GB2047161A - Hollow fiber form polycarbonate membrane for use in dialysis and process for producing same - Google Patents
Hollow fiber form polycarbonate membrane for use in dialysis and process for producing same Download PDFInfo
- Publication number
- GB2047161A GB2047161A GB7918189A GB7918189A GB2047161A GB 2047161 A GB2047161 A GB 2047161A GB 7918189 A GB7918189 A GB 7918189A GB 7918189 A GB7918189 A GB 7918189A GB 2047161 A GB2047161 A GB 2047161A
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- United Kingdom
- Prior art keywords
- hollow fiber
- membrane
- tubular extrudate
- fiber form
- polyether
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- 239000012528 membrane Substances 0.000 title claims abstract description 83
- 239000012510 hollow fiber Substances 0.000 title claims abstract description 49
- 239000004417 polycarbonate Substances 0.000 title claims abstract description 35
- 229920000515 polycarbonate Polymers 0.000 title claims abstract description 35
- 238000000502 dialysis Methods 0.000 title claims abstract description 26
- 238000000034 method Methods 0.000 title claims abstract description 17
- 230000035699 permeability Effects 0.000 claims abstract description 36
- 229920001400 block copolymer Polymers 0.000 claims abstract description 29
- 230000001112 coagulating effect Effects 0.000 claims abstract description 29
- 239000007788 liquid Substances 0.000 claims abstract description 29
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000002344 surface layer Substances 0.000 claims abstract description 17
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims abstract description 16
- 229930003779 Vitamin B12 Natural products 0.000 claims abstract description 11
- 239000011715 vitamin B12 Substances 0.000 claims abstract description 11
- 235000019163 vitamin B12 Nutrition 0.000 claims abstract description 11
- 239000011780 sodium chloride Substances 0.000 claims abstract description 8
- 102000008100 Human Serum Albumin Human genes 0.000 claims abstract description 6
- 108091006905 Human Serum Albumin Proteins 0.000 claims abstract description 6
- 230000002093 peripheral effect Effects 0.000 claims abstract description 5
- 230000001747 exhibiting effect Effects 0.000 claims abstract description 3
- FDJOLVPMNUYSCM-WZHZPDAFSA-L cobalt(3+);[(2r,3s,4r,5s)-5-(5,6-dimethylbenzimidazol-1-yl)-4-hydroxy-2-(hydroxymethyl)oxolan-3-yl] [(2r)-1-[3-[(1r,2r,3r,4z,7s,9z,12s,13s,14z,17s,18s,19r)-2,13,18-tris(2-amino-2-oxoethyl)-7,12,17-tris(3-amino-3-oxopropyl)-3,5,8,8,13,15,18,19-octamethyl-2 Chemical compound [Co+3].N#[C-].N([C@@H]([C@]1(C)[N-]\C([C@H]([C@@]1(CC(N)=O)C)CCC(N)=O)=C(\C)/C1=N/C([C@H]([C@@]1(CC(N)=O)C)CCC(N)=O)=C\C1=N\C([C@H](C1(C)C)CCC(N)=O)=C/1C)[C@@H]2CC(N)=O)=C\1[C@]2(C)CCC(=O)NC[C@@H](C)OP([O-])(=O)O[C@H]1[C@@H](O)[C@@H](N2C3=CC(C)=C(C)C=C3N=C2)O[C@@H]1CO FDJOLVPMNUYSCM-WZHZPDAFSA-L 0.000 claims abstract 2
- IISBACLAFKSPIT-UHFFFAOYSA-N Bisphenol A Natural products C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 claims description 8
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 7
- 239000002904 solvent Substances 0.000 claims description 7
- 239000002202 Polyethylene glycol Substances 0.000 claims description 5
- 229920001223 polyethylene glycol Polymers 0.000 claims description 5
- 229920000642 polymer Polymers 0.000 description 18
- AGVAZMGAQJOSFJ-WZHZPDAFSA-M cobalt(2+);[(2r,3s,4r,5s)-5-(5,6-dimethylbenzimidazol-1-yl)-4-hydroxy-2-(hydroxymethyl)oxolan-3-yl] [(2r)-1-[3-[(1r,2r,3r,4z,7s,9z,12s,13s,14z,17s,18s,19r)-2,13,18-tris(2-amino-2-oxoethyl)-7,12,17-tris(3-amino-3-oxopropyl)-3,5,8,8,13,15,18,19-octamethyl-2 Chemical compound [Co+2].N#[C-].[N-]([C@@H]1[C@H](CC(N)=O)[C@@]2(C)CCC(=O)NC[C@@H](C)OP(O)(=O)O[C@H]3[C@H]([C@H](O[C@@H]3CO)N3C4=CC(C)=C(C)C=C4N=C3)O)\C2=C(C)/C([C@H](C\2(C)C)CCC(N)=O)=N/C/2=C\C([C@H]([C@@]/2(CC(N)=O)C)CCC(N)=O)=N\C\2=C(C)/C2=N[C@]1(C)[C@@](C)(CC(N)=O)[C@@H]2CCC(N)=O AGVAZMGAQJOSFJ-WZHZPDAFSA-M 0.000 description 9
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 8
- 239000000654 additive Substances 0.000 description 7
- 238000001631 haemodialysis Methods 0.000 description 7
- 230000000322 hemodialysis Effects 0.000 description 7
- WNXJIVFYUVYPPR-UHFFFAOYSA-N 1,3-dioxolane Chemical compound C1COCO1 WNXJIVFYUVYPPR-UHFFFAOYSA-N 0.000 description 6
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 6
- 230000000996 additive effect Effects 0.000 description 6
- DDRJAANPRJIHGJ-UHFFFAOYSA-N creatinine Chemical compound CN1CC(=O)NC1=N DDRJAANPRJIHGJ-UHFFFAOYSA-N 0.000 description 6
- 229960002668 sodium chloride Drugs 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 229920001202 Inulin Polymers 0.000 description 5
