JPS6356802B2 - - Google Patents
Info
- Publication number
- JPS6356802B2 JPS6356802B2 JP56212567A JP21256781A JPS6356802B2 JP S6356802 B2 JPS6356802 B2 JP S6356802B2 JP 56212567 A JP56212567 A JP 56212567A JP 21256781 A JP21256781 A JP 21256781A JP S6356802 B2 JPS6356802 B2 JP S6356802B2
- Authority
- JP
- Japan
- Prior art keywords
- hollow fiber
- polysulfone
- fiber membrane
- membrane
- peg
- 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
Links
- 239000012528 membrane Substances 0.000 claims description 116
- 239000012510 hollow fiber Substances 0.000 claims description 78
- 229920002492 poly(sulfone) Polymers 0.000 claims description 65
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 63
- 239000011148 porous material Substances 0.000 claims description 26
- 239000000126 substance Substances 0.000 claims description 14
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 6
- 238000005056 compaction Methods 0.000 claims description 5
- 239000007864 aqueous solution Substances 0.000 claims description 3
- 239000012466 permeate Substances 0.000 claims description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 53
- 229920001223 polyethylene glycol Polymers 0.000 description 53
- 239000011550 stock solution Substances 0.000 description 35
- 238000000034 method Methods 0.000 description 24
- 239000007788 liquid Substances 0.000 description 23
- 230000035699 permeability Effects 0.000 description 21
- 239000002904 solvent Substances 0.000 description 21
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 17
- 238000009987 spinning Methods 0.000 description 16
- 238000005345 coagulation Methods 0.000 description 13
- 230000015271 coagulation Effects 0.000 description 13
- 238000005191 phase separation Methods 0.000 description 13
- 229920000642 polymer Polymers 0.000 description 11
- 239000000243 solution Substances 0.000 description 10
- 230000007423 decrease Effects 0.000 description 9
- 239000002002 slurry Substances 0.000 description 9
- 239000002245 particle Substances 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 239000012888 bovine serum Substances 0.000 description 7
- 238000001816 cooling Methods 0.000 description 7
- 238000001891 gel spinning Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 108010074605 gamma-Globulins Proteins 0.000 description 6
- 239000002510 pyrogen Substances 0.000 description 6
- 241000239218 Limulus Species 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 238000001914 filtration Methods 0.000 description 5
- 238000005194 fractionation Methods 0.000 description 5
- 239000012456 homogeneous solution Substances 0.000 description 5
- 239000008399 tap water Substances 0.000 description 5
- 235000020679 tap water Nutrition 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 230000001112 coagulating effect Effects 0.000 description 4
- 239000008119 colloidal silica Substances 0.000 description 4
- 238000007596 consolidation process Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000002158 endotoxin Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000011259 mixed solution Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 238000000108 ultra-filtration Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 230000007717 exclusion Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000003607 modifier Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- 238000002166 wet spinning Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000000578 dry spinning Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 230000005764 inhibitory process Effects 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 230000036555 skin type Effects 0.000 description 2
- 230000008961 swelling Effects 0.000 description 2
- 206010003445 Ascites Diseases 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 108010044091 Globulins Proteins 0.000 description 1
- 102000006395 Globulins Human genes 0.000 description 1
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 1
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 238000011001 backwashing Methods 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 210000004369 blood Anatomy 0.000 description 1
- 239000008280 blood Substances 0.000 description 1
- 210000001124 body fluid Anatomy 0.000 description 1
- 239000010839 body fluid Substances 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 229940113088 dimethylacetamide Drugs 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 102000034238 globular proteins Human genes 0.000 description 1
- 108091005896 globular proteins Proteins 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 229920006008 lipopolysaccharide Polymers 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- IQZPDFORWZTSKT-UHFFFAOYSA-N nitrosulphonic acid Chemical compound OS(=O)(=O)[N+]([O-])=O IQZPDFORWZTSKT-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 239000003495 polar organic solvent Substances 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 125000001453 quaternary ammonium group Chemical group 0.000 description 1
- 238000001223 reverse osmosis Methods 0.000 description 1
- 230000028327 secretion Effects 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000007614 solvation Methods 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Artificial Filaments (AREA)
Description
本発明はポリスルホン中空繊維膜に関する。
近年、分離操作において選択的な透過性を有す
る膜を用いる技術がめざましく進展しつつあり、
かなりの分野で実用化されつつある。特に膜の形
状が中空繊維であると、占有体積あたりの膜面積
が多くとれ有利であり実用化例が増加しつつあ
る。またこの選択透過性分離膜の膜素材としては
多種類のポリマーが研究開発され、セルロース
系、ポリアミド系、ポリアクリロニトリル系、ポ
リビニルアルコール系などのポリマーが使用され
ている。ポリスルホン系ポリマーは耐熱性、耐酸
性、耐アルカリ性、耐酸化性などの物理的及び化
学的性質が優れているため、限外過用の膜素材
として、また逆浸透用や気体分離用複合膜の支持
体として注目され検討されている。限外過用ポ
リスルホン中空繊維としてはアミコン社よりHP
シリーズとして市販されている。この中空繊維は
内表面に緻密なスキン層を有し、外表面には10μ
以上のマクロポアが多数存在し、かつ膜内部はフ
インガーライク構造で空孔率が大きいため、透水
性はかなり高いものもあるが、耐圧性が低く、医
慮用や実験用には使用しうるが、工業用に長期使
用することは困難である。また特開昭54−145379
には内表面及び外表面に10〜100Åの微細孔を有
し、膜内部にいくに従つて徐々に細孔が大きくな
る傾斜型の両面スキンタイプのポリスルホン中空
繊維が記載されている。これは両面にスキン層が
あるためか、または内部構造のポアの連続性が低
いためか、膜厚が100μ以上では透水性が急激に
低下する傾向があり、実質的には膜厚が100μ以
下とならざるを得ず、従つて耐圧性を考慮すると
内径は200μ程度となり、工業用に使用するには
内径が小さく圧力損失が大きい。また特開昭56−
105704、56−115602には膜の両面に顕微鏡的に観
察し得る程度の小孔又は開孔部をもたない両面ス
キンタイプで内部構造が管束状構造、いわゆるフ
インガーライク構造であるポリスルホン中空繊維
が記載されている。これらの膜占有体積あたりの
透水速度はせいぜい500／m2・hr・Kg／cm2であ
り、ある一定の筐体に出来るだけ多く中空繊維を
詰め込んだ場合の筐体あたりの透水性が不十分で
ある。その他各種の中空繊維膜の製造法も知られ
ているが、工業用に使用することができ、透水速
度の大きく、かつ限外過オーダーの分画性を有
する中空繊維膜は知られていないのが現状であ
る。
このような状況に鑑み、鋭意努力の結果本発明
に達した。
すなわち本発明は内表面に平均巾80〜500Åの
スリツト状微細隙を有し、外表面に平均孔径1500
〜3500Åの微孔を開孔率10〜50％の割合で有し、
膜内部が微細多孔構造であり、かつ80Å以上の物
質を実質的に透過させず、透水速度が700〜6000
／m2・hr・Kg／cm2を示すポリスルホン中空繊維
膜である。
本発明のポリスルホン中空繊維膜は後述する実
施例からも明らかなように透水速度が優れている
のみならず、パイロジエン物質を実質的に阻止す
るなど分画性が限外過オーダーと優れており、
さらにまた圧密化指数0.2以下というきわめて耐
圧性、耐熱性の優れたものである。
本発明のポリスルホン中空繊維膜は、その内表
面に平均巾80〜500Åのスリツト状微細隙を有す
る必要がある。ここでスリツト状微細隙とは繊維
の縦方向に細長く存在する微細隙であり、平均巾
とはその微細隙の短径の平均的値である。この微
細隙の繊維の縦方向の長さはとくに限定されるも
のではなく、スリツト巾の３倍以上、好ましくは
10倍以上である。また微細隙の内表面における分
布密度はできるだけ均一で、しかも高い方が好ま
しい。また微細隙の巾もできるだけ均一であるこ
とが、優れた分画性、優れた耐圧性を示すので好
ましい。また微細隙の平均巾は走査型電子顕微鏡
写真により測定されるが、この平均巾が500Åを
こえると分画性が大きくなりすぎて好ましくな
い。平均巾が100〜200Åであると透水性と分画性
のバランスの点でさらに好ましい傾向を示す。ま
た内表面をスリツト状微細隙構造とすることは、
円形状の微細多孔構造とすることにくらべ透水性
が大きいという特長を有する。
次に本発明のポリスルホン中空繊維膜はその外
表面に平均孔径1500〜3500Åの微孔を開孔率10〜
50％の割合で有する必要がある。ここで外表面の
微孔の平均孔径とは、
（ここで：平均孔径
Di；ｉ個目の微孔の実測径
Do：ｎ個の微孔の実測径
なおDi、Doの実測径は微孔が円形に近い場合
はその直径を示し、微孔が円形でない場合には、
その微孔と同一面積の円の直径を示す。）
で示されるものである。外表面の平均孔径が1500
Å未満であると透水速度が小さくなり過ぎる。平
均孔径が3500Åを越えると耐圧性が低くなる傾向
があり好ましくない。また外圧過の場合、大き
な滓が膜内部にまで侵入してくることとなり、
透過速度の低下が早いばかりでなく、逆洗あるい
は薬洗によつても膜の再生が十分にはできない傾
向にあり、好ましくない。なお本発明の場合、
500Å以下の微細孔は平均孔径の計算には含まれ
ていない。ただし500Å以下の微細孔が本発明の
目的、効果を損なわない程度に存在していてもよ
い。また外表面の微孔は均一孔径であることが好
ましいが、とくに均一である必要はなく、不均一
であつてもよい。本発明にいう開孔率とは外表面
に開孔している微孔の全孔面積の外表面積に対す
る割合を百分率で示したものである。開孔率が10
％未満であると透水率が低いので好ましくない。
開孔率が50％を越えると表面強度が小さくなり、
取扱い時、膜が損傷し易いので好ましくない。開
孔率が20〜40％であると膜の透過性能と機械的性
能のバランスの点でさらに好ましい。
本発明において、膜内部は微細多孔構造となつ
ており、ここで微細多孔構造とは網目状構造、ハ
ニカム構造、微細間隙構造などのスポンジ構造で
ある。また膜内外表面および膜内部にはフインガ
ーライク状構造あるいはマクロボイド構造があつ
てもよいが10μ以上の巨大空洞は実質的に存在し
ない方が好ましい。このような10μ以上の巨大空
洞のない均一スポンジ構造のものは耐圧性、とく
に長期間使用時における圧密化性が優れ、さらに
強度も優れている。
膜内部の微細多孔構造の孔径はより均一である
ことが好ましいが、とくに均一である必要はな
く、不均一であつてもよい。またその孔径は膜の
外表面の孔径と同じか、あるいはそれより多少大
きめ、あるいは小さめであつてもよい。また膜内
部の数細多孔構造は膜の内表面および外表面を支
持する機能を有するとともに排除率や透水速度に
も影響を及ぼすものである。
本発明にいうポリスルホンとは次の一般式(A)又
は(B)を繰り返しユニツトとするポリマーである。
但しＸ、X′、Ｙ、Y′はベンゼン環の置換基を
示し、たとえば水素、メチル、ハロゲン、ニト
ロ、スルホン酸（又はその塩）、カルボン酸（又
はその塩）、第４級アンモニウム（又はその塩）
などである。ａ、ｂ、ｃ、ｄは０〜４の整数を示
す。Ｒは二価の有機残基を示し、たとえば
The present invention relates to polysulfone hollow fiber membranes. In recent years, the technology of using membranes with selective permeability in separation operations has made remarkable progress.
