JP7492425B2 - mask - Google Patents

Description

The present invention relates to a mask that can be washed repeatedly.

In recent years, the demand for masks has increased due to the spread of infectious diseases such as influenza and viral pneumonia around the world. Common masks are surgical masks made of laminated nonwoven fabric and cloth masks. Since surgical masks are disposable, waste is increasing and is becoming an environmental problem.

On the other hand, cloth masks can be washed and reused, but because they are often made of cotton gauze fabric, they have problems such as shrinking and thickening after repeated washing. Also, because cloth masks have no firmness, they stick to the face when worn for long periods of time, feel stuffy when worn, and have problems with the ear straps rubbing against the ears and causing pain.

The applicant has proposed in Patent Document 1 a filter material for masks that combines sufficient breathability and capture rate, and is also highly durable to washing. However, when using such a filter material, it is difficult to improve both the shape retention of the mask and the wearing comfort on the face side, and when imparting antibacterial and antiviral properties, the three-dimensional fiber structure that is the filter material itself is subjected to antibacterial and antiviral processing, which creates the problem that the antibacterial and antiviral properties deteriorate with repeated use and washing.

JP 2002-212865 A

The objective of the present invention is to provide a mask that has shape retention that allows it to maintain appropriate gaps, does not stick to the face when breathing, is easy to breathe through, is less stuffy, uses highly elastic fabric so that the ears do not hurt even when worn for long periods of time, and has good dimensional stability even after repeated washing.

The present invention is a mask comprising an inner layer on the face side, an outer layer on the opposite side to the face, and a filter layer placed between the inner layer and the outer layer, the inner layer being a three-dimensional warp knitted fabric, the ground fabric on the face side mainly containing fibers selected from the group consisting of nylon-based fibers, cotton, rayon, and cupra, the ground fabric on the opposite side to the face mainly containing polyester-based fibers, at least the surface on the face side being mesh-like, the outer layer being a double knit fabric knitted by plating with elastic yarn and inelastic yarn, ear loops being formed without sewing by extending the double knit fabric, the filter layer being a nonwoven fabric, and the mask being removable.

It is also preferable that the double knit fabric has an elongation percentage of 180% or more and an elongation recovery percentage of 92% or more.
It is also preferable that the double knit fabric is made of a non-elastic yarn and an elastic yarn having a heat deformation starting temperature of 150 to 190°C.

The present invention provides a mask that has shape retention that allows it to maintain appropriate gaps, does not stick to the face when breathing, is easy to breathe through, is less stuffy, uses highly elastic fabric that is less likely to cause ear pain even when worn for long periods of time, and has good dimensional stability even after repeated washing.

FIG. 1 is a schematic diagram showing a mask according to an embodiment of the present invention. FIG. 2 is a schematic enlarged cross-sectional view showing the center of a mask of the present invention. FIG. 4 is a schematic diagram illustrating a filter storage section. FIG. 2 is an organizational diagram of Example 1. FIG. 11 is an organizational diagram of Example 2. FIG. 1 is a structural diagram of Comparative Example 1. FIG. 1 is a structural diagram of Comparative Example 2.

The mask of the present invention will be described below with reference to the drawings. However, the present invention is not intended to be limited to the configuration described below. In the drawings, the layers constituting the mask of the present invention are shown, but the thickness and size of each layer have been appropriately changed to facilitate explanation, and do not accurately reflect the actual size relationship (scale) of the thickness.

As shown in Figure 1, the mask 1 of the present invention has an inner layer 4 and an outer layer 5 that extends from the mask center section 2 and has ear loops 3 made of the same fabric. The mask center section 2 is provided with the inner layer 4 on the face side, the outer layer 5 on the side opposite the face, and a removable filter layer 6 (see Figure 3) between the inner layer 4 and the outer layer 5. Note that the outer layer is shown in the figure so that the arrangement of the inner layer 4 can be seen. A schematic enlarged cross-sectional view of the mask center section 2 is shown in Figure 2.

The inner layer 4 is a three-dimensional warp knitted fabric having at least a mesh-like surface on the face side, and the three-dimensional warp knitted fabric is a three-dimensional warp knitted fabric having at least two ground structures, a face side ground structure and an other side ground structure, and a connecting portion as necessary, for example, a double raschel knitted fabric. The double raschel knitted fabric is preferable because it has excellent shape retention.
In a three-dimensional warp knitted fabric, the facial side ground fabric and the other side ground fabric can be made of different materials, so the facial side ground fabric can be made of a material with a good texture, as described below, and the other side ground fabric can be made of a polyester-based fiber with excellent shape retention.

