Mask Sheet

Abstract

To provide a mask sheet which is capable of being a smaller shape in any size by being wound, and seldom deforms even when it is made smaller.SOLUTION: A mask sheet 10 comprises a first face 1S which is a face contacting the skin of a user, and a second face 1R which is a face opposed to the first face 1S. The outermost face of at least one of the first face 1S and the second face 1R is provided with a plurality of protruding parts 1 protruding outward in the thickness direction, and recessed parts 2 sandwiched by the plurality of protruding parts 1. The recessed parts 2 are continuously arranged in one direction X in a plan view.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mask sheet. [Background technology]

[0002] In recent years, with the spread of infectious diseases, people are increasingly wearing masks that cover their mouths and noses for long periods of time. Some of these masks are foldable, and various technologies have been proposed to make them foldable. For example, U.S. Patent No. 5,399,633 describes a personal respiratory protection device having a main body with a first portion, a second portion separated from the first portion by a first boundary line, and a third portion separated from the second portion by a second boundary line. The personal respiratory protection device can be folded into a substantially flat configuration along a bisection fold extending through the first portion, the second portion, and the third portion. Patent Document 2 describes a dust mask having a nonwoven fabric sheet as a mask base material with embossed lines. This dust mask is foldable by folding the mask vertically along the embossed lines toward the inside of the mask.

[0003] [Patent Document 1] Special Publication No. 2002-537009 [Patent Document 2] JP 2006-218079 A Summary of the Invention [Problem to be solved by the invention]

[0004] When using one mask for a long time, there are occasions when the mask is removed and then worn again during meals, etc. When the removed mask is temporarily placed on a desk or put in a pocket, it is often desirable from a hygienic standpoint to fold the mask neatly so that the surface in contact with the skin does not come into contact with germs and become contaminated. In addition to folding the surface in contact with the skin inward, the surface that does not come into contact with the skin may be folded inward to prevent the scattering of particles such as pollen. However, when a conventional mask is folded, a fold line is generated at the folded portion, and when the mask is opened and unfolded again, the surface covering the mouth and nose may not return to its original state and may become deformed. In other words, the restoration of the mask after folding is poor, and not only the appearance but also the performance of maintaining primary hygiene may deteriorate. Furthermore, even in the case of foldable masks as described in Patent Documents 1 and 2, in order to maintain the performance of the mask, it can only be folded into a designed shape. In other words, the user cannot fold the mask to any small size while maintaining hygienic performance. Conventional masks still had some room for improvement in terms of being able to be folded and made small while still taking hygiene into consideration.

[0005] In view of the above problems, the present invention relates to a mask sheet that can be rolled up to a desired size, and even when rolled up, is unlikely to deform when reused and has good restorability. The present invention also relates to a mask having the mask sheet. Furthermore, the present invention relates to a suitable method for using the mask sheet and the mask. [Means for solving the problem]

[0006] The present invention relates to a first surface that comes into contact with the user's skin. 1 The surface and the 1 The opposite face of the 2 a surface; 1 Surface and the above 2The sheet for masks has, on one or both outermost surfaces, a plurality of convex portions protruding outward in the thickness direction and concave portions sandwiched between the plurality of convex portions, the concave portions being continuously arranged in one direction in a plan view. Effect of the Invention

[0007] The mask sheet and mask of the present invention can be rolled up to a size of any desired size, and even if it is rolled up, it is unlikely to deform when reused and has good recovery properties. Furthermore, according to the method for using a mask sheet and the method for using a mask of the present invention, the mask sheet and the mask can be used suitably. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating a mask sheet according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a schematic example of convex portions and concave portions present on the outermost surface of the mask sheet of the present invention. [Diagram 3] FIG. 2 is a side view showing a schematic diagram of the mask sheet shown in FIG. 1 in a rolled up state. [Figure 4] FIG. 2 is a front view showing a schematic view of the mask sheet shown in FIG. 1 rolled up and placed in a pocket. [Diagram 5] FIG. 2 is a plan view showing another example of the convex portions and concave portions present on the outermost surface of the mask sheet of the present invention. [Figure 6] An explanatory diagram showing the definition of "continuous in one direction" for a recess. (A) and (B) show an example where a given recess corresponds to "continuous in one direction". (C) and (D) show an example where a given recess does not correspond to "continuous in one direction". [Figure 7] FIG. 1 is a cross-sectional view illustrating a schematic diagram of one embodiment of a mask sheet according to the present invention. [Figure 8] FIG. 2(a) is a perspective view showing a state in which the mask sheet of the present invention is worn, and FIG. 2(b) is a perspective view showing the mask sheet shown in (a) as seen from the inside. [Figure 9] FIG. 1 is a perspective view showing a method for using the mask sheet of the present invention as a filter sheet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A preferred embodiment of the mask sheet of the present invention will be described with reference to the drawings. The mask sheet of the present invention is a material used for a mask, and includes both the raw material before being applied to the mask and the material incorporated into the mask. In the present invention, unless otherwise specified, the direction corresponding to the top and bottom of the human body during use is referred to as the up-down direction, and the direction corresponding to the left and right of the human body is referred to as the left-right direction. In addition, a surface to which the up-down and left-right directions belong is referred to as a plane, and a direction perpendicular to the plane direction is referred to as a thickness direction.

[0010] The mask sheet of the present invention has a first side which is the side that contacts the skin of the user, and a second side which is the side opposite to the first side. On the outermost surface of one or both of the first and second sides, there are a plurality of convex portions protruding outward in the thickness direction, and a concave portion sandwiched between the plurality of convex portions. The mask 20 shown in FIG. 1 includes a pair of mask sheets 10, 10, which is a preferred embodiment of the mask sheet of the present invention. The pair of mask sheets 10, 10 of this embodiment are arranged with their first surfaces 1S facing each other. Each mask sheet 10 has a flat outermost surface of its second surface 1R, and has convex portions 1 and concave portions 2 on the outermost surface of its first surface 1S. As shown in FIG. 2, the concave portions 2 are arranged continuously in one direction in a plan view. In FIG. 2, the "one direction" in which the concave portions 2 are continuous is the short side direction X of the mask sheet 10, which has a longitudinal direction Y and a short side direction X perpendicular to the longitudinal direction Y. This short side direction X is the up-down direction in the mask 20 shown in FIG. 1. The mask sheet 10 shown in FIG. 2 has the convex portions 1 and concave portions 2 arranged in such a pattern over the entire sheet surface, and becomes a raw material (for example, a long roll) before being applied to the mask 20.

[0011] Since the outermost surface of one or both of the first surface 1S and the second surface 1R has projections and recesses 2 that are continuous in one direction, the recesses 2 become the starting points for folding the mask sheet 10 and the mask 20. This makes it easy to roll and fold the mask sheet 10 and the mask 20. That is, the mask can be folded into a small shape when not in use. In addition, stress is likely to concentrate in the continuous recesses 2, making the sheet 10 easy to bend. As a result, even when the sheet 10 for masks is folded small, the sheet 10 for masks is likely to bend preferentially at the recesses 2 rather than at other parts. As a result, the protrusions 1 are unlikely to be crushed by folding, and the performance of the sheet 10 for masks is likely to be maintained. In addition, preferential bending at the recesses 2 makes the sheet 10 for masks less likely to develop creases. In other words, the sheet 10 for masks is unlikely to deform when reused, and has good restorability.

[0012] The direction in which the recesses 2 are continuous is not limited to that shown in Fig. 2, and may be any direction in a plan view. For example, it may be the short-side direction X (the vertical direction of the mask 20) ​​or the long-side direction Y (the horizontal direction of the mask 20). However, from the viewpoint of being able to roll and fold the mask 20 into a smaller shape, as described below, the one direction is preferably the short-side direction X.

[0013] That is, as shown in FIG. 1, it is preferable that the recesses 2 are continuous in the up-down direction of the mask 20 (the short-side direction X of the mask sheet 10). The shape of the mask 20 is generally such that the length in the left-right direction is greater than the length in the up-down direction. Therefore, when the mask 20 is rolled in the left-right direction, the length (up-down direction) of the rod-shaped mask 20 becomes shorter than when it is rolled in the other direction. That is, by rolling in the left-right direction, the mask 20 can be folded into a small size. At this time, since there are recesses 2 that are continuous in the up-down direction, it becomes easy to fold the mask 20 in the left-right direction starting from the recesses 2. As a result, it is possible to roll and fold the mask 20 into a short rod shape.

[0014] The number of recesses 2 arranged continuously in one direction may be only one, or may be multiple, as shown in Figs. 1 and 2. When the mask sheet 10 has only one recess 2, the mask sheet 10 can be folded in half by bending the mask sheet 10 from one recess 2. On the other hand, when the mask sheet 10 has multiple recesses 2, the mask sheet 10 can be folded from multiple recesses 2 to roll into a rod shape as shown in Fig. 3. Furthermore, as shown in Fig. 4, the mask sheet 10 can be rolled up to any size and put in a pocket. In addition, the mask 20 having the mask sheet 10 can be folded with the first surface 1S facing inward, folded in half, and then rolled up, thereby avoiding contact between the first surface 1S and the second surface 1R. As a result, the first surface 1S that comes into contact with the user's skin can be kept hygienic. That is, from the viewpoint of enabling the sheet to be rolled and folded into a smaller shape, it is preferable that the recesses 2 are arranged in a plurality of stripes along a direction intersecting one direction. Moreover, it is preferable that such a plurality of stripes of recesses 2 continuous in one direction are arranged over the entire sheet surface of the mask sheet 10 as shown in Fig. 2. Furthermore, it is preferable that the recesses 2, 2 are arranged at equal intervals.

[0015] The continuously arranged recesses 2 may be continuous in one direction in a straight line as shown in Fig. 2, or may be continuous in one direction (first direction S1 or second direction S2) while meandering as shown in Fig. 5. In either form, the mask sheet 10 can be folded starting from the continuous recesses 2. However, from the viewpoint of making it easier to reduce the thickness of the mask sheet 10 when it is in a folded state, it is preferable that the recesses 2 are linear. The linear recesses 2 can be typically formed by providing the outermost surface with unevenness having a ridge-and-furrow structure as shown in Fig. 2. Therefore, from the viewpoint of forming the linear recesses 2, it is preferable that the protrusions 1 and the recesses 2 are unevenness having a ridge-and-furrow structure. The term "continuous in one direction" means that an approximation line obtained from a curve consisting of the path of a recess between multiple protrusions is in the region between the multiple protrusions. Here, the approximation line is in the direction along the arrangement direction of the multiple recesses. Nobu The approximation line is a straight line that Nobu The direction in which the wire stretches is the "one direction" shown above. For example, in the arrangement of convex portions 1 and concave portions 2 shown in FIG. 6(A), the approximate straight line obtained from the path 3 of the concave portions is the approximate straight line L1 shown in FIG. 6(B). Since the approximate straight line L1 is in the region between the convex portions 5 (shaded convex portions 1) on both sides of the path 3 of the concave portions, it can be said that the path 3 of the concave portions is continuous in one direction. On the other hand, the approximate straight line L2 shown in FIG. 6(D) is obtained from the path 4 of the concave portions shown in FIG. 6(C). However, since the approximate straight line L2 does not fall within the region between the convex portions 5 (shaded convex portions 1) on both sides of the path 4 of the concave portions, it does not fall under the "continuous in one direction" described above.

[0016] The recesses 2 may be arranged in a plurality of stripes along a plurality of directions in a plan view. For example, in the top surface of the mask sheet 10 shown in Fig. 5, a plurality of continuous recesses 2 are arranged in a direction intersecting the first direction S1 while meandering in a first direction S1, as a form different from that shown in Fig. 2, and a plurality of continuous recesses 2 are arranged in a direction intersecting the second direction S2 while meandering in a second direction S2 different from the first direction S1. Both the first direction S1 and the second direction S2 are directions intersecting the longitudinal direction Y and the lateral direction X of the mask sheet 10. In this embodiment, the protrusions 1 are arranged in a scattered manner. The recesses 2 between the scattered protrusions 1, 1 are connected to form grooves, and the recesses 2 are arranged in a mesh pattern. In this manner, the recesses 2 may all be connected to form one. However, even if the recesses 2 are connected to one another in a mesh pattern or the like, it is preferable that multiple recesses 2 that are continuous in one direction are arranged in parallel to each other, and the recesses 2 essentially function as multiple grooves. If the recesses 2 are essentially multiple grooves, it becomes possible to roll the mask sheet 10 into a rod shape, starting from each of the parallel grooves, and fold it small in multiple directions.

[0017] From the viewpoint of making the unevenness of the outermost surface of the mask sheet 10 clear, the height of the protrusions 1 (the distance that the protrusions 1 protrude outward in the thickness direction) is preferably 1 mm or more, more preferably 1.5 mm or more, and even more preferably 2 mm or more. From the viewpoint of making it possible to fold the sheet into a smaller shape, the height of the protrusions 1 is preferably 4 mm or less, more preferably 3.5 mm or less, and even more preferably 3 mm or less. The height of the protrusions 1 can be rephrased as the difference in height between the protrusions 1 and the recesses 2, or the depth of the recesses 2.

[0018] Since the recesses 2 are arranged continuously in one direction X, the protrusions 1 between adjacent recesses 2, 2 have a certain width in a direction perpendicular to the one direction X. From the viewpoint of creating a buckling starting point at the recesses 2 and making it easy to fold, the width of this protrusion 1 is preferably 1 mm or more, more preferably 1.5 mm or more, and even more preferably 2 mm or more. In addition, from the viewpoint of providing many recesses 2 and making it possible to roll and fold the mask sheet 10 into a small shape, the width of the protrusion 1 is preferably 6 mm or less, more preferably 5 mm or less, and even more preferably 4 mm or less. The width of the protrusion 1 can be rephrased as the distance between adjacent recesses 2, 2.

[0019] Next, the components of the mask sheet 10 of the present invention will be described.

[0020] The mask sheet 10 of the present invention may be composed of one sheet, or may be composed of a plurality of sheets laminated together. A specific example of a laminate of a plurality of sheets is a laminate of an elastic sheet and a textured sheet. In this case, the textured sheet is preferably composed of a filter layer (a layer made of fibers having an average fiber diameter of 3000 nm or less) and a spunbonded nonwoven fabric layer that protects the filter layer. By including a filter layer, or by having a sheet including a filter layer have a textured shape, the ability to capture fine particles in the air is extremely high, and flexibility is also increased. In addition, by including the ultrafine fibers in the filter layer, the density is increased, and the number of contact points between the fibers is increased, which can improve the adhesion of the welded parts described below. From this viewpoint, the average fiber diameter of the constituent fibers of the filter layer is more preferably equal to or less than 2000 nm, and further preferably equal to or less than 1000 nm. In order to ensure adequate breathability and allow the user of the mask sheet 10 to breathe easily, the average fiber diameter of the fibers constituting the filter layer is preferably 50 nm or more, more preferably 100 nm or more, and even more preferably 200 nm or more.

[0021] The average fiber diameter of the constituent fibers of the filter layer can be measured by measuring the maximum diameter of the fiber cross section perpendicular to the fiber length direction using a scanning electron microscope (SEM). The specific procedure is as follows. After carefully peeling off the masking material to confirm how many layers are present, the layer with the smallest fiber diameter (the layer that functions as a filter) is taken as the fiber layer to be measured. From the two-dimensional image obtained by SEM observation, 500 fibers are randomly selected, excluding defects such as fiber clumps, fiber intersections, and polymer droplets, and the length of a line drawn perpendicular to the longitudinal direction of the fiber is directly read as the fiber diameter. From the frequency distribution (histogram) of the measured fiber diameters, the median fiber diameter with a cumulative frequency of 50% of the total is determined, and this is taken as the average fiber diameter of the fibers that make up the fiber layer to be measured.

[0022] As long as the mask sheet 10 has at least a concave-convex sheet having a convex portion 1 and a concave portion 2, the other sheet may be a concave-convex sheet or a flat sheet. Among them, the mask sheet 10 is preferably a laminate of a concave-convex sheet 11 having a convex portion 1 and a concave portion 2 and a flat sheet 12 having a flat shape, as shown in FIG. 7. When these are laminated one by one, the concave-convex sheet 11 side becomes a concave-convex surface 1A having the convex portion 1 and the concave portion 2 on the outermost surface, and the flat sheet 12 side becomes a flat surface 1B. That is, the mask sheet 10 as a whole has a structure similar to a shutter-type bath cover or a single-sided cardboard, and can be freely rolled up to any size at any location in the same way. Moreover, the flat sheet 12 acts on the concave-convex sheet 11 to maintain the shape of the sheet surface, so that the mask sheet 10 does not develop a crease, and the restorability is further improved.

[0023] When the flat sheet 12 is used as a constituent member of the mask sheet 10, the flat sheet 12 is preferably an elastic sheet. When an elastic sheet is used for the flat sheet 12, the unevenness can be suitably formed on the outermost surface of the mask sheet 10 in the following manner when manufacturing the mask sheet 10. For example, a part of a sheet that is a precursor of the uneven sheet 11 is attached to a stretched elastic sheet, and then the stretched state is released, whereby the precursor of the uneven sheet 11 shrinks and unevenness is formed. With such a configuration, a hollow portion is generated between the uneven sheet 11 and the flat sheet 12, and the bending stress when the mask is bent is reduced.

[0024] In this specification, "elastic" refers to a property in which, after applying force in one direction to the sheet and stretching it 50% (stretching it to 1.5 times its natural length before stretching), the stretch rate when the load is removed shrinks to 0% to 10% (1 to 1.1 times its natural length before stretching). In contrast, in this specification, "non-elastic" refers to a property in which the stretch rate exceeds 10% when a similar test is performed, or a property in which the sheet breaks when stretched 50%. According to this standard, it is possible to distinguish whether the sheet used as a component of the mask sheet 10 is an elastic sheet or a non-elastic sheet. Examples of the stretchable sheet include nonwoven fabrics containing elastic fibers as constituent fibers, composite materials of nonwoven fabrics made of nonelastic fibers and elastic bodies (e.g., elastic filaments), and cotton-mixed nonwoven fabrics of elastic fibers and nonelastic fibers. In measuring the "stretchability" described above, when the sheet to be measured is, for example, a flat sheet 12 and a concave-convex sheet 11 laminated thereon, the sheet 10 for sanitary masks is left in a natural state without external force and cut into 20 mm x 50 mm pieces using a single-edged blade (product number: FAS-10) manufactured by Feather Safety Razor Co., Ltd. Then, the joint at the interface between the flat sheet 12 and the concave-convex sheet 11 is cut using a razor, cutter, scissors, or the like to separate the flat sheet 12 and the concave-convex sheet 11, and each cut piece is stretched in the longitudinal direction to evaluate the "stretchability".

[0025] On the other hand, when the embossed sheet 11 is used as a component of the mask sheet 10, it is preferable that the embossed sheet 11 is a non-elastic sheet. By using a non-elastic sheet for the embossed sheet 11, it is easy to prevent the rolled up mask from unintentionally opening up.

[0026] The mask sheet 10 of the present invention can be used in a mask in various ways. For example, in the embodiment shown in Figures 1 and 8, not only the mask body but also the ear loops are made of the mask sheet 10, but instead, only the mask body may be made of the mask sheet 10, and the ear loops may be made of other materials, such as rubber strings or elastic nonwoven fabric. In any case, these embodiments are forms in which the mask body has the mask sheet 10 of the present invention. Alternatively, the mask sheet 10 of the present invention may be used as a filter sheet that is detachable from a mask body, as shown in Fig. 9. In this embodiment, the mask has a mask body and a filter sheet, and the filter sheet has the mask sheet 10 of the present invention. These masks use the mask sheet 10 of the present invention, and therefore can be rolled and folded starting from the recessed portion 2. EXAMPLES

[0027] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0028] Example 1 A mask sheet having a ridge-and-groove structure on the outermost surface was produced by laminating a concave-convex sheet and a flat sheet, as shown in Figures 2 and 7. The convex and concave portions of the ridge-and-groove structure were both linear. The height of the convex portions was 2.5 mm, and the width of the convex portions was 3 mm. The mask sheet was cut and joined so that the extension direction of the convex and concave parts coincided with the vertical direction of the mask, and a mask sample was produced in which the first surface that comes into contact with the user's skin is an uneven surface, as shown in Figure 1. This was used as the mask sample of Example 1. By folding starting from the multiple recesses, the mask sample of Example 1 was rolled up in the left-right direction into a rod shape as shown in Fig. 3, and the left-right length of the mask sample in a plan view was reduced to 1 / 6. The rolled mask sample was left to stand for 10 seconds without applying external force, and then the left-right length of the mask sample in a plan view was measured.

[0029] Comparative Example 1 A rectangular pleated mask (product name: Azfine Fit Surgical Mask, manufactured by AzScience Corporation) was used as the mask sample of Comparative Example 1. The mask sample of Comparative Example 1 was rolled up and down into a rod shape by folding from the pleats, and the vertical length of the mask sample in plan view was reduced to 1 / 6. The rolled mask sample was left to stand for 10 seconds without applying any external force, and then the vertical length of the mask sample in plan view was measured.

[0030] (Calculation of state maintenance rate) The state maintenance rate was calculated by dividing the length of the mask sample in the rolled state in the rolled direction by the length of the mask sample in the rolled direction after leaving it for 10 seconds for each of the mask samples of Example 1 and Comparative Example 1. Note that the "rolled direction" refers to the direction in which the mask sample was rolled, and in the mask sample of Example 1, the left-right direction corresponds to the rolled direction, and in the mask sample of Comparative Example 1, the up-down direction corresponds to the rolled direction. The closer the state retention rate is to 100%, the easier it is for the mask sample to maintain its rolled state. The results are shown in Table 1.

[0031] [Table 1]

[0032] As shown in Table 1, in the mask sample of Example 1, even when left undisturbed for 10 seconds in a rolled state, the length in the rolled direction in a plan view did not change, and the state maintenance rate was 100%. In other words, the state maintenance rate was better than that of the mask sample of Comparative Example 1, whose length in the rolled direction increased when left undisturbed for 10 seconds in a rolled state. That is, the mask sample of Example 1 could be reduced in size to 1 / 6 of its original length and maintained in that reduced state. [Explanation of symbols]

[0033] 1 Convex part 2 Recess 3,4 The journey through the recesses 5. The convex parts on both sides of the concave path 10 Mask Sheets 11 Textured sheet 12 Flat Sheet 1A Uneven surface 1B Flat surface 1S 1st page 1R 2nd page 20 Mask L1,L2 approximate straight line S1 1st direction S2 2nd direction X Short direction Y Longitudinal direction

Claims

1. The mask has a first surface that contacts the skin of a user and a second surface that is opposite to the first surface, On an outermost surface of one or both of the first surface and the second surface, there are a plurality of convex portions protruding outward in a thickness direction and a plurality of concave portions sandwiched between the convex portions, The mask sheet, in which the recesses are continuously arranged in one direction in a plan view, is a laminate of a concave-convex sheet having the convex portions and the recesses and a flat sheet having a flat shape, the flat sheet being an elastic sheet, A mask having a mask body constituted by the mask sheet.

2. A mask as described in claim 1, wherein ear loops are formed from the mask sheet.

3. 3. The mask according to claim 1, wherein the recesses are arranged in a plurality of stripes along a direction intersecting the one direction in a plan view, and the mask is foldable to an arbitrary size.

4. A method for using a mask, comprising rolling and folding the mask according to any one of claims 1 to 3, starting from the recess.

5. The mask has a first surface that contacts the skin of a user and a second surface that is opposite to the first surface, On an outermost surface of one or both of the first surface and the second surface, there are a plurality of convex portions protruding outward in a thickness direction and a plurality of concave portions sandwiched between the convex portions, the concave portions are continuously arranged in one direction in a plan view, the mask sheet being formed by laminating a concave-convex sheet having the convex portions and the concave portions and a flat sheet having a flat shape, The sheet for a mask, wherein the flat sheet is a stretchable sheet.

6. A mask sheet as described in claim 5, wherein the height of the convex portion is 3 mm or less.

7. The mask sheet according to claim 5 or 6, wherein the recesses are arranged in a plurality of stripes along a cross direction intersecting the one direction in a plan view, and the mask sheet is foldable to an arbitrary size.

8. A mask body and a filter sheet that is detachable from the mask body. A mask, comprising the filter sheet according to any one of claims 5 to 7.

9. A method for using the mask sheet according to any one of claims 5 to 7 as a filter sheet that is detachable from a mask body.

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