JPH0676510B2 - Polysulfone porous membrane - Google Patents
Polysulfone porous membraneInfo
- Publication number
- JPH0676510B2 JPH0676510B2 JP61148192A JP14819286A JPH0676510B2 JP H0676510 B2 JPH0676510 B2 JP H0676510B2 JP 61148192 A JP61148192 A JP 61148192A JP 14819286 A JP14819286 A JP 14819286A JP H0676510 B2 JPH0676510 B2 JP H0676510B2
- Authority
- JP
- Japan
- Prior art keywords
- membrane
- pore size
- surface area
- specific surface
- filtration
- 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 - Lifetime
Links
- 239000012528 membrane Substances 0.000 title claims description 38
- 229920002492 poly(sulfone) Polymers 0.000 title claims description 12
- 239000011148 porous material Substances 0.000 claims description 36
- 239000012982 microporous membrane Substances 0.000 claims description 18
- 238000009826 distribution Methods 0.000 claims description 2
- 238000001914 filtration Methods 0.000 description 22
- 239000010410 layer Substances 0.000 description 17
- 239000002904 solvent Substances 0.000 description 14
- 238000005266 casting Methods 0.000 description 7
- 229920000642 polymer Polymers 0.000 description 7
- 239000002994 raw material Substances 0.000 description 6
- 239000011550 stock solution Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 4
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical class [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000008961 swelling Effects 0.000 description 4
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 3
- 239000002202 Polyethylene glycol Substances 0.000 description 3
- 239000012298 atmosphere Substances 0.000 description 3
- 238000005354 coacervation Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229920001223 polyethylene glycol Polymers 0.000 description 3
- 235000002639 sodium chloride Nutrition 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical class [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 238000005345 coagulation Methods 0.000 description 2
- 230000015271 coagulation Effects 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Chemical class 0.000 description 2
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 2
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 2
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 2
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical class [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 2
- 238000011045 prefiltration Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical class [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 2
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 2
- 239000004953 Aliphatic polyamide Substances 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 1
- 239000004695 Polyether sulfone Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical class [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 1
- 239000004280 Sodium formate Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229920003231 aliphatic polyamide Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 230000001112 coagulating effect Effects 0.000 description 1
- 235000019329 dioctyl sodium sulphosuccinate Nutrition 0.000 description 1
- YHAIUSTWZPMYGG-UHFFFAOYSA-L disodium;2,2-dioctyl-3-sulfobutanedioate Chemical compound [Na+].[Na+].CCCCCCCCC(C([O-])=O)(C(C([O-])=O)S(O)(=O)=O)CCCCCCCC YHAIUSTWZPMYGG-UHFFFAOYSA-L 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- GNOIPBMMFNIUFM-UHFFFAOYSA-N hexamethylphosphoric triamide Chemical compound CN(C)P(=O)(N(C)C)N(C)C GNOIPBMMFNIUFM-UHFFFAOYSA-N 0.000 description 1
- 239000002563 ionic surfactant Substances 0.000 description 1
- 239000004816 latex Substances 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 238000001471 micro-filtration Methods 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 239000005486 organic electrolyte Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000008238 pharmaceutical water Substances 0.000 description 1
- 229920001467 poly(styrenesulfonates) Polymers 0.000 description 1
- 229920006393 polyether sulfone Polymers 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 239000004323 potassium nitrate Chemical class 0.000 description 1
- 235000010333 potassium nitrate Nutrition 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- HNJBEVLQSNELDL-UHFFFAOYSA-N pyrrolidin-2-one Chemical compound O=C1CCCN1 HNJBEVLQSNELDL-UHFFFAOYSA-N 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000001632 sodium acetate Substances 0.000 description 1
- 235000017281 sodium acetate Nutrition 0.000 description 1
- 239000011780 sodium chloride Chemical class 0.000 description 1
- HLBBKKJFGFRGMU-UHFFFAOYSA-M sodium formate Chemical compound [Na+].[O-]C=O HLBBKKJFGFRGMU-UHFFFAOYSA-M 0.000 description 1
- 235000019254 sodium formate Nutrition 0.000 description 1
- 239000004317 sodium nitrate Chemical class 0.000 description 1
- 235000010344 sodium nitrate Nutrition 0.000 description 1
- 229940006186 sodium polystyrene sulfonate Drugs 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- HXJUTPCZVOIRIF-UHFFFAOYSA-N sulfolane Chemical compound O=S1(=O)CCCC1 HXJUTPCZVOIRIF-UHFFFAOYSA-N 0.000 description 1
- 229920001059 synthetic polymer Polymers 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 235000005074 zinc chloride Nutrition 0.000 description 1
- 239000011592 zinc chloride Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/66—Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
- B01D71/68—Polysulfones; Polyethersulfones
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
- B01D67/0013—Casting processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
- B01D67/0016—Coagulation
-
- 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
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/12—Specific ratios of components used
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/15—Use of additives
- B01D2323/16—Swelling agents
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
- B01D2325/022—Asymmetric membranes
Description
【発明の詳細な説明】 《産業上の利用分野》 本発明は液体の精密濾過に使用される微孔性膜に関す
る。更に詳しくは、本発明は濾過効率の良い微孔性膜に
関する。TECHNICAL FIELD The present invention relates to a microporous membrane used for microfiltration of liquids. More particularly, the present invention relates to microporous membranes with good filtration efficiency.
《従来の技術》 微孔性膜は古くから知られており、（例えばアール・ケ
スティング（R.Kesting）著シンセティック・ポリマー
・メンブラン（Synthetic Polymer Membrane）マグロウ
ヒル社（McGraw Hill社）発行）濾過用フィルター等に
広く利用されている。微孔性膜は、例えば米国特許第1,
421,341号、同3,133,132号、同2,944,017号、特公昭43
−15698号、特公昭45−3313号、同48−39586号、同48−
40050号等に記載されているように、セルローズエステ
ルを原料として製造されるもの、米国特許第2,783,894
号、同3,408,315号、同4,340,479号、同4,340,480号、
第4,450,126号、ドイツ特許DE3,138,525号、特開昭58−
37842号等に記載されているように脂肪族ポリアミドを
原料として製造されるもの、米国特許第4,196,070号、
同4,340,482号、特開昭55−99934号、特開昭58−91732
号等に記載されているようにポリフルオロカーボンを原
料として製造されるもの、ドイツ特許OLS3,003,400号等
に記載されているポリプロピレンを原料とするもの等が
ある。これらの微孔性膜は電子工業用洗浄水、医薬用
水、医薬製造工程用水、食品水等の濾過、滅菌に用いら
れ近年その用途と使用量は拡大しており、特に粒子捕捉
の点から信頼性の高い微孔性膜が注目されている。ポリ
スルホンを原料とした膜は、耐熱性及び耐薬品性に優れ
ているために特にその需要の伸びは著しい。<Prior art> Microporous membranes have been known for a long time (for example, R. Kesting's Synthetic Polymer Membrane issued by McGraw Hill) for filtration. Widely used for filters, etc. Microporous membranes are described, for example, in US Pat.
421,341, 3,133,132, 2,944,017, Japanese Patent Sho 43
-15698, Japanese Patent Publication No. 45-3313, 48-39586, 48-
No. 2,783,894 produced from cellulose ester as a raw material, as described in US Pat.
