JP2004314311A - Moisture absorbing and discharging nonwoven fabric structure and moisture conditioning agent using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture absorbing and discharging nonwoven fabric structure excellent in moisture absorbing and discharging properties, light and thin, also having high dimensional stability, capable of being processed into all of shapes and excellent in handleability. <P>SOLUTION: The moisture absorbing and discharging nonwoven fabric structure is composed of a three-layered structure comprising a moisture absorbing and discharging layer mainly composed of moisture absorbing and discharging fibers and heat-fusible fibers and surface sheets for holding the moisture absorbing and discharging layer and characterized in that (a) at least one of the surface sheets has moisture permeability and air permeability, (b) the difference (R<SB>1</SB>-R<SB>2</SB>) between the moisture absorbing amount R<SB>1</SB>of the moisture absorbing and discharging nonwoven fabric structure at 20°C and 95% RH and the moisture discharging amount R<SB>2</SB>thereof at 20°C and 40% RH is 30 g/m<SP>2</SP>or above and (c) the shrinkage factor after the absorption and discharge of moisture of the moisture absorbing and discharging nonwoven fabric structure is 5% or below. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４７】
【表２】

【００４８】
表２から次のことが明らかである。実施例１のテストＮｏ．１および７は吸放湿量に乏しく、調湿剤、乾燥剤、除湿剤等の用途に適さないことが判る。テストＮｏ．５は収縮率が高く寸法安定性に乏しいことが判る。一方、テストＮｏ．２〜４、６、８および９は吸放湿量が多く、優れた吸放湿性能を有するとともに収縮率も低く寸法安定性にも優れており、調湿剤、乾燥剤、除湿剤等に好適に使用できる。
【００４９】
（実施例２）
実施例１のテストＮｏ．８の本発明の吸放湿性不織布構造体を直径５０ｍｍの円形にカットし、その端部を超音波ミシンを使用してシールし、調湿剤を作製した。この調湿剤は実施例１のテストＮｏ．８の本発明の吸放湿性不織布構造体と同等の吸放湿性能と寸法安定性を有していた上に、端部からの繊維の脱落もなかった。
【００５０】
（実施例３）
実施例１のテストＮｏ．３の本発明の吸放湿性不織布構造体を２０ｍｍ×１００ｍｍの長方形にカットし、該吸放湿性不織布構造体を３枚重ねて３５ｍｍ×１１５ｍｍの長方形にカットした孔径０．２ｍｍ、開口率５％、厚さ３０μｍのポリエチレンフィルムで挟持し、その外周縁部を熱融着し、調湿剤を作製した。この調湿剤は実施例１のテストＮｏ．３の本発明の吸放湿性不織布構造体の約３倍の吸放湿性能を有し、さらに包装材外部への繊維の脱落もなかった。
【００５１】
実施例１のテストＮｏ．４の本発明の吸放湿性不織布構造体を２００ｍｍ×３００ｍｍの長方形にカットした。また、パルプシートに消臭機能を付与したシート状消臭材も２００ｍｍ×３００ｍｍの長方形にカットし、吸放湿性不織布構造体と重ねて２２０ｍｍ×３２０ｍｍの長方形にカットした目付け５０ｇ／ｍ^２のポリエステルスパンボンドで挟持し、その外周縁部を熱融着し、調湿剤を作製した。この調湿剤は実施例１のテストＮｏ．４の本発明の吸放湿性不織布構造体と同等の吸放湿性能を有し、さらに消臭機能も有していた。
【００５２】
【発明の効果】
以上のように、本発明の吸放湿性不織布構造体は、吸放湿性が優れているため、周囲の湿度が高い場合は吸湿し、周囲の湿度を下げる乾燥剤あるいは除湿剤として好適に使用することができる。また、放湿性能にも優れているため周囲の湿度が低くなると吸湿した湿気を放湿して周囲の湿度を一定に保つ調湿剤としても好適に用いることができる。さらには、本発明の吸放湿性不織布構造体は、薄くて軽く、寸法安定性も高く、あらゆる形状に加工が可能で、取扱性にも優れたものである。
【図面の簡単な説明】
【図１】本実施形態にかかる吸放湿性不織布構造体の断面図である。
【図２】本実施形態の請求項７にかかる調湿剤の一例の断面図である。
【図３】本実施形態の請求項８にかかる調湿剤の一例の断面図である。
【符号の説明】
１ 吸放湿性不織布構造体
２ 吸放湿層
３ 透湿性または通気性を有する表面シート
４ 透湿性または通気性のない表面シート
５ 請求項７にかかる調湿剤
６ 接合部
７ 請求項８にかかる調湿剤
８ 透湿性または通気性を有する包装材
９ 透湿性または通気性のない包装材
１０ 機能性シート[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a moisture-absorbing and releasing nonwoven fabric structure, and includes a desiccant used when transporting precision parts, a dew-preventing agent for industrial machinery, a desiccant for pharmaceuticals, confectionery, a dehumidifier or a showcase, a display cabinet, and the like. The present invention relates to a material suitably used as a humidifier and the like and a method of using the same.
