KR102665786B1 - Breathable Waterproof Sheet and articles comprising the same - Google Patents

Abstract

A waterproof ventilated sheet is provided. The waterproof ventilation sheet according to an embodiment of the present invention includes a porous support member, a first fiber web disposed on the support member and containing nanofibers, and disposed between the support member and the first fiber web. It is implemented by providing a second fiber web containing heat-adhesive fibers that are fused to each other. According to this, the waterproof ventilation sheet has excellent water pressure resistance, uniform and high air permeability, and can be expanded to a large area, so it can be used in various electrical and electronic devices such as automobiles, medical, home appliances, mobile, office, and acoustics, as well as covering materials for clothing, shoes, and building materials, etc. It can be widely used in products across various industries.

Description

Waterproof breathable sheet and articles comprising the same {Breathable Waterproof Sheet and articles comprising the same}

The present invention relates to a waterproof ventilation sheet, and more specifically, to a waterproof ventilation sheet that has excellent water pressure resistance, uniform and high air permeability and can be expanded into a large area, and an article containing the same.

Automotive electrical components such as automotive head lamps, rear lamps, fog lamps, turn lamps, motors, various pressure sensors, and pressure switches, mobile devices such as cameras, camcorders, and mobile phones, office equipment, home appliances, and outdoor lighting Ventilation holes are often formed in various device housings, such as devices, medical devices, and audio devices such as microphones and speakers. The main purpose of forming the ventilation hole is to communicate between the inside and the outside of the device, thereby avoiding an excessive increase in internal pressure caused by a temperature rise within the device housing due to operation of the device. Additionally, ventilation holes are formed in the battery case for the purpose of discharging gases generated during battery operation.

However, in order to prevent water, dust, etc. from entering through the ventilation holes formed in the device housing for this purpose, a waterproof ventilation sheet may be placed in the ventilation holes.

Meanwhile, with the recent increase in the size of devices equipped with waterproof ventilated sheets, the demand for waterproof ventilated sheets that can exhibit high air permeability and water pressure resistance is increasing in consideration of the characteristics of the device along with the increase in the area of the waterproof ventilated sheet.

To this end, recently, a porous support to support the membrane, which performs the main function of a waterproof ventilation sheet, has been laminated to the membrane to strengthen its strength and to prevent deformation due to pressure.

When using a support, it is important to bond and integrate the membrane and the support. For example, there is a method of attaching the support and the membrane using an adhesive. This method changes the pore structure of the porous support and the membrane, blocks the pores, significantly reduces air permeability, or uses some adhesive depending on the material of the adhesive. There is a frequent problem that adhesive performance is greatly reduced in environments (extremely low temperature, high temperature, high pressure, and/or high humidity).

In addition, as another example, there is a method of directly thermally bonding the support and the membrane by imparting a thermal bonding function to the support itself. A support that can be used in this method is a heat-sealable nonwoven fabric. In order for the heat-sealable nonwoven fabric to have high mechanical strength, the diameter of the fibers forming the heat-sealable nonwoven fabric must inevitably become thicker, and in this case, the final laminated waterproofing material must be thicker. There is a problem with the thickness of the ventilation sheet becoming thicker.

In addition, there is a significantly large difference in thickness between the fibers that form the membrane and the fibers that form the heat-adhesive nonwoven fabric, and this difference in thickness has the problem of causing a deviation in the thickness of the membrane after the lamination process. When explaining with reference to Figure 1, when a waterproof ventilation sheet in which a membrane and a heat-sealable nonwoven fabric are laminated are observed from the membrane surface direction, the shape of the coarse-diameter fiber exposed on the surface of the heat-sealable nonwoven fabric has the same appearance as that transferred to the membrane. It can be observed. This phenomenon is due to the fibers exposed to the surface of the heat-adhesive nonwoven fabric compressing the membrane in the thickness direction due to the heat and pressure applied during lamination. As a result, the thickness of the membrane portion in contact with the exposed portion of the fibers on the surface of the heat-sealable nonwoven fabric becomes significantly thinner than the thickness of the membrane portion in contact with the pore portion without fibers, and the thinner membrane portion will be used as a waterproof and breathable sheet in the future. When used, it acts as a passage for moisture to flow in, reducing the water pressure of the waterproof ventilation sheet. In addition, the resulting difference in membrane thickness has the problem of significantly increasing the non-uniformity of air permeability.

