HARD-PHASE MODIFIED THERMOPLASTIC POLYURETHANE

Description

[0001] The present invention relates to a thermoplastic polyurethane obtainable or obtained by a process comprising reacting a thermoplastic polyester (PE-1) with a diamine (D1) to obtain a composition (Z1) comprising an amide (PA-1), and reacting the resulting composition (Z1) with an isocyanate composition (I1) comprising at least one polyisocyanate and a polyol composition (P1), wherein the diamine (D1) has a molecular weight in the range from 50 g / mol to 700 g / mol. The present invention further relates to a process for producing such a thermoplastic polyurethane and to molded articles comprising a thermoplastic polyurethane according to the invention.

[0002] Thermoplastic polyurethanes are widely known for their good mechanical properties, high abrasion resistance, and high elasticity. They are therefore widely used in a wide variety of applications.

[0003] US 2018 / 291141 A1 discloses a process for producing thermoplastic polyurethanes and the corresponding thermoplastic polyurethane in which a diamine is used as a chain extender.

[0004] Thermoplastic polyurethanes are also used in a variety of ways in the automotive sector. High thermal stability is required for certain applications, such as charging cables for hybrid and electric vehicles. The relevant standards for cables in automotive applications are LV 112 and ISO 6722, which classify the materials according to specific temperature classes.

[0005] For new applications, manufacturers often choose cables suitable for applications close to the engine with temperature class D up to 150°C. Examples include the engine cable harness or the transmission connection. Electric and hybrid vehicles place particularly high demands on the cable harness and cables, which are only partially comparable with conventional on-board electrical systems. Due to high voltages of up to 1000 V and correspondingly high currents, these cables must withstand significantly higher temperatures than their predecessors. The cables must withstand the standard winding test after 3000 hours of hot air aging at 150°C.

[0006] For temperature class D (up to 150 °C), ethylene tetrafluoroethylene copolymers (ETFE) are used, among others. In the event of a fire, corrosive gases are released when ETFE is used, which often limits the use of these materials.

[0007] Another material is special cross-linked polyolefin compounds. However, these cross-linked polyolefin compounds are very complex and expensive to produce due to the necessary subsequent cross-linking through irradiation or vulcanization, and they often reach their limits due to their chemical resistance and low mechanical strength. These cross-linked materials also have the disadvantage of not being recyclable and causing watertightness issues when molding connectors and grommets.

[0008] The now widely used LV 112 standard also introduces stricter requirements regarding hydrolysis resistance at high temperatures. While ISO 6722 requires service lives of 1,000 to 3,000 hours at 85 degrees Celsius and 85 percent relative humidity, LV 112 requires a service life of 3,000 hours.

[0009] The remaining requirements for cable sheathing are largely identical in both regulations and are now standard for the materials offered for this purpose. These include resistance to cold, media resistance, and inhibition of fungal growth, as well as compatibility with other materials in the cable harness, such as adhesive tapes, heat-shrink tubing, and connectors.

[0010] However, for many applications, there are no materials available that combine good mechanical properties with the specific requirements of automotive applications. Even many conventional thermoplastic polyurethanes degrade under these stresses.

[0011] One object underlying the present invention was therefore to provide thermoplastic polyurethanes which have good mechanical properties and high temperature stability.

[0012] According to the invention, this object is achieved by a thermoplastic polyurethane obtainable or obtained by a process comprising the reaction of an isocyanate composition (II) containing at least one polyisocyanate and a polyol composition (P1),

[0013] wherein at least one diamine (D1) having a molecular weight in the range from 50 g / mol to 700 g / mol is used and wherein the diamine D1 is reacted with a thermoplastic polyester (PE-1) to form an amide (PA-1) before the reaction with the isocyanate composition (I1) and the polyol composition (P1).

[0014] According to the invention, this object is thus also achieved by a thermoplastic polyurethane, obtainable or obtained by a process comprising the reaction of an isocyanate composition (II) containing at least one polyisocyanate and a polyol composition (P1), wherein at least one diamine (D1) having a molecular weight in the range from 50 g / mol to 700 g / mol is reacted with a thermoplastic polyester (PE-1) to form an amide (PA-1) before the reaction with the isocyanate composition (II) and the polyol composition (P1).

[0015] Accordingly, the present invention also relates to a thermoplastic polyurethane obtainable or obtained by a process comprising steps (i) and (ii) (i) reacting a thermoplastic polyester (PE-1) with a diamine (D1) to obtain a composition (Z1) containing an amide (PA-1), (ii) reacting the composition (Z1) obtained according to step (i) with an isocyanate composition (I1) containing at least one polyisocyanate and a polyol composition (P1), wherein the diamine (D1) has a molecular weight in the range of 50 g / mol to 700 g / mol.

[0016] According to an alternative embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the diamine (D1) is used as a chain extender.

[0017] Thus, according to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the process comprises the reaction of components (a) to (c): (a) the isocyanate composition (II) containing at least one polyisocyanate, (b) the polyol composition (P1), and (c) the diamine (D1) as chain extender.

