EP2780393A1

EP2780393A1 - Polymeric material, and the production and use thereof

Info

Publication number: EP2780393A1
Application number: EP12783983.5A
Authority: EP
Inventors: Anna MÜLLER-CRISTADORO; Helmut MÖHWALD; Jelan KUHN
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2011-11-16
Filing date: 2012-11-07
Publication date: 2014-09-24
Also published as: CN103930469A; WO2013072224A1; KR20140089564A; JP2014533750A

Abstract

The present invention relates to a polymeric material that can be obtained by reaction of (A) at least one polyimide, selected from condensation products of (a) at least one polyisocyanate with an average of at least two isocyanate groups per molecule and (b) at least one polycarboxylic acid with at least 3 COOH groups per molecule or the anhydride thereof, (B) at least one diol or triol.

Description

Polymeric material, its manufacture and use

Description The present invention relates to a polymeric material obtainable by reacting

(A) at least one polyimide selected from condensation products of

(A) at least one polyisocyanate having on average at least two isocyanate groups per molecule and

(b) at least one polycarboxylic acid having at least 3 COOH groups per molecule or its anhydride, with

(B) at least one diol or triol.

Furthermore, the present invention relates to the preparation of polymeric materials according to the invention and their use for substance separation, in particular as membranes, for example in membrane separation processes, for example ultrafiltration, nanofiltration, pervaporation, reverse osmosis and gas separation.

For membrane separation processes, for example for ultrafiltration, for nanofiltration, for pervaporation, for reverse osmosis and for gas separation, it is customary to use membranes to which demanding requirements are made. In many cases one uses inorganic membranes or polymeric membranes.

Examples of inorganic membranes include ΤΊΟ2 and ZrO2 membranes, and zeolite membranes. Inorganic membranes, however, often have the disadvantage that they have a certain brittleness and therefore can break under mechanical stress.

In the following, material separation materials are understood as meaning materials which, for example by adsorption-desorption processes or by different permeability properties, permit the separation or enrichment of individual components from mixtures of substances. Examples include membranes and stationary phases for chromatography columns.

In addition to price, materials such as selectivity, permeability and mechanical stability, in particular at high feed pressure, play a particular role for material separation materials. In addition, materials for material separation in organic solvents should swell only slightly.

Recently, it has been proposed many times to use polymers as materials for substance separation. For example, certain polyimides have already been proposed which

Wear trifluoromethyldiphenylidenemethane units, s. For example, WJ Koros et al., J. Membr. Be. 1988, 37, 45; C. Staudt-Bickel et al., J. Membr. Be. 1999, 155, 145, and the literature cited therein. Although the polyimides described in the cited However, separation under technically interesting conditions often leads to strong swelling, which adversely affects the mechanical properties of, for example, membranes. In addition, the proposed materials are cumbersome to produce and therefore priced unfavorable.

US 2010/0038306 describes membrane materials for nanofiltration, which can be obtained by reacting polyimides with diamines. However, diamines remaining in the material are questionable and can only be removed in a complicated way.

It was therefore the task to provide materials that are well suited as materials for material separation and have good mechanical properties, in particular are not brittle, and also show no adverse swelling behavior. Accordingly, the polymeric materials defined above were found. Inventive polymeric materials are obtainable by reacting

(A) at least one polyimide, also called polyimide (A), selected from condensation products of

(A) at least one polyisocyanate having on average at least two isocyanate groups per molecule, short polyisocyanate (a) called, and

(b) at least one polycarboxylic acid having at least 3 COOH groups per molecule, called polycarboxylic acid (b) for short, or its anhydride, abbreviated to anhydride (b), and

(B) at least one diol, hereinafter also called diol (B). Polyimide (A), which is linear or branched and is selected from condensation products of

(A) at least one polyisocyanate having on average more than two isocyanate groups per molecule and

(b) at least one polycarboxylic acid having at least 3 COOH groups per molecule or its anhydride.

Polyimide (A) may have a molecular weight M _w in the range of 500 to 200,000 g / mol, preferably at least 1, 000 g / mol. Polyimide (A) may have at least two imide groups per molecule, preferably at least 3 imide groups per molecule.

In one embodiment of the present invention, polyimide (A) may have up to 1,000 imide groups per molecule, preferably up to 660 per molecule.

In one embodiment of the present invention, the indication of the isocyanate groups or of the COOH groups per molecule in each case denotes the mean value (number average). Polyimide (A) may be composed of structurally and molecularly uniform molecules. However, when polyimide (A) is a mixture of molecularly and structurally different molecules, for example, visible on the polydispersity M _w / M _n of at least 1.4, preferably M _w / M _n of 1.4 to 50, preferably 1, 5 to 10. The polydispersity can be determined by known methods, in particular by gel permeation chromatography (GPC). Suitable standard is, for example, polymethyl methacrylate (PMMA).

