TW202528404A - Thermoplastic polyurethane (tpu) with good mechanical properties and thermal dimensional stability - Google Patents

Abstract

The invention is directed to a composition comprising an thermoplastic polyurethane and an alkali metal salt, its respective production process and use.

Description

Thermoplastic polyurethane (TPU) with good mechanical properties and thermal dimensional stability

The present invention relates to a thermoplastic polyurethane material having good mechanical properties (including low compressive set) and good thermal dimensional stability.

While thermoplastic polyurethanes need to be thermoplastic for good processing, the final product requires a higher degree of thermoplastic resistance. To this end, a number of distinct approaches are described. WO 2018/146336 uses aromatic chain expanders, while WO 2015/144765 teaches a combination of at least two chain expanders.

The problem to be solved is to develop a thermoplastic polyurethane with good mechanical properties, low compression set and good thermal dimensional stability.

Surprisingly, it was found that thermoplastic polyurethane compositions containing alkaline metal salts meet these requirements.

The present invention relates to a composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the building blocks of polyisocyanate, polyol, and chain extender, and the composition contains an alkaline metal salt.

The first aspect and embodiment 1 of the present invention relate to a composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the structural components of polyisocyanate, polyol and chain extender, and the composition contains an alkaline metal salt.

The term "composition" means that the composition does not only contain (individual) polymers, but may contain several polymers, additives and/or adjuvants.

The term "comprising" is intended to include the individual substances, but may also include other substances.

Unless otherwise stated, the number average molecular weight Mn in the context of the present invention is preferably determined according to DIN 55672-1.

The compositions according to the present invention exhibit improved compression set, enhanced wear loss, and improved Vicat temperature. Meanwhile, other important mechanical properties, such as tensile strength, density, and hardness, remain at the same level. Despite these improved properties, the compositions can still be thermoplastically processed using standard processing techniques, such as injection molding and extrusion, among others.

Preferably, the thermoplastic polyurethane is prepared by reacting an organic polyisocyanate, preferably a diisocyanate, with a polyol, preferably a polyol having two isocyanate-reactive functional groups, also known as a polymer diol, or a mixture of a polyol having two isocyanate-reactive functional groups and a polyol having three isocyanate-reactive functional groups, also known as a polymer triol. In preferred embodiment 2 of any of the foregoing embodiments, the thermoplastic polyurethane is prepared by reacting an organic polyisocyanate, preferably a diisocyanate, with a polyol, preferably a polyol having two isocyanate-reactive functional groups, also known as a polymer diol, or in another preferred embodiment, a mixture of a polyol having two isocyanate-reactive functional groups and a polyol having three isocyanate-reactive functional groups, also known as a polymer triol. The polyol preferably has a number average molecular weight of 0.5×10 ³ g/mol to 100×10 ³ g/mol. The chain extender preferably has a molecular weight of 0.05×10 ³ g/mol to 0.5×10 ³ g/mol. The reaction is preferably carried out in the presence of a catalyst. In a preferred embodiment, the composition comprises an auxiliary agent, an additive or a mixture thereof.

The components organic isocyanates, preferably diisocyanates, polyols, and chain expanders are used individually or together as building blocks. Building blocks, including catalysts and/or auxiliaries and/or additives, if applicable, are also referred to as input materials.

To adjust the hardness and melt flow index of thermoplastic polyurethane (TPU), the molar ratio of the building blocks and the amount of chain extender can be varied. As a result, the hardness and melt viscosity increase with increasing isocyanate content, or with increasing the content of both isocyanate and chain extender, while the melt flow index decreases.

Preferably, the ratio of NCO groups to OH groups in the thermoplastic polyurethane is in the range of 1050 to 1500, more preferably in the range of 1050 to 1400, and more preferably in the range of 1050 to 1300. In preferred embodiment 3 according to any one of the aforementioned embodiments or one of the preferred embodiments thereof, the ratio of NCO groups to OH groups in the thermoplastic polyurethane is in the range of 1050 to 1500, more preferably in the range of 1050 to 1400, and more preferably in the range of 1050 to 1300.

The composition preferably has a Schroeder A hardness of between 50 and 100, preferably between 75 and 96, more preferably between 85 and 92, preferably measured according to DIN ISO 7619-1:2016.

The thermoplastic polyurethane preferably has a weight-average molecular weight of at least 0.04× ^10⁶ g/mol, more preferably at least 0.06× ^10⁶ g/mol, more preferably at least 0.07× ^10⁶ g/mol, and even more preferably at least 0.08× ^10⁶ g/mol. The upper limit of the weight-average molecular weight of the thermoplastic polyurethane (TPU) is generally determined by processability and the desired range of properties. Preferably, the weight-average molecular weight does not exceed 1× ^10⁶ g/mol, more preferably 0.8× ^10⁶ g/mol, more preferably 0.5× ^10⁶ g/mol, and even more preferably 0.3× ^10⁶ g/mol. The weight average molecular weight outlined herein is preferably determined by gel permeation chromatography, preferably according to DIN 55672-2 2016-03, using dimethylformamide (DMF) as solvent.

Preferably, the polyisocyanate is an organic polyisocyanate, more preferably an organic diisocyanate. In preferred embodiment 4 according to any one of the aforementioned embodiments or one of the preferred embodiments thereof, the polyisocyanate is an organic polyisocyanate, more preferably an organic diisocyanate. Further preferably, the isocyanate is selected from the group consisting of aliphatic, cycloaliphatic, araliphatic, and aromatic isocyanates, or a mixture thereof.

Preferably, the polyisocyanate is selected from the group consisting of tri-, tetra-, penta-, hexa-, hepta- and/or octamethylene diisocyanate, 2-methyl-pentamethylene 1,5-diisocyanate, 2-ethyl-butyl-1,4-diisocyanate, 1,5-pentamethylene diisocyanate (PDI), 1,4-butyl-diisocyanate, 1-isocyanato- -3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane and/or 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 2,4-p-phenylenediisocyanate (PPDI), 2,4-tetramethylenexylene diisocyanate (TMXD I), 4,4'-, 2,4'- and 2,2'-dicyclohexylmethane diisocyanate (H12MDI), 1,6-hexamethylene diisocyanate (HDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and/or -2,6-cyclohexane diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4-toluene diisocyanate, 2,6-toluene diisocyanate (TDI), 3,3'-dimethyl-diphenyl diisocyanate, 1,2-diphenylethane diisocyanate and/or phenylene diisocyanate, or a mixture thereof. In preferred embodiment 5, the polyisocyanate of the thermoplastic polyurethane according to one of the above embodiments or a combination of one of the preferred embodiments thereof is selected from the group consisting of tri-, tetra-, penta-, hexa-, hepta- and/or octamethylene diisocyanate, 2-methyl-pentamethylene 1,5-diisocyanate, 2-ethyl-butyl-1,4-diisocyanate, 1,5-pentamethylene 1,4-Bis(isocyanatomethyl)cyclohexane and/or 1,3-Bis(isocyanatomethyl)cyclohexane (HXDI), 2,4-p-phenylenediisocyanate (PPDI), 2,4-Tetramethylene xylene diisocyanate (TMXDI), 4,4'-, 2,4'- and 2,2'-dicyclohexylmethane diisocyanate (H12MDI), 1,6-hexamethylene diisocyanate (HDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and/or -2,6-cyclohexane diisocyanate, 2,2'-diphenylmethane diisocyanate , 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4-toluene diisocyanate, 2,6-toluene diisocyanate (TDI), 3,3'-dimethyl-diphenyl diisocyanate, 1,2-diphenylethane diisocyanate and/or phenylene diisocyanate, or a mixture thereof.

