WO1991009670A1 - Composite diaphragm, process for producing it and its use - Google Patents

Composite diaphragm, process for producing it and its use Download PDF

Info

Publication number
WO1991009670A1
WO1991009670A1 PCT/EP1990/002022 EP9002022W WO9109670A1 WO 1991009670 A1 WO1991009670 A1 WO 1991009670A1 EP 9002022 W EP9002022 W EP 9002022W WO 9109670 A1 WO9109670 A1 WO 9109670A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
gas
membrane
permselective
polymer
Prior art date
Application number
PCT/EP1990/002022
Other languages
German (de)
French (fr)
Inventor
Michael Haubs
Werner Prass
Original Assignee
Hoechst Aktiengesellschaft
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hoechst Aktiengesellschaft filed Critical Hoechst Aktiengesellschaft
Publication of WO1991009670A1 publication Critical patent/WO1991009670A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • 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
    • B01D69/12—Composite membranes; Ultra-thin membranes
    • 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
    • B01D69/12—Composite membranes; Ultra-thin membranes
    • B01D69/1216—Three or more layers
    • 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
    • B01D69/12—Composite membranes; Ultra-thin membranes
    • B01D69/122—Separate manufacturing of ultra-thin membranes
    • 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
    • B01D71/38—Polyalkenylalcohols; Polyalkenylesters; Polyalkenylethers; Polyalkenylaldehydes; Polyalkenylketones; Polyalkenylacetals; Polyalkenylketals
    • 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
    • B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
    • 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
    • B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
    • B01D71/401—Polymers based on the polymerisation of acrylic acid, e.g. polyacrylate
    • B01D71/4011—Polymethylmethacrylate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/308—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising acrylic (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B13/00—Oxygen; Ozone; Oxides or hydroxides in general
    • C01B13/02—Preparation of oxygen
    • C01B13/0229—Purification or separation processes
    • C01B13/0248—Physical processing only
    • C01B13/0251—Physical processing only by making use of membranes
    • C01B13/0255—Physical processing only by making use of membranes characterised by the type of membrane
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2250/00—Layers arrangement
    • B32B2250/03—3 layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2305/00—Condition, form or state of the layers or laminate
    • B32B2305/02—Cellular or porous
    • B32B2305/026—Porous
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/724—Permeability to gases, adsorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2323/00—Polyalkenes
    • B32B2323/10—Polypropylene
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2333/00—Polymers of unsaturated acids or derivatives thereof
    • B32B2333/04—Polymers of esters
    • B32B2333/12—Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2210/00—Purification or separation of specific gases
    • C01B2210/0043—Impurity removed
    • C01B2210/0046—Nitrogen

