JP2012236178A - Method for producing vinylidene fluoride resin porous membrane - Google Patents
Method for producing vinylidene fluoride resin porous membrane Download PDFInfo
- Publication number
- JP2012236178A JP2012236178A JP2011108249A JP2011108249A JP2012236178A JP 2012236178 A JP2012236178 A JP 2012236178A JP 2011108249 A JP2011108249 A JP 2011108249A JP 2011108249 A JP2011108249 A JP 2011108249A JP 2012236178 A JP2012236178 A JP 2012236178A
- Authority
- JP
- Japan
- Prior art keywords
- vinylidene fluoride
- solvent
- inorganic particles
- porous membrane
- producing
- 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.)
- Withdrawn
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Artificial Filaments (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Activated Sludge Processes (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
Abstract
Description
本発明は、フッ化ビニリデン系多孔質膜の製造方法に関する。さらに詳しくは、膜分離活性汚泥法などに有効に用いられるフッ化ビニリデン系多孔質膜の製造方法に関する。 The present invention relates to a method for producing a vinylidene fluoride based porous membrane. More specifically, the present invention relates to a method for producing a vinylidene fluoride porous membrane that is effectively used in a membrane separation activated sludge method or the like.
精密ろ過膜、限外ろ過膜などの多孔質膜を用いたろ過操作は、医薬・食品産業での除菌作業や、半導体産業での超純水製造過程などの多くの分野で用いられている。特に近年では、浄水分野における除菌あるいは下水分野における除菌、除濁にも応用されており、特に下水分野では、膜分離活性汚泥法での利用が非常に盛んである。この膜分離活性汚泥法で用いる膜には、耐久性、ろ過性能のいずれの性能にもすぐれていることが要求される。 Filtration operations using porous membranes such as microfiltration membranes and ultrafiltration membranes are used in many fields such as sterilization work in the pharmaceutical and food industries and ultrapure water production processes in the semiconductor industry. . In particular, in recent years, it has also been applied to sterilization in the water purification field or sterilization and turbidity in the sewage field. In particular, in the sewage field, use in the membrane separation activated sludge method is very active. The membrane used in this membrane separation activated sludge method is required to be excellent in both durability and filtration performance.
ここで、耐久性として、膜分離活性汚泥法では膜表面の洗浄としてエアースクラビングを行うため、糸切れが起こらないような高い力学的特性が必要となる。また、バイオファウリング防止のため次亜塩素酸ナトリウムなどの殺菌剤を用いることから、耐薬品性も要求される。このような特性を満足させる多孔質膜として、強度、伸度が高く、耐薬品性にすぐれ、さらには疎水性で耐水性が高いフッ化ビニリデン系多孔質膜が多く用いられている。 Here, as durability, in the membrane separation activated sludge method, since air scrubbing is performed as cleaning of the membrane surface, high mechanical characteristics are required so that yarn breakage does not occur. In addition, chemical resistance is also required because a bactericide such as sodium hypochlorite is used to prevent biofouling. As a porous film satisfying such characteristics, a vinylidene fluoride porous film having high strength and elongation, excellent chemical resistance, and hydrophobic and high water resistance is often used.
一方、ろ過性能としては、透水性能および分画性能が求められている。これら透水性能、分画性能は、膜の表面構造や内部構造で決定され、これらの性能は多孔質膜の製造方法に大きく依拠している。透水性および分画性能にすぐれた膜の製造方法として、相分離を利用する方法が多く知られており、これには、非溶剤誘起相分離法と熱誘起相分離法がある。 On the other hand, water filtration performance and fractionation performance are required as filtration performance. These water permeation performance and fractionation performance are determined by the surface structure and internal structure of the membrane, and these performances greatly depend on the method for producing the porous membrane. As a method for producing a membrane excellent in water permeability and fractionation performance, many methods utilizing phase separation are known, and there are a non-solvent induced phase separation method and a heat induced phase separation method.
熱誘起相分離法は、高分子物質を高温で融解させるため、室温では溶解させる溶媒がないために通常の相分離法が適用できなかったポリエチレン、ポリプロピレンなどの結晶性高分子への適用が可能であり、得られる多孔質膜には大きな孔(マクロボイド)が形成されず、力学的特性が高い膜が得られるといった利点を有している。さらに、水に浸漬することによって多孔質膜を作製する非溶媒誘起相分離法では、溶媒のほか非溶媒も必要であり、その結果膜作成過程の制御が難しく再現性が低い場合があるのに対し、熱誘起相分離法では、非溶媒が不要であり、プロセスの制御が容易で、再現性も高いといったメリットもある。 Thermally induced phase separation method melts polymer materials at high temperatures, so it can be applied to crystalline polymers such as polyethylene and polypropylene, where normal phase separation methods cannot be applied because there is no solvent to dissolve at room temperature. In the obtained porous film, there is an advantage that large pores (macrovoids) are not formed and a film having high mechanical properties can be obtained. Furthermore, the non-solvent-induced phase separation method in which a porous membrane is produced by immersing in water requires a non-solvent in addition to a solvent, and as a result, it is difficult to control the membrane preparation process and may not be reproducible. On the other hand, the thermally induced phase separation method does not require a non-solvent, has the advantages of easy process control and high reproducibility.
