mask

Abstract

To provide a superior mask which is excellent in adhesion to a face and wearing feeling, especially cool feeling, and does not lose a shape even when repeatedly attached / detached.SOLUTION: A mask is formed of one layer of a polyurethane elastic non-woven fabric, and includes a center part 2 and ear engaging parts 3. In openings 4 provided in the ear engaging parts 3, first opening portions 5 positioned on a centermost side of the mask are each in a substantially isosceles triangle shape with an apex angle facing the center side of the mask, second opening portions 6 extending laterally from the first opening portions 5 are each in a rectangular shape with upper and lower opening edges extending parallel to each other, and third opening portions 7 extending laterally from the second opening portions 6 are each in an approximately circular shape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mask that is comfortable to wear, has excellent adhesion, and does not easily lose its shape even after repeated use. [Background technology]

[0002] In general, masks that cover the nose and mouth are widely used to prevent infectious diseases, hay fever, etc. A wide variety of such masks have been proposed according to needs, and the following, for example, are known as disposable masks made of nonwoven fabric sheets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-114080 [Patent Document 2] Japanese Utility Model Application Publication No. 60-113057 [Patent Document 3] Utility Model Registration No. 3172588 [Patent Document 4] JP 2005-95370 A Summary of the Invention [Problem to be solved by the invention]

[0004] The masks in Patent Documents 1 and 2 are made by cutting a nonwoven sheet into a predetermined shape, and integrally forming a mask part that covers the area from the nose to the mouth, and an engagement part that engages with the left and right ears. However, since the flat sheet is worn to fit the uneven face, if tightness is prioritized, the ears are heavily strained, and the area around the mouth is also tightly fitted, making it difficult to breathe. Furthermore, since the masks are intended to be disposable, there is a problem that the engagement parts with the ears easily stretch and deform, and when they deform, the fitting effect decreases.

[0005] On the other hand, the mask in Patent Document 3 does not fit the entire nonwoven fabric sheet to the face, but instead has wires in the upper and left and right edges of the mask, which is folded to give it a three-dimensional appearance, to improve its fit. However, not only is it time-consuming and costly to manufacture, but it is also time-consuming to wear the mask because the three wire parts must be aligned to the face. Furthermore, if the wire parts become distorted, they will no longer fit the face, making it difficult to reuse the mask once it is removed.

[0006] The mask in Patent Document 4 aims to achieve both good adhesion and comfortable wearability by using a special nonwoven fabric sheet with excellent elasticity. However, the holes for engaging with the ears are long and thin, so there is a feeling of tension. In addition, there is a problem that the area of ​​the part that covers the cheeks is large, so there is a lack of cooling sensation, and improvements in these areas are required.

[0007] The present invention has been made in consideration of the above circumstances, and has as its object to provide an excellent mask which adheres well to the face, is comfortable to wear, does not cause pain behind the ears in particular, and does not lose its shape even when put on and taken off repeatedly. [Means for solving the problem]

[0008] In order to achieve the above object, a first gist of the present invention is a mask made of a single layer of elastic polyurethane nonwoven fabric and used to cover the nose and mouth, the mask comprising a central portion that covers the nose and mouth when worn, and a pair of left and right ear engagement portions that extend laterally from the central portion and engage with the ears when worn, each of the pair of left and right ear engagement portions having an opening for ear engagement, the opening having a first opening portion that is located closest to the center of the mask and has a substantially isosceles triangular shape with an apex angle facing toward the center of the mask, a second opening portion extending laterally from the first opening portion has a rectangular shape with upper and lower opening edges extending parallel to each other, and a third opening portion extending laterally from the second opening portion has a substantially partial circular shape.

[0009] A second gist of the present invention is a mask in which a welded portion is provided along an imaginary center line P extending vertically through the center of the central portion, and a three-dimensional shape is imparted by the welded portion.A third gist of the present invention is a mask in which the dimension d of the welded portion in the width direction transverse to the longitudinal direction is 0.1 to 1.5 mm.

[0010] Among these, a fourth aspect of the present invention is a mask in which the angle θ at the apex corner of the first opening portion at the opening of the ear engagement portion is 30 to 80°, and a fifth aspect of the present invention is a mask in which the apex corner of the first opening portion at the opening of the ear engagement portion is rounded with a radius of curvature R1 of 1 to 10 mm.

[0011] Furthermore, a sixth aspect of the present invention is a mask in which, among these, at the opening of the ear engagement portion, the length dimension L1 extending to the left and right of the second opening portion is 20 to 40 mm, and the ratio (L1 / L0) of L1 to the total length L0 in the left and right direction when the mask is stretched flat on a plane is 0.05 to 0.14.A seventh aspect of the present invention is a mask in which, at the opening of the ear engagement portion, the radius of curvature R2 of the arc portion of the approximately partially circular shape of the third opening portion is 20 to 30 mm.

[0012] Furthermore, an eighth aspect of the present invention is a mask in which the elastic polyurethane nonwoven fabric has the following properties (1) to (4): (1) Weight: 60-120g / m 2 (2) Tensile strength in both the machine direction (MD) and cross direction (CD): 1000cN / 20mm or more (3) Tensile elongation in both the longitudinal and transverse directions: 300% or more (4) 100% elongation recovery rate in both the vertical and horizontal directions: 90% or more

[0013] And, in the eighth aspect of the present invention, a ninth aspect is a mask in which the polyurethane elastic nonwoven fabric further has the following properties (5) and (6): (5) Air permeability: 50cc / cm 2 / sec or more (6) Maximum heat absorption rate (Q-max): 0.08 or more Effect of the Invention

[0014] That is, since the mask of the present invention is entirely made of a single layer of elastic polyurethane nonwoven fabric, it has excellent elasticity and excellent wearing comfort and adhesion to the face. In addition, the openings for engaging with the ears on the ear engaging parts that extend to the left and right have a unique shape that has never been seen before, so the area around the mouth does not feel cramped and a tight fit is maintained. In addition, because the openings are large in the areas that overlap with the cheeks, there is no feeling of pressure from the mask fabric, and it has the advantage of providing a cool feeling even when the outside temperature is high. The effects of each part of the opening will now be described in more detail.

[0015] (1) Effect of the first opening portion of the opening being substantially isosceles triangular in shape The part that connects from the part that engages with the ears to the central part that covers the nose and mouth is divided into upper and lower parts by the first opening, so that the lower edge that touches the lower chin and the upper end that touches the nose are pulled left and right, respectively, and keep in close contact with the face, making it difficult for the fabric to slacken, while leaving the area near the center of the central part from the nose to the mouth unaffected, and allowing the mouth to open and close relatively freely, resulting in an excellent wearing comfort.

[0016] (2) The effect of the second opening part being rectangular The part of the mask that overlaps with the cheeks has a large rectangular opening, so the skin on the cheeks is not pressed by the mask fabric, making it comfortable to wear. It also prevents the mask from becoming stuffy, so you can feel cool even when the outside temperature is high.

[0017] (3) Effect of the third opening part of the opening being approximately partially circular The upper and lower ends of the approximate partial circle are connected to the upper and lower opening edges that extend in parallel to the second opening portion, and these opening edges that extend in the upper, lower, left and right directions expand and contract to maintain the mask's close contact with the face. The tensile stress generated by the upper and lower opening edges being pulled is dispersed by the arc-shaped opening edges that come into contact with the back of the ears, and is not concentrated at one point, so that the back of the ears is less likely to hurt.

[0018] Among the present invention, those in which a welded portion is provided along an imaginary center line P extending vertically through the center of the central portion and a three-dimensional shape is imparted by the welded portion are particularly preferable because the mask can easily conform to the contours of the face and more space is secured around the nose and mouth.

[0019] In the present invention, the welded portion has a width dimension d of 0.1 to 1.5 mm in the width direction transverse to the longitudinal direction, and the width dimension d of the welded portion is very small, so that the welded portion is not noticeable in the center of the front of the mask, resulting in a good appearance. In addition, the presence of the welded portion does not deteriorate the wearing comfort, and the welded portion is unlikely to damage the fabric during washing, which is preferable.

[0020] Furthermore, in the present invention, when the angle θ of the apex of the first opening is 30 to 80°, the pulling force applied to the ear engaging portion does not forcibly pull the portion connected to the center portion covering the nose and mouth in a diagonal direction, which is particularly preferable. Moreover, since the mask shape easily fits the face, there is no loose feeling and the fabric is less likely to become loose, making it more hygienic and aesthetically pleasing.

[0021] In the present invention, when the apex corner of the first opening is rounded with a radius of curvature R1 of 1 to 10 mm, even if the mask is used repeatedly, tensile stress is not concentrated at the tip of the apex corner, and this part is less likely to break. In addition, the shape of the apex corner is further suppressed, so that the mask as a whole does not lose its shape, which is preferable.

[0022] In the present invention, it is particularly preferable that the length dimension L1 extending to the left and right of the second opening portion in the opening of the ear engagement portion is 20 to 40 mm, since this reduces the burden on the ears. Moreover, it is preferable that the ratio (L1 / L0) of L1 to the total length L0 in the left and right direction when the mask is stretched flat on a plane is 0.05 to 0.14, since this reduces the feeling of pressure on the cheeks, and a cool feeling can be obtained even when the outside temperature is high.

[0023] In addition, in the present invention, it is particularly preferable that the radius of curvature R2 of the arc portion of the approximately partially circular shape of the third opening portion in the opening of the ear engagement portion is 20 to 30 mm, as this further reduces the burden on the ear.

[0024] In particular, among the polyurethane elastic nonwoven fabrics of the present invention, those in which each of the following properties is set within a prescribed range: (1) basis weight, (2) tensile strength in the longitudinal direction (MD) and transverse direction (CD), (3) tensile elongation in the longitudinal direction and transverse direction, and (4) 100% elongation recovery rate in the longitudinal direction and transverse direction, are set within a prescribed range, have better wearing comfort and adhesion to the face, and are therefore preferred.

[0025] Among the masks according to the seventh aspect, those in which the polyurethane elastic nonwoven fabric has the characteristics of (5) breathability and (6) maximum heat absorption rate (Q-max) set within a predetermined range are particularly suitable, as they are easier to breathe, less likely to become stuffy, and have an even improved cooling sensation. [Brief description of the drawings]

[0026] [Figure 1] 1 is a perspective view showing a mask according to an embodiment of the present invention; [Diagram 2] FIG. 1(a) is an explanatory diagram showing the mask when laid out flat, and FIG. 1(b) is an explanatory diagram showing one side of the mask when folded in half at the center. [Diagram 3] FIG. 2 is a plan view showing the polyurethane elastic nonwoven fabric used in the above mask cut for use in the mask. [Figure 4] FIG. 2A is a schematic explanatory diagram showing the shapes of the left and right openings of the mask, and FIGS. 2B and 2C are schematic explanatory diagrams showing modified examples of the opening shapes in the mask. [Diagram 5] 13 is an explanatory diagram showing still another modified example of the opening shape in the mask. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[0028] One embodiment of the mask of the present invention is shown in Figure 1. This mask is used to cover the nose and mouth, and is made by cutting a single layer of elastic polyurethane nonwoven fabric into a predetermined symmetrical shape and providing a welded part 1 along an imaginary center line P, which is the axis of symmetry, to give it a three-dimensional shape.

[0029] More specifically, the mask has a central section 2 that covers the nose and mouth when worn, and a pair of left and right ear engagement sections 3 that extend laterally from the central section 2 and engage with the ears when worn. Each of the pair of left and right ear engagement sections 3 has an opening 4 for engaging the mask with the ears.

[0030] The opening 4 has a first opening portion 5 located closest to the center of the mask, which is approximately an isosceles triangle with its apex facing toward the center of the mask, a second opening portion 6 extending laterally from the first opening portion 5, which is rectangular with upper and lower opening edges extending parallel to each other, and a third opening portion 7 extending laterally from the second opening portion 6, which is semicircular.

[0031] In addition, the welded portion 1 extends upward from a position (indicated by O in FIG. 1) that is approximately the center in the vertical direction of a center line P that extends vertically through the center of the central portion 2 of the mask, and the portion below the welded portion 1 is simply a fold (a so-called "loop").

[0032] When the above mask is laid flat on its sides, its planar shape is as shown in Figure 2(a). At this time, the part through which the imaginary center line P passes is bulged out to cover the nose area by the welded part 1, and this bulged part is shown folded over to the left (the bulged part is shown with diagonal lines S). Also, if the entire mask is folded in half along the center line P and placed with the right side facing up, it will look like the mask in Figure 2(b).

[0033] As can be seen from these figures, the left and right upper edge portions 8 extending from the central portion 2 toward the left and right ear engagement portions 3 are highest in the center and slope downward toward the vicinity of the boundary between the first opening portion 5 and the second opening portion 6 of the left and right openings 4. Similarly, the left and right lower edge portions 9 are lowest in the center and slope upward toward the vicinity of the boundary between the first opening portion 5 and the second opening portion 6 of the left and right openings 4.

[0034] The welded part 1 extending along the center line P of the central part 2 is curved in a gentle arc, and the folded part below the welded part 1 is naturally straight. In this way, when the upper part along the center line P where the welded part 1 is provided is curved in an arc, this part fits the nose and the mask is less likely to slip off. Also, when the lower part along the center line P is straight, the fabric does not slacken, and the mask is less likely to slip off the lower chin.

[0035] The above mask can be obtained, for example, as follows. First, a polyurethane elastic nonwoven fabric that is stretchable, breathable, and equipped with a specified filter function (such as pollen prevention or splash prevention) is prepared, and cut or fused into the shape shown in Fig. 3. This shape is symmetrical about a center line P, and a large cutout 10 is provided in the upper center so that after welding, the central portion will have a three-dimensional shape that bulges forward. By welding the curved edges on the left and right of this cutout 10, a mask with the shape shown in Figs. 1 and 2 can be obtained.

[0036] The mask obtained in this way is entirely made of a single layer of polyurethane elastic nonwoven fabric, so it has excellent elasticity, comfort when worn, and excellent adhesion to the face. In addition, because the central portion 2 bulges forward, there is space from the nose to the mouth, making it easy to breathe and move the mouth.

[0037] In particular, in the opening 4 for engaging with the ear, the first opening portion 5 is shaped like an isosceles triangle with the apex angle facing toward the center, so that the portion continuing from the ear engaging portion 3 to the central portion 2 covering the nose and mouth is divided into upper and lower portions by the first opening portion 5. With this configuration, the lower edge portion 9 that contacts the lower jaw and the upper end portion 8 that contacts from the nose to the cheeks are pulled in the left and right directions, respectively, maintaining a tight fit to the face, while the central portion between them, from the nose to the mouth, is less susceptible to the effects of the pulling force, providing an advantage in that there is more space around the mouth in particular.

[0038] In addition, the second opening 6 of the opening 4 is rectangular and the part that overlaps with the cheek is open widely, so the skin of the cheek is not pressed by the mask fabric, making it more comfortable to wear. And because the contact area with the mask fabric is small, it is less likely to get stuffy, and has the advantage of providing a cool feeling even when the outside temperature is high.

[0039] Furthermore, the third opening portion 7 of the opening 4 is semicircular, and the semicircular opening edge portion is connected to the upper and lower opening edge portions extending in parallel of the second opening portion 6. Therefore, even if the semicircular opening edge portion that touches the back of the ear is pulled as the upper and lower opening edges expand and contract, the pulling force is distributed to each part of the semicircular shape and is not concentrated at one point, so that the back of the ear is less likely to hurt.

[0040] The polyurethane elastic nonwoven fabric used in the mask is a nonwoven fabric made of polyurethane elastic fibers. Polyurethane elastic fibers are more flexible than other fibers such as polypropylene, and have a high thermal conductivity, which has the advantage that heat is less likely to build up inside the mask.

[0041] The polyurethane elastic nonwoven fabric does not have to be entirely made of polyurethane elastic fibers, and may be partially replaced with other fibers. However, in order to ensure the elasticity and flexibility required for a mask, if other fibers are used, it is desirable to set the proportion of such fibers to 10% by mass or less of the total fibers.

[0042] The thickness of the polyurethane elastic fibers used in the polyurethane elastic nonwoven fabric is not particularly limited, but in consideration of the pollen and droplet removal performance, it is desirable that the fiber diameter be as small as possible so that dense air holes can be formed, and in consideration of the overall strength, elasticity, breathability, etc., the average fiber diameter is 25 μm or less, preferably 5 to 15 μm, and more preferably 8 to 12 μm.

[0043] Furthermore, in order to obtain a good wearing comfort and sufficient adhesion, it is particularly preferable that the above-mentioned polyurethane elastic nonwoven fabric has the following properties (1) to (4). (1) Weight: 60-120g / m 2 , especially 80~120g / m 2 , and even 90-110g / m 2 (2) Tensile strength in both the machine direction (MD) and cross direction (CD): 1000cN / 20mm or more In particular, the longitudinal tensile strength is 1200cN / 20mm or more, or even 1600cN / 20mm or more. In particular, the tensile strength in the transverse direction (CD direction) is 1600cN / 20mm or more, or even 1800cN / 20mm or more. (3) Tensile elongation in both the longitudinal and transverse directions: 300% or more, especially 350-520% (4) 100% elongation recovery rate in both the vertical and horizontal directions: 90% or more in both directions, especially 94-100%

[0044] The above "tensile strength" and "tensile elongation" are values ​​measured in accordance with JIS L1913:2010 6.3.1, and the above "100% elongation recovery" is a value measured in accordance with JIS L1096:2010 8.16.2.

