Laminated sheet

Abstract

We provide a multi-functional laminated sheet with a multi-layer structure. [Solution] The laminated sheet 1 of the present invention comprises an upper layer 10 made of a nonwoven fabric having an anti-slip structure, a functional layer 30 made of thermoplastic polyurethane containing graphene powder, a lower layer 50 made of a nonwoven fabric having an anti-slip structure, a waterproof first adhesive layer 20 interposed between the upper layer and the functional layer, and a waterproof second adhesive layer 40 interposed between the functional layer and the lower layer, and is characterized by being configured symmetrically with respect to the thickness direction. In addition to anti-slip function, waterproofness, and mechanical strength, it can combine multiple functions such as thermal conductivity, antibacterial properties, and antistatic properties derived from graphene powder at a high level. Furthermore, by having a symmetrical structure centered on the functional layer, shrinkage differences caused by temperature and humidity changes are suppressed, the occurrence of warping and distortion can be reduced, and the same functions can be exhibited on both the front and back sides.

Description

Technical Field

[0001] The present invention relates to a laminated sheet having multifunctions with a multilayer structure.

Background Art

[0002] In various fields such as bedding, medical, nursing care, electronic devices, building materials, etc., various sheets having functions according to the applications are used. For example, in the field of bedding, a mattress cover or a sheet having waterproofness and moisture resistance is used. In the field of medical and nursing care, a waterproof sheet having antibacterial property and waterproofness is used. Further, in the field of electronic devices, a protective sheet having antistatic property and moisture resistance is used. These sheets are composed of materials such as thermoplastic resins (Patent Document 1) such as polyethylene and polypropylene, fiber materials (Patent Document 2) such as polyester and nylon, and rubber-based materials. Further, according to the application of the sheet, a structure in which a film, a nonwoven fabric, a foam, etc. are combined in a single layer or multiple layers is widely adopted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Many of the conventional sheets are designed to be specialized for specific functions, and it has been difficult to satisfy a plurality of functions simultaneously. For this reason, it has been necessary to use a plurality of sheets in combination according to the application, or to combine a plurality of materials, resulting in problems such as complication of the configuration, increase in cost, and deterioration of handleability.

Means for Solving the Problems

[0005] The laminated sheet of this invention comprises an upper layer made of a nonwoven fabric having an anti-slip structure, a functional layer made of thermoplastic polyurethane containing graphene powder, a lower layer made of a nonwoven fabric having an anti-slip structure, a waterproof first adhesive layer interposed between the upper layer and the functional layer, and a waterproof second adhesive layer interposed between the functional layer and the lower layer, and is characterized by being configured symmetrically with respect to the thickness direction. The laminated sheet of this invention may have a functional layer thickness within the range of 0.01 mm to 0.1 mm. The laminated sheet of this invention may have a weight ratio of graphene powder in the functional layer within the range of 3 w‰ to 5 w‰. The laminated sheet of this invention may have upper and lower layers with thicknesses ranging from 1 mm to 3 mm, respectively. The laminated sheet of this invention has a surface density of 100 g / m² for both the upper and lower layers. 2 ~200g / m 2 It may be within the range. The laminated sheet of this invention may have an upper layer and a lower layer made of needle-punched nonwoven fabric reinforced with needle punching. The laminated sheet of this invention may have an anti-slip structure consisting of anti-slip particles attached to the nap of a nonwoven fabric. The laminated sheet of this invention may have a first adhesive layer and a second adhesive layer made of a hot melt adhesive. The laminated sheet of this invention may have an overall thickness in the range of 2 mm to 6 mm. [Effects of the Invention]

[0006] The laminated sheet of this invention has a structure in which an upper layer and a lower layer made of a nonwoven fabric having an anti-slip structure, a functional layer made of thermoplastic polyurethane containing graphene powder, and a waterproof adhesive layer that integrates these are laminated symmetrically with respect to the thickness direction. This allows the single, thin-walled structure to possess multiple functions at a high level, including anti-slip properties, waterproofing, mechanical strength, as well as thermal conductivity, antibacterial properties, and antistatic properties derived from graphene powder. Therefore, there is no need to combine multiple sheets, resulting in superior handling and cost-effectiveness. Furthermore, by adopting a symmetrical structure centered on the functional layer, shrinkage differences caused by temperature and humidity changes are suppressed, reducing the occurrence of warping and distortion, and allowing the same functionality to be performed on both the front and back sides. [Brief explanation of the drawing]

[0007] [Figure 1] Diagram illustrating laminated sheets [Figure 2] Photo of the laminated sheet's appearance [Modes for carrying out the invention]

[0008] The laminated sheet of this invention will be described in detail below with reference to the drawings.

