JP6873015B2 - Coating equipment and coating method - Google Patents

Description

The present invention relates to a coating technique for intermittently coating a coating liquid on a base material.

As an apparatus for performing such intermittent coating, Patent Document 1 provides two coating means on the die of the coating head before and after the supply direction of the continuously supplied medium, and from each slit of each coating means. A coating device that independently discharges a coating liquid is disclosed. The device alternately activates each coating means, forms a coating pattern with the upstream coating means, and then intermittently coats the coating liquid on the medium by forming the coating pattern with the downstream coating means. .. As a result, the apparatus aims to increase the operating interval of each coating means to improve the processing speed of intermittent coating even when the spacing between coating patterns is small.

Japanese Unexamined Patent Publication No. 10-43659

However, in the coating apparatus of Patent Document 1, since the distance between each discharge port at the slit tip of the two discharge means and the base material is the same, the coating pattern applied by the coating means on the upstream side is coated on the downstream side. There is a problem that the means come into contact with each other and damage the coating pattern.

The present invention has been made to solve such a problem, and it is possible to prevent damage to the coating film when the coating liquid is intermittently applied on the base material to form the coating film. The purpose is to provide the technology that can be used.

In order to solve the above problems, the coating device according to the first aspect is a coating device that intermittently coats a long strip-shaped base material, and transports the base material in the longitudinal direction. A first coating head which is arranged on one surface side of the base material and has a slit-shaped first discharge port which extends in a direction orthogonal to the longitudinal direction along the one surface and faces the one surface. And, it is arranged on the one side of the first coating head on the downstream side in the transport direction of the base material by the transport portion, and extends along the one surface in a direction orthogonal to the longitudinal direction. By intermittently supplying the coating liquid to each of the second coating head having a slit-shaped second discharge port facing the direction, the first coating head, and the second coating head. A coating liquid supply mechanism that intermittently discharges the coating liquid from each of the first coating head and the second coating head toward the one surface of the base material, and the first coating. A second coating is applied to each of the plurality of regions on the one surface sandwiched between the coating films adjacent to each other among the plurality of coating films intermittently formed on the one surface of the base material by the head. A control unit that controls the coating liquid supply mechanism so as to form a coating film by the head is provided, and the first discharge port of the first coating head and the first discharge of the one surface are provided. The distance between the second discharge port of the second coating head and the second portion of the one surface on which the second discharge port faces is longer than the distance between the first portion facing the outlet.

The coating device according to the second aspect is the coating device according to the first aspect, and the second coating head is a tip portion on the upstream side in the transport direction that defines the second discharge port. The distance between the upstream end portion and the second portion of the one surface of the base material, including the downstream tip portion, and the distance between the downstream tip portion and the second portion are different.

The coating device according to the third aspect is the coating device according to the second aspect, in which the upstream tip portion of the second coating head is more than the downstream tip portion of the base material. Close to the direction.

The coating device according to the fourth aspect is the coating device according to the second aspect, in which the downstream tip portion of the second coating head is more than the upstream tip portion of the base material. Close to the direction.

The coating method according to the fifth aspect is a coating method in which a long strip-shaped base material is intermittently coated, and is a transport step of transporting the base material in the longitudinal direction and one surface of the base material. From the first coating head arranged on the side and having a slit-shaped first discharge port extending in a direction orthogonal to the longitudinal direction along the one surface and facing the one surface, and the first coating head. Is also arranged on the one side on the downstream side in the transport direction of the base material in the transport step, and extends along the one surface in a direction orthogonal to the longitudinal direction and faces the one surface. A coating liquid discharge step of intermittently discharging the coating liquid in parallel with the transfer step from each of the second coating head having a discharge port toward the one surface of the base material is provided. In the coating liquid discharge step, the one surface sandwiched between the coating films adjacent to each other among a plurality of coating films intermittently formed on the one surface of the base material by the first coating head. In the step of discharging the coating liquid from each of the first coating head and the second coating head so that the coating film is formed by the second coating head in each of the above plurality of regions. Yes, the second discharge port of the second coating head and the second discharge port of the second coating head are more than the distance between the first discharge port of the first coating head and the first portion of the one surface on which the first discharge port faces. The distance between the one surface and the second portion facing the second discharge port is long.

The coating method according to the sixth aspect is the coating method according to the fifth aspect, and the second coating head is a tip portion on the upstream side in the transport direction that defines the second discharge port. The distance between the upstream end portion and the second portion of the one surface of the base material, including the downstream tip portion, and the distance between the downstream end portion and the second portion are different.

The coating method according to the seventh aspect is the coating method according to the sixth aspect, wherein the upstream end portion of the second coating head is more than the downstream end portion of the base material. Close to the direction.

The coating method according to the eighth aspect is the coating method according to the sixth aspect, wherein the downstream tip portion of the second coating head is the one of the base material rather than the upstream tip portion. Close to the direction.

The coating method according to the ninth aspect is the coating method according to the fifth aspect, and the second coating head is a tip portion on the upstream side in the transport direction that defines the second discharge port. The coating method includes a downstream tip portion, and the coating method includes a first distance between the upstream tip portion of the second coating head and the second portion of the one surface of the base material, and the second coating. The upstream tip and the downstream tip are arranged so that the magnitude relationship between the downstream tip of the work head and the second interval between the second portion is suitable for the viscosity of the coating liquid. Further includes a tip setting step of setting the positional relationship of the above prior to the coating liquid discharge step.

The coating method according to the tenth aspect is the coating method according to the ninth aspect, and the tip setting step is described when the viscosity of the coating liquid is lower than a predetermined reference value. The positional relationship between the upstream tip and the downstream tip is set so that the first spacing related to the upstream tip is wider than the second spacing related to the downstream tip, and the coating is applied. When the viscosity of the working liquid is higher than the reference value, it is a step of setting the positional relationship so that the first interval is wider than the second interval.