In one embodiment of the present invention, in addition to imide groups which form the polymer backbone, polyimide (A) furthermore has at least three, preferably at least six, more preferably at least ten terminal or pendant functional groups, also called branching. Functional groups in polyimide (A) are preferably anhydride or acid groups and / or free or capped NCO groups. Polyimides (A) preferably have not more than 500 terminal or pendant functional groups, preferably not more than 100.

Thus, alkyl groups such as methyl groups are not a branch of a molecule polyimide (A). Polyisocyanate (a) can be selected from any polyisocyanates which have on average at least two isocyanate groups per molecule, which may be capped or preferably free. Preferred polyisocyanates (a) are diisocyanates, for example hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and mixtures of at least two of the aforementioned polyisocyanates (a). Preferred mixtures are mixtures of 4,4'-

Diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate and mixtures of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate.

In another embodiment of the present invention, polyisocyanate (a) is selected from oligomeric hexamethylene diisocyanate, oligomeric tetramethylene diisocyanate, oligomeric isophorone diisocyanate, oligomeric diphenylmethane diisocyanate, trimeric tolylene diisocyanate and mixtures of at least two of the aforementioned polyisocyanates (a). For example, so-called trimeric hexamethylene diisocyanate is in many cases not present as pure trimeric diisocyanate, but as polyisocyanate having an average functionality of 3.6 to 4 NCO groups per molecule. The same applies to oligomeric tetramethylene diisocyanate and oligomeric isophorone diisocyanate.

In one embodiment of the present invention, polyisocyanate (a) is a mixture of at least one diisocyanate and at least one triisocyanate or a polyisocyanate having at least 4 isocyanate groups per molecule. In one embodiment of the present invention, polyisocyanate (a) has on average exactly 2.0 isocyanate groups per molecule. In another embodiment of the present invention, polyisocyanate (a) has on average at least 2.2, preferably at least 2.5, more preferably at least 3.0 isocyanate groups per molecule.

In one embodiment of the present invention, polyisocyanate (a) has on average up to 8, preferably up to 6 isocyanate groups per molecule.

In one embodiment of the present invention, polyisocyanate (a) is selected from oligomeric hexamethylene diisocyanate, oligomeric isophorone diisocyanate, oligomeric diphenylmethane diisocyanate and mixtures of the abovementioned polyisocyanates.

Polyisocyanate (a) may, in addition to urethane groups, also have one or more other functional groups, for example urea, allophanate, biuret, carbodiimide, amide, ester, ether, uretonimine, uretdione, isocyanurate or oxazolidine groups.

As polycarboxylic acids (b) aliphatic or preferably aromatic polycarboxylic acids are selected which have at least three COOH groups per molecule, or the respective anhydrides, preferably if they are present in low molecular weight, ie non-polymeric form. Such polycarboxylic acids having three COOH groups are also included, in which two carboxylic acid groups are present as the anhydride and the third as the free carboxylic acid.

In a preferred embodiment of the present invention, the polycarboxylic acid (b) used is a polycarboxylic acid having at least 4 COOH groups per molecule or the anhydride in question.

Examples of polycarboxylic acids (b) and their anhydrides are 1, 2,3-benzenetricarboxylic acid and

1 .2.3- Benzoltricarbonsäureanhydrid, 1, 3,5-benzenetricarboxylic acid (trimesic acid), preferred

1 .2.4-benzenetricarboxylic acid (trimellitic acid), trimellitic anhydride and in particular 1, 2,4,5-benzenetetracarboxylic acid (pyromellitic acid) and 1, 2,4,5-benzenetetracarboxylic dianhydride (pyromellitic dianhydride), 3,3 ', 4,4'- Benzophenonetetracarboxylic acid, 3, 3 ', 4,4'-benzophenonetetracarboxylic dianhydride, furthermore benzene hexacarboxylic acid (mellitic acid) and anhydrides of mellitic acid. Also suitable are mellophanic acid and mellophanic anhydride, 1,2,3,4-benzenetetracarboxylic acid and 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3,4,4-biphenyltetracarboxylic acid and 3,3,4,4-biphenyltetracarboxylic dianhydride, 2 2,3,3-biphenyltetracarboxylic acid and 2,2,3,3-biphenyltetracarboxylic dianhydride, 1, 4,5,8-naphthalenetetracarboxylic acid and 1,1,5,8-naphthalenetetracarboxylic dianhydride, 1, 2,4,5-naphthalenetetracarboxylic acid and 1, 2,4,5-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid and 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1, 4,5,8-decahydronaphthalenetetracarboxylic acid and 1, 4,5,8- Decahydronaphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1, 2,5,6-tetracarboxylic acid and 4,8-dimethyl-1,2,3,5,6,7- hexahydronaphthalene 1, 2,5,6-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1, 4,5,8-tetracarboxylic acid and 2,6-dichloronaphthalene-1, 4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1 , 4,5,8-tetracarboxylic acid and 2,7-dichloronaphthalene-1, 4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1, 4,5,8-tetracarboxylic acid and 2,3,6 , 7-tetrachloronaphthalene-1, 4,5,8-tetracarboxylic dianhydride, 1, 3,9,10-phenanthrene tetracarboxylic acid and 1,3,9,10-phenanthrene tetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic acid and 3,4,9, 10-perylenetetracarboxylic dianhydride, bis (2,3-dicarboxyphenyl) methane and bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane and bis (3,4-dicarboxyphenyl) methane dianhydride, 1,1-bis (2 , 3-dicarboxyphenyl) ethane and 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1, 1 Bis (3,4-dicarboxyphenyl) ethane and 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane and 2,2-bis (2,3-dicarboxyphenyl ) propane dianhydride, 2,3-bis (3,4-dicarboxyphenyl) propane and 2,3-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-carboxyphenyl) sulfone and bis (3,4-carboxyphenyl) sulfone dianhydride, bis (3,4-carboxyphenyl) ether and bis (3,4-carboxyphenyl) ether dianhydride, ethylene tetracarboxylic acid and ethylene tetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic acid and 1,2,3,4-butanetetracarboxylic dianhydride, 1, 2 , 3,4-cyclopentanetetracarboxylic acid and 1,2,3,4-cyclopentanetracarboxylic dianhydride, 2,3,4,5-pyrrolidinetetracarboxylic acid and 2,3,4,5-pyrrolidinetetracarboxylic dianhydride, 2,3,5,6-pyrazine tetracarboxylic acid and 2, 3,5,6-pyrazine tetracarboxylic dianhydride, 2,3,4,5-thiophenetetracarboxylic acid and 2,3,4,5-thiophenetetracarboxylic dianhydride. In one embodiment of the present invention, anhydrides from US 2,155,687 or US 3,277,117 are used for the synthesis of polyimide (A).

If polyisocyanate (a) and polycarboxylic acid (b) are allowed to condense with one another, preferably in the presence of a catalyst, an imide group is formed with elimination of CO 2 and H 2 O. If, instead of polycarboxylic acid (b), the corresponding anhydride is used, an imide group is formed with elimination of CO 2.

In this case, R ^{* is} the radical of polyisocyanate (a) which is not further specified in the above reaction equation, and n is a number greater than or equal to 1, for example 1 in the case of a tricarboxylic acid or 2 in the case of a tetracarboxylic acid, where (HOOC) _n is an anhydride group of the formula C (= 0) -0-C (= 0) may be replaced.

In one embodiment of the present invention, polyisocyanate (a) is used in admixture with at least one diisocyanate, for example with tolylene diisocyanate, hexamethylene diisocyanate or with isophorone diisocyanate. In a particular variant, polyisocyanate (a) is used in admixture with the corresponding diisocyanate, for example trimeric HDI with hexamethylene diisocyanate or trimeric isophorone diisocyanate with isophorone diisocyanate or polymeric diphenylmethane diisocyanate (polymer MDI) with diphenylmethane diisocyanate.

In one embodiment of the present invention, polycarboxylic acid (b) is used in combination with at least one dicarboxylic acid or with at least one dicarboxylic acid anhydride, for example with phthalic acid or phthalic anhydride.

Diol (B) or triol (B) may be low molecular weight or high molecular weight. Examples of triols (B) are glycerol and 1,1,1- (trihydroxmethylene) methane, 1,1,1- (trihydroxmethylene) ethane and 1,1,1- (trihydroxmethylene) propane.

Diols (B) are preferred.

As low molecular weight diols (B), in the context of the present invention, those having a molecular weight of up to 500 g / mol are to be mentioned by way of example: 1, 2-ethanediol, 1, 2-propanediol, 1, 3-propanediol, 1, 2 Butanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 4-but-2-endiol, 1, 4-but-2-indiol, 1, 5-pentanediol and its position isomers, 1, 6-hexanediol, 1,8-octanediol, 1,4-bishydroxymethylcyclohexane, 2,2-bis (4-hydroxycyclohexyl) propane, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, tetraethylene glycol and especially 2,2-dimethylpropane-1, 3-diol (neopentyl glycol). As polymeric diols there may be mentioned dihydric or polyhydric polyester polyols and polyether polyols, the divalent ones being preferred. Preferred polyetherpolyols are polyetherdiols, such as boron trifluoride-catalyzed linking of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with themselves or with one another or by addition of these compounds, singly or in admixture, to starter components having reactive Hydrogen atoms such as water, polyhydric alcohols or amines such as 1, 2-ethanediol, propanediol (1, 3), 1, 2 or 2,2-bis (4-hydroxyphenyl) propane or aniline are available. Furthermore, polyether-1, 3-diols, for example, the trimethylolpropane alkoxylated on an OH group whose alkylene oxide chain is terminated with an alkyl radical containing 1 to 18 C atoms, are preferably used polymeric diols.