[0009] <1> Laminated sheet Laminated sheet 1 is a composite sheet that can be used for multiple applications. The laminated sheet 1 is formed by laminating an upper layer 10, a first adhesive layer 20, a functional layer 30, a second adhesive layer 40, and a lower layer 50 in that order (Figure 1). The laminated sheet 1 has a unique feature: its structure is symmetrical with respect to its thickness, centered around the functional layer 30. Specifically, the upper layer 10 and the lower layer 50 use materials with the same specifications (material, thickness, surface density, etc.), and the first adhesive layer 20 and the second adhesive layer 40 use adhesives with the same specifications, thereby ensuring that the balance of physical properties is the same on both the front and back surfaces. This helps to suppress warping and distortion caused by differences in shrinkage due to changes in temperature and humidity. Furthermore, since it performs equally well on both sides, there are no restrictions on orientation during use, making it highly convenient.

[0010] <1.1> Functions of Laminated Sheets The laminated sheet 1 of the present invention is a multi-functional sheet that has a plurality of functions such as heat conductivity, antibacterial property, and antistatic property derived from the graphene powder 31 of the functional layer 30 in addition to basic functions such as anti-slip function, waterproof property, and durability. Specifically, the anti-slip structure 11 provided in the upper layer 10 (lower layer 50) can exhibit a high frictional resistance with the installation surface and suppress displacement during use. In addition, the first adhesive layer 20 (second adhesive layer 40) having waterproof property integrates each layer, thereby ensuring high waterproof property and mechanical strength. Furthermore, the graphene powder 31 uniformly dispersed in the thermoplastic polyurethane 32 of the functional layer 30 improves the heat transfer efficiency and imparts antibacterial property and antistatic property.

[0011] <1.2> Applications of the laminated sheet Since the laminated sheet 1 of the present invention has multiple functions, it can be used for various applications. Specifically, for example, in the fields of bedding and furniture, it can be used for applications such as mattress covers and sheets that utilize waterproof property and antibacterial property. The laminated sheet 1 has high heat conductivity due to the graphene powder 31 and thus has an excellent temperature adjustment function. Therefore, for example, when the laminated sheet 1 is used as the fabric of a sheet, in summer, the heat of the body can be efficiently diffused to obtain a cooling effect, and in winter, the heat of an electric blanket or the like can be efficiently transmitted to the body. Also, in the fields of medical care and nursing care, it can be used for applications such as medical sheets and waterproof sheets for nursing care due to the suppression of displacement by the anti-slip function and durability. Furthermore, in the fields of electronic components and precision equipment, by utilizing the antistatic function and waterproof and moisture-proof functions, it can be used for applications such as packaging materials and protective sheets to protect electronic components and precision equipment from static electricity and moisture. In addition, by taking advantage of high mechanical strength and waterproof property, it can be used for various sheets and mats in the pet field, building materials field, outdoor field, etc. As described above, the laminated sheet 1 of the present invention can perform multiple functions with a single sheet, eliminating the need to combine multiple materials according to the application, and improving convenience and economy.

[0012] <2>Upper layer The upper layer 10 is a layer having a protective function and an anti-slip function of the functional layer 30. The upper layer 10 is made of a non-woven fabric having an anti-slip structure 11 formed on the surface side. In this embodiment, as the upper layer 10, a needle-punched non-woven fabric in which polypropylene short fibers are formed in a net shape and needle-punched reinforcement is performed about 1 to 3 times is adopted. The needle-punched non-woven fabric can exhibit high tensile strength and wear resistance because the short fibers are firmly intertwined by needle-punched reinforcement. The thickness of the upper layer 10 is preferably in the range of 1 mm to 3 mm, and more preferably about 2 mm. The areal density of the upper layer 10 is 2 ~200 g / m 2 preferably in the range of, and more preferably about 150 g / m 2 . However, the configuration of the upper layer 10 is not limited to the above. For example, the material of the non-woven fabric can be polyethylene, polyester, nylon, natural fiber, etc. Also, any thickness, areal density, etc. can be adopted.

