Coating device

Abstract

To provide a coating device having excellent closing suppression property of a pressure reduction slit and excellent thickening suppression property of an end part in a width direction during film formation.SOLUTION: The coating device includes a slot die which has a jetting slit for jetting a coating liquid to a substrate to be transported, and a pressure reduction slit, in which the pressure reduction slit is positioned at an upstream side of the jetting slit from the same position of the slot die in a substrate transport direction, and at an outside in a width direction of the jetting slit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an application device. [Background technology]

[0002] 2. Description of the Related Art A technique for forming a film using a die provided with a slit for discharging a coating liquid and a slit for reducing pressure has been known. Patent Document 1 discloses a manufacturing method using a slot die, in which a coating bead is formed between a continuously running substrate and the tip of the slot die, and which has a reduced-pressure chamber including two side plates arranged opposite each other in the width direction of the substrate upstream of the slot die.

[0003] Patent Document 2 discloses a coating device having a decompression chamber that maintains a decompressed state upstream of the coating head in the direction of movement of the object to be coated, and is characterized in that the decompression chamber is divided into multiple chambers in the coating width direction, and the decompression degree of each of the multiple chambers can be adjusted independently.

[0004] Patent Document 3 discloses a coating device comprising a sheet conveying unit that conveys an electrode sheet, a coating nozzle that ejects an electrode material and an insulating material toward the electrode sheet being conveyed, and a gap adjustment unit that adjusts the distance between the electrode sheet being conveyed and the coating nozzle, wherein the coating nozzle has an electrode material ejection unit that ejects the electrode material and an insulating material ejection unit that ejects the insulating material, arranged side by side in a direction intersecting the conveyance direction of the electrode sheet, and the gap adjustment unit simultaneously adjusts the distance between the electrode sheet being conveyed and the electrode material ejection unit and the distance between the electrode sheet and the insulating material ejection unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-43321 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-155164 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-167337 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by one embodiment of the present disclosure is to provide a coating device that is excellent in preventing clogging of the decompression slit and in preventing thickening of the film at the width direction end portion during film formation. [Means for solving the problem]

[0007] The means for solving the above problems include the following aspects. <1> A coating device comprising a slot die having a discharge slit that discharges a coating liquid onto a substrate being transported, and a decompression slit, wherein the decompression slit is located upstream from the same position as the discharge slit in the substrate transport direction of the slot die, and outside the discharge slit in the width direction. <2> The opening of the decompression slit is 3 mm 2 Greater than <1> The coating device according to claim 1. <3> The pressure reducing slit is positioned 5 mm or more outside the widthwise end of the discharge slit. <1> or <2> The coating device according to claim 1. <4> For coating on substrates that are floated and transported <1> ~ <3> 10. The coating device according to claim 9, wherein the coating device is a coating apparatus having a coating layer. <5> For applying water-based coating fluid <1> ~ <4> 10. The coating device according to claim 9, wherein the coating device is a coating apparatus having a coating layer. <6> For forming electrode films in batteries <1> ~ <5> 10. The coating device according to claim 9, wherein the coating device is a coating apparatus having a coating layer. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a coating device that is excellent in preventing clogging of the decompression slit and in preventing thickening of the film at the width direction end portion during film formation. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic front view showing a coating surface of a slot die in an example of a conventional coating device. [Figure 2] FIG. 1 is a schematic perspective view showing a slot die in an example of a coating device according to the present disclosure. [Figure 3] FIG. 3 is a schematic front view showing a coating surface of a slot die 10 in the example of the coating device shown in FIG. 2. [Figure 4] 3 is a schematic cross-sectional view showing a cross-sectional structure of a discharge slit 12 in the example of the coating device shown in FIG. 2, as viewed from the side. FIG. [Figure 5] FIG. 2 is a schematic front view showing a coating surface of a slot die 10 in another example of a coating device according to the present disclosure. [Figure 6] FIG. 10 is a schematic perspective view showing a slot die 10 in yet another example of a coating device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments. The following embodiments may be modified as appropriate within the scope of the present disclosure.

[0011] When describing embodiments of the present disclosure with reference to the drawings, explanations of overlapping components and symbols in the drawings may be omitted. Components indicated by the same symbols in the drawings are the same components. The dimensional ratios in the drawings do not necessarily represent the actual dimensional ratios.

[0012] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the lower and upper limits, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with a value shown in the examples.

[0013] In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0014] In the present disclosure, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved.

[0015] In the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0016] In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

[0017] In this disclosure, "solid content" means components other than the solvent.

[0018] <Coating equipment> The coating device according to the present disclosure includes a slot die having a discharge slit that discharges a coating liquid onto a substrate being transported, and a decompression slit, and the decompression slit is located upstream from the same position as the discharge slit in the substrate transport direction of the slot die, and outside the discharge slit in the width direction. The coating device according to the present disclosure is preferably used for coating a water-based coating liquid. The coating device according to the present disclosure is preferably used for forming an electrode film of a battery.

[0019] Conventional coating devices equipped with a slot die having a pressure reduction means such as a pressure reduction slit have had problems such as the coating liquid being sucked into the pressure reduction slit, causing the pressure reduction slit to become clogged, and the film becoming thicker at the widthwise ends during film formation. The coating device according to the present disclosure includes a slot die having a discharge slit and a decompression slit, and the decompression slit is located upstream of the same position as the discharge slit in the substrate transport direction of the slot die and outside the discharge slit in the width direction, thereby reducing the possibility of contact between the coating liquid and the decompression slit and suppressing suction into the decompression slit, and also allowing the decompression by the decompression slit to function sufficiently at the width direction ends of the film to be formed, thereby suppressing the film from becoming thick at the width direction ends, and providing a coating device that is excellent in preventing blockage of the decompression slit and preventing the film from becoming thick at the width direction ends during film formation.

[0020] The coating device according to the present disclosure will be described in detail below.

[0021] FIG. 1 is a schematic front view showing a coating surface of a slot die in an example of a conventional coating device. The slot die 10 shown in FIG. 1 is provided with a discharge slit 12 and a decompression slit 14 below the discharge slit 12, and further below that, a waste liquid chamber 18 is provided. The decompression slit 14 is located upstream of the discharge slit 12 in the conveying direction, but as mentioned above, there are problems in that the decompression slit 14 sucks in the coating liquid (not shown) and becomes blocked, and there is also a problem in that the suction of the coating liquid prevents the decompression state from being achieved, resulting in a thick film at the widthwise end portion during film formation.

[0022] FIG. 2 is a schematic perspective view showing a slot die in an example of a coating device according to the present disclosure. The slot die 10 shown in Figure 2 is provided with a discharge slit 12 and two decompression slits 14 located upstream in the substrate conveyance direction (bottom to top direction in Figure 2) of the slot die 10 and outside the discharge slit 12 in the width direction. The slot die 10 is also composed of a slot die member 16. In this embodiment, the possibility of contact between the coating liquid (not shown) and the decompression slit 14 is reduced, and the coating liquid is prevented from being sucked into the decompression slit 14. Furthermore, the decompression by the decompression slit 14 functions sufficiently at the width direction ends of the film (not shown) to be formed, thereby preventing the film from becoming thicker at the width direction ends, and the decompression slit 14 is excellent in preventing clogging and preventing the film from becoming thicker at the width direction ends during film formation.

[0023] FIG. 3 is a schematic front view showing the coating surface of the slot die 10 in the example of the coating device shown in FIG. The slot die 10 shown in Figure 3, like that shown in Figure 2, is provided with a discharge slit 12 and two decompression slits 14 located upstream of the slot die 10 in the substrate conveying direction (bottom to top in Figure 3) and outside the discharge slit 12 in the width direction, and further below that, a waste liquid chamber 18 is provided. In addition, in Figure 3, L1 represents the width of the discharge slit 12, L2 represents the distance between the end of the discharge slit 12 and the end of the decompression slit 14 in the width direction of the discharge slit 12, and L3 represents the distance between the end of the discharge slit 12 and the end of the decompression slit 14 in the thickness direction of the discharge slit 12.

[0024] FIG. 4 is a schematic cross-sectional view showing a cross-sectional structure of the discharge slit 12 in the example of the coating device shown in FIG. 2, as viewed from the side. The slot die 10 shown in Fig. 4 has a discharge slit 12 penetrating through the center, and two decompression slits 14 located upstream in the substrate conveyance direction S1 of the slot die 10 and outside the discharge slit 12 in the width direction. Note that Fig. 4 shows the positions of the decompression slits 14 schematically. Furthermore, a waste liquid chamber 18 is provided at the bottom of the slot die 10 shown in Figure 4 to accommodate any coating liquid that has been discharged from the discharge slit and drips down the surface of the slot die member 16 without being applied to the substrate. The coating liquid (not shown) is discharged from the discharge slit 12 and applied to the substrate 20 being transported in the substrate transport direction S1. The direction of gravity in FIG. 4 is preferably opposite to the substrate transport direction S1.

[0025] FIG. 5 is a schematic front view showing a coating surface of a slot die 10 in another example of a coating device according to the present disclosure. The shape of the openings of the two decompression slots 14 is different from that of FIG. 3 and is circular.

[0026] FIG. 6 is a schematic perspective view showing a slot die 10 in yet another example of a coating device according to the present disclosure. The slot die 10 in Figure 6 has three discharge slits 12 and four decompression slits 14 located upstream of the slot die 10 in the substrate conveying direction and outside each discharge slit 12 in the width direction. Within the slot die 10, the three discharge slits 12 are connected by a liquid feed path 12P, and a coating liquid (not shown) is fed from a liquid feed means (not shown) in a liquid feed direction F1. Inside the slot die 10, the four decompression slits 14 are connected by a decompression path 14P, and air is sucked in a decompression direction R1 by a decompression means (not shown) such as a decompression pump, thereby reducing the pressure.

[0027] Furthermore, the shapes of the openings of the discharge slit 12 and the decompression slit 14 shown in Figures 2 to 4 and 6 are all rectangular, but it goes without saying that the opening of the decompression slit 14 may be circular as shown in Figure 5, and is not limited to these. The shape of the opening of the discharge slit 12 in the coating device according to the present disclosure can be selected appropriately according to the desired film shape. Furthermore, the above L1 can also be selected appropriately according to the desired film width. The thickness direction length of the opening of the discharge slit 12 in the coating device according to the present disclosure may be selected appropriately depending on the solid content of the coating liquid used and the desired film thickness, but is preferably 0.1 μm to 5 mm, more preferably 1 μm to 500 μm, and particularly preferably 10 μm to 200 μm. Furthermore, the number of discharge slits 12 in the coating device according to the present disclosure does not need to be one, but may be two or more, and can be appropriately selected as desired.

[0028] The shape of the opening of the decompression slit 14 in the coating device according to the present disclosure is not particularly limited, and may be any shape, such as a rectangle, a square, a polygon such as a pentagon or a hexagon, a circle, an ellipse, or a cross. Furthermore, the number of decompression slits 14 in the coating device according to the present disclosure does not have to be two, and may be one, or three or more, but it is preferable to have one on each of the outsides of both widthwise ends of the discharge slit 12, and when there is one discharge slit 12, it is particularly preferable to have one on each of the outsides of both widthwise ends of the discharge slit 12. The area of ​​the opening of the decompression slit 14 in the coating device according to the present disclosure is not particularly limited as long as it is possible to reduce the pressure. However, from the viewpoint of preventing the decompression slit from being blocked and preventing the film from becoming thick at the end in the width direction during film formation, it is preferable that the opening area be 1 mm 2 Preferably larger, 3 mm 2 Larger is preferable, 3mm 2 Over 50mm 2 It is more preferable that it is 5 mm or less. 2 More than 30mm 2 It is particularly preferred that: The width of the opening of the decompression slit 14 in the coating device according to the present disclosure is not particularly limited as long as it allows decompression, but is preferably 1 mm to 20 mm, and more preferably 2 mm to 10 mm. The thickness direction length of the opening of the decompression slit 14 in the coating device according to the present disclosure is not particularly limited as long as it allows decompression, but is preferably 0.1 mm to 10 mm, more preferably 0.2 mm to 8 mm, and particularly preferably 0.5 mm to 5 mm.

