JP3166866B2 - Electret filter media - Google Patents
Electret filter mediaInfo
- Publication number
- JP3166866B2 JP3166866B2 JP19095691A JP19095691A JP3166866B2 JP 3166866 B2 JP3166866 B2 JP 3166866B2 JP 19095691 A JP19095691 A JP 19095691A JP 19095691 A JP19095691 A JP 19095691A JP 3166866 B2 JP3166866 B2 JP 3166866B2
- Authority
- JP
- Japan
- Prior art keywords
- fiber
- fibers
- electret
- filter medium
- present
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000835 fiber Substances 0.000 claims description 51
- 239000002245 particle Substances 0.000 description 13
- 238000000034 method Methods 0.000 description 8
- -1 polypropylene Polymers 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 239000011148 porous material Substances 0.000 description 6
- 239000004743 Polypropylene Substances 0.000 description 5
- 239000004745 nonwoven fabric Substances 0.000 description 5
- 229920001155 polypropylene Polymers 0.000 description 5
- 239000004744 fabric Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000004080 punching Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000004438 BET method Methods 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 230000000844 anti-bacterial effect Effects 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 238000000578 dry spinning Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002074 melt spinning Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000002166 wet spinning Methods 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Landscapes
- Filtering Materials (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ビル空調用フィルタ
ー、掃除機用フィルター、空気清浄機用フィルター、エ
アコン用フィルター、ＯＡ機器用フィルターマスクなど
に用いることのできる低圧力損失で高粒子除去効率のエ
レクトレット濾材に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter for a building air conditioner, a filter for a vacuum cleaner, a filter for an air purifier, a filter for an air conditioner, a filter mask for OA equipment, etc., which has a low pressure loss and a high particle removal efficiency. And an electret filter medium.
【０００２】[0002]
【従来の技術】従来、エレクトレット濾材には特公昭５
６−４７２９９号公報や特開昭５８−１９３７１３号公
報に開示された技術がある。前者の開示技術はエレクト
レット化したフィルムを小繊維状にスプリット化し、次
いで不織布状に成型したエレクトレット濾材に関するも
のである。後者の開示技術は繊維の表面に多数の凹凸を
具備した繊維の不織布からなるエレクトレット濾材に関
するものである。特公昭５６−４７２９９号公報のエレ
クトレット濾材ではエレクトレットフィルムの厚さが１
０μｍ程度のためフィルムをスプリットして得た小繊維
がたとえ数μｍ〜数十μｍの幅で作れたとしても、エレ
クトレット濾材としての繊維の総表面積は少ないもので
ある。一方、特開昭５８−１９３７１３号公報のエレク
トレット濾材では濾材を構成する繊維の断面形状が星型
で、加えて多数凹凸を具備しているため、従来の丸形の
繊維に比べると繊維の総表面積は増大するものの、星型
断面形状の繊維では圧力損失も高くなり、繊維表面の凹
凸による表面積の向上はたかだかもとの２倍程度が限度
であると言う問題がある。この圧力損失の上昇は濾材特
性としてはマイナス要因であり、これまで粒子除去効率
と圧力損失と言う二律背反する特性を満足するエレクト
レット濾材はなかった。2. Description of the Related Art Conventionally, electret filter media has been known as Japanese Patent Publication Sho 5
There are techniques disclosed in JP-A-6-47299 and JP-A-58-193713. The former disclosed technology relates to an electret filter medium in which an electretized film is split into small fibers and then formed into a nonwoven fabric. The latter disclosed technology relates to an electret filter medium made of a nonwoven fabric of fibers having a large number of irregularities on the surface of the fibers. In the electret filter medium disclosed in JP-B-56-47299, the thickness of the electret film is 1 unit.
Even if the fibrils obtained by splitting the film have a width of several μm to several tens μm because of about 0 μm, the total surface area of the fibers as the electret filter medium is small. On the other hand, in the electret filter medium disclosed in Japanese Patent Application Laid-Open No. 58-193713, the cross-sectional shape of the fibers constituting the filter medium is star-shaped and has many irregularities. Although the surface area increases, the pressure loss increases in the fiber having a star-shaped cross section, and there is a problem that the improvement of the surface area due to the unevenness of the fiber surface is limited to at most twice as much as at most. This increase in pressure loss is a negative factor in the characteristics of filter media, and there has been no electret filter media that satisfies the trade-off characteristics of particle removal efficiency and pressure loss.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、かかる前記
従来技術の問題を解決した、優れた粒子除去効率と圧力
損失の少ない濾材の提供を目的とする。SUMMARY OF THE INVENTION An object of the present invention is to provide a filter medium which solves the above-mentioned problems of the prior art and has excellent particle removal efficiency and low pressure loss.
【０００４】[0004]
【課題を解決するための手段】本発明者らはこれらの二
律背反する特性を満足する高粒子除去効率で低圧力損失
のエレクトレット濾材について検討してきた結果、本発
明に到達したものである。本発明は濾材を構成する主た
る繊維が繊維表面から内部にわたって微細孔を有しＢＥ
Ｔ表面積が少なくとも２０ｍ2／ｇであるエレクトレッ
ト繊維であることを特徴とするエレクトレット濾材に関
する。本発明におけるエレクトレット繊維の有する微細
孔とは、約数ｎｍ〜数千ｎｍの孔や割れ目であり、光学
顕微鏡又は電子顕微鏡で可視可能な範囲のもので繊維状
表面から内部にわたって分布し、これらの孔や割れ目の
壁面が繊維表面と同様にエレクトレット化されてなるも
のである。Means for Solving the Problems The present inventors have studied an electret filter medium having a high particle removal efficiency and a low pressure loss which satisfies these trade-off characteristics, and as a result, have reached the present invention. In the present invention, the main fiber constituting the filter medium has fine pores extending from the fiber surface to the inside thereof.
The present invention relates to an electret filter medium, which is an electret fiber having a T surface area of at least 20 m 2 / g. The micropores of the electret fibers in the present invention are pores or cracks of about several nm to several thousand nm, distributed from the fibrous surface to the inside in a range visible with an optical microscope or an electron microscope, and The wall surfaces of the holes and cracks are formed into electrets like the fiber surface.
【０００５】本発明における微細孔を有するエレクトレ
ット繊維はあらかじめエレクトレット化した繊維を後加
工で微細孔化するとか、先に微細孔化した繊維をつく
り、後でエレクトレット化するなど、いずれの手順であ
ってもかまわない。本発明における繊維表面から内部に
わたって微細孔を有する繊維の製法は微細孔形成剤を添
加配合したポリマーを溶融紡糸した後に繊維から微細孔
形成剤を除去するとか、ある種の溶剤で繊維を表面から
内部にわたってエッチングして微細孔を形成するとか、
乾式紡糸や湿式紡糸における繊維化では溶剤が抜ける過
程で孔よ割れ目を形成させるなどの方法がある。これら
の微細孔の構造は繊維表面層に存在する比較的浅い孔や
割れ目から繊維内部まで及ぶ連続あるいは不連続の微細
孔の形態がある。本発明における微細孔を有する繊維の
空隙率は１０〜６０％であり、好ましくは２０〜５０％
である。空隙率がこれらの範囲以下だとエレクトレット
効果が低く好ましくなく、又これ以上の領域では繊維の
引張強度の低下が著しく濾材として使用できなくなると
言う問題が生じるのである。この空隙率は繊維の直径か
ら算出した繊度から単位長さ、重量から求めた繊度を減
じ、繊維の直径から算出した繊度で除した値の百分率で
示される。Electret fibers having micropores according to the present invention can be prepared by any of the following procedures, for example, a method in which previously electretized fibers are microporated by post-processing, or a method in which microporous fibers are formed first and then electretized later. It doesn't matter. In the present invention, the method for producing a fiber having fine pores from the fiber surface to the inside is to remove the fine pore forming agent from the fiber after melt-spinning a polymer to which the fine pore forming agent is added or blended, or to remove the fiber from the surface with a certain solvent. Etching over the inside to form fine holes,
In fiber spinning in dry spinning or wet spinning, there is a method of forming cracks by holes in the process of removing the solvent. The structure of these micropores has a form of continuous or discontinuous micropores extending from relatively shallow holes or cracks existing in the fiber surface layer to the inside of the fiber. The porosity of the fiber having micropores in the present invention is 10 to 60%, preferably 20 to 50%.
