Laminated sheet, method for producing the same, and insole including laminated sheet

Abstract

To provide a laminated sheet capable of securing adequate moisture absorbability and deodorizing performance even in a restricted size, while being easy to mold and long-lasting, and a method for producing the laminated sheet, and an insole employing the laminated sheet.SOLUTION: The present invention for solving the above-mentioned problem provides a laminated sheet X comprising a porous body retaining layer 1 and two ventilation layers 2 that sandwich the porous body retaining layer 1, the porous body retaining layer 1 being a mixture of an adhesive 12, which melts or softens upon heating and solidifies upon cooling, and a porous body 11 in powder form, the porous body retaining layer 1 being sandwiched and adhered between the ventilation layers 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an insole formed of a sheet-like laminate containing a porous material, which has excellent moisture absorption and deodorizing properties. [Background technology]

[0002] When people wear shoes, the inside of the shoes can easily become stuffy due to sweat, and that sweat can cause a strong odor. To address this issue, insoles with moisture-absorbing and deodorizing properties have been developed to keep the inside of shoes comfortable. These insoles are made of laminated materials containing porous materials, and are used in a wide range of applications, not just for shoes, but also for building interiors and other everyday items. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3668389 Summary of the Invention [Problem to be solved by the invention]

[0004] The laminate described in Patent Document 1 is composed of a porous material, primarily granular or powdered charcoal, bound together with a binder such as latex or emulsion, and sandwiched between coating layers to form a sheet, and has moisture absorption and deodorizing functions. However, the amount of moisture absorption and deodorization that charcoal can achieve is limited, making it unsuitable for continuous use in a small area such as a shoe insole.

[0005] In addition, the moisture absorption and deodorizing properties of such laminates also depend on the amount of porous material contained therein. For this reason, it is preferable to include a large amount of porous material in the layer, but in this case, the amount of binder increases, reducing the contact area with air necessary for the porous material to function, and there is also the problem that it is difficult to strengthen the adhesive strength between the upper and lower coating layers. In addition, from the perspective of adhesion to the coating layer, there is a method of applying an adhesive to the adhesive surface between the porous material layer and the coating layer, but since the porous material is exposed to air, it is not possible to apply the adhesive to the entire surface, and in this case too, there is a limit to the adhesive strength.

[0006] In view of the above problems, the present invention aims to provide a laminated sheet that ensures sufficient moisture absorption and deodorizing properties even in a limited size, is easy to mold, and lasts a long time, a method for manufacturing the same, and an insole using the laminated sheet. [Means for solving the problem]

[0007] The present invention, which solves the above-mentioned problems, is a laminated sheet comprising a porous body holding layer and two or more breathable layers sandwiching the porous body holding layer, wherein the porous body holding layer is a mixture containing an adhesive that melts or softens when heated and solidifies when cooled, and a powdered porous body, and is sandwiched and adhered between the breathable layers. With this configuration, sufficient moisture absorption and deodorizing properties can be ensured even with a limited size, and the molding is easy and the product can last a long time.

[0008] In a preferred embodiment of the present invention, an additional layer is laminated on the surface of at least one of the breathable layers facing the porous body holding layer. Such a configuration can protect the breathable layer and further improve the comfort of the laminated sheet.

[0009] In a preferred embodiment of the present invention, the adhesive contains at least one selected from the group consisting of a thermoplastic resin, a thermoplastic elastomer, and a viscoelastic resin. With this configuration, the porous body can be easily bonded and held by thermoforming.

[0010] In a preferred embodiment of the present invention, the adhesive is a polymer containing at least one monomer selected from the group consisting of vinyl acetate and olefinic hydrocarbons. With this configuration, the porous body holding layer and the breathable layer can be bonded easily and at low cost.