According to the invention according to the first aspect, the second coating is performed rather than the distance between the first discharge port of the first coating head and the first portion of one surface of the base material on which the first discharge port faces. The distance between the second discharge port of the head and the second portion of the one surface on which the second discharge port faces is long. Therefore, among the plurality of coating films intermittently formed on one surface of the base material by the first coating head, each of the plurality of regions on one surface sandwiched between the coating films adjacent to each other is the first. When the coating film is formed by the two coating heads, it is possible to prevent the second coating head from coming into contact with the coating film formed by the first coating head. Therefore, when the coating apparatus intermittently coats the coating liquid on the base material to form the coating film, damage to the coating film can be prevented.

According to the invention according to the second aspect, the distance between the upstream tip of the second coating head and the base material is different from the distance between the downstream tip of the second coating head and the base material. Therefore, it is possible to increase the amount of the coating liquid formed between both tips of the second coating head and the base material. As a result, while suppressing air from being entrained in the coating liquid and air bubbles from being mixed into the coating film, the distance between the second coating head and the base material is widened and coating by the second coating head is performed. Damage to the membrane can be prevented more reliably.

According to the invention according to the third aspect, since the upstream tip portion of the second coating head is closer to one surface of the base material than the downstream tip portion, the second coating is performed when the viscosity of the coating liquid is low. It is possible to increase the amount of the coating liquid formed between both tips of the work head and the base material.

According to the invention according to the fourth aspect, since the downstream tip portion of the second coating head is closer to one surface of the base material than the upstream tip portion, the second coating is performed when the viscosity of the coating liquid is high. It is possible to increase the amount of the coating liquid formed between both tips of the work head and the base material.

According to the invention according to the fifth aspect, the second coating is performed rather than the distance between the first discharge port of the first coating head and the first portion of one surface of the base material on which the first discharge port faces. The distance between the second discharge port of the head and the second portion of the one surface on which the second discharge port faces is long. Therefore, among the plurality of coating films intermittently formed on one surface of the base material by the first coating head, each of the plurality of regions on one surface sandwiched between the coating films adjacent to each other is the first. When the coating film is formed by the two coating heads, it is possible to prevent the second coating head from coming into contact with the coating film formed by the first coating head. Therefore, it is possible to prevent damage to the coating film when the coating liquid is intermittently applied onto the base material to form the coating film by the coating method.

According to the invention according to the ninth aspect, the first distance between the upstream tip of the second coating head and the base material, and the second distance between the downstream tip of the second coating head and the base material. The positional relationship between the upstream tip and the downstream tip is set in the tip setting step prior to the coating liquid discharge step so that the magnitude relationship of the above is suitable for the viscosity of the coating liquid. Therefore, since the second coating head whose positional relationship between the upstream tip and the downstream tip is suitable for the viscosity of the coating liquid can be used in the coating liquid discharge process, the second coating head can be used. It is possible to increase the amount of the coating liquid formed between both tips and the base material. As a result, while suppressing air from being entrained in the coating liquid and air bubbles from being mixed into the coating film, the distance between the second coating head and the base material is widened and coating by the second coating head is performed. Damage to the membrane can be prevented more reliably.

According to the invention according to the tenth aspect, in the tip setting step, when the viscosity of the coating liquid is lower than a predetermined reference value, the first interval related to the upstream tip is set to the downstream tip. The positional relationship between the upstream tip and the downstream tip is set so as to be wider than the second interval, and when the viscosity of the coating liquid is higher than the reference value, the first interval is greater than the second interval. Is a process of setting the positional relationship so as to be wider. Therefore, regardless of whether the viscosity of the coating liquid is higher or lower than the reference value, the second coating in which the liquid pool of the coating liquid formed between the second coating head and the base material becomes large. The coating liquid discharge process can be performed using the work head.

It is a figure which shows the whole structure of the coating film forming system which incorporated the coating apparatus which concerns on embodiment of this invention. It is a figure which shows the schematic structure of the coating apparatus of FIG. It is a top view which shows typically the base material on which the coating film was formed by the coating apparatus of FIG. It is a figure for demonstrating the relationship between the distance between a coating head and a base material, and the liquid pool formed between a coating head and a base material. It is a schematic diagram which shows the state which the distance between a coating head and a base material is long, and air is entrained in a coating liquid. FIG. 5 is a schematic plan view illustrating a base material on which a coating film is formed by the coating liquid of FIG. FIG. 5 is a schematic plan view illustrating a base material on which a coating film is formed by the coating liquid of FIG. It is sectional drawing for explaining the structural example of the coating head of the coating apparatus of FIG. It is sectional drawing for explaining the structural example of the coating head of the coating apparatus of FIG. It is sectional drawing for explaining the structural example of the coating head of the coating apparatus of FIG. It is a figure for demonstrating the adjustment of the tip part of the coating head of the coating apparatus of FIG. It is a flowchart which shows an example of the operation of the coating film formation system of FIG. It is a flowchart which shows an example of the adjustment procedure of the tip part of a coating head. It is a figure which shows another example of the whole structure of the coating film forming system which incorporated the coating apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<1. Overall configuration of coating film formation system>
FIG. 1 is a diagram showing an overall configuration of a coating film forming system 1 incorporating the coating apparatus according to the present invention. In addition, in FIG. 1 and each subsequent drawing, the dimensions and numbers of each part are exaggerated or simplified as necessary for easy understanding.

In this coating film forming system 1, a coating liquid 6 containing an active material as an electrode material is coated on a metal foil as a base material, and the coating liquid 6 is dried to perform lithium ion secondary. It is a device that manufactures electrodes for batteries. The coating film forming system 1 includes a coating device 10, a drying portion 150, and a transport mechanism 80. Further, the coating film forming system 1 includes a control unit 90 that manages the entire system.

The base material 5 is a metal foil that functions as a current collector for a lithium ion secondary battery. When the positive electrode of the lithium ion secondary battery is manufactured by the coating film forming system 1, for example, an aluminum foil (Al) can be used as the base material 5. Further, when the negative electrode is manufactured by the coating film forming system 1, for example, copper foil (Cu) can be used as the base material 5. The base material 5 is a long sheet-shaped metal foil, that is, a long strip-shaped member, and the width and thickness thereof are not particularly limited, but are, for example, 600 mm to 700 mm in width and 10 μm to 20 μm in thickness. can do.