[0002]
[Prior art]
Conventionally, deliquescent salts, such as calcium chloride and magnesium chloride, and powdered granular materials, such as silica gel, are known as materials having moisture absorption and desorption properties. Patent Document 1 discloses a sheet desiccant in which paperboard made of paper pulp is impregnated with deliquescent salts such as calcium chloride and magnesium chloride, and the paperboard is packaged with a moisture-permeable and water-impermeable film. Patent Document 2 discloses an adsorptive sheet in which a mixture of powdery silica gel as an adsorbent and a thermoplastic resin powder is sandwiched between air-permeable sheets and integrated by press molding.
[0003]
However, the deliquescent salts become liquid when they absorb moisture, and this deliquescent liquid may leak out from the end of the film. In addition, the deliquescent properties are low, and there is a problem that the deliquescent does not return to its original shape even when dehumidified. On the other hand, silica gel has moisture absorption / desorption performance, but its amount of moisture absorption / desorption is small, so it is necessary to use a large amount, and furthermore, the moisture release rate is slower than the moisture absorption rate, so it was unsuitable as a humectant. .
[0004]
Further, Patent Document 3 discloses a humidity control material composed of highly moisture-absorbing and releasing fibers. However, the humidity control material merely states the function of the highly moisture-absorbing / desorbing fiber itself, and there is no description of the structure and function of the humidity control agent.
[0005]
Furthermore, when the moisture-absorbing / desorbing fiber is formed into a nonwoven fabric with a high mixing ratio, there is a problem in that the fiber shrinks greatly due to moisture absorption and desorption, resulting in poor dimensional stability.
[0006]
[Patent Document 1]
JP-A-7-323209 [Patent Document 2]
JP-A-10-192385 [Patent Document 3]
JP-A-6-280110
[Problems to be solved by the invention]
The present invention solves the above problems, and has excellent moisture absorption and desorption properties, and is light and thin, has high dimensional stability, can be processed into any shape, and has excellent handleability. It is to provide a structure.
[0008]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have come to invent the moisture-absorbing and releasing nonwoven fabric structure of the present invention. That is, a moisture-absorbing / desorbing nonwoven fabric structure having a three-layer structure of a moisture-absorbing / desorbing layer mainly composed of a moisture-absorbing / desorbing fiber and a heat-fusible fiber, and a top sheet sandwiching the moisture-desorbing / desorbing layer, comprising: To (c).
(A) At least one of the topsheets has moisture permeability or air permeability.
(B) 20 ° C. for absorbing moisture release nonwoven structure, a moisture absorption of _{R 1} in 95% RH, 20 ° C., the difference in moisture discharge amount _{R 2} in _{40% RH (R 1 -R 2} ), 30g / m ^{Be 2} or more.
(C) The shrinkage rate of the moisture-absorbing / desorbing nonwoven fabric after moisture absorption / desorption is 5% or less.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of the moisture-absorbing and releasing nonwoven fabric structure according to the embodiment, FIG. 2 is a cross-sectional view of an example of the humidity control agent according to claim 7 of the embodiment, and FIG. 3 is claim 8 of the embodiment. It is sectional drawing of an example of such a humidity control agent.
[0010]
As shown in FIG. 1, the moisture-absorbing / desorbing nonwoven fabric structure 1 of the present invention has a three-layer structure of a moisture-absorbing / desorbing layer 2 and a top sheet 3 or 4 sandwiching the moisture-desorbing / desorbing layer 2. If the surface sheet 3 or 4 is not provided and the moisture absorbing / releasing layer 2 is exposed on the surface, stickiness is felt at the time of moisture absorption, or the moisture absorbing / releasing fiber tends to drop off at the time of moisture release (drying).
[0011]
The moisture absorbing / releasing fibers used in the moisture absorbing / releasing layer 2 of the present invention are fibers that absorb and release moisture according to the surrounding humidity environment. Preferably, the difference between the moisture absorption at 20 ° C. and 95% RH and the moisture absorption at 20 ° C. and 40% RH is 40% by weight or more. When the difference in moisture absorption is 40% by weight or more, moisture absorption and desorption can be performed quickly even for a sudden change in humidity, and the surroundings can be adjusted to an appropriate humidity. More preferably, the difference in moisture absorption is 60% by weight or more.
[0012]
The above "moisture absorption rate" is a value obtained by dividing the difference between the weight when the fiber is left for 24 hours and absorbing moisture under each condition and the absolute dry mass of the fiber by the absolute dry mass of the fiber. It is. “RH” means “relative humidity”.
[0013]
Examples of the moisture-absorbing and desorbing fibers having the above characteristics include cross-linked sodium polyacrylate fibers, and fibers obtained by hydrolyzing the surface of acrylic fibers by post-processing. These fibers may be used alone or in combination of two or more.
[0014]
Examples of commercially available products of these moisture-absorbing / desorbing fibers include, for example, "Belle Oasis" manufactured by Kanebo Gosen Co., Ltd. and "N-38" manufactured by Toyobo Co., Ltd. In particular, Bell Oasis has a moisture absorption rate of 140% at 20 ° C. and 95% RH and a moisture absorption rate of 22% at 40% RH, and the difference exceeds 100%. Further, the fiber has substantially the same moisture absorption rate and moisture release rate, and can sufficiently cope with a sudden change in humidity.
[0015]
The content of the moisture absorbing / releasing fiber in the moisture absorbing / releasing layer 2 is arbitrary, but is preferably 30 to 95% by weight. Within this range, excellent moisture absorption / release performance is exhibited, and dimensional stability and strength can be used without any problem. More preferably, it is 50 to 90% by weight.
[0016]
The heat fusible fiber used in the moisture absorbing / releasing layer 2 of the present invention is a fiber containing a component which is usually melted at 160 ° C. or less, preferably at about 90 to 130 ° C. Preferably, a composite fiber composed of a fusion component having a lower melting point than one and a non-fusion component having a higher melting point than one is used. By using such heat-fusible fibers, the fibers can be bonded to each other while maintaining an appropriate gap without using an adhesive, and a nonwoven fabric structure can be formed.
[0017]
Examples of the heat-fusible fiber preferably used in the present invention include a core using a polyolefin or a copolymerized polyester having a melting point of 110 to 130 ° C. in a sheath portion and a polyolefin or polyethylene terephthalate as a non-fusing component in a core portion. Sheath type heat fusible fibers are exemplified.
[0018]
The content of the heat-fusible fiber in the moisture absorbing / releasing layer 2 is arbitrary, but is preferably 5 to 50% by weight. Within this range, high dimensional stability and strength can be obtained while maintaining excellent moisture absorption / release performance. More preferably, it is 10 to 40% by weight.
[0019]
Fibers other than the hygroscopic fiber and the heat-fusible fiber can be used in the hygroscopic layer 2. The type of these fibers is not particularly limited. All fibers such as synthetic fibers, natural fibers, and regenerated fibers can be used. Further, by using functional fibers such as hollow fibers, flame-retardant fibers, deodorant fibers, and anti-mold fibers, the respective functions can be imparted. These fibers may be used as a mixture of two or more kinds.
[0020]
If necessary, various additives such as a powdery or granular flame retardant, a deodorant, an antibacterial agent, and a fungicide can be added to the moisture absorbing / releasing layer 2.
[0021]
The material of the topsheet 3 or 4 used in the present invention is not particularly limited, but it is necessary to use at least one of the sheets 3 having moisture permeability or air permeability. For example, as a sheet having moisture permeability, a moisture-permeable film can be used, and as a sheet having air permeability, a paper such as a tissue, a woven or knitted fabric, a perforated film obtained by perforating a fabric or a film such as a nonwoven fabric, or the like can be used. Can be used. As the sheet 4 having no moisture permeability or air permeability, a film can be used.
