JP2022185728A - Coating device and coating method - Google Patents

Abstract

To provide a coating device for forming coated films having uniform thickness onto both surfaces of a base material even when the base material is not flat.SOLUTION: A coating device 1 coats a coating liquid C to both surfaces of a sheet-like base material 2 to be conveyed. The coating device 1 includes a liquid reservoir part 11 for accumulating the coating liquid C therein and passing the base material 2 therethrough, and a pair of wiping mechanisms 23 which is provided so as to sandwich the base material 2 from both sides in the thickness direction, and wipes the coating liquid C coated to both surfaces of the base material 2 with a plurality of wipers 20. The wipers 20 are provided in a direction crossing a conveyance direction of the base material 2 in the thickness direction. The wipers 20 are deformably configured so as to follow the base material 2. The pair of wiping mechanisms 23 is configured to level the coating liquid C coated onto both surfaces of the base material 2 by making the plurality of wipers 20 arranged along both of the surfaces of the base material 2.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a coating apparatus and a coating method.

2. Description of the Related Art Various techniques are known for coating apparatuses for forming coating films on both sides of a sheet-like substrate conveyed by a roll-to-roll method.

For example, in a coating apparatus applied to a dip coating method, first, a continuously conveyed long sheet-like substrate is vertically lowered and immersed in an immersion tank containing a coating liquid. Thereby, the coating liquid is applied to both surfaces of the substrate. After that, the direction of the base material is changed by a sink roll placed in the immersion bath, and while the base material is lifted in the vertical direction, the base material is wiped by a pair of gas wiping nozzles or the like arranged on both sides in the thickness direction of the base material. Remove excess coating fluid on both sides of the Thereby, a coating film having a constant thickness is formed on both surfaces of the substrate. In the roll-to-roll method, warpage deformation is likely to occur in the base material when the direction of the base material is changed by a sink roll.

Patent Literature 1 discloses a method for correcting warpage deformation of a steel strip conveyed by the roll-to-roll method. In this method, a pair of supporting rolls sandwiching the steel strip are arranged above (downstream) the sink rolls to physically correct the warp deformation of the base material.

JP 2008-280584 A

If the base material is warped and deformed, the jetted gas flow becomes non-uniform on the surface of the base material when the excess coating liquid on both sides of the base material is removed by the gas wiping nozzle. There is a problem that the thickness of the coating film formed on both sides becomes uneven.

Therefore, it is conceivable to physically correct the warp deformation itself of the base material to flatten the base material by using the supporting roll according to Patent Document 1. However, although the method of correcting warp deformation using a supporting roll is effective for relatively wide substrates such as steel strips, it is difficult to apply to narrow substrates. That is, the narrower the width of the base material, the smaller the contact area between the base material and the supporting roll, making it more difficult to correct the warp deformation of the base material and flatten the base material. Therefore, the method of correcting warp deformation using a supporting roll can be applied only to a special base material such as a steel strip, and cannot be applied to all base materials.

For this reason, it is usually difficult to form a coating film having a uniform thickness on both sides of the substrate when the substrate is warped and deformed so that the substrate is no longer flat. The same applies when the substrate is not flat because it has openings such as holes or cutouts.

The present disclosure has been made in view of such points, and the object thereof is to form a coating film with a uniform thickness on both sides of a conveyed substrate even if the substrate is not flat. To provide a coating apparatus capable of

A coating apparatus according to the present disclosure is a coating apparatus that applies a coating liquid to both surfaces of a conveyed sheet-like substrate, and includes a liquid pool portion in which the coating liquid is accumulated and the substrate passes through. a pair of wiping mechanisms provided so as to sandwich the base material from both sides in the thickness direction thereof, and for wiping off the coating liquid applied to both surfaces of the base material with a plurality of wipers, the wipers having a thickness of The pair of wiping mechanisms are provided along a direction that intersects the conveying direction of the base material and are configured to be deformable so as to follow the base material. It is configured to even out the coating liquid applied to both sides of the base material along both sides of the base material.

In the coating method according to the present disclosure, when the base material is passed through the liquid reservoir using the coating device, both surfaces of the base material are coated by the plurality of wipers in the pair of wiping mechanisms. Level the above coating liquid.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a coating apparatus capable of forming a coating film with a uniform thickness on both sides of a transported substrate even if the substrate is not flat.

FIG. 1 is a front view showing a coating device according to a first embodiment of the present disclosure; FIG. FIG. 2 is a front view showing the wiping mechanism according to the first embodiment; FIG. FIG. 3 is a plan view showing the wiping mechanism according to the first embodiment. FIG. 4 is an enlarged front view showing an enlarged front end portion of the elastic wiper according to the first embodiment. FIG. 5 is a plan view showing a wiping mechanism according to the second embodiment. FIG. 6 is a plan view showing a wiping mechanism according to the third embodiment. FIG. 7 is a plan view showing a wiping mechanism according to the fourth embodiment. FIG. 8 is a plan view showing a wiping mechanism according to the fifth embodiment. FIG. 9 is a front view showing a wiping mechanism according to the sixth embodiment. FIG. 10 is an enlarged front view showing an enlarged front end portion of the elastic wiper according to the seventh embodiment. FIG. 11 is an enlarged front view showing an enlarged front end portion of the elastic wiper according to the eighth embodiment. FIG. 12 is a front view showing a coating device according to the ninth embodiment. FIG. 13 is a front view showing a coating device according to the tenth embodiment. FIG. 14 is a front view showing a coating device according to the eleventh embodiment. FIG. 15 is a side view showing a coating device according to the eleventh embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. The following description of preferred embodiments is merely exemplary in nature and is in no way intended to limit the disclosure, its applicability or its uses.

<First Embodiment>
(basic configuration)
FIG. 1 schematically shows a coating device 1 according to a first embodiment of the present disclosure. The coating apparatus 1 is applied to a dip coating method, and applies a coating liquid C to both surfaces of a base material 2 that is continuously conveyed by a roll-to-roll method to continuously form a coating film on both surfaces of the base material 2. to form The base material 2 is formed in a long sheet shape. Examples of the substrate 2 include metal foil, resin film, woven fabric, non-woven fabric, and paper. The thickness dimension of the substrate 2 not including the coating film is, for example, 1 mm or less.

The dip coating method will be briefly explained. The coating apparatus 1 includes a liquid reservoir 11 formed so that the coating liquid C is accumulated in an immersion tank (sink) 10 . The substrate 2 is continuously transported with its longitudinal direction as the transport direction. The transport direction of the substrate 2 includes a vertical component (indicated by F). Specifically, the substrate 2 is obliquely conveyed from the vertical upper side to the vertical lower side and immersed in the liquid pool 11 . On the way, the base material 2 changes its direction by a sink roll 3 provided in the liquid pool 11 (inside the immersion tank 10 ), is conveyed straight from the bottom in the vertical direction to the top in the vertical direction, and is discharged from the liquid pool 11 . Ejected.

As the base material 2 passes through the liquid reservoir 11 in this manner, the coating liquid C is applied to both surfaces of the base material 2 to form coating films on both surfaces of the base material 2 . The substrate 2 on both sides of which the coating film has been formed by the coating device 1 is dried in a drying oven (not shown) to remove volatile components contained in the coating film.

The coating liquid C is preferably in the form of a paste or a slurry. For example, the coating liquid C having a viscosity η of 1 mPa·s or more can be applied to both surfaces of the substrate 2 . Further, for example, when a coating liquid C having a viscosity η of 1 Pa·s to 1000 Pa·s is applied, it is possible to form a smooth coating film on both surfaces of the substrate 2, which is preferable.

The coating liquid C includes, for example, silica, low-melting glass, insulator materials containing metal oxide particles such as alumina and titanium oxide, metal particles such as solder, copper, silver, and metal-coated particles, and lithium nickel oxide. , lithium manganate, lithium cobaltate, a conductive material containing carbon or the like, a dye, or the like can be used.

The coating device 1 according to this embodiment includes a pair of wiping mechanisms 23 and a pair of blocks 30 . Both the pair of wiping mechanisms 23 and the pair of blocks 30 are arranged near the liquid surface 11a in the liquid pool portion 11 . Both the pair of wiping mechanisms 23 and the pair of blocks 30 are immersed in the liquid reservoir 11 (coating liquid C). A pair of wiping mechanisms 23 are provided so as to sandwich the substrate 2 from both sides in the thickness direction, and wipe off the coating liquid C applied to both surfaces of the substrate 2 with a plurality of wipers 20 . The pair of wiping mechanisms 23 includes a plurality of wipers 20 arranged in the conveying direction of the substrate 2 on each side of the substrate 2 in the thickness direction.

Each wiper 20 is configured to be deformable so as to follow the shape of the base material 2 and has a certain degree of flexibility. Each wiper 20 is made of an elastic material (hereinafter referred to as "elastic wiper 20"). Specifically, the elastic wiper 20 is made of a thermosetting elastomer (rubber).

The pair of blocks 30 are arranged on both sides in the thickness direction of the base material 2 conveyed vertically upward. The pair of blocks 30 are spaced apart from each other in the thickness direction of the base material 2 and face each other in the thickness direction of the base material 2 . That is, the base material 2 passes through the gap 33 between the pair of blocks 30 . Each block 30 is formed in a substantially rectangular parallelepiped shape, and is arranged such that its longitudinal direction is along the conveying direction (vertical direction) of the base material 2 .

The gap 33 is composed of the base material introduction port 31 that opens upstream (vertical direction lower side) in the conveying direction of the base material 2 and the base material discharge port that opens downstream (vertical direction upper side) in the conveying direction of the base material 2. 32 and The base material introduction port 31 and the base material discharge port 32 face each other in the transport direction. The base material 2 is introduced from the base material introduction port 31 , passed through the gap 33 , and discharged from the base material discharge port 32 . The substrate discharge port 32 is arranged at the same position as the liquid surface 11a of the liquid reservoir 11 in the vertical direction.

The gap dimension between the pair of blocks 30 is larger than the thickness dimension (for example, 0.1 mm or less) of the base material 2 so that the base material 2 can pass through, and is, for example, about 0.1 mm to 1 mm.

A pair of wiping mechanisms 23 are interposed between the base material 2 and a pair of blocks 30 . Specifically, each elastic wiper 20 is fixed to an inner surface 30 a of the pair of blocks 30 facing the substrate 2 .

The configuration of the pair of wiping mechanisms 23 and each elastic wiper 20 will be described with reference to FIGS. 2-4. 2 and 3 show a pair of wiping mechanisms 23 according to this embodiment, where FIG. 2 is a front view and FIG. 3 is a plan view (view from arrow III). FIG. 4 shows the distal end portion 20b of the elastic wiper 20 in an enlarged manner. In FIG. 3, a pair of blocks 30 are indicated by two-dot chain lines.

As shown in FIG. 2, the sum of the length dimensions of the elastic wipers 20 on both sides in the thickness direction of the base material 2 is larger than the gap dimension between the pair of blocks 30 .

As shown in FIG. 2 , the elastic wipers 20 on both sides in the thickness direction of the base material 2 face each other in the thickness direction of the base material 2 with the base material 2 interposed therebetween. Specifically, the base end portions 20a of the respective elastic wipers 20 on both sides in the thickness direction of the base material 2 face each other in the thickness direction of the base material 2 with the base material 2 therebetween. Further, tip portions 20b of the respective elastic wipers 20 on both sides in the thickness direction of the base material 2 face each other in the thickness direction of the base material 2 with the base material 2 interposed therebetween.

As shown in FIG. 3, the elastic wiper 20 extends in a direction intersecting the conveying direction of the base material 2, specifically, along a direction orthogonal to the direction of conveyance of the base material 2 (the width direction of the base material 2). are provided. More specifically, the elastic wiper 20 linearly extends along a direction perpendicular to the conveying direction of the substrate 2 (the width direction of the substrate 2 ) when viewed in the thickness direction of the substrate 2 .

As shown in FIG. 4, the tip portion 20b of the elastic wiper 20 is formed in a square shape, specifically a square shape. The elastic wiper 20 abuts on the substrate 2 at a side portion 20c (more specifically, near the edge of the side portion 20c) of the tip portion 20b.

The pair of wiping mechanisms 23 is configured to level the coating liquid C applied to both surfaces of the base material 2 by the plurality of wipers 20 running along both surfaces of the base material 2 .

(Effect)
According to this embodiment, the plurality of wipers 20 follow the shape of the base material 2 and follow both sides of the base material 2, thereby leveling the coating liquid C applied on both sides of the base material 2. . Thereby, even if the base material 2 is not flat, it is possible to form a coating film with a uniform thickness on both sides of the base material 2 being conveyed.

