WO2005082500A2 - Membrane de filtration a pores ouverts et procede de production de ladite membrane - Google Patents

Membrane de filtration a pores ouverts et procede de production de ladite membrane Download PDF

Info

Publication number
WO2005082500A2
WO2005082500A2 PCT/DE2005/000256 DE2005000256W WO2005082500A2 WO 2005082500 A2 WO2005082500 A2 WO 2005082500A2 DE 2005000256 W DE2005000256 W DE 2005000256W WO 2005082500 A2 WO2005082500 A2 WO 2005082500A2
Authority
WO
WIPO (PCT)
Prior art keywords
polymer
mixture
peg
casting solution
water
Prior art date
Application number
PCT/DE2005/000256
Other languages
German (de)
English (en)
Other versions
WO2005082500A3 (fr
Inventor
Christoph Kullmann
Carsten Blicke
Klaus Vossenkaul
Stefan Schäfer
Original Assignee
Koch Membrane Systems Gmbh
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 Koch Membrane Systems Gmbh filed Critical Koch Membrane Systems Gmbh
Publication of WO2005082500A2 publication Critical patent/WO2005082500A2/fr
Publication of WO2005082500A3 publication Critical patent/WO2005082500A3/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0002—Organic membrane manufacture
    • B01D67/0009—Organic membrane manufacture by phase separation, sol-gel transition, evaporation or solvent quenching
    • B01D67/0011—Casting solutions therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/66—Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
    • B01D71/68—Polysulfones; Polyethersulfones
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2323/00—Details relating to membrane preparation
    • B01D2323/12—Specific ratios of components used
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2323/00—Details relating to membrane preparation
    • B01D2323/15—Use of additives
    • B01D2323/18—Pore-control agents or pore formers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2323/00—Details relating to membrane preparation
    • B01D2323/219—Specific solvent system
    • B01D2323/22—Specific non-solvents or non-solvent system

Definitions

  • the invention relates to an open-pore filtration membrane and a method for its production based on a polymer or a polymer mixture, in which a casting solution consisting of a polyether or an aliphatic, water-soluble compound with at least two ether groups or a mixture of these substances and the therein dissolved polymer or the polymer mixture, and optionally an aprotic polar solvent and / or a pore former and / or a quenching agent, is produced with stirring, formed into a film and precipitated by phase inversion in a precipitation process, in particular by immersion in a precipitation bath ,
  • membranes were mainly produced using sometimes complicated and dangerous processes with toxic, highly caustic, flammable or even explosive chemicals as solvents or precipitants. With a relatively large layer thickness, these products had only a low permeability and could therefore only be used economically with a few exceptions.
  • the membranes and the associated separation processes were widely used for the first time after it was possible to produce membranes with high asymmetry (Adv. Chem. Ser. 38, 1 17 (1962)).
  • phase inversion which is crucial for such membrane production, was initially only developed for cellulose acetate, but later also on hydrophobic polymers, e.g. B. polysulfone, since the membranes made of cellulose acetate have some disadvantages, e.g. B. a high sensitivity to temperatures above 35 degrees Celsius and a relatively easy attack by microorganisms.
  • membranes made of cellulose acetate are subject to hydrolysis in an acidic or basic environment.
  • the phase inversion represents an exchange process in which the polymer or casting solution is placed on a support that is as flat as possible, e.g. B. a glass plate, but also a metal drum or a fleece is spread out as a liquid layer with a defined layer thickness.
  • a support that is as flat as possible, e.g. B. a glass plate, but also a metal drum or a fleece is spread out as a liquid layer with a defined layer thickness.
  • the formed casting solution that is, the solution film in a precipitation bath, usually a water bath
  • the solvent diffuses out of the solution and is exchanged for water diffusing into the forming pores;
  • the solubility limit is reached, the water-insoluble membrane-forming polymer of the casting solution solidifies, forming a film with an open-pore surface structure that appears white due to the foamy structure.
  • the immersion of the still liquid casting solution in the precipitation bath can also be replaced by vaporization of the formed casting solution with water vapor or the like which triggers the precipitation process
  • Phase inversion membranes perform their duties successfully in all possible areas, from blood washing in diabetes to wastewater treatment in sewage treatment plants to the production of ultrapure water in the electronics industry. In addition, they are used even on a large scale as a carrier material for extremely thin coatings with release properties if these layers are no longer manageable even because of their layer thickness of sometimes less than 100 nm. Such so-called composite membranes find their industrial application, among other things, in water desalination and gas separation.
  • phase inversion membranes are by definition used as reverse osmosis membranes for water desalination, as ultrafiltratlons membranes for separation of molecules up to a molecular weight of 100,000 g / mol, and referred to as microfiltration membranes with pore sizes down to the ⁇ m range for the separation of bacteria and viruses.
  • phase inversion membranes briefly described above has been preserved to this day, even if due to variations in the composition of the casting solution, e.g. B. combinations of different solvents, use of additives and non-solvents such. B. as a pore former, or changing the membrane thickness or varying the production conditions has been attempted in many ways and will influence the membrane structure and find manufacturing alternatives.
  • a membrane is referred to as an asymmetrical membrane if the pore size of the membrane is viewed across the cross section from the side usually facing the medium to be separated (in the case of supported membranes the side facing away from the support) to the opposite side (in the case of supported membranes the side facing the support) ) increases.
  • caverns represent potential weak points, particularly for membranes that are exposed to high pressure or abrasive media during operation, which considerably reduce the life expectancy of the membrane.
  • membranes used in water purification have to withstand cyclical backwashing due to the deposition of impurities and the formation of a so-called bacterial lawn on the membrane surface. The membrane is flushed with clear water from the back of the membrane.
  • phase inversion membranes currently described come from casting solutions with the composition: x% polymer (s), y% polar (s) aprotic solvent (s), optionally z% non-solvent, optionally a% additives.
  • polysulfones polysulfone (PSU), polyethersulfone (PESU), polyphenylsulfone (PPSU)), polyetherimide (PEI), polyvinylidene fluoride (PVDF), polyamideimide and polyacrylonitrile.
  • PSU polysulfone
  • PESU polyethersulfone
  • PPSU polyphenylsulfone
  • PEI polyetherimide
  • PVDF polyvinylidene fluoride
  • polyamideimide polyacrylonitrile.
  • Polysulfones represent the highest proportion in membrane technology.
  • polar aprotic and water-soluble solvents are dimethylformamide (DMF), dimethylacetamide (DMA), dioxane, N-methylpyrrolidone (NMP), hexamethylphosphoric acid triamide (HMPT), dimethyl sulfoxide (DMSO) or formamide.
  • DMF dimethylformamide
  • DMA dimethylacetamide
  • NMP N-methylpyrrolidone
  • HMPT hexamethylphosphoric acid triamide
  • DMSO dimethyl sulfoxide
  • Triethyl phosphate is also called, but it is a special case because it disintegrates in an aqueous environment, ie it is not actually water-soluble.
  • Common non-solvents are water, glycerin and polyethylene glycol (PEG). Glycerin and PEG are often used to increase the viscosity of a casting solution. The use of larger amounts of PEG also improves the sponge structure of the membranes.
  • LiCI lithium chloride
  • PVAl polyvinyl alcohol
  • PVP polyvinyl pyrrolidone
  • Ti0 2 or Zr0 2 Ti0 2 or Zr0 2 .
  • PVP is used, for example, to provide the generally very hydrophobic membranes with a hydrophilic surface. The built in the membrane structure The polymer is said to prevent the attachment of organic molecules to the membrane surface and the resulting blocking.
  • cloud point is the mixing ratio at which the previously clear solution begins to cloud.
  • a disadvantage of known processes for the production of filtration membranes is the often considerable toxicity of the substances and above all that of the above-described aprotic solvents and the associated very expensive effort to recover them in order to separate them or to recycle them into the process. Since the processes described are mostly used in large-scale plants in the chemical industry, there is also a not insignificant potential hazard for the environment and the population.
  • the object of the invention is to propose a method which makes it possible, as far as possible, to largely prevent the chemical loads which occur in known manufacturing processes for membranes, to improve the membrane structure with regard to the undesired caverns, in this way to increase the pressure resistance and at the same time the costs of the manufacturing process to reduce.
  • the object is achieved by the invention in that a method is specified in which the casting solution is at least 83%, based on its total weight, on the one hand of the polymer or the polymer mixture and on the other hand of a polyether or an aliphatic, water-soluble compound with at least two Ether groups or a mixture of these substances.
  • the membranes according to this invention as well as the conventional phase inversion membranes are produced from a casting solution within the process.
  • none of the known aprotic, polar solvents have to be used, but rather aliphatic polyethers such as that PEG previously known as a non-solvent or additive.
  • a membrane with an almost symmetrical cross section is created, for example, by dissolving PESU in PEG.
  • the precipitation process itself is comparable to that of conventional membranes.
  • the blends behave very similar to the corresponding solutions to additives and other non-solvents, such as water.
  • the pore sizes can be adjusted by varying different PEGs.
  • classic solvents such as DMA or NMP, added to the casting solutions as an additive in individual cases, take on the usual function of non-solvents in traditionally manufactured membranes.
  • the sensitivity to water of a PE-SU / PEG blend which is normally relatively moisture-tolerant, can be extremely increased by adding NMP.
  • the effect of a certain amount of PEG in the casting solution for changing the membrane structure has long been known, as Holzki states in examples in US Pat. No. 5,620,790 (1997).
  • Kraus US Pat. No.
  • 5,076,935 also describes, in an example of an easily water-wettable membrane made from a PESU / phenoxy blend, a casting solution with a PEG 400 content of 69%, but with 18% dimethylformamide (DMF) as the solvent. be used.
  • DMF dimethylformamide
  • the membranes produced by means of the process according to the invention cover the entire membrane spectrum without further process steps - from narrow-pored ultrafiltration membranes to open microfiltration membranes.
  • the previously known and described polar, aprotic solvents can be wholly or predominantly by substances previously known as non-solvents, in particular by non-toxic polyethers or mixtures be replaced from it. It is surprising that, despite the small or completely missing proportion of customary solvents, a membrane can be produced at all by means of the method according to the invention.
  • membranes can be produced within the specified range, which compared to known membranes are not only free from any disadvantages with regard to structure and properties such as flow rate and pressure stability, but may even be superior to them.
  • the membrane itself produced by the method according to the invention should also be part of the invention, since a wide range of different membrane types can be generated by suitable choice of material, control of the phase inversion by temperature and pressure conditions and other casting conditions.
  • the respective physical form of the finished membrane can thus be adapted to the respective intended use and is in principle only subject to the associated restrictions. It can therefore be all bodies with large surfaces in relation to the volume. B. tubes in the broader sense or flat membranes.
  • the casting solution required for the manufacture of the membrane for the production of the membrane is at least 85%, 90%, 95% and finally completely, on the one hand from the polymer or the polymer mixture and on the other hand from a polyether or an aliphatic , water-soluble compound with at least two ether groups or a mixture of these substances.
  • the general advantage of each of these configurations according to the invention is the further reduced chemical load with conventional solvents and other additives.
  • the membrane which can be produced according to the proposed method is given an excellently uniform structure, shown in FIG. 3, in particular when using the casting solution containing at least 85% of the substances mentioned above, and permits above-average flow rates of about 1200 liters per square meter and hour compared to those to be expected 50 lm- 2 h "1 !
  • the membrane shown in FIGS. 5 and 6, which has pores with pore sizes in the range from a few tens to a few hundred nanometers, can be obtained in accordance with a process configuration, that is to say when using the casting solution containing at least 95% of the substances mentioned above. If - as suggested - only the specified substances are used for the casting solution, a membrane can be produced, as shown in FIG. 2.
  • the outstanding uniformity in the distribution of the almost equally large pores with the simultaneous absence of any caverns or the like has hitherto been almost unknown for membranes and allows them to be used in completely new filtration processes.
  • an embodiment of the method according to the invention also provides that the solvent consists of triethylene glycol or tetraethylene glycol or PEG or PPG or PEG ether or PPG ether or PEG diether or PPG diether or ethylene carbonate or propylene carbonate or a mixture of at least two of these compounds , since the named substances can basically be used in the stated manner as solvents for polymers.
  • the polyether be a polyethylene glycol with a molar mass between 200 and 1500 or contain it in a mixture.
  • PEG 200, PEG 400 and PEG 600 are particularly preferred.
  • PEG 400 is a colorless and odorless liquid at room temperature that solidifies to a soft wax at around five degrees Celsius.
  • PEG 400 is soluble in water in all mixing ratios. It is a safe substance and, as a previously known pore former, is extremely compatible with the polymer, so that, like PEG 200 and PEG 600, it can be present in the casting liquid together with the polymer in an amount of over 83 percent by weight.
  • membranes according to this invention have exceptional pressure stability, practically no defects and are mechanically stable to almost complete abrasive destruction without loss of separation performance.
  • the invention is explained below on the basis of preferred exemplary embodiments, the basic method steps or chemical compositions necessary for its production and with reference to the attached figures, which show the following:
  • Fig. 1 is a SEM image of a cross section of a flat membrane, produced according to the prior art
  • a membrane is shown, which according to the prior art, i. H. using an amount of polar aprotic solvents significantly above the claim of this invention. Particularly striking are the relatively voluminous, finger-like structures, which occupy about two thirds of the membrane cross section in the SEM section.
  • Example 2 A membrane according to FIG. 2 is formed if PESU is mixed with PEG 200 and PEG 600 in the ratio 16/30/54 and stirred at room temperature for three days until the polymer has completely dissolved with a dissolver.
  • the highly viscous and homogeneous blend both as a flat membrane and as a hollow thread, forms the structure shown when precipitated in water.
  • the membrane in which the starting casting solution contains no polar aprotic solvents has a structure that is almost to completely symmetrical over the entire cross-section without cavities.
  • the membrane has a very high internal resistance and only achieves an uneconomically low permeability.
  • the membrane according to the invention has an exceptionally high surface porosity, which is essential for the membrane performance and more than makes up for the loss due to the internal resistance.
  • a membrane with considerably coarser pores according to FIG. 3 is formed if PESU is mixed with PEG 200 and NMP in a ratio of 12.5 / 72.5 / 15 and stirred until the polymer has completely dissolved, which takes about 2 days.
  • the blend is permanently stable up to approx. 28 ° C, but begins to disintegrate at higher temperatures. It is remarkable that the addition of NMP often leads to the formation of unusually shaped caverns, as shown in FIG. 4.
  • a membrane similar to Example 3 is obtained if the blend of PESU, tetraethylene glycol and PEG 600 is added with the addition of water according to the composition 15.3 / 14.4 / 66 / 4.3 (FIG. 5). 6 shows the surface of this membrane.
  • PESU is mixed with triethylene glycol dimethyl ether in a ratio of 16/84 and stirred until the polymer has dissolved. What is remarkable here is the already mentioned clear difference between a classic solution and a blend obtained in this way. While in a solution the polymer is dissolved the quicker and better the smaller its amount, a blend according to this invention requires a minimum amount of polymer in order to be able to form a homogeneous phase at all.
  • the present mixture forms a milky emulsion at room temperature, which separates into two phases, a clear, viscous, polymer-rich and an overlying cloudy, aqueous and low-polymer. At temperatures below 17 ° C, both phases are clear and, when mixed together, form a permanently stable blend.
  • PESU mixed with triethylene glycol dimethyl ether in a ratio of 23.6 / 76.4, forms a permanently stable blend at room temperature.
  • the resulting membranes are very similar to those that would have resulted from a PVDF solution (Fig. 7).

Abstract

L'invention concerne une membrane de filtration à pores ouverts ainsi qu'un procédé de production de ladite membrane à partir d'un polymère ou d'un mélange de polymères. Selon ledit procédé, une solution coulable, composée d'un polyéther ou d'un composé aliphatique soluble dans l'eau présentant au moins deux groupes éther ou d'un mélange de ces substances et du polymère dissous dans ce dernier ou du mélange de polymères ainsi qu'éventuellement d'un solvant polaire aprotique et/ou d'un agent porogène et/ou d'un agent gonflant, est transformée en un film puis précipitée par inversion de phase au cours d'un processus de précipitation, en particulier par immersion dans un bain de précipitation. L'objectif de l'invention est d'améliorer le procédé susmentionné. A cet effet, le polymère ou mélange de polymères, d'une part, et le polyéther ou composé aliphatique soluble dans l'eau présentant au moins deux groupes éther ou le mélange de ces substances, d'autre part, constituent au moins 83 % de la solution coulable, par rapport à son poids total.
PCT/DE2005/000256 2004-02-26 2005-02-15 Membrane de filtration a pores ouverts et procede de production de ladite membrane WO2005082500A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102004009877A DE102004009877B4 (de) 2004-02-26 2004-02-26 Offenporige Filtrationsmembran und Verfahren zu deren Herstellung
DE102004009877.8 2004-02-26

Publications (2)

Publication Number Publication Date
WO2005082500A2 true WO2005082500A2 (fr) 2005-09-09
WO2005082500A3 WO2005082500A3 (fr) 2006-03-02

Family

ID=34894897

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE2005/000256 WO2005082500A2 (fr) 2004-02-26 2005-02-15 Membrane de filtration a pores ouverts et procede de production de ladite membrane

Country Status (2)

Country Link
DE (1) DE102004009877B4 (fr)
WO (1) WO2005082500A2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014096071A1 (fr) * 2012-12-19 2014-06-26 Solvay Sa Procédé de fabrication de membrane polymère sulfone

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5076935A (en) * 1990-05-31 1991-12-31 Gelman Sciences, Inc. Filtration membranes made from polyethersulfone/phenoxy resin blend
US5108607A (en) * 1987-05-20 1992-04-28 Gelman Sciences, Inc. Filtration membranes and method of making the same
US6056903A (en) * 1999-02-08 2000-05-02 Osmonics, Inc. Preparation of polyethersulfone membranes
US20010003123A1 (en) * 1997-09-18 2001-06-07 Meluch Timothy B. Melt-spun polysulfone semipermeable membranes and methods for making the same
US20030192826A1 (en) * 2002-04-12 2003-10-16 I-Fan Wang Hydrophobic membrane Materials for filter venting applications

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5108607A (en) * 1987-05-20 1992-04-28 Gelman Sciences, Inc. Filtration membranes and method of making the same
US5076935A (en) * 1990-05-31 1991-12-31 Gelman Sciences, Inc. Filtration membranes made from polyethersulfone/phenoxy resin blend
US20010003123A1 (en) * 1997-09-18 2001-06-07 Meluch Timothy B. Melt-spun polysulfone semipermeable membranes and methods for making the same
US6056903A (en) * 1999-02-08 2000-05-02 Osmonics, Inc. Preparation of polyethersulfone membranes
US20030192826A1 (en) * 2002-04-12 2003-10-16 I-Fan Wang Hydrophobic membrane Materials for filter venting applications

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014096071A1 (fr) * 2012-12-19 2014-06-26 Solvay Sa Procédé de fabrication de membrane polymère sulfone
CN104918985A (zh) * 2012-12-19 2015-09-16 索尔维公司 用于制造砜聚合物膜的方法
CN104918985B (zh) * 2012-12-19 2019-08-09 索尔维公司 用于制造砜聚合物膜的方法

Also Published As

Publication number Publication date
WO2005082500A3 (fr) 2006-03-02
DE102004009877A1 (de) 2005-10-06
DE102004009877B4 (de) 2006-05-24

Similar Documents

Publication Publication Date Title
DE2935097C2 (fr)
EP2695669B1 (fr) Membrane avec couche isoporeuse de séparation et procédé de fabrication d'une membrane
EP2695668B1 (fr) Procédé de fabrication d'une membrane de filtration thermosensible et membrane de filtration thermosensible
EP2922620B1 (fr) Procédé pour la production d'une membrane polymère à fil creux intégrale asymétrique à partir d'un copolymère à blocs amphiphile, membrane à fil creux obtenue et son utilisation
DE2917357C2 (fr)
DE19934735C2 (de) Polyamid-Umkehrosmosemembran
DE2920762C2 (de) Mikroporöse Polyvinylalkoholmembran
DE2829630B2 (de) Semipermeable Membran und Verfahren zu ihrer Herstellung
DE3125980A1 (de) "polymethylmethacrylatmembran"
DE3342823C2 (fr)
DE2615954A1 (de) Polyvinylalkohol-membran und verfahren zu ihrer herstellung
DE2321460B2 (de) Hohlfasern aus Acrylnitrilpolymeren und Verfahren zu ihrer Herstellung
DE2816088A1 (de) Ionenabweisende membran, verfahren zu deren herstellung und verwendung derselben
DE2838665A1 (de) Aethylen/vinylalkohol-copolymermembran und verfahren zu ihrer herstellung
DE2621519C3 (de) Verfahren zur Herstellung von asymmetrischen permselektiven Zellulosetriacetatmembranen mit Skinschicht
DE3835612A1 (de) Verfahren zum hydrophilisieren einer poroesen membran
DE2418996A1 (de) Asymmetrische, semipermeable membranen aus polybenz-1,3-oxazindionen-2,4
DE2431071A1 (de) Asymmetrische, semipermeable membranen aus cyclischen polyharnstoffen
EP1807175B1 (fr) Membrane servant a separer des melanges de matieres, et son procede de production
DE60111791T2 (de) Hohlfaser-Membrane und ihre Herstellung
DE1794191A1 (de) Mikroporoese Membran
DE2625681A1 (de) Trennmembran
DE3042110C2 (fr)
DE69831305T2 (de) Hohlfaser-filtrationsmembran auf polyacrylnitrilbasis
DE102004009877B4 (de) Offenporige Filtrationsmembran und Verfahren zu deren Herstellung

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase