform thickness.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] To solve the above-described problems, the coating device of the present application discharges a coating liquid from a slit formed in a die to form a coating film on a substrate, the slit being formed long in one direction, characterized by comprising: a first flow path which is a flow path for supplying the coating liquid to the die; a first manifold which is connected to the first flow path and accumulates the coating liquid flowing in from the first flow path; a plurality of second flow paths which are connected to the first manifold; a second manifold which is connected to the second flow paths and the slit, is formed long in the one direction, and accumulates the coating liquid flowing in from the second flow paths; and an adjustment portion which is provided in the middle of at least one of the second flow paths and adjusts the flow rate of the coating liquid flowing in the second flow path.

[0012] According to the above-described coating apparatus, a coating film with good quality and uniform thickness can be formed. Specifically, by having a first manifold and an adjustment unit provided in the second flow path, the flow distribution of the coating liquid flowing into the second manifold in the width direction can be precisely adjusted, so that the coating liquid can be precisely sprayed from the mold openings to form a uniform coating film on the substrate in the width direction. Furthermore, since the coating liquid does not overflow and return to the tank, a coating film of good quality can be formed.

[0013] Alternatively, preferably, the first manifold and the adjustment part are disposed outside the mold.

[0014] This prevents the mold structure from becoming too complex.

[0015] In addition, preferably, at least the flow path portion of the coating liquid of the first manifold and the regulating section is disposed inside the mold.

[0016] This prevents the piping structure from becoming complicated up to the mold.

[0017] In addition, preferably, the lengths of the plurality of second flow paths are equal to each other.

[0018] Therefore, it becomes easy to adjust the flow distribution of the coating liquid flowing into the second manifold in the width direction.

[0019] Alternatively, the first manifold may be elongated in one direction, and the connection portions of the multiple second flow paths to the first manifold may be arranged along the length of the first manifold.

[0020] Therefore, the length of each second flow path can be easily adjusted.

[0021] Furthermore, it is preferable to have an intermittent supply section that intermittently supplies coating liquid on the supply path that supplies coating liquid to the first flow path.

[0022] Therefore, it is possible to intermittently apply a coating of uniform thickness in the width direction to the substrate.

[0023] Alternatively, the coating solution can be a slurry used in the manufacture of battery plates.

[0024] Since the slurry used in the manufacture of battery plates is easy to separate, it is preferable to use the coating apparatus of the present invention, which does not cause a portion of the coating liquid supplied to the mold to return to the tank.

[0025] Invention Effects

[0026] The coating apparatus according to the present invention is capable of coating a film of good quality and uniform thickness. Attached Figure Description

[0027] Figure 1 This is a diagram illustrating the schematic structure of a coating apparatus according to one embodiment of the present invention.

[0028] Figure 2 yes Figure 1 A sectional view from direction a.

[0029] Figure 3 (a) is Figure 1 (b) is a sectional view of the plate from direction b, and (b) is a top view of the plate.

[0030] Figure 4 These are figures illustrating other embodiments of the present invention. Detailed Implementation

[0031] Reference Figures 1 to 3 A coating apparatus 1 according to one embodiment of the present invention will be described. Figure 1 This is a diagram illustrating the schematic structure of the coating apparatus according to this embodiment. Figure 2 yes Figure 1 A sectional view from direction a. Figure 3 (a) is Figure 1 (b) is a sectional view of the pad 15 viewed from direction b.

[0032] The coating apparatus 1 is used to coat a coating liquid 3 onto a substrate 2 that is conveyed in a roller-to-roll manner. The coating liquid 3 is applied along the conveying direction MD of the substrate 2 with a uniform thickness (uniform coating amount). It should be noted that the width direction TD of the substrate 2 is orthogonal to the conveying direction MD of the substrate 2. Figure 1 The Y-axis direction in the diagram corresponds to this.

[0033] The coating apparatus 1 includes a mold 10 that is elongated in the width direction of a substrate 2 and a supply unit 20 for supplying coating liquid 3 to the mold 10. In the mold 10, its length direction ( Figure 1 The Y-axis direction in the coating apparatus is called the width direction TD, which is the same as the width direction TD of the substrate 2. In this coating apparatus 1, a roller 5 is provided facing the mold 10, and the width direction TD of the mold 10 is parallel to the direction of the rotation center line of the roller 5. The substrate 2 is guided by the roller 5, and the interval (gap) between the substrate 2 and the mold 10 (the front end of the slit 12 described later) is kept constant. Under this state, the coating liquid 3 is applied.

[0034] Furthermore, the coating liquid 3 in this embodiment is a slurry for manufacturing battery plates, in which active materials, binders, and conductive additives are dispersed. It should be noted that, in this embodiment, the slurry sprayed from the mold 10 has a viscosity of several thousand to tens of thousands of cP (when the shear rate = 1).

[0035] The mold 10 is composed of a first segment 13 having a first lip 13a with a pointed shape and a second segment 14 having a second lip 14a with a pointed shape, with a pad 15 sandwiched between them. Figure 2 yes Figure 1 A sectional view from direction a. Figure 3 (a) is Figure 1 A sectional view from direction b. Figure 3 (b) indicates the pad 15. The mold 10 has a second manifold 11 and a slit 12 connected to it. The second manifold 11 is a generally cylindrical space elongated in the width direction TD, used to collect the coating liquid 3. Additionally, an outlet 18, serving as the open end of the slit 12, is formed between the first lip 13a and the second lip 14a. That is, the second manifold 11 and the outlet 18 are connected via the slit 12.

[0036] The slit 12, like the second manifold 11, is formed in the width direction TD and its width dimension is determined by the internal dimension W of the pad 15 (refer to...). Figure 3 As determined by (b), a coating liquid 3 with a width dimension approximately the same as that of the slit 12 can be applied to the substrate 2. The gap dimension (height dimension) of the slit 12 is, for example, 0.4 mm to 1.5 mm. In this embodiment, the mold 10 is arranged with the gap direction of the slit 12 being vertical and the width direction being horizontal. That is, the mold 10 is arranged with the second manifold 11 and the slit 12 arranged in a horizontal direction. Therefore, the direction in which the coating liquid 3 accumulated in the second manifold 11 flows to the substrate 2 through the slit 12 and the nozzle 18 is horizontal.

[0037] Furthermore, by changing the thickness of the pad 15, the pressure (coating pressure) inside the second manifold 11 can be adjusted, and the coating film thickness can be freely changed through this adjustment.

[0038] In addition, such as Figure 2 As shown, multiple inlets 27 (inlets 27a to 27d) for coating liquid 3 are provided throughout the width direction on the second manifold 11, and the coating liquid 3 is filled into the second manifold 11 through the inlets 27.

[0039] Furthermore, in this embodiment, the direction in which the coating liquid 3 flows from the nozzle 18 to the substrate 2 is set to a horizontal direction, but it is not limited to this and can be appropriately changed. For example, the direction in which the coating liquid 3 flows from the nozzle 18 to the substrate 2 can be set to an upward direction or a downward direction, and can be set to any direction.

[0040] The supply unit 20 includes: a tank 22 for storing coating liquid 3; a pipe, i.e., a first flow path 21, connected to the tank 22 and serving as a flow path for supplying coating liquid 3 to the mold 10; and a pump 23 for supplying coating liquid 3 in the tank 22 to the mold 10 through the first flow path 21.

[0041] A manifold member 7 is provided between the supply unit 20 and the second manifold 11 in the flow path of the coating liquid 3. This manifold member 7 has a generally cylindrical space formed in one direction for accumulating the coating liquid 3, namely the first manifold 6. In this embodiment, the length direction of the first manifold 6 is the same as the length direction (i.e., the width direction TD) of the mold 10 and the second manifold 11. Regarding the size (cross-sectional area) of each manifold, the second manifold 11 is generally smaller than the first manifold 6, but since their respective functions are different, the size relationship cannot be generalized. The first manifold 6 is a manifold for equally supplying from the pump 23 to each of the multiple adjustment sections 30 arranged in the width direction of the mold 10, and is preferably as large as possible.

[0042] On the other hand, since the second manifold 11, located downstream of the adjustment unit 30, has the function of adjusting the film thickness in the width direction, appropriate dimensions are required based on the coating liquid supply amount, supply speed, thickness, and adjustment amount of the adjustment unit. Furthermore, the second manifold 11 is not necessarily connected in the width direction; it may also be divided into multiple sections in the width direction.

[0043] An inlet 25 is provided at a designated location (the central portion in this embodiment) of the first manifold 6, through which the coating liquid 3 supplied from the supply unit 20 is filled into the first manifold 6.

