JP2002030553A - Moisture-absorbing and releasing non-woven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture-absorbing and releasing non-woven fabric which has excellent moisture-absorbing and releasing characteristics, excellent antibacterial and antifungal actions, and a high strength, is approximately free from lint, scarcely drops moisture-absorbing and releasing fine particles, sufficiently resists to repeated employments, and has a good touch. SOLUTION: This moisture-absorbing and releasing non woven fabric, characterized by containing 2 to 100 pts.wt. of moisture-absorbing and releasing fine particles having an antibacterial and/or antifungal action in 100 pts.wt. of a non-woven fabric comprising fibers having a fineness of 0.3 to 10 dtex, having an air permeability of >=5 cc/cm2/sec, and satisfying the following requirements: 10<=a<=100, 2<=b<=80, and 6<=(a-b)<=98, wherein (a: wt.%) is a coefficient of moisture absorption after equilibrium moisture absorption at 20 deg.C and 90% RH, and (b: wt.%) is a coefficient of moisture absorption after equilibrium moisture absorption at 20 deg.C and 45% RH.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an excellent antibacterial and / or antifungal effect without providing an antibacterial agent and / or an antifungal agent. It is a moisture-absorbing and non-woven fabric which has high strength, is almost lint-free (has no dust generation), and has a good texture that has a small amount of moisture-absorbing and desorbing fine particles and can withstand repeated use. is there. This nonwoven fabric can be suitably used, for example, for insole applications by utilizing the above functions.

[0002]

2. Description of the Related Art Conventionally, as materials for various living materials, sanitary materials, or industrial materials, nonwoven fabrics made of a thermoplastic resin having a fiber-forming ability, such as polyester or polyolefin, have been used. However, nonwoven fabrics made of these materials generally have poor hygroscopicity, and as a means of imparting hygroscopicity, a method of gripping the nonwoven fabric with a hygroscopic agent such as lithium chloride, calcium chloride, magnesium chloride, and phosphorus pentoxide has been adopted. I have. These hygroscopic agents have a large amount of hygroscopicity and a high hygroscopic rate. However, since they are deliquescent, they have a drawback such as liquefaction after absorbing moisture to contaminate other substances and make regeneration difficult. On the other hand, hygroscopic agents such as silica gel, zeolite, sodium sulfate, activated alumina, and activated carbon have disadvantages in that they have a small amount of moisture absorption, have a low moisture absorption rate, and require high temperatures for regeneration.

Japanese Unexamined Patent Application Publication No. 11-181662 discloses a moisture-absorbing and desorbing long-fiber nonwoven fabric. In order to increase the moisture-absorbing and desorbing speed, it is necessary to reduce the fiber diameter or to use a modified cross section. It is necessary to increase the surface area of the fiber, thereby lowering productivity and spinnability, and increasing the production cost.

On the other hand, nonwoven fabrics having hygroscopicity are obtained by mechanically entanglement and integration of natural fibers such as cotton, hemp and silk, or regenerated fibers such as rayon and polynosic.
So-called needle-punched nonwoven fabrics and water-punched nonwoven fabrics are known. But these types of nonwovens
In general, there are drawbacks in that the fibers are composed of short fibers and have low strength and high dusting properties. In addition, since the fibers themselves are not thermoplastic, a special processing method must be employed to form a nonwoven fabric.

For imparting antibacterial and antifungal properties, a method of supporting a metal-based antibacterial agent and an antifungal agent on a nonwoven fabric is adopted. However, there are many methods such as safety to human body, lapse due to oxidation, and discoloration. The problem has been pointed out.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to have excellent moisture absorption / desorption characteristics and to achieve high humidity control. It has a function, furthermore, exhibits excellent antibacterial and / or fungicidal action even without adding a specific antibacterial agent or fungicide, and is highly powerful and lint-free, and is capable of removing moisture-absorbing and releasing fine particles. It is an object of the present invention to provide a moisture-absorbing and desorbing nonwoven fabric which has a small amount, can withstand repeated use, and has a good texture.