More preferably, the isocyanate is an aromatic diisocyanate, more preferably selected from the group consisting of 2,4-p-phenylene diisocyanate (PPDI), 2,4-tetramethylene xylene diisocyanate (TMXDI), 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4-toluene diisocyanate, 2,6-toluene diisocyanate (TDI), 3,3'-dimethyl-diphenyl diisocyanate, 1,2-diphenylethane diisocyanate and/or 1,4-phenylene diisocyanate, or a mixture thereof. In preferred embodiment 6 according to one of the preceding embodiments or one of the preferred embodiments thereof, the isocyanate is an aromatic diisocyanate, more preferably selected from the group consisting of 2,4-p-phenylene diisocyanate (PPDI), 2,4-tetramethylene xylene diisocyanate (TMXDI), 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4-toluene diisocyanate, 2,6-toluene diisocyanate (TDI), 3,3'-dimethyl-diphenyl diisocyanate, 1,2-diphenylethane diisocyanate and/or 1,4-phenylene diisocyanate, or a mixture thereof.

Particularly preferably, the isocyanate is 2,2'-diphenylmethane, 2,4'-diphenylmethane, or 4,4'-diphenylmethane diisocyanate (MDI), or a mixture thereof, and particularly preferably 4,4'-diphenylmethane diisocyanate. In preferred embodiment 7 according to one of the aforementioned embodiments 1 to 4 or one of the preferred embodiments thereof, the isocyanate is 2,2'-diphenylmethane, 2,4'-diphenylmethane, or 4,4'-diphenylmethane diisocyanate (MDI), or a mixture thereof, and particularly preferably 4,4'-diphenylmethane diisocyanate.

Preferably, the polyol has a statistical average of at least 1.8 and at most 2.4 Zerewitinoff-reactive hydrogen atoms. In preferred embodiment 8 according to one of the preceding embodiments or one of the preferred embodiments thereof, the polyol has a statistical average of at least 1.8 and at most 2.4 Zerewitinoff-reactive hydrogen atoms. This number is also referred to as the functionality of the isocyanate-reactive compound and represents the amount of isocyanate-reactive groups theoretically calculated per molecule from a given amount of substance. The functionality is preferably between 1.9 and 2.2, and particularly preferably 2.0. The polyol preferably has a number average molecular weight of 0.5×10 ³ g/mol to 8×10 ³ g/mol, more preferably 0.7×10 ³ g/mol to 6.0×10 ³ g/mol, even more preferably 0.8×10 ³ g/mol to 4.0×10 ³ g/mol.

Preferably, the polyol is linear. Preferably, the polyol comprises a single polyol or a mixture of at least two polyols, in which case the mixture meets the above requirements.

The polyol is preferably used in an amount of 1 mol % to 80 mol % based on the isocyanate group content of the polyisocyanate.

Polyols are also known as polyhydroxy polyols. Preferably, the polyol comprises a polyol selected from the group consisting of polyesterols, polyetherols, or polycarbonate diols, or a mixture thereof. More preferably, the polyol comprises a diol, also known as a polymer diol.

Preferably, the polyol comprises a polyether diol, further preferably selected from the group consisting of polyethylene glycol, polypropylene glycol, and polybutylene glycol, or a mixture thereof. In preferred embodiment 9 according to one of the aforementioned embodiments or one of the preferred embodiments thereof, the polyol comprises a polyether diol, further preferably selected from the group consisting of polyethylene glycol, polypropylene glycol, and polybutylene glycol, or a mixture thereof.

Preferably, the polyether comprises polytetrahydrofuran (PTHF). In preferred embodiment 10 according to one of the preceding embodiments or one of the preferred embodiments thereof, the polyether comprises polytetrahydrofuran (PTHF). In a preferred embodiment, the polyether polyol, preferably polytetrahydrofuran, has a number average molecular weight of 0.6×10 ³ g/mol to 3.0×10 ³ g/mol, more preferably 0.7×10 ³ g/mol to 2.5×10 ³ g/mol.

Preferably, the polytetrahydrofuran is a mixture of polytetrahydrofuran having a number average molecular weight of 0.8×10 ³ g/mol to 1.4×10 ³ g/mol and polytetrahydrofuran having a number average molecular weight of 1.8×10 ³ g/mol to 2.4×10 ³ g/mol, more preferably 0.9×10 ³ g/mol to 1.1×10 ³ g/mol and 1.9×10 ³ g/mol to 2.1×10 ³ g/mol ^, and even more preferably 1.0×10 3 g/mol to 2.0×10 ³ g/mol. In preferred embodiment 11 according to embodiment 10 or one of its preferred embodiments, the polytetrahydrofuran is a mixture of polytetrahydrofuran having a number average molecular weight of 0.8×10 ³ g/mol to 1.4×10 ³ g/mol and polytetrahydrofuran having a number average molecular weight of 1.8×10 ³ g/mol to 2.4×10 ³ g/mol, more preferably 0.9×10 ³ g/mol to 1.1×10 ³ g/mol and 1.9×10 ³ g/mol to 2.1×10 ³ g/mol, more preferably 1.0×10 ³ g/mol to 2.0×10 ³ g/mol.

The advantage of polyether polyols is that they are more stable to hydrolysis and therefore will be used in applications where this is required.

Preferably, the polyol comprises a polyester polyol. In preferred embodiment 12 according to one of the aforementioned embodiments or one of its preferred embodiments, the polyol comprises a polyester polyol. Preferably, the polyester polyol is selected from the group consisting of: reaction products of polyhydroxy alcohols, polymerization products of lactones, and polymerization products of dicarboxylic acids and polyhydroxy alcohols, or mixtures thereof. The term "lactone" refers to a cyclic ester of a hydroxyl carboxylic acid. Such polyester polyols include hydroxyl-terminated reaction products of polyhydroxy alcohols, polyester polyols obtained as polymerization products of lactones (e.g., caprolactone) and polyols, and polyester polyols obtained by polymerization of dicarboxylic acids (e.g., adipic acid) and polyhydroxy alcohols. Preferred polyester polyols include the polymerization products of lactones or polycaprolactones and those obtained by polymerization of dicarboxylic acids and polyhydroxy alcohols.