[0044] like Figure 2 As shown, a plurality of outlets 26 (outlets 26a to 26d) for the coating liquid 3 are provided along the length of the first manifold 6. The outlets 26a to 26d of the first manifold 6 are connected to the inlets 27a to 27d of the second manifold 11 via pipes or the like, forming flow paths for the coating liquid 3. In this invention, these flow paths are referred to as second flow paths 24. In this embodiment, as shown... Figure 2 As shown, four second flow paths (second flow paths 24a to 24b) are formed between the first manifold 6 and the second manifold 11.

[0045] Furthermore, in this embodiment, the first manifold 6 is positioned near the mold 10, and as described above, the length direction of the first manifold 6 is parallel to the width direction of the mold 10. Consequently, the lengths of the pipes forming each second flow path 24 are relatively short, and the lengths of each second flow path 24 are equal. Specifically, the length of each pipe connecting the first manifold 6 and the mold 10 is 30mm to 300mm. Therefore, the pressure losses in the pipes forming each second flow path 24 are approximately equal.

[0046] Here, an adjustment section 30 for adjusting the flow rate of the coating liquid 3 flowing through at least one second flow path 24 and outside the mold 10 is provided. In this embodiment, as... Figure 2 As shown, regulating sections 30 (regulating sections 30a to 30d) are provided in all the second flow paths 24 (second flow paths 24a to 24b). By using these regulating sections 30a to 30d to regulate the flow rate of the coating liquid 3 in the outlets 26a to 26d, which are the terminals of the second flow paths 24a to 24d, the distribution of the inflow of the coating liquid 3 into the second manifold 11 in the width direction TD is adjusted. As a result, the distribution of the amount of coating liquid ejected from the nozzle 18 in the width direction TD is adjusted.

[0047] In this embodiment, the regulating unit 30 is a valve whose opening degree can be adjusted by electrical control, and it has the function of adjusting the flow rate of the coating liquid 3 passing through it. It should be noted that the regulating unit 30 can also adjust the pressure of the coating liquid 3 passing through it.

[0048] The coating apparatus 1 is equipped with a sensor 36 (see reference) for measuring the film thickness of the coating liquid 3 coated on the substrate 2. Figure 1 Multiple sensors 36 can also be arranged along the width direction. The sensors 36 are non-contact and can measure the film thickness of the coating liquid 3 on the substrate 2 at multiple points along the width direction, or measure the film thickness of the coating liquid 3 on the substrate 2 along the entire length of the width direction TD. The measurement results are output to the control device (computer) 37 provided in the coating apparatus 1. The control device 37 performs feedback control based on the measurement results from the sensors 36, independently adjusting the opening of the adjustment sections 30a to 30d. That is, based on the measurement results of the film thickness of the coating liquid 3, the control device 37 outputs control signals to the adjustment sections 30a to 30d respectively, adjusting the opening of each of the adjustment sections 30a to 30d.

[0049] Furthermore, in this embodiment, an intermittent supply section 40 for intermittently supplying the coating liquid 3 is provided between the tank 22 and the first flow path 21, that is, on the supply path for supplying the coating liquid 3 to the first flow path 21, such as... Figure 1As shown, the coating liquid 3 can be intermittently applied to the substrate 2. Specifically, the intermittent supply unit 40 has a supply valve 41, and the position of the valve body 42 disposed inside the supply valve 41 changes according to the movement of the shaft based on the cylinder 43, thereby switching between two states: an open state for forming the flow path of the coating liquid 3 and a closed state for cutting off the flow path of the coating liquid 3. Here, when the supply valve 41 is in the open state, the coating liquid 3 is sprayed from the nozzle 18 of the mold 10 to start coating; when the supply valve 41 is in the closed state, the supply of the coating liquid 3 to the mold 10 is cut off, interrupting the coating of the coating liquid 3 on the substrate 2. That is, by controlling the movement of the cylinder 43 to control the position of the valve body 42, the open and closed states of the supply valve 41 are repeated, thereby intermittently forming a coating film on the substrate 2.

[0050] Furthermore, the intermittent supply unit 40 has a return valve 44 in front of the supply valve 41. When the valve body 42 of the supply valve 41 is closed and the supply of coating liquid 3 to the mold 10 is interrupted, the valve body 45 of the return valve 44 is opened, thereby recovering the coating liquid 3 back to the tank 22. Conversely, when the valve body 42 of the supply valve 41 is open and coating liquid 3 is supplied to the mold 10, the valve body 45 of the return valve 44 is closed. The valve body 45 is actuated by a cylinder 46.