Definitions

  • the present invention relates to a composite membrane composed of three layers, which is well suited for the separation of gas mixtures and which contains a permselective layer of regularly arranged amphiphilic molecules.
  • a composite membrane for gas separation with a three-layer structure is already known from DE-OS 34 15 624. It contains a supporting membrane layer made of porous polymer (A), a non-porous, gas-permeable intermediate layer (B) made of polyorganosiloxane and a thin layer of a special polymer that has a favorable O 2 / N 2 permeability coefficient ratio (selectivity) (C) .
  • This layer can be obtained by applying a thin film which can be formed on a water surface by the spreading method.
  • Gas permeability of the gas-permeable intermediate layer (B) is generally much greater than that of the permselective layer.
  • the separation selectivity of a membrane is primarily determined by the material of the layer (C). Experience shows, however, that materials with high selectivity have a low permeation coefficient.
  • the use of membranes with such layer thicknesses has become possible after one has learned to virtually plug the pin-holes that always occur in such thin (permselective) layers with silicone rubber (Henis, JMS; Tripodi, MK; Sep. Sei. Technol. 1980 , 15, 1059).
  • the silicone layer can therefore be applied to the membrane as an outer layer. But you can also by Support membrane layer and the permselective layer are enveloped (see. DE-OS 34 15 624).
  • a composite membrane with the generic features of claim 1 has now been found, which is characterized in that the permselective layer (C) is made up of at least one regularly arranged polymer which consists of at least one of the unsaturated monomers
  • R 1 and R 2 are independently CH 3 and C 2 H 5 , and
  • the polymers of the permselective layer (C) are preferably composed of at least 10 monomer units.
  • the layer (A) of the composite membrane represents a porous micro or ultrafilter.
  • the gas-permeable intermediate layer (B) should consist of an amorphous polymer with a high gas permeability. Suitable polymers are, for example. Poly-methylpentene, polysiloxane-polycarbonate block copolymers, poly-trimethylsilylpropine, EPDM rubber or chlorinated polyethylene.
  • the polymers of the permselective layer are insoluble in water but soluble in CH 2 Cl. They form stable monolayers at the water / air interface.
  • the composite membrane according to the invention can be produced by applying a regularly arranged permselective layer made of a specified polymer to a support membrane consisting of a support membrane layer (A) made of porous polymer and a non-porous gas-permeable layer (B) made of an amorphous polymer.
  • a support membrane layer (A) made of porous polymer
  • B non-porous gas-permeable layer
  • the polymer is dissolved in an organic volatile solvent, the solution is spread on a water surface, the resulting monomolecular film is compressed using the Langmuir-Blodgett technique and transferred to the immersed carrier membrane. Mixtures of polymers can also be used. Different polymers can be used in the individual monomolecular films applied one after the other.
  • the support membrane used can be produced by coating a micro or ultrafilter made of polysulfone, polyimide, polyacrylonitrile, polyamide, polyether ketone with the amorphous polymers mentioned.
  • the layer of the amorphous polymer should not be porous and gas permeable.
  • the layer thickness is preferably 15 nm to 500 nm, preferably 30 to 250 nm, in particular 50 to 100 nm.
  • suitable polymers for the gas-permeable intermediate layer (B) are Block copolymers made of polysiloxane and polycarbonate or poly-4-methylpentene. The method of coating is described in Ward, W.J. III, et al: J. Membr. Be. 1976, 1, 99.
  • the method according to the invention it is an advantage of the method according to the invention that several highly ordered and gas-selective layers can be applied in succession to the carrier membrane using the Langmuir-Blodgett technique.
  • the very thin layer can be applied with a homogeneous thickness.
  • the gas to be separated is placed in a container which is closed by the composite membrane.
  • the pressure in the container is greater than outside the container.
  • the permselective layer of amphiphilic molecules preferably faces the overpressure side.
  • a gas can be drawn off on the outside with the lower pressure, in which one component of the two-component mixture is enriched.
  • the process can be adapted to the gas mixture to be separated by selecting a suitable polymer.
  • the process is also suitable for the separation of O 2 / N 2 .
  • a 70 x 70 mm piece of a carrier membrane consisting of a porous carrier membrane made of polypropylene (Celgard 2400), which was coated with a 0.5 ⁇ m thick non-porous layer of polydimethylsiloxane-polycarbonate block copolymer, is made using the method of Langmuir and Blodgett with 12 monolayers of polymethyl -methaerylate coated. For this purpose, a correspondingly large piece is cut out of the carrier membrane and stretched on a 70 x 90 mm frame made of polycarbonate. The membrane to be coated is rinsed off with water under clean room conditions.
  • a monolayer is transferred to the carrier during both the immersion and the immersion process. After the end of the immersion process, the remaining monofilm is sucked off the water surface and, as described above, a monofilm is spread again, compressed to 10 mN / m and 10 further monolayers are transferred to the carrier membrane by immersion and immersion.
  • the transmission ratios are about 40% when immersed and 90-100% when immersed.
  • the oxygen content of the gas mixture sucked in by the vacuum pump is examined and compared with the pressure on the vacuum side.
  • the O 2 content is 28% at 500 mbar, 33% at 250 mbar and about 37% by volume at 5 mbar.

Abstract

A composite diaphragm for gas separation with a three-layer structure, consisting of: A) a supporting diaphragm layer of porous polymer; B) a non-porous, gas-permeable intermediate layer; C) a perm-selective layer of regularly arranged organic molecules with a layer thickness of 3 to 100 nm; where layers (A) and (C) envelop the intermediate layer (B). The perm-selective layer (C) is formed of at least one regularly arranged polymer consisting of at least one of the unsaturated monomers (I) and (II), in which R?1 and R?2 are independently CH3? and C2?H5? and X is H, CH3?, Cl, F and CN.

