JP5413032B2 - Gravure coating equipment - Google Patents

Description

  The present invention relates to a gravure coating apparatus that forms a coating film by coating a coating liquid on a workpiece by rotating a gravure roll around its central axis.

  In recent years, a gravure coating apparatus that forms a striped coating film on an object to be coated has been proposed (see, for example, Patent Document 1). This gravure coating apparatus is used, for example, to manufacture electrode plates (positive electrode plates, negative electrode plates) of secondary batteries such as lithium ion secondary batteries.

JP 2009-28719 A

  The gravure coating apparatus disclosed in Patent Document 1 includes a container that stores a coating liquid (for example, a coating liquid in which carbon powder and a binder resin are dissolved in an organic solvent), and a rotation operation around the central axis. A gravure roll for applying a coating liquid to an object to be coated (for example, a metal foil). The gravure roll is composed of a plurality of coating parts that contact the coating object and apply the coating liquid to the coating object, and a non-coating part having a smaller diameter than the coating part. They are arranged alternately in the axial direction. In this gravure coating apparatus, a part (substantially half) of the gravure roll is positioned inside the accommodating part, and the coating liquid in the accommodating part is sequentially adhered to the outer peripheral surface of the coating part by the rotation operation of the gravure roll. Go. And the coating liquid adhering to the outer peripheral surface of a coating part is sequentially applied to a to-be-coated article by rotation operation of a gravure roll.

  Furthermore, the gravure coating apparatus of patent document 1 has provided the cover member which has an arc-shaped inner surface along the outer peripheral surface of the non-coating part of a gravure roll in the position facing the outer peripheral surface of a non-coating part. . A part of this cover member (a part excluding both end portions in the circumferential direction) is disposed in the accommodating part (accordingly, in the coating liquid). This cover member prevents the coating liquid from adhering to the non-coated portion of the gravure roll. In addition, the cover member is fixed to the coating liquid supply machine which has an accommodating part, and the position with respect to an accommodating part is being fixed.

  However, a small amount of coating liquid may enter between the inner surface of the cover member and the outer peripheral surface of the non-coated portion of the gravure roll. The applied coating liquid adheres to the inner surface of the cover member and receives a frictional force by the rotating gravure roll. Due to this friction, the solvent (organic solvent) is detached from the coating liquid adhering to the inner surface of the cover member, and solidifies into a lump. When this is repeated, a lump with the coating liquid solidified accumulates on the inner surface of the cover member, and eventually peels off from the inner surface of the cover member due to the force received from the rotating gravure roll, and enters the coating liquid in the housing portion. It was included (dispersed). For this reason, there is a risk that this lump adheres to the gravure roll and a problem (coating failure) occurs in which the mass is applied to an object to be coated (such as an aluminum foil). In particular, when a coating solution having a high viscosity (for example, 800 mPa · sec or more) is used, the above-described coating defects are likely to occur. This is because a coating liquid having a high viscosity is easily solidified.

  Moreover, in the gravure coating apparatus of patent document 1, the coating liquid (excess coating liquid adhering to the coating part of the gravure roll) scraped off by the doctor blade is the non-coating part side of the gravure roll. And adhered to the step side surface of the gravure roll (step side surface located at the boundary between the non-coated portion and the coated portion). Furthermore, there is a risk that the coating liquid adhering to the side surface of the step is applied to the object to be coated, resulting in a problem (coating failure) in which the width of the coating film is larger than the width dimension of the coating portion. . In particular, when a coating solution having a low viscosity (for example, 100 mPa · sec or less) is used, the above-described coating defects are likely to occur. This is because a coating liquid having a low viscosity is easy to spread.

  This invention is made | formed in view of this present condition, Comprising: It aims at providing the gravure coating apparatus which can suppress a coating defect.

  One aspect of the present invention is a gravure roll that coats the coating liquid onto a coated object by a storage unit that stores the coating liquid and a rotation operation around the central axis. A plurality of coating parts that contact the coating and apply the coating liquid to the coating object, and non-coating parts having a smaller diameter than the coating part alternately in the central axis direction of the gravure roll A gravure roll arranged in line with the outer peripheral surface of the non-coated portion, and a cover member having an arc-shaped inner surface along the outer peripheral surface of the non-coated portion, a part of the cover member A cover member disposed in the housing portion, and a part of the gravure roll is positioned inside the housing portion, and the coating liquid in the housing portion is removed by the rotation operation of the gravure roll. For a gravure coating device that has a structure that adheres sequentially to the outer peripheral surface of the coating part. There are, on the inner surface of the cover member, a gravure coating apparatus grooves are formed to extend over the other end in the direction of rotation of the gravure roll from one end of the inner surface.

  In the above-described gravure coating apparatus, the gravure roll is formed on the inner surface of the cover member (an arcuate surface located opposite to the outer peripheral surface of the non-coated portion of the gravure roll and along the outer peripheral surface of the non-coated portion). A groove extending from one end of the inner surface to the other end in the rotational direction is formed. Thereby, when the coating liquid enters between the inner surface of the cover member and the outer peripheral surface of the non-coated part of the gravure roll, the applied coating liquid is passed through the groove on the inner surface of the cover member to the outside of the cover member. Can be discharged. Specifically, the coating liquid that has entered between the inner surface of the cover member and the outer peripheral surface of the non-coated portion of the gravure roll enters the groove of the cover member, but a force is applied from the rotating gravure roll in the direction of rotation. By receiving, it flows in the rotation direction of the gravure roll along the groove of the cover member, and is discharged to the outside of the cover member.

