JP2012020006A - Mask and filter used for the mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a mask which is superior in antimicrobial property at low cost.SOLUTION: The mask 1 includes a filter base material for breathing air flow, a filter 21 held by the filter base material comprising a compound with a mayenite structure, and a fixing tool 3 for fixing the filter 21 on a user.

Description

  The present invention relates to a mask including a filter that transmits inspiration and expiration.

  It is desired that a mask used for the purpose of suppressing airborne infection such as droplet infection has a high ability to block bacteria. Patent Document 1 describes that particles made of a calcium phosphate compound are supported on a filter base material of a mask and bacteria are adsorbed on these particles.

  In addition, it is desirable that the mask used for the above-described purpose has a high ability to prevent the growth of bacteria. For example, when silver or silver oxide is supported on the filter substrate, a mask having excellent antibacterial properties can be obtained.

JP-A-5-115582

However, silver is expensive, and it is generally desirable to use a cheaper antimicrobial agent in an inexpensive mask.
Therefore, an object of the present invention is to make it possible to realize a mask that is inexpensive and has excellent antibacterial properties.

  According to the 1st side surface of this invention, the filter for masks provided with the filter base material which permeate | transmits exhalation, and the compound carry | supported by the said filter base material and which has a mayenite structure is provided.

  According to the 2nd side surface of this invention, the mask provided with the filter which concerns on a 1st side surface, and the fixing tool which fixes the said filter with respect to a wearer is provided.

  According to the present invention, it is possible to realize a mask that is inexpensive and has excellent antibacterial properties.

The top view which shows schematically the mask which concerns on 1 aspect of this invention. Sectional drawing along the II-II line of the mask shown in FIG. The figure which shows a mode that the mask shown in FIG.1 and FIG.2 is worn. Sectional drawing which shows roughly an example of the filter which can be used in the mask shown in FIG.1 and FIG.2. Sectional drawing which shows schematically the other example of the filter which can be used in the mask shown in FIG.1 and FIG.2. The figure which shows the molecular structure of the calcium aluminate which has a mayenite structure. The perspective view which shows roughly the modification of the mask shown in FIG.1 and FIG.2. The graph which shows an example of the relationship between the wearing time of a mask, and its mass increment. The graph which shows an example of the relationship between the leaving time of an antibacterial agent in the atmosphere similar to human expiration, and its mass increment. The graph which shows an example of the influence which the quantity of the calcium aluminate which has a mayenite structure has on the antibacterial property of a filter. The graph which shows an example of the antibacterial property of the calcium aluminate which has a mayenite structure, and another antibacterial agent. The graph which shows an example of the influence which another antibacterial agent has on the antibacterial property of the calcium aluminate which has a mayenite structure. The graph which shows the other example of the influence which another antibacterial agent has on the antibacterial property of the calcium aluminate which has a mayenite structure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same referential mark is attached | subjected to the component which exhibits the same or similar function through all the drawings, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a plan view schematically showing a mask according to one aspect of the present invention. 2 is a cross-sectional view taken along the line II-II of the mask shown in FIG. FIG. 3 is a diagram schematically showing a state in which the mask shown in FIGS. 1 and 2 is worn. In the following description, the terms “upper”, “lower”, “left” and “right” used with respect to the mask 1 and its components are used regardless of whether or not the mask 1 is worn. As shown in FIG. 3, it means the direction when the wearer W wearing the mask 1 is standing upright.

  A mask 1 shown in FIGS. 1 to 3 is a mask used for the purpose of suppressing air infection such as droplet infection. As shown in FIGS. 1 and 3, the mask 1 includes a mask body 2 and a fixture 3.

  The mask body 2 includes a filter 21, a pair of holding members 22, and a shaping member 23.

  The filter 21 has air permeability. As shown in FIGS. 1 to 3, the filter 21 is provided with a plurality of folds substantially parallel to each other.

  Specifically, the upper end portion and the lower end portion of the filter 21 are folded back as shown in FIG. 2 to form folded portions P1 and P3, respectively. In the folded portions P1 and P3, the mutually facing portions of the filter 21 are joined to maintain the shape thereof. At least one of the upper end portion and the lower end portion of the filter 21 may not be folded.

Moreover, the part P2 located between the folding | returning parts P1 and P3 among the filters 21 is folded in the shape of a pleat. This portion P2 may not be folded.
The material and detailed structure of the filter 21 will be described later.

  The holding member 22 has a band shape as shown in FIGS. 1 and 3. These holding members 22 are arranged so as to sandwich the left and right ends of the folded filter 21, and are joined to the filter 21 there. The holding member 22 restricts the extension of the left and right end portions of the filter 21 in the vertical direction without restricting the expansion and contraction of the center portion of the filter 21 in the vertical direction. The holding member 22 is made of cloth such as woven fabric and non-woven fabric, paper, or film, for example.