Description

Beschreibung description
Verbundmembran, Verfahren zu ihrer Herstellung und ihre VerwendungComposite membrane, process for its production and its use
Die vorliegende Erfindung betrifft eine aus drei Schichten aufgebaute Verbundmembran, die sich gut zur Auftrennung von Gasgemischen eignet und die eine permselektive Schicht aus regelmäßig angeordneten amphiphilen Molekülen enthält.The present invention relates to a composite membrane composed of three layers, which is well suited for the separation of gas mixtures and which contains a permselective layer of regularly arranged amphiphilic molecules.
In der Technik stellt sich oftmals die Aufgabe, Gasgemische völlig zu trennen oder eine Komponente des Gasgemisches zumindest anzureichern. Diese Aufgabe wird in zunehmendem Maße mit Hilfe von semipermeablen Membranen erfüllt. Diese Membranen lassen Gase je nach Löslichkeit und Diffusionskoeffizienten mit unterschiedlicher Geschwindigkeit passieren.In technology, there is often the task of completely separating gas mixtures or at least enriching one component of the gas mixture. This task is increasingly being accomplished with the help of semipermeable membranes. These membranes let gases pass at different speeds depending on their solubility and diffusion coefficients.
Aus der DE- OS 34 15 624 ist bereits eine Verbundmembran zur Gastrennung mit einer Dreischichtstruktur bekannt. Sie enthält eine Stützmembranschicht aus porösem Polymerisat (A), eine nicht-poröse, gaspermeable Zwischenschicht (B) aus Polyorganosiloxan und eine dünne Schicht eines speziellen Polymeren, das ein günstiges O2/N2-Permeabilitätskoeffizienten-Verhältnis (Selektivität) aufweist (C). Diese Schicht kann erhalten werden durch Aufbringen eines dünnen Films, der durch das Spreitverfahren auf einer Wasseroberfläche erzeugt werden kann.A composite membrane for gas separation with a three-layer structure is already known from DE-OS 34 15 624. It contains a supporting membrane layer made of porous polymer (A), a non-porous, gas-permeable intermediate layer (B) made of polyorganosiloxane and a thin layer of a special polymer that has a favorable O 2 / N 2 permeability coefficient ratio (selectivity) (C) . This layer can be obtained by applying a thin film which can be formed on a water surface by the spreading method.
Für die technische Anwendbarkeit solcher Gasseparations- Membranen sind sowohl ihre Permeabilität als auch ihre Selektivität von besonderer Bedeutung.Both their permeability and their selectivity are of particular importance for the technical applicability of such gas separation membranes.
Die Permeabilität einer Membran für ein bestimmtes Gas hängt sowohl von der Dicke der aktiven Schicht (= permselektive Schicht), als auch von demThe permeability of a membrane for a certain gas depends both on the thickness of the active layer (= permselective layer), as well as from that
Permeabilitätskoeffizienten für dieses Gas ab. DiePermeability coefficient for this gas. The
Gasdurchlässigkeit (Permeabilität) der gaspermeablen Zwischenschicht (B) ist im allgemeinen wesentlich größer als die der permselektiven Schicht.Gas permeability of the gas-permeable intermediate layer (B) is generally much greater than that of the permselective layer.
Die Trenn-Selektivität einer Membran wird in erster Linie von dem Material der Schicht (C) bestimmt. Die Erfahrung lehrt jedoch, daß Materialien hoher Selektivität einen geringen Permeationskoeffizienten aufweisen.The separation selectivity of a membrane is primarily determined by the material of the layer (C). Experience shows, however, that materials with high selectivity have a low permeation coefficient.
Daher blieben alle Versuche, Polymermaterialien für C zu finden, die sowohl eine hohe Selektivität, als auch einen großen Permeabilitätskoeffizienten aufweisen, bisher erfolglos. Man hat daher nur die Wahl zwischen hochpermeablen und wenig selektiven oder selektiven und wenig permeablen Membranen. Letztere werden heute für technische Anwendungen bevorzugt eingesetzt.Therefore, all attempts to find polymer materials for C that have both a high selectivity and a large permeability coefficient have so far been unsuccessful. One therefore only has the choice between highly permeable and less selective or selective and less permeable membranes. The latter are preferred for technical applications today.
