Drying device

Abstract

To provide a technique for more suitably preventing explosion caused by a solvent evaporating from a resin film.SOLUTION: A drying device dries a solvent on a resin film. The drying device comprises a housing, a partition wall disposed in the housing to divide the space in the housing into a first space and a second space, a conveyer conveying the resin film in the first space, a first heater disposed in the second space to irradiate the resin film conveyed by the conveyer with electromagnetic waves, and a window that is disposed in the partition wall and can transmit electromagnetic waves radiated from the first heater. The first heater is configured to irradiate the resin film with electromagnetic waves in a wavelength band of below 4.0 μm and to absorb electromagnetic waves in a wavelength band of 4.0 μm or above.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a drying device. [Background technology]

[0002] For example, when manufacturing a resin film used for a separator of a lithium-ion battery, a solvent may be applied to the surface of the resin film. In this case, it is necessary to dry the solvent on the resin film. For example, Patent Document 1 discloses a drying device for drying the solvent on the resin film. The drying device in Patent Document 1 includes a conveying device for conveying the resin film and a heater for irradiating the resin film being conveyed by the conveying device with far-infrared rays.

[0003] When a solvent on a resin film is dried using far-infrared rays emitted from a heater, the heat from the heater can cause the vicinity of the resin film to become hot. When an organic solvent is used as the solvent on the resin film, if the vicinity of the resin film becomes hot, there is a risk of the solvent evaporating from the resin film causing an explosion. In the drying device of Patent Document 1, to prevent an explosion due to evaporated solvent, an insulating layer is provided between the heating layer where the heater is installed and the area (explosion-proof layer) where the resin film is transported. Air flows through the insulating layer, and by ventilating the insulating layer, the temperature inside the insulating layer is prevented from becoming too high. Furthermore, a window that is permeable to far-infrared rays is provided between the insulating layer and the explosion-proof layer, allowing the far-infrared rays emitted from the heater to reach the resin film through the insulating layer. By providing the insulating layer between the heating layer and the explosion-proof layer, the temperature inside the explosion-proof layer where the resin film is transported is prevented from becoming too high while the far-infrared rays emitted from the heater are irradiated onto the resin film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-154585 Summary of the Invention [Problem to be solved by the invention]

[0005] In the drying device of Patent Document 1, a heat insulating layer is provided between the heating layer and the explosion-proof layer. However, when the drying device is continuously operated, the temperature inside the heat insulating layer gradually rises due to far infrared rays emitted from the heater, and the window installed between the heat insulating layer and the explosion-proof layer may also rise to a high temperature. If the window becomes too hot, there is a risk that the temperature inside the explosion-proof layer will also rise through the window.

[0006] This specification discloses a technique for more suitably preventing explosions caused by solvents evaporating from resin films. [Means for solving the problem]

[0007] In a first aspect of the technology disclosed herein, a drying device dries a solvent on a resin film. The drying device includes a housing, a partition wall disposed within the housing to separate the space within the housing into a first space and a second space, a conveying device for conveying the resin film within the first space, a first heater disposed within the second space to irradiate electromagnetic waves onto the resin film conveyed by the conveying device, and a window disposed in the partition wall that is transparent to the electromagnetic waves irradiated from the first heater. The first heater is configured to irradiate the resin film with electromagnetic waves in a wavelength band less than 4.0 μm and to absorb electromagnetic waves in a wavelength band of 4.0 μm or more.

[0008] In the drying device described above, the first heater is configured to irradiate the resin film with electromagnetic waves in a wavelength band of less than 4.0 μm, while absorbing electromagnetic waves in a wavelength band of 4.0 μm or more. By absorbing electromagnetic waves in a wavelength band of 4.0 μm or more, the inside of the housing (i.e., the first space and the second space) is less likely to become hot due to the electromagnetic waves irradiated from the first heater, and the vicinity of the resin film is prevented from becoming hot. This makes it possible to prevent the solvent evaporating from the resin film from becoming hot, and prevents an explosion caused by the solvent evaporating from the resin film. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a drying device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of a heater. [Figure 3] FIG. 4 is a partial enlarged view for explaining the configuration of a window. [Figure 4] FIG. 10 is a diagram showing a schematic configuration of a drying device according to a second embodiment. [Figure 5] FIG. 10 is a diagram showing a schematic configuration of a drying device according to a third embodiment. [Figure 6] FIG. 10 is a diagram showing a schematic configuration of a drying device according to a fourth embodiment. [Figure 7] FIG. 3 is a perspective view showing a tubular member, a heater, and a resin film. [Figure 8] FIG. 10 is a diagram showing a schematic configuration of another example of a drying device according to the fourth embodiment.

[0010] The main features of the embodiments described below are listed below. Note that the technical elements described below are independent technical elements that exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

[0011] In a second aspect of the technology disclosed in this specification, in the first aspect described above, the first heater may be configured to irradiate the resin film with electromagnetic waves in a wavelength band of 3.5 μm or less and to absorb electromagnetic waves in a wavelength band of 3.5 μm or more.