[0051] The effects of the coating apparatus 1 having the above configuration are shown below.

[0052] The coating apparatus 1 has adjustment sections 30 on a plurality of second flow paths 24 arranged and connected along the length direction of the second manifold 11 (the width direction of the mold 10). Thus, for example, feedback control based on measurement results from the sensor 36 is performed on each adjustment section 30 to adjust the flow rate of the coating liquid 3 flowing into the second manifold 11 from each inlet 27. This allows for high-precision adjustment, enabling the coating liquid 3 to be precisely ejected from the slits 12 of the mold 10 to form a coating of a predetermined shape (e.g., uniform film thickness) on the substrate 2 in the width direction. Furthermore, in this coating apparatus 1, since the coating liquid 3 does not discharge and return to the tank 22, even when the coating liquid 3 is a slurry used for manufacturing battery plates, the separated coating liquid 3 will not mix into the tank 22, enabling the formation of a high-quality coating film on the substrate 2. Furthermore, unlike the method of discharging a portion of the coating liquid 3 from the mold 10, the flow rate in each of the second flow paths 24 can be adjusted without changing the total flow rate of the coating liquid 3 supplied from all the second flow paths 24 to the second manifold 11, thus enabling the coating liquid 3 of a specified flow rate to be stably coated on the substrate 2.

[0053] Furthermore, when the first flow path 21 branches into multiple second flow paths 24, the first manifold 6 is configured so that once the coating liquid 3 accumulates in the first manifold 6, it flows into the second flow path 24. This allows the coating liquid 3 to be delivered to each second flow path 24 at approximately equal flow rates via each outlet 26, maximizing its performance even for the regulating section 30, which is not robust to the valve opening range. As a result, in order to form a coating film of a predetermined shape on the substrate 2 in the width direction, the adjustment can be made with higher precision, so that the coating liquid 3 can be sprayed out from the slit 12 of the mold 10 with high precision.

[0054] Furthermore, by arranging the first manifold 6 and the second manifold 11 in the vicinity of the mold 10 with their lengths aligned in the same direction, and with the outlet 26, the connection between the first manifold 6 and the second flow path 24, arranged along the length of the first manifold 6, it is easy to design that the lengths of the multiple second flow paths 24 are equal. By making the lengths of the multiple second flow paths 24 equal, the pressure loss in the piping forming the second flow path 24 becomes uniform, and the adjustment of the flow rate distribution of the coating liquid 3 flowing into the second manifold 11 in the width direction becomes easier.

[0055] Furthermore, by having an intermittent supply section 40 that intermittently supplies the coating liquid 3 in the supply path that supplies the coating liquid 3 to the first flow path 21, a coating film with uniform thickness in the width direction can be intermittently coated onto the substrate 2.

[0056] Here, the adjustment unit 30 is not limited to electrical control; its opening can also be adjusted manually. When using the manual adjustment unit 30, the operator can determine the optimal opening of each adjustment unit 30 based on the measurement results of the coating thickness on the substrate 2 by the sensor 36, and manually adjust the opening of the adjustment unit 30.

[0057] Next, use Figure 4 (a) and (b) describe a coating apparatus 1, particularly a mold 10, according to another embodiment of the present invention.

[0058] exist Figure 4 In the mold 10 shown in (a) and (b), the first manifold 6 is also formed inside the mold 10, and the second flow path 24 connecting the first manifold 6 and the second manifold 11 is also formed inside the mold 10.

[0059] In the case of such mold 10, with Figures 1 to 3 Compared to the mold 10 shown, the structure is more complex, but the flow path connected to the mold 10 is only the first flow path 21, which can prevent the piping structure up to the mold 10 from becoming more complicated.

[0060] exist Figure 4In the mold 10 shown in (a), the adjustment unit 30 is electrically controlled and disposed inside the mold 10. Moreover, the electrical wiring 31 connected to the adjustment unit 30 is led out to the outside of the mold 10 and electrically connected to the control device 37 (not shown). Thus, the opening degree of the valve of the adjustment unit 30 disposed inside the mold 10 can be electrically controlled from the outside of the mold 10.

[0061] On the other hand, Figure 4 In the mold 10 shown in (b), the adjustment unit 30 has a displacement unit 32 that changes the opening area of ​​the second flow path 24 as the flow rate of the coating liquid changes. The displacement unit 32 is located in the middle of the second flow path 24, and may be, for example, a needle valve or a handle of a valve whose opening degree can be adjusted manually.

