KR101834405B1 - Both sides substrate nanofiber web for excellent adhesion property, a separator using it and its manufacturing method - Google Patents

Abstract

The present invention relates to a thermoplastic polyurethane base; Polymer nanofibers having a basis weight of 0.1 to 2 g / m < 2 > and laminated by electrospinning the polymer spinning solution on the thermoplastic polyurethane base; And an inorganic polymer nanofiber having a basis weight of 0.1 to 2 g / m < 2 > laminated by electrospinning on a thermoplastic polyurethane base material on the back surface where the polymer nanofibers are not laminated. Double-sided nanofiber web.
The nanofiber web according to the present invention is advantageous in that the thermoplastic polyurethane nonwoven fabric can be melted partially in a high temperature laminating environment due to its thermoplastic property and can be used as an adhesive without a separate adhesive by using a thermoplastic polyurethane nonwoven fabric as a base material. Further, by forming the nanofibers on both surfaces of the substrate by lamination, the heat resistance is further improved and the filtering efficiency of the filter is excellent. In addition, an electrospinning device for spinning nanofibers is provided with several blocks, so that mass production of nanofibers is possible.

Description

[0001] The present invention relates to a double-sided nanofiber web having improved adhesion, a separation membrane using the same, and a method for manufacturing the same,

The present invention relates to a double-sided substrate nanofiber web having improved adhesion, a separation membrane using the same, and a method of manufacturing the same. The nanofiber is formed by electrospinning a polymer spinning solution and an inorganic polymer spinning solution on both sides of a thermoplastic polyurethane substrate, Improved double-sided nanofiber webs and methods of making the same.

In general, a filter is a filtration device for filtering foreign matters in a fluid, and is divided into a liquid filter and an air filter. Among them, the air filter has been developed as a clean room where the biologically harmful substances such as particulate matter, germs and molds, bacteria and the like are completely removed from the air in order to prevent the deterioration of the high- Demand is gradually increasing as the usage area spreads day by day. Cleanroom applications are widely used in semiconductor manufacturing, computer equipment assembly, tape manufacturing, printing painting, hospitals, pharmaceutical manufacturing, food processing plants, agriculture, forestry and fisheries.

The air filter forms a porous layer of microporous structure on the surface of the filter media so that the dust does not penetrate into the filter media and performs filtration. However, the large particles are formed by the filter cake on the surface of the filter material, and the fine particles pass through the primary surface layer and gradually accumulate in the filter material, thereby blocking the pores of the filter. As a result, large particles and fine particles, which trap the pores of the filter, increase the pressure loss of the filter and deteriorate the life of the filter. In addition, conventional filter media have difficulties in filtering fine particles having a size of 1 μm or less .

On the other hand, the efficiency of the conventional air filter is measured by the principle that the static electricity is given to the fibrous aggregate constituting the filter filter material and the particles are collected by the electrostatic force. However, the European air filter classification standard EN779 recently decided to exclude the filter efficiency due to the electrostatic effect in 2012, so that the actual efficiency of the conventional filter was lowered by more than 20%. In addition, due to the adverse effect of glass fiber, which has been used as a material of conventional heat resistant filter, on the environment, in Europe and the United States, the use of glass fiber is regulated for environmental stability.

In order to solve the above-mentioned problems, various methods of manufacturing nano-sized fibers and applying them to filters have been developed. When nanofibers are implemented in a filter, they have a large specific surface area compared to conventional filter media having a large diameter, good flexibility for surface functional groups, and nanoparticle pore size, so that harmful fine particles and gas can be efficiently removed It was.

However, since the production cost of the filter using the nanofibers is large, and it is difficult to control the various conditions for production, it is difficult to mass-produce the filter. Therefore, the filter using the nanofiber is produced at a relatively low cost I can not. Furthermore, filters used in gas turbines, blast furnaces and the like are demanding heat resistance.

In addition, since the fine nanofibers have a disadvantage that the filter life is shortened due to high pressure loss when the filter is used, it is possible to effectively filter the fine particles by giving a gradient to the thickness of the nanofiber, and at the same time to alleviate filter damage due to pressure loss.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a substrate double-sided nanofiber web having improved adhesion by forming polymer nanofibers and inorganic polymers on both surfaces of a thermoplastic polyurethane substrate, and a method for producing the same.

In order to achieve the above object, the present invention provides a thermoplastic polyurethane base material, Polymer nanofibers having a basis weight of 0.1 to 2 g / m < 2 > and laminated by electrospinning the polymer spinning solution on the thermoplastic polyurethane base; And an inorganic polymer nanofiber having a basis weight of 0.1 to 2 g / m < 2 > laminated by electrospinning on a thermoplastic polyurethane base material on the back surface where the polymer nanofibers are not laminated. Double-sided nanofiber web.

The polymer spinning solution may be at least one selected from the group consisting of polypropylene (PP), polyethylene terephthalate (PET), polyvinylidene fluoride, nylon, polyvinylacetate, polymethylmethacrylate, polyacrylonitrile (PAN) ), Polybutylene terephthalate (PBT), polyvinyl butyral, polyvinyl chloride, polyethylene imine, polyolefin, polylactic acid (PLA), polyvinyl acetate (PVAc), polyethylene naphthalate (PEN) , Polyvinyl alcohol (PVA), polyethyleneimide (PEI), polycaprolactone (PCL), polylactic acid glycolate (PLGA), silk, cellulose and chitosan, The nanofiber is preferably formed by electrospinning a polymer selected from the group consisting of a silane group or a siloxane group alone polymer and a copolymer polymer of silane group or siloxane group .

It is preferable that the polymer nanofiber and the inorganic polymer nanofiber are formed in different weights in the transverse or longitudinal direction, respectively.

In addition, the nanofiber web is preferably used for a filter.

According to another aspect of the present invention, there is provided a method of manufacturing a web for electrospinning a polymer on both sides of a substrate, comprising the steps of: supplying a polymer spinning solution to a nozzle connected to a first block; supplying an inorganic polymer spinning solution to a nozzle connected to the second block; A step of electrospinning a polymer spinning solution on a thermoplastic polyurethane substrate to form a polymer nanofiber layer by lamination in a nozzle connected to the first block; And a step of successively electrospinning the inorganic polymeric spinning solution on the thermoplastic polyurethane base material on the back surface where the polymer nanofibers are not laminated in the nozzle connected to the second block to form the inorganic polymer nanofibers The present invention also provides a method of producing the improved substrate double-faced nanofiber web.

In this case, it is preferable that the electrospinning apparatus is a hybrid electrospinning apparatus that is designed as a combination of a bottom-up type and a top-down type, and the apparatus for electrospinning is a bottom-up or down-type electrospinning apparatus in which a collector- desirable.

In addition, it is preferable that the electrospinning device is electrospinning the polymer spinning solution at a high temperature of 45 to 120 DEG C through a nozzle using a temperature control device.

The polymer spinning solution and the inorganic polymer are the same as described above.

According to the configuration of the present invention, the objects of the present invention described above can be achieved. Specific effects according to the configuration of the present invention are as follows.

The filter according to the present invention is advantageous in that the thermoplastic polyurethane nonwoven fabric is used as a base material, and can be partially melted in a high temperature laminating environment through its thermoplastic property, so that it can serve as an adhesive without a separate adhesive. Further, by forming a laminate of nanofibers on both surfaces of the substrate, the heat resistance is further improved and the filtering efficiency of the filter is excellent. In addition, an electrospinning device for spinning nanofibers is provided with several blocks, so that mass production of nanofibers is possible.

Also, the nanofibers and filters of the present invention can be used as separators and are preferable. Since the separator made of the nanofibers produced through electrospinning has porosity, the separator prepared from the separator is preferably used as a separator because of its excellent cell performance, and desorption occurs between the substrate and the nanofibers Therefore, it is possible to use a stable separation membrane.

