JPWO2019156157A1 - Manufacturing method of filter filter media, filter filter media and respirator - Google Patents

Abstract

On one side of the first nonwoven fabric 12 basis weight spunbond nonwoven ^{10g / m 2 ~50g / m 2} , the basis weight of the nanofiber having an average fiber diameter of 100nm~400nm is 0.05g ^/ m 2 ~0.2g nanofibers laminating step of forming a second nonwoven 14 are laminated so that / ^{m 2,} a bonding step of basis weight to adhere the third nonwoven 16 is a meltblown nonwoven fabric ^5g / ^{m 2 ~30g} / m 2 Is included in this order, and the total thickness is 0.05 mm to 0.4 mm. Further, a filter filter medium 10 manufactured by the above method for manufacturing a filter filter medium and a respirator 100 using the filter filter medium 10.
According to the method for manufacturing a filter filter medium of the present invention, the filter filter medium 10 can be made thinner and lighter while maintaining high collection performance, and is less likely to be deteriorated or damaged than the conventional method for manufacturing a filter filter medium. It becomes possible to manufacture.

Description

The present invention relates to a method for producing a filter filter medium, a filter filter medium and a respirator.

Products equipped with a filter using a fibrous substance and collecting (removing) particles and the like existing in air or liquid are widely used for various purposes.

Among products equipped with filters, respirators (respiratory protective equipment. A type of highly airtight mask used as dustproof masks, medical masks, infection prevention masks, etc.) are used in dusty work sites, operating rooms, etc. It is expected to be used in particularly severe environments such as wards and sites for pandemic (influenza, etc.) countermeasures (for example, examination rooms). Therefore, the filter of the respirator is required to have high collection performance. In addition, since the respirator is expected to be used for a long time or frequently due to its intended use, the filter of the respirator is also required to reduce the load on the user while wearing it.

As the filter of the respirator, a filter using a non-woven fabric (for example, melt blown non-woven fabric) made of fibers having a fiber diameter of micrometer class or larger (hereinafter, referred to as ordinary fibers) is generally used. However, if a non-woven fabric made of ordinary fibers is used to achieve higher collection performance, the filter will inevitably become thicker. The thicker the filter, the higher the heat insulating property (heat retention), which causes fatigue and discomfort due to sweating and the like. In addition, the thicker the filter, the higher the sound absorption property, which makes it difficult for the voice to be transmitted to the outside, which may make it difficult to communicate while wearing the respirator.

For this reason, the respirator provided with a filter using a non-woven fabric made of ordinary fibers has a problem that the load applied to the wearer becomes large when trying to obtain high collection performance, and high collection performance is maintained. There is a strong demand for thinner and lighter filters.

In order to achieve thinning and weight reduction while maintaining high collection performance, it is preferable to make the fibers constituting the filter finer. Therefore, a technique using nanofibers having a nanoscale fiber diameter is drawing attention.

However, the nanofiber non-woven fabric made of nanofibers is basically formed in a plane due to the forming method and the fiber diameter. Therefore, it is difficult to stack nanofibers thickly. Therefore, when high collection performance is to be obtained only with the nanofiber non-woven fabric, the nanofibers are formed at a high density to obtain a dense nanofiber non-woven fabric. However, if the nanofiber non-woven fabric is excessively densified, it becomes difficult to breathe due to an increase in pressure loss, and even a respirator provided with a filter using the nanofiber non-woven fabric may rather increase the load on the wearer.

For the above reasons, it is considered preferable to use a combination of a non-woven fabric made of ordinary fibers and a nanofiber non-woven fabric as the filter of the respirator.
Conventionally, a method for producing a filter filter medium in which a non-woven fabric made of ordinary fibers and a nanofiber non-woven fabric are combined is known (see, for example, Patent Document 1).

The conventional method for manufacturing a filter filter medium is a step of laminating nanofibers on one side of a melt-blown non-woven fabric to form a nanofiber non-woven fabric, and a hot-melt resin is sprayed on one side of a thermal-bonded non-woven fabric to heat and melt the resin. The step and the step of adhering each non-woven fabric with the heat-melted resin are included in this order.

According to the conventional method for manufacturing a filter filter medium, it is possible to manufacture a filter filter medium that can achieve thinning and weight reduction while maintaining high collection performance by combining a non-woven fabric made of ordinary fibers and a nanofiber non-woven fabric. It will be possible.

Japanese Patent No. 6172924

However, as a result of diligent research by the inventor of the present invention, it has been found that the conventional method for producing a filter filter medium has a problem that the produced filter filter medium is easily deteriorated or damaged.

The present invention has been made to solve the above-mentioned problems, and can achieve thinning and weight reduction while maintaining high collection performance, and is deteriorated or damaged as compared with the conventional method for manufacturing a filter filter medium. An object of the present invention is to provide a method for producing a filter filter medium, which is capable of producing a difficult filter filter medium. Another object of the present invention is to provide a filter filter medium that can be made thinner and lighter while maintaining high collection performance, and is less likely to deteriorate or break than a filter filter medium manufactured by a conventional method for manufacturing a filter filter medium. To do. Furthermore, it achieves both high collection performance and a small load on the wearer, and is less likely to deteriorate or break the filter than a respirator that uses a filter filter medium manufactured by a conventional filter filter medium manufacturing method as a filter. It also aims to provide a respirator.

[1] The method for producing a filter medium of the present invention, on one side of the first nonwoven basis weight is spunbond nonwoven fabric in the range of ^{10g / m 2 ~50g / m 2} , average fiber diameter of 100nm~400nm A nanofiber laminating step of laminating nanofibers within the range so that the grain size is ^{within the range of 0.05 g / m 2 to} 0.2 g / m ² to form a second non-woven fabric, and the first non-woven fabric. on the surface of the second nonwoven fabric opposite to basis weight that order and an adhesive bonding a third nonwoven is electret meltblown nonwoven is in the range of 5g / m ² ~30g / m ² The total thickness of the first non-woven fabric, the second non-woven fabric, and the third non-woven fabric is within the range of 0.05 mm to 0.4 mm.

According to the method for producing a filter filter medium of the present invention, as in the conventional method for producing a filter filter medium, by combining a non-woven fabric made of ordinary fibers and a nanofiber non-woven fabric, the thickness can be reduced while maintaining high collection performance. It becomes possible to manufacture a filter filter medium that can achieve weight reduction.

By the way, the melt-blown non-woven fabric has a property of being easily charged as compared with a spun-bonded non-woven fabric or a thermal-bonded non-woven fabric. For this reason, when nanofibers are laminated on one side of the melt-blown non-woven fabric as in the conventional method for manufacturing a filter filter medium, the melt-blow non-woven fabric is charged and electrical repulsion is generated with the nanofibers, so that the nanofibers are laminated. May not work, or uneven stacking may occur. As a result, the filter filter medium manufactured by the conventional filter manufacturing method is liable to be deteriorated or damaged (particularly due to peeling of the melt-blown non-woven fabric and the nanofiber non-woven fabric or a decrease in strength due to the peeling).

On the other hand, according to the method for producing a filter filter medium of the present invention, nanofibers are laminated on one side of a first nonwoven fabric, which is a spunbonded nonwoven fabric that is relatively hard to be charged, to form a second nonwoven fabric. It is possible to appropriately stack nanofibers by reducing the electrical repulsion that occurs between them. As a result, according to the method for producing a filter filter medium of the present invention, it is possible to produce a filter filter medium that is less likely to be deteriorated or damaged than the filter filter medium produced by the conventional method for producing a filter filter medium.

Therefore, the method for manufacturing the filter filter medium of the present invention can achieve thinning and weight reduction while maintaining high collection performance, and is less likely to deteriorate or break than the conventional method for manufacturing the filter filter medium. This is a method for manufacturing a filter medium that can be manufactured.

Further, according to the method for producing a filter filter medium of the present invention, it is possible to appropriately laminate nanofibers by forming a second non-woven fabric on one side of a first non-woven fabric which is a spunbonded non-woven fabric which is relatively hard to be charged. Therefore, by forming a high-quality nanofiber non-woven fabric, it is possible to improve the collection performance per thickness. As a result, according to the method for producing a filter filter medium of the present invention, it is possible to produce a filter filter medium capable of ensuring high collection performance even if it is thinner than the filter filter medium produced by the conventional method for producing a filter filter medium. It will be possible.

Further, according to the method of manufacturing the filter medium of the present invention, since the basis weight of the first nonwoven fabric is a spunbonded nonwoven fabric is in the range of ^{10g / m 2 ~50g / m 2} , basis weight 10 g / ^{m 2} or more This makes it possible to secure sufficient tensile strength to prevent abnormalities (tear, breakage, elongation, etc.) when forming the second non-woven fabric made of nanofibers, and the grain size is 50 g / m ² or less. Therefore, the insulating property of the spunbonded non-woven fabric can be sufficiently lowered to sufficiently increase the bonding force between the first non-woven fabric and the second non-woven fabric, and the weight of the filter filter medium can be reduced.