Preferred polymeric diols are: polyethylene glycol, polypropylene glycol and in particular polytetrahydrofuran (poly-THF).

Particular preference is given to polyether polyols selected from: polyethylene glycol having an average molecular weight (M _n ) in the range from 200 to 9,000 g / mol, preferably in the range from 500 to 6,000 g / mol, poly-1,2-propylene glycol or poly-1,3 propanediol having an average molecular weight (M _n ) in the range from 250 to 6,000, preferably 600 to 4,000 g / mol, poly-THF having an average molecular weight (M _n ) in the range from above 250 to 5,000, preferably from 500 to 3,000 g / mol, more preferably in the range of 750 to 2,500 g / mol.

Other preferred polymeric diols are polyester polyols (polyester diols) and polycarbonate diols.

Particularly suitable polycarbonate diols are aliphatic polycarbonate diols, for example 1,4-butanediol polycarbonate and 1,6-hexanediol polycarbonate.

As the polyester diols are those mentioned by polycondensation of at least one primary diol, preferably at least one primary aliphatic diol, for example ethylene glycol, 1, 4-butanediol, 1, 6-hexanediol, neopentyl glycol or more preferably 1, 4-dihydroxymethylcyclohexane (as Mixture of isomers) or mixtures of at least two of the aforementioned diols on the one hand and at least one, preferably at least two dicarboxylic acids or their anhydrides on the other hand. Preferred dicarboxylic acids are aliphatic dicarboxylic acids such as adipic acid, glutaric acid, succinic acid and aromatic dicarboxylic acids such as phthalic acid and in particular isophthalic acid.

In one embodiment of the present invention, polyester diols and polycarbonate diols are selected from those having an average molecular weight (M _n ) in the range of 500 to 9,000 g / mol, preferably in the range of 500 to 6,000 g / mol. Very particularly preferred diols (B) are polytetrahydrofurans, for example having an average molecular weight M _n in the range from 250 to 2,000 g / mol.

In one embodiment of the present invention, the polymeric material according to the invention has an acid number in the range from zero to 300 mg KOH / g, determined according to DIN 53402, preferably from zero to 200 mg KOH / g.

In one embodiment of the present invention, the polymeric material according to the invention has a hydroxyl number in the range from zero to 300 mg KOH / g, determined according to DIN 53240-2, preferably from zero to 200 mg KOH / g.

In one embodiment of the present invention, polymeric material according to the invention has a quotient M _w / M _n in the range from 1.2 to 10, preferably from 1.5 to 5, more preferably from 1.8 to 4. Here, M _w and M are determined _n preferably by gel permeation chromatography.

Another object of the present invention is the use of polymeric materials according to the invention as or for the production of materials for the separation of substances, for example as or for the preparation of stationary phases for chromatography, preferably as or for the production of membranes. Another object of the present invention is a process for the preparation of materials for material separation, in particular for the production of stationary phases for chromatography or membranes, using at least one material according to the invention. Another object of the present invention are materials for separation, for example, stationary phases for chromatography and in particular membranes, prepared using at least one polymeric material according to the invention.

Membranes of the invention may have an average thickness in the range of 0.01 to 100 μm, preferably 1 to 50 μm, particularly preferably 1 to 20 μm.

Membranes according to the invention can be formed as hollow-fiber membranes or flat membranes. Specific examples of flat membranes are wound membranes.

Membranes according to the invention are suitable for membrane separation processes, in particular for nanofiltration, gas separation, pervaporation, reverse osmosis, microfiltration and ultrafiltration, in particular nanofiltration and ultrafiltration with substances dissolved in organic solvents.

In the context of the present invention, nanofiltration means a membrane separation process in which the membrane used in the case of non-porous membranes has a molecular weight cut-off (MWCO) of 100 to 1500 g / mol or in variants of porous membranes a maximum pore diameter of 1 nm. With the aid of nanofiltration, for example, substances can be separated which have an average molecular weight of less than 0.1 or less than 1.5 kg / mol, that is to say less than 100 or less than 1500 g / mol. For the purposes of the present invention, ultrafiltration is understood as meaning a membrane separation process in which the membrane has a separation limit in the range from 1, 500 to 1, 000 000 g / mol, or separates particles which have a maximum diameter in the range from 10 to 500 nm. In the context of the present invention, microfiltration is understood as meaning a membrane separation process in which the membrane has a separation limit above 1 000 000 g / mol, or has a pore diameter of 1 μm to 10 μm.

In order to produce membranes of polymeric material according to the invention, it is possible, for example, to crosslink a polymeric material according to the invention with a precisely calculated amount of a crosslinker, for example a diisocyanate or polyisocyanate, on a solid surface. As polyisocyanates one can choose those mentioned under polyisocyanate (a). The amount of crosslinker can be calculated, for example, on the basis of the OH number or acid number of polymeric material according to the invention on the one hand and the number of functional groups, for example NCO groups, of crosslinker on the other hand.