1 is a schematic view of a nanofiber web on both sides of a substrate with improved adhesion.
2 is a schematic diagram of a hybrid electrospinning apparatus.
3 is a schematic view of the process of the electrospinning apparatus.
Fig. 4 is a schematic process diagram of a block of an electrospinning device. Fig.
5 is a schematic view of an apparatus for measuring thickness of an electrospinning device.
6 is a schematic view of a nozzle block and a nozzle of an electrospinning device.
7 is a diagram of an electrospinning apparatus having an overflow system and a viscosity control system used in the present invention.
Fig. 8 is a front sectional view showing a tubular body equipped with a coil-shaped heating wire in an electrospinning apparatus having a temperature control device used in the present invention.
9 is a cross-sectional view taken along the line A-A 'in FIG.
10 is a front sectional view showing a tubular body equipped with a linear heating wire in an electrospinning device equipped with a temperature control device according to the present invention.
11 is a cross-sectional view taken along the line B-B 'in FIG.
12 is a front sectional view showing a tubular body equipped with a U-shaped pipe in an electrospinning apparatus having a temperature control device used in the present invention.
13 is a cross-sectional view taken along the line C-C 'in FIG.
14 is a plan view showing a state in which the nozzle in the spinning solution unit of the present invention is turned on and off in the CD direction.
Fig. 15 is a plan view showing a process of electrospinning the basis weight of the polymer in the CD direction according to the operation of the nozzle in the spinning solution unit as shown in Fig. 14. Fig.
16 is a plan view showing a state in which the nozzle in the spinning solution unit of the present invention is turned on and off in the MD direction.
17 is a schematic diagram schematically showing an electrospinning device including a bottom-up electrospinning device and a top-down electrospinning device according to an embodiment of the present invention.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is to be noted that like elements in the drawings denote like elements wherever possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

First, an electrospinning device used in the present invention will be described with reference to the drawings.

Fig. 1 is a schematic diagram of a double-sided nanofiber web with improved adhesion of the present invention, Fig. 2 is a schematic diagram of a hybrid electrospinning device, Fig. 3 is a schematic view of the process of the electrospinning device used in the present invention, Fig. 5 is a schematic view of an apparatus for measuring thickness of an electrospinning device used in the present invention, and Fig. 6 is a schematic view of a nozzle block of the electrospinning device used in the present invention and a nozzle Fig.

2, the combined electrosupply apparatus 100 includes a bottom-up electrospinning apparatus 110 and a top-down electrospinning apparatus 130. The bottoms electrospinning apparatus 110 and the top- The electrospinning apparatuses 130 are arranged alternately and continuously in the horizontal direction.

The bottom-up electrospinning device 110 and the top-down electrospinning device 130 are connected to the spinning liquid main tanks 111 and 131 and the spinning liquid main tanks 111 and 131 in which a polymer spinning solution (not shown) (Not shown) for supplying a polymeric spinning liquid filled in the main spinning liquid main tanks 111 and 131 and a polymer spinning solution in the spinning liquid main tanks 111 and 131, And collectors 117 and 137 spaced apart from the nozzles 115 and 135 by a predetermined distance in order to accumulate the polymer solution for spraying located at the lower ends of the nozzles 115 and 135, And a voltage generator (not shown) for generating a voltage to the collectors 117 and 137.

The mixed electrospinning apparatus 100 according to the present invention has a structure in which the spinning liquid filled in the spinning liquid main tank 111 of the bottom-up electrospinning apparatus 110 is supplied with a high voltage through the metering pump And the polymer spinning solution supplied to the nozzle 115 is radiated and focused on the collector 117 with a high voltage applied thereto through the nozzle 115 to form a nanofiber web And the formed nanofiber is embossed or needle punched to produce the nanofiber.

A support body 121 on which nanofibers (not shown) are laminated by spraying the polymer spinning solution from the bottom-up electrospinning device 110 and the top-down electrospinning device 130 is mounted on the front end of the mixed electrospinning device 100, And a winding roller 118 for winding the support 121 on which nanofibers are laminated is provided at the rear end.

Here, the support 121, on which the polymer spinning solution of the bottom-up electrospinning device 110 and the top-down electrospinning device 130 are laminated, is preferably made of nonwoven fabric or fabric, but is not limited thereto.

At this time, the bottom-up electrospinning device 110 and the top-down electrospinning device 130 are arranged symmetrically with respect to the collectors 117 and 137 in the upward and downward directions, respectively. That is, in the bottom-up electrospinning device 110, the collector 117 is located at the top of the nozzle 115, and the top-down electrospinning device 130 is located at the bottom of the nozzle 135.

Electrode directions of the collectors 117 and 137 provided in the bottom-up electrospinning device 110 and the top-down electrospinning device 130 are opposite to each other. That is, the direction of the electrodes of each collector 117 provided in each of the bottom-up electrospinning devices 110 and 110 'is set such that the top surface of the collector 117 faces the nozzle block 113 having the plurality of nozzles 115 And the direction of the electrodes of each collector 137 provided in each of the down-type electrospinning devices 130 and 130 'is the same as that of the lower part of the collector 137 so as to face the nozzle block 133 having the plurality of nozzles 135. [ Plane.

On both ends of each of the collectors 117 and 137 are provided conveyance rollers 119 and are stacked on the collectors 117 and 137 via the conveyance rollers 119 to form nano- (13) is transported in the horizontal direction. That is, the polymer spinning solution injected from the nozzle 115 of the bottom-up electrospinning device 110 is laminated on the support 121 of the collector 117, and the nanofibers produced by the collector 115 of the bottom- And a transfer roller 119 for moving the transfer roller 119 horizontally onto the transfer rollers 137 and for moving the process repeatedly and continuously are provided at both ends of the collectors 117 and 137, respectively.

The polymer spinning liquid filled in the spinning liquid main tank 111 of the bottom-up electrospinning apparatus 110 is sprayed onto the support 121 of the collector 117 through the nozzle 115, The nanofibers are formed on the supporter 121 of the collector 117 and the nanofibers are stacked on the supporter 121. The nanofibers are stacked on the supporter 121 through the transport rollers 119, The polymer solution is transferred to the collector 137 of the top-down electrospinning device 130 and the polymer solution is injected into the polymer solution tank 130, which is filled in the spinning solution main tank 131 of the top-down electrospinning device 130, The bottom-up electrospinning apparatus 110, 110 'and the top-down electrospinning apparatus 130, 130' are alternately arranged in succession such that the use liquid is sprayed through the nozzle 135, and the above- The final product is produced.

In one embodiment of the present invention, a bottom-up electrospinning device 110 is provided at the front end of the composite electrospinning device 100, and a top-down electrospinning device 130 is provided at a rear end of the bottoms electrospinning device 110 The bottom-up type electrospinning device 110 and the bottom-up type electrospinning device 130 and 130 'are sequentially arranged in this order. However, the bottom type electrospinning device 130 is installed at the end of the combined type electrospinning device 100, A bottom-up type electrospinning device 130 and 130 'and a bottom-up type electrospinning device 110 and 110', in which a bottom-up type electrospinning device 110 is provided at the rear end of the bottom- It is also possible to arrange them continuously.

In addition, two or more bottom-up electrospinning apparatuses 110 are continuously arranged at the tip of the composite electrospinning apparatus 100, and two or more top-down electrospinning apparatuses 130 are continuously arranged Or two or more top-down electrospinning apparatuses 130 may be successively arranged at the front end, and two or more bottom-up electrospinning apparatuses 110 may be continuously arranged at the rear end thereof.

The nanofibers produced while passing through the bottom-up electrospinning apparatus 110 and the top-down electrospinning apparatus 130 of the composite electrospinning apparatus 100 according to the present invention have the above- The polymeric spinning solution is injected through the nozzles 115 and 135 of the spinning device 110 and the top-down electrospinning device 130 so that the nanofibers are stacked on the lower surface and the upper surface of the support 121 on the collectors 117 and 37, The polymeric spinning solution injected from the nozzles 115 and 235 of the bottom-up electrospinning device 110 and the top-down electrospinning device 130 is laminated on the support 121 to form a plurality of nanofibers, Fiber products are produced.

A support body 121 on which nanofibers (not shown) are laminated by spraying the polymer spinning solution from the bottom-up electrospinning device 110 and the top-down electrospinning device 130 is mounted on the front end of the mixed electrospinning device 100, And a winding roller 118 for winding the support 121 on which nanofibers are laminated is provided at the rear end.

According to a preferred embodiment of the present invention, a first polymer spinning solution prepared by dissolving a first polymer packed in a first supply device in an organic solvent is electrospun onto a top surface of a substrate to form a first nanofiber; And a second polymer spinning solution prepared by dissolving a second polymer packed in a second supply device in an organic solvent, and electrospinning the second polymer spinning solution on the lower surface of the base material, thereby laminating the second nanofibers. do.

