film sheet

Abstract

To provide a film sheet with high water pressure resistance and excellent waterproofing. [Solution] The film sheet 2 of the present invention contains a thermoplastic resin other than an acrylic polymer and a plurality of inorganic particles. The thermoplastic resin has a fibrous portion 7 and a non-fibrous portion 8. Of the plurality of inorganic particles, exposed inorganic particles having a portion exposed from the thermoplastic resin are present at the periphery of a plurality of void portions 5 where the thermoplastic resin is absent. The inorganic particles have a function, and in the observation field of view when the surface of the film sheet 2 is magnified 5000 times with a scanning electron microscope, the resin occupancy rate, which is the ratio of the total area of ​​the thermoplastic resin to the area of ​​the observation field, may be greater than 0% and less than or equal to 80%.

Description

[Technical Field]

[0001] This invention relates to a porous film sheet containing inorganic particles. [Background technology]

[0002] Patent Document 1 describes a film that is waterproof and breathable and useful as a material for clothing, comprising a porous polyethylene membrane with a porosity of 60% or more and a hydrophilic polymer filling at least a portion of the pores of the porous polyethylene membrane, wherein the water vapor transmission rate is within a specific range. The porosity is described in section

[0074] of Patent Document 1. Patent Document 1 also states that inorganic pigments or dyes may be used for the purpose of coloring the porous polyethylene and / or the hydrophilic polymer. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Special Publication No. 2021-532287 [Overview of the project] [Problems that the invention aims to solve]

[0004] Porous film sheets containing inorganic particles can become functional film sheets with specific functions by using inorganic particles that have specific functions (e.g., deodorizing function). Combined with the high breathability resulting from the porous structure, this opens up possibilities for various applications.

[0005] The aforementioned film sheets are typically required to have high breathability as well as high water pressure resistance. Film sheets with low water pressure resistance may lose their waterproof properties over time, potentially rendering them unsuitable for practical use.

[0006] The object of the present invention is to provide a film sheet with high water pressure resistance and excellent waterproofing properties. [Means for solving the problem]

[0007] The present invention relates to a film sheet containing a thermoplastic resin other than an acrylic polymer and a plurality of inorganic particles. In one embodiment of the film sheet of the present invention, the thermoplastic resin has a fibrous portion and a non-fibrous portion. In one embodiment of the film sheet of the present invention, exposed inorganic particles, among the plurality of inorganic particles, which have a portion exposed from the thermoplastic resin, are present at the periphery of a plurality of voids where the thermoplastic resin is absent.

[0008] Furthermore, the present invention relates to a wearable article that includes a film sheet. In one embodiment of the wearable article of the present invention, the film sheet comprises a thermoplastic resin and a plurality of inorganic particles. In one embodiment of the wearable article of the present invention, the film sheet has a plurality of voids in which the thermoplastic resin is absent, extending through the thermoplastic resin. In one embodiment of the wearable article of the present invention, exposed inorganic particles, which have a portion exposed from the thermoplastic resin, are present at the periphery of the plurality of voids. In one embodiment of the wearable article of the present invention, the wearable article is selected from the group consisting of clothing, shoes, hats, and articles used to absorb bodily fluids discharged from the human body.

[0009] Furthermore, the present invention contains thermoplastic resins other than acrylic polymers and a plurality of inorganic particles, The thermoplastic resin has a fibrous portion and a non-fibrous portion, A method for manufacturing a film sheet, wherein exposed inorganic particles, among the plurality of inorganic particles, which have a portion exposed from the thermoplastic resin, are present at the periphery of a plurality of voids where the thermoplastic resin is absent, A process (stretching process) of performing first stretching in one direction is carried out on an unstretched sheet containing a thermoplastic resin other than an acrylic-based polymer and a plurality of inorganic particles. In one embodiment of the method for manufacturing the film sheet of the present invention, after performing the stretching process, there is a process of performing second stretching in a direction intersecting the one direction. Other features, effects and embodiments of the present invention will be described below.

Effects of the Invention

[0010] According to the present invention, a film sheet with high water pressure resistance and excellent waterproofness is provided.

Brief Description of the Drawings

[0011] [Figure 1] FIG. 1 is a photograph substituting for a drawing corresponding to a 5000-fold observation field of the surface of one embodiment of the film sheet of the present invention. [Figure 2] FIG. 2 is a photograph substituting for a drawing corresponding to a 5000-fold observation field of the surface of another embodiment (the film sheet of Example 1) of the film sheet of the present invention. [Figure 3] FIG. 3 is a photograph substituting for a drawing corresponding to a 5000-fold observation field of the surface of still another embodiment of the film sheet of the present invention. [Figure 4] FIG. 4 is a schematic plan view of a 5000-fold observation field of the surface of one embodiment of the film sheet of the present invention. [Figure 5] FIG. 5 is a photograph substituting for a drawing obtained by imaging a cross section along the thickness direction of the film sheet shown in FIG. 2 with SEM. [Figure 6] FIG. 6 is an explanatory diagram of a method for measuring the degree of orientation of fibrous portions in the film sheet. [Figure 7] FIG. 7 is a photograph substituting for a drawing corresponding to a 5000-fold observation field of the surface of the film sheet of Example 2. [Figure 8] FIG. 8 is a photograph substituting for a drawing corresponding to a 5000-fold observation field of the surface of the film sheet of Example 3. [Figure 9]Figure 9 is a photograph used as a substitute for a drawing, corresponding to the 5000x observation field of view of the surface of the film sheet of Example 4. [Figure 10] Figure 10 is a photographic representation of the drawing, corresponding to the 5000x observation field of view of the surface of the film sheet of Example 18. [Modes for carrying out the invention]

[0012] The film sheet of the present invention contains a thermoplastic resin and a plurality of inorganic particles. The thermoplastic resin constitutes the main body of the film sheet of the present invention. Preferably, the thermoplastic resin forms a network structure including fibrous portions and / or non-fibrous portions, as described later, and forms the basic structure of the film sheet. The inorganic particles are used to form voids in the film sheet of the present invention, as described later, and may also be used to impart specific functions to the film sheet.

[0013] Figures 1-3 show the observation field (hereinafter also referred to as the "5000x observation field") obtained by scanning electron microscope (SEM) at 5000x magnification of the surface of one embodiment of the film sheet of the present invention (film sheets 1-3). Here, "the surface of the film sheet" refers to one of a pair of opposing surfaces (main surfaces) located at both ends in the thickness direction of the film sheet. Unless otherwise specified, the "surface of the film sheet" includes both surfaces of the pair of surfaces of the film sheet.

[0014] In the film sheet of the present invention, it is preferable that the thermoplastic resin extends around and encloses a plurality of voids where the thermoplastic resin is not present. In such a preferred form of film sheet, the voids are scattered, making it porous and breathable. In the film sheet of the present invention, typically, multiple voids formed by being surrounded by a thermoplastic resin exist on the surface and inside the film sheet. Furthermore, it is preferable that at least some of these multiple voids communicate with each other by overlapping in the thickness direction of the film sheet (in the illustrated example, the direction perpendicular to the plane of the paper), forming a void with a larger volume. The voids are typically not closed, i.e., not completely surrounded by the thermoplastic resin. It is preferable that the voids consist of voids between multiple adjacent fibrous portions. Specific examples of this are shown in Figures 1 to 3.

[0015] It is preferable that the inorganic particles contained in the film sheet include inorganic particles having portions exposed from the thermoplastic resin (hereinafter also referred to as "exposed inorganic particles"). The inorganic particles contained in the film sheet may also include inorganic particles whose entire surface is covered with thermoplastic resin and have no exposed portions (hereinafter also referred to as "non-exposed inorganic particles"). In the 5000x observation field shown in Figures 1-3, the white dots represent inorganic particles. Among the multiple white dots in the 5000x observation field, those with a relatively darker white color are exposed inorganic particles, while those with a relatively lighter white color are non-exposed inorganic particles.

[0016] Whether inorganic particles contained in a film sheet are exposed inorganic particles can be determined by performing elemental analysis of the inorganic particles. Typically, if the elemental analysis reveals that the inorganic particles contain metal, or substantially no thermoplastic resin (carbon), then the inorganic particles are determined to be exposed inorganic particles. Furthermore, if the elemental analysis reveals that the inorganic particles substantially contain no metal, or substantially only thermoplastic resin (carbon), then the inorganic particles are determined to have no portion exposed from the thermoplastic resin. The elemental analysis can be performed using known analytical means in accordance with conventional methods. An example of such analytical means is a scanning electron microscope (SEM) with an energy-dispersive X-ray analyzer (EDS).

[0017] It is preferable that exposed inorganic particles are present at the periphery of the void portion 5. The "periphery of the void portion 5" refers to the area within 1 μm outside the void portion 5 from the periphery (outline of the void portion 5) in a 5000x observation field. In the 5000x observation field of the surface of one embodiment of the film sheet of the present invention shown in Figure 4, the portion indicated by reference numeral 5S is the periphery of the void portion 5. Note that Figure 4 schematically shows only the outermost surface of the film sheet for ease of explanation and differs from an actual film sheet.

[0018] Porous film sheets containing a thermoplastic resin and multiple inorganic particles are typically manufactured by stretching an unstretched sheet containing the thermoplastic resin and multiple inorganic particles. This stretching process causes interfacial delamination between the thermoplastic resin and the inorganic particles. As a result, multiple voids are formed on the surface and inside the thermoplastic resin where the thermoplastic resin is absent. Consequently, the thermoplastic resin becomes porous. Conventional porous film sheets manufactured in this way, i.e., film sheets having multiple voids, generally have low water pressure resistance, and there was room for improvement in waterproofing. As a result of various studies to solve this problem, the inventors of the present invention found that porous film sheets in which exposed inorganic particles exist at the periphery of the voids have higher water pressure resistance and superior waterproofing compared to those in which exposed inorganic particles do not exist at the periphery of the voids. The film sheet of the present invention is based on this finding.

[0019] The reason why the water pressure resistance of the film sheet is higher when exposed inorganic particles are present at the periphery of the voids compared to when they are absent is unclear. However, it is presumed that the former tends to result in a smaller span of the voids. In other words, to improve the water pressure resistance (waterproofing) of the porous film sheet, it is effective to reduce the span of the multiple holes, i.e., voids, that the film sheet has (Reference: Masaru Haruta, "Nano-functional controlled membrane waterproof and breathable material 'Entrant'", Journal of the Textile Machinery Society of Japan, Vol. 59, No. 3, 2006, pp. 173-176, pp. 27-30). Furthermore, the voids with exposed inorganic particles at the periphery are formed in the stretching process by interfacial isolation of the thermoplastic resin near the surface of the exposed inorganic particles. Compared to those formed by interfacial isolation of the thermoplastic resin near the surface of non-exposed inorganic particles, these tend to have a smaller span and a larger number of voids. On the other hand, among the porous film sheets, those without exposed inorganic particles at the periphery of the voids are less likely to have voids formed during the stretching process. This is thought to be because the interface is such that interfacial delamination between the particles and the resin is less likely to occur. Furthermore, even if voids are formed, their span tends to be large, which tends to reduce water pressure resistance. To facilitate interfacial delamination between particles and resin, it is possible to adjust one or more of the following: particle size, hydrocarbon oil content, resin type, stretching temperature, stretching speed, etc.