  The shaping member 23 is typically made of a wire coated with a resin or a thin metal plate in a band shape. The shaping member 23 is installed in the vicinity of the upper end of the filter 21 so that the length direction thereof is substantially parallel to the crease provided in the filter 21. As shown in FIG. 2, the shaping member 23 is sandwiched by the filter 21 at the folded portion P1. As shown in FIG. 3, the shaping member 23 is deformed into a shape along the face of the wearer W when the mask 1 is worn, thereby minimizing the gap between the filter 2 and the face of the wearer W.

  The fixture 3 is attached to the mask body 2 as shown in FIGS. 1 and 3. Here, the fixture 3 is a pair of rubber strings. One of these rubber straps has two ends joined to two corners located on the left side of the mask main body 2, and forms a ring structure together with the mask main body 2. The other ends of these rubber straps are joined to two corners located on the right side of the mask main body 2, respectively, and form a ring structure together with the mask main body 2. The mask body 2 is fixed to the wearer W by putting these rubber strings on the left and right ears of the wearer W.

Next, the structure of the filter 21 and the material used therefor will be described.
FIG. 4 is a cross-sectional view schematically showing an example of a filter that can be used in the mask shown in FIGS. 1 and 2.

  The filter 21 includes a layered filter material 21a. The filter 21 may have a single layer structure made of the filter material 21a. Alternatively, the filter 21 may have a multilayer structure including the filter material 21a. In the latter case, the filter material 21a and another layer may be laminated, or the filter material 21a may be overlaid.

  The filter material 21a includes a filter base material 21a1 and an antibacterial agent 21a2.

  Filter base material 21a1 is a nonwoven fabric, for example. In the filter 21 shown in FIG. 4, the filter base material 21a1 has a two-layer structure. A woven fabric, paper, or a porous film may be used as the filter substrate 21a1.

  The antibacterial agent 21a2 is carried by two layers constituting the filter base material 21a1. Here, the antibacterial agent 21a2 is distributed between the layers of the filter base material 21a1. In such a structure, for example, the antibacterial agent 21a2 is dispersed on one layer constituting the filter base material 21a1, and the other layer constituting the filter base material 21a1 is provided thereon, and these layers are integrated. Can be obtained. When the antibacterial agent 21a2 is disposed between the layers of the filter base material 21a1, the antibacterial agent 21a2 can be prevented from falling off.

  FIG. 5 is a cross-sectional view schematically showing another example of a filter that can be used in the mask shown in FIGS. 1 and 2.

  In the filter 21, the antibacterial agent 21a2 is distributed over the entire filter base 21a1. When this structure is adopted, the antibacterial agent 21a2 may drop off from the filter base material 21a1. Therefore, in this filter 21, in addition to the layered filter material 21a, a pair of surface layer materials 21b are further provided.

  The filter base material 21a1 of the filter 21 is obtained by the following method, for example. First, as the filter substrate 21a1, a nonwoven fabric or a woven fabric made of core-sheath fibers is prepared. Next, the antibacterial agent 21a2 is fed into the filter base 21a1 using hot air. Thereby, without softening the resin which comprises the core part, the thermoplastic resin which comprises the sheath part is softened, and the antibacterial agent 21a2 is made to adhere there. If the particle size of the antibacterial agent 21a2 is sufficiently smaller than the gap between the fibers, the antibacterial agent 21a2 can be distributed throughout the filter base 21a1.

  The surface layer material 21b is joined to the front surface and the back surface of the filter material 21a, respectively. The surface layer material 21b is a nonwoven fabric, for example.

  For joining the surface layer material 21b to the filter material 21a, for example, heat fusion can be used. The surface layer material 21b may be bonded to the filter material 21a using an adhesive, or may be bonded to the filter material 21a using a needle punch.

  As the surface layer material 21b, a woven fabric, paper, or a porous film may be used. Further, the surface layer material 21b or both may be omitted.

  The filter 21 shown in FIGS. 4 and 5 uses a compound having a mayenite structure, for example, a calcium aluminate having a mayenite structure, as at least a part of the antibacterial agent 21a2. This compound will be described with reference to FIG.

  FIG. 6 is a diagram showing the molecular structure of calcium aluminate having a mayenite structure.

Calcium aluminate having a mayenite structure is a compound represented by the chemical formula 12CaO · 7Al ₂ O ₃ . Hereinafter, this compound is abbreviated as “C12A7”.

The constituent atoms of C12A7 form a plurality of cage structures that are three-dimensionally connected as shown in FIG. These cages have an internal space with a diameter of about 0.4 nm and can include active oxygen species such as O ⁻ , O ²⁻ and O ₂ ⁻ . These active oxygen species, unlike the oxygen atoms constituting the C12A7 skeleton, exhibit high oxidizing power. C12A7 is much cheaper than antibacterial agents such as silver and silver compounds. Therefore, if the above oxidizing power can be used for sterilization, there is a possibility that a low-cost and antibacterial mask can be realized.

C12A7 does not develop high oxidizing power in the absence of moisture and therefore does not show high bactericidal power. However, C12A7 exhibits extremely high sterilizing power by supplying a sufficient amount of moisture. Although the reason why moisture affects the sterilizing power is not necessarily clarified, the present inventors have generated OH ⁻ ions by the reaction between oxygen active species and water, and these OH ⁻ ions This is because it contributes to sterilization.

  When the mask 1 is worn, moisture in the atmosphere can be supplied to the C12A7 as the wearer W inhales, and moisture is supplied to the C12A7 from the exhalation of the wearer W. In general, exhaled air contains moisture at a higher concentration compared to inspiration. In addition, the external environment such as atmospheric humidity does not have a significant effect on the moisture concentration of the breath. Therefore, the mask 1 exhibits excellent antibacterial properties in almost a certain time after wearing, regardless of the external environment.

  In this mask 1, C12A7 may be distributed over the entire filter base 21a1. Alternatively, C12A7 may be distributed only in a region of the filter base material 21a1 where inspiration and expiration pass. Alternatively, C12A7 may be distributed at a high density in a region of the filter base 21a1 where inspiration and expiration pass, and may be distributed at a lower density in other regions.

In the region of the filter 21 through which exhalation passes, the amount of C12A7 with respect to this area is, for example, 10 g / m ² or more, typically 27 g / m ² or more. The amount of C12A7 with respect to the previous area is, for example, 60 g / m ² or less, and typically 30 g / m ² or less. When the amount of C12A7 is small, it is difficult to develop high antibacterial properties. When the amount of C12A7 is large relative to the amount of water supplied by exhalation, even if the amount of C12A7 is increased, the antibacterial properties are not greatly improved.

  As C12A7, for example, one having an average particle diameter measured by a laser diffraction scattering method in a range of 0.5 μm to 50 μm is used. When C12A7 having a small average particle size is used, the contact probability between C12A7 and bacteria increases. However, C12A7 having an extremely small average particle diameter is difficult to handle and difficult to carry on the filter base 21a1.

  The calcium atom of C12A7 may be at least partially substituted with a strontium atom. That is, the antibacterial agent 21a2 may contain calcium aluminate having a mayenite structure, may contain strontium aluminate having a mayenite structure, or may contain both of them. .

  Moreover, a part of calcium atom and / or strontium atom may be substituted with at least one of magnesium atom and barium atom.

  The aluminum atom of C12A7 may be partially substituted with at least one of a silicon atom, a germanium atom, and a gallium atom.

  As the antibacterial agent 21a2, a compound having a mayenite structure and another antibacterial agent may be used in combination. A compound having a mayenite structure may exhibit antibacterial properties even in the absence of moisture, but does not exhibit high antibacterial properties until a sufficient amount of moisture is supplied. Using other antibacterial agents that do not have a significant effect on the performance of the antibacterial agent achieves an excellent antibacterial effect even during the period until the compound having the mayenite structure exhibits high antibacterial properties can do.

  As such an antibacterial agent, for example, silver, a silver compound, titanium oxide, magnesium oxide, dolomite, zeolite, or a mixture containing two or more thereof can be used. In particular, when a compound having a mayenite structure is used in combination with at least one of silver, a silver compound, magnesium oxide, and dolomite, antibacterial performance in a period in which the compound having a mayenite structure exhibits high antibacterial properties is also improved. . When magnesium oxide is used, the mass ratio with respect to C12A7 is preferably about 1 or less, and more preferably in the range of 0.5 to 1.

  As described above, the antibacterial agent used in combination with the compound having a mayenite structure plays an auxiliary role with respect to antibacterial properties. Therefore, the mass ratio of the additional antibacterial agent to the compound having the mayenite structure is set, for example, within a range of 10% to 100%.

The mask 1 can be variously modified.
FIG. 7 is a perspective view schematically showing a modification of the mask shown in FIGS. 1 and 2.

  In the mask 1 shown in FIG. 7, the mask body 2 includes a face piece 2a and a filter unit 2b.

  The face piece 2a is a molded product formed so as to cover the nose and mouth of the wearer W and the periphery thereof when the mask 1 is worn. Typically, the face piece 2a is made of a flexible material such as rubber so that the mask 1 is deformed when the mask 1 is worn and the entire edge thereof is in close contact with the face of the wearer W.

  The face body 2a is provided with one or more through holes through which inhalation and exhalation of the wearer W passes. The filter unit 2b is attached to the face piece 2a at the position of the through hole.

  The filter unit 2b includes a mount (not shown), a holder 2b1, and a filter 21.

  The mount has, for example, a cylindrical shape. Alternatively, the mount has a plate shape provided with a through hole. The mount is attached to the face piece 2a at a position of a through hole provided in the face piece 2a.

  The holder 2b1 is detachably attached to the mount. For example, the holder 2b1 is engaged with or screwed with the mount.

  The holder 2b1 is provided with a flow path through which inspiration and expiration flow. The holder 2b1 detachably supports the filter 21 in the flow path.