[0018] If the diamine (D1) is used as a chain extender, the process can be carried out under standard conditions. Diamines (D1) selected from compounds of the general formula (I) or (II) are particularly suitable as chain extenders: wherein R1 and R2 are independently selected from the group consisting of O-CH 3 , CH 2 CH 3 , S-CH 3 , NH-CH 3 , N(CH 3 ) 2 and H , , or where a) X 1 = = Y 2 = H, b) X 1 = X 2 = Y 1 = Y 2 = CH 3 c) X 1 = X 2 = Y 1 = Y 2 = isopropyl d) X 1 = X 2 = Y 1 = Y 2 = C 2 H 5 , e) X 1 = X 2 = Y 1 = Y 2 = butyl f) X 1 = X 2 = Y 1 = Y 2 = tert. Butyl, g) X 1 = X 2 = H and Y 1 = Y 2 = CH 3 , h) X 1 = X 2 = H and Y 1 = Y 2 = isopropyl i) X 1 = X 2 = H and Y 1 = Y 2 = C 2 H 5 j) X 1 = X 2 = H and Y 1 = Y 2 = butyl or k) X 1 = X 2 = H and Y 1 = Y 2 = tert. Butyl and Z is selected from the group consisting of CH 2 , CHCH 3 , C(CH 3 ) 2 , O and S. Accordingly, the present invention also relates to a thermoplastic polyurethane obtainable or obtained by a process comprising the reaction of an isocyanate composition (II) containing at least one polyisocyanate and a polyol composition (P1), wherein at least one diamine (D1) having a molecular weight in the range from 50 g / mol to 700 g / mol is used, selected from compounds of the general formula (I) or (II): wherein R1 and R2 are independently selected from the group consisting of O-CH 3 , CH 2 CH 3 , S-CH 3 , NH-CH 3 , N(CH 3 ) 2 and H , , or where a) X 1 = X 2 = Y 1 = Y 2 = H, b) X 1 = X 2 = Y 1 = Y 2 = CH 3 c) X 1 = X 2 = Y 1 = Y 2 = isopropyl d) X 1 = X 2 = Y 1 = Y 2 = C 2 H 5 , e) X 1 = X 2 = Y 1 = Y 2 = butyl f) X 1 = X 2 = Y 1 = Y 2 = tert. Butyl, g) X 1 = X 2 = H and Y 1 = Y 2 = CH 3 , h) X 1 = X 2 = H and Y 1 = Y 2 = isopropyl i) X 1 = X 2 = H and Y 1 = Y 2 = C 2 H 5 j) X 1 = X 2 = H and Y 1 = Y 2 = butyl or k) X 1 = X 2 = H and Y 1 = Y 2 = tert. butyl and Z is selected from the group consisting of CH 2 , CHCH 3 , C(CH 3 ) 2 , O and S.

[0019] According to one embodiment, the process according to the invention comprises, in particular, steps (i) and (ii). According to step (i), a thermoplastic polyester (PE-1) is reacted with a diamine (D1) to obtain a composition (Z1) comprising an amide (PA-1), wherein the diamine (D1) has a molecular weight in the range from 50 g / mol to 700 g / mol. According to step (ii) of the process according to the invention, the composition (Z1) obtained according to step (i) is reacted with an isocyanate composition (II) comprising at least one polyisocyanate and a polyol composition (P1).

[0020] The process according to the invention produces thermoplastic polyurethanes with a modified hard phase. Surprisingly, it has been shown that the targeted, stepwise reaction of the components results in thermoplastic polyurethanes with good mechanical properties and high temperature resistance. This makes them particularly suitable for use as cable sheathing. For many applications in the field of cable sheathing, it is further advantageous that molded articles obtained from the thermoplastic polyurethanes according to the invention by extrusion or injection molding have a matte surface.

[0021] The reaction according to step (i) preferably takes place continuously. According to a further embodiment, the present invention accordingly relates to a process for producing a thermoplastic polyurethane as described above, wherein the reaction according to step (i) takes place continuously.

[0022] In step (i), the thermoplastic polyester (PE-1) is reacted with the diamine (D1). In the context of the present invention, an amide is formed. In principle, all common diamines having a molecular weight in the range from 50 g / mol to 700 g / mol, preferably in the range from 50 to 500 g / mol, can be used as the diamine (D1). Suitable diamines include, for example, aliphatic or aromatic diamines. Aromatic diamines are preferred according to the invention.

[0023] It has proven particularly advantageous to use diamines that have aromatic structures. In the context of the present invention, preference is given to using diamines (D1) selected from compounds of the general formula (I) or (II): wherein R1 and R2 are independently selected from the group consisting of O-CH 3 , CH 2 CH 3 , S-CH 3 , NH-CH 3 , N(CH 3 ) 2 and H , , or where a) X 1 = = Y 2 = H, b) X 1 = X 2 = Y 1 = Y 2 = CH 3 c) X 1 = X 2 = Y 1 = Y 2 = isopropyl d) X 1 = X 2 = Y 1 = Y 2 = C 2 H 5 , e) X 1 = X 2 = Y 1 = Y 2 = butyl f) X 1 = X 2 = Y 1 = Y 2 = tert. Butyl, g) X 1 = X 2 = H and Y 1 = Y 2 = CH 3 , h) X 1 = X 2 = H and Y 1 = Y 2 = isopropyl i) X 1 = X 2 = H and Y 1 = Y 2 = C 2 H 5 j) X 1 = X 2 = H and Y 1 = Y 2 = butyl or k) X 1 = X 2 = H and Y 1 = Y 2 = tert. butyl and Z is selected from the group consisting of CH 2 , CHCH 3 , C(CH 3 ) 2 , O and S.

