JPH0596110A - Cylindrical filter and its production - Google Patents
Cylindrical filter and its productionInfo
- Publication number
- JPH0596110A JPH0596110A JP4048105A JP4810592A JPH0596110A JP H0596110 A JPH0596110 A JP H0596110A JP 4048105 A JP4048105 A JP 4048105A JP 4810592 A JP4810592 A JP 4810592A JP H0596110 A JPH0596110 A JP H0596110A
- Authority
- JP
- Japan
- Prior art keywords
- filter
- fiber
- melting point
- winding
- component
- 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
- Filtering Materials (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Nonwoven Fabrics (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、メルトブロー法による
極細繊維を筒状に巻取って成る精密ろ過用筒状フィルタ
ー及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical filter for microfiltration which is obtained by winding ultrafine fibers in a cylindrical shape by a melt blow method and a method for producing the same.
【０００２】[0002]
【従来の技術】合成繊維を円筒状に成形したフィルター
は各種のものが知られており、特公昭５６ー４３１３９
号公報には複合繊維のカードウエブを加熱しながら心棒
上に巻き取る方法が開示されている。このような方法で
は、１ｄ／ｆ以下の細い繊維は安定したカーデイングは
困難で、１０μｍ以下の微粒子を捕集するフィルターは
得られなかった。また、通常の合成繊維では、紡糸・延
伸・カーデイング等の工程での帯電防止や摩擦防止の目
的で油剤が塗布されるが、このような油剤がろ液中に流
出し、ろ液が泡立ったり、食品などを汚染するという問
題があった。一方、精密ろ過用円筒状フィルターとして
は、メルトブロー法による極細繊維を用いたフィルター
が電子機器材料の洗浄液用フィルターや除塵用エアフィ
ルター、あるいは医薬品に用いられる水等のプレフィル
ターとして広く用いられている。特開昭60-216818号公
報には、メルトブロー法で得られた繊維を相互に接着し
ない温度まで冷却した後心棒上に巻き取る方法が開示さ
れており、紡糸条件を制御して繊維の直径をフィルター
の厚み方向に徐々に変化させる方法も開示されている。
このようなフィルターでは、繊維同志の結合はほとんど
存在せず繊維間のもつれ又は絡みによって相互に固着し
たものであるから、フィルターは硬度が低く十分な耐圧
性が得られない。硬度を増す目的でウエブを加熱しなが
ら巻き取ることが考えられるが、繊維の溶融によりウエ
ブがフィルム化しろ過層の目詰まりを起こしたり空隙の
大きさが不均一になるので、ろ過ライフもろ過精度も劣
ったものとなる。特開平1ー297113号公報には、繊維径や
嵩密度の異なる数種のメルトブロー法による不織布を、
フィルターの内層が密で外層が粗となるように順次数回
ずつ巻き取る方法が開示されている。この方法では予め
何種かの不織布を準備する必要があり、製造工程が複雑
で非能率的であるのみならず、得られるフィルターも巻
き取られた不織布の層間および繊維間が接着されていな
いので、使用中に層間剥離を起こしたりフィルター端部
から液漏れを起こし易く、耐圧性の不十分なものであ
る。2. Description of the Related Art Various types of filters are known in which a synthetic fiber is molded into a cylindrical shape.
The publication discloses a method of winding a composite fiber card web on a mandrel while heating it. By such a method, stable carding of fine fibers of 1 d / f or less was difficult, and a filter for trapping fine particles of 10 μm or less could not be obtained. Also, with ordinary synthetic fibers, an oil agent is applied for the purpose of antistatic and friction prevention in the processes of spinning, drawing, carding, etc., but such oil agent flows out into the filtrate and the filtrate foams. There was a problem of contaminating foods. On the other hand, as a cylindrical filter for precision filtration, a filter using ultrafine fibers by a melt blow method is widely used as a cleaning liquid filter for electronic equipment materials, an air filter for dust removal, or a prefilter for water used for pharmaceuticals. .. JP-A-60-216818 discloses a method in which fibers obtained by a melt-blowing method are cooled to a temperature at which they do not adhere to each other and then wound on a mandrel, and the spinning conditions are controlled to control the fiber diameter. A method of gradually changing the thickness of the filter is also disclosed.
In such a filter, there is almost no bond between fibers and they are fixed to each other by entanglement or entanglement between the fibers, so that the filter has low hardness and sufficient pressure resistance cannot be obtained. It is possible to wind the web while heating it for the purpose of increasing the hardness, but because the fiber melts, the web forms a film, which causes clogging of the filtration layer and uneven pore sizes, so the filtration life is also accurate. Is also inferior. Japanese Patent Laid-Open No. 1-297113 discloses several types of nonwoven fabrics having different fiber diameters and bulk densities, which are produced by the melt blowing method.
A method is disclosed in which the filter is wound several times in sequence so that the inner layer of the filter is dense and the outer layer is rough. In this method, it is necessary to prepare some kinds of non-woven fabrics in advance, and not only the manufacturing process is complicated and inefficient, but also the obtained filter is not bonded between the layers of the wound non-woven fabric and between the fibers. In addition, delamination easily occurs during use and liquid leaks easily from the filter end portion, and the pressure resistance is insufficient.
【０００３】[0003]
【発明が解決しようとする課題】本発明は耐圧性に優
れ、ろ液を汚染せず、かつろ過ライフの長い精密ろ過用
フィルター及びその簡便な製造方法を提供することを目
的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a microfiltration filter which has excellent pressure resistance, does not contaminate the filtrate and has a long filtration life, and a simple method for producing the same.
【０００４】[0004]
【課題を解決するための手段】本発明者等は上記の課題
を解決すべく鋭意研究の結果、メルトブロー法によって
順次繊維径を変えながら紡糸して得られる極細の複合繊
維ウエブを、複合繊維の低融点成分のみを融解させるよ
うに加熱しながら巻芯に巻き取ることにより、所期の目
的が達せられることを知り本発明を完成するに至った。
即ち、本願第１の発明は、メルトブロー法により得られ
た高融点成分と低融点成分とからなる極細の複合繊維で
形成された筒状フィルターであって、該複合繊維はフィ
ルターの厚み方向に対して繊維径を順次細く変化させて
巻き取られており、かつ複合繊維の接点が低融点成分に
より融着していることを特徴とする筒状フィルターであ
る。また本願第２の発明は、繊維形成性熱可塑性樹脂か
らなる高融点成分と低融点成分とを複合メルトブロー紡
糸しながら、順次繊維径を変化させて堆積して得られた
極細複合繊維ウエブを巻芯に巻取るに際し、巻取り前及
び／又は巻取り時あるいは巻取り後のいずれかの工程
で、前記低融点成分の融点以上で高融点成分の融点以下
の温度で熱処理し、その後巻芯を抜き取ることを特徴と
する筒状フィルターの製造方法である。Means for Solving the Problems As a result of earnest research to solve the above problems, the present inventors have found that ultrafine composite fiber webs obtained by spinning while sequentially changing the fiber diameter by a melt blow method The present invention has been completed, knowing that the intended purpose can be achieved by winding it on a winding core while heating so as to melt only the low melting point component.
That is, the first invention of the present application is a tubular filter formed of ultrafine composite fibers composed of a high-melting point component and a low-melting point component obtained by a melt-blowing method, wherein the composite fiber is in the thickness direction of the filter. The cylindrical filter is characterized in that the fiber diameter is gradually changed to be gradually reduced and wound up, and the contact point of the composite fiber is fused by the low melting point component. The second invention of the present application is to wind an ultrafine composite fiber web obtained by sequentially depositing fibers having a high melting point component and a low melting point component, which are made of a fiber-forming thermoplastic resin, while performing composite melt blow spinning. At the time of winding on the core, in any step before winding and / or during winding or after winding, heat treatment is performed at a temperature not lower than the melting point of the low melting point component and not higher than the melting point of the high melting point component, and then the winding core is It is a method for manufacturing a cylindrical filter, which is characterized by extracting.
【０００５】以下、本発明を詳細に説明する。本発明で
いう筒状フィルターとは、フィルターの横断面の形状が
円形または楕円形等の円筒状フィルター、あるいは横断
面の形状が３角形又は４角形以上の多角形をした角型筒
状フィルター等である。なお、巻芯の形状が多角形（例
えば６角形、８角形等）の場合には、繊維ウエブを巻き
重ねるにつれて外形は多角形の角がマイルドになり円形
に近くなり易いが、フィルター特性への影響はない。本
発明のフィルターに用いる複合繊維には、ポリオレフィ
ン、ポリエステル、ポリアミド等の繊維形成性熱可塑性
樹脂の中から融点が好ましくは２０℃以上異なる２種の
樹脂を選び、両者を並列型に、あるいは低融点の樹脂を
鞘側に配した鞘芯型に組み合わせて複合紡糸したものを
用いる。なお、鞘芯型の場合、偏芯構造はもとより複数
の芯成分を有する構造としてもよい。また、繊維の断面
形状も、円形、楕円形、種々の異形断面にすることもで
きる。複合繊維の構造で重要なことは低融点成分が繊維
断面周の少なくとも一部を占めることである。低融点成
分が繊維断面周を占める比率は繊維軸方向に変化しても
よく特に限定されない。要は、この低融点成分が後述す
る熱処理によって繊維の各接点に融着を起こさせるよう
な複合構造であればよい。複合紡糸する高融点成分と低
融点成分の例としては、ポリエチレン／ポリプロピレ
ン、ポリプロピレン／ポリエステル、ナイロン６／ナイ
ロン６６等の組み合わせを示すことができる。これら両
樹脂の融点の差が２０℃未満であると、ウエブを巻き取
る際の加熱操作の温度範囲が狭くなるので工程管理が困
難となり好ましくない。なお、両成分の複合比（重量）
は通常８０／２０〜２０／８０であるが、好ましくは６
５／３５〜３５／６５であり、より好ましくは４５／５
５〜５５／４５である。このような複合繊維をメルトブ
ロー法で紡糸する方法としては、特開昭６０ー９９０５
７号公報に開示されたような複合紡糸口金を用い、２種
類の熱可塑性樹脂をそれぞれの押出機から紡糸口金に供
給し、紡糸口から押し出された溶融樹脂を高速の熱風で
吹き飛ばし、捕集コンベア上に極細の複合繊維として堆
積させる方法が利用できる。メルトブロー法では繊維径
の変化は、樹脂の押し出し量を増せば太くなり、熱風の
流速を増せば細くなるので、これらの条件のいずれか一
方あるいは両方を順次あるいは段階的に変化させること
により繊維径が順次あるいは段階的に変化したウエブ繊
維を得ることができる。繊維径の変化は連続的であって
もよく、段階的であってもよいが、ウエブを巻取って作
られるフィルターの厚み方向に通液方向に沿って順次細
くする。つまり、ろ液の通過方向がフィルターの外層か
ら内層にかけて行われる場合は、繊維径をフィルターの
外層から内層にかけて順次細くするのである。逆に、液
の通液方向がフィルターの内層から外層にかけて行われ
る場合は、繊維径をフィルターの内層から外層にかけて
順次細くするのである。このようにすることにより、フ
ィルターは液の入口側は太い繊維で構成された大きな空
隙を有し、液の出口側は細い繊維で構成された小さな空
隙を有する（密度勾配型の）ものとなり、フィルターの
厚み方向に微粒子を分級して捕捉するので、ろ過ライフ
の長いフィルターを得ることができる。The present invention will be described in detail below. The tubular filter referred to in the present invention is a cylindrical filter having a circular or elliptical cross-sectional shape, or a rectangular tubular filter having a triangular or tetragonal or more polygonal cross-sectional shape. Is. When the shape of the winding core is polygonal (for example, hexagonal, octagonal, etc.), the outer shape of the polygon becomes milder and the shape of the polygonal shape tends to be closer to a circular shape as the fibrous web is rolled up. There is no effect. For the composite fiber used in the filter of the present invention, two types of resins having different melting points, preferably 20 ° C. or more, are selected from the fiber-forming thermoplastic resins such as polyolefin, polyester, polyamide, etc., and both are arranged in parallel or low A composite-spun product is used in which a resin having a melting point is combined with a sheath-core type in which the resin is disposed on the sheath side. In the case of the sheath-core type, not only an eccentric structure but also a structure having a plurality of core components may be used. Further, the cross-sectional shape of the fiber can be circular, elliptical, or various modified cross-sections. What is important in the structure of the composite fiber is that the low melting point component occupies at least part of the circumference of the fiber cross section. The ratio of the low-melting point component occupying the circumference of the fiber cross section may vary in the fiber axis direction and is not particularly limited. What is essential is that the low melting point component has a composite structure that causes fusion at each contact point of the fiber by the heat treatment described later. Examples of the high-melting point component and the low-melting point component to be composite-spun include polyethylene / polypropylene, polypropylene / polyester, nylon 6 / nylon 66 and the like. If the difference between the melting points of these two resins is less than 20 ° C., the temperature range of the heating operation for winding the web is narrowed, which makes the process control difficult and is not preferable. The composite ratio (weight) of both components
Is usually 80/20 to 20/80, but preferably 6
5/35 to 35/65, more preferably 45/5
5 to 55/45. A method of spinning such a composite fiber by a melt blow method is described in JP-A-60-9905.
Using the composite spinneret as disclosed in Japanese Patent Publication No. 7, two types of thermoplastic resins are supplied from the respective extruders to the spinneret, and the molten resin extruded from the spinneret is blown off with high-speed hot air and collected. A method of depositing ultrafine composite fibers on a conveyor can be used. In the melt-blowing method, the change in fiber diameter becomes thicker as the amount of resin extruded increases, and becomes thinner as the flow velocity of hot air increases.By changing either or both of these conditions sequentially or stepwise, the fiber diameter can be changed. It is possible to obtain a web fiber in which the change is sequential or stepwise. The change in fiber diameter may be continuous or stepwise, but the thickness of the filter made by winding the web is gradually thinned along the liquid passage direction. That is, when the filtrate is passed from the outer layer to the inner layer of the filter, the fiber diameter is gradually reduced from the outer layer to the inner layer of the filter. On the contrary, when the liquid is passed from the inner layer to the outer layer of the filter, the fiber diameter is gradually reduced from the inner layer to the outer layer of the filter. By doing so, the filter has a large void made of thick fibers on the inlet side of the liquid and a small void made of thin fibers on the outlet side of the liquid (density gradient type), Since fine particles are classified and captured in the thickness direction of the filter, a filter having a long filtration life can be obtained.
【０００６】本発明では、繊維径を変化させながら堆積
させて得られた極細複合繊維ウエブを巻芯に巻取って筒
状フィルターを製造するに際し、巻取り前及び／又は巻
取り時あるいは巻取り後のいずれかの工程で熱処理を行
う。ここで熱処理とは、低融点成分の融点以上で高融点
成分の融点以下の温度で加熱することをいう。具体的に
は、メルトブロー法で得られる繊維径が順次変化した極
細の複合繊維ウエブは、熱処理により一旦不織布状とし
て貯蔵し、後に再度巻取り前及び／又は巻取り時あるい
は巻取り後のいずれかの工程で、加熱しながら巻芯に巻
とることにより本発明の筒状フィルターとすることがで
きる。また、紡糸後得られたウエブを引き続き巻取り前
及び／又は巻取り時あるいは巻取り後のいずれかの工程
で加熱しながら巻芯に卷き取って筒状フィルターとする
こともできる。このように熱処理することにより、ウエ
ブ内部で複合繊維同士の接点が、また卷き取られたウエ
ブの層間も複合繊維の低融点成分の融着により固定され
るので、耐圧強度の大きなフィルターを得ることができ
る。このような熱処理の効果は、巻芯への巻取り前及び
／又は巻取り時（巻取り点）の工程で行う方が顕著であ
る。つまり、フィルターの内層からの固定が順次行われ
るので、巻芯に巻取る際に生じる外圧に十分耐え得ると
同時に内層ほど繊維間の空隙が緻密になり易い。このた
め、前述の繊維径変化と相まって密度勾配が顕著とな
り、優れた耐圧性と微粒子の分級捕捉作用の相乗効果を
発揮する。一般にフィルターはそれを通過する流体の圧
力により圧縮され、繊維間空隙は目詰まりを生じろ過ラ
イフが短くなる。この傾向は流体の粘性が大きいほど顕
著になる。本発明は、前述の如く高融点成分と低融点成
分とからなる複合繊維を用い、熱処理により低融点成分
のみを繊維の接点で融着させているので、得られるフィ
ルターは、繊維接点の癒着で三次元構造を形成し、この
構造によって流体の圧力による空隙の目詰まりを防止す
る。このため、内層部に多孔質支持体や補強材などを必
要とせず、優れた耐圧性によりろ過精度が安定し、ろ過
ライフが長い。フィルターの構造において、係る複合繊
維の低融点成分のみを繊維の接点で融着させて三次元構
造を形成させるという構成が欠如すると、仮にフィルタ
ーの厚み方向に繊維径を変化させたとしても、比較例１
にみられるようにフィルターには繊維の融解と変形が生
じて目詰まりを生じ、ろ過ライフは短いものとなり、本
発明の効果は得られない。熱処理に用いる加熱源として
は、熱風、加圧蒸気、過熱蒸気、遠赤外線ヒータ等が用
いられるが、この内、特に遠赤外線ヒータは、ウエブを
乱すことなく均一な熱処理を行うことができ、好まし
い。熱処理の程度は、融着による繊維の固定と所望の空
隙密度が得られるよう、加熱帯域温度の高低、加熱帯域
の長さ、あるいは通過速度即ち加熱帯域での滞留時間の
長短等を適宜調節する。熱処理を終了したフィルターは
室温放置等により冷却した後、巻芯を抜き取り、適当な
長さに切断して筒状フィルターを得る。メルトブロー法
でウエブを製造する際にウエブ中に、あるいはウエブを
卷き取る際、本発明の効果を妨げない範囲において、ウ
エブ間に活性炭、ゼオライト、イオン交換樹脂等の微粒
子や、炭素繊維、殺菌性繊維、ガス吸着性繊維等の他の
機能性繊維を混入させることにより、微粒子の捕捉以外
の機能も併せて有するフィルターを製造することもでき
る。[0006] In the present invention, when the ultrafine composite fiber web obtained by depositing while changing the fiber diameter is wound on a winding core to manufacture a cylindrical filter, before and / or at the time of winding or winding. Heat treatment is performed in any of the subsequent steps. Here, the heat treatment means heating at a temperature not lower than the melting point of the low melting point component and not higher than the melting point of the high melting point component. Specifically, the ultrafine composite fiber web obtained by the melt-blowing method, in which the fiber diameter is sequentially changed, is once stored as a non-woven fabric by heat treatment, and is then either before and / or again before or after winding. In the step, the tubular filter of the present invention can be obtained by winding the core around the core while heating. Alternatively, the web obtained after spinning may be wound on a winding core while being heated in any step before winding and / or during winding or after winding to obtain a tubular filter. By such heat treatment, the contact point between the composite fibers inside the web is fixed by the fusion of the low melting point component of the composite fiber also between the layers of the wound web, and thus a filter having a large pressure resistance is obtained. be able to. The effect of such heat treatment is more remarkable when performed before and / or at the time of winding (winding point) on the winding core. That is, since the filter is fixed from the inner layer in order, it is possible to sufficiently withstand the external pressure generated when the filter is wound around the winding core, and at the same time, the inner layer tends to have denser voids between the fibers. For this reason, the density gradient becomes conspicuous in combination with the above-mentioned change in fiber diameter, and excellent synergistic effects of pressure resistance and fine particle classification and trapping action are exhibited. Generally, the filter is compressed by the pressure of the fluid passing through it, and the interfiber voids become clogged, which shortens the filtration life. This tendency becomes more remarkable as the viscosity of the fluid increases. The present invention uses the composite fiber composed of the high melting point component and the low melting point component as described above, and only the low melting point component is fused at the contact points of the fibers by heat treatment. A three-dimensional structure is formed, and this structure prevents clogging of voids due to fluid pressure. Therefore, a porous support or a reinforcing material is not required in the inner layer portion, the excellent pressure resistance stabilizes the filtration accuracy, and the filtration life is long. In the structure of the filter, if the structure in which only the low melting point component of the composite fiber is fused at the contact point of the fiber to form a three-dimensional structure, even if the fiber diameter is changed in the thickness direction of the filter, a comparison is made. Example 1
As can be seen from the above, the filter is melted and deformed to cause clogging, the filtration life becomes short, and the effect of the present invention cannot be obtained. As a heating source used for heat treatment, hot air, pressurized steam, superheated steam, far-infrared heater and the like are used. Among them, far-infrared heater can perform uniform heat treatment without disturbing the web, which is preferable. .. The degree of heat treatment is appropriately adjusted such that the temperature of the heating zone is high or low, the length of the heating zone, or the passing speed, that is, the length of the residence time in the heating zone, etc. is appropriately adjusted so that the fibers are fixed by fusion and the desired void density is obtained. .. The heat-treated filter is cooled by leaving it at room temperature or the like, then the core is removed and cut into an appropriate length to obtain a cylindrical filter. During production of the web by the melt-blowing method, in the web, or when winding the web, in the range that does not impair the effects of the present invention, fine particles such as activated carbon, zeolite, ion exchange resin between the web, carbon fiber, sterilization It is also possible to manufacture a filter that also has a function other than capturing fine particles by mixing other functional fibers such as a functional fiber and a gas adsorbing fiber.
【０００７】[0007]
【実施例】実施例および比較例により本発明を具体的に
説明する。なを、各例において用いた測定法を以下に示
す。 ろ過精度 ３０リットルの水を容れた水槽、ポンプ、及びろ過器か
らなる循環式ろ過試験装置を用いる。ろ過器のハウジン
グに試料フィルター１本を取り付け、水を毎分３０リッ
トルの流量で循環させながら、水槽にケーキ（カーボラ
ンダム ＃４０００）を５グラム添加する。ケーキ添加
より１分後に採取したろ過水１００ミリリットルを、
０．６ミクロン以上の粒子を捕集できるメンブレンフィ
ルターでろ過する。メンブレンフィルター上に捕集され
た粒子のサイズを粒度分布測定機で測定し、最も大きな
粒子のサイズ（最大流出径、ミクロン）を試料フィルタ
ーのろ過精度とする。 耐圧強度及びろ過ライフ 循環式ろ過試験装置に試料フィルター１本を取り付け、
水を毎分３０リットルの流量で循環させる。水槽に火山
灰土壌下層土粉末（平均粒径１２．９ミクロン、粒径が
１．０〜３０ミクロンの範囲内のものが９９重量％以
上）を２０グラム添加して循環ろ過を続け、水槽内の水
が透明になった時点でろ過前後の差圧を測定する。この
粉末の添加と差圧の測定の操作をフィルターが変形する
まで（又は差圧が１０ｋｇ／ｃｍ2になるまで）繰りか
えす。１回目の粉末添加からフィルターが変形するまで
の時間をろ過ライフとし、その時の差圧を耐圧強度とす
る。 平均繊維径 ウエブ、不織布、あるいはフィルターから４ｃｍ×４ｃ
ｍの薄片をそれぞれ１０枚切りとり、その走査型電子顕
微鏡による倍率５,０００倍の写真を用いて測定した１
００本の繊維径の平均値を示す。EXAMPLES The present invention will be specifically described with reference to Examples and Comparative Examples. The measurement methods used in each example are shown below. Filtration accuracy A circulation type filtration test device consisting of a water tank containing 30 liters of water, a pump, and a filter is used. Attach one sample filter to the filter housing and add 5 grams of cake (Carborundum # 4000) to the aquarium while circulating water at a rate of 30 liters per minute. 100 ml of filtered water collected 1 minute after adding the cake,
Filter with a membrane filter that can collect particles of 0.6 microns or more. The size of the particles collected on the membrane filter is measured with a particle size distribution analyzer, and the size of the largest particle (maximum outflow diameter, micron) is used as the filtration accuracy of the sample filter. Compressive strength and filtration life Attach one sample filter to the circulation type filtration test device,
Water is circulated at a flow rate of 30 liters per minute. Add 20 grams of volcanic ash soil lower layer soil powder (average particle size 12.9 microns, particle size within the range of 1.0 to 30 microns is 99% by weight or more) to the aquarium, continue circulating filtration, and in the aquarium, When the water becomes transparent, measure the differential pressure before and after filtration. The operation of adding the powder and measuring the differential pressure is repeated until the filter is deformed (or the differential pressure becomes 10 kg / cm 2 ). The time from the first powder addition to the deformation of the filter is defined as the filtration life, and the differential pressure at that time is defined as the pressure resistance. Average fiber diameter 4 cm x 4 c from web, non-woven fabric or filter
10 thin slices of m were cut and measured using a photograph of the scanning electron microscope at a magnification of 5,000. 1
The average value of the fiber diameter of 00 fibers is shown.
【０００８】（実施例１）孔径０．３ｍｍ、孔数５０１
個の紡糸口が一列に並んだメルトブロー用鞘芯型複合紡
糸口金を用い、芯成分としてメルトフローレート（ＭＦ
Ｒ：２３０℃）が２８０（ｇ／１０ｍｉｎ）で融点が１
６４℃のポリプロピレンを紡糸温度２９０℃で、鞘成分
としてメルトフローレート（ＭＦＲ：１９０℃）が１２
４（ｇ／１０ｍｉｎ）で融点が１２２℃の線状低密度ポ
リエチレンを紡糸温度２６０℃で、両成分を芯鞘複合比
５０／５０、総吐出量１２０ｇ／ｍｉｎで供給し、紡糸
口から押し出されたポリマーを３８０℃の加圧空気を用
いてネットコンベヤーに吹き付けることによりメルトブ
ロー法の極細複合繊維ウエブを得た。このウエブを、特
公昭５６ー４３１３９号公報に示されているように、ネ
ットコンベヤーで移送しながら遠赤外線ヒーターで１４
５℃に加熱し、外径３０ｍｍの円形ステンレスパイプに
卷き取って室温で放置冷却した。その後、ステンレスパ
イプを抜き取り、長さ２５０ｍｍに切断して、内径３０
ｍｍ、外径６０ｍｍ、長さ２５０ｍｍの円筒状フィルタ
ーを得た。なお、この卷き取りの間に、紡糸口金に供給
する空気の圧力を当初の３．２ｋｇ／ｃｍ2Ｇから末期
の０．６ｋｇ／ｃｍ2Ｇに連続的に徐々に減少させた。
ウエブからサンプリングした試料の測定によれば、この
フィルターの厚み方向の各部分の平均繊維径は、内側表
面で０．８ミクロン、内側から５ｍｍで１．８ミクロ
ン、内側から１０ｍｍでは２．７ミクロン、外側表面で
７．６ミクロンであった。このフィルターは、繊維同士
がその接点で低融点成分のポリエチレンの融着により互
いに接着されて三次元構造を形成しており、机に打ち付
けても変形しない硬いものであった。このフィルターの
ろ過精度は０．９ミクロン、耐圧強度６．３ｋｇ／ｃｍ
2、ろ過ライフ３０分であり、ろ過初期におけるろ液の
泡立ちは全く観察されなかった。(Example 1) Hole diameter 0.3 mm, number of holes 501
Using a sheath-core type composite spinneret for melt blowing, in which individual spinnerets are arranged in a line, the melt flow rate (MF) is used as the core component.
R: 230 ° C) is 280 (g / 10min) and the melting point is 1
Polypropylene at 64 ° C has a spinning temperature of 290 ° C and a melt flow rate (MFR: 190 ° C) of 12 as a sheath component.
4 (g / 10 min) and a melting point of 122 ° C. linear low-density polyethylene at a spinning temperature of 260 ° C., both components were fed at a core-sheath composite ratio of 50/50 and a total discharge rate of 120 g / min, and extruded from the spinning port. The polymer was blown onto a net conveyor using pressurized air at 380 ° C. to obtain a melt-blown ultrafine composite fiber web. As shown in Japanese Patent Publication No. 56-43139, this web is transferred by a net conveyor while being heated by a far-infrared heater.
It was heated to 5 ° C., rolled up in a circular stainless pipe having an outer diameter of 30 mm, and left standing to cool at room temperature. After that, pull out the stainless steel pipe and cut it to a length of 250 mm,
A cylindrical filter having a diameter of 60 mm, an outer diameter of 60 mm and a length of 250 mm was obtained. During the winding, the pressure of the air supplied to the spinneret was gradually reduced from the initial 3.2 kg / cm 2 G to 0.6 kg / cm 2 G in the final stage.
According to the measurement of the sample sampled from the web, the average fiber diameter of each part in the thickness direction of the filter is 0.8 micron on the inner surface, 1.8 micron on the inner side of 5 mm, and 2.7 micron on the inner side of 10 mm. , 7.6 microns on the outer surface. In this filter, fibers were adhered to each other at their contact points by fusion bonding of polyethylene having a low melting point component to form a three-dimensional structure, and were hard so that they would not be deformed even when they were struck on a desk. The filtration accuracy of this filter is 0.9 micron, and the pressure resistance is 6.3 kg / cm.
2 , the filtration life was 30 minutes, and no bubbling of the filtrate was observed at the initial stage of filtration.
【０００９】（実施例２）実施例１と同じ紡糸装置を用
い、芯成分として固有粘度０．６０、融点２５３℃のポ
リエチレンテレフタレートを紡糸温度２８５℃で、鞘成
分として固有粘度０．５８、融点１６０℃のエチレング
リコールテレフタレート・イソフタレート共重合体を紡
糸温度２７０℃で,両成分を芯鞘複合比５０／５０、総
吐出量１２０ｇ／ｍｉｎで供給し、紡糸口から押し出さ
れたポリマーを３５０℃の加圧空気を用いてネットコン
ベヤーに吹き付けることによりメルトブロー法の極細複
合繊維ウエブを得た。このウエブを、実施例１と同様
に、ネットコンベヤーで移送しながら遠赤外線ヒーター
で１７０℃に加熱し、外径３０ｍｍの円形ステンレスパ
イプに卷き取って室温で放置冷却した。その後、ステン
レスパイプを抜き取り、長さ２５０ｍｍに切断して、内
径３０ｍｍ、外径６０ｍｍ、長さ２５０ｍｍの円筒状フ
ィルターを得た。なお、この卷き取りの間に、紡糸口金
に供給する空気の圧力を当初の２．８ｋｇ／ｃｍ2Ｇか
ら末期の０．４ｋｇ／ｃｍ2Ｇに連続的に徐々に減少さ
せた。このフィルターの厚み方向の各部分の平均繊維径
は、内側表面で１．８ミクロン、内側から５ｍｍで３．
９ミクロン、内側から１０ｍｍでは６．８ミクロン、外
側表面で９．２ミクロンであり、繊維同士は接点で低融
点成分の融着により互いに接着されて三次元構造を形成
していた。このフィルターのろ過精度は１．６ミクロ
ン、耐圧強度７．４ｋｇ／ｃｍ2、ろ過ライフ３６分で
あり、ろ過初期におけるろ液の泡立ちは全く観察されな
かった。(Example 2) Using the same spinning device as in Example 1, polyethylene terephthalate having an intrinsic viscosity of 0.60 and a melting point of 253 ° C. as a core component at a spinning temperature of 285 ° C. and an intrinsic viscosity of 0.58 and a melting point as a sheath component. An ethylene glycol terephthalate / isophthalate copolymer at 160 ° C was fed at a spinning temperature of 270 ° C, both components were fed at a core-sheath composite ratio of 50/50 and a total discharge rate of 120 g / min, and the polymer extruded from the spinning port was 350 ° C. An ultrafine composite fiber web obtained by the melt-blowing method was obtained by blowing the compressed air on the net conveyor. This web was transferred to a net conveyor, heated to 170 ° C. with a far infrared heater, rolled up in a circular stainless steel pipe having an outer diameter of 30 mm, and allowed to cool at room temperature in the same manner as in Example 1. Then, the stainless pipe was pulled out and cut into a length of 250 mm to obtain a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 60 mm and a length of 250 mm. During the winding, the pressure of the air supplied to the spinneret was gradually reduced from the initial 2.8 kg / cm 2 G to the final 0.4 kg / cm 2 G. The average fiber diameter of each part in the thickness direction of this filter was 1.8 microns on the inner surface and 5 mm from the inner side.
It was 9 microns, 6.8 microns at 10 mm from the inside, and 9.2 microns at the outer surface, and the fibers were bonded to each other at the contact point by fusion of the low melting point component to form a three-dimensional structure. The filtration accuracy of this filter was 1.6 μm, the pressure resistance was 7.4 kg / cm 2 , and the filtration life was 36 minutes. No bubbling of the filtrate was observed at the initial stage of filtration.
【００１０】（実施例３）孔径０．３ｍｍ、孔数５０１
個の紡糸口が一列に並んだメルトブロー用鞘芯型複合紡
糸口金を用い、芯成分としてメルトフローレート（ＭＦ
Ｒ：２３０℃）が２０４（ｇ／１０ｍｉｎ）で融点が１
６５℃のポリプロピレンを紡糸温度２８０℃で、鞘成分
としてメルトフローレート（ＭＦＲ：１９０℃）が１２
４（ｇ／１０ｍｉｎ）で融点が１２２℃の線状低密度ポ
リエチレンを紡糸温度２４０℃で、両成分を芯鞘複合比
５０／５０とし、総吐出量を当初１２０ｇ／ｍｉｎで供
給し、途中から１６０ｇ／ｍｉｎに増加させた。紡糸口
から押し出されたポリマーを３６０℃、１．９ｋｇ／ｃ
ｍ2Ｇの加圧空気を用いてネットコンベヤーに吹き付け
ることによりメルトブロー法の極細複合繊維ウエブを得
た。このウエブを、特公昭５６ー４３１３９号公報に示
されているように、引き続きネットコンベヤーで移送し
ながら遠赤外線ヒーターで１４５℃に加熱し、外径３０
ｍｍの円形ステンレスパイプに卷き取って室温で放置冷
却した。その後、ステンレスパイプを抜き取り、長さ２
５０ｍｍに切断して、内径３０ｍｍ、外径６０ｍｍ、長
さ２５０ｍｍの円筒状フィルターを得た。このフィルタ
ーの各部分の平均繊維径は、内側から９ｍｍまでは１．
８ミクロン、内側から９ｍｍ以上では２．７ミクロンで
あり、繊維同士は接点で低融点成分の融着により互いに
接着されて三次元構造を形成していた。このフィルター
のろ過精度は２．６ミクロン、耐圧強度６．１ｋｇ／ｃ
ｍ2、ろ過ライフ３０分であり、ろ過初期におけるろ液
の泡立ちは全く観察されなかった。(Embodiment 3) Hole diameter 0.3 mm, hole number 501
Using a sheath-core type composite spinneret for melt blowing, in which individual spinnerets are arranged in a line, the melt flow rate (MF) is used as the core component.
R: 230 ° C) is 204 (g / 10min) and the melting point is 1
Polypropylene of 65 ° C has a spinning temperature of 280 ° C and a melt flow rate (MFR: 190 ° C) of 12 as a sheath component.
4 (g / 10 min) and a melting point of 122 ° C. linear low density polyethylene at a spinning temperature of 240 ° C., both components at a core-sheath composite ratio of 50/50, and the total discharge amount was initially supplied at 120 g / min. It was increased to 160 g / min. The polymer extruded from the spinneret is 360 ° C., 1.9 kg / c
A melt-blown ultrafine composite fiber web was obtained by blowing it onto a net conveyor using pressurized air of m 2 G. As shown in Japanese Patent Publication No. 56-43139, this web is continuously heated by a far infrared heater while being transferred by a net conveyor to an outer diameter of 30.
It was wound on a circular stainless steel pipe of mm and left to cool at room temperature. After that, pull out the stainless steel pipe, length 2
It was cut into 50 mm to obtain a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 60 mm and a length of 250 mm. The average fiber diameter of each part of this filter is 1.
It was 8 microns and 2.7 microns at 9 mm or more from the inside, and the fibers were bonded to each other at the contact point by fusion of the low melting point components to form a three-dimensional structure. The filtration accuracy of this filter is 2.6 microns, and the pressure resistance is 6.1 kg / c.
m 2 , the filtration life was 30 minutes, and no bubbling of the filtrate was observed at the initial stage of filtration.
【００１１】（実施例４）孔径０．３ｍｍ、孔数５０１
個の紡糸口が一列に並んだメルトブロー用鞘芯型複合紡
糸口金を用い、芯成分としてメルトフローレート（ＭＦ
Ｒ：２３０℃）が２０４（ｇ／１０ｍｉｎ）で融点が１
６５℃のポリプロピレンを紡糸温度２８０℃で、鞘成分
としてメルトフローレート（ＭＦＲ：１９０℃）が１２
４（ｇ／１０ｍｉｎ）で融点が１２２℃の線状低密度ポ
リエチレンを紡糸温度２４０℃で、両成分を芯鞘複合比
７０／３０とし、総吐出量を１２０ｇ／ｍｉｎで供給
し、紡糸口から押し出されたポリマーを３６０℃、１．
９ｋｇ／ｃｍ2Ｇの加圧空気を用いてネットコンベヤー
に吹き付けることにより、平均繊維径２．４ミクロンの
メルトブロー法の極細複合繊維ウエブを得た。このウエ
ブを遠赤外線ヒーターで１４０℃に加熱する加熱槽を通
して卷き取り、平均繊維径２．４ミクロンの不織布（不
織布Ａ）を得た。総吐出量を１６０ｇ／ｍｉｎとした以
外は上記と同様にして、平均繊維径８．８ミクロンの不
織布（不織布Ｂ）を得た。不織布Ａを遠赤外線ヒーター
で１４５℃に加熱しながら外径３０ｍｍの円形ステンレ
スパイプに厚み１０ｍｍまで卷き取り、引き続き不織布
Ｂを同様に加熱しながら厚み５ｍｍだけ卷き取って、室
温で放置冷却した。その後ステンレスパイプを抜き取
り、内径３０ｍｍ、外径６０ｍｍ、長さ２５０ｍｍの円
筒状フィルターを得た。このフィルターも繊維同士が接
点で低融点成分の融着により互いに接着されて三次元構
造を形成した硬いもので、ろ過精度は２．４ミクロン、
耐圧強度７．７ｋｇ／ｃｍ2、ろ過ライフ３０分であ
り、ろ過初期におけるろ液の泡立ちは全く観察されなか
った。(Embodiment 4) Hole diameter 0.3 mm, hole number 501
Using a sheath-core type composite spinneret for melt blowing, in which individual spinnerets are arranged in a line, the melt flow rate (MF) is used as the core component.
R: 230 ° C) is 204 (g / 10min) and the melting point is 1
Polypropylene of 65 ° C has a spinning temperature of 280 ° C and a melt flow rate (MFR: 190 ° C) of 12 as a sheath component.
4 (g / 10 min) and a melting point of 122 ° C. linear low-density polyethylene at a spinning temperature of 240 ° C., both components at a core-sheath composite ratio of 70/30, and a total discharge rate of 120 g / min. The extruded polymer was cast at 360 ° C.
The melt blown ultrafine composite fiber web having an average fiber diameter of 2.4 microns was obtained by blowing it onto a net conveyor using pressurized air of 9 kg / cm 2 G. This web was wound up through a heating tank heated to 140 ° C. with a far infrared heater to obtain a nonwoven fabric (nonwoven fabric A) having an average fiber diameter of 2.4 microns. A nonwoven fabric (nonwoven fabric B) having an average fiber diameter of 8.8 microns was obtained in the same manner as above except that the total discharge amount was 160 g / min. Nonwoven fabric A was wound up to a thickness of 10 mm on a circular stainless steel pipe having an outer diameter of 30 mm while being heated to 145 ° C. with a far infrared heater, and subsequently, nonwoven fabric B was wound up to a thickness of 5 mm while being similarly heated and left to cool at room temperature. .. Then, the stainless pipe was pulled out to obtain a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 60 mm and a length of 250 mm. This filter is also a hard one in which fibers are bonded to each other at the contact point by fusion of low melting point components to form a three-dimensional structure, and the filtration accuracy is 2.4 microns,
The pressure resistance was 7.7 kg / cm 2 , the filtration life was 30 minutes, and no bubbling of the filtrate was observed at the initial stage of filtration.
【００１２】（実施例５）孔径０．３ｍｍ、孔数５０１
個の紡糸口が一列に並んだメルトブロー用並列型複合紡
糸口金を用い、第１成分としてメルトフローレート（Ｍ
ＦＲ：２３０℃）が２８０（ｇ／１０ｍｉｎ）で融点が
１６４℃のポリプロピレンを紡糸温度２９０℃で、第２
成分としてメルトフローレート（ＭＦＲ：１９０℃）が
１２４（ｇ／１０ｍｉｎ）で融点が１２２℃の線状低密
度ポリエチレンを紡糸温度２６０℃で、両成分を複合比
６０／４０、総吐出量１２０ｇ／ｍｉｎで供給し、紡糸
口から押し出されたポリマーを３８０℃の加圧空気を用
いてネットコンベヤーに吹き付けることによりメルトブ
ロー法の極細複合繊維ウエブを得た。このウエブを、特
公昭５６ー４３１３９号公報に示されているように、ネ
ットコンベヤーで移送しながら遠赤外線ヒーターで１４
５℃に加熱し、外径３０ｍｍの円形ステンレスパイプに
卷き取って室温で放置冷却した。その後、ステンレスパ
イプを抜き取り、長さ２５０ｍｍに切断して、内径３０
ｍｍ、外径６０ｍｍ、長さ２５０ｍｍの円筒状フィルタ
ーを得た。なお、この卷き取りの間に、紡糸口金に供給
する空気の圧力を当初の３．２ｋｇ／ｃｍ2Ｇから末期
の０．６ｋｇ／ｃｍ2Ｇに連続的に徐々に減少させた。
ウエブからサンプリングした試料の測定によれば、この
フィルターの厚み方向の各部分の平均繊維径は、内側表
面で０．９ミクロン、内側から５ｍｍで１．６ミクロ
ン、内側から１０ｍｍでは２．８ミクロン、外側表面で
７．３ミクロンであった。このフィルターは、繊維同士
がその接点で低融点成分のポリエチレンの融着により互
いに接着されて三次元構造を形成しており、机に打ち付
けても変形しない硬いものであった。このフィルターの
ろ過精度は０．９ミクロン、耐圧強度６．１ｋｇ／ｃｍ
2、ろ過ライフ２９分であり、ろ過初期におけるろ液の
泡立ちは全く観察されなかった。(Embodiment 5) Hole diameter 0.3 mm, hole number 501
A parallel type composite spinneret for melt blowing, in which individual spinnerets are arranged in a line, is used, and the melt flow rate (M
FR: 230 ° C) is 280 (g / 10 min) and the melting point is 164 ° C.
As a component, a linear low-density polyethylene having a melt flow rate (MFR: 190 ° C.) of 124 (g / 10 min) and a melting point of 122 ° C. was used at a spinning temperature of 260 ° C., a composite ratio of both components was 60/40, and a total discharge amount was 120 g / The polymer that was supplied at a rate of min and extruded from the spinneret was blown onto a net conveyor using pressurized air at 380 ° C. to obtain a melt-blown ultrafine composite fiber web. As shown in Japanese Patent Publication No. 56-43139, this web is transferred by a net conveyor while being heated by a far-infrared heater.
It was heated to 5 ° C., rolled up in a circular stainless pipe having an outer diameter of 30 mm, and left standing to cool at room temperature. After that, pull out the stainless steel pipe and cut it to a length of 250 mm,
A cylindrical filter having a diameter of 60 mm, an outer diameter of 60 mm and a length of 250 mm was obtained. During the winding, the pressure of the air supplied to the spinneret was gradually reduced from the initial 3.2 kg / cm 2 G to 0.6 kg / cm 2 G in the final stage.
According to the measurement of the sample sampled from the web, the average fiber diameter of each part in the thickness direction of this filter is 0.9 micron at the inner surface, 1.6 micron at 5 mm from the inner side, and 2.8 micron at 10 mm from the inner side. , 7.3 microns on the outer surface. In this filter, fibers were adhered to each other at their contact points by fusion bonding of polyethylene having a low melting point component to form a three-dimensional structure, and were hard so that they would not be deformed even when they were struck on a desk. The filtration accuracy of this filter is 0.9 micron, and the pressure resistance is 6.1 kg / cm.
2 , the filtration life was 29 minutes, and no bubbling of the filtrate was observed at the initial stage of filtration.
【００１３】（実施例６）実施例５と同様の条件で紡糸
して得られたメルトブロー法の極細複合繊維ウエブを、
ネットコンベヤーで移送しながら遠赤外線ヒーターで１
４５℃に加熱し、外周の各辺が１５ｍｍの正６角形のス
テンレスパイプに卷き取って室温で放置冷却した。その
後、ステンレスパイプを抜き取り、長さ２５０ｍｍに切
断しての円筒状フィルターを得た。このフィルターは、
外径が最大のところで６０ｍｍ、最小のところで５２ｍ
ｍの概ね円形に近いものであった。なお、この卷き取り
の間に、紡糸口金に供給する空気の圧力を当初の３．２
ｋｇ／ｃｍ2Ｇから末期の０．６ｋｇ／ｃｍ2Ｇに連続的
に徐々に減少させた。このフィルターは、繊維同士がそ
の接点で低融点成分のポリエチレンの融着により互いに
接着されて三次元構造を形成しており、机に打ち付けて
も変形しない硬いものであった。このフィルターのろ過
精度は０．９ミクロン、耐圧強度５．７ｋｇ／ｃｍ2、
ろ過ライフ３０分であり、ろ過初期におけるろ液の泡立
ちは全く観察されなかった。 （実施例７）孔径０．３ｍｍ、孔数５０１個の紡糸口が
一列に並んだメルトブロー用鞘芯型複合紡糸口金を用
い、芯成分としてメルトフローレート（ＭＦＲ：２３０
℃）が１８０（ｇ／１０ｍｉｎ）で融点が１６５℃のポ
リプロピレンを紡糸温度２８０℃で、鞘成分としてメル
トフローレート（ＭＦＲ：１９０℃）が１３５（ｇ／１
０ｍｉｎ）で融点が１３８℃のプロピレン・エチレン・
ブテン−１ランダム共重合体を紡糸温度３００℃で、両
成分を芯鞘複合比５０／５０、当初の総吐出量は１２０
ｇ／ｍｉｎで途中から１６０ｇ／ｍｉｎに増加して供給
した。多孔質パイプでできた巻芯をパイプ内を吸引排気
しながら、周速１０ｍ／ｍｉｎで回転させ、紡糸口から
押し出されたポリマーを温度３６０℃、圧力１．９ｋｇ
／ｃｍ2の加圧空気を用いてこの巻芯に吹き付けること
により、メルトブロー法の極細複合繊維ウエブを巻芯の
周囲に堆積させ巻取った。巻取り終了後吸引と回転を続
けながら、遠赤外線ヒーターで雰囲気温度を１４０℃設
定した加熱箱内で巻芯ごとウエブを加熱し、引き続き室
温で放置冷却した。その後、巻芯を抜き取り、長さ２５
０ｍｍに切断して、内径３０ｍｍ、外径６０ｍｍ、長さ
２５０ｍｍの円筒状フィルターを得た。ウエブからサン
プリングした試料の測定によれば、このフィルターの厚
み方向の各部分の平均繊維径は、内側から９ｍｍまでは
１．６ミクロン、内側から９ｍｍ以上では２．８ミクロ
ンであり、繊維同士はその接点で低融点成分の融着によ
り互いに接着されて三次元構造を形成しており、机に打
ち付けても変形しない硬いものであった。このフィルタ
ーのろ過精度は２．５ミクロン、耐圧強度６．８ｋｇ／
ｃｍ2、ろ過ライフ２７分であり、ろ過初期におけるろ
液の泡立ちは全く観察されなかった。Example 6 A melt-blown ultrafine composite fiber web obtained by spinning under the same conditions as in Example 5 was used.
Far-infrared heater 1 while transferring by net conveyor
It was heated to 45 ° C., wound on a regular hexagonal stainless pipe having 15 mm on each side of the outer circumference, and left standing to cool at room temperature. Then, the stainless pipe was pulled out and cut into a length of 250 mm to obtain a cylindrical filter. This filter is
60 mm at maximum outer diameter, 52 m at minimum
It was almost circular in m. During the winding operation, the pressure of the air supplied to the spinneret was set to 3.2.
From kg / cm 2 G to 0.6 kg / cm 2 G with end-stage continuously gradually reduced. In this filter, fibers were adhered to each other at their contact points by fusion bonding of polyethylene having a low melting point component to form a three-dimensional structure, and were hard so that they would not be deformed even when they were struck on a desk. The filtration accuracy of this filter is 0.9 micron, pressure resistance is 5.7 kg / cm 2 ,
The filtration life was 30 minutes, and no bubbling of the filtrate was observed at the initial stage of filtration. (Example 7) A sheath-core type composite spinneret for melt blowing in which a spinneret having a hole diameter of 0.3 mm and 501 holes is arranged in a line is used, and a melt flow rate (MFR: 230) is used as a core component.
Polypropylene having a melting point of 165 ° C and a melt flow rate (MFR: 190 ° C) of 135 (g / 1) as a sheath component.
Propylene / ethylene / melting point 138 ° C at 0 min)
The butene-1 random copolymer was spun at a temperature of 300 ° C., both components were mixed at a core / sheath ratio of 50/50, and the initial total discharge amount was 120.
The supply was increased from midway to 160 g / min at g / min. The core extruded from the porous pipe was rotated at a peripheral speed of 10 m / min while suctioning and exhausting the inside of the pipe, and the polymer extruded from the spinneret was heated at a temperature of 360 ° C. and a pressure of 1.9 kg.
The melt-blown ultrafine composite fiber web was deposited and wound around the winding core by blowing the same onto the winding core using pressurized air of / cm 2 . After the completion of winding, while continuing suction and rotation, the web was heated together with the winding core in a heating box in which the ambient temperature was set to 140 ° C. with a far infrared heater, and subsequently left to cool at room temperature. After that, pull out the core and length 25
It was cut into 0 mm to obtain a cylindrical filter having an inner diameter of 30 mm, an outer diameter of 60 mm and a length of 250 mm. According to the measurement of the sample sampled from the web, the average fiber diameter of each part in the thickness direction of this filter is 1.6 microns from the inside to 9 mm, and 2.8 microns from the inside to 9 mm or more. The contact points were adhered to each other by fusion of low-melting point components to form a three-dimensional structure, which was a hard material that did not deform even when it was struck on a desk. The filtration accuracy of this filter is 2.5 microns and the pressure resistance is 6.8 kg /
cm 2 , the filtration life was 27 minutes, and no bubbling of the filtrate was observed at the initial stage of filtration.
【００１４】（比較例１）孔径０．３ｍｍ、孔数５０１
個の紡糸口が一列に並んだメルトブロー用紡糸口金を用
い、てメルトフローレート（ＭＦＲ：２３０℃）が１８
０（ｇ／１０ｍｉｎ）で融点が１６４℃のポリプロピレ
ンを紡糸温度２８０℃で、吐出量を１２０ｇ／ｍｉｎで
供給し、紡糸口から押し出されたポリマーを３８０℃の
加圧空気を用いてネットコンベヤーに吹き付けることに
よりメルトブロー法の極細繊維ウエブを得た。このウエ
ブを、実施例１と同様に、ネットコンベヤーで移送しな
がら遠赤外線ヒーターで１９０℃に加熱し、外径３０ｍ
ｍの円形ステンレスパイプに卷き取って室温で放置冷却
し、ステンレスパイプを抜き取り、長さ２５０ｍｍに切
断して、内径３０ｍｍ、外径６０ｍｍ、長さ２５０ｍｍ
の円筒状フィルターを得た。なお、この卷き取りの間
に、紡糸口金に供給する空気の圧力を当初の３．２ｋｇ
／ｃｍ2Ｇから末期の０．６ｋｇ／ｃｍ2Ｇに連続的に徐
々に減少させた。ウエブで測定したこのフィルターの各
部分の平均繊維径は、内側表面で３．４ミクロン、内側
から５ｍｍで８．２ミクロン、内側から１０ｍｍでは１
５ミクロン、外側表面で２２ミクロンであったが、フィ
ルター自身は繊維の融解と変形による目詰まりがみられ
る非常に硬いものであった。このフィルターは、ろ過初
期におけるろ液の泡立ちは全く観察されず、ろ過精度は
３．２ミクロン、耐圧強度６．５ｋｇ／ｃｍ2であった
が、ろ過ライフは５分と極めて短いものであった。 （比較例２）加圧空気の圧力を３．２ｋｇ／ｃｍ2Ｇに
固定した以外は実施例１と同じ条件で、平均繊維径が厚
み方向に対して一様に０．９ミクロンの複合繊維からな
り、内径３０ｍｍ、外径６０ｍｍ、長さ２５０ｍｍの円
筒状フィルターを作製した。このフィルターのろ過精度
は０．９ミクロン、耐圧強度は６．５ｋｇ／ｃｍ2であ
ったが、ろ過ライフは１０分と短いものであった。 （比較例３）加圧空気の圧力を０．６ｋｇ／ｃｍ2Ｇに
固定した以外は実施例１と同じ条件で、平均繊維径が厚
み方向に対して一様に７．３ミクロンの複合繊維からな
り、内径３０ｍｍ、外径６０ｍｍ、長さ２５０ｍｍの円
筒状フィルターを作製した。このフィルターの耐圧強度
は６．０５ｋｇ／ｃｍ2、ろ過ライフは５０分であった
が、ろ過精度は７．０ミクロンと劣ったものであった。 （参考例１）メルトブロー法で紡糸された平均繊維径
１．３ミクロンのポリプロピレンウエブを、補強用の多
孔性のプラスチック筒に卷き取って作られた市販のフイ
ルター（内径３０ｍｍ、外径６０ｍｍ、長さ２５０ｍ
ｍ）の性能を試験した。このフィルターは、ろ過初期に
おけるろ液の泡立ちは全く観察されなかったが、平均繊
維径が小さいにもかかわらずろ過精度は９．０ミクロン
と劣り、耐圧強度は１．８ｋｇ／ｃｍ2、ろ過ライフも
８分と短いものであった。これは、繊維同士は単に摩擦
力によって固定されているので、水圧によりフィルター
内部の細孔が目開きしてろ過精度が低下したり、フィル
ター自身が変形することによると考えられる。(Comparative Example 1) Hole diameter 0.3 mm, number of holes 501
A melt flow rate (MFR: 230 ° C.) of 18 is obtained by using a melt-blowing spinneret in which individual spinnerets are aligned.
Polypropylene with a melting point of 164 ° C. at 0 (g / 10 min) was supplied at a spinning temperature of 280 ° C. and a discharge rate of 120 g / min, and the polymer extruded from the spinneret was transferred to a net conveyor using pressurized air at 380 ° C. By spraying, a melt-blown ultrafine fiber web was obtained. This web was heated to 190 ° C. with a far infrared heater while being transferred on a net conveyor in the same manner as in Example 1, and the outer diameter was 30 m.
It is rolled up in a circular stainless steel pipe of m and left to cool at room temperature, the stainless steel pipe is pulled out and cut into a length of 250 mm, an inner diameter of 30 mm, an outer diameter of 60 mm, and a length of 250 mm.
To obtain a cylindrical filter. During this winding operation, the pressure of the air supplied to the spinneret was 3.2 kg at the beginning.
/ Cm 2 G to 0.6 kg / cm 2 G in the final stage continuously and gradually. The average fiber diameter of each part of this filter, measured on the web, is 3.4 microns on the inside surface, 8.2 microns on 5 mm from the inside and 1 on 10 mm from the inside.
It was 5 microns and 22 microns on the outer surface, but the filter itself was very hard with clogging due to melting and deformation of the fibers. In this filter, no bubbling of the filtrate was observed at the initial stage of filtration, the filtration accuracy was 3.2 μm and the pressure resistance was 6.5 kg / cm 2 , but the filtration life was extremely short at 5 minutes. .. (Comparative Example 2) A composite fiber having an average fiber diameter of 0.9 micron uniformly in the thickness direction under the same conditions as in Example 1 except that the pressure of pressurized air was fixed at 3.2 kg / cm 2 G. A cylindrical filter having an inner diameter of 30 mm, an outer diameter of 60 mm and a length of 250 mm was manufactured. The filtration accuracy of this filter was 0.9 micron and the pressure resistance was 6.5 kg / cm 2 , but the filtration life was as short as 10 minutes. (Comparative Example 3) A composite fiber having an average fiber diameter of 7.3 microns uniformly in the thickness direction under the same conditions as in Example 1 except that the pressure of pressurized air was fixed at 0.6 kg / cm 2 G. A cylindrical filter having an inner diameter of 30 mm, an outer diameter of 60 mm and a length of 250 mm was manufactured. The compressive strength of this filter was 6.05 kg / cm 2 , and the filtration life was 50 minutes, but the filtration accuracy was inferior at 7.0 microns. (Reference Example 1) A commercially available filter (inner diameter: 30 mm, outer diameter: 60 mm, manufactured by winding a polypropylene web having an average fiber diameter of 1.3 microns spun by a melt blow method into a reinforcing porous plastic cylinder. 250m long
The performance of m) was tested. In this filter, no bubbling of the filtrate was observed at the initial stage of filtration, but despite the small average fiber diameter, the filtration accuracy was inferior at 9.0 microns, the pressure resistance was 1.8 kg / cm 2 , and the filtration life was It was as short as 8 minutes. It is considered that this is because the fibers are simply fixed by the frictional force, and thus the pores inside the filter are opened by water pressure to lower the filtration accuracy, or the filter itself is deformed.
【００１５】[0015]
【発明の効果】本発明のフィルターは、メルトブロー法
による極細複合繊維を用いて、かつ、フィルターの厚み
方向に繊維径を変えることによりろ過層の内外で空隙の
大きさに勾配をつけてあるので、ろ過精度が良いうえに
ろ過ライフが長い。また、繊維同士が接点で低融点成分
の融着により互いに接着されて三次元構造を形成してい
るのでフィルター自身が固く、補強材を必要とせず、高
圧ろ過であってもフィルターの細孔が目開きしないので
耐圧性に優れ精密ろ過が安定して行える。さらに、繊維
加工用の油剤を使用しないので、ろ液が油剤で汚染され
ることがなく、食品加工分野や電子機器分野にも安全に
使用できる。INDUSTRIAL APPLICABILITY The filter of the present invention uses ultrafine composite fibers produced by the melt-blowing method and has a gradient in the size of voids inside and outside the filtration layer by changing the fiber diameter in the thickness direction of the filter. The filtration accuracy is good and the filtration life is long. In addition, since the fibers are bonded to each other at the contact point by fusing the low melting point components to form a three-dimensional structure, the filter itself is solid, no reinforcing material is required, and the pores of the filter are small even in high-pressure filtration. Since it does not open, it has excellent pressure resistance and can perform stable microfiltration. Further, since the oil agent for fiber processing is not used, the filtrate is not contaminated with the oil agent and can be safely used in the food processing field and the electronic device field.
Claims (2)
分と低融点成分とからなる極細の複合繊維で形成された
筒状フィルターであって、該複合繊維はフィルターの厚
み方向に対して繊維径を順次細く変化させて巻き取られ
ており、かつ複合繊維の接点が低融点成分により融着し
ていることを特徴とする筒状フィルター。1. A tubular filter formed of ultrafine composite fibers composed of a high melting point component and a low melting point component obtained by a melt blow method, wherein the composite fiber has a fiber diameter in the thickness direction of the filter. A tubular filter characterized in that it is wound in such a manner that it is gradually changed into fine particles, and that the contact points of the composite fiber are fused by a low melting point component.
成分と低融点成分とを複合メルトブロー紡糸しながら、
順次繊維径を変化させて堆積して得られた極細複合繊維
ウエブを巻芯に巻取るに際し、巻取り前及び／又は巻取
り時あるいは巻取り後のいずれかの工程で、前記低融点
成分の融点以上で高融点成分の融点以下の温度で熱処理
し、その後巻芯を抜き取ることを特徴とする筒状フィル
ターの製造方法。2. A composite melt-blow spinning of a high-melting point component and a low-melting point component made of a fiber-forming thermoplastic resin,
When winding the ultrafine composite fiber web obtained by successively changing the fiber diameter and winding the fiber, the low melting point component of the low melting point component may be added before winding and / or during winding or after winding. A method for producing a tubular filter, which comprises heat-treating at a temperature not lower than the melting point and not higher than the melting point of a high-melting point component, and then removing the core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW082103374A TW211592B (en) | 1991-03-15 | 1993-04-30 |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3-75796 | 1991-03-15 | ||
| JP7579691 | 1991-03-15 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0596110A true JPH0596110A (en) | 1993-04-20 |
| JPH0798131B2 JPH0798131B2 (en) | 1995-10-25 |
Family
ID=13586527
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4048105A Expired - Lifetime JPH0798131B2 (en) | 1991-03-15 | 1992-02-04 | Cylindrical filter and manufacturing method thereof |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH0798131B2 (en) |
| TW (1) | TW211592B (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5665235A (en) * | 1995-05-09 | 1997-09-09 | Pall Corporation | Supported fibrous web assembly |
| JP2002542009A (en) * | 1999-04-21 | 2002-12-10 | オズモニクス， インコーポレイテッド | Nonwoven depth filter component and method of making same |
| JP2006297388A (en) * | 2005-04-19 | 2006-11-02 | Howard William Morgan | Filter element having variable-density side wall |
| JP2006297389A (en) * | 2005-04-19 | 2006-11-02 | Howard William Morgan | Filter element having variable-density side wall |
| WO2007018165A1 (en) * | 2005-08-10 | 2007-02-15 | Toray Industries, Inc. | Sponge-like structural body or powder, and process for production thereof |
| JP2007077563A (en) * | 2005-08-19 | 2007-03-29 | Toray Ind Inc | Powder comprising ultrafine fiber and method for producing the same |
| JP2009095787A (en) * | 2007-10-18 | 2009-05-07 | Fujifilm Corp | Agent and method for removing harmful substance |
| JP2009219952A (en) * | 2008-03-13 | 2009-10-01 | Kurita Water Ind Ltd | Fiber for filter, bobbin type filter, and water treatment method |
| WO2010005060A1 (en) * | 2008-07-10 | 2010-01-14 | 株式会社ニフコ | Fuel filter |
| JP2014240537A (en) * | 2013-05-17 | 2014-12-25 | アンビック株式会社 | Filament nonwoven fabric, oil absorber obtained by using the same, and method for producing filament nonwoven fabric |
| JP2019537503A (en) * | 2016-10-06 | 2019-12-26 | グロッツ−ベッケルト・カーゲー | Method for producing pleated textiles having electrostatically charged fibers and pleated textiles |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60216818A (en) * | 1984-01-06 | 1985-10-30 | ポ−ル・コ−ポレ−シヨン | Cylindrical fibrous structure and its production |
| JPH0351310A (en) * | 1989-07-15 | 1991-03-05 | James River Corp:The | Melt-blown polymer dispersion |
-
1992
- 1992-02-04 JP JP4048105A patent/JPH0798131B2/en not_active Expired - Lifetime
-
1993
- 1993-04-30 TW TW082103374A patent/TW211592B/zh not_active IP Right Cessation
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60216818A (en) * | 1984-01-06 | 1985-10-30 | ポ−ル・コ−ポレ−シヨン | Cylindrical fibrous structure and its production |
| JPH0351310A (en) * | 1989-07-15 | 1991-03-05 | James River Corp:The | Melt-blown polymer dispersion |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5665235A (en) * | 1995-05-09 | 1997-09-09 | Pall Corporation | Supported fibrous web assembly |
| JP4721521B2 (en) * | 1999-04-21 | 2011-07-13 | ジーイー・オズモニクス・インコーポレイテッド | Non-woven depth filter component and manufacturing method thereof |
| JP2002542009A (en) * | 1999-04-21 | 2002-12-10 | オズモニクス， インコーポレイテッド | Nonwoven depth filter component and method of making same |
| JP2006297388A (en) * | 2005-04-19 | 2006-11-02 | Howard William Morgan | Filter element having variable-density side wall |
| JP2006297389A (en) * | 2005-04-19 | 2006-11-02 | Howard William Morgan | Filter element having variable-density side wall |
| WO2007018165A1 (en) * | 2005-08-10 | 2007-02-15 | Toray Industries, Inc. | Sponge-like structural body or powder, and process for production thereof |
| JP2007077563A (en) * | 2005-08-19 | 2007-03-29 | Toray Ind Inc | Powder comprising ultrafine fiber and method for producing the same |
| JP2009095787A (en) * | 2007-10-18 | 2009-05-07 | Fujifilm Corp | Agent and method for removing harmful substance |
| JP2009219952A (en) * | 2008-03-13 | 2009-10-01 | Kurita Water Ind Ltd | Fiber for filter, bobbin type filter, and water treatment method |
| WO2010005060A1 (en) * | 2008-07-10 | 2010-01-14 | 株式会社ニフコ | Fuel filter |
| JP2010019151A (en) * | 2008-07-10 | 2010-01-28 | Nifco Inc | Fuel filter |
| US8173013B2 (en) | 2008-07-10 | 2012-05-08 | Nifco Inc. | Fuel filter |
| JP2014240537A (en) * | 2013-05-17 | 2014-12-25 | アンビック株式会社 | Filament nonwoven fabric, oil absorber obtained by using the same, and method for producing filament nonwoven fabric |
| JP2019537503A (en) * | 2016-10-06 | 2019-12-26 | グロッツ−ベッケルト・カーゲー | Method for producing pleated textiles having electrostatically charged fibers and pleated textiles |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0798131B2 (en) | 1995-10-25 |
| TW211592B (en) | 1993-08-21 |
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