JP4164774B2 - Method for producing selective separation membrane - Google Patents
Method for producing selective separation membrane Download PDFInfo
- Publication number
- JP4164774B2 JP4164774B2 JP2007321746A JP2007321746A JP4164774B2 JP 4164774 B2 JP4164774 B2 JP 4164774B2 JP 2007321746 A JP2007321746 A JP 2007321746A JP 2007321746 A JP2007321746 A JP 2007321746A JP 4164774 B2 JP4164774 B2 JP 4164774B2
- Authority
- JP
- Japan
- Prior art keywords
- membrane
- ufr
- selective separation
- water
- separation membrane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Description
本発明は、安定な分離特性を維持、回復できる分離膜を提供するものである。特に、蛋白が高濃度に存在する液の処理に用いる血液浄化膜や、懸濁成分が高濃度に存在する廃水および浄水処理膜などの選択分離膜による処理において、処理中の経時的な性能低下が少なく、かつ一旦低下した性能を容易に回復できる選択分離膜を提供するものである。 The present invention provides a separation membrane capable of maintaining and recovering stable separation characteristics. In particular, performance degradation over time during treatment in blood purification membranes used for the treatment of fluids with high protein concentrations, and selective separation membranes such as wastewater and water purification membranes with high concentrations of suspended components And a selective separation membrane that can easily recover the performance once reduced.
選択分離膜は現在、廃水処理、海水淡水化、浄水処理、ガス分離、血液浄化用途など、幅広く用いられている。廃水処理や飲料水製造、あるいは血液処理などに用いられる選択分離膜において、処理液中に含まれる溶質、懸濁成分、不溶解成分が、膜面に吸着、沈着し堆積すると、膜細孔の目詰まり、膜表面のケーク層形成をもたらし、その結果、透水速度や溶質透過速度の低下など膜の性能が経時的に劣化する。 Currently, selective separation membranes are widely used for wastewater treatment, seawater desalination, water purification, gas separation, blood purification, and the like. In selective separation membranes used in wastewater treatment, drinking water production, blood treatment, etc., if solutes, suspended components, and insoluble components contained in the treatment liquid are adsorbed, deposited, and deposited on the membrane surface, Clogging results in the formation of a cake layer on the membrane surface. As a result, the membrane performance deteriorates over time, such as a decrease in the water permeation rate and solute permeation rate.
そのため、このような用途に用いられる選択分離膜に対して、低下した性能を回復させるための手段が必要になる。例えば、廃水処理や飲料水製造に用いられる精密濾過膜（ＭＦ膜）や限外濾過膜（ＵＦ膜）は、定期的に逆洗作業（濾過と逆方向に水や気体を流して、膜表面に堆積したケーク層を破壊し、細孔に目詰まりした物質を除去する）や薬剤処理等で膜を洗浄する。血液処理膜の場合、例えば、使用後に血球成分や蛋白質が膜面に付着し性能が低下した血液透析器（ダイアライザー）を薬剤で洗浄し、膜性能を回復させ、再使用する事が米国などで広くおこなわれている。 Therefore, a means for recovering the reduced performance is required for the selective separation membrane used for such applications. For example, microfiltration membranes (MF membranes) and ultrafiltration membranes (UF membranes) used in wastewater treatment and drinking water production are regularly backwashed (flowing water or gas in the direction opposite to filtration, The cake layer deposited on the surface is destroyed and the substances clogged in the pores are removed), and the membrane is washed by chemical treatment or the like. In the case of blood treatment membranes, for example, in the United States, blood hemodialyzers (dialyzers) that have deteriorated performance due to adhesion of blood cell components and proteins to the membrane surface after use can be washed with chemicals to restore membrane performance and reuse in the United States, etc. Widely done.
膜を製造する立場からも、膜性能の経時劣化を防ぐ観点から、膜素材の改良が行われている。例えば、血液中の蛋白質は疎水性表面に吸着しやすい事から、血液透析膜素材の親水化が積極的に行われている。 From the standpoint of manufacturing a membrane, the membrane material has been improved from the viewpoint of preventing deterioration of the membrane performance over time. For example, since proteins in blood are easily adsorbed on a hydrophobic surface, the hemodialysis membrane material has been actively made hydrophilic.
しかしながら、性能の耐経時劣化性、および低下した性能の回復性について、十分満足する選択分離膜は未だ得られていないのが現状である。 However, at present, there has not yet been obtained a selective separation membrane that is sufficiently satisfactory with respect to the deterioration resistance of the performance with time and the recovery of the lowered performance.
選択分離膜の耐経時劣化性、および低下した性能の回復性について、本発明者らは鋭意検討をおこなった結果、本発明に至った。すなわち、本発明は、
１）ポリアクリロニトリル系共重合体、ポリメチルメタクリレート、エチレンビニルアルコール共重合体から選ばれるポリマーからなる中空糸膜成型時、ポリマー溶液中のポリマー濃度を１５重量％以上とし、電解質を１重量％以上含み、ポリマー溶液の口金部のドラフト比（凝固浴突入線速度／口金部吐出線速度）を５以上とし、かつ中空形成材として吐出する芯液のドラフト比を１．５以下とすることにより、膜構造が実質的にマクロボイドが観測されない実質的に均一膜であって、且つ、膜厚が１０〜５０μmの範囲であり、生理食塩水中の透水速度（ＵＦＲ（Ｓ））と純水中の透水速度（ＵＦＲ（Ｐ））の比が下記式を満足する選択分離膜を得る選択分離膜の製造方法である。
ＵＦＲ（Ｓ）／ＵＦＲ（Ｐ）≧ １．０７
２）膜断面を走査型電子顕微鏡により１０００倍で観察したときに、直径が０．５μm以上の大きさのボイドやスポンジ構造に由来する空隙が観察されない均一構造を示すことを特徴とする選択分離膜の製造方法である。
As a result of intensive investigations on the anti-aging degradation property of the selective separation membrane and the recoverability of the reduced performance, the present inventors have arrived at the present invention. That is, the present invention
1) At the time of forming a hollow fiber membrane made of a polymer selected from polyacrylonitrile copolymer, polymethyl methacrylate, and ethylene vinyl alcohol copolymer , the polymer concentration in the polymer solution is 15% by weight or more, and the electrolyte is 1% by weight or more. Including, the draft ratio of the base part of the polymer solution (solidification bath entry linear speed / base part discharge linear speed) is 5 or more, and the draft ratio of the core liquid discharged as a hollow forming material is 1.5 or less, The membrane structure is a substantially uniform membrane in which no macrovoids are observed, the thickness is in the range of 10 to 50 μm, and the water permeability (UFR (S)) in saline and pure water This is a selective separation membrane manufacturing method for obtaining a selective separation membrane in which the ratio of the water permeation rate (UFR (P)) satisfies the following formula.