[0024] According to a further embodiment, the present invention accordingly relates to a thermoplastic polyurethane as described above, wherein the diamine (D1) is selected from compounds of the general formula (I) or (II): wherein R1 and R2 are independently selected from the group consisting of O-CH 3 , CH 2 CH 3 , S-CH 3 , NH-CH 3 , N(CH 3 ) 2 and H , , or where a) X 1 = X 2 = Y 1 = Y 2 = H, b) X 1 = X 2 = Y 1 = Y 2 = CH 3 c) 2 = Y 1 = Y 2 = tert. Butyl, g) X 1 = X 2 = H and Y 1 = Y 2 = CH 3 , h) X 1 = X 2 = H and Y 1 = Y 2 = isopropyl i) X 1 = X 2 = H and Y 1 = Y 2 = C 2 H 5 j) X 1 = X 2 = H and Y 1 = Y 2 = butyl or k) X 1 = X 2 = H and Y 1 = Y 2 = tert. butyl and Z is selected from the group consisting of CH 2 , CHCH 3 , C(CH 3 ) 2 , O and S.

[0025] Particularly preferred in the context of the present invention is a diamine (D1) which has the general formula (III): where R1 = R2 = S-CH 3 or R1 = R2 = CH 2 CH 3.

[0026] According to a further embodiment, the present invention accordingly relates to a thermoplastic polyurethane as described above, wherein the diamine (D1) has the general formula (III): where R1 = R2 = S-CH 3 or R1 = R2 = CH 2 CH 3.

[0027] Mixtures of the diamines mentioned can also be used in the context of the present invention.

[0028] In step (i), a thermoplastic polyester (PE-1) is used. Thermoplastic polyesters suitable for the invention are known per se. Suitable polyesters are composed of at least one dicarboxylic acid and at least one suitable dihydroxy compound. The polyesters can be produced, for example, by polycondensation of aliphatic or aromatic dicarboxylic acids or mixtures of aromatic and aliphatic and / or cycloaliphatic dicarboxylic acids and the corresponding ester-forming derivatives, such as dicarboxylic anhydrides, mono- and / or diesters with expediently a maximum of 4 carbon atoms in the alcohol radical, with aliphatic dihydroxy compounds at elevated temperatures, for example from 160 to 260°C, in the presence or absence of esterification catalysts.

[0029] Suitable dicarboxylic acids according to the invention are aromatic dicarboxylic acids, for example naphthalenedicarboxylic acids, isophthalic acid, and especially terephthalic acid, or mixtures of these dicarboxylic acids. Also suitable within the scope of the present invention are aliphatic and / or cycloaliphatic dicarboxylic acids, for example having 4 to 14 carbon atoms, such as succinic, adipic, azelaic, sebacic, dodecanedioic acid, and / or cyclohexanedicarboxylic acid.

[0030] According to the invention, polyesters of functionalized dicarboxylic acids can also be used, for example polyesters based on lactic acid.

[0031] Aliphatic or aromatic dihydroxy compounds can be used as further structural components of the thermoplastic polyesters (PE-1) in the context of the present invention. Preferred aliphatic dihydroxy compounds are alkanediols having 2 to 6 carbon atoms and cycloalkanediols having 5 to 7 carbon atoms. Examples of these compounds that are preferably used are 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, and 1,4-cyclohexanediol, or mixtures of at least two of the diols mentioned.

[0032] Thermoplastic polyesters selected from the group consisting of polyalkylene terephthalates and poly-L-lactic acid are particularly suitable as thermoplastic polyesters.

[0033] According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the thermoplastic polyester (PE-1) is selected from the group consisting of polyalkylene terephthalates and poly-L-lactic acid.

[0034] According to the invention, suitable molecular weight ranges (Mn) of the polyester used are in the range from 2000 to 100,000, particularly preferably in the range from 10,000 to 50,000.

[0035] According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the thermoplastic polyester (PE-1) has a molecular weight in the range from 1000 g / mol to 60000 g / mol, for example also in the range from 1500 g / mol to 5000 g / mol.

[0036] Unless otherwise stated, the weight-average molecular weights (Mw) of thermoplastic polyesters dissolved in HFIP (hexafluoroisopropanol) are determined using GPC in the context of the present invention. The molecular weight is determined using two GPC columns connected in series (PSS gel; 100A; 5µ; 300*8mm, Jordi-Gel DVB; MixedBed; 5µ; 250*10mm; column temperature 60°C; flow 1 mL / min; RI detector). Calibration is performed with polymethyl methacrylate (EasyCal; PSS, Mainz), and HFIP is used as the mobile phase.

[0037] For example, the proportion of diamine relative to the polyester used can be in the range of 5 to 20%.