[0029] The decompression slit 14 in the coating device of the present disclosure may be located upstream of the slot die 10 in the substrate conveying direction S1, but from the standpoint of preventing blockage of the decompression slit and preventing the film from becoming thick at the widthwise ends during film formation, it is preferable that it be located at least 1 mm outside the widthwise end of the discharge slit 12, more preferably at least 2 mm outside the widthwise end of the discharge slit 12, even more preferably at least 5 mm outside the widthwise end of the discharge slit 12, and particularly preferably at a distance of 5 mm to 30 mm outside the widthwise end of the discharge slit 12. That is, the above L2, which indicates the distance between the end of the discharge slit 12 and the end of the decompression slit 14 in the width direction of the discharge slit 12, is 0 mm or more, and from the viewpoint of preventing blockage of the decompression slit and preventing the film from becoming thick at the width direction end during film formation, it is preferably 1 mm or more, more preferably 2 mm or more, even more preferably 5 mm or more, and particularly preferably 5 mm or more and 30 mm or less.

[0030] In the coating device of the present disclosure, the decompression slit 14 may be located upstream of the same position as the discharge slit 12 in the thickness direction of the discharge slit 12, in the conveying direction S1 of the substrate 20; however, from the viewpoint of preventing clogging of the decompression slit and preventing the film from becoming thick at the widthwise end during film formation, it is preferable to locate it upstream of the conveying direction S1 of the substrate 20, more preferably 1 mm or more upstream of the thicknesswise end of the discharge slit 12 in the conveying direction S1 of the substrate 20, even more preferably 2 mm or more upstream of the thicknesswise end of the discharge slit 12 in the conveying direction S1 of the substrate 20, and particularly preferably 2 mm to 30 mm upstream of the thicknesswise end of the discharge slit 12 in the conveying direction S1 of the substrate 20. That is, the above L3, which indicates the distance between the end of the discharge slit 12 and the end of the decompression slit in the thickness direction of the discharge slit 12, is 0 mm or more, and from the viewpoint of preventing blockage of the decompression slit and preventing the film from becoming thick at the widthwise end during film formation, it is preferably 1 mm or more, more preferably 2 mm or more, and particularly preferably 2 mm or more and 30 mm or less.

[0031] The material of the slot die member 16 is not particularly limited, and known materials such as stainless steel, cemented carbide, ceramic, glass, and resin can be used.

[0032] The coating device according to the present disclosure may or may not have a waste chamber 18. The waste liquid chamber 18 is a means for recovering the coating liquid that has not been applied, and a known one can be used. The waste liquid chamber 18 may have the shape of a receptacle as shown in FIG. 4, but is not particularly limited thereto, and the shape, size, installation position, etc. can be appropriately selected depending on the coating liquid to be used, the direction of gravity during coating, etc.

[0033] The substrate 20 is not particularly limited and may be appropriately selected as desired, and known materials may be used. Components of the substrate 20 include, for example, polymers and metals. Examples of polymers include polyethylene terephthalate, polyethylene naphthalate, and triacetyl cellulose. The substrate may contain one or more polymers. Examples of metals include iron, chromium, nickel, titanium, copper, aluminum, silver, and gold. The metal may be an alloy. Examples of alloys include stainless steel and invar. The substrate 20 may contain one or more metals. In one embodiment, the substrate 20 preferably contains a polymer, and more preferably contains at least one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and triacetyl cellulose. In one embodiment, the substrate 20 preferably contains a metal, and more preferably contains at least one selected from the group consisting of nickel, titanium, copper, aluminum, silver, and gold, even more preferably contains at least one selected from the group consisting of copper and aluminum, and particularly preferably contains aluminum.

[0034] The substrate 20 is preferably a film. Examples of the film include the above-mentioned polymer-containing film and the above-mentioned metal-containing film. Specific examples of the polymer-containing film include polyethylene terephthalate film, polyethylene naphthalate film, and triacetyl cellulose film. Specific examples of the metal-containing film include copper film and aluminum film.

[0035] The substrate 20 may have high thermal conductivity. Examples of substrates with high thermal conductivity include substrates with a thermal conductivity of 200 W / (m·K) or more. There is no upper limit to the thermal conductivity of the substrate 20. The thermal conductivity of the substrate 20 may be 500 W / (m·K) or less. The thermal conductivity of the substrate is measured using a laser flash method. First, the substrate 20 is cut out at three locations along the width direction (specifically, positions 5 mm from both ends in the width direction and at the center in the width direction) with a diameter of 5 mm to 10 mm to obtain three measurement samples. The thermal conductivity of each measurement sample is measured using a thermal property measurement device (e.g., LFA-502, Kyoto Electronics Manufacturing Co., Ltd.) that applies the laser flash method. The arithmetic average of the three measured values ​​is defined as the thermal conductivity of the substrate.

[0036] The layer structure of the substrate 20 is not limited. The substrate may have a single-layer structure or a multi-layer structure.

[0037] From the viewpoint of improving productivity, the substrate 20 is preferably a long substrate. The length of the substrate 20 is preferably 10 m or more, more preferably 100 m or more, and particularly preferably 200 m or more. There is no upper limit to the length of the substrate 20. The upper limit of the length of the substrate may be 1,000 m or 500 m. The length of the substrate 20 is preferably within a range of 10 m to 1,000 m. Note that the "length of the substrate" means the distance from one end of the substrate to the other end in the transport direction of the substrate.

[0038] The width of the substrate 20 is not particularly limited, but from the viewpoints of productivity and wrinkle prevention, it is preferably 100 mm to 1,800 mm, more preferably 300 mm to 1,600 mm, and particularly preferably 500 mm to 1,400 mm.

[0039] The thickness of the substrate 20 is not particularly limited, but from the viewpoint of ease of handling, the thickness of the substrate 20 is preferably 3 μm to 50 μm, and more preferably 10 μm to 30 μm.

[0040] The substrate 20 is transported, for example, using a known transport device. The transport device may include a tension control mechanism that controls the tension of the substrate. Examples of the transport device include a transport roller and a transport belt. Other examples of the transport device include a feed device that feeds out the substrate and a winding device that winds up the substrate. The feed device and the winding device are also used, for example, as a roll-to-roll type transport device. The roll-to-roll type transport device is preferably used as a device for transporting a long substrate.

[0041] The conveying speed of the substrate 20 is preferably within the range of 1 m / min to 100 m / min.