The long base material 5 is sent out from the unwinding roller 81 and wound up by the winding roller 82, so that the coating device 10 and the drying portion 150 are conveyed in this order. The transport mechanism 80 includes the unwinding roller 81, the winding roller 82, and a plurality of auxiliary rollers 83. The transport mechanism 80 transports the base material 5 along a predetermined transport path along the longitudinal direction of the base material 5. That is, the transport mechanism 80 transports the base material 5 in the longitudinal direction thereof. The number and arrangement positions of the auxiliary rollers 83 are not limited to the example of FIG. 1, and can be appropriately increased or decreased as necessary.

The drying unit 150 dries the coating film (also referred to as “coating film”) 7 of the coating liquid 6 formed on the base material 5 by the coating device 10. The drying unit 150 heats the base material 5 transported by the transport mechanism 80 to evaporate the solvent from the coating liquid 6 and perform a drying process. The drying portion 150 is, for example, a preheating portion that slowly raises the temperature of the coating film 7 of the coating liquid 6, a main drying portion that raises the coating film 7 to a predetermined temperature and mainly heats the coating film 7, and the coating film 7. It may be provided with an annealing part for removing strain and residual stress in the film by heating the film to a higher temperature, a cooling part for cooling the heated coating film 7.

In this specification, the coating nozzle 11 and the coating nozzle 12 discharge the coating liquid 6 toward the base material 5, respectively, but the coating nozzle 11 and the coating nozzle 12 discharge the coating liquid 6. As a general term for the coating film formed on the base material 5, "coating film 7" may be described. Further, when distinguishing between the coating film formed by the coating nozzle 11 and the coating film formed by the coating nozzle 12, the coating film formed by the coating nozzle 11 is referred to as "coating film 71". The coating film formed by the coating nozzle 12 may be described as "coating film 72".

<2. Coating equipment>
FIG. 2 is a diagram showing a schematic configuration of a coating device 10 according to the present invention. FIG. 3 is a plan view schematically showing the base material 5 on which the coating film 7 is formed by the coating apparatus 10.

The coating device 10 includes a coating nozzle (“first coating head”) 11, a coating nozzle (“second coating head”) 12, and a coating liquid supply mechanism 3 as main elements. The coating liquid supply mechanism 3 includes a storage tank 20, supply pipes 30, 37, 38, and a circulation pipe 40. The coating liquid supply mechanism 3 intermittently supplies the coating liquid 6 to each of the coating nozzle 11 and the coating nozzle 12, so that the coating liquid 6 is based on each of the coating nozzle 11 and the coating nozzle 12. The coating liquid 6 is intermittently discharged toward one surface 5a of the material 5.

The coating apparatus 10 intermittently applies the coating liquid 6 to the base material 5 to perform the intermittent coating of the coating liquid 6. The storage tank 20 stores a solution of an active material, which is an electrode material of a lithium ion secondary battery, as a coating liquid 6. When the positive electrode is manufactured by the coating film forming system 1, the coating liquid 6 of the positive electrode material is, for example, lithium cobalt oxide (LiCoO ₂ ) which is a positive electrode active material, carbon (C) which is a conductive auxiliary agent, and the like. A mixed solution of polyvinylidene fluoride (PVDF) as a coating agent and N-methyl-2-pyrrolidone (NMP) as a solvent is stored. Instead of lithium cobalt oxide, lithium nickel oxide (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ), lithium iron phosphate (LiFePO ₄ ), or the like can also be used as the positive electrode active material.

On the other hand, when the negative electrode is manufactured by the coating film forming system 1, the coating liquid 6 of the negative electrode material is, for example, graphite (graphite) which is a negative electrode active material, PVDF which is a binder, and NMP which is a solvent. The mixed solution is stored in the storage tank 20. Instead of graphite, hard carbon, lithium titanate (Li ₄ Ti ₅ O ₁₂ ), silicon alloy, tin alloy and the like can be used as the negative electrode active material. Further, in both of the positive electrode material and negative electrode material, instead of PVDF as a binder a styrene - can be used such as butadiene rubber (SBR), to use such as water (H 2 _O) in place of NMP as a solvent be able to. Further, when SBR is used as the binder and water is used as the solvent, carboxymethyl cellulose (CMC) can be used in combination as the thickener. The coating liquid 6 of the positive electrode material and the negative electrode material is a slurry in which solids (fine particles) are dispersed, and the viscosity thereof is 1 Pa · s (pascal seconds) or more, and generally has thixotropic property.

The storage tank 20 may be provided with a stirrer, an air pressurizing unit, or the like. The stirrer stirs the coating liquid 6 stored in the storage tank 20 to make the concentration distribution uniform. The air pressurizing unit sends high-pressure air to the gas phase portion in the storage tank 20 to pressurize the liquid level of the stored coating liquid 6.

The coating liquid supply mechanism 3 further includes supply valves 32 and 34. The storage tank 20 and the coating nozzle 11 are communicated with each other by the supply pipes 30 and 37. The storage tank 20 and the coating nozzle 12 are communicated with each other by the supply pipes 30 and 38. The supply pipe 30 is branched into two pipes connected to the supply valves 32 and 34 in the middle of the route, and supplies the coating liquid 6 stored in the storage tank 20 toward the supply valves 32 and 34. The supply pipe 37 supplies the coating liquid 6 from the supply valve 32 toward the coating nozzle 11, and the supply pipe 38 supplies the coating liquid 6 from the supply valve 34 toward the coating nozzle 12. As the supply pipes 30, 37, 38, stainless steel pipes or resin pipes (including flexible pipes, the same applies hereinafter) can be used. A pump 31 is inserted in the middle of the path of the supply pipe 30, and a filter 33 is inserted in the middle of the path of the supply pipe 37. Further, the circulation pipe 40 is provided by branching from the middle of the route of the supply pipe 30. The base end side of the circulation pipe 40 is connected to the supply pipe 30 at a position downstream of the pump 31 (closer to the coating nozzle 11) and upstream of the filter 33, and the tip side is connected to the storage tank 20. ing.

