GB2035133A - A modified membrane for membrane filtration - Google Patents
A modified membrane for membrane filtration Download PDFInfo
- Publication number
- GB2035133A GB2035133A GB7933477A GB7933477A GB2035133A GB 2035133 A GB2035133 A GB 2035133A GB 7933477 A GB7933477 A GB 7933477A GB 7933477 A GB7933477 A GB 7933477A GB 2035133 A GB2035133 A GB 2035133A
- Authority
- GB
- United Kingdom
- Prior art keywords
- membrane
- solution
- modified
- organic solvent
- polymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000012528 membrane Substances 0.000 title claims abstract description 83
- 238000005374 membrane filtration Methods 0.000 title claims abstract description 14
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical group OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 51
- 229920000642 polymer Polymers 0.000 claims abstract description 29
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 25
- 229920001577 copolymer Polymers 0.000 claims abstract description 24
- 239000002904 solvent Substances 0.000 claims abstract description 4
- 239000011248 coating agent Substances 0.000 claims description 15
- 238000000576 coating method Methods 0.000 claims description 15
- 150000001875 compounds Chemical class 0.000 claims description 12
- 239000003495 polar organic solvent Substances 0.000 claims description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 9
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 6
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 2
- 125000003158 alcohol group Chemical group 0.000 claims 1
- 229920002678 cellulose Polymers 0.000 claims 1
- 239000012530 fluid Substances 0.000 claims 1
- 239000011118 polyvinyl acetate Substances 0.000 abstract description 9
- 229920002689 polyvinyl acetate Polymers 0.000 abstract description 8
- 239000002798 polar solvent Substances 0.000 abstract description 3
- 239000000243 solution Substances 0.000 description 23
- 229920002301 cellulose acetate Polymers 0.000 description 17
- 230000004907 flux Effects 0.000 description 10
- 238000011282 treatment Methods 0.000 description 10
- 230000014759 maintenance of location Effects 0.000 description 8
- 229940075065 polyvinyl acetate Drugs 0.000 description 8
- 229940117958 vinyl acetate Drugs 0.000 description 8
- 238000001029 thermal curing Methods 0.000 description 6
- LDHQCZJRKDOVOX-NSCUHMNNSA-N crotonic acid Chemical compound C\C=C\C(O)=O LDHQCZJRKDOVOX-NSCUHMNNSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 208000029422 Hypernatremia Diseases 0.000 description 3
- 125000000217 alkyl group Chemical group 0.000 description 3
- 150000001735 carboxylic acids Chemical class 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 3
- LDHQCZJRKDOVOX-UHFFFAOYSA-N trans-crotonic acid Natural products CC=CC(O)=O LDHQCZJRKDOVOX-UHFFFAOYSA-N 0.000 description 3
- VZCYOOQTPOCHFL-OWOJBTEDSA-N Fumaric acid Chemical compound OC(=O)\C=C\C(O)=O VZCYOOQTPOCHFL-OWOJBTEDSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229920001519 homopolymer Polymers 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 238000001223 reverse osmosis Methods 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 2
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 2
- 239000001124 (E)-prop-1-ene-1,2,3-tricarboxylic acid Substances 0.000 description 1
- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 description 1
- 229920002972 Acrylic fiber Polymers 0.000 description 1
- XLYMOEINVGRTEX-ARJAWSKDSA-N Ethyl hydrogen fumarate Chemical compound CCOC(=O)\C=C/C(O)=O XLYMOEINVGRTEX-ARJAWSKDSA-N 0.000 description 1
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229940091181 aconitic acid Drugs 0.000 description 1
- 150000001253 acrylic acids Chemical class 0.000 description 1
- 150000008064 anhydrides Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 235000012206 bottled water Nutrition 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- GTZCVFVGUGFEME-IWQZZHSRSA-N cis-aconitic acid Chemical compound OC(=O)C\C(C(O)=O)=C\C(O)=O GTZCVFVGUGFEME-IWQZZHSRSA-N 0.000 description 1
- 150000001991 dicarboxylic acids Chemical class 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 239000012527 feed solution Substances 0.000 description 1
- 239000001530 fumaric acid Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 1
- 229940098895 maleic acid Drugs 0.000 description 1
- 239000011976 maleic acid Substances 0.000 description 1
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 125000005641 methacryl group Chemical group 0.000 description 1
- GBMDVOWEEQVZKZ-UHFFFAOYSA-N methanol;hydrate Chemical compound O.OC GBMDVOWEEQVZKZ-UHFFFAOYSA-N 0.000 description 1
- LVHBHZANLOWSRM-UHFFFAOYSA-N methylenebutanedioic acid Natural products OC(=O)CC(=C)C(O)=O LVHBHZANLOWSRM-UHFFFAOYSA-N 0.000 description 1
- 150000002763 monocarboxylic acids Chemical class 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
- GTZCVFVGUGFEME-UHFFFAOYSA-N trans-aconitic acid Natural products OC(=O)CC(C(O)=O)=CC(O)=O GTZCVFVGUGFEME-UHFFFAOYSA-N 0.000 description 1
- 150000003628 tricarboxylic acids Chemical class 0.000 description 1
- 229920003176 water-insoluble polymer Polymers 0.000 description 1
- 235000005074 zinc chloride Nutrition 0.000 description 1
- 239000011592 zinc chloride Substances 0.000 description 1
- 229960001939 zinc chloride Drugs 0.000 description 1
Classifications
-
- 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
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0088—Physical treatment with compounds, e.g. swelling, coating or impregnation
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
A modified membrane for membrane filtration is obtained by contacting a membrane surface of a non-thermally cured membrane with a solution containing a water insoluble copolymer or polymer and an organic polar solvent. Preferably the polar arganic solvent is methanol and the polymer a polyvinylacetate.
