Waterproof sound-transmitting sheet and method for manufacturing waterproof sound-transmitting sheet

Abstract

This invention discloses a waterproof sound-transmitting sheet. The waterproof sound-transmitting sheet includes: a waterproof sound-transmitting layer having a waterproof function and configured to transmit sound; a first adhesive layer attached to a first surface of the waterproof sound-transmitting layer; and a second adhesive layer attached to a second surface of the waterproof sound-transmitting layer located on the opposite side of the first surface, wherein the waterproof sound-transmitting layer includes a non-porous layer without pores and a porous layer laminated on the non-porous layer and containing pores.

Description

Technical Field

[0001] This application relates to a waterproof sound-transmitting sheet and a method for manufacturing the waterproof sound-transmitting sheet, and more specifically, to a lightweight, highly waterproof, and efficient sound-transmitting sheet and a method for manufacturing the waterproof sound-transmitting sheet. Background Technology

[0002] The use of mobile electronic devices such as portable terminals, digital cameras, and laptops has been increasing recently. Because these mobile electronic devices are used while being carried, they need to be waterproof. However, sound holes are formed in the parts where speakers or microphones are installed, and water or dust can enter the electronic device through these sound holes.

[0003] Therefore, a waterproof sound-transmitting sheet is installed in the sound hole, allowing sound to pass through while blocking water or dust. The manufacturing of the waterproof sound-transmitting sheet should balance waterproofing and sound transmission efficiency.

[0004] Regarding waterproof sound-transmitting sheets, Korean Patent Application Publication No. 10-2010-0041839 (April 22, 2010) discloses a structure formed from a porous polytetrafluoroethylene (PTFE) membrane. However, since conventional waterproof sound-transmitting membranes are formed solely from a porous PTFE membrane, the following problem exists: as the usage time increases, the micropore size of the porous membrane gradually increases due to external impacts, sound pressure, etc., thereby reducing its waterproof performance. Summary of the Invention

[0005] Technical issues

[0006] The purpose of this disclosure is to provide a waterproof sound-transmitting sheet and a method for manufacturing the waterproof sound-transmitting sheet, the waterproof sound-transmitting sheet comprising a porous layer formed by electrospinning a solution containing a polymer material and a solvent, and a non-porous layer formed by dissolving the porous layer with a solvent remaining in the lower part of the porous layer.

[0007] Furthermore, the purpose of this disclosure is to provide a waterproof sound-transmitting sheet and a method for manufacturing the waterproof sound-transmitting sheet, the waterproof sound-transmitting sheet comprising a porous layer and a non-porous layer of a nano-network structure in which fibers and beads are mixed by electrospinning a solution containing polymer materials and solvent.

[0008] Solution to the technical problem

[0009] A waterproof sound-transmitting sheet according to an embodiment of the present disclosure includes a waterproof sound-transmitting layer having a waterproof function and configured to transmit sound, a first adhesive layer attached to a first surface of the waterproof sound-transmitting layer, and a second adhesive layer attached to a second surface of the waterproof sound-transmitting layer located on the opposite side of the first surface, wherein the waterproof sound-transmitting layer includes a non-porous layer without pores and a porous layer laminated on the non-porous layer and including pores.

[0010] A method for manufacturing a waterproof sound-transmitting sheet according to embodiments of the present disclosure includes: preparing a collection support; preparing a spinning solution comprising a polymer material and a solvent; forming a porous layer having a mesh structure laminated by electrospinning the spinning solution onto a surface of the collection support such that fibers are interlaced; and forming a non-porous layer by dissolving a portion of the porous layer adjacent to the one surface of the collection support with a solvent contained in the spinning solution being spun.

[0011] Beneficial effects of the invention

[0012] Because the waterproof sound-transmitting sheet according to the embodiments of this disclosure has a porous layer formed on its upper part and a non-porous layer formed on its lower part, it is lighter in weight and has better elasticity compared to conventional waterproof sound-transmitting sheets formed only by a non-porous membrane.

[0013] Since the waterproof sound-transmitting sheet according to the embodiments of the present disclosure has a porous layer formed on its upper part and a non-porous layer formed on its lower part, it can transmit sound more effectively through vibration and has higher durability compared to a waterproof sound-transmitting layer formed only by a porous layer.

[0014] The waterproof sound-transmitting sheet according to embodiments of the present disclosure includes a porous layer and a non-porous layer of a nano-network structure in which fibers and beads are mixed. Thus, even after prolonged exposure to a high-pressure environment, the elastic resilience of the waterproof sound-transmitting sheet is improved due to the connection structure between the beads and fibers of the waterproof sound-transmitting sheet, which is to be restored to its original shape, thereby preventing the deterioration of sound characteristics. Attached Figure Description

[0015] Figure 1 This is a diagram showing the state of a waterproof sound-transmitting sheet according to an embodiment of the present disclosure and an electronic device attached to the waterproof sound-transmitting sheet.