The pump 31 is provided on the upstream side (closer to the storage tank 20) of the connection portion of the circulation pipe 40, is controlled by the control unit 90, and is a coating liquid for the electrode material stored in the storage tank 20. 6 is pumped to the supply pipe 30. The supply valves 32 and 34 are controlled by the control unit 90 to repeatedly open and close each branched flow path of the supply pipe 37. As a result, the supply / stop of the coating liquid 6 to the coating nozzles 11 and 12 is repeatedly switched. Specifically, the supply valve 32 intermittently discharges the coating liquid 6 from the coating nozzle 11 toward one surface 5a of the base material 5 by repeatedly switching the opening and closing of the supply pipe 37. The supply valve 34 intermittently discharges the coating liquid 6 from the coating nozzle 12 toward one surface 5a of the base material 5 by repeatedly switching the opening and closing of the supply pipe 38. The filter 33 is inserted in the path of the supply pipe 37 at a portion between the portion where the supply pipe 37 branches toward the supply valves 32 and 34 and the connection portion between the supply pipe 37 and the circulation pipe 40, and is inserted into the supply pipe. Foreign matter is removed from the coating liquid 6 flowing toward the coating nozzles 11 and 12.

The coating nozzle 11 (12) is a slit nozzle (“slit die”) provided with slit-shaped discharge ports 11a and 12a along the width direction of the base material 5. The discharge ports 11a and 12a extend along one surface 5a of the base material 5 in a direction orthogonal to the longitudinal direction of the base material 5 and face the one surface 5a. The coating nozzle 11 (12) is the surface of the base material 5 that travels in a state where the coating liquid 6 supplied via the supply pipes 30 and 37 (38) is pressed and supported by the backup roller 13 (14). The coating is applied from the discharge port 11a (12a).

The coating nozzles 11 (12) are arranged on one side 5a side of the base material 5, respectively. The coating nozzle 12 is arranged on the downstream side of the coating nozzle 11 in the transport direction of the base material 5 by the transport mechanism 80.

Further, the discharge port ("first discharge port") 11a of the coating nozzle 11 and the discharge port ("first discharge port") 11a of the coating nozzle 12 are closer than the distance D1 between the first portion P1 of the one surface 5a where the discharge port 11a faces. The distance D2 between the “second discharge port”) 12a and the second portion P2 of the one surface 5a on which the discharge port 12a faces is long. Further, the interval D2 is larger than the film thickness dimension of the coating film 71 passing facing the coating nozzle 12.

The tip end side of the circulation pipe 40 branched from the middle of the route of the supply pipe 30 is connected to the storage tank 20. Similar to the supply pipes 30, 37, 38, a stainless steel pipe or a resin pipe can be used as the circulation pipe 40. The circulation pipe 40 returns the coating liquid 6 sent from the storage tank 20 and flowing from the supply pipe 37 to the storage tank 20. A circulation valve 41 and a filter 43 are inserted in the circulation pipe 40. The circulation valve 41 is controlled by the control unit 90 to open and close the flow path of the circulation pipe 40. The filter 43 is provided between the circulation valve 41 and the storage tank 20, and removes foreign matter from the coating liquid 6 flowing toward the storage tank 20 through the circulation pipe 40.

When the supply valve 32 (34) is opened while closing the circulation valve 41, the coating liquid 6 sent from the storage tank 20 flows over the entire supply pipes 30, 37 (38) and reaches the coating nozzle 11 (12). Is supplied.

On the other hand, when the circulation valve 41 is opened while closing the supply valve 32 (34), the coating liquid 6 sent out from the storage tank 20 flows to the middle of the supply pipe 30 and flows into the circulation pipe 40, and is again stored in the storage tank 20. Is refluxed to. That is, the supply valve 32 (34) is coated by repeatedly switching the sending / stopping of the coating liquid 6 supplied from the storage tank 20 to the coating nozzle 11 (12) via the supply pipe 37. It functions as a switching means for intermittently discharging the liquid 6 from the coating nozzle 11 (12).

The timing of opening and closing of the supply valves 32 and 34 and the circulation valve 41 is appropriately controlled by the control unit 90, and by repeatedly switching the opening and closing, the coating liquid 6 is intermittently applied to a predetermined position of the base material 5 with a predetermined width. Will be done. The control unit 90 is a plurality of coating films 71 intermittently formed on one surface 5a of the base material 5 by the coating nozzle 11 and sandwiched between coating films 71 adjacent to each other on one surface 5a. The coating liquid supply mechanism 3 is controlled so that the coating film 72 is formed by the coating nozzle 12 in each of the regions. More specifically, the coating device 10 further includes a photo sensor 36 that detects the front end or the rear end of the coating film 71 in the transport direction of the base material 5. The photo sensor 36 is electrically connected to the control unit 90, and the detection signal of the photo sensor 36 is supplied to the control unit 90. The control unit 90 detects the front end or the rear end of the coating film 71 formed on the base material 5 by the coating nozzle 11 based on the detection signal. The control unit 90 opens and closes the supply valves 32 and 34 based on the detected timing, the distance between the coating nozzle 11 and the coating nozzle 12 in the transport path of the base material 5, the transport speed of the base material 5, and the like. The timing is controlled so that the coating liquid 6 is discharged from the coating nozzle 12 to the region on one surface 5a sandwiched between the adjacent coating films 71.

At this time, the distance D2 between the coating nozzle 12 and the one surface 5a is longer than the distance D1 between the coating nozzle 11 and the one surface 5a, and the distance D2 is the coating that passes toward the coating nozzle 12. It is larger than the film thickness dimension of the work film 71. As a result, the coating nozzle 12 is prevented from coming into contact with the coating film 71, and damage to the coating film 71 can be prevented.