Accordingly, there is an urgent need to develop a waterproof ventilation sheet that has excellent water pressure resistance, uniform and high air permeability, and can be expanded to a large area.

Republic of Korea Patent Publication No. 10-2013-0077756

The present invention was conceived in consideration of the above points, and its purpose is to provide a waterproof ventilation sheet that has excellent water pressure resistance, uniform and high air permeability, and can be expanded into a large area.

In addition, the present invention provides products that are covering materials for various electrical and electronic devices such as automobiles, medical, home appliances, mobile, office, and sound, or clothing/shoes, through the waterproof ventilation sheet according to the present invention, which has excellent water pressure resistance and high and uniform air permeability. There is another purpose in providing.

In order to solve the above-mentioned problem, the present invention provides a porous support member, a first fiber web disposed on the support member and containing nanofibers, and a first fiber web disposed between the support member and the first fiber web, respectively, and A waterproof, breathable sheet is provided having a second fiber web containing fused heat-sealable fibers.

According to one embodiment of the present invention, the waterproof ventilation sheet may filter moisture and foreign substances contained in the incoming air and allow the air to pass through.

Additionally, the first fiber web may include any one or more additives among water repellent, oil repellent, pigment, dye, functional additive, and moisture absorbent.

Additionally, the support member may have a thickness of 90 to 300 μm, the first fiber web may have a thickness of 3 to 40 μm, and the second fiber web may have a thickness of 5 to 50 μm.

In addition, the nanofibers include a fiber-forming ingredient containing a fluorine-based compound and any one or more additives among water repellent, oil repellent, and moisture absorbent, and the heat-adhesive fiber may include a polyester-based component with a melting point of 80 to 200°C. You can.

Additionally, the air permeability of the second fiber web may be 200 to 80 cfm, and the basis weight may be 3 to 20 g/m2.

Additionally, the average diameter of the heat-adhesive fibers may be 2 to 20 times the average diameter of the nanofibers.

In addition, the nanofibers may have an average diameter of 0.1 to 2㎛, and the heat-adhesive fibers may have an average diameter of 0.6 to 10㎛.

Additionally, the second fiber web may have an average pore diameter of 3 to 25 ㎛ and a porosity of 20 to 90%.

Additionally, the support member is a third fiber web including support fibers, and the average diameter of the support fibers may be 2 to 25 times the average diameter of the heat-sealable fibers.

Additionally, the present invention provides an article comprising the waterproof and breathable sheet according to the present invention.

According to one embodiment of the present invention, the goods may be electronic and electrical devices such as automotive electrical components, audio devices, medical devices, home appliances and office equipment, or parts thereof, or covering materials such as clothing, shoes, and building materials.

According to the present invention, the waterproof ventilation sheet has excellent water pressure resistance, uniform and high air permeability, and can be expanded to a large area, so it can be used for various electrical and electronic devices such as automobiles, medical, home appliances, mobile, office, and acoustics, as well as clothing, shoes, and building materials. It can be widely used in products across various industries, including covering materials.

1 is a photograph of the exterior surface of a waterproof ventilation sheet according to a comparative example of the present invention;
2 and 3 are cross-sectional views of a waterproof ventilation sheet according to an embodiment of the present invention;
Figure 4 is an SEM photograph of the second fiber web provided in the waterproof ventilation sheet according to an embodiment of the present invention, and
Figure 5 is a photograph of the exterior surface of a waterproof ventilation sheet according to an embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted, and identical or similar components are given the same reference numerals throughout the specification.