Preferably, the polyester polyol is obtained by polymerization of a dicarboxylic acid and a polyhydroxy alcohol. Preferably, the dicarboxylic acid is at least one of a C4 to C12 dicarboxylic acid. Preferably, the polyhydroxy alcohol is at least one of a C2 to C14 diol.

More preferably, the C4 to C12 dicarboxylic acid is an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid. The aliphatic dicarboxylic acid is preferably selected from succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, and sebacic acid, or a mixture thereof. In another preferred embodiment, the dicarboxylic acid is selected from phthalic acid, isophthalic acid, and terephthalic acid, or a mixture thereof.

More preferably, the dicarboxylic acid is selected from the group consisting of succinic acid, glutaric acid, adipic acid, suberic acid, phthalic acid, isophthalic acid and terephthalic acid, or a mixture thereof.

Most preferably, the dicarboxylic acid is selected from the group consisting of adipic acid, suberic acid and phthalic acid, or a mixture thereof.

Preferably, the diol used to obtain the polyester polyol is selected from the group consisting of ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 2,2-dimethylpropane-1,3-diol, 1,3-propylene glycol, 2-methyl-1,3-propanediol, and dipropylene glycol, or a mixture thereof. More preferably, the diol is selected from the group consisting of ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, or a mixture thereof. Most preferably, the diol is selected from the group consisting of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, or a mixture thereof.

Polyester polyols have poor hydrolytic stability and are preferred in applications requiring some biodegradability.

Preferably, the polyol comprises a polycarbonate diol, preferably an aliphatic polycarbonate diol. In preferred embodiment 13 according to one of the aforementioned embodiments or one of its preferred embodiments, the polyol comprises a polycarbonate diol, preferably an aliphatic polycarbonate diol. Preferred polycarbonate diols are polycarbonate diols based on alkane diols. In a preferred embodiment, the polycarbonate diol is produced by polycondensation of phosgene and a diol, by ring-opening polymerization of a cyclic carbonate, or by transesterification of a carbonic acid diester.

Preferred polycarbonate diols are OH difunctional polycarbonate diols, preferably OH difunctional aliphatic polycarbonate diols. Preferred polycarbonate diols are based on butanediol, pentanediol, or hexanediol. In particular, the polycarbonate diols are based on 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 3-methylpentane-(1,5)-diol, or mixtures thereof. More preferred polycarbonate diols are based on 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, or mixtures thereof. Polycarbonate diols based on butanediol and hexanediol, polycarbonate diols based on pentanediol and hexanediol, and polycarbonate diols based on hexanediol, or mixtures thereof, are also preferred.

Preferably, the polycarbonate diol has ^{a number average molecular weight Mn of 0.5×10 3 g/mol to 4.0×10 3 g/mol, more preferably 0.65×10 3 g / mol} to 3.0×10 ³ g/mol, more preferably 0.8×10 3 g/mol to 2.5×10 ³ g/mol, more preferably 1.8×10 ³ g/mol to 2.2×10 ³ g/mol or 0.8×10 3 g/mol to 1.2×10 ³ g/mol.

Polycarbonate diols have better microwave transparency, less dirt absorption and better flame retardancy.

In one preferred embodiment, the polyol is a single polyol. In another preferred embodiment, the polyol is a mixture of two or more of the above preferred polyols.

Preferably, the chain extender is an aliphatic, araliphatic, aromatic, or cycloaliphatic compound, or a mixture thereof. In preferred embodiment 14 according to any one of the aforementioned embodiments or one of the preferred embodiments thereof, the chain extender is an aliphatic, araliphatic, aromatic, or cycloaliphatic compound, or a mixture thereof. Preferably, the chain extender has a molecular weight of 50 g/mol to 499 g/mol. The chain extender is a single chain extender or a mixture of at least two chain extenders.

Preferably, the chain extender has two or three isocyanate-reactive groups, or a mixture thereof, more preferably a mixture thereof. In preferred embodiment 15 according to any one of the aforementioned embodiments or one of the preferred embodiments thereof, the chain extender has two or three isocyanate-reactive groups, or a mixture thereof, more preferably a mixture thereof. Isocyanate-reactive groups are also referred to as functional groups having respective functionalities.

Preferably, the chain extender has a functionality of 2.0 to 2.1, more preferably 2.00 to 2.05, more preferably 2.00 to 2.03, and most preferably 2.0. In preferred embodiment 16 of the aforementioned embodiments, the chain extender has a functionality of 2.0 to 2.1, more preferably 2.00 to 2.05, more preferably 2.00 to 2.03, and most preferably 2.0. Preferred chain extenders are amines and/or alkanols. Further preferably, the chain extender contains 2 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, in the alkylene group.

Preferably, the chain extender is a mixture of an alkanediol and an alkanetriol. In preferred embodiment 17 according to any one of the aforementioned embodiments or one of the preferred embodiments thereof, the chain extender is a mixture of an alkanediol and an alkanetriol. The alkanol preferably has only a primary hydroxyl group. Particularly preferably, the alkanediol is selected from 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, hydroquinone bis(β-hydroxyethyl) ether (HQEE), and di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, or deca-alkylene glycols, and preferably the corresponding oligo- and/or poly-alkylene glycols, or mixtures thereof. More preferably, the alkanediol is selected from the group consisting of 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol, or mixtures thereof, with 1,4-butanediol being most preferred. The alkanetriol is preferably selected from glycerol, trihydroxymethylpropane, or mixtures thereof.

Preferably, the chain extender is selected from the group consisting of 1,2-ethanediol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol, or a mixture thereof, and most preferably 1,4-butanediol. In preferred embodiment 18 according to one of the above embodiments 1 to 14 or one of the preferred embodiments thereof, the chain extender is selected from the group consisting of 1,2-ethanediol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol, or a mixture thereof, and most preferably 1,4-butanediol.

Alkali metal salts are inorganic compounds containing elements from Group 1a of the Periodic Table of the Elements.

Preferably, the alkaline metal salt is selected from lithium salts, sodium salts, potassium salts, galvanneal salts, caesium salts, and cobalt salts, or a mixture thereof. More preferably, the alkaline metal salt is selected from sodium salts and potassium salts, or a mixture thereof, and most preferably, it is a potassium salt. In preferred embodiment 19, which comprises all of the features of one of the preceding embodiments or one of its preferred embodiments, the alkaline metal salt is selected from lithium salts, sodium salts, potassium salts, galvanneal salts, caesium salts, and cobalt salts, or a mixture thereof. More preferably, the alkaline metal salt is selected from sodium salts and potassium salts, or a mixture thereof, and most preferably, it is a potassium salt.