[0020] Furthermore, as mentioned above, one of the purposes of using inorganic particles in the present invention is to impart specific functions of the inorganic particles to the film sheet. Exposed inorganic particles exhibit their functions more readily than non-exposed inorganic particles. The presence of exposed inorganic particles at the periphery of the void portion 5 facilitates the achievement of the above purpose. For example, consider the case of inorganic particles with deodorizing properties. The void portion 5 functions as a flow path for gas flowing inside and outside the film sheet. Deodorizing inorganic particles are arranged as exposed inorganic particles at the periphery of the void portion 5, that is, in a form that has exposed portions not covered by thermoplastic resin. In this case, the frequency of contact between the gas flowing through the void portion 5 and the inorganic particles is relatively high. Therefore, odor components contained in the gas are treated by the inorganic particles, making it easier to obtain a predetermined deodorizing effect.

[0021] From the viewpoint of ensuring that the effects of the presence of exposed inorganic particles at the periphery of the void portion 5 are more reliably achieved, the film sheet of the present invention has portions in which, in a 5000x observation field of view on one surface of the film sheet, the ratio of the total area of ​​exposed inorganic particles present at the periphery of the void portion 5 to the area of ​​the observation field (hereinafter also referred to as the "periphery exposed inorganic particle occupancy rate") is preferably greater than 0%, and more preferably 0.1% or more. Furthermore, from the viewpoint of improving the uniform dispersion of inorganic particles in the film sheet and scattering voids 5 throughout the film sheet, the percentage of exposed inorganic particles at the periphery is preferably 30% or less, more preferably 10% or less. The percentage of exposed inorganic particles at the periphery is measured by the following method.

[0022] <Method for measuring the percentage of exposed inorganic particles at the periphery> First, one surface of the film sheet to be measured is imaged at 5000x magnification using a SEM to obtain an observation image corresponding to the observation field. Next, the portion where exposed inorganic particles exist at the periphery of the void is extracted from the observation image, and the total area B1 of the extracted portion is calculated. Specifically, the total area S1 is calculated using the image processing software ImageJ. Then, the occupancy rate of exposed inorganic particles at the periphery is calculated using the following formula. In the following formula, "B0" refers to the area of ​​the observation field. Peripheral exposed inorganic particle occupancy rate (%) = (B1 / B0) × 100

[0023] Exposed inorganic particles can be present at the periphery of the void portion 5, for example, by employing a manufacturing method for the film sheet that includes a step of stretching an unstretched sheet containing inorganic particles. This stretching step causes delamination at the interface between the thermoplastic resin and the inorganic particles, forming the void portion 5. At the same time, the inorganic particles at the periphery of the void portion 5 come to exist in a form in which there are portions that are exposed and not covered by the thermoplastic resin.

[0024] In the present invention, it is preferable that the resin occupancy rate, which is the ratio of the total area of ​​the thermoplastic resin to the area of ​​the 5000x observation field, is within a predetermined range. The resin occupancy rate is measured by the following method.

[0025] <Method for measuring resin occupancy rate> First, one surface of the film sheet to be measured is imaged at 5000x magnification using a SEM to obtain an observation image corresponding to the observation field. Next, the portion where thermoplastic resin is present is extracted from the observation image, and the total area A1 of the extracted portion is calculated. Specifically, the total area A1 is calculated using the image processing software ImageJ. Then, the resin occupancy rate of the film sheet to be measured is calculated using the following formula. In the following formula, "A0" refers to the area of ​​the observation field. Resin occupancy (%)=(A1 / A0)×100

[0026] For example, when measuring the resin content of a film sheet of a suspected infringing product, if the film sheet is bonded to another article (e.g., nonwoven fabric) by adhesive or fusion to form a composite, it is advisable to reduce the bonding force by blowing cold air from a cold spray onto the joint, and then remove only the film sheet from the composite. This method of removing the film sheet from the composite can also be used when measuring other physical properties besides resin content.

[0027] From the viewpoint of providing the film sheet with high breathability, the resin occupancy rate is preferably 80% or less, more preferably 70% or less, and even more preferably 60% or less. The value calculated by subtracting the resin occupancy rate from 100 can be considered as the ratio of the total area of ​​the voids (areas without thermoplastic resin) to the area of ​​the 5000x observation field of view of the surface of the film sheet (hereinafter also referred to as the "void occupancy rate"). A resin occupancy rate of 80% or less is preferable, which means that a void occupancy rate of 20% or more is preferable. Generally, the lower the resin occupancy rate (the higher the void occupancy rate), the better the breathability and moisture permeability of the film sheet. Film sheets with high breathability and moisture permeability do not allow liquids such as water to pass through, but they do allow water vapor to pass through. Therefore, they are useful, for example, as sheets for clothing. Furthermore, generally speaking, the smaller the resin occupancy rate, the larger the surface area of ​​the interface between the thermoplastic resin and the outside air, making it easier to reflect light. This can improve the heat-shielding properties of the film sheet. Furthermore, generally speaking, the lower the resin occupancy rate, the more exposed inorganic particles tend to be, making it easier for the functions of the inorganic particles (for example, deodorizing function) to be expressed. From the viewpoint of providing the film sheet with practically sufficient strength (water pressure resistance, etc.), the resin occupancy rate is preferably more than 0%, more preferably 5% or more, and even more preferably 10% or more. By meeting the above requirements, a high level of both breathability and water pressure resistance (waterproofing) is achieved.

[0028] The resin content can be adjusted by appropriately adjusting the type of thermoplastic resin, the size of the inorganic particles, and their content. Furthermore, if the film sheet is manufactured through a stretching process of an unstretched sheet, the resin content can also be adjusted by appropriately adjusting the conditions of the stretching process (stretching ratio, etc.).

[0029] In the film sheet of the present invention, typically, the thermoplastic resin, which is a component of the film sheet, forms a network structure. This network structure constitutes the main body of the film sheet. Preferably, this network structure is continuous at least in the direction of the surface of the film sheet, and more preferably, it is continuous in the direction of the thickness of the film sheet. Having such a network structure of thermoplastic resin in the film sheet makes it possible to achieve the predetermined effects of the present invention more reliably. Specific examples of the aforementioned network structure are shown in Figures 1-3 and 5. In these examples, the thermoplastic resin in film sheets 1-3 surrounds a plurality of voids 5 scattered on the surface and inside of film sheets 1-3. This forms a continuous network structure 6 in both the surface direction and the thickness direction of film sheets 1-3. The aforementioned "surface direction" refers to the direction along the surface of the film sheet and is the direction that intersects with the thickness direction of the film sheet. The aforementioned "intersection" includes orthogonal directions. Figure 5 is a cross-section of the film sheet 2 shown in Figure 2, along the thickness direction. Here, it can be confirmed that the network structure 6 is continuous in the thickness direction of the film sheet 2 (the vertical direction in Figure 5). In the examples of Figures 1 and 3, the network structure 6 is continuous in the thickness direction, similar to the examples of Figures 2 and 5. Note that the film sheet 2 shown in Figures 2 and 5 is the film sheet of Example 1, which will be described later.

[0030] Whether or not a film sheet has the aforementioned network structure can be determined by observing the film sheet using a scanning electron microscope (SEM). Whether the network structure is continuous in the direction of the film sheet surface can be determined, for example, by following the procedure below. First, a 5000x magnification field of view of the film sheet surface is obtained using a SEM, as shown in Figures 1 to 3. Next, it is determined whether the thermoplastic resin has a portion that extends continuously from one end of the field of view to the other. If such a portion is confirmed, it is determined that the network structure is continuous in the direction of the film sheet surface. Furthermore, whether or not the network structure is continuous in the thickness direction of the film sheet can be determined specifically, for example, by the following procedure. First, an SEM observation field of view of a cross-section along the thickness direction of the film sheet is obtained, as shown in Figure 5. Next, it is determined whether or not the thermoplastic resin has a portion that is continuous from one end of the observation field to the other. If such a portion is confirmed, it is determined that the network structure is continuous in the thickness direction of the film sheet. The "cross-section along the thickness direction of the film sheet" can be formed as follows. First, the film sheet is immersed in liquid nitrogen. Then, a razor blade is thrust into the surface of the film sheet and the razor blade is struck with a hammer. By pressing the razor blade towards the film sheet in this way, a cross-section along the thickness direction of the film sheet can be formed. The aforementioned "one end of the field of view" and "the other end of the field of view" are typically both ends of the field of view in a predetermined direction (for example, the longitudinal direction of the field of view or a direction perpendicular to the longitudinal direction).

[0031] The film sheet of the present invention typically has a network structure having fibrous portions containing a thermoplastic resin. The fibrous portions typically contain inorganic particles (exposed inorganic particles and non-exposed inorganic particles) in addition to the thermoplastic resin. Specific examples are shown in Figures 1-3, where the network structure 6 has a plurality of fibrous portions 7. The fibrous portion 7 is an elongated portion mainly composed of thermoplastic resin. Specifically, the fibrous portion 7 extends in one direction, and the maximum length (width) in the direction perpendicular to the direction of extension (hereinafter also referred to as the "radial direction") is shorter than the length in that direction. In this specification, the length along the radial direction of the fibrous portion 7 is referred to as the "width." The width of the fibrous portion 7 is the so-called thickness of the fibrous portion 7. The "maximum width" is the thickness of the thickest part of the fibrous portion 7. For example, if the cross-sectional shape along the radial direction of the fibrous portion 7 is a perfect circle, the width of the fibrous portion 7 is the diameter of the perfect circle. Also, for example, if the cross-sectional shape along the radial direction of the fibrous portion 7 is an ellipse, the width of the fibrous portion 7 is the length of the major axis of the ellipse. The cross-sectional shape of the fibrous portion 7 along the radial direction is not particularly limited and may be, for example, circular, polygonal, or plate-shaped. The circular shape may be a perfect circle, an ellipse, etc. The polygonal shape may be a triangle, a square, a pentagon, etc. Because the network structure 6 has fibrous portions 7, the resin occupancy rate tends to be lower compared to the case where there are no fibrous portions 7. Therefore, an improvement in the properties of the film sheet (breathability, moisture permeability, heat shielding, etc.) can be expected due to the reduction in resin occupancy rate, and the predetermined effects of the present invention will be achieved more reliably.

[0032] The width of the fibrous portion 7 is preferably 0.001 μm or more, more preferably 0.01 μm or more, and even more preferably 0.05 μm or more, from the viewpoint of ensuring the strength of the film sheet. Furthermore, the width of the fibrous portion 7 is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 2 μm or less, from the viewpoint of ensuring breathability and moisture permeability of the film sheet. In the present invention, the "fibrous portion" can be defined as "an elongated portion of a film sheet mainly composed of a thermoplastic resin, wherein the width of the elongated portion falls within the specified range." In addition, the "fibrous portion" has a ratio of length to width in the direction of extension of the "elongated portion" that is preferably 0.5 or more, more preferably 1 or more, and even more preferably 2 or more as length / width. This results in a film sheet with excellent breathability. Furthermore, the fibrous portion has a length / width ratio of preferably 50 or less, more preferably 40 or less, and even more preferably 30 or less. This results in a film sheet with excellent strength. In this specification, "primarily composed of thermoplastic resin" means that the content of thermoplastic resin in the relevant portion (e.g., fibrous portion) is 30% by mass or more, 40% by mass or more, or 100% by mass or less, based on the total mass of the relevant portion. The width (maximum width) of the fibrous portion 7 is determined by acquiring observation images corresponding to a 5000x observation field of view as shown in Figures 1 to 3, and then measuring the width using a measuring instrument such as a ruler based on these observation images.

[0033] In the film sheet of the present invention, typically, at least a portion of the plurality of fibrous portions 7 includes, when focusing on one of the fibrous portions 7, the single fibrous portion 7 and one or more other fibrous portions 7 branching off from the single fibrous portion 7. That is, in the film sheet, the network structure 6 is composed of a plurality of fibrous portions 7. In addition, at least a portion of the network structure 6 includes a structure in which one or more other fibrous portions 7 branch off from one fibrous portion 7. Typically, the plurality of fibrous portions 7 constituting the network structure 6 are joined together at their contact points and are integrated. The contact points are the joining points between the fibrous portions 7, and a plurality of such joining points are scattered throughout the network structure 6.

[0034] The film sheet of the present invention maintains its sheet shape without requiring fusion points and entanglement points between the fibrous portions 7, due to the presence of the aforementioned bonding points. Therefore, it is preferable that the film sheet does not have fusion points and entanglement points between the fibrous portions 7. Generally, when a sheet is manufactured using resin fibers and by fusing or entangling the resin fibers together, the sheet will have fusion points or entanglement points between the fibrous portions made of the resin fibers. Therefore, it is preferable that the film sheet of the present invention be manufactured through a stretching process of an unstretched sheet containing a thermoplastic resin and inorganic particles. In this case, the fibrous portion 7 is formed in the stretching process when delamination occurs at the interface between the thermoplastic resin and the inorganic particles, forming a void portion 5.

[0035] The fibrous portion 7 typically contains inorganic particles. When focusing on a single fibrous portion, the film sheet preferably has a portion S in which the "ratio of the particle diameter (maximum span length) of the inorganic particles on the fibrous portion 7 to the width of the fibrous portion 7" (hereinafter also referred to as the "ratio of inorganic particle diameter / fiber width") is within the following range. The "inorganic particles on the fibrous portion 7" refers to inorganic particles supported and fixed on the fibrous portion 7. From the viewpoint of ensuring that exposed inorganic particles are reliably present at the periphery of the void portion 5 and thereby more reliably achieving the predetermined effects of the present invention, a larger ratio of inorganic particle diameter to fiber width is preferable. Specifically, the ratio of inorganic particle diameter to fiber width is preferably 0.01 or higher, more preferably 0.1 or higher, and even more preferably 0.2 or higher. Furthermore, from the viewpoint of imparting sufficient practical strength to the film sheet, the smaller the size, the better. Specifically, the ratio of inorganic particle diameter to fiber width is preferably 1000 or less, more preferably 500 or less, and even more preferably 300 or less. The aforementioned "particle diameter (maximum span length) of inorganic particles" and "width of fibrous portion" are determined by acquiring observation images corresponding to a 5000x observation field of view, and then measuring them using measuring instruments such as rulers based on these observation images.

[0036] From the viewpoint of more reliably expressing the functions of the inorganic particles, it is preferable that the fibrous portion 7 has portions where the width of the fibrous portion 7 is smaller than the particle diameter of the inorganic particles, when focusing on a single fibrous portion. That is, it is preferable that the ratio of inorganic particle diameter to fiber width of portion S exceeds 1. Specifically, the ratio of inorganic particle diameter to fiber width of portion S is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. Furthermore, from the viewpoint of reliably supporting inorganic particles in the fibrous portion 7, the ratio of inorganic particle diameter to fiber width in portion S is preferably 20 or less, more preferably 10 or less, and even more preferably 5 or less.

[0037] The film sheet of the present invention preferably has multiple fibrous portions having a predetermined arrangement direction (extension direction). Specifically, the film sheet of the present invention preferably has an orientation degree of the fibrous portions measured by the following method in a 5000x observation field of view that is within the following range. The aforementioned degree of orientation is an indicator of the orientation of the fibrous portions in the film sheet in two mutually orthogonal directions. The degree of orientation is 1 when the number of fibrous portions extending in one direction is equal to the number of fibrous portions extending in the other direction. The greater the degree of orientation (greater than 1) or the less than 1, the more the direction of extension of the fibrous portions is biased towards one of the two directions. Therefore, the closer the degree of orientation is to 1, the less anisotropy there is in the fibrous portions of the film sheet. The smaller the anisotropy of the fibrous portion, the better the mechanical properties, for example, the higher the water pressure resistance. From the viewpoint of obtaining a film sheet with excellent mechanical properties, the degree of orientation of the fibrous portion is preferably 0.3 to 3, more preferably 0.5 to 2, and even more preferably 0.7 to 1.5. The above effects are particularly pronounced when the film sheet is mainly composed of fibrous material. Here, "mainly composed of fibrous material" means that in a 5000x observation field of view on one surface of the film sheet, the ratio of the total area of ​​the fibrous material to the area of ​​the observation field (hereinafter also referred to as the "fibrous material occupancy rate") is preferably 20% to 100%, more preferably 40% or more. The "total area of ​​the fibrous material" can be determined by subtracting the total area of ​​the non-fibrous material portion (the non-fibrous portion described later) in the observation field from the area of ​​the 5000x observation field.

[0038] <Method for measuring the degree of orientation of fibrous parts> The explanation will be given with reference to Figure 6. Figure 6 shows a schematic diagram of the observation image OI, which is an image of one surface of the film sheet to be measured, magnified 5000 times by SEM. The observation image OI is the image corresponding to the 5000x observation field of view. A square SQ with a side length of 15 μm is created in the observation image OI. The number of fibrous portions 7 that cross both the top and bottom pair of sides L1 and L2 in the square SQ is defined as the "top and bottom fiber count," and the number of fibrous portions 7 that cross both the left and right pair of sides L3 and L4 in the square SQ is defined as the "left and right fiber count." The ratio of the left and right fiber count to the top and bottom fiber count (left and right fiber count / top and bottom fiber count) is calculated, and this ratio is defined as the degree of orientation of the fibrous portions of the film sheet being measured.

[0039] The degree of orientation of the fibrous portion of the film sheet can be adjusted by appropriately adjusting the manufacturing method. Specifically, the manufacturing method for the film sheet involves a step of stretching an unstretched sheet containing inorganic particles. The stretching method in the aforementioned step is then appropriately adjusted. When uniaxial stretching is used as the stretching method, the multiple fibrous portions in the resulting film sheet extend along the stretching direction. Therefore, the degree of orientation of the fibrous portions is generally high. On the other hand, if biaxial stretching is used as the stretching method, the degree of orientation of the fibrous portion can be reduced. Specifically, the first stretching produces a sheet that is strongly oriented in the stretching direction. Then, a second stretching is performed in a direction intersecting the first stretching direction (stretching intersecting direction). As a result, the fibrous portion that was initially oriented in the stretching direction is also pulled in the stretching intersecting direction. Consequently, the final degree of orientation is reduced. The final degree of orientation can be reduced particularly if the stretching intersecting direction is perpendicular to the stretching method.

[0040] From the viewpoint of improving the mechanical properties (water pressure resistance, etc.) of the film sheet, a plan view shape of the void portion of the film sheet with low anisotropy is preferable, and one of the ideal plan view shapes is a perfect circle. In the examples shown in Figures 1 and 2, the plan view shape of the void portion 5 is closer to a circle or ellipse than in the example shown in Figure 3, and has lower anisotropy compared to the void portion 5 of the film sheet 3. Based on the above, from the viewpoint of improving the mechanical properties of the film sheet, it is preferable that, in a 5000x observation field of view of one surface of the film sheet, at least a portion of the multiple voids have a ratio of the length in the long axis direction to the length in the short axis direction within a specific range. Here, the specific range is preferably 0.3 or more and 3 or less, more preferably 0.5 or more and 2 or less, and even more preferably 0.7 or more and 1.5 or less as the ratio of the length in the long axis direction to the length in the short axis direction. The term "long axis direction" refers to the direction of extension of the portion having the maximum span length in the void in the 5000x observation field. The term "length in the long axis direction" refers to the maximum span length. The term "length in the short axis direction" refers to the maximum span length in the direction perpendicular to the long axis direction of the void.

[0041] In the present invention, it is preferable that, in a 5000x observation field, the void portion 5 located on the surface of the film sheet and the fibrous portion 7 located inside the film sheet overlap in the thickness direction of the film sheet. In other words, when the void portion 5 located on the surface of the film sheet and the fibrous portion 7 located inside the film sheet are projected in the thickness direction of the film sheet, it is preferable that the projected images of the two overlap. The film sheet has such a configuration, resulting in excellent breathability.

[0042] In the film sheet of the present invention, the network structure may have non-fibrous portions other than the plurality of fibrous portions. As a result, a film sheet having non-fibrous portions tends to have superior strength compared to a film sheet without non-fibrous portions. In the specific example shown in Figure 2, the network structure 6 of the film sheet 2 has non-fibrous portions 8 in addition to the fibrous portions 7. On the other hand, in the specific example shown in Figure 1, the network structure 6 of the film sheet 1 does not have non-fibrous portions 8.

[0043] The "non-fibrous portion" is a non-elongated portion in the network structure. In other words, the "non-fibrous portion" is a part of the network structure made of thermoplastic resin in which no fibrous portions are present. In the aforementioned "non-fibrous portion," the ratio of the maximum extension length to the minimum extension length, expressed as maximum extension length / minimum extension length, is preferably 0.3 to 3, more preferably 0.5 to 2, and even more preferably 0.7 to 1.5, in a 5000x observation field. This results in a film sheet with excellent strength. In this invention, the "non-fibrous portion" can be defined as "a portion of the film sheet other than the fibrous portion, mainly composed of thermoplastic resin, where the ratio of the maximum extension length to the minimum extension length in the 5000x observation field of view falls within the specified range." The "minimum extension length" and "minimum extension length" are determined by acquiring an observation image corresponding to the 5000x observation field of view and measuring it using a measuring instrument such as a ruler based on the observation image.

[0044] In the present invention, it is preferable that, in a 5000x observation field, the void portion 5 located on the surface of the film sheet and the non-fibrous portion 8 located inside the film sheet overlap in the thickness direction of the film sheet. In other words, when the void portion 5 located on the surface of the film sheet and the non-fibrous portion 8 located inside the film sheet are projected in the thickness direction of the film sheet, it is preferable that the projected images of the two overlap. Due to these characteristics, the film sheet has excellent strength, and specifically, for example, excellent water pressure resistance.

[0045] The film sheet of the present invention typically contains a thermoplastic resin. From the viewpoint of ensuring the toughness of the film sheet, the thermoplastic resin content in the film sheet of the present invention is preferably 10% by mass or more, more preferably 25% by mass or more, and even more preferably 35% by mass or more, based on the total mass of the film sheet. Furthermore, the thermoplastic resin content in the film sheet of the present invention is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less, from the viewpoint of ensuring breathability and moisture permeability of the film sheet.

[0046] The thermoplastic resin used in this invention, that is, the thermoplastic resin that forms the main body of the film sheet of this invention, is a thermoplastic resin other than an acrylic polymer. The film sheet of this invention does not contain an acrylic polymer as the main body of the film sheet. However, it may contain an acrylic polymer as a dispersant along with a thermoplastic resin other than an acrylic polymer and a plurality of inorganic particles. This will be described later.

[0047] Assuming that the thermoplastic resin used in this invention is a thermoplastic resin other than an acrylic polymer, any thermoplastic resin conventionally used in this type of film sheet can be used without particular limitation. For example, it may include one or more selected from polyolefin resins, polyester resins, polyamide resins, and vinyl resins. The polyolefin resin may include one or more selected from polyethylene, polypropylene (PP), ethylene-α-olefin copolymer, and ethylene-propylene copolymer. The PE may include one or more selected from high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene (LLDPE). The polyester resin may include one or more selected from polyethylene terephthalate, polybutylene terephthalate, and polylactic acid resins. The polylactic acid-based resin may contain one or more selected from polylactic acid and lactic acid-hydroxycarboxylic acid copolymers. The vinyl resin may include one or more selected from polyvinyl chloride, polyvinylidene chloride, and polystyrene.

[0048] From the viewpoint of improving thermal stability, the thermoplastic resin preferably contains a polyolefin resin. The polyolefin resin content in the thermoplastic resin in the film sheet is 90% by mass or more and 100% by mass or less, preferably 95% by mass or more and 100% by mass or less, and more preferably 100% by mass, based on the total mass of the thermoplastic resin. Whether or not a polyolefin resin is contained in the thermoplastic resin constituting the film sheet, and the polyolefin resin content in the thermoplastic resin, can be determined by NMR spectroscopy, IR spectroscopy, or the like.

[0049] From the viewpoint of ensuring that the predetermined effects of the present invention are achieved more reliably, the thermoplastic resin used in the present invention has a melt flow rate (MFR) measured in accordance with JIS K 7210, preferably 0.5 g / min to 100 g / 10 min, more preferably 1 g / 10 min to 60 g / 10 min, and even more preferably 2 g / 10 min to 15 g / 10 min. The MFR can be measured in accordance with JIS K 7210 by heating and loading according to the type of polyolefin resin. For example, when polypropylene, which is a polyolefin resin, is used as the thermoplastic resin, it is measured under conditions of a temperature of 190°C and a load of 21.18 N.

[0050] From the viewpoint of ensuring that the predetermined effects of the present invention are achieved more reliably, the content of multiple inorganic particles in the film sheet of the present invention is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on the total mass of the film sheet. Furthermore, from the viewpoint of improving stretchability, the content of multiple inorganic particles is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 43% by mass or less. The content of multiple inorganic particles in a film sheet can be measured using a scanning electron microscope (SEM) with an EDS (Electronic Data Scale).

[0051] The inorganic particles used in this invention are not particularly limited to those conventionally used in this type of film sheet. For example, they may include one or more selected from minerals, metal carbonates, metal oxides, metal sulfates, metal phosphates, metal hydroxides, carbon particles, and metal particles. The aforementioned minerals may include one or more selected from gypsum, talc, clay, kaolin, silica, mica, aluminosilicate, and diatomaceous earth. The metal carbonate may include one or more selected from calcium carbonate, magnesium carbonate, and barium carbonate. The metal oxide may include one or more selected from aluminum oxide, aluminum oxide, zinc oxide, and titanium oxide. The metal sulfate may include one or more selected from sodium sulfate, calcium sulfate, magnesium sulfate, and barium sulfate. The aforementioned metal phosphate may include calcium phosphate. The metal hydroxide may include aluminum hydroxide. The carbon particles may include one or more selected from activated carbon and carbon black. The metal particles may include one or more selected from aluminum powder, iron powder, and copper powder. The shape of the inorganic particles is not particularly limited and may be spherical, lumpy, fibrous, or amorphous, for example.

[0052] From the viewpoint of improving the handling and moldability of the film sheet, the inorganic particles preferably contain one or more selected from zinc oxide, calcium carbonate, aluminosilicate, and titanium oxide.

[0053] In the present invention, it is preferable that the inorganic particles themselves are not covered by any other substance. Here, "inorganic particles themselves are not covered by any other substance" means that, in the state before they are incorporated into the film sheet (the state of the raw materials before they are used in the manufacture of the film sheet), the surface of the inorganic particles is not coated with any other substance. In other words, it means that the inherent surface state of the inorganic particles is exposed. For example, surface-treated inorganic particles, in which a dispersant is adsorbed onto the surface of inorganic particles, are often used as raw materials to improve the dispersibility of inorganic particles in film sheets. In the present invention, it is preferable that the product substantially does not contain such surface-treated inorganic particles. Because the inorganic particles themselves are not covered by other materials, it becomes easier to impart the functions inherent in those inorganic particles to the film sheet.

[0054] Whether or not inorganic particles themselves are covered by other substances can be confirmed by observing the surface of the film sheet using a scanning electron microscope (SEM). Whether or not inorganic particles themselves are covered by other substances can also be confirmed by whether or not the film sheet exhibits the function of the inorganic particles. For example, if the inorganic particles contained in the film sheet are zinc oxide, an adsorption test of acetic acid gas is performed on the film sheet. If adsorption of acetic acid gas by the film sheet is observed, it is evaluated that the inorganic particles (zinc oxide) themselves are not covered by other substances in the film sheet. The phrase "inorganic particles themselves are not covered by other substances" as used here is not limited to a state where all of the inorganic particles contained in the film sheet are not covered by other substances. It includes a state where some of the inorganic particles are covered by other substances, provided that the inorganic particles are able to perform their function. The acetic acid gas adsorption test described above can be performed using the following procedure. Specifically, the film sheet to be evaluated and acetic acid gas are sealed inside a 5L non-permeable bag, and the bag is left to stand for 30 minutes. After that, the concentration of acetic acid gas inside the bag is measured. If the concentration of acetic acid gas after standing for 30 minutes has decreased compared to that before standing for 30 minutes, it is evaluated that adsorption of acetic acid gas occurred by the film sheet. In other words, it is evaluated that the inorganic particles (zinc oxide) themselves are not covered by other substances. The concentration of acetic acid gas can be measured using a gas concentration meter (detector tube manufactured by Gastec Co., Ltd.).

[0055] From the viewpoint of ensuring that the predetermined effects of the present invention are achieved more reliably, the average particle diameter of the inorganic particles is preferably 0.1 μm to 10 μm, more preferably 0.5 μm to 5 μm, and even more preferably 1 μm to 3 μm. By adjusting the average particle diameter of the inorganic particles to the above preferred range, when a manufacturing method for a film sheet is adopted that includes a step of stretching a sheet containing inorganic particles, the sheet becomes less likely to break during this step. The average particle diameter of the inorganic particles can be measured by the following method.

[0056] <Method for measuring the average particle size of inorganic particles> The average particle size of inorganic particles can be defined as the volume-based median diameter measured by a laser diffraction particle size distribution analyzer. The median diameter is measured using a LA-950V2 manufactured by Horiba, Ltd., with a standard dry cell, and the refractive index is set to 3.5 for the real part and 3.8i for the imaginary part.

[0057] The film sheet of the present invention may further contain a dispersant for inorganic particles (hereinafter also simply referred to as "dispersant") in addition to the thermoplastic resin and inorganic particles. By including a dispersant in the film sheet, the dispersibility of inorganic particles in the film sheet is improved, making it easier to adjust the void occupancy rate to the specified range.

[0058] From the viewpoint of improving the dispersibility of inorganic particles without covering their surface, the film sheet of the present invention preferably contains an acrylic polymer. The acrylic polymer functions as a dispersant in a film sheet containing a thermoplastic resin other than the acrylic polymer and inorganic particles. The acrylic polymer may be a monomeric (co)polymer. The monomer may include one or more selected from acrylic acid and its derivatives, methacrylic acid and its derivatives, crotonic acid and its derivatives, acrylamide, acrylalkylamide, acrylonitrile, diacetoneacrylamide, and methacrylamide. The acrylic polymer may include one or more constituent units selected from acrylic acid esters and methacrylic acid esters. Specifically, the acrylic polymer may include one or more selected from polymers of acrylic acid esters, polymers of methacrylic acid esters, and copolymers of acrylic acid esters and methacrylic acid esters. The acrylic acid ester may include alkyl acrylates. The methacrylic acid ester may include alkyl methacrylic acid esters. The copolymer of the acrylic acid ester and the methacrylic acid ester may include an alkyl methacrylate-alkyl acrylate copolymer. The acrylic polymer preferably has a total proportion of 70 mol% or more of constituent units derived from alkyl acrylate and alkyl methacrylate, more preferably 80 mol% or more, even more preferably 90 mol% or more, or particularly preferably 95 mol% or more.

[0059] The acrylic polymer content in the film sheet of the present invention is preferably 1.1% by mass or more and 20% by mass or less, more preferably 2% by mass or more and 10% by mass or less, and even more preferably 2.5% by mass or more and 5% by mass or less, based on the total mass of the film sheet.

[0060] From the viewpoint of improving the dispersibility of inorganic particles, it is preferable that the film sheet of the present invention further contains one or more selected from silicone oil and hydrocarbon oil in addition to the acrylic polymer. The silicone oil may contain one or more selected from methylpolysiloxane and higher alcohol-modified organopolysiloxane. The methylpolysiloxane may include one or more selected from dimethylpolysiloxane, dimethylcyclopolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane. In this specification, the term hydrocarbon oil is a concept that includes fatty acids and their salts and esters. The hydrocarbon oil may include caprylic acid, palmitic acid, oleic acid, stearic acid, capric acid, lauric acid, erucic acid, myristic acid and their salts, as well as one or more selected from the following polyesters. The aforementioned polyester includes those obtained from a polybasic acid and a polyhydric alcohol, and / or those obtained from a monobasic acid having 14 to 22 carbon atoms and a monohydric alcohol having 12 to 22 carbon atoms.

[0061] The total content of silicone oil and hydrocarbon oil in the film sheet of the present invention is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, based on the total mass of the film sheet. This allows for good dispersibility of inorganic particles in the film sheet. Furthermore, when a film sheet is manufactured by performing a stretching process on an unstretched sheet containing thermoplastic resin and inorganic particles, the porosity of the unstretched sheet during stretching can be improved. Good porosity makes it easier to obtain a film sheet with good air permeability and water pressure resistance. Furthermore, the total content of silicone oil and hydrocarbon oil in the film sheet of the present invention is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on the total mass of the film sheet. This prevents oil derived from silicone oil or hydrocarbon oil from seeping out of the film sheet (bleed-out).

[0062] Whether or not the film sheet contains the aforementioned dispersant, acrylic polymer, silicone oil, and hydrocarbon oil can be confirmed using an EDS-equipped SEM.

[0063] The film sheet of the present invention preferably contains substantially no β-nucleating agent. In film sheets mainly composed of this type of thermoplastic resin, a resin nucleating agent may be used to change the crystal structure of the thermoplastic resin and obtain desired properties. For example, when PP is used as the thermoplastic resin, a β-nucleating agent may be included in the film sheet to change the crystal structure of PP to a β-crystal. The film sheet of the present invention can exhibit the desired effects even without containing a β-nucleating agent by undergoing biaxial stretching during manufacturing. Furthermore, by not including a β-nucleating agent in the film sheet, stretching during manufacturing can be facilitated. Whether or not a film sheet contains a β-nucleating agent, and the amount of β-nucleating agent in the film sheet, can be determined using methods such as IR spectroscopy.

[0064] The film sheet of the present invention preferably contains substantially no fluorine-containing compounds. Fluorine-containing compounds may be included in film sheets, for example, to improve the dispersibility of inorganic particles or to improve resin processability. The film sheet of the present invention can achieve the desired effects without containing fluorine-containing compounds by incorporating acrylic polymers and / or silicone oils. Furthermore, by adjusting the content of fluorine-containing compounds in the film sheet to the aforementioned specific range, the environmental impact can be reduced.

[0065] In this specification, "substantially free" means that the content of the said component (e.g., fluorine-containing compound) in the film sheet of the present invention is, specifically, 0% by mass or more and 1.0% by mass or less, more specifically 0.8% by mass or less, and even more specifically 0.5% by mass or less, relative to the total mass of the film sheet.

[0066] The breathability of a film sheet is expressed by its air permeability. Air permeability can be measured according to JIS P8117:2009. Air permeability is expressed as the time it takes for a certain amount of air to pass through the object being measured (film sheet). A smaller air permeability value indicates that the object being measured has better breathability. From the viewpoint of ensuring the strength of the film sheet of the present invention, the air permeability is preferably 0 seconds / 100 mL or more, and more preferably 50 seconds / 100 mL or more. Furthermore, from the viewpoint of ensuring moisture permeability, the air permeability of the film sheet is preferably 20,000 seconds / 100 mL or less, more preferably 6,000 seconds / 100 mL or less, even more preferably 5,000 seconds / 100 mL or less, and even more preferably 4,000 seconds / 100 mL or less. The degree of air permeability can be adjusted by changing the resin content of the film sheet.

[0067] The air permeability of the film sheet of the present invention is preferably adjusted as appropriate depending on the application of the film sheet. For example, when the film sheet of the present invention is used as a sheet for clothing, the air permeability of the film sheet is preferably 10 seconds / 100 mL or more, more preferably 50 seconds / 100 mL or more, and even more preferably 100 seconds / 100 mL or more, from the viewpoint of ensuring the strength of the film sheet. Furthermore, when the film sheet of the present invention is used as a sheet for clothing, the air permeability of the film sheet is preferably 3000 seconds / 100 mL or less, more preferably 1000 seconds / 100 mL or less, and even more preferably 800 seconds / 100 mL or less, from the viewpoint of reducing stuffiness.

[0068] From the viewpoint of reducing stuffiness, the film sheet of the present invention preferably has a moisture permeability of 2000 g / m². 2 24 hours or more, more preferably 3000 g / m² 2 24 hours or more, more preferably 4000 g / m² 2 • It is 24 hours or longer. Furthermore, from the viewpoint of ensuring the strength of the film sheet, the moisture permeability is preferably 20,000 g / m². 2 • 24 hours or less, more preferably 15,000 g / m² 2 • 24 hours or less, more preferably 10,000 g / m² 2 • Less than 24 hours Film sheets with moisture permeability within this range are particularly useful as clothing sheets. The moisture permeability can be measured according to JIS Z0208. The moisture permeability can be adjusted by changing the resin content of the film sheet.

[0069] From the viewpoint of ensuring waterproofness that can prevent the intrusion of rainwater and the like, the water pressure resistance of the film sheet of the present invention is preferably 10,000 mmAq or more, more preferably 15,000 mmAq or more, and even more preferably 20,000 mmAq or more. Furthermore, from the viewpoint of achieving compatibility with breathability, the water pressure resistance is preferably 100,000 mmAq or less, more preferably 80,000 mmAq or less, and even more preferably 50,000 mmAq or less. Water pressure resistance can be measured according to the hydrostatic water resistance test (hydrostatic method) Method A (low water pressure method) of JIS L1092-1998. Water pressure resistance can be adjusted by adjusting the resin occupancy rate of the film sheet.

[0070] The through-holes in a typical nonwoven fabric, which penetrate the fabric in the thickness direction, consist of voids between the constituent fibers of the nonwoven fabric. The maximum span of these through-holes in a plan view is usually greater than 100 μm, and typically between 100 μm and 10,000 μm. The film sheet of the present invention preferably has through holes that penetrate the film sheet in the thickness direction. From the viewpoint of ensuring breathability and moisture permeability, it is preferable that the through holes consist only of through holes whose maximum span length in a plan view is greater than 0 μm and less than or equal to 100 μm (hereinafter also referred to as "specific through holes"). In other words, it is preferable that the film sheet of the present invention does not have through holes with a maximum span length exceeding 100 μm, which are commonly found in nonwoven fabrics. The fact that a film sheet may only have specific through-holes indicates that it was not manufactured using resin fibers as raw materials, as is the case with nonwoven fabrics, but rather through a stretching process of an unstretched sheet containing thermoplastic resin and inorganic particles. Whether or not a film sheet contains only specific types of through-holes can be determined by observing the film sheet using a scanning electron microscope (SEM).

[0071] The thickness of the film sheet of the present invention is not particularly limited and can be adjusted as appropriate depending on the application of the film sheet. For example, when the film sheet of the present invention is used as a moisture-permeable sheet, a sheet for clothing, a heat-shielding sheet, or an agricultural sheet, the thickness of the film sheet is preferably greater than 0 μm and less than or equal to 100 μm. When used as a moisture-permeable sheet or a sheet for clothing, the thickness of the film sheet is more preferably 20 μm to 50 μm. When used as a heat-shielding sheet or an agricultural sheet, the thickness of the film sheet is more preferably 40 μm to 100 μm. The thickness of a general non-woven fabric is usually 100 μm or more and 3000 μm or less. That is, the film sheet of the present invention is typically significantly thinner than a general non-woven fabric. In this specification, "the thickness of the film sheet" refers to the thickness under a load of 0.8 kPa. The thickness of the film sheet can be measured using a micrometer MDH-25MB manufactured by Mitutoyo Corporation.

[0072] The basis weight of the film sheet of the present invention is not particularly limited and can be appropriately adjusted according to the use of the film sheet and the like. For example, when the film sheet of the present invention is used as a moisture-permeable sheet, a clothing sheet, a heat-insulating sheet, or an agricultural sheet, the basis weight of the film sheet is usually 30 g / m 2 or more and 80 g / m 2 or less. When used as a moisture-permeable sheet or a clothing sheet, the basis weight of the film sheet is more preferably 10 g / m 2 or more and 50 g / m 2 or less. When used as a heat-insulating sheet or an agricultural sheet, the basis weight of the film sheet is more preferably 40 g / m 2 or more and 120 g / m 2 or less.

[0073] The film sheet of the present invention is particularly useful as a moisture-permeable sheet, a clothing sheet, a heat-insulating sheet, or an agricultural sheet. The moisture-permeable sheet refers to a sheet used in applications where moisture permeability is required. The moisture-permeable sheet includes those used for fabrics used in absorbent articles, clothing, shoes, hats, outdoor supplies, etc. The absorbent article refers to an article used for absorbing body fluids (urine, soft feces, menstrual blood, sweat, etc.) discharged from the human body, and includes disposable diapers, sanitary napkins, menstrual shorts, and incontinence pads. The film sheet of the present invention is useful, for example, as a back sheet disposed on the outer surface side (opposite side to the wearer's skin side) of an absorbent article. The clothing sheet refers to a sheet used in the manufacture of clothing. The film sheet of the present invention is useful, for example, for clothing that requires waterproofness and moisture permeability, such as raincoats. The aforementioned heat-shielding sheets refer to sheets used in applications where heat shielding is required. Heat-shielding sheets include sheets used in automobile manufacturing, building materials, clothing fabrics, outdoor equipment, and curtains. The aforementioned agricultural sheets refer to sheets used in agriculture.

[0074] An example of a film sheet suitable for a moisture-permeable sheet is the following film sheet X. Film sheet X contains PP as a thermoplastic resin other than the acrylic polymer. Film sheet X contains one or more selected from calcium carbonate, zinc oxide, titanium dioxide, and aluminosilicate as inorganic particles. In addition, film sheet X contains an alkyl methacrylate / alkyl acrylate copolymer as the acrylic polymer which acts as a dispersant. Film sheet X contains one or more selected from dimethylpolysiloxane and methylhydrogenpolysiloxane as the silicone oil. Film sheet X contains stearic acid as the hydrocarbon oil.

[0075] The film sheet of the present invention may be a single sheet. In this specification, "single sheet" means that the portion capable of achieving all the effects expected of the sheet is realized in a single sheet. Specifically, as described above, the film sheet of the present invention achieves the effect of achieving both high levels of breathability and water pressure resistance. When the film sheet is a single sheet, this balance is achieved by the film sheet alone, rather than by lamination with other sheets. "Single sheet" can also be said to mean a sheet in which a portion of the sheet is capable of achieving the effects expected of the sheet. A single sheet may have either a single-layer structure or a laminated structure. If a single sheet has a laminated structure, each of the multiple layers constituting the laminated structure will produce the effect expected of the sheet. For example, a sheet comprising a layer that exhibits only some of the expected effects of the sheet (e.g., only high breathability) and a layer that exhibits only other parts of the effects (e.g., only high water pressure resistance) is not a "single sheet" as defined herein. Compared to such a sheet, a single sheet has the advantage that even if a part of the sheet is damaged, the other parts can maintain the expected effects of the sheet.

[0076] The present invention includes sheet articles having a laminated structure of the film sheet of the present invention described above and other sheets other than the film sheet. The aforementioned other sheets are not particularly limited and include, for example, woven fabrics, nonwoven fabrics, paper, and resin sheets other than the film sheet. The laminated structure may be a two-layer structure consisting of the film sheet and the other sheet, or it may be a three-layer or more laminated structure in which the film sheet or the other sheet is bonded to one or both sides of the two-layer structure. Each layer constituting the laminated structure is joined and integrated with each other by known bonding means such as adhesive or fusion.

[0077] In one preferred embodiment of the sheet article of the present invention, the other sheet is arranged on one side of the film sheet, and the other side of the film sheet is exposed. In this way, by exposing one side of the film sheet without being covered by the other sheet, the characteristics of the film sheet, such as high breathability and high moisture permeability, are more easily exhibited. In this embodiment, a woven fabric is preferred as the other sheet. The sheet articles of the present invention are particularly useful as moisture-permeable sheets, clothing sheets, heat-shielding sheets, or agricultural sheets.

[0078] The present invention includes wearable articles containing a film sheet. The wearable article of the present invention will be described below. The wearable article of the present invention will be described in a manner different from that of the film sheet of the present invention. For configurations of the wearable article of the present invention that are not described, the above-mentioned description of the film sheet of the present invention will apply as appropriate.

[0079] The film sheet constituting the wearable article of the present invention preferably contains a thermoplastic resin and a plurality of inorganic particles. Typically, in the film sheet, a plurality of voids where the thermoplastic resin is absent extend through the thermoplastic resin. It is preferable that exposed inorganic particles, among the plurality of inorganic particles, which have portions exposed from the thermoplastic resin, are present at the periphery of the plurality of voids. A preferred example of a film sheet constituting the wearable article of the present invention is the film sheet of the present invention described above. In this preferred example, the film sheet constituting the wearable article of the present invention typically has a network structure formed by a thermoplastic resin which is a component of the film sheet, and this network structure constitutes the main body of the film sheet. In this network structure, a plurality of voids extend through the thermoplastic resin.

[0080] The wearable articles of the present invention may be clothing, shoes, hats, or articles used to absorb bodily fluids discharged from the human body (hereinafter also referred to as "bodily fluid absorbing articles"). Examples of the aforementioned clothing include rainwear, sportswear, and outdoor wear. In the aforementioned clothing, the film sheet may function as, for example, a breathable waterproof film, a deodorizing film, or a heat-shielding film. In the aforementioned shoes, the film sheet may function, for example, as a breathable waterproof film or a deodorizing film. In the aforementioned hat, the film sheet can function, for example, as a breathable waterproof film, a deodorizing film, or a heat-shielding film. Examples of the bodily fluid absorbent articles include disposable diapers, sanitary napkins, and incontinence pads. In the bodily fluid absorbent article, the film sheet can function, for example, as a surface sheet positioned to come into contact with the wearer's skin when worn, or as a waterproof film used as the outer layer of the bodily fluid absorbent article.

[0081] The method for manufacturing the film sheet of the present invention will be described below. For aspects of the method for manufacturing the film sheet of the present invention that are not specifically described, the above-mentioned description of the film sheet of the present invention will apply as appropriate.

[0082] The present invention provides a method for manufacturing a film sheet, which typically includes a step of stretching an unstretched sheet containing a thermoplastic resin and inorganic particles (stretching step). The unstretched sheet is typically manufactured by a step of manufacturing a resin composition containing a thermoplastic resin and inorganic particles (resin composition manufacturing step) and a step of molding the resin composition into a sheet (molding step). The present invention provides a method for manufacturing a film sheet, which may include the resin composition manufacturing step and the molding step before the stretching step.

[0083] The resin composition manufacturing process can be carried out, for example, by heating and kneading a raw material containing a thermoplastic resin and inorganic particles in a single-screw or twin-screw extruder. This yields a molten resin composition. The content of the thermoplastic resin and inorganic particles in the resin composition can be appropriately adjusted so that the content in the film sheet to be manufactured falls within the aforementioned range. If the film sheet to be manufactured contains other components (e.g., a dispersant for inorganic particles) in addition to the thermoplastic resin and inorganic particles, these other components can be included in the raw material. The heating temperature in the aforementioned heating and kneading process (the temperature of the raw materials during heating and kneading) can be set according to the type of thermoplastic resin. For example, if it is a polyolefin resin, the temperature can be between 120°C and 210°C.

[0084] In the molding process, the molten resin composition produced in the resin composition manufacturing process is molded into a sheet using a molding apparatus to obtain a molded body. Next, the molded body is cooled to produce an unstretched sheet. Since the unstretched sheet is formed from a resin composition containing a thermoplastic resin and inorganic particles, the resin composition and the unstretched sheet have substantially the same composition. The molding apparatus is not particularly limited, and for example, a T-die extrusion molding apparatus or an inflation molding apparatus can be used. The heating temperature during molding (temperature of the resin composition during molding) is not particularly limited as long as it is at least a temperature at which the resin composition can melt. From the viewpoint of ease of molding and prevention of thermal decomposition of components in the resin composition, it is preferable that the temperature is (Y+20)°C or higher and (Y+60)°C or lower, where Y (°C) is the melting point of the thermoplastic resin used as the raw material. If the resin composition contains multiple types of thermoplastic resins, the melting point of the thermoplastic resin with the highest melting point among those multiple types of thermoplastic resins is defined as Y. The cooling of the molded body may be achieved by natural cooling, where the molded body is left in a room temperature environment, or by forced rapid cooling using a cooling means.

[0085] In the stretching step, an unstretched sheet containing a thermoplastic resin and inorganic particles is stretched. Stretching causes interfacial delamination between the thermoplastic resin and inorganic particles in the unstretched sheet, resulting in the thermoplastic resin becoming porous. The porous thermoplastic resin, while surrounding the multiple voids scattered on its surface and within, forms a continuous network structure in both the surface direction and the thickness direction of the sheet. Thus, a film sheet having the network structure is obtained.

[0086] The stretching of the unstretched sheet in the stretching process may be uniaxial or biaxial, but biaxial stretching is preferred. Uniaxial or biaxial stretching of the unstretched sheet can be carried out using conventionally known methods. For example, it can be carried out using the roll method or the tenter method. Film sheets manufactured by biaxial stretching exhibit less anisotropy in the fibrous portion and superior mechanical properties compared to film sheets manufactured by uniaxial stretching. Film sheets 1 and 2 in Figures 1 and 2 were manufactured by biaxial stretching, while film sheet 3 in Figure 3 was manufactured by uniaxial stretching.

[0087] The following describes the case in which an unstretched sheet is biaxially stretched. In this case, the method for manufacturing a film sheet of the present invention can be carried out by a sequential biaxial stretching method. One embodiment of the method for manufacturing a film sheet of the present invention includes the step of applying a first stretch in one direction to an unstretched sheet containing a thermoplastic resin and a plurality of inorganic particles, and then applying a second stretch in a direction intersecting the first stretch.

[0088] Typically, in the first stretching, a long, continuous strip of sheet to be stretched (unstretched sheet) is conveyed in one direction and introduced into a group of rolls, where it is stretched between two rolls with different peripheral speeds in that direction. The aforementioned direction is typically the conveying direction MD of the sheet to be stretched. The first stretching stretches the sheet to be stretched in the MD direction. In the subsequent second stretching, the sheet that has undergone the first stretching is introduced into a tenter (lateral stretcher) while both ends are gripped with clips, and it is stretched in a direction intersecting the aforementioned direction (MD). The stretching direction of the second stretching is typically a direction (CD) perpendicular to the aforementioned direction (MD). After the first stretching and before the second stretching, the sheet to be stretched may be cooled.

[0089] The first stretching is preferably performed while heating the sheet to be stretched (unstretched sheet). The method of heating the sheet to be stretched in the first stretching is not particularly limited and includes, for example, a method of bringing the sheet to be stretched into contact with heated rolls such as the roll group, or a method of heating the sheet to be stretched with hot air or a heater. In the first stretching process, the heating temperature of the sheet to be stretched is preferably (Y1-100)°C or higher and (Y1-10)°C or lower, and more preferably (Y1-80)°C or higher and (Y1-40)°C or lower, where Y1 (°C) is the melting point of the thermoplastic resin used as the raw material. If the sheet to be stretched contains multiple types of thermoplastic resins, the melting point of the thermoplastic resin with the highest melting point among those multiple types of thermoplastic resins is defined as Y1.

[0090] The stretching ratio in the first stretching is preferably 1.2 times or more, more preferably 1.5 times or more, and even more preferably 2 times or more, from the viewpoint of making the second stretching uniform. Furthermore, from the viewpoint of preventing unintended tearing after stretching, the stretching ratio is preferably 9 times or less, more preferably 7 times or less, and even more preferably 5 times or less. By setting the stretching ratio in the first stretching to the specified range, it becomes easier to obtain a film sheet in which the void occupancy rate is within the specified range.

[0091] The stretching speed of the sheet to be stretched in the first stretching is preferably 100 mm / second or more and 1000 m / second or less, more preferably 300 mm / second or more and 100 m / second or less. By setting the stretching speed in the first stretching to the above-mentioned specific range, it becomes easier to obtain a film sheet in which the resin occupancy rate is within the above-mentioned specific range.

[0092] The second stretching is preferably performed while heating the sheet to be stretched (unstretched sheet). The method of heating the sheet to be stretched during the second stretching is not particularly limited, and examples include heating the sheet to be stretched with hot air or a heater. In the second stretching process, the heating temperature of the sheet to be stretched is preferably (Y1-80)°C or higher and (Y1-10)°C or lower, and more preferably (Y1-70)°C or higher and (Y1-40)°C or lower, where Y1 (°C) is the melting point of the thermoplastic resin used as the raw material. If the sheet to be stretched contains multiple types of thermoplastic resins, the melting point of the thermoplastic resin with the highest melting point among those multiple types of thermoplastic resins is defined as Y1.

[0093] The stretching ratio in the second stretching is preferably 1.2 times or more, more preferably 1.5 times or more, and even more preferably 2 times or more, from the viewpoint of making the thickness and basis weight after stretching as uniform as possible. Furthermore, from the viewpoint of preventing unintended tearing after stretching, the stretching ratio is preferably 9 times or less, more preferably 7 times or less, and even more preferably 5 times or less. By setting the stretching ratio in the second stretching to the specified range, it becomes easier to obtain a film sheet in which the void occupancy rate falls within the specified range.

[0094] The stretching speed of the sheet to be stretched in the second stretching is preferably 10 mm / second or more and 10 m / second or less, more preferably 50 mm / second or more and 5 m / second or less. By setting the stretching speed in the second stretching to the above specific range, it becomes easier to obtain a film sheet with a low degree of orientation.

[0095] Although the present invention has been described above based on its preferred embodiments, the present invention is not limited in any way to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. With regard to the embodiments of the present invention described above, the following additional information is disclosed.

[0096] <1> It is a film sheet, It contains thermoplastic resins other than acrylic polymers and multiple inorganic particles, The thermoplastic resin has a fibrous portion and a non-fibrous portion, A film sheet in which, among the plurality of inorganic particles, exposed inorganic particles having a portion exposed from the thermoplastic resin are present at the periphery of a plurality of voids where the thermoplastic resin is absent. <2> The fibrous portion is a portion that extends in one direction and whose maximum width in the direction perpendicular to the direction of extension is shorter than the length in the direction of extension. <1> The film sheet described above. <3> The width of the fibrous portion is 0.001 μm or more and 10 μm or less, preferably 0.01 μm or more and 5 μm or less, more preferably 0.05 μm or more and 2 μm or less. <1> or <2> The film sheet described above. <4> The fibrous portion has an elongated portion, and the ratio of the length to the width in the extending direction of the elongated portion is 0.5 or more and 50 or less, preferably 1 or more and 40 or less, more preferably 2 or more and 30 or less, as length / width. <1> ~ <3> A film sheet as described in any one of the following: <5> The non-fibrous portion is the portion in which, in the observation field obtained by magnifying the surface of the film sheet 5000 times with a scanning electron microscope, the ratio of the maximum extension length to the minimum extension length is 0.3 or more and 3 or less as maximum extension length / minimum extension length, preferably 0.5 or more and 2 or less, more preferably 0.7 or more and 1.5 or less. <1> ~ <4> A film sheet as described in any one of the following:

[0097] <6> The inorganic particles have a function, In the observation field obtained by magnifying the surface of the film sheet 5000 times with a scanning electron microscope, the resin occupancy rate, which is the ratio of the total area of ​​the thermoplastic resin to the area of ​​the observation field, is greater than 0% and 80% or less, preferably 5% or more and 70% or less, more preferably 10% or more and 60% or less. <1> ~ <5> A film sheet as described in any one of the following: <7> The function includes a deodorizing function, <6> The film sheet described above.