As a result, as shown in FIG. 3, the coating film 71 formed by the coating nozzle 11 and the coating film 72 formed by the coating nozzle 12 are formed on one surface 5a of the base material 5. The materials 5 are arranged alternately along the transport direction. The coating film 71 and the coating film 72 are alternately arranged at substantially equal intervals. The distance between adjacent coating films 71 (72) can be widened as compared with the case where intermittent coating is performed only by the coating nozzle 11. Therefore, since the response time required for the supply valves 32 and 34 can be spared, the uncoated length U1 shown in FIG. 3 can be shortened. As a result, the wasted base material 5 can be reduced. In other words, for example, when the intermittent coating is executed only by the coating nozzle 11, the uncoated length becomes longer than the uncoated length U1 due to the response time of the supply valve 32. If the uncoated length becomes long, the amount of the base material 5 that is wasted in the production of the lithium ion secondary battery increases.

Further, in the example of FIG. 2, a pressure gauge 35 is attached. The pressure gauge 35 is provided in the supply pipe 30 at a position between the connection portion with the circulation pipe 40 and the pump 31, for example. The measured value measured by the pressure gauge 35 is output to the control unit 90. The control unit 90 can control the driving speed (rotational speed) of the pump 31 so that the pressure becomes a desired value, for example.

In the coating apparatus, as described above, by controlling the opening and closing of the supply valve 32 (34) provided at the base end of the supply pipe 37, the coating nozzle 11 (12) provided at the tip of the supply pipe 37 can be used. Controls the intermittent coating of the coating liquid 6.

<3. About the distance between the coating head and the base material and the state of the coating liquid 6>
FIG. 4 takes the coating nozzle 12 as an example to explain the relationship between the distance between the coating nozzle 12 and the base material 5 and the liquid pool formed between the coating nozzle 12 and the base material 5. It is a figure. This relationship also applies to the coating liquid 6 discharged by the coating nozzle 11.

FIG. 4 shows a case where the distance between the upstream tip portion 121 of the coating nozzle 12 and one surface 5a of the base material 5 is equal to the distance between the upstream tip portion 121 and one surface 5a.

As shown in FIG. 3, when the coating film 7 is alternately formed on the base material 5 by the coating nozzle 11 and the coating nozzle 12, the thickness of the coating film 71 formed by the coating nozzle 12 is increased. However, when the distance D2 between the coating nozzle 12 and the base material 5 is narrow, the coating nozzle 12 collides with the coating film 71.

Therefore, as described above, the coating device 10 has a coating nozzle 12 rather than a distance D1 between the discharge port 11a of the coating nozzle 11 and the first portion P1 of the one surface 5a on which the discharge port 11a faces. The distance D2 between the discharge port 12a and the second portion P2 of the one surface 5a on which the discharge port 12a faces is set long (see FIG. 2).

In the following, the effect of increasing the interval D2 will be described.

In FIG. 4, a coating nozzle 12 in which the distance between the upstream tip portion 121 and the downstream tip portion 122 and one surface 5a is set to the interval H1 is shown by a solid line, and is discharged from the coating nozzle 12. The outline of the coating liquid 6 is shown by a solid line. Further, the coating nozzle 12 whose interval is set to the interval H2 larger than the interval H1 is indicated by a chain line, and the outline of the coating liquid 6 discharged from the coating nozzle 12 is shown by a broken line. Is shown.

For example, if the viscosity of the coating liquid 6 is 4000 cp and the film thickness of the coating film 7 immediately after being discharged to the base material 5 and before drying is 100 um, the distance between the coating nozzle and the base material 5 (“coating”). The gap) is set to, for example, about 70 μm to 130 μm.

In this case, for example, assuming that the interval H1 is 70 μm and the interval H2 is 130 μm, when the interval H1 fluctuates to the interval H2, the meniscus of the coating liquid 6 on the upstream side in the transport direction is as shown in FIG. , Moves upward (downstream side), and the meniscus on the downstream side moves downward (upstream side).

FIG. 5 is a schematic view showing a state in which the distance H3 between the coating head and the base material 5 is longer than the distance H2 in FIG. 4 and air is entrained in the coating liquid 6. When the interval H2 becomes the interval H3, the meniscus on the upstream side of the coating liquid 6 discharged to the base material 5 moves further upward (downstream side) from the state shown by the broken line in FIG. 4, and is on the upstream side. It reaches the downstream end of the tip surface of the tip 121 facing the base material 5. In this state, air is entrained in the coating liquid 6 from the upstream side in the transport direction with respect to the coating liquid 6 and enters the coating liquid 6, and a large number of bubbles 201 are generated in the coating liquid 6. Further, a large number of bubbles 201 enter the coating liquid 6 from the upstream side, so that the coating liquid 6 is pushed out to the downstream side, and the pushed out coating liquid 601 is located on the downstream side of the downstream tip portion 122. Reach the side.

6 and 7 are schematic plan views illustrating the base material 5 on which the coating film 7 is formed by the coating liquid 6 of FIG. As shown in FIG. 5, when air is entrained in the coating liquid 6 from the upstream side and a large number of bubbles 201 are formed in the coating liquid 6, they are formed on the base material 5 as shown in FIG. The coating film 7 contains a large number of bubbles 201, and the coating film 7 does not satisfy the required quality.

Further, as shown in FIG. 5, when the coating liquid 601 extruded into the bubbles 201 reaches the downstream side surface of the downstream tip portion 122, the coating liquid 6 is applied as shown in FIG. By being pulled by the working liquid 601, a streak 202 extending in the transport direction is formed on the surface of the formed coating film 7. As a result, the coating film 7 does not meet the required quality.

<4. Coating head configuration example>
8 to 10 are schematic cross-sectional views for explaining a configuration example of the coating nozzle 12 of the coating apparatus 10, respectively.

The coating nozzle 12 may adopt each of the configurations exemplified in FIGS. 8 to 10 in order to suppress the problem caused by the entrainment of air in the coating liquid 6 described above.

The coating nozzle 12 shown in FIGS. 8 and 9 includes an upstream tip portion 121 and a downstream tip portion 122 in the transport direction that define the discharge port 12a. The distance D2F between the upstream tip portion 121 and the second portion P2 on one surface 5a of the base material 5 and the distance D2R between the downstream tip portion 122 and the second portion P2 are different.