Preferably, the loading of the alkaline metal salt is in the range of 0.1 wt ppm to 100 wt ppm relative to the entire composition, more preferably 0.1 wt ppm to 50 wt ppm relative to the entire composition, more preferably 0.1 wt ppm to 20 wt ppm, and even more preferably 0.5 wt ppm to 10 wt ppm. In preferred embodiment 20 comprising all the features of one of the preceding embodiments or one of the preferred embodiments thereof, the loading of the alkaline metal salt is in the range of 0.1 wt ppm to 100 wt ppm relative to the entire composition, preferably in the range of 0.1 wt ppm to 50 wt ppm relative to the entire composition, more preferably in the range of 0.1 wt ppm to 20 wt ppm, and even more preferably in the range of 0.5 wt ppm to 10 wt ppm.

Preferably, the alkali metal salt comprises an alkali metal carboxylate, more preferably potassium carboxylate, sodium carboxylate, or a mixture thereof. In preferred embodiment 21 comprising all of the features of one of the preceding embodiments or one of its preferred embodiments, the alkali metal salt comprises an alkali metal carboxylate, more preferably potassium carboxylate, sodium carboxylate, or a mixture thereof.

Preferably, the alkali metal salt comprises potassium acetate or potassium formate. In preferred embodiment 22 comprising all of the features of one of the preceding embodiments or one of its preferred embodiments, the alkali metal salt comprises potassium acetate or potassium formate.

Preferably, an alkaline metal salt is used as a catalyst for the construction of an alloformate, uretdione, biuret or isocyanurate structure or a mixture thereof in the composition. In preferred embodiment 23 comprising all of the features of one of the preceding embodiments or one of its preferred embodiments, an alkaline metal salt is used as a catalyst for the construction of an alloformate, uretdione, biuret or isocyanurate structure or a mixture thereof in the composition.

Preferably, the composition further comprises a catalyst. In preferred embodiment 24 according to any one of the aforementioned embodiments or one of the preferred embodiments thereof, the composition further comprises a catalyst. The catalyst may be a single catalyst or a mixture of several catalysts.

The catalyst preferably accelerates the reaction between the NCO group of the isocyanate and the hydroxyl groups of the polyol and the chain expander. In a preferred embodiment, the catalyst is selected from the group consisting of a tertiary amine and an organometallic compound or a mixture thereof.

Preferably, the organometallic compound is selected from the group consisting of titanium esters, iron compounds, tin compounds, and bismuth salts, or a mixture thereof. In preferred embodiment 25 according to any one of the aforementioned embodiments or one of the preferred embodiments thereof, the organometallic compound is selected from the group consisting of titanium esters, iron compounds, tin compounds, and bismuth salts, or a mixture thereof. A preferred iron compound is iron(III) acetylacetonate. A preferred tin compound is selected from the group consisting of tin diacetate, tin dioctoate, tin dilaurate, tin(II) neodecanoate, and dialkyltin salts of aliphatic carboxylic acids, or a mixture thereof. Preferably, the catalyst is tin dioctoate, tin(II) neodecanoate, or a mixture thereof. A preferred titanium ester is tetrabutyl orthotitanium. Preferred bismuth salts are those in oxidation state 2 or 3, particularly 3. Preferred are salts of carboxylic acids, preferably those having 6 to 14 carbon atoms, particularly 8 to 12 carbon atoms. Very preferred bismuth salts are bismuth(III) neodecanoate, bismuth 2-ethylhexanoate, or bismuth octanoate, or mixtures thereof.

The catalyst is preferably used in an amount of 0.0001 to 0.1 parts by weight per 100 parts by weight of the polyol. Tin catalysts, particularly tin dioctoate, are preferred.

Preferably, the composition comprises SDO (tin(II)-2-ethylhexanoate), tin(II) neodecanoate, or a mixture thereof, preferably in an amount of 0.035-0.04 parts by weight relative to the entire composition. In preferred embodiment 26 according to any one of the preceding embodiments or one of the preferred embodiments thereof, the composition comprises SDO (tin(II)-2-ethylhexanoate), tin(II) neodecanoate, or a mixture thereof, preferably in an amount of 0.035-0.04 parts by weight relative to the entire composition.

Preferably, the composition contains an auxiliary agent or additive. In preferred embodiment 27 according to one of the aforementioned embodiments or one of its preferred embodiments, the composition contains an auxiliary agent or additive. Preferably, the auxiliary agent or additive is selected from the group consisting of surfactants, fillers, flame retardants, nucleating agents, oxidation stabilizers, lubricating agents, mold release agents, dyes, pigments, inorganic fillers and/or organic fillers, reinforcing agents, plasticizers, antistatic agents, stabilizers, preferably stabilizers against hydrolysis, light, heat, or discoloration, inorganic fillers, organic fillers, reinforcing agents, plasticizers, or mixtures thereof.

Stabilizers within the meaning of the present invention are additives that protect plastics or plastic compositions from harmful environmental influences. Preferred examples are primary or secondary antioxidants, hindered phenols, hindered amine light stabilizers, UV absorbers, phosphites, hydrolysis inhibitors, quenchers and flame retardants. A comprehensive list of commercial stabilizers is given in Plastics Additives Handbook, 5th Edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001 ([1]), p.98-S136.

Preferred plasticizers are selected from tributyl O-acetyl citrate, dipropylene glycol dibenzoate, and diisononyl cyclohexane-1,2-dicarboxylate, or mixtures thereof. Tributyl O-acetyl citrate is commercially available as Citrofol® BII from Jungbunzlauer Swiss AG, Switzerland, dipropylene glycol dibenzoate as WTH-Ester DPGA from Walter Thieme Handel GmbH, and diisononyl cyclohexane-1,2-dicarboxylate as Hexamoll® Dinch from BASF SE, Ludwigshafen, Germany. Soft materials with low hard segment content are difficult to synthesize and process. Plasticizers are used to soften thermoplastic polyurethanes with higher hard segment content, making them easier to synthesize and process, thereby improving the material's properties.

Preferably, the UV absorber has a number average molecular weight greater than 0.3×10 ³ g/mol, particularly greater than 0.39×10 ³ g/mol. Furthermore, a preferred UV absorber has a molecular weight not exceeding 5×10 ³ g/mol, particularly preferably not exceeding 2×10 ³ g/mol.

The UV absorber is preferably selected from the group consisting of cinnamate, oxanilide, diphenyl ketone, and benzotriazole, or a mixture thereof. Benzotriazole is particularly suitable as a UV absorber. Examples of particularly suitable UV absorbers include Tinuvin® 213, Tinuvin® 234, Tinuvin® 312, Tinuvin® 571, Tinuvin® 384, and Eversorb® 82.

Preferably, the UV absorber is added in an amount of 0.01 wt.% to 5 wt.%, more preferably 0.1 wt.% to 2.0 wt.%, especially 0.2 wt.% to 0.5 wt.%, based on the total weight of the composition.