In a further embodiment of the present invention, membranes according to the invention are produced by reacting a solution comprising at least one organic solvent, at least one crosslinker and at least one polymeric material according to the invention, in the form of a film, onto an article having a smooth surface, for example a plastic plate or on a glass plate, applies. Thereafter, the solvent or solvents are evaporated and treated thermally, for example in a range from 20 ° C to 400 ° C, preferably from 40 to 200 ° C, more preferably from 50 to 150 ° C. In this case, a crosslinking reaction takes place in situ. The desired crosslinking can be accelerated by adding a catalyst. Finally, according to the invention, after the thermal treatment, the membrane can be easily removed from the smooth-surfaced article.

In one embodiment of the present invention, the membrane according to the invention is combined with a further layer, preferably with a silicone layer, for example by lamination.

In another embodiment, membranes of the invention can be spun as hollow fiber membranes. Such membranes of the invention are particularly well suited for gas separation, but also as protective layers. Membranes according to the invention can be embodied as integral asymmetric or composite membranes in which the actual separation layer effecting the separation and having a thickness of 0.01 to 100 μm, preferably 0.1 to 20 μm, is deposited on one or more meso membranes. and / or macroporous carrier (s) which consists of one or more organic, in particular polymeric and / or inorganic, material (s), for example ceramic, carbon, metal.

Membranes according to the invention can be used in the form of flat, cushion, capillary, hollow fiber, mono-channel pipe or multi-channel pipe elements. The geometries are known to the person skilled in the art from other membrane separation processes such as ultrafiltration or reverse osmosis (see, for example, R. Rautenbach "Membrane Process, Fundamentals of Module and Plant Design", Springer Verlag, 1997.) For membrane elements with tube geometry, the separating layer can be on the inside In a further embodiment of the present invention, membranes according to the invention are surrounded by one or more housings of polymeric, metallic or ceramic material, the connection between the housing and the membrane being made by a sealing polymer (eg elastomer) or by an inorganic material Another object of the present invention is a process for the separation of mixtures using polymeric material according to the invention, for example in the form of membranes according to the invention or of stationary phases according to the invention for chromatography Appropriate methods for the separation of mixtures using material for material separation according to the invention are also called separation method according to the invention below.

Material separation materials according to the invention, for example membranes according to the invention or chromatography columns according to the invention, are suitable e.g. for the following separation tasks, i. for the separation of the following mixtures:

Polyalkylene glycols of various molecular weights, for example polyethylene glycol / polypropylene glycol block copolymer 6,500 g / mol - polyethylene glycol 400 g / mol

Separation of Homogeneous or Heterogeneous Catalysts from Organic Solvents Monomer / Dimer Separation

Discoloration of organic solutions

desalination

Membranes according to the invention in many cases show no permeability to water, even after conditioning in THF. By contrast, membranes according to the invention show a good permeability to organic solvents, for example acetone, toluene, isopropanol and ethanol. Membranes of the invention are flexible and easy to cut. In many cases membranes of the invention are thermally stable, for example up to a temperature of 200 ° C. A further subject of the present invention is a process for the preparation of polymeric materials according to the invention, also referred to in short as the production process according to the invention. To carry out the preparation process according to the invention, it is possible to proceed in such a way that a polyimide (A) obtainable by condensation of

(b) at least one polycarboxylic acid having at least 3 COOH groups per molecule or its anhydride

implemented with

(B) at least one diol.

Preferably, polyimide (A) has a polydispersity M _w / M _n of at least 1.4.

Polyimide (A), polyisocyanate (a), polycarboxylic acid (b), anhydride (b) and diol (B) are described above. The production process according to the invention is a two-stage process. It is possible after the production of polyimide (A) to isolate this and purify. In another variant, the preparation process according to the invention is carried out as a one-pot process and omits the purification and isolation of polyimide (A). To carry out the synthesis process according to the invention, it is possible to use polyisocyanate (a) and polycarboxylic acid (b) or anhydride (b) in an amount such that the molar fraction of NCO groups to COOH groups is in the range from 1: 3 to 3: 1 , preferred are 1: 2 to 2: 1. In this case, an anhydride group of the formula CO-O-CO counts as two COOH groups.

In one embodiment of the present invention, polyimide (A) and diol (B) are used in proportions such that the molar ratio of hydroxyl groups of diol (B) is related to the sum of NCO groups and COOH groups such as 1:10 to 10 : 1, preferably 1: 6 to 6: 1, more preferably 1: 4 to 4: 1.