The facial side ground fabric and the other side ground fabric may be made of multifilament or spun yarn.
The material constituting the face side fabric mainly includes a fiber selected from the group consisting of nylon-based fibers such as nylon 6 and nylon 66, cotton, rayon, and cupra. These may be used alone or in combination of two or more. Among them, nylon-based fibers and cupra are preferred because of their good texture and feel, and nylon-based fibers that are versatile are more preferred. On the other hand, cupra is preferred if you want to improve the feel when wearing.
When two or more types are used in combination, they may be combined in a composite yarn or in an arrangement. Examples of composite yarns include, but are not limited to, ply-twisted yarns, mixed fiber yarns, blended yarns, covering yarns, and aligned yarns.

The face side ground fabric of the three-dimensional warp knitted fabric is mesh-like. In the mesh-like ground fabric of the present invention, adjacent wale rows are partially branched off, and after knitting multiple courses, the branched wale rows are rejoined to form openings. In other words, the term "mesh-like" means that openings are formed, and the opening rate is 1% or more.

The opening shape of the face-side ground tissue can be any shape, such as a polygonal shape such as a hexagonal shape or a square shape, a substantially circular shape, an elliptical shape, etc. The opening rate is preferably 8 to 40%, and more preferably 10 to 25%. If it is 8 to 40%, it is preferable because it is excellent in breathability and easy to suppress stuffiness.
In the present invention, the opening rate (H) of the mesh is calculated as follows. Using an image analyzer (VHX-200) manufactured by Keyence Corporation, a magnified photograph (25 times) of the face side ground tissue side is taken perpendicular to the knitted fabric surface to obtain a photograph of 20.2 cm x 28.9 cm. A line is drawn on the photograph at the boundary between the openings that are penetrating without fibers and the non-openings where fibers are present, and all the openings are cut out. When the weight of the openings is A (g) and the weight of the non-openings is B (g), the opening rate is calculated according to the ratio shown in the following formula.
H(%)=[A/(A+B)]×100

The material constituting the ground structure on the other side of the three-dimensional warp knitted fabric, i.e., the ground structure on the opposite side to the face side, is made of polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, etc. Among these, polyethylene terephthalate is preferred because it has excellent dimensional stability even after repeated washing.
These may be used alone or in combination of two or more. When two or more are used in combination, they may be composite yarns or may be combined in an arrangement. Examples of composite yarns include, but are not limited to, ply-twisted yarns, mixed fiber yarns, blended yarns, covering yarns, and aligned yarns.

The total fineness of the yarns used in the face side ground fabric and the other side ground fabric is preferably 167 dtex or less. If it is 167 dtex or less, the texture is soft and it is easier to reduce irritation when it touches the skin. The single yarn fineness of the fiber used in the inner layer 4 is preferably 4.0 dtex or less. If the single yarn fineness is 4.0 dtex or less, the texture is soft and it is easier to reduce irritation when it touches the skin.

Examples of materials for the connecting yarns of the three-dimensional warp knitted fabric include polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate, nylon fibers such as nylon 6 and nylon 66, acrylic fibers mainly composed of polyacrylonitrile, polyolefin fibers such as polyethylene and polypropylene, polyurethane fibers, and synthetic fibers such as polyvinyl chloride fibers; natural fibers such as cotton, hemp, wool, and silk; regenerated fibers such as rayon and cupra; and semi-synthetic fibers such as acetate and triacetate. These may be used alone or in combination of two or more. Among them, cotton, rayon, nylon fibers, and cupra are preferred because they reduce the tingling sensation on the skin, and nylon, which is versatile, is more preferred.
When two or more types are used in combination, they may be combined in a composite yarn or in an arrangement. Examples of composite yarns include, but are not limited to, ply-twisted yarns, mixed fiber yarns, blended yarns, covering yarns, and aligned yarns.

It is preferable that the total fineness of the connecting yarn is 56 dtex or less. If it is 56 dtex or less, the texture will be soft and irritation when it comes into contact with the skin will be reduced.

