JP2019188332A - Die coating device - Google Patents

Abstract

To provide a die coating device improved in the accuracy of a coating width.SOLUTION: A die coating device for coating an object with a coating material has: a first die 7; a second die 10 for forming a slit-shaped discharge port for discharging the coating material between the first die 7 and itself by being mated with the first die 7; and a first shim 8 and a second shim 9 overlappingly sandwiched between the first die 7 and the second die 10, and regulating a flow passage of the discharge port. The first shim 8 located at an upstream side on the object in a moving direction out of the first shim 8 and the second shim 9 has a shape not constituting a flow passage in a center portion in a longitudinal direction of the discharge port, and constituting trimmed flow passages 18 at both end portions, and the second shim 9 has a shape not constituting a flow passage in a region in which the coating material is supplied by the trimmed flow passage 18, and constituting a main flow passage 24 in a center portion being a region in which the coating material is not supplied by the trimmed flow passages 18.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a die coating apparatus that performs coating by supplying a coating material to a moving object. More specifically, the present invention relates to a die coating apparatus configured by combining two dies.

  Conventionally, a coating film is formed by die coating in various fields. For example, Patent Document 1 discloses a coating apparatus that performs multilayer simultaneous coating using a die coater. In the apparatus of FIG. 1 of the same document, a plurality of pockets (20 to 22) and slots (23 to 25) are provided in one slot die (13). As a result, the object (12) is coated in three layers with a single coating.

JP 2003-260400 A

  However, the conventional techniques described above have the following problems. There is a difficulty in the accuracy of the coating width. This document refers to the adjustment of the coating width by the “width regulating plate” ([0023] of the same document). However, since the coating material (“application liquids 14, 15, 16” in the same document) is a fluid, it sometimes spreads in the width direction on the object after exiting the slot die. Since this spreading method is difficult to be constant, the coating width may not be as intended.

  The present invention has been made to solve the above-described problems of the prior art. That is, the object is to provide a die coating apparatus with improved coating width accuracy.

  A die coating apparatus according to an aspect of the present invention is an apparatus that coats an object with a coating material, and a coating material between the first die and the first die that is combined with the first die. A second die that forms a slit-like discharge port for discharging water, and a first shim and a second shim that are sandwiched between the first die and the second die and restrict the flow path of the discharge port. However, the first shim of the first shim and the second shim, which is upstream in the moving direction of the object, does not constitute a flow path in the central portion in the longitudinal direction of the discharge port, and is edged at both end portions. The second shim has a shape that constitutes the flow path, and the second shim does not constitute a flow path in the area where the coating material is supplied by the edge flow path, and the supply material is supplied by the edge flow path. It is of a shape that constitutes the main flow path in the central portion, which is a non-existing region.

  In the die coating apparatus according to the above aspect, first, coating is performed on the object in the edge flow channel at both ends in the width direction (longitudinal direction of the discharge port), and then coating is performed in the main flow channel in the central portion. . Thereby, both ends of the coating layer are first defined, and then the region between them is filled with the coating material. This improves the accuracy of the coating width. In addition, the coating of the border portion and the coating of the center portion can be performed by passing the object once through the die coating apparatus. The slit-shaped discharge port formed between the first die and the second die is a shape formed by sandwiching the first shim and the second shim between the first die and the second die. It shall be said.

  According to this configuration, a die coating apparatus with improved coating width accuracy is provided.

It is a perspective view of the die coating apparatus which concerns on embodiment, and the electrode plate coated by it. It is a disassembled perspective view which shows the structure of the die coating apparatus which concerns on embodiment. It is a top view which shows the state which accumulated the 1st die | dye and the 1st shim. It is a top view which shows the state which accumulated the 1st die | dye, the 1st shim, and the 2nd shim. It is a front view which shows the die coating apparatus which concerns on embodiment from the discharge port side. It is sectional drawing which shows the condition which laminates | stacks and presses a positive / negative electrode plate. (Comparative example) It is sectional drawing of the condition corresponded in FIG. 6 in case the precision of coating width is low.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the present invention is embodied as a die coating apparatus 1 that performs the coating method shown in FIG. FIG. 1 shows a die coating apparatus 1 and an electrode plate 2 that is a coated object that has been coated. An object to be coated in this embodiment is a current collector foil 3 that is a core material of the electrode plate 2. In the die coating apparatus 1, the electrode mixture layer 4 is coated on the surface of the current collector foil 3. Thereby, the electrode plate 2 is obtained.