It is being put into practical use in many fields. In particular, when the shape of the membrane is hollow fiber, the membrane area per occupied volume is large, which is advantageous, and examples of its practical use are increasing. Many types of polymers have been researched and developed as membrane materials for this permselective separation membrane, and polymers such as cellulose, polyamide, polyacrylonitrile, and polyvinyl alcohol are used. Polysulfone polymers have excellent physical and chemical properties such as heat resistance, acid resistance, alkali resistance, and oxidation resistance, so they are used as membrane materials for ultrafiltration and for composite membranes for reverse osmosis and gas separation. It is attracting attention and being considered as a support. As a polysulfone hollow fiber for ultraviolet rays, HP is available from Amicon.
It is sold as a series. This hollow fiber has a dense skin layer on the inner surface and a 10 μm layer on the outer surface.
There are many macropores as described above, and the inside of the membrane has a finger-like structure with high porosity, so the water permeability is quite high, but the pressure resistance is low and it cannot be used for medical or experimental purposes. However, it is difficult to use it for long periods of time industrially. Also, JP-A-54-145379
describes a slanted, double-sided skin type polysulfone hollow fiber that has micropores of 10 to 100 Å on the inner and outer surfaces, and the pores gradually become larger as they go inside the membrane. This may be because there are skin layers on both sides or because the continuity of the pores in the internal structure is low.Water permeability tends to decrease rapidly when the film thickness is 100μ or more, and in reality, the water permeability tends to decrease when the film thickness is 100μ or less. Therefore, considering pressure resistance, the inner diameter is about 200μ, and the inner diameter is too small for industrial use, resulting in a large pressure loss. Also, JP-A-56-
105704 and 56-115602 are polysulfone hollow fibers that have a double-sided skin type without microscopically observable pores or openings on both sides of the membrane, and whose internal structure is a tube bundle-like structure, a so-called finger-like structure. is listed. The water permeability rate per occupied volume of these membranes is at most 500/m 2 hr Kg/cm 2 , and the water permeability per casing is insufficient when as many hollow fibers as possible are packed into a certain casing. It is. Although various other methods for producing hollow fiber membranes are known, there is no known hollow fiber membrane that can be used for industrial purposes, has a high water permeation rate, and has a fractionation property on the order of ultrafiltration. is the current situation. In view of this situation, the present invention has been achieved as a result of diligent efforts. That is, the present invention has slit-like micropores with an average width of 80 to 500 Å on the inner surface, and pores with an average diameter of 1500 Å on the outer surface.
It has ~3500Å micropores with a porosity of 10~50%,
The inside of the membrane has a microporous structure and does not substantially allow substances larger than 80 Å to pass through, and the water permeation rate is 700 to 6000.
/m 2 ·hr · Kg/cm 2 It is a polysulfone hollow fiber membrane. As is clear from the examples described below, the polysulfone hollow fiber membrane of the present invention not only has an excellent water permeation rate, but also has an excellent fractionation property of the ultrafiltration order, such as substantially blocking pyrodiene substances,
Furthermore, it has excellent pressure resistance and heat resistance, with a consolidation index of 0.2 or less. The polysulfone hollow fiber membrane of the present invention must have slit-like micropores with an average width of 80 to 500 Å on its inner surface. Here, the slit-like micropores are micropores that are elongated in the longitudinal direction of the fiber, and the average width is the average value of the short diameter of the micropores. The length in the longitudinal direction of the fibers in this fine gap is not particularly limited, and is preferably at least three times the slit width.
It is more than 10 times. Further, it is preferable that the distribution density on the inner surface of the micropores be as uniform as possible and as high as possible. Further, it is preferable that the width of the micropores is as uniform as possible, since this shows excellent fractionation properties and excellent pressure resistance. Further, the average width of the micropores is measured by scanning electron micrographs, and if this average width exceeds 500 Å, fractionation becomes too large, which is not preferable. An average width of 100 to 200 Å tends to be more favorable in terms of the balance between water permeability and fractionability. In addition, creating a slit-like microporous structure on the inner surface
It has a feature of higher water permeability than a circular microporous structure. Next, the polysulfone hollow fiber membrane of the present invention has micropores with an average pore diameter of 1500 to 3500 Å on its outer surface, and a porosity of 10 to 10.
Must have at a rate of 50%. Here, the average pore diameter of the micropores on the outer surface is (Here: Average pore diameter D i ; Actual diameter of the i-th pore Do: Actual diameter of n pores Note that the actual diameters of D i and D o are the diameters of the pores when they are close to circular. and if the pores are not circular,
It shows the diameter of a circle with the same area as the micropore. ). Average pore size on outer surface is 1500
If it is less than Å, the water permeation rate will be too low. If the average pore diameter exceeds 3500 Å, pressure resistance tends to decrease, which is not preferable. In addition, in the case of excessive external pressure, large slag will penetrate into the membrane.
Not only does the permeation rate decrease rapidly, but also the membrane tends to be unable to be regenerated sufficiently even by backwashing or chemical washing, which is undesirable. In the case of the present invention,
Micropores smaller than 500 Å are not included in the calculation of average pore size. However, micropores of 500 Å or less may be present to the extent that the objects and effects of the present invention are not impaired. Further, although it is preferable that the micropores on the outer surface have a uniform diameter, they do not need to be particularly uniform and may be non-uniform. The porosity referred to in the present invention is the ratio of the total pore area of micropores opened on the outer surface to the outer surface area, expressed as a percentage. Open area ratio is 10
If it is less than %, the water permeability will be low, which is not preferable.
When the porosity exceeds 50%, the surface strength decreases,
This is not preferred because the membrane is easily damaged during handling. A porosity of 20 to 40% is more preferable in terms of the balance between permeability and mechanical performance of the membrane. In the present invention, the inside of the membrane has a microporous structure, and the microporous structure here refers to a sponge structure such as a network structure, a honeycomb structure, and a microporous structure. Although finger-like structures or macrovoid structures may be present on the inner and outer surfaces of the membrane and inside the membrane, it is preferable that giant cavities of 10 μm or more are substantially absent. Such a uniform sponge structure without large cavities of 10μ or more has excellent pressure resistance, especially compactability during long-term use, and is also excellent in strength. Although the pore diameter of the microporous structure inside the membrane is preferably more uniform, it is not particularly necessary to be uniform and may be non-uniform. Further, the pore size may be the same as the pore size on the outer surface of the membrane, or may be slightly larger or smaller than that. In addition, the multi-pore structure inside the membrane has the function of supporting the inner and outer surfaces of the membrane, and also influences the exclusion rate and water permeation rate. The polysulfone referred to in the present invention is a polymer having the following general formula (A) or (B) as a repeating unit. However, X, X', Y, and Y' represent substituents on the benzene ring, such as hydrogen, methyl, halogen, nitro, sulfonic acid (or its salt), carboxylic acid (or its salt), quaternary ammonium (or the salt)
etc. a, b, c, and d represent integers of 0 to 4. R represents a divalent organic residue, for example
【式】などである。ＺはＯ又はSO2を示す。
一般的には(A)式でａ、ｂ、ｃ、ｄが０、Ｒが
[Formula] etc. Z represents O or SO2 . Generally, in formula (A), a, b, c, d are 0, and R is
【式】ＺがＯで示されるもの、たとえばユニ
オンカーバイド社製の「Udel」が工業的には最
も使い易い。
さらに本発明のポリスルホン中空繊維膜は前述
のような構造を有するとともに、透水率か700〜
6000／m2・hr・Kg／cm2を示すものである。
本発明のポリスルホン中空繊維膜の内径は250
〜1500μ、外径は350〜3000μ、好ましくは内径が
300〜1000μ、外径が400〜2000μ、さらに好まし
くは内径が350〜700μ、外径が500〜1200μである
と、膜面積あたりの透水速度及び耐圧性が優れ、
さらにその他の膜性能のバランスも向上する。
本発明にいう透水速度は中空繊維の膜面積あた
りの透水速度KAをいい、次の方法で測定する。
透水速度KAの測定方法；
(i) 中空繊維膜束；中空繊維長20cm、外径基準の
膜面積200cm2の新品の中空繊維膜束。
(ii) 過；温度25℃の純水を外圧全過方式によ
り、圧力１Kg／cm2で過した時の透水速度
（／m2・hr・Kg／cm2）KAを測定する。
本発明のポリスルホン中空繊維膜の透水速度
KAは700〜6000／m2・hr・Kg／cm2である。
なおKAが6000／m2・hr・Kg／cm2以上の中空
繊維膜は現状技術においては後述する排除率Ｒが
小さいものしか得られないので実際的でない。
また本発明のポリスルホン中空繊維膜は80Å以
上の物質を実質的に透過させないものである。こ
こで80Å以上の物質を実質的に透過させないとは
平均粒径が80Åのコロイダルシリカの排除率Ｒを
次の条件で測定し、Ｒが95％以上のものをいう。
排除率の測定方法
(i) 中空繊維膜束；中空糸長20cm、外径基準の膜
面積200cm2の中空繊維膜束を作製し使用。
(ii) 測定液；平均粒径80Åのコロイダルシリカ１
％液｛日産化学工業株式会社製スノーテツクス
−Ｓ（コロイダルシリカで最小粒径のもの）を
蒸留水にて稀釈｝。
(iii) 過条件；外圧全過方式、過圧0.5Kg／
cm2、温度25℃。なお中空繊維膜束は使用前によ
く水をきり、かつ中空糸膜壁内もコロイダルシ
リカ液に置換後、加圧し、過を開始する。
(iv) サンプリング；加圧直前の測定原液及び加圧
後の液の初流より10c.c.毎に５回サンプリング
する。得られた６コのサンプルを100℃×16hr
乾燥し、固型分濃度を測定する。
(v) 排除率Ｒの算出；測定原液の固型分濃度CD
と５個の液中で最も高い固型分濃度CFmax
より次式によりＲを求める。
Ｒ＝（１−CFmax／CD）×100
なお本測定法の如く、コロイド液を用いると粒
子以外の溶解物質を含有している可能性があり、
Ｒを重量法で求めるため、Ｒが97％と出ても、80
Åの粒子が３％透過していることを意味しておら
ず、Ｒが95％以上であれば80Å以上の粒子は全く
透過していないと考えてよい。
このような排除率を有するポリスルホン中空繊
維膜は分子量16万の球状蛋白質である牛血清γ−
グロブリンを実質的に阻止するようにもできる
し、さらにいかなるバクテリアやウイルスも完全
に阻止することはもちろん、細菌の分泌物で発熱
性の原因物質（パイロジエン）といわれているリ
ポポリサツカライドも完全に阻止することもでき
る。また電気的に中性の線状ポリマーで分子量が
120万の単分散標準ポリエチレンオキサイド（東
洋曹達株式会社製の「SE−150」）を阻止するよ
うにすることもできる。
次に本発明のポリスルホン中空繊維膜は圧密化
指数0.2以下であることも大きな特徴のひとつで
ある。ここで圧密化指数αとは次式で表わされ
る。
α＝１−KA4／KA1
KA1：100℃の熱水を外圧方式により過圧１
Kg／cm2で過した時の透水速度（／m2・
hr・Kg／cm2）
KA4：100℃の熱水を外圧方式により過圧４
Kg／cm2で過した時の透水速度（／m2・
hr・Kg／cm2）
この圧密化指数αが0.2以下、すなわち０〜0.2
を示すということは耐圧性、とくに高温時の耐圧
性が優れ、さらに過速度の経時低下の少ないこ
とを意味している。したがつて、αが0.2より大
きいものは好ましくない。
通常過は100℃で実施されることは稀で、10
〜60℃が通常の過温度であり、従つて100℃で
のαの値は工業的意義が乏しいとも考えられる。
しかし10〜60℃では短期的には圧密化しないもの
で長期的に使用すると、徐々に圧密化し過速度
が低下するものと、ほとんど圧密化せず過速度
が低下しないものもある。この違いを短時間に判
断する評価パラメーターとして100℃の熱水での
αの値が有用である。
以上のとおり本発明のポリスルホン中空繊維膜
は分画性（膜を透過する最大のサイズ）がいわゆ
る限外過オーダーと小さいにもかかわらず、透
水速度が大きく、かつ耐圧性、耐熱性も大きいと
いう優れた性能を有する。
次に本発明のポリスルホン中空繊維膜の製法に
ついて述べる。
従来より膜の透過性能を改善するために製膜原
液に変性剤を添加する方法が行なわれており、ポ
リマーと溶媒の種類により各種のものが報告され
ている。例えば、原液の溶媒和効果を増大させ
る、いわゆる膨潤剤として、ZnCl2の無機塩、ア
ルコール等の有機物がある。その他膨潤剤として
ポリエチレングリコール（PEG）がある。
変性剤としてのPEGは、水溶性であり製膜後
容易に抽出除去できるため取扱い性が良い、各種
の分子量を有したものがあるため種類を選択する
ことにより透過性能をコントロールしうる、ポリ
マーの溶媒に対する溶解度が大であるため高分子
量物であるにもかかわらず比較的添加量を大にす
ることができる、高分子量物であるため原液粘度
を増大させる性質を有している等の多くの利点を
有している。
このうち、原液への添加量を増加することは透
過性能、特に透水性を増大することができ有効で
ある。また原液の粘度に関して、通常透水性はポ
リマー濃度が小の程大となり有利であるが、ポリ
マー濃度が小であると原液粘度が小となり、粘度
が低すぎる場合製膜安定性が劣る場合がある。た
とえば中空繊維の場合、ある粘度以上でなければ
紡糸が困難となること等から、PEG添加による
増粘効果は有利である。
上記のように、PEGは添加剤として優れてお
り、PEGを用いたポリスルホン膜の製法につい
ても特開昭50−89475や54−26283がすでに知られ
ている。
ところで一般に変性剤であるPEGを添加して
製膜する技術において、第１に重要な点は製膜性
にすぐれた原液を調製することである。
透水性等の膜性能を向上させるためには添加量
を多くすることが望ましい。しかしながらPEG
はポリスルホンに対しては非溶媒として働くた
め、原液に必要なポリスルホンの濃度を確保した
上で添加できるPEGの量には自ら限界が生じる
ことになる。PEGの添加量は上述のポリスルホ
ンの濃度の他、PEGの分子量等の各種の因子に
依存し、ポリスルホン濃度やPEGの分子量が大
きいほど、添加量は少なくなる。
従来の技術においては、上述のような条件の範
囲内で、良好な原液として均一で実質的に透明な
溶液を調製して用いていた。
例えば特開昭50−89475の実施例６では、ポリ
スルホン12％の原液においてPEGはポリスルホ
ンと等量、即ち100重量％添加されている。又特
開昭54−26283ではポリスルホン濃度30％までに
おいて、PEGをポリスルホンに対し300重量％ま
での量を添加することが示されている。
しかしながら、該技術においても、原液はポリ
スルホンが析出しない程度で使用されなければな
らないと明示されており、均一で透明な溶液を原
液とする従来技術の範囲内にあることが明らかで
ある。従つてポリスルホンの濃度が10％程度の低
濃度では100％以上のPEG添加も可能であるが、
ポリスルホンの濃度が高くなれば、PEGの添加
量はそれ以下に低下せざるを得ないのである。
本発明者らは、従来技術の限界を打破し、より
多くのPEGを添加し、一層の膜性能の改善を目
的として、種々検討した結果、今まで全く考えら
れなかつた現象を見い出し、該事実に基づいた新
規なポリスルホン中空繊維膜の製法を発明した。
すなわち本発明のポリスルホン中空繊維膜はポ
リスルホン、PEGおよびこれらの共通溶媒とか
らなる紡糸原液を環状ノズルから押出して中空繊
維を製造するに際し、〔１〕ポリスルホンとPEG
をこれらの共通溶媒に溶解するに際し、該溶液を
100℃にした場合に相分離現象を示す量のPEGを
添加して、調製した紡糸原液を用いること、およ
び〔２〕乾湿式紡糸することによつて製造するこ
とができる。
本発明者らは、まず100℃のポリスルホン溶液
にPEGを加えてゆくと、均一溶液の領域から、
PEGおよび／またはポリスルホンの相分離が生
ずることを認めた。従来技術では、相分離領域の
スラリーは、製膜原液としては全く使用できない
ものとされていた。本発明者らも、ミクロ相分離
したスラリーは、そのまゝでは原液に使えないこ
とを確認した。
しかしながら驚くべきことに、該相分離領域の
スラリーを、冷却等により調整すると、均一でか
つ透明な溶液に変化し、この溶液は製膜原液とし
て極めて良好に使用できることを見い出した。溶
解度を向上させるためには、通常は温度を上げる
べきであるが、本現象では、逆に冷却することに
より均一溶液となるのであり、かゝる事実は、全
く予想できないことであつた。本発明により、従
来の添加量の限界を超えた量のPEGを含む原液
を製膜することが可能となり、その結果得られる
膜の性能も格段に改善されたものとなつた。
本発明において相分離現象を示す量とはPEG
を100℃のポリスルホンと溶媒の混合液に添加し
ていつた時、ポリスルホンおよび／またはPEG
が相分離をおこし不均一白濁スラリーとなるが、
該スラリーを後述する冷却攪拌により均一または
ほぼ均一溶液としうる程度の量をいう。冷却攪拌
しても均一溶液としえない程度の量は本発明にお
いては除外される。このような均一溶液としえな
い程度のPEGを添加して得た紡糸原液からは安
定に製膜することができず、さらに得られた膜は
たとえばマクロボイドを含有する不均一なものと
なり、本発明の目的とする膜とはならない。
PEGの最大添加量はポリスルホン濃度、PEG
分子量、溶媒の種類等に依存し、一般にはポリス
ルホン濃度大、PEG分子量大なる程最大添加量
は小となる。
この相分離現象を示すPEGの添加量とは具体
的にはポリスルホンに対し80〜250重量％、好ま
しくは120〜200重量％である。またPEGは分子
量400〜20000、好ましくは600〜2000のものが用
いられる。400未満のものは添加量の増大に見あ
うほどの膜の透過性能の向上が得難く、一方
20000を越えるものは添加量を大とすることがで
きず、十分な透過性能を与えず好ましくない。
ポリスルホン、PEGおよびこれらの共通溶媒
の混合物をポリスルホンとPEGの溶媒に対する
溶解速度を考慮して、通常80℃〜130℃さらには
100℃〜130℃で加熱攪拌すると白濁した相分離ス
ラリーとなる。
そしてこのようにして得られたポリスルホン、
PEGおよびこれらの共通溶媒の相分離スラリー
を調製して紡糸原液とする。ここで調製とは冷却
攪拌等により相分離スラリーを均一透明な、また
はほぼ均一透明な溶液とすることである。またこ
こで冷却温度は主にPEGの添加量および種類等
に依存するが、通常60〜０℃、好ましくは10〜40
℃である。
このように本発明においては相分離現象を示す
量のPEGをポリスルホンおよび溶媒の混合液に
添加し、80〜130℃で加熱攪拌し、白濁相分離ス
ラリーとし、次いで０〜60℃に冷却攪拌して紡糸
原液とするのがもつとも短時間で紡糸原液を調製
できる効率のよい方法であるが、その他の方法、
たとえば100℃において相分離現象を示す量の多
量のPEGをポリスルホンおよび溶媒の混合液に
添加し、低温下で、たとえば０〜60℃下で長時間
攪拌することによつても均一、またはほぼ均一な
紡糸原液を得ることもできる。
本発明のポリスルホン中空繊維膜の製法におい
て、紡糸原液中のポリスルホン濃度は12〜30重量
％、好ましくは15〜22重量％である。12重量％未
満では得られた膜の強度が十分でなく、一方30重
量％を越えるとポリマー濃度が大のため、および
PEGの添加量を大とすることができないため、
十分な透過性能を有する膜が得られず好ましくな
い。
ポリスルホンとPEGの共通溶媒は、ポリスル
ホンおよびPEGを溶解し、かつポリスルホンに
対し凝固能を有する凝固液に対し相溶性のあるも
の、たとえば、Ｎ，N′−ジメチルホルムアミド、
ジメチルスルホキシド、ジメチルアセトアミド、
Ｎ−メチルピロリドン等の極性有機溶媒があげら
れる。このうちＮ，N′−ジメチルホルムアミド
（DMF）が最良である。
このようにして得られた紡糸原液は冷却された
まま、あるいは相分離しない程度に加熱して、環
状ノズルを通して乾湿式紡糸しなければならな
い。通常用いられている湿式紡糸法では外表面に
所望の孔が形成されず、本発明の中空繊維を得る
ことができない。ここにいう乾湿式紡糸とは紡糸
原液を一旦気体（大ていの場合空気）に押し出
し、次いで凝固液中に導入する方式、すなわち、
ノズルが凝固液に浸漬されていない方式をいう。
ノズル吐出面と凝固液表面の距離すなわち気中走
行距離をドライゾーン長と定義すると、ドライゾ
ーン長は0.1〜200cmがよい。0.1cmより短いとわ
ずかな凝固液の波立ちでもノズルが凝固液に浸漬
されてしまうので実質的に乾湿式紡糸することは
できない。200cmを越えると糸揺れが大きく正常
な紡糸ができない。より好適なドライゾーン長は
0.5〜50cmで、１〜30cmが紡糸性の膜性能のバラ