No. 3,408,315, 4,340,479, 4,340,480,
No. 4,450,126, German Patent DE 3,138,525, JP-A-58-
Those produced from aliphatic polyamide as a raw material as described in 37842, U.S. Pat.No. 4,196,070,
4,340,482, JP-A-55-99934, JP-A-58-91732
There are those produced from polyfluorocarbon as a raw material as described in No. 3, etc., and one using polypropylene as a raw material described in German Patent OLS 3,003,400. These microporous membranes are used for filtration and sterilization of electronic industrial washing water, pharmaceutical water, pharmaceutical manufacturing process water, food water, etc., and their applications and usages have been expanding in recent years, and are particularly reliable from the viewpoint of particle capture. A highly porous microporous membrane is drawing attention. Membranes made of polysulfone as a raw material have excellent heat resistance and chemical resistance, and thus the demand for them is particularly remarkable.
《発明が解決しようとする問題点》 一般に、微孔性膜の単位面積当たりの全濾過量すなわち
濾過寿命は短い。そこで膜面積を増すべく多くの濾過ユ
ニットを並列して使用することを余儀無くされており、
濾過工程のコストダウンの観点から、濾過寿命を上げる
事が当業界の技術的課題であった。<< Problems to be Solved by the Invention >> Generally, the total filtration amount per unit area of the microporous membrane, that is, the filtration life is short. Therefore, it is inevitable to use many filtration units in parallel to increase the membrane area.
From the viewpoint of reducing the cost of the filtration process, increasing the filtration life has been a technical issue in this industry.
この様な観点から、従来目づまり等による流量低下に有
効な膜として、特公昭55−6406号や特開昭56−145051号
に開示されているような、濾過液のインレット側からア
ウトレット側に向かって孔径が徐々に小さくなる非対称
膜が開発されている。この場合、特に膜の比表面積を大
きくすることが有効であることが知られており、セルロ
ース系の微孔性膜においては比表面積が8m2/g以上のも
のが良好であることも知られている。しかしながら、ポ
リスルホンを使用した場合には、従来、非対称性が極端
となり、比表面積を8m2/g以上とすることができず、従
って比表面積が8m2/g以上であるポリスルホン微孔性膜
は知られていない。From this point of view, as a conventional membrane effective in reducing the flow rate due to clogging, etc., from the inlet side of the filtrate to the outlet side as disclosed in JP-B-55-6406 and JP-A-56-145051. Asymmetric membranes with progressively smaller pore sizes have been developed. In this case, it is known that it is particularly effective to increase the specific surface area of the membrane, and it is also known that a cellulose-based microporous membrane having a specific surface area of 8 m 2 / g or more is good. ing. However, when polysulfone is used, conventionally, the asymmetry becomes extreme, and the specific surface area cannot be set to 8 m 2 / g or more. Therefore, a polysulfone microporous membrane having a specific surface area of 8 m 2 / g or more is unknown.
本発明者等は、濾過と目づまりの機構および比表面積と
濾過寿命との関係を解析し、膜の構造を極度に非対称
にすると膜の非表面積が小さくなり、最小孔径層以前の
インレット側の部分がプレフィルターとして有効に働か
ない事、及び捕捉される粒子は必ずしも粒子径より小
さな孔径部分で捕捉されるわけではなく、その多くは膜
の内部の壁面に付着して捕捉されているという事の２点
が、濾過寿命に関係した重要な因子となる事、従って、
極度な非対称膜を作らず、膜の比表面積を大きくするこ
とにより濾過寿命を延ばすことが合理的であることを見
い出し、更に鋭意研究した結果、最小孔径層を膜内部の
みに形成させることにより、ポリスルホン微孔性膜の場
合にも8m2/g以上の比表面積を実現することができ、こ
れによってポリスルホン微孔性膜の寿命を延ばすことが
できることを見い出し、本発明に到達した。The present inventors have analyzed the mechanism of filtration and clogging, and the relationship between the specific surface area and the filtration life, and when the structure of the membrane is extremely asymmetric, the non-surface area of the membrane becomes small, and the portion on the inlet side before the minimum pore size layer Does not work effectively as a pre-filter, and the trapped particles are not necessarily trapped in the pore size portion smaller than the particle diameter, and most of them are trapped by adhering to the inner wall surface of the membrane. Two points are important factors related to filtration life, and therefore,
It was found that it is rational to extend the filtration life by increasing the specific surface area of the membrane without forming an extremely asymmetric membrane, and as a result of further intensive research, by forming the minimum pore size layer only inside the membrane, The present inventors have found that a specific surface area of 8 m 2 / g or more can be realized even in the case of a polysulfone microporous membrane, which can prolong the life of the polysulfone microporous membrane, and arrived at the present invention.