[0045] In order to obtain a better wearing feeling, it is preferable that the polyurethane elastic nonwoven fabric further has the following properties (5) and (6). The upper limit of the air permeability is appropriately set depending on the required filter performance, etc. The maximum heat absorption rate (Q-max) is an index of the degree of coolness felt when touched, and the higher the value, the stronger the coolness felt, which is preferable. (5) Air permeability: 50cc / cm 2 / sec or more (6) Maximum heat absorption rate (Q-max): 0.08 or more, especially 0.10 or more

[0046] The above "breathability" is a value measured in accordance with JIS L1913:2010 6.8.1 Frazier method, and the above "maximum heat absorption rate (Q-max)" is a value measured in accordance with JIS L1927:2020.

[0047] The polyurethane elastic nonwoven fabric having such characteristics is most preferably obtained by the melt blowing method. To explain this method in more detail, for example, a spinning device described in JP-B-41-7883 is used, and a thermoplastic polyurethane elastomer is melt-discharged from the spinneret, and an accelerated gas flow is sprayed from both sides of the nozzle to thin the filaments. The thinned filaments are separated from the gas flow and stacked on a collecting device such as a moving conveyor net, and are cooled and solidified while being bonded at their contact points. Of course, after being cooled and solidified on the collecting device, the filaments may be bonded by heating and pressing using a roller or the like. The polyurethane elastic nonwoven fabric obtained in this way has a structure in which thin continuous filaments of polyurethane elastic fiber are randomly stacked, and therefore has excellent breathability, dense filter function, high stretchability, and flexibility.

[0048] The polyurethane elastic nonwoven fabric may be one that has been given antibacterial or bactericidal properties. The one that has been given antibacterial properties is hygienic as it inhibits the growth of various bacteria. The one that has been given bactericidal properties can prevent the invasion of bacteria from the outside, and therefore can be used for special purposes.

[0049] Furthermore, the polyurethane elastic nonwoven fabric may be made electrically conductive. By making the mask electrically conductive, static electricity does not build up, so that the mask is more hygienic and does not attract dust or dirt.

[0050] The mask of the present invention is resistant to deformation due to its material and shape. Therefore, it is suitable for repeated use after washing rather than disposable. Therefore, it is desirable that the shape of the polyurethane elastic nonwoven fabric after, for example, 10 home washings (in accordance with JIS L1930:2014 C4M method) does not change as much as possible compared to the shape before washing.

[0051] In the above example, the welded part 1 is provided along the imaginary center line P that extends vertically through the center of the central part 2 of the mask, and the welded part 1 gives the mask a three-dimensional shape, but the welded part 1 is not necessarily required. That is, even if the mask is made of a single flat piece of fabric (elastic polyurethane nonwoven fabric), the elasticity of the polyurethane nonwoven fabric is good, and as described above, the shape of the openings 4 provided in the ear engagement parts 3 on both sides of the mask is special, so even if the welded part 1 is not provided, the upper edge 8 of the mask is pressed against the part that crosses the nose, and the lower edge 9 of the mask is pressed against the chin, so that the central fabric from the nose to the mouth is pushed forward, creating a gap. As a result, the mask periphery fits closely along the contours of the face, just like a three-dimensional mask, and the mask is roomy in the center and comfortable to breathe in.

[0052] In addition, when the welding part 1 is provided as in the above example, the degree of freedom of the fabric in the space around the mouth is easily influenced by the arrangement of the arc-shaped upper part 15 where the welding part 1 is provided and the linear lower part 16 below it, so it is preferable that the arc-shaped upper part 15 passes from the nose to the mouth in a vertical direction [see FIG. 2(b)]. And it is preferable that the linear lower part 16 reaches the chin from below the mouth. For this purpose, it is preferable that the ratio (A / B) of the length dimension A of the upper part 15 to the length dimension B of the lower part 16 is 4 / 6 to 6 / 4, and more preferably 4.3 / 5.7 to 5.7 / 4.3. In other words, it is preferable that the position O, which is the switching point between the upper part 15 and the lower part 16, is located near the center in the vertical direction of the fold part.

[0053] In the above example, when the welding part 1 is provided at the center of the mask, even if the welding part 1 is not made rigid to function as a rib, the fabric in the center from the nose to the mouth is pushed forward as described above, so that it is not necessary to set the width dimension d [see FIG. 2(b)] of the welding part 1 across the longitudinal direction to be wide. That is, by providing the welding part 1, the fabric can be welded to obtain a more stable three-dimensional effect, but since high rigidity as a rib is not required, the width dimension d is preferably set to, for example, 2 mm or less, and especially 0.1 to 1.5 mm. In this way, by making the width dimension of the welding part 1 very narrow, the welding part 1 is not noticeable at the center of the mask, resulting in a good appearance. In addition, since the welding part is not stiff, excellent wearing comfort and coolness can be obtained, together with the size of the ear engagement opening 4.

[0054] In addition, when the welded portion 1 is provided, it is preferable that the welded portion 1 is formed in the region from the center of the mask to the upper half region as in the above example. In that case, the edge portion that becomes the welded portion 1 may be linear, but as shown in the above example, it is preferable that it is curved in an arc shape, and the radius of curvature R3 [see FIG. 2(b)] of the arc shape is usually set to 100 to 150 mm, and preferably 120 to 135 mm, depending on the longitudinal dimension of the welded portion 1. In other words, by making the welded portion 1 an arc shape with a moderate radius of curvature rather than a straight line, the three-dimensional bulging shape from the nose to the mouth is controlled, improving the wearing comfort and the adhesion.

[0055] The straight line portion below the welded portion 1, which was not welded in the above example, may also be welded to form a continuous welded portion 1 from the top to the bottom. Alternatively, the arc-shaped upper welded portion 1 and the straight lower welded portion may be provided with a space between them, with the fold remaining unwelded. When forming a continuous welded portion 1 from top to bottom, it is not necessary to fold a single nonwoven fabric in half and weld the fold, but it is also possible to overlap a pair of left and right nonwoven fabrics and weld the overlapping edges.

[0056] In the above example, the angle θ [see FIG. 2(b)] at the apex of the first opening 5 of the opening 4 of the ear engagement part 3 is appropriately set, but is preferably 30 to 80°, more preferably 40 to 70°, and particularly preferably 50 to 65°. That is, if the angle θ is too large, the effect of dividing the pulling force generated from the ear engagement part 3 toward the central part 2 of the mask into upper and lower parts and suppressing the influence on the central part 2 is reduced, which is not preferable. If the angle θ is too small, the upper and lower widths of the ear engagement part 3 must be reduced or the width W of the fabric at the ear engagement part 3 (the width between the outline edge of the ear engagement part 3 and the edge of the opening, see FIG. 3) must be increased, which is not preferable because it may cause a poor wearing comfort around the ears.

[0057] Similarly, in the opening 4 of the ear engagement portion 3, it is not essential to provide a radius at the apex corner of the first opening portion 5. However, if no radius is provided at this portion, the fabric at this portion may stretch and become loose or tear after repeated use and washing, so it is desirable to provide a radius. The radius of curvature R1 (see FIG. 3) of the radius is preferably 1 to 10 mm, and more preferably 2 to 5 mm. If the radius is too large, the effect of dividing the tensile force on the fabric into upper and lower portions due to the approximately isosceles triangular shape of the first opening portion 5 becomes weak, which is undesirable.

[0058] In the above example, the apex corners of the first opening portion 5 are arranged so as to face each other toward the center line P of the mask. However, in the present invention, the state in which "the apex corners face toward the center of the mask" does not necessarily mean that the apex corners are arranged so as to face perpendicular to the center line P of the mask, as shown in FIG. 4(a). For example, it is intended to include an arrangement in which the apex corners are arranged slightly downward with respect to the center line P, as shown in FIG. 4(b), or an arrangement in which the apex corners are arranged slightly upward with respect to the center line P, as shown in FIG. 4(c).

[0059] However, the shape of the apex angle shown in Figures 4(b) and (c) is tilted at a large angle for the purpose of explanation. In reality, if the direction in which the apex angle bisector D in Figure 4(a) extends is taken as 0°, then in Figures 4(b) and (c), each of the bisectors D1 and D2 should be inclined by within ±10°, which is preferable in order to prevent sagging in the mask.

[0060] In the state shown in Figure 4(b) or the state shown in Figure 4(c), the first opening portion 5 is not "isosceles triangular" and one side of the apex angle is slightly longer than the other side, but in the present invention, these shapes are also included in the "approximately isosceles triangular" shape.

[0061] Similarly, the length dimension L1 [see FIG. 2(a)] extending left and right of the second opening portion 6 in the opening 4 of the ear engagement portion 3 is usually set to 20 to 40 mm, although it depends on the size of the entire mask. The ratio (L1 / L0) of L1 to the total mask length L0 in the left and right direction when the mask is stretched flat on a plane [as shown in FIG. 2(a)] is preferably 0.05 to 0.14, more preferably 0.085 to 0.12, and even more preferably 0.09 to 0.11. That is, if the ratio (L1 / L0) is too small, the opening of the second opening portion 6 may become narrow, causing a feeling of pressure, whereas if it is too large, the ear engagement portion 3 may become too long or the central portion 2 may become too short in the left and right direction, causing the overall balance to be poor.

[0062] Similarly, in the above example, the third opening 7 of the opening 4 of the ear engagement portion 3 is semicircular (a partial circle with a central angle of 180°), but it does not necessarily have to be semicircular, and may be a partial circle with a central angle θ' smaller than 180°, as shown in FIG. 5. However, in order to enlarge the opening of the third opening 7 to provide a comfortable fit, particularly a cool feeling, and to avoid discomfort when engaging with the ear, it is preferable to set the radius of curvature R2 (return to FIG. 3) of the arc portion in the partial circle shape to be usually 20 to 30 mm, and more preferably 23 to 28 mm, taking into account the comfort when engaging with the ear, although there is a balance with the central angle.

[0063] Furthermore, the third opening 7 does not need to be a partial circle of a perfect circle as described above, but may be an ellipse slightly crushed in the vertical direction, an ellipse slightly crushed in the horizontal direction, or an approximation of a circle that is not an ellipse but is different from a perfect circle. In the present invention, these are collectively called "approximately partial circles". That is, in the mask of the present invention, it is important that the opening shape of the third opening is an approximately partial circle without corners in order to obtain a comfortable fit and a cool feeling when engaging with the ears.

[0064] In addition, as described above, when the third opening portion 7 is not a partial circle of a perfect circle, the "radius of curvature R2 of the arc portion" refers to the radius of curvature R2 at a position in the arc portion of the third opening portion 7 opposite the apex angle of the first opening portion 5.

[0065] The width W of the ear-hanging portion 3 (shown by the diagonal line T in FIG. 3) narrowed by the opening 4 depends on the contour shape of the mask and the shape of the opening 4. To obtain a comfortable fit when hanging on the ear, it is preferable that the width W is approximately the same in all parts. In particular, it is preferable that the contour is approximately parallel to the curve of the third opening 7, so that the mask is less likely to tear or hurt the ear when hanging on the ear due to localized stress concentration. The width W is usually preferably 3 to 15 mm, and is preferably set to 5 to 15 mm, and more preferably 8 to 12 mm. If the width W is too large, this portion may twist and the fit to the ear may be reduced. Conversely, if the width W is too small, it is not preferable because the mask will hit the ear or cheek too hard, reducing the fit or making the mask more likely to tear. EXAMPLES

[0066] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples.

[0067] First, four types of polyurethane elastic nonwoven fabrics A to D with different physical properties were prepared as mask fabrics. The physical properties of each nonwoven fabric are shown in Table 1 below. The polyurethane elastic nonwoven fabrics A to C are made by melt-blowing a polyurethane elastomer made of diphenylmethane diisocyanate, polyol, and 1,4-butanediol. The polyurethane elastic nonwoven fabric D is the polyurethane elastic nonwoven fabric described in JP 2005-95370 A.

[0068] [Table 1]

[0069] In Table 1 above, "Pollen prevention performance (removal rate)" is a value calculated in accordance with the method specified by the National Mask Industry Association of the Japan Sanitary Materials Industry Association as the "Pollen particle collection (filtration) efficiency test method."

[0070] [Examples 1 to 6, Comparative Examples 1 to 3] Using the nonwoven fabrics A to D, nine types of masks (Examples 1 to 6, Comparative Examples 1 to 3) having the characteristics shown in Tables 2 and 3 were produced. The masks were arranged so that the longitudinal direction was the transverse direction (CD direction) of the nonwoven fabric, and a high-frequency welder was used to first melt-cut the fabric shape that would become the mask (see FIG. 3), and then, with the fabric folded in half and overlapping, melt-cutting and welding were performed on the parts to be melted (notch 10 in FIG. 3). Comparative Example 1 is a disposable mask having the shape shown in FIG. 1 of JP 2005-95370 A, and the physical properties of the fabric are based on the values ​​shown in Example 1 of the above publication. Comparative Example 2 is a mask similar to Example 1, except that the first opening portion of the opening is semicircular like the third opening portion. Comparative Example 3 is a mask similar to Example 1, except that the second opening portion of the opening is not provided, and the approximately isosceles triangular opening of the first opening portion is extended horizontally and connected to the third opening portion.

[0071] These example products and comparative example products were evaluated for the following items according to the procedures below, and the results are shown in Tables 2 and 3 below.