かかる利点を有する熱誘起相分離法は、液−液相分離が起こるL-L(液−液)型、高分子の結晶化が起こるS-L(固−液)型、溶媒の結晶化が起こるL-S(液−固)型の3種に分類される(非特許文献１)。L-L型の熱誘起相分離法は、スピノーダル分解により相分離が進行するため、非連続構造が発現し易く、孔が均一に連通する。よって、透水性、分画性能にすぐれた膜を製造するためには、L-L型の熱誘起相分離法が適している。 Thermally induced phase separation methods having such advantages include LL (liquid-liquid) type in which liquid-liquid phase separation occurs, SL (solid-liquid) type in which crystallization of polymer occurs, and LS (liquid in which solvent crystallization occurs). -It is classified into three types of solid type (Non-Patent Document 1). In the L-L type thermally induced phase separation method, phase separation proceeds by spinodal decomposition, so that a discontinuous structure is easily developed and pores communicate uniformly. Therefore, the L-L type thermally induced phase separation method is suitable for producing a membrane having excellent water permeability and fractionation performance.
フッ化ビニリデン樹脂でL-L型の熱誘起相分離法を発現する組み合わせとしては、フタル酸エステル類を溶剤として用いたものが提案されている(特許文献１)。フタル酸エステル類を溶剤として用いた場合、膜中から溶剤を抽出することで多孔質化するものであり、溶剤の抽出には主として塩化メチレンが用いられている。しかるに、フタル酸エステル類や塩化メチレンは、PRTR対象物質に選定されるなど、製造時の環境負荷が高いことが問題となっており、その使用は望ましくない状況となってきている。 A combination using a phthalate ester as a solvent has been proposed as a combination of a vinylidene fluoride resin that exhibits an L-L type thermally induced phase separation method (Patent Document 1). When phthalates are used as a solvent, they are made porous by extracting the solvent from the membrane, and methylene chloride is mainly used for the extraction of the solvent. However, phthalates and methylene chloride are selected as PRTR substances, and thus there is a problem that the environmental load during production is high, and their use has become undesirable.
このような状況に鑑み、環境負荷が低い水溶性の溶媒を用いる方法が多く試みられている。しかしながら、水溶性の溶媒ではL-L型の熱誘起相分離法を発現することは困難であり、通常はS-L型の熱誘起相分離法となってしまう。このS-L型の熱誘起相分離法では、結晶が形成され、球晶間の間隙が孔となるため表面孔径が大きくなる傾向があり、多くは表面孔径が1μm以上である。膜の孔径が1μmを超えると大腸菌などの概ね1μm程度の細菌などの懸濁質を有効にろ別分離できなくなる。 In view of such a situation, many methods using a water-soluble solvent having a low environmental load have been tried. However, it is difficult to develop an L-L type thermally induced phase separation method with a water-soluble solvent, and this usually results in an SL type thermally induced phase separation method. In this S-L type thermally induced phase separation method, crystals are formed and the gaps between the spherulites become pores, so the surface pore diameter tends to increase, and in many cases the surface pore diameter is 1 μm or more. If the pore size of the membrane exceeds 1 μm, suspended substances such as bacteria of about 1 μm, such as E. coli, cannot be effectively separated by filtration.
これに対して、孔径を小さくするために、粒子系が小さいシリカを添加することが試みられている(特許文献２)。しかし、この文献記載の方法では1μm以下といった微細なサイズのシリカを均一に分散させることは困難であるため、膜の構造の連結性が低下し、膜の力学的特性が低くなるという問題があった。 In contrast, attempts have been made to add silica having a small particle system in order to reduce the pore size (Patent Document 2). However, in the method described in this document, since it is difficult to uniformly disperse silica having a fine size of 1 μm or less, there is a problem that the connectivity of the membrane structure is lowered and the mechanical properties of the membrane are lowered. It was.
したがって、製造時の環境負荷が低く、力学的特性、耐薬品性、透水性、分画性能にすぐれる多孔質膜の製造方法が求められている。 Therefore, there is a need for a method for producing a porous membrane that has a low environmental impact during production and is excellent in mechanical properties, chemical resistance, water permeability, and fractionation performance.
本発明の目的は、製造時の環境負荷が低く、力学的特性、耐薬品性、透水性、分画性能にすぐれた多孔質膜の製造方法を提供することにある。 An object of the present invention is to provide a method for producing a porous membrane having a low environmental load during production and excellent mechanical properties, chemical resistance, water permeability, and fractionation performance.
かかる本発明の目的は、フッ化ビニリデン系樹脂、無機粒子、凝集剤および溶剤を含有する紡糸原液を芯液とともに二重環状ノズルから乾湿式紡糸または湿式紡糸して得られる中空繊維を、凝固浴中に浸漬して相分離を誘起させた後固化させ、次いで中空繊維を延伸してから無機粒子、凝集剤、溶剤を抽出するための浸漬処理を行うことによりフッ化ビニリデン系多孔質膜を製造するに際し、紡糸原液として、溶剤に対する無機粒子の重量比を40〜80％とし、かつ無機粒子に対する凝集剤の重量比を68〜80％としたものを用いることによって達成される。 An object of the present invention is to provide a hollow fiber obtained by dry-wet spinning or wet spinning of a spinning stock solution containing a vinylidene fluoride resin, inorganic particles, a flocculant and a solvent together with a core solution from a double annular nozzle. A vinylidene fluoride-based porous membrane is produced by dipping in to induce phase separation and solidifying, then drawing the hollow fiber and then dipping to extract inorganic particles, flocculant, and solvent In this case, the spinning dope is achieved by using a weight ratio of inorganic particles to the solvent of 40 to 80% and a weight ratio of the flocculant to the inorganic particles of 68 to 80%.
本発明方法によって得られるフッ化ビニリデン系多孔質膜は、実用に耐え得る透水性、分画性能を有する上、膜構造の連結性が高いため、力学的特性が高いといったすぐれた効果を奏する。 The vinylidene fluoride-based porous membrane obtained by the method of the present invention has excellent water permeability and fractionation performance that can withstand practical use, and also has excellent mechanical properties due to high connectivity of the membrane structure.
フッ化ビニリデン系多孔質膜は、フッ化ビニリデン系樹脂、無機粒子、凝集剤および溶剤を含有する紡糸原液を芯液とともに二重環状ノズルから乾湿式紡糸または湿式紡糸して得られる中空繊維を、凝固浴中に浸漬して相分離を誘起させた後固化させ、次いで中空繊維を延伸してから無機粒子、凝集剤、溶剤のいずれかを抽出するための浸漬処理を行うことにより製造され、紡糸原液としては、フッ化ビニリデン系樹脂、無機粒子、凝集剤および溶剤を含有し、溶剤に対する無機粒子の重量比を40〜80％とし、かつ無機粒子に対する凝集剤の重量比を68〜80％としたものが用いられる。 The vinylidene fluoride porous membrane is a hollow fiber obtained by dry-wet spinning or wet spinning a spinning stock solution containing a vinylidene fluoride resin, inorganic particles, a flocculant and a solvent together with a core liquid from a double annular nozzle. Produced by dipping in a coagulation bath to induce phase separation and solidifying, then drawing the hollow fiber and then dipping to extract any of inorganic particles, flocculants, and solvents, spinning The stock solution contains a vinylidene fluoride resin, inorganic particles, a flocculant and a solvent, the weight ratio of the inorganic particles to the solvent is 40 to 80%, and the weight ratio of the flocculant to the inorganic particles is 68 to 80%. Used.
フッ化ビニリデン系樹脂としては、フッ化ビニリデンのホモポリマー(ポリフッ化ビニリデン)、フッ化ビニリデンと他の共重合可能なモノマーとの共重合体あるいはこれらの混合物が用いられる。フッ化ビニリデン樹脂と共重合可能なモノマーとしては、テトラフルオロエチレン、ヘキサフルオロプロペン、トリフルオロクロロエチレン、フッ化ビニルなどの少なくとも一種を用いることができ、好ましくは力学的特性および耐薬品性の高さから、ポリフッ化ビニリデンが用いられる。 As the vinylidene fluoride resin, a homopolymer of vinylidene fluoride (polyvinylidene fluoride), a copolymer of vinylidene fluoride and another copolymerizable monomer, or a mixture thereof is used. As the monomer copolymerizable with the vinylidene fluoride resin, at least one of tetrafluoroethylene, hexafluoropropene, trifluorochloroethylene, vinyl fluoride and the like can be used, preferably having high mechanical properties and high chemical resistance. Thus, polyvinylidene fluoride is used.
無機粒子としては、粒子分布が狭く、多孔質膜の核となり、薬品などによる抽出が容易であるものが用いられ、例えばシリカ、珪酸マグネシウム、珪酸アルミニウム、珪酸カルシウム、炭酸マグネシウム、炭酸カルシウム、リン酸カルシウム、鉄、亜鉛などの金属酸化物または水酸化物、ナトリウム、カリウム、カルシウムなどの塩類などが挙げられる。これらの中でも好ましくはフッ化ビニリデン樹脂と溶剤との相溶状態を安定化させ、さらに孔径を制御することができ、かつ凝集性を有する無機粒子として、特に好ましくはシリカが用いられる。無機粒子は通常、粒径または凝集性を有する粒子の凝集粒子径が1μm以下、好ましくは0.1〜1μmのものが用いられる。 As the inorganic particles, particles that have a narrow particle distribution, become the core of the porous membrane, and can be easily extracted with chemicals, etc., such as silica, magnesium silicate, aluminum silicate, calcium silicate, magnesium carbonate, calcium carbonate, calcium phosphate, Examples thereof include metal oxides or hydroxides such as iron and zinc, and salts such as sodium, potassium and calcium. Among these, silica is particularly preferably used as inorganic particles that can stabilize the compatible state of the vinylidene fluoride resin and the solvent, can further control the pore diameter, and have cohesive properties. In general, inorganic particles having a particle size or aggregating particle size of 1 μm or less, preferably 0.1 to 1 μm are used.
凝集剤としては、無機粒子と親和性があり、無機粒子の凝集性を向上させるもの、例えばグリセリンなどの多価アルコール類あるいはポリグリセリン脂肪酸エステル類などが用いられる。 As the aggregating agent, those having affinity for inorganic particles and improving the aggregating property of the inorganic particles, for example, polyhydric alcohols such as glycerin or polyglycerin fatty acid esters are used.
