Double-sided coating device

Abstract

This both-sides coating apparatus 1 comprises: a conveyance mechanism 2 which consecutively conveys a base material 12 that has a first surface 12a and a second surface 12b; a first die 4 which applies a first coating material 18 to the first surface 12a; a second die 6 which applies a second coating material 20 to the second surface 12b; and a supporting part 8 which is fixed to an external surface of the second die 6 and which, by means of gas transfer that includes gas discharge and gas suction, supports the base material 12 at a target coating height H1.

Description

[Technical Field]

[0001] The present disclosure relates to a double-sided coating device. [Background technology]

[0002] Conventionally, for example, in the field of manufacturing lithium-ion secondary batteries, a double-sided coating device has been known that applies a coating material containing an electrode active material to both sides of a substrate such as a metal foil while the substrate is transported using a roll-to-roll method to form an electrode active material layer. A known double-sided coating device of this type is configured to first apply a first coating material to a first side of the substrate and dry it, and then apply a second coating material to a second side of the substrate and dry it. However, this configuration requires two drying ovens, which increases the overall length, equipment costs, and installation space.

[0003] In response to this, a double-sided coating device has been proposed that first applies a first coating material to a first side of a substrate, then applies a second coating material to a second side, and then dries the first and second coating materials at the same time. In such a double-sided coating device, the first coating material can be applied to the first side while the second side is supported by a backup roll. However, when applying the second coating material to the second side, the backup roll cannot support the first side, which has the undried first coating material applied to it. Therefore, the second coating material must be applied to the second side while the substrate is suspended in the air.

[0004] When the substrate is suspended in the air, it is difficult to maintain the position and flatness of the substrate. This makes it easy for the thickness of the second coating material to become uneven. In response to this, for example, Patent Document 1 proposes a thin-film coating device in which the tip of the nozzle that ejects the coating material comes into contact with the substrate being transported, and the coating material is applied while the nozzle supports the substrate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-143388 Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional thin-film coating device described above, the substrate is supported by the nozzle, which reduces deflection and vibration of the substrate. This allows for the formation of a coating film with a more uniform thickness. However, there is a risk that particles will be generated due to wear of the substrate and nozzle when the substrate and nozzle rub against each other during transport. It is desirable to avoid the generation of particles, as this can lead to a decrease in product quality.

[0007] The present disclosure has been made in view of these circumstances, and its purpose is to provide a technology that suppresses deflection and vibration of a substrate while suppressing particle generation in a double-side coating device. [Means for solving the problem]

[0008] One aspect of the present disclosure is a double-sided coating device that includes a conveying mechanism that continuously conveys a long substrate having a first side and a second side opposite to the first side, a first die that applies a first coating material to the first side, a second die that is located downstream of the first die in the substrate conveyance direction and applies a second coating material to the second side, and a support unit that is fixed to the outer surface of the second die and that supports the substrate at a target coating height where the second side is spaced a predetermined distance from the second die by transferring gas to the second side, including ejecting gas onto the second side and suctioning gas between the second side and the second die.

[0009] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to suppress deflection and vibration of a substrate while suppressing particle generation in a double-side coating device. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view schematically showing a double-side coating device according to an embodiment. [Figure 2] FIG. 2 is an enlarged side view showing a portion of the double-side coating device. [Figure 3] FIG. 2 is a plan view of a second die. [Figure 4] FIG. 10 is a cross-sectional view of a second die provided in a double-side coating device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present disclosure will be described below with reference to preferred embodiments and drawings. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0013] FIG. 1 is a side view schematically illustrating a double-sided coating apparatus 1 according to an embodiment. FIG. 2 is an enlarged side view of a portion of the double-sided coating apparatus 1. The first die 4 and the second die 6 are illustrated in cross section. The double-sided coating apparatus 1 includes a conveying mechanism 2, a first die 4, a second die 6, a support unit 8, and a drying oven 10. The first die 4, the second die 6, and the drying oven 10 are arranged in the listed order from the upstream side in the conveying direction A of the substrate 12 by the conveying mechanism 2. The first die 4, the second die 6, and the drying oven 10 are arranged in a roughly horizontal direction. The support unit 8 is fixed to the outer surface of the second die 6. Therefore, the second die 6 and the support unit 8 are located downstream of the first die 4 in the conveying direction A.