Description
SPECIFICATION
A modified membrane for membrane filtration
The invention relates to a modified membrane for membrane filtration, obtained by treating a
membrane surface with a water insoluble hydrofilic polymer compound.
A membrane of this type is known. Cellulose acetate membranes for reverse osmosis, used to prepare potable water from seawater are, after a long use of said membranes, treated with an aqueous ammoniacal solution of a copolymer of vinylacetate with a maleicacid-ethylester, the membrane after having been immersed into the polymer solution, being subsequently treated with a diluted aqueous hydrochloric acid solution, having a pH of 4 and containing 1% by weight of zincchloride. Hereby the copolymer precipitates upon the membrane.
Said known method offers the disadvantage that the ammoniacal solution will hamper the capacity of the membranes, in particular that of cellulose acetate membranes, whilst on the other hand membranes are treated having initially undergone a certain thermal curing treatment so as to give the desired porosity to said membranes.
In the state of the art it is also known to treat cellulose acetate membranes with a solution consisting of a copolymer or poly-vinylacetate with 5% of crotonic acid, whereby said copolymer is dissolved in an ammoniacal aqueous solution, whilst said copolymer is subsequently made insoluble by acidification.
Said copolymer is likewise applied upon a membrane of cellulose acetate which has initially undergone a thermal treatment.
It has been found that, although cellulose acetate membranes having been subjected to a thermal curing treatment at lower temperatures, could be coated with a copolymer coating, said copolymer coating is easily removed during subsequent use of the membranes.
It is a further disadvantage of the two methods for coating a cellulose acetate membrane with a polymer coating, as mentioned hereinbefore, that only polymers can be used being soluble in water, so that a polyvinylacetate first has to be modified and converted into a copolymer being soluble in water. From the foregoing it is evident that the use of polyvinyl acetate as a polymer coating upon said cellulose acetate membranes, is impossible, owing to the insolubility of polyvinyl acetate in water.
Summarizing the above features, it is clearly evident that the methods as mentioned hereinbefore firstly require the use of initially thermally treated membranes, secondly the preparation of copolymers being soluble in water and the application of said aqueous copolymers by means of an ammoniacal solution, which is followed by a precipitation of the copolymer with an acid and metal ions.
Nothwithstanding these features, said membranes appear to have a less longer lifespan in practice, which is possibly connected with an insufficient adherence of the polymer coating upon said membranes, mostly being a cellulose acetate membrane.
The present invention aims to provide a modified membrane to be used in a membrane filtration, obtained by treating a membrane surface, with a solution of a water insoluble hydrofilic polymer compound, whereby membranes are obtained having a long lifespan in practice. A water insoluble polymer compound is in this case a polymer compound not being soluble in pure water.
This object is obtained in accordance with the invention in that the modified membrane as mentioned above, to be used in a membrane filtration is obtained by treating a membrane surface with a solution consisting of a water insoluble hydrofilic polymer compound, containing a polar organic solvent. Said treatment is preferably carried out with a solution of a vinyl acetate polymer or a copolymer, containing a polar organic solvent.
A membrane of this type, having been modified in accordance with the invention, is very inconvenient in that the vinyl acetate polymer or copolymer coating, optimally adheres to the surface of the respective membrane, in particular a cellulose acetate membrane, thus causing a longer lifespan of said treated membranes.