[0007]

The moisture-absorbing and desorbing nonwoven fabric according to the present invention, which has achieved the above-mentioned objects, has a fineness of 0.1%.
2 to 100 parts by mass of hygroscopic fine particles having an antibacterial action and / or an antifungal action are contained in 100 parts by mass of a nonwoven fabric made of 3 to 10 dtex fibers, and 20 ° C., 90% R
H after the equilibrium moisture absorption in H (a: mass%)
The gist is that the moisture absorption rate (b: mass%) after equilibrium moisture absorption at 45 ° C. and 45% RH satisfies the following requirements. 10 ≦ a ≦ 100, 2 ≦ b ≦ 80, 6 ≦ (ab) ≦ 9
8

[0008] In the moisture-absorbing and releasing nonwoven fabric according to the present invention, the tensile strength per unit weight is 1.0 N / 5 cm / (g / m ² ) or more in the machine direction and the transverse direction. Is preferably 5 cc / cm ² / sec or more, and the moisture absorption time (t ₁ ) from the equilibrium moisture absorption state at 20 ° C. and 45% RH to the equilibrium moisture absorption state at 20 ° C. and 90% RH is 60. Minutes and 20 minutes from the equilibrium moisture absorption state at 20 ° C. and 90% RH.
It is preferable that the moisture release time (t ₂ ) until the state of equilibrium moisture absorption at 45 ° C. and 45% RH is 60 minutes or less.

As the moisture absorbing / releasing fine particles, acrylonitrile polymer fine particles are recommended as preferable.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the fineness of the moisture-absorbing / desorbing nonwoven fabric according to the present invention must be in the range of 0.3 to 10 dtex. If the fineness is less than 0.3 dtex, not only the desired strength of the nonwoven fabric cannot be obtained, but also the air permeability becomes poor, and the moisture absorption / release rate becomes slow. But fineness is 10dtex
If it exceeds, not only is it difficult to contain the desired moisture-absorbing and desorbing fine particles, but also the fine particles easily fall off, which is not preferable.

The non-woven fabric carrying the fine particles may be either a short-fiber non-woven fabric or a long-fiber non-woven fabric, but a long-fiber non-woven fabric is preferred from the viewpoint of mechanical properties and dust generation. In addition, the production method is not particularly limited, but preferred methods include, for example, a carding method and an air-lay method for a short-fiber nonwoven fabric, and a spunbond method and a melt-blow method for a long-fiber nonwoven fabric. Is exemplified.
Further, post-processing such as needle punching, water punching, and calendaring may be performed.

The fibers constituting the non-woven fabric are preferably synthetic fibers made of a thermoplastic resin. However, if necessary, natural fibers, recycled fibers, semi-synthetic fibers, inorganic fibers and the like may be mixed or mixed. I do not care. Also, synthetic fibers are not particularly limited as long as they have a fiber-forming ability. For example, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate,
Polyesters such as low-melting polyesters copolymerized with isophthalic acid; polypropylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and propylene and other α-olefins.
Polyolefins such as terpolymers; polyamides such as nylon 6 and nylon 66; or mixtures or copolymers thereof. In addition, there is no reason to be limited to a single-component synthetic fiber, and a multi-component type such as a core-in-sheath type, an eccentric core-in-sheath type, a side-by-side type, a sea-island type,
There is no particular limitation on the shape of the fiber cross section. If necessary, various additives such as a matting agent, a pigment, an antioxidant, an ultraviolet absorber, a light stabilizer, a crystal nucleating agent, a flame retardant, and an anti-mite agent may be used in combination.

Acrylonitrile polymer fine particles are particularly preferably used as the moisture absorbing and releasing fine particles of the present invention, and crosslinked acrylonitrile polymer fine particles are more preferable. For example, crosslinked acrylonitrile-based polymer fine particles whose nitrogen content is increased by 1 to 15% by mass by hydrazine crosslink, and 1 mm of residual nitrile groups
Moisture-absorbing and desorbing fine particles having 1 / g or more converted to salt-type carboxyl groups are recommended as particularly preferable. Such moisture-absorbing and desorbing fine particles are commercially available from Nippon Xlan Industrial Co., Ltd. as "Hygroscopic and desorbing fine particles: HU series".

The particle size of the moisture-absorbing and desorbing fine particles is not particularly limited, and may be appropriately selected and determined according to the application. For example, when it is desired to increase the moisture absorption rate, the surface area of the particles is increased. It is preferable to use particles having a particle diameter of 10 μm or less, more preferably 1 μm or less.

The content of the hygroscopic fine particles in the nonwoven fabric must be in the range of 2 to 100 parts by mass with respect to 100 parts by mass of the nonwoven fabric. If the amount is less than 2 parts by mass, it is difficult to obtain a satisfactory effect because the moisture absorption characteristics and the moisture release characteristics are too low.
Swelling of the moisture-absorbing / desorbing fine particles deteriorates air permeability, and as a result, not only the moisture-absorbing / desorbing speed is reduced, but also a problem that tackiness appears on the surface of the nonwoven fabric arises.

The method for incorporating the moisture-absorbing and desorbing fine particles into the nonwoven fabric is not particularly limited, but a preferable method is, for example, adding a binder resin to an emulsion of the moisture-absorbing and desorbing fine particles, and impregnating or spraying. Examples include a chemical bonding process applied by a printing method, a foam impregnation method, or the like. Further, a method of performing a graft polymerization process together with a monomer component capable of radical polymerization, specifically, a processing liquid containing moisture-absorbing / desorbing fine particles, a radical-polymerizable monomer, and a radical polymerization catalyst in water or water and a soluble solvent. , A method of applying heat treatment to a nonwoven fabric, and the like.

The type of the binder resin is not particularly limited, and for example, a synthetic resin type or rubber type can be used.
Examples of the synthetic resin binder include polyacrylate, acrylonitrile-styrene copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, vinyl acetate and acrylic monomer. Copolymers with polyethylene, polyethylene, polyvinyl chloride, ethylene-vinyl chloride copolymer, polyvinylidene chloride, polystyrene, polyurethane, polyester, epoxy, and the like. Select and use.

Examples of the rubber-based binder include natural rubber, polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, butadiene-methyl methacrylate copolymer, butadiene-styrene-vinylpyridine copolymer, and chloroprene. , Polyisoprene, etc., and these may be appropriately selected and used in the same manner as described above for the nonwoven fabric to be used.

Furthermore, if necessary, amino-based (melamine resin, urea resin, etc.), epoxy-based, aziridine-based, isocyanate-based crosslinking agents and softeners, water / oil repellents, flame retardants, pigments, migration inhibitors, Thickeners, defoamers, penetrants, anti-mite agents, deodorants / deodorants, sanitary agents and the like may be used in combination as long as the effects of the present invention are not impaired.

The moisture-absorbing and releasing nonwoven fabric of the present invention is JIS L
The tensile strength per unit weight in the tensile test specified in 1906 is 1.0 N / 5 cm /
(G / m ² ) or more. 1.0N / 5
If it is less than cm / (g / m ² ), not only is the shape retention of the moisture-absorbing / desorbing nonwoven fabric deteriorated, but also the process passability is undesirably deteriorated. Further, in applications requiring high strength, the use itself may be difficult.

The moisture absorbing / releasing nonwoven fabric of the present invention has a
% RH after equilibrium moisture absorption (a: mass%) is “10 ≦ a ≦ 100”, and the moisture absorption rate after equilibrium moisture absorption (b: mass%) at 20 ° C. and 45% RH is “2 ≦ b”. ≦ 8
0 ”and the relationship between a and b is“ 6 ≦
(A−b) ≦ 98 ”is extremely important for achieving the object. When the amount is out of any of the above ranges, not only the problem that the amount of moisture absorption tends to be insufficient or the film tends to be tacky is easily caused, but also it is difficult to effectively exhibit antibacterial properties and antifungal properties.

The above "10≤a≤100", "2≤b≤8"
0 ”and“ 6 ≦ (ab) ≦ 98 ”, as a specific means, regardless of the basis weight of the nonwoven fabric as the base material, the moisture-absorbing and desorbing fine particles are added to the base nonwoven fabric at 10 g / m 2. It is desirable to contain about ² or more, more preferably about 15 g / m ² or more.

The air permeability of the moisture-absorbing and releasing nonwoven fabric according to the present invention is as follows:
It is preferably at least 5 cc / cm ² / sec, more preferably at least 10 cc / cm ² / sec. 5
When the flow rate is less than cc / cm ² / sec, the flow of air becomes poor, and as a result, the rate of moisture absorption and desorption is undesirably reduced. As a specific means for satisfying the air permeability, for example, avoid heat pressure welding so that the surface of the substrate non-woven fabric is formed into a film, the content of the moisture-absorbing and releasing fine particles is suppressed to about 100 parts by mass or less, or , Fineness is 0.3dtex
When using a base non-woven fabric of less than 300, the basis weight is 300
g / m ² or less.

Further, the moisture-absorbing and desorbing nonwoven fabric of the present invention can be used at 20 ° C.
20 ° C, 90% R from equilibrium moisture absorption at 45% RH
Moisture absorption time until equilibrium moisture absorption state at H (t ₁ )
Is less than 60 minutes, more preferably less than 50 minutes, even more preferably less than 40 minutes. If it exceeds 60 minutes, it becomes difficult to obtain a desired moisture absorption rate. This may cause a problem that the humidity in the insole at the time cannot be easily lowered. Further, the moisture release time (t ₂ ) from the equilibrium moisture absorption state at 20 ° C. and 90% RH to the equilibrium moisture absorption state at 20 ° C. and 45% RH is preferably less than 60 minutes, more preferably within 50 minutes. , More preferably within 40 minutes. When the time is 60 minutes or more, it becomes difficult to obtain a desired moisture release rate, and for example, when applied to insoles, a problem such as lack of quick drying may occur.

As a specific means for imparting such moisture absorbing / releasing properties to the nonwoven fabric, for example, regardless of the basis weight of the base nonwoven fabric, the hygroscopic fine particles should be about 10 g / m ² or more, more preferably 15 g / m ² or more. It is preferable to contain about ² or more, and the air permeability of the nonwoven fabric is 5 cc / cm.
More preferably, it is maintained at about ² / sec or more.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following Examples, and the scope of the present invention can be adapted to the above and following points. It is also possible to carry out the present invention with appropriate modifications, and all of them are included in the technical scope of the present invention. The evaluation methods used in the following Examples and Comparative Examples are as follows.

Intrinsic viscosity of polyester [dl / g] A mixed solution of phenol and tetrachloroethane in a ratio of 6: 4 (mass ratio) was used as a solvent, and 0.1 g of a sample was dissolved in 25 ml of the solvent. Measurement, fineness [dtex] Using a scanning electron micrograph, measure the fiber diameter at n = 20, calculate by performing density correction, and calculate the basis weight [g / m ² ] JIS L 19064.2 (mass per unit area)
The tensile strength per unit weight [N / 5 cm / (g /
m ² )] The tensile strength measured in accordance with JIS L 19064.3 (tensile strength and elongation) is calculated according to JIS L 1906.
Calculated by dividing by the basis weight measured in accordance with 4.2 (mass per unit area), moisture absorption [mass%] A 5 cm × 10 cm square sample was heated at 80 ° C.
After drying for an hour, the mass W ₀ (g) is measured. Next, the sample was
Mass W after equilibrium moisture absorption by standing under conditions of 90 ° C and 90% RH
₁ (g) is measured, and the moisture absorption (a) is determined by the following equation.
Next, this sample was left under conditions of 20 ° C. and 45% RH, and the mass W ₂ (g) after equilibrium moisture absorption was measured, and the moisture absorption rate (b) was calculated by the following equation. A (mass%) = [(W ₁ −W ₀ ) ÷ W ₀ ] × 100... B (mass%) = [(W ₂ × W ₀ ) ÷ W ₀ ] × 100... Moisture absorption / desorption time [min] 20 ° C., 45% RH 20 ℃ from equilibrium moisture absorption state at
The time required to reach an equilibrium moisture absorption state by leaving the device under the condition of 90% RH is defined as a moisture absorption time (t ₁ ). The time required to reach the equilibrium moisture absorption state by the moisture release time (t
₂ ) Ask for it. Air permeability [cc / cm ² / sec] Measured in accordance with JIS L 19064.8 [Breathability (1) Frazier method]. Cut the drop-off resistant sample into a 20 cm square, and place the cut face down. When hitting, visually check whether powder or fiber falls off, and if there is no falling off, mark ○, if there is a little dropping, △, if there is a lot of dropping, ×, evaluate only ○ as good, antibacterial The test was carried out according to the Unified Test Method Manual (Fiber Product New Function Evaluation Council), Staphylococcus aureus ATCC 6538P was used as the test strain, and the antifungal test was JIS Z 29116.2.1 (dry method). ). Aspergillus niger (IFO
6341), Penisillium citrinum (IFO 6352), Chaetoniu
m globosum (IFO 6347), Myrothecium verrucaria (IF
O 6113).