[0016] Figure 2 This is an exploded perspective view of a waterproof sound-transmitting sheet according to an embodiment of the present disclosure.

[0017] Figure 3 This is a diagram illustrating a waterproof sound-transmitting layer according to an embodiment of the present disclosure.

[0018] Figure 4 and 5This is a diagram showing the upper surface of a waterproof sound-transmitting layer according to an embodiment of the present disclosure.

[0019] Figures 6 to 9 This is a schematic diagram illustrating a method for manufacturing a waterproof sound-transmitting layer according to an embodiment of the present disclosure.

[0020] Figure 10 This is a cross-sectional view of a waterproof sound-transmitting layer according to an embodiment of the present disclosure.

[0021] Figure 11 This is a diagram showing the lower surface of a waterproof acoustic layer according to an embodiment of the present disclosure.

[0022] Figure 12 This is a flowchart illustrating a method for manufacturing a waterproof sound-transmitting layer according to an embodiment of the present disclosure. Detailed Implementation

[0023] In the following description, the most preferred embodiments of this disclosure will be described with reference to the accompanying drawings, so as to describe the disclosure in detail to the extent that those skilled in the art can readily implement the technical ideas of the disclosure. First, when adding reference numerals to components in each drawing, it should be noted that the same components should, as far as possible, have the same reference numerals even when shown in different drawings. Furthermore, in describing embodiments of the invention, detailed descriptions of related known configurations or functions will be omitted when it is determined that such detailed descriptions may obscure the essential points of the invention.

[0024] Figure 1 This diagram illustrates the state of a waterproof sound-transmitting sheet according to an embodiment of the present disclosure and an electronic device attached to the waterproof sound-transmitting sheet. (Refer to...) Figure 1 The waterproof sound-transmitting sheet 200 can be attached to the interior of the electronic device 110 to transmit sound between the interior and exterior of the electronic device 110 while preventing liquids or foreign substances from entering the electronic device 110 from the exterior.

[0025] The first surface of the waterproof sound-transmitting sheet 200 can be attached to the interior of the housing (or casing) of the electronic device 110, and the second surface of the waterproof sound-transmitting sheet 200 located on the opposite side of the first surface can be attached to the component 120 inside the electronic device 110.

[0026] According to one embodiment, component 120 may be a sound module 120 such as a speaker module or a microphone module, but is not limited thereto. The sound module may include a sound element and a circuit board on which the sound element is mounted.

[0027] According to an embodiment, the waterproof sound-transmitting sheet 200 may include: a waterproof sound-transmitting layer 210 having waterproof or dustproof functionality and configured to transmit sound; a first adhesive layer 220 attached to a first surface of the waterproof sound-transmitting layer 210 and configured to be attached to an electronic device 110; and a second adhesive layer 230 attached to a second surface of the waterproof sound-transmitting layer 210 located on the opposite side of the first surface and configured to be attached to a sound module.

[0028] Therefore, the waterproof sound-transmitting sheet 200 can prevent liquids or foreign substances from entering the sound module 120 from the outside of the electronic device 110. In addition, the waterproof sound-transmitting sheet 200 can transmit the sound generated by the speaker module to the outside of the electronic device 110 (e.g., to the user), or transmit the sound generated externally to the microphone module.

[0029] Simultaneously, when the external pressure on the electronic device 110 increases, the internal pressure between the waterproof acoustic sheet 200 and the sound module 120 may increase. As the internal pressure continues to increase, the pressure applied to the waterproof acoustic sheet 200 increases, thereby potentially causing the waterproof acoustic sheet 200 to stretch. The waterproof acoustic sheet 200 according to the embodiments of this disclosure not only possesses pressure resistance that will not be damaged even in high-pressure environments of 10 bar or higher, but also can recover its original shape even when the high-pressure environment is removed.

[0030] Figure 2 This is an exploded perspective view of a waterproof sound-transmitting sheet according to an embodiment of the present disclosure. (Refer to...) Figure 2 The waterproof sound-transmitting sheet 200 can be formed by bonding a waterproof sound-transmitting layer 210, a first adhesive layer 220, and a second adhesive layer 230 together.

[0031] The waterproof sound-transmitting layer 210 can be formed from a thin film having a predetermined shape. According to an embodiment, the waterproof sound-transmitting layer 210 can be a thin film having various shapes, such as circular, elliptical, and polygonal.