[0013] <2.1>Anti-slip structure The anti-slip structure 11 is a structure that承担 the anti-slip function of the upper layer 10. In this embodiment, the anti-slip structure 11 is composed of anti-slip particles attached to the fuzz of the short fibers. The anti-slip particles are a resin that wraps the fuzz of the short fibers, and the particle size of each particle can be, for example, about 20 to 300 μm. The anti-slip particles are formed by preparing an anti-slip material containing a plasticizer, polyvinyl chloride, inorganic particles, etc. into a paste, spraying it in a mist onto the fuzz, and drying it. The anti-slip structure 11 of this embodiment exhibits high frictional resistance while a large number of minute anti-slip particles follow the deflection and minute displacement of the fuzz. However, the structure of the anti-slip structure 11 is not limited to the above, and may be a point plastic anti-slip, silicone anti-slip, PVC anti-slip, rubber anti-slip, etc.

[0014] <3> 1st adhesive layer The first adhesive layer 20 is a layer that integrally bonds the upper layer 10 and the functional layer 30. The first adhesive layer 20 consists of an adhesive that is interposed between the upper layer 10 and the functional layer 30 and solidifies them together. In this embodiment, a polyurethane-based hot-melt adhesive is used as the first adhesive layer 20. Polyurethane-based hot-melt adhesives offer excellent adhesion and flexibility, as well as waterproofing, thereby enhancing the overall waterproofing performance of the laminated sheet 1. This improves its applicability to applications in wet environments and medical settings. However, the composition of the first adhesive layer 20 is not limited to the above, and various hot-melt adhesives such as polyester-based, polyamide-based, or polyolefin-based adhesives, or water-based adhesives can be used, for example.

[0015] <4> Functional layer The functional layer 30 is a core layer that possesses various functions derived from graphene. The functional layer 30 consists of thermoplastic polyurethane (TPU) 32 containing graphene powder 31. Thermoplastic polyurethane 32 offers excellent waterproofing and elasticity, and by dispersing graphene powder 31 within the thermoplastic polyurethane 32, numerous functions such as antibacterial properties, anti-mite properties, antistatic properties, and high thermal conductivity can be added. The functional layer 30 can be manufactured by pre-mixing a polyol and a chain extender, adding graphene powder 31 and performing a dispersion treatment, then adding MDI (methylenediphenyl diisocyanate) and reacting it, followed by extrusion molding. The content of graphene powder 31 in the functional layer 30 is preferably in the range of 3 w‰ (per mille) to 5 w‰. The thickness of the functional layer 30 is preferably in the range of 0.01 mm to 0.1 mm. The weight of the functional layer 30 is preferably in the range of 3 w% to 12 w% of the total weight of the laminated sheet 1. However, the composition of the functional layer 30 is not limited to the above; any combination, thickness, etc., can be adopted.

[0016] <4.1> Graphene powder content In this embodiment, the content of graphene powder 31 in the functional layer 30 is set to within the range of 3w‰ to 5w‰. If the content of graphene powder 31 is less than 3 w‰, conductive paths and thermal conduction paths between the graphene powders 31 may not be sufficiently formed in the thermoplastic polyurethane 32, and there is a risk that functions such as antistatic properties and thermal conductivity cannot be sufficiently ensured. On the other hand, if the graphene powder content exceeds 5 w‰, the graphene powder 31 may aggregate, reducing its dispersibility, which may decrease the mechanical strength and flexibility of the functional layer 30, as well as worsen the fluidity during extrusion molding, making it difficult to form a uniform layer thickness. In response to the above, by setting the content of graphene powder 31 in the range of 3w‰ to 5w‰, it is possible to achieve both mechanical strength and flexibility and electrical and thermal conductivity of the functional layer 30.

