WO2012022406A1

WO2012022406A1 - Membrane comprising a selectively permeable polymer layer of a highly branched polymer

Info

Publication number: WO2012022406A1
Application number: PCT/EP2011/003595
Authority: WO
Inventors: Matthias Koch; Gerhard Jonschker
Original assignee: Merck Patent Gmbh
Priority date: 2010-08-18
Filing date: 2011-07-19
Publication date: 2012-02-23
Also published as: DE102010034700A1

Abstract

The present invention relates to a novel membrane comprising a selectively permeable polymer layer, wherein the selectively permeable polymer layer can be obtained by reacting a hyperbranched polymer with a compound A that reacts with end groups of the hyperbranched polymer. Furthermore, the invention relates to the use of a hyperbranched polymer for producing a membrane comprising a selectively permeable polymer layer and to a method for producing the membrane according to the invention using a hyperbranched polymer.

Description

MEMBRANE WITH SELECTIVELY PERMEABLE POLYMER LAYER OF HIGH-BRANCHED POLYMER

The present invention relates to a novel membrane comprising a selectively permeable polymer layer, which is selectively permeable

Polymer layer by reacting a hyperbranched polymer having reacted with end groups of the hyperbranched polymer

Compound A is available. Furthermore, the invention relates to the use of a hyperbranched polymer for producing a membrane

comprising a selectively permeable polymer layer and a method for producing the membrane of the invention using a hyperbranched polymer.

Due to the growing demand for drinking water and / or purified industrial water, there is a great interest in improved processes for desalination and / or purification of water.

In the context of this application, the term desalting means a reduction in the content of ionic compounds dissolved in water

Connections understood. In the context of this application, desalting is preferably understood as meaning a reduction in the content of those ions which occur in higher concentrations in seawater and brackish water. These include the ions Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , Cl ^" , HCO ₃ ^" and S0 ₄ ^{2 '} ,

in particular Na ⁺ and Cl ^" .

One of the most technically significant processes for desalination of water is reverse osmosis (RO), which uses membranes with high permeability to water and low permeability to ions dissolved in water

(selectively permeable membranes). Under a selectively permeable membrane is in the sense of this

Application understood a membrane which has a high permeability (permeability) for the molecules of the solvent, but only a low permeability for dissolved in the solvent compounds. Preferably, in the context of this invention, the solvent is water and the dissolved compounds are predominantly dissolved ionic compounds, including those preferred in the above

Desalination of water called particularly relevant ions.

Reverse osmosis defines a process in which the thermodynamically favored process of osmosis is reversed by a selectively permeable membrane by the application of a pressure which exceeds the osmotic pressure. The water molecules are under the application of said pressure by a selectively permeable

Membrane pressed, with a large part of the dissolved in the water

Components is retained by the membrane. In this way, water with a reduced content of dissolved components can be obtained. Typically, in the prior art in desalting water by reverse osmosis pressures between 50 and 70 bar used. Selectively permeable membranes for use in reverse osmosis are in particular characterized in that they are largely impermeable to substances dissolved in the solvent, even for small, singly charged ions. Such selectively permeable membranes are also referred to as reverse osmosis membranes. Reverse osmosis membranes effectively retain particles and minute solutes less than one nanometer in size.

Also useful in reverse osmosis are nanofiltration membranes, but there are limitations. In terms of their separation limits, nanofiltration membranes are to be classified between reverse osmosis membranes and ultrafiltration membranes. They do not effectively separate but retain the smallest solutes, such as monovalent alkali or halide ions, unlike reverse osmosis membranes

divalent ions as well as larger organic molecules.

Typically, for nanofiltration membranes, separation limits of 1 to 10 nm are given. For water desalination by reverse osmosis nanofiltration membranes can be used advantageously in combination with reverse osmosis membranes, for example by

Pre-connection of the nanofiltration membrane in front of the reverse osmosis membrane. Ultrafiltration membranes do not retain dissolved salts and small molecules, but only large molecules such as proteins.

Ultrafiltration membranes are therefore not suitable for use in reverse osmosis as the sole separation membranes, but they can also be combined with, for example, upstream of them, as well as nanofiltration membranes with reverse osmosis membranes.

For seawater desalination, it is desirable that a retention of greater than 95% of the solutes be achieved, preferably greater than 99%. Within the meaning of this application, a retention of 95% of the dissolved constituents is understood to mean that the mass content of all dissolved solids (TDS) through the membrane is reduced by 95%. With a salt retention of 99%, for example, from seawater with a TDS of 35,000 mg / L by the process of desalting by reverse osmosis desalted water with a TDS of 350 mg / L is obtained. For the desalination of

Brackish water or other less saline aqueous solutions may have lower retention, for example between 80 and 95%, to obtain water with a sufficiently low dissolved salt content for use as drinking water. Since salts form the overwhelming majority of the dissolved constituents in typical solutions to be desalinated, such as seawater and brackish water, the terms "retention of dissolved substances" and "salt retention" are used interchangeably below.

In order to make the technique of reverse osmosis more energy-efficient and thus more cost-effective, there is a need for novel selectively permeable ones

Membranes which have one or more of the following properties or advantages:

- The membranes have compared to the prior art

known membranes have a higher salt retention, the flow rate being comparably high; in particular it is

desirable that the membranes contribute increased salt retention typical for technical desalination plants

Have flow rates or higher flow rates

furthermore, it is desirable for certain applications that the membranes have a higher flow rate than the membranes known in the prior art at the same operating pressure, the salt retention being comparably high or higher

the membranes have a high durability during operation,

in particular a high stability to chlorinated water

Furthermore, there is a need for membranes with a defect-free, thin selectively permeable layer as well as methods for their

Production.

Known in the art are selectively permeable

Composite membranes comprising a

Microporous support layer on which a selectively permeable polymer layer, usually made of polyamide, is applied. The microporous carrier layer is permeable to water and compounds dissolved therein. The selectively permeable polymer layer is substantially impermeable to compounds dissolved in water so that the entire composite membrane comprising the selectively permeable polymer layer and the microporous support layer has selectively permeable properties.

The selectively permeable polymer layer can, as in, inter alia

US 4,277,344 and US 3,744,642 is described by

Interfacial polymerization of an aromatic diamine monomer and an aromatic tricarboxylic acid chloride monomer on

microporous carrier layer are formed.