従って本発明の目的は、微粒子ならびに細菌等を効率良
く捕捉することができる、濾過寿命の長いポリスルホン
微孔性膜を提供することにある。Therefore, an object of the present invention is to provide a polysulfone microporous membrane having a long filtration life, which can efficiently capture fine particles, bacteria and the like.
《問題を解決するための手段》 本発明の上記の目的は、最小孔径層を膜内部のみに有す
ると共に、膜の表面から裏面に向かって連続的に変化し
た非対称孔径分布を有するポリスルホン微孔性膜であっ
て、その比表面積が8m2/g以上であることを特徴とする
ポリスルホン微孔性膜によって達成された。<< Means for Solving the Problem >> The above-mentioned object of the present invention is to provide a polysulfone micropore having a minimum pore size layer only inside the membrane and having an asymmetric pore size distribution continuously changing from the front surface to the back surface of the membrane. Membrane, achieved by a polysulfone microporous membrane characterized by a specific surface area of 8 m 2 / g or more.
膜の比表面積に対し大きな寄与を示す孔径の小さな部分
を膜の最表面に形成することは、膜の開孔率を低くする
ので、十分な濾過流速を得るめに最小孔径層を薄くせね
ばならず、本発明の如く膜の比表面積を大きくしようと
する場合には、有利ではない。一方最小孔径層を表面よ
り深い部分に作った場合には、表面の孔径を大きくする
ことができる上、濾過抵抗を少なくすることができる。
しかも内部の最小孔径層部分は高い空孔率を確保でき、
濾過抵抗も小さいため、最小孔径層を厚くすることがで
きるのて、結果として大きな比表面積を得ることができ
る。Forming a small pore size portion that makes a large contribution to the specific surface area of the membrane on the outermost surface of the membrane lowers the porosity of the membrane, so the minimum pore size layer must be thinned in order to obtain a sufficient filtration flow rate. However, this is not advantageous when trying to increase the specific surface area of the membrane as in the present invention. On the other hand, when the minimum pore size layer is formed deeper than the surface, the pore size on the surface can be increased and the filtration resistance can be reduced.
Moreover, a high porosity can be secured in the minimum pore size layer inside,
Since the filtration resistance is also small, the minimum pore size layer can be thickened, and as a result, a large specific surface area can be obtained.
本発明の微孔性膜は、公知のポリスルホン及び／又はポ
リエーテルスルホンを原料とすることができる。The microporous membrane of the present invention can be made of known polysulfone and / or polyethersulfone as a raw material.
本発明においては、これらの中でも特に 又は の繰り返し単位で表されるポリマーが好ましい。In the present invention, among these, Or Polymers represented by repeating units of are preferred.
微孔性膜の製造は、上記ポリマーを良溶媒、良溶媒
と非溶媒の混合溶媒又はポリマーに対する溶解性の程
度が異なる複数種の溶媒の混合したものに溶解して製膜
原液を作製し、これを支持体上に、又は直接凝固液中に
流延し、洗浄、乾燥して行う。この場合に、ポリマーを
溶解する溶媒の一例としては、ジクロロメタン、ジメチ
ルホルムアミド、ジメチルアセトアミド、ジメチルスル
ホキシド、２−ピロリドン、Ｎ−メチル−２−ピロリド
ン、スルホラン、ヘキサメチルホスホルアミド等を挙げ
ることができる。Production of the microporous membrane, a good solvent, a good solvent, a mixed solvent of a good solvent and a non-solvent or a mixture of a plurality of solvents having different degrees of solubility to the polymer to prepare a membrane-forming stock solution, This is cast on a support or directly in a coagulating liquid, washed and dried. In this case, examples of the solvent that dissolves the polymer include dichloromethane, dimethylformamide, dimethylacetamide, dimethylsulfoxide, 2-pyrrolidone, N-methyl-2-pyrrolidone, sulfolane, and hexamethylphosphoramide. .