[0012] In a third aspect of the technology disclosed in this specification, in the first or second aspect described above, the first heater may include a heating element extending in a direction perpendicular to the conveying direction of the resin film, a first tube disposed on the outer periphery of the heating element and surrounding the heating element, and a second tube disposed on the outer periphery of the first tube and surrounding the second tube. The first tube and the second tube may be formed of a material that absorbs electromagnetic waves in a wavelength band of 4.0 μm or more. With this configuration, the first heater can effectively radiate only electromagnetic waves in a wavelength band of less than 4.0 μm, while hardly radiating electromagnetic waves in a wavelength band of 4.0 μm or more.

[0013] In a fourth aspect of the technology disclosed in this specification, in any one of the first to third aspects, the first heater may irradiate the resin film with electromagnetic waves containing 80% or more of infrared energy in a wavelength band of less than 4.0 μm. With this configuration, the resin film can be suitably irradiated with electromagnetic waves in a wavelength band of less than 4.0 μm.

[0014] In a fifth aspect of the technique disclosed in this specification, in any one of the first to fourth aspects, the first heater may irradiate the resin film with electromagnetic waves including visible light and ultraviolet light.

[0015] In a sixth aspect of the technology disclosed in the present specification, in any one of the first to fifth aspects, the window may include a support frame provided on the partition wall and a transmissive body supported by the support frame and capable of transmitting electromagnetic waves irradiated from the first heater. A sealing member may be used to seal the gap between the support frame and the transmissive body. With this configuration, the sealing member seals the gap between the support frame and the transmissive body, thereby preventing the solvent evaporated from the resin film from migrating to the vicinity of the heater. Although the surface of the first heater is unlikely to become hot, if the first heater is operated for a long period of time, the temperature around the first heater becomes higher than that around the resin film. By preventing the solvent evaporated from the resin film from migrating to the vicinity of the first heater, an explosion within the drying device can be prevented.

[0016] In a seventh aspect of the technology disclosed in this specification, in any one of the first to sixth aspects, the drying device may further include an air supply device that supplies atmospheric gas to at least one of the first space and the second space, and an exhaust device that exhausts the atmospheric gas from at least one of the first space and the second space. The air supply device and the exhaust device may create a negative pressure in the first space relative to the second space. With this configuration, creating a negative pressure in the first space relative to the second space makes it difficult for gas to move from the first space to the second space. Therefore, it is possible to prevent solvent evaporated from the resin film being transported through the first space from moving near the first heater installed in the second space.

[0017] In an eighth aspect of the technology disclosed herein, in any one of the first to seventh aspects, the drying device may further include an air intake port that opens into the second space and blows gas toward the window. Because the surface of the window facing the second space continues to be directly irradiated with electromagnetic waves from the first heater, there is a risk that the surface of the window facing the second space will become hot. By blowing gas toward the surface of the window facing the second space, the surface temperature of the window can be lowered, and the first space on the resin film side can be prevented from becoming hot through the window due to the high temperature of the window.

[0018] In a ninth aspect of the technology disclosed in this specification, in any one of the first to eighth aspects, the drying device may further include an exhaust port provided on the lower surface of the housing, for exhausting atmospheric gas in the first space from below the housing. With this configuration, the gas in the first space can be exhausted from below. Solvent on the resin film is often heavier than air when evaporated. By exhausting the gas in the first space from below, it becomes easier to exhaust the solvent evaporated from the resin film from inside the housing.

[0019] In a tenth aspect of the technology disclosed in this specification, in any one of the first to eighth aspects, the drying device may further include a tubular member extending in the transport direction and configured to transport the resin film therethrough. The partition walls may be on the upper and lower surfaces of the tubular member. A window may be disposed on at least one of the upper and lower surfaces. The first heater may be disposed near one of the upper and lower surfaces so as to irradiate electromagnetic waves toward the window disposed on one of the upper and lower surfaces. Even with this configuration, gas movement between the first space and the second space can be prevented, and the solvent evaporated from the resin film can be inhibited from moving near the heater.

[0020] In an eleventh aspect of the technology disclosed herein, in the tenth aspect described above, a window may be further installed on the other of the upper and lower surfaces. The drying device may further include a second heater located near the other of the upper and lower surfaces so as to irradiate electromagnetic waves toward the window located on the other of the upper and lower surfaces. The second heater may have the same configuration as the first heater. With this configuration, electromagnetic waves can be irradiated onto both sides of the resin film being transported within the first space. This allows the resin film to be dried more efficiently. [Example]

[0021] Example 1 The drying device 10 will be described with reference to the drawings. The drying device 10 is used to dry a solvent applied to the surface of a resin film 2. In this embodiment, the resin film 2 is a polyethylene film or polypropylene film used as a separator for lithium-ion batteries. As shown in FIG. 1, the drying device 10 includes a furnace body 12, a conveying device 20, a heater 40, an air supply device 60, an exhaust device 62, and an air supply nozzle 64.

[0022] The furnace body 12 has a substantially rectangular parallelepiped shape, and a partition wall 14 is disposed inside. The furnace body 12 and the partition wall 14 are formed of a non-ferrous metal, such as an aluminum alloy or stainless steel. The inner surface of the furnace body 12 may be polished to improve the reflectivity of the electromagnetic waves (described in detail later) radiated from the heater 40. The partition wall 14 is disposed substantially parallel to the upper and lower surfaces of the furnace body 12, and divides the space inside the furnace body 12 into two spaces, a lower space and an upper space. Hereinafter, the space below the partition wall 14 will be referred to as a first space 16, and the space above the partition wall 14 will be referred to as a second space 18.