[0098] <8> The film sheet has multiple voids scattered on its surface and inside, The thermoplastic resin has a network structure, The network structure is such that the thermoplastic resin surrounds the plurality of voids and is continuous in both the surface direction and the thickness direction of the film sheet. <1> ~ <7> A film sheet as described in any one of the following: <9> The network structure has a plurality of fibrous portions, and the width of each fibrous portion is 0.001 μm or more and 10 μm or less. The plurality of inorganic particles include non-exposed inorganic particles, The air permeability of the film sheet is 0 seconds / 100 mL or more and 20,000 seconds / 100 mL or less. <8> The film sheet described above.

[0099] <10> In the observation field obtained by magnifying the surface of the film sheet 5000 times with a scanning electron microscope, the degree of orientation of the plurality of fibrous portions, as measured by the following method, is 0.3 or more and 3 or less, preferably 0.5 or more and 2 or less, more preferably 0.7 or more and 1.5 or less, <1> ~ <9> A film sheet as described in any one of the following: <Method for measuring the degree of orientation of fibrous parts> In the image corresponding to the observation field, a square with a side length of 15 μm is created such that one side of the square coincides with the machine direction during manufacturing of the film sheet to be measured or a direction perpendicular to the machine direction. The number of fibrous portions that cross both of the top and bottom sides of the square is defined as the top and bottom fiber count, and the number of fibrous portions that cross both of the left and right sides of the square is defined as the left and right fiber count. The ratio of the left and right fiber count to the top and bottom fiber count is calculated, and this ratio is defined as the degree of orientation of the fibrous portions of the film sheet to be measured. <11> The fibrous portions do not have fusion points or entanglement points, <1> ~ <10> A film sheet as described in any one of the following: <12> The plurality of fibrous portions, when considering a single fibrous portion, have portions in which the ratio of the particle diameter of inorganic particles on the fibrous portion to the width in the direction perpendicular to the extension direction of the fibrous portion (ratio of inorganic particle diameter / fiber width) is 0.01 or more and 1000 or less, preferably 0.1 or more and 500 or less, more preferably 0.2 or more and 300 or less. <1> ~ <11> A film sheet as described in any one of the following: <13> The plurality of fibrous portions, when considering a single fibrous portion, have portions in which the width in the direction perpendicular to the extension direction of the fibrous portion is smaller than the particle diameter of the inorganic particles, <1> ~ <12> A film sheet as described in any one of the following: <14> In the observation field obtained by magnifying the surface of the film sheet 5000 times with a scanning electron microscope, at least a portion of the plurality of voids has a ratio of the length in the long axis direction to the length in the short axis direction of the void, which is 0.3 or more and 3 or less, preferably 0.5 or more and 2 or less, more preferably 0.7 or more and 1.5 or less. <1> ~ <13> A film sheet as described in any one of the following: <15> In the field of view obtained by magnifying the surface of the film sheet 5000 times with a scanning electron microscope, the void located on the surface of the film sheet and the fibrous portion located inside the film sheet overlap in the thickness direction of the film sheet, <1> ~ <14> A film sheet as described in any one of the following: <16> In the field of view obtained by magnifying the surface of the film sheet 5000 times with a scanning electron microscope, the void located on the surface of the film sheet and the non-fibrous portion located inside the film sheet overlap in the thickness direction of the film sheet, <1> ~ <15> A film sheet as described in any one of the following:

[0100] <17> The thermoplastic resin contains a polyolefin resin, The content of the polyolefin resin in the thermoplastic resin is 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably 100% by mass, based on the total mass of the thermoplastic resin. <1> ~ <16> A film sheet as described in any one of the following:

[0101] <18> The content of the plurality of inorganic particles in the film sheet is 30% by mass or more and 50% by mass or less, preferably 35% by mass or more and 45% by mass or less, more preferably 40% by mass or more and 43% by mass or less, relative to the total mass of the film sheet. <1> ~ <17> A film sheet as described in any one of the following: <19> The plurality of inorganic particles include one or more selected from zinc oxide, calcium carbonate, aluminosilicate, and titanium oxide. <1> ~ <18> A film sheet as described in any one of the following: <20> The inorganic particles themselves are not covered by any other substance, <1> ~ <19> A film sheet as described in any one of the following: <21> The exposed surface of the exposed inorganic particles is configured to adsorb or react with odor components of the gas present inside the void when the film sheet is used, thereby causing the film sheet to exhibit a deodorizing effect against the gas. The exposed inorganic particles are preferably one or more selected from the group consisting of activated carbon, metal carbonate, metal oxide, aluminosilicate, diatomaceous earth, and silica. More preferably, the metal carbonate includes zinc oxide, and the metal oxide includes titanium oxide. <1> ~ <20> A film sheet as described in any one of the following:

[0102] <22> Furthermore, the above contains an acrylic polymer. <1> ~ <21> A film sheet as described in any one of the following: <23> The acrylic polymer comprises an alkyl methacrylate / alkyl acrylate copolymer, <22> The film sheet described above. <24> Furthermore, it contains one or more selected from silicone oil and hydrocarbon oil, Preferably, the silicone oil contains methylpolysiloxane, and the hydrocarbon oil contains polyester and / or stearate. More preferably, the polyester comprises one or more selected from the group consisting of those obtained from a polybasic acid and a polyhydric alcohol, and those obtained from a monobasic acid having 14 to 22 carbon atoms and a monohydric alcohol having 12 to 22 carbon atoms. <1> ~ <23> A film sheet as described in any one of the following: <25> The total content of the silicone oil and the hydrocarbon oil is 1% by mass or more and 20% by mass or less, preferably 2% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 5% by mass or less, relative to the total mass of the film sheet. <24> The film sheet described above. <26> The content of the β-nucleating agent in the film sheet is 0% by mass or more and 1.0% by mass or less, preferably 0.8% by mass or less, and more preferably 0.5% by mass or less, relative to the total mass of the film sheet. <1> ~ <25> A film sheet as described in any one of the following: <27> The fluorine-containing compound content in the film sheet is 0% by mass or more and 1.0% by mass or less, preferably 0% by mass or more and 0.8% by mass or less, more preferably 0% by mass or more and 0.5% by mass or less, relative to the total mass of the film sheet. <1> ~ <26> A film sheet as described in any one of the following:

[0103] <28> The air permeability of the film sheet is 0 seconds / 100 mL or more and 20,000 seconds / 100 mL or less, preferably 0 seconds / 100 mL or more and 6,000 seconds / 100 mL or less, more preferably 0 seconds / 100 mL or more and 5,000 seconds / 100 mL or less, preferably 50 seconds / 100 mL or more and 4,000 seconds / 100 mL or less. <1> ~ <27> A film sheet as described in any one of the following: <29> The air permeability of the film sheet is 10 seconds / 100 mL or more and 3000 seconds / 100 mL or less, preferably 50 seconds / 100 mL or more and 1000 seconds / 100 mL or less, more preferably 100 seconds / 100 mL or more and 800 seconds / 100 mL or less. <1> ~ <28> A film sheet as described in any one of the following: <30> The moisture permeability of the aforementioned film sheet is 2000 g / m². 2 ·15000g / m for 24 hours or more 2 • Less than 24 hours, as stated above <1> ~ <29> A film sheet as described in any one of the following: <31> The moisture permeability of the aforementioned film sheet is 2000 g / m². 2·20000g / m for 24 hours or more 2 • 24 hours or less, preferably 3000 g / m² 2 ·15000g / m for 24 hours or more 2 • 24 hours or less, more preferably 4000 g / m² 2 ·10000g / m for 24 hours or more 2 • Less than 24 hours, as stated above <1> ~ <30> A film sheet as described in any one of the following: <32> The moisture permeability of the aforementioned film sheet is 2000 g / m². 2 ·15000g / m for 24 hours or more 2 • 24 hours or less, preferably 3000 g / m² 2 ·10000g / m for 24 hours or more 2 • Less than 24 hours, as stated above <1> ~ <31> A film sheet as described in any one of the following: <33> The water pressure resistance of the film sheet is 10,000 mmAq or more and 100,000 mmAq or less, preferably 15,000 mmAq or more and 80,000 mmAq or less, more preferably 20,000 mmAq or more and 50,000 mmAq or less. <1> ~ <32> A film sheet as described in any one of the following: <34> The through holes that penetrate the film sheet in the thickness direction are only those through holes whose maximum span length in a plan view is greater than 0 μm and less than or equal to 100 μm. <1> ~ <33> A film sheet as described in any one of the following: <35> The thickness of the film sheet under a load of 0.8 kPa is greater than 0 μm and less than or equal to 100 μm. <1> ~ <34> A film sheet as described in any one of the following: <36> The above-mentioned sheets are for moisture permeability, clothing, heat shielding, or agricultural use. <1> ~ <35> A film sheet as described in any one of the following: <37> The aforementioned film sheet is a single sheet, <1> ~ <36> A film sheet as described in any one of the following:

[0104] <38> The aforementioned <1> ~ <37> A sheet article having a laminated structure of a film sheet described in any one of the following, and another sheet other than the film sheet, Preferably, the other sheet is arranged on one side of the film sheet, and the other side of the film sheet is exposed. Preferably, a sheet article in which the other sheet is a woven fabric. <39> A wearable article containing a film sheet, The aforementioned film sheet comprises a thermoplastic resin and a plurality of inorganic particles. In the aforementioned film sheet, a plurality of voids where the thermoplastic resin is absent extend through the thermoplastic resin, Of the plurality of inorganic particles, exposed inorganic particles having a portion exposed from the thermoplastic resin are present at the periphery of the plurality of voids. The aforementioned wearable article is selected from the group consisting of clothing, shoes, hats, and articles used to absorb bodily fluids discharged from the human body.

[0105] <40> It contains thermoplastic resins other than acrylic polymers and multiple inorganic particles, The thermoplastic resin has a fibrous portion and a non-fibrous portion, A method for manufacturing a film sheet, wherein exposed inorganic particles, among the plurality of inorganic particles, which have a portion exposed from the thermoplastic resin, are present at the periphery of a plurality of voids where the thermoplastic resin is absent, A method for manufacturing a film sheet, comprising the steps of first stretching an unstretched sheet containing a thermoplastic resin other than an acrylic polymer and a plurality of inorganic particles in one direction, and then stretching it in a direction intersecting the first direction. <41> The aforementioned <1> ~ <37> A method for manufacturing a film sheet according to any one of the following: A method for manufacturing a film sheet, comprising the steps of first stretching an unstretched sheet containing a thermoplastic resin and a plurality of inorganic particles in one direction, and then stretching it in a direction intersecting the first direction. <42> The stretching ratio in the first stretching and the stretching ratio in the second stretching are, respectively, 1.2 times or more and 9 times or less, preferably 1.5 times or more and 7 times or less, more preferably 2 times or more and 5 times or less. <40> or <41> A method for manufacturing a film sheet as described above. [Examples]

[0106] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to such examples.