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.63 was spun, cooled, drawn, spread and collected by a spun bond method, and the basis weight was 80 g composed of long fibers of 3.3 dtex.
/ M ² of nonwoven web was produced. Next, after subjecting this nonwoven web to needle punching, a hydrazine-crosslinked acrylonitrile-based polymer (1.0% of the remaining nitrile group) was used.
moisture-absorbing and desorbing microparticles (average particle size: 1 mmol / g or more converted to sodium salt type carboxyl group)
μm), which is an emulsion in which “HU-300E” manufactured by Nippon Exlan Industrial Co., Ltd. is impregnated with a binder made of Konishi vinyl copolymer resin “trade name: SP7”, and then pressed and dried. Was carried out to produce a nonwoven fabric having a moisture absorbing / releasing fine particle content of 40 g / m ² . FIG. 1 and Tables 1, 2, and 3 show the characteristics of the obtained nonwoven fabric.

Example ² A nonwoven fabric having a moisture-absorbing / desorbing fine particle content of 25 g / m ² was produced in the same manner as in Example 1 except that the pressing pressure was changed. FIG. 1 and Tables 1, 2, and 3 show the characteristics of the obtained nonwoven fabric.

Example 3 Polyethylene terephthalate having an intrinsic viscosity of 0.63 was spun, cooled, drawn, spread and collected by a spun bond method, and the basis weight was 60 g of a long fiber having a fineness of 2.2 dtex.
/ M ^2, a nonwoven web was manufactured, and this was partially thermocompression-bonded using a thermocompression device including an embossing roll and a flat roll to produce a long-fiber nonwoven fabric. Next, this long-fiber nonwoven fabric was impregnated with moisture-absorbing and desorbing fine particles in the same manner as in Example 1 and then pressed and dried to produce a nonwoven fabric having a moisture-absorbing and desorbing fine particle content of 30 g / m ² . FIG. 1 and Tables 1, 2, and 3 show the characteristics of the obtained nonwoven fabric.

Comparative Example 1 In the same manner as in Example 1, a nonwoven web made of long fibers having a fineness of 3.3 dtex and having a basis weight of 80 g / m ² was produced.
Next, the nonwoven web was subjected to needle punching, and then a silica gel H powder (average particle size: 15 μm) manufactured by Nacalai Tesque, and a binder made of Konishi vinyl copolymer resin (trade name: SP7) were used. After being impregnated using, pressing and drying are performed, and the content of silica gel is 40 g.
/ M ² of nonwoven fabric. FIG. 1 and Tables 1, 2, and 3 show the characteristics of the obtained nonwoven fabric.

Comparative Example 2 In the same manner as in Example 3, a nonwoven web having a fineness of 2.2 dtex and having a basis weight of 60 g / m ² was produced.
This was partially thermocompression-bonded using a thermocompression bonding device consisting of an embossing roll and a flat roll to produce a long-fiber nonwoven fabric. Next, using this long-fiber nonwoven fabric, impregnated with silica gel in the same manner as in Comparative Example 1, and then squeezed and dried,
A nonwoven fabric having a silica gel content of 30 g / m ² was produced. FIG. 1 and Tables 1, 2, and 3 show the characteristics of the obtained nonwoven fabric.

Comparative Example 3 A nonwoven web having a fineness of 2.2 dtex and a basis weight of 30 g / m ² was produced in the same manner as in Example 3 above.
This was partially thermocompression-bonded using a thermocompression bonding device consisting of an embossing roll and a flat roll to produce a long-fiber nonwoven fabric. Next, two pieces of this long-fiber nonwoven fabric were prepared, and a silica gel H powder (average particle size: 15
μm) and a powder (melting point: 84 ° C.) made of an ethylene-vinyl acetate copolymer having an average particle diameter of 30 mesh in a ratio of 2: 1.
After applying 45 g / m ² to the mixture, the mixture was treated with a dryer at 110 ° C. for 2 minutes and pressed with a nip roll to produce a nonwoven fabric in which silica gel was sandwiched between fiber layers. The properties of the obtained nonwoven fabric are shown in FIG.
3 is shown.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

As is clear from FIG. 1 and Tables 1, 2 and 3, Examples 1 to 3 all satisfy the requirements of the present invention, and have excellent antibacterial properties with good moisture absorption and moisture absorption / desorption characteristics. And it has fungicidal properties, and powder and fibers are less likely to fall off.

On the other hand, Comparative Examples 1 and 2 have no problem in the strength of the nonwoven fabric, however, since the moisture absorption and the moisture absorption / desorption characteristics do not satisfy the specified requirements, the comparative examples have antibacterial properties, antifungal properties, and shedding properties. Inferior to 1-3. Further, in Comparative Example 3, in addition to the above-described inferiority, the air permeability is considerably inferior to Examples 1 to 3.

[0039]

Industrial Applicability The present invention is constituted as described above, and is excellent in moisture absorption / desorption characteristics and humidity control function based thereon, and also has excellent antibacterial action without adding an antibacterial agent and / or an antifungal agent. A hygroscopic nonwoven fabric which exhibits a fungicidal action, has high strength and is almost lint-free, has little loss of hygroscopic fine particles, can withstand repeated use, and has an excellent texture. . In particular, the nonwoven fabric can very effectively utilize the above-mentioned excellent performance by being applied to insole applications.

[Brief description of the drawings]

FIG. 1 is a diagram showing a moisture absorption / desorption curve of a moisture absorption / desorption nonwoven fabric obtained in Examples and Comparative Examples.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomomasa Yamada 17-9, Koami-cho, Nihonbashi, Chuo-ku, Tokyo Toyo Spinning Co., Ltd. Tokyo branch office (72) Inventor Ryosuke Nishida 3-chome, Kanaoka Higashi-cho, Okayama City, Okayama Prefecture No. 1 Inside the Xindaiji Plant, Exxon Industry Co., Ltd. (72) Shozo Shigita 3-1, Kanaoka Higashicho, Okayama City, Okayama Prefecture F term (reference) 4L033 AB01 AB07 AC07 AC10 AC15 CA18 4L047 AB07 CB01 CB10 CC16

Claims (5)

[Claims] 1. 100 parts by mass of a nonwoven fabric made of fibers having a fineness of 0.3 to 10 dtex, 2 to 100 parts by mass of moisture-absorbing and desorbing fine particles having an antibacterial effect and / or an antifungal effect are contained. % Moisture absorption after equilibrium moisture absorption (a: mass%) at 20 ° C. and 45% RH (b: mass%) satisfying the following requirements: Non-woven fabric. 10 ≦ a ≦ 100, 2 ≦ b ≦ 80, 6 ≦ (ab) ≦ 9
8 2. The moisture-absorbing and releasing nonwoven fabric according to claim 1, wherein the tensile strength per unit weight is 1.0 N / 5 cm / (g / m ² ) or more in both the longitudinal and transverse directions. 3. The moisture absorbing and releasing nonwoven fabric according to claim 1, wherein the air permeability is 5 cc / cm ² / sec or more. 4. The moisture absorption time (t ₁ ) from the equilibrium moisture absorption state at 20 ° C. and 45% RH to the equilibrium moisture absorption state at 20 ° C. and 90% RH is less than 60 minutes;
From equilibrium moisture absorption at 0 ° C and 90% RH,
Release moisture time until the equilibrium moisture state at 5% RH moisture sorption nonwoven fabric according to any one of claims 1 to 3 (t ₂₎ is less than 60 minutes. 5. The moisture absorbing and releasing nonwoven fabric according to claim 1, wherein the moisture absorbing and releasing fine particles are acrylonitrile polymer fine particles.