In one embodiment of the present invention, it is possible to use in the range from 0.005 to 0.1% by weight of catalyst, based on the sum of polyisocyanate (a) and polycarboxylic acid (b) or polyisocyanate (a) and anhydride (b). Preference is given to 0.01 to 0.05 wt .-% catalyst. In one embodiment of the present invention, the synthesis process according to the invention can be carried out at temperatures in the range from 50 to 140.degree. C., preferably from 50 to 100.degree. In one embodiment of the present invention, the production process according to the invention can be carried out under atmospheric pressure. But the synthesis under pressure, for example at pressures in the range of 1, 1 to 10 bar, is possible.

In one embodiment of the present invention, the synthesis process according to the invention can be carried out in the presence of a solvent or solvent mixture. Examples of suitable solvents are N-methylpyrrolidone, N-ethylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dimethyl sulfone, xylene, phenol, cresol, ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), acetophenone, furthermore mono- and dichlorobenzene, ethylene glycol monoethyl ether acetate, and mixtures of two or more of the abovementioned solvents. In this case, the solvent or solvents may be present during the entire duration of the synthesis or only during part of the synthesis.

You can, for example, over a period of 10 minutes to 24 hours to implement.

In a variant of the synthesis process according to the invention, it is possible to block NCO end groups of polyimide (A) with a secondary amine, for example with dimethylamine, di-n-butylamine or with diethylamine. In one embodiment of the present invention, the preparation process according to the invention is carried out without addition of a catalyst.

In another embodiment of the present invention, the production process according to the invention is carried out with the aid of a catalyst, for example by admixing at least one catalyst customary in polyurethane chemistry.

Particularly suitable catalysts are water and Brønsted bases, for example alkali metal alkoxides, in particular alkoxides of sodium or potassium, for example sodium methoxide, sodium ethoxide, sodium phenolate, potassium methoxide, potassium ethanolate, potassium phenolate, lithium methoxide, lithium ethanolate and lithium phenolate.

Further suitable catalysts are tertiary amines, amidines and / or organic metal compounds. Examples are 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine, N-methyl-, N-ethyl-, N-cyclohexylmorpholine, Ν, Ν, Ν ', Ν'-tetramethylethylenediamine, Ν, Ν, Ν ', Ν'-tetramethyl-butanediamine, Ν, Ν, Ν', Ν'-tetramethyl hexanediamine, pentamethyldiethylenetriamine, tetramethyldiaminoethyl ether, bis (dimethylaminopropyl) urea, dimethylpiperazine, 1, 2-dimethylimidazole, 1-azabicyclo- (3,3,0) -octane and preferably 1,4-diazabicyclo - (2,2,2) -octane and alkanolamine compounds, such as triethanolamine, triisopropanolamine, N-methyl and N-ethyl-diethanolamine and Dimethyletha- nolamin used. Also suitable as catalysts are metal compounds, preferably tin compounds such as tin (II) salts of organic carboxylic acids, for example tin (II) acetate, tin (II) octoate, tin (II) ethylhexoate and tin ( II) -laurate and preferably organo-tin compounds, particularly preferably dialkyltin (IV) salts of organic carboxylic acids, in particular, in particular, di-n-C 1 -C 10 -alkyl-tin-alkanoates, eg. Di-n-butyl-tin diacetate, di-n-butyltin dilaurate, di-n-butyltin maleate and di-n-octyltin diacetate, and bismuth carboxylates such as bismuth (III) neodecanoate, bismuth 2-ethylhexanoate and bismuth octanoate or mixtures thereof. Metal compounds or organometallic compounds can be used alone or in combination with basic amines. Another preferred catalyst used is di-n-butyltin mercaptide or di-n-butyltin dioctanoate.

In a preferred embodiment of the present invention, the synthesis process according to the invention is carried out under inert gas, for example under argon or under nitrogen.

When using water-sensitive Brønsted base as a catalyst, it is preferred to dry inert gas and solvent. If you use water as a catalyst, you can do without the drying of solvent and inert gas.

By the production process according to the invention is obtained - optionally after workup, for example after removal of solvent - inventive polymeric material. The invention will be explained by working examples. General remarks:

Polyisocyanate (a.1): 4,4'-diphenylmethane diisocyanate

Anhydride (b.1): 1, 2,4,5-benzene tetracarboxylic dianhydride

The molecular weights were determined by gel permeation chromatography (GPC). The standard was polystyrene (PS). The solvent used was tetrahydrofuran (THF), unless expressly stated otherwise. Detection was carried out with a differential refractometer Agilent 1 100, or a UV photometer Agilent 1 100 VWD.

The NCO content was determined by titrimetry according to DIN EN ISO 1 909 and stated in% by weight. The syntheses were carried out under nitrogen unless otherwise described.