In the example of FIG. 8, the upstream tip portion 121 of the coating nozzle 12 is closer to one surface 5a of the base material 5 than the downstream tip portion 122.

On the contrary, in the example of FIG. 9, the downstream tip portion 122 of the coating nozzle 12 is closer to one surface 5a of the base material 5 than the upstream tip portion 121.

In the example of FIG. 10, the interval D2F and the interval D2R are equal to each other, as in the examples of FIGS. 4 and 5. Depending on the coating conditions, even if the configuration shown in FIG. 10 is used, the tip of the coating nozzle 12 does not collide with the coating film 71 formed by the coating nozzle 11, and FIGS. 5 and 6 show. The problems shown may not occur. Therefore, the configuration of FIG. 10 may be adopted as the coating nozzle 12.

In FIGS. 8 to 10, the distance D2 between the coating nozzle 12 and the base material 5 is the same. The interval D2 is the shortest interval between the tip of the upstream tip 121 and the base material 5 (second part P2) and the distance between the tip of the downstream tip 122 and the base 5 (second part P2). Is.

As shown in FIGS. 8 and 9, when the interval D2F and the interval D2R are different, the pressure loss in the coating nozzle 12 differs between the upstream side and the downstream side of the discharge port 12a, and is shown in FIG. Compared to the liquid pool 63 of the coating liquid 6 shown, the liquid pool 61 and the liquid pool 62 in FIGS. 8 and 9 are larger. As a result, even if the interval D2 is further lengthened from the state of FIGS. 8 and 9, it is possible to suppress the entrainment of air into the coating liquid 6 from the upstream side in the transport direction of the base material 5.

In the example of FIG. 8, since the interval D2F is shorter than the interval D2R, the pressure loss in the coating nozzle 12 is small on the upstream side and large on the downstream side of the discharge port 12a. Therefore, the liquid pool 61 becomes large on the downstream side. The configuration shown in FIG. 8 is preferably applied to the coating liquid 6 having a low viscosity. When the viscosity is low, the coating liquid 6 discharged to the base material 5 is less likely to be pulled downstream as the base material 5 moves, so that the liquid pool 61 can be increased as compared with the case where the viscosity is high.

In the example of FIG. 9, since the interval D2F is longer than the interval D2R, the pressure loss in the coating nozzle 12 is large on the upstream side and small on the downstream side of the discharge port 12a. Therefore, the liquid pool 62 becomes large on the downstream side. The configuration shown in FIG. 9 is preferably applied to the coating liquid 6 having a high viscosity. When the viscosity is high, the formed liquid pool 62 is less likely to flow out to the upstream side (downward) than when the viscosity is low, so that the liquid pool 62 can be increased.

<5. Operation of coating film forming system>
FIG. 11 is a diagram for explaining the adjustment of the tip portion (upstream side tip portion 121, downstream side tip portion 122) of the coating nozzle 12 of the coating device 10. 12 and 13 are flowcharts showing an example of the operation of the coating film forming system 1 (coating apparatus 10).

The operation of the coating film forming system 1 (coating apparatus 10) will be described below with reference to the drawings such as FIG. 11 based on the flowcharts of FIGS. 12 and 13.

In step S10 of FIG. 12, the positional relationship (tip setting step) of both tip portions (upstream side tip portion 121, downstream side tip portion 122) of the coating nozzle 12 is adjusted.

When the process of step S10 is started, in step S110 of FIG. 13, for example, the operator determines whether or not the viscosity of the coating liquid 6 is lower than a predetermined reference value.

As a result of the determination in step S110, when the viscosity of the coating liquid 6 is lower than the reference value, the operator in step S120, as shown in FIG. 8, the upstream tip portion 121 of the coating nozzle 12. Attaches a coating nozzle 12 having a “front protruding shape” closer to one surface 5a of the base material 5 (projecting toward the one surface 5a side) than the downstream tip portion 122 to the coating device 10.

For example, as shown in FIG. 11, the coating nozzle 12 has an upstream tip portion 121 and an upstream tip portion 121 installed on a base 199, and the base end of the upstream tip portion 121 and a base. With the spacer 198 inserted between the spacer 198 and the spacer 198, the upstream tip portion 121 and the downstream tip portion 122 are fixed by screwing or the like so that the discharge port 12a is formed. The height of the spacer 198 is set so that a step of a desired length is formed between the tips of the upstream tip 121 and the downstream tip 122, respectively.

As a result of the determination in step S110, if the viscosity of the coating liquid 6 is equal to or higher than the reference value, the process of step S130 is performed.

In step S130, as shown in FIG. 9, the operator applies a “rear protruding shape” in which the downstream tip portion 122 of the coating nozzle 12 is closer to the one surface 5a of the base material 5 than the upstream tip portion 121. The work nozzle 12 is attached to the coating device 10. When the coating nozzle 12 is adjusted to have a “rear protruding shape”, the spacer 198 is inserted below the downstream tip portion 122 in the adjustment shown in FIG.

Instead of performing steps S110 to S130, the operator includes a coating nozzle 12 having a "front protruding shape" and a coating nozzle 12 having a "rear protruding shape", respectively, in which the coating device 10 is adjusted in advance. , These coating nozzles 12 may be moved and attached to the coating apparatus 10 by a predetermined replacement mechanism.

The process of step S10 includes the first interval D2F between the upstream tip portion 121 of the coating nozzle 12 and the second portion P2 of the one surface 5a of the base material 5, and the downstream tip portions 122 and the second portion of the coating nozzle 12. The positional relationship between the upstream tip portion 121 and the downstream tip portion 122 is set so that the magnitude relationship with the second interval D2R with the portion P2 is suitable for the viscosity of the coating liquid 6, and the coating liquid 6 is discharged. This is a process that is set prior to the process.