Um zu akzeptablen Permeationsraten zu gelangen, ist man bestrebt, die Dicke der aktiven Schicht (= permselektive Schicht) so dünn wie möglich zu machen. Dabei setzt allerdings das Auftreten von Defekten, sogenannten pin-holes dem Streben nach immer geringeren Schichtdicken Grenzen.In order to achieve acceptable permeation rates, efforts are made to make the thickness of the active layer (= permselective layer) as thin as possible. However, the occurrence of defects, so-called pin-holes, limits the striving for ever smaller layer thicknesses.
So ist es heute möglich, permselektive Schichten mit Schichtdicken von etwa 0,05 bis 0,5 μm (= 50-500 nm) herzustellen. Die Anwendung von Membranen mit solchen Schichtdicken ist möglich geworden, nachdem man gelernt hatte, die in solchen dünnen (permselektiven) Schichten immer auftretenden pin-holes mit Silikongummi quasi zu verstopfen (Henis, J.M.S.; Tripodi, M.K.; Sep. Sei. Technol. 1980, 15, 1059).It is now possible to manufacture permselective layers with layer thicknesses of approximately 0.05 to 0.5 μm (= 50-500 nm). The use of membranes with such layer thicknesses has become possible after one has learned to virtually plug the pin-holes that always occur in such thin (permselective) layers with silicone rubber (Henis, JMS; Tripodi, MK; Sep. Sei. Technol. 1980 , 15, 1059).
Die Silikonschicht kann also als äußere Schicht auf die Membran aufgebracht werden. Sie kann aber auch durch die Stützmembranschicht und die permselektive Schicht eingehüllt werden (vgl. DE-OS 34 15 624).The silicone layer can therefore be applied to the membrane as an outer layer. But you can also by Support membrane layer and the permselective layer are enveloped (see. DE-OS 34 15 624).
Dennoch sind diese bekannten Membranen gerade in Bezug auf ihre Permeabilität noch verbesserungsbedürftig. Es bestand daher die Aufgabe, eine für die Gastrennung geeignete Verbundmembran zu schaffen, die bei guter Selektivität eine erheblich verbesserte Permeabilität aufweist.Nevertheless, these known membranes are in need of improvement, particularly with regard to their permeability. The object was therefore to create a composite membrane which is suitable for gas separation and which, with good selectivity, has a considerably improved permeability.
Es wurde nun eine Verbundmembran mit den Gattungsmerkmalen von Anspruch 1 gefunden, die dadurch gekennzeichet ist, daß die permselektive Schicht (C) aus mindestens einem regelmäßig angeordneten Polymeren aufgebaut ist, das aus mindestens einem der ungesättigten MonomerenA composite membrane with the generic features of claim 1 has now been found, which is characterized in that the permselective layer (C) is made up of at least one regularly arranged polymer which consists of at least one of the unsaturated monomers
CH2=C-C-O-R1 und CH2=CH-O-C-R2
Figure imgf000005_0001
Figure imgf000005_0002
CH 2 = CCOR 1 and CH 2 = CH-OCR 2
Figure imgf000005_0001
Figure imgf000005_0002
besteht, wobeiconsists of
R 1 und R2 unabhängig voneinander CH3 und C2H5, undR 1 and R 2 are independently CH 3 and C 2 H 5 , and
X H, CH3, Cl, F und CNXH, CH 3 , Cl, F and CN
bedeuten.mean.
Vorzugsweise sind die Polymeren der permselektiven Schicht (C) aus mindestens 10 Monomeren-Einheiten aufgebaut. Die Schicht (A) der Verbundmembran stellt ein poröses Mikrooder Ultrafilter dar. Die gaspermeable Zwischenschicht (B) soll aus einem amorphen Polymeren mit einer hohen Gasdurchlässigkeit bestehen. Geeignete Polymere sind z.B.. Poly-methylpenten, Polysiloxan-Polycarbonat- Blockcopolymere, Poly-trimethylsilylpropin, EPDM-Kautschuk oder chloriertes Polyethylen. Die Polymeren der permselektiven Schicht sind unlöslich in Wasser aber löslich in CH2Cl. Sie bilden stabile Monoschichten an der Grenzfläche Wasser/Luft aus.The polymers of the permselective layer (C) are preferably composed of at least 10 monomer units. The layer (A) of the composite membrane represents a porous micro or ultrafilter. The gas-permeable intermediate layer (B) should consist of an amorphous polymer with a high gas permeability. Suitable polymers are, for example. Poly-methylpentene, polysiloxane-polycarbonate block copolymers, poly-trimethylsilylpropine, EPDM rubber or chlorinated polyethylene. The polymers of the permselective layer are insoluble in water but soluble in CH 2 Cl. They form stable monolayers at the water / air interface.