It is. If the porosity is less than these ranges, the electret effect is low, which is not preferable. If the porosity is higher than this range, the tensile strength of the fiber is significantly reduced and the fiber cannot be used as a filter medium. The porosity is expressed as a percentage of a value obtained by subtracting the unit length and the size obtained from the weight from the size calculated from the fiber diameter and dividing by the size calculated from the fiber diameter.
【０００６】本発明における微細孔を有する繊維の表面
積はＢＥＴ法で測定され、その表面積は少なくとも２０
ｍ2 ／ｇが好ましく微細孔化しない繊維と比較すると５
倍以上、好ましくは１０倍以上、より好ましくは５０倍
以上である。かかる表面積の増大からして、繊維表面に
凸凹を具備させる特開昭５８−１９３７１３号公報とは
異なるものである。本発明においてエレクトレット化の
方法に関しては特に限定するものではなく、いずれの方
法も用いることができ、コロナ放電、電子線照射、熱間
電界荷電などがその例である。本発明において微細孔を
有する繊維がエレクトレット化されると従来の微細孔を
有しない繊維に比べて、部分的に表面電化密度が高くな
るばかりでなく、繊維の総表面積も大幅に増えているた
め、粒子除去効率が飛躍的に増大するのである。[0006] The surface area of the fibers having micropores in the present invention is measured by the BET method, and the surface area is at least 20.
m 2 / g is preferable, and is 5
The ratio is at least 10 times, preferably at least 10 times, more preferably at least 50 times. Due to such an increase in surface area, this is different from JP-A-58-193713 in which the fiber surface is provided with irregularities. In the present invention, the method of electretization is not particularly limited, and any method can be used, and examples thereof include corona discharge, electron beam irradiation, and hot electric field charging. In the present invention, when the fibers having micropores are electretized, compared with the conventional fibers having no micropores, not only the surface electrification density is partially increased, but also the total surface area of the fibers is significantly increased. Thus, the particle removal efficiency is dramatically increased.
【０００７】本発明における微細孔を有する繊維を構成
するポリマーはポリプロピレン、ポリエチレン、α−ポ
リオレフィン、ポリエステル、ポリカーボーネート、ポ
リアクリロニトリル、ポリ弗化ビニリデン、テフロン等
やそれらの混合物が挙げれる。本発明における微細孔を
有する繊維の断面形状は円形、多角形、矩形、中空形、
Ｙ形、Ｘ形などがある。本発明における微細孔を有する
繊維の直径は１〜１００μｍ、好ましくは５〜５０μ
ｍ、より好ましくは１０〜３０μｍである。本発明にお
いて濾材を構成する主たる繊維は微細孔を有するエレク
トレット繊維であり、必要により布帛の強度、難燃性、
抗菌性、芳香性、吸着性、嵩高性、色彩性等の機能付与
のために他の繊維等の材料を併用することによってエレ
クトレット濾材とすることができる。機能付与のための
他の繊維等の材料の併用量は特に限定するものではない
が例示すれば０〜５０％、好ましくは１０〜４０％の範
囲であり、その併用状態は混合状態であっても、非混合
で層分離状態であってもかまわない。本発明のエレクト
レット濾材は織布、編布、組布、不織布などの布帛の形
態を有する。The polymer constituting the fiber having micropores in the present invention includes polypropylene, polyethylene, α-polyolefin, polyester, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, Teflon and the like, and mixtures thereof. The cross-sectional shape of the fiber having micropores in the present invention is circular, polygonal, rectangular, hollow,
There are Y type and X type. The diameter of the fiber having micropores in the present invention is 1 to 100 μm, preferably 5 to 50 μm.
m, more preferably 10 to 30 μm. The main fibers constituting the filter medium in the present invention are electret fibers having fine pores, and if necessary, the strength of the fabric, flame retardancy,
An electret filter medium can be obtained by using materials such as other fibers in combination for imparting functions such as antibacterial properties, aromatic properties, adsorptivity, bulkiness, and color. The combined amount of other materials such as fibers for imparting a function is not particularly limited, but is, for example, 0 to 50%, preferably 10 to 40%, and the combined state is a mixed state. May be in a non-mixed and layer-separated state. The electret filter medium of the present invention has a form of a fabric such as a woven fabric, a knitted fabric, a braided fabric, and a nonwoven fabric.
【０００８】〔実施例〕 実施例１ 繊度が３デニール、繊維の総表面積が５５ｍ2 ／ｇで空
隙率が２５％のポリプロピレン繊維を６０％と繊度３デ
ニール、繊維の総表面積が０．１８ｍ2 ／ｇのレギュラ
ーポリプロピレン繊維４０％とをカードで均一に混合
し、フリースを積層後、ニードルパンチング加工をして
目付１００ｇ／ｍ2 ，厚さ２．５ｍｍの不織布を作製し
た。次にコロナ放電でもって印加電圧１０ＫＶで１０秒
間エレクトレット化処理をして実施例１の濾材を作製し
た。比較のため、実施例１で用いたレギュラーポリプロ
ピレン繊維１００％で実施例１と同様の条件で不織布
（厚さ２．４ｍｍ）を作製し、エレクトレット化して比
較例１を作製した。次にこれら実施例１と比較例１の濾
材について、大気塵粒子（粒子直径０．３〜０．５μ
ｍ）を用いて、通過線速１０ｃｍ／秒でマノスターゲー
ジで圧力損失を、フィルターの上流、下流の大気塵粒子
濃度から粒子除去効率を測定した。この時に用いた計測
器はレーザーパーティクルカウンター（リオン製、ＫＣ
−１４）であった。結果を表１に示した。この表から明
らかなごとく、本発明の実施例１は比較例１と比べて同
一圧力損失で極めて高い粒子除去効率を有することが判
った。この粒子除去効率は比較例１の濾材を３枚重ね合
わせた比較例２と比べてもより高い粒子除去効率であっ
た。Examples Example 1 60% polypropylene fiber having a fineness of 3 denier and a total fiber surface area of 55 m 2 / g and a porosity of 25%, a fineness of 3 denier and a total fiber surface area of 0.18 m 2 / G of regular polypropylene fiber of 40 g / g were uniformly mixed with a card, and after fleece was laminated, needle punching was performed to produce a nonwoven fabric having a basis weight of 100 g / m 2 and a thickness of 2.5 mm. Next, the filter material of Example 1 was produced by performing electretization treatment at an applied voltage of 10 KV for 10 seconds by corona discharge. For comparison, a non-woven fabric (2.4 mm in thickness) was produced under the same conditions as in Example 1 using 100% of the regular polypropylene fibers used in Example 1, and electretized to produce Comparative Example 1. Next, for the filter media of Example 1 and Comparative Example 1, air dust particles (particle diameter 0.3 to 0.5 μm) were used.
m), the pressure loss was measured with a Manostar gauge at a passing linear velocity of 10 cm / sec, and the particle removal efficiency was measured from the concentration of atmospheric dust particles upstream and downstream of the filter. The measuring instrument used at this time was a laser particle counter (Rion, KC
-14). The results are shown in Table 1. As is clear from this table, it was found that Example 1 of the present invention had an extremely high particle removal efficiency with the same pressure loss as Comparative Example 1. This particle removal efficiency was higher than that of Comparative Example 2 in which three filter media of Comparative Example 1 were stacked.
【０００９】実施例２ 繊度が２．３デニール、繊維の総表面積が３９ｍ2 ／ｇ
で空隙率が４０％のポリエチレン繊維を５０％と繊度３
デニール、繊維の総表面積が０．１８ｍ2 ／ｇのレギュ
ラーポリプロピレン繊維５０％とをカードで均一に混合
し、フリースを積層後、ニードルパンチング加工をして
目付１００ｇ／ｍ2 、厚さ２．３ｍｍの不織布を作製し
た。次にコロナ放電でもって印加電圧１０ＫＶで１０秒
間エレクトレット化処理をして実施例２の濾材を作製し
た。実施例２の濾過特性は実施例１と同様の条件で測定
した。結果を表２に示した。この表から明らかなごと
く、本発明の実施例２は表１の比較例２と比べて、ほぼ
同一粒子除去効率で極めて低い圧力損失を有することが
判った。Example 2 A fineness of 2.3 denier and a total fiber surface area of 39 m 2 / g
50% polyethylene fiber with porosity of 40% and fineness of 3
Denier, 50% of regular polypropylene fiber having a total fiber surface area of 0.18 m 2 / g are uniformly mixed with a card, and after laminating a fleece, needle punching is performed to obtain a basis weight of 100 g / m 2 and a thickness of 2.3 mm. Was produced. Next, an electretization treatment was performed at an applied voltage of 10 KV for 10 seconds by corona discharge to produce a filter medium of Example 2. The filtration characteristics of Example 2 were measured under the same conditions as in Example 1. The results are shown in Table 2. As is clear from this table, it was found that Example 2 of the present invention had an extremely low pressure loss and almost the same particle removal efficiency as Comparative Example 2 in Table 1.
【表１】 [Table 1]
【表２】 [Table 2]
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平１−194912（ＪＰ，Ａ) 特開 平２−241509（ＪＰ，Ａ) 特開 昭55−134621（ＪＰ，Ａ) 特開 昭62−277119（ＪＰ，Ａ) 特開 平３−249911（ＪＰ，Ａ) 特開 昭61−174915（ＪＰ，Ａ) 特開 平５−7711（ＪＰ，Ａ) 実開 平１−88716（ＪＰ，Ｕ) 特公 昭56−47299（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.7，ＤＢ名) B01D 39/00 - 39/20 ────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-1-194912 (JP, A) JP-A-2-241509 (JP, A) JP-A-55-134621 (JP, A) JP-A-62-194 277119 (JP, A) JP-A-3-249911 (JP, A) JP-A-61-174915 (JP, A) JP-A-5-7711 (JP, A) JP-A-1-88716 (JP, U) JP-B-56-47299 (JP, B2) (58) Fields investigated (Int. Cl. 7 , DB name) B01D 39/00-39/20
Claims (1)
ら内部にわたって微細孔を有しＢＥＴ表面積が少なくと
も２０ｍ2 ／ｇであるエレクトレット繊維であることを
特徴とするエクトレット濾材。1. An electret filter medium characterized in that main fibers constituting the filter medium are electret fibers having micropores extending from the fiber surface to the inside and having a BET surface area of at least 20 m 2 / g.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19095691A JP3166866B2 (en) | 1991-07-04 | 1991-07-04 | Electret filter media |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19095691A JP3166866B2 (en) | 1991-07-04 | 1991-07-04 | Electret filter media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH057713A JPH057713A (en) | 1993-01-19 |
| JP3166866B2 true JP3166866B2 (en) | 2001-05-14 |
Family
ID=16266476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19095691A Expired - Fee Related JP3166866B2 (en) | 1991-07-04 | 1991-07-04 | Electret filter media |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3166866B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US12532948B2 (en) | 2018-10-31 | 2026-01-27 | Samsonite Ip Holdings S.A R.L. | Luggage article including a burst resistant rim |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4670050B2 (en) * | 2004-11-26 | 2011-04-13 | 国立大学法人 東京大学 | Electret and electrostatic induction type conversion element |
| JP5252729B2 (en) * | 2009-05-29 | 2013-07-31 | 株式会社ｉｎｄｕｓｔｒｉａ | Filter element |
| JP6099330B2 (en) * | 2012-08-02 | 2017-03-22 | 日本バイリーン株式会社 | filter |
| JP6333436B2 (en) * | 2017-04-19 | 2018-05-30 | ダイワボウホールディングス株式会社 | Electrostatic filter |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5647299B2 (en) | 2008-11-18 | 2014-12-24 | エア プロダクツ アンド ケミカルズ インコーポレイテッドＡｉｒ Ｐｒｏｄｕｃｔｓ Ａｎｄ Ｃｈｅｍｉｃａｌｓ Ｉｎｃｏｒｐｏｒａｔｅｄ | Liquefaction method and liquefaction apparatus |
-
1991
- 1991-07-04 JP JP19095691A patent/JP3166866B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5647299B2 (en) | 2008-11-18 | 2014-12-24 | エア プロダクツ アンド ケミカルズ インコーポレイテッドＡｉｒ Ｐｒｏｄｕｃｔｓ Ａｎｄ Ｃｈｅｍｉｃａｌｓ Ｉｎｃｏｒｐｏｒａｔｅｄ | Liquefaction method and liquefaction apparatus |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US12532948B2 (en) | 2018-10-31 | 2026-01-27 | Samsonite Ip Holdings S.A R.L. | Luggage article including a burst resistant rim |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH057713A (en) | 1993-01-19 |
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