For the purposes of this invention, interfacial polymerization means all polymerization reactions taking place at an interface. Preferred are under

Interfacial polymerizations understood polycondensation reactions, which take place at an interface. Preferably, this interface is formed by two solvents insoluble in each other, wherein each one of the two reactants in one of the solvents and the other dissolved in the other solvent. An overview of interfacial polymerization reactions is provided, inter alia, by EL Wittbecker, PW Morgan, S.L Kwolek, J. Pol. Be. 1959, 40, 289-297 and PW Morgan, SL Kwolek, J. Pol. Be. 1959, 40, 299-327. Various other low molecular weight monomer compounds are in the

Prior art described for this use. For example, in the application US 4,876,009 the use of a

Tetrakisaminomethylderivats as the amino component and a

Dicarboxylic acid chloride as the carboxylic acid component disclosed.

The application US 4,259,183 discloses the use of secondary diamines as the amine component. Furthermore, the describes

Application that the amine component can also be an oligomer which by pre-reaction of the diamine with an aromatic

Compound bearing two or three carboxylic acid groups can be prepared.

US Pat. No. 5,271,843 discloses the use of an oligomeric amine component which consists of a central trimesic acid nucleus and three phenylenediamine radicals bound in a star shape. When

Carboxylic acid component is used trimesic acid chloride. Further examples of the use of low molecular weight oligomers

Compounds which subsequently in a

Cross-linked polymerization reaction are crosslinked in

US 4,606,943 and EP 0061782 A2.

However, the prior art processes in which low molecular weight monomers are reacted in an interfacial polymerization typically have the following drawback: if one wishes to increase the salt retention of the membranes, then it is necessary in the prior art processes to use membranes with higher Layer thicknesses to be used, since in these methods typically occurring membrane defects in thin films have a strong negative impact on the salt retention. However, increasing the layer thickness generally entails the disadvantage of a reduced flow rate. Consequently an increase in salt retention is possible only with a significant reduction in the flow rate, which is undesirable in many cases.

There is therefore a need for novel membranes which have an increased salt retention combined with a comparatively high or increased flow rate, as well as to processes for their

Production.

Also known in the art is the use of

Dendrimers in the interfacial polycondensation of aromatic amines with aromatic carboxylic acid chlorides to produce selectively permeable membranes. The application WO 2007/018392 discloses polyamidoamine dendrimers which can be added as additives to either the amine component or the carboxylic acid component.

In EP 0780152 B1, the use of polyethyleneimine and

Polypropyleneimine dendrimers described which are crosslinked with trimesoyl chloride to a selectively permeable polymer layer.

It is described in the aforementioned applications that the selectivity and the flow rate can be improved by the use of the dendrimers as reactive components.

However, the use of dendrimers as membrane components is associated with high costs because dendrimers must be prepared stepwise via controlled organic chemical reactions. Furthermore, due to the structure of dendrimers, the functional groups are concentrated at the surface, thereby greatly increasing their density from the core to the outer sphere. However, these density differences result in inhomogeneities in the polymer layer, which reduce the efficiency and permeation selectivity of the membrane. As a result, when using dendrimers as membrane components, typically membranes with high to very high salt retention can not be obtained. There is therefore still a need for novel membranes comprising a selectively permeable polymer layer of small thickness and

homogeneous and defect-free structure with which a high salt retention can be achieved. In the context of the present invention, it has now been found that such membranes are selectively permeable by using a hyperbranched polymer as the reactive component in the preparation of

Polymer layers can be obtained. The invention relates to a membrane comprising at least one selectively permeable polymer layer, wherein the selectively permeable

Polymer layer is obtainable by reacting a hyperbranched polymer with a hyperbranched polymer endblocking compound A having two or more reactive groups.

Preferred embodiments of the hyperbranched polymer and compound A are shown in later sections.

For the purposes of this invention, the term hyperbranched polymer is understood to mean compounds which are in a single-stage

Polymerization reaction using at least one

Type of monomer which has more than two reactive functional groups and thereby introduces branching into the polymer can be formed.

The monomers mentioned with more than two reactive functional

Groups preferably have a group a and at least two groups b (starting from _x monomer with x> 2), where a and b react with one another. Both group a and group b may be reversibly blocked.

Furthermore, the monomers can also be formed in situ from other building blocks starting at _x with x> 2.

The polymers formed therefrom usually have exactly one group a. When using ab ₂ monomers (x = 2), the polymers formed have a number of groups b, which is approximately equal to the number of built-in monomer units corresponds. These free groups b are distributed over the entire molecule (in contrast to dendrimers, they are not only located outside the molecule) and are generally referred to as end groups in the context of this application. The hyperbranched polymers are irregularly branched and polydisperse, since they result from a polymerization reaction in which there is basically no complete and uniform reaction of all reactive groups present. Irregularly branched means in this context that in addition to branched sections in the polymer sequences are present in which no branches are present and are therefore linearly constructed.

For an overview of the synthesis, properties and use of hyperbranched polymers, see, for example, the review article by C. Gao et al., Prog. Polym. Be. 29, 2004, 183-275.

Dendrimers, unlike hyperbranched polymers, are usually prepared in a multi-step reaction sequence starting from a polyfunctional starter molecule by stepwise coupling of polyfunctional branching-introducing compounds. Furthermore, in contrast to this divergent method, a convergent method for producing dendrimers is also known.

Dendrimers are completely regularly branched, monodisperse compounds. They are thus not included in the above-defined concept of hyperbranched polymers.

The selectively permeable polymer layer preferably has a high

Permeability to water molecules and low permeability to dissolved compounds in the water, especially for dissolved in water ionic compounds. As a result, for example, when used in reverse osmosis, the membrane causes a reduction in the content of ionic compounds dissolved in the water. The invention thus in addition to the membrane described above, the use of the membrane to reduce the content of dissolved ionic compounds in water. When used for desalination of sea or brackish water, the membrane in particular causes a reduction in the content of Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , Cl ^" , HCO ₃ ^" and S0 ₄ ^{2 "} , most preferably one

Reduction of Na ⁺ and CI content ^" .

In addition to use in reverse osmosis, the membranes of the invention can also be used as nanofiltration membranes, but the use in reverse osmosis is preferred. Aqueous solutions which can be desalted and / or purified with the membranes according to the invention are in particular

Sea water, brackish water, river water, industrial and household wastewater, industrial and household water and industrial water

Freshwater. Furthermore, the drinking water treatment on ships and in mobile facilities is possible. Furthermore, in technical

Processes obtained are highly saline solutions such as brine or metal-containing solutions purified or concentrated.

Under purification of water for the purposes of this invention, the

Removal of compounds dissolved in water understood.

In a preferred embodiment of the invention, the membrane is used for the purification of industrial and waste water. In this case, in addition to reducing the content of dissolved ionic

Compounds a reduction in the content of water-soluble nonionic compounds such as polar organic compounds. For purification of industrial and waste water membranes of the invention are preferably used in combination with

upstream ultrafiltration and / or nanofiltration membranes used.