溶剤としては、フッ化ビニリデン樹脂とともにS-L型の熱誘起相分離法を発現し、水溶性であるγ-ブチロラクトン、ε-カプロラクトンなどが用いられる。 As the solvent, γ-butyrolactone, ε-caprolactone, etc., which exhibit an S-L type thermally induced phase separation method together with vinylidene fluoride resin, are used.
以上の必須成分よりなる紡糸原液は、溶剤に対する無機粒子の重量比が40〜80％、好ましくは40〜60％であって、無機粒子に対する凝集剤の重量比は68〜80％、好ましくは70〜75％のものが用いられる。溶剤に対する無機粒子の重量比がこれより高くなると膜構造の連結性が低下するため力学的特性が低下するようになり、一方これより少ない重量比で用いられると多孔質膜に形成される孔の体積分率が低下するため、透水性、分画性能が低下するようになる。また、無機粒子に対する凝集剤の重量比がこれより高くなると無機粒子の粗大な凝集体が形成されてしまうようになり、一方これより少ない重量比で用いられると無機粒子の凝集が不十分となるため、所望の孔径を得ることが困難となり、透水性、分画性能が低下するようになる。 The spinning dope comprising the above essential components has a weight ratio of inorganic particles to solvent of 40 to 80%, preferably 40 to 60%, and a weight ratio of flocculant to inorganic particles of 68 to 80%, preferably 70. ~ 75% is used. When the weight ratio of the inorganic particles to the solvent is higher than this, the connectivity of the membrane structure is lowered and the mechanical properties are lowered. On the other hand, when the weight ratio is lower, the pores formed in the porous film are reduced. Since the volume fraction is lowered, water permeability and fractionation performance are lowered. Further, if the weight ratio of the flocculant to the inorganic particles is higher than this, coarse aggregates of the inorganic particles will be formed, whereas if used at a lower weight ratio, the aggregation of the inorganic particles will be insufficient. Therefore, it becomes difficult to obtain a desired pore diameter, and the water permeability and the fractionation performance are lowered.
紡糸原液は、テトラエチレングリコール、グリセリンなどの芯液または空気、窒素などの気体とともに二重環状ノズルから押し出し、一般的にポリフッ化ビニリデン系多孔質膜の製造法で行われている乾湿式紡糸または湿式紡糸によって紡糸されて中空繊維が得られ、この中空繊維は水などの凝固浴中に浸漬して相分離を誘起させた後固化させ、次いで中空繊維を延伸してから、凝集剤、溶剤および芯液を抽出するため約40〜95℃の水中への浸漬および無機粒子を抽出するため水酸化ナトリウム水溶液などへの浸漬処理が行われる。 The spinning dope is extruded from a double annular nozzle together with a core liquid such as tetraethylene glycol or glycerin or a gas such as air or nitrogen, and is generally wet or dry spinning performed by a method for producing a polyvinylidene fluoride porous membrane. A hollow fiber is obtained by spinning by wet spinning. The hollow fiber is immersed in a coagulation bath such as water to induce phase separation and solidified, and then the hollow fiber is stretched, and then the flocculant, solvent and In order to extract the core liquid, immersion in water at about 40 to 95 ° C. and immersion treatment in an aqueous sodium hydroxide solution or the like are performed to extract inorganic particles.
浸漬処理後、さらに熱水などにより洗浄を行い、必要に応じて乾燥させることにより多孔質中空糸膜が製造される。 After the immersion treatment, the porous hollow fiber membrane is manufactured by further washing with hot water and drying it as necessary.
次に、実施例について本発明を説明する。 Next, the present invention will be described with reference to examples.
実施例、比較例１〜４
所定割合のポリフッ化ビニリデン(呉羽化学工業製品KFポリマー1000)、疎水性シリカ(日本アエロジル製品AEROSIL-R972；平均一次粒子径16nm、比表面積110m2/g)、ε-カプロラクトン(東京化成工業製品)およびグリセリン(関東化学製品)をヘンシェルミキサにより混合した。
Examples, Comparative Examples 1 to 4
Predetermined proportions of polyvinylidene fluoride (Kureha Chemical Product KF Polymer 1000), hydrophobic silica (Nippon Aerosil product AEROSIL-R972; average primary particle size 16 nm, specific surface area 110 m 2 / g), ε-caprolactone (Tokyo Kasei Kogyo product) And glycerin (Kanto Chemical) was mixed by Henschel mixer.
得られた混合物を、二軸混練押し出し機を用い、165℃で加熱混練してペレットとした後、このペレットを別の二軸押出機に投入し、二重環状ノズルにより中空部内にテトラエチレングリコールを芯液として供給しながら、150℃にて押し出し、押出物を約3cm空走させた後、20重量％の硫酸ナトリウム水溶液からなる水浴中を通過させて中空繊維を得た。 The resulting mixture was heated and kneaded at 165 ° C. using a twin-screw kneading extruder to form pellets, and then the pellets were put into another twin-screw extruder, and tetraethylene glycol was introduced into the hollow part by a double annular nozzle. Was extruded at 150 ° C. while being fed as a core solution, and the extrudate was allowed to run idle for about 3 cm, and then passed through a water bath composed of a 20 wt% sodium sulfate aqueous solution to obtain hollow fibers.