Specifically, in this treatment, for example, when the viscosity of the coating liquid 6 is lower than a predetermined reference value, the first interval D2F related to the upstream tip portion 121 is the first interval D2F related to the downstream tip portion 122. The positional relationship between the upstream tip 121 and the downstream tip 122 is set so as to be wider than the two intervals D2R, and when the viscosity of the coating liquid 6 is higher than the reference value, the first interval D2F is the first. This is a process of setting the positional relationship so as to be wider than the two intervals D2R.

When the process of step S120 or step S130 is completed, the process of step S20 of FIG. 12 is performed.

In step S20, the coating film forming system 1 (coating apparatus 10) starts transporting the base material 5. The coating film forming system 1 drives the transport mechanism 80 to move the base material 5 in a predetermined transport direction along a predetermined transport path.

In step S30, the coating device 10 forms the coating film 7 (coating film 71, coating film 72) on the base material 5. As described above, the control unit 90 controls the opening and closing of the supply valves 32 and 34 based on the output signal of the photo sensor 36. The transport speed of the base material 5 is set to, for example, 60 m / sec to 100 m / sec, and the uncoated length U1 between the coating film 71 and the coating film 72 is set to, for example, about 10 mm to 20 mm. To. The coating device 10 forms a predetermined number of coating films 7 on the base material 5.

In step S40, the coating film forming system 1 dries the base material 5 (coating film 7 of the base material 5) on which the coating film 7 is formed by the transport mechanism 80 in the drying portion.

In step S50, the coating film forming system 1 stops the transport mechanism 80, finishes the transport of the base material 5, and ends the operation of FIG.

<6. Other Configuration Examples of Coating Film Formation System>
FIG. 14 is a diagram showing another example of the overall configuration of the coating film forming system 1 incorporating the coating apparatus 10 according to the embodiment. In the coating film forming system 1 of FIG. 1, the coating nozzle 12 forms the coating film 72 in the middle of the conveying path moving upward from the upstream side to the downstream side in the conveying direction of the base material 5. It was. However, as shown in FIG. 14, a configuration may be adopted in which the coating film 72 formed by the coating nozzle 12 is conveyed to the drying portion 150 side along a substantially horizontal path.

According to the coating apparatus according to the present embodiment configured as described above, the discharge port 11a of the coating nozzle 11 and the first portion P1 of the one surface 5a of the base material 5 facing the discharge port 11a. The distance D2 between the discharge port 12a of the coating nozzle 12 and the second portion P2 of the one surface 5a on which the discharge port 12a faces is longer than the distance D1. Therefore, among the plurality of coating films 71 intermittently formed on the one surface 5a of the base material 5 by the coating nozzle 11, the plurality of regions on the one surface 5a sandwiched between the coating films 71 adjacent to each other. When the coating film 72 is formed by the coating nozzle 12, it is possible to prevent the coating nozzle 12 from coming into contact with the coating film 71 formed by the coating nozzle 11. Therefore, when the coating apparatus intermittently coats the coating liquid 6 on the base material 5 to form the coating film 7, damage to the coating film 7 can be prevented.

Further, according to the coating apparatus according to the present embodiment, the distance D2F between the upstream tip portion 121 of the coating nozzle 12 and the base material 5 and the downstream tip portion 122 of the coating nozzle 12 and the base material 5 are provided. The interval D2R is different. Therefore, it is possible to increase the amount of the coating liquid 6 formed between both tips of the coating nozzle 12 and the base material 5. As a result, while suppressing air from being entrained in the coating liquid 6 and air bubbles from being mixed into the coating film 72, the distance D2 between the coating nozzle 12 and the base material 5 is made wider by the coating nozzle 12. Damage to the coating film 71 can be prevented more reliably.

Further, according to the coating apparatus according to the present embodiment, since the upstream tip portion 121 of the coating nozzle 12 is closer to one surface 5a of the base material 5 than the downstream tip portion 122, the viscosity of the coating liquid 6 is high. When it is low, the liquid pool of the coating liquid 6 formed between both tip portions of the coating nozzle 12 and the base material 5 can be increased.

Further, according to the coating apparatus according to the present embodiment, the downstream tip portion 122 of the coating nozzle 12 is closer to one surface 5a of the base material 5 than the upstream tip portion 121, so that the viscosity of the coating liquid 6 is high. When it is high, the liquid pool of the coating liquid 6 formed between both tip portions of the coating nozzle 12 and the base material 5 can be increased.

Further, according to the coating method according to the present embodiment as described above, the distance between the discharge port 11a of the coating nozzle 11 and the first portion P1 of the one surface 5a of the base material 5 on which the discharge port 11a faces. The distance D2 between the discharge port 12a of the coating nozzle 12 and the second portion P2 of the one surface 5a on which the discharge port 12a faces is longer than that of D1. Therefore, among the plurality of coating films 71 intermittently formed on the one surface 5a of the base material 5 by the coating nozzle 11, the plurality of regions on the one surface 5a sandwiched between the coating films 71 adjacent to each other. When the coating film 72 is formed by the coating nozzle 12, it is possible to prevent the coating nozzle 12 from coming into contact with the coating film 71 formed by the coating nozzle 11. Therefore, when the coating liquid 6 is intermittently applied onto the base material 5 to form the coating film 7 by the coating method, damage to the coating film 7 can be prevented.

Further, according to the coating method according to the present embodiment, the first distance D2F between the upstream tip portion 121 of the coating nozzle 12 and the base material 5 and the downstream tip portion 122 and the base material 5 of the coating nozzle 12 The positional relationship between the upstream tip portion 121 and the downstream tip portion 122 is prior to the coating liquid discharge process so that the magnitude relationship with the second interval D2R is suitable for the viscosity of the coating liquid 6. It is set in the tip setting process. Therefore, the coating nozzle 12 whose positional relationship between the upstream tip portion 121 and the downstream tip portion 122 is suitable for the viscosity of the coating liquid 6 can be used in the coating liquid discharge process, so that the coating nozzle 12 can be used. It is possible to increase the liquid pool of the coating liquid 6 formed between both tip portions and the base material 5. As a result, while suppressing air from being entrained in the coating liquid 6 and air bubbles from being mixed into the coating film 72, the distance D2 between the coating nozzle 12 and the base material 5 is made wider by the coating nozzle 12. Damage to the coating film 71 can be prevented more reliably.