Often, UV stabilization based on antioxidants and UV absorbers as described above is not sufficient to ensure good stability of the composition against the harmful effects of UV radiation. In such cases, hindered-amine light stabilizers (HALS) are added to the composition in addition to antioxidants and/or UV absorbers, or as sole stabilizers.

Examples of commercially available HALS stabilizers can be found in Plastics Additive Handbook, 5th edition, H. Zweifel, Hanser Publishers, Munich, 2001, pp. 123-136.

Particularly preferred hindered amine light stabilizers are bis-(1,2,2,6,6-pentamethylpiperidinyl) sebacate (Tinuvin® 765, Ciba Spezialitätenchemie AG) and the condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid (Tinuvin® 622). The condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid (Tinuvin® 622) is particularly preferred. The titanium content of the final product is preferably less than 150 ppm by weight, more preferably less than 50 ppm by weight, and especially less than 10 ppm by weight, based on all components used.

The HALS compound is preferably used in a concentration of 0.01 wt.% to 5 wt.%, particularly preferably 0.1 wt.% to 1 wt.%, especially 0.15 wt.% to 0.3 wt.%, based on the total weight of the composition.

Particularly preferred UV stabilizers contain a mixture of the above-mentioned preferred amounts of a phenolic stabilizer, a benzotriazole, and a HALS compound.

Further information on the aforementioned auxiliaries and additives can be found in the technical literature, for example in Plastics Additives Handbook, 5th edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001.

Preferably, the compression set of the composition is less than 20%, preferably less than 18%, more preferably less than 16%, more preferably less than 12%, and more preferably less than 10%, preferably measured according to DIN ISO 815-1, 2022-04, 23°C, 72 hours, and a relaxation time of 30 minutes. In preferred embodiment 28 according to any one of the preceding embodiments or one of their preferred embodiments, the compression set of the composition is less than 20%, preferably less than 18%, more preferably less than 16%, more preferably less than 12%, and more preferably less than 10%, preferably measured according to DIN ISO 815-1, 2022-04, 23°C, 72 hours, and a relaxation time of 30 minutes.

The present invention also relates to making a composition according to the present invention. Another aspect and embodiment 29 of the present invention is making a composition according to any one of the above embodiments or one of the preferred embodiments.

Preferably, the building blocks of a diisocyanate, a polyol, a chain expander, and an alkaline metal salt are mixed to produce the thermoplastic polyurethane, and then other components of the composition are added as needed. In preferred embodiment 30 of the aforementioned embodiments, the building blocks of a diisocyanate, a polyol, a chain expander, and an alkaline metal salt are mixed to produce the thermoplastic polyurethane, and then other components of the composition are added as needed.

Preferably, the method according to the present invention is discontinuous or continuous. In preferred embodiment 31, the method according to any of the above embodiments 29 to 30 is discontinuous or continuous. Preferred continuous manufacturing methods are a reaction extruder method, a belt line method, or a "one shot" method, preferably a "one shot" method or a reaction extruder method, and most preferably a reaction extruder method.

These methods can be used by direct mixing of the building blocks or by applying a prepolymer method.

The polyisocyanate prepolymer can be obtained by reacting an excess of the polyisocyanate with the polyol at a temperature preferably between 30°C and 100°C, more preferably at 8 x 10°C, by directly mixing the isocyanate and the polyol or applying the isocyanate to the polyol.

In the "one-shot" method, the building blocks diisocyanate and polyol, preferably polyol diol, and alkaline metal salt, and chain expander, and in another preferred embodiment, catalyst, are mixed together. This can be done sequentially or simultaneously. In the extruder method, the building blocks diisocyanate, alkaline metal salt, and polyol, preferably polyol diol, and chain expander, and in another preferred embodiment, catalyst, are mixed together.

The mixing in the "one-shot" process or reactive extrusion process is preferably carried out at a temperature between 100°C and 280°C, more preferably between 140°C and 250°C.

Preferably, the building blocks of isocyanate, polyol, and chain expander are reacted in the presence of a catalyst and, if necessary, auxiliary agents and/or additives in amounts such that the equivalent ratio of the sum of the NCO groups of the isocyanate, preferably the diisocyanate, and the hydroxyl groups of the isocyanate-reactive component and the chain expander is from 1.05:1 to 1.5:1, preferably from 1.05:1 to 1.4:1, and more preferably from 1.05:1 to 1.3:1. In preferred embodiment 32 according to any one of the aforementioned embodiments 29 to 31 or one of their preferred embodiments for preparing thermoplastic polyurethane, the building blocks of isocyanate, polyol, and chain extender are reacted in the presence of a catalyst and, if necessary, auxiliary agents and/or additives in amounts such that the equivalent ratio of the sum of the NCO groups of the isocyanate, preferably the diisocyanate, and the hydroxyl groups of the isocyanate-reactive component and the chain extender is from 1.05:1 to 1.5:1, preferably from 1.05:1 to 1.4:1, and more preferably from 1.05:1 to 1.3:1.

The auxiliary agent or additive or a mixture thereof is added during the synthesis of the thermoplastic polyurethane or to the thermoplastic polyurethane derived from the building blocks. The latter is preferred. This is particularly the case if the additive or auxiliary agent is not inert toward isocyanates, chain expanders, isocyanate-reactive compounds or catalysts.

In a preferred embodiment, the synthesis of the thermoplastic polyurethane is carried out in an extruder, more preferably a twin-screw extruder. Twin-screw extruders are preferably operated in forward conveying mode, thus allowing for more precise setting of the temperature and output of the extruder.

Preferably, the composition according to the present invention or the composition obtained according to the method of the present invention is in the form of pellets or powder. In a preferred embodiment 33, the composition obtained according to one of embodiments 1 to 28 or according to the method of one of embodiments 29 to 32, or one of their respective preferred embodiments, is in the form of pellets or powder. The pellets or powder in a preferred embodiment are dense materials. In another preferred embodiment, the pellets are expanded materials, also known as expanded beads or expanded powder. Beads or expanded beads in a preferred embodiment are particles with a maximum extension of between 1 mm and 5 cm. Powder in a preferred embodiment is particles with a maximum size of 1 mm. Preferably, the powder size is between 1×10 ^-6 m and 1 mm.

Another aspect of the present invention is expanded beads or expanded particles made from the composition according to the present invention or obtained according to the method according to the present invention. Therefore, another aspect of the present invention and Embodiment 34 are expanded beads or expanded particles made from a composition according to one of Embodiments 1 to 28 or one of the preferred embodiments thereof, or a composition obtained according to the method of one of Embodiments 29 to 32.

The production of expanded beads and molded bodies produced therefrom is well known (see, for example, WO 94/20568, WO 2007/082838 A1, WO 2017030835, WO 2013/153190 A1, WO 2010010010), which are incorporated herein by reference.

Another aspect of the present invention is the use of the composition according to the present invention, or the composition obtained according to the method of the present invention, or the pellets or powder according to the present invention, for manufacturing an article. Another aspect of the present invention and Embodiment 35 is the use of the composition according to any one of Embodiments 1 to 28, or one of the preferred embodiments thereof, or the composition obtained according to the method of any one of Embodiments 29 to 32, or one of the preferred embodiments thereof, or the pellets or powder according to Embodiment 33 or 34, or one of the preferred embodiments thereof, for manufacturing an article.

In a preferred embodiment, the composition is injection molded, calendered, powder sintered, or extruded to form an article.

Yet another aspect of the present invention is an article made using the composition according to the present invention. Yet another aspect of the present invention is an article made using the composition according to any one of Embodiments 1 to 28, or one of the preferred embodiments thereof, or the composition obtained by the method according to any one of Embodiments 29 to 32, or one of the preferred embodiments thereof, or the pellets or powder according to Embodiment 33 or 34, or one of the preferred embodiments thereof.

Preferably, the article is selected from the group consisting of: cables, housings, mobile phones, coatings, coverings, damping elements, corrugated tubes, foils, fibers, film moldings, roofs or floors of buildings or vehicles, nonwovens, gaskets, packaging materials, rolls, soles, midsoles, hoses, cables, cable connectors, cable sheaths, pillows, laminates, telephones, Materials, belts, saddles, foam, foam prepared by additional foaming, plug connectors, televisions, trailing cables, solar modules, car linings, wiper blades, elevator load-bearing components, rope systems, machine drive belts, preferred passenger conveyors, passenger conveyor handrails, modifiers for thermoplastic materials, meaning substances that affect the properties of another material. Each of these products is itself a preferred embodiment, also referred to as an application.

More preferably, the product is exposed to high mechanical and thermal stresses.

The present invention is further illustrated by the following set of specific examples and the combination of specific examples generated by the indicated dependencies and back-references. In particular, it is worth noting that in each case of referring to a series of specific examples, for example, in the context of the phrase "the method of any one of Specific Examples 1 to 4", it is intended that each specific example within the scope is clearly disclosed to a person skilled in the art, that is, the wording of the phrase should be understood by a person skilled in the art as synonymous with "the method of any one of Specific Examples 1, 2, 3, and 4". In addition, it is expressly pointed out that the following set of specific examples represents a suitable structured part of the general description of the preferred aspects of the present invention and therefore appropriately supports but does not represent the claims of the present invention.

1. A composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the following building blocks: a diisocyanate, a polyol, a chain expander, wherein the composition contains an alkaline metal salt in an amount ranging from 0.1 ppm to 100 ppm relative to the total weight of the composition.

2. The composition of embodiment 1, wherein the alkaline metal salt loading is in the range of 0.1 ppm to 50 ppm, preferably in the range of 0.1 ppm to 20 ppm, and more preferably in the range of 0.5 ppm to 10 ppm, relative to the total amount of the composition.

3. The composition according to embodiment 1 or 2, wherein the alkaline metal salt comprises an alkaline metal carboxylate.

4. The composition of any one of embodiments 1 to 3, wherein the alkaline metal salt comprises potassium acetate or potassium formate.

5. The composition of any one of embodiments 1 to 4, wherein the alkaline metal salt comprises potassium acetate.

6. The composition according to any one of embodiments 1 to 5, wherein the composition further comprises a catalyst.

7. A composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the following building blocks: a diisocyanate, a polyol, a chain expander, wherein the composition comprises an alkaline metal salt in an amount ranging from 0.1 ppm to 100 ppm relative to the total amount of the composition, and wherein the composition further comprises a catalyst.

8. The composition according to embodiment 6 or 7, wherein the catalyst is selected from the group consisting of a tertiary amine and an organometallic compound, or a mixture thereof.

9. A composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the following building blocks: a diisocyanate, a polyol, a chain expander, wherein the composition comprises an alkaline metal salt in an amount ranging from 0.1 ppm to 100 ppm relative to the total weight of the composition, wherein the composition further comprises a catalyst selected from the group consisting of a tertiary amine and an organometallic compound, or a mixture thereof.

10. The composition according to embodiment 8 or 9, wherein the organometallic compound is selected from the group consisting of titanium esters, iron compounds, tin compounds and bismuth salts, or a mixture thereof.

11. A composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the following building blocks: a diisocyanate, a polyol, a chain expander, wherein the composition comprises an alkaline metal salt in an amount ranging from 0.1 ppm to 100 ppm relative to the total amount of the composition, wherein the composition further comprises a catalyst selected from the group consisting of a tertiary amine and an organometallic compound, or a mixture thereof, wherein the organometallic compound is selected from the group consisting of a titanium ester, an iron compound, a tin compound, and a bismuth salt, or a mixture thereof.

12. The composition according to any one of examples 1 to 11, wherein the compression set of the composition is less than 28%, preferably less than 25%, and more preferably less than 23%, as measured according to DIN ISO 815-1:2022-04, 70°C, 24 hours, and a relaxation time of 30 minutes.

13. The composition according to any one of embodiments 1 to 12, wherein the polyisocyanate is an aromatic polyisocyanate, preferably methylene diphenyl diisocyanate (MDI).

14. The composition of any one of embodiments 1 to 10, wherein the chain extender has 2 or 3 isocyanate-reactive groups, or a mixture thereof, more preferably, the chain extender has a functionality of 2.0 to 2.1, more preferably 2.00 to 2.05, and even more preferably 2.00 to 2.03.

15. A method for producing a composition according to any one of embodiments 1 to 14, wherein the building components diisocyanate, polyol, chain extender and alkaline metal salt are mixed to produce a thermoplastic polyurethane and then the components of the composition are added as needed.

16. Use of a composition according to any one of Embodiments 1 to 14 or a composition obtained by the method according to Embodiment 15 for manufacturing an article.

17. An article of manufacture using the composition according to any one of Embodiments 1 to 14 or the composition obtained by the method according to Embodiment 15.

18. A composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the following building blocks: a diisocyanate, a polyol, a chain expander, wherein the composition comprises an alkaline metal salt.

19. The composition of Example 18, wherein the alkaline metal salt loading is between 0.1 ppm and 100 ppm, preferably between 0.1 ppm and 50 ppm, more preferably between 0.1 ppm and 20 ppm, and even more preferably between 0.5 ppm and 10 ppm, relative to the total amount of the composition.

20. The composition of embodiment 18 or 19, wherein the alkaline metal salt comprises an alkaline metal carboxylate.

21. The composition of any one of embodiments 18 to 20, wherein the alkaline metal salt comprises potassium acetate or potassium formate.