Referring to FIG. 2, the waterproof ventilation sheet 100 according to an embodiment of the present invention includes a porous support member 30, a material disposed on the support member 30 and containing nanofibers 10a. A first fiber web (10) and a second fiber web (20) including heat-adhesive fibers (20a) disposed between the support member (30) and the first fiber web (10) and fused to each of them. Equipped with The waterproof ventilation sheet 100 may be a filter that filters moisture and foreign substances contained in the incoming air and transmits the air. Specifically, air passes in both directions between the first fiber web 10 and the support member 30. All or part of the moisture and foreign matter contained in the air may be filtered through the first fiber web 10, and the air passing through the waterproof ventilation sheet 100 may not contain moisture.

The porous support member 30 is intended to ensure mechanical strength such as water pressure resistance and shape maintenance of the waterproof ventilation sheet 100, and may be a known porous member used in the filter field. For example, the support member 30 Can be non-woven, woven or knitted.

The above fabric means that the fibers included in the fabric have longitudinal and horizontal directions, and the specific structure may be plain weave, twill weave, etc., and the density of the warp and weft threads is not particularly limited. In addition, the knitted fabric may be a known knit structure, weft knitted fabric, warp knitted fabric, etc., and for example, it may be tricot in which the yarn is warp knitted. Alternatively, the support member 30 may be a nonwoven fabric with no longitudinal or horizontal direction in the fibers, and may be dry nonwoven fabric such as chemical bonded nonwoven fabric, thermal bonded nonwoven fabric, airlay nonwoven fabric, wet nonwoven fabric, spanless nonwoven fabric, needle punched nonwoven fabric, or melt blown fabric. Known nonwoven fabrics manufactured by various methods such as the same can be used.

There is no limitation as to the material of the support member 30 as long as it is a known material used in the filter field. Non-limiting examples thereof include synthetic polymer components selected from the group consisting of polyester-based, polyurethane-based, polyolefin-based, and polyamide-based; Alternatively, a natural polymer component including cellulose may be used, and for example, it may be formed of a polyester-based synthetic polymer component, specifically polyethylene terephthalate (PET). Additionally, the support member 30 may contain a low melting point polymer component to increase adhesion to the second fiber web 20, which will be described later. That is, if the support member 30 is made of a fabric such as non-woven fabric, it may be manufactured with all or part of fibers containing a low-melting point polymer component.

In addition, the support member 30 may include a water repellent, an oil repellent, a moisture absorbent, etc. that may be included in the first fibrous web 10, which will be described later, in order to further reduce the permeability of moisture.

Meanwhile, the support member 30 may have a thickness of 90 to 300 μm in order to exhibit mechanical strength such as sufficient water pressure resistance and shape maintenance. Additionally, the support member 30 may have a basis weight of 15 to 90 g/m2. If the basis weight is less than 15g/m2, it may be difficult to develop sufficient mechanical strength. If the basis weight exceeds 90g/㎡, there is a risk that a sufficient flow path may not be formed, resulting in a decrease in flow rate and an increase in differential pressure.

In addition, the support member 30 may be a third fiber web including support fibers, and the average diameter of the support fibers is equal to the average diameter of the heat-adhesive fibers 20a included in the second fiber web 20, which will be described later. It can be 2 to 25 times. In this case, considering the diameter of the fibers constituting the second fiber web 20, which will be described later, the contact area increases when the support member 30 and the second fiber web 20 are joined, and an increased adhesion force is expressed through this. It has the advantage of achieving the desired mechanical strength at the same time. For example, the average diameter of the support fibers may be 15 to 35㎛. Additionally, the support member 30 may have an average pore diameter of 10 to 70 ㎛ and a porosity of 20 to 90%.

Next, the second fiber web 20 will be described. The second fiber web 20 serves the function of adhesion between the support member 30 described above and the first fiber web 10 described later. For this purpose, the second fiber web 20 may be formed by including all or part of the heat-adhesive fibers 20a, for example, it may be formed by including all of them.

