WO2021172754A1 - Nanomembrane having uniform basis weight, and production method therefor - Google Patents

Abstract

The present invention relates to a nanomembrane produced using electrospinning, and a production method therefor, and more specifically, to a nanomembrane and a production method therefor, the nanomembrane having improved evenness by having a uniform basis weight, by means of using a nozzle block having a plurality of nozzle plates and nozzle tubes arranged.

Description

Nanomembrane with uniform basis weight and manufacturing method thereof

This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0023089 dated February 25, 2020, and all contents disclosed in the documents of the Korean patent application are incorporated as a part of this specification.

The present invention relates to a nanomembrane, and more particularly, to a nanomembrane having a uniform basis weight and improved uniformity by using a nozzle block in which a plurality of nozzle plates and nozzle tubes are arranged, and a method for manufacturing the same.

Conventionally, in the fields of food, packaging materials, pharmaceuticals, etc., in order to prevent the permeation of gas such as water vapor or oxygen, a gas having a relatively simple structure in which an inorganic film such as a vapor deposition film of metal or metal oxide is formed on the surface of a resin substrate. Barrier films have been used.

In recent years, such a gas barrier film that prevents the permeation of water vapor and oxygen is also used in the field of electronic devices such as liquid crystal display elements (LCD), solar cells (PV), and organic electroluminescence (EL). . That is, it is necessary to provide such an electronic device with a property of being flexible, light and hard to break, and for this, a gas barrier film having the property is used.

Although electronic devices based on nanofibers are still at a conceptual stage, they have a large surface area, variety of surface treatments, ease of construction of composite materials, and flexibility with limitations in film form to create foldable electronic materials. In order to overcome this, it is necessary to provide flexibility by making a fibrous structure. Therefore, the production of a transparent mat composed of nanofibers with excellent flexibility is easy to impart electronic performance and has a high possibility of replacing many electronic device markets due to various advantages. Examples of possible fiber-based electronic devices include textile solar cells, flexible transistors, flexible displays, external stimulation-type drug delivery, biosensors and gas sensors, light control functional textiles, functional clothing and functional products for the defense industry. .

As a measure for obtaining the gas barrier film applicable to an electronic device, the method of forming the inorganic film thickened on the resin base material is mentioned. However, simply by thickening the inorganic film, defects such as cracks are likely to occur in the inorganic film, and sufficient gas barrier properties cannot be obtained. Therefore, in order to prevent the occurrence of cracks in the thickened inorganic film, a gas barrier film formed by using an organic film as an adhesive layer, specifically, a gas barrier film formed by alternately laminating units including an inorganic film and an organic film on a resin substrate A film is proposed.

Many efforts are being made to form a network with a new type of fiber-type material that is ideal for replacing existing materials in high-performance next-generation devices such as solar cells, touch screens, skin-like sensors, displays, and smart windows. However, the reality is that it is not easy to manufacture a mat composed of transparent nanofibers.

An object of the present invention is to provide a nanomembrane having a uniform basis weight and improved uniformity by using a nozzle block in which a plurality of nozzle plates and nozzle tubes are arranged in order to solve the problems of the prior art, and a method for manufacturing the same do it with

A method of manufacturing a nano-membrane according to an embodiment of the present invention comprises: supplying a spinning solution obtained by dissolving a polymer in an organic solvent to a spinning solution main tank of an electrospinning apparatus; The spinning liquid supplied to the spinning liquid main tank is quantitatively supplied into a plurality of nozzles located in the nozzle block through a metering pump; And each spinning liquid supplied from each nozzle is spun through the nozzle on a collector spaced apart from the nozzle at a predetermined distance to form a nanofiber layer, wherein the nozzle block has a structure in which a plurality of nozzle plates and nozzle tubes are arranged. and a plurality of nozzles located on the nozzle plate and the nozzle tube are movable up, down, left and right.

In this case, the nozzle block may have a structure in which two nozzle plates and three nozzle tubes are alternately arranged.

Also, the plurality of nozzles disposed on the nozzle plate and the nozzle tube may have the same or different diameters.

In addition, the electrospinning device collects the spinning solution that overflowed without being spun from the nozzle in the overflow spinning solution storage tank and transfers the moisture contained in the solvent in the spinning solution to the receiving tank while controlling the vacuum and temperature and stirring. It may include a moisture removal device.

In addition, the nozzle plate and the nozzle pipe each have a metering pump and a control valve, and the spinning liquid supplied to each of the nozzle plate and the nozzle pipe may be the same or different from each other.