[0107] [Examples 1-21 and Comparative Example 1: Manufacturing of Film Sheets] As thermoplastic resins other than acrylic polymers, resin compositions A to V with the compositions shown in Tables 1 and 2 below were manufactured. Specifically, resin compositions A to V were manufactured by heating and kneading raw materials containing thermoplastic resin and inorganic particles using a twin-screw extruder. Next, resin compositions A to V were molded into sheets using a T-die extrusion molding apparatus to obtain molded bodies, and these molded bodies were cooled to produce unstretched sheets. Next, the unstretched sheets were subjected to a first stretch in one direction, and then a second stretch in a direction perpendicular to the first stretch to produce the target film sheet. In the first stretch, the stretching ratio was as shown in Tables 3 and 4 below, the heating temperature was 120°C, and the stretching speed was 300 mm / second. In the second stretch, the stretching ratio was as shown in Table 3 below, the heating temperature was 120°C, and the stretching speed was 50 mm / second. Details of the raw materials used in the manufacture of the film sheet are as follows. β-nucleating agents and fluorine-containing compounds were not used.

[0108] Thermoplastic resin a: Homo PP (melting point: 160℃, MFR: 0.5g / min, density: 0.9g / cm³) 3 ), manufactured by Nippon Polypropylene Co., Ltd. "EA9" • Thermoplastic resin bB: Homo PP (melting point: 160℃, MFR: 24g / min, density: 0.9g / cm³) 3 ), manufactured by Nippon Polypropylene Co., Ltd. "FY6" • Thermoplastic resin c: Homo PP (melting point: 160℃, MFR: 11g / min, density: 0.9g / cm³)3 ), "MA3" manufactured by Nippon Polypropylene Co., Ltd. • Thermoplastic resin d: Random PP (propylene-ethylene random copolymer, melting point: 140℃, MFR: 2.4g / min, density: 0.9g / cm³) 3 ), "E-330GV" manufactured by Prime Polymer Co., Ltd. • Thermoplastic resin e: LLDPE (melting point: 120℃, MFR: 2.4g / min, density: 0.9g / cm³) 3 ), "Ultrasex 2520F" manufactured by Nippon Polypropylene Co., Ltd. • Thermoplastic resin f: Random PP (propylene-ethylene random copolymer, melting point: 140℃, MFR: 6.2g / min, density: 0.9g / cm³) 3 ), "F730NV" manufactured by Prime Polymer Co., Ltd. • Thermoplastic resin g: Ethylene-1-butene copolymer (melting point 44℃, MFR: 4g / min, density: 0.864g / cm³) 3 ), Non-commercial product (manufactured using a metallocene catalyst) • Thermoplastic resin h: LLDPE (melting point: 116℃, MFR: 5.5g / min, density: 0.924g / cm³) 3 ), Non-commercial product (manufactured using a metallocene catalyst) • Thermoplastic resin i: Polyethylene (molecular weight: 1.15 million g / mol), manufactured by Mitsui Chemicals, Inc., "Hyzex Million 145M"

[0109] All inorganic particles used were those that were not coated with any other material. • Inorganic particles j: Zinc oxide (average particle size 25 nm), manufactured by Teika Co., Ltd. "MZY-510M3S" Inorganic particles k: Calcium carbonate (average particle size 0.15 μm), manufactured by Shiraishi Kogyo Co., Ltd. "Brillant-1500" Inorganic particles l: Calcium carbonate (average particle size 1.8 μm), manufactured by Sankyo Flour Milling Co., Ltd., "Escalon 2000" • Inorganic particles m: Heavy calcium carbonate (average particle size 1.8 μm), manufactured by Toyo Fine Chemical Co., Ltd. "Whiten P30" • Inorganic particles n: Aluminosilicate (average particle size 0.8 μm), manufactured by Mizusawa Chemical Industries, Ltd. "Mizukasieves Y-500" • Inorganic particles: Aluminosilicate (average particle size 4 μm), manufactured by Mizusawa Chemical Industries, Ltd. "Mizukanaito HP"

[0110] • Acrylic polymer: Alkyl methacrylate / alkyl acrylate copolymer, manufactured by Mitsubishi Chemical Corporation as "Metablen P-1050" • Silicone oil: Methylpolysiloxane, manufactured by Shin-Etsu Chemical Co., Ltd. "KF96-1000CS" • Hydrocarbon oil p: A mixture of polyester obtained from a polybasic acid and a polyhydric alcohol, and polyester obtained from a monobasic acid with 14-22 carbon atoms and a monohydric alcohol with 12-22 carbon atoms. • Hydrocarbon oil q: Stearic acid, manufactured by Kao Corporation in "Lunaq S70V" • Hydrocarbon oil r: Palm oil (hyperhydrogenated triglycerides. Of the constituent fatty acids, saturated fatty acids with 14 carbon atoms account for 1% by mass, saturated fatty acids with 16 carbon atoms account for 42% by mass, saturated fatty acids with 18 carbon atoms account for 57% by mass, and do not contain fatty acids with unsaturated bonds or hydroxyl groups.) • Hydrocarbon oil s: Zinc stearate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. ("Zinc Stearate")

[0111] [Evaluation Test] The following evaluation items were assessed for each example and comparative example film sheet using the method described above. The results are shown in sections 3 and 4 below. For the film sheets of Examples 1-4 and 18, the 5000x observation field of view of one surface of the film sheet is shown in Figures 2 and 7-10. Figure 2 is Example 1, Figure 7 is Example 2, Figure 8 is Example 3, Figure 9 is Example 4, and Figure 10 is Example 18. In all examples and comparative examples, the film sheet had only the specified through-holes. (Evaluation criteria) ·Resin occupancy (%) • Presence or absence of exposed inorganic particles at the periphery of the void • Presence or absence of network structure • Presence or absence of fibrous parts • Presence or absence of non-fibrous parts • The ratio of the length to the width of the elongated portion of the fibrous part in the direction of extension (referred to as "length / width of the elongated portion" in Tables 3 and 4 below) • The ratio of the maximum and minimum extension length of the non-fibrous portion in the 5000x observation field (referred to as "maximum extension length of the portion without fibrous material / minimum extension length" in Tables 3 and 4 below). • Ratio of inorganic particle diameter to fiber width ("Inorganic particle diameter" corresponds to the "particle diameter (μm) of inorganic particles resting on the fibrous portion" in Tables 3 and 4 below. "Fiber width" corresponds to the "width (μm) of the fibrous portion" in Tables 3 and 4 below. The former / latter is the ratio of inorganic particle diameter to fiber width.) • Degree of orientation of the fibrous portion (referred to as "degree of orientation" in Tables 3 and 4 below) • Whether or not there is overlap between the surface voids and the internal fibrous portion in the 5000x observation field (referred to as "presence or absence of overlap between voids and fibrous portion" in Tables 3 and 4 below) • Whether or not there is overlap between the surface voids and the internal non-fibrous portion in the 5000x observation field (referred to as "presence or absence of overlap between voids and non-fibrous portion" in Tables 3 and 4 below) • Presence or absence of fusion points and entanglement points • Length of the void in the long axis direction / Length in the short axis direction • Air permeability (seconds / 100mL) ·Moisture permeability (g / m 2 (24 hours) • Water pressure resistance (mmAq) Thickness (μm) ·Basic weight (g / m 2 )

[0112] [Table 1]

[0113] [Table 2]

[0114] [Table 3]

[0115] [Table 4]

[0116] For a film sheet to have excellent waterproofing properties, a high water pressure resistance value is desirable. As shown in Tables 3 and 4, the film sheets of each example have exposed inorganic particles at the periphery of the voids. Therefore, it can be seen that the film sheets of each example have superior waterproofing properties compared to Comparative Example 1, which has a water pressure resistance of 20,000 mmAq or higher and does not have exposed inorganic particles at the periphery. [Explanation of Symbols]

[0117] 1-3 Film Sheets 5 Cavity 5S Peripheral edge of the void 6. Network Structure 7. Fibrous portion 8 Non-fibrous portion

Claims

1. It is a film sheet, It contains thermoplastic resins other than acrylic polymers and multiple inorganic particles, The thermoplastic resin has a fibrous portion and a non-fibrous portion, A film sheet in which, among the plurality of inorganic particles, exposed inorganic particles having a portion exposed from the thermoplastic resin are present at the periphery of a plurality of voids where the thermoplastic resin is absent.

2. The inorganic particles have a function, The film sheet according to claim 1, wherein, in the observation field obtained by magnifying the surface of the film sheet 5,000 times with a scanning electron microscope, the resin occupancy rate, which is the ratio of the total area of ​​the thermoplastic resin to the area of ​​the observation field, is greater than 0% and less than or equal to 80%.

3. The film sheet has multiple voids scattered on its surface and inside, The thermoplastic resin has a network structure, The film sheet according to claim 2, wherein the network structure is continuous in both the surface direction and the thickness direction of the film sheet while surrounding the plurality of voids.

4. The film sheet according to claim 3, wherein, in the observation field, the degree of orientation of the plurality of fibrous portions, as measured by the method described below, is 0.3 or more and 3 or less. <Method for measuring the degree of orientation of fibrous parts> In the image corresponding to the aforementioned observation field, a square with a side length of 15 μm is created such that one side of the square coincides with the machine direction during the manufacturing of the film sheet to be measured, or a direction perpendicular to the machine direction. The number of fibrous portions that cross both the top and bottom sides of the square is defined as the number of top and bottom fibers, and the number of fibrous portions that cross both the left and right sides of the square is defined as the number of left and right fibers. The ratio of the number of left and right fibers to the number of top and bottom fibers is calculated, and this ratio is defined as the degree of orientation of the fibrous portions of the film sheet being measured.

5. The film sheet according to claim 1, further containing an acrylic polymer.

6. The moisture permeability of the aforementioned film sheet is 2000 g / m². ２ ・15000g / m for 24 hours or more ２ - A film sheet according to claim 1 or 2, wherein the duration is 24 hours or less.

7. The film sheet according to claim 1 or 2, wherein the fibrous portion extends in one direction and the maximum width in the direction perpendicular to the direction of extension is shorter than the length in the direction of extension.

8. Wearable articles containing film sheets, The aforementioned film sheet contains a thermoplastic resin other than an acrylic polymer and a plurality of inorganic particles. In the aforementioned film sheet, a plurality of voids where the thermoplastic resin is absent extend through the thermoplastic resin, Of the plurality of inorganic particles, exposed inorganic particles having a portion exposed from the thermoplastic resin are present at the periphery of the plurality of voids. The aforementioned wearable article is selected from the group consisting of clothing, shoes, hats, and articles used to absorb bodily fluids discharged from the human body.

9. It contains thermoplastic resins other than acrylic polymers and multiple inorganic particles, The thermoplastic resin has a fibrous portion and a non-fibrous portion, A method for manufacturing a film sheet, wherein exposed inorganic particles, among the plurality of inorganic particles, which have a portion exposed from the thermoplastic resin, are present at the periphery of a plurality of voids where the thermoplastic resin is absent, A method for manufacturing a film sheet, comprising the steps of first stretching an unstretched sheet containing a thermoplastic resin other than an acrylic polymer and a plurality of inorganic particles in one direction, and then stretching it in a direction intersecting the first direction.

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