Synthesis Examples:

I. Preparation of Polymeric Materials According to the Invention

1.1 Synthesis of Polymeric Material (PM.1) According to the Invention

In a 4-liter four-necked flask equipped with dropping funnel, reflux condenser, internal thermometer and Teflon stirrer 100 g (0.46 mol) of anhydride (b.1), dissolved in 1400 ml of acetone, which was not dried before the reaction and therefore Contained water. 173 g (0.69 mol) of polyisocyanate (a.1) were then added dropwise at 20 ° C. to 173 g. The mixture was heated with stirring to 55 ° C. The mixture was stirred for a further six hours at 55 ° C under reflux. Thereafter, 600 g of poly-THF having an average molecular weight M _n of 1,000 g / mol (0.6 mol) were added. The temperature was raised to 60 ° C and distilled acetone within 4 hours at atmospheric pressure. It was then heated to 125 ° C and lowered the pressure to 200 mbar. Thereafter, the residue in the flask was stripped with nitrogen. Polymeric material (PM.1) according to the invention was obtained as a solid yellow mass.

M _n = 8360 g / mol, M _w = 21000 g / mol OH number: 22 mg KOH / g

Acid value: 88 mg KOH / g

1.2 Synthesis of Inventive Polymeric Material (PM.2) 100 g (0.46 mol) of anhydride (b.1), dissolved in 1400 ml, were placed in a 4 l four-necked flask with dropping funnel, reflux condenser, internal thermometer and Teflon stirrer Acetone which was not dried before the reaction and therefore contained water. Then, at 20 ° C., 1 15 g (0.46 mol) of polyisocyanate (a.1) were added dropwise. The mixture was heated with stirring to 55 ° C. The mixture was stirred for a further six hours at 55 ° C under reflux. Thereafter, 1000 g of poly-THF having an average molecular weight M _n of 1,000 g / mol (1.0 mol) was added and stirred under reflux at 55 ° C for 14 hours. The temperature was raised to 60 ° C and distilled acetone within 4 hours at atmospheric pressure. It was then heated to 125 ° C and lowered the pressure to 200 mbar. Thereafter, the residue in the flask was stripped with nitrogen. Inventive polymeric material (PM.2) was obtained as a solid yellow mass.

M _n = 7.250 g / mol, M _w = 16,900 g / mol OH number: 26 mg KOH / g

Acid value: 40 mg KOH / g

1.3 Synthesis of Polymeric Material According to the Invention (PM.3) In a 4-liter four-necked flask equipped with dropping funnel, reflux condenser, internal thermometer and Teflon stirrer 100 g (0.46 mol) of anhydride (b.1), dissolved in 1400 ml of acetone, before which was not dried before the reaction and therefore contained water. Then 15 g (0.69 mol) of polyisocyanate (a.1) were added dropwise at 20 ° C. The mixture was heated with stirring to 55 ° C. The mixture was stirred for a further six hours at 55 ° C under reflux. Thereafter, 300 g of poly-THF having an average molecular weight M _n of 1,000 g / mol (0.3 mol) was added. The mixture was stirred for a further six hours under reflux at 55 ° C and then increased the temperature to 60 ° C and thereby distilled acetone within 4 hours at atmospheric pressure. It was then heated to 125 ° C and lowered the pressure to 200 mbar. Thereafter, the residue in the flask was stripped with nitrogen. Inventive polymeric material (PM.3) was obtained as a solid yellow mass.

M _n = 3670 g / mol, M _w = 1 1 .900 g / mol OH number: 37 mg KOH / g

Acid value: 144 mg KOH / g

1.4 Synthesis of Inventive Polymeric Material (PM.4) 100 g of anhydride (b.1) (0.46 mol), dissolved in 1400 ml, were placed in a 4 l four-necked flask with dropping funnel, reflux condenser, internal thermometer and Teflon stirrer Acetone, which was not dried before the reaction and therefore contained water. 173 g (0.69 mol) of polyisocyanate (a.1) were then added dropwise at 20 ° C. to 173 g. The mixture was heated with stirring to 55 ° C. The mixture was stirred for a further five hours at 55 ° C under reflux. Thereafter, 390 g of poly-THF having an average molecular weight M _n of 650 g / mol (0.6 mol) were added. The temperature was raised to 60 ° C and distilled acetone within 7 hours at atmospheric pressure. It was then heated to 80 ° C and lowered the pressure to 200 mbar. Thereafter, the residue in the flask was stripped with nitrogen. Inventive polymeric material (PM.4) was obtained as a solid yellow mass.

M _n = 5900 g / mol, M _w = 14000 g / mol OH number: 14 mg KOH / g

Acid number: 107 mg KOH / g

1.5 Synthesis of Polymeric Material According to the Invention (PM.5)

In a 4-liter four-necked flask equipped with dropping funnel, reflux condenser, internal thermometer and Teflon stirrer 100 g (0.46 mol) of anhydride (b.1), dissolved in 1400 ml of acetone, before which was not dried before the reaction and therefore contained water. 173 g (0.69 mol) of polyisocyanate (a.1) were then added dropwise at 20 ° C. to 173 g. The mixture was heated with stirring to 55 ° C. The mixture was stirred for a further five hours at 55 ° C under reflux. Thereafter, 173 g of poly THF were added with an average molecular weight M _n of 250 g / mol (0.6 mol). The temperature was raised to 60 ° C and distilled acetone within 7 hours at atmospheric pressure. It was then heated to 80 ° C and lowered the pressure to 200 mbar. Thereafter, the residue in the flask was stripped with nitrogen. Polymeric material (PM.5) according to the invention was obtained as a solid yellow mass.

M _n = 4360 g / mol, M _w = 8370 g / mol

OH number: 12 mg KOH / g

Acid value: 151 mg KOH / g

II. Preparation of a Membrane According to the Invention from (PM.1) or (PM.3), General Method A polymeric material according to the invention was weighed in a beaker according to Table 1 and 1, 3-dioxolane was added as solvent. The mixture was stirred with a magnetic stirrer over a period of 30 minutes to obtain a transparent solution. Next, crosslinker (CL.1) according to Table 1 was added and stirring was continued for 5 minutes. Thereafter, a membrane was prepared with a laboratory blade. For this purpose, a doctor table (Erichsen, Coatmaster 509 MC-1) was set to 80 ° C and poured the solution described above on a glass plate with a wet film thickness of 100 μηη. Then, from the solution, a film was drawn on a glass plate having a wet film thickness of 100 μm. The wet film was allowed to air-dry for 15 minutes and then placed in a water bath at room temperature for 24 hours. It was then dried for 24 hours in a vacuum drying oven at 80.degree. This gave membranes according to the invention.

Crosslinkers used: (CL.1): Polymeric 4,4'-diphenylmethane diisocyanate with functionality of 2.7, NCO: 31, 5%

Table 1: Experimental details for the preparation of materials according to the invention

The MWCO of the membranes MEMB.1 or MEMB.3 according to the invention was about 6.5 kg / mol, determined by determining the retention of a 10% by weight solution of polyethylene glycol (M _w 400 g / mol) and a polyethylene glycol / polypropylene glycol Block copolymer (with M _w = 6500 g / mol) in THF.

Claims

claims

Polymeric material obtainable by reaction of

(A) at least one polyimide selected from condensation products of

(B) at least one diol or triol.

Polymeric material according to Claim 1, characterized in that polyimide (A) is selected from those polyimides which have a molecular weight M _w of at least 1 000 g / mol.

Polymeric material according to claim 1 or 2, characterized in that one selects as polycarboxylic acid (b) a polycarboxylic acid having at least 4 COOH groups per molecule or the respective anhydride.

A polymeric material according to any one of claims 1 to 3, characterized in that the polyisocyanate (a) selects hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, 4,4 ^{'diphenylmethane} diisocyanate, ^{2,4'-diphenylmethane} diisocyanate, tolylene diisocyanate and mixtures of at least two of the aforementioned Polyisocyanates (a).

Polymeric material according to one of Claims 1 to 3, characterized in that polyisocyanate (a) is selected from oligomeric hexamethylene diisocyanate, oligomeric tetramethylene diisocyanate, oligomeric isophorone diisocyanate, oligomeric diphenylmethane diisocyanate, trimeric tolylene diisocyanate and mixtures of at least two of the abovementioned polyisocyanates (a).

Polymeric material according to one of claims 1 to 5, characterized in that one selects diol (B) from diols having a molecular weight M _w in the range of 250 to 5,000 g / mol.

Polymeric material according to one of Claims 1 to 6, characterized in that diol (B) is selected from polyethylene glycols, polypropylene glycols, polyester diols, polycarbonate diols and polytetrahydrofuran.

Polymeric material according to any one of claims 1 to 7, characterized in that it has an acid value in the range of zero to 300 mg KOH / g.

9. Polymeric material according to one of claims 1 to 8, characterized in that it has a hydroxyl number in the range of zero to 300 mg KOH / g.

10. Use of polymeric material according to any one of claims 1 to 9 as or for the production of membranes.

1 1. A process for producing membranes using at least one polymeric material according to any one of claims 1 to 9. 12. Membrane containing or prepared using at least one polymeric material according to any one of claims 1 to 9.

13. Use of membranes according to claim 12 in membrane separation processes. 14. Use of polymeric materials according to any one of claims 1 to 9 as a stationary phase in the chromatography.

15. A process for the preparation of polymeric materials according to any one of claims 1 to 9, characterized in that one obtains a polyimide (A), obtainable by condensation of

implemented with

(B) at least one diol or triol.

Process according to Claim 15, characterized in that polyimide (A) is reacted with diol (B) with the aid of a catalyst.

A method according to claim 16, characterized in that one selects the catalyst from di-n-Ci-Cio-alkyl-tin alkanoates.