In another embodiment, the membranes may be used to produce very low salt water, for example less than 1 mg / L, for industrial, engineering and research applications (deionized water). Very low salinity water For example, by repeated reverse osmosis to the

membranes according to the invention are produced.

The various uses of the membrane described above are also the subject of the invention in addition to the membrane itself.

In one possible embodiment of the invention, the

Purification of water used two or more consecutively arranged membranes. As a result, a higher degree of desalination of the water can be achieved. In an alternative embodiment of the invention, desalting is carried out by reverse osmosis on only one membrane.

Another object of the invention is a module for desalination comprising at least one membrane according to the invention, as in

Defined below. Preferably, the water desalination module is selected from spiral wound modules (SWM). Spiral-wound modules are characterized by the following advantages when used for desalination on an industrial scale. They allow a high packing density, d. H. a big

Membrane surface based on the volume of the device. With industry standard spiral wound modules

Packing densities of up to 1000 m ² / m ³ can be achieved. Furthermore, spiral wound modules can be produced cost-effectively. The construction of spirally wound modules for desalination of water is known to those skilled in the art of reverse osmosis. A detailed description can be found, inter alia, R. Rautenbach et al., Membrane Processes:

Fundamentals of module and system integration, Springer-Verlag, 2003.

In a preferred embodiment of the invention, the selectively permeable polymer layer has a thickness of 1 nm to 10 μm, particularly preferably from 5 nm to 1 μm and very particularly preferably from 10 nm to 100 nm. The selectively permeable polymer layer preferably consists of polyamide, polyurethane, polyurea, polyester and / or polyimine, particularly preferably polyamide. However, it may also contain other polymerized functional groups. For the purposes of the present application, a polyamide is understood as meaning all condensation products of organic amines and organic acids, including carboxylic acids, sulfonic acids, sulfinic acids,

Phosphoric acids, phosphonic acids and phosphinic acids. A polyamide is preferably understood as meaning a polycarboxylic acid amide.

In a preferred embodiment of the invention, the selectively permeable polymer layer is applied to a carrier layer. The carrier layer is preferably microporous or nanoporous and thus permeable to substances dissolved in water. According to the invention, it has a thickness of 10-200 μm, preferably 15-150 μm. It can be constructed homogeneously or constructed from several different materials and / or layers. According to the invention, the carrier layer is hydrophilic and preferably consists of a polymeric material, more preferably of a material selected from the group comprising polysulfones, polyethersulfones, polyamides, polyethylenes, polypropylenes, polyesters, polyacrylonitriles and polyvinylidene fluorides. The membrane according to the invention can be used in addition to the selective

permeable polymer layer and the carrier layer still contain other layers. In particular, the membrane may be applied to a layer of textile, fabric or non-woven. Membranes having the above structure containing an active selective permeable polymer layer and a porous support layer are referred to as composite membranes. Basic methods for their preparation are known to the person skilled in the art and are disclosed, for example, in US Pat. No. 4,277,344.

The selectively permeable polymer layer is obtained according to the invention by reacting a hyperbranched polymer with a compound A reacting with end groups of the hyperbranched polymer and having two or more reactive groups. The compound A may be a low molecular weight organic compound or a polymeric compound represent, for example, a hyperbranched, branched or linear polymer. Preferably, the compound A is a low molecular weight organic compound.

In the context of this application, a low molecular weight organic compound is understood as meaning a compound which is composed of one or a few (2-10) repeat units.

A polymeric compound is accordingly understood to mean a compound which is composed of many (more than 11, preferably more than 50) identical or different repeat units. In this case, a polymeric compound is referred to as a linear polymer, if it has no branches. As branched polymer is

correspondingly designates a polymeric compound which

Branching has. In the strict sense, and as a distinction from the above-defined hyperbranched polymer as well as the dendrimer, the branched polymer is a polymer which has branches, but is not included in the above-mentioned definitions of a hyperbranched polymer and a dendrimer. in a preferred embodiment of the invention is characterized by the

Reaction of compound A with the end groups of hyperbranched polymer molecules formed a polymer network.

The term polymer network is understood to mean a branched polymer in which the individual chains are repeatedly linked to one another.

In this case, the reaction of the compound A brings about the fact that several different hyperbranched polymer molecules are covalently bonded to one another (intermolecular crosslinking reaction), as well as that the hyperbranched polymer molecules are crosslinked in themselves

(intramolecular crosslinking reaction).

It can in addition to the compound A more compounds

used together with compound A, which end groups of the hyperbranched polymer. These compounds may be small molecules or polymers, for example hyperbranched, branched or linear polymers.

Furthermore, the selectively permeable polymer layer can also by

Reaction of several different hyperbranched polymers with the compound A can be obtained. You can also continue

Mixtures of one or more hyperbranched polymers with linear or branched polymers and / or low molecular weight

Connections are used.

In a preferred embodiment, the selectively permeable

Polymer layer by reaction of not more than two

obtained different hyperbranched polymers. In a particularly preferred embodiment, the selectively permeable polymer layer is hyperbranched by reacting exactly one type

Contain polymers, i. by reaction of the same hyperbranched polymers.

For the purposes of this application, the term "different hyperbranched polymer" is to be understood as meaning that the hyperbranched polymer in question is obtained from monomers in which at least one monomer has a different structure than in the original polymer to be compared, or it should be understood in the context of this application in that the polymer was formed under different reaction conditions, for example with a different stoichiometry of the starting compounds or with a different reaction procedure. If none of the above cases exists, i. If the polymer was formed from the same starting compounds and under the same reaction conditions, in the present application the polymer in question is understood to be the same hyperbranched polymer.

The reaction of the hyperbranched polymer with a compound A reacting with end groups of the hyperbranched polymer is preferred an interfacial polymerization reaction, most preferably an interfacial polycondensation reaction.

The reaction is preferably characterized in that one of the two reactants, either the hyperbranched polymer or the compound A, is in aqueous solution and the other reactant is in organic solution or one

water-insoluble, preferably liquid pure substance represents. The aqueous solution and the organic solution are barely miscible with each other under the given conditions, so that a phase boundary is formed. The two solutions are referred to in a following section as solution L1 and solution L2.

Typically, in the above-described interfacial polymerization reaction, as is known to those skilled in the art, inter alia, E.W. Wittbecker, P.W. Morgan, S.L. Kwolek, J. Pol. Be.