[0038] According to step (i), a composition (Z1) is obtained which contains an amide (PA-1). Within the scope of the present invention, the composition (Z1) may contain further components, for example, unreacted thermoplastic polyester or unreacted diamine. The composition (Z1) is typically a mixture which, in addition to the amide (PA-1), may also contain unreacted polyester (PE-1) or unreacted diamine. According to the invention, the amide (PA-1) is present as a mixture, wherein the individual molecules may differ, for example, in the distribution and length of the polyester blocks.

[0039] Preferably, the reaction conditions in the reaction according to step (i) are selected such that the amide (PA-1) has a free amine functionality and a free OH functionality.

[0040] The composition preferably contains the amide (PA-1) as well as other components such as catalysts or additives, for example, waxes, stabilizers, and fillers. Additives are typically present in the composition in amounts of up to 5%.

[0041] The reaction according to step (ii) is carried out under suitable conditions that allow the diisocyanate to react with the free reactive groups of the amide (PA-1). According to the invention, the reaction can be carried out in a suitable apparatus, with suitable processes being known per se to those skilled in the art. According to the invention, it is also possible to use additives or auxiliaries to accelerate or improve the reaction according to step (i) or (ii). In particular, catalysts can be used.

[0042] Suitable catalysts for the reaction according to step (i) are known per se to the person skilled in the art. For example, a catalyst can be used in an amount ranging from 10 to 200 ppm.

[0043] In particular, the reaction according to step (i) or the reaction according to step (ii) or the reaction according to steps (i) and step (ii) can be carried out in an extruder.

[0044] The reaction according to step (i) can be carried out, for example, at a temperature in the range from 200 to 310°C, preferably in the range from 220 to 300°C and in particular from 220 to 280°C, more preferably from 230 to 270°C and a residence time of from 10 seconds to 30 minutes, preferably from 15 seconds to 10 minutes in, for example, a flowable, softened or preferably molten state of the polyester and the diamine, in particular by stirring, rolling, kneading or preferably extruding, for example using conventional plasticizing devices, such as mills, kneaders or extruders, preferably in an extruder.

[0045] The method according to the invention may comprise further steps, for example temperature adjustments or shaping steps.

[0046] The composition (Z1) is then reacted according to step (ii) with an isocyanate composition (I1) and a polyol composition (P1).

[0047] According to the invention, the polyol composition (P1) contains at least one polyol, in particular at least one polycarbonate polyol (PC1).

[0048] Suitable polycarbonate polyols are known per se to the person skilled in the art. Particularly suitable for the purposes of the present invention are aliphatic polycarbonatediols. Suitable polycarbonatediols are, for example, polycarbonatediols based on alkanediols. Suitable polycarbonatediols are strictly difunctional OH-functional polycarbonatediols, preferably strictly difunctional OH-functional aliphatic polycarbonatediols. Suitable polycarbonatediols are based, for example, on butanediol, pentanediol, or hexanediol, in particular 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentane-(1,5)-diol, or mixtures thereof, particularly preferably 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, or mixtures thereof.In the context of the present invention, preference is given to using polycarbonatediols based on butanediol and hexanediol, polycarbonatediols based on pentanediol and hexanediol, polycarbonatediols based on hexanediol, and mixtures of two or more of these polycarbonatediols.

[0049] According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the at least one polycarbonate polyol (PC1) is selected from the group consisting of polycarbonate diols based on butanediol and hexanediol, polycarbonate diols based on pentanediol and hexanediol, polycarbonate diols based on hexanediol, and mixtures of two or more of these polycarbonate diols.

[0050] The polycarbonate diols used preferably have a number-average molecular weight Mn in the range from 500 to 4000, determined by GPC, preferably in the range from 650 to 3500, determined by GPC, particularly preferably in the range from 800 to 3000, determined by GPC.

[0051] According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the at least one polycarbonate polyol (PC1) has a number-average molecular weight Mn in the range from 500 to 4000, determined by GPC.

[0052] According to the invention, the polyol composition (P1) may contain further polyols. Suitable polyols are generally known to the person skilled in the art and are described, for example, in "Kunststoffhandbuch, Volume 7, Polyurethane," Carl Hanser Verlag, 3rd edition 1993, Chapter 3.1. Polyesterols or polyetherols are particularly preferably used as polyols. Polyether polyols are particularly preferred. The number-average molecular weight of the polyols used according to the invention is preferably between 500 g / mol and 3000 g / mol, more preferably between 600 g / mol and 2500 g / mol, in particular between 650 g / mol and 2000 g / mol.

[0053] According to the invention, preferred polyetherols are polyethylene glycols, polypropylene glycols and polytetrahydrofurans.

[0054] According to the invention, the polyol composition may also contain a solvent, for example. Suitable solvents are known to those skilled in the art.

[0055] In the context of the present invention, additives or auxiliaries can also be used in the reaction in the polyol composition, for example antioxidants, UV absorbers, UV filters, hydrolysis inhibitors, waxes, lubricants, plasticizers, processing aids, nucleating agents, fillers, flame retardants.

[0056] According to the invention, at least one isocyanate composition (I1) comprising at least one polyisocyanate is used. A diisocyanate is preferably used as the polyisocyanate. Mixtures of two or more diisocyanates can also be used according to the invention. Preferred diisocyanates in the context of the present invention are, in particular, aliphatic or aromatic diisocyanates.