[0042] The tension of the substrate 20 is preferably in the range of 30 N / m to 300 N / m, more preferably in the range of 50 N / m to 200 N / m. The tension is controlled, for example, using a known tension control device. The tension may also be controlled using a known conveying device including a tension control mechanism. An example of a conveying device including a tension control mechanism is a conveying device including a tendency drive roller. The tendency drive roller rotates, for example, due to frictional or magnetic force acting between the rotation shaft supporting the tendency drive roller and the tendency drive roller. The rotation shaft is rotated, for example, by a motor. That is, the force that rotates the rotation shaft is transmitted to the tendency drive roller, causing the tendency drive roller to rotate. A conveying device including a tendency drive roller can control the tension of the film, for example, according to the rotation speed of the rotation shaft. Technology related to the tendency drive roller is described, for example, in Japanese Patent No. 4066904. The contents of the above documents are incorporated herein by reference. The tension control may be performed using a dancer roller. The tension control may be performed using a rotary draw control method.

[0043] The coating device according to the present disclosure preferably includes a pressure reducing means connected to the pressure reducing slit for reducing the pressure, and a liquid delivery means connected to the discharge slit for delivering the coating liquid. The pressure reducing means and the liquid delivery means are not particularly limited, and known means can be used. The pressure reducing means can be, for example, a vacuum pump. The liquid delivery means can be, for example, a liquid delivery pump. Furthermore, the coating device according to the present disclosure may have known means, members, etc. other than those described above. For example, the coating device according to the present disclosure may have a drying means for drying the coating liquid. Examples of the drying means include a heating means, an air blowing means, and a combination thereof. The temperature of the air blown is preferably within a range of 25°C to 200°C, and more preferably within a range of 30°C to 150°C. The air speed of the air blown is preferably 1.5 m / sec to 50 m / sec. Examples of the drying means used to dry the coating liquid include an oven, a hot air blower, and an infrared heater.

[0044] (floating transport) The coating device according to the present disclosure is preferably used for coating a substrate that is transported in a floating state. The substrate is preferably transported in a floating state above the coating device. That is, the substrate is preferably transported without contacting the coating device. The floating amount of the substrate is determined, for example, depending on the coating conditions (e.g., the type of coating liquid). From the viewpoint of stabilizing floating transport and achieving a uniform thickness distribution of the coating film, the floating amount of the substrate is preferably 10 μm or more, and more preferably 20 μm or more. The lower limit of the floating amount of the substrate may be 50 μm or 100 μm. From the viewpoint of preventing the coating bead from becoming unstable due to the influence of gravity, the floating amount of the substrate is preferably 1,000 μm or less, more preferably 500 μm or less, and particularly preferably 400 μm or less. The floating amount of the substrate is preferably within the range of 10 μm to 1,000 μm, more preferably 20 μm to 500 μm, and particularly preferably 50 μm to 400 μm. The "floating amount of the substrate" refers to the shortest distance between the first surface of the substrate and the surface of the discharge part facing the first surface of the substrate. The floating amount of the substrate is measured using a laser displacement meter according to the following procedures (1) to (3). The floating amount of the substrate is measured under conditions that exclude the influence of the coating liquid, that is, under conditions where the coating liquid is not applied to the substrate. (1) Using a laser displacement meter arranged opposite the discharge part of the coating device, the position of the surface of the discharge part is detected, and then, while the substrate is being floated and transported, the position of the second surface of the substrate traveling between the discharge part of the coating device and the laser displacement meter is detected. (2) Based on the measurement results obtained in (1) above, the distance D from the surface of the discharge part to the second surface of the floated substrate is measured. (3) The value obtained according to the following formula is regarded as the floating amount of the substrate. Formula: Substrate floating amount = [distance D] - [substrate thickness]

[0045] The degree of curvature of the substrate is expressed, for example, by the radius of curvature. The greater the degree of curvature, the smaller the radius of curvature, and the smaller the degree of curvature, the larger the radius of curvature. From the viewpoint of achieving a uniform thickness distribution of the coating film, the radius of curvature of the substrate at the contact point between the substrate and the coating liquid is preferably within the range of 50 mm to 1,000 mm, more preferably within the range of 70 mm to 600 mm, and particularly preferably within the range of 100 mm to 300 mm. The radius of curvature of the substrate is measured under conditions that exclude the influence of the coating liquid, i.e., under conditions where the coating liquid is not applied to the substrate.

[0046] The method for floating the substrate is not limited. For example, a method for floating the substrate includes supplying a gas between the substrate and the coating device. The gas supplied between the substrate and the coating device supports the substrate and floats the substrate from the coating device. When the substrate is supported by the gas, the coating liquid can be applied to the substrate at a lower discharge pressure, further improving the uniformity of the film thickness distribution of the coating film.

[0047] The type of gas is not limited. Examples of the gas include nitrogen and air. The gas is preferably air.

[0048] The gas may be supplied by a known method, for example, using a blower, a compressor, or a container for storing the gas (for example, a cylinder).

[0049] The gas pressure is not limited. The gas pressure affects, for example, the amount of substrate lift and the degree of substrate bending. The higher the gas pressure, the greater the amount of substrate lift, and the lower the gas pressure, the less the amount of substrate lift. Furthermore, the higher the gas pressure, the greater the degree of substrate bending, and the lower the gas pressure, the less the degree of substrate bending. From the viewpoint of stabilizing the lifting transport and bending the substrate, the pressure of the gas present in the space between the substrate and the coating device (hereinafter sometimes referred to as "P0") is preferably 10 Pa or more, more preferably 50 Pa or more, and particularly preferably 100 Pa or more. "Gas present in the space between the substrate and the coating device" includes not only gas intentionally supplied between the substrate and the coating device, but also gas (e.g., air) present in the space between the substrate and the coating device due to unintentional factors. Furthermore, P0 is preferably 150 Pa or more, more preferably 200 Pa or more. The smaller the gas pressure fluctuation, the more uniform the coating film thickness distribution. From the viewpoint of reducing gas pressure fluctuations, P0 is preferably 2,000 Pa or less, more preferably 1,600 Pa or less, and particularly preferably 1,300 Pa or less. The upper limit of P0 may be 1,000 Pa, 800 Pa, or 500 Pa. P0 is preferably within the range of 10 Pa to 2,000 Pa, more preferably 100 Pa to 1,600 Pa, and particularly preferably 150 Pa to 1,300 Pa. P0 is measured by inserting a metal tube connected to a manostar gauge into the space between the substrate and the coating device.