It is a further important advantage of the present invention that a thermal curing treatment of membranes, in particular of cellulose acetate membranes, can be omitted when a polymer coating in accordance with the invention is applied.
A further important advantage is in that a membrane need no longer be coated with a coating only consisting of a vinyl acetate copolymer, but that polyvinyl acetate can be used as well, the latter polymer being water insoluble, but soluble in a polar solvent such as a methanol, or mixtures of methanol and water.
In order to obtain the desired porosity membranes need no longer be subjected to an initial thermal curing treatment with the method in accordance with the invention. The manufacture of a membrane so treated will therefore cause a considerable saving of labour expenditures.
The polymers or copolymers to be used for treating the membrane surface in accordance with the invention are in particular a vinylacetate homopolymer having a molecular weight between 2000 and 1 00,000, but a copo lymer containing at least 40% of vinyl acetate and for the rest a monomer, whereby the formed copolymer has naturally to be soluble in polar organic solvents, in particular an alcohol or an alcohol-water mixture such as a methanol or methanol-water-mixture, can be used as well. Suitable monomers for modifying are unsaturated carboxylic acids or esters thereof having the general formula
X -CH = CY-COOZ wherein X represents a hydrogen atom, a lower alkyl- or carboxylic group, Y is a hydrogen atom, a lower alkylgroup or the group
CH2COH, and Z represents a hydrogen atom or a lower alkyl group.
A lower alkyl group is in this case a group containing 1 to 3 carbon atoms.
Dicarboxylic acids can expediently be used such as e.g. maleic-acid, fumaric acid and itaconic acid.
The formation of copolymers by means of copolymerisation is a method known per se, which need not be elucidated. Of course, the carboxylic acids as mentioned hereinbefore, are not only the carboxylic acids proper, but also their anhydrides, since e.g. a maleic acid anhydride is very suitable and can easily be applied. Unsaturated tricarboxylic acids can also be used such as for example aconitic acid and the same holds for unsaturated monocarboxylic acids such as e.g. crotonic acids, acrylic acids and methacryl acids.
The concentration of the polymer compound in the solution ranges from 0,01 to 5,0% by weight and is preferably comprised between 0,5 and 1,5% by weight. When a similar solution is added to the substrate, the concentration of the polymer compound in the substrate is comprised between 0,1 to 100 ppm.
The solution containing the vinyl acetate copolymer or polymer, contains at least 5% of methanol, and although pure methanol (100% methanol) could also be used as a solvent, this is less preferable in view of the hampering influence thereof upon the membranes, in so far as this relates to cellulose acetate membranes.
For the alcohol concentration an upper limit of expediently 75% is preferred and preferably of 45 to 55%, the polar organic solvent being preferably an alcohol and particularly a lower alcohol. More preferably the alcohol is methanol. Instead of methanol, obviously also ethanol, propanol and butanol can be used.
The present invention will now be illustrated by some examples.
Example I
A tubular cellulose acetate membrane is manufactured which is not subjected to a thermal curing treatment as is usual for giving membranes the desired porosity. A 1% solution of a copolymer of vinyl acetate, being modified with 5% crotonic acid is poured into the tubular membrane, the copolymer having a molecular weight of approximately 50 000.
The pH of the polymer solution amounts to 7.
The solution consists of even parts of water and methanol as a polar organic solvent.
This solution is removed after 10 seconds and the membrane rinsed with water (instead of water an aqueous methanol solution can also be used).
After having rinsed the membrane by means of water or an aqueous methanol solution, the membrane is tested with a saline solution containing 5.000 parts per million of sodium chloride at a pressure of 40 ato (4 mPa).
The flux, that is to say the passed quantity of water, amounts to 3,6 cm3/cm2 per hour, whereas the salt retention amounts to 96%.
An identical experiment performed with membranes not having been subjected to a thermal curing treatment, but having been rinsed with water, resulted in a flux of 30cm3/cm2/h and a retention of 3%.
The important advantages of the present invention need no further explanation.
Example II
Example I is repeated, but the inner side of the cellulose acetate membrane is coated with a homopolymer having a molecular weight of approximately 30.000. In this case also a solution consisting of 50% water and of 50% methanol is used.
The results of a reverse osmosis performed at a pressure of 40 ato show a flux of 5,9 cm3/cm2/h and a salt retention of 85%.
Long term experiments have proved that the coating upon the membrane will adhere to said membrane for about one and a half years. During said perior no decrease in the properties of the coating was observed.