上記溶媒に添加する非溶媒の一例としては、セルソルブ
類、メタノール、エタノール、プロパノール、アセト
ン、ポリエチレングリコール、グリセリン等が挙げられ
る。非溶媒の良溶媒に対する割合は、混合溶液が均一状
態を保てる範囲ならばいかなる範囲でもよいが、５重量
％〜50重量％が好ましい。Examples of non-solvents added to the solvent include cellosolves, methanol, ethanol, propanol, acetone, polyethylene glycol, glycerin and the like. The ratio of the non-solvent to the good solvent may be any range as long as the mixed solution can maintain a uniform state, but is preferably 5% by weight to 50% by weight.
又、多孔構造を制御するものとして膨潤剤と称される無
機電解質、有機電解質、高分子又はその電解質等を加え
ることもできる。In addition, an inorganic electrolyte called an swelling agent, an organic electrolyte, a polymer, or an electrolyte thereof may be added to control the porous structure.
本発明で使用することのできる膨潤剤としては、塩化リ
チウム、塩化ナトリウム、硝酸ナトリウム、硝酸カリウ
ム、硫酸ナトリウム、塩化亜鉛等の無機酸の金属塩、酢
酸ナトリウム、ギ酸ナトリウム等の有機酸の金属塩、ポ
リスチレンスルホン酸ナトリウム、ポリビニルベンジル
トリメチルアンモニウムクロライド、ポリエチレングリ
コール、ポリビニルアルコール、ポリビニルピロリドン
等の高分子又はその電解質、ジオクチルスルホコハク酸
ナトリウム等のイオン系界面活性剤等が用いられる。こ
れらの膨潤剤は、単独でポリマー溶液に加えてもある程
度の効果を示すものであるが、これら電解質を水溶液と
して添加する場合には、特に顕著な効果を示す場合もあ
る。膨潤剤の添加量は添加によって溶液の均一性が失わ
れることがない限り特に制限はないが、通常、溶媒に対
して0.5重量％〜50重量％である。The swelling agent that can be used in the present invention, lithium chloride, sodium chloride, sodium nitrate, potassium nitrate, sodium sulfate, metal salts of inorganic acids such as zinc chloride, sodium acetate, metal salts of organic acids such as sodium formate, Polymers such as sodium polystyrene sulfonate, polyvinylbenzyltrimethylammonium chloride, polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone and the like, electrolytes thereof, ionic surfactants such as sodium dioctylsulfosuccinate and the like are used. These swelling agents show some effect when added alone to the polymer solution, but when adding these electrolytes as an aqueous solution, they may show particularly remarkable effects. The addition amount of the swelling agent is not particularly limited as long as the addition does not lose the homogeneity of the solution, but is usually 0.5% by weight to 50% by weight with respect to the solvent.
製膜原液としてのポリマー溶液の濃度は５〜35重量％、
好ましくは、10〜30重量％である。35重量％を越える
と、得られる微孔性膜の透水性が実用的な意味を持たな
い程小さくなり、又５重量％より低い濃度では十分な分
離能を持った微孔性膜は得られない。The concentration of the polymer solution as a film forming stock solution is 5 to 35% by weight,
It is preferably 10 to 30% by weight. If it exceeds 35% by weight, the water permeability of the obtained microporous membrane becomes so small as to have no practical meaning, and if the concentration is less than 5% by weight, a microporous membrane having sufficient separation ability can be obtained. Absent.
本発明の微孔性膜は、上記の如くして得られた製膜原液
を支持体上に流延し、溶媒蒸気の蒸発量と雰囲気からの
非溶媒蒸気吸収量を適宜調節することにより製造するこ
とができる。このような調整は、製膜原液は支持体上に
流延し、例えば絶対湿度2gH2O/kgAir以上の空気を0.2m/
sec以上の風速で流延面に当てることによって行われ
る。これによって、流延面の最表面層から１μｍ以上、
好ましくは５μｍ以上の深さにコアセルベーション相を
形成させる。その後直ちに凝固浴槽に浸漬し多孔性膜を
形成させる。このようにして得られた膜は、流延直後に
空気の雰囲気、あるいは非溶媒雰囲気中に保持した後凝
固浴に浸漬する公知の方法と異なり、コアセルベーショ
ンを起こさせた部分の最深部が最小孔径層となる。The microporous membrane of the present invention is produced by casting the stock solution for membrane formation obtained as described above on a support and appropriately adjusting the evaporation amount of solvent vapor and the non-solvent vapor absorption amount from the atmosphere. can do. In such adjustment, the stock solution for film formation is cast on a support, and for example, air having an absolute humidity of 2 gH 2 O / kg Air or more is 0.2 m / m2.
It is performed by hitting the casting surface at a wind speed of sec or more. As a result, 1 μm or more from the outermost surface layer of the casting surface,
Preferably, the coacervation phase is formed at a depth of 5 μm or more. Immediately thereafter, it is immersed in a coagulation bath to form a porous film. The film obtained in this manner is different from the known method in which it is immersed in an air atmosphere immediately after casting or in a non-solvent atmosphere and then immersed in a coagulation bath. It is the smallest pore size layer.
この方法は流延後表面層のみにコアセルベーション相を
形成させる事を特徴とするものであり、流延する以前の
製膜原液を相分離状態にさせておく特開昭56−154051号
に記載の方法の場合とも異なる。This method is characterized by forming a coacervation phase only in the surface layer after casting, and disclosed in JP-A-56-154051 in which the membrane-forming stock solution before casting is allowed to be in a phase-separated state. It differs from the method described.
本発明の微孔製膜は、最表面層に最も孔径の小さな部分
を形成させたものではなく、膜の内部に最小孔径層を形
成させたものである。これは、膜内部に最小孔径層を有
する場合の方が、膜表面の孔径が大きく、濾過抵抗を小
さくすることができるからである。このことは、比表面
積に大きく寄与する最小孔径層の厚みを大きく設計する
ことが可能となることを意味する。このように最小孔径
層を膜内部に形成せしめた場合であっても、表面の孔径
と裏面の孔径の比は10〜100倍程度であり、BET法で測定
したその比表面積は８〜80m2/gにも及び。口過効率の観
点からは、特に比表面積が15m2/g〜80m2/gのものが好ま
しく、製造効率をも加味すると、20m2/g〜60m2/gとする
ことが好ましい。The microporous membrane of the present invention does not have a portion having the smallest pore diameter formed on the outermost surface layer, but has a smallest pore diameter layer formed inside the membrane. This is because when the membrane has a minimum pore size layer, the pore size on the membrane surface is larger and the filtration resistance can be reduced. This means that the thickness of the minimum pore size layer, which greatly contributes to the specific surface area, can be designed to be large. Even when the minimum pore size layer is formed inside the film, the ratio of the pore size on the front surface to the pore size on the back surface is about 10 to 100 times, and the specific surface area measured by the BET method is 8 to 80 m 2. It also extends to / g. From the viewpoint of the mouth over efficiency, in particular the specific surface area thereof is preferably 15m 2 / g~80m 2 / g, when considering also the production efficiency, it is preferable to 20m 2 / g~60m 2 / g.
《発明の効果》 本発明の膜は、孔径の大きな面をインレット側として濾
過を行うことにより、粒子捕捉に当たりプレフィルター
効果を十分に発揮する。又、比表面積が大きいため微細
粒子が最小孔径部分に到達する以前に吸着又は付着によ
って除かれる効果が大きく、濾過寿命を大きく改善する
ことができる。<< Effects of the Invention >> The membrane of the present invention sufficiently exhibits a pre-filter effect in capturing particles by performing filtration with the surface having a large pore size as the inlet side. Further, since the specific surface area is large, the effect of removing fine particles by adsorption or adhesion before reaching the minimum pore size portion is great, and the filtration life can be greatly improved.
以下、本発明を実施例に従って更に詳述するが、本発明
はこれによって限定されるものではない。Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.
実施例1. ポリスルホン（UCC社Ｐ−3500）15部、Ｎ−メチルピロ
リドン60部、ポリエレングリコール15部、ポリビニルピ
ロリドン５部、LiCl5部よりなる製膜原液をガラス板上
に厚さ150μｍに流延し、相対湿度40％、温度25℃、風
速0.7m/secの風を15秒間流延面に当て、表面にコアセル
ベーション相を形成させた後、25℃の水中へ浸漬し凝固
させ微孔製膜を得た。この膜の表面の孔径は0.5〜１μ
ｍ、裏面の孔径は１μｍ〜10μｍであり最小孔径層の平
均孔径は0.15μｍで、比表面積は41m2/gであった。また
断面を電子顕微鏡で観察すると最小孔径層を有する部分
は膜内部に持つ事が判った。Example 1. A film-forming stock solution comprising 15 parts of polysulfone (P-3500 manufactured by UCC Co., Ltd., P-3500), 60 parts of N-methylpyrrolidone, 15 parts of polyethylene glycol, 5 parts of polyvinylpyrrolidone, and 5 parts of LiCl was flowed to a thickness of 150 μm on a glass plate. Spread, apply a relative humidity of 40%, a temperature of 25 ° C, and a wind speed of 0.7 m / sec to the casting surface for 15 seconds to form a coacervation phase on the surface, then immerse it in water at 25 ° C to solidify it. A porous film was obtained. The pore size of the surface of this membrane is 0.5-1μ
m, the pore size of the back surface was 1 μm to 10 μm, the average pore size of the minimum pore size layer was 0.15 μm, and the specific surface area was 41 m 2 / g. Also, when the cross section was observed with an electron microscope, it was found that the portion having the minimum pore size layer was inside the film.
比較例 実施例1.の溶液をガラス板上に150μｍの厚さに流延し
直ちに25℃の水中に浸漬し微孔性膜を得た。この膜は表
面の平均孔径0.15μｍ、裏面の平均孔径10〜100μｍで
あり、比表面積は5m2/gであった。電子顕微鏡の断面写
真から最小孔径を有する部分が最表面に存在することが
確認された。Comparative Example The solution of Example 1 was cast on a glass plate to a thickness of 150 μm and immediately immersed in water at 25 ° C. to obtain a microporous membrane. This membrane had an average pore diameter of 0.15 μm on the front surface, an average pore diameter of 10 to 100 μm on the back surface, and a specific surface area of 5 m 2 / g. It was confirmed from the cross-sectional photograph of the electron microscope that the portion having the smallest pore size was present on the outermost surface.
実施例2. 実施例１の本発明の膜と比較例の膜について濾過テスト
を行った。Example 2 A filtration test was performed on the inventive membrane of Example 1 and the comparative membrane.
ポリスチレンラテック（平均粒径0.17μｍ）を0.01％含
有する水溶液を、差圧0.1kgとして濾過を行った結果、
比較例の膜は500ml/cm2で実質的に目づまりを起こした
のに対し、本発明の膜は1200ml/cm2まで濾過が可能であ
り、本発明の膜の濾過寿命が大幅に改善されていること
が実証された。An aqueous solution containing 0.01% of polystyrene latex (average particle size 0.17 μm) was filtered with a differential pressure of 0.1 kg,
The membrane of Comparative Example caused substantial clogging at 500 ml / cm 2 , whereas the membrane of the present invention was capable of filtering up to 1200 ml / cm 2 , and the filtration life of the membrane of the present invention was significantly improved. It was proved that
実施例3. 実施例１で風を当てる時間を変化させた時の最小孔径層
の深さと比表面積を第１図に示した。これにより、最小
孔径層を膜内部に作る程大きな比表面積の膜が得られる
ことが判る。Example 3 FIG. 1 shows the depth and specific surface area of the minimum pore size layer when the time of applying the air was changed in Example 1. From this, it is understood that a film having a larger specific surface area can be obtained by forming the minimum pore size layer inside the film.
第１図は実施例３で得られた、微孔性膜の比表面積と、
最小孔径層が生ずる深さとの関係を示すグラフである。FIG. 1 shows the specific surface area of the microporous membrane obtained in Example 3,
It is a graph which shows the relationship with the depth which a minimum pore diameter layer produces.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭60−250049（ＪＰ，Ａ) 特開 昭59−58041（ＪＰ，Ａ) 特開 昭56−126408（ＪＰ，Ａ) 特公 昭56−35489（ＪＰ，Ｂ２) ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-60-250049 (JP, A) JP-A-59-58041 (JP, A) JP-A-56-126408 (JP, A) JP-B-56- 35489 (JP, B2)
Claims (1)
膜の表面から裏面に向かって連続的に変化した非対称孔
径分布を有するポリスルホン微孔性膜であって、その比
表面積が8m2/g以上であることを特徴とするポリスルホ
ン微孔性膜。1. A minimum pore size layer is provided only inside the membrane, and
A polysulfone microporous membrane having a asymmetric pore size distribution that continuously changes from the front surface to the back surface of the membrane, the specific surface area of which is 8 m 2 / g or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61148192A JPH0676510B2 (en) | 1986-06-26 | 1986-06-26 | Polysulfone porous membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61148192A JPH0676510B2 (en) | 1986-06-26 | 1986-06-26 | Polysulfone porous membrane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS636033A JPS636033A (en) | 1988-01-12 |
| JPH0676510B2 true JPH0676510B2 (en) | 1994-09-28 |
Family
ID=15447311
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61148192A Expired - Lifetime JPH0676510B2 (en) | 1986-06-26 | 1986-06-26 | Polysulfone porous membrane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0676510B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008006327A (en) * | 2006-06-27 | 2008-01-17 | Daicel Chem Ind Ltd | Hollow fiber porous membrane and membrane-forming composition |
| KR100950931B1 (en) | 2007-11-13 | 2010-04-01 | 웅진케미칼 주식회사 | Manufacturing method of polyethersulfone membrane with highly asymmetric structure and its product |
| CN110479121A (en) * | 2019-07-30 | 2019-11-22 | 三达膜科技（厦门）有限公司 | A kind of preparation method of polyether sulfone/thermo plastic polyurethane alastic body alloy inner support hollow membrane |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5635489A (en) * | 1979-08-30 | 1981-04-08 | Sharp Corp | Semiconductor laser element |
| JPS5831204B2 (en) * | 1980-03-10 | 1983-07-05 | 日東電工株式会社 | polysulfone semipermeable membrane |
| JPS588516A (en) * | 1981-07-08 | 1983-01-18 | Toyobo Co Ltd | Preparation of polysulfone separation membrane |
| JPS5958041A (en) * | 1982-09-28 | 1984-04-03 | Teijin Ltd | Preparation of porous polysulfone membrane |
| JPS59228016A (en) * | 1983-06-07 | 1984-12-21 | Nitto Electric Ind Co Ltd | Hollow yarn membrane of aromatic polysulfone |
-
1986
- 1986-06-26 JP JP61148192A patent/JPH0676510B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS636033A (en) | 1988-01-12 |
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