- 229920000297 Rayon Polymers 0.000 description 5
- JYJIGFIDKWBXDU-MNNPPOADSA-N inulin Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)OC[C@]1(OC[C@]2(OC[C@]3(OC[C@]4(OC[C@]5(OC[C@]6(OC[C@]7(OC[C@]8(OC[C@]9(OC[C@]%10(OC[C@]%11(OC[C@]%12(OC[C@]%13(OC[C@]%14(OC[C@]%15(OC[C@]%16(OC[C@]%17(OC[C@]%18(OC[C@]%19(OC[C@]%20(OC[C@]%21(OC[C@]%22(OC[C@]%23(OC[C@]%24(OC[C@]%25(OC[C@]%26(OC[C@]%27(OC[C@]%28(OC[C@]%29(OC[C@]%30(OC[C@]%31(OC[C@]%32(OC[C@]%33(OC[C@]%34(OC[C@]%35(OC[C@]%36(O[C@@H]%37[C@@H]([C@@H](O)[C@H](O)[C@@H](CO)O%37)O)[C@H]([C@H](O)[C@@H](CO)O%36)O)[C@H]([C@H](O)[C@@H](CO)O%35)O)[C@H]([C@H](O)[C@@H](CO)O%34)O)[C@H]([C@H](O)[C@@H](CO)O%33)O)[C@H]([C@H](O)[C@@H](CO)O%32)O)[C@H]([C@H](O)[C@@H](CO)O%31)O)[C@H]([C@H](O)[C@@H](CO)O%30)O)[C@H]([C@H](O)[C@@H](CO)O%29)O)[C@H]([C@H](O)[C@@H](CO)O%28)O)[C@H]([C@H](O)[C@@H](CO)O%27)O)[C@H]([C@H](O)[C@@H](CO)O%26)O)[C@H]([C@H](O)[C@@H](CO)O%25)O)[C@H]([C@H](O)[C@@H](CO)O%24)O)[C@H]([C@H](O)[C@@H](CO)O%23)O)[C@H]([C@H](O)[C@@H](CO)O%22)O)[C@H]([C@H](O)[C@@H](CO)O%21)O)[C@H]([C@H](O)[C@@H](CO)O%20)O)[C@H]([C@H](O)[C@@H](CO)O%19)O)[C@H]([C@H](O)[C@@H](CO)O%18)O)[C@H]([C@H](O)[C@@H](CO)O%17)O)[C@H]([C@H](O)[C@@H](CO)O%16)O)[C@H]([C@H](O)[C@@H](CO)O%15)O)[C@H]([C@H](O)[C@@H](CO)O%14)O)[C@H]([C@H](O)[C@@H](CO)O%13)O)[C@H]([C@H](O)[C@@H](CO)O%12)O)[C@H]([C@H](O)[C@@H](CO)O%11)O)[C@H]([C@H](O)[C@@H](CO)O%10)O)[C@H]([C@H](O)[C@@H](CO)O9)O)[C@H]([C@H](O)[C@@H](CO)O8)O)[C@H]([C@H](O)[C@@H](CO)O7)O)[C@H]([C@H](O)[C@@H](CO)O6)O)[C@H]([C@H](O)[C@@H](CO)O5)O)[C@H]([C@H](O)[C@@H](CO)O4)O)[C@H]([C@H](O)[C@@H](CO)O3)O)[C@H]([C@H](O)[C@@H](CO)O2)O)[C@@H](O)[C@H](O)[C@@H](CO)O1 JYJIGFIDKWBXDU-MNNPPOADSA-N 0.000 description 5
- 229940029339 inulin Drugs 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000002964 rayon Substances 0.000 description 5
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 4
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 4
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 4
- 229960001760 dimethyl sulfoxide Drugs 0.000 description 4
- 239000012153 distilled water Substances 0.000 description 4
- 238000001125 extrusion Methods 0.000 description 4
- 229920001281 polyalkylene Polymers 0.000 description 4
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 3
- 239000008280 blood Substances 0.000 description 3
- 210000004369 blood Anatomy 0.000 description 3
- 239000004202 carbamide Substances 0.000 description 3
- 229940109239 creatinine Drugs 0.000 description 3
- 239000012046 mixed solvent Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 230000008961 swelling Effects 0.000 description 3
- 229940045136 urea Drugs 0.000 description 3
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical group O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 229920001515 polyalkylene glycol Polymers 0.000 description 2
- -1 polypropylene Polymers 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- 102000009027 Albumins Human genes 0.000 description 1
- 108010088751 Albumins Proteins 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-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
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000023555 blood coagulation Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229930188620 butyrolactone Natural products 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 150000002009 diols Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 210000003734 kidney Anatomy 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 210000000056 organ Anatomy 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920001983 poloxamer Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000012085 test solution Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
- 238000005406 washing Methods 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
- B01D71/76—Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74
- B01D71/80—Block polymers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
- B01D63/02—Hollow fibre modules
- B01D63/021—Manufacturing thereof
-
- 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
- B01D69/081—Hollow fibre membranes characterised by the fibre diameter
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/24—Formation of filaments, threads, or the like with a hollow structure; Spinnerette packs therefor
-
- 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
- B01D71/50—Polycarbonates
-
- 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
- B01D71/52—Polyethers
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Textile Engineering (AREA)
- External Artificial Organs (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Artificial Filaments (AREA)