1959, 40, 289-297 and P.W. Morgan, S.L. Kwolek, J. Pol. Be. 1959, 40, 299-327, a thin polymer layer at the boundary between the two phases. It is furthermore generally preferred according to the invention for the hyperbranched polymer to be present in aqueous solution. The solubility of the components of the aqueous solution can be achieved by suitable measures such as an adjustment of the pH and by the addition of solubilizing additives.

In an alternative embodiment of the invention, the hyperbranched polymer is in organic solution. In this case, it is preferred that the hyperbranched polymer has end groups that react with amines, such as isocyanates, carboxylic acid esters or carboxylic acid chlorides. These end groups are hydrophobic and do not affect the solubility in organic solvents. In addition, groups may be used as substituents which further improve the solubility in organic solvents, such as. B. alkyl chains. In a further embodiment of the invention, in a variant of the interfacial polymerization reaction, the compound A is reacted in the gaseous state. The hyperbranched polymer is in this case in solution, preferably in aqueous solution. It is further preferred according to the invention that the hyperbranched polymer is used in solution together with another compound B in the reaction, wherein both the hyperbranched polymer and the compound B react with the compound A. In a particularly preferred embodiment, the

hyperbranched polymer and the compound B in a ratio of the mass fractions in solution of 100: 1 to 1: 100 used. Very particularly preferred is a ratio of the mass fractions of 20: 1 to 1:20. Preferred embodiments of compound B will be shown in later sections.

In the following, preferred embodiments of the method for producing the membranes of the invention are described.

In such a preferred embodiment, at least two solutions are used for the preparation of the membranes according to the invention, a solution L1 and a solution L2. At least one of the two

Solutions L1 and L2 contains a hyperbranched polymer. Furthermore, at least one of the two solutions contains a compound A, wherein the compound A and the hyperbranched polymer with which the

Compound A responds, each in a different solution. The solution L1 is an aqueous solution and therefore preferably contains compounds with good water solubility. The solution L1 comprises at least one compound containing functional groups G1. This compound may be a hyperbranched polymer, a linear or branched polymer, and a low molecular weight compound. The solution L2 represents an organic solution and therefore preferably contains compounds with good solubility in organic

Solvents. The solution L2 comprises at least one compound containing functional groups G2. This compound may be a hyperbranched polymer, a linear or branched polymer, and a low molecular weight compound.

According to the invention, the functional groups G1 and the functional groups G2 in the reaction in which the selectively permeable polymer layer is formed react with one another, the compounds containing these groups being linked to one another. However, there may be other chemical groups in addition to the functional

Groups G1 and G2 in the reaction in which the selectively permeable polymer layer is formed, react with each other. The functional groups G1 preferably represent groups which dissolve in an aqueous solvent, for example amines, alcohol groups or free carboxylic acids.

The functional groups G 2 are preferably groups which dissolve in organic solvents, for example isocyanates, carboxylic esters, carboxylic acid chlorides or thiols.

In a preferred embodiment, the solution L1 comprises a hyperbranched polymer containing functional groups G1 as end groups and optionally one or more compounds B, which preferably contain functional groups G1. The presence of one or more compounds B in the solution L1 constitutes a particularly preferred embodiment of the invention. Furthermore, the solution L1 may optionally contain one or more further polymers, which may be linear, branched or hyperbranched. Furthermore, further low molecular weight compounds may be contained in the solution L1.

In a likewise preferred embodiment, the solution L2 comprises a compound A containing functional groups G2 and optionally one or more polymers which may be linear, branched or hyperbranched. Furthermore, additional low molecular weight

Be contained compounds.

Both solution L1 and solution L2 may optionally contain one or more additives, such as surfactants or solubilizers, for example, DMSO or camphorsulfonic acid.

By the addition of solubilizing additives is the

Mixing of the aqueous and the organic phase at the

Facilitated boundary layer, whereby the interface reaction takes place more rapidly and in a wider range.

In a particularly preferred embodiment of the invention, the selectively permeable polymer layer is produced by

a) a solution of the hyperbranched polymer to any

Substrate layer is applied and then

b) coated with the hyperbranched polymer solution

Substrate layer with a compound A, which may be in solution, in liquid form or in the gas phase, is brought into contact, wherein the compound A with end groups of

hyperbranched polymer reacts.

In an alternative embodiment of the invention, the selectively permeable polymer layer is prepared by

a) a solution containing a compound A to any one

Substrate layer is applied and then

b) coated with the solution containing a compound A.

Substrate layer with a solution containing a hyperbranched polymer is brought into contact, wherein the compound A with

End groups of the hyperbranched polymer reacts.

In both cases, the solution used in a) is preferably an aqueous solution and the solution used in b) is an organic solution. Substrate layer is understood within the meaning of this invention to mean any layer of solid material. This is preferably understood to mean a water-permeable thin layer, more preferably a microporous or nanoporous polymer layer. Even more preferably, the substrate layer is the carrier layer of the membrane as defined above.

In addition to the preferred embodiment shown here, other variants of the method according to the invention and of the present application are included. This includes, for example, the

Reaction of the hyperbranched polymer with the compound A to form a selectively permeable polymer layer in the absence of a substrate layer and / or the use of two organic solvents which form a phase boundary instead of an organic one

Solvent and an aqueous solution. In a further embodiment of the invention, in a first step, the substrate layer is coated with a solution of a low molecular weight compound which is capable of reacting with the compound A. The preferred embodiments of the above-mentioned low molecular weight compound correspond to the below-mentioned preferred embodiments of the compound B. In a second step, the substrate layer is contacted with a solution of the compound A, whereby a reaction takes place between the low molecular weight compound and the compound A, preferably one

Interfacial polymerization reaction. In a third step, a solution containing a hyperbranched polymer is applied, and the membrane is then contacted in a fourth step with a solution containing the compound A, wherein a reaction takes place between the end groups of the hyperbranched polymer and the compound A, preferably one Interfacial polymerization reaction.

According to a further embodiment of the invention, the third and the fourth steps take place as described above without first performing the first and second steps, wherein the solutions are applied directly to the selectively permeable polymer layer of a membrane. This membrane can be a reverse osmosis membrane, a

Represent nanofiltration membrane or an ultrafiltration membrane.

The process presented above provides a post-treatment of a

Membrane by applying an additional selectively permeable layer, for example, to modify properties of the membrane such as its salt retention and / or their selectivity or durability. Such a post-treatment process is explicitly the subject of the present invention. In a further embodiment of the invention are in the above

the four-step method described above, the third and fourth step are respectively interchanged with the first and second step as defined above, so that first the third, then the fourth, then the first and then the second step, as defined above, follow one another.

Furthermore, a three-, five-, six- or multi-step process analogous to the methods described above is a possible

Embodiment in the context of this invention, as well as methods in which the above steps are performed in any other reasonable order.

The above-described methods for producing the membrane comprising a selectively permeable polymer layer are also

Subject of the invention.

General processes for the preparation of hyperbranched polymers are known to the person skilled in the art. An overview offer among other things

C. Gao et al., Prog. Polym. Be. 29, 2004, 183-275. The hyperbranched polymer in a preferred embodiment of the invention is a polyamide, a polyurethane, a polyurea, a polyimine, a polyether or a polyester, more preferably a polyamide. The polyamide may be a polycarboxylic acid amide,

Polysulfonic acid amide, polysulfinic acid amide, polyphosphoric acid amide, Polyphosphonsäureamid or Polyphosphinsäureamid represent. It is preferred that the polyamide is a polycarboxylic acid amide.

The hyperbranched polymer further preferably contains

Repeat units aromatic compounds. The hyperbranched polymer particularly preferably contains aromatic rings which are substituted by one or more, preferably a plurality of, electron-withdrawing groups, particularly preferably fluorine, chlorine, bromine,

Carboxylic acid derivatives and sulfonic acid derivatives. For the purposes of this invention, an electron-withdrawing group is understood as meaning a functional group or a substituent which exerts a negative inductive and / or mesomeric effect (-I and / or M effect) and thereby the electron density of the aromatic ring to which it binds , degrades.

The hyperbranched polymer preferably contains end groups selected from carboxylic acids, carboxylic acid halides, carboxylic acid anhydrides, carboxylic acid thioesters, carboxylic acid esters, isocyanates, isothiocyanates, carbamates, chloroformates, sulfonic acid halides, sulfonic acids, sulfinic acid halides, sulfinic acids, phosphoric acid halides, phosphoric acids, phosphonic acid halides, phosphonic acids,

Phosphinic acid halides, phosphinic acids, alcohols, amines and thiols. Particular preference is given to carboxylic acid halides,

Carboxylic acid anhydrides, carboxylic acid esters, alcohols and amines, including very particularly preferably carboxylic acid halides and amines.

For the purposes of this application, the term end groups is understood as meaning functional groups of a polymer which, according to the

Polymerization distributed throughout the molecule are present.

In particular, by the term of the end groups of the polymer herein are those groups b of one in the polymerization reaction

understood monomer units from ₂ understood in the

Polymerization reaction did not react. The hyperbranched polymer preferably contains one type of end groups or two different end groups. It can also contain more than two different end groups. It preferably contains one, two or three different end groups, more preferably one or two different end groups.

Subsequent functionalization can transform the chemical functionality of one end group into another chemical functionality. In this way, new, previously non-existent functional groups can be introduced as end groups. For example, a carboxylic acid function can be converted to a carboxylic ester function or carboxylic acid chloride function. Suitable methods are known to those skilled in the art of polymer chemistry.

The hyperbranched polymer is obtainable from a polymerization reaction of one or more different monomers. In a preferred embodiment, it is obtainable from a polymerization reaction of a monomer. In a further preferred embodiment, it is obtainable from a polymerization reaction of two different monomers.

In a preferred embodiment of the invention that is

hyperbranched polymer either from a polymerization reaction of the same monomers of the formula (I) Z (NHR ¹ ) _n (X) _m

Formula (I), available, or the hyperbranched polymer is from a

Polymerization reaction of different monomers of the formula (II)

Z (NHR ¹ ) ₀ (X) _p

Formula (II) available, whereby the following applies for the occurring symbols and indices:

Z is a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, each of which is substituted by one or more R ² radicals can, wherein one or more non-adjacent CH ₂ groups by

R ² C = CR ² , CEC, Si (R ² ) ₂ , C = O, C = S, C = NR ² , P (= O) (R ² ), SO, SO ₂ , NR ² , O, S , COO or CONR ² may be replaced and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ , or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, each may be substituted by one or more radicals R ² , or a combination of these groups;

R ¹ is the same or different at each occurrence, H, D, F, Cl, Br, I, CN or NO ₂ or an alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms, the each may be substituted with one or more radicals R ² , wherein one or more CH ₂ groups by Si (R ² ) ₂ , C = O, C = S, C = NR ² , P (= O) (R ² ) , SO, SO ₂ , NR ² , O, S, COO or CONR ² may be replaced and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ , or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ;

R ² is the same or different H or one at each occurrence

aliphatic, aromatic and / or heteroaromatic organic radical having 1 to 20 C atoms;

X is the same or different at each occurrence

A group which combines with amino groups in a condensation or addition reaction preferably a carboxylic acid, a carboxylic acid halide, a carboxylic acid anhydride

Carboxylic thioester, a carboxylic acid ester, an isocyanate, a Isothiocyanate, a chloroformate, a sulfonic acid halide, a sulfinic acid halide, a phosphoric acid halide

Phosphonic acid halide or a phosphinic acid halide; has a value of 1 to 5, where n + m has a value of 3 to 6; has a value of 1 to 5, where n + m has a value of 3 to 6; has a value of 0 to 6, wherein o + p has a value of 1 to 6; p has a value of 0 to 6, wherein o + p has a value of 1 to 6; and wherein for at least one of the monomers of the formula (II) it must hold that o + p has a value of 3 to 6.

For the purposes of the present application, an aromatic or heteroaromatic ring system is to be understood as meaning a system which does not necessarily contain only aryl or heteroaryl groups, but in which several aryl or heteroaryl groups are also replaced by a nonaromatic moiety (preferably less than 10% of that other than H. Atoms), such as. As an sp ³ -hybridized C, Si, N or O atom, a sp ² - hybridized C or N atom or a sp-hybridized carbon atom, may be connected. Furthermore, systems in which two or more aryl or heteroaryl groups via single bonds

are linked together, as aromatic or heteroaromatic ring systems for the purposes of this invention understood, such as systems such as biphenyl, terphenyl or diphenyltriazine.

An aromatic or heteroaromatic ring system as defined above is understood in particular to mean groups which are derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene,

Benzphenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, Pentacene, benzpyrene, biphenyl, biphenylene, terphenyl, terphenyls, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene,

Tetrahydropyrene, cis or trans indenofluorene, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indolocarbazole, indenocarbazole, pyridine,

Quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyrimididazole, Pyrazine imidazole, quinoxaline imidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1, 2-thiazole, 1, 3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine,

Benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene,

4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubin, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1, 2,3-triazole, 1, 2,4-triazole, benzotriazole, 1, 2, 3-oxadiazole, 1, 2,4-oxadiazole, 1, 2,5-oxadiazole, 1, 3,4-oxadiazole, 1, 2,3-thiadiazole, 1, 2,4-thiadiazole, 1, 2,5- Thiadiazole, 1, 3,4-thiadiazole, 3,5-triazine, 1, 2,4-triazine,

1, 2,3-triazine, tetrazole, 1, 2,4,5-tetrazine, 1, 2,3,4-tetrazine, 1, 2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole, or combinations thereof Groups.

An aryl group or heteroaryl group is used in the sense of

present application either a simple aromatic cycle, ie benzene, or a simple heteroaromatic cycle, for example pyridine, pyrimidine or thiophene, or a fused (fused) aromatic or heteroaromatic polycycle, for example

Naphthalene, phenanthrene, quinoline or carbazole understood. A condensed (fused) aromatic or heteroaromatic

Polycycle consists in the context of the present application of two or more condensed simple aromatic or

heteroaromatic cycles.

An aryl or heteroaryl group, as defined above, is understood in particular to mean groups which are derived from benzene, Naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene, benzphenanthrene, tetracene, pentacene, benzpyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, Pyridine, quinoline, isoquinoline, acridine,

Phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyrimididazole, pyrazine imidazole, quinoxaline imidazole, oxazole, Benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1, 2-thiazole, 1, 3-thiazole, benzothiazole,

Pyridazine, benzopyridazine, pyrimidine, benzpyrimidine, quinoxaline, pyrazine, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1, 2,3-triazole, 1, 2,4-triazole, benzotriazole, 1, 2,3-oxadiazole, 1, 2,4-oxadiazole, 1, 2,5-oxadiazole, 1, 3,4-oxadiazole, 1, 2,3-thiadiazole, 1, 2,4-thiadiazole, 1, 2,5-thiadiazole, 1, 3, 4-thiadiazole, 1, 3,5-triazine, 1, 2,4-triazine, 1, 2,3-triazine, tetrazole, 1, 2,4,5-tetrazine, 1, 2,3,4-tetrazine, 1, 2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole.

In the context of the present invention, the radicals methyl are preferably chosen from a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms. Ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, neo-pentyl, n-hexyl, cyclohexyl, neo-hexyl, n-heptyl,

Cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, Ethinyl, propynyl, butynyl, pentynyl, hexynyl or octynyl understood. In a preferred embodiment, the group Z is selected from an aryl or heteroaryl group having 5 to 30 aromatic ring atoms, each of which may be substituted by one or more R ² , more preferably an aryl or heteroaryl group having 5 to 20 aromatic ring atoms, the each may be substituted with one or more R ² radicals. Most preferably, Z is selected from an aryl group having 6 to 10 aromatic ring atoms or a heteroaryl group having 5 to 10 aromatic ring atoms. Even more preferably Z is benzene, pyridine, pyrimidine, pyrazine, pyridazine, triazine, furan, thiophene, pyrrole, imidazole, pyrazole, naphthalene, quinoline, isoquinoline, benzimidazole, benzofuran, indole, isoindole, oxazole, isoxazole, thiazole and isothiazole. wherein said groups may be substituted with one or more R ¹ .

In a further preferred embodiment of the invention, R ^{1 is the} same or different at each occurrence as H, D, F, Cl, Br, I, CN or NO ₂ or an alkyl group having 1 to 10 C atoms or an alkenyl or

Alkynyl group having 2 to 10 carbon atoms, each of which may be substituted by one or more R ² radicals, wherein one or more CH ₂ groups by C = O, C = S, C = NR ² , SO, SO ₂ , NR ² , O, S, COO or CONR ² may be replaced and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ , or an aryl or heteroaryl group having 5 to 0 aromatic ring atoms which may be substituted by one or more R ² radicals.

In a particularly preferred embodiment of the invention, X is the same or different at each occurrence selected from a

Carboxylic acid, a carboxylic acid halide, carboxylic anhydride, Carbonsäurtioester, carboxylic acid esters, isocyanate or isothiocyanate.

In a preferred embodiment of the invention, the hyperbranched polymer is obtainable from a polymerization reaction of a single monomer of formula (I).

In this case, it is preferable that the sum of n and m has a value of 3 or 4, more preferably 3.

Very particularly preferably, in formula (I) n has a value of 2 and m has a value of 1, so that the compound corresponds to formula (Ia): Z (NHR ¹ ) ₂ X

Formula (la).

In an alternative preferred embodiment of the invention, the hyperbranched polymer is obtainable from a polymerization reaction of two different monomers of formula (II).

In this case, it is preferable that one of the two monomers has the formula (IIa)

Z (NHR) ₀ formula (IIa), wherein o has a value of 2 or 3 assumes, and the other monomer has the formula (IIb)

Z (X) p formula (IIb), wherein p assumes a value of 2 or 3, and wherein not both indices and p can be simultaneously 2 and wherein X is as defined above and may be the same or different at each occurrence.

In an alternative embodiment of the invention that is

hyperbranched polymer from a polymerization reaction of

Available compounds, which are composed of a small number of identical or different repeating units. These compounds are preferably synthesized from 2 to 20 repeat units, more preferably from 4 to 10 repeat units.

These compounds can be produced for example by controlled construction by means of protective group technology. In the polymerization reaction for producing the hyperbranched polymer, these compounds may be used as the sole monomers, or they may be used together with other monomers of the formula (I) and / or the formula (II).

Examples of monomers of the formula (I) and (II) from which the hyperbranched polymers according to the invention can be prepared are listed below.

According to the invention, the compound A has two or more reactive

Groups on. It preferably has two, three or four reactive groups. The reactive groups are functional groups which covalently bond to the end groups of the hyperbranched polymer, preferably in a condensation or addition reaction.

The reactive groups of compound A are selected from

Carboxylic acid halides, carboxylic anhydrides,

Carboxylic acid thioesters, carboxylic acid esters, isocyanates, isothiocyanates, carbamates, chloroformates, sulfonic acid halides, sulfonic acids, sulfinic acid halides, sulfinic acids, phosphoric acid halides, phosphoric acids, phosphonic acid halides, phosphonic acids,

Phosphinic acid halides, phosphinic acids, alcohols, amines and thiols.

It is preferred according to the invention that the compound A has two or more reactive groups which combine with amino groups, preferably in a condensation or an addition reaction. It is particularly preferred according to the invention that the reactive groups of the compound A are selected from carboxylic acid halides, carboxylic anhydrides and isocyanates.

Further preferably, the compound A is an aromatic or heteroaromatic compound.

Further preferably, the compound A contains one or more aromatic rings, which are substituted with one or more, preferably more, electron-withdrawing groups, including more preferably fluorine, chlorine, bromine, carboxylic acid derivatives and

Sulfonic acid derivatives.

Most preferably, the compound A is selected from

Trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride as well

Phthalic anhydride.

The compound A, when present as a pure substance, according to the invention can be used in liquid or in gaseous form. It is

According to the invention preferred that the compound A is used in solution present. It is particularly preferred that the compound A is used in organic solution herein. Preferred solvents are: n-hexane, cyclohexane, iso-hexane, pentane and heptane. In this case, it is further preferred that the hyperbranched polymer is in aqueous solution.

Compound B according to the invention has one or more reactive groups. Preferably, the compound B has two or three reactive groups. The reactive groups of compound B are preferably selected from carboxylic acid halides, carboxylic acid anhydrides,

Carboxylic acid thioesters, carboxylic acid esters, isocyanates, isothiocyanates, carbamates, chloroformates, sulfonic acid halides, sulfonic acids, sulfinic acid halides, sulfinic acids, phosphoric acid halides, phosphoric acids, phosphonic acid halides, phosphonic acids, Phosphinic acid halides, phosphinic acids, alcohols, amines and thiols. Of these, particular preference is given to carboxylic acid halides, carboxylic anhydrides, carboxylic esters, isocyanates, alcohols, amines and thiols, very particularly preferably to alcohols and amines. Further preferably, the compound B is an aromatic or heteroaromatic compound.

Further preferably, the compound B contains one or more aromatic rings, which are substituted with one or more, preferably more, electron-withdrawing groups, including more preferably fluorine, chlorine, bromine, carboxylic acid derivatives and

Sulfonic acid derivatives.

In a preferred embodiment of the invention, the reactive groups of the compound B are identical to the end groups of the hyperbranched polymer or represent derivatives of these groups.

According to the invention, the reactive groups of the compound B and the end groups of the hyperbranched polymer are selected such that they react with the reactive groups of the compound A.

Very particularly preferred embodiments of compound B are meta-phenylenediamine, para-phenylenediamine, 1,3,5-phenyltriamine, 3,5-diaminobenzoic acid and meta-aminoisophthalic acid. It is preferred according to the invention that the compound B is used in solution, preferably in aqueous solution, particularly preferably in aqueous solution together with the hyperbranched polymer.

The use of the hyperbranched polymer as a component for producing the selectively permeable polymer layer enables

Providing a substantially defect-free thin selectively permeable layer. As a result, increased salt retention through the membrane can be achieved with the same or only slightly reduced flow rate, preferably a combination of increased salt retention and increased flow rate. The membranes according to the invention preferably have increased salt retention in comparison with membranes of the prior art. More preferably, it is greater than 95%, most preferably greater than 99%, with a flow rate comparable to or higher than prior art membranes.

A further advantage of the method according to the invention is that better control over the thickness of the selectively permeable layer is made possible. The hyperbranched polymer penetrates less deeply into the carrier layer than the low molecular weight reactants used in the prior art in the interfacial polymerization reaction.

Yet another advantage of the membranes obtained by the process according to the invention is their high chemical stability against decomposition by chlorinated water. The polyamide membranes known in the art are in a typical embodiment

(Preparation by interfacial polymerization of phenylenediamine and trimesoyl chloride) aromatic rings, which are substituted either exclusively with amino groups or exclusively with acid chlorides which react with each other to amide bonds. On the aromatic rings, which contain only amine functions, an electrophilic substitution reaction by chlorine or chlorine compounds, which are used to disinfect the water, take place.

This causes a deterioration of the selectively permeable

Properties and finally a decomposition of the membrane. These effects occur to a lesser extent in the membranes according to the invention, since in these the aromatic rings are less electron-donating than in purely amine-functionalized aromatics. In summary, the membranes of the invention have one or more, preferably more of the above advantageous properties. The following embodiments serve to illustrate and illustrate the invention without the subject matter of the invention being restricted to the content of the examples.

embodiments

A) Preparation of hyperbranched polymer P1

3,5-diaminobenzoic acid (4 g, 26.3 mmol) is melted in a Kugelrohr still at a temperature of 250 ° C. After heating at 250 ° C. for 30 minutes, the molten mass is cooled. The resulting solid polymer (3.45 g) is dissolved in NMP (30 g) and precipitated in methanol. The product is characterized by NMR (d ⁶ -DMSO). B) Preparation of Oligomeric Building Block 01 (Comparative Example)

The preparation of the oligomeric building block 01 takes place as described in US Pat. No. 5,271,843.

C) Preparation of the Membrane (Comparative Example Membrane MO)

The polysulfone support layer (stored refrigerated in deionized water + 0.7% sodium bisulfite) is washed for 1 min in deionized water, which becomes water

The membrane is then washed for a further 30 minutes in newly added demineralised water. Subsequently, the

Carrier layer in NaOH solution (pH1) incubated overnight. After that will the support layer washed twice with deionized water and tested for pH neutrality. There are prepared a 3% (wt .-%) of m-phenylenediamine solution in deionized water and a 0.15% (wt .-%) Trimesinsäurechlorid- solution in hexane. The moist support layer is placed on a first glass plate and freed from excess water. There is another glass plate with a window and in the window the

Poured phenylenediamine solution. After incubation for 2 minutes, the solution is poured off, the second glass plate is removed and any remaining solution is removed from the surface. A new glass plate with window is placed and in the window the Trimesoylchlorid solution is given. After incubation for 15 s, the trimesoyl chloride solution is poured off, the membrane is removed from the glass plate and incubated for 10 min

Drying oven heated to 50 ° C. Subsequently, the membrane is dried for 0- 20 min in air at room temperature and then washed for 30-60 min in deionized water. The membrane is stored in deionised water with 0.7% sodium bisulfite until use.

D) Preparation of the Membranes M1-M4 Both from the hyperbranched polymer (P1) and from the oligomeric building blocks (O1), a stock solution is prepared as follows:

15 g are dissolved in 100 ml of 1 M hydrochloric acid. Thereafter, isopropanol is added until the hydrochloride of the polymer precipitates. This is washed with isopropanol and dried. The dry hydrochloride easily dissolves in water with a pH between 2 and 3.

From the stock solutions and a 3% (wt .-%) phenylenediamine solution (PDA) in water, which was adjusted to pH 3 with hydrochloric acid, the following solutions A1 to A4 are prepared: PDA P1 01

A1 40 ml 0 ml 60 ml

A2 20 ml 80 ml 0 ml

A3 40 ml 60 ml 0 ml

A4 80 ml 20 ml 0 ml

To prepare the membranes, the polysulfone support layer (stored cooled in demineralized water + 0.7% sodium bisulfite) for 1 min in demineralized water, the water is exchanged and the membrane is then washed for a further 30 min in newly added demineralized water. Subsequently, the carrier layer is incubated in NaOH solution (pH 11) overnight. Thereafter, the carrier layer is washed twice with demineralized water and tested for pH neutrality. A 0.2% (wt%) trimesoyl chloride solution in hexane is prepared. The moist support layer is placed on a first glass plate and from

Excess water freed. Another glass plate with window is placed and poured into the window one of the solutions A1-A4. After incubation for 2 minutes, the solution is poured off, the second glass plate is removed and any remaining solution is removed from the surface. A new glass plate with window is placed and in the window the Trimesoylchlorid solution is given. After incubation for 3 min, the trimesoyl chloride solution is poured off, the membrane is removed from the

Glass plate removed and heated for 10 min in a drying oven at 70 ° C. The membrane is then allowed to air for 10-20 min

Room temperature dried and then 30-60 min in deionized water

washed. The membrane is stored in deionised water with 0.7% sodium bisulfite until use.

E) Properties of membranes MO - M4

The membranes are tested on a membrane test bench made by OSMO equipped with a transfer cell. A 3.2% solution (wt%) of sodium chloride in water is used as the test solution. This corresponds to an osmotic pressure of about 27 bar. To test the membrane, a pressure of 55 bar is built up and the conductivity of the permeate. This results in the salt content of the permeate. Permeate flux and salt retention are parameters for the performance of the membrane.

The experiments show that the membranes M2, M3 and M4 according to the invention, which were produced using the hyperbranched polymer P1, have improved salt retention and an increased flow rate compared to the membranes known in the prior art.

Claims

claims

Membrane comprising at least one selectively permeable polymer layer, wherein the selectively permeable polymer layer by reacting a hyperbranched polymer with a

End groups of the hyperbranched polymer reacting compound A, which has two or more reactive groups, is available.

Membrane according to claim 1, characterized in that the reaction is an interfacial polymerization reaction.

Membrane according to claim 1 or 2, characterized in that a polymer network is formed by the reaction of the compound A with the end groups of the hyperbranched polymer molecules.

Membrane according to one or more of claims 1 to 3, characterized in that the hyperbranched polymer is used in solution together with another compound B in the reaction, wherein both the hyperbranched polymer and the compound B react with the compound A.

Membrane according to one or more of claims 1 to 4, characterized in that the selectively permeable polymer layer has a thickness of 1 nm to 10 pm, preferably from 5 nm to 1 pm and more preferably from 0 nm to 100 nm.

Membrane one or more of claims 1 to 5, characterized

in that the hyperbranched polymer is a polyamide, a polyurethane, a polyurea, a polyimine, a polyether or a polyester.

7. Membrane according to one or more of claims 1 to 6, characterized in that the hyperbranched polymer either from a polymerization reaction of the same monomers of

Formula (I)

Z (NHR) _n (X) _m

Formula (I), or that the hyperbranched polymer from a polymerization reaction of different monomers of the formula (II)

Z (NHR ¹ ) ₀ (X) p

Formula (II) is available,

the following applies for the occurring symbols and indices:

Z is a straight-chain alkyl group having 1 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms

Atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, each of which may be substituted by one or more R ² radicals, one or more non-adjacent CH ₂ groups being replaced by R ² C = CR ² , C = C, Si (R ² ) ₂ , C = O, C = S, C = NR ² , P (= O) (R ² ), SO, SO ₂ , NR ² , O, S, COO or CONR ² may be replaced and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ , or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, the each may be substituted by one or more radicals R ² , or a combination of these groups; is identical or different H, D, F, Cl, Br, I, CN or NO ₂ or an alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, each with one or more radicals R ² may be substituted, wherein one or more CH ₂ groups by Si (R ² ) ₂ , C = 0, C = S, C = NR ² , P (= 0) (R ² ), SO , SO ₂ , NR ² , O, S, COO or CONR ² may be replaced and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ , or an aromatic or

heteroaromatic ring system having 5 to 30 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; is identical or different at each occurrence H or an aliphatic, aromatic and / or heteroaromatic organic radical having 1 to 20 C-atoms; is the same or different at each occurrence any group, which reacts with amino groups in one

Condensation or addition reaction connects, preferably a carboxylic acid, a carboxylic acid halide, a

Carboxylic acid anhydride, a carboxylic acid thioester

Carboxylic acid ester, an isocyanate, an isothiocyanate, a chloroformate, a sulfonic acid halide

Sulfinic acid halide, a phosphoric acid halide, a phosphonic acid halide or a phosphinic acid halide; has a value of 1 to 5, where n + m has a value of 3 to 6; m has a value of 1 to 5, wherein n + m has a value of 3 to 6; o has a value of 0 to 6, where o + p has a value of 1 to 6; p has a value of 0 to 6, wherein o + p has a value of 1 to 6; and wherein for at least one of the monomers of the formula (II) it must hold that o + p has a value of 3 to 6.

Membrane according to Claim 7, characterized in that, for the monomer of formula (I), n is equal to 2 and m is 1, so that the compound corresponds to formula (Ia):

Z (NHR ¹ ) ₂ X formula (Ia).

Membrane according to one or more of claims 1 to 8, characterized in that the compound A has two, three or four reactive groups which are connected to the end groups of the

covalently bond hyperbranched polymer, preferably in a condensation or addition reaction.

10. Membrane according to one or more of claims 1 to 9, characterized in that the selectively permeable polymer layer is applied to a carrier layer which consists of polymeric material, wherein the polymeric material is selected from the group comprising polysulfones, polyethersulfones, polyamides, polyethylenes .

Polypropylenes, polyesters, polyacrylonitriles and polyvinylidene fluorides.

11. module for water desalination comprising at least one membrane according to one or more of claims 1 to 10.

12. A process for producing a membrane according to one or more of claims 1 to 10.

A method according to claim 12, characterized in that a) a solution of the hyperbranched polymer is applied to any substrate layer and then

b) those with the solution of the hyperbranched polymer

coated substrate layer with a compound A, which may be in solution, in liquid form or in the gas phase, is brought into contact, wherein the compound A reacts with end groups of the hyperbranched polymer.

Use of a membrane according to one or more of

Claims 1 to 10 or a module according to claim 11 for reducing the content of dissolved ionic compounds water.

Use of a membrane according to one or more of

Claims 1 to 10 or a module according to claim 11 for desalination and / or purification of seawater, brackish water, river water, industrial and domestic wastewater, industrial and domestic water and fresh water.