Drying furnace

Abstract

Provided is a drying furnace capable of detecting the state of a coating film during drying and capable of suppressing variations in properties of a film obtained by drying the coating film. A drying furnace according to an embodiment of the present invention is provided with a furnace body, a heater, and a sensor. The furnace body is a furnace body through which a carrier sheet supporting a coating film can pass. The furnace body is provided with a light-transmitting part. The heater can heat the coating film. The sensor is capable of optically detecting the state of the coating film heated by the heater via the light-transmitting part from a side opposite to the coating film with respect to the light-transmitting part.

Description

TECHNICAL FIELD

[0001] The present application relates to a drying furnace. BACKGROUND

[0002] In the past, it has been known to dry a coating film to produce a film product. As a drying device for such a coating film, for example, a drying device is proposed which includes a drying zone that dries a coating film formed by coating a substrate, and generates an air flow in parallel with the transport direction of the coating film (for example, refer to Patent Literature 1).

[0003] In recent years, the use of film products is diversified, and it is desired to precisely control the properties of the film product corresponding to the use. However, if the coating film is dried using the drying device described in Patent Literature 1, it is difficult to confirm the state of the coating film in the middle of drying, and there is a problem that the properties of the film produced can deviate.

[0004] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature 1: Japanese Patent Application Laid-Open No. 2008-302297 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION The main object of the present application is to provide a drying furnace which can detect the state of a coating film at the time of drying, and can suppress the deviation of the properties of a film obtained by drying the coating film.

[0006] MEANS OF SOLVING THE PROBLEMS [1] A drying furnace according to an embodiment of the present application includes a furnace body, a heater, and a sensor. The furnace body is a furnace body through which a carrier sheet supporting a coating film can pass. The furnace body includes a light-transmitting portion. The heater can heat the coating film. The sensor can optically detect the state of the coating film heated by the heater from a side opposite to the coating film with respect to the light-transmitting portion, via the light-transmitting portion.

[0007] [2] In the drying furnace described in the above [1], the heater can further change the output based on the detection result of the sensor.

[0008] [3] In the drying furnace described in the above [1] or [2], the heater can be an infrared heater that can radiate infrared rays. The infrared heater can be disposed on a side opposite to the coating film with respect to the light-transmitting portion.

[0009] [4] The drying furnace described in any one of the above [1] to [3] can further include an air flow generating portion. The air flow generating portion is configured to generate an air flow in an internal space of the furnace body.

[0010] [5] In the drying furnace described in [4] above, the airflow generation portion can also change the direction and / or the amount of airflow based on the detection results of the sensor.

[0011] Effects of Invention According to the embodiment of the present application, a drying furnace capable of detecting the state of a coating film during drying and suppressing the variation in the properties of a film obtained by drying the coating film can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a schematic perspective view of a drying furnace according to an embodiment of the present application.

[0013] Figure 2 is a schematic structural view of a heater provided in the drying furnace of Figure 1

[0014] Figure 3 is a sectional view of the heater of Figure 2 DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings, but the present application is not limited to these embodiments. In addition, the drawings are such that, in order to make the description more clear, the width, thickness, shape, etc. of each portion are schematically represented compared to the embodiments, but this is only an example and does not limit the explanation of the present application.

[0016] A. Schematic of Drying Furnace Figure 1 is a schematic structural view of a drying furnace according to an embodiment of the present application.

[0017] The drying furnace 100 of the illustrated example is provided with a furnace body 1, a heater 2, and a sensor 3. The furnace body 1 has a hollow shape, for example. A carrier sheet 6 that supports a coating film 71 can pass through the inside space of the furnace body 1. The furnace body 1 is provided with a light-transmitting portion 12. The heater 2 can heat the coating film 71. The sensor 3 can optically detect the state of the coating film 71 after being heated by the heater 2 from the side opposite to the coating film 71 with respect to the light-transmitting portion 12 via the light-transmitting portion 12. That is, the sensor 3 is located outside the furnace body 1.

[0018] According to such a structure, the state of the coating film passing through the inside of the furnace body can be optically detected by the sensor located outside the furnace body while the coating film is dried by the heater. Therefore, the variation in the properties of a film obtained by drying the coating film can be suppressed.

[0019] ​​In one embodiment, the heater 2 is capable of changing the output based on the detection result of the sensor 3. That is, the output of the heater can be adjusted according to the state of the coating film detected by the sensor. Thus, the drying conditions of the coating film can be properly adjusted, and a film having desired properties can be stably manufactured.