[0072] [Wearing comfort, etc.] Eleven monitors were asked to wear each mask for a day from 10am to 6pm, except when eating or drinking, and were asked to evaluate the masks on a four-point scale, with ◎...very good, ○...good, △...average, ×...bad, for four categories: fit to the face, comfort of the ear loop, freedom of movement around the mouth when opening and closing, and coolness to the face. The most common rating was recorded as the rating. If the ratings of the same number of people were tied, the tied ratings were re-evaluated by all participants.

[0073] [Washability (whether or not the shape is lost)] In accordance with the JIS L1930:2014 C4M method, after 10 home washes, the garments were visually observed for deformation and rated on a 4-point scale: ◎: no deformation at all, ○: almost no deformation, △: some parts have lost their shape upon close inspection, ×: deformation is immediately apparent.

[0074] [Table 2]

[0075] [Table 3]

[0076] From the above results, it is seen that all of the example products have a good wearing feeling, a cool feeling, etc., and do not lose their shape even after 10 home washes, and can be used repeatedly with good results. On the other hand, the opening of the ear hook of the comparative example 1 is narrow, which hurts the ears and does not feel cool. In addition, it is assumed to be disposable, and the shape around the welded part is easily distorted. In addition, the opening shape of the ear hook of the comparative example 2 and 3 is different from the configuration of the present invention, so it is found that the wearing comfort is inferior to the example product. [Industrial Applicability]

[0077] The present invention can be widely used as a reusable mask that combines excellent adhesion and comfort, does not feel oppressive to the face, and has an excellent cooling sensation. [Explanation of symbols]

[0078] 2 Central part 3 Ear engagement part 4 aperture 5 First opening part 6 Second opening part 7 Third opening part

Claims

1. A mask made of a single layer of polyurethane elastic nonwoven fabric and used to cover the nose and mouth, The mask has a central portion that covers the nose and mouth when worn, and a pair of left and right ear engagement portions that extend laterally from the central portion and engage with the ears when worn, A welded portion is provided along an imaginary center line P extending vertically through the center of the central portion, and a three-dimensional shape is imparted by the welded portion, The welded portion extends upward from a position that is approximately the center of the center line P in the up-down direction, In the central portion of the mask, a ratio (A / B) of a dimension A of an arc-shaped upper portion having a welded portion along the center line P to a dimension B of a linear lower portion therebelow is 4 / 6 to 6 / 4; Each of the pair of left and right ear engagement portions is provided with an opening for ear engagement, The opening has a first opening portion located closest to the mask center and having a substantially isosceles triangular shape with an apex angle facing the mask center, a second opening portion extending laterally from the first opening portion and having a rectangular shape with upper and lower opening edges extending parallel to each other, and a third opening portion extending laterally from the second opening portion and having a substantially partial circular shape, The mask is characterized in that at the opening of the ear engagement portion, the length dimension L 1 extending to the left and right of the second opening portion is 20 to 40 mm, and the ratio (L 1 / L 0 ) of L 1 to the total length L 0 in the left and right direction when the mask is stretched flat on a plane is 0.05 to 0.

14.

2. 2. The mask according to claim 1, wherein the welded portion has a width dimension d of 0.1 to 1.5 mm in a width direction transverse to the longitudinal direction.

3. 3. The mask according to claim 1, wherein the angle θ at the apex of the first opening portion at the opening of the ear engagement portion is 30 to 80 degrees.

4. At the opening of the ear engagement portion, a radius of curvature R is provided at the apex of the first opening portion. 1 The mask according to any one of claims 1 to 3, wherein the mask has a radius of 1 to 10 mm.

5. In the opening of the ear engagement portion, the radius of curvature R of the arcuate portion of the substantially partially circular third opening portion 2 The mask according to any one of claims 1 to 4, wherein the thickness is 20 to 30 mm.

6. The mask according to any one of claims 1 to 5, wherein the polyurethane elastic nonwoven fabric has the following characteristics (1) to (4). (1) Weight: 60 to 120 g / m 2 (2) Tensile strength in the machine direction (MD) and cross direction (CD): both 1000 cN / 20 mm or more (3) Tensile elongation in both the longitudinal and transverse directions: 300% or more (4) 100% elongation recovery rate in both the vertical and horizontal directions: 90% or more

7. The mask according to claim 6, wherein the polyurethane elastic nonwoven fabric further has the following characteristics (5) and (6). (5) Air permeability: 50 cc / cm 2 / sec or more (6) Maximum heat absorption rate (Q-max): 0.08 or more

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