The filled solution of the first feeding device may or may not be the same solution in the second feeding device. In addition, two or more feeding devices are possible.

3 and 4 are schematic diagrams of a typical continuous electrospinning apparatus. (Not shown) for supplying a flushing solution in which the flushing liquid is filled in the main tank (not shown) and the polymer flushing liquid filled in the flushing liquid main tank, a polymer flushing liquid is discharged through the metering pump And a collector 4 spaced apart from the nozzle 2 by a predetermined distance in order to accumulate the discharged polymer spinning solution. The nozzle block 2 includes a plurality of pin-shaped nozzles 2, And a case (8) comprising a block (20) for accommodating therein a voltage generating device (1) for generating a voltage to the collector, and a conductor or a negative conductor surrounding the block (20).

In the present invention, one spinning liquid main tank (not shown) is shown as one. However, in the case where the spinning liquid is composed of two or more spinning liquids, two or more main spinning liquid main tanks may be provided, It is also possible to divide into two or more spaces and supply two or more polymer spinning solution filled in each divided space.

In the present invention, the electrospinning device 10 uses a bottom-up electrospinning device for spraying the spinning solution in the upward direction.

On the other hand, in the embodiment of the present invention, a bottom-up electrospinning apparatus for spraying the spinning liquid in the upward direction with the electrospinning apparatus is used, but a top-down electrospinning apparatus for spraying the spinning liquid in the downward direction or a combination of a bottom- Combined electric radiators used together may be used, but are not limited thereto.

With the above structure, the electrospinning apparatus 10 is configured such that the spinning liquid filled in the spinning liquid main tank in the block 20 continuously flows into the plurality of nozzles 2 to which a high voltage is applied through the metering pump And the spinning solution of the polymer supplied to the nozzle 2 is radiated and focused on the collector 13 having a high voltage through the nozzle 2 to form nanofibers (not shown) The fibers are laminated to produce a filter.

In the front end of the electrospinning device 10, there is provided a feed roller 11 for feeding a long sheet on which nanofibers are laminated by spraying a polymer spinning solution in each block 20, Up roller 12 for winding the sheet.

In the present invention, the filter sheet 5 is used as a long sheet and the polymer spinning solution is sprayed on the filter substrate 5 to form nanofibers .

In the embodiment of the present invention, the thermoplastic polyurethane base 5 is used as a long sheet, but a release or nonwoven fabric may be used, but the present invention is not limited thereto.

The electrospinning device of each block 20 is installed with respect to the collector 4 in the advancing direction a of the radiation. An auxiliary belt 6 is provided between each of the collectors 4 and the filter substrate 5 and is integrated with each of the collectors 4 through the auxiliary belts 6 to form nano- (5) is transported in the horizontal direction. That is, the auxiliary belt 6 rotates in synchronization with the feed speed V of the filter base material, and has the auxiliary belt roller 7 for driving the auxiliary belt 6. The auxiliary belt roller 7 is an automatic roller having at least two frictional forces. Since the auxiliary belt 6 is provided between the collector and the filter substrate 5, the filter substrate 5 is smoothly conveyed without being attracted to the collector to which the high voltage is applied.

The spinning liquid filled in the spinning liquid main tank in the block 20 of the electrospinning device 10 is sprayed onto the filter substrate 5 located on the collector 4 through the nozzle 2 And the spraying liquid sprayed on the filter substrate 5 is accumulated to form a laminate of nanofibers. The auxiliary belt 6 is driven by the rotation of the auxiliary belt rollers 7 provided on both sides of the collector 4 to transfer the filter base material 5 to the blocks 20 at the rear end of the electrospinning device 10 ) So as to repeatedly perform the above-described process.

6, the spinning liquid is supplied to the nozzle block 2 through a plurality of nozzles 2 arranged upward from the discharge port, a tube 43 composed of a row of nozzles 2, a spinning liquid storage tank 44, And a spinning liquid circulating pipe (45).

First, the spinning liquid storage tank 44 connected to the spinning liquid main tank to receive and store the spinning solution is connected to the nozzle 2 through the spinning liquid circulating pipe 45 by the metering pump (not shown) And the spinning solution is supplied to the spinning solution. Here, the tube 43 having a plurality of nozzles 2 in a row is supplied with the same spinning solution from the spinning solution storage tank 44, but a plurality of spinning solution storage tanks are provided, It is also possible to supply and emit different kinds of spinning solutions for each tube 43 by storing them.

When radiated from the discharge port of the plurality of nozzles 2, the overflowed solution is moved to the overflow solution storage tank 41. The overflow solution storage tank 41 is connected to a spinning solution main tank (not shown) so that the overflow solution can be reused for spinning.

The main controller 30 controls the amount of spinning solution supplied to the nozzle block 3 and controls the voltage of the voltage supply device 1 for each block 20 And the conveying speed V of each block can be controlled according to the thickness of the nanofiber and the filter substrate measured by the thickness measuring device 9. [

The thickness measuring device 9 of the present invention is disposed opposite the filter substrate 5 located at the front end and the rear end of the block 20 and having the nanofibers stacked therebetween. The thickness measuring device 9 is connected to the main controller 30 for adjusting the radiation conditions of the electrospinning device 10 so that the thickness measuring device 9 measures the thickness of the nanofiber and the filter substrate 5 The main controller 30 controls the conveying speed V of each block 20 on the basis of one value. For example, when the deviation of the thickness of the discharged nanofibers is thinly measured for each block 20 in the electrospinning, the conveyance speed V of the block 20 located at the rear end is decreased, . Further, the main controller 30 increases the discharge amount of the nozzle block 3 and adjusts the intensity of the voltage of the voltage generator 1 to increase the discharge amount of the nanofibers per unit area to uniformly control the thickness of the nanofibers It is possible.

The thickness measuring device 9 is provided with a thickness measuring part consisting of a pair of ultrasonic longitudinal waves and a transverse wave measuring method for measuring the distance from the nanofiber on which the nanofibers are laminated to the filter base 5 by an ultrasonic measuring method , And the thickness of the nanofibers and the filter substrate 5 is calculated on the basis of the distance measured by the pair of ultrasonic measuring devices, as shown in Fig. More specifically, the ultrasonic longitudinal wave and the transverse wave are projected to the filter substrate 5 on which the nanofibers are laminated, and the time during which each ultrasonic signal of the longitudinal wave and the transverse wave reciprocates on the filter base 5, From the predetermined arithmetic expression using the propagation time of the measured longitudinal waves and transverse waves and the temperature constants of longitudinal and transverse wave propagation speeds and propagation speeds at the reference temperature of the filter substrate 5 on which the nanofibers are stacked, It is a thickness measuring device that calculates the thickness of a dead body.

The electrospinning device 10 used in the present invention is configured such that when the thickness deviation P of the nanofiber is less than a predetermined value, the feed velocity V is not changed from the initial value, , It is possible to control the feed speed V to be changed from the initial value, so that it becomes possible to simplify the control of the feed speed V by the feed speed V control device. In addition to the control of the conveying speed V, the discharge amount and the voltage intensity of the nozzle block 3 can be adjusted. When the thickness deviation P is less than the predetermined value, the discharge amount of the nozzle block 3 and the intensity of the voltage It is possible to control the amount of discharge and the intensity of the voltage of the nozzle block 3 to be changed from the initial value when the deviation amount P is equal to or larger than the predetermined value without changing the initial value, It becomes possible to simplify control of the discharge amount and the intensity of the voltage.

The block 20 of the electrospinning device 10 is divided into a front end block 20a located at the front end portion and a rear end block 20b located at the rear end portion according to the radiation position. In the embodiment of the present invention, the number of blocks is limited to two, but it is also possible to have two or more blocks.

In the present invention, the same polymeric spinning solution is radiated in each of the blocks 20a and 20b, but it is also possible to spin different kinds of polymer spinning solutions for each block, and two or more different It is also possible that the polymer spinning solution is radiated. When at least two different kinds of spinning solutions are supplied and radiated for each block 20, it is possible that the polymer nanofibers of different kinds are successively laminated.

In addition, it is also possible to manufacture hybrid nanofibers by constituting two or more polymer types of the spinning solution to be used.

 It is also possible to continuously laminate nanofibers having different fiber thicknesses by varying the intensity of the voltage applied to each block 20. In a block 20, the number of nozzles 2 located in the nozzle block 3 It is also possible to form a hybrid nanofiber in which two or more polymers are electrospun and laminated.

On the other hand, a laminating device 19 is provided at the rear end of the electrospinning device 10 of the present invention. The laminating device 19 applies heat and pressure to the filter base material on which the nanofibers are laminated, that is, the nanofiber filter is wound on the winding roller 12 to form a nanofiber filter.

The nanofibers produced as shown in FIG. 1 by electrospinning by the electrospinning method have a different lamination of nanofibers according to the direction of air flow.

When the filter using the nanofibers of the present invention is implemented, the polymer spinning solution is electrospun in the air inlet direction of the substrate, and the inorganic polymer spinning solution is electrospun in the air exhaust direction.

More simply stated, when the upper surface of the substrate is in the air inflow direction, the polymer spinning solution is electrospun on the upper surface of the substrate, and the lower surface of the substrate is in the air discharge direction, so that nanofibers are formed on both sides of the substrate by electrospinning the inorganic polymer spinning solution It says.

Hereinafter, the thermoplastic polyurethane base used in the present invention will be described.

First, the polyurethane is a polymer of a urethane bond formed by the reaction of a polyisocyanate and a polyalcohol. Polyurethane is excellent in elasticity, abrasion resistance, and processability, and is widely used in industrial, consumer products, and parts. Since the properties of polyurethane vary depending on the type of polyurethane, selection of a product suitable for the application is important.

The polyurethane is classified into two types, thermoplastic polyurethane and thermosetting polyurethane. The thermoplastic polyurethane has excellent characteristics such as strength, formability, chemical resistance, oil resistance and wear resistance. BACKGROUND ART [0002] Flexible nonwoven fabrics made of thermoplastic polyurethane (hereinafter referred to as "TPU") have been used for applications including clothing, sanitary materials, and sporting goods materials due to their high elasticity, low residual strain and excellent air permeability. The thermoplastic polyurethane nonwoven fabric produced by the so-called melt-blow spinning method has excellent stretchability, flexibility and air permeability, and has been conventionally used as a side band of paper diapers, a base fabric of first-aid bandages, And the like, which are relatively soft and stretchable, such as sports apparel, stretch cotton pads, and the like.

The process for producing the thermoplastic polyurethane is well known. That is, it is prepared by reacting a linear polyol containing a hydroxy end group such as a polyester polyol or a polyether polyol with a diisocyanate compound containing an isocyanate group at both terminals, and optionally, a chain extender, a monoamine compound Terminal stopping agents, and other additives.

Examples of the polyol include various diols comprising a linear homo or copolymer such as a polyester diol, a polyether diol, a polyester amide diol, a polyacryl diol, a polythioester diol, a polythioether diol, a polycarbonate diol, ≪ / RTI > may be used. More specific examples include polyalkylene ether glycols such as polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, copolymer polyether glycol composed of tetramethylene group and 3-methyl tetra ketylene group.

As the diisocyanate compound serving as a hard segment, an aromatic, aliphatic or alicyclic diisocyanate is used, for example, 4,4'-diphenyl ketadiisocyanate, 1,3- and 1,4-cyclohexylene diisocyanate, 1,6-hexamethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, and the like, but are not limited thereto.

Examples of the chain extender include a diamine compound or a diol compound. Examples of the chain extender include a diamine compound such as methylene diamine, ethanol diamine, 1,2-propylene diamine and the like, and a diamine compound such as ethylene glycol, 1,3-propanediol, , Neopentyl glycol, and the like, but are not limited thereto.

Examples of the terminal terminating agent include monoamine compounds such as monoethanolamine, diethanolamine and diisopropylamine.

On the other hand, the number average molecular weight of the thermoplastic polyurethane is preferably 1,000 to 100,000.

In the present invention, such a thermoplastic polyurethane is used as a base material. The nonwoven fabric is produced by preparing a web (a state in which fibers are repeatedly laminated) and entangling the fibers physically and chemically together.

Typical nonwoven fabrication processes involve web formation and web bonding processes. The general process is used only for single-fiber nonwovens, and this process is not necessary because longwoven nonwovens use filaments by spinning. In the case of non-woven fabric, it is put in a compressed bale state, so that the nonwoven fabric must undergo the process of compressed fibers. The formation process of the web is a necessary process for forming the nonwoven fabric. The dry nonwoven fabric forms the web in the air, whereas the wet nonwoven fabric disperses the fibers to obtain the web. Therefore, in the dry nonwoven fabric, the arrangement of the fibers is mostly directional, but the wet nonwoven fabric has a random irregular arrangement of the fibers. However, the development of a random card machine for dry nonwovens also makes it possible to obtain a web having no directionality depending on its application.

As a method of forming the web, a spun bond method using long fibers produced by dissolving radiation from raw pellets, a dry method of forming a web by arranging short fibers in a predetermined direction in a card machine or the like, And a wet method in which the water is homogeneously dispersed and drained to form a web.

Methods for entangling the fibers include a thermal bond method in which a thermally soluble fiber is mixed with a web and a thermal roll is used, a chemical bond method in which a binder is bonded (adhered fat), a barb of a needle A needle punch method in which fibers can be entangled with each other, and a meltblown method capable of randomly forming a web by impacting filaments with high-pressure air at the time of producing the fibers and capable of producing a web having a diameter of 0.5 to 30 microns .

Among them, the thermoplastic polyurethane base used in the present invention is preferably produced by the meltblown method, the spunbond method and the needle punch method among the above methods. The principle of the meltblown method is a melt spinning method using a thermoplastic resin, in which a high-temperature and high-pressure airflow is introduced into the outlet of the spinning nozzle to stretch and open the fibers, and then the fibers are accumulated on a collecting conveyor. The nonwoven fabric by this method has an advantage of being excellent in flexibility, impermeability and insulation. Generally, a thermoplastic polyurethane nonwoven fabric is produced by a meltblown spinning method. A general method of meltblown spinning will be described below. That is, the molten thermoplastic polymer is fed to nozzle holes arranged in a row, the molten polymer is continuously extruded from the nozzle holes, the hot gas is jetted at high speed from the slits arranged on both sides of the nozzle hole group, The polymer extruded from the nozzle holes is thinned and cooled to form continuous filaments and then the continuous filament group is accumulated on a moving conveyor net or the like to adhere the filaments to each other by the self-adhesiveness of the filaments themselves.

On the other hand, the spunbond method is a method in which a raw material is spun and self-bonded by heat to form a nonwoven fabric. It is a technology for forming a web by spun polypropylene or polyethylene terephthalate mainly by self-adherence by heat, and there is an advantage that the fabric design is easy.

In addition, in the case of the needle punching method, fibers are physically manufactured by combining webs using special needles, and it is possible to diversify the thickness of the product by the number of punching of needles and the density of needles.

The thermoplastic polyurethane nonwoven fabric produced by such a nonwoven fabric manufacturing method is preferably used as the base material used in the present invention. The thermoplastic polyurethane nonwoven fabric substrate has a structure in which the pores are small and uniformly dispersed and distributed in spite of the fact that the surface area is very low, very thin, soft and soft, and has air permeability as well as excellent elongation and expansion characteristics. It is also possible to attach a thinner, soft and soft composite material when combined with other members in that it can be composed of a thin nonwoven fabric. The thermoplastic polyurethane has a melting point of 80 to 200 ° C. Therefore, there is an advantage that the thermal adhesiveness is good and can be used for thermal bonding after the heat treatment. On the other hand, the basis weight of the base material is preferably 10 to 150 g / m < 2 >. If the basis weight is less than 10 g / m < 2 >, the physical properties of the base material are deteriorated. If the basis weight exceeds 150 g / m & .

The thermoplastic polyurethane nonwoven fabric can be hydrophobic or hydrophilic, can be introduced in color, and can be partially melted in a high-temperature laminating environment due to its thermoplastic characteristics, so that the thermoplastic polyurethane non- There is a possible advantage.

On the other hand, as shown in FIG. 6, the electrospinning device of the present invention may include a temperature control device 60 for controlling viscosity to maintain fiber viscosity suitable for electrospinning.

As the temperature control device 60, it is possible to use a heating device capable of keeping the viscosity of the high-viscosity polymer solution reused through the overflow low and a cooling device capable of keeping the viscosity of the polymer solution having a relatively low viscosity high, .

In the temperature in the electrospinning region, the temperature of the region where the electrospinning occurs (hereinafter, referred to as the 'radiating region') changes the surface tension of the spinning solution by changing the viscosity of the spinning solution, . ≪ / RTI >

That is, when the temperature of the radiation region is relatively high, the nanofiber having a relatively small fiber diameter is produced when the viscosity of the solution is low, and the nanofiber having relatively large fiber diameter is produced when the viscosity of the solution is relatively high because the temperature is relatively low.

The concentration measuring device for measuring the concentration has a contact type and a non-contact type in direct contact with a solution, and a capillary type concentration measuring device and a disk (DISC) type concentration measuring device can be used as a contact type. A concentration measuring device using the infrared or a concentration measuring device using infrared can be used.

The heating device of the present invention may be an electric heater, a hot water circulating device, a hot air circulating device, or the like. In addition, devices capable of raising the temperature in the same range as the above devices may be borrowed.

As an example of the heating device, the electro-thermal heater may be used in the form of a hot wire, and coil-shaped hot wires 62a and 62b may be mounted inside the tube 43 of the nozzle block 110, (See Figs. 7 to 13).

It is also possible to have the configuration of the linear heat lines 62a and 62b and the U-shaped pipe 63.

As shown in FIG. 7, such a heating apparatus includes a nozzle block 110 in which a polymer solution is radiated, a tank (main storage tank, intermediate tank or regeneration tank) and an overflow system 200 And a transfer pipe that is transferred from the recovery unit to the regeneration tank).

The cooling device of the present invention may be a cooling device including a chilling device, and the means for maintaining a constant viscosity of the polymer solution is usually applicable. The cooling device may be provided in at least one of the nozzle block 110, the tank, and the overflow system 200 in the same manner as the heating device, and is used to maintain a certain viscosity of the polymer solution.

In addition, the temperature control device 60 of the present invention includes a sensor for measuring the concentration and a temperature control unit (not shown) for controlling the temperature accordingly.

The sensor is installed in the main storage tank 210, the intermediate tank 220, the regeneration tank 230, the nozzle block 110 or the overflow system 200 to measure the concentration of the flushing liquid in real time, The heating device and / or the cooling device is operated so that the viscosity is kept constant in the device 60. [

The concentration of the polymer solution re-supplied through the overflow system 200 of the present invention is 20 to 40%, which is a high concentration solution compared to the concentration of the polymer solution used in conventional electrospinning of 10 to 18%.

In addition, the temperature of the polymer solution according to the concentration of the polymer solution is adjusted to 45 to 120 캜, rather than the room temperature, in order to maintain the viscosity of the polymer solution to be supplied again.

Meanwhile, the viscosity of the polymer solution of the present invention is preferably 1,000 to 5,000 cps, more preferably 1,000 to 3,000 cps. If the viscosity is 1,000 cps or less, the quality of the nanofibers to be electrospun is poor, and if the viscosity is 3,000 cps or more, the polymer solution can not be easily discharged from the nozzle 42 during the electrospinning, resulting in a slow production rate.

In addition, the present invention is characterized in that as the electrospinning progresses, the viscosity of the polymer solution is constant and the ease of spinning during electrospinning is excellent, and the concentration of the polymer solution is increased. As a result, the amount of solids in the nanofiber, There is an increasing effect.

In addition, the amount of the residual solvent of the nanofibers using electrospinning is lower than that of the conventional electrospinning, and thus it is possible to produce nanofibers of excellent quality.

The temperature control device 60 of the present invention measures the viscosity of the polymer solution through the temperature control of the nozzle block 110 or the main storage tank 210 by measuring the concentration of the intermediate tank 220 in an off- Which can be controlled manually, and which can automatically control the temperature of the solution according to the concentration measurement through an automatic control system on-line.

Hereinafter, the polymer of the spinning solution used in the present invention will be described.

The type of the polymer spinning solution is not particularly limited, and examples thereof include polypropylene (PP), polyethylene terephthalate (PET), polyvinylidene fluoride, nylon, polyvinylacetate, polymethylmethacrylate, (PAN), polyurethane (PUR), polybutylene terephthalate (PBT), polyvinyl butyral, polyvinyl chloride, polyethyleneimine, polyolefin, polylactic acid (PLA), polyvinyl acetate (PEN), polyamide (PA), polyvinyl alcohol (PVA), polyethyleneimide (PEI), polycaprolactone (PCL), polylactic acid glyceric acid (PLGA), silk, cellulose, chitosan and the like (PP) materials and heat resistant polymer materials such as polyamide, polyimide, polyamideimide, poly (meta-phenylene isophthalamide), polysulfone, polyether ketone, polyetherimide, Aromatic polyesters such as polyethylene terephthalate, polytrimethylene terephthalate and polyethylene naphthalate, polytetrafluoroethylene, polydiphenoxaphospazene, and polybis [2- (2-methoxyethoxy) phosphazene] Polyurethane copolymers including polyphosphazenes, polyurethanes and polyether urethanes, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are preferably used in a commercial manner. More preferably, the polymer spinning solution may include one selected from the group consisting of polyurethane, polyvinylidene fluoride and polyamide.

On the other hand, the spinning solution is prepared by dissolving the polymer in a solvent, and the type of the solvent is not limited as long as it can dissolve the polymer, and examples thereof include phenol, formic acid, sulfuric acid, m-cresol, Methyl isobutyl ketone, methyl ethyl ketone, aliphatic hydroxyl group, m-butyl alcohol, isobutyl alcohol, isobutyl alcohol, isobutyl alcohol, isopropyl alcohol, Hexane, tetrachlorethylene, acetone, propylene glycol, diethylene glycol, ethylene glycol as a glycol group, trichlorethylene as a group of halogen compounds, dichloromethane, aromatic compounds such as methylene chloride, Toluene, xylene, aliphatic cyclic compound groups such as cyclohexanone, cyclohexane and ester groups such as n-butyl acetate, ethyl acetate, Group ether group in salbeu, ethyl 2-butyl-cell-ethoxyethanol, may be used. Ethoxyethanol, dimethylformamide to, dimethylacetamide or the like 2 can be used a mixture of a plurality kinds of solvents. The spinning solution preferably contains an additive such as a conductivity improver.

The polyurethane, which is one of the polymers used in the present invention, can be produced by using a known polyurethane reaction technique. For example, it is possible to prepare an intermediate polymer having an isocyanate group at its terminal by reacting a polyalkylene ether glycol with an excess molar of an organic diisocyanate in an amide polar solvent, then dissolving the intermediate polymer in an amide polar solvent, The polyurethane polymer can be obtained by reacting an end terminator.

In the production of the hydrophilic polyurethane prepolymer, polyether polyols are preferably synthesized in a molar ratio of 0.15 to 0.95 based on 1 to 3 moles of isocyanate.

Examples of the isocyanate include isophorone diisocyanate, 2,4-toluene diisocyanate and its isomers, diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, bis (2-isocyanate ether) , 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 1,6-hexane diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethylphenylene diisocyanate, 1,3-xylene diisocyanate, and the like. Of these, diphenylmethane diisocyanate, 2,4-xylene diisocyanate, 1,4-xylene diisocyanate, - toluene diisocyanate and its isomers, p-phenylenediisocyanate, isophorone diisocyanate, hexamethylene diisocyanate It is better to use it.

The polytetrahypolyol includes an ethylene oxide / propylene oxide random copolymer having three or more hydroxyl groups in the molecule and having a molecular weight of 3,000 to 6,000 and an ethylene oxide content of 50 to 80%, a polyoxyethylene / propylene oxide random copolymer having two or more hydroxyl groups in the molecule, Propylene oxide random copolymer having 3 hydroxyl groups in the molecule and a molecular weight of 3,000 to 6,000 and an ethylene oxide content of 50 to 80% by weight, based on the weight of polypropylene glycol having a molecular weight of 3,000 to 4,000, Should be used alone. However, in order to control the physical properties, a mixture of a polyisocyanate compound and a polyisocyanate compound not mentioned above may be used.

On the other hand, the hydrophobic polyurethane used in the present invention has a structure in which a firing group is branched, which is obtained by reacting a polyalkylene oxide with a polyfunctional substance, a diisocyanate and water, and reacting the obtained product with a hydrophobic monofunctional active hydrogen- Lt; RTI ID = 0.0 > isocyanate. ≪ / RTI > The hydrophobic group may be independently selected from the group consisting of alkyl, aryl, arylalkyl, alkenyl, arylalkenyl, cycloaliphatic, perfluoroalkyl, carbocylic, polysycyl and composite resin, The aryl, arylalkyl, arylalkenyl, alicyclic, and polycyclyl hydrophobic groups include from 3 to 40 carbon atoms. The term " alkyl "

On the other hand, polyvinylidene fluoride (PVDF) (hereinafter referred to as PVDF) used in the present invention is one of fluorine-based polymers, and the fluororesin contains fluorine, which is excellent in thermal and chemical properties.

[Reaction Scheme 1]

PVDF is prepared by the same process as in the above reaction formula 1, and has a melting point (177) and a density (1.78) lower than those of other fluororesin, and is cheap in chemical cost and low in unit cost. It is also used as an advanced paint for exterior walls.

In addition, PVDF is a representative organic material exhibiting piezoelectricity, and many studies have been conducted since the 1960s. In PVDF polymer, four kinds of crystals are mixed, and it can be divided into at least four types of α, β, γ and δ type depending on crystal form. Among them, β-type crystals of PVDF are filled with trans-type molecular chains in parallel, and all of the permanent dipoles of the monomers are aligned in one direction and exhibit large spontaneous polarization. This means that PVDF molecules are arranged regularly through stretching to impart piezoelectricity by giving anisotropy to the aggregated state. In order to improve such piezoelectric properties, various methods for increasing the? -Form crystal in the PVDF fiber have been studied.

The polyamide as one of the polymers used in the present invention means a general term of a polymer linked by an amide bond (-CONH-) and can be obtained by condensation polymerization of a diamine and a dicarboxylic acid. Polyamides are characterized by amide bonds in the molecular structure, and their physical properties vary depending on the ratio of amide groups. For example, when the ratio of amide groups in the molecule is increased, specific gravity, melting point, absorbency, rigidity and the like are increased.

In addition, polyamide is a material used in a wide range of fields such as clothing, tire cord, carpet, rope, computer ribbon, parachute, plastic and adhesive due to its excellent resistance to corrosion, abrasion resistance, chemical resistance and insulation.

Generally, polyamides are classified into aromatic polyamides and aliphatic polyamides. Representative aliphatic polyamides include nylon. Nylon is originally a trademark of DuPont, Inc., but is now used as a generic name.

Nylon is a hygroscopic polymer and is sensitive to temperature. Representative nylons include nylon 6, nylon 66, and nylon 46.

First, nylon 6 is characterized by excellent heat resistance, moldability and chemical resistance, and is produced by ring-opening polymerization of ε-caprolactam in order to produce it. Nylon 6 means that caprolactam has 6 carbon atoms.

[Reaction Scheme 2]

On the other hand, nylon 66 is generally similar in properties to nylon 6, but is superior in heat resistance to nylon 6 and superior in self-extinguishing and abrasion resistance. Nylon 66 is prepared by dehydration condensation polymerization of hexamethylenediamine and adipic acid.

[Reaction Scheme 3]

Nylon 46 is also excellent in heat resistance, mechanical properties and impact resistance, and has a high processing temperature. Nylon 46 is prepared by polycondensation of tetramethylenediamine and adipic acid. Diaminobutane (DAB), a raw material, is prepared from the reaction of acrylonitrile with hydrogen cyanide. In the first stage of the polymerization operation, a salt is formed from diaminobutane and adipic acid, and the mixture is polymerized under appropriate pressure The prepolymer is converted into a prepolymer and the solid of the prepolymer is polymerized at a solid state by treatment at about 250 ° C in the presence of nitrogen and water vapor.

Nylon 46, in particular, is characterized by a high amide concentration and a regular arrangement between the methylene and amide groups. The melting point of nylon 46 is about 295 ° C, which is higher than that of other types of nylon, and has attracted attention as a resin having excellent heat resistance due to the above characteristics.

On the other hand, the inorganic polymer of the spinning solution used in the present invention will be described.

The inorganic polymer refers to a polymer containing an inorganic element in a polymer main chain or a side chain. Herein, the inorganic element is narrowly defined as an internal transition such as a metal such as aluminum and magnesium which fill s and p orbitals, a transition metal such as titanium, zirconium and tungsten filling the d orbit, and a lanthanide-actinide group which fets the f orbit Metal), but broadly includes elements constituting the skeleton of elements such as Si, Ge, P, and B which are non-metallic inorganic elements.

The inorganic polymers are divided into the following four types.

First, when the inorganic component is contained in the side chain of the organic polymer, the organic polymer is maintained substantially in the nature and the inorganic component contained in the side chain is also represented. Second, the inorganic element is bonded to the skeleton of the polymer main chain with carbon Thirdly, in the case of an organic-inorganic hybrid polymer designed to serve as a precursor for the production of ceramics, fourthly, in the case of an ionic compound having a net-like structure or a lattice structure composed purely of inorganic components.

Interest in inorganic polymers began to emerge from the commercialization of silicon carbide (SiC) fibers (trade name: NICALON) synthesized by Polycarbosilane (PCS) by Yajima of Nippon Carbon in the mid 1980's It became an occasion. Until now, it is not so much utilized, but it is expected to be applied in the field of heat resistance in general industries as well as aerospace and nuclear fields in the future. Polymer impregnation and pyrolysis (PIP) is a method of applying an inorganic polymer to a composite. This is a method in which an organic compound such as PCS is mixed with a silicon carbide powder to prepare a slurry, Is impregnated into a fiber preform and pyrolyzed to obtain a silicon carbide base. Recently, attention has been paid to the development of a fiber having excellent heat resistance. Thus, by developing a new organic compound having excellent characteristics and improving the PIP method, a pyrolysis temperature can be increased to produce a silicon carbide base matrix having excellent crystallinity and stoichiometric ratio.

A method of preparing an inorganic polymer nanofiber by electrospinning the inorganic polymer of the present invention will be described.

First, a spinning solution is prepared by dissolving the inorganic polymer in an acetone solvent. The spinning solution containing the inorganic polymer is stored in the spinning liquid main tank, metered by a separate metering pump, and supplied to the spinning solution dropping device by a predetermined amount.

When the nanocomposite is made of an inorganic polymer or used in the production of an active layer of a composite membrane, the number average molecular weight of the inorganic polymer is 5,000 to 100,000. When nanofibers are produced by mixing or adding to other polymers or inorganic materials, Is used in the range of 10,000 to 100,000.

The inorganic polymer may be a siloxane group or a siloxane group alone, or may be a copolymer of a silane group or a siloxane group with a polymer of monomethacrylate, vinyl, hydride, distearate, bis (12-hydroxy-stearate) (Aminopropyl-aminopropyl) aminopropyl, mono- and di (aminopropyl) mono-, di-, tri-, and tetra- ) Dimethoxysilyl) ether may be used.

The method for producing the nanofiber web according to the present invention will be described in detail.

Hereinafter, a method of manufacturing a filter according to an embodiment of the present invention will be described, but the present invention is not limited thereto.

First, the polymer spinning solution in which the polymer is dissolved in an organic solvent is supplied to the spinning liquid main tank of the electrospinning device 10, and the polymer spinning solution supplied to the spinning solution main tank is supplied to the nozzle block (2) of the nozzle (3).

The polymer spinning solution supplied to each of the nozzles 2 is injected onto the substrate 5 while being radiated and focused on the collector 4 with a high voltage applied thereto through the nozzle 2 to form the polymer nanofibers. In the apparatus in which the polymer nanofibers are laminated in the front end block 20a of the electrospinning device 10, a feed roller 11 operated by driving of a motor (not shown) Is transferred from the front end block 20a into the rear end block 20b by the rotation of the auxiliary belt 6 driven by the driving force.

At this time, when a stagger device (not shown) for reversing the substrate from the front end block 20a to the rear end block 20b is provided and is transferred from the front end block 20a to the rear end block 20b, The position of the negative is changed.

The base material in which the positions of the upper surface portion and the lower surface portion are reversed is that in the back end block 20b, the spinning solution supplied to the main tank in which the inorganic polymer solution for the inorganic polymer dissolved in the organic solvent is injected, Is supplied continuously and quantitatively into the plurality of nozzles 2 of the block 3.

At this time, the front end block 20a is referred to as a first feeding device and the rear end block 20b is referred to as a second feeding device.

More specifically, the first and second main tanks for storing the electrospinning liquid of the present invention respectively store the polymer spinning liquid and the inorganic polymer spinning liquid, and the first and second feeding apparatuses are integrally formed of a closed cylindrical And serves to supply the spinning solution continuously injected from the spinning liquid tank for each section. The nozzle block is divided into two sections, and first and second supply devices are provided in each section to supply the polymer spinning solution, respectively.

In the filter on both sides of the fabricated substrate, the polymer nanofiber surface is arranged in the air inlet direction and the inorganic polymer nanofiber is arranged in the air outlet direction in the air filter process. Since gas turbine air filter introduces high temperature air in the air inlet direction when using the air filter, it can extend the life of the filter because the heat resistant polymer is used.

At this time, the basis weight of the nanofibers is preferably 0.1 to 10 g / m 2, more preferably 0.1 to 2 g / m 2. If the basis weight is less than 0.1 g / m < 2 >, the physical properties of the filter are deteriorated. If the basis weight exceeds 10 g / m &

Meanwhile, the length of the section defined by the nozzle block can be adjusted according to the thickness of each layer constituting the filter.

Further, the collector of the grounded collector can be controlled to be moved in one direction, and a continuous process of forming a continuous nanofiber layer can be performed. The present invention simplifies the manufacturing process of the double-sided filter through such a process and increases the production speed have.

The thickness of the polymer film, the diameter of the fiber, and the mechanical characteristics of the shape of the fiber can be arbitrarily controlled by controlling the electrospinning process conditions such as the intensity of the applied voltage, the kind of the polymer solution, the viscosity of the polymer solution, have.

The preferred electrospinning process conditions are such that when the spinning solution transferred to the spinning liquid supply tube is discharged to the collector through the multi tubular nozzle to form the fibers, the nanofibers electrospun from the multi-tubular nozzles are ejected from the air- When it spreads widely and is collected on the collector, the collecting area becomes wider and the density of the collecting becomes uniform. The excess flushing liquid which is not fibrous in the tubular nozzle is collected in the overflow removing nozzle and then moved to the flushing liquid supply plate through the temporary storage plate of the overflow liquid.

When manufacturing nanofibers, it is preferable that the speed of air in the air supply nozzle is 0.05 m to 50 m / sec, more preferably 1 to 30 m / sec. If the velocity of the air is less than 0.05 m / sec, the collecting area of nanofibers is not so low and the collecting area is not greatly improved. If the velocity of the air exceeds 50 m / sec, The more serious problem is attached to the collector in the form of a thick thread rather than the nanofiber, thereby causing a serious problem that the capability of forming the nanofiber is remarkably lowered.

In addition, the spinning solution which is excessively supplied to the top of the nozzle block is forcibly transferred to the spinning liquid main tank by the spinning solution discharging device.

In order to promote the formation of fibers by the electric force, a voltage of 1 kV or more, more preferably 20 kV or more, generated in the voltage generator is applied to the conductive plate and the collector provided at the lower end of the nozzle block. It is more advantageous in terms of productivity to use an endless belt as the collector. The collector preferably reciprocates a predetermined distance in the left and right directions to uniform the density of the nanofibers.

When the nanofibers formed on the collector are wound on the winding roller through the web supporting roller, the manufacturing process of the nanofibers is completed.

The manufacturing apparatus can increase the collecting area to uniform the density of the nanofibers and effectively prevent the droplet phenomenon, thereby improving the quality of the nanofibers and enhancing the fiber-forming effect by the electric force, Can be mass produced. In addition, the width and thickness of the nanofibers and filaments can be freely changed and adjusted by arranging the nozzles composed of a plurality of pins in block form.

In addition, when the polymer is spun as described above, it is most preferable to spin the polymer under environmental conditions of 30 to 40 DEG C and 40 to 70% of the temperature depending on the polymer material.

In the present invention, the diameter of the nanofiber forming the multi-layer filter media is preferably 30 to 2000 nm, more preferably 50 to 1500 nm.

In addition, it is possible to make the radial voltages of the front end block and the rear end block of the electrospinning device 10 different from each other, and thus the fiber diameter of the nanofibers can be varied. Namely, the nanofibers having a large fiber diameter and nanofibers having a small fiber diameter are successively formed on the substrate 100 by applying the radiation voltage of the front end block to the lower end and the radiation voltage of the rear end block higher, Can be stacked. For example, the voltage of the front end block may be lowered to form nanofibers having a larger fiber diameter at the front end, and the nanofibers having a smaller fiber thickness may be formed at a higher voltage at the rear end block.

In order to radiate a difference in fiber thickness of the nanofibers 200, a method of imparting a different voltage intensity to each block 20 of the electrospinning apparatus 10 is used. However, A method of adjusting the distance between the nozzles 2 and the collector 4, or a method of controlling the conveying speed of the long sheet may be used.

On the other hand, the nanofibers produced according to the present invention may be laminated by electrospinning in different widths in the width direction, i.e., in the CD direction or in the transverse direction, or different in basis weight in the longitudinal direction, i.e., the MD direction. In this case, the CD direction is the cross direction, which means the direction perpendicular to the MD direction (Machine Direction), the MD direction is referred to as the longitudinal direction / longitudinal direction, and the CD direction is referred to as the width direction / transverse direction. Basis Weight or Grammage is also defined as mass per unit area, i.e., grams per square meter (g / m 2) as a preferred unit.

Fig. 14 is a plan view showing a state in which the nozzles in the spinning solution unit of the present invention are turned on and off in the CD direction, Fig. 15 is a graph showing the relationship between the weights of the polymers in the CD direction, As described above, the operation of the nozzles in the spinning solution unit can be electrically turned on and off to form nanofibers having different basis weights in the CD direction. 16 is a plan view showing a state in which the nozzles in the spinning solution unit of the present invention are turned on and off in the MD direction. As described above, the operation of the nozzles in the spinning solution unit is electrically turned on and off, Nanofibers can be formed.

Further, the filter according to the present invention can be manufactured by using the electrospinning device 1 configured with the bottom-up electrospinning device 10 and the top-down electrospinning device 30 as shown in Fig.

At this time, it is preferable that the bottom-up electrospinning device and the top-down electrospinning device are arranged at a predetermined interval, and the bottom-up electrospinning device is positioned at the front end and the top-down electrospinning device is positioned at the rear end, .

Preferably, the electrospinning device is constituted by three or more electrospinning devices, the bottom-up electrospinning device and the bottom-up electrospinning device are arranged alternately, and a flip device (collector interposing device) 20 is provided between the electrospinning devices It is also preferable that the above-

When the three or more electrospinning apparatuses are arranged alternately, the bottom-up electrospinning apparatus can be placed alternately with the bottom-up electrospinning apparatus placed in the front end first, but it is also possible to arrange the bottom-down electrospinning apparatus first and then alternately.

In the meantime, a flip device is provided between the bottom-up electrospinning device and the bottom-up electrospinning device in the present invention. The flip device (collector stagger device) is positioned between the electrospinning devices, And the lower surface serves to rotate the upper surface to the upper surface.

In the electrospinning device according to the present invention, the polymer spinning solution filled in the spinning liquid main tank of the bottom-up electrospinning device is injected onto the support on the collector through the nozzle, After the sprayed first polymer spinning solution is accumulated, the first nanofibers are formed, and the lower surface of the support on which the first nanofibers are stacked by the flip device is rotated 180 degrees to the upper surface of the support having the nanofibers laminated thereon.

Thereafter, a second polymer spinning solution, which is transported onto the collector of the top-down electrospinning device and filled in the spinning solution main tank of the top-down electrospinning device, is placed on a support on which the first nanofibers transferred onto the collector of the top- And the second nanofibers are stacked on the first nanofibers by being electrospun through the nozzles.