[0022]
When a topsheet 3 having moisture permeability or air permeability is used on both sides as shown in FIG. 1 (a), the moisture absorption / release rate is high, and as shown in FIG. When a top sheet 3 having a certain surface and a top sheet 4 having no moisture permeability or air permeability on the other side are used, the moisture absorption / release surface can be limited to one side. Further, the moisture absorption / release rate can be freely changed by appropriately changing the moisture permeability of the moisture permeable sheet or the air permeability of the permeable sheet.
[0023]
It is preferable to use a surface sheet 3 or 4 having as low a basis weight as possible. When a topsheet having a high basis weight is used, the weight of the moisture-absorbing and releasing nonwoven fabric structure 1 increases, and the weight ratio of the topsheet 3 or 4 in the moisture-absorbing and releasing nonwoven fabric structure 1 increases. This is because the moisture absorption rate as 1 decreases. Preferred basis weight of the topsheet 3 or 4 is 8~100g / ^{m 2,} more preferably from 10~70g / ^{m 2.}
[0024]
The moisture-absorbing / desorbing nonwoven fabric structure 1 of the present invention preferably has a total basis weight in the range of 50 to 1000 g / m ² . When the content is within this range, the material is lightweight and has excellent handleability as well as excellent moisture absorption / release properties. More preferably, it is 100 to 500 g / m ² .
[0025]
The moisture absorbing and releasing nonwoven fabric structure 1 of the present invention preferably has an overall thickness in the range of 0.5 to 5 mm. When the content is within this range, the moisture absorption / desorption performance does not decrease due to an appropriate gap, and it can be used in a small gap with a small thickness. More preferably, it is 0.6 to 3 mm.
[0026]
The moisture absorbing / releasing nonwoven fabric structure 1 of the present invention preferably has an apparent density in a range of 0.02 to 0.8 g / cm ³ . When it is within this range, an appropriate gap is obtained, and there is no decrease in the moisture absorption / release rate. More preferably, it is 0.05 to 0.5 g / cm ³ .
[0027]
Moisture-absorbing and desorbing nonwoven structure 1 of the present invention, 20 ° C., the moisture absorption in 95% RH _{R 1} and 20 ° C., the difference in moisture absorption _{R 2} in _{40% RH (R 1 -R 2} ) is 30 g / ^{m 2} or more Need to be When the difference between R ₁ and R ₂ is 30 g / m ² or more, sufficient performance as a humidity control agent can be obtained. R ₁ and difference R ₂ is not rapid Moisture is performed when a resulting abrupt humidity change is less than 30 g / m ^2, there is a fear that condensation occurs when severe. Preferably, the difference between R ₁ and R ₂ is 50 g / m ² or more.
[0028]
The moisture absorbing and releasing nonwoven fabric structure 1 of the present invention is required to have a shrinkage rate after absorbing and releasing moisture of 5% or less. When the shrinkage is 5% or less, the dimensional stability is high, and it can be used for many applications. If the shrinkage ratio is higher than 5%, dimensional stability is poor, and usable applications are limited. More preferably, the shrinkage is 3% or less.
[0029]
The method for producing the moisture-absorbing and releasing nonwoven fabric structure 1 of the present invention is not particularly limited. For example, a method in which fibers used for the moisture absorbing / releasing layer 2 are mixed and opened, a web is formed by a card machine, a needle punch is performed to form a nonwoven fabric, and then the topsheet 3 or 4 is laminated to form a three-layer structure. Alternatively, there is a method in which the topsheet 3 or 4 is directly laminated on a web produced by a card machine and subjected to a heat treatment to form a three-layer structure. In addition, a three-layer structure can be manufactured in one step by the air lay method. The air-lay method is preferred. According to the air-lay method, it is easy to increase the mixing ratio even for moisture-absorbing and desorbing fibers having low strength.
[0030]
As an example of the air-lay method, a fiber mixture mainly composed of moisture-absorbing / releasing fibers and heat-fusible fibers is continuously sprayed onto the air-permeable top sheet 3 on the suction net while sucking from the suction net side. After forming the moisture release layer 2, the other topsheet 3 or 4 is laminated to form a three-layer structure, and then subjected to a heat and pressure treatment, so that the fibers in the moisture absorption / desorption layer 2, the moisture absorption / desorption layer 2 And a method of forming a moisture-absorbing and releasing nonwoven fabric structure by adhering the nonwoven fabric structure to the surface sheet 3 or 4.
[0031]
For adhesion between the moisture absorbing / releasing layer 2 and the topsheet 3 or 4, a heat-fusible resin such as polyolefin or a thermoplastic resin may be used.
[0032]
The moisture-absorbing and releasing nonwoven fabric structure 1 of the present invention is usually used after being cut into an appropriate size and shape. The size and shape at this time are not particularly limited. Can be freely designed according to the application.
[0033]
When the moisture absorbing and releasing nonwoven fabric structure 1 of the present invention is cut and used, the ends are joined 6 as shown in FIG. 2 to prevent the fibers and the like in the moisture absorbing and releasing layer 2 from falling off from the ends. It is preferred to use. The method of joining 6 is not particularly limited. Examples include thermocompression bonding, ultrasonic sealing, ultrasonic sealing cutting, high frequency welding, and sealing using a thermoplastic resin. The ultrasonic seal cut method is preferable. According to the ultrasonic seal cut method, the seal width can be reduced, and high moisture absorption / release performance can be obtained efficiently.
[0034]
The moisture-absorbing / desorbing nonwoven fabric structure 1 of the present invention can be used after being cut into an appropriate size and shape and stored in a packaging material 8 or 9 as shown in FIG. At this time, the packaging material needs to be at least partially a material 8 having moisture permeability or air permeability, and the packaging material needs to have its outer peripheral edge joined 6.
[0035]
The joining method of the outer peripheral edge of the packaging material is not particularly limited. As an example, thermocompression bonding, an ultrasonic seal, a high-frequency welder, a commonly used adhesive, or the like can be given.
[0036]
The material used for the packaging material 8 or 9 is not particularly limited. For example, as the material having moisture permeability, a moisture-permeable film can be used, and as the material having air permeability, paper, woven or knitted fabric, non-woven fabric or the like, perforated film obtained by perforating a film, or the like can be used. Further, a film can be used as the material having no moisture permeability or air permeability.
[0037]
When the material 8 having moisture permeability or air permeability is used for all of the packaging materials 8 or 9 as shown in FIG. 3A, the rate of moisture absorption and desorption is high, and as shown in FIG. When a material 8 having moisture permeability or air permeability is used in part and a material 9 having no moisture permeability or air permeability is used in other parts, the moisture absorption / release surface can be limited to one side or a part. Further, the moisture absorption / release rate can be freely changed by appropriately changing the moisture permeability of the moisture permeable sheet or the air permeability of the permeable sheet.
[0038]
By using a material having functions such as flame retardancy, waterproofness, water repellency, and antistatic for the packaging material 8 or 9, it is also possible to obtain a humidity control agent having these functions.
[0039]
As shown in FIG. 3 (c), a plurality of the moisture-absorbing and releasing nonwoven fabric structures 1 of the present invention may be placed in the packaging material 8 or 9 in accordance with the application and purpose.
[0040]
Further, as shown in FIG. 3 (d), a sheet having a function of deodorizing, antibacterial and the like together with the moisture-absorbing and releasing nonwoven fabric structure 1 according to the application and purpose is included in the packaging material 8 or 9 according to the purpose. 10 may be inserted.
[0041]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.
The method for measuring the moisture absorption / release performance and the shrinkage ratio is shown below.
[0042]
(Hygroscopic performance and shrinkage)
A sample cut to 200 mm × 200 mm is left for 24 hours in an environment of 20 ° C. × 40% RH, then transferred to an environment of 20 ° C. × 95% RH, absorbed for 8 hours, and the sample weight (W ₁ ) is measured. Next, the sample is transferred again to an environment of 20 ° C. × 40% RH and allowed to dehumidify for 3 hours, and then the sample weight (W ₂ ) and the dimensions of the length and width (L ₂ , B ₂ ) are measured. Finally, the absolute dry mass (W ₀ ) of the sample is measured, and the moisture absorption / release amount per 1 m ² and the shrinkage are calculated from the following formula.
[0043]
Moisture absorption / desorption amount (g / m ² ) = R ₁ −R ₂
R ₁ ; moisture absorption (g / m ² ) = (W ₁ −W ₀ ) /0.04
R ₂ ; amount of released moisture (g / m ² ) = (W ₂ −W ₀ ) /0.04
W ₁ ; sample weight (g) after absorbing moisture at 20 ° C. × 95% RH for 8 hours
W ₂ : sample weight (g) after dehumidification at 20 ° C. × 40% RH for 3 hours
Shrinkage (%) = [400− (L ₂ + B ₂ )] / 400 × 100
L ₂ : vertical dimension (mm) of the sample after dehumidification at 20 ° C. × 40% RH for 3 hours
B ₂ : Width (mm) of the sample after moisture release at 20 ° C. × 40% RH for 3 hours
[0044]
(Example 1)
Under the conditions shown in Table 1 for the composition of the moisture absorbing / releasing layer, the material and the basis weight of the topsheet, and the basis weight and thickness of the moisture absorbing / releasing nonwoven fabric, a moisture absorbing / releasing nonwoven fabric was produced by the following production method. The moisture absorbing / releasing fiber is Kanebo Synthetic Co., Ltd. "Bell Oasis" 10 dtex, 6 mm, the heat fusible fiber is Chisso Co., Ltd. "ES" 4.4 dtex, 6 mm, and other fibers are regular polyester. 5.6 dtex, 6 mm was used.
[0045]
After mixing the fibers with the composition shown in Table 1, the fibers were continuously sprayed on the top sheet a on the suction net by the air lay method so as to form a moisture absorbing / releasing layer. Next, the surface sheet b is laminated on the moisture absorbing / releasing layer to form a three-layer structure, subjected to a heat treatment at 140 to 200 ° C., and further compressed by a roller at the exit of the heat treatment zone to adhere the whole and absorb and release. A wet nonwoven structure was obtained. Table 2 shows the measurement results of the moisture absorption / desorption amount and the shrinkage ratio.
[0046]
[Table 1]

[0047]
[Table 2]

[0048]
The following is clear from Table 2. Test No. of Example 1 Nos. 1 and 7 have poor moisture absorption and desorption amounts, and are not suitable for applications such as a humectant, a desiccant, and a dehumidifier. Test No. 5 shows that the shrinkage ratio is high and the dimensional stability is poor. On the other hand, test No. Nos. 2, 4, 6, 8 and 9 have a large amount of moisture absorption / desorption, have excellent moisture absorption / desorption performance, and have a low shrinkage ratio and excellent dimensional stability. It can be suitably used.
[0049]
(Example 2)
Test No. of Example 1 8 was cut into a circular shape having a diameter of 50 mm, and the end was sealed using an ultrasonic sewing machine to produce a humidity conditioner. This humectant was used in Test No. 1 of Example 1. In addition to having the same moisture absorption / desorption performance and dimensional stability as the moisture-absorbing / desorbing nonwoven fabric structure of the present invention of No. 8, the fibers did not fall off from the ends.
[0050]
(Example 3)
Test No. of Example 1 3 was cut into a rectangle of 20 mm × 100 mm, and the three moisture-absorbing and non-woven fabric structures were stacked on each other and cut into a rectangle of 35 mm × 115 mm, with a hole diameter of 0.2 mm and an aperture ratio of 5%. And a 30 μm-thick polyethylene film, and the outer peripheral edge thereof was heat-sealed to prepare a humidity control agent. This humectant was used in Test No. 1 of Example 1. No. 3 has about three times the moisture absorption / release performance of the moisture absorption / release nonwoven fabric structure of the present invention, and there was no loss of fibers to the outside of the packaging material.
[0051]
Test No. of Example 1 4 was cut into a 200 mm x 300 mm rectangle. Also, a sheet-like deodorizing material having a deodorizing function added to a pulp sheet is cut into a rectangle of 200 mm × 300 mm, and is superposed on a moisture-absorbing and desorbing nonwoven fabric structure and cut into a rectangle of 220 mm × 320 mm to obtain a polyester having a basis weight of 50 g / m ² . It was sandwiched by spunbond and the outer peripheral edge was heat-sealed to prepare a humidity control agent. This humectant was used in Test No. 1 of Example 1. No. 4 had the same moisture absorbing and releasing performance as the moisture absorbing and releasing nonwoven fabric structure of the present invention, and also had a deodorizing function.
[0052]
【The invention's effect】
As described above, the moisture-absorbing and releasing nonwoven fabric structure of the present invention has excellent moisture-absorbing and desorbing properties. Therefore, when the surrounding humidity is high, it absorbs moisture and is preferably used as a desiccant or a dehumidifying agent for lowering the surrounding humidity. be able to. Further, since it has excellent moisture release performance, it can be suitably used as a humidity control agent that keeps the surrounding humidity constant by releasing the absorbed moisture when the surrounding humidity becomes low. Furthermore, the moisture-absorbing and releasing nonwoven fabric structure of the present invention is thin and light, has high dimensional stability, can be processed into any shape, and has excellent handling properties.
[Brief description of the drawings]
FIG. 1 is a sectional view of a moisture-absorbing and releasing nonwoven fabric structure according to the present embodiment.
FIG. 2 is a cross-sectional view of an example of the humidity control agent according to claim 7 of the present embodiment.
FIG. 3 is a cross-sectional view of an example of a humidity control agent according to claim 8 of the present embodiment.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 moisture-absorbing and non-woven fabric structure 2 moisture-absorbing and releasing layer 3 moisture-permeable or air-permeable topsheet 4 moisture-permeable or non-permeable topsheet 5 humidity control agent 6 according to claim 7 bonding portion 7 according to claim 8 Humidifier 8 Packaging material 9 having moisture permeability or air permeability 9 Packaging material 10 having no moisture permeability or air permeability

Claims (8)

A moisture-absorbing / desorbing nonwoven fabric structure having a three-layer structure of a moisture-absorbing / desorbing layer mainly composed of a moisture-absorbing / desorbing fiber and a heat-fusible fiber, and a surface sheet sandwiching the moisture-desorbing / desorbing layer. A moisture-absorbing and releasing nonwoven fabric structure characterized by c).
(A) At least one of the topsheets has moisture permeability or air permeability.
(B) 20 ° C. for absorbing moisture release nonwoven structure, a moisture absorption of _{R 1} in 95% RH, 20 ° C., the difference in moisture discharge amount _{R 2} in _{40% RH (R 1 -R 2} ), 30g / m ^{Be 2} or more.
(C) The shrinkage rate of the moisture-absorbing / desorbing nonwoven fabric after moisture absorption / desorption is 5% or less. 2. The moisture-absorbing and releasing nonwoven fabric structure according to claim 1, wherein the heat-fusible fiber is a composite fiber comprising a fusion component having a lower melting point than one and a non-fusion component having a higher melting point than one. 3. The moisture-absorbing and releasing nonwoven fabric structure according to claim 2, wherein the heat-fusible fiber is a core-sheath type heat-fusible fiber whose sheath portion is made of polyolefin or a copolymerized polyester having a melting point of 110 to 130 ° C. body. The moisture-absorbing and releasing nonwoven fabric structure according to any one of claims 1 to 3, wherein the moisture-absorbing and releasing fiber is a crosslinked sodium polyacrylate-based moisture absorbing and releasing fiber. The moisture-absorbing and releasing nonwoven fabric structure according to any one of claims 1 to 4, wherein the content of the heat-fusible fiber in the moisture-absorbing and releasing layer is 5 to 50% by weight. Total basis weight of 50 to 1000 g / ^{m 2,} moisture-absorbing and desorbing nonwoven structure according to any one of claims 1 to 5 the total thickness of is 0.5 to 5 mm. A humidity control agent comprising an end portion of the moisture-absorbing and releasing nonwoven fabric structure according to any one of claims 1 to 6. A moisture-absorbing / desorbing nonwoven fabric structure according to any one of claims 1 to 6, or a humidity-conditioning agent containing the humidity-conditioning agent according to claim 7 in a packaging material, wherein at least a part of the packaging material is transparent. A humidity control agent comprising a material having moisture or air permeability and having an outer peripheral edge of the packaging material joined thereto.

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