[0032] Depending on the required sound transmission and waterproof performance of the device to which it is applied, the waterproof sound transmission layer 210 may be a thin film with a thickness of about 5 μm to 100 μm, but is not limited thereto. Furthermore, depending on the embodiment, the waterproof sound transmission layer 210 may also be formed with a thickness of 5 μm or less or 100 μm or more, taking into account the thickness of the electronic device to which it is applied.

[0033] The waterproof sound-transmitting layer 210 can be made of a material with very high elasticity (high elasticity) and non-porous properties to provide waterproof performance under high water pressure. For example, the waterproof sound-transmitting layer 210 can be made of a high elasticity material, such as latex, polyurethane (PU), or thermoplastic polyurethane (TPU).

[0034] The waterproof sound-transmitting layer 210 according to embodiments of the present disclosure may include a non-porous membrane formed by electrospinning to provide waterproof performance under high water pressure. For example, the waterproof sound-transmitting layer 210 may be manufactured by electrospinning a polymer material to form a polymer material layer with a mesh structure. In particular, the waterproof sound-transmitting layer 210 according to embodiments of the present disclosure may be formed by electrospinning a solution containing a polymer material and a solvent, such that at least a portion of the polymer material layer with a mesh structure is dissolved by the solvent to form a non-porous layer.

[0035] In this context, the polymeric material may include, for example, aromatic polyesters such as polyamide, polyimide, polyamide-imide, poly(meta-phenylene isophthalamide), polysulfone, polyetherketone, polyetherimide, polyethylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polytetrafluoroethylene, polydiphenoxyphosphazene, and poly(bis(2-(2-methoxyethoxy)phosphazenes)) polyphosphazenes, including polyurethanes and polyether polyurethanes, polyurethane copolymers such as cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate. In addition, polymeric materials may include polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene), perfluoropolymers, polyvinyl chloride or polyvinylidene chloride and copolymers thereof, polyethylene glycol dialkyl ethers and polyethylene glycol derivatives (including polyethylene glycol dialkyl esters), polyoxides (including poly(oxymethylene-oligoethylene-oxygen), polyethylene oxide and polypropylene oxide), polyvinyl acetate, poly(vinylpyrrolidone-vinyl acetate), polystyrene and polystyrene-acrylonitrile copolymers, polyacrylonitrile, polyacrylonitrile copolymers including polyacrylonitrile methyl methacrylate copolymers, polymethyl methacrylate, polymethyl methacrylate copolymer polymers and mixtures thereof.

[0036] When the waterproof sound-transmitting layer 210 is formed using an electrospinning process, the thickness of the waterproof sound-transmitting layer 210 can be easily adjusted, and a waterproof sound-transmitting layer 210 with a small thickness can be easily manufactured. In particular, when the waterproof sound-transmitting layer 210 includes a non-porous layer, since the thinner the waterproof sound-transmitting layer 210, sound vibrations on one side can be transmitted more effectively to the other side, the thickness of the waterproof sound-transmitting layer 210 can be made as small as possible when using an electrospinning process, thereby further increasing the sound transmission performance.

[0037] The waterproof sound-transmitting layer 210 according to embodiments of the present disclosure may include a non-porous layer and has higher waterproof performance than a waterproof sound-transmitting layer that only includes a porous layer. In particular, when the waterproof sound-transmitting layer is formed only of a porous layer, when high pressure is applied to the waterproof sound-transmitting layer, cracks may appear in the waterproof sound-transmitting layer due to the expansion of the multiple pores, thus the waterproof performance is very likely to decrease. On the other hand, the waterproof sound-transmitting layer according to the present disclosure may include a non-porous layer and will not be damaged or deformed even under pressures of 5 bar, preferably 10 bar or higher.

[0038] The first adhesive layer 220 is formed of a thin film having a predetermined shape and an opening therein. For example, the first adhesive layer 220 is formed along the waterproof sound-transmitting layer 210 of a thin film having various shapes such as circular, elliptical, and polygonal. In this case, the first adhesive layer 220 may include an opening for sound transmission. For example, the first adhesive layer 220 may be an annular shape with an opening at the center, but embodiments of this disclosure are not limited thereto.

[0039] The first adhesive layer 220 can be bonded to a first surface (e.g., the lower surface) of the waterproof sound-transmitting layer 210. According to an embodiment, the first surface (e.g., the lower surface) of the first adhesive layer 220 can be attached to the electronic device 110, and a second surface (e.g., the upper surface) of the first adhesive layer 220 located on the opposite side of the first surface can be attached to the first surface (e.g., the lower surface) of the waterproof sound-transmitting layer 210.

[0040] According to an embodiment, the first adhesive layer 220 may be attached to the region in which the sound hole formed in the electronic device 110 is formed.

[0041] The first adhesive layer 220 can be formed by bonding a film having an adhesive surface formed on a single surface and a hot melt formed from thermoplastic resin in the form of particles or film. For example, the first adhesive layer 220 can also be formed by laminating a hot melt and a single-sided adhesive film.

[0042] The second adhesive layer 230 is formed of a thin film having a predetermined shape and an opening therein. For example, the second adhesive layer 230 is formed along the waterproof sound-transmitting layer 210 of a thin film having various shapes such as circular, elliptical, and polygonal. In this case, the second adhesive layer 230 may include an opening for sound transmission. For example, the second adhesive layer 230 may be an annular shape with an opening at the center, but embodiments of this disclosure are not limited thereto.

[0043] The second adhesive layer 230 can be bonded to the second surface (e.g., the upper surface) of the waterproof sound transmission layer 210. According to an embodiment, the second surface (e.g., the upper surface) of the second adhesive layer 230 can be attached to the sound module 120, and the first surface (e.g., the lower surface) of the second adhesive layer 230 located on the opposite side of the second surface can be attached to the second surface (e.g., the upper surface) of the waterproof sound transmission layer 210.

[0044] According to the embodiment, the second adhesive layer 230 can be attached to the input and output sound areas of the sound module 120.

[0045] The second adhesive layer 230 can also be formed by bonding a film having an adhesive surface formed on a single surface and a hot melt formed from thermoplastic resin in the form of particles or film. For example, the second adhesive layer 230 can also be formed by laminating a hot melt and a single-sided adhesive film.

[0046] Figure 3 This is a diagram illustrating a waterproof sound-transmitting layer according to an embodiment of the present disclosure. (Refer to...) Figure 3 The waterproof sound transmission layer 210 may include a non-porous layer 211 and a porous layer 213.

[0047] The non-porous layer 211 can be a layer of polymer material that does not contain pores. According to an embodiment, the non-porous layer 211 can have a structure in which pores are removed by dissolving and bonding (and aggregating) a laminated polymer material layer having a nano-network structure formed by an electrospinning method with a solvent.

[0048] The porous layer 213 may comprise a layer of laminated polymer material having a nano-network structure formed by an electrospinning method. According to embodiments, the porous layer 213 may have a porous nano-network structure in which multiple microfiber bundles are alternately laminated. In this specification, a nano-network structure refers to a structure in which microfiber bundles with diameters ranging from tens of nanometers to thousands of nanometers are laminated by interlacing with each other, but embodiments of this disclosure are not limited thereto.

[0049] The non-porous layer 211 can form the lower layer of the waterproof sound-transmitting layer 210, and the porous layer 213 can form the upper layer of the waterproof sound-transmitting layer 210. According to the embodiment, the ratio of the thickness of the non-porous layer 211 to the total thickness of the waterproof sound-transmitting layer 210 can be 50% to 95%, preferably 80% to 90%.

[0050] Since the waterproof sound-transmitting layer 210 according to the embodiments of the present disclosure includes a non-porous layer 211 disposed thereunder and a porous layer 213 disposed thereupon, the waterproof sound-transmitting sheet has a lighter weight and better elasticity than a waterproof sound-transmitting layer formed only of a non-porous layer, and is more efficient in transmitting sound through vibration and has higher durability compared to a waterproof sound-transmitting layer formed only of a porous layer.

[0051] Figure 4 and 5 This is a diagram showing the upper surface of a waterproof sound-transmitting layer according to an embodiment of the present disclosure. (Refer to...) Figure 4 and 5 The image shows the upper surface of the waterproof sound-transmitting layer 210, namely the upper surface of the porous layer 213.

[0052] Figure 4 These are scanning electron microscope (SEM) images captured in secondary electron (SE) mode. Figure 5 These are SEM images captured in backscattered electron (BSE) mode.

[0053] The porous layer 213 may include fibers 213a, beads 213b and pores 213c.

[0054] Fiber 213a can be a polymer fiber formed by electrospinning an electrospinning solution containing a polymer material. When the electrospinning solution is electrospinned, the solvent contained in the solution evaporates, and microfibers 213a are formed as the polymer material stretches.

[0055] The porous layer 213 comprises a plurality of fibers 213a with different thicknesses and lengths, and the plurality of fibers 213a may intersect each other to form a network structure. For example, the thickness (or diameter) of the fibers 213a may be 50 to 500 nm, preferably 70 to 250 nm, but the embodiments of this disclosure are not limited thereto.

[0056] Beads 213b can be blocky polymer materials disposed on porous layer 213. Beads 213b can be blocks of polymer materials formed by winding or aggregating polymer fibers formed by electrospinning. For example, the thickness (or diameter) of beads 213b can be 0.3 to 5 μm, preferably 0.8 to 3 μm, but the embodiments disclosed herein are not limited thereto.