The inner layer 4 preferably has an air permeability of 250 ^cm3 / ^cm2 ·sec or more. If the air permeability is 250 ^cm3 / ^cm2 ·sec or more, the air permeability is high, and therefore, stuffiness during wearing can be reduced. More preferably, the air permeability is 300 ^cm3 / ^cm2 ·sec or more. In the present invention, the air permeability is measured in accordance with JIS L1096 8.26 Air Permeability Method A (Fragile type method).

The thickness of the inner layer 4 is preferably 1.0 to 5.0 mm. If it is 1.0 mm or more, it is easier to maintain its shape, and if it is 5.0 mm or less, it has excellent breathability.

The inner layer 4 can contain components such as deodorants, antiviral agents, ultraviolet absorbers, infrared absorbers, antistatic agents, antibacterial agents, antifungal agents, insect repellents, flame retardants, and pH adjusters, as necessary. In addition, it is possible to apply processing to impart functionality such as quick drying, hot and cold sensation, and improved texture. Using fibers that have been processed to impart hot and cold sensation as the material for the inner layer 4 is preferable as it further improves the wearing comfort.

The outer layer 5 is a double knit fabric made by plating with elastic and non-elastic yarns, and the double knit fabric is extended to form the ear loops without sewing a separate fabric. This prevents the ears from being hurt by the sewn parts rubbing against each other when worn. Note that elastic yarn is defined as a yarn that has an elongation rate of 100% or more when subjected to a load of 5 cN and a recovery rate of 90% or more after elongation by 100%.

The double knit fabric used for the outer layer 5 is arranged so that the inelastic yarn appears on both surfaces of the double knit fabric and the elastic yarn is present on the inside of the double knit fabric, so it has excellent performance in preventing runs and curling and also has excellent elasticity.

The elastic yarn may be made of, for example, polyurethane fiber.
The elastic yarn may be used alone or in combination of two or more kinds. The thermal deformation starting temperature of the elastic yarn is preferably 150 to 190°C. When the temperature is within this range, the elastic yarns come into contact with each other and are easily deformed when the double knit fabric is subjected to thermal processing such as heat setting, and can be appropriately fixed. In addition, the elastic yarn is not easily embrittled, so that the stretchability and strength are not easily lost. In the present invention, the thermal deformation starting temperature is measured, for example, as follows.

It can be measured using a thermal stress tester (for example, KE-2S, manufactured by the former Kanebo Engineering Co., Ltd.). A jig with hooks is attached to the top and bottom of the tester, and the yarn to be measured is wound 10 times between the top and bottom hooks. With an initial load of 20 cN applied to the wound yarn, the area around the yarn is heated at 2.2°C/sec, and the temperature at which the load on the wound yarn again becomes 20 cN is measured. This measurement is carried out twice, and the average of the two measurements is taken as the thermal deformation onset temperature.

In addition, the total fineness of the fibers used in the elastic yarn is preferably 22 dtex or more. 22 dtex or more is preferable because it has excellent elasticity.

Examples of materials constituting the inelastic yarn include polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate, nylon fibers such as nylon 6 and nylon 66, acrylic fibers mainly composed of polyacrylonitrile, polyolefin fibers such as polyethylene and polypropylene, polyurethane fibers, and synthetic fibers such as polyvinyl chloride fibers; natural fibers such as cotton, hemp, wool, and silk; regenerated fibers such as rayon and cupra; and semi-synthetic fibers such as acetate and triacetate. These may be used alone or in combination of two or more. These may be used alone or in combination of two or more. Among them, nylon fibers, regenerated fibers, and cotton are preferable because they have a soft texture and are less irritating to the skin.
When two or more types are used in combination, they may be combined in a composite yarn or in an arrangement. Examples of composite yarns include, but are not limited to, ply-twisted yarns, mixed fiber yarns, blended yarns, covering yarns, and aligned yarns.

The total fineness of the fibers used in the inelastic yarn is preferably 167 dtex or less. A total fineness of 167 dtex or less is preferable because it allows for a thinner yarn and is less likely to impede the elasticity of the elastic yarn.

The product of warp density and weft density of double knit fabric is preferably 3000 or more. This is because it reduces the tension per loop when stretched in the warp and weft directions, compensates for the small loop restraining force, and improves resistance to runs when stretched. The density (course/25.4 mm, wale/25.4 mm) is measured in accordance with JIS L1096-8.6.2, the method for measuring density of knitted fabrics.

