WO2019050128A1

WO2019050128A1 - Waterproof ventilation sheet and manufacturing method therefor

Info

Publication number: WO2019050128A1
Application number: PCT/KR2018/005718
Authority: WO
Inventors: 백지숙; 김성진; 김철기; 오흥렬
Original assignee: 코오롱패션머티리얼 (주)
Priority date: 2017-09-06
Filing date: 2018-05-18
Publication date: 2019-03-14
Also published as: CN111065772B; CN111065772A

Abstract

The present invention relates to a waterproof ventilation sheet and a manufacturing method therefor, and the waterproof ventilation sheet comprises a nanomembrane, in which nanofibers are integrated in a non-woven fabric form including a plurality of pores, the waterproof ventilation sheet has a waterproof property against water pressure without leaking for 30 minutes or more under a water pressure of 1.5 m or more at a room temperature (20°C ± 5°C), and a sound transmission loss is less than 10 dB at 1000 Hz. The waterproof ventilation sheet controls a fine structure of a nanomembrane or orientation of a nanofiber so as to suppress absorption and diffused reflection of sound and to lower a sound absorption coefficient, improves waterproof, dustproof, and antifouling performance by forming a water repellent coating layer in the nanomembrane, resolves sound distortion by lowering a sound transmission loss measurement value, improves more a waterproof property by further including water repellent and oil repellent additives, and improves resistance to water pressure by improving the modulus of elasticity and strength of the nanomembrane and having great resistance to pressure strain caused by applied water pressure during resistance to water pressure.

Description

Waterproof breathable sheet and manufacturing method thereof

The present invention relates to a waterproof breathable sheet and a method of manufacturing the same. More particularly, the present invention relates to a waterproof breathable sheet in which acoustic distortion is resolved by suppressing absorption and diffuse reflection of a sound and lowering a sound absorption coefficient, .

In a variety of electronic devices such as mobile devices and hearing aids, communication devices such as radio transmitters, automobile head lamps, etc., permeability is imparted to the electronic devices to maintain pressure balance inside / outside the electronic devices, Waterproof to prevent penetration of water / liquid into the inside, and dustproof to prevent contamination / dust penetration. Accordingly, the electronic devices include a waterproof ventilation sheet having both waterproof / dustproof and air permeability.

Particularly, electronic devices such as mobile devices have various performance and functions, and thus frequency of use has been increased. As a result, not only waterproof / dustproof functions in various environments, but also acoustic performance Are also required.

It is an object of the present invention to provide a method of controlling nanostructures of a nanomembrane, that is, controlling the diameter, thickness, pore size distribution, By forming a water repellent coating layer on the nanomembrane to improve the waterproof, dustproof and anti-fouling performance, and by reducing the measured value of the acoustic transmission loss, the distortion of the sound is eliminated and the waterproofing property is further improved by further including the water- A waterproof breathable sheet having improved resistance to pressure deformation due to water pressure applied during water pressure resistance by improving elasticity and strength and improved water pressure.

It is still another object of the present invention to provide a nanofiltration membrane that is prepared by electrospinning polyvinylidene fluoride, wherein the electrospinning conditions are controlled or the microstructure of the nanomembrane is adjusted by appropriately adjusting the electrospinning conditions and the composition for forming the water- A water permeable ventilation sheet which is excellent in water permeability and water permeability and can enhance stability and usability in a roll-to-roll process can be manufactured by uniaxially orienting the nanofiber prepared by the above-mentioned electrospinning process And to provide a method of manufacturing a waterproof breathable sheet.

According to an embodiment of the present invention, there is provided a nanofiber comprising a nanomembrane in which nanofibers are integrated in the form of a nonwoven fabric including a plurality of pores, wherein the nanofiber has a normal temperature (20 DEG C +/- 5 DEG C) Provides a waterproof breathable sheet that is waterproof and has an acoustic transmission loss of less than 10 dB at 1000 Hz.

The nanofiber may have a diameter of 50 nm to 3000 nm, a thickness of 3 to 40 탆, a pore size of 0.1 to 5 탆, and a porosity of 40 to 90%.

Wherein the nanomembrane has irregular size distribution of the pores so that the nanofibers are irregularly aligned and laminated, and the size distribution of the irregular pores is 100 nm or more in the size difference of the pores per unit area (cm ² ) of the nanomembrane The probability of finding pores can be over 10/100.

The surface of the nanofibers may include a water repellent coating layer.

The nanofibers may include 100 parts by weight of a fluoropolymer and 1 to 50 parts by weight of a water-repellent oil additive.

The nanomembrane may have an anisotropy (MD elastic modulus / TD elastic modulus) in a machine direction (MD) and a transverse direction (TD) of 1.5 to 10.0.

The nanomembrane has a shape (1 character) of 2 to 50 in aspect ratio (SD: LD) of the smallest diameter (SD) of the pore with respect to the longest diameter (LD) of the pore, And the longest diameter (LD) may be oriented in a direction parallel to the longitudinal direction of the nanomembrane.

Wherein the nanomembrane has an absorption coefficient of less than 0.2 at 1000 Hz and an acoustic transmission loss of less than 10 dB at 1000 Hz, the nanomembrane has an air permeability of 0.1 CFM to 20 CFM, a water pressure of 3000 mmH ₂ O or more, A grade of 4 or more, a modulus of elasticity of 1 MPa to 1000 MPa, and a basis weight of 0.5 g / m 2 to 20 g / m 2.

The waterproof ventilation sheet was subjected to high temperature / high humidity conditions (50 DEG C, 95% humidity, 72 hours, no water leaks for at least 30 minutes at a water pressure of 1.5 m or more in the case of waterproof waterproof property at low temperature (Measured after repeating 30 cycles of one cycle maintaining -40 ° C and 85 ° C for 1 hour respectively) without leaking at a water pressure of 1.5 m or more for 30 minutes or more and 1.5 m or more And the waterproof ventilation sheet may have a breathability of 20 cc / min (@ 1 PSI) or more.

The nanofibers may be made of polyvinylidene difluoride (PVdF).

According to another embodiment of the present invention, there is provided a method of manufacturing a nanostructure, comprising the steps of: preparing an electrospinning solution; and electrospinning the prepared electrospinning solution to produce a nanomembrane in which nanofibers are integrated into a nonwoven fabric including a plurality of pores The present invention also provides a method of manufacturing a waterproof ventilation sheet. According to the method for producing a waterproof breathable sheet, a waterproof breathable sheet having a waterproofing and waterproofing property that does not leak at a normal temperature (20 ° C ± 5 ° C) and a water pressure of 1.5 m or more for 30 minutes or more and an acoustic transmission loss of less than 10 dB at 1000 Hz .

Wherein the concentration of the electrospinning solution is 5% to 35%, the viscosity is 100 cP to 10000 cP, the electrospinning condition is a voltage of 0 kV to 100 kV and a discharge amount of 0.01 cc / min to 100 cc / min have.

The method of manufacturing the waterproof breathable sheet may further include forming a water repellent coating layer on the surface of the nanofibers.

The electrospinning solution may include 100 parts by weight of a fluoropolymer, 1 to 50 parts by weight of a water-repellent oil additive, and 250 to 2000 parts by weight of a solvent.

The method for manufacturing the waterproof breathable sheet may further include uniaxially orienting the nanomembrane.

The uniaxial orientation of the nanomembrane may be performed by applying a tensile force of 1.5 to 20 times the longitudinal direction of the nanomembrane as compared to the width direction of the nanomembrane.

The uniaxial orientation of the nanomembrane may be controlled by controlling the winding speed of the nanomembrane to 0.01 m / min to 20 m / min and the TR (traverse) rate to 0.001 m / min to 10 m / min .

The waterproof breathable sheet according to the present invention is able to control the microstructure of the nanomembrane, that is, the diameter, thickness and pore size distribution of the nanofiber, thereby suppressing sound absorption and diffuse reflection, and lowering the sound absorption coefficient.

Further, the waterproof breathable sheet of the present invention can improve the waterproof, dustproof and anti-fouling performance by forming a water repellent coating layer on the nanomembrane, and control the microstructure of the nanomembrane, that is, the diameter, thickness, By suppressing absorption and diffuse reflection and lowering the acoustic transmission loss measurement, distortion of the sound is resolved.

Further, the waterproof breathable sheet of the present invention controls the microstructure of the nanomembrane to suppress sound absorption and diffuse reflection and lower the measured value of acoustic transmission loss, thereby eliminating sound distortion, improving the elastic modulus and strength of the nanomembrane Resistance to pressure deformation due to water pressure applied during water pressure is increased to improve water pressure, and water repellency and oil repellency are further improved by further including a water-repellent oil additive.

The waterproof breathable sheet of the present invention controls the microstructure of the nanofiber of the nanomembrane, in particular, the orientation of the nanofiber, thereby suppressing sound absorption and diffusing reflection, lowering the absorption coefficient to eliminate sound distortion, The elastic modulus and strength are improved, resistance to pressure deformation due to water pressure applied during water pressure increase, and water pressure is improved.

The method for producing a waterproof breathable sheet according to the present invention is manufactured by electrospinning polyvinylidene fluoride. In this case, by controlling the electrospinning conditions to control the microstructure of the nanomembrane, A waterproof ventilation sheet excellent in water resistance and air permeability can be produced.

The method for producing a waterproof breathable sheet of the present invention is a method for preparing a breathable air-permeable sheet, which comprises preparing a composition for forming a water-repellent coating layer by electrospinning polyvinylidene fluoride, By controlling the microstructure of the nanomembrane, it is possible to produce a waterproof breathable sheet having excellent water permeability and excellent waterproofing and waterproofing properties.

In addition, the method for producing a waterproof breathable sheet of the present invention is manufactured by electrospinning polyvinylidene fluoride. In this case, the electrospun nanomembrane is uniaxially oriented to have excellent voicing and waterproofness and water permeability It is possible to manufacture an excellent waterproof ventilation sheet and to enhance stability and usability in a roll-to-roll process.

Fig. 1 is a perspective view schematically showing one embodiment of the waterproof breathable sheet of the present invention. Fig.

2 is a perspective view schematically showing another embodiment of the waterproof breathable sheet of the present invention.

3 is a perspective view schematically showing a jig used in a water pressure measuring instrument for measuring hydraulic waterproofness.

4 is a schematic view of a nozzle-type electrospinning device.

5 and 6 are scanning electron microscope (SEM) photographs of the nanomembranes prepared in Example 4-1 and Comparative Example 4-1 of the present invention, respectively.

Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art.

The waterproof breathable sheet according to an embodiment of the present invention includes a nanofiber in which nanofibers are integrated into a nonwoven fabric including a plurality of pores. The waterproof breathable sheet has a normal temperature (20 DEG C +/- 5 DEG C) , And the acoustic transmission loss is less than 10 dB at 1000 Hz.

Fig. 1 is a perspective view schematically showing one embodiment of the waterproof breathable sheet of the present invention. Fig. Hereinafter, the waterproof breathable sheet will be described with reference to FIG.

1, the waterproof ventilation sheet 100 includes a nanomembrane 10 in which nanofibers are integrated in the form of a nonwoven fabric including a plurality of pores, and, optionally, one or both surfaces of the nanomembrane 10 And may further include an adhesive layer 20. 1, the waterproof ventilation sheet 100 may further include a support (not shown) for supporting the nanomembrane 10.