The second fiber web 20 is designed to address problems that arise when the support member 30, which is implemented to have sufficient mechanical strength, and the first fiber web 10 are directly joined, for example, each of the first fiber webs and the support member forming the first fiber web 20 has sufficient mechanical strength. It is provided to prevent the problem of thickness deviation of the first fiber web, lowered water pressure resistance, uneven ventilation, etc. caused by diameter differences between fibers, and despite the use of the support member 30 implemented to have sufficient mechanical strength, the target It plays a role in providing water pressure resistance and breathability.

The heat-adhesive fiber 20a is usually called hot melting fiber, low melting point yarn (or low melting point fiber) or LM (Low Melting) yarn, and non-melting point yarn (or non-melting point fiber) with no melting point and no softening point. It may be any known fiber. For example, the heat-adhesive fiber 20a may be a fiber containing a polyester-based heat-adhesive component. Polyester-based heat-adhesive components are manufactured to lower the melting point by modifying one or more of the polyvalent carboxylic acids and diols that make up polyester, or to eliminate the melting point and have only a softening point. For example, the melting point is 80 to 200°C, It may have no melting point and a softening point of 80 to 150°C. For example, the heat-adhesive component may be modified by substituting a portion of terephthalic acid as an aromatic component among the polyhydric carboxylic acids with isophthalic acid, and/or substituting a portion of terephthalic acid with an aliphatic polyhydric carboxylic acid such as adipic acid. In addition, as a diol, a part of ethylene glycol can be used as an aliphatic diol, such as 1,4-butanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5- It may be modified by substitution with an aliphatic diol with a side chain such as pentanediol, but is not limited to this.

The heat-adhesive fiber 20a may be a composite fiber formed so that at least a portion of the heat-adhesive component described above is exposed to the external surface, or a fiber formed only of the heat-adhesive component described above. If it is in the form of a composite fiber, it may further include a support component in addition to the heat-adhesive component. As an example of a cross-sectional structure, the support component forms a core portion, and the heat-adhesive component forms a sheath portion surrounding the core portion. It may be a composite fiber or a side-by-side composite fiber in which a heat-adhesive component is disposed on one side of the support component.

The heat-adhesive fibers (20a) may have an average diameter of 0.6 to 10㎛, which is advantageous for improving the adhesion with the first fiber web (10), which will be described later, and the first fiber web (10) generated in the lamination process. ) can minimize or prevent thickness variations.

Since the heat-adhesive fiber 20a has a lower melting point than the components forming the first fiber web 10 and the support member 30, the surface in contact with the first fiber web 10 as shown in FIG. 3 The heat-adhesive fibers located on the side form a fusion portion (P) with the first fiber web 10, and the heat-adhesive fibers located on the surface in contact with the support member 30 form a fusion portion (P) with the support member 30. By forming P), the support member 30, which is implemented to have high mechanical strength, and the first fiber web 10 can be easily attached.

The second fiber web 20 formed including the above-described heat-adhesive fiber 20a may be a non-woven fabric manufactured through a conventional method, and there is no limitation to the manufacturing method such as melt blown, needle punching, or wet-laid non-woven fabric. . In addition, the second fiber web 20 may have a thickness of 5 to 50 ㎛, and if the thickness is less than 5 ㎛, it may be difficult to ensure sufficient bonding strength, handling may be difficult, and uniformity may be reduced due to deformation due to tension. there is. Additionally, if the thickness exceeds 50㎛, the manufacturing cost increases, the filter thickness becomes thick, and thickness control may be difficult.

In addition, to ensure stronger adhesion and not impede the breathability of the waterproof ventilation sheet, the air permeability of the second fiber web 20 may be 200 to 800 cfm, and the basis weight may be 3 to 20 g/m2. Additionally, the second fiber web 20 may have an average pore diameter of 3 to 25 ㎛ and a porosity of 20 to 90%.

Next, the first fiber web 10 is formed including nanofibers 10a and may have a three-dimensional network structure.

The first fibrous web 10 can be used without limitation in the case of a known filter having the characteristics of a waterproof ventilation sheet, that is, a material that can filter moisture and foreign substances contained in the incoming air and allow air to pass through, and an internal structure. there is.

The nanofibers 10a may be included in whole or in part in the first fiber web 10. For example, the first fiber web 10 may be formed only with the nanofibers 10a.

The nanofiber 10a may be a polymer compound whose fiber-forming component has hydrophobic properties in order to prevent moisture in the air from passing through, and for example, may be a fluorine-based polymer compound. Specifically, the fluorine-based polymer compounds are polytetrafluoroethylene (PTFE)-based, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)-based, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP)-based. , tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE) system, tetrafluoroethylene-ethylene copolymer (ETFE) system, polychlorotrifluoroethylene (PCTFE) system, chlorotri It may include one or more compounds selected from the group consisting of fluoroethylene-ethylene copolymer (ECTFE) and polyvinylidene fluoride (PVDF). However, considering that the fiber-forming component of the nanofiber 10a may reduce moisture permeability by additives described later, some or all of the fiber-forming component may not be a fluorine-based compound. In this case, the fiber-forming ingredient that can be used can be any material known to be suitable for producing nanofibers without limitation, and non-limiting examples include polyethylene glycol including polyethylene glycol dialkyl ether and polyethylene glycol dialkyl ester. Derivatives, poly(oxymethylene-oligo-oxyethylene), polyoxides including polyethylene oxide and polypropylene oxide, polyvinylacetate, poly(vinylpyrrolidone-vinylacetate), polystyrene and polystyrene acrylonitrile copolymer, poly It may be acrylonitrile (PAN), polyacrylonitrile copolymer including polyacrylonitrile methyl methacrylate copolymer, polymethyl methacrylate, polymethyl methacrylate copolymer, or a mixture thereof.

Meanwhile, the nanofiber 10a may contain one or more additives among water repellent, oil repellent, and moisture absorbent to reduce moisture permeability. The additives are mixed with fiber-forming ingredients when manufacturing nanofibers (10a) and are provided on the nanofibers (10a), or these additives are added to the outer surface or the outer surface and inner surface of a fiber web manufactured including nanofibers. It may be provided after being processed, and in this case, the treatment may be a typical coating method, so detailed description thereof will be omitted.

At this time, the water repellent agent is not particularly limited, but may include silicone resin, fluorine resin, paraffin wax, or alkylketene dimer. In particular, fluorine-based water repellent agents can provide not only water repellency but also oil repellency, so they are very advantageous in providing higher water repellency or oil repellency.

The oil repellent may be a fluorine-based or silicone-based component, but is not limited thereto.

The hygroscopic agent may be a known ingredient capable of removing moisture or moisture, and examples include metal powders such as alumina, metal oxides, metal salts, or moisture-reactive hygroscopic agents such as phosphorus pentoxide (P2O5), silica, zeolite, titania, and zirconia. Alternatively, it may be a physical moisture absorbent such as montmorillonite.

Meanwhile, the additive may include functional additives such as pigments, dyes, and/or UV blockers and ionic substances. The specific types of these additives can be used without limitation in the case of components commonly used in the filter field, so the present invention does not specifically limit them.

Additionally, the nanofibers 10a may have an average diameter of 0.1 to 2㎛. However, in order to increase adhesion to the above-described second fiber web 20 and increase water pressure resistance, the average diameter of the heat-adhesive fibers 20a is more preferably 2 to 20 times the average diameter of the nanofibers 10a. In other words, the diameters of the nanofibers 10a and the heat-adhesive fibers 20a may be adjusted to be 5 to 10 times larger. If the diameter of the heat-adhesive fiber is less than twice the diameter of the nanofiber, air permeability may be reduced due to excessive adhesion to the nanofiber. In addition, if the diameter of the heat-adhesive fiber exceeds 20 times the diameter of the nanofiber, thickness deviation of the first fiber web 10 may occur after the lamination process, which may lead to a decrease in moisture removal ability and non-uniformity in breathability. .

The first fiber web 10 may have a thickness of 3 to 40 ㎛ depending on the required water resistance. Additionally, the first fibrous web 10 may have a pore diameter of 5 μm or less and a porosity of 20 to 90%.