[0057] The isocyanates used are preferably aliphatic, cycloaliphatic, araliphatic and / or aromatic isocyanates, more preferably tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 2-ethylbutylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, butylene-1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4- and / or 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and / or -2,6-cyclohexane diisocyanate and / or 4,4'-, 2,4'- and 2,2'-Dicyclohexylmethane diisocyanate, 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-tolylene diisocyanate (TDI), diphenylmethane diisocyanate, 3,3'-dimethyldiphenyl diisocyanate, 1,2-diphenylethane diisocyanate, and / or phenylene diisocyanate. 4,4'-MDI is particularly preferred.

[0058] As aliphatic diisocyanates, conventional aliphatic and / or cycloaliphatic diisocyanates are used, for example tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 2-ethyltetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate (HDI), pentamethylene-1,5-diisocyanate, butylene-1,4-diisocyanate, trimethylhexamethylene-1,6-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate, IPDI), 1,4- and / or 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and / or 1-Methyl-2,6-cyclohexane diisocyanate, 4,4'-, 2,4'- and / or 2,2'-methylenedicyclohexyl diisocyanate (H12MDI).

[0059] According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the polyisocyanate is selected from the group consisting of methylenediphenyl diisocyanate and aliphatic diisocyanates.

[0060] According to the invention, the isocyanate composition can be used in pure form or in the form of a composition containing the diisocyanate and at least one solvent. Suitable solvents are known to those skilled in the art. Suitable solvents include, for example, non-reactive solvents such as ethyl acetate, methyl ethyl ketone, tetrahydrofuran, and hydrocarbons.

[0061] According to the invention, further starting materials can be added in the reaction according to step (ii), for example catalysts or auxiliaries and additives.

[0062] Catalysts which particularly accelerate the reaction between the NCO groups and the hydroxyl groups of the compounds which are reactive towards isocyanates are, for example, tertiary amines, in particular triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo-(2,2,2)-octane, in another preferred embodiment these are organic metal compounds such as titanic acid esters, iron compounds, preferably iron(III) acetylacetonate, tin compounds, preferably tin diacetate, tin dioctoate, tin dilaurate or the tin dialkyl salts of aliphatic carboxylic acids, preferably dibutyltin diacetate, dibutyltin dilaurate or bismuth salts in which bismuth is preferably present in the oxidation states 2 or 3, in particular 3. Salts of carboxylic acids are preferred. Carboxylic acids having 6 to 14 carbon atoms, particularly preferably 8 to 12 carbon atoms, are preferably used as carboxylic acids.Examples of suitable bismuth salts are bismuth(III) neodecanoate, bismuth 2-ethylhexanoate and bismuth octanoate.

[0063] The catalysts are preferably used in amounts of 0.0001 to 0.1 part by weight per 100 parts by weight of the isocyanate-reactive compound (b). Tin catalysts, especially tin dioctoate, are preferred.

[0064] The catalysts are typically used in amounts of 3 ppm to 2000 ppm, preferably 10 ppm to 1200 ppm, more preferably 20 ppm to 1000 ppm, and most preferably 30 ppm to 800 ppm.

[0065] In addition to catalysts, conventional auxiliaries can also be added during the reaction according to step (ii). Examples include surfactants, fillers, other flame retardants, nucleating agents, oxidation stabilizers, lubricants and demolding aids, dyes and pigments, optionally stabilizers (e.g., to protect against hydrolysis, light, heat, or discoloration), inorganic and / or organic fillers, reinforcing agents, and plasticizers. Suitable auxiliaries and additives can be found, for example, in the Kunststoffhandbuch (Plastics Handbook), Volume VII, published by Vieweg and Höchtlen, Carl Hanser Verlag, Munich 1966 (pp. 103-113).

[0066] According to the invention, a thermoplastic polyurethane is obtained. The properties of the thermoplastic polyurethane according to the invention can vary widely. The thermoplastic polyurethane according to the invention preferably has a Shore hardness in the range from 45A to 78D, preferably a Shore hardness in the range from 80A to 70D, particularly preferably a Shore hardness in the range from 70A to 64D, further preferably in the range from 70A to 98A.

[0067] According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the thermoplastic polyurethane has a Shore hardness in the range from Shore 45 A to Shore 78 D.

[0068] According to a further aspect, the present invention also relates to a process for producing a thermoplastic polyurethane comprising the reaction of an isocyanate composition (II) containing at least one polyisocyanate and a polyol composition (P1), wherein at least one diamine (D1) having a molecular weight in the range from 50 g / mol to 700 g / mol is used and wherein the at least one diamine (D1) having a molecular weight in the range from 50 g / mol to 700 g / mol is reacted with a thermoplastic polyester (PE-1) to form an amide (PA-1) before the reaction with the isocyanate composition (II) and the polyol composition (P1).

[0069] In particular, the present invention also relates to a process for producing a thermoplastic polyurethane, comprising steps (i) and (ii) (i) reacting a thermoplastic polyester (PE-1) with a diamine (D1) to obtain a composition (Z1) containing an amide (PA-1) (ii) reacting the composition (Z1) obtained according to step (i) with an isocyanate composition (II) containing at least one polyisocyanate and a polyol composition (P1), wherein the diamine (D1) has a molecular weight in the range of 50 g / mol to 700 g / mol.

