[0001] The invention relates to a solvent composition (s) and its use for stabilizing polymeric solutions, said solutions being used in particular polymer for the manufacture of films, membranes, artificial leathers, polymeric suede, polymeric fibers, coatings, electronic circuits, batteries, in particular lithium-ion (Li-ion), or for the protection of electric cables with sheathing. The invention also relates to a polymer solution (s) and a filtration membrane obtained from the polymer solution (s).

TECHNICAL BACKGROUND

[0002] The polymeric films or polymeric hollow fibers may be used in various applications such as coating textiles, including artificial leathers, suede shoes or personal protective equipment; batteries, including Li-ion batteries; membranes, particularly for the treatment of water or dialysis; the protection of electrical cables with sheathing; electronic circuits.

[0003] Among the polymers that can be used in these applications include polyurethanes (PU), polysulfones (PSU), polyvinylidene fluorides (PVDF), polyethersulfones (PES), polyphenyl sulphones (PPSU) cellulose acetate, polyamide-imide (PAI) and polyimides (PI), this list is not exhaustive.

[0004] The manufacturing processes of these films or polymer fibers include many steps, among which are:

- Synthesis of the polymer in solvent medium,

- dissolving the polymer in a solvent in the case where the polymer resulting from the synthesis is introduced in solid form (e.g. in extruded form or balls) to obtain a polymeric solution, - production of a film by a method coating the polymer solution followed by drying (heat treatment: dry process) to evaporate the solvent,

This step can also be replaced by a step of:

- production of a film or a hollow fiber through an impregnation process of a support or spinning the polymer solution followed by quenching in a third solvent (eg water) to precipitate the polymer and to migrate the solvent of the polymeric solution to the solubilizer (coagulation: wet process).

[0005] The method may further comprise:

- optionally recycling the solvent,

- possibly sending aqueous solutions generated in wastewater treatment plants.

[0006] Currently, the solvents commonly used for the manufacture of such films or polymer hollow fibers are polar aprotic solvents such as NMP (N-methylpyrrolidone), DMF (dimethylformamide) and DMAc (dimethylacetamide). These solvents nevertheless present numerous toxicological drawbacks because they are classified as CMR (carcinogenic, mutagenic, toxic for reproduction) and toxic.

[0007] There is therefore an interest in substituting these solvents with solvents having a better toxicological profile.

[0008] Alternatives to these toxic solvents have been proposed.

[0009] WO 2005/090447 proposes substituting NMP with N-ethyl-2-pyrrolidone (NEP). The NEP is now classified reprotoxic by the European Union.

[0010] In WO 2008/012231, it is proposed to replace NMP with the 1, 5-dimethylpyrrolidone (DMP). reproductive toxicity studies have indicated that the DMP is suspected to be toxic to reproduction as well as NMP.

[0011] More recently, WO 2013/107822 proposes to substitute partially or totally toxic solvents such as NMP, DMF or dMACS by a solvent selected from N-butylpyrrolidone, N-isobutylpyrrolidone, Nt-butylpyrrolidone, Nn -pentylpyrrolidone, N- (substituted-methyl butyl) pyrrolidone, N-propyl or N-butyl pyrrolidone, nucleus-substituted or methyl-N- (methoxypropyl) pyrrolidone.

[0012] It has also been proposed to use dimethyl sulfoxide (DMSO) as a solvent for the manufacture of films or hollow polymer fibers.

[0013] The use of DMSO and 2-pyrrolidone alone pose polymeric solutions stability problems, which makes it a very difficult industrial process or impossible to implement without significant adaptation process. DMSO or 2-pyrrolidone are used to dissolve the polymers, such as polyurethanes or polysulfones heating these solutions to about 50 ° C for several hours, but the polymeric solutions obtained gel or solidify quickly after returning to the working temperature of the order of 0 to 20 ° C.

[0014] There are no solvents to compositions of day, unclassified CMR, allowing both to dissolve the polymers and to obtain stable polymeric solutions, particularly at low temperature (temperature in the range of 0 C., for example) over a period ranging from a few days up to several weeks (3 weeks for example). Indeed, for an industrial solution, it is necessary that the polymer solutions are stable and do not gel for a few hours or even weeks thereby overcoming the hazards of industrial production (stop unit, workshops heating problem , etc.), and storage problems, and at temperatures up to 0 ° C for example.

[0015] The document JP126681 1 provides a hollow fiber membrane obtained by mixing a polyether sulfone, DMSO, 2-pyrrolidone and an average molecular weight of polyethylene glycol 200 (PEG 200). This document teaches that 2-pyrrolidone increases the permeability of the hollow fiber membrane and the mechanical strength. 2-pyrrolidone, as well as Poly Ethylene Glycol (PEG) or polyvinylpyrrolidone (PVP), thus serves to improve the permeation of the membrane. It is known that the addition of blowing agents can change the pore structure of membranes and thus permeation. These include for example the article Desalination 207

(2007), 324-339 "Synthesis, characterization and performance of asymmetric polyethersulfone (PES) ultrafiltration membranes with polyethylene glycol of different molecular weights as additives" and Article Physics and Chemistry of the Earth 67-69 (2014), 125 -131 "Preparation of antifouling polyvinylpyr-pyrrolidone modified polyethersulfone ultrafiltration membrane for water purification". The JP126681 Document 1 does not mention the problem of the stability of polymeric solutions and does not describe the solvent composition (s) according to the present invention.

SUMMARY OF THE INVENTION

[0016] The invention firstly relates to a solvent composition (s) comprising a mixture of at least one molecule having at least a sulfoxide function and at least one molecule having at least one amide function wherein the atom nitrogen carries a hydrogen atom (-NH-C (O) -), said composition being substantially free of polyether. By "substantially free of polyether" is meant that the composition may contain one or more polyether in an amount less than 1% by weight, preferably less than 0.5% by weight, based on the total weight of the composition.

[0017] According to a particular embodiment, the solvent composition (s) according to the invention is substantially free of polymers. By "substantially free of polymers" means that said solvent composition (s) may contain one or more polymers in an amount less than 1% by weight, preferably less than 0.5% by weight, relative to the total weight of the composition.

[0018] According to a preferred embodiment, the molecule carrying the amide function is cyclic. Preferably, the molecule carrying an amide functional group is 2-pyrrolidone. Preferably, the molecule carrying an amide functional group is not the epsilon-caprolactam

[0019] According to a preferred embodiment, the molecule carrying a sulphoxide function is dimethylsulfoxide.

[0020] According to one embodiment, the solvent composition (s) according to the invention comprises dimethyl sulfoxide and 2-pyrrolidone.

[0021] According to one embodiment, the solvent composition (s) according to the invention comprises:

- from 21 to 75% by weight, preferably 25 to 70% by weight, more preferably from 30 to 65% by weight of the molecule carrying a sulphoxide function,

- from 25 to 80% by weight, preferably 30 to 75% by weight, more preferably from 35 to 70% by weight of the molecule bearing an amide wherein the nitrogen atom carries a hydrogen atom,

based on the total weight of the composition.

[0022] According to one embodiment, the composition according to the invention further comprises at least one other co-solvent, preferably selected from water, ketones, amines, alcohols, ethers, esters, sulfones, aromatics, acetals or from N-butylpyrrolidone, N-isobutylpyrrolidone, Nt-butylpyrrolidone, Nn-pentylpyrrolidone, N- (substituted-methyl butyl) pyrrolidone, N-propyl or N-butyl pyrrolidone, nucleus-substituted or methyl-N- (methoxypropyl) pyrrolidone, dipropylene glycol dimethyl ether (DPGDME), the polyglyme, ethyl diglyme, 1, 3-dioxolane, methyl-5 (dimethylamino) -2 -methyl-5-oxopentanoate.

[0023] The invention also relates to the use of the solvent composition (s) according to the invention for improving the stability of polymer solutions.

[0024] Preferably, polymer solutions are solutions of polymers having sulfone or urethane functions.

[0025] Preferably, the polymer solution is a solution of polysulfone or polyethersulfone or polyphenylsulfone, preferably a polysulfone solution.

[0026] The invention also relates to a polymer solution (s), said solution comprising a solvent composition (s) comprising a mixture of at least one molecule having at least a sulfoxide function and at least one molecule having at least one amide function wherein the nitrogen atom carries a hydrogen atom (-NH-C (O) -), said polymer solution being substantially free of polyether. By "substantially free of polyether" is meant that said polymer solution (s) may contain one or more polyether in an amount less than 1% by weight, preferably less than 0.5% by weight, relative to the total weight of said solution.

[0027] Preferably, the polymer of the polymer solution (s) has sulfone or urethane functions.

[0028] According to a preferred embodiment, the polymer solution comprises a solvent composition (s) as defined in the present invention.

[0029] According to one embodiment, the polymer solution comprises:

- from 5 to 50% by weight, preferably 8 to 35% by weight of polymers, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the polymer solution.

[0030] The invention also relates to a filtration membrane obtained from the polymer solution of the invention.

[0031] The invention also relates to an artificial leather obtained from the polymer solution of the invention.

[0032] The invention also relates to the use of the polymer solution according to the invention for the manufacture of films, artificial leather, suede polymer, polymeric fibers, coating, membranes, batteries, electronic circuits, or for the protection of electrical cables.

[0033] The solvent composition (s) according to the present invention helps to stabilize the polymer solutions, and this in a wide range of temperature, especially at low temperatures. The present invention allows to provide a single solvent composition (s) having a universal character and for stabilizing a wide variety of polymers, namely both polyurethanes, polyethersulfones and polysulfones.

[0034] The polymer solutions according to the present invention are stable at room temperature and / or low-temperature, and over a period of up to several weeks.

[0035] The one or more solvent (s) used are not or only slightly toxic. In particular, the solvent (s) used are not classified as CMR.

EMBODIMENTS DESCRIPTION OF THE INVENTION

[0036] The invention is now described in more detail and not limited to the following description.

[0037] The present invention provides a solvent composition (s) comprising a mixture of at least one molecule having at least a sulfoxide function and at least one molecule having at least an amide wherein the nitrogen atom carries a hydrogen atom (-NH-C (O) -), said composition being substantially free of polyether, preferably completely free of polyethersulfones. Both molecules (that carrying the sulphoxide function and that carrying the amide function) are distinct from each other.

[0038] The molecule carrying the sulfoxide function may for example comprise from 2 to 24 carbon atoms, preferably from 2 to 12 carbon atoms, preferably from 2 to 6 carbon atoms.

[0039] The molecule carrying the amide function may for example comprise from 2 to 24 carbon atoms, preferably from 2 to 12 carbon atoms, preferably from 2 to 6 carbon atoms, preferably from 2 to 5, so most preferably 2, 3 or 4 carbon atoms.

[0040] Preferably, the molecule having at least a sulphoxide function have one sulphoxide function.

[0041] Preferably, the molecule having at least one amide function present one amide function.

[0042] According to one embodiment of the invention, the solvent composition (s) consists essentially of, and preferably exclusively, in molecules bearing a sulphoxide function and molecules bearing an amide wherein the nitrogen atom carries a hydrogen atom (-NH-C (O) -).

[0043] According to one embodiment, the solvent composition (s) according to the invention is substantially free of polymers, preferably completely free of polymers, particularly of polyether type polymers.

[0044] The term "polymers" in the sense of this invention means any molecule having at least two units (monomers) identical connected by a covalent bond. The polymer according to the present invention may be of natural or synthetic origin, obtainable by polymerization, polycondensation or polyaddition.

[0045] Preferably, the molecule having at least one amide functional group is cyclic, in particular, the amide is a cyclic amide. More preferably, the molecule having at least one amide is 2-pyrrolidone.

[0046] Preferably, the molecule carrying a sulphoxide function is dimethylsulfoxide (DMSO).

[0047] According to a particular embodiment, the solvent composition (s) comprises DMSO and 2-pyrrolidone. According to one embodiment, the solvent composition (s) according to the invention consists essentially, and preferably exclusively, in DMSO and 2-pyrrolidone.

[0048] Preferably, the solvent composition (s) according to the invention comprises:

- from 21 to 75% by weight, preferably 25 to 70% by weight, more preferably from 30 to 65% by weight of molecule (s) carrying a sulphoxide function,

- 25 to 79% by weight, preferably 30 to 75% by weight, more preferably from 35 to 70% by weight of molecule (s) bearing an amide wherein the nitrogen atom carries a hydrogen atom, hydrogen,

based on the total weight of the solvent composition (s).

[0049] According to one embodiment, the solvent composition (s) consists essentially of, and preferably exclusively, in:

- from 21 to 75% by weight, preferably 25 to 70% by weight, more preferably from 30 to 65% by weight of molecule (s) carrying a sulphoxide function,

- 25 to 79% by weight, preferably 30 to 75% by weight, more preferably from 35 to 70% by weight of molecule (s) bearing an amide wherein the nitrogen atom carries a hydrogen atom, hydrogen,

based on the total weight of the solvent composition (s).

[0050] According to one embodiment, the mass ratio / the molecules bearing at least one sulfoxide function and / molecules bearing at least one amide function is from 90/10 to 10/90, preferably from 80/20 to 20/80, more preferably 70/30 to 30/70, more preferably 60/40 to 40/60.

[0051] According to one embodiment, the solvent composition (s) comprises about 50% by weight of DMSO and about 50% by weight of 2-pyrrolidone, based on the total weight of the solvent composition (s).

[0052] According to one embodiment, the solvent composition (s) further comprises at least one other solvent, different from the two molecules described above. These include without limitation such as other solvents:

- the water ;

- ketones, such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, hexanone, cyclohexanone, éthylaminecétone, isophorone, trimethylcyclohexanone, gamma-butyrolactone, diacetone alcohol;

- amines, such as monoethanolamine (MEOA), diethanolamine (DEOA), propanolamine (PoA), the butyl / ' n-propanolamine (Bipoa), the / ' propanolamine so- (IPOA), the 2- [2- (3-amino-propoxy) ethoxy] ethanol, N-2- hydroxyéthyldiéthylènetriamine, the (3-methoxy) -propylamine (MOPA), 3-isopropoxypropylamine (IPOPA), monoethylamine, diethylamine, diethylaminopropylamine (DEAPA), triethylamine (TEA), acetonitrile;

- alcohols, such as ethanol, methanol, propanol, isopropanol, glycerol, diacetone alcohol, butanol, methyl isobutyl carbinol, hexylene glycol, benzyl alcohol;

- ethers, such as tetrahydrofuran (THF), methyl furan, methyl tetrahydrofuran, tetrahydropyran, glycoldialkyléther;

- esters, such as dibasic esters, dimethyl glutarate, dimethyl succinate on the dimethyladipate, butylacetate, ethylacetate, diethylcarbonate, dimethylcarbonate, propylene carbonate, éthylméthylcarbonate the glycérolcarbonate, dimethyl 2-methylglutarate, dimethyl-2-méthyladipate, dimethyl-2-methylsuccinate, N-Butyl propionate, benzyl acetate, éthyléthoxypropionate;

- sulfones, such as dimethylsulfone, sulfolane;

- aromatics, such as toluene, xylene;

- acetals, such as methylal, ethylal, butylal, dioxolane, TOU (tétraoxaundécane);

- E type of glycol ethers or P, such as dipropylene glycol dimethyl ether (DPGDME), dipropylene glycol methyl ether.

[0053] As the solvent other examples, one can also cite the following solvents: N-butylpyrrolidone, N-isobutylpyrrolidone, Nt-butylpyrrolidone, Nn-pentylpyrrolidone, N- (substituted-methyl butyl) pyrrolidone, N-propyl - or N-butyl pyrrolidone, nucleus-substituted or methyl-N- (methoxypropyl) pyrrolidone, polyglyme, ethyl diglyme, 1, 3-dioxolane, methyl-5- (dimethylamino) -2-méhyl-5-oxopentanoate.

[0054] According to one embodiment, the solvent composition (s) further comprises at least one pore forming agent, such as PEG or PVP.

[0055] The present invention also provides the use of the solvent composition (s) according to the invention to improve the stability of the polymer solutions.

[0056] The polymer solutions or polymer solutions are obtained by dissolving or dispersing the polymer in the solvent composition (s) according to the invention.

[0057] The polymer solutions or polymer solutions may be chosen from polyurethane solutions, solutions of polysulfone, polyphenylsulfone solutions, solutions polyethersulfone, polyvinylidene fluorides solutions (PVDF), cellulose acetate, polyamide-imides (PAI), or polyimide (PI).

[0058] Preferably, polymer solutions are solutions of polymers having sulfone or urethane functions. Preferably, polymer solutions are selected from polyurethane solutions, polyphenylsulfone solutions, polyethersulfone solutions, and the polysulfone solution, more preferably from polysulfone and polyurethane solutions, especially among polysulfone solutions .