[0057] As the flow rate of the electrospinning solution increases, the humidity of the surrounding environment increases, and the voltage applied during the electrospinning process increases, a large number of beads 213b can be formed, but the embodiments disclosed herein are not limited thereto.

[0058] According to the embodiments, beads 213b can be formed at both ends of fiber 213a, but are not limited thereto, and can be formed on the inner side of both ends of fiber 213a.

[0059] A pore 213c is a channel or hole through which air can pass and can be formed in the porous layer 213. According to an embodiment, the pore 213c can be a gap or space created by fibers 213a laminated together through interlacing.

[0060] The ratio of fibers 213a to beads 213b in the porous layer 213 can be from 3:7 to 7:3. In this specification, the ratio of fibers 213a to beads 213b can be the ratio of the area of ​​fibers 213a and the area of ​​beads 213b to the total area of ​​the porous layer 213, or the ratio of the weight of fibers 213a and the weight of beads 213b to the total weight of the porous layer 213.

[0061] As the ratio of fiber 213a to bead 213b increases, the elongation of the waterproof sound-transmitting layer 210 improves, thus improving sound transmission performance, but the pressure resistance (resilience) may deteriorate. Conversely, as the ratio of fiber 213a to bead 213b decreases, the sound transmission performance of the waterproof sound-transmitting layer 210 decreases, but the pressure resistance can be improved.

[0062] Since the waterproof sound-transmitting layer 210 according to the embodiments of this disclosure includes a non-porous layer 211 and a porous layer 213, the waterproof sound-transmitting layer 210 can be lightweight and have good elasticity, can transmit sound effectively, and can have good durability under high pressure. Furthermore, by considering both sound transmission performance and pressure resistance, the porous layer 213 includes fibers 213a and beads 213b in an appropriate ratio, resulting in good sound transmission performance and pressure resistance.

[0063] Specifically, the fibers 213a and beads 213b of the porous layer 213 can be connected, and the elastic force of the fibers 213a can be constrained by the beads 213b. Therefore, the elastic resilience of the waterproof sound-transmitting layer 210 can be increased. For example, even when the waterproof sound-transmitting layer 210 is stretched under high pressure, it can return to its original shape when the high pressure is removed. Therefore, the sound characteristics of the waterproof sound-transmitting sheet 200 can remain undegraded.

[0064] Figures 6 to 9 This is a diagram illustrating a method for manufacturing a waterproof sound-transmitting layer according to an embodiment of the present disclosure.

[0065] Reference Figure 6 The waterproof sound-transmitting layer 210 can be manufactured by an electrospinning method. According to an embodiment, the waterproof sound-transmitting layer 210 can be formed by spinning an electrospinning solution into a collector 320 through a spinning nozzle 310.

[0066] The spinning nozzle 310 can be a device for electrospinning nanofibers using an electrospinning solution. According to an embodiment, the spinning nozzle 310 may have an orifice through which the electrospinning solution flows, the orifice being exposed at the end of the spinning nozzle 310, and the electrospinning solution flowing through the orifice being ejected from the end of the spinning nozzle 310 and spun into nanofibers.

[0067] Electrospinning solutions can include polymer materials and solvents. In other words, an electrospinning solution can be a solution obtained by dissolving a polymer material in a solvent.

[0068] The collector 320 can be disposed on the lower part spaced apart from the spinning nozzle 310. The collector 320 can be grounded, thereby accumulating fibers generated by the charged spinning solution. That is, a voltage can be applied to the spinning solution flowing into the orifice of the spinning nozzle 310 to charge the spinning solution, and the charged spinning solution can be ejected in the form of nanofibers to the outside of the spinning nozzle 310 and accumulated in the grounded collector 320, thereby forming a waterproof sound-transmitting layer 210.

[0069] According to the embodiment, the collector 320 can be implemented in the form of an electrical conductor, such as a metal plate or a rotating conveyor belt. In this case, a collection support 240 can be provided on the collector 320, and a waterproof sound-transmitting layer 210 can be collected on the collection support 240. That is, when fibers accumulate in the collection support 240 provided on the collector 320, a waterproof sound-transmitting layer 210 is formed.

[0070] The collection bracket 240 can be transported on the collector 320.

[0071] According to the embodiment, the collection holder 240 is formed of a membrane-type non-porous component. For example, the collection holder can be one of release paper, art paper, coated paper, and glossy paper. For example, a non-porous waterproof membrane can be coated on the surface of the collection holder 240 on which a waterproof sound-transmitting layer 210 is formed.

[0072] Reference Figure 7 A porous layer 213 is formed by electrospinning the electrospinning solution through a spinning nozzle 310. According to an embodiment, when the electrospinning solution containing a polymer material and a solvent is ejected through the spinning nozzle 310, the polymer material contained in the electrospinning solution is laminated onto the collection support 240 in the form of fibers, thereby forming the porous layer 213 on the collection support 240. In this case, the solvent contained in the electrospinning solution can also be spun onto the collection support 240 together.

[0073] According to the embodiment, the voltage applied to the spinning nozzle 310 can be 95 to 105 kV, the distance between the collector 320 and the tip of the spinning nozzle 310 can be 190 to 220, and the flow rate of the electrospinning solution spun through the spinning nozzle 310 can be 15 to 30 μl / min / hole.

[0074] The porous layer 213 can be formed in the form of a membrane on one surface of the collection support 240. According to an embodiment, the porous layer 213 can be a porous nanomesh, in which multiple microfibers are laminated by interlacing with each other. For example, the porous layer 213 can be a waterproof layer.

[0075] As per the above reference Figure 4 and 5 The porous layer 213 may include fibers 213a, beads 213b, and pores 213c.

[0076] The polymeric material contained in the electrospinning solution may include thermoplastic elastomers or polyvinylidene fluoride (PVDF). According to an embodiment, the thermoplastic elastomer may be thermoplastic polyurethane (TPU).

[0077] According to embodiments of this disclosure, the weight ratio of PVDF in the polymer material can be as high as 20 wt%. For example, when the polymer material includes TPU or PVDF, the weight ratio of TPU to PVDF can be from 100:0 to 80:20. PVDF, as a hydrophobic material, is advantageous in forming waterproof sound-transmitting sheets; however, when its content exceeds 20 wt%, it is difficult to form non-porous sheets, and the restoring force for recovering the waterproof sound-transmitting sheet from deformation under external force is weak. Due to the weak restoring force, poor sound characteristics result. Therefore, it is important to form an electrospinning solution at an appropriate weight ratio of PVDF.

[0078] According to embodiments, the viscosity of the electrospinning solution can be 100-400 cp, preferably 180-250 cp. As described above, considering sound transmission performance and pressure resistance, the waterproof sound-transmitting layer 210 according to embodiments of this disclosure may include an appropriate ratio of fibers 213a and beads 213b. Since the ratio between fibers 213a and beads 213b can be determined based on the viscosity of the electrospinning solution, the determination of viscosity is important. When the viscosity of the electrospinning solution is 500 cp or greater, the ratio of beads 213b decreases (e.g., less than a predetermined reference value), and when the viscosity of the electrospinning solution is 100 cp or less, the ratio of fibers 213a may decrease (e.g., less than a predetermined reference value).

[0079] According to an embodiment, the temperature of the environment in which electrospinning is performed can be 24 to 36°C, preferably 28 to 34°C. According to an embodiment, the humidity of the environment in which electrospinning is performed can be 30% to 75%, preferably 45% to 60%.

[0080] Reference Figure 8 A non-porous layer 211 is formed on a portion of the porous layer 213. According to an embodiment, the non-porous layer 211 may be formed from the portion of the porous layer 213 adjacent to the collection support 240.

[0081] As described above, the surface 241 of the collecting support 240, on which the waterproof sound transmission layer 210 is formed, can be coated with a non-porous waterproof membrane. When an electrospinning solution containing polymer material and solvent is ejected through the spinning nozzle 310, the polymer material is laminated onto the collecting support 240 in the form of fibers, and the solvent is also laminated onto the collecting support 240.

[0082] In this scenario, most of the solvent ejected onto the collecting support 240 typically evaporates into the air, but some unevaporated solvent may accumulate on the collecting support 240 (i.e., the lower layer of the porous layer 213). Therefore, a portion of the porous layer 213 (i.e., the portion adjacent to a surface 241 of the collecting support 240) can come into contact with the solvent, and the fibers forming the porous layer 213 can be dissolved by the solvent. As a result, the fibers, laminated by interlacing, are entangled, and the pores formed between the fibers may become blocked, thus a non-porous layer 211 can be formed on a portion (the lower surface) of the porous layer 213.

[0083] In particular, according to embodiments of the present disclosure, since one surface 241 of the collecting support 240 is coated with a waterproof membrane, the evaporation of solvents spun onto the collecting support 240 can be suppressed, thereby further promoting the formation of the non-porous layer 211.

[0084] Furthermore, according to embodiments of this disclosure, the porous layer 213 includes fibers 213a and beads 213b. When the beads 213b are dissolved in a solvent, the formation of a non-porous layer 211 is further promoted compared to a porous layer formed solely of fibers, because the beads 213b become entangled with a plurality of fibers 213a adjacent to the beads 213b. Furthermore, when the beads 213b are dissolved in a solvent, the formation of a non-porous layer 211 is further promoted compared to a porous layer formed solely of fibers, because the beads 213b effectively block the pores 213c formed between the fibers 213a.

[0085] Using the above method, a portion of the porous layer 213 is formed into a non-porous layer 211 by means of a solvent.

[0086] Reference Figure 8 The lower surface of the porous layer 213 can be dissolved by a solvent to form a non-porous layer 211, and the non-porous layer 211 can be formed to a predetermined thickness.

[0087] The thickness of the non-porous layer 211 can be adjusted by regulating the evaporation of the solvent. According to embodiments, the thickness of the non-porous layer 211 can vary depending on the flow rate or velocity of the electrospinning solution to be spun, and can also vary depending on the moving speed of the collecting support 240. For example, the ratio of the thickness of the non-porous layer 211 to the thickness of the porous layer 213 can be from 1:1 to 1:19, preferably from 1:4 to 1:9.

[0088] After the non-porous layer 211 is formed to a predetermined thickness, the dissolution of the porous layer 213 by the solvent can be stopped when all the solvent spun onto the collection support 240 evaporates. Therefore, a waterproof sound-transmitting layer 210 comprising the non-porous layer 211 and the porous layer 213 disposed on the non-porous layer 211 can be formed. That is, the upper layer of the waterproof sound-transmitting layer 210 becomes the porous layer 213 with a mesh structure, and the lower layer of the waterproof sound-transmitting layer 210 is connected by fibers dissolved in the solvent, thus becoming the non-porous layer 211, with the pores in the mesh structure removed from the non-porous layer 211.

[0089] Since the waterproof sound-transmitting layer 210 according to the embodiments of the present disclosure includes a non-porous layer 211 disposed thereunder and a porous layer 213 disposed thereupon, the waterproof sound-transmitting sheet has a lighter weight and better elasticity compared to a waterproof sound-transmitting layer formed only of a non-porous layer, and is more effective in transmitting sound through vibration compared to a waterproof sound-transmitting layer formed only of a porous layer, and has further improved durability.

[0090] Figure 10 This is a cross-sectional view of a waterproof sound-transmitting layer according to an embodiment of the present disclosure. (Refer to...) Figure 10 The waterproof sound transmission layer 210 may include a non-porous layer 211 and a porous layer 213 disposed on the non-porous layer 211.

[0091] As described above, the porous layer 213 may include fibers 213a having a mesh structure formed of polymer material and beads 213b formed of polymer material and having a block shape.

[0092] During electrospinning, a non-porous layer 211 can be formed by blocking the pores 213c in the porous layer 213 when the porous layer 213 is dissolved by the solvent that is being entangled (or connected) with the polymer material during the spinning process.

[0093] Figure 11 This is a diagram showing the lower surface of a waterproof sound-transmitting layer according to an embodiment of the present disclosure. (Refer to...) Figure 11 The lower surface of the waterproof sound-transmitting layer 210, i.e. the lower surface of the non-porous layer 211, can be visible.

[0094] As described above, a non-porous layer 211 is formed by blocking the pores 213c in the porous layer 213 when the porous layer 213 is dissolved by the solvent processed together with the polymer material during electrospinning. Therefore, as Figure 11 As shown, the lower surface of the waterproof sound transmission layer 210 has no pores.

[0095] Figure 12 This is a flowchart illustrating a method for manufacturing a waterproof sound-transmitting layer according to an embodiment of the present disclosure. (Refer to...) Figure 12A collection bracket (S110) is provided. According to an embodiment, the collection bracket 240 may be a base on which a waterproof sound-transmitting layer 210 is laminated and transmitted through a collector 320.

[0096] An electrospinning solution comprising a polymer material and a solvent is provided (S120). According to an embodiment, the polymer material may include PDVF.

[0097] The electrospinning solution is electrospinned to form a porous layer (S130). According to an embodiment, when the electrospinning solution is electrospinned using a spinning nozzle 310, the polymer material is laminated onto the collection support 240 in the form of fibers to form a porous layer 213.

[0098] A non-porous layer 211 is formed by dissolving a portion of the porous layer 213 with a solvent (S140). According to the embodiment, the solvent that is spun together with the porous layer 213 during its formation is collected at the lower end of the porous layer 213, i.e., on the upper surface of the collection support 240, and the solvent dissolves the lower end of the porous layer 213, thus blocking the pores contained in the porous layer 213. Therefore, a portion of the porous layer 213 is formed as a non-porous layer 211.

[0099] After the non-porous layer 211 is formed, all the solvent remaining on the collection support 240 evaporates, thereby stopping the formation of the non-porous layer 211. The porous layer 213 is located on the upper layer, and the waterproof sound transmission layer 210, where the non-porous layer 211 is located, is formed on the lower layer.

[0100] Subsequently, the collection support is removed (S150). According to an embodiment, after the waterproof sound-transmitting layer 210 is separated from the collection support 240, the waterproof sound-transmitting layer 210 can be processed. This processing is to improve the operability of the waterproof sound-transmitting layer 210, and according to an embodiment, the waterproof sound-transmitting layer 210 is subjected to heat treatment, such as hot pressing or calendering, to fuse the fibers on the waterproof sound-transmitting layer 210. According to an embodiment, before heat treatment of the waterproof sound-transmitting layer 210, pre-drying can also be performed to evaporate the solvent remaining on the waterproof sound-transmitting layer 210.

[0101] Although preferred embodiments according to this disclosure have been described above, various changes may be made, and those skilled in the art can make various changes and modifications to the embodiments without departing from the scope of the claims of this disclosure.

[0102] [Industrial Applicability]

[0103] This invention relates to a waterproof sound-transmitting sheet and a method for manufacturing the waterproof sound-transmitting sheet.

Claims

1. A waterproof sound-transmitting sheet, characterized in that, include: A waterproof sound-transmitting layer that is waterproof and configured to transmit sound. A first adhesive layer is attached to the first surface of the waterproof sound-transmitting layer; as well as A second adhesive layer is attached to the second surface of the waterproof sound-transmitting layer located on the opposite side of the first surface, wherein... The waterproof sound-transmitting layer includes: Non-porous layers without pores; and A porous layer comprising pores is laminated on the non-porous layer. The porous layer has a mesh structure in which multiple fibers generated when an electrospinning solution containing polymer materials and solvent is electrospinned are laminated by interlacing with each other. The non-porous layer is formed by blocking the pores of the portion of the porous layer when the portion of the porous layer is dissolved by the solvent. The non-porous layer has the following structure: the plurality of fibers having the mesh structure are entangled, and the pores of the porous layer are blocked by the solvent. The porous layer includes: Fibers made of polymer materials; and Beads made of the polymer material and having a blocky shape, The beads are formed at both ends of the fiber. The ratio of the fibers to the beads in the porous layer is in the range of 3:7 to 7:

3. The ratio is the ratio of the area of ​​the fiber and the area of ​​the bead to the total area of ​​the porous layer, or the ratio of the weight of the fiber and the weight of the bead to the total weight of the porous layer.

2. The waterproof sound-transmitting sheet according to claim 1, characterized in that, The thickness of the non-porous layer is greater than or equal to the thickness of the porous layer.

3. A method for manufacturing a waterproof sound-transmitting sheet, characterized in that, include: Preparation of a collection scaffold; Preparation of spinning solutions containing polymer materials and solvents; A porous layer with a mesh structure is formed by electrospinning the spinning solution onto one surface of the collecting support, in which fibers are laminated by interlacing with each other; A non-porous layer is formed by dissolving a portion of the porous layer adjacent to one surface of the collection support using a solvent contained in the spinning solution. The porous layer is formed by laminating multiple fibers generated during electrospinning of the spinning solution to form a porous layer with a network structure through interlacing. The formation of the non-porous layer includes dissolving a portion of the porous layer with a solvent present in the lower part of the porous layer and allowing the plurality of fibers of the porous layer to entangle to block the pores of the porous layer. The porous layer comprises fibers made of the polymer material and laminated together by interlacing, and beads made of the polymer material having a blocky shape. The beads are formed at both ends of the fiber. The ratio of the fibers to the beads in the porous layer is in the range of 3:7 to 7:

3. The ratio is the ratio of the area of ​​the fiber and the area of ​​the bead to the total area of ​​the porous layer, or the ratio of the weight of the fiber and the weight of the bead to the total weight of the porous layer.

4. The method for manufacturing a waterproof sound-transmitting sheet according to claim 3, characterized in that, The surface of the collection bracket on which the porous layer is formed is coated with a non-porous waterproof membrane.

5. The method for manufacturing a waterproof sound-transmitting sheet according to claim 3, characterized in that, The collection holder is prepared by using at least one of release paper, art paper, coated paper, and glossy paper.

6. The method for manufacturing a waterproof sound-transmitting sheet according to claim 3, characterized in that, The preparation of the spinning solution includes preparing the spinning solution containing the polymer material, wherein the polymer material includes thermoplastic elastomer or PVDF.

7. The method for manufacturing a waterproof sound-transmitting sheet according to claim 3, characterized in that, The preparation of the spinning solution further includes preparing the spinning solution containing the polymer material, wherein the polymer material includes a thermoplastic elastomer and PVDF, and the weight ratio of the thermoplastic elastomer to the PVDF is 100:0 to 80:

20.

8. A waterproof sound-transmitting sheet, characterized in that, The waterproof sound-transmitting sheet is manufactured by any one of claims 3-7.

Images