The polymer is polylactic acid (PLA), polycarbonate (PC), polyvinylidene fluoride (PVDF), polypropylene (PP), polyethylene terephthalate (PET), polyethersulfone (PES), polyamide, polyvinyl acetate , polymethyl methacrylate, polyacrylonitrile (PAN), polyurethane (PUR), polybutylene terephthalate (PBT), polyvinylbutylral, polyvinyl chloride, polyethyleneimine, polyvinyl acetate (PVAc), polyethylene It may be one or two or more selected from the group consisting of naphthalate (PEN), polyvinyl alcohol (PVA), polyethyleneimide (PEI), polycaprolactone (PCL), and polylactic acid glyceryl acid (PLGA).

The organic solvent is methylene chloride, phenol, formic acid, sulfuric acid, m-cresol, tifluoroacetandhydride/dichloromethane, water, N-methylmorpholine N-oxide, chloroform, tetrahydrofuran, methyl Isobutyl ketone, methyl ethyl ketone, m-butyl alcohol, isobutyl alcohol, isopropyl alcohol, methyl alcohol, ethanol, hexane, tetrachloroethylene, acetone, propylene glycol, diethylene glycol, ethylene glycol, trichloroethylene, di Chloromethane, toluene, xylene, cyclohexanone, cyclohexane, n-butyl acetate, ethyl acetate, butyl cellosalb, 2-ethoxyethanol acetate, 2-ethoxyethanol, dimethylformamide and dimethylacetamide It may be one or two or more selected from the group consisting of.

In addition, the nanomembrane according to an embodiment of the present invention is manufactured by the above manufacturing method, and may have a thickness of 0.1 to 20 μm and a basis weight of 1 to 10 g/m ² .

The method of manufacturing a nanomembrane according to an embodiment of the present invention can uniformly control the basis weight of the nanofiber layer by using a nozzle block in which a plurality of nozzle plates and nozzle tubes are arranged.

In addition, the nanofiber layer can be prepared by electrospinning, the electrospinning device according to the present invention can supply and recover each polymer solution uniformly, can be reused after automatic recalibration, and can continuously supply polymer There are advantages that can be

1 is a view schematically showing an electrospinning apparatus according to an embodiment of the present invention.

Figure 2 is a view schematically showing the nozzle plate and the nozzle tube of the electrospinning apparatus according to an embodiment of the present invention.

Figure 3 is a view schematically showing a water removal device of the electrospinning apparatus according to an embodiment of the present invention.

Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

In describing each figure, like reference numerals have been used for like elements. In the accompanying drawings, the dimensions of the structures are enlarged than the actual size for clarity of the present invention. Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. Also, when a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where it is "directly on" another part, but also the case where there is another part in between. Conversely, when a part of a layer, film, region, plate, etc. is said to be “under” another part, this includes not only cases where it is “directly under” another part, but also cases where another part is in between. In addition, in the present application, “on” may include the case of being disposed not only on the upper part but also on the lower part.

Hereinafter, embodiments of the present invention will be described in more detail.

The nanomembrane according to an embodiment may include a nanofiber layer formed by electrospinning a spinning solution.

The nanofiber layer according to the present invention is characterized in that it is formed by electrospinning a spinning solution on the collector.

In this case, the nanofiber layer may have a structure in which the first nanofiber layer and the second nanofiber layer are laminated, and the fiber diameters of the first nanofiber layer and the second nanofiber layer may be the same or different from each other. In addition, the polymers forming the first nanofiber layer and the second nanofiber layer may be the same as or different from each other.

On the other hand, when the polymers forming the first nanofiber layer and the second nanofiber layer are identical to each other, it is preferable that the fiber diameters of the first nanofiber layer and the second nanofiber layer are different from each other. Here, the fiber diameter of the first nanofiber layer may be 80 to 120nm, the fiber diameter of the second nanofiber layer may be 250 to 500nm.

In this case, the thickness of the nanofiber layer is preferably 0.1 to 20 μm, and the basis weight is preferably 0.1 to 10 g/m ² . When the thickness of the nanofiber layer is less than 0.1 μm, it is difficult to peel from the support, and when it exceeds 20 μm, there is a problem of poor processability and economical efficiency, and when the basis weight of the nanofiber layer is ^{less than 0.1 g/m 2} , the filtration efficiency is reduced, 10 g If /m ^{2 is} exceeded, a problem of poor processability and economic feasibility occurs.

In the present invention, the preparation of the nanofiber layer as described above can be achieved by using an electrospinning device.

In general, electrospinning uses a high voltage applied to a polymer spinning solution to eject fine fibers. That is, it is a method of obtaining a nanofiber in the form of a nonwoven fabric by instantaneously spinning into a fiber form using a polymer in a low viscosity state by electrostatic force. Electrospinning has the characteristic of making fibers having a diameter of nanometers beyond micrometers. In the case of nanofibers, since they have a larger surface area than conventional fibers, there is an advantage in that filtration efficiency can be increased when using the nanofibers as a membrane.