[0017] <4.2> Thickness of the functional layer In this embodiment, the thickness of the functional layer 30 is set within the range of 0.01 mm to 0.1 mm. If the thickness of the functional layer 30 is less than 0.01 mm, it becomes difficult to ensure continuity as a layer, and variations in the dispersion state of the graphene powder 31 and localized defects are likely to occur. As a result, functions such as waterproofing, antistatic properties, and thermal conductivity may be impaired. On the other hand, if the thickness of the functional layer 30 exceeds 0.1 mm, the overall flexibility of the laminated sheet 1 decreases, impairing its bending conformability and making it more prone to stiffness. In addition, the increased thickness of the heat conduction path may reduce thermal conductivity. In contrast, by setting the thickness of the functional layer 30 within the range of 0.01 mm to 0.1 mm, it is possible to ensure functions such as thermal conductivity and antistatic properties without impairing the overall flexibility of the laminated sheet 1.

[0018] <5> 2nd adhesive layer The second adhesive layer 40 is a layer that adheres the functional layer 30 and the lower layer 50. The second adhesive layer 40 consists of an adhesive that has solidified between the functional layer 30 and the lower layer 50. The other components of the second adhesive layer 40 are the same as those of the first adhesive layer 20, so they are omitted from this description.

[0019] <6> lower layer The lower layer 50 is a layer that provides protection and anti-slip functions for the functional layer 30. The lower layer 50 consists of a nonwoven fabric with an anti-slip structure 51 formed on its surface side. The other components of the lower layer 50 are the same as those of the upper layer 10, so they are omitted here.

[0020] <7> Thickness of laminated sheet In this embodiment, the thickness of the laminated sheet 1 is set to a range of 2 mm to approximately 6 mm. If the thickness of the laminated sheet 1 is less than 2 mm, the thickness of the upper layer 10 and the lower layer 50 will be insufficient, making it difficult to ensure sufficient mechanical strength and wear resistance. In addition, the effect of the anti-slip structure 11 will be relatively weaker, and the displacement suppression function may be reduced. On the other hand, if the thickness of laminated sheet 1 exceeds 6 mm, the overall rigidity of the sheet increases, and its flexibility and bending conformability decrease. As a result, folding and rolling become difficult, and the flexibility required for applications such as sheets may be compromised. In response to the above, by setting the thickness of the laminated sheet 1 to a range of 2 mm to 6 mm, it is possible to achieve both mechanical strength and flexibility in a single laminated sheet 1. [Explanation of Symbols]

[0021] 1 Laminated sheet 10 upper layer 11. Anti-slip structure 20 1st adhesive layer 30 Functional Layers 31 Graphene powder 32 Thermoplastic Polyurethane 40 Second adhesive layer 50 lower layer 51 Anti-slip structure

Claims

1. An upper layer made of nonwoven fabric having an anti-slip structure, A functional layer made of thermoplastic polyurethane containing graphene powder, A lower layer made of nonwoven fabric having an anti-slip structure, A waterproof first adhesive layer interposed between the upper layer and the functional layer, The functional layer and the lower layer are interposed in a waterproof second adhesive layer, It is characterized by being configured symmetrically with respect to the thickness direction. Laminated sheet.

2. The thickness of the functional layer is characterized in to be within the range of 0.01 mm to 0.1 mm. The laminated sheet according to claim 1.

3. The weight ratio of the graphene powder in the functional layer is characterized in that it is within the range of 3 w‰ to 5 w‰. The laminated sheet according to claim 2.

4. The upper layer and the lower layer are characterized in that their thicknesses are within the range of 1 mm to 3 mm, respectively. The laminated sheet according to claim 3.

5. The surface density of the upper layer and the lower layer is 100 g / m², respectively. ２ ~200g / m ２ Characterized by being within the range The laminated sheet according to claim 4.

6. The upper layer and the lower layer are characterized in that they are needle-punched nonwoven fabrics reinforced with needle punching. The laminated sheet according to claim 5.

7. The anti-slip structure is characterized by comprising anti-slip particles attached to the nap of a nonwoven fabric. The laminated sheet according to claim 6.

8. The first adhesive layer and the second adhesive layer are characterized by being made of a hot melt adhesive. The laminated sheet according to claim 1.

9. It is characterized by having an overall thickness within the range of 2 mm to 6 mm. The laminated sheet according to claim 1.

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