Further, according to the method for producing a filter filter medium of the present invention, since the average fiber diameter of nanofibers is in the range of 100 nm to 400 nm, it is necessary to secure a practical production amount by setting the average fiber diameter to 100 nm or more. By setting the average fiber diameter to 400 nm or less, it is possible to sufficiently increase the collection performance and sufficiently reduce the pressure loss.

Further, according to the method of manufacturing the filter medium of the present invention, to laminate to the basis weight of the nanofiber is in the range of ^{0.05g / m 2 ~0.2g / m 2} , the basis weight 0.05g By setting the weight to / m ² or more, the collection performance can be sufficiently high, and by setting the basis weight to 0.2 g / m ² or less, the pressure loss can be sufficiently lowered.

In addition, according to the manufacturing method of the filter medium of the present invention, since the basis weight of the third nonwoven is meltblown nonwoven fabric is in the range of ^{5g / m 2 ~30g / m 2} , the basis weight is 5 g / ^{m 2} or more This makes it possible to ensure ease of handling during bonding (stability of behavior during bonding process such as lamination, heating, pressurization, cooling, etc., so-called handleability), and the amount of grain is 30 g. When it is / m ² or less, the thickness of the third non-woven fabric in the thickness direction can be reduced to achieve a thinner filter filter medium.

Further, according to the method for producing a filter filter medium of the present invention, since the third nonwoven fabric is an electretized melt-blown nonwoven fabric, it is possible to obtain high collection performance due to electrostatic force.

In the method for producing a filter filter medium of the present invention, in the nanofiber laminating step, it is preferable to laminate the nanofibers using a multi-nozzle type electrospinning device in which the spinning direction is from bottom to top.

By using such a method, nanofibers can be laminated uniformly and efficiently.

In the method for producing a filter medium of the present invention, it is preferable to bond the third nonwoven fabric by hot melt using a resin adhesive in the bonding step.

By adopting such a method, it is possible to stably bond the third non-woven fabric, which is an electretized melt-blown non-woven fabric.

In the method for producing a filter medium of the present invention, it is preferable that the third nonwoven fabric is made of polypropylene as a raw material.

Polypropylene is a easily charged raw material suitable for electret formation.
Therefore, by adopting the above method, it is possible to suppress the attenuation of the effect of electretization and suppress the deterioration of the collection performance of the filter filter medium over time.

In the method for producing a filter filter medium of the present invention, in the nanofiber laminating step, the second nonwoven fabric is made of the nanofibers made from at least one of thermoplastic polyurethane, polyvinylidene fluoride, polyamide, polyacrylonitrile and polyvinyl alcohol. It is preferable to form.

By adopting such a method, it is possible to stably form a second non-woven fabric having high collection performance.

[2] In the method for producing a filter medium of the present invention, it is preferable to use the third nonwoven fabric having a uniform structure throughout.

By using such a method, the third non-woven fabric can be uniformly adhered to the surface of the second non-woven fabric by using the third non-woven fabric having less unevenness in thickness and density, and as a result, deterioration or damage (deterioration or damage () In particular, it is possible to manufacture a filter filter medium that is less likely to cause deterioration or breakage when the fluid is used in a non-constant flow direction.

Further, by adopting such a method, it is possible to reduce the internal space of the filter filter medium (a space that is not the inside of any non-woven fabric), and as a result, a filter filter medium having high shape stability and backwash performance can be manufactured. It becomes possible to do.

[3] filter medium of the present invention, a first nonwoven basis weight spunbond nonwoven fabric in the range of ^{10g / m 2 ~50g / m 2} , is disposed on one side of the first nonwoven fabric, the average fiber diameter a second nonwoven is a nanofiber nonwoven fabric basis weight consists nanofiber is in the range of 0.05g ^{/ m 2} ~0.2g ^/ m 2 but within range of 100 nm to 400 nm, said second nonwoven the first nonwoven fabric is disposed on the opposite side, and a third nonwoven basis weight is electret meltblown nonwoven is in the range of ^{5g / m 2 ~30g / m 2} , the first The non-woven fabric and the second non-woven fabric are integrated by contact and entanglement between the fibers constituting the respective non-woven fabric, and the thickness is in the range of 0.05 mm to 0.4 mm.

According to the filter filter medium of the present invention, by combining a non-woven fabric made of ordinary fibers and a nanofiber non-woven fabric, it is possible to achieve thinning and weight reduction while maintaining high collection performance.

Further, according to the filter filter medium of the present invention, the second non-woven fabric is integrated on one side of the first non-woven fabric, which is a spunbonded non-woven fabric that is relatively hard to be charged, by contacting and entwining the fibers constituting the respective non-woven fabrics. The electrical repulsion generated between the first non-woven fabric and the nanofibers during manufacturing can be reduced, and the second non-woven fabric and the first non-woven fabric can be firmly integrated. As a result, the filter filter medium of the present invention becomes a filter filter medium that is less likely to deteriorate or break than the filter filter medium manufactured by the conventional method for manufacturing a filter filter medium.

Therefore, the filter filter medium of the present invention can achieve thinning and weight reduction while maintaining high collection performance, and is less likely to deteriorate or break than the filter filter medium manufactured by the conventional filter filter medium manufacturing method. It becomes a filter medium.

Further, according to the filter filter medium of the present invention, since the second non-woven fabric is integrated on one side of the first non-woven fabric, which is a spunbonded non-woven fabric that is relatively hard to be charged, the nanofibers can be appropriately laminated at the time of manufacturing. This makes it possible to improve the collection performance per thickness as a high-quality nanofiber non-woven fabric. As a result, according to the filter filter medium of the present invention, it is possible to secure high collection performance even as a filter filter medium thinner than the conventional filter filter medium.

Since each numerical range and the effect of electretization described for the filter filter medium in [3] above are the same as the effect described in [1] above, the description is omitted here.

[4] In the filter medium of the present invention, it is preferable that the third nonwoven fabric has a uniform structure throughout.

With such a configuration, by using the third non-woven fabric having less unevenness in thickness and density, it is possible to uniformly adhere the third non-woven fabric on the surface of the second non-woven fabric and increase the adhesive strength. As a result, it is possible to make it difficult for deterioration and breakage (particularly, deterioration and breakage when the fluid flow direction is not constant) to occur.

Further, with such a configuration, it is possible to reduce the internal space of the filter filter medium, and as a result, it is possible to improve the shape stability and the backwash performance.

[5] The filter filter medium of the present invention preferably satisfies the N95 standard.

With such a configuration, it is possible to use a filter filter medium for use in a respirator that is particularly suitable for use in a particularly severe environment such as a dust-generating work site, an operating room, a ward, or a pandemic countermeasure site. It becomes.

[6] In the filter filter medium of the present invention, test particles of JIS8 type are deposited on the first non-woven fabric side while sucking air, and the pressure loss is 1.5 times the pressure loss before the test particles are deposited. After that, the pressure loss after sending exhaled air having an average surface wind velocity of 26 cm / s 5 times for 1 second from the third non-woven fabric side is 1.1 times the pressure loss before depositing the test particles. The following is preferable.

Conventionally, as a filter filter medium used for a respirator, there is a filter filter medium (particularly, a filter filter medium that meets the N95 standard) that can easily perform sufficient backwashing even if there is a filter medium having a high collection performance. I didn't.
With the above configuration, it is possible for an adult to perform sufficient backwashing to the extent that a strong exhaled breath is sent.

[7] the respirator of the present invention, a first nonwoven basis weight spunbond nonwoven fabric in the range of ^{10g / m 2 ~50g / m 2} , is disposed on one side of the first nonwoven fabric, the average fiber diameter a second nonwoven fabric weight consists nanofibers are within the scope of 100nm~400nm is nanofiber nonwoven fabric is in the range of ^{0.05g / m 2 ~0.2g / m 2} , it said second nonwoven first 1 the nonwoven fabric is disposed on the opposite side, and a third nonwoven basis weight is electret meltblown nonwoven is in the range of ^{5g / m 2 ~30g / m 2} , the first non-woven fabric And the second non-woven fabric are integrated by contact and entanglement of fibers constituting each non-woven fabric, and a filter filter medium having a thickness in the range of 0.05 mm to 0.4 mm is provided as a component of the filter. It is characterized by that.