[0023] The conveying device 20 conveys the resin film 2 within the first space 16. The conveying device 20 includes a feed roller 22, a feed guide roller 24, a take-up roller 26, and a take-up guide roller .

[0024] The resin film 2 before processing (specifically, before the solvent is applied) is wound around the feed roller 22. The resin film 2 is supplied from the feed roller 22 and taken up by the take-up roller 26 via the feed guide roller 24 and the take-up guide roller 28. The feed roller 22 and the take-up roller 26 are rotated by a motor (not shown). The resin film 2 is transported by the rotation of the feed roller 22 and the take-up roller 26. Alternatively, only the take-up roller 26 may be rotated by the motor.

[0025] The feed roller 22 and the feed guide roller 24 are arranged upstream in the conveying direction of the resin film 2 (the -X direction in FIG. 1). The feed roller 22 and the feed guide roller 24 are arranged outside the furnace body 12. A through hole 12a is provided on the surface of the furnace body 12 facing the feed roller 22 (the surface in the -X direction in FIG. 1). The through hole 12a connects the outside of the furnace body 12 with the first space 16. The resin film 2 supplied from the feed roller 22 is fed by the feed guide roller 24 and conveyed from the outside to the inside of the furnace body 12 (more specifically, the first space 16) via the through hole 12a.

[0026] In addition, a solvent applicator 30 is provided near the feed guide roller 24. The solvent applicator 30 applies a solvent to the surface of the resin film 2 (the upper surface of the resin film 2 in FIG. 1) that is fed out by the feed guide roller 24. Therefore, upstream in the conveying direction of the resin film 2 (the -X direction in FIG. 1), the untreated resin film 2 is supplied from the feed roller 22, and the solvent is applied to the surface of the resin film 2 by the solvent applicator 30. The resin film 2 with the solvent applied to its surface is fed into the first space 16 through the through hole 12a by the feed guide roller 24. The resin film 2 with the solvent applied to its surface is carried into the first space 16 through the through hole 12a and transported through the first space 16.

[0027] The winding roller 26 and the winding guide roller 28 are arranged downstream in the conveying direction of the resin film 2 (the +X direction in FIG. 1). The winding roller 26 and the winding guide roller 28 are arranged outside the furnace body 12. A through hole 12b is provided in the surface of the furnace body 12 facing the winding roller 26 (the surface in the +X direction in FIG. 1). The through hole 12b connects the first space 16 to the outside of the furnace body 12. The resin film 2 sent from the inside of the furnace body 12 (more specifically, the first space 16) to the outside through the through hole 12b is sent to the winding roller 26 via the winding guide roller 28 and is taken up by the winding roller 26.

[0028] The resin film 2 is supplied from the delivery roller 22, and after the solvent is applied to its surface in the solvent application section 30, it is transported through the drying device 10. While being transported through the drying device 10, the solvent applied to the surface of the resin film 2 is dried by electromagnetic waves (described in detail later) emitted from the heater 40. The resin film 2, whose surface has now been dried from the solvent applied thereto, is taken up by the take-up roller 26 via the take-up guide roller 28.

[0029] The heater 40 is installed in the second space 18. The heater 40 is cylindrical and extends in a direction (Y direction in FIG. 1) perpendicular to the conveyance direction of the resin film 2. In the second space 18, multiple heaters 40 are arranged at intervals in the conveyance direction of the resin film 2 (X direction in FIG. 1).

[0030] 2, the heater 40 includes a heating element 42, an inner tube 44, and an outer tube 46. The heating element 42 radiates electromagnetic waves when heated by electrical current.

[0031] The inner tube 44 covers the outer periphery of the heating element 42. The inner tube 44 is made of a material that transmits electromagnetic waves in a wavelength band less than 4.0 μm and absorbs electromagnetic waves in a wavelength band of 4.0 μm or more. In this embodiment, the inner tube 44 is made of quartz. Of the electromagnetic waves irradiated from the heating element 42, those in a wavelength band less than 4.0 μm transmit through the inner tube 44, while those in a wavelength band of 4.0 μm or more are absorbed by the inner tube 44 and are hardly transmitted. On the other hand, the electromagnetic waves in the wavelength band of 4.0 μm or more are absorbed by the inner tube 44, thereby heating the inner tube 44. When the inner tube 44 is heated by the electromagnetic waves in the wavelength band of 4.0 μm or more, the inner tube 44 itself becomes a radiator of the electromagnetic waves in the wavelength band of 4.0 μm or more, and secondary radiation of the electromagnetic waves in the wavelength band of 4.0 μm or more is emitted from the inner tube 44.

[0032] The outer tube 46 covers the outer periphery of the inner tube 44. The outer tube 46 is also made of a material that transmits electromagnetic waves in a wavelength band less than 4.0 μm and absorbs electromagnetic waves in a wavelength band of 4.0 μm or more, and in this embodiment, the outer tube 46 is also made of quartz. A cooling fluid (e.g., cooling gas) flows in a space 48 between the outer tube 46 and the inner tube 44.