  Further, in the mask 1, the fixture 3 is a belt made of rubber, for example. One end of this belt is attached to the right end of the face piece 2a, and the other end is attached to the left end of the face piece 2a. The mask body 2 is fixed to the wearer W by pressing the face 2a against a predetermined position of the face of the wearer W and turning the belt around the back of the head of the wearer W.

  In the mask 1, as described above, the filter 21 is detachable. Therefore, the mask 1 can be used repeatedly by replacing the used filter 21 with an unused filter 21.

  The technique described above is typically applied to a sanitary mask, but may be applied to a mask other than a sanitary mask. For example, the above-described technique can be applied to a dust mask or a gas mask.

  Examples of the present invention will be described below.

<Manufacture of antibacterial agent A1>
The calcium carbonate powder and the alumina powder were sufficiently mixed so that the molar ratio of calcium carbonate and alumina was 12: 7. This mixture was baked at 1350 ° C. for 6 hours in an oxygen atmosphere. Next, the fired product was pulverized using a ball mill to obtain a powder having an average particle size of about 10 μm. When this powder was subjected to X-ray diffraction analysis, it was confirmed that it was a calcium aluminate having a mayenite structure represented by the chemical formula 12CaO · 7Al ₂ O ₃ . Hereinafter, this calcium aluminate is referred to as “antibacterial agent A1”.

<Creation of filter FA1>
A non-woven fabric having a fiber core portion and a sheath portion made of polypropylene and polyethylene, respectively, was cut to prepare two non-woven fabric pieces having an area of 50 cm ² . Next, 0.15 g of the antibacterial agent A1 was uniformly sprayed on one piece of nonwoven fabric. Subsequently, the other nonwoven fabric piece was piled up on this nonwoven fabric piece, and heat and pressure were applied to this laminated body using the iron. Thereby, the nonwoven fabric pieces were heat-sealed. A filter was obtained as described above. Hereinafter, this filter is referred to as “filter FA1”.

<Filter antibacterial test 1>
A bacterial solution containing about 10 ⁵ E. coli (NBRC3982) per mL was prepared, and 0.1 mL of the solution was sprayed on the filter FA1. After standing at room temperature for 5 minutes, E. coli adhering to the filter FA1 was washed away with 10 mL of buffer solution. Here, a buffer solution having a pH value of 4 was used. Subsequently, the E. coli washed away with the buffer was smeared on the SCD agar medium. And it culture | cultivated over 24 hours at 30 degreeC, and calculated | required the number of colon_bacillus | E._coli from the number of the formed colonies.

Moreover, the filter was created by the method similar to filter FA1 except having omitted antibacterial agent A1. Hereinafter, this filter is referred to as “filter FB1”. An antibacterial test similar to that described above was performed except that this filter FB1 was used instead of the filter FA1.
These results are summarized in Table 1 below.

  In Table 1, “E. coli survival rate” is a relative value of the number of E. coli based on the results obtained when filter FB1 was used.

  As shown in Table 1, the filter FA1 containing C12A7 showed far superior antibacterial properties compared to the filter FB1.

<Antimicrobial test of commercially available antimicrobial mask filters>
An antibacterial test similar to that described above for the filter FA1 was conducted except that commercially available filters FB2 to FB6 each containing the antibacterial agent shown in Table 2 below were used instead of the antibacterial agent A1.
These results are summarized in Table 2 below.

  As is clear from the comparison of the data shown in Table 1 and Table 2, the filter FA1 containing C12A7 showed excellent antibacterial properties as compared with commercially available filters.

<Effect 1 of amount of C12A7 on antibacterial properties of filter>
A filter was prepared by the same method as described above for the filter FA1, except that the amount of the antibacterial agent A1 applied was 0.05 g. Hereinafter, this filter is referred to as “filter FA2”. An antibacterial test similar to that described above for filter FA1 was performed except that this filter FA2 was used instead of filter FA1.

Further, a filter was prepared by the same method as described above for the filter FA1 except that the amount of the antibacterial agent A1 applied was 0.3 g. Hereinafter, this filter is referred to as “filter FA3”. An antibacterial test similar to that described above for filter FA1 was performed except that filter FA3 was used instead of filter FA1.
These results are summarized in Table 3 below.

As shown in Table 3, when the amount of C12A7 supported was within the range of 10 g / m ^{2 to} 60 g / m ² , excellent antibacterial properties could be achieved.

<Effect of active oxygen amount on antibacterial properties of filter>
A powder having an average particle diameter of about 10 μm was obtained by the same method as described above for the antibacterial agent A1, except that the baking was performed in an air atmosphere instead of in an oxygen atmosphere. When this powder was subjected to X-ray diffraction analysis, it was confirmed that it was a calcium aluminate having a mayenite structure represented by the chemical formula 12CaO · 7Al ₂ O ₃ . Hereinafter, this calcium aluminate is referred to as “antibacterial agent A2”.

Next, the amount of active oxygen was measured for each of the antibacterial agents A1 and A2. Specifically, for each of the antimicrobial agents A1 and A2, and subject to electron spin resonance spectroscopy as 77K, O ₂ from the spectrum ^- concentrations were determined ion radical ^- ion radical and O.

Next, a filter was prepared by the same method as described above for the filter FA1 except that the antibacterial agent A2 was used instead of the antibacterial agent A1. Hereinafter, this filter is referred to as “filter FA4”. An antibacterial test similar to that described above was performed except that this filter FA4 was used instead of the filter FA1.
These results are summarized in Table 4 below.

In Table 4, the column of "antimicrobial agent", the amount of active oxygen of C12A7 used, i.e., O ₂ of antimicrobial agents A1 and A2 ^- ion radical concentration, or O ^- have parentheses ion radical concentration.
As shown in Table 4, when the antibacterial agent A1 having a larger amount of active oxygen was used, particularly excellent antibacterial properties could be achieved. Even when the antibacterial agent A2 having a smaller amount of active oxygen was used, sufficient antibacterial properties could be achieved.

<Filter antibacterial test 2>
A bacterial solution containing about 10 ⁵ S. aureus (NBRC13276) per mL was prepared, and 0.1 mL thereof was sprayed on the filter FA1. After standing at room temperature for 5 minutes, E. coli adhering to the filter FA1 was washed away with 10 mL of buffer solution. Here, a buffer solution having a pH value of 4 was used. Subsequently, the E. coli washed away with the buffer was smeared on the SCD agar medium. And it culture | cultivated over 24 hours at 30 degreeC, and calculated | required the number of Staphylococcus aureus from the number of the formed colonies.

Further, an antibacterial test similar to that described above was performed except that the filter FB1 was used instead of the filter FA1.
These results are summarized in Table 5 below.

  In Table 5, “S. aureus survival rate” is the relative value of the number of Staphylococcus aureus based on the results obtained when filter FB1 was used.

  As shown in Table 5, the filter FA1 containing C12A7 showed far superior antibacterial properties compared to the filter FB1.

<Effect of moisture on antibacterial properties>
Thoroughly dried antimicrobial agent A1, was contacted about 10 ⁴ E. coli that 0.5 g. After standing at room temperature for 5 minutes, it was suspended in buffer. Here, a buffer solution having a pH value of 4 was used. Next, the antibacterial agent was allowed to settle, and a part of the supernatant of this liquid was applied to the SCD agar medium. Subsequently, culture was performed at 30 ° C. for 24 hours, and the number of E. coli was determined from the number of colonies formed.

Further, the same test was performed except that the antibacterial agent A1 was hydrated before being brought into contact with Escherichia coli. Here, the water content of the antibacterial agent A1 was 0.2, 1.0, 5.0, and 10.0% by mass with respect to the antibacterial agent A1.
These results are summarized in Table 6 below.

  In Table 6, “ND” represents that E. coli could not be detected, that is, the number of E. coli was 200 or less.

  As shown in Table 6, C12A7 showed far superior antibacterial properties in the presence of moisture compared to the absence of moisture. Specifically, even when the water content of C12A7 was as low as 0.2% by mass, the antibacterial properties of C12A7 were improved as compared with the case where the water content was 0% by mass. And C12A7 which made the water content of C12A7 1.0 mass% or more showed the very outstanding antimicrobial property.

<Change in the mass of the mask when worn>
A plurality of subjects were allowed to wear a commercially available mask whose filter was a nonwoven fabric, and the change in mass of the mask over time was examined. The result is shown in FIG.

FIG. 8 is a graph showing an example of the relationship between the wearing time of the mask and its mass increment.
In FIG. 8, the horizontal axis represents the wearing time of the mask. The vertical axis indicates the difference between the mask mass M1 (t) at the time when the time t has elapsed from the start of wearing and the mask mass M1 (0) at the initial stage M1 (t) -M1 (0) and the mass M1 (0 ) And [M1 (t) −M1 (0)] / M1 (0). The data shown in FIG. 8 is an average of the results obtained for a plurality of subjects.

  As shown in FIG. 8, the mask mass increased with the passage of time when the elapsed time from wearing was within a range of 7 hours. The change in the mass of the mask at the time of wearing is mainly due to the change in the moisture content of the mask. In a certain environment, the moisture is supplied to the mask mainly by the wearer's breath. From the above, it can be seen that the moisture content of the mask increases with the passage of time because the breath of the wearer supplies moisture to the mask within a time period of 7 hours since wearing.

  Moreover, as shown in FIG. 8, the mass of the mask increased by about 0.2% when about 30 minutes passed from wearing, and increased by about 1% when about 3 hours passed after wearing. Assuming that moisture from exhaled air is evenly distributed to the components of the mask, when a mask including a filter having C12A7 supported on a filter substrate is worn, the water content of C12A7 is about 30 from wearing. It is estimated that it reaches about 0.2% when minutes pass and reaches about 1% when about 3 hours have passed since wearing. From the above, a mask including a filter in which C12A7 is carried on a filter base material exhibits excellent antibacterial properties in a relatively short time after wearing, and in addition, a few hours have passed since wearing, It can be seen that when it is in a highly moist and easy to grow state, it exhibits extremely excellent antibacterial properties.

<Mass change of C12A7 due to moisture absorption>
Human exhaled breath is a hot and humid gas having a temperature of about 36 ° C. and a relative humidity of about 95% or more. This high temperature and high humidity condition was reproduced in a thermostatic chamber, and the weight increase due to moisture absorption of C12A7 was measured.

  Specifically, 30 g of the antibacterial agent A1 was left in a thermostatic chamber in which the atmosphere was set to a temperature of 36 ± 1 ° C. and a relative humidity of 85% or more. The mass of the antibacterial agent was measured after 1, 2, 3 and 5 hours from the start of standing in the thermostat, and the mass increase rate was calculated. This was repeated three times, and the average value of the mass increase rates was determined for each elapsed time. The result is shown in FIG.

FIG. 9 is a graph showing an example of the relationship between the standing time of the antibacterial agent and its mass increment in an atmosphere similar to human breath.
In FIG. 9, the horizontal axis represents the standing time of C12A7 in the thermostat. Further, the vertical axis represents the difference between the mass M2 (t) of C12A7 at the time when the time t has elapsed since the start of standing and the mass M2 (0) of C12A7 in the initial stage, and the mass M2 (t) −M2 (0). The ratio [M2 (t) −M2 (0)] / M2 (0) with M2 (0) is represented.

  Usually, human exhalation is much more humid than inspiration. Therefore, when C12A7 is used in a mask filter, the mass increase due to moisture absorption of C12A7 is mainly caused by exhalation. That is, when the filter wears a mask containing C12A7, the mass increase of C12A7 during the period of inhaling is small compared with the mass increase of C12A7 during the period of exhaling.

  Assuming that the proportion of breathing during the exhaling period is about 50% and the mass of C12A7 does not change during the inhaling period, the mass of C12A7 increases when the filter wears a mask containing C12A7. The rate is considered to be about half of the value shown in FIG. Considering this, when comparing the data shown in FIG. 9 with the data shown in FIG. 8, the mass increase rate of C12A7 when the mask is worn is within the period up to about 2 hours when the mask is worn. It can be seen that it is equal to or higher than the mass increase rate.

<Verification of inhibitory effect on droplet infection>
10 μL of a bacterial solution containing E. coli and water was added to 100 mg of agar, and this was mixed for 1 minute. Thereby, E. coli-added agar containing about 1 × 10 ⁵ E. coli and 9% by mass of water was obtained. Moreover, the E. coli addition agar which made water content 17 mass%, 33 mass%, 50 mass%, and 67 mass% by the same method was prepared.

  Next, 1000 mg of the antibacterial agent A1 was added to each of these E. coli-added agars. After mixing these for 1 minute, 10 mL of 50 mM citrate buffer was added to each mixture, and reaction was stopped. Next, 100 μL of each supernatant was smeared on a plate medium and cultured at 37 ° C. for 24 hours. And the number of colon_bacillus | E._coli was calculated | required from the number of formed colonies.

For comparison, E. coli-added agar with a water content of 9% by mass, 17% by mass, 33% by mass, 50% by mass and 67% by mass was prepared by the same method as above, and antibacterial agent A1 was added. A similar test was conducted except that it was not. Based on the number of E. coli obtained as a result of these comparative tests, the survival rate of E. coli was calculated.
These results are summarized in Table 7 below.

  In Table 7, “E. coli survival rate” is a relative value of the number of E. coli based on the results obtained in the comparative test.

  As shown in Table 7, when the water content of the E. coli-added agar was 67% by mass, extremely excellent bactericidal performance could be achieved. In addition, as shown in Table 7, excellent sterilization performance can be achieved even when the water content of E. coli-added agar is 50% by mass or less, and when the water content of E. coli-added agar is 33% by mass or more, Excellent sterilization performance was achieved as compared with the case where the water content of the added agar was 17% by mass or less. As can be seen, if a mask having C12A7 supported on a filter base material is worn, infection can be suppressed even if splashes containing bacteria are dried on the filter of the mask.

<Creation of filters FA5 to FA8 and FB7>
Antibacterial agent A1 was uniformly sprayed on the same non-woven fabric used in the manufacture of filter FA1. Here, the antibacterial agent A1 was sprayed so that the amount per unit area of the nonwoven fabric was 0.41 mg / cm ² . Next, a filter was obtained by performing heat treatment at 100 ° C. to 150 ° C. to adhere the antibacterial agent A1 to the nonwoven fabric. Hereinafter, this filter is referred to as “filter FA5”.

The filter FA5 is described above except that the antibacterial agent A1 is sprayed so that the amount per unit area of the nonwoven fabric is 0.80 mg / cm ² , 1.60 mg / cm ² , and 2.72 mg / cm ^2. A filter was created in the same manner. Hereinafter, a filter in which the application rate of the antimicrobial agent A1 and 0.80 mg / cm ² is referred to as a "filter FA6", referred to filter the application rate of the antimicrobial agent A1 and 1.60 mg / cm ² as "filter FA7" A filter in which the application amount of the antibacterial agent A1 is 2.72 mg / cm ² is referred to as “filter FA8”.

  Further, a filter was prepared by the same method as described above for the filter FA5 except that the antibacterial agent A1 was omitted. Hereinafter, this filter is referred to as “filter FB7”.

<Effect 2 of amount of C12A7 on antibacterial properties of filter>
Filter FA5 was fragmented to dimensions of about 5 mm × 5 mm. These fragmented filters FA5 were weighed out so that the nonwoven fabric had a mass of 3 g, and the direct line was spread on a 14.2 cm disk. Then, a bacterial solution containing E. coli (NBRC3972) was prepared, and 25 μL of the bacterial solution was sprayed on the filter FA5 fragment. After standing at room temperature for 2 minutes, E. coli adhering to the fragment of the filter FA5 was washed away with 50 mL of buffer solution. Here, 50 mM citrate buffer was used. Subsequently, the E. coli washed away with the buffer was smeared on the SCD agar medium. And it culture | cultivated over 24 hours at 30 degreeC, and calculated | required the number of colon_bacillus | E._coli from the number of the formed colonies.

  Next, an antibacterial test similar to that described above was performed except that the spray amount of the bacterial solution was 30 μL and 35 μL. And the number of colon_bacillus | E._coli obtained when the amount of spray of a microbe liquid was 25 microliters, 30 microliters, and 35 microliters was arithmetically averaged, and the survival rate of colon_bacillus | E._coli was computed using this. Note that setting the spray amount to 25 μL to 35 μL corresponds to supplying 0.83% by mass to 1.17% by mass of water together with E. coli with respect to the nonwoven fabric.

  Further, the same antibacterial test as described above was performed except that filters FA6 to FA8 and FB7 were used instead of the filter FA5. For each of the filters FA6 to FA8 and FB7, the number of E. coli obtained when the spray amount of the bacterial solution was 25 μL, 30 μL and 35 μL was arithmetically averaged, and the survival rate of E. coli was calculated using this. .

Table 8 below summarizes the amount of bacterial solution used and the number of E. coli contained in the bacterial solution. The test results obtained for each of the filters FA5 to FA8 and FB7 are summarized in Table 9 below and FIG.

  In Table 9, “E. coli survival rate” is the ratio between the number of E. coli obtained by the above arithmetic mean and the number of E. coli contained in 30 μL of the bacterial solution.

As shown in Table 9 and FIG. 10, when C12A7 was supported on the filter base material, the survival rate of Escherichia coli could be lowered as compared with the case where C12A7 was not supported on the filter base material. In particular, when the loading amount of C12A7 was about 2.7 mg / cm ² , the survival rate of E. coli could be remarkably reduced as compared with the case where C12A7 was not supported on the filter base material.

<Comparison of performance between C12A7 and other antibacterial agents>
First, the following tests were conducted for comparison.
20 μL of the bacterial solution was added to 5 mL of physiological saline and mixed. Here, a bacterial solution containing Escherichia coli (NBRC3972) was used. After standing at a temperature of 30 ° C. for 20 minutes, 100 μL of this mixture was smeared on an SCD agar medium. And it culture | cultivated over 36 hours at 36 +/- 1 degreeC, and calculated | required the number of colon_bacillus | E._coli from the number of the formed colonies. As a result, the number of E. coli was about 1 × 10 ³ .

Next, as described below, similar tests were performed using various antibacterial agents.
25 mg of antibacterial agent A1 was added to 50 mL of ion exchange water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of silver powder was added to 50 mL of ion exchange water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  To 50 mL of ion exchange water, 25 mg of magnesium oxide powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  To 50 mL of ion exchange water, 25 mg of titanium dioxide powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

To 50 mL of ion exchange water, 25 mg of zeolite powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.
The results of the above test are summarized in Table 10 below and FIG.

  In Table 10, “E. coli survival rate” is a relative value of the number of E. coli based on the results obtained when physiological saline was used.

  As shown in Table 10 and FIG. 11, when C12A7 was used, superior performance could be achieved as compared with the case where magnesium oxide, titanium dioxide and zeolite were used. Further, when C12A7 was used, almost the same performance as when silver was used could be achieved.

<Effect 1 of other antibacterial agents on the performance of C12A7>
For comparison, the following tests were conducted.
20 μL of the bacterial solution was added to 5 mL of physiological saline and mixed. Here, a bacterial solution containing Escherichia coli (NBRC3972) was used. After standing at a temperature of 30 ° C. for 20 minutes, 100 μL of this mixture was smeared on an SCD agar medium. And it culture | cultivated over 36 hours at 36 +/- 1 degreeC, and calculated | required the number of colon_bacillus | E._coli from the number of the formed colonies.

In addition, as described below, similar tests were performed using various antibacterial agents.
25 mg of antibacterial agent A1 was added to 50 mL of ion exchange water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  To 50 mL of ion exchange water, 2.5 mg of silver powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  To 50 mL of ion exchange water, 2.5 mg of magnesium oxide powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  To 50 mL of ion exchange water, 2.5 mg of titanium dioxide powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  To 50 mL of ion exchange water, 2.5 mg of zeolite powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

Furthermore, as described below, the same test was performed by combining C12A7 and other antibacterial agents.
25 mg of antibacterial agent A1 and 2.5 mg of silver powder were added to 50 mL of ion-exchanged water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of antibacterial agent A1 and 2.5 mg of magnesium oxide powder were added to 50 mL of ion-exchanged water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of antibacterial agent A1 and 2.5 mg of titanium dioxide powder were added to 50 mL of ion exchange water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

25 mg of antibacterial agent A1 and 2.5 mg of zeolite powder were added to 50 mL of ion-exchanged water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.
The results of the above test are summarized in Table 11 below and FIG.

  In Table 11, “E. coli survival rate” is a relative value of the number of E. coli based on the results obtained when physiological saline was used.

  As shown in Table 11 and FIG. 12, when C12A7 was used as at least a part of the antibacterial agent, it was superior to the case where silver, magnesium oxide, titanium dioxide or zeolite was used as the antibacterial agent. The performance could be achieved. Moreover, when C12A7 and silver or magnesium oxide were used in combination as an antibacterial agent, superior performance could be achieved as compared with the case where only C12A7 was used as the antibacterial agent.

<Effect 2 of other antibacterial agents on C12A7 performance>
For comparison, the following tests were conducted.
20 μL of the bacterial solution was added to 5 mL of physiological saline and mixed. Here, a bacterial solution containing Escherichia coli (NBRC3972) was used. After standing at a temperature of 30 ° C. for 20 minutes, 100 μL of this mixture was smeared on an SCD agar medium. And it culture | cultivated over 36 hours at 36 +/- 1 degreeC, and calculated | required the number of colon_bacillus | E._coli from the number of the formed colonies.

In addition, as described below, similar tests were performed using various antibacterial agents.
25 mg of antibacterial agent A1 was added to 50 mL of ion exchange water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of silver powder was added to 50 mL of ion exchange water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  To 50 mL of ion exchange water, 25 mg of magnesium oxide powder was added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

Furthermore, as described below, the same test was performed by combining C12A7 and other antibacterial agents.
25 mg of antibacterial agent A1 and 2.5 mg of silver powder were added to 50 mL of ion-exchanged water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of antibacterial agent A1 and 12.5 mg of silver powder were added to 50 mL of ion-exchanged water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  In 50 mL of ion exchange water, 25 mg of antibacterial agent A1 and 25 mg of silver powder were added. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of antibacterial agent A1 and 2.5 mg of magnesium oxide powder were added to 50 mL of ion-exchanged water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of antibacterial agent A1 and 12.5 mg of magnesium oxide powder were added to 50 mL of ion-exchanged water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

  25 mg of antibacterial agent A1 and 25 mg of magnesium oxide powder were added to 50 mL of ion exchange water. This was sufficiently stirred and allowed to stand for 2 hours. A test similar to the comparative test described above was performed, except that 5 mL of the supernatant thus obtained was used instead of physiological saline.

The results of the above test are summarized in Table 12 below and FIG.

  In Table 12, “E. coli survival rate” is a relative value of the number of E. coli based on the results obtained when physiological saline was used.

  As shown in Table 12 and FIG. 13, when C12A7 and silver were combined, the antibacterial property was improved by increasing the amount of silver added. On the other hand, when C12A7 and magnesium oxide are combined, when the addition amount of magnesium oxide is small, the antibacterial property is hardly improved, and when the addition amount of magnesium oxide is 250 ppm and 500 ppm, only C12A7 is used as an antibacterial agent. Excellent antibacterial properties were achieved compared to the case of using.

  DESCRIPTION OF SYMBOLS 1 ... Mask, 2 ... Mask main body, 21 ... Filter, 21a ... Filter material, 21a1 ... Filter base material, 21a2 ... Antibacterial agent, 21b ... Surface layer material, 22 ... Holding member, 23 ... Shaped member, 2a ... Face body, 2b ... Filter unit, 2b1 ... Holder, 3 ... Fixing tool, P1 ... Folded part, P2 ... Folded part, P3 ... Folded part, W ... Wearer.

Claims (4)

  A filter for a mask, comprising: a filter base material that allows breath to permeate; and a compound that is supported on the filter base material and has a mayenite structure. The part of the filter base material through which the breath passes when the mask is worn has a ratio between the mass of the compound carried by the part and the area of the part of 10 g / m ² or more. The filter described.   The filter according to claim 1, further comprising an antibacterial agent carried on the filter base material, wherein the antibacterial agent includes at least one of silver and magnesium oxide.   A mask comprising the filter according to claim 1 and a fixture for fixing the filter to a wearer.

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