[0070] Accordingly, the present invention relates to a process for producing a thermoplastic polyurethane comprising the reaction of an isocyanate composition (II) containing at least one polyisocyanate and a polyol composition (P1), comprising steps (i) and (ii): (i) reacting a thermoplastic polyester (PE-1) with a diamine (D1) to obtain a composition (Z1) containing an amide (PA-1) (ii) reacting the composition (Z1) obtained according to step (i) with an isocyanate composition (I1) containing at least one polyisocyanate and a polyol composition (P1), wherein the diamine (D1) has a molecular weight in the range of 50 g / mol to 700 g / mol.

[0071] According to an alternative embodiment, the present invention relates to a process for producing a thermoplastic polyurethane, comprising the reaction of components (a) to (c): (a) the isocyanate composition (II) containing at least one polyisocyanate, (b) the polyol composition (P1), and (c) the diamine (D1) as chain extender.

[0072] With regard to preferred embodiments, reference is made to the above-mentioned embodiments.

[0073] The present invention further relates to a composition comprising a thermoplastic polyurethane according to the invention. Within the scope of the present invention, the composition may contain further components such as fillers, glass fibers, plasticizers, or flame retardants. The composition may contain one or more of the congealed components.

[0074] The present invention also relates to the use of a thermoplastic polyurethane according to the invention as described above for the production of coatings, damping elements, bellows, films or fibers, molded articles, flooring for buildings and transport, random nonwovens, preferably seals, rolls, shoe soles, hoses, cables, cable connectors, cable sheathing, cushions, laminates, profiles, belts, saddles, foams, plug-in connections, trailing cables, solar modules, and automotive cladding. The use is preferably for the production of cable sheathing. Production takes place, preferably from granules, by injection molding, calendering, powder sintering, or extrusion and / or by additional foaming of the composition according to the invention.

[0075] According to a further aspect, the present invention also relates to a molded article comprising a thermoplastic polyurethane as described above or a thermoplastic polyurethane obtainable or obtained by a process as described above. The molded article according to the invention can be, for example, films, molded parts, rolls, fibers, automotive trim, hoses, cable connectors, bellows, trailing cables, cable sheathing, seals, belts, or damping elements.

[0076] Due to their good mechanical properties and good temperature behavior, the thermoplastic polyurethanes of the invention and the compositions of the invention are particularly suitable for the production of films, molded parts, rolls, fibers, automotive trim, hoses, cable connectors, bellows, trailing cables, cable sheathing, seals, belts, or damping elements. Accordingly, the present invention also relates to films, molded parts, rolls, fibers, automotive trim, hoses, cable connectors, bellows, trailing cables, cable sheathing, seals, belts, or damping elements comprising a thermoplastic polyurethane as described above or a composition as described above.

[0077] According to a further embodiment, a shaped body as described above, wherein the shaped body is selected from films, molded parts, rolls, fibers, automotive cladding, hoses, cable connectors, bellows, trailing cables, cable sheathing, seals, belts or damping elements.

[0078] The following examples serve to illustrate the invention. EXAMPLES 1. Input materials

[0079] PC polyol: Polycarbonate polyol E1195A: Standard TPU (benchmark), Elastollan 1195 A, thermoplastic polyurethane based on polyether, available from BASF Polyurethanes 785A HPM: Standard HPM TPU (Benchmark), Elastollan 785 A HPM, thermoplastic polyurethane based on polyester, available from BASF Polyurethanes Ethacure 300 Dimethylthiotoluenediamine (E300) Ethacure 100 Diethyltoluenediamine (E100) 2. General manufacturing example:

[0080] 2.1 The synthesis is carried out by reactive extrusion in a self-cleaning twin-screw extruder, based on the process described in EP1419188B1. In the twin-screw extruder, with a screw length to screw diameter ratio of 48, residence times of at least 40 s, preferably greater than 60 s, are achieved. The polymer melt obtained after transamidation and subsequent chain formation is processed into granules by underwater or strand granulation.

[0081] 2.2 Various samples were investigated for their mechanical properties. Compositions containing thermoplastic polyurethanes and dimethylthiotoluenediamine or diethyltoluenediamine were prepared using a one-shot process or a prepolymer process.

[0082] In the one-shot process, all components (diisocyanate (a), polyol (b), chain extender (c), and catalyst (e)) were introduced into a first zone of the extruder. The temperature was set between 150°C and 230°C at 200 rpm. After mixing the components and reacting for at least 40 seconds, preferably at least 60 seconds, granules were obtained from the polymer melt by strand pelletizing or underwater pelletizing.

[0083] For the semi-prepolymer process, diisocyanates (a), polyol (b), chain extender (c), and catalyst (e) were initially added in a first zone of the extruder. After thorough mixing and pre-reaction of these feedstocks, additional chain extender was added in the third or fifth zone. After this reaction for at least 40 seconds, preferably at least 60 seconds, granules were obtained from the polymer melt by strand pelletizing or underwater pelletizing. 2.3 Conditions for aging

[0084] SI specimens were stored in a forced-air oven at the appropriate temperature for the specified time. After the heat treatment, they were removed and cooled to room temperature. Mechanical tests were performed on the treated specimens.