It is preferable that the stretch rate of the double knit fabric in both the warp and weft directions is 180% or more, since it is less likely to cause ear pain even when worn for long periods of time. The stretch rate is measured as follows.

Prepare three warp test pieces with a warp length of 16 cm and a weft length of 2.5 cm, and three weft test pieces with a warp length of 2.5 cm and a weft length of 16 cm. Using a constant-speed extensometer tensile tester (Autograph, Shimadzu Corporation, AG-500D), a chuck jig with a toothed gripping portion for the test piece is used to measure the elongation at a load of 22.1 N at a tension speed of 30 cm/min with an upper grip length of 2.5 cm, a lower grip length of 3.5 cm, grip interval of 10 cm, and a test piece gripping pressure of 490 kPa, and the average value is calculated. The measurement is performed in an environment with a temperature of 20°C and a relative humidity of 65%.

It is preferable that the stretch recovery rate of the double knit fabric in both the warp and weft directions is 92% or more, as this makes it easier to maintain its shape even after repeated wearing. The stretch recovery rate is measured as follows.

Prepare three warp test pieces each with a warp length of 16 cm and a weft length of 2.5 cm, and a weft test piece with a warp length of 2.5 cm and a weft length of 16 cm. Using a constant-speed extension tensile tester (Autograph, Shimadzu Corporation, AG-500D), a chuck jig with a toothed gripping portion for the test piece is used to measure the elongation at a load of 14.7 N at an upper grip length of 2.5 cm, a lower grip length of 3.5 cm, a grip interval of 10 cm, a test piece gripping pressure of 490 kPa, and a tensile speed of 30 cm/min. The elongation is set under the following conditions according to the elongation, and the elongation recovery is repeated three times at a speed of 30±2 cm/min, and an elongation recovery curve is drawn.
(Elongation Condition)
Test elongation of 80% or more: set elongation of 80%
Test elongation is 60% or more and less than 80%: set elongation 60%
Test elongation is 40% or more and less than 60%: set elongation 40%
The residual elongation is read from the elongation recovery curve, and the recovery rate is calculated according to the following formula.
Recovery rate (%) = (L - L0) / L x 100
(Wherein, L: set elongation, L0: residual elongation)

The thickness of the double knit fabric is preferably 0.3 to 3.0 mm. If it is 0.3 mm or more, it is easier to maintain its shape, if it is 3.0 mm or less, it will be soft to the touch and will cause less irritation to the skin, and if it is 0.5 to 2.0 mm, it is even more preferable.

The outer layer 5 can contain components such as deodorants, antiviral agents, ultraviolet absorbers, infrared absorbers, antistatic agents, antibacterial agents, antifungal agents, insect repellents, flame retardants, and pH adjusters, as necessary. In addition, it is possible to apply processing to impart functionality such as quick drying, water repellency, water absorbency, hot and cold sensations, and texture improvement.

The filter layer 6 may be a nonwoven fabric, and examples of the nonwoven fabric include spunbond, meltblown, and needle punch. These may be used alone or in combination of two or more. Among them, meltblown is preferred because of its good filtering performance.
A fiber diameter of 3 μm or less is preferable because of good filtering performance, and a fiber diameter of 1 μm or less is more preferable, whereas a fiber diameter of 0.1 μm or more is preferable because of easy retention of breathability.

Examples of materials constituting the filter layer 6 include polyethylene terephthalate, polypropylene, nylon, and polyethylene. Among these, polypropylene is preferred because it is versatile and inexpensive. These materials may be used alone or in combination of two or more.

The filter layer 6 preferably has an air permeability of 5 ^cm3 / ^cm2 ·sec or more since it is easy to breathe, and more preferably has an air permeability of 10 ^cm3 / ^cm2 ·sec or more. On the other hand, a permeability of ¹⁰⁰ cm3/ ^cm2 ·sec or less is preferable since it is easy to maintain the filter performance, and more preferably has an air permeability of 50 ^cm3 / ^cm2 ·sec or less.

The basis weight of the filter layer 6 is preferably 5 g/ ^m2 or more since excellent filter performance is achieved, and more preferably 10 g/ ^m2 or more. On the other hand, the basis weight is preferably 150 g/ ^m2 or less since breathability is easily maintained, and more preferably 80 g/ ^m2 or less.

