JPH05202217A - Porous polytetrafluoroethylene film - Google Patents
Porous polytetrafluoroethylene filmInfo
- Publication number
- JPH05202217A JPH05202217A JP4196663A JP19666392A JPH05202217A JP H05202217 A JPH05202217 A JP H05202217A JP 4196663 A JP4196663 A JP 4196663A JP 19666392 A JP19666392 A JP 19666392A JP H05202217 A JPH05202217 A JP H05202217A
- Authority
- JP
- Japan
- Prior art keywords
- polytetrafluoroethylene
- film
- semi
- ptfe
- porous
- 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.)
- Granted
Links
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Laminated Bodies (AREA)
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ポリテトラフルオロエ
チレン(以下、「ＰＴＦＥ」という。)多孔膜およびその製
法に関し、さらに詳しくは、半導体工業などのクリーン
ルームで使用される空気及び気体中の浮遊微粒子の捕獲
に適し、空気及び気体の圧力損失の小さいエアフィルタ
ーとしての優れた新規なＰＴＦＥ多孔膜およびその製法
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polytetrafluoroethylene (hereinafter referred to as "PTFE") porous membrane and a method for producing the same, and more specifically, it is suspended in air and gas used in a clean room such as the semiconductor industry. The present invention relates to a novel PTFE porous membrane which is suitable as an air filter suitable for capturing fine particles and has a small pressure loss of air and gas, and a method for producing the same.
【０００２】[0002]
【従来の技術】クリーンルームで使用されるエアフィル
ターの材料として、ガラス繊維にバインダーを加えて抄
紙した濾材が多く使用されている。しかし、このような
濾材にはいくつかの欠点がある。例えば、濾材中の付着
小繊維の存在、または加工による折り曲げ時の自己発塵
の発生、あるいは自己発塵を防ぐためにバインダーを増
大させると圧力損失が増大することなどである(特開昭
６３−１６０１９号公報参照)。さらに、この濾材は、
フッ酸などのある種の化学薬品と接触するとガラス及び
バインダーの劣化により、発塵するという問題もあっ
た。2. Description of the Related Art As a material for an air filter used in a clean room, a filter material produced by adding a binder to glass fiber and making a paper is often used. However, such filter media have some drawbacks. For example, the presence of adhering fibrils in the filter medium, the occurrence of self-dusting during bending due to processing, or the increase of the binder to prevent self-dusting increases the pressure loss (Japanese Patent Laid-Open No. 63- 16019). Furthermore, this filter medium
There is also a problem in that dust is generated due to deterioration of the glass and the binder when brought into contact with certain chemicals such as hydrofluoric acid.
【０００３】これらの問題を解決するために合成繊維の
エレクトレット濾材(特開昭５４−５３３６５号公報参
照)を用いることが提案されているが、エレクトレット
の減衰の発生が示されている。In order to solve these problems, it has been proposed to use a synthetic fiber electret filter medium (see Japanese Patent Laid-Open No. 54-53365), but it has been shown that electret damping occurs.
【０００４】そこで、これらの欠点を防ぎ、清浄空間を
得るための手段としてＰＴＦＥの延伸多孔膜を補助手段
として用いることが提案されている(特開昭６３−１６
０１９号公報及び特開平２−２８４６１４号公報)。し
かしこの提案も、圧力損失の増大を防ぐために孔径１μ
m以上の多孔膜を使用している。この提案などで見られ
る孔径よりも小さな浮遊粒子を捕集できるとされる理由
は次の様な理論である。Therefore, it has been proposed to use a stretched porous PTFE membrane as an auxiliary means for preventing these drawbacks and obtaining a clean space (Japanese Patent Laid-Open No. 63-16).
019 and JP-A-2-284614). However, this proposal also has a pore size of 1μ in order to prevent an increase in pressure loss.
A porous membrane with a size of m or more is used. The reason why it is possible to collect suspended particles smaller than the pore size seen in this proposal is as follows.
【０００５】流体中の粒子の除去メカニズムは次の三つ
の主要メカニズムがあるとされている(ドムニク・ハン
ター・フィルターズ・リミテッド(Ｄomnick Ｈunter Ｆ
ilters Ｌimited)カタログ参照): １)直接遮断:比較的大きな粒子はマイクロ・ファイバー
によって遮断され、あたかもふるいにかけられたように
除去されるメカニズム。 ２)慣性衝突:粒子がマイクロ・ファイバーの間の曲りく
ねった通り道を通過する際、気体ほどには迅速に方向転
換できず、結局マイクロ・ファイバーに衝突し付着する
メカニズム。 ３)拡散／ブラウン運動:非常に小さい粒子は分子間力や
静電気に支配され、気体中を螺旋状に回転運動する結
果、見掛けの径が大きくなり、慣性衝突と同様に、マイ
クロ・ファイバーに付着するメカニズム。 その他にエレクトレット繊維の電荷捕集のメカニズムで
除去する方法(特開昭５４−５３３６５号公報)が提案さ
れているが、特開平２−２８４６１４号公報に記載され
たデータが示すように、１μm以下の粒子を完全に除去
できるものでないことがわかる。The removal mechanism of particles in a fluid is said to have the following three main mechanisms (Domnick Hunter Filters Limited).
ilters (Limited) Catalog reference): 1) Direct blocking: A mechanism whereby relatively large particles are blocked by microfibers and removed as if they were sieved. 2) Inertial Collision: A mechanism by which particles do not turn as quickly as gases as they pass through the tortuous path between microfibers and eventually collide with and attach to microfibers. 3) Diffusion / Brownian motion: Very small particles are dominated by intermolecular force and static electricity, and as a result of spiraling motion in a gas, the apparent diameter becomes large and attaches to microfibers, similar to inertial collision. Mechanism to do. In addition, a method of removing the electret fibers by a mechanism of collecting charges (Japanese Patent Laid-Open No. 54-53365) has been proposed, but as shown by the data described in Japanese Laid-Open Patent Publication No. 2-284614, it is 1 μm or less. It can be seen that the particles cannot be completely removed.
【０００６】フィルター濾材として用いられるＰＴＦＥ
多孔膜の代表例は、特公昭５６−１７２１６号公報に開
示されている。この発明では、圧損の小さいフィルター
膜とするために延伸倍率を大きくとり、空孔率を増大さ
せる必要がある。そのために結果として孔径が大きくな
る。逆に孔径を小さくしようとすると延伸倍率が大きく
できないために圧損の大きい多孔膜となるのである。PTFE used as a filter medium
A typical example of the porous membrane is disclosed in Japanese Patent Publication No. 56-17216. In the present invention, it is necessary to increase the draw ratio and increase the porosity in order to obtain a filter membrane with a small pressure loss. As a result, the pore size becomes large. On the contrary, if the pore diameter is reduced, the draw ratio cannot be increased, and the porous membrane has a large pressure loss.
【０００７】[0007]
【発明が解決しようとする課題】本発明は、微小孔径
で、しかも圧損の小さいＰＴＦＥ多孔膜を提供しようと
するものである。さらには本発明は、超微粒子の捕集性
能の向上したフィルター濾材を提供しようとするもので
ある。SUMMARY OF THE INVENTION The present invention is intended to provide a PTFE porous membrane having a fine pore size and a small pressure loss. Furthermore, the present invention is intended to provide a filter medium having improved collection performance of ultrafine particles.
【０００８】[0008]
【課題を解決するための手段】上記課題を解決する為、
本発明は、ＰＴＦＥ半焼成体を二軸方向に伸張面積倍率
で少なくとも５０倍に延伸し、ＰＴＦＥの融点以上の温
度で熱処理することによって、多孔膜が圧倒的にフィブ
リルからなり、即ち走査型電子顕微鏡写真の画像処理に
よるフィブリルと結節の面積比が９９:１〜７５:２５で
あり、平均フィブリル径が０．０５μm〜０．２μmであ
り、結節の最大面積が２μm2以下であり、さらに平均孔
径が０．２〜０．５μmであるＰＴＦＥ多孔膜を提供す
る。[Means for Solving the Problems] In order to solve the above problems,
In the present invention, a semi-sintered PTFE material is biaxially stretched at a stretching area ratio of at least 50 times and heat-treated at a temperature equal to or higher than the melting point of PTFE, whereby the porous membrane is predominantly composed of fibrils, that is, scanning electron The area ratio of fibrils and nodules by image processing of micrographs is 99: 1 to 75:25, the average fibril diameter is 0.05 μm to 0.2 μm, the maximum area of nodules is 2 μm 2 or less, and the average. Provided is a PTFE porous membrane having a pore size of 0.2 to 0.5 μm.
【０００９】また、本発明は、厚みが半焼成体の約２０
分の１以下(半焼成体の元の厚みがたとえば１００μmな
ら、延伸焼成後５μm以下となる)で、平均孔径が０．２
〜０．５μmであり、５．３cm／秒の流速で空気を透過
させたときの圧力損失が１０〜１００mmＨ2Ｏであるこ
とを特徴とするＰＴＦＥ多孔膜を提供する。Further, according to the present invention, the thickness is about 20 that of the semi-baked body.
One-third or less (if the original thickness of the semi-fired body is, for example, 100 μm, it will be 5 μm or less after stretching and firing), and the average pore diameter is 0.2.
Provided is a PTFE porous membrane, which has a pressure loss of 10 to 100 mmH 2 O when air is permeated at a flow rate of 5.3 cm / sec.
【００１０】本発明のＰＴＦＥ多孔膜は、そのままでも
使用できるが、他の低圧損多孔質材料(補強材)とラミネ
ートして補強することもできる。ラミネートしたＰＴＦ
Ｅ多孔膜は、取り扱い性が向上する。ラミネートしたＰ
ＴＦＥ多孔膜は、プリーツ状に折り畳み、超微粒子捕集
用フィルターとして使用することができる。Although the PTFE porous membrane of the present invention can be used as it is, it can be reinforced by laminating it with another low-pressure-loss porous material (reinforcing material). Laminated PTF
The E porous film has improved handleability. Laminated P
The TFE porous membrane can be folded into pleats and used as a filter for collecting ultrafine particles.
【００１１】補強材としては、不織布、織布、メッシ
ュ、その他の多孔膜が使用できる。補強材の材質として
は、オレフィン(たとえば、ポリエチレン、ポリプロピ
レンなど)、ナイロン、ポリエステル、アラミド、又は
これらを複合したもの(たとえば、芯／鞘構造の繊維か
ら成る不織布、低融点材料と高融点材料の２層不織布な
ど)、更にフッ素系多孔膜(たとえば、ＰＦＡ(テトラフ
ルオロエチレン／パーフルオロアルキルビニルエーテル
共重合体)、ＦＥＰ(テトラフルオロエチレン／ヘキサフ
ルオロプロピレン共重合体)、ＰＴＦＥの多孔質膜など)
が例示できる。Nonwoven fabrics, woven fabrics, meshes and other porous membranes can be used as the reinforcing material. As the material of the reinforcing material, olefin (for example, polyethylene, polypropylene, etc.), nylon, polyester, aramid, or a composite thereof (for example, non-woven fabric composed of fibers of core / sheath structure, low melting point material and high melting point material 2-layer non-woven fabric), and fluorine-based porous film (for example, PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene / hexafluoropropylene copolymer), PTFE porous film, etc.)
Can be illustrated.
【００１２】とりわけ、芯／鞘構造の繊維から成る不織
布、低融点材料と高融点材料の２層不織布などが好まし
い。このような補強材は、ラミネート時に収縮しない。
また、このような補強材とのラミネート膜は、ＨＥＰＡ
フィルターとして加工しやすく、フィルターエレメント
にする際に折込みピッチが増やせる。Above all, a non-woven fabric composed of fibers having a core / sheath structure, a two-layer non-woven fabric composed of a low melting point material and a high melting point material, and the like are preferable. Such a reinforcing material does not shrink during lamination.
In addition, a laminated film with such a reinforcing material is a HEPA.
It is easy to process as a filter and the folding pitch can be increased when it is used as a filter element.
【００１３】ラミネートの態様は、補強材の片面または
両面に本発明のＰＴＦＥ多孔膜をラミネートしてもよい
し、また、本発明のＰＴＦＥ多孔膜を２枚の補強材でサ
ンドイッチしてもよい。In the laminating mode, the PTFE porous membrane of the present invention may be laminated on one side or both sides of the reinforcing material, or the PTFE porous membrane of the present invention may be sandwiched by two reinforcing materials.
【００１４】ラミネートの方法は、既知の方法の中から
適宜選択すればよく、補強材の一部を溶融して行う熱圧
着、ポリエチレン、ポリエステル、ＰＦＡなどの粉末を
接着材として用いる熱圧着、ホットメルト樹脂を用いる
熱圧着などが好ましい。The laminating method may be appropriately selected from known methods, such as thermocompression bonding by melting a part of the reinforcing material, thermocompression bonding using powder of polyethylene, polyester, PFA or the like as an adhesive material, or hot bonding. Thermocompression bonding using a melt resin is preferable.
【００１５】粒子捕集メカニズムは、前述したが、粒子
を確実に捕集する為にはフィルターの繊維に付着した粒
子の再離脱の防止や貫通粒子の遮蔽が必要である。その
為には、確実に捕集したい粒子の大きさよりも小さい孔
径のフィルター材を用いるべきである。従って、ＰＴＦ
Ｅ多孔膜にあっては平均孔径の小さいものが好ましいこ
とは言うまでもない。The particle collecting mechanism has been described above, but in order to reliably collect the particles, it is necessary to prevent the particles adhering to the fibers of the filter from re-separating and to shield the penetrating particles. For that purpose, a filter material having a pore size smaller than the size of particles to be surely collected should be used. Therefore, PTF
Needless to say, it is preferable that the E porous membrane has a small average pore size.
【００１６】フィルター材料の孔径と空孔率が同一であ
れば圧力損失は膜厚に比例するので、膜厚は薄い方が好
ましい。If the pore diameter and the porosity of the filter material are the same, the pressure loss is proportional to the film thickness, so the film thickness is preferably thin.
【００１７】フィルター材料の圧力損失、孔径、空孔
率、膜厚が同じであっても粒子捕集性能は異なるもので
あり、理論上は０．５μm以下の細かい繊維を用い又バ
インダーを可能なかぎり少量に抑える、すなわち繊維以
外の部分を減らすことが好ましいといわれている(化学
工学協会５２年会江見準講演要旨集参照)。本発明のＰ
ＴＦＥ多孔膜は、このような諸条件を満足するものであ
る。Even if the filter material has the same pressure loss, pore diameter, porosity, and film thickness, the particle collection performance is different. Theoretically, fine fibers of 0.5 μm or less can be used and a binder can be used. It is said that it is preferable to keep the amount as small as possible, that is, to reduce the parts other than the fibers (see Emi Associate Lectures of the 52nd Annual Meeting of the Chemical Engineering Society of Japan). P of the present invention
The TFE porous film satisfies these conditions.
【００１８】本発明を、製法を含めてより詳細に説明す
る。本発明で用いるＰＴＦＥ多孔膜の延伸前の材料は、
特開昭５９−１５２８２５公報で定義されたＰＴＦＥ半
焼成体に準拠するものである。このＰＴＦＥ半焼成体を
二軸方向に伸張面積倍率で少なくとも５０倍、好ましく
は少なくとも１００倍、さらに好ましくは少なくとも２
５０倍延伸し焼成した延伸多孔体の構造は、ほとんど結
節のない微細な繊維からなる特有な膜構造を有する。The present invention will be described in more detail including the manufacturing method. The material before stretching of the PTFE porous membrane used in the present invention is
This is based on the PTFE semi-sintered body defined in JP-A-59-152825. This PTFE semi-sintered body is stretched biaxially at an area magnification of at least 50 times, preferably at least 100 times, more preferably at least 2 times.
The structure of the stretched porous body that has been stretched 50 times and fired has a unique film structure composed of fine fibers with almost no knots.
【００１９】しかも、そのようにして製造したＰＴＦＥ
多孔膜の平均孔径はきわめて小さく、通常０．５μm〜
０．２μmであり、さらに膜の厚みも延伸前の２０分の
１から１００分の１程度に減少している。Moreover, the PTFE produced in this way
The average pore size of the porous membrane is extremely small, usually 0.5 μm ~
The thickness of the film is 0.2 μm, and the thickness of the film is also reduced from about 1/20 before stretching to about 1/100.
【００２０】これらの諸要件は、半導体の微細パターン
を加工する高度な清浄空間を維持するためのエアフィル
ター材料に適している。These requirements are suitable for an air filter material for maintaining a highly clean space for processing a semiconductor fine pattern.
【００２１】この様な構造のＰＴＦＥ多孔膜は、従来の
製法では到底得られないものである。例えば特公昭５６
−１７２１６号公報第１１頁左欄第２３行以下によれ
ば、「第１図には単軸方向の伸張効果が示されている
が、二軸方向における伸張でまた全方向における伸張
で、同じような小繊維形成が前記方向に生じ、くもの巣
様の或は交さ結合された形状が生成され、それに付随し
て強さが増大される。重合体の結節と小繊維との間の空
所が数と大きさとを増大するので、多孔率もまた増大す
る。」と記載され、延伸倍率の増大は孔径を大きくする
のみであった。The PTFE porous membrane having such a structure cannot be obtained by the conventional manufacturing method. For example, Japanese Patent Publication Sho 56
According to Japanese Patent Publication No. 17216, page 11, left column, line 23, “The uniaxial stretching effect is shown in FIG. 1, but the same is true for biaxial stretching and omnidirectional stretching. Such fibril formation occurs in said direction, producing a web-like or cross-bonded shape with a concomitant increase in strength between the polymer nodule and the fibrils. As voids increase in number and size, porosity also increases. ", And increasing draw ratio only increased pore size.
【００２２】圧力損失は孔径が大きくなるほど又膜厚が
薄くなるほど低くなる。そこで孔径が小さく圧力損失が
低いエアフィルターを作製するためには薄いＰＴＦＥ多
孔膜を用いれば良いことになるが、従来法(特公昭５６
−１７２１６号公報)では延伸倍率を増大させても巾も
厚みもほとんど減少しない。けれども、極端に延伸倍率
を増大させると孔径は大きくなるので、結局、延伸前の
フィルム厚みを薄くし、低倍率で延伸せざるを得ない。
しかし工業的に利用できるフィルムの延伸前厚みはせい
ぜい３０μm〜５０μmまでである。品質及び歩留りを考
えると、１００μm前後の厚みの延伸前フィルムが通常
である。The pressure loss decreases as the pore diameter increases and as the film thickness decreases. Therefore, in order to manufacture an air filter having a small pore size and a low pressure loss, a thin PTFE porous membrane may be used.
No. 17216), even if the draw ratio is increased, the width and the thickness hardly decrease. However, if the stretching ratio is extremely increased, the pore size becomes large. Therefore, it is necessary to thin the film thickness before stretching and stretch the film at a low stretching ratio.
However, the thickness of the industrially usable film before stretching is at most 30 μm to 50 μm. Considering quality and yield, a pre-stretched film having a thickness of about 100 μm is usually used.
【００２３】本発明の一つの特徴は、工業的に生産性に
支障のない厚み１００μm程度の延伸前フィルムを用い
て目的を達成することができることである。One of the features of the present invention is that the object can be achieved by using a pre-stretched film having a thickness of about 100 μm which does not affect industrial productivity.
【００２４】本発明における各パラメータの一般的は範
囲および好ましい範囲をまとめて示す。 一般的な範囲 好ましい範囲 焼成度: ０．３０〜０．８０ ０．３５〜０．７０ 延伸倍率: ＭＤ ４ 〜 ３０倍 ＭＤ ５ 〜 ２５倍 ＴＤ １０〜１００倍 ＴＤ １５ 〜 ７０倍 合計 ５０〜１０００倍 合計 ７５〜８５０倍 延伸倍率の合計が２５０倍以上の時には、焼成度が０．
３５〜０．４８であることが好ましい。 平均孔径: ０．２〜０．５μm ０．２〜０．４μm 膜厚: ０．５〜１５μm ０．５〜１０μm フィブリル／結節面積比:９９／１〜７５／２５ ９９／１〜８５／１５ 平均フィブリル径: ０．０５〜０．２μm ０．０５〜０．２μm 結節の最大面積: ２μm2以下 ０．０５〜１μm2 圧力損失: １０〜１００mmＨ2Ｏ １０〜７０mmＨ2ＯThe general range and preferred range of each parameter in the present invention are shown together. General range Preferred range Firing degree: 0.30 to 0.80 0.35 to 0.70 Stretching ratio: MD 4 to 30 times MD 5 to 25 times TD 10 to 100 times TD 15 to 70 times Total 50 to 1000 Double total 75 to 850 times When the total draw ratio is 250 times or more, the firing degree is 0.
It is preferably 35 to 0.48. Average pore size: 0.2-0.5 μm 0.2-0.4 μm Film thickness: 0.5-15 μm 0.5-10 μm Fibril / nodule area ratio: 99 / 1-75 / 25 99 / 1-85 / 15 Average fibril diameter: 0.05-0.2 μm 0.05-0.2 μm Maximum area of nodule: 2 μm 2 or less 0.05-1 μm 2 Pressure loss: 10-100 mmH 2 O 10-70 mmH 2 O
【００２５】本発明のＰＴＦＥ多孔膜は、エアフィルタ
ーとして使用できるだけでなく、例えば本発明のＰＴＦ
Ｅ多孔膜を隔壁として液体を気化させた場合、液体中の
微粒子を除去した清澄なガス体を得ることができる。そ
のような具体的な用途の一例はクリーンな加湿器の隔膜
である。The PTFE porous membrane of the present invention can be used not only as an air filter but also for example of the PTFE of the present invention.
When the liquid is vaporized using the E porous membrane as a partition, a clear gas body from which fine particles in the liquid have been removed can be obtained. One example of such a specific application is in a clean humidifier diaphragm.
【００２６】さらに本発明によれば、非常に薄いＰＴＦ
Ｅ多孔膜を工業的に生産することができ、本発明のＰＴ
ＦＥ多孔膜は撥水性を必要とする用途や通気性を必要と
する用途に使用できる。Further in accordance with the present invention, a very thin PTF
The E porous film can be industrially produced, and the PT of the present invention can be produced.
The FE porous film can be used for applications requiring water repellency and applications requiring air permeability.
【００２７】[0027]
【実施例】実施例１ ＰＴＦＥファインパウダー(ダイキン工業株式会社製「ポ
リフロン・ファインパウダーＦ−１０４」)から製造した
厚み１００μmの未延伸未焼成フィルムを３３９℃のオ
ーブン中で５０秒間加熱処理して、焼成度０．５０の連
続した半焼成フィルムを得た。 Example 1 A 100 μm thick unstretched unbaked film produced from PTFE fine powder (“Polyflon Fine Powder F-104” manufactured by Daikin Industries, Ltd.) was heat-treated in an oven at 339 ° C. for 50 seconds. A continuous semi-baked film having a baking degree of 0.50 was obtained.
【００２８】次にこの半焼成フィルムを約９cm角に裁断
し、同時及び逐次に二軸方向に延伸できる装置(株式会
社岩本製作所製)を用いて裁断フィルムの四方を装置の
クリップではさみ、雰囲気温度３２０℃で１５分間加熱
した後、フィルムの長手方向(ＭＤ方向と呼ぶ)に１００
％／秒の延伸速度で５倍に延伸した。次にフィルムの幅
方向(ＴＤ方向と呼ぶ)にＭＤ方向の長さを固定しつつ連
続的に１５倍に延伸し、合計で７５倍(面積倍率)に延伸
された多孔膜を得た。Next, this semi-baked film was cut into about 9 cm square pieces, and a device (manufactured by Iwamoto Seisakusho Co., Ltd.) capable of simultaneously and sequentially stretching in a biaxial direction was used. After heating at a temperature of 320 ° C for 15 minutes, 100 in the longitudinal direction of the film (called MD direction).
It was stretched 5 times at a stretching rate of% / sec. Next, the length in the MD direction was fixed in the width direction (referred to as TD direction) of the film, and the film was continuously stretched 15 times to obtain a porous film stretched 75 times in total (area ratio).
【００２９】この多孔膜を収縮しない様に枠で固定し、
雰囲気温度３５０℃のオーブンに３分間入れてヒートセ
ットを行った。The porous membrane is fixed with a frame so as not to shrink,
It was placed in an oven with an ambient temperature of 350 ° C. for 3 minutes for heat setting.
【００３０】実施例２ 実施例１と同じ焼成度０．５の半焼成フィルムを用い、
実施例１と同様にしてＭＤ方向に８倍、ＴＤ方向に２５
倍延伸し、合計で２００倍延伸された多孔膜を得た。こ
の多孔膜を実施例１と同様に、３５０℃で３分間ヒート
セットした。 Example 2 Using the same semi-baked film with a baking degree of 0.5 as in Example 1,
Similar to Example 1, 8 times in MD direction and 25 in TD direction
The film was stretched twice to obtain a porous film stretched 200 times in total. This porous membrane was heat set at 350 ° C. for 3 minutes in the same manner as in Example 1.
【００３１】実施例３ ＰＴＦＥファインパウダー（ダイキン工業株式会社製
「ポリフロン・ファインパウダーＦ１０４」）からペー
スト押出、圧延ロール、助剤乾燥の通常の加工法によっ
て製造した、厚み１００μｍの未延伸・未焼成フィルム
を３３８℃のオーブン中で４５秒間加熱処理して焼成度
０．４０の連続した半焼成フィルムを得た。この工程
で、熱処理前のフィルムは、幅２１５ｍｍ、比重１．５
５ｇ／ｃｍ3であり、熱処理後は、幅２００ｍｍ、比重
２．２５ｇ／ｃｍ3に変化し、厚みはほとんど変化しな
かった。 Example 3 An unstretched and unfired sheet having a thickness of 100 μm, which was produced from PTFE fine powder (“Polyflon Fine Powder F104” manufactured by Daikin Industries, Ltd.) by a usual processing method such as paste extrusion, rolling rolls and auxiliary agent drying. The film was heat-treated in an oven at 338 ° C. for 45 seconds to obtain a continuous semi-baked film having a baking degree of 0.40. In this process, the film before heat treatment has a width of 215 mm and a specific gravity of 1.5.
It was 5 g / cm 3 , and after the heat treatment, the width was changed to 200 mm, the specific gravity was changed to 2.25 g / cm 3 , and the thickness was hardly changed.
【００３２】次に、この半焼成フィルムを参考例の装置
を用いて、まず長手方向に２０倍の延伸を行った。 この長手方向の延伸条件は次の通りであった。 ロール３、４： 巻出速度０．５ｍ／分、室温、フィル
ム幅２００ｍｍ ロール６： 周速度４ｍ／分、温度３００℃ ロール７： 周速度１０ｍ／分、温度３００℃ ロール１０： 周速度１０ｍ／分、温度２５℃ ロール２： 巻取速度１０ｍ／分、室温、フィルム幅１
４５ｍｍ ロール６とロール７の外径間距離：５ｍｍ この結果、この長手方向の延伸面積倍率は計算によって
１４．５倍となる。Next, the semi-baked film was stretched 20 times in the longitudinal direction using the apparatus of Reference Example. The stretching conditions in the longitudinal direction were as follows. Rolls 3, 4: Unwinding speed 0.5 m / min, room temperature, film width 200 mm Roll 6: peripheral speed 4 m / min, temperature 300 ° C Roll 7: peripheral speed 10 m / min, temperature 300 ° C Roll 10: peripheral speed 10 m / Min, temperature 25 ° C Roll 2: Winding speed 10 m / min, room temperature, film width 1
45 mm Distance between outer diameters of roll 6 and roll 7: 5 mm As a result, the stretching area ratio in the longitudinal direction is 14.5 times by calculation.
【００３３】続いて、この長手方向延伸フィルムの両端
を連続的にクリップではさむことのできる図２５に示す
装置により幅方向に約３４倍の延伸および引き続きヒー
トセットを行った。この幅方向の延伸およびヒートセッ
ト条件は次の通りであった。 ・フィルムの走行速度 ３ｍ／分 ・予熱オーブンの温度 ３０５℃ ・幅方向延伸オーブンの温度 ３２０℃ ・熱固定オーブンの温度 ３５０℃ この結果、長手方向と幅方向の延伸の総面積倍率は計算
によってほぼ４９０倍になる。Subsequently, the longitudinally stretched film was stretched about 34 times in the width direction and subsequently heat set by a device shown in FIG. The stretching and heat setting conditions in the width direction were as follows.・ Film running speed 3 m / min ・ Temperature of preheating oven 305 ° C ・ Temperature of width-direction stretching oven 320 ° C ・ Temperature of heat-setting oven 350 ° C As a result, the total area ratio of stretching in the longitudinal direction and width direction is almost calculated. It becomes 490 times.