Abstract
A polyether-polycarbonate block copolymer dialysis membrane in the form of a hollow fiber having an inner diameter of 100-500 microns. The membrane possesses inner and outer dense surface layers and has a membrane thickness of 5-40 microns, and is characterized as exhibiting, as measured at 37 DEG C, a diffusive permeability coefficient to sodium chloride of 700x10<-4> -950x10<-4> cm/min., a diffusive permeability coefficient to vitamin B12 of 80 x10<-4>-150x10<-4> cm/min. and a permeability to water of 2-10 ml/ m<2>.hr.mmHg, and being substantially impermeable to human albumin. The membrane is produced by a method wherein a polyether-polycarbonate block copolymer solution is extruded through a circular orifice into the atmosphere while a coagulating liquid is forced inside the tubular extrudate so that the tubular extrudate is stretched in the peripheral direction; then, the tubular extrudate is passed through the atmosphere for a predetermined period of time, and; then, introduced into a bath of a coagulating liquid, thereby to be coagulated.
Description
SPECIFICATION
Hollow fiber form polycarbonate membrane for use in dialysis and process for producing same
BACKGROUND OF THE INVENTION
Field of the invention
This invention relates to a dialysis membrane in the form of a hollow fiber made of a polyetherpolycarbonate block copolymer, which membrane exhibits a preferential permeability, and a process for producing the same.
Description of the prior art
Hemodialysis membranes widely used at the present time are generally in the form of a hollow fiber or a flat film made of cuproammonium rayon. The cuproammonium rayon hemodialysis membranes are not completely satisfactory in that they are poor in permeability to middle molecular weight substances and in mechanical strength in a wet state. The term "middle molecular weight substances", used herein, refers to substances which have a molecular weight in the range of from approximately 1,000 to approximately 5,000.
Hemodialysis membranes in the form of a flat film made of a polyether-polycarbonate block copolymer have been proposed in Trans. Amer. Soc. Artif. Int. Organs, Vol XXI, page 144(1975), British Patent 1,500,937, Japanese Laid-open Patent Application 116,692/1977 and U.S. Patent 4,069,151. These references teach that a hemodialysis membrane made by casting a polyether-polycarbonate block copolymer solution on a flat base is capable of prefentially removing middle molecular weight substances. Flat film form hemodialysis membranes, which include those of a polyether-polycarbonate block copolymer, have the following deficiencies. First, the membranes are stored generally in a roll form, and hence, blocking tends to be caused between the adjacent membranes, which blocking causes trouble in the fabrication of the artificial kidney.Secondly, when the membranes are used in a Kiil type dialyzer, the dialysis efficiency is low and the amount of blood remaining in the dialyzer undesirably increases and adversely affects patients. Thus, it has been desired to develop polyether-polycarbonate membranes in the form of a hollow fiber.
When hollow fiber form membranes are used in a dialyzer, blood is introduced inside the hollow fiber in order to obtain the desired dialysis efficiency and the amount of blood primed, and to prevent blood-coagulation. It is, therefore, very desirable to develop a hollow fiber form polyether-polycarbonate membrane having a dense inner surface layer. However, it is difficult to form a dense inner surface layer in a hollow fiber by a method wherein the solvent is removed by evaporation from the inner surface of the tubular extrudate. It is also difficult to obtain a hollow fiber form membrane, which exhibits dialysis properties similar to those of a flat film form membrane, by a method wherein the tubular extrudate travels in the atmosphere for a certain period of time, e.g. one to five minutes, for the evalzoration of the solvent therefrom.
It now has been found that a thin dense inner surface layer can be produced in a hollow fiber form polyether-polycarbonate membrane without evaporation of the solvent from the inner surface of the tubular extrudate by forcing a coagulating liquid at a high pressure inside the tubular extrudate. It has also been found that the denseness of both inner and outer surfaces of a hollow fiber form polyether-polycarbonate membrane can suitably be controlled by expanding the tubular extrudate in the radial direction thereof, i.e., stretching the tubular extrudate in the peripheral direction thereof, by the pressure of a coagulating liquid forced inside the tubular extrudate.
Summary of the invention
In one aspect of the present invention, there is provided a hollow fiber form dialysis membrane composed of a polyether-polycarbonate block copolymer and having an inner diameter of from 100 to 500 microns and a membrane thickness of from 5 to 40 microns; said membrane having inner and outer dense surface layers and exhibiting, as measured at a temperature of 37 C, a diffusive permeability coefficient to sodium chloride of from 700x 10-# to 950x10-# cm/min., a diffusive permeability coefficient to vitamin B12 of from 80x 10-# to 150x10-4cm/min. and a permeability to water of from 2to 10 ml/m2.hr.mmHg,and being substantially impermeable to human albumin.
In another aspect of the present invention, there is provided a process for producing a hollow fiber form dialysis membrane which comprises the steps of:
extruding a solution of a polyether-polycarbonate block copolymer in a solvent, miscible with first and second coagulating liquids mentioned below, through a circular orifice into the atmosphere while the first coagulating liquid is forced inside the tubular extrudate so that the tubular extrudate is stretched in the peripheral direction, and, then,
passing the tubular extrudate through the atmosphere for a predetermined period of time, and, then,
introducing the tubular extrudate into a bath of the second coagulating liquid whereby the tubular extrudate is coagulated.
Description of the preferred embodiments
The hollow fiber form polyether-polycarbonate block copolymer membrane of the invention has thin and dense inner and outer surface layers integrated with the sandwiched thick and relatively non-dense medial layer. The inner and outer dense surface layers are significantly different from the sandwiched relatively non-dense medial layer. In this respect, the membrane of the invention may be referred to as being "anisotropic". The dense surface layers govern the permeability properties of the membrane, and usually have a thickness of from approximately 0.01 to approximately 0.5 micron, as measured by using a scanning type electron microscope. The membrane of the invention exhibits enhanced efficiency of dialysis of middle molecular weight substances.Thus, the diffusive permeability to sodium chloride, as measured at a temperature of 37 C, is in the range of from 700x10-4to 950xlO-4cm/min., particularly in the range of from 750 to 900 cm/min. The diffusive permeability to vitamin B12 at 370C is in the range offrom BOX 1 #-# to 1 50x 10-4 cm/min., particularly in the range of from 90x 10-4 to 1 50x 10-4 cm/min. The diffusive permeability to inulin at 370C is generally in the range of from 17x10-4to 25x10-4 cm/min.
Furthermore, the hollow fiber form membrane of the invention is characterized as possessing appropriately controlled permissible ultrafiltration rates. Thus, the membrane is substantially impermeable to human-albumin. The permeability to water is in the range of from 2 to 10 mI/m2.hr.mmHg, particularly in the range of from 2 to 7 ml/m2.hr.mmHg, as measured at a temperature of 37 C. This permeability to water is considerably low in contrast to the desirably enhanced dialysis properties. Therefore, the hollow fiber form membrane of the invention is useful in not only hemodialysis but, also, other general dialyses.
The hollow fiber form membrane of the invention is also satisfactory in mechanical strength. For example, the burst strength is generally in the range of from 5 to 10 kg/cm2, which is approximately from 12 to 25 times the burst strength (e.g. 0.4 kg/cm2) of a conventional flat film form polyether-polycarbonate membrane.
The polyether-polycarbonate block copolymer used for the production of the membrane of the invention is comprised of polyalkylene ether carbonate units and bisphenol A carbonate units. Such block copolymers are known and may be prepared, for example, by the method of Goldberg: Journal of Polymer Science, Part
C, No.4, pp 707-730(1963) wherein a comonomer mixture of bisphenol A and polyalkylene glycol, such as polyethylene glycol or polypropylene glycol, is reacted with a carbonic acid derivative, such as phosgene.
Polyetherglycols other than polyalkylene glycols can also be used, such as polypropylene oxidepolyethylene oxide block copolymers as exemplified by members of the Pluronic diol series ("Piuronic" is a
Registered Trade Mark). The polyether-polycarbonate block copolymer is preferably comprised of approximately 5 to 45% by weight, particularly approximately 10 to 35% by weight, of polyalkylene ether carbonate units and approximately 55 to 95% by weight, particularly 65 to 90% by weight, of bisphenol A carbonate units. When the amount of the polyalkylene ether carbonate units is less than approximately 5% by weight, the block copolymer is not sufficiently hydrophilic to be suitable for use as a hemodialysis membrane. In contrast, when the amount of the polyalkylene ether carbonate units is too great, the block copolymer is rendered elastomeric.
The polyether-polycarbonate block copolymer used preferably possesses a viscosity average molecular weight of from approximately 50,000 to approximately 750,000, particularly from approximately 200,000 to approximately 500,000.
The hollow fiber form membrane of the invention is produced as follows.
The polyether-polycarbonate block copolymer is dissolved in a solvent to prepare a polymer dope. The solvent used may be selected from organic solvents which are capable of dissolving therein the polyether-polycarbonate block copolymer and miscible with the coagulating liquid used, such as water.
Such organic solvents include, for example, 1 4-dioxane, 1 3-dioxane, 1 ,3-dioxolan, tetrahydrofuran and
butyrolactone. Of these 1,3-dioxolan is optimum. In addition to the organic solvent, an additive having a swelling function for the block copolymer, such as dimethyl-sulfoxide, dimethylacetamide or dimethylformamide, may be used for the preparation of the polymer dope, in an amount such that the additive does not adversely affect the formation of the thin dense surface layers. The addition of such an additive enhances the permeability of the resulting membrane. It should be noted, however, that the use of an excessive amount of such an additive prevents the formation of the dense surface layers during the time the tubular extrudate is
passed through the atmosphere and then through a bath of the second coagulating liquid.
It is also possible to incorporate in the polymer dope an additive having little or no swelling function for the block copolymer, such as glycerin, ethylene glycol and polyethylene glycol. The addition of such an additive controls the permeability of the resulting membrane. Furthermore, it is also possible to incorporate
in the polymer dope an alcohol having a low boiling point in order to accelerate the formation of the dense surface layers in the resulting membrane.
The concentration of the block copolymer in the polymer dope may be varied depending upon the
intended physical and permeability properties of the resulting membrane. Usually, the copolymer concentration is in the range of from 5 to 35% by weight, to give dopes ranging in viscosity from 2,000 to
100,000 cps, as measured at a temperature of 25 C.
The polymer dope is extruded through a circular orifice into the atmosphere while a first coagulating liquid
is forced inside the tubular extrudate, so that the tubular extrudate is expanded in the radial direction, i.e., stretched in the peripheral direction. A nozzle of the type which is conventionally used for the production of
hollow fibers and which is provided with a coagulating liquid inlet tube in the center of the circular orifice
may be used.
The first coagulating liquid to be forced inside the tubular extrudate includes, for example, water, ethylene glycol and propylene glycol. Of these water is preferable in view of easiness in handling, safety and economy. Additives, such as swelling agents hereinbefore mentioned and inorganic salts, may be added to the first coagulating liquid.
If no coagulating liquid is introduced inside the tubular extrudate, the inner diameter of the tubular extrudate is smaller than the inner diameter of the circular orifice. When the coagulating liquid is forced inside the tubular extrudate, the inner diameter of the tubular extrudate is rendered larger than the inner diameter of the circular orifice immediately after being extruded through the orifice, and thereafter, the inner diameter of the tubular extrudate gradually decreases due to the drafting force applied to the tubular extrudate. The dialysis properties of the resulting membrane varies depending upon the degree of stretching. Generally, the greater the degree of stretching, the more enhanced the dialysis properties of the resulting membrane.It is preferable then that the first coagulating liquid be forced inside the tubular extrudate at a pressure of from 0.02 to 1.0 kg/cm2 so that the maximum diameter of the tubular extrudate, which is reached immediately after it is extruded through the orifice, will be larger than the diameter of the circular orifice but will not exceed five times of the diameter of the circular orifice. It should be noted, however, that the degree of stretching can be varied depending upon, not only the pressure of the first coagulating liquid to be forced inside the tubular extrudate, but also, the extrusion rate of the polymer dope and the speed of winding up the resulting membrane.
The tubular extrudate is passed through the atmosphere for a predetermined period of time, and then, introduced into a bath of a second coagulating liquid, whereby the tubular extrudate is coagulated. By varying the period of time spanning from the extrusion of the polymer dope into the atmosphere to the introduction of the tubular extrudate into the coagulating bath, the desired dense outer surface layer can be formed in the membrane and the permeability properties, particularly permeability to water, of the membrane can be suitably controlled. Generally, the dense outer surface layer is readily formed by passing the tubular extrudate through the atmosphere only for an extremely short period of time.The period of time, during which the extrudate travels through the atmosphere, is generally in the range of from 0.5 to 12 seconds, more preferably in the range of from 1.5 to 10 seconds.
The second coagulating liquid into which the tubular extrudate is introduced may be selected from those which are herein before listed with respect to the first coagulating liquid to be forced inside the tubular extrudate. Water is most preferable.
The dense outer surface layer formed by the immersion of the tubular extrudate in the bath of the second coagulation liquid is effective not only for suitably controlling the permeability to water but, also, for rendering the resulting membrane easy to handle. If the membrane has no dense outer surface layer, undesirable blocking would occur between the adjacent membranes during storing.
The hollow fiber form membrane fabricated as described above may be stored as it is in a wet state.
Alternatively, the wet membrane may be immersed in a glycerin solution and, then, air dried to be stored in a dry state. In order to modify the physical and permeability properties of the membrane, the membrane may be subjected to heat treatment and/or drawing in the hollow fiber axis direction by a procedure popularly employed for the production of conventional dialysis membranes.
The invention will be further illustrated by the following examples, wherein percentages are by weight unless otherwise specified.
In the examples, the permeability of the membrane was determined at a temperature of 37 C by using a dialysis test apparatus of the type designed according to the National Bureau of Standards. The concentrations of the test solutions were as follows.
Sodium chloride 10,000 ppm
Urea 1,000 ppm
Creatinin 300 ppm
Vitamin B12 100 ppm
Inulin 50 ppm
Human-albumin 1,000 ppm
Example 1
65 g of a polyether-polycarbonate block copolymer comprised of 25% of polyethylene glycol carbonate units and 75% of bisphenol A carbonate units, and having an intrinsic viscosity [ "rl ] of 2.3, as measured in chloroform at 25"C, were dissolved in 435 g of 1,3-dioxolane to prepare a polymer dope. The polymer dope was extruded through a circular orifice of a nozzle, of the type which was conventionally used for the production of hollow fibers, into the atmosphere with a temperature of 25 C, while distilled water was forced inside the tubular extrudate at a pressure of approximately 0.1 kg/cm2. The extrusion speed was 7.5 m/minute.The circular orifice of the nozzle had an inner diameter of 0.2 mm and an outer diameter of 0.4 mm. The inner wall of the circular orifice was formed by a needle-like coagulating liquid inlet tube through which distilled water was forced inside the tubular extrudate. The coagulating liquid inlet tube was provided in the center of the nozzle and had an inner diameter of 0.1 mm. After traveling through the atmosphere for approximately one second, the tubular extrudate was introduced into a water bath maintained at a temperature of 25 C, whereby the tubular extrudate was coagulated from the outer periphery thereof, in addition to from the inner periphery thereof, to form a membrane in the form of a hollow fiber. The hollow fiber was passed through a washing water bath and wound up, by using a winder, at a speed of 7.5 m/minute.After the water present inside the hollow fiber was removed therefrom, the hollow fiber was washed well with distilled water, and then, stored in a wet state.
Observation of a cross-section of the hollow fiber form membrane with a transmission type electron microscope showed that the membrane had inner and outer dense surface layers. The dialysis properties of the hollow fiber form membrane for sodium chloride, urea, creatinine, vitamin B12, inulin and albumin, and the water permeability and physical properties of the membrane are shown in Table I, below. For purposes of comparison corresponding values are also shown for a typical sample of a hollow fiber form cuproammonium rayon membrane.
TABLE I
Polyether-polycarbonate Cuproammonium
hollow fiber rayon hollowfiber Inner diameterl 240/280 260/300 outer diameter (microns)
Diffusive permeability (cm/min.) to:
Sodium chloride 850 x 10-4 750 x 10-4
(MW=58)
Urea 830 x 10-4 690 x 10-4
(MW=60)
Creatinine 460 x 10-4 370 x 10-4
(MW=113)
Vitamin B12 95 x 10-4 40 x 10-4 (my 1,335) Inulin 20 x 10-4 4.2 x 10-4 (MW=5,200)
Human-albumin 0 0
(MW=6,0000)
Water permeability 3.0 x 10-4 2.2 x 10-4 (ml/m2 hr mmHg)
Wet burst strength 6.5 15 (kg/cm2)
As is apparent from the test data in Table I, the hollow fiber form polyether-polycarbonate membrane of the invention exhibits, compared with a conventional hollow fiber form cuproammonium rayon membrane, far enhanced permeability to middle molecular weight substances such as vitamin B12 and inulin, and possesses a clinically acceptable permeability to water.
Examples 2 through 4
65 g of a polyether-polycarbonate block copolymer similar to that used in Example 1 were dissolved in a mixed solvent comprised of 422 g of 1,3-dioxolane and 13 g of dimethylsulfoxide to prepare a polymer dope.
Hollow fiber form polyether-polycarbonate membranes were produced from the polymer dope in a manner similar to that mentioned in Example 1, except that the pressure, under which distilled water was forced into the tubular extrudate, was varied as shown in Table II, below. All other conditions remained substantially the same. The dialysis properties of the resultant hollow fiber form polyether-polycarbonate membranes are shown in Table II, below.
TABLE II
Inner diameter/ Diffusive permeability
Example Pressure outer diameter (cm/min.)
No. (kg/cm2) (microns) Sodium Vitamin B12
chloride
2 0.15 280/320 900 x 10-4 120 x 10-4
3 0.08 265/295 750 x 10-4 102 x 10-4
4 0.05 220/256 700 x 10-4 95 x 10-4
Examples 5 through 9
65 g of a polyether-polycarbonate block copolymer similar to that used in Example 1 were dissolved in a mixed solvent comprised of 422 g of 1,3-dioxolane and 13 g of dimethylsulfoxide to prepare a polymer dope.
Hollow fiber form polyether-polycarbonate membranes were produced from the polymer dope in a manner similarto that mentioned in Example 1, except that the time period for which the tubular extrudate was passed through the atmosphere was varied as shown in Table Ill, below. All other conditions remained substantially the same. The permeability properties of the resultant hollow fiber form polyetherpolycarbonate membranes are shown in Table Ill, below.
TABLE Ill
Time Inner diameter/ Water Diffusive perme
Example period outer diameter permeability ability vitamin B12
No. (sec.) (microns) (ml/m2 hr mmHg) (cm/min.)
5 0.56 220/260 8.9 150 x 10-4
6 1.7 225/265 5.3 120 x 10-4
7 3.7 225/265 4.9 117x104 8 5.4 210/250 3.6 125 x 10-4
9 7.1 220/256 3.4 95 x 10-4
Example 10
87 g of a polyether-polycarbonate block copolymer comprised of 25% of polyethylene glycol carbonate units and 75% of bisphenol A carbonate units and having an intrinsic viscosity [ 11 ] of 1.7, as measured in chloroform at 25"C, were dissolved in a mixed solvent comprised of 563 g of 1,3-dioxolane and 17 g of dimethylsulfoxide to prepare a polymer dope. A hollow fiber form polyether-polycarbonate membrane was produced from the polymer dope in a manner similar to that mentioned in Example 1, wherein the following conditions were employed with all other conditions remaining substantially the same.
Extrusion speed of the polymer dope: 15 m/min.
Time period during which the tubular extrudate was passed through the atmosphere: 5 sec.
Winding speed: 15 m/min.
The permeability properties of the resultant hollow fiber form polyether-polycarbonate membrane are shown in Table IV, below.
TABLE IV
Inner diameter/outer diameter (microns) 220/260
Membrane thickness (microns) 20
Water permeability (ml/m2 hr mmHg) 4.4
Diffusive permeability (cm/min) to
Sodium chloride 796 x 10-4
Creatinine 468 x 10-4 Vitamin B12 118 x 10-4
Claims (14)
1. A hollow fiber form dialysis membrane composed of a polyether-polycarbonate block copolymer and having an inner diameter of from 100 to 500 microns and a membrane thickness of from 5 to 40 microns; said membrane having inner and outer dense surface layers and exhibiting, as measured at a temperature of 37 C, a diffusive permeability coefficient to sodium chloride of from 700x 10-4 to 950X 10-4 cm/min., a diffusive permeability coefficient to vitamin B12 of from 80x10-4to 1 50X 1 #-# cm/min. and a permeability to water of from 2 to 10 mI/m2'hr.mmHg, and being substantially impermeable to human albumin.
2. A hollow fiber form dialysis membrane according to claim 1 wherein the polyether-polycarbonate block copolymer is comprised of approximately from 10 to 35% by weight of polyalkylene-ether carbonate units and approximately from 65 to 90% by weight of bisphenol A carbonate units.
3. A hollow fiber form dialysis membrane according to claim 2 wherein the polyalkylene-ether is polyethylene glycol.
4. A hollow fiber form dialysis membrane according to any one of claims 1 to 3, wherein the membrane thickness is substantially uniform.
5. A process for producing a hollow fiber form dialysis membrane which comprises the steps of:
extruding a solution of a polyether-polycarbonate block copolymer in a solvent, miscible with first and second coagulating liquids mentioned below, through a circular orifice into the atmosphere, while the first coagulating liquid is forced inside the tubular extrudate so that the tubular extrudate is stretched in the peripheral direction;
passing the tubular extrudate through the atmosphere for a predetermined period of time; and, then,
introducing the tubular extrudate into a bath of the second coagulating liquid, whereby the tubular extrudate is coagulated.
6. A process according to claim 5, wherein the polyether-polycarbonate block copolymer is comprised of approximately from 10 to 35% by weight of polyalkylene-ether carbonate units and approximately from 65 to 90% by weight of bisphenol A carbonate units.
7. A process according to claim 5 or 6 wherein the first coagulating liquid is water.
8. A process according to claim 5 or 6 wherein the second coagulating liquid is water.
9. A process according to claim 5 or 6 wherein the first coagulating liquid is forced inside the tubular extrudate at a pressure of from 0.02 to 1.0 kg/cm2.
10. A process according to claim 5 or 6 wherein the tubular extrudate is passed through the atmosphere for a period of from 0.5 to 12 seconds.
11. A process according to Claim 5 substantially as described in any one of the Examples.
12. A hollow fiber form dialysis membrane obtained by a process according to any one of claims 5 to 11.
13. A hollow fiber form dialysis membrane according to Claim 1 substantially as described in any one of the Examples.
14. A dialysis unit comprising hollow fiber form dialysis membranes according to any one of Claims 1 to 4,12or13.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP431179A JPS5596162A (en) | 1979-01-18 | 1979-01-18 | Polycarbonate hollow fiber dialysis film and its preparation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2047161A true GB2047161A (en) | 1980-11-26 |
| GB2047161B GB2047161B (en) | 1983-01-12 |
Family
ID=11580932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7918189A Expired GB2047161B (en) | 1979-01-18 | 1979-05-24 | Hollow fibre form polycarbonate membrane for use in dialysis and process for producing same |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS5596162A (en) |
| DE (1) | DE2921138C2 (en) |
| GB (1) | GB2047161B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4563516A (en) * | 1983-08-19 | 1986-01-07 | Bayer Aktiengesellschaft | Polyether-polycarbonates for dialysis membranes |
| US4812269A (en) * | 1985-03-07 | 1989-03-14 | Gambro Dialysatoren Kg | Process for producing hollow fiber semi-permeable membranes |
| US4935140A (en) * | 1982-11-16 | 1990-06-19 | Gambro Dialysatoren Kg | Membrane and process for producing the membrane |
| EP2394679A1 (en) * | 2009-02-04 | 2011-12-14 | Toyo Boseki Kabushiki Kaisha | Hollow-fiber membrane, process for producing same, and blood purification module |
| CN104906972A (en) * | 2015-05-20 | 2015-09-16 | 苏州市贝克生物科技有限公司 | Nano-grade titanium dioxide/polyether hemodialysis membrane and preparation method thereof |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE423106B (en) * | 1980-07-25 | 1982-04-13 | Gambro Dialysatoren | PLASMAFERES MEMBRANE AND WAY TO MANUFACTURE THIS |
| ATE10437T1 (en) * | 1980-09-01 | 1984-12-15 | Gambro, Inc. | DRY POLYCARBONATE MEMBRANE AND METHOD OF MANUFACTURE. |
| EP0046816A1 (en) * | 1980-09-01 | 1982-03-10 | Gambro, Inc. | Polycarbonate hemofiltration membrane and method of hemofiltering using such a membrane |
| SE429441B (en) * | 1982-04-30 | 1983-09-05 | Gambro Dialysatoren | MICROPOROST HALFIBERMENBRAN FOR PLASMAFERES, AS WELL AS MANUFACTURING THE MEMBRANE |
| SE8204103L (en) * | 1982-07-02 | 1984-01-03 | Gambro Lundia Ab | FILTRATION MEMBRANE AND SET TO MAKE THE MEMBRANE |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL107052C (en) * | 1957-05-06 | 1900-01-01 | ||
| US3423491A (en) * | 1964-09-02 | 1969-01-21 | Dow Chemical Co | Permselective hollow fibers and method of making |
| JPS5193786A (en) * | 1975-02-15 | 1976-08-17 | Makurokagatano chukuseni | |
| US4061821A (en) * | 1975-12-29 | 1977-12-06 | Asahi Kasei Kogyo Kabushiki Kaisha | Semipermeable composite membranes |
| CA1107467A (en) * | 1976-03-19 | 1981-08-25 | Paul A. Cantor | Polycarbonate membranes for use in hemodialysis |
| US4069151A (en) * | 1976-03-31 | 1978-01-17 | C. R. Bard, Inc. | Thin polycarbonate membranes for use in hemodialysis |
| JPS6029282B2 (en) * | 1976-09-03 | 1985-07-10 | 旭化成株式会社 | Semipermeable membrane and its manufacturing method |
-
1979
- 1979-01-18 JP JP431179A patent/JPS5596162A/en active Granted
- 1979-05-24 GB GB7918189A patent/GB2047161B/en not_active Expired
- 1979-05-25 DE DE2921138A patent/DE2921138C2/en not_active Expired
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4935140A (en) * | 1982-11-16 | 1990-06-19 | Gambro Dialysatoren Kg | Membrane and process for producing the membrane |
| US4563516A (en) * | 1983-08-19 | 1986-01-07 | Bayer Aktiengesellschaft | Polyether-polycarbonates for dialysis membranes |
| US4812269A (en) * | 1985-03-07 | 1989-03-14 | Gambro Dialysatoren Kg | Process for producing hollow fiber semi-permeable membranes |
| EP2394679A1 (en) * | 2009-02-04 | 2011-12-14 | Toyo Boseki Kabushiki Kaisha | Hollow-fiber membrane, process for producing same, and blood purification module |
| CN102307603A (en) * | 2009-02-04 | 2012-01-04 | 东洋纺织株式会社 | Hollow-fiber membrane, process for producing same, and blood purification module |
| EP2394679A4 (en) * | 2009-02-04 | 2013-07-17 | Toyo Boseki | Hollow-fiber membrane, process for producing same, and blood purification module |
| US8840788B2 (en) | 2009-02-04 | 2014-09-23 | Toyo Boseki Kabushiki Kaisha | Hollow fiber membrane, method for manufacturing the same, and blood purification module |
| CN102307603B (en) * | 2009-02-04 | 2015-04-22 | 东洋纺织株式会社 | Hollow-fiber membrane, process for producing same, and blood purification module |
| CN104906972A (en) * | 2015-05-20 | 2015-09-16 | 苏州市贝克生物科技有限公司 | Nano-grade titanium dioxide/polyether hemodialysis membrane and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2921138C2 (en) | 1983-10-20 |
| JPS6333871B2 (en) | 1988-07-07 |
| JPS5596162A (en) | 1980-07-22 |
| DE2921138A1 (en) | 1980-07-24 |
| GB2047161B (en) | 1983-01-12 |
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| Date | Code | Title | Description |
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| PCNP | Patent ceased through non-payment of renewal fee |