Multi-slot die coater

Abstract

The present invention provides a multi-slit die coater that can easily adjust the coating gap and achieve width-direction deviation control of the coating gap. According to the configuration of the present disclosure, a step is formed between the rear surfaces of the die blocks by a fixed block having a step portion. The fixed block has a step portion of a preset height, any one of the die blocks is coupled to the step portion, and the other die block is coupled to a portion other than the step portion, so that a step is naturally formed between the rear surfaces of the die blocks by coupling the die blocks to the fixed block. Therefore, the distance between the front end of the die block and the substrate, that is, the coating gap is at a desired level at all times, and because the fixed block is fixed between the die blocks, once set, the coating gap remains unchanged during the process, thereby suppressing the width-direction coating gap deviation.

Description

Technical Field

[0001] The present disclosure relates to a multi-slot die coater capable of simultaneously forming two or more layers by wetting, and more particularly, to a multi-slot die coater having a width direction deviation control device for a coating gap. This application claims priority to Korean Patent Application Nos. 10-2020-0104884 and 10-2020-0104885 filed in Korea on August 20, 2020, the disclosure of which is hereby incorporated by reference. Background Art

[0002] With the continuous development of technology and the growing demand for mobile devices, the demand for secondary batteries as energy sources is rapidly increasing, and such secondary batteries essentially include an electrode assembly as an electric energy generating element. The electrode assembly includes a positive electrode, a separator and a negative electrode stacked at least once, and the positive electrode and the negative electrode are manufactured by coating and drying a positive electrode active material slurry and a negative electrode active material slurry on a current collector made of aluminum foil and a current collector made of copper foil, respectively. In order to make the charge and discharge characteristics of the secondary battery uniform, it is necessary to uniformly coat the positive electrode active material slurry and the negative electrode active material slurry on the current collector, and a slit die coater is used.

[0003] Figure 1 An example of a coating method using a conventional slot die coater is shown.

[0004] Reference Figure 1 , the electrode manufacturing method using the slot die coater includes applying the active material slurry flowing out of the slot die coater 30 to the current collector 20 conveyed by the coating roller 10. The active material slurry flowing out of the slot die coater 30 is applied to the entire surface of the current collector 20 to form an electrode active material layer. The slot die coater 30 includes two mold blocks 31 and 32 and a slit 35 between the two mold blocks 31 and 32, and can distribute one type of active material slurry through an outlet 37 connected to the slit 35 to form an electrode active material layer. Compared with rod coating or blade coating (commacoating), the slot die coater realizes high-speed coating, and due to this advantage, it is widely used from the perspective of high productivity.

[0005] In order to manufacture a secondary battery with high energy density, the thickness of the active material layer of about 130 μm is gradually increased to 300 μm. When a thick active material layer is formed with a conventional slot die coater 30, the final electrode is not uniformly manufactured because the migration of the binder and the conductive material in the active material slurry deepens during drying. To solve this problem, when the active material layer is coated with a small thickness, dried, and the process is repeated, it takes a long time to perform two coatings. In order to improve electrode performance and productivity, a double slot die coater capable of applying two active material slurries at the same time is required.

[0006] Figure 2 is a cross-sectional view of a conventional double slot die coater along the moving direction (machine direction (MD)) of the current collector 20 .

[0007] Reference Figure 2 , the double slot die coater 40 is assembled from three mold blocks 41, 42, and 43. Slits are formed between adjacent mold blocks 41, 42, and 43, and thus the double slot die coater 40 includes two slits 45 and 46. Two types of active material slurries are simultaneously distributed on the current collector 20 through outlets 47 and 48 that are respectively communicated with the slits 45 and 46. By continuously applying additional active material slurries on the active material layer formed by the previously applied active material slurry, two active material layers can be formed simultaneously.

[0008] The process using the double slot die coater 40 has difficulty in forming each active material layer to a desired thickness due to the use of active material slurries distributed simultaneously from different outlets 47 and 48 .

[0009] The distance G from the outlet 47, 48 to the surface of the current collector 20 is the coating gap and is a very important variable for determining the coating quality of the active material layer. Generally, the thickness of each active material layer is affected by the amount of active material slurry distributed through the outlets 47, 48, the type of active material slurry and the coating gap. In addition, when the coating gap is uniform in the width direction (TD direction) of the current collector, a stable coating is achieved, and the coating gap deviation in the width direction has a great influence on the coating width and the uncoated boundary shape. The thickness of the active material layer is a very small value of tens to hundreds of μm, and even a change of a few μm can greatly affect the coating quality, so it is necessary to manage the thickness of the active material layer very strictly, and in order to stably perform uniform coating in the width direction of the current collector, it is necessary to manage very strictly to achieve uniform dimensional accuracy in the width direction. However, when the double slit die coater 40 increases the width to use a wide current collector in order to increase the production volume, it is more difficult to achieve uniform coating in the width direction, so it is more necessary to achieve a precisely controlled coating gap.

[0010] In addition, the appropriate range of the coating gap is set according to the type of active material slurry. In the production process, multiple types of active material slurries are used instead of one type of active material slurry to produce various types of products. It is difficult to provide a double slit die coater for each active material slurry to accommodate various types of active material slurries. Accordingly, one type of active material slurry is coated using a double slit die coater, and after the coating is completed, different types of active material slurries are coated using a double slit die coater, and the previously set coating gap needs to be adjusted. In addition, because it is difficult to always prepare evenly even the same type of active material slurry, there is a dispersion in the performance depending on the time of preparing the slurry, so it is necessary to deal with the dispersion, and as the coating is performed faster, the coating quality deviation increases due to the dispersion of the active material slurry performance, so the coating gap control is more important.

[0011] In order to form a desired coating gap, the conventional technology requires repeating the task of testing the coating process several times, disassembling and reassembling each mold block, adjusting the coating gap and checking. However, the coating gap is a variable that is adjusted so sensitively that the coating gap varies according to the fastening strength of the bolts used to assemble the mold blocks 41, 42 and 43, and may vary according to the force used to pump the active material slurry. Because the slot die coater has a slot on the coupling surface of the mold block, three mold blocks 41, 42 and 43 are basically required to include two slots 45 and 46, such as the double slot die coater 40. In order to configure an apparatus having a similar footprint and volume to the conventional slot die coater 30 including one slot, the thickness of each mold block 41, 42 and 43 must be reduced, and therefore, inevitably, it is easily deformed and distorted in structure. When deformation or distortion occurs, the adjusted coating gap changes, causing electrode process defects. Furthermore, this problem is exacerbated in multi-slot die coaters having an increased number of die blocks due to the inclusion of two or more slots. Summary of the invention

[0012] Technical issues

[0013] The present disclosure is intended to solve the above-mentioned problems, and thus the present disclosure is directed to providing a multi-slot die coater that can easily adjust a coating gap and control a width direction deviation of the coating gap.

[0014] However, problems to be solved by the present disclosure are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art through the description of the present invention described below.

[0015] Technical Solution

[0016] To solve the above problems, a multi-slot die coater according to the configuration of the present disclosure is a multi-slot die coater including a lower slit and an upper slit, and the multi-slot die coater includes: a lower mold block; an intermediate mold block, located on the lower mold block, so that the lower slit is formed between the intermediate mold block and the lower mold block; and an upper mold block, located on the intermediate mold block, so that the upper slit is formed between the upper mold block and the intermediate mold block, wherein the lower mold block, the intermediate mold block and the upper mold block respectively include a lower mold lip, an intermediate mold lip and an upper mold lip forming their respective front ends, and the multi-slot die coater further includes a fixing block , the fixing block is located on the rear surface of the lower mold block, the middle mold block and the upper mold block on the side opposite to the front end, the fixing block is fixed to the rear surfaces of at least two of the lower mold block, the middle mold block and the upper mold block with bolts to couple the two mold blocks, and the fixing block includes a step portion, the step portion protrudes toward the front end relative to a reference plane that is in close contact with the rear surface of any one of the two mold blocks, and the rear surface of the other of the two mold blocks is in close contact with the step portion to form a step between the rear surfaces of the two mold blocks coupled to the fixing block.

[0017] According to an aspect of the present disclosure, the fixing block couples the upper mold block to the middle mold block, and the step portion is in close contact with a rear surface of the upper mold block or a rear surface of the middle mold block.

[0018] In this case, the fixing block may extend to the rear surface of the lower mold block, so the fixing block may also be coupled to the rear surface of the lower mold block. In another example, the multi-slot die coater may further include a flat plate-shaped fixing portion fixed to the rear surface of the middle mold block and the rear surface of the lower mold block with bolts.

[0019] According to another aspect of the present disclosure, the fixing block couples the middle mold block to the lower mold block, and the step portion is in close contact with a rear surface of the middle mold block or a rear surface of the lower mold block.

[0020] In this case, the fixing block may extend to the rear surface of the upper mold block, and thus the fixing block may also be coupled to the rear surface of the upper mold block. In another example, the multi-slot die coater may further include a flat plate-shaped fixing portion fixed to the rear surfaces of the upper mold block and the middle mold block with bolts.

[0021] In a specific example, the fixing block couples the upper mold block to the middle mold block, the step portion is in close contact with a rear surface of the upper mold block, and the upper mold block may be shorter in length than the middle mold block and the lower mold block.

[0022] The lower mold lip, the middle mold lip and the upper mold lip may be arranged on the same straight line.

[0023] In another example, a lower outlet connected to the lower slit is formed between the lower mold lip and the middle mold lip, an upper outlet connected to the upper slit is formed between the middle mold lip and the upper mold lip, and a multi-slit die coater extrude and coats the active material slurry on the surface of a continuously moving substrate through at least one of the lower slit or the upper slit, and a step is formed between the lower outlet and the upper outlet.

[0024] A multi-slit die coater according to another configuration is a double-slit die coater, comprising: a lower die including a lower slit, and an upper die located on the lower die, the upper die including an upper slit, wherein a first plane formed on the lower die and a second plane formed below the upper die contact each other to form a sliding surface, and the upper die and the lower die are installed so that any one of the upper die and the lower die slides along the sliding surface to make relative movement in a horizontal direction, the multi-slit die coater further comprising a fixing block on a rear surface on a side opposite to the front ends of the lower die and the upper die, the fixing block being fixed to the rear surfaces of the lower die and the upper die with bolts to couple the lower die to the upper die, and the fixing block comprising a step portion, the step portion protruding toward the front end relative to a reference plane in close contact with a rear surface of any one of the lower die and the upper die, and when the rear surface of the other of the lower die and the upper die is in close contact with the step portion, a step is formed between the rear surfaces of the lower die and the upper die coupled to the fixing block.

[0025] The lower mold may include a lower mold block and a first intermediate mold block located on the lower mold block, so that a lower slit is formed between the first intermediate mold block and the lower mold block, and the upper mold includes a second intermediate mold block installed on the first intermediate mold block and an upper mold block placed on the second intermediate mold block, so that an upper slit is formed between the upper mold block and the second intermediate mold block.

[0026] In this case, the fixing block may couple the first intermediate mold block to the second intermediate mold block, and the step portion may be in close contact with a rear surface of the second intermediate mold block or a rear surface of the first intermediate mold block.

[0027] The fixing block may extend to a rear surface of the lower mold block, and thus the fixing block may also be coupled to the rear surface of the lower mold block.

[0028] The fixing block may extend to a rear surface of the upper mold block, and thus the fixing block may also be coupled to the rear surface of the upper mold block.

[0029] The multi-slit die coater may further include a flat plate-shaped fixing portion bolted to the rear surface of the upper mold block and the rear surface of the second middle mold block, or a flat plate-shaped fixing portion bolted to the rear surface of the first middle mold block and the rear surface of the lower mold block.

[0030] The step portion may be in close contact with a rear surface of the second intermediate mold block, and the upper mold may be shorter in length than the lower mold.

[0031] The lower mold lip, the first middle mold lip, the second middle mold lip and the upper mold lip may respectively include a lower mold lip, a first middle mold lip, a second middle mold lip and an upper mold lip forming their respective front ends, and the lower mold lip, the first middle mold lip, the second middle mold lip and the upper mold lip may respectively be arranged on the same straight line.

[0032] The lower mold lip, the first intermediate mold lip, the second intermediate mold lip and the upper mold lip may respectively include a lower mold lip, a first intermediate mold lip, a second intermediate mold lip and an upper mold lip forming their respective front ends, a lower outlet connected to the lower slit may be formed between the lower mold lip and the first intermediate mold lip, an upper outlet connected to the upper slit may be formed between the second intermediate mold lip and the upper mold lip, and the multi-slit mold coater may extrude and coat the active material slurry onto the surface of a continuously moving substrate through at least one of the lower slit or the upper slit, and a step may be formed between the lower outlet and the upper outlet.

[0033] In the multi-slot die coater according to the present disclosure, a plurality of fixing blocks may be provided in a width direction of the multi-slot die coater.

[0034] A cross section of the fixing block spanning the step portion and the reference plane includes a first cross section portion and a second cross section portion extending perpendicular to the first cross section portion.

[0035] The fixing block is not divided into multiple parts and can be a single-piece part.

[0036] Beneficial Effects

[0037] According to the configuration of the present disclosure, a step is formed between the rear surfaces of the mold blocks by a fixed block having a step portion. The fixed block has a step portion of a preset height, and any one mold block is coupled to the step portion, and the other mold block is coupled to other portions except the step portion, so by coupling the mold block to the fixed block, a step is naturally formed between the rear surfaces of the mold blocks. Therefore, the distance between the front end of the mold block and the substrate, that is, the coating gap can always be maintained at a desired level, and because the fixed block is fixed between the mold blocks, once set, the coating gap does not change during the process and is maintained, thereby suppressing the coating gap deviation in the width direction.

[0038] According to another configuration of the present disclosure, a step is formed between the rear surfaces of the upper mold and the lower mold by a fixed block having a step portion. The fixed block has a step portion of a preset height, any one mold is coupled to the step portion, and the other mold is coupled to a portion other than the step portion, so that by coupling the mold to the fixed block, a step is naturally formed between the rear surfaces of the molds. Therefore, the distance between the front end of the mold and the substrate, that is, the coating gap can always be maintained at a desired level, and because the fixed block is fixed between the mold blocks, once set, the coating gap does not change during the process and is maintained, thereby suppressing the coating gap deviation in the width direction.

[0039] Therefore, according to the present disclosure, when adjusting the coating gap, it is not necessary to disassemble and reassemble the mold block, which is structurally fragile due to its small thickness, and a uniform coating gap can be always maintained by a simple operation of coupling the mold block to the fixed block. In addition, the fixed block can reliably achieve uniform width-direction gap control through large surface contact of a device such as a block.

[0040] According to the present disclosure, considering that the mold block is deformed by the release pressure of the active material slurry, the coating amount and the resulting coating quality can be uniformly controlled by maintaining a uniform (±2%) coating gap. Therefore, by using a multi-slit die coater with a uniform coating gap, a coated product with uniform quality, particularly an electrode for a secondary battery, can be obtained.

[0041] As described above, according to the present disclosure, even if the pressure of the active material slurry flowing out increases, the coating gap can be maintained once adjusted despite the use of a thin mold block. The workability and reproducibility of coating can be ensured.

[0042] Using the multi-slot die coater, a coating layer (particularly an active material layer) can be uniformly formed to a desired thickness, and preferably, two or more types of electrode active material slurries can be simultaneously coated, thereby improving performance and productivity.

[0043] According to the present disclosure, a plurality of fixed blocks having a stepped portion may be provided in the width direction of the multi-slit die coater. Therefore, precise control can be achieved without causing a coating gap deviation in the width direction. Therefore, management can be performed with uniform dimensional accuracy to stably and straighten uniform coating in the width direction of the wide current collector.

[0044] An appropriate coating gap range can be set according to the type of active material slurry. The present disclosure provides different types of fixed blocks with step portions of appropriate heights, and the process is performed by replacing the fixed blocks required for each production process, so even if a multi-slit die coater dedicated to each active material slurry is not included, a multi-slit die coater for general purposes can be used to accommodate various types of active material slurries. In addition, when there is dispersion in the active material slurry, the dispersion can be quickly dealt with by immediately replacing the fixed blocks and adjusting the coating gap.

[0045] As described above, when an electrode of a secondary battery is manufactured by coating an active material slurry on a current collector moving at high speed using the multi-slot die coater of the present disclosure, uniform coating can be achieved at high speed or in a wide range of coating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings illustrate preferred embodiments of the present disclosure, and together with the foregoing disclosure are used to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure should not be understood as being limited to the accompanying drawings.

[0047] Figure 1 1 is a schematic diagram showing an example of using a slot die coater according to the prior art.

[0048] Figure 2 is a cross-sectional view of a double slot die coater according to the prior art.

[0049] Figure 3 is a schematic cross-sectional view of a multi-slot die coater according to an embodiment of the present disclosure.

[0050] Figure 4 is a schematic exploded perspective view of a multi-slot die coater according to an embodiment of the present disclosure.

[0051] Figure 5 is included in Figure 3 A perspective view of a fixture block in a multi-slot die coater is shown.

[0052] Figure 6 is a rear view of a multi-slot die coater according to an embodiment of the present disclosure.

[0053] Figures 7 to 16is a schematic cross-sectional view of a multi-slot die coater according to other embodiments of the present disclosure.

[0054] Fig.17 is a schematic cross-sectional view of a multi-slot die coater according to another embodiment of the present disclosure.

[0055] Fig.18 is a schematic exploded perspective view of a multi-slot die coater according to another embodiment of the present disclosure.

[0056] Fig.19 is a rear view of a multi-slot die coater according to another embodiment of the present disclosure.

[0057] Figure 20 to Figure 26 is a schematic cross-sectional view of a multi-slot die coater according to other embodiments of the present disclosure. DETAILED DESCRIPTION

[0058] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as being limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to appropriately define the terms for the best interpretation. Therefore, the embodiments described herein and the descriptions in the accompanying drawings are only some preferred embodiments of the present invention and do not fully describe the technical features of the present disclosure, so it should be understood that various other equivalents and modifications may be made to the present disclosure when filing a patent application.

[0059] The multi-slit die coater of the present disclosure may include two or more slits. Basically, the multi-slit die coater is a device including a lower slit and an upper slit to coat a coating solution in a double layer on a substrate. The "substrate" described below is a current collector, and the coating solution is an "active material slurry". The first coating solution and the second coating solution are both active material slurries, and they may have the same or different compositions (types of active materials, conductive materials, and binders), amounts (amounts of each of active materials, conductive materials, and binders) or properties. The multi-slit die coater of the present disclosure is optimal for electrodes manufactured by simultaneously applying at least two types of active material slurries or by alternately applying at least two types of active material slurries. However, the scope of the present disclosure is not necessarily limited thereto. For example, the substrate may be a porous substrate constituting a diaphragm, and the first coating solution and the second coating solution may be organics having different compositions or properties. That is, in the case where thin film coating is required, the substrate, the first coating solution, and the second coating solution are not limited to a specific type.

[0060] Figure 3 is a schematic cross-sectional view of a multi-slot die coater according to an embodiment of the present disclosure.

[0061] Figure 4 is a schematic exploded perspective view of a multi-slot die coater according to an embodiment of the present disclosure.

[0062] Figure 5 is included in Figure 3 A perspective view of a fixture block in a multi-slot die coater is shown. Figure 6 is a rear view of a multi-slot die coater according to an embodiment of the present disclosure.

[0063] The multi-slot die coater 100 according to an embodiment of the present disclosure is a double-slot die coater including a lower slot 101 and an upper slot 102, and is a device capable of simultaneously or alternately coating the same type of coating solution or two different types of coating solutions on a substrate 300 through the lower slot 101 and the upper slot 102. Figure 3 and 4 The multi-slit die coater 100 includes a lower die block 110 , a middle die block 120 located on the lower die block 110 , and an upper die block 130 located on the middle die block 120 .

[0064] exist Figure 3 In the embodiment, the multi-slot die coater 100 is installed so that the direction in which the coating solution or the active material slurry appears is almost horizontal (in the X direction) (approximately: ±5°).

[0065] The middle mold block 120 is a block disposed in the middle of the blocks of the multi-slot die coater 100, and is a block interposed between the lower mold block 110 and the upper mold block 130 to form a multi-slot. The cross section of the middle mold block 120 of this embodiment is a right triangle, but its shape is not necessarily limited thereto, and for example, the cross section of the middle mold block 120 may be an isosceles triangle.

[0066] The first surface 120a of the middle mold block 120 in contact with the upper mold block 130 is placed almost horizontally, and the surface 130d opposite to the surface 130b of the upper mold block 130 facing the first surface 120a (i.e., the surface forming the upper surface of the outer peripheral surface of the multi-slit die coater 100) is also placed almost horizontally. As described above, the first surface 120a and the opposite surface 130d are almost parallel to each other. In addition, the surface 110d opposite to the surface 110b of the lower mold block 110 in contact with the middle mold block 120 (i.e., the surface forming the lower surface of the outer peripheral surface of the multi-slit die coater 100) is also placed almost horizontally, and this surface is the bottom surface 110d (XZ plane).

[0067] Surfaces of the lower mold block 110 , the middle mold block 120 , and the upper mold block 130 opposite to the direction in which the active material slurry emerges, ie, rear surfaces 110 c , 120 c , and 130 c are positioned almost vertically (Y direction).

[0068] Among the surfaces forming the outer peripheral surface of the multi-slit die coater 100 in the outermost lower mold block 110 and the upper mold block 130, the bottom surface 110d of the lower mold block 110 and the top surface 130d of the upper mold block 130 may be almost perpendicular to the rear surfaces 110c and 130c. In addition, the first surface 120a of the middle mold block 120 may be almost perpendicular to the rear surface 120c. In the lower mold block 110, the middle mold block 120 and the upper mold block 130, because the angles where the sides intersect are right angles, there are right angle parts in the cross section, and the vertical or horizontal plane can be used as a reference plane, so it is easy to manufacture or process, and it is possible to ensure accuracy. In addition, when combined together, the lower mold block 110, the middle mold block 120 and the upper mold block 130 have an approximately rectangular parallelepiped shape as a whole, and are inclined toward the substrate 300 only at the front side where the coating solution appears (see the surface 130a of the upper mold block 130, the surface 110a of the lower mold block 110). The assembled shape is similar to that including a single slit (e.g. Figure 1 The slot die coaters of 30) are roughly the same in shape and thus can share a slot die coater frame or the like.

[0069] Lower mold block 110 , middle mold block 120 and upper mold block 130 are not necessarily limited thereto, and may be configured as vertical molds, for example, so that the electrode active material slurry appears upward and rear surfaces 110 c , 120 c , 130 c are bottom surfaces.

[0070] The lower mold block 110, the middle mold block 120 and the upper mold block 130 are made of, for example, SUS material. Materials that are easy to process, such as SUS420J2, SUS630, SUS440C, SUS304, SUS316L, etc., can be used. SUS is easy to process, inexpensive, highly corrosion-resistant, and can be formed into a desired shape at low cost.

[0071] The lower die block 110 is the lowest block among the blocks of the multi-slot die coater 100 , and a surface 110 b facing the middle die block 120 is inclined at an angle of about 20° to 60° with respect to a bottom surface 110 d .

[0072] The lower slit 101 may be formed at a position where the lower mold block 110 and the middle mold block 120 contact each other. For example, the first spacer 113 is interposed between the lower mold block 110 and the middle mold block 120 to form a gap therebetween, and the lower slit 101 corresponding to a passage through which the first coating solution 50 may flow may be formed. In this case, the thickness of the first spacer 113 determines the vertical width (Y-axis direction, slit gap) of the lower slit 101.

[0073] like Figure 4 As shown, the first spacer 113 has a first opening portion 113a which is cut in one area and can be inserted in the remaining portion except one side in the edge area of ​​the facing surface of each of the lower mold block 110 and the middle mold block 120. Therefore, the lower outlet 101a through which the first coating solution 50 emerges is formed only between the front end of the lower mold block 110 and the front end of the middle mold block 120. The front ends of the lower mold block 110 and the middle mold block 120 are defined as the lower mold lip 111 and the middle mold lip 121, respectively. In other words, the lower outlet 101a is formed at the interval between the lower mold lip 111 and the middle mold lip 121.

[0074] For reference, the first spacer 113 serves as a gasket to prevent the first coating solution 50 from leaking through a gap between the lower mold block 110 and the middle mold block 120 except for a region where the lower outlet 101a is formed, and thus is preferably made of a material having sealing capability.

[0075] The lower mold block 110 includes a first manifold 112 having a predetermined depth on a surface 110b facing the middle mold block 120, and the first manifold 112 is communicated with the lower slit 101. The first manifold 112 is a space formed from the surface 110b of the lower mold block 110 in contact with the middle mold block 120 to a surface 110d opposite to the surface 110b. The first manifold 112 is connected to a first coating solution supply chamber (not shown) installed outside through a supply pipe, and supplies the first coating solution 50. When the first manifold 112 is completely filled with the first coating solution 50, the flow of the first coating solution 50 is guided along the lower slit 101 and comes out from the lower outlet 101a.

[0076] The upper mold block 130 is positioned to contact the first surface 120a, which is the upper surface of the middle mold block 120, parallel to the bottom surface. As described above, the upper slit 102 is formed at a position where the middle mold block 120 and the upper mold block 130 contact each other.

[0077] In the same manner as the above-described lower slit 101, the second spacer 133 may be interposed between the middle mold block 120 and the upper mold block 130 to form a gap therebetween. Thus, an upper slit 102 corresponding to a passage through which the second coating solution 60 may flow is formed. In this case, the vertical width (Y-axis direction, slit gap) of the upper slit 102 is determined by the second spacer 133.

[0078] In addition, in a similar manner to the first spacer 113, the second spacer 133 has a second opening portion 133a which is cut in one area and can be inserted in the remaining portion except for one side in the edge area of ​​the facing surface of each of the middle mold block 120 and the upper mold block 130. Likewise, the circumferential direction except for the front side of the upper slit 102 is blocked, and the upper outlet 102a is formed only between the front end of the middle mold block 120 and the front end of the upper mold block 130. The front end of the upper mold block 130 is defined as the upper mold lip 131, in other words, the upper outlet 102a is formed at the interval between the middle mold lip 121 and the upper mold lip 131.

[0079] In addition, the middle mold block 120 includes a second manifold 132 having a predetermined depth on a surface 120a facing the upper mold block 130, and the second manifold 132 is communicated with the upper slit 102. The middle mold block 120 has a second surface 120b opposite to the first surface 120a. The second surface 120b is a surface of the middle mold block 120 in contact with the lower mold block 110. The second manifold 132 is a space provided from the first surface 120a to the second surface 120b. Although not shown in the drawings, the second manifold 132 is connected to a supply chamber of the second coating solution 60 installed outside through a supply pipe, and supplies the second coating solution 60. When the second coating solution 60 is supplied from an external source along the supply pipe and the second manifold 132 is completely filled with the second coating solution 60, the flow of the second coating solution 60 is guided along the upper slit 102 communicated with the second manifold 132 and comes out from the upper outlet 102a.

[0080] The upper slit 102 and the lower slit 101 form an angle, which may be about 20° to 70°. The upper slit 102 and the lower slit 101 may intersect at one point, and the upper outlet 102a and the lower outlet 101a may be disposed near the intersection. Therefore, the positions where the first coating solution 50 and the second coating solution 60 appear may be concentrated at about one point.

[0081] Meanwhile, the angle θ between the first surface 120a of the intermediate mold block 120 in contact with the upper mold block 130 and the second surface 120b of the intermediate mold block 120 in contact with the lower mold block 110 is preferably within a range in which the active material slurry flowing out of the upper outlet 102a and the active material slurry flowing out of the lower outlet 101a do not form turbulence immediately after they flow out simultaneously. When the angle θ is too small, the intermediate mold block 120 is too thin and is easily deformed and distorted.

[0082] According to the multi-slot die coater 100 having such a configuration, the rotatable coating roller 200 is located at the front side of the multi-slot die coater 100, and the coating roller 200 can be rotated to move the substrate 300 to be coated while the first coating solution 50 and the second coating solution 60 are continuously in contact with the surface of the substrate 300, so that the substrate 300 can be coated in a double layer. Alternatively, pattern coating can be intermittently formed on the substrate 300 by performing the supply and stop of the first coating solution 50 and the supply and stop of the second coating solution 60 in an alternating manner.

[0083] Here, the multi-slit die coater further includes a fixing block 140, which is located on the rear surfaces 110c, 120c, 130c of the lower mold block 110, the middle mold block 120, and the upper mold block 130 on the side opposite to the front end, and the fixing block 140 is fixed to the rear surfaces of at least two of the lower mold block 110, the middle mold block 120, and the upper mold block 130 using two bolts 141 to couple the two mold blocks. The fixing block 140 includes a step portion 142 that protrudes toward the front end relative to a reference plane that is in close contact with the rear surface of any one of the two mold blocks, and the rear surface of the other mold block is in close contact with the step portion 142 to form a step between the rear surfaces of the two mold blocks coupled to the fixing block 140.

[0084] like Figure 5 As shown, the fixing block 140 has a reference plane 140a that is in close contact with the rear surface of any one of the two mold blocks, in this embodiment, the rear surface 120c of the middle mold block 120. In addition, the fixing block 140 has a step portion 142 that protrudes toward the front end relative to the reference plane 140a. The height of the step portion 142 is defined as a height h from the reference plane 140a. The fixing block 140 may further include a hole 143, through which the bolt 141 passes to tighten the bolt 141. The number and position of the holes 143 may be changed as shown in the figure. The cross-section of the fixing block 140 across the step portion 142 and the reference plane 140a may include a first cross-sectional portion and a second cross-sectional portion extending perpendicular to the first cross-sectional portion. For example, the cross-section of the fixing block 140 has Shape or "L" shape. This simple block shape does not complicate processing and can achieve precision processing. In addition, in the same manner as the lower mold block 110, the middle mold block 120, and the upper mold block 130, also in the fixed block 140, because the angles where the sides intersect are right angles, there are right-angled parts in the cross section, and the vertical or horizontal plane can be used as a reference plane, so it is easy to manufacture or handle, and the accuracy can be guaranteed. In addition, when the lower mold block 110, the middle mold block 120 and the upper mold block 130 are combined together and the fixed block 140 is tightened, the contact parts can support each other with high surface contact, so it is very good to tighten, fix and maintain.

[0085] In particular, in this embodiment, the first surface 120a of the middle mold block 120 in contact with the upper mold block 130 is placed almost horizontally, and the rear surface 120c of the middle mold block 120 and the rear surface 130c of the upper mold block 130 are placed almost vertically, so the contact surface between the middle mold block 120 and the upper mold block 130 forms almost a right angle with the rear surface 120c of the middle mold block 120. Therefore, the side wall of the step portion 142 extending from the reference plane 140a forms almost a right angle with the reference plane 140a. When the shapes of the middle mold block 120 and the upper mold block 130 are different from those of this embodiment, and thus the angle between the contact surface of the middle mold block 120 and the upper mold block 130 and the rear surface 120c of the middle mold block is out of a right angle, the angle between the side wall of the step portion 142 and the reference plane 140a may be changed accordingly.

[0086] Multi-slot die coaters can usually be made of SUS material. Generally, because the coupling surface of SUS components is prone to liquid leakage, leakage can be suppressed by placing a rubber ring or any other flexible material between the components to form a seal. However, this sealing method is not suitable for controlling uniform assembly types (such as assembly deviations less than 10μm), so it is difficult to apply to multi-slot die coaters.

[0087] Therefore, the multi-slit die coater requires a die block that is processed with very high precision (straightness, flatness ±5 μm) to be assembled by bolting. Liquid leakage needs to be prevented, and the bolting is a high pressure of about 200 to 350 N. However, high-pressure bolting may cause uneven micro-scale distribution of stress, causing deformation of the die block, and the die block is deformed or twisted under the pressure of the coating solution supplied during coating. A first cross-sectional portion and a second cross-sectional portion extending perpendicularly from the first cross-sectional portion and having, for example The fixing block 140 of 'L' shaped cross section is a structure capable of withstanding high pressure bolt tightening.

[0088] The fixing block 140 may be a single monolithic component, i.e., the fixing block 140 is not divided into a plurality of components. That is, the fixing block 140 is an integrally formed and seamless component. The precision during assembly can be improved, and due to the structural rigidity, high stability is provided to resist external impact during handling and use. If the fixing block 140 is not an integral component but is formed by assembling at least two separate components, each component will have a manufacturing tolerance, so after the components are assembled, the sum of the tolerances increases, making it difficult to align the components during assembly.

[0089] In this embodiment, the fixing block 140 couples the upper mold block 130 and the middle mold block 120. In addition, since the step portion 142 is in close contact with the rear surface 130c of the upper mold block 130, a step is formed between the rear surfaces 130c, 120c of the two upper mold blocks 130 and the middle mold block 120 coupled to the fixing block 140. Here, since the size of the step corresponds to the height h of the step portion 142, the step between the rear surfaces 130c, 120c of the two upper mold blocks 130 and the middle mold block 120 can be adjusted by adjusting the height h of the step portion 142. The step formed between the rear surfaces 130c, 120c of the two upper mold blocks 130 and the middle mold block 120 determines the position of the upper mold lip 131 and the middle mold lip 121 located at the front end of each upper mold block 130 and the middle mold block 120, and affects the coating gap.

[0090] Meanwhile, the multi-slit die coater 100 may further include a flat plate-shaped fixing portion 140' fixed to the rear surface 120c of the middle mold block 120 and the rear surface 110c of the lower mold block 110 using bolts 141. Figure 6 As shown, a plurality of fixing blocks 140 may be provided along the width direction of the multi-slit die coater 100. Bolts 141 are fastened to the fixing blocks 140, and by this, the middle mold block 120 and the upper mold block 130 are assembled. A flat plate-shaped fixing portion 140' may be provided between two fixing blocks 140. Bolts 141 are fastened to the flat plate-shaped fixing portion 140', and by this, the middle mold block 120 and the lower mold block 110 are assembled. In another example, the fixing block 140 may be provided between two flat plate-shaped fixing portions 140'. The fixing block 140 may reliably achieve uniform width-direction gap control by large surface contact of a device such as a block.

[0091] Since the upper mold block 130 and the middle mold block 120 are integrated into one by the structure of the fixed block 140, and the middle mold block 120 and the lower mold block 110 are integrated into one by the structure of the flat plate-shaped fixed portion 140', there is an effect that the upper mold block 130 slides relative to the middle mold block 120 toward the substrate 300, especially at the interface between the upper mold block 130 and the middle mold block 120, that is, the first surface 120a where the middle mold block 120 contacts the upper mold block 130, and the surface 130b of the upper mold block 130 facing the first surface 120a. Accordingly, the relative positions of the upper outlet 102a and the lower outlet 101a are adjusted to determine the coating gap. In contrast to the prior art, the coating gap can be easily determined by coupling the upper mold block 130, the middle mold block 120 and the fixed block 140. Therefore, the inconvenience of disassembling the upper mold block 130, the middle mold block 120 and the lower mold block 110 and adjusting the position each time to adjust the coating gap can be greatly reduced.

[0092] As an illustration, this embodiment shows that the length of the upper mold block 130 (the horizontal distance from the rear surface 130c to the upper mold lip 131) is shorter than the lengths of the middle mold block 120 and the lower mold block 110. In this state, when Figure 3 When the step is formed in the upper mold block 130 relative to the middle mold block 120, the lower mold lip 111, the middle mold lip 121 and the upper mold lip 131 can be arranged on the same straight line. In this case, various thin film coatings can be achieved by moving the entire multi-slit die coater 100 back and forth relative to the substrate 300.

[0093] According to the above-mentioned embodiment, a step is formed between the rear surfaces 130c, 120c of the upper mold block 130 and the middle mold block 120 by the fixing block 140 having the step portion 142. That is, the fixing block 140 already has the step portion 142 of a preset height h, the upper mold block 130 is coupled to the step portion 142, and the middle mold block 120 is coupled to other parts except the step portion 142, so that a step corresponding to the height h of the step portion 142 is naturally formed between the rear surfaces 130c, 120c of the upper mold block 130 and the middle mold block 120 by coupling. Therefore, the distance between the upper mold lip 131, the middle mold lip 121 and the substrate 300 at the front end of the upper mold block 130 and the middle mold block 120, that is, the coating gap can always be maintained at a desired level, and since the fixing block 140 is fixed between the upper mold block 130 and the middle mold block 120, once fixed, the coating gap does not change and remains unchanged during the process.

[0094] Therefore, when adjusting the coating gap, there is no need to disassemble and reassemble the upper mold block 130, the middle mold block 120, and the lower mold block 110, which are structurally fragile due to their small thickness, and a uniform coating gap can be always maintained through a simple operation of coupling the upper mold block 130 and the middle mold block 120 to the fixed block 140.

[0095] According to the present disclosure, considering that the mold block is deformed by the release pressure of the active material slurry, the coating amount and the resulting coating quality can be uniformly controlled by maintaining a uniform (±2%) coating gap. Therefore, by using a multi-slit die coater with a uniform coating gap, a coated product with uniform quality, particularly an electrode for a secondary battery, can be obtained.

[0096] As described above, according to the present disclosure, even if the pump pressure of the active material slurry increases, the adjusted coating gap can be maintained. Therefore, the processability and reproducibility of coating can be ensured.

[0097] Using the multi-slot die coater, a coating layer (particularly an active material layer) can be uniformly formed to a desired thickness, and preferably, two types of electrode active material slurries can be coated simultaneously, thereby achieving excellent performance and productivity.

[0098] Particularly, when a plurality of fixing blocks 140 having the step portion 142 are disposed in the width direction of the multi-slot die coater 100, precise control can be achieved without causing coating gap deviation in the width direction.

[0099] The appropriate range of the coating gap is set according to the type of active material slurry. The present disclosure includes a variety of fixed blocks having a step portion of an appropriate height h, and the process is performed by replacing the fixed blocks required for each production process, so that the multi-slit die coater can be used for general purposes without including each multi-slit die coater dedicated to each active material slurry to use various types of active material slurries. In addition, in the case where there is dispersion in the active material slurry, the dispersion can be quickly dealt with by replacing the fixed blocks.

[0100] As described above, using the multi-slot die coater of the present disclosure, when manufacturing an electrode of a secondary battery, uniform coating can be achieved under high-speed or wide coating conditions by coating the active material slurry on the current collector while moving the current collector.

[0101] Meanwhile, although the embodiment describes applying the coating solution in two layers or performing pattern coating by supplying the coating solution in an alternating manner, it is obvious that the present disclosure may include three or more slits to simultaneously coat three or more layers. It is obvious that three or more slits require four or more mold blocks.

[0102] Then, refer to Figures 7 to 16 Other embodiments of the present disclosure are described. The same reference numerals as those in the above-described embodiments denote the same elements, and repeated description of the same elements is omitted, and differences from the above-described embodiments are mainly described.

[0103] Figure 7 The multi-slot die coater shown Figure 3 The fixing block 140 shown and described in the figure extends to the rear surface 110c of the lower mold block 110, and thus the fixing block 140 is also coupled to the rear surface 110c of the lower mold block 110. As described above, the fixing block 140 is not limited to a specific shape and may have any shape for forming a step between the rear surfaces 130c, 120c of the two upper mold blocks 130 and the middle mold block 120 coupled to the fixing block 140. In addition, in this case, the upper mold block 130 and the middle mold block 120 are coupled by the fixing block 140, and a step is formed between their rear surfaces 130c, 120c, and furthermore, the lower mold block 110 is also coupled to the step, and thus the multi-slit die coater may not include a flat plate-shaped fixing portion fastened to the rear surface 120c of the middle mold block 120 and the rear surface 110c of the lower mold block 110 using the bolts 141 (see Figure 6 140'), and if necessary, a flat plate-shaped fixing portion may be further included in the fixing block 140.

[0104] and Figure 3 The Multi-Slot Die Coater 100, in contrast, Figure 8 The multi-slit die coater shown has a step D between the lower outlet 101a and the upper outlet 102a. When the length of the upper mold block 130 (the horizontal distance from the rear surface 130c to the upper mold lip 131) is equal to the lengths of the middle mold block 120 and the lower mold block 110, the upper mold lip 131 can be moved further forward to the substrate 300 than the middle mold lip 121 and the lower mold lip 111 by a height h of the step portion 142 of the fixed block 140. Therefore, the step D between the lower outlet 101a and the upper outlet 102a can be equal to the height h of the step portion 142 of the fixed block 140. When there is a step D between the lower outlet 101a and the upper outlet 102a, the lower outlet 101a and the upper outlet 102a are spaced apart from each other in the horizontal direction, thereby eliminating the risk of the second coating solution 60 flowing out of the upper outlet 102a entering the lower outlet 101a or the first coating solution 50 flowing out of the lower outlet 101a entering the upper outlet 102a.

[0105] That is, the coating solution flowing out through the lower outlet 101a or the upper outlet 102a is blocked by the surface of the step formed between the lower outlet 101a and the upper outlet 102a and thus does not enter the other outlet, thereby achieving a smoother multi-layer active material coating process.

[0106] Fig. 9 The step formed between the rear surface 130c of the upper mold block 130 and the rear surface 120c of the middle mold block 120 is Figure 3 The multi-slot die coater 100 is the same as Figure 3 On the contrary, the step portion 142 of the fixed block 140 is in close contact with the rear surface 120c of the middle mold block 120 instead of the rear surface 130c of the upper mold block 130. As described above, when a step is formed between the rear surfaces 130c, 120c of the two upper mold blocks 130 and the middle mold block 120, the step portion 142 of the fixed block 140 is in close contact with the rear surface of any one of the two upper mold blocks 130 and the middle mold block 120, and the mold block having the rear surface in close contact with the step portion 142 moves toward the substrate (see Figure 3 of 300).

[0107] Fig.10 and Fig. 9 Similar, and Fig.10 It is shown that the fixing block 140 extends only to the rear surface 110c of the lower mold block 110, and thus may also be coupled to the rear surface 110c of the lower mold block 110. In this case, the step portion 142 extends to the rear surface 110c of the lower mold block 110.

[0108] In the aforementioned embodiment, the rear surfaces opposite to the surfaces of the rear surfaces 130c, 120c of the upper mold block 130 and the middle mold block 120 coupled in the fixing block 140 are flat. Fig.11 As shown, a step portion 144 recessed toward the front end may be further formed on the rear surface of the fixing block 140 opposite to the surface coupled with the rear surfaces 130c, 120c of the upper mold block 130 and the middle mold block 120. As described above, when the fixing block 140 has the step portion 142 and the structure for coupling each of the upper mold block 130, the middle mold block 120, and the lower mold block 110 to support them, the fixing block 140 is not limited to a specific shape.

[0109] The above embodiment describes an example in which a step is formed between the rear surfaces 130c, 120c of the upper mold block 130 and the middle mold block 120. The step may be formed between any two of the upper mold block 130, the middle mold block 120, and the lower mold block 110.

[0110] As an example, Fig.12 and 13 140, thereby forming a step between the middle mold block 120 and the lower mold block 110. In this example, when the lengths of the upper mold block 130, the middle mold block 120, and the lower mold block 110 are equal, Figure 8 In contrast, the lower outlet 101a is moved further forward to the substrate than the upper outlet 102a (see Figure 3 300) to form a step between the lower outlet 101a and the upper outlet 102a. In this case, the lower mold lip 111 on the downstream side in the moving direction of the substrate 300 is closer to the substrate 300 than the upper mold lip 131 on the upstream side. Due to this feature, the lower mold lip 111 applies pressure to the first coating solution 50 flowing out of the lower outlet 101a and expands the first coating solution 50 in the width direction, and the thickness can be uniformly adjusted.

[0111] In addition, Fig.12 and 13 In the embodiment, the contact surface of the middle mold block 120 and the lower mold block 130 is inclined relative to the horizontal plane. Therefore, in the fixed block 140, the side wall of the step portion (see Figure 5 142) and the reference plane (see Figure 5 The angle between the middle mold block 120 and the lower mold block 130 is not a right angle, but the angle of the contact surface between the middle mold block 120 and the lower mold block 130.

[0112] Figures 14 to 16 An example of a fixed block 140 having a step is shown, so that the rear surface 120c of the middle mold block 120 moves forward further than the rear surfaces 130c, 110c of the other upper mold blocks 130 and the lower mold blocks 110 (see Figure 3 of 300).

[0113] Fig.17 is a schematic cross-sectional view of a multi-slot die coater according to another embodiment of the present disclosure, Fig.18 is a schematic exploded perspective view of a multi-slot die coater according to another embodiment of the present disclosure, and Fig.19 is a rear view of a multi-slot die coater according to another embodiment of the present disclosure.

[0114] A multi-slit die coater 100 ′ according to another embodiment of the present disclosure is an apparatus including a lower slit 101 and an upper slit 102 to simultaneously or alternately coat the same type of coating solution or two different types of coating solutions onto a substrate 300 through the lower slit 101 and the upper slit 102. Fig.17 and 18, the multi-slit die coater 100' includes a lower die A and an upper die B located on the lower die A. The lower die A includes a lower die block 110 and a first intermediate die block 122 located on the lower die block 110. The first intermediate die block 122 has a lower slit 101 between the first intermediate die block 122 and the lower die block 110. The upper die B includes a second intermediate die block 124 mounted on the first intermediate die block 122, and an upper die block 130 located on the second intermediate die block 124. The second intermediate die block 124 has an upper slit 102 between the second intermediate die block 124 and the upper die block 130.

[0115] exist Fig.17 In the embodiment, the multi-slit die coater 100' is installed so that the direction (X direction) in which the active material slurry or coating solution appears is almost horizontal (approximately: ±5°). The first intermediate mold block 122 and the second intermediate mold block 124 form the intermediate mold block 120. The intermediate mold block 120 is a mold block in the middle of the mold blocks of the multi-slit die coater 100', and is located between the lower mold block 110 and the upper mold block 130. The cross-section of the intermediate mold block 120 of this embodiment is a substantially right-angled shape, but is not limited to this, and can also be set to a shape such as an isosceles triangle in cross-section. In the intermediate mold block 120, the first intermediate mold block 122 and the second intermediate mold block 124 contact each other in the vertical direction, and move relative to each other by sliding along the contact surface.

[0116] The first surface 124a of the second intermediate mold block 124 in contact with the upper mold block 130 is placed almost horizontally, and the second surface 124b of the second intermediate mold block 124 opposite to the first surface 124a is in close contact with the first surface 122a of the first intermediate mold block 122, and moves relatively along the contact surface therebetween. The second surface 122b of the first intermediate mold block 122 opposite to the first surface 122a is in contact with the lower mold block 110.

[0117] The first surface 124a of the second intermediate mold block 124 in contact with the upper mold block 130 is placed almost horizontally, and the surface 130d opposite to the surface 130b facing the first surface 124a in the upper mold block 130 (i.e., the surface forming the upper surface of the outer peripheral surface of the multi-slit die coater 100') is also placed almost horizontally. Therefore, the first surface 124a and the opposite surface 130d are almost parallel. In addition, the surface 110d opposite to the surface 110b of the lower mold block 110 in contact with the first intermediate mold block 122 (i.e., the surface forming the lower surface of the outer peripheral surface of the multi-slit die coater 100') is also placed almost horizontally, and this surface is the bottom surface 110d (XZ plane).

[0118] The surfaces opposite to the direction in which the active material slurry appears in the lower mold block 110, the first and second intermediate mold blocks 122, 124 and the upper mold block 130, that is, the rear surfaces 110c, 122c, 124c, 130c are almost vertically disposed (Y direction).

[0119] In the outermost mold blocks, i.e., the lower mold block 110 and the upper mold block 130, among the surfaces forming the outer peripheral surface of the multi-slit die coater 100', the bottom surface 110d of the lower mold block 110 and the top surface 130d of the upper mold block 130 may be almost perpendicular to the rear surfaces 110c, 130c. In addition, the first surface 124a of the second intermediate mold block 124 may be almost perpendicular to the rear surface 124c. In the lower mold block 110, the intermediate mold block 124, and the upper intermediate mold block 130, since the angles at which the sides intersect are right angles, there are right angle portions in the cross section, and a vertical plane or a horizontal plane may be used as a reference plane, so it is easy to manufacture or process and it is possible to ensure accuracy. Furthermore, when assembled together, the lower mold block 110, the first and second intermediate mold blocks 122 and 124, and the upper mold block 130 have an approximately rectangular parallelepiped shape as a whole, and are inclined toward the substrate 300 only at the front side where the coating solution appears (see the surface 130a of the upper mold block 130, the surface 110a of the lower mold block 110). The assembled shape is roughly similar to a slot die coater including a single slot (e.g., Figure 1 30), and thus can share a slot die coater support or the like.

[0120] The lower mold block 110, the first and second intermediate mold blocks 122, 124 and the upper mold block 130 are not necessarily limited thereto, and for example, may be configured as a vertical mold such that the direction in which the active material slurry emerges is upward, and the rear surfaces 110c, 122c, 124c, 130c are bottom surfaces.

[0121] The lower mold block 110 is the lowest block among the blocks of the multi-slot die coater 100 ′, and a surface 110 b facing the first middle mold block 122 is inclined at an angle of about 20 to 60° with respect to a bottom surface 110 d .

[0122] The lower slit 101 may be formed at a position where the lower mold block 110 and the first intermediate mold block 122 contact each other. For example, the first spacer 113 may be interposed between the lower mold block 110 and the first intermediate mold block 122 to provide a gap therebetween, and thus the lower slit 101 corresponding to a passage through which the first coating solution 50 may flow may be formed. In this case, the thickness of the first spacer 113 determines the vertical width (Y-axis direction, slit gap) of the lower slit 101.

[0123] like Fig.18As shown, the first spacer 113 has a first opening portion 113a which is cut in one area and can be inserted in the remaining portion except one side in the edge area of ​​the facing surface of each of the lower mold block 110 and the first intermediate mold block 122. Therefore, the lower outlet 101a through which the first coating solution 50 emerges is formed only between the front end of the lower mold block 110 and the front end of the first intermediate mold block 122. The front end of the lower mold block 110 and the front end of the first intermediate mold block 120 are defined as the lower mold lip 111 and the first intermediate mold lip 121a, respectively, that is, the lower outlet 101a can be formed by the space between the lower mold lip 111 and the first intermediate mold lip 121a.

[0124] For reference, except for the region where the lower outlet 101a is formed, the first spacer 113 serves as a gasket to prevent the first coating solution 50 from leaking through the gap between the lower mold block 110 and the first middle mold block 122. It is therefore preferably made of a material having sealing ability.

[0125] The lower mold block 110 includes a first manifold 112 having a predetermined depth on a surface 110b facing the first middle mold block 122, and the first manifold 112 is communicated with the lower slit 101. The first manifold 112 is a space formed from the surface 110b of the lower mold block 110 in contact with the first middle mold block 122 to a surface 110d opposite to the surface 110b. The first manifold 112 is connected to a first coating solution supply chamber (not shown) installed outside through a supply pipe and supplies the first coating solution 50. When the first manifold 112 is completely filled with the first coating solution 50, the flow of the first coating solution 50 is guided along the lower slit 101 and comes out from the lower outlet 101a.

[0126] The upper mold block 130 is positioned to contact the first surface 124a, which is the upper surface of the second intermediate mold block 124, parallel to the bottom surface. As described above, the upper slit 102 is formed at a position where the second intermediate mold block 124 and the upper mold block 130 contact each other.

[0127] In the same manner as the above-described lower slit 101, the second spacer 133 may be interposed between the second intermediate mold block 124 and the upper mold block 130 to provide a gap therebetween. Thus, an upper slit 102 corresponding to a passage through which the second coating solution 60 may flow is formed. In this case, the vertical width (Y-axis direction, slit gap) of the upper slit 102 is determined by the second spacer 133.

[0128] In addition, the second spacer 133 has a similar structure to the first spacer 113, and includes a second opening portion 133a which is cut at one area and inserted in the remaining area except one side of the edge area of ​​the facing surface of each of the second intermediate mold block 124 and the upper mold block 130. Likewise, the circumferential direction except the front side of the upper slit 102 is blocked, and the upper outlet 102a is formed only between the front end of the second intermediate mold block 124 and the upper mold block 130. The front end of the second intermediate mold block 124 is defined as the second intermediate mold lip 121b, and the front end of the upper mold block 130 is defined as the upper mold lip 131, that is, the upper outlet 102a may be formed by the space between the second intermediate mold lip 121b and the upper mold lip 131.

[0129] In addition, the second intermediate mold block 124 includes a second manifold 132 having a predetermined depth on a first surface 124a facing the upper mold block 130, and the second manifold 132 is communicated with the upper slit 102. The second intermediate mold block 124 has a second surface 124b facing the first surface 120a. The second surface 124b is a surface of the second intermediate mold block 124 in contact with the first intermediate mold block 122. The second manifold 132 is a space formed from the first surface 124a to the second surface 124b. Although not shown in the drawings, the second manifold 132 is connected to a supply chamber for the second coating solution 60 installed outside through a supply pipe, and supplies the second coating solution 60. When the second coating solution 60 is supplied from an external source along the supply pipe and the second manifold 132 is completely filled with the second coating solution 60, the flow of the second coating solution 60 is guided along the upper slit 102 communicated with the second manifold 132 and comes out from the upper outlet 102a.

[0130] Meanwhile, the angle θ between the first surface 124a of the second intermediate mold block 124 in contact with the upper mold block 130 and the second surface 122b of the first intermediate mold block 122 in contact with the lower mold block 110 is preferably within a range in which the active material slurry flowing out of the upper outlet 102a and the active material slurry flowing out of the lower outlet 101a do not form turbulence immediately after they flow out simultaneously. When the angle θ is too small, the intermediate mold block 120 is too thin and is easily deformed and distorted.

[0131] In addition, the multi-slit die coater further includes a fixing block 140, which is fastened to rear surfaces 110c, 122c, 124c, and 130c of the lower mold block 110, the first intermediate mold block 122, the second intermediate mold block 124, and the upper mold block 130 on surfaces opposite to the front ends of the lower mold A and the upper mold B using bolts 141 to couple the lower mold A and the upper mold B.

[0132] The fixing block 140 and Figure 3As shown, the fixing block 140 includes a step portion 142, which protrudes toward the front end relative to a reference plane that is in close contact with the rear surface of any one of the mold blocks of the lower mold A and the upper mold B, and the rear surface of the other mold of the lower mold A and the upper mold B is in close contact with the step portion 142, thereby forming a step between the rear surfaces of the lower mold A and the upper mold B coupled to the fixing block 140.

[0133] In this embodiment, the fixing block 140 couples the first intermediate mold block 122 and the second intermediate mold block 124. In addition, since the step portion 142 is in close contact with the rear surface 124c of the second intermediate mold block 124, a step portion is formed between the rear surfaces 122c, 124c of the two first intermediate mold blocks 122 and the second intermediate mold block 124 coupled to the fixing block 140. Here, since the size of the step corresponds to the height h of the step portion 142, the step between the rear surfaces 122c, 124c of the two first intermediate mold blocks 122 and the second intermediate mold block 124 can be adjusted by adjusting the height h of the step portion 142. The step formed between the rear surfaces 122c, 124c of the two first intermediate mold blocks 122 and the second intermediate mold block 124 determines the position of the first intermediate mold lip 121a and the position of the second intermediate mold lip 121b at the front end of each of the first intermediate mold blocks 122 and the second intermediate mold block 124, and it affects the coating gap.

[0134] Meanwhile, the multi-slot die coater may further include a flat plate-shaped fixing portion 140', which is fastened to the rear surface 130c of the upper mold block 130 and the rear surface 124c of the second middle mold block 124 using bolts 141, and a flat plate-shaped fixing portion 140" which is fastened to the rear surface 122c of the first middle mold block 122 and the rear surface 110c of the lower mold block 110 using bolts 141. A plurality of fixing blocks 140 may be provided along the width direction of the multi-slot die coater 100', such as Fig.19 As shown. Bolt 141 is fastened to the fixed block 140, whereby the lower mold A and the middle mold B are assembled. The flat plate-shaped fixed portion 140' may be disposed between the two fixed blocks 140. Bolt 141 is fastened to the flat plate-shaped fixed portion 140', whereby the upper mold block 130 and the second middle mold block 124 are assembled. In another example, the fixed block 140 may be disposed between the two flat plate-shaped fixed portions 140'. Bolt 141 is fastened to the flat plate-shaped fixed portion 140", whereby the first middle mold block 122 and the lower mold block 110 are assembled. In yet another example, the fixed block 140 may be disposed between the two flat plate-shaped fixed portions 140". The fixed block 140 can reliably achieve uniform width-direction gap control through large surface contact of a device such as a block.

[0135] The upper mold block 130 and the second intermediate mold block 124 are fixed and coupled to each other by the structure of the flat plate-shaped fixing portion 140', and the first intermediate mold block 122 and the lower mold block 110 are fixed and coupled to each other by the structure of the flat plate-shaped fixing portion 140". Therefore, the upper mold block 130 and the second intermediate mold block 124 can move together, and the first intermediate mold block 122 and the lower mold block 110 can move together. That is, a first plane formed on the lower mold A (in this embodiment, the first surface 122a of the first intermediate mold block 122) and a second plane formed below the upper mold B (in this embodiment, the second surface 124b of the second intermediate mold block 124) are in contact with each other to form a sliding surface, and the upper mold B and the lower mold A are installed so that either mold slides along the sliding surface and moves relatively in the horizontal direction.

[0136] When the relative position between the lower outlet 101a and the upper outlet 102a needs to be changed, the multi-slit die coater 100' according to the embodiment of the present disclosure can be simply adjusted by sliding movement of the lower mold A and / or the upper mold B without disassembling and reassembling each of the lower mold block 110, the middle mold block 120, and the upper mold block 130, thereby significantly improving the workability. The relative position of the upper outlet 102a and the lower outlet 101a is adjusted, and the coating gap is determined because the fixing block 140 is coupled between the lower mold A and the upper mold B. Therefore, the inconvenience of disassembling the upper mold block 130, the first middle mold block 122, the second middle mold block 124, the lower mold block 110 and adjusting the position to adjust the coating gap each time can be greatly reduced.

[0137] As an illustration, this embodiment shows that the length of the upper mold B (e.g., the horizontal distance from the rear surface 130c of the upper mold block 130 to the upper mold lip 131) is shorter than the length of the lower mold A (e.g., the horizontal distance from the rear surface 110c of the lower mold block 110 to the lower mold lip 111). In this state, as Fig.17 As shown, when the rear surface of the upper mold B forms a step with respect to the rear surface of the lower mold A, the lower mold lip 111, the first and second intermediate mold lips 121a and 121b, and the upper mold lip 131 may be arranged on the same straight line. In this case, various film coatings may be performed by moving the entire multi-slot die coater 100' back and forth with respect to the substrate 300.

[0138] According to the above-described embodiment, a step is formed between the rear surfaces of the upper mold B and the lower mold A by the fixing block 140 having the step portion 142. That is, the fixing block 140 already has the step portion 142 of a preset height h, and the second intermediate mold block 124 is coupled to the step portion 142 and the first intermediate mold block 122 is coupled to other parts except the step portion 142, so a step corresponding to the height h of the step portion 142 is naturally formed between the rear surfaces 124c, 123c of the second intermediate mold block 124 and the first intermediate mold block 122 by coupling. Therefore, the distance between the first intermediate mold lip 121a and the second intermediate mold lip 121b at the front end of the second intermediate mold block 124 and the first intermediate mold block 122 and the substrate 300, that is, the coating gap can always be maintained at a desired level, and since the fixing block 140 is fixed between the second intermediate mold block 124 and the first intermediate mold 122, once set, the coating gap does not change and remains unchanged during the process.

[0139] Therefore, when adjusting the coating gap, there is no need to disassemble and reassemble the upper mold block 130, the second intermediate mold block 124, the first intermediate mold block 122, and the lower mold block 110, which are structurally fragile due to their small thickness, and a uniform coating gap can be always maintained through a simple operation of coupling the second intermediate mold block 124 and the first intermediate mold block 122 to the fixed block 140.

[0140] Then, refer to Figure 20 to Figure 26 Other embodiments of the present disclosure are described. The same reference numerals as those in the previous embodiment denote the same elements, repeated description of the same elements is omitted, and differences from the previous embodiment are mainly described.

[0141] Fig. 20 The multi-slot die coater shown Fig.17 The fixing block 140 shown and described in the drawing extends to the rear surface 110c of the lower mold block 110, and thus the fixing block 140 is also coupled to the rear surface 110c of the lower mold block 110. As described above, the fixing block 140 is not limited to a specific shape and may have any shape to form a step between the rear surfaces 124c, 122c of the second intermediate mold block 124 and the first intermediate mold block 122 connected to the fixing block 140. Furthermore, in this case, when the second intermediate mold block 124 and the first intermediate mold block 122 are coupled by the fixing block 140, a step may be formed between the rear surfaces 124c, 122c, and the lower mold block 110 may also be coupled, and thus the multi-slit die coater may not include a flat plate-shaped fixing portion fastened to the rear surface 122c of the first intermediate mold block 122 and the rear surface 110c of the lower mold block 110 using the bolts 141 (see Fig.19140"), and if necessary, a flat plate-shaped fixing portion may be further included in the fixing block 140.

[0142] Fig.21 The multi-slot die coater shown Fig.17 The fixing block 140 shown and described in the drawing extends to the rear surface 130c of the upper mold block 130, and thus the fixing block 140 is also coupled to the rear surface 130c of the upper mold block 130. As described above, the fixing block 140 is not limited to a specific shape and may have any shape for forming a step between the rear surfaces 124c, 122c of the two second intermediate mold blocks 124 and the first intermediate mold block 122 coupled to the fixing block 140. Furthermore, in this case, when the second intermediate mold block 124 and the first intermediate mold block 122 are coupled by the fixing block 140, a step may be formed between their rear surfaces 124c, 122c, and the upper mold block 130 is also coupled, and thus the multi-slit die coater may not include a flat plate-shaped fixing portion that is fastened to the rear surface 122c of the upper mold block 130 and the rear surface 124c of the second intermediate mold block 124 using the bolts 141 (see Fig.19 140), and if necessary, a flat plate-shaped fixing portion may be further included in the fixing block 140.

[0143] and Fig.17 The Multi-Slot Die Coater 100', in contrast, Fig. 22 The multi-slit die coater shown has a step D between the lower outlet 101a and the upper outlet 102a. When the length of the upper mold B is equal to that of the lower mold A, the upper mold lip 131 and the second middle mold lip 121b may be moved further forward to the substrate 30 than the first middle mold lip 121a and the lower mold lip 111 by a height h of the step portion 142 of the fixing block 140. Therefore, the step D between the lower outlet 101a and the upper outlet 102a may be equal to the height h of the step portion 142 of the fixing block 140. When the step D is formed between the lower outlet 101a and the upper outlet 102a, the lower outlet 101a and the upper outlet 102a are spaced apart from each other in the horizontal direction, so there is no risk that the second coating solution 60 flowing out of the upper outlet 102a may enter the lower outlet 101a or the first coating solution 50 flowing out of the lower outlet 101a may enter the upper outlet 102a.

[0144] That is, there is no risk that the coating solution flowing out through the lower outlet 101a or the upper outlet 102a is blocked by the surface forming a step between the lower outlet 101a and the upper outlet 102a and enters the other outlet, thereby performing a smoother multi-layer active material coating process.

[0145] As described above, the multi-slot die coater 100' has two outlets 101a, 102a and can be used to form two active material layers on the current collector, and in order to smoothly coat the active material slurry, the two outlets 101a, 102a can be set at front and rear positions, spaced apart from each other in the horizontal direction. The relative movement of the lower mold A and the upper mold B can be performed using a separate device for adjusting the shape of the multi-slot die coater 100' or by a manual task of an operator.

[0146] For example, by moving the upper mold B by a preset distance D in the same positive direction as the direction in which the active material slurry appears along the sliding surface without moving the lower mold A, a step can be formed between the lower outlet 101a and the upper outlet 102a. In addition, the step is maintained by tightening the fixing block 140. The width D of the step may be determined in the range of approximately several micrometers to several millimeters and may be determined based on the thickness of the active material layer formed on the current collector. For example, as the thickness of the active material layer to be formed on the current collector increases, the width D of the step may increase.

[0147] exist Fig.23 In the embodiment, the position where the step is formed between the rear surface of the upper mold B and the rear surface of the lower mold A is Fig.17 The position of the multi-slot die coater 100 ′ is the same as that of the multi-slot die coater 100 ′, but the step portion 142 of the fixing block 140 is in close contact with the rear surface 120 c of the first intermediate mold block 122 instead of the rear surface 124 c of the second intermediate mold block 124 .

[0148] When a step is formed between the rear surfaces 124c, 122c of the two second intermediate mold blocks 124 and the first intermediate mold block 122, the step portion 142 of the fixing block 140 can be in close contact with the rear surface of any one of the two second intermediate mold blocks 124 and the first intermediate mold block 122. The mold block having the rear surface in close contact with the step portion 142 moves forward to the substrate (see Fig.17 of 300).

[0149] In this example, when the length of the upper mold B is equal to the length of the lower mold A, Fig. 22 On the contrary, the lower outlet 101a moves further forward to the substrate 300 than the upper outlet 102a to form a step between the lower outlet 101a and the upper outlet 102a. In this case, the lower mold lip 111 on the downstream side in the moving direction of the substrate 300 is closer to the substrate 300 than the upper mold lip 131 on the upstream side. Due to this feature, the thickness can be uniformly adjusted by applying pressure to the first coating solution 50 flowing out of the lower outlet 101a by the lower mold lip 111 and expanding the first coating solution 50 in the width direction.

[0150] Fig.24 Similar to Fig.23 , Fig.24 1 is an embodiment showing that the fixing block 140 extends only to the rear surface 110c of the lower mold block 110 and thus may also be coupled to the rear surface 110c of the lower mold block 110. In this case, the step portion 142 extends to the rear surface 110c of the lower mold block 110.

[0151] also, Fig.25 Similar to Fig.23 . Fig.25 1 is an embodiment showing that the fixing block 140 extends only to the rear surface 130 c of the upper mold block 130 , and thus may also be coupled to the rear surface 130 c of the upper mold block 130 .

[0152] In the aforementioned embodiment, the rear surface opposite to the surface coupled to the rear surfaces 124c, 122c of the second and first intermediate mold blocks 124, 122 in the fixing block 140 is flat. Fig.26 As shown, a step portion 144 recessed toward the front end may be further formed on the rear surface of the fixing block 140 opposite to the surface coupled with the rear surfaces 124c, 122c of the second intermediate mold block 124 and the first intermediate mold block 122. As described above, when the fixing block 140 has the step portion 142 and the structure for coupling each of the upper mold block 130, the second intermediate mold block 124, the first intermediate mold block 122, and the lower mold block 110 to support them, the fixing block 140 is not limited to a specific shape.

[0153] Therefore, when it is necessary to change the relative position between the lower outlet and the upper outlet depending on the thickness of the active material layer coated on the current collector, the slot die coater 100' according to another embodiment of the present disclosure can be simply adjusted by sliding movement of the lower mold and / or the upper mold, and compared with the conventional slot die coater, there is no need to disassemble and reassemble each mold block, thereby significantly improving the workability. In particular, the step can be set and maintained to have a desired coating gap by a simple operation of tightening the fixing block 140.

[0154] Although the present disclosure has been described with respect to a limited number of embodiments and drawings, the present disclosure is not limited thereto, and it is apparent to those skilled in the art that various changes and modifications may be made thereto within the technical aspects of the present disclosure and the appended claims and their equivalent scopes.

[0155] Meanwhile, although terms indicating directions such as up, down, left and right are used in this specification, these terms are for convenience of description only, and it is obvious to those skilled in the art that these terms may change depending on the position of the target object or the position of the observer.

Claims

1. A multi-slot die coater comprising a lower slit and an upper slit, the multi-slot die coater comprising: Lower mold block; an intermediate mold block located on the lower mold block such that the lower slit is formed between the intermediate mold block and the lower mold block; and an upper mold block, located on the middle mold block, so that the upper slit is formed between the upper mold block and the middle mold block, wherein the lower mold block, the middle mold block and the upper mold block respectively include a lower mold lip, a middle mold lip and an upper mold lip forming their respective front ends, wherein the multi-slit die coater further comprises a fixing block, the fixing block being located on the rear surfaces of the lower die block, the middle die block and the upper die block on a side opposite to the front end, the fixing block being fixed to the rear surfaces of at least two of the lower die block, the middle die block and the upper die block by bolts to couple the two die blocks, wherein the fixing block includes a step portion that protrudes toward the front end relative to a reference plane that is in close contact with a rear surface of any one of the two mold blocks, and a rear surface of the other of the two mold blocks is in close contact with the step portion to form a step between rear surfaces of the two mold blocks coupled to the fixing block, and wherein the fixing block couples the upper mold block to the middle mold block, and the step portion is in close contact with a rear surface of the upper mold block or a rear surface of the middle mold block. 2 . The multi-slot die coater according to claim 1 , wherein the fixing block extends to a rear surface of the lower mold block and thus the fixing block is also coupled to the rear surface of the lower mold block. 3 . The multi-slot die coater according to claim 1 , further comprising a flat plate-shaped fixing portion fixed to rear surfaces of the middle mold block and the lower mold block with bolts. 4 . The multi-slot die coater of claim 1 , wherein the fixing block couples the middle mold block to the lower mold block, and the step portion is in close contact with a rear surface of the middle mold block or a rear surface of the lower mold block. 5 . The multi-slot die coater according to claim 4 , wherein the fixing block extends to a rear surface of the upper mold block and thus the fixing block is also coupled to the rear surface of the upper mold block. 6 . The multi-slot die coater according to claim 4 , further comprising a flat plate-shaped fixing portion fixed to rear surfaces of the upper mold block and the middle mold block with bolts.

7. The multi-slit die coater according to claim 1, wherein the fixing block couples the upper mold block to the middle mold block, the step portion is in close contact with a rear surface of the upper mold block, and the upper mold block is shorter in length than the middle mold block and the lower mold block.

8. A multi-slit die coater comprising: A lower mold including a lower slit, and an upper mold located on the lower mold, the upper mold including an upper slit, wherein a plane formed on the lower mold and a second plane formed below the upper mold contact each other to form a sliding surface, and the upper mold and the lower mold are installed so that any one of the upper mold and the lower mold slides along the sliding surface to make relative movement in the horizontal direction, The multi-slot die coater further includes a fixing block on a rear surface on a side opposite to front ends of the lower mold and the upper mold, the fixing block being fixed to rear surfaces of the lower mold and the upper mold with bolts to couple the lower mold to the upper mold, and a fixing block including a step portion that protrudes toward the front end relative to a reference plane that is in close contact with a rear surface of any one of the lower mold and the upper mold, and when a rear surface of the other of the lower mold and the upper mold is in close contact with the step portion, a step is formed between the rear surfaces of the lower mold and the upper mold coupled to the fixing block, The lower mold comprises a lower mold block and a first intermediate mold block located on the lower mold block, so that a lower slit is formed between the first intermediate mold block and the lower mold block. the upper mold includes a second intermediate mold block mounted on the first intermediate mold block and an upper mold block placed on the second intermediate mold block so that an upper slit is formed between the upper mold block and the second intermediate mold block, and wherein the fixing block couples the first intermediate mold block to the second intermediate mold block, and the step portion is in close contact with a rear surface of the second intermediate mold block or a rear surface of the first intermediate mold block. 9 . The multi-slot die coater of claim 8 , wherein the fixing block extends to a rear surface of the lower mold block so that the fixing block is also coupled to the rear surface of the lower mold block.

10. The multi-slot die coater of claim 8, wherein the fixing block extends to a rear surface of the upper mold block so that the fixing block is also coupled to the rear surface of the upper mold block.

11. The multi-slit die coater according to claim 8, further comprising a flat plate-shaped fixing portion fixed to the rear surface of the upper mold block and the rear surface of the second middle mold block with bolts, or a flat plate-shaped fixing portion fixed to the rear surface of the first middle mold block and the rear surface of the lower mold block with bolts. 12 . The multi-slot die coater of claim 8 , wherein the step portion is in close contact with a rear surface of the second intermediate mold block, and the upper mold is shorter in length than the lower mold. 13 . The multi-slot die coater according to claim 1 or 8 , wherein a plurality of fixing blocks are provided in a width direction of the multi-slot die coater.

14. The multi-slot die coater according to claim 1 or 8, wherein a section of the fixing block spanning the step portion and the reference plane includes a first section portion and a second section portion extending perpendicularly to the first section portion.

Images