UFR (S) / UFR (P) ≧ 1.07
2) Selective separation characterized by showing a uniform structure in which voids derived from voids or sponge structures having a diameter of 0.5 μm or more are not observed when the cross section of the film is observed at 1000 times with a scanning electron microscope It is a manufacturing method of a film | membrane.
本発明の選択分離膜は、処理中の経時的な性能低下が少なく、かつ、一旦低下した性能を容易に回復することができる。従って、蛋白質が高濃度に存在する液の処理に用いる血液浄化膜や、懸濁成分が高濃度に存在する廃水および水道水処理膜などの選択分離膜等として有用である。 The selective separation membrane of the present invention is less susceptible to performance degradation over time during processing and can easily recover performance once degraded. Therefore, it is useful as a blood separation membrane used for the treatment of a liquid in which protein is present at a high concentration, a selective separation membrane such as a waste water and tap water treatment membrane in which suspended components are present at a high concentration, and the like.
透水速度とは、被処理液（純水中または生理食塩水）を選択分離膜で濾過処理した際に、単位時間、単位圧力、単位膜面積当たりに濾過される被処理液体積を表す。一般に、透水速度は、被処理液の粘度に依存する。３７℃における純水の粘度は０．７０ｃＰ、生理食塩水の粘度は０．７１ｃＰであり、生理食塩水の粘度は約１％純水より高い値を持つので、食塩に対して排除性を持たない一般的な膜の場合、生理食塩水中の透水速度は、純水中の透水速度より低い値になる。しかしながら、本発明者らが検討を行ったところ、ある種の膜では驚くべきことに生理食塩水中の透水速度が純水中の透水速度より高い値を持ち、かつその比が１．０７以上の膜は、安定な分離特性を維持し、かつ、一旦低下した膜の性能を容易に回復できることを見出した。 The water permeation speed represents the volume of liquid to be treated that is filtered per unit time, unit pressure, and unit membrane area when the liquid to be treated (pure water or physiological saline) is filtered through a selective separation membrane. In general, the water permeation rate depends on the viscosity of the liquid to be treated. The viscosity of pure water at 37 ° C. is 0.70 cP, the viscosity of physiological saline is 0.71 cP, and the viscosity of physiological saline is higher than that of about 1% pure water. In the case of a non-general membrane, the permeation rate in saline is lower than the permeation rate in pure water. However, as a result of studies by the present inventors, surprisingly, in certain types of membranes, the water permeation rate in physiological saline has a higher value than the water permeation rate in pure water, and the ratio is 1.07 or more. It has been found that the membrane maintains stable separation characteristics and can easily recover the once-reduced membrane performance.
この現象の機構については、明確ではないが、選択分離膜を形成する分子鎖中にある正および負の荷電があり静電引力によって収縮を保っている選択分離膜の場合、イオンを含む生理食塩水中では、電荷を持ったイオンのため膜分子中の荷電が打ち消され、収縮が緩和されて膜が膨潤し、細孔径が増大し、その結果、純水よりも生理食塩水中の透水速度が増加するものと考えられる。 Although the mechanism of this phenomenon is not clear, in the case of a selective separation membrane having positive and negative charges in the molecular chain forming the selective separation membrane and maintaining contraction by electrostatic attraction, physiological saline containing ions In water, due to the charged ions, the charge in the membrane molecule is canceled, the contraction is relaxed, the membrane swells, the pore diameter increases, and as a result, the water permeation rate in saline is increased compared to pure water. It is thought to do.
このような生理食塩水中で透水速度が増加する選択分離膜を、血液透析などの血液浄化膜に用いると、血液はイオン含むので膜が膨潤し、膜面への蛋白質の吸着や堆積が抑えられ、経時的な性能低下が少ない利点を有する。さらに、イオンを含まない溶液で洗浄することで、膜を収縮させ、膜構造を変化させることにより、吸着および堆積した蛋白質がはがれやすくなり、低下した膜性能を容易に回復させることができる。 When such a selective separation membrane that increases the water permeation rate in physiological saline is used for a blood purification membrane such as hemodialysis, the blood swells and the membrane swells, preventing protein adsorption and deposition on the membrane surface. , It has the advantage of less performance degradation over time. Furthermore, by washing with a solution containing no ions, the membrane is contracted and the membrane structure is changed, whereby the adsorbed and deposited proteins are easily peeled off, and the reduced membrane performance can be easily recovered.
