JP5859217B2 - Polyolefin nanofiber nonwoven fabric manufacturing equipment - Google Patents

Description

  The present invention relates to a polyolefin nanofiber nonwoven fabric manufacturing apparatus.

  The porous polyolefin film can be easily thinned (for example, 20 μm to 40 μm), has high chemical stability and mechanical strength, has an appropriate elongation and elastic modulus, and further has a certain temperature range (for example, 140 ° C. It is widely used, for example, as a separator for lithium ion secondary batteries and capacitors.

  By the way, if the porosity of the porous polyolefin film can be made higher than before, it becomes possible to further increase the ion conductivity of the separator, and further improve the performance of the lithium ion secondary battery and the capacitor. It is considered possible. However, since the porous polyolefin film is produced by the phase separation method or the stretch hole method, it is not easy to further increase the porosity.

  Therefore, it is conceivable to use a nonwoven fabric made of polyolefin nanofibers (hereinafter referred to as a polyolefin nanofiber nonwoven fabric) instead of the porous polyolefin film as a separator for lithium ion secondary batteries or capacitors. Since the polyolefin nanofiber nonwoven fabric is composed of polyolefin nanofibers, it has the same characteristics as the porous polyolefin film described above, and can be considered to have a higher porosity than the porous polyolefin film described above. Because.

  FIG. 8 is a diagram for explaining a method for producing a polyolefin nanofiber nonwoven fabric that can produce such a polyolefin nanofiber nonwoven fabric (see, for example, Patent Document 1). In FIG. 8, reference numeral 932 represents a nozzle, reference numeral 940 represents a collector, reference numeral 950 represents a power supply device, and reference numeral 970 represents a raw material tank.

  As shown in FIG. 8, the conventional method for producing polyolefin nanofibers is to produce a polyolefin nanofiber nonwoven fabric using a polyolefin nanofiber nonwoven fabric production apparatus equipped with a heating device 974. It is heated at 100 ° C. to 100 ° C. and completely dissolved in a multi-component solvent to produce a uniform polymer solution, and electrospinning is performed using the uniform polymer solution to produce a polyolefin nanofiber nonwoven fabric.

  According to the conventional method for producing a polyolefin nanofiber nonwoven fabric, it is possible to perform electrospinning using a uniform polymer solution while using a polyolefin having low solubility in a solvent as a raw material. A polyolefin nanofiber nonwoven fabric having excellent characteristics can be produced.

  The “separator” in the present invention refers to a non-conductive separator. In the present invention, the nanofiber means a fiber having an average diameter of several nm to several thousand nm.

Special table 2009-517554

  However, according to the research of the inventors of the present invention, in the conventional method for producing a polyolefin nanofiber nonwoven fabric, the viscosity of the polymer solution increases with time, and the discharge amount of the polymer solution from the nozzle gradually decreases. As a result, it has been found that there is a problem that it is difficult to stably mass-produce a polyolefin nanofiber nonwoven fabric having uniform quality.

  Such a problem is not a problem that exists only when a polyolefin nanofiber nonwoven fabric is used as a separator, but also a problem that exists when a polyolefin nanofiber nonwoven fabric is used for purposes other than a separator. Moreover, such a problem is not a problem that exists only when producing a polyolefin nanofiber nonwoven fabric containing only polyolefin, but when producing a polyolefin nanofiber nonwoven fabric containing a polymer other than polyolefin in addition to polyolefin. It is a problem that also exists.

  Therefore, the present invention has been made to solve the above-described problems, and is capable of producing a polyolefin nanofiber nonwoven fabric capable of stably mass-producing a polyolefin nanofiber nonwoven fabric having uniform quality. It aims to provide a method. Moreover, it aims at providing the polyolefin nanofiber nonwoven fabric manufacturing apparatus which can implement the manufacturing method of the above polyolefin nanofiber nonwoven fabrics. Furthermore, it aims at providing the separator which consists of a polyolefin nanofiber nonwoven fabric manufactured by the manufacturing method of the above polyolefin nanofiber nonwoven fabrics. In the present invention, the polyolefin nanofiber nonwoven fabric includes not only a nanofiber nonwoven fabric containing only polyolefin but also a nanofiber nonwoven fabric containing a polymer other than polyolefin in addition to polyolefin.

[1] The method for producing a polyolefin nanofiber nonwoven fabric according to the present invention is a polyolefin nanofiber nonwoven fabric production method for producing a polyolefin nanofiber nonwoven fabric by electrospinning, and is within a range of 30 ° C to 100 ° C. A first step of preparing a polymer solution containing polyolefin at a predetermined first temperature; and maintaining the temperature of the polymer solution at a predetermined second temperature in the range of 30 ° C. to 100 ° C. A second step of supplying the nozzle, and discharging the polymer solution from the nozzle while maintaining the nozzle temperature at a predetermined third temperature within a range of 30 ° C. to 100 ° C. And a third step of producing a nonwoven fabric.

  For this reason, according to the method for producing a polyolefin nanofiber nonwoven fabric of the present invention includes the first step of preparing a polymer solution containing polyolefin at a predetermined first temperature in the range of 30 ° C. to 100 ° C. As in the case of the conventional method for producing a polyolefin nanofiber nonwoven fabric, it is possible to perform electrospinning using a uniform polymer solution while using a polyolefin having low solubility in a solvent as a raw material. It becomes possible to produce a polyolefin nanofiber having the above-described excellent characteristics.

  According to the method for producing a polyolefin nanofiber nonwoven fabric of the present invention, the second polymer solution is supplied to the nozzle while maintaining the temperature of the polymer solution at a predetermined second temperature in the range of 30 ° C to 100 ° C. And a third step of electrospinning the polyolefin nanofiber nonwoven fabric by discharging the polymer solution from the nozzle while maintaining the nozzle temperature at a predetermined third temperature in the range of 30 ° C. to 100 ° C. For this reason, the viscosity of the polymer solution does not increase over time, and the discharge rate of the polymer solution from the nozzle does not gradually decrease. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

  The reason why the first temperature is in the range of 30 ° C. to 100 ° C. is that when the first temperature is less than 30 ° C., it may be difficult to completely dissolve the polyolefin in the solvent. When the first temperature exceeds 100 ° C., the amount of evaporation of the solvent becomes too large, and it may be difficult to keep the concentration of polyolefin in the polymer solution constant. From this point of view, it is even more preferable to set the first temperature within the range of 50 ° C to 90 ° C.

  In addition, the second temperature and the third temperature are set within the range of 30 ° C. to 100 ° C., when the second temperature and the third temperature are less than 30 ° C., the polymer solution becomes non-uniform over time. This is because the viscosity of the polymer solution may become too high. When the second temperature and the third temperature exceed 100 ° C., the amount of evaporation of the solvent becomes too large, and the concentration of the polyolefin in the polymer solution becomes constant. This is because it may be difficult to maintain. From this point of view, it is even more preferable that the second temperature and the third temperature be in the range of 50 ° C to 90 ° C.

[2] In the method for producing a polyolefin nanofiber nonwoven fabric of the present invention, the polyolefin nanofiber nonwoven fabric preferably contains only polyolefin as a polymer component.

  As described above, the method for producing a polyolefin nanofiber nonwoven fabric of the present invention is applicable to the production of a polyolefin nanofiber nonwoven fabric containing only polyolefin as a polymer component.

[3] In the method for producing a polyolefin nanofiber nonwoven fabric of the present invention, the polyolefin nanofiber nonwoven fabric preferably contains a polymer other than polyolefin as a polymer component in addition to polyolefin.

  As described above, the method for producing a polyolefin nanofiber nonwoven fabric of the present invention is also applicable to the production of a polyolefin nanofiber nonwoven fabric containing a polymer other than polyolefin as a polymer component.

[4] The polyolefin nanofiber nonwoven fabric manufacturing apparatus of the present invention is a polyolefin nanofiber nonwoven fabric manufacturing apparatus for manufacturing a polyolefin nanofiber nonwoven fabric, and is located at a position facing the collector and the collector. A nozzle unit having a plurality of nozzles for discharging the liquid, a power supply device for applying a high voltage between the collector and the plurality of nozzles, a raw material tank for storing the polymer solution, and from the raw material tank to the nozzle unit And a temperature-retaining device that keeps each of the nozzle unit, the raw material tank, and the polymer solution supply path at a predetermined temperature within a range of 30 ° C to 100 ° C.

  For this reason, according to the polyolefin nanofiber nonwoven fabric production apparatus of the present invention, the heat retaining device that keeps each of the nozzle unit, the raw material tank, and the polymer solution supply path at a predetermined temperature within the range of 30 ° C to 100 ° C. Therefore, the viscosity of the polymer solution does not increase over time, and the discharge rate of the polymer solution from the nozzle does not gradually decrease. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

[5] In the polyolefin nanofiber nonwoven fabric production apparatus of the present invention, it is preferable that the heat retaining device comprises an electric heater.

  By setting it as such a structure, it becomes possible to keep each of a nozzle unit, a raw material tank, and a polymer solution supply path at the predetermined temperature which exists in the range of 30 to 100 degreeC. In this case, each of the temperature of the nozzle unit, the temperature of the raw material tank, and the temperature of the polymer solution supply path can be easily and independently controlled.

[6] In the polyolefin nanofiber nonwoven fabric production apparatus of the present invention, it is preferable that the heat retaining device comprises a hot water circulation device.

  Even with this configuration, each of the nozzle unit, the raw material tank, and the polymer solution supply path can be kept at a predetermined temperature in the range of 30 ° C to 100 ° C. In this case, temporal variations in the temperature of the nozzle unit, the temperature of the raw material tank, and the temperature of the polymer solution supply path can be reduced.

[7] In the polyolefin nanofiber nonwoven fabric production apparatus of the present invention, it is preferable that the heat retaining device comprises a warm air circulation device.

  Even with this configuration, each of the nozzle unit, the raw material tank, and the polymer solution supply path can be kept at a predetermined temperature in the range of 30 ° C to 100 ° C.

[8] In the polyolefin nanofiber nonwoven fabric manufacturing apparatus of the present invention, the power supply device includes one of a positive electrode and a negative electrode connected to the collector, and the other electrode of the positive electrode and the negative electrode is the above-mentioned It is preferable that the power supply device is connected to the collector and the nozzle unit so that the potential of the other electrode becomes a ground potential while being connected to the nozzle unit.

  By adopting such a configuration, all of the “polymer solution before being discharged from the nozzle”, the raw material tank, and the polymer solution supply path (for example, piping, feed pump, etc.) including the nozzle unit become the ground potential. Therefore, it is not necessary to make the raw material tank and the polymer solution supply path have high withstand voltage specifications. Therefore, the mechanism of the polyolefin nanofiber nonwoven fabric manufacturing apparatus does not become complicated due to making the raw material tank and the polymer solution supply path have high withstand voltage specifications.

  In addition, it is not desirable because a high voltage is applied to a collector that can have a relatively simple shape and structure, and a nozzle unit having a relatively complicated shape and structure can be electrospun while grounded. It becomes difficult to cause discharge and voltage drop, and it becomes possible to always perform electrospinning under stable conditions.

[9] In the polyolefin nanofiber nonwoven fabric manufacturing apparatus of the present invention, the electrospinning apparatus preferably has a plurality of upward nozzles that discharge the polymer solution upward from the discharge ports as the plurality of nozzles.

  By adopting such a configuration, a droplet phenomenon (a lump of polymer solution that has not been spun from a downward nozzle remains as it is in the case of a conventional polyolefin nanofiber nonwoven fabric manufacturing apparatus using a downward nozzle. And the like, and a high-quality polyolefin nanofiber nonwoven fabric can be produced.

[10] In the polyolefin nanofiber nonwoven fabric manufacturing apparatus of the present invention, the second nozzle unit having a plurality of nozzles that are located at positions facing the collector and that discharge a second polymer solution that does not contain polyolefin, and the second A second raw material tank for storing a polymer solution, and a second polymer solution supply path from the second raw material tank to the second nozzle unit, wherein the heat retaining device includes the nozzle unit, the second nozzle unit, Among the raw material tank, the second raw material tank, the polymer solution supply path, and the second polymer solution supply path, only the nozzle unit, the raw material tank, and the polymer solution supply path are configured to be kept warm. preferable.

  With such a configuration, for the second polymer solution capable of producing the polymer solution at room temperature, the polymer solution is produced, the polymer solution is supplied to the nozzle, or the polymer solution is discharged from the nozzle. This makes it possible to carry out the process of producing a nanofiber nonwoven fabric at room temperature, so that it is possible to produce a polyolefin nanofiber nonwoven fabric and a nanofiber nonwoven fabric not containing polyolefin by appropriate methods. .

  The polyolefin nanofiber nonwoven fabric produced by the polyolefin nanofiber nonwoven fabric production method or polyolefin nanofiber nonwoven fabric production apparatus of the present invention includes secondary battery separators, capacitor separators, various catalyst carriers, various sensor materials, etc. Industrial materials such as electronic / mechanical materials, wiping cloths, filters, medical materials such as regenerative medical materials, biomedical materials, medical MEMS materials, biosensor materials, clothing such as high-functional and high-sensitivity textiles, health care, skin care, etc. It can be used for a wide range of other beauty related products.

[11] The separator of the present invention is characterized by comprising a polyolefin nanofiber nonwoven fabric produced by the method for producing a polyolefin nanofiber nonwoven fabric of the present invention.

  Therefore, the separator of the present invention can be easily thinned (for example, 20 μm to 40 μm), has high chemical stability and mechanical strength, has an appropriate elongation and elastic modulus, and further has a certain temperature range ( For example, it is an excellent separator having characteristics of melting and closing pores at 140 ° C. to 160 ° C. to cut off current, and having a high porosity and consequently high ionic conductivity.

[12] The separator of the present invention includes a polyolefin nanofiber nonwoven fabric produced by the method for producing a polyolefin nanofiber nonwoven fabric of the present invention.

  Therefore, the separator of the present invention can be easily thinned (for example, 20 μm to 40 μm), has high chemical stability and mechanical strength, has an appropriate elongation and elastic modulus, and further has a certain temperature range ( For example, the separator has a characteristic of blocking current by melting and closing at 140 ° C. to 160 ° C., and has a high porosity and thus high ion conductivity.

It is sectional drawing of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 which concerns on Embodiment 1. FIG. It is a figure which shows a mode that the separator 200 is manufactured with the manufacturing method of the polyolefin nanofiber nonwoven fabric which concerns on Embodiment 1. FIG. It is sectional drawing of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 2 which concerns on Embodiment 2. FIG. It is sectional drawing of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 3 which concerns on Embodiment 3. FIG. It is sectional drawing of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 4 which concerns on Embodiment 4. FIG. It is sectional drawing of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 5 which concerns on Embodiment 5. FIG. It is a figure which shows a mode that the separator 202 is manufactured by the manufacturing method of the polyolefin nanofiber nonwoven fabric concerning Embodiment 5. FIG. It is a figure shown in order to demonstrate the conventional polyolefin nanofiber nonwoven fabric manufacturing apparatus 900. FIG.