1, the waterproof ventilation sheet 100 is shown as being circular. However, the present invention is not limited thereto, and the waterproof ventilation sheet 100 may have a circular shape, an elliptical shape, a rectangular shape, P-shaped, or the like.

1, the adhesive layer 20 is located only on one surface of the nanomembrane 10, but the present invention is not limited thereto. The adhesive layer 20 may be formed on the surface of the nanomembrane 10, As shown in FIG.

The nanomembrane 10 has a porous structure formed by the nanofibers to prevent foreign matter such as water or dust from passing therethrough and permeate the gas. In addition, the nanomembrane 10 allows passage of sound. Therefore, the waterproof ventilation sheet 100 is, for example, an electronic device having a sounding portion or a sound receiving portion, which is disposed in the ventilation hole of the housing corresponding to the sounding portion or the sound receiving portion, And can be used for ensuring dustproofness.

For this purpose, the nanomembrane 10 may be made of a polymer having excellent hydrophobicity, chemical resistance, heat resistance, and processing characteristics, and specifically includes, for example, a polyolefin such as polyamide, polyester, polyethylene or polypropylene, polyvinylidene fluoride Such as polyvinylidene difluoride (PVdF), tetrafluoroethylene hexafluoropropylene copolymer (FEP), tetrafluoroethylene (perfluoroacryl) vinyl ether copolymer (PFA) or polytetrafluoroethylene (PTFE) A polyimide polymer such as polyimide (PI), polyetherimide (PEI) and polyamideimide (PAI), polyether sulfone (PES), polyacrylonitrile (PAN) and the like.

Conventionally, the waterproof breathable sheet 100 is mainly made of a porous PTFE sheet. Specifically, the porous PTFE sheet can be produced by forming a kneaded product of a PTFE fine powder and a molding auxiliary agent into a sheet by extrusion molding and rolling, removing the forming auxiliary agent to obtain a sheet body of the formed body, and then stretching the sheet body have. However, since the porous PTFE sheet is liable to shrink due to the passage of time and heat, the waterproof breathable sheet 100 shrinks and the adhesive layer 20 is exposed.

Accordingly, it is preferable that the nanomembrane 10 is a nanoweb fabricated by electrospinning the PVdF. Since the PVdF is excellent in hydrophobicity, chemical resistance, and heat resistance, the nanomembrane 10 manufactured by electrospinning it can have excellent waterproofing and waterproofing properties and air permeability.

However, the nano-web produced by electrospinning the PVdF may have a poor sound absorption due to the regularly oriented / laminated nanofibers constituting the nanofibers, because the pores in the fiber are circular or polygonal, and the absorption coefficient is high. Accordingly, in the present invention, the PVDF is electrospun to control the electrospinning conditions during the manufacture of nanofibers to adjust the air permeability of the nanomembrane 10 and the size distribution of the pores, thereby suppressing sound absorption and diffuse reflection, The coefficient is lowered so as to have a superior voice.

The waterproof breathable sheet according to an embodiment of the present invention includes a nanomembrane in which nanofibers are integrated into a nonwoven fabric including a plurality of pores, wherein the nanofiber has a diameter of 50 nm to 3000 nm and a thickness Of 3 mu m to 40 mu m, a pore size of 0.1 mu m to 5 mu m, and a porosity of 40% to 90%. The waterproof ventilation sheet has a waterproofing waterproofing property that does not leak at normal temperature (20 ° C ± 5 ° C), a water pressure of 1.5 m or more for 30 minutes or more, and an acoustic transmission loss of less than 10 dB at 1000 Hz.

The nanomembrane 10 may have a diameter of 50 nm to 3000 nm, specifically 100 nm to 2000 nm, and the thickness of the nanomembrane 10 may be 3 to 40 μm, And the pore size of the nanomembrane 10 may be 0.1 to 5 占 퐉, specifically 0.1 to 4 占 퐉, the porosity may be 40 to 90%, specifically 60% To 90%, and the basis weight of the nanomembrane 10 may be 0.5 g / m 2 to 20 g / m 2, specifically 1 g / m 2 to 15 g / m 2.

The pore size and pore distribution of the nanomembrane 10 were measured using a capillary flow porometer (CFP) as specified in ASTM F316 to determine the average pore size and the pore size at the diameter of the limiting pore in the narrowest interval The size distribution of the pores can be measured. The thickness of the nanomembrane 10 can be measured by the thickness measurement method defined in KS K 0506 or by applying KS K ISO 9073-2 and ISO 4593. [ The basis weight of the nanomembrane 10 can be measured by applying KS K 0514 or ASTM D 3776. The porosity of the nanomembrane 10 may be calculated according to the ratio of the volume of air to the total volume of the nanomembrane 10 according to Equation (1). The total volume can be obtained by measuring the width, length, and thickness of a rectangular or circular sample, and the air volume can be obtained by subtracting the volume of the polymer inversely calculated from the density after measuring the mass of the sample from the total volume.

[Equation 1]

The porosity (%) = [1 - (A / B)] 100 = {1 - [(C / D) / B]

(Where A is the density of the nanomembrane, B is the density of the nanomembrane polymer, C is the weight of the nanomembrane, and D is the volume of the nanomembrane)

As described above, when the diameter of the nanofiber composing the nanomembrane 10 and the thickness, pore size, and pore distribution of the nanomembrane 10 are within the above ranges, the absorption of the nanomembrane 10 and the diffuse reflection The distortion of the sound can be solved by lowering the sound absorption coefficient.

More specifically, the nanomembrane 10 is advantageous in that the nanofibers are irregularly oriented and laminated so that the size distribution of the pores is irregular, thereby suppressing the negative absorption and the diffuse reflection, thereby lowering the absorption coefficient. Specifically, When the size distribution of the nanomembrane 10 is 100/100 or more, the size distribution of the pores is larger than that of the nanomembrane 10 (cm < ² >). The size distribution of the pores is more irregularly arranged when the probability of finding pores having a pore size difference of 100 nm to 3900 nm per unit area (cm ² ) of 10/100 to 90/100 is more irregularly arranged, Absorption and diffuse reflection can be suppressed as much as possible.

Here, the unit area of the nanomembrane 10 measuring the size distribution of the pores may be any surface of the nanomembrane 10, specifically, both surfaces of the membrane, or an internal cross-section that is exposed by cutting the membrane , Preferably a unit area randomly selected from both surfaces of the membrane. The difference in size of the pores is a value obtained by subtracting the size of the smaller pores from the size of the larger pores among the two pores arbitrarily selected within the unit area. The probability means the number of times when the size difference of the pore is found within the range when the size difference of the pores is measured 100 times within the unit area.

The waterproof breathable sheet according to another embodiment of the present invention includes a nanomembrane in which nanofibers are integrated into a nonwoven fabric including a plurality of pores, and the surface of the nanofiber includes a water repellent coating layer. The waterproof ventilation sheet has waterproof waterproofing property that does not leak at normal temperature (20 ° C, ± 5 ° C), water pressure of 1.5 m or more for 30 minutes or more, and acoustic transmission loss is less than 10 dB at 1000 Hz.

2, the waterproof breathable sheet 100 includes a nanofiber 10 in which nanofibers 11 are integrated into a nonwoven fabric including a plurality of pores, and the surface of the nanofiber 11 And a water repellent coating layer (12). Optionally, the nanomembrane 10 may further include an adhesive layer 20 on one or both surfaces thereof. 2, the waterproof ventilation sheet 100 may further include a support (not shown) for supporting the nanomembrane 10.

Particularly, the present invention further includes the water repellent coating layer 12 on the surface of the PVdF nanofiber 11 to maintain the super water-repellent performance in which the range of the waterproofable temperature and pressure (water pressure) is increased as compared with the existing PVdF, To prevent dust and contaminants from penetrating the dust and dirt.

Specifically, the water-repellent coating layer 12 may include a silicone-based water-repellent agent. The silicone-based water repellent agent is preferable in that it can add a high surface resistance performance and excellent thermal stability to the nanofiber 11.

The silicone-based water repellent is specifically selected from the group consisting of polysiloxane containing a siloxane bond, polydimethylsiloxane, oligosiloxane, methylphenylpolysiloxane, methoxysilane, ethoxysilane, propoxysilane, isopropoxysilane, and mixtures thereof And may include any one of the silicone-based polymers.

However, since the nanofibers 11 fabricated by electrospinning the fluoropolymer are regularly aligned / laminated, the cavity of the fiber is circular or polygonal, and the measured value of the acoustic transmission loss is high, And the pore may be blocked by the water-repellent coating layer 12, so that there is a possibility that the sound emission is lowered.

In the present invention, by adjusting the thickness of the water repellent coating layer 12 and the weight of the water repellent coating layer 12, the air permeability of the nanomembrane 10 and the size distribution of pores And the sound absorption loss and the diffuse reflection are suppressed, thereby lowering the measured value of the acoustic transmission loss.

The water repellent coating layer 12 may be applied to the nanoweb with the pore size distribution adjusted to further irregularize the thickness, shape, and pore size of the nanoweb, thereby lowering the measured value of the acoustic transmission loss and improving the sound transmission.

Specifically, the water repellent coating layer 12 is preferably applied with a thickness of 10 nm to 500 nm. If the thickness is less than 10 nm, the water repellency of the water repellent coating layer 12 may be insignificant. If the thickness exceeds 500 nm, the pore may be blocked to reduce the sound emission.

More specifically, the water repellent coating layer 12 preferably has a coating weight per area of 0.1 g / m 2 to 1 g / m 2. When the coating weight is less than 0.1 g / m 2, the water repellent effect is not expected when compared with before and after the water repellent coating of the nanofiber. If the coating weight exceeds 1 g / m 2, the pore size of the nanomembrane 10 is decreased, Lt; / RTI >

The waterproof breathable sheet according to another embodiment of the present invention includes a nanomembrane in which nanofibers are integrated into a nonwoven fabric including a plurality of pores. The nanofiber includes 100 parts by weight of a fluoropolymer and 1 part by weight of a water- Wherein the nanofiber has a diameter of 50 nm to 3000 nm, a thickness of 3 to 40 탆, a pore size of 0.1 to 5 탆, a porosity of 40 to 90% %to be. The waterproof ventilation sheet has waterproof waterproofing property that does not leak at normal temperature (20 ° C, ± 5 ° C), water pressure of 1.5 m or more for 30 minutes or more, and acoustic transmission loss is less than 10 dB at 1000 Hz.

In the present invention, the fluoro polymer and the fluorine-based water repellent and oil repellent additives are used together to improve the elastic modulus and the strength of the nanomembrane 10 in the production of the nano-web, and resistance to pressure deformation The waterproofness and oil repellency of the nanomembrane 10 can be further improved by increasing the water pressure of the increased water-permeable ventilation sheet and imparting super-water repellency and oil repellency to the nanomembrane 10.

The water-repellent oil additive may be selected from the group consisting of perfluoroacrylic monomers having a number of carbon bonds of 4 to 9, perfluorinated silicone monomers, perfluoroalcohol monomers, overbased urethane-based monomers, Based additives such as perfluorooctane sulfonic acid, perfluorooctane sulfonyl fluoride, perfluorooctanoic acid, perfluoroalkyl sulfonate, and the like, and more specifically, A fluoroalkyl group or a polyfluoroalkyl group.