本発明の選択膜は、排水処理や水道水製造などのイオンをほとんど含まない被処理液に用いた場合においても、被処理液中の不純物や溶質の目詰まりおよびケーク層形成で低下した性能を、イオン強度が強い水溶液を流す事で、膜を膨潤させ、目詰まりやケーク層を解消させる事ができる点で有用である。イオン強度の強い水溶液とは、例えば食塩水などを挙げる事ができる。食塩水は、そのまま廃棄しても環境汚染などの点で、現在一般に使われている洗剤や薬液よりも安全である。 Even when the selective membrane of the present invention is used in a liquid to be treated that contains almost no ions, such as waste water treatment and tap water production, the performance of the process liquid is reduced due to clogging of impurities and solutes in the liquid to be treated and formation of a cake layer. It is useful in that an aqueous solution having a strong ionic strength can be used to swell the membrane and eliminate clogging and a cake layer. Examples of the aqueous solution having a strong ionic strength include saline. Saline is safer than commonly used detergents and chemicals in terms of environmental pollution even if it is discarded as it is.
本発明において、生理食塩水中の透水速度と純水中の透水速度の比は１．０７以上である。これは、血液のようなイオンを含む被処理液中で膜構造を変化させ、蛋白質や血球成分の吸着や堆積などによる膜の経時的性能低下を防ぎ、膜の経時的性能維持と、低下した膜性能を回復させるためである。生理食塩水中の透水速度と純水中の透水速度の比が１．０７より小さいと、膜構造変化が小さく、前述のような効果が得られない。もちろん、膜構造が全く変化しない場合、透水速度は被処理液の粘度に依存するので、従来技術の膜においては生理食塩水中と純水中の透水速度の比は約０．９９である。生理食塩水中の透水速度と純水中の透水速度の比が１．０７以上の範囲においては、より大きな透水速度の比であれば、膜構造変化が大きく、より大きな効果が得られるので、１．１０以上が好ましく、１．１５以上であれば更に好ましい。 In the present invention, the ratio of the water transmission rate in physiological saline and the water transmission rate in pure water is 1.07 or more. This changes the membrane structure in the treatment liquid containing ions such as blood, prevents the deterioration of the membrane performance over time due to the adsorption and deposition of proteins and blood cell components, etc. This is to restore the membrane performance. If the ratio of the water permeation rate in physiological saline and the water permeation rate in pure water is smaller than 1.07, the membrane structure change is small and the above-described effects cannot be obtained. Of course, when the membrane structure does not change at all, the water permeation rate depends on the viscosity of the liquid to be treated, so in the membrane of the prior art, the ratio of the water permeation rate between physiological saline and pure water is about 0.99. In the range where the ratio of the water permeation rate in physiological saline and the water permeation rate in pure water is 1.07 or more, if the ratio of the water permeation rate is larger, the membrane structure changes greatly and a greater effect can be obtained. .10 or more is preferable and 1.15 or more is more preferable.
本発明においては、生理食塩水中の透水速度と純水中の透水速度の変化が可逆的であることが好ましい。可逆的に変化すれば、使用後の膜性能回復を繰り返し実施することで、何回でも膜を再使用することが出来、その結果、膜モジュールのランニングコストを低下できる。 In the present invention, it is preferable that the change in the water transmission rate in physiological saline and the water transmission rate in pure water is reversible. If it changes reversibly, the membrane can be reused any number of times by repeatedly performing the membrane performance recovery after use, and as a result, the running cost of the membrane module can be reduced.
本発明の選択分離膜の構造は、特に限定されるものではないが、実質的にマクロボイドが観測されない実質的に均一な膜であることが好ましい。膜の内表面あるいは外表面に緻密なスキン層を持ち中間部にボイドを含有する支持層を持つ構造では、スキン層の構造変化が起きにくいためか本発明の効果が得られにくい。また、選択分離膜にマクロボイドが存在すると、膜構成分子間の距離が大きく、膜構成分子間の静電引力による膜収縮が働きにくくなるためか本発明の効果が得られにくい。ここで、実質的にマクロボイドが観察されない実質的に均一な膜とは、膜断面を走査型電子顕微鏡により１０００倍で観察したときに、直径が０．５μm以上の大きさのボイドやスポンジ構造に由来する空隙が観察されない均一構造を示す。素材によっては、さらに高倍率（５０００倍以上）の観察によって直径が０．５μm未満のボイドや空隙が観察される。ボイドや空隙の直径が０．５μm未満の場合は、存在しても、生理食塩水中の透水速度と純水中の透水速度の比を１．０７以上にすることが可能である。一方、実質的に均一な膜であるにもかかわらず、製膜時の欠陥（例えば異物や気泡の混入）により、０．５μm以上の大きさのボイドや空隙が観察され、該欠陥が膜全体の極一部分の場合は、該比１．０７以上を達成することが可能である。従って、このような欠陥による選択分離膜の極一部分に存在するマクロボイドなら観察されても構わない。 The structure of the selective separation membrane of the present invention is not particularly limited, but is preferably a substantially uniform membrane in which no macrovoids are observed. In the structure having a dense skin layer on the inner surface or outer surface of the film and a support layer containing voids in the middle part, it is difficult to obtain the effect of the present invention because the structure of the skin layer hardly changes. In addition, when macrovoids are present in the selective separation membrane, the distance between the membrane constituent molecules is large, and the membrane contraction due to electrostatic attraction between the membrane constituent molecules becomes difficult to work, so that it is difficult to obtain the effects of the present invention. Here, a substantially uniform film in which no macrovoids are observed is a void or sponge structure having a diameter of 0.5 μm or more when the cross section of the film is observed at 1000 times with a scanning electron microscope. The uniform structure where the space | gap originating in is not observed is shown. Depending on the material, voids and voids having a diameter of less than 0.5 μm are observed by observation at a higher magnification (5000 times or more). When the diameter of the void or void is less than 0.5 μm, even if it exists, the ratio of the water transmission rate in physiological saline and the water transmission rate in pure water can be 1.07 or more. On the other hand, despite the fact that the film is substantially uniform, voids and voids with a size of 0.5 μm or more are observed due to defects during film formation (for example, inclusion of foreign matter or bubbles), and the defects are observed throughout the film. In the case of a very small part, it is possible to achieve the ratio of 1.07 or more. Therefore, macro voids existing in a very small part of the selective separation membrane due to such defects may be observed.
本発明の選択分離膜の膜厚は、１０〜５０μmの範囲であると膜構造の変化を起こしやすく好ましい。膜厚が５０μmより大きい場合は、膜構造が強固になりすぎ、膜構造の荷電による静電引力による膜収縮が起こりにくくなるため本発明の効果が得られにくいと考えられる。一方、選択膜の膜厚が１０μmより小さい場合は、膜構造中の電荷の分布が狭く、純水中と生理食塩水中の透水速度の差が生じにくくなるためと考えられる。 The film thickness of the selective separation membrane of the present invention is preferably in the range of 10 to 50 μm because the membrane structure is likely to change. When the film thickness is larger than 50 μm, the film structure becomes too strong, and film contraction due to electrostatic attraction due to charging of the film structure hardly occurs, so that it is considered that the effect of the present invention is hardly obtained. On the other hand, when the thickness of the selective membrane is smaller than 10 μm, it is considered that the charge distribution in the membrane structure is narrow and the difference in the water transmission rate between pure water and physiological saline is less likely to occur.
本発明において選択分離膜の素材は、特に限定されるものではなく、再生セルロース、セルロースアセテート、ポリスルホン、ポリアクリロニトリル、ポリメチルメタクリレート、エチレンビニルアルコール共重合体、ポリビニルアルコールなどが挙げられるが、特に、分子内に陰性あるいは陽性荷電を持つポリアクリロニトリル系重合体、あるいは分子内に極性を持つポリメチルメタクリレートやエチレンビニルアルコール共重合体が、好適に使用できる。 In the present invention, the material of the selective separation membrane is not particularly limited, and examples thereof include regenerated cellulose, cellulose acetate, polysulfone, polyacrylonitrile, polymethyl methacrylate, ethylene vinyl alcohol copolymer, and polyvinyl alcohol. A polyacrylonitrile polymer having negative or positive charge in the molecule, or polymethyl methacrylate or ethylene vinyl alcohol copolymer having polarity in the molecule can be preferably used.
本発明の分離膜の製法は特に限定されるものではなく、中空糸膜や平膜などの形で製造され得るが、特に中空糸膜の場合、以下の条件を満足することにより、好適に得ることが出来る。
・中空糸膜形成ポリマー溶液中に塩化リチウム、塩化ナトリウムなど溶液中で解離度の高い電解質を１重量％以上含むこと。
・中空糸膜成型時、ポリマー溶液の口金部のドラフト比（凝固浴突入線速度／口金部吐出線速度）を５以上とし、かつ中空形成材として吐出する芯液のドラフト比を、１．５以下とすること。
・ポリマー溶液中のポリマー濃度を１５重量％以上とすること。
以上の３点により、本発明の選択分離膜が好適に得られる。
The method for producing the separation membrane of the present invention is not particularly limited, and can be produced in the form of a hollow fiber membrane or a flat membrane, but particularly in the case of a hollow fiber membrane, it is suitably obtained by satisfying the following conditions. I can do it.
-The hollow fiber membrane forming polymer solution contains 1% by weight or more of an electrolyte having a high degree of dissociation in the solution, such as lithium chloride and sodium chloride.
-At the time of hollow fiber membrane molding, the draft ratio of the base part of the polymer solution (solidification bath entry linear speed / base part discharge linear speed) is 5 or more, and the draft ratio of the core liquid discharged as the hollow forming material is 1.5. To be as follows.
-The polymer concentration in the polymer solution should be 15% by weight or more.
From the above three points, the selective separation membrane of the present invention is suitably obtained.
ここで、口金部吐出線速度とは、ポリマー溶液あるいは芯液の吐出量を、口金吐出部面積で割ったものである。凝固浴突入線速度は、実際に測定することは出来ないので、口金から吐出された中空糸の導かれる最初のローラー速度を指す。また、チューブインオリフィス型口金の場合、ポリマー溶液の吐出部面積は、スリット外側とスリット内側の間隙面積である。チューブインオリフィス型口金には、芯液を吐出するための孔があるが、吐出された芯液は直ちに、スリット内側まで拡張するため、芯液の口金吐出部面積とは、スリット内側面積である。 Here, the die part discharge linear velocity is obtained by dividing the discharge amount of the polymer solution or the core liquid by the die discharge part area. The solidification bath entry line speed refers to the initial roller speed at which the hollow fiber discharged from the die is guided because it cannot be actually measured. In the case of a tube-in-orifice die, the polymer solution discharge area is the gap area between the slit outer side and the slit inner side. The tube-in-orifice die has a hole for discharging the core liquid, but since the discharged core liquid immediately expands to the inside of the slit, the core liquid discharge part area is the area inside the slit. .
詳細な機構は不明であるが、ポリマー溶液中に電解質を含有させることにより、溶液中のポリマー分子同士の静電反発が抑制でき、更に、口金部のポリマー溶液のドラフト比を５以上にし、かつ芯液のドラフト比を１．５以下とし、ポリマー溶液中のポリマー濃度を１５重量％以上とすると、中空糸成型時に、ポリマー分子同士の絡み合いを強く持たせる効果があるものと考えられる。 Although the detailed mechanism is unknown, by containing an electrolyte in the polymer solution, electrostatic repulsion between the polymer molecules in the solution can be suppressed, and further, the draft ratio of the polymer solution in the base part is set to 5 or more, and When the draft ratio of the core liquid is 1.5 or less and the polymer concentration in the polymer solution is 15% by weight or more, it is considered that there is an effect of strongly entanglement of polymer molecules during hollow fiber molding.
