Coating apparatus and coating method

Abstract

A coating device (20) applies a coating liquid (C) to both surfaces of a sheet-like substrate (2) being conveyed. The coating device (20) has a pair of blocks (21, 22) facing each other in the thickness direction of the substrate (2), and a liquid pool portion (23) formed in the gap between the pair of blocks (21, 22) to store the coating liquid (C) and allow the substrate (2) to pass therethrough. The liquid pool portion (23) includes a guide inlet (24) that opens on the upstream side in the conveying direction of the substrate (2) and guides the substrate (2) to be introduced, a discharge outlet (25) that opens on the downstream side in the conveying direction and discharges the substrate (2), and side surface portions (26) respectively on both sides in the width direction intersecting the conveying direction. The side surface portion (26) on at least one side in the width direction includes an exposure opening (29) that opens in the range from the guide inlet (24) to the discharge outlet (25). A part of the substrate (2) in the width direction can protrude from the exposure opening (29) to the outside of the liquid pool portion (23).

Description

TECHNICAL FIELD

[0001] The present application relates to a coating apparatus and a coating method. BACKGROUND

[0002] Various techniques have been disclosed with respect to a coating apparatus for forming a coating film on both surfaces of a sheet-like substrate conveyed, for example, by a roll-to-roll method.

[0003] For example, in the coating apparatus (coating apparatus) disclosed in Patent Literature 1, first, a long, continuous sheet-like substrate is dipped into an immersion tank in which a coating liquid is accumulated, thereby coating the coating liquid on both surfaces of the substrate. Then, while the substrate is raised in the vertical direction, a pair of doctor rollers is used to scrape off the excess coating liquid on both surfaces of the substrate. Thereby, a coating film of a certain thickness is formed on both surfaces of the substrate.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 64-7965 SUMMARY

[0007] The coating apparatus of the present application coats a coating liquid on both surfaces of a sheet-like substrate being conveyed, wherein the coating apparatus comprises: a pair of blocks opposed to each other in a thickness direction of the substrate; and a liquid accumulation portion formed in a gap between the pair of blocks to accumulate the coating liquid and through which the substrate passes, the liquid accumulation portion including: a guide inlet opened on an upstream side in a conveying direction of the substrate and guiding the substrate in; a discharge outlet opened on a downstream side in the conveying direction and discharging the substrate; and side portions respectively located on both sides in a width direction crossing the conveying direction, at least one of the side portions in the width direction including an exposure outlet opened in a range from the guide inlet to the discharge outlet, a part of the substrate in the width direction being able to protrude from the exposure outlet to an outside of the liquid accumulation portion. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a view schematically showing a coating system including a coating apparatus of a first embodiment of the present application.

[0009] Figure 2 is a front view of the coating apparatus of the first embodiment.

[0010] Figure 3 is a plan view of the coating apparatus of the first embodiment.

[0011] Figure 4 is a side view of the coating apparatus of the first embodiment.

[0012] Figure 5 is an enlarged front view of the vicinity of the discharge port of the coating apparatus of the first embodiment.

[0013] Figure 6 is a side view of the coating apparatus of the second embodiment.

[0014] Figure 7 is a side view of the coating apparatus of the third embodiment.

[0015] Figure 8 is a front view of the coating apparatus of the fourth embodiment.

[0016] Figure 9 is a top cross-sectional view of the coating apparatus of the fourth embodiment.

[0017] Figure 10 is a top cross-sectional view of the coating apparatus of the fifth embodiment.

[0018] Figure 11 is a front view of the coating apparatus of the sixth embodiment.

[0019] Figure 12 is a front view of the coating apparatus of the seventh embodiment.

[0020] Figure 13 is a front view of the coating apparatus of the eighth embodiment.

[0021] Figure 14 is a top view of the coating apparatus of the ninth embodiment.

[0022] Figure 15 is a top view of the coating apparatus of the tenth embodiment.

[0023] Figure 16 is a side view of the coating apparatus of the eleventh embodiment.

[0024] BRIEF DESCRIPTION OF REFERENCE NUMERALS:

[0025] X conveyance direction

[0026] Y width direction

[0027] Z thickness direction

[0028] P specific site

[0029] Q non-specific site

[0030] H gap size

[0031] H1 gap size

[0032] H2 gap size

[0033] C coating liquid

[0034] F coating film

[0035] M wetting expansion inhibiting portion

[0036] 2 substrate

[0037] 20 coating device

[0038] 21 first block (pair of blocks)

[0039] 22 second block (pair of blocks)

[0040] 3 liquid accumulation portion (gap)

[0041] 24 inlet

[0042] 25 outlet

[0043] 26 side portion

[0044] 26a first side portion

[0045] 26b second side portion

[0046] 29 outlet

[0047] 30 coating liquid supply port

[0048] 31 opening edge portion DETAILED DESCRIPTION

[0049] There are cases where a coating film is selectively formed on both surfaces of a specific portion in the width direction of a substrate. In such cases, it is necessary to apply a coating liquid to both surfaces of the specific portion in the width direction of the substrate, on the other hand, it is not necessary to apply the coating liquid to portions other than the specific portion.