When a general silicone additive or an acrylic additive is included, the waterproof property may be lower or similar to that of the fluorine-based additive, but the oil-repellent performance may be poor and durability of the air-permeable sheet may be lowered.

In the present invention, as described above, when the fluoropolymer is electrospun to control the electrospinning conditions during the manufacture of the nanofibers, the ventilation performance and the air permeability of the nanomembrane 10 are adjusted to improve the sound performance.

When the water-repellent breathable additive is included in an amount of 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the fluoropolymer, the condition that the acoustic transmission loss of the waterproof breathable sheet is less than 10 dB at 1000 Hz can be satisfied. The required water pressure (1500 mm H ₂ O) can be met.

The waterproof breathable sheet according to another embodiment of the present invention includes a nanomembrane in which nanofibers are integrated into a nonwoven fabric including a plurality of pores, and the nanomembrane has a machine direction (MD) (MD elastic modulus / TD elastic modulus) of the transverse direction (TD) elastic modulus is 1.5 to 10.0. The waterproof ventilation sheet has a waterproofing waterproofing property that does not leak at normal temperature (20 ° C ± 5 ° C), a water pressure of 1.5 m or more for 30 minutes or more, and an acoustic transmission loss of less than 10 dB at 1000 Hz.

However, the nano-web produced by electrospinning the PVdF may have a poor sound absorption due to the regularly oriented / laminated nanofibers constituting the nanofibers, because the pores in the fiber are circular or polygonal, and the absorption coefficient is high. In the present invention, the PVdF is electrospun to fix the orientation of the nano-web in the uniaxial direction when manufacturing the nano-web to control the microstructure of the nanofiber, in particular, the orientation of the nanofiber, thereby suppressing sound absorption and diffuse reflection, Lowering the distortion of the sound.

Specifically, conventionally, the orientation of the nanofibers in the nanowire fabricated by electrospinning PVdF is substantially equal in the longitudinal direction (MD) and the transverse direction (TD). However, cavities are generated by the uniform fiber orientation of the nanofibers, and when the acoustic waves pass through the cavities, sound absorption and diffuse reflection occur, resulting in distorted sound. In addition, the conventional nanomembrane can not satisfy the water pressure (1500 mmH ₂ O) required by the IPX 68 class by the cavity, and the water pressure standard can be attained by adding an additive such as a water repellent. However, water resistance can be improved by adding an additive such as the water repellent agent, but defects may occur during spinning, or adhesiveness between fibers may be insufficient, resulting in deterioration of handling properties.

However, if the orientation of the nanofibers is fixed in the uniaxial direction as in the present invention, the pores in the fibers become closer to the shape of a single character (not a circular or polygonal shape), thereby reducing the overall number of pores, And the sound absorption coefficient is lowered to improve the sound performance. At this time, since the orientation of the nanofibers is uniaxially fixed, the longest diameter of the linear pores is oriented in a direction substantially parallel to the longitudinal direction of the nanomembrane 10.

At this time, the linear pores have an aspect ratio (SD: LD) of the smallest diameter (SD) of the pores with respect to the longest diameter (LD) of the pores is 1: 2 to 1:50, : 5 to 1:50. When the aspect ratio (SD: LD) of the smallest diameter (SD) of the pores with respect to the longest diameter (LD) of the pores is less than 1: 2, pores are uniformly distributed and diffuse reflection occurs, If it exceeds 1:50, the pore may be deformed by the pressure such as water pressure or air pressure, and the waterproof performance or dustproof performance may be deteriorated.

As described above, as the orientation of the nanofiber is fixed in the uniaxial direction, the nanomembrane has an anisotropy (MD elastic modulus / TD elastic modulus) in a machine direction (MD) and a transverse direction (TD) 1.5 to 10.0, and more specifically 2.0 to 10.0. When the anisotropy (MD elastic modulus / TD elastic modulus) of the longitudinal direction elastic modulus and the lateral modulus of elasticity of the nanomembrane is 1.5 To 10.0, the condition that the acoustic transmission loss of the waterproof breathable sheet is less than 10 dB at 1000 Hz can be satisfied, and the water pressure (1500 mmH ₂ O) required by the IPX 68 class can be satisfied. The modulus of elasticity of the nanomembrane 10 may be determined by measuring the MD (Machine Direction) and the TD (Transverse Direction) ten times after applying ASTM D 882 and using the average value excluding the maximum value and the minimum value. The longitudinal direction or the machine direction (MD) of the nanomembrane is a length of the nanomembrane in the direction of movement of the roll when the nanomembrane is continuously produced in a roll-to-roll manner or in a direction in which the produced nanomembrane is wound, And the width direction of the nanomembrane or the transverse direction TD of the machine direction means a width direction in which the length is short in the longitudinal direction or the machine direction.

In addition, by fixing the orientation of the nanofibers in the uniaxial direction, the elastic modulus and strength in the longitudinal direction of the nanomembrane 10 are improved, and resistance to pressure deformation due to water pressure applied during water pressure is increased, 10 can be improved.

On the other hand, by controlling the electrospinning conditions during the production of nanofibers by electrospinning the PVdF, the air permeability of the nanomembrane 10 and the size distribution of the pores are controlled, thereby suppressing sound absorption and diffuse reflection, So that it is possible to have a better voice.

Through the above-described configurations, the absorption coefficient of the nanomembrane 10 may be less than 0.2 at 1000 Hz, and may be 0 to 0.1 at 1000 Hz. At this time, the sound absorption coefficient can be measured by an in-line method sound absorption test (ASTM E 1050-12), and the unit thereof is a constant. When the absorption coefficient of the nanomembrane 10 is 0.2 or more at 1000 Hz, a sound absorption effect for absorbing sound may be generated, so that sound performance such as sound loss and distortion may be deteriorated.

The acoustic transmission loss of the nanomembrane 10 may be less than 10 dB at 1000 Hz, and specifically less than 0 dB to 5 dB at 1000 Hz. In this case, the acoustic transmission loss can be measured by the test method of ASTM E 2611-09 by measuring the acoustical transmission loss of vertical incidence sound, and the measurement frequency band is 100 Hz to 5000 Hz at a 1/3 octave band center frequency. If the acoustic transmission loss of the nanomembrane 10 is 10 dB or more at 1000 Hz, the soundproof effect may occur, and the functionality of the waterproof ventilation sheet 100 may be degraded due to loss or distortion of sound. The acoustic transmission loss of the waterproof ventilation sheet 100 may be less than 10 dB at 1000 Hz as the acoustic transmission loss of the nanomembrane 10 is less than 10 dB at 1000 Hz.

Also, as the nanomembrane 10 includes the nanoweb fabricated by electrospinning the PVdF, the nanomembrane 10 may have an air permeability of 0.1 CFM to 20 CFM, specifically 0.5 CFM to 10 CFM Lt; / RTI > The air permeability of the nanomembrane 10 can be measured under the conditions of an area of 38 cm 2 and a static pressure of 125 Pa by applying the ASTM D 737 method. In this case, ㎤ / ㎠ / s can be converted into CFM, the conversion coefficient is 0.508016, and the unit is ft ³ / ft ² / min (CFM). If the air permeability of the nanomembrane 10 is less than 0.1 CFM, the permeability of sound may be lowered and the acoustic performance may be deteriorated. If the air permeability exceeds 20 CFM, the water pressure may be lowered and water may penetrate into the electronic device, .

In addition, since the nanomembrane 10 includes the nanoweb fabricated by electrospinning the PVdF, the nanomembrane 10 has a water pressure of 3000 mmH ₂ O or more, specifically, a water pressure of 5000 to 20000 mmH ₂ < / RTI > The water pressure of the nanomembrane ₁₀ can be measured at a point of 3 points on the water droplet by applying a pressure of 600 ㎜ H ₂ O / min at an area of 100 cm 2 by applying the KS K ISO 811 low pressure method.

In addition, since the nanomembrane 10 includes a nanoweb fabricated by electrospinning the PVdF, the nanomembrane 10 has a water repellency grade of 4 or more, specifically, a water repellency grade of 4 to 5 have. The water repellency of the nanomembrane 10 can be measured by the method specified in KS K 0590. If the water-repellency rating of the nanomembrane 10 is lower than 4, the nanomembrane may be wetted due to hydrophilicity with water, or water may penetrate to lower the water pressure, thereby deteriorating the waterproof performance.

The nanomembrane 10 may have a modulus of elasticity ranging from 1 MPa to 1000 MPa and a specific elastic modulus ranging from 5 MPa to 500 MPa . The modulus of elasticity of the nanomembrane 10 may be determined by measuring the MD (Machine Direction) and the TD (Transverse Direction) ten times after applying ASTM D 882 and using the average value excluding the maximum value and the minimum value. If the elastic modulus of the nanomembrane 10 is less than 1 MPa, it may be easily deformed by an external stimulus or an impact to reduce the dust / waterproof performance or sound distortion. If the elastic modulus of the nanomembrane 10 exceeds 1000 MPa, Defects such as cutting (punching) and deformation may occur. The waterproof and waterproof performance of the waterproof ventilation sheet 100 can be measured using a water pressure meter capable of applying a constant water pressure of 0 m to 20 m depth used in KS K ISO 811 for a predetermined time. At this time, a jig may be used to measure the waterproofness of the waterproof ventilation sheet 100 in the water pressure measuring device.

3 is a perspective view schematically showing an embodiment of a jig used for measuring the waterproofing waterproof property of the waterproof ventilation sheet 100 in the water pressure measuring instrument. 3, when the waterproof ventilation sheet 100 is fixed or adhered to the jig 200, water pressure resistance can be evaluated by applying a constant water pressure to the water pressure portion 210 using a water pressure meter for a predetermined period of time have. 3, the number of the pressure receiving portions 210 is 19, but the present invention is not limited thereto. For example, the pressure receiving portion 210 may include one, three, five, nine, twenty The number can be adjusted. The size of the perforation hole of the pressure receiving portion 210 is preferably smaller than the open area of the perforated waterproof sheet 100 and can be appropriately adjusted according to the size of the perforated waterproof sheet 100.

In order to confirm the waterproof performance in various environments, it is possible to evaluate the waterproofing property after pretreatment under low temperature, high temperature / high humidity, thermal shock condition. In the case of low temperature, it was evaluated after pretreatment at -20 ° C for 72 hours. In the case of high temperature / high humidity condition, it was evaluated after pretreatment at 50 ° C and humidity 95% for 72 hours. Thermal shock conditions were -40 ° C and 85 ° C for 1 hour It can be evaluated after repeating 30 cycles of maintaining one cycle.

The waterproof ventilation sheet 100 may be formed to have a thickness of at least 30 minutes at a room temperature (20 ° C ± 5 ° C), a water pressure of 1.5 m or more, specifically, a water pressure of 1.5 m to 6 m In the case of low temperature (measured after holding at -20 ° C for 72 hours) without leaking, it does not leak for 30 minutes or more at a water pressure of 1.5 m or more, specifically for 30 minutes or more at a water pressure of 1.5 m to 6 m, (At -40 ° C, at 50 ° C, 95% humidity, after 72 hours of holding), it does not leak for at least 30 minutes at a water pressure of 1.5 m or more, specifically for at least 30 minutes at a water pressure of 1.5 m to 6 m, And 85 ° C for 1 hour, respectively), it is possible to have a hydraulic waterproof property that does not leak more than 30 minutes at a water pressure of 1.5 m or more, specifically, 30 minutes or more at a water pressure of 1.5 m to 6 m have. When the waterproofing ventilation sheet 100 is waterproofed at room temperature (20 ° C ± 5 ° C), water pressure of 1.5 m or more, water pressure of 1.5 m or less at low temperature, water pressure of 1.5 m or more at high temperature / Water or moisture may penetrate into the waterproofing ventilation sheet 100 and the electronic equipment may be damaged.

For reference, the water pressure at the certain depth can be calculated by the following equation (2), and the water pressure in the ocean increases by 1 atmospheres every time the water depth drops by 10 m.

&Quot; (2) "

Water pressure (p) = pgz

(In Equation 2, p is the density of water (about 1.03 g / ㎤), g is 980 cm / sec ^2, z is under the surface of the sea water depth (cm))

The waterproof ventilation sheet 100 may have a breathability of 20 cc / min or more, specifically 20 cc / min to 150 cc / min, as the inclusion of the nanomembrane 10. The air permeability of the waterproof ventilation sheet 100 is measured by a gas permeability method in a capillary flow porometer (CFP) using a flow rate of air passing through a 1 mm diameter circular area for 1 minute under 1 PSI pressure Can be measured. When the air permeability of the waterproof breathable sheet 100 is less than 20 cc / min, air permeability is lowered to cause distortion of sound, or heat emission from an APU (Accelerated Processing Unit), a display or a BLU (Back Light Unit) .

The adhesive layer 20 is located on the surface of the nanomembrane 10 and specifically the periphery 20a of the adhesive layer 20 is located on the periphery of the surface of the nanomembrane 10, The central portion 20b of the layer 20 may be in the form of an open frame. The nanomembrane 10 is adhered to the inner surface of the vent hole of the housing of the electronic apparatus through the adhesive layer 20 and the vent hole of the housing of the electronic apparatus through the opening of the central portion 20b of the adhesive layer 20 It is possible to impart air permeability and waterproofness to the electronic device while blocking the air.

The shape and size of the opening of the central portion 20b of the adhesive layer 20 may be basically the same as the shape and size of the ventilation hole of the housing of the electronic apparatus. Specifically, the shape and size of the aperture 20a may be circular, oval, Rectangular, polygonal, P-shaped, and the like, but the present invention is not limited thereto.

1, the end of the peripheral portion 20a of the adhesive layer 20 may be formed to coincide with the end of the nanomembrane 10, and the peripheral portion 20a of the adhesive layer 20 May extend beyond the end of the nanomembrane 10 to cover the end of the nanomembrane 10.

The adhesive layer 20 may include any one of a pressure sensitive adhesive selected from the group consisting of polyacryl, polyamide, polyacrylamide, polyester, polyolefin, polyurethane, polysilicon, Liquid type or solid type, and may be a thermoplastic type, a heat-converting type, or a reactive curing type.

On the other hand, the adhesive layer 20 may be a double-sided adhesive tape. The double-sided adhesive tape may be a double-sided adhesive tape made of polyethylene terephthalate (PET), a polypropylene-based double-sided adhesive tape, a polyethylene-based double-sided adhesive tape, a polyimide double-sided adhesive tape, a nylon- Foam, silicone foam, acrylic foam, polyethylene foam, etc.), double-sided adhesive tape without substrate,

The waterproof ventilation sheet 100 may further include a protective substrate (not shown) that can protect the adhesive layer 20 before it is attached to the electronic apparatus.

The protective substrate may be made of a rubber or a silicone material, a polyester such as polyethylene terephthalate (PET) or polybutylene terephthalate, a polyolefin such as polypropylene, polyethylene, or polymethylpentene, a resin material such as polycarbonate, A paper material such as a high-temperature paper, a coated paper, an impregnated paper, and a synthetic paper, and a metal foil material such as aluminum and stainless steel.

For the purpose of preventing electrification, a conductive material may be coated on the protective substrate as required, or a conductive material mixed with a conductive material may be used. As a result, the waterproof ventilation sheet 100 can be prevented from being charged. The thickness of the protective sheet may be, for example, 10 탆 to 100 탆, specifically, 25 탆 to 50 탆. The surface of the protective substrate may be subjected to a corona discharge treatment, a plasma treatment, a frame plasma treatment, or the like to improve adhesion with the adhesive layer 20, and a primer layer or the like may be formed. The primer layer may be any one selected from the group consisting of polyethylene, polypropylene, styrenic copolymer, polyester, polyurethane, polyvinyl alcohol, polyethyleneimine, polyacrylate, polymethacrylate, A polymer material (made of an anchor coat) can be used.

When the waterproof ventilation sheet 100 does not further include the adhesive layer 20, when the waterproof ventilation sheet 100 is attached to the housing of the electronic apparatus, the pressure sensitive air permeable sheet 100 or electronic The waterproof breathable sheet (1) can be applied to the housing of the apparatus by screen printing, spray coating, gravure printing, transfer, powder coating or the like by direct screen printing, spraying, or ultrasonic welding without the pressure- 100 may be attached directly to the housing of the electronic device.

The waterproof ventilation sheet 100 may further include the support to reinforce the strength of the nanomembrane 10.

The support may be made of a material having a pore size larger than that of the nanomembrane 10 and having excellent gas permeability and excellent strength such as woven fabric, nonwoven fabric, mesh, net, sponge, foam, metal porous material, metal mesh, have. When heat resistance is required, a support made of a polyester, a polyamide, an aramid resin, a polyimide, a polyetherimide, a polyamideimide, a polyether sulfone, a fluororesin, an ultrahigh molecular weight polyethylene, a metal and the like can be used.

Specifically, the nonwoven fabric may be interlaid with the supporting body formed of a plurality of randomly oriented fibers. The nonwoven fabric may be interlaid, but may have a structure of individual fibers or filaments Sheet. The nonwoven fabric may be formed by a variety of processes including carding, garneting, air-laying, wet-laying, melt blowing, spunbonding, thermal bonding ), And stitch bonding. [0035] The term " stitch bonding " The fibers constituting the nonwoven fabric may include one or more polymer materials, and any of those generally used as a fiber-forming polymer material may be used, and specifically, a hydrocarbon-based fiber-forming polymer material may be used. For example, the fiber-forming polymeric material may be a polyolefin such as polybutylene, polypropylene and polyethylene; Polyesters such as polyethylene terephthalate and polybutylene terephthalate; Polyamides (nylon-6 and nylon-6,6); Polyurethane; Polybutene; Polylactic acid; Polyvinyl alcohol; Polyphenylene sulfide; Polysulfone; A fluid crystalline polymer; Polyethylene-co-vinyl acetate; Polyacrylonitrile; Cyclic polyolefins; Polyoxymethylene; Polyolefinic thermoplastic elastomers; And combinations thereof. However, the present invention is not limited thereto.

In addition, the method of laminating the support on the nanomembrane 10 may be simply performed by overlapping or bonding. For example, the bonding may be performed by a method such as adhesive lamination, thermal lamination, thermal vapor deposition, ultrasonic vapor deposition, or adhesion by a pressure sensitive adhesive. For example, when the support is laminated with the nanomembrane 10 by thermal lamination, a part of the support may be melted and adhered by heating. In this case, the supporter adheres to the nanomembrane 10 without using a pressure-sensitive adhesive, and unnecessary weight increase and decrease in air permeability can be avoided. In addition, the support and the nanomembrane 10 may be adhered using a fusion agent such as hot melt powder.

A method of manufacturing a waterproof breathable sheet according to another embodiment of the present invention includes the steps of preparing an electrospinning solution and electrospinning the prepared electrospinning solution so that the nanofibers are integrated into a nonwoven fabric including a plurality of pores Thereby producing a nanomembrane. According to the manufacturing method of the waterproof breathable sheet, a waterproof breathable sheet having a waterproof and waterproof property that does not leak at a normal temperature (20 ° C ± 5 ° C) and a water pressure of 1.5 m or more for 30 minutes or more and an acoustic transmission loss of less than 10 dB at 1000 Hz can do.

The method for manufacturing the waterproof breathable sheet can control the microstructure of the nanomembrane by controlling the electrospinning conditions to produce a waterproof breathable sheet having excellent water permeability and excellent waterproofing and water permeability.

First, the step of preparing the electrospinning solution is to prepare a solution containing a polymer for forming nanofibers through electrospinning. For example, the electrospinning solution may include polyvinylidene difluoride (PVdF) (N, N-dimethylacetamide), N, N-dimethyl formamide, dimethylsulphoxide, N-methyl-2-pyrolidone, triethyl phosphate may be prepared by mixing with any one solvent selected from the group consisting of triethylphosphate, methylethylketone, tetrahydrofuran, acetone, and mixtures thereof.

The electrospinning solution may further comprise a water-softening additive together with a fluoropolymer such as polyvinylidene difluoride (PVdF). The electrospinning solution may include 100 parts by weight of the fluoropolymer, 1 to 50 parts by weight of the water-repellent oil additive, and 250 to 2000 parts by weight of the solvent.

Next, the prepared electrospinning solution is electrospun to prepare a nanomembrane in which the nanofibers are integrated into a nonwoven fabric including a plurality of pores.

The electrospinning may be performed using the electrospinning apparatus shown in FIG. 4 is a schematic view of a nozzle-type electrospinning device. 4, the electrospinning is performed by a plurality of nozzles 3 to which a high voltage is applied by the high voltage generator 6 using the metering pump 2 in the solution tank 1 storing the electrospinning solution, The electrospinning solution is fed to the electrospinning solution by the difference in electric energy between the nozzle 3 or the tip of the electrospinning unit and the accumulation unit 4, that is, the voltage difference. The formed jet is whipped and stretched by the electric field to become thinner and the solvent is vaporized so that solid fibers are accumulated in the integrated portion 4. [ At this time, by regulating the micro-structure of the nanomembrane by controlling the electrospinning condition, it is possible to produce a waterproof ventilation sheet having excellent water permeability and excellent waterproofing and waterproofing properties.

The concentration of the electrospinning solution may be 5% to 35%, specifically 5% to 25%. The concentration means a percent concentration, and the percent concentration can be obtained as a percentage of the mass of the solute to the mass of the solution. For example, the concentration may be obtained by dividing the mass of the polymer contained in the electrospinning solution by the mass of the solution, and then multiplying by 100. If the concentration of the electrospinning solution is less than 5%, the polymer may not be produced due to the low content of the polymer, and may be injected into the beads. If the concentration exceeds 35%, the polymer may not be dissolved, The pressure may become high and leak or breakage of the solution may occur.

The viscosity of the electrospinning solution may be 100 cP to 10000 cP, specifically 200 cP to 5000 cP. The viscosity of the solution can be measured at a temperature of 23 DEG C by the KS M ISO 2555 method. If the viscosity of the electrospinning solution is less than 100 cP, the viscosity may be too low to produce fibers and may be injected onto the beads. If the viscosity exceeds 10000 cP, jets may not be formed during the spinning process, There may be a problem that the defects of the membrane increase.

Further, the electrospinning condition may be a voltage of 0 kV to 100 kV, specifically 20 kV to 70 kV. If the voltage exceeds 100 kV, sparks may be generated in a region susceptible to insulation during the spinning process, resulting in damage to the product or transfer or peeling of the product to the transfer roll during transfer due to static electricity.

The electrospinning condition may be a discharge rate of 0.01 cc / min to 100 cc / min, specifically 0.5 cc / min to 50 cc / min. When the discharge amount is less than 0.01 cc / min, the amount of the laminated fibers is small, resulting in a decrease in productivity or delamination. When the discharge amount exceeds 100 cc / min, the saturation concentration of the solvent in the chamber increases, And there is a problem that the product is finally reused and filmed.

The water-repellent coating layer-forming step includes the steps of: preparing a composition for forming a water-repellent coating layer; applying the composition for forming a water-repellent coating layer to the nanomembrane; and drying the nanomembrane coated with the composition for forming a water- can do.

The composition for forming a water repellent coating layer is specifically a polymer composed of a siloxane-containing polymer such as polysiloxane, polydimethylsiloxane, oligosiloxane, methylphenylpolysiloxane, methoxysilane, ethoxysilane, propoxysilane, isopropoxysilane, Based polymer may be one selected from the group consisting of silicon-based polymers.

The composition for forming a water repellent coating layer may be prepared by diluting the silicone polymer with any one solvent selected from the group consisting of water, isopropyl alcohol (IPA), ethanol, glycerol, and glycol.

The silicone-based polymer may be contained in an amount of 1 wt% to 50 wt% with respect to the total weight of the water repellent coating layer composition, and the content may be controlled according to a solvent. In one embodiment of the present invention, when the solvent is an aqueous emulsion, 20 to 40% by weight of the silicone-based polymer may be contained.

The composition for forming the water repellent coating layer preferably has a viscosity of 1 cP to 1000 cP in view of forming a fibrous coating layer of a nanomembrane. The viscosity of the composition can be measured at a temperature of 23 DEG C in accordance with the KSM ISO 2555 method. When the viscosity of the composition for forming a water repellent coating layer is less than 1 cP, it is difficult to form a coating layer having a thickness equal to or more than a certain thickness of the nanofibers. Thus, the surface resistance and antistatic effect may be insufficient. It is difficult to maintain the thickness of the water repellent coating layer at 10 nm to 500 nm, and a porosity of more than a certain level for securing the air permeability and acoustic performance can not be obtained.

The step of applying the composition for forming a water-repellent coating layer to the nanomembrane may be carried out by spraying, impregnating, printing, rolling, solution casting, gravure transfer coating by roll coating, screen coating, T- Or the like. At this time, the melting temperature of the composition for forming a water repellent coating layer is preferably 80 ° C to 300 ° C, more preferably 80 ° C to 200 ° C.

Next, in the drying step, the nanomembrane coated with the composition for forming a water repellent coating layer may be dried in an oven at 80 ° C to 200 ° C for 1 to 5 minutes.

If the drying conditions are less than 80 ° C for less than one minute, the coating layer may not be formed properly due to evaporation of the solvent in the water-repellent composition and the curing of the silicone-based polymer, May not be completely removed and peeling may occur or the coating may flow. If it is dried for more than 5 minutes at a temperature exceeding 200 ° C, there may be a problem that deformation may occur in the nanomembrane product itself. That is, in the case of proceeding within the above range, water as a solvent can be evaporated while maintaining the shape of the nanomembrane, and the coating layer of the water repellent agent of the nanofiber can be uniformly cured.

By uniaxially orienting the nanomembrane, it is possible to produce a waterproof breathable sheet having excellent water permeability, waterproofing and waterproofing properties and breathability, and enhancing stability and usability in a roll-to-roll process.

When the nanomembrane is uniaxially oriented, it is possible to control the orientation of the nanofibers to suppress sound absorption and diffuse reflection, and to lower a sound absorption coefficient to eliminate sound distortion. In addition, the uniaxial orientation of the nanomembrane can increase the tensile strength and elastic modulus in the longitudinal direction (MD) of the nanomembrane. Through this, the stability and usability in the in-line traveling during the roll-to-roll (R2R) process can be improved and the product yield can be increased. In addition, quality control can be stabilized by reducing deviation between existing lots (LOT).

Specifically, the uniaxial orientation of the nanomembrane may be performed by applying a tensile force of 1.5 to 20 times in the longitudinal direction to the width direction of the nanomembrane, and specifically applying a tensile force of 2 to 10 times . If the tensile force in the longitudinal direction is less than 1.5 times the tension in the width direction of the nanomembrane, anisotropy may not be imparted, isotropic properties are developed, negative absorption and diffuse reflection occur, and negative distortion may occur. If it is more than 20 times, the aggregation, strength and elongation modulus of the fibers may be lowered, resulting in breakage or tearing at the time of winding, resulting in deterioration of stability and usability. At this time, when the tensile force is applied only to the MD in the uniaxial orientation of the nanomembrane, and when the tensile force is not applied to the TD, i.e., when the tensile force applied to the TD is negative or zero, the width of the nanomembrane is reduced, The width of both sides of the nanomembrane should be at least fixed. In this case, the tensile force may be applied to the nanomembrane. Of course, in the present invention, uniaxial orientation can also be achieved by applying a tensile force only to the MD and applying a tensile force to the TD.

The method of uniaxially orienting the nanomembrane is not particularly limited in the present invention, and any method can be applied as long as it is conventionally a method of orienting a nanomembrane. For example, the uniaxial orientation may be achieved by a separate orientation device, and the integration condition of the integrated portion 4 may be adjusted in the electrospinning device, and the winding condition of the winding roller for winding the manufactured nanomembrane may be adjusted .

More specifically, for example, in the uniaxial orientation of the nanomembrane, the winding speed of the nanomembrane is adjusted to 0.01 m / min to 20 m / min, specifically 0.1 m / min to 10 m / min, and TR ( traverse speed from 0.001 m / min to 10 m / min, specifically from 0.01 m / min to 2 m / min. The TR speed means a speed at which the nanomembrane reciprocates in a direction perpendicular to the uniaxial orientation of the fiber, that is, in the width direction (TD). The nanomembrane may reciprocate the nanomembrane in the transverse direction (TD) during the electrospinning or the winding according to various reasons such as the uniform integration of the nanofibers irrespective of the position of the nozzle. When the winding speed and the TR speed are within the above range, an anisotropy (MD elastic modulus / TD elastic modulus) of the longitudinal elastic modulus and the width modulus of 1.5 to 10.0 can be produced.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[제조예 1: 통기성 방수 시트의 제조][Preparation Example 1: Preparation of breathable waterproof sheet]

(실시예 1-1)(Example 1-1)

An electrospinning solution was prepared by dissolving PVdF in dimethylacetamide at a concentration of 18% (w / w). The viscosity of the electrospinning solution was 3000 cP.

The electrospinning solution was electrospun by using the electrospinning device of FIG. 4 at a voltage of 60 kV and a discharge rate of 20 cc / min to prepare a nanomembrane.

The nano-membrane, the double-sided tape and the protective substrate were continuously introduced to adhere the lower surface of the double-sided tape to the upper surface of the nanomembrane, and the protective substrate was joined. Then, a waterproof breathable sheet was prepared by passing through a mold having a constant pressure and speed and cut to a certain size.

(실시예 1-2 내지 실시예 1-3)(Examples 1-2 to 1-3)

A waterproof breathable sheet was prepared in the same manner as in Example 1-1, except that the concentration, viscosity and electrospinning conditions of the electrospun solution in Example 1-1 were changed as shown in Table 1 below.

(실시예 1-4)(Examples 1-4)

An electrospinning solution was prepared by dissolving PVdF at a concentration of 18% (w / w) in a mixture of dimethylformamide and acetone (DMF 50%: acetone 50%, w / w) The viscosity of the electrospinning solution was 450 cP.

A waterproof breathable sheet was prepared in the same manner as in Example 1-1, except that the electrospinning solution was changed to the composition, viscosity and electrospinning conditions in Example 1-1 as shown in Table 1 below.

(비교예 1-1 및 비교예 1-2)(Comparative Example 1-1 and Comparative Example 1-2)

구분division	농도(%)density(%)	점도(cP)Viscosity (cP)	전압(kV)Voltage (kV)	토출량(cc/min)Discharge amount (cc / min)
실시예 1-1Example 1-1	1818	30003000	6060	2020
실시예 1-2Examples 1-2	1313	10001000	5555	2020
실시예 1-3Example 1-3	1010	800800	7070	5050
실시예 1-4Examples 1-4	1818	450450	6565	2525
비교예 1-1Comparative Example 1-1	3535	1200012000	8585	0.010.01
비교예 1-2Comparative Example 1-2	55	5050	7575	0.50.5

[실험예 1-1: 나노 멤브레인의 특성 측정][Experimental Example 1-1: Characteristic measurement of nanomembrane]

The diameters, thickness, pore size, porosity, basis weight, and pore size distribution of the nanofibers of the nanomembranes prepared in the above Examples and Comparative Examples were measured and shown in Table 2 below, and the air permeability, Water repellency and elastic modulus were measured and shown in Table 3 below.

The pore size and the pore distribution of the nanomembrane were measured by using a capillary flow porometer (CFP) specified in ASTM F316 to calculate the average pore size and the size of the pores in the diameter of the pores of the pore size in the narrowest interval The distribution was measured.

The thickness of the nanomembrane was measured by the thickness measurement method specified in KS K 0506 or KS K ISO 9073-2, ISO 4593.

The basis weight of the nanomembrane was measured by applying ASTM D 3776.

The porosity of the nanomembrane was measured according to Equation (1).

The size distribution of the pores of the nanomembrane is selected by selecting one pore existing within a unit area (cm ² ) randomly selected from one surface of the nanomembrane and 100 pores excluding the one pore, The number of pores of 100 nm or more was measured.

The air permeability of the nanomembrane was measured using an ASTM D 737 method under the conditions of an area of 38 cm 2 and a static pressure of 125 Pa. The ㎤ / ㎠ / s were calculated as ^{^{ft 3 / ft 2 / min (}} CFM). The conversion factor is 0.508016.

The water pressure of the nanomembrane was measured by applying pressure of 600 ㎜ H ₂ O / min at an area of 100 ㎠ by applying the KS K ISO 811 low pressure method to measure the pressure at three points on the water drop.

The water repellency of the nanomembrane was measured by the method described in KS K 0590.

The sound absorption coefficient was measured by an in-line method sound absorption test (ASTM E 1050-12).

The modulus of elasticity of the nanomembrane was measured by measuring the machine direction (MD) and the transverse direction (TD) 10 times using ASTM D 882, and the average value except for the maximum value and the minimum value was used.

구분division	나노 섬유 직경(㎛)Diameter of nanofiber (탆)	두께 (㎛)Thickness (㎛)	기공 크기(㎛)Pore size (탆)	평량 (g/㎡)Basis weight (g / ㎡)	기공도(%)Porosity (%)	기공 크기의 불규칙성(개)Pore size irregularities ()
실시예 1-1Example 1-1	0.3~2.00.3 to 2.0	2020	0.5~50.5 to 5	6.276.27	8383	90/10090/100
실시예 1-2Examples 1-2	0.3~3.00.3 to 3.0	3535	0.1~10.1 to 1	1313	8080	20/10020/100
실시예 1-3Example 1-3	0.1~1.00.1 to 1.0	1818	0.1~20.1 to 2	6.06.0	8181	60/10060/100
실시예 1-4Examples 1-4	0.1~0.70.1 to 0.7	2121	0.1~30.1 to 3	7.07.0	8282	70/10070/100
비교예 1-1Comparative Example 1-1	2.0~5.02.0 to 5.0	3535	2~102 to 10	2525	6060	9/1009/100
비교예 1-2Comparative Example 1-2	0.1~0.30.1 to 0.3	22	0.01~0.050.01 to 0.05	1.21.2	77	1/1001/100

구분division	공기투과도(CFM)Air permeability (CFM)	내수압(㎜H₂O)Water pressure (mmH ₂ O)	발수 등급Water-repellency rating	흡음계수Absorption coefficient	탄성률(MPa)Modulus of elasticity (MPa)
실시예 1-1Example 1-1	7.017.01	5,6005,600	4-5 급4-5	0.010.01	194194
실시예 1-2Examples 1-2	6.876.87	5,2705,270	4 급4th grade	0.080.08	220220
실시예 1-3Example 1-3	3.043.04	12,82012,820	5 급5th grade	0.020.02	6565
실시예 1-4Examples 1-4	1.971.97	11,48011,480	5 급5th grade	0.010.01	200200
비교예 1-1Comparative Example 1-1	9.019.01	1,4501,450	1 급1st grade	0.320.32	6767
비교예 1-2Comparative Example 1-2	0.090.09	700700	1 급1st grade	0.510.51	1010

Referring to Tables 2 and 3, it can be seen that the examples 1-1 to 1-4 show that the absorption coefficient is lowered by controlling the microstructure of the nanomembrane, that is, the diameter, thickness and size distribution of the nanofiber, have.

[실험예 1-2: 방수성 통기 시트의 특성 측정][Experimental Example 1-2: Measurement of properties of waterproof breathable sheet]

The acoustic permeation loss, waterproofness (normal temperature, low temperature, high temperature / high humidity, thermal shock) and air permeability of the waterproof breathable sheet produced in the above Examples and Comparative Examples were measured and shown in Table 4 below.

The acoustic transmission loss of the waterproof breathable sheet was evaluated by the acoustic transmission loss test. Specifically, the acoustic transmission loss was evaluated by applying (ASTM E 2611-09).

The waterproofness of the waterproof breathable sheet was measured using a water pressure meter capable of applying a constant water pressure of 0 m to 20 m depth used in KS K ISO 811 for a predetermined time. In the case of the low temperature, the sample was pretreated at -20 ° C for 72 hours and then evaluated. After the pretreatment at 50 ° C and 95% humidity for 72 hours, the samples were evaluated at a temperature of -40 ° C and 85 ° C Were kept for 1 hour, respectively, and the cycle was repeated 30 times and then evaluated under the conditions of room temperature (20 DEG C +/- 5 DEG C).

The air permeability of the waterproof ventilation sheet was measured by a gas permeability method of a capillary flow porometer (CFP) using a flow rate of air passing through a 1 mm diameter circular area for 1 minute under 1 PSI pressure.

구분division	음향투과손실(dB)Acoustic transmission loss (dB)	수압방수(상온)Water pressure (room temperature)	수압방수(저온)Water pressure (low temperature)	수압방수 (고온고습)Water pressure (high temperature and high humidity)	수압방수(열충격)Waterproofing (thermal shock)	통기성 (cc/min@1PSI)Air permeability (cc / min @ 1PSI)
실시예 1-1Example 1-1	22	4m, 50분4m, 50 min	4m, 50분4m, 50 min	4m, 45분4m, 45 minutes	4m, 45분4m, 45 minutes	120120
실시예 1-2Examples 1-2	33	4m, 80분4m, 80 min	4m, 75분4m, 75mins	4m, 60분4m, 60 minutes	4m, 60분4m, 60 minutes	100100
실시예 1-3Example 1-3	0.10.1	6m, 300분6 m, 300 min	6m, 300분6 m, 300 min	6m, 250분6m, 250 min	6m, 280분6m, 280m	8080
실시예 1-4Examples 1-4	0.10.1	6m, 300분6 m, 300 min	6m, 300분6 m, 300 min	6m, 260분6m, 260m	6m, 290분6m, 290m	7070
비교예 1-1Comparative Example 1-1	1010	1.5m, 3분 1.5m, 3 minutes	1.5m, 3분1.5m, 3 minutes	1.5m, 1분1.5m, 1 minute	1.5m, 2분1.5m, 2 minutes	160160
비교예 1-2Comparative Example 1-2	3030	1.5m, 1분1.5m, 1 minute	1.5m, 1분1.5m, 1 minute	1.5m, 1분1.5m, 1 minute	1.5m, 1분1.5m, 1 minute	1One

Referring to Table 4, in Examples 1-1 to 1-4, the acoustic transmission loss was less than 10 dB and the waterproofing waterproof property (normal temperature, low temperature, high temperature / high humidity, thermal shock) However, in the case of the comparative examples 1-1 and 1-2, the acoustic transmission loss was 10 dB or more, and the waterproof and waterproof property (room temperature, low temperature, and high temperature) was not less than 20 cc / min (@ 1 PSI) High temperature / high humidity, thermal shock) leaked even at a water pressure of 1.5 m.

That is, in Examples 1-1 to 1-4, polyvinylidene fluoride was electrospun to control the microstructure of the nanomembrane by adjusting the electrospinning conditions during production, It can be seen that a waterproof ventilation sheet having excellent air permeability was produced.

[제조예 2: 통기성 방수 시트의 제조][Preparation Example 2: Preparation of breathable waterproof sheet]

(실시예 2-1)(Example 2-1)

An electrospinning solution was prepared by dissolving PVdF in dimethylacetamide at a concentration of 15% (w / w). The viscosity of the electrospinning solution was 2000 cP.

The electrospun solution was electrospun using the electrospinning device of FIG. 4 under the conditions of a voltage of 55 kV and a discharge rate of 5 cc / min to prepare a nanoweb.

The silicone water repellent was diluted with water to a concentration of 1% to prepare a solution for forming a water repellent coating layer having a viscosity of 30 cP. The prepared solution was sprayed onto the surface of the prepared nanomembrane by spraying to give a weight of 0.15 g / m 2. And then dried in an oven at 80 DEG C for 3 minutes to prepare a nanomembrane.

The nanomembrane, the double-sided adhesive tape and the protective substrate were continuously charged to adhere the lower surface of the double-sided adhesive tape to the upper surface of the nanomembrane, and the protective substrate was laminated. Then, a waterproof breathable sheet was produced by passing through a mold having a constant pressure and speed and casting to a certain size.

(실시예 2-2 내지 실시예 2-4)(Examples 2-2 to 2-4)

A waterproof breathable sheet was prepared in the same manner as in Example 2-1, except that the concentration, viscosity, electrospinning condition, and water repellent agent application amount of the electrospun solution in Example 2-1 were changed as shown in Table 5 below .

(비교예 2-1 및 비교예 2-2)(Comparative Example 2-1 and Comparative Example 2-2)

Except that the silicone water-repellent layer was formed in Example 2-1, the concentration, viscosity, and electrospinning conditions of the electrospinning solution were carried out in the same manner to prepare a water-permeable ventilating sheet.

구분division	농도(%)density(%)	점도(cP)Viscosity (cP)	전압(kV)Voltage (kV)	토출량(cc/min)Discharge amount (cc / min)	발수제 도포량(g/㎡)Water repellent application amount (g / ㎡)
실시예 2-1Example 2-1	1515	20002000	5555	55	0.150.15
실시예 2-2Example 2-2	2020	50005000	6060	55	0.150.15
실시예 2-3Example 2-3	1515	20002000	5555	55	0.50.5
실시예 2-4Examples 2-4	2020	50005000	6060	55	0.50.5
비교예 2-1Comparative Example 2-1	1515	20002000	5555	55	00
비교예 2-2Comparative Example 2-2	2020	50005000	6060	55	00

[실험예 2-1: 나노 멤브레인의 특성 측정][Experimental Example 2-1: Characteristic measurement of nanomembrane]

The diameter, thickness, pore size, porosity and basis weight of the nanofibers of the nanomembranes prepared in the above Examples and Comparative Examples were measured and shown in Table 6 below. The nanofiber nanofibers were measured for air permeability, water pressure, water repellency, The results are shown in Table 7 below.

The method for measuring the diameter, thickness, pore size, porosity and basis weight of the nanofibers of the nanomembrane and the air permeability, water pressure, water repellency, and elastic modulus of the nanomembrane are the same as in Experimental Example 1-1.

구분division	나노 섬유 직경(㎛)Diameter of nanofiber (탆)	두께(㎛)Thickness (㎛)	기공 크기(㎛)Pore size (탆)	평량(g/㎡)Basis weight (g / ㎡)	기공도(%)Porosity (%)
실시예 2-1Example 2-1	0.1~10.1 to 1	1515	0.7~1.50.7 to 1.5	7.17.1	73.673.6
실시예 2-2Example 2-2	0.16~1.80.16 to 1.8	1616	0.5~1.20.5 to 1.2	7.27.2	74.974.9
실시예 2-3Example 2-3	0.15~1.50.15 to 1.5	1616	0.5~1.30.5 to 1.3	7.77.7	73.173.1
실시예 2-4Examples 2-4	0.2~20.2 to 2	1717	0.3~1.00.3 to 1.0	7.87.8	74.474.4
비교예 2-1Comparative Example 2-1	0.08~10.08 to 1	1515	0.7~1.50.7 to 1.5	6.96.9	74.374.3
비교예 2-2Comparative Example 2-2	0.16~20.16 to 2	1616	0.5~1.20.5 to 1.2	7.37.3	74.374.3

구분division	공기투과도(CFM)Air permeability (CFM)	내수압(㎜H₂O)Water pressure (mmH ₂ O)	발수 등급Water-repellency rating	탄성률(MD방향, ㎫)Modulus of elasticity (MD direction, MPa)	접촉각(°)Contact angle (°)
실시예 2-1Example 2-1	3.23.2	1000010000	4~5급4 to 5	6262	137137
실시예 2-2Example 2-2	3.13.1	1000010000	4~5급4 to 5	6666	137137
실시예 2-3Example 2-3	3.03.0	1200012000	5급5th grade	7070	142142
실시예 2-4Examples 2-4	3.03.0	1200012000	5급5th grade	7171	143143
비교예 2-1Comparative Example 2-1	3.23.2	70007000	4급4th grade	4949	122122
비교예 2-2Comparative Example 2-2	3.13.1	70007000	4급4th grade	5252	123123

Referring to Tables 6 and 7, the microstructure of the nanomembrane, that is, the diameter and thickness of the nanofiber, was controlled according to the concentration of the polymer, and the permeability was maintained according to the amount of the water repellent applied The water repellency performance is improved.

[실험예 2-2: 방수성 통기 시트의 특성 측정][Experimental Example 2-2: Measurement of properties of waterproof breathable sheet]

The acoustic transmission loss, waterproofing waterproofness (room temperature, low temperature, high temperature / high humidity, thermal shock) and air permeability of the waterproof breathable sheet produced in the above Examples and Comparative Examples were measured and shown in Table 8 below.

The method of measuring acoustic transmission loss, waterproofing waterproof property (room temperature, low temperature, high temperature / high humidity, thermal shock) and air permeability of the waterproof breathable sheet is the same as in Experimental Example 1-2.

구분division	음향투과손실(dB)Acoustic transmission loss (dB)	수압방수(상온)Water pressure (room temperature)	수압방수(저온)Water pressure (low temperature)	수압방수 (고온고습)Water pressure (high temperature and high humidity)	수압방수(열충격)Waterproofing (thermal shock)	통기성 (cc/min@1PSI)Air permeability (cc / min @ 1PSI)
실시예 2-1Example 2-1	0.30.3	4m, 100분4m, 100mins	4m, 80분4m, 80 min	4m, 60분4m, 60 minutes	4m, 80분4m, 80 min	60~7060 to 70
실시예 2-2Example 2-2	0.20.2	4m, 100분4m, 100mins	4m, 80분4m, 80 min	4m, 60분4m, 60 minutes	4m. 80분4m. 80 minutes	60~7060 to 70
실시예 2-3Example 2-3	0.40.4	4m, 150분 4m, 150 min	4m, 120분4m, 120 minutes	4m, 100분4m, 100mins	4m, 120분4m, 120 minutes	50~6050 to 60
실시예 2-4Examples 2-4	0.50.5	4m, 150분4m, 150 min	4m, 120분4m, 120 minutes	4m, 100분4m, 100mins	4m, 120분4m, 120 minutes	50~6050 to 60
비교예 2-1Comparative Example 2-1	0.20.2	4m, 3분4m, 3 minutes	4m, 2분4m, 2 min	4m, 0분4m, 0 min	4m, 3분4m, 3 minutes	60~7060 to 70
비교예 2-2Comparative Example 2-2	0.30.3	4m, 5분4m, 5mins	4m, 2분4m, 2 min	4m, 0분4m, 0 min	4m, 2분4m, 2 min	60~7060 to 70

Referring to Table 8, in Examples 2-1 to 2-4, the acoustic transmission loss was less than 10 dB and the waterproofing waterproof property (normal temperature, low temperature, high temperature / high humidity, thermal shock) And the air permeability is not less than 20 cc / min (@ 1 PSI). However, in the case of Comparative Examples 2-1 and 2-2, the acoustic permeation loss and air permeability are similar to those in Examples 2-1 to 2-2 Similar water pressure (water temperature, low temperature, high temperature / high humidity, thermal shock) leaked even at a water pressure of 4 m.

In other words, in Examples 2-1 to 2-4, polyvinylidene fluoride was electrospun to control the microstructure of the nanomembrane by controlling the electrospinning conditions during production, thereby improving the waterproofing and waterproofing properties, It is understood that a waterproof ventilation sheet having almost no acoustic transmission loss is produced.

[제조예 3: 통기성 방수 시트의 제조][Preparation Example 3: Preparation of breathable waterproof sheet]

(실시예 3-1)(Example 3-1)

100 parts by weight of a fluoropolymer PVdF and 15.4 parts by weight of a fluorine-containing water-repellent oil additive KF GUARD 910 (Nika Korea) having 6 carbon bonds were dissolved in 653.6 parts by weight of dimethylformamide at a concentration of 15% (w / w) .

The viscosity of the electrospinning solution containing the water-repellent oil additive was 3000 cP.

The electrospinning solution was electrospun using the electrospinning device of FIG. 4 under the conditions of a voltage of 50 kV and a discharge rate of 6 cc / min to prepare a nanomembrane.

The nanomembrane, the double-sided tape and the protective substrate were continuously charged, and the lower surface of the double-sided tape was bonded to the upper surface of the nanomembrane and the protective substrate was laminated. Then, a waterproof breathable sheet was produced by passing through a mold having a constant pressure and speed and casting to a certain size.

(실시예 3-2 내지 실시예 3-3)(Examples 3-2 to 3-3)

A waterproof breathable sheet was prepared in the same manner as in Example 3-1, except that the concentration, viscosity, and electrospinning conditions of the electrospun solution in Example 3-1 were changed as shown in Table 9 below.

(비교예 3-1)(Comparative Example 3-1)

In Example 3-1, the same as Example 3-1, except that the water-and-oil additive was not used, and the concentration, viscosity, and electrospinning conditions of the electrospinning solution were changed as shown in Table 9 below To prepare a waterproof ventilation sheet.

구분division	발수발유 첨가제 농도(%)Water and oil additive concentration (%)	고분자 및 발수발유 첨가제 농도(%)Concentration of Polymer and Water-Solubility Additives (%)	점도(cP)Viscosity (cP)	전압(kV)Voltage (kV)	토출량(cc/min)Discharge amount (cc / min)
실시예 3-1Example 3-1	22	1515	30003000	5050	66
실시예 3-2Example 3-2	22	2020	10001000	5555	66
실시예 3-3Example 3-3	22	1010	600600	4545	66
비교예 3-1Comparative Example 3-1	00	1515	30003000	5050	66

[실험예 3-1: 나노 멤브레인의 특성 측정][Experimental Example 3-1: Characteristic measurement of nanomembrane]

The diameter, thickness, pore size, porosity and basis weight of the nanofibers of the nanomembrane prepared in the above Examples and Comparative Examples were measured and shown in Table 10 below. The nanofiber nanofibers were measured for air permeability, water pressure, water repellency, The results are shown in Table 11 below.

구분division	나노 섬유 직경(㎛)Diameter of nanofiber (탆)	두께 (㎛)Thickness (㎛)	기공 크기(㎛)Pore size (탆)	평량(g/㎡)Basis weight (g / ㎡)	기공도(%)Porosity (%)
실시예 3-1Example 3-1	0.15~10.15 to 1	1515	0.5~1.50.5 to 1.5	77	73.973.9
실시예 3-2Example 3-2	0.5~20.5 to 2	1717	0.3~1.20.3 to 1.2	7.67.6	7575
실시예 3-3Example 3-3	0.1~0.80.1 to 0.8	1313	0.7~1.50.7 to 1.5	66	74.274.2
비교예 3-1Comparative Example 3-1	0.15~10.15 to 1	1515	0.6~1.50.6 to 1.5	6.96.9	74.374.3

구분division	공기투과도(CFM)Air permeability (CFM)	내수압(㎜H₂O)Water pressure (mmH ₂ O)	발수 등급Water-repellency rating	탄성률(MD방향, ㎫)Modulus of elasticity (MD direction, MPa)	접촉각(°)Contact angle (°)
실시예 3-1Example 3-1	3.13.1	1000010000	4-5 급4-5	6969	133133
실시예 3-2Example 3-2	2.72.7	90009000	4-5 급4-5	8282	131131
실시예 3-3Example 3-3	3.43.4	1100011000	5 급5th grade	5757	140140
비교예 3-1Comparative Example 3-1	3.03.0	70007000	4 급4th grade	7070	122122

Referring to Table 10 and Table 11, Examples 3-1 to 3-3 and Comparative Example 3-1 show the nanostructure microstructure at the concentration of the fluoropolymer and the water-repellent oil additive, that is, the diameter of the nanofiber, , Pore size and so on, while keeping the air permeability as it is, it is confirmed that there is a difference between the waterproof performance and the water repellency according to the presence or absence of the water and oil additive.

[실험예 3-2: 방수성 통기 시트의 특성 측정][Experimental Example 3-2: Measurement of properties of waterproof breathable sheet]

The acoustic permeation loss, waterproofing waterproof property (room temperature, low temperature, high temperature / high humidity, thermal shock) and air permeability of the waterproof breathable sheet produced in the above Examples and Comparative Examples are shown in Table 12 below.

구분division	음향투과손실(dB)Acoustic transmission loss (dB)	수압방수(상온)Water pressure (room temperature)	수압방수(저온)Water pressure (low temperature)	수압방수 (고온고습)Water pressure (high temperature and high humidity)	수압방수(열충격)Waterproofing (thermal shock)	통기성 (cc/min@1PSI)Air permeability (cc / min @ 1PSI)
실시예 3-1Example 3-1	0.20.2	4m, 100분4m, 100mins	4m, 80분4m, 80 min	4m, 50분4m, 50 min	4m, 80분4m, 80 min	60~7060 to 70
실시예 3-2Example 3-2	0.30.3	4m, 80분4m, 80 min	4m, 60분4m, 60 minutes	4m, 40분4m, 40 minutes	4m, 60분4m, 60 minutes	60~7060 to 70
실시예 3-3Example 3-3	0.10.1	4m, 120분4m, 120 minutes	4m, 100분4m, 100mins	4m, 70분4m, 70mins	4m, 100분4m, 100mins	60~7060 to 70
비교예 3-1Comparative Example 3-1	0.20.2	4m, 3분4m, 3 minutes	4m, 2분4m, 2 min	4m, 0분4m, 0 min	4m, 3분4m, 3 minutes	60~7060 to 70

Referring to Table 12, in Examples 3-1 to 3-3, the acoustic transmission loss was less than 10 dB and the waterproofing waterproof property (normal temperature, low temperature, high temperature / high humidity, thermal shock) However, in the case of Comparative Example 3-1, the acoustic transmission loss is similar, but the waterproofing performance at the room temperature, the low temperature, the high temperature / high humidity, and the thermal shock performance is similar. Is low.

That is, in Examples 3-1 to 3-3, the polyvinylidene fluoride and the water-repellent oil additive are electrospun to control the microstructure of the nanomembrane by adjusting the concentration of the spinning solution during the production, In addition, it was found that the waterproof breathable sheet having improved waterproofness, waterproofness and breathability, and water repellent oil additive were further improved.

[제조예 4: 통기성 방수 시트의 제조][Preparation Example 4: Preparation of breathable waterproof sheet]

(실시예 4-1)(Example 4-1)

At this time, the nanomembrane was uniaxially stretched in the machine direction by adjusting the winding speed of the nanomembrane to 5.0 m / min and controlling the TR speed to 0.8 m / min.

(실시예 4-2 내지 실시예 4-3)(Examples 4-2 to 4-3)

A waterproof breathable sheet was prepared in the same manner as in Example 4-1, except that the preparation conditions of the nanomembrane in Example 4-1 were changed as shown in Table 13 below.

(비교예 4-1)(Comparative Example 4-1)

A waterproof breathable sheet was prepared in the same manner as in Example 4-1, except that the biaxial orientation of the nanomembrane was adjusted to 1.05: 1.0 by controlling the ratio of the winding speed of the nanomembrane to the TR speed Respectively.

구분division	농도(%)density(%)	점도(cP)Viscosity (cP)	전압(kV)Voltage (kV)	토출량(cc/min)Discharge amount (cc / min)	배향 비율(권취속도/TR속도)Orientation ratio (winding speed / TR speed)
실시예 4-1Example 4-1	1818	30003000	6060	2020	6.256.25
실시예 4-2Example 4-2	1313	10001000	5555	2020	7.757.75
실시예 4-3Example 4-3	1010	800800	7070	5050	10.2510.25
비교예 4-1Comparative Example 4-1	3535	1200012000	8585	0.010.01	1.051.05

[실험예 4-1: 나노 멤브레인의 형상 관찰][Experimental Example 4-1: Observation of shape of nanomembrane]

SEM photographs of the nanomembranes prepared in Example 4-1 and Comparative Example 4-1 are shown in FIGS. 5 and 6, respectively.

5 and 6, the pores of the nanomembrane prepared in Example 4-1 have an aspect ratio (SD) of the smallest diameter (SD) of the pore to the longest diameter (LD) of the pore, : LD) is 1: 2 to 1: 50, and the longest diameter (LD) of the pores is oriented in a direction parallel to the longitudinal direction of the nanomembrane.

On the other hand, the pores of the nanomembrane prepared in Comparative Example 4-1 had an aspect ratio (SD: LD) of the smallest diameter (SD) of the pores with respect to the longest diameter (LD) of the pores of 1: 1: 1.5, and it can be observed that the longest diameter (LD) of the pores is randomly oriented.

[실험예 4-2: 나노 멤브레인의 특성 측정][Experimental Example 4-2: Characteristic measurement of nanomembrane]

The thickness, the basis weight, the longitudinal direction elastic modulus, the lateral direction elastic modulus and anisotropy of the nanomembrane prepared in the above Examples and Comparative Examples were measured and shown in Table 14 below. The results are shown in Table 14. The air permeability, water pressure, porosity, The absorption coefficient was measured and is shown in Table 15 below.

The basis weight of the nanomembrane was measured by applying ASTM D 3776.

The porosity of the nanomembrane was measured according to Equation (1).

구분division	두께 (㎛)Thickness (㎛)	중량 (g/㎡)Weight (g / ㎡)	탄성률 (MD, ㎫)Modulus of elasticity (MD, MPa)	탄성률 (TD, ㎫)Modulus of elasticity (TD, MPa)	이방성 (MD/TD)Anisotropy (MD / TD)	배향성Orientation
실시예 4-1Example 4-1	2020	6.276.27	194194	31.531.5	6.26.2	일축spurn
실시예 4-2Example 4-2	3535	1313	220220	2626	8.58.5	일축spurn
실시예 4-3Example 4-3	1818	6.06.0	6565	8.98.9	7.37.3	일축spurn
비교예 4-1Comparative Example 4-1	3535	2525	6767	6262	1.11.1	이축Binocular

구분division	공기투과도 (CFM)Air permeability (CFM)	내수압(㎜H₂O)Water pressure (mmH ₂ O)	기공도(%)Porosity (%)	발수성Water repellency	흡음계수Absorption coefficient
실시예 4-1Example 4-1	7.017.01	5,6005,600	8383	4-5급4-5	0.010.01
실시예 4-2Example 4-2	6.876.87	5,2705,270	8080	4급4th grade	0.080.08
실시예 4-3Example 4-3	3.043.04	12,82012,820	8181	5급5th grade	0.020.02
비교예 4-1Comparative Example 4-1	9.019.01	1,4501,450	6060	1급1st grade	0.320.32

Referring to Tables 14 and 15, it can be seen that Examples 4-1 to 4-3 lowered the absorption coefficient by controlling the microstructure of the nanofibers of the nanomembrane, particularly the orientation of the nanofibers.

[실험예 4-3: 방수성 통기 시트의 특성 측정][Experimental Example 4-3: Measurement of properties of waterproof breathable sheet]

The acoustic permeation loss, waterproofing (water temperature, low temperature, high temperature / high humidity, thermal shock) and air permeability of the waterproof breathable sheet prepared in the above Examples and Comparative Examples were measured and shown in Table 16 below.

구분division	음향투과손실(dB)Acoustic transmission loss (dB)	수압방수(상온)Water pressure (room temperature)	수압방수(저온)Water pressure (low temperature)	수압방수 (고온고습)Water pressure (high temperature and high humidity)	수압방수(열충격)Waterproofing (thermal shock)	통기성 (cc/min@1PSI)Air permeability (cc / min @ 1PSI)
실시예 4-1Example 4-1	22	4m, 50분4m, 50 min	4m, 50분4m, 50 min	4m, 45분4m, 45 minutes	4m, 45분4m, 45 minutes	120120
실시예 4-2Example 4-2	33	4m, 80분4m, 80 min	4m, 75분4m, 75mins	4m, 60분4m, 60 minutes	4m, 60분4m, 60 minutes	100100
실시예 4-3Example 4-3	0.10.1	6m, 300분6 m, 300 min	6m, 300분6 m, 300 min	6m, 250분6m, 250 min	6m, 280분6m, 280m	8080
비교예 4-1Comparative Example 4-1	1010	1.5m, 3분 1.5m, 3 minutes	1.5m, 3분1.5m, 3 minutes	1.5m, 1분1.5m, 1 minute	1.5m, 2분1.5m, 2 minutes	160160

Referring to Table 16, in Examples 4-1 to 4-3, the acoustic transmission loss was less than 10 dB, the waterproofing waterproof property (room temperature, low temperature, high temperature / high humidity, thermal shock) However, in the case of the comparative example 4-1, the acoustic transmission loss is not less than 10 dB and the waterproof and waterproof property (room temperature, low temperature, high temperature / high humidity, Thermal shock) leaked even at a water pressure of 1.5 m.

That is, in Examples 4-1 to 4-3, polyvinylidene fluoride is electrospun and uniaxially aligned during manufacture to control the microstructure of the nanomembrane, particularly the orientation of the nanofibers, A waterproof ventilation sheet having excellent waterproofing and waterproofing properties and air permeability was produced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments, but various modifications and changes may be made without departing from the scope of the invention. To those of ordinary skill in the art.

[Description of Symbols]

1: solution tank

2: metering pump

3: Nozzle

4:

6: High voltage generator

100: Waterproof ventilation sheet

10: nanomembrane

11: nanofiber 12: water repellent coating layer

20: Adhesive layer

20a: peripheral portion 20b: central portion

200: jig

210:

The present invention relates to a waterproof breathable sheet and a method of manufacturing the same, wherein the waterproof breathable sheet is used for controlling the microstructure of the nanomembrane, that is, controlling the diameter, thickness and size distribution of the nanofiber or controlling the orientation of the nanofiber , Suppressing sound absorption and diffuse reflection, lowering the sound absorption coefficient, forming a water repellent coating layer on the nanomembrane to improve waterproof, dustproof and anti-fouling performance, lowering the acoustic transmission loss measurement value, By further including an additive, the water resistance is further improved, and the elastic modulus and strength of the nanomembrane are improved, thereby increasing the resistance to pressure deformation due to the water pressure applied during the water pressure, thereby improving the water pressure.

The waterproof ventilation sheet is used in various electronic apparatuses such as mobile apparatuses, electronic apparatuses such as hearing aids, communication apparatuses such as radio transmitters, automobile head lamps, and the like, thereby imparting air permeability to the electronic apparatuses, And waterproof to prevent penetration of water / liquid into the electronic device and dustproof to prevent contamination / dust penetration can be given to the electronic device.

Claims

Wherein the nanofibers comprise a nanomembrane integrated into a nonwoven fabric comprising a plurality of pores,

Waterproof breathable sheet with waterproof waterproofing that does not leak at normal temperature (20 ℃ ± 5 ℃), water pressure over 1.5 m for 30 minutes, and acoustic transmission loss less than 10 dB at 1000 Hz.
The method according to claim 1,

Wherein the nanofiber has a diameter of 50 nm to 3000 nm, a thickness of 3 to 40 탆, a pore size of 0.1 to 5 탆, and a porosity of 40 to 90%.
3. The method of claim 2,

The nanomembrane is characterized in that the nanofibers are irregularly oriented and laminated so that the size distribution of the pores is irregular,

Wherein the irregular pore size distribution has a probability of finding pores having a pore size difference of 100 nm or more per unit area (cm 2 ) of the nanomembrane of 10/100 or more.
The method according to claim 1,

Wherein the surface of the nanofibers comprises a water repellent coating layer.
The method according to claim 1,

Wherein the nanofiber includes 100 parts by weight of a fluoropolymer and 1 to 50 parts by weight of a water-repellent oil additive.
The method according to claim 1,

Wherein the nanomembrane has a machine direction (MD) elastic modulus and a transverse direction (TD) elastic modulus anisotropy (MD elastic modulus / TD elastic modulus) of 1.5 to 10.0.
The method according to claim 6,

The nanomembrane has a shape of a date (1 character) having an aspect ratio (SD: LD) of the smallest diameter (SD) of the pore to the longest diameter (LD) of the pore is 2 to 50,

And the longest diameter (LD) of the pores is oriented in a direction parallel to the longitudinal direction of the nanomembrane.
The method according to claim 1,

The absorption coefficient of the nanomembrane is less than 0.2 at 1000 Hz, the acoustic transmission loss is less than 10 dB at 1000 Hz,

Wherein the nanomembrane has an air permeability of 0.1 CFM to 20 CFM, a water pressure of 3000 mmH 2 O or more, a water repellency of 4 or more, an elastic modulus of 1 MPa to 1000 MPa, a basis weight of 0.5 g / M < 2 >.
The method according to claim 1,

The waterproof ventilation sheet was subjected to high temperature / high humidity conditions (50 DEG C, 95% humidity, 72 hours, no water leaks for at least 30 minutes at a water pressure of 1.5 m or more in the case of waterproof waterproof property at low temperature (Measured after repeating 30 cycles of one cycle maintaining -40 ° C and 85 ° C for 1 hour respectively) without leaking at a water pressure of 1.5 m or more for 30 minutes or more and 1.5 m or more It does not leak more than 30 minutes under water pressure,

Wherein the waterproof breathable sheet has a breathability of 20 cc / min (@ 1 PSI) or more.
The method according to claim 1,

Wherein the nanofiber is made of polyvinylidene difluoride (PVdF).
Preparing an electrospinning solution, and

And electro-spinning the prepared electrospinning solution to prepare a nanomembrane in which the nanofibers are integrated into a nonwoven fabric including a plurality of pores,

A method for producing a waterproof breathable sheet having a waterproof waterproofing property that does not leak at a room temperature (20 ° C ± 5 ° C), a water pressure of 1.5 m or more for 30 minutes or more, and an acoustic transmission loss of less than 10 dB at 1000 Hz.
12. The method of claim 11,

The concentration of the electrospinning solution is 5% to 35%, the viscosity is 100 cP to 10000 cP,

Wherein the electrospinning condition is a voltage of 0 kV to 100 kV and a discharge amount of 0.01 cc / min to 100 cc / min.
12. The method of claim 11,

Wherein the waterproof breathable sheet further comprises a water repellent coating layer on the surface of the nanofibers.
12. The method of claim 11,

Wherein the electrospinning solution comprises 100 parts by weight of a fluoropolymer, 1 to 50 parts by weight of a water-repellent oil additive, and 250 to 2000 parts by weight of a solvent.
12. The method of claim 11,

Wherein the waterproof breathable sheet further comprises uniaxial orientation of the nanomembrane.
16. The method of claim 15,

Wherein the uniaxial orientation of the nanomembrane is performed by applying a tensile force of 1.5 to 20 times in the longitudinal direction to the width direction of the nanomembrane.
16. The method of claim 15,

In the uniaxial orientation of the nanomembrane, the winding speed of the nanomembrane is adjusted to 0.01 m / min to 20 m / min, and the TR (traverse) speed is adjusted to 0.001 m / min to 10 m / min. A method for manufacturing a waterproof breathable sheet.