Die erfindungsgemäße Verbundmembran läßt sich dadurch herstellen, daß man auf eine Trägermembran, die aus einer Stützmembranschicht (A) aus porösem Polymerisat und einer nichtporösen gaspermeablen Schicht (B) aus einem amorphen Polymern besteht, eine regelmäßig angeordnete permselektive Schicht aus einem angegebenen Polymeren aufträgt. Bei diesem Verfahren wird das Polymer in einem organischen leicht flüchtigen Lösungsmittel gelöst, die Lösung auf einer Wasseroberfläche gespreitet, der entstehende monomolekulare Film nach der Langmuir-Blodgett-Technik komprimiert und auf die eingetauchte Trägermembran übertragen. Man kann auch Gemische von Polymeren verwenden. In den einzelnen, nacheinander aufgetragenen monomolekularen Filmen können unterschiedliche Polymere eingesetzt werden.The composite membrane according to the invention can be produced by applying a regularly arranged permselective layer made of a specified polymer to a support membrane consisting of a support membrane layer (A) made of porous polymer and a non-porous gas-permeable layer (B) made of an amorphous polymer. In this process, the polymer is dissolved in an organic volatile solvent, the solution is spread on a water surface, the resulting monomolecular film is compressed using the Langmuir-Blodgett technique and transferred to the immersed carrier membrane. Mixtures of polymers can also be used. Different polymers can be used in the individual monomolecular films applied one after the other.
Die eingesetzte Trägermembran läßt sich durch Beschichten eines Mikro- oder Ultrafilters aus Polysulfon, Polyimid Polyacrylnitril, Polyamid, Polyetherketon mit den erwähnten amorphen Polymeren herstellen. Die Schicht des amorphen Polymeren soll nicht porös und gaspermeabel sein. Die Schichtdicke beträgt vorzugsweise 15 nm bis 500 nm, vorzugsweise 30 bis 250 nm, insbesondere 50 bis 100 nm. Als Polymere für die gaspermeable Zwischenschicht (B) eignen sich z.B. Blockcopolymere aus Polysiloxan und Polycarbonat oder Poly-4-methylpenten. Das Verfahren der Beschichtung wird beschrieben in Ward, W.J. III, et al: J. Membr. Sei. 1976, 1, 99.The support membrane used can be produced by coating a micro or ultrafilter made of polysulfone, polyimide, polyacrylonitrile, polyamide, polyether ketone with the amorphous polymers mentioned. The layer of the amorphous polymer should not be porous and gas permeable. The layer thickness is preferably 15 nm to 500 nm, preferably 30 to 250 nm, in particular 50 to 100 nm. Examples of suitable polymers for the gas-permeable intermediate layer (B) are Block copolymers made of polysiloxane and polycarbonate or poly-4-methylpentene. The method of coating is described in Ward, W.J. III, et al: J. Membr. Be. 1976, 1, 99.
Es ist ein Vorteil des erfindungsgemäßen Verfahrens, daß sich nach der Langmuir-Blodgett-Technik mehrere hochgeordnete und gasselektive Schichten nacheinander auf die Trägermembran aufbringen lassen. Außerdem läßt sich die sehr dünne Schicht mit homogener Dicke aufbringen. Um mit Hilfe der erfindungsgemäßen Verbundmembran Gase zu trennen oder zumindest anzureichern, bringt man das aufzutrennende Gas in einem Behälter, der durch die Verbundmembran verschlossen ist. Der Druck im Behälter ist größer als außerhalb des Behälters. Die permselektive Schicht aus amphiphilen Molekülen ist vorzugsweise der Überdruckseite zugewandt. Auf der Außenseite mit dem geringeren Druck läßt sich ein Gas abziehen, in dem eine Komponente des Zwei-Komponenten-Gemisches angereichert ist.It is an advantage of the method according to the invention that several highly ordered and gas-selective layers can be applied in succession to the carrier membrane using the Langmuir-Blodgett technique. In addition, the very thin layer can be applied with a homogeneous thickness. In order to separate or at least enrich gases with the aid of the composite membrane according to the invention, the gas to be separated is placed in a container which is closed by the composite membrane. The pressure in the container is greater than outside the container. The permselective layer of amphiphilic molecules preferably faces the overpressure side. A gas can be drawn off on the outside with the lower pressure, in which one component of the two-component mixture is enriched.
Durch Auswahl eines geeigneten Polymeren läßt sich das Verfahren an das zu trennende Gasgemisch anpassen. Das Verfahren eignet sich auch zur Trennung von O2/N2.The process can be adapted to the gas mixture to be separated by selecting a suitable polymer. The process is also suitable for the separation of O 2 / N 2 .
Die Erfindung wird durch die folgenden Beispiele näher erläutert.The invention is illustrated by the following examples.
Beispiel 1:Example 1:
Gastrennmembran mit Dreischichtaufbau mitGas separation membrane with three-layer structure with
Polymethyl-methaerylat als aktiver TrennschichtPolymethyl methaerylate as an active separating layer