22. The composition of any one of embodiments 18 to 21, wherein the alkaline metal salt comprises potassium acetate.

23. The composition according to any one of examples 18 to 22, wherein the compression set of the composition is less than 28%, preferably less than 25%, and more preferably less than 23%, as measured according to DIN ISO 815-1:2022-04, 70°C, 24 hours, and a relaxation time of 30 minutes.

24. The composition according to any one of embodiments 18 to 23, wherein the polyisocyanate (A) is an aromatic polyisocyanate, preferably methylene diphenyl diisocyanate (MDI).

25. The composition of any one of embodiments 18 to 24, wherein the chain extender has 2 or 3 isocyanate-reactive groups, or a mixture thereof, more preferably, the chain extender has a functionality of 2.0 to 2.1, more preferably 2.00 to 2.05, and even more preferably 2.00 to 2.03.

26. A method for producing a composition according to any one of embodiments 18 to 25, wherein the building blocks diisocyanate, polyol, chain extender and alkaline metal salt are mixed to produce a thermoplastic polyurethane and then components of the composition are added as needed.

The present invention is further illustrated by the following examples. Examples

1. Example 1 - Materials Used: KX324: A mixture of 50 wt% potassium acetate (KOAc) and 50 wt% 1,2-ethylene glycol (MEG); PolyTHF1000: Polytetramethylene glycol (PTMG, PTHF) with an average molecular weight ( _MW ) of 1.0∙ ^{10 3} g/mol, commercially available from BASF SE, Germany; PolyTHF2000: Polytetramethylene glycol (PTMG, PTHF) with an average molecular weight ( _MW ) of 2.0∙10 3 g/mol, commercially available from BASF SE, Germany; Poly(butylene-ethylene) adipate: CAS No. 26570-73-0, the reaction product of adipic acid, butane-1,4-diol, and ethylene glycol, with an average molecular weight of 3.0∙10 ³ g/mol. Poly(butylene-1,4-diol) adipate: CAS number: 25214-15-7, reaction product of adipic acid, butane-1,4-diol, and hexane-1,6-diol, with an average molecular weight of 2.0∙10 ³ g/mol. Poly(butylene adipate): CAS number: 25103-87-1, reaction product of adipic acid and butane-1,4-diol, with an average molecular weight of 2.5∙10 ³ g/mol. Citrofol BII: tributyl O-acetyl citrate (CAS number: 77-90-7), commercially available from Jungbunzlauer Swiss AG, Switzerland.

2. Example 2 - Preparation of the composition

The polyol and chain expander are heated to 80°C, optionally mixed with a catalyst and co-agents, and then added to a mixing kettle with an outlet, along with the diisocyanate preheated to 40°C. The mixture is poured continuously onto a Teflon belt. The belt transports the reaction mixture through an oven with different zones set to the following temperature profile: 330°C - 330°C - 320°C - 320°C - 310°C - 180°C - 180°C - 180°C - 170°C - 160°C, with a belt speed of 0.8 m/min. The amounts of the individual raw materials are given in Tables 1 to 3. The amounts of the input materials are given in weight % relative to the total amount of each component in the following table.

Table 1. TPU compositions containing polytetramethylene glycol composition A1 A2 B1 B2 C1 C2 D1 D2 Index 1000 1200 1000 1200 1000 1200 1000 1200 MDI 25.9 30.1 32.2 37.1 35.7 41.1 37.6 43.4 PolyTHF1000 34.8 32.7 61.9 57.0 56.7 51.2 53.8 48.0 PolyTHF2000 34.8 32.7 - - - - - - 1,4-Butanediol 4.6 4.6 5.9 5.9 7.7 7.7 8.6 8.6 KX324 - 0.5∙10 ^-3 - 0.5∙10 ^-3 - 0.5∙10 ^-3 - 0.5∙10 ^-3

Table 2. TPU compositions containing poly(butylene-ethylene) adipate composition E1 E2 F1 F2 G1 G2 H1 H2 Index 1000 1200 1000 1200 1000 1200 1000 1200 MDI 21.1 24.9 25.1 29.6 27.7 32.6 31.7 37.4 Poly(butylene-ethylene) adipate 73.6 69.8 68.0 63.5 64.4 59.5 58.8 53.1 1,4-Butanediol 5.3 5.3 6.9 6.9 7.9 7.9 9.5 9.5 KX324 - 0.5∙10 ^-3 - 0.5∙10 ^-3 - 0.5∙10 ^-3 - 0.5∙10 ^-3

Table 3. Compositions of TPUs containing poly(butylene-pentylene) adipate. composition I1 I2 J1 J2 K1 K2 L1 L2 Index 1000 1200 1000 1200 1000 1200 1000 1200 MDI 21.4 24.9 25.9 30.2 28.4 33.2 35.0 41.1 Poly(butylene-pentylene) adipate 63.9 60.3 68.1 63.8 64.5 59.7 54.9 48.8 1,4-Butanediol 4.6 4.7 6.0 6.0 7.1 7.1 10.1 10.1 Citrofol BII 10.1 10.1 - - - - - - KX324 - 0.5∙10 ^-3 - 0.5∙10 ^-3 - 0.5∙10 ^-3 - 1.0∙ ^10-3

Table 4. TPU compositions containing polybutylene adipate composition M1 M2 N1 N2 O1 O2 P1 P2 Index 1000 1200 1000 1200 1000 1200 1000 1200 MDI 23.9 28.0 25.0 29.3 25.5 30.0 32.4 38.1 Polybutylene adipate 59.7 55.6 68.7 64.4 67.9 63.4 58.2 52.5 1,4-Butanediol 6.3 6.3 6.3 6.3 6.6 6.6 9.4 9.4 Citrofol BII 10.1 10.1 - - - - - - KX324 - 1.0∙ ^10-3 - 0.5∙10 ^-3 - 0.5∙10 ^-3 - 0.5∙10 ^-3

3. Example 3 - Measurement

Mechanical properties are measured according to the following standards:

Table 5. Mechanical property measurement standards. Unit standard density g/cm ³ DIN EN ISO 1183-1:2019-09, A Shaw hardness - DIN ISO 48-4:2021-02 Tensile strength MPa DIN 53504:2017-03 Elongation at break % DIN 53504:2017-03 Tear strength kN/m DIN ISO 34-1:2016-09 Wear and tear mm ³ DIN ISO 4649:2021-06 Compression set % DIN ISO 815-1:2022-04 Fika temperature °C DIN EN ISO 306:2023-03, A