[0033] When the inner tube 44 absorbs electromagnetic waves in a wavelength band of 4.0 μm or more and is heated, the inner tube 44 emits secondary radiation of electromagnetic waves in a wavelength band of 4.0 μm or more. The secondary radiation of the electromagnetic waves in a wavelength band of 4.0 μm or more from the inner tube 44 is then emitted between the inner tube 44 and the outer tube 46. By flowing a cooling fluid through the space 48 between the outer tube 46 and the inner tube 44, the inner tube 44 and the outer tube 46 can be cooled, and an increase in the temperatures of the inner tube 44 and the outer tube 46 can be suppressed. Furthermore, because the outer tube 46 absorbs electromagnetic waves in a wavelength band of 4.0 μm or more, even if the electromagnetic waves in the wavelength band of 4.0 μm or more radiated between the inner tube 44 and the outer tube 46 reach the outer tube 46, they are absorbed by the outer tube 46. Therefore, the electromagnetic waves in the wavelength band of 4.0 μm or more are not irradiated to the outside of the outer tube 46 (i.e., the outside of the heater 40). Therefore, the heater 40 emits electromagnetic waves in a wavelength band of less than 4.0 μm, and hardly emits electromagnetic waves in a wavelength band of 4.0 μm or more.

[0034] In this embodiment, the inner tube 44 and the outer tube 46 function as low-pass filters that absorb electromagnetic waves in a wavelength band of 4.0 μm or more. That is, most of the electromagnetic waves emitted from the heater 40 (i.e., the electromagnetic waves that are transmitted to the outside of the outer tube 46 located at the outermost periphery of the heater 40) are electromagnetic waves in a wavelength band of less than 4.0 μm, and most of these are electromagnetic waves in a wavelength band of less than 3.5 μm. Specifically, 80% or more of the electromagnetic waves emitted from the heater 40 are infrared energy in a wavelength band of less than 4.0 μm, and 20% or less are infrared energy in a wavelength band of 4.0 μm or more. While most of the electromagnetic waves emitted from the heater 40 are electromagnetic waves in a wavelength band of less than 4.0 μm, they may also include visible light and ultraviolet light.

[0035] In this embodiment, most of the electromagnetic waves emitted from the heater 40 are in a wavelength band of less than 4.0 μm, so the outer surface of the heater 40 is less likely to reach a high temperature than a heater that does not block electromagnetic waves in a wavelength band of 4.0 μm or more. Specifically, while the surface temperature of a heater that does not block electromagnetic waves in a wavelength band of 4.0 μm or more exceeds 200°C, the surface temperature of the heater 40 in this embodiment is kept below 200°C. This makes it possible to prevent the second space 18 in which the heater 40 is installed from reaching a high temperature.

[0036] Furthermore, in this embodiment, because the heater 40 irradiates electromagnetic waves in a wavelength band of less than 4.0 μm, substances containing functional groups that readily absorb electromagnetic waves in a wavelength band of less than 4.0 μm (e.g., OH groups, NH groups, CH groups, etc.) can be efficiently evaporated. A substance containing functional groups that readily absorb electromagnetic waves in a wavelength band of less than 4.0 μm is often used as the solvent applied to the resin film 2. By irradiating electromagnetic waves in a wavelength band of less than 4.0 μm from the heater 40, the solvent applied to the resin film 2 can be efficiently evaporated. Note that most of the electromagnetic waves irradiated from the heater 40 are in a wavelength band of less than 4.0 μm, and therefore, hereinafter, the electromagnetic waves irradiated from the heater 40 will also be simply referred to as "electromagnetic waves in a wavelength band of less than 4.0 μm."

[0037] Here, the partition wall 14 separating the first space 16 and the second space 18 will be described. As shown in FIG. 1, the partition wall 14 is disposed between the first space 16 and the second space 18. The partition wall 14 has a plurality of windows 50. The windows 50 are provided along the transport direction of the resin film 2, and a heater 40 is installed near each window 50. The windows 50 are provided so that electromagnetic waves emitted from the heater 40 installed in the second space 18 can be irradiated onto the resin film 2 transported within the first space 16. Specifically, the partition wall 14 has a plurality of through holes 14a provided along each heater 40, and the windows 50 are installed in the through holes 14a.

[0038] As shown in FIG. 3 , the window 50 includes a support frame 52, a glass plate 54, and a sealing member 56. The support frame 52 is provided in the through-hole 14a. The support frame 52 is formed of a non-ferrous metal such as an aluminum alloy or stainless steel, and supports the glass plate 54. The glass plate 54 is transparent to the electromagnetic waves irradiated from the heater 40 and transmits the electromagnetic waves irradiated from the heater 40 from the second space 18 to the first space 16. As described above, the heater 40 irradiates electromagnetic waves in a wavelength band of less than 4.0 μm. Therefore, the electromagnetic waves transmitted through the glass plate 54 and irradiated into the first space 16 are electromagnetic waves in a wavelength band of less than 4.0 μm. Furthermore, the furnace body 12 and the partition wall 14 are formed of a non-ferrous metal and therefore do not transmit the electromagnetic waves irradiated from the heater 40. Therefore, the electromagnetic waves are irradiated into the first space 16 only through the glass plate 54. The electromagnetic waves in the wavelength band less than 4.0 μm that have passed through the glass plate 54 are irradiated onto the resin film 2 being transported within the first space 16. This causes the solvent applied to the resin film 2 to evaporate. Although the glass plate 54 is used in this embodiment, it does not have to be a glass plate as long as it is made of an inorganic material that contains almost no OH groups, such as quartz, alumina, or sapphire. By using a plate made of an inorganic material that contains almost no OH groups, electromagnetic waves in the wavelength band less than 4.0 μm can be transmitted.

[0039] The sealing member 56 is disposed between the support frame 52 and the glass plate 54, sealing the gap between the support frame 52 and the glass plate 54. By sealing the gap between the support frame 52 and the glass plate 54 with the sealing member 56, gas transfer between the first space 16 and the second space 18 can be prevented. Because the solvent applied to the resin film 2 evaporates in the first space 16, the gas in the first space 16 contains the evaporated solvent. An organic solvent may be used as the solvent, and the evaporated gas may explode if heated to high temperatures. The heater 40 is installed in the second space 18. In this embodiment, the heater 40 radiates electromagnetic waves in a wavelength band of less than 4.0 μm, so the surface temperature of the heater 40 is unlikely to become high. However, if the heater 40 is continuously operated, the second space 18 in which the heater 40 is installed will become hotter than the first space 16 in which the heater 40 is not installed. By sealing the gap between the support frame 52 and the glass plate 54 with the sealing member 56, it is possible to prevent the gas resulting from the evaporation of the solvent in the first space 16 from moving into the second space 18. This makes it possible to prevent the gas resulting from the evaporation of the solvent from becoming too hot in the second space 18 due to the heater 40 and exploding.

[0040] 1, the air supply device 60 is configured to supply atmospheric gas into the first space 16. Specifically, an air supply port 60a of the air supply device 60 is provided downstream in the conveyance direction of the resin film 2 (+X direction side in FIG. 1), and the air supply device 60 supplies atmospheric gas to the downstream side in the conveyance direction of the resin film 2. In this embodiment, the air supply device 60 supplies atmospheric gas from the upper surface of the furnace body 12, passes through a supply flow path 61 provided along the downstream surface of the furnace body 12 in the conveyance direction of the resin film 2 (+X direction surface in FIG. 1), and is supplied into the first space 16 from the air supply port 60a.

[0041] The exhaust device 70 is configured to exhaust atmospheric gas from the inside of the furnace body 12. The exhaust device 70 includes a first exhaust passage 72 and a second exhaust passage 74.

[0042] The first exhaust flow path 72 is configured to exhaust atmospheric gas from the first space 16 to the outside of the furnace body 12. Specifically, an exhaust port 72a provided at one end of the first exhaust flow path 72 opens into the first space 16 and is provided upstream in the conveyance direction of the resin film 2 (the -X direction side in FIG. 1). The atmospheric gas in the first space 16 is exhausted into the first exhaust flow path 72 from the exhaust port 72a upstream in the conveyance direction of the resin film 2. The first exhaust flow path 72 is provided along the surface of the furnace body 12 upstream in the conveyance direction of the resin film 2 (the surface in the -X direction in FIG. 1), and extends through the upper surface of the furnace body 12 to the outside of the furnace body 12. Therefore, the atmospheric gas in the first space 16 is exhausted from the first space 16 through the exhaust port 72a to the first exhaust flow path 72, and then through the first exhaust flow path 72 to be exhausted from the upper surface of the furnace body 12 to the outside of the furnace body 12. The amount of atmospheric gas exhausted from the first exhaust flow path 72 is adjusted to be greater than the amount of atmospheric gas supplied from the air supply device 60. In other words, external air flows into the first space 16 through the through holes 12a and 12b.

[0043] The second exhaust flow path 74 is configured to exhaust atmospheric gas from the second space 18 to the outside of the furnace body 12. Specifically, an exhaust port 74a of the second exhaust flow path 74 is provided on the upper surface of the furnace body 12, and exhausts atmospheric gas in the second space 18 from the top of the furnace body 12 to the outside of the furnace body 12. The end of the second exhaust flow path 74 opposite the exhaust port 74a is connected to the first exhaust flow path 72 above the furnace body 12. The atmospheric gas in the second space 18 is exhausted from the second space 18 through the exhaust port 74a to the second exhaust flow path 74, and merges with the atmospheric gas exhausted from the first space 16 via the first exhaust flow path 72.

[0044] The air supply device 60 supplies atmospheric gas to the first space 16, and the exhaust device 70 exhausts the atmospheric gas from the first space 16. This creates an atmospheric gas flow within the first space 16 by the air supply device 60 and the exhaust device 70. The air supply device 60 supplies atmospheric gas downstream in the conveying direction of the resin film 2, and the exhaust device 70 exhausts atmospheric gas from upstream in the conveying direction of the resin film 2. This causes the atmospheric gas within the first space 16 to flow in the opposite direction to the conveying direction of the resin film 2. In the first space 16, the solvent evaporates from the resin film 2. Because a large amount of solvent remains on the surface of the resin film 2 upstream in the conveying direction of the resin film 2, the concentration of the solvent evaporated from the surface of the resin film 2 is likely to be higher upstream than downstream in the conveying direction of the resin film 2. By flowing the atmospheric gas within the first space 16 in the opposite direction to the conveying direction of the resin film 2, it is possible to prevent gas containing a high concentration of solvent from moving downstream in the conveying direction of the resin film 2. Therefore, it is possible to prevent the gas containing a high concentration of solvent from coming into contact with the resin film 2 on the downstream side, from which most of the solvent has already evaporated and dried.

[0045] Furthermore, the amount of atmospheric gas exhausted from the exhaust device 70 is set to be greater than the amount of atmospheric gas supplied from the air supply device 60. This creates a negative pressure within the first space 16. That is, the first space 16 has a negative pressure relative to the second space 18. By creating a negative pressure in the first space 16 relative to the second space 18, gas is less likely to move from the first space 16 to the second space 18. As described above, the first space 16 and the second space 18 are isolated by the sealing member 56 provided on the window 50, and therefore gas does not normally move between the first space 16 and the second space 18. However, for example, deterioration of the sealing member 56 or damage to the glass plate 54 may cause a state in which gas can physically move between the first space 16 and the second space 18. By making the first space 16 more negative pressure than the second space 18, even if a state is created in which gas can move between the first space 16 and the second space 18, it becomes difficult for the gas to move from the first space 16 to the second space 18. This makes it possible to more reliably prevent the gas resulting from evaporation of the solvent in the first space 16 from moving to the second space 18 in which the heater 40 is installed.

[0046] The air supply nozzle 64 is installed in the second space 18. The air supply nozzle 64 is installed near each window 50. The air supply port 64a of the air supply nozzle 64 opens toward the surface of the glass plate 54 (specifically, the surface on the second space 18 side), and the air supply nozzle 64 blows atmospheric gas onto the surface of the glass plate 54. In this embodiment, the air supply nozzle 64 is installed near the end of the glass plate 54 on the +X direction side (the downstream side in the transport direction of the resin film 2), and blows atmospheric gas from the downstream side to the upstream side in the transport direction of the resin film 2.

[0047] While the drying device 10 is operating, the glass sheet 54 continues to be irradiated with electromagnetic waves emitted from the heater 40. As a result, the surface of the glass sheet 54 facing the heater 40 (i.e., the surface facing the second space 18) may become hot. If the surface of the glass sheet 54 facing the second space 18 becomes hot, the entire glass sheet 54 may become hot, and there is a risk that the first space 16 may become hot through the glass sheet 54. By blowing atmospheric gas from the air supply nozzle 64 onto the surface of the glass sheet 54 facing the second space 18, the temperature of the surface of the glass sheet 54 facing the second space 18, which is prone to becoming hot, can be lowered. This prevents the glass sheet 54 from becoming hot, and also prevents the first space 16 from becoming hot through the glass sheet 54.

[0048] Example 2 In the first embodiment, the drying apparatus 10 includes the exhaust device 70 that exhausts the atmospheric gas from above, but is not limited to this configuration. For example, as shown in FIG. 4, the drying apparatus 110 may include an exhaust device 170 that exhausts the atmospheric gas from below, in addition to the exhaust device 70 that exhausts the atmospheric gas from above. The drying apparatus 110 of this embodiment is configured similarly to the drying apparatus 10 of the first embodiment except that the exhaust device 170 is added to the drying apparatus 10 of the first embodiment. Therefore, the following description will focus on the exhaust device 170. The drying apparatus 110 of this embodiment includes two exhaust devices 70 and 170, and therefore the exhaust device 70 may be referred to as the "first exhaust device 70" and the exhaust device 170 may be referred to as the "second exhaust device 170."

[0049] The second exhaust device 170 is disposed below the furnace body 12. In this embodiment, an exhaust port 172 is provided on the lower surface of the furnace body 112. The second exhaust device 170 is configured to exhaust the atmospheric gas in the first space 16 to the outside of the furnace body 112 through the exhaust port 172. In this embodiment, the lower surface of the furnace body 112 (more specifically, the inner surface of the lower surface) is inclined so that the exhaust port 172 is located at the lowest point. The first space 16 contains gas evaporated from the resin film 2. Since the gas evaporated from the resin film 2 is generally heavier than air, it moves downward in the first space 16. Because the lower surface of the furnace body 12 is inclined toward the exhaust port 172, the gas evaporated from the resin film 2 can easily move toward the exhaust port 172, making it easier to exhaust the gas evaporated from the resin film 2 through the exhaust port 172. Furthermore, even if the gas (solvent) evaporated from the resin film 2 is liquefied again, the liquefied solvent will be more likely to move toward the exhaust port 172, and the liquefied solvent can be prevented from accumulating inside the furnace body 112.

[0050] Example 3 In the above-described Examples 1 and 2, the resin film 2 is transported by the rollers 22, 24, 26, and 28 installed outside the furnace body 12, but the present invention is not limited to such a configuration. For example, the resin film 2 may be transported while being supported by a transport member installed inside the furnace body 12.

[0051] 5, the drying device 210 includes conveying devices (222, 224). The drying device 210 of this embodiment differs from the drying device 10 of the first embodiment in that the drying device 210 includes conveying devices (222, 224) instead of the conveying device 20, but the other configurations are substantially the same. Therefore, the following will describe the conveying devices (222, 224).

[0052] The conveying device (222, 224) includes a plurality of conveying rollers 222 and a driving device 224. The plurality of conveying rollers 222 are disposed within the first space 16 of the furnace body 12. The plurality of conveying rollers 222 all have the same diameter and are disposed at equal intervals in the conveying direction (X direction in FIG. 5 ). The conveying rollers 222 are supported rotatably about their axes and rotate when a driving force from a driving device 224 is transmitted to the conveying rollers 222. The driving device 224 is a driving device (e.g., a motor) that drives the conveying rollers 222. The resin film 2 is placed on the conveying rollers 222 and is conveyed within the first space 16 by the conveying rollers 222. Therefore, the resin film 2 can be supported and conveyed within the first space 16. Note that, although the drying device 210 includes only the first exhaust device 70 in this embodiment, it may include both the first exhaust device 70 and the second exhaust device 170.

[0053] In this embodiment, the resin film 2 is transported while being supported by the transport rollers 222, but this configuration is not limited to this. For example, instead of the transport rollers 222, the resin film 2 may be transported using a belt disposed in the first space 16. Even when the resin film 2 is transported using a belt, the resin film 2 can be transported while being supported in the first space 16.

[0054] Example 4 In the above-described first to third embodiments, the first space 16 and the second space 18 are separated by the partition wall 14 fixed to the center of the furnace body 12, but the present invention is not limited to this configuration. For example, as shown in FIG. 6, the first space 316 and the second space 318 may be separated by installing a tubular member 80 inside the furnace body 312. The drying apparatus 310 of this embodiment differs from the drying apparatus 10 of the above-described first embodiment in that the first space 316 and the second space 318 are separated by the tubular member 80, but the other configurations are substantially the same. Therefore, the configuration of the tubular member 80 will be described below.

[0055] 6 and 7, the tubular member 80 is a generally rectangular parallelepiped with both ends open, and its axis extends in the conveying direction (X direction in FIG. 6). The tubular member 80 is open on the inlet and outlet sides in the conveying direction. Flanges 82 are provided at the openings on the inlet and outlet sides of the tubular member 80. Within the furnace body 312, multiple tubular members 80 are connected in series in the conveying direction, and the flanges 82 of adjacent tubular members 80 are sealed.

[0056] A glass plate 154a is fitted on the upper surface of the tubular member 80, and a glass plate 154b is fitted on the lower surface. Specifically, support frames (not shown) are formed on the upper and lower surfaces of the tubular member 80, and the glass plates 154a and 154b are supported by the support frames. The gap between the support frames and the glass plates 154a and 154b is sealed by a sealing member (not shown).

[0057] A heater 40 and an air supply nozzle 64 are installed near the upper and lower surfaces of the tubular member 80. Note that in FIG. 7, the air supply nozzle 64 and the lower glass plate 154b are omitted for clarity. The heater 40 extends in a direction perpendicular to the conveyance direction. A plurality of heaters 40 are installed in the furnace body 312 at intervals in the conveyance direction. In this embodiment, two heaters 40 are installed near one glass plate 154a. Note that the number of heaters 40 installed near one glass plate 154a is not particularly limited. Furthermore, the heaters 40 and the air supply nozzle 64 have the same configuration as the heater 40 and the air supply nozzle 64 of the first embodiment, and therefore detailed description thereof will be omitted.

[0058] In this embodiment, heaters 40 are installed near both the top surface and the bottom surface of tubular member 80. Therefore, electromagnetic waves are irradiated onto first space 316 inside tubular member 80 from above, and also from below. That is, electromagnetic waves are irradiated onto resin film 2 being transported through first space 316 inside tubular member 80 from above, and also from below. Therefore, the solvent applied to resin film 2 can be evaporated in a shorter time, and the length of furnace body 312 in the transport direction can be shortened.

[0059] Furthermore, in this embodiment, by sealing the gap between the support frame and the glass plates 154a, 154b, gas transfer between the first space 316 inside the tubular member 80 and the second space 318 inside the furnace body 312 and outside the tubular member 80 can be prevented. The flanges 82 of two adjacent tubular members 80 are also sealed. This prevents gas transfer between the first space 316 and the second space 318 from between the adjacent tubular members 80. The resin film 2 is transported in the first space 316 inside the tubular member 80, and the heater 40 is installed in the second space 318 outside the tubular member 80. Preventing gas transfer between the first space 316 and the second space 318 prevents gas resulting from evaporation of the solvent in the first space 316 from transferring to the second space 318.

[0060] The drying apparatus 310 of this embodiment uses a tubular member 80 to separate a first space 316, through which the resin film 2 is transported, from a second space 318, in which the heater 40 is installed. The solvent evaporated from the resin film 2 may move downward within the first space 316 and re-liquefy. Transporting the resin film 2 within the tubular member 80 prevents the liquefied solvent from accumulating on the bottom surface of the furnace body 312. Furthermore, by forming the first space 316 using the tubular member 80, the cross-sectional area of ​​the first space 316 in a direction perpendicular to the transport direction can be reduced. This makes it easier to maintain a negative pressure in the first space 316. Furthermore, reducing the cross-sectional area of ​​the first space 316 in a direction perpendicular to the transport direction can increase the flow rate of the ambient gas generated by the air supply device 60 and the exhaust device 70. This facilitates exhausting the gas within the first space 316 and evacuating the solvent evaporated from the resin film 2.

[0061] Although the heaters 40 are provided both above and below the tubular member 80 in this embodiment, the present invention is not limited to this configuration. For example, as shown in FIG. 8 , the heater 40 may be provided only above the tubular member 80, and no heater 40 may be provided below the tubular member 80. The drying device 410 of FIG. 8 differs from the drying device 310 of FIG. 7 only in that the heater 40 is not provided below the tubular member 80, and the other configurations are substantially the same. The drying device 410 can also prevent the liquefied solvent from accumulating on the bottom surface of the furnace body 312, and can easily create a negative pressure in the first space 316 and exhaust the solvent evaporated from the resin film 2. Alternatively, unlike the embodiment shown in FIG. 8 , the heater may be provided only below the tubular member 80, and no heater may be provided above the tubular member 80.

[0062] Points to note regarding the drying apparatus 10 described in the embodiment will be described below. The furnace body 12 in the embodiment is an example of a "housing," the inner tube 44 is an example of a "first tube," the outer tube 46 is an example of a "second tube," the glass plate 54 is an example of a "transparent body," the air inlet 64a of the air inlet nozzle 64 is an example of an "air inlet," and the exhaust outlet 172 is an example of an "exhaust outlet."

[0063] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Furthermore, the technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings simultaneously achieves multiple objectives, and achieving one of those objectives itself has technical utility. [Explanation of symbols]

[0064] 2: Resin film 10, 110, 210, 310, 410: Drying equipment 12, 112, 312: Furnace body 14: Bulkhead 16, 316: 1st space 18, 318: 2nd space 20:Transportation device 40: Heater 42: Heating element 44: Inner tube 46:Outer tube 50: Window 52: Support slot 54: Glass plate 56: Sealing material 60:Air supply device 64: Air supply nozzle 70: First exhaust device 80: Tubular member 82: Flange 170: Second exhaust system 172: Exhaust port of second exhaust system 222: Conveyor roller 224: Drive unit

Claims

1. A drying device for drying a solvent on a resin film, comprising: Housing and a plurality of tubular members disposed within the housing, extending in a transport direction of the resin film, and configured so that the resin film is transported therethrough, the plurality of tubular members having a partition wall separating a space within the housing into a first space that is a space inside the plurality of tubular members and a second space that is a space outside the plurality of tubular members; a conveying device that conveys the resin film within the first space; a first heater disposed in the second space and configured to irradiate electromagnetic waves onto the resin film being transported by the transport device; a window disposed in the partition wall and capable of transmitting electromagnetic waves irradiated from the first heater; It is equipped with the first heater is configured to irradiate the resin film with electromagnetic waves in a wavelength band of less than 4.0 μm and to absorb electromagnetic waves in a wavelength band of 4.0 μm or more; the plurality of tubular members are connected in series in the conveying direction, The adjacent tubular members are sealed to each other, the partitions are upper and lower surfaces of the tubular member; the window is disposed on at least one of the upper surface and the lower surface; The drying device, wherein the first heater is positioned near one of the upper surface and the lower surface so as to irradiate electromagnetic waves toward the window positioned on one of the upper surface and the lower surface.

2. The drying device according to claim 1 , wherein the first heater is configured to irradiate the resin film with electromagnetic waves in a wavelength band of 3.5 μm or less and to absorb electromagnetic waves in a wavelength band of 3.5 μm or more.

3. The first heater comprises: a heating element extending in a direction perpendicular to a conveying direction in which the resin film is conveyed; a first tube disposed on the outer periphery of the heating element and surrounding the heating element; a second tube disposed around the first tube and surrounding the first tube; The drying device according to claim 1 , wherein the first tube and the second tube are formed of a material that absorbs electromagnetic waves in a wavelength band of 4.0 μm or more.

4. The drying device according to claim 1 , wherein the first heater irradiates the resin film with electromagnetic waves containing 80% or more of infrared energy in a wavelength band of less than 4.0 μm.

5. The drying device according to claim 1 , wherein the first heater irradiates the resin film with electromagnetic waves including visible light and ultraviolet light.

6. the window includes a support frame provided in the partition wall and a transparent body supported by the support frame and capable of transmitting electromagnetic waves irradiated from the first heater, The drying device according to claim 1 , wherein a seal is formed between the support frame and the permeable body.

7. an air supply device that supplies atmospheric gas to at least one of the first space and the second space; an exhaust device that exhausts atmospheric gas from at least one of the first space and the second space, 2. The drying apparatus according to claim 1, wherein the first space is maintained at a negative pressure relative to the second space by the air supply device and the exhaust device.

8. The drying device according to claim 1 , further comprising an air supply port that opens into the second space and blows gas toward the window.

9. the window is further provided on the other of the upper surface and the lower surface, a second heater disposed near the other of the upper surface and the lower surface so as to irradiate electromagnetic waves toward the window disposed on the other of the upper surface and the lower surface, The drying device according to any one of claims 1 to 8, wherein the second heater has the same configuration as the first heater.

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