It is preferable from the viewpoint of hygiene that the filter layer 6 is subjected to at least one of antibacterial and antiviral treatment. Examples of antibacterial and antiviral treatments include the application of quaternary ammonium salts, ammonium salts, pyridiones, piguanides, zirconium, organic nitrogen, organic bromine, inorganic metal salts, gold, silver, copper, platinum, zinc, gold compounds, silver compounds, copper compounds, platinum compounds, zinc compounds, and zeolite compounds. Methods for applying these include, but are not limited to, gravure, dipping, coating, spraying, plating, sputtering, vapor deposition, or kneading into the base resin during filter manufacturing. In addition, polyurethane resins, acrylic resins, polyester resins, vinyl acetate resins, epoxy resins, PVA resins, vinyl chloride resins, silicone resins, olefin resins, and the like may be used in combination as necessary.

In the central portion 2 of the mask, the inner layer 4, the outer layer 5, and the filter layer 6 are all that is required, and other layers can be added as necessary.

It is preferable to provide an inner layer 4, an outer layer 5, and a storage section 7 for placing the filter layer 6 between them. The storage section 7 can be provided, for example, by sewing parts of the inner layer 4 and the outer layer 5 together to form a pocket or hook shape so that the filter layer 6 does not fall off. FIG. 3 shows an example of a pocket-shaped storage section formed by sewing the upper and lower ends of the inner layer 4 and the outer layer 5 together. By making the filter layer 6 detachable, the filter layer 6 can be removed and washed before washing, so that the mask center section 2 can be kept clean without the performance of the filter layer 6 being reduced by washing.

The shape of the filter layer 6 may be any shape that matches the storage section 7, but any shape can be used, such as a polygonal shape such as an octagon, hexagon, or square, or an approximately circular or elliptical shape.

As long as it does not interfere with the concept of the present invention, the outer peripheral edge of the central part 2 of the mask can be bordered with a stretchable fabric. The border can be formed by sewing, fusing, gluing, etc., but sewing is preferred as it is easy to adjust the stretchability.

The mask of the present invention will be specifically described in the following examples and comparative examples, but the present invention is not limited to these. The physical properties in the examples and comparative examples were measured and evaluated by the following methods.

<Thermal deformation starting temperature>
Measurements were performed using a thermal stress tester (KE-2S, manufactured by the former Kanebo Engineering Co., Ltd.). A jig with hooks was attached to the top and bottom of the tester, and the yarn to be measured was wound 10 times between the top and bottom hooks. With an initial load of 20 cN applied to the wound yarn, the periphery of the yarn was heated at 2.2°C/sec, and the temperature at which the load applied to the wound yarn again became 20 cN was measured. This measurement was performed twice, and the average of the two measurements was taken as the thermal deformation onset temperature.

<Elongation rate>
Three pieces of each of warp direction test pieces with a warp length of 16 cm and a weft length of 2.5 cm were prepared, and weft direction test pieces with a warp length of 2.5 cm and a weft length of 16 cm were prepared. Using a constant speed extensometer tensile tester (Autograph, Shimadzu Corporation, AG-500D), a chuck jig with a toothed shape was used to measure the elongation at a load of 22.1 N at an upper grip length of 2.5 cm, a lower grip length of 3.5 cm, a grip interval of 10 cm, a test piece gripping pressure of 490 kPa, and a tensile speed of 30 cm/min, and the average value was calculated. The environment during the measurement was a temperature of 20°C and a relative humidity of 65%.

<Elongation recovery rate>
Three pieces of each of warp test pieces with a length of 16 cm and a length of 2.5 cm were prepared, and weft test pieces with a length of 2.5 cm and a length of 16 cm were prepared. Using a constant-speed extension tensile tester (Autograph, Shimadzu Corporation, AG-500D), the elongation was measured at a load of 14.7 N at a tensile speed of 30 cm/min, with an upper grip length of 2.5 cm, a lower grip length of 3.5 cm, a grip interval of 10 cm, and a test piece gripping pressure of 490 kPa, and the elongation recovery was repeated three times at a speed of 30±2 cm/min, and an elongation recovery curve was drawn.
(Elongation Condition)
Test elongation of 80% or more: set elongation of 80%
Test elongation is 60% or more and less than 80%: set elongation 60%
Test elongation is 40% or more and less than 60%: set elongation 40%
The residual elongation was read from the elongation recovery curve, and the recovery rate was calculated according to the following formula.
Recovery rate (%) = (L - L0) / L x 100
(Wherein, L: set elongation, L0: residual elongation)

<Breathability>
The air permeability was measured in accordance with JIS L1096, 8.26 Method A (Fragile type method).

<Dimensional stability>
In accordance with JIS L0217 (symbols and methods of labeling for handling textile products) 103, after 50 repeated washings, the length and width of the center of the mask were measured and the length before and after washing was compared.
○: Dimensional change in the vertical and horizontal directions is within ±3%. △: Dimensional change in the vertical and horizontal directions is within ±5%. (Other than ○ evaluation)
×: Dimensional change in the longitudinal and transverse directions exceeds ±5%

<Shape retention>
Ten test subjects were asked to wear the mask for one week and evaluate it according to the following criteria.
5: No contact with the skin when breathing 3: Slight contact with the skin when breathing, slightly stuffy 1: Complete contact with the skin when breathing, very stuffy The masks were rated according to the following criteria from the average rating.
◯: 4 or more and 5 or less △: 2 or more and less than 4 ×: Less than 2

<Ear irritation>
Ten test subjects were asked to wear the mask for one week and evaluate it according to the following criteria.
5: No pain, can be worn for long periods of time 3: Slight pain, but can be worn for long periods of time 1: Very painful, cannot be worn for long periods of time The masks were rated according to the following criteria from the average of the ratings.
◯: 4 or more and 5 or less △: 2 or more and less than 4 ×: Less than 2

<Stuffiness>
Ten test subjects were asked to wear the mask for one week and evaluate it according to the following criteria.
5: No heat buildup when breathing, no stuffiness 3: Some heat buildup when breathing, some stuffiness 1: Significant heat buildup when breathing, stuffiness and discomfort The masks were rated according to the following criteria from the average rating.
◯: 4 or more and 5 or less △: 2 or more and less than 4 ×: Less than 2

[Example 1]
Based on the design shown in Figure 4, a double raschel knitted fabric for the inner layer was knitted using 78 dtex 36f nylon filament yarn for the face side ground fabric and 84 dtex 36f polyethylene terephthalate filament yarn for the other side ground fabric, with a total thickness of 2.6 mm, knitting density of 50 courses/25.4 mm, and 26 wales/25.4 mm. The air permeability of the obtained double raschel knitted fabric was 360 ^cm3 / ^cm2 ·sec, and the opening ratio of the face side ground fabric was 24%.
A double knit fabric for the outer layer was knitted as follows, using a 22 dtex 20f nylon filament yarn as the first knitting yarn, an 80-count cotton yarn as the second knitting yarn, and a 33 dtex polyurethane yarn (ROICA (registered trademark) C-805, manufactured by Asahi Kasei Corporation, heat deformation starting temperature 152 ° C.) as the third knitting yarn. Using a double circular knitting machine (diameter 38 inches, 40 gauge) manufactured by Fukuhara Seiki Seisakusho Co., Ltd., the first knitting yarn, the second knitting yarn, and the third knitting yarn were simultaneously fed from the same feeder to needles on both sides of the dial cylinder, and knitted by plating knitting, and the third polyurethane yarn was arranged on the inside of the knitted fabric to knit a double knit fabric. The obtained double knit fabric had a knitting density of 63 courses / 25.4 mm, 56 wales / 25.4 mm, an elongation rate of 186% in the warp direction and 253% in the weft direction, and an elongation recovery rate of 92% in the warp direction and 93% in the weft direction.
A nonwoven fabric laminated as follows was prepared as a filter layer. A polypropylene nonwoven fabric with a basis weight of 20 g/ ^m2 produced by the spunbond method was used for the upper and lower layers, and a polypropylene nonwoven fabric with a basis weight of 10 g/ ^m2 produced by the melt-blowing method was used for the middle layer. The three layers were laminated and pressed with a hot embossing roll. The obtained laminated nonwoven fabric had a basis weight of 50 g/ ^m2 and an air permeability of 26 ^cm3 / ^cm2 ·sec. An organic nitrogen bromine compound was applied to the laminated nonwoven fabric by the gravure method to impart antiviral properties, and the laminated nonwoven fabric was cut into the shape shown in FIG. 1 to obtain a filter layer. The obtained double raschel knit fabric for the inner layer and the double knit fabric for the outer layer were cut and sewn to obtain the shape shown in FIG. 1 and FIG. 3. The double knit fabric for the outer layer was designed to form an ear loop portion extended from the center of the mask. A filter layer was inserted between the inner layer and the outer layer as shown in FIG. 3 to obtain a mask. The masks thus obtained were evaluated according to the above-mentioned evaluation methods. The physical properties and evaluation results are shown in Table 1.

[Example 2]
Based on the design shown in Figure 5, a 117 dtex 80f nylon and cupra blend yarn was used for the face side ground fabric, and a 84 dtex 36f polyethylene terephthalate filament yarn was used for the other side ground fabric, to knit a double raschel knit fabric for the inner layer with a total thickness of 1.5 mm, a knitting density of 46 courses/25.4 mm, and 26 wales/25.4 mm.
Except for not using the cotton yarn of the second knitting yarn, a double knit fabric for the outer layer was knitted in the same manner as in Example 1. The obtained double knit fabric had a knitting density of 95 courses/25.4 mm and 49 wales/25.4 mm, an elongation rate of 196% in the warp direction and 241% in the weft direction, and an elongation recovery rate of 93% in the warp direction and 92% in the weft direction.
Except for using the obtained double raschel knit fabric and double knit fabric, a mask was obtained in the same manner as in Example 1. The obtained mask was evaluated according to the above-mentioned evaluation method. The physical property values and evaluation results are shown in Table 1.

[Comparative Example 1]
Based on the design shown in FIG. 6, a 78 dtex 36f nylon filament yarn was used for the face side ground fabric, and a 78 dtex 36f nylon filament yarn was used for the other side ground fabric, and a double raschel knitted fabric for the inner layer was knitted with a total thickness of 1.5 mm, a knitting density of 49 courses/25.4 mm, and 26 wales/25.4 mm.
Except for using the obtained double raschel knitted fabric, a mask was obtained in the same manner as in Example 1. The obtained mask was evaluated according to the above-mentioned evaluation methods. The physical property values and evaluation results are shown in Table 1.

[Comparative Example 2]
Based on the design shown in FIG. 7, a 78 dtex 36f nylon filament yarn was used for the face side ground fabric, and a 84 dtex 36f polyethylene terephthalate filament yarn was used for the other side ground fabric, and a double raschel knitted fabric for the inner layer was knitted with a total thickness of 2.7 mm, a knitting density of 44 courses/25.4 mm, and 30 wales/25.4 mm.
A double knit fabric for the outer layer was knitted in the same manner as in Example 1, except that a 78 dtex 36f nylon filament yarn was used as the first knitting yarn, a 22 dtex polyurethane yarn (Lycra (registered trademark) T-127C, manufactured by Opelontex Co., Ltd., heat deformation starting temperature 165°C) was used as the third knitting yarn, and no cotton yarn was used as the second knitting yarn. The obtained double knit fabric had a knitting density of 80 courses/25.4 mm and 60 wales/25.4 mm, an elongation rate of 110% in the warp direction and 150% in the weft direction, and an elongation recovery rate of 85% in the warp direction and 83% in the weft direction.
Except for using the obtained double raschel knit fabric and double knit fabric, a mask was obtained in the same manner as in Example 1. The obtained mask was evaluated according to the above-mentioned evaluation method. The physical property values and evaluation results are shown in Table 1.

As shown in Table 1, the mask of the embodiment was good in all performance aspects. In contrast, the mask of the comparative example was poor in some performance aspects.

1 Mask 2 Central mask portion 3 Ear loop portion 4 Inner layer 5 Outer layer 6 Filter layer 7 Storage portion

Claims (3)

A mask comprising an inner layer on a face side, an outer layer on a side opposite to the face, and a filter layer disposed between the inner layer and the outer layer,
The inner layer is
It is a three-dimensional warp knitted fabric,
The base fabric on the face side mainly contains a fiber selected from the group consisting of nylon fibers, cotton, rayon, and cupra,
The fabric on the opposite side of the face is mainly made of polyester fibers.
At least the face side is mesh-like,
The outer layer is
This is a double knit fabric made by plating with elastic yarn and non-elastic yarn.
The double knit fabric is extended to form ear loops without sewing,
The filter layer is
The mask is made of nonwoven fabric and is removable. The mask of claim 1, wherein the double knit fabric has a stretch rate of 180% or more and a stretch recovery rate of 92% or more. The mask according to claim 1 or 2, wherein the double knit fabric is made of inelastic yarn and elastic yarn whose thermal deformation onset temperature is 150 to 190°C.