次いで、溶剤、凝集剤および無機粒子の大部分が中空繊維に残存している状態で、90℃の熱水中で繊維方向に1.5倍の長さとなるように延伸し、続いて95℃の水中に180分間浸せきすることにより、凝集剤であるグリセリン、溶剤であるε-カプロラクトンおよび芯液であるテトラエチレングリコールを除去した。さらに、40℃の5重量％水酸化ナトリウム水溶液に120分間浸せきして無機粒子を除去し、90℃の熱水で洗浄することにより中空糸膜を得た。 Next, in a state where most of the solvent, the flocculant and the inorganic particles remain in the hollow fiber, the fiber is stretched to a length of 1.5 times in hot fiber at 90 ° C. For 180 minutes, glycerin as a flocculant, ε-caprolactone as a solvent, and tetraethylene glycol as a core liquid were removed. Furthermore, the hollow fiber membrane was obtained by immersing in a 5 wt% sodium hydroxide aqueous solution at 40 ° C. for 120 minutes to remove inorganic particles and washing with hot water at 90 ° C.
得られた中空糸膜についての中空糸膜性状(外径、内径、純水透過速度、分画粒子径、引張強度および破断時伸び)を、用いられたポリフッ化ビニリデン、ε-カプロラクトン、疎水性シリカおよびグリセリンよりなる混合物の重量比、溶剤に対する無機粒子の重量比(無機粒子/溶剤)および無機粒子に対する凝集剤の重量比(凝集剤/無機粒子)と共に次の表に示した。
表
実施例 比較例１ 比較例２ 比較例３ 比較例４
〔混合物重量比：％〕
ポリフッ化ビニリデン 30 30 30 30 30
疎水性シリカ(無機粒子) 17 15 25 20 17
グリセリン(凝集剤) 12 10 20 10 15
ε-カプロラクトン(溶剤) 41 45 25 40 38
無機粒子/溶剤 41 33 100 50 45
凝集剤/無機粒子 71 67 80 50 88
〔中空糸膜性状〕
外径 1.25 1.27 1.23 1.25 1.24
内径 0.66 0.68 0.62 0.66 0.65
純水透過速度(L/時間・m2・0.1MPa) 6200 3200 7500 7600 6100
分画粒子径(μm) 0.5 0.4 0.6 1.6 1.3
引張強度(MPa) 2.6 2.0 1.1 2.2 2.1
破断時伸び(％) 21 10 3 12 11
The hollow fiber membrane properties (outer diameter, inner diameter, pure water permeation rate, fractional particle diameter, tensile strength and elongation at break) of the obtained hollow fiber membrane were used, polyvinylidene fluoride, ε-caprolactone, hydrophobicity The weight ratio of the mixture composed of silica and glycerin, the weight ratio of the inorganic particles to the solvent (inorganic particles / solvent), and the weight ratio of the flocculant to the inorganic particles (flocculating agent / inorganic particles) are shown in the following table.
table
Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4
[Mixture weight ratio:%]
Polyvinylidene fluoride 30 30 30 30 30
Hydrophobic silica (inorganic particles) 17 15 25 20 17
Glycerin (flocculant) 12 10 20 10 15
ε-Caprolactone (solvent) 41 45 25 40 38
Inorganic particles / solvent 41 33 100 50 45
Flocculant / inorganic particles 71 67 80 50 88
[Hollow fiber membrane properties]
Outer diameter 1.25 1.27 1.23 1.25 1.24
ID 0.66 0.68 0.62 0.66 0.65
Pure water permeation rate (L / hour ・ m 2・ 0.1MPa) 6200 3200 7500 7600 6100
Fractionated particle size (μm) 0.5 0.4 0.6 1.6 1.3
Tensile strength (MPa) 2.6 2.0 1.1 2.2 2.1
Elongation at break (%) 21 10 3 12 11
以上の各項目の測定、算出方法は、次の通りである。
〔純水透過係数〕
有効長15cmの両端開放型中空糸膜モジュールを用い、温度25℃、圧力0.1MPaの条件下、純水を原水として中空糸膜の内側から外側にろ過(内圧ろ過)して時間当りの透水量を測定し、単位膜面積、単位時間、0.1MPa当りの透水量に換算した数値で算出した。
〔分画粒子径〕
異なる粒子径を有する少なくとも２種類の単分散ラテックス(セラダイン社製品、固形分10質量％)を、0.5質量％ドデシルスルホン酸ナトリウム水溶液を用いて希釈し、ラテックス濃度0.01％の懸濁液を調製した。このラテックス懸濁液100mlをビーカーに入れ、チューブポンプにて有効長約12cmの湿潤した膜に対し、線速0.1m/秒にて外表面から0.03MPaの圧力にて供給し、膜の両端(大気解放)から透過液を出すことで、ラテックス懸濁液のろ過を行った。ろ過した液は、ビーカーに戻し、液的に閉鎖系にてろ過を行った。ろ過10分後に、中空糸膜の両端からの透過液およびビーカーからの供給液をそれぞれサンプリングし、分光光度計(日立ハイテクノロジーズ製U-2810)を用いて600nmの吸光度を測定し、以下の式によりラテックス阻止率を測定した。
ラテックス阻止率(％)＝100×(1-透過液の吸光度/供給液の吸光度)
ラテックス阻止率の曲線F(x)が対数正規分布の累積分布関数で表されると仮定して、測定値にフィッティングして、F(x)が90となるxの値を求め、これを分画粒子径とした。
F(x)＝100×1/2×erfc(-(In(x-μ)/√2σ))
(ここで、erfcは相補誤差関数、xはラテックス粒子径、μはIn(x)の平均値、
σはIn(x)の標準偏差である。)
〔引張破断強度、引張破断伸度〕
引張試験機(島津製作所製EZ-Test)を用い、温度25℃、相対湿度40〜70％の雰囲気内で、膜をチャック間距離50mm、速度200mm/分の条件で引張り、破断時の荷重と変位から以下の式に従い引張破断強度、引破断伸度を算出した。
引張破断強度(Pa)＝破断時荷重(N)/膜断面積(m2)
引張破断伸度(％)＝100×破断時変位(mm)/50(mm)
The measurement and calculation methods for the above items are as follows.
[Pure water permeability coefficient]
Using a hollow fiber membrane module with an open end of 15 cm in effective length and temperature of 25 ° C and pressure of 0.1 MPa, pure water as raw water is filtered from the inside to the outside of the hollow fiber membrane (internal pressure filtration). Were measured and converted into numerical values in terms of unit membrane area, unit time, and water permeability per 0.1 MPa.
[Fractionated particle size]
At least two types of monodisperse latexes having different particle sizes (Ceradyne product, solid content: 10% by mass) were diluted with 0.5% by mass aqueous sodium dodecylsulfonate solution to prepare a suspension having a latex concentration of 0.01%. . 100 ml of this latex suspension was placed in a beaker and supplied to a wet membrane with an effective length of about 12 cm with a tube pump at a linear velocity of 0.1 m / sec from the outer surface at a pressure of 0.03 MPa, both ends of the membrane ( The latex suspension was filtered by discharging the permeate from the atmosphere. The filtered liquid was returned to the beaker and filtered in a liquid closed system. After 10 minutes of filtration, the permeate from both ends of the hollow fiber membrane and the feed solution from the beaker were sampled, and the absorbance at 600 nm was measured using a spectrophotometer (Hitachi High-Technologies U-2810). Was used to measure the latex rejection.
Latex rejection (%) = 100 × (1-absorbance of permeate / absorbance of feed solution)
Assuming that the latex rejection rate curve F (x) is represented by a cumulative distribution function of lognormal distribution, fitting to the measured value, the value of x at which F (x) is 90 is obtained, and this is divided. It was set as the image particle diameter.
F (x) = 100 × 1/2 × erfc (-(In (x-μ) / √2σ))
(Where erfc is the complementary error function, x is the latex particle size, μ is the average value of In (x),
σ is the standard deviation of In (x). )
[Tensile breaking strength, tensile breaking elongation]
Using a tensile tester (EZ-Test, manufactured by Shimadzu Corporation), the film was pulled at a temperature of 25 ° C and a relative humidity of 40 to 70% under the conditions of a distance between chucks of 50 mm and a speed of 200 mm / min. From the displacement, the tensile strength at break and the elongation at break were calculated according to the following formula.
Tensile strength at break (Pa) = Load at break (N) / Cross-sectional area (m 2 )
Tensile elongation at break (%) = 100 x displacement at break (mm) / 50 (mm)
一方、ろ過性能としては、透水性能および分画性能が求められている。これら透水性能、分画性能は、膜の表面構造や内部構造で決定され、これらの性能は多孔質膜の製造方法に大きく依拠している。透水性および分画性能にすぐれた膜の製造方法として、相分離を利用する方法が多く知られており、これには、非溶媒誘起相分離法と熱誘起相分離法がある。 On the other hand, water filtration performance and fractionation performance are required as filtration performance. These water permeation performance and fractionation performance are determined by the surface structure and internal structure of the membrane, and these performances greatly depend on the method for producing the porous membrane. As a method for producing a membrane excellent in water permeability and fractionation performance, many methods utilizing phase separation are known, and there are a non- solvent induced phase separation method and a thermally induced phase separation method.
以上の各項目の測定、算出方法は、次の通りである。
〔純水透過係数〕
有効長15cmの両端開放型中空糸膜モジュールを用い、温度25℃、圧力0.1MPaの条件下、純水を原水として中空糸膜の内側から外側にろ過(内圧ろ過)して時間当りの透水量を測定し、単位膜面積、単位時間、0.1MPa当りの透水量に換算した数値で算出した。
〔分画粒子径〕
異なる粒子径を有する少なくとも２種類の単分散ラテックス(セラダイン社製品、固形分10質量％)を、0.5質量％ドデシルスルホン酸ナトリウム水溶液を用いて希釈し、ラテックス濃度0.01％の懸濁液を調製した。このラテックス懸濁液100mlをビーカーに入れ、チューブポンプにて有効長約12cmの湿潤した膜に対し、線速0.1m/秒にて外表面から0.03MPaの圧力にて供給し、膜の両端(大気解放)から透過液を出すことで、ラテックス懸濁液のろ過を行った。ろ過した液は、ビーカーに戻し、液的に閉鎖系にてろ過を行った。ろ過10分後に、中空糸膜の両端からの透過液およびビーカーからの供給液をそれぞれサンプリングし、分光光度計(日立ハイテクノロジーズ製U-2810)を用いて600nmの吸光度を測定し、以下の式によりラテックス阻止率を測定した。
ラテックス阻止率(％)＝100×(1-透過液の吸光度/供給液の吸光度)
ラテックス阻止率の曲線F(x)が対数正規分布の累積分布関数で表されると仮定して、測定値にフィッティングして、F(x)が90となるxの値を求め、これを分画粒子径とした。
F(x)＝100×1/2×erfc(-(ln(x-μ)/√2σ))
(ここで、erfcは相補誤差関数、xはラテックス粒子径、μはln(x)の平均値、
σはln(x)の標準偏差である。)
〔引張破断強度、引張破断伸度〕
引張試験機(島津製作所製EZ-Test)を用い、温度25℃、相対湿度40〜70％の雰囲気内で、膜をチャック間距離50mm、速度200mm/分の条件で引張り、破断時の荷重と変位から以下の式に従い引張破断強度、引破断伸度を算出した。
引張破断強度(Pa)＝破断時荷重(N)/膜断面積(m2)
引張破断伸度(％)＝100×破断時変位(mm)/50(mm)
The measurement and calculation methods for the above items are as follows.
[Pure water permeability coefficient]
Using a hollow fiber membrane module with an open end of 15 cm in effective length and temperature of 25 ° C and pressure of 0.1 MPa, pure water as raw water is filtered from the inside to the outside of the hollow fiber membrane (internal pressure filtration). Were measured and converted into numerical values in terms of unit membrane area, unit time, and water permeability per 0.1 MPa.
[Fractionated particle size]
At least two types of monodisperse latexes having different particle sizes (Ceradyne product, solid content: 10% by mass) were diluted with 0.5% by mass aqueous sodium dodecylsulfonate solution to prepare a suspension having a latex concentration of 0.01%. . 100 ml of this latex suspension was placed in a beaker and supplied to a wet membrane with an effective length of about 12 cm with a tube pump at a linear velocity of 0.1 m / sec from the outer surface at a pressure of 0.03 MPa, both ends of the membrane ( The latex suspension was filtered by discharging the permeate from the atmosphere. The filtered liquid was returned to the beaker and filtered in a liquid closed system. After 10 minutes of filtration, the permeate from both ends of the hollow fiber membrane and the feed solution from the beaker were sampled, and the absorbance at 600 nm was measured using a spectrophotometer (Hitachi High-Technologies U-2810). Was used to measure the latex rejection.
Latex rejection (%) = 100 × (1-absorbance of permeate / absorbance of feed solution)
Assuming that the latex rejection rate curve F (x) is represented by a cumulative distribution function of lognormal distribution, fitting to the measured value, the value of x at which F (x) is 90 is obtained, and this is divided. It was set as the image particle diameter.
F (x) = 100 × 1/2 × erfc (-( ln (x-μ) / √2σ))
(Where erfc is the complementary error function, x is the latex particle size, μ is the mean value of ln (x),
σ is the standard deviation of ln (x). )
[Tensile breaking strength, tensile breaking elongation]
Using a tensile tester (EZ-Test, manufactured by Shimadzu Corporation), the film was pulled at a temperature of 25 ° C and a relative humidity of 40 to 70% under the conditions of a distance between chucks of 50 mm and a speed of 200 mm / min. From the displacement, the tensile strength at break and the elongation at break were calculated according to the following formula.
Tensile strength at break (Pa) = Load at break (N) / Cross-sectional area (m 2 )
Tensile elongation at break (%) = 100 x displacement at break (mm) / 50 (mm)
Claims (6)
紡糸原液として、フッ化ビニリデン系樹脂、無機粒子、凝集剤および溶剤を含有し、溶剤に対する無機粒子の重量比を40〜80％とし、かつ無機粒子に対する凝集剤の重量比を68〜80％としたものを用いることを特徴とするフッ化ビニリデン系多孔質膜の製造方法。 A hollow fiber obtained by dry-wet spinning or wet spinning of a spinning stock solution containing a vinylidene fluoride resin, inorganic particles, a flocculant and a solvent together with a core solution from a double annular nozzle is immersed in a coagulation bath for phase separation. Inducing a vinylidene fluoride based porous membrane by solidifying and then stretching the hollow fiber and then performing an immersion treatment to extract inorganic particles, aggregating agent and solvent,
As the spinning dope, vinylidene fluoride resin, inorganic particles, flocculant and solvent are contained, the weight ratio of the inorganic particles to the solvent is 40 to 80%, and the weight ratio of the flocculant to the inorganic particles is 68 to 80%. A method for producing a vinylidene fluoride-based porous film, characterized in that
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011108249A JP2012236178A (en) | 2011-05-13 | 2011-05-13 | Method for producing vinylidene fluoride resin porous membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011108249A JP2012236178A (en) | 2011-05-13 | 2011-05-13 | Method for producing vinylidene fluoride resin porous membrane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2012236178A true JP2012236178A (en) | 2012-12-06 |
Family
ID=47459583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011108249A Withdrawn JP2012236178A (en) | 2011-05-13 | 2011-05-13 | Method for producing vinylidene fluoride resin porous membrane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2012236178A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103159309A (en) * | 2013-04-15 | 2013-06-19 | 池州灵芝化建材料科技有限公司 | Preparation method of flocculating agent |
| CN106237872A (en) * | 2016-08-29 | 2016-12-21 | 无锡零界净化设备有限公司 | A kind of hydrophilic modification method of microporous teflon membran |
| WO2017155004A1 (en) * | 2016-03-09 | 2017-09-14 | 旭化成株式会社 | Porous hollow fiber membrane, production method therefor, and filtration method |
| CN111005082A (en) * | 2019-12-17 | 2020-04-14 | 东华大学 | Whole-body porous polycaprolactone fiber and preparation method thereof |
| CN111050889A (en) * | 2017-09-01 | 2020-04-21 | 旭化成株式会社 | Porous hollow fiber membrane, method for producing porous hollow fiber membrane, and filtration method |
-
2011
- 2011-05-13 JP JP2011108249A patent/JP2012236178A/en not_active Withdrawn
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103159309A (en) * | 2013-04-15 | 2013-06-19 | 池州灵芝化建材料科技有限公司 | Preparation method of flocculating agent |
| WO2017155004A1 (en) * | 2016-03-09 | 2017-09-14 | 旭化成株式会社 | Porous hollow fiber membrane, production method therefor, and filtration method |
| JPWO2017155004A1 (en) * | 2016-03-09 | 2018-12-27 | 旭化成株式会社 | Porous hollow fiber membrane, method for producing the same, and filtration method |
| JP2020189294A (en) * | 2016-03-09 | 2020-11-26 | 旭化成株式会社 | Porous hollow fiber membrane and its manufacturing method, and filtration method |
| JP7019003B2 (en) | 2016-03-09 | 2022-02-14 | 旭化成株式会社 | Porous hollow fiber membrane, its manufacturing method, and filtration method |
| CN106237872A (en) * | 2016-08-29 | 2016-12-21 | 无锡零界净化设备有限公司 | A kind of hydrophilic modification method of microporous teflon membran |
| CN111050889A (en) * | 2017-09-01 | 2020-04-21 | 旭化成株式会社 | Porous hollow fiber membrane, method for producing porous hollow fiber membrane, and filtration method |
| CN111050889B (en) * | 2017-09-01 | 2023-03-03 | 旭化成株式会社 | Porous hollow fiber membrane, method for producing porous hollow fiber membrane, and filtration method |
| CN111005082A (en) * | 2019-12-17 | 2020-04-14 | 东华大学 | Whole-body porous polycaprolactone fiber and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5641553B2 (en) | Method for producing hollow fiber membrane | |
| JP5068168B2 (en) | Vinylidene fluoride resin hollow fiber porous membrane | |
| KR101657307B1 (en) | Fluorinated hollow fiber membrane and method for preparing the same | |
| WO2008018181A1 (en) | Porous membrane of vinylidene fluoride resin and process for producing the same | |
| US10406487B2 (en) | Hydrophilised vinylidene fluoride-based porous hollow fibre membrane, and manufacturing method therefor | |
| WO2001028667A1 (en) | Heat-resistant microporous film | |
| KR101026690B1 (en) | Highly porous membrane using that and preparing method thereof | |
| US11654400B2 (en) | Porous hollow fiber membrane and method for producing porous hollow fiber membrane | |
| JP2012236178A (en) | Method for producing vinylidene fluoride resin porous membrane | |
| JP6577781B2 (en) | Hollow fiber membrane and method for producing hollow fiber membrane | |
| JP2006297383A (en) | Hollow fiber membrane and its manufacturing method | |
| WO2007125709A1 (en) | Porous water treatment membrane made of vinylidene fluoride-based resin with little contamination and method of producing the same | |
| JP5318385B2 (en) | Porous membrane made of vinylidene fluoride resin and method for producing the same | |
| WO2010082437A1 (en) | Vinylidene fluoride resin hollow fiber porous membrane and process for producing same | |
| JP2013173139A (en) | Manufacturing method of porous hollow fiber membrane | |
| JP4564758B2 (en) | Method for producing vinylidene fluoride resin porous membrane | |
| JP4864707B2 (en) | Method for producing vinylidene fluoride resin porous water treatment membrane | |
| JP2008062227A (en) | Raw material solution for preparing membrane, porous membrane, and method for preparing porous membrane | |
| JP2003138422A (en) | Method for producing hollow fiber membrane and hollow fiber membrane module | |
| JP2013144264A (en) | Method for producing porous polysulfone-based membrane | |
| KR20130040620A (en) | Preparation method of hollow fiber membrane with high mechanical properties made of hydrophilic modified polyvinylidenefluoride for water treatment | |
| WO2007123004A1 (en) | Porous hollow-fiber membrane of vinylidene fluoride resin and process for producing the same | |
| KR101308998B1 (en) | The Preparation method of hollow fiber membrane with high mechanical properties using hydrophilized polyvinylidenefluoride for water treatment | |
| RU2440181C2 (en) | Porous membrane from vinylidene fluoride resin and method of its production | |
| WO2009119373A1 (en) | Hollow-fiber membrane and process for production thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20140805 |