[0020] In one embodiment, the drying furnace 100 is further provided with an airflow generating portion 4. The airflow generating portion 4 is configured to generate airflow in the internal space of the furnace body 1. Thereby, the coating film passing through the inside of the furnace body can be more smoothly dried.

[0021] In one embodiment, the airflow generating portion 4 is capable of changing the direction of airflow and / or the air volume based on the detection result of the sensor 3. That is, the direction of airflow and / or the air volume in the furnace body can be adjusted according to the state of the coating film detected by the sensor. Thus, the drying conditions of the coating film can be more properly adjusted, and a film having desired properties can be more stably manufactured.

[0022] In one embodiment, the drying furnace 100 is further provided with a control portion 5. Although not shown, the control portion 5 is electrically connected to the sensor 3, and to the heater 2 and / or the airflow generating portion 4. The control portion 5 is provided with, for example, a central processing device (CPU), a ROM, a RAM, and the like. The control portion 5 is capable of receiving the detection result from the sensor 3, and is capable of transmitting a signal (typically, an electric signal) based on the detection result to the heater 2 and / or the airflow generating portion 4.

[0023] In the present embodiment, the heater 2 is configured to change the output according to the signal transmitted from the control portion 5. In addition, the airflow generating portion 4 is configured to change the direction of airflow and / or the air volume according to the signal transmitted from the control portion 5.

[0024] As a film 72 manufactured by such a drying furnace 100, for example, a perovskite semiconductor film which can be used for a photoelectric conversion element, a lithium ion battery positive and negative electrode, various ceramic sensors, a high-function film can be cited.

[0025] Hereinafter, the detailed structure of the drying furnace 100 will be described.

[0026] B. Carrier Sheet The carrier sheet 6 is typically in a long strip shape. In the illustrated example, the long strip-shaped carrier sheet 6 is capable of moving from the unwinding roll 61 toward the winding roll 62. The carrier sheet 6 passes through the internal space of the furnace body 1 between the unwinding roll 61 and the winding roll 62.

[0027] In the unwinding roll 61, the long strip-shaped carrier sheet 6 is wound in a roll shape on a rotatable unwinding shaft 61a. After the carrier sheet 6 is drawn out from the unwinding roll 61, the carrier sheet 6 enters the furnace body 1. Before the carrier sheet 6 enters the furnace body 1, a coating liquid is applied to the carrier sheet 6 to form a coating film 71. The coating film 71 formed on the carrier sheet 6 is heated and dried by the heater 2 while passing through the inside space of the furnace body 1 by the movement of the carrier sheet 6. After that, the coating film 71 is appropriately dried to become a film 72 (dried coating film). The film 72 is discharged from the furnace body 1 in a state of being supported by the carrier sheet 6. The carrier sheet 6 supporting the film 72 is wound in a roll shape by a winding shaft 62a that is rotated by a transmission driving force, and constitutes a winding roll 62.

[0028] In one embodiment, the drying furnace 100 further has a coating section 7. The coating section 7 is located at a position more upstream than the furnace body 1 in the moving direction of the carrier sheet 6. The coating section 7 is capable of applying a coating liquid to the carrier sheet 6. The coating section 7 can have any appropriate structure.

[0029] The coating liquid contains a material component of the film 72 being manufactured, and a solvent capable of dissolving and / or dispersing the material component.

[0030] In the case where the film 72 is a perovskite semiconductor film, the coating liquid contains a compound represented by the general formula (ABX3), and a solvent capable of dissolving the compound.

[0031] As A in the general formula (ABX3), for example, an organic amino compound, an alkali metal cation can be given.

[0032] As the organic amino compound, for example, alkyl amines such as methylamine, ethylamine, n-butylamine, di-n-butylamine, di-n-hexylamine, trimethylamine, triethylamine, methyl-n-hexylamine, methyldiethylamine, tri-n-hexylamine, tri-tert-butylamine; imidazole; pyrrole; aziridine; carbazole; formamidine; guanidine; aniline; pyridine; 4-tert-butylpyridine; phenethylamine; 5-aminovaleric acid can be given.

[0033] The alkali metal cation is a monovalent cation. As the alkali metal, for example, cesium, potassium, rubidium can be given.

[0034] Such A can be used alone or in combination. Among such A, a combination of an organic amino compound and an alkali metal cation is preferable, a combination of an alkyl amine, a formamidine, and an alkali metal is more preferable, and a combination of methylamine (MA), formamidine (FA), and cesium (Cs) is further preferable.