[0050] However, in the case where the coating device of the above-described Patent Document 1 is used to selectively form a coating film on both surfaces of a specific portion in the width direction of a substrate, in order to immerse only the specific portion of the substrate in the immersion tank, it is necessary to adjust the orientation of the substrate itself, the transport direction of the substrate, and the like, and thus there are problems that lead to complication of the coating process, and large-scale of the coating device.

[0051] The present application was completed in view of the above-described circumstances, and the main object thereof is to be able to selectively form a coating film on both surfaces of a specific portion in the width direction of a substrate being transported.

[0052] Hereinafter, the embodiments of the present application will be described in detail based on the drawings. The description of the following preferred embodiments is merely illustrative in nature and is in no way intended to limit the present application, its application, or its uses.

[0053] <First Embodiment>

[0054] (Basic Structure)

[0055] Figure 1 A coating system 1 of a first embodiment of the present application is schematically shown. The coating system 1 is used to continuously form a coating film F on both sides of a substrate 2. The coating system 1 is composed of a substrate supply device 10, a coating device 20, and a coating liquid supply device 40.

[0056] The substrate 2 is formed in a long strip shape. As the substrate 2, for example, there are a metal foil, a resin film, a woven cloth, a nonwoven cloth, paper, and the like. The thickness dimension t (refer to FIG. 2) of the substrate 2, which does not include the coating film F, is, for example, 1 mm or less. Figure 5 ) for example, 1 mm or less.

[0057] The substrate supply device 10 continuously transports the substrate 2 in a long edge direction thereof as a transport direction (indicated by X) by a roll-to-roll method. Specifically, the substrate supply device 10 unwinds the substrate 2 by means of an unwinder 11 and winds the substrate 2 by means of a winder 12, thereby continuously transporting the substrate 2. The transported substrate 2 passes through a first roller 13 and a second roller 14 midway.

[0058] The coating device 20 is disposed between the first roller 13 and the second roller 14 in the transport direction of the substrate 2. Although details will be described later, the coating device 20 applies a coating liquid C to both sides of the continuously transported substrate 2 in a sheet shape, thereby forming the coating film F on both sides of the substrate 2. The substrate 2 on which the coating film F is formed on both sides by the coating device 20 is dried in a drying furnace (not shown) and removed of volatile components contained in the coating film F, and is wound on the winder 12.

[0059] The coating device 20 is described in detail. Figures 2 to 5 The coating device 20 of the present embodiment is shown, Figure 2 is a front sectional view (II-direction view), Figure 3 is a side view (III-direction view), Figure 4 is a plan view (IV-direction view), Figure 5 is an enlarged front view of the vicinity of the discharge port 25 described later.

[0060] Note that, in the present embodiment, the transport direction (long edge direction) of the substrate 2 and the horizontal direction orthogonal to the vertical direction are substantially identical. In addition, the thickness direction (indicated by Z) of the substrate 2 and the vertical direction are substantially identical. The width direction (indicated by Y) of the substrate 2 and the horizontal direction intersecting the transport direction of the substrate 2, specifically, the horizontal direction orthogonal to the transport direction, are substantially identical.

[0061] As Figure 2As shown, the coating device 20 has a pair of blocks, specifically, the coating device 20 has a first block 21 and a second block 22. The first block 21 and the second block 22 are arranged at a prescribed interval from each other in the thickness direction of the substrate 2, and the first block 21 and the second block 22 are opposed to each other in the thickness direction of the substrate 2. Each block 21, 22 is formed in a substantially cuboid shape, and each block 21, 22 is arranged with its long side direction along the conveyance direction of the substrate 2.

[0062] In Figure 3 , 4 , L1 is the length dimension of each block 21, 22. L2 is the width dimension of each block 21, 22. L3 is the thickness dimension of each block 21, 22.

[0063] It is preferable that the length dimension L1 of each block 21, 22 be sufficiently large with respect to the thickness dimension t of the substrate 2 (refer to Figure 5 ). Specifically, it is preferable that the length dimension L1 of each block 21, 22 be 100 times or more the thickness dimension t of the substrate 2, and more preferably, the length dimension L1 of each block 21, 22 be 500 times or more the thickness dimension t of the substrate 2.

[0064] As shown in Figure 4 , in the present embodiment, the width dimension L2 of each block 21, 22 is smaller than the width dimension B of the substrate 2.

[0065] As shown in Figure 2 , a gap 23 between the pair of blocks, that is, a gap 23 between the first block 21 and the second block 22 is formed with a liquid pool portion (hereinafter referred to as "liquid pool portion 23") to accumulate the coating liquid C. The substrate 2 passes through the liquid pool portion 23, whereby the coating liquid C is applied to both surfaces of the substrate 2, and a coating film F is formed on both surfaces of the substrate 2.

[0066] The coating liquid C is preferably in a paste or slurry state, and for example, a coating liquid C having a viscosity η of 1 mPa s or more can be applied to both surfaces of the substrate 2. In addition, for example, in the case where a coating liquid C having a viscosity η of 1 Pa s to 1000 Pa s is applied, a coating film F can be smoothly formed on both surfaces of the substrate 2, and thus, it is preferable.

[0067] The coating liquid C can use, for example, silicon dioxide, low-melting-point glass, an insulator material containing metal oxide particles such as aluminum oxide and titanium oxide, solder, metal particles such as copper, silver, and particles covered with metal, a conductive material containing lithium nickelate, lithium manganate, lithium cobaltate, and carbon, a dye, and the like.

[0068] H denotes a gap size between the first block 21 and the second block 22. In the present embodiment, the gap size H is the same in the range of the conveying direction and the width direction. The gap size H is larger than the thickness size t of the substrate 2 (for example, 0.1 mm or less) so that the substrate 2 can pass through. The gap size H is preferably as small as possible. Specifically, the gap size H is preferably 0.1 mm or more and 1 mm or less.

[0069] The liquid-accumulating portion 23 includes a guide inlet 24 that opens on the upstream side (left side in Figure 2 ) in the conveying direction of the substrate 2, and a discharge outlet 25 that opens on the downstream side (right side in Figure 2 ) in the conveying direction of the substrate 2. The guide inlet 24 and the discharge outlet 25 are opposed to each other in the conveying direction. The substrate 2 is guided from the guide inlet 24 and discharged from the discharge outlet 25 through the liquid-accumulating portion 23.

[0070] As shown in Figure 3 , 4 , the liquid-accumulating portion 23 includes side surface portions 26 that are respectively located on both sides in the width direction of the substrate 2. The side surface portions 26 are constituted by a first side surface portion 26a on one side in the width direction and a second side surface portion 26b on the other side in the width direction. The first side surface portion 26a and the second side surface portion 26b are opposed to each other in the width direction.

[0071] The side surface portion 26 on at least one side in the width direction includes an exposure port 29. In the present embodiment, as shown in Figure 4 , the side surface portions 26 on both sides in the width direction, i.e., the first side surface portion 26a and the second side surface portion 26b, respectively include the exposure port 29. Each exposure port 29 opens in the range from the guide inlet 24 side (upstream side) to the discharge outlet 25 side (downstream side) in the first side surface portion 26a and the second side surface portion 26b (see Figure 2 ). That is, the first side surface portion 26a and the second side surface portion 26b are open.

[0072] As shown in Figure 4 , a part in the width direction of the substrate 2 can protrude from the exposure port 29 to the outside of the liquid-accumulating portion 23.

[0073] A coating liquid supply port 30 for supplying the coating liquid C to the liquid-accumulating portion 23 is provided on a surface of the first block 21 that faces the liquid-accumulating portion 23. In the present embodiment, a plurality of (for example, three) coating liquid supply ports 30 are arranged in the width direction central portion of the first block 21 in the conveying direction. Note that the coating liquid supply port 30 can also be one.

[0074] Here, a coating liquid supply device 40 (see Figure 1) is a device for supplying the coating liquid C to the coating device 20, and the coating liquid supply device 40 is constituted by a supply pump 41 and a supply path 42. The coating liquid supply port 30 communicates with the supply pump 41 via the supply path 42. The coating liquid C pressurized by the supply pump 41 is supplied from the coating liquid supply port 30 to the liquid pool portion 23 through the supply path 42. Thus, the coating liquid C is accumulated in the liquid pool portion 23. The cross-sectional shape of the coating liquid supply port 30 is, for example, circular, elliptical. The diameter of the coating liquid supply port 30 is, for example, preferably 1 mm or more. Further, the supply speed of the coating liquid C based on the supply pump 41 is preferably substantially in accordance with the discharge speed of the coating liquid C discharged from the discharge port 25.

[0075] Although not shown, the coating device 20 can also be provided with a coating liquid discharge mechanism. The coating liquid discharge mechanism removes the coating liquid C accumulated in the liquid pool portion 23 at the time of coating stop.

[0076] (Method of coating)

[0077] A method of coating the coating liquid C to both faces of the substrate 2 by the coating device 20 to form the coating film F on both faces of the substrate 2 (coating method) will be described.

[0078] First, as shown in Figure 3 , a position at which the coating liquid C is coated is determined in the width direction of the substrate 2, and is set as a specific portion P. Further, a position other than the specific portion P in the width direction is set as a non-specific portion Q at which the coating liquid C is not coated.

[0079] In the present embodiment, the width direction middle portion 2b of the substrate 2 is set as the specific portion P. On the other hand, the positions other than the specific portion P (width direction middle portion 2b) in the width direction of the substrate 2, i.e., the width direction end portions 2a are set as the non-specific portions Q.

[0080] As shown in Figure 3 , 4 , the position in the width direction of the substrate 2 is adjusted so that the specific portion P of the substrate 2 passes through the liquid pool portion 23, and on the other hand, each non-specific portion Q of the substrate 2 does not pass through the liquid pool portion 23. Specifically, each non-specific portion Q (each width direction end portion 2a) of the substrate 2 passing through the coating device 20 is caused to protrude from each discharge port 29 to the outside of the liquid pool portion 23.