【００３４】実施例４ 実施例３の幅方向延伸フィルムの両面に図２５のラミネ
ート装置を用いて不織布をラミネートした。このラミネ
ート条件は次の通りであった。 ・上側不織布 エルベスＴ１００３ＷＤＯ（ユニチカ株
式会社製品） ・下側不織布 メルフィットＢＴ０３０Ｅ（ユニセル株
式会社製品） ・加熱ロールの温度 １５０℃ この不織布をラミネートした膜の圧力損失を測定したと
ころ平均２５ｍｍＨ2Ｏであった。（この測定は両端を
均等に裁断して幅８００ｍｍとしたものを幅方向に４等
分した、４ケ所の平均値であり、最大２７ｍｍＨ2Ｏ、
最小２３ｍｍＨ2Ｏであった。） Example 4 A nonwoven fabric was laminated on both sides of the widthwise stretched film of Example 3 using the laminating apparatus shown in FIG. The laminating conditions were as follows. -Upper side non-woven fabric Elves T1003WDO (product of Unitika Ltd.)-Lower side non-woven fabric Melfit BT030E (product of Unicell Co., Ltd.)-Heating roll temperature 150 ° C The pressure loss of the film laminated with this non-woven fabric is 25 mmH 2 O on average. It was (This measurement is an average value of 4 places obtained by equally cutting both ends to have a width of 800 mm and dividing it into four equal parts in the width direction, with a maximum of 27 mmH 2 O,
The minimum was 23 mmH 2 O. )
【００３５】参考例 実施例１と同じ焼成度０．５の半焼成フィルムを用い、
図１に示す装置により延伸した。すなわち、フィルム巻
出ロール１から半焼成フィルムをロール３,４,５を介し
て、ロール６,７に送り、ここでＭＤ方向へ６倍に延伸
した。延伸されたフィルムは、ロール８,９、ヒートセ
ットロール１０、冷却ロール１１およびロール１２を介
して巻取ロール２に巻取った。 Reference Example Using the same semi-baked film with a baking degree of 0.5 as in Example 1,
It stretched with the apparatus shown in FIG. That is, the semi-baked film was fed from the film unwinding roll 1 to the rolls 6 and 7 via the rolls 3, 4 and 5, and stretched 6 times in the MD direction here. The stretched film was wound around the winding roll 2 via the rolls 8 and 9, the heat setting roll 10, the cooling roll 11 and the roll 12.
【００３６】この時の延伸条件は次の通りであった。 ロール６: ロール表面温度３００℃、周速度１m／分 ロール７: ロール表面温度３００℃、周速度６m／分 ロール６とロール７の外径間距離: ５mm ロール１０: ロール表面温度３００℃。周速度はロー
ル７に同調The stretching conditions at this time were as follows. Roll 6: Roll surface temperature 300 ° C, peripheral speed 1 m / min Roll 7: Roll surface temperature 300 ° C, peripheral speed 6 m / min Distance between outer diameter of roll 6 and roll: 5 mm Roll 10: Roll surface temperature 300 ° C. The peripheral speed is synchronized with the roll 7.
【００３７】次に、前記延伸フィルムを長さ１m、幅１
５cmに裁断し、室温で幅を固定せずにＴＤ方向に４倍に
延伸し、実施例１と同様に３５０℃３分間ヒートセット
を行った。なお、この延伸フィルムには、本発明でいう
結節は認められなかった。Next, the stretched film was length 1 m and width 1
It was cut into 5 cm, stretched 4 times in the TD direction at room temperature without fixing the width, and heat-set at 350 ° C. for 3 minutes as in Example 1. No nodule according to the present invention was observed in this stretched film.
【００３８】実施例１、２及び３、参考例、および比較
例として市販の０．１μm多孔膜２種に付いて、平均孔
径、膜厚、フィブリル／結節面積比、平均フィブリル
径、結節の最大面積及び圧力損失を測定した。測定方法
は後記の通りである。結果を表１に示す。The average pore diameter, film thickness, fibril / nodule area ratio, average fibril diameter, and maximum number of knots of Examples 1, 2 and 3, Reference Examples, and two commercially available 0.1 μm porous membranes as comparative examples Area and pressure loss were measured. The measuring method is as described below. The results are shown in Table 1.
【００３９】[0039]
【表１】 注: 市販品Ａ:ミリポア社製フロロガートＴＰカートリ
ッジ０．１μmに使用の多孔膜。 市販品Ｂ:アドバンテック東洋社製Ｔ３００Ａ２９３−
Ｄ ＰＴＦＥメンブレンフィルター 実施例３は、延伸膜の両端を均等に裁断して幅８００ｍ
ｍとしたのち、さらに幅方向に４等分し、これら４ケ所
を測定した平均値である。[Table 1] Note: Commercial product A: Porous membrane used for Millipore Fluorogart TP cartridge 0.1 μm. Commercial product B: T300A293-made by Advantech Toyo Co., Ltd.
D PTFE Membrane Filter In Example 3, the both ends of the stretched film were evenly cut to obtain a width of 800 m.
After m, it is an average value obtained by further dividing the width into four equal parts and measuring these four points.
【００４０】表１の結果より、本発明のＰＴＦＥ多孔膜
の平均孔径は市販品Ａ及び参考例の平均孔径とほぼ同じ
であるが、圧力損失は非常に小さいこと、逆に、本発明
の実施例１、２のＰＴＦＥ多孔膜の圧力損失は市販品Ｂ
の圧力損失と同程度であるが、市販品Ｂの平均孔径はか
なり大きいことが分かる。さらに、実施例３の様に面積
倍率を５００倍近く延伸することにより、平均孔径はほ
とんど変わらなくても、圧力損失をさらに低くすること
ができることが分かる。From the results shown in Table 1, the average pore diameter of the PTFE porous membrane of the present invention is almost the same as the average pore diameter of the commercial product A and the reference example, but the pressure loss is very small. The pressure loss of the PTFE porous membranes of Examples 1 and 2 is the commercial product B.
It is found that the average pore diameter of the commercial product B is considerably large although it is about the same as the pressure loss of No. Furthermore, it can be seen that by stretching the area ratio near 500 times as in Example 3, the pressure loss can be further reduced even if the average pore diameter is hardly changed.
【００４１】フィブリル／結節面積比からは、市販品Ａ
よりも実施例のものの方が大きい。平均フィブリル径
は、参考例のものより実施例のものの方が細い。また、
最大結節面積は、本発明のものの方が市販品Ａよりかな
り小さい。From the fibril / nodule area ratio, the commercially available product A
The example is larger than the example. The average fibril diameter of the example is smaller than that of the reference example. Also,
The maximum knot area of the present invention is considerably smaller than that of the commercial product A.