In particular, in this embodiment, the base material 2 may warp and deform (for example, about 0.2 μm to 5 μm) due to the direction change by the sink roll 3 . Even if the base material 2 is warped and deformed so that it is no longer flat, the plurality of wipers 20 follow the shape of the base material 2 and follow the shape of the base material 2 along both sides of the base material 2 . By leveling the coating liquid C applied to the substrate 2, a coating film having a uniform thickness can be formed on both surfaces of the substrate 2.

In some cases, it is also possible to correct the warpage deformation of the base material 2 by pressing the base material 2 from both sides in the thickness direction with the elastic wipers 20 .

The substrate 2 may not be flat due to openings in the substrate 2, such as openings in the substrate 2 or formation of the substrate 2 in a comb shape or a ladder shape. Even in the case where the base material 2 is provided with openings in this way, the plurality of wipers 20 follow the shape of the base material 2 and also follow the side surfaces of the openings of the base material 2 . As a result, the coating liquid C applied to the side surface of the opening of the base material 2 can be leveled to form a coating film having a uniform thickness on the side surface of the opening of the base material 2 as well. The same applies when the base material 2 is made of mesh material, punching metal, porous material, or the like.

Since the elastic wiper 20 is made of an elastic material, when the base material 2 is provided with an opening, the elastic wiper 20 bends along the surface of the base material 2 and also closes to the opening, that is, the base material 2 . In a space where there is no , it tries to return to its original shape. This makes it easier for the elastic wiper 20 to follow the side surface of the opening of the substrate 2 .

Since the plurality of elastic wipers 20 are arranged along the conveying direction of the base material 2, both surfaces of the base material 2 can be continuously leveled by the plurality of elastic wipers 20 as the base material 2 is conveyed. can.

Since the elastic wiper 20 extends linearly along the direction perpendicular to the conveying direction of the base material 2 (the width direction of the base material 2), the same portion on both sides of the base material 2 can be wiped in the conveying direction of the base material 2. It can be continuously leveled by a plurality of resilient wipers 20 arranged in rows.

Since the elastic wipers 20 on both sides in the thickness direction of the base material 2 face each other through the base material 2, the position in the thickness direction of the base material 2 passing through the gap 33 between the pair of blocks 30 can be kept constant. is advantageous.

Since the tip portion 20b of the elastic wiper 20 is formed in a rectangular shape, the side portion 20c of the tip portion 20b of the elastic wiper 20 comes into contact with the surface of the base material 2. As shown in FIG. As a result, the contact area between the elastic wiper 20 and the surface of the base material 2 is increased, so that the coating liquid C applied to the surface of the base material 2 can be wiped off sufficiently.

By fixing the elastic wiper 20 to the inner surfaces 30 a of the pair of blocks 30 facing the substrate 2 , the elastic wiper 20 can be easily arranged in the liquid pool portion 11 .

Since the substrate outlets 32 of the pair of blocks 30 are arranged at the same position as the liquid surface 11a of the liquid reservoir 11 in the vertical direction, the substrate discharged from the liquid reservoir 11 through the substrate outlets 32 It is possible to prevent the coating liquid C from being newly applied to the material 2 .

<Second embodiment>
A coating device 1 according to a second embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In the present embodiment, the elastic wiper 20 vibrates in the direction in which the base material 2 is conveyed along a direction intersecting, more specifically, a direction orthogonal to the direction in which the base material 2 is conveyed when viewed in the thickness direction of the base material 2 . while extending in waves. Other configurations are the same as those of the first embodiment.

According to this embodiment, unevenness is formed on the elastic wiper 20 when viewed in the thickness direction of the base material 2 . As a result, the elastic wiper 20 is formed with a region A where the coating liquid C tends to accumulate. By arranging the opening B of the substrate 2 so as to correspond to the area A of the elastic wiper 20 where the coating liquid C tends to accumulate, the coating liquid C is sufficiently sent to the side surface of the opening B, and the opening B A coating film having a uniform thickness can also be formed on the side surface of the .

<Third Embodiment>
A coating device 1 according to a third embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In this embodiment, the elastic wiper 20 is formed like a brush. More specifically, when viewed in the thickness direction of the base material 2, a plurality of fine elastic wipers 20 are spaced apart from each other in a direction intersecting the conveying direction of the base material 2, specifically along a direction orthogonal to the direction of conveyance. arranged in a straight line. Other configurations are the same as those of the first embodiment.

According to this embodiment, when a large number of openings are provided in the substrate 2, the large number of fine elastic wipers 20 are used to sufficiently feed the coating liquid C to the side surfaces of the large number of openings in the substrate 2. A coating film having a uniform thickness can be sufficiently formed on the side surfaces of the numerous openings of the material 2 as well.

<Fourth Embodiment>
A coating device 1 according to a fourth embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In the present embodiment, the plurality of elastic wipers 20 are arranged in a zigzag pattern along a direction intersecting the conveying direction of the base material 2, specifically along a direction orthogonal to the conveying direction of the base material 2 when viewed in the thickness direction of the base material 2. As shown in FIG. Other configurations are the same as those of the first embodiment. According to the present embodiment, the coating liquid C applied to the region D where the elastic wiper 20 is not present moves forward in the transport direction as the base material 2 is transported. is wiped off by an elastic wiper 20 of .

<Fifth Embodiment>
A coating device 1 according to a fifth embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In the present embodiment, the elastic wiper 20 extends linearly along a direction inclined with respect to the conveying direction of the substrate 2 when viewed in the thickness direction of the substrate 2 . In addition, the inclination directions of the plurality of elastic wipers 20 arranged in the conveying direction of the base material 2 may be reversed alternately. Other configurations are the same as those of the first embodiment.

According to this embodiment, the flow direction of the coating liquid C can be inclined with respect to the conveying direction of the substrate 2 . Thereby, the coating liquid C can be sufficiently sent to the side surface of the base material 2 itself and the side surface of the opening of the base material 2 .

<Sixth Embodiment>
A coating device 1 according to a sixth embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In this embodiment, the elastic wipers 20 on both sides in the thickness direction of the base material 2 are alternately arranged in the conveying direction of the base material 2 . Other configurations are the same as those of the first embodiment.

According to this embodiment, the substrate 2 to be transported is alternately pushed by the elastic wipers 20 from the front side and the back side. For this reason, the conveyed base material 2 is warped and deformed alternately on the front surface side and the back surface side. This makes it easier for the next elastic wiper 20 to come into contact with the surface of the substrate 2 opposite to the surface pushed by the elastic wiper 20 .

<Seventh embodiment>
A coating device 1 according to a seventh embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In this embodiment, the tip portion 20b of the elastic wiper 20 is formed in an arc shape. Other configurations are the same as those of the first embodiment.

According to this embodiment, the resilient wiper 20 contacts the surface of the substrate 2 at the arc portion 20d of the tip portion 20b. As a result, the contact area between the elastic wiper 20 and the surface of the base material 2 is smaller than that of the first embodiment (square shape, side portion 20c). can be made smaller. Therefore, it is advantageous in suppressing breakage of the base material 2 .

<Eighth embodiment>
A coating device 1 according to an eighth embodiment will be described with reference to FIG. 11 . In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In this embodiment, the tip portion 20b of the elastic wiper 20 is formed in a pointed shape that tapers toward the tip side. Other configurations are the same as those of the first embodiment.

According to this embodiment, the resilient wiper 20 slightly contacts the surface of the substrate 2 at the point 2e at the tip 20b. As a result, the contact area between the elastic wiper 20 and the surface of the substrate 2 is smaller than in the first embodiment (square shape, side portion 20c) and the seventh embodiment (arc shape, arc portion 20d). Therefore, the force that the base material 2 receives from the elastic wiper 20 can be further reduced. Further, the elastic wiper 20 can easily follow the side surface of the opening of the base material 2 by inserting the pointed portion 2 e of the elastic wiper 20 into the opening of the base material 2 .

<Ninth Embodiment>
A coating device 1 according to the ninth embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In this embodiment, the pair of wiping mechanisms 23 includes elastic wipers 21 located above the liquid surface 11a of the liquid pool 11 in the vertical direction on both sides in the thickness direction of the base material 2 . Other configurations are the same as those of the first embodiment.

According to the present embodiment, even after the base material 2 is discharged from the liquid reservoir 11 through the base material outlets 32 of the pair of blocks 30, at a position above the liquid surface 11a of the liquid reservoir 11, The coating liquid C on both surfaces of the substrate 2 can be leveled by the elastic wiper 21 .

<Tenth Embodiment>
A coating device 1 according to a tenth embodiment will be described with reference to FIG. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In this embodiment, the pair of wiping mechanisms 23 includes block wipers 22 on each side of the substrate 2 in the thickness direction. The block wipers 22 are provided at the base material outlets 32 of the pair of blocks 30 so as to sandwich the base material 2 from both sides in the thickness direction. The block wiper 22 is configured such that the diameter (gap) in the thickness direction of the substrate outlet 32 is smaller than the thickness of the substrate 2 . The block wiper 22 is made of an elastic material. Other configurations are the same as those of the first embodiment.

According to this embodiment, the coating liquid C on both surfaces of the conveyed substrate 2 is reliably wiped off by the block wiper 22 at the substrate discharge port 32 (liquid surface 11a of the liquid pool portion 11).

<Eleventh Embodiment>
A coating apparatus 1 according to an eleventh embodiment will be described with reference to FIGS. In the following description, configurations similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description may be omitted.

In this embodiment, the coating device 1 further includes a coating liquid supply unit 39 that supplies the coating liquid C to the gap 33 between the pair of blocks 30 . In the present embodiment, unlike the above-described embodiment, the liquid pooling portion is formed so that the coating liquid C is pooled in the gap 33 by the coating liquid supply section 39 instead of being stored in the immersion tank 10 (hereinafter referred to as " referred to as a "liquid pooling portion 33").

The coating liquid supply section 39 includes a coating liquid supply port 35 , a coating liquid supply path 36 , a coating liquid supply pipe 37 , and a coating liquid supply pump 38 . The coating liquid supply port 35 is provided on the inner surface 30 a facing the liquid reservoir (gap) 33 in one block 30 . The coating liquid supply path 36 extends inside one of the blocks 30 and communicates with a coating liquid supply pump 38 via a coating liquid supply pipe 37 on the upstream side thereof, and a coating liquid supply port on the downstream side thereof. 35. The coating liquid supply pump 38 supplies the coating liquid C to the liquid reservoir (gap) 33 via the coating liquid supply pipe 37 , the coating liquid supply path 36 and the coating liquid supply port 35 .

The coating liquid supply pump 38 preferably employs, for example, a screw pump, a diaphragm pump, a syringe pump, a tube pump, or a mono pump capable of supplying a constant amount of liquid. Instead of the coating liquid supply pump 38, compressed air may be introduced into the supply tank to supply the liquid under pressure.

In the gap 33 between the pair of blocks 30 , exposure openings 34 are provided on both sides in the width direction crossing, specifically perpendicular to, the conveying direction of the base material 2 . The exposure port 34 is open from the substrate introduction port 31 to the substrate discharge port 32 in the conveying direction of the substrate 2 . A part of the substrate 2 in the width direction can protrude outside the liquid reservoir 33 through the exposure opening 34 . The width dimension of the pair of blocks 30 is smaller than the width dimension of the substrate 2 .

According to this embodiment, since the dipping tank 10 for forming the liquid pool portion 11 is not required, the size of the coating apparatus 1 can be reduced.

In addition, since the exposure port 34 is provided on at least one side in the width direction of the gap 33 between the pair of blocks 30 , a part of the substrate 2 in the width direction is exposed to the outside of the liquid pool portion 33 through the exposure port 34 . can be protruded. Thereby, it is possible to selectively form a coating film only on both surfaces of a specific portion (intermediate portion in the width direction in FIG. 15) of the transported substrate 2 in the width direction.

<Other embodiments>
Although the present disclosure has been described in terms of preferred embodiments, such descriptions are not intended to be limiting, and various modifications are of course possible.

Regarding the first embodiment (especially see FIG. 1), the base material outlet 32 of the pair of blocks 30 may be arranged above the liquid surface 11a of the liquid reservoir 11 in the vertical direction.

A pair of blocks 30 for fixing the elastic wiper 20 is not necessarily required. The elastic wiper 20 may be fixed to the wall surface of the immersion bath 10, for example.

One elastic wiper 20 may be provided on each side of the substrate 2 in the thickness direction.

The material of wiper 20 is not limited to an elastic body. It is sufficient that the wiper 20 as a whole is deformable so as to follow the shape of the substrate 2 . The wiper 20 may be, for example, a rigid material with a spring-loaded proximal end (support) 20a.

In the above embodiment, the coating device 1 is used to apply the coating liquid C to both surfaces of the substrate 2 that is continuously conveyed by the roll-to-roll method, but is not limited to this. The coating apparatus 1 may be used, for example, to apply the coating liquid C to both sides of a glass substrate conveyed by a belt conveyor.

In the coating method according to the present disclosure, when the coating device 1 is used to pass the substrate 2 through the liquid pools 11 and 33, the wipers 20 in the pair of wiping mechanisms 23 are used to wipe both surfaces of the substrate 2. The applied coating liquid C is leveled.

<Setting conditions>
(Example 1)
A SUS304 material having a thickness of 0.1 mm was used as the base material 2 .

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 rotary viscometer (Thermo Scientific Mars40, manufactured by HAAKE). The viscosity η was measured under conditions of a stage diameter of 20 mm, a probe diameter of 20 mm, an angle of 1°, a measurement gap of 0.05 mm, a shear rate of 1/sec, and a measurement temperature of 25°C.

A coating apparatus 1 (see FIGS. 1 to 4) according to the first embodiment was used. However, the distal end portion 20b of the elastic wiper 20 has a pointed shape (eighth embodiment, see FIG. 11). Each block 30 is made of SUS304 material. Each block 30 had a length dimension of 40 mm, a width dimension of 50 mm, and a thickness dimension of 10 mm. The elastic wiper 20 is made of silicone rubber.

The gap dimension of the gap 33 between the pair of blocks 30 was set to 0.2 mm. The coating speed (conveyance speed) was 0.2 m/min. The base material 2 was warped and deformed, and the amount of deformation was set to 0.002 mm between the center portion in the width direction and the end portions in the width direction.

After the coating film was formed, it was dried for 30 minutes using a hot air drying oven (DKM-400, manufactured by Yamato Scientific Co., Ltd.) at a set temperature of 200° C. and a fan speed of 500 rpm to obtain a dry film.

(Example 2)
A coating apparatus 1 (see FIGS. 14 and 15) according to the eleventh embodiment was used. Specifically, as the coating device 1, a desktop coating device (Minilab, manufactured by Yasui Seiki Co., Ltd.) was used. As the coating liquid supply pump 38, a mono pump (3HMC010F, manufactured by Hyoshin Equipment Co., Ltd.) was used. Other setting conditions are the same as in the first embodiment.

(Comparative example)
As a conventional coating apparatus different from the present disclosure, coating films were formed on both surfaces of a sheet-like substrate 2 conveyed by a general roll-to-roll method. Specifically, in the comparative example, the configuration of the coating device is the same as that in the first example except that the wiper 20 is not provided. Moreover, in the comparative example, the conditions of the coating liquid C and the substrate 2 are the same as those of the first and second examples.

<Measurement conditions>
The film thickness of the coating film was measured using a micrometer (manufactured by Mitutoyo). The film thickness was obtained by subtracting the thickness of the substrate 2 before forming the coating from the thickness of the substrate 2 after forming the coating. The film thickness average value was calculated from the measured values obtained by measuring the film thickness at 5 points in the coating direction (conveyance direction) at intervals of 5 mm. The film thickness variation was obtained by calculating the standard deviation 3σ from the measured values at five points and dividing it by the film thickness average value (displayed as a percentage). Surface roughness was measured by arithmetic mean roughness using a one-shot 3D shape measuring machine (VR-3200, manufactured by Keyence).

<Measurement result>
(Example 1)
The average film thickness was 27.6 μm, the film thickness variation was 32%, and the surface roughness was 7.4 μm.

(Example 2)
The average film thickness was 13.2 μm, the film thickness variation was 22%, and the surface roughness was 5.4 μm.

(Comparative example)
The average film thickness was 50.4 μm, the film thickness variation was 35%, and the surface roughness was 10.3 μm.

INDUSTRIAL APPLICABILITY The present disclosure is applicable to a coating apparatus and a coating method, and thus is extremely useful and has high industrial applicability.

F Conveying direction (vertical direction)
C Coating liquid 1 Coating device 2 Base material 10 Immersion tank 11 Liquid reservoir 11a Liquid surface 20 Wiper 21 Wiper 22 Block wiper 23 Pair of wiping mechanisms 30 Pair of blocks 30a Inner surface 31 Base material inlet 32 Base material outlet 33 Gap (liquid reservoir)
34 exposure port 39 coating liquid supply unit

Claims (20)