  The electrode mixture layer 4 formed by the die coating apparatus 1 has an edge portion 5 near both ends in the width direction and a center portion 6 between them. However, the rim portion 5 and the center portion 6 have the same composition, and there is no difference in the characteristics on the electrode reaction. The entire electrode mixture layer 4 is integrated with the charge / discharge function of the battery. The only difference between the edge portion 5 and the center portion 6 is that the timing at the time of coating by the die coating apparatus 1 is slightly different. The electrode plate 2 coated with the die coating apparatus 1 is actually used after being subjected to a drying process for removing the solvent component of the electrode mixture layer 4 after that.

  The die coating apparatus 1 will be described. The die coating apparatus 1 is configured by overlapping four members shown in FIG. The four members are a first die 7, a first shim 8, a second shim 9, and a second die 10 from the bottom in FIG. A concave manifold 11 is formed on the first die 7. Also in the second die 10, a concave portion similar to the manifold 11 is formed on the back side surface not visible in FIG. 2. When the first die 7 and the second die 10 are combined in the direction shown in FIG. 2 as they are, a hollow space by the manifold 11 is formed. This hollow space is a space containing a coating material to be used for coating.

  In the actual die coating apparatus 1, the first shim 8 and the second shim 9 are sandwiched between the first die 7 and the second die 10. The order of superposition is as shown in FIG. The first shim 8 and the second shim 9 are for forming a flow path for discharging the coating material in the manifold 11 between the first die 7 and the second die 10 for coating. . The first shim 8 is formed with a penetrating portion 17 that penetrates between the front and back surfaces, and two bordered flow passage portions 18 that open forward (downward in the left direction in FIG. 2) therefrom. A region between the two rimmed flow path portions 18 serves as a central blocking portion 19 that does not constitute a flow path.

  The second shim 9 is formed with a penetrating portion 21 that penetrates between the front and back surfaces, and a main channel portion 24 that opens forward from there. The main flow path portion 24 is formed at a position overlapping the central blocking portion 19 in the first shim 8. Positions on both sides of the main flow path portion 24 in the second shim 9 are side blocking portions 26 that do not constitute a flow path. The edge flow path portion 18 of the first shim 8 is formed at a position overlapping the side blocking portion 26 in the second shim 9.

  FIG. 3 shows a state in which the first die 7 and the first shim 8 among the four members are overlapped. In FIG. 3, the first die 7 is only visible at the location of the penetrating portion 17 and the location of the edge channel portion 18 in the first shim 8. Of these, the portion of the manifold 11 of the first die 7 is visible at the bordered flow path portion 18.

  FIG. 4 shows a state in which the second shim 9 is further superimposed on the state of FIG. In FIG. 4, the first die 7 (portion of the manifold 11) is visible only at the location of the penetrating portion 21 in the second shim 9. The portion of the bordering channel portion 18 described above is covered with the side blocking portion 26 in the second shim 9 and is not visible. Further, at the location of the main flow path portion 24 in the second shim 9, the central blocking portion 19 in the first shim 8 is visible, but the first die 7 is not visible.

  When the second die 10 is further overlapped with the state of FIG. 4, the die coating apparatus 1 shown in FIG. 1 is obtained. The front surface in FIG. 1 in the die coating apparatus 1 is the surface of the second die 10 (the surface facing upward in FIG. 2). In FIGS. 3 and 4, the topmost one in each state (the first shim 8 in FIG. 3 and the second shim 9 in FIG. 4) is hatched.

  The figure which looked at the die coating apparatus 1 from the discharge outlet side is shown in FIG. FIG. 5 shows the die coating apparatus 1 as viewed from the electrode plate 2 side in FIG. The flow direction (upper right to lower left in FIG. 1) of the current collector foil 3 (electrode plate 2) to be coated by the die coating apparatus 1 is upward from the bottom in FIG. In FIG. 5, hatching is given in the range where the above four members exist.

  As shown in FIG. 5, in the die coating apparatus 1, a slit-like discharge port is formed between the first die 7 and the second die 10 by the first shim 8 and the second shim 9. That is, the discharge port of the die coating apparatus 1 is formed between the first die 7 and the second die 10 by the edge flow path portion 18 in the first shim 8 and the main flow path portion 24 in the second shim 9. This is a gap (a portion without hatching in FIG. 5).