4. Example 4 - Mechanical Properties

Table 6. Mechanical properties of compositions A1-D2. Unit composition A1 A2 B1 B2 C1 C2 D1 D2 density g/cm ³ 1.081 1.090 1.106 1.113 1.122 1.134 1.131 1.145 Shaw hardness - 72 74 78 78 86 88 89 91 Tensile strength MPa 33 48 31 50 40 46 53 57 Elongation at break % 800 440 550 410 500 360 490 370 Tear strength kN/m 41 twenty three 47 29 69 55 88 67 Wear and tear mm ³ 43 26 41 30 34 30 38 39 Compression set 72 h/23 °C/30 min % 28 11 twenty four 10 twenty two 16 twenty three twenty one 24 h/70 °C/30 min % 45 18 41 18 37 17 40 twenty one 24 h/100 °C/30 min % 79 54 67 50 70 53 69 68 Fika temperature 10 N/120 °C/h °C 63.7 130.2 100.6 135.7 109.9 141.3 118.2 127.6 10 N/50 °C/h °C 63.9 127.6 95.3 133.6 107.8 137.0 115.7 140.7

Table 7. Mechanical properties of compositions E1-H2. Unit TPU composition E1 E2 F1 F2 G1 G2 H1 H2 density g/cm ³ 1.210 1.209 1.214 1.218 1.217 1.221 1.226 1.231 Shaw hardness - 71 75 79 82 90 87 92 94 Tensile strength MPa 36 43 38 63 44 62 39 49 Elongation at break % 840 510 790 560 720 610 610 430 Tear strength kN/m 51 46 61 38 74 77 87 106 Wear and tear mm ³ 63 42 30 38 57 33 63 42 Compression set 72 h/23 °C/30 min % 26 11 25 14 twenty two 13 twenty one 15 24 h/70 °C/30 min % 34 15 37 twenty one 36 twenty two 41 twenty three 24 h/100 °C/30 min % 63 46 61 54 52 46 61 61 Fika temperature 10 N/120 °C/h °C 75.9 131 99.2 129.6 128.1 139.8 117.8 140.2 10 N/50 °C/h °C 73.8 128.9 97 129.2 126.9 138.4 119.6 140.6

Table 8. Mechanical properties of TPU compositions I1-L2. Unit TPU composition I1 I2 J1 J2 K1 K2 L1 L2 density g/cm ³ 1.162 1.168 1.179 1.187 1.184 1.192 1.201 1.212 Shaw hardness - 67 73 80 78 83 86 93 94 Tensile strength MPa 31 46 55 52 57 47 56 50 Elongation at break % 900 620 620 460 620 440 510 340 Tear strength kN/m 52 42 65 50 70 74 105 126 Wear and tear mm ³ 47 30 32 36 38 43 41 50 Compression set 72 h/23 °C/30 min % twenty four 15 19 9 18 10 17 twenty one 24 h/70 °C/30 min % 43 18 28 13 30 13 38 25 24 h/100 °C/30 min % 70 56 52 36 52 40 44 55 Fika temperature 10 N/120 °C/h °C 68.9 111.4 106.0 145.0 118.5 150.9 134.2 152.1 10 N/50 °C/h °C 64.4 107.3 103.8 142.0 116.3 146.8 134.4 150.9

Table 9. Mechanical properties of TPU compositions M1-P2. Unit TPU composition M1 M2 N1 N2 O1 O2 P1 P2 density g/cm ³ 1.181 1.183 1.194 1.196 1.194 1.195 1.195 1.213 Shaw hardness - 80 86 80 82 80 82 91 94 Tensile strength MPa 57 52 70 62 55 69 50 72 Elongation at break % 620 640 570 470 510 470 590 450 Tear strength kN/m 81 72 86 71 73 71 94 116 Wear and tear mm ³ 38 37 39 40 35 37 46 41 Compression set 72 h/23 °C/30 min % 31 twenty one 19 14 18 11 twenty four 17 24 h/70 °C/30 min % 34 twenty one 30 19 28 17 36 20 24 h/100 °C/30 min % 54 41 50 48 47 45 65 48 Fika temperature 10 N/120 °C/h °C 109.8 152.3 114.7 134.5 120.3 136.0 123.9 146.2 10 N/50 °C/h °C 110.0 150.9 111.6 130.2 119.3 133.2 124.6 143.4

5. Example 5 - Conclusion

Comparing the standard composition with its respective improved counterparts clearly shows an increase in compression set, wear loss, and Fika temperature, while other properties such as tensile strength, density, and hardness remain virtually unchanged. Only a slight decrease in elongation at break is observed. Despite these significant improvements, these materials can still be processed thermoplastically using standard processing techniques, such as injection molding and extrusion.

cited literature WO 2018/146336 WO 2015/144765 Plastics Additives Handbook, 5th Edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001 ([1]), p.98-S136 WO 94/20568 WO 2007/082838 A1 WO2017030835 WO 2013/153190 A1 WO201001001

without

without

Claims (14)

A composition comprising a thermoplastic polyurethane, wherein the thermoplastic polyurethane is prepared from the following building blocks: a diisocyanate, a polyol, a chain expander, and wherein the composition contains an alkaline metal salt in an amount ranging from 0.1 ppm to 100 ppm relative to the total amount of the composition. The composition of claim 1, wherein the alkaline metal salt loading is between 0.1 ppm and 50 ppm relative to the total amount of the composition, more preferably between 0.1 ppm and 20 ppm, and even more preferably between 0.5 ppm and 10 ppm. The composition of claim 1 or 2, wherein the alkaline metal salt comprises an alkaline metal carboxylate. The composition of any one of claims 1 to 3, wherein the alkali metal salt comprises potassium acetate or potassium formate. The composition of any one of claims 1 to 4, wherein the alkali metal salt comprises potassium acetate. The composition of any one of claims 1 to 5, further comprising a catalyst. The composition of claim 6, wherein the catalyst is selected from the group consisting of a tertiary amine and an organometallic compound, or a mixture thereof. The composition of claim 6, wherein the organometallic compound is selected from the group consisting of titanium esters, iron compounds, tin compounds and bismuth salts, or a mixture thereof. The composition of any one of claims 1 to 8, wherein the compression set of the composition is less than 28%, preferably less than 25%, and more preferably less than 23%, as measured according to DIN ISO 815-1:2022-04, 70°C, 24 hours, and a relaxation time of 30 minutes. The composition of any one of claims 1 to 9, wherein the polyisocyanate is an aromatic polyisocyanate, preferably methylene diphenyl diisocyanate (MDI). The composition of any one of claims 1 to 10, wherein the chain extender has 2 or 3 isocyanate-reactive groups, or a mixture thereof, more preferably, the chain extender has a functionality of 2.0 to 2.1, more preferably 2.00 to 2.05, and even more preferably 2.00 to 2.03. A method for making a composition as claimed in any one of claims 1 to 11, wherein the building blocks diisocyanate, polyol, chain extender and alkaline metal salt are mixed to make the thermoplastic polyurethane and then the components of the composition are added as needed. Use of the composition of any one of claims 1 to 11 or the composition obtained by the method of claim 12 for manufacturing an article. An article manufactured using the composition of any one of claims 1 to 11 or the composition obtained by the method of claim 12.