[0011] The present invention, which solves the above-mentioned problems, is an insole comprising a laminated sheet having a porous body holding layer and two breathable layers sandwiching the porous body holding layer, wherein the porous body holding layer is a mixture containing an adhesive that melts or softens when heated and solidifies when cooled, and a powdered porous body, and is sandwiched and adhered to the breathable layers. With this structure, the insole can be provided with sufficient moisture absorption and deodorizing properties, and can be easily molded and last a long time.

[0012] In a preferred embodiment of the present invention, additional layers are laminated on both sides of the breathable layer that face the porous body holding layer. This configuration protects the breathable layer and extends the life of the insole as a whole.

[0013] The present invention, which solves the above-mentioned problems, is a method for manufacturing a laminated sheet comprising a porous body holding layer and two breathable layers sandwiching the porous body holding layer, and includes a mixing step of mixing a powdered porous body with an adhesive that melts or softens when heated and solidifies when cooled to form a mixture, a clamping step of sandwiching the mixture between the breathable layers, and an adhering step of heating and cooling the mixture to adhere it to the breathable layers. With this configuration, it is possible to produce a laminated sheet that has sufficient moisture absorption and deodorizing properties even with a limited size, is easy to mold, and lasts a long time.

[0014] A preferred production method of the present invention further comprises a laminating step of laminating an additional layer on the surface of the breathable layer facing the porous body holding layer. Such a manufacturing method can protect the breathable layer and further improve the comfort of the laminated sheet.

[0015] In a preferred manufacturing method of the present invention, the adhesive comprises at least one selected from the group consisting of a thermoplastic resin, a thermoplastic elastomer, and a viscoelastic resin, and is in a powder form during the mixing step and is melted or softened by heating. By such a manufacturing method, the porous body can be easily bonded and held by thermoforming.

[0016] In a preferred production method of the present invention, the adhesive contains at least one selected from the group consisting of a thermoplastic resin, a thermoplastic elastomer, and a viscoelastic resin. By such a manufacturing method, the porous body can be easily bonded and held by thermoforming.

[0017] In a preferred production method of the present invention, the adhesive is a polymer containing at least one monomer selected from the group consisting of vinyl acetate and olefinic hydrocarbons. By using such a manufacturing method, the porous body holding layer and the breathable layer can be bonded easily at low cost.

[0018] The present invention, which solves the above-mentioned problems, is a method for manufacturing an insole that includes a laminated sheet having a porous body holding layer and two breathable layers sandwiching the porous body holding layer, and includes a mixing step of mixing a powdered porous body with an adhesive that melts or softens when heated and solidifies when cooled to form a mixture, a clamping step of sandwiching the mixture between the breathable layers, an adhering step of heating and cooling the mixture to adhere it to the breathable layers, and a cutting step of cutting the laminated sheet into a predetermined shape. By using such a manufacturing method, it is possible to obtain an insole that has sufficient moisture absorption and deodorizing properties, is easy to mold, and lasts a long time. [Effects of the Invention]

[0019] The present invention, which solves the above problems, aims to provide a laminated sheet that ensures sufficient moisture absorption and deodorizing properties even in a limited size, is easy to mold, and lasts a long time, a method for manufacturing the same, and an insole using the laminated sheet. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram illustrating a configuration of a laminate sheet according to an embodiment of the present invention. [Figure 2] 1A to 1C are schematic diagrams illustrating various states in a manufacturing process of a laminate sheet according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram showing the configuration of an insole using a laminated sheet according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, a laminate sheet X and an insole Y according to an embodiment of the present invention will be described with reference to the drawings. The description will be made in detail in the order of the configuration of the embodiment, the method of implementation, and other examples. The following embodiments are merely examples of the present invention, and the present invention is not limited to the following embodiments.

[0022] <Embodiment> As shown in Fig. 1(a), the laminate sheet X according to this embodiment comprises a porous body holding layer 1 and a breathable layer 2, with the porous body holding layer 1 sandwiched between two or more breathable layers 2, resulting in a laminated structure. Fig. 1(b) shows a configuration in which an additional layer 3 is further added to the laminate sheet X of Fig. 1(a). The presence or absence of the additional layer 3 is determined depending on the specifications and use of the laminate sheet X.

[0023] The porous body holding layer 1 comprises a powdered porous body 11 and an adhesive 12 that changes state (phase) in response to a thermal change, and the porous body 11 is held in a mixed state by mixing the two. In the state of the laminated sheet X shown in Figures 1(a) and 1(b), the adhesive 12 is solidified and the porous body holding layer 1 is sandwiched between the breathable layers 2, maintaining a sheet-like shape.

[0024] The porous body 11 is a powdery material in the form of particles with numerous irregularities, and the recesses contain and retain gases and liquids. In this embodiment, silica gel is most preferable as the porous body 11, which allows the laminated sheet X to be made particularly excellent in moisture absorption and deodorization. However, depending on the function required of the porous body 11, activated carbon, pumice, ceramics, etc. may be used, and the porous body holding layer 1 may be formed using one or more of these (a mixture of several of these is also possible). By using the porous body 11 as described above, the laminated sheet X can be dried in sunlight to restore its moisture absorption and deodorizing properties.

[0025] The adhesive 12 is a material that melts or softens when heated and solidifies when cooled, and in this embodiment holds the porous body 11 between the layers sandwiched between the breathable layers 2. In this embodiment, the adhesive 12 contains at least one type selected from the group consisting of thermoplastic resin, thermoplastic elastomer, and viscoelastic resin. Hot-melt adhesives such as EVA resin, synthetic rubber, polyamide, and polyester are more preferred, as they allow the porous body holding layer 1 to be easily formed by thermoforming.

[0026] The adhesive 12 is more preferably a polymer composed of an ester containing an olefin hydrocarbon (alkene) and / or vinyl alcohol among thermoplastic resins, and particularly preferably a polymer / copolymer containing vinyl acetate as a monomer. From the above, EVA (ethylene vinyl acetate) resin is the most preferable. This allows for a low-cost laminated sheet X that is harmless to humans.

[0027] The adhesive 12 is preferably in powder form when first mixed with the porous body 11. This makes it easier to mix the two, and also makes it easier to change the compounding ratio, increasing the proportion of the porous body 11 and improving moisture absorption and deodorizing properties. Furthermore, when the porous body 11 and the adhesive 12 are mixed as uniformly as possible, the adhesive 12 acts appropriately on each particle of the porous body 11, allowing the porous body 11 to be held more stably, and the adhesion to the breathable layer 2 becomes uniform, improving the adhesive strength. Furthermore, even if the laminated sheet X is cut at any location, the porous body 11 remains held within the porous body holding layer 1, making it easy to create a sheet shape according to the purpose.

[0028] 2(a), 2(b), and 2(c) are schematic diagrams showing the porous body holding layer 1 sandwiched between the breathable layers 2, and the various states in which the state inside the porous body holding layer 1 changes. Fig. 2(a) shows the state in which powdered porous body 11 and powdered adhesive 12 are mixed, Fig. 2(b) shows the state in which the adhesive 12 has melted or softened by heating, and Fig. 2(c) shows the state in which the adhesive 12 has solidified by cooling, and the porous body 11 has been fixed between the layers of the breathable layer 2.

[0029] In particular, as shown in FIG. 2(c), the adhesive 12 extends and solidifies in the direction bridging the two breathable layers 2, with the particles of porous body 11 adhered and held along the way, resulting in the laminated sheet X shown in FIG. 1(a). By appropriately setting the blending ratio of the porous body 11 and the adhesive 12 (e.g., the adhesive 12 is 50% or less by mass), the particles of porous body 11 are supported by the solidified adhesive 12 in the state shown in FIG. 2(c), while most of them are exposed. This configuration allows the particles of porous body 11 to easily come into contact with gas and moisture introduced into the porous body holding layer 1, enabling more efficient moisture absorption and deodorization. Furthermore, because there is nothing other than the adhesive 12 as a support that inhibits the function of the porous body 11, the porous body holding layer 1 contains a high proportion of porous body 11, and even if the layer thickness is limited, the laminated sheet X can have excellent moisture absorption and deodorization properties.

[0030] The breathable layer 2 is a sheet-like member with gaps through which gas can pass in the thickness direction. Two sheets sandwich the porous body support layer 1. The breathable layer 2 can be made of any material as long as it has numerous holes and gaps that allow air to pass through. However, a thin, moldable fiber aggregate, particularly a nonwoven fabric, spunbond fabric, or paper, is preferred. This allows gas to be appropriately introduced into the porous body support layer 1 from the outside of the laminated sheet X, fully utilizing the moisture absorption and deodorizing properties of the porous body 11. Furthermore, when the entire laminated sheet X is thermoformed while the adhesive 12 is melted or softened, the thickness in the stacking direction can be easily changed. Furthermore, the completed laminated sheet X can be cut into any shape and used. For example, the laminated sheet X can be cut (or molded) into a shape that matches the shape of a shoe sole, as shown in Figure 3, to form a shoe insole Y.

[0031] As shown in FIG. 1(b), the additional layer 3 is a sheet-like member laminated on the outer surface of the breathable layer 2 sandwiching the porous body holding layer 1, i.e., on the surface of the breathable layer 2 facing the porous body holding layer 1. The additional layer 3 is expected to be both a breathable layer with numerous holes and gaps that allow air to pass through, similar to the breathable layer 2, and a layer with high strength and anti-slip properties. The former is preferably made of, for example, a mesh fabric or a spunbond fabric, while the latter is preferably made of a rubber sheet, knit fabric, boa fabric, or the like. This allows gas to be appropriately introduced into the porous body holding layer 1 from the outside of the laminated sheet X through the breathable layer 2, making it possible to fully utilize the moisture absorption and deodorizing properties of the porous body 11.

[0032] The additional layer 3 is preferably made of a material different from the breathable layer 2, particularly a material that is more resistant to tearing or has a higher tensile strength than the breathable layer 2. This protects the breathable layer 2 and prevents the porous body holding layer 1 from being exposed and collapsing. Also, as in the case of the insole Y, the strength and durability of the entire laminated sheet X can be improved even when the surface comes into contact with the human body or the like. In the insole Y, the additional layer 3 may be made of a sweat-absorbent fabric, a deodorizing fabric, or a fabric with high heat retention (such as boa fabric).

[0033] As shown in FIG. 3(a), the insole Y includes a porous material holding layer 1, two breathable layers 2 sandwiching the porous material holding layer 1, and two additional layers 3 sandwiching the layers. The insole Y may have a substantially uniform thickness throughout, or, as shown in FIG. 3(b), the thickness may be varied to fit the shape of a person's foot. For example, the insole Y may be configured so that the arch is thicker than the surrounding area, or the amount of porous material 11 is increased only on the toe side, making the insole thicker overall. In particular, the latter configuration allows for more porous material 11 to be placed in the area of ​​the toes where sweating and odor are particularly severe when wearing shoes, allowing the insole Y to absorb moisture and deodorize more efficiently.

[0034] In Figures 1(b), 3(a), and 3(b), additional layers 3 are provided on both outermost surfaces of the laminate sheet X, but one of these layers may be changed to a non-breathable layer. Examples include a non-slip fabric (such as a rubber sheet), a material with excellent shock absorption (such as urethane or EVA foam), a material with excellent flexibility, or a material with high tensile strength (such as a knit fabric). This configuration makes it easier to install the laminate sheet X under usage conditions where only one side of the laminate sheet X is exposed to air.

[0035] Hereinafter, a method for manufacturing the laminated sheet X and the insole Y according to this embodiment will be described in detail with reference to the drawings. The manufacturing method described below is an example, and the manufacturing method is not limited to this, and the order of the steps may be reversed.

[0036] ≪Manufacturing method≫ In the manufacturing process of the laminated sheet X and the insole Y according to this embodiment, first, the laminated sheet X shown in FIG. 1(a) is manufactured, then the laminated sheet X shown in FIG. 1(b) is manufactured, and then the insole Y shown in FIG. 3 is manufactured.

[0037] <Mixing process> First, a mixture is prepared by mixing powdered porous body 11 and powdered adhesive 12, which will form porous body holding layer 1. As mentioned above, silica gel is most preferable for porous body 11, and a thermoplastic resin, particularly a hot-melt adhesive, is preferable for adhesive 12, with EVA being more preferable. By appropriately setting the blending ratio of porous body 11 and adhesive 12, this mixture can stably hold the particles of porous body 11 when laminate sheet X is completed, and can maintain good moisture absorption and deodorizing properties of porous body 11.

[0038] <Holding process> Next, the mixture is sandwiched between the breathable layers 2 to form the state shown in Fig. 2(a). In this state, the porous body holding layer 1 has not yet been formed, and particles of the porous body 11 and particles of the adhesive 12 are mixed between the two breathable layers 2.

[0039] <Adhesion process> Next, from the state shown in Fig. 2(a), the mixture is heated to melt or soften the adhesive 12. At this time, the adhesive 12 has viscosity and fluidity and adheres to the particles of the porous body 11 and the fibers of the breathable layer 2. This state is shown in Fig. 2(b). Thereafter, the mixture is cooled to completely solidify the adhesive 12. At this time, the adhesive 12 solidifies so as to connect the particles of the porous body 11 to each other or to the particles of the porous body 11 and the ventilation layer 2. In other words, as shown in FIG. 2(c), the particles of the porous body 11 are bonded and supported in the middle of the solid adhesive 12 that extends in the direction bridging the two ventilation layers 2. At this time, by appropriately setting the mixing ratio of adhesive 12 so that it is not excessive, as described above, the gaps between the linear adhesive 12 in the state shown in Figure 2(c) will be opened appropriately, and the surface area that the particles of porous body 11 can come into contact with air and moisture will be increased. Through the steps up to this point, the laminated sheet X shown in FIG. 1(a) is produced.

[0040] <Lamination process> In the laminate sheet X shown in Fig. 1(a), an additional layer 3 is laminated on the outer surface of the breathable layer 2, i.e., the surface of the breathable layer 2 facing the porous body retention layer 1. In particular, when this is performed on both of the two breathable layers 2, the laminate sheet X shown in Fig. 1(b) is produced. Furthermore, as described above, the additional layer 3 may be laminated on one of the two breathable layers 2, and a sheet material other than the additional layer 3, such as a non-breathable layer, may be laminated on the other. In particular, when manufacturing the insole Y, it is preferable that at least one of the additional layers 3 is made of a breathable material (mesh fabric, spunlace fabric, etc.), and that, if necessary, a shock-absorbing layer (urethane, EVA foam, etc.), an anti-slip layer (rubber sheet, etc.), or a high-strength layer (knit fabric, etc.) be laminated thereon.

[0041] <Cutting process> The laminated sheet X manufactured as described above is cut or punched into a predetermined shape (such as the shape of a shoe sole or a foot) to produce the insole Y. The insole Y may also include a step of varying the thickness in the lamination direction as shown in FIG. 3(b) by heat and pressure bonding when the adhesive 12 melts or softens. This allows the manufacture of insoles Y in a variety of shapes that are tailored to the shape of the sole of the user's foot, improving the comfort of use.

[0042] The laminate sheet X may have the following configuration and may be manufactured by the following manufacturing method corresponding to that configuration. However, the configurations shown below are merely examples, and whether or not they are included can be determined arbitrarily unless otherwise specified.

[0043] <Example of change> The porous body holding layer 1 may be a mixture of the porous body 11, the adhesive 12, and an aromatic agent. The porous body 11 may also be chemically treated to impart an aromatic property. With this configuration, the laminated sheet X can be used as an aromatic material.

[0044] The adhesive 12 may be a thermosetting resin, a photocurable resin, an ultraviolet curable adhesive, a moisture curable adhesive, an underwater curable adhesive, or the like, as long as it is in powder form when mixed with the porous body 11. This allows the laminated sheet X to be made in various forms depending on requirements such as strength, durability, and weather resistance.

[0045] In the case of the aforementioned adhesive 12, for example, a moisture-curing adhesive is manufactured by first mixing a powdered moisture-curing adhesive with a powdered porous body 11 (mixing process), sandwiching the mixture between the breathable layers 2 (sandwiching process), spraying water vapor onto the mixture to melt or soften the moisture-curing adhesive, and then drying and hardening it, thereby adhering the particles of the porous body 11 to the breathable layers 2 (adhesion process).

[0046] Two or more additional layers 3 may be laminated on the same side of the breathable layer 2 depending on the use and purpose of the laminate sheet X. With such a configuration, the feel of use of the laminate sheet X as a whole can be improved.

[0047] The insole Y may be a cup insole in which a resin layer made by thermoforming a thermosetting resin or the like is provided in place of the additional layer 3 on one side, and the peripheral edge of the other additional layer 3 is raised. With this configuration, the insole Y can be more stably placed on the user's foot, improving the comfort of use. [Explanation of symbols]

[0048] X laminated sheet Y insole 1 Porous material retention layer 11 Porous materials 12 Adhesive 2. Ventilation layer 3. Additive Layer

Claims

1. A laminated sheet comprising a porous body holding layer and two or more breathable layers sandwiching the porous body holding layer, The porous body holding layer is a mixture containing an adhesive that melts or softens when heated and solidifies when cooled, and a powdered porous body, and is sandwiched and adhered to the breathable layer.

2. an additional layer is laminated on the surface of at least one of the ventilation layers facing the porous body retention layer; The laminate sheet according to claim 1 .

3. The adhesive contains at least one selected from the group consisting of a thermoplastic resin, a thermoplastic elastomer, and a viscoelastic resin. The laminate sheet according to claim 1 .

4. The adhesive is a polymer containing at least one monomer selected from the group consisting of vinyl acetate and olefin hydrocarbons. The laminate sheet according to claim 1 .

5. An insole including a laminated sheet having a porous body holding layer and two breathable layers sandwiching the porous body holding layer, The porous body retaining layer is a mixture containing an adhesive that melts or softens when heated and solidifies when cooled, and a powdered porous body, and is sandwiched and adhered to the breathable layer.

6. A method for producing a laminated sheet comprising a porous body holding layer and two breathable layers sandwiching the porous body holding layer, a mixing step of mixing a powdery porous body with an adhesive that melts or softens when heated and solidifies when cooled to form a mixture; a sandwiching step of sandwiching the mixture between the breathable layers; and a bonding step of heating and cooling the mixture to bond it to the breathable layer.

7. The method further includes a lamination step of laminating an additional layer on the surface of the ventilation layer facing the porous body holding layer. The method of claim 6.

8. the adhesive contains at least one selected from the group consisting of a thermoplastic resin, a thermoplastic elastomer, and a viscoelastic resin, and is in a powder form in the mixing step and is melted or softened by the heating; The method of claim 6.

9. The adhesive is a polymer containing at least one monomer selected from the group consisting of vinyl acetate and olefin hydrocarbons. The method of claim 6.

10. A method for manufacturing an insole including a laminated sheet having a porous body holding layer and two breathable layers sandwiching the porous body holding layer, a mixing step of mixing a powdery porous body with an adhesive that melts or softens when heated and solidifies when cooled to form a mixture; a sandwiching step of sandwiching the mixture between the breathable layers; a bonding step in which the mixture is heated and cooled to bond it to the breathable layer; a cutting step of cutting the laminated sheet into a predetermined shape.

Images