[0035] In the case where A in the general formula (ABX3) is a combination of an alkyl amine (methylamine), a formamidine, and an alkali metal (cesium), the molar ratio of the alkyl amine with respect to 1 mole of the alkali metal is, for example, 1 to 5, and the molar ratio of the formamidine with respect to 1 mole of the alkali metal is, for example, 14 to 18.

[0036] As B in the general formula (ABX3), for example, a divalent metal cation, preferably a cation of a Group 14 element (a metal element classified as Group 14 in the periodic table determined by IUPAC in 2019) such as lead or tin can be given.

[0037] Such B can be used alone or in combination. In addition, in B, in addition to the above-mentioned divalent metal cation, a small amount of a trivalent cation such as indium or antimony can be mixed. Among these B, a cation of a Group 14 element is preferable, and a cation of lead (Pb) is more preferable.

[0038] As X in the general formula (ABX3), for example, a halogen atom, a source of anion, preferably a halogen atom can be given. As the halogen atom, for example, chlorine, bromine, and iodine can be given.

[0039] Such X can be used alone or in combination. Among these X, a halogen atom is preferable, and a combination of bromine (Br) and iodine (I) is more preferable.

[0040] As the compound represented by the general formula (ABX3), a perovskite compound having a composition of Cs 0.05 FA 0.80 MA 0.15 PdI 2.68 Br 0.32 and a perovskite compound having a composition of Cs 0.05 FA 0.80 MA 0.15 PdI 2.75 Br 0.25 are particularly preferable.

[0041] As the solvent capable of dissolving the compound represented by the above-mentioned general formula (ABX3), for example, an organic solvent, preferably N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 2-methoxyethanol can be given. The medium can be used alone or in combination.

[0042] C. Furnace body The furnace body 1 typically has a main body portion 11 and a light-transmitting portion 12.

[0043] The main body portion 11 is a portion of the furnace body 1 other than the light-transmitting portion 12. As a material of the main body portion 11, an arbitrary appropriate heat-resistant material can be given. In one embodiment, the main body portion 11 has a sensor opening 11a. The sensor opening 11a is provided at a portion opposite to the coated film 71 passing through the inside of the furnace body 1. The main body portion 11 can have one sensor opening 11a, or can have a plurality of sensor openings 11a. In the illustrated example, the main body portion 11 has two sensor openings 11a.

[0044] In one embodiment, the light-transmitting portion 12 is supported to the main body portion 11 in a manner of plugging the sensor opening 11a. Thereby, the light-transmitting portion 12 opposes the coating film 71 passing through the inside of the furnace body 1 at an interval in a thickness direction of the coating film 71.

[0045] The light-transmitting portion 12 is typically capable of transmitting light (electromagnetic wave) having a wavelength of 200 nm to 4000 nm. The total light transmittance of light having a wavelength of 200 nm to 3500 nm in the light-transmitting portion 12 is, for example, 10% to 100%.

[0046] If the light-transmitting portion 12 is capable of transmitting visible light having a wavelength of 360 nm to 830 nm, the sensor 3 is capable of detecting a visible change of the coating film 71 via the light-transmitting portion 12. In addition, in a case where the light-transmitting portion 12 is capable of transmitting infrared light having a wavelength of 1.0 μm to 4.0 μm, as will be described later in detail, by employing an infrared heater as the heater 2, it is possible to irradiate the coating film 71 passing through the inside of the furnace body 1 with infrared light from the outside of the furnace body 1 via the light-transmitting portion 12, and to dry the coating film 71.

[0047] As a material of the light-transmitting portion 12, a material that transmits electromagnetic wave in the infrared region is preferable, and quartz glass is typically exemplified. In addition, sapphire, calcium fluoride are exemplified as alternatives. The thickness of the light-transmitting portion 12 can be arbitrarily and appropriately set.

[0048] D. Sensor The sensor 3 is located in an outside space of the furnace body 1. The sensor 3 is located on a side opposite to the coating film 71 passing through the inside of the furnace body 1 with respect to the light-transmitting portion 12. The number of the sensor 3 is not particularly limited. One sensor 3 can be provided with respect to one light-transmitting portion 12, or a plurality of sensors 3 can be provided with respect to one light-transmitting portion 12.

[0049] The sensor 3 can have an arbitrary and appropriate structure as long as it is capable of optically detecting a state of the coating film 71 passing through the inside of the furnace body 1 via the light-transmitting portion 12. As a state of the coating film that the sensor is capable of detecting, for example, a color of the coating film, a surface temperature of the coating film, a smoothness of the surface of the coating film are exemplified. In one embodiment, the sensor 3 is capable of detecting a color of the coating film.

[0050] E. Heater The heater 2 can have an arbitrary and appropriate structure as long as it is capable of heating the coating film 71 passing through the inside of the furnace body 1. As the heater 2, for example, an electric heater, an infrared heater, an ultraviolet lamp are exemplified.

[0051] The heater 2 can be disposed in the inside of the furnace body 1, or can be disposed in the outside of the furnace body 1. In addition, the number of the heater 2 is not particularly limited, and is, for example, one or more, and is preferably two or more.

[0052] In the example shown, heater 2 is an infrared heater 2a capable of emitting infrared rays. The infrared heater 2a is disposed on the side opposite to the coating 71 that passes through the interior of the furnace body 1, relative to the light-transmitting portion 12. That is, the infrared heater 2a is disposed on the exterior of the furnace body 1. Therefore, compared to the case where the infrared heater is disposed inside the furnace body, the influence of heat on the infrared heater can be reduced, and a longer lifespan for the infrared heater can be achieved.

[0053] In addition, the infrared heater 2a can irradiate the coating 71 inside the furnace body 1 with infrared rays through the light-transmitting part 12, which can dry the coating 71.

[0054] In one embodiment, the infrared heater 2a is configured as a wavelength-controlled heater capable of emitting infrared rays with controlled wavelengths. The peak wavelength of the infrared rays emitted by the infrared heater 2a can be arbitrarily and appropriately adjusted according to the absorption wavelength of the solvent contained in the coating. By emitting infrared rays corresponding to the absorption wavelength of the solvent, the infrared heater can smoothly dry the coating.

[0055] The peak wavelength of the infrared radiation is, for example, 0.5 μm to 4.0 μm, preferably 1.0 μm to 3.0 μm. The half-width of the infrared spectral line is, for example, 3.0 μm or less, preferably 1.0 μm or less.

[0056] like Figure 2 As shown, the infrared heater 2a, which is configured as a wavelength-controlled heater, includes, for example, a filament 23, a first tube 21, and a second tube 22.

[0057] The filament 23 is able to emit infrared light when a voltage is applied. In the example shown, the filament 23 is disposed in the center of the internal space of the first tube 21.

[0058] The first tube 21 is disposed within the internal space of the second tube 22. The first tube 21 and the second tube 22 are arranged in a concentric circle shape sharing a central axis. The first tube 21 and the second tube 22 function as low-pass filters that absorb infrared radiation exceeding the aforementioned peak wavelength. Therefore, the first tube 21 and the second tube 22 selectively transmit infrared radiation with the aforementioned peak wavelength from the electromagnetic waves emitted from the filament 23.

[0059] The space between the first tube 21 and the second tube 22 is defined as a flow path 24. Cooling media such as air and inactive gases can pass through the flow path 24. This suppresses the release of heat generated by the filament to the outside of the irradiation unit. Figure 3 As shown, the cooling medium flows into the flow path 24 through the inlet 25 provided in the second pipe 22, and then exits from the outlet 26 provided in the second pipe 22 through the flow path 24.

[0060] In one embodiment, such an infrared heater 2a is capable of changing the output based on the detection result of the sensor 3. Typically, the infrared heater 2a receives a signal based on the detection result of the sensor 3 from the control section 5, and varies the voltage applied to the filament 23 according to the signal. Thereby, the output of the emitted infrared rays can be changed.

[0061] F. Airflow generating section As shown in FIG. 1, the drying furnace 100 can be provided with one airflow generating section 4, or can be provided with a plurality of airflow generating sections 4. In the illustrated example, the drying furnace 100 is provided with three airflow generating sections 4. Hereinafter, the three airflow generating sections 4 are sometimes distinguished as a first airflow generating section 41, a second airflow generating section 42, and a third airflow generating section 43. Figure 1

[0062] In one embodiment, the airflow generating section 4 includes a first line 44, a second line 45, and a first blower 47.

[0063] The first line 44 and the second line 45 are each typically a pipe through which gas can pass.

[0064] In the illustrated example, the first end portion of the first line 44 is located inside the furnace body. The first end portion of the first line 44 provided to the first airflow generating section 41 and the second airflow generating section 42 is located between the coated film 71 passing through the furnace body 1 and the light-transmitting section 12. The first end portion of the first line 44 provided to the third airflow generating section 43 is located at a position opposite to the coated film 71 with respect to the carrier sheet 6.

[0065] The second end portion of the first line 44 is connected to the first blower 47 outside the furnace body.

[0066] The first end portion of the second line 45 is located inside the furnace body. The first end portion of the second line 45 provided to the first airflow generating section 41 and the second airflow generating section 42 is located between the coated film 71 passing through the furnace body 1 and the light-transmitting section 12. The first end portion of the first line 44 and the first end portion of the second line 45 are opposed at intervals in the moving direction of the carrier sheet 6.

[0067] If the first end portion of the first line 44 and the first end portion of the second line 45 are arranged to be opposed at intervals in the moving direction of the carrier sheet 6, the airflow generating section 4 is capable of generating an airflow along the moving direction of the carrier sheet 6.

[0068] The first end portion of the second line 45 provided to the third airflow generating section 43 is connected to the furnace body 1 in a manner that communicates with the opening provided to the furnace body 1.

[0069] The first blower 47 is typically capable of blowing out gas (typically air). The first blower 47 can have any appropriate structure. ​

[0070] Further, the airflow generating section 4 can further include a second blower 48. If the airflow generating section includes the second blower, the airflow can be generated more stably inside the furnace. In the illustrated example, the second airflow generating section 42 and the third airflow generating section 43 include the second blower 48. The second end portion of the second line 45 is connected to the second blower 48. The second blower 48 can be described similarly to the first blower 47.

[0071] Further, the airflow generating section 4 can further include a heating body 46. If the airflow generating section includes the heating body, the temperature of the airflow generated inside the furnace can be increased. Thereby, the drying environment of the coating film can be appropriately adjusted. In the illustrated example, the second airflow generating section 42 and the third airflow generating section 43 include the heating body 46. The heating body 46 is provided to the first line 44. The heating body 46 can heat the gas passing through the first line 44. The heating body 46 can have any appropriate structure.

[0072] Further, the airflow generating section 4 can further include a blowing section 49 having a plurality of blowing outlets. In the illustrated example, the third airflow generating section 43 includes the blowing section 49. The first end portion of the first line 44 is connected to the blowing section 49. In the blowing section 49, the gas supplied from the first line 44 is divided into a plurality of airflows through the plurality of blowing outlets. The blowing section 49 can have any appropriate structure.

[0073] In one embodiment, the airflow generating sections 4 can change the direction of the airflow and / or the air volume based on the detection result of the sensor 3.

[0074] In the case of changing the air volume of the airflow, the airflow generating section 4 typically receives a signal based on the detection result of the sensor 3 from the control section 5, and varies the output of the first blower 47 and / or the second blower 48 according to the signal. Thereby, the air volume of the airflow generated inside the furnace can be appropriately adjusted.

[0075] The details of the airflow generating section 4 capable of changing the direction of the airflow are described, for example, in International Publication No. 2013 / 111647 and Japanese Patent No. 6704764. These publications are incorporated by reference in their entireties in the present specification.

[0076] In the case of changing the direction of the airflow, the airflow generating section 4 typically receives a signal based on the detection result of the sensor 3 from the control section 5, and appropriately adjusts the direction of the airflow generated inside the furnace according to the signal. More specifically, the first airflow generating section 41 and the second airflow generating section 42 generate an airflow in the same direction as the moving direction of the carrier sheet 6 (co-current) or an airflow in the opposite direction to the moving direction of the carrier sheet 6 (counter-current) according to the signal.

[0077] Industrial applicability The drying furnace according to the embodiment of the present application can be suitably used for manufacturing a film that can be used for various industrial products.

[0078] Symbol explanation 1 furnace body 2 heater 3 sensor 4 air flow generating portion 6 carrier sheet 71 coating film 100 drying furnace.

Claims

1. A drying oven, comprising: A furnace body with a light-transmitting section, which is a furnace body through which the carrier sheet supporting the coating film can pass; A heater capable of heating the coating film; and A sensor capable of optically detecting the state of the coating after it has been heated by the heater from the side opposite to the coating relative to the light-transmitting portion.

2. The drying oven according to claim 1, wherein, The heater can change its output based on the detection results of the sensor.

3. The drying oven according to claim 1 or 2, wherein, The heater is an infrared heater capable of emitting infrared rays, and is disposed on the side opposite to the coating relative to the light-transmitting part.

4. The drying oven according to claim 1 or 2, wherein, The drying oven also includes an airflow generating unit, which is configured to generate airflow in the internal space of the oven body.

5. The drying oven according to claim 4, wherein, The airflow generating unit can change the direction and / or volume of the airflow based on the detection results of the sensor.

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