[0014] The conveying mechanism 2 continuously conveys the long, thin-film substrate 12. The substrate 12 is in the form of a roll, and is pulled out from the roll by the conveying mechanism 2. The substrate 12 passes through the first die 4, the second die 6, and the drying oven 10 before being wound onto a take-up reel (not shown). The conveying mechanism 2 has a roll 14 and a retraction section 16. The roll 14 is located upstream of the second die 6 in the conveying direction A of the substrate 12, and conveys the substrate 12 while supporting it with its peripheral surface. In this embodiment, the roll 14 is disposed so that its peripheral surface faces the discharge opening of the first die 4 with a predetermined gap (coating gap) between them, and functions as a backup roll.

[0015] The substrate 12 has a first surface 12a and a second surface 12b opposite to the first surface 12a. The roll 14 conveys the substrate 12 while supporting the second surface 12b with its circumferential surface, and passes it through the gap between the first die 4 and the roll 14. The first die 4 applies a first coating material 18 to the first surface 12a of the substrate 12 that passes through the gap between the first die 4 and the roll 14. As an example, the first die 4 is positioned so that its discharge outlet faces horizontally, and is aligned horizontally with the roll 14.

[0016] The double-sided coating apparatus 1 of this embodiment is used to manufacture electrode plates for secondary batteries. The electrode plate for secondary batteries is a sheet-like electrode material obtained by applying electrode slurry to a current collector and then drying the applied material. Therefore, in this embodiment, the substrate 12 is the current collector of the secondary battery, and the first coating material 18 is the electrode slurry for the secondary battery. The second coating material 20 discharged from the second die 6 is also the electrode slurry for the secondary battery. The current collector is, for example, a metal foil. The electrode slurry is, for example, a mixture of a positive electrode active material or a negative electrode active material and a solvent. In a typical lithium-ion secondary battery, a positive electrode plate is manufactured by applying a slurry containing a positive electrode active material such as lithium cobalt oxide or lithium iron phosphate to aluminum foil. A negative electrode plate is manufactured by applying a slurry containing a negative electrode active material such as graphite to copper foil. The first coating material 18 and the second coating material 20 may be the same or different coating materials. The double-sided coating apparatus 1 can also be used to manufacture products other than electrode plates.

[0017] The roll 14 feeds the substrate 12 downstream in the conveyance direction A, with the first surface 12a, coated with the first coating material 18, facing upward and the second surface 12b, uncoated with the second coating material 20, facing downward. The substrate 12 is fed from the roll 14 in a substantially horizontal direction. The upper end of the circumferential surface of the roll 14 is positioned higher than the target coating height H1 of the substrate 12. Furthermore, the height of the position 14a at which the substrate 12 separates from the circumferential surface of the roll 14, i.e., the delivery height H2, is higher than the target coating height H1. The target coating height H1 is the height at which the second surface 12b is separated from the second die 6 by a predetermined amount. By positioning the substrate 12 at the target coating height H1, a predetermined coating gap G is formed between the discharge opening of the second die 6 and the second surface 12b. The delivery height H2 is approximately the same height as the upper end of the peripheral surface of the roll 14, but strictly speaking, the substrate 12 is pulled downward by the retraction portion 16, so that the delivery height H2 is slightly lower than the upper end of the peripheral surface.

[0018] A retraction section 16 is disposed between the roll 14 and the second die 6 in the conveying direction A. The substrate 12 delivered from the roll 14 is retracted by the retraction section 16 so as to approach the target coating height H1. The retraction section 16 has a suction section 22 that sucks in gas such as atmospheric gas (e.g., air). The retraction section 16 can retract the substrate 12 downward by using the suction section 22 to suck in the atmospheric gas present between the retraction section 16 and the second surface 12b. The suction section 22 can be configured with a known suction roller, suction plate, suction-type air knife, or the like. The height of the suction section 22 is mechanically adjustable and is adjusted to an optimum height depending on the thickness and mass of the substrate 12.

