DE2622805A1 - Membrane filter of cellulose nitrate or acetate - treated by cpd. contg. free hydroxy groups - Google Patents
Membrane filter of cellulose nitrate or acetate - treated by cpd. contg. free hydroxy groupsInfo
- Publication number
- DE2622805A1 DE2622805A1 DE19762622805 DE2622805A DE2622805A1 DE 2622805 A1 DE2622805 A1 DE 2622805A1 DE 19762622805 DE19762622805 DE 19762622805 DE 2622805 A DE2622805 A DE 2622805A DE 2622805 A1 DE2622805 A1 DE 2622805A1
- Authority
- DE
- Germany
- Prior art keywords
- membrane filter
- aftertreatment
- treated
- chemical compound
- cellulose acetate
- 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.)
- Granted
Links
- 239000012528 membrane Substances 0.000 title claims abstract description 44
- 239000000020 Nitrocellulose Substances 0.000 title claims abstract description 19
- FJWGYAHXMCUOOM-QHOUIDNNSA-N [(2s,3r,4s,5r,6r)-2-[(2r,3r,4s,5r,6s)-4,5-dinitrooxy-2-(nitrooxymethyl)-6-[(2r,3r,4s,5r,6s)-4,5,6-trinitrooxy-2-(nitrooxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-3,5-dinitrooxy-6-(nitrooxymethyl)oxan-4-yl] nitrate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O)O[C@H]1[C@@H]([C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@@H](CO[N+]([O-])=O)O1)O[N+]([O-])=O)CO[N+](=O)[O-])[C@@H]1[C@@H](CO[N+]([O-])=O)O[C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O FJWGYAHXMCUOOM-QHOUIDNNSA-N 0.000 title claims abstract description 19
- 229920001220 nitrocellulos Polymers 0.000 title claims abstract description 19
- 229920002301 cellulose acetate Polymers 0.000 title claims abstract description 18
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 title abstract description 5
- 125000002887 hydroxy group Chemical group [H]O* 0.000 title 1
- 238000000034 method Methods 0.000 claims abstract description 16
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000004593 Epoxy Substances 0.000 claims abstract description 5
- 150000008065 acid anhydrides Chemical class 0.000 claims abstract description 5
- NGNBDVOYPDDBFK-UHFFFAOYSA-N 2-[2,4-di(pentan-2-yl)phenoxy]acetyl chloride Chemical compound CCCC(C)C1=CC=C(OCC(Cl)=O)C(C(C)CCC)=C1 NGNBDVOYPDDBFK-UHFFFAOYSA-N 0.000 claims abstract description 3
- 238000012432 intermediate storage Methods 0.000 claims abstract 2
- 150000001875 compounds Chemical class 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- KZMGYPLQYOPHEL-UHFFFAOYSA-N Boron trifluoride etherate Chemical compound FB(F)F.CCOCC KZMGYPLQYOPHEL-UHFFFAOYSA-N 0.000 claims description 4
- WETWJCDKMRHUPV-UHFFFAOYSA-N acetyl chloride Chemical compound CC(Cl)=O WETWJCDKMRHUPV-UHFFFAOYSA-N 0.000 claims description 4
- 239000012346 acetyl chloride Substances 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- IRXBNHGNHKNOJI-UHFFFAOYSA-N butanedioyl dichloride Chemical compound ClC(=O)CCC(Cl)=O IRXBNHGNHKNOJI-UHFFFAOYSA-N 0.000 claims description 3
- 239000003822 epoxy resin Substances 0.000 claims description 3
- 229920000647 polyepoxide Polymers 0.000 claims description 3
- 241000283707 Capra Species 0.000 claims description 2
- 239000003054 catalyst Substances 0.000 claims description 2
- 150000001805 chlorine compounds Chemical class 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- JMANVNJQNLATNU-UHFFFAOYSA-N oxalonitrile Chemical compound N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 claims description 2
- 230000021736 acetylation Effects 0.000 claims 1
- 238000006640 acetylation reaction Methods 0.000 claims 1
- 238000010992 reflux Methods 0.000 claims 1
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 229920002678 cellulose Polymers 0.000 description 4
- 239000001913 cellulose Substances 0.000 description 4
- 230000001954 sterilising effect Effects 0.000 description 4
- 238000004659 sterilization and disinfection Methods 0.000 description 4
- 239000002904 solvent Substances 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- ZASMMGXXWNEACE-UHFFFAOYSA-N acetyl chloride;hexane Chemical compound CC(Cl)=O.CCCCCC ZASMMGXXWNEACE-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 235000013361 beverage Nutrition 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000006196 deacetylation Effects 0.000 description 1
- 238000003381 deacetylation reaction Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000003440 toxic substance Substances 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
- B01D67/0093—Chemical modification
- B01D67/00931—Chemical modification by introduction of specific groups after membrane formation, e.g. by grafting
-
- 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
- B01D71/08—Polysaccharides
- B01D71/12—Cellulose derivatives
- B01D71/14—Esters of organic acids
- B01D71/16—Cellulose acetate
-
- 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
- B01D67/0093—Chemical modification
-
- 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
- B01D71/08—Polysaccharides
- B01D71/12—Cellulose derivatives
- B01D71/20—Esters of inorganic acids, e.g. cellulose nitrate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/30—Cross-linking
Abstract
Description
Verfahren zum Nachbehandeln von Membranfiltern Process for the aftertreatment of membrane filters
Die Erfindung bezeht sich auf ein Verfahren zum Nochbehandeln von Memlranfiltern auf Zellulosenitrat- oder Zelluloseazetat-Basis.The invention relates to a method for further treatment of Memlran filters based on cellulose nitrate or cellulose acetate.
Es ist bekannt, Hembranfilter auf Zellulosenitrat-Basis und Membranfilter auf Zelluloseazetat-Basis durch Denitrieren bzw. Desazetylieren nachzubehandeln, um dadurch erhöhte Beständigkeit gegen organische Lösungsmittel zu erhalten (DT-PS 805 039). Durch diese Nachbehandlung wird das gegen Wasser empfindliche Zellulosenitrat bzw. das Zelluloseazetat mehr oder weniger wieder in Zellulose überführt, wodurch jedoch die Eigenschaften des Membranfilters, insbesondere dessen Festigkeit, erheblich leiden, da mit dieser NAchbehandlung eine erhebliche Versprödung des Filtermaterials eintritt.It is known, cellulose nitrate-based membrane filters and membrane filters post-treatment based on cellulose acetate by denitration or deacetylation, in order to obtain increased resistance to organic solvents (DT-PS 805 039). This post-treatment turns the water-sensitive cellulose nitrate or the cellulose acetate is more or less converted back into cellulose, whereby however, the properties of the membrane filter, in particular its strength, are considerable suffer, as this post-treatment results in considerable embrittlement of the filter material entry.
Demgegenüber liegt der Erfindung die Aufgabe zugrunde, ein Nachbehandlungsverfahren für Membranfilter auf Zellulosenitrat-Basis und Zelluloseazetat-Basis zu schaffen, das in einfacher Weise durchführbar ist und durch das eine wesentliche Erhöhung der Besiändigkeit des Membranfilters gegen Dampf und bzw. oder Alkohol erzielt wird. Insbesondere soll die Beständigkeit gegen WAsserdampf so weitgehend erhöht werden, daß die Membranfilter autoklavierbar werden.In contrast, the invention is based on the object of an aftertreatment method for membrane filters based on cellulose nitrate and cellulose acetate, which can be carried out in a simple manner and through which a substantial increase the resistance of the membrane filter to steam and / or alcohol is achieved. In particular, the resistance to water vapor should be increased to such an extent that that the membrane filters can be autoclaved.
Diese Aufgabe wird gemäß der Erfindung dadurch gelöst, daß das Membranfilter in engem Bad mit einer Lösung einer freie Sauerstoff-Wasserstoff-Gruppen aufweisenden chemischen Verbindung -iachbehandelt wird.This object is achieved according to the invention in that the membrane filter in a close bath with a solution of a free oxygen-hydrogen group chemical compound is post-treated.