ンス上最もよい。従来中空繊維膜の細径化と紡糸
速度向上の目的で乾湿式紡糸をしたり、ドライゾ
ーン中で溶媒を蒸発させて表面にスキン層を得る
目的で乾湿式紡糸する場合が多いが、本発明の場
合には、表面にスキン層を作らせるのではなく、
むしろ逆に微孔を形成させるものであり、ドライ
ゾーン中に存在する微量の水分により緩徐な凝固
を生起せしめる。従つて従来の乾湿式紡糸の目的
および作用効果とは明らかに異なつている。本発
明の乾湿式紡糸の結果はドライゾーン長が0.1cm
と非常に短くてもドライゾーン長０cmの湿式紡糸
とは明確な違いを示す点でも特徴的である。この
ドライゾーン長やドライゾーンの雰囲気により外
表面の孔径を制御しうる。凝固液はポリスルホン
とPEGの共通溶媒に混和性があり、かつポリス
ルホンの非溶媒であれば特に限定はない。一般に
は水あるいは溶媒（好ましくはジメチルホルムア
ミド）と水の混合液が使用される。さらに界面活
性剤などを添加すると好都合な場合がある。環状
ノズルのニードルに流す内部凝固流体は凝固性液
体、非相溶性液体、気体（空気、窒素）など特に
限定はないが、水などの凝固性液体がよい。その
中でも中空繊維膜内表面にスリツト状微細隙を形
成させるためには溶媒と水の混合液、溶媒／水の
重量比が０／100〜85／15の凝固性液体が優れて
いる。溶媒／水の比率が０／100〜80／20であれ
ば紡糸性と膜性能のバランスの上で最適である。
凝固後、溶媒およびPEGを除去するために洗
浄が行なわれる。
また必要に応じPEGの除去と耐圧性の向上の
ために水を主成分とした浴中で湿熱処理を行なう
ことができる。通常湿潤膜を乾燥すると透水性が
低下するが、湿熱処理により乾燥後も透水性を保
持できる場合があり有効である。
次に本発明のポリスルホン中空繊維膜を用いた
使用方法について述べる。
本発明の中空繊維膜はとくに外圧全過方式に
おいて優れた過性能を示す。たとえば水道水を
本発明の中空繊維膜により注意深く外圧全過す
ると、いかなる微生物も除去することができ、か
つ微生物の分泌物といわれるパイロジエン物質を
も完全に除去することができ、パイロジエンフリ
ー水が容易に得られる。しかも透過速度は従来の
パイロジエンをカツトしうる膜に比べると非常に
高い傾向がある。このように外圧全過方式とい
う簡単なシステムでパイロジエン除去と高透過速
度が同時に得られるのは、本発明の中空繊維膜は
外表面に比較的大きい微孔を有し、内部構造が均
一なスポンジ状で、内表面に緻密なスリツト状構
造のスキン層を有するため、外表面にてサブミク
ロンオーダー以上の粒子が捕捉され、膜内部又は
内表面にてサブミクロン以下の溶解ポリマーを含
む物質が捕捉される。すなわち外表面及び内部構
造プレフイルターの役割を果すため、従来の中空
繊維膜にて得られる透過速度よりはるかに高い値
が得られる。また本発明の中空繊維膜は内表面に
緻密なスリツト状構造のスキン層を有しており、
通常の限外過用中空繊維膜と同じように内圧循
環方式の過にも有効である。たとえばポリマー
を濃縮回収したり、排水中のCOD成分を除去す
ることができるし、また医療用分野とくに体液た
とえば血液、血漿、腹水などの過あるいは濃縮
膜にも使用しうる。
以下実施例により本発明をさらに説明する。
実施例 １
ポリスルホン（UCC製 Udel Ｐ−1700）20重
量部、分子量600のポリエチレングリコール（三
洋化成製PEG＃600）36重量部（PEG＃600の添
加量180重量％／ポリスルホン）およびDMF44重
量部を120℃で加熱攪拌して白濁相分離したスラ
リー状原液を得た。該原液を25℃に冷却しながら
攪拌することにより均一透明な原液を得た。
25℃にて一夜静置脱泡した紡糸原液を６ホール
の環状ノズルを用い、内部凝固液としてDMF／
水が重量比で80／20の混合液を注入しながら、乾
湿式紡糸を行つた。この際紡糸時の原液温度は25
℃、ドライゾーン長は10cm、ドライゾーンの雰囲
気は25℃、相対湿度60％であり、外部凝固液は20
℃の水とした。次いで水洗し、1.2ｍの平枠に捲
いた後100℃の熱水中に２時間浸漬してポリエチ
レングリコールを除去するとともに熱処理を行つ
た。
得られた中空繊維膜は外径750μ、内径500μで
あり、表面及び断面を走査型電子顕微鏡（SEM）
で観察した結果、外表面には平均0.3μの微孔が35
％の開孔率で存在し、内表面は平均巾0.04μのス
リツト状微細隙構造であり、内外表面および内部
には10μ以上の巨大空洞は全く存在せず、内部は
ほぼ均一網目状のスポンジ構造をとつていること
がわかつた。また25℃の純水の透水速度KAは
1000／m2・hr・Kg／cm2と優れていた。また0.1
％の牛血清γグロブリンの排除率は99％以上であ
り、分子量120万の標準ポリエチレンオキサイド
（東洋ソーダ製SE−150）の0.1％水溶液の排除率
も99％以上であつた。また100℃での１Kg／cm2と
４Kg／cm2での外圧透水性測定による圧密化指数α
は0.15と小さく良好であつた。
実施例 ２
内部凝固液として水単独を用いる以外は実施例
１と同じ条件で中空繊維膜を得た。
得られた中空繊維膜の表面および断面をSEM
で観察した結果、外表面には平均0.18μの微孔が
25％の開孔率でほぼ網目状に存在し、内表面は平
均巾100Åのスリツト状微細隙構造であり、内外
表面および内部には10μ以上のボイドが存在せ
ず、スポンジ構造であることを認めた。またKA
は730／m2・hr・Kg／cm2と優れていた。また牛
血清γグロブリンや分子量120万の標準ポリエチ
レンオキサイドの排除率は98％以上であつた。さ
らにパイロジエンのモデル物質であるエンドトキ
シンＥ Coli 0127 B8（Difco Labo製）を3.5
mg／溶解した水を外圧全過方式で過した
後、その水は初流はもちろん100／m2過後
もリムラステストはマイナスであり、本中空繊維
膜はパイロジエンを完全に阻止する膜であつた。
また圧密化指数αは0.10と小さく、耐圧、耐熱性
の優れたものであつた。
比較例 １
内部凝固液としてDMF／水が重量比で90／10
の混合液を用いる以外は実施例１と同じ条件で中
空繊維膜を得た。但し、ドライゾーン長は10cmで
は紡糸調子が不安定であつたので１cmとした。
得られた中空繊維膜の表面および断面をSEM
で観察した結果、外表面には平均0.3μの孔が30％
の開孔率で存在し、実施例１、２とあまり変わら
なかつたが、内表面は2μオーダーの凹凸あるい
は微孔が存在し、スリツト状微細隙構造ではなか
つた。内外表面および内部は10μ以上のボイドの
ないスポンジ構造であつた。SEMによる写真を
第１図に示す。またKAは1350／m2・hr・Kg／
cm2と優れていたが、牛血清γ−グロブリンの阻止
率は５％ときわめて低いものであつた。またエン
ドトキシンＥ Coli 0127 B8の水溶液を過し
た水は、リムラステストでダブルプラスであ
り、パイロジエンを阻止しない膜であつた。
比較例 ２
ドライゾーン長を０cm（すなわち湿式紡糸）と
する以外は全て実施例２と同じ条件で中空繊維膜
を得た。
得られた中空繊維膜の外表面をSEMで観察し
た結果、0.1μ以上の微孔は認められなかつた。
SEMによる写真を第２図に示す。この中空繊維
膜のKAは150／m2・hr・Kg／cm2と低いものであ
つた。
実施例 ３
ポリスルホン（UCC製 Udel Ｐ−1700）4.0
Kg、分子量600のポリエチレングリコール（三洋
化成製PEG＃600）6.8Kg（PEG＃600の添加量170
重量％／ポリスルホン）、およびDMF9.2Kgを120
℃で450rpmの回転速度で６時間加熱攪拌し、白
濁相分離したスラリー状原液を得た。該原液を攪
拌しながら20℃に冷却すると均一透明原液を得
た。この原液を再び徐々に昇温すると35℃付近の
狭い温度範囲で鋭く白濁した。20℃に冷却すると
再び完全に透明となり、可逆性があることを認め
た。
この原液を20℃で一夜静置し、透明原液を18ホ
ールの環状ノズルを用い、乾湿式紡糸を行つた。
この際紡糸タンクからノズルに至る原液配管のジ
ヤケツト温度を34℃として紡糸原液がノズルより
吐出されるまでに原液が白濁相分離する直前の状
態となるようコントロールした。またドライゾー
ン長は10cmとし、ドライゾーンの雰囲気は25℃、
相対湿度50％となるよう空気を5Nl／min送風し
た。また外部凝固液および内部凝固液ともに20℃
の水とした。次いで水洗と熱水洗を行つた後、枠
に捲き取り、枠巻状でさらに95℃の熱水中に１時
間浸漬した。
得られた中空繊維膜は外径700μ、内径450μで
あり、表面及び断面をSEMで観察した結果、外
表面には平均0.2μの孔が38％の開孔率で存在し、
内表面は平均巾100Åのスリツト状微細隙構造で
あり、内外表面および内部は10μ以上のボイドは
全く存在しないスポンジ構造をとつていることが
わかつた。SEMによる写真を第３〜第６図に示
す。またKAは770／m2・hr・Kg／cm2と優れてい
た。また牛血清γ−グロブリンおよび分子量120
万の標準ポリエチレンオキサイドの排除率は99％
以上であつた。また100℃熱水中での圧密化指数
αは0.12と優れていた。
また得られた中空繊維膜をウレタンにより遠心
接着して有効長26cm、膜面積0.8m2の片端開孔タ
イプの小型モジユール（全長33cm、筒径４cmφ）
を作製した。このモジユール及び水側塩ビホー
スを３％過酸化水素水に一夜浸透し、殺菌とパイ
ロジエン分解を行つた後、倉敷市の水道水の蛇口
に接続し、外圧全過方式で水道水を何ら前処理
することなく、直接過した。過圧は１Kg／cm2
で52日間連続過した。過開始１時間、１日、
３日、７日、14日、21日、32日、49日後に各々
水をとり、リムラステストを行つた所で全てマイ
ナスであつた。なお参考のために水道水そのまま
をリムラステストを行つた所、全てダブルプラス
であつた。従つて本発明中空繊維膜により容易に
パイロジエンフリー水が得られることがわかつ
た。またこの際の水の過速度は平均2.8／
min・モジユールat25℃であつた。きわめて小型
なモジユールで、前処理もなく、ポンプその他の
システムも一切不要の簡単な方法で、しかもかな
りの量のパイロジエンフリー水を連続的に得るこ
とが出来た。水道水を微多孔ポリビニルアルコー
ル系中空繊維膜（クラレ製SF−301膜）で過
後、本発明の中空繊維膜モジユールにより過す
ると本発明中空繊維膜モジユールの過速度はさ
らに大きくなり、もちろんパイロジエンフリーで
あつた。
実施例 ４
ポリスルホン（UCC製 Udel Ｐ−3500）20重
量部、分子量1000のポリエチレングリコール（三
洋化成製PEG＃1000）36重量部（PEG＃1000の
添加量180重量％／ポリスルホン）及びDMF44重
量部を25℃で24時間攪拌して均一透明原液を得
た。脱泡後実施例２と同様にして、中空繊維膜を
得た。
得られた中空繊維膜の表面および断面をSEM
で観察した結果、外表面には平均0.3μの孔が35％
の開孔率で存在し、内表面は平均巾200Åのスリ
ツト状微細隙構造であり、断面は10μ以上のボイ
ドが全く存在せず、スポンジ構造となつているこ
とがわかつた。またKAは880／m2・hr・Kg／
cm2、牛血清γ−グロブリンの阻止率は97％で良好
であつた。
実施例 ５
ドライゾーン長10cmとしドライゾーンの雰囲気
は40℃、相対湿度95％となる様調湿空気を10／
分送風した以外は実施例３と同じ条件で外型
780μ、内径450μの中空繊維膜を得た。得られた
中空繊維膜の表面及び断面をSEMで観察した結
果、外表面には平均0.35μの微孔が48％の開口率
でほぼ網目状に存在し、内表面は平均巾100Åの
スリツト状、微細隙構造であり、内外表面及び膜
壁内部は10μ以上のボイドは全く存在しないスポ
ンジ構造をとつていることがわかつた。この中空
糸膜のKAは740／m2・hr・Kg／cm2と優れてい
た。また、牛血清γ−グロブリン（IgG）及び分
子量120万の標準ポリエチレンオキサイドの排除
率は99％以上であつた。また、エンドトキシンＥ
Coli 0127 B8（Difco Labo製）を3.5mg／溶
解した水を外圧全過方式で過した水のパイ
ロジエンをリムラステストでチエツクした結果
0.02nｇ／ml以下であり、パイロジエンは完全に
阻止されていることを認めた。また、圧密化指数
αは0.11と小さく、耐圧、耐熱性の優れたもので
あつた。[Formula] Those in which Z is O, such as "Udel" manufactured by Union Carbide Co., are industrially easiest to use. Furthermore, the polysulfone hollow fiber membrane of the present invention has the above-mentioned structure and has a water permeability of 700 to 700.
6000/ m2・hr・Kg/ cm2 . The inner diameter of the polysulfone hollow fiber membrane of the present invention is 250
~1500μ, outer diameter is 350~3000μ, preferably inner diameter is
300-1000μ, outer diameter 400-2000μ, more preferably inner diameter 350-700μ, outer diameter 500-1200μ, the water permeation rate per membrane area and pressure resistance are excellent,
Furthermore, the balance of other membrane performances is also improved. The water permeation rate in the present invention refers to the water permeation rate K A per membrane area of hollow fibers, and is measured by the following method.
Method for measuring water permeation rate K A ; (i) Hollow fiber membrane bundle: A new hollow fiber membrane bundle with a hollow fiber length of 20 cm and a membrane area of 200 cm 2 based on the outer diameter. (ii) Passage: Measure the water permeation rate (/m 2・hr・Kg/cm 2 ) K A when pure water at a temperature of 25°C is passed through at a pressure of 1Kg/cm 2 using the external pressure full-passage method. Water permeation rate of the polysulfone hollow fiber membrane of the present invention
K A is 700 to 6000/ m2・hr・Kg/ cm2 . Note that hollow fiber membranes with a K A of 6000/m 2 ·hr · Kg/cm 2 or more are not practical because the current technology only provides a small rejection rate R, which will be described later. Furthermore, the polysulfone hollow fiber membrane of the present invention is substantially impermeable to substances with a diameter of 80 Å or more. Here, "substantially not permeating substances with a particle size of 80 Å or more" means that the exclusion rate R of colloidal silica having an average particle size of 80 Å is measured under the following conditions, and R is 95% or more. Method for measuring rejection rate (i) Hollow fiber membrane bundle: A hollow fiber membrane bundle with a hollow fiber length of 20 cm and a membrane area of 200 cm 2 based on the outer diameter was prepared and used. (ii) Measurement liquid: Colloidal silica 1 with an average particle size of 80 Å