Further, according to the coating method according to the present embodiment, in the tip setting step, when the viscosity of the coating liquid 6 is lower than a predetermined reference value, the first interval D2F related to the upstream tip 121 is set. , When the positional relationship between the upstream tip portion 121 and the downstream tip portion 122 is set so as to be wider than the second interval D2R related to the downstream tip portion 122, and the viscosity of the coating liquid 6 is higher than the reference value. Is a step of setting the positional relationship so that the first interval D2F is wider than the second interval D2R. Therefore, regardless of whether the viscosity of the coating liquid 6 is higher or lower than the reference value, the liquid pool of the coating liquid 6 formed between the coating nozzle 12 and the base material 5 becomes large. The coating liquid discharge process can be performed using the work nozzle 12.

Although the present invention has been shown and described in detail, the above description is exemplary and not limiting in all embodiments. Therefore, in the present invention, the embodiments can be appropriately modified or omitted within the scope of the invention.

1 Coating film forming system 10 Coating device 11 Coating nozzle (1st coating head)
12 Coating nozzle (2nd coating head)
111,121 Upstream tip 112, 122 Downstream tip 11a Discharge port (first discharge port)
12a Discharge port (second discharge port)
3 Coating liquid supply mechanism 37 Supply pipe 31 Pump 32,34 Supply valve 30, 37, 38 Supply pipe 5 Base material 80 Conveyance mechanism (conveyance part)
90 Control unit D1, D2 interval D2F interval (first interval)
D2R interval (second interval)

Claims (10)

It is a coating device that intermittently coats a long strip-shaped base material.
A transport unit that transports the base material in the longitudinal direction,
A first coating head arranged on one surface side of the base material and having a slit-shaped first discharge port extending along the one surface in a direction orthogonal to the longitudinal direction and facing the one surface.
It is arranged on the one side of the first coating head on the downstream side in the transport direction of the base material by the transport portion, extends along the one surface in a direction orthogonal to the longitudinal direction, and extends to the one surface. A second coating head having a slit-shaped second discharge port facing each other,
By intermittently supplying the coating liquid to each of the first coating head and the second coating head, the base is provided from each of the first coating head and the second coating head. A coating liquid supply mechanism that intermittently discharges the coating liquid toward the one side of the material,
Of the plurality of coating films intermittently formed on the one surface of the base material by the first coating head, each of the plurality of regions on the one surface sandwiched between the coating films adjacent to each other. , A control unit that controls the coating liquid supply mechanism so that the coating film is formed by the second coating head.
With
The second discharge port of the second coating head and the one said, rather than the distance between the first discharge port of the first coating head and the first portion of the one surface on which the first discharge port faces. A coating device having a long distance from a second portion of the direction facing which the second discharge port faces. The coating device according to claim 1.
The second coating head includes an upstream-side tip portion and a downstream-side tip portion in the transport direction that define the second discharge port.
A coating device in which the distance between the upstream tip portion and the second portion of the one surface of the base material and the distance between the downstream tip portion and the second portion are different. The coating device according to claim 2.
A coating device in which the upstream end portion of the second coating head is closer to the one surface of the base material than the downstream end portion. The coating device according to claim 2.
A coating device in which the downstream end portion of the second coating head is closer to the one surface of the base material than the upstream end portion. It is a coating method that intermittently coats a long strip-shaped base material.
A transport process for transporting the base material in the longitudinal direction and
A first coating head which is arranged on one surface side of the base material and has a slit-shaped first discharge port which extends in a direction orthogonal to the longitudinal direction along the one surface and faces the one surface, and the said. It is arranged on the one side of the base material downstream of the first coating head in the transport direction of the base material, extends along the one surface in a direction orthogonal to the longitudinal direction, and faces the one surface. Coating liquid discharge that intermittently discharges the coating liquid from each of the second coating head having the slit-shaped second discharge port toward the one surface of the base material in parallel with the transfer process. Process and
With
The coating liquid discharge process is
Of the plurality of coating films intermittently formed on the one surface of the base material by the first coating head, each of the plurality of regions on the one surface sandwiched between the coating films adjacent to each other. , A step of discharging the coating liquid from each of the first coating head and the second coating head so that the coating film is formed by the second coating head.
The second discharge port of the second coating head and the one said, rather than the distance between the first discharge port of the first coating head and the first portion of the one surface on which the first discharge port faces. A coating method in which the distance between the direction and the second portion facing the second discharge port is long. The coating method according to claim 5.
The second coating head includes an upstream-side tip portion and a downstream-side tip portion in the transport direction that define the second discharge port.
A coating method in which the distance between the upstream tip portion and the second portion of the one surface of the base material and the distance between the downstream tip portion and the second portion are different. The coating method according to claim 6.
A coating method in which the upstream end portion of the second coating head is closer to the one surface of the base material than the downstream end portion. The coating method according to claim 6.
A coating method in which the downstream end portion of the second coating head is closer to the one surface of the base material than the upstream end portion. The coating method according to claim 5.
The second coating head includes an upstream-side tip portion and a downstream-side tip portion in the transport direction that define the second discharge port.
The coating method is
The first distance between the upstream tip portion of the second coating head and the second portion of the one surface of the base material, and the downstream tip portion and the second portion of the second coating head. Prior to the coating liquid discharge step, the positional relationship between the upstream tip portion and the downstream tip portion is set so that the magnitude relationship with the second interval of the above is suitable for the viscosity of the coating liquid. Tip setting process to set,
A coating method that further prepares. The coating method according to claim 9.
The tip setting step is
When the viscosity of the coating liquid is lower than a predetermined reference value, the upstream portion so that the first interval related to the upstream tip portion becomes wider than the second interval related to the downstream tip portion. The positional relationship between the side tip and the downstream tip is set, and when the viscosity of the coating liquid is higher than the reference value, the first interval is wider than the second interval. A coating method that is a process of setting the positional relationship.

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