[0062] The above coating device can be used to apply a coating film with good quality and uniform thickness.

[0063] Here, the coating apparatus of the present invention is not limited to the manner described above, and other methods may also be used within the scope of the present invention. For example, the lengths of the plurality of second flow paths may not necessarily be uniform, and the length direction of the first manifold disposed outside the mold may not necessarily be consistent with the length direction of the mold and the second manifold.

[0064] Furthermore, in the above description, an adjustment unit is provided in the middle of all the second flow paths, but it is also possible to omit the adjustment unit in some of the second flow paths. For example, it is also possible to omit the adjustment unit in one of the multiple second flow paths.

[0065] Furthermore, the supply valve 41 and return valve 44 forming the intermittent supply section 40 are not limited to air drive, but may also be motor driven, for example.

[0066] Industrial availability

[0067] This invention can be widely applied to coating apparatuses for applying coating liquid to substrates.

[0068] Marker description

[0069] 1 Coating apparatus

[0070] 2 Substrate

[0071] 3 Coating liquid

[0072] 5 rollers

[0073] 6 First manifold

[0074] 7 manifold components

[0075] 10 molds

[0076] 11 Second manifold

[0077] 12 gaps

[0078] 18 spray nozzles

[0079] 20 supply units

[0080] 21First flow path

[0081] 22 cans

[0082] 23 pumps

[0083] 24 Second Flow Path

[0084] 25 Flow Inlets

[0085] 26 outlets

[0086] 26a Outlet

[0087] 26b Outlet

[0088] 26c Outlet

[0089] 26d Outlet

[0090] 27 Flow Inlets

[0091] 27a Inlet

[0092] 27b Inlet

[0093] 27c Flow Inlet

[0094] 27d inlet

[0095] 28 outlets

[0096] 30 Adjustment Section

[0097] 31 Electrical Wiring

[0098] 32 displacement section

[0099] 36 sensors

[0100] 37 Control Device

[0101] 40 Intermittent Supply Department

[0102] 41 Supply Valve

[0103] 42 Valve Body

[0104] 43 cylinders

[0105] 44 reflux valve

[0106] 45 valve body

[0107] 46 cylinders

Claims

1. A coating apparatus for spraying a coating liquid from slits provided in a mold to form a coating film on a substrate, wherein the slits are elongated in one direction, characterized in that, The coating apparatus includes: The first flow path is the flow path that supplies the coating liquid to the mold; A first manifold, which is connected to the first flow path, accumulates the coating liquid flowing in from the first flow path; Multiple second flow paths are connected to the first manifold; The second manifold, which is connected to the second flow path and the gap, is elongated in one direction and accumulates the coating liquid flowing in from the second flow path; as well as An adjustment unit, disposed midway through at least one of the second flow paths, adjusts the flow rate of the coating liquid flowing through the second flow path. The second manifold is divided into multiple parts in one direction.

2. The coating apparatus according to claim 1, characterized in that, The first manifold and the adjustment section are located outside the mold.

3. The coating apparatus according to claim 1, characterized in that, The first manifold and at least the flow path portion of the coating liquid of the regulating section are disposed inside the mold.

4. The coating apparatus according to any one of claims 1 to 3, characterized in that, The lengths of the multiple second flow paths are equal to each other.

5. The coating apparatus according to any one of claims 1 to 3, characterized in that, The first manifold is elongated in one direction, and the connection portions of the multiple second flow paths to the first manifold are arranged along the length direction of the first manifold.

6. The coating apparatus according to claim 4, characterized in that, The first manifold is elongated in one direction, and the connection portions of the multiple second flow paths to the first manifold are arranged along the length direction of the first manifold.

7. The coating apparatus according to any one of claims 1 to 3, characterized in that, The supply path for supplying coating liquid to the first flow path has an intermittent supply section for intermittently supplying coating liquid.

8. The coating apparatus according to claim 4, characterized in that, The supply path for supplying coating liquid to the first flow path has an intermittent supply section for intermittently supplying coating liquid.

9. The coating apparatus according to claim 5, characterized in that, The supply path for supplying coating liquid to the first flow path has an intermittent supply section for intermittently supplying coating liquid.

10. The coating apparatus according to claim 6, characterized in that, The supply path for supplying coating liquid to the first flow path has an intermittent supply section for intermittently supplying coating liquid.

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