Example Ill A cellulose acetate membrane is coated as described in Example I. After the usual treatments, the respective membrane is subjected to a membrane filtration at a pressure of 4 ato, 75 ml of a 1% solution of polymer according to Example I being added to the feed solution.
After a period of three hours, the flux amounted to 1,5 cm3/cm2/h and the retention to 85%. The experiment was continued for three days and a flux of 0,5 was obtained and a retention of 95%. The latter retention remains constant.
Uncoated thermally cured membranes will show a flux of 0,42 and a retention of 85% at a pressure of 4 ato. This unfavourable result clearly shows the advantages of a coating in accordance with the present invention.
Uncoated thermally cured membranes show a flux of approximately 4 and a retention of 96% at a pressure of 40 ato.
From the aforedescribed example it clearly appears that the present invention will cause a considerable flux and a high retention at very low pressures. This results in a considerable economy of energy during membrane filtration and thus to a saving in the overall expenditures.
Example IV
Example I is repeated but instead of cellulose acetate membranes a polyacrylonitrile ("Orlon'' Registered Trade Mark) membrane is used. A treatment with a solution of 1% of a polyvinyl acetate, modified with 5% of crotonic acid (the polyvinyl acetate having a molecular weight of 50.000) in a solvent of 50/50 water/methanol, likewise results in a membrane having a very high retention and a high flux during a long period of time, even at low pressures of 4 ato. The properties obtained at this pressure, are approximately identical to this as described in Example Ill.
For completeness' sake it is observed that the inner side of the pre-formed membrane, contacting liquid to be subjected to a membrane filtration and being coated with a polymer coating, will only at that coated side be in contact with the polar solvent. The other side of said cellulose acetate membrane will not be in contact with said polar organic solvent, such as methanol.
Example V
The surface of a tubular cellulose acetate membrane which will contact medium, to be subjected to a membrane filtration, is treated with a 1% solution of polyvinyl acetate in a mixture of methanol-water (50/50) as described hereinbefore in Example I.
Said membrane is also used for treatment with a 0,1% solution of sodium chloride in water.
At an operating pressure of 20 ato during a period of 1000 hours, the flux will remain 3,2 and the salt retention 95%.
The above mentioned results are also obtained with polysulfon membranes.
Claims (10)
1. A modified membrane for membrane filtration, obtained by treating a membrane surface with a solution of a water insoluble hydrofilic polymer compound, wherein the membrane surface is treated with a solution of a water insoluble hydrofilic polymer compound, containing a polar organic solvent.
2. A modified membrane as claimed in claim 1, wherein the water insoluble hydrofilic polymer compound is a vinyl acetate polymer or copolymer.
3. A membrane as claimed in claim 1 or 2, wherein the membrane consists of a cellulose-ester membrane or of a polyacrylonitrile membrane.
4. A membrane as claimed in claims 1 to 3, wherein the polar organig solvent is an alcohol.
5. A membrane as claimed in claims 1 to 4, wherein the polar organic solvent consists of methanol, ethanol, propanol and/or butanol, and more preferably of methanol.
6. A modified membrane as claimed in claims 1 to 5, wherein the solution contains 5 to 75% of polar organic solvent and the remainder is water, the solution preferably containing 45 to 55% of a polar organic solvent, and more preferably approximately 50% of a polar organic solvent.
7. A modified membrane as claimed in any or more of the preceding claims wherein a non-thermally cured membrane is, directly after its manufacture, treated with the solution containing the polymer compound, while preferably the polymer coating is washed with an aqueous liquid after having applied said coating.
8. A modified membrane as claimed in any or more of the preceding claims wherein solely the surface of the membrane which will contact the fluid to be subjected to a membrane filtration, has contacted the solution, containing the polymer compound.
9. A method for performing a membrane filtration while applying a modified membrane, said membrane being a modified membrane as claimed in any or more of the preceding claims.