A coating device that applies a coating liquid to both sides of a conveyed sheet-like substrate,
a liquid reservoir in which the coating liquid is accumulated and through which the substrate passes;
a pair of wiping mechanisms provided so as to sandwich the base material from both sides in the thickness direction thereof, and wiping the coating liquid applied to both surfaces of the base material with a plurality of wipers;
The wiper is provided along a direction that intersects the conveying direction of the base material when viewed in the thickness direction, and is configured to be deformable so as to follow the base material,
The coating device, wherein the pair of wiping mechanisms is configured to level the coating liquid applied to both surfaces of the substrate by the plurality of wipers extending along both surfaces of the substrate. In the coating apparatus according to claim 1,
The coating device, wherein the wiper is made of an elastic material. In the coating device according to claim 1 or 2,
The coating device, wherein each of the pair of wiping mechanisms includes a plurality of the wipers arranged along the conveying direction. In the coating apparatus according to any one of claims 1 to 3,
The coating device, wherein the wiper extends linearly along a direction perpendicular to the conveying direction when viewed in the thickness direction. In the coating apparatus according to any one of claims 1 to 3,
The coating device, wherein the wiper extends linearly along a direction inclined with respect to the conveying direction when viewed in the thickness direction. In the coating apparatus according to any one of claims 1 to 3,
The coating apparatus, wherein the wiper extends in a wavy shape while vibrating in the transport direction along a direction intersecting the transport direction when viewed in the thickness direction. In the coating apparatus according to any one of claims 1 to 3,
A coating apparatus, wherein a plurality of said wipers are linearly arranged along a direction intersecting said conveying direction while being spaced apart from each other when viewed in said thickness direction. In the coating apparatus according to any one of claims 1 to 3,
A coating apparatus, wherein a plurality of said wipers are arranged in a staggered manner along a direction intersecting said conveying direction when viewed in said thickness direction. In the coating apparatus according to any one of claims 1 to 8,
The coating device, wherein the wipers on both sides in the thickness direction face each other in the thickness direction with the substrate interposed therebetween. In the coating apparatus according to any one of claims 1 to 8,
The coating device, wherein the wipers on both sides in the thickness direction are alternately arranged in the conveying direction. In the coating apparatus according to any one of claims 1 to 10,
The coating device, wherein the wiper has a square tip. In the coating apparatus according to any one of claims 1 to 10,
The coating device, wherein the tip of the wiper is arc-shaped. In the coating apparatus according to any one of claims 1 to 10,
The coating device according to claim 1, wherein the tip of the wiper has a pointed shape that tapers toward the tip. In the coating device according to any one of claims 1 to 13,
further comprising a pair of blocks disposed on both sides of the base material in the thickness direction and facing each other in the thickness direction;
The base material is configured to pass through the gap between the pair of blocks,
The gap is
a base material introduction port that opens upstream in the conveying direction and into which the base material is introduced;
a base material discharge port that opens downstream in the conveying direction and discharges the base material,
The coating device, wherein the wiper is fixed to a surface of the pair of blocks facing the substrate. In the coating device according to claim 14,
The liquid reservoir is formed so that the coating liquid is accumulated in an immersion bath,
the conveying direction includes a vertical component;
The wiping mechanism and the pair of blocks are arranged in the liquid pool,
The coating device, wherein the base material discharge port is arranged at the same position as or above the liquid surface of the liquid reservoir in the vertical direction. In the coating device according to claim 15,
The coating device, wherein each of the pair of wiping mechanisms includes the wiper positioned above the liquid surface in the vertical direction. In the coating device according to claim 15 or 16,
each of the pair of wiping mechanisms includes a block wiper provided to sandwich the base material from both sides in the thickness direction at the base material outlet;
The coating apparatus, wherein the block wiper is configured such that the diameter of the base material outlet in the thickness direction is smaller than the thickness of the base material. In the coating device according to claim 14,
further comprising a coating liquid supply unit that supplies the coating liquid to the gap between the pair of blocks;
The coating apparatus according to claim 1, wherein the liquid reservoir is formed such that the coating liquid is accumulated in the gap by the coating liquid supply section. In the coating device according to claim 18,
The gap is provided with an exposure port that opens from the base material introduction port to the base material discharge port on at least one side in a width direction that intersects the conveying direction,
A coating apparatus, wherein a portion of the base material in the width direction can protrude outside the liquid reservoir from the exposure opening. Using the coating device according to any one of claims 1 to 19, when the substrate is passed through the liquid pool, the plurality of wipers in the pair of wiping mechanisms wipe both surfaces of the substrate. A coating method in which the coating liquid applied to the surface is leveled.

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