Since the respirator of the present invention uses a filter including the filter filter medium of the present invention as a component, both high collection performance and a reduction in the load on the wearer are achieved, and the conventional filter filter medium is used as a component of the filter. It is a respirator that is less likely to deteriorate or break the filter than the respirator used as.

Since the numerical range and the effect of electretization described for the respirator in [7] above are the same as the effect described in [1] above, the description is omitted here.

[8] In the respirator of the present invention, the total thickness of the filter is preferably in the range of 0.2 mm to 1.5 mm.

With such a configuration, it is possible to achieve sufficient thinning and weight reduction of the filter while ensuring sufficient strength of the filter.

[9] In the respirator of the present invention, the filter preferably has a plain surface shape.

With such a configuration, it is possible to prevent a decrease in collection performance due to the formation of embossing or the like.

In addition, "the surface shape is plain" in this specification means that it does not have a three-dimensional shape (for example, unevenness for increasing the surface area of the filter) which is not indispensable from the viewpoint of forming the shape of the respirator. .. For example, in order to make a foldable respirator, even if the filter has creases, if the above-mentioned three-dimensional shape does not exist, the condition that "the surface shape is plain" is satisfied.

[10] In the respirator of the present invention, it is preferable that the third nonwoven fabric has a uniform structure throughout.

With such a configuration, by using the third non-woven fabric having less unevenness in thickness and density, it is possible to uniformly adhere the third non-woven fabric on the surface of the second non-woven fabric and increase the adhesive strength. As a result, it is possible to make it difficult for deterioration and breakage (particularly, deterioration and breakage when the fluid flow direction is not constant) to occur.

Further, with such a configuration, it is possible to reduce the internal space of the filter filter medium, and it is possible to improve the shape stability and the backwash performance.

[11] In the respirator of the present invention, it is preferable to have a non-woven fabric on the mouth side made of a thermal-bonded non-woven fabric as a component of the filter.

With such a configuration, it is possible to prevent the mouth from coming into direct contact with the filter filter medium, and it is possible to prevent the filter filter medium from being damaged.

[12] In the respirator of the present invention, it is preferable that the filter filter medium and the non-woven fabric on the mouth side are joined at their respective ends.

With such a configuration, it is possible to prevent the filter filter medium from being pulled by the movement of the non-woven fabric on the mouth side and applying an excessive load to the filter filter medium.

[13] In the respirator of the present invention, it is preferable to satisfy the N95 standard.

With such a configuration, it is possible to make the respirator particularly suitable for use in a particularly severe environment such as a dust-generating work site, an operating room, a ward, or a pandemic countermeasure site.

[14] In the respirator of the present invention, test particles of JIS8 type are deposited on the first non-woven fabric side while sucking air, and the pressure loss is 1.5 times the pressure loss before the test particles are deposited. After that, the pressure loss after sending exhaled air having an average surface wind velocity of 26 cm / s 5 times for 1 second from the third non-woven fabric side is 1.1 times or less of the pressure loss before depositing the test particles. Is preferable.

Conventionally, in the technical field of respirators, there is no respirator (particularly, a respirator that meets the N95 standard) that can easily perform sufficient backwashing even if there is a respirator with high collection performance. It was.
With the above configuration, it is possible for an adult to perform sufficient backwashing to the extent that a strong exhaled breath is sent.

It is sectional drawing of the filter filter medium 10 which concerns on embodiment. It is a figure which shows for demonstrating the nanofiber laminating step S1 in the manufacturing method of the filter filter medium which concerns on embodiment. It is a figure which shows for demonstrating the adhesion process S2 in the manufacturing method of the filter filter medium which concerns on embodiment. It is a figure which shows for demonstrating the respirator 100 which concerns on embodiment. It is a figure which shows the state of using the respirator 100 which concerns on embodiment. It is a table which shows the experimental result which concerns on Example and comparative example. It is a schematic diagram which shows the structure of the experimental apparatus 400 used for the experiment in additional Example 1. FIG. It is a graph which shows the result of the experiment in additional Example 1. It is an SEM image which shows the state after suction of the test particle of each respirator in the additional Example 2.

Hereinafter, the method for producing the filter filter medium of the present invention, the filter filter medium and the respirator will be described based on the embodiments shown in the figure. Each drawing is a schematic view and does not necessarily accurately reflect the actual structure or configuration. The embodiments described below do not limit the invention according to the claims. Moreover, not all of the elements and combinations thereof described in the embodiments are essential to the present invention.

[Embodiment]
1. 1. Filter filter medium 10
First, the filter filter medium 10 according to the embodiment will be described.
FIG. 1 is a cross-sectional view of the filter medium 10 according to the embodiment.
As shown in FIG. 1, the filter filter medium 10 according to the embodiment includes a first non-woven fabric 12, a second non-woven fabric 14, and a third non-woven fabric 16. The filter medium 10 has a thickness in the range of 0.05 mm to 0.4 mm.
As used herein, the term "filter filter medium" refers to a filter medium used as a component of a filter, which has a filtering (collecting) function which is a main function of the filter. The filter filter medium may be used alone as a filter, or may be laminated or integrated with other components (for example, a non-woven fabric for the mouth, a non-woven fabric for reinforcement, another filter filter medium, etc.).

The first nonwoven 12, basis weight spunbond nonwoven fabric in the range of ^{10g / m 2 ~50g / m 2} . The first non-woven fabric 12 is made of polypropylene (PP) as a raw material, for example.

The second non-woven fabric 14 is arranged on one side of the first non-woven fabric 12. The second nonwoven 14, weight per unit area of an average fiber diameter of the nanofibers in the range of 100nm~400nm is nanofiber nonwoven fabric is in the range of ^{0.05g / m 2 ~0.2g / m 2} .
The second nonwoven fabric 14 is formed of nanofibers made from at least one of thermoplastic polyurethane (TPU), polyvinylidene fluoride (PVDF), polyamide (PA), polyacrylonitrile (PAN) and polyvinyl alcohol (PVA). ing.

The third nonwoven 16, the first nonwoven fabric 12 of the second nonwoven fabric 14 is disposed on the opposite side, in electret meltblown nonwoven is in the range basis weight of ^5g / ^{m 2 ~30g} / m 2 is there. The third non-woven fabric 16 is made of polypropylene (PP) as a raw material.
The electreted melt-blown non-woven fabric can collect relatively large collection targets by the fiber itself, and at the same time, it can collect relatively small collection targets by the action of electrostatic force, so the collection performance of the filter filter medium is high. It is a component suitable for doing so.

Further, the third nonwoven fabric 16 has a uniform structure throughout.
In the present specification, the third non-woven fabric has a structure in which there is no significant difference in thickness, density and fiber entanglement regardless of the portion, or the thickness, density and fiber entanglement are intentionally provided. Having a structure without any difference is called "having a uniform structure".

The third nonwoven fabric 16 having a uniform structure does not have a region in which the average thickness is different from the average thickness in other regions. Further, the third nonwoven fabric 16 does not have a structure like protrusions. The protrusion referred to here is a structure that protrudes from the flat surface (main surface) portion of the non-woven fabric, and has a density or structure different from that of the flat surface portion of the non-woven fabric (for example, a pill). The presence or absence of the protrusion can be identified by, for example, transmitting the third non-woven fabric 16 through light. When the third non-woven fabric 16 is transparent to light, the portion where the protruding portion exists appears to have a darker shadow than the other portion.

By using a third non-woven fabric having a uniform structure like the filter filter medium 10 according to the embodiment, a third non-woven fabric having a non-uniform structure (for example, a structure such as a third non-woven fabric having a non-uniform thickness or protrusions) can be used. Compared with the case of using the third non-woven fabric having), it has the effects as described in the following (a) to (e).

(A) The thickness of the filter medium can be made uniform evenly.
(B) Since the third non-woven fabric does not have an unnecessarily thick region or protrusion, it is possible to prevent the filter medium from becoming unnecessarily thick (maintaining thinness).
(C) Structural non-uniformity (particularly protrusions) is mainly formed by post-processing (for example, friction by a roll or spatula), but when a third non-woven fabric having a uniform structure is used, post-processing is performed. Since it is not necessary to perform the above, it is possible to prevent an increase in processing cost and equipment cost related to post-processing.
(D) Since the structure of the third non-woven fabric is not physically changed by post-processing, the size and shape of the holes in the third non-woven fabric are not forcibly changed, and the particle collection performance of the filter filter medium is not deteriorated. It becomes possible to.
(E) Compared with the case of using a third non-woven fabric that does not have a uniform structure, the gaps (gap between layers) caused by protrusions and the like are reduced, so that the second non-woven fabric (nanofiber non-woven fabric) collects particles. When this is done, the second non-woven fabric can be sufficiently supported, and as a result, damage to the second non-woven fabric can be suppressed.