10. A method for performing a membrane filtration as claimed in claim 9, wherein a saline solution is desalinated at a pressure of less than 20 ato and preferably at a pressure ranging between 3 and 7 ato.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL7809835A NL7809835A (en) | 1978-09-28 | 1978-09-28 | MODIFIED MEMBRANE FOR MEMBRANE FILTRATION. |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2035133A true GB2035133A (en) | 1980-06-18 |
Family
ID=19831623
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB7933477A Withdrawn GB2035133A (en) | 1978-09-28 | 1979-09-27 | A modified membrane for membrane filtration |
Country Status (6)
Country | Link |
---|---|
JP (1) | JPS5592104A (en) |
BE (1) | BE879067A (en) |
DE (1) | DE2939071A1 (en) |
FR (1) | FR2466265A1 (en) |
GB (1) | GB2035133A (en) |
NL (1) | NL7809835A (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1985001222A1 (en) * | 1983-09-12 | 1985-03-28 | Memtec Limited | Treatment of porous membranes |
WO1985002128A1 (en) * | 1983-11-07 | 1985-05-23 | Memtec Limited | Separating oil emulsions |
EP0221046A2 (en) * | 1985-11-01 | 1987-05-06 | Monsanto Company | Modified polymeric surfaces and process for preparing same |
US4898573A (en) * | 1986-10-29 | 1990-02-06 | Asahi Medical Co., Ltd. | Blood components collector unit |
US4908235A (en) * | 1987-03-05 | 1990-03-13 | Akzo Nv | Process for the production of a bilayer membrane |
EP1254697A2 (en) * | 2001-05-03 | 2002-11-06 | Air Products And Chemicals, Inc. | Composite membranes |
WO2012123446A1 (en) | 2011-03-15 | 2012-09-20 | Glaxo Group Limited | Filter material and face mask against pathogens |
EP2286902A4 (en) * | 2008-03-31 | 2015-09-16 | Toray Industries | Separation membrane, method of producing the same and separation membrane module using the separation membrane |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3043073C2 (en) * | 1980-11-14 | 1984-07-05 | Fresenius AG, 6380 Bad Homburg | Filtration membrane and method for hydrophilization |
JPS5858104A (en) * | 1981-09-30 | 1983-04-06 | Kuraray Co Ltd | Separation membrane for mixed liquid |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE7415145L (en) * | 1973-12-04 | 1975-06-05 | Rhone Poulenc Sa | |
JPS5313431A (en) * | 1976-07-23 | 1978-02-07 | Ricoh Co Ltd | Cleaning roller for fixing roller |
JPS53149874A (en) * | 1977-06-03 | 1978-12-27 | Nippon Shokubai Kagaku Kogyo Co Ltd | Production of compound semipermeable membrane |
-
1978
- 1978-09-28 NL NL7809835A patent/NL7809835A/en not_active Application Discontinuation
-
1979
- 1979-09-27 GB GB7933477A patent/GB2035133A/en not_active Withdrawn
- 1979-09-27 FR FR7924065A patent/FR2466265A1/fr active Pending
- 1979-09-27 DE DE19792939071 patent/DE2939071A1/en not_active Withdrawn
- 1979-09-28 JP JP12424279A patent/JPS5592104A/en active Pending
- 1979-09-28 BE BE0/197372A patent/BE879067A/en unknown
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1985001222A1 (en) * | 1983-09-12 | 1985-03-28 | Memtec Limited | Treatment of porous membranes |
WO1985002128A1 (en) * | 1983-11-07 | 1985-05-23 | Memtec Limited | Separating oil emulsions |
EP0221046A2 (en) * | 1985-11-01 | 1987-05-06 | Monsanto Company | Modified polymeric surfaces and process for preparing same |
EP0221046A3 (en) * | 1985-11-01 | 1988-10-19 | Monsanto Company | Modified polymeric surfaces and process for preparing same |
US4898573A (en) * | 1986-10-29 | 1990-02-06 | Asahi Medical Co., Ltd. | Blood components collector unit |
US4908235A (en) * | 1987-03-05 | 1990-03-13 | Akzo Nv | Process for the production of a bilayer membrane |
EP1254697A2 (en) * | 2001-05-03 | 2002-11-06 | Air Products And Chemicals, Inc. | Composite membranes |
EP1254697A3 (en) * | 2001-05-03 | 2003-10-15 | Air Products And Chemicals, Inc. | Composite membranes |
EP2286902A4 (en) * | 2008-03-31 | 2015-09-16 | Toray Industries | Separation membrane, method of producing the same and separation membrane module using the separation membrane |
US9561478B2 (en) | 2008-03-31 | 2017-02-07 | Toray Industries, Inc. | Separation membrane, method of producing the same and separation membrane module using the separation membrane |
WO2012123446A1 (en) | 2011-03-15 | 2012-09-20 | Glaxo Group Limited | Filter material and face mask against pathogens |
Also Published As
Publication number | Publication date |
---|---|
BE879067A (en) | 1980-03-28 |
DE2939071A1 (en) | 1980-04-03 |
FR2466265A1 (en) | 1981-04-10 |
NL7809835A (en) | 1980-04-01 |
JPS5592104A (en) | 1980-07-12 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |