RU210758U1 - MASK SHEET - Google Patents

Abstract

A mask sheet is provided that provides both fine particle trapping capability and improved usability. The mask sheet has a first fibrous layer, which is a non-woven material made by electrospinning, and a second fibrous layer, provided on the side of one surface of the first fibrous layer, the second fibrous layer being a non-woven material, and the first fibrous layer is configured to capture small particles. The average diameter of the fibers constituting the fibers of the second fibrous layer is greater than the average diameter of the fibers constituting the fibers of the first fibrous layer. The average diameter of the fibers constituting the fibers of the first fibrous layer is 0.5 µm-0.8 µm. The basis weight of the first fibrous layer is 2.5 g/m2-15 g/m2. The ratio of the weight of the base of the second fibrous layer 12 to the weight of the base of the first fibrous layer is less than 8. The mask sheet 10 has a zone A corresponding to the mouth and is located in accordance with the position of the user's mouth in the plan view, and has a connected part connecting the fibrous layers and each other with friend. The mask sheet is used in the mask as a detachable filter sheet or as the main part of the mask. 13 w.p. f-ly, 9 ill., 1 tab.

Description

Field of technology to which the utility model belongs

[0001]

The present utility model relates to a mask sheet and a mask including the mask sheet.

Prior Art

[0002]

As a mask covering the mouth and nose of a wearer, a mask having a mask body formed from a sheet-like material such as a non-woven material is known. Examples of the effect of the mask include preventing the entry of dust, viruses, pollen, and the like from outside. Patent Literature 1 discloses a mask for obtaining such an effect, in which the main body of the mask is formed by a plurality of sheets of electret fibers. In addition, each of Patent Literature 2 and 3 discloses a mask provided with a layer of nanofibers in the main body of the mask.

Link List

Patent Literature

[0003]

Patent Literature 1: JP 2009-273726 A.

Patent Literature 2: JP 2015-196263 A.

Patent Literature 3: JP 2018-172806 A.

The essence of the utility model

Technical problem

[0004]

None of the masks described in Patent Literature 1-3 provide sufficient both fine particle trapping capability and usability enhancement.

[0005]

The present utility model relates to a mask sheet providing both fine particle trapping capability and improved usability.

Solution

[0006]

In accordance with the present utility model, it is proposed

a mask sheet including a first fibrous layer and a second fibrous layer provided on the side of one surface of the first fibrous layer,

while the average diameter of the fibers, which are the fibers that form the second fibrous layer, is greater than the average diameter of the fibers, which are the fibers that form the first fibrous layer,

the average diameter of the fibers constituting the fibers constituting the first fibrous layer is 0.2 µm or more and 2 µm or less,

the basis weight of the first fibrous layer is 2 g/m ² or more and 20 g/m ² or less, and

the ratio of the weight of the warp of the second fibrous layer to the weight of the warp of the first fibrous layer is more than 0 and less than 8.

[0007]

In accordance with the present utility model, a mask sheet is further proposed, including a first fibrous layer and a second fibrous layer provided on the side of one surface of the first fibrous layer,

while the average diameter of the fibers, which are the fibers that form the second fibrous layer, is greater than the average diameter of the fibers, which are the fibers that form the first fibrous layer,

the average diameter of the fibers constituting the fibers constituting the first fibrous layer is 0.2 µm or more and 2 µm or less,

the mask sheet has a zone corresponding to the mouth and located in accordance with the position of the user's mouth in the plan view,

the mouth region has one or more connected portions connecting the first fibrous layer and the second fibrous layer in a 20 mm × 20 mm portion of the mouth region in plan view,

the total area of the connected parts is more than 0% and 2% or less of the area corresponding to the mouth in plan view.

Preferred effects from utility model

[0008]

According to the present utility model, a mask sheet providing both fine particle trapping capability and improved usability, and a mask including the mask sheet, are provided.

Brief description of the drawings

[0009]

[Fig. 1] Fig. 1 is an exploded perspective view schematically showing an embodiment of the mask sheet of the present utility model in use.

[Fig. 2] Fig. 2 is an exploded perspective view schematically showing another embodiment of the mask sheet of the present utility model in use.

[Fig. 3] Fig. 3 is a plan view schematically showing another embodiment of the mask sheet of the present utility model.

[Fig. 4] Fig. 4 is a sectional view schematically showing an embodiment of the mask sheet of the present utility model.

[Fig. 5] Fig. 5 is a sectional view schematically showing another embodiment of the mask sheet of the present utility model.

[Fig. 6] Fig. 6 is a sectional view schematically showing another embodiment of the mask sheet of the present utility model.

[Fig. 7] Fig. 7 is a perspective view schematically showing an embodiment of the mask sheet manufacturing apparatus of the present utility model.

[Fig. 8] Fig. 8 is a perspective view schematically showing an embodiment in the case where the mask sheet of the present utility model is used as a wound member.

[Fig. 9] Fig. 9 is a perspective view schematically showing another embodiment in the case where the mask sheet of the present utility model is used as a wound member.

Description of Embodiments

[0010]

In the following, the present utility model will be described based on the preferred embodiment with reference to the accompanying drawings. The mask sheet of the present utility model is designed to cover the mouth and nose of a user when using the mask sheet, thereby preventing foreign matter such as small particles from entering through the mouth and nose.

[0011]

1 and 2 show an embodiment of a mask sheet according to the present utility model in use. The mask sheet 10 shown in FIG. 1 is a so-called insert type mask sheet and is generally a filter sheet. Specifically, the mask 1 shown in this figure includes the mask body 5 and the mask sheet 10 as separate members, and the mask sheet 10 is used as a filter sheet capable of being attached to and detached from the mask body 5. In this embodiment, when using the mask 1, the mask sheet 10 is placed as a filter sheet between the mask body 5 and the user, and placed against the user's mouth and nose, whereby the mouth and nose can be covered.

[0012]

As another embodiment different from this embodiment, for example, the mask sheet 10 and the mask body 5 may be supplied as separate pieces, a sheet holding portion may be provided in the mask body 5 in which the mask sheet 10 may be placed. and from which the mask sheet 10 can be removed and the mask sheet 10 can be configured to be attached to and detached from the main body 5 of the mask. In this case, the mouth and nose can be covered by placing the mask body 5, in which the mask sheet 10 is placed, so that it is placed against the wearer's mouth and nose.

[0013]

The mask sheet 10 shown in FIG. 2 is of the so-called integral type. In particular, the mask 1 shown in this figure includes the mask sheet 10 as the most basic part 5 of the mask. In this embodiment, when using the mask 1, the mask sheet 10 as the mask body 5 is placed against the wearer's mouth and nose, whereby the mouth and nose can be covered.

[0014]

As shown in figures 1 and 2, the mask 1 includes the main part 1 of the mask and two parts 6 and 6 in the form of ear loops. The mask body 5 is preferably a rectangular body having a longitudinal direction and a width direction orthogonal to the longitudinal direction. Ear-loop portions 6 are provided on the peripheral edge of the mask body 5, preferably outside the mouth area A in plan view, and more preferably on both outer areas of the mask body 5 end in the longitudinal direction. As a result, each of the earloop parts 6 and 6 can be "hooked" to the wearer's ear, and the state of covering the user's mouth and nose by the mask main part 5 can be maintained. In the case of the mask 1 shown in Fig. 1, the earloop portions 6 and 6 are attached to the peripheral edge of the main mask portion 5 and are not attached to the mask sheet 10. In the case of the mask 1 shown in Fig. 2, the portions 6 and 6 in the form of ear loops attached directly to the peripheral edge of the mask sheet 10 as the main part 5 of the mask.

[0015]

3 shows another embodiment of a mask sheet 10 of an integral type. The mask 1 shown in this figure is a mask folded in half and including a mask sheet 10 as the most basic part 5 of the mask, as in the embodiment shown in Fig.2. In this embodiment, the two ear-loop portions 6 and 6 are both formed from sheet material and attached directly so that they extend from the peripheral edge of the mask sheet 10 as the main mask portion 5. In the central region of the earloop portion 6, a through hole portion 6A is formed, which is a hole through which the ear passes when the earloop portion 6 is attached to the ear.