  The edge channel 18 is a coating material channel for forming the edge 5 of the electrode mixture layer 4 shown in FIG. The main channel portion 24 is a coating material channel for forming the central portion 6 of the electrode mixture layer 4. Therefore, with respect to the entire coating width in FIG. 5, the edge channel 18 is located at both ends, and the main channel 24 is located between them, that is, at the center. There are almost no overlapping portions or gaps between the rimmed channel portion 18 and the main channel portion 24. Further, when viewed in comparison with the flow direction of the current collector foil 3, the edge flow path portion 18 is positioned slightly upstream from the main flow path portion 24. Further, inside the die coating apparatus 1, the manifolds 11 of both the first die 7 and the second die 10 are connected by the through portions 17 and 21.

  When coating is performed as shown in FIG. 1 with the die coating apparatus 1 configured as described above, the border portion 5 in the vicinity of both ends in the width direction is first coated, and then the central portion 6 is coated. It will be. When the border portion 5 is first coated, the coating material supplied from the border flow path portion 18 onto the current collector foil 3 hardly spreads on the current collector foil 3. This is because the edge channel 18 has a small dimension in the width direction (left and right direction in FIG. 5), and the supply amount of the coating material is limited. Even when the central portion 6 is applied immediately after that, the outer end of the rim portion 5 is not pushed outward. This is because the supply amount of the coating material from the main flow path portion 24 is somewhat large, but the coating material is supplied only to the region between the edge portions 5 on both sides. For this reason, the stability of the full width of the electrode mixture layer 4 shown in FIG. 1 is very high. Moreover, the coating of the rim portion 5 and the coating of the central portion 6 can be performed by a single coating by the die coating apparatus 1.

  In this way, the application of the electrode plate by the die coating apparatus 1 has the following advantages. FIG. 6 shows a case where the electrode mixture layer 4 (negative electrode), the separator layer 27, and the electrode mixture layer 28 (positive electrode) are sequentially applied to the current collector foil 3 by the die coating apparatus 1, It shows the situation of pressing in the thickness direction to increase the density after coating. Here, since the accuracy of the width of each coating layer is very high, as shown in FIG. 6, it can be set so that there is almost no uncoated portion of the current collector foil 3. This means that a short circuit between the electrode mixture layer 28 (positive electrode) and the current collector foil 3 hardly occurs. Moreover, the thickness of the press object shown in FIG. 6 is almost the same at any location. Therefore, since the pressing pressure is applied uniformly to the entire object to be pressed, cracks during pressing of the electrode mixture layers 4, 28, etc. are unlikely to occur.

  If the accuracy of the width of each coating layer is poor, the position of the end of the coating layer may be displaced. In that case, a short circuit may occur due to protrusion in the width direction between the positive and negative electrodes. In order to prevent this, it is conceivable to set the coating width to be smaller in the upper layer, but in that case, cracks may occur in the electrode mixture layers 4, 28, etc. during pressing. This is because if the thickness of the object to be pressed varies depending on the location due to the presence of the non-coated part, the method of applying the pressing pressure becomes non-uniform. By using the die coating apparatus 1 of the present embodiment, those adverse effects can be reduced.

  As described in detail above, according to the die coating apparatus 1 according to the present embodiment, the coating of the border portion 5 and the coating of the central portion 6 in the entire width of the electrode mixture layer 4 are sequentially performed. Can be done with a pass. Thereby, the die coating apparatus 1 with high accuracy in the width direction is realized. Also, the number of coatings can be small.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the object to be coated is not limited to the battery electrode plate, and may be anything. Even when battery electrode plates are targeted, there are no particular limitations on the type of battery or the polarity of the electrode plates.

DESCRIPTION OF SYMBOLS 1 Die coating apparatus 7 1st die | dye 1st shim 9 2nd shim 10 2nd die | dye 18 Edge flow path part 24 Main flow path part

Claims (1)

A die coating device for applying a coating material to an object,
The first die,
A second die which is combined with the first die and forms a slit-like discharge port for discharging the coating material between the first die;
A first shim and a second shim that are sandwiched between the first die and the second die and restrict the flow path of the discharge port;
Of the first shim and the second shim, the first shim that is upstream in the moving direction of the object does not form a flow path in the central portion in the longitudinal direction of the discharge port, Is the shape that forms the edging channel,
The second shim does not constitute a flow path in a region where the coating material is supplied by the edging flow channel, and is mainly used in a central portion which is a region where the coating material is not supplied by the edging flow channel. A die coating apparatus having a shape constituting a road.

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