[0019] The retraction unit 16 of this embodiment has multiple suction units 22 aligned in the conveying direction A. In FIGS. 1 and 2, two suction units 22 are aligned in the conveying direction A. The multiple suction units 22 are aligned such that their installation heights decrease toward the downstream side in the conveying direction A. In other words, the suction units 22 located downstream in the conveying direction A are positioned lower than the suction units 22 located upstream in the conveying direction A, i.e., closer to the target coating height H1. The substrate 12 is retracted by the retraction unit 16 to the target coating height H1 and then sent downstream in the conveying direction A. Note that three or more suction units 22 may be aligned in the conveying direction A, or there may be only one suction unit 22. If the delivery height H2 of the roll 14 is approximately equal to the target coating height H1, the retraction unit 16 may be omitted.

[0020] The second die 6 is disposed downstream of the retraction section 16 in the conveying direction A. The second die 6 applies a second coating material 20 to the second surface 12b of the substrate 12, which is suspended in the air. At least the area of ​​the substrate 12 that faces the second die 6 is suspended in the air. As an example, the second die 6 is oriented so that the outlet 50 faces vertically upward, and applies the second coating material 20 to the second surface 12b that faces vertically downward. In addition, a support section 8 is fixed to the outer surface of the second die 6.

[0021] The support unit 8 supports the substrate 12 at the target coating height H1 by transferring gas to the second surface 12b. Transferring gas to the second surface 12b includes both ejecting gas onto the second surface 12b and suctioning gas (i.e., atmospheric gas) present between the support unit 8 and the second surface 12b. The gas ejected from the support unit 8 is, for example, atmospheric gas. In other words, the support unit 8 of this embodiment supports the substrate 12 at the target coating height H1 by combining ejecting and suctioning gas.

[0022] As an example, the second die 6 has a first body 24, a second body 26, a manifold 38, a paint flow path 48, and a discharge port 50. The first body 24 and the second body 26 are elongated in the width direction B of the substrate 12, which is perpendicular to the conveying direction A. The first body 24 is disposed downstream of the second body 26 in the conveying direction A. The first body 24 in this embodiment has a tapered surface 24a that slopes toward the second body 26 as it approaches the second surface 12b. The second body 26 also has a tapered surface 26a that slopes toward the first body 24 as it approaches the second surface 12b. The tapered surfaces 24a, 26a are disposed at the end of the second die 6 on the second surface 12b side.

[0023] Between the first body 24 and the second body 26, there is disposed a discharge port 50 that opens toward the second surface 12b, and a paint flow path 48 that communicates with the discharge port 50. For example, a sheet-like shim 52 is interposed between the first body 24 and the second body 26. This forms a gap between the first body 24 and the second body 26 that is equal to the thickness of the shim 52. This gap forms the paint flow path 48. The open end of this gap that faces the second surface 12b forms the discharge port 50. The first body 24 has a recess that is long in the width direction B on the surface facing the second body 26. This recess forms a manifold 38. The manifold 38 may be provided in the second body 26.

[0024] A supply pipe for the second coating material 20 is connected to the manifold 38, and the second coating material 20 is supplied from outside. The end of the coating material flow path 48 opposite the discharge port 50 is connected to the manifold 38. The second coating material 20 supplied to the manifold 38 flows through the coating material flow path 48 and is discharged from the discharge port 50 onto the second surface 12b.

[0025] The support portion 8 is fixed to the outer surface of the second body 26 facing upstream in the conveying direction A. Therefore, the support portion 8 is located upstream of the discharge port 50 in the conveying direction A. In this embodiment, the support portion 8 is fixed to the tapered surface 26a. The support portion 8 may be fixed to the outer surface of the first body 24 and located downstream of the discharge port 50 in the conveying direction A. In this case, the support portion 8 is fixed to, for example, the tapered surface 24a. Preferably, the tip of the support portion 8 on the second surface 12b side is arranged so as to be flush with the discharge port 50. Therefore, the support portion 8 and the discharge port 50 are spaced the same distance from the second surface 12b.

[0026] The support part 8 of the present embodiment includes, as an example, a porous material 40, a pipe 42, and an air supply / suction device 44. The porous material 40 is fixed to the tapered surface 26a, and the tip on the second surface 12b side faces the second surface 12b. The porous material 40 may be fixed to the second main body 26 with a fixing device such as a bracket, or may be adhered to the second main body 26 with an adhesive. The tip of the porous material 40 on the second surface 12b side is substantially flush with the discharge port 50.

[0027] FIG. 3 is a plan view of the second die 6. In FIG. 3, an x ​​symbol surrounded by a circle represents the flow of sucked gas, and a · symbol surrounded by a circle represents the flow of discharged gas. As shown in FIG. 3, the porous material 40 of this embodiment is partitioned into multiple regions with different gas transfer rates (discharge rate and suction rate). For example, each region is airtightly partitioned by a partition plate. Hereinafter, the region from which gas is discharged is referred to as a discharge region 40a, and the region from which gas is sucked is referred to as a suction region 40b. The porous material 40 of this embodiment has multiple discharge regions 40a and multiple suction regions 40b. The multiple discharge regions 40a have different gas discharge rates at least in part. The multiple suction regions 40b have different gas suction rates at least in part.

[0028] The multiple regions are aligned in the width direction B of the substrate 12. In the example shown in FIG. 3, the multiple discharge regions 40a and the multiple suction regions 40b are alternately arranged in the width direction B. As an example, the multiple discharge regions 40a have a smaller amount of gas discharged toward the outside in the width direction B, and the multiple suction regions 40b have a larger amount of gas suctioned toward the outside in the width direction B. This allows the amount of gas drawn in to be increased toward the outside in the width direction B. Alternatively, the multiple discharge regions 40a have a larger amount of gas discharged toward the outside in the width direction B, and the multiple suction regions 40b have a smaller amount of gas suctioned toward the outside in the width direction B. This allows the amount of extrusion of the substrate 12 to be increased toward the outside in the width direction B.

[0029] The plurality of ejection regions 40a may have the same ejection amount, and the plurality of suction regions 40b may have different suction amounts. Alternatively, the plurality of ejection regions 40a may have different ejection amounts, and the plurality of suction regions 40b may have the same suction amount. Alternatively, the plurality of regions may be arranged in the transport direction A. Alternatively, the support unit 8 may have ejection regions 40a that are not divided into multiple regions, and have a uniform ejection amount. Alternatively, the support unit 8 may have suction regions 40b that are not divided into multiple regions, and have a uniform suction amount.

[0030] As shown in FIG. 2, an air supply / suction device 44 is connected to the porous material 40 via a pipe 42. The air supply / suction device 44 is composed of, for example, a compressor that discharges gas and a vacuum pump that sucks gas. A compressor is connected to each discharge region 40a via a pipe 42, and a vacuum pump is connected to each suction region 40b via a pipe 42. Different air supply volumes in each discharge region 40a may be achieved by connecting different compressors to each discharge region 40a, or by varying the porosity, etc., of each discharge region 40a. Similarly, different air suction volumes in each suction region 40b may be achieved by connecting different vacuum pumps to each suction region 40b, or by varying the porosity, etc. of each suction region 40b.

[0031] By driving the air supply / suction device 44, gas is blown from each discharge region 40a onto the second surface 12b, and gas present between the second die 6 and the second surface 12b is sucked through each suction region 40b. The positive pressure generated by the gas being ejected from each discharge region 40a and the negative pressure generated by the gas being sucked through each suction region 40b balance, supporting the substrate 12 in a suspended state at the target coating height H1. This allows the second coating material 20 to be applied to the second surface 12b while forming a desired coating gap G between the substrate 12 and the second die 6 and while maintaining the flatness of the substrate 12 with high precision. The support unit 8 may have any other known structure capable of discharging and suctioning gas.

[0032] As shown in FIG. 1 , a drying oven 10 is disposed downstream of the second die 6 in the conveying direction A. Gas injection nozzles 46 are provided at the top and bottom of the drying oven 10 to eject gas (e.g., hot air) for drying the first coating material 18 and the second coating material 20. The substrate 12, whose first surface 12a has been coated with the first coating material 18 and whose second surface 12b has been coated with the second coating material 20, is transported through the drying oven 10 while being suspended by the gas ejected from the gas injection nozzles 46. The substrate 12, whose first coating material 18 and second coating material 20 have been dried while passing through the drying oven 10, is taken up by a take-up reel after leaving the drying oven 10.