% liquid {Dilute Snotex-S (colloidal silica with the smallest particle size) manufactured by Nissan Chemical Industries, Ltd. with distilled water}. (iii) Overcondition: External pressure total overflow method, overpressure 0.5Kg/
cm2 , temperature 25℃. Note that the hollow fiber membrane bundle is thoroughly drained of water before use, and after the inside of the hollow fiber membrane wall is also replaced with colloidal silica liquid, pressure is applied and filtration is started. (iv) Sampling: Sampling is performed 5 times every 10 c.c. from the measurement stock solution just before pressurization and the initial flow of the liquid after pressurization. The six samples obtained were heated at 100℃ for 16 hours.
Dry and measure solid content concentration. (v) Calculation of rejection rate R; solid content concentration C D of the measurement stock solution
and the highest solids concentration C F max among the five liquids.
From the following equation, R is determined. R = (1-C F max / C D ) x 100 If a colloidal liquid is used as in this measurement method, it may contain dissolved substances other than particles.
Since R is determined by the gravimetric method, even if R is 97%, it is 80%.
This does not mean that 3% of particles with a diameter of Å are transmitted, and if R is 95% or more, it can be considered that particles with a diameter of 80 Å or more are not transmitted at all. A polysulfone hollow fiber membrane with such an exclusion rate is capable of absorbing bovine serum γ-, a globular protein with a molecular weight of 160,000.
It can virtually block globulin, and it can also completely block all bacteria and viruses, as well as lipopolysaccharide, which is a bacterial secretion and is said to be a pyrogen. It can also be prevented. It is also an electrically neutral linear polymer with a molecular weight of
1.2 million monodisperse standard polyethylene oxide ("SE-150" manufactured by Toyo Soda Co., Ltd.) can also be blocked. Another major feature of the polysulfone hollow fiber membrane of the present invention is that it has a compaction index of 0.2 or less. Here, the consolidation index α is expressed by the following equation. α=1−K A4 /K A1 K A1 : Overpressure 1 of hot water at 100℃ using external pressure method.
Water permeability rate in Kg/ cm2 (/ m2・
hr・Kg/cm 2 ) K A4 : 100℃ hot water is heated to overpressure 4 using external pressure method.
Water permeability rate in Kg/ cm2 (/ m2・
hr・Kg/cm 2 ) This consolidation index α is 0.2 or less, that is, 0 to 0.2
This means that the pressure resistance, especially at high temperatures, is excellent, and the overspeed decreases little over time. Therefore, α larger than 0.2 is not preferable. Normal filtration is rarely carried out at 100℃,
~60°C is a normal overtemperature, and therefore the value of α at 100°C is considered to have little industrial significance.
However, at temperatures between 10 and 60°C, some do not become compacted in the short term, but with long-term use, they gradually become compacted and the overspeed decreases, while others hardly become compacted and the overspeed does not decrease. The α value for hot water at 100°C is useful as an evaluation parameter to quickly determine this difference. As described above, although the polysulfone hollow fiber membrane of the present invention has a small fractionation property (maximum size that permeates through the membrane) of the so-called ultrafiltration order, it has a high water permeation rate and high pressure resistance and heat resistance. Has excellent performance. Next, a method for manufacturing the polysulfone hollow fiber membrane of the present invention will be described. In order to improve the permeation performance of membranes, a method of adding a modifier to the membrane-forming stock solution has been conventionally used, and various methods have been reported depending on the type of polymer and solvent. For example, so-called swelling agents that increase the solvation effect of the stock solution include inorganic salts of ZnCl 2 and organic substances such as alcohol. Other swelling agents include polyethylene glycol (PEG). PEG as a modifier is water-soluble and can be easily extracted and removed after membrane formation, making it easy to handle.Since it has various molecular weights, the permeation performance can be controlled by selecting the type. It has a high solubility in solvents, so it can be added in a relatively large amount even though it is a high molecular weight product, and because it is a high molecular weight product, it has the property of increasing the viscosity of the stock solution. It has advantages. Among these, increasing the amount added to the stock solution is effective because it can increase permeation performance, particularly water permeability. Regarding the viscosity of the stock solution, normally the lower the polymer concentration, the higher the water permeability, which is advantageous, but if the polymer concentration is low, the viscosity of the stock solution will be small, and if the viscosity is too low, the stability of film formation may be poor. . For example, in the case of hollow fibers, it is difficult to spin them unless the viscosity exceeds a certain level, so the thickening effect of adding PEG is advantageous. As mentioned above, PEG is excellent as an additive, and methods for producing polysulfone membranes using PEG are already known in JP-A-50-89475 and JP-A-54-26283. By the way, in the technique of generally adding PEG, which is a modifier, to form a film, the first important point is to prepare a stock solution with excellent film-forming properties. In order to improve membrane performance such as water permeability, it is desirable to increase the amount added. However, PEG
Since PEG acts as a non-solvent for polysulfone, there is a limit to the amount of PEG that can be added while ensuring the necessary concentration of polysulfone in the stock solution. The amount of PEG added depends on various factors such as the molecular weight of PEG in addition to the above-mentioned concentration of polysulfone, and the larger the concentration of polysulfone and the molecular weight of PEG, the smaller the amount added. In the prior art, a homogeneous and substantially transparent solution was prepared and used as a good stock solution within the above-mentioned conditions. For example, in Example 6 of JP-A-50-89475, in a stock solution of 12% polysulfone, PEG is added in an amount equal to that of polysulfone, that is, 100% by weight. Furthermore, JP-A-54-26283 discloses that PEG can be added in an amount of up to 300% by weight based on polysulfone when the polysulfone concentration is up to 30%. However, even in this technique, it is clearly stated that the stock solution must be used to an extent that polysulfone does not precipitate, and it is clear that the stock solution is within the scope of the prior art, which uses a uniform and transparent solution as the stock solution. Therefore, it is possible to add more than 100% PEG when the polysulfone concentration is as low as 10%.
If the concentration of polysulfone increases, the amount of PEG added must be lowered. As a result of various studies aimed at breaking through the limitations of conventional technology and further improving membrane performance by adding more PEG, the present inventors discovered a phenomenon that had never been thought of until now. We have invented a new method for producing polysulfone hollow fiber membranes based on That is, the polysulfone hollow fiber membrane of the present invention is produced by extruding a spinning dope consisting of polysulfone, PEG, and a common solvent thereof through an annular nozzle to produce hollow fibers.
When dissolving in these common solvents, the solution is
It can be produced by using a spinning stock solution prepared by adding PEG in an amount that causes a phase separation phenomenon when heated to 100°C, and [2] by dry-wet spinning. The present inventors first discovered that when PEG was added to a polysulfone solution at 100°C, from a homogeneous solution region,
It was observed that phase separation of PEG and/or polysulfone occurred. In the prior art, it was assumed that the slurry in the phase separation region could not be used as a membrane forming stock solution at all. The present inventors also confirmed that the microphase-separated slurry cannot be used as a stock solution as it is. However, it was surprisingly found that when the slurry in the phase separation region was adjusted by cooling or the like, it turned into a homogeneous and transparent solution, and this solution could be used extremely well as a membrane-forming stock solution. Normally, to improve solubility, the temperature should be raised, but in this phenomenon, on the contrary, a homogeneous solution was formed by cooling, which was completely unexpected. According to the present invention, it has become possible to form a film from a stock solution containing PEG in an amount exceeding the conventional limit of addition, and the performance of the resulting film has also been significantly improved. In the present invention, the amount exhibiting a phase separation phenomenon is PEG
When added to a mixture of polysulfone and solvent at 100℃, polysulfone and/or PEG
causes phase separation and becomes a non-uniform cloudy slurry,
This refers to the amount that allows the slurry to be made into a homogeneous or nearly homogeneous solution by cooling and stirring as described below. The present invention excludes such an amount that a homogeneous solution cannot be obtained even by cooling and stirring. It is not possible to stably form a film from a spinning stock solution obtained by adding PEG to such an extent that it cannot be made into a homogeneous solution, and the resulting film is non-uniform, containing, for example, macrovoids. It is not the desired film. The maximum amount of PEG added is the polysulfone concentration, PEG
It depends on the molecular weight, type of solvent, etc., and in general, the higher the polysulfone concentration and the higher the PEG molecular weight, the smaller the maximum addition amount. Specifically, the amount of PEG that exhibits this phase separation phenomenon is 80 to 250% by weight, preferably 120 to 200% by weight based on the polysulfone. Further, PEG having a molecular weight of 400 to 20,000, preferably 600 to 2,000 is used. If it is less than 400, it is difficult to improve the permeation performance of the membrane commensurate with the increase in the amount added.
If it exceeds 20,000, it is not possible to increase the amount added, and it does not provide sufficient permeation performance, which is not preferable. Polysulfone, PEG and a mixture of these common solvents are usually heated between 80℃ and 130℃, considering the dissolution rate of polysulfone and PEG in the solvent.
When heated and stirred at 100°C to 130°C, a cloudy phase-separated slurry is obtained. And the polysulfone obtained in this way,
A phase-separated slurry of PEG and their common solvents is prepared as a spinning dope. Preparation here means making the phase-separated slurry into a uniformly transparent or almost uniformly transparent solution by cooling, stirring, or the like. The cooling temperature here mainly depends on the amount and type of PEG added, but is usually 60 to 0°C, preferably 10 to 40°C.
It is ℃. In this way, in the present invention, PEG in an amount that causes a phase separation phenomenon is added to a mixture of polysulfone and a solvent, heated and stirred at 80 to 130°C to form a cloudy phase-separated slurry, and then cooled and stirred to 0 to 60°C. It is an efficient method to prepare a spinning stock solution in a short time, but there are other methods.
For example, by adding a large amount of PEG that exhibits a phase separation phenomenon at 100°C to a mixed solution of polysulfone and a solvent, and stirring the mixture for a long time at a low temperature, e.g. 0 to 60°C, the mixture becomes uniform or almost uniform. It is also possible to obtain a spinning dope. In the method for producing polysulfone hollow fiber membranes of the present invention, the concentration of polysulfone in the spinning dope is 12 to 30% by weight, preferably 15 to 22% by weight. If it is less than 12% by weight, the resulting film will not have sufficient strength, while if it exceeds 30% by weight, the polymer concentration will be high, and
Since it is not possible to increase the amount of PEG added,
This is not preferable because a membrane with sufficient permeability cannot be obtained. The common solvent for polysulfone and PEG is one that dissolves polysulfone and PEG and is compatible with a coagulating liquid that has coagulation ability for polysulfone, such as N,N'-dimethylformamide,
dimethyl sulfoxide, dimethyl acetamide,
Examples include polar organic solvents such as N-methylpyrrolidone. Among these, N,N'-dimethylformamide (DMF) is the best. The spinning dope thus obtained must be cooled or heated to such an extent that phase separation does not occur, and must be subjected to dry-wet spinning through an annular nozzle. The commonly used wet spinning method does not form desired pores on the outer surface, making it impossible to obtain the hollow fibers of the present invention. The dry-wet spinning referred to here is a method in which the spinning stock solution is once extruded into gas (air in most cases) and then introduced into the coagulation liquid.
A method in which the nozzle is not immersed in the coagulating liquid.
If the distance between the nozzle discharge surface and the surface of the coagulating liquid, that is, the aerial travel distance, is defined as the dry zone length, the dry zone length is preferably 0.1 to 200 cm. If the length is shorter than 0.1 cm, the nozzle will be immersed in the coagulation liquid even if the coagulation liquid is slightly rippled, so wet-dry spinning is practically impossible. If the length exceeds 200 cm, the yarn will swing too much and normal spinning will not be possible. The more suitable dry zone length is
0.5 to 50 cm, and 1 to 30 cm is the best balance for spinnability and membrane performance. Conventionally, wet-dry spinning is often used to reduce the diameter of hollow fiber membranes and increase spinning speed, or to evaporate solvents in a dry zone to form a skin layer on the surface, but the present invention In this case, instead of creating a skin layer on the surface,
On the contrary, it forms micropores and causes slow coagulation due to the small amount of moisture present in the dry zone. Therefore, the purpose and effects are clearly different from conventional dry-wet spinning. The result of the dry-wet spinning of the present invention is that the dry zone length is 0.1 cm.
It is also unique in that it shows a clear difference from wet spinning, which has a dry zone length of 0 cm, even though it is very short. The pore diameter on the outer surface can be controlled by the dry zone length and the atmosphere of the dry zone. The coagulation liquid is not particularly limited as long as it is miscible with the common solvent of polysulfone and PEG and is a non-solvent of polysulfone. Generally, water or a mixture of a solvent (preferably dimethylformamide) and water is used. Additionally, it may be advantageous to add surfactants and the like. The internal coagulating fluid to be flowed into the needle of the annular nozzle is not particularly limited to a coagulable liquid, an incompatible liquid, a gas (air, nitrogen), etc., but a coagulable liquid such as water is preferable. Among these, in order to form slit-like micropores on the inner surface of the hollow fiber membrane, a mixed solution of a solvent and water, and a coagulable liquid having a weight ratio of solvent/water of 0/100 to 85/15 are excellent. A solvent/water ratio of 0/100 to 80/20 is optimal in terms of balance between spinnability and membrane performance. After coagulation, washing is performed to remove solvent and PEG. Further, if necessary, moist heat treatment can be performed in a bath mainly containing water in order to remove PEG and improve pressure resistance. Normally, when a wet membrane is dried, its water permeability decreases, but moist heat treatment is effective because it can maintain its water permeability even after drying. Next, a method of using the polysulfone hollow fiber membrane of the present invention will be described. The hollow fiber membrane of the present invention exhibits excellent overpass performance particularly in the external pressure total overpass system. For example, when tap water is carefully passed through external pressure through the hollow fiber membrane of the present invention, any microorganisms can be removed, and pyrogen substances, which are said to be secreted by microorganisms, can be completely removed, resulting in pyrogen-free water. easily obtained. Moreover, the permeation rate tends to be much higher than that of conventional membranes that can cut pyrodiene. The reason why pyrogen removal and high permeation rate can be achieved at the same time with this simple system of total external pressure is that the hollow fiber membrane of the present invention has relatively large pores on the outer surface and is a sponge with a uniform internal structure. Because it has a skin layer with a dense slit-like structure on the inner surface, particles of submicron order or larger are captured on the outer surface, and substances containing dissolved polymers of submicron size or smaller are captured inside the membrane or on the inner surface. be done. That is, because the outer surface and inner structure act as prefilters, much higher permeation rates than those obtained with conventional hollow fiber membranes are obtained. In addition, the hollow fiber membrane of the present invention has a skin layer with a dense slit-like structure on the inner surface,
In the same way as ordinary hollow fiber membranes for ultraviolet filtration, it is also effective for internal pressure circulation type filtration. For example, it can be used to concentrate and recover polymers, remove COD components from wastewater, and can also be used in the medical field, especially as membranes for filtering or concentrating body fluids such as blood, plasma, and ascites. The present invention will be further explained below with reference to Examples. Example 1 20 parts by weight of polysulfone (Udel P-1700 manufactured by UCC), 36 parts by weight of polyethylene glycol with a molecular weight of 600 (PEG #600 manufactured by Sanyo Chemical Co., Ltd.) (addition amount of PEG #600 180% by weight/polysulfone) and 44 parts by weight of DMF. A slurry-like stock solution with white cloudy phase separation was obtained by heating and stirring at 120°C. A homogeneous and transparent stock solution was obtained by stirring the stock solution while cooling it to 25°C. Using a 6-hole annular nozzle, the spinning stock solution was degassed by standing overnight at 25℃, and DMF/DMF was used as the internal coagulation liquid.
Dry-wet spinning was performed while injecting a mixed solution containing water at a weight ratio of 80/20. At this time, the stock solution temperature during spinning was 25
℃, dry zone length is 10cm, dry zone atmosphere is 25℃, relative humidity is 60%, and external coagulation liquid is 20cm.
with water at ℃. Next, it was washed with water, rolled up into a 1.2 m flat frame, and then immersed in hot water at 100°C for 2 hours to remove polyethylene glycol and heat-treated. The obtained hollow fiber membrane has an outer diameter of 750μ and an inner diameter of 500μ, and its surface and cross section were examined using a scanning electron microscope (SEM).
As a result of observation, there were 35 micropores with an average size of 0.3μ on the outer surface.
%, the inner surface has a slit-like microporous structure with an average width of 0.04μ, and there are no large cavities larger than 10μ on the inner and outer surfaces and inside, and the interior is a sponge with an almost uniform mesh. It turns out that it has a structure. Also, the water permeability rate K A of pure water at 25℃ is
It was excellent at 1000/m 2・hr・Kg/cm 2 . Also 0.1
% of bovine serum γ globulin was over 99%, and the rejection rate of a 0.1% aqueous solution of standard polyethylene oxide (SE-150, manufactured by Toyo Soda) with a molecular weight of 1.2 million was also over 99%. In addition, the consolidation index α was determined by external pressure permeability measurements at 1Kg/cm 2 and 4Kg/cm 2 at 100℃.
was 0.15, which was small and good. Example 2 A hollow fiber membrane was obtained under the same conditions as in Example 1 except that water alone was used as the internal coagulation liquid. SEM of the surface and cross section of the obtained hollow fiber membrane
As a result of observation, there were micropores with an average size of 0.18μ on the outer surface.
It has an almost mesh-like structure with a porosity of 25%, and the inner surface has a slit-like microporous structure with an average width of 100 Å, and there are no voids larger than 10 μ on the inner and outer surfaces and inside, indicating that it has a sponge structure. Admitted. Also K A
was excellent at 730/ m2・hr・Kg/ cm2 . In addition, the rejection rate of bovine serum γ globulin and standard polyethylene oxide with a molecular weight of 1.2 million was over 98%. In addition, 3.5% of endotoxin E Coli 0127 B8 (manufactured by Difco Labo), a model substance of pyrodiene, was added to
After passing mg/dissolved water through a total external pressure system, the limulus test was negative not only in the initial flow but also after passing 100/m 2 , indicating that this hollow fiber membrane completely blocked pyrodiene.
In addition, the compaction index α was as small as 0.10, indicating excellent pressure resistance and heat resistance. Comparative example 1 DMF/water as internal coagulation liquid in weight ratio of 90/10
A hollow fiber membrane was obtained under the same conditions as in Example 1 except for using the mixed solution. However, the dry zone length was set to 1 cm because the spinning condition was unstable at 10 cm. SEM of the surface and cross section of the obtained hollow fiber membrane
As a result of observation, 30% of the outer surface had pores with an average size of 0.3μ.
, which was not much different from Examples 1 and 2, but the inner surface had irregularities or micropores on the order of 2μ, and did not have a slit-like microporous structure. The inner and outer surfaces and the inside had a sponge structure with no voids of 10μ or more. A photograph taken by SEM is shown in Figure 1. Also, K A is 1350/m 2・hr・Kg/
cm 2 , but the inhibition rate of bovine serum γ-globulin was extremely low at 5%. Furthermore, the water that had passed through the aqueous solution of endotoxin E Coli 0127 B8 was double positive in the Limulus test, indicating that the membrane did not block pyrodiene. Comparative Example 2 A hollow fiber membrane was obtained under the same conditions as in Example 2 except that the dry zone length was 0 cm (ie, wet spinning). As a result of observing the outer surface of the obtained hollow fiber membrane by SEM, no micropores of 0.1 μm or more were observed.
A photograph taken by SEM is shown in Fig. 2. The K A of this hollow fiber membrane was as low as 150/m 2 ·hr·Kg/cm 2 . Example 3 Polysulfone (UCC Udel P-1700) 4.0
Kg, polyethylene glycol with a molecular weight of 600 (PEG#600 manufactured by Sanyo Chemical) 6.8Kg (Additional amount of PEG#600 170
weight%/polysulfone), and DMF9.2Kg 120
The mixture was heated and stirred for 6 hours at a rotational speed of 450 rpm to obtain a slurry-like stock solution with white cloudy phase separation. The stock solution was cooled to 20°C while stirring to obtain a homogeneous transparent stock solution. When this stock solution was gradually heated again, it became sharply cloudy in a narrow temperature range around 35°C. When cooled to 20°C, it became completely transparent again, indicating reversibility. This stock solution was allowed to stand overnight at 20°C, and the transparent stock solution was subjected to dry-wet spinning using an 18-hole annular nozzle.
At this time, the jacket temperature of the raw solution piping from the spinning tank to the nozzle was controlled at 34° C. so that the raw solution was in a state just before phase separation into a cloudy state before the spinning solution was discharged from the nozzle. The dry zone length is 10cm, and the atmosphere in the dry zone is 25℃.
Air was blown at 5Nl/min so that the relative humidity was 50%. Also, both external coagulation liquid and internal coagulation liquid are at 20℃.
water. After washing with water and hot water, it was rolled up into a frame and immersed in hot water at 95°C for 1 hour in the form of a frame. The obtained hollow fiber membrane had an outer diameter of 700μ and an inner diameter of 450μ, and as a result of observing the surface and cross section with SEM, pores with an average size of 0.2μ existed on the outer surface with a porosity of 38%.
It was found that the inner surface has a slit-like micropore structure with an average width of 100 Å, and the inner and outer surfaces and interior have a sponge structure with no voids larger than 10 μm. SEM photographs are shown in Figures 3 to 6. Furthermore, K A was excellent at 770/m 2 ·hr · Kg/cm 2 . Also, bovine serum γ-globulin and molecular weight 120
Ten thousand standard polyethylene oxide rejection rate is 99%
That's all. In addition, the compaction index α in 100℃ hydrothermal water was excellent at 0.12. In addition, the obtained hollow fiber membrane was centrifugally bonded with urethane to create a small module with an effective length of 26 cm and a membrane area of 0.8 m 2 with a hole at one end (total length 33 cm, cylinder diameter 4 cmφ).
was created. This module and water-side PVC hose were soaked in 3% hydrogen peroxide solution overnight to sterilize and decompose pyrogen, and then connected to a tap water faucet in Kurashiki City, and the tap water was not pretreated in any way using a total external pressure method. I passed it directly without doing it. Overpressure is 1Kg/cm 2
It lasted 52 consecutive days. 1 hour, 1 day,
After 3 days, 7 days, 14 days, 21 days, 32 days, and 49 days, water was taken and a limulus test was performed, all of which were negative. For reference, when we conducted a Limulus test on tap water, all results were double positive. Therefore, it was found that pyrogen-free water can be easily obtained using the hollow fiber membrane of the present invention. Also, the water overspeed at this time is 2.8/
The temperature was 25°C. Using an extremely small module, we were able to continuously obtain a considerable amount of pyrogen-free water using a simple method that required no pretreatment, no pumps, or any other systems. When tap water is passed through a microporous polyvinyl alcohol hollow fiber membrane (SF-301 membrane made by Kuraray) and then passed through the hollow fiber membrane module of the present invention, the overspeed of the hollow fiber membrane module of the present invention becomes even greater, and of course it is pyrogen-free. It was hot. Example 4 20 parts by weight of polysulfone (Udel P-3500 manufactured by UCC), 36 parts by weight of polyethylene glycol with a molecular weight of 1000 (PEG #1000 manufactured by Sanyo Chemical Co., Ltd.) (Additional amount of PEG #1000 180% by weight/polysulfone) and 44 parts by weight of DMF. A homogeneous transparent stock solution was obtained by stirring at 25°C for 24 hours. After defoaming, a hollow fiber membrane was obtained in the same manner as in Example 2. SEM of the surface and cross section of the obtained hollow fiber membrane
As a result of observation, 35% of the outer surface had pores with an average size of 0.3μ.
It was found that the inner surface had a slit-like microporous structure with an average width of 200 Å, and the cross section had a sponge structure with no voids larger than 10 μ. Also, K A is 880/m 2・hr・Kg/
cm 2 and bovine serum γ-globulin, the inhibition rate was 97%, which was good. Example 5 The length of the dry zone was 10 cm, and the atmosphere in the dry zone was 40°C and the relative humidity was 95%.
The outer mold was made under the same conditions as in Example 3, except that air was blown for several minutes.
A hollow fiber membrane of 780μ and an inner diameter of 450μ was obtained. As a result of observing the surface and cross section of the obtained hollow fiber membrane using SEM, it was found that micropores with an average size of 0.35μ existed on the outer surface in an almost mesh shape with an aperture ratio of 48%, and the inner surface had a slit shape with an average width of 100 Å. It was found that the membrane has a microporous structure, and that the inner and outer surfaces and the inside of the membrane wall have a sponge structure with no voids larger than 10μ. The K A of this hollow fiber membrane was excellent at 740/m 2 ·hr·Kg/cm 2 . Furthermore, the rejection rate of bovine serum γ-globulin (IgG) and standard polyethylene oxide with a molecular weight of 1.2 million was 99% or more. In addition, endotoxin E
Results of checking the pyrogen content of water in which 3.5mg/dissolved Coli 0127 B8 (manufactured by Difco Labo) was passed through the external pressure method using a limulus test.
The concentration was 0.02 ng/ml or less, and it was confirmed that pyrogen was completely inhibited. In addition, the compaction index α was as small as 0.11, indicating excellent pressure resistance and heat resistance.