Thereafter, a post-process is performed by a laminating apparatus 40 for laminating a nanofiber web and a support (substrate) manufactured through the bottom-up and top-down electrospinning apparatuses.

In the present invention, the flip device is provided between the bottom-up and top-down electrospinning devices so that the arrangement of the electrospinning devices is arranged in parallel to the horizontal direction, or each of the electrospinning devices is arranged in the vertical direction It is possible to arrange each electrospinning device in the U direction by using a bottom-up electrospinning device. By using a bottom-up electrospinning device, productivity is improved by using a downward electrospinning device. By using a flip device, There is an advantage that lamination of a nanofiber web can be achieved.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

[Example 1]

In the first section, 13% by weight of polyurethane (Pellethane 2363-80AE from DOW, USA) was dissolved in 87% by weight of NN-dimethylacetamide (DMAc) solvent to prepare a polymer spinning solution having a concentration of 13% , And a polysiloxane (DOW CORNING MB50-010) having a number average molecular weight of 50,000, which is one of the inorganic polymers, was dissolved in acetone solvent to prepare a 20 mass% polysiloxane spinning solution.

Polyurethane nanofibers having a basis weight of 0.5 g / m < 2 > were formed on a thermoplastic polyurethane substrate under the conditions of a distance of 40 cm between the electrodes and the collector, an applied voltage of 15 kV, a spinning liquid flow rate of 0.1 mL / h, a temperature of 22 DEG C and a humidity of 20% The collector was moved at a constant speed, and a polysiloxane nanofiber was spun on the back side of the substrate where the polyurethane nanofibers were not laminated in the two sections to have a basis weight of 0.5 g / m < 2 >

[Example 2]

In the first section, polyvinylidene fluoride having a weight average molecular weight (Mw) of 50,000 was dissolved in dimethylacetamide (N, N-dimethylacetamide, DMAc) to prepare a spinning solution having a concentration of 15 wt% Polysiloxane (DOW CORNING MB50-010) having a number average molecular weight of 50,000, which is one of the inorganic polymers, was dissolved in an acetone solvent to prepare a 20 mass% polysiloxane spinning solution.

The polyvinylidene fluoride nanofiber having a basis weight of 0.5 g / m < 2 > was applied to the surface of the thermoplastic polyurethane foil under an electrospinning condition of a distance between the electrode and the collector of 40 cm, an applied voltage of 15 kV, a spinning liquid flow rate of 0.1 mL / h, The collector was moved at a constant speed, and the polysiloxane spinning solution was electrospun so as to have a basis weight of 0.5 g / m < 2 > on the back surface of the substrate where the polyvinylidene fluoride nanofibers were not laminated in the two sections to laminate the polysiloxane nanofibers A filter in which nanofibers were laminated on both sides of the substrate was prepared.

[Example 3]

In the first section, nylon 6 was dissolved in formic acid to prepare a spinning solution having a concentration of 15% by weight. In the second section, a polysiloxane (DOW CORNING MB50-010) having a number average molecular weight of 50,000 as one of the inorganic polymers was dissolved in an acetone solvent To prepare a 20 mass% polysiloxane spinning solution.

Nylon 6 nanofiber having a basis weight of 0.5 g / m < 2 > was formed on a thermoplastic polyurethane substrate under the conditions of a distance of 40 cm between the electrode and the collector, an applied voltage of 15 kV, a flushing liquid flow rate of 0.1 mL / h, a temperature of 22 DEG C and a humidity of 20% The collector was moved at a constant speed to electrospun polysiloxane spinning solution so that the basis weight was 0.5 g / m 2 on the surface of the base material on which the nylon 6 nanofibers were not laminated in the two sections, and the polysiloxane nanofibers were laminated, A laminated filter was prepared.

[Comparative Example 1]

In the first section, a meta-aramid dope is prepared by dissolving meta-aramid having a viscosity of 50,000 cps and a solid content of 20% by weight in dimethylacetamide (DMAc). A 6-μm-thick meta-aramid nanofibers were laminated on the meta-aramid substrate under the conditions of a distance of 40 cm between the electrode and the collector, an applied voltage of 15 kV, a spinning liquid flow rate of 0.1 mL / h, a temperature of 22 ° C. and a humidity of 20% .

- Evaluation of adhesion between substrate and nanofiber

After the filters prepared in Examples 1 and 2 and Comparative Example 1 were washed five times, it was confirmed whether or not the substrate and the nanofibers were desorbed.

- Evaluation of heat shrinkage

The filters of the examples and comparative examples were cut into 3 cm x 3 cm and stored at 190 for 30 minutes, and the heat shrinkage ratio was evaluated and shown in Table 1.

- Filtration efficiency measurement

The DOP test method was used to measure the efficiency of the fabricated nanofiber filter. The DOP test method measures the dioctyl phthalate (DOP) efficiency with an automated filter analyzer (AFT) of TSI 3160 from TSI Incorporated and measures the permeability, filter efficiency and differential pressure of the filter media material .

The automation analyzer is a device that automatically measures the velocity of air, DOP filtration efficiency, air permeability (permeability), etc. by passing DOP through the filter sheet by making particles of desired size and is a very important device for high efficiency filter.

The DOP% efficiency is defined as:

DOP% transmittance = 1 - 100 (DOP concentration downstream / DOP concentration upstream)

The filtration efficiencies of Examples and Comparative Examples were measured by the above-mentioned method and shown in Table 1.

Example 1 Example 2 Example 3 Comparative Example 1 Adhesion evaluation X X X O Heat shrinkage (%) 2.8 2 2 6 0.35 mu m DOP filtration efficiency (%) 94 95 96 60

As can be seen from Table 1, it can be seen that the adhesion, heat shrinkage and filtration efficiency are improved as compared with the case of the embodiment using the thermoplastic polyurethane base.

1, 1a, 1b: voltage generating device, 2, 115, 135: nozzle,
3, 113, 133: nozzle block, 4, 137, 117: collector,
5: thermoplastic polyurethane base, 6: auxiliary belt
7: auxiliary belt roller, 8: case,
9: thickness measuring device, 10: electrospinning device,
11, 120: feed roller, 12, 118: take-up roller,
19: laminating apparatus, 20, 20a, 20b: block
30: main control device, 41: overflow solution storage tank,
43: tube body, 44: spinning liquid storage tank,
45: Fluid distribution pipe,
200: Polymer nanofibers
300: inorganic polymer nanofiber.
100: Combined electrospinning device 121: Support
119: Feed roller
110, 110 ': bottom-up electrospinning device 111, 131: main tank
130, 130 ': Top-down electrospinning device

Claims (11)

Thermoplastic polyurethane base;
Polymer nanofibers having a basis weight of 0.1 to 2 g / m ² laminated by electrospinning a polymeric spinning solution on the thermoplastic polyurethane base; And
Polymer nanofibers having a basis weight of 0.1 to 2 g / m < ² > laminated by electrospinning on a thermoplastic polyurethane base material on the back surface where the polymer nanofibers are not laminated,
Wherein the polymer nanofibers and the inorganic polymer nanofibers have different weights in the transverse direction or in the longitudinal direction, respectively.
The method according to claim 1,
The polymeric spinning solution may be selected from the group consisting of polyethylene terephthalate (PET), polyvinylidene fluoride, polyvinyl acetate, polymethylmethacrylate, polyacrylonitrile (PAN), polyurethane (PUR), polybutylene terephthalate (PBT) (PAI), polyvinyl alcohol (PVA), polyethylene imide (PEI), polycaprolactone (PEI), polyvinyl butyral, polyvinyl butyral, polyvinyl chloride, polyethyleneimine, polyolefin, polylactic acid (PLA), polyethylene naphthalate Wherein the adhesive layer comprises one selected from the group consisting of lactone (PCL), polylactic acid glycolate (PLGA), silk, cellulose and chitosan.
The method according to claim 1,
Wherein the inorganic polymer nanofiber is formed by electrospinning a polymer selected from the group consisting of a silane group or a siloxane group alone polymer and a copolymer polymer of a silane group or a siloxane group. .
delete The method according to claim 1,
Wherein the nanofiber web is for a filter.
delete delete delete delete delete delete

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