The mask 1 of the embodiment shown in FIG. 3 has a first body part 21 being a mask sheet 10 and a second body part 22 being a mask sheet 10, and these body parts 21 and 22 are arranged so that they are connected to each other to form the main part 5 of the mask. In the area of the connecting parts of these main body parts 21 and 22, a connected body part 15 is formed, connecting the main part parts 21 and 22 to each other, having a linear shape and extending in one direction. The connected body part 15 also serves as a flexible hinge when the mask body 5 is folded in half. The first body part 21 and the second body part 22 have substantially the same shape in plan view and have an axisymmetric shape with the connected body part 15 as an axis. As a result, the main body 5 of the mask can assume a three-dimensional shape corresponding to the convex shape of the mouth and nose, with the main body part 15 connected as a flexible hinge.

[0016]

Regardless of whether the mask sheet 10 is used as a filter sheet or as the mask body 5, the mask sheet 10 is generally a rectangular sheet having a longitudinal direction and a width direction orthogonal to the longitudinal direction, and a longitudinal direction of the mask sheet 10 and the longitudinal direction of the mask 1 preferably extend so that they coincide with each other.

[0017]

In the mask body 5 of the embodiment shown in Fig. 1, a plurality of folds are formed so that they extend in the same direction. As a result, the mask body 5 can be stretched, and the nose and mouth and the periphery of the nose and mouth can be covered over a large area with one mask. Alternatively, the main body 5 of the mask may be formed without folds.

In addition, the mask sheet 10 in the embodiment shown in Fig. 1 does not have folds. Alternatively, the mask sheet 10 in this embodiment may be configured such that a plurality of pleats are formed to extend in the same direction so that the mask sheet 10 can be stretched.

The mask sheet 10 as the mask body 5 of the embodiment shown in FIGS. 2 and 3 has no folds. Alternatively, the mask sheet 10 in this embodiment may be configured such that a plurality of pleats are formed to extend in the same direction so that the mask sheet 10 can be stretched.

[0018]

An embodiment of the configuration of the mask sheet 10 will be described below. FIG. 4 schematically shows an embodiment of the mask sheet 10 in a section taken in the thickness direction. The mask sheet 10 is a sheet having a multilayer structure in which the first fibrous layer 11 and the second fibrous layer 12 provided on one surface side of the first fibrous layer 11 are integrally combined. In the embodiment shown in FIG. 4, the mask sheet 10 is a fibrous sheet having a two-layer structure, in which the fibrous layers 11 and 12 are located next to each other, and the second fibrous layer 12 is located all the way from one surface of the first fibrous layer 11. In this embodiment, no other layer is located between the two fibrous layers 11 and 12, but it is acceptable to place other layers between the two fibrous layers 11 and 12. The mask sheet 10 is generally preferably inelastic.

[0019]

The mask sheet 10 has a first surface F and a second surface R, which is a surface located on the side opposite the first surface F. In this embodiment, the first fibrous layer 11 is configured to have the first surface F, and the second fibrous layer 12 is configured to have a second surface R. When the mask sheet 10 is used, the second surface R of the mask sheet 10 is preferably located on the skin-facing surface side, which is the surface facing the wearer's nose and mouth, and the first surface F is preferably located on the side of the non-skin-facing surface, which is the opposite surface to the skin-facing surface. When using the mask sheet 10 as a filter sheet, the first surface F is preferably positioned so that it faces the main body 5 of the mask. When using the mask sheet 10 as the most basic part 5 of the mask, the first surface F preferably forms the outer surface of the mask 1.

[0020]

With regard to the ratio between the characteristics of the fibers constituting the first fibrous layer 11 and the fibers constituting the second fibrous layer 12, the average diameter of the fibers constituting the fibers constituting the second fibrous layer is preferably larger than the average diameter of the fibers constituting the fibers constituting the first fibrous layer. . That is, the mask sheet 10 can be formed by including, in one sheet, a first fibrous layer in which the actual fiber density is relatively high by using fibers having a relatively small fiber diameter, and a second fibrous layer in which the actual fiber density is is relatively low due to the use of fibers having a relatively large fiber diameter.

[0021]

In most cases, the first fibrous layer, having a relatively high actual fiber density, can effectively trap foreign matter in the form of fine particles such as dust, pollen and viruses between the fibers even with a light warp weight, but the first fibrous layer alone cannot sufficiently ensure the strength of the sheet to withstand the practical use of the mask sheet. On the other hand, when the mask sheet is only formed by the first fibrous layer, it is necessary to increase the base weight of the first fibrous layer so that the sheet has sufficient strength to withstand practical use in the mask sheet. In such a case, it is not possible to guarantee the air permeability to such an extent that the user of the mask sheet can easily breathe, and the usability of the mask sheet is reduced.

In order to achieve both of these conflicting properties, by additionally providing a second fibrous layer having a relatively low actual fiber density, in addition to the first fibrous layer, a mask sheet 10 can be obtained, providing both an increase in the ability to trap foreign matter in the form of fine particles by means of the first fiber layer and an appropriate air permeability, while providing sufficient strength to the sheet through the second fibrous layer. Accordingly, when using the mask including the mask sheet 10, air tightness/suffocation during use can be reduced, and breathing can be easily carried out while capturing foreign matter in the form of fine particles sufficiently, so that the usability of the mask sheet can be improved. and a mask including this mask sheet.

[0022]

In particular, for reasons related to properly guaranteeing the air permeability and promoting easy breathing of the wearer of the mask sheet 10, the average diameter D1 of the fibers, which are the fibers forming the first fibrous layer 11 in the mask sheet 10, is preferably 0.2 μm or more. , more preferably 0.3 µm or more, and even more preferably 0.4 µm or more.

For reasons of improving the ability to capture foreign substances in the form of small particles, the average diameter D1 of the fibers is preferably 2 µm or less, more preferably 1.5 µm or less, even more preferably 1 µm or less, even more preferably 0.6 microns or less.

[0023]

In addition, for reasons related to providing sufficient strength to the second fibrous layer 12 and having sufficient strength to withstand practical use as a mask sheet, the average fiber diameter D2 of the fibers constituting the second fibrous layer 12 in the mask sheet 10 is preferably 5 µm or more, more preferably 8 µm or more, and even more preferably 10 µm or more, provided that the average diameter D2 of the fibers is greater than the average diameter D1 of the fibers constituting the fibers constituting the first fibrous layer.

For reasons of both usability of the mask sheet and strength to withstand practical use of the sheet, under the same conditions, the average fiber diameter D2 is preferably 30 µm or less, more preferably 25 µm or less, and even more preferably 20 µm or less.

[0024]

The average diameters D1 and D2 of the fibers constituting the fibers forming the first fibrous layer 11 and the second fibrous layer 12 can be determined by using a scanning electron microscope (SEM), taking into account the maximum width of the cross section of the fibers orthogonal to the longitudinal direction of the fibers. This is the specific procedure.

First, it is checked whether the mask sheet is delaminable or not, and in the case where it is delaminable, the constituent sheets of the mask sheet are carefully separated to check the layer configuration. The fiber diameter of each fibrous layer is then measured.

The diameter of the fibers is measured by randomly selecting 500 fibers while excluding defects such as twisted fiber clumps, fiber crossing areas and polymer droplets from a 2D image of each fibrous layer obtained by SEM inspection and looking directly at the length of the line orthogonal to the longitudinal direction. fibers, as the diameter of the fibers. From the distribution density (histogram) of the measured fiber diameters, the median fiber diameter is obtained, at which the accumulated frequency/repeatability is 50% of all values, and this diameter is taken as the average fiber diameter for each fiber.

[0025]

When the mask sheet includes two fibrous layers, that fibrous layer of the fibrous layers which has a small fiber diameter determined by the above method is the first fibrous layer 11, and the other fibrous layer is the second fibrous layer 12.

As will be described later, when the mask sheet includes three fibrous layers, the fibrous layer of the fibrous layers which has the smallest fiber diameter determined by the method described above is the first fibrous layer 11. Here, one layer adjacent to the first fibrous layer 11 is the second fibrous layer 12, and another layer other than the first fibrous layer 11 and the second fibrous layer 12 is the third fibrous layer 13.

When the mask sheet includes four or more fibrous layers, the fibrous layer having the smallest fiber diameter determined by the above method is the first fibrous layer 11, the fibrous layer located on one outer surface of the mask sheet is the second fibrous layer 12, and the layer adjacent to the first fibrous layer 11 and distant from the second fibrous layer is the third fibrous layer.

When the mask sheet constituent sheet has a multi-layer structure that is not amenable to delamination, 500 fibers are sampled from each of one surface and the other surface of the constituent sheet, and, based on the median fiber diameters determined by the above methods, it is assumed that the diameter of the fibers in the fibrous layer having a surface with the smaller fiber diameter is the first fiber diameter D1, and the diameter of the fibers in the fibrous layer having the surface with the larger fiber diameter is the second fiber diameter D2.

The method for confirming the presence of a fibrous layer and the method for determining the average fiber diameter described above are also commonly applied to other measurement methods in the present description.

[0026]

With regard to the ratio between the basis weight of the first fibrous layer 11 and the basis weight of the second fibrous layer 12, the ratio (M2/M1) of the basis weight M2 of the second fibrous layer 12 to the basis weight M1 of the first fibrous layer 11 is preferably within a predetermined range. In particular, for reasons of sufficient strength to withstand practical use of the sheet, the ratio (M2/M1) of the weight of the base M2 of the second fibrous layer 12 to the weight of the base M1 of the first fibrous layer 11 is preferably greater than 0, more preferably 0.25 or more, even more preferably 0.5 or more, even more preferably 1 or more, and even more preferably 2 or more.

For reasons of further improvement in usability, in particular to ensure adequate air permeability of the mask sheet, the ratio (M2/M1) of the weight of the base M2 of the second fibrous layer 12 to the weight of the base M1 of the first fibrous layer 11 is preferably less than 8, more preferably 7.5 or less, and even more preferably 7 or less. By setting such a range of values, the mask 1 including the mask sheet 10 can be formed thin, so that the usability of the mask can be improved, and the usability of the mask sheet and the mask including the mask sheet can be improved.

[0027]

In particular, the basis weight M1 of the first fibrous layer 11 in the mask sheet 10 is preferably 2 g/m ² or more, more preferably 2.5 g/m ² or more, even more preferably 3 g/m ² or more, preferably 20 g /m ² or less, more preferably 18 g/m ² or less, even more preferably 15 g/m ² or less, and even more preferably 8 g/m ² or less. By having the weight of the base M1 in such a range of values, both an improvement in the ability to capture fine particles and an improvement in usability can be effectively achieved because the mask 1 provided with the mask sheet 10 is configured to be thin.

[0028]

In addition, the basis weight M2 of the second fibrous layer 12 in the mask sheet 10 is preferably 5 g/m ² or more, more preferably 10 g/m ² or more, even more preferably 15 g/m ² or more, preferably 30 g/m ² or less, more preferably 25 g/m ² or less, and even more preferably 20 g/m ² or less. When the weight of the base M2 is in this range, the mask can be made thinner to improve the handling comfort of the mask, and adequate air permeability of the mask can be ensured to reduce air tightness/suffocation when using the mask and to facilitate breathing. As a result, the usability of the mask sheet 10 and the mask including the mask sheet can be further improved.

[0029]

The warp weight M1 of the first fibrous layer 11 and the warp weight M2 of the second fibrous layer 12 in the mask sheet 10 are calculated by determining the presence of each fibrous layer by the means described above, separating each fibrous layer, cutting each separated fibrous layer into four squares with a side length of 20 mm, and dividing the mass (g) by the size of the cut sheet (400 mm ² =0.0004 m ² ).

[0030]

Another embodiment of the configuration of the mask sheet 10 will be described below with reference to FIG. In the following description, components different from each of the above-described embodiments will be mainly described, and similar components will be given the same reference numerals, and description of these components will be omitted. The above description of the mask sheet applies accordingly to components not specifically described.

[0031]

The mask sheet 10 of the embodiment shown in FIG. 5 is a fibrous sheet having a multilayer structure including a first fibrous layer 11 and a second fibrous layer 12 as in the embodiment shown in FIG. 4 and described above. The mask sheet 10 shown in FIG. 5 has one or more connected parts B connecting the first fibrous layer 11 and the second fibrous layer 12. The connected part B is formed by crimping, adhesively bonding or fusing the fibrous layers together. In the bonded part B, the boundary surface of each of the fibrous layers 11 and 12 is missing or the boundary surface is indistinct. In addition, the connected parts B may be formed over the entire extent of the mask sheet 10 in plan view, or may be formed only over a portion of the extent. For reasons of both providing flexibility and strength to the sheet and further improving usability, the connected portion is preferably formed by fusion bonding.

[0032]

The connected part B is formed as a line or as scattered dots in the plan view of the mask sheet 10. When the connected part is formed as a line, it may be a continuous line or a broken line, or it may be a straight line or a curved line. In the case where the connected parts are formed as disparate points, the shape of the connected parts in the plane may be a round shape such as a perfect circle and an ellipse, a polygonal shape such as a rectangle and a hexagon, a shape like an alphabet letter such as an X-shaped shape and Y-shape, lattice shape, or a combination of these shapes.

[0033]

The mask sheet 10 of this embodiment has a mouth area A (see FIGS. 1, 2 and 3) which is located according to the position of the user's mouth in the plan view of the mask sheet 10. The mouth area A is the area , shown by the shape of the like figure in the plan view, when the center of the mask sheet 10 in the plan view coincides with the center of the like figure in the plan view, obtained by reducing the area of the mask sheet 10 in the plane to 70%. That is, the region A corresponding to the mouth is located in the central region of the mask sheet 10 in the plan view. When the area of the first fibrous layer 11 in the plan view and the area of the second fibrous layer 12 in the plan view differ from each other, the area A corresponding to the mouth has a similar configuration based on the shape and the maximum area of the mask sheet 10 in the plan view.

When the mask sheet 10 is, for example, the double-fold mask shown in FIG. 3, the mouth area A is each area obtained based on the plan view of each of the body parts 21 and 22. Specifically, the area A corresponding to the mouth is the area shown by the shape of the like figure in the plan view when the center of each of the body parts 21 and 22 in the plan view coincides with the center of the like figure in the plan view obtained by reducing the area of each of the parts 21 and 22 of the main part in the plane up to 70%. That is, in the case of the double-fold mask, there is one mouth area A in each body part, and there are a plurality of mouth areas A when the mask body 5 is considered.

When wrinkles are formed in the mask sheet 10, the area A corresponding to the mouth is the area obtained on the basis of the in-plane area when the wrinkles are completely unfolded.

[0034]

As described above, the mask sheet 10 of the present embodiment has a mouth area A and a connected part B, and it is preferable that the number and area of the connected parts B present in the mouth area A have a predetermined ratio. In general, for reasons related to ensuring that the various functions of improving the usability of the mask sheet formed by the fibrous layers and the mask incorporating the mask sheet are performed - sufficiently - the number and area of the connected parts B are preferably small. On the other hand, for reasons related to ensuring the strength of the entire mask sheet 10, it is preferable that the number and area of the connected parts B are large. Therefore, by setting the number and area of the connected parts B present in the area A corresponding to the mouth so as to provide their predetermined ratio, both the ability of each fibrous layer to trap fine particles and ensure proper air transmission can be achieved, and sufficient to provide strength to withstand the practical use of the mask sheet. In addition, by forming the joint part B at least in the zone A corresponding to the mouth, the fluffing of the fibers forming the fibrous layer opposite the user's mouth can be reduced, and the discomfort caused by the fluffy fibers entering the user's mouth or coming into contact can be reduced. with the nose and periphery of the mouth. As a result, the usability of the mask sheet 10 and the mask including the mask sheet can be improved.

[0035]

In particular, the number of connected parts B is preferably 1 or more, more preferably 5 or more, even more preferably 10 or more, preferably 50 or less, more preferably 40 or less, and even more preferably 30 or less in a section with dimensions of 20 mm × 20 mm in zone A corresponding to the mouth in the plan view of the mask sheet 10. By setting the number of connected parts in such a range of values, the usability of the mask sheet 10 and the mask including the mask sheet can be further improved. In the area external to the area A corresponding to the mouth in the plan view of the mask sheet 10, the connected part B may or may not be provided.