以下に本発明について実施例を用いて具体的に説明する。 Hereinafter, the present invention will be specifically described with reference to examples.
（実施例１）
（中空糸およびモジュールの作製）
ポリアクリロニトリル系共重合体（分子量１７０，０００：アクリロニトリル９０重量％、メタリルスルホン酸１０重量％の共重合体）を２１重量％、塩化リチウム２重量％になるように、Ｎ−メチル−２−ピロリドン（ＮＭＰ）／ジメチルアセトアミド（ＤＭＡｃ）／トリエチレングリコール（ＴＥＧ）＝４５／４５／１０重量比の組成の混合溶媒に溶解させ、中空糸膜形成ポリマー溶液を得た。これをスリット内径２００μm、スリット外径８００μm、芯液吐出径１００μmのチューブインオリフィス型口金から２．０ｃｃ／分の割合で吐出した。このチューブインオリフィス型ノズルのポリマー溶液吐出部断面積は４．７×１０−７ｍ2で、芯液吐出部断面積は、３．１×１０−８ｍ2である。芯液は、ＮＭＰ／ＤＭＡｃ／ＴＥＧ＝４５／４５／１０の８５重量％水溶液を１．６ｃｃ／分の割合で吐出した。この時の、ポリマー溶液吐出線速度は、４．３ｍ／分であり、芯液吐出線速度は５０．９ｍ／分であった。これをエアギャップ２ｃｍでＮＭＰ／ＤＭＡｃ／ＴＥＧ＝４５／４５／１０の４０重量％水溶液の凝固液からなる４０℃の凝固浴に導き、凝固浴外部の速度５０ｍ／分のローラーに導いた。この時のポリマー溶液口金部のドラフト比は、１１．６（＝５０÷４．３）であり、芯液ドラフト比は、０．９８（＝５０÷５０．９）であった。その後、水洗してから巻取り、５０重量％のグリセリン水溶液に浸漬した後、乾燥して中空糸膜を得た。得られた中空糸膜は、内径２００μm、膜厚４０μmで、マクロボイドの観察されない均一な膜であった。
得られた中空糸膜１０８００本を束ねて、有効膜面積１．５ｍ2のモジュールを作製した。
(Example 1)
(Production of hollow fibers and modules)
A polyacrylonitrile-based copolymer (a copolymer having a molecular weight of 170,000: 90% by weight of acrylonitrile and 10% by weight of methallylsulfonic acid) is 21% by weight, and 2% by weight of lithium chloride is N-methyl-2- It was dissolved in a mixed solvent having a composition of pyrrolidone (NMP) / dimethylacetamide (DMAc) / triethylene glycol (TEG) = 45/45/10 weight ratio to obtain a hollow fiber membrane-forming polymer solution. This was discharged from a tube-in-orifice die having a slit inner diameter of 200 μm, a slit outer diameter of 800 μm, and a core liquid discharge diameter of 100 μm at a rate of 2.0 cc / min. The tube-in-orifice nozzle has a polymer solution discharge section sectional area of 4.7 × 10 −7 m 2 and a core liquid discharge section sectional area of 3.1 × 10 −8 m 2 . As the core liquid, an 85 wt% aqueous solution of NMP / DMAc / TEG = 45/45/10 was discharged at a rate of 1.6 cc / min. The polymer solution discharge linear velocity at this time was 4.3 m / min, and the core liquid discharge linear velocity was 50.9 m / min. This was led to a coagulation bath at 40 ° C. composed of a coagulating liquid of 40 wt% aqueous solution of NMP / DMAc / TEG = 45/45/10 with an air gap of 2 cm, and led to a roller outside the coagulation bath at a speed of 50 m / min. The draft ratio of the polymer solution base at this time was 11.6 (= 50 ÷ 4.3), and the core liquid draft ratio was 0.98 (= 50 ÷ 50.9). Thereafter, the film was washed with water, wound up, immersed in a 50% by weight glycerin aqueous solution, and then dried to obtain a hollow fiber membrane. The obtained hollow fiber membrane had an inner diameter of 200 μm and a thickness of 40 μm, and was a uniform membrane with no macrovoids observed.
10800 hollow fiber membranes thus obtained were bundled to produce a module having an effective membrane area of 1.5 m 2 .
（透水速度の測定）
透水速度の測定は、ダイアライザー性能評価基準（日本人工臓器学会、昭和５７年９月）のＣ法（ＳＴＯＰ法）に準拠して行った。
透水速度（ＵＦＲ）は以下の式で表される。
ＵＦＲ＝ＱＦ／Ａ／ＴＭＰ
上記の式において、ＱＦは濾過流量（ｍＬ／時）、Ａは膜面積（ｍ2）、ＴＭＰは膜間圧力差（ｍｍＨｇ）を示す。但し、膜間圧力差（ＴＭＰ）は、以下の式で求めた。
ＴＭＰ＝（ＰＢｉ＋ＰＢｏ）／２
ＰＢｉはダイアライザーの血液ないし原液の入口側圧力、ＰＢｏはダイアライザーの血液ないし原液の出口側圧力を示す。
ＴＭＰを４点変更し、その際の濾過流量（ＱＦ）を測定した。ＱＦとＴＭＰの関係をプロットし、傾きから透水速度を求めた。温度は３７±１℃とした。
純水中の透水速度（ＵＦＲ（Ｐ））は、純水としてイオン交換水を用いて未使用の中空糸膜モジュールについて測定した。生理食塩水中の透水速度（ＵＦＲ（Ｓ））は、ＵＦＲ（Ｐ）測定後に、イオン交換水に食塩を０．９重量％溶解した生理食塩水を用いて測定した。
実施例１で作製した中空糸膜モジュールの純水中の透水速度（ＵＦＲ（Ｐ））は、１８０ｍＬ／時／ｍ2／ｍｍＨｇであり、生理食塩水中の透水速度（ＵＦＲ（Ｓ））は、２１５ｍＬ／時／ｍ2／ｍｍＨｇ、ＵＦＲ（Ｓ）／ＵＦＲ（Ｐ）比は１．１９であった。
(Measurement of water permeability)
The water permeation rate was measured according to the C method (STOP method) of the dialyzer performance evaluation standard (Japan Artificial Organ Society, September 1982).
The water transmission rate (UFR) is expressed by the following equation.
UFR = QF / A / TMP
In the above formula, QF filtration flow rate (mL / hr), A is membrane area (m 2), TMP denotes transmembrane pressure difference (mmHg). However, the transmembrane pressure difference (TMP) was determined by the following equation.
TMP = (PBi + PBo) / 2
PBi represents the pressure on the inlet side of the blood or stock solution of the dialyzer, and PBo represents the pressure on the outlet side of the blood or stock solution of the dialyzer.
Four points of TMP were changed, and the filtration flow rate (QF) at that time was measured. The relationship between QF and TMP was plotted, and the water transmission rate was determined from the slope. The temperature was 37 ± 1 ° C.
The water permeation rate (UFR (P)) in pure water was measured for unused hollow fiber membrane modules using ion-exchanged water as pure water. The water permeation rate (UFR (S)) in physiological saline was measured using a physiological saline in which 0.9% by weight of sodium chloride was dissolved in ion-exchanged water after the measurement of UFR (P).
The water permeation rate (UFR (P)) in pure water of the hollow fiber membrane module produced in Example 1 is 180 mL / hour / m 2 / mmHg, and the water permeation rate (UFR (S)) in physiological saline is 215 mL / hr / m 2 / mmHg, UFR (S) / UFR (P) ratio was 1.19.
（透水速度の可逆性の評価）
上記のＵＦＲ（Ｐ）とＵＦＲ（Ｓ）を測定した後、もう一度、上記の方法で純水中の透水速度ＵＦＲ（Ｐ）を測定した。２回目のＵＦＲ（Ｐ）の測定値は１８０ｍＬ／時／ｍ2／ｍｍＨｇであり、透水速度は可逆的に最初の測定値に戻っていた。
(Evaluation of reversibility of water transmission rate)
After measuring the above UFR (P) and UFR (S), the water permeation rate UFR (P) in pure water was measured once again by the above method. The measurement value of the second UFR (P) was 180 mL / hour / m 2 / mmHg, and the water permeation rate reversibly returned to the first measurement value.
（牛血液を用いた透水速度の経時劣化性と回復性の評価）
牛血液（ヘマトクリット３０％、総タンパク質濃度６．５ｇ／ｄＬ）を用い、温度３７±１℃、血液側流量２００ｍＬ／分、濾過流量４０ｍＬ／分で、１２０分間、血液濾過実験を行った。血液濾過開始から１５分後の膜間圧力差ＴＭＰ（１５）と１２０分後における膜間圧力差ＴＭＰ（１２０）から、下式に示すＣ％の値を求めた。
Ｃ％＝ＴＭＰ（１２０）×１００／ＴＭＰ（１５）
中空糸膜モジュールが経時劣化しない場合は、Ｃ％の値は１００％である。Ｃ％の値が大きくなるほど経時劣化が大きいことを示す。
実施例１の中空糸膜モジュールについて血液濾過開始後１５分後のＴＭＰ（１５）は４７ｍｍＨｇ、１２０分後のＴＭＰ（１２０）は５２ｍｍＨｇ、Ｃ％は１１１％であった。
血液濾過実験終了後、ダイアライザーを回路から外し、透析液側から血液側に向け、イオン交換水を５００ｍＬ／分の割合で１０分間通して逆洗した。逆洗後の純水の透水速度を求めたところ、ＵＦＲ（Ｐ）は１７２ｍＬ／時／ｍ2／ｍｍＨｇであり、血液処理前に比べ９５．５％の回復率であった。
(Evaluation of deterioration over time and recovery of water permeability using bovine blood)
A blood filtration experiment was performed for 120 minutes using bovine blood (hematocrit 30%, total protein concentration 6.5 g / dL) at a temperature of 37 ± 1 ° C., a blood flow rate of 200 mL / min, and a filtration flow rate of 40 mL / min. From the transmembrane pressure difference TMP (15) 15 minutes after the start of blood filtration and the transmembrane pressure difference TMP (120) after 120 minutes, the value of C% shown in the following formula was obtained.
C% = TMP (120) × 100 / TMP (15)
When the hollow fiber membrane module does not deteriorate with time, the value of C% is 100%. It shows that deterioration with time is greater as the value of C% increases.
Regarding the hollow fiber membrane module of Example 1, TMP (15) 15 minutes after the start of blood filtration was 47 mmHg, TMP (120) after 120 minutes was 52 mmHg, and C% was 111%.
After completion of the blood filtration experiment, the dialyzer was removed from the circuit, and ion-exchanged water was passed back at a rate of 500 mL / min for 10 minutes from the dialysate side to the blood side for backwashing. When the water permeation rate of the pure water after backwashing was determined, UFR (P) was 172 mL / hour / m 2 / mmHg, which was a recovery rate of 95.5% compared to before blood treatment.
（比較例１）
ポリアクリロニトリル系共重合体（分子量１７０，０００：アクリロニトリル９０重量％、メタリルスルホン酸１０重量％の共重合体）を２１重量％になるように、Ｎ−メチル−２−ピロリドン（ＮＭＰ）／ジメチルアセトアミド（ＤＭＡｃ）／トリエチレングリコール（ＴＥＧ）＝４５／４５／１０重量比の組成の混合溶媒に溶解させ、中空糸膜形成ポリマー溶液を得た。これをスリット内径２５０μm、スリット外径４００μm、芯液吐出径１５０μmのチューブインオリフィス型口金から２．０ｃｃ／分の割合で吐出した。このチューブインオリフィス型ノズルのポリマー溶液吐出部断面積は７．７×１０−８ｍ2で、芯液吐出部断面積は、４．９×１０−８ｍ2である。芯液は、ＮＭＰ／ＤＭＡｃ／ＴＥＧ＝４５／４５／１０の８５重量％水溶液を１．６ｃｃ／分の割合で吐出した。この時のポリマー溶液吐出線速度は、２６．１ｍ／分であり、芯液吐出線速度は３２．６ｍ／分であった。これをエアギャップ２ｃｍでＮＭＰ／ＤＭＡｃ／ＴＥＧ＝４５／４５／１０の４０重量％水溶液の凝固液からなる４０℃の凝固浴に導き、凝固浴外部の速度５０ｍ／分のローラーに導いた。この時のポリマー溶液口金部のドラフト比は、１．９２（＝５０÷２６．１）、芯液のドラフト比は、１．５３（＝５０÷３２．６）であった。その後、水洗してから巻取り、５０重量％のグリセリン水溶液に浸漬した後、乾燥して中空糸膜を得た。得られた中空糸膜は、内径２００μm、膜厚４０μmで、マクロボイドの観察されない均一な膜であった。
得られた中空糸膜１０８００本を束ねて、有効膜面積１．５ｍ2のモジュールを作製した。
(Comparative Example 1)
N-methyl-2-pyrrolidone (NMP) / dimethyl so that the polyacrylonitrile-based copolymer (molecular weight 170,000: copolymer of 90% by weight of acrylonitrile and 10% by weight of methallylsulfonic acid) is 21% by weight. It was dissolved in a mixed solvent having a composition of acetamide (DMAc) / triethylene glycol (TEG) = 45/45/10 weight ratio to obtain a hollow fiber membrane-forming polymer solution. This was discharged from a tube-in-orifice die having a slit inner diameter of 250 μm, a slit outer diameter of 400 μm, and a core liquid discharge diameter of 150 μm at a rate of 2.0 cc / min. The tube-in-orifice nozzle has a polymer solution discharge section sectional area of 7.7 × 10 −8 m 2 and a core liquid discharge section sectional area of 4.9 × 10 −8 m 2 . As the core liquid, an 85 wt% aqueous solution of NMP / DMAc / TEG = 45/45/10 was discharged at a rate of 1.6 cc / min. The polymer solution discharge linear velocity at this time was 26.1 m / min, and the core liquid discharge linear velocity was 32.6 m / min. This was led to a coagulation bath at 40 ° C. composed of a coagulating liquid of 40 wt% aqueous solution of NMP / DMAc / TEG = 45/45/10 with an air gap of 2 cm, and led to a roller outside the coagulation bath at a speed of 50 m / min. At this time, the draft ratio of the polymer solution base was 1.92 (= 50 ÷ 26.1), and the draft ratio of the core solution was 1.53 (= 50 ÷ 32.6). Thereafter, the film was washed with water, wound up, immersed in a 50% by weight glycerin aqueous solution, and then dried to obtain a hollow fiber membrane. The obtained hollow fiber membrane had an inner diameter of 200 μm and a thickness of 40 μm, and was a uniform membrane with no macrovoids observed.
10800 hollow fiber membranes thus obtained were bundled to produce a module having an effective membrane area of 1.5 m 2 .
得られた中空糸膜モジュールを実施例１と同様に評価した結果、ＵＦＲ（Ｐ）は２０５ｍＬ／分、ＵＦＲ（Ｓ）は２０３ｍＬ／分、ＵＦＲ（Ｓ）／ＵＦＲ（Ｐ）比は０．９９であった。ＵＦＲ（Ｓ）／ＵＦＲ（Ｐ）比は、被処理液の粘度に依存した変化であり、膜構造は変化していないと考えられた。２回目に測定したＵＦＲ（Ｐ）は２０５ｍＬ／時／ｍ2／ｍｍＨｇであった。
血液濾過実験では、ＴＭＰ（１５）は５２ｍｍＨｇで、ＴＭＰ（１２０）は９０ｍｍＨｇであり、Ｃ％は１７３％であった。実施例１に比べ、初期から高いＴＭＰ値を持ち、またＣ％も大きい値であり、血液中の成分による膜の性能低下および経時劣化が激しいことがわかる。
実施例１と同様に逆洗した後に測定した純水中の透水速度（ＵＦＲ（Ｐ））は１３１ｍＬ／時／ｍ2／ｍｍＨｇであり、血液処理前に比較した回復率は６３．９％であり、実施例１に比べ、中空糸膜の性能の回復率が低かった。
The obtained hollow fiber membrane module was evaluated in the same manner as in Example 1. As a result, UFR (P) was 205 mL / min, UFR (S) was 203 mL / min, and UFR (S) / UFR (P) ratio was 0.99. Met. The UFR (S) / UFR (P) ratio was a change depending on the viscosity of the liquid to be treated, and it was considered that the film structure did not change. The UFR (P) measured at the second time was 205 mL / hour / m 2 / mmHg.
In blood filtration experiments, TMP (15) was 52 mmHg, TMP (120) was 90 mmHg, and C% was 173%. Compared to Example 1, it has a high TMP value from the beginning, and C% is also a large value, and it can be seen that membrane performance deterioration and deterioration with time due to components in blood are severe.
The water permeation rate (UFR (P)) in pure water measured after backwashing as in Example 1 was 131 mL / hr / m 2 / mmHg, and the recovery rate compared to before blood treatment was 63.9%. Yes, compared with Example 1, the recovery rate of the performance of the hollow fiber membrane was low.
本発明の選択分離膜は、処理中の経時的な性能低下が少なく、かつ、一旦低下した性能を容易に回復することができる。従って、蛋白質が高濃度に存在する液の処理に用いる血液浄化膜や、懸濁成分が高濃度に存在する廃水および水道水処理膜などの選択分離膜等として有用である。
The selective separation membrane of the present invention is less susceptible to performance degradation over time during processing and can easily recover performance once degraded. Therefore, it is useful as a blood separation membrane used for the treatment of a liquid in which protein is present at a high concentration, a selective separation membrane such as a waste water and tap water treatment membrane in which a suspended component is present at a high concentration, and the like.
Claims (2)
ＵＦＲ（Ｓ）／ＵＦＲ（Ｐ）≧ １．０７ At the time of molding a hollow fiber membrane made of a polymer selected from a polyacrylonitrile copolymer, polymethyl methacrylate, and ethylene vinyl alcohol copolymer , the polymer concentration in the polymer solution is 15% by weight or more, and the electrolyte is contained by 1% by weight or more, By setting the draft ratio of the base part of the polymer solution (solidification bath entry linear speed / base part discharge linear speed) to 5 or more and the draft ratio of the core liquid discharged as the hollow forming material to 1.5 or less, the membrane structure Is a substantially uniform film in which no macrovoids are observed, and the film thickness is in the range of 10 to 50 μm. The water permeability (UFR (S)) in physiological saline and the water permeability in pure water A method for producing a selective separation membrane in which a selective separation membrane in which the ratio of (UFR (P)) satisfies the following formula is obtained .
UFR (S) / UFR (P) ≧ 1.07
The film cross-section when observed at 1000 times by a scanning electron microscope, to claim 1, characterized in that indicating the uniform structure is not observed voids derived from more than the size of voids or sponge structure 0.5μm diameter The manufacturing method of the selective separation membrane of description.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007321746A JP4164774B2 (en) | 2007-12-13 | 2007-12-13 | Method for producing selective separation membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007321746A JP4164774B2 (en) | 2007-12-13 | 2007-12-13 | Method for producing selective separation membrane |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001230259A Division JP4164730B2 (en) | 2001-07-30 | 2001-07-30 | Selective separation membrane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2008137004A JP2008137004A (en) | 2008-06-19 |
| JP4164774B2 true JP4164774B2 (en) | 2008-10-15 |
Family
ID=39599013
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2007321746A Expired - Fee Related JP4164774B2 (en) | 2007-12-13 | 2007-12-13 | Method for producing selective separation membrane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4164774B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011050881A (en) * | 2009-09-02 | 2011-03-17 | Toyobo Co Ltd | Method of spinning hollow fiber membrane |
-
2007
- 2007-12-13 JP JP2007321746A patent/JP4164774B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2008137004A (en) | 2008-06-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2458378C (en) | Porous membrane and method of manufacturing the same | |
| JP5622833B2 (en) | High durability PVDF porous membrane, method for producing the same, and cleaning method and filtration method using the same | |
| JP6694326B2 (en) | Composite membrane | |
| US10406487B2 (en) | Hydrophilised vinylidene fluoride-based porous hollow fibre membrane, and manufacturing method therefor | |
| CN105636677B (en) | Improve the chemical stability of filter membrane | |
| US8794451B2 (en) | Hollow-fiber ultrafiltration membrane with excellent fouling resistance | |
| JP4931796B2 (en) | Vinylidene fluoride resin hollow fiber porous membrane, water filtration method using the same, and production method thereof | |
| Fang et al. | Evaluating the antifouling properties of poly (ether sulfone)/sulfonated poly (ether sulfone) blend membranes in a full-size membrane module | |
| JP5952159B2 (en) | Separation membrane and manufacturing method thereof | |
| KR101790174B1 (en) | A PVA coated hollow fiber mambrane and a preparation method thereof | |
| JP4164730B2 (en) | Selective separation membrane | |
| JP4164774B2 (en) | Method for producing selective separation membrane | |
| JP3317975B2 (en) | Polyacrylonitrile hollow fiber filtration membrane | |
| JP4103037B2 (en) | Diaphragm cleaning hollow fiber membrane and method for producing the same | |
| WO1996035504A1 (en) | Hollow-fiber membrane of polysulfone polymer and process for the production thereof | |
| KR20160080376A (en) | Hollow fiber type Forward Osmosis filtration membrane and the manufacturing method thereby | |
| WO2016182015A1 (en) | Porous hollow fiber membrane and manufacturing method therefor | |
| KR20120077011A (en) | Water treatment membrane of poly(ethylenechlorotrifluoroethylene) and manufacturing method thereof | |
| JP2688564B2 (en) | Cellulose acetate hollow fiber separation membrane | |
| JP6707880B2 (en) | Hollow fiber membrane and hollow fiber membrane module | |
| KR20120007277A (en) | Hollow fiber membrane of poly(ethylenechlorotrifluoroethylene) with enhanced water permeability and manufacturing method thereof | |
| SG188687A1 (en) | Thin film composite osmosis membranes | |
| JP6649779B2 (en) | Hollow fiber type semipermeable membrane and method for producing the same | |
| WO2019172077A1 (en) | Hollow-fiber membrane and method for producing hollow-fiber membrane | |
| JP6533064B2 (en) | Hollow fiber type semipermeable membrane and method for producing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080410 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080606 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20080703 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080716 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 4164774 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110808 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110808 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120808 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130808 Year of fee payment: 5 |
|
| LAPS | Cancellation because of no payment of annual fees |