The first non-woven fabric 12 and the second non-woven fabric 14 are integrated by contact and entanglement of fibers constituting the respective non-woven fabrics. The integration can be achieved by forming the second nonwoven fabric 14 by an electrospinning method (see the nanofiber laminating step S1 of the method for manufacturing a filter filter medium described later).
Further, the first non-woven fabric 12, the second non-woven fabric 14, and the third non-woven fabric 16 are adhered with a resin adhesive. As the method for bonding, for example, hot melt can be used (see the bonding step S2 of the method for manufacturing a filter filter medium described later).

With the above configuration, the filter filter medium 10 preferably satisfies the N95 standard.

In the filter filter medium 10, the test particles of JIS8 type are deposited on the first non-woven fabric 12 side while sucking air, and the pressure loss becomes 1.5 times the pressure loss before the test particles are deposited. The pressure loss after sending exhaled air having an average surface wind velocity of 26 cm / s from the non-woven fabric side five times for each second is 1.1 times or less of the pressure loss before depositing the test particles (additional examples described later). See also 1.).

2. Method for manufacturing filter filter medium Next, a method for manufacturing the filter filter medium according to the embodiment will be described.
The method for producing the filter material according to the embodiment includes the nanofiber laminating step S1 and the bonding step S2 in this order. Hereinafter, each step will be described.

2-1. Nanofiber lamination process S1
FIG. 2 is a diagram shown for explaining the nanofiber laminating step S1 in the method for manufacturing a filter filter medium according to an embodiment. FIG. 2A is a schematic view showing how the nanofiber laminating step S1 is carried out, FIG. 2B is a cross-sectional view showing the state of the position of A1 in FIG. 2A, and FIG. 2C. ) Is a cross-sectional view showing the state of the position of A2 in FIG. 2 (a).

Nanofibers lamination step S1 is, as shown in FIG. 2, the first nonwoven 12 basis weight spunbond nonwoven fabric in the range of ^10g / ^{m 2 ~50g} / m 2 (see FIG. 2 (b).) on one side, forming a second nonwoven 14 laminated nanofibers average fiber diameter is within the range of 100nm~400nm such basis weight is in the range of 0.05g ^{/ m 2} ~0.2g ^/ m 2 (See FIG. 2 (c)).

In the nanofiber laminating step S1, nanofibers made from at least one of thermoplastic polyurethane (TPU), polyvinylidene fluoride (PVDF), polyamide (PA), polyacrylonitrile (PAN) and polyvinyl alcohol (PVA) are used as raw materials. 2 Form the non-woven fabric 14.
In the nanofiber laminating step S1, as shown in FIG. 2A, nanofibers are laminated using a multi-nozzle type electrospinning apparatus 200 in which the spinning direction is from bottom to top.

In FIG. 2A, reference numeral 210 is a feeding roll for feeding out the first nonwoven fabric 12, and reference numeral 212 is a winding roll for winding the first nonwoven fabric 12 and the second nonwoven fabric 14. In the present embodiment, the first non-woven fabric 12 and the second non-woven fabric 14 are wound up by the take-up roll 212 while the first non-woven fabric 12 is unwound from the feeding roll 210, so that the second non-woven fabric 14 is wound on one side of the first non-woven fabric 12. The formation (lamination of nanofibers) is performed continuously.
In this case, the basis weight of the second nonwoven fabric 14 can be adjusted by changing the speed at which the first nonwoven fabric 12 is moved, changing the injection amount of the nanofiber raw material, increasing or decreasing the applied voltage, and the like.

The formation of the second non-woven fabric does not have to be continuous. For example, a first non-woven fabric having a predetermined area is prepared to form a second non-woven fabric, and then another first non-woven fabric having a predetermined area is prepared to form a second non-woven fabric again. The formation of the second non-woven fabric may be intermittent.

2-2. Adhesion process S2
FIG. 3 is a diagram shown for explaining the bonding step S2 in the method for manufacturing the filter filter medium according to the embodiment. FIG. 3A is a schematic view showing how the bonding step S2 is performed, FIG. 3B is a cross-sectional view showing the position of A3 in FIG. 3A, and FIG. 3C is a cross-sectional view. 3 (a) is a cross-sectional view showing the state of the position of A4 in FIG. 3 (a), and FIG. 3 (d) is a cross-sectional view showing the state of the position of A5 in FIG. 3 (a).

Bonding process S2, as shown in FIG. 3, the first nonwoven fabric 12 on the surface of the second nonwoven fabric 14 on the opposite side are electret basis weight is within the range of ^5g / ^{m 2 ~30g} / m 2 This is a step of adhering the third non-woven fabric 16 which is a melt-blown non-woven fabric. The third nonwoven fabric 16 is made of polypropylene (PP) as a raw material as described above. Since the electretization of the non-woven fabric is known, the description thereof will be omitted.

In the bonding step S2, the third nonwoven fabric 16 having a uniform structure throughout is used.

In the bonding step S2, the third non-woven fabric 16 is bonded by hot melt using a resin adhesive. In the hot melt, for example, as shown in FIG. 3 (a), the thermoplastic resin adhesive 18 is sprayed or applied on the second non-woven fabric 14 by the resin adhesive coating machine 300 (see FIG. 3 (b)). The third non-woven fabric 16 is superposed on the second non-woven fabric 14 via the resin adhesive 18 (see FIG. 3C), and the resin adhesive 18 is melted by heating with a heating heater 310 to melt the first non-woven fabric 12 and the second non-woven fabric. The non-woven fabric 14 and the third non-woven fabric 16 are adhered to each other (see FIG. 3D).
In addition, in FIGS. 3A to 3C, the resin adhesive 18 is displayed as having a granular shape arranged at equal intervals, but this is for convenience. The resin adhesive should be in any (appropriate) form (reticulated or linear shape, solid, paste, gel, etc.) as long as the purpose of properly adhering the third non-woven fabric can be achieved. It can be used and can be sprayed, applied, arranged, etc. by any (appropriate) distribution and method.

In the present embodiment, the filter filter medium 10 is manufactured by carrying out the bonding step S2.

In FIG. 3A, reference numeral 320 is a feeding roll for feeding out the first non-woven fabric 12 and the second non-woven fabric 14, and reference numeral 322 is a feeding roll for feeding out the third non-woven fabric 16, which is indicated by reference numeral 324. Is a take-up roll for winding the filter media 10.
In the present embodiment, each non-woven fabric is unwound from the pay-out roll 320 and the pay-out roll 322, and the filter media 10 is wound by the take-up roll 324 to move each non-woven fabric, and the filter filter medium 10 is continuously manufactured.
As in the case of forming the second non-woven fabric described above, the adhesion of the third non-woven fabric may not be continuous (or intermittent).

In the present embodiment, the total thickness of the first nonwoven fabric 12, the second nonwoven fabric 14, and the third nonwoven fabric 16 is within the range of 0.05 mm to 0.4 mm.

3. 3. Respirator 100
Next, the respirator 100 according to the embodiment will be described.
FIG. 4 is a diagram shown for explaining the respirator 100 according to the embodiment. 4 (a) is a plan view of the respirator 100 in a folded state, FIG. 4 (b) is a sectional view taken along the line AA of FIG. 4 (a), and FIG. 4 (c) is a sectional view of FIG. 4 (b). It is sectional drawing which shows the state of the position shown by A6. In addition, in FIG. 4B, in order to make it easy to understand how the filter 20 is folded, the respirator 100 is shown not in a completely folded state but in a slightly opened state.
FIG. 5 is a diagram showing a state in which the respirator 100 according to the embodiment is used. In FIG. 5, the reference numeral U is the user of the respirator 100. When focusing on the respirator 100, FIG. 5 can be said to be a perspective view showing a state when the respirator 100 is in use (when deployed).

Respirator 100 according to the embodiment, as shown in FIG. 4, the first nonwoven fabric 12 is a spunbonded nonwoven fabric with a basis weight in the range of ^{10g / m 2 ~50g / m 2} , on one side of the first nonwoven fabric 12 are arranged, the second nonwoven 14 basis weight consists nanofibers average fiber diameter is within the range of 100nm~400nm is nanofiber nonwoven fabric is in the range of 0.05g ^{/ m 2} ~0.2g ^/ m 2 , the first nonwoven fabric 12 of the second nonwoven fabric 14 is disposed on the opposite side of the third nonwoven basis weight is electret meltblown nonwoven is in the range of ^{5g / m 2 ~30g / m 2} 16 The first non-woven fabric 12 and the second non-woven fabric 14 are integrated by contact and entanglement of the fibers constituting the respective non-woven fabrics, and the thickness is in the range of 0.05 mm to 0.4 mm. The filter medium 10 is provided as a component of the filter 20.
That is, the respirator 100 includes the filter filter medium 10 according to the embodiment as a component of the filter 20 (in the embodiment, a part of the filter 20).
Therefore, the third nonwoven fabric 16 in the respirator 100 has a uniform structure throughout.

The respirator 100 is foldable. Since the shape of the respirator 100 itself is known, detailed description thereof will be omitted, but as shown in FIG. 4A, the respirator 100 can be folded so as to be substantially trapezoidal when viewed in a plan view. .. When using the respirator 100, the end on the mouth side is opened up and down (see FIG. 4 (b)) and the folded filter 20 is unfolded (see FIG. 5).
The foldable respirator is characterized by its space saving and easy storage and transportation. Since the filter filter medium of the present invention can be made lighter and thinner, it can be particularly preferably used as a filter filter medium used for a foldable respirator.

Further, the respirator 100 preferably satisfies the N95 standard (see Examples described later).

Further, the respirator 100 deposits test particles of JIS8 type on the first non-woven fabric 12 side while sucking air, and the pressure loss becomes 1.5 times the pressure loss before depositing the test particles. 3 The pressure loss after sending exhaled air having an average surface wind velocity of 26 cm / s 5 times for 1 second from the 16 side of the non-woven fabric is 1.1 times or less of the pressure loss before depositing the test particles (addition described later). See also Example 1).

The respirator 100 has a non-woven fabric 22 on the mouth side made of a thermal-bonded non-woven fabric as a component of the filter 20. In the present embodiment, as shown in FIG. 4C, it can be said that the filter 20 is composed of a filter medium 10 and a non-woven fabric 22 on the mouth side made of a thermal-bonded non-woven fabric. In the filter 20, the filter filter medium 10 and the non-woven fabric 22 on the mouth side are joined at their respective ends. That is, the filter filter medium 10 and the non-woven fabric 22 on the mouth side are not bonded (adhered) on the entire surface.
The overall thickness of the filter 20 is in the range of 0.2 mm to 1.5 mm.
Further, the filter 20 has a plain surface shape and does not have embossing or the like.

In addition to the filter 20, the respirator 100 includes a binding tape 30 that fixes the end of the filter 20 by thermocompression bonding, a cover tape 40 that covers the end of the user U that comes into contact with the skin, and a nose of the user U. A nose clamp 50 for ensuring a hermetic seal between the portion and the end of the respirator 100 and a mounting rubber 60 for fixing the respirator 100 to the user U are provided. Since these components are known as components of the respirator, description thereof will be omitted.

The respirator 100 can be manufactured by a known (general) manufacturing method except that the filter 20 including the filter filter medium 10 according to the embodiment is used. As a method for manufacturing the respirator 100 using the filter filter medium 10, (1) a step of cutting the filter filter medium 10 to an appropriate size and (2) laminating the cut filter filter medium 10 and the non-woven fabric 22 on the mouth side are laminated. The process of forming the filter 20, (3) the process of folding the filter 20 into a shape corresponding to the respirator 100, (4) the process of arranging the nose clamp 50 and the mounting rubber 60 at appropriate positions of the filter 20, and (5). ) The process of integrating the filter 20, the nose clamp 50 and the mounting rubber 60 by heat-bonding the binding tape 30 and the cover tape 40, and (6) the process of cutting the filter 20 into a single respirator 100. A method of including in this order can be exemplified.

4. The method for producing a filter filter medium according to the embodiment, the effect of the filter filter medium 10 and the respirator 100.

According to the method for manufacturing a filter filter medium according to the embodiment, as in the conventional method for manufacturing a filter filter medium, by combining a non-woven fabric made of ordinary fibers and a nanofiber non-woven fabric, the thickness is reduced while maintaining high collection performance. And, it becomes possible to manufacture the filter filter medium 10 which can achieve weight reduction.

Further, according to the method for producing a filter filter medium according to the embodiment, nanofibers are laminated on one side of the first nonwoven fabric 12, which is a spunbonded nonwoven fabric that is relatively hard to be charged, to form the second nonwoven fabric 14, so that the first nonwoven fabric is formed. The electrical repulsion generated between the twelve and the nanofibers can be reduced so that the nanofibers can be appropriately laminated. As a result, the method for producing the filter filter medium of the present invention makes it possible to produce the filter filter medium 10 which is less likely to be deteriorated or damaged than the conventional method for producing the filter filter medium.

Therefore, the method for manufacturing the filter filter medium according to the embodiment can achieve thinning and weight reduction while maintaining high collection performance, and is less likely to deteriorate or break than the conventional method for manufacturing the filter filter medium. 10 is a method for producing a filter medium capable of producing the filter medium.

Further, according to the method for producing a filter filter medium according to the embodiment, the nanofibers are appropriately laminated by forming the second nonwoven fabric 14 on one side of the first nonwoven fabric 12, which is a spunbonded nonwoven fabric that is relatively hard to be charged. Therefore, it is possible to improve the collection performance per thickness by forming a high-quality nanofiber non-woven fabric. As a result, according to the method for manufacturing the filter filter medium according to the embodiment, the filter filter medium 10 capable of ensuring high collection performance even if it is thinner than the filter filter medium manufactured by the conventional method for manufacturing the filter filter medium is manufactured. Is possible.

Further, according to the method of manufacturing the filter medium according to the embodiment, since the basis weight of the first nonwoven fabric 12 is a spunbonded nonwoven fabric is in the range of ^{10g / m 2 ~50g / m 2} , basis weight 10 g / m ^{When the number is 2} or more, it is possible to secure sufficient tensile strength to prevent abnormalities (tear, breakage, elongation, etc.) when forming the second non-woven fabric 14 made of nanofibers, and the grain size is 50 g / g. When ^{it is m 2} or less, the insulating property of the spunbonded non-woven fabric can be sufficiently lowered, the bonding force between the first non-woven fabric 12 and the second non-woven fabric 14 can be sufficiently increased, and the weight of the filter filter medium 10 can be reduced. It becomes.

Further, according to the method for producing a filter filter medium according to the embodiment, since the average fiber diameter of nanofibers is in the range of 100 nm to 400 nm, a practical production amount is secured by setting the average fiber diameter to 100 nm or more. By setting the average fiber diameter to 400 nm or less, it is possible to sufficiently increase the collection performance and sufficiently reduce the pressure loss.

Further, according to the method for producing a filter filter medium according to the embodiment, the nanofibers are laminated so that the basis weight is within the range of 0.05 g / m2 to 0.2 g / m2, so that the basis weight is 0.05 g / m. When the amount is m2 or more, the collection performance can be sufficiently high, and when the basis weight is 0.2 g / m2 or less, the pressure loss can be sufficiently reduced.

Further, according to the method for producing the filter filter medium according to the embodiment, since the coating amount of the third nonwoven fabric 16 which is the melt-blown nonwoven fabric is in the ^{range of 5 g / m 2 to} 30 g / m ² , the coating amount is 5 g / m ^2. With the above, it is possible to ensure the ease of handling during bonding (stability of behavior during bonding process such as lamination, heating, pressurization, cooling, etc., so-called handleability), and the amount of grain. When the amount is 30 g / m ² or less, the thickness of the third nonwoven fabric 16 in the thickness direction can be reduced to achieve a thinner filter medium 10.

Further, according to the method for manufacturing a filter filter medium according to the embodiment, since the third nonwoven fabric 16 is an electretized melt-blown nonwoven fabric, it is possible to obtain high collection performance due to electrostatic force.

Further, according to the method for manufacturing a filter filter medium according to the embodiment, in the nanofiber laminating step S1, the nanofibers are laminated by using the multi-nozzle type electrospinning apparatus 200 in which the spinning direction is from bottom to top. It is possible to stack uniformly and efficiently.

Further, according to the method for producing a filter filter medium according to the embodiment, in the bonding step S2, the third non-woven fabric 16 is bonded by hot melt using the resin adhesive 18, so that the third non-woven fabric is an electletized melt-blown non-woven fabric. 16 can be stably adhered.

Further, according to the method for producing a filter filter medium according to the embodiment, since the third nonwoven fabric 16 is made of polypropylene as a raw material, the collection performance of the filter filter medium 10 is deteriorated over time by suppressing the attenuation of the effect of electretization. It is possible to suppress deterioration.

Further, according to the method for producing a filter filter medium according to the embodiment, in the nanofiber laminating step S1, nanofibers made from at least one of thermoplastic polyurethane, polyvinylidene fluoride, polyamide, polyacrylonitrile and polyvinyl alcohol are used. Since the two non-woven fabric 14 is formed, it is possible to stably form the second non-woven fabric 14 having high collection performance.