[0085] The aging study shows that the inventive thermoplastic polyurethanes with different hard segment contents, produced using dimethylthiotoluenediamine or diethyltoluenediamine, remained dimensionally stable and retained their flexibility after storage at 180°C, 190°C, and 200°C for 6 hours. Furthermore, they still exhibited more than 50% of their original elongation at break after storage at 150°C for 3000 hours. Thus, the materials meet the requirements of a T4 standard for automotive applications. 3. Examples

[0086] 3.1 The following examples were produced in a Coperion ZSK58 MC twin-screw extruder with a process length of 48D (12 barrels). The melt was discharged from the extruder via a gear pump. After melt filtration, the polymer melts were processed into granules by underwater pelletizing, which were then continuously dried in a heated fluidized bed at 60-90°C to a water content of less than 0.03%.

[0087] The polybutylene terephthalate, Ultradur B4500 from BASF SE, was metered into the first zone. After the PBT melted, the reagent for transamidation, e.g., Etacure 100, and, if required, a catalyst, were added in the third zone. After transamidation, the other reaction components, such as diisocyanate and polyols, were added in the fifth zone. Additional additives were added in zone 8. Melt discharge and underwater pelletizing took place at melt temperatures of 220–230°C.

[0088] The barrel temperatures for the feed zone (zone 1) are 150°C. Melting and transamidation (zones 2-5) occur at temperatures of 250-300°C. Polymer buildup in zones 6-12 occurs at barrel temperatures of 240-210°C. The screw speed is between 180 and 240 rpm. The throughput is in the range of 180-220 kg / h. 3.2 Compositions

[0089] Example 1 E1195A with BDO Example 2 Polycarbonate polyol HPM TPU+E100, (97A) Example 3 785A HPM TPU with BDO Example 4 Polycarbonate polyol HPM TPU+E100, (92A) Example 5 Aliphatic HPM with E100, (86A) Example 6 Polycarbonate polyol aromatic TPU+E300 4. Results: 4.1 Overview of aging behavior for cable applications (Class D):

[0090] sample Aging at 150°C / 3000 h Aging at 150°C / 3000 h Aging at 150°C / 3000 h Aging at 150°C / 3000 h Elongation at break after aging >50% Tensile strength before aging A20 MPa Example 1 - - - - - + Example 2 + + + + + + Example 3 + + - - - + 4.2 Overview of aging behavior for cable applications (Class E, 240°C, 6 hours):

[0091] sample Elongation at break before aging (%) Elongation at break after aging (%) Example 2 430 80 Example 3 620 melted 5. Results after storage 5.1 Storage at 150°C, 3000 hours

[0092] Composition sample Tensile strength before aging (MPa) Tensile strength after aging Elongation at break before aging (%) Elongation at break after aging aromatic HPM with E100 Example 4 31 16 450 150 aromatic HPM with E100 Example 2 35 20 430 90 aliphatic HPM with E100 Example 5 16 5 360 110 785A HPM Benchmark k 45 11 620 100 5.2 Storage at 175°C, 85% RH, 10 days

[0093] composition sample Tensile strength before aging (MPa) Tensile strength after aging Elongation at break before aging (%) Elongation at break after aging E1195A with BDO Standard Reference 55 melted 600 melted PC polyol TPU+Ethacure 300+MDI Example 6 13 10 360 200 aromatic HPM E100 Example 4 31 14 450 230 aromatic HPM with E100 Example 2 35 16 430 150 aliphatic (HDI) HPM with E100 Example 5 16 3 360 80 785A HPM with BDO Benchmark 45 20 620 190 5.3 Storage at 200°C, 6 hours

[0094] composition sample Tensile strength before aging (MPa) Tensile strength after aging Elongation at break before aging (%) Elongation at break after aging E1195A with BDO Standard Ref 55 melted 650 melted Comparison 1 with E100 Reference 1 9 3 680 1020 Comparison 2 with E100 Reference 2 14 7 440 680 Comparison 3 with E100 Reference 3 15 6 360 310 PC polyol TPU+Ethacure 300+MDI Example 6 13 8 360 100 aromatic HPM E100 Example 4 31 10 450 300 aromatic HPM with E100 Example 2 35 13 430 290 aliphatic HPM with E100 Example 5 16 9 360 190 785A HPM with BDO Benchmark 45 melted 620 melted 5.4 Storage at 85°C, 85% RH, 3000 hours

[0095] composition sample Tensile strength before aging (MPa) Tensile strength after aging Elongation at break before aging (%) Elongation at break after aging Shore hardness aromatic HPM with E100 Example 4 31 6 450 80 92A aromatic HPM with E100 Example 2 35 8 430 80 97A aliphatic HPM with E100 Example 5 16 5 360 80 86A 785A HPM Benchmark 45 3 620 30 85A

[0096] 6. The following properties of the polyurethanes obtained were determined using the methods mentioned: Shore hardness: DIN ISO 7619-1 Tensile strength and elongation at break: DIN 53504 Tear resistance: DIN ISO 34-1, B (b) Abrasion measurement: DIN ISO 4649 Density: DIN EN ISO 1183-1, A compression set DIN ISO 815 Cited literature