  Hereinafter, a method for producing a polyolefin nanofiber nonwoven fabric, a polyolefin nanofiber nonwoven fabric production apparatus, and a separator according to the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
1. Polyolefin Nanofiber Nonwoven Fabric Manufacturing Apparatus FIG. 1 is a cross-sectional view of a polyolefin nanofiber nonwoven fabric fabrication apparatus 1 according to the first embodiment. As shown in FIG. 1, the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to Embodiment 1 includes a transport device 10 that transports a long sheet W, an electrospinning device 20, a raw material tank 70, and a polymer solution supply path 80. And a heat retaining device 100.

  The conveying device 10 includes a feeding roller 11 that feeds out the long sheet W, a winding roller 12 that winds up the long sheet W, and auxiliary rollers 13 and 14 that are positioned between the feeding roller 11 and the winding roller 12. The feeding roller 11 and the take-up roller 12 are configured to be rotated by a drive motor (not shown).

  As shown in FIG. 1, the electrospinning apparatus 20 deposits nanofibers containing polyolefin on a long sheet W from below. Hereinafter, the configuration of the electrospinning apparatus 20 will be described in detail.

  As shown in FIG. 1, the electrospinning device 20 includes a housing 44 made of a conductor, a nozzle unit 30 having a plurality of upward nozzles 32, a collector 40, a power supply device 50, and an auxiliary belt device 60. .

  Although the nozzle unit 30 having various sizes and shapes can be used in the separator manufacturing apparatus of the present invention, the nozzle unit 30 has a rectangular shape (a square having a side of 0.5 m to 3 m when viewed from the upper surface. It has a block-like shape with a visible size.

  The plurality of upward nozzles 32 are nozzles that discharge a polymer solution supplied from a polymer solution supply path 80 described later upward from the discharge port. As a material constituting the plurality of upward nozzles 32, a conductor can be used, and for example, copper, stainless steel, aluminum, or the like can be used.

  The plurality of upward nozzles 32 are arranged at a pitch of 1.5 cm to 6.0 cm, for example. The number of the plurality of upward nozzles 32 can be, for example, 36 (6 × 6 when arranged in the same vertical and horizontal directions) to 21904 (148 × 148 when arranged in the same vertical and horizontal directions).

  The collector 40 is disposed above the nozzle unit 30. The collector 40 is made of a conductor and is attached to the housing 44 via an insulating member 42 as shown in FIG.

  The power supply device 50 applies a high voltage between the plurality of upward nozzles 32 and the collector 40. The positive electrode of the power supply device 50 is connected to the collector 40, and the negative electrode of the power supply device 50 is connected to the nozzle unit 30 and the housing 44.

  The auxiliary belt device 60 includes an auxiliary belt 62 that rotates in synchronization with the conveying speed of the long sheet W, and five auxiliary belt rollers 64 that assist the rotation of the auxiliary belt 62. Of the five auxiliary belt rollers 64, one or more auxiliary belt rollers are drive rollers, and the remaining auxiliary belt rollers are driven rollers. Since the auxiliary belt 62 is disposed between the collector 40 and the long sheet W, the long sheet W is smoothly conveyed without being attracted to the collector 40 to which a positive high voltage is applied. become.

  The raw material tank 70 stores a polymer solution containing polyolefin which is a raw material for polyolefin nanofibers. The raw material tank 70 has a stirring device 72 for preventing separation and coagulation of the polymer solution. A pipe 82 of a polymer solution path device 80 is connected to the raw material tank 70.

  The polymer solution supply path 80 includes a pipe 82 through which the polymer solution passes and a valve 84 that controls the supply operation, and supplies the polymer solution stored in the raw material tank 70 to the nozzle unit 30.

  As shown in FIG. 1, the heat retaining device 100 includes electric heaters 102, 104, and 106. The electric heater 102 is installed on the side surface side of the raw material tank 70. By controlling the output of the electric heater 102, the raw material tank 70 is kept at a predetermined first temperature of 30 ° C to 100 ° C. The electric heater 104 is installed so as to cover the polymer solution supply path 80. By controlling the output of the electric heater 104, the polymer solution supply path 80 is kept at a predetermined second temperature of 30 ° C to 100 ° C. The electric heater 106 is installed below the nozzle unit 30. By controlling the output of the electric heater 106, the nozzle unit 30 is kept at a predetermined third temperature of 30 ° C to 100 ° C. The heat retaining device 100 includes a heat retaining jacket that covers the raw material tank 70, the polymer solution supply path 80, and the nozzle unit 30.

2. Production Method of Polyolefin Nanofiber Nonwoven Fabric FIG. 2 is a diagram showing how the separator 200 is produced by the polyolefin nanofiber nonwoven fabric production method according to the first embodiment.
The method for producing a polyolefin nanofiber nonwoven fabric according to Embodiment 1 includes the following first to third steps. Hereinafter, along with each process, the manufacturing method of the polyolefin nanofiber nonwoven fabric which concerns on Embodiment 1 is demonstrated.

1. First Process The first process is a process for preparing a polymer solution containing polyolefin at a predetermined first temperature in the range of 30 ° C to 100 ° C. Specifically, a polymer material containing polyolefin and a multi-component solvent are charged into the raw material tank 70, and the raw material tank 70 is kept at a predetermined first temperature within a range of 30 ° C to 100 ° C by the electric heater 102. The polymer material is completely dissolved in the multi-component solvent to prepare a uniform polymer solution having a low viscosity. The first temperature is set according to the type and amount of the polymer material and the solvent used.

2. Second Process The second process is a process of supplying the polymer solution to the plurality of upward nozzles 32 while maintaining the temperature of the polymer solution at a predetermined second temperature in the range of 30 ° C to 100 ° C. Specifically, the polymer solution prepared in the first step is kept in the polymer solution supply path 80 while the polymer solution supply path 80 is kept at a predetermined second temperature within the range of 30 ° C. to 100 ° C. by the electric heater 104. Is supplied to the nozzle unit 30. The second temperature is set according to the type and amount of the polymer material and the solvent used.

3. The electrospinning process The third process is a nanofiber nonwoven fabric made of polyolefin by discharging the polymer solution from the nozzle while maintaining the temperature of the plurality of upward nozzles 32 at a predetermined third temperature in the range of 30 ° C. to 100 ° C. Is the process of manufacturing. Specifically, first, the long sheet W is set on the conveyance device 10, and then the long sheet W is conveyed from the feeding roller 11 toward the take-up roller 12 at a predetermined conveyance speed. Thereafter, the polymer solution supplied to the nozzle unit 30 is discharged from the outlets of the plurality of upward nozzles 32 in a state where the nozzle unit 30 is kept at a predetermined third temperature within a range of 30 ° C. to 100 ° C. by the electric heater 106. The sheet is discharged upward toward the long sheet W. The third heat retention temperature is set according to the type and amount of the polymer material and the solvent used.

  Thereby, as shown in FIG. 2, polyolefin nanofibers are deposited on one surface of the long sheet W, and the polyolefin nanofiber nonwoven fabric 210 can be produced on one surface of the long sheet W. (See FIG. 2A and FIG. 2B.) The produced polyolefin nanofiber nonwoven fabric 210 can be used as it is as the separator 200 (see FIG. 2C).

  The spinning conditions in the method for producing a polyolefin nanofiber nonwoven fabric according to Embodiment 1 will be exemplified below.

  Polyolefins include polyethylene, polypropylene, poly-1-butene (PB), poly-1-pentene, poly-1-hexene, poly (3-methyl-1-butene), and poly (4-methyl-1-pentene). (PMP), poly (4-methyl-1-hexene), poly (5-methyl-1-heptene) and the like can be used.

  Solvents include HFIP, dichloromethane, dimethylacetamide, chloroform, xylene, methylcyclohexane, acetone, chloroform, ethanol, isopropanol, methanol, toluene, tetrahydrofuran, water, benzene, benzyl alcohol, 1,4-dioxane, propanol, carbon tetrachloride. , Cyclohexane, cyclohexanone, phenol, pyridine, trichloroethane, acetic acid; N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N, N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), Ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), acetonitrile (AN), N-methylmorpholine-N-oxide, butylene carbonate (BC), 1,4-butyrolacto (BL), diethyl carbonate (DEC), diethyl ether (DEE), 1,2-dimethoxyethane (DME), 1,3-dimethyl-2-imidazolidinone (DMI), 1,3-dioxolane (DOL), Ethyl methyl carbonate (EMC), methyl formate (MF), 3-methyloxazolidine-2-one (MO), methyl propionate (MP), 2-methyltetrahydrofuran (MeTHF) or sulfolane (SL) can be used.

  As the long sheet W, a nonwoven fabric, a woven fabric, a knitted fabric, a film, a sheet, paper, or the like made of various materials can be used. The long sheet W may have a thickness of, for example, 5 μm to 500 μm. The length of the long sheet W can be, for example, 10 m to 10 km.

  A conveyance speed can be set to 0.2 m / min-100 m / min, for example. The voltage applied to the collector 40 and the nozzle unit 30 can be set to 10 kV to 80 kV.

  The temperature of the spinning area can be set to 10 ° C. to 40 ° C., for example, except in the vicinity of the nozzle unit 30. Moreover, the humidity of a spinning area can be set to 20%-60%, for example.

3. Effect of polyolefin nanofiber production method According to the polyolefin nanofiber nonwoven fabric production method according to the first embodiment, a polymer solution containing a polyolefin at a predetermined first temperature within a range of 30 ° C to 100 ° C. Since the first process is included, as in the case of the conventional method for producing a polyolefin nanofiber nonwoven fabric, an electrospinning is performed using a uniform polymer solution while using a polyolefin originally having low solubility in a solvent as a raw material. This makes it possible to produce a polyolefin nanofiber nonwoven fabric having the above-described excellent characteristics.

  In addition, according to the method for producing a polyolefin nanofiber nonwoven fabric according to Embodiment 1, a plurality of upward nozzles are provided for a polymer solution while maintaining the temperature of the polymer solution at a predetermined second temperature in the range of 30 ° C to 100 ° C. The second step of supplying to the nozzle 32 and the polyolefin nanofiber nonwoven fabric by discharging the polymer solution from the nozzle while maintaining the temperature of the plurality of upward nozzles 32 at a predetermined third temperature in the range of 30 ° C. to 100 ° C. And the third process of electrospinning, the viscosity of the polymer solution does not increase over time, and the discharge rate of the polymer solution from the nozzle does not gradually decrease. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

4). Effect of polyolefin nanofiber production apparatus According to polyolefin nanofiber nonwoven fabric production apparatus 1 according to Embodiment 1, each of nozzle unit 30, raw material tank 70 and polymer solution supply path 80 is within a range of 30 ° C to 100 ° C. Since the heat retaining device 100 that retains the temperature at a predetermined temperature is provided, the viscosity of the polymer solution does not increase even after a lapse of time, and the discharge amount of the polymer solution from the nozzle does not gradually decrease. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

  Moreover, according to the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment, since the heat retaining device 100 is composed of an electric heater, each of the temperature of the nozzle unit 30, the temperature of the raw material tank 70, and the temperature of the polymer solution supply path 80. Can be easily and independently controlled.

  Further, according to the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to Embodiment 1, the positive electrode of the power supply device 50 is connected to the collector 40, the negative electrode is connected to the nozzle unit 30, and the potential of the negative electrode is grounded. Since the power supply device 50 is connected to the collector 40 and the nozzle unit 30 so as to be at a potential, the nozzle unit 30 and the “polymer solution before being discharged from the upward nozzle 32”, the raw material tank 70, the polymer solution Since all of the supply paths 80 (for example, piping and feed pumps) are at ground potential, the raw material tank 70 and the polymer solution supply path 80 do not need to have a high withstand voltage specification. Therefore, the mechanism of the polyolefin nanofiber nonwoven fabric manufacturing apparatus does not become complicated due to the material tank 70 and the polymer solution supply path 80 having high withstand voltage specifications.

  In addition, since a high voltage is applied to the collector 40 that can have a relatively simple shape and structure, and the nozzle unit 30 having a relatively complicated shape and structure can be electrospun while being grounded, Undesirable discharge and voltage drop are unlikely to occur, and electrospinning can always be performed under stable conditions.

  In the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment, the electrospinning apparatus 20 has a plurality of upward nozzles for discharging the polymer solution upward from the discharge ports as the plurality of upward nozzles 32, so that the conventional downward direction A droplet phenomenon (a phenomenon in which a lump of polymer solution that has not been spun from a downward nozzle adheres to a base material layer or the like) as seen in the polyolefin nanofiber nonwoven fabric manufacturing apparatus 900 using a nozzle may occur. Therefore, it is possible to produce a high-quality polyolefin nanofiber nonwoven fabric.

[Embodiment 2]
FIG. 3 is a cross-sectional view of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 2 according to the second embodiment.
The polyolefin nanofiber nonwoven fabric manufacturing apparatus 2 according to the second embodiment basically has the same configuration as the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment, but the configuration of the heat retention apparatus is related to the first embodiment. It differs from the case of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1. That is, as shown in FIG. 3, the polyolefin nanofiber nonwoven fabric manufacturing apparatus 2 according to Embodiment 2 includes a heat retaining device 110 composed of a hot water circulation device instead of the heat retaining device 100 composed of the electric heaters 102, 104, and 106. .

  The heat retaining device 110 includes a hot water tank 112, a heater 114, and a hot water pipe 116. The hot water tank 112 stores the hot water heated by the heater 114. In the course of circulating hot water through the hot water pipe 116, the raw material tank 70, the polymer solution supply path 80 and the nozzle unit 30 are warmed, whereby the raw material tank 70, the polymer solution supply path 80 and the nozzle unit 30 are 30 ° C. to 100 ° C. The temperature is kept at a predetermined first temperature, second temperature, and third temperature between 0 ° C. and 1 ° C., respectively.

  As described above, the polyolefin nanofiber nonwoven fabric manufacturing apparatus 2 according to the second embodiment differs from the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment in the configuration of the heat retaining device, but the nozzle unit 30 and the raw material tank 70. In addition, the temperature of the polymer solution supply path 80 is maintained, so that the viscosity of the polymer solution may increase over time as in the case of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment. The discharge amount of the polymer solution from the nozzle is not gradually reduced. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

  In addition, since the polyolefin nanofiber nonwoven fabric manufacturing apparatus 2 according to Embodiment 2 has the same configuration as that of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to Embodiment 1 except for the configuration of the heat retention apparatus, It has a corresponding effect among the effects which the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 has.

[Embodiment 3]
FIG. 4 is a cross-sectional view of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 3 according to the third embodiment.
The polyolefin nanofiber nonwoven fabric manufacturing apparatus 3 according to the third embodiment basically has the same configuration as the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment, but the configuration of the heat retaining apparatus is related to the first embodiment. It differs from the case of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1. That is, as shown in FIG. 4, the polyolefin nanofiber nonwoven fabric manufacturing apparatus 3 according to the third embodiment includes a heat retaining device 120 composed of a hot air circulation device instead of the heat retaining device 100 composed of the electric heaters 102, 104, and 106. Prepare.

The heat retaining device 120 includes a warm air generator 122 and a warm air supply path 124.
The heat retaining device 120 is a process in which the hot air generated by the hot air generator 122 circulates through the raw material tank 70, the polymer solution supply path 80, and the hot air supply path 124 covering the nozzle unit 30. The path 80 and the nozzle unit 30 are warmed, whereby the raw material tank 70, the polymer solution supply path 80, and the nozzle unit 30 are kept at a predetermined first temperature, second temperature, and third temperature between 30 ° C. and 100 ° C., respectively. Is done.

  As described above, the polyolefin nanofiber nonwoven fabric manufacturing apparatus 3 according to the third embodiment is different from the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment in the configuration of the heat retaining device, but the nozzle unit 30 and the raw material tank 70. In addition, since the temperature maintaining device 120 for maintaining the temperature of the polymer solution supply path 80 is provided, the viscosity of the polymer solution does not increase even when time passes, as in the case of the nanofiber manufacturing apparatus 1 according to the first embodiment. The amount of the polymer solution discharged from the liquid does not gradually decrease. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

  In addition, since the polyolefin nanofiber nonwoven fabric manufacturing apparatus 3 according to Embodiment 3 has the same configuration as that of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to Embodiment 1 except for the configuration of the heat retention apparatus, It has a corresponding effect among the effects which the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 has.

[Embodiment 4]
FIG. 5 is a cross-sectional view of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 4 according to the fourth embodiment.
The polyolefin nanofiber nonwoven fabric manufacturing apparatus 4 according to the fourth embodiment basically has the same configuration as the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment, but the arrangement position of the raw material tank is the same as that of the first embodiment. It differs from the case of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 concerned. That is, in the polyolefin nanofiber nonwoven fabric manufacturing apparatus 4 according to the fourth embodiment, the raw material tank 70 is arranged in the space below the nozzle unit 30 as shown in FIG. Correspondingly, the polymer solution supply path 80 and the heat retaining device 130 are arranged in a space below the nozzle unit 80. The heat retaining device 130 includes electric heaters 132 and 134.

  Thus, the polyolefin nanofiber nonwoven fabric manufacturing apparatus 4 according to the fourth embodiment is different from the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment in the coordination position of the raw material tank 70, but the nozzle unit 30, Since the heat retention device 130 for keeping the raw material tank 70 and the polymer solution supply path 80 is provided, as in the case of the polyolefin nanofiber nonwoven fabric production device 1 according to the first embodiment, the viscosity of the polymer solution is high over time. The discharge amount of the polymer solution from the nozzle does not gradually decrease. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

  In addition, since the polyolefin nanofiber nonwoven fabric manufacturing apparatus 4 according to the fourth embodiment has the same configuration as that of the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment except for the arrangement position of the raw material tank 70, The polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment has a corresponding effect among the effects.

[Embodiment 5]
FIG. 6 is a view for explaining the polyolefin nanofiber nonwoven fabric manufacturing apparatus 5 according to the fifth embodiment. FIG. 7 is a diagram illustrating a state where the separator 202 is manufactured by the method for manufacturing a polyolefin nanofiber nonwoven fabric according to the fifth embodiment.

  The polyolefin nanofiber nonwoven fabric production apparatus 5 according to Embodiment 5 has basically the same configuration as the polyolefin nanofiber nonwoven fabric production apparatus 1 according to Embodiment 1, but includes polyolefin as shown in FIG. A second nozzle unit 30a having a plurality of nozzles 32a for discharging the second polymer solution, a second raw material tank 70a for storing the second polymer solution, and the second raw material tank 70a to the second nozzle unit 30a. The polyolefin nanoparticle according to the first embodiment in that the second polymer solution supply path 80a and the heat retaining device 130 are configured to heat only the nozzle unit 30, the raw material tank 70, and the polymer solution supply path 80. Different from the fiber nonwoven fabric manufacturing apparatus 1.

  For this reason, according to the polyolefin nanofiber nonwoven fabric manufacturing apparatus 5 according to the fifth embodiment, the polyolefin nanofiber nonwoven fabric 210 is produced on the long sheet W by discharging the polymer solution containing the polyolefin from the nozzle 32 (FIG. 7 (a) and FIG. 7 (b)), and then, by discharging a polymer solution containing no polyolefin from the nozzle 32a to produce a nanofiber nonwoven fabric 220 containing no polyolefin, the polyolefin nanofiber nonwoven fabric 210 and A nanofiber nonwoven fabric laminated with a nanofiber nonwoven fabric 220 containing no polyolefin can be produced (see FIG. 7C). The produced “nanofiber nonwoven fabric in which a polyolefin nanofiber nonwoven fabric and a polyolefin-free nanofiber nonwoven fabric are laminated” can be used as the separator 202 as it is (see FIG. 7D).

  As described above, the polyolefin nanofiber nonwoven fabric manufacturing apparatus 5 according to Embodiment 5 stores the second nozzle unit 30a having the plurality of nozzles 32a for discharging the second polymer solution not containing polyolefin, and the second polymer solution. The point provided with the second raw material tank 70a and the second polymer solution supply path 80a from the second raw material tank 70a to the second nozzle unit 30a and the heat retaining device 130 are only the nozzle unit 30, the raw material tank 70 and the polymer solution supply path 80. Is different from the polyolefin nanofiber nonwoven fabric manufacturing apparatus 1 according to the first embodiment in that the nozzle unit 30, the raw material tank 70, and the polymer solution supply path 80 are kept warm. In order to provide, similarly to the case of the nanofiber manufacturing apparatus 1 according to the first embodiment, When electrospinning using a polymer solution containing reolefin, the viscosity of the polymer solution does not increase over time, and the discharge rate of the polymer solution from the nozzle gradually decreases. Also disappear. For this reason, it becomes possible to stably mass-produce polyolefin nanofiber nonwoven fabric having uniform quality.

  Moreover, according to the polyolefin nanofiber nonwoven fabric manufacturing apparatus 5 according to Embodiment 5, a nanofiber nonwoven fabric in which a polyolefin nanofiber nonwoven fabric and a nanofiber nonwoven fabric not containing polyolefin are laminated can be manufactured.

  As mentioned above, although this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment, It is possible to implement in a various aspect in the range which does not deviate from the meaning. For example, the following modifications are possible.

(1) In Embodiment 1 described above, the raw material tank 70, the polymer solution supply path 80, and the nozzle unit 30 are each kept warm using separate electric heaters 102, 104, and 106, but the present invention is limited to this. Is not to be done. For example, the raw material tank, the polymer solution supply path, and the nozzle unit may be covered with one heat insulation jacket and the entire space in the heat insulation jacket may be kept warm using one electric heater.

(2) In each of the above embodiments, the polyolefin nanofiber nonwoven fabric manufacturing apparatus of the present invention has been described using an upward electrospinning apparatus having an upward nozzle, but the present invention is not limited to this. For example, the present invention can be applied to a polyolefin nanofiber nonwoven fabric manufacturing apparatus including a downward electrospinning apparatus having a downward nozzle and a lateral electrospinning apparatus having a lateral nozzle.

DESCRIPTION OF SYMBOLS 1,2,3,4,5 ... Polyolefin nanofiber nonwoven fabric manufacturing apparatus, 10 ... Conveying device, 11 ... Feeding roller, 12 ... Winding roller, 13, 14 ... Auxiliary roller, 20, 20a, 20b ... Electrospinning device , 30, 30a ... Nozzle unit, 32, 32a, 932 ... Nozzle, 40, 940 ... Collector, 42 ... Insulating member, 44 ... Housing, 50, 950 ... Power supply, 60 ... Auxiliary belt device, 62 ... Auxiliary belt, 64 ... roller for auxiliary belt, 70, 970 ... raw material tank, 70a ... second raw material tank, 72, 72a ... stirrer, 80 ... polymer solution supply path, 80a ... second polymer solution supply path, 82, 82a ... pipe, 84, 84a ... Valve, 100, 110, 120, 130 ... Insulation device, 102, 104, 106, 132, 134 ... Electric heater 112 ... hot water tank, 114 ... heater, 116 ... hot water pipe, 122 ... hot air generating device, 124 ... hot air supply path, 974 ... heater, W ... long sheet

Claims (3)

A polyolefin nanofiber nonwoven fabric manufacturing apparatus for manufacturing a polyolefin nanofiber nonwoven fabric,
A collector,
A nozzle unit having a plurality of nozzles that are located at positions facing the collector and that discharge the polymer solution;
A power supply device that applies a high voltage between the collector and the plurality of nozzles;
A raw material tank for storing the polymer solution;
A polymer solution supply path from the raw material tank to the nozzle unit;
A heat retention device for retaining each of the nozzle unit, the raw material tank, and the polymer solution supply path at a predetermined temperature within a range of 30 ° C to 100 ° C ;
The heat retaining device comprises an electric heater,
In the power supply device, one of a positive electrode and a negative electrode is connected to the collector, the other of the positive electrode and the negative electrode is connected to the nozzle unit, and the potential of the other electrode is a ground potential. The polyolefin nanofiber nonwoven fabric manufacturing apparatus , wherein the power supply device is connected to the collector and the nozzle unit . In the polyolefin nanofiber nonwoven fabric manufacturing apparatus according to claim 1 ,
The said electrospinning apparatus has a plurality of upward nozzles which discharge the said polymer solution upward from a discharge port as said several nozzle, The polyolefin nanofiber nonwoven fabric manufacturing apparatus characterized by the above-mentioned . In the polyolefin nanofiber nonwoven fabric manufacturing apparatus according to claim 1 or 2 ,
A second nozzle unit having a plurality of nozzles that are located at positions facing the collector and that discharge a second polymer solution that does not contain polyolefin;
A second raw material tank for storing the second polymer solution;
A second polymer solution supply path from the second raw material tank to the second nozzle unit,
The heat retaining device includes, among the nozzle unit, the second nozzle unit, the raw material tank, the second raw material tank, the polymer solution supply path, and the second polymer solution supply path, the nozzle unit, the raw material tank, and the A polyolefin nanofiber nonwoven fabric manufacturing apparatus characterized in that only the polymer solution supply path is kept warm.

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