Electrospinning is classified into bottom-up electrospinning and top-down electrospinning.

First, the bottom-up electrospinning uses a bottom-up electrospinning device. In the bottom-up electrospinning device, the spinning nozzle is located at the bottom, and the collector is located at the top spaced apart from the nozzle. The polymer spinning solution is electrospun from the spinning nozzle at the bottom to form nanofibers on the collector at the top. In the case of using the bottom-up electrospinning apparatus, there is an advantage in that it is possible to produce high-quality nanofibers by effectively preventing the droplet phenomenon. However, all of the polymer spinning solution is not nanofiberized, and there are problems such as the remaining spinning solution flowing down the nozzle wall.

On the other hand, the top-down electrospinning uses a top-down electrospinning device, and the top-down electrospinning device has a spinning nozzle located at an upper end, and a collector is located at a lower end spaced apart from the nozzle. The polymer spinning solution is electrospun from the spinning nozzle at the top to form nanofibers on the collector at the bottom. In the case of using the top-down electrospinning device, all of the polymer spinning solution to be spun into nanofibers has the advantage of high productivity.

Hereinafter, the electrospinning apparatus used in the present invention will be described.

The electrospinning apparatus of the present invention is a spinning liquid main tank filled with a spinning liquid therein, a metering pump for quantitative supply of a polymer spinning liquid filled in the spinning liquid main tank, and a polymer spinning liquid in the spinning liquid main tank, , a plurality of nozzles in the form of pins are arranged, and a nozzle plate including a recovery device for recovering the solution remaining after spinning and a nozzle block in which a plurality of nozzle tubes are arranged, and nanofibers spun by being located at the lower end or upper end of the nozzle It is configured to include a block accommodating therein a collector spaced apart from the nozzle and a voltage generating device for generating a voltage in the collector, and a case composed of a conductor or a non-conductor in the block in order to integrate them. In general, the electrospinning device uses two main tanks for spinning solution. However, it is also possible to use one main tank for spinning solution, divide the inner space into two compartments, and then fill each divided space with two different types of spinning solution, respectively. In addition, when three or more polymers are used, the inside of the spinning liquid main tank may be divided into three or more spaces, and three or more spinning liquid main tanks may be provided to provide each polymer solution.

According to the structure as described above, the electrospinning device is continuously quantitatively supplied to a plurality of nozzles to which a high voltage is applied through a precision metering pump in which the spinning liquid filled in the spinning liquid main tank in the block is supplied to the nozzles. The spinning solution of the polymer to be used is spun and focused on a collector to which a high voltage is applied through a nozzle to prepare a nanofiber layer.

The spinning liquid supplied to each of the spinning liquid main tank is continuously quantitatively supplied into a plurality of nozzles located in the nozzle block through a precision metering pump. Each of the spinning liquid supplied from the respective nozzles is accumulated on the support while being spun and focused on the collector to which a high voltage is applied through the nozzle.

At this time, the nozzle block has a structure in which a plurality of nozzle plates and nozzle tubes are arranged, and the nozzle plates and nozzle tubes are movable up, down, left and right, and can be operated individually. Specifically, the nozzle block may have a structure in which two nozzle plates and three nozzle tubes are alternately arranged as shown in FIG. 1 , but is not limited thereto.

In addition, the supply of the spinning solution to the nozzle plate and the nozzle tube can be controlled by the micro pressure formed by using a precision metering pump to control the supply and spinning of the solution. In addition, the nozzles installed on the nozzle plate and the nozzle tube may have different diameters, the nozzle spacing may be adjusted, and the amount of radiation may be changed. Specifically, the nozzle block may have a shape in which the diameter and spacing of the nozzles are gradually increased in the moving direction of the long sheet with respect to the collector.

As shown in FIG. 2 , the plurality of nozzle tubes and the nozzle plate each have a metering pump and a control valve, and the spinning liquid supplied to each nozzle plate and the nozzle tube may be the same or different from each other. Specifically, two or more different polymer spinning solutions may be spun within one nozzle plate (or nozzle tube), and different types of polymer spinning solutions may be spun for each nozzle plate (or nozzle pipe). .

In addition, in order to promote fiber formation by electric force, a voltage of 1 kV or more, more preferably 70 kV or more, generated by a voltage generator is applied to the nozzle block and the collector. In addition, it is more advantageous in terms of productivity to use an endless belt as the auxiliary belt or wire belt. It is preferable that the collector reciprocates a predetermined distance from side to side in order to make the density of the nanofiber layer uniform.

And, the front end of the electrospinning device is provided with a supply roller (Unwinder) for supplying a long sheet on which a polymer spinning solution is spun from a block to form a laminated nanofiber, and a long sheet on which a nanofiber is laminated is provided at the rear end. It is provided with a winding roller (Rewinder) for.

In this case, the long sheet on which the nanofibers are laminated is preferably a release paper film.

The long sheet is provided for preventing sagging and transporting the nanofibers. The long sheet is wound on one side and the other side to a supply roller provided at the front end of the electrospinning device and a winding roller provided at the rear end.

In addition, auxiliary belts are respectively provided between the collector and the elongated sheet, and the elongated sheet on which the nanofibers are laminated by being accumulated in each collector through each auxiliary belt is transported in the horizontal direction. That is, the auxiliary belt rotates in synchronization with the feed speed of the long sheet, and has a roller for the auxiliary belt for driving the auxiliary belt. The roller for the auxiliary belt is an automatic roller having extremely low frictional force of two or more. Since the auxiliary belt is provided between the collector and the long sheet, the long sheet is smoothly transferred without being pulled by the collector to which a high voltage is applied.

In addition, when the long sheet passes through the electrospinning section, it is affected by contraction and expansion due to resistance by the electromagnetic field, which adversely affects the quality of the nanofiber and the transfer and winding of the fabric. By driving the wire belt, which is a belt, separately or together with the main winding device in the direction of the fabric travel, it is possible to solve the adverse effect as described above. At this time, the form of the wire belt, which is an auxiliary belt, is preferably a seamless structure for a membrane and a liquid filter, and a seamless structure for a general filter.

According to the structure as described above, the spinning solution filled in the spinning solution main tank in the block of the electrospinning device is spun onto the long sheet located on the collector through the nozzle, and the spinning solution spun on the long sheet is accumulated. As a result, nanofibers are laminated. And the auxiliary belt is driven by the rotation of the auxiliary belt rollers provided on both sides of the collector, and the long sheet is transferred while being positioned in the block at the rear end of the electrospinning device to repeatedly perform the above process.

On the other hand, the nozzle block is composed of a plurality of nozzles arranged upward or downward from the discharge port for the spinning solution, a plate or tube body in which the nozzles are arranged in a line, a main tank for spinning solution, and a pipe for spinning solution.

First, the spinning solution main tank connected to the spinning solution main tank to receive and store the spinning solution supplies the spinning solution to the nozzle through the spinning solution distribution pipe by the precision pump with the discharge amount of the solution, so that spinning proceeds. Here, the plate body or pipe body comprising a plurality of nozzles in a row receives the same spinning solution from the spinning solution storage tank, but a plurality of spinning solution main tanks are provided and each plate or pipe body is supplied with different types of polymers. It is also possible that different types of spinning solutions are supplied and spun. In addition, the nozzles can have different diameters, the nozzle spacing can be adjusted, and the amount of radiation can be changed, and the diameter of the nanofiber stacking can also be adjusted for each layer.

When spinning from the outlets of the plurality of nozzles, the solution that is not nanofiberized and overflowed is moved to the overflow solution storage tank. The overflow solution storage tank is connected to the spinning solution main tank, so the overflow solution can be reused for spinning.

At this time, the solution overflowed without spinning contains moisture when in contact with air, and if the moisture content in the solution increases by a certain ratio (2.5% or more), it affects product quality, such as causing pinholes during spinning. Therefore, when the solution overflowed without spinning is stored, it is necessary to maintain the moisture content below a certain ratio.

As shown in FIG. 3, the electrospinning device of the present invention may include a moisture removal device to maintain a moisture content suitable for electrospinning. This water removal device collects the overflowed solution (recovery solution) that cannot be nanofibrillated in a water removal pressure tank and separates the solvent containing water in the solution through vacuum, temperature control, and stirring process in a separate receiving tank (solvent condensation tank) It is structured to receive At this time, the solvent containing water has a solvent ratio of about 60 to 75%, and can be reused through a reprocessing process through a solvent condensation tank.

In addition, the water removal device is connected to the general solution supply line control device, and the recovered solution maintains a moisture content suitable for electrospinning through the water removal pressure tank, and then goes through the calibration tank and then transferred to the solution service tank. , which can be reused for radiation.

At this time, the circulating flow sequence of the recovery solution is as follows.

Service tank → pressurized tank → solution supply pipe → nozzle plate or nozzle pipe → (recovery tank) → water removal pressure tank → calibration tank → service tank

On the other hand, the rear end of the electrospinning apparatus of the present invention may include a plurality of multi-stage heating rolls having a structure capable of temperature control and compression for the purpose of removing residual solvent remaining in the fabric and the collected nanofibers when passing through the electrospinning section. have. After selectively passing through a plurality of multi-stage heating rolls, the fabric and nanofibers pass through a physical surface treatment (UV, laser, plasma irradiation, etc.) section again to modify the surface of the nanofiber and It is possible to improve the adhesion between the fibers.

In addition, a laminating device is installed at the rear end of the electrospinning device of the present invention. The laminating device applies heat and pressure, and through this, nanofibers and nanofibers, nanofibers and nonwoven fabrics or other fabrics are adhered, and then wound on a winding roller to prepare a nanofiber layer.

The electrospinning device can increase the collection area to make the integration density of the nanofibers uniform, and effectively prevent the droplet phenomenon to improve the quality of the nanofiber, and the fiber formation effect by electric force is increased to increase the nanofiber Fibers can be mass-produced. In addition, since the material and the electrospinning conditions can be adjusted differently in electrospinning in a block provided with a nozzle composed of a plurality of pins, the width and thickness of the long sheet can be freely changed and adjusted.

On the other hand, precise temperature and humidity control and cleanliness of the area where electrospinning occurs are very important factors. Therefore, in order to satisfy this condition, the electrospinning apparatus of the present invention may include a constant temperature and humidity constant. The thermo-hygrostat adjusts the temperature and humidity during the electrospinning process, operates to change the size of the fiber diameter at the same time, and removes and treats the solvent generated during the process and can be reused.

At this time, the processing sequence of the constant temperature and humidity device is as follows.

Pre-filter → 1st medium filter / Heating and cooling / 1st dehumidification → 2nd medium filter / Heating and cooling / 2nd dehumidification → Recycled recovered air → Final dry dehumidification → 3rd Medium filter / Heating and cooling → Humidification adjustment → Final Filter → Radiation area supply

In addition, the electrospinning apparatus of the present invention may include a temperature control control device for adjusting the viscosity with a temperature control control device in order to maintain the fiber viscosity suitable for electrospinning.

As the temperature control control device, both or any one of a heating device capable of maintaining a low viscosity of a high viscosity polymer spinning solution reused through overflow and a cooling device capable of maintaining a high viscosity of a relatively low viscosity polymer spinning solution can be provided.

As for the temperature in the electrospinning region, the temperature of the region where electrospinning occurs (hereinafter referred to as 'spinning region') changes the surface tension of the spinning solution by changing the viscosity of the spinning solution, so the diameter of the spun nanofiber will affect

That is, when the temperature of the spinning region is relatively high and the viscosity of the solution is low, nanofibers having a relatively thin fiber diameter are made, and when the viscosity of the solution is high because the temperature is relatively low, nanofibers having a relatively thick fiber diameter are made.

The concentration measuring device for measuring the concentration has a contact type and a non-contact type that directly contact the solution. For the contact type, a capillary type concentration measuring device, a disk (DISC) type concentration measuring device, etc. can be used. A density measuring device or a density measuring device using infrared rays may be used.

The heating device of the present invention may be composed of an electric heater, a hot water circulation device or a hot air circulation device, and in addition, devices capable of increasing the temperature in the same range as the above devices may be borrowed.

As an example of the heating device, an electric heater may be used in the form of a hot wire, and a coil-type hot wire may be mounted inside the plate or tube body of the nozzle block, which is also deformable in the form of a jacket. In addition, it is possible to have a configuration of a linear hot wire and a U-shaped pipe.

The heating device as described above may be provided in any one or more of a nozzle block for spinning a polymer spinning solution, a tank for storing a polymer spinning solution, and an overflow system.

As the cooling device of the present invention, cooling means including a chilling device may be used, and a means for maintaining a certain viscosity of the polymer spinning solution is generally applicable. The cooling device may be provided in any one or more of the nozzle block, the tank, and the overflow system in the same way as the heating device, and is used to maintain a certain viscosity of the polymer spinning solution.

On the other hand, the viscosity of the polymer spinning solution of the present invention is preferably 1,000 to 5,000 cps, more preferably 1,000 to 3,000 cps. When the viscosity is 1,000 cps or less, the quality of the nanofibers electrospun and laminated is poor, and when the viscosity is 3,000 cps or more, the discharge of the polymer spinning solution from the nozzle during electrospinning is not easy, and the production speed is slowed down.

In the present invention, the viscosity of the polymer spinning solution is constant as the electrospinning progresses, so the spinning efficiency is excellent during electrospinning, and at the same time, the concentration of the polymer spinning solution increases, and the amount of solids excluding the solvent among the nanofibers accumulated in the collector increases. This has the effect of increasing productivity.

In addition, the amount of residual solvent in the nanofibers using electrospinning is less than in the case of using conventional electrospinning, so that nanofibers of excellent quality can be manufactured.

In addition, the temperature control control device of the present invention is a manual type that allows the operator to control the viscosity of the polymer spinning solution through the temperature control of the nozzle block or the spinning solution main tank by measuring the concentration of the intermediate tank offline, and at the same time, It includes an automatic type that can adjust the temperature of the solution according to the concentration measurement through an online automatic control system.

Since the electrospinning device as described above is provided with a temperature control device, it is possible that the temperature for performing electrospinning is 20 to 60°C. When the temperature for electrospinning is raised to 60° C., the amount of polymer solids in the polymer spinning solution can be increased, and thus productivity can be increased. However, when it exceeds 60 ℃, the viscosity of the spinning solution is too high, and the radioactivity is rather deteriorated. In addition, the electrospinning condition in the present invention is preferably a humidity of 40% or more.

On the other hand, as the material of the polymer spinning solution usable in the present invention, polylactic acid (PLA), polycarbonate (PC), polyvinylidene fluoride (PVDF), polypropylene (PP), polyethylene terephthalate (PET), polyether Sulfone (PES), polyamide, polyvinyl acetate, polymethyl methacrylate, polyacrylonitrile (PAN), polyurethane (PUR), polybutylene terephthalate (PBT), polyvinyl butyral, polyvinyl chloride, Examples include polyethyleneimine, polyvinyl acetate (PVAc), polyethylene naphthalate (PEN), polyvinyl alcohol (PVA), polyethyleneimide (PEI), polycaprolactone (PCL), and polylactic acid glycerol (PLGA). However, the present invention is not limited thereto.

In the present invention, it is preferable to use a biodegradable polymer as the material of the polymer.

The biodegradable polymer used in the present invention is PHB (poly-hydroxy butyrate), PHBV (3-hydroxy butyrate-co-3-hydroxy valerate), PGA [(poly)glycolic acid], PLA [(poly) lactic acid], PLGA (polylactic-co-glycolic acid), PCL [poly(e-caprolactone)], polydioxanone, polyorthoester, polyanhydride, γ-PGA, gelatin ), silk, collagen, cellulose, alginic acid and hyaluronic acid may be selected from the group consisting of.

On the other hand, the polymer spinning solution is a solution in which the polymer, which is a synthetic resin material capable of electrospinning, is dissolved in a suitable solvent, and the type of solvent is not limited as long as it can dissolve the polymer, for example, phenol, formic acid, sulfuric acid, m-cresol, tifluoroacetandhydride/dichloromethane, water, N-methylmorpholine N-oxide, chloroform, tetrahydrofuran and aliphatic ketone groups methylisobutylketone, methylethylketone, aliphatic hydroxyl group group m-butyl alcohol, isobutyl alcohol, isopropyl alcohol, methyl alcohol, ethanol, aliphatic compounds hexane, tetrachloroethylene, acetone, glycol group, propylene glycol, diethylene glycol, ethylene glycol, halogen compound group, trichloro Ethylene, dichloromethane, aromatic compound group toluene, xylene, alicyclic compound group cyclohexanone, cyclohexane and ester group n-butyl acetate, ethyl acetate, aliphatic ether group butyl cellosalve, acetic acid 2- Ethoxyethanol, 2-ethoxyethanol, dimethylformamide, dimethylacetamide, etc. can be used as amides, and a plurality of types of solvents can be mixed and used. It is preferable to contain additives, such as an electroconductivity improving agent, in a spinning liquid. A preferred solvent is dimethylacetamide. The additive is preferably tetrabutylammonium perchlorate (TBAP).

The content of the polymer in the polymer spinning solution is preferably 10 to 35% by weight. If the content of the polymer is less than 10% by weight, the density of the nanofiber layer may not be uniform, and if it is 35% by weight, there is a problem in that the radioactivity is lowered.

Hereinafter, a method for manufacturing a nanomembrane using the electrospinning device will be described.

A method of manufacturing a nano-membrane according to an embodiment comprises: supplying a spinning solution obtained by dissolving a polymer in an organic solvent to a spinning solution main tank of an electrospinning apparatus; The spinning liquid supplied to the spinning liquid main tank is quantitatively supplied into a plurality of nozzles located in the nozzle block through a metering pump; and each spinning solution supplied from each nozzle is spun on a collector spaced apart from the nozzle at a predetermined distance through the nozzle to form a nanofiber layer. In this case, the nozzle block has a structure in which a plurality of nozzle plates and nozzle tubes are arranged, and the plurality of nozzles located on the nozzle plate and the nozzle tube are movable up, down, left and right.

First, a polymer spinning solution in which a polymer is dissolved in an organic solvent is supplied to a spinning solution main tank connected to a unit of an electrospinning device, respectively, and the polymer spinning solution supplied to the spinning solution main tank is a nozzle to which a high voltage is applied through a metering pump It is continuously metered into multiple nozzles of the block. The polymer spinning solution supplied from each nozzle is electrospun and focused on a collector to which a high voltage is applied through the nozzle to form a laminated nanofiber layer.

In this case, the electrospinning may be performed under a voltage of 40 to 60 kV, a fluid velocity of 0.1 to 5 ml/h, a spinning distance of 3 to 50 cm, room temperature conditions, and relative humidity of 30 to 50%. In addition, the content of the polymer in the spinning solution may be 10 to 35% by weight.