[0036]

In addition, with regard to the area of the connected part B in the plan view and the area A of the mask sheet 10 corresponding to the mouth, the total area of the connected parts B in the plane is preferably more than 0%, more preferably 0.05% or more, preferably 2%. or less and more preferably 1% or less of the area of zone A corresponding to the mouth in the plane. By setting the area ratio of the connected parts to such a range of values, the ability to capture small particles and the usability of the mask sheet 10 and the mask including the mask sheet can be further improved.

[0037]

The average area of each of the connected parts B is preferably 0.1 mm ² or more, more preferably 0.15 mm ² or more, preferably 3 mm ² or less, and more preferably 1 mm ² or less. When the average area of the connected parts B is in such a range of values, the ability to capture fine particles and the usability of the mask sheet 10 and the mask including the mask sheet can be further improved.

[0038]

The number and average area of connected parts B can be determined by the method below. Specifically, the number of connected parts B formed and the area of each of the connected parts B are calculated using image processing software from a two-dimensional image obtained by examining the inside of the mouth area A of the mask sheet 10 in plan view by SEM. Here, the number of all connected parts B within a 20 mm × 20 mm area in the mouth zone A and the area of each connected part B are obtained, and the arithmetic mean of the area is taken as the average area. When the mask sheet 10 has wrinkles, the measurement is performed based on the plan view when the sheet is fully flattened.

[0039]

For reasons of improving the air permeability of the mask sheet and further improving the usability of the mask, the air tightness of the mask sheet is preferably 0.5 kPa⋅s/m or less, more preferably 0.4 kPa⋅s/m or less, even more preferably 0.3 kPa⋅s/m or less, even more preferably 0.2 kPa⋅s/m or less, and the lower the value, the more preferable, but a value of 0.5 kPa⋅s/m or more , is more realistic. The lower the airtightness, the higher the air permeability. Air tightness (kPa⋅s/m) is determined using an air tightness tester (KES-F8-AP1 manufactured by Kato Tech Co., Ltd.) when air at 25°C and 50% relative humidity passes through the sheet in the thickness direction and wherein the mask sheet to be measured is fixed so as to cover the air passage hole. The airtightness of the mask sheet in the range described above can be achieved, for example, by adjusting at least one of the fiber diameter, the fiber diameter distribution and the base weight of each fibrous layer, and in particular by adjusting at least one of the fiber diameter, the diameter distribution fibers and the weight of the base of the first fibrous layer 11. The area of the air passage hole, which is used to determine the air tightness, is 2π cm ² , the air passage amount/air permeability value is 4 cm ³ /(cm ² ⋅s), and the piston speed is 2 cm /with. The size of sheets used for measurements is 40 mm×40 mm, air tightness values are determined for each of a total of ten sheets, and the average value of these measured values is taken as air tightness.

When measuring the degree of entrapment and airtightness, it is necessary to ensure that the measuring points coincide. That is, it is necessary to ensure that the centers of the respective measurement portions substantially coincide with each other at ten points at which the degree of entrapment is determined and ten points at which airtightness is determined. In addition, in both measurements, when the sheet to be measured is brought into intimate contact with the measurement portions, the sheet may be deformed. Therefore, in order to eliminate the influence of sheet deformation on the measurement results, it is preferable to determine the airtightness in the presence of a large area of the parts to be measured before determining the degree of entrapment.

[0040]

It is preferable that, as shown in FIG. 6, the third fibrous layer 13 is further provided on the side of that surface of the first fibrous layer 11 with which the second fibrous layer 12 is not disposed in order to maintain a sufficient ability to capture fine particles by suppressing fluff. and undesirably dropping constituent fibers having a relatively small fiber diameter in the first fibrous layer, reducing the discomfort caused by fluffy fibers and loose fibers during use, and further improving the usability of the mask sheet and the mask incorporating the mask sheet.

[0041]

The mask sheet 10 shown in FIG. 6 is a sheet having a multilayer structure in which the first fibrous layer 11, the second fibrous layer 12 provided on one surface side of the first fibrous layer 11, and the third fibrous layer 13 provided on the other side surfaces of the first fibrous layer 11 are combined into one. In the embodiment shown in Fig.6, the second fibrous layer 12 and the third fibrous layer 13 form a fibrous sheet having a three-layer structure in which the fibrous layers 11, 12 and 13 are located next to each other, while the first fibrous layer 11 is located between fibrous layers 12 and 13, a second fibrous layer 12 is located along one surface side of the first fibrous layer 11, and a third fibrous layer 13 is located along the other surface side of the first fibrous layer 11. In this embodiment, no other layer is located between the fibrous layers 11 and 12 and between fibrous layers 11 and 13, but it is acceptable to place other layers between these fibrous layers 11, 12 and 13.

[0042]

The mask sheet 10 of the embodiment shown in FIG. 6 has a first surface F and a second surface R, which is a surface opposite the first surface F, similar to the above-described embodiment. In this embodiment, the third fibrous layer 13 is configured to have a first surface F, and the second fibrous layer 12 is configured to have a second surface R. When using the mask 1 provided with the mask sheet 10 of the embodiment 6, one of the first surface F and the second surface R of the mask sheet 10 is preferably located on the skin-facing side of the surface, and the other surface is preferably located on the non-skin-facing side of the surface.

[0043]

In addition, in the mask sheet 10 of the embodiment shown in FIG. 6, the average diameter D3 of the fibers constituting the fibers constituting the third fibrous layer 13 is also preferably greater than the average diameter D1 of the fibers constituting the fibers constituting the first fibrous layer 11. With such a configuration, it is possible to securely protect the first fibrous layer providing the fine particle foreign matter trapping ability from excessive external force generated during use of the mask sheet 10 and the mask including the mask sheet 10, and to sufficiently maintain the functional abilities of the first fibrous layer. In addition, since strength of the sheet can be ensured by both the second fibrous layer and the third fibrous layer, it is also possible to further reduce the fiber density of the second fibrous layer and the third fibrous layer to ensure proper air permeability. As a result, the usability of the mask sheet 10 and the mask including the mask sheet 10 can be further improved.

[0044]

The average diameter D3 of the fibers constituting the fibers constituting the third fibrous layer 13 may be in the same range as the average diameter D2 of the fibers constituting the fibers constituting the second fibrous layer 12 described above, provided that the average diameter D3 fibers constituting the fibers constituting the third fibrous layer 13 is larger than the average diameter D1 of the fibers constituting the fibers constituting the first fibrous layer 11. When considering the relationship between the average fiber diameter D2 and the average fiber diameter D3, it should be noted that the average fiber diameter D2 may be greater than the average fiber diameter D3, the average fiber diameter D2 may be smaller than the average fiber diameter D3, or the average fiber diameter D2 and the average fiber diameter D3 may be the same. The average fiber diameter D3 can be determined in the same manner as the above-described method for determining the average fiber diameters D1 and D2.

[0045]

Regarding the ratio between the weight of the warp of the first fibrous layer 11 and the weight of the warp of the third fibrous layer 13, it should be noted that the ratio (M3/M1) of the weight of the warp M3 of the third fibrous layer 13 to the weight of the warp M1 of the first fibrous layer 11 is preferably within a predetermined range. In particular, the ratio (M3/M1) of the weight of the base M3 of the third fibrous layer 13 to the weight of the base M1 of the first fibrous layer 11 is preferably more than 0, more preferably 0.25 or more, even more preferably 0.5 or more, preferably less than 8, more preferably 7.5 or less, and even more preferably 7 or less. By setting values in such a range, the mask 1 including the mask sheet 10 can be formed thin even when it has a multilayer structure, so that the handling convenience of the mask can be improved, and the usability of the mask sheet and the mask including yourself this mask sheet. The weight of the warp M3 of the third fibrous layer 13 may be in the same range as the weight of the warp M2 of the second fibrous layer 12 described above.

[0046]

The mask sheet 10 shown in FIG. 6 also preferably has a mouth area. In this case, the area corresponding to the mouth may be the same area as in the above-described embodiment.

[0047]

Preferably, in the mask sheet 10 shown in FIG. 6, a bonded portion (not shown) connecting at least two fibrous layers is formed, and it is also preferable that the bonded portion is formed in an area corresponding to the mouth. This bonded portion is the same as or similar to bonded portion B described above and is formed by crimping, adhesive bonding, or fusing the fibrous layers together. The connected part in this embodiment may be provided according to (a) a configuration in which the first fibrous layer 11 and the second fibrous layer 12 are connected and the first fibrous layer 11 and the third fibrous layer 13 are not connected, (b) a configuration in which the first the fibrous layer 11 and the third fibrous layer 13 are connected and the first fibrous layer 11 and the second fibrous layer 12 are not connected, and (c) a configuration in which all the fibrous layers, namely the first fibrous layer 11, the second fibrous layer 12 and the third fibrous layer 13 connected, or may be formed by combining configurations (a)-(c).

When the mask sheet 10 shown in FIG. 6 has a bonded portion connecting at least two fibrous layers, the average area of the bonded portions has a value determined in the same way as in the method for determining the average area of bonded portions B described above for all bonded parts in the configurations (a)-(c) described above.

[0048]

Examples of the fibers forming the first fibrous layer 11, the second fibrous layer 12 and optionally the third fibrous layer 13 independently include natural fibers, synthetic fibers and regenerated fibers. Examples of natural fibers include natural cellulose fibers such as pulp fibers and cotton fibers. Examples of synthetic fibers include polyolefin resin fibers such as polyethylene and polypropylene (PP), polyester resin fibers such as polyethylene terephthalate, polyamide resin fibers, vinyl resin fibers such as polyvinyl chloride and polystyrene, acrylic resin fibers such as polyacrylic acid and polymethyl methacrylate, fibers containing one or more thermoplastic resins such as fluorine-containing resins such as polyperfluoroethylene, and core-sheath multicomponent fibers and side-by-side multicomponent fibers containing components from these resins. Examples of regenerated fibers include rayon fibers, copper ammonium fibers and tencel fibers. These fibers may be used singly or in combination of two or more.

[0049]

For reasons related to improving usability, such as improving the feel and strength in use, while improving the effectiveness of the mask sheet, it is preferable to independently use synthetic fibers from these fibers as fibers forming the first fibrous layer 11, the second fibrous layer 12 and optionally a third fibrous layer 13, and it is also preferred that the fibrous layers 11, 12 and 13 are formed independently by only one kind of fiber.

[0050]

As a collection of fibers forming the first fibrous layer 11, the second fibrous layer 12 and, if necessary, the third fibrous layer 13, various fibrous sheets such as paper, woven fabric and non-woven fabric containing the above-described fibers can be used independently, for example. For reasons related to improving the usability of the mask sheet 10 and the mask including the mask sheet 10 by improving the feel while reducing the flaking and shedding of the fibers, it is preferable to use at least a non-woven material for the second fibrous layer 12, which can form a surface, facing the skin, that is, the surface facing the wearer's nose and mouth, and more preferably, a nonwoven fabric is used for at least the second fibrous layer 12 and the third fibrous layer 13.

[0051]

When a nonwoven fabric is used for the fibrous layers 11, 12, and 13, various nonwoven fabrics can be used, such as air-through-bonded non-woven fabric, air-laid non-woven fabric, spunbond non-woven fabric, hydroentangled non-woven fabric, meltblown non-woven fabric , a non-woven fabric obtained by needling, and a non-woven fabric produced by electrospinning. For reasons related to further reducing fiber fluff and shedding, it is preferable to use a spunbond nonwoven fabric for the second fibrous layer 12 and the third fibrous layer 13. In addition, for reasons related to facilitating downsizing of the constituent fibers, it is also preferable to use as the first fibrous layer 11 is a collection of deposited fibers or a non-woven fabric produced by an electrospinning process. The electrospinning method is a method in which a liquid raw material containing a resin serving as a fiber raw material is charged in an electric field, and the charged liquid raw material is discharged towards a fiber spinning object.

[0052]

When using the mask sheet 10 described above, it is preferable that the outer surface of the second fibrous layer 12 or the outer surface of the third fibrous layer 13 is the surface facing the wearer's mouth. By arranging the mask sheet in this way, an improved feel due to the relatively thick fibers of the second fibrous layer 12 or the third fibrous layer 13 can be generated while reducing the discomfort in use caused by the fluffing and shedding of fibers from the first fibrous layer, and as a result, the usability of the mask sheet can be improved. 10 and a mask including a mask sheet 10. In particular, in the case of the mask sheet 10 shown in FIGS. 4 and 5, the second surface R, which is the outer surface of the second fibrous layer 12, is preferably placed as a surface opposite user's mouth. Furthermore, in the case of the mask sheet 10 shown in FIG. 6, one of the first surface F, which is the outer surface of the third fibrous layer 13, or the second surface R, which is the outer surface of the second fibrous layer 12, is preferably placed as a surface, located in front of the user's mouth.

[0053]

The thickness T1 (see FIGS. 4-6) of the mask sheet 10 is preferably 0.2 mm or more, more preferably 0.4 mm or more, preferably 3 mm or less, and more preferably 2 mm or less. By setting the thickness T1 in such a range of values, the thickness of the sheet is reduced, and sufficient handling and sufficient usability are provided. The thickness T1 of the mask sheet 10 is measured at five or more locations using a constant pressure thickness gauge (model number PG-11, manufactured by Tekrock Corporation) under a load of 3.7 gf/m ² (36.3 mN/m ² ) in accordance with JIS K 6402 (JIS - Japanese Industrial Standard), and the arithmetic mean of the thickness is taken as the thickness T1. When the mask sheet 10 is wrinkled, the measurement is performed based on the actual thickness of the sheet in the fully expanded/flattened state of the sheet.

[0054]

The basis weight of the entire mask sheet 10 is preferably 30 g/m ² or more, and preferably 100 g/m ² or less.

[0055]

Provided that the effects of the present utility model are exhibited, another fibrous layer can be placed between the first fibrous layer 11 and the second fibrous layer 12 and, if necessary, between the first fibrous layer 11 and the third fibrous layer 13. With the additional placement of other fibrous layers, each boundary the surface of the fibrous layer 11 and 12 and the remaining fibrous layers and each boundary surface of each fibrous layer 11 and 13 and the remaining fibrous layers may be distinctly or indistinctly defined independently. Further, the first fibrous layer 11 and the other fibrous layer may be formed such that they are not delaminable, and the other fibrous layer and the second fibrous layer 12 may be formed such that they are delaminable, the first fibrous layer 11 and the other fibrous the layer may be formed such that they are delaminable and the other fibrous layer and the second fibrous layer 12 may be formed such that they are not delaminable, or the layers being the fibrous layers 11 and 12 and the other fibrous layers may be formed so that they will or will not be delaminating. Similarly, the first fibrous layer 11 and the other fibrous layer may be formed such that they are not delaminable, and the other fibrous layer and the third fibrous layer 13 may be formed such that they are delaminable, the first fibrous layer 11 and the other fibrous layer. may be formed such that they are delaminable, and the other fibrous layer and the third fibrous layer 13 may be formed such that they are not delaminable, or layers being fibrous layers 11 and 13 and other fibrous layers may be formed so that they will or will not be susceptible to delamination. As another fibrous layer, for example, a non-woven material containing the above-mentioned synthetic fiber can be used.

For reasons of allowing the foreign matter to be easily retained between the fibrous layers and allowing the quality of the mask sheet to be improved, it is preferable that all the fibrous layers of the mask sheet 10 are peelable from each other. As shown in the above embodiment, in the configuration in which the first fibrous layer 11 and the second fibrous layer 12 are adjacent to each other, it is preferable that the first fibrous layer 11 and the second fibrous layer 12 are peelable from each other. In addition, when the third fibrous layer 13 is adjacent to the first fibrous layer 11, it is preferable that the first fibrous layer 11 and the third fibrous layer 13 are peelable from each other.

[0056]

The mask sheet 10 described above has been described with reference to embodiments corresponding to the single sheet state, but the mask sheet 10 may be wound, for example, as a wound member. Specifically, the mask sheet 10 of this embodiment is configured as a continuous member having the shape of a long continuous member, and the mask sheet can be wound in the longitudinal direction to form a wound member.

[0057]

When the mask sheet is in the form of a wound member, it is preferable that the mask sheet 10 has perforations spaced at predetermined intervals in its longitudinal direction and formed along a direction intersecting the longitudinal direction. With such a configuration, it is possible to use the mask sheet as one separate sheet by cutting the mask sheet each time the mask sheet 10 is used, so that it is possible to maintain cleanliness and further enhance the usability of the mask sheet 10 and the mask including the mask sheet 10. In particular, , this configuration is preferred when the mask sheet 10 is used as a filter sheet.

[0058]

The manufacturing method of the mask sheet 10 will be described hereinafter with reference to the manufacturing apparatus 100 shown in FIG. 7, taking the two-layer structure configuration shown in FIG. 5 as an example. The manufacturing apparatus 100 suitably used for manufacturing the mask sheet 10 includes a raw material roll 110, a spinneret 120, a device 130 for forming connected parts, and a device 140 for forming perforations.

[0059]

First, the fibrous sheet raw material constituting the second fibrous layer 12 is unwound from the raw material roll 110 and moved in the moving direction MD. As the starting material unwound from the starting material roll 110, a starting material in the form of a nonwoven material such as a spunbonded nonwoven material can be used.

[0060]

Next, the first fibrous layer 11 is applied to the starting material for the second fibrous layer 12 moving in the moving direction MD. In this embodiment, the fibers constituting the first fibrous layer 11 are directly and continuously formed by spinning by a plurality of spinnerets 120 arranged along the width direction CD orthogonal to the moving direction MD, and applied to the upper surface of the starting material for the second fibrous layer 12 moving in the moving direction MD (hereinafter, this manufacturing method is also referred to as the first manufacturing method). As a result, a laminate 1S is formed in which the constituent fibers of the first fibrous layer 11 are superimposed on the upper surface of the parent material for the second fibrous layer 12, preferably on the entire upper surface of the parent material for the second fibrous layer 12. The laminate 1S is in the form of a continuous material and extends into direction MD of movement, and the first fibrous layer 11 and the second fibrous layer 12 are adjacent to each other.

[0061]

As the spinneret 120, for example, an apparatus used in a melt blown process or an electrospinning process can be used. For reasons related to efficient spinning of a fiber having a small size, an apparatus used for the electrospinning method can be suitably used. The device used in the electrospinning method generally includes a conductive material spinneret that discharges a liquid raw material containing resin, a conductive electrode that is located opposite the spinneret and creates an electric field between the spinneret and the electrode, and a voltage generator that is a power supply providing a voltage supply between the die and the electrode, and the liquid raw material can be discharged from the die into the electric field and towards the object.

[0062]

When the laminate 1S is formed, instead of spinning the constituent fibers of the first fibrous layer 11 by the spinneret 120, for example, a base nonwoven fabric having a two-layer structure in which the first fibrous layer 11 and the second fibrous layer are superimposed on each other can be prepared in advance as a roll 110 of the raw material without forming the spinneret 120, and the raw non-woven fabric can be unwound from the roll of raw material 110 and moved in the direction MD of movement. Alternatively, the first fibrous layer may be applied to the upper surface of the second fibrous layer 12 by using separately the starting material roll for the first fibrous layer 11 and the starting material roll for the second fibrous layer 12, and the starting material is unwound from each roll of starting material (hereinafter referred to as the manufacturing method is also referred to as the second manufacturing method).

[0063]

In addition, when the mask sheet 10 having the three-layer structure shown in FIG. 6 is formed, after the first fibrous layer 11 is applied to the raw material for the second fibrous layer 12, for example, the fibrous sheet raw material constituting the third fibrous layer 13 is unwound from ( not shown) of the second roll of raw material and moved along the moving direction MD, and the third fibrous layer 13 was applied to the top surface of the first fibrous layer 11 to form a laminate 1S with a three-layer structure. In this case, the raw material roll 110 and the second raw material roll are separate members. The laminate 1S in this embodiment is in the form of a continuous material and extends in the direction of movement MD, in which the third fibrous layer 13 and the second fibrous layer 12 are located with the first fibrous layer 11 disposed therebetween, and the first fibrous layer 11 and the third fibrous layer 13 are adjacent to each other, and the first fibrous layer 11 and the second fibrous layer 12 are adjacent to each other. As the starting material unwound from the second roll of starting material, a starting material in the form of a nonwoven material, such as a spunbond nonwoven material, can be used.

[0064]

As another method for forming the mask sheet 10 having the three-layer structure shown in FIG. 6, the following method can be mentioned. First, the fibers are formed by spinning/spinning by a predetermined method to form the second fibrous layer 12. Next, the first fibrous layer 11 is formed on the second fibrous layer 12 by spinning the fibers so that they have an average fiber diameter that is smaller than the average diameter of the constituent fibers of the second fibrous layer 12 The fiber constituents of the first fibrous layer 11 are preferably formed by spinning so that their diameter is 0.2 µm or more and 2 µm or less. Then, the third fibrous layer 13 is formed on the first fibrous layer 11 by spinning the fibers so that they have an average fiber diameter that is larger than the average diameter of the constituent fibers of the first fibrous layer 11, whereby a 1S laminate having a three-layer structure is obtained (hereinafter, this manufacturing method also referred to as the third manufacturing method).

Thereafter, the laminate 1S is passed through a corrugated roller or bonding device 130, described later, to join all the fibrous layers into one whole. That is, the sheet obtained by this manufacturing method has the same configuration as the so-called SMS structure nonwoven fabric (spunbond S layer, melt blown layer M, spunbond S layer) and the layer meltblown in the SMS nonwoven fabric corresponds to the first fibrous layer 11. In this case, the number of layers in the first fibrous layer 11 may be appropriately changed according to the predetermined mask sheet, and the mask sheet may have the same configuration as , for example, a nonwoven fabric with an SMMS structure or a nonwoven fabric with an SMMMS structure.

[0065]

From the first to third manufacturing methods described above, it is preferable to select the first manufacturing method or the third manufacturing method rather than the second manufacturing method, for reasons of easy production of a sheet having high adhesive adhesion between the first fibrous layer and the other fibrous layer and having a high the degree of integrity of the entire sheet. That is, it is preferable to select the second manufacturing method (the first manufacturing method or the third manufacturing method in this order) as the suitable manufacturing method.

[0066]

Then, the laminate 1S is introduced into the connected part forming apparatus 130 to form a connected part B connecting the first fibrous layer 11 and the second fibrous layer 12, and the fibrous layers are joined to form a whole. The connected parts B in this embodiment are formed as scattered dots. For example, an ultrasonic embossing device, a hot stamping device, or the like can be used as the device 130 for forming the connected parts. The bonded portions B may be formed over the entire area of the laminate 1S in plan view, or alternatively they may be formed over only the portion in which the mouth area A is to be formed. In the case of the 1S laminate having a three-layer structure, the connected part B must connect at least the first fibrous layer 11 and the second fibrous layer 12, and in addition to the fibrous layers 11 and 12, the third fibrous layer 13 can be additionally attached to combine the fibrous layers into one whole. . In the case of the 1S laminate having a three-layer structure, it is preferable that the fibrous layers 11, 12, and 13 are simultaneously introduced into the connected portion forming apparatus 130 in a state in which the fibrous layers are superimposed on each other, and the fibrous layers are simultaneously joined to form one of the whole, since the number of connected parts B to be formed can be reduced, and the strength of the sheet can be increased while maintaining adequate air permeability.

[0067]

When the connected parts B are formed as discrete points, the distances between the connected parts B defined along the moving direction MD are independently preferably 1 mm or more, more preferably 3 mm or more, preferably 20 mm or less, and more preferably 10 mm or less.

In addition, the distances between the connected parts B, defined along the width direction CD, are independently preferably 1 mm or more, more preferably 3 mm or more, preferably 20 mm or less, and more preferably 10 mm or less. The distance between the connected parts B is measured as the distance between the centers of the connected parts B to be measured.

[0068]

Since the laminate 1S in which the bonded part B is formed is a sheet having the form of a long continuous sheet, this material can be used as the mask sheet 10 having the form of a long continuous sheet. The mask sheet 10, which is in the form of a long continuous sheet, can be wound and stored or distributed as a wound member in which the sheet 10 is wound. This wound member is, for example, a roll of raw material for the mask sheet 10.

[0069]

In addition, the mask sheet 10 having the form of a long continuous sheet can be obtained as one separate sheet by subjecting the mask sheet 10 to a processing such as cutting to obtain a predetermined size. The mask sheet 10 can suitably be used as a kind of filter sheet. The mask sheet 10 as one single sheet may be stored or marketed as a package in which a plurality of mask sheets 10 are stacked and placed in a packaging bag.

[0070]

As another processing option for the mask sheet 10 having the form of a long continuous sheet, the mask sheet 10 having the form of a long continuous sheet may be provided with earloop portions by attaching the earloop portions—at predetermined intervals along the movement direction MD—to both ends of the sheet 10 defined in the width direction CD, and then cutting the sheet 10 in the width direction between earloop portions at intervals along the movement direction MD. Alternatively, the mask sheet 10, having the form of a long continuous sheet, is cut into separate sheets so that they have a predetermined size, and thereafter, the earloop portions are attached to the peripheral edges, whereby the mask sheet 10 can be obtained as one separate sheet, including parts in the form of ear loops. These mask sheets 10 can respectively be used as mask main parts 5 themselves, and can actually be used as masks 1.

[0071]

As another option for processing the mask sheet 10, which is in the form of a long continuous sheet, the mask sheet 10 is inserted into the perforator 140 to form perforations C consisting of a series of discontinuous cuts/cuts. The perforations C are formed along a direction intersecting the longitudinal direction (ie, the moving direction MD) of the mask sheet 10, preferably along the width direction CD. The perforations C extend along a direction intersecting the longitudinal direction of the mask sheet 10 and are formed at predetermined intervals in the longitudinal direction of the laminate 1S. As the device 140 for forming perforations, for example, a device that periodically irradiates the mask sheet 10 with laser light to cut the sheet 10 in the thickness direction can be used.

[0072]

The lengths of the incisions/cuts in the perforations C, defined along the extension direction of the perforations C, are independently preferably 1 mm or more, more preferably 3 mm or more, preferably 20 mm or less, and more preferably 10 mm or less. The distances between notches/cuts adjacent to each other along the perforation extension direction C are independently preferably 1 mm or more, more preferably 3 mm or more, preferably 20 mm or less, and more preferably 10 mm or less.

[0073]

Even when the perforations C are formed in the mask sheet 10 having the shape of a long continuous sheet, the mask sheet 10 having the perforations C is in the form of a long continuous sheet because the mask sheet 10 is not completely separated. In this case, the mask sheet 10, having the form of a long continuous sheet, in which the perforations C are formed, can be wound and stored or distributed as a wound element 10A, in which the sheet 10 is wound.

[0074]

A wound member 10A formed from a mask sheet 10 having the shape of a long continuous sheet in which perforations C are formed may be cut, for example, in a direction orthogonal to the axial direction of the wound member 10A to form a second wound member 10B (see FIG. 8) having the same diameter as the wound member 10A and a smaller width along the width direction CD than the wound member 10A. In addition, as shown in FIG. 8, the mask sheet 10 in the second wound member 10B may be wound in a roll and divided into third wound members 10C having a diameter smaller than that of the second wound member 10B.

[0075]

The third wound member 10C of this embodiment is a roll-shaped product formed from a mask sheet 10 in the form of a long continuous sheet in which perforations C extending in the axial direction are formed. The third wound member 10C has a smaller width along the width direction CD than the wound member 10A and a smaller diameter than the second wound member 10B.

[0076]

As shown in FIG. 9, the third coiled element 10C may be stored or distributed to the market, for example, as a package 80 in which the third wound element 10C is placed in a packaging bag 50. The packaging bag 50 shown in this figure is made with hole 51 to pull out the mask sheet 10 placed in the packaging bag 50 at an arbitrary location, and the mask sheet 10 can be pulled out from the hole 51. After the mask sheet 10 placed in the package 80 is pulled out from the hole 51, the mask sheet 10 is torn at a predetermined location. , for example, at a location where the perforations C are formed, whereby the mask sheet 10 as one separate sheet can be obtained from the third wound member 10C, which is the mask sheet 10 having the form of a long continuous sheet. The mask sheet 10 can suitably be used as a kind of filter sheet.

With this configuration, a clean and unused sheet can be taken out every time it is used, and a single sheet having a predetermined size can be easily obtained. In addition, it is easier to obtain a plurality of mask sheets 10 as individual sheets from a single wound member. As a result, the suitability of the mask sheet as a filter sheet and the usability are further improved.

[0077]

Through the above operations, the mask sheet 10 of each embodiment can be obtained. In addition, as is evident from the above description, according to the present utility model, not only a mask sheet and a mask are provided, but also a method for using the mask sheet. As an application method, it is contemplated that the mask sheet can be used as a filter sheet capable of being attached to and detached from the mask main body in the mask. Alternatively, a mask sheet may be used as the body of the mask.

[0078]

Although the present utility model has been described above based on the preferred embodiments, the present utility model is not limited to the above described embodiments.

Examples

[0079]

The present utility model will be described hereinafter in more detail with reference to the Examples. However, the scope of the present utility model is not limited to such Examples.

[0080]

[Example 1]

As the mask sheet 10, a sheet having a three-layer structure similar to that shown in FIG. 6 was obtained. First, when moving the raw material, which is a spunbond nonwoven fabric formed from polypropylene resin, and is intended to form the second fibrous layer 12, in the direction MD of movement, the electrospinning method was performed by 16 spinnerets 120 located opposite the entire upper surface, and the first fibrous layer 11 was formed on the upper surface of the second fibrous layer 12. The forming conditions for the constituent fibers of the first fibrous layer 11 were as follows. Next, a raw material of a polypropylene resin spunbonded nonwoven fabric to form the third fibrous layer 13 was applied to the upper surface of the first fibrous layer 11 to obtain a 1S laminate having a three-layer structure. In each of the fibrous layers 11, 12 and 13 in the laminate 1S, no bonded portion B has been formed.

The laminate 1S was introduced into the unit 130 for forming the connected parts and subjected to ultrasonic embossing to form the connected parts B in the form of scattered dots connecting the fibrous layers 11, 12 and 13, whereby a mask sheet 10 having the shape of a long continuous sheet was obtained. The connected parts B in the plan view were in the form of a perfect circle with a diameter of 1 mm, and the average area of each of the connected parts B was 0.785 mm ² . The distance between the connected parts B, defined along the movement direction MD, was 5.1 mm, and the distance between the connected parts B, defined along the width direction CD, was 3.42 mm. The number of connected parts B formed in a section with dimensions of 20 mm × 20 mm in the zone A corresponding to the mouth was 15.

Thereafter, the mask sheet 10 having the shape of a long continuous sheet was cut to obtain a sheet with a length of 150 mm along the moving direction MD and a length of 100 mm along the width direction CD, whereby the mask sheet 10 as a separate sheet of this example was obtained.

[0081]

<Forming Conditions>

- Forming environment: 25°C, 50% relative humidity

- Liquid starting material for electrospinning: heated liquid melt of a resin composition containing 95 wt.% polypropylene (PP) (manufactured by PolyMirae, MF650Y, melting point - 155°C) and 5 wt.% acylalkyltaurine salt (N-stearoyl-N -sodium methyl taurate; manufactured by Nikko Chemicals Co., Ltd., Nikkol SMT) as an additive

- Voltage applied to the spinning die: -10 kV

- Shortest distance between spinneret and fiber layer: 300 mm

- Die diameter: 0.25 mm

[0082]

[Examples 2-6]

A first fibrous layer 11 having a warp weight and an average fiber diameter shown in Table 1 was formed on the top surface of the second fibrous layer 12 by adjusting the second fibrous layer 12's speed and applied voltage during electrospinning. Except for this, the mask sheet 10 as one separate sheet having a three-layer structure was obtained in the same way as in Example 1.

[1001]

[Examples 7-9]

A first fibrous layer 11 having a warp weight and an average fiber diameter shown in Table 1 was formed on the top surface of the second fibrous layer 12 by adjusting the second fibrous layer 12's speed and applied voltage during electrospinning. Except for this, the mask sheet 10 as one separate sheet having a three-layer structure was obtained in the same way as in Example 1.

[1002]

[Comparative Example 1]

A single sheet mask sheet 10 having a three-layer structure was obtained in the same manner as in Example 1, except that the first, second, and third fibrous layers were respectively changed to have a warp weight shown in Table 1. , and no connected part B was formed.

[0083]

[Assessment of thickness and air tightness]

The thickness T1 of the mask sheet of Examples and the airtightness of the mask sheet of Examples and Comparative Example were determined according to the methods described above. The results are shown in Table 1.

[0084]

[Evaluation of fine particle collection rate]

The degree of capture of fine particles by the mask sheets of Examples and Comparative Example was determined by the following method.

When using a hand-held airborne particle counter (MET ONE HHPC6+; manufactured by Beckman Coulter Co., Ltd.), the sheet was fixed so as to cover the measuring tip of the counter with the mask sheet to be evaluated. Thereafter, the number P1 of particles that passed in the sheet thickness direction was determined for fine particles (with a particle diameter of 1.0 μm or more) in an atmosphere at 25° C. and a relative humidity of 50%. Separately, the number of P2 particles was determined without placing sheets. From the determined numbers of P1 and P2 particles, the degree (%) of capturing fine particles was calculated by the formula below. The higher the degree of capture of fine particles, the higher the ability of the mask sheet to capture fine particles. The evaluation results are shown in Table 1.

Fine particle collection rate (%) = 100 × (P2-P1) / P1

[0085]

[Usability rating]

The usability of the mask sheets of the Examples and the Comparative Example was evaluated by the following method in consideration of the following items (1) and (2). The results are shown in Table 1. The mask sheet used for evaluating the usability was converted into a simple mask form by using rubber bands or the like for earloop portions in an area other than the mouth area of the mask sheet. The masks were put on the test participants and evaluated.

[0086]

(1) Ease of breathing

A total of five trial participants, men and women aged 20 to 30 years and 30 to 40 years, were asked to wear mask sheets, and the ease of breathing was assessed according to the criteria below. The score was the value in points corresponding to the score chosen most often.

3 points: When wearing a mask, one can breathe without difficulty, and there is a high degree of usability.

Score 2: The user experiences some breathing difficulties while wearing the mask, but there are no usability issues.

1 point: It is possible to breathe while wearing the mask, but the usability is reduced to such an extent that it is difficult to wear the mask for a long time.

[0087]

(2) Feeling when wearing

A total of five test participants, men and women aged 20 to 30 years and 30 to 40 years, were asked to wear mask sheets, and the wearing sensation was evaluated according to the criteria below. The score was the value in points corresponding to the score chosen most often.

3 points: The mask sheet can be worn without feeling hard or thick when gripped or worn, and has a high degree of usability.

Score 2: Although the user feels the hardness and thickness of the mask sheet slightly when gripping or wearing the mask sheet, there are no problems associated with usability.

1 point: The user easily feels the hardness and thickness of the mask sheet when gripping or wearing the mask sheet, and the usability is reduced to such an extent that the mask sheet feels uncomfortable when worn for a long time.

[0088]

[Table 1]

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Mask sheet configuration Weight of the base M1 of the first fibrous layer (g/m ² ) 2.5 3.0 5.0 5.0 10.0 15.0 3.5 4.0 4.5 30.0 Base weight M2 of the second fibrous layer (g/m ² ) eighteen eighteen eighteen eighteen eighteen eighteen eighteen eighteen eighteen 40 Base weight M3 of the third fibrous layer (g/m ² ) eighteen eighteen eighteen eighteen eighteen eighteen eighteen eighteen eighteen thirty The average diameter of the fibers constituting the fibers of the first fibrous layer (µm) 0.5 0.5 0.5 0.8 0.8 0.8 0.5 0.5 0.5 2.5 M2/M1 7.2 6.0 3.6 3.6 1.8 1.2 5.1 4.3 4.0 1.3 M3/M1 7.2 6.0 3.6 3.6 1.8 1.2 5.1 4.3 4.0 1.0 Percentage of the area of the connected part to the area of the zone corresponding to the mouth (%) 0.076 0.076 0.076 0.076 0.076 0.076 0.076 0.076 0.076 - Thickness T1 sheet (mm) 0.47 0.42 0.49 0.56 0.60 0.63 0.40 0.39 0.41 0.93 Air tightness (kPa×s/m) 0.19 0.29 0.56 0.14 0.29 0.37 0.39 0.44 0.50 0.66 Fine particle collection rate (%) 81 88 93 56 84 93 93 94 96 87 Ease of breathing 3 3 2 3 3 3 3 3 3 2 Feeling when wearing 3 3 3 3 3 2 3 3 3 2

[0089]

As shown in Table 1, it can be seen that the mask sheet 10 of the present example has a very good foreign matter trapping ability in the form of fine particles, is formed thin, has a good air permeability, and accordingly has a high degree of usability.

In particular, it can be seen that the mask sheets of Examples 1 and 2, more preferably the mask sheet of Example 2 are sheets which are characterized by a combination of a high degree of trapping of foreign substances in the form of fine particles, reduced airtightness and high usability score. .

List of reference positions

[0090]

one mask 5 the main part of the mask ten mask sheet 10A, 10V, 10C wound element eleven first fibrous layer 12 second fibrous layer thirteen third fibrous layer fifty packing bag 80 package 100 production device BUT zone corresponding to the mouth AT connected part With perforation

Claims (14)

1. A mask sheet comprising a first fibrous layer, which is a nonwoven material made by electrospinning, and a second fibrous layer, provided on the side of one surface of the first fibrous layer, and the second fibrous layer is a nonwoven material, while the average diameter of the fibers, which are the fibers forming the second fibrous layer are larger than the average diameter of the fibers constituting the fibers constituting the first fibrous layer, the average diameter of the fibers constituting the fibers constituting the first fibrous layer is 0.5 μm-0.8 μm, the weight of the warp of the first fibrous layer is 2.5 g/m ² -15 g/m ² and the ratio of the weight of the base of the second fibrous layer to the weight of the base of the first fibrous layer is less than 8, and the first fibrous layer is configured to capture fine particles. 2. The mask sheet according to claim 1, wherein the mask sheet has an air permeability of less than 0.5 kPa*s/m. 3. The mask sheet according to claim 1, wherein the first fibrous layer and the second fibrous layer are bonded in joined portions, and wherein the joined portions are formed by fusion bonding. 4. The mask sheet according to claim 1, in which the first fibrous layer and the second fibrous layer are connected in the connected parts, and the average area of each of the connected parts is 0.1 mm ² -3 mm ² . 5. The mask sheet according to claim 1, wherein the basis weight of the second fibrous layer is 5 g/m ² -30 g/m ² . 6. The mask sheet according to claim 1, wherein the nonwoven fabric of the second fibrous layer is a nonwoven fabric bonded by passing air through. 7. The mask sheet according to claim 1, wherein the nonwoven fabric of the second fibrous layer is an air laid nonwoven fabric. 8. The mask sheet according to claim 1, wherein the nonwoven material of the second fibrous layer is a spunbond nonwoven material. 9. The mask sheet according to claim 1, wherein the nonwoven fabric of the second fibrous layer is a hydroentangled nonwoven fabric. 10. The mask sheet of claim 1, wherein the nonwoven fabric of the second fibrous layer is a meltblown nonwoven fabric. 11. The mask sheet according to claim 1, wherein the nonwoven fabric of the second fibrous layer is a nonwoven fabric obtained by needling. 12. The mask sheet according to claim 1, in which the third fibrous layer is further provided on the side of that surface of the first fibrous layer from which the second fibrous layer is not located, and the average diameter of the fibers, which are the fibers forming the third fibrous layer, is greater than the average diameter of the fibers , which are the fibers that form the first fibrous layer. 13. The mask sheet according to claim 1, wherein the third fibrous layer is further provided on the side of that surface of the first fibrous layer from which the second fibrous layer is not located, and the outer surface of the second fibrous layer or the outer surface of the third fibrous layer faces the wearer's mouth. 14. The mask sheet according to claim 1, in which the mask sheet has a mouth area located in accordance with the position of the user's mouth in plan view, while the mouth area has at least one connected part connecting the first fibrous layer and a second fibrous layer, in the range of 20 mm×20 mm in the area corresponding to the mouth in plan view, and the total area of the connected parts is less than 2% of the area corresponding to the mouth in plan view.

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