Ein 70 x 70 mm großes Stück einer Trägermembran, bestehend aus einer porösen Trägermembran aus Polypropylen (Celgard 2400), die mit einer 0.5 μm dicken nichtporösen Schicht von Polydimethylsiloxan-Polycarbonat Blockcopolymer beschichtet wurde, wird nach dem Verfahren von Langmuir und Blodgett mit 12 Monolagen Polymethyl-methaerylat beschichtet. Hierzu wird ein entsprechend großes Stück aus der Trägermembran herausgeschnitten und auf einen 70 x 90 mm großen Rahmen aus Polycarbonat gespannt. Die zu beschichtende Membran wird unter Reinraumbedingungen mit Wasser abgespült. Zweihundert Mikroliter einer Lösung von 6 mg Polymethyl-methaerylat in 5 ml Dichlormethan wird bei einer Subphasentemperatur von 30°C auf die Wasseroberfläche einer käuflichen Langmuir-Filmwaage (Filmwaage 2 der Firma MGW Lauda) aufgegeben (gespreitet). Durch Verkleinerung der monofilmbedeckten Wasseroberfläche wird der Schub auf 10 mN/m eingeregelt und bei diesem Wert konstant gehalten. Der Rahmen mit der aufgespannten Membran wird nun senkrecht von oben durch die Wasseroberfläche in die Filmwaage eingetaucht (Eintauchgeschwindigkeit: 20 mm/min) und nach einer kurzen Pause (10 sec.) am unteren Umkehrpunkt wieder herausgenommen (Austauchgeschwindigkeit: 20 mm/min). Sowohl beim Eintauch- als auch beim Austauchvorgang wird dabei eine Monolage auf den Träger übertragen. Nach Beendigung des Austauchvorgangs wird der restliche Monofilm von der Wasseroberfläche abgesaugt und erneut, wie oben beschrieben, ein Monofilm gespreitet, auf 10 mN/m komprimiert und durch Ein- und Austauchen 10 weitere Monolagen auf die Trägermembran übertragen. Die Übertragungsverhältnisse liegen beim Eintauchen bei ca. 40 %, beim Austauchen bei 90 - 100 %.A 70 x 70 mm piece of a carrier membrane, consisting of a porous carrier membrane made of polypropylene (Celgard 2400), which was coated with a 0.5 μm thick non-porous layer of polydimethylsiloxane-polycarbonate block copolymer, is made using the method of Langmuir and Blodgett with 12 monolayers of polymethyl -methaerylate coated. For this purpose, a correspondingly large piece is cut out of the carrier membrane and stretched on a 70 x 90 mm frame made of polycarbonate. The membrane to be coated is rinsed off with water under clean room conditions. Two hundred microliters of a solution of 6 mg of polymethyl methaerylate in 5 ml of dichloromethane is applied (spread) to the water surface of a commercially available Langmuir film scale (film scale 2 from MGW Lauda) at a subphase temperature of 30 ° C. By reducing the monofilm-covered water surface, the thrust is adjusted to 10 mN / m and kept constant at this value. The frame with the stretched membrane is now immersed vertically from above through the water surface into the film scale (immersion speed: 20 mm / min) and after a short pause (10 sec.) At the lower reversal point it is removed again (swapping speed: 20 mm / min). A monolayer is transferred to the carrier during both the immersion and the immersion process. After the end of the immersion process, the remaining monofilm is sucked off the water surface and, as described above, a monofilm is spread again, compressed to 10 mN / m and 10 further monolayers are transferred to the carrier membrane by immersion and immersion. The transmission ratios are about 40% when immersed and 90-100% when immersed.
Die Permeabilität der so hergestellten Membran wird für die Gase Sauerstoff, Stickstoff, Kohlendioxid und Helium gemessen. Dabei werden folgende Ergebnisse erhalten:The permeability of the membrane produced in this way is measured for the gases oxygen, nitrogen, carbon dioxide and helium. The following results are obtained:
Gasfluß bei 25°CGas flow at 25 ° C
(cm3 (STP)/cm2*sec*cm Hg) N2: 3,3x10-5 O2 : 8,9x10-5 (cm 3 (STP) / cm 2 * sec * cm Hg) N 2 : 3.3x10 -5 O 2 : 8.9x10 -5
CO2: 4,6x10-4 He: 4,3x10-4 CO 2 : 4.6x10 -4 He: 4.3x10 -4
Selektivität: O2 /N2 : 2.7 CO2/N2 : 14Selectivity O 2 / N 2 2.7 CO 2 / N 2: 14
He/N2: 13He / N 2: 13
Beispiel 2:Example 2:
Die Membran von Beispiel 1 wird auf der Schicht (C) von Luft angeströmt, während auf der Permeatseite (Schicht A) in Vakuum angelegt wird. Der Sauerstoffgehalt des durch die Vakuumpumpe angesaugten Gasgemischs wird untersucht und dem Druck auf der Vakuumseite gegenübergestellt. Bei 1000 mbar findet sich keine Anreicherung (20 % O2). Bei 500 mbar beträgt der O2-Gehalt 28 %, bei 250 mbar 33 % und bei 5 mbar ca. 37 Volumen-%. Air flows over the membrane of example 1 on layer (C), while vacuum is applied on the permeate side (layer A). The oxygen content of the gas mixture sucked in by the vacuum pump is examined and compared with the pressure on the vacuum side. At 1000 mbar there is no enrichment (20% O 2 ). The O 2 content is 28% at 500 mbar, 33% at 250 mbar and about 37% by volume at 5 mbar.

Claims

PATENTANSPRÜCHE PATENT CLAIMS
1. Verbundmembran zur Gastrennung mit einer Dreischichtstruktur, aufgebaut aus1. Composite membrane for gas separation with a three-layer structure, made up of
A) einer Stützmembranschicht aus porösem Polymerisat,A) a supporting membrane layer made of porous polymer,
B ) einer nichtporösen, gaspermeablen Zwischenschicht ,B) a non-porous, gas-permeable intermediate layer,
C) einer permselektiven Schicht aus regelmäßig angeordneten organischen Molekülen mit einer Schichtdicke von 3 bis 100 nm, wobei die Schichten (A) und (C) die Zwischenschicht (B ) einhüllen, dadurch gekennzeichnet , daß die permselektive Schicht (C) aus mindestens einem regelmäßig angeordneten Polymeren aufgebaut ist , das aus mindestens einem der ungesättigten MonomerenC) a permselective layer of regularly arranged organic molecules with a layer thickness of 3 to 100 nm, the layers (A) and (C) enveloping the intermediate layer (B), characterized in that the permselective layer (C) consists of at least one regularly arranged polymer is built up from at least one of the unsaturated monomers
CH2=C- C- O-R1 und CH2=CH- O- C-R2
Figure imgf000009_0001
Figure imgf000009_0002
CH 2 = C-C-OR 1 and CH 2 = CH-O-CR 2
Figure imgf000009_0001
Figure imgf000009_0002
besteht, wobeiconsists of
R1 und R2 unabhängig voneinander CH3 und C2H5, undR 1 and R 2 are independently CH 3 and C 2 H 5 , and
X H, CH3, Cl, F und CN bedeuten.XH, CH 3 , Cl, F and CN mean.
2. Verbundmembran gemäß Anspruch 1, dadurch gekennzeichnet, daß die Polymeren der permselektiven Schicht (C) aus mindestens 10 Monomeren-Einheiten aufgebaut sind.2. Composite membrane according to claim 1, characterized in that the polymers of the permselective layer (C) are composed of at least 10 monomer units.
3. Verbundmembran gemäß Anspruch 1, dadurch gekennzeichnet, daß die permselektive Schicht (C) aus mindestens zwei übereinander angeordneten monomolekularen Schichten aus Polymeren besteht.3. A composite membrane according to claim 1, characterized in that the permselective layer (C) consists of at least two monomolecular layers of polymers arranged one above the other.
4. Verfahren zur Herstellung einer Verbundmembran gemäß Anspruch 1, wobei man auf eine Trägermembran, die aus einer Stützmembranschicht (A) aus .porösem Polymerisat und einer nicht-porösen, gaspermeablen Schicht (B) aus einem amorphen Polymeren besteht, eine permselektive Schicht (C) aus organischem Material aufträgt, dadurch gekennzeichnet, daß man ein in Wasser nicht lösliches Polymer gemäß Anspruch 1, in einem organischen leicht flüchtigen Lösungsmittel löst, die Lösung auf einer Wasseroberfläche spreitet, den entstehenden Film nach der Langmuir-Blodgett-Technik komprimiert und als monomolekulare permselektive Schicht auf die eingetauchte Trägermembran überträgt.4. A process for producing a composite membrane according to claim 1, wherein a permselective layer (C.) Consists of a support membrane consisting of a support membrane layer (A) made of .porous polymer and a non-porous, gas-permeable layer (B) made of an amorphous polymer ) out applying organic material, characterized in that a water-insoluble polymer according to claim 1 is dissolved in an organic volatile solvent, the solution is spread on a water surface, the resulting film is compressed by the Langmuir-Blodgett technique and as a monomolecular permselective layer transfers to the immersed carrier membrane.
5. Verfahren nach Anspruch 4, dadurch gekennzeichnet, daß man die permselektive monσmolekulare Schicht auf die gaspermeable Schicht (B) der Trägermembran aufbringt.5. The method according to claim 4, characterized in that the permselective monσmolecular layer is applied to the gas-permeable layer (B) of the support membrane.
6. Verfahren zum Trennen eines Gasgemischs in angereicherte Komponenten, wobei man das Gasgemisch in einen Behälter bringt, der durch eine Gastrennmembran mit einer dem Gasgemisch zugewandten permselektiven Außenbeschichtung verschlossen ist, man auf der anderen Seite der Gastrennmembran einen geringeren Druck als im Inneren des Behälters aufrecht hält und eine angereicherte Komponente des Gasgemischs abzieht, dadurch gekennzeichnet, daß man die Verbundmembran gemäß Anspruch 1 als Gastrennmembran einsetzt.6. A process for separating a gas mixture into enriched components, the gas mixture being brought into a container which is closed by a gas separation membrane with a permselective outer coating facing the gas mixture, and a lower pressure is maintained on the other side of the gas separation membrane than in the interior of the container holds and removes an enriched component of the gas mixture, characterized in that the composite membrane according to claim 1 is used as a gas separation membrane.
7. Verfahren nach Anspruch 6, dadurch gekennzeichnet, daß ein aus Stickstoff und Sauerstoff bestehendes Gasgemisch getrennt wird. 7. The method according to claim 6, characterized in that a gas mixture consisting of nitrogen and oxygen is separated.
PCT/EP1990/002022 1989-12-23 1990-11-26 Composite diaphragm, process for producing it and its use WO1991009670A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP3942868.0 1989-12-23
DE3942868A DE3942868A1 (en) 1989-12-23 1989-12-23 COMPOSITE MEMBRANE, METHOD FOR THEIR PRODUCTION AND THEIR USE

Publications (1)

Publication Number Publication Date
WO1991009670A1 true WO1991009670A1 (en) 1991-07-11

Family

ID=6396379

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1990/002022 WO1991009670A1 (en) 1989-12-23 1990-11-26 Composite diaphragm, process for producing it and its use

Country Status (3)

Country Link
DE (1) DE3942868A1 (en)
IE (1) IE904677A1 (en)
WO (1) WO1991009670A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992004109A1 (en) * 1990-08-30 1992-03-19 E.I. Du Pont De Nemours And Company Gas separation membrane with ultrathin layer

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3892665A (en) * 1973-10-15 1975-07-01 Standard Oil Co Membrane method and product
US4155793A (en) * 1977-11-21 1979-05-22 General Electric Company Continuous preparation of ultrathin polymeric membrane laminates
JPS58223411A (en) * 1982-06-21 1983-12-26 Matsushita Electric Ind Co Ltd Composite film for selective permeation of gas
DE3415624A1 (en) * 1983-04-26 1984-10-31 Asahi Glass Co. Ltd., Tokio/Tokyo COMPOSITE MEMBRANE FOR GAS SEPARATION
EP0174918A1 (en) * 1984-08-13 1986-03-19 Monsanto Company Composite gas separation membranes
GB2182581A (en) * 1985-11-05 1987-05-20 British Petroleum Co Plc Fabrication of separation media

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3892665A (en) * 1973-10-15 1975-07-01 Standard Oil Co Membrane method and product
US4155793A (en) * 1977-11-21 1979-05-22 General Electric Company Continuous preparation of ultrathin polymeric membrane laminates
JPS58223411A (en) * 1982-06-21 1983-12-26 Matsushita Electric Ind Co Ltd Composite film for selective permeation of gas
DE3415624A1 (en) * 1983-04-26 1984-10-31 Asahi Glass Co. Ltd., Tokio/Tokyo COMPOSITE MEMBRANE FOR GAS SEPARATION
EP0174918A1 (en) * 1984-08-13 1986-03-19 Monsanto Company Composite gas separation membranes
GB2182581A (en) * 1985-11-05 1987-05-20 British Petroleum Co Plc Fabrication of separation media

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Patent Abstracts of Japan, Band 8, Nr. 71 (C-217)(1508), 3. April 1984; & JP-A-58223411 (MATSUSHITA), & WPIL (Derwent Publ., London), AN = 84-033733 siehe Zusammenfassungen *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992004109A1 (en) * 1990-08-30 1992-03-19 E.I. Du Pont De Nemours And Company Gas separation membrane with ultrathin layer
US5160353A (en) * 1990-08-30 1992-11-03 E. I. Du Pont De Nemours & Company Gas separation membrane with ultrathin layer

Also Published As

Publication number Publication date
DE3942868A1 (en) 1991-06-27
IE904677A1 (en) 1991-07-17

Similar Documents

Publication Publication Date Title
DE2831693C2 (en)
DE3407252C2 (en)
DE2750874C2 (en) Composite membrane for separating gas mixtures, process for their production and their use
DE2850998A1 (en) GAS SEPARATION MEMBRANE AND METHOD OF MANUFACTURING IT
EP0162964B1 (en) Method for the production of an asymmetric membrane
DE2539408B2 (en) MEMBRANES, THE METHOD OF MANUFACTURING IT AND THEIR USE FOR REVERSE OSMOSIS AND ULTRAFILTRATION
EP2296794B1 (en) Polymer membrane
DE1139474B (en) Process for the production of helium
DE4416330A1 (en) Composite membrane and process for its manufacture
DE3525235C1 (en) Process for producing and increasing the selectivity of an integral asymmetrical membrane
DE3415624A1 (en) COMPOSITE MEMBRANE FOR GAS SEPARATION
EP0811420B1 (en) Composite membrane for selective separation of organic substances by pervaporation
DE19600954A1 (en) Composite membrane with increased permeability for selective removal of acidic gas
EP0506701B1 (en) Composite diaphragm, process for producing it and its use
DE10329391A1 (en) Improved gas separation composite membranes made of perfluoropolymers
WO1991009670A1 (en) Composite diaphragm, process for producing it and its use
DE2618981B2 (en) A method of making a porous sheet having fine cylindrical communicating pores
DE4237604C2 (en) Use of a membrane with non-porous hydrophilic separation layer for ultrafiltration
DE3421833A1 (en) Membrane for separating off gases from gas mixtures and process for the production thereof
DE19902517A1 (en) Composite membrane for gas separation comprises a porous supporting membrane, a non-porous, gas-permeable interlayer and a perm-selective layer of polymer based on gamma-alkyl L-glutamate units
DE2129014A1 (en) Semipermeable membrane
DE4006139A1 (en) Three layer composite membrane for gas sepn.
DE3942867A1 (en) Composite membrane for sepn. of gas mixts. - has porous backing, gas-permeable interlayer and perm-selective layer of amphiphilic mols. contg. 1 or 2 7-20C alkyl gps. per polar gp.
EP0597300B1 (en) Polymer membrane containing material specific carriers, process for its production and its utilisation for separating substance compositions
DE10326354A1 (en) Active composite material, for separation by solution-diffusion, e.g. for separating aromatics from aliphatics, comprises anionic copolymer of methacrylate and sulfoalkyl methacrylate ester plus cationic component

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA FI JP KR US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE

NENP Non-entry into the national phase

Ref country code: CA