第１〜第６図は比較例１〜２および実施例３に
おいて得られたポリスルホン中空繊維膜の走査型
電子顕微鏡写真であり、第１図は比較例１の中空
繊維膜の内表面の構造（倍率10000）、第２図は比
較例２の中空繊維膜の外表面の構造（倍率
20000）、第３図は実施例３の中空繊維膜の断面構
造（倍率500）、第４図は第３図の中空繊維膜の内
表面の構造（倍率20000）、第５図は第３図の中空
繊維膜の外表面の構造（倍率20000）、および第６
図は第３図の中空繊維膜の内部（ほぼ中央部）の
構造（倍率10000）を示す。
Figures 1 to 6 are scanning electron micrographs of polysulfone hollow fiber membranes obtained in Comparative Examples 1 to 2 and Example 3, and Figure 1 shows the structure of the inner surface of the hollow fiber membrane of Comparative Example 1 ( Figure 2 shows the structure of the outer surface of the hollow fiber membrane of Comparative Example 2 (magnification: 10,000).
20,000), Figure 3 is the cross-sectional structure of the hollow fiber membrane of Example 3 (magnification: 500), Figure 4 is the structure of the inner surface of the hollow fiber membrane of Example 3 (magnification: 20,000), and Figure 5 is the structure of Figure 3. Structure of the outer surface of the hollow fiber membrane (20,000 magnification), and
The figure shows the structure (magnification: 10,000) inside (approximately the center) of the hollow fiber membrane in Figure 3.
Claims (1)
〓を有し、外表面に平均孔径1500〜3500Åの微孔
を開孔率10〜50％の割合で有し、膜内部が微細多
孔構造であり、かつ80Å以上の物質を実質的に透
過させず、透水速度が700〜6000／m2・hr・
Kg／cm2を示すポリスルホン中空繊維膜。 ２ 外表面の微孔の開孔率が20〜40％である特許
請求の範囲第１項記載のポリスルホン中空繊維
膜。 ３ 膜内部がスポンジ構造であり、内外両表面お
よび内部のいずれにおいても10μ以上の巨大空洞
が実質的に存在しない特許請求の範囲第１項また
は第２項記載のポリスルホン中空繊維膜。 ４ 分子量120万の標準ポリエチレンオキサイド
水溶液の阻止率が98％以上である特許請求の範囲
第１項〜第３項のいずれか１項記載のポリスルホ
ン中空繊維膜。 ５ 圧密化指数が0.2以下を示す特許請求の範囲
第１項〜第４項のいずれか１項記載のポリスルホ
ン中空繊維膜。[Scope of Claims] 1. The inner surface has slit-like micropores with an average width of 80 to 500 Å, and the outer surface has micropores with an average pore diameter of 1500 to 3500 Å at a porosity ratio of 10 to 50%. The interior has a microporous structure that does not substantially allow substances larger than 80 Å to permeate, and has a water permeation rate of 700 to 6000/ m2・hr・
Polysulfone hollow fiber membrane showing Kg/ cm2 . 2. The polysulfone hollow fiber membrane according to claim 1, wherein the porosity of the micropores on the outer surface is 20 to 40%. 3. The polysulfone hollow fiber membrane according to claim 1 or 2, wherein the inside of the membrane has a sponge structure, and there are substantially no large cavities of 10 μ or more on both the inner and outer surfaces and inside the membrane. 4. The polysulfone hollow fiber membrane according to any one of claims 1 to 3, which has a rejection rate of 98% or more for a standard polyethylene oxide aqueous solution having a molecular weight of 1.2 million. 5. The polysulfone hollow fiber membrane according to any one of claims 1 to 4, which has a compaction index of 0.2 or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21256781A JPS58114702A (en) | 1981-12-28 | 1981-12-28 | Polysulfone hollow fiber membrane and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21256781A JPS58114702A (en) | 1981-12-28 | 1981-12-28 | Polysulfone hollow fiber membrane and its production |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58114702A JPS58114702A (en) | 1983-07-08 |
| JPS6356802B2 true JPS6356802B2 (en) | 1988-11-09 |
Family
ID=16624831
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21256781A Granted JPS58114702A (en) | 1981-12-28 | 1981-12-28 | Polysulfone hollow fiber membrane and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58114702A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997034687A1 (en) * | 1996-03-21 | 1997-09-25 | Kaneka Corporation | Hollow yarn membrane used for blood purification and blood purifier |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58156018A (en) * | 1982-01-29 | 1983-09-16 | Asahi Chem Ind Co Ltd | Polysulfone resin hollow fiber |
| JPS58132111A (en) * | 1982-01-29 | 1983-08-06 | Asahi Chem Ind Co Ltd | Polysulfone hollow fiber |
| JPS59228017A (en) * | 1983-06-07 | 1984-12-21 | Nitto Electric Ind Co Ltd | Preparation of hollow yarn membrane of aromatic polysulfone |
| JPS59228016A (en) * | 1983-06-07 | 1984-12-21 | Nitto Electric Ind Co Ltd | Hollow yarn membrane of aromatic polysulfone |
| JPS60190204A (en) * | 1984-03-09 | 1985-09-27 | Sumitomo Bakelite Co Ltd | Modification of polysulfone resin membrane |
| JPS60222112A (en) * | 1984-04-20 | 1985-11-06 | Kanegafuchi Chem Ind Co Ltd | Hollow yarn-shaped filter and its manufacture |
| JP2527464B2 (en) * | 1988-06-29 | 1996-08-21 | ダイセル化学工業株式会社 | Hollow fiber membrane and method for producing ultrapure water |
| JP3232117B2 (en) | 1991-11-19 | 2001-11-26 | 鐘淵化学工業株式会社 | Polysulfone porous hollow fiber |
| US6355730B1 (en) | 1995-06-30 | 2002-03-12 | Toray Industries, Inc. | Permselective membranes and methods for their production |
| JP3551971B1 (en) | 2003-11-26 | 2004-08-11 | 東洋紡績株式会社 | Polysulfone permselective hollow fiber membrane |
| JP3580314B1 (en) | 2003-12-09 | 2004-10-20 | 東洋紡績株式会社 | Polysulfone-based selectively permeable hollow fiber membrane bundle and method for producing the same |
| JP3642065B1 (en) | 2004-03-22 | 2005-04-27 | 東洋紡績株式会社 | Permselective separation membrane and method for producing a selectively permeable separation membrane |
| EP1795254B1 (en) | 2004-08-10 | 2014-05-21 | Nipro Corporation | Process for production of a polysulfone type selectively permeable hollow fiber membrane module |
| JP5068479B2 (en) * | 2006-05-17 | 2012-11-07 | 旭化成ケミカルズ株式会社 | Oxidation-resistant hydrophilic polysulfone-based hollow fiber membrane and method for producing the same |
| WO2010029908A1 (en) * | 2008-09-10 | 2010-03-18 | 東レ株式会社 | Hollow-fiber membrane and process for production of hollow-fiber membrane |
| JP5578210B2 (en) * | 2012-08-27 | 2014-08-27 | 東洋紡株式会社 | Method for producing porous hollow fiber membrane |
| WO2015046411A1 (en) | 2013-09-30 | 2015-04-02 | 東レ株式会社 | Porous membrane, blood purifying module incorporating porous membrane, and method for producing porous membrane |
| CA3018047C (en) | 2016-03-31 | 2022-07-26 | Asahi Kasei Medical Co., Ltd. | Virus removal membrane and method for manufacturing virus removal membrane |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4051300A (en) * | 1973-09-03 | 1977-09-27 | Gulf South Research Institute | Hollow synthetic fibers |
| JPS53120684A (en) * | 1977-03-31 | 1978-10-21 | Mitsubishi Petrochem Co Ltd | Manufacture of filter membrane |
| JPS56152704A (en) * | 1980-04-25 | 1981-11-26 | Kanegafuchi Chem Ind Co Ltd | Hollow fiber membrane and its manufacture |
-
1981
- 1981-12-28 JP JP21256781A patent/JPS58114702A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4051300A (en) * | 1973-09-03 | 1977-09-27 | Gulf South Research Institute | Hollow synthetic fibers |
| JPS53120684A (en) * | 1977-03-31 | 1978-10-21 | Mitsubishi Petrochem Co Ltd | Manufacture of filter membrane |
| JPS56152704A (en) * | 1980-04-25 | 1981-11-26 | Kanegafuchi Chem Ind Co Ltd | Hollow fiber membrane and its manufacture |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997034687A1 (en) * | 1996-03-21 | 1997-09-25 | Kaneka Corporation | Hollow yarn membrane used for blood purification and blood purifier |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58114702A (en) | 1983-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS6356802B2 (en) | ||
| Dzinun et al. | Morphological study of co-extruded dual-layer hollow fiber membranes incorporated with different TiO2 loadings | |
| Yang et al. | Tailoring pore size and pore size distribution of kidney dialysis hollow fiber membranes via dual-bath coagulation approach | |
| US4612119A (en) | Hollow fiber filter medium and process for preparing the same | |
| JPH0122003B2 (en) | ||
| JP6694326B2 (en) | Composite membrane | |
| JPS58132111A (en) | Polysulfone hollow fiber | |
| CN103501878B (en) | Performance enhancing additives for fiber formation and polysulfone fibers | |
| EP1080777A1 (en) | Ultrafiltration membrane and method for producing the same, dope composition used for the same | |
| KR100557264B1 (en) | Hollow fiber membrane and process for producing the same | |
| JP3386904B2 (en) | Cellulose acetate hollow fiber separation membrane and method for producing the same | |
| JPH078549B2 (en) | Polyvinylidene fluoride-based resin porous membrane and method for producing the same | |
| JPH0478729B2 (en) | ||
| JP2703266B2 (en) | Polysulfone hollow fiber membrane and method for producing the same | |
| AU715033B2 (en) | Polyacrylonitrile-based filtration membrane in a hollow fiber state | |
| KR100581206B1 (en) | Polyvinylidene fluoride Porous Hollow Fiber Membrane and the Manufacturing Process thereof | |
| JPH03258330A (en) | Porous hollow fiber membrane | |
| JPH03284326A (en) | Porous hollow fiber membrane | |
| JPH078548B2 (en) | Polyvinylidene fluoride-based resin porous membrane and method for producing the same | |
| JP2688564B2 (en) | Cellulose acetate hollow fiber separation membrane | |
| JPH0468010B2 (en) | ||
| JPH0323647B2 (en) | ||
| JPS59228016A (en) | Hollow yarn membrane of aromatic polysulfone | |
| JP4672128B2 (en) | Hollow fiber membrane and method for producing the same | |
| JPS6156325B2 (en) |