  Therefore, in the above-mentioned gravure coating apparatus, it can suppress that the lump which the coating liquid solidified generate | occur | produced on the inner surface of a cover member. Thereby, the malfunction (coating defect) by which the lump which the coating liquid solidified is applied to a to-be-coated article can be suppressed.

In particular, the above-described gravure coating apparatus is effective when a coating liquid having a high viscosity (for example, 800 mPa · sec or more) is used. This is because a coating liquid having a high viscosity is easily solidified.
In addition, a cover member is fixed to the coating liquid supply machine etc. which have an accommodating part, and the position with respect to an accommodating part is fixed (it does not rotate with a gravure roll).

  Further, the gravure coating apparatus, wherein the gravure coating apparatus is in contact with the outer peripheral surface of the coating part, scrapes off the excessive coating liquid adhering to the coating part, and A doctor blade that adjusts the coating amount of the coating liquid that is applied to the object to be coated by the working part, and a blade side end located on the doctor blade side of the cover member is the gravure roll Gravure coating formed between the liquid level of the coating liquid stored in the storage unit and the tip of the doctor blade that contacts the outer peripheral surface of the coating unit. It is better to use a device.

When the lump which the coating liquid solidified accumulates on the inner surface of a cover member, a cover member may float to the radial direction outer side of a gravure roll.
On the other hand, in the gravure coating apparatus described above, the blade side end of the cover member is positioned between the liquid surface of the coating liquid stored in the storage unit and the tip of the doctor blade in the rotation direction of the gravure roll. Is located. In other words, the blade side end of the cover member is positioned behind the liquid surface of the coating liquid and behind the tip of the doctor blade in the rotation direction of the gravure roll.

  As a result, even when the cover member floats to the outside of the gravure roll in the radial direction, the cover member contacts the tip of the doctor blade and presses the tip of the doctor blade away from the coating portion of the gravure roll. There is no end. Therefore, since the excessive coating liquid adhering to the coating part can be scraped off appropriately by the doctor blade, an appropriate amount of the coating liquid can be applied to the object to be coated.

Also, a gravure roll that coats the coating liquid onto the coating object by a storage unit that stores the coating liquid and a rotation operation around the central axis, and is in contact with the coating object and A gravure roll in which a plurality of coating parts for applying the coating liquid to a workpiece and a non-coating part having a smaller diameter than the coating part are alternately arranged in the central axis direction of the gravure roll; A cover member positioned opposite to the outer peripheral surface of the non-coated portion and having an arc-shaped inner surface along the outer peripheral surface of the non-coated portion, wherein a part of the cover member is in the housing portion. Contacting the arranged cover member and the outer peripheral surface of the coating part, scraping off the excessive coating liquid adhering to the coating part, and coating the coated object by the coating part A doctor blade that adjusts the coating amount of the coating liquid, and a part of the gravure roll is contained in the container In the gravure coating apparatus having a configuration in which the coating liquid in the housing unit is sequentially attached to the outer peripheral surface of the coating unit by the rotation operation of the gravure roll, positioned inside, in the gravure coating device, The tip of the coating portion that contacts the outer peripheral surface of the coating portion is positioned vertically below the coating position where the coating portion and the workpiece are in contact, and the doctor blade of the cover member The gravure coating apparatus in which the blade side end located on the side is located between the tip of the doctor blade and the coating position in the rotation direction of the gravure roll is preferred.

  In the above gravure coating apparatus, the blade side end of the cover member is positioned between the tip of the doctor blade and the coating position (position where the coating part and the workpiece are in contact) with respect to the rotation direction of the gravure roll. It is located between. In other words, the blade side end of the cover member is positioned behind the tip of the doctor blade and behind the coating position in the rotation direction of the gravure roll. Furthermore, in the above-described gravure coating apparatus, the distal end portion of the doctor blade is positioned below the coating position in the vertical direction. Accordingly, the blade side end portion of the cover member is positioned above the tip end portion of the doctor blade in the vertical direction.

  Thereby, even when the coating liquid scraped off by the doctor blade (excess coating liquid adhering to the coating part of the gravure roll) flows to the non-coating part side of the gravure roll, It is possible to prevent the coating liquid from adhering to the step side surface (step side surface located at the boundary between the non-coating portion and the coating portion) of the gravure roll. The coating liquid scraped off by the doctor blade flows downward from the tip of the doctor blade in the vertical direction, whereas the blade side end of the cover member is positioned above the tip of the doctor blade in the vertical direction. Because.

Therefore, in the above-described gravure coating apparatus, it is possible to suppress a problem (coating failure) in which the width of the coating film is larger than the width dimension of the coating portion.
In particular, the above-described gravure coating apparatus is suitable when a coating solution having a low viscosity (for example, 100 mPa · sec or less) is used. This is because a coating liquid having a low viscosity is easy to spread.
Note that the cover member is fixed to a coating liquid supply machine or the like having a storage portion, and the position with respect to the storage portion is fixed (does not rotate with the gravure roll).

  Further, in the above gravure coating apparatus, a gravure coating in which a clearance between an outer surface of the cover member opposite to the inner surface and the tip of the doctor blade is 0.2 mm or less. It is better to use a device.

  When the outer surface of the cover member is brought into contact with the tip of the doctor blade, the position of the tip of the doctor blade with respect to the coating part fluctuates, and the doctor blade appropriately removes the appropriate amount of coating liquid adhering to the coating part (appropriate amount). ) There is a possibility that it cannot be scraped off. Such a malfunction can be prevented by positioning the outer surface of the cover member radially inside the outer peripheral surface of the coating portion.

  However, if the outer surface of the cover member is positioned radially inward from the outer peripheral surface of the coating portion and the clearance between the outer surface of the cover member and the tip of the doctor blade is too large, the cover member is disposed. Nevertheless, the stepped side surface of the gravure roll is greatly exposed at a position vertically below the tip of the doctor blade. For this reason, when the coating liquid scraped off by the doctor blade (excess coating liquid adhering to the coating part of the gravure roll) flows to the non-coating part side of the gravure roll, The coating liquid may not be able to be suppressed from adhering to the step side surface of the gravure roll.

  On the other hand, in the above-mentioned gravure coating apparatus, the clearance between the outer surface of the cover member and the tip of the doctor blade is 0.2 mm or less. Thereby, while preventing the outer surface of a cover member from contacting the front-end | tip part of a doctor blade, exposure of the level | step difference side surface of the gravure roll in the position of a perpendicular direction lower side than the front-end | tip part of a doctor blade can be suppressed. Accordingly, the doctor blade can appropriately (appropriately) scrape off the excessive coating liquid adhering to the coating portion, and can suppress the coating liquid from adhering to the step side surface of the gravure roll.

1 is a schematic side view of a gravure coating apparatus according to Example 1 and Reference Example 1. FIG. 1 is a schematic front view of a gravure coating apparatus according to Example 1 and Reference Example 1. FIG. It is a perspective view which shows the relationship between the gravure roll concerning Example 1, and a doctor blade. It is a figure explaining the structure (side surface side) of the upper part of the coating mechanism part concerning Example 1. FIG. It is a figure explaining the structure (front side) of the upper part of the coating mechanism part concerning Example 1. FIG. It is a perspective view of the cover member concerning Example 1. FIG. It is a figure showing a mode that after forming a coating film on the surface of a coated object, a coated object is divided into a predetermined size. It is a perspective view which shows the relationship between the gravure roll concerning the reference example 1 , and a doctor blade. It is a figure explaining the structure (side surface side) of the upper part of the coating mechanism part concerning the reference example 1. FIG. It is a figure explaining the structure (front side) of the upper part of the coating mechanism part concerning the reference example 1. FIG. It is a disassembled perspective view of the cover member concerning the reference example 1. FIG. FIG. 10 is a view showing a clearance G between the outer surface of the cover member and the distal end portion of the doctor blade, and corresponds to an enlarged view of a portion B in FIG. 9.

Example 1
Next, Example 1 of the present invention will be described with reference to the drawings.
In FIG. 1, the schematic side view of the gravure coating apparatus 10 of the present Example 1 is shown. In FIG. 2, the schematic front view of the gravure coating apparatus 10 is shown.

  The gravure coating apparatus 10 is an apparatus that applies the coating liquid 18 to the workpiece 50. The object to be coated 50 is a current collector base material for a positive electrode plate used in a lithium ion secondary battery, and is an aluminum foil having a thickness of about a dozen μm. The coating liquid 18 is a liquid containing carbon powder (acetylene black), a binder (polyvinylidene fluoride), and a solvent (N-methyl-2-pyrrolidone). The viscosity of the coating liquid 18 is 600 to 1000 mPa · sec. In the gravure coating apparatus 10 of the first embodiment, the coating liquid 18 is coated on the workpiece 50 with a thickness of about several μm, and a coating film 50a described later is formed with a constant film thickness. To do.

  The gravure coating apparatus 10 includes a support housing 12 mounted on the base 11, an arm 13 supported by the support housing 12, and a coating mechanism unit 20 disposed on the support mechanism 30. Provided (see FIG. 1 and FIG. 2). As shown in FIG. 1, the workpiece 50 is passed through a plurality of rollers, and is also passed between the gravure roll 21 provided in the coating mechanism 20 and the pressing roller 14 provided in the arm 13. As a result, the article to be coated 50 is in a state where tension is applied to the gravure roll 21 side by the pressing roller 14. The workpiece 50 is conveyed at a constant speed in the direction indicated by the arrow in FIG.

  As shown in FIG. 2, the gravure roll 21 is connected to a drive motor 35 via a coupling 36. The drive motor 35 is preferably a motor capable of controlling rotation, such as a servo motor. The gravure roll 21 obtains power from the drive motor 35 and rotates around its central axis C1, and, as will be described later, this rotational operation causes the workpiece 50 to be conveyed through a roller such as the pressing roller 14 to be conveyed. The coating liquid 18 is applied on the surface.

In FIG. 4, the figure explaining the structure (side surface side) of the upper part of the coating mechanism part 20 is shown. Moreover, the figure explaining the structure (front side) of the upper part of the coating mechanism part 20 to FIG. 5 is shown.
A part (specifically, substantially half) of the gravure roll 21 provided in the coating mechanism unit 20 is disposed inside a storage unit 25 a provided in the coating liquid supply machine 25. The coating liquid 18 is continuously supplied into the housing portion 25a of the coating liquid supply machine 25 through the flow path 25b. For this reason, the coating liquid 18 always overflows from the upper part of the storage part 25 a, and the coating liquid 18 that overflows from the upper part of the storage part 25 a is provided below the coating liquid supply machine 25. It is collected by a collection container (not shown). The collected coating liquid 18 is again supplied into the storage unit 25a by the coating liquid supply machine 25.

FIG. 3 is a perspective view showing the relationship between the gravure roll 21 and the doctor blade 22. In addition, in FIG. 3, illustration of the cover member 40 mentioned later is abbreviate | omitted.
The gravure roll 21 includes a cylindrical coating part 21a (three places) and a cylindrical non-coating part 21b (four places) smaller in diameter than the coating part 21a in the central axis direction (central axis C1). Are arranged alternately in the direction of One end 21 c of the gravure roll 21 is connected to the coupling 36 and receives power from the drive motor 35. The arrows shown in FIG. 3 indicate the rotation direction of the gravure roll 21. In addition, in order to hold | maintain the coating liquid 18, the outer peripheral surface 21aa of the coating part 21a is uneven | corrugated shape.

  Further, the outer peripheral surfaces 21aa of the three coating portions 21a are in contact with the surface of the workpiece 50 at a position where the rotating outer peripheral surface 21aa reaches the uppermost position (see FIG. 4). Here, a position where the outer peripheral surface 21aa of the coating part 21a and the workpiece 50 are in contact is defined as a coating position P. At the coating position P, the coating liquid 18 adhering to the outer peripheral surface 21aa of the coating portion 21a is applied to the surface of the workpiece 50.

  The doctor blade 22 is a single plate-like member extending in the central axis direction of the gravure roll 21 over a range including three coating portions 21a and two non-coating portions positioned therebetween (see FIG. 3). ). The doctor blade 22 is attached to the gravure coating apparatus 10 such that the tip 22b of the doctor blade 22 contacts the outer peripheral surface 21aa of the coating part 21a of the gravure roll 21. The doctor blade 22 may be attached by a simple fixing method, but in the first embodiment, the distal end portion 22b of the doctor blade 22 is attached to the outer peripheral surface 21aa of the coating portion 21a of the gravure roll 21 by a cylinder (not shown) or the like. Pressing with a certain force. Thereby, the excessive coating liquid 18 adhering to the outer peripheral surface 21aa of the coating part 21a can be scraped off appropriately by the doctor blade 22. The doctor blade 22 used in the first embodiment is a resin blade, and has a structure in which the blade is sandwiched and fixed by a metal jig.

  In the gravure coating apparatus 10 having the above-described configuration, the gravure roll 21 rotates around the central axis C1 to sequentially adhere the coating liquid 18 in the storage unit 25a to the outer peripheral surface 21aa of the coating unit 21a. I will let you. And after scraping off the excessive coating liquid 18 adhering to the outer peripheral surface 21aa of the coating part 21a with the doctor blade 22, the appropriate amount of coating liquid 18 adhering to the outer peripheral surface 21aa of the coating part 21a is removed. By the rotation operation of the gravure roll 21, coating is sequentially performed on the surface of the object to be coated 50 at the coating position P.

  The coating liquid 18 scraped off by the doctor blade 22 flows down and is collected by a collection container (not shown) provided below the coating liquid supply machine 25. The collected coating liquid 18 is again supplied into the storage unit 25a by the coating liquid supply machine 25.

  Further, in the gravure roll 21 of the first embodiment, the three coating parts 21a are arranged with a certain gap (with the non-coating part 21b interposed). For this reason, as shown in the upper side of FIG. 7, three (three) coating films 50 a can be simultaneously formed on the surface of the workpiece 50. Further, in Example 1, as shown in the lower side of FIG. 7, the object to be coated 50 on which three (three) coating films 50 a are formed is cut to obtain six current collectors. The member 51 is divided.

  Moreover, in the gravure coating apparatus 10 of the first embodiment, arc-shaped cover members 40 are provided at positions (four locations) facing the outer peripheral surface 21ba of the non-coated portion 21b (FIGS. 4 and 5). FIG. 6). The width dimension (the dimension in the left-right direction in FIG. 5) of the cover member 40 is substantially the same as the width dimension (the dimension in the left-right direction in FIG. 5) of the non-coated portion 21b. The inner surface 41 of the cover member 40 has an arc shape along the outer peripheral surface 21ba of the non-coated portion 21b (see FIGS. 4 and 6). As the material of the cover member 40, it is preferable to use a resin (for example, PTFE) having high sliding resistance and excellent chemical resistance.

  The cover member 40 was fixed to the coating liquid supply machine 25 in a state in which a part thereof (in the first embodiment, a portion excluding the portion on the blade side end portion 40c side) is disposed in the housing portion 25a. It is being fixed to the coating liquid supply machine 25 with the fixing member 43 (refer FIG. 4). Specifically, a V-shaped groove 45 extending in the width direction of the cover member 40 is formed on the outer surface 44 of the cover member 40, and the distal end portion of the fixing member 43 is inserted into the groove 45 to cover the cover member 40. 40 is fixed (see FIGS. 4 and 6). Thereby, the position with respect to the accommodating part 25a is fixed, without the cover member 40 rotating with the gravure roll 21. FIG.

  The blade-side end portion 40c of the cover member 40 is an end portion (one end portion) in the circumferential direction of the cover member 40 (the direction along the rotation direction of the gravure roll 21 (the direction indicated by the arrow in FIGS. 4 and 6)). 40b and the other end) refers to an end (the other end) disposed on the doctor blade 22 side.

By the way, the coating liquid may enter between the inner surface of the cover member and the outer peripheral surface of the non-coated portion of the gravure roll. In the conventional gravure coating apparatus (for example, the gravure coating apparatus of Patent Document 1), the entering coating liquid adheres to the inner surface of the cover member and receives a frictional force by a rotating gravure roll. Due to this friction, the solvent (organic solvent) is detached from the coating liquid adhering to the inner surface of the cover member, and solidifies into a lump. When this is repeated, a lump with the coating liquid solidified accumulates on the inner surface of the cover member, and eventually peels off from the inner surface of the cover member due to the force received from the rotating gravure roll, and enters the coating liquid in the housing portion. It was included (dispersed). For this reason, there is a risk that this lump adheres to the gravure roll and a problem (coating failure) occurs in which the mass is applied to an object to be coated (such as an aluminum foil). In particular, when a coating solution having a high viscosity (for example, 800 mPa · sec or more) is used, the above-described coating defects are likely to occur. This is because a coating liquid having a high viscosity is easily solidified.

  On the other hand, in the gravure coating apparatus 10 of the first embodiment, as shown in FIG. 6, the rotation direction of the gravure roll (the direction indicated by the arrow in FIGS. 4 and 6) on the inner surface 41 of the cover member 40, A plurality of grooves 42 having a V-shaped cross section extending from the one end portion 40b to the other end portion (blade side end portion 40c) are formed. As a result, when the coating liquid 18 enters between the inner surface 41 of the cover member 40 and the outer peripheral surface 21ba of the non-coated portion 21b of the gravure roll 21, it enters through the groove 42 of the inner surface 41 of the cover member 40. The applied coating liquid 18 can be discharged to the outside of the cover member 40.

  Specifically, the coating liquid 18 that has entered between the inner surface 41 of the cover member 40 and the outer peripheral surface 21 ba of the non-coated portion 21 b of the gravure roll 21 enters the groove 42 of the cover member 40. Thereafter, the gravure roll 21 flows in the rotation direction of the gravure roll 21 along the groove 42 of the cover member 40 by receiving a force in the rotation direction (direction indicated by an arrow in FIGS. 4 and 6) from the rotating gravure roll 21. Then, the cover member 40 is discharged from the blade side end portion 40 c to the outside of the cover member 40.

  Therefore, in the gravure coating apparatus 10 of the first embodiment, the cover member 40 is used even when the coating liquid 18 having a very high viscosity of 600 to 1000 mPa · sec (in other words, the coating liquid 18 that is easily solidified) is used. It can suppress that the lump which the coating liquid 18 solidified on the inner surface 41 of this occurs. Thereby, the malfunction (coating defect) by which the lump which the coating liquid 18 solidified is applied to the to-be-coated article 50 can be suppressed.

Moreover, when the lump which the coating liquid 18 solidified accumulates on the inner surface 41 of the cover member 40, there exists a possibility that the cover member 40 may float on the radial direction outer side of the gravure roll 21. FIG.
On the other hand, in the gravure coating apparatus 10 of the first embodiment, as shown in FIG. 4, the blade side end portion 40 c of the cover member 40 is rotated in the rotation direction of the gravure roll 21 (the direction indicated by the arrow in FIG. (Clockwise direction) is positioned between the liquid level L of the coating liquid 18 accommodated in the accommodating portion 25 a and the tip end portion 22 b of the doctor blade 22. In other words, the blade-side end portion 40c of the cover member 40 is more forward (upward in FIG. 4) than the liquid level L of the coating liquid 18 with respect to the rotation direction of the gravure roll 21, and from the tip end portion 22b of the doctor blade 22. Is also located rearward (downward in FIG. 4).

  As a result, even when the cover member 40 is lifted to the outside in the radial direction of the gravure roll 21 (when the blade side end 40c side of the cover member 40 is lifted to the doctor blade 22 side (right side in FIG. 4)) The member 40 does not come into contact with the doctor blade 22 and press the distal end portion 22 b of the doctor blade 22 away from the coating portion 21 a of the gravure roll 21. Therefore, in the unlikely event that the solidified lump of the coating liquid 18 is deposited and the cover member 40 is lifted to the outside in the radial direction of the gravure roll 21, the excessive coating adhered to the coating portion 21a by the doctor blade 22 is obtained. Since the working liquid 18 can be scraped appropriately, an appropriate amount of the coating liquid 18 can be applied to the workpiece 50.

  Moreover, in the gravure coating apparatus 10 of the present Example 1, as shown in FIG. 4, the one end part 40b of the cover member 40 is below the liquid level L of the coating liquid 18 accommodated in the accommodating part 25a. It is located. That is, the one end part 40b of the cover member 40 is arrange | positioned in the coating liquid 18 accommodated in the accommodating part 25a. If the one end 40b of the cover member 40 is positioned above the liquid level L of the coating liquid 18, the coating liquid 18 attached to the one end 40b of the cover member 40 is solidified to form a small lump. Thus, this small lump may enter between the inner surface 41 of the cover member 40 and the outer peripheral surface 21ba of the non-coated portion 21b of the gravure roll 21. This is because the coating liquid 18 used in Example 1 has a very high viscosity of 600 to 1000 mPa · sec and is thus easily solidified. Therefore, in the gravure coating apparatus 10 according to the first embodiment, the above-described problem can be prevented by disposing the one end portion 40b of the cover member 40 below the liquid level L of the coating liquid 18.

  In Example 1, since the cover member 40 has the above-described form, it is inevitable that the coating liquid 18 adheres to the non-coated portion 21b of the gravure roll 21. However, compared with the case where the cover member 40 is not provided, the adhesion amount of the coating liquid 18 to the non-coated portion 21b of the gravure roll 21 can be significantly reduced.

( Reference Example 1 )
Next, Reference Example 1 will be described with reference to the drawings.
The gravure coating apparatus 110 according to the reference example 1 is different from the gravure coating apparatus 10 of the first embodiment in the coating mechanism part (specifically, the cover member and the arrangement thereof), and the others are the same. (See FIGS. 1 and 2). Moreover, in this reference example 1 , compared with Example 1, a to-be-coated article and a coating liquid differ. Therefore, here, the description will focus on the points different from the first embodiment, and the description of the same points will be omitted or simplified.

The gravure coating apparatus 110 is an apparatus that applies the coating liquid 118 to the workpiece 150. The object to be coated 150 is an object in which a negative electrode mixture layer (not shown) containing a negative electrode active material is formed on the surface of a current collecting base material (copper foil) of a negative electrode plate used in a lithium ion secondary battery. It is a thing. The negative electrode composite material layer extends along the longitudinal direction of the workpiece 150, and is formed on the surface of the current collecting base material (copper foil) with three gaps. The coating liquid 118 is a liquid containing alumina powder, a binder (acrylic resin), and a solvent (N-methyl-2-pyrrolidone). The viscosity of the coating liquid 118 is 50 to 80 mPa · sec, which is considerably lower than that of the coating liquid 18 of Example 1. In the gravure coating apparatus 110 of the present reference example 1 , this coating liquid 118 is applied on the negative electrode mixture layer of the article 150 to be coated with a thickness of about several μm, and a coating film 150a described later is fixed. The film thickness is formed.

FIG. 8 is a perspective view showing the relationship between the gravure roll 21 and the doctor blade 22 according to the first reference example . In addition, in FIG. 8, illustration of the cover member 140 mentioned later is abbreviate | omitted.
FIG. 9 is a view for explaining the upper configuration (side surface side) of the coating mechanism section 120 according to the first reference example . FIG. 10 is a view for explaining the configuration (front side) of the upper part of the coating mechanism unit 120 according to the first reference example .

Also in this reference example 1 , the front-end | tip part 22b of the doctor blade 22 is made to contact the outer peripheral surface 21aa of the coating part 21a of the gravure roll 21 similarly to Example 1 (refer FIG. 8). Thereby, the excessive coating liquid 118 adhering to the outer peripheral surface 21aa of the coating part 21a can be scraped off appropriately by the doctor blade 22.
In addition, as shown in FIG. 8, the side surface of the level | step difference located in the boundary of the non-coating part 21b and the coating part 21a among the gravure rolls 21 is made into the level | step difference side surface 21ab. Further, the coating portion 21 a of the gravure roll 21 is disposed at a position facing the negative electrode mixture layer (not shown) of the article 150 to be coated at the coating position P.

Moreover, also in this reference example 1 , the arc-shaped cover member is provided in the position (4 places) facing the outer peripheral surface 21ba of the non-coating part 21b similarly to Example 1 (FIG. 9, FIG. 10). FIG. 11). However, in the first reference example , a cover member 140 different from the cover member 40 of the first embodiment is provided. The width dimension (dimension in the left-right direction in FIG. 10) of the cover member 140 is substantially the same as the width dimension (dimension in the left-right direction in FIG. 10) of the non-coated portion 21b. The inner surface 141 of the cover member 140 has an arc shape along the outer peripheral surface 21ba of the non-coated portion 21b (see FIGS. 9 and 11).

As shown in FIG. 11, the cover member 140 according to the first reference example includes a first cover member 146 and a second cover member 147. The first cover member 146 has an arc shape and includes a thick portion 146b having a large thickness and a thin portion 146c having a small thickness. The thickness (diameter dimension) of the thick part 146b is substantially the same as the dimension between the bottom surface of the accommodating part 25a and the non-coated part 21b. Further, the thickness of the thin portion 146c is a dimensional difference between the radius of the coated portion 21a and the radius of the non-coated portion 21b (between the outer peripheral surface 21aa of the coated portion 21a and the outer peripheral surface 21ba of the non-coated portion 21b). The dimension is slightly smaller than the radial distance. The second cover member 147 has an arc shape and has a thickness equivalent to the thick portion 146b of the first cover member 146. The cover member 140 is configured by bringing the end surface 146e of the first cover member 146 into contact with the end surface 147c of the second cover member 147.

  The cover member 140 is fixed to the coating liquid supply machine 25 in a state where a part thereof (in the first embodiment, a portion excluding the thin portion 146c of the first cover member 146) is disposed in the housing portion 25a. The fixing member 43 is fixed to the coating liquid supply machine 25 (see FIG. 9). Specifically, the cover member 140 is fixed such that the stepped surface 145 located at the boundary between the thick portion 146 b and the thin portion 146 c of the first cover member 146 is pushed by the tip end portion of the fixing member 43. (See FIGS. 9 and 11). Thereby, the position with respect to the accommodating part 25a is fixed, without the cover member 140 rotating with the gravure roll 21. FIG.

In the gravure coating apparatus 110 of the present reference example 1 , as shown in FIG. 9, one end portion 140b of the cover member 140 is disposed at a position equal to the liquid level L of the coating liquid 118 stored in the storage portion 25a. ing. Further, the blade side end portion 140c of the cover member 140 is arranged so that the tip end portion 22b of the doctor blade 22 and the coating position P (the outer peripheral surface of the coating portion 21a) with respect to the rotation direction of the gravure roll 21 (the direction indicated by the arrow in FIG. 9). 21aa and the position to be coated 150). The blade-side end portion 140c of the cover member 140 is an end portion (the other end portion) located on the doctor blade 22 side among the end portions (one end portion 140b and the other end portion) in the circumferential direction of the cover member 140. Say.
In the first reference example , since the cover member 140 is configured as described above, it is possible to prevent the coating liquid 118 from adhering to the non-coated portion 21b of the gravure roll 21.

By the way, as shown by an arrow in FIG. 10, the coating liquid 118 (excess coating liquid 118 adhering to the coating part 21 a of the gravure roll 21) scraped by the doctor blade 22 is applied to the gravure roll 21. In addition to flowing down along the outer peripheral surface 21aa of the coating part 21a, the gravure roll 21 may flow toward the non-coating part 21b side (spread in the left-right direction). This is because the viscosity of the coating liquid 118 used in the present Reference Example 1 is as low as 50 to 80 mPa · sec, so that it easily spreads.

  For this reason, in a conventional gravure coating apparatus (for example, the gravure coating apparatus of Patent Document 1), when a coating liquid having the same degree of viscosity as the coating liquid 118 is used, the gravure roll non-coating part side The coating liquid that flowed to the surface sometimes adhered to the stepped side surface of the gravure roll (stepped side surface located at the boundary between the non-coated portion and the coated portion). Furthermore, there is a risk that the coating liquid adhering to the side surface of the step is applied to the object to be coated, resulting in a problem (coating failure) in which the width of the coating film is larger than the width dimension of the coating portion. .

On the other hand, in the gravure coating apparatus 110 according to the first reference example , as described above, the blade side end portion 140c of the cover member 140 is rotated in the rotation direction of the gravure roll 21 (the direction indicated by the arrow in FIG. ) Is positioned between the distal end portion 22b of the doctor blade 22 and the coating position P (the position where the outer peripheral surface 21aa of the coating portion 21a and the workpiece 150 are in contact). In other words, the blade-side end portion 140c of the cover member 140 is ahead of the tip end portion 22b of the doctor blade 22 in the rotational direction of the gravure roll 21 (upper left in FIG. 9) and behind the coating position P (see FIG. 9 in the lower right). Furthermore, the distal end portion 22b of the doctor blade 22 is located below the coating position P in the vertical direction. Accordingly, the blade-side end portion 140 c of the cover member 140 is positioned above the tip end portion 22 b of the doctor blade 22 in the vertical direction.

Thereby, as shown by an arrow in FIG. 10, the coating liquid 118 (excess coating liquid 118 adhered to the coating part 21 a of the gravure roll 21) scraped by the doctor blade 22 is removed from the gravure roll 21. Even when it flows to the non-coating portion 21b side, the coating liquid 118 adheres to the stepped side surface 21ab of the gravure roll 21 by the cover member 140 (specifically, the thin portion 146c of the first cover member 146). Can be suppressed. The coating liquid 118 scraped off by the doctor blade 22 flows downward in the vertical direction from the distal end portion 22b of the doctor blade 22, whereas the blade side end portion 140c of the cover member 140 is replaced with the distal end portion 22b of the doctor blade 22. This is because it is positioned above the vertical direction.
Therefore, in the gravure coating apparatus 110 of the present reference example 1 , it is possible to suppress a problem (coating failure) in which the width of the coating film 150a is larger than the width dimension of the coating portion 21a.

  By the way, when the outer surface 146d of the cover member 140 (specifically, the thin portion 146c of the first cover member 146) is brought into contact with the distal end portion 22d of the doctor blade 22, the doctor blade 22 causes an excessive amount attached to the coating portion 21a. There is a possibility that the coating liquid 118 cannot be scraped appropriately (appropriate amount). Such a problem can be prevented by positioning the outer surface 146d of the cover member 140 radially inward from the outer peripheral surface 21aa of the coating portion 21a.

  However, the outer surface 146d of the cover member 140 is positioned radially inward of the outer peripheral surface 21aa of the coating portion 21a, and the clearance between the outer surface 146d of the cover member 140 and the distal end portion 22b of the doctor blade 22 is excessively increased. Even though the cover member 140 is disposed, the stepped side surface 21ab of the gravure roll 21 is greatly exposed at a position lower than the distal end portion 22b of the doctor blade 22 in the vertical direction. For this reason, the coating liquid 118 (excess coating liquid 118 adhering to the coating part 21a of the gravure roll 21) scraped off by the doctor blade 22 flows to the non-coating part 21b side of the gravure roll 21. In such a case, the cover member 140 may not be able to prevent the coating liquid 118 from adhering to the stepped side surface 21ab of the gravure roll 21.

In contrast, in the gravure coating apparatus 110 according to the first reference example , as shown in an enlarged view in FIG. 12, the clearance G (shortest distance) between the outer surface 146d of the cover member 140 and the distal end portion 22b of the doctor blade 22 is shown. Is 0.2 mm or less (for example, 0.1 mm). This prevents the outer surface 146d of the cover member 140 from coming into contact with the distal end portion 22b of the doctor blade 22, and the stepped side surface 21ab of the gravure roll 21 at a position vertically below the distal end portion 22b of the doctor blade 22. Exposure can be suppressed.
Therefore, the doctor blade 22 can appropriately (appropriately) scrape the excess coating liquid 118 adhering to the coating part 21 a, and the coating liquid 118 scraped by the doctor blade 22 can be stepped on the gravure roll 21. Adhesion to the side surface 21ab can be suppressed.

In the gravure coating apparatus 110 according to the first reference example , as in the gravure coating apparatus 10 according to the first embodiment, as shown on the upper side of FIG. ) Coating film 150a can be formed simultaneously. After that, as shown in the lower side of FIG. 7, the object 150 on which the three (three) coating films 150 a are formed is cut and divided into six negative plates 151.

While the present invention has been described with reference to the first embodiment, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof. .

DESCRIPTION OF SYMBOLS 10,110 Gravure coating apparatus 18,118 Coating liquid 21 Gravure roll 21a Coating part 21aa Coating outer peripheral surface 21ab Step side surface 21b Non-coating part 21ba Non-coating part outer peripheral surface 22 Doctor blade 22b Doctor blade Front end portion 25 Coating liquid supply machine 25a Housing portion 40, 140 Cover member 40c, 140c Cover member blade side end portion 41, 141 Cover member inner surface 42 Cover member inner surface groove 50, 150 Workpiece 50a, 150a Coating film 146d Outer surface L of cover member Liquid surface P of coating liquid Coating position

Claims (2)

A storage section for storing the coating liquid;
A gravure roll for applying the coating liquid to a coated object by rotating around a central axis, and applying the coating liquid to the coated object in contact with the coated object A plurality of coated parts, and a non-coated part having a smaller diameter than the coated part, a gravure roll alternately arranged in the central axis direction of the gravure roll,
A cover member positioned opposite to the outer peripheral surface of the non-coated portion and having an arc-shaped inner surface along the outer peripheral surface of the non-coated portion, wherein a part of the cover member is disposed in the housing portion A cover member,
A configuration in which a part of the gravure roll is positioned inside the housing portion, and the coating liquid in the housing portion is sequentially attached to the outer peripheral surface of the coating portion by the rotating operation of the gravure roll. In the gravure coating device that has,
A gravure coating apparatus in which a groove extending from one end of the inner surface to the other end in the rotation direction of the gravure roll is formed on the inner surface of the cover member. The gravure coating apparatus according to claim 1,
The gravure coating apparatus is
Application of the coating liquid in contact with the outer peripheral surface of the coating part, scraping off the excessive coating liquid adhering to the coating part, and coating the article to be coated by the coating part A doctor blade that adjusts the amount,
The blade-side end portion of the cover member located on the doctor blade side in the rotation direction of the gravure roll, the liquid surface of the coating liquid stored in the storage portion, and the coating blade of the doctor blade. A gravure coating device located between the outer peripheral surface of the work part and the tip part in contact with it.

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