[0097] Plastics Handbook, Volume VII, edited by Vieweg and Höchtlen, Carl Hanser Verlag, Munich 1966 (pp. 103-113) EP 1 419 188 B1

Claims

1. A thermoplastic polyurethane obtainable or obtained by a process comprising reaction of an isocyanate composition (I1) comprising at least one polyisocyanate and a polyol composition (P1), wherein at least one diamine (D1) having a molecular weight in the range from 50 g / mol to 700 g / mol is employed and wherein the diamine D1 is reacted with a thermoplastic polyester (PE-1) to afford an amide (PA-1) before reaction with the isocyanate composition (I1) and the polyol composition (P1).

2. The thermoplastic polyurethane according to claim 1, wherein the process comprises the steps (i) and (ii): (i) reaction of a thermoplastic polyester (PE-1) with a diamine (D1) to obtain a composition (Z1) comprising an amide (PA-1), (ii) reaction of the composition (Z1) obtained according to step (i) with an isocyanate composition (I1) comprising at least one polyisocyanate and a polyol composition (P1), wherein the diamine (D1) has a molecular weight in the range from 50 g / mol to 700 g / mol.

3. The thermoplastic polyurethane according to either of claims 1 or 2, wherein the diamine (D1) is selected from compounds of general formula (I) or (II): wherein R1 and R2 are independently of one another selected from the group consisting of O-CH3, CH2CH3, S-CH3, NH-CH3, N(CH3)2 and H, or wherein a) X1 = X2 = Y1 = Y2 = H, b) X1 = X2 = Y1 = Y2 = CH3 c) X1 = X2 = Y1 = Y2 = isopropyl d) X1 = X2 = Y1 = Y2 = C2H5, e) X1 = X2 = Y1 = Y2 = butyl f) X1 = X2 = Y1 = Y2 = tert- butyl, g) X1 = X2 = H and Y1 = Y2 = CH3, h) X1 = X2 = H and Y1 = Y2 = isopropyl i) X1 = X2 = H and Y1 = Y2 = C2H5 j) X1 = X2 = H and Y1 = Y2 = butyl or k) X1 = X2 = H and Y1 = Y2 = tert- butyl and Z is selected from the group consisting of CH2, CHCH3, C(CH3)2, O and S.

4. The thermoplastic polyurethane according to any of claims 1 to 3, wherein the diamine (D1) has the general formula (III): wherein R1 = R2 = S-CH3 or R1 = R2 = CH2CH3.

5. The thermoplastic polyurethane according to any of claims 1 to 4, wherein the polyol composition (P1) comprises at least one polycarbonate polyol (PC1).

6. The thermoplastic polyurethane according to any of claims 1 to 5, wherein the thermoplastic polyester (PE-1) has a molecular weight measured according to the description in the range from 1500 g / mol to 60 000 g / mol.

7. The thermoplastic polyurethane according to any of claims 1 to 6, wherein the thermoplastic polyester (PE-1) is selected from the group consisting of polyalkylene terephthalates and poly-L-lactic acid.

8. The thermoplastic polyurethane according to any of claims 1 to 7, wherein the polyester (PE-1) has a molecular weight measured according to the description in the range from 1000 g / mol to 5000 g / mol.

9. The thermoplastic polyurethane according to any of claims 1 to 8, wherein the polyisocyanate is selected from the group consisting of methylene diphenyl diisocyanate and aliphatic diisocyanates.

10. The thermoplastic polyurethane according to any of claims 1 to 9, wherein the thermoplastic polyurethane has a Shore hardness in the range from Shore 45 A to Shore 78 D.

11. A process for producing a thermoplastic polyurethane comprising reaction of an isocyanate composition (I1) comprising at least one polyisocyanate and a polyol composition (P1), wherein at least one diamine (D1) having a molecular weight in the range from 50 g / mol to 700 g / mol is employed and wherein the diamine D1 is reacted with a thermoplastic polyester (PE-1) to afford an amide (PA-1) before reaction with the isocyanate composition (I1) and the polyol composition (P1).

12. A process for producing a thermoplastic polyurethane comprising reaction of an isocyanate composition (I1) comprising at least one polyisocyanate and a polyol composition (P1) according to claim 11 comprising the steps (i) and (ii), (i) reaction of a thermoplastic polyester (PE-1) with a diamine (D1) to obtain a composition (Z1) comprising an amide (PA-1), (ii) reaction of the composition (Z1) obtained according to step (i) with an isocyanate composition (I1) comprising at least one polyisocyanate and a polyol composition (P1), wherein the diamine (D1) has a molecular weight in the range from 50 g / mol to 700 g / mol.

13. A shaped article comprising a thermoplastic polyurethane according to any of claims 1 to 10 or a thermoplastic polyurethane obtainable or obtained by a process according to claim 11 or 12.

14. The shaped article according to claim 13, wherein the shaped article is selected from films, mouldings, wheels / rollers, fibres, automotive trim, hoses, cable plugs, bellows, trailing cables, cable sheathings, seals, belts or damping elements.