Further, according to the method for producing a filter filter medium according to the embodiment, since the third nonwoven fabric 16 has a uniform structure throughout, the third nonwoven fabric 16 having less unevenness in thickness and density is used. The non-woven fabric 16 can be uniformly adhered to the surface of the second non-woven fabric 14, and as a result, deterioration and breakage (particularly, deterioration and breakage when the fluid flow direction is not constant) are less likely to occur in the filter filter medium. Can be manufactured.

Further, according to the method for manufacturing a filter filter medium according to the embodiment, since the third non-woven fabric 16 has a uniform structure throughout, the internal space of the filter filter medium 10 (a space that is not inside any of the non-woven fabrics) is used. As a result, it becomes possible to manufacture a filter filter medium having high shape stability and backwash performance.

According to the filter filter medium 10 according to the embodiment, by combining a non-woven fabric made of ordinary fibers and a nanofiber non-woven fabric, it is possible to achieve thinning and weight reduction while maintaining high collection performance.

Further, according to the filter filter medium 10 according to the embodiment, the second non-woven fabric 14 is integrated on one side of the first non-woven fabric 12, which is a spunbonded non-woven fabric that is relatively hard to be charged, by contact and entanglement between the fibers constituting the respective non-woven fabrics. Therefore, it is possible to reduce the electrical repulsion generated between the first non-woven fabric 12 and the nanofibers at the time of manufacturing, and to firmly integrate the second non-woven fabric 14 and the first non-woven fabric 12. As a result, the filter filter medium 10 according to the embodiment becomes a filter filter medium that is less likely to be deteriorated or damaged than the filter filter medium manufactured by the conventional method for manufacturing a filter filter medium.

Therefore, the filter filter medium 10 according to the embodiment can be made thinner and lighter while maintaining high collection performance, and is deteriorated or damaged as compared with the filter filter medium manufactured by the conventional method for manufacturing the filter filter medium. It becomes a difficult filter filter medium.

Further, according to the filter filter medium 10 according to the embodiment, since the second non-woven fabric 14 is integrated on one side of the first non-woven fabric 12, which is a spunbonded non-woven fabric that is relatively hard to be charged, the nanofibers are appropriately laminated at the time of manufacture. It is possible to improve the collection performance per thickness as a high-quality nanofiber non-woven fabric. As a result, according to the filter filter medium 10 according to the embodiment, it is possible to secure high collection performance even as a filter filter medium thinner than the conventional filter filter medium.

Further, according to the filter filter medium 10 according to the embodiment, since the third nonwoven fabric 16 has a uniform structure throughout, the third nonwoven fabric 16 is seconded by using the third nonwoven fabric 16 having less unevenness in thickness and density. It is possible to uniformly adhere to the surface of the non-woven fabric 14 to increase the adhesive strength, and as a result, deterioration and breakage (particularly deterioration and breakage when the fluid flow direction is not constant) are less likely to occur. It becomes possible.

Further, according to the filter filter medium 10 according to the embodiment, since the third nonwoven fabric 16 has a uniform structure throughout, it is possible to reduce the internal space of the filter filter medium 10, and as a result, the shape stability and the reverse It is possible to improve the washing performance.

Further, according to the filter filter medium 10 according to the embodiment, when the N95 standard is satisfied, it is particularly suitable for use in a particularly severe environment such as a dust-generating work site, an operating room, a ward, or a pandemic countermeasure site. It can be used as a filter filter medium for use in a respirator.

Further, according to the filter filter medium 10 according to the embodiment, the test particles of JIS8 type are deposited on the first non-woven fabric 12 side while sucking air, and the pressure loss is 1.5 of the pressure loss before the test particles are deposited. After doubling, the pressure loss after sending exhaled air with an average surface wind velocity of 26 cm / s from the third non-woven fabric 16 side 5 times for 1 second each is 1.1 times the pressure loss before depositing the test particles. Since the following, it is possible for an adult to perform sufficient backwashing by sending a strong exhalation.

Since the respirator 100 according to the embodiment uses the filter filter medium provided with the filter filter medium 10 according to the embodiment, both high collection performance and reduction of the load on the wearer are achieved, and the conventional filter filter medium is used as a filter. It is a respirator that is less likely to deteriorate or break the filter than the respirator used as a component.

Further, according to the respirator 100 according to the embodiment, the overall thickness of the filter 20 is in the range of 0.2 mm to 1.5 mm, so that the filter 20 is sufficiently strong while sufficiently ensuring the strength of the filter 20. It is possible to achieve a thin and light weight.

Further, according to the respirator 100 according to the embodiment, since the surface shape of the filter 20 is plain, it is possible to prevent the collection performance from being deteriorated due to the formation of embossing or the like.

Further, according to the respirator according to the embodiment, since the third nonwoven fabric 16 has a uniform structure throughout, the third nonwoven fabric 16 can be changed to the second nonwoven fabric 14 by using the third nonwoven fabric 16 having less unevenness in thickness and density. It is possible to uniformly adhere to the surface of the non-woven fabric to increase the adhesive strength, and as a result, it is possible to prevent deterioration and breakage (particularly deterioration and breakage when the fluid flow direction is not constant). It will be possible.

Further, according to the respirator according to the embodiment, since the third nonwoven fabric 16 has a uniform structure throughout, the internal space of the filter filter medium 10 can be reduced, and the shape stability and the backwash performance are improved. It becomes possible.

Further, according to the respirator 100 according to the embodiment, since the mouth-side non-woven fabric 22 made of the thermal-bonded non-woven fabric is provided as a component of the filter 20, it is possible to prevent the mouth from directly touching the filter filter medium 10, and the filter filter medium 10 can be prevented from coming into direct contact with the filter medium 10. Can be prevented from being damaged.

Further, according to the respirator 100 according to the embodiment, since the filter filter medium 10 and the non-woven fabric 22 on the mouth side are joined at the respective ends, the filter medium 10 is pulled by the movement of the non-woven fabric 22 on the mouth side, and the filter medium is filtered. It is possible to prevent an excessive load from being applied to the 10.

Further, according to the respirator 100 according to the embodiment, when the N95 standard is satisfied, the respirator is particularly suitable for use in a particularly severe environment such as a dust-generating work site, an operating room, a ward, or a pandemic countermeasure site. It becomes possible to.

Further, according to the respirator 100 according to the embodiment, the test particles of JIS8 type are deposited on the first non-woven fabric 12 side while sucking air, and the pressure loss is 1.5 times the pressure loss before the test particles are deposited. After that, the pressure loss after sending exhaled air with an average surface wind velocity of 26 cm / s 5 times for 1 second from the 3rd non-woven fabric 16 side is 1.1 times or less of the pressure loss before depositing the test particles. Therefore, it is possible for an adult to perform sufficient backwashing by sending a strong exhalation.

[Example]
Hereinafter, the effects of the filter filter medium and the respirator (filter) of the present invention will be described based on actual experiments.
FIG. 6 is a table showing the experimental results of Examples and Comparative Examples.

In the examples, the filter filter medium within the scope of the present invention and the filter used for the respirator within the scope of the present invention were actually manufactured and compared with the filters of commercially available respirators and masks.
Hereinafter, Examples 1 and 2 and Comparative Examples 1 and 2 used in the experiment will be described.

Example 1 is a filter filter medium within the scope of the present invention. The filter filter medium has the same configuration as the filter filter medium 10 according to the above embodiment, and is manufactured by the same method as the method for producing the filter filter medium according to the above embodiment.
The first non-woven fabric in Example 1 is a spunbonded non-woven fabric made of polypropylene (PP) having a basis weight of 30 g / m ² and an average thickness of 0.15 mm.
The second non-woven fabric in Example 1 is ^{a nanofiber non-woven fabric made of thermoplastic polyurethane (TPU) having a grain size of 0.1 g / m 2} and an average thickness of 0.0003 mm (300 nm).
The third non-woven fabric in Example 1 is a melt-blown non-woven fabric made of polypropylene (PP) having a basis weight of 26 g / m ^{2 and a thickness of 0.19 mm.}

Example 2 is a filter used for a respirator within the scope of the present invention. The respirator and the filter have the same configuration as the respirator 100 and the filter 20 according to the above embodiment.
The filter in Example 2 is a laminate of the filter filter medium according to Example 1 described above and a thermal-bonded non-woven fabric for the mouth.
As the thermal bond non-woven fabric, a non-woven fabric made of polypropylene and polyethylene having a basis weight of 15 g / m ² and an average thickness of 0.9 mm was used.

Comparative Examples 1 and 2 are actually commercially available respirator or mask filters.
The filter in Comparative Example 1 is a stack of two melt-blown non-woven fabrics made of polypropylene (PP). Comparative Example 1 is a filter used in a commercially available N95 mask (respirator).
The filter in Comparative Example 2 is a spunbonded non-woven fabric made of polypropylene (PP) (grain: 30 g / m ² , average thickness: 0.15 mm) and a thermoplastic polyurethane (TPU) having a grain of 0.1 g / m. ^Two nanofiber non-woven fabrics are laminated, and two nanofiber non-woven fabrics are laminated so that the nanofiber non-woven fabric is on the inside. Comparative Example 2 is a filter used for a lightweight mask using nanofibers.

The thickness of the filter medium and the filter was measured with a thickness gauge.
The basis weight was calculated by actually measuring the weight of the filter medium or the filter cut out so as to have a predetermined area.

The experiments in the examples were carried out according to the N95 standard for the filter media and the filter of each respirator.
The N95 standard is one of the standards set by the US NIOSH (National Institute for Occupational Safety and Health), where "N" indicates that there is no oil resistance, and "95" captures 95% or more of test particles. Indicates that you can collect. In order to meet this standard, test particles with an aerodynamic mass diameter of approximately 0.3 μm, which is the most difficult to collect with a filter, must be used and have a collection performance capable of collecting 95% or more of the test particles. .. The N95 standard is a standard related to filter performance, and does not guarantee the performance when used as a respirator.

In the experiment in the experimental example, NaCl (average particle diameter 0.075 μm ± 0.02 μm) was used as the test particles, the gas flow rate was 85 L ± 2 L / min, and the pretreatment conditions were 38 ° C./humidity 85% / 24 h ± 1 h. And said.

The collection performance was evaluated based on the collection efficiency, and it was confirmed whether or not the collection efficiency was 95% or more at the initial stage and after exposure (when 200 mg of NaCl was deposited).
Collection efficiency was measured using TSI-8130 from TSI Inc. of the United States. The number of trials was 4, and the average value of the obtained results was treated as the final collection efficiency.

For the pressure loss, the initial value was confirmed.
The pressure loss was also measured using TSI-8130 of TSI Inc. of the United States. The number of trials was 4, and the average value of the obtained results was treated as the final collection efficiency.

The experimental results are shown in FIG.
As a result of the experiment, it was confirmed that the filter filter medium according to Example 1 exhibited excellent performance that sufficiently satisfied the N95 standard or more in terms of collection performance and pressure loss.
Next, looking at the comparative example, it can be seen that the filter according to the comparative example 1 has sufficient collection performance as a filter used for the N95 mask. Further, the filter according to Comparative Example 2 is thin and has an extremely small pressure loss, but it can be seen that the collection performance is insufficient when viewed by the standard of the N95 mask.
On the other hand, with respect to the filter according to Example 2, it was confirmed that the pressure loss was the same value while exceeding the collection performance as compared with the filter filter medium according to Example 1.
Further, the filter according to the second embodiment has a thickness of about two-thirds as compared with the filter according to the comparative example 1, and the pressure loss is also small, but the collection performance is the same as that of the comparative example 1. It was confirmed that it was higher than the above filter.
Further, the filter according to Example 2 is a filter using nanofibers like the filter according to Comparative Example 2, but has a larger collection capacity that can be expected from the difference in thickness as compared with the filter according to Comparative Example 2. It was confirmed that it has a collecting ability that exceeds that.

When a respirator was actually produced using the above filter, a respirator (N95 mask) having a filter thickness of 1.2 mm and a product weight of 4.6 g could be produced while maintaining the above collection performance. It was. Since the filter thickness of a general respirator (which satisfies the N95 standard) is about 1.5 mm to 4 mm and the product weight is about 5 g to more than 10 g, the respirator according to the present invention is a general respirator. In comparison, it was also confirmed that they were excellent in terms of thickness and weight while having the same or excellent performance. The thin thickness contributes to space saving, and is a great advantage especially when storing (storing) or transporting. In addition, the light weight has the effect of reducing the load on the user, and it is also possible to transport more respirators within a limited weight limit during transportation. means.

[Additional Example 1]
As an additional example 1, an experiment was conducted for investigating the backwashing performance (regeneration performance) of the respirator of the present invention.
FIG. 7 is a schematic view showing the configuration of the experimental device 400 used in the experiment in the additional embodiment 1.
FIG. 8 is a graph showing the results of the experiment in Additional Example 1.

The filter filter medium used in the experiment in Additional Example 1 is the same as the filter filter medium of Example 1 in the above Example, and the respirator is the same as the respirator of Example 2 in the above Example.

The experiment in Additional Example 1 is a test (cycle test) in which test particles (dust) are continuously sucked and released in order to evaluate the backwashing performance of the filter filter medium and the respirator of the present invention.

The experimental apparatus 400 used in the experiment includes a sample setting unit 410, an air flow unit 420, a differential pressure gauge 430, a flow meter 440, and a blower 450 (see FIG. 7).
The sample mounting portion 410 has a substantially cylindrical shape, and has a sample mounting port 412 for mounting the sample at one end. The sample setting section 410 is configured to be removable from the air flow section 420 of the experimental device 400.
The diameter of the sample mounting port 412 was 7 cm. Therefore, the test area is about 38.5 cm ² .

As the differential pressure gauge, a differential pressure gauge DMC-103N manufactured by Okano Seisakusho Co., Ltd. was used.
As the flow meter, a gas mass flow meter CMS0050BSRN manufactured by Azbil Corporation was used.

Hereinafter, the experiment in Additional Example 1 will be described.
First, the central portion of the respirator was cut off to prepare a sample composed of a filter medium and a non-woven fabric on the mouth side (hereinafter referred to as sample S). Subsequently, the sample S was attached to the sample attachment port 412 with the outside (first non-woven fabric side) of the respirator as the outside and the mouth side non-woven fabric side as the inside (step 1).

Next, air was sucked by the blower 450 until the rated air volume was reached, and the initial pressure loss (differential pressure) was measured by the differential pressure gauge 430. The rated air volume was 85 L / min (step 2).

Next, the test particles were deposited on the surface of the sample S while maintaining the rated air volume. JIS8 type was used as the test particle. The deposition concentration of the test particles was 1 g / m ³ , and the deposition pace was 0.085 g / min (step 3).

The test particles were continuously deposited, and the blower 450 was stopped when the pressure loss became about 1.5 times the initial pressure loss (step 4).

After that, the sample setting unit 410 was removed from the experimental device 400, and an adult male sent a strong exhalation 5 times for about 1 second from the side opposite to the sample mounting port 412. In this way, backwashing was performed to separate the test particles from the surface of the sample S, and an attempt was made to regenerate the filtration capacity of the sample S (step 5).
The "strong exhalation" refers to the exhalation when a larger amount of air than the amount of air discharged by normal respiration is discharged in a short time. A strong exhalation can also be expressed as having a duration of about 1 second and an average surface wind speed of about 26 cm / s.

Next, the sample setting unit 410 was reattached to the experimental device 400, air was sucked by the blower 450 until the rated air volume was reached, the pressure loss was measured by the differential pressure gauge 430, and the pressure loss was compared with the initial pressure loss (step). 6).

Then, step 2 to step 6 were repeated once again with the pressure loss after the test as the initial pressure loss. That is, the same sample was tested twice.

The results of the test are shown in FIG.
The initial pressure loss in the first test was 147 Pa.
The initial pressure loss in the second test was 150 Pa. As shown in the graph of FIG. 8, the initial pressure loss in the second test is the same as the pressure loss after backwashing (regeneration) in the first test.
The difference between the value of the initial pressure loss (see FIG. 6) in the example and the value of the initial pressure loss in the additional example 1 is due to the difference in the experimental conditions (particularly, the difference in the test area).

In the first test, the blower 450 was stopped when the pressure loss reached 227 Pa.
In the second test, the blower 450 was stopped when the pressure loss reached 230 Pa.
In the first test, the pressure loss after backwashing (regeneration) was 150 Pa.
In the second test, the pressure loss after backwashing was 155 Pa.

As described above, it was confirmed that the sample S can restore the pressure loss to almost the initial pressure loss by releasing the test particles by exhalation. Specifically, "The test particles of JIS8 type are deposited on the first non-woven fabric side while sucking air, and the pressure loss becomes 1.5 times the pressure loss before the test particles are deposited, and then the third The pressure loss after sending exhaled air having an average surface wind velocity of 26 cm / s from the non-woven fabric side five times for each second is 1.1 times or less of the pressure loss before depositing the test particles, and more specifically, 1 It was confirmed that it was 0.05 times or less. "
This indicates that it is easy to regenerate and has high backwash performance.

In the above test, it is considered that the mouth non-woven fabric in Sample S does not function as a filter. Therefore, even in the filter filter medium, "test particles of JIS8 type are deposited on the first non-woven fabric side while sucking air. After the pressure loss became 1.5 times the pressure loss before depositing the test particles, the pressure loss after sending exhaled air with an average surface wind velocity of 26 cm / s 5 times per second from the third non-woven fabric side. However, it is considered that "the pressure loss before depositing the test particles is 1.1 times or less, more specifically, 1.05 times or less" is established.

[Additional Example 2]
As an additional example 2, an experiment was conducted in which the state after sucking the test particles was observed.
FIG. 9 is an SEM image showing the state of each respirator after suction of test particles in Additional Example 2. FIG. 9A is an SEM image of the respirator A, which is the same respirator as the respirator in Example 2, FIG. 9B is an SEM image of the respirator B for comparison, and FIG. 9C is a comparison. It is an SEM image about the respirator C for.

First, a respirator A, a respirator B for comparison, and a respirator C for comparison, which are the same respirators as the respirator in Example 2 above, were prepared.
The respirators B and C were respirators in which the filter portion was made of melt-blown non-woven fabric.
Respirators B and C are commercially available N95 standard respirators.
The product thickness of the respirator B was 1.6 mm, and the product weight was 7.0 g. The product thickness of the respirator C was 4.0 mm, and the product weight was 10.8 g.

First, the above three respirators were set at one end of a cylinder having a diameter of 100 mm.
Next, 1 g of test particles was placed on the surface of the respirator (on the side of the first non-woven fabric in the respirator A), and air was sucked from the other end of the cylinder for 10 seconds. As test particles (dust), volcanic ash from Sakurajima was used. The air was sucked by a blower, and the air volume was 85 L / min.
Then, after the test particles were wiped off and the respirator was attached by an adult male, strong exhalation was sent 5 times from the side opposite to the side on which the test particles were placed.
For each respirator in this state, the collection state of the test powder in the filter portion was confirmed using SEM.
As the SEM, a 3D real surface view microscope VE-9800 manufactured by KEYENCE CORPORATION was used.

As a result, it was confirmed that in the respirator A, the test particles were collected on the surface of the second non-woven fabric (nanofiber, a portion having dense eyes near the center of the image in FIG. 9A). On the other hand, in the respirator B and the respirator C, it was confirmed that the test particles had entered the entire filter (see FIG. 9).
Therefore, it can be said that the respirator A is easy to backwash, while the respirator B and the respirator C are difficult to backwash.

In a filter filter medium having a first non-woven fabric which is a spunbonded non-woven fabric, a second non-woven fabric which is a nanofiber non-woven fabric, and a third non-woven fabric which is an electletized melt-blown non-woven fabric, powder or the like is adsorbed on the third non-woven fabric side. If this is the case, it is considered that the third non-woven fabric strongly adsorbs particles and the like, making backwashing difficult.

Although the present invention has been described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment. It can be carried out in various aspects within a range that does not deviate from the purpose, and for example, the following modifications are also possible.

(1) The shapes, numbers, positions, etc. of the components described in the above embodiments are examples, and can be changed as long as the effects of the present invention are not impaired.

(2) The method for producing a filter filter medium described in the above embodiment is an example, and for example, steps other than those described above may be further included.

(3) The respirator 100 described in the above embodiment is an example, and for example, the folding method may be different, or a non-folding type such as a cup-shaped one may be used.

(4) The filter filter medium of the present invention may be used for applications other than respirators (for example, filters for devices that allow fluid to pass through).

The filter filter medium and respirator according to the present invention have high collection efficiency of liquids, harmful particles, viruses, etc., and have high air permeability and excellent usability. Therefore, hospitals, schools, stores, office buildings, factories, trains, buses, etc. , Can be suitably used for various purposes including aircraft.

10 ... Filter filter medium, 12 ... 1st non-woven fabric, 14 ... 2nd non-woven fabric, 16 ... 3rd non-woven fabric, 18 ... Resin adhesive, 20 ... Filter, 22 ... Mouth side non-woven fabric, 30 ... Binding tape, 40 ... Cover tape, 50 ... Nose clamp, 60 ... Rubber for mounting, 100 ... Respirator, 200 ... Multi-nozzle type electrospinning device, 210, 320, 322 ... Feeding roll, 212, 324 ... Winding roll, 300 ... Resin adhesive coating machine, 310 ... Heating heater, 400 ... Experimental device, 410 ... Sample installation unit, 412 ... Sample mounting port, 420 ... Air flow unit, 430 ... Differential pressure gauge, 440 ... Flow meter, S ... Sample

Claims (14)

On one side of the first nonwoven basis weight is spunbond nonwoven fabric in the range of ^{10g / m 2 ~50g / m 2} , the basis weight of the nanofiber average fiber diameter is within the range of 100nm~400nm is 0.05g A nanofiber laminating step of laminating so as to be within the range of / m ^{2 to} 0.2 g / m ^{2 to form a second non-woven fabric, and}
Bonding the first nonwoven fabric on the surface of the second nonwoven fabric opposite, weight per unit area to adhere the third nonwoven is electret meltblown nonwoven is in the range of 5g / m ² ~30g / m ² Including the steps in this order,
A method for producing a filter filter medium, wherein the total thickness of the first non-woven fabric, the second non-woven fabric, and the third non-woven fabric is in the range of 0.05 mm to 0.4 mm. The method for producing a filter filter medium according to claim 1, wherein the third nonwoven fabric has a uniform structure throughout. A first nonwoven basis weight is spunbond nonwoven fabric in the range of ^{10g / m 2 ~50g / m 2} ,
The first is located on one side of the nonwoven fabric, nanofiber nonwoven fabric basis weight consists nanofibers average fiber diameter is within the range of 100nm~400nm is in the range of 0.05g ^{/ m 2} ~0.2g ^/ m 2 The second non-woven fabric, which is
Wherein the second nonwoven said first nonwoven is arranged on the opposite side, and a third nonwoven basis weight is electret meltblown nonwoven is in the range of 5g / m ² ~30g / m ² Have and
The first non-woven fabric and the second non-woven fabric are integrated by contact and entanglement of fibers constituting each non-woven fabric.
A filter filter medium having a thickness in the range of 0.05 mm to 0.4 mm. The filter filter medium according to claim 3, wherein the third nonwoven fabric has a uniform structure throughout. The filter filter medium according to claim 3 or 4, wherein the filter filter medium satisfies the N95 standard. While sucking air, test particles of JIS8 type are deposited on the first non-woven fabric side, and the pressure loss becomes 1.5 times the pressure loss before the test particles are deposited, and then from the third non-woven fabric side. 3. The third aspect of the present invention is that the pressure loss after sending exhaled air having an average surface wind velocity of 26 cm / s five times for each second is 1.1 times or less the pressure loss before depositing the test particles. The filter filter medium according to any one of ~ 5. A first nonwoven basis weight spunbond nonwoven fabric in the range of ^{10g / m 2 ~50g / m 2} , is disposed on one side of the first nonwoven fabric, nano average fiber diameter is within the range of 100nm~400nm The second non-woven fabric, which is a nanofiber non-woven fabric composed of fibers and has a grain size in the range of 0.05 g / m ^{2 to} 0.2 g / m ² , and the second non-woven fabric are arranged on opposite sides of the first non-woven fabric. It has a third non-woven fabric which is an electretized melt-blown non-woven fabric having a textured amount in the range of 5 g / m ^{2 to} 30 g / m ^{2, and the first non-woven fabric and the second non-woven fabric are respectively.} A respirator characterized in that a filter filter medium having a thickness in the range of 0.05 mm to 0.4 mm, which is integrated by contact and entanglement of fibers constituting the non-woven fabric, is provided as a component of the filter. The respirator according to claim 7, wherein the total thickness of the filter is in the range of 0.2 mm to 1.5 mm. The respirator according to claim 7 or 8, wherein the filter has a plain surface shape. The respirator according to any one of claims 7 to 9, wherein the third nonwoven fabric has a uniform structure throughout. The respirator according to any one of claims 7 to 10, wherein the mouth-side non-woven fabric made of a thermal-bonded non-woven fabric is included as a component of the filter. The respirator according to claim 11, wherein the filter media and the non-woven fabric on the mouth side are joined at their respective ends. The respirator according to any one of claims 7 to 12, wherein the respirator satisfies the N95 standard. While sucking air, test particles of JIS8 type are deposited on the first non-woven fabric side, and the pressure loss becomes 1.5 times the pressure loss before the test particles are deposited, and then from the third non-woven fabric side. 7. The pressure loss after sending exhaled air having an average surface wind velocity of 26 cm / s five times for each second is 1.1 times or less the pressure loss before depositing the test particles. The respirator according to any one of ~ 13.

Images