[0081] The substrate 2 passes through the coating device 20, whereby the coating liquid C is coated to both faces of the specific portion P of the substrate 2, and the coating film F is formed on both faces of the specific portion P of the substrate 2. On the other hand, on both faces of each non-specific portion Q of the substrate 2, since the coating liquid C is not coated, the coating film F is not formed.

[0082] At the time of discharge of the substrate 2 from the discharge port 25, in the vicinity of the discharge port 25, a strong shear force is applied to the coating liquid C coated to both faces of the specific portion P of the substrate 2. Thus, as shown inFigure 5 As shown, the thickness dimension T of the substrate 2 including the coating film F is slightly smaller than the gap dimension H of the discharge port 25 (the liquid pool portion 23). Thereby, the surface of the coating film F is smoothed, and the appearance is good.

[0083] (EFFECTS)

[0084] According to the present application, a coating film can be selectively formed on both surfaces of a specific portion in the width direction of the substrate being conveyed. Specifically, at least one side of the side portion 26 in the width direction includes the exposure port 29, and thus a portion in the width direction of the substrate 2 passing through the coating device 20 can be caused to protrude from the exposure port 29 to the outside of the liquid pool portion 23.

[0085] That is, in the width direction of the substrate 2, a portion to which the coating liquid C is applied is set as the specific portion P, and a portion to which the coating liquid C is not applied is set as the non-specific portion Q. Then, the substrate 2 is caused to pass through the coating device 20 while the non-specific portion Q of the substrate 2 protrudes from the exposure port 29 to the outside of the liquid pool portion 23. Thereby, the coating liquid C can be applied to both surfaces of the specific portion P of the substrate 2 without being applied to both surfaces of the non-specific portion Q of the substrate 2.

[0086] Thus, a coating film F can be selectively formed on both surfaces of the specific portion P in the width direction of the substrate 2 being conveyed.

[0087] Further, in the present embodiment, the first side portion 26a and the second side portion 26b on both sides in the width direction each include the exposure port 29, and thus in a case where the width dimension B of the substrate 2 is larger than the width dimension (the width dimension L2 of the liquid pool portion 23) of each block 21, 22, both of the width direction end portions 2a of the substrate 2 can be caused to protrude from each exposure port 29 to the outside of the liquid pool portion 23.

[0088] By reducing the gap dimension H to, for example, 0.1 mm to 1 mm, the ratio p [kg / (m2·s) x 10 3 ] of the viscosity η [Pa·s] of the coating liquid C to the gap dimension H [mm] can be increased as much as possible. By increasing the ratio p (preferably, 75 or more), the leakage of the coating liquid C from the liquid pool portion 23 is suppressed. Note that by increasing the viscosity η of the coating liquid C, the ratio p can also be increased.

[0089] By setting the viscosity η of the coating liquid C to, for example, 1 Pa·s to 1000 Pa·s, the leakage of the coating liquid C from the liquid pool portion 23 can be suppressed, the surface roughness of the coating film F can be improved, the pressure loss of the coating liquid C in the supply path 42 can be reduced, and the like.

[0090] Since the conveying direction of the substrate 2 is substantially in line with the horizontal direction, the coating liquid C accumulated in the liquid-accumulating portion 23 is supported by the first block 21 located below in the vertical direction (thickness direction) thereof. This is more advantageous in terms of suppressing leakage of the coating liquid C from the liquid-accumulating portion 23.

[0091] By making the length dimension LI of each block 21, 22 sufficiently large with respect to the thickness dimension t of the substrate 2, it is possible to suppress omission of coating on both sides of the specific portion P of the substrate 2, thereby improving the coverage rate.

[0092] By increasing the diameter of the coating liquid supply port 30 to, for example, 1 mm or more, it is possible to reduce the pressure loss of the coating liquid C supplied to the liquid-accumulating portion 23.

[0093] For example, in the dip coating method, the substrate is introduced into the dip tank from the upper inlet, is passed through the inside of the dip tank, and is discharged from the upper outlet. Therefore, it is necessary to change the conveying direction of the substrate 2 multiple times, and the device becomes large and complex. In addition, since it is necessary to accumulate a large amount of the coating liquid C in the dip tank, it is disadvantageous in terms of cost, particularly in the case where a high-priced coating liquid C is used. According to the present embodiment, the inlet 24 and the outlet 25 are opposed to each other in the conveying direction of the substrate 2, and thus, compared with the dip coating method, it is possible to make the device small and simple, and to reduce the amount of the coating liquid C, thereby achieving cost reduction.

[0094] <Second Embodiment>

[0095] Reference Figure 6 The coating device 20 of the second embodiment will be described. In the following description, there are cases where the same reference numerals are assigned to the same structures as those of the above-described embodiments and detailed description is omitted.

[0096] In the present embodiment, the width direction one side 2c of the substrate 2 is set as the specific portion P. On the other hand, the width direction other side 2d of the substrate 2 is set as the non-specific portion Q.