Durch die Erfindung wird eine auf Zellulosenitrat-Basis hergestellte Filtermembran, die zunächst zwar dampfbeständig, aber nicht alkoholresistent ist, in eine gegen Dampf und Alkohol resistente Membran umgewandelt. Entsprechend läßt sich eine Filtermembran auf Zelluloseazetat-Basis, die zunächst nicht dampfbeständig, aber einigermaßen alkoholresistew ist, beständig gegen Dampf und Alkohol machen. Für die Nachbehandlung können auch solche chemische Verbindungen mit freien Sauerstoff-WAsserstoff-Gruppen ausgewählt werden, die in Zellulosenitrat bzw. dem Zelluloseazetat Querverbindungen und Vernetzungen der Moleküle hervorrufen. Dadurch werden die so behandelten Filtermembranen nicht nur gegen DAmpf und Alkohol, sondern auch genen die verschiedensten Lösungsmittel, beispielsweise Azeton beständig Im RAhmen der Erfindung kann die für die Nachbehandlung benutzt chemische Verbindung Dizyan sein. Ferner kann die chemische Verbindung ein Säureanhydrid oder ein Gemisch von SÄureanhydriden sein. Es kommt auch als chemische Verbindung für die Nachbehandlung in Betracht, ein Säurechlorid oder ein Gemisch von Säurechloriden. Schließlich kommen auch chemische Verbindungen auf Epoxid-Basis für die Nachbehandlung in Betracht.The invention produces one based on cellulose nitrate Filter membrane, which is initially steam-resistant, but not alcohol-resistant, converted into a membrane resistant to steam and alcohol. Accordingly lets a cellulose acetate-based filter membrane, which is initially not steam-resistant, but is reasonably alcohol-resistant, resistant to steam and alcohol. Chemical compounds with free oxygen-hydrogen groups can also be used for the aftertreatment selected are the cross-links in cellulose nitrate and cellulose acetate and cause crosslinking of the molecules. This will make the so treated filter membranes not only against steam and alcohol, but also genes the most diverse solvents, for example acetone resistant in the framework of the Invention, the chemical compound used for post-treatment can be dicyan. Furthermore, the chemical compound can be an acid anhydride or a mixture of acid anhydrides be. It can also be used as a chemical compound for post-treatment, an acid chloride or a mixture of acid chlorides. Finally, there are also chemicals Compounds based on epoxy for the aftertreatment into consideration.
In einem Ausführungsbeispiel der Erfindung werden Membranfilter auf Nitrozellulose-Basis 15 Minuten lang in einer 2°igen Azetylchlorid-Hexan-Lösung am Rückfluß gekocht. In einem anderen Ausführungsbeispiel können beispielsweise Nitrozellulose-MmbrarIilter eine Stunde lang bei Zimmertemperatur in eine Lösung von 2,-'igem Epoxidharz in Benzin mit Bortrifluorid-Äther-Komplex als Katalysator eingelegt werden.In one embodiment of the invention, membrane filters are on Nitrocellulose base in a 2 ° acetyl chloride-hexane solution for 15 minutes refluxed. In another embodiment, for example Nitrocellulose membrane filters in solution for one hour at room temperature of 2, - 'igem epoxy resin in gasoline with boron trifluoride-ether complex as a catalyst be inserted.
Filtermembranen auf Zelluloseazetat-Basis können beispielsweise durch Behandlung mit Acetylchlorid aufacetyliert und dann gegen Wasserdampf beständig und autoklavierbar gemacht werden.Cellulose acetate-based filter membranes can, for example, through Acetylated treatment with acetyl chloride and then resistant to water vapor and made autoclavable.
Durch Behandlung mit Bernsteinsäurechlorid oder Epoxid lassen sich die Moleküle der Azetatzellulose vernetzen, so daß die so behandelten Filtermembranen dampffest, alkoholfest und beständig gegen Ldsungsmittel, beispielweise Aceton sind.By treatment with succinic acid chloride or epoxy the molecules of the acetate cellulose crosslink, so that the filter membranes treated in this way Steam-proof, alcohol-proof and resistant to solvents, for example Are acetone.
Die Nachbehandlung gemäß der Erfindung kann unmittelbar an den Herstellungsgang der Membranfilter angeschlossen werden.The aftertreatment according to the invention can be applied directly to the production process the membrane filter can be connected.
Es ist jedoch auch möglich, Membranfilter auf Nitrozellulose-Basis bzw. Zelluloseazetat-Basis nach einer Lagerzeit noch im Verfahren gemäß der Erfindung nachzubehandeln.However, it is also possible to use membrane filters based on nitrocellulose or cellulose acetate base after a storage period still in the process according to the invention post-treatment.
Ausführungsbeispiel 1 Nitrozellulose-Membranfilter sind in Methanol löslich und gegen Äthanol instabil. Sie lassen sich jedoch mit Wasserdampf sterilisieren.Embodiment 1 Nitrocellulose membrane filters are in methanol soluble and unstable to ethanol. However, they can be sterilized with steam.
Solche fertigen Nitrozellulose-Membranfiler werden 15 Minuten lang in einer 2%igen Azethylchlorid-Hexan-Lösung am Rückfluß gekocht, wodurch die Nitrozellulose zumindest teilweise verestert wird.Such finished nitrocellulose membrane filters are 15 minutes long refluxed in a 2% acetyl chloride-hexane solution, thereby reducing the nitrocellulose is at least partially esterified.
Die so optimierten Membranfilter sind unlöslich und beständig gegen Methanol und Äthanol und zudem bei Überdruck (1210C) im Autoklaven mit Dampf sterilisierbar.The membrane filters optimized in this way are insoluble and resistant to Methanol and ethanol and can also be sterilized with steam at overpressure (1210C) in the autoclave.
Ausführunsbeisoiel a IJitrozellulose-lWEmbranfilter herkömmlicher Art werden in eine ziege Lösung von Epoxidharz in Benzin mit Zugabe von Bortrifluorid-Ather-Komplex (Bortrifluorid-Ätherat) eine Stunde: lang bei Zimertemperatur eingelegt. Bei dieser Nachbehandlung werden die Nitrozellulose-Membranfilter veräthert.Execution for example of a nitrocellulose-type membrane filter, conventional Kind be in a goat solution of epoxy resin in gasoline with the addition of Boron trifluoride-ether complex (Boron trifluoride etherate) one hour: put in at room temperature. At this After treatment, the nitrocellulose membrane filters are etherified.
Die so verätherten Membranfilter sind gegen Alkohol unlöslich und beständig und im Autoklaven mit Dampf sterilisierbar.The membrane filters etherified in this way are insoluble in alcohol and resistant and sterilizable in the autoclave with steam.
Azetatzellulose-Membranfilter sind zwar von sich aus einigermaßen stabil gegen Alkohol, aber nicht beständig gegen Wasserdampf. Durch Behandlung mit Acetylchlorid läßt sich das Zelluloseazetat dieser Membranfilter so weit aufacetylieren, : da auch solche Zelluloseazetat-Meinbranfilter autoklavierbar werden. Eine andere ilöglichkeit, um Membranfilter auf Zelluloseazetat-Basis beständig gegen Wasserdampf zu machen, besteht in der Behandlung mit Bernsteinsäurechlorid oder Epoxid. Bei solcher Behandlung werden die Zelluloseazetat-Moleküle vernetzt. Derart nachbehandelte Membranfilter auf Zelluloseazetat-Basis haben sich als beständig gegen Lösungsmittel, inbesondere Aceton, herausgestellt.Acetate cellulose membrane filters are by themselves to some extent stable to alcohol, but not resistant to water vapor. By treating with Acetyl chloride, the cellulose acetate in these membrane filters can be acetylated to such an extent that : because such cellulose acetate Meinbran filters can also be autoclaved. Another possibility of making membrane filters based on cellulose acetate resistant to water vapor to make it consists in treatment with succinic acid chloride or epoxy. at such treatment will crosslink the cellulose acetate molecules. Post-treated in this way Cellulose acetate-based membrane filters have proven to be resistant to solvents, in particular acetone.
Durch die Erfindung wird erreicht, daß jegliche Arten und Typen von Membranfiltern auf Nitrozellulose-Basis bzw.The invention achieves that any types and types of Membrane filters based on nitrocellulose or
Azetatzellulose-Basis gegen Alkohol beständig gemacht werden können und im DAmpfautoklaven behandelbar gemacht werden können. Damit können Membranfilter für die verschiedensten Anwendungst ebiete ohne schwierige SpeziLbehandlung benutzbar gemacht werden, und zwar in jeglichem Typ und jeglicher Porengröße.Acetate cellulose base can be made resistant to alcohol and can be made treatable in the steam autoclave. This allows membrane filters Can be used for a wide range of applications without any difficult special treatment can be made in any type and any pore size.
Durch die Erfindung kann Dampfsterilisation der Membranfilter bei 120° bis 130°C durchgef@hrt werden. Au@er der Mäglichkeit der Dampfsterilisation der Filtermembranen in Autoklaven bietet sich dadurch auch die Möglichkeit einer eventuell zwischenzeitigen Sterilisation des in die Filterpresse eingesetzten Membranfilters.With the invention, steam sterilization of the membrane filter can be achieved 120 ° to 130 ° C can be carried out. Except for the possibility of steam sterilization the filter membrane in autoclaves offers the possibility of a possibly interim sterilization of the membrane filter inserted in the filter press.