[0033] As described above, the double-side coating device 1 according to this embodiment includes a conveying mechanism 2, a first die 4, a second die 6, and a support unit 8. The conveying mechanism 2 continuously conveys the substrate 12 having a first surface 12a and a second surface 12b. The first die 4 applies a first coating material 18 to the first surface 12a. The second die 6 is located downstream of the first die 4 in the conveying direction A and applies a second coating material 20 to the second surface 12b. The support unit 8 is located downstream of the first die 4 in the conveying direction A and supports the substrate 12 at a target coating height H1 by gas transfer, including gas ejection onto the second surface 12b and gas suction between the support unit 8 and the second surface 12b. The support unit 8 (porous material 40 in this embodiment) is fixed to the outer surface of the second die 6.

[0034] One end of the substrate 12 is supported by the roll 14, and the other end is supported by a transport roll or take-up roll (not shown) downstream of the drying oven 10. This allows the portion of the substrate 12 between the two rolls to be suspended in midair, preventing the substrate 12 from contacting the second die 6. However, the suspended substrate 12 is subject to considerable bending due to its own weight. When the substrate 12 is sagged, vibrations of the substrate 12 caused by the rotation of the roll 14 or the hot air from the drying oven 10 are more likely to propagate within the substrate 12, making it difficult to stably maintain the position of the substrate 12. Furthermore, distortion occurs in the substrate 12, reducing its flatness.

[0035] In contrast, in the double-sided coating apparatus 1 of this embodiment, the support unit 8 both discharges and suctions gas onto the substrate 12, thereby supporting the substrate 12 at the target coating height H1 while suspending it in mid-air. By combining gas discharge and suction, the height of the substrate 12 can be more accurately adjusted to the target coating height H1 than when only one of these methods is used. Furthermore, the support unit 8 is fixed to the outer surface of the second die 6. Therefore, the substrate 12 can be supported at the target coating height H1 in a position extremely close to the discharge port 50 of the second coating material 20. This suppresses particle generation and also suppresses distortion and vibration of the substrate 12 at the discharge position of the second coating material 20. Therefore, the double-sided coating apparatus 1 of this embodiment can apply the second coating material 20 to the second surface 12b while maintaining the position and flatness of the substrate 12 with high precision. As a result, a coating film of the second coating material 20 with higher precision and quality can be formed.

[0036] Furthermore, the support unit 8 is divided into multiple regions with different gas transfer rates. In this embodiment, the porous material 40 of the support unit 8 is divided into multiple discharge regions 40a and multiple suction regions 40b. At least some of the multiple discharge regions 40a have different gas discharge rates. At least some of the multiple suction regions 40b have different gas suction rates. This allows the support unit 8 to adjust the amount of extrusion and retraction of the substrate 12 according to the amount of deflection and distortion at each location on the substrate 12. As a result, the flatness of the substrate 12 can be further improved. In this embodiment, multiple regions are aligned in the width direction B of the substrate 12. The substrate 12 tends to bend more easily at both ends in the width direction B than at the center. Therefore, by making the amount of extrusion and retraction of the substrate 12 adjustable in the width direction B, the flatness of the substrate 12 can be further improved.

[0037] Furthermore, the tip of the support part 8 on the second surface 12b side is arranged so as to be flush with the discharge port 50. In this embodiment, the tip of the porous material 40 of the support part 8 is flush with the discharge port 50. This makes it possible to bring the support part 8 as close as possible to the second surface 12b, making it easier to support the substrate 12, and also makes it easier to prevent the support part 8 from coming into contact with the second surface 12b.

[0038] In this embodiment, the second die 6 is provided with the support portion 8, but the first die 4 may also be provided with the support portion 8. In this case, the first paint 18 is applied to the first surface 12a from the first die 4 while the substrate 12 is suspended in the air.

[0039] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object.

[0040] (Variation) FIG. 4 is a cross-sectional view of the second die 6 included in the double-side coating apparatus 1 according to a modified example. The support unit 8 of this modified example transfers gas to the second surface 12b on both the upstream and downstream sides of the discharge port 50 in the conveying direction A. As an example, the support unit 8 has two combinations of porous materials 40, piping 42, and air supply / suction devices 44. One porous material 40 is fixed to the tapered surface 26a of the second body 26, and the other porous material 40 is fixed to the tapered surface 24a of the first body 24. Each porous material 40 is connected to a separate air supply / suction device 44 via the piping 42. Gas is then discharged and sucked from each porous material 40 to support the substrate 12. The two porous materials 40 may be connected to a common air supply / suction device 44.

[0041] In this way, by supporting the substrate 12 on both sides of the discharge port 50, it is possible to maintain with higher precision the position and flatness of the portion of the substrate 12 facing the discharge port 50. Furthermore, by supporting the substrate 12 downstream of the discharge port 50 in the conveying direction A, it is possible to prevent vibrations of the substrate 12 caused by exposure to hot air in the drying furnace 10 from propagating to the portion of the substrate 12 facing the discharge port 50. As a result, it is possible to form a coating film of the second coating material 20 having a more uniform film thickness.

[0042] The embodiments may be specified by the following items. [Item 1] a conveying mechanism (2) for continuously conveying a long substrate (12) having a first surface (12a) and a second surface (12b) opposite to the first surface (12a); a first die (4) for applying a first coating material (18) to the first surface (12a); a second die (6) positioned downstream of the first die (4) in the conveying direction (A) of the substrate (12) and configured to apply a second coating material (20) to the second surface (12b); a support part (8) fixed to the outer surface of the second die (6) and supporting the substrate (12) at a target coating height (H1) at which the second surface (12b) is spaced a predetermined distance from the second die (6) by transferring gas to the second surface (12b) including discharging gas to the second surface (12b) and suctioning gas present between the second surface (12b) and the second surface (12b); Double-sided coating device (1). [Item 2] The support portion (8) transfers the gas on both the upstream side and the downstream side of the discharge port of the second coating material (20) in the conveying direction (A). Item 1. The double-sided coating device (1) according to item 1. [Item 3] The support portion (8) is divided into a plurality of regions (40a, 40b) having different gas transfer rates. Item 1 or 2. The double-side coating device (1). [Item 4] The multiple regions (40a, 40b) are aligned in the width direction (B) of the substrate (12). Item 3. The double-sided coating device (1) according to item 3. [Item 5] The tip of the support part (8) on the second surface (12b) side is arranged so as to be flush with the discharge port (50) of the second paint (20). A double-side coating device (1) according to any one of items 1 to 4. [Item 6] The substrate (12) is a current collector of a secondary battery, The first paint (18) and the second paint (20) are electrode slurries for a secondary battery. A double-side coating device (1) according to any one of items 1 to 5. [Industrial Applicability]

[0043] The present disclosure can be used in double-sided coating devices. [Explanation of symbols]

[0044] 1 double-sided coating device, 2 conveying mechanism, 4 first die, 6 second die, 8 support part, 12 substrate, 12a first surface, 12b second surface, 18 first coating material, 20 second coating material, 50 discharge port, A conveying direction, B width direction, H1 target coating height.

Claims

1. a conveying mechanism that continuously conveys a long substrate having a first surface and a second surface opposite to the first surface; a first die for applying a first coating material to the first surface; a second die positioned downstream of the first die in the conveying direction of the substrate and configured to apply a second coating material to the second surface; a support portion fixed to an outer surface of the second die, which supports the substrate at a target coating height at which the second surface is spaced apart from the second die by a predetermined amount by transferring gas to the second surface, including discharging gas onto the second surface and suctioning gas present between the second surface and the second die. Double-sided coating device.

2. the support portion transfers the gas on both the upstream side and the downstream side of the discharge port of the second coating material in the conveying direction. The double-side coating device according to claim 1 .

3. The support portion is divided into a plurality of regions having different gas transfer rates. The double-side coating device according to claim 1 or 2.

4. The plurality of regions are aligned in the width direction of the base material. The double-side coating device according to claim 3.

5. a tip end of the support portion on the second surface side is disposed so as to be flush with the discharge port of the second paint; The double-side coating device according to any one of claims 1 to 4.

6. the substrate is a current collector of a secondary battery, The first paint and the second paint are electrode slurries for a secondary battery. The double-side coating device according to any one of claims 1 to 5.

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