[0097] In the present embodiment, the coating liquid C is also applied to the width direction one side 2e of the substrate 2, and the coating film F is formed. Here, by making the length dimension LI of each block 21, 22 sufficiently large with respect to the thickness dimension t of the substrate 2, the coating liquid C is sufficiently wound around the width direction one side 2e of the substrate 2.

[0098] For example, in the coating method using a slit die, it is difficult to apply the coating liquid C to the side surface 2e of the substrate 2. Therefore, the coating device 20 of the present embodiment is advantageous with respect to the slit die in terms of being able to apply the coating liquid C to the side surface 2e of the substrate 2.

[0099] <Third Embodiment>

[0100] ReferenceFigure 7 The coating device 20 of the third embodiment will be described. In the following description, there are cases where the same reference numerals are assigned to the same structures as those of the above-described embodiments and detailed description is omitted.

[0101] In the present embodiment, the width dimension B of the substrate 2 is smaller than the width dimension (width dimension L2 of the liquid pool portion 23) of each block 21, 22. Further, the entire width direction of the substrate 2 is set as the specific portion P, and the non-specific portion Q is not provided. That is, the coating liquid C is applied to both surfaces of the entire width direction of the substrate 2, and the coating film F is formed (full-surface coating).

[0102] As such, it is not necessary that a part of the width direction of the substrate 2 protrudes from the outlet 29 to the outside of the liquid pool portion 23.

[0103] In the present embodiment, the coating liquid C is also applied to the side surface 2e of both sides in the width direction of the substrate 2, and the coating film F is formed.

[0104] <Fourth Embodiment>

[0105] Reference Figure 8 , 9 The coating device 20 of the fourth embodiment will be described. In the following description, there are cases where the same reference numerals are assigned to the same structures as those of the above-described embodiments and detailed description is omitted. Note that, Figure 9 is Figure 8 IX-IX cross-sectional view in FIG. 1.

[0106] In the present embodiment, the first block 21 and the second block 22 are each provided with a plurality of coating liquid supply ports 30 on a surface facing the liquid pool portion 23. Each coating liquid supply port 30 is for supplying the coating liquid C to the liquid pool portion 23, and each coating liquid supply port 30 communicates with the supply pump 41 via a supply path 42.

[0107] In the present embodiment, each coating liquid supply port 30 is a circular hole. The number of coating liquid supply ports 30 provided to each block 21, 22 is equal to each other. Further, each coating liquid supply port 30 faces each other in the thickness direction across the liquid pool portion 23.

[0108] According to the present embodiment, the coating liquid C is supplied from the first block 21 and the second block 22 to the liquid pool portion 23 in a manner that faces each other in the thickness direction of the substrate 2, and thus the substrate 2 can be restricted to the vicinity of the center in the thickness direction of the liquid pool portion 23 by the hydraulic pressure at that time. Thereby, the coating liquid C can be stably and uniformly applied to both surfaces of the substrate 2, and thus a high-quality coating film F can be formed on both surfaces of the substrate 2. Further, by restricting the substrate 2 to the vicinity of the center in the thickness direction of the liquid pool portion 23, the contact of the substrate 2 with each block 21, 22 can be suppressed, and thus the damage of the coating film F formed on both surfaces of the substrate 2 can be prevented.

[0109] <5th Embodiment>

[0110] Reference Figure 10 The coating device 20 of the 5th embodiment will be described. In the following description, there are cases where the same reference signs are given to the same structures as those of the above embodiments and detailed description is omitted.

[0111] In the present embodiment, each coating liquid supply port 30 is an elliptical long hole extending in the long side direction of each block 21, 22 (the transport direction of the substrate 2). The width of each coating liquid supply port (long hole) 30 is preferably, for example, 1 mm or more. Other structures are the same as those of the 4th embodiment.

[0112] <6th Embodiment>

[0113] Reference Figure 11 The coating device 20 of the 6th embodiment will be described. In the following description, there are cases where the same reference signs are given to the same structures as those of the above embodiments and detailed description is omitted.

[0114] In the present embodiment, the thickness of the opening edge portion 31 of the discharge port 25 of the first block 21 and the second block 22 is smaller than that of other portions in the transport direction of each block 21, 22, thereby forming a wet spread suppression portion M that suppresses wet spread of the coating liquid C.

[0115] That is, the wet spread suppression portion M is formed by making the thickness dimension L3' of the opening edge portion 31 of the discharge port 25 of each block 21, 22 smaller than the thickness dimension L3 of other portions in the transport direction of each block 21, 22. The thickness dimension L3' is preferably as small as possible, and is preferably, for example, 5 mm or less, more preferably 1 mm or less.

[0116] When the substrate 2 is discharged from the discharge port 25, the coating liquid C applied to both faces of the substrate 2 sometimes wets and spreads on the face on the discharge port 25 side of each block 21, 22. Therefore, according to the present embodiment, by reducing the thickness dimension L3' of the opening edge portion 31 of the discharge port 25 of each block 21, 22, the area of the face on which the coating liquid C wets and spreads is reduced. Thus, it is possible to suppress the wet spread of the coating liquid C on the face on the discharge port 25 side of each block 21, 22, thereby stably and uniformly forming the coating film F on both faces of the substrate 2.

[0117] <7th Embodiment>

[0118] Reference Figure 12 The coating device 20 of the 7th embodiment will be described. In the following description, there are cases where the same reference signs are given to the same structures as those of the above embodiments and detailed description is omitted.

[0119] In the present embodiment, the gap (reservoir portion) 23 between the first block 21 and the second block 22 is wider on the inlet port 24 side than on the outlet port 25 side. Specifically, the gap size Hl at the inlet port 24 is larger than the gap size H2 at the outlet port 25.

[0120] According to the present embodiment, by increasing the gap size Hl at the inlet port 24, it is possible to suppress contact of the substrate 2 with each block 21, 22 at the inlet port 24. Further, by setting the gap size H2 at the outlet port 25 to a prescribed value, it is possible to determine the thickness of the coating film F formed on both faces of the substrate 2.

[0121] <eighth embodiment>

[0122] Reference Figure 13 The coating apparatus 20 of the eighth embodiment will be described. In the following description, there are cases in which the same reference numerals are assigned to structures common to the above-described embodiments and detailed description is omitted.

[0123] In the present embodiment, on the basis of the seventh embodiment, the gap (reservoir portion) 23 between the first block 21 and the second block 22 narrows as it approaches from the inlet port 24 side to the outlet port 25 side in the conveyance direction of the substrate 2. That is, the gap (reservoir portion) 23 between the first block 21 and the second block 22 is formed in a tapered shape.

[0124] According to the present embodiment, in addition to the effects of the seventh embodiment, it is possible to suppress stagnation of the coating liquid C in the reservoir portion (gap) 23.

[0125] <ninth embodiment>

[0126] Reference Figure 14 The coating apparatus 20 of the ninth embodiment will be described. In the following description, there are cases in which the same reference numerals are assigned to structures common to the above-described embodiments and detailed description is omitted.

[0127] In the present embodiment, a plurality of perforations 3 are formed in the substrate 2. The other structures are the same as in the first embodiment.

[0128] According to the present embodiment, the coating liquid C is also applied to the inner peripheral surface of the perforation 3 formed in the substrate 2, and the coating film F is formed. Here, by making the length dimension Ll of each block 21, 22 sufficiently large relative to the thickness dimension t of the substrate 2, the coating liquid C is caused to sufficiently wrap around the inner peripheral surface of the perforation 3.

[0129] <10th embodiment>

[0130] Reference Figure 15The coating device 20 of the tenth embodiment will be described. In the following description, there are cases in which the same reference numerals are assigned to the same structures as those of the above-described embodiments and detailed description is omitted.

[0131] In the present embodiment, the side surfaces of the substrate 2 on both sides in the width direction are formed in a zigzag shape, and a plurality of teeth 4 are provided. The other structures are the same as those of the third embodiment.

[0132] According to the present embodiment, the coating liquid C is also applied to the side surfaces on both sides in the conveyance direction of each tooth 4, and the coating film F is formed. Here, by making the length dimension LI of each block 21, 22 sufficiently large with respect to the thickness dimension t of the substrate 2, the coating liquid C is sufficiently wound around the side surfaces on both sides in the conveyance direction of each tooth 4.

[0133] <Eleventh Embodiment>

[0134] Reference Figure 16 The coating device 20 of the eleventh embodiment will be described. In the following description, there are cases in which the same reference numerals are assigned to the same structures as those of the above-described embodiments and detailed description is omitted.

[0135] In the present embodiment, only the side surface portion 26 on one side in the width direction includes the exposure port 29. Specifically, only the second side surface portion 26b on the other side in the width direction includes the exposure port 29. That is, the first side surface portion 26a on one side in the width direction is occluded.

[0136] In addition, the first side surface portion 26a faces downward in the vertical direction. On the other hand, the second side surface portion 26b faces upward in the vertical direction. That is, the exposure port 29 opens toward upward in the vertical direction.

[0137] According to the present embodiment, the number of exposure ports 29 is only one, and thus it is advantageous in suppressing the leakage of the coating liquid C from the liquid pool portion 23 compared to the above-described embodiments.

[0138] In addition, by making the exposure port 29 included in the second side surface portion 26b open toward upward in the vertical direction, it is possible to position the first side surface portion 26a below the liquid pool portion 23 in the vertical direction. Thus, it is possible to support the coating liquid C accumulated in the liquid pool portion 23 with the occluded first side surface portion 26a.

[0139] <Other Embodiments>

[0140] The present application has been described through preferred embodiments, but such description is not a limitation, and various modifications are of course possible.

[0141] The substrate 2 can also be shaped like, for example, a comb or a ladder. In the case of a comb shape, a coating liquid C is applied to the sides of each comb tooth in the conveying direction to form a coating film F. The spacing between the comb teeth is preferably 0.1 mm or more and 1 mm or less. Here, by making the length dimension L1 of each block 21, 22 sufficiently large relative to the thickness dimension t of the substrate 2, for example, more than 100 times, the coating liquid C is made to fully wrap around the sides of each comb tooth in the conveying direction. When the substrate 2 is in the shape of a ladder, the process is roughly the same as in the case of a comb shape.

[0142] Alternatively, a porous material can be used to form the substrate 2. In this case, the coating liquid C penetrates into the interior of each pore of the porous material to form a coating film F. By making the length dimension L1 of each block 21, 22 sufficiently large relative to the thickness dimension t of the substrate 2, for example, more than 500 times, the coating liquid C can be made to fully penetrate into the interior of each pore.

[0143] In the above embodiments, the conveying direction of the substrate 2 is generally consistent with the horizontal direction orthogonal to the vertical direction, but it is not limited to this. For example, the substrate 2 may also be conveyed from the vertical direction downward or from the vertical direction upward.

[0144] Alternatively, a supply pump 41 can be installed to introduce compressed air into the supply tank for pressurized liquid delivery.

[0145] In the fourth and fifth embodiments, the liquid supply ports 30 provided on each block 21, 22 are positioned opposite each other in the thickness direction across the liquid accumulation portion 23 (see reference). Figure 8 However, this is not the only possibility. Each liquid supply port 30 may also be located at a position that is offset from each other in the conveying direction and the width direction.

[0146] In the sixth embodiment, the wetting expansion inhibition section M is formed by making the thickness dimension L3' of the opening edge 31 of the discharge port 25 of each block 21, 22 smaller than the thickness dimension L3 of other parts of each block 21, 22 in the conveying direction, but it is not limited to this. The wetting expansion inhibition section M can also be formed, for example, by controlling the wettability of the surface on the discharge port 25 side of each block 21, 22. As a method for controlling wettability, there are methods for controlling surface roughness, methods for forming a film using a material with low affinity for the coating liquid C, methods for using fluorinated resins such as PTFE, etc.

[0147] In the above embodiment, the coating apparatus 20 is used to coat both sides of the substrate 2, which is continuously conveyed by a roll-to-roll method, with coating liquid C, but it is not limited to this. For example, the coating apparatus 20 can also be used to coat both sides of a glass substrate conveyed by a belt conveyor.

[0148] The coating method of the present application uses the coating device 20 of the above-described embodiment, passes the substrate 2 through the coating device 20 while protruding a part in the width direction of the substrate 2 from the outlet 29 to the outside of the liquid pool 23, and thereby can apply the coating liquid C to both surfaces of the specific part P in the width direction of the substrate 2.

[0149] [Example]

[0150] [Setting Conditions]

[0151] (Example)

[0152] As the substrate 2, SUS304 material having a thickness of 0.1 mm was used.

[0153] As the coating liquid C, a conductive paste having a viscosity η of about 100 Pa s was used. The viscosity η of the coating liquid C was measured using a rotational viscometer (Thermo Scientific Mars40, manufactured by HAAKE). Note that the measurement conditions of the viscosity η were set to a diameter of the workbench of 20 mm, a diameter of the probe of 20 mm, an angle of 1°, a measurement interval of 0.05 mm, a shear rate of 1 / second, and a measurement temperature of 25°C.

[0154] The coating device 20 of the first embodiment (refer to Figures 1 to 5 ) was used. Specifically, the coating device 20 used a benchtop coater (mini labo, manufactured by Koken Seiki). The first block 21 and the second block 22 were formed of SUS304 material. The length dimension LI of each block 21, 22 was set to 40 mm, the width dimension L2 of each block 21, 22 was set to 50 mm, and the thickness dimension L3 of each block 21, 22 was set to 10 mm. In the center of the width direction of each block 21, 22, three circular supply ports each having a diameter of 2 mm were arranged at intervals of 10 mm in the conveyance direction.

[0155] As the supply pump 41, a Mono pump (3HMC010F, manufactured by Hyosung Equipment) was used. The unwinding-side torque and the winding-side torque of the substrate supply device 10 were each set to 60 N m.

[0156] The gap dimension H between the first block 21 and the second block 22 was arbitrarily set using a shim. The coating speed (conveyance speed) was arbitrarily set.

[0157] After the coating film F was formed, a hot-air drying oven (DKM-400, manufactured by Dowa Science) was used to dry the film for 30 minutes at a set temperature of 200°C and a blade rotation speed of 500 rpm, and thereby a dried film was obtained.

[0158] (Comparative Example)

[0159] A conventional coating device different from the present application was used. The conditions of the coating liquid C and the substrate 2 were the same as in the example.

[0160] <Measurement conditions>

[0161] The film thickness of the coating film F was measured using a micrometer (manufactured by MITUTOYO). The film thickness was a value obtained by subtracting the thickness dimension t of the substrate 2 before the formation of the coating film F from the thickness dimension T of the substrate 2 after the formation of the coating film F (refer to FIG. 1). The film thickness was measured at five points at intervals of 5 mm in the coating direction (transport direction), and the average value of the film thickness was calculated using the measured values. The standard deviation 3σ was calculated using the measured values at the five points, and the film thickness deviation was a value obtained by dividing the standard deviation 3σ by the average value of the film thickness (expressed in percentage). As for the surface roughness, the arithmetic average roughness was measured using an ONESHOT 3D shape measuring machine (VR-3000, manufactured by Keyence). Figure 5

[0162] <Measurement results>

[0163] (Example 1)

[0164] The gap size H was set to 0.2 mm, and the coating speed (transport speed) was set to 0.2 m per minute. The average film thickness was 7.6 μm, the film thickness deviation was 28%, and the surface roughness was 2.5 μm, and a good result was obtained.

[0165] (Example 2)

[0166] The gap size H was set to 0.2 mm, and the coating speed (transport speed) was set to 0.5 m per minute. The average film thickness was 14.8 μm, the film thickness deviation was 29%, and the surface roughness was 2.0 μm, and a good result was obtained.

[0167] (Example 3)

[0168] The gap size H was set to 0.2 mm, and the coating speed (transport speed) was set to 1 m per minute. The average film thickness was 17.9 μm, the film thickness deviation was 29%, and the surface roughness was 2.8 μm, and a good result was obtained.

[0169] (Example 4)

[0170] A notch portion was formed in the substrate 2 with respect to Example 1. The other conditions were the same as in Example 1. The coating film F was also formed on the side surface of the notch portion of the substrate 2.

[0171] (Comparative Example 1)

[0172] ​Roller transfer was used. The gap between the roller and the substrate 2 was set to 0 mm, and the coating speed (transport speed) was set to 1 m / min. The average film thickness was 7.2 μm, the film thickness deviation was 65%, and the surface roughness was 3.8 μm, which were worse than those of Examples 1 to 4.

[0173] (Comparative Example 2)

[0174] A slit die was used. The gap between the slit die and the substrate 2 was set to 0.05 mm, and the coating speed (transport speed) was set to 1 m / min. The average film thickness was 15.0 μm, the film thickness deviation was 31%, and the surface roughness was 3.3 μm, which were good results compared to Comparative Example 1. However, if the film thickness is further reduced, coating omission occurs, and thus it is difficult to form a uniform coating film.

[0175] (Comparative Example 3)

[0176] In Comparative Example 2, a cut portion was formed in the substrate 2. The other conditions were the same as those of Comparative Example 2. The coating film F was not formed on the side surface of the cut portion of the substrate 2.

[0177] Industrial Applicability

[0178] The present application can be applied to a coating apparatus and a coating method, and thus is extremely useful and has high industrial applicability.

Claims

1. A coating device that applies a coating liquid to both surfaces of a sheet-like substrate being conveyed, wherein the coating device comprises: a pair of blocks that oppose each other in a thickness direction of the substrate; and a pool portion that is formed in a gap between the pair of blocks to store the coating liquid and through which the substrate passes, the pool portion including: a guide inlet that opens on an upstream side in a conveying direction of the substrate and guides the substrate in; a discharge outlet that opens on a downstream side in the conveying direction and discharges the substrate; and side portions that are respectively located on both sides in a width direction that intersects the conveying direction, the side portion on at least one side in the width direction includes a reveal opening that opens in a range from the guide inlet to the discharge outlet, a portion of the substrate in the width direction is able to protrude from the reveal opening to an outside of the pool portion, each of the blocks is formed in a substantially cuboid shape, and each of the blocks is disposed with a length direction thereof along the conveying direction of the substrate.

2. The coating device according to claim 1, wherein the side portions on both sides in the width direction respectively include the reveal opening.

3. The coating device according to claim 1, wherein the side portion on only one side in the width direction includes the reveal opening, and the reveal opening opens toward an upper side in a vertical direction.

4. The coating device according to any one of claims 1 to 3, wherein the pair of blocks are respectively provided with a coating liquid supply port for supplying the coating liquid to the pool portion on a surface facing the pool portion, and each of the coating liquid supply ports opposes the other across the pool portion.

5. The coating device according to any one of claims 1 to 3, wherein the gap on the guide inlet side is wider than the gap on the discharge outlet side.

6. The coating device according to claim 5, wherein the gap narrows as it trends from the guide inlet side toward the discharge outlet side in the conveying direction.

7. The coating device according to any one of claims 1 to 3, wherein a thickness of an opening edge portion of the discharge outlet of the pair of blocks is smaller than a thickness of other portions of the pair of blocks in the conveying direction, thereby forming a wetting spread suppression portion that suppresses wetting spread of the coating liquid.

8. The coating device according to any one of claims 1 to 3, wherein the gap is 0.1 mm or more and 1 mm or less.

9. The coating device according to any one of claims 1 to 3, wherein each of the blocks is disposed in a symmetrical manner in the thickness direction of the substrate.

10. A coating method in which the coating device according to any one of claims 1 to 9 is used to pass the substrate while a portion of the substrate in the width direction protrudes from the reveal opening to an outside of the pool portion, thereby applying the coating liquid to both surfaces of a specific portion in the width direction of the substrate. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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