The first fibrous web 10 may have a wetting angle of 110° or more on the surface that the incoming air first contacts, and this may prevent the passage of moisture flowing in through it and make it easy to remove it.

The waterproof ventilation sheet 100 described above may be manufactured by a manufacturing method described later, but is not limited thereto.

The waterproof ventilation sheet 100 has a support member 30 disposed on one side of the second fiber web 20, and a first fiber web 10 is disposed on the other side opposite to the second fiber web 20. It can be manufactured by combining them by applying heat and/or pressure.

Alternatively, the support member 30 is placed on one side of the second fiber web 20 and a lamination process is performed by applying heat and/or pressure, and then a first layer is placed on the other side opposite to one side of the second fiber web 20. It may also be manufactured by performing a post-lamination process in which the fiber web 10 is placed and then laminated by applying heat and/or pressure. At this time, it should be noted that the order of the pre-lamination process and the post-lamination process can be changed to laminate the second fiber web 20 and the first fiber web 10 first.

The heat applied in the lamination process may have a temperature of 100 to 150°C. Additionally, the pressure may be 2 to 6 kgf/m2, but is not limited thereto, and may be adjusted appropriately taking into account the thermal properties of the second fiber web and the first fiber web.

The above-described waterproof ventilation sheet 100 can be used for air vents or acoustic purposes, and can implement various related items related to the corresponding uses. For example, waterproof ventilation sheets for air vents can be applied to various technical fields such as vehicles, electrical and electronics, outdoor billboards, repeaters, covering materials, and medical care. In addition, the waterproof ventilation sheet for acoustics emits sound to the outside, prevents liquids or foreign substances from penetrating from the outside to the inside, and can implement acoustic devices such as speakers and microphones.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in the present specification, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , other embodiments can be easily proposed by change, deletion, addition, etc., but this will also be said to be within the scope of the present invention.

10: first fiber web 20: second fiber web
30: Support member 100: Waterproof ventilation sheet

Claims (11)

Porous support member;
A first fiber web disposed on the support member and including nanofibers with an average diameter of 0.1 to 2㎛; and
A second fiber web including heat-adhesive fibers having an average diameter of 0.6 to 10 ㎛ disposed between the support member and the first fiber web and fused to each of them, wherein the average diameter of the heat-adhesive fibers is is a waterproof and breathable sheet that is 2 to 20 times the average diameter of the nanofibers. According to paragraph 1,
The waterproof ventilation sheet is a waterproof ventilation sheet, characterized in that it filters moisture and foreign substances contained in the incoming air and allows air to pass through. According to paragraph 1,
The first fiber web is a waterproof breathable sheet characterized in that it contains one or more additives among water repellent, oil repellent, pigment, dye, functional additive, and moisture absorbent. According to paragraph 1,
A waterproof ventilation sheet, characterized in that the thickness of the support member is 90 to 300 ㎛, the thickness of the first fiber web is 3 to 40 ㎛, and the thickness of the second fiber web is 5 to 50 ㎛. According to paragraph 1,
The nanofibers contain a fiber-forming ingredient including a fluorine-based compound and any one or more additives among water repellent, oil repellent, and moisture absorbent,
A waterproof breathable sheet, characterized in that the heat-adhesive fiber contains a polyester-based component with a melting point of 80 to 200°C. According to paragraph 1,
A waterproof breathable sheet, characterized in that the air permeability of the second fiber web is 200 to 800 cfm and the basis weight is 3 to 20 g/m2. delete delete According to paragraph 1,
The second fiber web is a waterproof and breathable sheet, characterized in that the average pore diameter is 3 to 25㎛ and the porosity is 20 to 90%. According to paragraph 1,
The support member is a third fiber web containing support fibers,
A waterproof breathable sheet, characterized in that the average diameter of the support fibers is 2 to 25 times the average diameter of the heat-sealable fibers. An article comprising the waterproof and breathable sheet according to any one of claims 1 to 6, 9, and 10.

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