[0050] The floating transport of the substrate preferably includes blowing gas toward the first surface of the substrate from a blowing section that is located at least one of upstream and downstream of the discharge section in the transport direction of the substrate. The gas blown toward the first surface of the substrate from the blowing section supports the substrate and floats the substrate away from the coating device. The above-described method stabilizes the floating transport of the substrate and improves the uniformity of the film thickness distribution of the coating film. From the viewpoint of stabilizing the floating transport, the blowing sections are preferably located upstream and downstream of the discharge section in the transport direction of the substrate. The blowing sections may be part of the coating device or may be elements independent of the coating device. The blowing sections are preferably part of the coating device. The configuration of the blowing sections is described above in the section "Transportation Process."

[0051] The coating device according to the present disclosure preferably includes a blowing section that blows out gas for floating transport. The coating device may include one or more blowing sections. The blowing section supplies gas between the substrate and the coating device. The gas supplied between the substrate and the coating device supports the substrate in the coating process described below and floats the substrate from the coating device. Examples of components of the discharge section include metals. Examples of metals include stainless steel. The structure of the blowing section is not limited as long as it has the function of blowing out gas. The blowing section may include one or more blowing outlets. Examples of the shape of the blowing outlet in a plan view include circular, elliptical, polygonal, linear, and irregular. The blowing section may be connected to the discharge port and include a space (i.e., a flow path) through which the gas flows. The blowing section may be a nozzle. The blowing section may be a porous body.

[0052] The coating device according to the present disclosure is a coating device that coats a coating liquid on a substrate having a first surface and a second surface opposite to the first surface while being transported. The coating device preferably includes: a discharge unit that discharges the coating liquid toward the first surface of the substrate; and at least one blowing unit that is located at least one upstream or downstream of the discharge unit in the substrate transport direction and blows gas toward the first surface of the substrate to float the substrate. According to the above-described embodiment, a coating device capable of forming a coating film with a uniform film thickness distribution is provided. The blowing units are preferably located upstream and downstream of the discharge unit in the substrate transport direction. The blowing unit located upstream of the discharge unit in the substrate transport direction (hereinafter sometimes referred to as the "first blowing unit") and the blowing unit located downstream of the discharge unit in the substrate transport direction (hereinafter sometimes referred to as the "second blowing unit") stabilize the floating transport of the substrate and improve the uniformity of the film thickness distribution of the coating film. The first blowing unit may or may not be adjacent to the discharge unit. The second blowing section may or may not be adjacent to the discharge section. Preferably, the first blowing section is adjacent to the discharge section, and the second blowing section is adjacent to the discharge section.

[0053] The floating transport of the substrate preferably includes blowing gas toward the first surface of the substrate from a first blowing section disposed upstream of the discharge section and a second blowing section disposed downstream of the discharge section in the substrate transport direction, and independently controlling the pressure of the gas blown from the first blowing section and the second blowing section. This method stabilizes the floating transport of the substrate and improves controllability of the degree of substrate curvature. As a result, the uniformity of the coating film thickness distribution is improved. The pressure of the gas present in the space between the substrate and the first blowing section (hereinafter sometimes referred to as "P1") may be the same as or different from the pressure of the gas present in the space between the substrate and the second blowing section (hereinafter sometimes referred to as "P2"). The "gas present in the space between the substrate and the blowing section" includes not only gas intentionally supplied between the substrate and the blowing section, but also gas (e.g., atmospheric air) present in the space between the substrate and the coating device due to unintentional factors. P1 and P2 are controlled, for example, within the pressure ranges described above. From the viewpoint of achieving a uniform thickness distribution of the coating film, the ratio of P1 to P2 (i.e., P1 / P2) is preferably 0.1 to 1.5, and more preferably 0.3 to 1. P1 is preferably lower than P2. When P1 is lower than P2, the influence of tension fluctuations in the substrate on the thickness distribution of the coating film is reduced, and the uniformity of the thickness distribution of the coating film is also improved. From the above viewpoints, the ratio of P1 to P2 (i.e., P1 / P2) is preferably 0.1 or more and less than 1, more preferably 0.3 to 0.9, and particularly preferably 0.4 to 0.8. P1 is preferably 50 Pa or more lower than P2, and more preferably 100 Pa or more lower than P2. For example, P1 is preferably within the range of 10 Pa to 250 Pa, and P2 is preferably within the range of 300 Pa to 500 Pa. P1 is measured by inserting a metal tube connected to a Manostar gauge into the space between the substrate and the first blowout section, and P2 is measured by inserting a metal tube connected to a Manostar gauge into the space between the substrate and the second blowout section.

[0054] (Coating liquid) The type of coating liquid is not particularly limited. The type of coating liquid is determined, for example, depending on the use of the resulting film. The coating liquid is preferably an aqueous coating liquid. "Aqueous coating liquid" means a coating liquid in which the solvent contained in the coating liquid is substantially water. "The solvent contained in the coating liquid is substantially water" means that water accounts for the majority of the solvent contained in the coating liquid. The proportion of water in the solvent contained in the aqueous coating liquid is preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably 100% by mass.

[0055] Examples of water contained in the aqueous coating liquid include natural water, purified water, distilled water, ion-exchanged water, pure water, and ultrapure water.

[0056] The water content in the aqueous coating liquid is preferably 40% by mass or more, more preferably 50% by mass or more, based on the total mass of the aqueous coating liquid, and is preferably less than 100% by mass, more preferably 80% by mass or less, based on the total mass of the aqueous coating liquid.

[0057] The water-based coating liquid may contain particles, such as inorganic particles, organic particles, and composite particles of inorganic and organic substances.

[0058] Inorganic particles include, for example, metal particles, semi-metal particles, metal compound particles, semi-metal compound particles, inorganic pigment particles, mineral particles, and polycrystalline diamond particles. Metals include, for example, alkali metals, alkaline earth metals, transition metals, and alloys thereof. Semi-metals include, for example, silicon. Metal compounds and semi-metal compounds include, for example, oxides, hydroxides, and nitrides. Inorganic pigments include, for example, carbon black. Minerals include, for example, mica.