【００４２】本明細書に記載した各特性の測定方法を説
明する。平均孔径 ＡＳＴＭ Ｆ−３１６−８６の記載に準じて測定される
ミーンフローポアサイズ(ＭＦＰ)を平均孔径とした。実
際の測定は、コールター・ポロメーター(Ｃoulter Ｐor
ometer)[コールター・エレクトロニクス(Ｃoulter Ｅle
ctronics)社(英国)製]で測定を行った。A method of measuring each characteristic described in this specification will be described. Average Pore Size Mean flow pore size (MFP) measured according to the description of ASTM F-316-86 was defined as the average pore size. Actual measurement is Coulter Porometer
ometer) [Coulter Ele
ctronics) (UK)].
【００４３】膜厚 株式会社ミツトヨ製１Ｄ−１１０ＭＨ型膜厚計を使用
し、多孔膜を５枚重ねて全体の膜厚を測定し、その膜厚
を５で割り、得られた値を１枚の膜の膜厚とした。[0043] Using the film thickness Mitutoyo Corporation Ltd. 1D-110MH type film thickness meter, the thickness of the entire measured repeatedly five porous membrane dividing the thickness at 5, one obtained value The film thickness of the film.
【００４４】圧力損失 多孔膜を直径４７mmの円形に切り出し、透過有効面積１
２．６cm2のフィルターホルダーにセットし、これの入
口側を０．４kg／cm2に加圧し、出口側から出る空気の
流量を上島製作所製流量計で調節し、多孔膜透過流速を
５．３cm／秒にに合わせた。その時の圧力損失をマノメ
ーターで測定した。A pressure loss porous membrane was cut into a circle with a diameter of 47 mm, and the effective permeation area was 1
Is set to 2.6 cm 2 of the filter holder, pressurizing it on the inlet side to 0.4 kg / cm 2, and adjusting the flow rate of the air exiting from the outlet side in Ueshima Seisakusho flowmeter 5 porous membrane permeation rate. It was set to 3 cm / sec. The pressure loss at that time was measured with a manometer.
【００４５】焼成度 本発明のＰＴＦＥ半焼成体の焼成度は次の様にして決定
される。まず、ＰＴＦＥ未焼成体から３．０±０．１mg
の試料を秤量して切取り、この試料を用いてまず結晶融
解曲線を求める。同様にＰＴＦＥ半焼成体から３．０±
０．１mgの試料を秤量して切取り、この試料を用いて結
晶融解曲線を求める。 Firing degree The firing degree of the PTFE semi-firing body of the present invention is determined as follows. First, 3.0 ± 0.1 mg from unsintered PTFE
The sample is weighed and cut out, and a crystal melting curve is first obtained using this sample. Similarly, from the semi-sintered PTFE, 3.0 ±
A 0.1 mg sample is weighed and cut out, and a crystal melting curve is obtained using this sample.
【００４６】結晶融解曲線は、示差走査熱量計(以下、
「ＤＳＣ」という。例えば島津製作所社製ＤＳＣ−５０
型)を用いて記録する。まずＰＴＦＥ未焼成体の試料
を、ＤＳＣのアルミニウム製パンに仕込み、未焼成体の
融解熱および焼成体の融解熱を次の手順で測定する。 (１) 試料を５０℃／分の加熱速度で２５０℃に加熱
し、次いで１０℃／分の加熱速度で２５０℃から３８０
℃まで加熱する。この加熱工程において記録された結晶
融解曲線の１例を図２の曲線Ａとして示す。この工程に
おいて現われる吸熱カーブのピーク位置を「ＰＴＦＥ未
焼成体の融点」または「ＰＴＦＥファインパウダーの融
点」と定義する。 (２) ３８０℃まで加熱した直後、試料を１０℃／分の
冷却速度で２５０℃に冷却する。 (３) 試料を再び１０℃／分の加熱速度で３８０℃に加
熱する。 加熱工程(３)において記録される結晶融解曲線の１例を
図２の曲線Ｂとして示す。加熱工程(３)において現われ
る吸熱カーブのピーク位置を「ＰＴＦＥ焼成体の融点」と
定義する。The crystal melting curve is measured by a differential scanning calorimeter (hereinafter referred to as
It is called "DSC". For example, DSC-50 manufactured by Shimadzu Corporation
Type). First, a sample of the PTFE unfired body is placed in a DSC aluminum pan, and the heat of fusion of the unfired body and the heat of fusion of the fired body are measured by the following procedure. (1) The sample is heated to 250 ° C. at a heating rate of 50 ° C./min and then from 250 ° C. to 380 at a heating rate of 10 ° C./min.
Heat to ℃. An example of the crystal melting curve recorded in this heating step is shown as curve A in FIG. The peak position of the endothermic curve that appears in this step is defined as "melting point of PTFE unsintered body" or "melting point of PTFE fine powder". (2) Immediately after heating to 380 ° C, the sample is cooled to 250 ° C at a cooling rate of 10 ° C / min. (3) The sample is heated again to 380 ° C. at a heating rate of 10 ° C./min. An example of the crystal melting curve recorded in the heating step (3) is shown as curve B in FIG. The peak position of the endothermic curve that appears in the heating step (3) is defined as the "melting point of the PTFE fired body".
【００４７】続いてＰＴＦＥ半焼成体について結晶融解
曲線を工程(１)に従って記録する。この場合の曲線の１
例を図３に示す。ＰＴＦＥ未焼成体、焼成体、半焼成体
の融解熱は吸熱カーブとベースラインとの間の面積に比
例し、島津製作所社製ＤＳＣ−５０型では解析温度を設
定すれば自動的に計算される。A crystal melting curve is then recorded for the PTFE semi-baked body according to step (1). 1 of the curve in this case
An example is shown in FIG. The heat of fusion of the PTFE unfired body, fired body, and semi-fired body is proportional to the area between the endothermic curve and the baseline, and in the Shimadzu DSC-50 model, it is automatically calculated if the analysis temperature is set. ..
【００４８】そこで焼成度は次の式によって計算され
る。 焼成度＝(ΔＨ1−ΔＨ3)／(ΔＨ1−ΔＨ2) ここで、ΔＨ1はＰＴＦＥ未焼成体の融解熱、ΔＨ2はＰ
ＴＦＥ焼成体の融解熱、ΔＨ3はＰＴＦＥ半焼成体の融
解熱である。ＰＴＦＥ半焼成体に関しては、特開昭５９
−１５２８２５号公報に詳細な説明がある。Therefore, the firing degree is calculated by the following formula. Firing degree = (ΔH 1 −ΔH 3 ) / (ΔH 1 −ΔH 2 ) where ΔH 1 is the heat of fusion of the PTFE unfired body, and ΔH 2 is P.
The heat of fusion of the fired TFE body, ΔH 3 is the heat of fusion of the semi-fired PTFE body. Regarding the semi-sintered PTFE, JP-A-59-59
A detailed description is given in Japanese Patent No. 152825.
【００４９】画像解析 フィブリルと結節の面積比、平均フィブリル径、最大の
結節面積は次に示す方法で測定した。多孔膜表面の写真
を走査型電子顕微鏡(日立Ｓ−４０００型蒸着は日立Ｅ
１０３０型)でとる(ＳＥＭ写真。倍率１０００倍〜５０
００倍)。この写真を画像処理装置(本体名：日本アビオ
ニクス株式会社ＴＶイメージプロセッサＴＶＩＰ−４１
００II、制御ソフト名：ラトックシステムエンジニアリ
ング株式会社ＴＶイメージプロセッサイメージコマンド
４１９８)に取り込み、結節とフィブリルに分離し、結
節のみからなる像と繊維のみからなる像を得る。結節の
みからなる像を演算処理することで最大の結節面積を求
め、フィブリルのみからなる像を演算処理しフィブリル
の平均径を求めた(総面積を総周長の１／２で割る)。フ
ィブリルと結節の面積比は、フィブリル像の面積の総和
と結節像の面積の総和の比から求めた。 Image analysis The area ratio of fibrils and nodules, average fibril diameter, and maximum nodule area were measured by the following methods. Scanning electron microscope (Hitachi S-4000 type deposition is Hitachi E
1030 type) (SEM photograph. Magnification: 1000 to 50)
00 times). This picture is an image processing device (body name: Japan Avionics Co., Ltd. TV Image Processor TVIP-41
00II, control software name: Ratoc System Engineering Co., Ltd. TV image processor image command 4198) and separate into nodules and fibrils to obtain an image consisting of only nodules and an image consisting of fibers only. The maximum nodule area was obtained by calculating the image consisting of only the nodules, and the average diameter of the fibrils was obtained by calculating the image consisting of only the fibrils (the total area is divided by 1/2 of the total perimeter). The area ratio of fibrils and nodules was calculated from the ratio of the total area of fibril images to the total area of nodule images.
【００５０】図４及び図５は、実施例１及び２で製造し
たＰＴＦＥ多孔膜の繊維構造のＳＥＭ写真をそれぞれ示
す。図６及び図７は、図４及び図５をそれぞれ画像処理
した図を示す。図８及び図９は、図６及び図７それぞれ
から分離したフィブリルの図である。図１０及び図１１
は、図６及び図７それぞれから分離した結節の図であ
る。4 and 5 show SEM photographs of the fiber structure of the PTFE porous membranes produced in Examples 1 and 2, respectively. 6 and 7 are views obtained by performing image processing on FIGS. 4 and 5, respectively. 8 and 9 are views of the fibrils separated from FIGS. 6 and 7, respectively. 10 and 11
FIG. 8 is a view of the nodule separated from each of FIGS. 6 and 7.
【００５１】図１２及び図１３は、市販品Ａ及びＢの多
孔膜の繊維構造のＳＥＭ写真をそれぞれ示す。図１４及
び図１５は、図１２及び図１３をそれぞれ画像処理した
図から分離したフィブリルの図である。図１６及び図１
７は、図１２及び図１３をそれぞれ画像処理した図から
分離した結節の図である。FIGS. 12 and 13 show SEM photographs of the fiber structure of the commercially available porous membranes A and B, respectively. 14 and 15 are diagrams of fibrils separated from the image-processed diagrams of FIGS. 12 and 13, respectively. 16 and 1
7 is a nodule diagram separated from the image-processed diagrams of FIG. 12 and FIG. 13, respectively.
【００５２】結節の定義 結節は、次のいずれかを満足するものをいう。 (１)複数のフィブリルがつながっているかたまり(図１
８:点で埋められた部分。) (２)つながっているかたまりがフィブリル径より太い
(図２１及び図２２:斜線部) (３)一次粒子及び一次粒子がかたまっていて、そこから
フィブリルが放射線状に伸びている(図１９、図２０及
び図２３:斜線部) なお、図２４は、結節とは見なさない例である。すなわ
ち、フィブリルが枝分かれしているが、フィブリルと分
岐部分の径が同じである場合、分岐分岐は結節とは見な
さない。 Definition of nodule A nodule is one satisfying any of the following. (1) A mass of multiple fibrils connected (Fig. 1
8: The part filled with dots. ) (2) The connected mass is thicker than the fibril diameter.
(FIGS. 21 and 22: hatched portion) (3) Primary particles and primary particles are aggregated, and fibrils extend radially therefrom (FIGS. 19, 20 and 23: hatched portion) Is an example not considered a nodule. That is, if the fibrils are branched, but the diameters of the fibril and the branched portion are the same, the branched branch is not regarded as a nodule.
【図１】 参考例で使用した延伸装置の模式図。FIG. 1 is a schematic diagram of a stretching device used in a reference example.
【図２】 焼成度を測定する場合にＤＳＣにより測定さ
れた未焼成ＰＴＦＥ及び焼成ＰＴＦＥの結晶融解曲線の
一例を示す図。FIG. 2 is a diagram showing an example of a crystal melting curve of unsintered PTFE and calcined PTFE measured by DSC when the degree of calcination is measured.
【図３】 焼成度を測定する場合にＤＳＣによる測定さ
れた半焼成ＰＴＦＥの結晶融解曲線の一例を示す図。FIG. 3 is a view showing an example of a crystal melting curve of semi-baked PTFE measured by DSC when measuring the degree of baking.
【図４】 実施例１で製造したＰＴＦＥ多孔膜の繊維形
状のＳＥＭ写真。FIG. 4 is an SEM photograph of the fiber shape of the PTFE porous membrane produced in Example 1.
【図５】 実施例２で製造したＰＴＦＥ多孔膜の繊維形
状のＳＥＭ写真。FIG. 5 is an SEM photograph of the fiber shape of the PTFE porous membrane produced in Example 2.
【図６】 図４を画像処理した繊維形状を示す写真。FIG. 6 is a photograph showing a fiber shape obtained by image-processing FIG.
【図７】 図５を画像処理した繊維形状を示す写真。FIG. 7 is a photograph showing a fiber shape obtained by image-processing FIG.
【図８】 図６から分離した繊維の写真。FIG. 8 is a photograph of the fiber separated from FIG.
【図９】 図７から分離した繊維の写真。FIG. 9 is a photograph of the fiber separated from FIG.
【図１０】 図６から分離した結節粒子の写真。FIG. 10 is a photograph of the nodule particles separated from FIG.
【図１１】 図７から分離した結節粒子の写真。FIG. 11 is a photograph of the nodule particles separated from FIG. 7.
【図１２】 市販品Ａの多孔膜の繊維形状のＳＥＭ写
真。FIG. 12 is a SEM photograph of the fiber shape of the porous film of the commercial product A.
【図１３】 市販品Ｂの多孔膜の繊維形状のＳＥＭ写
真。FIG. 13 is an SEM photograph of the fiber shape of the porous film of commercial product B.
【図１４】 図１２を画像処理した図から分離した繊維
形状の写真。FIG. 14 is a photograph of a fiber shape separated from the image-processed view of FIG.
【図１５】 図１３を画像処理した図から分離した繊維
形状の写真。FIG. 15 is a photograph of a fiber shape separated from the image-processed view of FIG. 13.
【図１６】 図１２を画像処理した図から分離した結節
粒子の写真。16 is a photograph of nodule particles separated from the image-processed view of FIG.
【図１７】 図１３を画像処理した図から分離した結節
粒子の写真。FIG. 17 is a photograph of nodular particles separated from the image-processed view of FIG. 13.
【図１８】 フィブリル−結節構造の一例の模式図。FIG. 18 is a schematic view of an example of a fibril-nodule structure.
【図１９】 フィブリル−結節構造の一例の模式図。FIG. 19 is a schematic diagram of an example of a fibril-nodule structure.
【図２０】 フィブリル−結節構造の一例の模式図。FIG. 20 is a schematic diagram of an example of a fibril-nodule structure.
【図２１】 フィブリル−結節構造の一例の模式図。FIG. 21 is a schematic view of an example of a fibril-nodule structure.
【図２２】 フィブリル−結節構造の一例の模式図。FIG. 22 is a schematic view of an example of a fibril-nodule structure.
【図２３】 フィブリル−結節構造の一例の模式図。FIG. 23 is a schematic diagram of an example of a fibril-nodule structure.
【図２４】 フィブリル−結節構造の一例の模式図。FIG. 24 is a schematic diagram of an example of a fibril-nodule structure.
【図２５】 実施例３および４で使用した延伸装置およ
びラミネート装置の模式図。FIG. 25 is a schematic diagram of a stretching device and a laminating device used in Examples 3 and 4.
１:フィルム巻出ロール、２:巻取ロール、３,４,５,６,
７,８,９:ロール、１０:ヒートセットロール、１１:冷
却ロール、１２:ロール、１３：フィルム巻出ドラム、
１４：巻出制御機構、１５：予熱オーブン、１６：幅方
向延伸オーブン、１７：熱固定オーブン、１８,１９：
ラミネートロール、１９：加熱ロール、２０：巻取制御
機構、２１：フィルム幅方向延伸フィルム巻取ドラム、
２２,２３：不織布取付ドラム、1: Film unwinding roll, 2: Winding roll, 3, 4, 5, 6,
7,8,9: Roll, 10: Heat Set Roll, 11: Cooling Roll, 12: Roll, 13: Film Unwinding Drum,
14: unwinding control mechanism, 15: preheating oven, 16: width direction stretching oven, 17: heat setting oven, 18, 19:
Laminating roll, 19: heating roll, 20: winding control mechanism, 21: film width direction stretched film winding drum,
22,23: Non-woven fabric mounting drum,
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｂ２９Ｋ 105:04 105:12 Ｂ２９Ｌ 7:00 4Ｆ Ｃ０８Ｌ 27:18 (72)発明者 西林 浩文 大阪府摂津市西一津屋１番１号 ダイキン 工業株式会社淀川製作所内 (72)発明者 井上 治 大阪府摂津市西一津屋１番１号 ダイキン 工業株式会社淀川製作所内 (72)発明者 山本 勝年 大阪府摂津市西一津屋１番１号 ダイキン 工業株式会社淀川製作所内 (72)発明者 楠見 智男 大阪府摂津市西一津屋１番１号 ダイキン 工業株式会社淀川製作所内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification number Internal reference number FI Technical indication B29K 105: 04 105: 12 B29L 7:00 4F C08L 27:18 (72) Inventor Hirofumi Nishibayashi Osaka Prefecture No. 1-1 Nishiichitsuya, Settsu-shi Daikin Kogyo Co., Ltd. Yodogawa Works (72) Inventor Osamu Inoue Osaka No. 1 Nishiichitsuya, Settsu-shi Daikin Kogyo Co., Ltd. Yodogawa Works (72) Inventor Katsutoshi Yamamoto Osaka Settsu 1-1 Ichikawa, Nishiichitsu, Ichikawa Yodogawa Manufacturing Co., Ltd. (72) Inventor Tomio Kusumi 1-1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industrial Co., Ltd. Yodogawa Manufacturing Co., Ltd.
Claims (6)
延伸したのちこれをポリテトラフルオロエチレン焼成体
の融点以上の温度でヒートセットしてなるポリテトラフ
ルオロエチレン多孔膜であって、走査型電子顕微鏡写真
の画像処理によるフィブリルと結節の面積比が９９:１
〜７５:２５であり、平均フィブリル径が０．０５μm〜
０．２μmであり、結節の最大面積が２μm2以下であ
り、かつ平均孔径が０．２μm〜０．５μmであることを
特徴とするポリテトラフルオロエチレン多孔膜。1. A scanning electron micrograph, which is a polytetrafluoroethylene porous film obtained by stretching a semi-fired polytetrafluoroethylene body and then heat-setting this at a temperature equal to or higher than the melting point of the fired polytetrafluoroethylene body. Area ratio of fibril and nodule by image processing of 99: 1
~ 75: 25 with an average fibril diameter of 0.05 μm ~
0.2 μm, the maximum area of the nodule is 2 μm 2 or less, and the average pore diameter is 0.2 μm to 0.5 μm.
り、かつ５．３cm／秒の流速で空気を透過させた時の圧
力損失が１０mmＨ2Ｏ〜１００mmＨ2Ｏであることを特徴
とするポリテトラフルオロエチレン多孔膜。And wherein the wherein the mean pore diameter of 0.2Myuemu～0.5Myuemu, and pressure loss with air permeated at a flow rate of 5.3 cm / sec is 10mmH 2 O~100mmH 2 O Porous polytetrafluoroethylene membrane.
二軸方向に少なくとも５０倍の伸張面積倍率で延伸し、
ポリテトラフルオロエチレン焼成体の融点以上でヒート
セットされたことを特徴とするポリテトラフルオロエチ
レン多孔膜。3. A polytetrafluoroethylene semi-baked body is stretched biaxially at a stretch area ratio of at least 50 times,
A polytetrafluoroethylene porous film, which is heat-set at a temperature equal to or higher than the melting point of a fired product of polytetrafluoroethylene.
孔質材料の上に、接着剤を介しもしくは介さずにラミネ
ートされた請求項１〜３のいずれかに記載のポリテトラ
フルオロエチレン多孔膜。4. The polytetrafluoroethylene porous membrane according to claim 1, which is laminated on an olefin-based porous material or a fluorine-based porous material with or without an adhesive.
二軸方向に少なくとも５０倍の伸張面積倍率で延伸し、
ポリテトラフルオロエチレン焼成体の融点以上でヒート
セットすることを特徴とする請求項１〜３のいずれかに
記載のポリテトラフルオロエチレン多孔膜の製法。5. A polytetrafluoroethylene semi-sintered body is stretched biaxially at a stretch area ratio of at least 50 times,
The method for producing a polytetrafluoroethylene porous film according to any one of claims 1 to 3, wherein heat setting is performed at a temperature equal to or higher than the melting point of the polytetrafluoroethylene fired body.
トラフルオロエチレン多孔膜からなるエアフィルター。6. An air filter comprising the polytetrafluoroethylene porous membrane according to any one of claims 1 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19666392A JP2792354B2 (en) | 1991-07-23 | 1992-07-23 | Polytetrafluoroethylene porous membrane |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3-182364 | 1991-07-23 | ||
| JP18236491 | 1991-07-23 | ||
| JP19666392A JP2792354B2 (en) | 1991-07-23 | 1992-07-23 | Polytetrafluoroethylene porous membrane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05202217A true JPH05202217A (en) | 1993-08-10 |
| JP2792354B2 JP2792354B2 (en) | 1998-09-03 |
Family
ID=26501188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19666392A Expired - Fee Related JP2792354B2 (en) | 1991-07-23 | 1992-07-23 | Polytetrafluoroethylene porous membrane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2792354B2 (en) |
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