Diese, durch die Erfindung eröffneten iföglichkeiten sind von besonderer ichtigkeit far die Lebensmittelaufbereitung, beispielsweise Getränkeaufbereitung, da die durch die Erfindung entfallende, bisher notwendige Kaltsterilisation der Membranfilter nicht nur teuer ist, sondern auch mit hochgiftigen Stoffen durchgeführt werden mußte.These possibilities opened up by the invention are special ightness for food preparation, e.g. beverage preparation, since the previously necessary cold sterilization of the, which is omitted by the invention Membrane filter is not only expensive, but also carried out with highly toxic substances had to become.
- Patentansprüche -- patent claims -
Claims (11)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2622805A DE2622805C2 (en) | 1976-05-21 | 1976-05-21 | Process for the aftertreatment of membrane filters |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2622805A DE2622805C2 (en) | 1976-05-21 | 1976-05-21 | Process for the aftertreatment of membrane filters |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| DE2622805A1 true DE2622805A1 (en) | 1977-12-01 |
| DE2622805C2 DE2622805C2 (en) | 1982-11-11 |
Family
ID=5978676
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE2622805A Expired DE2622805C2 (en) | 1976-05-21 | 1976-05-21 | Process for the aftertreatment of membrane filters |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE2622805C2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0050864A1 (en) * | 1980-10-27 | 1982-05-05 | Amf Incorporated | A hydrophilic cationic charge modified microporous membrane, a process for producing it and its use |
| US4707266A (en) * | 1982-02-05 | 1987-11-17 | Pall Corporation | Polyamide membrane with controlled surface properties |
| US4966699A (en) * | 1988-05-25 | 1990-10-30 | Terumo Kabushiki Kaisha | Hollow fiber membrane fluid processor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE805039C (en) * | 1949-11-01 | 1951-05-07 | Membranfiltergesellschaft Sart | Process for the production of membrane filters |
| DE1154623B (en) * | 1958-04-09 | 1963-09-19 | American Mach & Foundry | Process for the production of selective membranes |
| DE1930506A1 (en) * | 1968-03-18 | 1970-01-02 | Lubrizol Corp | N-(3-hydroxyalkyl)-acrylamides, R1-CH(OH)-CR2R3-CR4R5-NH-CO-CR6=CH2 form (cross-linked) (co)polymers. Polymers are permeable to water vapour and gases and |
| DE2441311A1 (en) * | 1974-08-29 | 1976-03-11 | Hese Niels | Membrane for purifying indl. effluents - by casting membrane from polymer soln. and treating with metal ion soln. |
-
1976
- 1976-05-21 DE DE2622805A patent/DE2622805C2/en not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE805039C (en) * | 1949-11-01 | 1951-05-07 | Membranfiltergesellschaft Sart | Process for the production of membrane filters |
| DE1154623B (en) * | 1958-04-09 | 1963-09-19 | American Mach & Foundry | Process for the production of selective membranes |
| DE1930506A1 (en) * | 1968-03-18 | 1970-01-02 | Lubrizol Corp | N-(3-hydroxyalkyl)-acrylamides, R1-CH(OH)-CR2R3-CR4R5-NH-CO-CR6=CH2 form (cross-linked) (co)polymers. Polymers are permeable to water vapour and gases and |
| DE2441311A1 (en) * | 1974-08-29 | 1976-03-11 | Hese Niels | Membrane for purifying indl. effluents - by casting membrane from polymer soln. and treating with metal ion soln. |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0050864A1 (en) * | 1980-10-27 | 1982-05-05 | Amf Incorporated | A hydrophilic cationic charge modified microporous membrane, a process for producing it and its use |
| US4707266A (en) * | 1982-02-05 | 1987-11-17 | Pall Corporation | Polyamide membrane with controlled surface properties |
| US4966699A (en) * | 1988-05-25 | 1990-10-30 | Terumo Kabushiki Kaisha | Hollow fiber membrane fluid processor |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2622805C2 (en) | 1982-11-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| OD | Request for examination | ||
| D2 | Grant after examination | ||
| 8339 | Ceased/non-payment of the annual fee |