The long sheet on which the nanofiber layer is laminated in each unit of the electrospinning device is transported by the rotation of the supply roller operated by the driving of the motor and the auxiliary transport device driven by the rotation of the supply roller, and the above process is repeated. While the polymer nanofiber layer is continuously electrospun and laminated on the long sheet.

The thickness of the nanofiber layer prepared as described above is preferably 0.1 to 20 μm, and the basis weight is preferably 1 to 10 g/m ² . When the thickness of the nanofiber layer is less than 0.1 μm, it is difficult to peel from the support, and when it exceeds 20 μm, there is a problem of poor processability and economical efficiency, and when the basis weight of the nanofiber layer is ^{less than 1 g/m 2} , the filtration efficiency is reduced, 10 g / If it exceeds m ² , there is a problem of poor processability and economical efficiency.

On the other hand, two or more different polymer spinning solutions may be spun within one nozzle plate (or nozzle tube), and different types of polymer spinning solutions may be spun for each nozzle plate (or nozzle pipe).

In this case, the manufacturing method of the nano-filter according to an embodiment comprises the steps of dissolving a polymer in an organic solvent to prepare first and second spinning solutions; forming a first nanofiber layer by electrospinning the first spinning solution using an electrospinning device; manufacturing a nanofilter by electrospinning the second spinning solution on the first nanofiber layer to form a second nanofiber layer; and removing the residual solvent of the nano-filter by passing the nano-filter through a multi-stage heating roll, and adhering the first nano-fiber layer and the second nano-fiber layer.

In addition, in the present invention, it is also possible to continuously laminate two or more nanofiber layers having different fiber diameters on the collector by varying the spinning conditions for each unit of the electrospinning device.

Specifically, nanofiber layers having different fiber diameters can be formed by adjusting the distance between the nozzle and the collector. When the type of spinning solution and the applied voltage strength are the same, it is possible to form two nanofiber layers with different fiber diameters according to the principle that the shorter the spinning distance, the larger the fiber diameter, and the longer the spinning distance, the smaller the fiber diameter. do. And, by adjusting the concentration and viscosity of the spinning solution, adjusting the moving speed of the long sheet, or using different nozzles, it is also possible to make a difference in fiber diameter.

* Hereinafter, the present invention will be described in detail through examples. However, the following examples are merely illustrative of the present invention, and the present invention is not limited by the following examples.

[Example 1]

A spinning solution obtained by dissolving 15 wt% of polylactic acid (PLA) in methylene chloride was prepared and put into a spinning solution main tank connected to an electrospinning device. At this time, the nozzle block of the electrospinning apparatus used a structure in which two nozzle plates and three nozzle tubes are alternately arranged.

In the front end block, electrospinning was performed under the conditions of 15 cm distance between electrode and collector, applied voltage 40 kV, spinning solution flow rate of 0.1 mL/h, and room temperature and humidity of 40% to form the first PLA nanofiber layer with an average fiber diameter of 300 nm. formed. Then, in the rear end block, electrospinning was performed under the conditions of 40 cm distance between the electrode and the collector, 40 kV of applied voltage, 0.1 mL/h of spinning solution flow rate, and 40% of room temperature and humidity, and the average diameter of the fibers on the first PLA nanofiber layer. A nano-membrane was prepared by forming a second PLA nanofiber layer of 150 nm.

Thereafter, the prepared nano-membrane was passed through a multi-stage heating roll to remove the residual solvent of the nano-membrane, and at the same time, the first PLA nano-fiber layer and the second PLA nano-fiber layer were attached to each other to finally prepare a nano-membrane.

[Example 2]

A first spinning solution in which polylactic acid (PLA) was dissolved in methylene chloride at 15% by weight and a second spinning solution in which polylactate-co-glycolate (PLGA) was dissolved in methylene chloride by 15% by weight were prepared. At this time, the nozzle block of the electrospinning apparatus used a structure in which two nozzle plates and three nozzle tubes were alternately arranged, and the first spinning liquid was put into the spinning liquid tank connected to the nozzle plate, and the nozzle tube was connected The second spinning solution was put into the spinning solution tank.

After that, using the first spinning solution, electrospinning was performed under the conditions of 15 cm distance between the electrode and the collector, applied voltage 40 kV, spinning solution flow rate of 0.1 mL/h, and room temperature and humidity of 40%, PLA having an average diameter of fibers of 300 nm A nanofiber layer was formed. In addition, using the second spinning solution, the distance between the electrode and the collector is 40 cm, the applied voltage is 40 kV, the spinning solution flow rate is 0.1 mL/h, and the electrospinning is performed under the conditions of 40% room temperature and humidity. A nanofiber layer was formed to prepare a nanomembrane.

Thereafter, the prepared nano-membrane was passed through a multi-stage heating roll to remove the residual solvent of the nano-membrane, and at the same time, the PLA nano-fiber layer and the PLGA nano-fiber layer were adhered to prepare a final nano-membrane.

[Comparative Example 1]

A spinning solution obtained by dissolving 15 wt% of polylactic acid (PLA) in methylene chloride was prepared and put into a spinning solution main tank connected to electrospinning. At this time, the nozzle block of the electrospinning apparatus used a structure in which a plurality of nozzle plates were arranged. Electrospinning was performed under conditions of 15 cm distance between the electrode and the collector, an applied voltage of 40 kV, a spinning solution flow rate of 0.1 mL/h, and room temperature and humidity of 40% to prepare a nanomembrane having an average fiber diameter of 300 nm.

[Comparative Example 2]

A nanomembrane having an average fiber diameter of 150 nm was prepared in the same manner as in Comparative Example 1, except that the distance between the electrode and the collector was adjusted to 40 cm.

[Experimental example]

The physical properties of the nanomembrane prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Table 1 below.

1) Standard deviation of basis weight

Six test pieces of 200 mm (MD) Х 50 mm (CD) were taken from the nanomembrane prepared in Examples and Comparative Examples, respectively. Next, the mass (g) of each of the sampled specimens was measured using an electronic balance on the upper plate, and the average value of the mass of each specimen was obtained. From the obtained average value, it was converted to mass per 1 sm (g), and the first decimal place was rounded off to give the basis weight [gsm] of the nanomembrane sample for each part. Thereafter, the standard deviation of the basis weight of the six-point test piece was calculated, and the results are shown in Table 1.

	Example 1	Example 2	Comparative Example 1	Comparative Example 2
basis weight standard deviation	0.12	0.27	0.74	0.89

As can be seen from Table 1, it was found that the nanomembrane prepared according to the example of the present invention had a uniform basis weight compared to the comparative example, and thus the uniformity was improved.

Although the above has been described with reference to the preferred embodiment of the present invention, those skilled in the art or those having ordinary knowledge in the technical field will not depart from the spirit and technical scope of the present invention described in the claims to be described later. It will be understood that various modifications and variations of the present invention can be made without departing from the scope of the present invention.

Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Claims (7)

1. supplying a spinning solution obtained by dissolving a polymer in an organic solvent to the spinning solution main tank of the electrospinning device;

   The spinning liquid supplied to the spinning liquid main tank is quantitatively supplied into a plurality of nozzles located in the nozzle block through a metering pump; and

   Each spinning solution supplied from each nozzle is spun on a collector spaced apart from the nozzle at a predetermined distance through the nozzle to form a nanofiber layer,

   The nozzle block has a structure in which a plurality of nozzle plates and nozzle tubes are arranged, and the nozzle plate and the nozzle tube are movable vertically, horizontally and horizontally, respectively.
2. According to claim 1,

   The nozzle block is a method of manufacturing a nano-membrane having a structure in which two nozzle plates and three nozzle tubes are alternately arranged.
3. According to claim 1,

   The plurality of nozzles disposed on the nozzle plate and the nozzle tube are the same or different in diameter from each other.
4. According to claim 1,

   The electrospinning device is a water removal device that collects the spinning solution that overflowed without being spun from the nozzle in the overflow spinning solution storage tank, and transfers the solvent containing moisture in the spinning solution to the receiving tank through vacuum, temperature control, and agitation. A method of manufacturing a nanomembrane comprising a.
5. According to claim 1,

   The nozzle plate and the nozzle pipe each include a metering pump and a control valve,

   A method of manufacturing a nano-membrane in which the spinning solution supplied to each nozzle plate and the nozzle tube is the same or different from each other.
6. According to claim 1,

   The polymer is polylactic acid (PLA), polycarbonate (PC), polyvinylidene fluoride (PVDF), polypropylene (PP), polyethylene terephthalate (PET), polyethersulfone (PES), polyamide, polyvinyl acetate , polymethyl methacrylate, polyacrylonitrile (PAN), polyurethane (PUR), polybutylene terephthalate (PBT), polyvinylbutylral, polyvinyl chloride, polyethyleneimine, polyvinyl acetate (PVAc), polyethylene Naphthalate (PEN), polyvinyl alcohol (PVA), polyethylene imide (PEI), polycaprolactone (PCL) and polylactic acid glycerol acid (PLGA) method of manufacturing one or more kinds of nano-membrane selected from the group consisting of .
7. A nanomembrane prepared by the manufacturing method according to any one of claims 1 to 6, having a thickness of 0.1 to 20 μm, and a basis weight of 1 to 10 g/m ² .

Images