[0059] Examples of organic particles include resin particles and organic pigment particles.

[0060] Examples of composite particles of an inorganic substance and an organic substance include composite particles in which inorganic particles are dispersed in a matrix of an organic substance, composite particles in which organic particles are coated with an inorganic substance, and composite particles in which inorganic particles are coated with an organic substance.

[0061] The particles may be surface treated to improve dispersibility, or the surface treatment may result in the formation of composite particles.

[0062] The particle size, specific gravity, and form of use of the particles are not limited and are determined, for example, according to the coating film formed by the coating liquid and the production conditions of the coating film.

[0063] The water-based coating liquid may contain one or more types of particles.

[0064] The content of particles in the water-based coating liquid is not limited and is determined depending on, for example, the purpose of adding the particles, the coating film to be formed from the coating liquid, and the production conditions of the coating film.

[0065] Examples of components of the water-based coating liquid include binder components, components that contribute to particle dispersibility, polymerizable compounds, polymerization initiators, and components for improving coating performance (for example, surfactants).

[0066] The solid content of the coating liquid is preferably less than 70% by mass, and more preferably 30% to 60% by mass.

[0067] When forming an electrode film for a battery, the coating liquid preferably contains an electrode active material, and more preferably contains an electrode active material and a conductive aid. The electrode active material is a substance capable of inserting and releasing ions of a metal element belonging to Group 1 or Group 2 of the periodic table. Examples of the electrode active material include a positive electrode active material and a negative electrode active material.

[0068] -Positive electrode active material- The positive electrode active material is not limited and may be any known electrode active material used for positive electrodes. The positive electrode active material is preferably a positive electrode active material that can reversibly insert and release lithium ions.

[0069] Specific examples of the positive electrode active material include transition metal oxides and elements that can be composited with lithium (e.g., sulfur). Among the above, the positive electrode active material is preferably a transition metal oxide.

[0070] The transition metal oxide is preferably a transition metal oxide containing at least one transition metal element (hereinafter referred to as "element Ma") selected from the group consisting of Co (cobalt), Ni (nickel), Fe (iron), Mn (manganese), Cu (copper), and V (vanadium).

[0071] When the transition metal oxide contains Li and the element Ma, the molar ratio of Li to Ma (Li / Ma) is preferably 0.3 to 2.2.

[0072] The transition metal oxide may also contain at least one transition metal element (hereinafter referred to as "element Mb") selected from the group consisting of Group 1 elements other than lithium, Group 2 elements, Al (aluminum), Ga (gallium), In (indium), Ge (germanium), Sn (tin), Pb (lead), Sb (antimony), Bi (bismuth), Si (silicon), P (phosphorus), and B (boron). The content of element Mb is preferably 0 mol % to 30 mol % relative to the amount of element Ma.

[0073] Examples of transition metal oxides include transition metal oxides having a layered rock salt structure, transition metal oxides having a spinel structure, lithium-containing transition metal phosphate compounds, lithium-containing transition metal halide phosphate compounds, and lithium-containing transition metal silicate compounds.

[0074] Examples of transition metal oxides having a layered rock salt structure include LiCoO2 (lithium cobalt oxide [LCO]), LiNi2O2 (lithium nickel oxide), LiNi 0.85 Co 0.10 Al 0.05 O2 (nickel cobalt lithium aluminate [NCA]), LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (lithium nickel manganese cobalt oxide [NMC]), and LiNi 0.5 One example is Mn0.5O2 (lithium manganese nickel oxide).

[0075] Examples of transition metal oxides having a spinel structure include LiCoMnO4, Li2FeMn3O8, Li2CuMn3O8, Li2CrMn3O8, and Li2NiMn3O8.

[0076] Examples of lithium-containing transition metal phosphate compounds include olivine-type iron phosphate salts (e.g., LiFePO4 and Li3Fe2(PO4)3), iron pyrophosphate salts (e.g., LiFeP2O7), cobalt phosphate salts (e.g., LiCoPO4), and monoclinic Nasicon-type vanadium phosphate salts (e.g., Li3V2(PO4)3 (lithium vanadium phosphate)).

[0077] Examples of lithium-containing transition metal halophosphate compounds include iron fluorophosphates (e.g., LiFePOF), manganese fluorophosphates (e.g., LiMnPOF), and cobalt fluorophosphates (e.g., LiCoPOF).

[0078] Examples of lithium-containing transition metal silicate compounds include Li2FeSiO4, Li2MnSiO4, and Li2CoSiO4.

[0079] The transition metal oxide is preferably a transition metal oxide having a layered rock salt structure, such as LiCoO2 (lithium cobalt oxide [LCO]), LiNi 0.85 Co 0.10 Al 0.05O2 (nickel cobalt lithium aluminum oxide [NCA]), and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (lithium nickel manganese cobalt oxide [NMC]) is more preferred.

[0080] The positive electrode active material may be a commercially available product or a synthetic product produced by a known method (e.g., a calcination method). For example, the positive electrode active material obtained by the calcination method may be washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent. The positive electrode active material may have a carbon coating on its surface.

[0081] The positive electrode active material may be used alone or in combination of two or more. Furthermore, even when one type of positive electrode active material is used, positive electrode active materials having different particle sizes may be used in combination.

[0082] -Negative electrode active material- The negative electrode active material is not limited and may be any known electrode active material used for negative electrodes. The negative electrode active material is preferably a negative electrode active material that can reversibly insert and release lithium ions.

[0083] Examples of the negative electrode active material include carbonaceous materials, metal oxides (e.g., tin oxide), silicon oxide, metal composite oxides, lithium alone, lithium alloys (e.g., lithium-aluminum alloys), and metals capable of forming alloys with lithium (e.g., Sn, Si, and In). Among these, the negative electrode active material is preferably a carbonaceous material or a lithium composite oxide from the viewpoint of reliability.

[0084] A carbonaceous material is a material that consists essentially of carbon. Examples of carbonaceous materials include petroleum pitch, carbon black (e.g., acetylene black), graphite (e.g., natural graphite and artificial graphite (e.g., vapor-grown graphite)), hard carbon, and carbonaceous materials obtained by calcining synthetic resins (e.g., polyacrylonitrile (PAN) and furfuryl alcohol resin). Examples of carbonaceous materials include carbon fibers (e.g., polyacrylonitrile-based carbon fibers, cellulose-based carbon fibers, pitch-based carbon fibers, vapor-grown carbon fibers, dehydrated PVA (polyvinyl alcohol)-based carbon fibers, lignin carbon fibers, glassy carbon fibers, and activated carbon fibers). Examples of graphite include mesophase microspheres, graphite whiskers, and tabular graphite. In this disclosure, "flat" means a shape having two major planes facing in opposite directions.

[0085] The metal composite oxide is preferably a metal composite oxide capable of absorbing and releasing lithium. From the viewpoint of high current density charge / discharge characteristics, the metal composite oxide capable of absorbing and desorbing lithium preferably contains at least one element selected from the group consisting of titanium and lithium.

[0086] The metal oxide and metal composite oxide are particularly preferably amorphous oxides.

[0087] The metal oxides and composite metal oxides are also preferably chalcogenides, which are reaction products of metal elements and elements of Group 16 of the periodic table.

[0088] Among the compound group consisting of amorphous oxides and chalcogenides, amorphous oxides and chalcogenides of metalloid elements are preferred, and oxides and chalcogenides containing at least one element selected from the group consisting of elements of Groups 13 to 15 of the periodic table, Al, Ga, Si, Sn, Ge, Pb, Sb, and Bi are more preferred.

[0089] It is also preferable that the negative electrode active material further contains titanium. From the viewpoints of excellent rapid charge / discharge characteristics due to small volume fluctuations during absorption and release of lithium ions and of the ability to extend the life of the lithium ion secondary battery by suppressing electrode deterioration, the negative electrode active material containing titanium is preferably Li4Ti5O 12 (lithium titanate [LTO]) is preferred.

[0090] The negative electrode active material may be a commercially available product or a synthetic product produced by a known method (e.g., a calcination method). For example, the negative electrode active material obtained by the calcination method may be washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

[0091] The negative electrode active material is available, for example, as CGB20 (manufactured by Nippon Graphite Industries Co., Ltd.).

[0092] The composition of the negative electrode active material is measured using inductively coupled plasma (ICP) emission spectroscopy.

[0093] The negative electrode active material may be used alone or in combination of two or more kinds. Furthermore, even when one type of negative electrode active material is used, negative electrode active materials having different particle sizes may be used in combination.

[0094] The surfaces of the positive electrode active material and the negative electrode active material may each be coated with a surface coating agent. Examples of the surface coating agent include metal oxides containing Ti, Nb, Ta, W, Zr, Si, or Li. Examples of the metal oxide include titanate spinel, tantalum-based oxides, niobium-based oxides, and lithium niobate-based compounds.

[0095] -Conductive additive- The conductive aid is not particularly limited, and known conductive aids can be used. Examples of conductive additives include graphite (e.g., natural graphite and artificial graphite), carbon black (e.g., acetylene black, ketjen black, and furnace black), amorphous carbon (e.g., needle coke), carbon fibers (e.g., vapor-grown carbon fibers and carbon nanotubes), other carbonaceous materials (e.g., graphene and fullerene), metal powders (e.g., copper powder and nickel powder), metal fibers (e.g., copper fibers and nickel fibers), and conductive polymers (e.g., polyaniline, polypyrrole, polythiophene, polyacetylene, and polyphenylene derivatives). The conductive assistant may be used alone or in combination of two or more kinds. [Example]

[0096] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, details of each step, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present disclosure. Therefore, the scope of the present disclosure is not limited to the specific examples shown below. All "parts" are based on mass.

[0097] Example 1 (Preparation of substrate AL1) An aluminum film with a width of 220 mm, a thickness of 10 μm, a length of 300 m, and a thermal conductivity of 230 W / m·K was prepared as the substrate AL1. The substrate AL1 was wound into a roll to form a roll film.

[0098] (Preparation of solvent-based coating solution A) Graphite (C) as the negative electrode active material, styrene butadiene rubber (SBR) as a binder, carboxymethyl cellulose (CMC) and polyvinylpyrrolidone (PVP) as viscosity modifiers, and graphite (GF) and carbon black (CB) as conductive additives were blended in a mass ratio of C:SBR:CMC:PVP:GF:CB=94:2:1:1:1:1, and kneaded with ion-exchanged water to obtain a solvent-based coating solution A with a solids concentration of 60 mass%.

[0099] (Preparation of solvent-based coating solution B) LiNi 0.5 Co 0.2 Mn 0.3 95 parts by mass of O2 (NCM523) and 2.5 parts by mass of acetylene black were mixed, and 2.5 parts by mass of polyvinylidene fluoride powder (product name "PVDF5130", manufactured by Solvay) was gradually added, followed by kneading with a planetary mixer. 54 parts by mass of N-methylpyrrolidone was added, yielding a solvent-based coating solution B with a solids concentration of 65% by mass.

[0100] (Preparation of coating solution C) The following components were mixed to prepare coating solution C. Polyvinyl alcohol (CKS-50, saponification degree: 99 mol%, polymerization degree: 300, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.): 58 parts by mass Cellogen PR (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 24 parts by weight Surfactant (Emalex 710, manufactured by Nippon Emulsion Co., Ltd.): 5 parts by mass Art Pearl (registered trademark) J-7P water dispersion: 913 parts by weight

[0101] An aqueous dispersion of Art Pearl J-7P was prepared as follows: 3 parts by weight of Emalex 710 (a nonionic surfactant manufactured by Nippon Emulsion Co., Ltd.) and 3 parts by weight of sodium carboxymethylcellulose (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) were added to 74 parts by weight of pure water. 20 parts by weight of Art Pearl J-7P (silica composite crosslinked acrylic resin particles manufactured by Negami Chemical Industrial Co., Ltd.) were added to the resulting aqueous solution, and the mixture was dispersed at 10,000 rpm for 15 minutes using an Ace Homogenizer (manufactured by Nippon Seiki Seisakusho Co., Ltd.) to obtain an aqueous dispersion of Art Pearl J-7P (particle concentration: 20% by weight). The true specific gravity of the silica composite crosslinked acrylic resin particles in the resulting aqueous dispersion was 1.20, and the average particle size was 6.5 μm.

[0102] Example 1 Using a coating device in which the discharge slit and the decompression slit were arranged in the positional relationship shown in Figures 2 to 4, the coating liquid A was applied to the substrate AL1 at the position and shape of the decompression slit shown in Table 1 and at a reduced pressure of 1,000 Pa to form a coating liquid film, and the formed coating liquid film was dried to obtain a coating film. Specifically, the water-based coating liquid A was applied onto a continuously transported substrate so that the width of the coated area was 200 mm and the width of the uncoated area between the edge of the substrate and the coated area was 10 mm. The transport speed of the substrate was 2.0 m / min. In this manner, a coating film having a thickness of 70 μm was formed.

[0103] <Examples 2 to 10 and Comparative Examples 1, 3 and 4> As shown in Table 1, a coating film was formed in the same manner as in Example 1, except that the decompression method, the position and shape of the decompression slit, and the coating liquid were changed. In Example 4, a coating device configured as shown in FIG. 5 was used.

[0104] Example 11 A coating film was formed in the same manner as in Example 1, except that the substrate AL1 was floated and transported using the apparatus described in Example 1 of WO 2022 / 130902 and coated using the same coating apparatus as in Example 5. The productivity of the coating film was doubled compared to Example 5. In the normal coating method as in Example 5, two processes must be performed to coat both the front and back surfaces, whereas in the floating coating method as in Example 11, the front and back surfaces can be coated and dried simultaneously, so only one process is required. In other words, productivity is doubled.

[0105] <Comparative Example 2> A coating film was formed in the same manner as in Example 1, except that the coating apparatus shown in FIGS. 1 to 3 of JP-A-2008-155164 was used.

[0106] <Evaluation of the ability to prevent thickening of the film at the width direction edges during film formation (edge ​​thickening prevention)> The film thickness profile in the width direction was measured, and the difference between the maximum and minimum values ​​at 5 mm from the end in the width direction was used as an index of film thickness. The extent to which this difference was reduced by decompression was evaluated. The film thickness profile measurement in the width direction is not particularly limited, but for example, a continuous thickness measuring instrument FT-A-200 manufactured by Fuji Work Co., Ltd. can be suitably used. The evaluation criteria are as follows. A: The difference between the maximum and minimum values ​​is reduced by 80% or more due to the pressure reduction. B: The difference between the maximum and minimum values ​​is reduced by 30% or more but less than 80% due to the reduced pressure. C: The difference between the maximum and minimum values ​​is 3 μm or more, and the difference between the maximum and minimum values ​​is reduced by less than 30%.

[0107] <Evaluation of the necessity of large-scale facilities> The evaluation was based on the necessity of additional equipment other than the slot die required for coating. Specifically, the pressure reducing devices used in Patent Documents 1 and 2 require a relatively large pressure reducing chamber, equal to or larger than the width of the substrate, on the upstream side in the substrate flow direction in order to reduce the pressure uniformly across the entire width (=F: Required). On the other hand, when reducing the pressure in the slit at the tip of the die lip, a large pressure reducing chamber is not required (=A: (not required).

[0108] <Evaluation of decompression slit clogging prevention> After the coating was completed, the slot die was disassembled, and the degree to which the coating liquid and its dried product had adhered to the decompression slit 14 was visually evaluated. The evaluation criteria were as follows: A: The coating liquid and its dried material are not attached to the decompression slit and decompression path. B: The coating liquid and its dried material adhere to the decompression slit and the decompression path, but not to the decompression slit opening. C: The coating liquid and its dried matter adhere to the decompression slit and decompression path, and 0 to 30% of the decompression slit opening is blocked. D: The coating liquid and its dried material are attached to the decompression slit and decompression path, and the decompression slit opening is blocked by 30% or more.

[0109] The evaluation results are summarized in Table 1.

[0110] [Table 1]

[0111] In Table 1, the positive and negative signs at the positions of the decompression slits are positive on the inside from the end in the width direction of the discharge slit, and negative on the outside. In addition, the thickness direction position of the decompression slit in Examples 1 to 11 and Comparative Examples 3 and 4 was such that the end of the decompression slit closest to the discharge slit in the thickness direction of the discharge slit was located 5 mm upstream from the thickness direction end of the discharge slit in the substrate conveying direction. The conventional chamber method in Table 1 refers to a pressure reduction method in which a pressure reduction chamber (= chamber) with a width equal to or greater than the width of the substrate is installed upstream in the substrate flow direction, and which generates a fairly large, uniform suction pressure to reduce the pressure uniformly across the entire width.The direct slit method refers to a method in which a slit is installed near the tip of the die lip (directly below the slit) to reduce the pressure.

[0112] As shown in Table 1, the coating devices of Examples 1 to 11, which are coating devices according to the present disclosure, are superior in terms of preventing blockage of the decompression slit and preventing thickening of the film at the widthwise ends during film formation, compared to the coating devices of Comparative Examples 1 to 4. [Explanation of symbols]

[0113] 10: slot die, 12: discharge slit, 14: decompression slit, 16: slot die member, 18: waste liquid chamber, 20: substrate, L1: width of discharge slit 12, L2: distance between end of discharge slit 12 and end of decompression slit in width direction of discharge slit 12, L3: distance between end of discharge slit 12 and end of decompression slit in thickness direction of discharge slit 12, 12P: liquid transfer path, 14P: decompression path, F1: liquid transfer direction, R1: decompression direction, S1: substrate transfer direction

Claims

1. a slot die having a discharge slit for discharging a coating liquid onto a substrate being conveyed and a decompression slit; The decompression slit is located upstream of the discharge slit in the substrate conveying direction of the slot die and on the outer side in the width direction of the discharge slit. Coating equipment.

2. The opening of the decompression slit is 3 mm ２ The coating device of claim 1 .

3. 3. The coating device according to claim 1, wherein the decompression slit is positioned 5 mm or more outward in the width direction from the end of the discharge slit in the width direction.

4. 3. The coating device according to claim 1, which is used to coat a substrate that is transported in a floating state.

5. 3. The coating device according to claim 1, which is used for coating a water-based coating liquid.

6. 3. The coating device according to claim 1, which is used for forming an electrode film of a battery.

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