OA20432A - Nanofiber manufacturing equipment and nanofiber manufacturing method - Google Patents

Abstract

To produce nanofiber sheets that are homogeneous over the entire surface of the sheets. Furthermore, to prevent a polymer solution that fails to become nanofibers in a fiber generation device from turning into droplets or small polymer masses that fly straight toward a nanofiber collection device, thereby avoiding directly hitting a nanofiber collecting surface of the nanofiber collection device. [SOLUTION] A nanofiber production apparatus provided with: a nanofiber generation device equipped with a liquid discharge nozzle for discharging a polymer solution in which a polymer has been dissolved in a solvent, and a hot air discharge nozzle for discharging a high-temperature, high-speed gas at high pressure; and a collection device for suctioning and collecting nanofibers generated by the nanofiber generation device. A flow path suppression means is provided between the nanofiber generation device and the nanofiber collection device, said flow path suppression means causing the nanofibers generated by the nanofiber generation device to float so that the flow of nanofibers generated by the nanofiber generation device do not directly fly straight into the nanofiber collection device.

Description

NANOFIBER MANUFACTURING EQUIPMENT AND NANOFIBER MANUFACTURING METHOD

Technical field

[0001]

The présent invention relates to a nanofîber manufacturing apparatus and a nanofiber manufacturing method for manufacturing nanofibers from a polymer solution. In particular, the présent invention relates to a nanofiber manufacturing apparatus and a nanofiber manufacturing method for manufacturing nanofibers from a polymer solution in which a raw material polymer is dissolved in a solvent. More specifically, the présent invention relates to a nanofiber sheet manufacturing apparatus and a nanofiber sheet manufacturing method for manufacturing a homogeneous nanofiber sheet from a polymer solution in which a raw material polymer is dissolved in a solvent.

Background technology

[0002]

In the présent spécification, the term nanofiber is a fine-diameter fiber having an average fiber diameter of several nanometers to several hundreds of nanometers, and includes an aggregate thereof, which is an aggregate. Then, the fiber diameters are appropriately distributed.

Further, in the présent spécification, specifically, a melt obtained by melting a raw material polymer by heat or a solution obtained by dissolving a raw material polymer in a volatile solvent is used as a raw material, but it means a solution containing both of them. In this case, the term solution or polymer solution is simply used.

[0003]

Nanofibers with a small fiber diameter hâve attracted attention in recent years, and their use is widespread in a wide range of technical fields such as medical fields, automobile fields, building materials fields, and oil adsorbent fields. As a method for producing this nanofiber, a method of 1 producing by discharging a molten liquid obtained by melting a raw material polymer with heat into a heat jet gas stream (melt spinning method) and a method of dissolving the raw material polymer with a volatile solvent are used. A method (dry spinning method) of producing by discharging to a hot jet gas stream is generally known. Further, a method of producing nanoftbers by discharging a raw material polymer in a solution (wet spinning method) is also known, but it is not a subject of the présent invention.

[0004]

Here, the melt spinning method and the dry spinning method are common in that nanofibers are manufactured by discharging a liquid resin solution toward a hot jet gas flow. Patent Documents 1 and 2 describe an apparatus for producing nanofibers with a melt obtained by melting a raw material polymer with heat, and Patent Documents 3 and 4 describe a solution obtained by dissolving a raw material polymer with a solvent. A device for manufacturing nanofibers is described.

[0005]

The fiber diameter of nanofibers produced by melting the raw material polymer with heat is about several hundred nanometers to 10 micrometer, but in the method of producing the raw material polymer with a solution dissolved in a volatile solvent, the solution is It is possible to produce finer nanofibers having low viscosity and having a fiber diameter of about several tens of nanometers to several micrometer. Therefore, when producing nanofibers having a finer fiber diameter, a method of producing nanofibers with a solution (dry spinning method) is adopted. [0006]

Patent Documents 3 and 4 disclose a technique for producing a raw material polymer in a solution dissolved in a volatile solvent, and Patent Document 3 uses a high voltage called a charge-induced spinning method (or an electric field spinning method). Patent Document 4 discloses a different method of spinning without applying a high voltage.

[0007]

Patent Document 3 has an object of providing a method and apparatus for producing a nanofiber non-woven fabric capable of efficiently producing a uniform nanofiber non-woven fabric. Then, when the blower and the blower are operated, a voltage is applied between the nozzle in the housing and the collecting material, and the polymer solution is discharged from the nozzle, the polymer solution is discharged from the nozzle as a thin linear body. An electrostatic explosion occurs and is explosively stretched to efficiently produce nanofibers made of polymers with a submicron diameter.

[0008]

More specifically, during the production of the non-woven fabric, the blower and the blower are operated so that the air volume of the blower is 30% or more of the air volume of the blower, so that the fluffing of the nanofibers deposited on the collecting material can be suppressed. It is said that it is possible to reduce the unevenness of the déposition thickness of nanofibers on the collecter material. In this way, by setting the air volume of the blower to 100% or less of the air volume of the exhaust fan, it is possible to prevent the air volume on the nozzle side of the collecting material from becoming excessive, and it is possible to prevent the nanofibers from scattering.

[0009]

In Patent Document 4, a guide box is provided on the downstream side of the nanofiber generator and on the upstream side of the collection device to help generate an air flow from the nanofiber generator toward the suction box when the suction box is activated. At the same time, an apparatus for preventing nanofibers produced by the nanofiber generator from scattering to the surroundings is disclosed. On the other hand, when the guide box is not provided, the high-speed hightemperature air ejected from the air nozzle of the nanofiber generator entrains the surrounding air, and the air flow becomes unstable. On the other hand, by using the guide box, a stable air flow can be generated. Therefore, it is said that small-diameter nanofibers can be stably produced.

Prior art literature

Patent documents

[0010]

Patent Document 1 : Japanese Unexamined Patent Publication No. 2016-183435

Patent Document 2: Japanese Unexamined Patent Publication No. 2016-0233399

Patent Document 3: Japanese Unexamined Patent Publication No. 2012-127008

Patent Document 4: Re-table 2015-145880A

Outline of the invention

Problems to be solved by the invention

[0011]

The conventional nanofiber manufacturing method aims to collect nanofibers by forming a stable air flow from the nanofiber generator to the collection device on the downstream side. Even if nanofibers are collected by a collecting device, it is difficult to collect nanofibers having a uniform fiber diameter distribution.

[0012]

In the présent invention, instead of transporting nanofibers from the nanofiber generator on an air flow and collecting them as in the prior art, the transport flow of the nanofibers generated by the nanofiber generator is suppressed and the housing is received. The purpose is to obtain a homogeneous nanofiber sheet by freely floating in the body, sucking the gas in the housing, and collecting the floating nanofibers with a collecting device. In this way, the fine particles of the polymer solution that hâve failed to become the desired nanofiber libers by the nanofiber generator become droplets or small polymer agglomérâtes on the air stream to capture the nanofibers of the collector. It is possible to prevent the nanofibers that fly to the collecting surface and hit the collected nanofibers directly. That is, an object of the présent invention is to provide a nanofiber manufacturing apparatus and a nanofiber manufacturing method, which are provided with means for suppressing damage to collected nanofibers. This problem is even more important because it greatly affects the homogeneity of the finished product when manufacturing the sheet-shaped 4 nanofiber manufacturing apparatus and manufacturing method using the fiat plate-shaped collecting surface.

Means to solve problems

[0013]

The nanofiber manufacturing apparatus of the présent invention includes a housing, a nanofiber generating device provided in the housing, and a nanofiber collecting device that collects nanofibers discharged and generated by the nanofiber generating device. It is a nanofiber manufacturing device equipped with

The nanofiber generator has a solution discharge nozzle for discharging a raw material polymer solution and a hot air discharge nozzle for discharging a high-pressure high-temperature highspeed gas.

The nanofiber collecting device has a nanofiber collecting surface formed on one surface of the housing and a suction device that sucks gas in the housing from the back surface side of the nanofiber collecting surface.

On the downstream side of the nanofiber discharge flow generated by the nanofiber generator, at least one flow path suppressing means for suppressing the nanofiber discharge flow linearly directed from the nanofiber generator to the nanofiber collection surface. It is characterized by having.

[0014]

Further, in the nanofiber manufacturing apparatus of the présent invention, the nanofibers produced by suppressing the génération of the nanofiber discharge flow linearly directed from the nanofiber generating apparatus to the nanofiber collecting surface by the flow path suppressing means. The fibers are suspended in the housing, the gas in the housing is sucked by the suction device through the nanofiber collecting surface, and the nanofibers are collected on the nanofiber collecting surface. It is characterized by being configured.

[0015]

Further, in the nanofiber manufacturing apparatus of the présent invention, the flow path suppressing means suppresses the génération of the linear nanofiber discharge flow discharged by the nanofiber generating apparatus, and the liquid generated by failing to generate the nanofibers. In order to prevent lumps such as drops from flying linearly to the nanofiber collecting surface of the nanofiber collecting device and directly hitting the nanofiber collecting device, the nanofiber generating device and the nanofiber collecting device are used to capture the nanofibers. It is characterized by having at least one between it and the gathering surface.

[0016]

Further, in the nanofiber manufacturing apparatus of the présent invention, the size of the flow path suppressing means is formed by an assumed line connecting each apex of the nanofiber collecting surface of the nanofiber generating apparatus and the nanofiber collecting apparatus. It is characterized in that it is configured to be larger than the outer circumference of the linear flight région to be formed.

[0017]

Further, in the nanofiber manufacturing apparatus of the présent invention, when the position where the flow path suppressing means is installed is d, the distance between the nanofiber generating apparatus and the nanofiber collecting surface of the nanofiber collecting apparatus is d. The flow path suppressing means is installed at a position separated from the nanofiber collecting surface by d / 2 or more.

[0018]

The nanofiber manufacturing method of the présent invention comprises a housing, a nanofiber génération device provided in the housing, and a nanofiber collection device that collects nanofibers discharged and generated by the nanofiber génération device. It is a nanofiber manufacturing method using the provided nanofiber manufacturing equipment.

The nanofiber generator has a solution discharge nozzle for discharging a raw material polymer solution and a hot air discharge nozzle for discharging a high-pressure high-temperature highspeed gas.

The nanofiber collecting device includes a nanofiber collecting surface formed on one surface of the housing and a suction device that sucks gas in the housing from the back surface side of the nanofiber collecting surface.

The nanofiber génération device is provided with at least one flow path suppressing means between the nanofiber génération device and the nanofiber collection surface on the downstream side of the nanofiber discharge flow generated by the nanofiber génération device. It is characterized in that the nanofibers floating freely are collected by suppressing the nanofiber discharge flow linearly directed from the nanofiber collecting surface.

[0019]

The nanofiber manufacturing method of the présent invention comprises a nanofiber generator including a solution discharge nozzle for discharging a raw material polymer solution and a hot air discharge nozzle for discharging high-pressure high-temperature high-speed gas, and nanofibers discharged and generated by the nanofiber generator. In a nanofiber manufacturing method using a nanofiber collecting device equipped with a nanofiber collecting device for collecting.

At least one flow path suppressing means is provided between the nanofiber generator and the nanofiber collection surface of the nanofiber collector, and the nanofiber discharge flow discharged by the nanofiber generator is linear. It is characterized in that it suppresses flight and prevents lumps such as droplets generated by failing to be generated in nanofibers from flying to the nanofiber collection surface of the collection device and directly hitting them.

Effect of the invention

[0020]

In the présent invention, a highly homogeneous nanofiber aggregate can be collected by freely floating the nanofibers produced by the nanofiber generator in the housing and collecting the 7 nanofibers by the collector. Is. That is, in the présent invention, the generated nanofibers are dispersed by suppressing the nanofiber discharge flow generated by the nanofiber generator and flying linearly toward the nanofiber collector on the high-temperature high-speed gas flow. It can be scattered inside the housing and floated freely.

[0021]

Specifically, according to the présent invention, if a flow path suppressing means having a size described later is provided between the nanofiber generator and the nanofiber collector, the nanofiber generator produces a high-temperature and high-speed gas flow. It is possible to suppress the flow of nanofibers that ride and fly linearly toward the nanofiber collector. Moreover, since lumps such as droplets generated by the nanofiber generator can be suppressed by the flow path suppressing means, the droplets and the like do not directly hit the nanofiber collection surface of the nanofiber collection device and are homogeneous. Nanofibers can be manufactured. The présent invention is particularly effective in producing nanofiber sheets.

A brief description of the drawing

[0022]

FIG. 1 is a diagram showing an embodiment of a nanofiber manufacturing apparatus of the présent invention for manufacturing nanofibers from a molten or dissolved polymer solution.

FIG. 2 is a diagram for explaining a homogeneous appearance shape of a nanofiber sheet collected by the nanofiber manufacturing apparatus of the présent invention.

FIG. 3 is a diagram for explaining the installation position, shape, and size of the flow path suppressing means, which is a main constituent requirement of the présent invention.

FIG. 4 is a diagram illustrating an embodiment of another embodiment of the flow path suppressing means, which is a main constituent requirement of the présent invention.

FIG. 5 is a diagram for explaining in detail the function of the nanofiber generator of the nanofiber manufacturing apparatus of the présent invention.

FIG. 6 shows the basic configuration of a prior art device for producing nanofîbers from a dissolved polymer solution.

FIG. 7 is a diagram showing an extemal shape of a nanofiber sheet manufactured by a nanofiber manufacturing apparatus according to a conventional technique.

[Fig. 8] Explain that when nanofîbers are manufactured by a conventional nanofiber manufacturing device, droplets of a polymer solution that fails to become nanofîbers fly to the nanofiber collecting surface of the nanofiber collecting device. Figure (conventional technology) FIG. 9 is a diagram illustrating a position of providing a flow path suppressing means for suppressing lumps such as droplets of a polymer solution that hâve failed to become nanofîbers from flying to the nanofiber collecting surface of the nanofiber collecting device (Fig. 9). Invention of the présent application)

Mode for carrying out the invention

[0023]

As shown in FIGS. 1 and 5, the nanofiber manufacturing apparatus 100 of the présent invention includes a solution discharge nozzle 11 of a polymer solution in which a raw material polymer is dissolved in a volatile solvent, and a hot air discharge nozzle 12 of a high-pressure hightemperature high-speed gas. Nanofiber generator 10 and a housing 60 that freely floats the nanofîbers generated by the nanofiber generator 10 and nanofiber collection that sucks and collects the nanofîbers floating in the housing 60. The device 50 is provided. In the nanofiber manufacturing apparatus 100 of the présent invention, a straight line of the nanofiber discharge flow generated by the nanofiber generating apparatus 10 is provided between the nanofiber generating apparatus 10 and the nanofiber collecting surface 51 of the nanofiber collecting apparatus 50. At least one flow path suppressing means 90 for suppressing a spécifie flow is provided. As a resuit, the linear flight of the nanofiber discharge flow is suppressed, and the flight of droplets and small polymer lumps 45 that hâve failed to become nanofîbers is also suppressed, so that the lumps 45 composed of droplets and small polymer lumps are formed. Since the 9 nanofiber collecting surface 51 of the nanofïber collecting device 50 is not directly hit, the nanofiber fibers are collected on the nanofiber collecting surface 51 of the nanofiber collecting device 50 and hâve a uniform fiber diameter distribution. Nanofiber sheet 52 is produced.

[0024]

Hereinafter, the invention concept and examples of the présent invention will be described with reference to the accompanying drawings, but the présent invention is not limited to the structure of the spécifie examples thereof, and can be easily achieved by those skilled in the art. Of course, it is possible to change the design of the above, and it is within the scope of the technical idea of the présent invention.

[0025]

Hereinafter, in the description of the présent invention, a solution produced by discharging a solution obtained by dissolving a raw material polymer in a volatile solvent into a heat jet stream (dry spinning method) will be described as an example, but the raw material polymer is melted by heat. It can also be applied to a product manufactured by discharging the molten liquid into a heat jet flow (melt spinning method). Further, in the following description of the présent invention, the description will be limited to the case of manufacturing the nanofiber sheet, but if the shape of the collecting surface is three-dimensionally configured, a three-dimensional nanofiber collecting body can also be generated.

[0026]

FIG. 5 is a diagram for explaining the configuration of the nanofiber generator 10, which has been conventionally known. The nanofiber generator 10 includes a solution discharge nozzle 11 that discharges a raw material polymer solution and a hot air discharge nozzle 12 that discharges a high-pressure high-temperature high-speed gas. Although not shown in this figure, a device for supplying a solution prepared by dissolving a raw material polymer in a volatile solvent to a solution discharge nozzle 11 and a device for supplying a high-temperature high-speed gas to a hot air discharge nozzle 12 are connected to each of them. It is assumed that. The polymer solution 10 discharged from the solution discharge nozzle 11 intersects on the downstream side of the hightemperature high-speed gas flow 30 discharged from the hot air discharge nozzle 12, is stretched at the wind speed of the high-temperature high-speed gas flow 30, and the solvent is volatilized in the process. Then, a nanofiber stream 40 of polymer fibers is generated.

[0027]

The nanofiber flow 40 generated by the nanofiber generator 10 has a desired fiber diameter and a relatively long fiber length in the vicinity of the flight center axis 31 of the flow of the hightemperature high-speed gas flow 30 generated by the hot air discharge nozzle 12. The distribution density of the fibers is high, and as the flight center axis 31 deviates from the flight center axis 31, the dynamic action of the fluid increases the number of nanofibers having a small fiber diameter, a short fiber length, and a light weight. The distribution density of nanofibers with long fiber lengths tends to decrease as they deviate from the flight center axis 31. The situation is shown by changing the shade of shading in FIG. Nanofibers produce not only different fiber lengths, but also fibers with different fiber diameters.

[0028]

FIG. 6 shows the basic configuration of a nanofiber manufacturing apparatus that manufactures nanofibers with a conventionally known dissolved polymer solution. Here, the reference numerals in the drawings are the same for the components having the same functions as those of the présent invention. The polymer solution 20 and the high-pressure high-temperature high-speed gas flow 30 discharged by the nanofiber génération device 10 shown in FIG. 5 form a nanofiber flow 40 in a tubular housing 62 that surrounds the outer peripheral portion of the entire manufacturing device. It Aies linearly toward the nanofiber collection surface 51. The generated nanofiber flow 40 rides on the flow of the high-pressure high-temperature high-speed gas flow 30 discharged from the hot air discharge nozzle 12 and the suction flow 80 of the suction device 70 provided downstream of the nanofiber collection device 50. It flies toward the nanofiber collecting surface 51 of the nanofiber collecting device 50. As described above, the distribution density of nanofibers on the 11 flight central axis 31 of the high-température high-speed gas flow 30 is high, and the longer the nanofiber fiber length is, the more it is affected by the wind power and goes straight toward the nanofiber collector 50. Fly in the target. Since the fiber diameter of the nanofiber flow 40 is as thin and light as several tens of nanometers to several micrometers, the nanofiber flow 40 becomes a gas due to the dynamic action of the fluid as the distance from the flight center axis 31 of the hightemperature high-speed gas flow 30 increases. While being disturbed by the flow, it scatters into the tubular housing 62 like dust. The nanofiber flow 40 arranges a suction device 70 outside the tubular housing 62 and attracts gas in the tubular housing 62 from the rear side of the nanofiber collection device 50 (downstream side of the nanofiber collection surface 51). Is controlled and sucked, and is placed on the suction airflow in the tubular housing 62 to efficiently collect the floating nanofibers 40. The M in the frame of the suction device 70 represents a fan motor, and the arrow 80 shown outside the suction device 70 represents an air flow (suction flow) in which the gas in the tubular housing 62 is sucked and discharged to the outside.

[0029]

FIG. 7 is a schematic view showing the nanofiber sheet 55 collected by the conventional nanofiber collecting device 50. (A) is a view of the nanofiber sheet 55 viewed from the front, and (B) is a view showing a cross section of the nanofiber sheet 55 eut by a altemate long and short dash line connecting (a) and (b) and viewed from the side. As shown in FIG. 7 (A), the collected nanofiber sheet 55 is not homogeneous in its thickness. Further, in the vicinity of the center 56 of the nanofiber sheet 55, there are many nanofibers having a long fiber length and a heavy mass, and the nanofiber fibers having a small nanofiber fiber diameter and a short fiber length as shown in the outer portions 57 and 58 toward the outside. As shown in FIG. 7B, the thickness of the nanofiber sheet 55 is also thick near the center and becomes thinner toward the outside, and there is a problem that the entire nanofiber sheet 55 cannot be uniformly produced. This situation is represented by shades of shading. That is, in FIG. 7A, the darker the color, the thicker the thickness, and the lighter the color, the thinner the thickness.

[0030]

Further, in the conventional nanofiber collecting device 50, the hot air discharging nozzle is caused by a slight variation in the viscosity of the polymer solution discharged from the solution discharging nozzle 11 of the nanofiber generating device 10 and the turbulence of the air flow in the tubular housing 62. Fluctuations in the high-pressure, high-temperature, high-speed gas flow discharged from No. 12 occur. Due to this and the like, the polymer solution discharged from the solution discharge nozzle 11 is not generated as nanofibers having a desired fiber diameter, but is discharged from the hot air discharge nozzle 12 in a droplet State. , It happens that it is blown off by riding on the high température high speed gas stream 30. In that case, in particular, since the lumps 45 such as droplets hâve a larger mass than the nanofibers, unlike the nanofiber flow 40, the nanofiber collecting device 50 does not float and disperse in the tubular housing 62. The lump 45 will fly linearly toward the nanofiber collecting surface 51 like a bull et, which may damage the collected nanofiber sheet. FIG. 8 is a diagram showing the situation. It is not known in which direction the lumps 45 such as droplets fly, but assuming that they fly almost linearly in the air flow, droplets and the like formed without being generated as nanofibers in the center of the gas flow The lump 45 will fly along the flight central axis 31 of the high-temperature high-speed gas flow to the central peripheral edge of the nanofiber collection surface 51 of the nanofiber collection device 50. However, the lumps 45 such as droplets do not always occur at the center of the nanofiber collecting surface 51 of the nanofiber collecting device 50, and it is unknown in which direction they fly. However, assuming that the lumps 45 such as droplets fly linearly, most of them hâve a flight trajectory connecting the four ends (vertices) of the nanofiber collection surface 51 of the nanofiber génération device 10 and the nanofiber collection device 50. It can be estimated that it fries within the range surrounded by the outer peripheral lines 32 and 33 (straight flight région 110) and hits the nanofiber collecting surface 51. Therefore, a mass of droplets or the like flying in the linear flight région 110 surrounded by the outer peripheral lines 32 and 33 of the flight trajectory connecting the outer edges of the nanofiber collection surface 51 of the nanofiber 13 génération device 10 and the nanofiber collection device 50. If the grains 45 do not hit the nanofiber collecting surface 51 of the nanofiber collecting device 50, the collected nanofiber sheet will not be damaged. Here, the outer edge of the nanofiber collecting surface 51 means an outer peripheral edge portion in the shape of the collecting surface forming the nanofiber collecting surface 51.

[0031]

The région where the lumps 45 such as droplets generated by the nanofiber generator 10 do not damage the collected nanofiber sheet will be described in a little more detail with reference to FIG. FIG. 3 shows the nanofiber collecting surface 51 of the nanofiber generating device 10 and the nanofiber collecting device 50 (in the figure, the outer edge of the nanofiber collecting surface 51 is a quadrangle consisting of four sides and four vertices). This is a bird's-eye view showing the relationship between the two, and the flight locus outer lines 32 and 32 as assumed lines connecting the ends (vertices) of the nanofiber collecting surface 51 of the nanofiber generating device 10 and the nanofiber collecting device 50. The area surrounded by 33 and 33 is an assumed linear flight area (that is, a linear flight area 110). Here, since the embodiment in the case where the nanofiber collecting surface 51 of the nanofiber collecting device 50 is a quadrangle is shown, the assumed linear flight région 110 has a quadrangular pyramid shape, and its cross section is a nanofiber. The shape is similar to the quadrangle of the nanofiber collecting surface 51 of the collecting device 50. That is, if the shape of the nanofiber collecting surface 51 of the nanofiber collecting device 50 is, for example, a circle, an ellipse, or a polygon, the bottom surface has the shape of a cône having those shapes.

[0032]

The nanofiber manufacturing apparatus 100 of the présent invention sees the nanofiber collecting surface 51 of the nanofiber collecting apparatus 50 from the nanofiber generating apparatus 10, and suppresses a flow path having a size that makes the nanofiber collecting surface 51 invisible. Means (flow path suppressing means 90) are provided at at least one place. That is, the dimension 14 of the flow path suppressing means 90 covers the linear flight région 110 including the flight center axis 31 and surrounded by the flight locus outer peripheral lines 32 and 33, and suppresses the linear flow path of the lumps, is there. As a resuit, within the range surrounded by the outer peripheral lines 32 and 33 of the flight locus (linear flight région 110), the linear flight flow of the nanofiber flow 40 generated by the nanofiber génération device 10 is suppressed, and the flow is suppressed. , The feature is that the droplets and the like generated by the nanofiber génération device 10 are prevented from flying directly to the nanofiber collection device 50.

[0033]

FIG. 8 is a vertical cross-sectional view of a conventional nanofiber manufacturing apparatus. FIG. 9 is a vertical cross-sectional view of the nanofiber manufacturing apparatus 100 of the présent invention, which is arranged on a surface covering the flight locus outer peripheral lines 32 to 33 of the linear flight région 110 flying linearly from the nanofiber generator 10. The relationship with at least one flow path suppressing means 90 is shown. In FIG. 9, the flow path suppressing means 90 is simultaneously displayed as three flow path suppressing means 91, 92, 93 at different arrangement distances from the nanofiber generator 10.

[0034]

FIG. 1 shows a nanofiber manufacturing apparatus 100 for manufacturing a nanofiber sheet, which is a spécifie embodiment of the présent invention. At least one flow path suppressing means 90 is provided between the nanofiber generating device 10 and the nanofiber collecting device 50. As a resuit, the linear flow of the nanofiber stream 40 generated by the nanofiber generator 10 and flying on the high-temperature high-speed gas stream 30 toward the nanofiber collector 50 is suppressed. In addition, the flow path suppressing means 90 catches the lumps 45 such as droplets that hâve failed to become nanofibers in the nanofiber génération device 10, and the lumps 45 such as droplets are the nanofiber collection surface of the nanofiber collection device 50. It is configured to suppress the discharge flow that directly flies to 51.

[0035]

A virtual line (one-dot chain line in FIGS. 1 and 9) connecting the apex of the polygonal nanofiber collection surface 51 of the nanofiber collection device 50 in the housing 60 and the nanofiber génération position of the nanofiber génération device 10. The flow path suppressing means 90 is arranged on the way. For example, if the nanofiber collecting surface 51 of the nanofiber collecting device 50 is a quadrangle, the four vertices and the nanofiber génération position of the nanofiber generating device 10 (in this embodiment, the polymer solution 20 and the high température and high speed of high pressure). The fines connecting (the position where the gas flow 30 intersects) are the flight locus outer peripheral lines 32 and 33 of the linear flight région 110. By providing such a flow path suppressing means 90, the nanofiber flow 40 generated by the nanofiber generating device 10 and flying on the high-temperature high-speed gas flow 30 is suppressed by the flow path suppressing means 90 and cannot travel straight. It is swept around the flow path suppressing means 90. Then, the scattered nanofiber flow 40 wraps around the outside of the flow path suppressing means 90, flows through the area 42, and diffuses in the housing 60 in the direction of the nanofiber collecting device 50. By doing so, the nanofiber flow 40 generated by the nanofiber génération device 10 is suppressed by the flow path suppressing means 90, further diffused, and the nanofibers ride on the gas flow in which the straight-line energy is eut off. The flow is further diffused into the areas 43 and 44 and floats in the housing 60. Then, it is slowly sucked by the suction device 70 of the nanofiber collection device 50 and collected on the nanofiber collection surface 51. In order to confine the nanofibers floating in the housing 60, it is préférable that the front surface of the housing 60 is substantially sealed by the curtain 61. At this time, in considération of the balance between the gas discharge flow rate from the hot air discharge nozzle 12 and the gas suction amount from the nanofiber collection device 50, care should be taken so that the air pressure inside the housing 60 does not exhibit a vacuum State. There is a need. [0036]

2A and 2B are nanofiber sheet 52 manufactured by the nanofiber manufacturing apparatus 100 of the présent invention shown in FIG. 1, FIG. 2A is an extemal view of the nanofiber sheet 52 as viewed from the front, and FIG. 2B is (B). It is sectional drawing seen eut by the altemate long and short dash line connecting a) and (b). This is because the flow path suppressing means 90, which is the main constituent requirement of the présent invention, is provided at one or more places, so that the nanofiber fibers are homogeneous over the entire surface of the nanofiber collecting surface 51 and the sheet thickness is also constant. The sheet 52 can be manufactured. [0037]

The configuration that the flow path suppressing means 90 of the présent invention should include is such that the nanofiber collecting surface 51 of the nanofiber collecting device 50 cannot be seen when the flow path suppressing means 90 is viewed from the nanofiber generating device 10 side. Is préférable. That is, the apex of the polygonal nanofiber collection surface 51 of the nanofiber collection device 50 and the nanofiber génération position of the nanofiber génération device 10 (the solution discharge nozzle 11 of the polymer solution and the hot air that discharges high-pressure high-temperature high-speed gas). It is préférable that the size of the flow path suppressing means 90 is larger than the range surrounded by the flight locus outer peripheral fines 32 and 33 (one-point chain line in FIG. 3) connecting the discharge nozzle 12). In this way, the flow path suppressing means 90 can prevent the lumps 45 such as droplets that fail to become nanofibers in the nanofiber génération device 10 and try to fly linearly. As a resuit, it is suppressed that the droplets fly between the flow path suppressing means 90 and the nanofiber collecting device 50 in the trajectory indicated by the altemate long and short dash line (assumed flight locus outer peripheral fines 32, 33), and the droplets are suppressed from the nanofiber collecting device 50. It is possible to suppress direct hitting of the nanofiber collecting surface 51. When the lumps 45 such as droplets are suppressed by the flow path suppressing means 90, the linear kinetic energy of the lumps 45 such as droplets is drastically reduced, and even if the lumps 45 such as droplets are sucked by the suction device 70, the nanofiber collecting device 50 The nanofiber sheet 52 collected on the nanofiber collecting surface 51 of the above is not damaged. Even if the size of the flow path suppressing means 90 is smaller than the size of the extension of the flight locus 17 outer peripheral Unes 32 and 33, the effect of suppressing the linear flight of the nanofibers is sufficient.

[0038]

The location of the flow path suppressing means 90 between the nanofiber generating device 10 and the nanofiber collecting device 50 and the size of the flow path suppressing means 90 are important. The position where the flow path suppressing means 90 is arranged and the size of the flow path suppressing means 90 will be described in detail with reference to FIG.

[0039]

First, the position where the flow path suppressing means 90 is arranged will be described. When the flow path suppressing means 90 is arranged near the nanofiber collecting surface 51 of the nanofiber collecting device 50, the flow path suppressing means 90 having a large area is required. In addition to that, it is not possible to capture early droplets and the like, and the nanofibers that float and should be normally collected by the nanofiber collection device 50 are placed on the nanofiber collection surface 51 of the nanofiber collection device 50. Most of the flow path will be obstructed, which will hinder the collection of nanofibers.

[0040]

On the other hand, if the flow path suppressing means 90 is arranged near the nanofiber génération position of the nanofiber generating device 10, the flow path suppressing means 90 can be small, but the solvent contained in the polymer solution is not completely volatilized, that is, In the process of drawing and forming into nanofibers, fibers that hâve not yet become nanofibers are welded together to form polymer fiber lumps 45, resulting in nanofibers with a desired fiber diameter. There is a problem that it cannot be generated. Therefore, the flow path suppressing means 90 needs to secure a sufficient distance for the polymer solution discharged from the nanofiber génération device 10 to be generated in the nanofibers, and the nanofiber flow 40 is inside the housing 60. It is necessary to sufficiently float and secure a space for collecting by the nanofiber collecting device 50.

[0041]

The distance from the nanofiber generator 10 to the flow path suppressing means 90 dépends on the performance of the nanofiber generator 10, so a numerical guideline cannot be given unconditionally, but it is discharged by trial and error. It goes without saying that the polymer solution to be produced must be placed at a sufficient distance to be stretched and produced on the nanofibers.

[0042]

In FIG. 1, the distribution density of the nanofiber flow 40 in the housing 60 when one flow path suppressing means 90 is arranged between the nanofiber génération device 10 and the nanofiber collection device 50 is also shaded. It is represented by the density and is schematically shown in the figure. In FIG. 1, the darker the shaded color, the higher the distribution density, and the lighter the color, the lower the distribution density.

[0043]

As shown in FIG. 1, since the flow path of the nanofibers generated by the nanofiber génération device 10 is blocked by the flow path suppressing means 90, the nanofiber distribution density in the area 41 immediately behind the flow path suppressing means 90 is shown in the figure. It becomes thin like. On the other hand, the linear flow of the nanofibers whose linear flight is suppressed by the flow path suppressing means 90 is blocked and spreads in ail directions in front of the flow path suppressing means 90. The nanofiber fibers are very light and the flow of the nanofibers is disturbed. The low-density nanofibers away from the flight center axis 31 are disturbed and mixed and flow to the outside of the flow path suppressing means 90, and the distribution density of the nanofibers in the area 42 becomes high as shown in the figure. However, the nanofibers having a distribution density in the area 42 are diffused and suspended by the gas flow in the housing 60, and the nanofibers in the areas 43 and 44 gradually become thinner and finally become thinner. Is a State in which ail the nanofibers generated by the nanofiber generator 10 are mixed and integrated, floats in the housing 60, and the suction device 70 sucks the gas in 19 the housing 60 to capture the nanofibers. It is collected by the collecting device 50. Therefore, as shown in FIG. 2, the collected nanofiber sheet 52 can produce a homogeneous sheet over the entire surface of the sheet.

[0044]

In order to produce a uniform and excellent quality nanofiber sheet, the nanofiber collecting device 50 is required to collect nanofibers having a uniform fiber diameter over the entire nanofiber collecting surface 51., The nanofibers produced by the nanofiber generator 10 require a suffi ci ent space to float in the housing 60. In order to suppress the linear flight of the generated nanofibers by trial and error, as shown in FIG. 3, from the flow path suppressing means 90 to the nanofiber collecting surface 51 of the nanofiber collecting device 50. The distance 1 is the total space distance d of the housing 60 (from the nanofiber génération device 10) so that a suffi ci ent space from the flow path suppressing means 90 to the nanofiber collection surface 51 of the nanofiber collection device 50 can be secured. It is désirable to arrange the nanofiber collecting device 50 at a position that secures more than half of the distance to the nanofiber collecting surface 51). More preferably, it is désirable that the distance 1 secures a distance of 2/3 to 1/2 or more of the distance d between the nanofiber generating device 10 and the nanofiber collecting device 50.

[0045]

Next, the size and shape of the flow path suppressing means 90 will be described with reference to FIGS. 3 and 4. The flight locus indicated by a single point chain line connecting each vertex (arbitrary point on the circumference when the collection surface is circular) of the polygonal nanofiber collection surface 51 of the nanofiber génération device 10 and the nanofiber collection device 50. The space surrounded by the outer peripheral lines 32, 32, and 33, 33 is an assumed space (assumed linear flight région 110) in which the lumps 45 such as droplets fly in a straight line. Therefore, it is sufficient to suppress the flight of the lumps 45 such as droplets flying in this assumed space. The size of the flow path suppressing means 90 is a plane parallel to the nanofiber collecting surface 51 at the position where the flow path suppressing means 90 is arranged, and 20 the assumed space (assumed linear flight area 110) in which droplets and the like fly straight. ) Should be larger than the area that closes it. That is, the size may be larger than the vertical crosssectional area parallel to the bottom surface of the quadrangular pyramid with the nanofiber collecting surface 51 as the bottom surface and the nanofiber generating device 10 as the apex. Of course, as described above, even if the size of the flow path suppressing means is smaller than the above-mentioned vertical cross-sectional area, the effect is sufficient.

[0046]

FIG. 3 shows the flow path suppressing means 90 that closes the assumed linear flight région 110, the flow path suppressing means 91 that is arranged far away from the nanofiber collecting surface 51, and the flow path suppressing means that is arranged in the middle. 92, the flow path suppressing means 93 arranged nearby is displayed at the same time. In the présent invention, these flow path suppressing means 91, 92, 93 are installed at at least one place, but a plurality of these flow path suppressing means 91, 92, 93 can be installed at the same time if necessary.

[0047]

FIG. 4 is a diagram showing an example of the size and shape of the flow path suppressing means 90 (91, 92, 93), and FIG. 4A is a distance from the nanofiber collecting surface 51 and a distance from the nanofiber generating device 10. It shows a case where the assumed space (linear flight région outer circumference 111) in which droplets and the like fly straight and the flow path suppressing means 91 hâve the same size and the same shape. (B) is arranged at a middle distance from the nanofiber generator 10, and has the same shape as the assumed space (linear flight région outer circumference 112) in which the flow path suppressing means 92 flies linearly. It is (square) and the size is large. (C) is arranged at a distance far from the nanofiber generator 10 (a distance close to the nanofiber collecting surface 51), and the flow path suppressing means 93 is an assumed space (straight line) in which droplets and the like fly straight. The shape (circular) is different from that of the target flight région outer circumference 113), and the size is increased. That is, the flow path suppressing means of (B) and (C) shows another embodiment, and (B) is a surface 112 21 (linear flight région outer circumference) blocked by the nanofiber collecting surface 51 and the flow path suppressing means 92. ) Is a similar shape, and (C) has a circular shape of the flow path suppressing means 93 that covers the surface 113 (outer circumference of the linear flight région). That is, the flow path suppressing means 90 does not necessarily hâve to hâve a shape similar to the assumed surface 113 (outer circumference of the linear flight région) to be closed by the flow path suppressing means 90. When the flow path suppressing means 92 has the shape and size shown in FIG. 4 (B), the four corners of the flow path suppressing means 92 are angular and the flow of nanofibers suddenly changes near the four corners. In the case of the shape, since there are no four corners, the change in the flow of nanofibers becomes soft.

[0048]

The flow path suppressing means 90 (91, 92, 93) may cover the linear flight région 110 (the flying région where the linear flight of nanofibers is assumed), and the flow path suppressing means 90 (91, 92, 93) The shape of is free. The essence of the présent invention is to prevent the nanofibers generated and discharged by the nanofiber génération device 1 from flying directly to the nanofiber collection surface 51 of the nanofiber collection device 50 by the high-temperature high-speed gas flow 30. In the above description, an embodiment in which the plate-shaped flow path suppressing means 90 is provided as the means is described, but the présent invention is not limited to the plate-shaped member, and the flow of the nanofibers is linear. Any means may be used.

[0049]

Although not shown, the flow path suppressing means 90 of the présent invention is not limited to the one installed on the flight center axis 31 of the high température and high speed gas flow, and the flight center axis is not limited to the one installed on the flight center axis 31 of the high température and high speed gas flow from the ceiling surface, bottom surface, and upper and lower side surfaces of the housing 60. It is also possible to use a flow path suppressing means extending to the 31 side and forming an opening in the flight central shaft 31 portion. In that case, the flow path suppressing means 90 (91, 92, 93) installed on the flight center axis 31 and the flow path 22 suppression extending from the ceiling surface, the bottom surface, and the upper and lower side surfaces of the housing 60 toward the flight center axis 31 side. It is désirable to install the means altemately. Further, in that case, the size of the opening of the flight center axis 31 portion of the flow path suppressing means extending from the ceiling surface, the bottom surface, and the upper and lower side surfaces of the housing 60 toward the flight center axis 31 is set on the flight center axis 31. It is better not to form a linear flow path of nanofîbers by making it smaller than the size of the installed flow path suppressing means 90 (91, 92, 93).

[0050]

As described above, the présent invention particularly relates to an apparatus and a manufacturing method for producing nanofîbers from a polymer solution dissolved in a solvent, in which droplets and small polymer lumps 45 in which the polymer solution fails to become nanofîbers are formed., A nanofiber manufacturing device suitable for manufacturing a homogeneous nanofiber sheet without damaging the collected nanofiber laminated surface by directly hitting the nanofiber collecting surface 51 of the nanofiber collecting device 50. And a manufacturing method.

Code description

[0051]

100 Nanofiber manufacturing equipment

Nanofiber generator

Solution discharge nozzle

Hot air discharge nozzle

Polymer solution

High-temperature high-speed gas flow

Flight center axis of high-temperature high-speed gas flow , 33 Flight locus outer circumference (trajectory line of the outer circumference of the linear flight région 110 where linear flight of polymer droplets is assumed due to high-temperature highspeed gas flow)

Nanofiber flow (nanofiber flying State) , 42, 43, 44 Area showing the distribution density of scattered nanofîbers lump grain

Nanofiber collecter

51 Nanofiber collection surface

Nanofiber sheet (invention of the présent application)

Nanofiber sheet (conventional technology) housing curtain

62 Cylindrical housing (conventional technology) suction device suction flow

M fan motor

Flow path suppression means

91, 92, 93 Flow path suppression means placed at a different position in parallel with the nanofiber collection surface

110 Linear flight area

111,112,113 Outer circumference of linear flight area

Claims (7)

1. [Claim 1]

   A nanofiber manufacturing apparatus including a housing, a nanofiber generating device provided in the housing, and a nanofiber collecting device for collecting nanofibers discharged and generated by the nanofiber generating device.,

   The nanofiber generator has a solution discharge nozzle for discharging a raw material polymer solution and a hot air discharge nozzle for discharging a high-pressure high-temperature highspeed gas.

   The nanofiber collecting device has a nanofiber collecting surface formed on one surface of the housing and a suction device that sucks gas in the housing from the back surface side of the nanofiber collecting surface.

   On the downstream side of the nanofiber discharge flow generated by the nanofiber generator, at least one flow path suppressing means for suppressing the nanofiber discharge flow linearly directed from the nanofiber generator to the nanofiber collection surface. A nanofiber manufacturing device characterized by being equipped with.
2. [Claim 2]

   The flow path suppressing means suppresses the génération of the nanofiber discharge flow linearly directed from the nanofiber generating device to the nanofiber collecting surface, and the generated nanofibers are suspended in the housing to obtain the above. The first aspect of claim 1, wherein the gas in the housing is sucked by the suction device through the nanofiber collecting surface, and the nanofibers are collected on the nanofiber collecting surface. Nanofiber manufacturing equipment.
3. [Claim 3]

   The flow path suppressing means suppresses the génération of a linear nanofiber discharge flow discharged by the nanofiber generator, and the lumps generated by failing to generate the nanofibers are the nanofibers of the nanofiber collector. The feature is that at least one is provided between the nanofiber generator and the nanofiber collection surface of the nanofiber collection device in order to prevent the nanofiber génération device from flying linearly and hitting the collection surface directly. The nanofiber manufacturing apparatus according to claim 1.
4. [Claim 4]

   The size of the flow path suppressing means is larger than the outer circumference of the linear flight région formed by the assumed line connecting each apex of the nanofiber collecting surface of the nanofiber generating device and the nanofiber collecting device. The nanofiber manufacturing apparatus according to claim 1, wherein the nanofibers are manufactured.
5. [Claim 5]

   The position where the flow path suppressing means is installed is such that when the distance between the nanofiber generating device and the nanofiber collecting surface of the nanofiber collecting device is d, the flow path suppressing means is used to collect nanofibers. The nanofiber manufacturing apparatus according to claim 1 or 2, wherein the nanofibers are installed at a position separated from the surface by d / 2 or more.
6. [Claim 6]

   A nanofiber manufacturing apparatus including a housing, a nanofiber generating device provided in the housing, and a nanofiber collecting device for collecting nanofibers discharged and generated by the nanofiber generating device was used. It is a nanofiber manufacturing method The nanofiber generator has a solution discharge nozzle for discharging a raw material polymer solution and a hot air discharge nozzle for discharging a high-pressure high-temperature highspeed gas.

   The nanofiber collecting device includes a nanofiber collecting surface formed on one surface of the housing and a suction device that sucks gas in the housing from the back surface side of the nanofiber collecting surface.,

   The nanofiber génération device is provided with at least one flow path suppressing means between the nanofiber génération device and the nanofiber collection surface on the downstream side of the nanofiber discharge flow generated by the nanofiber génération device. A nanofiber manufacturing apparatus characterized by collecting freely floating nanofibers by suppressing a nanofiber discharge flow linearly directed from the nanofiber collecting surface.
7. [Claim 7]

   A nanofiber generator consisting of a solution discharge nozzle that discharges a raw material polymer solution and a hot air discharge nozzle that discharges high-pressure high-temperature high-speed gas, and a nanofiber collector that collects nanofibers discharged and generated by the nanofiber generator. In the nanofiber manufacturing method using the nanofiber manufacturing apparatus equipped with

   At least one flow path suppressing means is provided between the nanofiber generator and the nanofiber collection surface of the nanofiber collector, and the nanofiber discharge flow discharged by the nanofiber generator is linear. A nanofiber manufacturing method characterized by suppressing flight and suppressing the lumps generated by failing to be generated into nanofibers from flying to the nanofiber collecting surface of the nanofiber collecting device and directly hitting them.