[0059] The term "polysulfone" within the meaning of the present invention, means a polymer having at least two units (n> 2) of the formula:

[0060] The term "polyether" in the sense of the present invention, means a polymer having at least two units (n> 2) of the formula:

[0061] By "polyphenylsulfone" within the meaning of the present invention, means a polymer having at least two units (n> 2) of the formula:

[0062] For the purposes of the present invention, a polyether sulfone is not polysulfone.

[0063] The solvent compositions (s) according to the present invention effectively can improve the stability of polymer solutions at room temperature (temperature of from 20 ° C to 30 ° C, preferably about 25 ° C) or low temperature (temperature of from -10 ° C to + 10 ° C, preferably about 0 ° C), preferably the stability is improved both at room temperature and low temperatures.

[0064] The solvent compositions (s) according to the present invention can improve the storage stability of polymeric solutions, in particular for a storage time may vary from several hours to several weeks.

[0065] Improving the stability of the solutions may be characterized by obtaining a liquid solution, as opposed to a solid or a gel. Improvement can also be characterized by a transparent look or very lightly colored in contrast to a cloudy appearance. The improved stability can be assessed immediately after preparation of the solutions or after a prolonged period, for example ranging from 1 day to 3 weeks.

[0066] The present invention also provides a polymer solution, said solution comprising a solvent composition (s) comprising a mixture of at least one molecule having at least a sulfoxide function and at least one molecule having at least one function amide wherein the nitrogen atom carries a hydrogen atom (-NH-C (O) -), said solution being substantially free of polyether. Both molecules (that carrying the sulphoxide function and that carrying the amide function) are distinct from each other.

[0067] Preferably, the polymer solution according to the invention is completely free from polyethersulfones.

[0068] Preferably, the polymer solution of the invention is a polymer solution having sulfone or urethane functions, provided that said solution is substantially, especially totally free, polyethersulfones.

[0069] The polymer solution according to the invention may comprise a polysulfone and / or a polyurethane and / or a polyphenylsulfone.

[0070] According to a preferred embodiment, the polymer solution according to the invention is a polysulfone solution.

[0071] According to one embodiment of the invention, the solvent composition (s) according to the invention polymer solution consists essentially of molecules carrying a sulphoxide function and molecules bearing an amide group where the atom nitrogen carries a hydrogen atom (-NH-C (O) -).

[0072] Preferably, the molecule carrying an amide functional group is cyclic, in particular, the amide function may be a cyclic amide. Preferably the molecule bearing the amide is 2-pyrrolidone.

[0073] Preferably, the molecule carrying a sulphoxide function is dimethylsulfoxide (DMSO).

[0074] According to a particular embodiment, the solvent composition (s) of the polymer solution comprises DMSO and 2-pyrrolidone. According to one embodiment, the solvent composition (s) of the polymer solution of the invention consists essentially, and preferably exclusively, in DMSO and 2-pyrrolidone.

[0075] According to one embodiment, the solvent composition (s) of the polymer solution comprises:

- from 21 to 75% by weight, preferably 25 to 70% by weight, more preferably from 30 to 65% by weight of the molecule carrying a sulphoxide function,

- 25 to 79% by weight, preferably 30 to 75% by weight, more preferably from 35 to 70% by weight of the molecule bearing an amide wherein the nitrogen atom carries a hydrogen atom,

based on the total weight of the solvent composition (s).

[0076] According to one embodiment, the solvent composition (s) of the polymer solution consists essentially, and preferably exclusively, in:

- from 21 to 75% by weight, preferably 25 to 70% by weight, more preferably from 30 to 65% by weight of the molecule carrying a sulphoxide function,

- 25 to 79% by weight, preferably 30 to 75% by weight, more preferably from 35 to 70% by weight of the molecule bearing an amide wherein the nitrogen atom carries a hydrogen atom,

based on the total weight of the solvent composition (s).

[0077] According to one embodiment of the invention, the polymer solution comprises:

- from 5 to 50% by weight, preferably 8 to 35% by weight of polymers, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the solution.

[0078] According to one embodiment of the invention, the polymer solution consists essentially of:

- from 5 to 50% by weight, preferably 8 to 35% by weight of polymers, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the solution.

[0079] According to one embodiment of the invention, the polysulfone solution comprises:

- from 5 to 50% by weight, preferably 8 to 35% by weight of polysulfone, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the solution.

[0080] According to one embodiment of the invention, the polysulfone solution consists essentially of:

- from 5 to 50% by weight, preferably 8 to 35% by weight of polysulfone, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the solution.

[0081] According to one embodiment of the invention, the polyurethane solution comprises:

- from 5 to 50% by weight, preferably 8 to 35% by weight of polyurethane, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the solution.

[0082] According to one embodiment of the invention, the polyurethane solution consists essentially of:

- from 5 to 50% by weight, preferably 8 to 35% by weight of polyurethane, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the solution.

[0083] The invention also relates to a filtration membrane obtained from the polymer solution of the invention.

[0084] Preferably, the filtration membrane is a hollow fiber membrane can be used without limitation for the treatment of water or for dialysis.

[0085] Preferably, the membrane according to the invention is obtained from the polysulfone solution according to the invention.

[0086] The filtration membrane according to the invention can be obtained according to a method well known to those skilled in the art.

[0087] According to one embodiment of the invention, the filtration membrane is obtainable by a process comprising:

- providing a polymer, preferably a polysulfone,

- polymer dissolved in the solvent composition (s) according to the invention comprising a mixture of at least one molecule having a sulphoxide function and at least one molecule having at least an amide wherein the nitrogen atom carries a hydrogen atom (-NH-C (O) -) to obtain the polymer solution, preferably polysulfone, according to the invention

- realization of a hollow fiber by a solution of the polymer spinning process followed by quenching in a third solvent (eg water) to precipitate the polymer and migrate the solvent of the polymer solution to the third solvent ( coagulation: wet process)

- optionally recycling the solvent,

CLAIMS

1. A solvent composition (s) comprising a mixture of at least one molecule having at least a sulfoxide function and at least one molecule having at least an amide wherein the nitrogen atom carries a hydrogen atom ( -NH-C (O) -), said composition being substantially free of polyether.

2. Composition according to claim 1, wherein the molecule bearing the amide function is cyclic.

3. Composition according to one of claims 1 or 2, wherein the molecule carrying a sulphoxide function is dimethylsulfoxide.

4. Composition according to one of claims 1 to 3, wherein the molecule bearing an amide is 2-pyrrolidone.

5. Composition according to one of claims 1 to 4, comprising dimethyl sulfoxide and 2-pyrrolidone.

6. Composition according to one of claims 1 to 5, comprising:

- from 21 to 75% by weight, preferably 25 to 70% by weight, more preferably from 30 to 65% by weight of the molecule carrying a sulphoxide function,

- from 25 to 80% by weight, preferably 30 to 75% by weight, more preferably from 35 to 70% by weight of the molecule bearing an amide wherein the nitrogen atom carries a hydrogen atom,

based on the total weight of the composition.

7. Use of the composition according to one of claims 1 to 6 for improving the stability of solutions of polymers, preferably polymers having sulfone or urethane functions.

8. Use according to claim 7, wherein the polymer solution is a solution of polysulfone or polyethersulfone or polyphenylsulfone, preferably a polysulfone solution.

9. A polymer solution (s), said solution comprising a solvent composition (s) comprising a mixture of at least one molecule having at least a sulfoxide function and at least one molecule having at least one amide function where nitrogen atom carries a hydrogen atom (-NH-C (O) -), said polymer solution being substantially free of polyether.

10. polymer solution according to claim 9, wherein the polymer has the sulfone functions or urethane.

11. polymer solution according to claim 9 or 10, wherein the solvent composition (s) is as defined in one of claims 2 to 6.

12. polymer solution according to any of claims 9-1 1 comprising

- from 5 to 50% by weight, preferably 8 to 35% by weight of polymers, and

- from 50 to 95% by weight, preferably 65 to 92% by weight of the solvent composition (s),

based on the total weight of the polymer solution.

13. The filtration membrane obtained from the polymer solution according to one of claims 9 to 12.

14. An artificial leather obtained from the polymer solution according to one of claims 9 to 12.

15. Use of the polymer solution according to one of claims 9 to 12 for the manufacture of films, artificial leather, suede polymer, polymeric fibers, coating, membranes, batteries, electronic circuits, or for the protection of electrical cables.