阅读说明：本技术 纤维片的制造方法以及纤维片的制造装置 (Method for producing fiber sheet and apparatus for producing fiber sheet ) 是由 内田健哉 菊地佑磨 中具道 于 2021-05-19 设计创作，主要内容包括：本发明的实施方式涉及纤维片的制造方法以及纤维片的制造装置。本发明要解决的课题在于,提供一种将所制造的纤维片中所含的溶剂量抑制地较低,并且高效地干燥纤维片的纤维片的制造方法以及制造装置。根据实施方式的纤维片的制造方法,将卷绕成卷筒状的基材开卷,并且使在溶剂中溶解了有机材料的原料溶液向开卷后的基材的表面喷出,由此在基材的所述表面形成纤维片。然后,在制造方法中,将在表面形成了纤维片的基材卷取成卷筒状,并且在卷取基材之前,使形成于基材的表面的纤维片干燥。(Embodiments of the present invention relate to a method for producing a fiber sheet and an apparatus for producing a fiber sheet. The present invention addresses the problem of providing a method and an apparatus for producing a fiber sheet, which can efficiently dry the fiber sheet while keeping the amount of solvent contained in the produced fiber sheet low. According to the method of manufacturing a fiber sheet of the embodiment, the base material wound in a roll shape is unwound, and the raw material solution in which the organic material is dissolved in the solvent is discharged onto the surface of the unwound base material, thereby forming the fiber sheet on the surface of the base material. Then, in the manufacturing method, the base material having the fiber sheet formed on the surface thereof is wound up in a roll shape, and the fiber sheet formed on the surface of the base material is dried before winding up the base material.)

1. A method for producing a fiber sheet, comprising the steps of:

uncoiling the substrate wound in a roll;

forming a fiber sheet on the surface of the base material by ejecting a raw material solution in which an organic material is dissolved in a solvent onto the surface of the base material after unwinding;

winding the base material having the fiber sheet formed on the surface thereof into a roll shape; and

drying the fiber sheet formed on the surface of the substrate before winding up the substrate.

2. The method of manufacturing as set forth in claim 1,

in the drying of the fiber sheet, the fiber sheet is dried by heating the fiber sheet with infrared rays emitted from an infrared heater.

3. The manufacturing method according to claim 2, wherein the substrate is a glass substrate,

the infrared ray having a wavelength of 10 μm or less corresponding to a maximum emission intensity is emitted in heating the fiber sheet by the infrared ray.

4. The production method according to any one of claims 1 to 3,

the manufacturing method further comprises the following steps:

pressing the fiber sheet formed on the surface of the base material before taking up the base material.

5. The method of manufacturing as set forth in claim 1,

the drying of the fiber sheet causes the proportion of the solvent contained in the fiber sheet to be 0.25 mass% or more and 25 mass% or less.

6. The method of manufacturing as set forth in claim 1,

one or more of the solvents used in the raw material solution discharged onto the surface of the substrate is an organic solvent having a boiling point of 100 ℃ or higher.

7. The method of manufacturing as set forth in claim 1,

the substrate is an electrode in which an active material-containing layer containing an active material is supported on one or both surfaces of a current collector.

8. An apparatus for producing a fiber sheet, comprising:

an uncoiler for uncoiling the substrate wound in a roll shape;

a spinning head for forming a fiber sheet on the surface of the base material by discharging a raw material solution in which an organic material is dissolved in a solvent onto the surface of the base material after unwinding;

a winder that winds the base material on the surface of which the fiber sheet is formed into a roll shape; and

a dryer that dries the fiber sheet formed on the surface of the base material before winding the base material.

Technical Field

Embodiments of the present invention relate to a method for producing a fiber sheet and an apparatus for producing a fiber sheet.

Background

A method of producing a fiber sheet in which a raw material solution in which an organic material is dissolved in a solvent is discharged onto the surface of a base material by an electrospinning method or the like to form organic fibers on the surface of the base material is widely used. For example, in an electrode group of a battery, a separator for insulating between a positive electrode and a negative electrode may be integrally formed with the positive electrode or the negative electrode. In this case, a fiber sheet of organic fibers is formed on the surface of an electrode (positive electrode or negative electrode) formed integrally with the separator by an electrospinning method or the like, and the fiber sheet becomes the separator.

In the fiber sheet formed as described above, it is required to keep the amount of solvent contained in the produced fiber sheet low from the viewpoints of ensuring the durability of the fiber sheet and ensuring the performance of a product using the fiber sheet. In addition, when the amount of solvent contained in the fiber sheet is reduced by drying, for example, in the production of the fiber sheet, it is required to dry the fiber sheet efficiently.

Disclosure of Invention

The present invention addresses the problem of providing a method and an apparatus for producing a fiber sheet, which can efficiently dry the fiber sheet while keeping the amount of solvent contained in the produced fiber sheet low.

According to the method of manufacturing a fiber sheet of the embodiment, the base material wound in a roll shape is unwound, and the raw material solution in which the organic material is dissolved in the solvent is discharged onto the surface of the unwound base material, thereby forming the fiber sheet on the surface of the base material. Then, in the manufacturing method, the base material having the fiber sheet formed on the surface thereof is wound up in a roll shape, and the fiber sheet formed on the surface of the base material is dried before winding up the base material.

According to the above-mentioned method for producing a fiber sheet, the amount of solvent contained in the produced fiber sheet can be suppressed to be low, and the fiber sheet can be dried efficiently.

Drawings

Fig. 1 is a schematic view showing an apparatus for producing a fiber sheet according to a first embodiment.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings.

(first embodiment)

Fig. 1 shows a fiber sheet manufacturing apparatus 1 according to a first embodiment. As shown in fig. 1, the manufacturing apparatus 1 includes an unwinder 2, a spinning machine 3, a dryer 5, and a winder 6. In addition, the transfer line 8 is formed in the manufacturing apparatus 1. In the manufacturing apparatus 1, the base material 10 is conveyed from the uncoiler 2 to the coiler 6 via the conveyance line 8, sequentially via the spinning machine 3 and the dryer 5.

The unwinder 2 includes a reel 21. On the reel 21, the substrate 10 is wound in a roll shape. In the unwinder 2, the reel 21 is rotated in the direction of the arrow R1 by driving a driving means (not shown) such as an electric motor. Thereby, the substrate 10 wound around the reel 21 is unwound. Then, the unwound substrate 10 is sent to the conveyance line 8.

The winding machine 6 includes a reel 61. In the winding machine 6, a driving means (not shown) such as an electric motor is driven to rotate the reel 61 in the direction of the arrow R2. Thereby, the substrate 10 conveyed by the conveyance line 8 is wound into a roll shape by the reel 61.

In the manufacturing apparatus 1, the reel 21 is rotated in the direction of the arrow R1 and the reel 61 is rotated in the direction of the arrow R2, whereby the substrate 10 is conveyed from the unwinder 2 to the winder 6 via the conveyance line 8. The transport line 8 may be provided with one or more guide rollers (not shown) for guiding the base material 10 from the uncoiler 2 to the coiler 6. In this case, guide rollers are disposed on the line 8 at least at any position between the unwinder 2 and the spinning machine 3, between the spinning machine 3 and the dryer 5, and between the dryer 5 and the winder 6. Further, the guide roller may be disposed in either the spinning machine 3 or the dryer 5.

The extension state of the feed line 8 from the uncoiler 2 to the coiler 6 is not particularly limited. In one example, the transport line 8 extends in the horizontal direction, and in another example, extends in the vertical direction. Further, at least one bent portion or folded portion of the wire 8 may be provided between the uncoiler 2 and the coiler 6, and the extending direction of the wire 8 may be changed at the bent portion or folded portion. In one example, the folded portion of the transport line 8 is provided between the spinning machine 3 and the dryer 5, and in another example, the folded portion of the transport line 8 is provided in either the spinning machine 3 or the dryer 5.

The spinning machine 3 includes one or more spinning nozzles 31, and in the example of fig. 1, six spinning nozzles 31 are provided. The spinning head 31 includes a head main body 32 and nozzles 33 projecting from the head main body 32. In each of the spinning nozzles 31, only one nozzle 33 may be provided, or a plurality of nozzles may be provided. In each of the spinning heads 31, a raw material solution in which an organic material is dissolved in a solvent can be stored inside the head main body 32.

In the spinning machine 3, the base material 10 unwound from the reel 21 is conveyed toward the winder 6. The spinning machine 3 is provided with a power supply (not shown), and a voltage can be applied between the unwound base material 10 and each nozzle 33 of the spinning head 31 by the power supply. In a state where the raw material solution is contained in the head main body 32 of each spinning head 31, a voltage is applied between the base material 10 and the nozzle 33 of each spinning head 31, and the raw material solution is discharged from the nozzle 33 of each spinning head 31. At this time, the raw material solution is discharged onto the surface of the substrate 10 unwound by the unwinder 2. Thereby, the fiber sheet 11 of organic fibers is formed on the surface of the substrate 10. Therefore, the spinning machine 3 of the present embodiment forms the fiber sheet 11 by the electrospinning method.

In the example of fig. 1, the raw material solution is discharged to both surfaces of the unwound base material 10, and the fiber sheets 11 are formed on both surfaces of the base material 10. However, in one example, the raw material solution may be discharged only to one surface of the unwound substrate 10. In this case, the fiber sheet 11 is formed only on one surface of the base material 10.

As the organic material used for the raw material solution, for example, any one or more of polyolefin, polyether, polyimide, polyketone, polysulfone, cellulose, polyvinyl alcohol (PVA), polyamide, polyamideimide, and polyvinylidene fluoride (PVdf) is selected. Examples of the polyolefin include polypropylene (PP) and Polyethylene (PE).

In addition, the organic material is dissolved in the solvent at a concentration of, for example, 5 mass% or more and 60 mass% or less in each of the spinning heads 31. As a solvent for dissolving the organic material in the raw material solution, dimethylacetamide (DMAc), Dimethylsulfoxide (DMSO), N-Dimethylformamide (DMF), N-methylpyrrolidone (NMP), acetone, dimethoxyethylene, toluene, tetrahydrofuran, water, and alkanes, ketones, esters, alcohols, ethers, and the like can be used. In addition, as for the organic material having low solubility, a sheet-like organic material may be dissolved by a laser or the like. In addition, a plurality of solvents may be mixed and used in the raw material solution. Here, the one or more solvents used in the raw material solution are preferably organic solvents having a boiling point of 100 ℃ or higher. Examples of the organic solvent having a boiling point of 100 ℃ or higher include dimethylacetamide, dimethylsulfoxide, N, N-dimethylformamide, N-methylpyrrolidone, and toluene.

The voltage between each nozzle 33 of the spinning head 31 and the substrate 10 is appropriately determined according to the kind of the solvent and solute in the raw material solution, the boiling point and vapor pressure curve of the solvent of the raw material solution, the concentration and temperature of the raw material solution, the shape of the nozzle 33, the distance between the substrate 10 and the nozzle 33, and the like. In one example, the voltage between each nozzle 33 of the spinning head 31 and the substrate 10 is appropriately determined to be 1kV to 100 kV. The discharge speed of the raw material solution from each nozzle 33 of each spinning head 31 is set to a value corresponding to the concentration, viscosity, and temperature of the raw material solution, the voltage applied between each nozzle 33 of each spinning head 31 and the substrate 10, the shape of each nozzle 33, and the like.

In the spinning machine 3, the fiber sheet 11 may be formed on the surface of the base material 10 by a method other than the electrospinning method. In one example, instead of the electrospinning method, the fiber sheet 11 of organic fibers is formed on the surface of the base material 10 by any of an inkjet method, a jet dispensing method, and a spray coating method. In this case, in the spinning machine 3, a raw material solution in which an organic material is dissolved in a solvent is discharged from the spinning head 31 toward the surface of the base material 10.

In one example, in the electrode group of the battery, the separator for insulating the positive electrode and the negative electrode is formed as the above-described fibrous sheet 11. In this case, in the electrode group, one of the positive electrode and the negative electrode is formed integrally with the separator, and the electrode (positive electrode or negative electrode) formed integrally with the separator serves as the base 10. Then, the fiber sheet 11 of organic fibers is formed on the surface of the electrode formed integrally with the separator by an electrospinning method or the like. In the case where the separator integrated with the electrode (positive electrode or negative electrode) is formed as the fiber sheet 11, the fiber sheet 11 is formed of a material having electrical insulation properties. In addition, in the electrode group of the battery, the positive electrode and the negative electrode are respectively provided with a current collector and an active material containing layer containing an active material. In each of the positive electrode and the negative electrode, an active material-containing layer is supported on one surface or both surfaces of the current collector.

In the present embodiment, the fiber sheet 11 is formed on the surface of the base material 10 in the spinning machine 3 between the unwinder 2 and the winder 6 as described above. Therefore, in the winder 6, the base material 10 having the fiber sheet 11 formed on the surface thereof is wound around the reel 61.

The dryer 5 is disposed between the spinning machine 3 and the winder 6 on the conveyance line 8. Then, the base material 10 having the fiber sheet 11 formed on the surface thereof is conveyed from the spinning machine 3 to the dryer 5. Then, the dryer 5 dries the fiber sheet 11 formed on the surface of the substrate 10 before winding the substrate 10 on the reel 61 of the winder 6. Therefore, in the manufacturing apparatus 1 of the present embodiment, the fiber sheet 11 is dried by the dryer 5 in a state where the substrate 10 and the fiber sheet 11 are not wound. In the present embodiment, after the fiber sheet 11 is formed by the spinning machine 3, drying by the dryer 5 is performed without performing other steps therebetween.

In the present embodiment, the dryer 5 includes an infrared heater 51. The infrared heater 51 generates infrared rays. Then, the infrared heater 51 emits the generated infrared rays to the fiber sheet 11 formed on the surface of the base material 10. Then, in the fiber sheet 11, the functional groups contained in the organic material, the solvent, and the like absorb the infrared rays emitted from the infrared heater 51, thereby heating the fiber sheet 11 and evaporating the solvent contained in the fiber sheet 11. This reduces the amount of solvent contained in the fiber sheet 11, and the fiber sheet 11 is dried.

Here, the infrared heater 51 preferably emits infrared light having a wavelength of 10 μm or less corresponding to the maximum emission intensity to the fiber sheet 11. In this case, the temperature of the infrared heater 51 is 17 ℃ (290K) or higher in a state where infrared rays are emitted. Here, in the fiber sheet 11, many functional groups contained in organic materials, solvents, and the like easily absorb infrared rays having a wavelength of 10 μm or less. Therefore, by emitting infrared rays in a spectrum having a wavelength of 10 μm or less corresponding to the maximum emission intensity, the functional groups contained in the organic material, the solvent, and the like in the fiber sheet 11 absorb the emitted infrared rays more easily, and the solvent contained in the fiber sheet 11 is easily evaporated by heating. This further appropriately dries the fiber sheet 11. Among the functional groups contained in the solvent of the fiber sheet 11, the functional groups that readily absorb infrared rays having a wavelength of 10 μm or less include methyl groups, carbonyl groups, and the like.

In the spectrum of the infrared rays emitted from the infrared heater 51, the wavelength corresponding to the maximum emission intensity is more preferably 4 μm or more and 7 μm or less. When the wavelength corresponding to the maximum emission intensity in the spectrum of the emitted infrared ray is 7 μm or less, the temperature of the infrared heater 51 is 137 ℃ (410K) or more in the state of emitting the infrared ray. Therefore, by emitting infrared rays having a spectrum with a wavelength of 7 μm or less corresponding to the maximum emission intensity, the organic solvent having a boiling point of 100 ℃ or higher and the like are also easily evaporated, and the solvent contained in the fiber sheet 11 is further appropriately evaporated. When the wavelength corresponding to the maximum emission intensity in the spectrum of the emitted infrared ray is 4 μm or more, the temperature of the infrared heater 51 is 451 ℃ (724K) or less in the state of emitting infrared ray. This effectively prevents the temperature of the space for drying the fiber sheet 11 from becoming excessively high in the state of emitting infrared rays.

As described above, by drying the fiber sheet 11 by the dryer 5, in one example, the proportion of the solvent contained in the fiber sheet 11 after the drying by the dryer 5 is 5 mass% or more and 25 mass% or less. Further, the proportion of the solvent contained in the fiber sheet 11 after the drying by the dryer 5 is preferably 5 mass% or more and 10 mass% or less. By setting the proportion of the solvent contained in the fiber sheet 11 to 5 mass% or more and 10 mass% or less, the performance is improved in a product of the fiber sheet 11 such as a battery using a separator integrated with an electrode (positive electrode or negative electrode) as the fiber sheet 11.

The drying of the fiber sheet 11 in the dryer 5 is not limited to drying using infrared rays emitted from the infrared heater 51. In one example, the dryer 5 may dry the fiber sheet 11 with warm air instead of the infrared rays emitted from the infrared heater 51.

As described above, in the present embodiment, when the fiber sheet 11 is formed on the surface of the base material 10 by the ejection of the raw material solution, the fiber sheet 11 is dried by the dryer 5 before the base material 10 is wound by the winding machine 6. The solvent contained in the fiber sheet 11 is reduced by the drying in the dryer 5, and the amount of the solvent contained in the fiber sheet 11 is suppressed to be low in the fiber sheet 11 manufactured by the manufacturing apparatus 1. Thereby, durability of the manufactured fiber sheet 11 can be ensured, and performance of a product using the fiber sheet 11 can be ensured.

For example, in a battery in which a separator integrated with an electrode (positive electrode or negative electrode) is formed as the fiber sheet 11, the durability of the separator is improved and the durability of the battery is also improved by suppressing the amount of solvent contained in the separator as the fiber sheet 11 to be low. Further, by suppressing the amount of solvent contained in the separator as the fiber sheet 11 to be low, the internal resistance of the battery is suppressed to be low, and the output of the battery can be increased. Thereby, the performance of the battery is ensured.

In the present embodiment, as described above, the fiber sheet 11 is dried by the dryer 5 before the base material 10 is wound by the winding machine 6. That is, the fiber sheet 11 is dried by the dryer 5 in a state where the substrate 10 and the fiber sheet 11 are not wound. Therefore, the fiber sheet 11 can be dried efficiently without a long time, and the work efficiency in drying the fiber sheet 11 can be improved. Further, since the fiber sheet 11 is dried in a state where the substrate 10 and the fiber sheet 11 are not wound, the fiber sheet 11 is appropriately dried.

In addition, in the fiber sheet 11, infrared rays are often easily absorbed by functional groups contained in organic materials, solvents, and the like, and in particular, infrared rays having a wavelength of 10 μm or less are often easily absorbed. Therefore, by heating and drying the fiber sheet 11 with the infrared rays emitted from the infrared heater 51, the solvent is easily evaporated in the fiber sheet 11 by the infrared rays absorbed by the functional groups contained in the organic material, the solvent, and the like. In particular, by emitting infrared rays having a wavelength of 10 μm or less corresponding to the maximum emission intensity, the functional groups contained in the organic material, the solvent, and the like in the fiber sheet 11 absorb the emitted infrared rays more easily, and the solvent contained in the fiber sheet 11 evaporates more easily by heating. Therefore, in the present embodiment, the fiber sheet 11 can be further appropriately dried by using the infrared heater 51.

(modification example)

As a modification of the present embodiment, a press may be provided on the conveyance line 8 in addition to the unwinder 2, the spinning machine 3, the dryer 5, and the winder 6. In this case, the press is configured to press the fiber sheet 11 formed on the surface of the base material 10, and by pressing the fiber sheet 11 with the press, the fiber sheet 11 is compressed, and the density and strength of the fiber sheet 11 can be increased.

As an example of such a press, a press including a pair of press rollers driven by an electric motor or the like can be used. In this case, the fiber sheet 11 and the substrate 10 are sandwiched between a pair of pressing rollers, one of the pressing rollers presses the fiber sheet 11 and the substrate 10 from one side in the thickness direction of the substrate 10, and the other pressing roller presses the fiber sheet 11 and the substrate 10 from the other side in the thickness direction of the substrate 10. In the manufacturing apparatus 1, the press machine may press the fiber sheet 11 formed on the surface of the substrate 10 at least before the substrate 10 is wound up on the winding machine 6.

According to the method and the apparatus for producing a fiber sheet of at least one of the embodiments or examples, the fiber sheet formed on the surface of the base material is dried before winding the base material. Thus, a method and an apparatus for producing a fiber sheet can be provided, which can efficiently dry the fiber sheet while suppressing the amount of solvent contained in the produced fiber sheet to be low.

Several embodiments of the present invention have been described, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.